• Title/Summary/Keyword: Model Fitness

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Estimation of Stem Taper Equations and Stem Volume Table for Phyllostachys pubescens Mazel in South Korea (맹종죽의 수간곡선식 및 수간재적표 추정)

  • Eun-Ji, Bae;Yeong-Mo, Son;Jin-Taek, Kang
    • Journal of Korean Society of Forest Science
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    • v.111 no.4
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    • pp.622-629
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    • 2022
  • The study aim was to derive a stem taper equation for Phyllostachys pubescens, a type of bamboo in South Korea, and to develop a stem volume table. To derive the stem taper equation, three stem taper models (Max & Burkhart, Kozak, and Lee) were used. Since bamboo stalks are hollow because of its woody characteristics, the outer and inner diameters of the tree were calculated, and connecting them enabled estimating the tree curves. The results of the three equations for estimating the outer and inner diameters led to selection of the Kozak model for determining the optimal stem taper because it had the highest fitness index and lowest error and bias. We used the Kozak model to estimate the diameter of Phyllostachys pubescens by stem height, which proved optimal, and drew the stem curve. After checking the residual degree in the stem taper equation, all residuals were distributed around "0", which proved the suitability of the equation. To calculate the stem volume of Phyllostachys pubescens, a rotating cube was created by rotating the stem curve with the outer diameter at 360°, and the volume was calculated by applying Smalian's method. The volume of Phyllostachys pubescens was calculated by deducting the inner diameter calculated volume from the outer diameter calculated volume. The volume of Phyllostachys pubescens was only 20~30% of the volume of Larix kaempferi, which is a general species. However, considering the current trees/ha of Phyllostachys pubescens and the amount of bamboo shoots generated every year, the individual tree volume was predicted to be small, but the volume/ha was not very different or perhaps more. The significance of this study is the stem taper equation and stem volume table for Phyllostachys pubescens developed for the first time in South Korea. The results are expected to be used as basic data for bamboo trading that is in increasing public and industrial demand and carbon absorption estimation.

Development of a Predictive Model Describing the Growth of Staphylococcus aureus in Pyeonyuk marketed (시중 유통판매 중인 편육에서의 Staphylococcus aureus 성장예측모델 개발)

  • Kim, An-Na;Cho, Joon-Il;Son, Na-Ry;Choi, Won-Seok;Yoon, Sang-Hyun;Suh, Soo-Hwan;Kwak, Hyo-Sun;Joo, In-Sun
    • Journal of Food Hygiene and Safety
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    • v.32 no.3
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    • pp.206-210
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    • 2017
  • This study was performed to develope mathematical models for predicting growth kinetics of Staphylococcus aureus in the processed meat product, pyeonyuk. Growth patterns of S. aureus in pyeonyuk were determined at the storage temperatures of 4, 10, 20, and $37^{\circ}C$ respectively. The number of S. aureus in pyeonyuk increased at all the storage temperatures. The maximum specific growth rate (${\mu}_{max}$) and lag phase duration (LPD) values were calculated by Baranyi model. The ${\mu}_{max}$ values went up, while the LPD values decreased as the storage temperature increased from $4^{\circ}C$ to $37^{\circ}C$. Square root model and polynomial model were used to develop the secondary models for ${\mu}_{max}$ and LPD, respectively. Root Mean Square Error (RMSE) was used to evaluate the developed model and the fitness was determind to be 0.42. Therefore the developed predictive model was useful to predict the growth of S. aureus in pyeonyuk and it will help to prevent food-born disease by expanding for microbial sanitary management guide.

A Structural Model for Depression in Middle-aged Women (중년여성의 우울 구조모형)

