• Title/Summary/Keyword: Model Validity

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A Study on Analyzing the Validity between the Predicted and Measured Concentrations of VOCs in the Atmosphere Using the CalTOX Model (CalTOX 모델에 의한 휘발성유기화합물의 대기 중 예측 농도와 실측 농도간의 타당성 분석에 관한 연구)

  • Kim, Ok;Lee, Minwoo;Park, Sanghyun;Park, Changyoung;Song, Youngho;Kim, Byeongbin;Choi, Jinha;Lee, Jinheon
    • Journal of Environmental Health Sciences
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    • v.46 no.5
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    • pp.576-587
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    • 2020
  • Objectives: This study calculated local residents exposures to VOCs (Volatile Organic Compounds) released into the atmosphere using the CalTOX model and carried out uncertainty analysis and sensitivity analysis. The model validity was analyzed by comparing the predicted and the actual atmospheric concentrations. Methods: Uncertainty was parsed by conducting a Monte Carlo simulation. Sensitivity was dissected with the regression (coefficients) method. The model validity was analyzed by applying r2 (coefficient of determination), RMSE (root mean square error), and the Nash-Sutcliffe EI (efficiency index) formula. Results: Among the concentrations in the atmosphere in this study, benzene was the highest and the lifetime average daily dose of benzene and the average daily dose of xylene were high. In terms of the sensitivity analysis outcome, the source term to air, exposure time, indoors resting (ETri), exposure time, outdoors at home (ETao), yearly average wind speed (v_w), contaminated area in ㎡ (Area), active breathing rate (BRa), resting breathing rate (BRr), exposure time, and active indoors (ETai) were elicited as input variables having great influence upon this model. In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. To supplement this value, the regression formula was derived for benzene with y=0.002+15.48x, ethylbenzene with y ≡ 0.001+57.240x, styrene with y=0.000+42.249x, toluene with y=0.004+91.588x, and xylene with y=0.000+0.007x. Conclusions: In consequence of inspecting the validity of the model, r2 appeared to be a value close to 1 and RMSE appeared to be a value close to 0, but EI indicated unacceptable model efficiency. This will be able to be used as base data for securing the accuracy and reliability of the model.

Scale Development for Youth Obesity Prevention and Unified Validity Test through the Health Belief Model-I (건강신념모형을 적용한 청소년 비만예방척도개발과 통합적 타당도검증-I)

  • Kim, Eung-Joon;Ko, Byoung-Goo;Cho, Eun-Hyung
    • 한국체육학회지인문사회과학편
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    • v.58 no.1
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    • pp.295-308
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    • 2019
  • The purpose of the present study is to apply a health belief model to the serious perception of an increase in youth obesity, and to develop and validate a measurement tool for youth obesity prevention among this group who are experiencing increasing rates of obesity. The specific goals of this study are to 1) apply a health belief model to develop a measurement tool for obesity prevention among youth who are seeing rising rates of obesity, and 2) provide an integrated validation procedure and foundation for developing this measurement tool. A total of 1801 high school students[sample1: 902(male:464,female:438); sample2: 899(male:464,female:438)] were recruited and collected data from 12 high school in Seoul and Kyonggi area. For this study the analytic framework of unified validity was developed which can comprehensively reflect unified validity be Messick(1995), framework for conducting a strong program of construct validation by Benson(1998), the unified validity implementation method of Rasch model suggested by Wolfe and Smith(2007a, 2007b). Furthermore, after dividing the developed analytic framework into each stage(the substantive domain), the evidence of validity of Youth Obesity Prevention Scale(YOPS) applying Health Belief Model was systematically suggested. The YOPS suggested the evidence about the substantive domain of unified validity. The developed YOPS was consist of Susceptibility, Severity, Benefits, Barriers and Cues to Action. After 3 stage in substantive domain, the components of YOPS(5factors and 28items) satisfied the unidimensionality, and the 5 point Likert scale had the significant discrimination of the respondents' response.

A Study on Developing a Model for Evaluating the Validity of New School Construction (학교(學校) 신축(新築) 타당성(妥當性) 평가(評價) 모형(模型) 개발(開發)에 관한 연구(硏究))

  • Lee, Hwa-Ryong
    • Journal of the Korean Institute of Educational Facilities
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    • v.12 no.5
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    • pp.47-56
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    • 2005
  • Reports on population movement(2000-2030) by the National Statistical Office show that the number of elementary school age population will be decreased by 1.4million from 2005 to 2020. It will effect both school size and the policies for school facilities, which have focused on downsizing class as the high standard of OECD nations. As the unfolding evidence is emerging that a number of schools and classes will be emptied out by 2030. This study aims at developing a model for evaluating the validity of school establishment, which would help more reasonable decision-making for new school construction and the class extension in the existing schools. It classifies two different ways in founding a new school - school establishment in a residential developing site and school establishment for solving a overcrowd class. It proposes the assesment items and the methods for evaluating its validity. In the end, it suggests an assesment model which the district educational offices can use in the course of planning the student accomodations to schools and making decisions for new school construction and the class extension in the existing schools. This study would be expected to help the reasonable expenditure for school facilities and to restrict overbuilding of surplus classes.

