MP-2에서 타원형 편미분 방정식 병렬계산

김형중,이용호 江原大學校 産業技術硏究所 1994 産業技術硏究 Vol.14 No.-

일반적으로 2차원 Poisson 방정식을 풀기 위해 유한 차분법을 이용하여 tridiagonal block Toeplitz 선형방정식을 얻는다. 이 선형방정식의 독특한 형태를 활용하기 위해 Lyapunov 방정식으로 변화시킨 다음 이산정형변환(DST)을 이용해서 대각선 행렬로 만들면 계산이 용이해진다. 또 DST는 FFT를 이용해 계산할 수 있으므로 고속 계산이 가능하다. FFT를 병렬로 처리하기 위해 프로세서가 4,096개인 SIMD 컴퓨터 MP-2에서 시뮬레이션했다. 본 논문에서는 알고리즘 유도, 매핑 및 시뮬레이션 결과를 제시했다. We can get a tridiagonal block Toeplitz linear system by the finite difference approximation of 2-D Poisson equation. To exploit the nice property of this linear equation, we transform the equation into'a Lyapunov equation and apply DST(discrete sine transform) to get diagonal matrix based Lyapunov equation. DST can be performed using FFT, which enables high-speed computaion. All the computations are performed on an SIMD parallel computer, the MasPar MP-2 with 4,096 processing elements. In this paper, parallel algorithm, mapping method of the algorithm onto the MP-2, and timing results are presented.

중합효소연쇄 반응법에 의한 인형거대세포바이러스(human cytomegalovirus)의 신속한 검출

김의종,오명돈,박기호,신형식,이환종,김남중,최강원 대한감염학회 1996 감염 Vol.28 No.4

목 적 : 인형거대세포바이러스(HCMV)는 면역 저하 환자에서 폐렴, 망막염, 간염 등 치명적인 감염증의 원인이다. 전통적인 세포 배양법으로 HCMV를 분리하기까지는 1주에서 4주가 걸리므로 이 바이러스에 의한 질환이 의심되는 경우 신속한 진단법을 이용한 진단이 바람직하다. 저자들은 한국에서 분리되는 야생주 HCMV를 검출하는데 중합효소 연쇄 반응법을 이용할 경우의 진단적 유용성을 알기 위하여, 전통적인 세포배양법으로 HCMV가 분리된 검체를 이용하여 중합효소 연쇄 반응법의 특이도와 민감도를 평가하였다. 방 법 : 국내 야생주 HCMV 15주, 그리고 전통적인 바이러스 배양법으로 HCMV가 분리된 소변 15검체를 대상으로 중합효소 연쇄 반응을 실시하였다. 중합효소 연쇄 반응은 Towne주의 immediate early antigen의 유전자에서 유리된 primer MIE와 AD169주의 immediate early antigen의 유전자에서 유리된 primer IE를 이용하였다. 증폭 산물은 겔 전기영동 후 EtBR으로 염색하여 자외선 하에서 관찰하였다. Primer IE에 의한 증폭산물은 또한, DNA blot hybridization 방법으로 확인하였다. 결 과 : 1) 국내 HCMV 야생주 15주를 대상으로 중합효소 연쇄 반응을 한 결과 primer IE를 이용한 경우에는 100%(15/15)에서 177bp의 증폭 산물이 관찰되었고, 이들 증폭 산물은 모두 probe IE와 보합 결합되었다. primer MIE를 이용한 경우에는 93%(14/15)에서 435bp의 증폭 산물이 관찰되었다. 2) 세포 배양법으로 HCMV가 분리된 소변 15검체를 대상으로 primer IE를 이용하여 중합효소 연쇄 반응을 한 결과 direct gel analysis 법으로는 73%(11/15)에서, 보합 결합법으로는 87%(13/15)에서 관찰되었다. Primer MIE를 이용한 경우에는 direct gel analysis법으로 87%(13/15)에서 435bp의 증폭 산물이 검출되었다. 결 론 : Primer IE와 MIE를 이용한 중합효소 연쇄 반응법은 국내 야생주 HCMV를 신속히 검출하는데 유용한 검사법이다. Background : Human cytomegalovirus(HCMV) can cause pneumonitis, hepatitis, retinitis and other serious diseases in the immunocompromised patients. It takes 1 to 4 weeks to diagnose HCMV infection by conventional virus culture. Therefore, when HCMV diseases are suspected, a rapid diagnostic method such as polymerase chain reaction(PCR), antigen assay or shell vial culture is desirable. We evaluate the sensitivity and specificity of a PCR for the rapid detection of HCMV wild strains in Korea. Methods : We used 2 sets of primers ; primer IE and primer MIE derived from the sequence for immediate early gene of AD169 strain and Towne strain, respectively. Fifteen clinical isolates of HCMV, suspended in MRC-5 cells, were amplified by PCR. Fifteen urine specimens which were positive for HCMV by conventional virus culture were also amplified. Amplification products were analyzed by polyacrylamide gel electrophoresis. The products from PCR with primer IE were also identified by DNA blot hybridization. Results : PCR using primer IE gave the PCR products in all of the 15 HCMV wild strains. All of these were hybridized with probe IE. When primer MIE were used, 93%(14/15) of the wild strains showed amplified bands by direct gel analysis. When the urine specimens were amplified by PCR with primer IE, amplified bands were seen in 73%(11/15) by direct gel analysis ; 87%(13/15) by hybridization method. When primer MIE were used, 87%(13/15) of the urine specimens showed the PCR products by direct gel analysis. Conclusion : Polymerase chain reaction with primer IE and MIE may be a specific and sensitive diagnostic method for rapid detection of HCMV wild strains in Korea.

