이중대역(PCS/IMT-2000) 마이크로스트립 패치 안테나 설계 및 구조에 따른 SAR 분석

최윤희,신호섭,김남,박주덕,Choi, Yun-Hi,Shim, Ho-Sub,Kim, Nam,Park, Ju-Derk 한국전자파학회 2004 한국전자파학회논문지 Vol.15 No.1

본 논문에서는 PCS/IMT-2000 이동통신 전화기에 의해 인체 두부에 유기되는 SAR의 1 g 및 10 g 평균 첨두 값을 비교 분석하였다. 평면형 구조인 single-semi-disc MPA와 double-semi-disc MPA를 설계하고, 안테나 설계 파라미터에 따른 공진 특성을 분석하였다. 그 결과 중심주파수 2.0 ㎓에서 대역폭이 15.5 %, 31 %로 나타났다. 그리고 제안한 안테나와 동일한 공진 주파수를 갖는 모노폴 안테나를 설계하여 SAR 값을 비교ㆍ분석하였다. 폴더형 전화기에 부착된 double-semi-disc MPA에 의한 1 g 및 10 g 평균 첨두 SAR 값은 각각 0.811 W/kg과 0.507 W/kg으로 모노폴 안테나의 1.206 W/kg과 0.755 W/kg에 비해 약32.7 % 가량 낮은 것으로 나타났다. 평면형 구조의 안테나는 등방성 방사패턴을 나타내는 모노폴 안테나에 비해 인체 외부 방향으로 지향성 방사 패턴을 나타내어 인체 두부에 유기되는 SAR이 낮은 값으로 나타났다. In this paper, the detection of 1 g and 10 g averaged SAR on human head caused by PCS/IMT-2000 handhold phones is analyzed and discussed. Planar structured Single-Semi-disc MPA and double-Semi-disc MPA is designed and resonance characteristics with variety of design parameters are analyzed. As a result, 2.0 ㎓ center frequency, at the bandwidth of single-semi-disc MPA and double-semi-disc MPA are 15.5 % and 31 %, respectively. And monopole antenna with W4 length is designed and compared with double-semi-disc MPA in SARs. The SARs caused by double-semi-disc MPA on folder type handset are 0.811 W/kg and 0.507 W/kg and are about 32.7 % lower than monopole-1.206 W/kg and 0.7552 W/kg. While the radiation pattern of the monopole antenna is symmetrical, that of planar structured antenna is asymmetrical and SAR caused by double-semi-disc MPA is less than SAR by the monopole antenna.

