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1.
Optimization design and experimental research for space intelligent structurecapacity, high efficiency and low pollution. Estimating URT network scale is the key to ensure the scientificity and feasibility of its construction. The existing studies on rational scale of URT network have not dealt with the interaction of supply and demand. This paper describes the establishment of a system dynamics model of rational URT network scale determination, considering the interaction between URT construction and city social economic development as well as the dynamic equilibrium of capital supply and traffic demand, and the verification of the model validity by applying it to the case of Wuhan City’s URT construction. 相似文献
2.
A weighted time-based global hierarchical path planning method is proposed to obtain the global optimal path from the starting point to the destination with time optimal control. First, the grid- or graph-based modeling is performed and the environment is divided into a set of grids or nodes. Then two time-based features of time interval and time cost are presented. The time intervals for each grid are built, during each interval the condition of the grid remains stable, and a time cost of passing through the grid is defined and assigned to each interval. Furthermore, the weight is introduced for taking both time and distance into consideration, and thus a sequence ofmultiscale paths with total time cost can be achieved. Experimental results show that the proposed method can handle the complex dynamic environment, obtain the global time optimal path and has the potential to be applied to the autonomous robot naviga- tion and traffic environment. 相似文献
3.
Wind energy is one of the fast growing sources of power production currently, and there is a great demand to reduce the cost of operation and maintenance. Most wind farms have installed supervisory control and data acquisition （SCADA） systems for system control and logging data. However, the collected data are not used effectively. This paper proposes a fault detection method for main bearing wind turbine based on existing SCADA data using an artificial neural network （ANN）. The ANN model for the normal behavior is established, and the difference between theoretical and actual values of the parameters is then calculated. Thus the early stage of main bearing fault can be identified to let the operator have sufficient time to make more informed decisions for maintenance. 相似文献
4.
Randomness plays a major role in the interpretation of many interesting traffic flow phenomena, such as hysteresis, capacity drop and spontaneous breakdown. The analysis of the uncertainty and reliability of traffic systems is directly associated with their random characteristics. Therefore, it is beneficial to understand the distributional properties of traffic variables. This paper focuses on the dependence relation between traffic flow density and traffic speed, which constitute the fundamental diagram （FD）. The traditional model of the FD is obtained essentially through curve fitting. We use the copula function as the basic toolkit and provide a novel approach for identifying the distributional patterns associated with the FD. In particular, we construct a rule-of-thumb nonparametric copula function, which in general avoids the mis-specification risk of parametric approaches and is more efficient in practice. By applying our construction to loop detector data on a freeway, we identify the dependence patterns existing in traffic data. We find that similar modes exist among traffic states of low, moderate or high traffic densities. Our findings also suggest that highway traffic speed and traffic flow density as a bivariate distribution is skewed and highly heterogeneous. 相似文献
5.
刘继承 《重庆大学学报(英文版)》2005,4(2):90-95
1 Introduction 1 A great deal of models have been studied on the subject of Diffserv, including static and dynamic pricing schemes. In the case of dynamic pricing, the network administrators adapt the link price to the bandwidth changes; In static pricing, the price is set based on the analysis from the historical data , and it is impossible to react to the changes in the demand or traffic load of the network. However, this scheme is easier to implement. Generally, there always exists an equi… 相似文献
6.
For the realtime classification of moving vehicles in the multi-lane traffic video sequences, a length-based method is proposed. To extract the moving regions of interest, the difference image between the updated background and current frame is obtained by using background subtraction, and then an edge-based shadow removal algorithm is implemented. Moreover, a thresholding segmentation method for the region detection of moving vehicle based on location search is developed. At the estimation stage, a registration line is set up in the detection area, then the vehicle length is estimated with the horizontal projection technique as soon as the vehicle leaves the registration line. Lastly, the vehicle is classified according to its length and the classification threshold. The proposed method is different from traditional methods that require complex camera calibrations. It calculates the pixel-based vehicle length by using uncalibrated traffic video sequences at lower computational cost. Furthermore, only one registration line is set up, which has high flexibility. Experimental results of three traffic video sequences show that the classification accuracies for the large and small vehicles are 97.1% and 96.7% respectively, which demonstrates the effectiveness of the proposed method. 相似文献
7.
