IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 6 , Issue 22
Showing 1-13 articles out of 13 articles from the selected issue
LETTER
  • Misagh Tavanpour, Ahmad Khademzadeh, Majid Janidarmian
    2009 Volume 6 Issue 22 Pages 1535-1541
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    Mapping of IP cores on a given platform is one of the three aspects of Network-on-Chip design. Mapping priority of IP cores is mostly based on a single communication in previously proposed algorithms. In this paper we present Chain-Mapping (CHMAP), as an algorithm for mapping cores onto a mesh-based Network-on-Chip architecture. The main aim of the algorithm is to produce chains of connected cores in order to introduce a new method to prioritize IP core which helps us to have more efficient mapping. Proposed algorithm and previous researches were compared on two real applications, i.e. Video object plan decoder (VOPD) and MPEG-4 and results were reported.
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  • Jongwook Lim, Yoon Joo Lee, Moo Young Kim
    2009 Volume 6 Issue 22 Pages 1542-1547
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    We investigate the theoretical and practical rate-distortion (R-D) performance of resolution-constrained quantization (RCQ) combined with lossless coding (RCQ+). Based on the high-rate theory, the required rate difference between RCQ and RCQ+, at a given mean distortion, is found to be the Kullback-Leibler distance (KLD) between the source probability density function (PDF) and its rateless centroid density function. Thus, the rate reduction in RCQ+ is diminished as vector dimensionality increases or as the source PDF approaches uniform density. In the experiments with Gaussian data, the R-D performance of high-rate derivation is verified. Huffman coding is implemented on top of the conventional RCQ methods such as ITU-T G.711 and G.722.2 speech coders, and the rate reduction with RCQ+ is found to be decreased for lower values of the KLD.
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  • Mahdi Alinaghizadeh Ardestani, Mohammad T. H. Beheshti
    2009 Volume 6 Issue 22 Pages 1548-1555
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    Real time network applications require effective mechanisms for managing Internet traffic in order to avoid or at least limit the level of congestion. We propose, design and analyze an Active Queue Manager (AQM) for controlling jitter using robust control theory. Here, we use an output feedback controller and this controller is based on discrete-time model of TCP. The natural properties of robust controller help us decreasing effect of model uncertainties and undesirable flows on performance of traffic control. The proposed Robust Discrete-Time Controller (RDTC) ensures the maintenance of the router's queue length at the desired value. We used ns2 for simulation of controller performance and the results obtained verify the validity of the algorithm.
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  • Bing Li, Mei-qiang Shi
    2009 Volume 6 Issue 22 Pages 1556-1561
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    In this paper, we proposed a novel audio video synchronization compression approach based on H.264/AVC, which is audio is embedded into quantized DCT coefficients of video in the encoder utilizing the parity properties of coefficients, then audio and video signals are compressed simultaneously. Different from the traditional methods, the proposed approach realizes the synchronization between video and audio in the coding layer. We've verified the synchronization processing method based on H.264/AVC using JM Model and experimental results show that this method does not increase the amount of data, and audio signal can be extracted without distortion. At the same time the algorithm has little effect on the quality of video.
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  • Hisa-Aki Tanaka, Hiroya Nakao, Kenta Shinohara
    2009 Volume 6 Issue 22 Pages 1562-1568
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    A novel, distributed timing allocation method [2, 3, 4, 5] has been proposed for packet collision avoidance in wireless sensor networks recently. In this paper, this proposed method is theoretically examined, and a hidden self-organization mechanism is unveiled. As the result, some important fundamental questions regarding this method are reasonably resolved. Namely, our present analysis provides a definite criterion, as to when it functions properly for densely connected networks in real noisy environments.
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  • Takao Watanabe, Toshimichi Shintani, Kazuo Ono, Toshiyuki Mine
    2009 Volume 6 Issue 22 Pages 1569-1575
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    A fundamental study on a digital-data-preservation system featuring a LED-light computer tomography (CT) was successfully performed. With this system, 17 × 17 × 17-bit test data (recorded by femtosecond laser in a 5-mm-thick, flat synthetic fused silica sample) is extracted from 27projections at different angles. The results of annealing tests at 973K (700°C) and 1173K (900°C) imply that the system has the potential for achieving archival lifetime of over one-hundred-thousand years at room temperature. The storage density could be as large as 16.6Mbytes/cm3 if bit pitch is minimized to 10µm.
