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International Conference on Computing, Networking and Communications (ICNC)

作者： Zilu Zhao Dirk Slock Communication Systems Department EURECOM France

ISBN: (数字)9798331520960

ISBN: (纸本)9798331520977

The Bethe Free Energy (BFE) has been found to be closely connected to various message passing algorithms. Studies have indicated that the BFE shares stationary points with message passing algorithms like Belief Propagation (BP) and Expectation Propagation (EP). Generalized Approximate Message Passing (GAMP) algorithms have demonstrated significant efficacy in signal recovery. Nevertheless, they may encounter convergence issues. EP algorithms start from a factored approximate posterior in an exponential family. They update a factor by fitting an exponential family pdf to a approximate posterior which is obtained by replacing one approximate factor by the original (prior) factor. The remaining factors form the approximate extrinsic. Hence extrinsics are obtained by marginalizing the product of all pdf factors except for the prior. A marginal posterior is then obtained by combining the extrinsic with the prior. Low complexity algorithms like GAMP in turn obtain the extrinsic from the posterior. In this paper, we explore the BFE within the context of Generalized Linear Models (GLMs). Applying a BFE based EP approach leads to the re(G)VAMP algorithm which provides asymptotically exact marginal posteriors based on asymptotically Gaussian extrinsics. It also provides equivalent Gaussian priors and hence an equivalent overall Gaussian linear model, which allows the application of large random matrix theory. We show how on the other hand how Large System Limit (LSL) based approximations in BP lead to GAMP. When derived from the BFE of the GLM, GAMP algorithms combine two asymptotic LSL simplifications which are asymptotic Gaussianity of extrinsics and large random matrix theory based asymptotic variance computations. The LSL simplifications allow to relate extrinsic messages to posterior pdfs by first-order Taylor series expansion based perturbations. We also apply LSL approximations to the variances of the various Gaussians involved, which in fact leads to a rederivation of

关键词： Hands Message passing Perturbation methods Computational modeling Fitting Estimation approximation algorithms Taylor series Convergence Context modeling

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Approximately EFX and PO Allocations for Bivalued Chores

arXiv

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arXiv 2025年

作者： Lin, Zehan Wu, Xiaowei Zhou, Shengwei IOTSC University of Macau China

We consider the computation for allocations of indivisible chores that are approximately EFX and Pareto optimal (PO). Recently, Garg et al. (2024) show the existence of 3-EFX and PO allocations for bi-valued instances, where the cost of an item to an agent is either 1 or k (where k > 1) by rounding the (fractional) earning restricted equilibrium. In this work, we improve the approximation ratio to (2 − 1/k), while preserving the Pareto optimality. Instead of rounding fractional equilibrium, our algorithm starts with the integral EF1 equilibrium for bi-valued chores, introduced by Garg et al. (AAAI 2022) and Wu et al. (EC 2023), and reallocates items until approximate EFX is achieved. We further improve our result for the case when k = 2 and devise an algorithm that computes EFX and PO allocations. Copyright © 2025, The Authors. All rights reserved.

关键词： approximation algorithms

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Comparison of Unsupervised Learning algorithms for K-Means Clustering Efficiency in IoE Sensor Detection Systems for Smart Agriculture

Comparison of Unsupervised Learning Algorithms for K-Means C...

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International Electrical Engineering Congress (iEECON)

作者： Wallop Tipwong Adisorn Sirikham Jessada Konpang Putthiphong Kirdpipat Yutana Chongjarearn Oradee Preutisrunyanont Department of Electrical and Telecommunication Engineering Rajamangala University of Technology Krungthep Bangkok Thailand Department of Electrical and Computer Engineering Faculty of Engineering Thammasat School of Engineering Thammasat University Pathum Thani Thailand Department of Robotic Engineering and Automation System Dhurakij Pundit University Bangkok Thailand