1IntroductionSoftwaretesting means a process of analyzing a soft-ware item to detect the difference between existingand required conditions,that is,bugs,and to evaluatefeatures of the software item.It accounts for a largepart in the cost of software development andmaintenance[1].In order to reduce its cost,there hasbeen much research on automating this work.It in-cludes automating test case generation,test-driving,regression testing and testing process management.Usually,the way of testing so… 相似文献
8.
Helen Corkill 《美中教育评论》2008,5(1):1-8
Higher education in the United Kingdom is currently undergoing major changes. In the foreseeable future, it will also undergo farther change. The nature of these changes can be attributed to several key areas-government demand for change, industry demand for change and student demand for change. The UK, like many other major economies and not for the first time in recent history, is having to face the implications of severe skills shortages in its workforce, coupled with the increasing competitiveness of more globalised workforees and workplaces. A recent major government report has set out the country＇s skills agenda until 2020 and UK higher education is starting to wrestle with the implications of these changes, some of which challenge the traditional preserves of university education. This paper will focus on the implications of these skills shortages and the impact that is having on UK higher education. In particular, reference will be made to the impact of the new 2 years vocational Foundation Degrees, to the shift from supply-led to demand-led higher education, the increasing integration and tensions of work-based learning and to the accreditation of Continuous Professional Development （CPD） within an academic framework. This paper presents one story of the growing and changing relationship between higher education and industry. 相似文献
9.
Environmental problems have received a great deal of attention in recent years.In particular,CO2 emissions worsen global warming and other environmental problems.The transport sector accounts for 20% of the total CO2 emissions.Therefore,the CO2 emission reduction of the transport sector is of great importance.In order to reduce emissions effectively,it is necessary to change the distribution and transportation processes.The purpose of this study is to minimize both the transportation costs and CO2 emissions during transportation.Our model considers a transportation scheduling problem in which loads are transported from an overseas production base to three domestic demand centers.The need for time-space networks arises naturally to improve the model.It is possible to know the distance carriers are moving,and also consider the timetables of carriers during transportation.Carrier choice,less-than carrier load,and domestic transportation among demand centers are considered as the three target areas to reduce CO2 emissions during the distribution process.The research model was formulated as a mixed integer programming （MIP） problem.It achieves cost reduction,and will contribute to improvement of the natural environment. 相似文献
10.
Erlin Yusof Norazah Abdul Rahman Azizah 《美中教育评论》2008,5(1):52-60
Collaborative learning involves students working together to aid their learning and is considered an effective method to implement learning goal. However, it involves complicated processes such as have inconvenient assistance to manage the increasing demand for information and support extension of interaction and how to activate collaboration interaction and communication between different types of interactions. A collaborative learning model based on agent can improve learaing effectiveness and give good impact to learning process. This paper discusses the definition, classification and roles of agent to support collaborative learning interaction in E-learning. It overviews the rapidly use of agents to support collaborative learning and describes the types of interaction and communication tools to enhance interaction between all participants. We identify three types of major agents used in collaborative learning interaction; interface agent, information and internet agent, and collaborative agent. 相似文献
11.
交通用地的高效利用与城市可持续发展 总被引：2，自引：0，他引：2
城市交通用地的高效利用,对于城市的可持续发展至关重要。新时期以来,我国城市化进程日渐加快,同时,城市交通用地和城市交通道路状况也有所改善。但还存在诸多问题:一是仍无法满足日益增长的交通需求;二是道路建设的规划和设计被动保守,道路体系结构和空间布局不尽合理;三是不完善的城市交通系统导致道路利用效率低下。要解决这些问题,除了宏观上在城市土地利用规划中贯彻交通负荷最小化的原则以外,强化交通规划的重要作用,积极推进交通需求管理,加强技术支撑体系建设和政策引导,完善交通法律法规建设以及加强遵章守法宣传教育,是实现交通用地高效利用的根本途径。只有做到了这些,才能为我国城市可持续发展提供保障。 相似文献
12.
