• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.10a
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• pp.223-228
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• 1987

• The Magazine of the IEIE
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• v.21 no.7
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• pp.37-42
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• 1994

• Information and Communications Magazine
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• v.14 no.3
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• pp.39-48
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• 1997

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1984.10a
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• pp.6-6
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• 1984

• Journal of Korean Electronics
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• v.12 no.3
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• pp.88-92
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• 1992

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7B
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• pp.464-468
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• 2005

The DVR industry has been grown with their own, proprietary systems without the need of standards because the security products are independently installed in small scale and the communication needs are very limited. The industry might have tighter security than having standardized products, but the appearance of IP surveillance and the need of communications with IP products such as IP Phones and IP-PBX made the standardization unavoidable. In this paper, we built an IP surveillance system with SIP based session control and investigated the applications of it other than the security itself.

• Smart Media Journal
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• v.4 no.4
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• pp.47-55
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• 2015

Recently, the computing paradigm has been changing and VoIP technology is being revisited to support various services in ICT field. In this paper, we have designed and implemented the systems of software PBX open source Asterisk using light-weighted virtualization Docker technique, hardware platform, and mobile devices to support voice service based on secured mobile VoIP. And we verified the delay test of network traffics and the secured voice communication test in global real network environment.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.143-154
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• 2002

Recently, new appliances have become built-in ethernet Port but most of the old devices have serial port. So, it complicates and needs long time to maintain at a long distance. It can only controllable and fixable using modem. In this paper, we developed an embedded STEP converter within Linux operating system and other application software so that serial devices(PBX) can control in the ethernet network After completion of development processes, test was conducted. In the remote places, it was connected the STEP converter and controled the serial PBX. Finally, we confirmed that it can apply to other equipments.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.208-209
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• 2013

본 연구에서는 철갑소이탄이 장갑을 관통한 후 전투시스템 내의 적재포탄(고폭탄 또는 추진제)에 피탄되었을 때 순간화재 발생확률에 대해 전산해석을 수행하였다. 장갑은 RHA 재질로 설정하였고, 장갑 두께를 5~30 mm까지 5 mm씩 증가시키며 전산해석을 실시하였다. 고폭탄은 COMPB, TNT, PBX가 사용되었으며 추진제는 ANB가 사용되었다. 본 해석은 Autodyn 프로그램을 사용하였으며, 순간화재 발생 여부를 해석하기 위해 Lee-Tarver ignition and growth model을 사용하였다. 해석 결과, 철갑소이탄이 고폭탄 TNT와 PBX에 피탄되었을 때, 순간화재 발생확률이 모두 100%를 나타내었으며, 고폭탄 COMPB의 경우, 0.8~0.08%로 나타났다. 추진제 ANB의 순간화재 발생확률은 3.8~3.6%로 나타났다.

• Journal of the Korean Ceramic Society
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• v.33 no.7
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• pp.743-754
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• 1996

In this study (Ba1-xPbx)TiO3 was synthesized by modified oxalate process in order to prevent vaporization of PbO through low temperature synthesis climinate Cl ion reproducibly substitute Pb for by and uniformly distribute ion (Ba1-xPbx)TiO3 was synthesized by coprecipitation of lead acetate barium acetate and ammonium titanyl oxalate have been used as starting materials. The substitution of Pb for Ba was reproducibly possible synthetic temperature of perovskite structure becomes lowed as the Pb concentration increases and fine partic-les (specific surface are :7.2 cm2/g) were obtained, BaTiO3 powders calcined at 90$0^{\circ}C$ for 3 hours were cubic from in XRD analysis and as Pb content was increases evident split of tetragonal peaks could be observed The optimum conditions to synthesize (Ba,Pb)TiO3 powder are the followings ; synthesis temperature (5$^{\circ}C$)