• ETRI Journal
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• v.9 no.1
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• pp.12-18
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• 1987

IBM PC에 graphics 기술을 도입하여 개인용 전자 자동설계 시스팀인 EDAS_P를 개발하였다. EDAS_P는 전자회로도의 입력으로부터 연결상태 추출, 모의시험 및 검증에 이르는 일련의 과정이 자동화된 시스팀이다. 본고에서는 EDAS_P를 이루는 각 tool의 기능 및 전체적구성을 소개 하였다.

• ETRI Journal
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• v.38 no.4
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• pp.606-611
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• 2016

This paper presents antenna selection schemes for recently proposed quadrature spatial modulation (QSM) systems. The antenna selection strategy is based on Euclidean distance optimized antenna selection (EDAS). The symbol error rate (SER) performance of these schemes is compared with that of the corresponding algorithm associated with spatial modulation (SM) systems. It is shown through simulations that QSM systems using EDAS offer significant improvement in terms of SER performance over SM systems with EDAS. Their SER performance gains are seen to be about 2 dB-4 dB in $E_s/N_0$ values.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.541-544
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• 1988

EDAS_P system for electronic circuits design, which is developed at ETRI. There are 3 kinds of graphics tools. In this paper, we presents the improved graphics functions of EDAS_P system using the GSS${\times}$CGI.

• ETRI Journal
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• v.9 no.1
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• pp.19-24
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• 1987

EDAS_P 시스팀은 사용자와 컴퓨터간에 정보의 교환이 빈번히 일어난다. 그러므로 CAE시스팀은 사용자가 쉽고 자연스럽게 작업할 수 있도록 설계하여야 한다. 본고에서는 interactive graphic 시스팀에 man-machine interface문제를 기능별로 분류하면서, 전자회로 설계용 CAE 시스팀인 EDAS_P에서 응용한 기술을 예로 설명 한다.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.22-30
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• 1994

Encephalo-duro-arterio-synangiosis (EDAS) is a relatively new surgical procedure for treatment of childhood moyamoya disease. We assessed regional cerebral perfusion in moyamoya patients before (1.3 mo) and after (6.8 mo) EDAS with $^{99m}Tc$-HMPAO brain SPECT. A total of 21 EDAS operations in 17 moyamoya patients was included. Preoperative CT or MRI showed cerebral infarction in 14 patients and carotid angiography showed Suzuki grade I to V stenosis in 6%, 9%, 62%, 12% and 12% of the hemispheres respectively. Preoperative SPECT showed regional hypoperfusion in all patients, bilateral frontal and temporal lobes being the most frequently involved site. $4{\times}4$ pixel sized ROIs were applied on the frontotemporal cortex in 3 slice averaged transverse tomographic images. An index of regional perfusion was measured as: PI (%)=average F-T activity/average cerebellar activity${\times}100$ Pre-EDAS ipsilateral PI ranged from 23.7 to 98.4% (mean: $74.3{\pm}17%$) and increased significantly after operation ($81.4{\pm}17%$, p<0.001). Individual post-EDAS PI improved in 15/21 cases, showed no significant change in 5 and was slightly aggravated in 1. The amount of clinical improvement (${\Delta}CI$) was graded with a scale of 0 to 4 based on frequency and severity of TIA attacks. When patients were grouped according to pre-EDAS PI, group II (PI 70-89) showed a significantly higher ${\Delta}CI$ (3.3) compared to group I (PI< 70, 1.57) or group III (PI >90, 0.5) (P< 0.001). The amount of perfusion improvement (${\Delta}PI$) showed significant correlation with ${\Delta}CI$ (r=0.42, p=0.04). ${\Delta}PI$ did not, however, correlate with the amount of neovascularization assessed angiographically in 8 patients. Serial HMPAO SPECT is an useful noninvasive study for assessing perfusion improvement after EDAS in childhood moyamoya patients.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.72-80
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• 2017

In this work, an efficient transmit antenna selection approach for the quadrature spatial modulation (QSM) systems is proposed. The conventional Euclidean distance antenna selection (EDAS)-based schemes in QSM have too high computational complexity for practical use. The proposed antenna selection algorithm is based on approximation of the EDAS decision metric employed for QSM. The elimination of imaginary parts in the decision metric enables decoupling of the approximated decision metric, which enormously reduces the complexity. The proposed method is also evaluated via simulations in terms of symbol error rate (SER) performance and compared with the conventional EDAS methods in QSM systems.

