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5881-5900hit(21534hit)

  • On-Chip Detection of Process Shift and Process Spread for Post-Silicon Diagnosis and Model-Hardware Correlation

    A.K.M. Mahfuzul ISLAM  Hidetoshi ONODERA  

     
    PAPER

      Vol:
    E96-D No:9
      Page(s):
    1971-1979

    This paper proposes the use of on-chip monitor circuits to detect process shift and process spread for post-silicon diagnosis and model-hardware correlation. The amounts of shift and spread allow test engineers to decide the correct test strategy. Monitor structures suitable for detection of process shift and process spread are discussed. Test chips targeting a nominal process corner as well as 4 other corners of “slow-slow”, “fast-fast”, “slow-fast” and “fast-slow” are fabricated in a 65nm process. The monitor structures correctly detects the location of each chip in the process space. The outputs of the monitor structures are further analyzed and decomposed into the process variations in threshold voltage and gate length for model-hardware correlation. Path delay predictions match closely with the silicon values using the extracted parameter shifts. On-chip monitors capable of detecting process shift and process spread are helpful for performance prediction of digital and analog circuits, adaptive delay testing and post-silicon statistical analysis.

  • An Estimation Method of Sound Source Orientation Using Eigenspace Variation of Spatial Correlation Matrix

    Kenta NIWA  Yusuke HIOKA  Sumitaka SAKAUCHI  Ken'ichi FURUYA  Yoichi HANEDA  

     
    PAPER-Engineering Acoustics

      Vol:
    E96-A No:9
      Page(s):
    1831-1839

    A method to estimate sound source orientation in a reverberant room using a microphone array is proposed. We extend the conventional modeling of a room transfer function based on the image method in order to take into account the directivity of a sound source. With this extension, a transfer function between a sound source and a listener (or a microphone) is described by the superposition of transfer functions from each image source to the listener multiplied by the source directivity; thus, the sound source orientation can be estimated by analyzing how the image sources are distributed (power distribution of image sources) from observed signals. We applied eigenvalue analysis to the spatial correlation matrix of the microphone array observation to obtain the power distribution of image sources. Bsed on the assumption that the spatial correlation matrix for each set of source position and orientation is known a priori, the variation of the eigenspace can be modeled. By comparing the eigenspace of observed signals and that of pre-learned models, we estimated the sound source orientation. Through experiments using seven microphones, the sound source orientation was estimated with high accuracy by increasing the reverberation time of a room.

  • Throughput/ACLR Performance of CF-Based Adaptive PAPR Reduction Method for Eigenmode MIMO-OFDM Signals with AMC

    Shoki INOUE  Teruo KAWAMURA  Kenichi HIGUCHI  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E96-B No:9
      Page(s):
    2293-2300

    This paper proposes an enhancement to a previously reported adaptive peak-to-average power ratio (PAPR) reduction method based on clipping and filtering (CF) for eigenmode multiple-input multiple-output (MIMO) — orthogonal frequency division multiplexing (OFDM) signals. We enhance the method to accommodate the case with adaptive modulation and channel coding (AMC). Since the PAPR reduction process degrades the signal-to-interference and noise power ratio (SINR), the AMC should take into account this degradation before PAPR reduction to select accurately the modulation scheme and coding rate (MCS) for each spatial stream. We use the lookup table-based prediction of SINR after PAPR reduction, in which the interference caused by the PAPR reduction is obtained as a function of the stream index, frequency block index, clipping threshold for PAPR reduction, and input backoff (IBO) of the power amplifier. Simulation results show that the proposed PAPR reduction method increases the average throughput compared to the conventional CF method for a given adjacent channel leakage power ratio (ACLR) when we assume practical AMC.

  • Scan-Out Power Reduction for Logic BIST

    Senling WANG  Yasuo SATO  Seiji KAJIHARA  Kohei MIYASE  

     
    PAPER

      Vol:
    E96-D No:9
      Page(s):
    2012-2020

    In this paper we propose a novel method to reduce power consumption during scan testing caused by test responses at scan-out operation for logic BIST. The proposed method overwrites some flip-flops (FFs) values before starting scan-shift so as to reduce the switching activity at scan-out operation. In order to relax the fault coverage loss caused by filling new FF values before observing the capture values at the FFs, the method employs multi-cycle scan test with partial observation. For deriving larger scan-out power reduction with less fault coverage loss and preventing hardware overhead increase, the FFs to be filled are selected in a predetermined ratio. For overwriting values, we prepare three value filling methods so as to achieve larger scan-out power reduction. Experiment for ITC99 benchmark circuits shows the effectiveness of the methods. Nearly 51% reduction of scan-out power and 57% reduction of peak scan-out power are achieved with little fault coverage loss for 20% FFs selection, while hardware overhead is little that only 0.05%.

