생태계 기반 재난위험저감 (Ecosystem-based Disaster Risk Reduction; Eco-DRR)의 역할과 연구방안

김정욱,김형수,김수전,Kim, Jeong-Uk,Kim, Hyeong-Su,Kim, Su-Jeon 한국수자원학회 2020 물과 미래(한국수자원학회지) Vol.53 No.9

디스플레이 응용을 위한 액정 모드

김정욱,윤태훈,Kim, Jung-Wook,Yoon, Tae-Hoon 한국광학회 2013 한국광학회지 Vol.24 No.4

정보디스플레이 기술은 디지털 정보화 사회를 혁신적으로 변화시킨 원동력이다. 액정 디스플레이는 가장 대표적인 평판 디스플레이로서 저소비전력, 경량, 박형 등의 장점을 앞세워 소형에서부터 대형에 이르기까지 다양한 응용분야에 널리 사용되고 있다. 하지만, 더욱 고성능의 디스플레이를 구현하기 위해 끊임없이 연구가 지속되고 있다. 본 논문에서는 액정 디스플레이의 구조 및 구동원리에 대해 설명하고, 액정 모드 기술에 대해 본 연구실에서의 연구를 중심으로 소개하고자 한다. An information display device is a key component in the information society. A liquid crystal display is the most widely used among information display devices. However, its performance still needs to be improved in order to survive in competition with other information display devices. In this paper, we explain the structure and the operation principle of a liquid crystal display device and introduce our recent research activities on liquid crystal mode technology.

Al첨가에 의한 무수축 Mullite-$ZrO_2$ 요업체의 제조에 관한 연구

김정욱,김일수,Kim, Jeong-Uk,Kim, Il-Su 한국재료학회 1995 한국재료학회지 Vol.5 No.7

Al 금속분말을 zircon sand (ZrSiO$_4$)와 A1$_2$O$_3$혼합체에 첨가하여 반응소결시킴으로써 무수축 Mullite-ZrO$_2$, 요업체를 얻고자 하였다. 반응식, 3(Al+Al$_2$O$_3$)+2ZrSiO$_4$$\longrightarrow$3A1$_2$O$_3$ .2SiO$_2$+2ZrO$_2$에 의하여 ZrO$_2$-강화 Mullite 요업체를 제조하였다. Al 분말은 A1$_2$O$_3$에 대해 0-30 무게 퍼센트까지 대체하였다. 평량한 분말을 볼밀하여 혼합 분쇄한 후, 정수압 성형하여 시편을 제조하고, 온도범위 1450-1$600^{\circ}C$에서 3시간 반응소결시켰다. Al의 충분한 산화를 위해, 한편으로는 125$0^{\circ}C$에서 5시간동안 열처리를 거친후 소성온도로 올리기도 했다. Al을 첨가함으로서 반응은 촉진되었으며, 소성수축도 산화한 Al의 부피팽창에 의해 상쇄되어, 무수축요업체 제조의 가능성을 보였다. 박편모양을 한 비교적 큰 Al분말이 잘 분쇄되지 않음으로 해서, Al이 자리했던 곳에 큰 기공을 남겼다. In this paper the manufacture of shrinkage-free in situ Mullite-ZrO$_2$ceramics through the addition of Al base metal powder to the mixture of ZrSiO$_4$and A1$_2$O$_3$was attempt. The ZrO$_2$-strengthened mullite ceramics was prepared after the following reaction form, 3(Al+Al$_2$O$_3$)+2ZrSiO$_4$longrightarrow3A1$_2$O$_3$.2SiO$_2$+2ZrO$_2$Al metal powder was added from none to 30 weight percent to the A1$_2$O$_3$. The powders were mechanically mixed, isostatically pressed and reaction sintered at 1450-1$600^{\circ}C$ for 3hours. The specimens were sintered with and without intrim soaking time for 5 hours at 125$0^{\circ}C$ for the oxidation of Al-powder The addition of aluminium accelerates the reaction and compensate the shrinkage during the sintering through an increase in volume of oxidized Al. Because coarse flake type Al metal powders were not effectively milled, oxidized Al resulted in the relative large pore in the specimen.

