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13961-13980hit(21534hit)

  • Ultralow-Voltage MTCMOS/SOI Circuits for Batteryless Mobile System

    Takakuni DOUSEKI  Masashi YONEMARU  Eiji IKUTA  Akira MATSUZAWA  Atsushi KAMEYAMA  Shunsuke BABA  Tohru MOGAMI  Hakaru KYURAGI  

     
    INVITED PAPER

      Vol:
    E87-C No:4
      Page(s):
    437-447

    This paper describes an ultralow-power multi-threshold (MT) CMOS/SOI circuit technique that mainly uses fully-depleted MOSFETs. The MTCMOS/SOI circuit, which combines fully-depleted low- and medium-Vth CMOS/SOI logic gates and high-Vth power-switch transistors, makes it possible to lower the supply voltage to 0.5 V and reduce the power dissipation of LSIs to the 1-mW level. We overview some MTCMOS/SOI digital and analog components, such as a CPU, memory, analog/RF circuit and DC-DC converter for an ultralow-power mobile system. The validity of the ultralow-voltage MTCMOS/SOI circuits is confirmed by the demonstration of a self-powered 300-MHz-band short-range wireless system. A 1-V SAW oscillator and a switched-capacitor-type DC-DC converter in the transmitter makes possible self-powered transmission by the heat from a hand. In the receiver, a 0.5-V digital controller composed of a 8-bit CPU, 256-kbit SRAM, and ROM also make self-powered operation under illumination possible.

  • Integrated Development Environment for Knowledge-Based Systems and Its Practical Application

    Keiichi KATAMINE  Masanobu UMEDA  Isao NAGASAWA  Masaaki HASHIMOTO  

     
    PAPER-Knowledge Engineering and Robotics

      Vol:
    E87-D No:4
      Page(s):
    877-885

    The modeling of an application domain and its specific knowledge description language are important for developing knowledge-based systems. A rapid-prototyping approach is suitable for such developments since in this approach the modeling and language development are processed simultaneously. However, programming languages and their supporting environments which are usually used for prototyping are not necessarily adequate for developing practical applications. We have been developing an integrated development environment for knowledge-based systems, which supports all the development phases from the early prototyping phase to final commercial development phase. The environment called INSIDE is based on a Prolog abstract machine, and provides all of the functions required for the development of practical applications in addition to the standard Prolog features. This enables the development of both prototypes and practical applications in the same environment. Moreover, their efficient development and maintenance can be achieved. In addition, the effectiveness of INSIDE is described by examples of its practical application.

  • VLSI-Oriented Motion Estimation Using a Steepest Descent Method in Mobile Video Coding

    Masayuki MIYAMA  Junichi MIYAKOSHI  Kousuke IMAMURA  Hideo HASHIMOTO  Masahiko YOSHIMOTO  

     
    PAPER

      Vol:
    E87-C No:4
      Page(s):
    466-474

    This paper describes a VLSI-oriented motion estimation algorithm using a steepest descent method (SDM) applied to MPEG-4 visual communication with a mobile terminal. The SDM algorithm is optimized for QCIF or CIF resolution video and VLSI implementation. The SDM combined with a subblock search method is developed to enhance picture quality. Simulation results show that a mean PSNR drop of the SDM algorithm processing QCIF 15 fps resolution video in comparison with a full search algorithm is -0.17 dB. Power consumption of a VLSI based on the SDM algorithm assuming 0.18 µm CMOS technology is estimated at 2 mW. The VLSI attains higher picture quality than that based on the other fast motion estimation algorithm, and is applicable to mobile video applications.

  • Digital Steganography Utilizing Features of JPEG Images

    Motoi IWATA  Kyosuke MIYAKE  Akira SHIOZAKI  

     
    PAPER-Image

      Vol:
    E87-A No:4
      Page(s):
    929-936

    This paper proposes a new steganographic method utilizing features of JPEG compression. The method embeds secret information using the number of zeroes in a block of quantized DCT coefficients in minimum coding units (MCU) of JPEG images. In the method, we can embed secret information into JPEG images with degradation like that by JPEG compression. Furthermore, the method causes little change of the histogram of quantized DCT coefficients, so it is hard to perceive secret information embedded by the method. The method mainly modifies boundaries between zero and non-zero DCT coefficients, so we can use the low frequency side of DCT coefficients for another steganographic method.

