• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.147-152
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• 2022

This study describes the design and implementation of EGSE for Dehop/Rehop Transponder. The EGSE is a equipment that evaluates Dehop/Rehop Transponder and requires precise and accurate measurement. EGSE consists of a PLDIU and IIU(Instrument Interface Unit), Up/Down converter for L band, Modems to verify the Dehop/Rehop Transponder. The EGSE was used for performance verification and space environment test such as thermal vacuum after developing Dehop/Rehop Transponder.

• The Magazine of the IEIE
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• v.35 no.10
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• pp.98-107
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• 2008

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.5
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• pp.42-48
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• 2008

In this paper, we have introduced a Code Division Multiplexing transmission method which is similar to OFDM and analyze ECCM performances. We have verified CDM transmission method has a good LPI performance and a feasible ECCM performance. This capability could be useful for reduction of RF interference which occurs when many equipments operate densely in small area. The equipment that uses CDM transmission method supports variable transmission rate and order-wire effectively and conveniently to user. This CDM method has similar ECCM performance comparing to serial DS method. CDM method has good multi-path signal processing capability and could be useful for mobile communication environment.

• Satellite Communications and Space Industry
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• v.8 no.1 s.18
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• pp.56-68
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• 2000

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.437-442
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• 2021

This study describes the design and implementation of power supply of dehop/rehop transponder of EQM(Engineering Qualification Model). We materialized the interface of the PLDIU and power supply of a satellite bus, and minimized the potential for the occurrence of such erroneous operation circuit ESD through the WCA of the space environment. We designed a reliable power supply through simulation for TID about space radiation and simulation of the vibration generated during it launched, and we confirmed that it satisfies the environmental test specification through the test space environment after production.

• Defense and Technology
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• no.8 s.126
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• pp.44-51
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• 1989

NATO의 작은 국가들중 가장 큰 나라로 자부심을 갖고 있는 네덜란드는 향후 10년간 육군의 전투력 증강에 최우선을 둘 것이며, 육군의 전투력은 다음과 같은 6개 분야에서 대폭 증강 될 것이다 .50대의 공격용 헬기 획득에 따른 대전차능력 증강 . $C^3I$ 전력증강 .현대화된 자전 장비 도입 .정면방어 제1군단 방공시스템 개선 .전장감시와 표적획득체계 개선 .개인 화생방 방호장비 개선

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2B
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• pp.151-159
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• 2002

Frequency synthesizer is an essential part for developing high speed frequency hopping radio. A high speed synthesizer using DDS driven PLL technique is designed and implemented for a X-band portable satellite terminal. It generates transmitter and receiver frequency ranging 6600∼7100MHz and 6140∼6640MHz, respectively by using 102.4MHz local oscillator, Its lock time is below 15 $\mu$sec and Its phase noise is below -754dBc at 1KHz offset Sequency.

• Journal of the Korean Regional Science Association
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• v.38 no.4
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• pp.75-91
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• 2022

With the recent increase in interest in climate change issues, the use of bicycles is complementing public transportation and attracting attention as one of the eco-friendly means of transportation. Daejeon Metropolitan City has been operating Tashu, a public bicycle, since 2008. This study empirically analyzed the spatial characteristics that affect the use of public bicycles by grasping the current status and characteristics of public bicycles and applying spatial econometrics analysis, an analysis model that considers the spatial dependence of spatial data. In addition, a comparative analysis was performed by deriving the results of analyzing six models in terms of rental, return, peak time, non-peak time, weekday, and weekend based on the spatial error model identified as the optimal spatial econometrics model. The analysis model results showed that significant spatial characteristics differed according to the type of public bicycle use. In general, the use of public bicycles was high in areas with a high proportion of young people, a high number of public transportation users, good access to universities and rivers, and relatively low land use mix, and high proportion of apartments. These results indicated that public bicycles are used for commuting purposes on weekdays and leisure purposes on weekends, and if the convenience of using bicycles is improved, the use of public bicycles can be further increased.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.8
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• pp.1-9
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• 2009

In this paper, we describe DSSS transceiver development robust to jamming signals as an investigation of ECCM transceiver for UAV uplink. The jamming margin is 15dB or greater with the development target of transceiver because the jamming margin is more important than the transmission rate of data and the spreading code can be changeable. The rake receiver is applied to combine multipath components and turbo code which the coding gain is 7.2dB as a FEC. In this paper, the whole structure, design method and functional test result about the designed modem are described and a conclusion is made.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.573-575
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• 2015

Positioning system using satellite GPS is used at positioning, navigation, acquisition time information and other various field and taking an important part precision guided weapon such as missile. But commercial code(C/A code) do not have ECCM. Therefore commercial code is vulnerable to various jamming techniques and noise jamming from near station can attack even the encrypted military code(P code) GPS. In this paper, GPS jamming techniques, North Korean GPS jamming cases and anti-jamming GP S technologies are surveyed and described.