• 에너지공학
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• 제11권3호
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• pp.194-202
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• 2002

본 논문은 객체지향 프로그램(OOP)을 사용하여 광양제철소 전력계통의 과도안정도를 모의한다. OOP는 절차식 프로그램보다 유연한 방법으로서 동적인 시스템의 모의에 여러 가지 장점이 있다. 시스템의 변화가 있으면 프로그램 전체을 수정하는 대신 필요한 부분만을 수정하면 되므로, 프로그램의 유지 및 보수가 매우 용이하다. 본 논문에서는 OOP를 이용하여 동적인 시스템의 해석을 위한 유연한 방법을 제시하였다. 시스템을 직접 사용자가 그려서 전력조류계산과 동적 안정도를 모의할 수 있는 사용자 인터페이스를 구현하여 17기의 동기발전기와 25기의 동기전동기로 구성되는 광양제철소 전력계통의 동적 안정도 해석에 적용하였다.

• 한국가스학회지
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• 제11권1호
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• pp.18-22
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• 2007

전력선에 지락고장이 발생할 경우 대지로 유입된 고장전류에 의하여 인접한 배관에 아크 용융이 발생하면 가스폭발이나 기름유출과 같은 대형사고를 발생시킬 수 있으며, 배관의 유지 및 보수를 담당하는 작업자의 안전에도 위험을 초래할 수 있다. 본 논문에서는 대지를 통한 철탑과 배관 사이의 아크 발생에 대하여 알아보고, 국내외에서 사용되고 있는 철탑 인근에 매설된 배관의 이격거리 기준을 조사하였다.

• 대한기계학회논문집A
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• 제28권8호
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• pp.1221-1228
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• 2004

The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Table liner is one of grinding elements of vertical roller mill and is subjected to the cyclic bending stress by rollers load and the centrifugal force by rotation of table. It demands $4{\times}10^7$ cycle but has $4{\times}10^6{\sim}8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller. The repair expense for it amounts to $30\%$ of total maintenance of vertical roller mill. Therefore, this study shows the fracture mechanism of table liner for vertical roller mill using HDM and fatigue analysis and makes the estimation for safety of vertical roller mill.

• 한국컴퓨터정보학회논문지
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• 제19권5호
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• pp.53-60
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• 2014

최근 IT 기술의 급속한 발전으로 시설물의 설비진단과 관련된 융합 기술의 발전이 가속화되어 가고 있으며, 설계에서 유지, 보수 단계에 이르는 모든 관련 정보를 효율적으로 처리하고 관리할 수 있는 기법에 대한 연구가 요구되고 있다. 본 논문에서는 IT융합기술을 기반으로 설비 진단 및 시설물에 대한 복합정보를 효율적으로 처리하는 처리기법을 제안하고 실시간 복합정보 관리시스템을 설계하였다. 제안된 시스템의 성능을 평가하기 위해 특정 시설물을 대상으로 실시간 관리시스템을 설계하였으며, 결과를 분석하여 제안된 기법의 성능이 우수함을 입증하였다.

• 방송공학회논문지
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• 제27권2호
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• pp.240-243
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• 2022

프로그램 결함에 대한 위치 추적은 소프트웨어 유지 및 보수를 위해 필수적인 요소이다. 대부분은 버그리포트가 제출되었을 때, 결함 추적이 개발자들의 수작업으로 이루어지기 때문에 비용 소모가 많은 작업에 속한다. 현재까지 많은 연구자가 해당 작업을 자동화시키기 위하여 노력해 왔지만 보고된 결과에 따르면, 현업에서 사용되기에 아직도 부족한 성능을 보이는 추세이다. 이에, 본 연구에서는 많은 양의 버그 리포트 데이터와 관련 최신 연구들을 분석하여, 기존 연구들이 하나의 전처리 방법을 모든 버그 리포트에 일괄적으로 적용하고, 이런 방법은 위치 추적에 악영향을 준다는 것을 파악하였다. 본 논문에서는 이와 같은 문제점을 해결하기 위해 선택적인 전-후처리 방법론을 제안한다.

• 한국안전학회지
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• 제32권6호
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• pp.40-45
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• 2017

Chemical accidents generated during maintenance, repair, and normal operation, such as dispersion, fire, and explosions, can cause massive losses like a 2012 hydro fluorine leak in Gumi, South Korea. Since this accident, many researches have studied physical mitigation systems. However, due to many difficulties including potential costs and lack time, it is really hard for many companies to install mitigation systems without prior knowledge. Thus, the efficacy of mitigation system should be evaluated. This study assesses a dike design considering the fluid velocity at an open hole when a leakage accident occurs. It is assumed that leakage materials follow a free fall motion. Throughout case studies, a current KOSHA guide for a dike design was evaluated and new guidelines handling various conditions were proposed.

