Design of efficient parallel algorithms on shared memory multiprocessors

The design of parallel algorithms is studied in this paper. These algorithms are applicable to shared memory MIMD machines In this paper, the emphasis is put on the methods for design of the efficient parallel algorithms. The design of efficient parallel algorithms should be based on the following considerationst algorithm parallelism and the hardware-parallelism; granularity of the parallel algorithm, algorithm optimization according to the underling parallel machine. In this paper , these principles are applied to solve a model problem of the PDE. The speedup of the new method is high. The results were tested and evaluated on a shared memory MIMD machine. The practical results were agree with the predicted performance.

A New Delay-Constrained Multicast Routing Algorithm Based on Shared Edges

In this paper, we made a detail analysis for the ESAMPH algorithm, and proposed ESAMPH_D algorithm according to the insufficient of ESAMPH algorithm. The ESAMPH_D algorithm does not consider those paths that do not satisfy the delay constraint, so we can ensure that all paths be taken into account will meet the limit of delay constraint, then we find the least costly path in order to build a minimum cost multicast tree. Simulation results show that the algorithm is better than ESAMPH algorithm in performance.

Two-Machine Hybrid Flow-Shop Problems in Shared Manufacturing

In the“shared manufacturing”environment,based on fairness,shared manufacturing platforms often require manufacturing service enterprises to arrange production according to the principle of“order first,finish first”which leads to a series of scheduling problems with fixed processing sequences.In this paper,two two-machine hybrid flow-shop problems with fixed processing sequences are studied.Each job has two tasks.The first task is flexible,which can be processed on either of the two machines,and the second task must be processed on the second machine after the first task is completed.We consider two objective functions:to minimize the makespan and tominimize the total weighted completion time.First,we show the problem for any one of the two objectives is ordinary NP-hard by polynomial-time Turing Reduction.Then,using the Continuous ProcessingModule(CPM),we design a dynamic programming algorithm for each case and calculate the time complexity of each algorithm.Finally,numerical experiments are used to analyze the effect of dynamic programming algorithms in practical operations.Comparative experiments show that these dynamic programming algorithms have comprehensive advantages over the branch and bound algorithm(a classical exact algorithm)and the discrete harmony search algorithm(a high-performance heuristic algorithm).

Non-Cooperative Game of Coordinated Scheduling of Parallel Machine Production and Transportation in Shared Manufacturing

Given the challenges of manufacturing resource sharing and competition in the modern manufacturing industry,the coordinated scheduling problem of parallel machine production and transportation is investigated.The problem takes into account the coordination of production and transportation before production as well as the disparities in machine spatial position and performance.A non-cooperative game model is established,considering the competition and self-interest behavior of jobs from different customers for machine resources.The job from different customers is mapped to the players in the game model,the corresponding optional processing machine and location are mapped to the strategy set,and the makespan of the job is mapped to the payoff.Then the solution of the scheduling model is transformed into the Nash equilibrium of the non-cooperative game model.A Nash equilibrium solution algorithm based on the genetic algorithm(NEGA)is designed,and the effective solution of approximate Nash equilibrium for the game model is realized.The fitness function,single-point crossover operator,and mutation operator are derived from the non-cooperative game model’s characteristics and the definition of Nash equilibrium.Rules are also designed to avoid the generation of invalid offspring chromosomes.The effectiveness of the proposed algorithm is demonstrated through numerical experiments of various sizes.Compared with other algorithms such as heuristic algorithms(FCFS,SPT,and LPT),the simulated annealing algorithm(SA),and the particle swarm optimization algorithm(PSO),experimental results show that the proposed NE-GA algorithm has obvious performance advantages.

Shared Cache Based on Content Addressable Memory in a Multi-Core Architecture

Modern shared-memory multi-core processors typically have shared Level 2(L2)or Level 3(L3)caches.Cache bottlenecks and replacement strategies are the main problems of such architectures,where multiple cores try to access the shared cache simultaneously.The main problem in improving memory performance is the shared cache architecture and cache replacement.This paper documents the implementation of a Dual-Port Content Addressable Memory(DPCAM)and a modified Near-Far Access Replacement Algorithm(NFRA),which was previously proposed as a shared L2 cache layer in a multi-core processor.Standard Performance Evaluation Corporation(SPEC)Central Processing Unit(CPU)2006 benchmark workloads are used to evaluate the benefit of the shared L2 cache layer.Results show improved performance of the multicore processor’s DPCAM and NFRA algorithms,corresponding to a higher number of concurrent accesses to shared memory.The new architecture significantly increases system throughput and records performance improvements of up to 8.7%on various types of SPEC 2006 benchmarks.The miss rate is also improved by about 13%,with some exceptions in the sphinx3 and bzip2 benchmarks.These results could open a new window for solving the long-standing problems with shared cache in multi-core processors.

