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。     

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。     

无线传感器网络在农田数据监测中的应用研究——基于蚁群路由算法

采用一种优化信息素的蚁群路由算法,解决了无线传感器网络在农田数据监测中的数据传输路径问题。改进的蚁群路由算法综合考虑了传感器节点造价高昂、节点能量补充困难、信号强度易受障碍物影响以及传感器网络在农田中的应用特点等问题,在时间复杂度不变的情况下,延长了无线传感器网络的生命周期。通过matlab仿真证明:与基本蚁群路由算法相比较,采用改进的蚁群路由算法所找到的路径,具有"热路径"长度更短,无线传感器网络能耗更加均衡的优点。     

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."     

Slowdown Trade Surplus Growth

According to Ma Kai＇s economic planning report submitted to the NPC session on March 5th,（Ma Kai is the Minister in charge of the National Development and Reform Commission）,the government has listed the slowdown in trade surplus growth and the steady expansion of external investment as major tasks for 2008.     

Ouyang Riping： A Hero Besides Entrepreneur

A bout fifty years ago. a baby＇s cry broke the sky of quietness, in a small and beautiful town of Hunan province, which surroundcd by green hills and clear water. Though his .birth brought his family great happiness and hope just as any new life, nobody knew that the little boy would get great achievement when he grow up. even start his business oversea, and earn international honor. Let＇s share with you the entrepreneur Ouyang Riping＇s story, which may insights thcsc people who want to succeed and complete oneself in favorite condition or adversity rather leave things to so-called fate.     

Belarus, A Chinese Fort in Europe

＂In recent years, we＇ve found increasing interest from Chinese investors in the Belarus economy. Please let China know, Belarus is always ready to be a true friend to China. We have built a fort in Europe for China,＂ the President of Belarus, Alexander Lukashenko told Zhou Xiaochuan, President of the Bank of China, during his visit to the capital of Minsk, on January 8th, he expressed his high praise and firm confidence in the development of Sino-Belarusian relations.     

What＇s Behind Spring Festival？

Similar to what the Christmas Day means for the westerners,the Spring Festival is the most important celebration for Chinese people.This big event according to Chinese traditional lunar calendar relaxes and pleases the whole country as the happiest gathering time of the year.National-wide crusade for going back home,too-difficult-to-get train tickets,generous family-going-out shopping,Miaohui laundering,New Year Eve reunion dinner,visiting friends and relatives,watching annual TV gala......each piece of clue reminds us of the smell of Chinese Spring Festival.     

KEY WDRDS for Foreign Investment in China

FDI(Foreign Direct Investment),a component of a country's national financlal accounts,is investment of foreign assets into domestic structures,equipment,and organizations.It does not include foreign investment into the stock markets,concession and subcontract.FDI iS thought to be more useful to a country than investments in the equity of its companies because equity investments are potentially "hot money"which can leave at the first sign of trouble,whereas FDI is durable and generally useful whether things go well or badly.     

Universal Coverage, Pinpoint Illustration and Profound Impact HTC 2008 Intermedia Recommendation and Introduction Meeting

Holding 88 percent of train media resources across China, based on "Time Cube", on the 2008 Intermedia Recommendation and Introduction Meeting on December 19, 2007, HTC announced its high-profile strategy of tour marketing and tapping the immeasurable potentials on the train. Meanwhile, HTC officially launched its brand new product Olympic Train on the meeting, providing a fabulous platform for all the brands that are prepared to do a smart marketing on the occasion of 2008 Olympic Games.     

Market presence in China strengthened Network growth and Dual-Chinese-Hub Strategy More frequet Flyer Benefit——Air China and shanhai Airlines Join Star Alliance

In the end of 2007, Air China Limited (hereinafter "Air China") and Shanghai Airlines, formally joined Star Alliance at a ceremony held in the new Terminal Three at Beijing Capital International Airport. With the addition of the two Chinese airlines, Star Alliance now has 19 member carriers operating 17,000 daily flights to 897 destinations in 160 countries.     

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.