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1.
A simplified model of a low speed large two-stroke marine diesel engine cylinder is developed. The effect of piston position on the in-cylinder swirling flow during the scavenging process is studied using the stereoscopic particle image velocimetry technique. The measurements are conducted at different cross-sectional planes along the cylinder length and at piston positions covering the air intake port by 0, 25, 50 and 75 %. When the intake port is fully open, the tangential velocity profile is similar to a Burgers vortex, whereas the axial velocity has a wake-like profile. Due to internal wall friction, the swirl decays downstream, and the size of the vortex core increases. For increasing port closures, the tangential velocity profile changes from a Burgers vortex to a forced vortex, and the axial velocity changes correspondingly from a wake-like profile to a jet-like profile. For piston position with 75 % intake port closure, the jet-like axial velocity profile at a cross-sectional plane close to the intake port changes back to a wake-like profile at the adjacent downstream cross-sectional plane. This is characteristic of a vortex breakdown. The non-dimensional velocity profiles show no significant variation with the variation in Reynolds number.  相似文献   

2.
Korea has achieved remarkable economic growth over the last three decades. This has largely been due to the adoption of export-oriented economic policies. This economic development has resulted in a rapid increase in export and import cargos. Since the foreign trade of Korea is carried predominantly by sea transport (approximately 99.8% in terms of volume), ports play a crucial role in this process. Although recent port developments are aimed at keeping pace with ever-growing seaborne cargoes, problems persist, especially insufficient port capacity and inefficient management and operations. As a consequence, the ports of Korea suffer from serious port congestion. This problem is particularly acute in Pusan, the fifth largest container port in the world. In the past, all ports in Korea were controlled and administered by the Korea Maritime and Port Administration which was a public port authority. In August 1996, the Korean government established a new government organization, the Ministry of Maritime Affairs and Fisheries (MMAF), with a remit to control and manage its seaports and other related activities and to improve management efficiency in the maritime area. As a way of solving problems related to port congestion and other sources of inefficiency, the new MMAF has launched several new port development schemes. In this context, this paper will discuss (1) the extent of congestion in Korean ports, especially Pusan, the major seaport of the country; and (2) governmental and commercial reaction to solving the problems, including measures such as new port development schemes aimed at attracting private and foreign finance. From this analysis, a strategy for port development in developing countries may be inferred.  相似文献   

3.
Upon the expiry of the concession contract signed between Lebanon and a private company for the Port of Beirut operation (in December 1990), the Government appointed a temporary commission to operate the port under the rules of the expiring concession. The legality of this measure has since always been questioned, while the temporary commission underwent three major personnel changes which clearly prevented any long-term thinking or planning. In 1998, the temporary commission entered into a 20-year joint venture for the establishment of a container terminal. Meanwhile, Lebanon's two main ports were facing major regional competition, while competing against each other to some degree. Thus, the need became urgent to end the temporary status and propose reforms to the entire sector. To that end, the Ministry of Public Works and Transport was commissed by the Government to propose a permanent institutional framework for the port of Beirut while assessing the need for a national maritime sector regulator. This paper presents the recommendations for the institutional reform of the Lebanese maritime transport sector.  相似文献   

4.
Upon the expiry of the concession contract signed between Lebanon and a private company for the Port of Beirut operation (in December 1990), the Government appointed a temporary commission to operate the port under the rules of the expiring concession. The legality of this measure has since always been questioned, while the temporary commission underwent three major personnel changes which clearly prevented any long-term thinking or planning. In 1998, the temporary commission entered into a 20-year joint venture for the establishment of a container terminal. Meanwhile, Lebanon's two main ports were facing major regional competition, while competing against each other to some degree. Thus, the need became urgent to end the temporary status and propose reforms to the entire sector. To that end, the Ministry of Public Works and Transport was commissed by the Government to propose a permanent institutional framework for the port of Beirut while assessing the need for a national maritime sector regulator. This paper presents the recommendations for the institutional reform of the Lebanese maritime transport sector.  相似文献   

5.
Regional ports, as infrastructure in regions, influence transport and regional development policies and planning. The interaction and involvement of regional ports with their stakeholders in the region are pivotal. The conundrum on what constitutes a regional port and thus its region has further complicated this limited researched area. In the extant literature, port and region relationship mainly centres on major metropolitan ports, and pays little heed to regional ports. In this context, this study investigates on how the Australian regional ports can be better involved in regional development. The study adopts a qualitative methodology to explore the Australian regional port stakeholders’ perceptions on port’s role in regional development through 38 semi-structured telephone interviews. Thematic analysis of data assisted by a mixture of NVivo software and manual techniques proposes a conceptual model that may assist policy-making. The key findings suggest that symbiotic growths of ports and concerned regions accelerate regional development. To contribute to regional development, the Australian regional ports can be proactive in building collaboration with regional organisations. The findings have major implications for port managers and port policy-makers for developing a region-oriented long-term port planning and for creating environment for Australian regional ports for regional resource configuration.  相似文献   

