• 한국결정성장학회지
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• 제11권1호
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• pp.20-26
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• 2001

Ti와 B을 각각의 증발원으로 한 2원 전자빔 증착법으로 500$^{\circ}$의 기판온도에서 (100) Si 기판 위에 티타늄 붕화물 (${TiB}_{x}$) 박막을 증착시켰다. 이 방법은 여러 가지 boron-to-totanium ratio ($0{\le}B/Ti \le 2.5$)를 가지는 비당량 (${TiB}_{x}$ 박막의 표면 조도 역시 B/Ti비에 의존하여 변화되었다. 그리고 Pure Ti 박막은 (002)면의 우선 성장거동을 나타내었으나, $B/Ti{\ge}1.0$의 경우 (111)면의 우선 성장거동을 보이는 단일상의 TiB 박막이 성장되었다. 그러나 B농도가 더욱 증가됨에 따라 육방정계의 ${TiB}_{2}$상이 형성되기 시작하여 $B/Ti{\ge}2.0$ 의 조성비를 가지는 박막에서는 단일상의 ${TiB}_{2}$ 화합물을 나타내었다. 그리고 Si 기판상에 증착된 ${TiB}_{x}$ 박막의 잔류응력은 B/Ti비에 의존하나, 2원 전자빔 증착법으로 성장된 모든 박막에서 3~$20{\times}^9$dyn/$\textrm{cm}^2$ 정도의 인장응력을 나타내었다.

• 한국결정성장학회지
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• 제22권3호
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• pp.122-126
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• 2012

$Al_2O_3$ 2 wt%가 도핑 된 ZnO(AZO) 타겟으로RF 스퍼터링 장비를 사용하여 $H_2/(Ar+H_2)$ 가스 비율에 따른 AZO 박막을 증착 후, 이들 박막의 특성을 조사하였다. AZO 박막은 $200^{\circ}C$, $2{\times}10^{-2}$ 공정조건에서 $H_2/(Ar+H_2)$ 가스 비율을 변화시키면서 증착하였다. AZO박막증착 중 수소가스의 첨가는 박막의 특성에 영향을 미쳤다. $H_2/(Ar+H_2)$ 가스 비율이 2.5 %일 때 비 저항(${\sim}9.21{\times}10^{-4}\;{\Omega}cm$)과 전자 이동도(${\sim}17.8\;cm^2/Vs$)는 각각 최소값과 최대값을 나타내었다. $H_2/(Ar+H_2)$ 가스 비율이 2.5 % 이상일 때는 $H_2/(Ar+H_2)$ 가스 비율이 증가할수록 비저항은 점차로 증가하였고 전자 이동도는 점차적으로 감소하였다. 전자 운반자 농도는 $H_2/(Ar+H_2)$ 가스 비율이 증가함에 따라 0 %에서 7.5 %까지 점차로 증가하였다. $H_2/(Ar+H_2)$ 가스 비율에 따라 증착된 박막의 가시광선 파장 범위에서 평균 광 투과도는 90 % 이상이었고 성장방향은 [002]이었다.

• 센서학회지
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• 제6권4호
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• pp.316-327
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• 1997

높은 큐리온도를 가진 다결정 세라믹스 $Sr_{2}Nb_{2}O_{7}$ 및 $La_{2}Ti_{2}O_{7}$을 화학적공침법으로 제조하고 하소분말의 입도분포와 상구조 및 소결특성 등을 조사하였으며, 소결온도에 따른 입자배향도와 전기적 특성을 선행연구 고상반응법 및 용융염합성법과 비교하였다. 화학적공침법을 이용함으로써 고상반응법에 비해 $100{\sim}150^{\circ}C$ 낮은 하소온도에서 단일상을 얻을 수 있었고, 특히 $Sr_{2}Nb_{2}O_{7}$의 경우, $700^{\circ}C$에서 중간 생성물 $Sr_{5}Nb_{4}O_{15}$가 생성된 후 $800^{\circ}C$의 낮은 하소온도에서 단일상이 나타났으며 얻어진 하소분말도 미세하고 균일하였다. 화학적공침법에 의해 $1500^{\circ}C$에서 소결한 $Sr_{2}Nb_{2}O_{7}$ 세라믹스는 이론밀도의 97%에 달하는 우수한 소결성을 보였을 뿐만 아니라 (0k0) 방향의 입자배향도가 현저히 컸으며, 결과적으로 절단방향에 따른 유전특성의 이방성을 나타내어 a-cut 방향의 유전율은 단결정에 비해 손색이 없었다.

