粒子群属性聚类的位置隐私保护

针对基于位置服务中连续查询情况下，用户自身属性信息很容易被攻击者获取，并通过关联获得用户位置隐私的情况，提出了一种利用粒子群聚类加速相似属性用户寻找，并由相似属性匿名实现用户位置泛化的隐私保护方法。该方法利用位置隐私保护中常用的可信中心服务器，通过对发送到中心服务器中的查询信息进行粒子群属性聚类，在聚类的过程中加速相似属性用户的寻找过程，由相似属性用户完成位置泛化，以此实现位置隐私保护。实验结果证明，这种基于粒子群属性聚类的隐私保护方法具有高于同类算法的隐私保护能力，以及更快的计算处理速度。     

Inverse reinforcement learning-based time-dependent A* planner for human-aware robot navigation with local vision

In an environment where robots coexist with humans, mobile robots should be human-aware and comply with humans' behavioural norms so as to not disturb humans' personal space and activities. In this work, we propose an inverse reinforcement learning-based time-dependent A* planner for human-aware robot navigation with local vision. In this method, the planning process of time-dependent A* is regarded as a Markov decision process and the cost function of the time-dependent A* is learned using the inverse reinforcement learning via capturing humans' demonstration trajectories. With this method, a robot can plan a path that complies with humans' behaviour patterns and the robot's kinematics. When constructing feature vectors of the cost function, considering the local vision characteristics, we propose a visual coverage feature for enabling robots to learn from how humans move in a limited visual field. The effectiveness of the proposed method has been validated by experiments in real-world scenarios: using this approach robots can effectively mimic human motion patterns when avoiding pedestrians; furthermore, in a limited visual field, robots can learn to choose a path that enables them to have the larger visual coverage which shows a better navigation performance.     

定子扇形片复合模设计

分析零件自身的特点和成形难点,针对成形难点制定相应的解决对策,结合类似模具在以往设计、加工、组装、使用和维护过程中遇到的问题,对定子扇形片复合模设计难点的解决方法及相关注意事项分别进行了介绍,模具经多次调试已顺利投入生产,对类似零件的模具设计具有一定的参考作用。     

南水北调中线工程受水区二期需调水量预测研究

2002年12月国务院批复了《南水北调工程总体规划》，明确中线工程分两期建设。目前，一期工程已经通水。近年来，随着社会经济的快速发展，受水区的人口、生产规模、节水水平、人们对环境的要求都发生了变化，因此有必要根据新的情况对受水区的用水需求重新预测。分析了城市化发展和城镇用水变化的新形势，依据流域、区域水资源规划成果，提出了中线二期工程受水区需调水量，并与《南水北调中线工程规划》提出的二期需调水量进行对比，以供各方参考。     

Analyzing negative SNS behaviors of elementary and middle school students in Korea

With the growing speed of SNS accelerated recently, there are increasing concerns about the possibility of young students doing negative SNS behavior. This study tried to discover the relationship between various variables such as gender, grade, SNS usage time, motives to use SNS, degree of using advanced functions of SNS, SNS dependency, and perceptions about SNS with negative SNS behaviors among elementary and middle school students. The analyses revealed that regardless of gender and grade, the most frequently committed negative behavior is ‘stealing others’ private information’ and the least is ‘cyber bullying’, while ‘contacting strangers’ showing the most significant increase with the age. With the seriousness of negative SNS behaviors classified into four levels, it was found that the biggest significant difference across the levels appears on illegal use of photos and videos, followed by on verbal abuse and on cyber bullying. It was also found that a significant positive correlation exists between each of the factors considered and the negative SNS behavior. Based on these findings, a regression analysis was conducted to successfully extract several factors as significant predictors of the negative SNS behaviors. Furthermore, factors distinguishing the lowest level from the highest level of the negative SNS behaviors were identified to be gender, SNS dependency, utilization of advanced SNS functions, and grade, with its accuracy rate reaching as high as 85.6%.     

社区居家养老服务设施的规划配置研究

社区和居家养老是我国当前和未来的主要养老模式，然而，与机构养老设施相比较而言，我国社区居家养老服务设施的发展明显滞后，具体表现为设施的建成基础薄弱、空间资源的配置要素模糊、规范和管控手段缺位等。在概述现状与问题的基础上，系统地探讨了我国社区层面养老服务资源的配置主体、配置对象和配置思路。针对养老服务需求和供给主体日益多元化的挑战，提出结合社区实际情况灵活配置服务模块的建议，采用总量控制和复合设置的规划手段落实配建，从而实现服务设施综合效益最大化的建设目标。     

大数据环境下基于K中心点优化算法的Web服务组合

在当前Web服务海量增加、现有Web服务选择算法低效、用户匹配度差的基础上，针对K中心点算法存在的质点偏移、准确率低和容易发生畸变等问题，提出一种大数据环境下基于K中心点优化算法的Web服务组合方法。该方法是在大数据环境下，根据不同用户需求满意度及Web服务QoS参数，对基于优化初始聚类中心的K中心点算法的Web服务选择及最优Web服务组合进行研究。同时针对不同的选择方法对服务动态选择及组合的准确度、迭代更新次数、候选集选择时间及选择总时间进行实验分析，验证了本文研究方法的有效性和可靠性。     

面向云计算应用层演化的隐私保护方法研究

云计算应用层中的组合服务具有演化属性,因此,隐私数据在服务组合过程中,用户的隐私数据可能会因为服务或服务流程的演化而暴露。根据服务演化的特征,以描述逻辑为基础,提出了一种面向云计算应用层演化的隐私保护方法。对隐私协议进行形式化描述;根据服务的演化特征,对服务的演化进行监控,保证满足用户的隐私需求;利用实例研究证明该方法的正确性与可行性。     

面向连续查询的敏感语义位置隐私保护方案

针对连续查询位置服务中构造匿名区域未考虑语义位置信息导致敏感隐私泄露问题，通过设计[(K,θ)]-隐私模型，提出一种路网环境下面向连续查询的敏感语义位置隐私保护方案。该方案利用Voronoi图将城市路网预先划分为独立的Voronoi单元，依据用户的移动路径和移动速度，选择具有相似特性的其他[K-1]个用户，构建匿名用户集；利用匿名用户集用户设定的敏感语义位置类型和语义安全阈值，以及用户所处语义位置的Voronoi单元，构建满足[(K,θ)]-隐私模型的语义安全匿名区域，可以同时防止连续查询追踪攻击和语义推断攻击。实验结果表明，与SCPA算法相比，该方案在隐私保护程度上提升约15%，系统开销上降低约20%。     

Next POI Recommendation Based on Location Interest Mining with Recurrent Neural Networks

Journal of Computer Science and Technology - In mobile social networks, next point-of-interest (POI) recommendation is a very important function that can provide personalized location-based...