• 대한소아치과학회지
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• 제37권2호
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• pp.159-167
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• 2010

유치열에 존재하는 우식패턴을 연구하기 위하여 유치열을 가진 유아들을 대상으로 치면별 우식경험도 조사를 실시하고 군 집분석과 다차원척도분석을 실시하였다. 연구대상은 36개월 이상 71개월 이하의 어린이 815명이었다. 군집분석에서 먼저 분리된 네 개의 군집은, 유치는 (1) 유구치, (2) 상악 유절치, (3) 하악 제1유구치, (4) 상악 제1유구치, 유치면은 (1) 하악 유구치 교합면과 상악 제2유구치 교합면, (2) 상악 유중절치 근심면, (3) 하악 제1유구치 교합면, (4) 상하악 제2유구치 교 합면의 분리, 유치면군은 (1) 상악 유전치 인접면, (2) 하악 유구치 교합면, (3) 상악 유전치 협설면, (4) 상악 유구치 협설 면, 인접면, 교합면 및 하악 유구치 협설면과 인접면이었다. 다차원척도분석에서 상호간에 가장 멀리 떨어진 순서로 보았을 때, 유치는 하악 제1유구치, 상악 제1유구치, 상악 유중절치, 상악 유측절치, 하악 제2유구치, 상악 제2유구치, 기타 유치(유견치, 하악 유절치)로 나눌 수 있었고, 유치면은 하악 유구치 교합면, 상악 유중절치 근심면, 상악 유구치 교합면, 기타 유치 면으로 나눌 수 있었으며, 유치면군은 상악 유전치 인접면, 상악 유전치 협설면, 하악 유구치 교합면, 기타 유치면군으로 나눌 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1847-1852
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• 2004

This article provides the connection between feedback stabilization and interpolation conditions for n-D linear systems (n > 1). In addition to internal stability, if one demands performance as a design goal, then there results an n-D matrix Nevanlinna-Pick interpolation problem. Application of recent work on Nevanlinna-Pick interpolation on the polydisk yields a solution of the problem for the 2-D case. The same analysis applies in the n-D case (n > 2), but leads to solutions which are contractive in a norm (the "Schur-Agler norm") somewhat stronger than the $H^{\infty}$ norm. This is an analogous version of the connection between the standard $H^{\infty}$ control problem and an interpolation problem of Nevanlinna-Pick type in the classical 1-D linear time-invariant systems.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1997년도 추계학술대회발표논문집; 홍익대학교, 서울; 1 Nov. 1997
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• pp.63-66
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• 1997

This paper is concerned with the current status and the prospectus of environmental investments in the manufacturing sector. A questionnaire survey was made to identify the concentrated fields of the investments. The collected data were analyzed by a multidimensional scaling method in order to provide a reasonable interpretation on the major factors which characterize the current situation and the prospectus of the investments as well as the relative position of each respondent company in a spatial map. The result tells us most respondents tend to concentrate their attention on end-of-pipe solutions due to technological tangibility and economic efficiency, etc.

• 한국주거학회논문집
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• 제1권2호
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• pp.1-11
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• 1990

A study of domestic furniture arrangements may reveal the living style relevant to the room as conceived and coded by occupants and the effects of the physical environment on the structure of behavior settings. The purpose of this study was to investigate, through analizing the furniture usage and behavior as a non-reactive and activity oriented behavioral measures, the occupants` domestic habits as a living style using MDS. MDS(multidimensional scaling technique) is a statistical technique for creating a spatial representation of data. It Is a particularly appropriate technique for analizing qualitative data such as the furniture usage and behavior because it takes into account all of the relationships between items. For the MDS analysis, the furniture usage and behavior examined by housing types based on 114 households in Seoul. The result of spatial configuration by MDS has three dimensions : recogn;lion of room function, pattern of room organization, understanding of room meaning. The effect of housing types for dimensions is identical but configuration of furniture items is different.

• Journal of Mechanical Science and Technology
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• 제15권8호
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• pp.1196-1204
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• 2001

The effects of EGR(Exhaust Gas Recirculation) on heavy-duty diesel engine performance, NO and soot emissions were numerically investigated using the modified KIVA-3V code. For the fuel spray, the atomization model based on the linear stability analysis and spray wall impingement model were developed for the KIVA-3V code. The Zeldovich mechanism for the formation of nitric oxide and the soot model suggested by Hiroyasu et al. were used to predict the diesel emissions. In this paper, the computational results of fuel spray, cylinder pressure, and emissions were compared with experimental data, and the optimum EGR rates were sought from the NO and soot emissions trade-off. The results showed that the EGR is effective in suppressing NO but the soot emission was increased considerably by EGR. Using cooled EGR, soot emission could be enhanced without worsening of NO.

• 한국통신학회논문지
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• 제15권12호
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• pp.990-1001
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• 1990

이 논문은 격자 부호화 방식을 비교, 분석한 것으로, 구조 및 설계에 대한 기본 개념을 논의하였다. 격자 부호화 변조에 대한 부호 이득의 추정 방법과 착오 계수 효과에 대하여 이론적으로 고찰하고, 음성대역 모뎀에서의 다차원 부호화 및 차동적 부호화의 변조 방법에 대해 신호 공간 분석을 하였다. 결과적으로 16차원적 신호점 배치법이 2차원적 신호점 배치보다 우수하다는 결론을 얻었다.

