Microwave Dielectric Properties of (${Pb_{0.2}}{Ca_{0.8}}$)[$({Ca_{1/3}}{Nb_{2/3}})_{1-x}{Ti_x}$$O_3$ 세라믹스의 마이크로파 유전특성

김응수,김용현,김준철,방규석,Kim, Eung-Soo,Kim, Yong-Hyun,Kim, Jun-Chul,Bang, Kyu-Seok 한국재료학회 2001 한국재료학회지 Vol.11 No.8

($Pb_{0.2}$$Ca_{0.8}$ )[($Ca_{1}$3$Nb_{2}$3/)$_{1-x}$ $Ti_{x}$ ]O$_{3}$ 세라믹스의 $^{4+}$ 치환량 변화에 따른 마이크로파 유전특성을 고찰하였다. $Ti^{4+}$ 치환량이 증가함에 따라 x=0.05부터 x=0.15까지의 조성범위에서는 단일상의 페롭스카이트상을 얻을 수 있었으며, x=0.2이상에서는 $Ti_2$와 $CaNb_2$$O_{6}$ 가 제 2상으로 존재하였고, 결정구조는 x=0.05에서 사방정(orthorhombic) 구조가 x=0.35에서 이방정(cubic) 구조로 전이하였다. 유전상수(K)는 $Ti^{4+}$ 치환량의 증가에 따라 rattling 효과의 증가로 인하여 증가되었으며, B-자리 양이온의 평균이온반겨의 세제곱의 반비례하였다. 그러나 결정립 크기의 감소와 제 2상의 존재로 인하여 Qf값은 감소하였다. $Ti^{4+}$ 치환량이 증가됨에 따리 tolerance factor(t)와 B-자리 결합원자가의 영향으로 공진주파수의 온도계수(TCF)는 -27.36ppm/$^{\circ}C$값으로부터 +18ppm/$^{\circ}C$r값으로 조절되었다. $1350^{\circ}C$d서 3시간 소결한 ($Pb_{0.2}$ $Ca_{0.8}$ )[(Ca$_{1}$3$Nb_{2}$3)$_{1-x}$ /$Ti_{x}$]$O_{3}$ 시편에서 K=51.67, Qf=7268(GHz), TCF=0 ppm/$^{\circ}C$의 우수한 특성을 얻을 수 있었다. Microwave dielectric properties of $(Pb_{0.2}Ca_{0.8})[(Ca_{1/3}Nb{2/3})_{1-x}Ti_x]O_3$ ceramics were investigated as a function of $Ti^{4+}$ content (0.05$\leq$x$\leq$0.35). A single perovskite phase was obtained from x=0.05 to x=0.15, and $TiO_2$ and $CaNb_2O^6$ were detected as a secondary phase beyond x=0.2. The structure was changed from orthorhombic at x=0.05 to cubic at x=0.35. Dielectric constant(K) was increased with increase of $Ti^{4+}$ content due to increase of rattling effect, and was inversely proportional to the cube of the average radius of B-site cation, however, Qf value was decreased, which was due to the decrease of grain size and the secondary phase. With the increase of $Ti^{4+}$ content, the temperature coefficient of resonant frequency(TCF) was controlled from -27.36 ppm/$^{\circ}C$ value to +18.4 ppm/$^{\circ}C$ value, which was caused by the influence of tolerance factor(t) and the bond valence of B-site. Typically, K of 51.67, Qf of 7268(GHz), TCF of 0 ppm/$^{\circ}C$ were obtained in the $(Pb_{0.2}Ca_{0.8})[(Ca_{1/3}Nb_{2/3})_{0.8}Ti_0.2]O_3$ sintered at 13$50^{\circ}C$ for 3h.

졸-겔 공정에 의한 YMnO₃ 박막의 전기적 특성

김응수,김병규,김유택,Kim, Eung-Soo,Kim, Beng-Gu,Kim, Yoo-Taek 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.5

