흰쥐에서 배측 봉선핵의 전기자극이 췌장의 외분비기능에 미치는 영향

서상원,박형진,Suh, Sang-Won,Park, Hyoung-Jin 대한생리학회 1990 대한생리학회지 Vol.24 No.2

The present investigation was performed to see a possible influence of the dorsal raphe nucleus (DRN) on pancreatic exocrine secretion in anesthetized rats since the DRN had been known to exert a regulatory mechanism on sympathetic activity which was known to be very important for pancreatic exocrine secretion, particularly in rats. Twenty-nine Sprague-Dawley rats fasted for 24 hours were anesthetized by i.p. injection of 1 g/kg of urethane. The pancreatic duct was cannulated to collect pancreatic juice while bile juice was diverted into the jejunum. The duodenopyloric junction was tightly ligated. After surgery for collection of pancreatic exocrine secretion and recording of carotid blood pressure, a coaxial electrode was stereotaxically inserted in the DRN with a guide of a brain atlas. And then, electrical stimulus of biphasic square wave with 2 v, 2 msec, 40 Hz was applied on the electrode for 10 minutes. Pancreatic volume flow and protein output secreted in 10 min were measured. Either bilateral cervical vagotomy or spinal cord transection at the level of $C4{\sim}C5$ was performed 20 min prior to stimulation of the DRN. 1) Electrical stimulation of the DRN resulted in significant (p<0.05) increase in pancreatic volume flow and protein output. These stimulatory effects were not affected by cervical vagotomy but completely abolished by cervical cord transection. 2) Electrical stimulation of the DRN also resulted in significant (p<0.05) rise of blood pressure of the carotid artery. The hypertensive effect was not affected by cervical vagotomy but completely abolished by cervical cord transection. The results strongly suggest that the DRN, a part of the central serotonergic system, could exert a stimulatory influence on pancreatic exocrine secretion by increasing the sympathetic activity in anesthetized rats.

Neumann 더미헤드를 사용한 머리전달함수(HRTF)의 측정

서상원 ( Sang Won Suh ),김재우 ( Jae Woo Kim ),이명진 ( Myung Jin Lee ),김용완 ( Yong Wan Kim ) 한국감성과학회 1998 춘계학술대회 Vol.1998 No.-

시스템공학연구소 감성공학연구부에서는 수행중인 멀티미디어 컨텐트용 입체음향처리 S/W개발과제의 일환으로 머리전달함수(Head-Related Transfer Function, HRTF)의 측정을 수행하였다. 본 논문에서는 무향실에서의 HRTF 데이터 측정 과정 및 얻어진 HRTF들에 대한 음상정위청취 평가 결과에 대해 설명한다. 청취 평가에서는 피험자들이 측정된 HRTF와 MIT Media Lab의 KEMAR 더미헤드 HRTF를 사용하여 각 방향에 대해 필터링된 음원을 듣고 음상정위 주관평가를 시행하였는에, 측정된 HRTF를 사용하여 양호한 음상정위 결과를 얻을 수 있음을 확인하였다.있음을 확인하였다.

Closed- form Physical Densities: An Extension to a Wider Class of Risk-Neutral Densities

