不确定侵彻条件下引信引爆策略对炸点深度影响分析

为研究不确定侵彻条件下引信引爆策略对炸点深度的影响规律,通过拉丁超立方采样设计了数值模拟试验,采用侵彻力函数代替弹靶接触力的快速算法进行了数值模拟计算,分析了不确定侵彻条件下5种引信引爆策略的炸深控制精度及其影响因素.结果显示,其炸深控制精度从低到高排序为延时、定冲量、定能量、定轴向位移、定垂直位移.定轴向位移和定垂直位移引信可以适用于不同靶体材料,在设定值相同的条件下,利用这2种策略可以到达基本相同的炸深.侵彻速度的不确定性对延时引信炸点控制精度的影响显著,对定位移引信的影响非常小,倾角和攻角是影响定位移引信炸点控制精度的主要原因.     

无纸化考试选择题随机组卷的算法设计

在计算机网环境下进行无纸化考试时,由于机房空间的限制,邻座考生之间的相互抄袭难以控制,导致考试结果的信度降低。为了有效地确保考试的客观性、公正性,提高考试信度,针对单选题的组卷问题,从试题的随机抽取、试题排列顺序的随机改变、选项位置随机排列等方面,运用软件技术,重新构建考生的试卷,给出组卷策略的算法设计。实践表明,该软件技术措施的综合应用,在较大程度上提高了考试结果的信度。     

一种自适应的无线射频识别系统中的防冲突算法(英文)

A novel anti-collision algorithm in RFID wireless network is proposed.As it is put forward on the basis of collision tree(CT)and improved collision tree(lCT) anti-collision protocols,we call it adaptive collision tree protocol(ACT).The main novelty of this paper is that the AD strategy is introduced and used in ACT to decrease collisions and improve the tag system throughput.AD strategy means that query strings will divide into two or four branches adaptively according to the label quantity.This scheme can decrease both depth of query and collision timeslots,and avoid producing too much idle timeslots at the same time.Both theoretical analysis and simulation results indicate that the novel proposed anticollision protocol ACT outperforms the previous CT and ICT protocols in term of time complexity,system throughput,and communication complexity.     

对抗社会网络级联失效的减缓策略研究(英文)

Cascading failures are common phenomena in many of real-world networks,such as power grids,Internet,transportation networks and social networks.It's worth noting that once one or a few users on a social network are unavailable for some reasons,they are more likely to influence a large portion of social network.Therefore,an effective mitigation strategy is very critical for avoiding or reducing the impact of cascading failures.In this paper,we firstly quantify the user loads and construct the processes of cascading dynamics,then elaborate the more reasonable mechanism of sharing the extra user loads with considering the features of social networks,and further propose a novel mitigation strategy on social networks against cascading failures.Based on the realworld social network datasets,we evaluate the effectiveness and efficiency of the novel mitigation strategy.The experimental results show that this mitigation strategy can reduce the impact of cascading failures effectively and maintain the network connectivity better with lower cost.These findings are very useful for rationally advertising and may be helpful for avoiding various disasters of cascading failures on many real-world networks.     

P2P群体管理体系结构的搜索优化和自组织性研究

资源搜索和节点管理一直是非结构化Peer-to-Peer （P2P）网络研究的热点.很多不同的搜索策略和分组方案在面临高转换率,freeriding和whitewashing等特殊安全问题时将无法达到原有的性能和效率.文章提出了一个开放的具有抵抗上述特殊问题的群体管理体系结构.主要工作包括：（1）一个新的群体管理体协结构及对应的协议和双层树结构：（2）基于缓存的捷径技术和关键拓扑群体分组技术来优化搜索策略.性能评估表明提出的体系结构具有更好的搜索性能、开放性和对抗特殊问题的能力.     

GPS转发干扰模式的研究

分析证明了普通的转发干扰模式并不能有效地干扰GPS接收机,提出了设计转发干扰模式必须精确控制转发时延.干扰机截获整数个码元长度的GPS信号,根据GPS卫星、GPS接收机以及干扰机3者之间的距离关系推导出转发干扰信号的人为延时时间,在此基础上进行点对点转发干扰.在不同强度GPS信号背景噪声的影响下,转发干扰能够获得16～26dB的干扰增益(相对白噪声干扰),在很大程度上节省了干扰功率.     

悬浮式深弹拦截不确定型鱼雷作战模型研究

水面舰艇如何使用悬浮式深弹拦截鱼雷是舰艇防御鱼雷的重要问题之一。该文通过利用模糊数学知识将鱼雷报警距离分为近、中、远3个模糊区域,建立了鱼雷报警距离隶属函数关系,预估了鱼雷目标航向、航速等运动要素,最后建立了悬浮式深弹拦截不确定型鱼雷作战模型,并对作战模型进行了计算机仿真。仿真结果表明,舰艇在不能确定来袭鱼雷型号和自导方式时,选择使用悬浮式深弹这一硬杀伤方式拦截鱼雷是最为可行的方案,能够达到彻底毁伤鱼雷,从而保护舰艇安全的最终目的。     

The performance of layered broadcast with superposition coding

In wireless broadcast system, where feedback is limited and channel state information is only available at the receiver side, layered broadcasting approach has been proposed to fully utilize the channel resources by providing different levels of service quality to users with different channel conditions. However, no upper bound has been given yet to show how the layered broadcast scheme will outperform the conventional broadcast (CB) scheme. In this paper, system average achievable rate (SAAR) is defined as the mean achievable rate of all users within the coverage. Based on continuum superposition coding (SC) with infinite layers, the upper bound of the SAAR of layered broadcasting is given by the derivation of the optimal power distribution function among the superposed layers. The results show that, by promoting the experience of stronger users (users with better channel conditions) without seriously degrading the performance of weaker users (users with worse channel conditions), layered broadcasting approach greatly increases the average system performance. Copyright © 2011 John Wiley & Sons, Ltd.     

Smart Skin-Adhesive Patches: From Design to Biomedical Applications

With the advancement of medical and digital technologies, smart skin adhesive patches have emerged as a key player for complex medical purposes. In particular, skin adhesive patches with integrated electronics have created an excellent platform for monitoring health conditions and intelligent medication. However, the efficient design of the adhesive patches is still challenging as it requires a strong combination of network structure, adhesion, physical properties, and biocompatibility. To design an assimilated device, one must have a deep knowledge of various skin adhesive patches. This article provides a comprehensive review of the recent advances in skin-adhesive patches, including hydrogel-based adhesive patches, transdermal patches, and electronic skin (E-skin) patches, for various biomedical applications such as wound healing, drug delivery, biosensing, and health monitoring. Furthermore, the key challenges, implementable strategies, and future designs that can potentially provide researchers in designing innovative multipurpose smart skin patches are discussed. These advanced approaches are promising for managing the health and fitness of patients who require regular medical care.     

基于大数据的全媒体平台发展战略研究

互联网带来了第四次传播革命,使得信息更为公开和透明,信息的数量也呈指数级快速增加。2013年,人类开始进入"大数据元年"、"移动互联元年"。在移动互联和云计算的双重推动下,大数据开始进入爆发增长期。在这种巨变的时代大背景下,传统媒体的转型发展,既是技术问题,也是战略问题,必将对未来的媒体形态和格局产生深远影响。如何才能有效利用大数据技术实现传统媒体质的飞跃,进入全媒体阶段,探讨了大数据时代下全媒体平台发展的主要战略。