LVT의 效率的인 管理運用 方案

김응수 해군대학 1982 海洋戰略 Vol.- No.11

Structural Characteristics and Microwave Dielectric Properties of CaW1−x(Mo1/2Te1/2)xO4 (0.01 ≤ x ≤ 0.17) Ceramics with (Mo1/2Te1/2)6+ Substitution

김응수,Joo Hyeon Kim 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.6

Microwave dielectric properties of CaW1−x(Mo1/2Te1/2)xO4 (0.01 ≤ x ≤ 0.17) ceramics with (Mo1/2Te1/2)6+ substitution wereinvestigated. For the specimens sintered at 825–950 °C for 3 h, a single phase of a scheelite structure was observed up tox = 0.13, while secondary phases were detected above x = 0.17. The relative densities of the specimens were higher than 95%,and the grain morphologies were uniform and clean for the entire range of compositions. The quality factor (Qf) dependedon the intrinsic factors such as the W-site bond characteristics of CaWO4evaluated by the bond valence and degree of covalency,and confirmed by the full width at half maximum of the internal mode peak of Raman spectroscopy. However, Qf wasalso affected by the extrinsic factors, such as the formation of the secondary phases, which showed the maximum Qf value(167,800 GHz) at x = 0.13 and then decreased. The dielectric constant (K) increased with (Mo1/2Te1/2)6+ substitution, whichwas affected by the dielectric polarizabilities of constituent ions. As the (Mo1/2Te1/2)6+ content increased, the temperature coefficient of resonant frequency (TCF) decreased, which was associated with an increase of oxygen bond valence.

안면근 신호를 이용한 문자 입력기의 개발

김응수 대한의료정보학회 2004 Healthcare Informatics Research Vol.10 No.2

A person does communication between each other using language. But, In the case of disabled person, he/she could not transfer own idea to others by using the writing or gesture. We embodied communication system using the facial muscle signals so that disabled person can do communication. After feature extraction from the facial muscle signals, it is converted to the control signal, and then disabled person could transfer his/her intention by select characters.

마이크로파 유전체 재료 및 응용

김응수 에스케이텔레콤 (주) 1993 Telecommunications Review Vol.3 No.8

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화학 기상 증착법으로 제조한 ReMnO₃(Re:Y, Ho, Er) 박막의 전기적 특성

김응수,채정훈,강승구,Kim, Eung-Soo,Chae, Jung-Hoon,Kang, Seung-Gu 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.12

MFS-FET(Metal-Ferroelectric-Semiconductor Field Effect Transistor) 구조의 비휘발성 기억소자용 $ReMnO_3$(Re:Y, Ho, Er) 박막을 금속 유기 화학 기상 증착법(MOCVD)으로 증착하였다. $ReMnO_3$ 박막을 Si(100) 기판 위에 700${\circ}C$-2시간 증착 시켜 결정화를 위해 대기 중에서 900${\circ}C$-1시간 열처리 시 육방정계(hexagonal) 단일상의 $ReMnO_3$ 박막을 형성하였다. 육방정계 단일상 구조에서 $ReMnO_3$ 박막의 강유전 특성은 c-축 배향성에 의존하였으며, c-축 배향성이 우수한 $YMnO_3$ 박막의 잔류 분극(Pr) 값은 105 nC/$cm^2$로 가장 우수하였다. 또한 누설 전류 밀도(leakage current density) 값은 미세구조의 결정립 크기에 의존하였으며, 결정립 크기가 100∼150 nm인 $YMnO_3$ 박막의 누설 전류 밀도 값은 인가전압 0.5 V에서 $10^{-8}$ A/$cm^2$을 나타내었다. $ReMnO_3$(Re:Y, Ho, Er) thin films were prepared by MOCVD method available to non-volatile memory device with MFS-FET structure. $ReMnO_3$ thin films were deposited on the Si(100) substrate at 700${\circ}C$ for 2h. When the films were post-annealed at 900${\circ}C$ for 1h in air, the single phase of hexagonal $ReMnO_3$ thin films were detected. Ferroelectric properties of $ReMnO_3$ thin films were dependent on the degree of c-axis orientation in the single phase of hexagonal structure and remnant polarization (Pr) of $YMnO_3$ thin films with high degree of c-axis orientation was 105 nC/$cm^2$. Leakage current density was dependent on the grain size of microstructure and that of $YMnO_3$ thin films with grain size of 100∼150 nm was $10^{-8}$ A/$cm^2$ at applied voltage of 0.5 V.

