首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
In container port performance evaluation, a group of ports in one country is always significantly different from a group of ports in another country. This is noticed as the heterogeneity of port performance. It is therefore necessary to further investigate the impact of the different groups on efficiency evaluation of ports. The cross-evaluation method is a DEA extension tool to identify best performing DMUs and to rank DMUs using cross efficiency scores linked to all DMUs. A factor that possibly reduces the usefulness of the cross efficiency evaluation method is that cross efficiency scores may not be unique due to the presence of alternative optima. Doyle and Green 1 Doyle, J and Green, R. 1994. Efficiency and cross efficiency in DEA: Derivations, meanings and uses. Journal of the Operational Research Society, 45: 567578. [Taylor & Francis Online], [Web of Science ®] [Google Scholar] propose the use of secondary goals to deal with the non-uniqueness issue by the aggressive/benevolent model formulations. This article extends the model of Doyle and Green by considering the groups of DMUs in the determination of final cross efficiency. A new approach based on cross efficiency evaluation method is developed and applied to efficiency analysis of 28 container ports from 12 countries in Asia. A comparative study between traditional and newly proposed methods is conducted.  相似文献   

2.
The Disability Discrimination Act (1995, amended 2005), Equality Act (2010 Equality Act. 2010. Equality Act. http://www.legislation.gov.uk/ukpga/2010/15/contents#openingWholeMod (accessed May 17, 2012) [Google Scholar]), EU Disability Action Plan (2003 –2010), and EU Disability Strategy (2010–2020) were designed to make equal opportunities a “reality.” As 16% of the EU population, is statutorily disabled there are considerable implications for beach management. Research examples of beach users include swimmers, anglers, etc. - but rarely people with learning disabilities (LD). This paper considered beach users with LD and their appreciation of three different coastal classifications in South Wales. Because of their disabilities, the research applied a participatory photo interpretation methodology (photovoice). A comparison of the LD ranking of beach issues was made with rankings provided by the general public at the same beaches. Results demonstrated some similarities between LD and general public coastal needs, but identified the need for specific considerations to be made by beach managers for LD users, including informed self-advocacy, use/application of signage, instructive access and a requirement for baseline information gathering. The research proposes an integrated coastal access model from which coastal management/gatekeepers can consider LD needs within coastal strategies. Finally, findings highlight the use of photovoice in coastal research projects and the need for innovative methodological considerations when researching certain groups.  相似文献   

3.
In Part 1 * *Maritime Studies and Management (1975) Vol 3, No. 2, pp. 103–111. of this article a background to the economics of conference operation was provided, and conference fleet planning and single voyage costs were discussed. This part of the paper will analyse the economic objectives of conferences and will consider the implications of ending the conference princing structure. Some recommendations are also offered.  相似文献   

4.
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 Statistics South Africa. 2015. Mid-Year Population Estimates. Statistical release P0302. Pretoria, South Africa: Statistics South Africa. [Google Scholar]). 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   

5.
We investigated the difference in fatigue behaviour between the aluminium alloys A5083-O and A5083-H321, which are used as structural components in ships and high speed craft. We obtained S–N curves for the base materials and the welded joints made of A5083-O. The relationships between the fatigue crack propagation rates and the stress intensity factor ranges ΔK, ΔK eff and ΔK RPG (Toyosada et al. in Int J Fatigue 26(9):983–992, 2004) were determined. Additionally, the evolution of fatigue crack growth for the base materials and the welded joints made of A5083-O was measured. We also carried out numerical simulations of fatigue crack growth for both base metals and their welded joints made of A5083-O. The difference in fatigue crack growth behaviour for each alloy and the validity of the numerical simulations of fatigue crack growth based on the RPG stress criterion (Toyosada et al. 2004) in the base materials and their welded joints was investigated.  相似文献   

6.
Piracy has unfortunately become a health and safety risk for seafarers in the maritime industry today. However, little do we know about the impact of a pirate hijacking situation and how seafarers cope. Focusing on negotiation communication, the analysis debouches in a discussion of the dynamics of coping strategies, by investigating 173 authentic audio recordings of communication sequences recorded during a pirate hijacking situation that were donated voluntarily by a shipping company. The Captain assessed and reflected on the course of events in the situation, to which the negotiator responded appropriately, with acknowledging brief responses or psychological aid. This is similar to other highly dynamic decision-making settings, where decision-makers tend to continuously reflect and revise their view of the situation (Eraut 2000). The data is also consistent with the “reflection-in-action” concept by Schön (1983) used by van den Heuvel et al. (Cogn Technol Work 16: 25–45, 2014) in their investigation of communication of police officers in hostage situations. However, the coping dynamics changed when the negotiator’s responses became too minimal. This shows how the context and the individual’s cognitive appraisal of the encounter co-shapes the coping dynamics in the situation. It is urged that pre-piracy care and seafarer training involves practical examples and information about roles and coping dynamics in negotiation communication as part of an orchestrated approach to the scourge of piracy.  相似文献   

