회수 가능 CANDU 사용후핵연료 처분터널에 대한 열 해석

차정훈,이종열,최희주,조동건,김상녕,윤범수,지준석,Cha, Jeong-Hun,Lee, Jong-Youl,Choi, Heui-Joo,Cho, Dong-Keun,Kim, Sang-Nyung,Youn, Bum-Soo,Ji, Joon-Suk 한국방사성폐기물학회 2008 방사성폐기물학회지 Vol.6 No.2

Thermal assessment of a new CANDU spent fuel disposal system, which improves the retrievability of the spent fuel and enhances the densification factor compared with the Korean Reference disposal System, is carried out in this study. The canisters for CANDU spent fuels are stored for long term and cooled by natural convection in the proposed disposal system for the retrievability. The steady state thermal analyses for proposed CANDU disposal system are carried out with the ANSYS 10.0 CFX code. The thermal analyses are performed through two steps. At the first step, the sensitivity of the disposal tunnel spacing is analysed. The differences of maximum temperatures by several tunnel spacings are calculated at three points in the disposal tunnel. The result shows that the differences of the temperature at the three points are almost negligible because 99% of the decay heat is removed by natural convection. At the second procedure, 60m tunnel spacing with a ventilation system instead of natural convection is considered. The result is applied to the calculation of the canister surface temperature in disposal tunnel as boundary conditions. Consequently, the average and the maximum surface temperature of disposal canisters are $79.9^{\circ}C$ and $119^{\circ}C$, respectively. The inner maximum temperature of a basket in the disposal canister is calculated as $140.9^{\circ}C$. The maximum temperature of the basket meets the thermal requirement for the CANDU spent fuel cladding.

Prediction from Linear Regression Equation for Nitrogen Content Measurement in Bentgrasses leaves Using Near Infrared Reflectance Spectroscopy

차정훈,김경덕,박대섭,Cha, Jung-Hoon,Kim, Kyung-Duck,Park, Dae-Sup Turfgrass Society of Korea 2009 한국잔디학회지 Vol.23 No.1

Near Infrared Reflectance Spectroscopy(NIRS) is a quick, accurate, and non-destructive method to measure multiple nutrient components in plant leaves. This study was to acquire a liner regression equation by evaluating the nutrient contents of 'CY2' creeping bentgrass rapidly and accurately using NIRS. In particular, nitrogen fertility is a primary element to keep maintaining good quality of turfgrass. Nitrogen, moisture, carbohydrate, and starch were assessed and analyzed from 'CY2' creeping bentgrass clippings. A linear regression equation was obtained from accessing NIRS values from NIR spectrophotometer(NIR system, Model XDS, XM-1100 series, FOSS, Sweden) programmed with WinISI III project manager v1.50e and ISIscan(R) (Infrasoft International) and calibrated with laboratory values via chemical analysis from an authorized institute. The equation was formulated as MPLS(modified partial least squares) analyzing laboratory values and mathematically pre-treated spectra. The accuracy of the acquired equation was confirmed with SEP(standard error of prediction), which indicated as correlation coefficient($r^2$) and prediction error of sample unacquainted, followed by the verification of model equation of real values and these monitoring results. As results of monitoring, $r^2$ of nitrogen, moisture, and carbohydrate in 'CY2' creeping bentgrass was 0.840, 0.904, and 0.944, respectively. SEP was 0.066, 1.868, and 0.601, respectively. After outlier treatment, $r^2$ was 0.892, 0.925, and 0.971, while SEP was 0.052, 1.577, and 0.394, respectively, which totally showed a high correlation. However, $r^2$ of starch was 0.464, which appeared a low correlation. Thereof, the verified equation appearing higher $r^2$ of nitrogen, moisture, and carbohydrate showed its higher accuracy of prediction model, which finally could be put into practical use for turf management system. Near Infrared Reflectance Spectroscopy(NIRS)는 짧은 시간 안에 식물의 다양한 영양소를 동시에 정확하고 빠르게 측정할 수 있다. 본 연구는 creeping bentgrass 'CY2' 엽의 여러 가지 기본 요소의 값을 예측하기 위해서 NIRS(근적의선 분광분석기)를 사용하여 측정하였다. 그 결과, 질소와 수분 그리고 탄수화물의 $r^2$은 각각 0.892, 0.925, 0.971이었다. 검량식에 대한 검증에서 $r^2$이 높은 상관관계를 나타냈으므로, 잔디에서 더 많은 연구를 위한 실용화 가능성을 확인 할 수 있었다.

