• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.932-937
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• 2008

The transformer inrush current can cause a voltage drop by source impedance. This current can impact sensitive loads by the voltage drop. Therefore, it is necessary to take measures to limit this inrush current. This study, described in this paper, analyzes the power quality affected by transformer inrush current using the X power system in Korea. The Electromagnetic Transients Program(EMTP) is used to analyze the transient phenomenon. We discuss a method to model the hysteresis curve of the transformer in EMTP. We carried out various simulations to analyze the power quality during transformer energization. The analysis results of voltage drop by the inrush current occurrence when certain requirements are met are presented.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.2
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• pp.200-208
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• 1997

The WHO separates odontogenic carcinomas into three groups : malignant ameloblastoma, primary intraosseous carcinoma(PIOC), and carcinomas arising from odontogenic epithelium including those arising from odontogenic cysts. In WHO criteria, primary intraosseous carcinoma is defined as a squamous cell carcinoma arising within the jaw, having no connection with the oral mucosa, and no developing from residues of odontogenic epithelium. This is a case of 52-year old man who had prolonged jaw pain and final diagnosis was primary intraosseous carcinoma(PIOC) on mandible. We obtained successful result after composite resection combined with hemimandibulectomy, RND, following reconstruction with latissmus dorsi myocutaneous flap, and postoperative radiation therapy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.755-761
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• 2009

The major advantage of transparent materials over traditional materials in noise barriers is aesthetics. The transparent panel materials such as clear plastic or glass are an ideal way of reducing or virtually eliminating the visual impact of a noise barrier. With the use of transparent materials, the drivers' view of the roadside and the sunlight penetration to the highway would not be blocked. With the use of transparent materials, the highway and barrier appear less imposing. Korean Industrial Standards for soundproof panels have been established. But, transparent soundproof panels are not included in this standards. And, some specifications provide only a few basic characteristics for transparent soundproof panels. To develop guidelines on quality criteria for transparent soundproof panel, their mechanical properties such as wind load resistance, safety under impact, and abrasion resistance were experimentally investigated.

• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.58-61
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• 2005

분산전원의 등장은 전체 전력계통의 안정도 및 전력품질 등에 영향을 미친다. 이러한 분산전원에 의한 영향은 고장, 전력 공급의 높은 신뢰성, 전압 새그완화 등에 의한 긍정적인 영 과 보호계전기의 정정 변화 및 그에 따른 오동작과 같은 신뢰성 감소의 부정적인 영향으로 구분하여 볼 수 있다. 그러나 분산전원이 존재하는 전력계통의 해석은 다앙한 분산전원의 종류와 특성에 따른 변화에 의해 더욱 어려워진다. 본 논문에서는 동기발전기 모델을 사 하여 분산전원을 모델링하였으며, 전력계통 과도현상 해석 프로그램인 EMTP를 사용하여 전원이 존재하는 배전계통을 모의하였다. 또한, 분산전원의 위치, 용량 등의 차이에 따라 계통에 미치는 영향에 대해 분석하였다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2808-2813
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• 2011

According to opening the domestic existing lines and High-Speed Lines(HSL) depending on each section and phase-in, there were constructed in railway over state-of-the-art radio communication networks. Therefore, there have been 3 wireless communication networks in domestic railways in accordance with running sections as like VHF, TRS-ASTRO and TRS-TETRA. For instance, the VHF networks were constructed in exsiting lines and TRS-ASTRO were Kyungbu HSL phase-1 except Seoul-Kwangmyung section, downtown in Daejeon City and that of Daegu City. And it was constructed in DongDaegu-Busan section of Kyungbu HSL phase-2, Osong-Kwangju section of Honam HSL phase-1 and would be done in Kwangju-Mokpo of Hanam HSL phase-2 and Soosu-Pyungtaek of Metropolitan Area Line by TRS-TETRA. In this paper, we described some important problems of radio communication management and investigated current state of radio communication for railways. Moreover, we presented the necessity of integrated radio networks for domestic railways.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1066-1076
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• 2011

The subsystems of HSR train control system in each country has developed and operated till early 2000, however 2001/16/EC ERTMS is issued for inter-operability among European train control systems in 2001. So it is trend that ERTMS/ETCS has been applied to not only low-speed train system but high-speed train system over 300km/h in many countries of Europe. According to the government policies of the Honam HSR, metropolitan HSR and test lines, incoming on-board signal control system has been required caused by speed limit to 160km/h on the ground signal system. As ETCS-Level 1 system has applied in our railways from 2003, so our train control system has depended on foreign technologies. In this paper, we analyzed to localize train control system for being ready to protect foreign policies and obtaining core technologies of HSR train control system for instance ETCS-Level2.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2373-2382
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• 2011

