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《科技通报》2015,(12)
研究云计算环境下的大型智能交通调度问题。云计算环境下的大型智能交通网络在进行车辆调度的过程中,由于运算量过于庞大,造成交通调度效率降低,运输成本增加。利用传统的遗传算法进行交通调度的过程中,无法避免由于早熟和停滞的现象造成的影响,难以搜索到最优交通路线,从而降低了交通调度的效率。为此,提出一种基于神经网络算法的大型智能交通调度方法,根据约束条件建立神经网络模型,确定各神经层中神经元的输入与输出关系式,从而得到基于神经网络算法的最优交通调度方案。实验结果表明,利用改进算法进行云计算环境下的大型智能交通调度,缩短了交通调度完成时间,提高了交通调度效率,效果令人满意。 相似文献
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针对不确定对象的最近邻反向查询没有考虑多种特征类型而不能满足复杂的应用场景的问题,提出了基于限界剪枝和概率剪枝的多类型概率最近邻反向(Multiple types probabilistic nearest neighbor reverse,MTPNNR)查询算法。限界剪枝利用最小耗费来修剪不可行解或者非最优解对象;概率剪枝是基于概率分布模型和不确定对象分解的策略,根据概率各个阀值和剪枝的深度来控制需要剪枝的精度。与原始基于定义的算法相比较,MTPNNR查询算法在CPU资源开销方面有比较大的优势,能够完成在较大数据复杂等环境下的查询。基于实验结果显示,MTPNNR算法在离散型的数据集和不确定数据集上有比较好的查询效率。 相似文献
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传统车辆调度模型针对复杂的路况和复杂的车辆流动信息,存在调度时间长、难以提供实时调度时间的缺点,从而造成模型中前后级调度信号失联、调度算法冲突,效率不高的问题.本文提出一种改进遗传算法交通调度平台大规模拥堵优化调度方案.通过对算法编码过程进行合理的优化,加入针对多调度中心的约束条件防止算法陷入早熟,通过不同的分析角度,分别建立的回路形式和时间优化控制形式对车辆进行合理的调度.仿真结果显示,改进后的算法有效地降低了车辆平均延误时间,提高了交通运行效率. 相似文献
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交通网络节点和实体不断增长,对交通智能预测和控制提出更高的要求。传统方法采用智能神经网络PID控制方法进行交通控制,在交通并行负载无规则增长下,系统输出不能有效跟踪参考轨线,导致负载调度和控制效果不好。结合智能蜂群仿生算法和粗糙集理论,提出一种基于蜂群引导粗糙集前馈补偿动态博弈论的交通智能预测控制算法,建立一种基于粗糙集理论的前馈补偿动态博弈数学模型,控制参数在动态博弈中实现自适应寻优,迭代修正预测值的不确定性,预测模型收敛到最优解,克服实体无规则增长导致预测控制品质不好的问题。仿真实验表明,采用该控制方法对交通网络进行预测控制,能适用于大规模并行交通网络调度与预测控制,提高控制的鲁棒性。 相似文献
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本文研究了智能交通车辆监控调度系统中的车辆路径问题,并对现有A*算法进行了改进和应用。 相似文献
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《科技通报》2016,(8)
恐袭威胁具有突发性和非规律性的特点,且通常发生在人群聚集区,增大了该区域交通调度的难度,传统的调度方法主要针对静态场景进行调度,在发生恐袭威胁时,不能兼顾车辆调度的效率及能耗问题,调度消耗过大,不能满足实际的调度需求。提出基于禁忌搜索算法与遗传算法相融合的恐袭威胁下的最优交通调度方法。以恐袭威胁区域交通调度距离最小、能耗最小、时间最短为目标,建立相应的交通调度模型,采用禁忌搜索算法与遗传算法相融合的调度方法,对模型进行最优解搜索,获取最优调度方案,实现基于大数据分析的恐袭威胁下的最优交通调度。实验结果表明,采用改进算法进行恐袭威胁下的交通调度能够有效的推算出车流,提高调度效率、降低分析成本,具有极高的应用价值。 相似文献
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多源数据辨识系统广泛应用在机载数据辨识控制、大型机械设备故障诊断和云存储系统数据库集成等领域。对多源数据的辨识系统并行查询和数据调度中,因数据的静态非线性测量过程影响了查询效益,需要对辨识系统并行查询链路进行扩展。提出一种基于振幅调节Fourier变换边缘逆理论的辨识系统并行查询扩展算法。进行多源数据辨识系统基本构造和模型设计,提取查询特征信息,采用RBF神经网络系统进行多源数据输入自适应学习,构建神经网络辨识系统的边缘逆向量,采用边缘逆理论进行振幅调节Fourier变换实现多源查询数据的状态重组,实现查询链路扩展设计改进。仿真结果表明,该算法提高了辨识系统的查询通道的链路相位,多源数据调度的时间成本及空间成本大幅降低,加速比提高,算法将在系统状态识别、机械故障智能诊断等领域具有较高的应用价值。 相似文献
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《科技通报》2015,(10)
恶劣天气的公路交通极易瘫痪,设计公路交通优化调度模型,提高公路交通网络的稳定性和抗毁坏性。传统的公路交通调度模型采用并行微观矢量等价加权结构,各重点路段和路口节点不能有效区别评价,调度效果不好。提出一种基于多维矢量线性规划的恶劣天气下的公路交通有效调度模型。进行恶劣天气下的交通路网信息采集,构建PID神经网络路网模型,路网模型采用一个5元组表示,提取制约交通拥堵的关键信息。设计恶劣天气下的交通拥塞检测算法,根据多维矢量线性规划可得单位路径行程时间下的拥塞状态联合分布,计算最佳适应度值,实现交通优化调度。仿真结果表明,采用该模型进行公路交通拥塞程度检测和调度,检测精度较高,能准确反映公路交通的实时状态信息,通过有效调度能大幅度提供公路交通的通行效率,应用价值较高。 相似文献
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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
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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
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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
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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
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《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
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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
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《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
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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
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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
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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