Staying safe and visible via message sharing in online social networks

As an imperative channel for fast information propagation, online social networks (OSNs) also have their defects. One of them is the information leakage, i.e., information could be spread via OSNs to the users whom we are not willing to share with. Thus the problem of constructing a circle of trust to share information with as many friends as possible without further spreading it to unwanted targets has become a challenging research topic but still remained open. Our work is the first attempt to study the Maximum Circle of Trust problem seeking to share the information with the maximum expected number of poster’s friends such that the information spread to the unwanted targets is brought to its knees. First, we consider a special and more practical case with the two-hop information propagation and a single unwanted target. In this case, we show that this problem is NP-hard, which denies the existence of an exact polynomial-time algorithm. We thus propose a Fully Polynomial-Time Approximation Scheme (FPTAS), which can not only adjust any allowable performance error bound but also run in polynomial time with both the input size and allowed error. FPTAS is the best approximation solution one can ever wish for an NP-hard problem. We next consider the number of unwanted targets is bounded and prove that there does not exist an FPTAS in this case. Instead, we design a Polynomial-Time Approximation Scheme (PTAS) in which the allowable error can also be controlled. When the number of unwanted targets are not bounded, we provide a randomized algorithm, along with the analytical theoretical bound and inapproximaibility result. Finally, we consider a general case with many hops information propagation and further show its #P-hardness and propose an effective Iterative Circle of Trust Detection (ICTD) algorithm based on a novel greedy function. An extensive experiment on various real-world OSNs has validated the effectiveness of our proposed approximation and ICTD algorithms. Such an extensive experiment also highlights several important observations on information leakage which help to sharpen the security of OSNs in the future.     

Linking perceived organizational support with employee work outcomes in a Chinese context: Organizational identification as a mediator

Perceived organizational support (POS) is viewed as an important explanatory framework for understanding the relationship between employees and the workplace, and is regarded by some researchers as central in understanding job-related attitudes and behaviors of employees. However, less research has taken into account the role of organizational identification, which reflects how individuals define the self with respect to their organization, as a potential influence on such relationships. Drawing on a cross-organizational sample of 238 subordinate-supervisor dyads from the People’s Republic of China, we examined whether organizational identification mediates the effect of perceived organizational support (POS) on work outcomes including turnover intentions, work performance, and organizational citizenship behavior (OCB). Results from the current study showed that organizational identification fully mediates the relation of POS to OCB-directed to individuals, and partially mediates relations between POS and other work outcomes (turnover intention, work performance, OCB-directed to organization). Implications for management theory and practice are discussed.     

卫星地球站EMI测量方法

讨论了卫星地球站EMI(电磁干扰)的测量方法,给出了有关计算公式,最后介绍了一个测试实例。     

社会正义:科学发展观的伦理精神

科学发展观贯穿着一种伦理精神,那就是社会正义。科学发展观的主题是社会发展,首先是经济发展,而社会正义是经济发展的内在要求。科学发展观的核心是以人为本,而以人为本就要用正义的原则处理各方面的利益关系。科学发展观的根本内容是全面、协调、可持续发展,而要坚持全面、协调、可持续发展,就需要以正义的精神协调好经济与政治、文化的关系,城乡之间、区域之间以及中国和外国之间的关系,人与自然的关系。     

多频激励作用下Duffing-van der Pol系统的分岔

首先利用多尺度法分析了Duffing—van der Pol系统在多频激励下的主共振响应，得到了该系统的一次近似解。然后利用数值方法研究了系统参数对近似解幅频曲线的影响。最后，运用奇异性理论得到了系统的全部分岔响应曲线，为这一类系统的动态分析与设计提供了理论依据。     

西南少数民族地区新农村建设的特殊性

新农村建设是“十一五”期间我国“三农”问题的总方针,是农村发展的远景目标和宏伟蓝图。新农村建设的难点在少数民族地区。本文以西南少数民族聚居区为例,系统分析与总结了这一地区在建设社会主义新农村中所面临的六大限制,明确提出了新农村建设的发展思路和六大建设重点,指出在新农村建设过程中需要处理好的四大关系。     

噪声背景下提取调制信息的改进奇异值分解技术

在介绍现有奇异值分离技术基本原理及其在故障诊断中的应用的基础上，研究了利用信号时间序列重构的吸引子轨迹矩阵奇异值分布特征与信号特征的关系，引入自相关函数定量计算重构矩阵的延时步长，改进了现有算法，使得吸引子轨迹矩阵的重构更加合理。研究表明该方法能在强噪声背景下提取出所需的调制信号，并成功用于齿轮箱调制故障信号的提取。     

Parental reactions to developmental disabilities in Chinese American families

Families of Chinese American children with mental retardation and developmental disabilities were interviewed regarding their attitudes and coping experiences. Chinese American parents, like other American parents, reacted to the crisis with intense feelings and needs. The parents revealed a lack of knowledge and understanding of the diagnosis. Chinese belief systems about health and illness were present in the parents' concepts of causation and treatment.Hunter College School of Social Work.     

纽扣发展史浅谈

本文旨在通过分析纽扣在东方和西方各自的发展过程,以及在不同的历史时期所扮演的角色,并比 较两者之间的区别。探讨纽扣在现代服装中的作用和未来的发展前景。     

高职教学实践计划之探索

高等职业教育的目标是培养具有职业定向性的技术型、技能型应用人才。因此 ,实践课的比重和效果在整个教学环节中应是一个重要因素。本文以经济秘书专业为例 ,提出了制定实践课实训计划的方法、步骤和要求。