• 한국분말재료학회지
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• 제13권2호
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• pp.138-143
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• 2006

In this study, the effects of the dispersants, i.e., Hypermer KD-2 and poly(l-vinyl-2-pyrrolidone) (PVP), and their concentration on the dispersion stability of Ni nanoparticles ($10nm{\sim}40nm$) in ethanol were investigated by using a visual inspection, a transmission profile (Turbiscan), and a zeta potential measurement. The transmission profiles measured by Turbiscan showed that the particle size increased over the entire height of the sample for suspensions with both the dispersants without showing any particle coalescence and sedimentation. The visual inspection also confirmed that the Ni suspensions with Hypermer KD-2 and PVP were very stable for more than a year. The zeta potential values varied from positive to negative with increasing the dispersant's concentration. The dispersion stability of the suspensions was not affected by both the dispersant's concentration and the zeta potential values. The observed suspension stability of Ni nanoparticles was attributed to the steric effect for the Hypermer KD-2 and to the bridging effect for the PVP.

• 한국약용작물학회지
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• 제16권2호
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• pp.79-85
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• 2008

Some studies of dandelion have been carried out on bioactivities, however, no comparative analysis on antioxidant and cytotoxic activities in the Korean dandelion (T. coreanum NAKAI.; KD) and dandelion (T. officinale WEB.) have been reported. In this study, the extracts of KD and dandelion analyzed relative phenolic contents and free radical scavenging, antioxidant enzyme and cytotoxic activities. The extract of Korean dandelion leaves (KDL) exhibited a higher phenolics content ($368{\pm}11.5\;mg/l00\;g$) and a strong free radical scavenging activity ($RC_{50}$value;87.89 ug/ml) than other parts and BHT (120.12 ug/ml), synthetic antioxidant. At ascorbate peroxidase (APX) activity, the dandelion root (DR) had a greater (38.8 U/mg protein) antioxidant enzyme compare to the dandelion leaves (12.2 U/mg protein). The catalase (CAT) and superoxide dismutase (SOD) followed higher enzyme activity in Korean dandelion root (KDR) than other parts. In a cytotoxic activity against human cancer cell, the extracts of KDR was found to be active against Calu-6, HCT-116, and SNU-601 cell lines, with $IC_{50}$ values of 522.34, 532.74 and 614.85 ug/ml, respectively. These results suggest that KD and dandelion would be an alternative antioxidant source, based on natural plant resources.

• Journal of Applied Biological Chemistry
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• 제42권3호
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• pp.107-112
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• 1999

A carboxymethyl-cellulase (CMCase) was purified from the culture supernatant of Bacillus sp. KD1014 by ultrafiltration, ammonium sulfate precipitation, and a series of chromatography on QAE-Sephadex A-50, hydroxylapatite and Sephadex G-75. The purified CMCase was a single protein of 32 kDa, showed an optimum activity at $60^{\circ}C$ and pH 6.0, and had a half-life of 23 min at $70^{\circ}C$. The enzyme activity was not influenced by metal ions such as $Mg^{2+},\;Fe^{3+},\;K^+,\;Zn^{2+}$, and $Cu^{2+}$ at a concentration of 1.0 mM, partially inhibited by $Mn^{2+}$ and $Ag^+$, and significantly inhibited by pentachlorophenol (PCP). The purified enzyme showed a 3.9-times higher activity on lichenan than on CMC, but hardly cleaved xylan, starch, avicel, laminarin, filter paper and levan. The results of activity staining of the purified enzyme separated by native and denaturing gel electrophoresis suggested that the CMCase might exist in dimeric, oligomeric or aggregated form as well as in monomeric form. The enzymatic cleavage products from cellotetraose indicated that the CMCase possessed transglycosylation activity.

• 한국동물학회지
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• 제37권1호
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• pp.76-87
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• 1994

High density lipophorin-L (HDLP-L) was purified from the hemolymph of Bombyx modi using KBr density gradient ultracentrifugation and gel permeation chromatographv (Sephadex G-2001. Lipophorin has native molecular weight of 730 Nd and consists of Apo-Lp I and Apo-Lp II with molecular weights of 250 Kd and 90 Kd, respectively. Lp contains large amounts of glutamine & glutamic acid, threonine, leucine but small amounts of cysteic acid & oxidized cystine, tyrosine, methionine. Lp also contains diacylglycerol, cholesterol, phosphatidylcholine, and phosphatidylethanolamine. Anti-lipophorin showed positive reaction with fat body and ovarial extracts and also revealed immunological identity with lipophorin of Fall webworm, Hyphantria cunea. Lipophorin maintains constant level during larval and pupal stapes but greatlv increases during adult stage in both male and female. Apo-Lp III was purified from adult hemolymph. Hemolymph was subjected to KBr ultracentrifusation and Lp-free fraction was submitted to cation exchange chromatosraphy after ammonium sulfate precipitation. Apo-Lp III has molecular weight of 17 Kd, and similar amino acid composition ar those of other species Lp but contains high amounts of tryptophan which other are tacking in.

• 마이크로전자및패키징학회지
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• 제24권2호
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• pp.1-9
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• 2017

Recently, there has been a continuous researches on solders having sophisticated and improved performance due to demand for high-density and miniaturization of electronics, and development of solder for automotive electronics which can be used in harsh environment. When developing a new solder alloy, there is a wettability of solder on substrate for things to consider, and the wetting balance test is one of the methods for measuring that one. In this paper, the wetting balance test is introduced, and the calculus of the surface tension of solder and the contact angle between solder and substrate using wetting curve obtained is introduced too. In detail, the principle and test method of the wetting balance test, the introduction of the parameters with important meaning in the wetting curve, the method of calculating the contact angle as well as the surface tension of the solder using the shape of the solder meniscus.