  • A Novel Pattern Run-Length Coding Method for Test Data Compression

    Diancheng WU  Yu LIU  Hao ZHU  Donghui WANG  Chengpeng HAO  

     
    BRIEF PAPER-Integrated Electronics

      Vol:
    E96-C No:9
      Page(s):
    1201-1204

    This paper presents a novel data compression method for testing integrated circuits within the framework of pattern run-length coding. The test set is firstly divided into 2n-length patterns where n is a natural number. Then the compatibility of each pattern, which can be an external type, or an internal type, is analyzed. At last, the codeword of each pattern is generated according to its analysis result. Experimental results for large ISCAS89 benchmarks show that the proposed method can obtain a higher compression ratio than existing ones.

  • New Quaternary Sequences with Ideal Autocorrelation Constructed from Legendre Sequences

    Young-Sik KIM  Ji-Woong JANG  Sang-Hyo KIM  Jong-Seon NO  

     
    PAPER-Spread Spectrum Technologies and Applications

      Vol:
    E96-A No:9
      Page(s):
    1872-1882

    In this paper, for an odd prime p, new quaternary sequences of even period 2p with ideal autocorrelation property are constructed using the binary Legendre sequences of period p. For the new quaternary sequences, two properties which are considered as the major characteristics of pseudo-random sequences are derived. Firstly, the autocorrelation distribution of the proposed quaternary sequences is derived and it is shown that the autocorrelation values of the proposed quaternary sequences are optimal. For both p≡1 mod 4 and p≡3 mod 4, we can construct optimal quaternary sequences while only for p≡3 mod 4, the binary Legendre sequences can satisfy ideal autocorrelation property. Secondly, the linear complexity of the proposed quaternary sequences is also derived by counting non-zero coefficients of the discrete Fourier transform over the finite field Fq which is the splitting field of x2p-1. It is shown that the linear complexity of the quaternary sequences is larger than or equal to p or (3p+1)/2 for p≡1 mod 4 or p≡3 mod 4, respectively.

  • Influence of the Splitter Plates on the High Current Air Arc in Low Voltage Circuit Breaker

    Hongwu LIU  Ruiliang GUAN  Nairui YIN  Xinyi XIE  Degui CHEN  

     
    PAPER

      Vol:
    E96-C No:9
      Page(s):
    1119-1123

    The influence of the splitter plates on the high-current arc roots formation in low voltage circuit breaker is investigated. One arc quenching chamber model is designed, where the shape of the splitter plates can be changed. The capacitor bank circuit is used to provide the test power supply, and the effective value of the prospective short circuit current is fixed to 10kA. High speed CCD camera is adopted to record the arc images during the arcing duration. Arc current and voltage are also measured to analyze the arc characteristics. In addition, a simplified 1-D thermal-electric model is developed to investigate the influence of the splitter plates on the distribution of the current density of the arc plasma with the assumption of local thermal equilibrium (LTE). It shows that the distance between the arc initial ignition location and the splitter plates is crucial to the arc root formation.

  • A Fuzzy Geometric Active Contour Method for Image Segmentation

    Danyi LI  Weifeng LI  Qingmin LIAO  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E96-D No:9
      Page(s):
    2107-2114

    In this paper, we propose a hybrid fuzzy geometric active contour method, which embeds the spatial fuzzy clustering into the evolution of geometric active contour. In every iteration, the evolving curve works as a spatial constraint on the fuzzy clustering, and the clustering result is utilized to construct the fuzzy region force. On one hand, the fuzzy region force provides a powerful capability to avoid the leakages at weak boundaries and enhances the robustness to various noises. On the other hand, the local information obtained from the gradient feature map contributes to locating the object boundaries accurately and improves the performance on the images with heterogeneous foreground or background. Experimental results on synthetic and real images have shown that our model can precisely extract object boundaries and perform better than the existing representative hybrid active contour approaches.

