교류철도급전계통에 전력품질보상장치 적용에 관한 연구

최준호,Choi, Joon-Ho 한국조명전기설비학회 2004 조명·전기설비학회논문지 Vol.18 No.6

전기 철도계통은 기존 전력계통과 달리 단상, 대용량 부하로 필연적으로 전압강하, 전압불평형 및 고조파 왜곡 등의 전력품질의 문제가 발생한다. 최근 철도계통의 전력품질문제는 철도차량 및 시스템의 제어 및 안전 때문에 중요한 화두가 되고 있다. 이는 또한 기존 전력계통의 전력품질에도 영향을 미친다 본 논문에서는 전기철도 급전시스템에 발생하는 전력품질문제의 보상에 관한 연구를 수행하고자 한다. 이를 위해 국내 교류전기철도 표준 급전방식인 AT(Auto Transformer)급전시스템, 철도급전변압기인 스콧트 변압기(Scott Transformer), AT변압기, 철도선로 및 철도 차량부하를 모델링 하였다. 과도응답은 전자기과도해석 프로그램인 PSCAD/EMTDC를 사용하여 해석 하였다. 또한 전력품질을 보상하기위한 방안으로 급전선-전차선에 설치되는 전력품질보상기(Unified Power Quality Conditioner : UPQC)를 제안하였고 이의 성능 및 유효성을 시뮬레이션을 통하여 확인하였다. The AC railway system is quite differing from the general electric power system because it is single- phase and intermittently heavy loads. Thus, inevitably power quality problems are occurred in the AC railway system, i.e. voltage regulation voltage sags, voltage imbalance, and harmonic distortion. Recently, the power quality of the AC railway system becoming a hot issue because it is affect the control and safety of high-speed traction. In addition it is also affect the power quality of the electric power system. In this paper, single-phase Unified Power Quality Conditioner(UPQS) for the AC railway system is proposed to compensate the voltage sags and harmonic distortion. The configurations and control schemes of the proposed single-phase UPQC are presented. The effectiveness of the proposed single-phase UPQC application is verified by the PSCAD/EMTDC simulation works. It can be shown that the application of UPQC in the AC railway system is very useful to compensate the voltage sags and harmonic distortion from the results of related simulation works.

전자무역에서 온라인 ADR의 유형과 활용방안에 관한 연구

최준호,Choi, Jun-Ho 한국정보기술전략혁신학회 2005 情報學硏究 Vol.8 No.1

Electronic Trade of increasing is the use of the Internet makes it possible for business to expand their markets and render services. However, it also brought up many problems caused by various issues. The problems encompass consumer protection and dispute settlement between the disputed parties. Online ADR have some advantage that are convenience, low-cost, legitimate to online users and avoids jurisdiction issues and some disadvantages that are loss of the human factor, lack of accessibility, lack of confidentiality and security and difficulty of enforcing arbitral agreements. This purpose of this paper is to reviews the types of Online ADR, as the dispute settlement way in Electronic Trade. This study points out the task that korea has to promote the Online ADR for more effective and efficient dispute settlements.

강관으로 보강된 중공 RC 기둥의 중공비에 따른 거동

최준호,윤기용,한택희,강영종,Choi. Jun-Ho,Yoon. Ki-Yong,Han. Taek-Hee,Kang. Young-Jong 한국방재학회 2007 한국방재학회논문집 Vol.7 No.3

중공 RC 기둥은 중실 RC 기둥에 비해 자중의 감소 및 재료 절감에 대한 장점을 가진다. 그러나 중공 RC 기둥은 안쪽면의 취성파괴로 인하여 낮은 연성 거동을 할 가능성이 있다. 이러한 문제점을 해결하기 위해 중공 부재 내의 콘크리트 3축 구속 상태로 존재하게 하는 강관으로 보강된 중공 RC 기둥이 개발되었으며, 본 연구에서는 강관으로 보강된 중공 RC 기둥의 중공비를 <TEX>$0.50{\sim}0.85$</TEX>까지 변화 시켜 중공비에 따른 작용하중에 대한 안전율, 연성도, 재료비, 교각 총 중량에 대한 거동 특성을 파악하였다. The hollow RC(Reinforced concrete) column has the effect of reducing weight and materials compared to solid RC column. However, the hollow RC column shows a low ductile behavior due to brittle failure of inside concrete. To overcome this problem, the internally confined hollow reinforced concrete column has been developed. In this study, the behavior of internally confined hollow RC columns were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. The hollow ratio is varied from 0.50 to 0.85.

