L-Moment 법을 이용한 지역적 가뭄빈도분포형 결정

강인식,신형우,이종규,박준일 慶尙大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.15 No.-

To quantitatively investigate the nationwide drought characteristics and to comparatively evaluate the drought severity, regional frequency analysis developed from cumulative monthly precipitation series is made for the meteorological stations in each of the 15 subbasins covering the whole nation. The best-fit probability distribution is chosen by the method of frequency analysis made the discordancy measure for each stations, the regional heterogeneous measure and the goodness-of-fit measure, the probability distributions fitted drought precipitation series are multi-parameter probability distributions, The method of L-moments is used to determine the unbiased parameters of each distribution and the best-fit distribution for each subbasin of various durations(4, 6, 9, 12, 15, 18, and 24 months) with return periods of 2, 5, 10, 20, 50, and 100 years are estimated. This study is focused on suggesting the method determines the drought precipitation of the durations and return periods of each regions by the probabilistic analysis.

모멘트법을 이용한 주기적 배열을 갖는 무한 크기의 주파수선택 표면(FSS) 해석

강봉수,강부식,김흥수 제주대학교 공과대학 첨단기술연구소 2003 尖端技術硏究所論文集 Vol.14 No.2

In this paper, infinite frequency selective surface comprised with rectangular plates which are arranged periodically is analyzed using Method of Moment based on Galerkin's method. In analysis, it is assumed that the plates are infinite thin perfect conductors. Based on this assumption, the reflection characteristics of the FSS is compared according to the polarization of plane-wave and the direction of incidence. In the results, the variation of reflection characteristics of the FSS highly depends on the direction of incidence when the polarization of the plane-wave is parallel to the plane of incidence, but the variation is nearly independent upon direction of incidence when the polarization of the plane-wave is perpendicular to the plane of incidence.

21세기 정보사회를 대비한 지방자치단체의 역할

강흥식 인제대학교 김해발전연구소 1997 김해발전연구 Vol.1 No.1

다중 공진 특성을 갖는 프랙탈 안테나에 관한 연구

강부식,김흥수 제주대학교 공과대학 첨단기술연구소 2003 尖端技術硏究所論文集 Vol.14 No.2

Fractal antenna is an antenna using fractal geometry that involves a recursive generating methodology that results in contours with infinitely intricate fine structures. Fractal geometry has space filling properties and self similar structure. In this paper, the fractal antenna's properties that can be utilized to miniaturize antennas and act in multi band are examined and the fractal antennas with Koch curve are farbricated and the characteristics of fractal antennas are measured.

제대 및 신생아 혈중 cytokine(IL₁β, IL6, TNF) 수치의 변화

강진무,김홍식,박인식,이형종 啓明大學校 醫科大學 1993 계명의대학술지 Vol.12 No.3

분만방법에 따른 제대혈과 양수 그리고 감염 및 stress가 있는 신생아혈중과 세포성분을 배양한 상청액의 cytokine치를 ELISA법으로 측정하여 다음과 같은 성적을 얻었다. 제대혈중 IL₁β치는 질식 유도분만때가 질식 자연 분만, 응급 제왕절개 및 계획 제왕절개때보다 유의하게 높았다(p<0.001). 신생아 혈중 IL₁β치는 감염이 동반된 경우와 stress가 동반된 경우에 높았으며, 감염이 동반되었을 때가 stress보다 더 높게 나타났고, 저체중 출생아에서 높았다. 계획 제왕절개시의 제대혈 IL₁β치는 양수보다 낮았다. 질식자연 분만시 제대혈 세포상청액의 IL₁β 혈장치보다 높았고, 양자간에 유의한 상관관계를 보였다(r=0.92, p<0.05). 감염이 동반된 신생아에서 IL₁β치는 혈장치가 높은 경우 세포 상청액치는 낮고, 혈장치가 낮은 경우 세포 상청액치는 높았다. IL6는 감염이 있는 신생아 혈장과 세포 상청액, 양수 등에서 검출되었다. TNF는 감염이 있는 신생아 세포 상청액 8례중 3례에서 측정되었다 The cytokines, interleukin-1β(IL₁β), interleukin-6(IL6) and tumor necrosis factor(TNF) are important mediators of host response to stress and infection. Impaired immune reaction and febrile responses to the infection in newborn period may result from abnormal cytokine regulation and there were difference in the responses between newborn and adult due to the different cytokine regulation system. To investigate the cytokine regulation in different circumstances of the delivery and newborn conditions, the measurement of the levels of IL₁β,IL6 and TNF in cord blood, amniotic fluid and the blood of the newborn were performed, using enzyme linked immunosorbent assay(ELISA,R&D Co.). Cytokines of the supernatant of incubated cellular pellet were also measured. Cord blood IL₁β level was significantly higher in induced vaginal delivery than that of the normal vaginal, emergency, and elective cesarian section delivery(p<0.001). Plasma IL₁β level of the newborn with infection or stress was elevated and the level was higher in infection than that of the newborn with stress during delivery. Premature baby had higher level than normal newborn. Cord blood IL₁βlevel was lower than that of amniotic fluid in elective cesarian section delivery. In normal vaginal delivery, IL₁βlevel of the cellular supernatant was higher than that of the plasma and showed good correlation(r=0.92, p<0.05). In newborn with infection, plasma IL₁βlevel was high in the cases with low supernatant level and the plasma level was low in the cases with high supernatant IL₁β. IL6 was detcted from the plasma and cellular supernatant of the newborn with infection and the amniotic fluid. TNF was detected in cellular supernatant of 3 among 8 newborn with infection.

