1996년도 제35차 대한소화기학회 추계학술대회 / 일반연제 : 간 ; 알파 인터페론 치료로 음전후 재발된 만성 B 형간염례들에서 치료전과 재발후의 바이러스 유전자 염기서열의 비교

유병철,문철,박중원,김재규,박실무 ( B . C . Yoo,C . Moon,C . W . Park,J . K . Kim,S . M . Park ) 대한소화기학회 1996 대한소화기학회지 Vol.28 No.1

채널별 음장분포 분석을 통한 진단용 초음파 어레이 프로브의 평가방법에 관한 연구

유병철,최흥호,노시철,민해기,권장우,Yoo, B.C.,Choi, H.H.,Noh, S.C.,Min, H.K.,Kwon, J.W. 대한의용생체공학회 2006 의공학회지 Vol.27 No.5

The acoustic field analysis method is the superior calibration method for rectifying the ultrasonic probe sensitivity. This method also can be applied to evaluate the probe performance in clinical fields without numerical analysis and precise measurements. In this paper, we propose the method of acoustic field pattern analysis with probe channel division for the evaluation of diagnostic ultrasound probe characterization. In order to verify our purpose, we performed a set of experiments. We measured the acoustic-field pattern of the three inferiority probes by channel division to evaluate an acoustic field distribution and impulse response characteristics. By comparing the results of acoustic field measurement method with that of conventional method such as impulse response and live image test for linear array probes, it is demonstrated that the ultrasound field measurement method is more effective then conventional method in detection of defective elements.

PMMA 유기 게이트 절연막의 농도와 두께에 따른 특성

유병철,공수철,신익섭,신상배,이학민,박형호,전형탁,장영철,장호정,Yoo, Byung-Chul,Gong, Su-Cheol,Shin, Ik-Sub,Shin, Sang-Bea,Lee, Hak-Min,Park, Hyung-Ho,Jeon, Hyung-Tag,Chang, Young-Chul,Chang, Ho-Jung 한국반도체디스플레이기술학회 2007 반도체디스플레이기술학회지 Vol.6 No.4

The MIM(metal-insulator-metal) capacitors with the Al/PMMA/ITO/Glass structures were manufactured according to various PMMA concentration of 1, 2, 4, 6, 8 wt%. The lowest leakage current and the largest capacitance were found to be 2.3 pA and 1.2 nF, respectively, for the device with 2 wt% PMMA concentration. The measured capacitance of the devices was almost same values with the calculated one. The optimum film thickness was obtained at the value of 48 nm, showing that the capacitance and leakage current were 1.92 nF, 0.3 pA at 2 wt%, respectively. From this experiment, the PMMA gate insulator films can be applicable to the organic thin film transistors.

디이젤기관에 있어서 매타놀의 사용

유병철,Yoo, Byung Chul 대한기계학회 1979 대한기계학회논문집 Vol.3 No.1

Methanol was examined as supplemental fuel for open chamber type and pre-combustion chamber type diesel engine. Pre-determined quantities of diesel oil were injected as ordinary diesel engines and methanol was added at inlet pipe using venturi, nozzel and and float chamber for the rest of the charge. In this mode of operation, addition of methanol reduced inlet and exhaust temperature. Inlet air quantities were essentially unchanged in spite of lower inlet temperature. Exhaust smoke was significantly reduced At light load when both diesel oil and methanol were introduced with small quantities, specific heat consumption was considerably increased. However, with the increase of the quantity of methanol or diesel oil, specific heat consumption was improved. With sufficient quantities of diesel oil enough to produce the power above 3/4 load, addition of methanol showed better thermal economy.

연구논문 : 사형수신드롬에 관한 질적 연구

유병철 ( Byung Chul Yoo ) 한국형사정책학회 2015 刑事政策 Vol.27 No.1

This article relates to criminological implications how physical circumstances and psychological experiences harmfully affect death-row prisoners. They should have been executed right after their final verdict, however, they have endured their life for long period of time without execution. Since they can be put to death legally and practically at any time, they have lived under the extreme stresses and experienced deathlike fears for the long time. With a stigmatized red name-tag outrightly different from others, their everyday life on a death row has been lonely and disconnected causing the fear of death. None has discussed the so-called death-row syndrome and the circumstances and experiences of death-row prisoners in Korea. As an active prison warden, the author interviewed in-depth thirteen convicts on death-row and analysed qualitatively their narratives about their physical circumstances and psychological experiences. Recently they could get along with other prisoners in prison cells and participated in working at prison factories. For all the changed conditions of death-row prisoners, the article discloses that their conditions and experiences relate to the so-called death-row syndrome. It is proved by delayed execution, poor conditions, and deteriorated psychological sufferings. Therefore, death-row syndrome should be considered on the issues of the abolition and execution of death penalty.

사형수신드롬에 관한 질적 연구

유병철(Byung Chul Yoo) 한국형사정책학회 2015 刑事政策 Vol.27 No.1

This article relates to criminological implications how physical circumstances and psychological experiences harmfully affect death-row prisoners. They should have been executed right after their final verdict, however, they have endured their life for long period of time without execution. Since they can be put to death legally and practically at any time, they have lived under the extreme stresses and experienced deathlike fears for the long time. With a stigmatized red name-tag outrightly different from others, their everyday life on a death row has been lonely and disconnected causing the fear of death. None has discussed the so-called death-row syndrome and the circumstances and experiences of death-row prisoners in Korea. As an active prison warden, the author interviewed in-depth thirteen convicts on death-row and analysed qualitatively their narratives about their physical circumstances and psychological experiences. Recently they could get along with other prisoners in prison cells and participated in working at prison factories. For all the changed conditions of death-row prisoners, the article discloses that their conditions and experiences relate to the so-called death-row syndrome. It is proved by delayed execution, poor conditions, and deteriorated psychological sufferings. Therefore, death-row syndrome should be considered on the issues of the abolition and execution of death penalty.