  • Park, Geum-Ja;Lee, Kyung-Hye
    • Women's Health Nursing
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    • v.8 no.1
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    • pp.69-84
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    • 2002
  • The purpose of this study was to develope and test the structural model for depression in middle-aged women. A hypothetical model was constructed on the basis of previous studies and a review of literatures. The conceptual framework was built around eight constructs. Exogenous variables included in this model were volunteer activity, health status & economic status. Endogenous variables were meaning of life, self-esteem, perceived life stress & depression. Empirical data for testing the hypothetical model was collected using a self-report questionnaire from 216 middle-aged women in Pusan City. The Data was collected from May to June, 1999. Reliability of the seven instruments tested with Cronbach's alpha was ranged from .86-.94. For the data analysis, SPSS 7.5 WIN Program and LISREL 8.12 WIN Program were used for descriptive statistics and covariance structural analysis. The results of covariance structure analysis were as follows: 1. The hypothetical model showed a good fit with the empirical data. [$x^2$/df=2.87(p=.72), GFI=1.00, AGFI=.98, RMSR=.025, NFI=.99, standardized residuals ($-1.44{\sim}1.44$)]. 2. To heighten for the parsimony and fitness of the model, a modified model was constructed by deleting according to the criteria of statistical significance and meaning. 3. The modified model also showed a good fit with the data. [$x^2$=5.26(01=7,p=.63), GFI=.99, AGFl=.97, RMSR=.025, NFI=.99, standardized reslduals ($-1.50{\sim}1.45$)] Results of the testing of the hypothesis were as follows : 1. Self-esteem(${\beta}_{42}$=-.48, t=-5.64) had a negative and perceived life stress(${\beta}_{43}$=.20, t=3.21)had a positive direct effect on depression. Meaning of life had a negative direct(${\beta}_{41}$=-.17, t=-2.19) and a negative indirect effect through self-esteem on depression. Volunteer activity had a negative indirect effect through meaning of life, meaning of life and self-esteem on depression. Health status had a negative direct and a negative indirect effect through meaning of life, meaning of life and self-esteem on depression. Economic status had a negative indirect effect through perceived life stress on depression. Self-esteem was the most significant variable. 2. Volunteer activity(${\gamma}_{11}$=.43, t=6.78) and health status(${\gamma}_{12}$=.35, t=4.88) had positive direct effect on meaning of life. 3. Meaning of life(${\beta}_{21}$=.50, t=6.53) had a positive direct effect on self-esteem. Volunteer activity had a positive indirect effect through meaning of life on self-esteem. Health status had a positive direct(${\gamma}_{22}$=.18, t=2.23) and a indirect effect through meaning of life on self-esteem. Meaning of life was the most significant variable. 4. Economic status (${\gamma}_{33}$=-.44, t값=-6.01) had a positive direct effect on perceived life stress. The results of this study showed that self-esteem had the most significant direct effect on depression. Meaning of life and health status had significant direct effect on this self-esteem. Volunteer activity and health status had direct effect on meaning of life. The results of this study suggested that there is a need to develope intervention to promote degree of self-esteem and alleviate degree of depression in middle-aged women.

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Impact of a Brand Image Matching with the Advertising Model on Price Fairness Perceptions: Focus on Sports Advertising (브랜드 이미지와 광고모델의 일치성이 가격공정성 지각에 미치는 영향 : 스포츠 광고를 중심으로)

  • Hwang, Hee-Joong;Shin, Seung-Ho
    • Journal of Distribution Science
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    • v.10 no.3
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    • pp.43-50
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    • 2012
  • This study sets out to examine how a brand image that matches the advertising model has a positive impact on brand attitude and price fairness perceptions. We reviewed the constructs on the basis of previous studies and each of the concepts has been redefined. One such concept, "image congruence," refers to the harmony, fitness, and matching quality of images. For example, how well celebrity advertising model is matches the brand image shows image congruence. Results are summarized as follows: First, the congruence of brand image and sports advertising model has no significant impact on brand attitude certainty and persistence. Second, the individual's brand attitude certainty and brand attitude persistence has a positive impact on the perceptions of price fairness. Third, the congruence of brand image and sports advertising model has a positive impact on the perceptions of price fairness. The first and the third results suggest that the positive impact on the price fairness perceptions is temporary but it has insignificant effects on the formation of brand attitude causing ongoing purchases. In other words, in order to influence consumers' long-term confidence on the brand, improving the quality of products or services has to precede promotional strategies such as advertising. When an advertising model is inappropriate for the brand image, consumers perceive product price changes as a negative issue in the short term. However, in the long term, attitude formation such as consumers' repurchase intentions and word of mouth will be not affected. The second result suggests that an already existing positive brand attitude can contribute more positively to change the perceptions of price fairness. In particular, attitude persistence has greater influence than attitude certainty on the price fairness. It suggests that persistence issues such as the trading period and the frequency of transactions must be managed and controlled because they are more important than the certainty issues such as strength of belief or trust. For example, when a commercial model for expensive sporting goods matches up with the brand image, consumer feels less pressure on the price changes. However, it does not determine the consumer's repeated purchases or sustainable transactions and it also has no absolute impact on the brand trust. In other words, consumer brand attitude should be recognized and approached as a routine strategy in view of the result that it is of great value as a causal variable in the process of consumer decision-making.

