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641.
642.
It is argued that some of Grey's criticisms (this issue) — including those at the centre of his argument - are based on faulty logic, invalid premises, or lack of clarity about what current practice actually is. An appropriate definition of generalised cost, together with a sensitive disaggregation of major groups of the population, can help to increase the reliability of forecasts and provide a consistent underlying framework for analysis of otherwise disparate projects.Some of Grey's criticisms are more valid, however, and there is a case for some changes in current practice. This can best be done by adapting, rather than abolishing, the tool of generalised cost, since the alternatives available seem even more flawed, in terms of being either arbitrary or inconsistent.The author gratefully acknowledges the help of M. H. Fairhurst and M. G. Langdon, who suggested some of the lines of argument in this paper. Opinions are those of the author, not the Greater London Council.  相似文献   
643.
Coordinated development of aviation facilities and services is critical for geographically remote communities. Improvements in aviation capability can be assisted by an analytical base for determining the implications of alternative configurations of air services in terms of links to be served, airport/aerodrome investment, type of flight equipment and flight frequency. We outline a method for identifying airport supply configurations to meet air service demand to and from the Pilbara region of north-west Australia. The approach emphasises minimum levels of demand required from a community in order to justify provision of air services of a given scenario. The method is influenced by the paucity of data on demand in remote communities, and the consequent risk of relying solely on demand-side forecasts of patronage levels. It is therefore particularly useful in assessing transport systems associated with remote resource development projects which are notable for the rapidity of change which they can bring. The approach has relevance to a wide range of transport applications.  相似文献   
644.
645.
The CALINE4 model is widely used to predict the effect of vehicle emissions on ambient concentrations close to roadways. It requires an evaluation of the rate at which different air pollutants are emitted by vehicles, taking into account things such as vehicle flow, velocity, type and age. For Europe the databases of the COmputer Program to calculate Emissions from Road Transport (COPERT) are combined with local vehicle details to obtain site-specific emission factors for dispersion modelling. The ability of CALINE4 to predict the spatial variation of hydrocarbon concentrations downwind of a motorway is assessed, as is the accuracy of COPERT III composite emission factors for several hydrocarbon compounds. The concentrations of seven traffic-associated compounds is found at three locations downwind and upwind of a motorway. Modelled and measured background-corrected downwind concentrations are compared on three bases: daily peak hour concentrations, mean concentrations, and a set of model evaluation parameters.  相似文献   
646.
This Note describes an investigation of spatial variations in the ambient concentrations of hydrocarbons in the vicinity of a suburban motorway during five consecutive weekday morning peak periods of unusually warm and calm conditions. Background-corrected downwind concentrations representing the influence of the motorway source were found to be strongly dependant on wind speed and direction. The ambient ethene-to-acetylene concentration ratio was greatest close to the roadside and the effect of wind speed on the ratio had different average profiles for main wind directions due to different rates of dispersal. Higher values were obtained using background-corrected concentrations.  相似文献   
647.
To identify priority information needs for sea-level rise planning, we conducted workshops in Florida, North Carolina, and Massachusetts in the summer of 2012. Attendees represented professionals from five stakeholder groups: federal and state governments, local governments, universities, businesses, and nongovernmental organizations. Over 100 people attended and 96 participated in breakout groups. Text analysis was used to organize and extract most frequently occurring content from 16 total breakout groups. The most frequent key words/phrases were identified among priority topics within five themes: analytic tools, communications, land use, ecosystem management, and economics. Diverse technical and communication tools were identified to help effectively plan for change. In many communities, planning has not formally begun. Attendees sought advanced prediction tools yet simple messaging for decision-makers facing politically challenging planning questions. High frequency key words/phrases involved fine spatial scales and temporal scales of less than 50 years. Many needs involved communications and the phrase “simple messaging” appeared with the highest frequency. There was some evidence of geographic variation among regions. North Carolina breakout groups had a higher frequency of key words/phrases involving land use. The results reflect challenges and tractable opportunities for planning beyond current, geophysically brief, time scales (e.g., election cycles and mortgage periods).  相似文献   
648.
MMAS in Fiji     
This article is part of a special issue that provides insight into global conservation science by analyzing a 5-year, $12.5 million global marine conservation science and policy program. In this article, we summarize the development of the program in Fiji. In Fiji, the development of marine managed areas was based on the historical system of Qoli-qoli, moderated by the history of British colonialism, wherein local chiefs and villages controlled access to, and rules for the use of, nearshore marine environments.  相似文献   
649.
Drawing on experiences from the four regions and the overall conduct of the Marine Management Area Science (MMAS) program, this concluding article highlights emergent cross-cutting themes that affected MMAS programs across the regions, summarizes the important conservation outcomes of the MMAS program, and then discusses lessons gained from the actual process of conducting the MMAS program. Based on these insights, particularly the last section, this article concludes with recommendations for other conservation programs, specifically those that are global in scope and are science-based with a specific intent to apply that science to conservation action.  相似文献   
650.
A new approach is presented to vehicle-class recognition from video clips. Two new concepts introduced are: probes consisting of local 3-d curve-groups which when projected into video frames are features for recognizing vehicle classes in video clips; and Bayesian recognition based on class probability densities for groups of 3-d distances between pairs of 3-d probes. A full Bayesian recognizer is realized via Monte Carlo simulation method. Also, a sub-optimal but robust camera calibration method is employed and tested extensively.  相似文献   
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