  • Efficient Edge Function Based Anisotropic Texture Filtering

    Hyun-Chul SHIN  Jin-Aeon LEE  Lee-Sup KIM  

     
    LETTER-Computer Graphics

      Vol:
    E87-A No:4
      Page(s):
    964-970

    In texture mapping, anisotropic filtering methods, which require more texels, have been proposed for high-quality images. Memory bandwidth, however, is still limited by a bottleneck in the texture-filtering hardware. In this paper, we propose anisotropic texture filtering based on edge function. In generating the weight that plays a key role in filtering texels loaded from memory, the edge function gives accurate contribution of texels to the pixel intensity. The quality of images is superior to other methods. For images of the same quality, our method requires less than half the texels of other methods. In other words, the improvement in performance is more than twice that of other methods.

  • Estimation of Degradation of Nickel-Cadmium Batteries for Cordless Telephones by a Discharge-Current-Pulse Technique

    Toshiro HIRAI  

     
    PAPER-Energy in Electronics Communications

      Vol:
    E87-B No:4
      Page(s):
    984-989

    We investigated the accuracy of nickel-cadmium (Ni/Cd) battery degradation estimation by measuring the capacity of over 400 used cordless-telephone batteries using a discharge-current-pulse technique. The capacity is calculated from the change in battery voltage after the current pulse is applied, using an equation that we developed. Battery degradation is represented by a percentage of the capacity based on the nominal one. To estimate the accuracy of the degradation estimation, we compare capacity Qe estimated from the current pulse with the capacity Qa measured by discharging the batteries. The Qe estimated from the current pulse was within a range of 20% of error indicated by (Qe-Qa) for 47% of the tested batteries. The Qe of 51% of the batteries, however, was underestimated and exceeded lower limit (-20%) of the error. One reason for the discrepancy could be that the equation is inadequate for estimating the capacity from the current pulse. On the other hand, the capacity Qe of 1% of the batteries was overestimated and exceeded upper limit (+20%) of the error. An internal short is probably the main reason for this.

  • Circuit Partition and Reordering Technique for Low Power IP Design

    Kun-Lin TSAI  Shanq-Jang RUAN  Chun-Ming HUANG  Edwin NAROSKA  Feipei LAI  

     
    PAPER

      Vol:
    E87-C No:4
      Page(s):
    613-620

    Circuit partition, retiming and state reordering techniques are effective in reducing power consumption of circuits. In this paper, we propose a partition architecture and a methodology to reduce power consumption when designing low power IP, named PRC (Partition and Reordering Circuit). The circuit reordering synthesis flow consists of three phases: first, evenly partition the circuit based on the Shannon expansion; secondly encode the output vectors of each partition to build an equivalent functional logic. Finally, apply reordering algorithm to reorganize the logic function to reduce power consumption and decrease area cost. The validity of our architecture is proven by applying it to MCNC benchmark with simulation environment.

  • Orthogonal Transformation to Enhance the Security of the Still Image Watermarking System

    Guo-rui FENG  Ling-ge JIANG  Chen HE  

     
    LETTER-Digital Signal Processing

      Vol:
    E87-A No:4
      Page(s):
    949-951

    A watermarking system is secure as long as it satisfies Kerckhoffs principle according to the cryptography. In this letter, two novel techniques named the encrypted orthogonal transformation and its improved scheme as useful preprocessing methods are presented to apply to the watermarking field, which can enhance the security of the watermarking scheme. Compared to discrete cosine transform watermarking algorithms, this method has similar robustness but higher security.

