• Effects of the non-Markovianity and non-Gaussianity of active environmental noises on engine performance

  Title	: Effects of the non-Markovianity and non-Gaussianity of active environmental noises on engine performance
  Journal	: PHYSICAL REVIEW E, 2022

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Effects of the non-Markovianity and non-Gaussianity of active environmental noises on engine performance
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2022
  ABSTRACT	An active environment is a reservoir containing active materials, such as bacteria and Janus particles. Given the self-propelled motion of these materials, powered by chemical energy, an active environment has unique, nonequilibrium environmental noise. Recently, studies on engines that harvest energy from active environments have attracted a great deal of attention because the theoretical and experimental findings indicate that these engines outperform conventional ones. Studies have explored the features of active environments essential for outperformance, such as the non-Gaussian or non-Markovian nature of the active noise. We systematically study the effects of the non-Gaussianity and non-Markovianity of active noise on engine performance. We show that non-Gaussianity is irrelevant to the performance of an engine driven by any linear force (including a harmonic trap) regardless of time dependency, whereas non-Markovianity is relevant. However, for a system driven by a general nonlinear force, both non-Gaussianity and non-Markovianity enhance engine performance. Also, the memory effect of an active reservoir should be considered when fabricating a cyclic engine.

  
  

  

• Self-repelling bipedal exploration process

  Title	: Self-repelling bipedal exploration process
  Journal	: PHYSICAL REVIEW E, 2021

  
  

  논문

  NUMBER	P21027
  AUTHOR	Park, Hyunggyu,Dashti-N, Hor,Park, Hyunggyu
  TITLE	Self-repelling bipedal exploration process
  ARCHIVE	arXiv:2107.05303
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2021
  ABSTRACT	A self-repelling two-leg (biped) spider walk is considered where the local stochastic movements are governed by two independent control parameters fid and fih, so that the former controls the distance (d) between the legs positions, and the latter controls the statistics of self-crossing of the traversed paths. The probability measure for local movements is supposed to be the one for the true self-avoiding walk multiplied by a factor exponentially decaying with d. After a transient behavior for short times, a variety of behaviors have been observed for large times depending on the value of fid and fih. Our statistical analysis reveals that the system undergoes a crossover between two (small and large fid) regimes identified in large times (t). In the small fid regime, the random walkers (identified by the position of the legs of the spider) remain on average in a fixed nonzero distance in the large time limit, whereas in the second regime (large fid), the absorbing force between the walkers dominates the other stochastic forces. In the latter regime, d decays in a power-law fashion with the logarithm of time. When the system is mapped to a growth process (represented by a height field which is identified by the number of visits for each point), the roughness and the average height show different behaviors in two regimes, i.e., they show a power law with respect to t in the first regime and log t in the second regime. The fractal dimension of the random walker traces and the winding angle are shown to consistently undergo a similar crossover.

  
  

  

• Universal form of thermodynamic uncertainty relation for Langevin dynamics

  Title	: Universal form of thermodynamic uncertainty relation for Langevin dynamics
  Journal	: PHYSICAL REVIEW E, 2021

  
  

  논문

  NUMBER	P21033
  AUTHOR	Park, Hyunggyu,Park, Jong-Min,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Universal form of thermodynamic uncertainty relation for Langevin dynamics
  ARCHIVE	arXiv:2106.01599
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2021
  ABSTRACT	The thermodynamic uncertainty relation (TUR) provides a stricter bound for entropy production (EP) than that of the thermodynamic second law. This stricter bound can be utilized to infer the EP and derive other tradeoff relations. Though the validity of the TUR has been verified in various stochastic systems, its application to general Langevin dynamics has not been successfully unified, especially for underdamped Langevin dynamics, where odd parity variables in time-reversal operation such as velocity get involved. Previous TURs for underdamped Langevin dynamics are neither experimentally accessible nor reduced to the original form of the overdamped Langevin dynamics in the zero-mass limit. Here, we find a TUR for underdamped Langevin dynamics with an arbitrary time-dependent protocol, which is operationally accessible when all mechanical forces are controllable. We show that the original TUR is a consequence of our underdamped TUR in the zero-mass limit. This indicates that the TUR formulation presented here can be regarded as the universal form of the TUR for general Langevin dynamics.

  
  

  

• Geometry-induced rectification for an active object

  Title	: Geometry-induced rectification for an active object
  Journal	: PHYSICAL REVIEW RESEARCH, 2021

  
  

  논문

  NUMBER	P21018
  AUTHOR	Park, Hyunggyu ,Park, Jong-Min,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Geometry-induced rectification for an active object
  ARCHIVE	cond-mat/2104.09849
  FILE
  JOURNAL	PHYSICAL REVIEW RESEARCH, 2021
  ABSTRACT	Study on a rectified current induced by active particles has received a great attention due to its possible application to a microscopic motor in biological environments. Insertion of an {em asymmetric} passive object amid many active particles has been regarded as an essential ingredient for generating such a rectified motion. Here, we report that the reverse situation is also possible, where the motion of an active object can be rectified by its geometric asymmetry amid many passive particles. This may describe an unidirectional motion of polar biological agents with asymmetric shape. We also find a weak but less diffusive rectified motion in a {em passive} mode without energy pump-in. This moving by dissipation mechanism could be used as a design principle for developing more reliable microscopic motors.

  
  

  

• Thermodynamic uncertainty relation in the overdamped limit with a magnetic Lorentz force

  Title	: Thermodynamic uncertainty relation in the overdamped limit with a magnetic Lorentz force
  Journal	: PHYSICAL REVIEW RESEARCH, 2021

  
  

  논문

  NUMBER	P21019
  AUTHOR	Park, Hyunggyu ,Park, Jong-Min,Park, Hyunggyu
  TITLE	Thermodynamic uncertainty relation in the overdamped limit with a magnetic Lorentz force
  ARCHIVE	cond-mat/2105.12421
  FILE
  JOURNAL	PHYSICAL REVIEW RESEARCH, 2021
  ABSTRACT	In nonequilibrium systems, the relative fluctuation of a current has a universal trade-off relation with the entropy production, called the thermodynamic uncertainty relation (TUR). For systems with broken time reversal symmetry, its violation has been reported in specific models or in the linear response regime. Here, we derive a modified version of the TUR analytically in the overdamped limit for general Langevin dynamics with a magnetic Lorentz force causing time reversal broken. Remarkably, this modified version is simply given by the conventional TUR scaled by the ratio of the reduced effective temperature of the overdamped motion to the reservoir temperature, permitting a violation of the conventional TUR. Without the Lorentz force, this ratio becomes unity and the conventional TUR is restored. We verify our results both analytically and numerically in a specific solvable system.

  
  

  

• Brownian heat engine with active reservoirs

  Title	: Brownian heat engine with active reservoirs
  Journal	: PHYSICAL REVIEW E, 2020

  
  

  논문

  NUMBER	P20018
  AUTHOR	Park, Hyunggyu,Park, Jong-Min,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Brownian heat engine with active reservoirs
  ARCHIVE	cond-mat/2003.13189
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2020
  ABSTRACT	Microorganisms such as bacteria are active matter which consume chemical energy and generate their unique run-and-tumble motion. A swarm of such microorganisms provide a nonequilibrium active environment whose noise characteristics are different from those of thermal equilibrium reservoirs. One important difference is a finite persistence time, which is considerably large compared to that of the equilibrium noise, that is, the active noise is colored. Here we study a mesoscopic energy-harvesting device (engine) with active reservoirs harnessing this noise nature. For an exactly solvable linear model, we show that the performance from the active environment can surpass that from the equilibrium environment. Furthermore, we propose a proper definition of the active-reservoir temperature and show that the engine efficiency can overcome the conventional Carnot bound, thus the power-efficiency trade-off constraint is released. We also show that the efficiency at the maximum power can surpass the Curzon-Ahlborn efficiency. This remarkable enhancement originates from the extra unconventional entropy production beyond the conventional Clausius entropy production, due to the non-Markovian nature of the active reservoirs. Interestingly, the supremacy of the active engine critically depends on the timescale symmetry of two active reservoirs.

  
  

  

• Thermodynamic cost of synchronizing a population of beating cilia

  Title	: Thermodynamic cost of synchronizing a population of beating cilia
  Journal	: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2020

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Hyeon, Changbong,Park, Hyunggyu
  TITLE	Thermodynamic cost of synchronizing a population of beating cilia
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2020
  ABSTRACT	Synchronization among arrays of beating cilia is one of the emergent phenomena in biological processes at mesoscopic scales. Strong inter-ciliary couplings modify the natural beating frequencies,omega, of individual cilia to produce a collective motion that moves around a group frequency omega(m). Here we study the thermodynamic cost of synchronizing cilia arrays by mapping their dynamics onto a generic phase oscillator model. The model suggests that upon synchronization the mean heat dissipation rate is decomposed into two contributions, dissipation from each ciliums own natural driving force and dissipation arising from the interaction with other cilia, the latter of which can be interpreted as the one produced by a potential with a time-dependent protocol in the framework of our model. The spontaneous phase-synchronization of beating dynamics of cilia induced by strong inter-ciliary coupling is always accompanied with a significant reduction of dissipation for the cilia population, suggesting that organisms as a whole expend less energy by attaining a temporal order. At the level of individual cilia, however, a population of cilia with |omega|

  
  

  

• Active microrheology of a bulk metallic glass

  Title	: Active microrheology of a bulk metallic glass
  Journal	: SCIENCE ADVANCES, 2020

  
  

  논문

  NUMBER	P20038
  AUTHOR	Park, Hyunggyu,Rahbari, S. H. E.,Park, Hyunggyu
  TITLE	Active microrheology of a bulk metallic glass
  ARCHIVE
  FILE
  JOURNAL	SCIENCE ADVANCES, 2020
  ABSTRACT	The glass transition remains unclarified in condensed matter physics. Investigating the mechanical properties of glass is challenging because any global deformation that might result in shear rejuvenation would require a prohibitively long relaxation time. Moreover, glass is well known to be heterogeneous, and a global perturbation would prevent exploration of local mechanical/transport properties. However, investigation based on a local probe, i.e., microrheology, may overcome these problems. Here, we establish active microrheology of a bulk metallic glass, via a probe particle driven into host medium glass. This technique is amenable to experimental investigations via nanoindentation tests. We provide distinct evidence of a strong relationship between the microscopic dynamics of the probe particle and the macroscopic properties of the host medium glass. These findings establish active microrheology as a promising technique for investigating the local properties of bulk metallic glass.

  
  

  

• Exactly solvable two-terminal heat engine with asymmetric Onsager coefficients: Origin of the power-efficiency bound

  Title	: Exactly solvable two-terminal heat engine with asymmetric Onsager coefficients: Origin of the power-efficiency bound
  Journal	: PHYSICAL REVIEW E, 2020

  
  

  논문

  NUMBER	P20017
  AUTHOR	Park, Hyunggyu,Park, Jong-Min,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Exactly solvable two-terminal heat engine with asymmetric Onsager coefficients: Origin of the power-efficiency bound
  ARCHIVE	cond-mat/2003.01869
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2020
  ABSTRACT	An engine producing a finite power at the ideal (Carnot) efficiency is a dream engine which is not prohibited by the thermodynamic second law. Some years ago, a two-terminal heat engine with asymmetric Onsager coefficients in the linear response regime was suggested by Benenti et al. [Phys. Rev. Lett. 106, 230602 (2011)], as a prototypical system to make such a dream come true with nondivergent system parameter values. However, such a system has never been realized, in spite of many trials. Here, we introduce an exactly solvable two-terminal Brownian heat engine with the asymmetric Onsager coefficients in the presence of a Lorenz (magnetic) force. Nevertheless, we show that the dream engine regime cannot be accessible, even with the asymmetric Onsager coefficients, due to an instability keeping the engine from reaching its steady state. This is consistent with recent tradeoff relations between the engine power and efficiency, where the (cyclic) steady-state condition is implicitly presumed. We conclude that the inaccessibility to the dream engine originates from the steady-state constraint on the engine.

  
  

  

• Carnot Efficiency and Zero-Entropy Production Rate Do Not Guarantee Reversibility of a Process

  Title	: Carnot Efficiency and Zero-Entropy Production Rate Do Not Guarantee Reversibility of a Process
  Journal	: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2019

  
  

  논문

  NUMBER	Q19010
  AUTHOR	Park, Hyunggyu,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Carnot Efficiency and Zero-Entropy Production Rate Do Not Guarantee Reversibility of a Process
  ARCHIVE	cond-mat/1812.10651
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2019
  ABSTRACT	A thermodynamic process at a zero-entropy production (EP) rate has been regarded as a reversible process. A process achieving the Carnot efficiency is also considered a reversible process. Therefore, the condition, Carnot efficiency at zero-EP rate can be regarded as a strong condition for a reversible process. Here, however, we show that the detailed balance can be broken for a zero-EP rate process and even for a process achieving the Carnot efficiency at a zero-EP rate in an example of a quantum-dot model. This clearly demonstrates that Carnot efficiency at zero-EP rate or just zero-EP rate is not a sufficient condition for a reversible process.

  
  

  

• Thermodynamic uncertainty relation for underdamped Langevin systems driven by a velocity-dependent force

  Title	: Thermodynamic uncertainty relation for underdamped Langevin systems driven by a velocity-dependent force
  Journal	: PHYSICAL REVIEW E, 2019

  
  

  논문

  NUMBER	P19052
  AUTHOR	Park, Hyunggyu,Park, Jong-Min,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Thermodynamic uncertainty relation for underdamped Langevin systems driven by a velocity-dependent force
  ARCHIVE	cond-mat.stat-mech/1907.06221
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2019
  ABSTRACT	Recently, it has been shown that there is a trade-off relation between thermodynamic cost and current fluctuations, referred to as the thermodynamic uncertainty relation (TUR). The TUR has been derived for various processes, such as discrete-time Markov jump processes and overdamped Langevin dynamics. For underdamped dynamics, it has recently been reported that some modification is necessary for application of the TUR. However, the previous TUR for underdamped dynamics is not applicable to a system driven by a velocity-dependent force. In this study, we present a TUR, applicable to a system driven by a velocity-dependent force in the context of underdamped Langevin dynamics, by extending the theory of Vu and Hasegawa [Phys. Rev. E 100, 032130 (2019)]. We show that our TUR accurately describes the trade-off properties of a molecular refrigerator (cold damping), Brownian dynamics in a magnetic field, and an active particle system.

  
  

  

• Two-dimensional super-roughening in the three-dimensional Ising model

  Title	: Two-dimensional super-roughening in the three-dimensional Ising model
  Journal	: PHYSICAL REVIEW E, 2019

  
  

  논문

  NUMBER	P19069
  AUTHOR	Park, Hyunggyu,Dashti-Naserabadi, Hor,Rahbari, S. H. E.,Park, Hyunggyu
  TITLE	Two-dimensional super-roughening in the three-dimensional Ising model
  ARCHIVE	1912.01484
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2019
  ABSTRACT	We present a random-interface representation of the three-dimensional (3D) Ising model based on thermal fluctuations of a uniquely defined geometric spin cluster in the 3D model and its 2D cross section. Extensive simulations have been carried out to measure the global interfacial width as a function of temperature for different lattice sizes which is shown to signal the criticality of the model at T-c by forming a size-independent cusp in 3D, along with an emergent super-roughening at its 2D cross section. We find that the super-rough state is accompanied by an intrinsic anomalous scaling behavior in the local properties characterized by a set of geometric exponents which are the same as those for a pure 2D Ising model.

