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161.
�й����ܽ�ͨϵͳ���۷����о�   总被引:1,自引:0,他引:1  
文章是国家“十五”科技攻关重点课题的部分研究成果,分析了ITS在国内外的发展现状以及存在的差异,指出在我国研究ITS 评价的必要性;进一步基于ITS 及其项目评价的特点与难点分析研究,应用霍尔三维结构构筑了ITS评价的三维框架,提出了面向对象的ITS评价方法,以及成本效益分析方法和成本效果分析方法,并讨论了各自的实用性。最后分析了ITS 评价的未来发展趋势,指出实验交通工程学在ITS 评价中的重要作用。  相似文献   
162.
针对舰船作战系统软件复杂性增加以及设计与集成难度的增加,本文介绍一种应对复杂系统研发需求的基于模型的系统工程方法,并阐述需求分析、功能分析及体系架构设计3个阶段的设计流程。最后以典型水面舰艇作战系统体系架构的设计为例对该方法的应用进行验证。经过验证,证明该方法与基于文档的系统设计方法相比具有设计准确的特点,能提高系统设计质量,值得大范围推广;在方法和工具推广上需要结合本单位质量体系要求进一步完善。本文所建模型使用到了IBM公司Rhapsody工具中的Harmony SE套件。  相似文献   
163.
Most previous works associated with transit signal priority merely focus on the optimization of signal timings, ignoring both bus speed and dwell time at bus stops. This paper presents a novel approach to optimize the holding time at bus stops, signal timings, and bus speed to provide priority to buses at isolated intersections. The objective of the proposed model is to minimize the weighted average vehicle delays of the intersection, which includes both bus delay and impact on nearby intersection traffic, ensuring that buses clear these intersections without being stopped by a red light. A set of formulations are developed to explicitly capture the interaction between bus speed, bus holding time, and transit priority signal timings. Experimental analysis is used to show that the proposed model has minimal negative impacts on general traffic and outperforms the no priority, signal priority only, and signal priority with holding control strategies (no bus speed adjustment) in terms of reducing average bus delays and stops. A sensitivity analysis further demonstrates the potential of the proposed approach to be applied to bus priority control systems in real‐time under different traffic demands, bus stop locations, and maximum speed limits. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
164.
中国内河航运发展的机遇与挑战   总被引:3,自引:1,他引:2  
论述了内河航运的优势和我国内河航运的现状,分析了我国发展内河航运的优势和劣势,研究了我国现阶段发展内河航运面临的机遇和挑战。提出了加快实现船舶标准化、打通高等级航道网中的瓶颈、沟通水系、开辟新的入海通道、科技创新、解决关键技术问题、形成水资源综合利用的有效协调机制等应对措施。  相似文献   
165.
随着《高等学校会计制度》的实施,高等学校财务制度得以落实,学校的财务管理工作产生重大的改变,高校的会计制度将更加客观合理.本文通过对高校新旧会计制度的比较,分析新会计制度变化要点,针对性地提出实施新制度的对策措施.  相似文献   
166.
A rapidly growing body of empirical evidence has linked improved ecological performance of social–ecological systems (SES) with better compliance with rules governing human activities. Researchers have proposed several key factors that motivate an individual to comply with resource use rules, including deterrence, social pressures, moral inclinations, and perceived legitimacy of rules and responsible authorities. Much of the research on compliance proposes causal mechanisms at the individual human level, but few studies test causal paths with empirical data particularly at the site level. This study tested a proposed pathway for explaining overall compliance rates and ecological performance in SES using data from structured surveys of community members, key informant interviews, policy documents, and coral reef surveys at marine protected areas (MPAs) and their associated human communities in the wider Caribbean. Findings indicate that compliance and other active MPA management interventions positively affect ecological performance, and site-level contextual factors (level of community development and being part of a political network) positively influence significant predictors of overall compliance rates, which include active MPA management and enforced punishments.  相似文献   
167.
For non-linear systems the estimation of fatigue damage under stochastic loadings can be rather time-consuming. Usually Monte Carlo simulation (MCS) is applied, but the coefficient-of-variation (COV) can be large if only a small set of simulations can be done due to otherwise excessive CPU time. The reason is that the fatigue damage estimation is very sensitive to the largest values from the simulations. The paper suggests the additional use of the First Order Reliability Method (FORM) to get a better estimation of the tail in the distribution of the estimated fatigue damage and thereby reducing the COV. For a specific example dealing with stresses in a tendon in a tension leg platform the COV is thereby reduced by a factor of three.  相似文献   
168.
基于认知地图的地铁空间导视系统优化分析   总被引:1,自引:0,他引:1  
在认知心理学理论背景下,分析了乘客进入地铁地下空间的心理行为及感受。通过地铁导视系统与认知地图的搭建,剖析完善的地铁空间认知元素,并以此为设计对象,对地铁导视系统中乘客方向感缺失等问题作出一些具体分析与优化。  相似文献   
169.
Traditionally, the design of mooring lines and risers of floating production systems (FPS) has been performed separately, by different teams, employing uncoupled analysis tools that do not consider the nonlinear interaction between the platform hull and the mooring lines and risers. Design processes have been focused on fulfilling the design criteria of the respective component (mooring/riser) alone, with few or no consideration to the other component, and little interaction between the design teams. Nowadays the importance of employing analysis tools based on coupled formulations is widely recognized, and analysis strategies have been proposed to consider feedback between mooring lines and risers within their respective design processes.In this context, this work details a proposal of one single and fully integrated design methodology for mooring systems and risers for deep-water FPS. In this methodology, the design stages of both risers and mooring lines are incorporated in a single spiral, allowing the full interaction of different teams; mooring design implicitly considers the riser integrity, and vice-versa, leading to gains in efficiency and cost reduction.Different analysis strategies are employed, taking advantage of uncoupled and coupled numerical models. The models generated at the initial/intermediate design stages can be reused in subsequent stages: simpler models are used in the initial stages, and more refined models are gradually introduced, to reach an ideal balance between computational cost and accuracy of results. In the advanced stages, the exchange of information between mooring/riser also allows the definition of criteria for the selection of governing/critical loading cases to be revised and verified in detail. This leads to the reduction of the original loading case matrix, allowing a feasible use of time-consuming fully coupled analysis.Results of a case study illustrating the application of some of the main processes of the methodology are included.  相似文献   
170.
依据ITS理论与系统工程思想,在分析城市轨道交通特点的基础上,提出城市轨道智能交通系统(UMITS)的概念,并对UMITS的基本构成进行了论述.对UMITS体系中综合监控系统(ISCS)的功能与结构进行了论述,对旅客向导系统(PIS)的服务内容与功能重新进行了定义.  相似文献   
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