• Journal of Computing Science and Engineering
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• 제1권2호
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• pp.177-194
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• 2007

Index selection is one of the most important decisions to take in the physical design of relational data warehouses. Indices reduce significantly the cost of processing complex OLAP queries, but require storage cost and induce maintenance overhead. Two main types of indices are available: mono-attribute indices (e.g., B-tree, bitmap, hash, etc.) and multi-attribute indices (join indices, bitmap join indices). To optimize star join queries characterized by joins between a large fact table and multiple dimension tables and selections on dimension tables, bitmap join indices are well adapted. They require less storage cost due to their binary representation. However, selecting these indices is a difficult task due to the exponential number of candidate attributes to be indexed. Most of approaches for index selection follow two main steps: (1) pruning the search space (i.e., reducing the number of candidate attributes) and (2) selecting indices using the pruned search space. In this paper, we first propose a data mining driven approach to prune the search space of bitmap join index selection problem. As opposed to an existing our technique that only uses frequency of attributes in queries as a pruning metric, our technique uses not only frequencies, but also other parameters such as the size of dimension tables involved in the indexing process, size of each dimension tuple, and page size on disk. We then define a greedy algorithm to select bitmap join indices that minimize processing cost and verify storage constraint. Finally, in order to evaluate the efficiency of our approach, we compare it with some existing techniques.

• 디지털융복합연구
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• 제18권11호
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• pp.465-475
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• 2020

본 연구의 목적은 e-스포츠 관련 유튜브 BJ 속성이 정보의 유용성과 정보탐색 만족도 및 행동 의도의 구조적관계를 규명하고자 한다. 이를 위하여 대학생들을 편의표집하여 수집된 229명의 자료를 최종분석에 사용하였으며, SPSS 23.0과 AMOS 23.0 프로그램을 이용하여 빈도분석, 타당성분석, 신뢰도분석, 상관관계 및 구조방정식모형분석하였다. 연구결과는 다음과 같이 첫째, BJ의 친밀성은 정보의 유용성, 정보탐색 만족도 및 행동 의도에 유의한 정(+)의 영향을 미쳤다. 둘째, BJ의 신뢰성은 정보의 유용성, 정보탐색 만족도 및 행동의도에 유의한 영향을 미치지 않는 것으로 나타났으며, 셋째, 정보의 유용성은 행동의도에 유의한 영향이 없지만 정보탐색 만족도는 행동 의도에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 이에 본 연구의 결과는 BJ의 주요 속성요인인 친밀성을 기반한 e-스포츠 콘텐츠 제작에 대한 전략 수립에 기여하며, 추후 다양한콘텐츠를 중심으로 BJ 및 관람자의 속성과 소비행동을 위한 비교연구가 필요할 것으로 사료된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.101.4-101
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• 2001

Evolutionary algorithm has been receiving a remarkable attention due to the model-free and population-based parallel search attributes and much successful results are coming out. However, there are some problems in most of the evolutionary algorithms. The critical one is that it takes much time or large generations to search the global optimum in case of the objective function with multimodality. Another problem is that it usually cannot search all the local optima because it pays great attention to the search of the global optimum. In addition, if the objective function has several global optima, it may be very difficult to search all the global optima due to the global characteristics of the selection methods. To cope with these problems, at first we propose a preprocessing process, grid-filtering algorithm(GFA), and propose a new distributed evolutionary ...

• 대한가정학회지
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• 제35권1호
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• pp.357-372
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• 1997

The purpose of this study was to 1) segment female adolescent consumers into consumer groups displaying different consumer decision-making styles 2) to determine the consumer characteristics(clothing involvement information search store patronage and demographic variables) that related to each consumer segment and 3) to identify the interrelationship between the consumer characteristics. Decision-making styles were measured by 32 seven-point Likert type scales adapted from Sproles & Kendall and Shim & Kot A total of 78 statements dealing with three aspects of consumer characteristics was adapted from previous research. Data were collected from 567 2nd grade female middle and high school students in Seoul via self-administered questionnaires. and were analysed by frequency factor analysis ANOVA cluster analysis χ2 -test and Duncan's multiple range test. The results of this study were as follows: As a results of cluster analysis and ANOVA on seven factors of desion-making styles(1. brand-consiousness 2. novelty/fashion-consciousness 3. recreational/hedonis-tic orientation, 4. impulsive/carelessness, 5. price-consciousness/value-for-money, 6. perfectionism/high quality orientation 7. habitual/brand-royal consciousness) three consumer groups were identified and labeled as puality-oriented/non-utlitarian shoppers price-oriented shoppers and apathetic shoppers. Quality-oriented/non-utilitarian shoppers showed the highest clothing involvement scores of all aspects the highest consumer knowledge/experience most active ongoing information search and prepurchase information search. They preferred department store and franchise store for apparel shopping and considered service/reliability atmosphere variety of goods as important store attributes, Price-oriented shoppers showed prepurchase information search and planned purchase behavior actively. They preferred factory outlet store specialty stre and considered price very important as store attributes. Apathetic shoppers showed the lowest scores of all aspects of clothing involvement and most passive behavior in information search activities except showing the highest planned purchase. They preferred regional markets.

