• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권5호
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• pp.888-908
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• 2011

The increasing demand from passengers in vehicles to improve safety, traffic efficiency, and comfort has lead to the growing interest of Wi-Fi based vehicle-to-infrastructure (V2I) communications. Although the V2I system provides fast and cost-effective Internet connectivity to vehicles via roadside Wi-Fi access points (APs), it suffers from frequent handoffs due to the high mobility of vehicles and the limited coverage of Wi-Fi APs. Recently, the Mobile AP (MAP) platform has emerged as a promising solution that overcomes the problem in the V2I systems. The main advantage is that MAPs may yield longer service duration to the nearby vehicles that have similar mobility patterns, yet they provide smaller link capacities than the roadside APs. In this paper, we present a new association control technique that harnesses available connection duration as well as achievable link bandwidth in high-speed vehicular network environments. We also analyze the tradeoff between two association metrics, namely, available connection duration and achievable link bandwidth. Extensive simulation studies based on real traces demonstrate that our scheme significantly outperforms the previous methods.

• 대한기계학회논문집B
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• 제24권8호
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• pp.1029-1037
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• 2000

The present study investigates the local heat/mass transfer characteristics on a rotating disk which is the top disk covered with a shroud in HDD. The naphthalene sublimation technique is employed to determine the local heat/mass transfer coefficients on the rotating disk. Flow field measurements using Laser Doppler Anemometry (LDA) and numerical calculations are performed to analyze the flow patterns induced by the disk rotation. HDD has been developed for compactness and speedy data access, thus the rotating velocity of the disk is increased and the height of a hub is decreased. The experiments are conducted for the various hub heights of 5, 10 and 15 mm, for the rotating Reynolds numbers of $5.5{\times}10^4$ to $1.1{\times}10^5$ and for the effects of the presence of a read/write head arm. The results show that the heat transfer on the rotating disk is enhanced considerably for the decrease of the hub height and for the increase of the rotating Reynolds number. The head arm inserted in the cavity decreases the heat transfer despite the enhancement of tangential RMS velocity because of the deficit of the momentum in the flow field.

• International Journal of Contents
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• 제6권3호
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• pp.10-14
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• 2010

Researchers in Korea and elsewhere have carried out a wide variety of important research activities in their respective fields, producing valuable research results. For such diverse research results to be shared and exchanged among researchers working in the same discipline and research subject there needs to be a community environment based on free utilization of information. Against this backdrop, this study seeks to classify and reprocess the reference/factual content owned by the KISTI (Korea Institute of Science and Technology Information), a state-run distributor of information on science and technology, by the different research subjects. It also seeks to develop and provide a community model based on the concepts of open archiving and open access for the researchers specialized in the related fields of research. This community model is developed focusing on the research results from the field of bioscience, where the most extensive studies are currently being conducted. To develop the community model, this study: (a) surveys the current status of the content owned by KISTI; (b) analyzes the patterns and characteristics of biological scientific content among the KISTI-owned content; and (c) designs a web platform where researchers can freely upload/download research results.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2013년도 춘계 종합학술대회 논문집
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• pp.11-12
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• 2013

최근 대규모 데이터의 처리와 관리를 위한 분산 저장 및 처리 시스템의 연구 및 활용이 중요해지고 있다. 대표적인 분산 저장 및 처리시스템으로써 하둡(Hadoop)이 널리 활용되고 있다. 하둡 분산 파일 시스템을 기반으로 수행되는 맵-리듀스에서 테스크 할당은 데이터의 로컬리티를 고려하여 최대한 가깝게 할당한다. 하지만 맵-리듀스에서의 데이터 분석 작업에서 작업 형태에 따라 빈번하게 요청되는 데이터가 존재한다. 이러한 경우, 해당 데이터의 낮은 로컬리티로 인해 수행시간 증가 및 데이터 전송의 지연의 문제점을 야기 시킨다. 본 논문에서는 맵-리듀스의 처리 속도 향상을 위한 데이터 접근 패턴에 따른 핫-데이터 복제 기법을 제안한다. 제안하는 기법에서는 데이터 접근 패턴에 따라 높은 접근 빈도를 보이는 핫-데이터에 대한 복제본 최적화 알고리즘을 활용하여 데이터 로컬리티를 향상시키고 결과적으로 작업 수행시간을 감소시킨다. 제안하는 기법은 기존 기법에 비해 모든 노드의 데이터 이동이 감소하여 접근빈도의 분포가 균형적인 것을 확인하였다. 성능평가 결과, 기존 기법에 비해 접근 빈도의 부하가 약 8% 감소하는 것을 확인하였다.

