• Structural Engineering and Mechanics
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• 제60권6호
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• pp.1093-1117
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• 2016

Global sensitivity analysis (GSA) has been widely used to investigate the sensitivity of the model output with respect to its input parameters. In this paper a new single-solution search optimization algorithm is developed based on the GSA, and applied to the size optimization of truss structures. In this method the search space of the optimization is determined using the sensitivity indicator of variables. Unlike the common meta-heuristic algorithms, where all the variables are simultaneously changed in the optimization process, in this approach the sensitive variables of solution are iteratively changed more rapidly than the less sensitive ones in the search space. Comparisons of the present results with those of some previous population-based meta-heuristic algorithms demonstrate its capability, especially for decreasing the number of fitness functions evaluations, in solving the presented benchmark problems.

• Journal of Advanced Marine Engineering and Technology
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• 제40권2호
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• pp.138-145
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• 2016

This paper proposes an improved tabu search method for subset selection in multiple linear regression models. Variable selection is a vital combinatorial optimization problem in multivariate statistics. The selection of the optimal subset of variables is necessary in order to reliably construct a multiple linear regression model. Its applications widely range from machine learning, timeseries prediction, and multi-class classification to noise detection. Since this problem has NP-complete nature, it becomes more difficult to find the optimal solution as the number of variables increases. Two typical metaheuristic methods have been developed to tackle the problem: the tabu search algorithm and hybrid genetic and simulated annealing algorithm. However, these two methods have shortcomings. The tabu search method requires a large amount of computing time, and the hybrid algorithm produces a less accurate solution. To overcome the shortcomings of these methods, we propose an improved tabu search algorithm to reduce moves of the neighborhood and to adopt an effective move search strategy. To evaluate the performance of the proposed method, comparative studies are performed on small literature data sets and on large simulation data sets. Computational results show that the proposed method outperforms two metaheuristic methods in terms of the computing time and solution quality.

• 한국산학경영학회:학술대회논문집
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• 한국산학경영학회 2005년도 추계학술발표대회 발표논문집
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• pp.1-9
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• 2005

Job search research has been criticized for failing to study the dynamics and change of the job search process. A lot of previous researches have used cross-sectional designs and treated job search as a static process. As a result, job search research has failed to examine how job seekers' behaviors change during the course of their search. This paper examined changes In job search behaviors(preparatory and active job search behavior, and job search intensity) and the effects of individual difference variables(self-esteem, self-efficacy, extroversion, agreeableness, conscientiousness, openness) on job search behaviors. Data were gathered from 404 university students who had not found employment at the time of beginning of second semester The results of t-test pairs indicated that job seeking students increased their preparatory job search behavior and active job search behavior, but didn't job search intensity. The results of multiple regression showed that self-efficacy had strong relationship with preparatory and active job search behavior, and job search intensity, but self-esteem had not any relationship with them. Among big-5 personality, extroversion had relationship with active job search behavior and job search intensity, and agreeableness only with job search intensity.

• 농촌지도와개발
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• 제8권2호
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• pp.201-208
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• 2001

The purpose of this study was to review the current studies on community attachment and its related variables to suggest directions for community attachment studies in Korea. Specific objectives of the study were to search the current studies on community attachment, to search for the significant variables related to community attachment, and to draw implications for community development in Korea. The major findings of the study were as follows; 1) Current studies on community attachment used individual characteristic variables such as length of residence in the community, age, size of population and density as major independent variables. 2) Studies on community attachment used community participation, social and cultural environment as major dependent variables, however, both independent variables and dependent variables were used interchangeably in many cases. 3) Recent studied on community attachment employed community economic and cultural variables, however, studies on community attachment in Korea was relatively limited in terms of quantity as well as quality. 4) Further research on community attachment should be conducted by utilizing various independent and dependent variables in various communities to increase the community attachment in rural and urban communities to further strengthen community development in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.95-98
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• 1996

Universal Learning Network(U.L.N.), which can model and control the large scale complicated systems naturally, consists of nonlinearly operated nodes and multi-branches that may have arbitrary time delays including zero or minus ones. Therefore, U.L.N. can be applied to many kinds of systems which are difficult to be expressed by ordinary first order difference equations with one sampling time delay. It has been already reported that learning algorithm of parameter variables in U.L.N. by forward and backward propagation is useful for modeling, managing and controlling of the large scale complicated systems such as industrial plants, economic, social and life phenomena. But, in the previous learning algorithm of U.L.N., time delays between the nodes were fixed, in other words, criterion function of U.L.N. was improved by adjusting only parameter variables. In this paper, a new learning algorithm is proposed, where not only parameter variables but also time delays between the nodes can be adjusted. Because time delays are integral numbers, adjustment of time delays can be carried out by a kind of random search procedure which executes intensified and diversified search in a single framework.

