• Journal of Korea Port Economic Association
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• v.33 no.4
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• pp.99-116
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• 2017

This paper analyzes the characteristics of change in economic indicators logistics business performance indicators in Japan over the past decade. We compare the differences in management performance of groups related to logistics business strategy. This is because we want to show that the logistics business strategy is reflected in the management performance. Research methods include correlation analysis, crossover analysis, and variance analysis. The main results are as follows. First, logistic companies' sales are highly correlated with economic indicators such as GDP, trade value, and stock price. Second, there is a correlation between the business sectors and the proportion of tangible assets. It is understood that different business strategies are appropriate for each industry and each period. Third, the effects of business strategy variables on business performance variables were significant. In particular, the interaction effect of three variables showed a difference in the effect on the yield. The results of this study provide a better understanding of how logistics companies achieve a high performance in the changing economic environment over the past decade.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.11a
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• pp.502-509
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• 2002

Maximal Covering 문제(MCP)란 행렬 상에서 n개의 열(column) 중 p개를 선택하여 m개의 행(row)중 최대한 많은 행을 cover하는 문제로 정의된다. 본 논문에서는 MCP를 유전 알고리즘(Genetic Algorithm)으로 해결하기 위해 문제에 적합하게 설계된 교차 연산자(crossover operator)와 비발현 유전인잔(unexpressed gene)를 가진 새로운 염색체 구조를 제시한다. 해결하고자 하는 대상 MCP의 규모가 매우 큰 경우 전통적인 임의교차(random crossover) 방법으로는 좋은 결과를 얻기가 힘들다. 따라서 본 연구에서는 그리디 교차(greedy crossover) 방법을 제시하여 문제를 해결한다. 그러나 이러한 그리디 교차를 사용하더라도 조기 수렴 등의 문제로 인해 타부 탐색 등의 이웃해 탐색 방법에 비해 그리 좋은 결과를 얻기가 힘들다. 본 논문은 이러한 조기 수렴 문제를 해결하고 다른 이웃에 탐색 방법보다 더 좋은 결과를 얻기 위해 비발현 유전인자(unexpressed gene)를 가진 염색체를 도입하여 해결함을 특징으로 한다. 비발현 유전인자는 교차 과정에서 자식 염색체의 유전인자로 전달되지 않은 정보 중 나중에라도 유용할 가능성이 보이는 정보를 보존하는 역할을 하여 조기 수렴 문제를 해결하는데 도움을 주어 보다 나은 결과를 얻을 수 있게 해준다. 대규모 MCP를 해결하는 실험에서 새로운 비발현 유전인자를 적용한 유전 알고리즘이 기존의 유전 알고리즘뿐만 아니라 다른 탐색 기법에 비해 더욱 좋은 성능을 보여줌을 확인하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.69-74
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• 2011

In this paper, we propose a foot-and-mouth disease prevention system using the RTLS technology and $A^*$ algorithm-based optimal path search method to avoid foot-and-mouth disease areas. The main features and contributions of the proposed system are as follows. First, the proposed system is developed based on active-tag for identifying status and location information of livestock. Second, the system is newly designed based on $A^*$ algorithm for supporting optimal path search services. The performance evaluation of the proposed system is performed via simulation. The results of performance evaluation show that the proposed system can efficiently support the optimal path search services.

• Journal of Internet Computing and Services
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• v.23 no.2
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• pp.61-70
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• 2022

General users who use smartphone apps often use the Vault app to protect personal information such as photos and videos owned by individuals. However, there are increasing cases of criminals using the Vault app function for anti-forensic purposes to hide illegal videos. These apps are one of the apps registered on Google Play. This paper proposes a methodology for extracting feature points through XML-based keyword frequency analysis to explore Vault apps used by criminals, and text mining techniques are applied to extract feature points. In this paper, XML syntax was compared and analyzed using strings.xml files included in the app for 15 hidden Vault anti-forensics apps and non-hidden Vault apps, respectively. In hidden Vault anti-forensics apps, more hidden-related words are found at a higher frequency in the first and second rounds of terminology processing. Unlike most conventional methods of static analysis of APK files from an engineering point of view, this paper is meaningful in that it approached from a humanities and sociological point of view to find a feature of classifying anti-forensics apps. In conclusion, applying text mining techniques through XML parsing can be used as basic data for exploring hidden Vault anti-forensics apps.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.3
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• pp.251-270
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• 2012

Multimedia needs and searching have become important in everyday life, especially in a younger generation. The characteristics of multimedia needs and searching behaviors are distinctive compared to textual information needs and searching behaviors in a wide variety of ways. By interviewing and observing multimedia needs and searching behaviors of college students from 20 areas in Seoul, this study aims to improve the understanding on users' multimedia needs and how users search multimedia. The findings are presented in terms of searching sources, multimedia needs, relevance criteria and searching barriers. For multimedia, the searching sources are found primarily as Naver and Google and the distinguished features are presented depending on the individual multimedia types. As multimedia needs are categorized into generic, specific and abstract, most of the needs are classified as specific needs rather than generic needs, but there exist differences depending on the types of multimedia. In addition, the aspects of relevance criteria and searching barriers are reflected with the characteristics of individual multimedia types. The findings of this study demonstrate that distinctive indexing and searching environments depending on the types of multimedia might be necessary to improve the quality of multimedia searching.

