• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.4
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• pp.29-39
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• 2023

In this study, an analysis of medical waste generation characteristics was conducted, differentiating between ordinary situation and the outbreaks of massive infectious diseases. During ordinary situation, prediction models for medical waste quantities by type, general medical waste(G-MW), hazardous medical waste(H-MW), infectious medical waste(I-MW), were established through regression analysis, with all significance values (p) being <0.0001, indicating statistical significance. The determination coefficient(R2) values for prediction models of each category were analyzed as follows : I-MW(R2=0.9943) > G-MW(R2=0.9817) > H-MW(R2=0.9310). Additionally, factors such as GDP(G-MW), the number of medical institutions (H-MW), and the elderly population ratio(I-MW), utilized as influencing factors and consistent with previous literature, showed high correlations. The total MW generation, evaluated by combining each model, had an MAE of 2,615 and RMSE of 3,353. This indicated accuracy levels similar to the medical waste models of H-MW(2,491, 2,890) and I-MW(2,291, 3,267). Due to limitations in accurately estimating the quantity of medical waste during the rapid and outbreaks of massive infectious diseases, the generation unit of I-MW was derived to analyze its characteristics. During the early unstable stage of infectious disease outbreaks, the generation unit was 8.74 kg/capita·day, 2.69 kg/capita·day during the stable stage, and an average of 0.08 kg/capita·day during the reduction stage. Correlation analysis between generation unit of I-MW and lethality rates showed +0.99 in the unstable stage, +0.52 in the stable stage, and +0.96 in the reduction period, demonstrating a very high positive correlation of +0.95 or higher throughout the entire outbreaks of massive infectious diseases. The results derived from this study are expected to play a useful role in establishing an effective medical waste management system in the field of health care.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.2024-2028
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• 2007

우리나라의 물관련 이슈는 수자원뿐만 아니라 사회, 경제 환경 등의 범위까지 확대되어 복합적이며, 기존 방법론과 기술만으로는 해결에 어려움이 있다. 따라서 새로운 기술적/방법론적 도구 개발의 필요성에 따라 통합수자원관리가 하나의 방법으로 받아들여지고 있다. 통합수자원관리는 지속가능한 수자원관리를 목표로하며, 물과 이와 관련 다양한 요소를 고려하는 통합적인 방법론이다. 그러므로 의사결정에 있어 전체론적인 접근이 필요하며, 세부적인 요소와 요소간의 연관관계를 파악하는 것이 중요하다. 이를 위하여 본 연구에서는 통합수자원관리의 기반 도구 중의 하나인 통합수자원관리 모델링 환경인 WaterRing 시범시스템을 개발하였다. WaterRing은 모델연계에 있어 필수적인 표준성, 사용편의성 및 모델공유를 제공하며, 모델코드 자체보다 모델의 개발에 많은 노력을 기울일 수 있도록 설계되었다. 따라서 수자원분야 및 다양한 분야의 모델을 연계할 수 있다. 모델의 연계를 위하여 기본모델단위를 설정하고 각각의 기본모델단위의 결합을 통하여 보다 큰 시스템으로 구성할 수 있도록 하였다. 기본모델단위는 입력/상태/출력의 세 가지 기본요소와 내부수행 루틴으로 구성되어 있다. 기본모델단위 사이의 결합을 정의하기 위하여 BPM(Business Process Management)(Arkin, 2002)와 STELLA의 모델 결합방식을 활용하였다. 기본모델단위는 독립적인 수행단위로 표준적인 입력과 출력을 수행한다. 따라서 입력과 출력의 속성이 같은 기본모델단위는 결합할 수 있다. 본 연구에서 시범적으로 개발된 수자원통합모델링환경 WaterRing은 통합수자원관리의 실현에 있어 평가, 계획에 이용될 수 있다. 그러므로 향후 시스템의 개발이 완료되면 우리나라의 통합수자원관리의 실현을 위한 기반도구로서 많은 역할이 기대된다. 홍수기에 측정된 성과를 바탕으로 고수위대의 수위-유량관계 곡선식을 개발하여야 할 것으로 판단된다. 본 연구를 통해 일부 확인된 바와 같이, 일반적인 자연하천이 아닌 감조하천의 경우는, 각각의 수위대별 유량 값의 변화가 발생하는 바 기간별 혹은 간조와 만조부를 포함하여 유량측정을 하여야 할 것으로 판단된다. 청폐화담탕(淸肺化痰湯)은 LPS로 유도된 macrophage에서 NO와 염증Cytokine 생성량을 억제하였고 murine macrophage에서 NF-${\kappa}$B 활성을 억제함으로써 iNOS와 염증Cytokine 유전자 발현을 하향조절 하였다. 이러한 청폐화담탕(淸肺化痰湯)의 항염작용으로 천식, 기관지염, 폐렴, 결핵, 산후감모 등의 호흡기 질환에 응용할 수 있으리라 사료된다.im}$5개월), 9.44${\pm}$1.05 6${\sim}$ll개월)으로 개월에 관계없이 전반적으로 유사한 비율을 나타내었다. 분획물(첨가농도 15.6 ${\mu}$g/ml)은 60%의 저해효과를 나타내면서 농도 의존적으로 그 저해효과가 컸으며 250 ${\mu}$g/ml 농도에서는 80%의 저해효과를 관찰 할 수가 있었다. 에틸아세테이트분회물의 경우 디글로로메탄 분회물에 비해 다소 낮은 저해효과를 나타내었지만 250 ${\mu}$g/ml 농도에서 약 60%의 세포독성 효과를 나타내었다. 디클로로메탄 분획물과 에틸아세테이트 분획물에 의한 면역 활성 증진 효과를 검토한 결과, 디글로로메탄 분획물은 첨가농도 1 ${\mu}$g/ml에서 94%로 Yac-1표적세포를 사멸시켰으며 에틸아세테이트 분획물도 동일 농도에서 96%의 억제효과를 나타내었다. CTLL세포를 이용

