排序方式: 共有56条查询结果,搜索用时 15 毫秒
1.
Reducing traffic volumes and CO2-emissions from freight transport has proven difficult in many countries. Although the increasing suburbanization of warehouses is seen as a relevant land use trend, comprehensive analyses of their impact remain scarce. This study uses real data in modeling transport, costs, environmental and modal effects from warehouse relocations around Oslo and Trondheim (Norway). Results indicate that for Oslo, traffic performance (ton-km), CO2-emissions, and transport costs increase following warehouse suburbanization. For Trondheim, transport performance and CO2-emissions increase less, while transport costs decrease marginally. We conclude that specific case characteristics (geography and trade patterns) are important in determining the strength and direction of effects, and expect that common concomitant developments (warehouse centralization and consolidation) would lead to more pronounced results. Our findings confirm some, but challenge other, findings from the relatively scarcely literature available. Finally, the study's more general insights and observations can help advance similar analyses beyond Norway. 相似文献
2.
The study is based on a literature review of recent empirical research on crew resource management (CRM) training in the maritime industry, organised around what non-technical skills to learn and how. The review indicates that existing work is dominated by individualistic theories of learning with less focus on learning as a social process. Five main categories of skills that need to be trained are identified: assertiveness, decision-making, communication, situation awareness and team coordination. We argue that it is necessary to operationalise these broad concepts further, emphasising the work context and crew-specific needs. The review also shows that a combination of classroom lectures and simulator-based exercises is commonly used in maritime education and training in these skills. The learning effect seems to be suffering from training programmes that are exported ‘as is’ from aviation and not adjusted to the maritime domain or to operation-specific needs. This paper examines maritime crew resource management training from a social learning perspective, involving the view that learning is a context bound, social process that might take place in communities of practice (CoP). A CoP is a group (e.g. a crew) wherein members share an activity and learn from each other. It is argued that CRM training programmes will benefit from including a social learning perspective. Factors that enable the assessment of teams are discussed, and it is argued that the training should be tailored to existing crews, emphasising a learning environment as close to reality as possible. 相似文献
3.
Navigating in confined waters with a pilot aboard requires that the pilot’s intention and plan is understood by all present on the bridge. The present study investigates the effect of having a detailed route plan and monitoring it in the context of pilotage. The aim was to see how the presence of a shared pilot passage plan in the Electronic Chart Display and Information System (ECDIS) affects the identification and recovery from navigational errors made by a pilot. Twenty participants, 10 with a shared route plan and 10 without, participated as navigators in a simulator scenario involving pilotage in the Oslofjord. Participants were bachelor students in nautical science. The navigation scenarios involved the intentional error by the pilot just before a predefined way point. Three measurements of relevance to navigational safety were recorded: (1) the time it took the participant to express concern, (2) the time it took the participant to correct the error (‘time to recovery’), and (3) the number of groundings. The study revealed that time to express concern and time to recovery were significantly much shorter for the group with a shared pilot passage plan presented in ECDIS than for the group without such a plan. Providing a bridge team with a shared pilot passage plan in ECDIS during pilotage might improve the ability to identify and correct navigational errors. 相似文献
4.
Maria A. Lambrou Ørnulf Jan Rødseth Howard Foster Kay Fjørtoft 《WMU Journal of Maritime Affairs》2013,12(1):41-61
Port information management is considered a critical instrument towards enabling international transport and trade; thus, various forms of Port Information Systems (PORTIS) have been developed today, namely Port Community Systems, Terminal Operating Systems and Single Window systems. In Europe, the nautical information system SafeSeaNet is viewed as an important e-infrastructure. PORTIS systems are expected to evolve into next-generation technological platforms in order to offer a fully integrated digital environment to a multitude of maritime business actors and public authorities towards more efficient, safe and environment-aware transport and trade infrastructures and services. We propose service-oriented computing and model-driven development techniques as a robust PORTIS modelling and development approach. We present a reference model of PORTIS and a particular enabling methodological and technological framework. The proposed approach has been tested in a maritime single-window case. 相似文献
5.
中国动态市场在不断变化,但在变化中依然能抓住不变的本质。其实中国车市走的是成熟市场的发展道路,只是速度加快了。 相似文献
6.