• 한국지반공학회논문집
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• 제23권10호
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• pp.97-107
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• 2007

대규모 암반비탈면은 소규모 암반비탈면과 달리 파괴블록의 크기를 사면전체로 가정했을 경우 비합리적인 안정성 평가가 이루어질 가능성이 매우 크다. 즉, 파괴블록의 크기에 따라서 안전율, 절리면 강도정수 등이 변하기 때문에 대규모 비탈면의 경우에는 공학적인 방법으로 파괴 가능 블록크기 평가가 필요하다. 따라서 본 연구에서는 연구대상 부지의 절리조사자료를 이용하여 절리의 방향성(joint orientation) 및 절리간격(joint spacing) 통계분석, 3차원 절리발생 강도(joint intensity)분석 등의 과정을 거쳐 3차원 절리계를 생성한 후, 이를 이용하여 파괴가능 블록(failure block) 크기를 분석하였다. 분석결과 파괴유발이 우려되는 블록은 33개가 관찰되었으며, 최소크기 1.4m, 최대크기 38.7m, 평균크기 15.2m로 나타났다. 또한, 3차원 절리계 생성과정에서 발생되는 절리자료를 활용하여 확률론적해석, 2, 3차원 불연속체해석 등에 직접적으로 활용할 수 있었다.

• Composites Research
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• 제20권3호
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• pp.8-16
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• 2007

자동차 충돌이나 전복사고에 있어서 부재들의 변형은 축방향 압축붕괴와 함께 굽힘붕괴가 혼합된 변형양상을 보여주고 있으며, 자동차에 사용되는 대부분의 박벽관 부재는 굽힘붕괴가 주된 붕괴형태로 나타나고 있다. 하지만 혼성 사각관의 굽힘붕괴에 대한 연구는 축방향 붕괴의 연구에 비해 많이 부족한 현실이다. 본 논문에서는 알루미늄-복합재료 혼성 사각관의 굽힘 붕괴 거동 및 에너지 흡수 특성을 실험적 방법으로 연구하여 경량화 구조부재로서의 적용가능성을 조사하였다. 접착필름 살입형 경화법으로 제작된 알루미늄-복합재료 혼성 사각관 보에 대해 복합 재료 층의 적층두께와 적층 각에 따른 굽힘 성능을 평가하였다. 본 혼성 사각관 보는 복합재료만으로 구성된 사각관 보에서 발생할 수 있는 불안정한 붕괴모드를 안정적인 붕괴로 전환시키면서, 단순 알루미늄 사각관에 비해 에너지 흡수 능력이 향상되었고, 특히 $[0^{\circ}/90^{\circ}]s$를 적층한 혼성 사각관의 경우 벽두께 1mm인 알루미늄 사각관 시험편과 비교하여 흡수에너지가 1.78배 증가하였고 단위무게당 흡수에너지는 1.29배로 증가함을 보였다.

• Archives of Reconstructive Microsurgery
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• 제11권1호
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• pp.11-18
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• 2002