원격탐사를 위한 병렬계산 기법

김형중,장태정,김희원,김형수,이정문,장순자 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

원격탐사에 사용되는 편미분방정식을 고속으로 풀기 위한 기법을 프로그래밍하고 성능을 향상시킬 수 있는 방법을 제시했다. 미지수가 30만개 이상되는 복소수(non-Hermitian) 행렬의 해를 구하는 프로그램을 작성했다. 이 프로그램은 C와 PVM에 기반을 두고 있다. 수렴속도를 향상시키기 위해 대각 스케일링을 이용했다. 통신속도의 개선을 위해 데이터 압축 기법을 이용했다. 수렴속도를 측정 제시함으로써 실제 문제 적용에 참고할 수 있다. Network-based computing with cluster of personal computers or workstations recently has become an important and successful technique. Network-based computing enables fast computation and resolves short of storage with computers on the desks. Cluster of inexpensive computers offers them aggregated computing power and storage to challenge very large-scale problems. Iterative solvers are used for the large sparse linear systems. Preconditioners accelerate the rate of convergence of the iterative solvers. However, parallelization accelerate the rate of convergence of the iterative solvers. However, parallelization of preconditioners is far from satisfaction so far. Thus, the simplest diagonal scaling is a good alternative for improved convergence and easy parallelization. In order to reduce communication overhead, a data compression technique is considered. Data communication time can be reduced at the cost of convergence rate. MATLAB simulation result is given in this paper. This method is effective to cluster of computers connected through slow networks.

뇌동맥류성 지주막하 출혈 후 지연허혈신경결함에 대한 평가에 있어서의 Acetazolamide단일광자방출전산화 단층촬영술의 역할

김형중,김은영,하윤,윤승환,박형천,박현선 The Korean Neurosurgical Society 2004 Journal of Korean neurosurgical society Vol.35 No.2

2축 서보시스템을 위한 위치제어장치 설계

김기택,김형중,장석호 江原大學校 産業技術硏究所 1991 産業技術硏究 Vol.11 No.-

In this study, we design a position controller or two axis servo system.The position controller performs numerical control(NC)to DC or AC servo motor or step motor, and also has a digital input output sequence capability. The control program composed of position and sequence command, which is called channel, is programed easily and user interactivtively. And it is interpreted and the straight line and are position command iinterpolated . We develop the Z80 microprocessor based system and the software with assembly and Clanguage, and also PC based graphic simulator for the debugging and educational purposes.

버스 네트워크에서의 최적 부하배분 알고리듬

김형중,Ghose, D. 강원대학교 정보통신연구소 1997 정보통신논문지 Vol.1 No.-

A bus network of communicating processors is anlayzed. The processors in the network are equipped with front-end processors. The problem is to determine an optimal partitioning of a matrix to compute matrix-vector multiplication so that these individual parts can be computed independently in several processors in minimum time. Some important results are proved analytically using the closed form solution.

