• 한국자동차공학회논문집
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• 제7권5호
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• pp.107-120
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• 1999

Catalytic converters are the most fascinating and complicated chemical reactors. They are most often operated in the transient state with respect to composition, flow rate, temperature, etc. The mathermatical model developed in this work accounts for simultaneous heat and mass transfer, chemical reaction, and multi dimensional flow characteristics to analyze the light-off performance of monolithic catalytic converter with comparable mass flow rate. To validate the mathematical model, comparison between experimental and numerical results has been performed. The numerical results show a good agreement with experimental data. It is forund that inflow rate shows major effect on the characteristics of termal response of catalytic converter.

• 노동경제논집
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• 제27권3호
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• pp.25-52
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• 2004

1998~2000년에 신규로 장해등급이 판정된 남성 산재근로자를 대상으로하여 산재보상 수급자 데이터베이스와 고용보험 피보험자 데이터베이스를 결합함으로써 취업력(labor history)을 재구성하였다. 이 자료에 기초한 분석 결과에 따르면, 먼저 원직장복귀가 산재근로자의 주요한 직장복귀 경로이며 고용유지에도 유효하였던 반면, 요양종결 이후의 취업자들은 상대적으로 높은 이직률을 보였다. 그리고 직장복귀자의 약 6할은 이직을 경험하는 것으로 나타났으며, 이직자 가운데 77%는 이전 직장의 취업기간이 1년 미만이었다. 한편 다중위험모형을 이용한 취업기간 분석에서 사업장 규모가 작을수록 그리고 비자발적 이직의 경우에는 직업탐색기간이 길수록 산재근로자의 취업기간이 짧아진다는 사실을 확인하였다. 뿐만 아니라 요양종결 이후의 첫 직장에서 일자리를 유지하는 기간이 길수록 이후의 취업과 고용유지에도 긍정적인 효과를 보였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.418-421
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• 2000

A model was developed to describe the microbial decontamination of diesel contaminated soil in a soil column. The biodegradation rate of diesel in nature depends on temperature and the pH of soil, availability of nutrients, oxygen and water. The soil moisture content is one of the essential factors because it characterizes the availability not only of water to microorganisms but also of oxygen and nutrient dissolved in soil. In this work, the rate of biodegradation was modeled by coupling Michaelis-Menten kinetics for the aqueous-phase solute with adsoption-desoption equation for diesel sorption and desorption from soil.

• 대한인간공학회지
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• 제2권2호
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• pp.3-10
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• 1983

While three subjects were running on treadmill at five different speeds, their heart beat interval times were measured and analyzed. From the analysis, we discovered some relation- ships between workload and cardiac response, especially cardiac arrhythmia. Using these relationships, a physioligical model for estimating workload was developed. Although pulse rate has been considered as a good measure of physical load, this study shows that it is highly subject dependent and therefore unsuitable for task evalution. It is recommended to use range of heart beat interval times rather than pulse rate in the evaluation of light work.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.972-975
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• 2013

This work developed a code analysis & extraction tool named Function Network Analyzer (FNA) to reduce the cost of software safety analysis. FNA analyzes functions and variables which a given function depends on, and extracts subset of code that can be compiled of automotive operating system, final resulting a well-ordered code sequence that can be compiled for model checking technique. And the experimental result illustrates that FNA can get 100% accurate rate and over 96% reduction rate by testing API functions from trampoline system.

• Journal of Forest and Environmental Science
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• 제32권3호
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• pp.253-261
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• 2016

Xanthoceras sorbifolia seed coat (XSSC) is a processing residue of the bioenergy crop. This work aimed to evaluate the applicability of using the steam explosion to modify the residue for dye biosorption from aqueous solutions by using methylene blue as a model cationic dye. Equilibrium, kinetic and thermodynamic parameters for the biosorption of methylene blue on the steam-exploded XSSC (SE-XSSC) were evaluated. The kinetic data followed the pseudo-second-order model, and the rate-limiting step was the chemical adsorption. Intraparticle diffusion was one of the rate-controlling factors. The equilibrium data agreed well with the Langmuir isotherm, and the biosorption was favorable. The steam-explosion pretreatment strongly affected the biosorption in some respects. It reduced the adsorption rate constant and the initial sorption rate of the pseudo-second-order model. It enhanced the adsorption capacity of methylene blue at higher temperatures while reduced the capacity at lower ones. It changed the biosorption from an exothermic process driven by both the enthalpy and the entropy to an endothermic one driven by entropy only. It increased the surface area and decreased the pH point of zero charge of the biomass. Compared with the native XSSC, SE-XSSC is preferable to MB biosorption from warmer dye effluents.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.89-92
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• 2004

