车辆调度问题的全局—局部最优信息比粒子群算法研究

文章提出了一种新的改进标准粒子群算法即全局—局部最优信息比粒子群算法。该算法与标准粒子群算法和全局—局部最优最小值粒子群优化算法作了比较,仿真实验结果表明,该算法在收敛速度、解的质量和鲁棒性上都表现出了较优的性能,是求解车辆调度问题的一种较好方法。     

混合粒子群优化算法在CDMA系统多用户检测中的应用

针对粒子群优化算法易早熟的问题,提出了一种混合粒子群优化算法(HPSO)。首先在算法中采用惯性权重的分段递减策略,以提高算法的全局搜索能力;然后在算法后期,引入拉伸技术剔除比局部极值大的点,缩小搜索空间,使算法能及时跳出局部最优从而加速收敛,最后提出了基于HPSO算法的多用户检测器。仿真结果表明在信噪比相同的条件下,该多用户检测器的误码率和抗远近效应性能更接近于最佳多用户检测器,有效解决了码分多址通信系统中的多址干扰问题。     

一种新的基于粒子群密度的聚类算法

提出了一种新的粒子群密度聚类算法和对粒子群的初始化方法。该算法具有传统粒子群算法寻找最优解的特点,同时从密度的角度考虑了数据总体的分布,增强了寻找局部最优解的能力,并通过对粒子群的初始化加快了粒子群的收敛速度,得到了更好的聚类效果。对仿真数据和IRIS真实数据的实验结果证明,该算法聚类效果优于传统粒子群聚类算法和K均值算法。     

基于粒子群优化的数字波束形成算法

波束形成的加权系数求解是一个优化过程,现有算法大多经过多次迭代,计算量大,实现复杂。为降低波束形成算法复杂度,将粒子群优化原理应用于数字波束形成中,提出了基于粒子群优化的自适应数字波束形成算法。该算法将每一组权值作为一个粒子,将阵列加权和的输出信号与干扰噪声比(SINR)作为适应度函数,通过比较各个粒子的适应度值,进行迭代搜索得到最优解。该算法可使天线阵在主波束对准有用信号,同时能有效抑制两个以上的干扰,且对阵列通道误差有较好的稳健性。计算机仿真验证了算法的有效性。     

基于冯诺依曼结构的粒子群算法在项目资源均衡中的应用

针对项目管理中工期固定--资源均衡问题,设计了基于冯诺依受拓扑结构的粒子群算法局部模型,应用子资源均衡评价函数.通过对文献[5]中算例的计算分析,该模型比全局模型的粒子群算法在寻优率上提高了135%,对文献[6]中的资源均衡问题进行优化计算,比较了冯诺依曼结构与标准全局结构的性能,验证了该模型应用在资源均衡中的更好的性能.     

基于改进粒子群算法的卫星数传任务调度

建立了卫星数传任务调度模型,讨论了约束条件和调度目标.设计了一种自适应规模粒子群算法,该算法采用基于星地可视时间窗的十进制编码,各粒子编码表示不同可视时间窗内可分配数传作业的概率.在迭代过程中根据粒子群整体差异度动态调整种群规模,删除部分差异度小的粒子,同时增加新粒子以保证种群多样性.通过实例仿真表明,自适应规模粒子群算法在解决卫星数传任务调度问题中具有调度结果优、收敛速度快等优点,并对算法的控制参数取值进行了分析.     