분산전원이 연계된 배전계통의 온라인 보호협조 방안

최준호,노경수,김재철,Choi, Joon-Ho,Ro, Kyoung-Soo,Kim, Jae-Chul 한국조명전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.3

최근 경제 발전으로 인한 전력 에너지 소비 증가로 발전선비의 확충이 요구되는 상황이다. 그러나 화석연료고갈 및 지구환경문제로 대형 화력 발전설비의 확충이 어려워지고 있다. 따라서 발전부지 확보가 용이하고 환경오염의 위험이 적은 분산전원에 대한 관심이 한층 더 고조되고 있다. 그러나 이러한 분산전원이 배전계통에 연계되면 전압변동, 고조파, 보호협조, 고장전류 증가 등의 문제를 일으키므로 이에 대한 적절한 연구가 필요하다. 본 논문에서는 국내 22.9[kV] 배전계통에 다수의 분산전원이 연계되었을 경우, 각 계전기가 감지하는 고장전류의 크기와 방향성을 고려하여 고장 감지 및 고장 지점을 확인하는 방법을 제안하였다. 이를 기반으로 하여 배전계통 보호기기인 자동재폐로 차단기-구분개폐기 보호시스템이 상호협조를 이루기 위한 온라인 보호 협조방안을 제시하였다. Recently, there has been growing interest in distributed resources with high-energy efficiency due to the increasing energy consumption and environmental pollution problems. But an insertion of new distributed generation to existing power distribution systems can cause several problems such as voltage variations, harmonics, protective coordination, increasing fault current etc. In this paper, a new method of the fault location identification at the distribution system with distributed resources, which can be determined by the magnitude and direction of the fault current, is proposed. In addition, a new online protective coordination scheme of recloser-sectionalizer is proposed based on the proposed fault location identification method for distribution system with distributed resources.

고위험 증식당뇨망막병증에서 범망막광응고술과 유리체강내 베바시주맙 병합치료의 장기간 효과

최준호,이성진,최경식,Jun Ho Choi,Sung Jin Lee,Kyung Seek Choi 대한안과학회 2010 대한안과학회지 Vol.51 No.6

Purpose: To evaluate long-term effects and usefulness of combined intravitreal injection of bevacizumab and panretinal photocoagulation (PRP) in patients with high-risk proliferative diabetic retinopathy. Methods: The authors retrospectively reviewed the records of 40 patients (40 eyes) with high-risk proliferative diabetic retinopathy who had been treated with PRP alone (laser treatment group, n=20) or intravitreal bevacizumab before PRP (combined treatment group, n=20). Changes in best corrected visual acuity (BCVA), central macular thickness (CMT) and the total area of leakage from active new vessels (NVs) were compared between the groups at one, three, and six months and at one year post-treatment. Results: In the combined treatment group, CMT decreased significantly at one month (p=0.021), and the areas of active NVs decreased significantly at one month (p=0.001) and three months (p=0.014) compared to those of the laser treatment group. However, there were no differences between the two groups after three months. In the combined treatment group, elevated intraocular pressures were found in three cases after one month, and there were vitreous hemorrhages in two cases after three months. Conclusions: The combined treatment showed significant early improvements in BCVA, CMT, and NVs regression for up to three months. However, long-term follow-up and additional treatment was necessary in the patients with persistent or recurred NVs and macular edema after three months. J Korean Ophthalmol Soc 2010;51(6):842-848

