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      • SCIESCOPUSKCI등재

        Modeling of CO₂ Emission from Soil in Greenhouse

        Dong Hoon Lee,Kyou Seung Lee,Chang Hyun Choi,Yong Jin Cho,Jong-Myoung Choi,Sun-Ok Chung 한국원예학회 2012 원예과학기술지 Vol.30 No.3

        Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, CO₂ concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of CO₂ level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse CO₂ enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of CO₂ level. In this study, a mathematical model was developed to estimate the CO₂ emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between CO₂ concentrations at the soil surface and 5-㎝ depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of CO₂ concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict CO₂ emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for CO₂ enrichment in a soil-based greenhouse.

      • KCI등재후보

        반코마이신 내성 장내구균 분리 환자에서 황색포도알균의 내성

        김동욱,신선혜,김혜진,류선,이선희,장철훈,김영대,곽임수 대한감염학회 2004 감염과 화학요법 Vol.36 No.1

        목적 : Vancomycin-resistant enterococci (VRE)로부터 S. aureus로의 vacomycin 내성 유전자의 전파는 오래전부터 예견되어져 왔으며 큰 걱정거리로 남아있다. 최근에 vanA 유전자를 가지고 있는 vancomycin-resistant S. aureus 2주가 미국에서 분리되었다. 이 연구의 목적은 VRE를 보균하고 있는 환자들에서 S. aureus 보균양상과 항균제 내성을 알아보는데 그 목적이 있다. 재료 및 방법 : 2001년 1월부터 2001년 12월까지 부산대학교병원에 입원하였던 환자들 중 임상검체에서 VRE가 분리된 환자 7명과 2001년 9월부터 12월까지 외과 중 환자실에 입원하였던 환자들 중 VRE 감시배양을 시행하였던 20명의 환자들을 대상으로 하였다. 환자들은 전비공, 액와부, 회음부, 직장에서 매주 면봉으로 검체를 채취하였다. 선별배지에서 검체를 배양하여 S. aureus를 분리하였고 원판 확산법을 이용하여 methicillin 감수성을 측정하였다. Broth microdilution 법으로 vancomycin MIC를 측정하였다. 결과 : 총 27명에서 73회의 방문과 292회의 배양이 시행되었으며 총 67주의 S. aureus가 분리되었다. 이중 64주(95.5%)가 methicillin 내성이었다. 전비공 MRSA 보균율은 VRE를 보균하고 있었던 환자는 19명 중 11명(58%)에서, VRE를 보균하지 않았던 환자는 8명 중 3명(37.5%)으로 VRE 보균자에서 보균율이 더 높았다. 총 64주의 MRSA의 vancomycin MIC의 분포는 0.5-2㎍/mL였으며 2㎍/mL를 초과하는 균주는 발견되지 않았다. 64주 중 vancomycin MIC가 1㎍/mL인 균주가 54주(84.4%)로 가장 많았으며 2㎍/mL 6주(9.4%), 0.5㎍/mL 4주(6.3%)의 순이었다. 결론 : VRE 환자에서 S. aureus의 보균율은 비보균자 보다 높았으며 분리된 균주들은 대부분 MRSA였다. VRSA 균주는 발견되지 않았다. Background : The transfer of vancomycin resistance from vancomycin-resistant enterococci (VRE) to Staphylococcus aureus has been predicted. The purpose of this study is to determine the prevalence and antibiotics resistance of S. aureus among patients colonized with VRE. Methods : Between January 2001 and December 2001, a prospective study was performed at Pusan National University Hospital on 27 patients. Surveillance swabs from nasal cavity, axilla, perineum, and rectum were obtained at weekly intervals. Methicillin susceptability of S. aureus was determined by oxacillin disk diffusion test and minimum inhibitory concentration (MIC) for vancomycin by microdilution broth test. Results : Total of 292 swab cultures were performed and 67 S. aureus isolates were collected. 64 isolates (95.5%) were resistant to methicillin. The prevalence of nasal MRSA carrier in 19 patients colonized with VRE was higher than that in 8 patients not colonized with VRE (58% vs. 37.5%). In 64 MRSA isolates, MIC (㎍/mL) for vancomycin ranged from 0.5 to 2. No isolates with MIC >2 ㎍/mL were observed. MIC of 1 ㎍/mL was shown (observed) in 54 isolates, 2 ㎍/mL in 6 isolates, and 0.5 ㎍/mL in 4 isolates. Conclusion : The prevalence of S. aureus with colonization of VRE is higher than that without colonization of VRE. Most of S. aureus isolates were resistant to methicillin. VRSA isolates were not observed.