As the government set the direction for Green Growth recently, so local government struggles to obtain carbon emissions trading. In the center of this global environment atmosphere, the quantitative targets would be suggested by some developed countries. In case of a international green movement like this, it would have been being induced from by crystallizing of economic and environmental regulations and legal policies that not only a meter-rate system of carbon emissions but also application for regenerate energy. In this paper, we researched cultivating of energy storage system(ESS) to conjugate regenerative energy of train, an energy efficiency and cultivating cost etc. In conclusion, we would acknowledge a difficulty in cultivating ESS only for cost reduction of energy consumption, so governmental policies for green growth should be thoughtfully examined.

• Journal of the Korean Society of Systems Engineering
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• v.8 no.1
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• pp.1-7
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• 2012

This research aims to propose a model to estimate the appropriate SE Cost rate to the total project cost when systems engineering applied to light rail transit project. In this research an investment cost estimation model is proposed with reference to COSYSMO (Constructive System Engineering Cost Model). This model includes four input factors such as requirement numbers, interface numbers, algorithm numbers, and scenario numbers. When 2600 requirement numbers are considered on a proposal document with 350 pages in a light rail transit specification of 500 billion~trillion won scale, COSYSMO demo version estimates 42.5 billion won of SE cost (about 5% of total project cost or about 10% of E&M cost).

• Computational Structural Engineering
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• v.6 no.2
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• pp.13-16
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• 1993

본 고에서는 철골 구조물에 있어서 일어나고 있는 좌굴에 대해, 현재 외국에서 진행중인 연구의 일부를 소개하였다. 이들의 기본 개념은 좌굴이 일어날 수 있는 압축부재에 있어서 최대내력, 즉 좌굴이 일어나기 이전에 부재를 압축에 대해 항복시킴으로써, 좌굴을 방지하려는 연구의 일종으로서, 부재의 강도면에 있어서는 큰 손실이 뒤따르게 된다. 하지만, 트러스 등의 구조물에 있어서 압축보다 인장에 대해서 사전에 항복하도록 설계(선인장 항복설계)가 이루어진 경우일지라도, 인장항복만으로 붕괴기구가 형성된다. 또한, 일반적으로 트러스를 제작함에 있어서 시공상의 오차가 발생할 가능성이 상존하고 있으며, 부정확하게 시공된 구조물에 있어서는 설계시 상정된 파괴기구와는 다른 형태의 파괴기구가 형성될 가능성이 있다. 따라서, 안정항복하여 큰 소성변형이 필요한 경우에는 상기의 방법이 유효하다고 사료된다. 한편 본 고에서 예로 다루고 있는 2중 강관구조에 있어서는, 외관과 내관의 단면적비가 약 1:1.5 정도이며, 보강재로 사용되는 내관을 아무리 저급의 제품을 사용한다해도 불경제적이 될 가능성이 크다. 따라서 금후, 내관의 단면 결정을 위한 많은 연구가 이루어져야 한다고 생각한다.

• Proceedings of the CALSEC Conference
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• 1997.11a
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• pp.287-302
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• 1997

$\square$ 연구 프로세스 $\bigcirc$ 연구 프로세스 무기(장비)의 개발 프로세스의 시작 점 ☆ 무기(장비)개발의 지연, 비용 증가, 개발 실패의 중요한 발생 요인 내포 $\bigcirc$ 연구 프로세스의 전통적 관점과 현재의 프로세스적 관점 ☆ 전통적 사고： 전문 연구자의 과도한 통제는 긴장 유발 가능으로 연구프로세스를 ‘블랙 박스’로 인식 ☆ 현재： 연구의 가시성과 모니터링 가능 $\bigcirc$ 연구 프로세스의 개선 추진 요인 ☆ 컴퓨터를 이용한 실험실 모델/분석, 컴퓨터 기반의 현장 시험과 결과의 커뮤니케이션, 추적 시스템/프로젝트 관리 시스템, 프로젝트 상에서 정보의 광범위한 유포 $\bigcirc$ 체계개념연구 프로세스의 프로세스 개선전략 ☆ 연구 프로세스 개선 추진요인을 통해, 연구 관련 정보를 관리 사업을 과속화/지연, 자원활용 극대화, 전망이 어두운 사업을 판별 조기 취소 ☆ 정보기술과 추진요인이 지닌 능력의 결합으로 개선 유도 ☆ 유의점： 연구에 종사하는 과학자, 전문 연구자의 전통적 독립성, 자율성과 신중한 균형 유지(중략)