• Journal of Nutrition and Health
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• 제35권2호
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• pp.183-191
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• 2002

The purpose of this study was to investigate the effect of dietary mushroom powder on blood glucose levels, seam lipid levels, glucose 6-phosphtase (G6Pase), thiobarbituric arid reactive substance (TBARS) and glutathione enzymes in diabetic rats treated with streptozotocin (STZ). Four groups of rats (Sprague-Dawley male rats, 180-200 g) were fed as follows: normal rats were fed a control diet (C), diabetic rats were file a control diet (CD), normal fats were fed a mushroom powder diet (M), and diabetic rals were find mushroom powder diet (MD). Diabetes was induced by single injection of streptozotocin (60 mg/kg B.W.). The animals were fed ad libium each of the experimental diets for five weeks. Food and water intake was determined every day. Blood glucose and serum total cholesterol levels were determined every week. After five weeks, the rats were sacrificed and blood glucose, serum total cholesterol, triglyceride levels and glutathione enzymes were measured. HDL-cholesterol levels were analyzed and LDL-cholesterol concentrations were calculated by equation. There was body weight loss in the diabetic rats, but the MD group showed less body weight loss than the CD group. Blood glucose and serum total cholesterol level of the MD group were lower than those of the CD group (p < 0.05). Also, serum total cholesterol of the M group was lower than that of the C group (p < 0.05). But the serum triglyceride level of the diabetic rats (CD and MD) was higher than that of the normal rats (C and M). However, there was no significant difference between the control diet group and the mushroom diet group. Serum HDL-cholesterol levels of the C group and CD group were higher than that of the M group (p < 0.05), and the MD group was not significantly different. But the serum LDL-cholesterol levels of the M group were lower than those of the C group (p < 0.05). Activity of hepatic microsomal G6Pase significantly increased in the CD and MD, reaching levels higher than those of the C and M groups. Hepateic gutathione S-transferase (GST, glutathione reductase (GR) and glutathione peroxidase (GPX) activity was not significant. But renal GST, GR and GPX activity in the MD group was lower than that of the CD group (p < 0.05). These results suggest that dietary mushroom reduces renal disorders such as oxidation and aging of tissue. In conclusion, dietary mushroom groups reduced blood glucose and cholesterol levels in STZ-induced diabetic rats and renal glutathione enzymes activity was averted in diabetic rats.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1530-1530
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• 2001

The objectives of this study were to develop models to predict quality parameters of Korean bee-honeys by visible and NIR spectroscopic technique. Two kinds of bee-honey fronl acacia and polyflower sources were tested in this study. The honeys were harvested in the spring of 2000 and stored in the storage facility at 20$^{\circ}C$ during experiments. Total of 394 samples of honey were analyzed. Reflectance spectra, moisture contents, ash, invert sugar, sucrose, F/G (fructose/glucose) ratio, HMF (hydroxymethyl furfural), and C12/C13 ratio of honeys were measured. The average values for the tested honeys were 19.9% of moisture contents, 0.12% of ash, 68.4% of invert sugar, 5.7% of sucrose, 1.27 of F/G(fructose/glucose) ratio, 14.4 mg/kg of HMF, and -19.1 of C12/C13 ratio. A spectrophotometer, equipped with a single-beam scanning monochromator (NIR Systems, Model 6500, USA) and a horizontal setup module, was used to collect reflectance data from honey. The reflectance spectra were measured in wavelength ranges of 400∼2,498 nm. with 2 nm of interval. Thirty-two repetitive scans were averaged, transformed to log(1/Reflectance), and then were stored in a microcomputer file, forming one spectrum per measurement. A sample cell and reflectance plate were made to hold honey samples constantly. Spectra of honey samples were divided into a calibration set and a validation set. The calibration set was used during model development, and the validation set was used to predict quality parameters from unknown spectra. The PLS(Partial Least Square) models were developed to predict the quality parameters of honeys. The first and the second derivatives of raw spectra were also used to develop the models with proper smoothing gap. The MSC (multiplicative scatter correction) and the SNV & Dtr.(standard normal variate and detranding) preprocessing were applied to all spectra to minimize sample-to-sample light scatter differences. The PLS models showed good relationships between predicted and measured quality parameters of honeys in the wavelength range of 1100∼2200 nm. However, the PLS analysis was not good enough to predict HMF of honeys.

