• 정보보호학회논문지
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• 제28권6호
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• pp.1439-1448
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• 2018

MS 워드를 포함한 다양한 전자 문서파일은 계약서 위조, 영업기밀 유출 등의 각종 법적 분쟁에서 주요 쟁점이 되고 있다. MS 워드 2007 이후부터 사용되는 OOXML(Office Open XML) 포맷의 파일 내부 메타데이터에는 고유의 RSID(Revision Identifier)가 저장되어 있다. RSID는 문서의 내용을 생성/수정/삭제 후 저장할 때마다 해당 단어, 문장, 또는 문단에 부여되는 고유한 값으로, 내용 추가/수정/삭제 이력, 작성 순서, 사용된 문서 어플리케이션 등의 문서 이력을 추정할 수 있다. 본 논문에서는 사용자의 행위에 따른 RSID의 변경 사항으로 원본과 사본 구별, 문서파일 유출 행위 등을 조사하는 방법론을 제시한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.262-263
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• 2008

LCD 디바이스는 그 동작원리와 전기-광학적 특성에 의해 CRT와는 다른 감마곡선 특성을 갖고 있다. 대부분의 LCD디스플레이 디바이스들의 감마곡선은 CRT와는 달리 일관성을 갖지 않을 뿐 더러 흑백계조입력을 기준으로 하는 감마보정을 위해 RED, GREEN, BLUE 입력값을 세부적으로 조정할 때 각 계조입력에 대한 상관색온도가 일정한 값을 갖지 않아 LCD의 특성에 대한 모델링과 보정에 어려움이 있다. 또한, 애플사의 맥머신 그리고 실리콘 그래픽스사의 시스템과 같이 소정의 감마값을 전제로 해당 시스템의 내부참조테이블(internal look-up table)이 설계되어 각기 다른 시스템감마를 가지는 장치들에 의해 인코딩되어진 영상출력신호의 경우, 동일한 시스템을 갖추거나 시스템감마에 대한 역감마특성을 가진 디스플레이장치가 아닌 환경에서는 원본영상에 대한 왜곡은 더욱 커질 수 있다. 특히, 낮은 흑백계조입력에서의 색온도의 경우, 파장에 따라 서로 다른 감쇄성능을 가진 일반적인 컬러필터의 특성에 의한 누설광(light leakage)에 의해 결정되며, 이로 인해 색온도가 특정한 객을 띄는 현상이 발생한다. 본 논문에서는 LCD디스플레이의 감마곡선을 여러 가지 시스템감마에 대응할 수 있는 감마곡선예 일치시키고, 계조선형성을 동시에 개선하기 위하여 입력 디지털값과 삼자극치간 관계를 나타내는 여러 가지 컬러모델링 방법 중에서 PLCC(Piecewise Linear Interpolation assuming Constant Chromaticity coordinates)모델을 적용하고, 목표로 하는 감마곡선과 색온도를 만족하기 위한 새로운 입력값을 구한 후 이를 컬러참조테이블(color look-up table)예 적용하는 방법과 저계조에서의 색온도를 목표색온도에 근접시키는 방법을 제안한다.

• 한국임상수의학회지
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• 제29권1호
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• pp.87-92
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• 2012

A six months old, male Shih Tzu dog was referred to the Veterinary Medical Teaching Hospital at Kangwon National University, for lethargy, respiratory embarrassment. Survey radiography revealed enlarged cardiac silhouette due to displacement of gas-filled intestine in the pericardium. Although there were no specific clinical signs, this case was diagnosed as peritoneopericardial diaphragmatic hernia (PPDH) based on the results of positive contrast radiography and thoracic ultrasonograpic findings. In addition, the thickened gall bladder wall observed in ultrasonography, increase of alkaline phosphatase and neutrophils indicated cholecystitis. Two hepatic lobes and gall bladder were severely necrotized and adhere to the diaphragm. Direct reduction of the herniated organs might cause hepatic hemorrhage and bile juice leakage which may induce very poor prognosis. To solve the problems, the adhered organs were dissected with part of diaphragm, and lobectomy with cholecystectomy was performed for prevention of some possible complications including peritonitis. This is case report describing resection of part of diaphragm adhered to herniated organ reduce the risk of possible hepatic hemorrhage during surgical correction of PPDH followed bycholecystectomy and lobectomy.

• 한국안전학회지
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• 제29권6호
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• pp.68-75
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• 2014

It is very important to classify explosion hazardous area (EHA) suitably and to use proper explosion-proof electric installations for facilities using flammable gases and liquids. In the past, various examples in the Notification of Ministry of Employment and Labor were referred to in classifying EHA. But, at present, many companies use the hypothetical volume in Korean Standards (KS). This study reviews the validity of EHA classification based on the hypothetical volume by comparing the calculated radii of EHA with those obtained by a consequence analysis program called PHAST and a mathematical approach in British Standards (BS). The radii of EHA by the hypothetical volume were found to be slightly larger than those by the other two methods. This was attributed to rather conservative uses of a safety factor(k) and a correction factor(f) for availability of ventilation in calculating the hypothetical volume. Since the differences are not so conspicuous, however, it is concluded that the hypothetical volume in KS is a valid means for the classification of EHA. This study also presents a table of the radii of EHA for easy reference by small-scale companies using city gas, C3-LPG and flammable liquid(toluene), respectively. The table consists of 25 leakage scenarios corresponding to combinations of 5 pipe(nozzle) sizes and 5 operating conditions for each flammable gas and liquid.

