원자층 증착법으로 성장한 HfO₂ 박막의 제조

김희철,김민완,김형수,김혁종,손우근,정봉교,김석환,이상우,최병호,Kim Hie-Chul,Kim Min-Wan,Kim Hyung-Su,Kim Hyug-Jong,Sohn Woo-Keun,Jeong Bong-Kyo,Kim Suk-Whan,Lee Sang-Woo,Choi Byung-Ho 한국재료학회 2005 한국재료학회지 Vol.15 No.4

The growth of hafnium oxide thin films by atomic layer deposition was investigated in the temperature range of $175-350^{\circ}C$ using $Hf[N(CH_3)_2]_4\;and\;O_2$ as precursors. A self-limiting growth of $0.6\AA/cycle$ was achieved at the substrate temperature of $240-280^{\circ}C$. The films were amorphous and very smooth (0.76-0.80 nm) as examined by X-ray diffractometer and atomic force microscopy, respectively. X-ray photoelectron spectroscopy analysis showed that the films grown at $300^{\circ}C$ was almost stoichiometric. Electrical measurements performed on $MoW/HfO_2$(20 nm)/Si MOS structures exhibited high dielectric constant$(\~17)$ and a remarkably low leakage current density of at an applied field of $1.5-6.2\times10^{-7}A/cm^2$ MV/cm, probably due to the stoichiometry of the films.

국내 최장대 도로터널(인제터널)의 시멘트광물계 급결제 적용사례

김희철,김대형,조남섭,김관일,Kim, Hui-Cheol,Kim, Dae-Hyeong,Jo, Nam-Seop,Kim, Gwan-Il 한국터널지하공간학회 2011 자연, 터널 그리고 지하공간 Vol.13 No.6

산발성 위암에서 Microsatellite Instability 빈도와 hMLH1 촉진자부위 메칠화

김희철,노선애,육정환,오성태,김병식,유창식,김진천,Kim Hee Cheol,Roh Sun Ae,Yook Jeong Hwan,Oh Sung Tae,Kim Byung Sik,Yu Chang Sik,Kim Jin Cheon 대한위암학회 2003 대한위암학회지 Vol.3 No.1

Background: An aberrant function of the mismatch repair system has been reported to underlie carcinogenesis in several tumors, including colorectal and gastric carcinomas, and to induce the typical genotype of microsatellite instability (MSI). Purpose: We aimed to determine the frequency of MSI in early-onset sporadic gastric carcinoma and elucidate the role of promoter methylation in hMLH1 as the mechanism of MSI. Materials and Methods: Thirty-six early-onset sporadic gastric carcinomas were analyzed to determine the status of MSI and the frequency of methylation of the promoter region in hMLH1. MSI was determined using five markers recommended by NCI: MSI-H (high), MSI-L (low), and MSS (Microsatellite stable). Methylation specific PCR (MSP) and direct automated genomic sequencing analysis with DNA modified by sodium bisulfite have been performed to confirm promoter region methylation. All the data were analyzed regarding characteristics of molecular changes, and clinicopathologic variables. Results: The microsatellite status was determined as MSI-H in five cases ($13.8\%$), MSI-L in 13 cases ($36.1\%$), and MSS in 18 cases ($50.0\%$). hMLH1 was methylated in seven cases ($19.4\%$). In all cases of MSI-H, promoter of hMLH1 was methylated, and in two of the 13 cases of MSI-L, hMLH1 promoter methylation was identified. Methylation was not found in any cases of MSS. Promoter methylation in hMLH1 was significantly correlated with MSI status (P<0.001). We could not find any relationship between MSI and clinicopathologic parameters. Conclusion: These results suggest that an abnormal function of the mismatch repair system may be associated with gastric carcinogenesis in more than $10\%$ of early-onset gastric carcinomas and MSI appeared to be closely related to the promoter methylation in hMLH1.

