적응 MMSE 전왜곡기를 이용한 OFDM-16QAM의 HPA 비선형성 보상

곽의식,서종수 연세대학교 산업기술연구소 1997 논문집 Vol.29 No.2

Being a multi-carrier modulation scheme OFDM system has a better BER performance than single carrier modulation system in multipath fading environment. Since the envelope of OFDM signal is not constant, when OFDM signal is amplified by High Power Amplifier (HPA) in non-linear mode, OFDM system suffers serious performance degradation due to ICI (Interchannel interference), ISI (Intersymbol interference) and spectral regrowth. In this paper an adaptive MMSE (Minimum mean square error) predistorter is proposed in order to compensate for the performance degradation of OFDM-16QAM signal caused by HPA nonlinearity. Our result shows that the adaptive MMSE predistorter compensates for the HPA nonlinearity, and significantly improves the BER performance of nonlinearly amplified OFDM-16QAM system.

주정 중독 흰쥐에서 총담관 결찰이 혈청 및 간의 α-D-및 β-D-Glucosidase 활성에 미치는 영향

곽춘식,김여희,임종술 啓明大學校 醫科大學 1993 계명의대학술지 Vol.12 No.2

이 연구는 간담도 질환시 음주의 해로움에 대한 생화학적 배경의 일단을 밝히고자 시행한 실험으로서 급성 및 만성 주정 중독을 시킨 흰쥐에게 총담관결찰로 담즙울체를 야기시켜 혈청과 간의 α-D-glucosidase와 β-D-glucosidase의 활성도를 측정한 것이다. 쥐간의 lysosomal α-D-glucosidase 활성도는 총담관만 결찰한 군보다 만성 주정 중독 후 총담관을 결찰한 군이 총담관 결찰 후 7일부터 14일까지 덜 현저한 증가를 나타내었다. 총담관을 결찰한 군과 만성 주정 중독 후 총담관을 결찰한 군에서 간의 lysosomal acid β-D-glucosidase 및 cytosolic broad specificity β-D-glucosidase 활성도를 비교했을 때는 양군간에 별 차이가 없었다. 총담관을 결찰하고 14일 경과한 군과 총담관 결찰 14일 후 급성 주정 중독을 시킨 군에서 간의 lysosomal α-D-glucosidase, lysosomal acid β-D-glucosidase 및 cytosolic broad specificity β-D-glucosidase의 활성도를 비교했을 때는 양군간에 별 차이가 없었다. 쥐 혈청의 lysosomal α-D-glucosidase와 broad specificity β-D-glucosidase 활성도를 총담관을 결찰한 군과 만성 주정 중독 후 총담관을 결찰한 군을 비교했을 때는 만성 주정 중독 후 총담관을 결찰한 군이 총담관만 결찰한 군보다 더 현저한 증가를 나타내었다. 그러나 총담관을 결찰하고 14일 경과한 군과 총담관 결찰 후 급성 주정 중독을 시킨 군에서 혈청의 이들 효소의 활성도를 비교했을 때는 broad specificity β-D-glucosidase만 총담관 결찰 후 14일 경과한 군보다 총담관결찰 14일 후 급성 주정 중독을 시킨 군이 그 활성도가 더 높았다. 이들 성적 중에서 혈청의 lysosomal α-D-glucosidase와 broad specificity β -D-glucosidase의 활성도가 총담관만 결찰했을 때 보다 만성 주정 중독 후 총담관을 결찰했을 때 더 증가되고 아울러 혈청의 broad specificity β-D-glucosidase 활성도가 총담관 결찰 14일 후 급성 주정 중독을 시켰을 때는 총담관만 결찰한 후 14일 경과했을 때보다 그 활성도가 높은 것은 만성 주정 중독 및 급성 주정 중독시 담즙울체가 야기되면 담즙울체만 있을 때보다 간손상이 증폭된다는 것을 나타낸 결과라 생각되며 이성적은 간손상의 증폭으로 간에서 이들 효소의 누출일 증가된 것이라 할 수 있다. 따라서 이 성적은 담즙울체로 간손상이 있을 때는 음주를 해서는 안된다는 것을 뒷받침하는 자료라 하겠다. The activities of the liver and serum α-D and β-D-glucosidase were studied for cholestasis induced by common bile duct ligation and chronic ethanol intoxication developed, or cholestasis after acute ethanol intoxication for manifestation of the biochemical background of alcohol intoxication in hepatobiliary disease. The groups that received common bile duct(CBD) ligation after being chronically intoxicated with ethanol showed a marked increase at the 7th and 14th day after the ligation in the liver lysosomal α-D-glucosidase activities. However, the activities showd a lower degree than groups of the CBD lgation. The groups that received CBD ligation after being chronically intoxicated with ethanol showed a slight increase after the ligation in the liver lysosomal acid β-D-glucosidase and cytosolic broad specificity β-D-glucosidase activities, and the same was seen in the groups of the CBD ligation. At the 1.5th and 24th hours after the acute intoxication with ethanol which was done after 14 days of the CBD ligation, the rats showed a considerable increase in the liver lysosomal α-D-glucosidase, lysosomal acid β-D-glucosidase and cytosolic broad speciticity β-D-glucosidase activities, and the same was seen in the group sacrificed on the 14th day after the CBD ligation. The groups that received CBD ligation after being chronically intoxicated with ethanol showed a marked increase after the ligation in the serum lysosomal α-D-glucosidase and broad specificity β-D-glucosidase activities. However, the activities showed a far higher degree than groups of the CBD ligation. For the groups of acute intoxication with ethanol done after 14 days of the CBD ligation, the serum broad specificity β-D-glucosidase activities increased markadly, but the activities showed a higher degree than the group with the 14th day after the CBD ligation. In summary, especially, when the acute and chronic ethanol intoxication with cholestasis occurred, the serum lysosomal α-D-glucosidase and broad specificity β-D-glucosidase are higher than in cholestasis because of increased liver cell damage, which causes the enzyme to leak into the blood in great quantity. Accordingly, these results will be the data supporting the alcoholic drink is enzymologically harmful in hepatobiliary disease.

