p-Pillar 영역의 두께와 농도에 따른 4H-SiC 기반 Superjunction Accumulation MOSFET 소자 구조의 최적화

정영석,구상모,Jeong, Young-Seok,Koo, Sang-Mo 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.6

In this work, static characteristics of 4H-SiC SJ-ACCUFETs were obtained by adjusting the p-pillar region. The structure of this SJ-ACCUFET was designed by using a two-dimensional simulator. The static characteristics of SJ-ACCUFET, such as the breakdown voltages, on-resistance, and figure of merits, were obtained by varying the p-pillar doping concentration from $1{\times}10^{15}cm^{-3}$ to $5{\times}10^{16}cm^{-3}$ and the thickness from $0{\mu}m$ to $9{\mu}m$. The doping concentration and the thickness of p-pillar region are closely related to the break down voltage and on-resistance and threshold voltages. Hence a silicon carbide SJ-ACCUFET structure with highly intensified breakdown voltages and low on-resistances with good figure of merits can be achieved by optimizing the p-pillar thickness and doping concentration.

용액 공정으로 형성된 n-ZTO/p-SiC 이종접합 열처리 효과

정영석,구상모,Jeong, Young-Seok,Koo, Sang-Mo 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.8

We investigated the effects of annealing on the electrical and thermal properties of ZTO/4H-SiC heterojunction diodes. A ZTO thin film layer was grown on p-type 4H-SiC substrate by using solution process. The ZTO/SiC heterojunction structures annealed at $500^{\circ}C$ show that $I_{on}/I_{off}$ increases from ${\sim}5.13{\times}10^7$ to ${\sim}1.11{\times}10^9$ owing to the increased electron concentration of ZTO layer as confirmed by capacitance-voltage characteristics. In addition, the electrical characterization of ZTO/SiC heterojunction has been carried out in the temperature range of 300~500 K. When the measurement temperature increased from 300 K to 500 K, the reverse current variation of annealed device is higher than as-grown device, which is related to barrier height in the ZTO/SiC interface. It is shown that annealing process is possible to control the electrical characteristics of ZTO/SiC heterojunction diode.

발사체 추진기관 운용 및 제어 개념

정영석,임석희,조규식,오승협,Jeong, Yeong-Seok,Im, Seok-Hui,Jo, Gyu-Sik,O, Seung-Hyeop 한국천문학회 2012 天文學會報 Vol.37 No.2

발사체 추진기관은 추진제 및 각종 고압가스류를 엔진으로 공급하는 기능, 지상에서 추진제를 발사체로 충전/배출하는 기능, 저온 산화제를 냉각하기 위한 순환 기능, 추진제 탱크를 가압하는 기능, 지상에서 온보드 밸브를 구동하는 기능, 내부 공간 및 라인 퍼지 기능 등을 수행한다. 이와 같은 기능을 수행하기 위해 발사체에는 타 시스템과는 별도로 추진기관 원격제어 시스템을 구성한다. 제어 시스템은 크게 온보드 시퀀스 및 추진제 탱크 압력 제어, 추진제 및 고압가스 충전/배출 제어, 발사체 기능 확인, 내부 기밀 확인 및 발사 직전까지의 상태 모니터링을 위해 구성한 지상측정시스템(GMS), 비행 중 추진기관 상태를 모니터링하기 위한 텔레메트리시스템(TMS)으로 분류한다. 본 논문에서는 일반적인 발사체 추진기관 운용 및 제어 개념을 제어 기능, 시스템 구성, 작동 원리의 단계로 사례와 함께 제시하였다.

표면조도를 가지는 볼록한 면에 충돌하는 제트에 의한 열전달계수 측정

정영석,이대희,이준식,Jeong, Yeong-Seok,Lee, Dae-Hui,Lee, Jun-Sik 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.3

The local Nusselt numbers have been measured for a round turbulent jet impinging on the convex surface with and without rib. Liquid crystal/transient method was used to determine the Nusselt number distributions along the surface. The temperature on the surface was measured to within .+-.0.25 deg. C accuracy using liquid crystal and a digital color image processing system. The experiments were made for the jet Reynolds number (Re) 23,000, the dimensionless nozzle-to-surface distance (L/d) from 6 to 10, the dimensionless surface curvature (d/D) 0.056, and the various rib types (height(d$_{1}$) from 1 to 2 mm, pitch (p) from 6 to 32 mm). It was found that the average Nusselt numbers on the convex surface with rib are higher than those without rib, mainly due to an increase in the turbulent intensity caused by flow separation, recirculation and reattachment on the wall surface. In addition, we compared the results by the steady-state method using the gold-film Intrex with those by the transient method.