      • 군집 별 표준곡선 매개변수를 이용한 치밀오일 생산성 예측 순환신경망 모델

        한동권(Dong-kwon Han),김민수(Min-soo Kim),권순일(Sun-il Kwon) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.2

        치밀오일 미래 생산성 예측은 잔류오일 회수량 및 저류층 거동 분석을 위해 중요한 작업이다. 일반적으로 석유공학적 관점에서 감퇴곡선법을 이용하여 생산성 예측이 이루어지는데, 최근에는 데이터기반의 머신러닝 기법을 이용한 연구도 수행되고 있다. 본 연구에서는 딥러닝 기반 순환신경망과 LSTM, GRU 알고리즘을 이용하여 미래 생산량 예측을 위한 효과적인 모델을 제안하고자 한다. 입력변수로는 치밀오일 생산 시 산출되는 오일, 가스, 물과 이와 더불어 다양한 군집분석을 통해 산출된 표준곡선이 주요 매개변수이고, 출력변수는 월별 오일 생산량이다. 기존의 경험적 모델인 감퇴곡선법과 순환신경망 모델들을 비교하였으며, 모델의 예측성능을 향상시키기 위해 하이퍼파라미터 튜닝을 통해 최적 모델을 도출하였다. Predicting future productivity of tight oil is an important task for analyzing residual oil recovery and reservoir behavior. In general, productivity prediction is made using the decline curve analysis(DCA). In this study, we intend to propose an effective model for predicting future production using deep learning-based recurrent neural networks(RNN). LSTM, and GRU algorithms. As input variables, the main parameters are oil, gas, water, which are calculated during the production of tight oil, and the type curve calculated through various cluster analyzes. the output variable is the monthly oil production. Existing empirical models, the DCA and RNN models, were compared, and an optimal model was derived through hyperparameter tuning to improve the predictive performance of the model.

      • Trophic importance of meiofauna to polychaetes in a seagrass (Zostera marina) bed as traced by stable isotopes

        Ha, Sun-Yong,Min, Won-Ki,Kim, Dong-Sung,Shin, Kyung-Hoon Cambridge University Press [etc.] 2014 Journal of the Marine Biological Association of th Vol.94 No.1

        <P> Stable carbon and nitrogen isotope ratios of benthic invertebrates and their potential food sources, such as suspended particulate organic matter (POM), benthic microalgae, attached algae and seagrass, were identified in Dong-dae Bay during the winter. The carbon stable isotope ratios demonstrate that filter feeders, such as oysters (?19.5 ± 1.0‰), use benthic microalgae (?21.2 ± 0.2‰) as a major food, and polychaetes such as Glycera spp. (?14.0 ± 0.6 ‰) preferentially use meiofauna, such as nematodes (?14.0 ± 0.4‰) and copepods (?13.3 ± 1.0‰). These meiofauna may feed on mixed resources (including bacteria) with the isotope ratios between benthic microalgae (?21.2 ± 0.2‰) and seagrass (?9.3 ± 01.0‰). These findings are consistent with the trophic enrichment in the nitrogen isotope ratios (by 3?4‰) between consumers and food sources. Moreover, the results of the MixSIR model based on the observed isotope ratios suggest a large seagrass contribution to the food sources of benthic organisms such as meiofauna (~53.7?62.6%) and macrobenthos (~41.1?68%) through the food web. This model additionally suggests a relatively large contribution of benthic microalgae to the food sources of filter feeders (i.e. 26.4% for oysters). </P>

      • SCIESCOPUSKCI등재

        Modeling of CO<sub>2</sub> Emission from Soil in Greenhouse

        Lee, Dong-Hoon,Lee, Kyou-Seung,Choi, Chang-Hyun,Cho, Yong-Jin,Choi, Jong-Myoung,Chung, Sun-Ok Korean Society of Horticultural Science 2012 원예과학기술지 Vol.30 No.3

        Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of $CO_2$ level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse $CO_2$ enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of $CO_2$ level. In this study, a mathematical model was developed to estimate the $CO_2$ emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between $CO_2$ concentrations at the soil surface and 5-cm depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of $CO_2$ concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict $CO_2$ emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for $CO_2$ enrichment in a soil-based greenhouse.

