IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 6 , Issue 5
Showing 1-10 articles out of 10 articles from the selected issue
LETTER
  • Won-Joo Yun, Hyun-Woo Lee, Dongsuk Shin, Young-Jung Choi, Suki Kim
    2009 Volume 6 Issue 5 Pages 205-210
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    Coverage expandable current type code controlled DCC is presented, which has TDC-based range selector. The TDC-based range selector is composed of the TDC, the anti-harmonic lock block and the encoder/decoder. The code controlled current source has asymmetric current source to both current sinks for duty error correction and is controlled by binary digital codes. And the DCC amplifier controlled by binary codes has switches which are selected according to the input frequency range. With the frequency range information, the DCC amp can expand the cover range with suitable bit resolutions. The proposed circuit is designed and simulated with 54nm CMOS technology. The DCC circuit can correct at least duty error of 6% from 500MHz through 1.25GHz.
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  • Houng-Kuo Ku, Ting-Wei Hou
    2009 Volume 6 Issue 5 Pages 211-217
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    In this paper, we propose an efficient deinterlacing algorithm for the interpolation of interlaced images for digital display systems like LCD modules. Our method efficiently estimates the directional spatial correlations (horizontal, vertical, and diagonal directions) of neighboring pixels. The experiments on a variety of images and video sequences demonstrate that our proposed algorithm can accomplish better quantitative and visual quality than the FOI, ELA, and the low-complexity interpolation algorithm.
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  • Yong-Jin Lee, M. Atiquzzaman
    2009 Volume 6 Issue 5 Pages 218-222
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    Most current web application use small objects to increase the data transfer speed between server and client. This leads to completion of the object transfer while the TCP is still in the initial slow-start phase, which starts with an initial window size. SCTP, a new transport layer protocol, uses congestion control mechanism that is similar to that of TCP but complements TCP's deficiencies in web applications. This paper presents an analytical model of object transfer latency for HTTP over SCTP as a function of the initial window size during the initial slow-start phase. Validation of our model using experimental testbed shows that our model results are within 4% of experimental results.
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  • Muhammad Shafiq, Muhammad A. Shafiq
    2009 Volume 6 Issue 5 Pages 223-229
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    In Adaptive Inverse Control (AIC), parameters of the inverse are obtained using Indirect method. In this paper, we propose a direct method to design adaptive inverse controller. Direct Adaptive Inverse Control (DAIC) alleviates the adhocism in adaptive loop. Direct and Indirect methods for adaptive inverse control are compared using computer simulations. DAIC shows better results compared to Indirect AIC in terms of tracking.
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  • Pooya Davari, Hamid Hassanpour
    2009 Volume 6 Issue 5 Pages 230-236
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    This paper proposes a self-tuning feedforward active noise control (ANC) system with online secondary path modeling. The step-size parameters of the controller and modeling filters have crucial rule on the system performance. In literature, these parameters are adjusted by trial-and-error. In other words, they are manually initialized before system starting, which require performing extensive experiments to ensure the convergence of the system. Hence there is no guarantee that the system could perform well under different situations. In the proposed method, the appropriate values for the step-sizes are obtained automatically. Computer simulation results indicate the effectiveness of the proposed method.
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  • Hyun Sook Rhee, Willy Susilo, Hyun-Jeong Kim
    2009 Volume 6 Issue 5 Pages 237-243
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    Byun et al. firstly proposed off-line keyword guessing (KG)attacks and proved that some searchable public key encryption (PEKS)schemes are insecure against these attacks. They supposed an open problem on how to construct PEKS schemes secure against keyword guessing attacks. In this letter, we answer this question affirmatively.
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  • Yongsam Moon
    2009 Volume 6 Issue 5 Pages 244-248
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    For a multi-rate serial link, the proposed TX rise/fall time (tTR) control scheme enables tTR to be changed according to data rate. The main driver is split into multiple legs and each leg is controlled by its own pre-driver. All pre-drivers are biased on for the smallest tTR while some pre-drivers are biased off for large tTR. Due to RC delay among pre-drivers, the transition of a biased-off pre-driver's output occurs later but becomes overlapped with those of adjacent pre-drivers' outputs so that there is no stair-step waveform shown. The measurement results show that the driver has a sufficient tTR control range of around three times.
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  • Mohd H. Halmi, Mohamad Y. Alias, Chuah T. Chee
    2009 Volume 6 Issue 5 Pages 249-255
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    We present two decoding schemes for Alamouti space-time block codes (STBC) that do not require full knowledge of the received signal. Our schemes are able to decode signals directly from the received signal power, without knowledge of the signal amplitude and phase. This in turn allows for reduced susceptibility to fast fading and lower receiver complexity. Such decoding approach is not possible for the case of conventional Alamouti STBC scheme. It is shown that the proposed First Quadrant Transmission (FQT) is able to deliver the best performance on par with the conventional Alamouti STBC scheme even when the conventional scheme has full knowledge of the received signal. Our recommendations are based on the novel complex to real Alamouti STBC mapper and the sign ambiguity elimination method, both presented in this letter.
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  • Makoto Mita, Hiroshi Toshiyoshi
    2009 Volume 6 Issue 5 Pages 256-263
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    We report an equivalent circuit model for MEMS (microelectromechanical systems) electrostatic actuator using open-source circuit simulator Qucs (quite universal circuit simulator). Electrostatic force, equation of motion, and Kirchhoff's laws are implemented by using the EDD (equation defined device) function of Qucs. Mathematic integral operation in the equation of motion is interpreted into electrical circuits by using an ideal electrical capacitor that read input signal as current and returns accumulation result in terms of voltage. Seamless multi-physics mixed signal simulation between micro mechanics and electronics has become possible on the single platform of the circuit simulator.
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  • Hitoyuki Tagami, Norio Suzuki, Seiji Kozaki
    2009 Volume 6 Issue 5 Pages 264-269
    Published: 2009
    Released: March 10, 2009
    JOURNALS FREE ACCESS
    A composite clock and data recovery circuit based on oversampling and a gated oscillator is proposed. The reduction in the number of multi-phase clocks to be integrated in current silicon technology is discussed. The tolerance to pulse-width variation in a data packet is predicted numerically for an application to 10Gbit/s-based subscriber networks.
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