  
  

  

• Three heats in a strongly coupled system and bath

  Title	: Three heats in a strongly coupled system and bath
  Journal	: PHYSICAL REVIEW E, 2019

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Three heats in a strongly coupled system and bath
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2019
  ABSTRACT	We investigate three kinds of heat produced in a system and a bath strongly coupled via an interaction Hamiltonian. By studying the energy flows between the system, the bath, and their interaction, we provide rigorous definitions of two types of heat, Q(S) and Q(B), from the energy loss of the system and the energy gain of the bath, respectively. This is in contrast to the equivalence of Q(S) and Q(B), which is commonly assumed to hold in the weak-coupling regime. The bath we consider is equipped with a thermostat which enables it to reach an equilibrium. We identify another kind of heat Q(SB) from the energy dissipation of the bath into the superbath that provides the thermostat. We derive the fluctuation theorems (FTs) for the system variables and various heats, which are discussed in comparison with the FT for the total entropy production. We take an example of a sliding harmonic potential of a single Brownian particle in a fluid and calculate the three heats in a simplified model. These heats are found to equal, on average, in the steady state of energy, but show different fluctuations at all times.

  
  

  

• Nonuniversality of heat-engine efficiency at maximum power

  Title	: Nonuniversality of heat-engine efficiency at maximum power
  Journal	: PHYSICAL REVIEW E, 2018

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Um, Jaegon,Lee, Sang Hoon,Park, Hyunggyu
  TITLE	Nonuniversality of heat-engine efficiency at maximum power
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2018
  ABSTRACT	We study the efficiency of a simple quantum dot heat engine at maximum power. In contrast to the quasistatically operated Carnot engine whose efficiency reaches the theoretical maximum, recent research on more realistic engines operated in a finite time has revealed other classes of efficiencies such as the Curzon-Ahlborn efficiency maximizing the power. Such a power-maximizing efficiency has been argued to be always half of the maximum efficiency up to the linear order near equilibrium under the tight-coupling condition between thermodynamic fluxes. We show, however, that this universality may break down for the quantum dot heat engine, depending on the constraint imposed on the engine control parameters (local optimization), even though the tight-coupling condition remains satisfied. It is shown that this deviation is critically related to the applicability of the linear irreversible thermodynamics.

  
  

  

• Characterizing the nature of the rigidity transition

  Title	: Characterizing the nature of the rigidity transition
  Journal	: PHYSICAL REVIEW E, 2018

  
  

  논문

  NUMBER	P18104
  AUTHOR	Park, Hyunggyu,Rahbari, S. H. E.,Park, Hyunggyu
  TITLE	Characterizing the nature of the rigidity transition
  ARCHIVE	https://journals.aps.org/pre/pdf/10.1103/PhysRevE.
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2018
  ABSTRACT	Particulate matter, such as foams, emulsions, and granular materials, attain rigidity in a dense regime: the rigid phase can yield when a threshold force is applied. The rigidity transition in particulate matter exhibits bona fide scaling behavior near the transition point. However, a precise determination of exponents describing the rigidity transition has raised much controversy. Here we pinpoint the causes of the controversies. We then establish a conceptual framework to quantify the critical nature of the rigidity transition. Our results demonstrate that there is a spectrum of possible values for the critical exponents for which, without a robust framework, one cannot distinguish the genuine values of the exponents. Our approach is twofold: (1) a precise determination of the transition density using rheological measurements and (2) a matching rule that selects the critical exponents and rules out all other possibilities from the spectrum. This enables us to determine exponents with unprecedented accuracy and resolve the long-standing controversy over exponents of jamming The generality of the approach paves the way to quantify the critical nature of many other types of rheological phase transitions such as those in oscillatory shearing.

  
  

  

• Stochastic thermodynamics and hierarchy of fluctuation theorems with multiple reservoirs

  Title	: Stochastic thermodynamics and hierarchy of fluctuation theorems with multiple reservoirs
  Journal	: NEW JOURNAL OF PHYSICS, 2018

  
  

  논문

  NUMBER	Q18009
  AUTHOR	Park, Hyunggyu,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Stochastic thermodynamics and hierarchy of fluctuation theorems with multiple reservoirs
  ARCHIVE
  FILE
  JOURNAL	NEW JOURNAL OF PHYSICS, 2018
  ABSTRACT	We reformulate stochastic thermodynamics in terms of noise realizations for Langevin systems in contact with multiple reservoirs and investigate the structure of the second laws of thermodynamics. We derive a hierarchy of fluctuation theorems when one degree of freedom of the system is affected by multiple reservoirs simultaneously, that is, when noise-mixing occurs. These theorems and the associated second laws of thermodynamics put stricter bounds on the thermodynamics of Langevin systems. We apply our results to a stochastic machine in noise-mixing environments and demonstrate that our new bounds play a crucial role in determining the potential function and performance of the machine.

  
  

  

• Additivity of multiple heat reservoirs in the Langevin equation

  Title	: Additivity of multiple heat reservoirs in the Langevin equation
  Journal	: PHYSICAL REVIEW E, 2018

  
  

  논문

  NUMBER	Q17062
  AUTHOR	Park, Hyunggyu,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Additivity of multiple heat reservoirs in the Langevin equation
  ARCHIVE	arXiv:1712.00972
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2018
  ABSTRACT	The Langevin equation greatly simplifies the mathematical expression of the effects of thermal noise by using only two terms, a dissipation term, and a random-noise term. The Langevin description was originally applied to a system in contact with a single heat reservoir; however, many recent studies have also adopted a Langevin description for systems connected to multiple heat reservoirs. This is accomplished through the introduction of a simple summation for the dissipation and random-noise terms associated with each reservoir. However, the validity of this simple addition has been the focus of only limited discussion and has raised several criticisms. Moreover, this additive description has never been either experimentally or numerically verified, rendering its validity is still an open question. Here we perform molecular dynamics simulations for a Brownian system in simultaneous contact with multiple heat reservoirs to check the validity of this additive approach. Our simulation results confirm that the effect of multiple heat reservoirs is additive in general. A very small deviation in the total amount of dissipation and associated noise is found but seems not significant within statistical errors. We find that the steady-state properties satisfy the additivity perfectly and are not affected by this deviation.

  
  

  

• Entropy and Thermodynamic Second Laws: New Perspective - Stochastic Thermodynamics and Fluctuation Theorems

  Title	: Entropy and Thermodynamic Second Laws: New Perspective - Stochastic Thermodynamics and Fluctuation Theorems
  Journal	: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2018

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Entropy and Thermodynamic Second Laws: New Perspective - Stochastic Thermodynamics and Fluctuation Theorems
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2018
  ABSTRACT	Recently, there has been a considerable progress on the issue of the thermodynamic second law, which is known as the law of entropy increase or irreversibility. In particular, a novel symmetry known as the Gallavotti-Cohen symmetry is found in nonequilibrium (NEQ) fluctuations, which leads to so-called fluctuation theorems. The thermodynamic second law is a simple corollary of fluctuation theorems, from which one can predict quantitatively how often NEQ processes violate the law of entropy increase. Violations disappear in the thermodynamic limit, but can be observed reasonably well in small systems. In this article, we will briefly introduce the stochastic thermodynamics and derive various fluctuation theorems, including the total entropy production (EP), the work-free-energy relation, the excess and house-keeping EP, and the information entropy.

  
  

  

• Carnot efficiency is reachable in an irreversible process

  Title	: Carnot efficiency is reachable in an irreversible process
  Journal	: SCIENTIFIC REPORTS, 2017

  
  

  논문

  NUMBER	Q17027
  AUTHOR	Park, Hyunggyu,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Carnot efficiency is reachable in an irreversible process
  ARCHIVE	arXiv:1611.07665
  FILE
  JOURNAL	SCIENTIFIC REPORTS, 2017
  ABSTRACT	In thermodynamics, there exists a conventional belief that the Carnot efficiency is reachable only in the reversible ( zero entropy production) limit of nearly reversible processes. However, there is no theorem proving that the Carnot efficiency is unattainable in an irreversible process. Here, we show that the Carnot efficiency is reachable in an irreversible process through investigation of the Feynman-Smoluchowski ratchet (FSR). We also show that it is possible to enhance the efficiency by increasing the irreversibility. Our result opens a new possibility of designing an efficient heat engine in a highly irreversible process and also answers the long-standing question of whether the FSR can operate with the Carnot efficiency.

  
  

  

• Nonequilibrium steady states in Langevin thermal systems

  Title	: Nonequilibrium steady states in Langevin thermal systems
  Journal	: PHYSICAL REVIEW E, 2017

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Lahiri, Sourabh,Park, Hyunggyu
  TITLE	Nonequilibrium steady states in Langevin thermal systems
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2017
  ABSTRACT	Equilibrium is characterized by its fundamental properties, such as the detailed balance, the fluctuation-dissipation relation, and no heat dissipation. Based on the stochastic thermodynamics, we show that these three properties are equivalent to each other in conventional Langevin thermal systems with microscopic reversibility. Thus, a conventional steady state has either all three properties (equilibrium) or none of them (nonequilibrium). In contrast, with velocity-dependent forces breaking the microscopic reversibility, we prove that the detailed balance and the fluctuation-dissipation relation mutually exclude each other, and no equivalence relation is possible between any two of the three properties. This implies that a steady state of Langevin systems with velocity-dependent forces may maintain some equilibrium properties but not all of them. Our results are illustrated with a few example systems.

  
  

  

• Characterizing rare fluctuations in soft particulate flows

  Title	: Characterizing rare fluctuations in soft particulate flows
  Journal	: NATURE COMMUNICATIONS, 2017

  
  

  논문

  NUMBER	P17027
  AUTHOR	Park, Hyunggyu,Rahbari, S. H. E.,Park, Hyunggyu
  TITLE	Characterizing rare fluctuations in soft particulate flows
  ARCHIVE
  FILE
  JOURNAL	NATURE COMMUNICATIONS, 2017
  ABSTRACT	Soft particulate media include a wide range of systems involving athermal dissipative particles both in non-living and biological materials. Characterization of flows of particulate media is of great practical and theoretical importance. A fascinating feature of these systems is the existence of a critical rigidity transition in the dense regime dominated by highly intermittent fluctuations that severely affects the flow properties. Here, we unveil the underlying mechanisms of rare fluctuations in soft particulate flows. We find that rare fluctuations have different origins above and below the critical jamming density and become suppressed near the jamming transition. We then conjecture a time-independent local fluctuation relation, which we verify numerically, and that gives rise to an effective temperature. We discuss similarities and differences between our proposed effective temperature with the conventional kinetic temperature in the system by means of a universal scaling collapse.

  
  

  

• Information thermodynamics for a multi-feedback process with time delay

  Title	: Information thermodynamics for a multi-feedback process with time delay
  Journal	: EPL, 2017

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Um, Jaegon,Kwon, Chulan,Park, Hyunggyu
  TITLE	Information thermodynamics for a multi-feedback process with time delay
  ARCHIVE
  FILE
  JOURNAL	EPL, 2017
  ABSTRACT	We investigate a measurement-feedback process of repeated operations with time delay. During a finite-time interval, measurement on the system is performed and the feedback protocol derived from the measurement outcome is applied with time delay. This protocol is maintained into the next interval until a new protocol from the next measurement is applied. Unlike a feedback process without delay, both memories associated with previous and present measurement outcomes are involved in the system dynamics, which naturally brings forth a joint system described by a system state and two memory states. The thermodynamic second law provides a lower bound for heat flow into a thermal reservoir by the (3-state) Shannon entropy change of the joint system. However, as the feedback protocol depends on memory states sequentially, we can deduce a tighter bound for heat flow by integrating out irrelevant memory states during dynamics. As a simple example, we consider the so-called cold damping feedback process where the velocity of a particle is measured and a dissipative feedback protocol is applied to decelerate the particle. We confirm that the heat flow is well above the tightest bound. We also examine the long-time limit of this feedback process, which turns out to exhibit an interesting instability transition as well as heating by controlling parameters such as measurement errors, time interval, protocol strength, and time delay length. We discuss the underlying mechanism for instability and heating, which might be unavoidable in reality. Copyright (C) EPLA, 2017

  
  

  

• Unconventional entropy production in the presence of momentum-dependent forces

  Title	: Unconventional entropy production in the presence of momentum-dependent forces
  Journal	: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2016

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Unconventional entropy production in the presence of momentum-dependent forces
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2016
  ABSTRACT	We investigate the unconventional nature of entropy production (EP) in nonequilibrium systems with odd-parity variables that change signs under time reversal. We consider the Brownian motion of a particle in contact with a heat reservoir, where the particles momentum is an odd-parity variable. In the presence of an external momentum-dependent force, the EP transferred to the environment is found to be not equivalent to the usual reservoir entropy change due to heat transfer. An additional unconventional contribution to the EP, which is crucial for maintaining the non-negativity of the (average) total EP enforced by the second law of thermodynamics, appears. A few examples are considered to elucidate the novel nature of the EP. We also discuss detailed balance conditions with a momentum-dependent force.

  
  

  

• Overdamped limit and inverse-friction expansion for Brownian motion in an inhomogeneous medium

  Title	: Overdamped limit and inverse-friction expansion for Brownian motion in an inhomogeneous medium
  Journal	: PHYSICAL REVIEW E, 2015

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Durang, Xavier,Park, Hyunggyu
  TITLE	Overdamped limit and inverse-friction expansion for Brownian motion in an inhomogeneous medium
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2015
  ABSTRACT	We revisit the problem of the overdamped (large-friction) limit of the Brownian dynamics in an inhomogeneous medium characterized by a position-dependent friction coefficient and a multiplicative noise (local temperature) in one-dimensional space. Starting from the Kramers equation and analyzing it through the expansion in terms of eigenfunctions of a quantum harmonic oscillator, we derive analytically the corresponding Fokker-Planck equation in the overdamped limit. The result is fully consistent with the previous finding by Sancho, San Miguel, and Durr [J. Stat. Phys. 28, 291 (1982)]. Our method allows us to generalize the Brinkmans hierarchy, and thus it would be straightforward to obtain higher-order corrections in a systematic inverse-friction expansion without any assumption. Our results are confirmed by numerical simulations for simple examples.

  
  

  

• Total cost of operating an information engine

  Title	: Total cost of operating an information engine
  Journal	: NEW JOURNAL OF PHYSICS, 2015

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Um, Jaegon,Park, Hyunggyu
  TITLE	Total cost of operating an information engine
  ARCHIVE
  FILE
  JOURNAL	NEW JOURNAL OF PHYSICS, 2015
  ABSTRACT	We study a two-level system controlled in a discrete feedback loop, modeling both the system and the controller in terms of stochastic Markov processes. We find that the extracted work, which is known to be bounded from above by the mutual information acquired during measurement, has to be compensated by an additional energy supply during the measurement process itself, which is bounded by the same mutual information from below. Our results confirm that the total cost of operating an information engine is in full agreement with the conventional second law of thermodynamics. We also consider the efficiency of the information engine as a function of the cycle time and discuss the operating condition for maximal power generation. Moreover, we find that the entropy production of our information engine is maximal for maximal efficiency, in sharp contrast to conventional reversible heat engines.

