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A novel three-phase expansion algorithm for uncovering communities in social networks using local influence and similarity in embedding space

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Decision Analytics Journal 2024年 11卷

作者： Adraoui, Meriem Akachar, Elyazid Bougteb, Yahya Ouhbi, Brahim Frikh, Bouchra Retbi, Asmaa Bennani, Samir Center of Urban Systems (CUS) Mohammed VI Polytechnic University (UM6P) Benguerir Morocco Department of Computer Science Faculty of Sciences Moulay Ismail University Meknes Morocco LM2I Laboratory National Higher School of Arts and Crafts (ENSAM) Moulay Ismaïl University Meknes Morocco LIASSE Laboratory Computer Science Department National School of Applied Sciences (ENSA) Sidi Mohamed Ben Abdellah University Fez Morocco RIME TEAM-Networking Modeling and e-Learning Team- LRIE Laboratory- Research in Computer Science and Education Laboratory- Mohammadia School of Engineers (EMI). Mohammed V University in Rabat Morocco

Community detection can help uncover and understand complex networks’ underlying patterns and structures. It involves identifying cohesive groups with similar entities while being separated from other groups. Social networks are a prime example of an area where community detection is particularly relevant, as it can provide insight into the behaviors of individuals. Several community detection methods have been proposed, each addressing the problem from different perspectives. However, the rise of vast and intricate networks from diverse domains has necessitated the development of community detection methods that can effectively handle large-scale graphs. This study introduces a novel three-phase expansion algorithm for community discovery based on nodes’ local information and similarity in embedding space. The proposed model consists of three steps. In the first stage, we generate an embedding space in which nodes are represented as vectors, and we extract nodes that greatly influence others and have an extraordinary ability to create communities using degree centrality measures. Then, based on cosine similarity in the embedding space, we group the most similar nodes to the influential ones in the same community and create an initial community structure. In the last phase, we extract the weak communities from the initial community structure generated in the second phase and merge them with the strong ones. We conduct extensive experiments on both real-world and synthetic networks to demonstrate the effectiveness of our proposal. The experimental results show that the proposed algorithm performs better than other widely used algorithms and is highly reliable and efficient in large-scale graphs. © 2024 The Author(s)

关键词： Centrality measures Community detection Cosine similarity Embedding space Influential nodes Social networks

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ROTA-BAXTER OPERATORS, DIFFERENTIAL OPERATORS, PRE- AND NOVIKOV STRUCTURES ON GROUPS AND LIE ALGEBRAS

arXiv

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arXiv 2024年

作者： Gao, Xing Guo, Li Han, Zongjian Zhang, Yi School of Mathematics and Statistics Lanzhou University Lanzhou730000 China Gansu Provincial Research Center for Basic Disciplines of Mathematics and Statistics Lanzhou730070 China Department of Mathematics and Computer Science Rutgers University NewarkNJ07102 United States School of Mathematical Sciences Tonji University Shanghai200092 China School of Mathematics and Statistics Center for Applied Mathematics of Jiangsu Province Jiangsu International Joint Laboratory on System Modeling and Data Analysis NUIST Jiangsu Nanjing210044 China

