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Intelligent Solution System for Cloud Security Based on Equity Distribution:Model and Algorithms
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作者 Sarah Mustafa Eljack Mahdi Jemmali +3 位作者 Mohsen Denden Mutasim Al Sadig Abdullah M.Algashami Sadok Turki 《Computers, Materials & Continua》 SCIE EI 2024年第1期1461-1479,共19页
In the cloud environment,ensuring a high level of data security is in high demand.Data planning storage optimization is part of the whole security process in the cloud environment.It enables data security by avoiding ... In the cloud environment,ensuring a high level of data security is in high demand.Data planning storage optimization is part of the whole security process in the cloud environment.It enables data security by avoiding the risk of data loss and data overlapping.The development of data flow scheduling approaches in the cloud environment taking security parameters into account is insufficient.In our work,we propose a data scheduling model for the cloud environment.Themodel is made up of three parts that together help dispatch user data flow to the appropriate cloudVMs.The first component is the Collector Agent whichmust periodically collect information on the state of the network links.The second one is the monitoring agent which must then analyze,classify,and make a decision on the state of the link and finally transmit this information to the scheduler.The third one is the scheduler who must consider previous information to transfer user data,including fair distribution and reliable paths.It should be noted that each part of the proposedmodel requires the development of its algorithms.In this article,we are interested in the development of data transfer algorithms,including fairness distribution with the consideration of a stable link state.These algorithms are based on the grouping of transmitted files and the iterative method.The proposed algorithms showthe performances to obtain an approximate solution to the studied problem which is an NP-hard(Non-Polynomial solution)problem.The experimental results show that the best algorithm is the half-grouped minimum excluding(HME),with a percentage of 91.3%,an average deviation of 0.042,and an execution time of 0.001 s. 展开更多
关键词 Cyber-security cloud computing cloud security algorithms heuristicS
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Algorithms for Multicriteria Scheduling Problems to Minimize Maximum Late Work, Tardy, and Early
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作者 Karrar Alshaikhli Aws Alshaikhli 《Journal of Applied Mathematics and Physics》 2024年第2期661-682,共22页
This study examines the multicriteria scheduling problem on a single machine to minimize three criteria: the maximum cost function, denoted by maximum late work (V<sub>max</sub>), maximum tardy job, denote... This study examines the multicriteria scheduling problem on a single machine to minimize three criteria: the maximum cost function, denoted by maximum late work (V<sub>max</sub>), maximum tardy job, denoted by (T<sub>max</sub>), and maximum earliness (E<sub>max</sub>). We propose several algorithms based on types of objectives function to be optimized when dealing with simultaneous minimization problems with and without weight and hierarchical minimization problems. The proposed Algorithm (3) is to find the set of efficient solutions for 1//F (V<sub>max</sub>, T<sub>max</sub>, E<sub>max</sub>) and 1//(V<sub>max</sub> + T<sub>max</sub> + E<sub>max</sub>). The Local Search Heuristic Methods (Descent Method (DM), Simulated Annealing (SA), Genetic Algorithm (GA), and the Tree Type Heuristics Method (TTHM) are applied to solve all suggested problems. Finally, the experimental results of Algorithm (3) are compared with the results of the Branch and Bound (BAB) method for optimal and Pareto optimal solutions for smaller instance sizes and compared to the Local Search Heuristic Methods for large instance sizes. These results ensure the efficiency of Algorithm (3) in a reasonable time. 展开更多
关键词 Scheduling Single Machine Hierarchical Simultaneous Minimization algorithms Branch and Bound Local Search heuristic Methods
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Traffic flow of connected and automated vehicles at lane drop on two-lane highway: An optimization-based control algorithm versus a heuristic rules-based algorithm
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作者 刘华清 姜锐 +1 位作者 田钧方 朱凯旋 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期380-391,共12页