  
  

  

• Finite-size scaling, dynamic fluctuations, and hyperscaling relation in the Kuramoto model

  Title	: Finite-size scaling, dynamic fluctuations, and hyperscaling relation in the Kuramoto model
  Journal	: PHYSICAL REVIEW E, 2015

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Finite-size scaling, dynamic fluctuations, and hyperscaling relation in the Kuramoto model
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2015
  ABSTRACT	We revisit the Kuramoto model to explore the finite-size scaling (FSS) of the order parameter and its dynamic fluctuations near the onset of the synchronization transition, paying particular attention to effects induced by the randomness of the intrinsic frequencies of oscillators. For a population of size N, we study two ways of sampling the intrinsic frequencies according to the same given unimodal distribution g(omega). In the random case, frequencies are generated independently in accordance with g(omega), which gives rise to oscillator number fluctuation within any given frequency interval. In the regular case, the N frequencies are generated in a deterministic manner that minimizes the oscillator number fluctuations, leading to quasiuniformly spaced frequencies in the population. We find that the two samplings yield substantially different finite-size properties with clearly distinct scaling exponents. Moreover, the hyperscaling relation between the order parameter and its fluctuations is valid in the regular case, but it is violated in the random case. In this last case, a self-consistent mean-field theory that completely ignores dynamic fluctuations correctly predicts the FSS exponent of the order parameter but not its critical amplitude.

  
  

  

• Heat fluctuations and initial ensembles

  Title	: Heat fluctuations and initial ensembles
  Journal	: PHYSICAL REVIEW E, 2014

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Kim, Kwangmoo,Park, Hyunggyu
  TITLE	Heat fluctuations and initial ensembles
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2014
  ABSTRACT	Time-integrated quantities such as work and heat increase incessantly in time during nonequilibrium processes near steady states. In the long-time limit, the average values of work and heat become asymptotically equivalent to each other, since they only differ by a finite energy change in average. However, the fluctuation theorem (FT) for the heat is found not to hold with the equilibrium initial ensemble, while the FT for the work holds. This reveals an intriguing effect of everlasting initial memory stored in rare events. We revisit the problem of a Brownian particle in a harmonic potential dragged with a constant velocity, which is in contact with a thermal reservoir. The heat and work fluctuations are investigated with initial Boltzmann ensembles at temperatures generally different from the reservoir temperature. We find that, in the infinite-time limit, the FT for the work is fully recovered for arbitrary initial temperatures, while the heat fluctuations significantly deviate from the FT characteristics except for the infinite initial-temperature limit (a uniform initial ensemble). Furthermore, we succeed in calculating finite-time corrections to the heat and work distributions analytically, using the modified saddle point integral method recently developed by us. Interestingly, we find noncommutativity between the infinite-time limit and the infinite-initial-temperature limit for the probability distribution function (PDF) of the heat.

  
  

  

• The statistical mechanics of the coagulation-diffusion process with a stochastic reset

  Title	: The statistical mechanics of the coagulation-diffusion process with a stochastic reset
  Journal	: JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, 2014

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Durang, Xavier,Park, Hyunggyu
  TITLE	The statistical mechanics of the coagulation-diffusion process with a stochastic reset
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, 2014
  ABSTRACT	The effects of a stochastic reset, to its initial configuration, is studied in the exactly solvable one-dimensional coagulation-diffusion process. A finite resetting rate leads to a modified non-equilibrium stationary state. If, in addition, the input of particles at a fixed given rate is admitted, then a competition between the resetting and the input rates leads to a non-trivial behaviour of the particle-density in the stationary state. From the exact inter-particle probability distribution, a simple physical picture emerges: the reset mainly changes the behaviour at larger distance scales, while at smaller length scales, the non-trivial correlation of the model without a reset dominate.

  
  

  

• Nature of synchronization transitions in random networks of coupled oscillators

  Title	: Nature of synchronization transitions in random networks of coupled oscillators
  Journal	: PHYSICAL REVIEW E, 2014

  
  

  논문

  NUMBER
  AUTHOR	Um, Jaegon,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Nature of synchronization transitions in random networks of coupled oscillators
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2014
  ABSTRACT	We consider a system of phase oscillators with random intrinsic frequencies coupled through sparse random networks and investigate how the connectivity disorder affects the nature of collective synchronization transitions. Various distribution types of intrinsic frequencies are considered: uniform, unimodal, and bimodal distribution. We employ a heterogeneous mean-field approximation based on the annealed networks and also perform numerical simulations on the quenched Erdos-Renyi networks. We find that the connectivity disorder drastically changes the nature of the synchronization transitions. In particular, the quenched randomness completely wipes away the diversity of the transition nature, and only a continuous transition appears with the same mean-field exponent for all types of frequency distributions. The physical origin of this unexpected result is discussed.

  
  

  

• Work fluctuations in a time-dependent harmonic potential: Rigorous results beyond the overdamped limit

  Title	: Work fluctuations in a time-dependent harmonic potential: Rigorous results beyond the overdamped limit
  Journal	: PHYSICAL REVIEW E, 2013

  
  

  논문

  NUMBER
  AUTHOR	Noh, Jae Dong,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Work fluctuations in a time-dependent harmonic potential: Rigorous results beyond the overdamped limit
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2013
  ABSTRACT	We investigate the stochastic motion of a Brownian particle in the harmonic potential with a time-dependent force constant. It may describe the motion of a colloidal particle in an optical trap where the potential well is formed by a time-dependent field. We use the path integral formalism to solve the Langevin equation and the associated Fokker-Planck (Kramers) equation. Rigorous relations are derived to generate the probability density function for the time-dependent nonequilibrium work production beyond the overdamped limit. We find that the work distribution exhibits an exponential tail with a power-law prefactor, accompanied by an interesting oscillatory feature (multiple pseudo-locking-unlocking transitions) due to the inertial effect. Some exactly solvable cases are discussed in the overdamped limit.

  
  

  

• Modified saddle-point integral near a singularity for the large deviation function

  Title	: Modified saddle-point integral near a singularity for the large deviation function
  Journal	: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2013

  
  

  논문

  NUMBER	Q17037
  AUTHOR	Park, Hyunggyu,Lee, Jae Sung,Lee, Jae Sung,Park, Hyunggyu
  TITLE	Modified saddle-point integral near a singularity for the large deviation function
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2013
  ABSTRACT	Long-time-integrated quantities in stochastic processes, in or out of equilibrium, usually exhibit rare but huge fluctuations. Work or heat production is such a quantity, for which the probability distribution function displays an exponential decay characterized by the large deviation function (LDF). The LDF is often deduced from the cumulant generating function through the inverse Fourier transformation. The saddle-point integration method is a powerful technique to obtain the asymptotic results in the Fourier integral, but special care should be taken when the saddle point is located near a singularity of the integrand. In this paper, we present a modified saddle-point method to handle such a difficulty efficiently. We investigate the dissipated and injected heat production in equilibration processes with various initial conditions, for example, where the generating functions contain branch-cut singularities as well as power-law ones. Exploiting the new modified saddle-point integrations, we obtain the leading finite-time corrections for the LDFs, which are confirmed by numerical results.

  
  

  

• Multiple Dynamic Transitions in Nonequilibrium Work Fluctuations

  Title	: Multiple Dynamic Transitions in Nonequilibrium Work Fluctuations
  Journal	: PHYSICAL REVIEW LETTERS, 2013

  
  

  논문

  NUMBER
  AUTHOR	Noh, Jae Dong,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Multiple Dynamic Transitions in Nonequilibrium Work Fluctuations
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2013
  ABSTRACT	The time-dependent work probability distribution function P(W) is investigated analytically for a diffusing particle trapped by an anisotropic harmonic potential and driven by a nonconservative drift force in two dimensions. We find that the exponential tail shape of P(W) characterizing rare-event probabilities undergoes a sequence of dynamic transitions in time. These remarkable locking-unlocking type transitions result from an intricate interplay between a rotational mode induced by the nonconservative force and an anisotropic decaying mode due to the conservative attractive force. We expect that most of the high-dimensional dynamical systems should exhibit similar multiple dynamic transitions.

  
  

  

• Link-disorder fluctuation effects on synchronization in random networks

  Title	: Link-disorder fluctuation effects on synchronization in random networks
  Journal	: PHYSICAL REVIEW E, 2013

  
  

  논문

  NUMBER
  AUTHOR	Um, Jaegon,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Link-disorder fluctuation effects on synchronization in random networks
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2013
  ABSTRACT	We consider one typical system of oscillators coupled through disordered link configurations in networks, i.e., a finite population of coupled phase oscillators with distributed intrinsic frequencies on a random network. We investigate the collective synchronization behavior, paying particular attention to link-disorder fluctuation effects on the synchronization transition and its finite-size scaling (FSS). Extensive numerical simulations as well as the mean-field analysis have been performed. We find that link-disorder fluctuations effectively induce uncorrelated random fluctuations in frequency, resulting in the FSS exponent (nu) over tilde = 5/2, which is identical to that in the globally coupled case (no link disorder) with frequency-disorder fluctuations. DOI: 10.1103/PhysRevE.87.042105

  
  

  

• Everlasting initial memory threshold for rare events in equilibration processes

  Title	: Everlasting initial memory threshold for rare events in equilibration processes
  Journal	: PHYSICAL REVIEW E, 2013

  
  

  논문

  NUMBER	Q17038
  AUTHOR	Park, Hyunggyu,Lee, J. S.,Lee, J. S.,Park, Hyunggyu
  TITLE	Everlasting initial memory threshold for rare events in equilibration processes
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2013
  ABSTRACT	Conventional wisdom indicates that initial memory should decay away exponentially in time for general (noncritial) equilibration processes. In particular, time-integrated quantities such as heat are presumed to lose initial memory in a sufficiently long-time limit. However, we show that the large deviation function of time-integrated quantities may exhibit initial memory effect even in the infinite-time limit, if the system is initially prepared sufficiently far away from equilibrium. For a Brownian particle dynamics, as an example, we found a sharp finite threshold rigorously, beyond which the corresponding large deviation function contains everlasting initial memory. The physical origin for this phenomenon is explored with an intuitive argument and also from a toy model analysis. Our results can be applied to general nonequilibrium relaxation processes reaching (non)equilibrium steady states. DOI: 10.1103/PhysRevE.87.020104

  
  

  

• Fluctuation Theorems and Entropy Production with Odd-Parity Variables

  Title	: Fluctuation Theorems and Entropy Production with Odd-Parity Variables
  Journal	: PHYSICAL REVIEW LETTERS, 2013

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Fluctuation Theorems and Entropy Production with Odd-Parity Variables
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2013
  ABSTRACT	We show that the total entropy production in stochastic processes with odd-parity variables (under time reversal) is separated into three parts, only two of which satisfy the integral fluctuation theorems in general. One is the usual excess contribution that can appear only transiently and is called nonadiabatic. Another one is attributed solely to the breakage of detailed balance. The last part that does not satisfy the fluctuation theorem comes from the steady-state distribution asymmetry for odd-parity variables that is activated in a nontransient manner. The latter two parts combine together as the housekeeping (adiabatic) contribution, whose positivity is not guaranteed except when the excess contribution completely vanishes. Our finding reveals that the equilibrium requires the steady-state distribution symmetry for odd-parity variables independently, in addition to the usual detailed balance. DOI: 10.1103/PhysRevLett.110.050602

  
  

  

• Entanglement versus mutual information in quantum spin chains

  Title	: Entanglement versus mutual information in quantum spin chains
  Journal	: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2012

  
  

  논문

  NUMBER
  AUTHOR	Um, Jaegon,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Entanglement versus mutual information in quantum spin chains
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2012
  ABSTRACT	The quantum entanglement E of a bipartite quantum Ising chain is compared with the mutual information I between the two parts after a local measurement of the classical spin configuration. As the model is conformally invariant, the entanglement measured in its ground state at the critical point is known to obey a certain scaling form. Surprisingly, the mutual information of classical spin configurations is found to obey the same scaling form, although with a different prefactor. Moreover, we find that mutual information and the entanglement obey the inequality I <= E in the ground state as well as in a dynamically evolving situation. This inequality holds for general bipartite systems in a pure state and can be proved using similar techniques as for Holevos bound.

  
  

  

• Rectification of Spatial Disorder

  Title	: Rectification of Spatial Disorder
  Journal	: PHYSICAL REVIEW LETTERS, 2012

  
  

  논문

  NUMBER	P11020
  AUTHOR	Park, Hyunggyu,Um, Jaegon,Park, Hyunggyu
  TITLE	Rectification of Spatial Disorder
  ARCHIVE	1104.4831
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2012
  ABSTRACT	We demonstrate that a large ensemble of noiseless globally coupled-pinned oscillators is capable of rectifying spatial disorder with spontaneous current activated through a dynamical phase transition mechanism, either of first or second order, depending on the profile of the pinning potential. In the presence of an external weak drive, the same collective mechanism can result in an absolute negative mobility, which, though not immediately related to symmetry breaking, is most prominent at the phase transition. Our results apply to a tug-of-war by competing molecular motors for bidirectional cargo transport.

  
  

  

• Continuity of the explosive percolation transition

  Title	: Continuity of the explosive percolation transition
  Journal	: PHYSICAL REVIEW E, 2011

  
  

  논문

  NUMBER	P11019
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Continuity of the explosive percolation transition
  ARCHIVE	1103.4439
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2011
  ABSTRACT	The explosive percolation problem on the complete graph is investigated via extensive numerical simulations. We obtain the cluster-size distribution at the moment when the cluster size heterogeneity becomes maximum. The distribution is found to be well described by the power-law form with the decay exponent tau = 2.06(2), followed by a hump. We then use the finite-size scaling method to make all the distributions at various system sizes up to N = 2(37) collapse perfectly onto a scaling curve characterized solely by the single exponent tau. We also observe that the instant of that collapse converges to a well-defined percolation threshold from below as N -> infinity. Based on these observations, we show that the explosive percolation transition in the model should be continuous, contrary to the widely spread belief of its discontinuity.

  
  

  

• Scaling of cluster heterogeneity in percolation transitions

  Title	: Scaling of cluster heterogeneity in percolation transitions
  Journal	: PHYSICAL REVIEW E, 2011

  
  

  논문

  NUMBER	P11029
  AUTHOR	Noh, Jae Dong,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Scaling of cluster heterogeneity in percolation transitions
  ARCHIVE	arXiv:1106.0354
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2011
  ABSTRACT	We investigate a critical scaling law for the cluster heterogeneity H in site and bond percolations in d-dimensional lattices with d = 2,...,6. The cluster heterogeneity is defined as the number of distinct cluster sizes. As an occupation probability p increases, the cluster size distribution evolves from a monodisperse distribution to a polydisperse one in the subcritical phase, and back to a monodisperse one in the supercritical phase. We show analytically that H diverges algebraically, approaching the percolation critical point p(c) as H similar to vertical bar p - p(c)vertical bar(-1/sigma) with the critical exponent sigma associated with the characteristic cluster size. Interestingly, its finite-size-scaling behavior is governed by a new exponent v(H) = (1 + d(f)/d)v, where d(f) is the fractal dimension of the critical percolating cluster and v is the correlation length exponent. The corresponding scaling variable defines a singular path to the critical point. All results are confirmed by numerical simulations.

  
  

  

• Nonequilibrium fluctuations for linear diffusion dynamics

  Title	: Nonequilibrium fluctuations for linear diffusion dynamics
  Journal	: PHYSICAL REVIEW E, 2011

  
  

  논문

  NUMBER	P11018
  AUTHOR	Noh, Jae Dong,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Nonequilibrium fluctuations for linear diffusion dynamics
  ARCHIVE	1102.2973
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2011
  ABSTRACT	We present the theoretical study on nonequilibrium (NEQ) fluctuations for diffusion dynamics in high dimensions driven by a linear drift force. We consider a general situation in which NEQ is caused by two conditions: (i) drift force not derivable from a potential function, and (ii) diffusion matrix not proportional to the unit matrix, implying nonidentical and correlated multidimensional noise. The former is a well-known NEQ source and the latter can be realized in the presence of multiple heat reservoirs or multiple noise sources. We develop a statistical mechanical theory based on generalized thermodynamic quantities such as energy, work, and heat. The NEQ fluctuation theorems are reproduced successfully. We also find the time-dependent probability distribution function exactly as well as the NEQ work production distribution P(W) in terms of solutions of nonlinear differential equations. In addition, we compute low-order cumulants of the NEQ work production explicitly. In two dimensions, we carry out numerical simulations to check out our analytic results and also to get P(W). We find an interesting dynamic phase transition in the exponential tail shape of P(W), associated with a singularity found in solutions of the nonlinear differential equation. Finally, we discuss possible realizations in experiments.

