• Journal of Ship and Ocean Technology
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• v.3 no.3
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• pp.13-24
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• 1999

In this paper, a 2-dimensional novel beam element is developed and a method to replace the 3-dimensional analysis with 2-dimensional analysis is proposed. The developed novel beam element named rigid-ended beam element can consider the effect of three kinds of span points within one element, which was impossible in modeling with the ordinary beam element. Calculated results for the portal frame using the rigid-ended beam element agree with the results using membrane element. And also, the proposed simplified 3- dimensional analysis method which includes two step analysis using influence coefficients shows good accuracy. Structural analysis using the rigid-ended beam element and the simplified 3-dimensional method is revealed to have good computing efficiency due to unnecessity of the elements corresponding to the brackets and simplification of 3-dimensional analysis.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.182-188
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• 1996

The hull form design is the first step of the concurrent ship design and production. At this point of view, to provide the hull form design system is very important to build the CIM system in shipbuilding. For this, we described about the functionality and the practices of the hull form design for the initial design stage based on the CIM concept. Also, we developed the hull form design system (DWHULL) using commercial 3D-CAD system. In the conclusions, we suggested the advance of the system and the direction of further development functions.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.23-30
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• 2011

This study was carried out in order to verity the usefulness of FSA(Formal Safety Assessment) methods as a tool to conduct a safety assessment of general cargo ships flying the Korean flag, and to provide useful information on 'the Safety of General Cargo Ships' for IMO committee's discussion on the matter at a future session. In the previous paper, "A Study on High-level FSA for Korean-flagged General Cargo Ships(1)", the concepts of the FSA methodology and its five steps were described and the results of Hazard Identification(Step 1) and Risk Analysis(Step 2) from the FSA study for the Korean-flagged general cargo ships were discussed. Subsequent to the Steps 1 & 2, the identification of Risk Control Options(RCOs-Step 3) for eliminating or reducing either the frequency or the severity of the risks identified and their Cost-Benefit Assessment(CBA-Step 4) were undertaken. In this paper, the results of the Steps 3 & 4 are discussed, and some recommendations are made.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.23-27
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• 2006

The training ships of maritime university in Korea are operated in the suitable schedule. However, there is no paper to grasp the education effect of the coastal navigation and ocean-going navigation terms. As the first step of these training education effects, this paper investigates the effect of training terms and provides the basic materials of the efficient training education. This paper used the 6 times test scores based on test book for 3rd officer as the assess method The results are as follows. (1)The higher credits scored in university times, the higher test scores gained in training ship. (2)After ocean-going navigation, the test score was the best.(3) The longer the training period is, the more the difference of individual capacity is.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.83-88
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• 2005

The training ships of maritime university in Korea are operated in the suitable schedule. However, there is no paper to grasp the education effect of the coastal navigation and ocean-going navigation terms. As the first step of these training education effects, this paper investigates the effect of training terms and provides the basic materials of the efficient training education. This paper used the 6 times test scores based on test book for 3/0 officer as the assess method. The results are as follows. (1)The higher credits scored in university times, the higher test scores gained in training ship. (2)After ocean-going navigation, the test score was the best(3) The longer the training period is, the more the difference of individual capacity is.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.2
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• pp.162-171
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• 2012

A method of hydrodynamic discrete sources is applied for two-dimensional modeling of stepped planing surfaces. The water surface deformations, wetted hull lengths, and pressure distribution are calculated at given hull attitude and Froude number. Pressurized air cavities that improve hydrodynamic performance can also be modeled with the current method. Presented results include validation examples, parametric calculations of a single-step hull, effect of trim tabs, and performance of an infinite series of periodic stepped surfaces. It is shown that transverse steps can lead to higher lift-drag ratio, although at reduced lift capability, in comparison with a stepless hull. Performance of a multi-step configuration is sensitive to the wave pattern between hulls, which depends on Froude number and relative hull spacing.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.48-58
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• 2020

Naval weapons systems of the Republic of Korea are acquired through the Defense Planning Management System. Recently, acquisition of some naval ships have been delayed, and the causes of the delays have been recognized as inappropriate project management at the Execution Phase. However, we argue that the delay problem in naval ships acquisition should be approached, with due regard for the entire Defense Planning Management System. That is, We should try to investigate from Planning Phase to those of Programming, Budgeting and Execution Phases. Therefore, in this study, we investigated the actual cases of the delay in naval acquisition at all phases of the Defense Planning Management System. Based on the investigation, we tried to identify the naval ship Acquisition Delay Factors and find out the Weights of those factors. As the next step, we calculated the Influence Measures on the naval missions, including the Cost of Naval Capability Gap derived from the delays in acquisition of naval ships. As a final step, we calculated the Acquisition Delay Measures based on the interrelationship between the Acquisition Delay Factors and the Influence Measures. Then we evaluated and analyzed what the results stand for. Finally, we made suggestions for future improvement. The improvement suggestions we made for preventing delay in acquisition of naval ships in this study are as follows. First, we need a shift in perception. It is necessary to measure the Acquisition Delay Factors in acquiring naval ships and manage them from the Planning Phase. Second, resolution must be concerted efforts. All relevant agencies, not just a few, should work together to resolve the problems of acquisition delay. Third, analysis must be based on the accumulation of data. This allows the elaborating of naval ship Acquisition Delay Factors and Delay Measures. If this research method is applied to other military weapons systems in the future, we may be able to not just identify the Acquisition Delay Factors in acquisition of other military weapons systems, but also pursue improvement in those cases.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.39-47
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• 1999

This paper presents the survey of technical trend in AD converters for wireless communication systems. This paper provides explanations about the performance measure of ADC in wireless communication application and the relation ship between BER versus effective resolution and sampling speed. The survey suggests that at least one step analog frequency down conversion is required for software defined radio systems due to current technological limit.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.220-226
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• 2000

In this paper, a primitive study of yacht is carried out and an attempt to design a typical yacht is pursuited. General characteristics and types of a yacht is examined and the 1st step to design process is outlined. A model ship of an environmental adaptive yacht is presented and principal dimensions of the yacht is decided.

• Journal of Ocean Engineering and Technology
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• v.28 no.1
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• pp.20-27
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• 2014

In view of the importance of material reduction and rational structural design due to the rapid increase in oil and steel prices, an optimized structural hybrid design system for the doubler plate of a ship's hull structure was developed. A direct design process by a structural designer was added to this developed optimized system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. As the first step of the doubler design system development, the design formulas used in doubler design system were introduced. Based on the introduction of influence coefficients $K_{t_c}$ $K_{t_d}$, $K_{b_d}$ and $K_{a_d}$ according to the variations in the doubler length, breadth, doubler thickness, and average corrosion thickness of the main plate, the design formulas for an equivalent plate thickness were developed, and a hybrid design system using these formulas was suggested for the slender doubler plate of a ship structure subjected to a longitudinal in-plane compression load. By using this developed design system, a more rational doubler plate design can be expected considering the efficient reinforcement of the plate members of ship structures. Additionally, a more detailed structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for the doubler plate.