审计委员会制度与盈余质量的改善

本文采用2002年至2004年上市公司的数据.以盈余质量视角研究审计委员会制度的有效性.研究发现,基于各年截面数据,设有审计委员的上市公司均具有较高的盈余质量,同时也发现这种盈余质量上的差异已经存在于上市公司成立审计委员会的上一年.当控制这种成立前的盈余质量差异之后,本文发现,设立审计委员会前后,上市公司盈余质量没有显著变化.因此,本文结论并没有发现审计委员会在提高会计盈余质量方面已发挥了应有的作用.     

Path cooperative games

Cooperative games provide an appropriate framework for fair and stable profit distribution in multiagent systems. In this paper, we study the algorithmic issues on path cooperative games that arise from the situations where some commodity flows through a network. In these games, a coalition of edges or vertices is successful if they establish a path from the source to the sink in the network, and lose otherwise. Based on dual theory of linear programming and the relationship with flow games, we provide the characterizations on the core, CS-core, least-core and nucleolus of path cooperative games, which implies all of these solution concepts are polynomial-time solvable for path cooperative games.     

Energy conservation through resource-aware movement in heterogeneous mobile ad hoc networks

Energy conservation in mobile ad hoc networks is of paramount importance because most mobile nodes usually have very limited energy supply. Previous research on this issue focused on the design at the network or MAC or physical layer. In this paper, we study this problem from the new perspective of node mobility, i.e., analyzing the impact of node movement on energy conservation. In particular, armed with the inherent resource heterogeneity in mobile ad hoc networks, we propose a novel resource-aware movement strategy to make better use of some powerful nodes to achieve energy conservation. We also formulate the resource-aware movement as a NP-complete distance-constrained least-cost (DCLC) routing problem and propose an efficient heuristic solution. Extensive simulations have been used to demonstrate the effectiveness of the proposed schemes.     

人格特质、组织承诺与离职意图关系的实证研究

通过对中国联通安徽分公司131名雇员进行实证分析,考察了个人属性、内外控型人格特质、组织承诺与雇员离职意图的关系。结果发现组织承诺、内外控人格特质对离职意图有显著影响,个人属性中除婚否外,其他属性对离职意图也有显著影响。推测组织承诺将极有可能是个人属性与离职意图间的中介变量,并且对内外控人格特质与离职意图之间的关系具有调节作用。     

服务型制造网络的Holon协同需求评价方法

依据复杂网络理论分析服务型制造网络Holon协同需求问题,给出一种考虑以直觉正态模糊数表示且多Holon协同的服务型制造网络协同需求评价方法。首先,在区分Holon复合协同和递归协同基础上构建服务型制造网络协同需求评价指标体系;其次,考虑基于网络结构特征的Holon相似稳定性,根据服务型制造网络节点相似性测度分析Holon协同需求特征,并测算不同相似性测度修正的Holon网络结构熵;再次,建立面向服务型制造网络和Holon的有专家信息双向触动反馈机制,反馈包括评价指标和网络协同状况,反馈Holon信息包括基于服务型制造网络演化方向的Holon间协同需求建议和基于服务型制造网络现有状态的网络连通性Holon协同需求建议;最后由INFCWA（INFCWA_R）算子或INFCWG（INFCWG_R）算子分别对复合协同和递归协同评价信息集结并得出评价结论。方法设计过程通过例证分析说明根据服务型制造网络目标控制的Holon协同需求评价改进了群组评价效率。     

An Optimization‐Based Framework for the Identification of Vulnerabilities in Electric Power Grids Exposed to Natural Hazards

This article proposes a novel mathematical optimization framework for the identification of the vulnerabilities of electric power infrastructure systems (which is a paramount example of critical infrastructure) due to natural hazards. In this framework, the potential impacts of a specific natural hazard on an infrastructure are first evaluated in terms of failure and recovery probabilities of system components. Then, these are fed into a bi‐level attacker–defender interdiction model to determine the critical components whose failures lead to the largest system functionality loss. The proposed framework bridges the gap between the difficulties of accurately predicting the hazard information in classical probability‐based analyses and the over conservatism of the pure attacker–defender interdiction models. Mathematically, the proposed model configures a bi‐level max‐min mixed integer linear programming (MILP) that is challenging to solve. For its solution, the problem is casted into an equivalent one‐level MILP that can be solved by efficient global solvers. The approach is applied to a case study concerning the vulnerability identification of the georeferenced RTS24 test system under simulated wind storms. The numerical results demonstrate the effectiveness of the proposed framework for identifying critical locations under multiple hazard events and, thus, for providing a useful tool to help decisionmakers in making more‐informed prehazard preparation decisions.     

房价波动、 收入水平对住房消费的影响——基于SYS-GMM估计方法的区域差异分析

基于生命周期-持久收入假说,在一般随机Ramsey模型的基础上,推导包含房价、收入和财富的住房消费函数,利用2002年至2013年31个省直辖市的面板数据,采用两步System-GMM估计方法考察我国房价波动和居民收入水平对住房消费的影响.实证结果表明:房价波动对全国居民住房消费具有显著的抑制作用;其中,滞后期和当期房价波动与当期住房消费负相关,挤出效应明显;未来一期房价波动与住房消费变化方向一致,存在积极的财富效应;此外,房价波动对东中西部各地区居民住房消费的抑制作用存在较大差异,西部地区抑制效应最为明显;滞后期住房消费与当期住房消费变动方向一致,人均可支配收入波动和人均年底储蓄余额对我国人均住房消费都起着重要的支撑作用.     

活动重叠模式与资源约束下的项目调度优化

采取活动重叠模式通常是加速研发的有效手段,带有活动重叠的资源受限项目调度问题是经典资源受限项目调度问题的扩展.首先,深入分析了活动重叠对于项目调度的影响,对活动重叠及其不确定进行详细描述与建模,提出了活动重叠导致下游活动返工时间的二项分布概率模型;其次,构建了以最小化研发项目期望工期为目标的优化调度模型,设计了基于串行进度生成机制的遗传算法对大规模问题进行优化求解;最后,基于PSPLIB J60问题库中480个算例分析了该算法的计算结果,并考察了网络参数、资源参数和重叠参数变化时,采用活动重叠模式对缩短项目工期的影响.研究结果表明:活动对资源的需求强度越小或资源稀缺程度越低,可重叠活动对数量就会增加,项目工期缩短得越明显;网络复杂度的变化对缩短项目工期的影响不大;项目中重叠活动对越多,重叠导致的下游活动返工的概率越小,项目工期缩短的越明显.     

ERP项目咨询与监理融合机制的研究

结合实际企业ERP系统实施过程中咨询与监理的经验,讨论了ERP项目咨询与监理及其融合的必要性、特点和运作规律.     

虚拟企业成功的影响因素

虚拟企业是为满足顾客需要而形成的一种新型企业组织形式。论述了虚拟企业的具体涵义及其所具有的优势,并概括出影响虚拟企业成功的9种主要因素。