一种公交网络最佳出行路线选择算法 总被引：1，自引：0，他引：1
随着城市公交网络的扩展,选择合适的出行路线越来越重要.本文提出一种以最短出行时间、最少换乘次数、最小出行费用为目标的公交路线选择算法.在北京公交网络的试算结果表明了该算法效率高. 相似文献
13.
慕威 《中国科教创新导刊》2011,(31):39-40,42
本文在对城市轨道交通人才需求调研分析的基础上,对城市轨道交通运营管理专业职业岗位能力进行了分析,并在此基础上分析专业能力与课程设置的对应关系,构建了课程设置框架体系,为城市轨道交通运营管理专业的专业标准与人才培养方案建设奠定了基础。 相似文献
14.
15.
岳永荣 《河北北方学院学报(社会科学版)》2008,24(5):50-52
分析了经济全球化背景下世界交通运输业在需求、结构及管理方式方面的变化和未来世界交通运输业发展过程中将会出现的三种趋势,并据此得出结论：为适应经济全球化及世界交通运输业发展变化的新趋势,中国的交通运输增长方式必然要从粗放型向集约型转变。为此,应从提高交通运输资源配置效率和资源利用效率入手,充分发挥市场和政府两方面的作用,重点解决提高交通增量投资效率和存量交通资产利用效率两方面的问题。 相似文献
16.
随着机动车拥有量迅速增加和城市土地迅速开发,安阳市面临的交通需求压力越来越来大。对建设项目进行交通影响分析,并逐步将其纳入城市规划报建程序势在必行。借鉴国内外的交通影响分析研究成果,系统地总结了交通影响分析的基本思想、阈值、管理程序和主要内容,最后给出了安阳市开展交通影响分析工作的一些建议。 相似文献
17.
“交通规划”场景式案例教学模式研究 总被引：1，自引：0，他引：1
交通规划是交通工程专业核心课程,理论性强、侧重于工程实践应用,常规教学方式效果不是很好。场景式案例教学以传统案例教学为基础,将知识体系有机地与现实场景联系起来,让学生身临其境地参与完成学习任务、提高实践能力和创新能力。交通规划场景式案例教学模式,是选择适当的典型工程案例,根据教学内容与进度安排、知识点重要度与关联性等进行再加工组织,按照实际交通规划的步骤:"交通调查—交通需求预测—交通规划应用"这一主线来设计教学体系,达到实现知识传授与学生创新技能培养相结合的目的。 相似文献
18.
随着中国汽车工业的迅猛发展,人们对汽车的依赖性逐渐增强,随之而来的就是更大的交通风险。面对日益严重的交通违规现象,相关部门的处罚措施略显乏力。文章试图以无赔款优待模型尝试一种新的方法来减少交通违规次数和事故处理成本。 相似文献
19.
石超峰 《咸阳师范专科学校学报》2008,(2):1-5
目前,交通运输定价和电力污染问题在我国引起社会的广泛关注。许多学者对交通网络问题做了大量的工作,但对电力污染管理问题,国内的研究成果不多,而且大多做定性研究。这两个问题的数学模型都可以归结为交通网络平衡问题。虽然国外对交通网络平衡问题研究了几十年,但其研究背景主要是欧美国家的交通运输和电力污染问题。本文综述了电力燃煤税和动态交通网络的国内外研究进展,提出了一些有待于研究的新问题。 相似文献
20.
利用SOA技术,基于JBI构建ESB对降低信息集成的难度和成本,缩短信息集成的实施周期、提高信息集成的性能会很有帮助.并且在进行交通信息的集成上,不是简单地把集成的各个子系统提供的数据简单糅合在一起,而是可以通过交通信息集成模型,形成综合的交通业务信息,产生新的交通信息服务.而这些新的信息服务反过来又可能增强集成子系统的业务功能,从而通过集成实现了交通业务功能的提升. 相似文献