      • KCI등재

        중년기 우울증 여성의 생활사건, 대처방식, 사회적 지지 및 가족관계

        김동인,이진욱,김임,이선미,은헌정 大韓神經精神醫學會 1997 신경정신의학 Vol.36 No.4

        국문초록본 연구는 중년기 우울증 여성의 생활사건 스트레스, 대처 방식, 사회적 지지, 가족 관계 등의 정신사회적 요인들을 알아보기 위한 것으로 각 변인들이 어떻게 우울과 관계가 있는지를 우울증 환자 집단과 정상인 집단으로 나누어서 비교 연구하였다. 이를 위해 35세 이상 64세 이하의 116명의 우울증 환자와 113명의 정상인을 대상으로 Beck 우울 질문지(BDI), 생활사건 질문지, 대처방식 척도, 대인관계 지지 평가척도(ISEL), 가정환경척도 등의 검사를 하였고 다음과 같은 결과를 얻었다. 1) 최고 스트레스는 환자 집단의 경우 결혼생활 스트레스(42명, 36.2%), 정상인 집단의 경우는 가정생활 스트레스(44명, 38.9%)였다. 2) 소극적 대처(t=0.93, p=.35)만을 제외하고 환자 집단과 정상인 집단에서 BDI 우울 점수(t=15.94, p<.0001), 생활사건 스트레스 점수(t=4.73, p<.0001), 적극적 대처점수(t=6.29, p<.0001), 사회적 지지점수(t=7.20, p<.0001), 가족 관계 점수(t=5.75, p<.0001)에서 유의한 차이를 보였다. 3) 우울증 환자 집단에서 BDI 우울 점수는 생활사건 스트레스(r=.24, p<.01) 변인과 유의한 정적 상관을 보였고, 적극적 대처(r= -.22, p<.01) 변인, 사회적 지지(r= -.35, p<.001) 변인, 가족관계(r= -.30, p<.001) 변인과는 유의한 역 상관을 보였다. 4) 우울증 환자 집단에서 BDI 우울에 대한 각 변인들의 중다회귀분석은 사회적 지지(12.3%, β= -.281, T= -3.162, P=.002, 생활사건 스트레스(5.1%, β=.279, T=3.195, P=.002), 적극적 대처(3.5%, β= -.204, T= -2.225, P=.028) 변인이 합하여 20.9%의 설명력을 나타냈다. 5) 중년기 여성에서 생활사건 스트레스는 가족 관계에서 겪는 스트레스가 가장 큰 스트레스였고, 대처방식은 우울과의 관계에서 일관성이 부족하였으며, 사회적 지지는 우울에 영향을 주는 가장 중요한 요인이었고, 가족관계는 양 집단에서 유의한 차이는 있었으나 우울에 대하여 의미있게 설명하지 못하고 있다. ABSTRACTLife Events, Coping Styles, Social Support, and Family Relationships of Middle-Aged Depressed Women Jin-Wook Lee, M.D., Yim Kim, M.D., Sun-Mi Yi, M.S., Dong-In Kim, M.D., Heon-Jeong Eun, M.D. Department of Neuropsychiatry, Presbyterian Medical Center, Chonju The objective of this study was to explore the psychosocial factors such as life events, coping styles and family relationships in middle-aged depressed women. This study was designed to compare how different variables relate to depression in two different test groups : a depressed patient group and a normal group. The Beck Depression Inventory(BDI), The Ways of Coping Checklist, Interpersonal Support Evaluation List(ISEL), Family Environment Scale were administered to 116 depressed patients and 113 normal persons between the ages of 35 and 64. The results were as follows : 1) The highest stress was marital stress(n=42, 36.2%) in patient group and family stress(n=44, 38.9%) in normal group, respectively. 2) There were significant differences between patient group and normal group in BDI scores(t=15.94, p<.0001), life events(t=4.73, p<.0001), active copinig(t=6.29, p<.0001), social support(t=7.20, p<.0001), and family relationships(t=5.75, p<.0001) except for passive coping(t=0.93, p=.35). 3) In depressed patient group, BDI scores had a significantly positive correlation with the scores of the life events(r=.24, p<.01) and negative correlation with active coping(r= -.22, p<.01), social support(r= -.35, p<.001) and family relationships(r= -.30, p<.001). 4) In depressed patient group, multiple regression analysis showed that social support(12.3%, β= -.281, T= -3.162, P=.002), life events(5.1%, β=.279. T=3.195, P=.002), and active coping(3.5%, β= -.204, T= -2.225, P=.028) had predictability on the BDI scores and the total predictability was 20.9%. 5) Stress experienced in family relationships were highest in life events and there was a lack of consistency(in the BDI scores of the coping styles). Social support was the most important factor and there were no significant differences between the two groups in family relationships.