ISBN: (数字)9798331543952

ISBN: (纸本)9798331543969

This study investigates the application of clustering algorithms to data collected from color sensors providing frequency signals during the cultivation process. Continuous sampling allowed for real-time data collection, and variations in temperature and humidity were observed to influence signal reception. The dataset's large volume and varying sample sizes necessitated the evaluation of several clustering models for efficient data processing. The experiment tested K-Means, K-Means++, Mini-Batch K-Means, and Bisecting K-Means algorithms. The results reveal that the computation time for each model increased with the number of groups. Specifically, the K-Means, K-Means++, and Mini-Batch K-Means models exhibited shorter computation times, ranging from 0.02 to 0.03 seconds for two-group scenarios, while the Bisecting K-Means algorithm took significantly longer, approximately 0.10 seconds. Despite the variation in processing times, all models performed similarly in terms of clustering quality, with an average Silhouette Score of 0.82. This score indicates that the algorithms effectively separated data points into well-defined groups while maintaining high accuracy in clustering. Additionally, the analysis highlighted the importance of balancing computation time and clustering quality, particularly as the number of clusters increases. These findings suggest that while computational efficiency may vary across models, the clustering quality remains robust, providing valuable insights for data analysis in agricultural sensor networks. The study's results demonstrate that each clustering model is capable of handling large datasets with high accuracy in grouping, making them applicable to real-world agricultural data processing scenarios. In conclusion, the experiment confirms that all tested models, despite differing in computation time, successfully partitioned the data with high-quality results, offering promising applications for data analysis and optimization in agricult

关键词： Temperature sensors Analytical models Image color analysis Computational modeling Clustering algorithms approximation algorithms Data models Sensor systems Computational efficiency Optical sensors

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Locating Domination Set in Some Subclasses of B_1-Vpg Graphs and B_1-Epg Graphs

SSRN

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SSRN 2025年

作者： Yang, Yu Wang, Cai-Xia Xu, Shou-Jun Gutin, Gregory School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex Systems Lanzhou University Gansu Lanzhou730000 China Department of Computer Science Royal Holloway University of London United Kingdom School of Mathematical Sciences LPMC Nankai University China

A graph G is a B_k-VPG graph if there exists an integer k such that each vertex corresponds to an orthogonal path in the plane with at most k bends. Two vertices $u$ and v in V(G) are adjacent if and only if the corresponding paths intersect.A graph G is said to be a B_k-EPG graph if there exists an integer k such that G has a string representation on a grid where each vertex corresponds to an orthogonal path (string) with at most $k$ bends. Two vertices u and v in V(G) are adjacent if and only if the corresponding paths share at least one grid *** consider the problems of finding optimal locating dominating sets, open locating dominating sets, and identifying codes of B_{k}-VPG (resp., B_{k}-EPG) graphs. We prove that the decision problems associated with these three notions are NP-complete in grid graphs (a subclass of unit B_approximation-VPG graphs). Secondly, we give an O(k^{2})-approximation algorithm for the dominating set problem on unit B_{k}-VPG graphs, improving the previous O(k^{4})-approximation algorithm of Chakraborty et al. \cite{dsj22}. Moreover, we show that the decision problem of locating dominating set is NP-complete on a subclass of B_approximation-EPG graphs, and we also show that the minimum locating dominating set problem is APX-hard on B_approximation-EPG graphs, ruling out the possibility of a PTAS unless P=***, we give a linear-time labeling algorithm for finding optimal locating dominating sets on the cactus graphs, which are a subclass of B_approximation-EPG graphs. © 2025, The Authors. All rights reserved.

关键词： approximation algorithms

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3D Radiation Pattern Reconstruction of Millimeterwave Wireless Device with Phaseless Nearfield Measurement

3D Radiation Pattern Reconstruction of Millimeterwave Wirele...

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European Conference on Antennas and Propagation, EuCAP

作者： Myssipsa Mehraz François Gallee Shoaib Anwar Microwave department IMT Atlantique Lab STICC CNRS UMR 6285 Brest France MVG Industries Technopole Best Iroise Plouzane France

ISBN: (数字)9788831299107

ISBN: (纸本)9798350366327

This paper explores the application of the Iterative Fourier Transform (IFT) algorithm for reconstructing antenna radiation patterns using phaseless near-field measurements. A detailed comparison between two variants of the IFT algorithm is conducted to evaluate their convergence efficiency and accuracy in phase retrieval. The selected IFT variant was validated through measurements of a 96 GHz horn antenna. We studied key phaseless measurement parameters to ensure proper control over their impact on the algorithm, as well as to optimize and accelerate measurement times according to specific needs. It was demonstrated that the IFT algorithm is robust even when the defined aperture size exceeds the actual antenna size and can also be used to approximate the true antenna size by refining from a larger initial value. After algorithm validation, we applied it to an integrated antenna array within a 60 GHz Wi-Fi module to characterize its radiation in standalone mode, both with and without the enclosure, as well as when connected.

