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      • A New Pipelined ROM DCT architecture with 8 pixels /colck throughput rate

        Nam,Seung Hyun,Lee,Yong Surk,Lee,Moon Key,Lee,Tae Young 延世大學校 電波通信共同硏究所 1995 電波通信論文誌 Vol.1 No.1

        A high throughput rate 8*8 DCT architecture using ROM multipliers and pipelining is proposed in this paper. With this new architecture, a 64 point one dimensional DCT can be done in 8 clock cycles with latency of 6 cycles. The proposed architecture has the following features. (1)ROM multipliers are utilized instead of conventional multiplication operation. (2)Data bit width has no effect on the architecture performance. (3)Excluding transposition memory cycles, the 64 point two dimensional DCT transformation can be done within 16 cycles. (4)To spread calculation burden over all pipeline stages, the pipelined structure introduced into the ROM accessing operation. (5)Hardware overhead is not proportional to the increased performance. A marvelous performance of 400 mega pixels per second at 50 MHz is obtained.

      • Clinical Performance of Whole-Body 18F-FDG PET/Dixon-VIBE, T1-Weighted, and T2-Weighted MRI Protocol in Colorectal Cancer

        Lee, Soo Jin,Seo, Hyo Jung,Kang, Keon Wook,Jeong, Seung-Yong,Yi, Nam-Joon,Lee, Jeong Min,Chung, June-Key,Edmund Kim, E.,Paeng, Jin Chul,Cheon, Gi Jeong,Lee, Dong Soo Wolters Kluwer Health, Inc. All rights reserved. 2015 Clinical nuclear medicine Vol.40 No.8

        PURPOSE: The aim of this study was to investigate the clinical performance of whole-body F-FDG PET/Dixon–volume-interpolated breath-hold examination (Dixon-VIBE), T1-weighted, and T2-weighted MRI protocol in patients with colorectal cancer. PATIENTS AND METHODS: A total of 59 patients with colorectal cancer were enrolled in this study. Each patient had one of the following clinical conditions: initial stage before therapy, stage after neoadjuvant therapy, suspicious colorectal liver metastases, and colorectal liver metastases after chemotherapy. Fourteen patients had primary colorectal cancer, whereas 38 patients had a total of 132 hepatic lesions, 53 lesions existed before chemotherapy, and 79 lesions appeared after chemotherapy. The primary stage and metastases images were obtained using our PET/Dixon-VIBE/T1/T2 MRI protocol and were analyzed by 2 nuclear medicine physicians. Diagnostic accuracy was compared with contrast-enhanced MRI images, which were based on surgical pathology results. RESULTS: The sensitivity of our imaging protocol for primary colorectal cancer was 100% (14/14). T and N stage both showed 92.9% (13/14) accuracy. Of all 132 hepatic lesions, 115 metastatic lesions were analyzed, and 17 benign lesions were excluded (6 were during pretreatment cases, and 11 were during posttreatment cases). In pretreatment metastatic lesions (n = 47), the sensitivities of our protocol and dedicated MRI were 95.7% (45/47) and 100% (47/47), respectively. In posttreatment lesions (n = 68), sensitivities of our protocol and dedicated MRI were 75% (51/68) and 91.2% (62/68), respectively. CONCLUSIONS: Whole-body PET/Dixon-VIBE/T1/T2 MRI protocol is clinically useful for TNM staging and chemonaive hepatic metastasis in colorectal cancer.

