Physical review. E最新文献_第2页

Diffusion of fast and slow excitons with an exchange in quasi-two-dimensional systems. 准二维系统中快慢激子的交换扩散。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054139

Oluwafemi P Adejumobi, Vladimir N Mantsevich, Vladimir V Palyulin

{"title":"Diffusion of fast and slow excitons with an exchange in quasi-two-dimensional systems.","authors":"Oluwafemi P Adejumobi, Vladimir N Mantsevich, Vladimir V Palyulin","doi":"10.1103/PhysRevE.110.054139","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054139","url":null,"abstract":"By means of analytical calculations and numerical simulations, we study the diffusion properties in quasi-two-dimensional structures with two exciton subsystems with an exchange between them. The experimental realization is possible in systems where fast and slow exciton subsystems appear. For substantially different diffusion coefficients of the species, the negative diffusion can be observed if one measures the transport properties of only a single subsystem, just as was obtained in experimental studies for quasi-two-dimensional semiconductor systems. The initial transition from a fast subsystem to a slow one results in a delayed release of fast excitons in the area close to the original excitation spot. Hence, the signal from the fast excitons alone includes the delayed replenishment from the transition of slow quasiparticles. This is seen as the narrowing of the exciton density profile or decrease of mean-squared displacement which is then interpreted as a negative diffusion. We show that the analytical theory matches the available experimental data for negative diffusion quite well. The average diffusion coefficients for the combined population are analytically expressed through the diffusion coefficients of fast and slow excitons. Simple analytical expressions for effective diffusion coefficients obtained in limiting cases are of interest both for theoretical and experimental analysis of not only the exciton transport, but also for a variety of systems, where fast and slow moving subsystems are present.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054139"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Localized spatiotemporal dynamics in active fluids. 活性流体中的局部时空动力学。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054409

Luca Barberi, Karsten Kruse

引用次数: 0

Metaplasticity and memory in multilevel recurrent feed-forward networks. 多层次循环前馈网络中的元可塑性和记忆。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054304

Gianmarco Zanardi, Paolo Bettotti, Jules Morand, Lorenzo Pavesi, Luca Tubiana

{"title":"Metaplasticity and memory in multilevel recurrent feed-forward networks.","authors":"Gianmarco Zanardi, Paolo Bettotti, Jules Morand, Lorenzo Pavesi, Luca Tubiana","doi":"10.1103/PhysRevE.110.054304","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054304","url":null,"abstract":"Network systems can exhibit memory effects in which the interactions between different pairs of nodes adapt in time, leading to the emergence of preferred connections, patterns, and subnetworks. To a first approximation, this memory can be modeled through a \"plastic\" Hebbian or homophily mechanism, in which edges get reinforced proportionally to the amount of information flowing through them. However, recent studies on glia-neuron networks have highlighted how memory can evolve due to more complex dynamics, including multilevel network structures and \"metaplastic\" effects that modulate reinforcement. Inspired by those systems, here we develop a simple and general model for the dynamics of an adaptive network with an additional metaplastic mechanism that varies the rate of Hebbian strengthening of its edge connections. The metaplastic term acts on a second network level in which edges are grouped together, simulating local, longer timescale effects. Specifically, we consider a biased random walk on a cyclic feed-forward network. The random walk chooses its steps according to the weights of the network edges. The weights evolve through a Hebbian mechanism modulated by a metaplastic reinforcement, biasing the walker to prefer edges that have been already explored. We study the dynamical emergence (memorization) of preferred paths and their retrieval and identify three regimes: one dominated by the Hebbian term, one in which the metareinforcement drives memory formation, and a balanced one. We show that, in the latter two regimes, metareinforcement allows the retrieval of a previously stored path even after the weights have been reset to zero to erase Hebbian memory.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054304"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evidence that the de Almeida-Thouless transition disappears below six dimensions. 德阿尔梅达-索利斯跃迁在六维以下消失的证据。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054131

Bharadwaj Vedula, M A Moore, Auditya Sharma

引用次数: 0

Emergence of self-organized criticality and phase transition in the Olami-Feder-Christensen model with a single defect. 具有单一缺陷的olami - federd - christensen模型中出现了自组织临界和相变。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054129

Tetsuto Otani, Nobuki Kame

引用次数: 0

Exact time-dependent thermodynamic relations for a Brownian particle moving in a ratchet potential coupled with quadratically decreasing temperature. 在棘轮势中运动的布朗粒子与温度二次下降耦合的精确时相关热力学关系。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054105

Mesfin Asfaw Taye

{"title":"Exact time-dependent thermodynamic relations for a Brownian particle moving in a ratchet potential coupled with quadratically decreasing temperature.","authors":"Mesfin Asfaw Taye","doi":"10.1103/PhysRevE.110.054105","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054105","url":null,"abstract":"The thermodynamic relations for a Brownian particle moving in a discrete ratchet potential coupled with quadratically decreasing temperature are explored as a function of time. We show that this thermal arrangement leads to a higher velocity (lower efficiency) compared to a Brownian particle operating between hot and cold baths, and a heat bath where the temperature linearly decreases along with the reaction coordinate. The results obtained in this study indicate that if the goal is to design a fast-moving motor, the quadratic thermal arrangement is more advantageous than the other two thermal arrangements. In contrast, the entropy, entropy production rate, and entropy extraction rate are significantly larger in the case of a quadratically decreasing temperature compared to the linearly decreasing temperature case and piecewise constant temperature case. Furthermore, the thermodynamic features of a system consisting of several Brownian ratchets arranged in a complex network are explored. The theoretical findings exhibit that as the network size increases, the entropy, entropy production, and entropy extraction of the system also increase, showing that these thermodynamic quantities exhibit extensive property. As a result, as the number of lattice sizes increases, thermodynamic relations such as entropy, entropy production, and entropy extraction also step up, confirming that these complex networks cannot be reduced to a corresponding one-dimensional lattice. However, in the long time limit, thermodynamic relations such as velocity, entropy production rate, and entropy extraction rate become independent of the network size. These results are also confirmed via a continuum Fokker-Planck model for the overdamped case.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054105"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Adversarial training and attribution methods enable evaluation of robustness and interpretability of deep learning models for image classification. 通过对抗性训练和归因方法，可以评估用于图像分类的深度学习模型的鲁棒性和可解释性。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054310