신체전기저항법을 사용한 체지방 측정의 오차원

차정훈(Jung Hoon Cha) 한국발육발달학회 2006 한국발육발달학회지 Vol.14 No.1

Linear and whorled nevoid hypermelanosis 2예

차정훈(Jung Hoon Cha),장호선(Ho Sun Jang),오창근(Chang Keun Oh),권경술(Kyung Sool Kwon),김문범(Moon Bum Kim) 대한피부과학회 2000 대한피부과학회지 Vol.38 No.5

Linear and whorled nevoid hypermelanosis(LWNH) is a congenital disorder characterized by hyperpigmented macules following Blaschko's lines with onset usually in the first year of life. There is no preceding inflammatory event or palpable lesion and mucous membranes, eyes, palms, and soles are spared. Histologically, it is characterized by increased pigmentation of basal layer without pigmentary incontinence or increase in dermal melanophage. It seems that this disorder is not rare but is not well recognized or is confused with other entities. We present two cases of linear and whorled nevoid hypermelanosis in 11-year-old and 20-month-old girls with characteristic clinical and histologic findings. (Korean J Dermatol 2000;38(5):669~673)

피부과 원격진료 상단예의 분석

차정훈(Jung Hoon Cha),오창근(Chang Keun Oh),장호선(Ho Sun Jang),권경술(Kyung Sool Kwon) 대한피부과학회 2001 대한피부과학회지 Vol.39 No.5

N/A Background: Telemedicine(tele+medicine= medicine at a distance) is a health care delivery system to deliver health care to patients at distant sites. In Korea, medical counseling by PC communication is nearly the only available field in the telemedicine at present. However, the concerns of telemedicine is growing as an issue, and dermatologists in Korea should be prepared for the era of teledermatology. Objective: We analyzed the queries of PC communication and the internet. Based on the results of the analysis, we tried to establish a more effective medical counseling system by PC communication and make them basic data to prepare the utilization of telemedicine system. Methods: We analyzed questions and answers in ten sites in a computer mediated communication system from Jan 1 to Dec 31, 1997. Results: The proportion of questions in dermatologic mea among all medical fields was relatively high(8.7-13.4%). The frequency was acne, urticaria, alopecia, and so on, in an order of high frequency, which was different from previous results in a statistical study of outpatients in dermatology. Reasons for questions were to know the treatment method(42.2%), to get the diagnosis (23.7%), and so on. Contents of answers were explanation(46.5%), advice to visit doctors(40.4%), and so on. Conclusion: The proportion of dermatologic questions in telemedicine was high, and there are possibilities of dermatology`s being important in the future of telemedicine. Therefore, dermatologists should be prepared for the future telemedicine era. However, teledermatology should be evaluated thoroughly and improved because we could see some problems in that.

수종의 피부 양성종양, 전구암 및 악성종양에서 telomerase의 활성도

차정훈(Jung Hoon Cha),장호선(Ho Sun Jang),오창근(Chang Keun Oh),권경술(Kyung Sool Kwon) 대한피부과학회 2000 대한피부과학회지 Vol.38 No.12

