• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.106-111
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• 2011

The use of thin plate increases due to the need for light weight in large ship. Thin plate is easily distorted and has residual stress by welding heat. Therefore, the thin plates should be carefully joined to minimize the welding deformation. In this study, the welding deformation of PCTC which use a thin plate is investigated by using equivalent load method. The analysis model of 10, 11, 12, upper and garage deck is composed of thin plate of 6mm which is susceptible to welding heat. For two different welding sequences, the welding deformation is calculated and its trend is investigated. The influence of gravity on welding deformation is studied.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.424-428
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• 2008

On processing of the shipbuilding, Various steel plates are used as the important material in many fields including the shell plate, a structure, etc. Therefore, the proper steel plate management system like a warehousing, pile, delivery is very important. Presently Operators manage the steel plate by using the software program, but they manage many parts manually, so many problems are generated on the steel plate check, management, and operator safety. In order to solve this problem, we developed Auto Steel-Plate Piling System. Also this system automatically manages and traces the steel-plate from warehousing to delivery.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.331-333
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• 2001

The flooded type battery is used for solar lighting system. Because the characteristic of flooded type battery is the short life time, the maintenance cost is high. So the using floe fed type battery in this system is inappropriate. The valve regulated lead acid batter(VRLA) is the maintenance free and cycle service purpose. This paper presents the development of control system and monitoring system to applied VRLA battery for maintenance free and long life time in system.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.767-770
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• 2011

선박은 항해시에 여러 가지 정보 시스템을 필요로 한다. 이러한 시스템들은 상호 연관성 없이 떨어져서 개별적으로 운용되고 있으며 시스템 확장을 고려하지 않고 구축되었기 때문에 선박 내 다른 장소나 육상에서 운항관련 정보에 접근하기가 어렵다. 본 논문에서는 이러한 문제를 해결하고자 선박 항해에 필요한 여러 시스템을 통합해서 모니터링하는 웹기반 시스템인 nDisplay를 개발하였다.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.6
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• pp.390-398
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• 2013

In this paper, an experimental study on sloshing problems in an independent B-type tank of STX Offshore and Shipbuilding Co. is described. Recently STX Offshore and Shipbuilding Co. introduced a new design of an independent B-type tank in order to reduce sloshing impact loads on LNG CCS. This tank has many internal members, so that sloshing flow and the resultant hydrodynamic loads are very different from those in typical membrane tanks. In this study, a series of sloshing experiment have been carried out for 1/50 scale model, and the main characteristics of sloshing load on the independent tank are observed. The properly scaled internal members such as swash bulkhead, center bulkhead and stringers have been installed in the test tank model, but sloshing pressures are measured on the tank walls only. The forced excitation signals have been generated by using the predicted ship motion in irregular sea states. The characteristics of sloshing loads on this tank have been observed in different filling levels with various heading angles, and sea states. In this paper, some key findings from the model tests are discussed.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.1
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• pp.59-68
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• 2013

Nowadays, optimum structural design techniques based on CSR have been developed and applied to the preliminary design stage focused on minimum weight and minimum construction cost of ship structure. Optimum structural design algorithm developed before could minimize weight and cost on fixed compartment arrangement. However, to develop more efficient design technique, a designer needs to combine optimized compartment arrangement with optimized ship structural design because compartment arrangement has a large effect on structural design according to the change of still water bending moment as a consequence of compartment arrangement change. In this study, automated algorithm for compartment arrangement of an oil tanker is developed to apply preliminary structural design. The usefulness of developed algorithm is verified with Aframax oil tanker constructed by STX shipbuilding Co.Ltd..

