• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.419-422
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• 1996

In this paper, we consider variable structure controller design of a active magnetic bearing(AMB). In particular, we design a switching hyperplane, considering coupling characteristic among each magnet. This method is designed by applying decentralized control method. Controller design consist of two factors that is, one is linear control part to drive state variables to zero asymptotically and the other is a nonlinear controller part to maintain within neighborhood of switching hyperplane. Finally, A control method designed here is checked by simulation, which shows good results.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.945-950
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• 1991

A method to design a robust servomechanism by continuously variable structure control is proposed. The state and control signal of this servomechanism do notchatter since a continuous control scheme is used. The input-output relation of this servomechanism is determined by prescribing a hyperplane in a state space of which the neighborhood is asymptotically attractive everywhere. This control mechanism was applied to a single rod cylinder servomechanism which has the nonlinerities due to their nonsymmetrical structure and its excellency was verified.

• Spatial Information Research
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• v.21 no.6
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• pp.81-89
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• 2013

Recently, several studies conducted for other countries show that housing price has very close relationship with personal or neighborhood level obesity. Also these studies suggest the use of housing price as a new SES(Socio-Economic Status) variable for health related studies. In this study, whether this relationship can be found in regions of the Seoul Metropolitan Area is investigated. The results of this study show that, as in the cases of other countries, the regions with SES represented by higher housing prices show lower obesity levels. Further, the results show that the differences in regional housing prices well explain the variations of regional obesity levels as other traditional SES variables do. This finding indicates that housing price which is objectively, continuously, and spatially measured in Korea can be used as a new SES indicator for health research in Korea.

• Journal of Families and Better Life
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• v.27 no.4
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• pp.41-54
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• 2009

This study focused on the ecological variables that affect adolescents' runway impulse. For the organisms, self-esteem, impulse control, school achievement and runway experience, for the microsystems, family, school and peer environment, for the mesosystems, family-peer relationships and family-school relationships, and for the exosystem, neighborhood environment were included. The sample consisted of 651 eleventh grade adolescents. Instruments were the Runway Impulse Scale(Nam, 2001) and Index of organisms, microsystems, mesosystems, and exosystem variables. Statistics and methods used for the analysis were Cronbach's alpha, frequency, percentage, t-test, Pearson's correlation and multiple Regression. Several major results were found from the analysis. First, no sex difference was found in adolescents' runway impulse. Second, runway impulse of male and female adolescents showed positive correlations with runway experience, parental marital conflict, dissatisfactions of school life and exposure to friends with problems behavior but negative correlations with self-esteem, impulse control, school achievement, parental support and supervision, teacher support, family-peer relationships and neighborhood environment. Female adolescents' runway impulse stowed negative correlations with family-school relationships. Third, the most important variable predicting male adolescents' runway impulse was exposure to friends with problems behavior, the most important variable for female was self-esteem.

• Journal of Urban Science
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• v.10 no.1
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• pp.21-28
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• 2021

The purpose of this study is to examine the factors affecting the housing satisfaction of elderly households in comparison with non-elderly households, and to present policy implications in terms of housing welfare policies. For this purpose, this study used ordered logit model analysis using '2019 Housing survey data'. As a result of the analysis, in the case of individual/housing characteristics, the analysis results of the non-elderly household model and the elderly household model were similar. However, in the case of regional characteristics, non-elderly households living in the metropolitan area showed higher housing satisfaction than non-elderly households living in the non-metropolitan area, whereas the elderly households living in the metropolitan area had lower housing satisfaction than the elderly households living in the non-metropolitan area. In addition, the satisfaction variable of neighborhood/environmental characteristics that had the greatest impact on the housing satisfaction of non-elderly households was found to be crime prevention status satisfaction, and the satisfaction variable of neighborhood/environmental characteristics that had the greatest impact on the housing satisfaction of elderly households was air pollution satisfaction. The results of the analysis can be used as various reference materials when establishing housing welfare policies for elderly households.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.36-42
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• 2021

This paper deals with a vehicle routing problem with resource repositioning (VRPRR) which is a variation of well-known vehicle routing problem with pickup and delivery (VRPPD). VRPRR in which static repositioning of public bikes is a representative case, can be defined as a multi-objective optimization problem aiming at minimizing both transportation cost and the amount of unmet demand. To obtain Pareto sets for the problem, famous multi-objective optimization algorithms such as Strength Pareto Evolutionary Algorithm 2 (SPEA2) can be applied. In addition, a linear combination of two objective functions with weights can be exploited to generate Pareto sets. By varying weight values in the combined single objective function, a set of solutions is created. Experiments accomplished with a standard benchmark problem sets show that Variable Neighborhood Search (VNS) applied to solve a number of single objective function outperforms SPEA2. All generated solutions from SPEA2 are completely dominated by a set of VNS solutions. It seems that local optimization technique inherent in VNS makes it possible to generate near optimal solutions for the single objective function. Also, it shows that trade-off between the number of solutions in Pareto set and the computation time should be considered to obtain good solutions effectively in case of linearly combined single objective function.

