Tera 대역 WPAN 통신 시스템

고영채 한국통신학회 2010 정보와 통신 Vol.27 No.2

Tera 대역으로 일반적으로 여겨지는 300 ~ 3000㎓ 대역을 이용하여 무선 근거리 개인 영역 통신(WPAN)에서 20~40Gbps 급의 데이터 통신을 하기 위한 국제 표준화가 현재 IEEE802.15표준화 그룹에서 진행 중이다. 본 논문에서는 표준화의 진행 상항과 더불어 테라 대역의 주파수 할당, 물리계층에서 테라 대역을 이용하여 WPAN이 가능하기 위한 요소 기술로서 빔포밍 기법에 대하여 정리한다. 주파수 할당은 비허가 주파수 대역의 가능성 여부 및 시기 등에 대하여 지난 수년간 테라 대역과 관련되어 ITU에서 발표된 문서들을 요약한다. 테라 대역에서 WPAN을 위한 물리계층의 요소 기술로서는 테라 대역의 주파수 특성인 전파의 직진성 및 거리에 따른 전력 감쇄를 극복하기 위하여 저전력 빔포밍 기술에 대하여 소개한다. 본 논문은 향후 약 5년 후에 표준화가 완성될 것으로 예상되는 시점에서 국내의 통신 관련 연구자에게 초고속 데이터 통신을 가능하기 위한 테라 대역 WPAN시스템을 준비하는데 있어서 유용한 자료로서 사용될 수 있을 것이라 여겨진다.

MRI-based Algorithm for Acute Ischemic Stroke Subtype Classification

고영채,이수주,정종원,한문구,박종무,강규식,박태환,박상순,조용진,홍근식,이경복,이준,김동억,김대현,차재관,김준태,최재철,신동익,이지성,이준영,유경호,이병철,배희준 대한뇌졸중학회 2014 Journal of stroke Vol.16 No.3

Background and Purpose In order to improve inter-rater reliability and minimize diagnosis of undetermined etiology for stroke subtype classification, using a stroke registry, we developed and implemented a magnetic resonance imaging (MRI)-based algorithm for acute ischemic stroke subtype classification (MAGIC). Methods We enrolled patients who experienced an acute ischemic stroke, were hospitalized in the 14 participating centers within 7 days of onset, and had relevant lesions on MR-diffusion weighted imaging (DWI). MAGIC was designed to reflect recent advances in stroke imaging and thrombolytic therapy. The inter-rater reliability was compared with and without MAGIC to classify the Trial of Org 10172 in Acute Stroke Treatment (TOAST) of each stroke patient. MAGIC was then applied to all stroke patients hospitalized since July 2011, and information about stroke subtypes, other clinical characteristics, and stroke recurrence was collected via a web-based registry database. Results The overall intra-class correlation coefficient (ICC) value was 0.43 (95% CI, 0.31-0.57) for MAGIC and 0.28 (95% CI, 0.18-0.42) for TOAST. Large artery atherosclerosis (LAA) was the most common cause of acute ischemic stroke (38.3%), followed by cardioembolism (CE, 22.8%), undetermined cause (UD, 22.2%), and small-vessel occlusion (SVO, 14.6%). One-year stroke recurrence rates were the highest for two or more UDs (11.80%), followed by LAA (7.30%), CE (5.60%), and SVO (2.50%). Conclusions Despite several limitations, this study shows that the MAGIC system is feasible and may be helpful to classify stroke subtype in the clinic.

