Location privacy preservation approach towards to content sharing on mobile online social network

A privacy access control model for content sharing was presented to fine-grained control users' location infor-mation associated with sharing content in mobile social network. A k-anonymity privacy algorithm for privacy settings was given to protect against inference attack on a content sharing service provider server. To balance the privacy and quality of service, a location shifting method was presented. Finally experimental results demonstrate the validity and practicality of the proposed approach.     

基于失效情景的应急设施选址问题

非常规突发事件巨大的破坏力以及发生时间、地点和规模的不确定性,使应急系统内设施有可能被破坏而失效,因此选址时必须考虑设施失效情景的发生.给出以最大限度覆盖用户需求为目标,基于失效设施数目具有不确定性情景的设施选址双层随机规划模型;通过计算模型上下界,给出减小规模的等价模型,降低了双层规划求解难度;最后实验验证了模型的合理性,并给出新增选址方案.     

Building and analyzing the US airport network based on en-route location information

From a complex network perspective, this study sets out two aims around the US airport network (USAN) which is built from en-route location information of domestic flights in the US. First, we analyze the structural properties of the USAN with respect to its binary and weighted graphs, and second we explore the airport patterns, which have wide-ranging implications. Results from the two graphs indicate the following. (1) The USAN exhibits scale-free, small-world and disassortative mixing properties, which are consistent with the mainstream perspectives. Besides, we find (2) a remarkable power relationship between the structural measurements in the binary graph and the traffic measurements in the weighted counterpart, namely degree versus capacity and attraction versus volume. On the other hand, investigation of the airport patterns suggests (3) that all the airports can be classified into four categories based on multiple network metrics, which shows a complete typology of the airports. And it further indicates (4) that there is a subtle relationship between the airport traffic and the geographical constraints as well as the regional socioeconomic indicators.     

Influence of Control Parameters on the Competition Between Spiral Waves and Target Waves

In this paper we systematically investigate the influence of control parameters on the competition results between spiral waves and target waves. Driving frequency f , amplitude A and injection area n of the input signals are three important parameters and the competition results between spiral waves and target waves are influenced by these three parameters remarkably. Based on these understandings we can control spiral waves effectively by suitable combination these parameters to generate faster target waves. And the effective controllable parameter regions are also studied.     

A survey of ‘young social’ and ‘professional’ users of location-based services in the UK

The objective of this study was to assess the response to location-based services (LBS) by three key demographic groups within the United Kingdom. This study took the form of a survey of relevant demographics, attitudes and consumer behaviour undertaken via a web-based survey. Results are based on over 1200 respondents, filtered and segmented into three demographic groups who are typically early adopters of new technology. There were positive attitudes towards a range of LBS, with the major exception being location-based advertising. There were mixed views towards location-based gaming and safety camera information. There were low levels of awareness of many services. The levels of use were typically under 20% for all types of LBS.     

Neutron radiation damage in zirconium and its alloys

There has been much research and speculation recently on the nature of radiation induced defects in zirconium and its alloys, and in particular on the absence of voids at high fluences and temperatures in the range 0.3 to 0.5 T _m (T _m is the absolute melting temperature). Wolfenden and Farrell¹ have reviewed the evidence and suggest that α-Zr has so far resisted void formation during neutron irradiation because of: (a) the absence of a dislocation (loop or tangle) structure and/or (b) a low insoluble gas (e.g. helium) content.     

双波段红外探测设备同靶标共航路测试方法研究

针对双波段红外探测设备不同波段的探测要求,利用曳光管双波段辐射特性,提出无人机加载曳光管作为低空移动光电靶,实现同一靶标满足双波段测试要求;通过对无人机航路距离和航向的统筹设计,实现同一个飞行航次满足作用距离和目标数据精度等多个测试项目;文中对目标航迹真值精度进行深入分析,总结出在不同条件下,航路、航向及布站等相关参数的关联和设置方法,为该测试项目组织实施提供充分的技术准备和选择空间。     

复杂电磁环境下微弱目标探测技术研究

利用广播、电视以及卫星等信号为照射源的无源雷达,在复杂电磁环境下的干扰信号严重影响了远距离微弱目标的探测,为此提出了空时二维反干扰处理和二维长时相干积累技术。重点分析最大信干噪比（MSINR）准则的空域自适应零点形成技术和基于遗忘因子的改进型递推最小二乘（RLS）时域自适应处理算法,解决了微弱目标长时积累的可实现问题。最后在实验系统中进行了实际数据的仿真和验证,提高了微弱目标的检测概率,同时大目标的信杂比也提高了5 dB 以上,在实际工程中得到了很好的应用。