• 한국수소및신에너지학회논문집
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• 제21권2호
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• pp.136-142
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• 2010

Photobiological $H_2$ production was compared using purple non-sulfur bacteria Rhodobacter sphaeroides KD131 in the medium containing various organic acids as the carbon source and electron doner under illumination of $110\;W/m^2$ using halogen lamp at $30^{\circ}C$. The organic acids used were 0~120 mM acetate, butyrate, lactate and malate. Initial pH 7.0 and cell concentration 1.0 at 660nm were increased to pH 8 and 4.4~5.1, respectively during 24hrs of photo-fermentation when lactate and malate were used. However, acetate and butyrate increased pH to 9 and cell concentration to 3.2~3.9 of malate at the same experimental conditions. Optimum ranges of organic acids concentration and carbon/nitrogen ratio were 30~60 mM and 10~20, respectively. When malate was used as the substrate, maximum $H_2$ production 1.1 ml $H_2$/ml broth, which is equivalent to 1.97 mol $H_2$/mol malate was observed.

• 한국산학기술학회논문지
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• 제15권10호
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• pp.5912-5918
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• 2014

산업이 고도로 발달함으로 인하여 화석연료의 사용이 많아짐으로 인하여 환경문제가 대두되고 있으며, 이에 자동차의 매연에 대한 연구가 필요하다. 일반적으로 공기는 흡기 매니폴드를 통하여 엔진에 흡입된다. 따라서 본 연구에서는 매연증가와 출력저하의 하나의 원인이 되는 카본 퇴적물을 세척하여 노후 된 자동차의 배출가스의 저감과 출력향상, 배기가스 저감량, 출력변화 그리고 공전속도의 안정성을 분석 검토하는데 그 목적이 있다. 흡기 매니폴드 내의 카본을 클리닝하였을 때의 자동차 매연의 발생정도를 검사장비(KD147)를 통하여 분석하였다. 흡기 매니폴드 클리닝으로 매연의 감소효과가 있음을 확인하였다.

• 한국기계가공학회지
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• 제20권7호
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• pp.25-32
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• 2021

In the previous study, a study was conducted to improve the exhaust gas intake efficiency by improving the existing soot measurement probe in the shape and angle of the exhaust port. As a result, it can be seen that the smoke measurement performance according to the shape and angle is improved. In previous studies, the performance of the soot probe was not confirmed for the Korean KD 147 mode, which has a low suction flow rate and a long inspection time. So, we would like to confirm the improvement of the smoke probe performance of the Korean KD 147 mode, which is close to the actual driving conditions. The probe used in this study is another type of probe, and has a circular ring shape instead of a rib and variable center position unit, so the probe center hole is located close to the center of the exhaust pipe.

• Communications for Statistical Applications and Methods
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• 제30권5호
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• pp.501-516
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• 2023

Knowledge distillation (KD) refers to extracting knowledge from a large and complex model (teacher) and transferring it to a relatively small model (student). This can be done by training the teacher model to obtain the activation function values of the hidden or the output layers and then retraining the student model using the same training data with the obtained values. Recently, relational KD (RKD) has been proposed to extract knowledge about relative differences in training data. This method improved the performance of the student model compared to conventional KDs. In this paper, we propose a new method for RKD by introducing a new loss function for RKD. The proposed loss function is defined using the area difference between the teacher model and the student model in a specific hidden layer, and it is shown that the model can be successfully compressed, and the generalization performance of the model can be improved. We demonstrate that the accuracy of the model applying the method proposed in the study of model compression of audio data is up to 1.8% higher than that of the existing method. For the study of model generalization, we demonstrate that the model has up to 0.5% better performance in accuracy when introducing the RKD method to self-KD using image data.

• Clinical and Experimental Pediatrics
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• 제50권1호
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• pp.52-55
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• 2007

목 적 : 고빌리루빈혈증과 황달, 담낭수종 등은 가와사끼병의 일부에서 발생한다. 이 경우에 복통과 식욕부진, 복부팽만 등이 나타나 입원 기간이 길어질 수도 있다. 가와사끼병 급성기의 임상과정에서 고빌리루빈혈증의 관련인자가 있는가를 알아보고자 본 연구를 시행하였다. 방 법 : 1997년 1월부터 2004년 12월까지 만 8년간 원광대학병원 소아과에 입원하여 가와사끼병으로 치료받았던 282명의 환자를 대상으로 후향적으로 조사하였다. 나이와 성별, 발열-입원 기간, 치료-해열 기간, 입원 당시의 백혈구수, 혈소판수, ESR, CRP, AST, ALT치와 무균성 농뇨 등을 정상빌리루빈군(A)(n=269)과 고빌리루빈혈증군(B)(n=13)으로 나누어 비교 분석하였다. 통계처리는 Mann-Whitney test와 Fisher's exact test, logistic 회귀분석으로 하였다. 결 과 : 13 례(4.6%)에서 고빌리루빈혈증을 보였고 B군에서 나이와 ALT치가 높았다(P값 각각 0.003, 0.018). 백혈구 증가증이 있었던 경우와 AST/ALT치가 동시에 상승한 경우에는 고빌리루빈혈증의 발현 빈도가 더 높았다(P값 각각 0.007, 0.042). 짧은 발열-입원 기간과 고연령층이 고빌리루빈혈증에 영향을 주는 요인으로 분석되었다(P값 각각 0.007, 0.003). 반면에 ESR, CRP, 혈소판수, AST, ALT, 무균성 농뇨, 치료-해열 기간 등은 영향을 주지 않았다. 결 론 : 소아기의 가와사끼병에서 짧은 발열-입원 기간과 고연령층 환자군이 고빌리루빈혈증의 발현에 영향을 주는 인자로 분석되었다.