• Biotechnology and Bioprocess Engineering:BBE
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• 제4권1호
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• pp.36-40
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• 1999

Optimal lyophilization process was developed for manufacturing the dried product of Lactobacillus acidophilus with high cell viability. Three major factors, freezing rate, specific surface area of samples, and stabilizer type and their synergy were shown to play a crucial role in the development of an effective lyophilization process. Finally we found an optimal combination among three process parameters mentioned above; an exceptionally high cell survival percentage of 90% was achieved using the 8.28 cm-1 specific surface area of samples, slow freezing rate, and a stabilizer composition of 4% skim milk +1% glycerol +0.1% calcium chloride.

• 국제지역연구
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• 제13권3호
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• pp.309-330
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• 2009

본 연구는 실질환율변동이 경기변동에 미치는 효과를 한국과 일본에 대하여 비교분석하는데 목적을 두고 있다. 기존의 실증분석에 의하면 신흥경제국의 경우 실질환율의 상승이 경기수축효과를 가져올 수 있는 반면 선진국의 경우 경기확장효과를 가질 수 있다는 연구결과가 많다. 한국은 신흥경제국의 사례로, 일본은 선진국의 사례로 각각 선택하여 기존의 연구결과와 비교하고자 한다. 구조VAR(S-VAR)모형을 사용하여 실질금리, 실질성장률, 실질환율, 국제유가, 인플레이션율 등 5개변수의 1980년 1/4분기부터 2006년 4/4분기까지의 분기데이터에 대해 충격반응함수와 분산분해를 통해 실질환율변동의 경기변동효과를 분석하고 있다. 본 연구는 한국의 경우 실질환율의 상승이 경기수축적인 반면 일본의 경우는 반대로 경기팽창적이라는 기존의 연구결과를 다시 확인하고 있다.

• 환경위생공학
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• 제2권2호
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• pp.49-60
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• 1987

The incidence of Sexually Transmitted Disease has risen despite the progress in its diagnosis and treatment methods. For the effective control programs of S.T.D it should be required medical and social approaches. This survey was conducted in Young Dung Po and Sung Buk areas from June, 1986 to September, 1986. The 1185 prostitutes were studies in order to determine the prevalences of sexually transmitted disease. The results were as follows: 1. The average age of prostitutes was $24.0\pm3.9$ years. The age group of 21-25 years old was the highest level of about $70.3\%$. 2. The positive rate on non Gonococcal urethites was $9.1\%$ at Sung Buk area and $15.3\%$ at Young Dung Po area. 3. The positive rate of Neisseria Gonorrhoeae on culture of TM media was $6.4\%$ or total level and incidence ratio of Neisseria Gonorrhoeae: Non Gonococcal urethritis was 1: 1.7. 4. The positive rate of PPNG was occupied about $26.3\%$ among the total NG positive case. 5. The positive rate of VDRL Slide Test was $2.9\%$, and antibody Titer level of 1:2 was $38.8\%$. it was the highest of all Titer distribution.

• 전기전자학회논문지
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• 제7권2호
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• pp.260-264
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• 2003

네트워크의 성능 향상에 영향을 미치는 여러 요소 중에서, 본 연구에서는 NIC(Network Interface Card) 버퍼 사이즈(Buffer Size)가 웹 서버와 LAN(Local Area Netwok)에 어떤 영향을 미치는지를 분석하였다. 버퍼 사이즈의 조절을 통해서 내부 네트워크의 패킷 분실율, 처리량, RTT(Round Trip Time), 수신율의 변화를 NS-2를 사용하여 시뮬레이션 해보고 그 결과를 비교하여 이더넷(Ethernet)에서의 웹 트래픽에 미치는 영향을 분석하였다.

• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1338-1348
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• 2004

A simplified method that models the deflagration process occurring in closed or vented vessels is described. When combustion occurs within the spherical or cylindrical vessels, the flame moves spherically or segmentally to the vessel periphery. The volume and area of each element along the propagating flame front are calculated by using simple geometrical rules. For instabilities and turbulence resulting in enhanced burning rates, a simple analysis results in reasonable agreement with the experimental pressure transients when two burning rates (a laminar burning rate prior to the onset of instability and an enhanced burning rate) were used. Pressure reduction caused by a vent opening at predetermined pressure was modeled. Parameters examined in the modeling include ignition location, mixture concentration, vented area, and vent opening pressure. It was found that venting was effective in reducing the peak pressure experienced in vessels. The model can be expected to estimate reasonable peak pressures and flame front distances by modeling the enhanced burning rates, that is, turbulent enhancement factor.

• 보건행정학회지
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• 제22권3호
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• pp.427-450
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• 2012

Objectives : This study examined the factors influencing variation by local areas of antibiotics prescription rate in upper respiratory infections (URI) according to the public reporting. Methods : We used the National Health Insurance Claims Data which the clinics claimed for URI (Korean Standard Classification of Disease, J00 ~ J06) in ambulatory care. The period of analysis was from the first quarter (from January to March) of 2005 to the first quarter of 2007. The number of samples was total 242 local areas that included all clinics (N = 7,942), which prescribed antibiotics for URI in ambulatory care. Results : None of the demographic and socioeconomic characteristic indicators was statistically significant. Among the provider factors, An increase in number of doctors and the average annual antibiotics prescription rate (from 2003 to 2004) for URI by local area were significantly related to an increase of antibiotics prescription rate according to the public reporting. And an increase in number of pediatric clinics, the proportion of clinics less than 5 years since has opened and the average annual fluctuation of antibiotics prescription rate (from 2003 to 2005) were significantly related to a decrease in antibiotics prescription rate by local area according to the disclosure of information. Conclusions : According to the public reporting, the antibiotics prescription rate in clinics had decreased sharply. However, the reduction of antibiotic prescription rate varied in different local areas. The factors influencing variation by local areas in antibiotics prescription rate can be used for establishing effective strategies to reduce variation by region in antibiotics prescription rate.

