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12281-12300hit(20498hit)

  • New Encoding /Converting Methods of Binary GA/Real-Coded GA

    Jong-Wook KIM  Sang Woo KIM  

     
    PAPER-Systems and Control

      Vol:
    E88-A No:6
      Page(s):
    1554-1564

    This paper presents new encoding methods for the binary genetic algorithm (BGA) and new converting methods for the real-coded genetic algorithm (RCGA). These methods are developed for the specific case in which some parameters have to be searched in wide ranges since their actual values are not known. The oversampling effect which occurs at large values in the wide range search are reduced by adjustment of resolutions in mantissa and exponent of real numbers mapped by BGA. Owing to an intrinsic similarity in chromosomal operations, the proposed encoding methods are also applied to RCGA with remapping (converting as named above) from real numbers generated in RCGA. A simple probabilistic analysis and benchmark with two ill-scaled test functions are carried out. System identification of a simple electrical circuit is also undertaken to testify effectiveness of the proposed methods to real world problems. All the optimization results show that the proposed encoding/converting methods are more suitable for problems with ill-scaled parameters or wide parameter ranges for searching.

  • A Simple Bit Allocation Scheme Based on Adaptive Coding for MIMO-OFDM Systems with V-BLAST Detector

    Jongwon KIM  Sanhae KIM  Min-Cheol HONG  Yoan SHIN  

     
    LETTER

      Vol:
    E88-A No:6
      Page(s):
    1533-1537

    We present a simple bit allocation scheme based on adaptive coding for MIMO-OFDM (Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing) systems with V-BLAST (Vertical-Bell laboratories LAyered Space-Time) detector. The proposed scheme controls the code rate of the channel coding and assigns the same modulation and coding to the set of selected sub-channels, which greatly reduces the feedback burden while achieving good performance. Simulation results show that the proposed scheme with minimal feedback provides significant performance improvement over other systems.

  • A Method of Guaranteeing Image-Quality for Quantization-Based Watermarking Using a Nonorthogonal Transformation

    Masaaki FUJIYOSHI  Osamu WATANABE  Hitoshi KIYA  

     
    PAPER

      Vol:
    E88-A No:6
      Page(s):
    1434-1442

    This paper proposes a quantization-based image-quality guaranteed watermarking (IQGW) method using a nonorthogonal discrete wavelet transformation. An IQGW method generates watermarked images of a desired image quality for any image, neither with trial and error nor with image-dependent parameters. To guarantee the image-quality, the proposed method adjusts the energy of the watermark sequence to be embedded based on the relationship between a nonorthogonally transformed domain and the spatial domain for the signal energy. This proposed method extracts the embedded watermark by quantization of watermarked coefficients, no reference image, thus, is required. In addition, it is capable of controlling the objective and subjective image-quality of a watermarked image independently. With features mentioned above, the proposed method is suitable for real-time embedding of Motion JPEG 2000 videos. Moreover, it is able to fuse quantization- and correlation-based watermarking.

  • Analysis of Reflector and Horn Antennas Using Adaptive Integral Method

    Wei-Bin EWE  Le-Wei LI  Qun WU  Mook-Seng LEONG  

     
    PAPER

      Vol:
    E88-B No:6
      Page(s):
    2327-2333

    This paper presents an analysis of electrically large antennas using the adaptive integral method (AIM). The arbitrarily shaped perfectly conducting surfaces are modeled using triangular patches and the associated electric field integral equation (EFIE) is solved for computing the radiation patterns of these antennas. The method of moments (MoM) is used to discretize the integral equations and the resultant matrix system will be solved by an iterative solver. The AIM is employed in the iterative solver to speed up the matrix-vector multiplication and to reduce the memory requirement. As specific applications, radiation patterns of parabolic reflectors and X-band horns are computed using the proposed method.

