• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.15-23
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• 2003

Interest in the regulation of body weight and the pathological physiology of obesity has been rekindled by the cloning of the obese(ob) gene and identification of its product, leptin, in 1994. The first publication appeared in Nature and is a milestone of obesity research. The remarkable metabolic effects of leptin in rodents are: a) inhibition of food intake, b) stimulation of energy expenditure, and c) reversal of obesity. These effects, though mostly desirable, have not been fully demonstrated in humans. The central action of leptin in the regulation of body weight includes two pathways in rodents: a) When the body weight increasing, more leptin is secreted from adipose tissue, which acts on hypothalamus, probably through a POMC or MSH pathway via M4 receptor, initiates a series of response to obesity, i.e. sympathetic tone increased, energy expenditure enhanced and food intake reduced. b) When body weight reduced, leptin concentration decreased with the shrinkage of fat mass, which may also act on the hypothalamus, probably through a NPY-Y5 receptor pathway. Then a cascade of response to hungry was induced, i.e. increase of parasympathetic tone and food intake, decrease of energy expenditure and body temperature, as well as shut-down of the reproductive function.

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.149-155
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• 2016

Sprouty (Spry) genes encode inhibitors of the receptor tyrosine kinase signaling cascade, which plays important roles in stem cells. However, the role of Spry4 in the stemness of embryonic stem cells has not been fully elucidated. Here, we used mouse embryonic stem cells (mESCs) as a model system to investigate the role of Spry4 in the stem cells. Suppression of Spry4 expression results in the decreases of cell proliferation, EB formation and stemness marker expression, suggesting that Spry4 activity is associated with stemness of mESCs. Teratoma assay showed that the cartilage maturation was facilitated in Spry4 knocked down mESCs. Our results suggest that Spry4 is an important regulator of the stemness and differentiation of mESCs.

• 한국멀티미디어학회논문지
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• 제8권2호
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• pp.154-163
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• 2005

XML 문서를 위한 현재까지 연구된 대부분의 색인기법에서는 절대좌표를 표현하는 방법을 이용하기 때문에 갱신연산이 커다란 부담으로 받아들여지고 있다. 또한 이 기법에서 XML문서내의 엘리먼트, 애트리뷰트, 텍스트 사이의 상호 구조적 관계를 표현하려면 좌표를 재구성해야 한다. 이와 같은 재구성 작업은 갱신이 이루어지는 노드에 국한하지 않고 XML 문서 전반에 걸쳐 연쇄적으로 일어나기 때문에, XML 문서의 갱신이 빈번할 경우 심각한 성능 문제를 야기하게 된다. 본 연구에서는 갱신이 빈번한 상황에서도 성능 저하가 많지 않은 확장 색인에 기반한 색인 기법을 제안하고자 한다. 이 방법은 갱신으로 인한 트리의 재구성 연산에 참여하는 노드의 수를 제한하여 전체적으로 성능을 많이 향상시킬 수 있다. 또한 확장색인 기법은 SQL 문장을 이용한 간결한 표현을 통하여 포함관계질의를 처리할 수 있다.

• 생약학회지
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• 제40권1호
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• pp.77-81
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• 2009

Abies nephrolepis(Pinaceae) extracts were tested for determined immune system regulating activity based on antiinflammatory activity, antioxidant activity and anti-proliferative effect on HeLa cell line. The A. nephrolepis extracts increased dose-dependently anti-proliferation of HeLa cell line. The DM fraction of the extracts having anti-proliferatative effects of HeLa cell line was fractionalized four subfractions($D1{\sim}D4$). Inflammation-induced NO production was inhibited by D2 and D4 in LPS-activated RAW264.7 macrophages. And also, this fractions showed antioxidant activity examined by DPPH radical scavenging effects. These results suggest that the potential use of DM fraction of A. nephrolepis in chemoprevention and regulation overproduction of NO on pathogenic conditions. The mechanism of the inflammatory effects, however, must be evaluated through various parameters in the induction cascade of NO production.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.90-91
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• 2000

The physiological systems that control blood fluidity are both complex and elegant. Blood must remain fluid within the vasculature and yet clot quickly when exposed to nonendothelial surfaces at sites of vascular injury. There are two principle mechanisms to control a delicate balance in higher organisms (Davie & Ratnoff, 1964). Present evidence suggests that the intrinsic pathway play an important role in the growth and maintenance of fibrin formation in the coagulation cascade while a second overlapping mechanism, called the extrinsic pathway, is critical in the initiation of fibrin formation. Coagulation factors is in two mechanisms, and in order to clot blood, they are activated by a cooperation with $Ca^{2+}$, phospholipid and vitamin K etc. For example, the human placental anticoagulant protein (PAP of PAP- I), which is a $Ca^{2+}$ -dependent phospholipid binding protein (Funakoshi et al., 1987) inhibited the activity of factor Xa, so that it prolonged fibrin formation. We wondered whether any other protein was involved in regulation of the coagulant system as an anticoagulant protein from natural organisms. Natural agents would have not harmful side-effects in comparision with chemically synthesized materials such as warfarin, aspirin, phenindione, etc.. But anticoagulant agents from natural, especially marine organisms have hardly been researched except for polysaccharides from marine algae. (omitted)

