중대산업사고 예방을 위한 종합위험관리체제(IRMS) 구축에 관한 연구

권혁면,성대현,김재현,임대식,김기영,편무욱,문일,고재욱,이영순,윤인섭 한국안전학회 2003 한국안전학회지 Vol.18 No.3

The Process Safety Management (PSM) by the Law of Industry, Safety and Health has been performed for preventing major accidents of chemical plants since 1996. In terms of preventing chemical accidents more precisely, it is essential to develop a tool for quantitative risk assessment. For this, KOSHA (Korea Occupational Safety and Health Agency) developed an Integrated Risk Management System (IRMS) . The system is designed to assimilate data on chemical plant hazards from external database, to integrate these data with location information (topographic and demographic), and to make them user-friendly accessible. The system consists of several main functions: display of five major Korean petrochemical complex layout, display of equipment layout with its information utilizing the external database, zonation of the hazard effected area with consequence analyses, the most probable accident scenario generation, accident/incident database and calculation of frequency of accident using equipment reliability database, etc. The highlight of IRMS is to provide the risk contours using GIS(Geographical Information System) technology. IRMS is intended to manage hazardous installation more systematically and effectively, to reduce the number of accident remarkably, further minimizing production loss in the plant. The system is now under application to about 500 PSM sites as well as and emergency authorities in Korea by KOSHA (Korea Occupational Safety and Health Agency)

In situ hybridization과 염색체 미세해부에 의한 특정 염색체 띠에 대한 유전자 발굴

홍기정,김현수,전용혁,김현,박선화 고려대학교 의과대학 1996 고려대 의대 잡지 Vol.33 No.1

Recently surmountable amounts of genes are being cloned but it is hard to define the chromosomal location and functions of these genes. In this study, a new technique was developed for cloning genes expressed in the developing human brain with confirmed chromosomal location. The mRNAs were extracted from 18 week old human fetal brain, cDNAs were made by reverse transcription from these mRNAs and Uni-amp cDNAs having Uni-amp adapters a t both ends were made for subsequent PCR. To observe the distribution of the Uni-amp cDNAs on the chromosome, fluorescent in situ hybridization was performed with biotin labeled Uni-amp cDNAs. Among the chromosome bands showing strong hybridization with the cDNAs, lq21, lq25, lq32 and lq42 were microdissected from the chromosome hybridized with unlabeled Uni-amp cDNAs and amplified by PCR with Uni-amp primers. These amplified cDNA fragments were subcloned to plasmid vectors and the nucleic acid sequences were analysed. As a result 18 different clones were confirmed the chromosomal localization. They were categorized as 4 clones of well characterized genes, 3 clones showing low homology with known genes, 5 clones of simply registered uncharacterized human cDNAs, and 6 clones of unknown genes. The evidence suggests that the technique is very useful to clone the genes that express in the developing human brain, with confirmed chromosomal location. In addition, this cloning technique can be used to discover the new genes related with neuronal development in combination with functional screening method.