적응형 웹 사이트 구축을 위한 연관규칙 알고리즘 개발과 적용

최윤희,전우천,Choi, Yun-Hee,Jun, Woo-Chun 한국정보처리학회 2009 정보처리학회논문지D Vol.16 No.3

컴퓨터의 보급과 인터넷의 발달로 인해 데이터의 유통은 증가하고 있으나 전통적인 방법으로는 가치 있고 의미 있는 정보를 획득하는 것은 어렵다. 또한, 정보화 사회에서의 많은 정보 중에서 자신에게 알맞은 정보를 탐사하는 데이터 마이닝의 필요성이 대두되고 있다. 또한 사용자들의 편리한 인터넷 항해를 돕고 적절한 정보를 제공할 수 있는 적응형 웹 사이트에 관한 연구도 필요하다. 본 연구의 목적은 사용자들에게 연관성이 있는 웹 페이지를 연결해 주는 적응형 웹 사이트 구축을 위해 웹 로그 분석을 통한 웹 사이트 사용자들의 행동 패턴을 발견하는 연관규칙 알고리즘의 개발에 있다. 데이터 마이닝의 기법 중에서 연관규칙은 웹 사이트에 접속하는 사용자들의 행동을 파악하는데 효과적이다. 본 논문에서는 웹 사용 마이닝을 이용하여 웹 서버의 로그 데이터를 분석하여 트랜잭션을 구성하고, 사용자들의 행동 패턴을 발견하기 위한 의미 있는 문서만을 추출하여 추출된 문서를 대상으로 발견한 빈발 항목으로 연결리스트를 구성하며, 빈발 패턴을 찾아 웹 페이지에 적용하는 일련의 알고리즘을 제안한다. 제안한 알고리즘의 특징은 첫째, 빈발패턴 발견을 위해 생성하는 연결리스트 이외에는 마이닝 과정에서 다른 중간생성물이 필요하지 않으므로 공간 사용면에 있어 효율적이다. 둘째, 기존의 연관규칙 알고리즘에 비해 데이터 베이스의 스캔 횟수를 줄이고, 시간복잡도를 개선하였다. Advances in information and communication technologies are changing our society greatly. In knowledge-based society, information can be obtained easily via communication tools such as web and e-mail. However, obtaining right and up-to-date information is difficult in spite of overflowing information. The concept of adaptive web site has been initiated recently. The purpose of the site is to provide information only users want out of tons of data gathered. In this paper, an algorithm is developed for adaptive web site construction. The proposed algorithm is based on association rules that are major principle in adaptive web site construction. The algorithm is constructed by analysing log data in web server and extracting meaning documents through finding behavior patterns of users. The proposed algorithm has the following characteristics. First, it is superior to existing algorithms using association rules in time complexity. Its superiority is proved theoretically. Second, the proposed algorithm is effective in space complexity. This is due to that it does not need any intermediate products except a linked list that is essential for finding frequent item sets.

기회균형 선발전형 학생들의 대학만족도와 대학생활에 대한 연구

최윤희,임준묵,Choi, Yoon-Hee,Lim, Joon-Mook 한국콘텐츠학회 2022 한국콘텐츠학회논문지 Vol.22 No.10

This study was conducted to find out the characteristics of H University's students admitted through affirmative action program. The differences between the affirmative action program enrollment students and all students were compared by descriptive statistics and correlation analysis methods. In addition, in-depth interviews were conducted for students who entered the affirmative action program. A qualitative research method was used to analyze the contents of in-depth interviews. The results of the study are as follows. First, the higher the entrance score, the higher the university score for students in the affirmative action program. Second, the college satisfaction of students entering the affirmative action program is higher than that of students enrolled. Third, according to the results of the in-depth interview, the affirmative action program students were both active and not. In conclusion, it is necessary to establish a system in which students can actively prepare for their careers in universities. Accordingly, the expansion of the affirmative action program is likely to contribute to the development of universities.

정조 함수율 및 저장온도에 따른 쌀 품질 특성변화

최윤희,정응기,정진일,김덕수,김선림,김정태,이춘기,손종록,Choi, Yoon-Hee,Jeong, Eung-Gi,Choung, Jin-Il,Kim, Deog-Su,Kim, Sun-Lim,Kim, Jung-Tae,Lee, Choon-Gi,Son, Jong-Rok 한국작물학회 2006 한국작물학회지 Vol.51 No.suppl1