6.
Shenzhen Port (SZP), once a negligible local port, has risen dramatically to a world-leading container port and an “equal” player with Hong Kong Port (HKP). Will this market share reallocation continue, or will equilibrium be eventually realized for HKP to prosper continuously? We examine the relationship between these two ports to answer this question. We propose a new transformation method to describe the growth of container cargo transport demand, define the quantitative measures of the competition relationship and port competitiveness, and present a rigorous analytical framework with econometric tests and models to understand the true relationship between HKP and SZP. Direct empirical tests suggest that SZP complements HKP; however, the two ports exhibit strong competition when the effect of demand growth is excluded. Considering transshipment separately, we find that the impact of SZP on HKP is negative in transshipment but complementary in direct shipment. We may conclude that HKP does not affect SZP, whereas SZP has competitive power over HKP. These results are consistent with the findings of some previous theoretical studies.  相似文献   

7.
Appropriate port regulation and competitive forces tend to be related to higher levels of operational and economic performance of ports. From a policy-making perspective, pursuing efficiency and securing competition in ports to reach a level playing field is a two-step process requiring (1) ex-ante regulations to set the rules that maximize the competition for the market, especially when the policy objective is to attract private operations to ports on competitive concession processes and (2) ex-post competition policy to monitor and preserve competition in the market. This paper studies port regulation in Latin America and the Caribbean (LAC) from a competition perspective, analyzing both ex-ante and ex-post policies implemented in the region. The analysis reveals that the competitive environment in LAC is low, giving room for possible anticompetitive practices in the LAC port sector. Since the end of the 1990s, approximately 80% of container terminals in the region were granted to only five companies. Chile and Mexico have been found to be the best practices in the region, with better conditions assuring robust competition in the market. The main policy implication from this analysis is the need for a stronger involvement of antitrust agencies throughout the port concession processes.  相似文献   

8.
The State-owned Spanish Port System (SPS) includes 46 ports for general use that are managed by the 28 port authorities distributed along the 8000 km of Spanish coast. SPS has not grown at a rate comparable to that of international maritime transportation. In our paper, we start from the hypothesis of a port system that appears to be oversized, subsidized, with regard to container traffic. Quantifying the maximum operational capacity of the different container terminals along the Spanish coast and their mooring capacities will provide the available dimensions for this type of traffic. In a second step, we will analyse whether SPS are sufficient (according to the perspective of international standards) to meet Spain’s needs, which is related to Spain’s strategic geographic location and its need to move containerized cargo for the domestic market. The paper concludes SPS has an oversized that limits competitiveness, which is indicated by the average transshipment ratio of approximately 50% and an average unweighted idle ratio of port facilities designed for container traffic of over 60% in the eight main ports.  相似文献   

9.
The efficient integration of logistics modes is critical for international cargo shipping. The local transportation connecting to the export port then plays a vital role in such integration. This paper investigates the problems of carrier selection in the China Pearl River delta area, with respect to international shipping. The analytical hierarchy process (AHP) model is constructed based on a comprehensive industrial interviews and statistical analysis. Rather than simply ranking the given alternatives, we use AHP is used to analyse the weakness and strength of impacting factors in carrier selection. The model is implemented under different types of shipper. Seven criteria are statistically summarized from the questionnaire for evaluating eight different modes. The results are useful to those liner companies serving the PRD region in relationship to port selection and fleet deployment.  相似文献   

10.
The efficient integration of logistics modes is critical for international cargo shipping. The local transportation connecting to the export port then plays a vital role in such integration. This paper investigates the problems of carrier selection in the China Pearl River delta area, with respect to international shipping. The analytical hierarchy process (AHP) model is constructed based on a comprehensive industrial interviews and statistical analysis. Rather than simply ranking the given alternatives, we use AHP is used to analyse the weakness and strength of impacting factors in carrier selection. The model is implemented under different types of shipper. Seven criteria are statistically summarized from the questionnaire for evaluating eight different modes. The results are useful to those liner companies serving the PRD region in relationship to port selection and fleet deployment.  相似文献   