Mac OS X 운영체제상의 사용자 흔적정보 수집방안 연구

최준호,이상진,Choi, Joon-Ho,Lee, Sang-Jin 한국정보처리학회 2010 정보처리학회논문지 C : 정보통신,정보보안 Vol.17 No.4

Mac OS X는 애플에서 제작한 컴퓨터 운영체제이다. 1984년도부터 MAC OS의 마지막 버전인 9를 계승하여 지금의 Mac OS X 10.6(Snow Leopard)에 이르고 있다. 전 세계 운영체제 점유율에서 애플의 Mac OS X운영체제는 10% 정도를 차지하고 있으나, 현재 디지털 포렌식 조사에 활용되고 있는 포렌식 도구들은 Mac OS X에 대한 포렌식 분석을 제대로 수행할 수 없다. Mac OS X에 대한 포렌식 조사를 하는데 있어서, 운영체제 상에서 사용자의 행위와 흔적과 관련된 정보는 중요한 디지털 증거가 될 수 있다. 본 논문에서는 Mac OS X 운영체제 상의 사용자 흔적 정보 수집에 관한 방안을 제시한다. Mac OS X is the Computer Operating System that develop in Apple Inc. Mac OS X is the successor to Mac OS 9 Version which had been Apple's primary operating system since 1984. Recently, Mac OS X 10.6 (Snow Leopard) has been manufactured and is distributed to user. Apple's Mac OS X Operating System is occupying about 10% in the world Operating System market share. But, Forensic tools that is utilized on digital forensic investigation can not forensic analysis about Mac OS X properly. To do forensic investigation about Mac OS X, information connected with user's action and trace can become important digital evidence in Operating System. This paper presents way about user trace data acquisition methodology in Mac OS X.

A Design and Performance Analysis of the Fast Scan Digital-IF FFT Receiver for Spectrum Monitoring

최준호,나선필,박철순,양종원,박영미,Choi, Jun-Ho,Nah, Sun-Phil,Park, Cheol-Sun,Yang, Jong-Won,Park, Young-Mi The Korea Institute of Military Science and Techno 2006 한국군사과학기술학회지 Vol.9 No.3

A fast scan digital-IF FFT receiver at the radio communication band is presented for spectrum monitoring applications. It is composed of three parts: RF front-end, fast LO board, and signal processing board. It has about 19GHz/s scan rate, multi frequency resolution from 10kHz to 2.5kHz, and high sensitivity of below -99dBm. The design and performance analysis of the digital-IF FFT receiver are presented.

국산 소나무껍질추출물(파인엑솔^®)을 함유한 제제의 피부흡수 평가

최준호,최민구,한완택,한선정,정석재,심창구,김대덕,Choi, Joon-Ho,Choi, Min-Koo,Han, Ohan-Taek,Han, Sung-Jeong,Chung, Suk-Jae,Shim, Chang-Koo,Kim, Dae-Duk 한국약제학회 2007 Journal of Pharmaceutical Investigation Vol.37 No.6

Pine bark extract is well-known as a very powerful antioxidant, anti-inflammatory, and antibiotic material. French maritime pine bark extract ($Pycnogenol^{(R)}$) of Horphag Research has monopolized the world market over 30 years. Korean red pine bark extract ($Pinexol^{(R)}$) was first manufactured by the patent technology of NutraPharm in Korea in 2006. Feasibility of topical gel and patch formulations of Pinexol was systematically investigated by evaluating the skin absorption of catechin as a reference compound. In vitro hairless mouse skin absorption of catechin from gel formulation was higher than that from patches. However, significant amount of catechin was also deposited inside the skin from patch formulations, which were dependent on the types of pressure sensitive adhesives. Thus, it seems to be feasible to control the topical delivery of Pinexol by using both gel and patch formulations, and be necessary to conduct further systematic investigation.