정조 함수율과 저장온도에 따른 쌀 품질 변화를 구명하고자 신동진벼와 동진1호를 함수율 $13{\sim}14,\;15{\sim}16,\;{\sim}18%$로 조절하여 상온 및 저온에서 저장기간에 따른 품질관련 특성을 조사하였다. 1. 정조 함수율이 많고 저장온도가 높을수록 호흡율이 높았으며 함수율에 의한 호흡율의 차이가 저장온도에 의한 차이보다 컸다. 2. 발아율은 16개월 저온저장후 80%이상을 유지하였으나 상온에서는 저장기간이 경과함에 따라 급격히 감소하였으며 12개월 저장까지는 함수율이 높은 $17{\sim}18%$에서 발아율이 높았으나 그 이후에는 $15{\sim}16%$에서 높았고, $13{\sim}14%$에서는 16개월 저장후 10%이하의 낮은 발아율을 나타냈다. 3. 밥의 윤기치는 저장 초기에 급격히 감소하다가 그 후 완만해졌으며 저온에서 상온에 비하여 높았고 함수율이 많을수록 높게 유지되다가 12개월 후에는 큰 차이가 없었다. 4. 현미지방산도는 저장기간이 경과할수록 8개월까지 급격히 증가하였으며 저온에서 상온보다 낮았고, 신동진벼가 동진1호에 비하여 낮은 경향이었다. 5. 식미관능평가치는 상온에 비하여 저온저장에서 양호하였고 신동진벼가 동진1호에 비하여 높았으며 저온저장 16개월 후 신동진벼는 함수율 $17{\sim}18%$에서, 동진1호는 $15{\sim}16%$에서 우수하였으며 상온저장시는 신동진벼와 동진1호 모두 함수율 $15{\sim}16%$에서 좋았다. 6. 식미관능평가치는 현미색도 b값 > 밥의 윤기치 > 현미 색도 L값의 순으로 각각 0.731**, 0.625*, 0.615*의 정의 상관성을 나타냈으며 강하점도, 최고점도, 호화개시온도, 현미 지방산도와는 각각 -0.864**, -0.795**, -0.786**, -0.779**의 고도로 유의한 부의 상관성을 나타냈다. This study was carried out to investigate the relationship between each quality characteristics and changes of grain quality according to storage temperature and moisture contents of rough rice of Dongjin 1 and Siodongjinbyeo. Respiration rate of rough rice and fat acidity of brown rice were increased with moisture contents of rough rice and storage temperature. Germination rate of rough rice was the highest at $17{\sim}18%$ moisture contents of rough rice stored at low temperatures for 12 months. Germiation rate of the stored at low temperature after 16 months was up to 80% however the rate of $13{\sim}14%$ moisture contents of rough rice stored at room temperature was severely decreased to below the 10%. Gloss value of cooked rice was increased with moisture contents of rough rice and the lower storage temperature. Fat acidity of brown rice was lower in Sindongjinbyeo than Dongjin 1 at the lower storage temperature. Sensory score of cooked rice of Sindongjinbyeo which stored at low temperature for 16 months was better than Dongjin 1 and excllent at $17{\sim}18%$ moisture contents of rough rice. Correlations between sensory score of cooked rices and color b value of brown rice, gloss value of cooked rice and color L value of brown rice were significant 0.731**, 0.625*, and 0.615*, resectively, and were also positively significant correlated with break down, peak viscosity, pasting temperature, and fat acidity of brown rice -0.864**, -0.795**, -0.786**, and -0.779**, respectively.

다진생강의 저장성 증진에 관한 연구

최윤희,이상복,김명숙 ( Yoon Hee Choi,Sang Bok Lee,Myeong sook Kim ) 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.2

To improve the quality and prolongation of chopped ginger, they were treated with NaCl, citric acid, ascorbic acid alone or combination of them at 5℃. The browning and stink of chopped ginger were prevented by adding 10% NaCl, 0.5∼2.0% citric acid, but the control became severely browned and deteriorated after 1 month storage. The application of 0.5% citric acid maintained citrine color and decreased the activity of polyphenol oxidase(PPO) more significantly compared to 5.0% NaCl or 0.5% ascorbic acid. Ascorbic acid treatment become browned at 1.0∼2.0% and easily deteriorated compared to citric acid. Citric acid(0.5%) or ascorbic acid (0.5%) treatment was largely variation of pH compared to NaCl(5.0%)+citric acid(0.5%) or NaCl(5.0%)+ascorbic acid(0.5%) treatment during 8 month storage. The activity of PPO in NaCl(5.0%)+ascorbic acid(0.5%) treatment was elevated after 4 month storage. In chopped ginger, NaCl(5.0%)+citric acid(0.5%)+ascorbic acid(0.25%) treatment was more effective than 5.0%+0.1%+0.1%, 5.0%+0.5%+0.1% during 12 month storage.

