• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.736-738
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• 2001

웹을 사용하는 사용자들의 급속도로 증가하는 서비스 요청을 신속하고 저렴한 비용으로 처리하기 위한 대응책으로, LAN 환경의 웹 서버 클러스터 구조가 각광을 받고 있다. 높은 가용성 및 확장성을 보장하는 웹 서비스를 제공하기 위해 많은 부하의 서비스 요구를 여러 서버에게 효과적으로 나누어 처리할 수 있어야 하며, 따라서 서비스 요청 패킷을 고르게 분배할 수 있는 합리적인 스케줄링 기법을 필요로 한다. ONE-IP 스케줄링 기법은 이더넷의 브로드케스트 메시지에 의해 스케줄링이 분산되도록 하는 전략을 사용함으로써, 클러스터에 유입되는 패킷의 집중화로 인해 발생할 수 있는 병목 현상(bottleneck)과 치명적인 오류(Single-point of Failure) 문제를 효과적으로 해결하였다. 그러나, 서비스를 요청하는 패킷의 발신지 주소만을 이용하는 단순한 패킷 스케줄링을 사용하기 때문에 클러스터를 구성하는 서버들 간의 부하 불균형을 가중시키며, 결과적으로 클러스터의 효율성을 저하시키는 문제점을 가지고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 RR ONE-IP 기법을 제안하였다. 제안한 기법은 서버에 할당되는 부하간에 불균형이 발생하는 문제점을 해결하기 위해 TCP 연결 단위의 스케줄링 전략을 사용하였으며, 서버의 부하 정보를 이용하지 않는 RR 스케줄링 기법을 도입함으로써, ONE-IP 기법의 장점을 그대로 유지하면서 보다 나은 부하의 균등한 분배로 시스템의 처리 능력을 향상시키도록 하였다. 또한, 실험을 수행한 결과 제안한 기법이 기존의 기법에 비해 평균 3.84%의 시스템의 성능 향상을 보였으며, 과부하 발생율에서는 평균 23.5%의 감소를 가져왔음을 보였다.우 단어 인식률이 43.21%인 반면 표제어간 음운변화 현상을 반영한 1-Best 사전의 경우 48.99%, Multi 사전의 경우 50.19%로 인식률이 5~6%정도 향상되었음을 볼 수 있었고, 수작업에 의한 표준발음사전의 단어 인식률 45.90% 보다도 약 3~4% 좋은 성능을 보였다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아이에서 그 주산기사망률(周産基死亡率)

• Journal of the Economic Geographical Society of Korea
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• v.26 no.3
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• pp.202-222
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• 2023

This study traces the growth and changes in the spatial distribution and characteristics of media cluster in Seoul by focusing on the co-evolution of film and TV production. To identify the spatial distribution and aggregation of film and broadcast TV production, we measure their spatial auto-correlation based on Moran's I and LISA, using the data from the Census on Establishments of the National Statistical Office. In addition, the eleven semi-structured interviews conducted with workers in the media industries, such as film crews and TV drama producers, help to clarify the complexity and dynamics of diverse factors that affect spatial distribution of media cluster. This multi-method study shows the increasing polycentricity of media cluster in the last decade. Gangnam, Mapo, Yeouido, Gangseo-Yeongdeungpo, and Seongsu have emerged as key hubs for media industries, particularly in light of changes in the transportation system and the real estate market. The finding indicates the co-evolution of film and broadcast TV production, demonstrating how the characteristics of the creative industry and metropolitan changes are intertwined with each other in shaping the geographical pattern of the media cluster.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.273-296
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• 2006

The purpose of this paper is to investigate the formation and characteristics of Gwangju photonics agglomeration as a new agglomeration with a new industry. Data used in this study are locally investigatedfirm related data and the result of questionnaire surveys. Major findings are as follows. First, in the viewpoint of policy, national government suggested the whole policy frameworks and financial support for the strategic industrial development. Regional government picked up and fostered the strategic industry. The initial support of the national government and role of regional government triggered the initial development of the agglomeration. Second, in the spatial perspective, Gwangju photonics agglomeration is based on the externalities of knowledge and technology as well as the input-output network within value chains of production. There is a possibility that Gwangju photonics agglomeration will be developed as an innovation cluster of knowledge-based economy in the future beyond a mere production base of photonics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1137-1146
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• 2006

Under this economic circumstance, the logistics firms located in port take better advantages than those in other areas. This study observed those firms with consciousness to which matters were affected a growth of the logistics IT firms. This study considered in terms of three factors which are an economic factor, a political factor and an internal-ability factor for the matters of logistics IT firms' success through the factor analysis. According to the factor analysis, subjective factor showed positive: (1) expanding market through the ideas and abilities, (2) internal relations and government support (3) capability of market identification and focusing on regional industrialization. As a result of the internal ability analysis, there were three positive matters such as (1) a factor of organization or human resource management, (2) relationship with consumer and resource and management ability for strategy, and (3) developing unique product, networking, suitable goods of regional industrialization. The external factor, through the factor analysis was trued out (1) a emerged political factor such as a support up venture, cluster composition, investing R&D and specialist training, (2) economic factor such as tax reduction, financial support, marketing collaboration renting office in a low price by regional government.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.6
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• pp.461-467
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• 2005

