• Title/Summary/Keyword: 인터넷 위상

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Performance of privacy Amplification in Quantum Key Distribution Systems (양자 키 분배 시스템에서 보안성 증폭의 성능 분석)

  • Lee, Sun-Yui;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.5
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    • pp.111-116
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    • 2018
  • This paper introduces the concept of a random universal hash function to amplify security in a quantum key distribution system. It seems to provide security amplification using the relationship between quantum error correction and security. In addition, the approach in terms of security amplification shows that phase error correction offers better security. We explain how the universal hash function enhances security using the BB84 protocol, which is a typical example of QKD(Quantum Key Distribution). Finally, we show that the BB84 protocol using random privacy amplification is safe at higher key rates than Mayers' performance at the same error rate.

GNUnet improvement for anonymity supporting in large multimedia file (대형 멀티미디어 파일의 익명성 지원을 위한 수정 GNUnet)

  • Lee, Yoon-Jin;Lee, Myoung-Hoon;Jo, In-June
    • Journal of Internet Computing and Services
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    • v.7 no.5
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    • pp.71-79
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    • 2006
  • The GNUnet proposed a file encoding method by lKB block size to support anonymity of files and decentralizes encoded block to peers through unstructured model. but, the encoding and block decentralizing method with 600$\sim$700MB large multimedia file appeared two problems. First problem. it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructured model added network load by broadcasting decentralizing method. This paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation to 1% and network load by proposal structured model sending answer through dedicated peer to decentralize block.

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Demand Analysis and Market Positioning for WiBro (와이브로(WiBro) 수요분석과 위상정립 방향)

  • Park, Jong-Hyun;Park, Hee-Jin;Kim, Moon-Koo
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.10d
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    • pp.441-444
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    • 2006
  • 통신기술의 급격한 발전, 유비쿼터스에 대한 시장수요 증가, 신규 시장창출을 위한 비즈니스 전략이 결집되어 유무선 융합의 패러다임이 전개되고 있으며 유선의 전송속도와 무선의 이동성을 결합한 와이브로는 유무선 융합을 주도할 서비스로 부각되고 있다. 2006년 상반기에 상용화 될 예정인 와이브로가 안정적인 가입자 기반으로 조기에 시장확산을 이루기 위해서는 동시기에 출시될 HSDPA에 비하여 차별적 지위를 확보하고 기존 서비스와의 관계를 정립하기 위한 포지셔닝 전략이 요구된다. 이에 본 연구에서는 소비자 설문조사를 통해 와이브로의 시장수요를 HSDPA와의 관계 분석을 바탕으로 전망하며 기존 서비스와의 대체 또는 보완 관계를 파악하여 와이브로의 시장위상을 예측하였다. 분석결과 첫째, 잠재적 이용자가 인식하는 와이브로의 서비스 역량은 HSDPA에 비하여 전송속도와 이용요금에서 차별적 우위를 나타냈으며 둘째, 와이브로는 HSDPA에 비하여 가입자 규모에서 상대적인 우위를 보였으며 두 서비스의 가입 영향요인은 상이하였다. 마지막으로 와이브로는 초고속인터넷과는 보완 관계를, 이동전화 무선인터넷과 공중 무선랜과는 대체 관계를 형성하는 것으로 나타났다.

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Design of a Multiband CMOS VCO using Switched Bondwire Inductor (스위치드 본드와이어 인덕터를 이용한 다중대역 CMOS 전압제어발진기 설계)

  • Ryu, Seonghan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.6
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    • pp.231-237
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    • 2016
  • This paper presents a multiband low phase noise CMOS VCO with wide frequency tunability using switched bondwire inductor bank. The combination of bondwire inductor and CMOS switch transistor enhances frequency tunability and improves phase noise characteristics. The proposed multiband VCO operates from 2.3GHz to 6.3GHz with phase noise of -136dBc/Hz and -122dBc/Hz at 1 MHz offset frequency, respectively. Switched bondwire inductor bank shows high quality factor(Q) at each frequency band, which allows better tradeoff between phase noise and power consumption. The proposed VCO is designed in TSMC 0.18um CMOS process and consumes 7.2 mW power resulting in figure of merit(FOM) of -189.3dBc/Hz at 1 MHz offset from 6GHz carrier frequency.

Regression Progress to Evaluate Metal Scale Thickness using Microwave (전파를 이용한 도체 Scale 분석에 Regression Progress 기법 이용 연구)

  • Muhn, Sung-Jin;Park, Wee-Sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.1-5
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    • 2010
  • This paper deals with a method to measure the thickness of scale-layer, iron oxide formed on the surface of the rolling steel, using a dielectric lens antenna. The dielectric lens antenna has an independent characteristic with the frequency in the X-band and changes the spherical wave radiated from a horn antenna into a plane wave at the focusing point. Using this concept, we regard a scale-layer on the rolling steel as a dielectric-PEC(Perfect Electric Conductor) layer and apply a theoretical analysis of the normal-incident plane wave. To reduce the phase error arising from the use of the dielectric lens antenna, this paper utilizes a regression process algorithm. In comparison with the conventional iteration algorithm, the present algorithm led to a unique solution for the thickness of the scale-layer.