Rota-Baxter operators on various structures have found important applications in diverse areas, from renormalization of quantum field theory to Yang-Baxter equations. Relative Rota-Baxter operators on Lie algebras are closely related to pre-Lie algebras and post-Lie algebras. Some of their group counterparts have been introduced to study post-groups, skew left braces and set-theoretic solutions of Yang-Baxter equations, but searching suitable notions of relative Rota-Baxter operators on groups with weight zero and pre-groups has been challenging and has been the focus of recent studies, by provisionally imposing an abelian condition. Arising from the works of Balinsky-Novikov and Gelfand-Dorfman, Novikov algebras and their constructions from differential commutative algebras have led to broad applications. Finding their suitable counterparts for groups and Lie algebras has also attracted quite much recent attention. This paper uses one-sided-inverse pairs of maps to give a perturbative approach to a general notion of relative Rota-Baxter operators and differential operators on a group and a Lie algebra with limit-weight. With the extra condition of limit-abelianess on the group or Lie algebra, we give an interpretation of relative Rota-Baxter and differential operators with weight zero. These operators motivate us to define pre-groups and Novikov groups respectively as the induced structures. The tangent maps of these operators are shown to give Rota-Baxter and differential operators with weight zero on Lie algebras. The tangent spaces of the pre-Lie and Novikov Lie groups are pre-Lie algebras and Novikov Lie algebras, fulfilling the expected property. Furthermore, limit-weight relative Rota-Baxter operators on groups give rise to skew left braces and then set-theoretic solutions of the Yang-Baxter *** Codes 22E60, 17B38, 17B40, 16W99, 45N05 Copyright © 2024, The Authors. All rights reserved.

关键词： Lie groups

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Splitting Schemes for Coupled Differential Equations: Block Schur-Based Approaches and Partial Jacobi Approximation

arXiv

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arXiv 2022年

作者： Nuca, Roberto Storvik, Erlend Radu, Florin A. Icardi, Matteo CEMSE King Abdullah University of Science and Technology Thuwal Saudi Arabia Center for Modeling of Coupled Subsurface Dynamics Department of Mathematics University of Bergen Allégaten 44 Bergen5007 Norway Department of Computer Science Electrical Engineering and Mathematical Sciences Western Norway University of Applied Sciences Svanehaugvegen 1 Førde6812 Norway School of Mathematical Sciences University of Nottingham NottinghamNG7 2RD United Kingdom

Coupled multi-physics problems are encountered in countless applications and pose significant numerical challenges. In a broad sense, one can categorise the numerical solution strategies for coupled problems into two classes: monolithic approaches and sequential (also known as split, decoupled, partitioned or segregated) approaches. The monolithic approaches treat the entire problem as one, whereas the sequential approaches are iterative decoupling techniques where the different sub-problems are treated separately. Although the monolithic approaches often offer the most robust solution strategies, they tend to require ad-hoc preconditioners and numerical implementations. Sequential methods, on the other hand, offer the possibility to add and remove equations from the model flexibly and rely on existing black-box solvers for each specific equation. Furthermore, when problems are non-linear, inner iterations need to be performed even in monolithic solvers, making the sequential approaches an even more viable alternative. The cost of running inner iterations to recover the multi-physics coupling could, however, easily become prohibitive. Moreover, the sequential approaches might not converge at all. In this work, we present a general formulation of splitting schemes for continuous operators with arbitrary implicit/explicit splitting, like in standard iterative methods for linear systems. By introducing a generic relaxation operator, we find the conditions for the convergence of the iterative schemes. We show how the relaxation operator can be thought of as a preconditioner and constructed based on an approximate Schur complement. We propose a Schur-based Partial Jacobi relaxation operator to stabilise the coupling and show its effectiveness. Although we mainly focus on scalar-scalar linear problems, most results are easily extended to non-linear and higher-dimensional problems. The schemes presented are not explicitly dependent on any particular discretisation methodol

关键词： Iterative methods

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On the undecidability of the panopticon detection problem

arXiv

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arXiv 2021年

作者： Liagkou, V. Nastou, P.E. Spirakis, P. Stamatiou, Y.C. Computer Technology Institute and Press - "Diophantus" University of Patras Campus 26504 Greece Department of Computer Science University of Liverpool UK and Computer Engineering and Informatics Department University of Patras 26504 Greece Department of Business Administration University of Patras 26504 Greece University of Ioannina Department of Informatics and Telecommunications Koatakioi Arta47100 Greece Department of Mathematics University of the Aegean Applied Mathematics and Mathematical Modeling Laboratory Samos Greece

