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Concrete Physics Method for Solving NP hard Problem
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作者 Huang Wen\|qi College of Computer Science, Huazhong University of Science and Technology, Wuhan 430074,China Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing 100080, China 《Wuhan University Journal of Natural Sciences》 CAS 2001年第Z1期140-146,共7页
With a NP hard problem given, we may find a equivalent physical world. The rule of the changing of the physical states is simply the algorithm for solving the original NP hard problem .It is the most natural algorithm... With a NP hard problem given, we may find a equivalent physical world. The rule of the changing of the physical states is simply the algorithm for solving the original NP hard problem .It is the most natural algorithm for solving NP hard problems. In this paper we deal with a famous example , the well known NP hard problem——Circles Packing. It shows that our algorithm is dramatically very efficient. We are inspired that, the concrete physics algorithm will always be very efficient for NP hard problem. 展开更多
关键词 concrete physics algorithm np hard problem circles packing the rule of the changing of the physical states
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Optimal Rapid Restart of Heuristic Methods of NP Hard Problems
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作者 侯越先 王芳 《Transactions of Tianjin University》 EI CAS 2004年第2期146-148,共3页
Many heuristic search methods exhibit a remarkable variability in the time required to solve some particular problem instances. Their cost distributions are often heavy-tailed. It has been demonstrated that, in most c... Many heuristic search methods exhibit a remarkable variability in the time required to solve some particular problem instances. Their cost distributions are often heavy-tailed. It has been demonstrated that, in most cases, rapid restart (RR) method can prominently suppress the heavy-tailed nature of the instances and improve computation efficiency. However, it is usually time-consuming to check whether an algorithm on a specific instance is heavy-tailed or not. Moreover, if the heavy-tailed distribution is confirmed and the RR method is relevant, an optimal RR threshold should be chosen to facilitate the RR mechanism. In this paper, an approximate approach is proposed to quickly check whether an algorithm on a specific instance is heavy-tailed or not. The method is realized by means of calculating the maximal Lyapunov exponent of its generic running trace. Then a statistical formula to estimate the optimal RR threshold is educed. The method is based on common nonparametric estimation, e.g., Kernel estimation. Two heuristic methods are selected to verify our method. The experimental results are consistent with the theoretical consideration perfectly. 展开更多
关键词 np hard problems heavy-tailed rapid restart(RR) Lyapunov exponent optimal RR threshold
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Strong NP-Hardness of Single Machine Scheduling Problems with Variable Processing Time
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作者 周贤伟 杜文 朱健梅 《Journal of Modern Transportation》 1998年第2期78-88,共11页
In this paper, single machine scheduling problems with variable processing time is discussed according to published instances of management engineering. Processing time of a job is the product of a “coefficient' ... In this paper, single machine scheduling problems with variable processing time is discussed according to published instances of management engineering. Processing time of a job is the product of a “coefficient' of the job on position i and a “normal' processing time of the job. The criteria considered is to minimize scheduled length of all jobs. A lemma is proposed and proved. In no deadline constrained condition, the problem belongs to polynomial time algorithm. It is proved by using 3 partition that if the problem is deadline constrained, its complexity is strong NP hard. Finally, a conjuncture is proposed that is to be proved. 展开更多
关键词 single machine scheduling problem variable processing time strong np hardness.