This paper investigates traffic flow of connected and automated vehicles at lane drop on two-lane highway. We evaluate and compare performance of an optimization-based control algorithm(OCA) with that of a heuristic r... This paper investigates traffic flow of connected and automated vehicles at lane drop on two-lane highway. We evaluate and compare performance of an optimization-based control algorithm(OCA) with that of a heuristic rules-based algorithm(HRA). In the OCA, the average speed of each vehicle is maximized. In the HRA, virtual vehicle and restriction of the command acceleration caused by the virtual vehicle are introduced. It is found that(i) capacity under the HRA(denoted as C_(H)) is smaller than capacity under the OCA;(ii) the travel delay is always smaller under the OCA, but driving is always much more comfortable under the HRA;(iii) when the inflow rate is smaller than C_(H), the HRA outperforms the OCA with respect to the fuel consumption and the monetary cost;(iv) when the inflow rate is larger than C_(H), the HRA initially performs better with respect to the fuel consumption and the monetary cost, but the OCA would become better after certain time. The spatiotemporal pattern and speed profile of traffic flow are presented, which explains the reason underlying the different performance. The study is expected to help for better understanding of the two different types of algorithm. 展开更多
关键词 traffic flow connected and automated vehicles(CAVs) lane drop optimization-based control algorithm heuristic rules-based algorithm
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Explainable Rules and Heuristics in AI Algorithm Recommendation Approaches——A Systematic Literature Review and Mapping Study
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作者 Francisco JoséGarcía-Penlvo Andrea Vázquez-Ingelmo Alicia García-Holgado 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第8期1023-1051,共29页
The exponential use of artificial intelligence(AI)to solve and automated complex tasks has catapulted its popularity generating some challenges that need to be addressed.While AI is a powerfulmeans to discover interes... The exponential use of artificial intelligence(AI)to solve and automated complex tasks has catapulted its popularity generating some challenges that need to be addressed.While AI is a powerfulmeans to discover interesting patterns and obtain predictive models,the use of these algorithms comes with a great responsibility,as an incomplete or unbalanced set of training data or an unproper interpretation of the models’outcomes could result in misleading conclusions that ultimately could become very dangerous.For these reasons,it is important to rely on expert knowledge when applying these methods.However,not every user can count on this specific expertise;non-AIexpert users could also benefit from applying these powerful algorithms to their domain problems,but they need basic guidelines to obtain themost out of AI models.The goal of this work is to present a systematic review of the literature to analyze studies whose outcomes are explainable rules and heuristics to select suitable AI algorithms given a set of input features.The systematic review follows the methodology proposed by Kitchenham and other authors in the field of software engineering.As a result,9 papers that tackle AI algorithmrecommendation through tangible and traceable rules and heuristics were collected.The reduced number of retrieved papers suggests a lack of reporting explicit rules and heuristics when testing the suitability and performance of AI algorithms. 展开更多
关键词 SLR systematic literature review artificial intelligence machine learning algorithm recommendation heuristicS explainability
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Analysis of Petri net model and task planning heuristic algorithms for product reconfiguration 被引量:1
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作者 林春深 Tang Xiaoqiang Duan Guanghong 《High Technology Letters》 EI CAS 2007年第3期254-260,共7页
Reconfiguration planning is recognized as an important factor for reducing the cost of manufacturing reconfigurable products, and the associated main task is to generate a set of optimal or near-optimal reconfiguratio... Reconfiguration planning is recognized as an important factor for reducing the cost of manufacturing reconfigurable products, and the associated main task is to generate a set of optimal or near-optimal reconfiguration sequences using some effect algorithms. A method is developed to generate a Petri net as the reconfiguration tree to represent two-state-transit of product, which solved the representation problem of reconfiguring interfaces replacement. Relating with this method, two heuristic algorithms are proposed to generate task sequences which considering economics to search reconfiguration paths effectively. At last, an objective evaluation is applied to compare these two heuristic algorithms to other ones. The developed reconfiguration task planning heuristic algorithms can generate better strategies and plans for reconfiguration. The research finds are exemplified with struts reconfiguration of reconfigurable parallel kinematics machine (RPKM). 展开更多
