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

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.

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.

위팔두갈래근의 긴갈래와 짧은갈래의 팔굽관절 굽힘 각도에 따른 근활성도 분석

김정욱,박민철,Kim, Jeong-Wook,Park, Min-Chull 대한고유수용성신경근촉진법학회 2020 PNF and Movement Vol.18 No.1

Purpose: This study aimed to investigate the impact of resistance on the muscle activities of the long and short heads of the biceps brachii, according to the elbow angle in supination, and the difference in muscle activity between the long and the short heads. Methods: This study was conducted with 22 men in their 20s who voluntarily agreed to participate. With the glenohumeral joint neutral in a position of supination, the elbow angle was randomly moved to 0°, 30°, 60°, and 90°. Using an 8-channel surface EMG while the participants held a 2-kg. dumbbell, the muscle activities of the long and the short heads of the biceps brachii were measured. The measured data were statistically processed using SPSS for Windows 12.0. For the activities of the short and the long heads according to the angle, a one-way ANOVA was conducted, and subsequently, to check the results of an analysis of the difference between groups, an LSD post-hoc test was conducted. An independent t-test was used to compare the activities of the long head and the short head according to the angles. Results: The analysis of the impact of the load of the dumbbell at each elbow angle on the muscle activities of the long and short heads of the biceps brachii revealed significant differences in both heads (p < 0.05). The result of the post-hoc analysis showed significant differences in both heads at angles between 0° and 30°, between 0° and 60°, and between 0° and 90°. Analysis of the impact of the load of the dumbbell in supination on the muscle activities of the long and short heads showed a significant difference at the angle between 0° and 30° (p < 0.05). Conclusion: The long head of the biceps brachii mainly acts in supination; however, in supination at elbow-bending angles of 60° and 90°, there was no difference in muscle activity between the short head and the long head.

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.

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.

수익형 민간투자사업(BTO) 입찰평가 분석: 도로사업을 중심으로

김정욱,Kim, Jungwook 한국개발연구원 2011 韓國 開發 硏究 Vol.33 No.4

Upon selecting preferred bidder in Public-Private Partnership projects, multi-dimensional procurement auction, where price factor and non-price factor are evaluated, is used. This paper tries to analyze bidding data in BTO road projects. It is shown that a winner tends to get higher score in bidding evaluation, which is partly due to increase in base score as well as fiercer competition among bidders. It turns out that score margin in non-price factor was determinant in selecting winner. Also, there was no competition when the level of bonus point was set too high. For price factor, it costs 730 million KRW per score in construction subsidy by government, while it costs 2.43 billion KRW per score in toll revenue. For non-price factor, it was estimated to cost 2.30 billion KRW. Based on the results, it was suggested that we should have appropriate level of bonus point for first initiator, change in scoring rule in construction subsidy part, adjustment of base score in evaluation. 수익형 민간투자사업의 경우 가격요소와 비가격요소를 동시에 고려하는 다차원 경매제도가 시행되고 있다. 본 논문은 수익형 민간투자사업 중 도로사업의 입찰 평가자료를 분석하여 정책적 시사점 및 개선방안을 제시함을 목적으로 한다. 입찰 평가자료 분석 결과, 평가 1위 사업자들의 득점이 증가하고 있는데, 이는 기본점수의 증가와 경쟁의 심화로 인한 것으로 판단된다. 평가 1위 사업자 선정에는 비가격부문에서 발생하는 점수편차가 결정적인 것으로 제시되었다. 또한 최초제안자 우대점수가 높게 설정된 사업의 경우 경쟁이 발생하지 않음도 확인하였다. 가격부문 중 재정지원부문의 점수별 금액은 평균 7.3억원으로 통행료부문의 점수별 금액 24.3억원과 큰 차이를 보였다. 비가격부문의 점수별 금액은 23.0억원 정도로 추정되어 가격부문과는 다소 차이를 나타내었다. 분석결과를 토대로, 최초제안자 우대점수의 적정 수준 유지, 재정지원부문의 평가방식 개선, 기본점수의 재조정 등이 제언되었다.

민간투자사업의 후생효과 분석

김정욱,문외솔,Kim, Jungwook,Moon, Weh-Sol 한국개발연구원 2013 韓國 開發 硏究 Vol.35 No.3

본 연구는 공공부문과 민간투자사업자를 포함한 일반균형모형을 사용하여 재정사업과 BTL 민간투자사업의 후생 차이를 비교 분석한다. 다른 모든 조건이 동일할 때 정부가 세입 세출을 동일하게 유지해야 한다고 가정할 경우, 민간투자사업하에서의 국민경제 후생수준이 재정사업하에서의 후생수준보다 높은 것으로 나타난다. 정부가 균형재정의 제약을 회피할 목적으로 민간투자사업을 무리하게 추진하는 경우 미래의 임대료가 모두 부채로 간주되기 때문에 상당한 사회적 비용이 초래될 수 있음을 명시적으로 보인다. This study investigates the welfare implications of BTL projects using a general equilibrium model with the public sector and public-private partnerships. We show that when the government is not allowed to run budget deficits but private firms is able to overcome the financial constraint, BTL projects performed by public-private partnerships (PPPs) could be a good alternative and improve the welfare of the model economy. This paper quantitatively investigates excessive expansion of PPP projects and several alternatives to retrieve welfare losses caused by such an expansion. Assuming that future rents of BTL projects are not taken into account, we find the welfare losses up to 20 percent relative to conventional government projects. Finally, we show that it would be possible to reduce the losses by transforming the fully depreciated capital stock of the government projects into much smaller new PPP projects.

건강관리코너 - 대장암의 조기진단과 예방

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

바닥충격음의 동향과 재료적 특성

김정욱,Kim, Jeong-Uk 한국화재보험협회 2005 방재기술 Vol. No.