• 대한교통학회지
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• 제26권1호
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• pp.145-153
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• 2008

기존의 최단경로 탐색모형들은 주로 경로의 단일 속성만을 고려한다. 그러나 실제로 통행자가 단일 속성만을 고려하여 경로를 선택하는 경우는 드물며, 대부분의 경로는 통행시간이나 경로길이 또는 통행자의 개인적인 선호 등과 같은 다양한 속성들이 종합적으로 고려되어 선택되어진다. 따라서 최적경로를 탐색하기 위해서는 이와 같은 다양한 속성들을 종합적으로 고려하여야 한다. 본 논문에서는 다양한 경로속성들을 고려하기 위하여 이산선택모형을 사용하여 네트워크의 노드별 효용을 산출하고, 이를 이용하여 최대의 효용을 가지는 경로를 탐색한다. 경로선택모형을 구축하기 위하여 경로선택에 영향을 미치는 요소들을 통행시간, 지체시간, 경로길이, 신호교차로수, 회전수, 전용도로의 포함비율 6가지로 선정하고, 모형의 모수를 추정하기 위한 현시선호자료를 구하기 위하여 서울시와 인접 신도시 간의 기종점 5개에 대한 경로를 선정하여 설문조사를 실시하였다. 경로선택모형의 함수형태로는 다항로짓모형을 사용하였으며, 모수추정 결과 통행시간과 신호 교차로수, 전용도로의 포함비율을 제외한 경로길이, 지체시간, 회전수를 가지고 모수를 추정한 결과가 통계적 유의성이 가장 높은 모형으로 도출되었다. 경로탐색 알고리즘으로는 도심부에서 U-turn과 회전제한의 반영이 가능한 기존의 수정형 덩굴망 알고리즘을 사용하였으며, 이를 구현하여 실제 네트워크에 적용하였다.

• 한국조리학회지
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• 제23권6호
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• pp.27-35
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• 2017

The purpose of this study was to examine the causal relationship among restaurant selection attributes and customer satisfaction and recommendation tastes for young people in their twenties who use tickets for Rail-ro. Data collection was conducted to utilize questionnaire survey with online and offline distribution. The collected data were analyzed using a statistical program SPSS 21.0 with frequency analysis, reliability analysis, factor analysis, and regression analysis. The results of the study showed that Internet search is the most common source of information about restaurants during the trip, and restaurant choice attributes have an important impact on customer satisfaction, food quality, employee service and reputation, but hygiene did not have a big effect on customer satisfaction. In addition, customer satisfaction has a significant effect on recommendation intention. Concluding the results from this study, it investigated the significant attributes for customers selection of restaurants and provide meaningful advice for market managers to make useful marketing strategies to attract more clients and augment economic benefits.

• 품질경영학회지
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• 제47권2호
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• pp.237-254
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• 2019

Purpose: The purpose of this study is to analyze correlation of perceived cosmetics brand apps attributes and use intentions, mediating role of customer satisfaction, and relationship between customer satisfaction and continuous usage intention. Then provide basic data for development management strategy of beauty industry and enhancement of competitiveness corresponding to smart era. Methods: The questionnaires were surveyed by an online company(EMBRAIN). After data collection, frequency analysis was performed on the general attributes of questionnaire survey using SPSS 22.0, and data conclusions were derived by verifying reliability and validity of data and hypotheses. Results: First, perceived cosmetic brand app attributes have a positive effect on customer satisfaction, Second, perceived cosmetic brand app attributes have a positive effect on continuous usage intention. Third, customer satisfaction was found to have a mediating role in the effect of perceived cosmetic brand app attributes on continuous usage intention. Fourth, involvement proved to control the relationship between perceived cosmetic brand app attributes perceived interactivity and customer satisfaction. Finally, Involvement has proven to control the relationship between cosmetic brand app attributes perceived interactivity and continuous usage intention. Conclusion: Consumers buying products from cosmetics brand apps will be more likely to use cosmetics brand apps if they feel comfortable with calculation process, search, booking confirmation and payment methods.

• Child Health Nursing Research
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• 제23권1호
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• pp.28-36
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• 2017

Purpose: This paper is a report on the concept analysis of family-centered care for hospitalized children. Methods: The concept analysis approach of Walker and Avant was used. A search of multidisciplinary literature published between 1960 and 2016 was undertaken using the keyword 'family centered care' or 'family centered nursing' combined with hospitalized children. Attributes, antecedents, and consequences were inductively derived from the citations analyzed (n=19). Results: The attributes of family-centered care included (1) family respect, (2) collaboration, (3) family support, and (4) information sharing. These attributes are influenced by the 'willingness of family to participate', 'competency and willingness of staff,' and 'institution policy and system.' Additionally, family-centered care does significantly impact 'the health of the children', 'family empowerment' and 'work satisfaction and self-confidence of staff'. Conclusion: Family-centered care of hospitalized children as defined by the result of this study will contribute to the theoretical foundation for application in pediatric nursing practice.

• Spatial Information Research
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• 제5권2호
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• pp.195-198
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• 1997

WEB기반의 환경 GIS자료 관리를 위해 JVM, JDBC, Oracle DB을 이용한다. 본 논문에서의 다루는 환경 GIS자료에는 위성, 주제도, GIS자료 등이 있으며, 이 자료는 공간 정보와 속성 정보를 가지고 DB에 존재한다. 자료의 검색은 WEB Broswer의 조회용 지도를 이용한 공간 검색과 비공간 속성 정보에 의한 검색 기능을 제공한다. 자료 등록은 WEB Broswer에서 자료 등록 시스템을 이용한다.

• 산업기술연구
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• 제20권B호
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• pp.219-226
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• 2000

In this paper, we propose a new novel method for similarity search that supports time warping. Our primary goal is to innovate on search performance in large databases without false dismissal. To attain this goal, we devise a new distance function $D_{tw-lb}$ that consistently underestimates the time warping distance and also satisfies the triangular inequality. $D_{tw-lb}$ uses a 4-tuple feature vector extracted from each sequence and is invariant to time warping. For efficient processing, we employ a multidimensional index that uses the 4-tuple feature vector as indexing attributes and $D_{tw-lb}$ as a distance function. We prove that our method does not incur false dismissal. To verify the superiority of our method, we perform extensive experiments. The results reveal that our method achieves significant speedup up to 43 times with real-world S&P 500 stock data.