关键词 heuristic algorithms reconfiguration planning Petri net parallel kinematics machines
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Damage Identification of A TLP Floating Wind Turbine by Meta-Heuristic Algorithms 被引量:4
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作者 M.M.Ettefagh 《China Ocean Engineering》 SCIE EI CSCD 2015年第6期891-902,共12页
Damage identification of the offshore floating wind turbine by vibration/dynamic signals is one of the important and new research fields in the Structural Health Monitoring(SHM). In this paper a new damage identific... Damage identification of the offshore floating wind turbine by vibration/dynamic signals is one of the important and new research fields in the Structural Health Monitoring(SHM). In this paper a new damage identification method is proposed based on meta-heuristic algorithms using the dynamic response of the TLP(Tension-Leg Platform) floating wind turbine structure. The Genetic Algorithms(GA), Artificial Immune System(AIS), Particle Swarm Optimization(PSO), and Artificial Bee Colony(ABC) are chosen for minimizing the object function, defined properly for damage identification purpose. In addition to studying the capability of mentioned algorithms in correctly identifying the damage, the effect of the response type on the results of identification is studied. Also, the results of proposed damage identification are investigated with considering possible uncertainties of the structure. Finally, for evaluating the proposed method in real condition, a 1/100 scaled experimental setup of TLP Floating Wind Turbine(TLPFWT) is provided in a laboratory scale and the proposed damage identification method is applied to the scaled turbine. 展开更多
关键词 floating wind turbine multi-body dynamics damage identification meta-heuristic algorithms OPTIMIZATION
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Heuristic Scheduling Algorithms for Allocation of Virtualized Network and Computing Resources
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作者 Yichao Yang Yanbo Zhou +1 位作者 Zhili Sun Haitham Cruickshank 《Journal of Software Engineering and Applications》 2013年第1期1-13,共13页
Cloud computing technology facilitates computing-intensive applications by providing virtualized resources which can be dynamically provisioned. However, user’s requests are varied according to different applications... Cloud computing technology facilitates computing-intensive applications by providing virtualized resources which can be dynamically provisioned. However, user’s requests are varied according to different applications’ computation ability needs. These applications can be presented as meta-job of user’s demand. The total processing time of these jobs may need data transmission time over the Internet as well as the completed time of jobs to execute on the virtual machine must be taken into account. In this paper, we presented V-heuristics scheduling algorithm for allocation of virtualized network and computing resources under user’s constraint which applied into a service-oriented resource broker for jobs scheduling. This scheduling algorithm takes into account both data transmission time and computation time that related to virtualized network and virtual machine. The simulation results are compared with three different types of heuristic algorithms under conventional network or virtual network conditions such as MCT, Min-Min and Max-Min. e evaluate these algorithms within a simulated cloud environment via an abilenenetwork topology which is real physical core network topology. These experimental results show that V-heuristic scheduling algorithm achieved significant performance gain for a variety of applications in terms of load balance, Makespan, average resource utilization and total processing time. 展开更多
关键词 Cloud Computing Meta-Job Scheduling heuristic algorithm Load BALANCE NETWORK VIRTUALIZATION
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HEURISTIC PARTICLE SWARM OPTIMIZATION ALGORITHM FOR AIR COMBAT DECISION-MAKING ON CMTA 被引量:17
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作者 罗德林 杨忠 +2 位作者 段海滨 吴在桂 沈春林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第1期20-26,共7页