Adaptive Equalization Algorithm of Enhanced CMA using Minimum Disturbance Technique (최소 Disturbance 기법을 적용한 향상된 CMA 적응 등화 알고리즘)

  • Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.6
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    • pp.55-61
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    • 2014
  • This paper related with the ECMA (Enchanced CMA) algorithm performance which is possible to simultaneously compensation of the amplitude and phase by appling the minimum disturbance techniques in the CMA adatpve equalizer. The ECMA can improving the gradient noise amplification problem, stability and roburstness performance by the minimum disturbance technique that is the minimization of the equalizer tap weight variation in the point of squared euclidiean norm and the decision directed mode, and then the now cost function were proposed in order to simultaneouly compensation of amplitude and phase of the received signal with the minimum increment of computational operations. The performance of ECMA algorithm was compared to present MCMA by the computer simulation. For proving the performance, the recovered signal constellation that is the output of equalizer output signal and the residual isi and Maximum Distortion charateristic and MSE learning curve that are presents the convergence performance in the equalizer and the overall frequency transfer function of channel and equalizer were used. As a result of computer simulation, the ECMA has more better compensation capability of amplitude and phase in the recovered constellation, and the convergence time of adaptive equalization has improved compared to the MCMA.

A Study on Frequency Offset Compensation using 2-Phase Characteristic of Beacon Signal modulated by Satellite (위성 변조 비콘 신호의 2위상 특성을 이용한 주파수 오프셋 보상방법에 대한 연구)

  • Choi, Chul-Hee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.1
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    • pp.97-103
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    • 2018
  • In satellite communication, modulated beacon signal is spreaded by gold sequence and the modulated beacon is transmitted via linear phase modulation. Due to the difference in characteristics of the satellite and the receiver on the ground, frequency offset (FO) occurs. An existing modulated beacon receiver is a method of synchronizing the frequency of a modulated beacon signal using FFT(Fast Fourier Transform), which not only increases the delay and complexity in terms of system implementation but also has a separate circuit for compensating the phase difference due to FO and phase offset from FFT points. In order to overcome this problem, this paper proposes and analyzes a scheme for compensating and demodulating the coarse FO and phase offset at one time using the 2-phase shaped characteristics of the modulated beacon signal. Also, through the simulation, the modulation index suitable for the proposed method is analyzed and the appropriate cumulative number is also analyzed.

Design and Modeling of a DDS Driven Offset PLL with DAC (DAC를 적용한 DDS Driven Offset PLL모델링 및 설계)

  • Kim, Dong-Sik;Lee, Hang-Soo;Kim, Jong-Pil;Kim, Seon-Ju
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.5
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    • pp.1-9
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    • 2012
  • In this paper, we presents the modeling and implementation of the DDS(Direct Digital synthesizer) driven offset PLL(Pghase Locked Loop) with DAC(Digital Analog Converter) for coarse tune. The PLL synthesizer was designed for minimizing the size and offset frequency and DDS technique was used for ultra low noise and fast lock up time, also DAC was used for coarse tune. The output phase noise was analyzed by superposition theory with the phase noise transfer function and noise source modeling. the phase noise prediction was evaluated by comparing with the measured data. The designed synthesizer has ultra fast lock time within 6 usec and ultra low phase noise performance of -120 dBc/Hz at 10KHz offset frequency.

The Performance of Dual Structure CR-CMA Adaptive Equalizer for 16-QAM Signal (16-QAM 신호에 대한 이중 구조 CR-CMA 적응 등화기의 성능)

  • Yoon, Jae-Sun;Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.5
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    • pp.107-114
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    • 2012
  • In this paper, the concerned existing blind equalizer convergence rate and residual inter-symbol interference using constellation reduced and cost function by separation the real part and an imaginary part, the dual structure CR-CMA(constellation Reduction CMA). The CMA methed compensates amplitude but does no compensate phase, On the other hand, The CMA method compensates both the amplitude and the phase but it has the convergence rate problem, and the MCMA method is a way to solve the phase problem of CMA method compensates both the amplitude and the phase after respectively calculating the real part and imaginary part components. Proposal a new method that the dual structure of CR-CMA, the cost function and error function and respectively calculating the real part and imaginary part components can advantages by improving the CMA and the MCMA algorithms so that the amplitude and phase retrieval and constellation reduce the residual ISI and faster convergence rate and performance is good SER (Symbol Error Ratio) was confirmed by computer simulations.

A Reactive Power Compensation Monitoring System for Factory Electrical Installation Using Active Database (능동 데이터베이스 기반 무효전력 보상장치 감시제어 시스템)

  • Choi, Sang-Yule
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.4
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    • pp.189-194
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    • 2012
  • The main purpose of reactive power compensation monitoring system is to manage factory electrical installation efficiently by On-Off switching reactive power compensation equipment. The existing reactive power compensation monitoring system is only able to be managed by operator whenever electrical installation needed reactive power. Therefore, it may be possible for propagating the installation's faults when operator make the unexpected mistakes. To overcome the unexpected mistakes, in this paper, the author presents a reactive power compensation monitoring system for factory electrical installation using active database. by using active database production rule, stated system can minimize unexpected mistake and can operate centralized monitoring system efficiently. Test results on the five factory electrical installations show that performance is efficient and robust.