11.
Livelihood diversity factors such as flexibility within fisheries, geographical mobility, reallocation of fishing effort into the broader economy, and the non-material benefits that fisheries provide are important areas of research in marine policy. We use two small-scale fisheries related socio-economic surveys of communities in the Tigak Islands of Papua New Guinea. The first conducted 5 years before a ban on the harvesting of sea cucumbers was imposed and the second from the present day, 5 years after the initiation of the ban—with the objectives of exploring changes in household fishing strategies (types and numbers of species targeted) and to identify any important socioeconomic factors that help explain those changes. Fishing's contribution to total household income has increased significantly (p = 0.019) up from 61% in 2004 to 73% in 2014 with the percentage of female residents living in a household now positively and significantly (p = 0.018) associated with fishing income. The average number of species categories targeted per household increased insignificantly while households with more women are significantly (p = 0.018) less likely to target more species than households with more men. Moreover, customary management practices contribute to this difference. Together, these results show that households are not worse off financially 5 years after the ban on sea cucumber harvesting and that gendered seascape use has implications for the role of livelihood diversity as a marine policy tool.  相似文献   

12.
This study explores the relationship between Australian's attitudes toward climate change impacts on the Great Barrier Reef (GBR) and environmentally responsible behavior (ERB). We hypothesize that general attitudes toward climate change, subjective norms, and perceived behavioral control predict intended and reported behavior, and that attitude negatively influences constraints on adopting ERB. The moderating effect of residential condition (urban vs. rural contexts) was tested across these hypothesized relationships. We randomly selected 200 individuals from eight regions: Five within 50 km of the GBR Coastline and three from the Statistical Metropolitan Areas in Australia. We yielded 1,623 surveys by telephone interviews. Findings confirm our hypotheses and suggest the most important predictor of intentions is perceived behavioral control. The two groups of respondents (urban vs. rural) illustrate different relationships. This study offers insight on how managers of the GBR can effectively shape residents' behavioral tendencies that minimize human impacts on the natural environment.  相似文献   

13.
Labour/management practices in North American ports are undergoing fundamental changes in their shift from confrontation to Cooperation. Cooperation is increasing to counter competitive threats from other ports arising from intermodalism and transportation deregulation. Technological advances in port operations are reducing the number of longshore forces required and changing the skills required of those which remain. A recent survey of North American container terminals provided a 'snapshot' of current approaches of improving labour/management relations. Focusing on growth and development needs of individual port workers enhances morale and motivation resulting in environment. Many ports are introducing new management techniques including improved communications and training to enhance the motivation and productivity of their longshore forces.  相似文献   

14.
This paper discusses the strategies which might be adopted by port authorities, given that modern port technologies have considerably limited the scope for competition. It therefore analyses the several forms of competition relevant to ports, any or all of which may apply in any given instance.

It describes the 'minimalist strategy, which consists of recognizing that public sector bodies have many faults, may make many mistakes and that well-intentioned attempts to rectify faults in the private sector may make matters worse. Second, it describes the ‘pragmatic’ strategy, which involves establishing committees to examine problems and to recommend actions, if they can reach a consensus. Third, it describes the ‘public sector’ strategy, which involves the port authority taking over all port functions. Finally, it describes the ‘competitive’ strategy, which involves a careful reproduction of the circumstances of competition, even though there may be room for only one efficiently-sized operator at a time. Franchising, or short-term leasing on any of a variety of competitive bases, so as to produce serial competition is described. Each of these strategies is presented as having its own advantages and disadvantages, and each may be suitable to particular circumstances.  相似文献   

15.
Book Reviews     
The ever-changing environment in which ports operate has put strong pressure on the traditional role of public port authorities. Market developments have created the need for ports to be part of wider logistics networks and to provide value-added services. Powerful private players who are organised on a global scale, such as carriers, terminal operators and logistics service providers, struggle to gain control over port-oriented logistics networks whereas port authorities very often seem to remain local spectators with limited influence on these market-driven processes. Port authorities are on the other hand, the focal point of criticism from societal interests such as local government, NGOs and citizens for negative externalities related to port development and port operations even if these do not always fall within their direct responsibility. In 1990, Richard Goss questioned, albeit rather rhetorically, the need to have public sector port authorities. Since then scholars have demonstrated a true renaissance or renewed interest in the role of port authorities, recommending repositioning and development of new strategies. Parallel to the concept of the ‘renaissance man’, which is defined as a person who is well educated and excels in a wide variety of subjects or fields, a kind of ‘renaissance port authority’ is emerging from literature which may take on a variety of facilitating and even entrepreneurial tasks. The purpose of this article is to develop a conceptual framework for the various options at hand, based on an extensive literature review of port authority functions. The framework also identifies the principal governance-related factors that may in practice enable or prevent port authorities, particularly in Europe, from assuming the renaissance ambitions advocated by scholars. The hypotheses developed in this article form the basis of a wider empirical research agenda into reform of port governance in Europe and elsewhere in the world.  相似文献   