  • Extraction of Transformation Rules from UML Diagrams to SpecC

    Tetsuro KATAYAMA  

     
    PAPER

      Vol:
    E88-D No:6
      Page(s):
    1126-1133

    Embedded systems are used in broad fields. They are one of the indispensable and fundamental technologies in a highly informative society in recent years. As embedded systems are large-scale and complicated, it is prosperous to design and develop a system LSI (Large Scale Integration). The structure of the system LSI has been increasing complexity every year. The degree of improvement of its design productivity has not caught up with the degree of its complexity by conventional methods or techniques. Hence, an idea for the design of a system LSI which has the flow of describing specifications of a system in UML (Unified Modeling Language) and then designing the system in a system level language has already proposed. It is important to establish how to convert from UML to a system level language in specification description or design with the idea. This paper proposes, extracts and verifies transformation rules from UML to SpecC which is one of system level languages. SpecC code has been generated actually from elements in diagrams in UML based on the rules. As an example to verify the rules, "headlights control system of a car" is adopted. SpecC code has been generated actually from elements in diagrams in UML based on the rules. It has been confirmed that the example is executed correctly in simulations. By using the transformation rules proposed in this paper, specification and implementation of a system can be connected seamlessly. Hence, it can improve the design productivity of a system LSI and the productivity of embedded systems.

  • 64-Bit High-Performance Power-Aware Conditional Carry Adder Design

    Kuo-Hsing CHENG  Shun-Wen CHENG  

     
    PAPER-Integrated Electronics

      Vol:
    E88-C No:6
      Page(s):
    1322-1331

    The conditional sum adder (CSA) has been shown to outperform other adders applied in high-speed applications. This investigation proposes a modified CSA called the conditional carry adder (CCA). Based on the proposed adder architecture, six 64-bit hybrid dual-threshold CCAs for power-aware applications were discussed. Architectural modification of the CCA raises the operation speed, decreases the power dissipation, and lowers the hardware overhead. The proposed 64-bit CCA can decrease the number of multiplexers and internal nodes in the adder design by around 27% compared to the 64-bit CSA. Furthermore, components on critical paths use a low threshold voltage to accelerate the speed of operation, and other components use the normal threshold voltage to save power. This feature is very useful in implementing power-aware arithmetic systems. One of the proposed circuits has the lowest power-delay product and energy-delay product. The hybrid circuit represents a fine compromise between power and performance. Its power efficiency is better than that of the single threshold voltage circuit designs.

  • A 24-Gsps 3-Bit Nyquist ADC Using InP HBTs for DSP-Based Electronic Dispersion Compensation

    Hideyuki NOSAKA  Makoto NAKAMURA  Kimikazu SANO  Minoru IDA  Kenji KURISHIMA  Tsugumichi SHIBATA  Masami TOKUMITSU  Masahiro MURAGUCHI  

     
    PAPER-Optical

      Vol:
    E88-C No:6
      Page(s):
    1225-1232

    A 3-bit flash analog-to-digital converter (ADC) for electronic dispersion compensation (EDC) was developed using InP HBTs. Nyquist operation was confirmed up to 24 Gsps, which enables oversampling acquisition for 10 Gbit/s non-return-to-zero (NRZ) signals. The ADC can also be operated at up to 37 Gsps for low input frequencies. To reduce aperture jitter and achieve a wide band of over 7 GHz, an analog input signal for all pre-amplifiers and a clock signal for all latched comparators are provided as traveling waves through coplanar transmission lines. EDC was demonstrated by capturing a 10-Gbit/s pseudo-random bit stream (PRBS) with the waveform degraded by polarization-mode dispersion (PMD). By using the captured data, we confirmed that a calculation of a transversal filter mitigates PMD.

  • Combiner-Based MOS OTAs

    Koichi TANNO  Kenya KONDO  Okihiko ISHIZUKA  Takako TOYAMA  

     
    LETTER-Analog Signal Processing

      Vol:
    E88-A No:6
      Page(s):
    1622-1625

    In this letter, two kinds of MOS operational transconductance amplifiers (OTAs) based on combiners are presented. Each OTA has the following advantages; one of the proposed OTAs (OTA-1) can be operated at low supply voltage and the other OTA (OTA-2) has wide bandwidth. Through HSPICE simulations with a standard 0.35 µm CMOS device parameters, the operation under the supply voltage of 1.5 V for OTA-1 and the -3 dB bandwidth of several gigahertz for OTA-2 are confirmed.

