• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.1 s.244
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• pp.48-56
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• 2006

We investigated gas residence time and mixing characteristics due to various swirl numbers generated by normal injection of secondary air to a lab-scale cylinderical combustor. The residence time was estimated by measuring the temporal pressure difference which was caused by deposition of test particles on a filter media after the injection by a syringe. The mixing characteristics were evaluated by standard deviation value of test gas concentration at different measuring points. The test gas concentration was detected by a gas analyzer. The swirl number of $20{\sim}30$ for ${\theta}=5^{\circ}$ caused long residence time enough to improve mixing characteristics. Numerical calculations were also carried out to understand physical meanings of the experimental results.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2284-2291
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• 2006

The present study investigates gas residence time and mixing characteristics for various swirl numbers generated by injection of secondary air into a lab-scale cylindrical combustor. Fine dust particles and butane gas were injected into the test chamber to study the gas residence time and mixing characteristics, respectively. The mixing characteristics were evaluated by standard deviation value of trace gas concentration at different measurement points. The measurement points were located 25 mm above the secondary air injection position. The trace gas concentration was detected by a gas analyzer. The gas residence time was estimated by measuring the temporal pressure difference across a filter media where the particles were captured. The swirl number of 20 for secondary air injection angle of 5$^{\circ}$ gave the best condition: long gas residence time and good mixing performance. Numerical calculations were also carried out to study the physical meanings of the experimental results, which showed good agreement with numerical results.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.480-488
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• 2021

The term residence time is defined as the time taken for substances in a system to leave the system and is a useful concept to explain the physical environment characteristics of a coastal area. It is important to know the spatial characteristics of the residence time to understand the behavioral properties of pollutants generated in a marine system. In this study, the spatial distribution of average residence time was calculated for Gangjin Bay, Korea, using a hydrodynamic model including a particle tracking module. The results showed that the average residence time was about 10 days at the surface layer and about 20 days at the bottom layer. Spatially, this was the longest residence time in the southwestern sea. There was no significant difference in average residence time at the surface layer due to freshwater discharge, but spatial variation at the bottom layer was larger. The average residence time at the bottom layer decreased in the southwestern area due to freshwater discharge and increased in the northern area. This result suggests that the residence time of anthropogenic pollutants may have a large spatial difference depending on the freshwater discharge, and thus the time taken to influence cultured organisms may also vary.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.1
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• pp.17-26
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• 2014

This study examined the trend of floor space characteristics, size characteristics and modeling characteristics so as to evaluate the satisfactory level of subjects living in Hanok. By doing so, the type of Hanok was classified into 5 groups. The satisfactory level was evaluated after the subjects resided in Hanok based on each type of housing. In the satisfactory level investigation, which was conducted after the residence, the overall satisfactory level on Hanok showed to be high. In the evaluation on the residence scale, positive results were generally achieved regarding 'full size of residence', 'number of rooms compared to residence size', 'size of living room', etc. The indoor environment of residence evaluation mainly showed positive results regarding 'ventilation', but most subjects were unsatisfied in regard to 'heating', 'noise', 'lighting', etc. In the behavioral factor evaluation of residents, positive results were gained regarding 'health', but comparatively negative results showed based on items of 'construction expense', 'burden of maintenance expense', 'investment value', etc. After analyzing the influential factors on the overall satisfactory level, results showed that 'dust inflow' of the physical site environment evaluation, 'size of living room' of the residence size evaluation, 'heating' of the residence indoor environment evaluation, and 'burden of maintenance expense' in the behavioral factor evaluation significantly influences the overall satisfactory level.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.5
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• pp.416-424
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• 2007

In adsorption/catalytic process, numerical analysis has been performed to identify the flow characteristics of flue gas in the cyclone and to estimate the residence time of activated carbon using Computational Fluid Dynamics (CFD) technique. To consider flue gas and activated carbon particles simultaneously, Euler-Lagrangian model was employed so that residence time could be obtained from the numerical analysis directly. The numerical analysis has been performed with different three particle sizes and compared each flow characteristics with particle’ size. Fundamental flow patterns of flue gas and activated carbon particles, pressure distribution, residence time of flue gas, and activated carbon particles and distribution of activated carbon have been obtained from the numerical analysis.

