SOJOURN TIMES IN NON-HOMOGENEOUS QBD PROCESSES WITH PROCESSOR SHARING

We study sojourn times of customers in a processor sharing queue with a service rate that varies over time, depending on the number of customers and on the state of a random environment. An explicit expression is derived for the Laplace–Stieltjes transform of the sojourn time conditional on the state upon arrival and the amount of work brought into the system. Particular attention is paid to the conditional mean sojourn time of a customer as a function of his required amount of work, and we establish the existence of an asymptote as the amount of work tends to infinity. The method of random time change is then extended to include the possibility of a varying service rate. By means of this method, we explain the well-established proportionality between the conditional mean sojourn time and required amount of work in processor sharing queues without random environment. Based on numerical experiments, we propose an approximation for the conditional mean sojourn time. Although first presented for exponentially distributed service requirements, the analysis is shown to extend to phase-type services. The service discipline of discriminatory processor sharing is also shown to fall within the framework.     

有关PTC现象的理论研究进展

概要介绍了PTC理论及与PTC现象密切相关的相变理论的研究进展 ,分析了解释PTC现象的一些典型理论模型的发展概况     

Revisiting management innovation and change programmes: strategic vision or tunnel vision?

The information systems (IS) and management literature, broadly conceived, is replete with management innovation and change programmes. All are designed to enhance business performance and competitive advantage. This paper examines five approaches which have been developed in the post-war period to improve business performance. They are Total Quality Management (TQM), Just-In-Time production management (JIT), Activity Based Costing (ABC), Business Process Re-engineering (BPR), and Process Innovation. By comparing and contrasting these approaches, it is found that considerable overlap exists in their scope, style, content, aims and objectives. In view of this, the paper argues that instead of re-inventing the wheel every few years with a new management innovation and change panacea or fad, a broader, inter-disciplinary perspective should be adopted which seeks to understand the wider ideological, historical and empirical perspective which underpins these ideas. This is instead of the tunnel vision approach which seeks only to place these ideas in a narrow organisational or managerial context.     

供给因素、结构变化、汇率与中国的机电产品贸易

基于考虑供给因素、结构变化的出口决定模型,采用两方程方法研究了外国GDP、中国GDP、结构变化、汇率与中国机电产品贸易之间的关系。研究表明：供给因素、结构变化对中国机电产品贸易有重要影响,供给因素对中国机电产品贸易的影响存在不对称性,结构变化对中国机电产品贸易的影响基本对称,汇率对中国机电产品贸易的影响存在不对称性。     

《易经》中的变通与变革观——《易》学文化精神及其现代价值讨论之四

<易经>中的变通观念有深刻的发展变化思想,而变革现又存有明显的变革天命的观念,变通的根基是自强,变革的核心是合民意,变通观、变革观是中国传统文化中最具实践价值的部分.     

论《尤利西斯》中的中国形象

<尤利西斯>是一部现代主义的鸿篇巨制,也是关于爱尔兰民族文化的历史、现状和未来的民族史诗,其中充满了乔伊斯关于民族文化与异族文化之间关系的真知灼见.在对爱尔兰民族文化之外的文化书写中,对中国文化的书写是支离破碎的,但含义也是最深刻的.<尤利西斯>再现了小说人物在外貌、饮食、特质、宗教、语言、道德等方面对中国形象的扭曲、误解和妖魔化,表现了这种定式化思维背后不同的动机和相同的危害性.当然,乔伊斯在<尤利西斯>中书写这种对中国的定式化印象的目的是揭露殖民主义文化和民族主义文化对他文化的"他者化"的手法、目的和危害,并展示殖民主义文化和民族主义文化通过大众传媒对普通民众所产生的无处不在的影响,从而达到批判殖民主义和民族主义的目的.     

民间魅性世界的万种镜像——评贾平凹的新作《高兴》

贾平凹的新作《高兴》是中国现当代文学中“农民进城”主题的进一步延伸和深化，它描摹了一个全景式丰富、多层面的民间社会，这里有下层农民工艰难的生存图景，也有他们不甘继续蛰居底层的抗争。贾氏的民间不仅是原生态、粗鄙的民间，更是充满魅性和艺术感染力的民间。在这一民间魅性世界中作家借助镜像塑造了众多相互映衬、对照的人物形象，丰富了作品的内涵，增添了小说精神意蕴。     

对学习共同体理论与实践的初探

在对学习、学习共同体的基本概念、基本特征和共同体、学习共同体的由来和发展进行初步探讨的基础上,给学习共同体进行了科学的界定。然后对作为学习共同体理论和实践产生基础的社会教育理念的变更和社会建构主义理论以及学习型组织及其在世界和我国的发展进行了介绍和探讨。最后,对我国学习共同体教育和学校管理目标模式进行了初步探讨。     

Integration and Inclusion: Illusion or Progress in Services for Disabled People?

This paper analyses the meanings of "integration" and "inclusion" in the context of disability services to determine the extent to which the latter signals a change in perspective rather than simply a change in terminology. It is argued that integration implies that disabled people need to be integrated into "mainstream" society and that it is they rather than society which is required to change. The policy response which results from this approach may thus be a technical one which focuses on physical integration alone. In contrast, inclusion takes as its starting-point the fact that a just state of affairs is one in which disabled people are included in society and hence the required policy response is a broad one which includes comprehensive civil rights legislation, an analysis of the effects of present and future policy on disabled people and the participation of disabled people in the democratic decision-making process. However, as disabled people are currently excluded from many aspects of society, the potential for an inclusive approach to be dismissed as being too idealistic is noted, and a number of possible barriers to its realization are discussed. It is concluded that whilst such barriers exist they should not, in themselves, provide a reason for inaction as an understanding of the implications of inclusion for policy and practice can provide a useful starting-point from which to bring about change.     

带稀疏惩罚的LCNN盲目图像复原

为了加强算法的稀疏性和稳定性,在SCAD基础上提出了一种新的稀疏惩罚函数,并加入到拉格朗日约束神经网络中,以克服传统盲源分离方法和独立分量分析方法的缺陷,有效地避免了方程的病态问题,提高盲目图像复原的稀疏性、稳定性和准确性。通过人工数据和真实数据的不同复原算法对比实验,证明了带稀疏惩罚的拉格朗日约束神经网络盲目图像复原技术具有良好的图像复原效果。