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作者： Merkulov, Gleb Iceland, Eran Michaeli, Shay Riechkind, Yosef Gal, Oren Barel, Ariel Shima, Tal Technion Israel Inst Technol Fac Aerosp Engn IL-3200003 Haifa Israel Hebrew Univ Jerusalem IL-9190501 Jerusalem Israel Technion Israel Inst Technol IL-3200003 Haifa Israel Open Univ Israel Fac Comp Sci IL-4353701 Raanana Israel Technion Israel Inst Technol Fac Comp Sci IL-3200003 Haifa Israel

ISBN: (数字)9781624107115

ISBN: (纸本)9781624107115

Multiple-missile attack is one of the simplest ways to saturate and overcome a missile defense system. To increase intercept efficiency against such groups of attackers, it is necessary to allocate the interceptors according to their kinematic limitations. Moreover, such an allocation scheme has to be scalable in order to cope with large scenarios and allow for dynamic reallocation. In this paper we first propose a new formulation of such a Weapon-Target Assignment (WTA) problem and offer a decentralized approach to solve it using Reinforcement Learning (RL) as well as a greedy search algorithm. The engagement is considered from the viewpoint of each pursuer vs. all the targets. Simultaneously, other interceptors engage the target group, and their allocation and success probabilities are available to other team members. To improve the mid-course trajectory shaping, static virtual targets are placed between the pursuers and the incoming adversaries. Each interceptor selects its target dynamically according to a policy that was learned from a large number of scenarios in the computation-efficient simulation environment. The RL input state contains the interceptor reachability coverage of the targets and the probabilities of success of other missiles. The RL reward aggregates the team performance to encourage cooperation on the allocation level. The relevant reachability constraints are obtained analytically by employing kinematic approximations of the interceptor motion. The use of RL ensures real-time scalable and dynamic reallocation for all interceptors. We compare the performance of the proposed RL-based decentralized WTA and guidance scheme against a greedy solution, showing the performance advantage of RL.

关键词： Reinforcement Learning Weapon Target Assignment Search algorithm Missile Defense Guidance Laws greedy algorithm Brute Force Search Proportional Navigation Control Allocation Kinematics Models

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Contact pattern,current immune barrier,and pathogen virulence determines the optimal strategy of further vaccination

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Infectious Disease Modelling 2023年第1期8卷 192-202页

作者： Xiaohao Guo Ziyan Liu Shiting Yang Zeyu Zhao Yichao Guo Guzainuer Abudurusuli Shanlu Zhao Ge Zeng Shixiong Hu Kaiwei Luo Tianmu Chen State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics School of Public HealthXiamen UniversityXiamen City361102Fujian ProvincePeople's Republic of China Hunan Provincial Center for Disease Control and Prevention 405 Furong Middle Road Section OneKaifu DistrictChangsha City410001Hunan ProvincePeople's Republic of China

Background:The current outbreak of novel coronavirus disease 2019 has caused a seriousdisease burden *** are an important factor to sustain the *** with a relatively high-vaccination worldwide,the decay of vaccine efficacy andthe arising of new variants lead us to the challenge of maintaining a sufficient immunebarrier to protect the ***:A case-contact tracking data in Hunan,China,is used to estimate the contactpattern of cases for scenarios including school,workspace,etc,rather than ordinary susceptible *** on the estimated vaccine coverage and efficacy,a multi-groupvaccinated-exposed-presymptomatic-symptomatic-asymptomatic-removed model(VEFIAR)with 8 age groups,with each partitioned into 4 vaccination status groups *** optimal dose-wise vaccinating strategy is optimized based on the currentlyestimated immunity barrier of coverage and efficacy,using the greedy algorithm thatminimizes the cumulative cases,population size of hospitalization and fatality respectivelyin a certain future *** of Delta and Omicron variants are used respectivelyin the ***:The estimated contact matrices of cases showed a concentration on middle ages,and has compatible magnitudes compared to estimations from contact surveys in *** VEFIAR model is numerically *** optimal controled vaccination strategy requires immediate vaccination on the un-vaccinated high-contact population of age30e39 to reduce the cumulative cases,and is stable with different basic reproductionnumbers(R_(0)).As for minimizing hospitalization and fatality,the optimized strategy requires vaccination on the un-vaccinated of both aged 30e39 of high contact frequencyand the vulnerable ***:The objective of reducing transmission requires vaccination in age groups ofthe highest contact frequency,with more priority for un-vaccinated than un-fully or *** objective of reducing total ho

