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[Keyword] CTI(8214hit)

5721-5740hit(8214hit)

  • Millimeter-Wave Processing of LaCrO3 and LaNiO3 Perovskites Using 28 GHz Frequency

    Hirotsugu TAKIZAWA  Masato IWASAKI  

     
    PAPER-Millimeter-Wave Heating

      Vol:
    E86-C No:12
      Page(s):
    2469-2473

    Both Cr2O3 and NiO absorb 28 GHz milli-meter-wave energy well and this strong coupling with millimeter-waves can be used to promote a chemical reaction with La2O3 to form perovskite-type LaCrO3 or LaNiO3 ceramics. In La2O3-Cr2O3 system, the reaction proceeded rapidly and single phase LaCrO3 could be synthesized within 15 min even at lower temperature (400) as compared to conventional synthesis (T > 800). In the case of LaNiO3, the reaction proceeded rapidly in the early stage of heating (t < 15 min), but not completed even after prolonged millimeter-wave irradiation. The results suggest an importance of millimeter-wave penetration depth, especially for processing of conductive materials.

  • Study of Simulation for High Sensitivity Non-invasive Measurement of Blood Sugar Level in Millimeter Waves

    Yong GUAN  Yoshio NIKAWA  Eiji TANABE  

     
    PAPER-Medical Application

      Vol:
    E86-C No:12
      Page(s):
    2488-2493

    Development of non-invasive techniques to measure blood sugar level is strongly required. The application of millimeter waves has a great potentiality to realize the measuring technique. Nevertheless, the practical method of the technique is not yet reported. In this paper, a new technique is proposed to measure blood sugar level using millimeter waves. The technique proposed here is very rapid and safety way to obtain blood sugar level.

  • Approximation Formula Approach for the Efficient Extraction of On-Chip Mutual Inductances

    Atsushi KUROKAWA  Takashi SATO  Hiroo MASUDA  

     
    PAPER-Parasitics and Noise

      Vol:
    E86-A No:12
      Page(s):
    2933-2941

    We present a new and efficient approach for extracting on-chip mutual inductances of VLSI interconnects by applying approximation formulae. The equations are based on the assumption of filaments or bars of finite width and zero thickness and are derived through Taylor's expansion of the exact formula for mutual inductance between filaments. Despite the assumption of uniform current density in each of the bars, the model is sufficiently accurate for the interconnections of current and future LSIs because the skin and proximity effects do not affect most wires. Expression of the equations in polynomial form provides a balance between accuracy and computational complexity. These equations are mapped according to the geometric structures for which they are most suitable in minimizing the runtime of inductance calculation while retaining the required accuracy. Within geometrical constraints, the wires are of arbitrary specification. Results of a comprehensive evaluation based on the ITRS-specified global wiring structure for 2003 shows that the inductance values were extracted by using the proposed approach, and they were within several percent of the values obtained by using commercial three-dimensional (3-D) field solvers. The efficiency of the proposed approach is also demonstrated by extraction from a real layout design that has 300-k interconnecting segments.

  • Characteristics of GaAs HEMTs with Flip-Chip Interconnections

    Naoko ONO  Fumio SASAKI  Kazuhiro ARAI  Hiroyuki YOSHINAGA  Yuji ISEKI  

     
    PAPER-Amplifier

      Vol:
    E86-C No:12
      Page(s):
    2452-2461

    A GaAs HEMT with flip-chip interconnections using a suitable transmission line has been developed. The underfill resin, which was not used for the conventional flip-chip interconnection structure, was adopted between GaAs chip and assembly substrate to obtain high reliability. The underfill resin is effective in relaxing the thermal stress between the chip and the substrate and in encapsulating the chip. There are various possible ground current paths for the GaAs chip in the structure with flip-chip interconnections. An actual ground current path is determined depending on the transmission line type for the chip. For an active device, it is important to utilize an assembly structure capable of realizing excellent high-frequency characteristics. In addition, each transmission line for the chip has its own transmission characterizations such as characteristic impedance. Therefore, it is necessary to choose a suitable transmission line for the chip. We evaluated the high-frequency characteristics of the HEMT test element groups (TEGs) with flip-chip interconnection for three types of transmission lines: with a microstrip line (MSL), with a coplanar waveguide (CPW), and with an inverted microstrip line (IMSL). All three types of TEGs had similar values of a maximum available power gain (MAG) at 30 GHz. However, it was found that the IMSL-type TEG, which had superior characteristics in high-frequency ranges of more than 30 GHz, is the most suitable type. The IMSL-type TEG had an MAG of 10.02 dB and a Rollett stability factor K of 1.20 at 30 GHz.