      • SCOPUSKCI등재

        H215O PET을 이용한 정상인의 삽화기억 부호화 및 인출 중추 뇌기능지도화

        이재성,남현우,이명철,안지영,박광석,이동수,정준기,이상건,장명진 대한핵의학회 2000 핵의학 분자영상 Vol.34 No.1

        Purpose: Episodic memory is described as an 'autobiographical' memory responsible for storing a record of the events in our lives. We performed functional brain activation study using H215O PET to reveal the neural basis of the encoding and the retrieval of episodic memory in human normal volunteers. Materials and Methods: Four repeated H215O PET scans with two reference and two activation tasks were performed on 6 normal volunteers to activate brain areas engaged in encoding and retrieval with verbal materials. Images from the same subject were spatially registered and normalized using linear and nonlinear transformation. Using the means and variances for every condition which were adjusted with analysis of covariance, t-statistic analysis were performed voxel-wise. Results: Encoding of episodic memory activated the opercular and triangular parts of left inferior frontal gyrus, right prefrontal cortex, medial frontal area, cingulate gyrus, posterior middle and inferior temporal gyri, and cerebellum, and both primary visual and visual association areas. Retrieval of episodic memory activated the triangular part of left inferior frontal gyrus and inferior temporal gyrus, right prefrontal cortex and medial temporal area, and both cerebellum and primary visual and visual association areas. The activations in the opercular part of left inferior frontal gyrus and the right prefrontal cortex meant the essential role of these areas in the encoding and retrieval of episodic memory. Conclusion: We could localize the neural basis of the encoding and retrieval of episodic memory using H215O PET, which was partly consistent with the hypothesis of hemispheric encoding/retrieval asymmetry. (Korean J Nucl Med 2000;34:10-21)

      • SCOPUSKCI등재

        관상동맥 질환에서 우회로 수술 전 Tl - 201 휴식 - 24시간 지연 심근 관류 SPECT를 이용한 심근생존능의 평가

        이명철(Myung Chul Lee),정준기(June Key Chung),서정돈(Jung Don Seo),이동수(Dong Soo Lee),고창순,이원우(Won Woo Lee),윤석남(Seok Nam Yoon),김기봉(Ki Bong Kim) 대한핵의학회 1996 핵의학 분자영상 Vol.30 No.4

        N/A To assess contribution of T1-201 rest-24 hour delay redistribution in detection of viable myocardium, we studied the predictive value of this redistribution in 17 patients who performed rest-24 hour delay perfusion SPECT before bypass surgery. Regional wall motion was compared with gated SPECT in 10 patients and echocardiography in 7 patients before and after bypass surgery. Rest and 24 hour delayed uptakes were scored from 0 (normal perfusion) to 3 (defect). In rest SPECT, 56 segments showed perfusion decrease. Thirty four segments(61%) improved after surgery and were defined as viable. Nineteen(34%) segments had more uptake of T1-201 at 24 hour delay, and the other 37 segments did not. In 81%(25/31) of segments with mildly decreased perfusion, wall motion after bypass surgery improved, 57% (8/14) of segments with severely decreased perfusion improved, and 9%(1/11) of segments with defects improved. In 14 among 19 segments which had more T1-201 uptakes at 24 hour delay, wall motion was improved (positive predictive value of redistribution: 74%). 20 among 37 segments which had persistent decreases in rest-24 hour redistribution improved and 17 did not(negative predictive value: 46%). Segments having severe perfusion decrease or defects showed improved wall motion after surgery in 64%(7/11), if it had redistribution at delay. Segments with either mildly decreased uptake in resting or rest-delayed redistribution showed improved wall motion in 76%(32/42). Among the 14 segments which showed improvement in wall motion, 10 had partial reversibility in stress-rest images and the other 4 had persistent perfusion defects in stress-rest images. These 4 segments were found viable only with rest-24 hour delayed perfusion SPECT. We concluded that rest T1-201 uptake or redistribution at 24 hour delay should be referred as an evidence to warrant postoperative improvement of abnormal wall motion and we could predict mycardial viability with preoperative rest-24 hour delay perfusion SPECT in the segments with rest perfusion decreases

      • 국내 콩에서 발생하는 바이러스 병해의 발생 상황

        이영훈 ( Yeong Hoon Lee ),임승택 ( Seung Taek Lim ),윤영남 ( Young Nam Yoon ),전명기 ( Myeong Gi Jeon ),윤홍태 ( Hong Tae Yun ),고종민 ( Jong Min Ko ),이수헌 ( Su Heon Lee ),이기운 ( Key Woon Lee ),백인열 ( In Youl Baek ) 한국콩연구회 2013 韓國콩硏究會誌 Vol.29 No.1

