Implementing coastal zone management: 1972–1990

Abstract

The implementation history of the Coastal Zone Management Act offers insights into the process of long‐term intergovernmental policy implementation. This five‐stage history is explained as a coproduction process, in which coastal state, environmental, and development advocacy coalitions interacted with congressional committees and the federal coastal office to shape coastal policy and manage coastal development. The coproduction approach proved invaluable during the Reagan assault on the coastal program, when the states and Congress assumed responsibility for keeping the program alive. Acknowledging underlying stakeholder dynamics as the basis for coastal program evaluation could strengthen future coastal management implementation.     

Hydrodynamic Performance Study of Wave Energy–Type Floating Breakwaters

Journal of Marine Science and Application - The integration of wave energy converters (WECs) with floating breakwaters has become common recently due to the benefits of both cost-sharing and...     

Power efficient formation configuration for centralized leader–follower AUVs control

Autonomous underwater vehicles (AUVs) have rapidly developed in the last few decades due to their autonomous properties in the investigation of an underwater environment. The goal of this paper is to develop a power efficient formation control for the cooperative motion of AUVs with a support vessel as a leader. In this paper, a kinematic algorithm for the joint motion of an AUV with a support vessel was developed and that algorithm was expanded for the formation of AUVs. The AUV yaw, surge and sway control loops were designed for that purpose. The complexing navigation system structure for the AUV was also developed. Simulation results demonstrated efficiency of the proposed kinematic algorithm for the joint motion of AUVs. Also, influence of lateral ocean current was considered. After development of the centralized leader?Cfollower formation control for the group of AUVs with a support vessel as a leader, we optimized a formation configuration in terms of power efficiency. Drag forces caused by AUV motion in the water can significantly influence power consumption. We investigated the relationship between the AUV's formation configuration, underwater coverage efficiency, communication quality and power consumption. As a result of research, we proposed a power efficient formation configuration for typical underwater operations. As a result, the effect of the AUV formation configuration on the power consumption was investigated and a trade-off solution for the optimal AUV positions in formation with minimal energy consumption, high coverage efficiency and small communication power consumption was derived.     

Finite element damage analysis of an underwater glider–ship collision

Underwater gliders, which are profiling autonomous underwater vehicles designed to make oceanographic measurements, are increasingly used in the coastal ocean. As they regularly surface for data transmission, gliders increasingly pose a risk for fast ships. In order to estimate the extent of damage due to collision, 3D finite element simulations of collisions between a glider and a high-speed craft with a glass-fiber reinforced plastic hull are performed. Different collision scenarios such as impact locations, angles of attack and speeds are examined. The results are compared to an analytical solution based on simplifying assumptions. Although both methods reveal consistent results, it is shown that finite element simulations are required to account for the 3D shape of the ship. The results indicate that at ship velocities exceeding 7.5 m/s (14.6 kt) the glider penetrates the ship’s hull causing severe damage to its structure.     

The efficiency of congestion charging: Some lessons from cost–benefit analyses

This paper addresses methodological issues in cost–benefit analysis (CBA) regarding congestion charging schemes. Despite suspicion on the reality of travel time savings, it is argued that these savings are a conservative value of surplus gained from a congestion scheme. The methodology of measurement of travel time reliability is not yet stabilised, but the literature review suggests that it may take a growing share of benefits in the future. Sensitivity tests performed on the London and Stockholm case studies with a simulation model underline the need to accurately measure speeds, while the value of travel time appears less critical. Finally, the impact of costs of public funds on public accounts is greatly significant and may increase in the future.     

A local model for the simulation of two–dimensional spilling breaking waves

A numerical model for the simulation of two dimensional spilling breaking waves is described. It is derived from a previous model which, in turn, takes its underlying ideas from the Cointe and Tulin theory of steady breakers. With respect to the former model, the present one is local, i.e., the inception, extension, and geometry of the breakers are determined through the local shape of the water surface. The model has been implemented in a RANSE code, which was developed for the simulation of ship flows, through a modification in the boundary conditions. This yields a simple and effective way to reproduce the breakers influence on the underlying flow. The resulting code has been used to simulate the flow past a submerged hydrofoil. The numerical results are compared with those of the previous model and with the experimental data obtained by Duncan.     

