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51.
针对海洋平台构件的特点,介绍了钣金展开方法在平台施工、构件制作中的应用.在分析介绍三种钣金展开方法的基础上,通过几个案例进行了说明,并且作了进一步的探讨.  相似文献   
52.
深水铺管船技术研究   总被引:1,自引:1,他引:0  
诸虹 《船舶工程》2011,33(4):8-11
海底管道在海洋石油天然气的运输方面起到越来越重要的作用,但随着铺管海域水深的增加,对海底管道的铺设方法和主要铺设工具——铺管船也提出了更高的要求.文章介绍了目前普遍使用的几种深水铺管船的船型特点及铺管方法,并以ABS规范为基准,详细说明了深水铺管船入级在总体、结构、舾装等方面应达到的各项要求.  相似文献   
53.
道路工程中遇到不良路基时必须经过相应的技术措施处理才能达到技术标准。分析南昌市朝阳洲地区高含水量路基对道路工程的影响,提出不良路基处理的一般技术措施及其注意事项。  相似文献   
54.
An extensive body of literature addresses the income elasticity of road traffic, in which income is typically treated as a homogenous quantity. Here we report evidence of heterogeneity in cross-sectional estimates of the elasticity of vehicle-kilometres of travel (VKT) with respect to income, when household income is disaggregated on the basis of income source.The results are generally intuitive, and show that the cross-sectional income elasticity of road traffic is not homogeneous as is typically specified in transport planning models. We show that in a number of circumstances the cross-sectional elasticity with respect to aggregate household income is of the opposite sign in comparison to more refined estimates of elasticity disaggregated by income source. If further research confirms that the elasticities we report here are causal in nature, neglecting the elemental effects could result in misleading results affecting practical infrastructure-investment and policy decisions, particularly as the mix of income sources shifts (e.g. if, as society ages, pension income increases as a share of all income).These results are of interest to both researchers and forecasters of travel demand, as well as designers of future travel survey instruments; the latter group must decide how to generate data about respondents’ income. Current expert guidance is to collect a single estimate of aggregate income at the household level. Future travel survey design choices will bound the analyses that can be supported by the resulting survey data, and therefore methodological research to re-visit the trade-offs associated with such choices is warranted.  相似文献   
55.
根据电梯工作原理和工作过程,通过设置与电梯工作状态相关的计量及其控制器件,对楼宇交通状况分析和做相关实验,将电梯实际用电情况用数学方法进行计算,合理地将楼宇电梯用电费分摊至电梯使用住户。  相似文献   
56.
机车信号出入库巡更检测系统   总被引:1,自引:1,他引:0  
介绍了一种采用精细电子巡更的机车信号出入库检测系统。从安全性、经济性、可靠性及可维护性等方面,对该系统在机车信号检测上的应用前景进行了分析。  相似文献   
57.
夏乐 《北方交通》2006,(11):52-53
对桥梁健康状况检测的重要性,桥梁健康状况检测的主要背景作了一定的概述。并对目前比较常用的几种桥梁健康状况检测技术如红外热像仪检测技术、光纤传感器检测技术、声探测技术、电磁波探测技术作了综合的介绍。  相似文献   
58.
We report here on how we adapted Interactive Stated Response Methods to use in a self-completion survey of 454 California households to measure the market for electric vehicles in California. Electric vehicles are a novel product and have many features unfamiliar to consumers, in particular their home recharging capability and limited range. Reflexive techniques were designed to draw households into a deeper exploration of the lifestyle implications of electric vehicles than can be done in more typical self-completion surveys, and to stimulate key decision processes previously observed in detailed gaming interviews with 51 households. Reflexive self-completion techniques provide a middle course between typical large sample quantitative surveys and small sample, detailed gaming interviews. One of the benefits of the more intensive techniques was that participants reported finding the surveys interesting and return rates were high for a self-completion approach – over sixty percent. We review previous transportation and sociological methods which inspired our design, describe the design goals and features of our research, and summarize research results pertinent to testing the validity of our approach.  相似文献   
59.
Bonnel  Patrick  Le Nir  Michel 《Transportation》1998,25(2):147-167
Those designing surveys and producing data have always been concerned about its quality. The increasing stringency of the financial constraints which affect public authorities and the increased scope of involvement in the regulation of urban travel has led us to pay even greater attention to the quality of data. This issue is frequently covered in the literature on survey methods. However, comparisons between different survey methods are more rarely conducted. The decision to conduct such an analysis is partly the result of the development of telephone use to the detriment of other survey modes in many countries and also the development of Computer-Aided Telephone Interviewing (CATI) which facilitates the running and monitoring of the survey.This paper examines several aspects of this question in order to compare the performance of telephone and face-to-face interviews. The first aspect is the representativeness of the sample, and therefore relates mainly to the issue of nonresponses and the choice of a sample base. The second concerns the accuracy of the information and involves the choice of a survey area and the recording of all trips, including short-distance travel. Finally, the quality of data is obviously determined by the quality of the responses given by those interviewed.The answers we give frequently depend on the objective of the surveys, which leads us to put forward a table which summarizes the performance of telephone and face-to-face interviews on the basis of the main objective of the survey. Broadly, the telephone seems to be the favoured tool for surveys in the area of transport planning and surveys which aim to provide data for forecasting models, mostly on the grounds of cost. However, face-to-face techniques are often preferred for surveys which aim to discover and analyze the factors which explain individual travel behaviour.  相似文献   
60.
租船运输业务与法律课程专业双语教学调查问卷评析   总被引:1,自引:0,他引:1  
为提高学生英语水平,突出我院办学特色,对管理系国航专业租船运输业务与法律课程双语教学进行问卷调查。对开展双语教学是否有必要、教学质量、教材质量、教师水平、双语授课的比例、教学时数、建议和看法等方面广泛征求学生的意见,大部分学生认为开展双语教学有必要,既提高了外语水平,又提升专业知识和能力。对双语课程教学质量、双语教学的教材、教师的知识水平表示满意;认为双语教学应保证质量,稳步增加。通过问卷调查,也发现学生对教师所讲知识的掌握程度不理想;过半学生未提前预习和课后复习所要讲授的内容。  相似文献   
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