• Electronics and Telecommunications Trends
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• v.28 no.2
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• pp.20-28
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• 2013

항공기에서 소프트웨어가 차지하는 비중은 점점 늘어나는 추세이다. 항공 전자 시스템의 기능에 대한 요구는 점점 커지고 있으며 시스템의 복잡성을 증대시키고 있다. 이러한 추가되는 기능들로 인해 코드의 양이 늘어나고 있으며 이에 대한 비용이 증가하고 있다. 또한 컴퓨터, 센서, 디스플레이 등과 같은 항공 전자 시스템의 기술 영역들은 빠르게 성장하여 부피와 무게 및 에너지 소모 등의 비용은 줄어든 반면 성능은 크게 향상되었다. 이런 변화에 맞추어 항공 전자 시스템의 구조도 변화하고 있으며 탑재되는 항공용 운영체제도 그에 맞게 변화하고 있다. 항공용 운영체제에 필요한 기술과 최신 운영체제 현황에 대하여 소개한다.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.267-270
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• 2009

오늘날 전자 장비는 매우 다양한 기능의 채용으로 많은 양의 부품을 필요로 하고 그에 따른 전체 시스템의 무게와 크기를 줄이기 위해 소형화와 슬림화가 필수적이다. 따라서 다수의 부품 사용과 고성능화로 인한 열 발생 밀도도 크게 증가하여 열로 인한 온도 상승이 부품의 성능에 매우 중요한 요소로 작용하고 있다. 기기에서의 지속적인 열 발생은 기기를 탑재하고 있는 전체 시스템의 성능에도 큰 영향을 미치며, 특히 고온의 외기에 장시간 노출된 디지털전광판의 시효문제는 시급히 해결해야 할 당면 과제이기도 하다. 본 연구에서는 이와 같은 LCD 패널의 발열로 인한 기기의 성능 저하와 다운 현상을 예방할 수 있도록 열전소자를 이용한 알루미늄 압출형 히트싱크에 대한 열 저항기술을 개발하고, 냉각모듈에 대한 설계기술을 확보하여 LCD 패널용 고효율의 냉각시스템의 개발 과제를 수행했다.

• Korean Journal of Materials Research
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• v.7 no.7
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• pp.564-570
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• 1997

용융산화에 의한 AI$_{2}$O$_{3}$복합재료의 형성에 미치는 합금원소의 영향을 연구하였다. AI-Mg-3Si 합금이 가장 우수한 산화거동을 보였다. 우수한 3원계로 선정된 AI-1Mg-3Si합금에 제 4원소 Sn, Cu, Ni, Zn을 양을 달리하여 각각 첨가하여 산화거동을 살펴보았다. 1273K, 1373K, 1473K, 에서 20시간 각각 산화실험을 한 결과, 1473K에서는 모든 합금계가 우수했으나 1373K, 1273K에서는 산화가 거의 일어나지 않았다.

• Development and Reproduction
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• v.15 no.4
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• pp.373-383
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• 2011

Tributyltin (TBT) is one of endocrine disrupters which are known as having similar function to sex steroid hormone inducing apoptosis in various tissues of rodents. Recently, it has been reported that TBT induces apoptosis in thymus causing the decreased thymic function, but little is known about the mechanism. To elucidate the mechanism, three-week-old SD female rats were orally administrated with TBT 1, 10, and 25 mg per body weight (kg) and sesame oil as a control for 7 days. On day 8, the thymi were obtained and weighed, and then the number of thymocytes was counted. We also performed H&E staining, TUNEL assay, and Annexin V flow cytometric analysis to examine the apoptosis rates and the structure in the thymus. Next, we investigated the adipogenesis and apoptosis-related mRNA expression levels in the thymi by real-time PCR. The thymic weight and the number of thymocytes were decreased by TBT in a dose-dependent manner. As a result of the H&E staining, the boundary between cortical and medullary area was blurred in the thymi of TBT treated rats compared to those of controls. In the results of TUNEL assay and Annexin V flow cytometric analysis, apoptosis rates in the thymus were increased after TBT treatment. The expression levels of thymic epithelial cell marker genes such as EVA, KGF, AIRE, and IL-7 were significantly decreased in the thymi of TBT treated rats, but $PPAR{\gamma}$, aP2, PEPCK, and CD36 were significantly increased. The expression of $TNF{\alpha}$ and TNFR1 as apoptosis-related genes also was significantly increased after TBT treatment. The present study demonstrates that TBT can increase the expression of adipogenesis and apoptosis-related genes leading to apoptosis in the thymus. These results suggest that the increased adipogenesis of thymus by TBT exposure might induce apoptosis in the thymus resulting in a loss in thymic immune function.

• The Korean Journal of Zoology
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• v.34 no.2
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• pp.203-208
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• 1991

Body weight gain in the niadn deficient group of quail was markedly lowered as compared to that of the control group, but heart, kidney and liver weight were slighdy reduced reladve to the body weight. Nicotinic acid deficiency resulted in the significant increase of serum glucose level but the serum cholesterol, albumin and total protein levels were not affected to any extent. Glutamic oxaloacetate iransaminase and glutamic pyruvate transaminase activities were significandy enhanced but alkaline phosphatase and lactic dehydrogenase activities were not influenced. Tryptophan and tyrosine levels were remarkably reduced and a similar observation was also made with aspartic acid, glutamic acid and alanine plus serine. However, the levels of basic amino acids such as arginine, histidine and lysine plus branched chain amino acids such as isoleucine, leucine and valine were not affected.