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  • Jun Ogasawara, Koichi Narahara
    2009 Volume 6 Issue 22 Pages 1576-1581
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    Composite right- and left-handed (CRLH) transmission lines with regularly spaced Schottky varactors are characterized for propagation of short envelope pulses. Due to strong dispersion, a short pulse cannot travel on a conventional CRLH line without distortion. This distortion is compensated for by the effects of Schottky varactors such that the line supports solitonic pulses, whose pulse width depends on the carrier frequency. It then becomes possible to find carrier frequencies at which the pulse width becomes minimal. This article describes the design criteria for propagating short envelope pulses in the lines.
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  • Mina Amirmazlaghani, Farshid Raissi
    2009 Volume 6 Issue 22 Pages 1582-1586
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    Using spice 9.3, we have modeled (I-V) characteristics of a Modified Field Effect Diode (M-FED) with gate length of 75nm and oxide thickness of 10nm. An SRAM cell (Register) has been designed with the simulated M-FED and has been compared to an SOI-MOSFET based circuit. Simulation results demonstrate that clock frequency applied to a memory cell which is designed with M-FED is more than 2 orders of magnitude larger than that of a comparable SOI-MOSFET, while the access time of the M-FED based memory cell is three orders of magnitude less than the comparable SOI-MOSFET.
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  • Hee Joon Park, Sang Hyo Woo, Zia Mohy Ud Din, Myoung Nam Kim, Jin Ho C ...
    2009 Volume 6 Issue 22 Pages 1587-1594
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    The aim of this study is to design and implement a wireless transcutaneous electrical nerve stimulator (TENS) that is controlled by a smart phone. The proposed TENS can be attached to the human arm with the help of an arm band for providing electrical stimuli via a disposable electrode. These stimuli help suppress pain and increase skin temperature, and the electrical parameters of the stimuli are controlled with the help of a smart phone. For implementing a small (21 × 20 mm) and electrically safe TENS, a modified boost converter, which continuously monitors the peak current output to ensure the electrical safety, is used. Simple in vivo experiments are conducted to identify the pain control ability and skin temperature increment in the human arm.
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  • Wonseok Oh, Praveen Nadimpalli, Dharma Kadam
    2009 Volume 6 Issue 22 Pages 1595-1601
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    In this work, a fast turn-on settling low dropout regulator (LDO) with current limiter is presented. Dynamically operating the proposed current limiter using a decent current comparator protects the IC from any damage when an overload condition occurs or the output of the regulator is shorted. A novel low pass filter associated with voltage reference circuit, which provides highly filtered reference voltage and fast settling time, is implemented to minimize output noise due to voltage reference noise. The LDO with proposed low pass filter and current limiter has been implemented in a 0.6µm n-well CMOS process. The LDO dissipates 65µA quiescent current at 150mA full load condition and its output noise is 407.8nV/√Hz at 100Hz. Turn-on settling time of the LDO is 45µsec and threshold current of the current limiter is set to 230mA of output load current.
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  • Ji-Ho Cho, Remo Ziegler, Markus Gross, Kwan H. Lee
    2009 Volume 6 Issue 22 Pages 1602-1607
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    In this paper, we propose an automatic alpha matting method that improves the quality of alpha matte using a depth camera. Depth camera obtains both visual and depth information of moving objects in real time. Our matting method improves existing natural alpha matting methods by adding depth information. Experimental results demonstrate that our matting method generates better results than the previous approaches.
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  • Ifong Wu, Shinobu Ishigami, Kaoru Gotoh, Yasushi Matsumoto
    2009 Volume 6 Issue 22 Pages 1608-1614
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    The effect of a low dielectric block placed at the tip of a GTEM cell on the electric field was numerically and experimentally investigated from 1-16GHz. The block increased the electric field strength when placed at the GTEM cell tip. Comparison of the simulation and measurement results revealed good agreement between them. However, we also confirmed that when the low dielectric block was installed in a location far from the GTEM cell tip, it had little influence on the electric field, regardless of its size. It is concluded that a low dielectric material increases the electric field strength when it is placed at the tip of a GTEM cell.
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  • Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa
    2009 Volume 6 Issue 22 Pages 1615-1620
    Published: 2009
    Released: November 25, 2009
    JOURNALS FREE ACCESS
    We demonstrate 10Gbit/s transmission over a 5km photonic crystal fiber (PCF) in the 1.1µm band using a directly-modulated single-mode vertical cavity surface emitting laser (VCSEL).A combination of PCF and VCSEL enables us to achieve high-speed transmission at a low cost and with a simple configuration that does not employ optical modulators or amplifiers. Furthermore, the transmission distance was extended to 14km by using an ytterbium-doped fiber amplifier (YDFA), and a power penalty-free transmission was successfully achieved.
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