• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.117-125
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• 2003

Experimental and theoretical works were performed for the separation of large polyelectrolyte, such as DNA, in a column packed with gel particles under the influence of an electric field. Since DNA quickly orient in the field direction through the pores, this paper presents how intraparticle convection affects the residence time distribution of DNAs in the column. The concept is further illustrated with examples from solid -liquid systems, for example, from chromatography Showing how the column efficiency is improved by the use of a n electric field. Dimensionless transient mass balance equations were derived, taking into consideration both diffusion and electrophoretic convection. The separation criteria are theoretically studied using two different Peclet numbers in the fluid and solid phases. These criteria were experimentally verified using two different DNAs via electrophoretic mobility measurements. which showed how the separation position of the DNAs varies in the column in relation to the Peg/Pef values of an individual DNA. The residence time distribution was solved by an operator theory and the characteristic method to yield the column response.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.196-201
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• 2006

Silica(SiO2) nanoparticles are used as additives in plastics and rubbers to improve mechanical, electrical, magnetic properties and optical material. Silica nanoparticles were synthesized by the gas phase thermal oxidation of several kinds of precursors in many types of reactor. Diffusion flame reactor has some advantages compared with other types of reactors. In this study, we investigated the generation of silica nanoparticles on the effect of residence time by tetraethylothosilicate(TEOS) in a turbulent diffusion flame reactor controlled by providing reactant flowrate and reactor geometry affect particle morphology, particle size and particle size distribution. To determine the flame residence time, flame length should be determined which was examined by ICCD image. Particle size, distribution and morphology were performed with TEM.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.377-381
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• 2006

The purpose of this study was to suggest the improvement plan for IAQ of the combined officetel and residence through analyzing demands, satisfaction, subjective symptoms and device of residents. For this study, the data was collected from 110 residents by questionnaire survey and an experienced planner by interview. The result showed that the IAQ improvement of the combined officetel and residence was urgent. The educational program about maintenance of IAQ for residents was essentially needed. To recommend eco-friendly materials in process of construction wasimportant so as to take precaution against ‘sick building syndrome'. It was also necessary to improve on the size and shape of ventilation window.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.426-431
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• 2006

Townhouse takes both private housings' and apartments' strengths as its own and forms a new style of house planning. It is highly convenient in maintenance and complement, also satisfying the residents with its independence and refundability. Currently, metropolitan area in Korea being the ignition of the townhouse planning, the gradual housing site development in metropolitan area is laying a foundation for further developments throughout Korea. Through amendment of legislation and qualitative upgrade of habitat, standard about new residence should be readied for activating of townhouse in korea. Therefore This research examines several residence types to secure diversification of residence type and good quality of residence place, introduce the townhouse that developed fast in internal recently and make a planed option for activating in korea.

• 음성과학
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• 제14권1호
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• pp.105-119
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• 2007

The purpose of this study is to examine Korean students' production and perception of word-final stop voicing in light of their overseas experience. Subjects were English native speakers, Korean university students with residence experience in America, Korean university students without residence experience in America, and Korean elementary school students. They participated in both production and perception tests. Results showed that the students' production and perception with residence experience in America appeared quite similar to those of the English native speakers. In the production tests, we noticed somewhat different results in temporal and frequency features. The one-year residence in America had some influence on their frequency features, but not the temporal features in the word final stop production. That difference could be seen in the perception tests, too. We could not find any difference in the identification test of the final release environment between the Korean university students who had studied abroad and those who didn't. Rather the difference could be found in the cue influence test in both the final release and non-release environments.

• 한국주거학회논문집
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• 제15권4호
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• pp.75-86
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• 2004

This research is about the Korean private residence as the actual housing published in Kuchie, 'Chosun and Architecture'. Research about the Korean private residence during the Japanese colonial period is important to find out the influence of foreign culture on Korean housing during that period. This research is necessary to reveal the tendency of modernization of Korean housing and how the foreign cultural relationship transformed and applied to the Korean housing. This research was carried out mainly on the 16 Korean private residences published in 'Chosun and Architecture'. The main subject of this research is to analyze the architectural floor plan, building material and heating facilities etc. Other important themes of the research are the practical side of actual housing plan, interior furnitures and fittings, electrical fittings and the classification of life style.

• 한국세라믹학회지
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• 제33권8호
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• pp.935-941
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• 1996

Two-dimensional carbon/carbon preforms made of PAN-based carbon yarn and phenolic resin were densified with pyrolysis of propane by pulse chemical vapor infiltration where repeated the cycle of gas introduction residence and evacuation. Maximim density increment was 14% when infiltration temperature and time were 100$0^{\circ}C$ and 21.25 hrs respectively. The distribution of deposits of pyrocarbon by this process has been occurred uniformly in the bottom middle and top of carbon/carbon composite preform Pulse CVI with residence is most effective in increasing density and shortening infiltration time among isothermal CVI and pulse CVI with and without residence.

• 한국주거학회논문집
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• 제20권3호
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• pp.27-36
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• 2009

A person's residence is the primary environment which affects physical and emotional-gratification. Residential environments are very important to a person's quality of life. Because the age of society has rapidly increased, we must take a profound interest in the welfare and residences of the aged. While the government has begun to prepare for an aging society, the residential environments of the aged has not been fully considered. Because the welfare of the aged begins in the house, the term 'residence for the aged' is not limited to the physical space. Because residences for the old aged are included in various social policies such as family relations, social security, health care, safety etc, relevant policies for these residences must be prepared as rapidly as possible. This study-focused on both the importance of residences for the aged and the residential desires of the aged, and aims to propose planning criteria for the residences of the aged.

• Korea-Australia Rheology Journal
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• 제18권3호
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• pp.143-151
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• 2006

We analyzed the non-Newtonian and non-isothermal flow in a single screw extruder system and investigated the mixing performance with respect to the screw speed and the screw pitch. The viscosity of polymer melt was described with Carreau-Yasuda model. The mixing performance was computed numerically by tracking the motions of particles in the screw element system. The extent of mixing was characterized in terms of the deformation rate, the residence time distribution, and the strain. The results revealed that the high screw speed reduces the residence time but increases the deformation rate while the small screw pitch increases the residence time. It is concluded that the high screw speed increases the dispersive mixing performance and the small screw pitch increases the distributive mixing performance.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.421-428
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• 2011

We conducted modeling experiments to evaluate the residence times and exchange rates of seawater in Gamak Bay, located on the southern coast of the Korean Peninsula. The results revealed that pollutants are more quickly dispersed in a fixed grid rather than in a variable grid system. Pollutant concentrations decayed exponentially with time after release near the mouth of the bay, whereas no exponential variations were seen at the northwest end of the bay. The mean exchange rate of the seawater was 1.58% per day in the variable grid system, and the residence time of pollutants was greater than 288 days in Gamak Bay. Conversely, the exchange rate of seawater in Gamak Bay, as revealed by the particle tracking method, was 65% over a 50-day simulation. The results suggest that the seawater exchange in Gamak Bay is so low that pollutants are likely to remain in the bay indefinitely.