Background:Telomerase is a ribonucleoprotein complex with RNA-dependent DNA polymerase which is necessary in maintenance of the length of chromosome, and therefore, in preventing genomic instability. Its activity is regarded as an indicator of cell immortalization. So far, there is no comprehensive answer on which step the telomerase activity is required; in some studies, telomerase activity has been found in benign, premalignant, and malignant conditions equally, which means it affects early stage of carcinogenesis, but in other studies, it has been found in malignant conditions at a higher rate. Objective:This study was performed to examine telomerase activity in normal and skin cancer tissues and to assess the role of telomerase in the development of malignant transformation of skin cancer by examining benign, premalignant, and malignant conditions together. Methods:Telomerase activities in four benign skin tumors, five precancerous lesions, and 17 skin cancer tissues of the skin were measured by a method telomeric repeat amplification protocol(TRAP). TRAP assay was also performed on normal control tissue of the same patients and eight skin tissues of the healthy volunteers. Results:Telomerase activity was detected in 50% of benign tumors, 100% of precancerous, and 82% of malignant tissues. Among them, three out of four BCC tissues were shown to contain telomerase activity, whereas normal tissue of the same patients were not. No telomerase activity was detected in all of the eight skin samples of the healthy volunteers. Conclusion:Telomerase activities may be required at early stage of tumorigenesis as these activities are required for further steps down of the oncogenesis. (Korean J Dermatol 2000;38(12):1590~1597)

클라우드 환경에서 개인정보보호를 위한 분산 데이터 관리 기법

차정훈 ( Jeonghun Cha ),강정호 ( Jungho Kang ),박종혁 ( Jong Hyuk Park ) 한국정보처리학회 2020 한국정보처리학회 학술대회논문집 Vol.27 No.2

최근 정보 기술의 발전으로 클라우드 컴퓨팅은 개개인에게 편의성을 제공하도록 기능하지만, 실생활에서 디지털 정보의 의존성을 높이게 되었다. 클라우드 컴퓨팅은 실시간으로 다양한 정보를 교환함으로써 다양한 어플리케이션 서비스를 제공한다. 특히, 사용자가 가지고 있는 정보들을 로컬 서버에 관리하기 어려운 문제를 해결하기 위해 아웃소싱 클라우드 스토리지 서비스를 이용하여 해결할 수 있다. 그러나, 사용자의 데이터를 외부 클라우드 서버에 업로드하여 저장하게 되면, 클라우드 서비스 제공자로 인한 프라이버시 문제가 발생할 수 있다. 최근, 클라우드 서버에서 발생할 수 있는 프라이버시 문제를 해결하기 위해서 사용자의 데이터를 암호화하여 클라우드 서비스 제공자로부터 사용자의 정보를 보호하는 연구가 진행되고 있다. 하지만 이 연구는 시간이 지남에 따라 암호화가 복호화될 수 있으며, 특히 클라우드 서버에서 Offline Bruteforce 공격이 발생할 수 있다. 본 논문에서는 클라우드 환경에서 사용자의 개인정보를 보호하기 위한 기존 연구의 한계점을 분석한다. 기존 연구 분석을 통해 개인정보보호를 위한 요구사항을 도출하고, 이를 기반으로 안전한 분산 데이터 관리 기법에 대해 고찰한다.

목질마루바닥재와 벽체용 재료를 이용한 평판열류계법과 MTPS (Modified Transient Plane Source)법의 열전도율 상관관계 분석

차정훈(Junghoon Cha),서정기(Jungki Seo),김수민(Sumin Kim) 한국가구학회 2011 한국가구학회지 Vol.22 No.2

These days global warming is the most important problem and the most important factor is high emission of carbon dioxide. The 23% of carbon dioxide emission for building construction must be reduced. Thermal conductivity is the most basic factor that can decrease the energy consumption especially insulation. Therefore, an accurate and continuous thermal conductivity measurement can be a way to save energy. In this paper, there are methods about how to investigate thermal conductivity measurements and comparing two methods which are the Heat Flow Meter 436 and TCi.

