共查询到20条相似文献，搜索用时 218 毫秒
1.
研究了一种求解作业车间调度问题的改进人工蜂群算法.在分析了蜂群算法在车间调度问题应用现状的基础上,指出了蜂群算法的优势和不足.针对蜂群算法在邻域搜索能力上的不足,利用模拟退火算法改进跟随蜂的邻域搜索过程,提高了算法搜索范围和收敛性.采用车间调度标准算例,通过仿真实验与其它算法进行比较,验证了算法的有效性和优越性. 相似文献
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分析了遗传算法和模拟算法的主要优缺点,提出一种用于求解旅行商问题（TSP）的改进遗传算法,该算法有效地将遗传算法和模拟退火算法相结合,在很大程度上缩短了算法的搜索时间;利用MATLAB对多种TSP问题进行仿真研究,实验结果证明了改进的遗传算法的有效性。 相似文献
3.
蚁群算法是一种新型高效的启发式优化算法,在解决优化组合问题特别是TSP求解问题上具有很高效率.本文在分析了蚁群算法的基本原理和工作机制的基础上,从信息素的更新改进实现对节点重复率的控制,并通过仿真实验实现相关参数的最优选择.实验证明,改进算法可以有效地减少蚂蚁行走的盲目性,提高了蚁群算法在迭代过程中更新TSP最优解的能力. 相似文献
4.
以简单TSP问题为例描述了传统蚁群算法过程,提出了其存在的问题及解决该问题的方法.提出了复杂TSP问题的定义,结合改进后的蚁群算法提出了解决复杂TSP问题的方法.通过实验表明,改进后的蚁群算法能够用于解决复杂TSP问题. 相似文献
5.
TSP（旅行商问题）是一个学术界广泛研究的问题,长期以来吸引了众多学者对其进行研究。在蚁群算法（ACA）的研究中,TSP同样起着重要的作用。首先对TSP问题和基本蚁群算法进行了介绍,然后改进了蚁群算法的状态转移概率公式和信息素更新策略,并且应用该改进蚁群算法对TSPLIB中的两个典型问题进行仿真,实验结果比较理想。 相似文献
6.
针对旅行商(traveling salesman problem,TSP)是一个NP问题,本文使用改进的人工鱼群算法(improved artificial fish swarm algorithm,AFSA)进行线路的优化.首先阐述了TSP问题基本概念,其次针对基本的人工鱼群算法分别优化:(1)使用Laplace进行种群初始化,提高种群多样性;(2)使用正弦余弦算法取代觅食行为,保证算法在全局和局部范围内具有一定的平衡性;(3)利用人工蜂群算法对每一次迭代后的个体进行筛选,保证了算法的解的质量.仿真实验中本文算法在TSP路径规划方面具有一定的效果. 相似文献
7.
TSP问题即旅游最优路线问题,是数学领域中著名问题之一.如今,把TSP用于解决物流行业中运输线路优化已成为一种新的趋向.针对TSP问题没有一种简便、统一的求解方法,提出了改进的TSP算法,即把问题转化为求解最小树和图中悬挂点的匹配问题,从而大大缩小了TSP问题解的搜索空间,降低了求解难度,得到一种改进的求解方法,解决了供应链一对多配送问题. 相似文献
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TSP问题的最优化研究及求解实例 总被引：2，自引：0，他引：2
本文首先描述了旅行商问题(简称TSP),介绍了TSP问题的发展历史,并提出了自己的观点,然后对基于模拟退火算法的神经网络求解TSP问题的具体技术线路进行了详细介绍,最后建立了一个求解TSP问题的实例模型,用C语言编制程序,给出了运行结果。 相似文献
10.
对混合蛙跳算法优化机制的进行分析,设计了一种求解TSP问题的混合蛙跳算法。针对混合蛙跳算法容易早熟的缺陷,算法首先根据种群的适应度确定初始蛙群的位置,其次设计了模因组选择青蛙的概率公式,并对模因组中最差的青蛙个体进行更新,最后,对参数的设置做了分析。针对TSP的实验结果表明,该算法在求解精度上取得了良好的效果。 相似文献
11.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
12.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
13.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
14.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
15.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
16.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
17.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献