排序方式: 共有87条查询结果,搜索用时 15 毫秒
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散货船共同结构规范应用探讨 总被引:1,自引:0,他引:1
对散货船共同结构规范(CSR)在船舶结构设计应用中的若干问题进行了分析,并结合散货船实船的设计,对应用CSR设计与以往常规设计的结果进行了对比,阐明了在CSR应用中应注意的问题。 相似文献
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This paper presents a trajectory clustering method to discover spatial and temporal travel patterns in a traffic network. The study focuses on identifying spatially distinct traffic flow groups using trajectory clustering and investigating temporal traffic patterns of each spatial group. The main contribution of this paper is the development of a systematic framework for clustering and classifying vehicle trajectory data, which does not require a pre-processing step known as map-matching and directly applies to trajectory data without requiring the information on the underlying road network. The framework consists of four steps: similarity measurement, trajectory clustering, generation of cluster representative subsequences, and trajectory classification. First, we propose the use of the Longest Common Subsequence (LCS) between two vehicle trajectories as their similarity measure, assuming that the extent to which vehicles’ routes overlap indicates the level of closeness and relatedness as well as potential interactions between these vehicles. We then extend a density-based clustering algorithm, DBSCAN, to incorporate the LCS-based distance in our trajectory clustering problem. The output of the proposed clustering approach is a few spatially distinct traffic stream clusters, which together provide an informative and succinct representation of major network traffic streams. Next, we introduce the notion of Cluster Representative Subsequence (CRS), which reflects dense road segments shared by trajectories belonging to a given traffic stream cluster, and present the procedure of generating a set of CRSs by merging the pairwise LCSs via hierarchical agglomerative clustering. The CRSs are then used in the trajectory classification step to measure the similarity between a new trajectory and a cluster. The proposed framework is demonstrated using actual vehicle trajectory data collected from New York City, USA. A simple experiment was performed to illustrate the use of the proposed spatial traffic stream clustering in application areas such as network-level traffic flow pattern analysis and travel time reliability analysis. 相似文献
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介绍了装卸时间的基础知识,及其与远洋运输实务中应用的容易混淆的几类时间的区别,阐述了在英国法下有关装卸时间在法律上的基本原则,尤其是在金康租约下对装卸时间的规定为实务中的操作提供了参考,最后着重指出了在实务中的应注意的问题。由于我国对这方面没有法律上的明确规定,且有关操作受国际海运经济一体化的影响比较大,所以理论阐述的比较少,实务比较多,希望借此能够对我国海运装卸操作能起到一点儿参考作用。 相似文献
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在蛙泳的实践教学中,对学生容易产生的、常见的错误动作原因进行分析,并采取了相对的纠正措施,取得了比较好的实效。 相似文献
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共模故障(COMMON MODE FAULT,CMF)广泛存在于复杂系统中,研究如何对系统中可能引发共模故障的故障状态进行识别、提出预防措施、降低共因故障发生概率,成为当今可靠性安全性领域重要的研究方向。共模故障分析(COMMON MODE FAULT ANALYSIS,CMFA)是一种用于复杂系统可靠性、安全性和风险性评价的方法,是故障模式与影响分析和故障树分析的补充,此方法可以用来检验系统各组成部分之间是否满足独立性要求,确定共模故障条件下对系统失效的概率。通过共模故障分析方法在某型民机起落架应用过程的分析研究,为今后此分析方法的应用提供参考。 相似文献
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介绍了软件工程领域中面向对象分析的基本原理与方法,并以一个工厂进货管理系统的分析过程为例,阐述了面向对象的需求分析的3个过程,从而使读者了解如何利用面向对象分析的方法进行系统分析,取得问题域中对象及对象间的关系,最终建立起问题域中模型的方法. 相似文献
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唐小平 《铁路工程造价管理》2014,(4):1-3
工程定额是编制投资估算、设计概预算的重要依据,也是合理确定工程投资的基础。但在已建工程定额使用中存在执行工程量计算规则存在偏差、定额套用与施工条件(或施工方法)不适应、执行概预算编制办法不合规等主要问题。通过对主要问题的分析,并提出几点想法和建议,以促使新一轮定额编制和修订更加科学合理,与设计更好地匹配,使用更加适当和准确。 相似文献
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