  
  

  

• Collective helping and bystander effects in coevolving helping networks

  Title	: Collective helping and bystander effects in coevolving helping networks
  Journal	: PHYSICAL REVIEW E, 2010

  
  

  논문

  NUMBER	P10008
  AUTHOR	Park, Hyunggyu,Lee, Hyun Keun,Jo, Hang-Hyun,Park, Hyunggyu
  TITLE	Collective helping and bystander effects in coevolving helping networks
  ARCHIVE	1003.5023
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2010
  ABSTRACT	We study collective helping behavior and bystander effects in a coevolving helping network model. A node and a link of the network represents an agent who renders or receives help and a friendly relation between agents, respectively. A helping trial of an agent depends on relations with other involved agents and its result (success or failure) updates the relation between the helper and the recipient. We study the network link dynamics and its steady states analytically and numerically. The full phase diagram is presented with various kinds of active and inactive phases and the nature of phase transitions are explored. We find various interesting bystander effects, consistent with the field study results, of which the underlying mechanism is proposed.

  
  

  

• Critical behavior of the Ising model in annealed scale-free networks

  Title	: Critical behavior of the Ising model in annealed scale-free networks
  Journal	: PHYSICAL REVIEW E, 2009

  
  

  논문

  NUMBER	P09059
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Critical behavior of the Ising model in annealed scale-free networks
  ARCHIVE	0909.1597
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2009
  ABSTRACT	We study the critical behavior of the Ising model in annealed scale-free (SF) networks of finite system size with forced upper cutoff in degree. By mapping the model onto the weighted fully connected Ising model, we derive analytic results for the finite-size scaling (FSS) near the phase transition, characterized by the cutoff-dependent two-parameter scaling with four distinct scaling regimes, in highly heterogeneous networks. These results are essentially the same as those found for the nonequilibrium contact process in annealed SF networks, except for an additional complication due to the trivial critical point shift in finite systems. The discrepancy of the FSS theories between annealed and quenched SF networks still remains in the equilibrium Ising model, like some other nonequilibrium models. All of our analytic results are confirmed reasonably well by numerical simulations.

  
  

  

• Relaxation dynamics of an elastic string in random media

  Title	: Relaxation dynamics of an elastic string in random media
  Journal	: PHYSICAL REVIEW E, 2009

  
  

  논문

  NUMBER	P09058
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Relaxation dynamics of an elastic string in random media
  ARCHIVE	0908.4154
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2009
  ABSTRACT	We investigate numerically the relaxation dynamics of an elastic string in two-dimensional random media by thermal fluctuations starting from a flat configuration. Measuring spatial fluctuations of its mean position, we find that the correlation length grows in time asymptotically as xi similar to(ln t)(1/chi approximate to). This implies that the relaxation dynamics is driven by thermal activations over random energy barriers which scale as E-B(l)similar to l(chi approximate to) with a length scale l. Numerical data strongly suggest that the energy barrier exponent chi approximate to is identical to the energy fluctuation exponent chi=1/3. We also find that there exists a long transient regime, where the correlation length follows a power-law dynamics as xi similar to t(1/z) with a nonuniversal dynamic exponent z. The origin of the transient scaling behavior is discussed in the context of the relaxation dynamics on finite ramified clusters of disorder.

  
  

  

• Crossover from the parity-conserving pair contact process with diffusion to other universality classes

  Title	: Crossover from the parity-conserving pair contact process with diffusion to other universality classes
  Journal	: PHYSICAL REVIEW E, 2009

  
  

  논문

  NUMBER	P09013
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Crossover from the parity-conserving pair contact process with diffusion to other universality classes
  ARCHIVE	0903.4222
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2009
  ABSTRACT	The pair contact process with diffusion (PCPD) with modulo 2 conservation (PCPD2) [2A -> 4A, 2A -> 0] is studied in one dimension, focused on the crossover to other well established universality classes: the directed Ising (DI) and the directed percolation (DP). First, we show that the PCPD2 shares the critical behaviors with the PCPD, both with and without directional bias. Second, the crossover from the PCPD2 to the DI is studied by including a parity-conserving single-particle process (A -> 3A). We find the crossover exponent 1/phi(1)=0.57(3), which is argued to be identical to that of the PCPD-to-DP crossover by adding A -> 2A. This suggests that the PCPD universality class has a well-defined fixed point distinct from the DP. Third, we study the crossover from a hybrid-type reaction-diffusion process belonging to the DP [3A -> 5A, 2A -> 0] to the DI by adding A -> 3A. We find 1/phi(2)=0.73(4) for the DP-to-DI crossover. The inequality of phi(1) and phi(2) further supports the non-DP nature of the PCPD scaling. Finally, we introduce a symmetry-breaking field in the dual spin language to study the crossover from the PCPD2 to the DP. We find 1/phi(3)=1.23(10), which is associated with a new independent route from the PCPD to the DP.

  
  

  

• Critical behavior of the contact process in annealed scale-free networks

  Title	: Critical behavior of the contact process in annealed scale-free networks
  Journal	: PHYSICAL REVIEW E, 2009

  
  

  논문

  NUMBER	P09004
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Critical behavior of the contact process in annealed scale-free networks
  ARCHIVE	0811.4199
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2009
  ABSTRACT	The critical behavior of the contact process is studied in annealed scale-free networks by mapping it on the random-walk problem. We obtain the analytic results for the critical scaling using the event-driven dynamics approach. These results are confirmed by numerical simulations. The disorder fluctuation induced by the sampling disorder in annealed networks is also explored. Finally, we discuss over a possible discrepancy of the finite-size-scaling theory in annealed and quenched networks in spirit of the droplet size scale and the linking disorder fluctuation.

  
  

  

• Kinetics of a non-Glauberian Ising model: global observables and exact results

  Title	: Kinetics of a non-Glauberian Ising model: global observables and exact results
  Journal	: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2009

  
  

  논문

  NUMBER	P09003
  AUTHOR	Dutta, Sreedhar B.,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Kinetics of a non-Glauberian Ising model: global observables and exact results
  ARCHIVE	0901.3428
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2009
  ABSTRACT	We analyse the spin-flip dynamics in kinetic Ising chains with Kimball-Deker-Haake transition rates, and evaluate exactly the evolution of global quantities like magnetization and its fluctuations, and the two-time susceptibilities and correlations of the global spin and the global 3-spin. Information on the ageing behaviour after a quench to zero temperature is extracted.

  
  

  

• EMBEDDINGS OF LINE IN THE PLANE AND ABHYANKAR-MOH EPIMORPHISM THEOREM

  Title	: EMBEDDINGS OF LINE IN THE PLANE AND ABHYANKAR-MOH EPIMORPHISM THEOREM
  Journal	: BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2009

  
  

  논문

  NUMBER	C09012
  AUTHOR	Park, Hyungju,Park, Hyungju
  TITLE	EMBEDDINGS OF LINE IN THE PLANE AND ABHYANKAR-MOH EPIMORPHISM THEOREM
  ARCHIVE
  FILE
  JOURNAL	BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2009
  ABSTRACT	In this paper, we consider the parameter space of the rational plane curves with uni-branched singularity. We show that such a parameter space is decomposable into irreducible components which are rational varieties. Rational parametrizations of the irreducible components are given in a constructive way, by a repeated use of Abhyankar-Moh Epimorphism Theorem. We compute an enumerative invariant of this parameter space, and include explicit computational examples to recover some classically-known invariants.

  
  

  

• Three different routes from the directed Ising to the directed percolation class

  Title	: Three different routes from the directed Ising to the directed percolation class
  Journal	: PHYSICAL REVIEW E, 2008

  
  

  논문

  NUMBER	P08058
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Three different routes from the directed Ising to the directed percolation class
  ARCHIVE	0807.3450
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2008
  ABSTRACT	The scaling nature of absorbing critical phenomena is well understood for the directed percolation (DP) and the directed Ising (DI) systems. However, a full analysis of the crossover behavior is still lacking, which is of our interest in this study. In one dimension, we find three different routes from the DI to the DP classes by introducing a symmetry-breaking field (SB), breaking a modulo 2 conservation (CB), or making channels connecting two equivalent absorbing states (CC). Each route can be characterized by a crossover exponent, which is found numerically as phi=2.1 +/- 0.1 (SB), 4.6 +/- 0.2 (CB), and 2.9 +/- 0.1 (CC), respectively. The difference between the SB and CB crossover can be understood easily in the domain wall language, while the CC crossover involves an additional critical singularity in the auxiliary field density with the memory effect to identify itself independent.

  
  

  

• Nonequilibrium phase transitions into absorbing states

  Title	: Nonequilibrium phase transitions into absorbing states
  Journal	: EUROPEAN PHYSICAL JOURNAL B, 2008

  
  

  논문

  NUMBER	P08004
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Nonequilibrium phase transitions into absorbing states
  ARCHIVE	0711.2197
  FILE
  JOURNAL	EUROPEAN PHYSICAL JOURNAL B, 2008
  ABSTRACT	Systems with absorbing (trapped) states may exhibit a nonequilibrium phase transition from a noise-free inactive phase into an ever-lasting active phase. We briefly review the absorbing critical phenomena and universality classes, and discuss over the controversial issues on the pair contact process with diffusion (PCPD). Two different approaches are proposed to clarify its universality issue, which unveil strong evidences that the PCPD belongs to a new universality class other than the directed percolation class.

  
  

  

• Boundary-induced abrupt transition in the symmetric exclusion process

  Title	: Boundary-induced abrupt transition in the symmetric exclusion process
  Journal	: PHYSICAL REVIEW E, 2008

  
  

  논문

  NUMBER	P08034
  AUTHOR	Park, Hyunggyu,Nagar, Apoorva,Park, Hyunggyu
  TITLE	Boundary-induced abrupt transition in the symmetric exclusion process
  ARCHIVE	0804.4212
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2008
  ABSTRACT	We investigate the role of the boundary in the symmetric simple exclusion process with competing nonlocal and local hopping events. With open boundaries, the system undergoes a first-order phase transition from a finite density phase to an empty road phase as the nonlocal hopping rate increases. Using a cluster stability analysis, we determine the location of such an abrupt nonequilibrium phase transition, which agrees well with numerical results. Our cluster analysis provides physical insight into the mechanism behind this transition. We also explain why the transition becomes discontinuous in contrast to the case with periodic boundary conditions, in which the continuous phase transition has been observed.

  
  

  

• Finite-size scaling of synchronized oscillation on complex networks

  Title	: Finite-size scaling of synchronized oscillation on complex networks
  Journal	: PHYSICAL REVIEW E, 2007

  
  

  논문

  NUMBER	P08003
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Finite-size scaling of synchronized oscillation on complex networks
  ARCHIVE	0710.1137
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2007
  ABSTRACT	The onset of synchronization in a system of random frequency oscillators coupled through a random network is investigated. Using a mean-field approximation, we characterize sample-to-sample fluctuations for networks of finite size, and derive the corresponding scaling properties in the critical region. For scale-free networks with the degree distribution P(k) similar to k(-gamma) at large k, we found that the finite-size exponent (nu) over bar takes on the value 5/2 when gamma > 5, the same as in the globally coupled Kuramoto model. For highly heterogeneous networks (3

  
  

  

• Entrainment transition in populations of random frequency oscillators

  Title	: Entrainment transition in populations of random frequency oscillators
  Journal	: PHYSICAL REVIEW LETTERS, 2007

  
  

  논문

  NUMBER	P07006
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Entrainment transition in populations of random frequency oscillators
  ARCHIVE	cond-mat/0701646
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2007
  ABSTRACT	The entrainment transition of coupled random frequency oscillators is revisited. The Kuramoto model (global coupling) is shown to exhibit unusual sample-dependent finite-size effects leading to a correlation size exponent (v) over bar = 5/2. Simulations of locally coupled oscillators in d dimensions reveal two types of frequency entrainment: mean-field behavior at d > 4 and aggregation of compact synchronized domains in three and four dimensions. In the latter case, scaling arguments yield a correlation length exponent v = 2/(d - 2), in good agreement with numerical results.

  
  

  

• Nontrivial critical crossover between directed percolation models: Effect of infinitely many absorbing states

  Title	: Nontrivial critical crossover between directed percolation models: Effect of infinitely many absorbing states
  Journal	: PHYSICAL REVIEW E, 2007

  
  

  논문

  NUMBER	P07029
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Nontrivial critical crossover between directed percolation models: Effect of infinitely many absorbing states
  ARCHIVE	0706.2973
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2007
  ABSTRACT	At nonequilibrium phase transitions into absorbing (trapped) states, it is well known that the directed percolation (DP) critical scaling is shared by two classes of models with a single (S) absorbing state and with infinitely many (IM) absorbing states. We study the crossover behavior in one dimension, arising from a considerable reduction of the number of absorbing states (typically from the IM-type to the S-type DP models) by following two different (excitatory or inhibitory) routes which make the auxiliary field density abruptly jump at the crossover. Along the excitatory route, the system becomes overly activated even for an infinitesimal perturbation and its crossover becomes discontinuous. Along the inhibitory route, we find a continuous crossover with universal crossover exponent phi similar or equal to 1.78(6), which is argued to be equal to nu(parallel to), the relaxation time exponent of the DP universality class on a general footing. This conjecture is also confirmed in the case of the directed Ising (parity-conserving) class. Finally, we discuss the effect of diffusion on the IM-type models and suggest an argument why diffusive models with some hybrid-type reactions should belong to the DP class.

  
  

  

• Construction of equilibrium networks with an energy function

  Title	: Construction of equilibrium networks with an energy function
  Journal	: JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, 2007

  
  

  논문

  NUMBER	P07038
  AUTHOR	Choi, M. Y.,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Construction of equilibrium networks with an energy function
  ARCHIVE	0707.0531
  FILE
  JOURNAL	JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, 2007
  ABSTRACT	We construct equilibrium networks by introducing an energy function depending on the degree of each node as well as the product of neighboring degrees. With this topological energy function, networks constitute a canonical ensemble, which follows the Boltzmann distribution for given temperature. It is observed that the system undergoes a topological phase transition from a random network to a star or a fully connected network as the temperature is lowered. Both mean-field analysis and numerical simulations reveal strong first-order phase transitions at temperatures which decrease logarithmically with the system size. Quantitative discrepancies of the simulation results from the mean-field prediction are discussed in view of the strong first-order nature.

  
  

  

• Finite-size scaling in complex networks

  Title	: Finite-size scaling in complex networks
  Journal	: PHYSICAL REVIEW LETTERS, 2007

  
  

  논문

  NUMBER	P06024
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Finite-size scaling in complex networks
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2007
  ABSTRACT	A finite-size-scaling (FSS) theory is proposed for various models in complex networks. In particular, we focus on the FSS exponent, which plays a crucial role in analyzing numerical data for finite-size systems. Based on the droplet-excitation (hyperscaling) argument, we conjecture the values of the FSS exponents for the Ising model, the susceptible-infected-susceptible model, and the contact process, all of which are confirmed reasonably well in numerical simulations.