Bell's Palsy와 Ramsay Hunt Syndrome 환자군의 치료 기간에 따른 호전도의 비교 연구

김희철,김정호,김영일,Kim, Hee-Chul,Kim, Jeong-Ho,Kim, Young-Il 대한침구의학회 2008 대한침구의학회지 Vol.25 No.4

Objectives : The aim of this study is comparing the improvement of Bell's palsy and Ramsay hunt syndrome according to treatment duration. Methods : The 11cases diagnosed as Ramsay hunt syndrome and 30cases of Bell's palsy who visited Cheong-ju Oriental Medical hospital from February 2006 to June 2008 were evaluated. We used Yanagihara's unweighted Grading System to confirm the improvement. Results : In the analysis of cause, except the "none", the most common cause was "Overwork" in both two group. After 5-day treatment the score was getting worse but after 10-day treatment score was improved in both group. The improvement of Bell's palsy group was better than that of Ramsay hunt syndrome group after 5-day and 10-day treatment, but there was no significance. Conclusions : In comparison of Yanagihara's unweighted grading score checked before treatment, after 5-day, 10-day and 15-day treatment between Bell's palsy and Ramsay hunt sundrome, there was no statistical significant difference.

그라우팅 자동관리 시스템(AGS)을 이용한 동홍천-양양 고속도로 14공구 저토피구간 강관보강그라우팅 시공사례

김희철,장기영,김진춘,이왕준,김병용,Kim, Hui-Cheol,Jang, Gi-Yeong,Kim, Jin-Chun,Lee, Wang-Jun,Kim, Byeong-Yong 한국지반공학회 2011 지반 : 한국지반공학회지 Vol.27 No.3

건강한 기상을 위한 최적의 렘 수면기 알람기능 베개의 센싱 장치 개발

김희철,Kim, Hee-Chul 한국전자통신학회 2016 한국전자통신학회 논문지 Vol.11 No.2

사람은 하루 7~8시간 잠자는 동안 20~30번 자세를 바꿈으로 해서 최적의 수면 활동을 유지하려 한다. 최적의 수면을 제공하기 위해서는 베개 내부에 코골이 습관은 물론이고 개인의 수면 패턴을 감지할 수 있는 Sensing시스템과 Sensor에서 출력되는 정보를 분석 가공하는 프로그램 및 정보를 제공하는 디스플레이 장치를 통해 파악된 각종 수면 데이터를 효과적으로 활용하기 위한 센싱 장치의 개발이 필요하다. 본 논문에서는 수면 중 인 사람의 뒤척임을 감지해 수면 패턴을 분석하고 분석된 자료를 바탕으로 수면 건강에 대한 적극적인 관리 할 수 있는 웰빙 베개를 개발하고자 한다. People try to maintain optimal sleep activity to a changing attitude 20-30 times while sleeping 7-8 hours a day. In order to provide optimal sleep, we need to develop sensing device for apply effective various sleep data acquired through display device that can provide program and information which process and analyze information printed out from sensor and sensing system. In this paper, we analyze sleep pattern to detect the toss and turn while a person's sleeping and we develop a wellness pillow that can be active on sleep health management based on the analyzed data for sleep patterns.

독활기생탕(獨活寄生湯)이 백서(白鼠)의 혈액(血液)에 미치는 영향(影響)

김희철,Kim, Hui-Cheol 대한한방내과학회 1995 大韓韓方內科學會誌 Vol.16 No.2

In order to study the effect of Dokwhalgisaentang on the blood in normal rats with Dokwhalgisaentang extract solution was adminstrated in rats. The rats carried on every day for 5days, l0days and 15days respecitively on the corresponding blood in rats, and thereafter the contents of serum BUN, creatinine, creatine, total protein, albumin, total bilirubin, cholesterol were measured in rats. The following results have been obtained : 1. Dokwhalgisaentang extract decreased the serum BUN significantly in rats. 2. Dokwhalgisaentang extract decreased the serum creatine significantly in rats. 3. Dokwhalgisaentang extract decreased the serum creatinine significantly in rats. 4. Dokwhalgisaentang extract decreased the serum total protein significantly in rats. 5. Dokwhalgisaentang extract decreased the serum albumin significantly in rats. 6. Dokwhalgisaentang extract increased the serum total bilirubin significantly in rats. 7. Dokwhalgisaentang extract decreased the serum cholresterol significantly in rats.

