迎接STCW‘95公约的挑战

介绍了英国喀里多尼亚ＭａｃＢｒａｙｎｅ公司驾驶员与轮机员的培训模式，并对其进行了分析。     

Finite element analysis of proportional solenoid characteristics in hydraulic valves

Proportional hydraulic valves (PHVs) have remarkable applications in different branches of industry. These valves can control an oil hydraulic system. One of the most important factors affecting a proportional solenoid (PS) is the geometry that affects its magnetic force with respect to its plunger position. Other effective factors include the size of the air gap, the current density and various soft magnetic materials that have different B-H (flux density versus field intensity) curves. Electromagnetic analysis (EMA) is used to enhance the reliability and accuracy of the PS and to reduce the total cost. In this paper, a range of PSs are software package with different air gaps, dimensional parameters, current densities and soft magnetic materials. The magnetic flux density and force are calculated using a finite element method (FEM), and the results are compared with the experimental results of an actual PS.     

Aging characterization of metals for exhaust systems

The mechanical characteristics of four materials used in automotive exhaust systems have been compared after an aging treatment to evaluate the combined effects of thermo-mechanical fatigue and corrosion. For this purpose, an experimental aging procedure has been developed. This procedure is composed of chemical, thermal and mechanical cycles, which are combined and repeated to simulate the actual operating conditions of automotive exhaust systems. Three austenitic steels (AISI 309, AISI 316Ti, and AISI 321) and a nickel-based alloy (Inconel 625) are tested. The results show that Inconel 625 and AISI 309 are less affected by the aging process than the other materials.     

Do mergers and alliances influence European shipping and port competition?

In Europe, ports are confronted with a closer integration in the maritime and shipping industries. The co-operation agreements can take several forms such as alliances and mergers among shipping lines, conferences, involvement of shipping companies in terminal management, and extending interests in inland transport of shipping companies. In this paper we give a brief overview of these different types of agreement and we examine the consequences of this evolution of the market structures in which ports and shipping companies have to operate. More specifically, attention goes to the competitive position of the port in this new environment. It is clear that the role of the port and the port authorities has to be redefined to guarantee that it remains a fully fledged player in this fast evolving integrated market.     

Bregman's balancing method

In this paper we observe that most of the independently discovered balancing methods, used in transportation planning and in other fields, are in fact special cases of a method of Bregman. Examples include the usual Kruithof or Furness method, the Evans-Kirby three dimensional balancing procedure, the Murchland multiproportional balancing procedure, the Osborne or Grad method for preconditioning matrices, the Jefferson-Scott procedure for gravity models with inequality constraints, and the method considered by Macgill for partially constrained gravity models. The convergence of all of these methods follows from Bregman's general result.     

Light rail transit in the United States

In recent years interest in light rail transit has grown substantially in the United States. The concept of LRT is increasingly viewed as a possible answer to the search for a less costly rail transit technology that could reduce America's dependency on the private automobile and put the country on the road to a more secure, self-sufficient energy future. The paper reviews recent LRT developments in four American cities, two of which have undertaken to rehabilitate and upgrade their existing surface street railway systems, and the other two have embarked upon construction of entirely new light rail systems.     

Estimation of gap acceptance parameters within and across the population from direct roadside observation

This paper explores the feasibility of maximum likelihood as an approach to determine the parameters of gap acceptance functions when these functions vary from individual to individual. Specifically, it is shown that it is theoretically possible to estimate the average critical gap of a population of drivers (or pedestrians) and its variance, within and across individuals, from direct roadside observations. Although the Multinomial Probit Model provides a natural theoretical framework for the estimation of these parameters, the model seems not to be statistically estimable for this particular problem. It was shown, however, that if one of the parameters is known, the other two become estimable and a two-stage estimation process that takes into account this phenomenon can be utilized. The technique is demonstrated with the 203-driver data set included in Appendix A. The Multinomial Probit Model can also be used to determine simultaneously the mean critical gap, the mean critical lag (the first gap considered by a driver), and the variances of these. For the data set in Appendix A, the mean critical gap was significantly smaller than the mean critical lag, as one might expect. The techniques proposed in this paper have the further advantage of being statistically efficient with large data sets and of not requiring a panel of individuals to be observed under controlled conditions.     

借助列车运行阻力在线测量测定牵引力和制动力

通过在线求得列车运行阻力而无需直接测量,就可测定列车中机车动车的牵引力和制动力.这是一种获得专利的测量方法.这种测量方法用于动车组时,尤其是动力分散的动车组时有许多优点,它也适用于创新的车辆,例如磁悬浮铁路的车辆.     

Estimation of the Non-Linear Suspension Tyre Cornering Forces from Experimental Road Test Data

The paper discusses the application to real data of an identification procedure based on an Extended Kalman Filter, for estimating the equivalent non-linear suspension tyre cornering forces of a road vehicle from a single standard manoeuvre. In particular, both the steady-state and the dynamic handling characteristics can be evaluated.