• Title/Summary/Keyword: 대각화

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ESR Study of Paramagnetic Defects of the ${\gamma}$-irradiated Potassium Sulfate Single Crystal (${\gamma}$-선에 조사된 황산칼륨 단결정의 상자성 결함에 관한 전자스핀공명 연구)

  • Yo Chul Hyun;Chung Won Yang;Jong In Hong;Eun Ok Kim;Jung Sung Yang
    • Journal of the Korean Chemical Society
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    • v.25 no.6
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    • pp.367-375
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    • 1981
  • Single crystals of Potassium Sulfate ($K_2SO_4$) have been grown from the saturated solution by the evaporation method at the optimum conditions. Radiation damages in the crystal by ${\gamma}$-irradiation of about $12{\times}10^6$ Roentgen have given rise to paramagnetic centers or paramagnetic defects. Electron spin resonance (ESR) spectra of the centers are obtained with the X-band EPR spectrometer at room temperature. The ESR peaks of the paramagnetic species are found to be anisotropic but the peak of $SO_3-$ radical is an isotropic of Gaussian shape at g = 2.0036. A number of ESR spectra of the crystal for angular variation of the anisotropic peaks are recorded at various orientations of rotation about a, b and c crystallographic axes respectively. The g-values are calculated from the line position between anisotropic peaks and the isotropic one and then principal g-values and its direction cosines of the species are obtained by diagonalization of 9 matrix elements of the corresponding g-values. All the paramagnetic defects are identified by the characteristic principal g-values and its direction cosines.

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ESR Study on Paramagnetic Defects of the ${\gamma}$-Irradiated Sodium Thiosulfate Single Crystal (${\gamma}$-선에 조사된 티오황산나트륨 단결정의 상자성 결함에 관한 전자스핀공명 연구)

  • Jung Sung Yang
    • Journal of the Korean Chemical Society
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    • v.27 no.4
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    • pp.244-254
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    • 1983
  • Single crystals of sodium thiosulfate $(Na_2S_2O_3) have been grown from the saturated solution by the evaporation method at the optimum condition. Radiation damages in the crystal by ${\gamma}$-irradiation of $20{\times}10^6$ Rontgen have given rise to paramagnetic centers. The anisotropic spectra of each paramagnetic species have been obtained with the X-band EPR spectrometer at room temperature. When an isotropic D.P.P.H. at g value of 2.0036 is based on. ESR Spectra of the single crystal are recorded for each rotation about the perpendicular a, b and c axis with intervals of $10^{\circ}$ from $0^{\circ}$to $180^{\circ}$ in order to find out the properties of the crystal for anglar variation of the anisotropic peaks. The g values are calculated from the line position between the anisotropic peaks and the isotropic peaks of D.P.P.H. and then principal g values and their direction cosines of the species is obtained by the diagonalization of 9 matrix elements of the corresponding g values. From the analysis of the characteristic principal g values and direction cosines for ${\gamma}$-irradiated $Na_2S_2O_3$ crystal, anisotropic peaks corresponding to $SO_2^+, SO_2^- $are identified and the existences of unidentified and unstable paramagnetic defects are verified.

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Adaptive Block Recovery Based on Subband Energy and DC Value in Wavelet Domain (웨이블릿 부대역의 에너지와 DC 값에 근거한 적응적 블록 복구)

  • Hyun, Seung-Hwa;Eom, Il-Kyu;Kim, Yoo-Shin
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.5 s.305
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    • pp.95-102
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    • 2005
  • When images compressed with block-based compression techniques are transmitted over a noisy channel, unexpected block losses occur. In this paper, we present a post-processing-based block recovery scheme using Haar wavelet features. No consideration of the edge-direction, when recover the lost blocks, can cause block-blurring effects. The proposed directional recovery method in this paper is effective for the strong edge because exploit the varying neighboring blocks adaptively according to the edges and the directional information in the image. First, the adaptive selection of neighbor blocks is performed based on the energy of wavelet subbands (EWS) and difference of DC values (DDC). The lost blocks are recovered by the linear interpolation in the spatial domain using selected blocks. The method using only EWS performs well for horizontal and vertical edges, but not as well for diagonal edges. Conversely, only using DDC performs well diagonal edges with the exception of line- or roof-type edge profiles. Therefore, we combined EWS and DDC for better results. The proposed methods out performed the previous methods using fixed blocks.