  
  

  

• Dynamic instability transitions in one-dimensional driven diffusive flow with nonlocal hopping

  Title	: Dynamic instability transitions in one-dimensional driven diffusive flow with nonlocal hopping
  Journal	: PHYSICAL REVIEW E, 2007

  
  

  논문

  NUMBER	P07030
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Dynamic instability transitions in one-dimensional driven diffusive flow with nonlocal hopping
  ARCHIVE	cond-mat/0703604
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2007
  ABSTRACT	One-dimensional directed driven stochastic flow with competing nonlocal and local hopping events has an instability threshold from a populated phase into an empty-road (ER) phase. We implement this in the context of the asymmetric exclusion process. The nonlocal skids promote strong clustering in the stationary populated phase. Such clusters drive the dynamic phase transition and determine its scaling properties. We numerically establish that the instability transition into the ER phase is second order in the regime where the entry point reservoir controls the current and first order in the regime where the bulk is in control. The first-order transition originates from a turnabout of the cluster drift velocity. At the critical line, the current remains analytic, the road density vanishes linearly, and fluctuations scale as uncorrelated noise. A self-consistent cluster dynamics analysis explains why these scaling properties remain that simple.

  
  

  

• Comment on Non-Mean-Field behavior of the contact process on scale-free networks

  Title	: Comment on Non-Mean-Field behavior of the contact process on scale-free networks
  Journal	: PHYSICAL REVIEW LETTERS, 2007

  
  

  논문

  NUMBER	P06011
  AUTHOR	Ha, Meesoon,Park, Hyunggyu,Park, Hyunggyu
  TITLE	Comment on Non-Mean-Field behavior of the contact process on scale-free networks
  ARCHIVE	cond-mat/0603787
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2007
  ABSTRACT

  
  

  

• Anomalous binder cumulant and lack of self-averageness in systems with quenched disorder

  Title	: Anomalous binder cumulant and lack of self-averageness in systems with quenched disorder
  Journal	: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2006

  
  

  논문

  NUMBER	P06052
  AUTHOR	Park, Hyunggyu,Park, Hyunggyu
  TITLE	Anomalous binder cumulant and lack of self-averageness in systems with quenched disorder
  ARCHIVE	cond-mat/0611509
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2006
  ABSTRACT	The Binder cumulant (BC) has been widely used for locating the phase transition point accurately in systems with thermal noise. In systems with quenched disorder, the BC may show subtle finite-size effects due to large sample-to-sample fluctuations. We study the globally coupled Kuramoto model of interacting limit-cycle oscillators with random natural frequencies and find an anomalous dip in the BC near the transition. We show that the dip is related to non-self-averageness of the order parameter at the transition. Alternative definitions of the BC, which do not show any anomalous behavior regardless of the existence of non-self-averageness, are proposed.

  
  

  

• Equivalence of operator-splitting schemes for the integration of the Langevin equation

  Title	: Equivalence of operator-splitting schemes for the integration of the Langevin equation
  Journal	: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2006

  
  

  논문

  NUMBER	P06032
  AUTHOR	Park, Hyunggyu,Lee, H. K.,Park, Hyunggyu
  TITLE	Equivalence of operator-splitting schemes for the integration of the Langevin equation
  ARCHIVE	cond-mat/0607596
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT, 2006
  ABSTRACT	We investigate the equivalence of different operator-splitting schemes for the integration of the Langevin equation. We consider a specific problem, the so called directed percolation process, which can be extended to a wider class of problems. We first give a compact mathematical description of the operator-splitting method and introduce two typical splitting schemes that will be useful in numerical studies. We show that the two schemes are essentially equivalent through the map that turns out to be an automorphism. An associated equivalent class of operator-splitting integrations is also defined by generalizing the specified equivalence.

  
  

  

• Crossover from the pair contact process with diffusion to directed percolation

  Title	: Crossover from the pair contact process with diffusion to directed percolation
  Journal	: PHYSICAL REVIEW E, 2006

  
  

  논문

  NUMBER	P05074
  AUTHOR	Park, SC,Park, H,Park, H
  TITLE	Crossover from the pair contact process with diffusion to directed percolation
  ARCHIVE	cond-mat/0512076
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2006
  ABSTRACT	Crossover behaviors from the pair contact process with diffusion (PCPD) and the driven PCPD (DPCPD) to the directed percolation (DP) are studied in one dimension by introducing a single particle annihilation and/or branching dynamics. The crossover exponents phi are estimated numerically as 1/phi similar or equal to 0.58 +/- 0.03 for the PCPD and 1/phi similar or equal to 0.49 +/- 0.02 for the DPCPD. Nontriviality of the PCPD crossover exponent strongly supports the non-DP nature of the PCPD critical scaling, which is further evidenced by the anomalous critical amplitude scaling near the PCPD point. In addition, we find that the DPCPD crossover is consistent with the mean field prediction of the tricritical DP class as expected.

  
  

  

• Proceedings of the 13(th) Workshop on Statistical Physics - August 8-10, 2005 - Suwon, Korea

  Title	: Proceedings of the 13(th) Workshop on Statistical Physics - August 8-10, 2005 - Suwon, Korea
  Journal	: JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2006

  
  

  논문

  NUMBER
  AUTHOR	Park, H,Park, H
  TITLE	Proceedings of the 13(th) Workshop on Statistical Physics - August 8-10, 2005 - Suwon, Korea
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 2006
  ABSTRACT

  
  

  

• Generating function for particle-number probability distribution in directed percolation

  Title	: Generating function for particle-number probability distribution in directed percolation
  Journal	: JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL, 2005

  
  

  논문

  NUMBER	P05022
  AUTHOR	Park, SC,Park, H,Park, H
  TITLE	Generating function for particle-number probability distribution in directed percolation
  ARCHIVE	cond-mat/0502667
  FILE
  JOURNAL	JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL, 2005
  ABSTRACT	We derive a generic expression for the generating function (GF) of the particle-number probability distribution (PNPD) for a simple reaction diffusion model that belongs to the directed percolation universality class. Starting with a single particle on a lattice, we show that the GF of the PNPD can be written as an infinite series of cumulants taken at zero momentum. This series can be summed up into a complete form at the level of a mean-field approximation. Using the renormalization group techniques, we determine logarithmic corrections for the GF at the upper critical dimension. We also find the critical scaling form for the PNPD and check its universality numerically in one dimension. The critical scaling function is found to be universal up to two non-universal metric factors.

  
  

  

• Collective synchronization in spatially extended systems of coupled oscillators with random frequencies

  Title	: Collective synchronization in spatially extended systems of coupled oscillators with random frequencies
  Journal	: PHYSICAL REVIEW E, 2005

  
  

  논문

  NUMBER	P04032
  AUTHOR	Hong, H,Park, H,Park, H,Choi, MY
  TITLE	Collective synchronization in spatially extended systems of coupled oscillators with random frequencies
  ARCHIVE	cond-mat/0408553
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2005
  ABSTRACT	We study collective behavior of locally coupled limit-cycle oscillators with random intrinsic frequencies, spatially extended over d-dimensional hypercubic lattices. Phase synchronization as well as frequency entrainment are explored analytically in the linear (strong-coupling) regime and numerically in the nonlinear (weak-coupling) regime. Our analysis shows that the oscillator phases are always desynchronized up to d=4, which implies the lower critical dimension d(l)(P)=4 for phase synchronization. On the other hand, the oscillators behave collectively in frequency (phase velocity) even in three dimensions (d=3), indicating that the lower critical dimension for frequency entrainment is d(l)(F)=2. Nonlinear effects due to the periodic nature of limit-cycle oscillators are found to become significant in the weak-coupling regime: So-called runaway oscillators destroy the synchronized (ordered) phase and there emerges a fully random (disordered) phase. Critical behavior near the synchronization transition into the fully random phase is unveiled via numerical investigation. Collective behavior of globally coupled oscillators is also examined and compared with that of locally coupled oscillators.

  
  

  

• Asymmetrically coupled directed percolation systems

  Title	: Asymmetrically coupled directed percolation systems
  Journal	: PHYSICAL REVIEW LETTERS, 2005

  
  

  논문

  NUMBER	P05004
  AUTHOR	Park, H,Park, H
  TITLE	Asymmetrically coupled directed percolation systems
  ARCHIVE	cond-mat/0501542
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2005
  ABSTRACT	We introduce a dynamical model of coupled directed percolation systems with two particle species. The two species A and B are coupled asymmetrically in that A particles branch B particles, whereas B particles prey on A particles. This model may describe epidemic spreading controlled by reactive immunization agents. We study nonequilibrium phase transitions with attention focused on the multicritical point where both species undergo the absorbing phase transition simultaneously. In one dimension, we find that the inhibitory coupling from B to A is irrelevant and the model belongs to the unidirectionally coupled directed percolation class. On the contrary, a mean-field analysis predicts that the inhibitory coupling is relevant and a new universality appears with a variable dynamic exponent. Numerical simulations on small-world networks confirm our predictions.

  
  

  

• Slow relaxation in the Ising model on a small-world network with strong long-range interactions

  Title	: Slow relaxation in the Ising model on a small-world network with strong long-range interactions
  Journal	: PHYSICAL REVIEW E, 2005

  
  

  논문

  NUMBER	P05002
  AUTHOR	Choi, MY,Park, H,Park, H
  TITLE	Slow relaxation in the Ising model on a small-world network with strong long-range interactions
  ARCHIVE	cond-mat/0501099
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2005
  ABSTRACT	We consider the Ising model on a small-world network, where the long-range interaction strength J(2) is in general different from the local interaction strength J(1), and examine its relaxation behaviors as well as phase transitions. As J(2)/J(1) is raised from zero, the critical temperature also increases, manifesting contributions of long-range interactions to ordering. However, it becomes saturated eventually at large values of J(2)/J(1) and the system is found to display very slow relaxation, revealing that ordering dynamics is inhibited rather than facilitated by strong long-range interactions. To circumvent this problem, we propose a modified updating algorithm in Monte Carlo simulations, assisting the system to reach equilibrium quickly.

  
  

  

• Driven pair contact process with diffusion

  Title	: Driven pair contact process with diffusion
  Journal	: PHYSICAL REVIEW LETTERS, 2005

  
  

  논문

  NUMBER	P04026
  AUTHOR	Park, SC,Park, H,Park, H
  TITLE	Driven pair contact process with diffusion
  ARCHIVE	cond-mat/0406606
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, 2005
  ABSTRACT	The pair contact process with diffusion (PCPD) has been recently investigated extensively, but its critical behavior is not yet clearly established. By introducing biased diffusion, we show that the external driving is relevant and the driven PCPD exhibits a mean-field-type critical behavior even in one dimension. In systems which can be described by a single-species bosonic field theory, the Galilean invariance guarantees that the driving is irrelevant. The well-established directed percolation (DP) and parity-conserving (PC) classes are such examples. This leads us to conclude that the PCPD universality class should be distinct from the DP or the PC class. Moreover, it implies that the PCPD is generically a multispecies model and a field theory of two species is suitable for proper description.

  
  

  

• Scale-free dynamics emerging from information transfer

  Title	: Scale-free dynamics emerging from information transfer
  Journal	: EUROPHYSICS LETTERS, 2005

  
  

  논문

  NUMBER	P04048
  AUTHOR	Choi, MY,Park, H,Park, H
  TITLE	Scale-free dynamics emerging from information transfer
  ARCHIVE	cond-mat/0412156
  FILE
  JOURNAL	EUROPHYSICS LETTERS, 2005
  ABSTRACT	The dynamics based on information transfer is proposed as an underlying mechanism for the scale-invariant dynamic critical behavior observed in a variety of systems. We apply the dynamics to the globally coupled Ising model, which is a,analytically tractable, mid show that dynamic criticality is indeed attained. Such emergence of criticality is confirmed numerically in the two-dimensional Ising model as well as the globally coupled one and in a biological evolution model. Although criticality is precise only when information transfer is reversible, it may also be observed even in the irreversible case, during the practical time scale shorter than the relaxation time.

  
  

  

• Cluster mean-field approximations with the coherent-anomaly-method analysis for the driven pair contact process with diffusion

  Title	: Cluster mean-field approximations with the coherent-anomaly-method analysis for the driven pair contact process with diffusion
  Journal	: PHYSICAL REVIEW E, 2005

  
  

  논문

  NUMBER	P04034
  AUTHOR	Park, SC,Park, H,Park, H
  TITLE	Cluster mean-field approximations with the coherent-anomaly-method analysis for the driven pair contact process with diffusion
  ARCHIVE	cond-mat/0409115
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2005
  ABSTRACT	The cluster mean-field approximations are performed, up to 13 cluster sizes, to study the critical behavior of the driven pair contact process with diffusion (DPCPD) and its precedent, the PCPD in one dimension. Critical points are estimated by extrapolating our data to the infinite cluster size limit, which are in good accordance with recent simulation results. Within the cluster mean-field approximation scheme, the PCPD and the DPCPD share the same mean-field critical behavior. The application of the coherent anomaly method, however, shows that the two models develop different coherent anomalies, which lead to different true critical scaling. The values of the critical exponents for the particle density, the pair density, the correlation length, and the relaxation time are fairly well estimated for the DPCPD. These results support and complement our recent simulation results for the DPCPD.

  
  

  

• Collective phase synchronization in locally coupled limit-cycle oscillators

  Title	: Collective phase synchronization in locally coupled limit-cycle oscillators
  Journal	: PHYSICAL REVIEW E, 2004

  
  

  논문

  NUMBER	P03093
  AUTHOR	Hong, H,Park, H,Park, H,Choi, MY
  TITLE	Collective phase synchronization in locally coupled limit-cycle oscillators
  ARCHIVE	cond-mat/0312599
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2004
  ABSTRACT	We study collective behavior of locally coupled limit-cycle oscillators with scattered intrinsic frequencies on d-dimensional lattices. A linear analysis shows that the system should always be desynchronized up to d=4. On the other hand, numerical investigation for d=5 and d=6 reveals the emergence of the synchronized (ordered) phase via a continuous transition from the fully random desynchronized phase. This demonstrates that the lower critical dimension for the phase synchronization in this system is d(l)=4.

  
  

  

• Stability of vacuum in coupled directed percolation processes

  Title	: Stability of vacuum in coupled directed percolation processes
  Journal	: PHYSICAL REVIEW E, 2004

  
  

  논문

  NUMBER	P04020
  AUTHOR	Park, H,Park, H
  TITLE	Stability of vacuum in coupled directed percolation processes
  ARCHIVE	cond-mat/0403730
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2004
  ABSTRACT	We study the absorbing phase transitions in coupled directed percolation (DP) processes with N-species particles in one dimension. The interspecies coupling is linear, bidirectional, and excitatory. We find that the presence of a spontaneous annihilation process A-->0 is essential in stabilizing the absorbing phase (vacuum). In the coupled contact processes, the vacuum is stable and the system exhibits DP type transitions, regardless of the coupling strength, for all N. However, in the coupled branching annihilation random walks with one offspring (BAW), where particle annihilations occur only through binary diffusion processes A+A-->0, the vacuum becomes unstable with respect to an arbitrarily small branching rate in a sufficiently strong coupling regime for Ngreater than or equal to3. The N=2 BAW exhibits the DP type transition for any coupling strength, but the inclusion of interspecies hard core (HC) interaction makes the vacuum unstable again and the system is always active in a strong coupling regime. Critical behavior near the zero branching point is characterized by the mean-field scaling exponents, beta=nu(perpendicular to)=1/2 and nu(parallel to)=1, regardless of the presence of HC interaction. We also discuss the effects of the asymmetric coupling.