  • A Note on Diffraction and Equivalent Admittance Properties of a Transverse Slit in a Parallel Plate Waveguide Filled with a Homogeneous Dielectric

    Jong-Ig LEE  Ji-Hwan KO  Young-Ki CHO  

     
    PAPER-Antenna and Propagation

      Vol:
    E86-B No:12
      Page(s):
    3600-3605

    This study examines a slitted parallel plate waveguide (PPW) from the perspective of diffraction and equivalent circuit representation for a narrow slit and radiation, including the surface wave effect, from a wide slit. The fundamental differences between the diffraction and equivalent admittance properties of the slit discontinuities in typical microstrip and waveguide structures are considered by comparing how the waveguide heights of the PPW and dielectric constants filling the inside of the PPW correspond to those of the two structures, respectively.

  • A Dynamically Adaptive Hardware on Dynamically Reconfigurable Processor

    Hideharu AMANO  Akiya JOURAKU  Kenichiro ANJO  

     
    INVITED PAPER

      Vol:
    E86-B No:12
      Page(s):
    3385-3391

    A framework of dynamically adaptive hardware mechanism on multicontext reconfigurable devices is proposed, and as an example, an adaptive switching fabric is implemented on NEC's novel reconfigurable device DRP (Dynamically Reconfigurable Processor). In this switch, contexts for the full crossbar and alternative hadware modules, which provide larger bandwidth but can treat only a limited pattern of packet inputs, are prepared. Using the quick context switching functionality, a context for the full crossbar is replaced by alternative contexts according to the packet inputs pattern. If the context corresponding to requested alternative hadware modules is not inside the chip, it is loaded from outside chip to currently unused context memory, then replaced with the full size crossbar. If the traffic includes a lot of packets for specific destinations, a set of contexts frequently used in the traffic is gathered inside the chip like a working set stored in a cache. 4 4 mesh network connected with the proposed adaptive switches is simulated, and it appears that the latency between nodes is improved three times when the traffic between neighboring four nodes is dominant.

  • Verification of Synchronization in SpecC Description with the Use of Difference Decision Diagrams

    Thanyapat SAKUNKONCHAK  Satoshi KOMATSU  Masahiro FUJITA  

     
    PAPER-Logic and High Level Synthesis

      Vol:
    E86-A No:12
      Page(s):
    3192-3199

    SpecC language is designated to handle the design of entire system from specification to implementation and of hardware/software co-design. Concurrency is one of the features of SpecC which expresses the parallel execution of processes. Describing the systems which contain concurrent behaviors would have some data exchanging or transferring among them. Therefore, the synchronization semantics (notify/wait) of events should be incorporated. The actual design, which is usually sophisticated by its characteristic and functionalities, may contain a bunch of event synchronization codes. This will make the design difficult and time-consuming to verify. In this paper, we introduce a technique which helps verifying the synchronization of events in SpecC. The original SpecC code containing synchronization semantics is parsed and translated into a Boolean SpecC code. The difference decision diagrams (DDDs) is used to verify for event synchronization on Boolean SpecC code. The counter examples for tracing back to the original source are given when the verification results turn out to be unsatisfied. Here we also introduce idea on automatically refinement when the results are unsatisfied and preset some preliminary results.

  • A Retargetable Simulator Generator for DSP Processor Cores with Packed SIMD-type Instructions

    Nozomu TOGAWA  Kyosuke KASAHARA  Yuichiro MIYAOKA  Jinku CHOI  Masao YANAGISAWA  Tatsuo OHTSUKI  

