基于复杂网络的甲型H1N1流感病毒传播研究

基于复杂网络理论,研究了甲型HIN1流感病毒的传播机制。根据实证数据分析,建立了一个甲型HIN1流感病毒传播的小世界网络模型。通过对病毒传播中个体的接触程度、传染概率、潜伏期、增加个体免疫四个因素的研究,分析了当前应对甲型HIN1流感病毒防控措施的有效性。     

Structure Prediction and Computation of Sparse Matrix Products

We consider1 the problem of predicting the nonzero structure of a product of two or more matrices. Prior knowledge of the nonzero structure can be applied to optimize memory allocation and to determine the optimal multiplication order for a chain product of sparse matrices. We adapt a recent algorithm by the author and show that the essence of the nonzero structure and hence, a near-optimal order of multiplications, can be determined in near-linear time in the number of nonzero entries, which is much smaller than the time required for the multiplications. An experimental evaluation of the algorithm demonstrates that it is practical for matrices of order 103 with 104 nonzeros (or larger). A relatively small pre-computation results in a large time saved in the computation-intensive multiplication.     

“人力车夫情结”与五四新文学运动

受"劳工神圣"、"平民主义"等思想观念的影响,五四新文学对人力车夫这一特殊社会群体给予了深切的关注和同情,形成了五四新文学中的"人力车夫情结"。人力车夫是五四知识分子与城市底层劳动者生活联系和情感联系的一条纽带和重要触点,五四作家通过人力车夫这个群体了解城市贫民的生活和思想,他们的平民意识、平民文学观念也在描写人力车夫的作品中得到明确的表现。同时,五四文学将人力车夫奉为道德楷模,也与"改良国民性"的启蒙主题存在悖论。     

魏晋的鹦武赋与当时文士的英才情结

自汉末祢衡为《鹦鹉赋》 ,魏晋时期继作者十余人。细加分析 ,此种现象的发生 ,固有模拟习练、较技竞才的成分 ,更重要的原因则在于 :当时文士因鹦鹉的聪慧 ,而以之为英才的象征。魏晋乃崇尚英雄的时代 ,文士更往往以英才自居 ,遂形成借鹦鹉以抒写其英才情结的风气。     

基于SEM和B-Z反应的集成供应链合作创新机制与动态演化研究——集成供应链关系质量视角

随着供应链与互联网、物联网深度融合,集成供应链企业间合作创新成为企业创造新模式、开拓新市场的重要路径。为揭示在集成供应链环境特征影响下,集成供应链企业间合作创新中集成供应链集成度、知识协同能力与合作创新绩效之间的作用机制,基于复杂系统理论,借鉴B-Z反应模型,在运用SEM模型对集成供应链企业间合作创新静态机制实证研究基础上,进一步构建三维Logistic动态分析模型,探索集成供应链企业间合作创新动态演进机制。结果表明:集成供应链集成度和知识协同能力对集成供应链企业间合作创新绩效有显著正向影响;集成供应链形成初期,集成度对合作创新绩效的影响效果更为明显;长期而言,在不同集成供应链关系质量作用下,知识协同能力的作用举足轻重,提高知识协同能力有利于合作创新绩效持续提升。     

信息传播及其生命周期对移动商务价值链运行的影响研究

为了研究信息传播及其所处生命周期阶段对移动商务价值链中各参与者价值分配的影响规律,设计了每个参与者属性、行为以及agent之间的互动规则,建立其价值链的多agent模型,并基于此建立复杂网络下信息在用户中扩散的多agent模型,对每个用户agent的信息传播和接收行为进行分析,从而对模型进行改进。利用Anylogic 6.5构建仿真模型,并进行仿真实验,利用SPSS对仿真结果进行统计分析,研究模型中各个参数的改变对价值分配的影响效果,依此归纳出各参与者提高价值的策略。     

离散复镜像理论对近地电偶极子的应用

对近地电偶极子赫芝矢位中的索末菲积分,仅用 Prony 法,对其被积函数分式部分进行指数函数逼近,可得到近地电偶极子的一串离散镜像,而这类积分就可看作这些镜像在观察点的解。采用此方法大大节省了计算时间,所得结果与沿实轴数值积分结果吻合很好。对索末菲积分在实轴上可能遇到的奇异点,采用分部积分法消去之,避免了给数值积分带来的麻烦。     

Quadratic subspaces and construction of Bayes invariant quadratic estimators of variance components in mixed linear models

Gnot et al. (J Statist Plann Inference 30(1):223–236, 1992) have presented the formulae for computing Bayes invariant quadratic estimators of variance components in normal mixed linear models of the form where the matrices V _i , 1 ≤ i ≤ k − 1, are symmetric and nonnegative definite and V _k is an identity matrix. These formulae involve a basis of a quadratic subspace containing MV ₁ M,...,MV _k-1 M,M, where M is an orthogonal projector on the null space of X′. In the paper we discuss methods of construction of such a basis. We survey Malley’s algorithms for finding the smallest quadratic subspace including a given set of symmetric matrices of the same order and propose some modifications of these algorithms. We also consider a class of matrices sharing some of the symmetries common to MV ₁ M,...,MV _k-1 M,M. We show that the matrices from this class constitute a quadratic subspace and describe its explicit basis, which can be directly used for computing Bayes invariant quadratic estimators of variance components. This basis can be also used for improving the efficiency of Malley’s algorithms when applied to finding a basis of the smallest quadratic subspace containing the matrices MV ₁ M,...,MV _k-1 M,M. Finally, we present the results of a numerical experiment which confirm the potential usefulness of the proposed methods. Dedicated to the memory of Professor Stanisław Gnot.     

The Role of Knowledge Bases in Complex Product Systems: Some Empirical Evidence from the Aero Engine Industry

In this paper we argue that the virtual corporation as understood in current management literature does not hold as a universal model throughout various industrial sectors. Complex product systems industries show peculiar features in terms of product characteristics, innovation dynamics and strategic and management options that may render the virtual corporation model inapplicable.The paper begins with a contrast between the simplistic neoclassical approach to the interpretation of the concept of knowledge and the more in-depth evolutionary view. The former understands knowledge as information and its production process and outcomes as easily decomposable. Based on this, advocates of virtual corporation claim the viability of outsourcing strategies based on simple economic factors. The evolutionary approach, on the other hand, considers knowledge as a system of processes deeply rooted in their contexts of production. Tacitness and non-decomposability of the knowledge production processes are highly emphasised in this view. In the light of this contrast and relying on a study of the aero engine industry we reinterpret the notion of virtual corporation showing its limits.     

The Retirement Syndrome:: The Psychology of Letting Go

This article analyzes a problem that can be described as the retirement syndrome. In exploring the difficulties many leaders face in letting go at the end of a full career, it reviews a number of the barriers to exit: financial, social, and psychological. It looks at the physical and psychological effects of aging, in the context of retirement; examines the experience of nothingness that single-minded careerists often feel after retirement; describes the talion principle, a subliminal fear of reprisals; and discusses the ‘edifice complex,’ the wish to leave behind a legacy. The article concludes with suggestions as to how individuals and organizations can develop more effective and humane disengagement strategies.