• Proceedings of the Korean Information Science Society Conference
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• 2007.06a
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• pp.157-158
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.743-747
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• 1994

A process planning system that generates alternative process plans offers multiple process plans for a part, thereby provides the flexibility to cope with the changes in shop floor status. In this paper, we introduce the concept of process net as a model for the generation of alternative process plans. We also show the usefulness of process net model by implementing the developed system to generate alternative process plans for rotational parts.

• Journal of the KSME
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• v.57 no.8
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• pp.33-37
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• 2017

학문 간의 전통적 경계가 허물어지고, 기술 융합이 경제체제와 사회구조를 급격히 변화시키는 4차 산업혁명시대가 다가오고 있다. 스마트제조(smart manufacturing)는 인간, 기술, 정보의 융합을 통해 제조업의 전략적 혁신을 도모하고자 하는 패러다임으로서 ICT와 제조기술을 융합하고자 하는 기술이다. 또한 스마트공장(smart factory)은 이러한 기술 융합을 통하여 공장의 설비, 장비와 공정이 지능화되어 네트워크로 연결되고, 생산데이터와 정보가 실시간으로 공유 활용되어 최적화된 생산운영이 가능한 공장으로, 공장 간의 협업적인 운영이 지속되는 지능형 ICT융합 제조시스템을 말한다. 이 글에서는 제조업 ICT융합과 스마트화, 그리고 스마트공장의 개념, 구성과 관련 동향에 대해 소개하고자 한다.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.229-234
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• 2007

In the IEEE 802.11 Wireless Local Area Networks (WLANs), network nodes experiencing collisions on the shared channel need to backoff for a random period of time. which is uniformly selected from the Contention Window (CW) This contention window is dynamically controlled by the Binary Exponential Backoff (BEB) algorithm. The BEB scheme suffers from a unfairness problem and low throughput under high traffic load. In this paper, I propose a new backoff algorithm for use with the IEEE 802.11 Distributed Coordination Function.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.91-94
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• 2007

In the IEEE 802.11 Wireless Local Area Networks (WLANs), network nodes experiencing collisions on the shared channel need to backoff for a random period of time, which is uniformly selected from the Contention Window (CW). This contention window is dynamically controlled by the Binary Exponential Backoff (BEB) algorithm. The BEB scheme suffers from a fairness problem and low throughput under high traffic load. In this paper, I propose a new backoff algorithm for use with the IEEE 802.11 Distributed Coordination Function.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.64-73
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• 2000

Since so many potentials of services, applications, marketing and regulation, it is difficult to decide the fair pricing scheme of network services. However, these considerations are not particular to the operation of a communications network, which is closely related to technological constraints for QoS guarantee. In this paper, the power spectral analysis of MPEG video based on the P-MMBBP model is discussed in the manner of the QoS degradation to the packet delay. As a consequence of the QoS-degradation, a new fair-pricing scheme with the discount factor is proposed. As a result, the proposed scheme shows good characteristics to guarantee the fairness of the charging in the Internet wide-area network.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.199-207
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• 2018

This study aims to analyze Next Production Revolution (NPR) technologies through evidence-based keyword network in order to cope with the change of production paradigm called the Fourth Industrial Revolution (4IR). For the analysis, a total of 441 papers related to NPR or 4IR were extracted and the NPR technology network was constructed based on the simultaneous appearance relationship of the author keywords of these papers. Based on the NPR technology network, we explored key technologies through analysis of centrality and keyword group. As a result, technologies such as 'digital twin' and 'modeling and simulation', discovering insights by connecting the virtual and physical world in real time and reflecting them into design and process, are analyzed as key technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.119-124
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• 2010

The MAC layer in ad-hoc network which makes network of nodes without infrastructure for a time has became an issue to reduce delay, allocate fairly bandwidth, control TX/RX power and improve throughput. Specially, the problem to reduce power consumption in ad-hoc network is very important part as ad-hoc devices use the limited battery. For solution of the problem, many power control algorithms, such as distribute power control, PCM (Power Control MAC) and F-PCF (Fragmentation based PCM), are proposed to limit power consumption until now. Although the algorithms are designed to minimize power consumption, the latency communication zone is generated by power control of RX/TX nodes. However the algorithms don't suitably reuse the space. In this paper proposes the algorithm to improve data throughput through Spatial Reuse based on a power control method.

• Journal of the Korean Society for information Management
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• v.24 no.3
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• pp.43-65
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• 2007

Automatic recommendation system of panel pool should be designed to support universal, expertness, fairness, and reasonableness in the process of review of proposals. In this research, we apply the theory of probabilistic ontology to measure relatedness between terms in the classification of academic domain, enlarge the number of review candidates, and rank recommendable reviewers according to their expertness. In addition, we construct a researcher network connecting among researchers according to their various relationships like mentor, coauthor, and cooperative research. We use the researcher network to exclude inappropriate reviewers and support fairness of reviewer recommendation process. Our methodology recommending proper reviewers is verified from experts in the field of proposal examination. It propose the proper method for developing a resonable reviewer recommendation system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.41-41
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• 2008

제지산업은 다량의 용수를 사용하면서 또한 많은 양의 폐수를 배출하고 있다. 기존의 폐수처리 공정에서는 침전처리를 위한 큰 저수조와 오랜 침강 시간이 요구되어 제한된 공장 내에서의 처리에 어려움이 많다. 이러한 기존 기술의 문제점을 보완하면서도 새로운 고도처리가 가능한 초전도 마그네트를 이용한 자기분리 기술을 적용하고자 하였다. 자기문리의 기본 원리는 강력한 자기력에 의하여 액체에 포함된 자성입자를 분리해내는 것으로 자성입자들이 자계의 힘에 의하여 잡아당겨지고 포획됨으로서 제거되는 것이다. 자기분리용 솔레노이드 마그네트로 초전도마그네트를 적용하게 되면 아주 높은 고구배의 자장(HGMS; High Gradient Magnetic Separation) 을 발생시킬 수 있다. 초전도마그네트와 체(sieve) 형 자기필터를 이용하면 대공간에 전력손실 없이 고자장을 발생시킬 수 있기 때문에 미립자를 효과적으로 고속으로 분리하는 것이 가능해지며 또한 상자성 미세입자까지도 처리할 수 있다. 본 연구에서는 주로 유기물로 구성된 제지며|수의 부유물을 자성체와의 응집반응에 의해 플록을 형성하여 자성 플록의 자기분리 효과를 연구하였다. 자성응집반응의 특성을 평가하기 위하여 전자석 시스템을 제작하였으며 배치타입의 자기필터를 설계 제작하였다. 또한 응집제의 종류와 응집반응 공정에 따른 자성플록의 형성 정도를 조사하였으며 자기분리 후 폐수의 탁도, SS 등의 특성을 분석하였다. 그림 1은 자성응집반응의 특성을 평가하기 위하여 제작한 전자석 시스템을 나타내고 있으며 전자석의 자장해석 결과를 보이고 있다.