한국산 무우로부터 Cationic isoperoxidase 의 정제 및 특성규명에 관한 연구

최윤희,박종훈,김승수 ( Yun Hi Choi,Jong Hoon Park,Soung Soo Kim ) 생화학분자생물학회 1989 BMB Reports Vol.22 No.1

A cationic isoperoxidase, designated C₃, was isolated from Korean-radish (Raphanus savatis L.) root. Purification of the enzyme was accomplished by CM-cellulose chromatography and Sephadex G-100 gel filtration. The enzyme was a glycoprotein and its molecular weight was approximately 44,000 as determined by SDS-PAGE and Sephadex G-150 gel filtration. The optimal pH of the purified enzyme was 6.0 for guaiacol and 5.0 for H₂O₂. The Km values for guaiacol and H₂O₂ were 5.6 mM and 0.77 mM, respectively. The Km values against several naturally occurring phenolic compounds were also determined. In comparison with the anionic isoperoxidase A₂ which was previously purified from the same source, C₃ had very high Km values for scopoletin and ferulic acid.

부항요법 후 적외선 체열촬영을 통한 관찰

최윤희,조정훈,장준복,이경섭,Choi, Yun-Hui,Cho, Jung-Hoon,Jang, Jun-Bock,Lee, Kyung-Sub 대한한방체열의학회 2005 대한한방체열의학회지 Vol.4 No.1

Thermal change of thermogram can be induced by heat, drugs, diseases, stress, treatments and so on. Because they changed blood circulation of body surface. Negative treatment have been used in oriental medicine to decrease pain and to purify fluids and it can also change blood circulation of body surface. The purpose of this study was to observe the detail changes of temperature after negative treatment and to know the differences according to the negative pressures by thermography. This study was carried for 5 days and thermogram was operated 15 times. The patient had been treated on the back with electromotive type negative treatment and the treated sites was devides into 4 parts with different negative pressure. The results was that the temperature of all parts rised after treatment and the highest point was 10 minutes after treatment. The differences according to the negative pressures was that the temperature of the 55mmHg part rised particularly than the others and it continued until 40 minutes after treatment. There were no differences between 30mmHg and 40mmHg part. The temperature of 50mmHg part were low than the others during all thermogram.

제조 방법에 따른 쌀 조청의 특성 및 수율

최윤희,백지은,박신영,최혜선,송진,Choi, Yoon-Hee,Baek, Ji-Eun,Park, Shin-Young,Choi, Hye-Sun,Song, Jin 한국식품영양학회 2014 韓國食品營養學會誌 Vol.27 No.3

This study was performed to increase the yield and to reduce the processing times for the preparation to improve the productivity and quality of rice jochung, a traditional food in Korea. In order to evaluate the quality characteristics and yield of jochung, the viscosity, color value, mineral contents and the sensory evaluation were measured. Jochung is prepared from steamed rice (STR), wet-milled rice flour (WRF) and dry-milled rice flour (DRF) by processing methods of rice and reacting times (6 hours or 13 hours) of liquefaction and saccharification. There is commonly added liquefying enzyme for rice liquefaction (0.4%/10 kg rice, at $85{\sim}90^{\circ}C$ for 1 hour or 4 hours) and saccharogenic enzyme with malt (2.5% or 4.5%/10 kg rice, at $56{\sim}60^{\circ}C$ for 5 hours or 9 hours). The inner structural properties of WRF showed the more distinct shape regular structure of uncombined starch particles but the DRF closely maintained particles of rice flour observed by SEM. If processing times for liquefation and saccharification were reduced from 13 hours to 6 hours, the yield of jochungs prepared with WRF increased 8%, the DRF 7%, and the STR 3% respectively and the sensory evaluation as well as color values and overall desirability received high scores. The viscosity, color a and b values of jochung processed with WRF for 6 hours were lower than that processed for 13 hours. The viscosity and color a, b value and Ca content were decreased in the jochung processed with WRF or DRF for 6 hours, but Mg, P and K were increased than that of STR. Jochung processed by 0.4% liquefying enzyme and 2.5% malt with WRF for 6 hours will increase the yield, save manufacturing times and costs and will thereby enable cost-effective techniques.