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粮库PWSN部署中NP-Hard问题的研究 被引量:1
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作者 陈得民 张元 +1 位作者 廉飞宇 张秋闻 《河南工业大学学报(自然科学版)》 CAS 北大核心 2008年第4期6-9,19,共5页
以无线传感器网络在粮库中的应用为例,将传感器节点部署中出现未覆盖区域问题归属为NP-Hard问题.结合近似算法、Bidding协议、Voronoi diagrams等方法,对粮库PWSN部署中的NP-Hard问题进行了较深入的研究,对解决粮库无线传感器网络的覆... 以无线传感器网络在粮库中的应用为例,将传感器节点部署中出现未覆盖区域问题归属为NP-Hard问题.结合近似算法、Bidding协议、Voronoi diagrams等方法,对粮库PWSN部署中的NP-Hard问题进行了较深入的研究,对解决粮库无线传感器网络的覆盖问题提出了新思路. 展开更多
关键词 覆盖问题 PWSN nphard
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DVE场景精简的NP-Hard问题及其近似算法
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作者 陈庆 贾金原 《系统仿真学报》 CAS CSCD 北大核心 2008年第S1期21-24,共4页
高效的网格精简算法对于大规模DVE场景的实时绘制与传输均十分重要。目前已经提出了大量关于网格精简方法,但绝大多数网格优化算法都是面向实际应用的。我们却从计算机科学理论的角度出发,对这一经典问题重新进行了深入研究。首先,我们... 高效的网格精简算法对于大规模DVE场景的实时绘制与传输均十分重要。目前已经提出了大量关于网格精简方法,但绝大多数网格优化算法都是面向实际应用的。我们却从计算机科学理论的角度出发,对这一经典问题重新进行了深入研究。首先,我们发现网格精简是一个最优顶点覆盖问题,即NP-Hard问题。然后,我们又提出了一种基于贪心算法的用于网格精简的最优顶点覆盖问题的近似算法。理论推导与实验数据都说明本文所给出的近似算法有效地减少了DVE场景的网格数量,能进一步提高DVE场景数据的网络传输速度。 展开更多
关键词 虚拟现实 np-hard问题 顶点覆盖 近似算法 贪心算法 网格精简
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基于多因素分析的机场任务指派建模与仿真
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作者 田倩南 李杰 +1 位作者 李昆鹏 郭群 《运筹与管理》 CSSCI CSCD 北大核心 2024年第2期1-8,共8页
机场任务指派问题是一个复杂的组合优化问题,属于NP-hard问题。本文研究了考虑任务部分覆盖率、资格匹配度等多因素的指派问题,通过分析研究问题,建立整数规划模型,对模型进行分析并提出有效不等式,应用CPLEX优化软件对不同因素的实际... 机场任务指派问题是一个复杂的组合优化问题,属于NP-hard问题。本文研究了考虑任务部分覆盖率、资格匹配度等多因素的指派问题,通过分析研究问题,建立整数规划模型,对模型进行分析并提出有效不等式,应用CPLEX优化软件对不同因素的实际数据进行仿真测试,数值实验结果表明:1)该模型的可行性与有效性;2)对不同规模的实际数据求解发现,即使覆盖率设置高达80%,目标函数的均值依然提高9.6%;当同时考虑资格匹配度时,目标函数均值也能提高6.98%;3)对考虑不同属性因素数据的测试结果对比发现,降低任务对资格的要求对目标函数产生的影响最大,目标函数均值增加量高达27.96%,从而对任务完成率影响更直观。研究可以有效提高机场的运行效率和任务完成率,为企业实际运营决策提供科学依据。 展开更多
关键词 任务部分覆盖率 np-hard问题 整数规划模型 CPLEX优化软件
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求解最小支配集问题的禁忌遗传混合算法
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作者 吴歆韵 彭瑞 熊才权 《湖北工业大学学报》 2024年第2期17-22,共6页
将最小支配集问题转换为一系列判定问题k支配集问题,并提出一种禁忌遗传混合算法对k-DS问题进行求解。此算法将禁忌搜索算法和遗传算法两种启发式算法结合起来,互补不足。高效的邻域结构保证了算法的运行效率,禁忌策略防止算法过早陷入... 将最小支配集问题转换为一系列判定问题k支配集问题,并提出一种禁忌遗传混合算法对k-DS问题进行求解。此算法将禁忌搜索算法和遗传算法两种启发式算法结合起来,互补不足。高效的邻域结构保证了算法的运行效率,禁忌策略防止算法过早陷入局部最优陷阱,遗传算法框架进一步增强了算法的疏散性。经过与现有求解最小支配集算法的结果进行分析比较,禁忌遗传混合算法的结果较其它算法更优。 展开更多
关键词 最小支配集 np难问题 禁忌遗传混合算法 k支配集
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区块链技术中的运筹学
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作者 张玉忠 《曲阜师范大学学报(自然科学版)》 CAS 2024年第2期1-8,共8页
该文阐述了区块链技术及其在世界技术革命与当今社会发展中的意义和作用.针对区块链技术,提出了与之密切相关的组合最优化问题,证明了它们与现有的组合优化问题(如排序问题、背包问题等)之间的联系甚至等价性.同时探究了区块链技术在农... 该文阐述了区块链技术及其在世界技术革命与当今社会发展中的意义和作用.针对区块链技术,提出了与之密切相关的组合最优化问题,证明了它们与现有的组合优化问题(如排序问题、背包问题等)之间的联系甚至等价性.同时探究了区块链技术在农业机械调度、能源调度等领域的最优化问题中的应用. 展开更多
关键词 区块链技术 排序 近似算法 计算复杂性 np-难问题
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基于NP证据加密的可撤销广播加密方案构建
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作者 郭韧 陈福集 程小刚 《电子科技大学学报》 EI CAS CSCD 北大核心 2016年第6期969-973,共5页
