• Journal of KIISE:Computing Practices and Letters
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• v.6 no.1
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• pp.36-44
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• 2000

In this paper, we describe the developing of a tool which supports both multimedia presentation with user's participation through a high speed network and authoring of various media using a single authoring tool. To support real-time synchronous multimedia presentation, we adopt dynamic synchronization method and adaptive transmission algorithm for synchronizing data transfer rate between sender and receiver using buffer management algorithm based on QoS parameters. And we also allow user's participation in the presentation using TRSG(Temporal Relationship Specification Graph) model. Finally, the proposed tool supports the minimal level of QoS and its continuous play-out using event auditing threads which control the current state of a multimedia presentation continuously by monitoring of negative factors effecting on QoS, and synchronization.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.9
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• pp.461-468
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• 2001

Though shared virtual memory (SVM) system promise low cost solutions for high performance computing they suffer from long memory latencies. These latencies are usually caused by repetitive invalidations on shared data. Since shared data are accessed through synchronization and the patterns by which threads synchronizes are repetitive, a prefetching scheme bases on such repetitiveness would reduce memory latencies. Based on this observation, we propose a prefetching technique which predicts future access behavior by analyzing access history per synchronization variable. Our technique was evaluated on an 8-node SVM system using the SPLASH-2 benchmark. The results show the our technique could achieve 34%~45% reduction in memory access latencies.

• 한국체육학회지인문사회과학편
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• v.55 no.5
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• pp.43-55
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• 2016

The purpose of this study is to verify analysis of self-efficacy and self-confidence of the athletes. The subjects of this study were selected 200 athletes who have a highschool athletes in Seoul. The data-collecting method use of self-confidence by Kim(1999) and self-efficacy by Kim(2002) & Lee(2003). The Descriptive Statistical Analysis Correlation Analysis and Regression Analysis As a result, Frist, family interest, motivation, mentor & hobby which is sport-state/trait affected confidence. Second, family interest, motivation, mentor & hobby which is affected self-efficacy. Third, sport-trait confidence which is affected self-efficacy.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.640-648
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• 2018

Time division wireless communication in tactical MANET is attractive to deliver both high data rates and long-range coverage, and to provide scheduled QoS to mission participants. This paper is about the time synchronization issue of multi-mission USV in tactical MANET. As USV communication coverage becomes longer, the synchronization error also becomes higher; therefore, which results in link disconnection, and consequent failures of reconnection because base station cannot configure necessary parameters over long-distant terminal. We propose a range adaptive time synchronization method to compensate for synchronization errors. The issue of long-range time synchronization problem was identified during maritime communication tests, and we verified the proposed method through analyses of both indoor and outdoor test results.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.2
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• pp.125-138
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• 2020

One of the most important steps to consider in utilizing micro-satellites for surveillance or reconnaissance operations is the design of the satellite constellation. The Walker-Delta constellation which is commonly used in designing satellite constellations is not ideal for this operation in which military satellites are required to monitor specific regions continuously in a stable manner. This study aims to discuss the methodology for designing a satellite constellation that is capable of monitoring the fixed region at the fixed time each day by using the Sun synchronous Orbit. The BB(Beach Ball) constellation that we propose outperforms the Walker-Delta constellation in terms of robustness and it holds the merit of being simple in its design, thereby making future expansions more convenient. We expect the BB constellation will have a high applicability as the operational concept of military surveillance satellites is established in the near future.

• Journal of Agricultural Extension & Community Development
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• v.26 no.1
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• pp.17-30
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• 2019

Tourism motivation and involvement are important variables influencing visitors satisfaction. The study aims to identify the factors influencing visitors' satisfaction. Particularly, the study examine the moderating effects on tourism involvement between tourism motivation and visitors' satisfaction. Data were collected from 430 usable questionnaires among visitors of Gigisi local festival. Results of a factor analysis yielded three dimensions of tourism motivation which are family and local food, recreation and escape, and social factor. Results show that social factors among three dimensions of sense of community have significance for visitors satisfaction. And tourism involvement has a negative interactional effects as a moderator between recreation and escape motivation and involvement. It means that even though higher recreation and escape motivation, less likely to have visitors satisfaction if visitors have higher involvement in local festival. It was suggested that tourism motivation and involvement should be considered in local festival management and policy.