Flávio A O Santos, Cleber Zanchettin, Weihua Lei, Luís A Nunes Amaral

{"title":"Adversarial training and attribution methods enable evaluation of robustness and interpretability of deep learning models for image classification.","authors":"Flávio A O Santos, Cleber Zanchettin, Weihua Lei, Luís A Nunes Amaral","doi":"10.1103/PhysRevE.110.054310","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054310","url":null,"abstract":"Deep learning models have achieved high performance in a wide range of applications. Recently, however, there have been increasing concerns about the fragility of many of those models to adversarial approaches and out-of-distribution inputs. A way to investigate and potentially address model fragility is to develop the ability to provide interpretability to model predictions. To this end, input attribution approaches such as Grad-CAM and integrated gradients have been introduced to address model interpretability. Here, we combine adversarial and input attribution approaches in order to achieve two goals. The first is to investigate the impact of adversarial approaches on input attribution. The second is to benchmark competing input attribution approaches. In the context of the image classification task, we find that models trained with adversarial approaches yield dramatically different input attribution matrices from those obtained using standard techniques for all considered input attribution approaches. Additionally, by evaluating the signal-(typical input attribution of the foreground)-to-noise (typical input attribution of the background) ratio and correlating it to model confidence, we are able to identify the most reliable input attribution approaches and demonstrate that adversarial training does increase prediction robustness. Our approach can be easily extended to contexts other than the image classification task and enables users to increase their confidence in the reliability of deep learning models.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054310"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Irreversible dynamics of a continuum driven by active matter. 活性物质驱动的连续体的不可逆动力学。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054114

John C Neu, Stephen W Teitsworth

引用次数: 0

Scaling behavior of cross-entropy loss in the identification of percolation phase transitions. 交叉熵损失在渗流相变识别中的标度行为。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054133

Huiyao Li, Yu Zhao, Bo Yang

{"title":"Scaling behavior of cross-entropy loss in the identification of percolation phase transitions.","authors":"Huiyao Li, Yu Zhao, Bo Yang","doi":"10.1103/PhysRevE.110.054133","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054133","url":null,"abstract":"The cross-entropy loss function is widely used in machine learning to measure the performance of a classification model. Interestingly, our study find that this function has scaling behavior when deep neural networks are used to investigate percolation models. Specifically, we use convolutional neural networks with different pooling methods to study the site percolation on square lattices under two labeling methods (labeling based on spanning cluster and the exact solution of the critical point). Subsequently, graph convolutional neural networks (GCNs) with different pooling methods are utilized to do the same kind of experiment. Finally, the GCN with different pooling methods is used to study the percolation phase transitions on the Erdős-Rényi (ER) networks under labeling based on the critical point. The reliability of the classifiers is detected by the values of the critical point p_{c} and critical exponent ν which are obtained by the scaling behaviors of the percolation probability. The results demonstrate that the scaling exponent of cross-entropy ψ/ν depends on the labeling and pooling methods. Labeling based on critical points, which is equivalent to labeling based on spanning clusters in infinite systems, can be used to investigate the critical behaviors in finite systems. SAGPooling-Mean is an effective pooling method to study the scaling behavior of cross-entropy loss on two-dimensional square lattices and ER networks.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054133"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of external potential on the energy transport in harmonically driven segmented Frenkel-Kontorova lattices. 外电位对谐波驱动分段Frenkel-Kontorova晶格中能量输运的影响。

IF 2.4 3区物理与天体物理

Physical review. E Pub Date : 2024-11-01 DOI: 10.1103/PhysRevE.110.054115

M Romero-Bastida

{"title":"Effect of external potential on the energy transport in harmonically driven segmented Frenkel-Kontorova lattices.","authors":"M Romero-Bastida","doi":"10.1103/PhysRevE.110.054115","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.054115","url":null,"abstract":"Thermal resonance, that is, the heat flux obtained by means of a periodic external driving, offers the possibility of controlling heat flux in nanoscale devices suitable for power generation, cooling, and thermoelectrics, among others. In this work we study the effect of the onsite potential period on the thermal resonance phenomenon present in a one-dimensional system composed of two dissimilar Frenkel-Kontorova lattices connected by a time-modulated coupling and in contact with two heat reservoirs operating at different temperature by means of molecular dynamics simulations. When the periods of the onsite potential on both sides of the system are equal, the maximum resonance is obtained for the lowest considered value of the period. For highly structurally asymmetric lattices, the heat flux toward the cold reservoir is maximized, and asymmetric periods of the onsite potential afford an extra way to control the magnitude of the heat fluxes in each side of the system. Our results highlight the importance of the substrate structure on thermal resonance and could inspire further developments in designing thermal devices.","PeriodicalId":20085,"journal":{"name":"Physical review. E","volume":"110 5-1","pages":"054115"},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142847212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0