基于FLUENT网–栅结构围油栏拦油特性数值实验

为研究网-栅结构围油栏拦油性能,基于不可压缩黏性流体的N-S方程和流体体积分数方法(VOF),利用FLUENT软件进行数值实验。在不同流速下,对其临界失效速度进行了验证;拦网孔隙率变化,对网–栅结构围油栏拦油特性影响不大;溢油区域相对围油栏初始位置的不同,对围油栏拦油效果则有显著影响。在实际应用中,应当注意网–栅结构围油栏的使用环境,合理确定围油栏的布设位置,防止不必要的拦油失效情况发生。     

Linking ocean container carrier capabilities to shipper–carrier relationships: a case study

ABSTRACT

As outsourcing and offshoring continue to expand, the ocean container industry serves a critical and still increasing role in supporting global trade. Yet, perceived commoditization and intense price competition among ocean container carriers limit opportunities for competitive advantage and formation of long-term shipper–carrier relationships. This environment ultimately yields an unhealthy industry that threatens the stability of global supply chains. Extant literature provides limited insight into how carriers can build strong relationships with shippers to overcome the short-term, transactional-orientation of the industry. Examining a case study of a major ocean container carrier, we apply structural equation modeling to shipper survey data to explore how carrier operational, service, and pricing capabilities influence the strength of the long-term shipper–carrier relationship. Furthermore, we identify unique clusters of shipper needs, helping the carrier understand when and how to promote a particular portfolio of capabilities to customers.     

A study on slamming pressure on a flat stiffened plate considering fluid–structure interaction

Normally, the design slamming pressure on the bottomof a semi-submersible-type floating rig is determined in a simple way using the relative speed obtained from an air-gap analysis. However, few studies have taken a thorough, robust, and deep-background approach to the estimation of design pressure. To investigate the slamming pressure on the bottom of a semi-submersible rig, a simplified deformable stiffened plate of a zero-degree deadrise angle is simulated using the nonlinear FEM software LS-DYNA, which can take the influence of fluid–structure interaction (FSI) into account. Various parametric studies are carried out to examine the effects of structural flexibility, coupling stiffness, mesh size, velocity, stiffener size, and air cushion. The pressure response on the plate by the coupling of fluid and structure is studied and the FSI effect of each parameter is discussed. Then, equivalent transient and static loads that result in the same maximum or permanent deformation as FSI are evaluated for design purposes through a series of parametric studies.     

基于船舶–流场耦合作用的内河航段船舶航行虚拟辅助驾引

[目的]为进一步提高船舶航行的安全性,对船舶辅助驾驶决策相关内容开展研究。[方法]针对选取的两段内河典型航段,基于实时数字航道流场信息,考虑航行规则约束,模拟船舶–流场耦合作用下的复杂流场航段虚拟辅助驾引。模拟南京和东流航段的虚拟辅助驾引,给出相应的安全驾驶方案,在航行过程中对船舶速度、位置和航向等信息进行实时追踪。[结果]仿真结果表明,基于Fluent二次开发的船舶–流场耦合作用的算法可有效解决船舶多自由度运动耦合和船舶–流场多物理场耦合的解耦问题;遇见弯道或分汊时,操小舵角长距离航行可以在避免降速和较大横移的同时实现船舶的安全航行。[结论]该算法可以有效对接数字航道流场信息,开展复杂流场环境下内河航段船舶航行的过程模拟,结果可为内河航段船舶智能航行决策提供数据支撑。     

Market structures and competitive strategies: the carrier–stevedore arm-wrestling in northern European ports

Over the last few years, liner and stevedoring markets have been facing new challenges. The progressive concentration on the demand side (carriers) and the emergence of global alliances in the mid-1990s have triggered a similar process of consolidation on the supply side (stevedores). In turn, more recently, the strategic choices of pure terminal operators have led to the progressive involvement of carriers in port operations, both from a financial and a managerial point of view. This paper aims at analysing the current contest in northern Europe between customers and suppliers of port services. Substantial concentration in the stevedoring market and the emergence of dedicated facilities in that area, make this arm-wrestling stronger and stronger.