• Journal of Plant Biology
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• 제39권1호
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• pp.49-55
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• 1996

본 연구는 마늘(Allium sativum L.)의 기초적인 유전적 특성을 파악하기 위해, 단양마늘을 대상으로 염색체 DNA의 반복서열의 양상을 확인하고, 고반복서열이 매우 빠르게 reassociation되는 특성을 이용하여 이들에 해당되는 부분을 분리하고, 클로닝하였다. 이들 고반복서열 클론의 게놈 내의 copy수는 대체적으로 $10^{5}~10^{7}$이었다. 이 중 일부 클론의 염기서열과 분석한 결과, G/C 함량은 25~40% 정도로 낮았고, 일부서열의 내부에서는 소단위의 염기서열이 반복배열되어 있었다. 단양을 비롯한 문경, 서산, 의성 품종 사이에서 해당 반복서열의 변이정도를 조사하기 위하여, 다섯종류의 고반복서열을 탐침으로 이들 품종 마늘에 대한 RELP(restriction fragment length polymorphism)분석을 한 결과 이들 서열의 유전적변이는 거의 나타나지 않았다.

• 산업경영시스템학회지
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• 제41권3호
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• pp.170-175
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• 2018

While the term online shopping refers to all online transactions, cross-border online shopping means shopping activities purchasing products or services over the internet for the customers abroad. As Internet use for the international shopping activity increasing, cross border online shopping has grown substantially for last decade. This study is about the problem regarding the cross border online shopping for two different countries and the variables that influence their shopping behavior. The cross border online shopping has been increased by the growth of Internet access. However, the growth of the Internet use does not guarantee a successful development of cross border e-commerce for every country. To find out the perception for cross-border online shopping for two different cultures, shoppers from two countries with different cultural background were chosen, and the perception for cross-border online shopping from each culture is contrasted. For statistical Analysis, ANOVA is used to find the relationship between a single non-metric independent variable, and multiple metric dependent variables. Hofstede's cultural dimensions model is adopted for this study as a tool to find out the patterns of cross border online shopping. This study showed what the variables would affect the perception in cross border online shopping. The results of this study indicated that cross border online shoppers with different culture were notably different on two variables identified-timeliness and ease of use.

• Child Studies in Asia-Pacific Contexts
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• 제3권2호
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• pp.123-137
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• 2013

Individuals rely on Theory of Mind (ToM) to represent themselves, others, and socio-cultural norms. Distinctive Western and Eastern developmental patterns of ToM have been reported in monocultural children. Relatively little is known about bicultural children, especially those children who grow up in two conflicting and unbalanced cultures. We hypothesized that the development of ToM in these bicultural preschoolers would follow the pattern of the dominant culture. To examine this hypothesis, we recruited English-speaking Chinese Singaporean preschoolers. In Study 1, we tested 3- to 5-year-olds (N = 120) with 5 ToM tasks, including diverse desires, diverse beliefs, knowledge access, and false belief, as well as a vocabulary task. In Study 2, we tested 5-year-olds (N = 30) with a picture-choice version of these ToM tasks. Both studies supported our hypothesis by revealing that the development of ToM in these bicultural children followed the pattern of the dominant culture. Additionally, we found that 5-year-old bicultural children are still developing false belief, and their verbal ability correlated with their ToM.

• Journal of Korean Biological Nursing Science
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• 제18권3호
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• pp.144-152
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• 2016

Purpose: This study compares beneficiaries of Korean Medicaid with those under the National Health Insurance program, seeking to understand how each group utilizes their healthcare. Methods: Data were obtained from a Health Promotion Survey in 2005. Health status was measured by the respondents' perception of health. Health service utilization included the availability of healthcare services, the type of healthcare institution, and intent to revisit. Predisposing and enabling factors, as well as health care needs were used for this study. Results: Compared to National Health Insurance beneficiaries, Medicaid beneficiaries reported lower levels of health status and fewer enabling factors. They had more chronic diseases and disabilities. Education level, existence of chronic diseases, exercise patterns, and disabilities were associated with health status. Conclusion: We found that Medicaid beneficiaries had fewer resources and higher levels of health needs. As Medicaid is reformed, policy makers and administrators should understand healthcare utilization behaviors of Medicaid beneficiaries and the factors hindering access to care.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.797-799
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• 2016

현재까지 제작된 아케이드 슈팅 게임은 진행할수록 급격히 지루해지는 미사일 패턴과 어려워지는 난이도로 인하여 접하는 사람들에게 높은 진입 장벽으로 작용되어왔다. 이러한 단점들을 보완하여 슈팅게임에 음악적 요소와 시간 감속 기능으로 게임 플레이를 사용자에게 유리하고 유쾌한 환경으로 만들어 사용자들이 쉽게 즐길 수 있는 리듬 슈팅 게임을 개발하였다.

• 한국컴퓨터정보학회논문지
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• 제23권10호
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• pp.1-9
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• 2018

Modern graphics processing units (GPUs) have become one of the most attractive platforms in exploiting high thread level parallelism with the support of new programming tools such as CUDA and OpenCL. Recent GPUs has applied cache hierarchy to support irregular memory access patterns; however, L1 data cache (L1D) exhibits poor efficiency in the GPU. This paper shows that the L1D does not always positively affect the applications in terms of performance and energy efficiency for the GPU. The performance of the GPU is even harmed by using the L1D for lots of applications. Our proposed technique exploits the characteristics of the currently-executed applications to predict the performance impact of the L1D on the GPU and then decides whether to continuously use the cache for the application or not. Our experimental results show that the proposed technique improves the GPU performance by 9.4% and saves up to 52.1% of the power consumption in the L1D.