• 전기의세계
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• v.46 no.1
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• pp.28-32
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• 1997

진공관(전자관)은 무선통신, 레디오 방송, 레이다, 전자계산기, VHF 텔레비젼 방송, 마이크로웨이브중계, 컬러(color) 텔레비젼 방송, 전자계측, 전자진단, 위성통신, UHF 텔레비젼 방송, 위성방송 등 통신 및 전자기술의 발전에 상응하여 다양하게 발전 해 왔다. 이러하던 중, 1948년데 이르러 트랜지스터가 미국에서 발명되어 이 고체 디바이스가 대두하면서 이것이 발전을 거듭하는 동안 진공관(전자관)은 이 고체 디바이스와 경합을 하고 있으며 결과적으로 진공관(전자관)은 응용면에서 특히 통신, 방송에 관련되는 진공관들의 상당부분이 고체 디바이스에 자리를 넘겨주고, 시장도 극히 협소해졌다. 나아가 국제적인 동업자와의 경합, 진공관(전자관)동업자끼리의 경합이 있는 등, 진공관(전자관)의 환경은 점점 엄중해진 것이 현재의 상황이다. 그렇다고는 하지만, 여전히 진공관(전자관)이어야만 하는 영역이 있으며, 개발의 필요를 강하게 받고 있다. 이의 개발에 대한 국제협력의 길도 열려 있으며, 금후에도 기술의 계속과 발전을 위해서의 노력이 계속되어, 정력적인 개발이 진행되리라고 보아진다. 금후의 전개를 기대하고 싶다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1571-1578
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• 2014

Binary CDMA is a new standard technology for wireless communication developed by our country that makes high speed communications and good quality of services for multimedia data such as voice and video. In this paper we researched the design and implementation of a wireless Video Transmitter and Video Server - the main devices for the Automobile Wireless Camera System - based on the Binary-CDMA technology that makes them freely installed in any place without wired cables restriction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2A
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• pp.115-120
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• 2008

We propose a cooperative transmission scheme that uses Hurwitz-Radon space-time code for the relays which help the source to transmit signals to the destination, the full utilization here is that the destination utilizes the broadcast symbols from the source. We present the 2 transmit antennas case in detail because of its simplicity and high data rate. Analysis and simulations show that the proposed scheme achieves full diversity order of 3. The maximum likelihood receiver is also derived and the combining scheme is shown to be very simple.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.993-996
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• 2000

이동컴퓨팅 시스템에서 사용자는 언제 어디서나 통신 서비스를 받을 수 있어야 한다[1]. 이를 위해 mobile-IP 표준이 사용되고 있으며, 그 사용 범위는 광범위하게 확장되고 있는 추세이다. 이와 함께 mobile 네트워크와 다른 네트워크간의 통신도 중요하게 부각되고 있다. 본 논문에서는 이동컴퓨팅의 한 분야인 Ad-hoc 네트워크와 mobile 네트워크간의 통신이 가능하도록 하는 기법을 소개한다. 이를 위해 ad-hoc 이동 호스트 중 mobile-IP 네트워크에 포함되어 에이전트 광고 메시지(agent advertisement message)를 받는 ad-hoc 이동 호스트에 게이트웨이를 두어 패킷을 만들고 경로 정보를 유지하는 등의 기능으로 이 ad-hoc 이동 호스트의 중계에 의해 통신이 가능하도록 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1262-1263
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• 2012

이동하는 애드 혹 네트워크에서 통신장치의 통신가능영역을 구하는 문제는 네트워크를 운용하는 주요한 활동 중의 하나이다. 본 논문에서는 지형의 영향을 많이 받는 지상환경에서의 노드파괴나 이동으로 인해 링크실패가 발생되거나 임무수행영역 확대를 위해 중계기능을 수행하게 하기위한 통신가능 영역을 프레넬 영역 알고리즘의 기능을 확장하고 3차원 객체의 교차 알고리즘을 적용함으로써 효율적으로 구할 수 있는 방법을 제안한다.

• Electronics and Telecommunications Trends
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• v.38 no.2
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• pp.85-95
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• 2023

Space optical communication technology capable of large-capacity, high-speed, and low-latency communication can reduce the size, weight, and power consumption of radio frequency communications in existing satellite systems, thereby reducing launch costs, accommodating additional science instruments, and extending lifetime. Despite the high technical difficulty, various projects are being carried out in advanced countries regarding space technology for use in national security and defense, earth observation, and space communications. We review the advantages, key components, and development trends of space optical communication technology, which is attracting attention in applications such as satellite communications, intersatellite linking, and deep space communications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.139-145
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• 2016

On the ICT healing platform designed to issue early disease alerts, TOS connected between the provider of personal health-related data and the service provider and relayed personalized health data. In the previous study, TOS proposed how to monitor the retrieval and management of document/measurement resources by taking mobile devices into account. Recently the healthcare field, however, defined the standard items needed for communication and data exchanges with a mobile device through HL7 FHIR. This study designed a data grid model between TOS and FHIR to provide personal health resources relayed through TOS in FHIR bundle search sets. The proposed design was organized as follows: first, it stated similarities between the method of TOS resource request and that of FHIR observation request. Then, it designed an eventbus module to process a retrieval request for FHIR service based on the imdb and cluster technologies. The proposed design can be used to expand the old service terminals of ICT healing platform to mobile health devices capable of using FHIR resources.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.32-38
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• 2015

Next generation military satellite communication systems have been developed for expanding capacity and survivability. As for expanding capacity, the communication systems require efficient techonology to use limited resource. So, next generation communication systems are expected to use MF-TDMA technology. MF-TDMA is the technology which has the advantages of FDMA and TDMA. By using MF-TDMA, communication systems can use limited resource efficiently, and the performance of resource allocation depends on the allocation scheme. In this paper, we propose efficient allocation scheme for next generation military satellite communication systems. Also, we compare and analze performances such as Total Resource Efficient, Reject Ratio, Computational Time, PSD distribution with existing allocation schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.113-115
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• 2015

In this paper, we proposed an algorithm based on movement prediction using rate of change of the attribute information of nodes what is called WRC(Weighted Rate Control) in delay tolerant networks(DTNs). Existing DTN routing algorithms based on movement prediction communicate by selecting relay nodes increasing connectivity with destination node. Thus, because the mobile nodes are in flux, the prediction algorithms that do not reflect the newest attribute information of node decrease reliability. In this paper, proposed algorithm approximate speed and direction of attribute information of node and analysis rate of change of attribute information of node. Then, it predict movement path of node using proposed weight. As the result, proposed algorithm show that network overhead and transmission delay time decreased by predicting movement path of node.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.39-49
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• 2012

With group mobility, minimizing routing overhead among intra-group nodes can be achieved by making longer the routing update period, which may lead to degradation of inter-group's routing performance and consequently the inter-group packet delivery success ratio will be decreased. To reduce the inter-group routing overhead without lowering the inter-group packet delivery success ratio, a mobility-adaptive routing update(MARU) scheme is proposed in this paper. Main idea of the proposed scheme is group-based mobility prediction and updating routing paths by selecting intermediate common relay groups.