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71.
The performance of most electronic chassis control systems in the past has been optimized individually. Recently, a great research effort has been dedicated to the integration of chassis control systems in an effort to improve the vehicle performance. This involves orchestration of individual control modules so that they can jointly contribute to the enhancement of their control effect. In this research, two integrated control logics for AFS (Active Front Steering) and ESP (Electronic Stability Program) have been developed. Of the two logics, one uses a supervisor that rules over the individual modules. The other logic uses a CL (Characteristic Locus) method, which is a frequency-domain multivariable control technique. The two logics have been tested under various driving conditions to investigate their control effects. The results indicate that the proposed integrated control logics can yield vehicle performance that is superior to that of the individual control modules without any integration scheme.  相似文献   
72.
世界车辆法规协调论坛及其管理协定   总被引:4,自引:3,他引:1  
主要对联合国欧洲经济委员会(UN/ECE)内陆运输委员会(ITC)框架下世界车辆法规协调论坛及其下属的6个工作组,以及所管理的三项协定:1958年协定(车辆结构法规)、1998年协定(全球技术法规)和1997年协定(定期技术检查)等进行论述。  相似文献   
73.
全球卫星导航系统的构成及其比较   总被引:4,自引:0,他引:4  
介绍了全球卫星定位系统、格洛纳斯卫星定位系统、伽利略卫星定位系统和北斗卫星定位系统的构成、优势等基础上,论述了各系统在技术上的比较。  相似文献   
74.
针对车身结构耐撞性能响应具有强非线性的特点,以某车身前部结构轻量化为例,在利用支持向量回归建立近似模型阶段,分析比较了3种常用的试验设计方法对模型精度的影响.结果表明,将均匀设计与支持向量回归相结合最适合耐撞性能近似模型的构造.基于所得最优近似模型进行车身前部结构的优化设计,在保证耐撞性能的前提下,达到减重2.61 kg、实现6.51%轻量化的效果.  相似文献   
75.
虽然美国的道路交通机动化水平非常高,但其安全事故各项指标却远优于中国。这主要得益于美国在道路交通安全研究方面起步早、研究层次较高、基础研究项目较多、且理论与应用结合紧密。为了全面了解美国道路交通安全研究现状,结合统计数据分析了美国的道路交通安全形势及变化趋势,归纳提出了道路交通安全研究的框架模型,并在此基础上介绍了美国道路交通安全研究的主要领域与实践成果以及美国主要的科研机构,同时还介绍了美国目前道路交通安全研究中的几个主要热点。  相似文献   
76.
This study measures urban form as indicators of metropolitan sprawl and explores its impact on commuting trips and NOx and CO2 emissions from road traffic in all metropolitan statistical areas (MSAs) and four groups’ MSAs separated by population in the continental United States. Encompassing all MSAs, the study adds the accessibility factor to four existing factors: density, land use mix, centeredness, and street connectivity. The study establishes multivariate regression models between urban form, commuting trips, and emissions from road traffic while controlling for socioeconomic conditions. The study shows that urban form index and five urban form factors have a statistically significant association with commuting trips, NOx and CO2 emissions from road traffic. In four MSA groups as determined by MSA population size, higher values of urban form factors (i.e., lower sprawl) are statistically associated with more walking commuters. On the other hand, higher values of urban form factors are associated with fewer commuting vehicles per household in large MSAs with the moderate effect, a lower average commuting drive time in medium and small MSAs, and more commuters using public transportation in medium and large MSAs. This study provides an urban form index covering all metropolitan areas in the continental United States by adding another urban form factor, and the findings show that urban form factors have different effects on mode choices, drive time, and emission from road traffic depending on the MSA population size.  相似文献   
77.