     
    PAPER-Simulation Accelerator

      Vol:
    E86-A No:12
      Page(s):
    3099-3109

    A packed SIMD type operation or a SIMD operation is n-parallel b/n-bit sub-operations executed by the modified n-bit functional unit. Such a functional unit is called a SIMD functional unit and a processor core which can execute SIMD operations is called a SIMD processor core. SIMD operations can be effectively applied to image processing applications. This paper focuses on hardware/software cosynthesis of SIMD processor cores and particularly proposes a new simulator generator which simulates pipelined instructions for a SIMD processor. Generally, a SIMD functional unit has many options and then we can have so many different SIMD functional unit instances. However, since our hardware/software cosynthesis system synthesizes a special-purpose processor core for an input application program, it uses very limited SIMD functional unit instances. In the proposed approach, we consider a SIMD operation to be a set of SIMD sub-operations. By adding up the appropriate SIMD sub-operations, we construct a single SIMD operation. Then a SIMD functional unit behavior can be characterized by a collection of SIMD operations. This approach has the advantage that: if we have a small number of behavior libraries for SIMD sub-operations, we can instantiate a particular SIMD functional unit behavior. Experimental results demonstrate the effectiveness of the proposed approach.

  • Representative Frequency for Interconnect R(f)L(f)C Extraction

    Akira TSUCHIYA  Masanori HASHIMOTO  Hidetoshi ONODERA  

     
    PAPER-Parasitics and Noise

      Vol:
    E86-A No:12
      Page(s):
    2942-2951

    This paper discusses the frequency to extract RLC values from interconnects. In circuit design, frequency-independent equivalent circuit is widely used, and many design and analysis techniques based on this equivalent circuit are proposed so far. However in reality, characteristics of interconnects are frequency-dependent. Also pulse waveforms in digital circuits contain multiple frequency components. The frequency used for RLC extraction affects the accuracy of interconnect characterization, and hence careful determination of extraction frequency is critical. We propose a representative frequency for RLC extraction. Conventionally, representative frequencies are determined by input pulse. The proposed method decides the representative frequency based on the interconnect length, whereas conventional representative frequencies are determined by input pulse shape, period and patterns. We verify that the extraction at the proposed frequency provides the most accurate transition waveform against various input signals and interconnect structures in digital circuits.

  • A Study on an Antenna Selection Scheme for Space-Time Turbo Code for OFDM Systems

    Masayuki HOSHINO  Mitsuru UESUGI  Takeo OHGANE  Yasutaka OGAWA  Toshihiko NISHIMURA  

     
    PAPER

      Vol:
    E86-B No:12
      Page(s):
    3476-3482

    Space-Time Turbo code is an effective method for the enhancement of link capacity and maximizing the link-budget by balancing the coding gain obtained via Turbo codes and the diversity gain obtained through multiple antenna transmission. A study on an antenna selection scheme for Space-Time Turbo code for OFDM systems is presented in this paper. In the proposed method, the systematic bits and the punctured parity bits are sent from the selected antenna for each sub-carrier, while data transmission is suspended from the antenna experiencing poor channel conditions at the receiver. Simulation results show that the proposed method yields a 2.2 dB gain in the required TxEb/N0 relative to the conventional method, and makes the channel estimation accuracy more robust. Moreover, the proposed method reduces transmission power by about 4 dB compared to the conventional method.

  • Active Learning with Model Selection -- Simultaneous Optimization of Sample Points and Models for Trigonometric Polynomial Models

    Masashi SUGIYAMA  Hidemitsu OGAWA  

     
    PAPER-Pattern Recognition

      Vol:
    E86-D No:12
      Page(s):
    2753-2763

    In supervised learning, the selection of sample points and models is crucial for acquiring a higher level of the generalization capability. So far, the problems of active learning and model selection have been independently studied. If sample points and models are simultaneously optimized, then a higher level of the generalization capability is expected. We call this problem active learning with model selection. However, active learning with model selection can not be generally solved by simply combining existing active learning and model selection techniques because of the active learning/model selection dilemma: the model should be fixed for selecting sample points and conversely the sample points should be fixed for selecting models. In this paper, we show that the dilemma can be dissolved if there is a set of sample points that is optimal for all models in consideration. Based on this idea, we give a practical procedure for active learning with model selection in trigonometric polynomial models. The effectiveness of the proposed procedure is demonstrated through computer simulations.

