• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.15-20
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• 2016

In this paper, we developed the hardware GPS signal generator for generating a GPS L1 meaconing signal with Live GPS signal signals and analyzed the performance of meaconing signal generator thorough the experiment. Deception of the signal, such as a re-broadcast, it is an object of the user to provide false information so as not to receive location information and accurate time. The signal just rebroadcast has the features that can be easily deceive the receiver via a delay of no received signal to the signal processing through an antenna. In this paper, the hardware for generating a signal only these rebroadcast designed and manufactured, by re-sending the received Live GPS signals, to confirm the effect of the receiver. The maximum delay time is possible up to about 2.6msec, also, has been successfully tested to be moved to the position of re-broadcasting based on maturity antenna the position of the receiver through a spaced antenna.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.84-85
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• 2015

자막방송은 지상파 방송 수신을 통해 시청 가능한 자막 서비스를 의미하며, 현재 모든 지상파 방송 프로그램에 대해 자막방송이 제공되고 있다. 자막방송을 위한 자막 데이터는 일반적으로 속기를 통해 입력되며, 방송에서 속기를 통해 작성된 자막 데이터는 파일로 저장되어 해당 방송 프로그램에 대한 메타데이터로 활용되거나, 동일한 프로그램이 재방송으로 편성될 경우의 자막방송에 활용될 수 있다. 하지만 재방송의 경우 편집으로 인해 본방송과 내용상의 차이가 발생할 수 있으므로 편집이 발생한 부분을 포착하여 자막 데이터에도 동일한 편집을 적용한 후에 자막방송으로 활용되어야 한다. 따라서 재방송 송출에 기존 자막파일이 활용될 경우 반드시 전처리를 통해 자막과 영상의 내용을 일치시키는 과정이 필요하다. 그러나 방송 현장의 재방송 편성/송출 워크플로우에서는 자막 전처리를 위해 필요한 정보들이 갖춰지지 않는 예외적인 경우가 종종 발생하기 때문에 이를 해결하기 위한 방법이 필요하다. 이에 본 논문에서는 방송 현업의 재방송 편성/송출 워크플로우에서 파일기반 자막송출 기능을 안정적으로 사용하기 위해 자막 전처리 과정에서 발생할 수 있는 오류들에 대한 대처방법을 설명하고, 그 방법을 구현한 시스템을 소개한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1759-1761
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• 2016

In this letter, we propose a GPS repeat-back jamming signal detection scheme based on the sample variance of the horizontal location of a receiver and evaluate the detection performance using real positioning data of the GPS receiver.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1756-1758
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• 2016

Pseudorange is the pseudo distance between a GPS satellite and a GPS receiver to determine the receiver's position. The closer the distance between jammer and victim receiver is, the more effective a repeat-back jamming is. In this letter, we analyze the pseudorange difference between adjacent GPS receivers using real GPS pseudorange data to understand the effects by the repeat-back jamming.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1306-1312
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• 2017

The route request (RREQ) packet is selectively re-broadcasted in the routing protocols that improve the broadcast storm problem of the ad-hoc on-demand routing protocol (AODV). However, in a low node density scenario, the connectivity of these selective rebroadcast schemes becomes less than that of the AODV. In order to clarify the requirements of these selective re-broadcast routing protocols, it is necessary to investigate the relationship between the node density and the connectivity. In this paper, we drive a probability to preserve the connectivity of the GAODV at an intermediate rebroadcast node. In addition, we present an intuitive method to approximate the end-to-end connectivity of the GAODV. We draw the required node density to guarantee the connectivity of 0.9 and 0.99 through computer simulations, and verify the validity of the derived theoritical connectivity by comparing with the simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10A
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• pp.956-963
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• 2008

In a multi-hop wireless ad hoc network broadcasting is an elementary operation to support route discovery, address resolution and other application tasks. Broadcasting by flooding may cause serious redundancy, contention, and collision in the network which is referred to as the broadcast storm problem. Many broadcasting schemes have been proposed to give better performance than simple flooding in wireless ad hoc network. How to decide whether re-broadcast or not also poses a dilemma between reachability and efficiency under different host densities. In this paper, we propose enhanced broadcasting schemes, which can reduce re-broadcast packets without loss of reachability. Simulation results show that proposed schemes can offer better reachability as well as efficiency as compared to other previous schemes.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.85-87
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• 2010

이제 우리는 텔레비전 프로그램을 이동전화기로 보는데 익숙하다. 방송과 통신융합의 패러다임이 가져 온 변화에 빠르게 적응해나가고 있으며, 그 중심에 모바일 TV가 있다. 하지만 시청하는 미디어 기기만 다를 뿐, 플랫폼에 적합한 새롭고 참신한 콘텐츠를 찾아보기란 매우 어렵다. 이동 중 시청이 편리한 모바일 TV가 단순한 재방송 시청을 위한 기기에 불과하다면 분명히 문제가 있다. 본 연구에서는 양방향, 위치기반서비스, 가속도센서 등으로 중무장한 스마트폰과 모바일 TV의 마리아주를 통해 모바일 TV 3.0의 신개념을 제안하고, 이를 중심으로 한 차별화된 프로그램 장르별 제작 방안을 모색하고자 한다.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.731-741
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• 2016

It has become five years since comprehensive programming licenses were rendered in Korea. Allocating a lion's share of their air time on live news and news commentaries, those channels have established a unique live production system or a broadcasting system which is heavily live production-oriented, to be exact. The live commentaries are filled with a mixture of news flashes, conventional news commentaries, and debates. Those channels get their news and commentary programs made through subsidiaries' where production directors and studio staffs belong. They, being very sensitive about viewer rating, tend to be aggressive about reruns of highly rated programs and they do not even seem to care when the regular programs actually went out. This kind of reckless strategy to pursue a higher viewer rating could limit not only new programming attempts but also exposure diversity.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.9
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• pp.977-983
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• 2014

A repeat-back jamming signal is an intentionally re-broadcasted GNSS (Global Navigation Satellite System) interference. In this paper, a novel repeat-back jamming detection scheme is proposed. The proposed scheme uses a combined pseudo random noise signal (C-PRN) and is available for a generic GNSS receiver with a single antenna. The C-PRN signal is made by combining several received pseudo random noise signals that had been transmitted from the visible GNSS satellites. Through a Monte-Carlo simulation, the detection probability of a repeat-back jamming signal detected with the proposed scheme is presented.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.665-670
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• 2016

This paper proposes a repeat-back jamming signal detection scheme using a correlation ratio test metric of a combined pseudo-random noise signal for global navigation satellite systems. The correlation ratio test metric allows for the monitoring of possible distortions in the signal correlation. The proposed scheme is a modified version of the correlation ratio test metric to detect a repeat-back jamming signal in a multipath environment. Through a Monte-Carlo simulation, it is confirmed that the proposed scheme detects almost the whole case, which is received a repeat-back jamming signal under the 6 dB jamming to signal power ratio.