The Organization of Nautical Training and Executive Leadership

The aim of this paper is to indicate some of the distinctive problems of executive leadership which surround the control of authority in merchant navy training schools in the United Satates, Great Britain, and Spain. On the basis of extensive field interviews with the staff and directors of two American, three British, and two Spanish, schools, our purpose is to suggest the conditions which give rise to the need for particular kinds of leadership styles, depending upon the manner by which nautical education is organized [1]. More specfi-cally, our thesis is that their organizationl chartering arrangements (defined as contractual and quasi-contractual linkages with variious third parties to nautical education) mandate specific kinds of internal structural patterns within nautical schools which, in turn, produce the need for different styles of executive leadership.     

A model for assessing the effects of dynamic travel time information via variable message signs

In view of the serious traffic congestion during peak hours in most metropolitan areas around the world and recent improvement of information technology, there is a growing aspiration to alleviate road congestion by applications of electronic information and communication technology. Providing drivers with dynamic travel time information such as estimated journey times on major routes should help drivers to select better routes and guide them to utilise existing expressway network. This can be regarded as one possible strategy for effective traffic management. This paper aims to investigate the effects and benefits of providing dynamic travel time information to drivers via variable message signs at the expressway network. In order to assess the effects of the dynamic driver information system with making use of the variable message signs, a time-dependent traffic assignment model is proposed. A numerical example is used to illustrate the effects of the dynamic travel time information via variable message signs. This revised version was published online in June 2006 with corrections to the Cover Date.     

A PRT airport - Serving a transportation function

Costly and complicated airports have just three basic functions: (1) service, dispatch and recover airplanes; (2) service, process and embark/debark passengers and material; (3) generate operating cost recovery for owner, operator, sponsor. The first function is ground servicing. The second is embarking and loading, with and subsequent recovery of airplanes, unloading and disembarkation. None of the first function require a terminal of any kind. The second function does, and the third function does nothing for air travel. Use major shopping centers for PRT movement, direct to the jetway. No terminal. Place eleven square buildings between the parallel runways, diamond oriented point-to-point, with four parking spaces -the module sides. Airplanes taxi in and away on one center line, 100 feet from the module centered between in-the-ground service connections. PRT connects two story modules, 200 feet on a side. Jetways at each corner also move vertically up and down to load and unload twice as fast, DOWN the jetway, with baggage on conveyors. PRT from neighborhood centers allows passengers to get tickets from local travel agents, and security check from local police. Travel is secure. Parking and the sales tax take is distributed.     

Truck backhauling on two terminal networks

Truck backhauling reduces empty truck-miles by having drivers haul loads on trips back to their home terminal. This paper 1) examines the impact on backhauling opportunities of terminal locations and directional imbalances in the flow of freight from the terminals, and 2) develops a method for determining which truckloads should be backhauled. Backhauling is studied for two terminals sending full truckloads to many customers under steady-state conditions. This research develops two backhauling models. The first is a continuous model that makes simplifying assumptions about customer locations and travel distances. It results in formulae showing that 1) savings from backhauling increase at a decreasing rate as the directional flow of freight between two terminals becomes more balanced and 2) backhauling is an important, but often ignored, factor in terminal (e.g. trucking terminal, warehouse, or plant) location and supplier selection decisions. The second model is a more general discrete model that determines which loads should be backhauled to minimize empty truck-miles.     

The drag on an airplane taking off from a floating runway

The motions of an infinitely long, two-dimensional runway subjected to the dynamic moving load imposed by an airplane taking off are investigated. The runway is assumed to be floating in an inviscid fluid and is initially at equilibrium before the plane takes off. The deformation of the runway resulting from the take-off is wave-like and moves in the same direction as the plane. The maximum drag occurs when the plane catches up with the first wave. Three different runway configurations were considered: a baseline and ones which were ten and one hundred times more flexible than the baseline. For these runways, the added drag to the aircraft was very small, ranging from 1% for the stiffest to 10% for the most flexible runway.     

High-speed rail service: Issues for the Detroit-Chicago corridor

Several issues concerning the implementation and operation of high-speed rail service in the Detroit-Chicago corridor are identified and discussed in this paper. The primary concern is whether such a service is likely to be attractive enough to induce the private sector to provide it. While the outlook for private operation appears pessimistic, consideration of a broader range of potential benefits (e.g., direct and indirect employment) may justify public involvement and investment.     

Optimal transit subsidy policy

The basic justification for transit subsidy is that such a subsidy is necessary, given substantial economies of scale, in order to permit fares to be set at a level which will result in reasonably efficient use of the service. Efficiency is not, however, merely a matter of the level of the fares but even more of the fare structure and pattern. Major changes in fare patterns are needed to permit reasonable efficiency of utilization to be attained, and full advantage derived from subsidy. Differentiation according to time and direction, as well as the distance of travel, is required. Ideally, competing modes such as the private automobile should be priced at marginal cost, differentially by time and place, and the subsidy should be derived from taxes on land values in the areas where such values are enhanced by the presence of transit service at low fares. In the absence of such conditions, fares should differ from marginal cost in ways that take into account the impacts of transit fare variations on auto traffic and congestion, and on the subsidy requirements and the adverse impacts of the taxes imposed to finance the subsidy.In addition to these economic efficiency considerations there may be added considerations of distributional impact and political acceptability, which may modify the optimal solution somewhat but should not greatly change the main outlines of the patterns to be recommended.     

An experimental testbed for mobile offshore base control concepts

 The concept of a mobile offshore base (MOB) reflects the need to stage and support military and humanitarian operations anywhere in the world. A MOB is a self-propelled, modular, floating platform that can be assembled into lengths of up to 2 km, as required, to provide logistic support to US military operations where fixed bases are not available or adequate. It accommodates the take-off and landing of C17 aircraft, and can be used for storage, as well as to send resources quickly to shore. In most concepts, the structure is made of three to five modules, which have to perform long-term station-keeping in the presence of winds, waves, and currents. This is usually referred to as dynamic positioning (DP). In the MOB, the alignment is maintained through the use of thrusters, connectors, or a combination of both. In this paper, we consider the real-time control of scaled models of a MOB. The modules are built at the 1 : 150 scale, and are kept aligned by rotating thrusters under a hierarchical hybrid control scheme. This paper describes a physical testbed developed at the University of California, Berkeley, under a grant from the US Office of Naval Research, for the purpose of evaluating competing MOB control concepts. Received: June 4, 2002 / Accepted: October 30, 2002 Acknowledgments. This material is based on work supported by the MOB Program of the US Office of Naval Research under grant N00014-98-1-0744. The authors would like to thank the Link Foundation for its support. Many thanks go to Stephen Spry for his experimental work. The photographs are courtesy of Bill Stone, Gerald Stone, and Jay Sullivan of the PATH Publications staff. Address correspondence to: A.R. Girard (e-mail: anouck@eecs.berkeley.edu)