5중 오류정정 (31,21) RS 부호의 효율적인 복호 알고리듬

염흥열,강경식 순천향대학교 부설 산업기술연구소 1998 순천향 산업기술연구소논문집 Vol.3 No.3

RS 부호의 복호 기법은 전체 통신 시스템의 성능 및 복잡도에 큰 영향을 미친다. 지금까지 RS 의 복호 기법은 다양한 방법에 있으나 Euclid 알고리듬과 변환복호기법을 이용한 복호 기법은 오류정정능력이 큰 복호 기법으로 널리 적용되고 있다. 본 논문에서는 오류정정능력이 5이상인 RS 부호의 복호 알고리듬에 적용될 수 있는 효율적인 복호 알고리듬을 제시하고, 이를 이용하여 5중 오류 정정 (31,21) RS 부호기 및 복호기를 설계한다. Efficient decoding algorithm which is applicable to the error correcting coding circuit for wireless mobile communication system is presented. By using the proposed decoding algorithm, the pair of encoder and decoder are designed for (31,21) RS codes with 5-error-correcting capability.

항공기용 제트엔진에 대한 가변구조 제어기 설계에 관한 연구

임흥식,이강웅,김학봉 한국항공대학교 1992 論文集 Vol.30 No.-

본 논문에서는 작동점에서 선형화하여 얻은 터보 제트엔진의 선형 모델에 대한 가변구조제어시스템을 설계하였다. 슬라이딩모드에서 발생하는 채터링을 제거하기 위하여 새로운 스위칭영역 설정방법을 제시하고 이 영역내에서 연속제어 입력이 가해지도록 하였다. 제안된 알고리즘을 적용하여 작동점에서 스텝함수로 변하는 명령을 따르도록 하였으며, 컴퓨터 시뮬레이션을 통하여 결과를 보였다. In this paper a variable structure controller is designed for the aircraft jet engine model which is linearized in operating point. In order to eliminate the chattering in the sliding mode, a new method of the switching region is proposed and a discontiuous control input is substituded by a continuous one in this region. The proposed control algorithm is applied to the engine model plant in the operating point. Simulation results show that good system responses for step changes of the command are obtained.

Ti-6Al-4V의 저주기 고온염 피로균열성장거동에 관한 연구

우흥식,강봉수,김봉철 東國大學校 1999 東國論叢 Vol.38 No.-

Fatigue crack growth behaviour of Ti-alloy, Ti-6Al-4V were investigated in air and salt corrosive environments. The temperatures which was tested were room temperature and 200℃. Fatigue crack growth rate is known to be fast for formation of corrosive product by impregnation Ti-Alloy with salt solution in hot salt environment. For the effect on corrosion fatigue crack growth behabiour of sale corrosive transformation in air and high temperature of region Ⅱ, fatigue crack grwoth rate in air atmosphere had a little gap to both case, 200℃ and room temperature. However, it showed very fast tendency especially in salt corrosive atmosphere, and it was remarkably accelerated in 200℃ high temperature salt environment. When ΔK was approximately 30MPa√m, fatigue crack growth rate had a little difference between at room temperature and at 200℃ high temperature, however in case of salt corrosive environment, the former was 3.5 times faster and the latter for 16 times than air environment respectively. For salt corrosive environment of microstructure (Ⅲ), the fatigue life in 200℃ salt corrosive environment was shorter than that of in air, reached to only 32%.

심혈관계를 침범한 Wilms종양 1례

김흥식,강진무,차홍대 啓明大學校 醫科大學 1986 계명의대학술지 Vol.5 No.2

This report is a presentation of a rare case of wilms tumor involved rigth kidney, right renal vein, ingerior vena cava and right atrium seen in a girl of 4 years of age, who presented abdominal distention and hematuria for last 1 month. Ultrasonography of the abdomen revealed dilatation of right renal vein and inferior vena cava and mass iesion in the right atrium was seen on Echocardiogram. A mass of the right upper quadrant which invaded inferior vena cava and right atrium through the right renal vein was found on CT scan of the chest and abdomen, which suggested the wilms tumor of right kidney propagated into the right renal vein, inferior vean cava and right atrium as a tumor thrombosis. A brief review of literature was made.

Ti-50.1at.%Ni합금의 변태거동에 미치는 시효처리의 영향(Ⅰ)

우흥식,박성범,강봉수,김성진 한국안전학회 2004 한국안전학회지 Vol.19 No.4

This study investigated the effects of aging on the transformation behavior of Ti-50.lat.% Ni alloy by means of differential scanning calorimetry. It was found that aging in the temperature range of 350℃~550℃ induced complex transformation behavior, involving the R-phase and multiple-stage martensitic transformation. Usually aged Ni-rich NiTi alloys undergo martensitic transformation on cooling from high temperatures in two step : B2 to R and then R to B19' (normal behavior). But under certain ageing conditions, the transformation can also occur in three or more step(unusual multiple step behavior). In the present study we use differential scanning calorimetry(DSC) for a systematic investigation of the evolution of transformation behavior with ageing temperature and time.