자율신경계의 활성도 측정을 위한 Data Acquisition System의 개발 및 임상응용

신동구,박종선,김영조,심봉섭,이상학,이준하 영남대학교 기초/임상의학연구소 2001 Yeungnam University Journal of Medicine Vol.18 No.1

Background: Power spectrum analysis method is a powerful noninvasive tool for quantifying autonomic nervous system activity. In this paper, we developed a data acquistion system for estimating the activity of the autonomic nervous system by the analysis of heart rate and respiratory rate variability using power spectrum analysis. Materials and methods: For the detection of QRS peak and measurement of respiratory rate from patient's ECG, we used low-pass filter and impedance method respectively. This system adopt an isolated power for patient's safety. In this system, two output signals can be obtained: R-R interval(heart rate) and respiration rate time series. Experimental ranges are 30∼240 BPM for ECG and 15∼80 BPM for respiration. Regults: The system can acquire two signals accurately both in the experimental test using simulator and in real clinical setting. Conclusion: The system developed in this paper is efficient for the acquisition of heart rate and respiration signals. This system will play a role in research area for improving our understanding of the pathophysiologic involvement of the autonomic nervous system in various disease states.

높은 받음각에서 양항 특성의 향상을 위한 공력 보조 PANEL에 관한 연구

신동진,이봉준 한국항공운항학회 1994 한국항공운항학회지 Vol.2 No.-

항공기에 사용되는 2차 조종면은 플랩, 탭, 스포일러 등 여러 종류가 있으며 이중 spoiler는 공력제어 기능을 가지고 항공기의 조정성에 영향을 미치는 조종면으로 속도 감속이나 옆놀이 조종용으로 사용된다. 본 연구에서는 비행제어용 spoiler 기능과 고양항력을 얻을 수 있는 새로운 장치인 고양항력 panel에 대한 공력특성 및 비행제어 특성에 대하여 연구하였다. 이러한 고양항력 panel은 재래식인 spoiler가 양력을 감소시키고 항력만 증가시키는 장치인데 반하여 양력과 항력을 동시에 증가 시킬 수 있는 새로운 장치로서 날개의 앞전 뒷면에 스팬방향으로 설치하여 슬롯효과를 발생시킴으로써 최대 양력 받음각에서 앞전에서의 박리를 막아 비행기의 착륙시 양력의 급작스러운 감소로 인한 불안정성을 감소시키게 된다. 본 논문에서는 직사각형 날개 및 FA-200모형의 날개위에 고양항력 panel을 설치하여 풍동실험 및 수치계산을 한 결과를 기술하였다. 실험결과 직사각형 날개의 경우 고양항력 panel의 위치는 날개의 앞전에 설치할 경우 고받음각에서 실속지연의 효과와 함께 후방실속의 특성을 향상 시킬 수 있으며, 항력의 증가로 인한 스포일러 효과를 얻을 수 있다. 양항비특성은 고양항력 panel을 날개의 앞전에 설치하고, 그 폭이 시위의 1/5이고, 붙임각 θ가 10°, 높이가 시위의 3/20일 때 받음각 18° 이후에서 우수한 특성을 나타내었다. FA-200 모형의 경우 옆놀이 모멘트계수는 받음각이 작을 때 고양항력 panel의 슬롯간격과 붙임각이 작을수록 커지나 받음각이 커지면 붙임각이 커짐에 따라 증가함을 알 수 있다. 또한 키놀이 모멘트계수는 크게 변화하지 않으나 항력 특성은 고양항력 panel의 붙임각이 증가함에 따라 증가하였다. 고양항력 panel의 붙임각이 큰 범위에서(θ=10°) 공기력의 증가는 고양항력 panel의 시위가 날개시위의 30%이고 슬롯의 폭이 날개시위의 10%일 때 증가하는 결과를 얻을 수 있다.

입자 크기에 따른 ITO 가스 센서의 가스 감지 특성

신동원,김봉철,전희권,이상태,이덕동,허증수 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

KOSDAQ시장에서 IPO기업의 초기 비정상수익에 관한 연구

辛奉俊,李埈碩 東亞大學校 大學院 2005 大學院論文集 Vol.30 No.-

This study analyses all the Initial Public Offerings(IPOs) firms in KOSDAQ Market during the period 2000.1.1 to 2002.12.31, in order to investigate whether anomaly phenomenon related with the IPOs exists in KOSDAQ Market, and understand anomalies' form. Furthermore we attempt to observe IPOs effect influencing stock price and provide a valuable piece of information about variables influencing the IPOs effect. This study composed as follows: First, we observe shape of the stock price and Cumulative Abnormal Return (CAR) after IPOs. Second, we examine whether there is a difference in IPOs' price among industry category(venture firm, general firm), public offering size, and premium rate. Lastly we run multivariate regression to analysis whether result is consistent with empirical evidence presented on KOSDAQ Market. The results of this study are stated as following: 1) We found that there is a positive relationship between listing of IPOs and Early Abnormal Return(EAR). 2) The venture firm's CAR is higher than General firm's. There is an inverse proportion relationship between premium rate and CAR, when one diminishes the other increases. We run a set of multiple regressions models using 4 dependent variables (premium rate, age of IPOs companies, public offering size, and beta) and 1 dummy variable. The regression indicates EAR CAR_(0)'s explanatory variables PRM(LSIZE), BETA, D_(1) are statistically significant, LSIZE, the BETA are significant in CAR_(1,250). The results show the factors influencing CAR are dissimilitude according to dependent variables. This study has shed some considerable light to empirical evidence on IPOs effect in KOSDAQ Market. Nonetheless our study based on EAR, we omitted the other empirical evidence on IPOs long-term performance, and only researched a specific market. The other limitation is that empirical period is very short. If the data is more sufficient, we expect to analyze IPOs stock price's time series for more than 1 year.

