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9881-9900hit(20498hit)

  • Recalling Temporal Sequences of Patterns Using Neurons with Hysteretic Property

    Johan SVEHOLM  Yoshihiro HAYAKAWA  Koji NAKAJIMA  

     
    PAPER

      Vol:
    E91-A No:4
      Page(s):
    943-950

    Further development of a network based on the Inverse Function Delayed (ID) model which can recall temporal sequences of patterns, is proposed. Additional advantage is taken of the negative resistance region of the ID model and its hysteretic properties by widening the negative resistance region and letting the output of the ID neuron be almost instant. Calling this neuron limit ID neuron, a model with limit ID neurons connected pairwise with conventional neurons enlarges the storage capacity and increases it even further by using a weightmatrix that is calculated to guarantee the storage after transforming the sequence of patterns into a linear separation problem. The network's tolerance, or the model's ability to recall a sequence, starting in a pattern with initial distortion is also investigated and by choosing a suitable value for the output delay of the conventional neuron, the distortion is gradually reduced and finally vanishes.

  • Motion Belts: Visualization of Human Motion Data on a Timeline

    Hiroshi YASUDA  Ryota KAIHARA  Suguru SAITO  Masayuki NAKAJIMA  

     
    PAPER-Computer Graphics

      Vol:
    E91-D No:4
      Page(s):
    1159-1167

    Because motion capture system enabled us to capture a number of human motions, the demand for a method to easily browse the captured motion database has been increasing. In this paper, we propose a method to generate simple visual outlines of motion clips, for the purpose of efficient motion data browsing. Our method unfolds a motion clip into a 2D stripe of keyframes along a timeline that is based on semantic keyframe extraction and the best view point selection for each keyframes. With our visualization, timing and order of actions in the motions are clearly visible and the contents of multiple motions are easily comparable. In addition, because our method is applicable for a wide variety of motions, it can generate outlines for a large amount of motions fully automatically.

  • The Container Problem in Bubble-Sort Graphs

    Yasuto SUZUKI  Keiichi KANEKO  

     
    PAPER-Algorithm Theory

      Vol:
    E91-D No:4
      Page(s):
    1003-1009

    Bubble-sort graphs are variants of Cayley graphs. A bubble-sort graph is suitable as a topology for massively parallel systems because of its simple and regular structure. Therefore, in this study, we focus on n-bubble-sort graphs and propose an algorithm to obtain n-1 disjoint paths between two arbitrary nodes in time bounded by a polynomial in n, the degree of the graph plus one. We estimate the time complexity of the algorithm and the sum of the path lengths after proving the correctness of the algorithm. In addition, we report the results of computer experiments evaluating the average performance of the algorithm.

  • Low Power LDPC Code Decoder Architecture Based on Intermediate Message Compression Technique

    Kazunori SHIMIZU  Nozomu TOGAWA  Takeshi IKENAGA  Satoshi GOTO  

     
    PAPER

      Vol:
    E91-A No:4
      Page(s):
    1054-1061

    Reducing the power dissipation for LDPC code decoder is a major challenging task to apply it to the practical digital communication systems. In this paper, we propose a low power LDPC code decoder architecture based on an intermediate message-compression technique which features as follows: (i) An intermediate message compression technique enables the decoder to reduce the required memory capacity and write power dissipation. (ii) A clock gated shift register based intermediate message memory architecture enables the decoder to decompress the compressed messages in a single clock cycle while reducing the read power dissipation. The combination of the above two techniques enables the decoder to reduce the power dissipation while keeping the decoding throughput. The simulation results show that the proposed architecture improves the power efficiency up to 52% and 18% compared to that of the decoder based on the overlapped schedule and the rapid convergence schedule without the proposed techniques respectively.

  • Prevention in a Chip of EMI Noise Caused by X'tal Oscillator

    Atsushi KUROKAWA  Hiroshi FUJITA  Tetsuya IBE  

     
    PAPER

      Vol:
    E91-A No:4
      Page(s):
    1077-1083

    Developing LSIs with EMI suppression, particularly for use in automobiles, is important for improving warranties and customer acquisition. First, we describe that the measures against EMI noise caused by a X'tal oscillator are important. Next, we present a practical method for analyzing the noise with models of the inside and outside of a chip. In addition, we propose a within-chip measure against EMI noise that takes chip cost into account. The noise is suppressed by using an appropriate resistance and capacitance on the power line. Simulation results demonstrated the method's effectiveness in suppressing noise.