关键词： Vaccine Allocation strategy SARS-CoV-2 Optimal control Immune barrier Contact pattern greedy algorithm

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A Weight-based greedy algorithm for Target Coverage Problem in Wireless Sensor networks 1

A Weight-based Greedy Algorithm for Target Coverage Problem ...

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1st International Conference on Computer, Communications, and Control Technology (I4CT)

作者： Diop, Babacar Diongue, Dame Thiare, Ousmane Gaston Berger Univ BP 234 St Louis Senegal

ISBN: (纸本)9781479945559

Recent improvements in affordable and efficient integrated electronic devices have enabled a wide range of applications in the estate of wireless sensor networks. An important issue addressed in wireless sensor networks is the coverage problem. This latter is centered on a fundamental question: how well do the sensors observe the physical space? A major challenge in coverage problem is how to maximize the lifetime of the network while ensuring coverage of a set of targets. To achieve this, the usual process, consists on scheduling sensors activity, which enables energy dissipation control. Scheduling process goes by activating sensors by round such that in each round, only one subset of sensors that satisfies the coverage requirement is activated, while all other sensors are in a low energy mode and will be activated later. In this paper, we propose a weight-based greedy algorithm (WGA) which organizes sensors in multiple subsets. Our objective is to partition an initial set of sensors into a maximum possible number of sensors set covers (SSCs), which can completely monitor targets in a region of interest. Performance evaluation of WGA have proven its efficiency over some well-known algorithms proposed in the literature, in term of computed set covers.

关键词： Wireless Sensor Network Target coverage Sensor Set Cover greedy algorithm

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A probabilistic greedy algorithm with forced assignment and compression for fast frequency assignment in cellular network 13

A probabilistic greedy algorithm with forced assignment and ...

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13th IEEE International Symposium on Network Computing and Applications (NCA)

作者： Ghosal, Subhankar Ghosh, Sasthi C. Indian Stat Inst Adv Comp & Microelect Unit Kolkata 700108 India

ISBN: (纸本)9781479953936

This paper presents a probabilistic greedy algorithm for solving the channel assignment problem (CAP) in cellular networks. We took each call as a vertex of a complete edge weighed graph, termed as CAP graph, where an edge weight represents the minimum frequency separation needed between the calls represented by the terminal vertices of that edge. Our objective is to assign non-negative integers representing colors or frequencies to the vertices of the CAP graph such that the required span (maximum frequency - minimum frequency) is minimized while satisfying the frequency separation constraints represented by the edge weights. We begin with a probabilistic ordering of the vertices and apply frequency exhaustive strategy to color them. During the coloring, when color of a vertex exceeds the maximum color of previously allocated vertices, we apply a forced assignment phase to reduce the so far obtained span. Finally we propose an iterative compression phase to further reduce the span obtained from applying the frequency exhaustive strategy with forced assignment phase. The proposed polynomial time algorithm is then applied over the well-known benchmark instances and the obtained spans are measured. The obtained results show that the proposed algorithm performs better that the existing assignment strategies with respect to deviation from optimality and computation time. The time taken by our algorithm is less than 1.77 seconds (HP Z400 Workstation) even for the most difficult benchmark instances and thus is very much suitable where fast channel assignment is of primary importance while a marginal deviation from optimality may be tolerated.