  
  

  

• Universality class of absorbing transitions with continuously varying critical exponents

  Title	: Universality class of absorbing transitions with continuously varying critical exponents
  Journal	: PHYSICAL REVIEW E, 2004

  
  

  논문

  NUMBER	P02084
  AUTHOR	Park, H,Park, H
  TITLE	Universality class of absorbing transitions with continuously varying critical exponents
  ARCHIVE	cond-mat/0109516
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2004
  ABSTRACT	The well-established universality classes of absorbing critical phenomena are directed percolation (DP) and directed Ising (DI) classes. Recently, the pair contact process with diffusion (PCPD) has been investigated extensively and claimed to exhibit a different type of critical phenomenon distinct from both DP and DI classes. Noticing that the PCPD possesses a long-term memory effect, we introduce a generalized version of the PCPD (GPCPD) with a parameter controlling the memory strength. The GPCPD connects the DP fixed point to the PCPD point continuously. Monte Carlo simulations strongly suggest that the GPCPD displays, to our knowledge, novel critical phenomena which are characterized by continuously varying critical exponents. The same critical behaviors are also observed in models where two species of particles are coupled cyclically. We present one possible scenario that the long-term memory may serve as a marginal perturbation to the ordinary DP fixed point.

  
  

  

• Comment on Restricted curvature model with suppression of extremal height

  Title	: Comment on Restricted curvature model with suppression of extremal height
  Journal	: PHYSICAL REVIEW E, 2003

  
  

  논문

  NUMBER	P03024
  AUTHOR	Park, H,Park, H
  TITLE	Comment on Restricted curvature model with suppression of extremal height
  ARCHIVE	cond-mat/0303301
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2003
  ABSTRACT	Recently Jeong and Kim [Phys. Rev. E 66, 051605 (2002)] investigated the scaling properties of equilibrium self-flattening surfaces subject to a restricted curvature constraint. In one dimension (1D), they found numerically that the stationary roughness exponent alphaapproximate to0.561 and the window exponent deltaapproximate to0.423. We present an analytic argument for general self-flattening surfaces in D dimensions, leading to alpha=Dalpha(0)/(D+alpha(0)) and delta=D/(D+alpha(0)), where alpha(0) is the roughness exponent for equilibrium surfaces without the self-flattening mechanism. In case of surfaces subject to a restricted curvature constraint, it is known exactly that alpha(0)=3/2 in 1D, which leads to alpha=3/5 and delta=2/5. Small discrepancies between our analytic values and their numerical values may be attributed to finite size effects.

  
  

  

• Fluctuations of self-flattening surfaces

  Title	: Fluctuations of self-flattening surfaces
  Journal	: PHYSICAL REVIEW E, 2002

  
  

  논문

  NUMBER	P02082
  AUTHOR	Park, H,Park, H
  TITLE	Fluctuations of self-flattening surfaces
  ARCHIVE	cond-mat/0209576
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2002
  ABSTRACT	We study the scaling properties of self-flattening surfaces under global suppression on surface fluctuations. Evolution of self-flattening surfaces is described by restricted solid-on-solid type monomer deposition-evaporation model with reduced deposition (evaporation) at the globally highest (lowest) site. We find numerically that equilibrium surface fluctuations are anomalous with roughness exponent alphasimilar or equal to1/3 and dynamic exponent z(W)similar or equal to3/2 in one dimension (1D) and alpha=0 (log) and z(W)similar or equal to5/2 in 2D. Stationary roughness can be understood analytically by relating our model to the static self-attracting random walk model and the dissociative dimer-type deposition-evaporation model. In case of nonequilibrium growing-eroding surfaces, self-flattening dynamics turns out to be irrelevant and the normal Kardar-Parisi-Zhang universality is recovered in all dimensions.

  
  

  

• Dynamical surface structures in multiparticle-correlated surface growths

  Title	: Dynamical surface structures in multiparticle-correlated surface growths
  Journal	: PHYSICAL REVIEW E, 2002

  
  

  논문

  NUMBER	P02083
  AUTHOR	Park, H,Park, H
  TITLE	Dynamical surface structures in multiparticle-correlated surface growths
  ARCHIVE	cond-mat/0205427
  FILE
  JOURNAL	PHYSICAL REVIEW E, 2002
  ABSTRACT	We investigate the scaling properties of the interface fluctuation width for the Q-mer and Q-particle-correlated deposition-evaporation models. These models are constrained with a global conservation law that the particle number at each height is conserved modulo Q. In equilibrium, the stationary roughness is anomalous but universal with the roughness exponent alpha = 1/3, while the early time evolution shows nonuniversal behavior with the growth exponent beta varying with models and Q. Nonequilibrium surfaces display diverse growing and stationary behaviors. The Q-mer model shows a faceted structure, while the Q-particle-correlated model shows a macroscopically grooved structure.

  
  

  

• Title	:	Stochastic thermodynamics and hierarchy of fluctuation theorems with multiple reservoirs
  Journal	:	NEW JOURNAL OF PHYSICS, v.20, 83010, 2018

  
  

  논문

  NUMBER
  AUTHOR	Lee, Jae Sung; Park, Hyunggyu
  TITLE	Stochastic thermodynamics and hierarchy of fluctuation theorems with multiple reservoirs
  ARCHIVE
  FILE
  JOURNAL	NEW JOURNAL OF PHYSICS, v.20, 83010, 2018
  ABSTRACT	We reformulate stochastic thermodynamics in terms of noise realizations for Langevin systems in contact with multiple reservoirs and investigate the structure of the second laws of thermodynamics. We derive a hierarchy of fluctuation theorems when one degree of freedom of the system is affected by multiple reservoirs simultaneously, that is, when noise-mixing occurs. These theorems and the associated second laws of thermodynamics put stricter bounds on the thermodynamics of Langevin systems. We apply our results to a stochastic machine in noise-mixing environments and demonstrate that our new bounds play a crucial role in determining the potential function and performance of the machine.

  
  

  

• Title	:	Nonuniversality of heat-engine efficiency at maximum power
  Journal	:	PHYSICAL REVIEW E, 98(5), 52137, 2018

  
  

  논문

  NUMBER
  AUTHOR	Lee, Sang Hoon; Um, Jaegon; Park, Hyunggyu
  TITLE	Nonuniversality of heat-engine efficiency at maximum power
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 98(5), 52137, 2018
  ABSTRACT	We study the efficiency of a simple quantum dot heat engine at maximum power. In contrast to the quasistatically operated Carnot engine whose efficiency reaches the theoretical maximum, recent research on more realistic engines operated in a finite time has revealed other classes of efficiencies such as the Curzon-Ahlborn efficiency maximizing the power. Such a power-maximizing efficiency has been argued to be always half of the maximum efficiency up to the linear order near equilibrium under the tight-coupling condition between thermodynamic fluxes. We show, however, that this universality may break down for the quantum dot heat engine, depending on the constraint imposed on the engine control parameters (local optimization), even though the tight-coupling condition remains satisfied. It is shown that this deviation is critically related to the applicability of the linear irreversible thermodynamics.

  
  

  

• Title	:	Entropy and Thermodynamic Second Laws: New Perspective - Stochastic Thermodynamics and Fluctuation Theorems
  Journal	:	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 72(15), 1413-1420, 2018

  
  

  논문

  NUMBER
  AUTHOR	Park, Hyunggyu
  TITLE	Entropy and Thermodynamic Second Laws: New Perspective - Stochastic Thermodynamics and Fluctuation Theorems
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY, 72(15), 1413-1420, 2018
  ABSTRACT	Recently, there has been a considerable progress on the issue of the thermodynamic second law, which is known as the law of entropy increase or irreversibility. In particular, a novel symmetry known as the Gallavotti-Cohen symmetry is found in nonequilibrium (NEQ) fluctuations, which leads to so-called fluctuation theorems. The thermodynamic second law is a simple corollary of fluctuation theorems, from which one can predict quantitatively how often NEQ processes violate the law of entropy increase. Violations disappear in the thermodynamic limit, but can be observed reasonably well in small systems. In this article, we will briefly introduce the stochastic thermodynamics and derive various fluctuation theorems, including the total entropy production (EP), the work-free-energy relation, the excess and house-keeping EP, and the information entropy.

  
  

  

• Title	:	Characterizing the nature of the rigidity transition
  Journal	:	PHYSICAL REVIEW E, 98(5), 52905, 2018

  
  

  논문

  NUMBER
  AUTHOR	Rahbari, S. H. E.; Vollmer, J.; Park, Hyunggyu
  TITLE	Characterizing the nature of the rigidity transition
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 98(5), 52905, 2018
  ABSTRACT	Particulate matter, such as foams, emulsions, and granular materials, attain rigidity in a dense regime: the rigid phase can yield when a threshold force is applied. The rigidity transition in particulate matter exhibits bona fide scaling behavior near the transition point. However, a precise determination of exponents describing the rigidity transition has raised much controversy. Here we pinpoint the causes of the controversies. We then establish a conceptual framework to quantify the critical nature of the rigidity transition. Our results demonstrate that there is a spectrum of possible values for the critical exponents for which, without a robust framework, one cannot distinguish the genuine values of the exponents. Our approach is twofold: (1) a precise determination of the transition density using rheological measurements and (2) a matching rule that selects the critical exponents and rules out all other possibilities from the spectrum. This enables us to determine exponents with unprecedented accuracy and resolve the long-standing controversy over exponents of jamming The generality of the approach paves the way to quantify the critical nature of many other types of rheological phase transitions such as those in oscillatory shearing.

  
  

  

• Title	:	Additivity of multiple heat reservoirs in the Langevin equation
  Journal	:	PHYSICAL REVIEW E, 97(6), 62135, 2018

  
  

  논문

  NUMBER
  AUTHOR	Lee, Jae Sung; Park, Hyunggyu
  TITLE	Additivity of multiple heat reservoirs in the Langevin equation
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, 97(6), 62135, 2018
  ABSTRACT	The Langevin equation greatly simplifies the mathematical expression of the effects of thermal noise by using only two terms, a dissipation term, and a random-noise term. The Langevin description was originally applied to a system in contact with a single heat reservoir; however, many recent studies have also adopted a Langevin description for systems connected to multiple heat reservoirs. This is accomplished through the introduction of a simple summation for the dissipation and random-noise terms associated with each reservoir. However, the validity of this simple addition has been the focus of only limited discussion and has raised several criticisms. Moreover, this additive description has never been either experimentally or numerically verified, rendering its validity is still an open question. Here we perform molecular dynamics simulations for a Brownian system in simultaneous contact with multiple heat reservoirs to check the validity of this additive approach. Our simulation results confirm that the effect of multiple heat reservoirs is additive in general. A very small deviation in the total amount of dissipation and associated noise is found but seems not significant within statistical errors. We find that the steady-state properties satisfy the additivity perfectly and are not affected by this deviation.

  
  

  

• Title	:	Information thermodynamics for a multi-feedback process with time delay
  Journal	:	EPL v.117(1), 10011. 2017

  
  

  논문

  NUMBER
  AUTHOR	Kwon, Chulan; Um, Jaegon; Park, Hyunggyu
  TITLE	Information thermodynamics for a multi-feedback process with time delay
  ARCHIVE
  FILE
  JOURNAL	EPL v.117(1), 10011. 2017
  ABSTRACT

  
  

  

• Title	:	Characterizing rare fluctuations in soft particulate flows
  Journal	:	NATURE COMMUNICATIONS v.8, 11. 2017.

  
  

  논문

  NUMBER	P17027
  AUTHOR	Rahbari, S. H. E.; Saberi, A. A.; Park, Hyunggyu; Vollmer, J.
  TITLE	Characterizing rare fluctuations in soft particulate flows
  ARCHIVE
  FILE
  JOURNAL	NATURE COMMUNICATIONS v.8, 11. 2017.
  ABSTRACT

  
  

  

• Title	:	Nonequilibrium steady states in Langevin thermal systems
  Journal	:	PHYSICAL REVIEW E v.96(2), 022134. 2017.

  
  

  논문

  NUMBER
  AUTHOR	Lee, Hyun Keun; Lahiri, Sourabh; Park, Hyunggyu
  TITLE	Nonequilibrium steady states in Langevin thermal systems
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E v.96(2), 022134. 2017.
  ABSTRACT

  
  

  

• Title	:	Carnot efficiency is reachable in an irreversible process
  Journal	:	SCIENTIFIC REPORTS v.7, 10725. 2017.

  
  

  논문

  NUMBER	Q17027
  AUTHOR	Lee, Jae Sung; Park, Hyunggyu
  TITLE	Carnot efficiency is reachable in an irreversible process
  ARCHIVE
  FILE
  JOURNAL	SCIENTIFIC REPORTS v.7, 10725. 2017.
  ABSTRACT

  
  

  

• Title	:	Unconventional entropy production in the presence of momentum-dependent forces
  Journal	:	JOURNAL OF THE KOREAN PHYSICAL SOCIETY v.68(5), 633-638p. 2016.

  
  

  논문

  NUMBER
  AUTHOR	Kwon, Chulan; Yeo, Joonhyun; Lee, Hyun Keun; Park, Hyunggyu
  TITLE	Unconventional entropy production in the presence of momentum-dependent forces
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF THE KOREAN PHYSICAL SOCIETY v.68(5), 633-638p. 2016.
  ABSTRACT

  
  

  

• Title	:	Overdamped limit and inverse-friction expansion for Brownian motion in an inhomogeneous medium
  Journal	:	PHYSICAL REVIEW E, v.91 no.6 (2015) 062118

  
  

  논문

  NUMBER
  AUTHOR	Durang, X; Kwon, C; Park, H
  TITLE	Overdamped limit and inverse-friction expansion for Brownian motion in an inhomogeneous medium
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.91 no.6 (2015) 062118
  ABSTRACT

  
  

  

• Title	:	Total cost of operating an information engine
  Journal	:	NEW JOURNAL OF PHYSICS, v.17 (2015) 085001

  
  

  논문

  NUMBER
  AUTHOR	Um, J; Hinrichsen, H; Kwon, C; Park, H
  TITLE	Total cost of operating an information engine
  ARCHIVE
  FILE
  JOURNAL	NEW JOURNAL OF PHYSICS, v.17 (2015) 085001
  ABSTRACT

  
  

  

• Title	:	Finite-size scaling, dynamic fluctuations, and hyperscaling relation in the Kuramoto model
  Journal	:	PHYSICAL REVIEW E, v.92 no.2 (2015) 022122

  
  

  논문

  NUMBER
  AUTHOR	Hong, H; Chate, H; Tang, LH; Park, H
  TITLE	Finite-size scaling, dynamic fluctuations, and hyperscaling relation in the Kuramoto model
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.92 no.2 (2015) 022122
  ABSTRACT

  
  

  

• Title	:	Nature of synchronization transitions in random networks of coupled oscillators
  Journal	:	PHYSICAL REVIEW E, v.89 no.1 (2014) 012810

  
  

  논문

  NUMBER
  AUTHOR	Um, J; Hong, H; Park, H
  TITLE	Nature of synchronization transitions in random networks of coupled oscillators
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.89 no.1 (2014) 012810
  ABSTRACT

  
  

  

• Title	:	The statistical mechanics of the coagulation-diffusion process with a stochastic reset
  Journal	:	JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, v.47 no.4 (2014) 045002

  
  

  논문

  NUMBER
  AUTHOR	Durang, X; Henkel, M; Park, H
  TITLE	The statistical mechanics of the coagulation-diffusion process with a stochastic reset
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL, v.47 no.4 (2014) 045002
  ABSTRACT