The Panopticon (which means "watcher of everything") is a well-known structure of continuous surveillance and discipline proposed by Bentham in 1785. This device was, later, used by Foucault and other philosophers as a paradigm and metaphor for the study of constitutional power and knowledge as well as a model of individuals’ deprivation of freedom. Nowadays, technological achievements have given rise to new, non-physical (unlike prisons), means of constant surveillance that transcend physical boundaries. This, combined with the confession of some governmental institutions that they actually collaborate with these Internet giants to collect or deduce information about people, creates a worrisome situation of several co-existing Panopticons that can act separately or in close collaboration. Thus, they can only be detected and identified through the expense of (perhaps considerable) effort. In this paper we provide a theoretical framework for studying the detectability status of Panopticons that fall under two theoretical, but not unrealistic, definitions. We show, using Oracle Turing Machines, that detecting modern day, ICT-based, Panopticons is an undecidable problem. Furthermore, we show that for each sufficiently expressive formal system, we can effectively construct a Turing Machine for which it is impossible to prove, within the formal system, either that it is a Panopticon or it is not a Panopticon. © 2021, CC BY.

关键词： Turing machines

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An interpolating family of size distributions

arXiv

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arXiv 2020年

作者： Sinner, Corinne Dominicy, Yves Trufin, Julien Waterschoot, Wout Weber, Patrick Ley, Christophe Belgium Spuerkeess Modeling and Analytics Service Credit Process Management Luxembourg Department of Applied Mathematics Computer Science and Statistics Ghent University Belgium

Power laws and power laws with exponential cut-off are two distinct families of size distributions. In the present paper, we propose a unified treatment of both families by building a family of distributions that interpolates between them, hence the name Interpolating Family (IF) of distributions. Our original construction, which relies on techniques from statistical physics, provides a connection for hitherto unrelated distributions like the Pareto and Weibull distributions, and sheds new light on them. The IF also contains several distributions that are neither of power law nor of power law with exponential cut-off type. We calculate quantile-based properties, moments and modes for the IF. This allows us to review known properties of famous size distributions and to provide in a single sweep these characteristics for various less known (and new) special cases of our Interpolating Family. Copyright © 2020, The Authors. All rights reserved.

关键词： Pareto principle

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Local Thermal Non-Equilibrium Models in Porous Media: A Comparative Study of Conduction Effects

arXiv

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arXiv 2025年

作者： Kostelecky, Anna Mareike Stefansson, Ivar Bringedal, Carina Ghosh, Tufan Dahle, Helge K. Helmig, Rainer Institute for Modelling Hydraulic and Environmental Systems Univeristy of Stuttgart Stuttgart Germany Department of Mathematics University of Bergen Bergen Norway Center for Modeling of Coupled Subsurface Dynamics Department of Mathematics University of Bergen Bergen Norway Department of Computer science Electrical engineering and Mathematical sciences Western Norway University of Applied Sciences Bergen Norway

Instantaneous heat transfer between different phases is a common assumption for modeling heat transfer in porous media, known as Local Thermal Equilibrium (LTE). This assumption may not hold in certain technical and environmental applications, especially in systems with large temperature gradients, large differences in thermal properties, or high velocities. Local Thermal Non-Equilibrium (LTNE) models aim to describe heat transfer processes when the LTE assumption may fail. In this work, we compare three continuum-scale models from the pore to the representative elementary volume (REV) scale. Specifically, dual-network and REV-scale models are evaluated against a pore-resolved model, which we perceive as a reference in the absence of experimental results. Different effective models are used to obtain upscaled properties on the REV scale and to compare resulting temperature profiles. The systems investigated are fully saturated, consisting of one fluid and one solid phase. This study focuses on purely conductive systems without significant differences in thermal properties. Results show that LTE holds then for low interfacial resistances. However, for large interfacial resistances, solid and fluid temperatures differ. The REV-scale model with effective parameters obtained by homogenization leads to similar results as the pore-resolved model, whereas the dual-network model shows greater deviation due to its fixed spatial resolution. Among the evaluated effective parameter formulations for the REV-scale model, only the homogenization-based approach captures the LTNE behavior, as it incorporates the interfacial heat transfer coefficient. Convection is relevant for most practical applications, and its impact will be addressed in a follow-up article. © 2025, CC BY.

