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181.
Coastal areas are under increasing pressure driven by demands for coastal space, primarily though population growth, in migration and the need for space for socioeconomic activities. The pressures and associated changes to the coastal environment need to be managed to ensure long-term sustainability. South Africa has enacted an Integrated Coastal Management Act (ICM Act) to facilitate dedicated management of its coastal environment. The implementation has been met with a number of challenges, primarily relating to financial and human capacity constraints, particularly at the local government level. Given that the ICM Act devolves powers to local government, it is imperative that implementation challenges be addressed. This paper focuses on KwaZulu-Natal, one of four South African coastal regions, which is a renowned tourist destination and home to 11.1 million people (Statistics South Africa 2015). This paper considers the state of coastal management, as well as implementation challenges being experienced at a local governance level, and highlights ways to address these. Data were acquired through questionnaire surveys and semistructured interviews. The Drivers-Pressures-State-Impact-Response (DPSIR) framework was used to identify relevant ICM issues and concerns and develop potential actions for improving the implementation of coastal management activities and the ICM Act. In the assessment of the ICM governance and implementation to date, a key concern identified was a general lack of coastal management knowledge among officials. It was specifically identified that knowledgeable management and capacity-building required championing from the provincial government in order to more efficiently and effectively implement the objectives of the ICM Act through an improved understanding of the coastal environment, its functioning and management. 相似文献
182.
人们对车辆的需求趋向于安全性更强、质量更轻且燃料利用效率更高等方面,一种采用了先进高强度钢材、工程塑料及轻质金属的轻型车车体结构也随之打入市场。如果将上述材料单独使用,就会给最大限度减轻车体质量的潜能带来限制。一种以化学基材为基础的结构粘合剂和结构泡沫塑料的应用,巧妙地将上述3种减轻车体质量的材料结合在一起,克服了安全性差.质量难以减轻和加工成本高等难题。 相似文献
183.
为探讨外生性面神经雪旺氏细胞瘤的病理来源及病因 ,对 152 6耳颞骨连续切片进行组织病理学观察。结果发现 :39耳在面神经骨性管裂处显示神经外膜先天性缺损 ,神经主干由此疝出。其中31耳 ,在疝出面神经凸面有明显的雪旺氏细胞增生。这 31耳中 ,有 12耳在卵圆窗上方 ,1耳在面神经第二膝部形成小的外生性雪旺氏细胞瘤。提示 :管裂处神经外膜的先天性缺损是面神经由此疝出的组织解剖学原因。面神经疝出可能是刺激雪旺氏细胞增生 ,以致形成外生性面神经雪旺氏细胞瘤的直接原因。 相似文献
184.
Konstantinos G. Zografos Yiannis Salouras Michael A. Madas 《Transportation Research Part C: Emerging Technologies》2012,21(1):244-256
The existing slot allocation mechanism, based on the International Air Transport Association (IATA) system and its complementary version of the European Union (EU) regulation, produces rather poor capacity allocation outcomes for congested EU airports since it fails to properly match slots requested with slots allocated to airlines. Inefficiencies during the initial allocation are mainly due to the problem complexity in conjunction to limited decision support available to slot coordinators. On the other hand, substantial inefficiencies give rise to severe slot misuse and unreasonably low utilisation of airport resources running already into scarcity. The objective of this paper is to develop an optimisation-based model implementing the existing EU/IATA rules, operational constraints, and coordination procedures with the ultimate objective to better accommodate airlines’ preferences at coordinated airports through the minimisation of the difference between the requested and the allocated slot times to airlines. The results of the model are assessed and compared vis-à-vis the allocation outcome produced according to current slot coordination practice in three regional Greek airports. The proposed model produces very promising results and demonstrates that there is large room for improvement of the efficiency of the current allocation outcome in a range between 14% and 95%. The discussion of the model results is complemented by a sensitivity analysis highlighting the importance of declared capacity and the magnitude of its influence on slot allocation efficiency. 相似文献
185.
