DDI에 사용가능한 높은 슬루율의 전류 부스팅 회로를 갖는 CMOS 증폭기 설계에 관한 연구

김성호,김요섭,손상희 청주대학교 산업과학연구소 2017 産業科學硏究 Vol.35 No.1

In this paper, we designed an AB-class rail-to-rail differential OP-AMP with the desired slew rate and low power consumption while maintaining minimum specifications of other parameters. To realize the above mentioned it, we propose a new concept that uses a current boosting circuit at the bias stage and a voltage comparator circuit at the output stage that can increase the gate voltage. The amplifier with high slew rate and fast driving speed without increasing the power consumption is designed and tried to demonstrate its performance through computer simulation. Simulation results show that the proposed circuit has a high slew rate of 18.3 V/us while the conventional circuit has a low slew rate of 2 V/us.

HEMT素子의 I-V特性에 대한 解析的 모델링에 관한 硏究

張虎聲,洪淳錫,呂正鉉 홍익대학교 산업기술연구소 1994 産業技術 Vol.3 No.-

In this paper, we solve one-dimensional Poisson's equation the gate-bias dependence of 2DGE variation by charge control mechanisum including the depletion with of GaAs layer. In addition, we derive analytically schroedinger's equation by new qauntum well approximation in order to include the broadening effect of the quantum well in the cut off regime. Proposed, analytical model for Ⅰ-Ⅴ characteristics of a Al Ga As / GaAs HEAT device can be described well the depletion with and conduction band energy level of GaAs. The resulting Ⅰ-Ⅴ characteristics describe quite well the effect of GaAs doping concentration over a wide range of operation.

항응고제 치료와 연관된 자발성 근육내 혈종

김수성,조재훈,이학승,박현영,장혁,김요식,조광호 원광대학교 의과학연구소 2009 圓光醫科學 Vol.24 No.1

항응고제 치료의 주된 합병증은 출혈로서 주로 뇌실질과 복강 내에 발생하며 사지 근육에 발생하는 근육내 혈종은 매우 드문 것으로 알려져 있다. 이러한 항응고제 치료 후 발생하는 자발성 근육내 혈종은 발생빈도가 드물 뿐 아니라, 심부정맥혈전증과 그 증상이 유사하여 감별하기가 쉽지 않다. 저자들은 항응고제 치료 후 운동 마비가 발생한 사지 근육에서 자발성 근육내 혈종이 발생한 증례를 경험하여 이를 보고한다. Spontaneous intramuscular hematoma(SIH) is an uncommon but serious bleeding complication of anticoagulation therapy that has received little attention. We present a patient of spontaneous muscular hematoma during anticoagulation therapy for acute stroke management. A-74-year old man was admitted with sudden onset of dysarthria and left hemiparesis. Brain MRI and MRA showed acute cerebral infarction along right middle cerebral artery territory and severe stenosis of right proximal cervical internal carotid artery. During intravenous heparin treatment, he complained acute pain and swelling on left leg. Muscular CT showed enhancing focal soft tissue mass on left gastrocnemius muscle and ultrasonography demonstrated multiple hematomas on left gastrocnemius muscle. Treatment of heparin was stopped immediately. After conservative management for hematomas, symptoms were subsided.

齒根端肉芽腫과 齒根端襄腫의 電子顯微鏡的 硏究

林成森,呂寅浩 大韓齒科保存學會 1988 Restorative Dentistry & Endodontics Vol.13 No.2

The purpose of this study was to investigate the characteristic features of the cells and tissues of the chronic periapical lesions using light microscope and electron microscope. Fifteen dental periapical lesions were obtained from the patients undergoing periapical surgery. Each specimen was divided into two parts along the tooth axis. One part was routinely processed for histopathologic examinations. 12 periapical lesions were diagnosed as granuloma and 3 periapical specimens as periapical cyst. The other part was fixed in 2.5% glutaraldehyde in 0.1M sodium cacodylate buffer at pH 7.4 and 1% osmic acid in same buffer. They were embedded in Epon 812. The semithin sections were used for the orientation of the lesions and the ultrathin sections were stained conventionally and examined with AEI Corynth 500 electron microscope. The results were as follows. 1. PMN and macrophages, which were dominant cell type, were scattered in small or large numvers throughout the central destuctive area of granuloma. In the granulomatous area, plasma cells and lymphoytes sere found in significant number and a lot of new capillary formation were revealed. Clefts caused by cholesterol sere often seen in the connective tissue. Occasionally foam cell s became collected in groups and epithelial proliferation were present. 2. In both granuloma and cyst, some plasma cells contained narrow cisternae of granular endoplasmic reticulum of which was tightly packed with electron dense materials, and other cells exhibited dilated profiles of granular endoplasimic reticulum. 3. In the area where plasma cells and lymphocytes were collected in groups, lymphocytes with well developed nucleolus and profuse cytoplasm were found and differentiating plasma cells were also present. 4. In the epithelial strands of the granulomatous area, epithelial cells contained enlarged endoplasmic reticulum, tonofilaments and ribosoms. Toward the intercellular space epithelial cells protruded a few microvilli. In the intercellular space, exudate-like electron dense materials, most of which was attached to the plasma membrane, appeared. 5. Some foam cells filled with numerous lipid droplets and others had lipid droplets and crystal-like structures. 6. Cyst epithelium consisted of bright cells and dark cells. The former had bright cytoplasm and small amounts of ribosoms, and the latter dark cytoplasm, many ribosoms, mitochondria and elongated microvilli. 7. Epithelial cells near the cyst lumen protruded a lot of long microvilli toward intercelluar space and cyst lumen.

