• Title/Summary/Keyword: Model Validity

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A Study on Analysis of Time Delay Model Using Autoregressive Method for Mobile Communication Channels (AR 모델을 이용한 이동 통신 채널의 시간 지연 해석기법에 관한 연구)

  • 이형권;류은숙;이종길
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.29-32
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    • 1999
  • In this study, the time delay model were simulated using the well-known AR model. Frequency response of the time delay model can be obtained by mapping AR model to JTC model in the time domain. That is, from the few measurement data in JTC model, the channel frequency response can be obtained by the estimation of AR model parameters. From this channel frequency response, the time delay model can be obtained using Fourier transformation. To prove the validity of the suggested method, three models of JTC were shown and analyzed.

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Development of NCS Based Vocational Curriculum Model for the Practical and Creative Human Respirces (실전 창의형 인재 양성을 위한 NCS 기반 직업교육과정의 모형 개발)

  • Kim, Dong-Yeon;Kim, Jinsoo
    • 대한공업교육학회지
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    • v.39 no.2
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    • pp.101-121
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    • 2014
  • The study aims to develop the NCS based vocational curriculum model for the practical and creative human resources. For effectiveness of the study, the study consists of literature studies of both domestic and international, contents analysis, case study, expert(9samples) consultation and review, and in-depth-interview of the three advisory members. The validity of the developed model is analyzed through mean, standard deviation and contents validity ratio(CVR). The main results of the model development in our study are as follow. First, our NCS based vocational curriculum model for the practical and creative human resources is developed with the analyses of NCS development manuals, training standard utilization and training curriculum organization manuals, NCS learning module development manual and case studies, NCS research report, NCS based curriculum pilot development resources directed toward the high schools and vocational school as well as the domestic and international literature study on career training model like NCS. Second, based on the findings of our analysis in combination with the findings from the consultations with the expert and advisory committee, total 19 sub-factors of each step and domain are extracted. The sub-factors of domain in step 1 are the competency unit, definition of competency unit, competency unit element, performance criteria, range of variable, guide of assessment, key competency; in step 2, they are subject title, subject objectives, chapter title, chapter objectives, pedagogical methods, assessment methods and basic job competence; and in step 2, they are NCS based subject matrix table, NCS based subject profile, NCS based job training curriculum table, NCS based subjects organization flowchart, NCS based job training operation plan. Third, the final model including step 3 NCS based subject profile are developed in association with the linked organizational sub-factors of step 1 and step 2. Forth, the validity tests for the final model by the step and domain yield the mean 4.67, CVR value 1.00, indicating the superior validity. Also, the means of each sub-factors are all over 4.33 with the CVR value 1.00, indicating the high validity as well. The means of the associated organizations within the model are also over 4.33 with the CVR value of 1.00. Standard deviations are all .50 or lower which are small. Fifth, based on the validity test results and the in-depth-interview of the expert and advisory committee, the model is adjusted complemented to establish final model of the NCS based vocational curriculum for the practical and creative human resources.

Verification and Evaluation of Spatial Structure Theory through Discrete Event Simulation (이산사건 시뮬레이션을 이용한 공간구조론의 검증 및 평가)

  • Yoon, So Hee;Kim, Suk Tae
    • Journal of Korea Multimedia Society
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    • v.19 no.12
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    • pp.2000-2013
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    • 2016
  • The purpose of this study is to validate the validity of the methodology for analyzing the space with complex characteristics and to evaluate the existing spatial structure analysis theory. Seven example models are designed and analyzed data of spatial syntax analysis and visibility graph analysis. And analyzed the agent-based model using two analytical methods: the adjacent space and the whole spatial connection. The results of this study are as follows. Based on the analysis of the agent - based model for perfectly freewalking, the validity of the method is verified in terms of predictive ability and effectiveness. Agent-based models can be simulated considering various variables, so realistic predictions will be possible and a new biography of complex systems can be met.

An improved kirchhoff approximation for radar scattering from rough surfaces (거친 표면 레이다 산란 해석을 위한 개선된 Kirchhoff 근사 방법)

  • Oh, Yisok
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.1
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    • pp.45-52
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    • 1995
  • A new Kirchhoff approximation(KA) method was proposed for microwave scttering from randomly rough surfaces. Using the spectral representation of delta function and its sifting theorem, a new KA was formulated directly without any further approximation, and this formulated was used to compute exact backscttering coefficients. The validity of the KA was verified by a numerical method, and this new KA technique was used to evaluate the existing approximated KkA methods; i.t., the zeroth-order and the first-order approximated physical optics(PO) models. It was shown that the first-order approximated PO model has small error than the zeroth-order approximated PO model at low incidence angles and the opposite happens at higher incidence angles. This new KA model can be used to compute exact scattering coefficients in the validity regions of KA and to evaluate other theoretical and numerical models for scattering from randomly rough surfaces.

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A Schema Approach to Cognitive Resonance and Its Decision-making Performance

  • Lee Kun Chang;Chung Namho
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2003.05a
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    • pp.931-939
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    • 2003
  • This paper is aimed at proposing a new framework to predict decision performance, by Investigating decision maker's cognitive resonance. We assume that every decision maker has two kinds of schema­emotional schema and rational schema. Cognitive resonance is believed to have a close relationship with the two schemata and decision performance. In literature on decision performance there is no study' seeking relationship among the two schemata ana cognitive resonance. Therefore, our research purposes are twofold: (1) to provide a theoretical basis for the proposed framework describing the causal relationships among two schemata, cognitive resonance, and decision Performance, and (2) to empirically prove its validity applying to. Internet shopping Situation. Based on the questionnaires from 13S- respondents, we used a second order confirmatory factor analysis (CFA) to extract valid constructs, and structural equation model (SEM) to calculate path coefficients and prove the statistical validity of our proposed research model. Experimental results supported our research model with some further research issues.

