Direct Covariance Analysis for the Calculation of Creepages and Creep-Forces for Various Bogies on Straight Track with Random Irregularities

In this paper creep-forces and creepages for an ICE express train coach and an electric locomotive BR 120 of the DB on straight track with random irregularities are investigated. The calculations are made with the multibody program MEDYNA using direct covariance analysis. One of the aims of this article is to emphasize the advantages of the direct covariance method (time domain) compared with the power spectral density method (frequency domain).     

The Institute for Marine Studies, University of Washington

The University of Washington recently (1981) established a College of Ocean and Fishery Sciences which incorporates extant programmes in oceanography, fisheries and other marine resource fields. The Institute for Marine Studies (IMS), organized in 1972 and presently directed by Professor Warren Wooster, is one component of the new college. IMS, a multidisciplinary academic and research unit, focuses on the management and policy issues arising from the many different uses of marine and coastal resources.     

管推进工程管线与土壤互制行为之分析研究

本研究主要是针对非明挖工法中之管推进工法,以有限元素法来仿真分析管推进工程中的相关问题,并且加入了管材与土体表面之间的接触性质来探讨管推进工程中管材与土体的互制行为.本次数值分析包含了物理模型试验与曲线推进工程等两种数值分析模型.在物理模型的数值分析中,考虑开挖面超挖与挤压的两种状况,并且与实验量测数据做比较.而在曲线推进的数值分析中,则建立一般土层中在外侧土体地盘改良前后的两种情况来互相比较,观察改良前后推进过程中观察土体的应力分布情况和地表沉陷量变化,期能将结果回馈到真实的工程设计之上.     

Perceptions of foreign exchange rate risk in the shipping industry

This is an analysis of the impact of exchange rate risk on the performance of major shipping companies from two important maritime nations, Japan and Norway. For the shipping industry, such risk is exacerbated by freight rates fixed in US dollars which must then be converted into numerous other currencies. The appreciation of the Yen against the US dollar has been such that Japanese companies have been impelled to insulate themselves from exchange rate movements by natural hedging. For Norway, where fluctuations of the Krone against the US dollar have been less dramatic, exposure has been maintained, allowing an element of speculation. In both cases the market indicates that exchange rate risk is a significant factor in the determination of corporate performance.     

A methodological framework for a priori selection of travel demand management package using fuzzy MCDM methods

Transportation - A robust and scientific selection of appropriate Travel Demand Management (TDM) measures is likely to ensure that the purpose of their implementation is met. The existing methods...     

Travellers’ perceptions of travel time reliability in the presence of rare events

Transportation - Travellers account for variability in transport system performance when they make choices about routes, modes and destinations. Modellers try to quantify travel time reliability...     

高速铁路车辆车轴的疲劳设计方法(续)

3.4疲劳危险部位设计由于受车轴形状和疲劳磨损影响,压装部位(如轮座和制动盘座)的疲劳强度比其他平滑部位要小。为了提高压装部位的疲劳强度,采用了多种形状和材料的车轴进行统计测试。其压装部位的具体形状如图7所示。轮座和制动盘座处的车轴直径比平滑部位的要大,故采用了一     

Torque control of a vehicle with electronic throttle control using an input shaping method

The shock-jerk phenomenon is usually observed in vehicles with manual transmission systems that are rapidly accelerating, and this phenomenon makes the passenger feel uncomfortable. This phenomenon can be minimized using torque control of the vehicle with throttle-by-wire or an ETC (Electronic Throttle Control) system. In this paper, the drivetrain of the vehicle is modeled to simulate the vehicle behavior, and the control strategy of ETC is studied to reduce shock and jerk characteristics using an input shaping method. The control logic is verified by using vehicle modeling and simulations.     

Development of jacket platform tsunami risk rating system in waters offshore North Borneo

This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3M _w seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US$ 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model.     

Optimization of drying performance considering driving conditions

Compressed air can be used as an energy source for brake systems in medium-heavy and heavy-duty commercial vehicles. The moisture in compressed air, which is due to high temperature and humidity, can be eliminated by using an air dryer. In this paper, drying performance data for a cartridge were obtained and used to develop a drying performance program, to predict the moisture and relative humidity in the air tanks of vehicles. The on-load time, off-load time, air flow, duty cycle, humidity and dew point temperature were calculated according to air consumption. The validity of the program was verified, and it was shown to be able to predict humidity changes in the air tank. The air tank capacity was increased from 100 to 130 to reduce the duty cycle. Therefore, the regeneration rate decreased from 18% to 15%, but the dew point depression temperature (ΔT) remained above 30°C. The duty cycle decreased from 50% to 43%, and the total operation time and power consumption of the air compressor were reduced. In conclusion, fuel savings were obtained by changing the parameters to optimize the system.