The role of university is expanded from the human resource provider to demand site. The mission is also changed as a entrepreneurs. There is increasing in the needs of the university and industry cooperation(UIC), but cultural difference also happened. To successfully cooperation, we have to consider stakeholder's perspective and the size of companies and universities. Through the best c luster of innovation, we can figure out the key success factors of the universities, researchers, and leaders, and suggest the new characters for successful UIC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7A
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• pp.709-716
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• 2006

본 논문에서는 무선 센서 네트워크의 다양한 응용 환경 및 상/하향 트래픽 스트림의 특성에 따라 유연하게 적용할 수 있는 새로운 매체접근제어 프로토콜을 제안한다. HiPERMAC(Hierarchically-Paired Evolutionary Radio MAC)이라고 불리는 제안 매체접근제어방식은 다양한 클러스터링 방식에 의하여 구축된 다 계층 (Hierarchical) 네트워크에서 별도의 대역 확산 전송방식이나 다수의 주파수 채널을 사용하지 않고, 단 2개의 시간 구간을 공간적으로 재활용하여 N 계층의 개별적인 통신이 가능한 구조를 제공한다. 즉, 제안방식은 단일 주파수 개념을 이용하여 계층화된 우선 센서 네트워크를 계층적 이중화(Hierarchically-Paired)하고 이때 발생하는 클러스터 간 상호 간섭의 요인들을 시간 및 공간적으로 분리하여 망 확장성과 자원 효율성을 극대화 하는 새로운 매체접근 제어 방식 이다.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.4
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• pp.567-584
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• 2013

This study aims to explore an evolutionary path of the IT service industry in Fairfax County using the Cluster Adaptive Cycle model in economic geography. The analysis is based on detailed historical and industrial information obtained through a variety of data sources including local archival materials, economic census, and interviews. This study also performs a shift-share analysis during the period of 1990 to 2011. Using the adaptive cycle model, the local IT service industry is indicated by a trajectory of constant cluster mutation. The evolution of the local IT service industry has been closely related to federal government policy due to the regional specificity of the National Capital Region and the proximity of the Department of Defense. Although the economic downturn of the late 2000s, the local IT service industry has been notable resilience and adapted to a changing market and technological environment. This constant mutation of the local industry is resulted from not only high resilience which is based on the large government procurement market, the reinforcement of adaptive capacity of the local firms and the network of economic agents such as firm and supporting institutions, but also high flexibility of the knowledge-based service industry to a changing business environment.

• Journal of the Korean association of regional geographers
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• v.14 no.5
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• pp.521-535
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• 2008

This paper aims to explore the spatial distribution and locational characteristics of the shipbuilding industry in the south-east region of Korea. The geography of the Korea's shipbuilding industry illustrates an absolute spatial concentration into the south-east region, including Gyeongnam, Busan and Ulsan. In view of the type of agglomeration, it is argued that the south-east region's shipbuilding industry has been evolved as an Advanced Hub & Spoke cluster, which is characterized by interconnected relationships between a couple of gigantic customer firms and the majority of small and medium-sized supplier firms. A survey on the locational factors of the firms presents that traditional locational factors, such as physical infrastructure, land, labour and industrial linkages, are more important than new economic geographical locational factors, such as knowledge, learning, innovation and networks. According to firm's evaluation of the Gyeongnam region's locational environments for the shipbuilding industry is, however, rather different to the result of firm's location decision factors. The shipbuilding firms in Gyeongnam see that the Gyeongnam region retains regional advantages in terms of agglomeration economies, geographical proximity to customers, the infrastructure of transportation and communication and the quality of life. On the contrary, firms recognize that the Gyeongnam region suffers from the lack of R&D and production workforce and a weak basis of industry-university -government networks.

• Polymer(Korea)
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• v.35 no.6
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• pp.513-519
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• 2011

Molecular simulations via the molecular dynamics method have been carried out to investigate the dynamic collision properties of penetrable-sphere model fluids. The collision frequencies, the mean free paths, the angle distributions of the hard-type reflection and the soft-type penetration, and the effective packing fractions are computed over a wide range of the packing fraction ${\phi}$ and the repulsive energy ${\varepsilon}^*$. The soft-type collisions are dominated for lower repulsive energy systems, while the hardtype collisions for higher repulsive energy systems. Very interestingly, the ratio of the soft-type (or, the hard-type) collision frequency to the total collision frequency is directly related with the Boltzmann factor of acceptance (or rejection) probabilities in the canonical ensemble Monte Carlo calculations. Such dynamic collision properties are shown to be restricted for highly repulsive and dense systems of ${\varepsilon}^*{\geqq}3.0 $and ${\phi}{\geqq}0.7$, indicating the cluster forming structures in the penetrable-sphere model.

• Information Systems Review
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• v.19 no.4
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• pp.43-62
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• 2017

This study investigates the effect of bonding and bridging social capital on the technological innovation performance in the Pangyo Techno Valley. In particular, we consider the information technology (IT) usage in industrial cluster as an antecedent of social capital. IT instigates the intra and extra communication and information sharing between employees, thereby promoting the formation of a network of various members. Results show that the IT usage factor positively affects both bridging and bonding social capital, but an evident difference exists among the effects of social capital on the technological innovation performance. In case of Pangyo industrial cluster, bridging social capital exerts significant effect on the technological innovation performance, whereas bonding social capital shows insignificance. Bridging social capital is composed of the interactions of various networks. Bonding social capital is based on the strong tie from trust and internal cooperation. Results are related with the characteristics of Pangyo Techno Valley, where various IT ventures need active communication and information sharing with other organizations for technological innovation performance.