  • A C-Ku Band 5-Bit MMIC Phase Shifter Using Optimized Reflective Series/Parallel LC Circuits

    Kenichi MIYAGUCHI  Morishige HIEDA  Yukinobu TARUI  Mikio HATAMOTO  Koh KANAYA  Yoshitada IYAMA  Tadashi TAKAGI  Osami ISHIDA  

     
    PAPER-Active(Phase Shifter)

      Vol:
    E86-C No:12
      Page(s):
    2429-2436

    A C-Ku band 5-bit MMIC phase shifter using optimized reflective series/parallel LC circuits is presented. The proposed circuit has frequency independent characteristics in the case of 180 phase shift, ideally. Also, an ultra-broad-band circuit design theory for the 180 optimized reflective circuit has derived, which gives optimum characteristics compromising between loss and phase shift error. The fabricated 5-bit MMIC phase shifter with SPDT switch has successfully demonstrated a typical insertion loss of 9.4 dB 1.4 dB, and a maximum RMS phase shift error of 7 over the 6 to 18 GHz band. The measured results validate the proposed design theory of the phase shifter.

  • Measurement of Early Reflections in a Room with Five Microphone System

    Chulmin CHOI  Lae-Hoon KIM  Yangki OH  Sejin DOO  Koeng-Mo SUNG  

     
    LETTER-Engineering Acoustics

      Vol:
    E86-A No:12
      Page(s):
    3283-3287

    The measurement of the 3-dimensional behavior of early reflections in a sound field has been an important issue in auditorium acoustics since the reflection profile has been found to be strongly correlated with the subjective responsiveness of a listener. In order to detect the incidence angle and relative amplitude of reflections, a 4-point microphone system has conventionally been used. A new measurement system is proposed in this paper, which has 5 microphones. Microphones are located on each four apex of a tetrahedron and at the center of gravity. Early reflections, including simultaneously incident reflections,which previous 4-point microphone system could not discriminate as individual wavefronts, were successfully found with the new system. In order to calculate accurate image source positions, it is necessary to determine the exact peak positions from measured impulse responses composed of highly deformed and overlapped impulse trains. For this purpose, a peak-detecting algorithm, which finds dominant peaks in the impulse response by an iteration method, is introduced. In this paper, the theoretical background and features of the 5-microphone system are described. Also, some results of experiments using this system are described.

  • A Hardware/Software Partitioning Algorithm for Processor Cores with Packed SIMD-Type Instructions

    Nozomu TOGAWA  Koichi TACHIKAKE  Yuichiro MIYAOKA  Masao YANAGISAWA  Tatsuo OHTSUKI  

     
    LETTER-Design Methodology

      Vol:
    E86-A No:12
      Page(s):
    3218-3224

    This letter proposes a new hardware/software partitioning algorithm for processor cores with SIMD instructions. Given a compiled assembly code including SIMD instructions and a timing constraint, the proposed algorithm synthesizes an area-optimized processor core with a new assembly code. Firstly, we assume for each operation type a super SIMD functional unit which can execute all the SIMD instructions. Secondly we reduce a SIMD instruction or "sub-function" of each super functional unit, one by one, while the timing constraint is satisfied. At the same time, we update the assembly code so that it can run on the new processor configuration. By repeating this process, we finally find SIMD functional unit configuration as well as a processor core architecture. The promising experimental results are also shown.

  • Implementation of Java Accelerator for High-Performance Embedded Systems

    Motoki KIMURA  Morgan Hirosuke MIKI  Takao ONOYE  Isao SHIRAKAWA  

     
    PAPER-Simulation Accelerator

      Vol:
    E86-A No:12
      Page(s):
    3079-3088

    A Java execution environment is implemented, in which a hardware engine is operated in parallel with an embedded processor. This pair of hardware facilities together with an additional software kernel are devised for existing embedded systems, so as to execute Java applications more efficiently in such a way that 39 instructions are added to the original Java Virtual Machine to implement the software kernel. The exploration of design parameters is also attempted to attain a low hardware cost and high performance. The proposed hardware engine of a 6-stage pipeline can be integrated in a single chip using 30 k gates together with the instruction and data cache memories. The proposed approach improves the execution speed by a factor of 5 in comparison with the J2ME software implementation.

  • Upper Bounds for Quantization Errors in Digital Subtraction Angiography

    Ali REZA  

     
    PAPER-Medical Engineering

      Vol:
    E86-D No:11
      Page(s):
    2463-2471

    Digital Subtraction Angiography (DSA) is a technique used for enhancement of small details in angiogram imaging systems. In this approach, X-ray images of a subject, after injection, are subtracted from a reference X-ray image, taken from the same subject before injection. Due to the exponential absorption property of X-rays, effects of small details at different depth appear differently on X-ray images. Consequently, image subtraction cannot be employed on the original images without any adjustment or modification. Proper modification, in this case, is to use some form of logarithmic operation on images before subtraction. In medical imaging systems, the system designer has a choice to implement this logarithmic operation in the analog domain, before digitization of the video signal, or in the digital domain after analog-to-digital conversion (ADC) of the original video signal. In this paper, the difference between these two approaches is studied and upper bounds for quantization error in both cases are calculated. Based on this study, the best approach for utilization of the logarithmic function is proposed. The overall effects of these two approaches on the inherent signal noise are also addressed.