서상원 ( Sang Won Suh ) 한국증권학회 2008 한국증권학회 발표논문집 Vol.2008 No.1

금융 시스템리스크를 감안한 금융기관 자기자본 규제정책

서상원 ( Sang Won Suh ) 한국금융학회 2010 금융연구 Vol.24 No.1

금융 감독정책은 금융 시스템 안정과 거시경제적 안정을 동시에 추구하면서 결정된다. 그런데 특히 경제불황기에는 두 목표간에 상충관계가 존재하기 때문에 감독정책 결정에서 당국의 세심한 주의가 필요하다. 본 연구의 목적은 정책당국의 감독정책 효과를 금융 시스템 및 거시경제적 안정측면에서 분석할 수 있는 모형을 제시하고 이를 통해 두 목표간 상충관계에 대한 구체적 정보를 제공함으로써 감독정책 결정에 도움을 주는데 있다. 주요 분석결과로는 (ⅰ) 심각한 경기불황기에 거시경제 안정을 위한 감독정책은 금융 시스템리스크를 높일 위험이 크며 (ⅱ) 은행들의 대출방식에 따라 감독정책의 효과가 달라질 수 있다는 점에 유의하여야 하고 (ⅲ) 경기불황기에 자기자본 적립의무를 경감시켜 은행대출을 증가시키려는 정책은 바젤Ⅰ에 비해 바젤Ⅱ에서 효과가 작게 나타나며 (ⅳ) 현재 경기불황이 심각한 상황에서 미래에도 경제상황이 개선되지 않으면 거시경제 안정을 위한 감독정책은 자칫 미래에 시스템리스크를 크게 상승시키는 부작용을 초래할 위험이 있다는 점 등을 들 수 있다. Financial systemic risk issues have become important since global financial crisis of 2008. Financial regulatory and supervisory policies had largely focused on how to maintain the soundness of individual financial institutions based on the belief that sound individual financial institutions guarantee against financial systemic risk. In particular, Basel Ⅱ changes bank capital regulation in such a way that bank credit risks are not severely affected by changes in borrowers` creditworthiness. However, the bank capital regulation in Basel Ⅱ does not take financial systemic risk into account but mainly concerns the soundness of individual banks. Moreover, Basel Ⅱ may induce procyclicality problem because loose bank capital regulation enables bank lending to grow further in boom periods while bank lending contracts due to tight bank capital regulation in recession periods. On the one hand, following Basel Ⅱ bank capital regulation, a financial regulator may be faced with procyclicality problem. On the other hand, if a regulator adjusts bank capital regulation so as to dampen business cycle fluctuations in recession periods, it may worsen the soundness of individual banks. This demonstrates the trade-off between macroeconomic stability and financial stability from a financial regulation policy perspective. This paper addresses financial regulator`s decision problem which should take both macroeconomic stability and financial stability into account. I present a model to analyze the effects of financial regulation policy on bank lending and financial systemic risk. This model can provide financial regulators with informations about the trade-off between macroeconomic stability and financial stability and therefore help them to form regulation policy. The model presented in this paper can analyze the trade-off between macroeconomic stability and financial stability and also is designed to incorporate many realistic assumptions. For example, the model assumes multiple banks, and each bank has heterogeneous borrowers with different creditworthiness. Credit ratings are assigned according to internal methods and change due to common or idiosyncratic shocks. The model is basically designed for a single period but extends for multi-periods without difficulty. Main findings are: (ⅰ) Regulation policies for enhancing macroeconomic stability might deteriorate financial stability in a severe recession period. (ⅱ) The effects of regulations may be dependent upon banks` lending behavior. (ⅲ) The effect of reducing capital requirement upon bank lending in a recession period is greater under Basel II than under Basel I. (ⅳ) In a dynamic analysis, regulation policies for enhancing macroeconomic stability might lead to deteriorated financial stability in the future, if current recession cannot rebound quickly.

연구발표 진행표 : A 발표장 : 정규화 기준값 산정에 관한연구

서상원(Sang Won Suh),이건모(Kun mo Lee),허영채(Young Chae Huh),하상선(Sang Sun Ha) 한국전과정평가학회 1999 한국전과정평가학회 정기총회 연구논문집 Vol.1999 No.0

수익률곡선 정보를 활용한 기대수익률 추정 및 금리정책 효과 분석

서상원 ( Sang Won Suh ),최재훈 ( Jae Hun Choi ),박충원 ( Choong Won Park ) 한국금융연구원 2014 금융연구 Vol.28 No.1

We propose a method to extract information about market expectations of future yields using market yield curve. In addition, we empirically analyze the effects of market participants` expectations on the interest rate channel To this end we first set up a theoretical term-structure model and then estimate it with Korean market yield data. After verifying the validity of the model with empirical results, we then use it to assess the effects on market yields of the demand on domestic bonds from foreign investors which have showed wide fluctuations since 2007. Next, we propose a method to extract information about market expectations of future policy rate as well as market yields using market yield curve. We then investigate into the accuracy of those market expectation- based forecasts. In addition to this theoretical term-structure model approach, we also use regression-based approaches to estimate market expectations implied with market yield curve. Using these estimates of market expectations about monetary policy, we then decompose actual policy rate changes into the expected portions and the unexpected ones. This decomposition enables us to analyze the relative importance of the two components in the interest rate channel of This paper contributes to the literature by providing an analysis of monetary policy shock with respect to the interest rate channel of monetary policy which has not been extensively studied yet. In addition, growing effects of foreign investors on bond yields have been rarely studied, which is another contribution of this paper. This paper also provides empirical results for the forecasting ability of market expectations extracted from market yield curve. Our empirical results show that market expectations extracted from yield curve turn out to be useful for yield forecasting. Secondly, after decomposing changes in policy rates into unexpected changes and expected ones, we found that the unexpected changes in policy rate exert impacts no less than the expected changes in policy rate. Lastly, by conducting counter-factual exercises, we found that market yields have been significantly affected by foreign investors` demand on Korean bonds, which has been suspected from the fact that foreign investors` Korean bond holdings has greatly increased since 2007 and then fluctuated widely during the recent global financial crisis period.