Edge-oriented Convolution Block과 Random Degradation 기반의 얼굴 중심 방송 영상 초해상화

차정훈(Junghun Cha),황지원(Jiwon Hwang),이민석(Minsuk Lee),전준근(Jungeun Jeon),배성호(Sungho Bae) 한국정보과학회 2022 한국정보과학회 학술발표논문집 Vol.2022 No.06

BIA를 이용한 테니스선수 대상 신체구성평가의 적절성

차정훈(Jung Hoon Cha) 한국체육측정평가학회 2009 한국체육측정평가학회지 Vol.11 No.3

체지방율 측정하기 위해 현장에서 가장 많이 사용되고 있는 방법 중에 하나는 BIA에 의한 체지방율 추정이다. 그러나 BIA는 주로 일반인들을 대상으로 개발되었기 때문에 운동선수들에게 사용하는데 적지 않은 제한이 있는 것으로 알려져 있다. 따라서 이 연구에서는 DEXA와 BIA에 의해 얻어진 체지방율의 비교를 통해 현장방법인 BIA의 타당도를 보고하고, 또한 운동선수들과 일반인의 비교를 통해 운동선수들의 BIA에 사용에 대한 적절성을 규명하고자 하였다. 이를 위해 10년 이상 운동을 한 대학교 테니스 선수 19명(남자 9명, 여자 10명)과 규칙적인 운동 경험이 없는 일반인(남자 10명, 여자 16명)을 대상으로 신장, 체중 및 BIA와 DEXA에 의한 체지방량을 추정하였다. 측정된 자료를 이용해 기술통계 분석을 실시하였으며, 각 BIA 측정기기의 적절성을 규명하기 위해 체지방량을 추정하기 위한 준거방법인 DEXA와의 상관분석과 TEM(Technical error of measurement) 분석을 실시하였으며, bland-altman plot를 산출하였다. 연구결과에 의하면 테니스 선수와 일반인 모두에서 DEXA와 BIA에 의한 체지방율은 높은 상관관계를 나타내고 있으며, DEXA를 준거로 했을 때 BIA에 의한 체지방율의 TEM(측정오차)가 테니스 남자선수(TEM 13%)를 제외하고 다른 모든 집단에서는 10% 이내로 크지 않는 것으로 나타났다. 또한 개별적으로 두 방법간의 차이를 나타낸 bland-altman plot 결과에서도 남녀 모두 허용 오차를 넘는 사례가 없는 것으로 나타나 DEXA와 BIA 방법간의 체지방율은 차이가 없는 것으로 나타났다. 그러나 각 집단별로 DEXA와 BIA에 의한 체지방율의 차이를 검증한 결과를 보면, 일반인 집단과 테니스 여자 선수 집단은 두 방법간에 차이가 없는 반면에 테니스 남자 선수집단의 경우는 DEXA 14.0%fat, BIA 16.1%fat으로 통계적으로 유의한 차이가 있는 것으로 나타났다. 결론적으로 BIA는 남자 테니스 선수들의 체지방량을 추정할 경우 다소 과대 추정할 수 있기 때문에 현장에서 사용하는 때의 이점을 고려한 평가가 필요하다. 그러나 일반인들과 여자 테니스 선수들을 대상으로 한 체지방 평가는 적절한 것으로 판단된다. The purpose of this study was to assess and validate a prediction data for estimation the body composition in tennis players using the bio-electrical impedance analysis(BIA). The body fat rate of 19 tennis players in university students (male 9 & female 10) was estimated by two different methods: dual x-ray absorptiometry (DXA) and BIA respectively; DXA was used as a criterion method. A correlation coefficient r and technical error of measurement (TEM) were calculated for the goodness of fit test index for tennis players. The results showed that high score of a correlation coefficient in two methods (DXA and BIA) have appeared in male and female. While there are within 10% of TEM rate in a female group, over 10% technical error of measurement rate was showed on male tennis player group (13% TEM). There are no different evidence of DXA and BIA method for male and female based on bland-altman plot results. As a conclusion, application of the BIA method for male tennis players need a conservative adapting on assessment of body composition.