• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1129-1132
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• 1995

In the preparation of the layered $BaTiO_3$ thin films with high performance, the new stacking method using the continuous cooling of the substrate was introduced. Amorphous/polycrystalline $BaTiO_3$ layered structure was confirmed by SEM and index of refraction. The layered $BaTiO_3$ thin films formed by the new stacking method showed such a high dielectric constant that the layered structure could not be explained by a stacking structure of the two defined layers but could only be explained by multi-layered structure, i.e. amorphous/micro crystalline/polycrystalline structure. The layered $BaTiO_3$ thin film with a thickness of 240 nm showed higher capacitance per unit area and breakdown strength than the double layered $BaTiO_3$ thin film prepared by the conventional stacking method. And well defined ferroelectric hysteresis leer was observed in the layered $BaTiO_3$ thin film with a thickness of 200 nm.

• 스마트미디어저널
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• 제5권1호
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• pp.104-113
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• 2016

본 논문은 쌓임 규칙에 기반한 복합기능을 가진 풀다운메뉴의 새로운 설계 방법을 제안한다. 기존의 웹 내비게이션 관련 연구에서는 디자인적인 측면을 강조한 내용이 대부분이다. 본 논문은 프로그래밍기법에 주안점을 둔 기술적인 측면을 고려하여 다수의 엘리먼트로 풀다운메뉴의 메인메뉴를 구성하고, 이들을 쌓임 규칙을 이용하여 서로 다른 레이어에 배치함으로써 메인메뉴의 기본적인 분류기능 이외에 독립적으로 고유의 기능을 할 수 있다. 또한 본 논문에서 제안한 애니메이션기법을 사용한 서브메뉴 선택 바와 서브메뉴 항목 자동 탐색 기능을 추가하여 시각적인 효과와 정보탐색 효율을 향상할 수 있다. 본 논문에서 제안한 복합기능을 갖는 풀다운메뉴를 CSS와 jQuery를 사용하여 구현함으로써 제안한 방법의 유효성을 확인하였다.

• 한국전자거래학회지
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• 제25권3호
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• pp.1-13
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• 2020

기계학습(machine learning)이란 주어진 데이터에 대한 일반화 과정으로부터 특정 문제를 해결할 수 있는 모델(model) 생성 기술을 의미한다. 우수한 성능의 모델을 생성하기 위해서는 양질의 학습데이터와 일반화 과정을 위한 학습 알고리즘이 준비되어야 한다. 성능 개선을 위한 한 가지 방법으로서 앙상블(Ensemble) 기법은 단일 모델(single model)을 생성하기보다 다중 모델을 생성하며, 이는 배깅(Bagging), 부스팅(Boosting), 스태킹(Stacking) 학습 기법을 포함한다. 본 논문은 기존 스태킹 기법을 개선한 다중 스태킹 앙상블(Multiple Stacking Ensemble) 학습 기법을 제안한다. 다중 스태킹 앙상블 기법의 학습 구조는 딥러닝 구조와 유사하고 각 레이어가 스태킹 모델의 조합으로 구성되며 계층의 수를 증가시켜 각 계층의 오분류율을 최소화하여 성능을 개선한다. 4가지 유형의 데이터셋을 이용한 실험을 통해 제안 기법이 기존 기법에 비해 분류 성능이 우수함을 보인다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2005년도 ISMP
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• pp.89-110
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• 2005

A new 3D integration technology using wafer-to-wafer and chip-to-wafer stacking method was described. It was demonstrated that 3D microprocessor, 3D shared memory, 3D image processing chip and 3D artificial retina chip fabricated using 3D integration technology were successfully operated. The possibility of applying 3D image processing chip and 3D artificial retina chip to Robot's eye was investigated. The possibility of implanting 3D artificial retina chip into human eye was investigated.

• 한국세라믹학회지
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• 제34권2호
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• pp.181-187
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• 1997

다결정 BaTiO3 박막의 높은 유전상수와 비정질 BaTiO3 박막의 우수한 절연특성을 함께 지닌 적층구조 BaTiO3 박막을 제조하여 적층방법에 따른 전기적 특성을 비교, 평가하였다. BaTiO3 박막은 ITO 투명전전막이 입혀진 유리기판위에 rf=magnetron sputtering방법으로 형성하였으며 적층구조 BaTiO3박막의 제조에는 다결정 BaTiO3 박막의 상부에 기판의 자연 냉각과정중에 비정질층이 형성되는 새로운 적층방법을 사용하였다. 이와같이 제조된 적층박막은 다결정 BaTiO3 박막의 상부에 상온에서 비정질층을 형성시키는 일반적인 적층방법으로 제조한 적층박막에 비하여 높은 단위면적당 정전용량과 유전상수, 우수한 절연특성을 나타내었다. 일반적인 적층방법에 의하여 이중층 구조가 형성되는 반면, 새로운 적층방법으로 제조된 적층박막은 AES depth profile과 전기적 특성 분석을 통하여 비정질/microcrystalline/다결정 구조의 다층구조를 지닌 것으로 확인되었다.