        국내 콩에서는 SMV, SbDV, AMV, CMV, CPMV, SYMMV, SYCMV와 PSV가 보고되었다. 과거 이들 바이러스 중에서 SMV가 심각한 피해를 입히고 있으며, 90%이상 우점하는 것으로 보고되었다. 하지만, 최근 SMV의 발생률은 50%정도로 낮아졌으며, SYMMV, SYCMV와 PSV 등에 의한 여러 가지 바이러스 병해가 피해를 주고 있는 것으로 확인되었다. 최근 기후 및 재배환경의 변화와 국제 농산물 교역으로 인해 병 발생 양상이 급속하게 변하고 있음을 나타내는 단적인 예인 것이다. 또한, 새로운 매개층과 전염원의 발생으로 신종 또는 미보고 바이러스 발생이 늘어나고 있지만, 콩과 같은 주요 작물의 병해 발생 상황 및 피해 양상 구명에 대한 연구는 미흡한 실정이다. 이러한 이유로 국내 콩에서 발생하는 바이러스 병해의 확인을 위해 8도19지역에서 193점의 시료를 채집하였다. 채집된 시료들은 SMV, SYMMV, SYCMV, SbDV, PSV, BCMV, AMV, PEMV, CMV, CCMV, TSV, BBWV2, BYMV와 CPMV 14종에 대한 정밀 진단을 위하여 각각의 종특이 프라이머를 이용하여 RT-PCR 진단이 수행되었다. 그 결과 채집된 시료의 86%가 바이러스에 감염된 것으로 확인 되었으며, SMV 141, SYMMV 14, PSV 8과 SYCMV 5점이 확인되었다. 대구와 나주에서 채집된 2점의 시료들에서는 SYMMV와 SYCMV가 복합감염 되어있었다. 나머지 미동정 시료에 대한 정밀 분석과 지속적인 발생상황 조사가 이루어 져야 할 것이다. It had been reported that soybean viral diseases are Soybean mosaic virus (SMV), Soybean dwarf virus (SbDV), Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), Cowpea mosaic virus (CPMV), Soybeun yellow rnottle mosaic virus (SYMMV), Soybean yellow common mosaic virus (SYCMV) and Peanut stunt virus (PSV) in Korea. Among these viral diseases, SMV caused severe damage to soybean in Korea, Although SMV occurred more than 90% in the past, recently several viruses such as SYMMV, SYCMV, SbDV and PSV have been reported in Korea, It means that the incidence of viral diseases are changing in soybean. To identify the viruses infecting soybean in Korea, the 193 samples with viral symptoms were collected in 19 areas of 8 provinces. And then the RT-PCR assay was conducted to detect 14 different viruses such as SMV, SYMMV, SYCMV, SbDV, PSV, BCMV, AMV, PEMV, CMV, CCMV, TSV, BBWV2, BYMV and CPMV. The results indicated that about 86% of samples were identified as Virus-infected, Among 193 soybean samples, 141 SMV, 8 PSV, 14 SYMMV, 5 SYCMV were detected. Two samples were coinfected with SYMMV and SYCMV. The rest of them were likely to express the mosaic similar to virus-induced symptoms. Therefore, the identifications of the unknown samples have been performed by the dererminatlon of the nucleotide sequences of the genomic RNAs.

      • SCOPUSKCI등재

        Thallium - 201 심근 단층영상의 정량적 분석

        이명철(Myung Chul Lee),정준기(June Key Chung),안규리(Cu Rie Ahn),이동수(Dong Soo Lee),김상은(Sang Eun Kim),최창운(Chang Woon Choi),고창순,이영우,서정돈,박영배,최윤식,이명묵(Myoung Mook Lee),남기병(Gi Byoung Nam),최기준(Kee Joon Choi),손대원(Dae 대한핵의학회 1991 핵의학 분자영상 Vol.25 No.2