Dynamic Allocation of Manufacturing Tasks and Resources in Shared Manufacturing

Shared manufacturing is recognized as a new point-to-point manufac-turing mode in the digital era.Shared manufacturing is referred to as a new man-ufacturing mode to realize the dynamic allocation of manufacturing tasks and resources.Compared with the traditional mode,shared manufacturing offers more abundant manufacturing resources and flexible configuration options.This paper proposes a model based on the description of the dynamic allocation of tasks and resources in the shared manufacturing environment,and the characteristics of shared manufacturing resource allocation.The execution of manufacturing tasks,in which candidate manufacturing resources enter or exit at various time nodes,enables the dynamic allocation of manufacturing tasks and resources.Then non-dominated sorting genetic algorithm(NSGA-II)and multi-objective particle swarm optimization(MOPSO)algorithms are designed to solve the model.The optimal parameter settings for the NSGA-II and MOPSO algorithms have been obtained according to the experiments with various population sizes and iteration numbers.In addition,the proposed model’s efficiency,which considers the entries and exits of manufacturing resources in the shared manufacturing environment,is further demonstrated by the overlap between the outputs of the NSGA-II and MOPSO algorithms for optimal resource allocation.

基于多空间数据查询安全共享算法研究

针对信息共享的安全性,文中提出一种基于多空间数据的安全共享算法。结合R树和TOP-K方法,对多空间数据进行分割,实现对多个维度的隐私保护,提高数据处理效率;采用RSA算法对数据进行加密和权限控制,防止未经授权的访问和数据泄露;引入拉普拉斯机制对多空间数据进行加噪处理,以平衡隐私保护和数据准确性。使用K-means算法在Oldenburg数据集和SPE数据集中进行聚类后开展实验,结果显示,该算法在保护隐私的同时,具有较好的查询性能。

考虑需求提前满足的第三方共享制造平台产能跨周期匹配问题研究

随着新一代信息技术与制造业的深度融合,第三方共享制造平台迅速发展。针对第三方共享制造平台的产能匹配问题,考虑平台提前满足制造商需求以及产能数量和价格约束,本文构建了二层多目标优化模型。其中,下层模型用于优化当前周期的匹配策略,上层模型用于决策是否提前满足制造商的需求。本文结合贪心算法和搜索算法设计了求解方法,该方法先通过贪心算法产生初始解,再采用混合策略搜索算法对初始解进行优化。最后,在数值实验部分,本文将CPLEX求解结果与研究所得结果相比,证明了算法的有效性。研究表明,本文所提算法不仅减少了模型的求解时间,还保证了解的质量和精度,为第三方共享制造平台解决跨周期的产能匹配问题提供了一种参考方法。

基于区块链的电子病历安全高效共享方法

针对医疗机构之间共享电子病历所面临的挑战,如隐私泄露风险和低效的检索问题,提出一种基于区块链的电子病历高效加密检索与共享方案.首先,该方案一方面通过在云服务器上存储加密后的电子病历,并在联盟链上实施检索过程,有效地实现了存储与检索的分离;另一方面加入混淆陷门集合,从而显著降低了关键字猜测攻击的风险.其次,考虑到医疗数据的特殊性,提出一种优化的倒排索引结构,有效解决了处理大量电子病历时的检索效率问题.最后,基于此索引结构,开发了一种密文检索算法,该算法通过结合可搜索加密中的陷门技术和倒排索引中的关键字密文,实现了高效的密文检索.实验结果显示,该方案在实现隐私保护的前提下,成功解决了医疗行业电子病历共享的问题,同时显著提升了系统的运行效率.

