• ETRI Journal
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• v.38 no.1
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• pp.9-17
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• 2016

We demonstrate a time- and wavelength-division multiplexed passive optical network system employing a vertical-cavity surface-emitting laser array-based optical line terminal transceiver and a tunable bidirectional optical subassembly-based optical network terminal transceiver. A packet error-free operation is achieved after a 40 km single-mode fiber bidirectional transmission. We also discuss an arrayed waveguide grating, a photo detector array based on complementary metal-oxide-semiconductor photonics technologies, and low-cost key devices for deployment in access networks.

• ETRI Journal
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• v.37 no.5
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• pp.833-844
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• 2015

Recently, new network systems have begun to emerge (for instance, 5G, IoT, and ICN) that require capabilities beyond that provided by existing IP networking. To fulfill the requirements, some new networking technologies are being proposed. The promising approach of the new networking technology is to try to overcome the architectural limitations of IP networking by adopting an identifier (ID)-based networking concept in which communication objects are identified independently from a specific location and mechanism. However, we note that existing ID-based networking proposals only partially meet the requirements of emerging and future networks. This paper proposes a new ID-based networking architecture and mechanisms, named IDNet, to meet all of the requirements of emerging and future networks. IDNet is designed with four major functional blocks-routing, forwarding, mapping system, and application interface. For the proof of concept, we develop numeric models for IDNet and implement a prototype of IDNet.

• ETRI Journal
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• v.35 no.1
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• pp.1-6
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• 2013

In this paper, we present an implemented serial 40-Gb/s receiver optical subassembly (ROSA) module by employing a proposed TO-CAN package and flexible printed circuit board (FPCB). The TO-CAN package employs an L-shaped metal support to provide a straight line signal path between the TO-CAN package and the FPCB. In addition, the FPCB incorporates a signal line with an open stub to alleviate signal distortion owing to an impedance mismatch generated from the soldering pad attached to the main circuit board. The receiver sensitivity of the ROSA module measures below -9 dBm for 40 Gb/s at an extinction ratio of 7 dB and a bit error rate of $10^{-12}$.

• Informatization Policy
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• v.30 no.2
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• pp.3-21
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• 2023

The recent Internet environment demands a new approach to Internet content regulation. The need for regulation on the Internet has been recognized due to the rise of digital sex crimes, illegal information such as drugs and suicide, fake news, hate speech, false consumer reviews, and harmful content for young people. This article attempts to analyze the legislative, judicial, and administrative aspects of Internet content regulation in Korea. It covers the current status and characteristics of the Internet content regulation law, the judicial judgment on KCSC's communications deliberation and regulation, and the process and characteristics of KCSC's communications deliberation. Problems in Korea's communications deliberation system were addressed through legislative, judicial, and administrative approaches. This article concludes with policy suggestions for improving Internet content regulation in Korea.

• ETRI Journal
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• v.37 no.6
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• pp.1055-1064
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• 2015

We demonstrate a next-generation high-capacity mobile fronthaul based on radio over fiber (RoF) technology, which links between a digital unit and a radio unit supporting two frequency assignments and $2{\times}2$ multiple input, multiple output antennas. To confirm the technical feasibility of a mobile fronthaul, we experimentally investigate its down- and uplink end-to-end performances including the optical and radio frequency (RF) signal path. Frequency-dependent performance deviations, error vector magnitude variations, overall system performance variations caused by optical to electrical conversion, and intermediate frequency to RF conversions are examined. Experimental verifications on multiple LTE uplink signals are performed for the first time. We also demonstrate several commercial mobile Internet services, YouTube video streaming, and file transfers using off-the-shelf mobile devices, through a mobile fronthaul based on RoF.

