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.

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.

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.

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

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

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.

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.

실생활 음향 데이터 기반 이중 CNN 구조를 특징으로 하는 음향 이벤트 인식 알고리즘

서상원(Sangwon Suh),임우택(Wootaek Lim),정영호(Youngho Jeong),이태진(Taejin Lee),김휘용(Hui Yong Kim) 한국방송·미디어공학회 2018 방송공학회논문지 Vol.23 No.6