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Washout of Tritiated Water Vapor by Precipitation in the Vicinity of Wolsong Nuclear Power Plant Site

  • Kim, C.K.;Lee, S.K.;Rho, B.H.;Park, G.J.;Kim, W.;Kang, H.D.
    • Journal of Radiation Protection and Research
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    • v.28 no.4
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    • pp.337-342
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    • 2003
  • On a basis of the washout model and concentrations of anthropogenic tritium in rainwater around the Wolsong site, the washout coefficients of tritium by rainwater were calculated, and the validity of washout deposition model are estimated. As the result of that, the washout coefficients in 10 sampling stations around Wolsong site were in the range of $2.9{\times}10^{-5}\;-\;16{\times}10^{-5}\;s^{-1}$ with the mean value of $7.21{\times}10^{-5}\;s^{-1}$. The validity of the washout deposition model was confirmed by comparing the observed data with the calculated ones.

Cracking Behavior of RC Panels under Biaxial Tension (이축인장을 받는 철근콘크리트 패널의 균열 거동)

  • 곽효경;김도연
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.599-606
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    • 2003
  • An analytical model which can simulate the post-cracking nonlinear behavior of reinforced concrete (RC) members such as bars and panels subjected to uniaxial and biaxial tensile stresses is presented. The proposed model includes the description of biaxial failure criteria and the average stress-strain relation of reinforcing steel. Based on strain distribution functions of steel and concrete after cracking, average response of an embedded reinforcement, a criterion to consider the tension-stiffening effect is proposed using the concept of average stresses and strains. The validity of the introduced model is established by comparing the analytical predictions for reinforced concrete tension members with results from experimental studies. Finally, correlation studies between analytical results and experimental data from biaxial tension test are conducted with the objective to establish the validity of the proposed models and identify the significance of various effects on the response of biaxially loaded reinforced concrete panels.

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Validity of LIGHTSCAPE As a Visualization Tool for Daylighting Performance (자연채광 성능의 가시화도구로서 LIGHTSCAPE의 유용성 평가)

  • 문기훈;김정태
    • Korean Institute of Interior Design Journal
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    • no.37
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    • pp.110-118
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    • 2003
  • Computer simulation is one of the most useful techniques to predict daylighting performance and present visual image. In architectural and interior design practice, the Lightscape is commonly used often to produce persuasive images rather than physically accurate results. Therefore, this study is to validity the Lightscape as daylighting evaluation tool, in particularly performance and realistically visualization. For the purpose, an evaluation test model (12.0m$\times$7.2m$\times$3.0m) of side lighting window with lightshelf was selected. A 1:6 scale plywood physical model was made. Under clear sky condition, illuminance of 84 Interior point were measured. Lightscape was run on a 750 MHz Pentium PC running Windows 2000 under the same sky condition. And a photography image was compared to rendering image. The physical results of interior illuminance were within 8% between the scale model and Lightscape simulation. There were no differences between the photograph image and rendering image by Lightscape in the sight. Lightscape as visualization tool for daylighting performance was validated.

Test of Validity and Reliability of the Adolescent Mental Problem Questionnaire for Korean High School Students (고등학생용 정신건강 및 문제행동 선별질문지(AMPQ)의 타당도 및 신뢰도 검증)

  • Kim, Soo-Jin;Lee, Chung-Sook;Kweon, Young-Ran;Oh, Mi-Ra;Kim, Bo-Young
    • Journal of Korean Academy of Nursing
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    • v.39 no.5
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    • pp.700-708
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    • 2009
  • Purpose: This study was done to test the validity and reliability of the Adolescent Mental Problem Questionnaire (AMPQ) for Korean high school students. Methods: The AMPQ was designed to assess adolescents', mental health status and problem behavior (Ahn, 2006). A methodological study design was used with exploratory factor analysis, Pearson's correlation coefficients, and a fitness of the modified model for validity. Also, Cronbach's alpha coefficients and alternative-form method for reliability were used. AMPQ was tested with a sample of 36,313 high school students. The participants consisted of 18,701 males and 17,612 females. Results: Seven factors were extracted through factor analysis: 'Psychiatric problems', 'Delinquency', 'Academic troubles', 'Family problems', 'Hazardous behavior', 'Harmful circumstance', 'Eating problems'. These factors explained 51.1% of the total variance. The fitness of the modified model was good ($X^2$=38,413.76, Goodness of Fit Index [GFI]=.94, Adjusted Goodness of Fit Index [AGFI]=.93, Comparative Fit Index [CFI]=.95, Root Mean Square Error of Approximation [RMSEA]=.05), and concurrent validity with Korea-Youth Self-Report [K-YSR] was .63. Cronbach's alpha coefficient of the 31 items was .85. Conclusion: The results of present study suggest that the modified AMPQ instrument may be useful for efficiently assessing mental health status and problem behavior in late adolescent, high school students.