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.386-391
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• 2005

This study was done to produce a mutated protein inactivated cytotoxicity of Shigatoxin 2e (Stx2e) of E.coli O139 isolates by deletional mutagenesis of Stx2e A subunit gene encoding active-site cleft of enzymatic domain in ST2e holotoxin. Cytotoxicity of the toxoid expressed from the mutant Stx2e gene was compared with wild type Stx2e for development of vaccine candidate. A recombinant plasmid pED18 containing Stx2e gene ot E.coli O139 isolates was used to generate mutation plasmid. Deletion mutagenesis was conducted for Stx2e A subunit gene encoding enzymatically active domain by polymerase chain reaction (PCR) using ot designed primer to induce deletional mutation. DNA sequence analysis was confirmed that the pentamer (Typ 202- Ser 206) that lies within the proposed active-site cleft in the second region was completely deleted. A DNA fragment of 1.1 kb that encode the new mutant Stx2eA gene was inserted into plasmid pRSET vector digested with EcoRV-Hind III and named pEDSET The PEDSET was transformed in E. coli for expression of mutant protein and the protein was confirmed by SDS-PACE and Western-blotting. The protein expressed by the mutant was tested to confirm the reduction of cytotoxic activities on Vero cell using microcytotoxicity assay compared with wild type Stx2e, the cytotoxicity of deletional mutant protein was at least reduced by 3,000-fold on Vero cell.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.309-315
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• 2019

To enumerate Staphylococcus aureus in food, Baird-Parker Agar (BPA) is usually used in the conventional method, However it requires time and space for the preparation and plating, and incubation. Thus, use of the $3M^{TM}$ $Petrifilm^{TM}$ Staph Express Count Plate (STX Petrifilm) might be appropriate to solve these challenging problems. The purpose of this study was to compare the efficiency of STX Petrifilm with BPA for enumeration of S. aureus in various foods. A mixture of S. aureus strains ATCC29213, ATCC25923, and ATCC13565 was inoculated on marinated pork chop, beef (chuck tender), dried filefish, semi-dried squid, rice cake, and Japchae (stir-fried glass noodles) at 2, 3, 5, and 7 Log CFU/g. S. aureus cell counts were enumerated by spread-plating on STX Petrifilm and BPA after 0 and 24 hours at $4^{\circ}C$ (marinated pork chop, beef, semi-dried squid, and stir-fried glass noodles) and $25^{\circ}C$ (dried filefish and rice cake). Recovery of STX Petrifilm for S. aureus from various food samples was compared with BPA, and the results showed that there were no significant differences between two selective media in all cases. The results indicated that STX Petrifilm had enough efficiency to recover S. aureus from various foods as well as saving time and space.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.106-111
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• 2006

The steel outfitting structures installed in engine room are vibrated by an excitation of the engine and the propeller. Vibration problems such as cracks and fitting breakages are mainly induced at the near range of the resonance. The excitation frequency estimation is possible by engines and propeller specifications, but the natural frequency of a steel outfitting structure is not easily estimated due to the complication and variety of the designed shape. This paper represents natural frequency data of simple steel outfitting structures. As a vibration analysis tool, MSC/NASTRAN was used to calculate natural frequencies. Natural frequencies were compared in case of the shape and boundary condition changes of simple models, and anti-vibration models of the steel outfitting structures were presented on the basis of results.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.81-84
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• 2013

일반적인 Bulk carrier는 Single deck, Double bottom, Hopper side tank, Top side tank와 함께 Single side skin 또는 Double side skin으로 구성되어 Single hull bulk carrier 또는 Double hull bulk carrier라 불린다. 본 논문의 연구선박인 Double hull bulk carrier는 CSR에서 규정짓고 있는 Double hull bulk carrier의 특징 중 Hopper side tank가 없기에 일반적인 Double hull bulk carrier와는 다른 구조를 가진다. 구조적 특징으로는 Inner bottom과 Inner hull 연결부위에 응력 집중 발생, Side shell의 Shear에 대해 구조적 안전성, Double hull에 대한 CSR for bulk carrier의 Rule적용 여부에 대한 판단 등이 있다. 따라서 본 연구에서는 Double hull bulk carrier의 구조적 특징과 구조해석을 통한 응력 집중 부위의 평가 및 Fatigue analysis을 통한 피로수명을 계산하여 이를 통해 구조의 안전성을 살펴보고자 한다.