급성 뇌경색 환자에서 뇌졸중치료실과 일반병동 치료 후 사망률과 의존성의 차이

고영채,한문구,김욱주,오창완,백남종,배희준,권오기,정철규 대한신경과학회 2009 대한신경과학회지 Vol.27 No.2

Background: There is strong evidence for the efficacy of stroke unit (SU) care, which has become a common practice in other developed countries but is available only in a small number of centers in Korea. This late introduction of SU care in Korea can be at least partly attributed to doubts about its benefits on patient outcomes compared to general ward (GW) care in our routine practice. Methods: Based on a prospective stroke registry, we identified 1,300 acute stroke patients hospitalized in either SUs (n=195) or GWs (n=1,105) from January 2004 to June 2008. Clinical outcomes such as fatality and disability rates were compared using propensity score matching in the total cohort. Additional statistical adjustments were performed using stepwise logistic regression analyses with the backward elimination method for potential confounders. Results: The baseline characteristics did not differ significantly between patients admitted to SUs (n=195) and their matched controls (n=386). The 3-month dependency rate was 17.4% in SUs and 21.0% in GWs (p=0.31), and the case fatality rates were 1.5% and 8.0% (p<0.001), respectively. Adjusted odds ratios for SU care were 0.49 for dependency (95% confidence interval [CI]=0.22-1.08) and 0.17 for death (95% CI=0.04-0.83). Conclusions: This study showed that SU care reduces fatality rates and improves functional outcomes, which indicates the need to implement more SUs in Korea. Background: There is strong evidence for the efficacy of stroke unit (SU) care, which has become a common practice in other developed countries but is available only in a small number of centers in Korea. This late introduction of SU care in Korea can be at least partly attributed to doubts about its benefits on patient outcomes compared to general ward (GW) care in our routine practice. Methods: Based on a prospective stroke registry, we identified 1,300 acute stroke patients hospitalized in either SUs (n=195) or GWs (n=1,105) from January 2004 to June 2008. Clinical outcomes such as fatality and disability rates were compared using propensity score matching in the total cohort. Additional statistical adjustments were performed using stepwise logistic regression analyses with the backward elimination method for potential confounders. Results: The baseline characteristics did not differ significantly between patients admitted to SUs (n=195) and their matched controls (n=386). The 3-month dependency rate was 17.4% in SUs and 21.0% in GWs (p=0.31), and the case fatality rates were 1.5% and 8.0% (p<0.001), respectively. Adjusted odds ratios for SU care were 0.49 for dependency (95% confidence interval [CI]=0.22-1.08) and 0.17 for death (95% CI=0.04-0.83). Conclusions: This study showed that SU care reduces fatality rates and improves functional outcomes, which indicates the need to implement more SUs in Korea.

수근관 증후군 환자의 수술 후 증상 호전과 전기생리학적 호전시기의 관련성에 관한 예비연구

고영채,이영배,김윤봉,유찬종,신원철,박현미,하경식,신동진 대한임상신경생리학회 2003 Annals of Clinical Neurophysiology Vol.5 No.2

Background and Objectives: A nerve conduction study (NCS) has been known as a useful method to evaluate the therapeutic effect of operation in carpal tunnel syndrome (CTS). To evaluate the temporal relationship between symptomatic and electrophysiological improvement, we compared the preoperative symptoms and electrophysiological results with postoperative those. Methods: We analyzed the NCS changes before and after minimal release of carpal tunnel in 26 patients (34 hands) with CTS. The time of postoperative symptomatic changes, postoperative electrophysiological changes and temporal relationship between symptomatic and electrophysiological changes were evaluated. Results: The mean age was 49±13 years. The proportion of males to female was 8 and 92 percent. The median interval days between date of operation and those of postoperative NCS was 28.5 days. Postoperative symptoms improved in 17 hands, slightly improved in 13 hands, and have not changed in 4 hands. Electrophysiological improvements after operation were observed in 26 hands, and mostly appeared within 2 months. Symptomatic relief accompanied with electrophysiological improvement reported in 13 hands (50%). Moreover, the four hands with symptom, not relieved by decompression, showed electrophysiological improvement. Conclusions: In this study, electrophysiological improvement was in consistency with symptomatic relief to some extent, but we got the result of disagreement between electrophysiological and symptomatic improvement.