노인복지회관의 운영형태별 공간특성과 시설운영 비교분석 - 영남권 광역시 중심으로 -

최준호,서지은,이정호,Choi Jun-Ho,Seo Ji-Eun,Lee Jeong-Ho 한국주거학회 2005 한국주거학회 논문집 Vol.16 No.6

The purpose of this study was to analyze characteristics such as spatial composition, areas, location of functional unit space and comparing the type and the number of operating programs by type of managements of multipurpose senior center in Youngnam metro area. first, the consignation management facilities had functional unit space of 152 things and the direct management facilities had 115 things. When comparing average areas composition ratio, direct management is public welfare, social education, public part, medical and rehabilitation order and consignation management is public part, social education, public welfare and rest part order. Second, medical part must be located around the first floor or the elevator, because many people can frequently use this area at the same time. Third, as a result of analysis of management programs indicated that the total number of programs is as a whole 74 things a range of $min12\~max20$ in the each direct management facilities and 111 things a range of $min20\~max24$ in the each in the each consignation management facilities. This fact shows that consignation management provided many people with more various programs than direct management. Finally, the number of staff in the direct management is less than consignation management. When comparing programs per staff and space, the direct and consignation management each appeared (2.74, 0.64) and (1.35, 0.73). This fact implied that the consignation management was more specialized than direct management in the service and function.

한정된 계측 변위를 이용한 구조물 변형 형상 추정

최준호,김승준,한승룡,강영종,Choi, Junho,Kim, Seungjun,Han, Seungryong,Kang, Youngjong 대한토목학회 2013 대한토목학회논문집 Vol.33 No.4

구조물의 변형 형상은 구조해석을 위한 중요한 정보이다. 구조물 모니터링 시스템에서도 충분한 변위 계측점이 확보되어 명확하고 합리적인 구조물의 변형 형상이 도출된다면 이를 이용한 구조해석이 가능 할 것이다. 하지만 실제 구조물에서는 한정된 비용으로 인해 충분한 변위 계측점이 확보되지 못하기 때문에 합리적인 구조물 변형 형상의 도출이 어렵다. 본 연구에서는 경제적이고 합리적인 구조물 변형 형상 추정을 위해 최소의 변위 계측 데이터를 이용한 효과적인 구조물의 거동 형상 추정기법인 SFSM-LS알고리즘을 개발하였다. 본 기법은 구조물의 변형 형상을 추정하기 위해 계측 대상 구조물의 사전 유한요소해석을 통해 여러 구조 거동 형상을 기본 구조형상함수로 정의하고, 이들 함수를 추정 변위의 오차를 최소화 시키는 각 함수의 가중치로써 중첩한다. 2경간 연속교 모델의 수치해석을 통해 개발된 알고리즘을 검증하고 매개변수 연구를 수행하였다. 개발된 알고리즘의 매개 변수인 구조형상함수, 변위 계측 위치, 변위 계측 개소에 대한 형상 추정 결과의 특성을 분석하고 Polynomial, Lagrange, Spline 보간법과 형상 추정 정밀도를 비교하여 개발된 기법의 적용성을 검증하였다. 이를 통해 적은 개소의 변위 데이터로 정밀한 형상을 추정하는 결과를 도출하여 제안된 기법의 우월성을 입증하였다. The structural deformed shape is important information to structural analysis. If the sufficient measuring points are secured at the structural monitoring system, reasonable and accurate structural deformation shapes can be obtained and structural analysis is possible using this deformation. However, the accurate estimation of the global structural shapes might be difficult if sufficient measuring points are not secure under cost limitations. In this study, SFSM-LS algorithm, the economic and effective estimation method for the structural deformation shapes with limited displacement measuring points is developed and suggested. In the suggested method, the global structural deformation shape is determined by the superposition of the pre-investigated structural deformed shapes obtained by preliminary FE analyses, with their optimum weight factors which lead minimization of the estimate errors. 2-span continuous bridge model is used to verify developed algorithm and parametric studies are performed. By the parametric studies, the characteristics of the estimation results obtained by the suggested method were investigated considering essential parameters such as pre-investigated structural shapes, locations and numbers of displacement measuring points. By quantitative comparison of estimation results with the conventional methods such as polynomial, Lagrange and spline interpolation, the applicability and accuracy of the suggested method was validated.