  
  

  

• Title	:	Heat fluctuations and initial ensembles
  Journal	:	PHYSICAL REVIEW E, v.90 no.3 (2014) 032117

  
  

  논문

  NUMBER
  AUTHOR	Kim, K; Kwon, C; Park, H
  TITLE	Heat fluctuations and initial ensembles
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.90 no.3 (2014) 032117
  ABSTRACT

  
  

  

• Title	:	Fluctuation Theorems and Entropy Production with Odd-Parity Variables
  Journal	:	PHYSICAL REVIEW LETTERS, v.110 no.5 (2013) 050602

  
  

  논문

  NUMBER
  AUTHOR	Lee, HK; Kwon, C; Park, H
  TITLE	Fluctuation Theorems and Entropy Production with Odd-Parity Variables
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, v.110 no.5 (2013) 050602
  ABSTRACT

  
  

  

• Title	:	Everlasting initial memory threshold for rare events in equilibration processes
  Journal	:	PHYSICAL REVIEW E, v.87 no.2 (2013) 020104

  
  

  논문

  NUMBER
  AUTHOR	Lee, JS; Kwon, C; Park, H
  TITLE	Everlasting initial memory threshold for rare events in equilibration processes
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.87 no.2 (2013) 020104
  ABSTRACT

  
  

  

• Title	:	Link-disorder fluctuation effects on synchronization in random networks
  Journal	:	PHYSICAL REVIEW E, v.87 no.4 (2013) 042105

  
  

  논문

  NUMBER
  AUTHOR	Hong, H; Um, J; Park, H
  TITLE	Link-disorder fluctuation effects on synchronization in random networks
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.87 no.4 (2013) 042105
  ABSTRACT

  
  

  

• Title	:	Multiple Dynamic Transitions in Nonequilibrium Work Fluctuations
  Journal	:	PHYSICAL REVIEW LETTERS, v.111 no.13 (2013) 130601

  
  

  논문

  NUMBER
  AUTHOR	Noh, JD; Kwon, C; Park, H
  TITLE	Multiple Dynamic Transitions in Nonequilibrium Work Fluctuations
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, v.111 no.13 (2013) 130601
  ABSTRACT

  
  

  

• Title	:	Modified saddle-point integral near a singularity for the large deviation function
  Journal	:	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT (2013) P11002

  
  

  논문

  NUMBER
  AUTHOR	Lee, JS; Kwon, C; Park, H
  TITLE	Modified saddle-point integral near a singularity for the large deviation function
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT (2013) P11002
  ABSTRACT

  
  

  

• Title	:	Work fluctuations in a time-dependent harmonic potential: Rigorous results beyond the overdamped limit
  Journal	:	PHYSICAL REVIEW E, v.88 no.6 (2013) 062102

  
  

  논문

  NUMBER
  AUTHOR	Kwon, C; Noh, JD; Park, H
  TITLE	Work fluctuations in a time-dependent harmonic potential: Rigorous results beyond the overdamped limit
  ARCHIVE
  FILE
  JOURNAL	PHYSICAL REVIEW E, v.88 no.6 (2013) 062102
  ABSTRACT

  
  

  

• Title	:	Entanglement versus mutual information in quantum spin chains
  Journal	:	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT (2012) P10026

  
  

  논문

  NUMBER
  AUTHOR	Um, J; Park, H; Hinrichsen, H
  TITLE	Entanglement versus mutual information in quantum spin chains
  ARCHIVE
  FILE
  JOURNAL	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT (2012) P10026
  ABSTRACT

  
  

  

• Title	:	Rectification of spatial disorder
  Journal	:	PHYSICAL REVIEW LETTERS, v.108 no.6 (2012) 060601

  
  

  논문

  NUMBER
  AUTHOR	Jaegon Um, Hyunsuk Hong, Fabio Marchesoni, and Hyunggyu Park
  TITLE	Rectification of spatial disorder
  ARCHIVE	arXiv:1104.4831
  FILE
  JOURNAL	PHYSICAL REVIEW LETTERS, v.108 no.6 (2012) 060601
  ABSTRACT

  
  

  

• Title	:	Continuity of the explosive percolation transition
  Journal	:	Physical Review E 84, 020101(R) (2011/8/3)

  
  

  논문

  NUMBER
  AUTHOR	Hyun Keun Lee, Beom Jun Kim, and Hyunggyu Park
  TITLE	Continuity of the explosive percolation transition
  ARCHIVE
  FILE
  JOURNAL	Physical Review E 84, 020101(R) (2011/8/3)
  ABSTRACT

  
  

  

• Title	:	Scaling of cluster heterogeneity in percolation transitions
  Journal	:	Physical Review E 84, 010101(R) (2011/7/20)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh, Hyun Keun Lee, and Hyunggyu Park
  TITLE	Scaling of cluster heterogeneity in percolation transitions
  ARCHIVE
  FILE
  JOURNAL	Physical Review E 84, 010101(R) (2011/7/20)
  ABSTRACT

  
  

  

• Title	:	Non-equilibrium fluctuations for linear diffusion dynamics
  Journal	:	Physical Review E 83, 061145 (2011/6/24)

  
  

  논문

  NUMBER
  AUTHOR	Chulan Kwon, Jae Dong Noh and Hyunggyu Park
  TITLE	Non-equilibrium fluctuations for linear diffusion dynamics
  ARCHIVE
  FILE
  JOURNAL	Physical Review E 83, 061145 (2011/6/24)
  ABSTRACT

  
  

  

• Title	:	Collective helping and bystander effects in coevolving helping networks
  Journal	:	Phys. Rev. E 81, 066108(2010)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park
  TITLE	Collective helping and bystander effects in coevolving helping networks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 81, 066108(2010)
  ABSTRACT

  
  

  

• Title	:	Kinetics of a non-glauberian Ising model: global observables and exact results
  Journal	:	J. Stat. Mech. P03023 (2009)

  
  

  논문

  NUMBER
  AUTHOR	Sreedhar B. Dutta, Malte Henkel and Hyunggyu Park
  TITLE	Kinetics of a non-glauberian Ising model: global observables and exact results
  ARCHIVE
  FILE
  JOURNAL	J. Stat. Mech. P03023 (2009)
  ABSTRACT

  
  

  

• Title	:	Crossover from the parity-conserving pair contact process with diffusion to other universality classes
  Journal	:	Phys. Rev. E 79, 051130 (2009)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Crossover from the parity-conserving pair contact process with diffusion to other universality classes
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 79, 051130 (2009)
  ABSTRACT

  
  

  

• Title	:	Critical behavior of the contact process in annealed scale-free networks
  Journal	:	Phys. Rev. E 78, 041128 (2009)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh and Hyunggyu Park
  TITLE	Critical behavior of the contact process in annealed scale-free networks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 78, 041128 (2009)
  ABSTRACT

  
  

  

• Title	:	Relaxation dynamics of an elastic string in random media
  Journal	:	Phys. Rev. E 80, 040102(R) (2009)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh and Hyunggyu Park
  TITLE	Relaxation dynamics of an elastic string in random media
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 80, 040102(R) (2009)
  ABSTRACT

  
  

  

• Title	:	Critical behavior of the Ising model in annealed scale-free networks
  Journal	:	Phys. Rev. E 80, 051127 (2009)

  
  

  논문

  NUMBER
  AUTHOR	Sang Hoon Lee, Meesoon Ha, Hawoong Jeong, Jae Dong Noh, and Hyunggyu Park
  TITLE	Critical behavior of the Ising model in annealed scale-free networks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 80, 051127 (2009)
  ABSTRACT

  
  

  

• Title	:	Boundary-induced abrupt transition in the symmetric exclusion process
  Journal	:	Phys. Rev. E 77, 061118 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Apoorva Nagar, Meesoon Ha, and Hyunggyu Park
  TITLE	Boundary-induced abrupt transition in the symmetric exclusion process
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 77, 061118 (2008)
  ABSTRACT

  
  

  

• Title	:	Nonequilibrium phase transitions into absorbing states: Focused around the pair contact process with diffusion
  Journal	:	Eur. Phy. J. B 64, 415 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Nonequilibrium phase transitions into absorbing states: Focused around the pair contact process with diffusion
  ARCHIVE
  FILE
  JOURNAL	Eur. Phy. J. B 64, 415 (2008)
  ABSTRACT

  
  

  

• Title	:	Three different routes from the directed Ising to the directed percolation class
  Journal	:	Phys. Rev. E 78, 041128 (2008)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Three different routes from the directed Ising to the directed percolation class
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 78, 041128 (2008)
  ABSTRACT

  
  

  

• Title	:	Comment on “ Non-mean-field behavior of the contact process on scale-free networks”
  Journal	:	Phys. Rev. Lett. 98, 029801 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Meesoon Ha, H. Hong, and Hyunggyu Park
  TITLE	Comment on “ Non-mean-field behavior of the contact process on scale-free networks”
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 98, 029801 (2007)
  ABSTRACT

  
  

  

• Title	:	Finite-size scaling in complex networks
  Journal	:	Phys. Rev. Lett. 98, 258701 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Hyunsuk Hong, Meesoon Ha, and Hyunggyu Park
  TITLE	Finite-size scaling in complex networks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 98, 258701 (2007)
  ABSTRACT

  
  

  

• Title	:	Dynamic instability transitions in 1D driven diffusive flow with non-local hopping
  Journal	:	Phys. Rev. E 75, 061131 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Meesoon Ha, Hyunggyu Park, and Marcel den Nijs
  TITLE	Dynamic instability transitions in 1D driven diffusive flow with non-local hopping
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 75, 061131 (2007)
  ABSTRACT

  
  

  

• Title	:	Construction of equilibrium networks with an energy function
  Journal	:	J. Phys. A 40, 9723 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Daun Jeong, M. Y. Choi, and Hyunggyu Park
  TITLE	Construction of equilibrium networks with an energy function
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 40, 9723 (2007)
  ABSTRACT

  
  

  

• Title	:	Entrainment transition in populations of random frequency oscillators
  Journal	:	Phys. Rev. Lett. 99, 184101 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Hyunsuk Hong, Hyunggyu Park, and Lei-Han Tang
  TITLE	Entrainment transition in populations of random frequency oscillators
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 99, 184101 (2007)
  ABSTRACT

  
  

  

• Title	:	Nontrivial critical crossover between directed percolation models: Effect of infinitely many absorbing states
  Journal	:	Phys. Rev. E 76, 051123 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Nontrivial critical crossover between directed percolation models: Effect of infinitely many absorbing states
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 76, 051123 (2007)
  ABSTRACT

  
  

  

• Title	:	Finite-size scaling of synchronized oscillation on complex networks
  Journal	:	Phys. Rev. E 76, 066104 (2007)

  
  

  논문

  NUMBER
  AUTHOR	Hyunsuk Hong, Hyunggyu Park, and Lei-Han Tang
  TITLE	Finite-size scaling of synchronized oscillation on complex networks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 76, 066104 (2007)
  ABSTRACT

  
  

  

• Title	:	Crossover from the pair contact proces with diffusion to directed percolation
  Journal	:	Phys. Rev. E 73, 025105(R) (2006)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Crossover from the pair contact proces with diffusion to directed percolation
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 73, 025105(R) (2006)
  ABSTRACT

  
  

  

• Title	:	Equivalence of operator-splitting schemes for the integration of the Langevin equation
  Journal	:	J. Stat. Mech. P08021 (2006)

  
  

  논문

  NUMBER
  AUTHOR	H. K. Lee, C. Kwon, and Hyunggyu Park
  TITLE	Equivalence of operator-splitting schemes for the integration of the Langevin equation
  ARCHIVE
  FILE
  JOURNAL	J. Stat. Mech. P08021 (2006)
  ABSTRACT

  
  

  

• Title	:	Anomalous Binder cumulant and lack of self- averageness in systems with quenched disorder
  Journal	:	J. Korean Phys. Soc. 49, L1885 (2006)

  
  

  논문

  NUMBER
  AUTHOR	Hyunsuk Hong, Hyunggyu Park, and Lei-Han Tang
  TITLE	Anomalous Binder cumulant and lack of self- averageness in systems with quenched disorder
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 49, L1885 (2006)
  ABSTRACT

  
  

  

• Title	:	Cluster mean field approximations with the coherent anomaly method analysis for the driven pair contact process with diffusion
  Journal	:	Phys. Rev. E 71, 016137 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Cluster mean field approximations with the coherent anomaly method analysis for the driven pair contact process with diffusion
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 71, 016137 (2005)
  ABSTRACT

  
  

  

• Title	:	Scale-free dynamics emerging from information transfer
  Journal	:	Europhys. Lett. 69, 503 (2005)

  
  

  논문

  NUMBER
  AUTHOR	M. Y. Choi, Beom Jun Kim, B.-G. Yoon, and Hyunggyu Park
  TITLE	Scale-free dynamics emerging from information transfer
  ARCHIVE
  FILE
  JOURNAL	Europhys. Lett. 69, 503 (2005)
  ABSTRACT

  
  

  

• Title	:	Driven pair contact process with diffusion
  Journal	:	Phys. Rev. Lett. 94, 065701 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Su-Chan Park and Hyunggyu Park
  TITLE	Driven pair contact process with diffusion
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 94, 065701 (2005)
  ABSTRACT

  
  

  

• Title	:	Slow relaxation in the Ising model on a small-world network with strong long-range interactions
  Journal	:	Phys. Rev. E 71, 036103 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Daun Jeong, M. Y. Choi, and Hyunggyu Park
  TITLE	Slow relaxation in the Ising model on a small-world network with strong long-range interactions
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 71, 036103 (2005)
  ABSTRACT

  
  

  

• Title	:	Asymmetrically coupled directed percolation systems
  Journal	:	Phys. Rev. Lett. 94, 145702 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh and Hyunggyu Park
  TITLE	Asymmetrically coupled directed percolation systems
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 94, 145702 (2005)
  ABSTRACT

  
  

  

• Title	:	Generating function for particle-number probability distribution in directed percolation
  Journal	:	J. Phys. A 38, 8187 (2005)

  
  

  논문

  NUMBER
  AUTHOR	Lucian Anton, Hyunggyu Park, and Su-Chan Park
  TITLE	Generating function for particle-number probability distribution in directed percolation
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 38, 8187 (2005)
  ABSTRACT

  
  

  

• Title	:	Collective synchronization in spatially extended systems of coupled oscillators with random frequencies
  Journal	:	Phys. Rev. E 72, 036217 (2005)

  
  

  논문

  NUMBER
  AUTHOR	H. Hong, Hyunggyu Park, and M. Y. Choi
  TITLE	Collective synchronization in spatially extended systems of coupled oscillators with random frequencies
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 72, 036217 (2005)
  ABSTRACT

  
  

  

• Title	:	Universality class of absorbing transitions with continuously varying exponents
  Journal	:	Phys. Rev. E 69, 016122 (2004)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh and Hyunggyu Park
  TITLE	Universality class of absorbing transitions with continuously varying exponents
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 69, 016122 (2004)
  ABSTRACT

  
  

  

• Title	:	Stability of vacuum in coupled directed percolation processes
  Journal	:	Phys. Rev. E 69, 066125 (2004)

  
  

  논문

  NUMBER
  AUTHOR	Sungchul Kwon and Hyunggyu Park
  TITLE	Stability of vacuum in coupled directed percolation processes
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 69, 066125 (2004)
  ABSTRACT

  
  

  

• Title	:	Factors that predict better synchronizability on complex networks
  Journal	:	Phys. Rev. E 69, 067105 (2004)

  
  

