A Heuristic Approach for Antenna Positioning in Cellular Networks

The antenna-positioning problem concerns finding a set of sites for antennas from a set of pre-defined candidate sites, and for each selected site, to determine the number and types of antennas, as well as the associated values for each of the antenna parameters. All these choices must satisfy a set of imperative constraints and optimize a set of objectives. This paper presents a heuristic approach for tackling this complex and highly combinatorial problem. The proposed approach is composed of three phases: a constraint-based pre-processing phase to filter out bad configurations, an optimization phase using tabu search, and a post-optimization phase to improve solutions given by tabu search. To validate the approach, computational results are presented using large and realistic data sets.     

Industrial petrochemical production planning and expansion: A multi-objective linear programming approach

This paper considers a strategic model planning for the petrochemical industry. It concerns with the expansion in a firm producing multiple products in several regions of a country. The expansion of the existing facilities and the new ones are considered. It also exists a large amount of interdependencies among the firm’s products, because the output of one particular plant can be used as an input to the production of another plant in the same or different regions and to satisfy the final demand. The decision makers involved in the planning process should identify several objectives. Then, multiple objective programming is used for making trade-offs among the economic and operational factors considered. To define the interval criteria weights into the model we utilized the Analytic Hierarchy Process to bring them closer to the decision makers preferences. This work was sponsored by the Institut National Polytechnique de Toulouse, France, when the author was Associate Professor at the Département Génie des Systèmes Industriels.     

Optimal Base Station Positioning and Channel Assignment for 3G Mobile Networks by Integer Programming

In this paper, discrete mathematical programming approaches are used to solve the frequency allocation and cell site selection problem in an integrated setup. Both CDMA (code division multiple access) and FD/TDMA (frequency/time division multiple access) technologies will be important for 3rd generation mobile systems. If all users share the same bandwidth, base transmitter stations should be placed such that a maximum of traffic can be carried at low interference rates. The expected traffic is represented by spatially scattered weighted nodes. The problem to select an optimal set of base station locations from a given pool of configurations is formulated as an integer linear program and solved by combinatorial optimization methods. For systems which employ FD/TDMA schemes, the cell site optimization process depends on the assignment of channels. We suggest an integrated linear programming approach to solve both objectives in a single planning step. Because of the problems' tremendous complexity, special branch-and-bound procedures are developed as exact and approximate solution methods. An examples is given for a typical urban scenario with base transmitters below roof tops.     

Advances in two-dimensional GC with glass capillary columns

A versatile two-dimensional gas chromatograph is described, consisting of 2 separate ovens, one intermediate trap, an auxiliary inlet, and the necessary hardware to effect off-line switching according to the principle of Deans. The unit has been designed for use with high resolution glass capillary columns. The performance of individual instrumental components was critically evaluated. Results showed that low dead volume glass to metal connections were required in the manifold and detector lines to minimize extra-column effects. The mass of the intermediate trap must be low to allow rapid heating. Operational parameters are discussed and examples of some applications are shown.     

长江三角洲国际性城市群发展战略研究

国际性城市群的建设是我国城市在下世纪参与国际竞争的重要战略 ,以沪宁杭为中心的长江三 角洲城市群是我国参与 21世纪全球城市间国际竞争进而发展成为国际性城市群的主要代表 ,既分工明 确 ,又联合协作 ,是长江三角洲地区各主要中心城市实现国际性城市群战略的基本保证.     

我国政府规划价值观的历史考察

从历史视角对我国政府的规划价值观进行系统剖析,指出我国政府规划价值观混杂着政策价值观、政治价值观、组织价值观和意识形态价值观,表现为鲜明的泛公共利益化特征,不但激化了公权力与私权利的冲突,而且对城市规划本身造成了不良影响. 城市规划权力来源于政府行政权威,政府集权制的规划决策模式是规划价值观泛公共利益化产生的主要原因. 城市规划体制转型首先要正视政府的规划价值观问题.     

面向UPMIS的控规数据批量转换方法及实现

控规数据向ArcGIS平台数据转换并入库是城市规划管理信息系统（UPMIS）建设的一项基础性工作.针对分析控规数据转换为ArcGIS平台数据存在的问题,提出了一种高效的控规数据向ArcGIS平台数据批量转换的方法,并结合ArcGIS VBA和Python脚本开发工具,实现了上述方法.测试实验表明,该方法自动化程度高、实现简单、处理效率高.     

200MW非再热双抽供热机组变工况计算及工况图的绘制

工况图在热电厂的设计和运行中具有广泛的用途。本文根据引进型双抽非再热200MW供热机组的技术特点，通过编程在纯凝汽工况、单抽工业抽汽工况、单抽采暖抽汽工况和双抽供热等典型变工况计算的基础上，完成了当新蒸汽负荷、工业抽汽负荷和采暖抽汽负荷发生改变时的变工况计算，并绘制了该机组的运行工况图．     

Global facility network design in the presence of competition

We study the facility network design problem for a global firm that is a monopolist seller in its domestic market but faces local competition in its foreign market. The global firm produces in the face of demand and exchange rate uncertainty but can postpone localization and distribution of the output until after uncertainties are resolved. The competitor in the foreign market, however, enjoys the flexibility of postponing all production activities until after uncertainties are resolved. The two firms engage in an ex-post Cournot competition in the foreign market. We consider three potential network configurations for the global firm. Under a linear demand function, we provide the necessary and sufficient condition that one of the three networks is the global firm’s optimal choice, and explore how the presence of foreign competition affects the sensitivity of the global firm’s design to various cost parameters and market uncertainties.     

中外城市战略规划编制比较

对国内的广州，南京，杭州三大城市的战略规划编制进行了分析，并与西方一些发达国家的城市战略规划编制进行了比较．提出中外战略规划在编制内容、成果、期限等方面存在着相同点和不同点，提出研究中外战略规划对中国传统总体规划改革具有多方面的启发和指导意义．