생산성 잠재력 분포 영역도와 SA 알고리즘을 이용한 생산정 위치 선정 연구

정지헌(J.H. Jung),권순일(S.I. Kwon) 한국전산유체공학회 2016 한국전산유체공학회 학술대회논문집 Vol.2016 No.7

SA기법을 적용한 유정위치 최적화 모델의 활용성 증진 연구

정지헌(Jihun Jung),한동권(Dongkwon Han),권순일(Sunil Kwon) 한국가스학회 2014 한국가스학회 학술대회논문집 Vol.2014 No.11

딥러닝을 이용한 다중이용시설의 이용자수 조사

정지헌(Jung, Ji Heon),박자연(Park, Ja Yeon),한수희(Han, Soohee) 대한토목학회 2022 대한토목학회 학술대회 Vol.2022 No.10

축산식품중의 중금속 함량에 관한 조사연구

정지헌 ( Ji Hun Jung ),황래홍 ( Lae Hwong Hwang ),윤은선 ( En Sun Yun ),김현정 ( Hyun Jung Kim ),한인규 ( In Kyou Han ) 한국가축위생학회 1999 韓國家畜衛生學會誌 Vol.22 No.1

This study was performed to investigate the contents of the heavy metals such as cadmium(Cd), copper(Cu), iron(Fe), lead(Pb) and zinc(Zn) in meat and meat products. For this experiment, each 20 samples of beef and pork were collected at slaughterhouse in Seoul areas and 45 samples of meat products(ham, sausage, processed meat and seasoned meat) were purchased from commercial food markets. The contents of the heavy metals was determined by atomic absorption spectrophotometry from Jan. to Nov. in 1998. The results obtained were summarized as follows 1. In Korean native beef, mean values of the heavy metals(mg/kg) were Pb: 0.14±0.10, Cd: 0.07±0.02, Cu: 1.73±0.95, Zn: 42.82±8.17 and Fe: 67.43±24.18, respectively. 2. In imported beef, mean values of the heavy metals(mg/kg) were Pb: 0.03±0.08, Cd: 0.06±0.02, Cu: 1.41±0.62, Zn: 42.93± 4.95 and Fe: 40.06± 12.77, respectively. 3. In pork, mean values of the heavy metals(mg/kg) were Pb: not detected, Cd: 0.09±0.02, Cu: 1.08±0.23, Zn: 19.49±6.02 and Fe: 30.21±10.51, respectively. 4. In ham, mean values of the heavy metals(mg/kg) were Pb: trace, Cd: trace, Cu:1.19± 0.46, Zn: 13.58±4.99 and Fe: 31.43±11.74, respectively. 5. In sausage, mean values of the heavy metals(mg/kg) were Pb: 0.15±0.34, Cd: 0.08±0.05, Cu: 1.15±0.46, Zn: 13.70±7.13 and Fe: 27.28±15.05, respectively. 6. In processed meat, mean values of the heavy metals(mg/kg) were Pb: 0.08±0.13, Cd: 0.09±0.04, Cu: 1.28±0.60, Zn: 14.72±7.09 and Fe: 24.04±10.33, respectively. 7. In seasoned meat, mean values of the heavy metals(mg/kg) were Pb:1.05±2.21, Cd: 0.13 ±0.03, Cu: 1.06± 0.16, Zn: 17.53± 8.72 and Fe: 26.76± 9.02, respectively.

연구논문 : 유통 절임배추의 중금속, 잔류농약 및 식중독 안전성 조사

정선옥 ( Sun Ok Jung ),정지헌 ( Ji Hun Jung ),김성단 ( Sung Dan Kim ),이현경 ( Hyun Yung Lee ),박성규 ( Sung Kyu Park ),이병훈 ( Byung Hun Lee ),이정숙 ( Jeong Sook Lee ),김수진 ( Soo Jin Kim ),김동규 ( Dong Gyu Kim ),유인실 ( In 한국식생활문화학회 2015 韓國食生活文化學會誌 Vol.30 No.6