关键词： Antenna measurements Phased arrays Wireless communication Phase measurement Three-dimensional displays approximation algorithms Iterative algorithms Aperture antennas Wireless fidelity Antenna radiation patterns

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Research on edge computing capability optimization of intelligent fusion terminal in distribution area based on deep learning

Research on edge computing capability optimization of intell...

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Smart Grid and Green Energy (ICSGGE), International Conference on

作者： Chen Lu Xi Chen Hai Fan Tianhao Wu Yang Wu Haibo Liu State Grid Wuhan Electric Power Supply Company Wuhan China State Grid Wuhan Economic Development&Technological Zone (HANNAN) Electric Power Supply Company Wuhan China

ISBN: (数字)9798331542139

ISBN: (纸本)9798331542146

For the scenario of multiple edge servers and multiple smart meter devices. First, the system model is constructed, and the problem model is to minimize the weighted total cost of delay and energy consumption. Based on DQN, we integrate Actor network and Critic network into it to form a new DDPG algorithm, which adopts deterministic strategy to select actions by approximating the value function model of neural network. According to the actual problem, three elements are set for the deep reinforcement learning algorithm: state, action and reward. Finally, the calculation time of various migration strategies was recorded. The results show that compared with DQN and other algorithms, the proposed DDPG algorithm can obtain a better task migration strategy, and has a significant effect on reducing the total weighted system overhead.

关键词： Green energy Energy consumption Costs Neural networks Optimization methods approximation algorithms Smart meters Smart grids Servers Edge computing

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UAV-Aided Delay-Oriented IoT Data Collection Strategies Using a Pattern Search Framework

UAV-Aided Delay-Oriented IoT Data Collection Strategies Usin...

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IEEE Conference on Wireless Communications and Networking

作者： Kyeongsoo Kim Wooseok Cha Jihwan P. Choi Dept. of Aerospace Engineering KAIST Korea

ISBN: (数字)9798350368369

ISBN: (纸本)9798350368376

The role of unmanned aerial vehicle (UAV) technologies in the Internet of Things (IoT) data collection is attracting tremendous attention due to its operational flexibility. To guarantee reliability and network efficiency of the IoTecosystem, delay is a crucial performance metric in a IoTdata collection scenario. To reap the benefits of UAVs, this paper investigates delay-oriented IoT data collection scenarios utilizing UAVs. To achieve low-delay data transmission, non-orthogonal multiple access (NOMA), which has high spectral efficiency, is employed. Considering the queue system of IoT, we formulate a problem that jointly optimizes UAV deployment and IoT transmit power to minimize the average packet delay of IoT nodes. As a novel strategy to solve the non-convex problem, a pattern search framework that can obtain near-optimal UAV deployment and IoT transmit power is proposed. Numerical results show that the optimal deployment of UAV depends on the traffic volume of IoT nodes to minimize delay. Furthermore, our proposed pattern search framework achieves significant delay reduction up to 85% compared to other benchmark schemes, highlighting its potential in the UAV-aided IoT data collection.

关键词： NOMA Spectral efficiency Data collection Benchmark testing Autonomous aerial vehicles approximation algorithms Search problems Delays Internet of Things Reliability

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Iterative Recovery algorithms for Complex-Valued Distributed Compressed Sensing

Iterative Recovery Algorithms for Complex-Valued Distributed...

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International ITG Conference on Source and Channel Coding (SCC)

作者： Elena Sterk Robert F.H. Fischer Institute of Communications Engineering Ulm University Germany

ISBN: (数字)9798331522896

ISBN: (纸本)9798331522902

Distributed compressed sensing aims at the joint reconstruction of sparse signals with a common support. In some applications, complex-valued signals and sensing matrices are present. In this paper, we investigate recovery algorithms for complex-valued distributed scenarios. To that end, we review a compact exposition of complex- and vector-valued MMSE estimators. These can be used in approximate-message-passing-type algorithms. We explain joint reconstruction via iterative algorithms and evaluate suitable recovery algorithms. The performance of these algorithms is evaluated by numerical simulations for different scenarios.