강산 및 강알칼리 음독에서 냉각 용액을 사용한 희석 요법과 중화 요법의 가능성

이중의,송형곤,김동훈,권운용,곽영호,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: There is no effective treatment modality for caustic agent ingestion. Dilution and neutralization are prohibited because of the risk of secondary thermal injury. This experiment is designed to evaluate the amount of dilution and neutralization heat and to gauge the applicability of dilution and neutralization therapy using cold solutions to suppress the peak temperature. Methods: This is an in-vitro chemical experiment. HCl, CH3COOH, NaOH, and NH4OH are selected as representatives of strong and weak acids and strong and weak alkali, respectively. 20℃, 11.6M, 5.8M, and 2.9M solutions of each acid and alkali are made and mixed using a magnetic stirrer at a room air temperature of 28℃. The peak temperature, the duration above 40℃, and the heat amount are measured or calculated. Results: When a 11.6M HCl or NaOH solution is diluted with same amount of water, 32 or 18cal. per mL of HCl or NaOH is produced, respectively. HCl produces a significant peak temperature, but NaOH does not. The lower the concentration, the lower the amount of heat production. 11.6M CH3COOH and NH4OH solutions don't produce dilution heat.11.6M and 5.8M solutions of all acids and alkali produce destructive neutralization heat. However, 2.9M solutions produce neutralization heat which might be controllable. When a 11.6M HCl or NaOH solution is neutralized with a -10℃ 2.9 M NaOH or HCl solution, respectively, the peak temperature produced is below 40℃ and seems to add little thermal damage to viable tissue. Conclusion: Dilution and neutralization with a cold solution in cases of strong acid or alkali ingestion is a promising method to avoid thermal injury.

컴퓨터비젼을 이용한 알루미늄 캔재 이어링률 자동 측정 시스템 개발

이용중,김형조,이양범 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

The main purpose of this paper is the development of the system which measures the earing rate of aluminum CAN with the CCD camera. In order to optimize imput image, the image object was segregated and the position of the image grasped. In the pre-processing the edges were detected by the Robert mask after improving the definition of image by the histogram equalization. The height of four each ear and angles which occur due to the characteristics of the aluminum CAN are measured manually with the digital vernier calipers in the industrial ground and in the case of the velocity, these require 30 seconds at least by three times measurement per height of one direction of the aluminum. But it took 0.02 seconds when this system was applied. Therefore this system is proven the satisfactory efficiency and reliability as compared to the control result of in industrial ground.

웨이블릿 영역에서 상관함수를 이용한 3-State 블라인드 디지털 워터마크

최용수,김형중 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

The content's authentication is very important in the field of Digital Multimedia Contents which is based on the Internet. There are several methods to perform the authentication. The Watermarking is the one of those methods. This paper's every process is based on the image application. The proposed watermarking method has the 3-State information and performs the embedding and the detection without reference Content. when we authenticate the Owner Information, it uses correlation function. The special feature is embedding the watermark depends on the original contents and using the DWT(Discrete Wavelet Transform) Domain when it is applying the SS(Spread Spectrum) method. therefore, certain extra probability of error will be reduced. and DWT is more faster than other transform method(DFT, DCT etc). When we use N size image, the computation can reduce from O(N·logN). and we can hide some more information per bit. In this experiment, We used some general signal processing (such as Noise Addition, Compression, Scaling etc.) as the Attacks.

신아세포종에 병발된 폐 색전증 1예 보고

박용욱,김형중,서중석 大韓法醫學會 1999 대한법의학회지 Vol.23 No.1

Wilms' tumor is the most common urinary tract neoplasm and one of the most frequent solid abdominal malignant tumors of childhood, usually diagnosed between the ages of 2 and 5 years. Typically, it is manifested as an asymptomatic unilateral or upper abdominal mass. Abdimonal pain after some traumatic incident, fever, anemia, hematuria and hypertension are other patterns of presentation. In a considerable number of these patients, pulmonary metastases are present at the time of primary diagnosis. But, the initial presentation of acute pulmonary tumor emboli without surgical manipulation is very rare. We describe a sudden unexpected infantile death case diagnosed as pulmonary tumor embolism preexisting Wilms' tumor. To our knowledge, this is the initial autopsy presentation of Wilms' tumor with tumor embolism as sudden and unexpected death in Korea.