At present, the liner market is following a number of strategic directions including the pursuit of economies of scale (larger vessels) and the supply of services using faster vessels (deployment of ‘fewer’ assets) in order to offer either new services or additional loops (scope). By exploring the strategic behaviours of the top carriers (‘bigger’ or ‘more effective’), the paper attempts to outline the future evolution of the two industries in a 2015 vision, highlighting in particular scenarios for north European ports. Global alliances are weakening and a new era of M&As is probably approaching: how will the bargaining power change between port users and port customers? Which competitive paradigm will dominate?     

Transport infrastructure provision and operations: Why should governments choose private–public partnership?

Recent transport sector liberalisation, as well as global economic crisis, is favouring the implementation of transport infrastructure projects through Public–Private Partnerships (PPP). However, there is a debate as to whether PPP schemes are a better option than conventional procurement. To this end, an evaluation framework is proposed, to assess which of these two alternative schemes for transport projects financing is preferable for the public. The proposed framework is complimentary to the Value for Money (VfM) approach and is based on a Multi Criteria Analysis (MCA). The first step is the estimation of the Public Sector Comparator (PSC) for the case of conventional procurement, dealing with construction, maintenance and operation costs revenues, as well as any costs associated with risks undertaken by the public. As for the PPP case, it includes any payments by the public sector and related risks costs. The MCA is then applied only if the PPP is found preferable for the public sector. The latter considers additional impacts, including among others the social attributes of a particular scheme, job creation, environmental impacts and safety and security aspects. The proposed framework was applied to a pilot Bus Rapid Transit (BRT) corridor infrastructure project in the city of Indore, India, in order to demonstrate its validity. The framework and its application could provide useful guidance when considering PPP for a transport project, since it demonstrates in a transparent way the society's attitude towards this project, something that is critical to its acceptance.     

Can clusters be bi-polar? Exploring the case of the Piraeus port–maritime cluster

ABSTRACT

Further to being Greece’s biggest port, Piraeus has been a traditional pole of attraction for a plethora of organisations, companies, and institutions engaged in port- and shipping-related activities. Regional development literature has already indicated that the benefits deriving from adjacency and agglomeration economies are maximised when individual entities are organised in forming business clusters. Therefore, the paper critically addresses the existence of theoretical preconditions to a competitive port–maritime cluster formulation in wider Piraeus area. Based on a thorough review of cluster theory, the basic characteristics of clusters are identified to provide the analytical tools for examining the geographical concentration and economic specialisation in Piraeus. Field research in the form of in-depth interviews with leading shipping- and port-related business representatives and institutional bodies and the analysis of qualitative and quantitative data collected revealed that necessary preconditions for successful cluster formulation are met despite the inexistence of a formally recognised cluster. Two distinct poles of economic activity (shipping and port related) are recognised, demonstrating differentiated clustering behaviours and patterns of interaction with other players. The paper concludes with proposals deriving from this dual cluster structure and governance and the need for innovative, differentiated strategies.     