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Development of a Failure Probability Model based on Operation Data of Thermal Piping Network in District Heating System (지역난방 열배관망 운영데이터 기반의 파손확률 모델 개발)

  • Kim, Hyoung Seok;Kim, Gye Beom;Kim, Lae Hyun
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.322-331
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    • 2017
  • District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

The Effect of Service Quality of Industrial Chemical Product B2B Transactions on Intention to Repurchase (화학 산업재 B2B 거래시장에서의 서비스품질이 지속구매의도에 미치는 영향)

  • Hwang, Moon-Sung;Han, Kyeong-Seok;Lee, Yeong-Mun;Kwon, Hyeon-Jeong
    • Journal of Digital Convergence
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    • v.16 no.5
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    • pp.173-183
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    • 2018
  • In this study, we tried to examine the effect of service quality on the current industrial product B2B trading market on the degree of sustainable purchase for employees engaged in industrial product B2B trading market. We gathered data from questionnaires from employees who worked in the industrial product B2B trading market for this research. Empirical analysis is carried out through the collected questionnaire materials and finally the research model is finally verified using reliability analysis, validity analysis, discrimination validity analysis, and structural equation model fitness test, and finally Analysis of differences between cooperating companies and vendor, analysis of differences between companies engaged in purchasing industrial materials and developers. The results of the research analysis did not positively influence the quality of the relationship with relativity satisfaction with ease of information exchange and adaptability did not have a positive influence on the quality of the relationship. However, product service exchange, product development cooperation, adaptability, correspondence, reliability had a positive influence on the quality of relationship with relation satisfaction. Relationship of parameters The satisfaction has a positive influence on the quality of the relationship, the degree of sustainable purchase, and eventually the quality of the relationship has a positive influence on each successive purchase. By using the results of this research it is possible to confirm the factors which directly or indirectly influence the strengthening of the relationship between suppliers and purchasers in the industrial material B2B trading market and provide the basis for strategy to B2B trading companies It seems to be meaningful to offer.

A Study on Correlations of Job Competence and Job Fitness with Functions of National Technical Qualification in Mechanical Field (기계분야 국가기술자격 기능에 따른 직무능력 직무적합성과의 관계에 관한 연구)

  • Won, Sang-Bong;Kang, Seog-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.12
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    • pp.4707-4714
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    • 2010
  • To determine the influence of qualification on field and currency, the model is presented that there is the connection between job competence and job fit about the function of qualification. To find out this connection, the study is being done and based on this, a clue of qualification on field and currency is tried to figure out. First, in case of national technical qualification holders in Machinery field, the type of the function of qualification(signal, guide, screen functions) of job competence and job fit shows correlation between them. Second, the job competence and job fit of the owner of national technical qualification in Machinery field is mostly affected by signal function. Thirdly, the mediating effect of job competence on the effect of the function of qualification on job-fit is showed by the types of function of qualification. Guide function does not have any mediation effect, but signal function and screen function have the mediation effect. Especially, out of all, signal function is the most affecting factor of mediating effect. Lastly, the model of the relationship between subordinate factors by types of function of qualification on job competence and job fitis presented.