P-chlorophenylalanine의 전처치가 산소중독시 발생되는 경련발작에 미치는 영향

서상원 ( Sang Won Suh ),김해준 ( Hae Joon Kim ) 국군의무사령부 1993 대한군진의학학술지 Vol.24 No.1

바젤 2 도입과 은행의 대출행태 분석

서상원 ( Sang Won Suh ) 한국금융연구원 2006 금융연구 Vol.20 No.2

본 연구에서는 은행대출 결정에 관한 이론모형을 제시하였다. 특히 바젤 II 도입이 은행대출에 미치는 영향을 분석하기 위해 차주의 신용도 등이 모형에 포함되었으며, 또한 경제의 일부문에만 국한된 신용도 충격 발생에 따른 영향을 분석할 수 있도록 경제 내에 부문을 도입하였다. 주된 이론적 분석결과로는 첫째, 바젤 II 도입에 대한 QIS(Quantitative Impacts Study) 결과, 바젤II로 이행하면서 필요자기자본 규모가 증가하더라도 차주대체의 효과가 클 경우에 은행대출 규모가 반드시 감소하는 것은 아니다. 또한 바젤II로 이행하면서 어떤 부문에 대한 필요자기자본 규모가 감소하여도 해당 부문에 대한 은행대출 규모가 반드시 증가하는 것은 아니다. 둘째, 일부문에만 발생한 신용도 충격이 은행대출에 미치는 영향은 현행 BIS협약 하에서와 바젤II 하에서 서로 다르다. 셋째, 바젤II 하에서 은행대출의 경기순응성을 완화하기 위해 감독당국이 필요자기자본 적립비율을 변동시키는 정책을 사용할 경우 전 부문에 정책을 사용하는 것보다는 신용도 충격이 발생한 부문에 선택적으로 사용하는 것이 보다 효과적일 수 있다. This paper proposes a model of banks` lending behavior which incorporates obligor`s credit rating and introduces sectors in the economy to analyze the effects of Basel II on bank lending. Main analytical results are as follows: First, even if the minimum required capital is shown to increase from the Quantitative Impacts Study for the adoption of Basel II, it does not necessarily mean the decrease of bank lending. Moreover, even though the minimum required capital of a sector in the economy decreases while adopting Basel II, it does not necessarily imply the decrease of bank lending for the sector. Second, the effects of credit risk shocks in a sector on bank lending under the current Accord are qualitatively different with those under Basel II. Third, when regulators change the required capital ratio to mitigate the procyclicality of bank lending under Basel II, it would be more effective to implement it only into the sectors hit by credit risk shocks rather than into all sectors.

드럼세탁기의 감성품질 측정 시스템

서상원(Sang-won Suh),이창구(Changgoo Lee) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

도어락 스위치(Door-lock switch)는 드럼세탁기, 식기 세척기등 회전이나 열이 발생되어 작동 할 때 임의로 열지 못하도록 하는 가전제품에 쓰이는 도어안전잠금장치로 드럼세탁기에서는 없어서는 안 되는 중요한 부품 중의 하나이다. 드럼 세탁기 도어는 소비자가 사용 할 때 항상 느낌을 가지는 부분으로 안전성과 동시에 감성이 뒤따르는 부품이기도 하다. 본 논문은 드럼세탁기의 도어에 감성과 관련된 요소들을 조사하였으며, 도어락 스위치의 기구적인 구조들을 파악한 뒤 드럼세탁기에 장착 하였을 때 열림력, 닫힘력을 측정할 수 있는 지그와 소프트웨어를 제작하여 측정한 힘의 그래프를 분석하고 사용자에 의해 평가한 후, 드럼세탁기 도어락 스위치의 구조에 따른 감성에 차이점을 찾아보고 최적의 설계를 위한 요소를 제시하였다.

CNN 알고리즘을 이용한 체커스위치 불량 검출 시스템 개발

서상원(Sang-Won Suh),고요한(Yo-Han Ko),유성구(Sung-Goo Yoo),정길도(Kil-To Chong) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.12

Various automation studies have been conducted to detect defective products based on product images. In the case of machine vision-based studies, size and color error are detected through a preprocessing process. A situation may arise in which the main features are removed during the preprocessing process, thereby decreasing the accuracy. In addition, complex systems are required to detect various kinds of defects. In this study, we designed and developed a system to detect errors by analyzing various conditions of defective products. We designed the deep learning algorithm to detect the defective features from the product images during the automation process using a convolution neural network (CNN) and verified the performance by applying the algorithm to the checker-switch failure detection system. It was confirmed that all seven error characteristics were detected accurately, and it is expected that it will show excellent performance when applied to automation systems for error detection.