一种基于UAV的无人海岛监控网络数据收集策略

针对传统的最小跳路由无线传感器网络（WSN）在数据汇聚上较高的能量开销问题，提出了一种基于无人机(UAV)数据收集的动态分簇算法,其主要思想是利用节点剩余能量来确定那些节点可以当选簇首,同时利用节点坐标位置和设定地分簇半径来划分簇的大小。该算法的优势是能最大程度地均衡每个传感器节点的能量，使整体的节点剩余的能量维持在同一水平。为了提高数据收集的效率，采用蚁群算法规划了无人机数据收集的最短路径。仿真结果表明，与相同的分簇算法下传统的最小跳路由无线传感器网络相比，所提出的基于无人机的无线传感器网络（UAV-WSN）在能量利用率和生命周期方面分别提升了15%和25%，并且以上两种网络的能量利用率高达70%。     

无线传感器网络能量高效混合MAC算法

针对无线传感器网络MAC协议中存在的能耗问题,提出了能量高 效的无线传感器网络混合MAC（EEH-MAC）算法,采用基于TDMA机制的时槽系数动态调整簇内 节点的时槽大小来降低数据的传输时延;同时,对部分不需要数据传输的节点不分配时槽来 减少能耗;按簇内节点剩余能量系数形成时槽分配顺序来减少状态转换的能耗;在簇头之间 采用CSMA/CA机制的随机分配策略进行通信。仿真结果表明,EEH-MAC协议能有效减少能耗并 延长网络生命周期。     

无线Ad Hoc网络中基于活跃节点数预测的时隙ALOHA算法

针对采用时隙ALOHA算法的无线Ad Hoc网络,考虑数据包到达的动态性与数据包传输的随机性,以最大化吞吐量为目标,同时满足数据队列稳定性,构建了关于接纳控制与竞争接入的随机优化问题。由于在时隙ALOHA算法中数据包传输的最优概率取决于无线Ad Hoc网络中数据队列非空的活跃节点数,提出了一种基于活跃节点数预测的时隙ALOHA算法。该算法要求无线Ad Hoc网络中的所有发送节点实时地侦听通信信道的忙闲状态,计算基于信道状态的活跃节点数条件期望,从而动态地预测无线Ad Hoc网络在不同时刻的活跃节点数,达到网络节点依据局部网络状态信息自适应地优化数据包传输概率的目的。仿真结果表明,所提算法能够有效估计无线Ad Hoc网络在每个时隙的活跃节点数,从而显著提升网络吞吐量并且降低数据包的平均排队时延。     

太阳能无线传感器网络节点传输功率策略优化

针对配备太阳能采集设备的无线传感器网络节点，以如何合理使用采集到的能量使得时间期限内点对点传输的数据量最大为优化目的，结合必要的约束条件（能量获取电池只有有限的能量存储能力以及能量因果关系），建立了数据传输的能量通道优化模型，通过能量通道策略优化算法得到了最优传输功率策略。与当前普遍使用的能量即到即用方法进行了性能对比，仿真发现系统累积传输了更多的数据量，性能提升明显。在此基础上，考虑了实际太阳能获取量与预测值的偏差，提出了改进的能量通道算法，使得其更加适应于实际场景中。     

信息中心网络中基于节点缓存命中贡献率的缓存替换方案

信息中心网络（CCN）是一种全新的网络架构，其显著的特点是处处缓存，合理的内容缓存部署能够显著提高网络传输效率。缓存替换策略是缓存管理中的重要组成部分，合理地进行缓存内容的替换，成为影响网络整体性能的关键。考虑到内容自身的特性，设计了一种基于节点缓存命中贡献率的贪婪双倍命中（GDH）缓存替换方案。该方案综合考虑了内容的请求次数、传输代价、缓存代价，设计全新的多目标价值函数，用于评估内容的缓存价值，当缓存空间不足时，替换掉价值最小的内容，实现节点缓存内容价值的最大化。仿真结果表明，该替换算法提高了节点的命中率，降低了获取内容的平均跳数。     