조사연구 - 건축음향잔향실의 확산판 설치 및 음장보정

김정욱,Kim, Jeong-Uk 한국화재보험협회 2011 방재기술 Vol.51 No.-

동결수정란 이식주기에서 수정란 융해 후 생존율과 임신율에 영향을 미치는 요인

김정욱,변혜경,염혜원,전진현,박용석,송인옥,송지홍,최범채,궁미경,전종영,강인수,Kim, Jeong-Wook,Byun, Hye-Kyung,Youm, Hye-Won,Jun, Jin-Hyun,Park, Yong-Seog,Song, In-Ok,Song, Ji-Hong,Choi, Bum-Chae,Koong, Mi-Kyoung,Jun, Jong-Young,Kang, 대한생식의학회 2000 Clinical and Experimental Reproductive Medicine Vol.27 No.1

Objective: The purpose of this study was to determine the important factors affecting survival and pregnancy rate in frozen-thawed embryo transfer cycles. Methods: we performed retrospective analysis in 738 cycles of frozen-thawed embryo transfers, in relation to the insemination methods, the freezing stage of embryo, patient's age, infertility factors and the origin of injected sperm in ICSI cycles. After conventional IVF or ICSI, the supernumerary PN stage zygotes or multicellular embryos were cryopreserved by slow freezing protocol with 1,2-propanediol (PROH) as a cryoprotectant. Results: The survival rates of thawed embryos were 69.3% (1585/2287) in conventional IVF group and 71.7% (1645/2295) in ICSI group. After frozen-thawed embryo transfers, 27.0% (92/341) and 32.0% (109/341) of pregnancy rates were achieved in conventional IVF and ICSI group, respectively. There were no significant difference in the survival and pregnancy rates according to the insemination methods, the freezing stage and patient's age. However, the pregnancy rate (36.2%) of male factor infertility was significantly higher than the tubal (27.2%) and other female factor infertility (22.9%). In ICSI group, the origin of injected sperm did not affect the outcome of frozen-thawed embryo transfer cycles. Conclusion: The present study demonstrates that acceptable clinical outcomes can be achieved after the transfer of frozen-thawed embryos regardless of the stage of embryos for freezing, the patient's age and the origin of injected sperm.

19-norandrostenedione이 흰쥐 정소내 스테로이드 대사에 미치는 영향

김정욱,윤용달,Kim, Jeong-Wook,Yoon, Yong-Dal 대한생식의학회 1994 Clinical and Experimental Reproductive Medicine Vol.21 No.3

19-norandrostenedione(19-NORA) is known as an intermediate in the metabolic pathway from androstenedione to estrone. Administration of esterified 19-nortestosterone, anabolic steroid, reduces serum gonadotropin and testosterone concentration, and results in reversible azoospermia in men. 19-NORA have been isolated from testis, but its function in testis is not clear yet. Therefore, this study was designed to determine the effect of 19-NORA on steroidogenesis and on spermatogenesis. 19-NORA was administrated by single intratesticular injection to adult male rats weighing 350-400 g in dose of 1 mg/50${\mu}l$. The serum and testis were collected on 1, 3, 7, 12, 48 hr after injection. The histological differences in testis were observed by routine paraffin method. The concentrations of testosterone and estradiol in serum and in left testis were determined by the conventional radioimmunoassays. One hour after 19-NORA treatment, serum concentrations of testosterone and estradiol increased significantly, compared to those of pre-treated(0 hr) group, and reduced gradually to the control level on 7 hour after injection. The concentration of testosterone in left testis increased slightly 1 hour after injection, and estradiol level increased significantly(p<0.05). Also, testosterone and estradiol level of control group revealed no difference with pre-treated (0 hr) group. Gonad index, structure of seminiferous tubules, and the number of step 7 th spermatid were simillar to control group. The present study suggests that the elevation of testosterone level results from increment of estradiol followed by the rapid metabolism of 19-NORA at 7 hour after injection, and then testosterone concentration may be recovered to control level by feedback mechanism of hypothalamus-hypothysis-testis axis.

