整数规划模型在消防站优化选址中的应用

目前我国消防站建设存在数量不足、责任区面积过大、布局不合理等问题,因此引入分阶段消防站选址模型。位置集合覆盖模型和最大覆盖模型均是整数规划模型,分别应用它们进行两个阶段的选址工作。     

基于火灾风险评价理论的城镇消防站选址优化——以山西夏县瑶峰镇为例

构建瑶峰镇消防重点单位火灾风险指标体系,采用层次分析法评判得出瑶峰镇消防重点单位的火灾风险,排序为易燃易爆场所商场、集贸市场公共娱乐场所学校、幼儿园宾馆饭店重要机关高层住宅建筑。以火灾风险性最高的易燃易爆场所为重点消防对象,使用ArcGIS软件和传统消防站布局法,对瑶峰镇进行消防站优化选址。研究结果表明无论4 km2还是7 km2的消防站责任区面积,瑶峰镇城区都需要建设两个消防站,比原有消防站在位置上有很大的变动。在ArcGIS系统中的道路布局图上,可以确切得到新消防站的具体建设位置,为瑶峰镇政府建设新消防站提供优化决策。     

基于GIS的鄢陵县消防站布局优化研究

随着我国城镇化的快速推进,消防站的规划建设与城市扩张式发展的矛盾日益突出。传统的规划方法只偏重于每个消防站责任区达到规范要求的4-7km2的理论要求,而忽视道路阻抗而难以有效到达的问题。本文借助GIS"位置分配"原理,通过最小化设施点数模型、最大化覆盖范围模型和最小化阻抗模型,科学、合理确定消防站的位置和数量,实现了消防站的优化布局。     

中小城市消防站选址模型与算法研究

结合中小城市的各项消防数据,采用负荷距离法作为主要研究方法,将消防责任区划分为多个小区域,以消防车平均行车距离最小作为消防站选址原则,对中小城市各个消防站的选址进行优化和研究.通过地理模型来求解两点之间的几何距离,简化了繁琐的算法,具有明显的优越性和可操作性.选址模型具有良好的可移植性,适用于医院急救站等公共设施的规划建设.     

基于空间句法的城市消防站可达性分析及优化策略

可达性是城市公共服务设施选址布局领域必须考虑的重要因素。本文依据枞阳县消防站布点及路网数据等信息,结合空间句法和缓冲区分析法对城市消防站的全局可达性和局部可达性进行定量测度,揭示了不同时期研究区道路网络的可达性分布的空间形态特征和演变情况,为枞阳县消防站的选址布局及优化提供数据支撑。结果表明：1)研究区内规划道路的全局可达性较现状道路有很大提升,局部可达性有所提升;2)规划道路中的全局可达性较好但未达到1,各空间单元呈离散的模式,与规划的组团式布局相吻合,规划道路中局部整合度和全局整合度较高的路段存在错位现象;3)现有消防站的全局和局部可达性综合表现良好,可成为区域范围内消防力量有效调配的支持基础;4)除现状以外的其他消防站全局、局部可达性均不是很高,尤其是外围组团的消防站与局部可达性较高的路段有明显的“错位”现象。     

城镇消防站布局问题的探讨

消防站布局问题在城市规划中具有重要作用,在考虑消防站覆盖范围和经济条件的情况下,将整个地区的消防站抽象为0-1整数线性规划模型,利用隐枚举法解决消防站的布局问题。具有科学性和合理性,避免了依靠经验选址的弊端。     

基于聚类选址的区域能源系统站网布局优化规划

区域能源系统中能源站选址和管网布局规划是影响区域能源系统经济性的重要因素.综合考虑能源站选址、管网布局与负荷分布的特点,提出了基于聚类和最短路径算法的站网布局优化方法.首先,将最短路径权重作为聚类相似性度量,建立站网布局结构模型.然后以系统年均经济成本最小为目标,构架优化目标函数.最后以实际工程案例进行仿真分析,验证了该方法的有效性.所提出的方法可以对区域内能源站数量、选址以及管网布局进行综合优化,为区域能源系统站网布局规划提供理论参考.     

城市应急避难场所规划布局模型及实证研究——以咸阳市中心城区为例

从数学与空间模型思维角度出发,建立一套适合城市应急避难场所规划布局的方法体系.通过构建GIS分析模型和多目标规划模型,并引入城市规划路网、自然地形条件以及人员第一应急反应等修正因子,对模型进行修正,从而得到城市应急避难场所的具体责任区范围以及人员分配情况.结果表明,通过对各个模型的构建与分析,优化了城市应急避难场所规划布局的个数、位置和具体责任区范围.该模型适用于咸阳市中心城区城市应急避难场所的规划布局.解决了城市应急避难场所人员分配不均衡性及降低了灾害破坏性.同时,应加强防灾减灾预案,结合城市避难通道等进行规划布置.     

火灾风险综合评估在消防站布局规划中的应用

本文通过新旧《城市消防站建设标准》在消防站布局方面有关条文的对比,结合《厦门市消防规划(2004-2020)》修编过程中关于消防站布局规划的制定和思考,对应用火灾风险综合评估进行消防站规划布局提出意见和看法。     

基于min-plus代数可达的城市消防站点配置评估及优化

城市消防站点配置是城市消防规划中的重点问题,城市消防站点从出动到着火辖区的时间是影响消防救援的重要因素.在火灾发生时,为了使消防队能在"3 min"内到达起火点,提出一种基于min-plus代数域上可达的消防站点配置评估及优化的方法.该方法首先将消防网络抽象为一个网络拓扑图,通过改进的Dijkstra算法计算网络最优路径,评估消防网络的"3 min"可达性.然后新增微型消防站优化消防站点配置,将消防站点增添问题转化为一个0-1整形规划问题,并求得"3 min"可达条件下的最优解.实验结果表明,优化后的消防站配置提升了消防站到需求点的可达能力,增加了城市消防站点配置在时间上的合理性,对城市消防规划具有一定的应用价值和决策指导意义.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~