Joint Base Station and Relay Precoder Design with Relay Local Channel State Information for Multi-relay Aided Multi-user All-MIMO System (다중 릴레이, 다중 사용자 All-MIMO 시스템에서 릴레이 지역 채널 정보를 사용한 기지국 및 릴레이 전처리기 공동 설계 기법)

  • Cho, Young-Min;Jang, Seung-Jun;Kim, Dong-Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.6A
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    • pp.405-419
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    • 2012
  • In this paper, we propose a joint base station(BS) and relay precoders design in multi-relay aided multi-user all-multiple-input multiple-output(MIMO) system. The design criterion is to minimize user sum mean square error(SMSE) with relay sum power constraint(RSPC) where only local channel state information(CSI)s are available at relays. Local CSI at a relay is defined as the CSI of the channel which the relay itself accesses, out of among all the 1st hop and the 2nd hop channel in the system. With BS precoder structure which is concatenated with block diagonalization(BD) precoder, each relay can determine its own precoder using only local CSI. Proposed scheme is based on sequential iteration of two stages; stage 1 determines BS precoder and relay precoders jointly with SMSE duality, and stage 2 determines user receivers. Proposed scheme can be demonstrated theoretically to be always converge. We verify that proposed scheme outperforms simple amplify-and-forward(SAF), MMSE relay, and proposed schemes in [1] in terms of both SMSE and sum-rate performances.

SINR Maximizing Collaborative Beamforming with Enhanced Robustness Against Antenna Correlation (안테나 간 상관도에 강건한 SINR 최대화 협력적 빔포밍 기법)

  • Kim, Jae-Won;Sung, Won-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.4
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    • pp.95-103
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    • 2009
  • In this paper, a generation method of transmit and receive beamforming vectors based on base station cooperation is proposed which maximizes the user SINR in mobile cellular multi-user MIMO systems. There are two main sources of interference which deteriorate the performance of the system, i.e. the inter-user interference caused by the usage of the same radio resource for multiple users in the system, and the inter-cluster interference from neighboring base stations which are not participating in cooperative transmission. The proposed scheme cancels out the inter-user interference by using the block diagonalization(BD) method, and mitigate the inter-cluster interference by using optimal transmit and receive beamforming vectors based on optimal combining(OC) with the statistic information of inter-cluster interference. We perform computer simulations to verify the performance of the proposed scheme, and compare the result to the conventional performance obtained from utilizing the receiver side information only or utilizing the information from neither sides. The performance evaluations are conducted not only over the independent MIMO channels, but over correlated MIMO channels to demonstrate the robustness of the proposed scheme over the channels with correlation among antennas.

Wavelet-Based Image Compression Using the Properties of Subbands (대역의 특성을 이용한 웨이블렛 기반 영상 압축 부호화)

  • 박성완;강의성;문동영;고성제
    • Journal of Broadcast Engineering
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    • v.1 no.2
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    • pp.118-132
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    • 1996
  • This paper proposes a wavelet transform- based image compression method using the energy distribution. The proposed method Involves two steps. First, we use a wavelet transform for the subband decomposition. The original image Is decomposed into one low resolution subimage and three high frequency subimages. Each high frequency subimages have horizontal, vertical, and diagonal directional edges. The wavelet transform is luther applied to these high frequency subimages. Resultant transformed subimages have different energy distributions corresponding to different orientation of the high pass filter. Second, for higer compression ratio and computational effciency, we discard some subimages with small energy. The remaining subimages are encoded using either DPCM or quantization followed by entropy coding. Experimental results show that the proposed coding scheme has better performance in the peak signal to noise ratio(PSNR) and higher compression ratio than conventional image coding method using the wavelet transform followed by the straightforward vector quantization.

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Immunohistochemical and Ultrastructural Characterization of the Choline Acetyltransferase-immunoreactive Nerve Cells in the Diagonal Band of Broca of the Rat Basal Forebrains (흰쥐의 전뇌 기저부 대각 Broca대에서 Choline Acetyltransferase 면역반응 신경세포에 대한 면역조직화학 및 미세구조)