  • Parallel Image Convolution Processing with Replicas in a Network of Workstations

    Masayoshi ARITSUGI  Hiroki FUKATSU  Yoshinari KANAMORI  

     
    PAPER-Database

      Vol:
    E88-D No:6
      Page(s):
    1199-1209

    Data accessed by many sites are replicated in distributed environments for performance and availability. In this paper, replication schemes are examined in parallel image convolution processing. This paper presents a system architecture that we have developed with CORBA (Common Object Request Broker Architecture) for the processing. Employing CORBA enables us to make use of a cluster of workstations, each of which has a different level of computing power. The paper also describes a parallel and distributed image convolution processing model using replicas stored in a network of workstations, and reports some experimental results showing that our analytical model can agree with practical situations.

  • Attenuation Characteristics of the SAR in a COST244 Phantom with Different EM Source Locations and Sizes

    Shoichi KAJIWARA  Atsushi YAMAMOTO  Koichi OGAWA  Akihiro OZAKI  Yoshio KOYANAGI  

     
    PAPER

      Vol:
    E88-B No:6
      Page(s):
    2391-2400

    This paper addresses the variation of the attenuation characteristics of the Specific Absorption Rate (SAR) in a lossy medium as a function of the distance between an antenna and the medium with different EM-source sizes. Analysis and measurements were performed using a dipole antenna at 900 MHz and a COST244 cubic phantom. From this, an empirical equation has been derived, representing the attenuation characteristics of the SAR. The equation takes into consideration an energy loss due to the spatial spread of electromagnetic waves. In the case where an antenna is placed more than λ/2π away from the medium, the attenuation characteristics of the SAR are those obtained from plane waves in the lossy medium. In the case where a half-wavelength dipole antenna is located close to the medium, at a distance of less than λ/2π, the attenuation characteristics of the SAR are calculated from an equation that includes a loss caused by the spread of energy as a cylindrical wave. Moreover, when the length of antenna is short, it is found that a spatial attenuation factor appropriate to a spherical wave should be taken into account.

  • Three Beam Switched Top Loaded Monopole Antenna

    Naobumi MICHISHITA  Yuji NAKAYAMA  Hiroyuki ARAI  Kohei MORI  

     
    PAPER

      Vol:
    E88-B No:6
      Page(s):
    2291-2296

    The three beam-switched top-loaded antenna is suited to be applied to a wireless local area network to switch the radiation pattern by arranging several unidirectional antennas. In this paper, a three beam switched top loaded monopole antenna is proposed to realize its small size and planar structure. Three top loaded monopole antennas are arranged around a parasitic hexagonal patch at intervals of 120 degrees. The feed element is selected by the switching device to switch the radiation pattern. This antenna allows for reduction in the number of elements as well as downsizing. The front to back ratio (F/B) becomes 23 dB by selecting suitable parameters.

  • An Effective Testing Method for Hardware Related Fault in Embedded Software

    Takeshi SUMI  Osamu MIZUNO  Tohru KIKUNO  Masayuki HIRAYAMA  

     
    PAPER

      Vol:
    E88-D No:6
      Page(s):
    1142-1149

    According to the proliferation of ubiquitous computing, various products which contain large-size embedded software have been developed. One of most typical features of embedded software is concurrency of software and hardware factors. That is, software has connected deeply into hardware devices. The existence of various hardware make quality assurance of embedded software more difficult. In order to assure quality of embedded software more effectively, this paper discusses features of embedded software and an effective method for quality assurance for embedded software. In this paper, we first analyze a failure distribution of embedded software and discuss the effects of hardware devices on quality of embedded software. Currently, in order to reduce hardware related faults, huge effort for testing with large number of test items is required. Thus, one of the most important issues for quality assurance of embedded software is how to reduce the cost and effort of software testing. Next, focusing on hardware constraints as well as software specifications in embedded software, we propose an evaluation metrics for determinating important functions for quality of embedded software. Furthermore, by referring to the metrics, undesirable behaviors of important functions are identified as root nodes of fault tree analysis. From the result of case study applying the proposed method to actual project data, we confirmed that test items considering the property of embedded software are constructed. We also confirmed that the constructed test items are appropriate to detect hardware related faults in embedded systems.