  • A Rate-Controlled Regulation-Scheduling Scheme for Multimedia Traffic Management

    I-Chieh LIN  Hsiang-Ren SHIH  Chun-Liang HOU  Shie-Jue LEE  

     
    PAPER-Fundamental Theories

      Vol:
    E87-B No:4
      Page(s):
    797-806

    A major challenge in the design of multimedia networks is to meet the quality of service (QoS) requirements of all admitted users. Regulation and scheduling are key factors for fulfilling such requirements. We propose a rate-based regulation-scheduling scheme in which the regulation function is modulated by both the tagged stream's characteristics and the state information fed-back from the scheduler. The rate-jitter and bandwidth share of each tagged connection are controlled appropriately by considering the system time and the queue length of the scheduler. Simulation results have shown that the proposed scheme works better than other rate-based disciplines.

  • An Improved One-Pointer Traceback Method

    Shang-Chih MA  

     
    LETTER-Communication Devices/Circuits

      Vol:
    E87-B No:4
      Page(s):
    1016-1018

    Traceback schemes used in Viterbi decoders can be categorized into multi-pointer and one-pointer methods. A traceback scheme using one-pointer method has been shown to be better than the one using multi-pointer method in terms of memory size and latency. We propose an area efficient traceback method which is based on the one-pointer scheme. The proposed method can be implemented by using only two single-port memory banks. In comparison with traditional methods, lower power consumption and smaller area occupation are required for the proposed method.

  • Unsupervised Polarimetric SAR Image Classification

    Junyi XU  Jian YANG  Yingning PENG  Chao WANG  

     
    LETTER-Sensing

      Vol:
    E87-B No:4
      Page(s):
    1048-1052

    In this letter, the concept of cross-entropy is introduced for unsupervised polarimetric synthetic aperture radar (SAR) image classification. The difference between two scatterers is decomposed into three parts, i.e., the difference of average scattering characteristic, the difference of scattering randomness and the difference of scattering matrix span. All these three parts are expressed in cross-entropy formats. The minimum cross-entropy principle is adopted to make classification decision. It works well in unsupervised terrain classification with a NASA/JPL AIRSAR image.

  • Multiresolution Watermarking for MPEG-4 2D Mesh Animation

    Shih-Hsuan YANG  Chun-Yen LIAO  Chin-Yun HSIEH  

     
    PAPER-Information Security

      Vol:
    E87-A No:4
      Page(s):
    879-886

    Although watermarking techniques have been extensively developed for natural videos, little progress is made in the area of graphics animation. Following the former successful MPEG-1 and MPEG-2 coding standards that provide efficient representations of natural videos, the emerging MPEG-4 standard incorporates new coding tools for 2D mesh animation. Graphics animation information is crucial for many applications and may need proper protection. In this paper, we develop a watermarking technique suitable for MPEG-4 2D mesh animation. The proposed method is based on the multiresolution analysis of 2D dynamic mesh. We perform wavelet transform on the temporal sequence of the node points to extract the significant spectral components of mesh movement, which we term the "feature motions. " A binary watermark invisibly resides in the feature motions based on the spread-spectrum principle. Before watermark detection, a spatial-domain least-squares registration technique is used to restore the possibly geometrically distorted mesh data. Each watermark bit is then detected by hard decision with cryptographically secure keys. We have tested the proposed method with a variety of attacks, including affine transformations, temporal smoothing, spectral enhancement and attenuation, additive random noise, and a combination of the above. Experimental results show that the proposed watermarks can withstand the aforementioned attacks.

  • Inter-Symbol Interference Suppression Scheme Using Even-Numbered Sub-Carriers for Fixed-Rate OFDM Systems