关键词： Reviews approximation algorithms Numerical simulation Iterative algorithms Encoding Sensors Sparse matrices Compressed sensing

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Accuracy Improvement of Ray-Tracing-Based Received Power Prediction in Office Environments

Accuracy Improvement of Ray-Tracing-Based Received Power Pre...

引用

European Conference on Antennas and Propagation, EuCAP

作者： Azril Haniz Hirokazu Sawada Takeshi Matsumura Wireless Sytems Laboratory National Institute of Information and Communications Technology (NICT) Yokosuka Kanagawa Japan

ISBN: (数字)9788831299107

ISBN: (纸本)9798350366327

Ray-tracing (RT) generally suffers from errors in the calculated received power especially at low frequencies where objects may be on the same order or smaller than the wavelength due to the high-frequency approximation used. Previously, an algorithm to reduce this error by attenuating the calculated received power depending on the object size with respect to wavelength was proposed and evaluated in an industrial environment. In this paper, we verified that the proposed algorithm can be applied not only to industrial environments but also to other environments such as office environments. The adjusted received power was compared with measured received power at 922 MHz, 4850 MHz, and 28.35 GHz bands taken in an office environment. Results show that the proposed algorithm could reduce the RMSE of received power calculated by RT from 14.1 dB, 7.5 dB, and 4.1 dB to 9.0 dB, 5.3 dB, and 3.7 dB for each frequency, respectively.

关键词： Power measurement Accuracy 5G mobile communication Wavelength measurement Ray tracing Attenuation measurement Size measurement Prediction algorithms approximation algorithms Frequency measurement

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Performance Evaluation of Post-Quantum Cryptography algorithms for Secure Communication in Wireless Networks

Performance Evaluation of Post-Quantum Cryptography Algorith...

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Consumer Communications and Networking Conference, CCNC IEEE

作者： Babatunde Ojetunde Takuya Kurihara Kazuto Yano Toshikazu Sakano Hiroyuki Yokoyama Wave Engineering Laboratories Advanced Telecommunications Research Institute International Seika Soraku Kyoto Japan Adaptive Communications Research Laboratories Advanced Telecommunications Research Institute International Seika Soraku Kyoto Japan

ISBN: (数字)9798331508050

ISBN: (纸本)9798331508067

The need for secure communication in the advent of fully developed quantum computers is underscored by the ongoing standardization of Post-Quantum Cryptography algorithms (PQC). However, due to the complexity and long processing time of PQC algorithms, it is impractical to use them directly in most applications. Therefore, a practical implementation, especially in applications that may be vulnerable to quantum attacks, is essential. This paper proposes PQC-based and PQC-AES (Advanced Encryption Standard) hybrid Public Key Encryption (PKE) protocols to secure the communication of application data transmitted between two parties. The parties securely exchange their PQC keys using a PQC Key Encapsulation Mechanism (KEM) scheme. In the PQC-based PKE, the exchanged PQC public keys (asymmetric key cryptography) are used to encrypt data for network transmission. To decrypt the encrypted data, each party uses their private PQC secret key, known only to them, enabling secure end-to-end communication. In the PQC-AES hybrid PKE, a two-way shared secret key is used to generate a symmetric key (symmetric key cryptography) for encryption and decryption. The performance of the proposed protocols is evaluated through experiments with PQC algorithms in a client-server file transfer application. The evaluation results highlight the necessity of considering security, latency, and other metrics when implementing PQC algorithms in various applications. It is confirmed that KYBER1024 and BIKE-L1 achieved similar throughput in comparison to using the conventional AES-256 key encryption algorithm without extensive overheads in the wireless network for a smaller load (e.g., 1 KB size), while the PQC-AES hybrid cryptography protocol may be suitable for applications where the data size is larger,

关键词： Performance evaluation Protocols Wireless networks Public key Throughput approximation algorithms Hybrid power systems Encryption Complexity theory Servers

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