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271.
Abstract

This model statute sets out a mechanism for the management of the coastal zone by the coastal states. It provides a possible state response to the Coastal Zone Management Act of 1972. The authors recognize that most states presently have some form of management or legal control over their coastal zone, and the model statute has been written with the intention that all or parts of it could be adapted to the wide variety of state regulatory schemes with the aim of providing unitary management to the valuable resource of the coastal zone.  相似文献   
272.

This paper discusses the tension between the theory and practice of the regulation of road transport externalities from the viewpoint of the trade‐off between efficiency, effectiveness and the social feasibility of regulation. Various possible types of regulatory instruments, subdivided into ‘direct’ demand management, ‘indirect’ demand management and ‘supply side’ oriented policies, are evaluated qualitatively according to these criteria. Attention is then directed towards the trade‐off between efficiency, effectiveness and feasibility within the field of ‘direct’ demand regulation of road transport.  相似文献   
273.
Two-sided markets are characterised by the presence of an intermediary and two groups of end-users. In the cruise market, cruise lines may play the role of intermediaries to connect the two end-users, viz. cruise passengers and cruise ports. Our research explored whether the cruise industry can be regarded as a two-sided market, starting with a theoretical modelling. The findings show that cruise lines might be hybrid intermediaries, selling their own ship-based products and services, while offering also a platform to enable the transaction between cruise passengers and cruise ports. This particular business model of a quasi-two-sided market is also reflected in the pricing scheme of cruise industry, whereby cruise ports charge an entry fee from cruise lines and port dues from cruise passengers. We illustrate an empirical analysis on the basis of the cruise market in Japan, and it provides a preliminary clue that the behaviours of cruise ports and cruise lines are consistent with our theoretical framework. The results are not convincingly significant due to data limitations, hence, the concept of a ‘two-sided market’ in the cruise industry call for further empirical research.  相似文献   
274.
This paper describes a connected-vehicle-based system architecture which can provide more precise and comprehensive information on bus movements and passenger status. Then a dynamic control method is proposed using connected vehicle data. Traditionally, the bus bunching problem has been formulated into one of two types of optimization problem. The first uses total passenger time cost as the objective function and capacity, safe headway, and other factors as constraints. Due to the large number of scenarios considered, this type of framework is inefficient for real-time implementation. The other type uses headway adherence as the objective and applies a feedback control framework to minimize headway variations. Due to the simplicity in the formulation and solution algorithms, the headway-based models are more suitable for real-time transit operations. However, the headway-based feedback control framework proposed in the literature still assumes homogeneous conditions at all bus stations, and does not consider restricting passenger loads within the capacity constraints. In this paper, a dynamic control framework is proposed to improve not only headway adherence but also maintain the stability of passenger load within bus capacity in both homogenous and heterogeneous situations at bus stations. The study provides the stability conditions for optimal control with heterogeneous bus conditions and derives optimal control strategies to minimize passenger transit cost while maintaining vehicle loading within capacity constraints. The proposed model is validated with a numerical analysis and case study based on field data collected in Chengdu, China. The results show that the proposed model performs well on high-demand bus routes.  相似文献   
275.
Wide-ranging and ambitious proposals for the comprehensive transformation of public transport systems in major South African cities, including Cape Town, have now been in play for a decade or more since the country’s post-apartheid transition. To date, progress in implementing such proposals has been, at best, much delayed and, in Cape Town, appears to have stalled, and may now be significantly compromised. This paper draws on aspects of the concept of regulatory cycles in the bus transport sector to explore some of the key factors which have given rise to this situation, focusing primarily on obstacles embedded in the present institutional framework which governs the provision of road-based public transport in the city. It specifically identifies difficulties in establishing an appropriately mandated and resourced agency at the local level to drive forward the transformation project and the sustained opposition of existing, largely ‘self-regulated’ minibus-taxi operators as key factors which have obstructed the introduction of the proposed regime of ‘regulated competition’. A tentative conclusion is offered to the effect that perhaps a partial or ‘hybrid’ transformation of the public transport system may be the best - and, indeed, possibly the most appropriate - outcome of the transformation process that can be anticipated under the present and foreseeable future circumstances prevailing in the city.  相似文献   
276.