• Journal of Korean Public Health Nursing
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• v.23 no.2
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• pp.219-231
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• 2009

Purpose: This study compared health behaviors between single-member and multiple-member households by gender in adults. Method: Study subjects were 21,757 adults 20-65-years-of-age from the Third Korea National Health and Nutrition Examination Survey in 2005. The relationship between health behaviors and residence characteristics was assessed using multiple logistic regression analysis while controlling for sociodemographic characteristics. Results: Younger women living alone were more likely to drink than older women living with others. Women who were in multiple-member households and had a low income were less likely to exercise regularly, to sleep well, and to have regular health examinations. Age, educational level, and income were significantly associated with smoking, exercise, and health examination rather than residence characteristics in men. Conclusion: Residence characteristics should be considered in developing a public health program to reduce or increase modifiable health behaviors as well as age, gender, education, and income.

• Korean Journal of Computational Design and Engineering
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• v.18 no.1
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• pp.10-20
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• 2013

The Yoon Jeung residence is a well-known and prototypical aristocratic house example showing typical and interesting characteristics of the traditional houses in the middle region of Korea. When it comes to understanding the architectonic characteristics of a Korean traditional house, it was not easy to actually capture the compositional and/or constructional knowledge of the building even though it is a wooden building with many wooden members showing their compositional relations. Now with the help of the BIM tool, the Building Information Modeling tool, we could actually be able to compare and analyze each member and their compositional relations. In this paper we examine the unique traditional composition method used in extending the building's structural sections utilizing the bended-joint characteristics of traditional buildings with exemplar case of the Yoon Jeung residence. Thereby we examine those relationships among three major compositional parts namely the plan based spatial compositions, the upper wooden compositions and the roof forms so as to specify the building's typical characteristics with reasonably acceptable causes. The inner and outer block of the residence are handled with their bended-joints with more detailed knowledge of categorization by way of joint relationships among members.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.4
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• pp.475-486
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• 2000

The purpose of this research were to identify the differences in clothing behaviors and psychological characteristics ill relation to age and residence and to identify the relative effects of Korean female adolescent's psychological characteristics on the clothing behaviors. The instruments measuring 9 psychological characteristics-adolescent egocentrism, social and general self-efficacy, public and private self-consciousness, boredom susceptibility, optimal stimulation level, body attitudes-were adapted from previous studies. Clothing behavior measurements were developed based on the pilot study results or adapted from previous studies. The data. collected from 2284 nationwide sample of Korean female adolescents(early, middle, late) was analyzed by frequency, two-way ANOVA, and LISREL confirmatory factor analysis. Clothing behavior were factor analyzed and 6 factors were identified: dressing for others. conformity to peers, clothing interest, self-expression, psychological dependence and clothing exhibition. Effects of age were dominant in 6 out of 9 psychological characteristics and five clothing behavior factors except conformity to peers. Dominant main effect of residence was found oかy in boredom susceptibility. From the results of LISREL, adolescent egocentrism, public self-consciousness and sensation seeking tendency were found to be the most influential psychological characteristics of female adolescents'clothing behaviors.

• Journal of Environmental Science International
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• v.29 no.3
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• pp.273-282
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• 2020

Residence time is defined as the time taken for a material in a system to leave the system. The residence time characteristics in shellfish aquaculture determine the dispersion of excretion from aquaculture farms, along with the supply of food by seawater exchange. In this study, we estimated the spatial distribution of average residence time in the shellfish farming area using a particle tracking model. As a result, a relatively short average residence time of about 20 days or less was calculated in most areas, but an average residence time of more than 40 days was calculated in the inner areas. Relatively long average residence times were calculated along the west coast compared to the east coast, with the longest average residence time of more than 50 days in the northwestern areas. It can be inferred that the disturbance of the benthic ecosystem caused by shellfish farms is likely to be large because of the relatively weak dispersion of excrement from shellfish farms located on the west coast, especially in the northwest region. This distribution of average residence time is important for understanding the potential effects of seawater exchange on the environmental sustainability of shellfish farms, along with the seawater circulation characteristics of Jaran Bay.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.203-213
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• 2007

Numerical analysis has been performed to understand flow characteristics in the reactor with bag filters in an integrated adsorption/catalytic process which can treat dioxin and $NO_{x}$ together. Computational fluid dynamics technique was employed with Euler-Lagrangian model to consider flue gas and activated carbon particles simultaneously, so that residence time of flue gas and activated carbon particle could be obtained from the numerical analysis directly. The numerical analysis has been performed with different three particle sizes and compared each flow characteristics with particle's size. Fundamental flow patterns of flue gas and activated carbon particles, pressure distribution, residence time of flue gas and activated carbon particles, and distribution of activated carbon have been obtained from the numerical analysis. Flow patterns of flue gas and activated carbon particles in the reactor were very complicated and they moved along very various paths. Therefore, their residence time in the reactor was also various. The results obtained would be effectively used to estimate the removal efficiency in the reactor once the residence time is combined with the reaction equation.