Calculating the return value using a mathematical model of significant wave height

This study presents a new method for calculating return values. The essence of the method is that it utilizes nonstationary data to calculate the return value for a region in the Northeast Pacific. The nonstationary data was obtained from a model which was previously developed for the behavior of the significant wave height as a function of time in the region. The method is illustrated by convolving two generalized Pareto distribution functions fitted to two parts of the model, computing a suitable extreme value from the new distribution function, and calculating the return value using this extreme value.     

Climate change and the future Maritime Policy for the EU

A cross-cutting Maritime Policy can ensure that climate change threats and challenges in regards to seas and oceans are dealt with in a wide policy framework that takes into account the impacts that climate change may have on other sectors and vice versa.     

Fundamental research on resistance reduction of surface combatants due to stern flaps

It is well known that a decrease in ship resistance may be achieved due to the installation of a stern flap. Therefore, so far, a considerable amount of research on stern flaps has been conducted. Previous research has demonstrated that the primary mechanism by which a stern appendage reduces resistance is a change in the pressure distribution over the aft body of the hull, and secondly through effects on the running attitude, near and far field wave generation, and local transom flow among other phenomena. However, the change in pressure distribution is influenced by the other components. Hence, there is still room for argument about the relative contribution of each component to the pressure distribution. Therefore, as the first step of the research, by conducting the model experiment in towing tank and CFD (Computational Fluid Dynamics) analysis, we examined the effect of running attitudes and wave making at the after portion of the hull on resistance reduction. As a result, it is concluded that a flap affects a change in the wave generated at the transom part and it could lead to a decrease in wave-making resistance.     

The Gulf Stream, rings and North Atlantic eddy structures from remote sensing (Altimeter and SeaWiFS)

Seasonal SeaWiFS chlorophyll a concentrations cycles and annual changes of altimeter Sea Level Anomaly are derived for the subtropical North Atlantic near  35°N and along a Gulf Stream axis. Spatial structure of SeaWiFS, is defined in terms of deviations from a local seasonal cycle and examined in relation to altimeter eddy structure. In the subtropical region near 35°N, SeaWiFS structure is evident during the spring bloom period with a scale of  430 km, or about twice the eddy scale. A Gulf Stream axis has been selected as a region where the Sea Level Anomaly variance is a maximum. Eddy propagation speeds and scales are examined. Cold-core (cyclonic) rings correspond to areas of high SeaWiFS chlorophyll a. Warm-core (anticyclonic) rings relate to areas of low chlorophyll concentration. Both SeaWiFS structure and eddy structure have a spatial scale of  450 km or twice the ring scale along the Gulf Stream axis. SeaWiFS chlorophyll anomalies and Altimeter Sea Level Anomaly structure have an overall negative correlation coefficient of r = − 0.34. Swirl currents between eddies redistribute surface chlorophyll concentrations and can spatially bias maximum and minimum concentration levels off eddy centre.     

Sharing piping CAD models of ocean plants based on international standards

In the shipbuilding industry, different computer-aided design (CAD) systems are used for different design domains, structure, and outfitting. We need to exchange data among different CAD systems such as Tribon, AutoCAD, Intergraph or PDMS to complete the whole design and production process. There are two approaches to data exchange. One is direct translation; the other is indirect translation, which is based on a neutral format. If we use a neutral format, the data specification is open to the public and the design model can be used by other CAD systems, including next-generation CAD systems. In this paper, we propose an indirect method that uses ISO 10303 (STandard for the Exchange of Product model data) AP227 and ISO 15926 to define neutral formats. A separate ShapeDB is constructed to manage the geometry information, referenced to the catalogue data defined by ISO 15926. An experimental implementation for data exchange between Tribon and PDMS is described.     

Graph based signal-behavior-structure mapping for state maintenance of equipment

Equipment has dual nature: physical objects existing in nature, and artificial objects designed by human. The decision on the configuration and structural parameters of equipment is made by engineers based on technical-physical effects which control the behavioral parameters of the equipment. Sensors are mounted on the equipment to monitor the equipment state. Current methods for state monitoring and diagnosis mostly use mathematics and artificial intelligence technology to construct evaluation methods. This paper presents an integrated design and state maintenance method, in which graph and dual graph are used for recording design data and sensor arrangement and for mapping method from signals to substructures and connection pairs. An example of state maintenance of hydro power generating equipment is illustrated.     

Proficiency improvement method in maritime education

The research conducted by the International Maritime Organization (IMO) shows that maritime education not always reaches its pre-established goal. One of the aspects in maritime education development process with the aim to prepare ship officers and other specialists is a thorough selection of the learning content according to real life necessities. Structuring the learning content of the subjects, both significant to profession and conforming to the requirements set by professional bodies, is one of the key issues addressed by curriculum developers. The aim of this research is to create a model for the curriculum development in scientific subjects for outcome-based maritime education. The main criterion which determines the significance/contribution level of the included topic in the curriculum is the anticipated learning outcome increasing the level of proficiency in students. Thus, the present research unveils the necessary steps for the evaluation of the proposed topics in the context of teaching/learning and gives grounds for their selection and the arrangement of topics in a logical order for further implementation in teaching/learning process. The present research is illustrated by a case study concerning the development of teaching/learning content for chemistry curriculum as a study subject in the secondary vocational maritime education programme.     

Sustainable procurement and environmental life-cycle costing in maritime transport

Transportation sector, including maritime transport, exerts significant environmental impact. Public procurement as a policy strategy instrument which applies to the purchase of transport means, construction of infrastructure and the provision logistic services in supplying the goods, services and executing of works must integrate environmental considerations in the contract award procedures. While conventional life-cycle costing (LCC) is based on four categories to be assessed e.g. investment, operation, maintenance and end-of-life disposal expenses, the environmental LCC method also takes into account the external environmental costs. The paper is focused on sustainable public procurement and environmental life-cycle costing aspects of EU 2014 Directive. Analysis is made of the real cost of procurement, the externalities and the impact of maritime transport sector on the environment. The purpose of this research is to propose the framework for assessment of integral impact on the environment which combines environmental LCC approach with TBL concept using non-monetary units for measuring externalities. The authors advocate clean and energy-efficient maritime transport ensuring effective implementation of environmental policy objectives and targets and emphasize the role of public authorities and entities in fostering the inclusion of environmental externalities in calculation of LCC.     

Analysis of ship drifting in a narrow channel using Automatic Identification System (AIS) data

With maritime transportation has played an important role in global economy development, ship traffic has become more congested. Therefore, ships navigate under risk conditions, and thus maritime accidents have occurred frequently. Especially, ship passing through a narrow channel is even more dangerous. Because, the ships are easy to be affected by external forces such as wind and currents that can cause ship drifts. Many latent risks are present during navigation. In order for the development of a sensible and appropriate traffic model for the safety and efficiency ship navigation, this study has focused on the actual ship behavior to understand the ship drift in the Kurushima Strait, Japan, which is one of the most dangerous routes in Japan. The analysis of ship behavior was carried out using the Automatic Identification System (AIS) data. As a result, the ships drift was understood in detail, and the latent risk was unveiled when ships pass through the narrow route. Moreover, the risk areas were obtained and visualized by the ship drift behavior analysis. The obtained results can be applied to ensure safe navigation and the development of an eco-friendly and economy efficient for ship navigation.