Tufan Arslan Bjørnar Pettersen Helge I. Andersson 《Journal of Marine Science and Technology》2016,21(3):552-566
The present work is motivated by phenomena occurring in the flow field around ship-like bodies with an incoming lateral flow (cross-flow, 90 ° drift angle). Three-dimensional unsteady flows around different ship sections are investigated by using computational fluid dynamic (CFD) tools with large-eddy simulation (LES) subgrid-scale turbulence model. The simulation results are compared to measurements at several Reynolds numbers in the 90–200,000 range. Focus in our investigation is on the characterization of the motion of vortex structures generated by the separated flow. Another target in the study is to obtain better knowledge of the hydrodynamic forces acting on the sections. Computed pressure and drag coefficients are compared with experimental measurements. The comparison between simulations and measurements shows that an LES model can predict the flow field around ship sections in detail and the hydrodynamic forces acting on the sections. 相似文献
7.
Zhendong Liu Per-Anders Jönsson Sebastian Stichel Anders Rønnquist 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(8):1077-1097
The contact between pantograph and catenary at high speeds suffers from high dynamic contact force variation due to stiffness variations and wave propagation. To increase operational speed on an existing catenary system, especially for soft catenary systems, technical upgrading is usually necessary. Therefore, it is desirable to explore a more practical and cost-saving method to increase the operational speed. Based on a 3D pantograph–catenary finite element model, a parametric study on two-pantograph operation with short spacing distances at high speeds shows that, although the performance of the leading pantograph gets deteriorated, the trailing pantograph feels an improvement if pantographs are spaced at a proper distance. Then, two main positive effects, which can cause the improvement, are addressed. Based on a discussion on wear mechanisms, this paper suggests to use the leading pantograph as an auxiliary pantograph, which does not conduct any electric current, to minimise additional wear caused by the leading pantograph. To help implementation and achieve further improvement under this working condition, this paper investigates cases with optimised uplift force on the leading pantograph and with system parameter deviations. The results show that the two positive effects still remain even with some system parameter deviations. About 30% of speed increase should be possibly achieved still sustaining a good dynamic performance with help of the optimised uplift force. 相似文献
8.
This study seeks to identify factors that promote innovation in shipping companies. The study is based on an empirical investigation of 63 companies headquartered in Norway. The results imply that organizational and interorganizational variables are important to innovation. Three aspects of innovation are focused on: (1) service/product innovations, (2) market innovations, and (3) production method innovations. The explanatory variables that are applied in this study capture between 13-51% of the variability of the measures of innovation. The results indicate that an explicit strategy that promotes innovation is very important for the actual level of innovation within shipping companies. In management literature, it is often assumed that organic organizational features like decentralized decision-making promote innovation. The opposite features are assumed to restrain innovation. However, the results do not support these basic assumptions. For example, it seems to be important that managers make precise decisions in order to promote innovation. 相似文献
9.
Impact of Everyday Weather on Individual Daily Travel Behaviours in Perspective: A Literature Review
Despite the hundreds of billions of dollars being spent on infrastructure development -- from roads, rail and airports to energy extraction and power networks to the Internet -- surprisingly little reliable knowledge exists about the performance of these investments in terms of actual costs, benefits and risks. This paper presents results from the first statistically significant study of cost performance in transport infrastructure projects. The sample used is the largest of its kind, covering 258 projects in 20 nations worth approximately US$90 billion (constant 1995 prices). The paper shows with overwhelming statistical significance that in terms of costs transport infrastructure projects do not perform as promised. The conclusion is tested for different project types, different geographical regions and different historical periods. Substantial cost escalation is the rule rather than the exception. For rail, average cost escalation is 45% (SD=38), for fixed links (tunnels and bridges) it is 34% (62) and for roads 20% (30). Cost escalation appears a global phenomenon, existing across 20 nations on five continents. Cost estimates have not improved and cost escalation not decreased over the past 70 years. Cost estimates used in decision-making for transport infrastructure development are highly, systematically and significantly misleading. Large cost escalations combined with large standard deviations translate into large financial risks. However, such risks are typically ignored or underplayed in decision-making, to the detriment of social and economic welfare. 相似文献
10.
ABSTRACTHow vessel crews perceive safety on board (shipboard safety) is a useful indication for the general safety level. In this study a theoretical model was explored, involving factors that could possibly influence shipboard safety. Based on a survey questionnaire (n = 244), safety climate, shipowner efficiency demands and regulatory activities were investigated as influencing factors. Structural equation modelling gave support to the theoretical model and the findings illustrate that simultaneous involvement of various levels of the maritime system (crews, shipowners, regulators) can be effective for safety improvements. The study indicates that shipboard safety is affected by actions and prioritization by external actors through safety climate. It suggests that the maritime industry will profit from monitoring safety climate as part of the ongoing risk considerations, as a supplement to reactive parameters such as accident statistics. 相似文献