• Title/Summary/Keyword: Model adequacy

Search Result 365, Processing Time 0.029 seconds

Censored varying coefficient regression model using Buckley-James method

  • Shim, Jooyong;Seok, Kyungha
    • Journal of the Korean Data and Information Science Society
    • /
    • v.28 no.5
    • /
    • pp.1167-1177
    • /
    • 2017
  • The censored regression using the pseudo-response variable proposed by Buckley and James has been one of the most well-known models. Recently, the varying coefficient regression model has received a great deal of attention as an important tool for modeling. In this paper we propose a censored varying coefficient regression model using Buckley-James method to consider situations where the regression coefficients of the model are not constant but change as the smoothing variables change. By using the formulation of least squares support vector machine (LS-SVM), the coefficient estimators of the proposed model can be easily obtained from simple linear equations. Furthermore, a generalized cross validation function can be easily derived. In this paper, we evaluated the proposed method and demonstrated the adequacy through simulate data sets and real data sets.

A Study on the Reasonable Rebate Level by Diffusion Characteristics and Avoided Cost Analyses of High Efficient Pumps (보급특성 및 회피비용 분석을 통한 고효율펌프의 적정 장려금 산정 방안 연구)

  • Hwang, Sung-Wook;Won, Jong-Ryul;Lee, Byung-Ha;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
    • /
    • 2008.04b
    • /
    • pp.3-5
    • /
    • 2008
  • In this paper, a modified diffusion model integrated with the effects of rebate programs is developed. The greater part of motors is included to various systems such as pump systems, fan systems, ventilation systems, motor itself, and so on. Hence, the existing rebate program is not suitable for these systems and a generalized rebate model for these systems is necessary. In the pre-study, a new diffusion model for motor rebate Program was proposed and the adequacy of this model was evaluated in the case of Korea. This paper shows that the motor rebate model could be applied to the case of pumps.

  • PDF

Marital Quality and Stability : A Theoretical Model (결혼생활의 질과 안정성 : 이론적 모델의 검증)

  • Kim, Yeong-Hee
    • Journal of the Korean Home Economics Association
    • /
    • v.37 no.6
    • /
    • pp.77-96
    • /
    • 1999
  • The purpose of this study was to examine the effect of family-of-origin, personal and spousal characteristics, mediated by communication and problem-solving behavior, on marital quality and stability. On the basis of previous literature, the theoretical model was specified, estimated, and evaluated for adequacy of statistical fit for samples of 214 married women. Although the initial model was not supported by data, the revised model fitted the data adequately. Results of structural equation modeling indicated family-of-origin and communication behavior directly affected marital quality. However, the personal and spousal characteristics were linked with marital quality and stability only if they were mediated by communication and problemsolving behavior. Communication behavior was strongly related to marital quality and stability both directly and indirectly through problem-solving behavior. The model also showed marital quality can be an antecedent variable for marital stability. The findings of results is to generate more broad-minded thinking about how communication behavior, marital quality, and marital stability are interrelated.

  • PDF

Modeling Heterogeneous Wall Nucleation in Flashing Flow of Initially Subcooled Water

  • Park, Jong-Woon
    • Proceedings of the Korean Nuclear Society Conference
    • /
    • 1996.05b
    • /
    • pp.241-246
    • /
    • 1996
  • An analytical model to calculate rate of vapor generation due to heterogeneous wall nucleation in flashing flow is developed. In the present model, an important parameter of the vapor generation term, i.e. nucleation site density is calculated by integrating its probability distribution function with respect to active cavity radius. The limits of integration are minimum and maximum active cavity radii, and these are formulated using an active cavity model for nucleate boiling. This formulation, therefore. can statistically account for the effect of surface specific thermo-physical and geometric conditions on the vapor generation rate and flashing inception. For verifying the adequacy of the present model, steady state two-fluid and the bubble transport equations are solved with applicable constitutive equations. The applicable region of the bubble transport equation is also extended to churn-turbulent flow regime to predict interfacial area concentration at high void fraction. Predicted results in terms of axial pressure and void fraction profiles along the channels are compared with experimental data of Super Moby Dick and BNL Reasonable agreements have been achieved and this shows the applicability of the present model to flashing flow analysis.