    Fumiaki MAEHARA  Fumihito SASAMORI  Fumio TAKAHATA  

     
    PAPER-Wireless Communication Technology

      Vol:
    E87-B No:4
      Page(s):
    866-872

    This paper proposes an inter-symbol interference (ISI) suppression scheme using only the even-numbered sub-carriers for the fixed-rate OFDM systems with the 2-dimensional modulation. The proposed scheme is based on the principle that the first half of the waveform in the time domain is the same as the second half when an OFDM symbol is composed of only the even-numbered sub-carriers. The feature of the proposed scheme is that, in the case of the maximum multipath delay beyond the duration of the guard interval, the OFDM symbol with only the even-numbered sub-carriers is transmitted in order to generate the extended virtual guard interval and that the high-level modulation with the sub-carrier power enhancement is applied to achieve the constant data rate. In addition, at the receiver, only the second half of the OFDM symbol is used for the FFT processing to avoid the ISI. Moreover, the condition of the maximum multipath delay is notified to the transmitter by using the feedback channel. Numerical results given by computer simulation showed that the proposed scheme provides far better bit error rate (BER) performance than the traditional OFDM transmission using all sub-carriers under the multipath delay beyond the duration of the guard interval.

  • Evaluation of Performance Prediction Method for Master/Slave Parallel Programs

    Yasuharu MIZUTANI  Fumihiko INO  Kenichi HAGIHARA  

     
    PAPER-Computer Systems

      Vol:
    E87-D No:4
      Page(s):
    967-975

    This paper describes the design and implementation of a testbed for predicting master/slave (M/S) programs written using Message Passing Interface (MPI) programs. The testbed, named M/S Emulator (MSE), aims at assisting developers in evaluating the performance of M/S programs and dynamic load-balancing strategies on clusters of PCs. In order to realize this, MSE predicts the communication time by using a realistic parallel computational model, an extension of the LogGPS model. This extended model improves the prediction accuracy on a large number of processors, because it captures the master's bottleneck: the overhead required for retrieving arrival messages from the slaves. Current MSE also employs a best effort emulation method for predicting the calculation time. In our experiments, MSE demonstrated an accurate prediction on clusters, especially on a larger number of nodes. Therefore, we believe that our extended model enables us to analyze the scalability of the M/S program performance.

  • Performance Evaluation of K Shortest Path Algorithms in MPLS Traffic Engineering

    Guangyi LIU  Yang YANG  Xiaokang LIN  

     
    LETTER-Fundamental Theories

      Vol:
    E87-B No:4
      Page(s):
    1007-1011

    A number of on-line and off-line algorithms for load balancing on multiple paths for MPLS (MultiProtocol Label Switching) traffic engineering have now been proposed, in which it is always assumed that sets of LSPs (Label Switched Path) have already been established between node pairs. While how to choose these paths is an important issue in traffic engineering, it has not been well studied yet. In this paper, we attempt to fill in this gap. As the shortest paths are always preferred in routing problems, we evaluate several k shortest path algorithms from the viewpoint of bandwidth use efficiency and the number of the found paths. Extensive simulations have been performed in different kinds of topologies to factor out effects of network characteristics on these algorithms' path calculation performances. It is found out that the performances of the evaluated algorithms are limited in some cases and the design of new algorithms for the path calculation problem is worth studying in the future.

  • A Wide Range 1.0-3.6 V 200 Mbps, Push-Pull Output Buffer Using Parasitic Bipolar Transistors

    Takahiro SHIMADA  Hiromi NOTANI  Yasunobu NAKASE  Hiroshi MAKINO  Shuhei IWADE  

     
    PAPER

      Vol:
    E87-C No:4
      Page(s):
    571-577

    We proposed a push-pull output buffer that maintains the data transmission rate for lower supply voltages. It operates at an internal supply voltage (VDD) of 0.7-1.6 V and an interface supply voltage (VDDX) of 1.0-3.6 V. In low VDDX operation, the output buffer utilizes parasitic bipolar transistors instead of MOS transistors to maintain drivability. Furthermore forward body bias (FBB) control is provided for the level converter in low VDD operation. We fabricated a test chip with a standard 0.15 µm CMOS process. Measurement results indicate that the proposed output buffer achieves 200 Mbps operation at VDD of 0.7 V and VDDX of 1.0 V.