  • A Palmprint Recognition Algorithm Using Phase-Only Correlation

    Koichi ITO  Takafumi AOKI  Hiroshi NAKAJIMA  Koji KOBAYASHI  Tatsuo HIGUCHI  

     
    PAPER

      Vol:
    E91-A No:4
      Page(s):
    1023-1030

    This paper presents a palmprint recognition algorithm using Phase-Only Correlation (POC). The use of phase components in 2D (two-dimensional) discrete Fourier transforms of palmprint images makes it possible to achieve highly robust image registration and matching. In the proposed algorithm, POC is used to align scaling, rotation and translation between two palmprint images, and evaluate similarity between them. Experimental evaluation using a palmprint image database clearly demonstrates efficient matching performance of the proposed algorithm.

  • A High-Speed Two-Parallel Radix-24 FFT/IFFT Processor for MB-OFDM UWB Systems

    Jeesung LEE  Hanho LEE  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E91-A No:4
      Page(s):
    1206-1211

    This paper presents a novel high-speed, low-complexity two-parallel 128-point radix-24 FFT/IFFT processor for MB-OFDM ultrawideband (UWB) systems. The proposed high-speed, low-complexity FFT architecture can provide a higher throughput rate and low hardware complexity by using a two-parallel data-path scheme and a single-path delay-feedback (SDF) structure. The radix-24 FFT algorithm is also realized in our processor to reduce the number of complex multiplications. The proposed FFT/IFFT processor has been designed and implemented with 0.18-µm CMOS technology in a supply voltage of 1.8 V. The proposed two-parallel FFT/IFFT processor has a throughput rate of up to 900 Msample/s at 450 MHz while requiring much smaller hardware complexity and low power consumption.

  • Redundant Vias Insertion for Performance Enhancement in 3D ICs

    Xu ZHANG  Xiaohong JIANG  Susumu HORIGUCHI  

     
    PAPER

      Vol:
    E91-C No:4
      Page(s):
    571-580

    Three dimensional (3D) integrated circuits (ICs) have the potential to significantly enhance VLSI chip performance, functionality and device packing density. Interconnects delay and signal integrity issues are critical in chip design. In this paper, we extend the idea of redundant via insertion of conventional 2D ICs and propose an approach for vias insertion/placement in 3D ICs to minimize the propagation delay of interconnects with the consideration of signal integrity. The simulation results based on a 65 nm CMOS technology demonstrate that our approach in general can result in a 9% improvement in average delay and a 26% decrease in reflection coefficient. It is also shown that the proposed approach can be more effective for interconnects delay improvement when it is integrated with the buffer insertion in 3D ICs.

  • Construction of Appearance Manifold with Embedded View-Dependent Covariance Matrix for 3D Object Recognition

    Lina  Tomokazu TAKAHASHI  Ichiro IDE  Hiroshi MURASE  

     
    PAPER-Pattern Recognition

      Vol:
    E91-D No:4
      Page(s):
    1091-1100

    We propose the construction of an appearance manifold with embedded view-dependent covariance matrix to recognize 3D objects which are influenced by geometric distortions and quality degradation effects. The appearance manifold is used to capture the pose variability, while the covariance matrix is used to learn the distribution of samples for gaining noise-invariance. However, since the appearance of an object in the captured image is different for every different pose, the covariance matrix value is also different for every pose position. Therefore, it is important to embed view-dependent covariance matrices in the manifold of an object. We propose two models of constructing an appearance manifold with view-dependent covariance matrix, called the View-dependent Covariance matrix by training-Point Interpolation (VCPI) and View-dependent Covariance matrix by Eigenvector Interpolation (VCEI) methods. Here, the embedded view-dependent covariance matrix of the VCPI method is obtained by interpolating every training-points from one pose to other training-points in a consecutive pose. Meanwhile, in the VCEI method, the embedded view-dependent covariance matrix is obtained by interpolating only the eigenvectors and eigenvalues without considering the correspondences of each training image. As it embeds the covariance matrix in manifold, our view-dependent covariance matrix methods are robust to any pose changes and are also noise invariant. Our main goal is to construct a robust and efficient manifold with embedded view-dependent covariance matrix for recognizing objects from images which are influenced with various degradation effects.

  • Highly Reliable Multiple-Valued Current-Mode Comparator Based on Active-Load Dual-Rail Operation

    Masatomo MIURA  Takahiro HANYU  

     
    PAPER

      Vol:
    E91-C No:4
      Page(s):
    589-594

    In this paper, a multiple-valued current-mode (MVCM) circuit based on active-load dual-rail differential logic is proposed for a high-performance arithmetic VLSI system with crosstalk-noise immunity. The use of dual-rail complementary differential-pair circuits (DPCs), whose outputs are summed up by wiring makes it possible to reduce the common-mode noise, and yet enhance the switching speed. By using the diode-connected cross-coupled PMOS active loads, the rapid transition of switching in the DPC is relaxed appropriately, which can also eliminate spiked input noise. It is demonstrated that the noise reduction ratio and the switching delay of the proposed MVCM circuit in a 90 nm CMOS technology is superior to those of the corresponding ordinary implementation.

