• Title/Summary/Keyword: model symmetry

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User Adaptation Using User Model in Intelligent Image Retrieval System (지능형 화상 검색 시스템에서의 사용자 모델을 이용한 사용자 적응)

  • Kim, Yong-Hwan;Rhee, Phill-Kyu
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.12
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    • pp.3559-3568
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    • 1999
  • The information overload with many information resources is an inevitable problem in modern electronic life. It is more difficult to search some information with user's information needs from an uncontrolled flood of many digital information resources, such as the internet which has been rapidly increased. So, many information retrieval systems have been researched and appeared. In text retrieval systems, they have met with user's information needs. While, in image retrieval systems, they have not properly dealt with user's information needs. In this paper, for resolving this problem, we proposed the intelligent user interface for image retrieval. It is based on HCOS(Human-Computer Symmetry) model which is a layed interaction model between a human and computer. Its' methodology is employed to reduce user's information overhead and semantic gap between user and systems. It is implemented with machine learning algorithms, decision tree and backpropagation neural network, for user adaptation capabilities of intelligent image retrieval system(IIRS).

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Study on the Statistical Optimum Model of Simple Linear Regression to Estimate the Purchasing Price of Diamond (다이아몬드 구매가격 예측을 위한 통계적 단순 선형회기 최적화 모형에 관한 연구)

  • 이영욱
    • The Journal of Information Technology
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    • v.3 no.1
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    • pp.37-44
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    • 2000
  • The purchasing estimate price of diamond is affected by the factors of carat, color, clarity, certificate, cut and price with the unit of $/carat. The object of this study is to obtain the linear regression model for such purchasing estimate price and to test statistically. The optimum model is the simple regression model of $^y{\;}:{\;}10^2{\;}/{\;}(-1.5575{\;}+{\;}0.3099{\;}logx){\;}+{\;}{\varepsilon}$ statistically satisfied by the lack of fit test and has the characteristics of normality, constant variance and symmetry.

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Simulation of Static Characteristics of Railway Vehicle's Airspring (철도차량용 공기 스프링의 정적 특성 시뮬레이션)

  • Heo, Sin;Gu, Jeong-Seo;U, Chang-Su;Kim, Yu-Il
    • 연구논문집
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    • s.26
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    • pp.15-24
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    • 1996
  • In this study, we performed the static analysis of a cord-reinforced rubber airspring and generated the three-dimensional half-symmetry model which use the finite-strain shell elements to model the airbag. the three-dimensional hydrostatic fluid elements to model the air-filled cavity, and the rebar elements to model the multi-ply nylon reinforcement of airbag. In addition, a three-dimensional rigid surface is used to define the contact between the airspring and metal bead. The air inside the airspring cavity has been modeled as a compressible fluid satisfying the ideal gas law. The conclusions of this study are as follows. 1) In the pressurization step of analysis, we could predict the change of vertical reaction force, cavity volume and pressure within the airspring. 2) In the second step of analyzing vertical static stiffness, the increase of the vertical load increases the vertical stiffness. 3) In case of changing the angle of nylon cord, the increase the angle of nylon cord increases the vertical stiffness.

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SHAPING A NOZZLE WITH A CENTRAL BODY (스파이크 노즐 설계)

  • KIM C. W.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.293-298
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    • 2005
  • We calculate the coordinates of an axisymmetric nozzle with a central body. This nozzle ensures a transonic flow with a plane sound surface, which is orthogonal to the symmetry axis and has a wall kink at the sonic point, The Chaplygin transformation in the subsonic part of the flow leads the Dirichlet problem for a system of nonlinear equations. The definition domain of the solution in the velocity-hodograph plane is taken as a rectangle. This enables one to obtain the nozzle with a monotonic distribution of velocity along its subsonic part. In the nonlinear differential equation, the linear Chaplygin operator for plane flows is separated, which allows the iterative calculation of the solution. The supersonic part of the nozzle is calculated under the assumption that the flow at the nozzle exit is uniform and parallel to the symmetry axis; i.e., the supersonic jet outflows to the submerged space with the same pressure. The calculation is performed by the characteristic method. The exact solution of Tricomi equation for near-sonic flows with the straight sonic line is used to 'move away' the sound plane. The velocity distribution alone the supersonic part of the nozzle is also monotonic, which ensures the absence of the boundary-layer separation and, therefore, the adequacy of the ideal-gas model. calculations show that the flow in the supersonic part of the nozzle is continuous (compression shocks are absent)

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Transmission Electron Microscopy of GaAs Planar Defects (투과전자현미경을 이용한 GaAs의 면결함 구조 연구)

  • Cho, N.H.;Hong, Kug Sun;Cater, C.B.
    • Analytical Science and Technology
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    • v.5 no.1
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    • pp.121-126
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    • 1992
  • Transmission electron microscopy was used to investigate the structure of GaAs ${\Sigma}=19$, [110] tilt grain boundaries. Relative positions of Ga and As atoms in each grain on either side of the boundaries were determined by examining the dynamical coupling between HOLZ reflections and(200) beams. No inversion symmetry was present across the boundaries. These boundaries were observed to have a strong tendency to lie parallel to {331} planes. The atomic structure and lattice translation at these boundaries was studied in detail by high-resolution transmission electron microscopy(HRTEM). The boundary consists of units of 5-, 7-, and two 6-member rings.