  • A Real-Time Hand Pose Recognition Method with Hidden Finger Prediction

    Min-Young NA  Tae-Young KIM  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E96-D No:9
      Page(s):
    2170-2173

    In this paper, we present a real-time hand pose recognition method to provide an intuitive user interface through hand poses or gestures without a keyboard and a mouse. For this, the areas of right and left hands are segmented from the depth camera image, and noise compensation is performed. Then, the rotation angle and the centroid point of each hand area are calculated. Subsequently, joint points and end points of a finger are detected by expanding a circle at regular intervals from a centroid point of the hand. Lastly, the hand pose is recognized by matching between the current hand information and the hand model of previous frame and the hand model is updated for the next frame. This method enables users to predict the hidden fingers through the hand model information of the previous frame using temporal coherence in consecutive frames. As a result of the experiment on various hand poses with the hidden fingers using both hands, the accuracy showed over 95% and the performance indicated over 32fps. The proposed method can be used as a contactless input interface in presentation, advertisement, education, and game applications.

  • High-Accuracy and Quick Matting Based on Sample-Pair Refinement and Local Optimization

    Bei HE  Guijin WANG  Chenbo SHI  Xuanwu YIN  Bo LIU  Xinggang LIN  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E96-D No:9
      Page(s):
    2096-2106

    Based on sample-pair refinement and local optimization, this paper proposes a high-accuracy and quick matting algorithm. First, in order to gather foreground/background samples effectively, we shoot rays in hybrid (gradient and uniform) directions. This strategy utilizes the prior knowledge to adjust the directions for effective searching. Second, we refine sample-pairs of pixels by taking into account neighbors'. Both high confidence sample-pairs and usable foreground/background components are utilized and thus more accurate and smoother matting results are achieved. Third, to reduce the computational cost of sample-pair selection in coarse matting, this paper proposes an adaptive sample clustering approach. Most redundant samples are eliminated adaptively, where the computational cost decreases significantly. Finally, we convert fine matting into a de-noising problem, which is optimized by minimizing the observation and state errors iteratively and locally. This leads to less space and time complexity compared with global optimization. Experiments demonstrate that we outperform other state-of-the-art methods in local matting both on accuracy and efficiency.

  • Finger Vein Recognition with Gabor Wavelets and Local Binary Patterns

    Jialiang PENG  Qiong LI  Ahmed A. ABD EL-LATIF  Ning WANG  Xiamu NIU  

     
    LETTER-Pattern Recognition

      Vol:
    E96-D No:8
      Page(s):
    1886-1889

    In this paper, a new finger vein recognition method based on Gabor wavelet and Local Binary Pattern (GLBP) is proposed. In the new scheme, Gabor wavelet magnitude and Local Binary Pattern operator are combined, so the new feature vector has excellent stability. We introduce Block-based Linear Discriminant Analysis (BLDA) to reduce the dimensionality of the GLBP feature vector and enhance its discriminability at the same time. The results of an experiment show that the proposed approach has excellent performance compared to other competitive approaches in current literatures.

  • A Practical Terrain Generation Method Using Sketch Map and Simple Parameters

    Hua Fei YIN  Chang Wen ZHENG  

     
    PAPER-Computer Graphics

      Vol:
    E96-D No:8
      Page(s):
    1836-1844

    A procedural terrain generation method is presented in this paper. It uses a user-drawn sketch map, which is a raster image with lines and polygons painted by different colors to represent sketches of different terrain features, as input to control the placement of terrain features. Some simple parameters which can be easily understood and adjusted by users are used to control the generation process. To further automatically generate terrains, a mechanism that automatically generates sketches is also put forward. The method is implemented in a PC, and experiments show that terrains are generated efficiently. This method provides users a controllable way to generate terrains.

