• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.689-695
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• 2015

A biofilm filtration for the removal of gaseous pollutants has been recognized as a process with a complex interaction between the gas flow characteristics and the process operating variables. This study aims to develop an one dimensional dynamic numerical model which can be utilized as a tool for the analysis of biofilm filtration process operated in plug flow mode. Since, in a plug flow system, minor environmental changes in a gaseous unit process cause a drastic change in reaction and the interaction between the pollutants is an influencing factor, plug flow system was generalized in developing the model. For facilitation of the model development, dispersion was simplified based on the principles of material balance. Several reactions such as competition, escalation, and control between the pollutants were included in the model. The applicability of the developed model was evaluated by taking the calibration and verification steps on the experimental data performed for the removal of BTX at both low and high flow concentration. The model demonstrated a correlation coefficient ($R^2$) greater than 0.79 under all the experimental conditions except for the case of toluene at high flow condition, which suggested that this model could be used for the generalized gaseous biofilm plug flow filtration system. In addition, this model could be a useful tool in analyzing the design parameters and evaluating process efficiency of the experiments with substantial amount of complexity and diversity.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.44-49
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• 2023

이 연구는 MBTI 심리기능을 근거로 사용자 유형을 ST와 NF로 구분하고, 그룹별로 나눈 일상대화를 전사 후 분석하여 대화에서 나타나는 청자의 공감적 반응이 성향에 따라 차별화되는 점을 발견하고 이를 챗봇 대화 실험에 적용하여 분석결과의 유효성을 귀납적으로 증명하였다. 고성능의 초대규모 생성모델을 필두로 한 채팅 에어전트 구현이 보편화된 시점에서 진정 가치있는 대화 모델은 유창한 언어 구사 능력뿐만 아니라 사용자의 성향에 적합한 만족스러운 대화 경험을 제공할 수 있어야 함을 시사한다. 이 연구는 리얼월드의 대화 방식을 모방하여 챗봇 대화로 재현하였다는 점에서 실질적인 B2C 대화 서비스의 질적 향상에 기여도가 높을 것으로 기대된다.

• Journal of the Korean Institute of Gas
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• v.15 no.3
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• pp.39-46
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• 2011

This study investigates the effects of the DME and n-Butane mixture and of the stratification on combustion characteristics of HCCI engine by chemical reaction calculation. First, the existing DME reaction scheme and n-Butane is combined to make new chemical reaction model, then validating the effectiveness of new scheme. Furthermore, this study verify the HCCI combustion characteristics according to the changes of DME and n-Butane mixture ratio, which shows different auto ignition characteristics. Finally, it confirms the effects of stratification of mixture fuel on the reduction of pressure rise rate.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.424-425
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• 1999

오존은 대기 중에 있는 질소산화물 (NO$_{x}$)과 휘발성 유기화합물 (Volatile Organic Compounds, VOCs)이 강한 햇빛과 반응하여 생성되는 2차 오염물질이다. 오존의 농도는 오염물질의 배출과 기상조건, 그리고 대기 중 화학반응이 상호 연결되어 나타난다. 다양한 변수들이 오존 농도 상승에 영향을 미치며, 이러한 과정을 유기적으로 이해하기 위하여 다양한 광화학 수치 모델들이 사용되고 있다.(중략)

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.80-85
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• 2006

현재 많은 인터넷 콘텐츠 서비스가 다양한 방식의 유료 서비스로 제공되고 있지만 다양하고 복잡한 콘텐츠 서비스의 특성상 가격 책정에는 많은 어려움이 있다. 본 연구는 인터넷 영화관을 대상으로 하여 사용자들이 서비스를 선택할 때 가장 고려하는 속성을 분석하고 속성과 속성 수준을 설정한 프로파일들의 가격반응함수를 구하였다. 또한, 선형${\cdot}$곱셈${\cdot}$유인${\cdot}$구텐베르그 모델 중 가장 적합한 모델을 추정하고 독점 영역과의 관계를 살펴봄으로써 각 기업들이 서비스의 가격을 책정함에 있어서 가장 수익성 높고 적합한 전략을 설정할 수 있도록 방향을 제시하였다.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.151-157
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• 2005