[論文] 4氣筒 4사이클 스파크 點火機關 吸·排氣 系統의 流動에 關한 硏究

유병철(Byung Chul Yoo),이정현(Jung Hyun Lee) 한국자동차공학회 1988 오토저널 Vol.10 No.1

When gas exchange process is to be calculated, the evaluation of the variation of the thermo­dynamic properties with time and position in the intake and exhaust system is required. For this purpose the application of the method of characteristics to the gas exchange process is known as the best method. In order to apply the method of characteristics, the gas flow at carburettor and inlet and exhaust valves must be replaced by some simple models by which thermodynamic properties can be calculated easily giving good agreement with actual values.<br/> In this study, the carburettor is represented by an adiabatic pressure loss model. In this model resistance coefficients of carburettor are obtained by experiment. Using these resistance coefficients the pressure drop at carburettor can be calculated.<br/> In order to select adequate average discharge coefficients for the inlet and exhaust valves, mass flow rate through intake and exhaust system is calculated by the method of characteristics using above resistance coefficient at specific engine operating condition and then it is compared with measured mass flow rate. The discharge coefficient is determined so that calculated mass flow rate gives good agreement with the measured mass flow rate.<br/> For the engine used in this study average discharge coefficient of 0.6 gives good agreement with the measured mass flow rate over the whole engine operating conditions.

[論文] 單氣筒 2사이클 壓縮點火機關의 시뮬레이션

유병철(Byung Chul Yoo),김정순(Jung Soon Kim) 한국자동차공학회 1986 오토저널 Vol.8 No.1

The simulation of power cycle and unsteady gas exchange processes in the inlet and exhaust systems of the single-cylinder 2-stroke cycle compression ignition engine was studied in this paper.<br/> In power cycle process, the single-zone model proposed by Whitehouse and Way was used, and the convective and radiative heat transfer from cylinder contents to surroundings was considered. To solve the equations for gas exchange process, the generalized method of charac­teristics including area change, friction, heat transfer and entropy gradients was used. Also with the path line calculation, the entropy change along the path line and the variation of specific heat due to the change of temperature and the composition of cylinder gas were considered.<br/> As a result of the simulation, the change of pressure and temperature in the cylinder again­st the crank angle, the rate of net heat release, and the change of properties at each point in the inlet and exhaust pipe against the crank angle were obtained. The engine performances under various operating conditions were also calculated.

DfD를 위한 부품의 해체순서 결정 소프트웨어 개발

유병철(B. C. Yoo),이건상(K. S. Lee) 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.10월

Today recycling has been one of the most important issues in industry as it is required to save the limited amount of natural resources and to keep the environment green. In spite of many efforts to increase recycling rate in industry, however, the practical solutions are very limited. The difficulties are caused by the existence of many parts made of diverse materials and their inevitably complicated assembly structures to satisfy different needs. This paper represents a study on the disassembly sequence generator system for parts recycling. With disassembly costs and revenues, the optimum disassembly sequence can be found with a linear programming.

베이즈 네트워크를 이용한 탈중앙화 암호화폐 지갑의 정량적 위험성 평가

유병철(Byeongcheol Yoo),김승주(Seungjoo Kim) 한국정보보호학회 2021 정보보호학회논문지 Vol.31 No.4

2009년 비트코인 블록체인이 처음 생성된 이후 암호화폐 사용자는 꾸준히 증가하고 있다. 하지만 이러한 사용자들의 암호화폐 지갑에 보관된 자산을 노리는 해킹 공격도 증가하고 있다. 따라서 우리는 시중에 나와 있는 암호화폐 지갑들이 안전하게 만들어졌는지를 점검하기 위해 각 지갑에 내재된 위험성을 평가한다. 우리는 위협 모델링을 통해 암호화폐 지갑에 내재된 위협을 식별하고 보안 요구사항을 도출한다. 그리고 도출된 보안 요구사항을 바탕으로 실제 지갑들의 보안성을 분석하고 공격트리와 베이즈 네트워크 등을 활용하여 각 지갑의 위험성을 정량적으로 측정한다. 위험성 평가 결과, 하드웨어 지갑보다 소프트웨어 지갑의 평균적인 위험성이 1.22배 높은 것으로 나타났다. 그리고 하드웨어 지갑 간 비교에서는 secure element를 내장한 Ledger Nano S 지갑보다 범용 MCU를 내장한 Trezor One 지갑의 위험성이 1.11배 높은 것으로 나타났다. 하지만 secure element를 사용하는 것은 암호화폐 지갑의 위험성을 낮추는 데에는 상대적으로 효과가 낮은 것으로 나타났다. Since the creation of the first Bitcoin blockchain in 2009, the number of cryptocurrency users has steadily increased. However, the number of hacking attacks targeting assets stored in these users’ cryptocurrency wallets is also increasing. Therefore, we evaluate the security of the wallets currently on the market to ensure that they are safe. We first conduct threat modeling to identify threats to cryptocurrency wallets and identify the security requirements. Second, based on the derived security requirements, we utilize attack trees and Bayesian network analysis to quantitatively measure the risks inherent in each wallet and compare them. According to the results, the average total risk in software wallets is 1.22 times greater than that in hardware wallets. In the comparison of different hardware wallets, we found that the total risk inherent to the Trezor One wallet, which has a general-purpose MCU, is 1.11 times greater than that of the Ledger Nano S wallet, which has a secure element. However, use of a secure element in a cryptocurrency wallet has been shown to be less effective at reducing risks.