NP(non-deterministic polynomial)证据加密(witness encryption,WE)是近来提出的一种新型的没有密钥生成过程的加密方案,可以用来构建许多其他的密码系统如公开密钥加密、IBE(identity based encryption)、ABE(attribute based encrypt... NP(non-deterministic polynomial)证据加密(witness encryption,WE)是近来提出的一种新型的没有密钥生成过程的加密方案,可以用来构建许多其他的密码系统如公开密钥加密、IBE(identity based encryption)、ABE(attribute based encryption)等。该文提出WE的一种新应用:用WE构建可撤销广播加密系统,并且所构建的广播加密方案能支持简单的成员重加入功能(如付费电视);在构建的过程中指出以前的WE安全性定义不够严格,对原WE安全性定义进行了增强,并基于原WE方案和子集成员分辨难题、ROM(random oracle model)模型提出了一个新方案。 展开更多
关键词 广播加密 子集成员分辨难题 成员撤销 np证据加密
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Solving the Traveling Salesman Problem Using Hydrological Cycle Algorithm 被引量:1
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作者 Ahmad Wedyan Jacqueline Whalley Ajit Narayanan 《American Journal of Operations Research》 2018年第3期133-166,共34页
In this paper, a recently developed nature-inspired optimization algorithm called the hydrological cycle algorithm (HCA) is evaluated on the traveling salesman problem (TSP). The HCA is based on the continuous movemen... In this paper, a recently developed nature-inspired optimization algorithm called the hydrological cycle algorithm (HCA) is evaluated on the traveling salesman problem (TSP). The HCA is based on the continuous movement of water drops in the natural hydrological cycle. The HCA performance is tested on various geometric structures and standard benchmarks instances. The HCA has successfully solved TSPs and obtained the optimal solution for 20 of 24 benchmarked instances, and near-optimal for the rest. The obtained results illustrate the efficiency of using HCA for solving discrete domain optimization problems. The solution quality and number of iterations were compared with those of other metaheuristic algorithms. The comparisons demonstrate the effectiveness of the HCA. 展开更多
关键词 WATER-BASED OPTIMIZATION Algorithms Nature-Inspired Computing DISCRETE OPTIMIZATION problemS np-hard problemS
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A Class of Single Machine Scheduling Problems with Variable Processing Time
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作者 周荷芳 周贤伟 《Journal of Modern Transportation》 2001年第1期93-100,共8页
In this paper, single machine scheduling problems with variable processing time are raised. The criterions of the problem considered are minimizing scheduling length of all jobs, flow time and number of tardy jobs and... In this paper, single machine scheduling problems with variable processing time are raised. The criterions of the problem considered are minimizing scheduling length of all jobs, flow time and number of tardy jobs and so on. The complexity of the problem is determined. [WT5HZ] 展开更多
关键词 single machine scheduling problem np-hard variable processing time complexity theory
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Improved Parallel Three-List Algorithm for the Knapsack Problem without Memory Conflicts
