• Korean Journal of Rural Living Science
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• v.2
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• pp.91-107
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• 1991

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.79-85
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• 2006

We concern practical of utilizable frequency with wireless communication and broadcast technology. And, present that wireless application technology such of Ubiquitous sensor network, mobile or fixed wireless communication and wireless broadcast will require more efficiently using of frequency. In this paper, we studied Cognitive Radio that necessity of cognitive and intelligent technology in variable wireless environment and IEEE 802.22 standardization.

• Journal of Digital Contents Society
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• v.6 no.3
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• pp.179-184
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• 2005

We concern practical of utilizable frequency with wireless communication and broadcast technology. And, present that wireless application technology such of Ubiquitous sensor network, mobile or fixed wireless communication and wireless broadcast will require more efficiently using of frequency. In this paper, we studied Cognitive Radio That necessity of cognitive and intelligent technology in variable wireless environment and IEEE 802.22 standardization.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.215-218
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• 2005

무선통신 및 방송 기술의 발달과 함께 주파수 자원의 효율적 활용에 대한 관심이 더욱 높아지고 있다. 또한 향후 유비쿼터스 센서 네트워크, 이동 및 고정 무선통신, 무선방송 등 다양한 무선 응용 기술들이 혼재된 상황은 주파수 자원의 효율적 이용에 대한 요구를 강화할 것으로 예상된다. 본 논문에서는 다양한 무선자원을 능동적으로 인지하여 동적으로 변화하는 사용자의 요구 및 상황에 적합하도록 유휴 무선자원을 지능적으로 활용하는 제반 기술인 Cognitive Radio의 필요성 및 발전 방향과 IEEE 802.22 표준화 동향을 알아본다.

• Korean Journal of Cognitive Science
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• v.30 no.1
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• pp.1-30
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• 2019

The main goal of this paper is to understand the underlying cognitive mechanisms of collaborative learning and how it can be supported by technology. The paper first overviews changes in conceptions of learning and distinguishes different types of joint works including collaborative learning. Cognitive mechanisms of collaborative learning are examined in terms of resource pooling, facilitation of constructive activities, knowledge co-construction, and supports for monitoring and regulation. Socio-emotional mechanisms of collaborative learning moderate the directions and strengths of these cognitive mechanisms. Technology supports these mechanisms in a number of different ways. Seven major supports technology provides for collaborative learning are discussed. A deeper understanding of the cognitive mechanisms of collaborative learning can help us to harness the benefits of collaborative learning better and also to develop more sophisticated tools supporting collaborative learning.

• Korean Journal of Cognitive Science
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• v.16 no.3
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• pp.155-174
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• 2005

Oh and Kim (2004) and Woodman and Lurk (2004) demonstrated that spatial working memory (SWM) load Interfered concurrent visual search and that search process also impaired the maintenance of spatial information implying that visual search and SWM task both require access to the same limited-capacity mechanism. Two obvious possibilities have been suggested about what this shared limited-capacity mechanism is: common demand for attention to the locations where the items f9r the two tasks were presented (spatial attention load hypothesis), and common use of working memory to maintain a record of locations have been processed(SWM load hypothesis). To test these two hypothetical explanations, Experiment 1 replicated the mutual interference between visual search and SWM task in spite of difference of procedure with preceding researches; possible areas where the items for two tasks were presented were not separated. In Experiment 2, we presented the items for visual search either in the same quadrants where the items for SWM task had appeared (same-location rendition) or in the different quadrants (different-location condition). As a result, search efficiency was more impaired in the different-location condition than in the same-location condition. The memory accuracy was worse in the different-location rendition than in the same-location rendition. Overall results of study indicate that the mutual interference between SWM and visual search might be related to the overload of spatial attention, but not to that of SWM.

• Information and Communications Magazine
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• v.27 no.8
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• pp.43-49
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• 2010

향후 다양한 무선/이동 액세스 네트워크가 서로 연동하여 동작하는 환경에서 무선자원을 효율적으로 이용하고 사업자 및 사용자의 요구사항을 만족시킬 수 있는 이동/무선 네트워크를 위한 연동구조가 요구된다. 이에 본 고에서는 IEEEP1900.4및 IEEE 802.21에서 제시하는 표준기술을 이용하여 Smart Radio 시스템의 구조 및 Universal Access를 위한 Framework를 제안하고 동작 시나리오 및 기능 모듈간의 연동절차를 제시한다. 또, 제안된 시스템구조 및 Framework의 기능 및 성능을 분석하기 위해서 시스템수준 시뮬레이터를 설계/구현에 대해서 기술한다. 성능분석의 결과, 제안한 시스템 연동구조 및 Framework를 이용할 경우, 이동단말은 액세스 네트워크의 통신환경을 자율적으로 인지할 수 있었으며 무선자원을 효율적으로 이용할 수 있었다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.37-40
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• 2015

본고에서는 "주파수 자원 이용효율 향상을 위한 계층적 간섭대응 핵심기술 개발"을 목표로 연구를 수행하고 있는 숭실대학교 인지무선통신연구소에 대하여 소개하고, 연구소에 포함된 각 연구실에서 진행하고 있는 연구에 대해서 소개한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.35-41
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• 2017

To solve the shortage of radio spectrum and utilize spectrum resource more efficiently, cognitive radio technologies are proposed, and many studies on cognitive radio have been conducted. Multi-hop routing is one of the important technologies to enable the nodes to transmit data further with lower power in ad-hoc cognitive radio networks. In a multi-channel cognitive radio networks, each channel should be allocated to minimize interference to primary users. In the multi-hop routing, channel allocation should consider the inter-channel interference to maximize network throughput. In this paper, we propose multi-channel scheduling scheme which minimizes inter-channel interferences and avoids collision with primary users for the multi-hop multi-channel cognitive radio networks. The proposed scheduling is designed to determine both of routing path and channel selection. The performance of proposed channel allocation scheme is evaluated by the computer simulation in the aspect of capacity and collision rate.

• Information and Communications Magazine
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• v.25 no.3
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• pp.48-52
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• 2008

인지 무선(CR: Cognitive Radio) 시스템은 SDR(Software Defined Radio) 기술을 기반으로 주변 환경을 인지하여 가용한 주파수를 선정하고 통신하는 기본적인 기능과 여러 가지 환경 파라미터를 지속적으로 업데이트하는 학습 알고리즘이 합쳐진 기술이다. CR기술은 최근 무선 통신 서비스의 발전으로 주파수의 수요가 증가하면서 사용하지 않는 주파수 자원을 효율적으로 이용하기 위한 기술로써 각광받고 있다. CR시스템을 단말에 적용 및 구현하기 위해 선행되어야 하는 연구 분야는 크게 하드웨어 분야와 소프트웨어 분야로 나누어 생각할 수 있다. 하드웨어 분야에 관련된 연구는 다시 RF 처리부와 디지털 신호 프로세스부로 나눌 수 있다. 본 논문에서는 CR 시스템을 단말에 적용하기 위해 필요한 선행 기술들을 살펴보고, 실제 단말에 적용 했을 때의 단말 형태에 대해 알아본다.