• Journal of the Society of Naval Architects of Korea
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• v.34 no.4
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• pp.84-90
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• 1997

The paper is mainly concerned with the applications tn develop an optimum structural design procedure for hatchcoverless container ship. L.R rules are applied to determine the scantlings of the longitudinal members. As for an object function of midship section design, the total sectional area of all the longitudinal members for midship section is selected. The SUMT procedure combined with direct search method is applied to the solution of nonlinear optimum design problem to find a optimum midship section arrangement. The results of optimization study show that the weight of model ship may be saved about 8.0% per unit length.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.5
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• pp.507-512
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• 2011

This study is concerned with the reliability analysis and its based design of midship section against the ultimate bending strength. Eight bulk carriers and seven oil tankers over 100m length are chosen for the present study. Target reliability indices for the two ship types have been derived based on the results reliability analysis of the present ship models. Reliability-based structural design codes are proposed for use in design of midship section of bulk carriers and oil tankers. The design codes proposed in this study have been successfully applied to re-design of midship section of the present ship types. It has been found that the proposed codes can provide more uniform structural design results.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.173-178
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• 1992

This paper is in principle concerned with the reliability analysis and its based design of midship section against the ultimate bonding strength. Bulk carriers and oil tankers over 100m length are considered for this study. Target reliability indices are derived with the results of reliability analysis of the present ship models. Reliability-based structural design code formats are proposed for use in design of midship section of bulk carriers and oil tankers. The proposed design formats have been success fully applied to re-design of midship section of the present ship types and show the reasonable results. It has been found that the proposed code formats in this paper are useful for the re-deign of midship section of such ship types.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.56-65
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• 2001

The structural model of midship section is within the scope of STEP AP218. It supports to represent the ship structure, but most of shipyards and classification societies exchange the information using 2D drawings at the present. To translate the 2D information into the ship structure model of STEP AP218, we analyze the 2D midship section information of KR-TRAS of Korean Register of shipping, and include the transverse members information with the 3D model. We also define the mapping table and the mapping relationships between two data structures. With this mapping table we develop the translator for the midship section, and visualize the translated ship structure model using a STEP viewer. The ship structure model can be used to exchange information between design departments, and through the lifecycle of design, analysis, and maintenance.

• Journal of Ship and Ocean Technology
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• v.5 no.3
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• pp.27-35
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• 2001

In this research, hybrid method with case-based reasoning and rule-based reasoning is applied. Using case-based reasoning, design experts'experience and know-how are effectively represented in order to obtain a proper configuration of midship section in the initial ship design stage. Since there is not sufficient domain knowledge available to us, traditional case-adaptation algorithms cannot be applied to our problem, i.e., creating the configuration of midship section. Thus, new case-adaptation algorithms not requiring any domain knowledge are developed antral applied to our problem. Using the knowledge representation of DnV rules, rule-based reasoning can perform deductive inference in order to obtain the scantling of midship section efficiently. The results from the case-based reasoning and the rule-based reasoning are examined by comparing the results with various conventional methods. And the reasonability of our results is verified by comparing the results wish actual values from parent ship.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.115-124
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• 1993

A structural system reliability analysis is studied for the safety assessment of midship section. Probabilistically dominant collapse modes are generated by Element Replacement Method and Incrimental Load Method. In order to avoid generating the same modes repeatedly, it is branched at final plastic hinge. Using first and second order bound methods, system failure probability of midship section is computed and compared with deterministic load factor method to show the usefulness of the proposed method.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.1
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• pp.1-13
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• 1992

The objective of this study is to develop knowledge-based system for the preliminary design and midship section design of bulk carrier and to enhance the applicability of knowledge engineering in the field of Naval Architecture. First, expert system shell called E.1 is developed in C language. E.1 supports backward-chaining, automatic iteration procedure and reiterative inference mechanism for efficient application of knowledge-based system in structural design. Knowledge representation in E.1 includes IF-THEN rules, 'facts'and 'tables'. Second, knowledge bases for the principal particulars and midship section design are developed by experimental formula, design standard and experiential knowlege. Third, hybrid system combined this knowledge-based system with the optimization program of midship section is developed. Finally, the simplified design method utilizing the regression analysis of the optimum results of stiffened plate is developed for facilitating the design process. Using this knowledge-based system, the design process and results for Bulk carrier and stiffened plates are discussed. It is concluded that knowledge-based system is efficient for preliminary design and midship section design of the ship. It is expected that the performance of the CAD system would be enhanced if the better knowledge-base is accumulated in the E.1 tool.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.2
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• pp.44-55
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• 1996

Since the use of computer for the ship structural design around mid 1960``s, specially many researches on the midship section optimum design were carried out from 1980. For a rule-based optimum design case, there has been a problem of handling a discrete design variable such as plate thickness for a practical use. To deal with the discrete design variable problems and to develop an effective new method using artificial neural network for the ship structural design applications, Neuro-Optimizer combing Hopfield Neural Network and other Simulated Annealing is proposed as a new optimization method and then applied to the fundamental skeletal structures and Midship section of Tanker. From the numerical results, it is confirmed that Neuro-Optimizer could be used effectively as a new optimization method for the structural design.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.135-144
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• 1996

In this article, an Expert System for MIDship section design(ESMID) is developed based on a general-purpose expert system shell. The system focuses on the integration of knowledge-based system and design resources such as an engineering database, graphical user interface, and engineering application program for the calculation of section modulus and longitudinal strength of ship structure. The validation of the ESMID system was examined and verified by applying the system to the 64K bulk carrier. The developed expert system can help a novice engineer in designing the midship section of ship.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.188-192
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• 2004

A Numerical analysis method is developed in order to compute the flaw and wave field for 2-dimensional floating body in the free roll motion with 3 degrees of freedom. Navier-Stokes and continuity equations are gaverning equations in tire present study. Finite Difference method is introduced to discretize the governing equation. The free surface is traced by the interface tracking method and the grid system is fitted to boundaries including free surface and body surface, which is moving in the flow field. The numerical scheme is based on Maker and Cell method. For the sake of validation of the numerical method, the computed roll decay factors according to tire midship section shapes are compared with measured results. The numerical results are discussed in order to understand the effect of midship section shape on roll motion.