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.63-64
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• 2008

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.361-363
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• 2001

Aromatic pelybenzoxazoles(PBOs) display excellent thermal stability plus good solvent and chemical resistance. Wholly aromatic PBOs, in fact, are soluble only in strong acids(e.g., sulfuric, rmethanesulfonic, triflic, and polyphosphoric acids). However, fully heterocyclized polymers have shown some drawbacks in solubility and processing. This problem of processing is currently being exploited to obtain unusual combinations of physical properties in fibers and films. (omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.494-502
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• 2009

A quantitative model was developed in order to estimate fishery production damage due to anthropogenically induced environmental changes. The model is described in the following equation, $Y_D=\frac{{\phi}_D}{{\phi}_G}[Y_0{\cdot}(t_p-t_0)-\frac{Y_0}{{\phi}_G}(1-e^{-{\phi}_G(t_p-t_0)})]$, where, $Y_D$ is annual amount of fishery production by nuclear power plant. ${\varphi}$ D and ${\varphi}$ G are instantaneous decreasing coefficient of fishery production by nuclear power plant and instantaneous decreasing coefficient of gross fishery production, respectively. $Y_0$ is annual mean fishery production without damages. $t_p$ is the present time, and $t_0$ is the starting time of damages. The model was applied to fishing grounds near a nuclear power plant on the east coast of Korea. Since fishery production damages have become bigger with increasing emission of thermal effluents from generators activities in the power plant, this factor has also been considered as, $\delta_{D_i}=\delta_D\({\sum}\limits_{i=0}^{n}\;W_i/W_T\)$, where, $\delta_{Di}$ is the cumulative damage rate in fishery production from generators, $\delta_D$ is the total cumulative damage rate in fishery production, $W_i$ is the emission amount of thermal effluents by generator i, and n is the number of generators in the nuclear power plant. This model can be used to conduct initial estimates of fishery production damages, before more detailed assessments are undertaken.

• Journal of Korea Foundry Society
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• v.12 no.1
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• pp.62-73
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• 1992

상변환시 수반되는 경계면에서의 잠열의 방출(또는 흡수)의 정확한 해석은 용접, 주조, 결정 생성, 일기 예보 등의 응용에 필수적인 것이다. 특히 주조의 경우 캐스팅 온도와 고체 용적분율의 관계를 앎으로서 잠열 방출의 해석이 가능하다. 본 연구는 상변환시 수반되는 잠열의 방출 형태를 4개의 다른 모델을 사용하여 비정상 온도분포, 용융형태, 자연대류가 미치는 영향을 수치적으로 구하였다. 2개의 서로 다른 물성치를 가진 합금을 선택하였는데 하나는 넓은 mushy 영역을 가진 알루미늄 합금이고 다른 하나는 좁은 mushy 영역을 가진 철금속계 합금이다. 알루미늄 합금의 경우 온도 분포와 시간에 따른 온도의 변화가 모델에 따라 상당한 차이가 있는 반면 철금속계 합금의 경우 상이한 모델일지라도 거의 차이가 없음을 알 수 있었다. 결론으로 용융시 정확한 온도 분포와 상변화 형태를 예측하기 위해서는, 알루미늄 합금(넓은 mushy 영역)의 경우 적절한 잠열 방출 모델의 채택이 필요 불가급한 것으로 사료된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.579-583
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• 2011