• 한국가구학회지
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• 제18권4호
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• pp.296-306
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• 2007

As life style changes, the demand for stacking chairs are increasing as the use of event halls or outside furniture where people gather in crowd is increasing. Early stacking chairs were mainly made to pile up a great amount and store, but in modern days it also has a decorative purpose. Besides, the development of various new materials and applied technology of furniture manufacture, the structure and design of stacking chair is becoming more interesting. Basically, according to the structure of the leg, the form and method of piling up is decided. The structure of the leg means the location of the leg connected to the seat, and according to the location, it can be piled up as upper, front, or rotational type. Such is the way how stacking chairs are classified according to the location of the leg, with its basis; the structure of stacking chair is reviewed. Now, chair for piling up is overcoming its simple function, which aesthetic beauty or arrangement of color after piling up is being considered. Also, according to storing, moving, and the place of use, various designs are demanded. As people's interest in stacking chair is increasing, various research regarding design should continue.

• Advanced Composite Materials
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• 제18권4호
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• pp.297-314
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• 2009

A design method is proposed to optimize the stacking sequence of laminated composite plates for desired vibration characteristics. The objective functions are the natural frequencies of the laminated plates, and three types of optimization problems are studied where the fundamental frequency and the difference of two adjacent frequencies are maximized, and the difference between the target and actual frequencies is minimized. The design variables are a set of discrete values of fiber orientation angles with prescribed increment in the layers of the plates. The four lamination parameters are used to describe the bending property of a symmetrically laminated plate, and are optimized by a gradient method in the first stage. A new technique is introduced in the second stage to convert from the optimum four lamination parameters into the stacking sequence that is composed of the optimum fiber orientation angles of all the layers. Plates are divided into sub-domains composed of the small number of layers and designed sequentially from outer domains. For each domain, the optimum angles are determined by minimizing the errors between the optimum lamination parameters obtained in the first step and the parameters for all possible discrete stacking sequence designs. It is shown in numerical examples that this design method can provide with accurate optimum solutions for the stacking sequence of vibrating composite plates with various boundary conditions.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.639-645
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• 2003

Design optimization of a transonic compressor rotor (NASA rotor 37) using response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. Baldwin-Lomax turbulence model was used in the flow analysis. Two design variables were selected to optimize the stacking line of the blade, and mass flow was used as a design variable, as well, to obtain new design point at peak efficiency. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved, and new design mass flow that is appropriate to an improved blade was obtained. Also, it is found that the design process provides reliable design of a turbomachinery blade with reasonable computing time.

• 한국세라믹학회지
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• 제32권7호
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• pp.761-768
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• 1995

Double layered BaTiO3 thin films with high dielectric constant as well as good insulating property were prepared for the application to low voltage driving thin film electroluminescent (TFEL) device. BaTiO3 thin films were formed by rf-magnetron sputtering technique. Amorphous and polycrystalline BaTiO3 thin films were deposited at the substrate temperatures of room temperature and 55$0^{\circ}C$, respectively. Two kinds of films prepared under these conditions showed high resistivity and high dielectric constant. The figure of merit (=$\varepsilon$r$\times$Eb.d) of polycrystalline BaTiO3 thin film was very high (8.43$\mu$C/$\textrm{cm}^2$). The polycrystalline BaTiO3 showed a substantial amount of leakage current (I), under the high electric field above 0.5 MV/cm. The double layered BaTiO3 thin film, i.e., amorphous BaTiO3 layer coated polycrystalline BaTiO3 thin film, was prepared by the new stacking method and showed very good dielectric and insulating properties. It showed a high dielectric constant fo 95 and leakage current density of 25 nA/$\textrm{cm}^2$ (0.3MV/cm) with the figure of merit of 20$\mu$C/$\textrm{cm}^2$. The leakage current density in the double layered BaTiO3 was much smaller than that in polycrystalline BaTiO3 under the high electric field. The saturated brightness of the devices using double layered BaTiO3 was about 220cd/$m^2$. Threshold voltage of TFEL devices fabricated on double layered BaTiO3 decreased by 50V compared to the EL devices fabricated on amorphous BaTiO3.

• 전기학회논문지
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• 제63권3호
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• pp.395-403
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• 2014

This paper presents a new approach to improve the signal to noise ratio (SNR) for local seismic disaster preventing system in densely populated area. The seismic data measured in the local site includes various sensing noises (offset or measurement noise) and man-made/natural noises (road and rail traffic noise, rotating or hammering machinery noise, human activity noise such as walking and running, wind/atmospheric pressure-generated noise, etc.). These additive noises are different in time and frequency characters. The proposed method uses 3-stages processing to reduce these different additive noises. In the first stage, misalignment offset noise are diminished by time average processing, and then the second and third stages, coherent/incoherent noises such as man-made/natural noises are suppressed by array stacking. In addition, we derived the theoretical equation of the SNR gain improved by the proposed method. To evaluate the performance of the proposed method, computer simulations were performed with real seismic data and test equipment generated data as the input.