신경망 가속을 위한 저항성 메모리의 IR Drop 보상

정영석(Youngseok Jeong),김이섭(Lee-Sup Kim) 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6

We propose a new compensation method to minimize the effect of IR Drop during ReRAM PIM operation. A method of compensating the SAR ADC output by reflecting the IR Drop noise that effects the output of the ReRAM PIM to the reference voltage of the SAR ADC has been proposed. The proposed solution is capable of a significant level of compensation up to 35% of the worst IR Drop.

PVA-ECC에 의해 피복 보강된 RC보의 비틀림 거동에 대한 연구

정영석 ( Yeong Seok Jeong ),권민호 ( Min Ho Kwon ),서현수 ( Hyeon Soo Seo ),김진섭 ( Jin Sup Kim ),김기영 ( Gi Yeong Kim ) 한국복합신소재구조학회 2015 복합신소재학회논문집 Vol.6 No.1

The need to consider torsion in the design of members of a structure has recently been increasing; therefore, many studies on torsion have been carried out. Recent research was focused on the torsional performance of concrete according to the reinforcing materials used. Of particular interest, are torsion studies of beams made of SFRC(steel fiber reinforced concrete), and there has been increasing use of SFRC at construction sites. In contrast, research on the composite PVA-ECC (polyvinyl alcohol-engineered cementitious composite) has only covered its mechanical performance, though it exhibits excellent tensile-strain performance (better than SFRC). Therefore, research on the torsion of concrete beams retrofitted using PVA-ECC is lacking. In this study, the behavior characteristics and performance of reinforced-concrete beams retrofitted by PVA-ECC was investigated experimentally. The experimental results show that the resistance to torsional cracking is increased by PVA-ECC. In addition, the strain on the rebar of the specimen was found to be reduced.

CMP 공정중 패드 표면의 온도분포에 관한 연구

정영석(Youngseok Jeong),김형재(Hyoungjae Kim),정해도(Haedo Jeong) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4

The friction heat generated by the CMP process hasinfluence on removal rate and WIWNU(Within Wafer Non-Uniformity). Therefore, the object of this study in to find the distribution of temperature on pad surface during CMP process. To do this, the authors analyse the kinematics of CMP equipment to verify the sources of friction heat and compare the analysis result with the experimental results. Through the analysis and experiment conducted in this paper, we can predict the distribution of polishing temperature across the pad surface. Furthermore the result could help to predict the process conditions which could enhance the polishing results, such as WIWNU and removal rate of thin film to achieve more effcient process.

외상성 후복막강 혈종 환자의 치료

정영석(Young Seok Jeong),이징용(Jin Yong Lee),김상효(Sang Hyo Kim) 대한외과학회 1991 Annals of Surgical Treatment and Research Vol.40 No.3