Comparison of Three Optimization Methods Using Korean Population Data

  • Oh, Deok-Kyo
    • Korean System Dynamics Review
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    • v.13 no.2
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    • pp.47-71
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    • 2012
  • The purpose of this research is the examination of validity of data as well as simulation model, i.e. to simulate the real data in the SD model with the least error using the adjustments for the faithful reflection of real data to the simulation. In general, SD programs (e.g. VENSIM) utilize the Euler or Runge-Kutta method as an algorithm. It is possible to reflect the trend of real data via these two estimation methods however can cause the validity problem in case of the simulation requiring the accuracy as they have endogenous errors. In this article, the future population estimated by the Korea National Statistical Office (KNSO) to 2050 is simulated by the aging chain model, dividing the population into three cohorts, 0-14, 15-64, 65 and over cohorts by age and offering the adjustments to them. Adjustments are calculated by optimization with three different methods, optimization in EXCEL, manual optimization with iterative calculation, and optimization in VENSIM DSS, the results are compared, and at last the optimal adjustment set with the least error are found among them. The simulation results with the pre-determined optimal adjustment set are validated by methods proposed by Barlas (1996) and other alternative methods. It is concluded that the result of simulation model in this research has no significant difference from the real data and reflects the real trend faithfully.

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Validity, Reliability and Reproducibility of Space Analysis using Digital Model taken via Model Scanner and Intraoral Scanner: An In vivo Study (모델 스캐너와 구내 스캐너로 획득한 디지털 모형에서 시행한 공간 분석의 타당도, 신뢰도, 재현성 평가)

  • Park, Seohyun;Kim, Jongsoo;Oh, Sohee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.47 no.2
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    • pp.176-187
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    • 2020
  • The purpose of this study is to evaluate validity, reliability and reproducibility of tooth width (TW), arch length (AL) and arch length discrepancy (ALD) measured on a digital model taken via 3-dimensional model scanner and intraoral scanner compared to a plaster model. A total of 30 patients aged 12 to 18 were eligible for the study. 3 types of models were acquired from each patient: a conventional plaster model (P), a model scanned digital model (MSD) taken via Freedom UHD® and an intraoral scanned digital model (ISD) taken via CS3600® in-vivo. The reliability of TW and AL in each group was evaluated using Pearson's correlation coefficient, while the reproducibility was evaluated with intraclass correlation coefficient. The validity of space analysis was assessed by paired t-test. As a result, all measurements of P, MSD and ISD groups showed favorable reliability and reproducibility. Most of measurements for space analysis in MSD group and TW in ISD group also presented high validity. AL and ALD presented statistically significant difference between P and ISD group. The validity of measurements of space analysis in ISD group was short in doubt to valid, but clinically acceptable. Both MSD and ISD are clinically acceptable to use for space analysis but clinician should be aware that errors can be found using a digital model.

Psychometric Properties of the Alzheimer's Disease Knowledge Scale-Korean Version (한국어판 알츠하이머병 지식 측정도구의 신뢰도와 타당도)

  • Kim, Eun Joo;Jung, Ji-Young
    • Journal of Korean Academy of Nursing
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    • v.45 no.1
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    • pp.107-117
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    • 2015
  • Purpose: The purpose of this study was to evaluate the psychometric properties of the Korean version of the Alzheimer's Disease Knowledge Scale (ADKS-K) to determine its applicability to Korean adults. Methods: Cross-cultural validity was performed according to Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). The Kuder-Richardson Formula 20 for internal consistency and Intraclass Correlation Coefficient (ICC) for test-retest reliability were conducted. Content validity, criterion related validity and construct validity were evaluated. The Classical Test Theory (CTT) model and the Item Response Theory (IRT) model were applied in performing the item analysis. Results: The KR 20 was .71, and the ICC was .90, indicating that the ADKS-K has internal consistency and stability reliability. Thirty items of the ADKS-K had significant Content Validity Ratio (CVR) values, i.e., mean of 0.82 and range of 0.60~1.00. Mean item difficulty and discrimination indices calculated by TestAn program were 0.63 and 0.23, respectively. Mean item difficulty and discrimination indices calculated by BayesiAn program were -0.60 and 0.77, respectively. These tests indicate that ADKS-K has an acceptable level of difficulty and discriminating efficiency. Conclusion: Results suggest that ADKS-K has the potential to be a proper instrument for assessing AD knowledge in Korean adults.