In recent years, consumers have become more interested in convenient lifestyles, leading to increased use of salted cabbages for preparation of kimchi. This study aimed to investigate the safety of heavy metals, pesticide residues, and foodborne pathogens in commercial salted cabbages in Seoul from August to November, 2014. The survey, which was conducted to determine whether or not salted cabbages were prepared under the highest sanitary conditions, showed that Seoulites are interested in purchasing hygienic and safe salted cabbages. The average amounts (range) of Pb and Cd found in 30 salted cabbage samples were 0.007 (0.000~0.063) mg/kg and 0.004 (0.000~0.012) mg/kg, respectively. The cabbages were analyzed for residues from 285 types of pesticides using the multiresidue method. Residues for pesticides were not detected. Major foodborne pathogens, specifically Escherichia coli, Salmonella spp., Listeria monocytogenes, Campylobacter jejuni, Staphylococcus aureus, Vibrio parahaemolyticus, Enterohemorrhagic Escherichia coli, Bacillus cereus, Clostridium perfringens and Norovirus, were also not detected.

서울시 수계시설에서 분리된 Legionella pneumophila의 분자역학적 특성

전수진,정지헌,승현정,김창규,진영희,오영희,최성민,채영주,Jeon, Su Jin,Jung, Ji Hun,Seung, Hyun Jung,Kim, Chang Kyu,Jin, Young Hee,Oh, Young Hee,Choi, Sung Min,Chae, Young Zoo 한국환경보건학회 2013 한국환경보건학회지 Vol.39 No.2

Objectives: The genus Legionella is common in aquatic environments. Some species of Legionella are recognized as potential opportunistic pathogens for human, notably Legionella pneumophila that causes, Legionellosis. Thus, we investigated the contamination of Legionella pneumophila on water supply systems in Seoul, including cooling towers, public baths, hospitals and fountains. Methods: The existence of 16S rRNA and mip gene of L. pneumophila was confirmed in the genome of the isolated strains by PCR. Results: During the summer season of 2010 and 2011, Legionella pneumophila were detected from 163 samples (21.1%) out of 772 samples collected. Among the 163 strains of L. pneumophila, eighty one isolates belonged to serogroup 1 (57.4%), 23 isolates were serogroup 5 (16.3%), 21 isolates were serogroup 6 (14.9%), 8 isolates were serogroup 2 (5.79%), and 8 isolates were identified in serogroup 3 (5.7%). Through PFGE (pulsed-field gel electrophoresis) analysis using Sfi I, genetic types of L. pneumophila were classified into five (A to E) patterns by the band similarity with excess of 70% from public baths. Conclusions: The PFGE patterns of the serotypes showed a tendency for diversity of L. pneumophila. Our results suggest the existence of serological and genetic diversity among the L. pneumophila isolates.

서울시내 수계시설에서 분리된 Legionella spp.의 병원성에 대한 분자역학적 연관성

김진아,정지헌,김수진,진영희,오영희,한기영,Kim, Jin-Ah,Jung, Ji-Hun,Kim, Soo-Jin,Jin, Young-Hee,Oh, Young-Hee,Han, Gi-Young 한국미생물학회 2009 미생물학회지 Vol.45 No.2