关键词： Electric heating

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Analyzing the dynamics of COVID-19 transmission in select regions of the Philippines: A modeling approach to assess the impact of various tiers of community quarantines

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Heliyon 2024年第21期10卷 e39330页

作者： Mata, May Anne E. Escosio, Rey Audie S. Rosero, El Veena Grace A. Viernes, Jhunas Paul T. Anonuevo, Loreniel E. Hernandez, Bryan S. Addawe, Joel M. Addawe, Rizavel C. Pilar-Arceo, Carlene P.C. Mendoza, Victoria May P. de los Reyes, Aurelio A. Mindanao Center for Disease Watch and Analytics (DiWA) University of the Philippines Mindanao Tugbok District Davao City 8000 Philippines Interdisciplinary Applied Modeling (IAM) Laboratory University of the Philippines Mindanao Tugbok District Davao City 8000 Philippines Department of Mathematics Physics and Computer Science University of the Philippines Mindanao Tugbok District Davao City 8000 Philippines University of the Philippines Resilience Institute University of the Philippines Diliman Quezon City 1101 Philippines Institute of Mathematics University of the Philippines Diliman Quezon City 1101 Philippines Faculdade de Ciências Universidade de Lisboa Lisbon 1749-016 Portugal BioISI—Biosystems & Integrative Sciences Institute Faculdade de Ciências Universidade de Lisboa Lisbon 1749-016 Portugal Department of Mathematics and Computer Science University of the Philippines Baguio Baguio City 2600 Philippines Mapúa Malayan Colleges Mindanao Davao City 8000 Philippines Mathematics Department Caraga State University Ampayon Butuan City 8600 Philippines

The COVID-19 pandemic has significantly impacted communities worldwide, and effective management strategies are critical to reduce transmission rates and minimize the impact of the disease. In this study, we modeled and analyzed the COVID-19 transmission dynamics and derived relevant epidemiological values for three regions of the Philippines, namely, the National Capital Region (NCR), Davao City, and Baguio City, under different community quarantine implementations. The unique features and differences of these regions-of-interest were accounted for in simulating the disease spread and in estimating key epidemiological parameters fitted to the reported COVID-19 cases. Results support the robustness of the model formulated and provides insights into the effect of the government's implemented intervention protocols. With a forecasting feature, this modeling framework is beneficial for science-based decision support, policy making, and assessment for recent and future pandemics wherever regions-of-interest. © 2024 The Author(s)

关键词： Community quarantine Compartmental model Coronavirus Population factor SEIR Time-varying reproduction number

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Hopping-Transport Mechanism for Reconfigurable Logic in Disordered Dopant Networks

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Physical Review applied 2022年第6期17卷 064025-064025页

作者： Henri Tertilt Jesse Bakker Marlon Becker Bram de Wilde Indrek Klanberg Bernard J. Geurts Wilfred G. van der Wiel Andreas Heuer Peter A. Bobbert Institut für physikalische Chemie Westfälische Wilhelms-Universität Münster Münster Germany NanoElectronics Group University of Twente Enschede Netherlands Multiscale Modeling and Simulation Group Faculty of Electrical Engineering Mathematics and Computer Science MESA+ Institute for Nanotechnology and Center for Brain-Inspired Nano Systems (BRAINS) University of Twente Enschede Netherlands Center for Computational Energy Research (CCER) Eindhoven University of Technology Netherlands Fachbereich Physik Westfälische Wilhelms-Universität Münster Münster Germany Department of Applied Physics Eindhoven University of Technology Netherlands

We present an atomic-scale mechanism based on variable-range hopping of interacting charges enabling reconfigurable logic in dopant network processing units. Kinetic Monte Carlo simulations of the hopping process show temperature-dependent current-voltage characteristics and artificially evolved basic Boolean logic gates in very good agreement with experiment. The simulations provide unique insights into the local electrostatic potential and current flow in the dopant network, showing subtle changes induced by control voltages that set the conditions for the logic operation. These insights will be crucial in the systematic further development of this burgeoning technology for unconventional computing. The establishment of the principles underlying the logic functionality of these devices encourages the exploration and utilization of the same principles in other materials and device geometries.