  논문

  NUMBER
  AUTHOR	H. Hong, Beom Jun Kim, M. Y. Choi, and Hyunggyu Park
  TITLE	Factors that predict better synchronizability on complex networks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 69, 067105 (2004)
  ABSTRACT

  
  

  

• Title	:	Collective phase synchronization in locally-coupled limit-cycle oscillators
  Journal	:	Phys. Rev. E 70, 045204(R) (2004)

  
  

  논문

  NUMBER
  AUTHOR	H. Hong, Hyunggyu Park, and M. Y. Choi
  TITLE	Collective phase synchronization in locally-coupled limit-cycle oscillators
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 70, 045204(R) (2004)
  ABSTRACT

  
  

  

• Title	:	Comment on “Restricted curvature model with suppression of extremal height”
  Journal	:	Phys. Rev. E 68, 053601 (2003)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park
  TITLE	Comment on “Restricted curvature model with suppression of extremal height”
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 68, 053601 (2003)
  ABSTRACT

  
  

  

• Title	:	Dynamic surface structures in multiparticle-correlated surface growths
  Journal	:	Phys. Rev. E 66, 046123 (2002)

  
  

  논문

  NUMBER
  AUTHOR	Yup Kim, T. S. Kim, and Hyunggyu Park
  TITLE	Dynamic surface structures in multiparticle-correlated surface growths
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 66, 046123 (2002)
  ABSTRACT

  
  

  

• Title	:	Fluctuations of self-flattening surfaces
  Journal	:	Phys. Rev. E 66, 040602(R) (2002)

  
  

  논문

  NUMBER
  AUTHOR	Yup Kim, S. Y. Yoon, and Hyunggyu Park
  TITLE	Fluctuations of self-flattening surfaces
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 66, 040602(R) (2002)
  ABSTRACT

  
  

  

• Title	:	Relaxation of non-order parameter field in directed Ising systems
  Journal	:	J. Korean Phys. Soc. 38, 494 (2001)

  
  

  논문

  NUMBER
  AUTHOR	Heung Sik Park and Hyunggyu Park
  TITLE	Relaxation of non-order parameter field in directed Ising systems
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 38, 494 (2001)
  ABSTRACT

  
  

  

• Title	:	Two-species branching annihilating random walks with one offspring
  Journal	:	J. Korean Phys. Soc. 38, 490 (2001)

  
  

  논문

  NUMBER
  AUTHOR	Sungchul Kwon and Hyunggyu Park
  TITLE	Two-species branching annihilating random walks with one offspring
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 38, 490 (2001)
  ABSTRACT

  
  

  

• Title	:	Anomalous roughness, localization, and globally constrained random walks
  Journal	:	Phys. Rev. E 64, 046131 (2001)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh, Hyunggyu Park, Doochul Kim, and Marcel den Nijs
  TITLE	Anomalous roughness, localization, and globally constrained random walks
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 64, 046131 (2001)
  ABSTRACT

  
  

  

• Title	:	Absorbing-state critical phenomena in interacting surface reaction models
  Journal	:	Brazilian J. Phys. 30, 133 (2000)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Sungchul Kwon
  TITLE	Absorbing-state critical phenomena in interacting surface reaction models
  ARCHIVE
  FILE
  JOURNAL	Brazilian J. Phys. 30, 133 (2000)
  ABSTRACT

  
  

  

• Title	:	Anomalous roughness for dimer type surface growth
  Journal	:	Phys. Rev. Lett. 84, 3891 (2000)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh, Hyunggyu Park, and Marcel den Nijs
  TITLE	Anomalous roughness for dimer type surface growth
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 84, 3891 (2000)
  ABSTRACT

  
  

  

• Title	:	Does hard core interaction change absorbing-type critical phenomena?
  Journal	:	Phys. Rev. Lett. 85, 1682 (2000)

  
  

  논문

  NUMBER
  AUTHOR	Sungchul Kwon, Jysoo Lee, and Hyunggyu Park
  TITLE	Does hard core interaction change absorbing-type critical phenomena?
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 85, 1682 (2000)
  ABSTRACT

  
  

  

• Title	:	Directed Ising type dynamic preroughening transition in one dimensional interfaces
  Journal	:	Phys. Rev. E 59, 194 (1999)

  
  

  논문

  NUMBER
  AUTHOR	Jae Dong Noh, Hyunggyu Park, and Marcel den Nijs
  TITLE	Directed Ising type dynamic preroughening transition in one dimensional interfaces
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 59, 194 (1999)
  ABSTRACT

  
  

  

• Title	:	Interacting monomer-dimer model with infinitely many absorbing states
  Journal	:	Phys. Rev. E 59, 4683 (1999)

  
  

  논문

  NUMBER
  AUTHOR	WonMuk Hwang and Hyunggyu Park
  TITLE	Interacting monomer-dimer model with infinitely many absorbing states
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 59, 4683 (1999)
  ABSTRACT

  
  

  

• Title	:	Dynamic behavior of driven interfaces in models with two absorbing states
  Journal	:	Phys. Rev. E 59, 4949 (1999)

  
  

  논문

  NUMBER
  AUTHOR	Sungchul Kwon, WonMuk Hwang, and Hyunggyu Park
  TITLE	Dynamic behavior of driven interfaces in models with two absorbing states
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 59, 4949 (1999)
  ABSTRACT

  
  

  

• Title	:	Active width at a slanted active boundary in directed percolation
  Journal	:	Phys. Rev. E 60, 2496 (1999)

  
  

  논문

  NUMBER
  AUTHOR	Chun-Chung Chen, Hyunggyu Park, and Marcel den Nijs
  TITLE	Active width at a slanted active boundary in directed percolation
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 60, 2496 (1999)
  ABSTRACT

  
  

  

• Title	:	Particle dynamics in a mass-coalescence process
  Journal	:	J. Phys. A 32, L495 (1999)

  
  

  논문

  NUMBER
  AUTHOR	Meesoon Ha, Hyunggyu Park, and Marcel den Nijs
  TITLE	Particle dynamics in a mass-coalescence process
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 32, L495 (1999)
  ABSTRACT

  
  

  

• Title	:	Critical phenomena of nonequilibrium dynamical systems with two absorbing states
  Journal	:	Phys. Rev. E 57, 6438 (1998)

  
  

  논문

  NUMBER
  AUTHOR	WonMuk Hwang, Sungchul Kwon, Heungwon Park, and Hyunggyu Park
  TITLE	Critical phenomena of nonequilibrium dynamical systems with two absorbing states
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 57, 6438 (1998)
  ABSTRACT

  
  

  

• Title	:	Exact solutions of a restricted ballistic deposition model on a one-dimensional staircase
  Journal	:	Phys. Rev. E 51, 1047 (1995)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park, Meesoon Ha, and In-mook Kim
  TITLE	Exact solutions of a restricted ballistic deposition model on a one-dimensional staircase
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 51, 1047 (1995)
  ABSTRACT

  
  

  

• Title	:	Dynamic scaling behavior of an interacting monomer-dimer model
  Journal	:	Phys. Rev. E 52, 5664 (1995)

  
  

  논문

  NUMBER
  AUTHOR	Heungwon Park, Mann Ho Kim, and Hyunggyu Park
  TITLE	Dynamic scaling behavior of an interacting monomer-dimer model
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 52, 5664 (1995)
  ABSTRACT

  
  

  

• Title	:	Critical behavior of an absorbing phase transition in an interacting monomer-dimer model
  Journal	:	Physica A 221, 97 (1995)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Heungwon Park
  TITLE	Critical behavior of an absorbing phase transition in an interacting monomer-dimer model
  ARCHIVE
  FILE
  JOURNAL	Physica A 221, 97 (1995)
  ABSTRACT

  
  

  

• Title	:	Reentrant phase diagram of branching annihilating random walks with one and two offsp
  Journal	:	Phys. Rev. E 52, 5955 (1995)

  
  

  논문

  NUMBER
  AUTHOR	Sungchul Kwon and Hyunggyu Park
  TITLE	Reentrant phase diagram of branching annihilating random walks with one and two offsp
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. E 52, 5955 (1995)
  ABSTRACT

  
  

  

• Title	:	Three-state Potts model on a triangular lattice
  Journal	:	Phys. Rev. B 49, 12881 (1994)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park
  TITLE	Three-state Potts model on a triangular lattice
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. B 49, 12881 (1994)
  ABSTRACT

  
  

  

• Title	:	Critical behavior of an interacting monomer-dimer model
  Journal	:	Phys. Rev. Lett. 73, 2579 (1994)

  
  

  논문

  NUMBER
  AUTHOR	Mann Ho Kim and Hyunggyu Park
  TITLE	Critical behavior of an interacting monomer-dimer model
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 73, 2579 (1994)
  ABSTRACT

  
  

  

• Title	:	Excluded volume effect in heterogeneous catalysis: reactions between ‘dollars’ and ‘dimes’
  Journal	:	J. Phys. A 26, 2071 (1993)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park, Joachim Koeler, In-mook Kim, Daniel ben-Avraham,and Sidney Redner
  TITLE	Excluded volume effect in heterogeneous catalysis: reactions between ‘dollars’ and ‘dimes’
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 26, 2071 (1993)
  ABSTRACT

  
  

  

• Title	:	Critical behavior of an interacting surface reaction model
  Journal	:	J. Phys. A 26, 4197 (1993)

  
  

  논문

  NUMBER
  AUTHOR	Jun Zhuo, Sidney Redner, and Hyunggyu Park
  TITLE	Critical behavior of an interacting surface reaction model
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 26, 4197 (1993)
  ABSTRACT

  
  

  

• Title	:	Critical behavior of surface-reaction models
  Journal	:	J. Korean Phys. Soc. 26, S345 (1993)

  
  

  논문

  NUMBER
  AUTHOR	Mann Ho Kim and Hyunggyu Park
  TITLE	Critical behavior of surface-reaction models
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 26, S345 (1993)
  ABSTRACT

  
  

  

• Title	:	The antiferromagnetic three-state Potts model on a triangular lattice
  Journal	:	J. Korean Phys. Soc. 26, S399 (1993)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Tong Chull Chey
  TITLE	The antiferromagnetic three-state Potts model on a triangular lattice
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 26, S399 (1993)
  ABSTRACT

  
  

  

• Title	:	Dynamic scaling theory of A + B → surface reaction
  Journal	:	J. Korean Phys. Soc. 26, S406 (1993)

  
  

  논문

  NUMBER
  AUTHOR	In-mook Kim, Hyunjoo Kim, and Hyunggyu Park
  TITLE	Dynamic scaling theory of A + B → surface reaction
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 26, S406 (1993)
  ABSTRACT

  
  

  

• Title	:	Phase diagram of a random tiling quasicrystal
  Journal	:	J. Stat. Phys. 66, 1 (1992)

  
  

  논문

  NUMBER
  AUTHOR	Weixiong Lee, Hyunggyu Park, Michael Widom
  TITLE	Phase diagram of a random tiling quasicrystal
  ARCHIVE
  FILE
  JOURNAL	J. Stat. Phys. 66, 1 (1992)
  ABSTRACT

  
  

  

• Title	:	Triviality of the critical exponents of directed self-avoiding walks on Sierpinsky carpets
  Journal	:	J. Phys. A 25, L453 (1992)

  
  

  논문

  NUMBER
  AUTHOR	Mann Ho Kim, Jysoo Lee, Hyunggyu Park, and In-mook Kim
  TITLE	Triviality of the critical exponents of directed self-avoiding walks on Sierpinsky carpets
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 25, L453 (1992)
  ABSTRACT

  
  

  

• Title	:	Logarithmic singularity in the surface free energy near commensurate-incommensurate transitions
  Journal	:	J. Phys. A 24, 257 (1991)

  
  

  논문

  NUMBER
  AUTHOR	Weixiong Lee and Hyunggyu Park
  TITLE	Logarithmic singularity in the surface free energy near commensurate-incommensurate transitions
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 24, 257 (1991)
  ABSTRACT

  
  

  

• Title	:	Interface growth with competing surface currents
  Journal	:	J. Phys. A 24, L1391 (1991)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park, Astro Provata, and Sidney Redner
  TITLE	Interface growth with competing surface currents
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 24, L1391 (1991)
  ABSTRACT

  
  

  

• Title	:	Finite-size-scaling amplitudes of the incommensurate phase
  Journal	:	Phys. Rev. Lett. 64, 1076 (1990)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Michael Widom
  TITLE	Finite-size-scaling amplitudes of the incommensurate phase
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 64, 1076 (1990)
  ABSTRACT

  
  

  

• Title	:	Universal finite-size-scaling amplitudes on a torus for the triangular Ising lattice gas
  Journal	:	J. Phys. A 23, 1789 (1990)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park
  TITLE	Universal finite-size-scaling amplitudes on a torus for the triangular Ising lattice gas
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 23, 1789 (1990)
  ABSTRACT

  
  

  

• Title	:	Finite-size-scaling amplitudes in a random tiling model
  Journal	:	J. Phys. A 23, L573 (1990)

  
  

  논문

  NUMBER
  AUTHOR	Weixiong Lee, Hyunggyu Park, and Michael Widom
  TITLE	Finite-size-scaling amplitudes in a random tiling model
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 23, L573 (1990)
  ABSTRACT

  
  

  

• Title	:	Conformal invariance in incommensurate phases
  Journal	:	J. Stat. Phys. 61, 51 (1990)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Michael Widom
  TITLE	Conformal invariance in incommensurate phases
  ARCHIVE
  FILE
  JOURNAL	J. Stat. Phys. 61, 51 (1990)
  ABSTRACT

  
  

  

• Title	:	Universal finite-size-scaling amplitudes of interfacial free energies in Monte Carlo simulations
  Journal	:	J. Phys. A 22, 3663 (1989)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Marcel den Nijs
  TITLE	Universal finite-size-scaling amplitudes of interfacial free energies in Monte Carlo simulations
  ARCHIVE
  FILE
  JOURNAL	J. Phys. A 22, 3663 (1989)
  ABSTRACT

  
  

  

• Title	:	Exact results on the antiferromagnetic three state Potts model
  Journal	:	Phys. Rev. Lett. 63, 1193 (1989)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Michael Widom
  TITLE	Exact results on the antiferromagnetic three state Potts model
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. Lett. 63, 1193 (1989)
  ABSTRACT

  
  

  

• Title	:	Universal finite-size-scaling amplitudes of the Potts model on a torus
  Journal	:	Phys. Rev. B 38, 565 (1988)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Marcel den Nijs
  TITLE	Universal finite-size-scaling amplitudes of the Potts model on a torus
  ARCHIVE
  FILE
  JOURNAL	Phys. Rev. B 38, 565 (1988)
  ABSTRACT

  
  

  

• Title	:	Anisotropic honeycomb domain wall networks in uniaxial systems
  Journal	:	Ann. Phys. 172, 419 (1986)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park, Eberhard K. Riedel, and Marcel den Nijs
  TITLE	Anisotropic honeycomb domain wall networks in uniaxial systems
  ARCHIVE
  FILE
  JOURNAL	Ann. Phys. 172, 419 (1986)
  ABSTRACT

  
  

  

• Title	:	Large q expansion of the Potts model susceptibility and magnetization in two and three dimensions
  Journal	:	J. Korean Phys. Soc. 15, 55 (1982)

  
  

  논문

  NUMBER
  AUTHOR	Hyunggyu Park and Doochul Kim
  TITLE	Large q expansion of the Potts model susceptibility and magnetization in two and three dimensions
  ARCHIVE
  FILE
  JOURNAL	J. Korean Phys. Soc. 15, 55 (1982)
  ABSTRACT