A Structural Analysis of Learner on Adult Female Learners' Learning Outcome (성인여성학습자의 학습성과에 대한 구조분석)

  • Jang, Eun Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.364-372
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    • 2016
  • This study examined the multi-phrased effects and outcomes of adult female learners who participated in lifelong learning activities, as well as the proposed structural relationships among the five latent variables. Questions established to achieve the purpose of the study are as follow: What effects do the learner's characteristics, lifelong education institutions, learning flow, and learning satisfaction have on the learning come? The participants of the survey numbered 632, but 54 respondents who were unreliable or did not complete their survey were excluded. A total of 578 cases were analyzed for this research. The structural relationships among the five latent variables-learner's characteristics, lifelong education institutions, learning flow and learning satisfaction, and learning outcome of the adult female learners-AMOS 18.0 program were also used for structural analysis. The major findings of this research are as follows. First, the model fitness showed that the hypothetical model provided a reasonable fit to the data ${\chi}^2=224.267$ (df=69, p<.001), RMSEA=.062, TLI=.943, RFI=.920, CFI=.957, IFI=.957, NFI=.939. Second, the learner's characteristics ( =.218, p<.001) and lifelong education institutions ( =.301, p<.001) have a direct effect on the learning outcomes. The learning flow ( =-.149 p=.541) does not have a direct effect on the learning outcome. Learning satisfaction ( =.405 p<.001) have a direct effect on the learning outcome. To put findings above together, in respect to adult female learners' performances, the learning outcomes are influenced directly by the learner characteristics, conditions of the lifelong education institutions, and learning satisfaction, whereas satisfaction indirectly affects the learners' learning outcome.

CoMSIA Analysis on The Inhibition Activity of PTP-1B with 3${\beta}$-Hydroxy-12-oleanen-28-oic Acid Analogues (3${\beta}$-Hydroxy-12-oleanen-28-oic Acid 유도체들의 PTP-1B저해활성에 대한 CoMSIA분석)

  • Kim, Sang-Jin;Chung, Young-Ho;Kim, Se-Gon;Sung, Nack-Do
    • Applied Biological Chemistry
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    • v.51 no.3
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    • pp.171-176
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    • 2008
  • The comparative molecular similarity indices analysis (CoMSIA) models between 3${\beta}$-Hydroxy-12-oleanen-28-oic acid (1-30) analogues as substrate molecule and their inhibitory activities ($pI_{50}$) against protein tyrosine phosphatase (PTP)-1B were derived and discussed quantitatively. Listing in order, the CoMFA>CoMSIA${\geq}$HQSAR>2D-QSAR model, these QSAR models had the better statistical values. The optimized CoMSIA F1 model at grid 3.0${\AA}$ had the best predictability and fitness ($q^2$=0.754 and $r^2$=0.976) by field fit alignment. The order of contribution ratio (%) of CoMSIA fields concerning the inhibitory activities was a H-bond acceptor (48.9%), steric field (25.8%) and hydrophobic field (25.4%), respectively. Therefore, the inhibitory activities of substrate molecules against PTP-1B were dependent upon H-bond acceptor field (A) of $R_4$-group. From the analytical results of CoMSIA contour maps, oleanolic acid derivatives will have better inhibition activities if $R_1$ group has H-bond acceptor disfavor, $R_3$group has steric disfavor and $R_4$ group has steric, hydrophobic, H-bond favor.

The Effect of Adult's Name Attractiveness on Self-efficiency and Emotionality (성인의 이름매력도가 자기효능감과 정서에 미치는 영향)

  • Kim, Ki-Seung;Ham, Hae-Soo;Na, Hyeok-Jin
    • Industry Promotion Research
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    • v.5 no.1
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    • pp.99-106
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    • 2020
  • The purpose of this study was to analyze the effects of name attractiveness on self-efficacy and emotional awareness in adult men and women. The subjects of this study were 300 males and females in their 10s and 30s living in the metropolitan area. However, 250 copies, excluding missing questionnaires during the collection process and incomplete questionnaires, were used for the analysis. As a result of analyzing the difference in name attractiveness according to factors, the lower the age group and the lower the academic level, the more dissatisfied they were with their names. Besides, the regression analysis conducted to verify the effect of name attractiveness on self-efficacy showed that the model's fitness was R2=.382 and the model's explanatory power was somewhat inferior, but β=.322, t-value 9.276, p<.001 were shown to be statistically significant, so name attraction directly affects self-efficacy. And the results of the regression analysis conducted to verify the effect of name attractiveness on emotionality turned out to be R2=.412. The regression analysis, which controls demographic variables such as gender, age, and academic level, was statistically significant as β=.326, t-value 6.408, p<.001. In other words, the name attractiveness affects emotional awareness. There is no empirical study that the name attractiveness can improve happiness or the quality of life, but it seems often among athletes that names are enhanced by the past.