  • Comparative Study on Required Bit Depth of Gamma Quantization for Digital Cinema Using Contrast and Color Difference Sensitivities

    Junji SUZUKI  Isao FURUKAWA  

     
    PAPER-Image

      Vol:
    E96-A No:8
      Page(s):
    1759-1767

    A specification for digital cinema systems which deal with movies digitally from production to delivery as well as projection on the screens is recommended by DCI (Digital Cinema Initiative), and the systems based on this specification have already been developed and installed in theaters. The parameters of the systems that play an important role in determining image quality include image resolution, quantization bit depth, color space, gamma characteristics, and data compression methods. This paper comparatively discusses a relation between required bit depth and gamma quantization using both of a human visual system for grayscale images and two color difference models for color images. The required bit depth obtained from a contrast sensitivity function against grayscale images monotonically decreases as the gamma value increases, while it has a minimum value when the gamma is 2.9 to 3.0 from both of the CIE 1976 L* a* b* and CIEDE2000 color difference models. It is also shown that the bit depth derived from the contrast sensitivity function is one bit greater than that derived from the color difference models at the gamma value of 2.6. Moreover, a comparison between the color differences computed with the CIE 1976 L* a* b* and CIEDE2000 leads to a same result from the view point of the required bit depth for digital cinema systems.

  • Synthesis of Configuration Change Procedure Using Model Finder

    Shinji KIKUCHI  Satoshi TSUCHIYA  Kunihiko HIRAISHI  

     
    PAPER-Software System

      Vol:
    E96-D No:8
      Page(s):
    1696-1706

    Managing the configurations of complex systems consisting of various components requires the combined efforts by multiple domain experts. These experts have extensive knowledge about different components in the system they need to manage but little understanding of the issues outside their individual areas of expertise. As a result, the configuration constraints, changes, and procedures specified by those involved in the management of a complex system are often interrelated with one another without being noticed, and their integration into a coherent procedure for configuration represents a major challenge. The method of synthesizing the configuration procedure introduced in this paper addresses this challenge using a combination of formal specification and model finding techniques. We express the knowledge on system management with this method, which is provided by domain experts as first-order logic formulas in the Alloy specification language, and combine it with system-configuration information and the resulting specification. We then employ the Alloy Analyzer to find a system model that satisfies all the formulas in this specification. The model obtained corresponds to a procedure for system configurations that satisfies all expert-specified constraints. In order to reduce the resources needed in the procedure synthesis, we reduce the length of procedures to be synthesized by defining and using intermediate goal states to divide operation procedures into shorter steps. Finally, we evaluate our method through a case study on a procedure to consolidate virtual machines.

  • Ray-Model-Based Routing for Underwater Acoustic Sensor Networks Accounting for Anisotropic Sound Propagation

    Ping WANG  Lin ZHANG  Victor O.K. LI  

     
    PAPER-Network

      Vol:
    E96-B No:8
      Page(s):
    2060-2068

    In classical routing protocols, geographical distances/locations are typically used as the metric to select the best route, under the assumption that shorter distances exhibit lower energy consumption and nodes within the communication range of the sender can receive packets with a certain success probability. However, in underwater acoustic sensor networks (UASNs), sound propagation in the ocean medium is more complex than that in the air due to many factors, including sound speed variations and the interaction of sound waves with the sea surface and floor, causing the sound rays to bend. Therefore, propagation of sound is anisotropic in water, and may cause a phenomenon called shadow zone where nodes in the communication range of the sender cannot hear any signal. This renders conventional routing protocols no longer energy-efficient. In this paper, we make use of the ray-model to account for the environment-dependent behavior of the underwater channel, re-define nodes' one-hop neighbors based on signal attenuation rather than geographical distance, and design a distributed energy-efficient routing protocol for UASNs. Results show that our ray-model-based routing policy consistently outperforms the shortest path policy, and performs very close to the optimal one in several scenarios.

  • Selecting Effective and Discriminative Spatio-Temporal Interest Points for Recognizing Human Action

    Hongbo ZHANG  Shaozi LI  Songzhi SU  Shu-Yuan CHEN  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E96-D No:8
      Page(s):
    1783-1792

    Many successful methods for recognizing human action are spatio-temporal interest point (STIP) based methods. Given a test video sequence, for a matching-based method using a voting mechanism, each test STIP casts a vote for each action class based on its mutual information with respect to the respective class, which is measured in terms of class likelihood probability. Therefore, two issues should be addressed to improve the accuracy of action recognition. First, effective STIPs in the training set must be selected as references for accurately estimating probability. Second, discriminative STIPs in the test set must be selected for voting. This work uses ε-nearest neighbors as effective STIPs for estimating the class probability and uses a variance filter for selecting discriminative STIPs. Experimental results verify that the proposed method is more accurate than existing action recognition methods.