This work describes a model development and numerical simulation of detailed combustion mechanisms of RDX/GAP/BTIN propellants. The analysis is based on the conservation equations of mass, energy, and species concentrations for both the condensed and gas phases, and takes into account finite-rate chemical kinetics and variable thermophysical properties. The model has been applied to study the combustion wave structures and burning characteristics of RDX/GAP/BTIN propellants over a broad range of pressures. Reasonably good agreement is achieved between the calculated and measured burning rate at atmospheric pressure. But the model calculation does not result in dark zone experimentally observed.

• 한국사회복지학
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• 제58권2호
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• pp.223-249
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• 2006

본 연구는 남성 돌봄 노동참여 지원정책을 통해 경제협력개발기구 국가들을 유형화함으로써 세 가지 주목할 만한 결과를 도출하였다. 첫째, 남성 돌봄 노동참여 정책의 지원수준과 전통적 주 생계부양자 모형의 강도를 통해 OECD 15개국을 5개의 유형으로 구분하였다. 이러한 유형화는 탈상품화를 중심으로 복지체제를 유명화한 주류 복지국가의 분석과 달리 남성의 노동력의 가족화와 탈상품화를 준거로 분석했을 때 새로운 유형화의 가능성을 제시하였다는 점이다. 둘째, 합계출산율, 여성의 경제활동 참가율 지표에서 남성의 돌봄 노동참여 지원 수준이 높고, 전통적 주 생계부양자가구의 비율이 낮은 국가군일수록 합계출산율과 여성의 경제활동 참가율이 높은 것으로 나타났다. 셋째, 한국의 남성에 대한 돌봄 노동참여 지원 정책의 수준은 OECD 국가 중 가장 낮은 것으로 나타났다. 이러한 돌봄 노동에 대한 낮은 수준의 성간 공유가 결국 한국 여성의 낮은 경제활동 참가율, 저출산 현상을 설명하는 하나의 주요한 요인이 될 수 있다는 것이다.

• 소성∙가공
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• 제17권3호
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• pp.161-169
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• 2008

In the present work, the two-back stress model is proposed and continuum damage mechanics (CDM) is incorporated into the plastic constitutive relation in order to describe the plastic deformation localization and the damage evolution in a deforming continuum body. Coupling between damage mechanics and isothermal rate independent plasticity is performed using the kinematic hardening rule, which in turn is formulated by combining the nonlinear Armstrong-Frederick rule and the Phillips rule. The numerical analyses are carried out within h deformation theory. It is noted that the damage evolution within a work piece accelerates the plastic deformation localization such that the material with lower hardening exponent results in a rapid shear band formation. Moreover, the results from the numerical analysis reflected closely with the micro-structures around the fractured regime. The effects of the various hardening parameters on deformation localization are also investigated. As the nonlinear strain rate description in the back stress evolution becomes dominant, the strain localization becomes intensified as well as the damage evolution.

• 한국압력기기공학회 논문집
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• 제12권2호
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• pp.40-49
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• 2016

Flow accelerated corrosion (FAC) of the carbon steel piping has been a significant problem in nuclear power plants. FAC occurs under certain hydrodynamic, environmental, and material conditions, and extensive research into the factors of FAC has been conducted. The basic process of FAC is now relatively well understood; however, a full mechanistic model has not yet been established. Recently, the Korea Atomic Energy Research Institute (KAERI) has built a large experiment loop system for FAC. To produce significant experimental results using this system, the factors affecting on FAC should be analyzed quantitatively, and a model needs to be developed. In this work, a statistical modeling methodology to develop an empirical model is described in detail, and a preliminary model is suggested. Firstly, FAC data were collected from the research literature in Japan and the results of domestic experiments. The flow rate, water temperature, pH at room temperature, and the Cr content are selected as major factors, and nonlinear regression is used to find the best fit of the available data. An iterative procedure between suggesting and evaluating a model is used until an optimum model is obtained. The developed model gives the FAC rate comparable to the measured FAC rate. The developed model is going to be refined using additional laboratory data in the future.