Large soft tissue defects around the knee joint are known to significantly diminish joint function. Severe soft tissue defects on the anterior aspect of the knee joint especially bring on significant joint motion limitation. Although simple split skin grafts can cover the skin defect, the progressing scar contracture of the grafted skin causes joint stiffness. One of the best solutions of large soft tissue defects around the knee joint is covering the defect with a good quality skin flap. Separated flaps with one vascular pedicle are good candidates for covering anterior and posterior aspects of the joint for example. Authors performed 12 cases of combined scapular and latissimus dorsi free flaps from 1984 to 2000. Among them, we experienced 5 cases of knee joint defect covering using the double free flap for coverage of the soft tissue defect with preservation of the knee joint function and satisfactory results. The system of flaps based on the subscapular artery and vein provides a variety of composite free flaps. The possible flaps that can be harvested based on this single vascular pedicle include the scapular and parascapular skin flap, the serratus anterior and latissimus dorsi muscular flap, the lateral scapular bone flap, the latissimus dorsi-rib flap, and the serratus anterior-rib flap. This combined flap is available for multiple tissue defects or complex defects because it can be incorporated with skin, muscle and bone flaps. A main advantage is the independent vascular pedicles of each component, which allow freedom in orientation of each components. Consequently it can be freely applied to any form of three dimensional defects on the upper and lower extremities. The combination of scapular cutaneous flap and latissimus dorsi musculocutaneous flap can be resurfaced for massive cutaneous defects on the extremities. We report the use of the combined scapular and latissimus dorsi free flap in five patients to reconstruct massive defects on the extremities with resultant improved joint function. There was no flap failure and minimal complications and disadvantages. The anatomy of this flap is reviewed and the indication and advantages are discussed. All of the five flaps survived and there was no scar contracture affecting the joint motion.

• 시큐리티연구
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• 제1호
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• pp.283-319
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• 1997

Our society witnesses the rapid progress in the areas of politics, economy, society and culture in the process of national modernization since 1960s, which in turn as a reverse function gets to contract a societic pathology, totally lowering the security level of citizens' lives owing to various violent crimes like hostage commotions and murders with rifles and deadly weapons. what is the main reason for that? That may be partly because the chief police force concentrates on the current situation resulting in the vacuum of the public peace. However, the main reason is that the police fall short of man-power and equipments even if the whole police power were put to use in preventing and quelling the crimes. That is true not only of Korea but also of the advanced countries like the U.S.A., England and Japan. We realize that these advanced countries have higher level of security in every individual's life and property than Korea because their progress of the private guard systems can fill in a vacuum of the shortage of the police power, Therefore, we should without delay internationalize our private guard systems expecting the widely opening of the guard service markets in the age of Uruguay Round. To do this, we need to change our ideas for fostering the policy of the private guard from passive defense ideas into positive aggressive ones. Our police should urgently set up a plan to pursue the orientation of vision that we should dispatch our private guards overseas before foreign guards rush into our markets. Accordingly it goes without saying that the private guard group should distinguish their services from the public services initiating their own theory and strategy of private guard services and also readjust themselves between the public duties and the private services with the study of minimizing the reverse function of the private guard systems. The history criminal justice has always shown that the criminal system progressed at the initiative of the civil factor in case its demand and supply do not make both ends meet. Nevertheless, in the process the power of the government never weakens, rather it is built up in general. In conclusion, the necessity of the build-up of the private guard services must duly be acknowledged by the police as well as by the business which has its unique sphere within the criminal justice instead of as the suplemtary services of the simple the police power on the long-term basis. The purpose of the private guard services can be largely classified into the two categories; first it means the function to prevent the crimes against the citizens and secondly to enhance the national interest as an increasing mammoth business with a worldly competition capacity. The police has an absolute responsibility that they should protect the modem public in general from feeling the crisis of the personal threat, tension, anxiety and nervousness. In short, if we develop the complete private guard system to guarantee the societic atmosphere for all citizens, keep the public peace, and protect all citizens' lives and properties, we will sure enjoy a beautiful land, a wholesome society and a happy life in goodharmony of law and order.

• 대한임상검사과학회지
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• 제51권3호
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• pp.351-359
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• 2019

신경인지검사는 외래에서 전반적인 인지기능 정도를 평가하는 MMSE (Mini-Mental State Examination)가 가장 보편적이지만, 최근에는 SNSB II (Seoul Neuropsychological Screening Battery II)를 통해 심층적으로 진단에 활용된다. 2017년부터 2018년까지 경기도 남부지역 일개 의료원에 내원한 보건소에서 정밀검사 의뢰된 노인층 120명의 통상적인 신경인지검사 결과와 혈액검사 항목을 후향적으로 조사하였다. GDS의 하위 영역의 평가에서는 시공간 능력이 높게 나타났다. 그리고 혈액 전해질 중 Na이 GDS 수준이 증가함에 따라 통계적으로 유의한 감소를 보였다. 또한 GDS 수준에 따른 집중력, 언어 시공간능력, 기억력, 전두엽 실행 기능이 통계적으로 유의한 감소를 보였다(P<0.001). ALT와 크레아티닌이 정상군과 비정상군에서 전두엽 실행 기능 영역이 통계적으로 유의한 차이를 보였다(P<0.001). 또한 GDS와 ALT는 음의 상관성을 보였다(P<0.01). 결론적으로 본 연구를 통해 선별 및 진단에 유의한 검사 항목을 개발하는데 기초정보를 제공하고, 통상적인 혈액화학검사가 인지장애 환자의 진단 및 진행에 대한 기본 정보를 제공할 것으로 사료된다.