• 대기
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• 제23권1호
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• pp.93-102
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• 2013

Atmospheric transport pathway of an air mass is an important constraint controlling the chemical properties of the air mass observed at a designated location. Such information could be utilized for understanding observed temporal variabilities in atmospheric concentrations of long-lived chemical compounds, of which sinks and/or sources are related particularly with natural and/or anthropogenic processes in the surface, and as well as for performing inversions to constrain the fluxes of such compounds. The Lagrangian particle dispersion model FLEXPART provides a useful tool for estimating detailed particle dispersion during atmospheric transport, a significant improvement over traditional "single-line" trajectory models that have been widely used. However, those without a modeling background seeking to create simple back-trajectory maps may find it challenging to optimize FLEXPART for their needs. In this study, we explain how to set up, operate, and optimize FLEXPART for back-trajectory analysis, and also provide automatization programs based on the open-source R language. Discussions include setting up an "AVAILABLE" file (directory of input meteorological fields stored on the computer), creating C-shell scripts for initiating FLEXPART runs and storing the output in directories designated by date, as wells as processing the FLEXPART output to create figures for a back-trajectory "footprint" (potential emission sensitivity within the boundary layer). Step by step instructions are explained for an example case of calculating back trajectories derived for Anmyeon-do, Korea for January 2011. One application is also demonstrated in interpreting observed variabilities in atmospheric $CO_2$ concentration at Anmyeon-do during this period. Back-trajectory modeling information introduced in this study should facilitate the creation and automation of most common back-trajectory calculation needs in atmospheric research.

• 한국산학기술학회논문지
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• 제18권7호
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• pp.394-399
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• 2017

본 국내 교류전철변전소에서는 주변압기 2차측의 위상각이 $90^{\circ}$인 단상 전원을 얻도록 한 스코트 결선 변압기를 설치 운용 하고 있다. 변압기 보호계전기는 내부에서 고장이 발생하는 경우 변압기 전단에서 전력을 차단시키고 변압기 외부 계통의 사고나 일반차량 운행의 경우에는 동작하지 않아야 한다. 정확한 고장의 판단으로 오동작을 줄이는 것이 전력계통을 안정적으로 유지하고 신뢰성을 향상시키는 측면에서 매우 중요하다. 주 변압기 내부 고장 검출장치로는 브흐홀쯔계전기와 비율차동계전기를 설치하여 변압기를 보호하고 있지만 비율차동계전기의 오동작으로 인해 보호기능을 비활성화 시켜놓은 상태로 운용하는 사례가 있다. 본 논문에서는 스코트 변압기의 특성과 비율차동계전기의 특성을 제시하고 보호계전기의 오동작 사례를 분석하였다. 이를 위해 전력계통 해석프로그램을 이용하여 스코트 변압기에 사용되는 비율차동계전기를 모델링하고 A변전소의 Comtrade 파일로 저장된 고장파형을 입력데이터로 사용하여 동작여부를 판단하여 고조파 분석을 수행하였다. 또한, 고장파형 분석을 통해 오동작 사례에 대한 개선 방안을 도출하고자 한다.

• 정보과학회 논문지
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• 제41권9호
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• pp.674-685
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• 2014

지식 서비스 시스템이 효과적인 서비스를 제공하기 위해서는, 명시된 지식을 바탕으로 새로운 지식을 추론 할 수 있어야 한다. 대부분 지식 서비스 시스템은 온톨로지로 지식을 표현한다. 실 세계의 지식 정보의 양은 점점 방대해지고 있으며, 따라서 대용량 온톨로지를 효과적으로 추론하는 기법이 요구되고 있다. 본 논문은 클라우드 컴퓨팅 환경을 기반으로 대용량 온톨로지를 RDFS수준으로 추론하기 위한 분산 테이블 조인 방법을 제안하고, 성능을 평가한다. 본 논문에서 제안하는 RDFS 추론은 분산 파일 시스템 환경에서 RDFS 메타 테이블을 기반으로 맵-리듀스를 적용한 방식과, 맵-리듀스를 사용하지 않고 클라우드 컴퓨터의 메모리만 사용한 방식에 초점을 맞추었다. 따라서 본 논문에서는 제안하는 각 기법에 대한 추론 시스템 구조와 RDFS 추론 규칙에 따른 메타 테이블 설계 및 추론 전략 알고리즘에 대해서 중점적으로 설명한다. 제안하는 기법의 효율성을 검증하기 위해 온톨로지 추론과 검색 속도를 평가하는 공식 데이터인 LUBM1000부터 LUBM6000을 대상으로 실험을 수행 하였다. 가장 큰 LUBM6000(8억 6천만 트리플)의 경우, 메타 테이블 기반의 RDFS 추론 기법은 전체 추론 시간이 13.75분(초당 1,042 트리플 추론) 소요된 반면, 클라우드 컴퓨터의 메모리를 적용한 방식은 7.24분(초당 1,979 트리플 추론)이 소모되어 약 2배정도 빠른 추론 속도를 보였다.