关键词： Doping effects Hopping transport Neuromorphic computing Devices for digital logic, storage & processing Disordered systems Doped semiconductors Genetic algorithm Monte Carlo methods

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Parallel Computing optimization of Two- Dimensional Mathematical modeling of Contaminant Migration in Catalytic Porous Media

Parallel Computing optimization of Two- Dimensional Mathemat...

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International Conference on Advanced computer Information Technologies (ACIT)

作者： Anatoliy Vlasyuk Viktor Zhukovskyy Nataliia Zhukovska Serhii Shatnyi Department of Economics Mathematical Modeling and Information Technologies The National University of Ostroh Academy Ostroh Ukraine Department of Computer Science and Applied Mathematics The National University of Water and Environmental Engineering Rivne Ukraine Department of Computer Engineering The National University of Water and Environmental Engineering Rivne Ukraine

ISBN: (数字)9781728167602

ISBN: (纸本)9781728167619

The mathematical model of a two-dimensional nonlinear case of contaminant migration to the filter traps in catalytic porous media in isothermal conditions is presented. The mathematical model takes into account the micro and the meso/macro scale factors of the mass transfer process. The numerical solution of the respective boundary value problem was obtained by the method of finite differences. Parallel computing optimization was conducted for numerical sweep method as well as for Orleans Grain management. The appropriate algorithmic complexity of the parallel block sweep method was shown. The general architecture of a new application was described. The resulted software was implemented in Microsoft Azure cloud computing platform. After a series of numerical experiments, the optimization performance results (speedup ratio and parallel efficiency) of a created solution were collected and discussed.

关键词： Mathematical model Soil Optimization Computational modeling Skeleton Filtration Software

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Surface localization of plasmons in three dimensions and convexity

arXiv

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arXiv 2020年

作者： Ando, Kazunori Kang, Hyeonbae Miyanishi, Yoshihisa Nakazawa, Takashi Department of Electrical and Electronic Engineering and Computer Science Ehime University Ehime790-8577 Japan Department of Mathematics Institute of Applied Mathematics Inha University Incheon22212 Korea Republic of Center for Mathematical Modeling and Data Science Osaka University Osaka560-8531 Japan

The Neumann–Poincaré operator defined on a smooth surface has a sequence of eigenvalues converging to zero, and the single layer potentials of the corresponding eigenfunctions, called plasmons, decay to zero, i.e., are localized on the surface, as the index of the sequence j tends to infinity. We investigate quantitatively the surface localization of the plasmons in three dimensions. The results are threefold. We first prove that on smooth bounded domains of general shape the sequence of plasmons converges to zero off the boundary surface almost surely at the rate of j−1/2. We then prove that if the domain is strictly convex, then the convergence rate becomes j−∞, namely, it is faster than j−N for any integer N. As a consequence, we prove that cloaking by anomalous localized resonance does not occur on three-dimensional strictly convex smooth domains. We then look into the surface localization of the plasmons on the Clifford torus by numerical computations. The Clifford torus is taken as an example of non-convex surfaces. The computational results show that the torus exhibits the spectral property completely different from strictly convex domains. In particular, they suggest that there is a subsequence of plasmons on the torus which has much slower decay than other entries of the *** Codes 35J47 (primary), 35P05 (secondary). Copyright © 2020, The Authors. All rights reserved.

关键词： Plasmons

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