• Title/Summary/Keyword: Model fit

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Development of Multiple Transient Storage Model Using Particle Tracking Method (입자추적방법을 이용한 다중저장대모형 개발)

  • Cheong, Tae-Sung;Seo, Il-Won
    • Journal of Korea Water Resources Association
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    • v.37 no.4
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    • pp.257-271
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    • 2004
  • To evaluate behavior in representing solute transport in natural streams, the storage zone model of the axially periodic transient storage zones is developed. The periodic transient storage zone model and continuous storage zone model are verified using the parameters and the tracer concentration vs. time curves observed in laboratory channels. The periodic storage zone model best fit the measured concentration vs. time curves, while the continuous storage model fails to describe some fluctuations and the plateau region of the tail occurring in a discontinuous transient storage system. Dispersion data from Shingobee River, Minnesota, U. S. A. show that the concentration curves simulated by the proposed model fit the observed concentration curves well.

A Predictive Model Comparison by Sex for Alcohol Consumption Behavior among Korea University Students (한국 대학생의 음주행위 예측모형의 성별 비교분석)

  • 최명숙;임미영;윤영미
    • Journal of Korean Academy of Nursing
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    • v.32 no.1
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    • pp.77-88
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    • 2002
  • The purpose of this study was designed to develope and test the structural model that explains alcohol consumption behaviors among university students in Republic of Korea. The hypothetical model was constructed on the basis of the literature review and Pender's Health promotion model. Data was collected from questionnaires from 512 university students in Republic of Korea, from August to September, 2000. The reliability of instruments was adequate (Cronbach's alpha= .69-.90). Data analysis was done with SAS 6.12 for descriptive statistics and LISREL 8.13 program for covariance structural analysis. The results are as follows; 1. The overall fit of the hypothetical model to the data was moderate. Thus it was modified by male and female models. 2. The revised model has become parsimonious and had a better fit to the empirical data (male: χ2=87.21 p=.00, GFI=.97, AGFI= .94, NFI=.99, NNFI=1.0, CN=619.17, female: χ2=49.29 p=.31, GFI=.45, AGFI= .95, NFI=.99, NNFI=1.0, CN=370.02). 3. Self-efficacy was most significant factor and personality of novelty seeking, reward compensation, alcohol expectancy and drinking attitude have significant effects on male alcohol consumption behavior. 4. Personality of novelty seeking was most significant factor and personality of harm avoidance, friend influence, self-efficacies, alcohol expectancy and drinking attitude have significant effects on female alcohol consumption behavior.

The Effect of VMD Structural Elements on Fashion Brand Attitude (VMO 구성요소의 패션 브랜드 태도효과에 관한 연구)

  • 박현희;전중옥
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.2
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    • pp.224-234
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    • 2004
  • This paper is an exploratory research to identify the structural model suitable for the fashion brand attitude effect process of VMD structural elements. Under the circumstances of severe competitiveness in price-conscious casual brand, we intended to find measurement model of VMD effect to establish plausible brand specific VMD strategy. Since VMD is regarded as one of marketing stimuli like advertising, we introduced Mackenzie, Lutz, and Belch(1986)'s advertising effect measurement model for the analysis. For the study, VMD structural elements were composed of controllable visual factors from store environment at the aspect of marketing strategy. As a result, the reciprocal mediation hypothesis model shows the best fit for the VMD stimuli. That is, under the cognition of interaction between VMD attitude and brand attitude, strategy must be considered to strengthen the attitude relation between VMD and brand. The second fit model was the dual mediation model which was adopted from Petty and Cacioppo's ELM. According to this, when you make use of VMD strategy, it is needed to consider both of affective and cognitive factors of VMD.

