共查询到20条相似文献，搜索用时 62 毫秒
1.
2.
《科技通报》2016,(4)
通过对网络流量的准确预测提高对网络的调控和监测水平,避免网络拥堵,确保网络畅通。传统的网络流量预测算法采用粒子群算法,在处理大规模的流量数据时,容易导致信息发散和易陷入局部极值点,流量预测准确度不高。提出一种基于多标记学习混合差分粒子群进化的网络流量预测算法。构建多分簇的无线网络流量数据传输模型,对网络流量进行时间序列分析,采用粒子群优化算法分别比较网络信息流中的频率波动是否相同,对相同的进行合并,基于自回归移动平均算法,进行粒子群信息链特征优选准则设计,采用多标记学习混合差分粒子群进化算法,把网络流量数据嵌入到内核空间的超球体中,进行离线阶段的网络流量预测优化。仿真结果表明,该算法对网络流量预测的精度较高,误差减少,具有较好的应用价值。 相似文献
3.
详细分析了遗传算法的原理,并且根据电子商务谈判模型系统的实际,进行种群的编码,给出相应的适应度函数.遗传算法收敛速度慢且性能不稳定,基于粒子群子代个体产生趋于最优个体的思想对遗传算法进行改进,设计出适合粒子群算法的交叉变异概率公式.在针对塑料颗粒的商务谈判中,应用这两种算法模型,结果表明基于粒子群改进的算法比遗传算法更能及时提供谈判解,节省了商务谈判的时间,提高了商务谈判的效率. 相似文献
4.
5.
6.
基于包络特征的网络流量预测阈值调控算法 总被引：1，自引：0，他引：1
《科技通报》2015,(10)
对网络流量序列的准确预测的基础是进行流量判决门限阈值的合理调控,为了提高网络流量预测的精度,进行阈值调控优化设计。传统方法采用流量序列调频估计的方法进行阈值调控,算法不能准确估计流量序列的包络特征,预测精度不好。提出一种基于包络特征的网络流量预测阈值调控算法。通过不同类型的网络设备进行流量采集终端联网构建,采用自相关特征奇异分解对流量序列进行线性特征叠加运算,构建网络流量预测的时间序列模型。采用统计学数学方法对流量序列的延迟时间互信息进行阈值调控自适应建模,提取流量序列的包络特征。实现对网络流量预测的阈值调控,提高预测精度。仿真实验表明,该算法能实现对流量预测阈值的自适应调控,预测精度较传统方法提高37%,性能优越于传统算法。 相似文献
7.
对内容中心网络的域间流量监测是未来互联网架构和网络安全监护的重要内容,通过域间流量监测,防止网络拥堵和不稳,提供网络性能,同时缩减网络冗余流量。传统方法中,对域间流量的预测采用双谱分析的方法进行特征提取,实现对局域网流量的预测,算法受到短时缓冲流量的非线性特征的影响,性能不好。提出一种基于鱼群信息链特征优选的域间流量预测算法,进行网络流量信号模型分析,构建流量监护数据样本驱动空间,进行鱼群信息链特征优选系统模型与数据预处理,得到域间流量为一阶空间权矩阵,域间网络流量信息数据表示为一个方阵,实现基于鱼群信息链特征优选的域间流量预测算法的改进。实验得出,采用该算法,在较低的信噪比下,仍然具有较高的预测精度,域间流量估计误差较低,性能较优。 相似文献
8.
《科技通报》2015,(10)
设计网络流量预测数学模型,实现对网络流量的准确预测和评估。传统的流量预测算法采用包络特征子空间聚类的流量序列分析方法,对随机大数据网络流的聚类和预测效果不好。提出一种随机阵列向量模型的流量预测算法。首先进行了网络流量预测的时间序列模型构建,采用平均互信息算法和伪最近邻点法求解最优化网络流量序列重组空间异构参数,得到一个高密度流量数据分形区域,创建流量序列的概率分布曲线,在随机阵列相空间中形成新的映射采用统计学数学方法对流量序列的随机分布特征进行分布式计算,随机阵列向量模型构建方法进行流量预测算法改进。仿真结果表明,采用该算法进行流量预测,能有效提高预测精度,具有较好的流量特征分析能力,性能优越。 相似文献
9.
为了解决油气水三相流分相流量测量难题,将混沌引入粒子群法,提出了混沌粒子群算法和最小二乘支持向量机结合的软测量模型。基本思路是:利用混沌运动的遍历性,产生大量初始群体,从中择优出初始群体;对当前粒子个体产生混沌扰动,以使解跳出局部极值区间。最后将该方法应用到油气水三相流油流量测量中。实验结果表明,该方法比遗传算法具有更高的预测精度。 相似文献
10.
粒子群优化算法已越来越广泛的应用于求解优化问题,它简单实用且对一些复杂问题也能得到不错的结果,但它收敛速度慢且容易陷入局部最优值。多种群粒子群分层进化优化算法让粒子分层进化,对于具有不同适应度值的粒子采取不同的进化措施,提高了算法的收敛速度和精度。 相似文献
11.
《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
12.
《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
13.
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
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.
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
17.
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
18.
Prof. SUN Changpu from the CAS Institute of Theoretical Physics coworkers from University of Basel in Switzerland have worked out a way - at least in theory - to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams is similar to the famous Stern-Gerlach effect whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states 《中国科学院院刊(英文版)》2008,22(1):23-23
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）. 相似文献
19.
Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
20.
Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献