$Y(NO_3)_3{\cdot}5H_2O$ 과 $Mn(CH_3CO_2)_2{\cdot}4H_2O$를 출발물질로 하여 졸-겔(sol-gel)법으로 Si(100) 기판위에 육방정계의 $YMnO_3$ 박막을 제조하였다. $YMnO_3$ 박막의 열처리 온도변화, 가수분해시 가수의 양(Rw)과 촉매제의 첨가에 따른 결정 구조 및 전기적 특성을 조사하였다. $YMnO_3$ 박막의 결정화는 700${\circ}C$부터 시작되었고 완전한 결정화는 800${\circ}C$-1시간 열처리하여 이루어 졌으며, $YMnO_3$ 박막의 가수의 양 Rw=6일때 육방정계 $YMnO_3$상의 c-축 (0001) 우선 배향성을 나타내었고, Rw=1 과 Rw=12인 경우에는 Rw=6인 경우보다 c-축 배향성은 감소하였다. 산성이나 염기성 촉매제 첨가에 따라 $YMnO_3$ 박막의 결정성 및 우선 배향성은 영향을 받아 c-축 우선 배향성은 감소하고 사방정계의 $YMnO_3$ 상을 형성하였다. Rw=6일 때 $YMnO_3$박막은 0.2V인가 전압에서 $1.2{\times}10-8 A/cm^2$으로 우수한 누설 전류 밀도를 나타내었고 누설 전류 밀도는 인가 전압에 따라 크게 변하지 않았다. Hexagonal $YMnO_3$ thin films were prepared from $Y(NO_3)_3{\cdot}5H_2O$ and $Mn(CH_3CO_2)_2{\cdot}4H_2O$ as starting materials on the Si(100) substrates by the sol-gel method. The crystal structure and the electrical properties of the $YMnO_3$ thin films were investigated as a function of heat treatment temperature, the amount of water(Rw) of hydrolysis and the addition of catalysis. The crystallization of the $YMnO_3$ thin film began at 700${\circ}C$ and completed at 800${\circ}C$ for 1 h. The c-axis (0001) preferred orientation of hexagonal $YMnO_3$ was detected for the $YMnO_3$ thin films with Rw=6 and that was decreased for the $YMnO_3$ thin films with Rw=1 and Rw=12. The crystallinity and preferred orientation of the $YMnO_3$ thin films were depended on the addition of acid and/or alkali catalysis, which, in turn, the preferred orientation of c-axis was decreased and the orthorhombic phase of $YMnO_3$ was detected to the specimens with the addition of catalysis. The $YMnO_3$ thin film with Rw=6 showed good leakage current density of $1.2{\times}10-8 A/cm^2$ at the applied voltage of 0.2V and the leakage current density was not changed drastically with applied voltage.

가시광통신을 이용한 로봇 위치확인 시스템

김응수,Kim, Eung Soo 한국마이크로전자및패키징학회 2016 마이크로전자 및 패키징학회지 Vol.23 No.4

본 논문에서는 이동 로봇의 위치 추정을 위해 LED를 이용한 가시광 통신에 의해 로봇의 위치를 확인하고 광센서를 이용하여 로봇의 이동 경로를 추정하는 시스템을 제작 하였다. 제작된 위치확인 시스템은 외부 빛인 태양광과 형광등의 영향은 없었으며, 실험에 사용된 4개의 LED는 다른 신호를 전송하므로 로봇의 위치를 확인할 수 있었고, 광센서를 사용하여 로봇의 이동경로를 실시간으로 추적 할 수 있음을 실험을 통하여 확인하였다. In this paper, we have fabricated the position detection system with LED and optical sensor to detect a position and trace of robot through visible light communication (VLC). The fabricated position detection system did not have been affected by sunlight in outdoor and a fluorescent light in building. Because 4 LEDs, respectively, transmitted different signals, we have known the position of robot. And we have also observed a trajectory of robot in real time.

공대지항공무기체계 선정에 관한 연구(상)-레이저유도폭탄과 컴퓨터투하 재래식 폭탄을 중심으로

김응수,Kim, Eung-Su 한국방위산업진흥회 1985 國防과 技術 Vol.- No.71

EEG신호의 독립성분 분석과 소스 위치추정

김응수,Kim, Eung-Soo 한국정보처리학회 2002 정보처리학회논문지B Vol.9 No.1

뇌파(Electroencephalogram, EEG)는 뇌에서 막대한 수의 뉴런들의 전위차의 합으로 표현되는 시계열 전위차이다. 규칙적인 시간 간격으로 깊이를 가진 전극 측정에 의한 EEG로부터 서로 다른 구조를 가진 뇌에서의 뉴런 집단의 동역학을 평가할 수 있다. 최근에는 비선형 동역학 연구를 통해 뇌 기능 연구를 정량적으로 분석할 수 있는 방법이 개발되고 있다. 본 논문은 뇌파 신호를 분석함에 있어서 독립성분분석(Independent Component Analysis, ICA)의 적합성을 고려해 보았고, 15명의 정상인의 발가락 자극에 대한 EEG 신호에 이를 적용하여 독립 소스들을 분리해 내었다. 또한 Topological Hawing을 이용하여 각각의 독립 소스들의 기여도를 나타내었다. 이를 통하여 EEG에 독립성분분석을 적용함으로써 뇌 활동의 시간적, 공간적 분석이 가능하고 유용함을 나타내었다. The EEG is a time series of electrical potentials representing the sum of a very large number of neuronal dendrite potentials in the brain. The collective dynamic behavior of neural mass of different brain structures can be assessed from EEG with depth electrodes measurements at regular time intervals. In recent years, the theory of nonlinear dynamics has developed methods for quantitative analysis of brain function. In this paper, we considered it is reasonable or not for ICA apply to EEG analysis. Then we applied ICA to EEG for big toe movement and separated the independent components for 15 samples. The strength of each independent component can be represented on the topological map. We represented ICA can be applied for time and spatial analysis of EEG.