16.
江苏沿海港口吞吐量影响因素及预测分析   总被引:1,自引:0,他引:1  
张萍  张守国 《水运工程》2011,(10):63-65
目前江苏沿海地区综合开发已上升到国家发展战略层面,沿海港口建设正在迅猛开展。港口吞吐量的预测对于港口的建设有着极其重要的意义。以港口和腹地之间的互动关系为出发点,分析了可能影响江苏沿海港口吞吐量的若干因素,采用主成分分析法提取了过去10年影响港口吞吐量的最关键因素,剖析了江苏港口发展的内在影响机理,并提出了基于影响机理的预测模型。最后使用模型对江苏港口吞吐量进行验证分析,模型为江苏沿海港口新一轮发展提供了有力的数据支撑。  相似文献   

17.
It is virtually impossible for a US public port authority to be totally proactive in its behaviour since there are too many major factors that affect its future that cannot be controlled or even anticipated by the port staff. Conversely, it is also virtually impossible for a public port authority to be totally reactive since the time window between decision and implementation often exceeds the time window of opportunity. For a public port authority to maintain long-term viability, it must constantly review the facilities it owns, the services it offers, and the source of the revenues it generates. This on-going review should determine how well the Port is adhering to its mission and accomplishing its goals and objectives as set out in the Port's strategic plan. Today, a major management challenge for any viable Port is prioritizing goals and maintaining a policy that ensures clear focus on the highest priority goals. Determining priorities amongst capital projects should be high on the list of any public port authority. This paper provides an overview of the decision-making processes used by American public port authorities in evaluating new capital projects and, we hope, an insight into processes for determining the desirability of expanding, contracting, or terminating present facilities and services.  相似文献   

18.
Procedure violations are commonly identified as an essential causal factor in maritime accidents. This also applies to the Norwegian offshore service vessel sector. This illustrates that there is a need to study compliance and non-compliance in a broad context and to explore the factors that affect the propensity to act in accordance with prevailing procedures. The aim of the present study was therefore to examine the antecedents of safety-compliant behaviour among workers on offshore service vessels operating on the Norwegian Continental Shelf. With reference to a survey of 1108 offshore service vessel workers, this was done by analysing the relationship between a set of predictor variables and a self-report measure of safety-compliant behaviour. Using binary logistic regression analysis, the present study revealed that the safety climate and the vessel workers’ age were positively related to safety compliance, whereas job experience and perceived procedure vagueness were negatively related to safety compliance. Theoretical and managerial implications are discussed. In sum, the findings indicate that shipowners, captains and other stakeholders within the offshore service vessel industry should consider a broad multi-factorial approach to increase safety compliance.  相似文献   

19.
基于供应链思想的第四代港口概念特征及发展策略研究   总被引:1,自引:0,他引:1  
与第一、二、三代港口不同,第四代港口从强调自己是一个“物流中心”,转变为强调是供应链中的一个环节,为此,有必要研究基于供应链管理思想的第四代港口的若干问题。在给出具有供应链管理特征的第四代港口的定义的基础上,提出了港口与供应链关系的演进模型,指出港口与供应链关系发展经历了分离(即相互独立)、整合(即形成港口物流服务链,为制造业供应链提供高效的增值服务)和嵌入(即港口被嵌入到制造业供应链中)三个阶段。应对供应链管理的要求,第四代港口应具有与前三代港口不同的差异化、精益化和敏捷化特征。基于上述分析,第四代港口的发展策略应为,主动整合并构建自身的供应链和与供应链核心企业联合等。  相似文献   

20.
Defining numerical uncertainty is an important part of the practical application of a numerical method. In the case of a ship advancing in short and steep waves, little knowledge exists on the solution behaviour as a function of discretisation resolution. This paper studies an interface-capturing (VOF) solution for a passenger ship advancing in steep (kA = 0.24) and short waves (L w /L pp = 0.16). The focus is to estimate quantitative uncertainties for the longitudinal distributions of the first–third harmonic wave loads in the ship bow area. These estimates are derived from the results of three systematically refined discretisation resolutions. The obtained uncertainty distributions reveal that even the uncertainty of the first harmonic wave load varies significantly along the ship bow area. It is shown that the largest local uncertainties of the first harmonic wave load relate to the differences in the local details of the propagating and deforming encountered waves along the hull. This paper also discusses the challenges that were encountered in the quantification of the uncertainties for this complex flow case.  相似文献   

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