• Journal of Agricultural Extension & Community Development
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• v.29 no.3
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• pp.155-172
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• 2022

Ecotourism as a alternative tourism destination has to adapt to current market mechanisms, which is becoming extremely competitive and which are dominated by communication and promotion strategies and techniques. We need to know the causative factors and influences by which tourists are motivated to become included in various market segments. The primary purpose of this study is to segment and profile the motivations of ecotourist, so as to enable a better understanding of ecotourism in Korea. A self-administered survey was collected from 200 tourists in the study area. A factor-clustering method identified four distinct segments: want-it-all seeker, passive seeker, aesthetic seeker, value sharing seeker. We conclude by considering the relevant of our findings to ongoing discussions of ecotourists' market segmentation.

• Journal of The Korean Association For Science Education
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• v.33 no.1
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• pp.17-29
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• 2013

High school 'science' in the 2009 revised curriculum in Korea was developed for the purpose of enhancing students' scientific literacy needed for citizenship in a democratic society. For this analysis, 'science' includes a variety of scientific topics from the origin of the universe to the birth of life, and the relationship between technology and modern society. It aims to make students understand the process of scientific inquiry and foster interest and curiosity about science. On the other hand, interest has been studied as a psychological construct to affect academic achievement and career selection of students. In this study, the authors investigated students' interest in high school 'science' in view of the 2009 revised curriculum. To carry this out, a survey tool was developed according to previous research, with 997 high school students' responses analyzed with descriptive statistics and factor analysis. The result showed that the students' interest in high school 'science' in view of the 2009 revised curriculum can be interpreted into three dimensions such as motivation, activity, and topic, which has several sub-dimensions. Students' interest in motivation dimension was higher than in activity or topic dimension, while the average value was slightly higher than the middle value. They showed different distribution of interest by gender and job orientation, especially in activity and topic dimensions. From this study, the authors can infer the multi-dimensional property of students' interest in high school 'Science' and the different distribution of interest by dimensions.

• Journal of The Korean Association For Science Education
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• v.32 no.5
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• pp.890-902
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• 2012

This study intended to analyze science-arts integration activities in science textbook and explore the artistic elements of science-art integrated activities. For this purpose, we selected science-arts integration activities in elementary science textbooks of Korea by revised curriculum in 2007. We analyzed them by the type, the function and the role of arts. The analysis of artistic element was based on 'design element' suggested by Baron & Eisner. Results revealed that the science-arts integration activities were using a visual art form than any other and the role of arts was mainly to apply science concepts. Through the artistic element analysis, we found that most activities were emphasized on 'empathic understanding' category than other categories. Based on the results, science-arts integration activities with more diverse form of art should be developed. Also the artistic element should be considered in developing future science-arts integration activities.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.331-339
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• 2002

This paper presents a garbage collection protocol for checkpoints and message logs which are staved on the stable storage or volatile storage for fault tolerancy. The previous works of garbage collections in coordinated checkpointing protocol delete all the checkpoints except for the last checkpoints on earth processes. But implemented in top of reliable communication protocol like as TCP/IP, rollback recovery protocol based on only last checkpoints makes sympathetic rollback. We show that the old checkpoints or message logs except for the last checkpoints have to be preserved in order to replay the lost message. And we define the conditions for garbage collection of checkpoints and message logs for lost messages and present the garbage collection algorithm for checkpoints and message logs in coordinated checkpointing protocol. Since the proposed algorithm uses process information for lost message piggybacked with messages, the additional messages for garbage collection is not required The proposed garbage collection algorithm makes 'the lazy garbage collectioneffect', because relying on the piggybacked checked checkpoint information in send/receive message. But 'the lazy garbage collection effect'does not break the consistency of the whole systems.