군사용 제어기기를 위한 마인드 컨트롤 인터페이스 기술

김응수,Kim, Eung-Su 대전대학교 군사연구원 2003 군사학연구 Vol.1 No.-

EEG is an electrical signal, which occurs during information processing in the brain. These EEG signals have been used clinically, but nowadays we are mainly studying Brain-Computer Interface (BCI) such as interfacing with a computer through the EEG, controlling the machine through the EEG. The ultimate purpose of BCI study is specifying the EEG at various mental states so as to control the computer and machine. This research makes the controlling system of directions with the artifact that are generated from the subject's will, for the purpose of controlling the machine correctly and reliably. We made the system like this. First, we select the particular artifact among the EEG mixed with artifact, then, recognize and classify the signals' pattern, then, change the signals to general signals that can be used by the controlling system of directions.

공대지항공무기체계 선정에 관한 연구(하)-레이저 유도폭탄과 컴퓨터 투하 재래식 폭탄을 중심으로

김응수,Kim, Eung-Su 한국방위산업진흥회 1985 國防과 技術 Vol.- No.73

활로 4징증 수술 전후 압력 측정치가 예후에 미치는 영향에 관한 연구

김응수,김근호,Kim, Eung-Su,Kim, Geun-Ho 대한흉부심장혈관외과학회 1987 Journal of Chest Surgery (J Chest Surg) Vol.20 No.1

Sixty-eight consecutive patients have been subjected to total corrective surgery of tetralogy of Fallot at the Hanyang University Hospital between August 1975 and December 1984. Of these, the pressure of chambers and great arteries were measured, before and immediately following an operation in 39 of the survived group and 11 of the expired group. The values of postoperative peak pressure were correlated with the outcome of the operation. The result are as followings; 1] Compared to the average peak pressure of right atrium in the survived group, 14.46*4.16 mmHg, that in the expired group, 19.36*8.19 mmHg, was significantly lower, 2] Compared to the average systolic pressure of right ventricle in the survived group, 56.72z16.37 mmHg, that in the expired group, 70.45*15.26 mmHg, was significantly lower. 3] Compared to the average systolic pressure of pulmonary artery in the survived group, 33.26*12.95 mmHg, that in the expired group, 37.55*11.63 mmHg, was higher. But the difference was not significant. 4] Compared to the average peak pressure of left atrium in the survived group, 17.41*6.90 mmHg, that in the expired group, 31.18*12.47 mmHg, was significantly higher. 5] Compared to the average systolic pressure of left ventricle in the survived group, 103.82~12.83 mmHg, that in the expired group, 90.55*20.02 mmHg, was significantly lower. 6] Compared to the average value of the right ventricle-pulmonary artery systolic pressure gradient [RV-PA] in the survived group, 24.95a15.44 mmHg, that in the expired group, 35.09*17.01 mmHg, was significantly higher. 7] Compared to the average value of the right ventricle to left ventricle systolic pressure ratio [RV/LV] in the survived group, 0.55*0.15, that in the expired group, 0.80a0.20, was significantly higher. 8] Compared to the average value of the pulmonary artery-left atrium peak pressure gradient [PA-LA] in 15.85x12.29 mmHg that in the expired group, 4.18x6.00 mmHg, was significantly lower. It is, therefore, suggested that in the operating room, PA-LA is as valuable as RV - PA, RV/LV in making important surgical decision and predicting the prognosis.

소련의 Ram-L 신형 전투기

김응수,Kim, Eung-Su 한국방위산업진흥회 1982 國防과 技術 Vol.- No.46

공대지항공무기체계 선정에 관한 연구(중)-레이저 유도폭탄과 컴퓨터 투하재래식폭탄을 중심으로

김응수,Kim, Eung-Su 한국방위산업진흥회 1985 國防과 技術 Vol.- No.72