의학적 입장에서 본 명상의 기능

신용욱,권준수,함봉진 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.4

Beyond the target of scientific researches, meditation is now one ofthe main tools for palliative and integrative medicine in Westem society. Despite theof valuable heritages of meditation in Korea, meditation is not considered to have clinical implications as in Westem medical society. It is partly due to the fact that while the mysterious aspect of meditation has been emphasized, a large number of scientific researches on meditation had not been known to Korean medical society. The authors reviewed several studies that examined the clinical effect of meditation and speculated its possibility as a method of clinical intervention.

흰쥐에서 염화비닐 폭로수준에 따른 소변내 thiodiglycolic acid 농도의 변화

왕승준,차봉석,노재훈,신동천,김명수,전근재 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : It is the objective of this research to identify the variation of thiodiglycolic acid(TdGA) in urine with vinyl chloride monamer(VCM) exposure levels through methylation. Methods : After rats were exposed to vinyl chloride monomer of 4 levels, 0㎎/㎥, 50㎎/㎥, 150㎎/㎥, 500㎎/㎥, respectively, of which urine was sampled in each sampling time of 0 hour, 2 hours, 4 hours, 8 hours, 16 hours, 36 hours, 48 hours. After urine had been methylated with diazomethane in the preliminary experiment and the peak of 146 m/z had been verified, the main experiment was done. Results : In the variation of TdGA with sampling times, concentration of TdGA increased rapidly in 4 hours and then decreased after 8 hours. When the variation of urinary TdGA concentration in urine according to exposure level of VGM was verified through Kruskal-Wallis statistical method at each sampling time, the significant increment with the exposure levels at 2 hours, 4 hours, 8 hours after exposure was clarified. Conclusion : TdGA concentration in urine with increment of VCM exposure level increased, especially significantly at 2 hours, 4 hours, 8 hours of sampling time.

남강댐 유역에서의 HEC-HMS 모형의 적용성

박준일,신형우,조봉철,장영태 경상대학교 생산기술연구소 2000 生産技術硏究所論文集 Vol.16 No.-

In order to find out the runoff characteristics in Nam River Dam basin, hydrological data such as rainfall, water level, and discharge, have been collected and measured. Using the collected and measured data for the study area during 1990-1999, hydrological parameters were estimated. The HEC-HMS(Hydrologic Modeling System) model was used to review the applicability of flood hydrographs and the results of simulation were compared to the observed data and Stroge Function Method for several flood hydrographs in this study. From the results of analysis, the following conclusions were obtained: First, the HEC-HMS model showed better results for the capabilities of regenerating flood hydrographs Second, the fluctuation shape of flood hydrographs for the rainfall distribution concentrated on head have been shown peak time to be relatively short for other rainfall distribution. Third, for forecasting and warning of flood occurrence in future, it is necessary that the existing hydrological data were made good and hydrological data were accumulated more. Also, using the HEC-HMS model to complement the Storage Function Method, it is possible that forecasting and warning flood occurrence is progressive in Nam River Dam.

65세 이상 노인 급성 심근경색증 환자의 사망에 영향을 미치는 인자들

정봉기,양금열,손준혁,주시내,남홍우,전용덕,이홍순 대한노인병학회 2001 대한노인병학회지 Vol.5 No.2

경로탐색을 위한 GIS 네트워크 분석 시스템의 구현

이신준,양성봉,최윤철 연세대학교 산업기술연구소 1999 논문집 Vol.31 No.2

Path finding is one of the basic functions provided in the network analysis system of a geographic information system(GIS). A GIS network analysis system analyzes and models geographic networks, and enables user to solve a variety of problems concerning geographic networks such as finding a most efficient travel route. In path finding there are two types of routing problems. One is to find a shortest route between two nodes. The other is to find an optimum route among many points, which is known as the traveling salesman problem. We have implemented our GIS network analysis system for path finding on the Gothic GIS system. The implemented system consists of the optimal path finder and the multiple path finder. And the system in this paper also solves routing problems efficiently in GIS networks.

GIS에서의 효율적인 최단경로탐색 알고리즘

이신준,양성봉 연세대학교 산업기술연구소 1999 논문집 Vol.31 No.2

Finding a shortest route from a point to another is one of the basic functions provided in the network analysis of a geographic information system(GIS). A network in GIS consists of the set of nodes and the set of links. There are many examples for geographical networks such as streets, highways, railways, communication lines, electric lines, pipelines, rivers, etc. In this paper, we present four efficient algorithms for finding a shortest path in a network. Each algorithm utilizes the coordinates of nodes to reduce the search space and keeps a tree-like data structure, called a path tree, to find a better route than the path found in the previous step of the algorithm. Our algorithms can be classified into two types depending on the search directions used in the algorithms: one-way search and two-way search methods. Each search method can be further divided into two methods depending on whether the depth-first search(DFS) or the breadth-first search(BFS) is used. Overall, we have four methods: one-way DFS-DFS, one-way DFS-BFS, tow-way DFS-DFS, and two way DFS-BFS Each method has been compared with each other along with Dijkstra's algorithm. The experimental results have shown that two-way DFS-BFS outperformed others in almost all cases.