Purification and Characterization of a Cationic Isoperoxidase from Korean-Radish Root

최윤희,박종훈,김승수,Choi, Yun-Hi,Park, Jong-Hoon,Kim, Soung-Soo 생화학분자생물학회 1989 한국생화학회지 Vol.22 No.1

한국산 무우로부터 cationic isoperoxidase $C_3$를 80% $(NH_4)_2SO_4$ 침전, CM-cellulose chromatography, Sephadex G-100 gel filtration 방법 등을 이용하여 전기이동상에서 하나의 띠로 정제하였다. 정제된 효소는 glycoprotein 이었으며 분자량은 SDS-PAGE와 Sephadex G-150 gel filtration에 의하여 약 44,000으로 나타났다. 정제된 isoperoxidase $C_3$는 guaiacol을 기질로 사용한 경우에 최적 pH가 6.0이었으며, guaiacol과 $H_2O_2$에 대한 Km값은 각각 5.6 mM와 0.77 mM이었다. 여러가지 phenolic compound들에 대한 기질 선호도를 조사한 결과 isoperoxidase $C_3$는 scopoletin, esculetin 그리고 ferulic acid에 대해 높은 Km값을 가지며 anionic isoperoxidase $A_2$와 비교해 볼 때 scopoletin과 ferulic acid에 대하여 기질 친화도가 크게 달랐다. A cationic isoperoxidase, designated $C_3$, was isolated from Korean-radish (Raphanus savatis L.) root. Purification of the enzyme was accomplished by CM-cellulose chromatography and Sephadex G-100 gel filtration. The enzyme was a glycoprotein and its molecular weight was approximately 44,000 as determined by SDS-PAGE and Sephadex G-150 gel filtration. The optimal pH of the purified enzyme was 6.0 for guaiacol and 5.0 for $H_2O_2$. The Km values for guaiacol and $H_2O_2$ were 5.6 mM and 0.77 mM, respectively. The Km values against several naturally occurring phenolic compounds were also determined. In comparison with the anionic isoperoxidase $A_2$ which was previously purified from the same source, $C_3$ had very high Km values for scopoletin and ferulic acid.

대학도서관 사서 역량개발 방향 탐색을 위한 직원교육 현황분석

최윤희,정유경,Choi, Yoonhee,Jeong, Yoo Kyung 한국도서관정보학회 2021 한국도서관정보학회지 Vol.52 No.1

본 연구는 사서의 자기계발 관심영역을 알아보기 위해 대학도서관 사서가 한 해 동안 수강한 교육이수내역을 바탕으로 사서 계속교육의 현황을 파악하고자 하였다. 이를 위해 한국교육학술정보원에서 실시한 대학도서관 통계의 직원 교육훈련 항목을 활용하였으며, 사서들의 교육이수내역 30,404건을 대상으로 직원교육의 핵심 키워드를 부여하고 분류하는 작업을 수행하여 사서의 선호 교육주제, 대학 규모별, 지역별, 월별 관심 있는 교육주제 등의 현황을 살펴보았다. 분석결과, 전체 수강강좌의 주제 중 가장 많이 나타난 직원교육 주제는 'DB이용'과 '자료목록'으로 나타났으며, 대학 유형(대학/전문대학)과 규모, 지역 등에서 사서의 교육훈련 관심영역 간의 차이를 확인하였다. 또한, 사서들에게 요구되는 다양한 역량에 비해 '정보자원 및 평가'와 관련된 주제 영역에 관심이 치우쳐져 있음을 알 수 있었다. 본 연구는 대학도서관 사서들의 교육이수내역 전수조사를 통해 교육의 주제영역에 따른 현황을 파악한 것으로, 향후 대학도서관 사서들의 실질적인 관심사를 반영하고 보다 체계적인 교육과정을 개발하는데 기초자료로 활용될 수 있을 것이다. This study aims to analyze the current status of continuing education for academic librarians based on the records of education. For this purpose, the study investigated the academic librarian's preferences for the topics of continuing education in terms of regional and monthly differences using the 30,404 education records in university and college library statistics of Korean Education and Research Information Service (KERIS). The results shows that 'academic database system' and 'cataloging' were the most preferred topics, and there were topical differences between the academic librarians in university and college.