• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.56-60
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• 2002

After many casualties with conventional bulk carriers in recent years, double hull bulk carrier was proposed ta enhance the structural safety of side shell and transverse bulkhead. In this paper, two alternative structural designs of double hull bulk camel were executed based an the Lloyd's rule, and the results were examined in comparison with the existing single hull bulk carrier in the viewpoints of the increase of weight and construction cost. The relative construction concept was used to certify the economical validity of double hull bulk carrier.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.73-78
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• 2004

For the preliminary stages of ship design it is necessary to develop a basic design, which specifies the main particulars of the vessel. based on the requirements given by the owner. An efficient design enables the shipyard to make a rough estimate of the construction costs and to put forward a favourable quote during the call for tenders. The parametric determination of the main particulars of the vessel involves the application of empirical formulae. These formulae have been created after detailed tests and research by maritime research institutions and researchers had been carried out. Here, the design of a medium sized Bulk Carrier (26000t dwt) with a service speed of 17 knots for carrying rice and rock phosphate has been illustrated. Medium sized Bulk Carriers (25,000t dwt - 50,000t dwt) are in steady demand among small shipping companies. They have a size advantage, in that port size restrictions do not affect their design tremendously. Nevertheless, structurally. they are one of the most difficult to build. During design, the rules of the maritime regulatory bodies were strictly adhered to.

• Journal of Ship and Ocean Technology
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• v.3 no.1
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• pp.27-41
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• 1999

The objective of the paper is to study the impact of changing the traditional hull design of bulk carriers by providing them with a double hull while keeping the same deadweight. It is demonstrated that by introducing the double hull the structural reliability is increased throughout the entire life and also the extend of the needed repair is reduced. The results are obtained with recently developed mathematical tools for the reliability assessment of ship hulls subjected to the existence of multiple cracks both in the stiffeners and in the plating and it models the crack growth process. The effect of corrosion is represented as time dependent. The long-term stress range acting on the elements is defined as a function of the local transverse pressure of the internal cargo and outside sea water combined with the stresses resulting from the longitudinal bending of the hull, which is a combined with the stresses resulting from the longitudinal bending of the hull, which is a combineation of horizontal and vertical bending moments. The effect of maintenance actions is modelled as a stochastic process. The results show that a different design of the midship section improves the structural safety and also the economy with respect to structural repair of bulk carriers.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.8-14
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• 1994

The aim of this paper is the introduction and investigation of the characteristics and outline of self-unloading systems from the bulk handling point of view. Some years of experiences from the building of self-unloading bulk carriers are described hereunder.

• Journal of Navigation and Port Research
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• v.42 no.5
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• pp.341-346
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• 2018

Supramax bulk carriers cover a wide range of ocean transportation requirements, from major to minor bulk cargoes. Market forecasting for this segment has posed a challenge to researchers, due to complexity involved, on the demand side of the forecasting model. This paper addresses this issue by using technical indicators as input features, instead of complicated supply-demand variables. Artificial neural networks (ANN), one of the most popular machine-learning tools, were used to replace classical time-series models. Results revealed that ANN outperformed the benchmark binomial logistic regression model, and predicted direction of the spot market with more than 70% accuracy. Results obtained in this paper, can enable chartering desks to make better short-term chartering decisions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.248-252
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• 1995

In this paper, the samples are made by the new three-composition seed grain method, in order to obtain the low voltage varistor distributed randomly large seed grain in its bulk. The oscillation phenomena of carriers appeared from current-voltage characteristics under knee voltage is shown by the transient flow of non trapped carriers group in the trap level of intergranular layer, surface state and/or depletion layer. Current oscillation phenomena is hardly shown in the high electric field. The injected carriers from both electrodes are directly flowed from the conduction band of forward biased grain through the intergranular layer into the reverse biased grain, because the trap level in the electric field above the knee voltage is mostly filled.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.106-111
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• 2005

After many casualties of conventional bulk carriers in recent years, a double hull bulk carrier was proposed to enhance the structural safety of a side shell and a transverse bulkhead. In this paper, two alternative structural designs of a double hull bulk carrier were carried out based on the Lloyd's rule. One has the double sided hull with longitudinal stiffeners and the other has that with a girder. The final structural design was examined in comparison with an existing single hull bulk carrier from the viewpoints of cargo hold capacity and the increases of weight and construction cost. Generally, the construction cost of a ship consists of the costs of material, labor and overhead cost. But, in this study, the relative construction cost concept was introduced to compare the economical validity more precisely. In this concept, fixed overhead cost is excluded in the assessment of construction cost, and only the variable overhead cost is added up to labor cost. As the result of this study, a double hull bulk carrier can be constructed within 1% increase of weight and construction cost.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.151-152
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• 2016

Various studies on Port and Terminal have been conducted to gain the competitive advantage, but they are limited to the bulk terminal than container terminal. Therefore, the study is to analyze the service quality of bulk terminal. The study first finds attributes of bulk terminals through professional groups and brainstorm. This study analyzes the difference between the perception of the actors such as carriers, forwarders and shippers, using a bulk terminal. The result shows that all service quality factors have a significant effect on the satisfaction.

• Journal of the military operations research society of Korea
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• v.12 no.1
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• pp.78-86
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• 1986

This paper analyzes how a shipowner or charterer may determine the specification of optimal ship size for a given route with respect to certain market requirements. The theory of optimal ship size, a methodology for estimating scale economics, and the various factors affecting ship size are examined using a typical conventional cargo ship and bulk cargo carriers based on shipowners' cost data.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.69-77
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• 2000

This study was a part of FSA study which was initiated by IMO and was applied to hatchway watertight integrity of bulk carriers. Hazards which were involved in high risk level were identified as follows. Ship Operation out of Design Criteria(Hatch Coaming Damage) and Poor Maintenance & Inspection(Securing Arrangement Damage). The potential risk was calculated by risk analysis and risk control option was made to reduce potential risk. The potential risk was about U$60,000/ship-year and could be reduced to about U$30,000/ship-year by applying RCO 1(Advanced system directly related to Hatchway Security). In addition, effectiveness of RCOs was shown by cost benefit assessment.