• Health Policy and Management
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• v.14 no.3
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• pp.66-96
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• 2004

This study was intended to describe the hypertensive patient's lifestyle and quality of life by creating a hypothetic model on the lifestyle and quality of life and by examining a causeand effect relationship, and to contribute to countermeasures for practicing their lifestyle and improving the quality of life through creating a predictable model. Exogenous variable($\xi$) of hypothetic model in this study composed of a family support, hypertension knowledge, perceived benefit and toughness. Endogenous variable($\eta$) composed of self-esteem, perceived health state, depression, lifestyle and quality of life. There were 6 measured variables for exogenous variable(x). There were 9 measured variables(y) for endogenous variable. Also, there was error variable ($\delta,\;\epsilon$) of an individual. The survey was conducted for 207 hypertensive parents who received an out-patient service for 3 weeks from September 15, 2003 to October 3, 2003 after diagnosing as hypertension from 2 general hospitals in Daegu. As the conformance of hypothetic model in this study, there were $x^2$= 155.81, standard $x^2$ ($x^2$/df)=2.32, GFI=0.003, NFI=0.971, CFI=0.982, and RMSEA=0.080. Generally, the hypothetic model and actual data were well coincided. The higher the hypertension knowledge was(t=6.030), the higher the perceived benefit was(t=9.429), the higher the toughness was(t=2.783), and the higher the perceived health state was(t=2.282), the higher the lifestyle was. However, the degree of depression (t=-0.038), family support(t=1.161), and self-esteem(t=0.518) was not affected. The higher the family support was(t=10.476), the higher the self-esteem was(t=7.244), the higher the perceived health state was(t=6.996), the lower the degree of depression was(t=-2.044), and the higher the practice degree of lifestyle was(t=3.315), the higher the quality of life was. However, the toughness(t=1.672) didn't have a significant influence on the quality of life. It was modified to increase the model conformance and gain a conscious model As the result of model revision, for the model conformance, there were $x^2$= 118.43, standard $x^2$=1.69, GFI=0.923, NFI=0.976, CFI=0.982, and RMSEA=0.078. As the revised model showed the better conformance than hypothetic model, it seemed to be more suitable model. In the revised model, the perceived benefit(t=9.440) affected the lifestyle in the revised model. Then, the lifestyle was influenced by hypertension knowledge(t=6.139), toughness (t=2.757), family support(t=2.078), perceived health state(t=1.962) in the order. As a factor which affected the quality of life, there were the family support(t=l0.46l), self-esteem(t=7.368), perceived health state(t=6.989), lifestyle(t=3.316), toughness(t=2.584), and depression(t=-1.968) in the order. It showed the significant effect.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.732-735
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• 1997

Variable Structure Controller(VSC) is usually known to have robustness to bounded exogenous disturbances. The robustness is attributed to the discontinuous term in the control input. However, this discontinuous term also causes an undesirable effect called chattering. To alleviate chattering, a hybrid controller consisting of VSC and Fuzzy Logic Controller(FLC) is proposed, which belongs to the category of Fuzzy Sliding Mode Controller(FSMC). The role of FLC in FSMC is to replace a fixed gain of a discontinuous term with a time-varying one based on a specified rule base. The characteristics of proposed controller are shown to be similar to those of VSC with a saturation function instead of sign function. The only remarkable difference is the nonlinearity whose form can be adjusted by free parameters, normalize gain, denormalize gain, and membership functions. Applied to AC servo motor, the proposed controller is compared with VSC in a regulation problem as well as a speed tracking problem. The simulation results show a substantial chatter reduction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.3
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• pp.354-362
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• 2000

This paper identifies a discrete-time linear combustion model of Refuse Incineration Plant(RIP) which characterizes steam generation quantity, where the RIP is considered as a MIMO system with thirteen-inputs and one-output. The structure of RIP model is described as an ARX model which are analytically obtained from the combustion dynamics. Furthermore, using the Instrumental Variable(IV) identification algorithm, model structure and unknown parameters are identified from experimental input-output data sets, In result, it is shown that the identified ARX model well approximates the input-output combustion characteristics given by experimental data sets.

• The International Journal of Costume Culture
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• v.7 no.1
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• pp.58-69
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• 2004

This study generated a framework to help academicians understand consumers' cultural values and global-mindedness Especially, this study affirmed the importance of fashion involvement in evoking global-mindedness when consumers have strong traditional values. A conceptual model with non-traditional and traditional values as exogenous variables, global-mindedness as endogenous variable and fashion involvement as mediating variable were created for the study. Data from 224 female college students were analyzed for empirical study. Results indicated that college students showed higher level of non-traditional values than traditional values. Non-traditional values had significant direct influence on global-mindedness whereas traditional values did not have significant influence. Traditional values as well as non-traditional had significant influence on fashion involvement. Fashion involvement significantly affected global-mindedness. Both non-traditional values and traditional values had significant positive indirect effects on global-mindedness mediated by fashion involvement.

• Journal of Fashion Business
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• v.15 no.4
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• pp.87-109
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• 2011

This study was to examined the relationship between goal setting, self improvement, social support of parents, friendship, school adaptation, drop out. In our research model, goal setting, self improvement, social support of parents, and friendship is exogenous variable and school adaption and drop out is endogenous variable. A total of 323 undergraduate student(254 female, 69 male) complete the questionnaires. Structural equation modelling showed that, as hypothesized, establishment of goals, social support of parent and friendship have effect on school adaptation, and friendship also have direct effect on drop out. School adaptation mediate path from goal setting, social support of parents, and friendship. This study provides empirical evidence for a model that show how to control the drop out of students.

