• Title/Summary/Keyword: Data dependence

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Classification of a binary group variable with dependece structure (종속구조를 가진 집단변수의 판별-분류에 관한 연구)

  • 황선영;나은정
    • The Korean Journal of Applied Statistics
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    • v.11 no.1
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    • pp.177-184
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    • 1998
  • Most of the research on discrimination and classification analysis has been directed to the situation where the data consist of independent observations. However, it is often the case in practice that a dependence structure between objects does exist, in particular, for the time series data. This article is handling such a case and is concerned with the problem of classifying new object when the dependence can be modelled by a discrete time series via conditional autologistic transition probability.

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The Measurement and Investigation of Fire and Explosion Properties for Acetone (아세톤의 화재 및 폭발 특성치 측정 및 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.25 no.4
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    • pp.30-35
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    • 2010
  • For the safe handling of acetone, the flash point, the explosion limit at $25^{\circ}C$ and the temperature dependence of the explosion limits were investigated. And the AIT for acetone were experimented. By using the literatures data, the lower and upper explosion limits of acetone recommended 2.5 vol% and 13.0 vol%, respectively. In this study, the lower flash points of acetone recommended $-20^{\circ}C$. This study was determined relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for acetone, and the experimental AIT of acetone was $565^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of acetone is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

Campers' Place Bonding: a Case Study in Worak-san National Park

  • Shin, Won Sop;Kim, Bum Soo
    • Journal of Korean Society of Forest Science
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    • v.94 no.2 s.159
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    • pp.90-95
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    • 2005
  • Place bonding, defined as the extent to which a person values or identifies with a particular environment, has focused as a research topic recently. This paper investigates the dimensions of place bonding for Worak-san National Park campers to enhance managers' ability to address deeper landscape meanings. Worak-san National Park campers (n=416) were surveyed during summer and fall of 2004 to collect the data. Confirmatory factor analysis of the data demonstrated that place bonding was composed of four dimensions such as place identity, familiarity, place dependence and place belongingness. The results of this study can provide valuation information for developing management actions to enhance park visitors' quality of recreational experiences.

Relaxation and Freezing in Pb-based Relaxer Ferroelectrics (Pb계 완화형 강유전체에서의 relaxation 및 freezing거동)

  • 박재환;김윤호;박재관
    • Korean Journal of Crystallography
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    • v.12 no.3
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    • pp.157-161
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    • 2001
  • The observe relaxation phenomena and freezing behavior in Pb(Mg/sub ⅓/Nb/sub ⅔/O₃, relaxor ferroelectrics, weak electric-field properties as well as strong electric-field properties were investigated. The temperature dependence of the dielectric properties obtained using the low electric-field of 1 V/w was investigated. The dielectric properties obtained from the slope of the dielectric hysteresis loop and the temperature dependence of the pyroelectric properties were also investigated. When fitting all the experimental data with the Vogel-Filcher relation, a close agreement between the experimental data and equation was observed. The freezing temperature could be consistently calculated by the various methods.

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The Measurement and Investigation of Combustible Properties for n-Hexane (노말헥산의 연소특성치의 측정 및 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.26 no.2
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    • pp.36-41
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    • 2011
  • For the safe handling of n-hexane, the explosion limit at $25^{\circ}C$, the temperature dependence of the explosion limits and the lower flash point were investigated. And AITs(auto-ignition temperatures) by ignition delay time for n-hexane were experimented. By using the literatures data, the lower and upper explosion limits of n-hexane recommended 1.0 Vol% and 8.0 Vol%, respectively. In this study, the lower flash points of n-hexane recommended $-23^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-hexane, and the experimental AIT of n-hexane was $240^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of n-hexane is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

A Study on Spin-Rotational Relaxation of Methyl Carbon-13 in Toluene and 2-Chloro-p-Xylene

  • Hyun Namgoong;Lee, Woong
    • Journal of the Korean Magnetic Resonance Society
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    • v.2 no.1
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    • pp.66-83
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    • 1998
  • Study on spin-rotation relaxation of nuclear spins located on a methyl group can reveal valuable dynamic information related to the internal rotation of methyl group itself. Toward this end we have measured methyl carbon-13 spin-rotation of methyl group itself. Toward this end we have measured methyl carbon-13 spin-rotational relaxation rate in toluene and 2-chloro-p-xylene over the temperature range of 179-363K. To interpret the temperature dependence of measured spin-rotational relaxation rate we have revised the temperature dependence of measured spin-rotational relaxation rate we have revised the expression derived thus far by other authors and reproduced experimental data on the basis of the newly derived expression. The results confirmed that our expression leads to better agreement with experimental data than the previous one over observed temperature range, especially at high temperature.