  • Constructing a Bayesian Belief Network to Predict Final Quality in Embedded System Development

    Sousuke AMASAKI  Yasunari TAKAGI  Osamu MIZUNO  Tohru KIKUNO  

     
    PAPER

      Vol:
    E88-D No:6
      Page(s):
    1134-1141

    Recently, software development projects have been required to produce highly reliable systems within a short period and with low cost. In such situation, software quality prediction helps to confirm that the software product satisfies required quality expectations. In this paper, by using a Bayesian Belief Network (BBN), we try to construct a prediction model based on relationships elicited from the embedded software development process. On the one hand, according to a characteristic of embedded software development, we especially propose to classify test and debug activities into two distinct activities on software and hardware. Then we call the proposed model "the BBN for an embedded software development process". On the other hand, we define "the BBN for a general software development process" to be a model which does not consider this classification of activity, but rather, merges them into a single activity. Finally, we conducted experimental evaluations by applying these two BBNs to actual project data. As the results of our experiments show, the BBN for the embedded software development process is superior to the BBN for the general development process and is applicable effectively for effective practical use.

  • Turbo Transceivers for MIMO Wireless Communications and Their Performance Verification via Multi-Dimensional Channel Sounding

    Tadashi MATSUMOTO  Reiner S. THOMA  

     
    INVITED PAPER

      Vol:
    E88-B No:6
      Page(s):
    2239-2251

    The discovery of the Turbo codes has driven research on the creation of new signal detection concepts that are, in general, referred to as the Turbo approach. Recently, this approach has made a drastic change in creating signal detection techniques and algorithms such as equalization of inter-symbol interference (ISI) experienced by broadband single carrier signaling over mobile radio channels. A goal of this paper is to provide readers with broad views and knowledge of the Turbo concept-based Multiple-Input Multiple-Output (MIMO) signal transmission techniques. How the techniques have been developed in various applications and how they perform in real-field environments are introduced.

  • A Basic Study on a Very Low-Level DC Current Amplifier Using a Switched-Capacitor Circuit

    Hiroki HIGA  Naoki NAKAMURA  Ikuo NAKAMURA  

     
    PAPER

      Vol:
    E88-A No:6
      Page(s):
    1394-1400

    In order to miniaturize a very low-level dc current amplifier and to speed up its output response speed, we proposed to employ the switched-capacitor circuit (SCC) as its negative feedback circuit, instead of the conventionally used high-ohmage resistor. However, in the case of using SCC, the output waveform had unnecessary components. To decrease the effect of these components and to speed up the response speed, we used a switched-capacitor filter (SCF), an offset controller, and a positive feedback circuit. As a result, we demonstrated that it was useful to use the amplifier using the SCC.

  • Optimization in the Shortest Path First Computation for the Routing Software GNU Zebra

    Vincenzo ERAMO  Marco LISTANTI  Nicola CAIONE  Igor RUSSO  Giuseppe GASPARRO  

     
    LETTER-Switching for Communications

      Vol:
    E88-B No:6
      Page(s):
    2644-2649

    Routing protocols are a critical component in IP networks. Among these, the Open Shortest Path First (OSPF) has been a widely used routing protocol in IP networks for some years. Beside dedicated hardware, a great interest on routing systems based on open software is raising among Internet Service Providers. Many open source implementations of this protocol have been developed, among which GNU Zebra is one of the most complete. In this paper we perform a study of the performances of the Shortest Path First computation in GNU Zebra, as prescribed by the Internet Engineering Task Force, and we provide a comparison between a Cisco 2621 access router and a PC-based router equipped with routing software GNU Zebra. Moreover we describe a set of modifications made on the GNU Zebra code in order to optimize some processes, whose algorithms were not efficient and whose experimental measures had showed a lack of optimization, thus finally obtaining performances better than the one measured on commercial systems.