• Journal of the Korean Ceramic Society
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• v.27 no.8
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• pp.956-956
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• 1990

A nitrogenation of coal ash in the presence of carbon was carried out to examine the effects of reaction temperature, reaction time and carbon composition on the formation of AlN, SiC and Si3N4. Decreasing the particle size increased the formation of AlN and its maximum composition in the product was obtaiend under 1450∼1500℃, 2 hours of reaction time and about 30% of carbon addition(on the basis of sample weight). Compositions of SiC and Si3N4 were distributed to the opposite so that SiC showed a higher composition compared with Si3N4 at a lower temperature, a shorter reaction time and a greater carbon addition.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.924-929
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• 2004

Quality characteristics of functional bread added with different concentrations of potato juice and processed by basic formulation were investigated. Specific volume and baking loss of bread added with 20% potato juice (potato juice : water = 20 : 80) were the highest. Moisture and crude protein contents increased with increasing content of potato juice, while crude lipid content decreased. Lightness (L value) and yellowness (b value) of bread decreased with increasing content of potato juice, while redness (a value) increased. Texture measurement showed springiness, cohesiveness, and brittleness increased with increase of potato juice content. Highest sensory scores for color (p < 0.001), flavor, and taste (p < 0.05) were obtained from bread added with 20% potato juice, while appearance (p < 0.01) and texture (p < 0.01) of control bread were highest. Glycoalkaloid contentsof bread added with 50 and 100% potato juice were 2.85 and 5.79 mg%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1813-1822
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• 2012

The purpose of this study was to determine the optimal mixing conditions of two different amounts of purple barley flour ($X_1$), and olive oil ($X_2$) in baking white pan bread. The experiment was designed according to the central composite design of response surface methodology, which showed 10 experimental points including 2 replicates. The more purple barley flour added, the more weight, yellowness (b-value), hardness, gumminess, and chewiness increased; but the more volume, specific loaf volume, lightness (L-value), and springiness decreased. The greater the amount of olive oil added, the more hardness, cohesiveness, gumminess, and chewiness increased; but the more yellowness (b-value) and springiness decreased. The physical and mechanical properties were affected more by the amount of purple barley flour than by the amount of olive oil. Sensory properties except flavor were more affected by the amount of purple barley flour than by the amount of olive oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.689-696
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• 1997

The effects of Aralia canescens and Phellodendron amurense(AP) extracts on the experimental diabetes in ICR mice were investigated. 96male ICR mice were induced diabetes mellitus by intrape-ritoneal streptozotocin injection(75mg/kg B.W.) and divided into two injection groups which are 5 day injection and 10 day injection group. Then, each injection group was subdivided into 8 groups of 6 animals repspectively. CIC served as control and CI1, CI2 and CI3 were treated with 50, 150, 250mg/kg B.W. of AP extracts powder in 0.9% NaCl solution. Animals of groups DIC, DI1, DI2 and DI3 were strepto-zotocin-induced diabetes. DIC served as diabetic control and the rest groups received 50, 150, 250mg/kg B.W of AP extracts powder in saline solution respectively. The body weight, liver and kiney weight changes and blood levels of glucose, cholesterol and triglyceride were measured. Thiobarbituric acid reactive substance(TBARS), and glutathione reductase(GR) and glutathione peroxidase(GPx) activities were also measured for determining antioxidant effects. AP extracts increased the body weight in diabetic groups. The liver and kidney weight/100g B.W. in DIC group were greater than those of normal ICR group but after AP extracts injection, liver and kidney weight were decreased significantly. These effects were more efficient at 10 days injection group. The total, LDL, VLDL cholesterol and triglyceride levels were significantly higher in DIC group and the extent of decrement responded to AP injection dose. The contents of TBARS and antioxidant enzyme activities were relatively decreased after AP extracts injection. These results suggest that the intraperitoneally administered AP extracts may have not only hypoglycemic effect but act as antioxidants by reducing lipid peroxidation.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.199-205
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• 2013

We investigated the anti-obesity effects of Ishige okamurae extract (IOE) on body weight, epididymal adipose tissue weight, plasma lipid levels, and leptin levels in high-fat diet (HFD)-induced obese mice. After inducing obesity by feeding 45% HFD for 4 weeks, C57BL/6J mice were randomly assigned to HFD or HFD containing 5% IOE, and then fed for 6 weeks. The body weight and epididymal adipose tissue weight were increased by HFD, but they were significantly less in animals fed HFD containing 5% IOE than in those fed HFD. Levels of plasma triglyceride, total cholesterol, and LDL-cholesterol were significantly lower, but the HDL-cholesterol level was significantly higher in animals fed HFD containing 5% IOE compared with the HFD group. The plasma leptin level was significantly lower in animals fed HFD containing 5% IOE. The diet containing 5% IOE did not show any adverse effects on liver and kidney functions. These results suggest that IOE has a potential as anti-obesity agent by reducing body weight and lowering the levels of obesity-related factors in plasma.