A Preliminary Study on Validity of Korean Behavior Rating Inventory of Executive Function-Preschool Version(BRIEF-P) (한국판 유아용 실행기능 척도(BRIEF-P)의 타당화를 위한 예비연구)

  • KOWN, Yeon-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.2
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    • pp.436-446
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    • 2017
  • This study was performed to verify the validity and utility of the Korean Behavior Rating Inventory of Executive Function-Preschool Version(BRIEF-P). The BRIEF-P is one of the most used instruments to measure Executive Function(EF) and a teacher-rating assessment method designed to measure the executive function of preschoolers(age 2-5). A total of 200 preschoolers(104 boys, 96 girls; recruited aged 3 to 5years) participated. Confirmatory factor analysis was carried out to evaluate the model structure. Correlation analysis was done to verify the concurrent validity. In the results, the model fit indexes were good with the five BRIEF-P subscales (that is, inhibit, shift, emotional control, working memory, plan/organize). The internal consistency of the BRIEF-P five subscales were supported. As a results, the Korean Behavior Rating Inventory of Executive Function-Preschool Version(BRIEF-P) was confirmed to be a reliable and valid assessment tool to measure executive function in preschoolers.

An Evaluation Model for the Major Science Research Facilities and Equipments to Enhance the Competitiveness of the Science and Technology: A Focus on the Test of Reliability and Validity of the Model (과학기술 경쟁력 제고를 위한 대형연구시설 및 장비 평가모형 분석 : 모형의 신뢰성 및 타당성 검토를 중심으로)

  • Kwon, Gi-Heon;Cha, Yong-Jin;Lee, Hong-Jae
    • Journal of Korea Technology Innovation Society
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    • v.10 no.1
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    • pp.121-142
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    • 2007
  • The purpose of this study is to construct the evaluation model for the major science research facilities and equipments to enhance the competitiveness of the science and technology and also to test the reliability and validity of the model. To achieve the purposes, this study theoretically reviews the concept of the major science research facilities and equipments and their characteristics. Through a review of literature, this study draws 11 criteria for evaluating the priorities of the major science research facilities and equipments. These criteria are categorized as two dimensions - 'science & technology' and 'national policy'. The dimension of science & technology includes scientific importance, technological readiness, utilization rate, common utilization rate, and ability of management and operation. The national policy dimension contains degree of correspondence with national science development, imperativeness of national policy, science and technical effectiveness, economic and industrial effectiveness, responsiveness of research demand, and equity among the related institutions. The competitiveness of the science and technology consists of these two dimensions. The evaluation model is established on the framework of criteria. The 18 major science research facilities and equipments are selected through a series of Delphi. The survey of experts (BT, ET, IT, NT and ST) is also implemented to evaluate the 18 major science research facilities and equipments by 11 criteria. The overall results indicate that the reliability and validity of the model are good. The reliability tests show that the five indicators of science & technology and the six indicators of national policy have high internal consistencies. The confirmatory factor analyses reveal that the two constructs - 'science & technology' and 'national policy' - have high convergent and discriminant validity. The correlational analyses also show that the criteria-related validity between them is high. Furthermore, the results of higher order factor analysis indicate that the fit indices of the model are high and suggest a good fit to the data. Based on these findings, the policy implications of the model are discussed.

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A Technology-based New Business Planning Model ; Fuzzy Inference Systems Approach (신규사업의 성공판정을 위한 퍼지추론모형)

  • 권철신;김태현
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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    • pp.246-249
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    • 2001
  • In this study we propose a technology selection model, which captures technology seeds for new business area by a fuzzy structural modeling method and then, design a model, which evaluates the validity of New Business Development plans for the selected technology seeds with regard to the properties of manufacturing, product, market, and economy as well. Finally, a fuzzy inference system is designed in order to decide the degree of success of New Business Development plans based on the preceding validity evaluation.

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Reliability and Validity of the Korean Version of the Cancer Stigma Scale

  • So, Hyang Sook;Chae, Myeong Jeong;Kim, Hye Young
    • Journal of Korean Academy of Nursing
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    • v.47 no.1
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    • pp.121-132
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    • 2017
  • Purpose: In this study the reliability and validity of the Korean version of the Cancer Stigma Scale (KCSS) was evaluated. Methods: The KCSS was formed through translation and modification of Cataldo Lung Cancer Stigma Scale. The KCSS, Psychological Symptom Inventory (PSI), and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (EORTC QLQ-C30) were administered to 247 men and women diagnosed with one of the five major cancers. Construct validity, item convergent and discriminant validity, concurrent validity, known-group validity, and internal consistency reliability of the KCSS were evaluated. Results: Exploratory factor analysis supported the construct validity with a six-factor solution; that explained 65.7% of the total variance. The six-factor model was validated by confirmatory factor analysis (Q (${\chi}^2/df$)= 2.28, GFI=.84, AGFI=.81, NFI=.80, TLI=.86, RMR=.03, and RMSEA=.07). Concurrent validity was demonstrated with the QLQ-C30 (global: r=-.44; functional: r=-.19; symptom: r=.42). The KCSS had known-group validity. Cronbach's alpha coefficient for the 24 items was .89. Conclusion: The results of this study suggest that the 24-item KCSS has relatively acceptable reliability and validity and can be used in clinical research to assess cancer stigma and its impacts on health-related quality of life in Korean cancer patients.