组合运输的优化调度

对多车场情况的非满载的小货运量运输问题进行了分析 ,提出采用组合运输方式可以提高车辆的使用效率 ,进而构造了由分组和连接构成的序列优化启发式算法 ,并用实例进行了验证.     

居民出行链、出行方式与出发时间联合选择的 交叉巢式Logit模型

为刻画出行链、出行方式与出发时间的联合选择行为,选取出行耗时、出行费用及个人与家庭属性等作为效用变量,以出行链选择子集合、出行方式选择子集合和出发时间选择子集合的组合作为模型的选择项,构建基于广义极值(GEV)理论的交叉巢式Logit模型,为方便对比,同时构建3种结构的传统NL模型。利用2010年北京市居民工作出行的小样本调查数据,对模型参数进行估计和检验,并进行弹性分析,分析效用变量的改变对备选方案选择概率的影响。参数估计结果表明,交叉巢式Logit模型具有比NL模型更优的统计学特征,并发现当效用变量改变时,选择者最先变更其出发时间,然后是出行方式,最后才考虑改变其出行链结构。直接和交叉弹性分析表明,与简单链的小汽车出行者相比,复杂链的小汽车出行者对出行时间与出行费用的敏感性较低。研究结果可以为制定和评价交通需求管理政策提供依据。     

面向高速网络连接记录管理的高效哈希表

针对高速网络环境下连接记录管理的性能需求,提出了一种改进的高效哈希表PRH-MTF(伪随机哈希-移至最前).首先在定义输入关键字即连接标识符的基础上,通过选择适当的运算符,设计了高效鲁棒的哈希函数PRH.为有效解决哈希冲突,根据网络数据流局部性特点,应用MTF启发法,改进了传统的链式冲突解决方法.以分组火车模型作为数据包到达模式,分析了PRH-MTF哈希表的算法复杂度,推导出了平均查找长度.最后通过实际高速网络数据流和模拟攻击的方式,对PRH-MTF哈希表进行了实验评估.实验结果表明,PRH-MTF哈希表在查找性能和抗攻击能力等方面均优于传统的简单排序哈希表.     

圆型经编机垫纱轨迹探讨

本文介绍了圆型经编机的编织原理和垫纱特点,并用几何作图和数学推导的方法探讨了该机垫纱阶段的经纱断面轨迹方程,为分析其垫纱可靠性以及确定结构参数提供了依据.     

处理稀疏矩阵的C语言链式三元组表法

综合了三元组表法和链表法的优点，利用Ｃ语言中指针和结构的灵活性，提出了一种链式三元组表法，该法能高效地处理各类问题中高阶稀疏矩阵的运算，效果显著．     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining, the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

管理复杂模型体系的面向对象方法

从面向对象方法基本原理和向面对象编程的技术特征出发，阐明所建应用软件系统中的模型对象、类及相应类层次结构和类组合结构，使系统具有表现真实世界复杂系统结构的能力。系统通过消息传递在模型程序执行中实现对操作的调用机制，使之在面向用户问题选择和执行求解策略方面有很强的适应性。这一点对于强调人机交互和解题协作的智能决策支持系统至关重要。给出了用Ｃ＋＋实现的模型对象系统及消息传递机制。     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

南北方老年人出行链选择行为对比

为研究中国南北方老年人出行行为之间的差异,以老年人出行链为研究对象,将老年人出行链分为简单出行链和复杂出行链两种基本形式.基于北方城市东营市2011年的居民出行调查数据和南方城市恩平市2013年的居民出行调查数据,运用二项Logit模型对南北方老年人出行链选择行为进行建模分析,同时考虑个人属性、家庭属性以及出行链属性对老年人出行链选择的影响.模型分析结果表明,个人属性均对南北方老年人出行链选择影响不显著,出行链的出行时间对老年人选择简单出行链产生负影响,家庭月收入、家庭是否拥有小汽车对老年人复杂出行链选择产生负影响,家庭是否拥有自行车对北方老年人简单出行链选择产生正影响.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models,this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the seirice chain,also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to imprwe the functionality and performance of such system will be included.