• Fashion & Textile Research Journal
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• v.22 no.5
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• pp.570-583
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• 2020

The fashion industry is accountable for labor and environment-related issues. With such issues raised, consumers' social responsibility for environmental and labor issues has become an important factor that shapes the perception of companies. This study investigates the relationship between consumer values, concerns regarding social issues, and willingness to pay a premium for ethical fashion products. This study included two exogenous variables of altruistic value and egocentric value. In the conceptual model, consumers' social responsibility was conceptualized as two constructs of environmental consciousness and labor-issue consciousness. It was then analyzed as mediating variables. Willingness to pay a premium for ethical fashion products was the endogenous variable. Data was collected and analyzed with PLS-SEM from 600 consumers. The assessment of discriminant validity and construct validity using CFA were conducted before analyzing the model. Structural equation modeling results revealed that altruistic value directly influenced environmental consciousness and labor-issue consciousness. However, egocentric value was directly and significantly influenced only by labor-issue consciousness. Both environmental and labor issue consciousness directly influenced customers' willingness to pay a premium, but did not significantly change their willingness to pay a premium. Two-stage serial mediation analysis results indicated that the constructs did not have a significant mediation effect on the exogenous variables (altruistic value and egocentric value) and the endogenous variable (willingness to pay a premium) for ethical fashion products. This study found the influence of consumer's personal values on their willingness to pay a higher price for ethical fashion products.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.450-461
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• 2016

This study set out to analyze the effects of user personality on the brand satisfaction and loyalty of SNS to identify factors influencing SNS usage. For that purpose, the study defined extraversion, curiosity, and self-esteem, three factors of Instagram user personality, as exogenous variables, focusing on Instagram, which has made a relatively sharp rise in the usage rate among many different SNS applications. With brand satisfaction and loyalty set as endogenous variables, the investigator introduced brand satisfaction as a mediating variable for the effects of extraversion, curiosity, and self-esteem on brand loyalty. A survey was conducted with Korean people with an experience of using Instagram, and total 396 questionnaires were used in final analysis. The findings show that all of three exogenous variables had positive (+) effects on brand satisfaction with extraversion and curiosity having positive (+) effects on brand loyalty, as well. And the findings demonstrate that brand satisfaction was a mediating variable and that curiosity was the personality factor that had the biggest influences on satisfaction and loyalty.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.538-555
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• 2014

Systematic studies have been rarely conducted on the acceptance of big data technology despite the technology drawing much attention from academia, industry and general public. With big data technology still being in the infant stage in Korea, a study model was constructed in this paper by integrating the innovation diffusion theory and the task technology fit theory with this technology acceptance model (TAM) as the central framework to make big data technology more readily acceptable in the country, and the aim of making big data technology readily acceptable was expanded as the moderator variable of the TAM. The results of this study showed that "subjective norm" and "task technology fit" showed the most significant effect as the exogenous variables of the TAM. In addition, the "innovative characteristic of the organization" was the significant exogenous variable affecting the intention to accept big data technology to those "technology utilizers" that try to come up with new services or products that are technology-based; however, "subjective norm" was the rather significant factor affecting those simple "technology users". Finally, a significant difference was seen in the verification of mediation effect.

• The Journal of Information Systems
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• v.22 no.4
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• pp.85-115
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• 2013

Digital knowledge and information goods as experience goods have some unique characteristics such as close to zero reproduction and distribution cost, high price volatility, and low price acceptability. For the reasons, the pricing policies of digital knowledge goods are very difficult and complicate. Also, most consumers of digital goods have experienced cognitive dissonance after buying decision. The purpose of this paper is to investigate what factors affect the price acceptability level and cognitive dissonance of digital knowledge goods buyers. This paper suggest a structural model that was established by the cognitive dissonance theory and S-O-R(Stimulus-Organization-Response) model. The model is consisted of four exogenous variables and three endogenous variables. The empirical test and statistical analysis suggest following results and practical implications. The variables such as product involvement and perception of price fairness that have positive roles to price acceptability have strong influence on the all the three endogenous variables. But the variables such as sale proneness and price mavenism that have negative roles to price acceptability have little influence on the all the three endogenous variables. In the model, the payment intention was very important mediating variable between exogenous variables and two dependent variables, ie. price acceptability and cognitive dissonance. These results imply that the digital knowledge portals must have some differentiated pricing policies to the customers who have price consciousness and price mavenism. Also, they need some special promotions to whom have positive attitude to the value of digital goods.

• Communications for Statistical Applications and Methods
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• v.30 no.2
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• pp.163-178
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• 2023

GARCH-X(1, 1) model specifies that conditional variance follows an AR(1) process and includes a past exogenous variable. This study proposes a new class from that model by allowing a more general (non-linear) variance function to follow an AR(1) process. The functions applied to the variance equation include exponential, Tukey's ladder, and Yeo-Johnson transformations. In the framework of normal and student-t distributions for return errors, the empirical analysis focuses on two stock indices data in developed countries (FTSE100 and SP500) over the daily period from January 2000 to December 2020. This study uses 10-minute realized volatility as the exogenous component. The parameters of considered models are estimated using the adaptive random walk metropolis method in the Monte Carlo Markov chain algorithm and implemented in the Matlab program. The 95% highest posterior density intervals show that the three transformations are significant for the GARCHX(1, 1) model. In general, based on the Akaike information criterion, the GARCH-X(1, 1) model that has return errors with student-t distribution and variance transformed by Tukey's ladder function provides the best data fit. In forecasting value-at-risk with the 95% confidence level, the Christoffersen's independence test suggest that non-linear models is the most suitable for modeling return data, especially model with the Tukey's ladder transformation.