• 아동학회지
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• 제21권2호
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• pp.99-118
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• 2000

This study investigated the self-concepts of Korean students based on Marsh and Shavelson's(1985) multidimensional hierarchical model. Reduced forms of the Self-Description Questionnaire(SDQ)-I and -II were administered to 308 5th and 6th grade students and 718 7th to 9th grade students. Results of 2 factor analyses indicated that sub-scales 9 and 11 were well established for SDQ-I and -II, respectively, partly confirming the multidimensionality of self-concept. The factors involving distinctions between academic and non-academic higher-order factors and between the academic/math and the academic/verbal factors were not so differentiated nor hierarchically arranged as proposed by the model. These differences may be attributed to the heavy influence of the academic self-concept on the other sub-factors. A Locality ${\times}$ Sex ${\times}$ Grade ANOVA showed main effects of locality favoring urban areas and of sex favoring boys.

• Communications for Statistical Applications and Methods
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• 제26권4호
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• pp.371-383
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• 2019

Panel data sets have been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Maximum likelihood (ML) may be the most common statistical method for analyzing panel data models; however, the inference based on the ML estimate will have an inflated Type I error because the ML method tends to give a downwardly biased estimate of variance components when the sample size is small. The under estimation could be severe when data is incomplete. This paper proposes the restricted maximum likelihood (REML) method for a random effects panel data model with a censored dependent variable. Note that the likelihood function of the model is complex in that it includes a multidimensional integral. Many authors proposed to use integral approximation methods for the computation of likelihood function; however, it is well known that integral approximation methods are inadequate for high dimensional integrals in practice. This paper introduces to use the moments of truncated multivariate normal random vector for the calculation of multidimensional integral. In addition, a proper asymptotic standard error of REML estimate is given.

• 한국전자거래학회지
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• 제17권4호
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• pp.117-140
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• 2012

본 연구는 경쟁분석을 통해 효율적인 벤치마킹 대상을 파악 후 개선점을 도출하는 컨설팅기법의 활용에 관한 연구이다. 경쟁자 분석을 위해 상대적 효율성 분석도구인 DEA(Data Envelopment Analysis, 자료포락분석)을 이용하여 컨설팅현장 또는 기업 내부에서 효율적으로 적용이 가능한 컨설팅 분석기법을 개발하여 기존 경쟁분석기법과 비교하여 제시하였다. 본 연구는 먼저 문헌고찰을 통해 컨설팅 방법론의 경쟁분석 기법과 상대적 효율성 분석 기법인 DEA에 대한 기존학자들의 연구를 살펴보고 DEA를 기반으로 한 경쟁분석인 다차원효율분석방법을 제시한 후 이 분석 방법의 적합성 및 실용성을 확인하기 위해 공기업 "A"를 대상으로 사례 연구를 실시하였다.

• 여성건강간호학회지
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• 제3권2호
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• pp.208-223
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• 1997

This study was made to suggest the nursing strategies for promoting the behaviors about bone mass health behaviors in order to prevent middle aged women's osteoporosis. This study was a descriptive-correlational design that also concerned to the types which improve bone mass promoting behaviors by inspecting patterns of health locus of control method out of recognizable variables of health improving models influencing on these bone mass promoting behaviors. For these purpose, data were collected by self reported questionnaire in middle school, from 158 women living in Seoul. The measuring tools used in this study about bone mass promoting behaviors and multidimensional health locus of control, were developed by author on the basis of literature review and analyzed by SPSS-PC window, into pearson's correlation, ANOVA, multiple regression, cluster analysis. Data was analyzed as follows. 1. 6 Multidimensional health locus of control scale clusters were existed. : a)cluster I (pure internal), b)cluster II(pure chance), c) cluster III(Believer in control), d), cluster IV(Type VI), e)cluster V(yea sayer), f) cluster VI(nay sayer). There were no findings of the powerful others external cluster and double external cluster. 2. The higher the value of internal health locus of control was, the better the bone mass promoting behaviors were(r=.2891, $p=.00^{**}$). The higher the value of chance external health locus of control was, the worse the bone mass promoting behaviors were(r=-.1367, $p=.00^{**}$). 3. On the basis of these relationships, 6 clusters were significantly different in the bone mass promoting behaviors(F=2.27, $p=.05^*$). The value of bone mass promoting behaviors was ranked the order of type VI>believer in control>pure internal>yea sayer>nay sayer>pure chance external highly. 4. Bone mass promoting behaviors were not significantly different as to age. Suggestion. Based on the results from the study, I would like to make some suggestions as follows. 1) To delay the loss of bone mass in middle aged women, the study on the cluster of the multidimensional health locus of control should be conducted repeatedly. 2) The tool of multidimensional health locus of control should be developed through a qualitative method adjusted on Korean' health culture.