Embracing transformational leadership: Team values and the impact of leader behavior on team performance.

The authors investigated the relationship between transformational leadership behavior and group performance in 218 financial services teams that were branches of a bank in Hong Kong and the United States. Transformational leadership influenced team performance through the mediating effect of team potency. The effect of transformational leadership on team potency was moderated by team power distance and team collectivism, such that higher power distance teams and more collectivistic teams exhibited stronger positive effects of transformational leadership on team potency. The model was supported by data in both Hong Kong and the United States, which suggests a convergence in how teams function in the East and West and highlights the importance of team values. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

求解上层含约束条件的模糊二层多随从线性规划的结构元方法

讨论了一类上层含约束条件的模糊二层多随从线性规划模型;利用结构元理论,证明了该模型的最优解等价于上层含约束条件的二层多随从线性规划模型最优解;并通过极点搜索法,得到了该模型最优解;最后通过数值算例验证了该方法的可行性。     

A Parallel Indexing Cam Mechanism with Internal Placed Followers

A new type of parallel indexing cam mechanism is discovered.The composition of the cam profile is proposed and the formulas of the mechanism parameters are established by synthesis of its configuration and size.The equations for working pro- file and pressure angle of the cam are derived based on the inverse model and the derivative of pitch curve of cams.An example is given and demonstrates that it is available to design the new mechanism using the derived expressions.     

Asking the right questions about leadership: Discussion and conclusions.

Five questions prompted by the articles in the American Psychologist special issue on leadership (January 2007, Vol. 62, No. 1., see records 2006-23492-001, 2006-23492-002, 2006-23492-003, 2006-23492-004, 2006-23492-005, and 2006-23492-006) suggest some new directions for leadership research: (1) Not do leaders make a difference, but under what conditions does leadership matter? (2) Not what are the traits of leaders, but how do leaders' personal attributes interact with situational properties to shape outcomes? (3) Not do there exist common dimensions on which all leaders can be arrayed, but are good and poor leadership qualitatively different phenomena? (4) Not how do leaders and followers differ, but how can leadership models be reformulated so they treat all system members as both leaders and followers? (5) Not what should be taught in leadership courses, but how can leaders be helped to learn? (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于观测器的无人机编队自适应容错控制

针对多无人机编队飞行中的僚机故障问题,设计了一种基于观测器的自适应容错控制方法。首先,基于领导跟随法建立了无人机编队模型及僚机故障的编队模型,并将其划分为位置子系统与偏航角子系统。其次,基于观测器技术对位置子系统中的状态和故障进行观测,并结合观测的状态和故障信息构造状态反馈控制律;然后,基于自适应方法给出偏航角子系统的控制设计方案,并用Lyapunov理论证明系统跟踪误差最终有界收敛。通过仿真,本文算法在发生故障后对系统的完全跟踪时间和稳态误差分别比基于鲁棒故障估计的方法最大降低了76%和70.3%,并且均比传统观测器的方法明显减少较大,证明了本文算法能更好的克服偏差故障带来的不利影响,有效实现四旋翼无人机群的编队飞行。     

一种分布式系统中线程池的设计与实现

随着网络和分布式计算的日益发展,负载数量迅速增长,如何在大负载情况下保证高效的吞吐率是构建服务器时所面临的问题,目前广泛采用的技术之一是线程池。借鉴Leader／Followers模式,设计并实现了一类高效的线程池,并针对分布式系统环境做了进一步的改进。此方法已经应用到分布事务监控器OnceTX的实现中,并取得了很好的效果。     

基于反求技术的摆动从动件空间凸轮CAD

由于测绘点的实际接触点在理论上存在差异,摆动从动件空间凸轮机构的反求问题目前仍未获取很好解决,本文在空间凸轮反求ＣＡＤ中,担子 利用廓面测绘数据根据共轭面面原理反求出从动件运动规律,再利用该运动规律和有关结构参数重新解析设计出廓面的新方法。文中对反求方法和测绘数据进行了分析;提出了理论廓面、实际廓面的相关性质;在此基础上,利用共轭曲面原理导出了从动件运动反求的非线性规划数学模型,给出了算法。本文的     

Followers or Fradulents? An Analysis and Classification of Twitter Followers Market Merchants

Online Social Networks act as a popular forum to promote and manage the reputation of aristocrats. Generally, big organizations, politicians, celebrities, and journalists require a huge number of followers/fans to promote and manage their reputation on Online Social Networks such as Twitter. This demand of more followers has originated Twitter Followers Market that deals with the sale and purchase of fake/compromised Twitter accounts. In this paper, an analysis of merchants of this marketing industry has been conducted using graph- and content-based features. The present study has been conducted by collecting 15,750 tweets related to the sale or purchase of Twitter followers posted by around 995 users. The analysis infers that the merchants of this marketing industry fulfill the characteristics of spammers as stated by the rules and policies of Twitter. Further, machine learning classification approach has been used to categorize these merchants from genuine users based on their behavioral features. To the best of our knowledge, this is the novel study to analyze and then categorize the behavior of such merchants involved in the sale of Twitter accounts as spammers.     

A statistical method for identifying different rules of interaction between individuals in moving animal groups

The emergent patterns of collective motion are thought to arise from application of individual-level rules that govern how individuals adjust their velocity as a function of the relative position and behaviours of their neighbours. Empirical studies have sought to determine such rules of interaction applied by ‘average’ individuals by aggregating data from multiple individuals across multiple trajectory sets. In reality, some individuals within a group may interact differently from others, and such individual differences can have an effect on overall group movement. However, comparisons of rules of interaction used by individuals in different contexts have been largely qualitative. Here we introduce a set of randomization methods designed to determine statistical differences in the rules of interaction between individuals. We apply these methods to a case study of leaders and followers in pairs of freely exploring eastern mosquitofish (Gambusia holbrooki). We find that each of the randomization methods is reliable in terms of: repeatability of p-values, consistency in identification of significant differences and similarity between distributions of randomization-based test statistics. We observe convergence of the distributions of randomization-based test statistics across repeat calculations, and resolution of any ambiguities regarding significant differences as the number of randomization iterations increases.     

An experimental study of diesel engine cam and follower wear with particular reference to the properties of the materials

The main objective of this paper is to study and experimentally quantify the cam and follower wear mechanisms of a diesel direct valve-gear. Camshafts are made of nodular cast iron, surface hardened, ion nitrided and nitrosulphurized, and those made of grey chilled cast iron are mated with followers made of chilled grey cast iron and hardened steel. The investigation was carried out on a laboratory bench equipped with an engine head with a camshaft, followers and systems creating the conditions necessary for a routine run of the valve gear. Cam wear was defined by comparing the profile lifts of the cams. The height of the followers was measured using a coordinative measuring machine and a perpendicular optimeter. The rotational speed, valve displacement and the torque required by the valve gear were measured. Camshaft C9 and the thimble shaped followers with regulating plates F6 were also examined in a diesel engine. The effects of the materials the kinematic pair was made of, heat treatment and thermochemical treatment, the cams' own stresses at the moment-of-friction value, as well as the extent and nature of element wear, were analysed.