레진 시멘트의 film thickness가 간접 복합 레진 수복물의 접착 효율에 미치는 영향에 관한 연구

이상혁,최기운,최경규 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.2

본 연구는 여러 레진 시멘트의 film thickness에 따른 상아질과 간접 레진 수복물 간의 미세인장 결합 강도를 측정하고, 각 레진 시멘트의 중합 수축 및 굴곡 강도, 탄성 계수를 비교 분석하며, 접착 계면 및 파단면의 주사전자 현미경 관찰을 통하여 레진 시멘트의 film thickness가 레진 간접 수복물의 접착 효율에 미치는 영향을 평가하고자 시행하였다. 복합 레진형 레진 시멘트인 Variolink II와 Duo-Link, 접착형 레진 시멘트인 Panavia F와 Rely X Unicem의 4가지 레진 시멘트를 사용하였고, 각각의 시멘트를 film thickness에 따라 < 50 μm (control)의 대조군과 50 μm (T50), 100 μm (T100), 150 μm (T150)의 실험군으로 나누어 총 16개의 군으로 분류하였다. 데이터는 ANOVA와 Duncan’s multiple comparison test (p < 0.05)를 이용하여 통계 분석하였으며 다음과 같은 결론을 얻었다; 1. Variolink Ⅱ는 모든 film thickness에서 접착형 레진 시멘트보다 높은 결합 강도를 나타냈지만(p < 0.05), Duo-Link는 대조군을 제외하고는 통계학적 유의차가 없었다(p > 0.05). 2. Film thickness가 증가할수록 복합 레진형 레진 시멘트의 결합 강도는 유의성 있게 감소(p < 0.05)하는 경향을 보인 반면, 접착형 레진 시멘트는 통계학적 유의차가 없었다(p > 0.05). 3. Panavia F는 통계학적으로 유의성 있게 낮은 중합 수축량을 나타냈다(p < 0.05). 4. 굴곡 강도와 탄성 계수는 복합 레진형 레진 시멘트가 접착형 레진 시멘트보다 유의성 있게 높게 나타났다(p < 0.05). 5. FE-SEM 관찰 결과 결합 강도가 높은 복합 레진형 레진 시멘트는 균일한 접착층과 잘 발달된 resin tag 소견을 보였으나, 접착형 레진 시멘트는 불분명한 접착층과 resin tag 소견을 나타냈다. 파단면 관찰에서 복합 레진형 레진 시멘트는 혼합형 파괴 양상을 나타냈으나 접착형 레진 시멘트는 접착성 파괴 양상을 나타냈다. The purpose of this study was to evaluate the effect of film thickness of various resin cements on bonding efficiency in indirect composite restoration by measurement of microtensile bond strength, polymerization shrinkage, flexural strength and modulus, fractographic FE-SEM analysis. Experimental groups were divided according to film thickness (< 50 μm-control, 50 μm-T50, 100 μm-T100, 150 μm-T150) using composite- based resin cements (Variolink Ⅱ, Duo-Link) and adhesive-based resin cements (Panavia F, Rely X Unicem). The data was analyzed using ANOVA and Duncan’s multiple comparison test (p < 0.05). The results were as follows ; 1. Variolink Ⅱ showed higher microtensile bond strength than that of adhesive-based resin cements in all film thickness (p < 0.05) but Duo-Link did not show significant difference except control group (p > 0.05). 2. Microtensile bond strength of composite-based resin cements were decreased significantly according to increasing film thickness (p < 0.05) but adhesive-based resin cements did not show significant difference among film thickness (p > 0.05). 3. Panavia F showed significantly lower polymerization shrinkage than other resin cements (p < 0.05). 4. Composite-based resin cements showed significantly higher flexural strength and modulus than adhesive- based resin cements (p < 0.05). 5. FE-SEM examination showed uniform adhesive layer and well developed resin tags in composite-based resin cements but unclear adhesive layer and poorly developed resin tags in adhesive-based resin cements. In debonded surface examination, composite-based resin cements showed mixed failures but adhesive-based resin cements showed adhesive failures.

구리와 철분말의 사출성형 및 소결

이혁기,이동희,장경옥 연세대학교 산업기술연구소 1991 논문집 Vol.23 No.2

The mixtures of Cu or Fe powders and microcrystalline wax as binder were extruded into the long wire by metal injection molding method and sintered after debinding at different conditions. In the case of coarse(33㎛) and irregular Cu powders, the mixture containing 50 vol% wax was suitable for the uniform mixing and forming when injected at 70℃. Binder in coarse Cu powder mixtures was removed at 300℃ for 10 hours. On the other hand, for the spherical and fine Fe powders(4㎛) 30 vol% wax was appropriate and 78% of wax was removed at 400℃ for 1 hour. The density of sintered Cu specimens reached up to 73% of full density when sintered at 1000℃ for 1 hour, but that of Fe specimens was observed to be as high as 97% when sintered at 1200℃ for 1 hour after the optimum debinding.

웨이블릿 변환과 GPS 정밀시각동기를 이용한 전력계통 고장점 모니터링 시스템에 관한 연구

김기택,김혁수,최정용 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.A

A continuous and reliable electrical energy supply is the objective of any power system operation. A transmission line is the part of the power system where faults are most likely to happen. This paler describes the use of wavelet transform for analyzing power system fault transients in order to determine the fault location. Synchronized sampling was made possible by precise time receivers based on GPS time reference, and the sampled data were analyzed using wavelet transform. This paper describes a fault location monitoring system and fault locating algorithm with GPS, DSP processor, and data acquisition board, and presents some experimental results and error analysis.