  • An Unsupervised Opinion Mining Approach for Japanese Weblog Reputation Information Using an Improved SO-PMI Algorithm

    Guangwei WANG  Kenji ARAKI  

     
    PAPER-Data Mining

      Vol:
    E91-D No:4
      Page(s):
    1032-1041

    In this paper, we propose an improved SO-PMI (Semantic Orientation Using Pointwise Mutual Information) algorithm, for use in Japanese Weblog Opinion Mining. SO-PMI is an unsupervised approach proposed by Turney that has been shown to work well for English. When this algorithm was translated into Japanese naively, most phrases, whether positive or negative in meaning, received a negative SO. For dealing with this slanting phenomenon, we propose three improvements: to expand the reference words to sets of words, to introduce a balancing factor and to detect neutral expressions. In our experiments, the proposed improvements obtained a well-balanced result: both positive and negative accuracy exceeded 62%, when evaluated on 1,200 opinion sentences sampled from three different domains (reviews of Electronic Products, Cars and Travels from Kakaku.com). In a comparative experiment on the same corpus, a supervised approach (SA-Demo) achieved a very similar accuracy to our method. This shows that our proposed approach effectively adapted SO-PMI for Japanese, and it also shows the generality of SO-PMI.

  • Joint Receive Antenna Selection for Multi-User MIMO Systems with Vector Precoding

    Wei MIAO  Yunzhou LI  Shidong ZHOU  Jing WANG  Xibin XU  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:4
      Page(s):
    1176-1179

    Vector precoding is a nonlinear broadcast precoding scheme in the downlink of multi-user MIMO systems which outperforms linear precoding and THP (Tomlinson-Harashima Precoding). This letter discusses the problem of joint receive antenna selection in the multi-user MIMO downlink with vector precoding. Based on random matrix analysis, we derive a simple heuristic selection criterion using singular value decomposition (SVD) and carry out an exhaustive search to determine for each user which receive antenna should be used. Simulation results reveal that receive antenna selection using our proposed criterion obtains the same diversity order as the optimal selection criterion.

  • Noninvasive Femur Bone Volume Estimation Based on X-Ray Attenuation of a Single Radiographic Image and Medical Knowledge

    Supaporn KIATTISIN  Kosin CHAMNONGTHAI  

     
    PAPER-Biological Engineering

      Vol:
    E91-D No:4
      Page(s):
    1176-1184

    Bone Mineral Density (BMD) is an indicator of osteoporosis that is an increasingly serious disease, particularly for the elderly. To calculate BMD, we need to measure the volume of the femur in a noninvasive way. In this paper, we propose a noninvasive bone volume measurement method using x-ray attenuation on radiography and medical knowledge. The absolute thickness at one reference pixel and the relative thickness at all pixels of the bone in the x-ray image are used to calculate the volume and the BMD. First, the absolute bone thickness of one particular pixel is estimated by the known geometric shape of a specific bone part as medical knowledge. The relative bone thicknesses of all pixels are then calculated by x-ray attenuation of each pixel. Finally, given the absolute bone thickness of the reference pixel, the absolute bone thickness of all pixels is mapped. To evaluate the performance of the proposed method, experiments on 300 subjects were performed. We found that the method provides good estimations of real BMD values of femur bone. Estimates shows a high linear correlation of 0.96 between the volume Bone Mineral Density (vBMD) of CT-SCAN and computed vBMD (all P<0.001). The BMD results reveal 3.23% difference in volume from the BMD of CT-SCAN.

  • Concise Modeling of Transistor Variations in an LSI Chip and Its Application to SRAM Cell Sensitivity Analysis

    Masakazu AOKI  Shin-ichi OHKAWA  Hiroo MASUDA  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E91-C No:4
      Page(s):
    647-654

    Random variations in Id-Vg characteristics of MOS transistors in an LSI chip are shown to be concisely characterized by using only 3 transistor parameters (Vth, β0, vSAT) in the MOS level 3 SPICE model. Statistical analyses of the transistor parameters show that not only the threshold voltage variation, ΔVth, but also the current factor variation, Δβ0, independently induces Id-variation, and that Δβ0 is negatively correlated with the saturation velocity variation, ΔvSAT. Using these results, we have proposed a simple method that effectively takes the correlation between parameters into consideration when creating statistical model parameters for designing a circuit. Furthermore, we have proposed a sensitivity analysis methodology for estimating the process window of SRAM cell operation taking transistor variability into account. By applying the concise statistical model parameters to the sensitivity analysis, we are able to obtain valid process windows without the large volume of data-processing and long turnaround time associated with the Monte Carlo simulation. The process window was limited not only by ΔVth, but also by Δβ0 which enhanced the failure region in the process window by 20%.