The East Sea (Sea of Japan) is a unique marginal sea because it exhibits features of oceanic dynamics of much larger ocean basins. This semi-enclosed basin may be considered as a model or microcosm for understanding of how biological processes and distributions in pelagic ecosystem are interacting with physical processes in highly dynamic ocean regions. This overview summarizes the recent progresses concerning spatial and temporal variability of pelagic ecosystem components form an interdisciplinary point of view. Spatial characteristics of physical environments and biogeography in the region are distinguished mainly by the subpolar front. It was also found that long-term changes in biomass and community structure as well as those in the physical and biological environments are associated with climate variability in the region. We conclude by identifying main needs for the information and researches, particularly regular and long-term sampling, and permanent monitoring if possible.  相似文献   
78.
Nearly 40 years on since its first tentative steps in North America, this article considers whether Integrated Zone Coastal Management (ICZM) in Europe has grown to maturity as a form of governance. The article summarizes the findings of recent research concerning the levels of implementation of coastal management in Europe, with particular reference to the UK experience. A research framework is used to identify the different motivations behind the social actor groups involved in coastal management. The application of this framework reveals four major findings about gaps in implementation: (1) the complexity of responsibilities at the coast continues to prevent agencies from taking a “joined-up” approach; (2) a policy vacuum is constraining implementation from national to local scales; (3) informational obstacles are significant in preventing co-ordination between science and policymakers, and between different sectors; (4) a democratic deficit is preventing implementation in the working practices of coastal stakeholders, with little opportunity in decision making for public comment or local accountability, especially offshore. The article also explores different conceptualizations of the role of coastal management and planning held across Europe, providing an analysis using the Strategic Management literature and the experience of the EU Demonstration Programme on Integrated Coastal Zone Management (1996–1999). Recent arrangements, with the availability of priming funds from the European Commission and emphasis on “pilot” and “demonstration” methods, have tended to encourage a project-based approach to ICZM that may fail to realize long-term objectives. The article seeks to present an analysis of the behaviors of scientists, academics, policymakers, and practitioners, and will be of interest to all those seeking to establish ICZM within the wider system of governance, as supported by the Commission of the European Community (2000) Communication on ICZM (COM 547). Some technical solutions are also offered from the UK experience that will be of use to coastal project officers working at national and regional levels.  相似文献   
79.
Relatively long term time series of satellite data are nowadays available. These spatio–temporal time series of satellite observations can be employed to build empirical models, called satellite based ocean forecasting (SOFT) systems, to forecast certain aspects of future ocean states. The forecast skill of SOFT systems predicting the sea surface temperature (SST) at sub-basin spatial scale (from hundreds to thousand kilometres), has been extensively explored in previous works. Thus, these works were mostly focussed on predicting large scale patterns spatially stationary. At spatial scales smaller than sub-basin (from tens to hundred kilometres), spatio–temporal variability is more complex and propagating structures are frequently present. In this case, traditional SOFT systems based on Empirical Orthogonal Function (EOF) decompositions could not be optimal prediction systems. Instead, SOFT systems based on Complex Empirical Orthogonal Functions (CEOFs) are, a priori, better candidates to resolve these cases.In this work we study and compare the performance of an EOF and CEOF based SOFT systems forecasting the SST at weekly time scales of a propagating mesoscale structure. The SOFT system was implemented in an area of the Northern Balearic Sea (Western Mediterranean Sea) where a moving frontal structure is recurrently observed. Predictions from both SOFT systems are compared with observations and with the predictions obtained from persistence models. Results indicate that the implemented SOFT systems are superior in terms of predictability to persistence. No substantial differences have been found between the EOF and CEOF-SOFT systems.  相似文献   
80.
保险杠是一种具有吸收、缓和外界冲击力,保护轻型卡车前部重要的安全装置。同时保险杠有很强的造型美观功能,是轻型卡车重要的外饰件之一。文章利用有限元计算和分析的方法对某轻型卡车保险杠内板进行瞬态响应分析,并进行结构优化。经过试验台架和道路试验满足设计要求,该方法对今后轻型卡车的保险杠设计有一定的指导作用。  相似文献   
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