• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.374-374
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• 2012

Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.

• 한국농공학회논문집
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• 제47권4호
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• pp.53-61
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• 2005

A series of laboratory tests was carried out fur analyzing of seepage characteristics of two-layers embankment model which consists of gravel and earth fill layers. Gravel layers were built under the earth fill for a half and one-third width of earth fill of the model. Permeability of earth fill was ranged between $5.00\times10^{-5}\~3.00\times10^{-4}\;m/s$.. The tests were performed with hydraulic gradients(i), $0.10\~0.55$. From the test results, hydraulic head of earth fill with gravel layer was 1.6 times higher than that of earth fill without gravel layer. Seepage rate was increased up to $4\~22$ times and safety factor for piping was decreased to $13\~43\;\%$ comparing the earth fill with gravel layer to that without gravel layer. The gravel layer under the earth fill could, in general, give some serious seepage problems to seadike embankment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.225-227
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• 2009

International standard specification, H.264/SVC improved from H.264/AVC, is set up so as to promote free use of huge multimedia data in various channel environments.;H.264/AVC is a international standard speicification for video compression, adopted and commercialized as standard for DMB broadcasting by JVT of ISO/IEC MPEG and ITU-T VCEG. SVC standard uses 'intra/inter prediction' in AVC as well as 'inter-layer intra prediction', 'inter-layer motion prediction' and 'inter-layer residual prediction' to improve efficiency of encoding. Among prediction technologies, 'inter-layer intra prediction' is to use co-located block of up sampled sublevels as a prediction signal. At this time, application of interpolation is one of the most important factors to determine encoding efficiency. SVC's currently using poly-phase FIR filter of 4-tap and 2-tap respectively to luma components. This paper is written for the purpose of analyzing encoding performance according to the interpolation. For this purpose, we applied poly-phase FIR filter of '2-tap', '4-tap' and '6-tap' respectively to luma components and then measured bit-rate, PNSR and running time of interpolation filter. We're expecting that the analysis results of this paper will be utilized for effective application of interpolation filter. SVC standard uses 'intra/inter prediction' in AVC as well as 'inter-layer intra prediction', 'inter-layer motion prediction' and 'inter-layer residual prediction' to improve efficiency of encoding.

• 전자공학회논문지B
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• 제31B권9호
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• pp.159-165
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• 1994

In this paper, we propose a multi-layer associative neural network structure suitable for hardware implementaion with the function of performance refinement and improved robutst capability. Unlike other methods which reduce network complexity by putting restrictions on synaptic weithts, we are imposing a requirement of hidden layer neurons for the function. The proposed network has synaptic weights obtainted by Hebbian rule between adjacent layer's memory patterns such as Kosko's BAM. This network can be extended to arbitary multi-layer network trainable with Genetic algorithm for getting hidden layer memory patterns starting with initial random binary patterns. Learning is done to minimize newly defined network error. The newly defined error is composed of the errors at input, hidden, and output layers. After learning, we have bidirectional recall process for performance improvement of the network with one-shot recall. Experimental results carried out on pattern recognition problems demonstrate its performace according to the parameter which represets relative significance of the hidden layer error over the sum of input and output layer errors, show that the proposed model has much better performance than that of Kosko's bidirectional associative memory (BAM), and show the performance increment due to the bidirectionality in recall process.

• 한국전기전자재료학회논문지
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• 제16권1호
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• pp.60-64
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• 2003

In this study, the inorganic thin-film passivation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam evaporation system, the various kinds of inorganic thin-films were deposited onto the organic layer and their interface properties between organic and inorganic layer were investigated. In this investigation, the MgO layer showed the most suitable properties, and based on this result, the time dependent emission properties were estimated for the OLED with and without passivation layer. In this experiment, we can see that the time-dependent emission properties of MgO passivated OLED had longer life-time compared to non-passivated OLED. Therefore, we can consider that the MgO thin film is one of the most suitable candidates for the thin-film passivation layer of OLED.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.68-68
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• 2010