The importance of specifying and quantifying the project risks in the investment decision process cannot be overemphasized. Even more so in the context of marine project appraisal, since the shiping markets are characterized by extreme volatility and high cyclicality. The use of probability theory in investment decisions is reviewed and applications are derived for marine projects. The paper focuses on the use of Monte Carlo simulation to determine the mean and variance of the input variables. Within the Monte Carlo framework three alternative methods are used for the construction of probability distributions; the scaled halves of a normal distribution, two unscaled parts of a normal distribution and finally use of altenative distributions, such as beta, gamma and chi-square. An alternative methodology is also drawn from the literature, namely the Pearson-Turkey three point approximation, to contrast with the Monte Carlo method.  相似文献   
277.
The influence of route guidance advice on route choice in urban networks   总被引:5,自引:0,他引:5  
The paper begins by reviewing what is known about route choice processes and notes the mismatch between this knowledge and the route choice assumptions embedded in the most widely used assignment models. Empirical evidence on the influence of route guidance advice on route choice is reviewed and, despite its limited nature, is seen to suggest that users are reluctant to follow advice unless they find it convincing and that, the more familiar they are with the network, the less likely they are to accept advice. Typically only a small minority of journeys are made in total compliance with advice.Results from an interactive route choice simulator (IGOR) are summarised and are seen to reveal that compliance depends on the extent to which the advice is corroborated by other factors, on the drivers' familiarity with the network and on the quality of advice previously received. It is noted that the IGOR results are in a form which would enable response models to be calibrated.Recent approaches to the modelling of route choice in the context of guidance are discussed. Some are seen to make simplifying assumptions which must limit the relevance of their results; most make no allowance for the fact that drivers are unlikely to comply with all advice and several are not able to represent the benefits which guidance might bring in the context of sporadic congestion or incidents.As an alternative, a two phase model comprising a medium term strategic equilibrium and a day-specific simulation with explicit representation of driver response is proposed.Updated and extended from an earlier version published in theProceedings of the Japan Society of Civil Engineers (JSCE No 425/IV-4, 1991-1).  相似文献   
278.
P&I clubs, as shipowners' organizations providing liability insurance for the same shipowners have a particularly vital role to play in exerting peer group pressure and raising standards of safety. Solutions are, however, never as simple as one might wish; this article explores the tensions and constraints within which P&I clubs operate, analyses where they are best equipped to support the Donaldson initiative and points out that there is an inherent conflict between liberal modern society and the desire for discipline on the high seas.  相似文献   
279.
It is argued that an understanding of variability is central to the modelling of travel behaviour and the assessment of policy impacts, and is not the peripheral issue that it has often been considered. Drawing on recent studies in the UK and Australia, in conjunction with a review of the literature, the paper first examines the policy and analytical rationale for using multi-day data, then illustrates different ways of measuring variability, and finally discusses issues relating to the collection of suitable data for such analyses. In a policy context, there is a growing need for multi-day data to examine issues that affect general rather than one-day behaviour (e.g. to assess the distribution of user charges for road pricing, or patterns of public transport usage); while analytically, multi-day data is needed to improve our ability to identify the mechanisms behind travel behaviour and to derive better empirical relationships. Three measures of variability are presented: a graphical form showing daily differences in behaviour at the individual level; an aggregate, similarity index; and a hybrid graphical/numerical measure, which provides new insights into variability in daily patterns of behaviour. The paper raises a number of issues for debate, probably the most crucial of which is: variability in what? The way in which behaviour is measured crucially affects our conception of stability and variability.  相似文献   
280.
THESTUDYOFTHECHANGESANDMECHANISMOFHINDQUARTERVASCULARRESISTANCEINRATSWITHMYOCARDIALINFARCTIONQinJin(秦金);PeterFinn(Departmento...  相似文献   
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