        N/A The purpose of this study was to assess the ability of quantitative Tl-201 tomography to identify and localize coronary artery disease (CAD). The study population consisted of 4l. patients (31 males, 10 females; mean age 55 +- 7 yr) including 14 with prior myocardial infarction who underwent both exercise Tl-201 myocardium SPECT and coronary angiography for the evaluation of chest pain. From the short axis and vertical long axis tomograms, stress extent polar maps were generated by Cedars-Sinai Medical Center prograrn, and the 9 stress defect extent (SDE) was quantified for each coronary artery territory. For the purpose of this study, the coronary circulation was divided into 6 arterial segments, and the myocardial ischemic score (MIS) was calculated from the coronary angiogram. Sensitivity for the detection of CAD (>50% coronary stenosis by angiography) by stress eXtent polar map was 95% in single vessel disease, and 100% in double and triple vessel deseases. Overall sensitivity was 97%<. Sensitivity and specificity for the detection of individual diseased vessels werc, respectively, 87% and 90% for the left anterior descending artery (LAD), 36% and 93% for the left circumflex artery (LCX), and 71% and 70%, for the right coronary artery (RCA). Concordance for the detection of individual diseased vessels between the coronary angiography and stress polar map was fair for the LAD (kappa=0.70), and RCA (kappa=0.41) lesions, whereas it was poor for the LCK lesions (kappa =0.32) There were siginificant correlations between the MIS and SDE in LAD (rs=0. 56, p=0.0027), and RCA territory (rs=0.60, p=0.0094). No significant correlation was found in LCX territory. When total vascular territories were combined, there was a significant correlation between the MIS and SDE (rs=0.42, p=0,0116). In conclusion, the quantitative analysis of TI-201 tomograms appears to be accurate for determining the presence and location of CAD.

      • SCOPUSKCI등재

        내측 측두엽 간질환자와 정상인의 H215O PET 을 이용한 뇌 혈류량 비교

        강은주(Eun Joo Kang),이재성(Jae Sung Lee),남현우(Hyun Woo Nam),이상건(Sang Kun Lee),이동수(Dong Soo Lee),정준기(June Key Chung),이명철(Myung Chul Lee) 대한핵의학회 2002 핵의학 분자영상 Vol.36 No.3

        목적: 본 연구는 내측 축두엽 간질 환자가 국소 혈류 변화를 보이는 두뇌 영역을 H_2^15O-PET를 이용하여 확인하는 것을 목적으로 하였다. 대상 및 방법: 12명의 내측두엽간질 환자 (우측 6명, 좌측 6명)와 6명의 정상인에게 `+` 응시 조건과, 위로 향한 화살표에만 단추를 눌러 반응하는 감각-운동 과제를 수행하면서 H_2^15O-PET을 실시하였다. 각 스캔의 영상 과 SPM99 소프트웨어를 이용하여 화소 분석방법으로 정상인과 환자 집단 사이에 기저 뇌혈류 또는 뇌혈류 증가 정도의 차이를 조사하였다. 결과: 응시기저 조건중에는 우 내측두엽 간질 환자는 좌우 양반구이 후측 도와 오른쪽 전두말단 부분의 혈류가 감소하였다. 같은 조건에서. 좌 내측두엽 간질 환자에서는 왼쪽 전두말단 영역과 측두엽 영역의 혈류가 정상인들보다 감소되었다. 응시조건과 비교하여 감각-운동 과제 중에 혈류가 증가하는 정도를 정상인과 비교하였을 때 우 내측두엽 간질 환자에게서는 왼쪽의 전두엽과 상측두 영역이, 좌 내측두엽 간질 환자들에게서는 우반구의 여러 영역이 저하되었다. 반면 두 환자 집단 모두 왼쪽의 하 두정엽과 전시상핵/뇌궁 연접 영역의 혈류 증가 정도가 정상인집단에 비하여 증가되었다. 결론: H_2^15O-PET으로 측정된 두뇌 국소 혈류 분포를 SPM99을 이용하여 분석함으로써, 단순한 감각 운동 조건 동안의 두뇌 국소 혈류 증가 양상은 물론이고, 응시점을 주시하는 단순 기저 조건 중 측정된 두뇌의 국소 혈류량의 분포에도 내측 간질 환자 집단과 정상인 집단간에 유의미한 차이가 있음이 발견되었다. Purpose: The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H_2^15O-PET. Materials and Methods: 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-bassed analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Results: During the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the nomal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task,rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in left inferior parietal and anterior thalamic/fornix region in both right and left mTLE patients compared to normal controls. Conclusion: Epolepsy induced changes were found not only in relative increase/decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the realtive rCBF distribution during the rest period. (Korean J Nucl Med 2002;36;155-65)

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