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권10호
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• pp.4117-4135
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• 2020

Due to the angle of view, illumination and scene diversity, real-time dynamic face detection and recognition is no small difficulty in those unrestricted environments. In this study, we used the intrinsic correlation between detection and calibration, using a multi-task cascaded convolutional neural network(MTCNN) to improve the efficiency of face recognition, and the output of each core network is mapped in parallel to a compact Euclidean space, where distance represents the similarity of facial features, so that the target face can be identified as quickly as possible, without waiting for all network iteration calculations to complete the recognition results. And after the angle of the target face and the illumination change, the correlation between the recognition results can be well obtained. In the actual application scenario, we use a multi-camera real-time monitoring system to perform face matching and recognition using successive frames acquired from different angles. The effectiveness of the method was verified by several real-time monitoring experiments, and good results were obtained.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권8호
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• pp.416-422
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• 2006

With the increasing demand for renewable energy, distributed power included in fuel cells have been studied and developed as a future energy source. For this system, a power conversion circuit is necessary to interface the generated power to the utility. In many cases, a high step-up dc/dc converter is needed to boost low input voltage to high voltage output. Conventional methods using cascade dc/dc converters cause extra complexity and higher cost. The conventional topologies to get high output voltage use flyback dc/dc converters. They have the leakage components that cause stress and loss of energy that results in low efficiency. This paper presents a high boost converter with a voltage multiplier and a coupled inductor. The secondary voltage of the coupled inductor is rectified using a voltage multiplier and series-connected with the boost voltage of primary voltage of the coupled inductor. Therefore, high boost voltage is obtained with low duty cycle. Theoretical analysis and experimental results verify the proposed solutions using a 300W prototype.

• 대한조선학회논문집
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• 제36권2호
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• pp.1-8
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• 1999

선저에 부착된 공기공동에 의한 실용 선박의 저항감소 효과를 조사하기 위하여 예인수조에서 충주호 유람선에 대한 저항실험을 수행하였다. 여러 가지 형상의 공기공급 노즐에 대해서 선저에 부착된 공기공동의 관측과 저항 계측이 수행되었으며 이로부터 적절한 공기공급 노즐의 형상을 결정하였다. 선박의 빌지부 근처에서의 공기누출을 억제하기 위하여 선박의 길이방향으로 공기유출막이 스트립을 공기공급 노즐의 양 측면에 부착하였다. 또한 두 개의 공기공급 노즐을 설치하여 두 개의 공기공동을 연속하여 발생시킬 수 있었으며 이로부터 더욱 큰 저항감소 효과를 얻을 수 있었다. 효율 측면에서는 공기공급에 필요한 에너지를 고려하더라도 설계속도에서 10% 이상의 에너지절감 효과를 얻을 수 있었다.

• 대한전자공학회논문지
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• 제20권6호
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• pp.6-10
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• 1983

본 논문에서는 레지듀 연산(residue arithmetic)을 사용하여 디지탈 필터를 실현하는 한 가지 방법을 제시 하였다. 기존의 레지듀 디지탈 필터가 비교적 적은 비트 수를 갖는 신호만을 처리할 수 있었던 것에 비해, 여기서는 비트 슬라이스 알고리즘[1]의 원리를 적용함으로써 보다 많은 비트 수를 갖는 신호를 처리할 수 있도록 했으며, 또한 레지듀 가감산 및 승산은 연산표에 의해서 고속으로 수행될 수 있으므로 이를 이용하여 비트 슬라이스 알고리즘의 단점인 융통성 (flexibility)의 문제를 해결하였다. 실제로 종속 접속형 4차 버터워즈 저역통과 디지탈 필터를 구성하여 실험함으로써 이와 같은 사실들을 입증할 수 있었다.

• 대한전자공학회논문지
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• 제27권11호
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• pp.126-134
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• 1990

CMOS VLSI 기술에서 고속으로 데이타를 인식하기 위해서는 비교적 낮은 전달 콘덕턴스와 MOS 소자 장치들의 불균형을 극복하는 것이 중요하다. 그러나 CMOS 소자들의 한계 때문에 VLSI 회로설계는 일반적으로 CMOS 동작에 알맞도록 바이폴라 A/D(analog-to-digital)변환기가 사용되었다. 또한 파이프라인으로 종속 연결된 RSA에 의하여 전압 비교가 이뤄지는 VLSI CMOS 비교기를 설계하였다. 따라서 본 논문에서는 파이프라인으로 연결된 CMOS 비교기와 병합한 A/D 변환기를 설계하였다.