• 한국의류학회지
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• 제20권3호
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• pp.502-511
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• 1996

While much research on brand loyalty have been conducted until now, little has been challenged to integrate the results of previous (studies and how the brand loyalty is developed. The purpose of this study was to) suggest and test the model of clothing brand loyalty formation via consideration of all related variables simultaneously using the LISREL. The subjects were 505 male and female college graduates or higher white collar workers in their twenties and thirties living in Seoul, Korea. The data were collected by self- administered questionnaires. The results showed that consumer knowledge, product involvement, and perceived risk are positively related to information search. However, the influence of perceived risk on information search is statistically insignificant. Product involvement is also positively related to consumer satisfaction. Information search and consumer satisfaction are positively related to brand loyalty, respectively. In conclusion, consumer knowledge, product involvement, and perceived risk have positive influences on brand loyalty through the mediating variables of information search and consumer satisfaction.

• 한국지반공학회논문집
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• 제25권9호
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• pp.93-100
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• 2009

본 연구에서 역해석에 이용한 직접법은 실제 변위와 목적함수의 차이를 최소화하고 미지변수를 보정하는 최적화가 핵심 과정이다. 연구과정이 복수의 지층을 단계별로 역해석하여 각 지반의 미지변수를 역해석하기 때문에 지층 간 미지변수의 간섭 효과를 최소화 할 수 있는 추가적인 최적화가 필요하다. 따라서 효율적이고 정확한 최적화를 위해서 목적함수의 편미분 계산과정이 없이 최적해를 구할 수 있는 직접탐색법(direct search method)을 사용하였다. 본 연구의 목적은 지하구조체가 포함된 지층을 상부와 하부의 지층으로 모형화하고, 다중 미지변수를 역해석하는 기법을 개발하는 데에 목적을 둔다. 또한 단계별 역해석된 미지변수의 상호 간섭 오차를 최소화하기 위해서 반복 역해석을 실시하고, 실제 존재하는 터널에 대하여 적용성에 대해 검토하였다. 그 결과, 단층 모형화보다 다층 모형화 결과가 실제 지하구조물거동을 정확히 나타냈으며 다층 경계부에 위치한 지하구조물의 다층지반 모형화를 통한 역해석이 유효함을 확인하였다.

• 대한가정학회지
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• 제32권5호
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• pp.67-82
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• 1994

The major purpose of this study was to find the influencing factors in explaining information search patterns and to find if significant differences exist in search outcomes by search patterns. The data for this study were collected in a survey conducted in March of 1993. The final sample consisted of 327 respondents purchased refrigerator 340 purchased bed. The important findings of this study are as follows: First The variables related to search cost-benefit play an important role in identifying search patterns of consumers. Second search outcomes were different among four information search patterns for each of information sources. The overall search outcomes the level of purchase knowledge and of post-purchase satisfaction was relatively high for high-search and high-reliance group compared with other groups. And the results also indicate that although some consumers search less than others they still can make good purchase decision-making and can maximize their utility if they choose useful information sources selectively and use those selected information sources effectively. The findings of this study provide some implications regarding consumer education programs the consumer information providing policies and future research methods.

• 한국생활과학회지
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• 제7권1호
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• pp.61-74
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• 1998

The purpose of this study is to investigate the information search, information use and search outcomes. 420 students in Chungnam and Taejon area were surveyed. Questionnaire survey method and multiple regression and path analysis were used. Some major conclusions were as follows: 1) The levels of the information search, information use and search outcomes were relatively low. 2) The volumes of information search and the contents of information were mainly affected by psycho-behavioral variables. 3) The level of information use was affected by the content of information, desire to seek information, involvement, and previous knowledge. 4) The search outcome was affected positively by the information use, involvement, volume of information search, desire to seek information, and perceived risk. 5) The volume of information search and the information use were the parameter of the search outcomes.

• 한국의류학회지
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• 제32권7호
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• pp.1046-1055
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• 2008

The purpose of this study is to investigate the effects of product variables(i.e., fashionability, brand fame) and situational variables(i.e., time constraint, usage occasion) on the internet browsing behavior (i.e., prepurchase search; ongoing search for products, stores, fashion trends, promotions, and post-purchasing information) for fashion products. This study developed hypothetical scenarios based on the factorial design of the two independent variables for the survey with a questionnaire. All items in the questionnaire were measured on a six-point scale. By convenience sampling and on-line survey, a total of 209 usable responses were used for further analyses. The results show as follows; firstly, respondents more intensively browse for information search on products, stores and fashion trends when the style of browsing products is trendy. Secondly, whether the fashion products have a famous brand name or not has a significant influence on browsing behavior for stores and fashion trends information search. Thirdly, time constraint is found to influence significantly on respondents' browsing for promotions information search. Lastly, occasion for product worn shows a significant influence on browsing behavior for stores and fashion trends information search. The managerial implications are provided based on findings.