• KSCE Journal of Civil and Environmental Engineering Research
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• 제34권2호
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• pp.617-626
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• 2014

Lately, losses and damage from natural disasters have been increasing. Researchers across various fields in Korea are trying to come up with a response plan, but research for evacuation plans is still far from satisfactory. Hence this paper proposes a model that could find an optimized evacuation route for when disasters occur over wide areas. Development of the model used methods including the Dijkstra shortest path algorithm, feasible path method, genetic algorithm, and pareto efficiency. Computations used parallel computing (SPMD) for high performance. In addition, the developed model is applied to a virtual network to check the validity. Finally the adaptability of the model is verified on a real network by computating for Gumi 1stNational Industrial Complex. Computation results proved that this model is valid and applicable by comparison of the fitness values for before optimization and after optimization. This research can contribute to routing for responder vehicles as well as planning for evacuation by objective when disasters occur.

• The Journal of the Korea Contents Association
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• 제15권7호
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• pp.128-137
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• 2015

Going through rapid changes, the field of information technology (IT) has launched many innovative products. Some of those products have spread, forming a stable market, whereas others have disappeared. The purpose of the study is to purpose a theoretical model to show changes in the importance of competition factors over the three stages. Our study applied the innovation adoption stage model of the Innovation Diffusion Theory (IDT) to the industry life cycle of the Industry Life Cycle (ILC) Theory resulting in three stage of introduction, growth, and maturity, and defined a model of market characteristics according to time. By using the model, we analyzed the case of notebook computers and tablet and checked the fitness of the model. Results show that five competition factors worked differently according to time. In the introduction stage, relative functionality and relative playfulness are important competition factors. In the growth stage, compatibility is added to those two factors. In the last maturity stage, compatibility, complexity, and cost level are important competition factors.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제15권1호
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• pp.16-27
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• 2016

This study identified the factors which affect pedestrian behavior using the tobit model with a descriptive analysis. Individual characteristics, household characteristics, zone characteristics were selected as the independent variables. Walking frequency and walking time was adopted for the variables which represent walking behavior. The results showed that the walking time models were superior than the walking frequency models. The model for education purpose had the most lowest fitness and the model for others purpose had characteristics mixed up the various purposes. Futhermore, this research found that independent variables: individual, household and zone characteristic variables affected walking activities of elderly pedestrian by purpose. The walking activity decresed when a pedestrian grew older or had a vehicle or a driver's license. The Elderly facilities promoted the walking activity of seniors. As the floor area of neighborhood and business facilities was wide, the walking activities were animated. In addition, the compacted downtown developments decreased the elderly's walking activities, so it is needed to consider those results in terms of the urban planners.

• Journal of Korean Academy of Nursing
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• 제47권2호
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• pp.257-266
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• 2017

Purpose: The aims of this study were to construct a hypothetical structural model which explains premenstrual coping in university students and to test the fitness with collected data. Methods: Participants were 206 unmarried women university students from 3 universities in A and B cities. Data were collected from March 29 until April 30, 2016 using self-report structured questionnaires and were analyzed using IBM SPSS 23.0 and AMOS 18.0. Results: Physiological factor was identified as a significant predictor of premenstrual syndrome (t=6.45, p<.001). This model explained 22.1% of the variance in premenstrual syndrome. Psychological factors (t=-2.49, p=.013) and premenstrual syndrome (t=8.17, p<.001) were identified as significant predictors of premenstrual coping. Also this model explained 30.9% of the variance in premenstrual coping in university students. A physiological factors directly influenced premenstrual syndrome (${\beta}=.41$, p=.012). Premenstrual syndrome (${\beta}=.55$, p=.005) and physiological factor (${\beta}=.23$, p=.015) had significant total effects on premenstrual coping. Physiological factor did not have a direct influence on premenstrual coping, but indirectly affected it (${\beta}=.22$, p=.007). Psychological factors did not have an indirect or total effect on premenstrual coping, but directly affected it (${\beta}=-.17$, p=.036). Conclusion: These findings suggest that strategies to control physiological factors such as menstrual pain should be helpful to improve premenstrual syndrome symptoms. When developing a program to improve premenstrual coping ability and quality of menstrual related health, it is important to consider psychological factors including perceived stress and menstrual attitude and premenstrual syndrome.

• Journal of Korean Academy of Nursing
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• 제41권4호
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• pp.481-490
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• 2011

Purpose: The purpose of this study was to identify from the International Classification of Functioning model, factors influencing quality of life in elderly persons and to describe the concrete pathway of influence and the power of each variable. Methods: The sample included 334 elders who lived in 5 districts of D Metropolitan City. A structured questionnaire was used and the collected data were analyzed for fitness, using the AMOS 18.0 program. Results: This model was concise and extensive in predicting the quality of life of elders. The research verified the factors influencing quality of life for elders as direct factors such as activity of daily living (ADL) (${\beta}$=.13, t=2.47), leisure activity (${\beta}$=.55, t=5.04), social disengagement (${\beta}$=-.25, t=-2.25), and depression (${\beta}$=-.62, t=-10.86). Indirect factors including economic status (${\gamma}$=.17, p=.009), type of residence (${\gamma}$=.19, p=.004), ADL (${\gamma}$=.12, p=.027) were important factors in predicting quality of life for elders. These variables explained 75.6% of variance in the prediction model. Conclusion: The findings indicate a need for the nursing scientific community to develop intervention programs considering these variables to improve the quality of life for elders.