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Land Cover Super-resolution Mapping using Hopfield Neural Network for Simulated SPOT Image

  • Nguyen, Quang Minh
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.6_2
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    • pp.653-663
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    • 2012
  • Using soft classification, it is possible to obtain the land cover proportions from the remotely sensed image. These land cover proportions are then used as input data for a procedure called "super-resolution mapping" to produce the predicted hard land cover layers at higher resolution than the original remotely sensed image. Superresolution mapping can be implemented using a number of algorithms in which the Hopfield Neural Network (HNN) has showed some advantages. The HNN has improved the land cover classification through superresolution mapping greatly with the high resolution data. However, the super-resolution mapping is based on the spatial dependence assumption, therefore it is predicted that the accuracy of resulted land cover classes depends on the relative size of spatial features and the spatial resolution of the remotely sensed image. This research is to evaluate the capability of HNN to implement the super-resolution mapping for SPOT image to create higher resolution land cover classes with different zoom factor.

Empirical Equations for the Analysis of the Time Dependence of the Luminance Properties of LCD Panels and Backlights for TV Applications

  • Ryu, Jin-Sun;Kim, Su-Jin;Park, Seung-Mi;Ko, Jea-Hyeon
    • Journal of Information Display
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    • v.11 no.2
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    • pp.39-44
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    • 2010
  • The time dependences of the luminance properties of 55-inch CCFL and LED backlights and 32-inch FFL backlights with LCD panels were investigated during the warm-up time from the cold start. The long-term luminance maintenance curve of a standard CCFL was examined in a time window up to 5000 hours. These two time dependences are important characteristics from the viewpoint of initial picture quality and lifetime reliability, respectively. Empirical equations were suggested for the analysis of the time dependence of these luminance data. These approaches are expected to be helpful in predicting the luminance properties of backlights based on the luminance data obtained in a limited time window.

Computations of the Lyapunov exponents from time series

  • Kim, Dong-Seok;Park, Eun-Young
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.3
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    • pp.595-604
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    • 2012
  • In this article, we consider chaotic behavior happened in nonsmooth dynamical systems. To quantify such a behavior, a computation of Lyapunov exponents for chaotic orbits of a given nonsmooth dynamical system is focused. The Lyapunov exponent is a very important concept in chaotic theory, because this quantity measures the sensitive dependence on initial conditions in dynamical systems. Therefore, Lyapunov exponents can decide whether an orbit is chaos or not. To measure the sensitive dependence on initial conditions for nonsmooth dynamical systems, the calculation of Lyapunov exponent plays a key role, but in a theoretical point of view or based on the definition of Lyapunov exponents, Lyapunov exponents of nonsmooth orbit could not be calculated easily, because the Jacobian derivative at some point in the orbit may not exists. We use an algorithmic calculation method for computing Lyapunov exponents using time series for a two dimensional piecewise smooth dynamic system.

Analysis of X-ray luminosities of isolated elliptical galaxies in SDSS

  • Choi, Yun-Young;Kim, Eun-Bin;Kim, Sung-Soo S.;Park, Chang-Bom
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.58.2-58.2
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    • 2011
  • Park, Gott, & Choi (2008) found that when a galaxy is located within the virial radius from its closest neighbor and the neighbor is an elliptical, the probability of the galaxy to be an elliptical is very sensitive to the large-scale background density over a few Mpc scales. They suggested that the large-scale dependence can be arise if the temperature of a diffuse hot gas held by elliptical galaxies are higher in higher density environment. In this study, to understand the large-scale environment affects the X-ray properties of individual galaxies, we investigated the dependence of the X-ray luminosities of the elliptical galaxies on the large-scale environment using X-ray and optical data which we selected from the ROSAT All-Sky Survey and the Sloan Digital Sky Survey Data Release 7. To exclude galaxies embedded in an intra-group/cluster medium which could enhance their observed X-ray luminosity, we used isolated elliptical galaxies.

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