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71.
Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for ...  相似文献   
72.
正自适应AUTOSAR为实现车辆ECU软件的更大灵活性打下了坚实的基础。这些系统是可扩展的,是全自动和联网驾驶方向的重要一步。自适应AUTOSAR不是替代经典AUTOSAR,它的优势在于2种标准的巧妙结合。自动驾驶对车辆内部E/E架构提出了更高要求。自动驾驶功能需要越来越强大的控制单元,且越来越多地相互联网,并与基础设施(如云端系统)联网(图1)。通过使用来自各种车辆传感器以及外部(例如高精确地图资料)的数据,软件可创  相似文献   
73.
Sloshing is relevant in several applications like ship tanks, space and automotive industry and seiching in harbours. Due to the relationship between ship and s...  相似文献   
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75.
In this study, the coupled torsional-transverse vibration of a propeller shaft system owing to the misalignment caused by the shaft rotation was investigated. T...  相似文献   
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77.
城市交通运行安全关乎千家万户,现已成为人们越来越关注的热点,2019年,我国发生的道路交通事故共导致14527人死亡[1],交通事故产生的损失越来越大.公共交通是城市交通的重中之重,其交通安全的社会影响极大.交通事故产生原因受到人、车、道路以及周围环境等多维度因素影响,交通安全规划研究需要围绕以上因素展开.本文以董家口港城为例,多维度探索了公交安全规划的方法,从公共交通的视角剖析了交通事故原因,提出了面向港口城市交通安全治理的综合对策,制定了综合提升方案,为青岛董家口港城交通安全提升做出了积极探索和实践.  相似文献   
78.
The purpose of this paper is to investigate the dynamics of forward freight rate dynamics. We specify our model in a Heath–Jarrow–Morton framework. This model was originally developed for interest rate markets and, in subsequent work, the model has been applied to various commodity markets. We analyse ten years of weekly time charter (TC) rates for a Panamax 65,000?dwt bulk carrier. Our data set consists of 6-, 12- and 36-month TC rates. We use this data to construct, each day, a forward rate function using a smoothing algorithm. We use the smooth data to investigate the factors governing the dynamics of the forward freight rate curve. We find a strange volatility structure in the data. Out results show that the volatility of the forward curve is bumped, with volatility reaching a peak for freight rates with roughly one year to maturity. Also, correlations between different parts of the term structure are in general low and even negative.  相似文献   
79.
Centrifugal forces are commonly created when ships turn, which may cause a ship to capsize in a critical situation. A mathematical model has been developed to optimize the stability coefficients for ship, with the aim to prevent capsizing and to increase ship maneuverability in high-speed water craft. This model can be used to develop algorithms for control system improvement. The mathematical model presented in this paper optimized the use of multipurpose hydrofoils to reduce heeling and the trimming moment, maintaining an upright ship’s position and lessening the resistance via transverse force. Conventionally, the trimming and heeling of a ship are controlled using ballast water; however, under variable sea conditions it is sometimes difficult to control a ship’s motion using ballast water. In this case, a hydrofoil would be more stable and maneuverable than a ballast tank controlled vessel. A movable hydrofoil could theoretically be adapted from moveable aerofoil technology. This study proves the merit of further investigation into this possibility.  相似文献   
80.
In this paper, an investigation into the propagation of far field explosion waves in water and their effects on nearby structures are carried out. For the far field structure, the motion of the fluid surrounding the structure may be assumed small, allowing linearization of the governing fluid equations. A complete analysis of the problem must involve simultaneous solution of the dynamic response of the structure and the propagation of explosion wave in the surrounding fluid. In this study, a dynamic adaptive finite element procedure is proposed. Its application to the solution of a 2D fluid-structure interaction is investigated in the time domain. The research includes: a) calculation of the far-field scatter wave due to underwater explosion including solution of the time-depended acoustic wave equation, b) fluid-structure interaction analysis using coupled Euler-Lagrangian approach, and c) adaptive finite element procedures employing error estimates, and re-meshing. The temporal mesh adaptation is achieved by local regeneration of the grid using a time-dependent error indicator based on curvature of pressure function. As a result, the overall response is better predicted by a moving mesh than an equivalent uniform mesh. In addition, the cost of computation for large problems is reduced while the accuracy is improved.  相似文献   
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