7.
Monte Carlo analyses are generally considered the standard for uncertainty analysis. While accurate, these analyses can be expensive computationally. Recently, polynomial chaos has been proposed as an alternative approach to the estimation of uncertainty distributions (Hosder et al. A non-intrusive polynomial chaos method for uncertainty propagation in CFD simulations. In: 44th AIAA aerospace sciences meeting and exhibit, Reno, Nevada, 2006; Wu et al. Uncertainty analysis for parametric roll using non-intrusive polynomial chaos. In: Proceedings of the 12th international ship stability workshop, Washington, DC, USA, 2011). This approach works by representing the function as a series of orthogonal polynomials; the weights for which can be calculated via several methods. Previous studies have demonstrated the usefulness of this technique for comparatively simple systems such as parametric roll modeled by the Mathieu equation with normally distributed parameter values (Wu et al. Uncertainty analysis for parametric roll using non-intrusive polynomial chaos. In: Proceedings of the 12th international ship stability workshop, Washington, DC, USA, 2011). In the present work, a polynomial chaos method is applied to a nonlinear computational ship dynamics model with normally distributed input parameters. Test cases were selected where parametric roll was expected to potentially occur. The resulting probability distributions are compared to the results of a Monte Carlo analysis. In general, these results demonstrate good agreement between Monte Carlo simulation and polynomial chaos in the absence of capsize with significant computation gains found with polynomial chaos. Overall, we conclude that polynomial chaos is an effective tool for reducing simulation time costs when studying parametric roll, and potentially other ship dynamics phenomena, particularly in the absence of capsize-like bifurcations.  相似文献   

8.
The geoduck clam fishery, worth approximately CDN $40 million 1 US $ equivalence: 35 million (Bank of Canada exchange rate on February 1, 2006). in annual landed value, is British Columbia's most valuable invertebrate fishery. This fishery has been co-managed by the Department of Fisheries and Oceans (DFO) and the Underwater Harvesters Association (UHA) since 1989. Earlier input control measures such as effort regulation, seasonal closures, and licenses failed to work effectively for more than ten years, resulting in excess fishing capacity, over harvesting, poor economic returns, and unsafe fishing practices. Output control measures such as the individual vessel quota system (IVQ) have, to some extent, proven successful in improving revenues, controlling excess fishing capacity, gaining compliance with regulations, and involving fishers in the joint decision-making processes. However, there are public concerns about a common property resource at risk of being dominated by a few UHA license holders. Additionally, there are concerns about the job losses resulting from IVQ implementation, as well as distribution and equity issues. This article traces and examines the policy context for fisheries management in the British Columbia (BC) geoduck fishery, discusses the major concerns surrounding the exploitation of long lived Methuselah's clams and concludes with areas for further research in sustaining this lucrative fishery.  相似文献   

9.
One outcome of globalization is an increasing number of seafarers, who seldom are members of the same crew two voyages in a row and must cooperate with seafarers from many countries (Progoulaki and Roe WMU J Marit Affairs 10:7–23, 2011). This situation challenges the level of social capital on board, i.e., the resources inherent in network cooperation associated with norms of reciprocity and trust (Putnam 2000: 19). Fragmentized “blue” social capital should, however, be restored, as work performance depends on the quality of cooperation among crew members horizontally, as well as between crew members and the shipping company vertically. Drawing on anthropological fieldwork data from four Danish international ships, the purpose of this paper is to offer a new theoretical framework for analyzing cooperation among crews. Our inductive empirical findings suggest that a balance between three types of social capital—bonding, bridging and linking—is needed to achieve a high-performing work system (Gittell et al. Organ Sci 21(2):490–506, 2010). Hence, the main actors within the shipping sector should take “blue” social capital into account to increase work efficiency and economic performance.  相似文献   

10.
11.
12.
13.
14.
The establishment and implementation of a training programme requires a training needs assessment (TNA). Without this approach, more often than not, training programmes have failed to succeed and to make such an assessment the instructional designer, i.e. the person in charge for this work, needs to follow a methodology. Unlike the other industries, the port industry has neglected the use of these methodologies, which is shown by the lack of research work published in academic journals. With a view to fill the existing gap, the paper proposes a five-step TNA methodology to be used in the port industry and applies its first three steps to investigate the port training situation in the new European Union member states. To achieve this objective, the paper is structured in the following way: Section 1 puts the research work into context; section 2 addresses the role of ports; section 3. presents a port TNA methodology; section 4. explains research methodology; section 5 addresses port training issues in the new European-member states; and section 6 presents conclusions and further comments.  相似文献   