일개 병원기반 코호트에서 관찰한 장기간의 뇌졸중 재발률

고영채,김욱주,양미화,오창완,백남종,한문구,배희준,박정현,정철규,권오기 대한신경과학회 2009 대한신경과학회지 Vol.27 No.2

Background: Recurrent stroke is a major cause of morbidity and mortality among stroke survivors. However, studies of the long-term prognosis after acute stroke are very rare, especially in Asia. This study aimed to provide estimates of recurrent stroke rates by age, gender, and subtype of stroke in an unselected cohort of patients hospitalized to a community-based general hospital due to acute stroke. Methods: Based on a prospective stroke registry, acute stroke patients were enrolled within 7 days of symptom onset and followed retrospectively or prospectively for up to 3 years. Information was gathered about stroke recurrence and other vascular events. The cumulative risk of recurrent stroke was calculated using the Kaplan-Meier method. Results: Two-thousand and sixty-eight patients were enrolled in this study. The cumulative risks of stroke recurrence were 2.3%, 5.5%, 8.6%, and 10.0% at 90 days and 1, 2, and 3 years, respectively. The prevalence of stroke recurrence increased with age and the presence of previous stroke history (p<0.001), but not with gender or stroke subtype. Conclusions: To the best of our knowledge, this is the first cohort study of stroke recurrence in Korea. Its limitation of being a single hospital-based study warrants community- or multicenter-based cohort studies to identify high-risk groups for stroke recurrence. Background: Recurrent stroke is a major cause of morbidity and mortality among stroke survivors. However, studies of the long-term prognosis after acute stroke are very rare, especially in Asia. This study aimed to provide estimates of recurrent stroke rates by age, gender, and subtype of stroke in an unselected cohort of patients hospitalized to a community-based general hospital due to acute stroke. Methods: Based on a prospective stroke registry, acute stroke patients were enrolled within 7 days of symptom onset and followed retrospectively or prospectively for up to 3 years. Information was gathered about stroke recurrence and other vascular events. The cumulative risk of recurrent stroke was calculated using the Kaplan-Meier method. Results: Two-thousand and sixty-eight patients were enrolled in this study. The cumulative risks of stroke recurrence were 2.3%, 5.5%, 8.6%, and 10.0% at 90 days and 1, 2, and 3 years, respectively. The prevalence of stroke recurrence increased with age and the presence of previous stroke history (p<0.001), but not with gender or stroke subtype. Conclusions: To the best of our knowledge, this is the first cohort study of stroke recurrence in Korea. Its limitation of being a single hospital-based study warrants community- or multicenter-based cohort studies to identify high-risk groups for stroke recurrence.

危機를 機會로 바꾸는 知慧

高英彩 법무부 국제법무과 1996 通商法律 Vol.- No.7

하시모토 갑상선염을 동반한 근위축성 측삭경화증 1예

고영채,강성수,이영배,박현미,신동진 대한임상신경생리학회 2001 Annals of Clinical Neurophysiology Vol.3 No.1

Although the etiology and pathogenesis of amyotrophic lateral sclerosis(ALS) in unknown, increasing evidence support a role autoimmune machanisms in motor neuron degeneration. The coexistence of immune disease in ALS supports that an altered immune system may contribute to disease pathogenesis. A 55-year-old woman was admitted to our department due to dysarthria and gait disturbance. On physical and neurologic examination, she showed thyroid enlargement, tongue atrophy, muscle weakness, fasciculation, and increased deep tendon reflex. The electrophysiological studies are compatible with motor neuron disease. Cytological findings of thyroid were compatible with hashimoto's thyroiditis. Thus, we report a case of ALS combined with Hashimoto's thyroiditis. And the simultaneous presentation with ALS and Hashimoto's thyroiditis led us to consider whether this was simply a chance association or not.

비면역성 태아수종 2 예

고영채(YC Koh),안석환(SH Ahn),김용봉(YB Kim),박성관(SK Park) 대한산부인과학회 1988 Obstetrics & Gynecology Science Vol.31 No.10

자궁외임신의 치료에 있어서 복강경 수술과 개복술의 비교

고영채 ( Young Chae Ko ),이희 ( Hee Lee ),최원일 ( Won Il Choi ),최성은 ( Sung Eun Choi ),이영일 ( Young Il Lee ),조태일 ( Tae Il Cho ) 대한산부인과학회 2005 Obstetrics & Gynecology Science Vol.48 No.1

개회충증: 뇌경색의 드문 원인

김윤봉,고영채,전성호,박현미,신원철,이영배,하경식,신동진,임영희,류재숙,정명숙 대한신경과학회 2003 대한신경과학회지 Vol.21 No.6