용혈성 요독 증후군 부검 1예

채종민,곽정식,임재원 大韓法醫學會 1996 대한법의학회지 Vol.20 No.1

We experienced an autopsy case of hemolytic uremic syndrome. Over 75% of cases occur in children with intestinal infection with verocytotoxin-producing E.coli. The disease is one of the main causes of ARF in children. It is characterized by the sudden onset, usually after a gastrointestinal or flu-like prodromal episode of bleeding manifestations(especially hematemesis and melana), severe oliguria, hematuria, a micro-angiophathic hemolytic anemia, and prominent neurologic changes?

3차원 데이터의 Photon Map Rendering 기법에 대한 비교 연구

김종서,조동식,곽훈성 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

The needs about presentations of realistic image have been gradually increased the technical development and importance in the study of computer graphics. With the development of hardware enabling high-resolution image, we suggest to express more natural and accurate image in rendering. This paper presents photorealistic rendering algorithm that embodies accurate image such as photo. With relative evaluation among photorealistic renders that are used in present, we compare base and efficiency and also analyze the interface and application environment. Based on these our comparison, analysis and experimentation, this paper verifies quality and render-speed as important points in renderer. We expect that our experimental results will be used as comparative data in many rendering works.

Windows CE기반에서 GameAPI를 이용한 효율적인 게임 컴포넌트 설계 및 구현

조동식,김종서,이명재,곽훈성 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

Recently, many variable mobile contents enter the stage according as increase of mobile device user. Mobile game among many mobile contents have being developed from the main projects. But mobile Game must design to set variable condition of which, small hardware, variable platform, and etc. Therefore we must design the fast small game and the fast update game. In this paper, we designed efficient game components on PDA with the Windows CE platform and modulated the function of game. Therefore we can less term of game development, and reuse the components to fit each game architecture. Also we modulated the function of GameAPI, is game API of Windows CE, that can make real-time game and high level game. In the last of paper, we implemented the shooting Game made use of our Game Components and studied the faculty of Game Components.