基于多目标平衡优化器的共享储能容量优化

随着绿色能源的大量投入使用,对储能装置的需求也相应增加,要求按比例配套投入,以有效应对电网供需双侧的不确定性,这带来了投资成本过高和回收周期过长的问题。为了应对绿色能源广泛应用带来的储能挑战,提出了一种多微电网储能装置共享模型,旨在显著减少整体储能容量的需求。为实现这一目标,设计了一种双层优化方法,并提出了一种多目标平衡优化器用以求解上层模型,避免结果陷入局部最优。通过数据实验验证,与传统的分布式储能方式相比,多微电网储能装置共享模型使系统所需的储能容量降低了43.30%。同时,算法对比结果表明,所提多目标优化算法具有足够的竞争力。

基于ISSA-Stacking集成学习的共享单车租赁量预测

针对共享单车供需不平衡问题,结合Stacking算法和改进麻雀搜索算法(improved sparrow search algorithm,ISSA),提出了一种基于ISSA-Stacking算法的共享单车租赁量预测模型。首先,利用相关性分析法和轻量级梯度提升机进行特征选择;然后,建立多种异质回归预测模型并采用ISSA对各模型的关键超参数进行优化,通过引入精英反向学习策略和自适应种群比例因子来提高麻雀搜索算法的全局搜索能力和收敛速度;最后,利用Stacking算法的集成学习思想对各模型进行融合。实验使用美国华盛顿地区的共享单车出行数据进行租赁量预测,通过对比分析验证了所提融合模型相比单一模型在共享单车租赁量预测方面具有更高的预测精度。

基于全寿命周期的共享储能优化配置及经济性研究

随着储能技术与共享经济逐渐成熟,共享储能商业模式也逐渐普及并应用于实际情况中。然而,共享储能电站具体收益等相关问题尚不明确,这也限制了该商业模式在规模化应用中的进一步推广。提出考虑新能源消纳的共享储能电站优化运行方法,建立考虑全寿命周期的共享储能电站成本模型并分析储能效益来源;将全寿命周期内共享储能成本进行等年值转换分析,以其在典型日调度时间内净收益最大为目标建立模型;采用改进黏菌优化算法对共享储能电站容量配置、充放电行为以及运行状态寻找最优解。算例分析显示,用该方法配置共享储能后,共享储能电站所需容量成本较各用户配置分散式储能电站下降29.49%,当共享储能服务商将服务费设定为0.238元/(kW·h)时,可在8年内收回投资成本。

SLID: A Secure Lowest-ID Clustering Algorithm

In order to solve security problem of clustering algorithm, we proposed amethod to enhance the security of the well-known lowest-ID clustering algorithm. This method isbased on the idea of the secret sharing and the (k, n) threshold cryptography, Each node, whetherclusterhead or ordinary member, holds a share of the global certificate, and any k nodes cancommunicate securely. There is no need for any clusterhead to execute extra functions more thanrouting. Our scheme needs some prior configuration before deployment, and can be used in criticalenvironment with small scale. The security-enhancement for Lowest-ID algorithm can also be appliedinto other clustering approaches with minor modification. The feasibility of this method wasverified bythe simulation results.

Multi-path planning algorithm based on fitness sharing and species evolution

A new algorithm is proposed for underwater vehicles multi-path planning. This algorithm is based on fitness sharing genetic algorithm, clustering and evolution of multiple populations, which can keep the diversity of the solution path, and decrease the operating time because of the independent evolution of each subpopulation. The multi-path planning algorithm is demonstrated by a number of two-dimensional path planning problems. The results show that the multi-path planning algorithm has the following characteristics: high searching capability, rapid convergence and high reliability.

A Novel GLS Consensus Algorithm for Alliance Chain in Edge Computing Environment

Edge computing devices are widely deployed.An important issue that arises is in that these devices suffer from security attacks.To deal with it,we turn to the blockchain technologies.The note in the alliance chain need rules to limit write permissions.Alliance chain can provide security management functions,using these functions to meet the management between the members,certification,authorization,monitoring and auditing.This article mainly analyzes some requirements realization which applies to the alliance chain,and introduces a new consensus algorithm,generalized Legendre sequence(GLS)consensus algorithm,for alliance chain.GLS algorithms inherit the recognition and verification efficiency of binary sequence ciphers in computer communication and can solve a large number of nodes verification of key distribution issues.In the alliance chain,GLS consensus algorithm can complete node address hiding,automatic task sorting,task automatic grouping,task node scope confirmation,task address binding and stamp timestamp.Moreover,the GLS consensus algorithm increases the difficulty of network malicious attack.