A coupled FDM–FEM method for free surface flow interaction with thin elastic plate

A partitioned approach by the coupling finite difference method (FDM) and the finite element method (FEM) is developed for simulating the interaction between free surface flow and a thin elastic plate. The FDM, in which the constraint interpolation profile method is applied, is used for solving the flow field in a regular fixed Cartesian grid, and the tangent of the hyperbola for interface capturing with the slope weighting scheme is used for capturing free surface. The FEM is used for solving structural deformation of the thin plate. A conservative momentum-exchange method, based on the immersed boundary method, is adopted to couple the FDM and the FEM. Background grid resolution of the thin plate in a regular fixed Cartesian grid is important to the computational accuracy by using this method. A virtual structure method is proposed to improve the background grid resolution of the thin plate. Both of the flow solver and the structural solver are carefully tested and extensive validations of the coupled FDM–FEM method are carried out on a benchmark experiment, a rolling tank sloshing with a thin elastic plate.     

Analytical investigation of marine casualties at the Strait of Istanbul with SWOT–AHP method

The Strait of Istanbul is one of the most dangerous and busiest sea passages, according to its narrowness, sharp turns, currents, heavy traffic and many other important factors. Despite the latest precautions, marine incidents still occur, especially in narrow seaways. This study shows that a management tool that is specifically applied for reducing marine casualties and consequently enhancement of safety and ship management performance can be used to prevent accidents and casualties in maritime transportation. In this study, factors which affect marine casualties examined and determined with SWOT (strengths, weaknesses, opportunities and threats) analysis method and weighting of the factors determined by using the AHP (analytic hierarchy process) method. With this approach, strategic action plans were developed for minimizing shipping casualties at the Strait of Istanbul, taking into account the weighting factors and previously happened accidents.     

Testing the Effects of Constraints on Climate Change–Friendly Behavior among Groups of Australian Residents

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.     

Overseas trade vis-a-vis overseas shipping: Growth and performance in India (1999–2009)

Maritime trade has been and even continues to account for about a lion's share of India's total cargo volumes. Despite the growth of multimodal transport (by land, water and air), shipping still continues to be the major mode of transport in the bulk carriage of country's overseas trade. In view of this vital role of shipping, in the first four decades of independence, under the initiative of planned development and active government support, India's shipping and port sector saw dramatic growth in their performance to build adequate national fleet, in keeping up with the transport of overseas cargo. However, the onset of economic liberalization in 1991 has given rise to many new dimensions in the development of the shipping and port sector of the country with a significant redefinition of shipping and port services, in response to the new global trend patterns. For instance, it has also established the new era of containerization in the mode of cargo delivery from the dominance of the era of bulk and break-bulk trade during the decade of sixties and seventies. Moreover, as global competition increases, in response to this emerging trade patterns within this country, India's volume of traffic growth also increases manifold. So, India's shipping and port sectors need, significantly, to build up and furnish their capacity by increasing the frequency of this mode of transport i.e. the growth of the national overseas fleet to meet this surging demand. This paper, therefore, have focused on this role of shipping in such rising overseas trade, with a view to examine the shipping performance (the growth of overseas fleet) in response to the growing overseas trade at all ports of India during the period (1999–2000 to 2008–2009), in terms of both a mathematical model and a graphical representation. Finally, it concludes that the absolute overseas trade, being highly import dependent, have led to a more or less stagnant performance in overseas shipping, owing to the lack of the adequate growth of absolute overseas exports during this period.     

“The Geography of Maritime Transport–Space as a Perspective in Maritime Research and Development”

Emissions from commercial shipping are currently the subject of intense scrutiny. Among the top fuel-consuming categories of ships and hence air polluters are container vessels. The main reason is their high service speed. Lately, speed reduction has become a very popular operational measure to reduce fuel consumption and can obviously be used to curb emissions. This paper examines such an operational scenario. Since time at sea increases with slow steaming, there is a parallel and strong interest to investigate possible ways to decrease time in port. One way to do so is to reduce port service time. Another possible way to minimize disruption and maximize efficiency is the prompt berthing of vessels upon arrival. To that effect, a related berthing policy is investigated as a measure to reduce waiting time. The objective of reducing emissions along the maritime intermodal container chain is investigated vis-à-vis reduction in operational costs and other service attributes. Some illustrative examples are presented.