  • Efficiently Accommodation of IP Traffic by Employing WDM-Channel-Count Asymmetric Bi-directional Optical Amplifiers

    Masatoyo SUMIDA  Tsutomu KUBO  Takamasa IMAI  

     
    PAPER-Fiber-Optic Transmission

      Vol:
    E86-B No:11
      Page(s):
    3174-3181

    A bi-directional WDM transmission link that changes the channel-count assigned in each direction is proposed for efficiently accommodating IP traffic which is characterized by directional volume asymmetry. A novel bi-directional optical amplifier is also proposed for overcoming the problems that arise in realizing the proposed link. The asymmetric, bi-directional, repeatered WDM transmission of 8 (total) 10 Gbit/s, 50 GHz-spaced channels over eleven 50 km spans is successfully demonstrated. The experimental results clarify that, owing to the use of the proposed bi-directional amplifier, directional asymmetry in channel-count and Rayleigh backscattering do not result in any significant performance degradation. Based upon an analysis of backscattering induced impairment, we show that the total transmission loss of 1000 dB can be supported if the span loss is 20 dB.

  • Joint Antenna Diversity and Frequency-Domain Equalization for Multi-Rate MC-CDMA

    Fumiyuki ADACHI  Tomoki SAO  

     
    PAPER-Terrestrial Radio Communications

      Vol:
    E86-B No:11
      Page(s):
    3217-3224

    For the reception of MC-CDMA signals in a frequency-selective fading channel, frequency-domain equalization is necessary before despreading. In this paper, joint antenna diversity combining and one-tap frequency-domain equalization is considered (simply referred to as the joint antenna diversity & equalization, in this paper). A receiver structure for joint antenna diversity & equalization is presented and the unified weights based on minimum mean square error (MMSE) criterion are found in the presence of multi-users with different spreading factors and transmit powers. For comparison, antenna diversity combining after despreading using MMSE combining (MMSEC) is also considered. The achievable bit error rate (BER) performances with joint antenna diversity & equalization and with antenna diversity after MMSEC despreading in a frequency-selective Rayleigh fading channel are evaluated by computer simulations and compared.

  • On Received Signal Power Distribution of Wideband Signals in a Frequency-Selective Rayleigh Fading Channel

    Fumiyuki ADACHI  Akihito KATO  

     
    LETTER-Wireless Communication Technology

      Vol:
    E86-B No:11
      Page(s):
    3340-3343

    A mathematical expression for the received signal power in a severe frequency-selective fading channel is derived. Using the derived expression, the signal power distributions are obtained by Monte-Carlo simulation and compared with the Nakagami m-power distribution. It is found that the power distribution matches well with the Nakagami m-power distribution when the multipath channel has a uniform power delay profile.

  • Electromagnetic Scattering Analysis for Crack Depth Estimation

    Hidenori SEKIGUCHI  Hiroshi SHIRAI  

     
    PAPER

      Vol:
    E86-C No:11
      Page(s):
    2224-2229

    A simple non-destructive depth estimation method for a crack on a metal surface has been proposed. This method is based on our finding that the electromagnetic back scattering from a narrow trough (crack model) on the ground plane causes periodical nulls (dips) as the frequency changes, and the first dip occurs when the depth of the crack becomes nearly one half of the incident wavelength. Dependencies of the crack's aperture and the incident angle have also been studied from rigorous and numerical analyses, and considered as our depth estimation parameters. A simple estimation formula for a crack depth has been derived from these studies. Test measurement has been made to check the accuracy of our estimation formula. Time domain gating process is utilized for isolating the crack scattering spectra buried in the measured frequency RCS data. Tested crack types are a narrow rectangular, a tapered, and a stair approximated crack shapes. It is found that the depth of these cracks can be measured within 3 percent error by our estimation method.

5721-5740hit(8214hit)