• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.155-156
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• 2003

대도시내의 산업단지의 경우 주거지역과 인접하여 위치하고 있기 때문에 산업단지에서 발생하는 오염물질들은 시민들의 생활에 큰 영향을 미치고 있다. 그러나 국내에서는 아직 PM10의 장기적인 연구가 다소 미흡하고 가장 오염이 심하리라고 예상되는 산업단지에서 조차 PM10의 장기적인 자료가 없다. 따라서 장기간 자료에 근거한 대기 중 미량금속의 특성평가, 인체 위해도 분석 및 오염원 평가가 원활히 이루어지지 못하고 있는 실정이다. (중략)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.331-335
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• 1999

LAN, WAN 및 VBR 트래픽 특성에 관한 최근의 실험적 연구들은 기존의 Poisson 가정에 의한 모델들이 네트워크 트래픽의 장기간 의존성 및 self-similar 특성들을 과소평가 함으로써, 실제 트래픽의 특성을 제대로 나타낼 수 없다는 것을 지적해 왔다. 본 본문에서는 실시간 운영중인 Ethernet 트래픽을 측정하여, 통계학적인 접근법들을 통해 이러한 self-similar 특성들에 대해 평가하였다. 그리고 exactly self-similar 모델링인 Pareto-like ON/OFF 소스 모델링에 의한 트래픽과 기존의 Poisson 모델링을 비교 분석함으로써, self-similar 트래픽이 실제의 Ethernet 트래픽 특성을 잘 반영한다는 것을 보였다.

• Childhood Kidney Diseases
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• v.18 no.2
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• pp.92-97
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• 2014

Purpose: Bisphosphonates are widely used for the management steroid-induced osteoporosis (SIO) in children. With the increasing use of bisphosphonates, there have been reports of abnormal radiological findings in the growing skeleton. Therefore, their use in pediatric patients remains controversial. The present study was conducted to evaluate the long-term follow-up radiographic features, particularly metaphyseal sclerotic lines, in children who receive pamidronate therapy for nephropathy. Methods: Twenty-four children with nephropathy treated with oral calcium and pamidronate (mean duration, 9 months; dose, 100 mg daily), were evaluated retrospectively. All patients had SIO secondary to chronic glucocorticoid therapy for treating nephropathy. Long bone radiographic imaging was performed before treatment with pamidronate, and at follow-up, several years later. Physeal growth rates were estimated by measuring the distance that the sclerotic lines moved on the radiographs during the corresponding time intervals. Results: The mean follow-up period was 138 months. Long bone radiographs showed well-defined sclerotic lines at the metaphyseal ends, progressively moving from the physeal plate to the diaphysis, in all patients. The mean rate of movement of the sclerotic line was 6.21 mm per year. In 12 patients, the lines disappeared. The mean rate of growth in height was 7.33 cm per year. Conclusions: Results of long-term follow-up suggest that the metaphyseal sclerotic lines associated with pamidronate treatment tend to disappear without affecting overall skeletal growth. Bisphosphonate treatment for SIO in children with nephropathy seems to be safe, although further studies in larger number of patients are needed.

• Proceedings of the Costume Culture Conference
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• 2004.04a
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• pp.44-46
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• 2004

심하게 퇴색된 출토 복식유물의 경우 유물의 고유색을 알지 못함은 물론 사용된 염료의 종류를 알지 못함으로 인하여 유물의 보존처리 및 장기간 보관과 전시에 큰 어려움을 지닌다. 이화학 분야에서는 미지시료의 기초 성분분석 방법으로서 thin layer chromatography(TLC)법이 오래 전부터 사용되었는데, 퇴색된 복식유물의 염료분석을 다룬 일부 선행연구에서는 이를 활용하여 유물의 염료를 판정하였다(Kharbade ＆ Agrawal, 1985; Schweppe, 1989). (중략)

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.856-861
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• 2002

It has been reported in animal and human studies that green tea shows a health protective characteristics. In the present study, we investigated the disease prevalence according to chronic green tea consumption in 92 subjects (mean age: 59.548.9, men: 41, women: 51) living in green tea cultivation village. The consumption of green tea and other life-style characteristics were ascertained by a questionnaire. The subjects were divided into three groups according to the period of green tea consumption (0, < 10 year, and $\geq$ 10 year). For green tea consumption groups, most of the subjects have been drinking green tea in order to protect disease and recognized the effects of green tea as detoxification of alcohol and smoking, protection of cold or release from fatigue. There were no significant differences in drinking and smoking, physical activity, and a cold prevalence among the groups. Green tea consumption was associated with lower levels of prevalence of tooth decay as well as the osteoporosis. The score of dietary habits was higher by increasing green tea consumption period (p<0.05). Consequently, chronic green tea consumption can be considerably effective in health promotion.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.335-342
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• 2000