개인정보 침해위험이 이용의도에 미치는 영향에 대한 연구 - 국내은행의 스마트뱅킹 서비스 중심으로

김정욱,전영찬,Kim, Jeongwook,Jeon, Youngchan 한국품질경영학회 2017 품질경영학회지 Vol.45 No.3

Purpose: The purpose of this study is how personal information protection risks affect the intention to use domestic smart banking services. VAM(Value based Adoption Model) model is validated as a theoretical background, selecting ease of use, usefulness and perceived security as a benefit factor, and considers perceived cost, technical complexity, and risk of personal information leakage as a sacrifice factor. Methods: The method of this study used questionnaire survey to collect 365 data on suer's perception on smart banking services, and also performed a structural equation modeling method using by AMOS 23. Results: The result of this paper shows that all hypothesis are accepted statistically significant except 1 hypothesis. Conclusion: This research is concluded that perceived value is affected on statistically positive impact on ease of use, usefulness and perceived security, and negative impact on perceived cost and risk of personal information violation, not statistically technical complexity.

건강관리코너 - 대장암의 조기진단과 예방

김정욱,Kim, Jeong-Uk 한국화재보험협회 2004 防災와 保險 Vol.103 No.-

Accredited Endoscopy Unit Program of Korea: Overview and Qualification

김정욱,조유경,Jin-Oh Kim,장재영 대한소화기내시경학회 2019 Clinical Endoscopy Vol.52 No.5

The Korean Society of Gastrointestinal Endoscopy introduced the Accredited Endoscopy Unit Program to enhance endoscopy unitquality through systematic quality management in 2012. It was gradually expanded from training hospitals to institutions with 100+beds, and the criteria for certification were applied according to the actual conditions of each institution. On the basis of the continuouscommunication with the institutions and feedback, the Accredited Endoscopy Unit Program certification criteria were revised in 2019and introduced as follows: (1) the qualification criteria for endoscopy doctors and nurses; (2) facilities and equipment; (3) endoscopicexamination process; (4) performance; (5) disinfection and infection control; and (6) endoscopic sedation. The assessment itemsconsist of essential and recommended items. All essential items must be met for accreditation to be awarded. The assessment criteriafor each evaluation area were revised as follows: (1) upgrading assessment criteria; (2) qualification of endoscopists and reinforcementof quality control education; (3) detailed standards for safety, disinfection, endoscopic sedation, and management instructions; and (4)presentation of new performance measurement of endoscopy and colonoscopy.

자연발생석면 분포지역의 효율적인 조사와 관리 방안

김정욱,정명채,김동진,전기석,이창환,Kim, Jeong-Wook,Jung, Myung-Chae,Kim, Dong-Jin,Jeon, Gee-Seok,Lee, Chang-Hwan 한국지하수토양환경학회 2011 지하수토양환경 Vol.16 No.6

This study presents a state of the art in evaluation on naturally occurring asbestos (NOA) areas and effective strategies for investigation and management of NOA areas in Korea. First of all, we defined and classified the NOA area as compiling various countries' regulations, then discussed the best methods for evaluation and management of NOA for reducing exposure of asbestos in the vicinity of NOA areas. According to the literature survey, a three-steps management strategy was suggested in this study. The first step is a confirmation stage of asbestos contamination possibility and the second step is an assessment stage of asbestos contamination using investigation, analysis, evaluation and reclamation. The final step is a following-up control stage. These three management steps for NOA area will give the maximum effectiveness of NOA control in Korea.