• Broadcasting and Media Magazine
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• v.10 no.3
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• pp.69-76
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• 2005

무선 1394는 AV기기의 멀티미디어 통신 방식의 대표인 IEEE1394와 무선 기술을 접목시킨 기술로서, 차세대 홈네트워크 분야의 핵심적인 기술이라 할 수 있다. 특히, 등시성(Isochronous) 전송이 가능하며, 400Mpbs 이상급의 고용량, 고속 전송이 가능하여 HDTV급의 멀티미디어 응용 서비스가 가능하다. 또한 최근 급증하고 있는 유비쿼터스 및 홈네트워크 부분에서의 정보가전 기기 뿐만 아니라, 방송/통신 융합서비스에 이르기까지 다양하게 사용될 수 있다. 본 원고는 무선1394의 기술과 표준화 동향, 산업체에서의 시장 동항을 분석한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1346-1355
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• 2005

Recently, the development of passive optical networks (PON) for FTTH (Fiber-To-The-Home) have been actively conducted. In PON, a burst-mode transceiver is one of key modules. In this paper, we have made the protype module of a 155.52 Mpbs optical burst-mode transceiver with commercially available chips and then have measured the performance. Also, a new method of burst-mode clock recovery have been proposed. The burst-mode clock recovery implemented by using CPLD(Complex Programmable Logic Device) has coupled with the above burst-mode transceiver and has been tasted.

• Journal of the Korean Ceramic Society
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• v.45 no.4
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• pp.220-225
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• 2008

Lead-free ferroelectric ceramics are widely researched today for industrial applications as sensors, actuators and transducers. Since $Pb(Zr_aTi_{1-a})O_3$-(PZT) has high Curie temperature($T_C$), high piezoelectric properties near its morphotropic phase boundary(MPB) composition and small temperature dependence electrical behavior, it has been used to commercial materials for wide temperature range and different application fields. According to the tolerance factor concept, since the $Bi^{3+}$ cation with 12-fold coordinate has a smaller ionic radius than 12-fold coordinate $Pb^{2+}$, most bismuth based perovskites possess a smaller tolerance factor. Therefore, MPBs with a higher $T_C$ may be expected in $Bi(Me^{3+})O_3PbTiO_3$ solid solutions. As in lead based perovskite systems, it is clear that we need to explore more materials in simple or complex bismuth based MPB systems. The objective of this study is to investigate the $Bi(Ni_{1_a}X_a)O_3-PbTiO_3(X=Ti^{4+},\;Nb^{5+})$ perovskite solid-solution. For improving the electronic conduction problem, the magnesium and manganese modified system was also studied.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.7
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• pp.402-413
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• 2004

This paper presents an Implementation of Korean standard 128-bit block cipher SEED for the small (8 or 16-bits) embedded system using a low-cost FPGA(Field Programmable Gate Array) chip. Due to their limited computing and storage capacities most of the 8-bits/16-bits small embedded systems require a separate and dedicated cryptography processor for data encryption and decryption process which require relatively heavy computation job. So, in order to integrate the SEED with other logic circuit block in a single chip we need to invent a design which minimizes the area demand while maintaining the proper performance. But, the straight-forward mapping of the SEED specification into hardware design results in exceedingly large circuit area for a low-cost FPGA capacity. Therefore, in this paper we present a design which maximize the resource sharing and utilizing the modern FPGA features to reduce the area demand resulting in the successful implementation of the SEED plus interface logic with single low-cost FPGA. We achieved 66% area accupation by our SEED design for the XC2S100 (a Spartan-II series FPGA from Xilinx) and data throughput more than 66Mbps. This Performance is sufficient for the small scale embedded system while achieving tight area requirement.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.25-38
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• 2013

Future wireless systems will be required to support the increasingly nomadic lifestyle of people. This support will be provided through the use of multiple overlaid networks which have very different characteristics. Moreover, these networks will be required to support the seamless delivery of today's popular desktop services, such as web browsing, interactive multimedia and video conferencing to the mobile devices. Thus one of the major challenges in the design of these mobile systems will be the provision of the quality of service (QoS) guarantees that the applications demand under this diverse networking infrastructure. We believe that it is necessary to use resource reservation and adaptation techniques to deliver these QoS guarantee to applications. However, reservation and pre-configuration in the entire service region is overly aggressive, and results in schemes that are extremely inefficient and unreliable. To overcome this, the mobility pattern of a user can be exploited. If the movement of a user is known, the reservation and configuration procedure can be limited to the regions of the network a user is likely to visit. Our proposed Proxy-UMP is not sensitive to increase of the search cost than other schemes and shows that the increasing rate of total cost is low as the SMR increases.