The distribution of the benefits of waterfront reform

In this paper we introduce, for the first time, a methodology from the most recent literature of finance to reveal the duration of shipping cycles and then show the benefit of the use of this information to make more successful shipping loans. This is so as banks are willing to finance, during boom periods, shipping loans for new buildings but by this way ‘create’ oversupply and thus depress the freight market by their own actions. The information about cycles, especially their forecasting, is mostly important as shipping loans are based on project financing/cash flow financing, which means that ship revenue is of utmost importance. The Rescaled Range Analysis is applied here to 379 monthly freight trips—made stationary—between 1971 and 2002 (July), due to Hurst 1 Hurst, HE. 1950. Long-term storage capacity of reservoirs. April1950. pp.770–808. American Society of Civil Engineers. Paper No. 2447 [Google Scholar] and elaborated and popularized by Mandelbrot 2 Mandelbrot, BB. 1975. Stochastic models for the earth's relief, the shape and the fractal dimensions of the coastlines, and the number-area rule for islands. Proceedings of the National Academy of Sciences. 1975, USA 72. pp.3825–3828. [Crossref] , [Google Scholar]. The most important effect, however, is that shipping freight series exhibit non-normality and long-run dependence rendering the use of random walk models such as GARCH (Generalized Autoregressive Conditional Heteroscedasticity) problematic. Thus an adequate literature review is carried out with criticism against the models used. The cycles have been calculated as equal to 4.5 years and 2.25 years. This is almost compatible with the most recent paper of Stopford 3 Stopford, M. 21 September 2001. “Forecasting the dry bulk, tanker and container markets”. In Maritime Cyprus 21 September,  [Google Scholar]. The Hurst exponent was found equal to 0.93, alternating over the periods examined (0.65, 0.73, 0.62, 0.59 and 0.55) and indicating long-term persistence but seriously away from normal/random walk domain. Most studies have said the same using the Jarque--Bera test for normality but provided no alternative.     

The rationality of conference pricing and output policies. Part 2

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.     

Groups in DEA based cross-evaluation: An application to Asian container ports

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: 567–578. [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.     

Designing Coastal Management Strategies for Populations with Distinct Needs: The Case of Learning Disabilities

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.     

Fatigue crack growth behaviour of A5083 series aluminium alloys and their welded joints

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.     

Robust aspects in dependable filter design for alignment of a submarine inertial navigation system

The strapdown inertial navigation system (SINS) is able to provide continuous estimates of a vehicle??s velocity, position and attitude. As a rule, the SIMS component known as a high accuracy strapdown inertial measurement unit (SIMU) is an exceptionally expensive system. Less expensive SIMUs comprised of low cost sensors suffer from degraded performance, but this can be compensated for, in part, by addition of a velocity data recorder (VDR) to accompany the SINS. In this configuration, the need frequently arises to align the SINS of a submarine to in order to avoid a long run-up of the inertial system before a start command is issued. This in-motion alignment (IMA) can be accomplished by integrating SINS data with some external aiding source, such as the VDR, by using some form of measurement matching method. Accordingly, this paper demonstrates a consistent IMA scheme for a low-cost SIMU using a robust Kalman/ $ H_{\infty } $ filter structure. An error model of the SINS is derived in which the state vector includes attitude, velocity, position and sensor errors. Velocity information from the VDR is used as a measurement to the proposed filter. All significant equations concerning navigation are presented in conjunction with argument. Results show the advantages of the approach and emphasize diverse aspects of the SINS.     

The method of imbedded Lagrangian element to estimate wave power absorption by some submerged devices

A simple approach is described to estimate the wave power absorption potential of submerged devices known to cause wave focusing and flow enhancement. In particular, the presence of a flow-through power take-off （PTO） system, such as low-head turbines, can be accounted for. The wave radiation characteristics of an appropriately selected Lagrangian element （LE） in the fluid domain are first determined. In the limit of a vanishing mass, the LE reduces to a patch of distributed normal dipoles. The hydrodynamic coefficients of this virtual object are then input in a standard equation of motion where the effect of the PTO can be represented, for example, as a dashpot damping term. The process is illustrated for a class of devices recently proposed by Carter and Ertekin （2011）, although in a simplified form. Favorable wave power absorption is shown for large ratios of the LE wave radiation coefficient over the LE added mass coefficient. Under optimal conditions, the relative flow reduction from the PTO theoretically lies between 0.50 and 1 2 ≈ 0.71, with lower values corresponding to better configurations. Wave power capture widths, the sensitivity of results to PTO damping and sample spectral calculations at a typical site in Hawaiian waters are proposed to further illustrate the versatility of the method.     

