A three level location-inventory problem with correlated demand

This paper considers a three level location-inventory problem where demand across the retailers is assumed to be correlated. We first present a reformulation scheme by which the initial formulation is transformed into a mixed integer conic quadratic program. In addition, we propose a solution approach based on an outer approximation strategy and show the algorithmic advantage of such framework for this class of programs. The results from numerical experiments show that the proposed solution procedure clearly outperforms state-of-the-art commercial solvers. In addition, we show that neglecting the effect of correlation can lead to substantially sub-optimal solutions.     

锦州102国道沥青混凝土路面接缝质量通病治理措施及成果

简要介绍了102国道路面大修工程中沥青混凝土面层接缝的施工控制方法,以及治理接缝这一质量通病所取得的成果。     

On joint railway and housing development strategy

Transit Oriented Development (TOD) with railway service is recognized as a sustainable mode of development for highly dense megacities. In addition to providing safe and efficient transit services, reducing auto dependence and therefore less need for highway expansions, the improved accessibility of TOD influences commuters’ residential location choices and the resultant housing value. Traditionally, statistical approaches have been used to estimate the relationship between railway development and housing value for individual sites. To some degree, TOD has also been studied with integrated land-use transport models. While useful, they lack an analytical framework to study the region-wide impacts of TOD on residential location and travel choices and the resultant land value changes. In this study, the joint railway and housing development strategy is modeled based on a combined equilibrium formulation with the bid-rent process. The problem is formulated as a mathematical program with equilibrium constraints, in which the upper level optimizes the objective for the joint development strategy by deciding on the combination of housing supplies and railway service levels. Analytical results are obtained for a single corridor in a multi-modal transport network, which are further illustrated by sensitivity analyses. A numerical example is constructed to demonstrate the approach and compare with other separate development strategies. The results generally confirm the synergy between railway and housing developments.     

多种产品的本量利分析研究

大多数企业在生产经营中都会同时生产和销售多种产品,因此,有必要探讨多品种产品的盈亏平衡点的计算问题。目前,常用的方法主要有加权平均边际贡献率法、联合单位法和盈亏图法。     

基于ANSYS的装配体的模态分析

基于有限元思想,运用ANSYS软件建立了轴与轴座的三维模型。采用MPC技术实现了两者的装配,对装配体进行了模态分析,并与粘接和一体化结构的模态分析结果进行了比较。研究结果对复杂装配体的模态分析和动力学分析具有一定的指导意义。     

两组耦合节理工况下隧道变形的数值研究

文章以玉山县高竹山隧道的围岩节理特征为基础,采用离散元软件UDEC建立二维计算模型,通过计算不同工况下的拱顶塌落高度值,研究了两组节理耦合工况下节理倾角、间距对隧道变形的影响。研究结果表明,随节理倾角的增大,塌落高度先增大(0°~30°时)后减小(30°~45°时)最后再增大(45°~90°时),且节理倾角为60°时塌落高度计算值与普氏理论值最为接近;当节理间距在0.2~1.0 m范围内时,随节理间距的增大塌落高度呈非线性减小;当间距接近1.0 m时,塌落高度降幅不明显;当间距不大于0.2 m时,计算值与普氏理论值最为接近。     

基于电子商务物流发展的几点思考

伴随着电子商务的迅速发展,物流已经成为制约电子商务发展的瓶颈。文中根据国内电子商务企业与物流企业的交叉渗透发展、联合发展现状,针对性地提出个性物流的补充解决措施,以期实现电子商务与物流的同步协调发展。     

隧道围岩优势节理面统计及其块体稳定性分析

对于节理发育的破碎围岩隧道工程,根据开挖面的节理发育情况对围岩稳定性作出快速判断是至关重要的.文章以宁波象山港大桥接线段的茶园里隧道右线为例,通过对该隧道右线YK21+670～YK21+718段围岩节理发育特征的精细化描述和统计分析,确定了该段围岩的优势节理面,并在此基础上利用赤平投影解析法进行了围岩块体稳定性分析,得出了围岩块体滑移形式及块体的受力状态,并与数值计算结果相互验证,确定了可能发生失稳的块体,明确了加固区域,对有效保证隧道开挖施工安全有重要意义.     

Applying a Mediated Negotiation Framework to Integrated Coastal Zone Management

Conflict is intrinsic to coastal zone management, yet relatively few peer-reviewed studies have examined how coastal managers might apply conflict resolution processes in the coastal zone management (CZM) context. The authors believe that many of these disputes can be addressed by using a structured mediation model that involves face-to-face negotiation with a broad range of stakeholders to build consensus-based agreements for integrated coastal zone management (ICZM). To explore this further, the article examines four questions. First, it examines how CZM literature characterizes conflict and conflict resolution. Second, it looks at how essential principles from the field of alternative dispute resolution and environmental mediation can be best employed in the ICZM context. In particular, it explores the various elements of a stepwise agreement building model, a mediated negotiation process model the authors use in practice that bases its success on a foundation of four principles: representation, participation, legitimacy, and accountability. Next, it details three essential tools used in this process, stakeholder analysis, joint factfinding, and single-text negotiation, that the authors believe to be promising for developing and adopting stable, well-informed, and implementable agreements for ICZM. Finally, the article examines how these structuring principles and process strategies have been used in two recent case studies regarding the management of the San Francisco estuary and its tributaries.     

中国海与西北太平洋波浪长期统计的导算方法

为了满足船舶与海洋工程对波侯数据的需要，本文回顾了以往出版的几种图集资料并分析了其不足之处，着重介绍了当前国际上较新的英国波峰综合模式（NMIMET）和美国海军风浪后报模式（SOWM）及两者的结果图集。为获得中国海与西北太平洋海域更可靠的数据，在对日本气象厅的器测浮标站长期资料的统计结果与相应的船舶报资料按各种方法处理的结果比较基础上，进一步改进了NMIMET模式。这主要是在波高与周期联合概率分布导算方法上，采用一种新的更灵活的联合分布模式以代替原来所用的由Ochi建议的二维对数正态模式；同时对于在模式中需要确定的有关周期的参数，根据新的资料和计算结果对原用的回归公式作出了改进。用改进后的模式导算得到的波高、周期分布与器测浮标站结果更为接近。