  • Physical Database Design for Efficient Time-Series Similarity Search

    Sang-Wook KIM  Jinho KIM  Sanghyun PARK  

     
    LETTER-Multimedia Systems for Communications

      Vol:
    E91-B No:4
      Page(s):
    1251-1254

    Similarity search in time-series databases finds such data sequences whose changing patterns are similar to that of a query sequence. For efficient processing, it normally employs a multi-dimensional index. In order to alleviate the well-known dimensionality curse, the previous methods for similarity search apply the Discrete Fourier Transform (DFT) to data sequences, and take only the first two or three DFT coefficients as organizing attributes. Other than this ad-hoc approach, there have been no research efforts on devising a systematic guideline for choosing the best organizing attributes. This paper first points out the problems occurring in the previous methods, and proposes a novel solution to construct optimal multi-dimensional indexes. The proposed method analyzes the characteristics of a target time-series database, and identifies the organizing attributes having the best discrimination power. It also determines the optimal number of organizing attributes for efficient similarity search by using a cost model. Through a series of experiments, we show that the proposed method outperforms the previous ones significantly.

  • Low Static Powered Asynchronous Data Transfer for GALS System

    Myeong-Hoon OH  Seongwoon KIM  

     
    LETTER-VLSI Systems

      Vol:
    E91-D No:4
      Page(s):
    1189-1192

    For a globally asynchronous locally synchronous (GALS) system, data transfer mechanisms based on a current-mode multiple valued logic (CMMVL) has been studied to reduce complexity and power dissipation of wires. However, these schemes consume considerable amount of power even in idle states because of the static power caused by their inherent structure. In this paper, new encoder and decoder circuits using CMMVL are suggested to reduce the static power. The effectiveness of the proposed data transfer is validated by comparisons with the previous CMMVL scheme and conventional voltage-mode schemes such as dual-rail and 1-of-4 encodings through simulation with a 0.25-µm CMOS technology. Simulation results demonstrate that the proposed CMMVL scheme significantly reduces power consumption of the previous one and is superior to dual-rail and 1-of-4 schemes over wire length of 2 mm and 4 mm, respectively.

  • Performance Comparison of Binary Search Tree and Framed ALOHA Algorithms for RFID Anti-Collision

    Wen-Tzu CHEN  

     
    LETTER-Network

      Vol:
    E91-B No:4
      Page(s):
    1168-1171

    Binary search tree and framed ALOHA algorithms are commonly adopted to solve the anti-collision problem in RFID systems. In this letter, the read efficiency of these two anti-collision algorithms is compared through computer simulations. Simulation results indicate the framed ALOHA algorithm requires less total read time than the binary search tree algorithm. The initial frame length strongly affects the uplink throughput for the framed ALOHA algorithm.

  • Packet Detection for Zero-Padded OFDM Transmission

    Kyu-Min KANG  

     
    LETTER-Transmission Systems and Transmission Equipment for Communications

      Vol:
    E91-B No:4
      Page(s):
    1158-1160

    A packet detection method for zero-padded orthogonal frequency division multiplexing (OFDM) transmission is presented. The proposed algorithm effectively conducts packet detection by employing both an M-sample time delayed cross correlation value, and a received signal power calculated by using the received input samples corresponding to the zero padding (ZP) intervals or less.

  • A Necessary Condition for Gauss Period Normal Bases to Be the Same Normal Basis

    Yasuyuki NOGAMI  Ryo NAMBA  Yoshitaka MORIKAWA  

     
    LETTER-Cryptography and Information Security

      Vol:
    E91-A No:4
      Page(s):
    1229-1232

    This paper shows a necessary condition for type- and Gauss period normal bases in Fpm to be the same normal basis by using their traces.

  • A Fuzzy Method for Medical Diagnosis of Headache

    Jeong-Yong AHN  Kill-Sung MUN  Young-Hyun KIM  Sun-Young OH  Beom-Soo HAN  

     
    LETTER-Biological Engineering

      Vol:
    E91-D No:4
      Page(s):
    1215-1217

    In this note we propose a fuzzy diagnosis of headache. The method is based on the relations between symptoms and diseases. For this purpose, we suggest a new diagnosis measure using the occurrence information of patient's symptoms and develop an improved interview chart with fuzzy degrees assigned according to the relation among symptoms and three labels of headache. The proposed method is illustrated by two examples.

9881-9900hit(20498hit)