Combining the heuristic algorithm (HA) developed based on the specific knowledge of the cooperative multiple target attack (CMTA) tactics and the particle swarm optimization (PSO), a heuristic particle swarm opt... Combining the heuristic algorithm (HA) developed based on the specific knowledge of the cooperative multiple target attack (CMTA) tactics and the particle swarm optimization (PSO), a heuristic particle swarm optimization (HPSO) algorithm is proposed to solve the decision-making (DM) problem. HA facilitates to search the local optimum in the neighborhood of a solution, while the PSO algorithm tends to explore the search space for possible solutions. Combining the advantages of HA and PSO, HPSO algorithms can find out the global optimum quickly and efficiently. It obtains the DM solution by seeking for the optimal assignment of missiles of friendly fighter aircrafts (FAs) to hostile FAs. Simulation results show that the proposed algorithm is superior to the general PSO algorithm and two GA based algorithms in searching for the best solution to the DM problem. 展开更多
关键词 air combat decision-making cooperative multiple target attack particle swarm optimization heuristic algorithm
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Aheuristic Algorithm for Berth Scheduling Problem in Container Ports
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作者 张海滨 《科技信息》 2011年第3期I0185-I0186,共2页
In this paper,the berth scheduling problem is transformed into a special two-dimensional packing problem with some constraints.A nonlinear programming model for the problem is established,and a heuristic algorithm is ... In this paper,the berth scheduling problem is transformed into a special two-dimensional packing problem with some constraints.A nonlinear programming model for the problem is established,and a heuristic algorithm is proposed to solve the model.Simulation results show that the algorithm can improve the utilization of berths on discrete berth scheduling in the container port. 展开更多
关键词 BERTH SCHEDULING TWO-DIMENSIONAL PACKING heuristic algorithm
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基于改进A^(*)算法的矿用机器人救援路径规划及仿真分析 被引量:3
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作者 段碧英 柴肇云 +5 位作者 辛子朋 闫珂 肖畅 刘向御 李天宇 刘新雨 《太原理工大学学报》 CAS 北大核心 2024年第2期231-241,共11页
【目的】煤矿井下灾后现场情况复杂,针对传统A^(*)算法的煤矿机器人救援路径规划存在路径不安全、效率低等问题,结合栅格地图及救援机器人可沿任意方向移动的特点,多方面对传统A^(*)算法进行改进。【方法】首先,引入了机器人尺寸叠加到... 【目的】煤矿井下灾后现场情况复杂,针对传统A^(*)算法的煤矿机器人救援路径规划存在路径不安全、效率低等问题,结合栅格地图及救援机器人可沿任意方向移动的特点,多方面对传统A^(*)算法进行改进。【方法】首先,引入了机器人尺寸叠加到障碍物的概念,以确保路径的安全性。其次,通过优化启发函数,降低偏离最佳路径节点的扩展数量,减少冗余节点与路径转折,降低了计算复杂度。最后,采用动态调整算法将路径转折角圆弧化,对所得路径平滑处理,提高了路径的可操作性。最终获得路径代价更小、耗时更短、转弯次数更少的优化路径。基于改进的A^(*)算法,利用MATLAB开展了不同尺寸及不同障碍物覆盖率下救援机器人路径规划的仿真模拟试验。【结果】结果表明:相较于传统A^(*)算法,在崎岖环境地图中改进的A^(*)算法使搜索节点降低了26.51%、计算时长减少了80.42%、路径长度缩短了31.85%、转向次数减少了44.44%,提高了路径的搜索效率和平滑程度。【结论】改进的A^(*)算法为复杂工况环境下煤矿机器人的救援工作提供了一定的理论基础。 展开更多
关键词 A^(*)算法优化 煤矿救援机器人 路径规划 启发函数 动态调整算法
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A^(*)蚁群融合的复合启发式路径规划算法 被引量:2
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作者 陈焱 陆杰 李大鹏 《无线电通信技术》 北大核心 2024年第3期579-586,共8页
为提高无人机执行巡飞探查任务的效率,规划出一条最优的飞行路径,针对传统蚁群算法应用于路径规划时存在搜索效率低、迭代次数多、路径拐点多的问题,提出一种A^(*)蚁群融合的复合启发式路径规划算法。利用A^(*)算法预搜索差异化初始信息... 为提高无人机执行巡飞探查任务的效率,规划出一条最优的飞行路径,针对传统蚁群算法应用于路径规划时存在搜索效率低、迭代次数多、路径拐点多的问题,提出一种A^(*)蚁群融合的复合启发式路径规划算法。利用A^(*)算法预搜索差异化初始信息素,减少蚁群算法前期搜索盲目性,提高搜索效率。构造一种复合启发函数,引入A^(*)算法启发思想改进蚁群原本的启发式信息,设计路径平滑启发函数减少路径拐点。改进信息素更新规则,引入路径综合评分指标,使得每次迭代保留综合性能评分最优的路径。仿真实验表明,改进算法提高了搜索效率,一定程度上解决了拐点过多的问题,综合性能指标优于基本算法与对比文献算法,具有一定工程实践与理论研究意义。 展开更多
关键词 A^(*)算法 蚁群算法 路径规划 启发式
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Research on AGV task path planning based on improved A^(*) algorithm 被引量:1
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作者 Xianwei WANG Jiajia LU +2 位作者 Fuyang KE Xun WANG Wei WANG 《Virtual Reality & Intelligent Hardware》 2023年第3期249-265,共17页
Background Automatic guided vehicles(AGVs)have developed rapidly in recent years and have been used in several fields,including intelligent transportation,cargo assembly,military testing,and others.A key issue in thes... Background Automatic guided vehicles(AGVs)have developed rapidly in recent years and have been used in several fields,including intelligent transportation,cargo assembly,military testing,and others.A key issue in these applications is path planning.Global path planning results based on known environmental information are used as the ideal path for AGVs combined with local path planning to achieve safe and rapid arrival at the destination.Using the global planning method,the ideal path should meet the requirements of as few turns as possible,a short planning time,and continuous path curvature.Methods We propose a global path-planning method based on