Energy conservation through resource-aware movement in heterogeneous mobile ad hoc networks

Energy conservation in mobile ad hoc networks is of paramount importance because most mobile nodes usually have very limited energy supply. Previous research on this issue focused on the design at the network or MAC or physical layer. In this paper, we study this problem from the new perspective of node mobility, i.e., analyzing the impact of node movement on energy conservation. In particular, armed with the inherent resource heterogeneity in mobile ad hoc networks, we propose a novel resource-aware movement strategy to make better use of some powerful nodes to achieve energy conservation. We also formulate the resource-aware movement as a NP-complete distance-constrained least-cost (DCLC) routing problem and propose an efficient heuristic solution. Extensive simulations have been used to demonstrate the effectiveness of the proposed schemes.     

铝钢异种金属CMT焊接变形研究

针对目前使用冷金属过度焊（CMT）对铝钢异种金属薄板进行焊接时,存在焊接质量差,焊接热变形及使用性能低等缺点,对薄板件焊接过程采用SYSWELD软件进行模拟。通过不同的试验参数进行组合,得出金属薄板在X,Y以及整体方向上的焊接变形量,分析不同焊接参数对焊接热变形的影响规律。结果表明：在达到焊接要求的前提下,应尽量减少焊接时间和焊接电流;在一定焊接电压范围内,焊接电压越大,相同时间内焊接变形量就越大,Y方向焊接变形值约为X方向的1.5倍;为了避免焊接变形量过大,宜选用相对较大的焊接速度。     

晚清民初苏籍译家群的生发及地域文化缘由

晚清民初在西方文化与科学的译介和传播方面,苏籍译家作出了重要贡献.他们具有家国天下的胸怀,为拯救民族危难、改善社会民生、启迪民智寻找良方.他们立志翻译事业,译笔间传达出对民族兴衰成败的使命感.基于史料的爬梳与总结,聚焦晚清民初时期典型的苏籍译家的译事、译著,审视他们的翻译贡献,并从地域人文传统的视角进一步窥探苏籍译家群生发的地域缘由.     

城市化、高等教育扩张对地区收入差距的影响 ——基于中国省级面板数据的实证研究

利用2002—2014年全国31个省市的面板数据考察城市化、高等教育扩张对地区收入差距的影响.结果显示:从全国层面来看,城市化对缩小地区间收入差距具有显著的消极作用,当地区城市化水平提高时,地区收入差距扩大;高等教育扩张对缩小地区收入差距具有显著的正向作用.从不同地区结果来看,东部地区城市化水平普遍较高,对地区收入差距的影响并不显著,而高等教育扩张对地区收入差距具有显著的负向作用.中部地区的结果与东部地区的结果基本一致.相比于东中部地区,西部地区城市化水平较低,其水平的提高不利于地区间收入差距的缩小,而高等教育扩张的影响并不显著.最后从合理推进城市化和高等教育扩张两个角度提出四个政策性建议.     

“关系圈”稀释“受害者圈”：企业环境污染与村民大多数沉默的乡村逻辑—山东N村个案研究

基于山东N村手套加工厂及其环境影响的调查发现,村落内生企业的关系嵌入与乡村社会分化的叠加效应,是大多数村民面对环境危害而保持沉默的乡村逻辑。乡村作为兼具乡土底色与经济理性的生活共同体,被企业污染建构为具有统合性的整体受害者圈。“同住一个村”的共同体意识形塑大部分村民的环境沉默行为与少数积极分子环境抗争的自我克制,而企业生产建构的获利者群体进一步分化了受害者圈层,村落“双重圈层”互嵌式关系格局阻隔村民通过集体行动制止企业污染的底层路径。农村内生污染企业的嵌入属性加深了村落社会分化、侵蚀了农村环境治理的社会基础,更提醒关注农村污染企业的社区嵌入与村民环境行为选择的复杂性关联。     

Online monitoring of high-dimensional binary data streams with application to extreme weather surveillance

With the rapid development of modern sensor technology, high-dimensional data streams appear frequently nowadays, bringing urgent needs for effective statistical process control (SPC) tools. In such a context, the online monitoring problem of high-dimensional and correlated binary data streams is becoming very important. Conventional SPC methods for monitoring multivariate binary processes may fail when facing high-dimensional applications due to high computational complexity and the lack of efficiency. In this paper, motivated by an application in extreme weather surveillance, we propose a novel pairwise approach that considers the most informative pairwise correlation between any two data streams. The information is then integrated into an exponential weighted moving average (EWMA) charting scheme to monitor abnormal mean changes in high-dimensional binary data streams. Extensive simulation study together with a real-data analysis demonstrates the efficiency and applicability of the proposed control chart.     

A multivariate zero-inflated binomial model for the analysis of correlated proportional data

In this paper, a new multivariate zero-inflated binomial (MZIB) distribution is proposed to analyse the correlated proportional data with excessive zeros. The distributional properties of purposed model are studied. The Fisher scoring algorithm and EM algorithm are given for the computation of estimates of parameters in the proposed MZIB model with/without covariates. The score tests and the likelihood ratio tests are derived for assessing both the zero-inflation and the equality of multiple binomial probabilities in correlated proportional data. A limited simulation study is performed to evaluate the performance of derived EM algorithms for the estimation of parameters in the model with/without covariates and to compare the nominal levels and powers of both score tests and likelihood ratio tests. The whitefly data is used to illustrate the proposed methodologies.     

市场经济条件下医院营销策略分析

文章从医院营销的概念入手,分析了医院营销中存在的误区,提出了医院营销的策略,并指出了医院营销的未来发展趋势。     

浅谈企业税收筹划及运用

税收筹划是指企业在税收政策允许的前提下,以追求效益最大化为目的,通过对企业生产经营、投资、理财等活动的事先筹划和安排,尽可能地节约税款,以获得最大的税收利益。其运用主要在以下几个方面:组建过程,投资决策过程,生产经营过程,对外筹资及股利分配过程。     

论中国近代高等理科课程的形成与发展

从洋务运动时期、维新运动时期、辛亥革命时期、抗日战争和解放战争时期四个方面论述了中国近代高等理科课程的形成与发展,从而看出近代中国已经初步形成了以传授自然科学知识为主、具有现代特征的高等理科教育体系。