Electroluminescence (EL) characteristics of green-emission ZnS:Cu,Cl-based ac-type inorganic powder electroluminescent structures were examined by inserting carbon nanotubes (CNTs) into or next to the dielectric layer. For the top-emission type EL structure, where the luminescent light was emitted from the top of the structure, was fabricated by assembling in order, a top electrode, an emitting layer, a dielectric layer, and a bottom electrode from the top. $BaTiO_3$ powder mixed with CNTs was used as a dielectric layer or CNTs were deposited between the bottom electrode and $BaTiO_3$ dielectric layer in order to improve the role of the dielectric layer in the structure. Luminance of an EL structure with CNTs inclusion was greatly enhanced possibly due to the high dielectric constant in the dielectric layer of $BaTiO_3$/CNTs, which is one of hot research topics utilizing nano-objects for intensifying dielectric constant and reducing dielectric loss at the same time. A variation on the CNTs themselves and their inclusion methods in the dielectric layer has been exhorted, and the underlying mechanism for the role of CNTs in the EL structure will be explained in the poster. In order to extend the flexibility of EL devices, EL devices were fabricated on the paper substrate and their performance was compared other EL devices on the plastic-based substrate.

• The Journal of the Acoustical Society of Korea
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• 제17권2E호
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• pp.26-30
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• 1998

In this paper, we compose neural network predictive HMM(NNPHMM) to provide the dynamic feature of the speech pattern for the HMM. The NNPHMM is the hybrid network of neura network and the HMM. The NNPHMM trained to predict the future vector, varies each time. It is used instead of the mean vector in the HMM. In the experiment, we compared the recognition abilities of the one hundred Korean syllables according to the variation of hidden layer, state number and prediction orders of the NNPHMM. The hidden layer of NNPHMM increased from 10 dimensions to 30 dimensions, the state number increased from 4 to 6 and the prediction orders increased from 10 dimensions to 30 dimension, the state number increased from 4 to 6 and the prediction orders increased from the second oder to the fourth order. The NNPHMM in the experiment is composed of multi-layer perceptron with one hidden layer and CMHMM. As a result of the experiment, the case of prediction order is the second, the average recognition rate increased 3.5% when the state number is changed from 4 to 5. The case of prediction order is the third, the recognition rate increased 4.0%, and the case of prediction order is fourth, the recognition rate increased 3.2%. But the recognition rate decreased when the state number is changed from 5 to 6.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.22-23
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• 2008

The conventional IGBT has two problems to make the device taking high performance. The one is high on state voltage drop associated with JFET region, the other is low breakdown voltage associated with concentrating the electric field on the junction of between p base and n drift. This paper is about the structure to effectively improve both the lower on state voltage drop and the higher breakdown voltage than the conventional IGBT. For the fabrication of the circular trench IGBT with the circular trench layer, it is necessary to perform the only one wet oxidation step for the circular trench layer. Analysis on both the on state voltage drop and the Breakdown voltage show the improved values compared to the conventional IGBT structure. Because the circular trench layer disperses electric field from p base and n drift junction to circular trench, the breakdown voltage increase. The on state voltage drop decrease due to reduction of JFET region and direction change of current path which pass through reversed layer channel.

• 한국전자파학회논문지
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• 제21권10호
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• pp.1121-1127
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• 2010

본 논문에서는 X-대역 Radant lens 4-bit 위상 변위기 설계에 필요한 $11.25^{\circ}$, $22.5^{\circ}$, $45^{\circ}$ 위상 변위 레이어(layer) 중에서 $45^{\circ}$ 레이어의 등가회로에 관하여 기술한다. $45^{\circ}$ 위상 변위 레이어에 대한 CST사의 MWS (Microwave Studio)와 Agilent사의 ADS(Advanced Design System) 시뮬레이션을 비교 분석하여 등가회로를 추출하고, 등가회로를 통해 얻을 수 있는 이론치와 측정치를 비교한다. 또한, 추출된 등가회로를 활용하여, 4-bit Radant lens의 위상 bit 시뮬레이션 결과도 제시한다.

• 한국표면공학회지
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• 제40권1호
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• pp.6-10
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• 2007

For low-emissivity application on window glass, coalescence of thin film silver islands is crucial for high transmittance in the visible and high reflectance in the infrared. It is well known that the underlayer affects the growth mode. In this work, the effect of the underlayer on the growth of silver films deposited by filtered cathodic vacuum arc is discussed. While a nominal 0.1 nm niobium underlayer has promoted the coalescence of silver islands, a 0.2 nm layer did not show these features. From a thermodynamic approach, Nb seeding less one monolayer is considered to reduce the surface energy between the silver atoms and $Nb/TiO_2$ surface, resulting the change of its growth from 3D islands to 2D-layer modes. If the seed layer exceeds one monolayer, however, a rougher surface is formed because the surface energy of Nb itself is superior to that of $Nb-TiO_2$. The onset of silver layer on the roughened Nb surface is required more silver.