基于侧链和信任管理模型的数据共享方案

为解决在不信任的区块链环境中由于数据转售而造成的用户不愿共享数据等问题,提出一种基于侧链和信任管理模型的数据共享方案。使用信任管理模型量化节点信任值,将节点信任值集成到数据共享智能合约中,为用户提供可信的共享环境和动态的访问控制接口。对联盟链进行侧链扩容,使用信任管理模型优化共识算法。规定主链使用具有拜占庭容错能力的T-PBFT算法,侧链使用仅适用于高信任场景的T-Raft算法。用户根据预先设置的阈值动态决定在主链或侧链共享数据。实验就方案的安全性和性能进行分析,表明了该方案的可行性和有效性。

数字检察的法治边界

数字检察改革是指通过数字化赋能法律监督,以解决以往法律监督“被动性”“碎片化”“浅层次”等问题,是一种穿透式、类案式、一体化的法律监督。以数字检察的监督过程为观察视角,发现数字检察在监督内容、数据获取、技术运用、监督程序等环节的法治边界不清,数字检察存在异化风险。数字检察法治边界之厘定是其持续稳定发展的基础。因而,在过程视角下,我们应明确,数字检察的监督内容在横向上需坚持以法律为依据,在纵向上需关注人民群众所关心的重点问题;数据获取需遵守比例原则、成本控制原则、数据安全保障原则与个人信息保护原则;技术运用中的技术选择仍需坚持成本控制原则,技术引入需履行算法备案与专家评议,技术运行应遵守技术辅助、技术透明与技术参与原则;监督程序上需秉持案件化监督、协作式监督以及事后监督等准则。

基于改进蚁群算法和共用航段的搜索救援通道规划

针对战斗搜救任务场景中,空中搜索救援等待区至跳伞区之间的往返路径规划问题,提出一种基于改进蚁群算法和共用航段的搜索救援通道规划方法。首先,针对基本蚁群算法易出现局部极值及收敛速度慢等缺点,对启发函数、状态转移策略、信息素更新策略进行了改进。然后,针对单起点多目标点的路径规划问题,提出了设置分航点以生成共用航段的搜索救援通道规划方法,并以总路径长度表征任务准备负荷量与分别规划航路进行对比。实验结果表明,在本文测试环境下,改进蚁群算法规划的路径长度分别缩减15.4%和14.2%,搜索救援通道的任务准备负荷量减少25.4%。所提出的搜索救援通道规划方法有一定的理论和应用价值。

考虑综合经济性的风光配电网储能优化配置

在配电网中配置储能系统可以有效缓解风光接入对配电网产生的影响,提升对风光的消纳能力、减少电压偏差等,而储能接入的位置和容量不同会对配电网产生不同的影响。首先分析储能建设过程中的主要费用,考虑基于分时电价下的网损成本和峰谷差收益,以年综合成本、配电网的日节点电压偏差和最小为目标,建立配电网储能选址定容模型,采用改进多目标遗传二代算法(improved multi-objective nondominated sorting genetic Ⅱ algorithm, INSGA-Ⅱ)对模型进行求解,利用改进理想点决策法(improved ideal point based decision, IIPBD)来选取最优配置方案,最后在IEEE-33节点模型中对方案进行验证。仿真结果表明:使用INSGA-Ⅱ算法进行求解时最终决策出的储能配置方案实现了成本最小,并且显著提升了电压的稳定性,验证了改进后算法的优良性和所提出的储能优化配置方案的有效性。

考虑用户偏好的停车场共享泊位分配模型

城镇化、机动化的持续快速发展催生了城市停车问题,为缓解日益严峻的停车窘境,共享停车应运而生并受到广泛关注与研究。为弥补经典共享泊位分配模型对用户停车成本刻画及用户效益评价的缺失,基于共享停车既有研究及调研数据,构建共享停车选择意愿结构方程模型以分析用户偏好,标定结果显示:模型识别出停车费用、步行距离、违停罚款、寻停时间四类停车偏好,且路径系数依次降低。将结构方程模型识别结果及路径系数作为用户停车成本建模的依据,以经营平台收益与用户停车成本的差值表示系统效益,将系统效益最大化作为优化目标,综合泊位时空间约束,提出考虑用户偏好的停车场共享泊位分配模型。设计随机生成分配方案的蒙特卡洛算法,定义平台让利程度以评价用户效益。数值算例表明:设计的蒙特卡洛算法能够有效求解模型,在模拟次数约10000次后得到系统效益最大值;考虑用户偏好的停车场共享泊位分配模型能够将用户效益提升约7.5%,为共享经营平台权衡自身收益及用户效益提供一定的理论参考。