Legionella spp. is the causative agent of Legionellosis, which induces a potentially fatal form of pneumonia. With a concentrated performance during the summer of 2008, we secured 73 isolates from the water systems of 25 wards in Seoul. We analysed serotypes, pathogenic genes (Dot/Icm), and patterns of pulsed-field gel electrophoresis (PFGE) in an attempt to confirm relationships among them. Different from the previous year's pattern (2007), among the isolates, 69 were Legionella pneumophila and 4 were Legionella spp. The serotype distribution of Legionella pneumophila was sg1 43, sg6 9, sg5 8, sg3 8, and sg2 1. The serotype for the 4 Legionella spp. was Legionella nautarum. Most of the Legionella pneumophila had several pathogenic genes. On the other hand, the 4 Legionella spp. were defective in pathogenicity in genomic terms. The PFGE patterns of the serotypes showed a tendency for diversity of Legionella pneumophila and a close correlation with genetic pathogenicity. 레지오넬라균은 치명적인 폐렴을 일으킬 수 있는 균으로서, 기후 온난화와 함께 노출의 수위가 높아지고 있는 병원성균이다. 본 연구는 2008년 6월부터 8월까지 서울시내 25개구 소재 수계시설에서 분리한 레지오넬라균 73개 주에 대해 혈청형, Dot/Icm라 일컬어지는 병원성 유전자 분석 그리고 Pulsed field gel electrophoresis (PFGE)를 실시하여 유전자형과 그들 사이의 상관관계를 파악하였다. 73개주 중 69주는 Legionella pneumophila로 혈청형의 분포는 sg1 43주, sg6 9주, sg5 8주, sg3 8주, sg2 1주로 파악되었으며, Legionella spp. 4개주는 Legionella nautarum였다. 분리된 Legionella pneumophila 대부분이 여러 개의 병원성 유전자를 보유하고 있었으며, 반면에 Legionella nautarum은 병원성 유전자가 많이 결핍되어있었다. PFGE pattern을 분석해 볼 때, Legionella pneumophila가 동일한 혈청형안에서 다양하게 분화되어감을 볼 수 있었으며, 병원성 유전자의 분포와 깊은 상관관계를 보였다.

서울지역 소아에서 분리된 Nontyphoid Salmonella의 항생제 내성과 Integron의 특징

진영희,김진아,정지헌,전수진,이재규,오영희,한기영,이영기,Jin, Young-Hee,Kim, Jin-Ah,Jung, Ji-Hun,Jeon, Soo-Jin,Lee, Jae-Kyoo,Oh, Young-Hee,Han, Ki-Young,Lee, Young-Ki 한국미생물학회 2010 미생물학회지 Vol.46 No.4

2003년부터 2009년까지 서울지역 소아에서 분리된 nontyphoid Salmonella 105주에 대해서 혈청형, 항생제 내성양상, integron의 특징과 PFGE를 수행하였다. 혈청형은 총 18종으로 S.Enteritidis가 가장 많이 분리되었고, 그 다음은 Montevide였다. 항균제 내성은 혈청형별로 차이가 있었으나 전체 살모넬라에 대해서 10종의 항균제에 대한 내성률은 ampicillin이 60%로 가장 높았으며, tetracycline 46.7%, streptomycin 35.2%, nalidixic acid 28.6% 순이었다. 다재내성 유형을 알아본 결과 nalidixic acid 단독 내성이 15.7%로 가장 많았고, ampicillinampicillin/sulbactam-tetracycline형이 14.5%, ampicillin-streptomycin-chloramphenicol-tetracycline형이 10.8%였다. Integron에 대한 연구 결과 integron 보유율은 19%로 20주에서 class 1 integron을 가지고 있었고 gene cassette는 20%만 확인이 되었다. 확인된 gene cassette는 aadA2, blaP1과 dfrA12-aadA2, dfr17-aadA5, aadA7이였다. 연도별 분리균의 유연관계를 확인 하고자 가장 분리율이 높은 S. Enteritidis 50주에 대해서 PFGE를 수행한 결과 3가지 Pulsotype으로 나눠어졌다. 3주를 제외한 모든 균주는 similarity 89.8%의 비교적 유연관계가 높은 균임을 확인할 수 있었다. A total of 105 nontyphoid Salmonella isolated from infants in Seoul from 2003 to 2009 was investigated for their serotype, antimicrobial resistance, characterization of integron, and the patterns of Pulsed-field gel electrophoresis (PFGE). Eighteen serotypes were detected in 105 isolates, and the two most common serotypes were S. Enteritidis (47.6%) and Montevideo (15.2%). Among the Salmonella serovars, a high level of antimicrobial resistance was found to ampicilin (60%), tetracycline (46.7%), streptomycin (35.2%) and nalidixic acid (28.6%). In the multi-drug resistance patterns, the predominant patterns were only nalidixic acid (15.7%), ampicillin-ampicillin/sulbactam-tetracycline (14.5%), and ampicillin-streptomycin-chloramphenicol-tetracycline (10.8%). PCR and DNA sequencing analysis revealed the presence of class 1 integron in 20 isolates (19%). Of the class 1 integron positive isolates 20% harboured the integron-associated gene cassettes : aadA2, blaP1, dfr17-aadA5, dfrA12-aadA2, and aadA7. PFGE was carried out to examine the genetic relatedness among S. Enteritidis isolates. Except for three strains, fifty strains were divided by three pulsotypes.