  • PDF

Simulation model of 7 Phase Brushless AC Motor Using Mixed Modeling Technique Based on Circuit and Equations (회로 및 수식 기반의 혼합 모델링 기법을 이용한 7상 영구자석 브러시리스 교류전동기의 시뮬레이션 모델)

  • Mok, Hyung-Soo;Kim, Sang-Hoon
    • Journal of Industrial Technology
    • /
    • v.27 no.A
    • /
    • pp.149-155
    • /
    • 2007
  • The counter emf(electromotive forces) of a permanent magnet multi-phase brushless motor is generally a non-sinusoidal wave or a non-ideal trapezoid. So, conventional modeling using a sinusoidal wave or an ideal trapezoid counter emf can result in errors. In order to reduce modeling errors for simulation and analysis the properties of a multi-phase brushless AC motor, this paper proposes a phase variable model that is a mixed modeling technique using both Finite Element Analysis(FEA) based circuits and motor voltage equations. The phase model parameters including the counter emf voltage waveform are obtained by using of FEA, and the mixed modeling technique based on circuits and equations is used to implement a simulation model for multi-phase brushless AC motors with any counter emf voltage waveforms. Adequacy of the proposed model is established from the simulation and experimental results for a seven-phase brushless motor.

  • PDF

From Opposition to Cooperation: Semantic Change of with

  • Rhee, Seongha
    • Korean Journal of English Language and Linguistics
    • /
    • v.4 no.2
    • /
    • pp.151-174
    • /
    • 2004
  • A historical investigation reveals that English preposition with underwent a change from OPPOSITION to ASSOCIATION and further to ACCOMPANIMENT, where the first stage shows peculiarity in that the two concepts involved comprise an unusual set to form an extensional chain. Intrigued by this oddity, this paper aims to investigate the semantic structure of English preposition with from a grammaticalization perspective. We review mechanisms and models of semantic change and evaluate their adequacy with the semantic structure and change shown by with. Drawing upon the observed fact that with underwent the apparent antonymic semantic change, it is argued that such semantic change mechanisms as metaphor, metonymy, subjectification, and generalization have difficulties explaining the change, and that only the Frame-of-Focus Variation can effectively account for this peculiar change type. In terms of semantic change models, we argue that the Bleaching Model cannot effectively provide an explanation; that the Loss and Gain Model has problems in explaining the motivation of change directions; that the Metonymic-Metaphoric Model cannot be assessed at the current level of investigation; and that the Overlap Model and the Prototype Extension Model excellently account for the macro-level changes.

  • PDF

Theoretical evaluation of Cox's interaction model of client health behavior for health promotion in adult women

  • Kim, Youlim;Lee, Hyeonkyeong;Ryu, Gi Wook
    • Women's Health Nursing
    • /
    • v.26 no.2
    • /
    • pp.120-130
    • /
    • 2020
  • This study aimed to evaluate Cox's interaction model of client health behavior (IMCHB) as used in studies on women's health. Using keyword combinations of "women" and "IMCHB" or "interaction model of client health behavior," we searched the PubMed, MEDLINE, Embase, and RISS databases for studies on the promotion of women's health published from January 2009 to April 2019. Finally, 11 studies were selected and evaluated according to seven criteria for theory evaluation, which combined Fawcett's theory evaluation criteria and Chinn and Kramer's criteria. We found that the IMCHB corresponds to a verifiable practical level of a middle-range theory, although it may be partially abstract. It contains all four concepts of the metaparadigm of nursing, in terms of a holistic philosophical approach. A theoretical evaluation demonstrated that the IMCHB has significance, generality, testability, empirical adequacy, and pragmatic adequacy for nursing practice and research. However, the lack of clear conceptual definitions and the presence of complex relationships among concepts resulted in a lack of internal consistency and parsimony. According to an in-depth verification through a review of the literature, the IMCHB has been used as a health promotion intervention strategy for various populations of women and has led to useful results in nursing practice. The IMCHB was confirmed to be a suitable theory for experimental and clinical research. Future research can build on this middle-range theory for women's health research and practice.