基于迭代优化度与直线搜索的改进粒子群算法

现有粒子群算法无论是在算法运行的前期还是后期,现有的改进方法都是以适应度值来作为评价粒子优劣的唯一标准,本文根据挖掘有潜力粒子的思想,提出迭代优化度概念来刻画粒子的潜力,并对于潜力较大的粒子采用直线搜索的策略来进行搜索,这样就避免所有的粒子均参考适应度值优秀的粒子运动,提高了算法效率,保持了潜力大的粒子的独立性。将改进粒子群算法用2个经典的检验函数进行对比检验,结果表明提出的改进粒子群算法能大幅度增强摆脱局部最优解的能力,有效地改善寻优性能。     

基于改进粒子滤波的GPS接收机自主完好性监测算法

针对基本粒子滤波重采样过程中粒子权值退化和多样性丧失的问题,将遗传算法引入基于神经网络的权值调整粒子滤波算法中,结合了遗传算法全局寻优的收敛性与神经网络局部寻优的快速性优点。将提出的算法与对数似然比方法结合用于GPS接收机自主完好性监测,通过建立一致性检验统计量实现对故障卫星的检测与隔离。通过采集实测数据进行验证,结果表明：该算法可以成功检测和隔离故障卫星,其性能优于基于基本粒子滤波的接收机自主完好性监测,验证了该算法应用于GPS接收机自主完好性监测的可行性和有效性。     

无人机扩频遥控链路Rake接收机设计

针对无人机起降阶段多径效应会引起遥控误码率性能下降的问题,提出了一种基于导频辅助的Rake抗多径算法。该算法通过在传输帧中插入导频符号和在遥控接收机中增加Rake抗多径模块的方式,使无人机遥控链路在多径信道下的误码率性能得到了显著改善。在高斯、莱斯、瑞利等信道条件下对算法进行了仿真,结果表明,该算法能够将无人机起降阶段的遥控误码率提高2～3个量级。实测数据进一步验证了该算法抗多径性能的有效性。     

基于改进K-means聚类和量子粒子群算法的多航迹规划

针对在复杂环境下需要通过多航迹规划以实现武器协同的问题,利用排挤机制产生K-means聚类的初始聚类中心,并将改进K-means聚类与量子粒子群算法（QPSO）相结合应用于无人机的三维多航迹规划。改进算法解决了K-means聚类易陷入局部最优、聚类准确率低的问题。根据产生的初始聚类中心,将粒子划分成多个子种群,利用QPSO算法对每个子种群进行优化,使得每个子种群可以产生一条可行航迹。仿真分析证明了改进算法可以有效保证子种群之间的多样性,生成较为分散的多条可行航迹。     

Brown＇s Blossom in Britain-China

The overall strategic relationship between U.K. and China is ＂better than ever＂, China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future.     

Challenge and Opportunity Go Hand in Hand——What Global Economic Agitation Brings to the China's Economy?

Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit.     

Sinosteel：Extraordinary Moves in Industry Chess

Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service ＆ trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,＂In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves.＂     

Walk Through Unusual Five Years—— An Exhibitor＇s Canton Fair Course

When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years＇ experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year.     

Jean-Pierre Duprieu： Willing to Be A Legate of Sino-French Business

Estaing, former French president, Valery Giscard d＇Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself＂French Confucian＂, then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually ＂Partners＂.     

China''''s Stock Market Wave

The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy.     

Trade Promotion from Neighborhood

If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning.＂ You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization （JETRO）. JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China＇s Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING.     

Auto Parts Market Potential Coming into Surface

Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship,     

China's Auto Industry Steps Forward

Last year,the volume of China's auto trade reached US$66.878 bil- lion,of which imports accounted for US$25.982 billion,a year-on- year increase of 24.45 percent;while ex- ports totaled US$40.896 billion,growing by 45.31 percent.The China Association of Automobile Manufacturers(CAAM) predicts that the number of autos sold in 2008 will break the 1 million barrier for the first time in history,representing an increase of about 20 percent.     

Domino Effect on Electricity and Coal Prices

In the middle of last December, the key purchase contracts for coal used in power generation in 2008 were signed, reflecting a demand for more than 1.085 billion tons. It is important to note that the country＇s five biggest power producers, China Huaneng Group, China Guodian Corporation, China Power Investment Corporation, China Huadian Corporation and China Datang Corporation, had settled on the prices on their purchase contracts, and they are expected to consume 290 million tons of coal for generating electricity,