초등학생의 기술적 창의성 검사도구 개발 및 타당화

정영석(Young-Seok Jeong),최유현(Yu-Hyun Choi) 한국실과교육학회 2020 한국실과교육학회지 Vol.33 No.4

이 연구의 목적은 초등학생의 기술적 창의성을 측정할 수 있는 검사도구를 개발하는 데 있다. 기술적 창의성 구인을 구명하기 위하여 문헌 연구와 전문가 협의회를 실시하였으며, 도출된 구인들을 토대로 초등학생의 기술적 창의성 검사도구 문항을 개발하였다. 본조사는 전국에 있는 초등학교를 대상으로 층화 군집 표집을 실시하여 총 13개 학교의 1,229명의 학생들을 대상으로 실시하였다. 본조사 결과에 대한 요인 분석, 타당도 분석, 신뢰도 분석, 상관 분석을 통해 기술적 창의성 검사도구의 타당성을 확보하고 최종적으로 37문항을 확정하였다. 연구 결과들을 토대로 결론을 제시하면 다음과 같다. 첫째, 초등학생의 기술적 창의성 검사도구는 기능, 사고, 태도 3개의 상위 요인과 9개의 하위 요인으로 구성되었다. 기능의 하위 요인으로는 도구적 기능, 분석적 기능, 사고의 하위 요인으로는 확산적 사고, 수렴적 사고, 태도의 하위 요인으로는 자아효능감, 과제집착력, 진취성, 개방성, 호기심으로 구성되었다. 둘째, 초등학생의 기술적 창의성 검사도구의 확인적 요인 분석 결과 RMSEA=.057, SRMR=.056, GFI=.868, CFI=.892의 수치를 나타내며, 측정 모형은 전반적으로 적합한 모형으로 판단되었다. 신뢰도 분석 결과 Cronbach s α 계수는 전체 .94, 기능 .87, 사고 .90, 태도 .90, 하위 요인의 경우 .75~.90의 범위로 양호한 것으로 나타났다. 셋째, 초등학생의 기술적 창의성 검사도구와 기술적 창의성향 검사도구, 통합 창의성 척도와의 상관관계를 분석한 결과 모든 요인들이 정적인 상관관계가 있는 것으로 확인되었다. The purpose of this study was to develop test tools that can measure the technological creativity of elementary school students. An expert council was held to explore the factors of technological creativity that are more practical and appropriate for elementary school students. Based on the deduced factors, developed a questionnaire for technological creativity self-assessment for elementary school students. The survey was conducted by sampling stratified clusters of elementary schools across the country, targeting 1,229 students in 13 schools. Through the factor analysis, validity analysis, reliability analysis, and correlation analysis on the results of this study, the validity of the technological creativity self-assessment was secured, and finally 37 questions were finalized. The major findings of this study were as follows: First, TCSA-E consists of three upper factors and nine lower factors. The upper factors are skill, thinking, and attitude. The lower factors of skill are instrumental function and analytical function, the lower factors of thinking are divergent thinking and convergent thinking, and the lower factors of attitude are self-efficacy, task commitment, initiative, openness, and curiosity. Second, The results of a confirmatory factor analysis of TCSA-E were as follows: RMSEA=.057, SRMR=.056, GFI=.868, and CFI=.892. Thus, the measurement model was generally judged to be suitable. Third, TCSA-E’s reliability analysis showed that Cronbach’s α coefficient was of .94, in total, function .87, thinking .90, attitude .90, the sub-factor was found to be good in the range of .75 to .90.

항만하역사업자의 책임

정영석 ( Jeong Yeong Seog ) 한국상사판례학회 2003 상사판례연구 Vol.15 No.-

The international unification of legal principle of liability for all distribution is a matter of importance to the revitalization of general cargo distribution and also the legal system on the liability of terminal operators is an important matter on the whole legal system of liability for cargo distribution. But there is no legal system on the liability of terminal operators in korea. Practically it depends on the principle of civil law and normal business practice. If the contract of stevedoring is concluded, it is very important who is the contractor. Because the contents of liability vary greatly with the contractors. As a general rule, the shippers have three ways to claim damages resulting from loss of or damage to the goods. First, he can claim a compensation for damage from the carrier under the contract. In this case, it can be settled by the interpretation of general principle of civil law and commercial law. Second, he can claim damages on tort against the carrier. This case is almost the same as the upper cases. Third, he can claim damages on tort against the terminal operators. In this case, if the Himalaya clause, any person whomsoever carriage is peformed or undertaken(including all sub-contractors of carrier) can be invoked the benefit of every right, defence and limitation of the carrier, is expressly existed in the contract, the operator will enjoy the benefit of every right as a carrier. But the problem is that the range of compensation for shipper is changed by the clause of a special contract. In spite of the same payment of shipper, why it is that the range of damage compensation for shipper is different? The purpose of this paper is to solve the upper problem. Moreover, the contract of terminal operators, according to the form of a contract, is divided into two forms. First, In the case of the charter-party, the stevedoring contract is concluded between the operator and a shipper. If any damages for goods occurs, the shipper will claim against the operator and have a compensation for damages. Second, In the case of the liner-contract, the shipper is used to enter into a contract with a carrier. Therefore the shipper claims against the carrier for cargo damages. After compensation for damages, the carrier will have the right of compensation for the operator. According as the korean commercial law, the carrier can enjoy the right of immunities and limits of liability for cargo damages of the shipper but the operator must cover all the expanses for the carrier`s damages. Also, if the shipper claims in tort against the operator directly, the operator must have a liability in accordance with the contents of the contract. In the same manner way as upper problem, why must the contents of a claim of damage for the same contract become different with the contractor? This contradiction must not be solved by the present legal system. For that reason, it is need to legislate for the law on the liability and legal position of the operator. So this paper suggests the below principles of legislation. First, it needs to be In harmony with the international unification and the present law on the liability of a carrier. Second, the benefit of immunity and limit of liability of carrier must expand into the liability in tort of the sub-executor of terminal operators.