독립형 태양광 가로등 통합제어기 개발

김희철,Kim, Hee-Chul 한국전자통신학회 2014 한국전자통신학회 논문지 Vol.9 No.6

독립형 태양광발전시스템은 배전선로와 계통 연계되지 않고 독립적으로 운영된다는 장점이 있어 시공설비가 간단하고 비용이 적게 드는 장점이 있지만 MPPT를 포함한 컨버터와 생산된 에너지를 배터리에 저장하기 위한 충전회로 및 배터리 매니징 회로가 요구된다. 기존의 대체에너지분야의 이용은 복합발전의 형태보다는 하나의 발전 형태를 주로 채택하고 있으나 태양광/풍력 복합발전시스템을 최적설계하고 배터리능력을 향상시켜 설치가격을 합리화 할 수 있는 통합형 제어시스템이 필요하다. Stand-alone PV systems and grid-connected distribution lines operating independently with out the advantage that it is simple, and construction equipment, but the advantage of less expensive MPPT converter and production, including the energy stored in the battery charging circuit and battery for managing circuitry is required. The use of existing alternative energy in the form of combined-cycle power generation than the one adopted by the form, but primarily solar / wind power system to optimize complex to design and improve the ability to install a battery that canrationalize the price you need an integrated control system be.

지수화 지수 커버리지 함수를 고려한 ENHPP 소프트웨어 신뢰성장 모형에 관한 연구

김희철,Kim, Hee-Cheul 한국정보기술전략혁신학회 2007 情報學硏究 Vol.10 No.2

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. Accurate predictions of software release times, and estimation of the reliability and availability of a software product require quantification of a critical element of the software testing process : test coverage. This model called enhanced non-homogeneous poission process(ENHPP). In this paper, exponential coverage and S-coverage model was reviewed, proposes the exponentiated exponential coverage reliability model, which maked out efficiency substituted for gamma and Weibull model(2 parameter shape illustrated by Gupta and Kundu(2001). In this analysis of software failure data, algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE statistics for the sake of efficient model, was employed.

Kappa(2) 커버리지 함수를 이용한 ENHPP 소프트웨어 신뢰성장모형에 관한 연구

김희철,Kim, Hee-Cheul 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.12

유한고장수를 가진 비동질적인 포아송 과정에 기초한 모형들에서 잔존 오류 1개당 고장 발생률은 일반적으로 상수, 혹은 단조증가 및 단조 감소 추세를 가지고 있다. 소프트웨어 제품의 정확한 인도시기를 예측하거나 효용성 및 신뢰성을 예측하기 위해서는 소프트웨어 테스팅 과정에서 중요한 요소인 테스트 커버리지를 이용하면 보다 효율적인 테스팅 작업을 할 수 있다. 이런 모형을 ENHPP모형이라고 한다. 본 논문에서는 기존의 소프트웨어 신뢰성 모형인 지수 커버리지 모형과 S-커버리지 모형을 재조명하고 이 분야에 적용될 수 있는 Kappa 분포를 이용한 모형인 Kappa 커버리지 모형을 제안하였다. 고장 간격시간으로 구성된 자료를 이용한 모수추정 방법은 최우추정법과 일반적인 수치해석 방법인 이분법을 사용하여 모수 추정을 실시하고 효율적인 모형 선택은 편차자승합(SSE) 및 콜모고로프 거리를 적용하여 모형들에 대한 효율적인 모형 선택도 시도 하였다. 수치적인 예에서는 실제 고장자료를 통하여 분석하였다 이 자료들에서 기존의 모형과 Kappa 커버리지 모형의 비교를 위하여 산술적 및 라플라스 검정, 편의 검정 등을 이용하였다. Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. Accurate predictions of software release times, and estimation of the reliability and availability of a software product require Release times of a critical element of the software testing process : test coverage. This model called Enhanced non-homogeneous Poission process(ENHPP). In this paper, exponential coverage and S-shaped model was reviewed, proposes the Kappa coverage model, which make out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE statistics and Kolmogorov distance, for the sake of efficient model, was employed. Numerical examples using real data set for the sake of proposing Kappa coverage model was employed. This analysis of failure data compared with the Kappaa coverage model and the existing model(using arithmetic and Laplace trend tests, bias tests) is presented.