“Blue” social capital and work performance: anthropological fieldwork among crew members at four Danish international ships

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.     

Non-intrusive polynomial chaos for efficient uncertainty analysis in parametric roll simulations

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.     

An Assessment of Integrated Coastal Management Governance and Implementation Using the DPSIR Framework: KwaZulu-Natal,South Africa

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.     

An experimental/numerical approach for evaluating skin friction on full-scale ships with surface roughness

For an accurate evaluation of the increase in skin friction due to various surface topographies on ships, i.e. plate roughness, coatings, or bio fouling, both experimental measurements and a numerical evaluation of those measurements are necessary. The measurements are necessary as no other practical method exists to evaluate the skin friction coefficient on most surface topographies, and numerical evaluation is required to compute the roughness effects of varying ship types and speeds. Therefore, a method for measuring the skin friction coefficient for bio-fouled and structured surfaces at full-scale friction velocity is presented, and a validation of the design and measuring procedures is given. For the ship frictional resistance calculations, the Computational Fluid Dynamics (CFD) code ShipFlow has been modified to take the added friction into account.     

Simultaneous detection of the nonlinear restoring and excitation of a forced nonlinear oscillation: an integral approach

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.     

Coping with Captivity in a maritime hijacking situation

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.     

Melnikov integral formula for beam sea roll motion utilizing a non-Hamiltonian exact heteroclinic orbit: analytic extension and numerical validation

In the research field of nonlinear dynamical system theory, it is well known that a homoclinic/heteroclinic point leads to unpredictable motions, such as chaos. Melnikov’s method enables us to judge whether the system has a homoclinic/heteroclinic orbit. Therefore, in order to assess a vessel's safety with respect to capsizing, Melnikov’s method has been applied for investigations of the chaos that appears in beam sea rolling. This is because chaos is closely related to capsizing incidents. In a previous paper (Maki et al. in J Mar Sci Technol 15:102–106, 2010), a formula to predict the capsizing boundary by applying Melnikov’s method to analytically obtain the non-Hamiltonian heteroclinic orbit was proposed. However, in that paper, only limited numerical investigation was carried out. Therefore, further comparative research between the analytical and numerical results is conducted, with the result being that the formula is validated.     

Hydrodynamic performance of multiple-row slotted breakwaters

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.     

Experimental study on reflection coefficient of curved perforated plate

A set of experiments is carried out in a towing tank to study the effects of the curvature of perforated plates on the wave reflection coefficient (C _r ). The curvature of a perforated plate can be changed by rotating a reference perforated plate aboutits origin according to the parabolic equation y=?x ². A plunger-type wave maker is used to generate regular waves. The reflection coefficients are calculated using Goda and Suzuki’s (1976) method. The results are compared with those of vertical or sloped passive wave absorbers. The comparison shows that a perforated plate with a curved profile is highly efficient in terms of reducing the wave reflection coefficient. A correlation is established to estimate the reflection coefficient of curved perforated plates as a function of both flow and geometry characteristics.     

Investigation of springing in ship structures using experimental methods and 3-D hydroelastic theory

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.     

Study on the preciseness of hot spot stress of web-stiffened cruciform welded joints derived from shell finite element analyses

A new simple and accurate shell FE-based structural Hot Spot Stress (HSS) determination method for web-stiffened cruciform joints has been proposed. Local stress of welded joints in full-scale bulk carrier (BC)’s lower stool models subject to bending and pressure loadings are examined. HSSs determined by the proposed method are compared with those derived by Lotsberg’s method and the conventional 0.5t-1.5t extrapolation. As results, following are found:

(1)

The local stress of full-scale BC lower stool models with various stool angle and plate thickness can be calculated accurately solely from shell FE results by means of the proposed method.

(2)

HSSs of welded joints in full-scale BC lower stool models subject to bending and pressure loadings derived by the proposed method show good agreement with the target HSSs determined from fine solid models. This demonstrates the validity of the proposed method for actual ship structures under the real load.

(3)

The excessive safety allowance of HSS determined by the conventional 0.5t-1.5t extrapolation can be reduced substantially by adopting Lotsberg’s method or our proposal. The proposed HSS determination method gives more accurate estimates compared to Lotsberg’s method under the conditions chosen, and the application range of the proposed method is equal to or wider than Lotsberg’s method.