15.
Large and long ships experience springing behavior. Depending on the trade routes and design of such ocean-going ships, wave-induced vibrations may be due to springing and whipping effects. In this paper, we address the wave-induced vibrations in an ultra-large ore carrier under fully loaded and ballast conditions. The experimental measurements from tests performed using a flexible model of the ship were compared with the numerical predictions from 3-D hydro-elastic theory (THAFTS) (Wu, Hydroelasticity of floating bodies. PH.D thesis, Brunel University, 1984). The measurements showed multiple frequencies between the encountered wave frequency and the 2-node bending frequency that occurred only in ballast conditions, whereas the springing vibrations were more apparent with forward speed under ballast conditions in both regular and irregular waves. The numerical method predicted the vertical bending moment quite well in the fully loaded condition but underestimated it in the ballast condition. This result was primarily due to an inability to capture the prediction of the multiple frequencies between the encountered wave frequency and the 2-node bending frequency. Using THAFTS, a new ship form with a deep draft was introduced, and this vessel was shown to reduce springing vibrations.  相似文献   

16.
17.
We address in this article, how to calculate the restoring characteristic and the excitation of a nonlinear forced oscillating system. Under the assumption that the forced nonlinear oscillator has a periodic solution with period \(T=2\pi / \omega\), we constructed a system of linear equations by introducing time-dependent multipliers. The periodicity assumption helps simplify the system of linear equations. The stability and uniqueness are also presented for the inverse problem. Numerical testing is conducted to show the effectiveness of our presented methodology.  相似文献   

18.
This study examines the hydrodynamic performance of multiple-row vertical slotted breakwaters. We developed a mathematical model based on an eigenfunction expansion method and a least squares technique for Stokes second-order waves. The numerical results obtained for limiting cases of double-row and triple-row walls are in good agreement with results of previous studies and experimental results. Comparisons with experimental measurements of the reflection, transmission, and dissipation coefficients (C R , C T , and C E ) for double-row walls show that the proposed mathematical model adequately reproduces most of the important features. We found that for double-row walls, the C R increases with increasing wave number, kd, and with a decreasing permeable wall part, dm. The C T follows the opposite trend. The C E slowly increases with an increasing kd for lower kd values, reaches a maximum, and then decreases again. In addition, an increasing porosity of dm would significantly decrease the C R , while increasing the C T . At lower values of kd, a decreasing porosity increases the C E , but for high values of kd, a decreasing porosity reduces the C E . The numerical results indicate that, for triple-row walls, the effect of the arrangement of the chamber widths on hydrodynamic characteristics is not significant, except when kd<0.5. Double-row slotted breakwaters may exhibit a good wave-absorbing performance at kd>0.5, where by the horizontal wave force may be smaller than that of a single wall. On the other hand, the difference between double-row and triple-row vertical slotted breakwaters is marginal.  相似文献   

19.
This study asses the effectiveness of classroom-based bridge resource management (BRM) training for junior naval officers, in which general principles of human behaviour and performance in teams and under stress were conveyed. Although BRM training is recommended by the International Maritime Organization and is increasingly common in seafaring, very little is known about whether the adaptation of crew resource management (CRM) training from aviation to the maritime domain has been successful and what type of training is effective. A study with a quasi-experimental, two-factorial mixed design was conducted with BRM training as the between factor and time as the within factor. For 117 study participants, evaluation criteria were assessed on all levels as defined by Kirkpatrick (Train Dev J, 178–192 1979): subjective training evaluation, knowledge, attitudes and behaviour as well as performance while commanding a vessel during a real-world exercise. BRM participants showed better subjective training evaluations and more BRM-related knowledge than controls. Training did not produce differences between groups regarding BRM-related attitudes, the demonstration of non-technical skills or the overall success in the real-world exercise. Overall, BRM training effectiveness was rather low, which can most probably be attributed to the focus of training on generalizable knowledge, skills and attitudes at the expense of their specific application to the context of the real-world exercise. In the design of BRM and CRM training courses alike, the effective application of general principles to a given context must be defined, and the application must be emphasised during training delivery.  相似文献   

20.
In 2016, the world shipping fleet grew by 3.5%. Even if the annual growth rate remains at its lowest since 2013, the global situation is still in overcapacity (UNCTAD 2016). Ninety percent of global trade, by volume, is done by sea. Monitoring this fleet helps with vessel navigation, informing to help avoid critical situations such as collisions, accidents leading to oil pollution, grounding, or ships in distress, but also because traffic management in congested areas is essential. For system wide management, in regions such as MPAs (marine protected areas), conservation is the key factor, and movements can be monitored and analyzed in order to determine illegal or suspicious activities, or in order to limit and/or divert traffic, to mitigate the risks to species subject to protection. It is among these efforts that the automatic identification system (AIS) can play a key role. Since 2004, this VHF transceiver-based reporting system, imposed by the International Maritime Organization (IMO), has shifted from a traditional vessel identification device to a tool used in a wide variety of applications. The most common uses are safety and security; these issues are quite visible in the media and may touch more people on a global scale (e.g., piracy, oil spills). Over the years, AIS has become, especially with the emergence of the satellite-based capture of the signal in 2011, a widely used tool for developing applications such as fisheries monitoring, marine conservation, air pollution forecasting and modeling, ballast water monitoring, invasive species transport, and many more. In this paper, we propose to review the peer-reviewed publications related to the uses and applications of the AIS.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号