城市出租车打车软件使用率对空驶率影响研究

为了计算在使用打车软件背景下城市出租车的空驶率,将乘客划分为两类,即传统的扬招乘客与使用打车软件的乘客,根据乘客类型特征分别提出了等待时间计算方法,建立了基于乘客等待时间与出租车空驶时间守恒关系的出租车打车软件使用率与空驶率量化关系模型。在城市路网特征及出租车相关运营参数固定的情况下,模型能客观反映城市出租车打车软件使用率与个体空驶率的对应关系。通过算例分析表明该模型具有有效性和可行性,数据分析能较好地反映实际情况,有助于管理部门衡量城市出租车系统的运营效率,也可为打车软件等新型电召服务模式的引导方式提供决策依据。     

基于出租车数据的载客热点与打车热点研究

面对城市出租车高空载率和乘客打车难问题,本文针对出租车司机端和乘客端分别进行载客热点和打车热点的分析研究,提出了一种基于DBSCAN算法的数据处理模型.利用这个模型对北京市182辆出租车的GPS轨迹数据进行处理,提高了数据精度;对于不同的受众,采用K-means算法对数据进行聚类分析,得到相关热点.实验表明,划分目标用户进行各热点的推荐不仅可以有效地为出租车司机提供高概率的载客热点,乘客打车难问题也有了一种可行的解决方法.     

新资讯

正打车软件取消司机端补贴,需求还在市场还在8月10日,快的和滴滴的消息显示,两家司机端实行的现金补贴在8月初正式取消。取消补贴或许不会带来用户数锐减,只要乘客有需求,就会有抓住乘客需求的司机。取消补贴也将让打车软件市场变得更为理性。诺基亚员工反思,不能在安逸中迷失了理想     

基于MapReduce的出租车停泊点智能推荐算法

现有解决打车难问题的研究工作大部分是集中式地调度出租车,且大多方法在单一服务器上运行串行算法分析海量出租车GPS数据,计算量大,会遇到计算时间和计算资源的瓶颈。为此提出一种基于MapReduce的出租车停泊点智能推荐算法,为司机或乘客推荐更容易接到乘客或打到车的地点。算法通过挖掘大量出租车GPS轨迹数据,检测出停泊点,并生成停泊点知识库。再利用推荐模型为司机或乘客推荐最佳停泊点。实验分析了北京市真实出租车GPS轨迹数据,结果表明该算法能有效为司机和乘客推荐出停泊点,且在大数据量下具有较高的效率。     

弹性需求下公交网络系统票价结构的优化

对具有弹性需求的城市公交网络系统票价的合理设定问题进行了研究分析.考虑到公 交收费结构的变化会影响乘客的出行需求量和乘客对路径选择行为,将这一问题描述为一个两 级数学规划问题.上一级问题是寻求收益最大的优化问题,下一级问题是估计乘客在网络上的 流量分布的具有弹性需求的随机用户平衡分配模型.鉴于两级规划问题的非凸性,提出基于灵 敏度分析的启发式算法.最后,给出一个仿真算例说明提出的模型和算法的合理性.     

出租车载客点个性化推荐算法

不同的出租车司机在寻找乘客选取载客点时会有不同倾向,利用三种推荐算法对上海出租车司机载客点选取行为进行分析,根据司机对载客点的喜好程度进行个性化推荐.首先,利用基于用户和基于项目的协同过滤的算法来对出租车司机的载客点进行推荐,利用正确率指标来验证算法,实验证实了这两种算法的可行性;之后,考虑到出租车的载客行为受到时间的影响,在上述两种算法基础上增加了时间因子;最后,利用隐含因子模型（LFM）,将出租车与载客点的共现矩阵进行分解,根据分解所得矩阵进行兴趣度的分析.实验结果证明,三种方法可有效形成推荐,且LFM算法推荐准确率较高.     

城市公共交通时间差别定价模型

为解决城市公共交通出行时间需求不均衡的问题,构建了时间差别费率定量计算与复合城市交通网络流量分配双层规划模型。上层为社会福利最优模型,下层通过非必要性出行系数描述多方式分时段复合城市交通网络随机弹性需求的公交时间差别定价模型。运用遗传算法对模型整体进行求解,下层模型采用综合对角化算法和MSA算法的组合求解算法。最后,设计了一个算例以说明模型应用。结果表明,运用时间差别定价方案比高峰/平峰同一费率定价方案社会福利目标函数高37．1,乘客对平峰时段降低票价的弹性高于对高峰时段增加票价的弹性,实行高峰增加票价同时平峰降低票价的方案效果最为明显。     

一种基于车流量的司乘推荐模型

作为城市交通的基础设施,出租车在日常交通中起着重要作用。随着城市规模的扩大,人们的出行需求不断增加,然而出租车的分布与叫车需求分布之间难以匹配,从而导致打车困难问题的出现,这一现象在大型城市尤其明显。造成打车难的主要原因在于司乘之间信息不能互通,GPS、车联网等技术能够提供车辆位置、运行轨迹等信息,通过对这些信息数据进行处理,可以获得有价值的信息,将其提供至司乘双方能够提升出租车运营效率。现有信息处理方法较为简单,忽略了较多关键影响因素,难以达到理想的效果。因此,本文提出了一种基于出租车轨迹和路网数据来衡量打车难度的出租车流量模型,并通过综合时间、天气等因素对模型进行优化,提升了模型的实用性。基于该模型利用数据挖掘算法抽取有用信息,提供给出租车司机和乘客。最后,本文基于实际出租车数据对模型进行实验验证,结果证明了模型的有效性及实用性。     

基于E-CARGO模型的共乘出行匹配建模与优化方法

共乘出行应用系统通过提高汽车可用座位容量利用率来减少交通拥堵、缓解停车位紧张,提高社会效益和环境效益。司机和乘客的实时匹配和优化技术是共乘系统的核心内容。基于角色的协同（RBC）是一种用于促进组织结构、提供有序系统行为和协调系统内活动的新方法。为了减少乘客和司机的动态实时匹配时间、提高匹配效率,提出结合RBC和环境-类、代理、角色、群组和对象（E-CARGO）模型形式化共乘问题的方法。在资源容量约束和利润收入给定的情况下,对共乘匹配问题进行建模和仿真实验,提高可用座位容量利用率,实现平台收益最大化,资源匹配合理化。实验结果表明,基于E-CARGO模型的形式化方法可以应用于共乘出行匹配问题建模,最优匹配矩阵和时间可以采用Kuhn-Munkres（K-M）算法和Java中的优化软件包（ILOG）解决方案获得。与ILOG软件包算法相比,K-M算法所用平均时间至少减少了21%;当代理规模大于一定数值（大于600）时,算法时间开销急剧增大。     

关于网约车订单分配策略的综述

网约车在人们的日常出行生活中扮演着非常重要的角色,随着时代的发展,越来越多的人习惯于利用手机通过出行平台打车,但有时存在乘客的请求长时间得不到满足、司机长距离空载等现象,这不仅严重地影响了乘客和司机的体验感,还降低了人们的出行效率。如何更好地匹配乘客请求和空载司机需求,一直是出行平台关注和研究的重点问题。对网约车订单分配策略的研究,有助于减少乘客等待时间,提高司机收益,减少司机空载距离,提高资源利用率。首先简述了从乘客发起打车请求到请求订单被响应的完整流程;其次,详细地介绍了在不同派单模式下的订单分配策略;最后,全面地列举了衡量订单分配策略的评估指标。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。