• 한국벤처창업학회:학술대회논문집
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• 2017.04a
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• pp.50-50
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• 2017

최근의 사회경제적 변화는 그 속도가 빨라짐과 동시에 불학실성이 극도로 높아짐에 따라, 대기업을 비롯하여 과거 큰 성장을 이루어왔던 기성기업들의 기존 사업 강화와 미래 성장동력 확보가 더욱 어려운 현실이 되었다. 이러한 불확실성이 높은 기업환경에서 내부 시스템에만 의존적인 전략으로는 한계가 명확하여, 기업들이 외부의 자원을 활용하여 내부적인 대규모 투자 위험을 줄이고 신규사업의 불확실성에 대처하는 개방형 혁신전략이 필수적으로 받아들여져 왔다. 이러한 개방적 혁신 전략의 중요한 수단으로서 CVC(Corporate Venture Capital)는 그동안 미국을 중심으로 40여년간 활발히 활용되어 왔고 학문적 연구 대상으로 자리 잡았으나, 한국에서는 극히 일부 기업을 통해서만 전략적으로 운영되어 왔고 그 구분도 명확하지 않아 CVC에 대한 연구가 상당히 미약한 실정이다. 본 연구에서는 국내외의 기존 연구 결과들을 분석하여 CVC에 대한 정의와 운영상 특징에 대하여 살펴보고, CVC가 운영 기업 및 벤처기업의 기술혁신과 가치제고에 미치는 제반 조건들의 분석을 통하여 CVC가 성공적인 양방향적 성과도출을 만드는 최적의 모델을 도출하여 보았다. CVC는 첫째, 불확실성이 높은 산업에 속한 기업들간의 투자관계가 성립될 때, 둘째, 설립 시 전략적인 포커스가 명확할 때, 셋째, 모기업이 영위하는 산업과 같은 분야에 속한 벤처기업들에 투자하며 동시에 서로가 공유 할 보완적 자산이 존재할 때, 마지막으로, 금융적 성과에 대해서 해당 매니저에 대한 성과보상을 일반 벤처캐피탈과 동일하게 지급할 때 가장 성공적인 성과를 만들어 낼 수 있음을 알 수 있었다. 이를 통해 도출된 시사점들을 바탕으로 더 많은 기성기업들이 성공적으로 CVC를 운영한다면, 신성장동력 확보와 대기업-벤처기업간 상생혁신을 이룰 수 있을 뿐만 아니라, 창업문화 확산에도 기여를 할 수 있을 것으로 기대 한다.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.155-169
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• 2021

This study aims at exploring the features of science teaching orientation (STO) and its relationships with other PCK (pedagogical content knowledge) components. To do this, based on the definition of STO by Friedrichsen, Driel, & Abell(2011) and PCK model by Magnusson, Krajcik, & Borko(1999), we observed one experienced elementary teacher's science lessons for 21 lesson hours (10 hours of 'Motion of Objects' and 11 hours of 'Light and Lens') and carried out qualitative analyses of the data obtained from lessons observation, teacher interviews, and CoRe (content representation) responses. We analyzed the teacher's three aspects of STO (i.e. beliefs about the goals and purpose of science teaching, beliefs about the nature of science, and beliefs about science teaching and learning) which can converge into an overall STO of 'inquiry'. And these aspects of STO appear to interact differently with four PCK components (i.e. curriculum knowledge, learner knowledge, instructional knowledge, and assessment knowledge) depending on the topic of the lesson. It is hoped that this in-depth understanding of the features of STO and its relationship with other PCK components would provide useful information on how to monitor and improve STO and PCK of elementary teachers.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.209-220
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• 2004

The main feature of H.264 standard against conventional video standards is the high coding efficiency and the network friendliness. In spite of these outstanding features, it is not easy to implement H.264 codec as a real-time system due to its high requirement of memory bandwidth and intensive computation. Although the variable block size motion compensation using multiple reference frames is one of the key coding tools to bring about its main performance gain, it demands substantial computational complexity due to SAD (Sum of Absolute Difference) calculation among all possible combinations of coding modes to find the best motion vector. For speedup of motion estimation process, therefore, this paper proposes fast algorithms for both integer-pel and fractional-pel motion search. Since many conventional fast integer-pel motion estimation algorithms are not suitable for H.264 having variable motion block sizes, we propose the motion field adaptive search using the hierarchical block structure based on the diamond search applicable to variable motion block sizes. Besides, we also propose fast fractional-pel motion search using small diamond search centered by predictive motion vector based on statistical characteristic of motion vector.

• The Journal of the Korea Contents Association
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• v.3 no.1
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• pp.9-13
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• 2003

We propose a block motion estimation algorithm based on a statistical image feature for video sequences. The statistical feature of the reference block is obtained, then applied to select the candidate starting points (SPs) in the regular starting points pattern (SPP) by comparing the statistical feature of reference block with that of blocks which are spread ower regular SPP. The final SPs are obtained by their Mean Absolute Difference(MAD) value among the candidate SPs. Finally, one of conventional fast search algorithms, such as BRGDS, DS, and three-step search (TSS), has been applied to generate the motion vector of reference block using the final SPs as its starting points. The experimental results showed that the starting points from fine SPs were as dose as to the global minimum as we expected.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.443-449
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• 2017

Swarm of low-cost UAVs for search mission has benefit in the sense of rapid search compared to use of single high-end UAV. As the number of UAVs forming swarm increases, not only the time for the mission planning increases, but also the system to operate UAVs has excessive burden. This paper addresses a decentralized area search algorithm adequate for multiple UAVs which takes advantages of flexibility, robustness, and simplicity. To down the cost, it is assumed that each UAV has limited ability: close-communication, basic calculation, and limited memory. In close-communication, heath conditions and search information are shared. And collision avoidance and consensus of next search direction are then done. To increase weight on un-searched area and to provide overlapped search, the score function is introduced. Performance and operational characteristics of the proposed search algorithm and mission planning logic are verified via numerical simulations.