A one-dimensional numerical model was developed to simulate vertical profiles of electron acceptors and their reduced species in benthic sediments. The model accounted for microbial degradation of organic matter and subsequent chemical reactions of interest using stoichiometric relationships. Depending on the dominant electron acceptors utilized by microorganisms, the benthic sediments were assumed to be vertically subdivided into six zones: (1) aerobic respiration, (2) denitrification, (3) manganese reduction, (4) iron reduction, (5) sulfate reduction, and (6) methanogenesis. The utilizations of electron acceptors in the biologically mediated oxidation of organic matter were represented by Monod-type expression. The mass balance equations formulated for the reactive transport of organic matter, electron acceptors, and their corresponding reduced species in the sediments were solved utilizing an iterative multistep numerical method. The ability of model to simulate a freshwater sediments system was tested by comparing simulation results against published data obtained from lake sediments. The simulation results reasonably agreed with field measurements for most species, except for ammonia. This result showed that the C/N ratio (106/16) in the sediments is lower than what the Redfield formula prescribes. Since accurate estimates of vertical profiles of electron acceptors and their reduced species are important to determine the mobility and bioavailability of trace metals in the sediments, the model has potential application to assess the stability of selected trace metals in the sediments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.26-32
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• 2005

In this paper, the effect of various regression models is investigated on structural optimization using the central composite method. Three bar truss and the upper platform of a satellite are optimized using various regression models that are polynomial, exponential and log functions. Response surface method is non-gradient, semi-global, discrete and fast converging in optimization problem. Sampling points are extracted by the design of experiments using the central composite method. Response surface is generated using the various regression functions. Structural analysis for calculating constraints is executed to find static and dynamic responses. From this study, it is verified that the response surface method has advantage in optimum value and computation time in comparison to other optimization methods.

• Journal of the Korean Vacuum Society
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• v.3 no.4
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• pp.414-419
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• 1994

Surface of Pt/$Al_2O_3$ model catalyst was produced on an aluminum foil with surface area of 1 $cm^2$ The aluminum surface was oxidized under $10 ^5Torr$Torr oxygen and platinum was deposited on top of the oxide layer using a plasma evaporation source. Conversion of I-butene was performed on the model catalyst surface. Isomerization was the major reaction in I-butene conversion on the aluminum oxide layer. Addition of Pt on the aluminum oxide layer induces hydrogenation of I-butene. Selectivity for the hydrogenation increases as the amount of Pt on alumina increases.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.670-672
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• 2023

본 논문에서는 소셜 미디어 약물 리뷰 데이터로부터 약물 이상 반응을 탐지하는 모델인 FC-BERT 를 기반으로 소셜 네트워크 분석을 활용하여 웹 애플리케이션을 구현하였다. FC-BERT 모델을 거쳐 나온 개체명 인식 결과 중에 같은 의미를 가진 서로 다른 약물 이상 반응 표현들을 MedDRA 부작용 사전을 참고하여 하나의 MedDRA 용어로 표준화하여 매핑했다. 해당 결과에 소셜 네트워크 분석 기법을 적용하여 생성한 상위 15 개의 ADR 동시 출현 그래프를 상위 30 개의 워드 클라우드와 함께 시각화하여 보여주는 웹 애플리케이션을 개발했다. 동시 출현 그래프는 가장 많은 리뷰에서 동시에 나타나는 ADR 쌍을 보여준다. 본 논문에서 제안한 웹 애플리케이션은 사람마다 다르게 나타나는 다양한 약물 이상 반응을 사용자에게 좀 더 접근성이 좋게 제공할 수 있을 것으로 보인다.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.332-336
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• 2010

Ionic liquid immobilized on mesoporous amorphous silica was prepared from the coupling of 1-(triethoxysilylpropyl)-3-n-alkyl-imidzolium halides with tetraethyl orthosilicate(TEOS) through template-free condensation under strong acidic conditions. The immobilized 1-n-butyl-3-methyl imidazolium bromide ionic liquid on amorphous silica(BMImBr-AS) was proved to be an effective heterogeneous catalyst for the synthesis of dimethyl carbonate(DMC) from transesterification of ethylene carbonate(EC) with methanol. High temperature, high carbon dioxide pressure and long reaction time were favorable for the reactivity of BMImBr-AS. Kinetic studies based on two step reactions revealed that the proposed reaction model fitted well the experimental data. The apparent activation energy was estimated to be 67.4 kJ/mol.