• Journal of The Korean Society of Grassland and Forage Science
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• 제36권3호
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• pp.223-236
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• 2016

The objective of this study was to construct Italian ryegrass (IRG) dry matter yield (DMY) estimation models in South Korea based on climatic data by locations. Obviously, the climatic environment of Jeju Island has great differences with Korean Peninsula. Meanwhile, many data points were from Jeju Island in the prepared data set. Statistically significant differences in both DMY values and climatic variables were observed between south areas of Korean Peninsula and Jeju Island. Therefore, the estimation models were constructed separately for south areas of Korean Peninsula and Jeju Island separately. For south areas of Korean Peninsula, a data set with a sample size of 933 during 26 years was used. Four optimal climatic variables were selected through a stepwise approach of multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the selected four climatic variables and cultivated locations as dummy variables was constructed. The model could explain 37.7% of the variations in DMY of IRG in south areas of Korean Peninsula. For Jeju Island, a data set containing 130 data points during 17 years were used in the modeling construction via the stepwise approach of multiple regression analysis. The model constructed in this research could explain 51.0% of the variations in DMY of IRG. For the two models, homoscedasticity and the assumption that the mean of the residuals were equal to zero were satisfied. Meanwhile, the fitness of both models was good based on most scatters of predicted DMY values fell within the 95% confidence interval.

• Culinary science and hospitality research
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• 제23권3호
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• pp.123-136
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• 2017

This study aims to understand the influence of employees' perceptions of organizational politics (POP) on organizational silence (OS) and turnover intention (TI) in the foodservice industry and to verify the moderating effects of departments (food & beverage and kitchen) in the relationship among the POP, OS, and TI. Based on a total of 313 useful samples obtained for the empirical research, this study reviewed the reliability and fitness of the research model and verified a total of 2 hypotheses using the AMOS program. The hypothesized relationships in the model were tested simultaneously by using a structural equation model(SEM). The proposed model provided an adequate fit for the data, $x^2=349.889$ (p<0.001), df=100, CMIN/DF=3.499, GFI=0.882, NFI=0.880, CFI=0.911, RMSEA=0.089. The model's fit, as indicated by these indexes, was deemed satisfactory, thus providing a good basis for testing the hypothesized paths. The results of SEM showed that foodservice employees' POP had positive impacts on the defensive silence (DS) and acquiescent silence (AS). In addition, DS and AS had a positive influence on TI. The department (food & beverage and kitchen) was found to have a partial moderating effect in the relationship between POP, OS, and TI. Based on the research findings, we discussed the practical implications and suggestions for the future research.

• Journal of the Korean Institute of Intelligent Systems
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• 제15권3호
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• pp.375-381
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• 2005

Usually genetic algorithms are used to design optimal system. However the performance of the algorithm is determined by the fitness function and the system environment. It is expected that a co-evolutionary algorithm, two populations are constantly interact and co-evolve, is one of the solution to overcome these problems. In this paper we propose three types of co-evolutionary algorithm to solve GA-Hard problem. The first model is a competitive co-evolutionary algorithm that solution and environment are competitively co-evolve. This model can prevent the solution from falling in local optima because the environment are also evolve according to the evolution of the solution. The second algorithm is schema co-evolutionary algorithm that has host population and parasite (schema) population. Schema population supply good schema to host population in this algorithm. The third is game model-based co-evolutionary algorithm that two populations are co-evolve through game. Each algorithm is applied to visual servoing, robot navigation, and multi-objective optimization problem to verify the effectiveness of the proposed algorithms.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제43권3호
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• pp.101-111
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• 2020

Companies struggle to make their best products with high quality and service at a competitive price in global markets. However, customer needs and requirements keep changing with a variety of situations. Companies that face the changes can not stay the same and make an effort to adapt themselves to new circumstances. They would probably review the overall management system that is currently implementing to improve management efficiency. Among other things, quality might be considered to be a crucial element if they are manufacturing industries to be sustained in global markets. KSA (Korean Standards Association) is a government-affiliated organization under the Ministry of Trade, Infrastructure, and Energy. It is a Korean standards provider for quality and service industry. KSA confers national commendations for organizations, quality circles, artisans, QCEC (Quality Competitive Excellent Company), and the most honorable KNQA (Korean National Quality Award) every year. KSA established KNQA on the basis of Malcom Baldrige National Quality Award, Deming Prize, and European Quality Award. Research on quality awards shows that there are many similarities in the framework. Although KSA summarizes two factors for 13 evaluation indicators in the quality competitive excellent model of QCEC, the categorization is ambiguous to explain them according to earlier studies. We performed a deep analysis of foreign quality awards and background for KNQA and QCEC. We conducted a content analysis of KNQA and QCEC and matched evaluation items that were closely related. We proposed a quality competitiveness model with three factors, Technology, System, and Tools, summarizing 13 evaluation indicators in QCEC. Based on audit data for six years from 2012 to 2017 we carried out a confirmatory factor analysis for the proposed model by examining the model validity and fitness.

• Journal of Digital Convergence
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• 제15권2호
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• pp.251-262
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• 2017

This study distinguishes between factors that affect mental health of college students, establishes an effective approach to integrating model building, mental health promotion, and development of nursing intervention based on the Bronfenbrenner's ecological system theory. The study method investigate the causal relationship between the factors. The SPSS 20.0 program was used for general characteristics and mental health related characteristics. The fitness of the model was verified and the Amos 20.0 program was used for hypothesis verification. In the study, the fit index of the model was $x^2=614.90$ (p = .000), Q value = 3.5, GFI = .88, AGFI = .84, NFI = .92, NNFI = .94, CFI = .02, and RMSEA = .08, respectively. The results showed that stress was the most influential on mental health, and that stress coping strategies, self - esteem and parenting attitude affect mental health. In order to improve the mental health of college students, intervention should be carried out to develop nursing interventions to improve stress management, self - esteem, and coping with stress.