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.

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.

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.

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.

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

음향 장면 분류에서 히트맵 청취 분석

서상원(Sangwon Suh),박수영(Sooyoung Park),정영호(Youngho Jeong),이태진(Taejin Lee) 한국방송·미디어공학회 2020 한국방송공학회 학술발표대회 논문집 Vol.2020 No.7

인공신경망의 예측 결과에 대한 원인을 분석하는 것은 모델을 신뢰하기 위해 필요한 작업이다. 이에 컴퓨터 비전 분야에서는 돌출맵 또는 히트맵의 형태로 모델이 어떤 내용을 근거로 예측했는지 시각화 하는 모델 해석 방법들이 제안되었다. 하지만 오디오 분야에서는 스펙트로그램 상의 시각적 해석이 직관적이지 않으며, 실제 어떤 소리를 근거로 판단했는지 이해하기 어렵다. 따라서 본 연구에서는 히트맵의 청취 분석 시스템을 제안하고, 이를 활용한 음향 장면 분류 모델의 히트맵 청취 분석 실험을 진행하여 인공신경망의 예측 결과에 대해 사람이 이해할 수 있는 설명을 제공할 수 있는지 확인한다.

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

P-chlorophenylalanine의 전처치가 산소중독시 발생되는 경련발작에 미치는 영향

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

유전 및 육종 : MS 마커를 이용한 토종닭 브랜드의 유전적 특성 및 개체 식별력 분석

서상원 ( Sangwon Suh ),조창연 ( Chang Yeon Cho ),김재환 ( Jae Hwan Kim ),최성복 ( Seong Bok Choi ),김영신 ( Young Sin Kim ),김현 ( Hyun Kim ),성환후 ( Hwan Hoo Seong ),임현태 ( Hyun Tae Lim ),조재현 ( Jae Hyeon Cho ),고응규 ( Yeo 한국동물자원과학회(구 한국축산학회) 2013 한국축산학회지 Vol.55 No.3

MS 마커는 가축의 유전적 다양성, 유연관계 및 품종식별의 연구에 있어서 매우 유용하다. 본 연구는 26개의 MS 마커를 이용하여 토종닭 브랜드 2집단(우리맛닭, 한협3호)과 토착종 순계 2집단(화이트 레그흔, 로드 아일랜드 레드)을 대상으로 집단내 및 집단간의 유전적 다양성, 계통유전학적 관계, 유전적 균일성 등을 검증하여 고유 유전자원으로서의 가치 구명 및 개체식별력이 높은 마커를 선별하여 토종닭 브랜드 계육의 생산이력시스뎀에 활용 가능한 기초 자료를 제시하고자 실시 하였다. 대립 유전자형 분석결과 총 191개 중 47개(24.6%)가 지단 특이 대립 유전자였으며, 다형성지수의 평균은 HExp=0.667, PIC=0.630으로 산출 되였다. 공시된 320 수 개체에 대한 요인대응분석(FCA) 결과 4개의 군집을 형성하였지만 2개 토종닭 브랜드 집단은 타 집단에 비해 매우 가까운 거리에 위치하고 있었으며, 집단간의 DA 유전거리 결과 또한 이와 동일했다. 각 집단에 대한 유전적 균일도는 모든 집단에서 94% 이상으로 높았다. 이상의 결과는 2개 토종닭 브랜드 집단은 유전적으로 유사하지만 토종닭 순계 집단과는 유전적인 차이가 크며, 순계 2집단 또한 유전적으로 확연히 분리됨을 증명 할 수 있다. 26개 MS마커 사용시 동일개체 출현확률(PI)은 1.17×10-49였다. 2011년 기준으로 닭 사육수수 149,511,309수를 고려해 PI 값이 높은 마커 9~12개 정도를 선별 및 분석에 이용 한다면 동일개체 출현확률(PI)이 1.14×10-15 에서 7.33×10-20 이므로 개체식벽 및 친자 감별이 가능할 것으로 사료된다. 향후 경제적 효율성을 고려하여 MS 마커 및 mtDNA의 SNP를 기반으로 multiplexing PCR 시스템을 확립을 위한 연구가 이행된다면 토종닭 브랜드육의 생산이력시스템에 적용이 가능할 것으로 판단된다. Microsatellite markers have been a useful genetic tool in determining diversity, relationships and individual discrimination studies of livestock. The level of genetic diversity, relationships among two Korean indigenous chicken brand populations (Woorimatdag: WR, Hanhyup3: HH) as well as two pure populations (White Leghorn: WL, Rhode Island Red: RIR) were analyzed, based on 26 MS markers. A total of 191 distinct alleles were observed across the four chicken populations and 47 (24.6%) of these alleles were unique to only one population. The mean HExp and PIC were estimated as 0.667 and 0.630. Nei`s DA genetic distance and factorial correspondence analysis (FCA) showed that the four populations represented four distinct groups. However, the genetic distance between each Korean indigenous chicken brand (WR, HH) and the pure population (WL, RIR) were threefold that among the WR and HH. For the STRUCTURE analyses, the most appropriate number of clusters for modeling the data was determined to be three. The expected probabilities of identity among genotypes of random individuals (PI) were calculated as 1.17×10-49 (ALL 26 markers) and 1.14×10-15, 7.33×10-20(9, 12 with the highest PI value, respectively). The results indicated that the brand chicken breed traceability system employing the own highest PI value 9 to 12 markers, and might be applicable to individual identification of Korean indigenous chicken brand.

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

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