装备维修备件需求预测模型研究

准确的备件需求预测是合理有效地进行备件保障各项工作的基础,在综合分析考虑备件消耗影响因素的基础上,建立了备件需求预测模型。该模型可用于备件的管理决策,提高备件保障率。     

利用全站仪的超大型船舶尾半船落墩工艺研究

描述全站仪技术辅助超大型船舶在尾半船状态下坞内移位座墩的操作过程,并对其难点和重点进行分析研究。     

一种适用于凸轮类零件磨削加工的方法

针对凸轮类零件加工中存在的问题,从加工工艺角度出发,本文提出了一种适用于该类零件磨削加工的恒线速加工方法,并给出了其数学模型。通过实例证明,采用这种加工方法,磨削效果良好     

Platoons of connected vehicles can double throughput in urban roads

Intersections are the bottlenecks of the urban road system because an intersection’s capacity is only a fraction of the maximum flows that the roads connecting to the intersection can carry. This capacity can be increased if vehicles cross the intersections in platoons rather than one by one as they do today. Platoon formation is enabled by connected vehicle technology. This paper assesses the potential mobility benefits of platooning. It argues that saturation flow rates, and hence intersection capacity, can be doubled or tripled by platooning. The argument is supported by the analysis of three queuing models and by the simulation of a road network with 16 intersections and 73 links. The queuing analysis and the simulations reveal that a signalized network with fixed time control will support an increase in demand by a factor of (say) two or three if all saturation flows are increased by the same factor, with no change in the control. Furthermore, despite the increased demand vehicles will experience the same delay and travel time. The same scaling improvement is achieved when the fixed time control is replaced by the max pressure adaptive control. Part of the capacity increase can alternatively be used to reduce queue lengths and the associated queuing delay by decreasing the cycle time. Impediments to the control of connected vehicles to achieve platooning at intersections appear to be small.     

Crash analysis at intersections in the CBD: A survival analysis model

Enhancing the safety level of urban roads especially in CBDs is paramount. Due to a large number of intersections in what is usually a grid road system in the CBDs, we investigate crashes occurring in and around an intersection. The question of interest in this study is: does the nature of crashes at intersections differ from those of the roads at midblock? Stated more precisely, considering the intersection as a reference point, does the distance to the reference point (i.e. midblock locations on the roads) correlate with different types of crashes compared to that of the intersection? A right answer can lead traffic engineers and safety auditors to propose different safety measures at intersections and the midblock locations. As a pilot study, we collected the last 9 years crash data of the CBD of Melbourne, Australia. For the first time, we employ Survival Analysis models -including Exponential, Weibull, and Log-logistic- to investigate a space-dependent phenomenon (i.e. accidents at proximity to the intersection). Of the outcome, highlights are: (i) police presence at busy intersections during busy night outs and weekends highly improves the pedestrian safety (ii) raised crossings at midblock locations lower likelihood of crashes of pedestrians as well as cars, (iii) lighting conditions at intersections must be watched and kept at a high level. (iv) Severity, likelihood, and location have no known association with the level of congestion. In other words, safety is first, always and everywhere. The results can be of interest to traffic authorities and policy makers in reinforcing traffic calming measures in the cities. The codes developed in this study are made available to the research community to be used in further studies.     

浅谈特殊阶段工程质量管理

本文主要讲述在工程施工中，对于雨季、交叉作业期，收尾阶段等特殊时间的工程质量管理，强调管理的系统性及一致性，目的在于服务于工程的总体目标。     

基于ISO13584开放式零件库开发模式研究

给出ISO 13584零件库标准体系的具体内容．提出了Browse/Server零件库开发模式，研究了零件库的总体结构及各部分功能．对服务器端零件库组成结构进行了深入研究；对客户端的基于用户CAD系统的几何编程接口给出两种可行的实现方法。     

工艺基准对FULLER同步器锥环机加工精度影响的研究

同步器锥环是FULLER变速箱的关键零件，其材料为铁基粉末冶金材料，机械加工工艺性比较差，通过对铁基粉末冶金材料组织特性和加工性能的分析，研究加工工艺基准对加工精度的影响，确定合理的工艺基准和工艺路线保证零件加工精度，降低废品率。     

老龄散货船安全探讨

从散货船的受力特点、老龄散货船常见的损坏形式、老龄散货船在大风浪中的操纵、运输精矿粉、日常管理等几个方面来探讨一下老龄散货船的安全问题。     

Prediction of Stabilization of Ship in Random Wave

In this paper we show thc method of energy in part with which we can get the model of random wave,and predict theroll motion of unstabilized ship and stabilized ship using the wave model.The control parameters of fin stabilizer are determinedaccording to the performance index. The simulation of the system is also made in this paper. The comparison of the simulationwith real ship indicates that the method can be used in the prediction of roll motion of a stabilized ship in random wave.