• 정신신체의학
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• 제4권2호
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• pp.170-181
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• 1996

Objective : This study was tried to investigate the specific relationships among cognitve function, neurbehavioral symptoms, and daily living functions, as well as provide the guidline of more proper clinical approches for patients with subcortical cerebrovascular disease. Objects and Methods Subjects were 85 patients whose diagnosis was confirmed by brain CT or MRI and controls were 195 normal persons matched by educational level with the subjects. The cognitive functions were evaluated by BNA(Benton neuropsychiatric assessment), subjective neurobehavioral symptoms by SCL-90-R(Sympton Check List-90-Revised), objective neurobehavioral symptoms by NRS(Neurobehavioral Rating Scale), and daily living function symptoms by NRS(Neurobehavioral Rating Scale), and daily living function by GERRI(Geriatric Evaluation by Relative's Rating Instrument) and IADL(Instrumental Activities of Daily Living Scale). Results: 1) Subjects showed significantly lower cognitive functions than controls in all tests of BNA except Lt-Rt Orientation Test(p=0.09) and facial Recognition Test(p=0.186). 2) In subjective neurobehavioral symptoms, subjects showed significantly lower scores in all symptoms except anxiety(p=0.059), hostility(p=0.159), and phobic anxiety(p=0.849). But in objects neurobehavioral symptoms, subjects showed significantly higher in scores in psychoticism (p=0.000) and neuroticism(p=0.025) of NRS. 3) The score of social functioning of GERRI(p=0.000) and that of IADL(p=0.000) were significantly higher in subjects than in controls. 4) for correlation between cognitive and daily living functions, there were significant correlations between the scores of all items on BNA and the score of cognitive or social function of GERRI and the socre of MDL in corntrols, whereas in subjects, there were significant correlations only between the scores of BNA and the score of IADL. 5) for correlation between neuroehavioral symptoms and daily living functions, there were significant correlatons between the socre of subjective neurobehavioral symptoms and the scores of all subscales of GERRI and the score of MDL in controls. On the contrary, in subjects, there were significant correlations between the score of social function of GERRI and the score of objective neurobehavioral symptoms such as psychoticism, agitiation-hostility, and decrease d motivation-emotional withdrawl. Conclusion : Above results suggest that disturbances in specific function of brain may play a role as a predictor of impairments with specific daily living functions and also suggest that specific correlations among various functions may be useful as clinical parameters for setting of the treatment goal and for assessing the ongoing process in the treatment and rehavilitation of the patients with subcortical cerebrovascular disease.

• 제어로봇시스템학회논문지
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• 제20권2호
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• pp.200-210
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• 2014

An active virtual impedance algorithm is newly proposed to track a sound source and to avoid obstacles while a mobile robot is following the sound source. The tracking velocity of a mobile robot to the sound source is determined by virtual repulsive and attraction forces to avoid obstacles and to follow the sound source, respectively. Active virtual impedance is defined as a function of distances and relative velocities to the sound source and obstacles from the mobile robot, which is used to generate the tracking velocity of the mobile robot. Conventional virtual impedance methods have fixed coefficients for the relative distances and velocities. However, in this research the coefficients are dynamically adjusted to elaborate the obstacle avoidance performance in multiple obstacle environments. The relative distances and velocities are obtained using a microphone array consisting of three microphones in a row. The geometrical relationships of the microphones are utilized to estimate the relative position and orientation of the sound source against the mobile robot which carries the microphone array. Effectiveness of the proposed algorithm has been demonstrated by real experiments.