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

건강관리코너 - 대장암의 조기진단과 예방

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

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.

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.

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.

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.

일반적인 체외수정 방법과 세포질내 정자주입술로 얻어진 배아의 동결-융해 후 이식의 결과

김정욱,한미현,변혜경,전진현,손일표,궁미경,백은찬,강인수,이호준,Kim, Jeong-Wook,Han, Mi-Hyun,Byun, Hye-Kyung,Jun, Jin-Hyun,Son, Il-Pyo,Koong, Mi-Kyoung,Paik, Eun-Chan,Kang, Inn-Soo,Lee, Ho-Joon 대한생식의학회 1997 Clinical and Experimental Reproductive Medicine Vol.24 No.1

Intracytoplasmic sperm injection (ICSI) recently has been utilized widely as the most successful technique to overcome the unfertilization problem in cases of severe male infertility in couples who could not be treated by conventional IVF. Recently, indications of ICSI have been extended further and more fertilized oocytes become available. Thus, it is necessary to examine the efficiency of freezing the surplus embryos obtained from ICSI. We compared the survival rate and the future outcome of cryopreserved embryos obtained either after conventional IVF or ICSI during the same period. After ICSI or IVF, five best-quality embryos from each patient were transferred in the stimulation cycle and the surplus pronuclear (PN) stage oocytes or multicellular embryos were cryopreserved by slow freezing protocol with 1,2-propanediol (PROH) as a cryoprotectant. A total of 792 embryos from ICSI trial were thawed and 65.2% (516/792) survived. The survival rates of PN stage oocyte, multicellular embryo and PN + multicellular embryo were 63.5%, 68.2%, 64.0%, respectively. After 111 transfers, 34 pregnancies were achieved, corresponding to a clinical pregnancy rate of 30.6% per transfers. We thawed 1033 embryos from IVF trials and 57.5% (594/1033) survived. In IVF cycle, the survival rates of PN stage oocyte, multicellular embryo and PN + multicellular embryo were 58.2%, 65.2%, 40.2%, respectively. Thirty eight clinical pregnancies were established after 134 transfers, corresponding to a pregnancy rate of 28.4% per transfer. The cleavage rate of thawed PN stage oocytes from ICSI trial (61.3%) was significantly higher than those from conventional IVF (53.4%). The developmental rates of good embryo (${\geqq}$ grade II) in thawed PN stage oocytes obtained from conventional IVF and ICSI were 63% and 65%, respectively. We concluded that PN stage oocytes, multicellular embryos resulting from ICSI procedure can be successfully frozen/thawed with reasonable clinical pregnancy rates comparable to those of IVF.

강섬유 및 유기섬유를 혼입한 콘크리트 및 모르타르의 내충격 성능평가

김정욱,김규용,Miyauchi Hiroyuki,남정수,김홍섭 한국구조물진단유지관리학회 2011 한국구조물진단학회 학술발표회논문집 Vol.2011 No.9

In this study, it evaluate impact resistance performance of steel fiber and organic fiber reinforced concrete and mortar. The type of organic is polypropylene and polyvinyl alcohol. Percentage of fiber is 0.1, 0.5, 1.0%. It evaluate impact resistance performance to projectile 7, 10㎜ size and 350㎧ by high speed impact testing device.

공공투자사업의 입·낙찰 분석

김정욱,Kim, Jungwook 한국개발연구원 2010 韓國 開發 硏究 Vol.32 No.2

공공투자사업에서는 최저가낙찰제, 턴키 제도, 대안입찰제 등 다양한 방식이 사용되고 있다. 최근 가격경쟁을 통한 효율성 제고를 주목적으로 하는 최저가낙찰제가 확대되어 시행되고 있다. 본 논문은 우리나라 입 낙찰 제도의 현황과 특징을 파악하고, 대형 공공투자사업에 주로 적용되는 최저가 낙찰제, 턴키 대안 입찰제도하에서의 가격 경쟁효과가 직접적으로 드러나는 낙찰률을 비교 분석하는 것에 의미가 있다. 각 입찰제도의 성과는 경쟁의 행태에 달려 있음을 고려하여 경쟁률과 낙찰률을 중심으로 여러 입찰제도의 입 낙찰 현황을 분석하였다. 1,000억원 이상 사업의 경우 최저가낙찰제하에서 평균 입찰참여자 수는 33.75명, 평균 낙찰률은 61.18%로 나타나, 턴키 대안 입찰제의 평균 입찰참여자 수 2.94명, 평균 낙찰률 90.20%와 큰 차이를 보였다. 최저가낙찰제의 경우 규모의 차이를 고려한다 하더라도 낙찰률이 현저히 낮으며, 경쟁의 정도가 심한 것을 확인할 수 있다. 이러한 낙찰률의 차이는 근본적으로 제도의 차이로 해석할 수 있으며, 경쟁의 차이로도 일부 해석할 수 있다. 민간투자사업의 경우, 평균 입찰참여자 수는 1.88명이며, 평균 낙찰률은 90%에 이르고 있어 경쟁 활성화를 통해 효율성을 제고할 여지가 있음을 제시하였다. This paper considers the effect of various types of procurement auction system on competition focusing on the rate of successful bidding. We analyze the number of bidders and the rate of successful bids using online procurement data of the Public Procurement Service. The average number of bidders is 301 and the average rate of successful bids is 87.42% while the weighted average rate is 75.13%. These numbers show that there is quite strong competition among bidders and the rate is lower as the expected price is higher. When we analyze the data of price procurement auction, the rate is also shown to be lower as the expected price is higher. Furthermore, the rate decreases as the number of bidders increases which naturally makes the competition stronger. Meanwhile, the analysis finds that the inclusion of the onsite bidding, the PQ(Pre-Qualification) result, or major-10 winning companies cannot explain the rate much in our data. In case of turnkey-alternative, the average rate of successful bidding for 484 cases record 90.20%. The average is 84.89% with 120 alternatives and 91.97% with 364 cases of turnkey. The reason why the rate of turnkey-alternative is lower than that of price procurement auction is the lack of competition as well as the systematic difference. By setting up a model, we are able to explain the difference in rate caused by the respective reason. When we suppose there are 3 bidders in case of price procurement auction for a project that exceeds 100 billion won, the rate is expected to be around 64%. This implies that difference of 26% is caused by the systemic difference and 3% by the lack of competition. Therefore, we conclude that the difference in rate between turnkey-alternative and price procurement auction is caused mainly by the systemic difference. In case of PPP(Public Private Partnership) projects, among 154 projects in total, only 40% has more than 2 bidders that compete. The average number of bidders is 1.88 which is less than 2, and the average rate of successful bids is 90%. In sum, under the price procurement auction, there is strong competition which is reflected by the rate of successful bids. However, there is room to decrease the rate by strengthening the competition under the turnkey-alternative. Also with PPP projects, we expect the rate can be steadily reduced with revived competition among bidders.

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.