Steady-State Curving Performance of Railway Freight Truck with Damper-Coupled Wheelsets

The focus of this paper is on the steady-state curving behaviour of a freight car system with Damper Coupled Wheelset (DCW), where the wheels of conventional shape within an axle are coupled through a damper element. A freight truck model with two DCW and pseudo-car body on curved track is developed to study the influence of wheelset coupler parameter on the curving response and performance. The response is primarily evaluated in terms of wheelset tracking error and yaw misalignment in response to track curvature and cant deficiency. The curving performance is evaluated in terms of slip and flange boundaries. The results in general, indicate that when the value of coupler parameter is reduced, the wheelset response to track curvature increases, and results in flanging and wheel slip on a less tighter curve than those corresponding to conventional rigid axled wheelsets.     

The influence of workplace environment on lung function of shopkeepers working near National Highway in Jalgaon: A note

The inferior ambient air quality was observed near highway passing through Jalgaon urban center. Among the pollutants critical level of particulates are observed at the roadside during May 2003 to April 2004. The shopkeepers working at the highway sides are at high risk of exposure to the air pollution caused by heavy highway traffic. The lung function test of the shopkeepers shows significant decrease in forced vital capacity, forced expiratory volume in one second and peak expiratory flow rate. The regular periodic health checkup and use of nose mask will protect the health of shopkeepers working near National Highway passing through Jalgaon urban center.     

Haplostoma dudleyae sp. nov. (Cyclopoida: Ascidicolidae), parasitic in Eudistoma olivaceum from the Indian River in southern Florida

Haplostoma dudleyae sp. nov. is described and illustrated on the basis of females found in a compound ascidian (Eudistoma olivaceum) collected from the Indian River in southern Florida, USA. Each parasitized zooid has a single female copepod. The egg sacs of the female are paired and, when laid, are almost U-shaped and folded against the dorsal side of the body. Haplostoma dudleyae and two other species (H. canui Chatton and Harant, 1924, and H. humesi Ooishi, 1995) constitute a subgroup within the genus Haplostoma.     

Electronically Controllable Vehicle Suspensions

The basic functions which suspensions must perform are described and categories of controllable suspensions based on the required amount of control power are defined. The kinds of devices which can be used in controllable suspensions are discussed as well as several basic control philosophies. Finally, fundamental theoretical and practical limitations in suspension performance are indicated.     

A review of the road safety strategy in hong kong

Since the mid-1990s, the effectiveness of road safety measures in Hong Kong has been weakening. Six administrations in Australia, California, Great Britain (GB), Japan, New Zealand and Sweden are selected to help review the road safety activities in Hong Kong. Nine main components of the road safety strategy, including vision, objectives, targets, action plan, evaluation and monitoring, research and development, quantitative modeling, institutional framework and funding are summarized from the road safety strategies of these overseas administrations and compared to that of Hong Kong. It is found that Hong Kong's road safety activities have to be restructured to make significant improvement. In the future, a new approach structured by the nine different road safety components is recommended. The lessons learnt can be generalized to smooth the progress of other administrations at the Intermediate Stage towards the Advanced Stage of road safety development by using the short-, medium- and long-term approaches.     

Relaxation approaches to large scale bus driver scheduling problems

The bus driver scheduling (BDS) problem in a transit company consists of establishing, at minimum cost, a list of work-days in which a driver is assigned to each bus in the given time-table and all clauses of the union contract are respected. In this paper we present a general mathematical programming formulation for the BDS problem. Because, in general, the problem is too large to be solved directly, we introduce a relation of the problem and three different solution approaches. Computational results obtained on real life problems indicate that mathematical programming techniques can solve the BDS problem efficiently.     

Variation of whitecap coverage with wave-field conditions

Field observations were carried out at a sea observation tower to investigate how whitecap coverage on the ocean surface responds to wave-field conditions. Images of whitecaps were taken for every 4 h or 7 h in the daytime using a 3CCD digital video camera fixed at 14 m elevation, and they were stored automatically in a hard disk video recorder at a time interval of 1 s. The determination of whitecap coverage was made by means of a digital image processing. The 1/3 power of whitecap coverage increases linearly with increasing the 10-m neutral wind speed. On the basis of the deflection angle between the propagating directions of wind waves and swell, wave-field conditions are classified into four cases. The present results show that whitecaps are produced most actively under the condition of the pure windsea and they tend to be suppressed by the presence of swell. It is difficult to find a certain relation between the deflection angle and whitecap coverage. Whitecap coverage also increases with the wave age in the same wind-speed conditions.     

International comparison of market risks across shipping-related industries

This paper compares the behaviour of shipping and shipping-related company stock returns to reveal whether systematic risk differs from the average in the market and across sub-sectors of the maritime industry. Following an extensive collection of information through a postal questionnaire survey, 108 publicly listed shipping and shipping-related companies, across stock exchanges of the world, are classified by sector according to their core business activity. The Capital Asset Pricing Model (CAPM) is employed for the period 1996-1999 to model stock returns and measure sector βs (systematic risk). Stock returns over the period are mostly negative. The systematic risks of the Drilling and Offshore sectors are significantly higher than those of all other sectors, but are not different from each other. There is no significant difference between the systematic risks of the Bulk, Tanker, Container and Ferry sectors. The systematic risk of the Cruise sector lies somewhere between these two groups. There is no difference in the systematic risk of companies that diversified within shipping or shipping-related industries when compared to companies that diversified in other areas. Over all companies in the sample, βis lower than the market average, and so are the βs of the Ferry, Tanker, Bulk, Container and Yard sectors. Only the βof the Drilling sector is statistically higher than one, while the Cruise, Diversified and Offshore sectors are statistically one.     

Control system design for an individual signalized junction

The traffic signal settings for a single road junction have been often evaluated by mathematical programming techniques. This paper proposes a new approach to the problem which allows all the regulation variables to be incorporated into a Binary-Mixed-Integer- Linear-Programming model. This general model permits some of the limitative assumptions involved in other formulations of the problem based on the stage matrix to be removed. The model can be easily solved obtaining a fast computation of the globally optimal control system design. A detailed treatment is given for the particular structure of the mathematical programming schemes obtained by considering delay minimization, capacity reserve maximization, or cycle time minimization as the objective.