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This paper assumes that activities at the home and work location are important determinants of individuals' paths through time and space. Fixed activities at these locations determine to a large extent the duration and timing of time windows – blocks of time available for participation in travel and out-of-home non-work activities. Taking the time spent at home and at the workplace as a starting point, this paper classifies activity patterns on workdays into six groups with distinct home- and work-stay patterns. For this, data are used from the 1998 Netherlands National Travel Survey. The six clusters vary in terms of the duration and timing of time windows and some of the differences can be explained by commute characteristics, types of non-work activities performed, workers' sociodemographic attributes, and their spatiotemporal environment. However, the impact of sociodemographic and spatiotemporal variables on cluster membership is shown to be weak. 相似文献
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Transportation - The associations between objective and subjective dimensions of the built environment and walking behaviour have been examined extensively in existing studies. However, the... 相似文献
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Community-based management (CBM) could be an essential tool to prevent the depletion of marine resources in the Western Indian Ocean region. In Kenya, political pressure to strengthen local governance, has led to adoption of CBM as a way of reducing over-exploitation and managing the competing uses and impacts on the marine environment. Several communities in Kenya have embraced CBM and have set aside or closed previously fished areas to enhance recovery of fisheries and biodiversity. These community fisheries closures (locally called tengefu), despite being degraded, may recover to finfish abundances and biodiversity levels similar to established MPAs or above thresholds for maintaining some ecological services. Communities see their direct involvement and control of these tengefu as more likely to result in benefits flowing directly to them. Community closures are also important for articulating and resolving community values and strengthening their management capacity. Here, we describe the evolution of the tengefu movement in Kenya and combine information from focus group discussions, interviews, underwater surveys and boundary marking to evaluate the current status, opportunities and challenges facing these tengefu. We show that in some cases community closures suffer from slow and incomplete national and local legislative processes, challenges to compliance, and weak management. 相似文献
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A panel method is described for calculating potential flow around near-surface submarines. The method uses Havelock sources which automatically satisfy the linearized free-surface boundary condition. Outputs from the method include pressure field, pressure drag, wave resistance, vertical force, trim moment and wave pattern. Comparisons are made with model tests for wave resistance of Series 58 and DARPA SUBOFF hulls, as well as with wave resistance, lift force and trim moment of three length-to-diameter variants of the DSTO Joubert submarine hull. It is found that the Havelock source panel method is capable of determining with reasonable accuracy wave resistance, vertical force and trim moment for submarine hulls. Further experimental data are required in order to assess the accuracy of the method for pressure field and wave pattern prediction. The method is implemented in the computer code “HullWave” and offers potential advantages over RANS-CFD codes in terms of speed, simplicity and robustness. 相似文献
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Tim Wilkins 《中国远洋航务》2010,(3):14-15
按照规定,单壳油轮已经被逐步淘汰,而我们却还在2009年年未考虑淘汰所带来的影响,这看起来也许有点奇怪。有些人甚至会觉得,自己回到了五年前。那时候,这是一个重要的争论焦点,而围绕2010年这个期限尚有不少疑问。在2004年,这是任何重大海运会议都必定涉及的首要问题。事实上,我记得一位业界观察家好像评论说, 相似文献
7.
Tim Wilkins 《中国远洋航务公告》2010,(3):14-15
按照规定,单壳油轮已经被逐步淘汰,而我们却还在2009年年未考虑淘汰所带来的影响,这看起来也许有点奇怪。有些人甚至会觉得,自己回到了五年前。那时候,这是一个重要的争论焦点,而围绕2010年这个期限尚有不少疑问。在2004年,这是任何重大海运会议都必定涉及的首要问题。事实上,我记得一位业界观察家好像评论说, 相似文献
8.
This paper seeks to improve our understanding of passengers’ behavioral intention by proposing an integrated framework from
the attitudinal perspective. According to the literature in marketing research, we establish a causal relationship model that
considers “service quality-satisfaction-behavioral intentions” paradigm, perceived value theory, and switching barrier theory.
Exploring passengers’ behavioral intention from satisfaction and perceived value help to understand how passengers are attracted
by the company, while switching barriers assist in realizing how passengers are “locked” into a relationship with the current
company. Furthermore, in order to capture the nature of service quality, we adopt a hierarchical factor structure which serves
service quality as the higher-order factor. In this study, coach industry is selected as our research subject. The empirical
results, as hypothesized, show that all causal relationships are statistically significant, and perceived value us the most
important predictor of satisfaction and passengers’ behavioral intention. In conclusion, the managerial implications and suggestions
for future research are discussed. 相似文献
9.
Karolina Isaksson Tim Richardson 《Transportation Research Part A: Policy and Practice》2009,43(3):251-257
The controversial nature of urban congestion charging policies makes them politically risky. Urban planners, policy makers and politicians are forced to consider how they can legitimately introduce a policy that the public may not want. Implementation in London, and failure in Edinburgh, raise questions about whether they should seek full citizen support, or work strategically towards implementation in the face of public opposition.This paper reports on an investigation of the Stockholm congestion charging trial (SCCT). It analyses the strategy developed by the city authorities to create legitimacy for the implementation of the SCCT. The SCCT is examined in two steps, firstly how the ‘trial + referendum’ approach was successful in securing public acceptance, and secondly how key aspects of the design of the trial and the subsequent referendum were adjusted in response to emerging risks, demonstrating the pragmatic approach of the city leaders managing the policy process. The study suggests that the city leaders chose a clearly pragmatic approach, grounded in compromise, yet subtly designed to avoid openly confronting the status quo. The strategy was continuously adapted and adjusted, in the face of emerging risks, and clearly served to create consensus while avoiding difficult questions of urban mobility. 相似文献
10.
Integrated Control Methodologies for Road Vehicles 总被引:5,自引:0,他引:5
Tim Gordon Mark Howell Felipe Brandao 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,40(1):157-190
Summary This paper considers the scope, methodologies and architectures for the design and development of interacting control systems in road vehicles. The increasing use of electronic controls leads inevitably to an increase in overall system complexity. Given the time and economic constraints of the modern automotive industry, it is not feasible to synthesise and validate the full set of vehicle controls in the form of a unified and centralized controller. On the other hand a fully decentralized approach to control system development and operation will induce performance limitations from un-modelled or unexpected interactions; at worst, such interactions can cause instability and loss of function. There is now increasing pressure to achieve control coordination whilst maintaining a modular approach to the overall system design. With this in mind, the paper provides a framework to review current practice in integrated vehicle control, assesses recent developments in control integration methodologies that are most relevant to the vehicle application, and formulates an enhanced multi-layer architecture that includes explicit coordination functionality. Overall emphasis is placed on the role of control system architecture, the resulting flow of control information and the implications for control system design. An example from handling dynamics is presented, demonstrating the viability of new and flexible approaches. In conclusion a number of outstanding research problems are highlighted. 相似文献