The U.S.S.R.: Ocean Use and Ocean Law

This paper is an attempt to illustrate the stance of the Soviet Union in the law of the sea debate in the light of Soviet ocean activities. The paper has two sections. First, it examines the range of Soviet ocean activities. The considerable extent of Soviet ocean use underscores the importance which the Soviet Union places on the law of the sea debate and its consequent active participation in the process of international negotiation. Second, the paper considers the published record of the Soviet Union in the United Nations seabed debate. In seven years of debate the United Nations General Assembly and the Ad Hoc and permanent Seabed Commities and sub-Commities have generated a considerable body of documantation reflecting the public policy of over one hundred States concerning the law of the sea. Soviet expressions of opinion alone cover more than five hundred pages of documentation. Specific Soviet positions can be considered within two ganeral preferences: the protection of traditional freedoms of the high seas and opposition to ocean control by either coastal States or by an independent international ocean authority. The paper shows how these preferences and the specific Soviet negotiating positions defend and promote the maritime interests of the Soviet Union.     

A Study in Port Planning: The Example of Mina Zayed

The correct number of berths that a port should provide is solved by a model which minimizes the total port usage cost in terms of the costs of berth provision and the costs accruing to ships from time spent in the port. This model is then applied to Mina Zayed in the Arabian Gulf as an aid to future planning, and from different sets of cargo forecasts an optimal stategy is derived using a game-theoretic approach.     

The treatment of capital costs of vehicles in evaluating road schemes

There are two ways in which new road schemes may influence capital expenditure on vehicles. Firstly, by improving utilisation of existing vehicles, the size of fleet needed to perform a given volume of work may be reduced. This will clearly reduce the amount of capital tied up in motor vehicles at any point in time, and to the extent that vehicle life is determined by age rather than mileage run, will also yield savings in terms of investment in new vehicles. Secondly, by generating additional road traffic, road schemes may lead to an increase in the stock of vehicles in use.This paper argues that the current treatment of vehicle depreciation and interest charges in U.K. cost data fails to allow correctly for either of these items. Errors of logic occur in the way in which the capital stock of vehicles is valued, and in the fact that certain overheads are ignored even when fleet size changes. Moreover, the empirical evidence supporting the current partitioning of depreciation into overhead and running cost components, and the assumption of constant hours in service after an increase in journey speed seems of doubtful validity.An alternative method of calculating vehicle capital costs, based on the concept of annual capital charge, and making explicit the assumptions with respect to vehicle utilisation, is advocated, and the sensitivity of results to the view taken of the latter is demonstrated by means of specimen calculations.     

Transport planning and the policy-modelling interface

Evidence of the inability of transport models to elucidate policy is cited and reasons for this weakness are then suggested.Attention is drawn to the fundamental changes in both opinion and policy currently taking place. There is less concern with accessibility per se and rather more concern with the provision of adequate or minimum accessibility for certain social groups. More emphasis is placed also on the environmental aspects of transportation.The implications of these changes are outlined. It is not at all clear that the need to adapt and up-date models is appreciated widely enough. Finally, it is considered whether fundamental changes in methodology may help to make transport models more responsive to policy needs.     

Nonlinear Attitude Dynamics of Twin Cycle with Feedback Control

The nonlinear attitude dynamics of a twin cycle under output feedback control is studied through bifurcation analysis. Two cases are considered. One assumes no slip and the other assumes small slip. The double zero bifurcation is found to occur in both cases but with different bifurcation sets. Among them heteroclinic orbits are found in both cases and a limit cycle in the second case. The region of feedback gains for stability is obtained. Large negative feedback gains are found necessary to assure stability of the twin cycle. Finally, the tire effect is studied and it causes the distortion of the bifurcation sets.     

Analytical Tire Models for Dynamic Vehicle Simulation

Four basic tire models suitable for dynamic vehicle simulation are formulated. The models are compared through a six-degree-of-freedom nonlinear simulation of a cargo truck crossing rough ground. Guidelines are developed for the selection of an optimum tire model for a given dynamic vehicle simulation.     

Possible Improvements in Ride Comfort

The random vertical vibration of two linear models of a sprung mass with a passenger on seat is numerically solved. The input signal has a power spectrum of a real road. The acceleration of the passenger is frequency-weighted according to two various criteria. The gain in comfort obtained by lowering the natural frequency of the sprung mass is calculated along with the dynamic and static spring deflections. In addition, a solution of the vibration of the unsprung mass with evaluation of a possible improvement is presented.