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SWR as Tool for Determination of the Surface Magnetic Anisotropy Energy Constant

  • Maksymowicz, L.J.;Lubecka, M.;Jablonski, R.
    • Journal of Magnetics
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    • v.3 no.4
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    • pp.105-111
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    • 1998
  • The low energy excitations of spin waves (SWR) in thin films can be used for determination of the surface anisotropy constant and the nonhomogeneities of magnetization in the close-to-surface layer. The dispersion relation in SWR is sensitive on the geometry of experiment. We report on temperature dependence of surface magnetic anisotropy energy constant in magnetic semiconductor thin films of$ CdCr_{2-2x}In_{2x}Se_4$ at spin glass state. Samples were deposited by rf sputtering technique on Corning glass substrate in controlled temperature conditions. Coexistence of the infinite ferromagnetic network (IFN) and finite spin slusters (FSC) in spin glass state (SG) is know phenomena. Some behavior typical for long range magnetic ordering is expected in samples at SG state. The spin wave resonance experiment (microwave spectrometer at X-band) with excited surface modes was applied to describe the energy state of surface spins. We determined the surface magnetic anisotropy energy constant versus temperature using the surface inhomogeneities model of magnetic thin films. It was found that two components contribute to the surface magnetic anisotropy energy. One originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the stray field of the surface roughness. The second one comes from the demagnetizing field of close-to surface layer with grad M. Both term linearly decrease when temperature is increased from 5 to 123 K, but dominant contribution is from the first component.

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Detection of Manufacturing Defects in Stiffness of CFTA Girder using Static Loading (정적 시험을 사용한 CFTA거더의 제조시 강성 결함 탐색)

  • Kim, Doo-Kie;Alfahdawi, Nathem;Cui, Jintao;Park, Kyung-Hoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.1
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    • pp.109-116
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    • 2012
  • This paper presents a study on the nonlinear behavior of an innovative bridge girder made from concrete-filled and tied tubular steel arch (CFTA) under static loading. Manufacturing of the CFTA girder may have defects which may highly affect the symmetry and performance of the structure. A simple method is proposed by using stiffness extracted from static test data to detect manufacturing defects of the CFTA girder. A three-dimensional finite element model was used in the numerical analysis in order to verify the method. The proposed method was experimentally validated through static tests of the CFTA girder. The application of the proposed method showed that it is effective in identifying invisible manufacturing defects of the CFTA girder, especially for mass production of a standard type in the factory.

Performance Evaluation of SDS-TWR Ranging Algorithms for CPS Based on Accurate Wireless Localization (정밀한 무선측위 기반 CPS를 위한 SDS-TWR 거리측정 기법의 성능 평가)

  • Yoo, Joonhyuk;Kim, Hiecheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.9
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    • pp.570-577
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    • 2014
  • Range-based real time localization systems require superior localization techniques as well as accurate ranging algorithms for better performance. To evaluate the ranging accuracy between two nodes in practical environments, this paper does not only present a qualitative analysis by computing a distance equation under SDS-TWR measurement model of no symmetry assumption, but also executes a quantitative evaluation by doing experiments after building up a test network employing the developed sensor node. Experimental results show that the ranging accuracy of the proposed implementation of IEEE 802.15.4a software stack is superior with smaller average error rate by 60% to one of the commercial Nanotron's reference development kit.

THEORETICAL ANALYSIS ON THE PHOTOCHEMISTRY OF COUMARIN DERIVATIVES

  • Kim, Ja-Hong;Sohn, Sung-Ho;Kim, Jung-Sung
    • Journal of Photoscience
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    • v.2 no.2
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    • pp.95-98
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    • 1995
  • The photodimers with cyclobutane rings and C$_2$ symmetry, derived from coumarin (syn, head to tail and anti, head to head) have been calculated by PM3-UHF-CI and Molecular Mechanics force field. The photocycloaddition to coumarin and 5,7-dimethoxycoumarin(DMC) dimers were deduced to be formed by their preferable frontier orbital interactions and via more stable cycloaddition by the C$_3$, C$_4$ bond. These results are consistent with the coumarin dimer model that the theoretical C$_4$-photocyclodimer of coumarin is predicted much more than the experimental C$_4$-photocyclodimer.

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A Study on the Posterior Density under the Bayes-empirical Bayes Models

  • Sohn, Joong-K.Sohn;Kim, Heon-Joo-Kim
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.215-223
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    • 1996
  • By using Tukey's generalized lambda distribution, appoximate posterior density is derived under the Bayes-empirical Bayes model. The sensitivity of posterior distribution to the hyperprior distribution is examined by using Tukey's generalized lambda distriburion which approximate many well-knmown distributions. Based upon Monte Varlo simulation studies it can be said that posterior distribution is sensitive to the cariance of the prior distribution and to the symmetry of the hyperprior distribution. Also posterior distribution is approximately obtained by using the following methods : Lindley method, Laplace method and Gibbs sampler method.

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