Solution Space Coupling in the Random K-Satisfiability Problem

The random K-satisfiability (K-SAT) problem is very difficult when the clause density is close to the satisfiability threshold. In this paper we study this problem from the perspective of solution space coupling. We divide a given difficult random K-SAT formula into two easy sub-formulas and let the two corresponding solution spaces to interact with each other through a coupling field x. We investigate the statistical mechanical property of this coupled system by mean field theory and computer simulations. The coupled system has an ergodicity-breaking (clustering) transition at certain critical value x_d of the coupling field. At this transition point, the mean overlap value between the solutions of the two solution spaces is very close to 1. The mean energy density of the coupled system at its clustering transition point is less than the mean energy density of the original K-SAT problem at the temperature-induced clustering transition point. The implications of this work for designing new heuristic K-SAT solvers are discussed.     

基于线路“异质性”假设的轴辐式公共交通网络优化研究

特大城市公共交通局部静态拥堵问题日益成为制约公共交通网络运行效率提高的关键。针对这一问题改变线路“同质性”假设,在线路“异质性”假设的基础上,提出了将轴辐式网络设计运用到公共交通领域中来,综合考虑居民采用公共交通方式出行的单位运输可变成本、不变成本、枢纽换乘成本等要素,将枢纽间大型客车干线运输所带来的规模经济效应进行量化,构建了基于单分配、多枢纽、混合式网络结构特征的轴辐式公共交通网络优化模型,旨在多重约束下通过枢纽布局降低网络运输成本,提高公共交通网络站点的可达性。最后根据模拟退火算法对模型进行求解,并通过算例分析与讨论的方式验证了模型的有效性。     

Sequential location—allocation of public facilities in one- and two-dimensional space: Comparison of several policies

The present paper examines the sequential location—allocation problems of public facilities in one- and two-dimensional space under several policies. It is shown that the efficiency loss due to the adoption of a myopic policy is not so large, contrary to common belief, provided that the efficiency can be measured by the total transportation cost of users and by the total capacity of facilities. If the total serving area is sufficiently narrow, then the spatial allocations of optimal solutions in two-dimensional problems can be closely approximated by those in one-dimensional problems.     

Relevant elements of laboratory competence

 The staff of a laboratory, and its pre-conditions in terms of management principles and work procedures, constitute the basis for customer satisfaction including the quality of the results. It is argued here that there is a rather limited core of principles and procedures, the relevant elements of which are essential for "laboratory competence". These elements are treated as part of the requirements in international quality standards, in particular the draft revision of the ISO/IEC-Guide 25. It is suggested that it should be possible to structure them in a more flexible way and to integrate the elements into the ordinary management system of a laboratory.     

多数满意规则的一般陪审团概率及其极限

对于在一陪审团(群体)中,每一个决策者正确判断方案的满意性都具有各自不同概率的情况,建立了陪审团(群体)正确判断方案满意性概率的一般形式的定理.同时,证明了该陪审团(群体)正确判断方案满意性的概率,将随着参与决策者人数的增加趋于它的极限1.     

MassBank: a public repository for sharing mass spectral data for life sciences

MassBank is the first public repository of mass spectra of small chemical compounds for life sciences (<3000 Da). The database contains 605 electron‐ionization mass spectrometry(EI‐MS), 137 fast atom bombardment MS and 9276 electrospray ionization (ESI)‐MSⁿ data of 2337 authentic compounds of metabolites, 11 545 EI‐MS and 834 other‐MS data of 10 286 volatile natural and synthetic compounds, and 3045 ESI‐MS² data of 679 synthetic drugs contributed by 16 research groups (January 2010). ESI‐MS² data were analyzed under nonstandardized, independent experimental conditions. MassBank is a distributed database. Each research group provides data from its own MassBank data servers distributed on the Internet. MassBank users can access either all of the MassBank data or a subset of the data by specifying one or more experimental conditions. In a spectral search to retrieve mass spectra similar to a query mass spectrum, the similarity score is calculated by a weighted cosine correlation in which weighting exponents on peak intensity and the mass‐to‐charge ratio are optimized to the ESI‐MS² data. MassBank also provides a merged spectrum for each compound prepared by merging the analyzed ESI‐MS² data on an identical compound under different collision‐induced dissociation conditions. Data merging has significantly improved the precision of the identification of a chemical compound by 21–23% at a similarity score of 0.6. Thus, MassBank is useful for the identification of chemical compounds and the publication of experimental data. Copyright © 2010 John Wiley & Sons, Ltd.     

再论集中优势兵力原则

针对兰彻斯特平方定律,并结合现代作战的多目标要求,讨论了集中优势兵力原则中关于“优势”的计算问题,给出了具有实践指导意义和可操作性的计算方法.     

基于顾客满意的渠道合作机制研究

将零售商的服务分为短期性服务和基于顾客满意的长期性服务,由于长期性服务对销售量的影响具有滞后性,因此本文建立了多时期渠道动态决策模型.在此基础上分析了三种情况:①制造商对零售商的长期性服务不激励、②制造商对零售商的长期性服务激励和③渠道整合结果表明:如果制造商不对零售商激励,零售商也有长期性服务偏好;如果对零售商激励,那么零售商付出的长期性服务更多,他们的努力程度由零售商利润的贴现系数决定.同时渠道整合时,渠道总利润要优于其余两种情况.制造商对零售商激励时双方的利润都要大于不激励时的利润,渠道整合时双方的利润与他们的分配比例有关.     

乡土中国的现代化—乡村基层治理中的政府和社会

随着中国经济的发展及城市化水平的提高,乡村社会治理结构正在发生巨大的变化,在这一过程中应处理好政府与社会之间的关系,充分实现传统社会资本与现代资源配置机制的互补。研究发现,传统乡村治理结构在当前乡村社会仍然在发挥作用,随着市场化和城市化进程的深入,传统资源配置机制的弊端在逐渐弱化,而其有利的一面依然保持。经济发展进程本身会自动淘汰传统资源配置机制的糟粕,保留其有利的一面。因此,政府可利用传统乡村治理结构中有利的一面,与之良性互动与配合,毋须急于去取代它,但要警惕基层政府的滥权之害。     

公共辩护的摇摆性—罗尔斯政治自由主义转向的内在困境

不少学者试图从公共辩护的视角捍卫罗尔斯从《正义论》到《政治自由主义》的转向。这种辩护有双重任务,一是在多元主义事实的前提下获得稳定性,二是不想放弃普遍性。为完成此双重任务,公共辩护使用的理性观是有争议的康德式实践理性观,由此出现了三个方面的摇摆性。第一,其达成标准摇摆于实然同意与应然同意之间;第二,它对公民道德能力的设定摇摆于高（为了优于一般辩护）与低（为了稳定性）之间;第三,其对多元主义合情理性的认定也是摇摆不定的：根据形成观念的过程,根据观念的持有者和根据观念的内容。困境的根源可能在于反思平衡方法,它要求纳入人们根深蒂固的直觉,而各种直觉之间经常是有冲突的。