The authors observed the long term effects of chlorhexidine varnish treatment on microbial change of dental plaque in orthodontic patients with fixed appliances. The initial sample was 100 patients who were arranged to be treated with fixed orthodontic appliances. The final sample consisted of 21 patients who could be traced for 32 weeks after application of fixed orthodontic appliances. They were classified into the experimental group (12 patients) and the control group (9 patients). The experimental group was treated with chlorhexidine varnish once a week for 4 weeks before application of fixed orthodontic appliance. The control group was not treated with chlorhexidine varnish before application of fixed orthodontic appliance. The experimental group was treated once more after 20 weeks. The microbial changes of dental plaque were analysed by indirect immunofluorescence technique at pre-treatment, post-treatment 4, 8, 20, and 32 weeks. The results were as follows. 1. In the experimental group, streptococus mutans was significantly suppressed during experimental period. (p<0.01) But, in the control group, streptococcus mutans was significantly increased after placement of fixed orthodontic appliances during experiment period. (p<0.05) 2. Streptococcus sanguis, Streptococcus mitis, Actinomyces viscosus, md Actinomyces naeslundii did not show significant change between the experimental and the control group during experiment period. So, if we treat the orthodontic patients with chlorhexidine varnish before application of fixed appliances, we may suppress the major cariogenic bacteria, Streptococcus mutans, selectively for long period.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.279-280
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• 2009

This study is to aim an evaluation of concrete durability exposed to coastal circumstance. Therefore, six cores of the seawater pump were obtained by drilling, and their total chloride content were tested to predict initial time of steel corrosion..

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.443-444
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• 2019

공유경제 시대의 다양한 전기구동플랫폼 운용에 유효한 새로운 유지보수 가이드라인을 도출하고자, 본 연구는 하이브리드자동차와 전기자동차의 특성을 모두 갖는 PHEV의 장기간 주행 데이터를 분석하여, 주요 부품의 상태 변화를 파악하였다. PHEV의 모터, 인버터, 2차전지 등 주요 부품의 주행 데이터 변화를 관찰하여 마일리지 누적에 따른 상태변화가 큰 부품을 파악하였다. 분석결과 1만Km 이상 주행 시 보조 배터리의 온도와 5만Km 이상 주행 시 2차전지의 온도 변화가 유의미하게 발생함을 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.41-41
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• 1999

핵융합 장치의 플라즈마 운행동안 토카막 내벽에 도달하는 온도는 최저 $600^{\circ}C$ 이상이다. 또한 플라즈마 자체와 사용자(User)들의 시료로부터 방출되는 입자들에 의한 내벽 충격(damage)은 장기간의 안정적인 운행 및 연구에 심각한 영향을 미친다. 이러한 이유로 토카막 제작시 내벽 보호재의 선정은 매우 높은 비중을 차지한다. Graphite는 높은 융점과 가공의 용이성으로 토카막 내벽의 보호재로 선호되는 물질이다. 그러나 토카막 용기(vessel)에 사용되는 스테인레스 스틸(AISI 316LN)보다 약 50배 이상의 기체 방출율(outgassing rate)을 가진다. 그러므로 장착 이전의 초기 청정화 과정이 매우 중요하며, 특히 400m2의 약 2톤(2000kg)의 graphite가 사용되므로 대량 처리를 할 수 있는 방법의 선정도 함께 개발되어야 한다. 본 연구팀에서는 처음 10개 회사의 시제품을 검토한 후, 최종 2개 회사의 4가지 종류의 시료를 선정하였다. 선정된 시료는 Union Carbide의 ATJ와 Toyo Tanso의 IG-110, IG-43, Ig-430이다. 시료는 비절삭유(oil-free) 가공에 의해 80$\times$2$\times$3 (mm)의 크기로 제작되었고 에탄올과 메탄올 용액에서 초음파 세척되었다. 건조된 시료는 TDS(Thermal Desorption Spectroscopy) 장치에 장착되어 세 단계의 실험을 하였다. 처음은 승온(상온 ~100$0^{\circ}C$)에 의한 방출 기체의 성분 분석, 두 번째는 장기간 (2주) 대기 노출 후 주요 방출 기체의 온도에 따른 변화, 마지막으로는 특정 기체에서의 장기간 보관후, 주요 방출 기체의 온도에 따른 변화를 조사하였다. 다음 그림 1은 본 연구에서 사용된 TDS 장치의 개략도이고 그림 2는 TDS 장치에 장착 직 후와 대기 중 노출된 시료들의 온도증가에 따른 총 압력의 변화이다.

• Journal of Korea Water Resources Association
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• v.40 no.4
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• pp.325-334
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• 2007

In this study, a long-term unsteady simulation model has been developed using rigid water column theory which is more accurate than Extended-period model and more efficient comparing with water-hammer simulation model. The developed model is applied to 24-hours unsteady simulation considering daily water-demand and water-hammer analysis caused by closing a valve. For the case of 24-hours daily simulation, the pressure of each node decreases as the water demand increase, and when the water demand decrease, the pressure increases. During the simulation, the amplitudes of flow and pressure variation are different in each node and the pattern of flow variation as well as water demand is quite different than that of KYPIPE2. Such discrepancy necessitates the development of unsteady flow analysis model in water distribution network system. When the model is applied to water-hammer analysis, the pressure and flow variation occurred simultaneously through the entire network system by neglecting the compressibility of water. Although water-hammer model shows the lag of travel time due to fluid elasticity, in the aspect of pressure and flow fluctuation, the trend of overall variation and quantity of the result are similar to that of water-hammer model. This model is expected for the analysis of gradual long-term unsteady flow variations providing computational accuracy and efficiency as well as identifying pollutant dispersion, pressure control, leakage reduction corresponding to flow-demand pattern, and management of long-term pipeline net work systems related with flowrate and pressure variation in pipeline network systems