Measuring the Causal Relationships between Past Consumption,Health Belief, Subjective Norm, Attitude, Intention and Behaviorand Purchase of Organic Foods (과거 소비, 건강 신념, 주관적 규범, 태도, 의도와 유기농 음식 구매 행동의 인과관계 평가)

  • Kang, Jong-Heon;Lee, Jae-Gon
    • Culinary science and hospitality research
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    • v.14 no.2
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    • pp.170-180
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    • 2008
  • The purpose of this study was to measure the causal relationships between past consumption, health belief, subjective, attitude, intention and purchase of organic foods. Total 326 copies of questionnaire were completed. The structural equation model was used to measure the causal effect among constructs. The results demonstrated that the confirmatory factor analysis model provided a good model fit. The proposed model yielded a significantly better fit to the data than the baseline model and the extended model. The effects of past consumption, health belief and subjective norm on attitude and intention were statistically significant. The effects of attitude on intention and behavior to purchase organic food were statistically significant. As expected, health belief and subjective had significant effects on behavior to purchase organic foods. Moreover, past consumption, health belief and subjective norm had indirect influences on intention through mediated variables. Based on the empirical results and findings, some suggestions are provided to the institutions concerned so as to facilitate this organic sector's on-going expansion in the food industry.

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A Machine Learning Univariate Time series Model for Forecasting COVID-19 Confirmed Cases: A Pilot Study in Botswana

  • Mphale, Ofaletse;Okike, Ezekiel U;Rafifing, Neo
    • International Journal of Computer Science & Network Security
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    • v.22 no.1
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    • pp.225-233
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    • 2022
  • The recent outbreak of corona virus (COVID-19) infectious disease had made its forecasting critical cornerstones in most scientific studies. This study adopts a machine learning based time series model - Auto Regressive Integrated Moving Average (ARIMA) model to forecast COVID-19 confirmed cases in Botswana over 60 days period. Findings of the study show that COVID-19 confirmed cases in Botswana are steadily rising in a steep upward trend with random fluctuations. This trend can also be described effectively using an additive model when scrutinized in Seasonal Trend Decomposition method by Loess. In selecting the best fit ARIMA model, a Grid Search Algorithm was developed with python language and was used to optimize an Akaike Information Criterion (AIC) metric. The best fit ARIMA model was determined at ARIMA (5, 1, 1), which depicted the least AIC score of 3885.091. Results of the study proved that ARIMA model can be useful in generating reliable and volatile forecasts that can used to guide on understanding of the future spread of infectious diseases or pandemics. Most significantly, findings of the study are expected to raise social awareness to disease monitoring institutions and government regulatory bodies where it can be used to support strategic health decisions and initiate policy improvement for better management of the COVID-19 pandemic.

Comparison of the marginal and internal fit of cores fabricated by Ni-Cr alloy(non-beryllium) and Co-Cr alloy (베릴륨이 함유되지 않은 니켈-크롬 합금 코어와 코발트-크롬 합금 코어의 적합도 비교평가)

  • Kim, Ki-Baek;Kim, Jae-Hong;Kim, Woong-Chul;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.34 no.4
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    • pp.353-359
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    • 2012
  • Purpose: The aim of this study measured and compared the marginal and internal fit of metal cores with two base metal alloy (Ni-Cr alloy(non-beryllium), Co-Cr alloy). Methods: Maxillary right first molar abutment fabricated by titanium was prepared for this study. Impressions(10ea) were made from titanium model, and study models were poured with improved dental stone. Wax cores of twenty were prepared for burn-out and casting. Ten wax cores cast Ni-Cr alloy(non-Be), and finally ten cast Co-Cr alloy. Marginal and internal fit of cores was evaluated using silicone replica technique and digital microscope(x160). The data were statistically analyzed with the independent samples t-test (${\alpha}$ <.05). Results: Mean(standard deviation, SD) marginal and internal fit total size of Ni-Cr alloy(non-Be) group was $73.3(14.4){\mu}m$ and of Co-Cr alloy group $65.6(17.4){\mu}m$. The marginal and internal fit total size of Ni-Cr alloy group(non-Be) was statistically significantly greater than that of Co-Cr alloy group (P=.004). Conclusion: Co-Cr alloy cores in this study had a better marginal fit than Ni-Cr alloy(non-Be) cores.