1995년도 대구지역 법의 부검 통계

채종민,이숙희,정민희,곽정식 大韓法醫學會 1996 대한법의학회지 Vol.20 No.1

This is a statistical observation by authors based on data of deaths brought to department of forensic medicine, Kyungpook National University School of Medicine for medicolegal autopsy by all of law enforcement agencies in Taegu area during the year of 1995. The report aims to reveal facts on various causes of death in Taegu area in attempt to analyse 205 cases statistically. The following are the summary of results ; 1. The total numbers of autopsy were 205 cases, of these 121 cases (58%) were males and 83 cases (40%) were females. 2. The violent deaths were 135 cases (66%) and the natural deaths were 63 cases (31%) and unknown cases were 7 (3%). 3. The percentage of autopsied cases with 30's age group was 28.2% (the most), 20's was 17.2%, 40's was 13.8%, 10's was 13.8%... in violent deaths. The percentage of autopsied cases with 30's age group was 31%, 40's was 20%, 20's was 20%, 50's was 15.5%...in natural deaths. 4. For the violent deaths, the percentage deaths due to injury was 52.9%, asphyxia was 29.8%, intoxication was 10.4% and abnormal temperature(hypothermia or fire) or electrocution was 6.7%. 5. For deaths due to injuries, the percentage of deaths due to blunt injury was 45.7%, sharp force injury was 29.5%, fall was 17.1%. and traffic accident was 7.1%. 6. For the natural deaths, 60 cases were recorded and the death due to the disese of the cardiocascular system was taking the most of the total percentage with 53%. 7. For deaths due to injuries, the percentage of accidental death was 57.3%, homicide was 22% and suicide was 14.7%. 8. 31 subjects (51.7%) of 128 violent deaths have positive blood alcohol concentrations (0.05% and above) , and 8.1% of natural deaths were associated with alcohol intake. 9. For deaths by medical dispute, 7 cases were recorded and deaths combined with operation were taking the most of the total percentage with 43%.

원발성 폐고혈압으로 인한 우측 심부전 부검 1 예 : Report of an autopsy case

이승철,곽정식,이상한,채종민 大韓法醫學會 1996 대한법의학회지 Vol.20 No.1

Primary pulmonary hypertension is a rare disease and diagnosed only when the underlying causes are undetermined. Pulmonary hypertension is caused largely by an increase in pulmonary vascular resistance and is most frequently chronic pulmonary obstructive diseases, recurrent pulmonary emboli or antecedent heart diseases. We experience and report a case of primary pulmonary hypertension. The pulmonary changes show atherosclerosis in all the pulmonary arteries, medial hypertrophy, intimal proliferation and fibrosis and plexiform lesion. Plexiform lesion is characteristic in the histological diagnosis of primary pulmonary hypertension when there is no other associated disease, such as liver cirrhosis, tricuspid cardiac shunts and portal vein thrombosis.

리티움 이온 고체전해질 CO₂센서

송갑득,서무교,곽종식,이덕동 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

Carbon dioxide gas sensor, which has inner heater, is fabricated using Li ionic electrolyte as raw material which is systhesized by sol-gel method. It has either Au electrode or Pt electrode as the metal electrode of sensing electrode part. Sensing characteristics for carbon dioxide gas and interference effect for carbon monoxide gas and hydro carbon gases are investigated. The sensors using Au electrode and Pt electrode show sensitivity about 25 mV/decade and 26 mV/decade for the variation of carbon dioxide gas concentration, respectively. The sensor using Au electrode shows more exellent selectivity compared to that using Pt electrode for carbon monoxide gas and hydro carbon gases.

고체전해질형 CO₂가스 감지 소자의 제작 및 그 동작 특성

서무교,송갑득,곽종식,이덕동 경북대학교 센서기술연구소 1994 센서技術學術大會論文集 Vol.5 No.1

The raw material of solid electrolyte type CO_(2) sensor was synthesized using tetraethoxysilane, lithium methoxide, zirconium n-propoxide, and tributyle phosphate as precursors, this process was carried out at 60℃ in N_(2) ambience. The prepared material was dried and crushed into powder, and it was pressed into disk type samples. These samples were sintered at 9000 -1100℃ for 50 hours. The physical characteristics of the samples were investigated by TG/DTA, SEM and XRD. The solid electrolyte type CO_(2) sensor was fabricated and its operational characteristics were measured. The sensing characteristics of the sensor shows about 86 mV/decade for the variation of CO_(2) concentration.

자연정화공법에 의한 소형 하수처리장치 개발을 위한 최적 깊이 및 호기ㆍ협기 비율

서동철,박미령,곽내운,황하나,이홍재,조주식,허종수 한국환경농학회 2006 한국환경농학회지 Vol.25 No.1