• 한국임상수의학회지
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• 제32권1호
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• pp.49-55
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• 2015

This study was retrospectively investigated the clinical features, diagnostic imaging, treatment, and prognosis of foreign bodies according to alimentary site and type of foreign body, in 143 dogs. Among 28 breeds, Maltese, Shih Tzu, and terriers including the Yorkshire terrier were presented with high prevalence. Bone was the most commonly identified (33%) foreign body regardless of alimentary site. Approximately 76% of foreign bodies were in the stomach and small intestine. All esophageal foreign bodies were diagnosed on survey radiography, with the most common location being the caudal thoracic esophageal segment. Further diagnostic examinations including ultrasonography or contrast studies were additionally performed to detect radiolucent foreign bodies and perforation or leakage in the stomach and intestine. However, most seeds could be identified based on the characteristic features such as hyperdense thin double lines and inner gas on survey radiography. In conclusion, complications such as peritonitis and intestinal perforation were mainly observed in cases with seeds and linear foreign bodies. Especially, fabric foreign bodies could be induce peritonitis and re-perforation with high prevalence after surgical correction.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.644-652
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• 2016

This paper presents an improved single-stage ac-dc LED-drive flyback converter using the transformer-coupled lossless (TCL) snubber. The proposed converter is derived from the integration of a full-bridge diode rectifier and a conventional flyback converter with a simple TCL snubber. The TCL snubber circuit is composed of only two diodes, a capacitor, and a transformer-coupled auxiliary winding. The TCL snubber limits the surge voltage of the switch and regenerates the energy stored in the leakage inductance of the transformer. Also, the switch of the proposed converter is turned on at a minimum voltage using a formed resonant circuit. Thus, the proposed converter achieves high efficiency. The proposed converter utilizes only one general power factor correction (PFC) control IC as its controller and performs both PFC and output power regulation, simultaneously. Therefore, the proposed converter provides a simple structure and an economic implementation and achieves a high power factor without the need for any separate PFC circuit. In this paper, the operational principle of the proposed converter is explained in detail and the design guideline of the proposed converter is briefly shown. Experimental results for a 40-W prototype are shown to validate the performance of the proposed converter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.233-236
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• 2002

The solution for PFC(Power Factor Correction), as a regulation in energy Policy, is becoming a hot Issue in every country because of the shortage of electrical energy. Therefore, a new improved idea for PFC problem has been introduced in this study. A lot of merits, effective cost by simple circuit, reduced PCB size, lighter than reactor in the view of weight, lower level of screen noise by leakage inductance in CTV applications, have been stated by comparing to the earlier method of using a Reactor. All test results in this statement were done by using a power device of STR-G9600 series based on the real load condition of color television. furthermore, the study shows that the test results also meets the IEC-1000-3-2 class D, which regulates the PFC when input power of a set is more than 75watts. More improved PFC in other applications hopes to be implemented by using the proposed method.

• 전력전자학회논문지
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• 제9권1호
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• pp.65-72
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• 2004

본 논문에서는 새로운 형태의 부스트 입력방식의 공진형 AC/DC 컨버터를 제안하였다. 제안된 컨버터는 교류 전원측의 역률개선과 컨버터 출력전압을 동시에 제어하는 단일단 역률 개선방식으로써 전류 연속모드 펄스폭 변조방식을 통해 99%의 고역률을 얻을 수 있으며, 변압기 누설 인덕턴스와 공진 커패시터간의 공진을 이용하여 영전압스위칭을 구현할 수 있기 때문에 스위칭 손실을 줄일 수 있다. 제안된 컨버터의 이론적 고찰을 위해 각 모드별 전류로를 통해 동작을 설명하였으며, 정상상태에서의 DC해석을 이용한 공진특성 분석을 하였다. 본 논문에서는 제안된 컨버터의 유효성 확인을 위해 입력 $120[V_AC],\; 출력\; 48[V_DC],\; 4[A]\; 200[W]$급 프로토타입 컨버터를 제작하였으며 실험을 통해 얻은 결과를 제시함으로써 이를 증명하였다.

• 대한안전경영과학회지
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• 제19권2호
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• pp.31-39
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• 2017

Classify of explosion hazardous areas must be made at the site where flammable materials are used. This reason is that it is necessary to manage ignition sources in of explosion hazardous areas in order to reduce the risk of explosion. If such an explosion hazard area is widened, it becomes difficult to increase the number of ignition sources to be managed. The method using the virtual volume currently used is much wider than the result using CFD(Computational Fluid Dynamics). Therefore, we tried to improve the current method to compare with the new method using leakage characteristics. The result is a realistic explosion hazard if the light gas is calibrated to the mass and the heavy gas is calibrated to the lower explosion limit. However, it is considered that the safety factors should be taken into account in the calculated correction formula because such a problem should be considered as a buffer for safety.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1209-1217
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• 2019

Due to the limitation of the computers, the conventional homogenization method is based on many assumptions and approximations, and some tough problems such as energy spectrum and boundary condition are faced. To deal with those problems, the Monte Carlo global homogenization is adopted. The Reactor Monte Carlo code RMC is used to study the global homogenization method, and the one-step global homogenization method is proposed. The superimposed mesh geometry is also used to divide the physical models, leading to better geometric flexibility. A set of multigroup homogenization cross sections is online generated for each mesh under the real neutron energy spectrum and boundary condition, the cross sections are adjusted by the superhomogenization method, and no leakage correction is required. During the process of superhomogenization, the author-developed reactor core program NLSP3 is used for global calculation, so the global flux distribution and equivalent homogenization cross sections could be solved simultaneously. Meanwhile, the calculated homogenization cross section could accurately reconstruct the non-homogenization flux distribution and could also be used for fine calculation. This one-step global homogenization method was tested by a PWR assembly and a small reactor model, and the results show the validity.