How do different types of intragroup conflict affect group potency in virtual compared with face-to-face teams? A longitudinal study

The number of organizations using teamwork is increasing. In this context, group potency has emerged as a key construct in group research. Moreover, in the last decades, information and communication technologies (ICT) have allowed organizations to form virtual teams. Consequently, a considerable amount of research has analysed the functioning of virtual teams. We focus on intragroup conflict as a relevant antecedent of potency in computer-mediated communication groups. Specifically, the aim of this research is to examine the role of ICT in the relationship between intragroup conflict and group potency in a longitudinal study. A laboratory experiment was carried out comparing 44 groups working in two communication media (face-to-face and computer-mediated communication). The groups developed a project over a one-month period. The results show that communication media play a moderator role between intragroup conflict (relationship and task conflict) and group potency. Implications of these results are discussed.     

Using a style-based ant colony system for adaptive learning

Adaptive learning provides an alternative to the traditional “one size fits all” approach and has driven the development of teaching and learning towards a dynamic learning process for learning. Therefore, exploring the adaptive paths to suit learners personalized needs is an interesting issue. This paper proposes an extended approach of ant colony optimization, which is based on a recent metaheuristic method for discovering group patterns that is designed to help learners advance their on-line learning along an adaptive learning path. The investigation emphasizes the relationship of learning content to the learning style of each participant in adaptive learning. An adaptive learning rule was developed to identify how learners of different learning styles may associate those contents which have the higher probability of being useful to form an optimal learning path. A style-based ant colony system is implemented and its algorithm parameters are optimized to conform to the actual pedagogical process. A survey was also conducted to evaluate the validity and efficiency of the system in producing adaptive paths to different learners. The results reveal that both the learners and the lecturers agree that the style-based ant colony system is able to provide useful supplementary learning paths.     

A methodology to incorporate product mix variations in cellular manufacturing

The identification of part families and machine groups that form the cells is a major step in the development of a cellular manufacturing system and, consequently, a large number of concepts, theories and algorithms have been proposed. One common assumption for most of these cell formation algorithms is that the product mix remains stable over a period of time. In today’s world, the market demand is being shaped by consumers resulting in a highly volatile market. This has given rise to a new class of products characterized by low volume and high variety. To incorporate product mix changes into an existing cellular manufacturing system many important issues have to be tackled. In this paper, a methodology to incorporate new parts and machines into an existing cellular manufacturing system has been presented. The objective is to fit the new parts and machines into an existing cellular manufacturing system thereby increasing machine utilization and reducing investment in new equipment.     

TCG命令验证协议的改进方法

经过分析显示可信计算联盟(TCG)命令验证协议会受到一种基于Dolev-Yao模型的中间人攻击,对系统的可信性和安全性造成影响。针对该攻击,文章提出一种协议改进方法。在改进后的协议中,可信平台模块(TPM)和访问者能对会话状态进行有效的沟通,从而抵御中间人攻击。     

Sampled-data based average consensus with measurement noises: convergence analysis and uncertainty principle

In this paper, sampled-data based average-consensus control is considered for networks consisting of continuous-time first-order integrator agents in a noisy distributed communication environment. The impact of the sampling size and the number of network nodes on the system performances is analyzed. The control input of each agent can only use information measured at the sampling instants from its neighborhood rather than the complete continuous process, and the measurements of its neighbors’ states are corrupted by random noises. By probability limit theory and the property of graph Laplacian matrix, it is shown that for a connected network, the static mean square error between the individual state and the average of the initial states of all agents can be made arbitrarily small, provided the sampling size is sufficiently small. Furthermore, by properly choosing the consensus gains, almost sure consensus can be achieved. It is worth pointing out that an uncertainty principle of Gaussian networks is obtained, which implies that in the case of white Gaussian noises, no matter what the sampling size is, the product of the steady-state and transient performance indices is always equal to or larger than a constant depending on the noise intensity, network topology and the number of network nodes.     

非平衡拓扑结构的多智能体网络系统一致性协议

针对多智能体网络系统,本文分别研究了非平衡拓扑结构的多智能体连续状态和离散状态下的一致性协议.首先提出了能使用有向图表示的多智能体网络系统的拓扑结构,并根据该拓扑结构建立了网络系统的1阶数学模型和提出了多智能体网络系统一致收敛准则.对于多智能体网络连续系统,该系统的一致平衡点最终收敛于初始状态的凸组合,本文最终确定了非平衡拓扑结构的一致平衡点.如果多智能体网络系统的拓扑结构没有改变,在离散状态下系统的一致平衡点仍收敛于初始状态的凸组合,并且离散状态下系统的一致平衡点与连续状态下系统的一致平衡点相等.最后采用8个智能体组成的网络拓扑进行计算机仿真,验证理论的正确性.     

一种新型遥感图像配准方法

提出了一种新型全自动稳健的遥感图像配准算法。首先,在图像二维平面空间和尺度空间中同时检测局部极值作为特征点,并在特征点邻域提取局部不变特征描述子一尺度不变特征变换（SIFT）。然后,利用距离测度进行SIFT特征匹配得到初步的匹配集合。最后,运用稳健的随机采样一致性（RANSAC）算法将匹配点集划分为内点和外点,在内点域上精确地估计出图像变换模型。实验利用仿真数据测试了SIFT特征的可重复性和可匹配性,利用卫星图像验证了该自动配准算法的有效性和稳健性。     

基于一致性指标的两类不确定偏好信息集结

研究了两类区间数判断矩阵偏好信息的集结问题.首先,基于Saaty提出的数字互反判断矩阵一致性检验指标(CR),给出了区间数互反判断矩阵的满意一致性条件;然后利用互反与互补判断矩阵之间的关系求解出数字互补判断矩阵的一致性指标(CGCI),并在此基础上给出了区间数互补判断矩阵的满意一致性条件;最后建立了一致性指标最大的两类区间数判断矩阵偏好信息的集结模型,并用此模型解决了供应链中伙伴企业的选择问题.     

基于幂均算子的区间型多属性决策方法

针对决策矩阵元素为区间数的不确定多属性决策问题,提出一种新的决策方法．定义了区间数幂均算子和区间数的相似度,利用一致度矩阵获得每个属性与其他属性的相对一致度．通过区间数幂均算子集成得到方案的综合属性值,进而给出了方案的排序结果．该方法不需要求解属性的权重．应用实例表明了所提出方法的有效性和实用性．     

一种提高Vicsek模型收敛效率的新方法

针对Vicsek模型收敛速度较慢和一致程度较低的问题,利用动态网络的拓扑结构并结合复杂网络中度的概念,提出一种以度为权重提高Viesek模型收敛效率的新方法.进一步以动态网络的度的幂指数得到模型的推广形式,该指数的范围为[0,∞).仿真实验结果表明,改进后模型的收敛效率优于原模型,且收敛效率随着指数的增加而增大.