Lower Body Analyses and Pattern Development of Slim-fit Jeans for Upper Grade Elementary School Girls (학령 후기 여아의 하반신 체형 분석과 슬림핏 청바지 패턴 개발)

  • Kim, Hea Suk;Lee, Jeong Yim
    • Fashion & Textile Research Journal
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    • v.23 no.4
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    • pp.491-503
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    • 2021
  • The purpose of this study is to develop a slim-fit jeans pattern that is suitable for the lower body of upper grade elementary school girls, who are beginning to show gender differences in body shape. Four age groups of two years each were considered for girls 7 to 14 years old. The mean and standard deviation of body measurements were calculated for each age group to analyze body shape variation, and hence the body characteristics of upper grade elementary school girls were identified. The high-frequency measurements of stature-waist circumference and waist circumference-hip circumference combinations were analyzed. In order to determine the size of each part of the jeans pattern and derive the drafting formula, the pattern sizes of brand A jeans, which had received a high score in the evaluation for ready-to-wear jeans(Kim & Lee, 2020), were used as the base criteria. In addition, the body sizes observed and calculated in the study were applied. Additionally, the requirements for better fit of ready-to-wear jeans, found in the survey on jeans wearing conditions and size dissatisfaction(Kim & Lee, 2019), were taken into consideration. Based on this research, a model set of jeans was prepared with the pattern developed and its fit evaluation was conducted. Thus, a slim-fit jeans pattern suitable for the lower body of upper grade elementary school girls was finalized. The pattern proposed in this study has excellent appearance and motion functionality, and is expected to contribute to reduce the fit dissatisfaction.

Effect of cement space on marginal and internal fit of a zirconia core fabricated using by additive manufacturing (시멘트 공간이 적층 가공으로 제작한 지르코니아 하부구조물의 변연 및 내면 적합도에 미치는 영향)

  • Ji-Won Min;Se-Yeon Kim;Jae-Hong Kim
    • Journal of Technologic Dentistry
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    • v.46 no.1
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    • pp.1-7
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    • 2024
  • Purpose: The goal of this study was to determine the clinical acceptability of various cement space settings for the marginal and internal fit of a zirconia core manufactured using additive manufacturing. Methods: The maxillary right incisor served as the master model. After scanning the maxillary right incisor with a dental 3D (three-dimensional) scanner, the stereo lithography file was created using different cement space settings of 40, 120, and 200 ㎛ using computer-aided design software (Dental System 2018; 3Shape). The marginal and internal fit of the 3 groups were determined using the silicon replica technique. Measurement points were divided into the following three categories: margin, axial wall, and incisal. To ensure more accurate measurements, these three measurement points were divided into 8 points. The Shapiro-Wilk, one-way ANOVA, and Tukey's honestly significant difference test (for all tests α=0.05) were the statistical analyses that were included in the study. Results: The CS (cement space)-200 group had better marginal and internal fit than the CS-40 and CS-120 groups, and there were statistically significant differences at the marginal and incisal points, except for the axial wall points. CS-200 group, both marginal and internal fit were within 120 ㎛, which is the clinically acceptable value. Conclusion: This study suggests that a 200 ㎛ cement space setting is ideal for optimal marginal and internal fit of 3D-printed ceramic crowns.

Combining Regression Model and Time Series Model to a Set of Autocorrelated Data

  • Jee, Man-Won
    • Journal of the military operations research society of Korea
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    • v.8 no.1
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    • pp.71-76
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    • 1982
  • A procedure is established for combining a regression model and a time series model to fit to a set of autocorrelated data. This procedure is based on an iterative method to compute regression parameter estimates and time series parameter estimates simultaneously. The time series model which is discussed is basically AR(p) model, since MA(q) model or ARMA(p,q) model can be inverted to AR({$\infty$) model which can be approximated by AR(p) model. The procedure discussed in this articled is applied in general to any combination of regression model and time series model.

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