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作者 潘军 李肯立 李庆华 《Journal of Southwest Jiaotong University(English Edition)》 2006年第1期7-14,共8页
Based on the two-list algorithm and the parallel three-list algorithm, an improved parallel three-list algorithm for knapsack problem is proposed, in which the method of divide and conquer, and parallel merging withou... Based on the two-list algorithm and the parallel three-list algorithm, an improved parallel three-list algorithm for knapsack problem is proposed, in which the method of divide and conquer, and parallel merging without memory conflicts are adopted. To find a solution for the n-element knapsack problem, the proposed algorithm needs O(2^3n/8) time when O(2^3n/8) shared memory units and O(2^n/4) processors are available. The comparisons between the proposed algorithm and 10 existing algorithms show that the improved parallel three-fist algorithm is the first exclusive-read exclusive-write (EREW) parallel algorithm that can solve the knapsack instances in less than O(2^n/2) time when the available hardware resource is smaller than O(2^n/2) , and hence is an improved result over the past researches. 展开更多
关键词 Knapsack problem np-hard Parallel algorithm Memory conflicts hardware-time tradeoff
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Number of Tardy Jobs of Single Machine Scheduling Problem with Variable Processing Time
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作者 朱健梅 《Journal of Modern Transportation》 1999年第1期88-95,共8页
The number of tardy jobs of the single machine scheduling problem with a variable processing time is studied in accordance with the published instances of traffic transportation management engineering. It is proved ... The number of tardy jobs of the single machine scheduling problem with a variable processing time is studied in accordance with the published instances of traffic transportation management engineering. It is proved by 3 partition problem that if the problem is of ready time and common deadline constrained, its complexity is NP hard in the strong sense. Finally, a polynomial algorithm for solving unit processing time and common deadline problems is proposed. 展开更多
关键词 NUMBER of tardy JOBS single machine scheduling problem VARIABLE processing time STRONG np hardNESS algorithm.
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Sea Turtle Foraging Optimization-Based Controller Placement with Blockchain-Assisted Intrusion Detection in Software-Defined Networks
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作者 Sultan Alkhliwi 《Computers, Materials & Continua》 SCIE EI 2023年第6期4735-4752,共18页