• Journal of Korean Neurosurgical Society
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• v.38 no.6
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• pp.413-418
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• 2005

Objective : Although an encephaloduroarteriosynangiosis procedure using the superficial temporal artery [STA-EDAS] is an effective indirect bypass method in children with moyamoya disease[MMD], there is still a need for an additional bypass operation that can cover the area of the posterior circulation. The goal of this study is to evaluate the efficacy of the EDAS procedure using the occipital arteries [OA-EDAS]. Methods : From August 2003 to April 2004, We performed OA-EDAS in sixteen patients with MMD who have a circulatory insufficiency in the territory of the posterior cerebral artery[PCA]. The medical records were reviewed retrospectively. The surgical outcomes, including the changes in neurological status and imaging studies, with the degree of neovascularization on the cerebral angiogram, and the hemodynamic changes on single-photon emission computed tomography[SPECT], were analyzed. Results : These 16 children consisted of 5 boys and 11 girls aged 2 to 9 years. The clinical outcome of their PCA symptoms, such as visual transient ischemic attacks[TIAs] or visual field defect, was favorable in 14 patients of 16. Nine patients of 11 who underwent follow up magnetic resonance imaging[MRI] showed favorable MRI changes. On angiogram most of the patients exhibited good or fair revascularization of the PCA territory [7 of 8]. The hemodynamic changes on SPECT in the PCA territory after surgery showed improved vascular reserve in 13 of the 16 territories. Conclusion : OA-EDAS is a safe and efficacious revascularization procedure in patients with MMD who have compromised cerebral perfusion in PCA territory, or with visual TIAs.

• ETRI Journal
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• v.9 no.1
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• pp.31-36
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• 1987

전자회로를 시뮬레이션하려면 게이트나 트랜지스터의 연결상태(netlist)를 입력시켜야 한다. EDAS_P시스팀의 SCHEX_P라는 tool은 그림으로 표현된 전자회로도로부터 연결상태를 추출하고, 계층 설계된 구조를 풀어 게이트나 트랜지스터만으로 표현된 netlist를 만든 후 시뮬레이터가 받아들일 수 있는 형식으로 문장을 재조립한다. 본고에서는 이 과정을 요약하여 설명 하고자 한다.

• ETRI Journal
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• v.9 no.1
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• pp.25-30
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• 1987

EDAS_P 시스팀을 이루고 있는 8개의 tool 중 symbol의 모양을 정의하는 SYMED_P, 전자회로도를 입력시키는 SCHED_P, 그리고 논리 검증결과를 그림으로 표현하는 WAVGR_P는 graphics 기술을 이용하여 정보를 취급한다. 본고에서는 그림으로 정보를 표현하는데 필요한 기술을 발췌식으로 선별하여 소개하였으며, 그림정보를 표현하는 형식 및 정보의 종류를 설명한다.

• ETRI Journal
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• v.9 no.1
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• pp.37-42
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• 1987

개인용 전자자동설계 시스팀인 EDAS_P의 schematic으로부터 직접 디지틀 회로의 논리동작을 시뮬레이션할 수 있는 게이트 레벨 논리 시뮬레이터(GLSIM_P)를 IBM PC에서 C언어를 이용하여 개발하였다. 다룰수 있는 소자로는 input clock, 일반 게이트 및 clocked 게이트, ROM, RAM, PLA등이다. 논리신호 레벨은 1, 0,*(intermediate)이다. 효율적인 논리해석을 위해 selective trace 및 event driven 방식을 도입하였으며 게이트 500개 정도까지 해석이 가능하다.