• 대한치과기공학회지
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• 제25권1호
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• pp.143-159
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• 2003

In this study, the data and the Statistical Annual Report of the Korean Dental Technology Association and the yearbook of Health-Welfare Ministry from 1990 to 2002 were surveyed to study and analyze the yearly increase rate and regional distribution rate of the national dental laboratories and dental clinics, the rate of dental laboratories to dental clinics. The purpose of the thesis is to help dental technicians to open the rational and effective dental laboratory which considers the regional condition and the distribution of dental clinics. The result of the study is as follows; 1) The yearly increase rate of overall dental laboratories is 2.01 times to 2002 by the criteria of 1990. The most laboratories was increased in 1995(+94) but the least laboratories was increased in 2000(+13). According to the regional increase rate, Kyounggi Association showed the highest increase rate (7.00 times) but Woolsan Association showed the least increase rate (1.45 times) for the past 5 years. Busan Association had increased by 1.47 times by the criteria of 1990. 2) According to the regional distribution rate of dental laboratories, Seoul area showed the highest distribution rate from the minimum 26.72%(in 2002) to the maximum 35.23%(in 1990) every year, and before 1993, Busan area showed the high distribution rate of 12.49% and Daegu area 12.38%. 3) In the case of the national increase rate, dental clinics had increased by 2.01 times to 2001 by the criteria of 1990 and dental laboratories, whose number was 1,482 in 2002, had increased by 2.01 times to that year. The rate of the national dental laboratories to dental clinics went up an average of 1: 7.57 for 12 years. In 1994, the rate showed the highest 1:7.91 and in 1990, the rate showed the least 1:7.17. 4) The metropolitan rate of dental laboratories to dental clinics showed the average of 1:6.70 for 12 years, and the rate was highest in 1992(1:7.15) and the rate lowest in 1999(1:6.33). 5) The rate of dental laboratories to dental clinics in other areas was 1:9.53, the average of 12 years and was highest in 1991(1:9.97) and was lowest in 1990(1:8.79). (6) The rate of the Korean dental laboratories to dental clinics was 1:7.37 in 2001, the metropolitan rate was 1:6.53 and the rate in other areas was 1:9.10. According to the regional distribution rate, the rate of Kyounggi was highest (1:15.58) and the rate of Daegu was lowest(1:3.03).

• 한국전산유체공학회지
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• 제19권1호
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• pp.73-79
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• 2014

Three-dimensional turbulent flows of a distribution manifold are studied by a turbulence model. To investigate the geometrical effects of the manifold, the length and area of exit port are changed. From the results, flow structures related to the outflow uniformity are examined and the deparure angles are obtained. The exit configuration depending on the departure angle has advantages to the outflow uniformity. That is, the decreased exit area in the streamwise direction improves the uniformity of exit flow. For the uniform effusion, the change of exit port by departure angle is more effective them the change of exit area.

• 한국항만학회지
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• 제14권4호
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• pp.429-439
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• 2000

The primary purpose of dredging work is to maintain navigational readiness and to increase environmental amenity. Therefore the dredging project, which is composed of excavating, removing, transporting and storing or dumping dredged material, must be carefully managed to insure that dredging works are completed in a cost-effective and environmentally safe method. The most important point in dumping operations is evaluating and decreasing the impacts of dumping works at the dumping area. One of the most effective method for this purpose is using the schematic process composed of the sophisticate plan, precise work and predicting/reducing the impacts based on an numerical model being closely linked with field observation. In this study, a numerical model is used to predict the spatial transport and fate of the effluent discharged from the confined dumping facility(CDF) located at a coastal area. To achive this purpose, numerical models were used for reappearing the tidal current of concerned area. These models were then applied to Mokpo harbpr where capital dredging and maintenance dredging are being conducted simultaneously and the CDF is under construction. In series of model case study, we found that the effluent discharged from CDF was governed by the receiving water condition and outfall geometry, so that limit of near-field was 14∼500 meter down stream and 4∼150 meter in transverse direction. dilution ranged from 1.1 to 8.2 on the cases. Long-term diffusion characteristics was governed by the dilution rate during near-field behavior, ambient conditions and CDF operation modes.

• 한국세라믹학회지
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• 제53권2호
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• pp.241-245
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• 2016

The purpose of this study was to investigate the bloating mechanism of artificial lightweight aggregates with different sizes (ESA, effective surface area). Aggregates were produced using hard clay, stone sludge, and a bloating agent in order to observe the effect of the gradation of the artificial lightweight aggregates. Kerosene and amorphous carbon were used as bloating agent. The particle size of the produced aggregate ranged from 3 mm to 9 mm. With regard to the amount of bloating agent to be used, 2 ~ 6 parts by weight were used. The specific gravity, absorption rate, and the type of aggregates produced by rapid sintering at $1075{\sim}1200^{\circ}C$ were determined. Microstructures were observed. When ESA had a value of 1 or below, kerosene, which has a high burning rate, was found to be advantageous for use as a bloating agent. When ESA had a value of 1 or above, carbon, which has a relatively low burning rate was found to be an advantageous bloating agent. It is thought that kerosene is more advantageous, as ESA decreases, for the production of aggregates having low water absorption rate.