• ETRI Journal
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• v.37 no.4
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• pp.657-666
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• 2015

We propose a two-stage resource allocation algorithm for the high link utilization of an orthogonal frequency-division multiplexing passive optical network (OFDM-PON). An OFDM-PON is assumed to use a synchronous frame structure in supporting service differentiation. In distributing resources, the proposed algorithm first allocates a time window for each optical network unit (ONU), and then it arranges a subchannel, which is a group of subcarriers. This algorithm needs to satisfy two constraints. First, computations for the resource allocation should be done using a frame unit. Second, an ONU has to use a single subchannel to send upstream data for multiple services within a frame duration. We show through a computer simulation that the proposed algorithm improves the link utilization.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.318-321
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• 2001

We have designed an Internet voting system applicable for worldwide voting which is based on Ohkubo et. al,'s scheme[9] combined with Public Key Infrastructure (PKI). To the best of our knowledge, this is the first trial to serve secure Internet voting system to the world. In our system, voter's privacy is guaranteed by using blind signature and mix-net, and robustness is provided through the threshold encryption scheme. By employing Java technology, we propose a way of typical implementation for internet voting system. Furthermore, PKI permits worldwide key distribution and achieve “one certificate/one vote” policy. Therefore, anyone can participate in the voting if he gets a certificate from Certificate Authority (CA). By the joint work between Korean and Japanese teams, the implementation aims to select MVPs in 2002 FIFA World Cup Korea-Japan$\^$TM/ in easy and friendly manner for any Internet user to participate and enjoy Internet voting.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.175-177
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• 2013

본 논문에서는 스마트폰의 장점인 언제 어디서나 편리하게 네트워크를 활용하여 인터넷 서비스를 사용 할 수 있는 점과 다양한 기능을 제공하는 애플리케이션 "나도 입대할래!"를 구현하여 사용자에게 편의제공을 할 수 있도록 하였습니다. 이 애플리케이션은 군대의 정보 중 입대 전 필요한 정보와 군대 생활에 필요한 정보를 사용자가 구분하기 쉽게 설명을 읽고 서로 동감할 수 있는 틀을 만들어 다양한 정보를 확인 할 수 있게 합니다. 구현된 애플리케이션은 기존에 있는 다른 군대 전용 애플리케이션과는 다르게 와이파이 서비스를 이용한 의사 소통공간을 제공하였고, 다양한 정보를 알려주고 군대의 즐거운 추억을 이야기 할 수 있게 합니다. 그 결과 본 논문에서 구현된 애플리케이션은 군 입대자와 부모님 또는 군대 생활에 관심이 있는 사람에게 정보교환을 다양하게 활용할 수 있는 정보교환의 장으로 기대됩니다.

• ETRI Journal
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• v.36 no.6
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• pp.1066-1069
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• 2014

We propose a lane adaptive recovery scheme for multiple lane faults in a multi-lane-based Ethernet link. In our scheme, when lane faults occur in a link, they are processed not as full link faults but as partial link faults. Our scheme provides a higher link utilization and lower packet loss rate by reusing the available lanes of the link and providing a low recovery time of under a microsecond.

• Journal of the Korean Home Economics Association
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• v.42 no.5
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• pp.127-143
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• 2004

This study examined the direct and indirect influences of adolescents' self-esteem, impulsiveness, departments of school, perceived communications with mothers and peer support on internet-related delinquencies. The study consisted of 555 second-year students from a vocational, academic oriented girl's high schools that were located in Busan. Data analysis was made through Two-Way ANOVA, Pearson's Correlation, Multiple Regression, and Path Analysis by using SPSS WIN 10.0. The results of this study is described as follows. First, internet-related delinquencies were committed by male students more than by female students. Second, problematic communications with mothers was most directly influenced by internet-related delinquencies of high school students of both sexes and was indirectly influenced by self-esteem and impulsiveness. Third, impulsiveness was directly influenced by internet-related delinquencies in both male and female students. In male students, their school departments indirectly influenced internet-related delinquencies by way of open communication with mothers, peer support, self-esteem, and impulsiveness. In female students, school departments directly influenced on internet-related delinquencies and indirectly by way of peer support, self-esteem and impulsiveness. Internet-related delinquencies by male and female students were not directly influenced by peer support and self-esteem. But peer support did have indirect effects on internet-related delinquencies by way of self-esteem and impulsiveness, and self-esteem also had indirect effects by way of impulsiveness.