B2C电子商务中带退货的多配送站点车辆路径优化问题研究

研究了一个带退货的多配送站点车辆路径优化问题,建立了求解该问题的0-1整数规划模型,以实现各个配送站点在给他们客户配送货物的同时,沿途取回这些客户的退货,以节约运输成本的目的。设计了一种新的解的表示方法和邻域变换,以此为基础构造出直接求解多配送站点车辆路径优化问题的禁忌搜索算法,在该禁忌搜索算法中首先通过一个启发式算法求得了0-1整数规划模型的一个较好的初始可行解,从而提高了禁忌搜索算法的收敛速度及性能,最后通过例子对禁忌搜索算法及其性能进行了说明。     

How Do Squatters Deal with the State? Legalization and Anomalous Institutionalization in Madrid

Radical and autonomous urban movements like the European squatters' movement tend to resist integration into the institutions of the state, although particular legal and political conditions in each country or city may significantly alter this tendency. In this article, I examine the controversial issue of ‘institutionalization’ among squatters, focusing on the few cases of legalized squats (social centres) in the city of Madrid. Negotiations with the state authorities and processes of legalization are the major forms of institutionalization involving squatters. However, an anomalous kind of institutionalization also emerges once squats, whether legalized or not, become consolidated and socially accepted. For squatting to have a successful impact, then, depends on both the type of autonomy achieved by squatters and the different outcomes of the processes of institutionalization. The case of Madrid provides empirical evidence that: (1) negotiations with state authorities were very frequent among squatters, but most were defensive; (2) the few cases of legalization were due to specific conditions such as the urban centrality of the squats, single‐issue identities, social network solidarity, favourable media coverage, formal organizations working as facilitators and the squatters' leadership of the process. Furthermore, legalized squats in Madrid preserved a high degree of autonomy, self‐management and ties to other radical social movements. In conclusion, both the legalized squats and the squatters' movement in Madrid as a whole, avoided ‘terminal institutionalization’ and, instead, gave shape to a ‘flexible’ one.     

城市空间的生产方法论探析

“空间的生产”是新马克思主义城市学派的核心概念.哈维在发扬“空间的生产”理论并将其用于城市问题研究上具有代表性.其城市空间分析的方法论特点有三:立足于自身问题;自由和富有批判性;阶级分析和文艺分析相结合.国内案例研究反映出微观与宏观、时间与空间尺度结合的重要性.     

中原经济区城乡协调发展评价

统筹协调的城乡发展格局是中原经济区发展战略的内在要求。本文在分析城乡协调发展内涵的基础上,构建了城乡协调发展评价指标体系,并利用相关省份2012年统计年鉴数据对中原经济区各地市城乡协调发展水平进行评价和空间格局分析。结果显示:(1)中原经济区城乡协调发展空间上呈现明显的"块状"分布格局,北方城乡协调水平总体好于南方;(2)不同因子对地级市层次城乡协调发展影响程度与各地级市之间按各主因子的差异程度不具备一致性;(3)县域经济发展是推动城乡系统向高水平城乡协调关系演进的重要动力。     

Price-raising drug enforcement and property crime: a dynamic model

Price-raising drug enforcement suppresses drug use, but it is expensive and may increase property crime. This has led to contradictory recommendations concerning how drug enforcement should or should not be used. We reconcile these recommendations by incorporating the enforcement's effects on both drug use and on property crime within an optimal-control model that recognizes whether convicted drug-involved property offenders are merely incarcerated or whether they receive some form of drug treatment.     

中原城市群生态环境保护的技术整合研究

通过生态工程技术来维护与提高城市群生态环境质量,是未来城市与区域发展的新理念,也是城市群可持续发展的基本支撑。在对中原城市群生态环境的现状问题分析的基础上,对中原城市群的生态环境的技术整合进行了研究。针对当前出现的生态环境问题,运用生态防护林地技术、自然保护区技术、生态园区设计技术、水源地保护技术、市区绿地系统规划技术、文物古迹保护技术、环境影响监测评价技术等进行整合,可为壮大中原城市群地区的生态资源与保障生态安全提供技术支撑。     

考虑物料、产能和客户优先级三重约束的订单允诺管理问题研究

客户订单允诺管理是在市场全球化的背景下．综合考虑各种资源有限性,对客户的订单给予准确的答复．因而具有很好的应用前号。文章对现有客户订单允诺模型做出改进,在供应链资源即物料和产能双重限制下,加入客户优先级约束,通过建立模型求解,给出合理的客户订单允诺机制。文中不仅定性分析客户优先级．而且将客户优先级量化为客户价值来表示,使该订单允诺管理机制更为有效．更有利于企业的长期可持续发展。     

The Vortex of Rights: ‘Right to the City’ at a Crossroads

The right to the city concept has recently attracted a great deal of attention from radical theorists and grassroots activists of urban justice, who have embraced the notion as a means to analyze and challenge neoliberal urbanism. It has, moreover, drawn considerable attention from United Nations (UN) agencies, which have organized meetings and outlined policies to absorb the notion into their own political agendas. This wide‐ranging interest has created a conceptual vortex, pulling together discordant political projects behind the banner of the right to the city. This article analyzes such projects by reframing the right to the city concept to foreground its roots in Marxian labor theory of value. It argues that Lefebvre's formulation of the right to the city — based on the contradiction between use value and exchange value in capitalist urbanism — is invaluable for analyzing and delineating contradictory urban politics that are pulled into the vortex of the right to the city. Following Lefebvre's lead in such an analysis, however, reveals certain limitations of Lefebvre's own account. The article therefore concludes with a theoretical proposition that aims to open up space for further critical debate on the right to the city.     

A fuzzy goal programming approach to analyse sustainable development goals of India

Energy policy, environmental planning and economic development play a key role in sustainable development. Sustainable development requires suitable and strategic policies satisfying multiple and conflicting objectives. Fuzzy goal programming (FGP) is a well-known approach in multi-criteria decision-making for its practical application. In this article, a FGP approach is proposed to analyse environmental, energy and sustainability goals of India by the year 2030 with reference to the key economic sectors of India. The presented model analyses the improvement opportunities, requirement of efforts and implementation of the sustainable development plans. Numerical illustration is also provided for validation and application of the proposed model.