산업폐수처리장 방류수의 내분비계 장애작용 평가

오승민,김기서,유병택,장형석,이희성,정규혁 한국환경독성학회 2004 환경독성보건학회지 Vol.19 No.4

This study was designed to investigate potential endocrine disrupting effects of several industrial wastewater effluents discharged from cosmetic, plaiting, paint, textile industry using EROD bioassay and E-Screen assay The results of E-screen assay showed that textile industrial wastewater could act as a full agonist and cosmetics and plaiting industrial wastewater could act as a partial agonist On the contrary, the wastewater discharged from paint industry did not show any estrogenic effect Estrogenic activity in the effluents of cosmetic and paint industrial wastewater was lower than that in the influents indicating that the wastewater treatment process minimized the effects of discharges on water quality Despite of these results, it was recognized that wastewater treatment was not always minimize toxic impact In this study, increased estrogenic effect was observed in the effluents of plating and textile wastewater, and EROD activity was increased in the effluents of cosmetic and plating wastewater.

Chemiluminescence System with Air Pump as a Sensor for Determination of Metal Levels in Rain

Hong, Hyuck-Gi,Lim, H.B. Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.12

A lab-made chemiluminescence system with air pump was developed for monitoring of some metal levels in rain. The air pump enabled injection of 17.7 $\mu$g samples into a glass cell filled with luminol-$H_2O_2$ reagent of typically 300 $\mu$L for chemiluminescence measurement. The monitored trend of total metal ions in the rain collected in our campus was compared with analytical results of each metal ion from GFAAS. The system was also demonstrated to determine $Cr^{6+}$ by reduction to $Cr^{3+}$ using $SnCl_2$. The limit of detection for $Cr^{6+}$ obtained by 4 measurements was 85.0 pg $mL^{-1}$ with a relative standard deviation of 3.4%. Although this system doesn’t have selectivity due to the characteristics of chemiluminescence, application of it to environmental monitoring as a sensor for some transition metal ions was demonstrated.

재미한인 스포츠동호회의 사회적 상호작용성과 기능

이혁기(Hyuck Gi Lee) 한국사회체육학회 2012 한국사회체육학회지 Vol.0 No.48

The purpose of this study was to investigate the function of social interaction within the korean sports community in the United States. Results of this study are following: First, the social interaction within the Korean sports community was defined by three interactions: cooperational interaction, exchange interaction, and conflictive interaction. Cooperational interaction includes the characteristics specific to a group, such as nationality or ethnicity, and it is reflected in the meaning of help, volunteer service, and active participation. Exchange interaction was reported as tacit and invisible order. Conflictive interaction can be formed during arguments within a group or when a retribution relationship is formed. Second, social interaction was defined by three aspects of the functional approach within the Korean sports community: explicit proper function, latent proper function, and latent adverse function. Explicit proper function included several functions such as expansion of social network. health center, improved athletic performance, and Korean societal norms such as making good use of spare time. Capitalization of community, interchange of information among community members, and arousal of ethnic identity were all aspects of the construct of latent proper function. Latent adverse function was explained by examples such as exercise addiction, intergroup conflict, and so on.

시화호 표층퇴적물의 중금속 분석

홍혁기 ( Hyuck Gi Hong ),박종민 ( Jong Min Park ),김동훈 ( Dong Hoon Kim ),임흥빈 ( H. B. Lim ) 한국환경분석학회 2005 환경분석과 독성보건 Vol.8 No.1

학생선수의 지각된 사회적 지지와 역할취득, 자아정체성, 학교생활적응 간의 가설적 인과모형

이혁기(Hyuck Gi Lee),배성원(Sung Won Bae),최정웅(Jeong Woong Choi) 한국사회체육학회 2011 한국사회체육학회지 Vol.0 No.44

The purpose of this study was to analyze the causal model among perceived social support, role taking, self-identity and school adjustment of a student-athlete. For this study, participants were 288 students-athletes from elementary, middle, high school, and colleges; convenience sampling was applied. AMOS 7.0 Program was performed to analyze the Structural Equation Model (SEM). As a result, the social support was a direct effect to the role taking. The role taking was directly influenced to the self-identity and school adjustment. Selfidentity was a direct effect to school adjustment. Finally, social support was indirectly influenced to self-identity and school adjustment.