Numerical Simulation of Vehicle Behavior during Straight Line Keeping on Undulating Road Surfaces

Numerical design of vehicles having optimal straight line stability on undulating road surfaces requires an accurate vehicle model based on knowledge of the relevant phenomena. Therefore, vehicle behavior on undulating straight roads has been analyzed and modeled. Measurements on a flat road surface have shown that the dedicated vehicle model yields accurate simulation results of the steering response to medium steering wheel angle inputs. In addition, the model has been validated by measuring two vehicle responses during normal driving on an undulating straight road: viz. the responses to the small steering wheel angle input and to the input by the global inclination of the road surface.     

Impact of high occupancy vehicle lanes on carpooling behavior

High occupancy vehicle lanes have become an integral part of regional transportation planning. Their purpose is to increase ridesharing by offering a travel time advantage to multiple occupant vehicles. This paper examines the extent to which an HOV facility increases ridesharing. Using data from the Route 55 HOV facility in Orange Country, California, changes in the carpooling rate on Route 55 are compared to that of a control group of freeway commuters. The analysis shows that the carpooling rate among peak period commuters, and particularly those who use the entire length of the facility, has increased. However, there has been no significant increase in ridesharing among the entire population of Route 55 commuters. Results suggest that barriers to increased ridesharing are formidable, that travel time savings must be large in order to attract new carpoolers, and that further increases in capooling will likely require development of extensive HOV lane systems.     

Union rivalry and crew reform in shipping: A United States—Australia comparison

The national-flag fleets of most of the traditional martitime nations have, in virtually every case, been in decline in the 1980s and 1990s, despite the continued growth of ocean shipping. They have declined in terms of numbers of vessels and numbers of sea-going jobs, although not necessarily in terms of cargo carried. However, a number of those nations have responded to the changed technological and competitive conditions with some success by attempting to adjust crewing and work practices on vessels at sea. Neither the USA nor Australia has been in the forefront of such change. However, considerably more progress has been made in modernizing crewing practices and work rules in the Australian-flag fleet than in the US-flag fleet. There are a variety of reasons for this, inluding government policy. However, it is our argument that one of the principal reasons the US fleet lags behind the Australian fleet in the adoption of modern crewing practices and work rules is the much greater degree of union rivalry in the US shipping industry. In fact, while the degree of fragmentation and rivalry among unions in the Australian flag fleet has declined dramatically since 1980, their US cousins have continued, and in some ways expanded, their pattern of fratricidal behavior. First we shall discuss some of the technological and competitive imperatives that are driving human resource management practices in shipping and the crewing and industrial relations adjustments that are being made around the world to adjust to them. Then we shall indicate how the Australian and US fleets have responded to these challenges. This will be followed by a discussion of unionism in the Australian and US maritime industrics as it has devloped in the last two decades of the twentieth century. Finally, we shall draw conclusions about the impact of different patterns of unionization.     

The effects of chord length and boundary conditions on the static strength of a tubular T-joint under brace compression loading

Non-linear finite element analysis is used to assess the static collapse strength of a sample tubular T-joint configuration subjected to compressive brace loading. Two series of models are used to assess the effects of varying the chord length L, one series having simply supported chord ends and the other having fixed chord ends. It is shown that chord length and boundary conditions can have a significant influence on static collapse loads. The results are discussed in the light of current design procedures.     

北京市铁路噪声特性实例分析研究

通过实际测量及数据分析，认为测量现场昼夜等效声级达到 ７７７ ｄ Ｂ（ Ａ），超过了国家标准；快速列车噪声频谱分布复杂，难以治理；列车鸣笛对铁路噪声超标贡献最大，验证了铁路噪声与列车车速的关系，最后提出控制铁路噪声的建议。     

Provision of accessible transportation alternatives for the transportation handicapped in Taiwan

Four transportation handicapped groups are identified in Taiwan (impaired ambulation, visually impaired, aged, and others) and nine accessible transportation alternatives are proposed. The costs and potential ridership for these nine alternatives in the Taipei area are estimated. Using analytic hierarchy process (AHP) and multicriteria evaluation with qualitative and quantitative data (MEQQD) methods, the most appropriate accessible transportation alternatives for each of the four handicap groups are selected. It is found that the best accessible transportation alternative for the impaired ambulation, the aged, and others would be a demand-responsive lift-equipped specialized van, while half-fare subsidized taxi would be the second-best option. By contrast, the best alternative for the visually impaired would be half-fare subsidized taxi, while conventional bus with broadcast equipment would be the second-best choice.     

British Shipping and World Competition[1] revisited

The object of my book British Shipping and World Competitionwas to answer the question: 'Why has the tonnage of ships registered in the United Kingdom declined from over 45% of the world total in 1900 to about 16% of that total in 1960?'. There was never any normative element to this question, a point which has been much misunderstood. In answering the question, two different methodologies were used. Chapters II through VIII are industrial economic history, whereas Chapters IX through XIV are applied economics. When the two groups are thought of as siblings, not as Siamese twins, it can be seen that the first group has worn rather well, but that the applied economics chapters have a distinctly dated air. Most of this article is concerned with the applied economics chapters, where I try to examine what is said in the book in the light of my subsequent experience and thinking. There is one absolutely gross error in the material. Unfortunately, this is implicitly reflected in the Code of Conduct and in the EC Maritime Regulations. The original answer to the question has been rephrased in the article; I hope this will put to rest the idea that the question was normative in intent. The rephrasing does not alter the answer: the decline which needed to be accounted for can be explained solely in terms of internal constraints. The remainder was a 'natural' result of changing international patterns in resource allocation.     

单只限位开关保护双向极限位置

以前为机械产品配套电气原理图时,碰到需要限位控制时,常用的是在每个运行方向配备一只限位开关,当运行至极限位置时,限位开关就动作切断电源。大家都比较熟悉的LX915船用防水式限位开关,因为要满足船检所规定的外壳IP56的防护等级,所以体积庞大,价格也昂贵。当每台电动机的两     

Law enforcement in the ocean

The combating of the present great variety of criminal activities occurring at sea mainly involves measures to be taken on land, in particular in ports.However, also actual enforcement at sea will continue to play an essential (complementary) role. This article surveys the rules of international law governing law enforcement measures at sea. These rules are complex, because distinctions have to be made between the various jurisdictional zones at sea and between the positions of the flag state, the coastal state and the port state. Traditionally, ships in the high seas (all sea areas beyond a narrow band of territorial sea) were under the exclusive jurisdiction of the flag state. In an increasing number of situations, the coastal state now has law enforcement authority over foreign ships in expanded areas up to 200 nautical miles offshore. But apart from these situations, flag state jurisdiction still prevails beyond the territorial sea. This makes effective law enforcement difficult. In practice, many obstacles can be overcome by making more effective use of the authority of the port state, and by concluding new international agreements providing for specific enforcement systems.