• Journal of KIISE:Databases
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• v.35 no.3
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• pp.257-271
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• 2008

Wireless broadcast environments has character that a number of mobile client can receive data streaming from central server no matter how they are so many. Because it is asymmetric bandwidth in that uplink and downlink bandwidth are different. This advantage helps wireless broadcast environments is used in many applications. These applications work almost read operation and need control concurrency using transaction unit. Previous concurrency control scheme in single channel is not adapted in multi channel environments because consistency of data are broken when a mobile client tunes in a broadcast cycle in a channel and then move into another channel and listen to different broadcast cycle with already accessed broadcast cycle. In this paper, we propose concurrency control for read-only mobile transactions in multiple wireless broadcast channel. First of all, we adapt index and data dedicated channel and propose LBCPC(Longest Broadcast Cycle Per Channel) as new unit of consistency. In index dedicated channel, it is repeatedly broadcasted data in same BCPC(Broadcast Cycle Per Channel) until LBCPC. And mobile transaction executes validation using control information every LBCPC. As a result, consistency of data is kept and average response time is shorter than one in single channel because waiting time for restart reduces. And as control information is broadcasted more frequently than in single channel, it is guaranteed currency about data accessed by transaction. Finally, according to the simulation result, we verify performance of our scheme in multi channel as comparing average response time with single channel.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.151-154
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• 2017

기존 중계시스템은 모든 신호들이 유선으로 연결되어 있어 중계차가 접근 할 수 없는 지역에서는 운용의 어려움 등 이동과 거리에 제약이 있다. 또한 수많은 케이블이 필요하기 때문에 결선작업이 복잡하고 작업시간이 오래 걸리는 단점을 가지고 있어 무선 중계 시스템을 이용하여 프로그램을 제작하면 이러한 문제점을 해결할 수 있다.. 이에 본 논문에서는 RF무선영상송수신기와 백팩 LTE등 무선중계시스템의 장단점을 비교분석하였고 이에 통해 효율적인 무선중계시스템을 설계하였다. 또한, 제안된 시스템을 이용하여 방송중계업무의 편리성이 극대화하고 새로운 형태의 방송 포맷을 개발할 수 있도록 하였다.

• The Korean Journal of Air & Space Law and Policy
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• v.21 no.1
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• pp.191-214
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• 2006

The right to the spectrum frequency and orbit is required for the broadcasting by satellite, whether the broadcaster might be given any license or authorization for the broadcasting. The reason is that the ITU Convention and Radio Regulation provide very specific and detailed rules regarding the utilization of the frequency spectrum and orbit. Outstanding issue arises as to the implementation process of the rules of international character. Domestic implementation of the Radio Regulation, in the way of letter to letter should be discouraged when the competitiveness of domestic industry vis-a-vis foreign competitor is taken into account.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.10
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• pp.239-244
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• 2019

In recent mobile environments, query processing costs have been rapidly increasing as users request large amounts of queries. In addition, the server's performance is increasing for many users to handle high-capacity queries, but the workload is increasing continuously. To solve these problems, we use the wireless broadcasting environment. However, in a existing wireless broadcasting environment, servers have a problem sending all the objects they manage to their clients. Therefore, we propose a new R-Bcast combining the advantages of demand-based and wireless broadcasting. R-Bcast is a technique that protects query information and reduces query processing time. Experiments have proved that R-Bcast is superior to conventional techniques.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.123-126
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• 2011

As the number of users of smart phone and smart pad are increasing, the deployment of WiFi APs has been accelerated. Also Internet local broadcasting service will be activated near future. But transmission error is the critical problem, due to the one-way transmission of the data to the receivers. In this paper, FER is analysed according to BER and frame length, and repetitive transmission technique is proposed to reduce the effective FER.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.267-269
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• 2019

TV홈쇼핑 생방송 제작 시 스튜디오 방송용 카메라 외에 추가로 다양한 카메라가 활용된다. 현재 지상파 방송 등에서 많이 활용되는 5D카메라는 홈쇼핑 생방송 제작 시 활용되어지고 그 활용도는 더욱 증가되고 있다. 본 논문에서는 활용도가 높아지고 있는 5D카메라 유선 인터페이스 활용이 아닌 60GHz 주파수 대역의 무선 영상 전송 시스템 생방송 제작에 관한 것이다.

• Broadcasting and Media Magazine
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• v.17 no.2
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• pp.94-105
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• 2012

• Broadcasting and Media Magazine
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• v.9 no.1
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• pp.47-60
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• 2004

• Broadcasting and Media Magazine
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• v.10 no.3
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• pp.53-68
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• 2005

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.203-209
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• 2012

Recently, k-nearest neighbors query methods based on wireless broadcasting environment are actively studied. The advantage of wireless broadcasting environment is the scalability that enables collective query processing for unspecified users connected to the server. However, in case existing k-NN query is applied in wireless broadcasting environment, there can be a disadvantage that backtracking may occur and consequently the query processing time is increasing. In this paper proposes a hierarchical bitmap-based spatial index in order to efficiently process the k-NN queries in wireless broadcasting environment. HBI reduces the bitmap size using such bitmap information and tree structure. As a result, reducing the broadcast cycle can reduce the client's tuning time and query processing time. In addition, since the locations of all the objects can be detected using bitmap information, it is possible to tune to necessary data selectively. For this paper, a test was conducted implementing HBI to k-NN query and the proposed technique was proved to be excellent by a performance evaluation.