Who's using Biffex? Results from a survey of shipowners

The continued survival of the Baltic International Freight Futures Exchange (Biffex) would certainly have come as a surprise to many critics that were present at its inauguration. In an effort to explain, at least partially, the reasons for its continued existence, this paper presents the results from a behavioural and attitudinal survey of shipowners. Through the analysis of the responses received, the paper attempts to evaluate the degree of success achieved by Biffex in providing shipowners with a powerful, flexible and viable mechanism for hedging their market risk. The results imply that there is great scope for improving the acceptability of the market amongst shipowners, particularly as a hedging tool. In the light of these results, the paper comments on potential future innovations within Biffex and suggests changes in marketing policy that might lead to an increased level of acceptance amongst shipowners. In conclusion, recommendations are made with respect to aspects of Biffex that are worthy of further investigation and analysis.     

Theoretical Analysis of a Semi Active Suspension Fitted to an Off-Road Vehicle

A theoretical analysis is presented to model a hydromechanical, semi-active suspension system, first as a single wheel station and then as fitted to each wheel of an off-road vehicle. Predicted results show that two benefits are obtained by comparison with the equivalent passive system. First, vehicle attitude is controlled for changes in body forces arising from static loads or braking/cornering inputs. Second, a significant improvement in ride comfort is obtained because low suspension stiffnesses can be used.     

Validation of Railway Vehicle Lateral Dynamics Models

The general form of the railway vehicle lateral dynamic predictions seems to have been proven. If wheels are coned, rails are of uniform cross-section, and suspensions are linear, then good predictions can be obtained. If wheels are not coned, and rail sections vary, but the suspension is relatively linear, as in modern vehicles, it is still possible to obtain good predictions of critical speed for flexible suspensions. The situation with “stiff” vehicles remains unproven. In each case dynamic response calculations will be only as good as the knowledge of the track input including the rolling line term. The validity of making calculations to predict critical speeds of very non-linear vehicles has not yet been convincingly demonstrated. Validation experiments for the more difficult case of time history representation suggest the possibility of correct prediction for easily comprehensible vehicles, but even this requires an enormous amount of supportive experimental work.     

Decisionmaking in the motor carrier industry

Distinct discrete decisions made by the same economic actor are likely to be correlated, particularly those decisions involved in transportation demand. These correlations may be due to economic interactions among the decisions, or to heterogeneity, or both. This paper develops an econometric method that can distinguish among these possibilities and applies this method to analyzing motor carrier deregulation. One overall goal of the Motor Carrier Act of 1980, which substantially reduced federal regulation, was to promote greater competition in the industry. Other things equal, the more competition in an industry, the less concentration. However, concentration has been increasing among general freight carriers since deregulation. The positive correlations found between the decisions to acquire broker authority and to be a general freight carrier could be due to joint economies between broker authority and general freight carriage, in which case the two interact as economic complements, or to heterogeneity among motor carrier licensees. In the first case, but not the second, deregulation of broker authority could lead to increased concentration in the general freight sector. Empirically, we find that the decisions are correlated due to heterogeneity, but do not interact. Thus, increased concentration in the general freight sector must be attributed to other causes.     

同侧肾缺血及对侧肾切除时留存肾DNA合成的研究

幼年小白鼠经体内~3H-TdR参入法液闪测定,检测一侧肾缺血及对侧肾切除后留存肾DNA合成的影响。结果表明:肾缺血、肾切除24h后均促进留存肾DNA合成。而一侧肾缺血同时对侧肾切除留存肾脏~3H-TdR参入量升高最明显。并探讨了一侧肾缺血及对肾切除后留存肾的代偿机理。     

"船舶轮机设备运行与管理"多媒体素材库的开发与制作

介绍了船舶轮机设备运行与管理多媒体素材库开发中的制作思路、制作条件、制作技巧、素材的组装与管理等方面，分析了轮机专业课程素材库特点，阐述其广阔的应用前景。     

论我国船员劳务外派法律制度的完善与规范

船员劳务外派是指船员在有关单位的组织下，在外籍船舶上提供操纵控制和管理船舶等项劳务，完成海上运输过程的活动。为完成该项生产活动而订立的合同即船员劳务外派合同。现阶段，我国还没有制定专门的船员法，相关的法律规范还不完善。     

近交系大、小鼠遗传质量的控制

对陆续引进的８个国际标准近交系（ｉｎｂｒｅｄｓｔｒａｉｎ）大鼠和小鼠，通过５年多的繁殖、保种实践，建立了以繁殖指数为选种指标、家系留种的单线修饰保种法；对高血压大鼠首次采用了综合选择指数选种法。通过自体皮肤移植及对碱性磷酸酶－１（Ａｋｐ－１）等１４个生化基因位点检测，未发现遗传“污染”。