  • Back, Seung-Keun;Chung, Young-Wha
    • Applied Microscopy
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    • v.29 no.3
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    • pp.383-403
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    • 1999
  • This study was performed to investigate the immunohistochemical and ultrastructural characterization of the choline acetyltransferase (ChAT)-immunoreactive nerve cells in the diagonal band of Broca of the rat basal forebrains, utilizing techniques of immunohistochemical and immunocytochemical microscopy. The ChAT-immunoreactivities were shown within neuronal cell bodies and processes by the light micoscope. According to cell shape and ratio of long axis vs short axis of cell body, the ChAT-immunoreaclive nerve cells in both vertical and horizontal limbs of the diagonal band of Broca were classified into 6 types. at the light microscopic level; round, oval, elongated, fusiform, triangular and polygonal types. As a result of the electron microscopic observation, the ChAT-immunoreactivated products appeared on the outer nuclear envelope, membranes of rough endoplasmic reticula (rER), free ribosomes and polysomes. Each cell type was subdivided into subtype I and II according to the several criteria such as volume of cell body, nuclear size relative to the cytoplasm, kinds and distribution of cell organelles and numbers and sorts of synapses. The subtype I of immnunoreactive nerve cells had large cell body and a small nucleus showing shallow indentations of nuclear evelope. In this subtype I with abundant cytoplasm, rER were well differentiated. Their long cisternae were parallelly ditributed and lamellated. One or two lamellar bodies and nematosomes were observed. The subtype II cell had small cell body and a large nucleus with deep indentations of nuclear envelope. In this subtype II with small cytoplasm, the rER were irregularly distributed and the lamellar body and nematosome were not found. A few axosomatic synapses in the subtype I and II were shown to be symmetric or asymmetric. The ratios of the symmetric synapse to the asymmetric one were investigated to be 1 : 2 and 1 : 4 in the subtype I and II, respectively. The axodendritic ones were almost asymmetric. But, the fusiform and triangular immunoreactive nerve cells were shown only to be subtype I. According to observations in this study, it is considered that the ultrastructural characterization in the 2 subtypes of each cell type may reflect the differences of the metabolic activities and projecting distances to the target cells.

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Nonlinear Analysis of RC Members Using Truss Model (트러스 모델을 이용한 철근콘크리트 부재의 비선형해석)

  • Eom, Tae-Sung;Park, Hong-Gun
    • Journal of the Korea Concrete Institute
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    • v.18 no.2 s.92
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    • pp.177-188
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    • 2006
  • Conventional nonlinear finite element analysis requires complicated modeling and analytical technique. Furthermore, it is difficult to interpret the analytical results presented as the stress-strain relationship. In the present study, a design-oriented analytical method using the truss model was developed. A reinforced concrete member to be analyzed was idealized by longitudinal, transverse, and diagonal line elements. Basically, each element was modeled as a composite element of concrete and re-bars. Simplified cyclic models for the concrete and re-bar elements were developed. RC beams and walls with various reinforcement details were analyzed by the proposed method. The inelastic strength, energy dissipation capacity, deformability, and failure mode predicted by the proposed method were compared with those of existing experiments. The results showed that the proposed model accurately predicted the strength and energy dissipation capacities, and to predict deformability of the members, the compression-softening model used for the concrete strut element must be improved.

Model Verification Algorithm for ATM Security System (ATM 보안 시스템을 위한 모델 인증 알고리즘)

  • Jeong, Heon;Lim, Chun-Hwan;Pyeon, Suk-Bum
    • Journal of the Institute of Electronics Engineers of Korea TE
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    • v.37 no.3
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    • pp.72-78
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    • 2000
  • In this study, we propose a model verification algorithm based on DCT and neural network for ATM security system. We construct database about facial images after capturing thirty persons facial images in the same lumination and distance. To simulate model verification, we capture four learning images and test images per a man. After detecting edge in facial images, we detect a characteristic area of square shape using edge distribution in facial images. Characteristic area contains eye bows, eyes, nose, mouth and cheek. We extract characteristic vectors to calculate diagonally coefficients sum after obtaining DCT coefficients about characteristic area. Characteristic vectors is normalized between +1 and -1, and then used for input vectors of neural networks. Not considering passwords, simulations results showed 100% verification rate when facial images were learned and 92% verification rate when facial images weren't learned. But considering passwords, the proposed algorithm showed 100% verification rate in case of two simulations.

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A Study on Wave Transformation Analysis using Higher-Order Finite Element (고차유한요소의 파랑변형해석에의 적용에 관한 소고)

  • Jung, Tae-Hwa;Lee, Jong-In;Kim, Young-Taek;Ryu, Yong-Uk
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.2
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    • pp.108-116
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    • 2009
  • The present study introduces a Legendre interpolation function which is capable of analyzing wave transformation effectively in a finite element method. A Lagrangian interpolation function has been mostly used for a finite element method with a higher-order interpolation function. Although this function has an advantage of giving an accurate result with less number of elements, simulation time increases. Calculation time can be reduced by mass lumping, whereas the accuracy of solution is lowered. In this study, we introduce a modified Lagrangian interpolation function, Legendre cardinal interpolation, which can reduce simulation time with keeping up favorable accuracy. Through various numerical simulations using a Boussinesq equations model, the superiority of the Legendre cardinal interpolation function to a Lagrangian interpolation function was shown.