• Journal of the Korean Home Economics Association
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• v.48 no.1
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• pp.83-96
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• 2010

This study was conducted to derive useful predictive variations for the qualitative supply of homes to provide information to real estate venture businesses and other business owners in neighborhood amenities and significant basic information to housing suppliers and policy makers. For this purpose, a number of apartment dwellers in Seoul were surveyed to examine their housing satisfaction, difference in housing satisfaction according to variables, and any relevant correlations. In detail, 500 apartment dwellers in Seoul were surveyed from September 1, 2009 to September 20, 2009 to gather resources that were processed through SPSS 14.0 to find percentage of frequency, mean, standard deviations, t-test, ANOVA, and Duncan Multiple Ranger's Test. The following were the findings of this study: First, housing satisfaction of apartment dwellers in Seoul was above average with the highest satisfaction with neighborhood environment. Second, satisfaction with amenities was significantly affected by dweller-related variables. Gangnam dwellers were more satisfied with housing environment and community environment than Gangbuk dwellers. By age, people in 20s and 30s showed high satisfaction with housing environment. Satisfaction with community environment was high among 20s, 30s and 40s. Satisfaction with management conditions was high among 20s. Also, satisfaction was high when housing period was between 1 and 10 years. By size, dwellers in 40py or larger homes showed high satisfaction with housing environment and management conditions. Dwellers in 30py and 40py or larger homes were satisfied with community environment. By ownership, dwellers with ownership of their homes showed high satisfaction. Third, there was a significant difference in satisfaction with neighborhood and social environments according to dweller-related variables. By region, dwellers of Gangnam area showed high satisfaction with neighborhood environment. By age, people in 20s, 30s and 40s showed high satisfaction with neighborhood environment. Also, satisfaction with neighborhood environment was high when housing period was around 10 years. By size, dwellers in 30py and 40py or larger homes were satisfied with neighborhood and social environments. Fourth, there was a close correlation between satisfaction with housing environment and satisfaction with community environment, and between satisfaction with community environment and satisfaction with management conditions. Thus, most dwellers that were satisfied with one variable of housing environment showed high satisfaction with other variables.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.662-674
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• 2017

This paper describes the multidisciplinary design optimization (MDO) process of a tailless unmanned combat aerial vehicle (UCAV) using global variable fidelity aerodynamic analysis. The developed tailless UAV design framework combines multiple disciplines that are based on low-fidelity and empirical analysis methods. An automated high-fidelity aerodynamic analysis is efficiently integrated into the MDO framework. Global variable fidelity modeling algorithm manages the use of the high-fidelity analysis to enhance the overall accuracy of the MDO by providing the initial sampling of the design space with iterative refinement of the approximation model in the neighborhood of the optimum solution. A design formulation was established considering a specific aerodynamic, stability and control design features of a tailless aircraft configuration with a UCAV specific mission profile. Design optimization problems with low-fidelity and variable fidelity analyses were successfully solved. The objective function improvement is 14.5% and 15.9% with low and variable fidelity optimization respectively. Results also indicate that low-fidelity analysis overestimates the value of lift-to-drag ratio by 3-5%, while the variable fidelity results are equal to the high-fidelity analysis results by algorithm definition.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1995.10a
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• pp.77-83
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• 1995

This study explores the patterns of housing-related attitudes and the kind of needs for shared community spaces among small-sized apartment housing dwellers. The major findings are as follows. The majority of the dwellers are in strong need of common spaces, especially for children's activities, Social gathering and physical exercises. Housing-related attitudes are found and grouped into 4categories the propensity to making up common society, the propensity to pursuing the quality of neighborhood, the propensity to orienting natural environment, and the propensity to participating in community. The intensity of the needs depends on family lifecycle, employment status of housewives, and the size of floor space. The propensity to making up common society and pursing the quality of neighborhood have stronger impact on needs of shared community space. This study reveals that the sense of community orientation is the most powerful predictor variable for shared community space needs .

• Journal of the Korean housing association
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• v.8 no.3
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• pp.91-98
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• 1997

This study explores the patterns of housing-related attitudes and the kind of needs for shared community spaces among small-sized apartment housing dwellers. The major findings are as follows. The majority of the dwellers are in a strong need of common spaces. especially for children's activities. social gathering and physical exercises. Housing consciousness can be grouped into 4 categories the propensity to making up common society. the propensity to pursuing the quality of neighborhood. the propensity to orienting natural environment. and the propensity to participating in community. Families with children in primary school are more likely to get involved in the community and the common society than those with children in high school or those in the stage of launching a family. The propensity to making up common society and pursing the quality of neighborhood have stronger impact on needs for shared community space. This study reveals that the sense of community orientation is the most powerful predictor variable for shared community space needs.