• 한국정보과학회논문지:정보통신
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• 제34권6호
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• pp.514-524
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• 2007

무선랜의 보편화와 속도증가로 인해 시스템 성능향상을 위한 기회적 스케줄링 기법의 중요성이 증대되고 있다. Voice-over-IP, peer-to-peer와 같은 새로운 응용 프로그램의 증가와 함께 무선랜 트래픽은 점점 더 상하링크 대칭이 되어가고 있으며, 그에 따라 무선랜 하향링크에 편중된 기회적 스케줄링 기법만으로는 공유된 한 개의 무선 채널의 효율을 높일 수 없게 되었다. 그러나, 무선랜의 채널 특성은 시간에 따른 변화가 크며 또한 상하대칭적이지도 않기 때문에, 무선랜 상향링크에서의 기회적 스케줄링은 결코 쉬운 문제가 아니다. 각 전송 클라이언트는 access point에게 채널상황을 보고해야 하며, 스케줄링 결정은 모든 클라이언트들의 동의를 얻어야만 한다. 본 논문에서는 무선랜 환경에서 협동 상향/하향 링크 기회적 스케줄링 기법 JUDS(joint uplink/downlink opportunistic scheduling for WLANs)을 제안한다. JUDS는 상향과 하향링크 스케줄링을 결합함으로써 채널의 상이점을 최대화하며 오버헤드를 최소화한다. JUDS는 또한 상향과 하향링크 사이에 균등한 채널 공유를 하도록 한다. Qualnet 시뮬레이션을 통해, JUDS는 최대 127%의 성능향상을 보이며, 상향/하향 링크 사이 완벽에 가까운 균등한 채널 공유를 보인다.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.429-446
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• 1994

이 연구의 목적은 spreader를 전기적으로 가열, 냉각시킬 수 있는 Endotec을 이용하여 가온 측방가압 근관충전한 근관에서 근단공을 통한 누출의 정도를 정선적 및 정량적으로 측정하여 근관폐쇄효과를 평가하는데 있다. 발거된 단근치 140개를 4개군으로 나누어 45번 file 크기까지 근관형성하고, sealer를 사용한 측방가압법 및 가온 측방가압법, sealer를 사용 않은 가온 측방가압법 및 고온 용융 gutta-percha 주입법으로 근관충전하고 2% methylene blue 용액에 24시간 경과시킨 다음 색소침투 정도를 정선적 및 정량적으로 측정하였다. Sealer를 사용한 가온 측방가압 충전법은 sealer를 사용한 측방가압법 보다 정선적 및 정량적 측정 모두에서 색소침투는 적게 나타났으나 통계학적 유의성은 없었다. Sealer를 사용한 가온 측방가압 충전법은 sealer를 사용 않은 가온 측방가압 충전법 및 고온용융 gutta-percha 주입 충전법 보다 정선적 및 정량적 측정 모두에서 유의성 있게 적은 색소침투를 보였다 (p<0.05). 가온 측방가압 근관충전법의 근관폐쇄효과가 우수하였다는 증거는 통계학적으로 검증되지 않았다. 정선적 측정치와 정량적 측정치 사이에는 유의한 상관관계가 있었다(r=0.4459, p<0.05).

• Restorative Dentistry and Endodontics
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• 제15권2호
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• pp.46-57
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• 1990

초음파진동과 열을 이용하는 초음파 금관충전법의 근관페쇄효과를 연구하기 위하여 색소회복법(dye recovery method)에 기초한 분광광도계 측정법으로 근단공 누출정도를 정량적으로 측정하였다. 발거된 상하악 중절치 및 측절치에서 치관을 절제한 120개의 치근에 재래식 방법으로 근관형성을 하고 측방가압법, McSpadden 근관충전법 및 초음파 근관충전법으로 근관을 충전한 후 $37^{\circ}C$ 항온기내에서 2% methylene blue에 10일간 침지시킨 다음 색소용출을 위해 60% 질산에 용해시키고 색소회복법에 의한 분광광도계 측정을 시행한 후 검량선에 의한 누출량을 산출하여 통계학적으로 상호비교 하였다. 초음파 근관충전법의 색소침투량은 sealer 사용유무와는 관계없이 측방가압충전법과 유사하게 나타났고 McSpadden 충전법은 측방가압법보다 색소 침투량이 더 많이 나타났다. 측방가압풍전법과 초음파 근관충전법에서는 sealer를 병용시 근관폐쇄효과는 양호하였으나, McSpadden 근관충전법에서는 sealer 사용유무에 따른 근관폐쇄효파는 별 차이가 없었다.