Assessment of Acupuncture and Moxibustion Medicine Clinical Practice Using the Objective Structured Clinical Examination

  • Cho, Eunbyul;Lee, Ju-Hyun;Kwon, O Sang;Hong, Jiseong;Cho, Nam Geun
    • Journal of Acupuncture Research
    • /
    • v.38 no.3
    • /
    • pp.219-226
    • /
    • 2021
  • Background: The objective structured clinical examination (OSCE) is a widely used method to assess the clinical performance of students in clinical practice. Although OSCE has been used for undergraduate students of Korean medicine, this has not been widely reported. Methods: In 2020, the practical course for acupuncture and moxibustion medicine (acupuncture, electroacupuncture, pharmacopuncture, auricular acupuncture, and burning acupuncture) was taught using flipped learning, according to clinical practice guidelines, and assessed by the OSCE. The appropriateness of this model of education and its evaluation using OSCE were evaluated using a 5-point Likert scale, and the results were analyzed. Results: Of the respondents, 67% reported that the OSCE accurately reflected their competency, and 82% reported that online video lectures helped them to improve their clinical skills. The average adequacy score of the model was > 3.7/5, and the average adequacy score of the checklist used in the OSCE was > 4.1/5 for all 5 clinical application skills. The difference in the mean self-efficacy score between students who had taken the OSCE and those students who had not taken the OSCE, was highest in the burning acupuncture group (0.923). Conclusion: This study showed that students' satisfaction with the OSCE was high and flipped learning was an effective education model. In the future, models representing the human body or simulated patients should be used to evaluate students' skills and attitude.

Dietary quality of lunches in senior leisure service facilities in South Korea: analysis of data from the 2013-2017 Korea National Health and Nutrition Examination Survey

  • Choi, Daeun;Lee, Youngmi;Park, Haeryun;Song, Kyunghee;Hwang, Jinah
    • Nutrition Research and Practice
    • /
    • v.15 no.2
    • /
    • pp.266-277
    • /
    • 2021
  • BACKGROUND/OBJECTIVES: This study analyzed the quality of lunches provided in senior leisure service (SLS) facilities and compared institutional foodservice (IF) and non-institutional foodservice (non-IF). SUBJECTS/METHODS: Data of 390 adults aged 65 years or older who ate lunches in SLS facilities were analyzed using the information from the 2013-2017 Korea National Health and Nutrition Examination Survey. The participants were classified into IF (n = 129) and non-IF (n = 261) groups according to meal type provided. The intake of major food groups, energy and nutrients, and nutrient adequacy ratio (NAR) and mean adequacy ratio (MAR) were analyzed. The diversity of meals was evaluated by food group patterns, dietary diversity score (DDS) and dietary variety score (DVS). Energy intake was adjusted in model 1, while energy and sex were adjusted in model 2. All confounding variables were adjusted in model 3. RESULTS: The intake of seafoods (P < 0.001 in models 1, 2, and 3), seaweeds (P < 0.01 in models 1 and 2), and dairy products (P < 0.05 in models 1, 2, and 3) was significantly higher in the IF group. No significant difference existed in energy intake; however, the intake of all nutrients except carbohydrate and vitamin C was significantly higher in the IF group. NAR of all nutrients, excluding vitamin C, was higher in the IF group, and MAR was also higher in the IF group (P < 0.001 in models 1, 2, and 3). The IF group had significantly higher DDS and DVS than the non-IF group (P < 0.001). CONCLUSIONS: The lunches provided in SLS facilities were better in terms of quantity and quality when provided through IF than through non-IF. More systematic foodservice programs should be implemented in SLS facilities, especially in facilities wherein users prepare their own meals.

A Study on Design for Anchorage Zone in PSC Box Girder Bridge Using Strut-Tie Model (스트럿-타이 모델을 이용한 PSC 박스거더교량의 정착부 설계 연구)

  • 이주하;윤영수;이만섭;김병석
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2002.10a
    • /
    • pp.625-630
    • /
    • 2002
  • PSC box girder is widely used in a domestic bridge and overpass, etc., therefore, the design and construction technique for the PSC box girder is developing day by day. Even if it were so, however, the design for anchorage zone in PSC box girder has depended on common sense and empirical results. And it is the current situation that the designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of anchorage zone. Besides, the design based on Leonhardt's method is being done in general, but the design may be various even for the same structure because of the difference in a way of applying. In this paper, therefore, anchorage zone in PSC box girder bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice, and this study presents that strut-tie model can be a rational and an economical design than current design methods.

  • PDF