생산자료 분석기법을 이용한 셰일가스정 생산거동 연구

이선민(Sun-Min Lee),정지헌(Ji-Hun Jung),신창훈(Chang-Hoon Sin),권순일(Sun-Il Kwon) 한국가스학회 2013 한국가스학회지 Vol.17 No.4

본 연구에서는 캐나다 셰일가스전에 위치한 2개의 생산정에 대해 생산특성에 따라 적절한 생산자료 분석기법을 이용하여 분석을 수행하였다. Case A 생산정의 경우 생산자료가 매우 가변적으로 나타나 시간과 중첩시간을 적용하여 비교분석을 실시하였다. 유동영역을 구분하기 위해 생산자료를 로그-로그 그래프에 도시한 결과 천이 유동구간만 나타났다. 시간과 중첩시간을 적용하여 자극을 받은 저류층 면적이 각각 180, 240 acres로 산출되었고, 원시가스부존량은 15, 20 Bscf로 계산되었다. 그러나 산출된 저류층 면적은 경계영향유동자료로부터 산출된 것이 아니기 때문에 최소 값으로 판단된다. 이에 저류층 면적과 감퇴지수에 대한 생산성 예측을 수행하였다. 그 결과 감퇴지수가 0.5, 1로 커질수록 궁극가채량이 1.2배와 1.4배로 증가하였다. 또한 저류층 면적이 240에서 360 acres로 커지면 궁극가채량이 1.3배 증가되는 것을 확인할 수 있었다. Case B의 고압 저류층에 위치한 생산정은 상부지층압에 따른 지층압축률과 투과도를 적용하여 분석하였다. 지역학적 영향을 적용한 경우와 아닌 경우를 비교한 결과, 저류층 면적은 1.4배, 원시가스부존량이 1.5배로 증가하였다. 셰일 가스전 현장자료에 대한 분석 결과, 분석 방법에 따라 원시가스부존량, 궁극가채량 등 향후 생산성 예측이 크게 달라지므로 생산자료에 따라 유사시간, 중첩시간, 지역학적 분석 등의 적절한 분석방법을 적용하여야 정확한 생산자료 분석이 가능할 것으로 판단된다. This paper presents production data analysis for two production wells located in the shale gas field, Canada, with the proper analysis method according to each production performance characteristics. In the case A production well, the analysis was performed by applying both time and superposition time because the production history has high variation. Firstly, the flow regimes were classified with a log-log plot, and as a result, only the transient flow was appeared. Then the area of simulated reservoir volume (SRV) analyzed based on flowing material balance plot was calculated to 180 acres of time, and 240 acres of superposition time. And the original gas in place (OGIP) also was estimated to 15, 20 Bscf, respectively. However, as the area of SRV was not analyzed with the boundary dominated flow data, it was regarded as the minimum one. Therefore, the production forecasting was conducted according to variation of b exponent and the area of SRV. As a result, estimated ultimate recovery (EUR) increased 1.2 and 1.4 times respectively depending on b exponent, which was 0.5 and 1. In addition, as the area of SRV increased from 240 to 360 acres, EUR increased 1.3 times. In the case B production well, the formation compressibility and permeability depending on the overburden were applied to the analysis of the overpressured reservoir. In comparison of the case that applied geomechanical factors and the case that did not, the area of SRV was increased 1.4 times, OGIP was increased 1.5 times respectively. As a result of analysis, the prediction of future productivity including OGIP and EUR may be quite different depending on the analysis method. Thus, it was found that proper analysis methods, such as pseudo-time, superposition time, geomechanical factors, need to be applied depending on the production data to gain accurate results.

석탄층 메탄가스(CBM) 유입유동관계 규명을 위한 기술적 고려사항

서형준(Hyeongjun Seo),정지헌(JiHun Jung),권순일(Sunil Kwon) 한국가스학회 2015 한국가스학회 학술대회논문집 Vol.2015 No.11