Microwave Dielectric Properties of (Pb0.4Ca0.6)(Fe1/2Nb1/2)1-x(Mg1/3Nb2/3)x]O3 Ceramics

김응수,김종희,한기문,윤기현 한국세라믹학회 2003 한국세라믹학회지 Vol.40 No.4

산화막위에 증착된 금속박막과 산화막과의 계면결합에 영향 미치는 열처리 효과

김응수 대한전자공학회 2004 電子工學會論文誌-SD (Semiconductor and devices) Vol.41 No.01

The interfacial layer between the oxide film and the metal film according to RTP annealing temperature of metal film has been studied. Two types of oxides, BPSG and PETEOS, were used as a bottom layer under multi-layered metal films. We observed the interface between oxide and metal films using SEM (scanning electron microscopy), TEM (transmission electron microscopy), AES (auger electron spectroscopy). Bonding failure was occurred by interfacial reaction between the BPSG oxide and the multi-layered metal films above 650℃ RTP anneal. The phosphorus accumulation layer was observed at interface between BPSG oxide and metal films by AES and TEM measurements. On the other hand, bonding was always good in the sample using PETEOS oxide as a bottom layer. We have known that adhesion between BPSG and multi-layered metal films was improved when the sample was annealed below 650℃. 산화막위에 증착된 금속박막과 산화막과의 계면효과를 조사하였다. 산화막으로는 현재 반도체소자제조공정에 많이 사용되고 있는 BPSG 산화막과 PETEOS 산화막을 사용하였다. 이 두 종류의 산화막위에 적층구조의 금속박막을 형성한 후, 금속박막의 열처리에 의한 계면의 영향을 SEM (scanning electron microscopy), TEM (transmission electron microscopy), AES (auger electron spectroscopy)를 사용하여 조사하였다. BPSG 산화막위에 증착된 금속박막을 650℃ 이상에서 RTP anneal을 한 경우, BPSG 산화막과 금속박막의 계면결합상태가 좋지 않았고, BPSG 산화막과 금속박막의 계면에 phosphorus가 축적된 영역을 확인하였다. 반면에 PETEOS 산화막위에 증착된 금속박막의 경우, RTP anneal 온도에 관계없이 계면결합상태는 좋았다. 본 연구에서 BPSG 산화막위에 금속박막을 증착할 경우 RTP anneal 온도는 650℃ 보다 작게 하여야 함을 알 수 있었다.

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.

ReMnO3(Re:Ho, Er) 박막의 강유전성에 미치는 열처리 공정의 영향

김응수,채정훈 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.11

Ferroelectric ReMnO3 (Re: Ho, Er) thin films were deposited on by metal-organic chemical vapor deposition (MOCVD). Crystallinity and electric properties of ReMnO3 (Re: Ho, Er) thin films were investigated as a function of thermal heat treatment process, CHP (conventional heat-treatment process) and RTP (rapid thermal process). ReMnO3 (Re: Ho, Er) thin films prepared by CHP showed higher c-axis preferred orientation and homogeneous surface roughness than those prepared by RTP. The remnant polarization of ferroelectric hysteresis loop of ReMnO3 (Re: Ho, Er) thin films was strongly dependent on the c-axis preferred orientation of hexagonal single phase, and the leakage current characteristics of thin films were dependent on the homogeneity of grain size as well as surface roughness of thin films. 강유전성 ReMnO3 (Re: Ho, Er) 박막을 금속 유기 화학 증착법(MOCVD)으로 증착한 후 CHP(Conventional Heat-treatment Process)와 RTP(Rapid Thermal Process)로 열처리 하여 열처리 공정 변화에 따른 박막의 결정성 및 전기적 특성을 조사하였다. ReMnO3 (Re: Ho, Er) 박막을 RTP로 열처리한 경우 CHP로 열처리한 경우 보다 우수한 c-축 우선 배향성을 나타내었으며 균일한 표면거칠기를 나타내었다. ReMnO3 (Re: Ho, Er) 박막의 강유전 이력곡선의 잔류분극(Pr)은 육방정계 단일상의 c-축 배향성에 크게 의존하였으며, 박막의 누설 전류 특성은 열처리 시 잔류 응력차이에 의한 미세구조 균일성 및 표면 거칠기에 의존하였다.