  • Dual-Band Mixer Design

    Mei-Fen CHOU  Kuei-Ann WEN  Chun-Yen CHANG  

     
    LETTER-RF

      Vol:
    E88-C No:6
      Page(s):
    1280-1284

    This paper presents a dual-band mixer equipped with a dual-band load using current combine technique to minimize chip area by sharing inductors for each frequency band. A systematic design methodology for the current combine load based on parasitic effect considerations is also developed. By following the proposed design procedure, the load inductance and combine capacitance for the dual-band mixer can be easily determined. A 2.4/5.2-GHz CMOS mixer design has been implemented to demonstrate the feasibility of the design technique.

  • A Novel Image Enhancement Algorithm for a Small Target Detection of Panoramic Infrared Imagery

    Ju-Young KIM  Ki-Hong KIM  Hee-Chul HWANG  Duk-Gyoo KIM  

     
    LETTER

      Vol:
    E88-A No:6
      Page(s):
    1520-1524

    A novel image enhancement algorithm that can efficiently detect a small target of panoramic infrared (IR) imagery is proposed. Image enhancement is the first step for detecting and recognizing a small target in the IR imagery. The essence of the proposed algorithm is to utilize the independent histogram equalization (HE) separately over two sub-images obtained by decomposing the given image through the statistical hypothesis testing (SHT). Experimental results show that the proposed algorithm has better discrimination and lower false alarm rate than the conventional algorithms.

  • New Method of Moving Control for Wireless Endoscopic Capsule Using Electrical Stimuli

    Hee-Joon PARK  Jyung-Hyun LEE  Yeon-Kwan MOON  Young-Ho YOON  Chul-Ho WON  Hyun-Chul CHOI  Jin-Ho CHO  

     
    PAPER

      Vol:
    E88-A No:6
      Page(s):
    1476-1480

    In order to control the moving speed of an endoscopic capsule in the human intestine, electrical stimulation method is proposed in this paper. The miniaturized endoscopic capsule with the function of various electrical stimulations has been designed and implemented. An in-vivo animal experiment has been performed to show the ability of controlling the movement speed of the endoscopic capsule according to the level of electrical stimulation. In-vivo experiments were performed by inserting the implemented capsule into a pig's intestinal tract. From the experimental results, the activation of peristaltic movement and the relationship between the moving speed of capsule and the stimulation amplitude could be found. It is shown that the moving speed of capsule in the intestine can be controlled by adjustment of the stimulation level applied in the capsule electrodes. The results of the in-vivo experiment verify that the degree of contraction in the intestinal tract is closely related with the level of stimulating electrical voltage, suggesting that the moving speed of capsule in the human gastrointestinal tract can be controlled by externally adjusting the amplitude of stimulating pulse signal.

  • Fast Algorithms for Solving Toeplitz and Bordered Toeplitz Matrix Equations Arising in Electromagnetic Theory

    Min-Hua HO  Mingchih CHEN  

     
    PAPER-Electromagnetic Theory

      Vol:
    E88-C No:6
      Page(s):
    1295-1303

    In many electromagnetic field problems, matrix equations were always deduced from using the method of moment. Among these matrix equations, some of them might require a large amount of computer memory storage which made them unrealistic to be solved on a personal computer. Virtually, these matrices might be too large to be solved efficiently. A fast algorithm based on a Toeplitz matrix solution was developed for solving a bordered Toeplitz matrix equation arising in electromagnetic problems applications. The developed matrix solution method can be applied to solve some electromagnetic problems having very large-scale matrices, which are deduced from the moment method procedure. In this paper, a study of a computationally efficient order-recursive algorithm for solving the linear electromagnetic problems [Z]I = V, where [Z] is a Toeplitz matrix, was presented. Upon the described Toeplitz matrix algorithm, this paper derives an efficient recursive algorithm for solving a bordered Toeplitz matrix with the matrix's major portion in the form of a Toeplitz matrix. This algorithm has remarkable advantages in reducing both the number of arithmetic operations and memory storage.

12281-12300hit(20498hit)