关键词： Basestations Benchmarktesting Color greedyalgorithms Interference Probabilisticlogic Vectors Color frequency assignment Cellular networks vertex head greedy algorithm minimum frequency frequency separation optimality Forced interference Hats common agricultural policy SERPINB6 gene CAPS Cap

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The research of greedy algorithm On Cognitive Radio 4

The research of Greedy Algorithm On Cognitive Radio

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4th International Conference on Instrumentation and Measurement, Computer, Communication and Control (IMCCC)

作者： Liu Wen Li Xin Li Hanchao An Yuanyuan HUST Coll Measure Control Technol & Commun Engn Harbin 150080 Peoples R China

ISBN: (纸本)9781479965755

greedy algorithm for which situation of users' number more than free channel's number gives tacit consent to each user could receive one sub-channel. This is very different from virtual situation. For this reason, this text has improved the greedy algorithm. In allocation progress of spectrum resources, the conflict of secondary users and authorized users on time domain has to be considered, and also the competition between secondary users on frequency domain. On time domain, utilizing probability to describe the influence which conflict bring to systematic total benefit. On frequency domain, using decreased number of channels to characterize the competitive relationship between each secondary user. The improved greedy algorithm has better systematic total throughput and property of competitive auction system transmittal data quantity for each time. It is able to tackle the problem of unreasonable allocation for resource management. And then, give secondary users more effective and more possibility of spectrum access, improved the situation of spectrum resources deficiency.

关键词： greedy algorithm Spectrum allocation Time domain Frequency domain

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Fractional 0-1 programming and submodularity

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JOURNAL OF GLOBAL OPTIMIZATION 2022年第1期84卷 77-93页

作者： Han, Shaoning Gomez, Andres Prokopyev, Oleg A. Univ Southern Calif Ind & Syst Engn Los Angeles CA 90089 USA Univ Pittsburgh Ind Engn Pittsburgh PA 15261 USA

In this note we study multiple-ratio fractional 0-1 programs, a broad class ofNP-hard combinatorial optimization problems. In particular, under some relatively mild assumptions we provide a complete characterization of the conditions, which ensure that a single-ratio function is submodular. Thenwe illustrate our theoretical results with the assortment optimization and facility location problems, and discuss practical situations that guarantee submodularity in the considered application settings. In such cases, near-optimal solutions formultiple-ratio fractional 0-1 programs can be found via simple greedy algorithms.

关键词： Fractional 0-1 programming Hyperbolic 0-1 programming Multiple ratios Single ratio Submodularity Assortment optimization Facility location greedy algorithm

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On Guha and Khuller's greedy algorithm for Finding a Minimum CDS for Unit Disk Graphs 2

On Guha and Khuller's Greedy Algorithm for Finding a Minimum...

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International Symposium on Computing and Networking CANDAR

作者： Fujita, Satoshi Hiroshima Univ Dept Informat Engn Higashihiroshima 7398527 Japan

ISBN: (纸本)9781479941520

A connected dominating set (CDS, for short) for graph G is a dominating set which induces a connected subgraph of G. In this paper, we consider the problem of finding a minimum CDS for unit disk graphs, which have recently attracted considerable attention as a model of virtual backbone in multi-hop wireless networks. This optimization problem is known to be NP-hard and many approximation algorithms have been proposed in the literature. This paper proves a lower bound on the performance ratio of a greedy algorithm proposed by Guha and Khuller which was originally proposed for general graphs. More specifically, we show that for any fixed epsilon > 0 and integer n(0) >= 1, there is a unit disk graph with bounded degree consisting of at least n0 vertices for which the output of the greedy algorithm is no better than 3 - epsilon times of an optimum solution to the same graph.

关键词： Connected dominating set unit disk graph greedy algorithm performance ratio

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greedy sensor selection based on QR factorization

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EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2021年第1期2021卷 1-13页

作者： Kim, Yoon Hak Chosun Univ Coll IT Convergence Engn Dept Elect Engn 309 Pilmun Daero Gwangju 61452 South Korea

We address the problem of selecting a given number of sensor nodes in wireless sensor networks where noise-corrupted linear measurements are collected at the selected nodes to estimate the unknown parameter. Noting that this problem is combinatorial in nature and selection of sensor nodes from a large number of nodes would require unfeasible computational cost, we propose a greedy sensor selection method that seeks to choose one node at each iteration until the desired number of sensor nodes are selected. We first apply the QR factorization to make the mean squared error (MSE) of estimation a simplified metric which is iteratively minimized. We present a simple criterion which enables selection of the next sensor node minimizing the MSE at iterations. We discuss that a near-optimality of the proposed method is guaranteed by using the approximate supermodularity and also make a complexity analysis for the proposed algorithm in comparison with different greedy selection methods, showing a reasonable complexity of the proposed method. We finally run extensive experiments to investigate the estimation performance of the different selection methods in various situations and demonstrate that the proposed algorithm provides a good estimation accuracy with a competitive complexity when compared with the other novel greedy methods.