Software-defined networking(SDN)algorithms are gaining increas-ing interest and are making networks flexible and agile.The basic idea of SDN is to move the control planes to more than one server’s named controllers a... Software-defined networking(SDN)algorithms are gaining increas-ing interest and are making networks flexible and agile.The basic idea of SDN is to move the control planes to more than one server’s named controllers and limit the data planes to numerous sending network components,enabling flexible and dynamic network management.A distinctive characteristic of SDN is that it can logically centralize the control plane by utilizing many physical controllers.The deployment of the controller—that is,the controller placement problem(CPP)—becomes a vital model challenge.Through the advancements of blockchain technology,data integrity between nodes can be enhanced with no requirement for a trusted third party.Using the lat-est developments in blockchain technology,this article designs a novel sea turtle foraging optimization algorithm for the controller placement problem(STFOA-CPP)with blockchain-based intrusion detection in an SDN environ-ment.The major intention of the STFOA-CPP technique is the maximization of lifetime,network connectivity,and load balancing with the minimization of latency.In addition,the STFOA-CPP technique is based on the sea turtles’food-searching characteristics of tracking the odour path of dimethyl sulphide(DMS)released from food sources.Moreover,the presented STFOA-CPP technique can adapt with the controller’s count mandated and the shift to controller mapping to variable network traffic.Finally,the blockchain can inspect the data integrity,determine significantly malicious input,and improve the robust nature of developing a trust relationship between sev-eral nodes in the SDN.To demonstrate the improved performance of the STFOA-CPP algorithm,a wide-ranging experimental analysis was carried out.The extensive comparison study highlighted the improved outcomes of the STFOA-CPP technique over other recent approaches. 展开更多
关键词 Software-defined networking np hard problem metaheuristics controller placement problem objective function
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求解0-1背包问题的牵制平衡算法
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作者 罗亚波 滕红玺 《工业工程》 北大核心 2023年第3期116-123,共8页
为扩充对于经典NP-hard问题中的0-1背包问题的求解方法,模拟生态系统中各物种间相互依存、牵制,最终达到动态平衡的自然机制,提出一种新型仿生算法:牵制平衡算法。算法以种群规模描述设计变量,以牵制关系为优化驱动力,以系统达到稳态为... 为扩充对于经典NP-hard问题中的0-1背包问题的求解方法,模拟生态系统中各物种间相互依存、牵制,最终达到动态平衡的自然机制,提出一种新型仿生算法:牵制平衡算法。算法以种群规模描述设计变量,以牵制关系为优化驱动力,以系统达到稳态为优化目标,设计了自成长函数、牵制函数、成长函数用以描述设计变量的变化规律,促进解的寻优进程。将牵制平衡算法对于10个不同规模0-1背包问题的求解结果与近年来文献数据进行对比,结果显示算法在8个不同规模的问题中能获得当前已知最优解,验证了牵制平衡算法的收敛性与求解性能,表明算法对于0-1背包问题的求解具有有效性和竞争力。 展开更多
关键词 0-1背包问题 np-hard问题 仿生算法 元启发式算法 生态平衡机制
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解决图着色问题的膜进化算法
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作者 郭平 郭宾 《重庆大学学报》 CAS CSCD 北大核心 2023年第7期23-35,共13页
图着色问题是图论中比较热门的NP难问题之一。针对该问题,有许多启发式求解算法,但都存在求解的质量不高,计算时间较长等问题。近些年提出的膜进化算法,在处理NP难问题中展现出了独特的优势。基于膜进化算法框架,提出了解决图着色问题... 图着色问题是图论中比较热门的NP难问题之一。针对该问题,有许多启发式求解算法,但都存在求解的质量不高,计算时间较长等问题。近些年提出的膜进化算法,在处理NP难问题中展现出了独特的优势。基于膜进化算法框架,提出了解决图着色问题的膜进化算法,把图着色问题和膜结合,设计了复制、融合、分裂、溶解、融合分裂、禁忌搜索6种膜进化算子。这些算子在演变的过程中使膜和膜结构发生进化,从而找到更优解,最后求得解决方案。在DIMACS的40个挑战数据集上面进行了实验,与3个最新的图着色算法比较的结果表明:在保证解的质量的情况下,文中提出的膜进化算法能有效降低求解的时间,其中有58%的实例占优。 展开更多