The component based propulsion modeling and simulation of an air-breathing engine such as ramjet and scramjet is studied. The simulation model has been realized considering the characteristics of the air-breathing engine which is composed of air intake, combustor and nozzle including engine controller and fuel supply system. To estimate the engine performance and to verify the engine controller, real time based Hardware in the Loop System simulating actual environment is constructed.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.451-459
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• 1999

Background : In sepsis, excessive generation of reactive oxygen species plays key roles in the pathogenesis of acute lung injury. The serum antioxidants such as catalase and MnSOD are elevated in sepsis and considered as predictors of acute respiratory distress syndrome(ARDS) and prognostic factors of sepsis. Peroxiredoxin(Prx) has recently been known as an unique and major intracellular antioxidant. In this study, we evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells(RAW 267.7) after treatment of oxidative stress and endotoxin and measured the amount of Prx I, Prx II and thioredoxin(Trx) in peritoneal and bronchoalveolar lavage fluid of septic animal model. Methods : Using immunoblot analysis with specific antibodies against Prx I, Prx II and Trx, we evaluated the distribution of Prx I and Prx II in human neutrophil, alveolar macrophage and red blood cell. We evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide(LPS) and measured the amount of Prx I, Prx II and Trx in peritoneal lavage fluid of intraperitoneal septic animals(septic animal model induced with intraperitoneal 6 mg/Kg LPS injection) and those in bronchoalveolar lavage fluid of intraperitoneal septic animals and intravenous septic animals(septic animal model induced with intravenous 5 mg/Kg LPS injection) and compared with the severity of lung inflammation. Results : The distribution of Prx I and Prx II were so different among human neutrophil, alveolar macrophage and red blood cell. The expression of Prx I in mouse monocyte-macrophage cells was increased after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide but that of Prx II was not increased. The amount of Prx I, Prx II and Trx were increased in peritoneal lavage fluid of intraperitoneal septic animals but were not increased in bronchoalveolar lavage fluid of intraperitoneal and intravenous septic animals regardless of the severity of lung inflammation. Conclusion : As intracellular antioxidant, the expression of Prx I is increased in mouse monocyte-macrophage cells after treatment of oxidative stress and endotoxin. The amount of Prx I, Prx II and Trx are increased in local inflammatory site but not increased in injured lung of septic animal model.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.509-521
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• 1994

This study is an effort to develop computer simulation model that produce precipitation patterns from stochastic model. A stochastic model is formulated for the process of daily precipitation with considering the sequences of wet and dry days and the precipitation amounts on wet days. This study consists of 2 papers and the process of precipitation occurrence is modelled by an alternate renewal process (ARP) in paper (I). In the ARP model for the precipitation occurrence, four discrete distributions, used to fit the wet and dry spells, were as follows; truncated binomial distribution (TBD), truncated Poisson distribution (TPD), truncated negative binomial distribution (TNBD), logarithmic series distribution (LSD). In companion paper (II) the process of occurrence is developed by Markov chain. The amounts of precipitation, given that precipitation has occurred, are described by a Gamma. Pearson Type-III, Extremal Type-III, and 3 parameter Weibull distribution. Daily precipitation series model consists of two models, A-Wand A-G model, by combining the process of precipitation occurrence and a continuous probability distribution on the precipitation of wet days. To evaluate the performance of the simulation model, output from the model was compared with historical data of 7 stations in the Nakdong and Seomjin river basin. The results of paper (1) show that it is possible to design a model for the synthetic generation of IX)int precipitation patterns.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.2
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• pp.145-153
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• 1984

In the present work, a computer simulation is performed employing Hottel-Whillier-Bliss model for thermal performance of solar collectors. The major collector parameters examined in the computer simulation are: number of transparent glass covers(N), thermal emissivity of the absorbing plate surface (.epsilon.$_{P}$), absorptivity of absorber plate (.alpha.$_{p}$), flow rate per unit area of collector (G), $L_{b}$ / $k_{b}$ of insulation material, tilt angle of collector (S), and solar insolation(I). By varying numerical values of the major collector parameters around their typical values, the corresponding variations in thermal efficiency curves are examined. In addition, an experimental investigation has been carried out with a slightly modified KAIST collector test loop under a real sun condition in order to compare with the simulation results, examine the applicability of the mathematical model of the collector thermal performance, and study the effect of variation of flow rate (G) on thermal efficiency and the range of optimum flow rate.e.