an improved A^(*)algorithm.The robustness of the algorithm was verified by simulation experiments in typical multiobstacle and indoor scenarios.To improve the efficiency of the path-finding time,we increase the heuristic information weight of the target location and avoid invalid cost calculations of the obstacle areas in the dynamic programming process.Subsequently,the optimality of the number of turns in the path is ensured based on the turning node backtracking optimization method.Because the final global path needs to satisfy the AGV kinematic constraints and curvature continuity condition,we adopt a curve smoothing scheme and select the optimal result that meets the constraints.Conclusions Simulation results show that the improved algorithm proposed in this study outperforms the traditional method and can help AGVs improve the efficiency of task execution by planning a path with low complexity and smoothness.Additionally,this scheme provides a new solution for global path planning of unmanned vehicles. 展开更多
关键词 Autonomous guided vehicle(AGV) Map modeling Global path planning Improved A^(*)algorithm Path optimization Bezier curves
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Heuristic algorithm for RCPSP with the objective of minimizing activities' cost 被引量:5
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作者 Liu Zhenyuan Wang Hongwei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第1期96-102,共7页
Resource-constrained project scheduling problem(RCPSP) is an important problem in research on project management. But there has been little attention paid to the objective of minimizing activities' cost with the re... Resource-constrained project scheduling problem(RCPSP) is an important problem in research on project management. But there has been little attention paid to the objective of minimizing activities' cost with the resource constraints that is a critical sub-problem in partner selection of construction supply chain management because the capacities of the renewable resources supplied by the partners will effect on the project scheduling. Its mathematic model is presented firstly, and analysis on the characteristic of the problem shows that the objective function is non-regular and the problem is NP-complete following which the basic idea for solution is clarified. Based on a definition of preposing activity cost matrix, a heuristic algorithm is brought forward. Analyses on the complexity of the heuristics and the result of numerical studies show that the heuristic algorithm is feasible and relatively effective. 展开更多
关键词 systems engineering resource-constrained project scheduling problem activities' cost preposing activity cost matrix heuristic algorithm.
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A Heuristic Algorithm for the Fabric Spreading and Cutting Problem in Apparel Factories 被引量:2
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作者 Xiuqin Shang Dayong Shen +1 位作者 Fei-Yue Wang Timo R. Nyberg 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第4期961-968,共8页
We study the fabric spreading and cutting problem in apparel factories.For the sake of saving the material costs,the cutting requirement should be met exactly without producing additional garment components.For reduci... We study the fabric spreading and cutting problem in apparel factories.For the sake of saving the material costs,the cutting requirement should be met exactly without producing additional garment components.For reducing the production costs,the number of lays that corresponds to the frequency of using the cutting beds should be minimized.We propose an iterated greedy algorithm for solving the fabric spreading and cutting problem.This algorithm contains a constructive procedure and an improving loop.Firstly the constructive procedure creates a set of lays in sequence,and then the improving loop tries to pick each lay from the lay set and rearrange the remaining lays into a smaller lay set.The improving loop will run until it cannot obtain any smaller lay set or the time limit is due.The experiment results on 500 cases show that the proposed algorithm is effective and efficient. 展开更多
关键词 Construction and improvement CUTTING and PACKING FABRIC SPREADING and CUTTING heuristic algorithm
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Data-Driven Heuristic Assisted Memetic Algorithm for Efficient Inter-Satellite Link Scheduling in the BeiDou Navigation Satellite System 被引量:6
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作者 Yonghao Du Ling Wang +2 位作者 Lining Xing Jungang Yan Mengsi Cai 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第11期1800-1816,共17页
