格区间值Fuzzy集的分解定理(Ⅰ)

对格区间值Fuzzy集作了进一步的研究,分别给出了[λ1,λ2]、(λ1,λ2]、[λ1,λ2)、(λ1,λ2)上的下截集、上截集、下重截集和上重截集的新的定义及一种新的闭区间与格区间值Fuzzy集的运算,并给出了与此相应的四条重要的分解定理.     

不规则物流园区功能区块布局模型与算法

物流园区功能区块的合理布局对于降低物流成本、提高物流作业效率有重要意义.传统的研究主要建立在假定物流园区是矩形的理想情况下,本文基于栅格数据结构,构建了以运输成本最小为目标的不规则物流园区功能区块布局的集合划分模型,并引入了栅格图像矢量化技术,用于提取布局形成后的图像拓扑结构,获得路网信息,然后设计了基于割树技术的变邻域搜索算法进行求解.最后以某物流园区为例,通过MATLAB编程计算得出布局方案,验证了本文模型和算法的有效性.     

行人立体过街设施及“第二套步行系统”的合理设置

目前交通问题已经是每个城市,特别是一些大城市不得不面对的严峻问题。虽然城市交通规划已经逐渐走向成熟,但是尚处在发现问题、解决问题的层面,尤其是很多交通规划只注重车辆交通的问题,而忽视了与之相关的行人交通及行人的横向交通对机动车流的影响,道路过街处人车矛盾尤其突出。“人车分离,立体过街”将成为行人过街的主要方式。该文阐述行人立体过街交通设施的规划,介绍“第二套城市步行系统”的概念,并深入地研究其存在的优越性和必要性。     

Dynamic performances of an innovative coupler used in heavy haul trains

An innovative structure for a heavy haul coupler with an arc surface contact and restoring bumpstop is proposed. This coupler has a small lateral force at a small yaw angle and a limitable yaw angle to ensure an allowable coupler lateral force under intense compressive force. The main structural characteristic of the combined contact coupler is a lateral movable follower with an appropriate friction coefficient of 0.06–0.08 and a slide block with a single freedom of longitudinal movement. In order to verify and simulate the performances, a multi-body dynamics model with four heavy haul locomotives and three detailed couplers was established to simulate the process of emergency braking. In addition, the coupler yaw instability and wheel set lateral forces were tested in order to investigate the effect of relevant parameters on the coupler performances. The combined contact coupler is suitable for heavy haul train for a good dynamic performance.     

基于SolidWorks的大型成套装备的快速设计

快速设计是企业在全球化激烈竞争中保持领先的重要手段,文中探讨了基于Solid-works软件实现大型成套装备的快速设计方法,可供同行参考.     

数据挖掘技术在高校学生成绩分析中的应用

数据挖掘是数据仓库技术中的重要技术之一,也是计算机行业中发展最快的领域之一,它使数据库技术进入了一个更高级的阶段,并迅速扩大成为一个独立的领域。在讨论目前高校教学中存在问题的基础上,简单介绍粗糙集理论及数据挖掘技术。以高校学生成绩为例,提出基于粗糙集理论的数据挖掘技术在高校学生成绩分析中应用的解决方案。     

基于粗集理论的交通流丢失数据补齐方法

为了解决交通检测器检测到的数据存在丢失的问题,提出了一种基于粗集理论的丢失数据补齐方法。利用检测到的交通流数据构造信息系统,通过计算扩充可辨识矩阵,并对其进行多次完整化分析,实施丢失数据的补齐,并采用英国南安普敦市的实际检测数据对算法进行了验证。研究结果表明:同一时间段,当仅有一个属性数据丢失时,粗集理论的补齐精度较高,绝对相对误差较小,基本保持在0～5%之间;当不同属性的数据同时丢失时,补齐精度较低,绝对相对误差甚至高达20%;当所有属性数据全部丢失时,补齐精度非常低,可视为无法实现补齐。可见,粗集理论是一种补齐少量丢失数据的有效方法。     

Observing individual dynamic choices of activity chains from location-based crowdsourced data

The existing efforts on studying human mobility and activity using location-based crowdsourced data mainly focus on obtaining the activity chain pattern in a region at an aggregate level. To observe individual dynamic choices of activity chains, this paper presents a data-driven approach to estimating individual-specific activity chain set and corresponding choice probabilities for a given person over a 24-h period using crowdsourced data from location-based service apps. We detect an individual-specific stochastic activity set using a contextual-parcel data analysis. Based on the time geography theory, we refine a space-time bicone concept to construct an activity-travel space-time-state network from the stochastic activity set. These space-time bicone constraints define a set of potential activity choices to reduce the search space of activity location and duration choices. We construct an activity state transition graph from the space-time-state network and calculate a Markov matrix for activity choice probabilities. Furthermore, we calculate the probabilities of activity chain choices using the Markov matrix. We also visualize individual-specific activity chain set in a space-time-state network to show the dynamic choices of individual daily mobility and activity. We demonstrate the proposed approach through conducting numerical analyses using crowdsourced data from location-based service apps - Foursquare and Twitter to construct individual-specific activity choice sets and corresponding choice probabilities.     

KZ4A型机车车轮强度计算和轮对模态分析

采用有限元软件对KZ4A型交流传动电力机车的车轮静强度和疲劳强度进行计算,计算结果表明车轮强度满足要求。同时对轮对的模态进行了分析,得到了轮对的固有振动特性。     

东秦岭隧道平导快速施工机械设备配套模式

本文介绍了东秦岭隧道平导快速施工所采用的机械配套模式及其取得的良好效果 ,对长大隧道机械配套模式进行探讨 ,为类似工程提供经验和借鉴。