车联网中交通安全消息动态优先调度机制

车联网中两类交通安全消息共享有限控制信道带宽，在消息突发状态下无法保证事件触发消息的传播性能，导致预警失效。基于差异化的消息传播性能需求提出了一种动态优先级区分的调度机制，按事件优先级分别进行队列管理，赋予事件触发消息优先权，通过设置优先级调度阈值实现对事件触发消息的动态调度。当优先队列长度高于阈值时，其抢占调度时隙。当队列长度低于阈值一半，退出抢占过程，恢复非抢占优先调度方法。仿真显示，所提调度机制能够减小事件触发消息的端到端时延约1.3 ms，提高周期性消息的公平性约0.22。     

SWAN模型速率控制模块性能分析及改进

SWAN是Ad Hoe网络中的一种无状态网络协议，利用分布式控制算法来传递分类服务。这种QoS模型把数据业务分为两类进行不同处理，即对尽力而为的UDP和TCP业务采用速率控制的策略而对实时的UDP业务采用基于源节点的接纳控制策略。本文修改了SWAN模型的速率控制模块，引入队列调度机制，对从上层来的尽力而为数据包进行排队、调度，使其尽可能公平地占用新到资源。在分析中具体给出了修改后速率控制模块的实现过程。通过仿真分析了AIMD算法的参数对修改后速率控制模块性能的影响。     

基于细化社会核算矩阵的突发公共事件产业影响分析

根据最新的2007年中国投入产出表,再结合其他数据编制的细化社会核算矩阵,可以用来分析突发公共事件的产业总影响和产业间影响。研究发现:劳动密集型产业以及与其他产业具有较高关联度的产业,受突发公共事件冲击的总产出影响较大;而同一突发公共事件冲击所带来的经济影响在不同产业间的分布差异较大。了解这些影响的大小,对于突发公共事件的优化管理具有重要意义。     

分裂无线传感器网络路由协议综述

无线传感器网络中,由于节点能量与通信距离的限制以及节点受到恶劣天气与环境变化等因素的影响,节点间的通信会出现间隔性,甚至直接导致分裂网络的产生。本文在介绍分裂无线传感器网络的基础上,对解决分裂网络节点或区域间通信问题的路由算法进行了综述,着重介绍了一些具有代表性的路由协议。     

基于阈值判断的动态源路由协议算法优化设计

针对移动自组织网动态源路由协议（DSR）中旧路径中断至新路径建立期间存在的丢包和端到端时延问题,设计了一种基于阈值判断的路由发现和维护算法,以优化路由协议性能。该方法首先定义节点电池能量和节点接收信号能量双阈值等级,分别用于衡量节点和既存链路状态;然后修改路由发现和路由维护算法,使动态源路由具备阈值判断功能。分别对增强型动态源路由协议（EDSR）包传递率和端到端时延等性能随节点数目和移动速度等参数的变化规律进行了软件仿真。实验结果表明,节点数目超过150或者速度小于10 m/s时,EDSR端到端时延和包传递率优于DSR,其他性能基本相当,因此EDSR协议性能得到明显改善,为低速大规模移动自组网路由协议提供了重要参考。     

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,     

Public Financial Expenditure——A Reflection of the Livelihood Improvement

In recent years.China's public finance put social construction high on the agenda and attaches more importance on livelihood insurance and improvement.The 2003-2007 public financial expenditure reflects a fact that the government isputting more emphasis on livelihood andissues concerning the people.     

Voices from the MPC and CPPCC

"Crucial for economic growth.energy utilization has its role in all economic sectors and every aspect of people's daily life.Now we are in dire need of a new profession,namely energy manager.We not only need to have passion and responsibility,but also a scientific approach to conserve energy and cut emissions.APpropriate legislation should be in place.and a special profession should be introduced to ensure the implementation of these laws and regulations."