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.

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

P-chlorophenylalanine의 전처치가 산소중독시 발생되는 경련발작에 미치는 영향

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

우리나라 은행부문의 시스템 리스크 측정

서상원 ( Sang Won Suh ) 한국금융연구원 2011 금융연구 Vol.25 No.2

Accurate measurement of systemic risk is required to efficiently implement financial regulation policies for financial stability. In this paper, we measure systemic risk of Korean banking sector by employing a new method proposed by Suh (2011) which extends existing methods based on option pricing approaches in order to effectively capture realistic features in banks` asset return dynamics and their correlations.12) Merton`s (1974) structural approach considers an equity as a European call option written on a firm`s asset value with the strike price of the matured debt amount. The method employed in this paper also regards an equity as a European call option, but the option is written on the net asset value (i.e., asset value minus debt amount) with the strike price of zero, departing from the usual structural approach. This deviation allows a realistic feature that banks` liabilities (as well as asset) continuously and randomly change because of their role of financial intermediation, while the usual structural approach assumes a fixed debt amount at maturity. The method models individual bank`s net asset value to depend on an observable common factor which is realistically featured with time-varying volatility. This feature enables not only individual bank`s net asset values but also their correlations to have time-varying volatility. Furthermore, it greatly facilitates estimation because the common factor is constructed as an observable variable and therefore allows bank-by-bank estimation. Systemic risk is measured with (i) the proportion of the number of default (or distressed) banks among all banks and (ii) the proportion of the debt amounts of default (or distressed) banks among all banks. We utilize the method to measure s ystemic risk of Korean banking sector from March 1999 to August 2010. The Korean banking sector is populated with ten to twelve banks during the sample period. We found that the Korean banking sector showed a sharp increase in the systemic risk during the recent global financial crisis period. Debt-weighted systemic risk level was lower than equal-weighted systemic risk level, which indicates that large banks are less susceptible to financial distress than small banks. The common factor prove its importance in measuring systemic risk. In particular, ignoring the common factor might lead to significant underestimation of the systemic risk.

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.

조리종사원의 비언어적 커뮤니케이션이 서비스품질지각, 고객만족, 신뢰, 고객충성도에 미치는 영향

서상원(Sang-Won Suh),류을순(Eul-Soon Ryu) 한국관광연구학회 2016 관광연구저널 Vol.30 No.2

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.

비선형 특징추출 기법에 의한 머리전달함수 ( HRTE ) 의 저차원 모델링 및 합성

서상원(Sang Won Suh),김기홍(Ki Hong Kim),김현석(Ki Hong Kim),김현빈(Hyun Suk Kim),이의택(Ee Taek Lee) 한국정보처리학회 2000 정보처리학회논문지 Vol.7 No.5

For the implementation of 3D Sound Localization system, the binaural filtering by HRTFs is generally employed. But the HRTF filter is of high order and its coefficients for all directions have to be stored, which imposes a rather large memory requirement. To cope with this, research works have centered on obtaining low dimensional HRTF representations without significant loss of information and synthesizing the original HRTF efficiently, by means of feature extraction methods for multivariate data including PCA. In these researches, conventional linear PCA was applied to the frequency domain HRTF data and using relatively small number of principal components the original HRTFs could be synthesized in approximation. In this paper we applied neural network based nonlinear PCA model (NLPCA) and the nonlinear PLS regression model (NLPLS) for this low dimensional HRTF modeling and analyze the results in comparison with the PCA. The NLPCA that performs projection of data onto the nonlinear surfaces showed the capability of more efficient HRTF feature extraction than linear PCA and the NLPLS regression model that incorporates the directional information in feature extraction yielded more stable results in synthesizing general HRTFs not included in the model training.