  • A Fast Power Estimation Method for Content Addressable Memory by Using SystemC Simulation Environment

    Kun-Lin TSAI  I-Jui TUNG  Feipei LAI  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E96-A No:8
      Page(s):
    1723-1729

    Content addressable memory is widely used for fast lookup table data searching, but it often consumes considerable power. Moreover, designing the suitable content addressable memory architecture for a specific application also consumes lots of time, since the behavioral simulation is often done in the transistor level. SystemC is a system-level modeling language and simulation platform, providing high simulation efficiency for hardware software co-design. Unfortunately, SystemC does not provide the function for estimating power dissipation of a structure design. In this paper, a SystemC-based fast content addressable memory power estimation method is presented for estimating the power dissipation of the match-line circuit, the search-line circuit, and the storage cell array of content addressable memory in the early design stage. The mathematical equations and behavioral patterns are used as the inputs of power estimation model. The simulation results based on 10 Mibench benchmarks show that the simulation time of the proposed method is in average 1233 times faster than that of HSPICE simulator with only 3.51% error rate.

  • M-Shaped Dielectric Phase Shifter for Beam-Steerable Base-Station Antenna

    Kengo NISHIMOTO  Takeshi OSHIMA  Toru FUKASAWA  Hiroaki MIYASHITA  Yoshihiko KONISHI  Manabu KURIHARA  Yoshiyuki CHATANI  

     
    PAPER-Antennas and Propagation

      Vol:
    E96-B No:8
      Page(s):
    2095-2101

    We propose a simple and small phase shifter for a beam-steerable base-station antenna. This phase shifter has no metallic heterojunction, and the phase shift is controlled by moving an M-shaped dielectric plate between the strip conductor and the ground plane of a strip line. We derive a design equation from the condition that at the center frequency f0, the reflection coefficient = 0. In this phase shifter, the reflection coefficient becomes minimum at f0 regardless of the movement distance, r, of the dielectric plate, and the relationship between the phase shift and r is linear. These characteristics are verified by performing simulations and measurements. The size of the M-shaped dielectric phase shifter is 0.27λ00.12λ0, where λ0 is the free-space wavelength at f0. The insertion loss is smaller than about 0.2 dB within a fractional bandwidth of 10%, and the phase shift can vary from 0 to about 80 degrees.

  • Generation of Moire-Picture-Like Color Images by Bilateral Filter

    Toru HIRAOKA  Kiichi URAHAMA  

     
    LETTER-Fundamentals of Information Systems

      Vol:
    E96-D No:8
      Page(s):
    1862-1866

    We propose a non-photorealistic rendering method for generating moire-picture-like color images from color photographs. The proposed method is performed in two steps. First, images with a staircasing effect are generated by a bilateral filter. Second, moire patterns are generated with an improved bilateral filter called an anti-bilateral filter. The characteristic of the anti-bilateral filter is to emphasize gradual boundaries.

  • Nonlinear Integer Programming Formulation for Quasi-Optimal Grouping of Clusters in Ferry-Assisted DTNs

    Masahiro SASABE  K. Habibul KABIR  Tetsuya TAKINE  

     
    PAPER-Network

      Vol:
    E96-B No:8
      Page(s):
    2076-2083

    Communication among isolated networks (clusters) in delay tolerant networks (DTNs) can be supported by a message ferry, which collects bundles from clusters and delivers them to a sink node. When there are lots of distant static clusters, multiple message ferries and sink nodes will be required. In this paper, we aim to make groups, each of which consists of physically close clusters, a sink node, and a message ferry. Our objective is minimizing the overall mean delivery delay of bundles in consideration of both the offered load of clusters and distances between clusters and their sink nodes. Based on existing work, we first model this problem as a nonlinear integer programming. Using a commercial nonlinear solver, we obtain a quasi-optimal grouping. Through numerical evaluations, we show the fundamental characteristics of grouping, the impact of location limitation of base clusters, and the relationship between delivery delay and the number of base clusters.

5881-5900hit(21534hit)