关键词： greedy algorithm Sensor selection Linear inverse problem Near-optimality QR factorization

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The Optimal and the greedy: Drone Association and Positioning Schemes for Internet of UAVs

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IEEE INTERNET OF THINGS JOURNAL 2021年第18期8卷 14066-14079页

作者： El Hammouti, Hajar Hamza, Doha Shihada, Basem Alouini, Mohamed-Slim Shamma, Jeff S. King Abdullah Univ Sci & Technol CEMSE Div Thuwal 23955 Saudi Arabia Mohammed VI Polytech Univ Sch Comp Sci Benguerir 43150 Morocco Univ Illinois Ind & Enterprise Syst Engn Champaign IL 61801 USA

This work considers the deployment of unmanned aerial vehicles (UAVs) over a predefined area to serve a number of ground users. Due to the heterogeneous nature of the network, the UAVs may cause severe interference to the transmissions of each other. Hence, a judicious design of the user-UAV association and UAV locations is desired. A potential game is defined where the players are the UAVs. The potential function is the total sum rate of the users. The agents' utility in the potential game is their marginal contribution to the global welfare or their so-called wonderful life utility. A game-theoretic learning algorithm, binary log-linear learning (BLLL), is then applied to the problem. Given the potential game structure, a consequence of our utility design, the stochastically stable states using BLLL are guaranteed to be the potential maximizers. Hence, we optimally solve the joint user-UAV association and 3-D-location problem. Next, we exploit the submodular features of the sum rate function for a given configuration of UAVs to design an efficient greedy algorithm. Despite the simplicity of the greedy algorithm, it comes with a performance guarantee of 1 - 1/e of the optimal solution. To further reduce the number of iterations, we propose another heuristic greedy algorithm that provides very good results. Our simulations show that, in practice, the proposed greedy approaches achieve significant performance in a few iterations.

关键词： Binary log-linear learning (BLLL) greedy algorithm potential game unmanned aerial vehicle (UAV) 3-D placement UAV-enabled networks users-UAVs association

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Ensuring Synchronization in Multilevel Measurement Systems

Ensuring Synchronization in Multilevel Measurement Systems

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2024 Conference of Young Researchers in Electrical and Electronic Engineering, ElCon 2024

作者： Korolev, Pavel G. Pankov, Anton V. Beliaev, Fedor I. Aspednikov, Egor A. Udelnov, Mikhail S. Zhuravlev, Daniil A. Saint-Petersburg Electrotechnical University 'LETI' Department of Information Measuring Systems and Technologies Saint Petersburg Russia

ISBN: (纸本)9798350360646

The article is devoted to the development of a multilevel synchronization method. The considered structure includes levels of compact information-measuring systems (CIMS), local information-measuring systems (LIMS) and distributed information-measuring system (DIMS). The method envisages analysis of dynamic capabilities of hardware and their compliance with the requirements of the task for the experiment, development of synchronization tables for CIMS, LIMS, and DIMS levels. The structure of synchronization tables depends on what level of the distributed system is assigned the task of acceptable error minimization of the temporal shift of the compact system frames. The article reviews the most common case when the simultaneity of launching synchronization frames of compact information-measuring systems is ensured at the level of local information-measuring systems. The rules of multilevel synchronization are developed, which guarantee the obtaining of the results of indirect and joint changes at the level of local systems with the delay error not exceeding the specified one. © 2024 IEEE.

关键词： efficiency criteria error minimization of the temporal shift greedy algorithm measurement system

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