  • Intelligent versus Random Software Testing

    Juichi TAKAHASHI  

     
    PAPER-Metrics, Test, and Maintenance

      Vol:
    E87-D No:4
      Page(s):
    849-854

    Comparison of intelligent and random testing in data inputting is still under discussion. Little is also known about testing for the whole software and empirical testing methodology when random testing used. This study research not only for data inputting testing, but also operation of software (called transitions) in order to test the whole GUI software by intelligent and random testing. Methodology of this study is that we attempt to research efficiency of random and intelligent testing by Chinese postman problem. In general, random testing is considered straightforward but not efficient. Chinese postman problem testing is complicated but efficient. The comparison between random and intelligent testing would give further recommendation for software testing methodology.

  • +3 V/-3 V Operation 1.2 Gbps Write Driver for Hard Disk Drives

    Yasuyuki OKUMA  Kenji MAIO  Hiroyasu YOSHIZAWA  

     
    PAPER

      Vol:
    E87-C No:4
      Page(s):
    578-581

    This paper describes low voltage write driver with pulse adding circuit. The presented write driver is constructed from the main switch circuit with impedance matching and pulse adding circuits and a timing generator. The main switch circuit is voltage type driver with matching resisters for flexible lines between a write driver and a write head. For 1.2 Gbps operation, the flexible lines have to be treated as transmission lines. Furthermore, to achieve steep rise/fall edge, the pulse adding circuits to generate double of supply voltage, +3.3/-3 V, at rise/fall edge have been developed. The write driver was implemented using 0.35 µm BiCMOS process. The die size is 1.2 mm0.6 mm and the measured results achieved tr/tf of less than 0.25 ns, tp of 0.5 ns and Ip of 73 mA.

  • Experimental Study of Non-specular Wave Scattering from Building Surface Roughness for the Mobile Propagation Modeling

    Hary BUDIARTO  Kenshi HORIHATA  Katsuyuki HANEDA  Jun-ichi TAKADA  

     
    PAPER-Antenna and Propagation

      Vol:
    E87-B No:4
      Page(s):
    958-966

    In the urban area, buildings are the main scatterer which dominate the mobile propagation characteristics. However, reflection, diffraction, and scattering on the building surfaces in the radio environment induce undesirable multipath propagation. Multipath prediction with respect to a building surface has been conventionally based on an assumption that reflection from the surface has a substantial specular direction. However non-specular scattering from the building surface can affect the channel characteristics as well as specular scattering. This paper presents multipath characteristics of non-specular wave scattering from building surface roughness based on the experimental results. Superresolution method was applied as an approach to handle the signal parameters (DoA, ToA) of the individual incoming waves reflected from building surface roughness. The results show that the multipaths can be detected at many scatterers, such as ground, window's glass, window's frames and bricks surface, as well as directly from the transmitter. Most of the scattered waves are arriving closely from specular directions. The measured reflection coefficients were well bounded by reflection coefficients of the theoretically smooth and random rough surface. The Fresnel reflection coefficient formula, considering the finite thickness of the building surface and Gaussian scattering correction, give better prediction for glass and bricks reflection coefficient measurement.

  • Safety Verification of Material Handling Systems Driven by Programmable Logic Controller--Consideration of Physical Behavior of Plants--

    Eiji KONAKA  Tatsuya SUZUKI  Shigeru OKUMA  

     
    PAPER

      Vol:
    E87-A No:4
      Page(s):
    843-849

    The PLC (Programmable Logic Controller) has been widely used in the industrial world as a controller for manufacturing systems, as a process controller and so on. The conventional PLC has been designed and verified as a pure Discrete Event System (DES) by using an abstract model of a controlled plant. In verifying the PLC, however, it is also important to take into account the physical behavior (e.g. dynamics, shape of objects) of the controlled plant in order to guarantee such important factors as safety. This paper presents a new verification technique for the PLC-based control system, which takes into account these physical behaviors, based on a Hybrid Dynamical System (HDS) framework. The other key idea described in the paper is the introduction of the concept of signed distance which not only measures the distance between two objects but also checks whether two objects interfere with each other. The developed idea is applied to illustrative material handling problems, and its usefulness is demonstrated.

13961-13980hit(21534hit)