      • 고체상포집-액체추출방법 및 GC-MS를 이용한 더덕의 향미성분 분석

        이선녀,김남선,김건,이동선 서울여자대학교 자연과학연구소 2006 자연과학연구논문집 Vol.18 No.-

        Codonopsis Radix (Codonopsis lancelata Bentham et Hooker) of the campanulaceae family is a perennial twining vine. Codonopsis Radixis is effective in protecting the stomachics and expectorant. It is an aromatic vine and has very strong sweet volatile compounds. Volatile flavor components of the codonopsis radix have been studied in this paper. The flavor compounds from the codonopsis radix were analyzed by head space solid phase trapping-solvent extraction and gas chromatography - ion trap mass spectrometry. trans-2-Hexenal, 4-methy-1-pentyn-3-ol, limonene, 3-methyl-1, 4-pentadiene, 4-methyl-2-penten-1-ol, trans-2-hexan-1-ol and 3-ethyl- cyclopentene were found as predominant components of codonopsis radix flavors.

      • SCOPUSKCI등재

        Geosynchronous Magnetic Field Response to Solar Wind Dynamic Pressure

        Park, Jong-Sun,Kim, Khan-Hyuk,Lee, Dong-Hun,Lee, En-Sang,Jin, Ho 한국우주과학회 2011 Journal of Astronomy and Space Sciences Vol.28 No.1

        The present study examines the morning-afternoon asymmetry of the geosynchronous magnetic field strength on the dayside (magnetic local time [MLT] = 06:00~18:00) using observations by the Geostationary Operational Environmental Satellites (GOES) over a period of 9 years from February 1998 to January 2007. During geomagnetically quiet time (Kp < 3), we observed that a peak of the magnetic field strength is skewed toward the earlier local times (11:07~11:37 MLT) with respect to local noon and that the geosynchronous field strength is larger in the morning sector than in the afternoon sector. That is, there is the morning-afternoon asymmetry of the geosynchronous magnetic field strength. Using solar wind data, it is confirmed that the morning-afternoon asymmetry is not associated with the aberration effect due to the orbital motion of the Earth about the Sun. We found that the peak location of the magnetic field strength is shifted toward the earlier local times as the ratio of the magnetic field strength at MLT = 18 (B-dusk) to the magnetic field strength at MLT = 06 (B-dawn) is decreasing. It is also found that the dawn-dusk magnetic field median ratio, B-dusk/B-dawn, is decreasing as the solar wind dynamic pressure is increasing. The morning-afternoon asymmetry of the magnetic field strength appears in Tsyganenko geomagnetic field model (TS-04 model) when the partial ring current is included in TS- 04 model. Unlike our observations, however, TS-04 model shows that the peak location of the magnetic field strength is shifted toward local noon as the solar wind dynamic pressure grows in magnitude. This may be due to that the symmetric magnetic field associated with the magnetopause current, strongly affected by the solar wind dynamic pressure, increases. However, the partial ring current is not affected as much as the magnetopause current by the solar wind dynamic pressure in TS-04 model. Thus, our observations suggest that the contribution of the partial ring current at geosynchronous orbit is much larger than that expected from TS-04 model as the solar wind dynamic pressure increases.

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