Statistical inference on transit route‐level origin–destination flows using automatic passenger counter data
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We consider inferring transit route‐level origin–destination (OD) flows using large amounts of automatic passenger counter (APC) boarding and alighting data based on a statistical formulation. One critical problem is that we need to enumerate the OD flow matrices that are consistent with the APC data for each bus trip to evaluate the model likelihood function. The OD enumeration problem has not been addressed satisfactorily in the literature. Thus, we propose a novel sampler to avoid the need to enumerate OD flow matrices by generating them recursively from the first alighting stop to the last stop of the bus route of interest. A Markov chain Monte Carlo (MCMC) method that incorporates the proposed sampler is developed to simulate the posterior distributions of the OD flows. Numerical investigations on an operational bus route under a realistic OD structure demonstrate the superiority of the proposed MCMC method over an existing MCMC method and a state‐of‐the‐practice method. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
186.
Jens-Uwe Schr?der-Hinrichs Erik Hollnagel Michael Baldauf 《WMU Journal of Maritime Affairs》2012,11(2):151-167
The recent foundering of the Costa Concordia in January 2012 demonstrated that accidents can occur even with ships that are considered masterpieces of modern technology and despite more than 100?years of regulatory and technological progress in maritime safety. The purpose of this paper is, however, not to speculate about the concrete causes of the Costa Concordia accident, but rather to consider some human and organizational factors that were present in the Costa Concordia accident as well as in the foundering of the Titanic a century ago, and which can be found in many other maritime accidents over the years. The paper argues that these factors do not work in isolation but in combination and often together with other underlying factors. The paper critically reviews the focus of maritime accident investigations and points out that these factors do not receive sufficient attention. It is argued that the widespread confidence in the efficacy of new or improved technical regulations, that characterizes the recommendations from most maritime accident investigations, has led to a lack of awareness of complex interactions of factors and components in socio-technical systems. If maritime safety is to be sustainably improved, a systemic focus must be adopted in future accident investigations. 相似文献
187.
Agnieszka Walenciak Anna-Marie Constantinou Michael Roe 《Maritime Policy and Management》2013,40(4):323-337
This paper provides an analysis of the development of the liner route between the UK and Poland and the activities of the two main operators—EuroAfrica of Poland and United Baltic Corporation of London. The most significant factors driving the development of this trade are analysed using a combination of an industrial survey and government statistics for the route, before going on to examine the threat to the trade presented by the growth of the trucking mode. 相似文献
188.
Michael Everard 《Maritime Policy and Management》2013,40(2):91-92
There are numerous possible advantages to be gained from the accurate prediction of future movements in the Baltic Freight Index (BFI). Because of the difficulties inherent in long-range forecasting, however, the potential for such predictions to provide insight into the future state of the physical dry bulk market is perhaps limited. The greater accuracy of short-term forecasts, on the other hand, facilitates the development of a forecasting model form is justified by the inevitably continuous nature of futures market speculation. Such a model is developed through the application of the Box—Jenkins approach to time series analysis and forecasting. The methodology is presented and the resulting model is evaluated on the basis of objective measures of predictive power and by comparison with alternative forecasting models. Finally, the applicability of the model to the practice of BIFFEX speculation is assessed by judging its performance within a simulated BIFFEX trading environment. 相似文献
189.
Michael G H Bell 《先进运输杂志》1999,33(2):135-146
Despite the importance of assessing the reliability of transport networks in general there is a paucity of suitable techniques. In part this is due to the fact that network performance depends both on the state of the infrastructure and on the behaviour of network users, where user behaviour is governed by expectations about the state of the network. An approach based on game theory is proposed whereby the performance of the network is estimated for the case where network users are extremely pessimistic about the state of the network. Where the routes are prespecified and route utilities depend only on exogenously given scenarios, the estimation problem may be formulated as a linear program. A reformulation of the problem as a non-linear program allows the impact of the degree of user pessimism on expected network utility to be studied. The problems of implementing the method for large networks with multiple origins and destinations is discussed and an algorithm is proposed. 相似文献
190.
最近,对铁道车辆防火条例进行了大量改动。由于欧洲防火标准要统一,相比个别国家标准例如DIN5510,对防火文件和列车零部件质量做出了额外要求。 相似文献