• Restorative Dentistry and Endodontics
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• 제27권5호
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• pp.535-542
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• 2002

The purpose of this study was to evaluate the effect of EDTA irrigant according to application time and temperature. 31 human mature extracted teeth with a single canal were sectioned with microtome in 3mm thickness and gained 62 samples of root canals. They were distributed randomly into 6 groups of 10 specimens each and control group of 2 specimens. Each specimen was prepared with GT rotary file (Dentsply, Maillefer Co., Swiss) and irrigated with 3 ml sodium hypochlorite every minute. Then smear layer was removed with EDTA solution (PULPDENT$^{\circledR}$, PULPDENT Co., USA.) except two control specimens. Specimens of each group were irrigated with 17% EDTA. The time and temperature of application were as follows : (Table omitted) All specimens were split longitudinally and prepared for examination by scanning electron microscopy. A set of reference micrographs was used to award a debris score as follows: 0 = no smear layer, all tubules clean and open; 1 = no superficial smear layer, tubule openings visible, but some contain debris plug or soft tissue remnants: 2 = moderate smear layer, some tubules open and others closed; 3 = heavy smear layer, most/all tubule openings obscured. Results were evaluated with Kruskal-Wallis test to determine whether there was statistically significant difference among six groups. Pairs of groups were analyzed using the Student-Newman-Keuls Method and Mann-Whitney test. The results were as follows : 1. Control specimens showed heavy smear layer at the canal walls 2. Among the groups applied with EDTA for 2 minutes, group 1 showed the heaviest smear layer, and there was statistically significant difference between group 1 and the other groups(p<0.05). 3. Among the groups applied with EDTA for 5 minutes, group 4 and group 6 showed smear layer but there was no significant difference between them. 4. Among the groups applied with EDTA for the same temperature, group 1 showed heavier smear layer than group 4, and there was statistically significant difference(p<0.05). 5. Among the groups applied with EDTA for the same temperature, group 2 showed heavier smear layer than group 5 and group 3 showed heavier smear layer than group 6. But there was no statistically significant difference among them. From the results above, it could be concluded, EDTA solution is effective in removing of smear layer when it is applied for 5 minutes. If EDTA is applied for 2 minutes, it should be applied above room temperature.

• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.66-76
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• 2002

The purpose of this study is to evaluate the effectiveness of customized master cone on apical sealing in various apical size of prepared root canals, that is MAF(Master Apical File) and to know at which apical size the apical leakage is to be significantly reduced using customized master cone. 120 extracted single rooted premolars were divided into four groups according to their apical size(MAF), #30, 40, 50 and 60. And then, each group was subdivided into three in accordance with three obturation methods, lateral condensation with standardized master cone, lateral condensation with chloroform-dipped customized master cone, and continuous wave of obturation technique. Resorcinol-formaldehyde resin was used for the microleakage test of this study. Teeth were sectioned horizontally at 1.5mm(Level 1), 2.5mm(Level 2), and 3.5mm(Level 3) from the anatomical root apex using low speed microtome. All sections were examined under $\times$40 magnification with a stereomicroscope, photographed, and then scanned. With the scanned images, resin-infiltrated area presenting the microleakage was calculated using SigmaScan/Image, and the ratio of leakage to the total root canal area of each group was analyzed statistically(one way ANOVA). The results were as follows ; 1. In groups of MAF #30, there was no significant difference of mean leakage ratio among three obturation methods at all three levels. 2. In groups of MAF #40, the group using lateral condensation with customized master cone had the low-est mean leakage ratio at all three levels, but there was no significant difference among three obturation techniques. 3. In groups of MAF #50, the mean leakage ratio of the group using lateral condensation with standard master cone was the highest among those of three obturation techniques at level 1, and this difference was statistically significant(p<0.05). 4 In groups of MAF #60, the groups using lateral condensation with standard master cone had also the highest mean leakage ratio at all levels, but there was no significant difference at level 1 and 2. At level 3, the leakage of the group using lateral condensation with standard master cone was significantly higher than that of the group using continuous wave of obturation(p<0.05). The results of this study suggested that the obturation method using customized master cone or the continuous wave of obturation is more effective for apical sealing than that using standardized master cone when MAF is larger than ＃50.