Thermafil 충전법의 근관폐쇄성에 관한 연구

임성삼,여인호,박찬제 大韓齒科保存學會 1996 Restorative Dentistry & Endodontics Vol.21 No.2

벤젠연소반응에서 팔라듐이 담지된 촉매 지지체의 세공크기 영향

서 곤,김종호,정상귀,송요순 전남대학교 촉매연구소 2000 촉매학술발표회 Vol.- No.17

VOC를 저온에서 연소시켜 제거하는 촉매는 활성이 우수하도록 귀금속을 다공성 지지체에 담지시켜 제조하다. 지지체의 세공이 크면 물질전달의 제한이 적으나 표면이 작다. 반면, 가는 세공이 많이 발달되면 표면적은 크지만 반응물의 물질전달 제한으로 연소반응이 느려질 수 있다. 따라서 저온에서 VOC를 연소시켜 제거하는 촉매의 지지체는 귀금속을 넓게 분산시킬 수 있도록 표면적이 넓으면서도 물질전달 저항이 적도록 세공이 커야 한다. 제올라이트 Y와 MCM-41 메조포러스 물질에 팔라듐을 달지한 촉매에서 벤젠 연소반응을 조사하였다 세공이 큰 메조포러스 물질에 담지된 팔라듐 촉매에서는250'E에서 벤젠 연소가 시작되며 300 "I에서는 전환율이 94%로 저온 연소활성이 놀다 반면 제올라이트 Y에 담지된 팔라듐 촉매에서는 350'E에서야 벤젠 연소가 시자되어 450'E에서도 전환율이 3j%로 낮다 세공이 작은 제올라이트 담지 팔라듐 촉매에서는 확산 제한으로 인해 연소반응이 느리게 진행되며,온도가논아져도 전환율 증가가 완만하다. 이에 비해, 세공이 큰 메조포러스 물질에 담지된 랄라퓸 촉매에서는 확산 제한이 적고 표면반응이 속도 결정단계이어서 낮은 온도에서도 연소반응이 빠르고, 온도가 높아지면 전환율이 급하게 증가되었다. 벤젠 연소반응에서 반응물과 세공의 크기 효과를 누센인자 등 정량화된 인자로 나타내어, 연소딴응에서 확산 효과를 검토하였다 이와 함께 지지체의 물성과세공구조가 연소촉매의 활성저하와 안정성에 미치는 영향도 고찰하였다.

벤젠연소반응에서 팔라듐이 담지된 촉매 지지체의 세공크기 영향

서곤,김종호,정상귀,송요순 전남대학교 촉매연구소 2001 觸媒硏究 論文集 Vol.22 No.-

VOC를 저온에서 연소시켜 제거하는 촉매는 활성이 우수하도록 귀금속을 다공성 지지체에 담지시켜 제조한다. 지지체의 세공이 크면 물질전달의 제한이 적으나 표면적이 작다. 반면, 가는 세공이 많이 발달되면 표면적은 크지만 반응물의 물질전달제한으로 연소반응이 느려질 수 있다. 따라서 저온에서 VOC를 연소시키면서도 물질전달 저항이 적도록 세공이 커야한다.

축구 오버헤드 킥 동작의 운동학적 분석

김의환,이요열,김성섭,권문석,김성호 한국운동역학회 2003 한국운동역학회지 Vol.13 No.1

Kim, E-H · Lee , Y-Y · Kim, S-S· Kwon, M-S · Kim, S-H. The kinematical Analysis of the Overhead Kick on Soccer. Korean Journal of Sport Biomechanics. Vol. 13, No. 1,pp. 155-171. The purpose of this study was to analyze the kinematic variables of over head Kick(OHK) in soccer with three dimensional analysis technique and show the kinematic characteristics of it. The 7 subjects were university football player who have been playing football more than 7 years. The OHK was filmed on 16mm video camera(30frame/sec.) kinematic variables were temporal, postures, and COG(center of gravity). The mean values and the standard deviation for each variables were obtained and used as basic factors for examining characteristics of OHK. the results of this analysis were as follows : Temporal variables : The total time elapsed(TE) of OHK was0.94~1.14sec., the 1st phase was 0.35sec., 2nd phase was 0.46sec., and 3rd phase was 0.22sec.. Posture variables : When subjects performed OHK at the impact event, the ankle and knee angle of kicking foot were more extend than supporting foot. but the hip angle of supporting foot were more extend than kicking foot. Moving distance of the center of mass of the both foot : When subject performed OHK at the impact event, the range of distance on mediolateral direction aspect into right · left shoulder line, anteroposterior direction aspect was 20.9±10.5cm, vertical direction aspect was 92.3±19.9cm. Angular velocity : the faster angular velocity of knee · ankle on the kicking foot grew form jump position to landing position, the faster velocity of ball became. C. O. G. variables : When subject performed OHK at the impact event, upper part of the body was getting lower, lower part of the body was getting higher.

일과성 전 기억상실증으로 나타난 크로이츠펠트 : 야콥병 1례

신대수,이승희,이한샘,박성욱,박현영,장혁,장성조,김요식,조광호 圓光大學校 醫科學硏究所 2004 圓光醫科學 Vol.19 No.1

Evolution of Video Coding Standards

Yo-Sung Ho 대한전자공학회 2006 ICEIC:International Conference on Electronics, Inf Vol.2006 No.6