Inter-satellite link(ISL)scheduling is required by the BeiDou Navigation Satellite System(BDS)to guarantee the system ranging and communication performance.In the BDS,a great number of ISL scheduling instances must be... Inter-satellite link(ISL)scheduling is required by the BeiDou Navigation Satellite System(BDS)to guarantee the system ranging and communication performance.In the BDS,a great number of ISL scheduling instances must be addressed every day,which will certainly spend a lot of time via normal metaheuristics and hardly meet the quick-response requirements that often occur in real-world applications.To address the dual requirements of normal and quick-response ISL schedulings,a data-driven heuristic assisted memetic algorithm(DHMA)is proposed in this paper,which includes a high-performance memetic algorithm(MA)and a data-driven heuristic.In normal situations,the high-performance MA that hybridizes parallelism,competition,and evolution strategies is performed for high-quality ISL scheduling solutions over time.When in quick-response situations,the data-driven heuristic is performed to quickly schedule high-probability ISLs according to a prediction model,which is trained from the high-quality MA solutions.The main idea of the DHMA is to address normal and quick-response schedulings separately,while high-quality normal scheduling data are trained for quick-response use.In addition,this paper also presents an easy-to-understand ISL scheduling model and its NP-completeness.A seven-day experimental study with 10080 one-minute ISL scheduling instances shows the efficient performance of the DHMA in addressing the ISL scheduling in normal(in 84 hours)and quick-response(in 0.62 hour)situations,which can well meet the dual scheduling requirements in real-world BDS applications. 展开更多
关键词 BeiDou Navigation Satellite System(BDS) data-driven heuristic inter-satellite link(ISL)scheduling memetic algorithm METAheuristic quick-response
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适合复杂环境的改进A^(*)路径规划算法
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作者 王志特 罗丽平 +1 位作者 廖义奎 吴伟林 《广西大学学报(自然科学版)》 CAS 北大核心 2024年第5期1099-1111,共13页
针对传统A算法在机器人路径规划中存在的缺陷,提出一种改进的A^(*)路径规划算法;对实际代价函数和预估代价函数进行动态权重分配,提高前端路径搜索的初始轨迹质量。结合曼哈顿距离和对角线距离设计非传统表达的启发函数,准确地估计每个... 针对传统A算法在机器人路径规划中存在的缺陷,提出一种改进的A^(*)路径规划算法;对实际代价函数和预估代价函数进行动态权重分配,提高前端路径搜索的初始轨迹质量。结合曼哈顿距离和对角线距离设计非传统表达的启发函数,准确地估计每个节点与目标节点的距离,实现全局路径最短,减少寻路时间和转向次数;针对大幅转角情况下路径不够平滑问题,应用贝塞尔曲线拟合生成的路径点。仿真结果表明:改进的A算法能够在复杂环境中生成最短全局路径,平均转向次数减少24.75%,平均寻路时间缩短30.66%,具有耗时短、转向次数少、路径更平滑等优点。 展开更多
关键词 机器人 路径规划 改进的A^(*)算法 代价函数 启发函数
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Designing an optimal stope layout for underground mining based on a heuristic algorithm 被引量:2
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作者 Sandanayake Don Suneth Sameera Topal Erkan Asad Mohammad Waqar Ali 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第5期767-772,共6页
An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in undergrou... An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in underground mine planning practice.However,the computational complexity in developing an optimal stope layout has been a reason for limited availability of the algorithms offering solution to this problem.This article shares a new and efficient heuristic algorithm that considers a three-dimensional ore body model as an input,maximizes the economic value,and satisfies the physical mining and geotechnical constraints for generating an optimal stope layout.An implementation at a copper deposit demonstrates the applicability and robustness of the algorithm.A parallel processing based modification improving the performance of the original algorithm in terms of enormous computational time saving is also presented. 展开更多
关键词 Stope optimization Underground mining Underground mine planning heuristic algorithm
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A Novel Heuristic Algorithm for theModeling and Risk Assessment of the COVID-19 Pandemic Phenomenon 被引量:2
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作者 Panagiotis G.Asteris Maria G.Douvika +6 位作者 Chrysoula A.Karamani Athanasia D.Skentou Katerina Chlichlia Liborio Cavaleri Tryfon Daras Danial J.Armaghani Theoklis E.Zaoutis 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第11期815-828,共14页