• 대한조선학회논문집
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• 제46권2호
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• pp.203-217
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• 2009

The researches on the development of composite material propeller with outstanding damping effects have been actively attempted for the reduction of radiation noise of underwater vehicle propeller. Composite material suitable for the flexible propeller has the following advantages, such as high specific strength and specific stiffness, low thermal expansion coefficient, high resistance against environmental deterioration, low possibility of corrosion due to cavitation, nonoccurrence of rapid fracture due to fatigue, easy molding of complicated shape, easy repair maintenance and low production costs, etc. For the confirmation of optimal fiber array structures of composite material for the production of the flexible propeller blades, in this study, mechanical characteristics of its specimens according to materials were obtained and structural characteristics of propeller blade were also examined according to materials and stacking fiber arrays.

• Journal of Electrical Engineering and Technology
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• 제7권5호
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• pp.772-777
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• 2012

Accidents caused by water absorption in water-cooled generator stator windings often occur all over the world. The absorption into the insulator of the coolant, which is used to cool down the heat generated by stator windings during operation, leads to the deterioration of dielectric strength, and insulation breakdown. An insulation breakdown may cause not only an enormous economic loss but also a very serious grid accident that would compromise stable supply of electric power. More than 50 % of domestic generators have been in operation for more than 15 years, and water absorption tests performed on 50 water-cooled generator stator windings during a five-year planned preventive maintenance period beginning in 2006 identified water absorption problems in 10 of them, all of which required repair. Because the existing water absorption test detects this problem by utilizing stochastic methods after measuring the capacitances at the final positions of insulation breakdown, its accuracy is limited. This study demonstrates that water absorption can be more accurately diagnosed by utilizing method along with a more precise one.

• 한국컴퓨터정보학회논문지
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• 제21권10호
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• pp.115-123
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• 2016

In this paper, we propose a Model Driven Development using UML(Unified Modeling Language) in an efficient Combat System Software development methods. UML is managed by the OMG (Object Management Group) as a Unified Modeling Language. Recently, In developing the software for the system, development time is contrary to a short, while it must meet a number of requirements of our customers. If you develop a non-efficient software early, the structure of the software become more complex in proportion to the number of requirements. As a result, a serious problem in the system, such as an increase in defective products due to the lowering of the reliability and communication problems between the developer has occurred. To overcome those problems, the aim of this paper is to develop a reusable high efficient Combat System Software by applying Model-Centric Development (Not Code-Centric Development). If Combat System Software development method using the UML proposed in this paper is used, easy communication among developers can help reduce the serious errors in systems. Also, it has the advantage that the future needs of software maintenance/repair become easy by using high readability object Model.

• 농촌계획
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• 제22권2호
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• pp.19-29
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• 2016

Disasters that occur most frequently in rural areas are drought, flood, damages from wind and cold weather. Among these, damages from storm and flood and drought are the main disasters and recently, these are occurring on a large scale due to unusual weather conditions. Under such circumstances, projects and researches on disasters in rural areas are under way but they are mostly targeting one area or making approaches focusing on repair facilities, maintenance project of facilities in small streams, and disaster management, so there have not been enough studies on the current status of overall damaged facilities in the rural areas. Against this backdrop, through the analysis of the current status of damaged facilities due to storm and flood in rural areas, this study aims to provide base data for policies needed for disaster recovery planning and maintenance work of rural areas. For the analysis of damaged facilities due to storm and flood in rural areas, using the annual report on disasters issued by Ministry of Public Safety and Security and based on the occurrence rate of estimated damage in each city and district for the past 10 years(2004~2013), 8 areas with the highest number of occurrence and cost of damage were found from each province and target areas were selected. Then, regarding the selected target areas, the General Plan for Reducing Damages from Storm and Flood, which is the report on top-level plan for preventing disasters, was secured and the current status of damaged facilities were analyzed. After organizing the analysis of current status, the tendency of damaged facilities due to storm and flood in rural areas, the items of damaged facilities depending on the types of storm and flood damages, and risk factors were suggested. Based on this result, in order to generalize the results of follow-up researches, it is thought that disaster recovery planning and establishing the system of remodeling items necessary for maintenance work would be possible by analyzing damage investigation items recorded in additional researches on rural areas, researches on natural disasters, and recovery plan instructions and by conducting on-site investigation on the damaged villages from storm and flood in rural areas.