关键词 图论 组合优化 np难问题 图着色问题 膜进化算法
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An Efficient Proximal Point Algorithm for Unweighted Max-Min Dispersion Problem
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作者 Siqi Tao 《Advances in Pure Mathematics》 2018年第4期400-407,共8页
In this paper, we first reformulate the max-min dispersion problem as a saddle-point problem. Specifically, we introduce an auxiliary problem whose optimum value gives an upper bound on that of the original problem. T... In this paper, we first reformulate the max-min dispersion problem as a saddle-point problem. Specifically, we introduce an auxiliary problem whose optimum value gives an upper bound on that of the original problem. Then we propose the saddle-point problem to be solved by an adaptive custom proximal point algorithm. Numerical results show that the proposed algorithm is efficient. 展开更多
关键词 Maximum Weighted DISPERSION problem Adaptive CUSTOM PROXIMAL Point Al-gorithm np-hard
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基于半监督谱聚类的最优主动解列断面搜索 被引量:15
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作者 杨健 唐飞 +3 位作者 廖清芬 王乙斐 陈恩泽 刘福锁 《电网技术》 EI CSCD 北大核心 2015年第1期242-249,共8页
主动解列最优断面搜索是依据广域测量信息,在大电网遭受大扰动失步崩溃之前,依据实时工况和运行方式,快速准确求取电力孤岛划分的紧急策略。然而,在实际大系统的求解中,计算复杂度呈几何指数增长,是一个NP难题。提出了一种半监督谱聚类... 主动解列最优断面搜索是依据广域测量信息,在大电网遭受大扰动失步崩溃之前,依据实时工况和运行方式,快速准确求取电力孤岛划分的紧急策略。然而,在实际大系统的求解中,计算复杂度呈几何指数增长,是一个NP难题。提出了一种半监督谱聚类算法,首先采用最小复合有功潮流冲击的目标函数和机组同调/分离等相关约束构建详细解列断面搜索模型,然后将最优断面搜索的优化求解过程,映射为约束谱聚类对静态图分割的松弛解求取过程,最后通过改进的PAM聚类算法选择最优主动解列断面。上述过程,在不丢失全网信息前提下,降低了时间复杂度,IEEE 118标准算例和四川电网实际系统的仿真验证,证明了该算法的正确性、有效性和快速性。 展开更多
关键词 主动解列 np难题 半监督谱聚类 电气距离 解列断面
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旋转锥体空间中圆柱体群的布局优化 被引量:8
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作者 滕弘飞 刘义军 +2 位作者 葛文海 孙大新 钟万勰 《计算机学报》 EI CSCD 北大核心 1993年第7期519-525,共7页
旋转圆锥体空间中不等圆柱体群的布局为人造卫星再入舱布局的简化模型,属带动力性能约束的Packing优化问题,具有NP难度。本文提出了模式迭换法,用以构造布局拓扑模式,形成初始布局方案;推荐了在此初始布局方案下进行布局寻优的算法;给... 旋转圆锥体空间中不等圆柱体群的布局为人造卫星再入舱布局的简化模型,属带动力性能约束的Packing优化问题,具有NP难度。本文提出了模式迭换法,用以构造布局拓扑模式,形成初始布局方案;推荐了在此初始布局方案下进行布局寻优的算法;给出了缓解“组合爆炸”的技巧和算例验证。此类问题具有广阔的工程应用前景。 展开更多
关键词 旋转圆锥体空间 动力装填 布局优化 布局拓扑 启发式算法 np-完全问题 人造卫星 再入舱
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基于动态规划法求解动态0-1背包问题 被引量:15
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作者 贺毅朝 田海燕 +2 位作者 张新禄 王志威 高锁刚 《计算机科学》 CSCD 北大核心 2012年第7期237-241,共5页
随机时变背包问题(RTVKP)是一种动态组合优化问题,也是一种典型的NP-hard问题。由于RTVKP问题中物品的价值、重量和背包载重均是动态变化的,导致问题的求解非常困难。在动态规划法基础上,提出了一种求解背包载重随机变化的RTVKP问题的... 随机时变背包问题(RTVKP)是一种动态组合优化问题,也是一种典型的NP-hard问题。由于RTVKP问题中物品的价值、重量和背包载重均是动态变化的,导致问题的求解非常困难。在动态规划法基础上,提出了一种求解背包载重随机变化的RTVKP问题的确定性算法,分析了其复杂度和成功求解需要满足的条件。对两个大规模实例的计算表明,该算法是求解RTVKP问题的一种高效算法。 展开更多
关键词 np-难问题 0-1背包问题 动态优化 时变背包问题 动态规划法
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