Themodeling and risk assessment of a pandemic phenomenon such as COVID-19 is an important and complicated issue in epidemiology,and such an attempt is of great interest for public health decision-making.To this end,in... Themodeling and risk assessment of a pandemic phenomenon such as COVID-19 is an important and complicated issue in epidemiology,and such an attempt is of great interest for public health decision-making.To this end,in the present study,based on a recent heuristic algorithm proposed by the authors,the time evolution of COVID-19 is investigated for six different countries/states,namely New York,California,USA,Iran,Sweden and UK.The number of COVID-19-related deaths is used to develop the proposed heuristic model as it is believed that the predicted number of daily deaths in each country/state includes information about the quality of the health system in each area,the age distribution of population,geographical and environmental factors as well as other conditions.Based on derived predicted epidemic curves,a new 3D-epidemic surface is proposed to assess the epidemic phenomenon at any time of its evolution.This research highlights the potential of the proposed model as a tool which can assist in the risk assessment of the COVID-19.Mapping its development through 3D-epidemic surface can assist in revealing its dynamic nature as well as differences and similarities among different districts. 展开更多
关键词 algorithm COVID-19 Gaussian-function heuristic model pandemic trend prediction SARS-CoV-2
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Research on Different Heuristics for Minimax Algorithm Insight from Connect-4 Game 被引量:2
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作者 Xiyu Kang Yiqi Wang Yanrui Hu 《Journal of Intelligent Learning Systems and Applications》 2019年第2期15-31,共17页
Minimax algorithm and machine learning technologies have been studied for decades to reach an ideal optimization in game areas such as chess and backgammon. In these fields, several generations try to optimize the cod... Minimax algorithm and machine learning technologies have been studied for decades to reach an ideal optimization in game areas such as chess and backgammon. In these fields, several generations try to optimize the code for pruning and effectiveness of evaluation function. Thus, there are well-armed algorithms to deal with various sophisticated situations in gaming occasion. However, as a traditional zero-sum game, Connect-4 receives less attention compared with the other members of its zero-sum family using traditional minimax algorithm. In recent years, new generation of heuristics is created to address this problem based on research conclusions, expertise and gaming experiences. However, this paper mainly introduced a self-developed heuristics supported by well-demonstrated result from researches and our own experiences which fighting against the available version of Connect-4 system online. While most previous works focused on winning algorithms and knowledge based approaches, we complement these works with analysis of heuristics. We have conducted three experiments on the relationship among functionality, depth of searching and number of features and doing contrastive test with sample online. Different from the sample based on summarized experience and generalized features, our heuristics have a basic concentration on detailed connection between pieces on board. By analysing the winning percentages when our version fights against the online sample with different searching depths, we find that our heuristics with minimax algorithm is perfect on the early stages of the zero-sum game playing. Because some nodes in the game tree have no influence on the final decision of minimax algorithm, we use alpha-beta pruning to decrease the number of meaningless node which greatly increases the minimax efficiency. During the contrastive experiment with the online sample, this paper also verifies basic characters of the minimax algorithm including depths and quantity of features. According to the experiment, these two characters can both effect the decision for each step and none of them can be absolutely in charge. Besides, we also explore some potential future issues in Connect-4 game optimization such as precise adjustment on heuristic values and inefficiency pruning on the search tree. 展开更多
关键词 heuristicS MINIMAX algorithm ZERO-SUM GAME Connect-4 GAME
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A Multi-stage Heuristic Algorithm for Matching Problem in the Modified Miniload Automated Storage and Retrieval System of E-commerce 被引量:2
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作者 WANG Wenrui WU Yaohua WU Yingying 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第3期641-648,共8页
E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking d... E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center. 展开更多
关键词 e-commerce modified miniload automated storage/retrieval system matching problem multi-stage heuristic algorithm
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