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[Keyword] capture(47hit)

21-40hit(47hit)

  • Software Reliability Modeling Based on Capture-Recapture Sampling

    Hiroyuki OKAMURA  Tadashi DOHI  

     
    PAPER

      Vol:
    E92-A No:7
      Page(s):
    1615-1622

    This paper proposes a dynamic capture-recapture (DCR) model to estimate not only the total number of software faults but also quantitative software reliability from observed data. Compared to conventional static capture-recapture (SCR) model and usual software reliability models (SRMs) in the past literature, the DCR model can handle dynamic behavior of software fault-detection processes and can evaluate quantitative software reliability based on capture-recapture sampling of software fault data. This is regarded as a unified modeling framework of SCR and SRM with the Bayesian estimation. Simulation experiments under some plausible testing scenarios show that our models are superior to SCR and SRMs in terms of estimation accuracy.

  • Combined Effect of Random Transmit Power Control and Inter-Path Interference Cancellation on DS-CDMA Packet Mobile Communications

    Eisuke KUDOH  Haruki ITO  ZhiSen WANG  Fumiyuki ADACHI  

     
    PAPER

      Vol:
    E91-A No:7
      Page(s):
    1589-1596

    In mobile communication systems, high speed packet data services are demanded. In the high speed data transmission, throughput degrades severely due to severe inter-path interference (IPI). Recently, we proposed a random transmit power control (TPC) to increase the uplink throughput of DS-CDMA packet mobile communications. In this paper, we apply IPI cancellation in addition to the random TPC. We derive the numerical expression of the received signal-to-interference plus noise power ratio (SINR) and introduce IPI cancellation factor. We also derive the numerical expression of system throughput when IPI is cancelled ideally to compare with the Monte Carlo numerically evaluated system throughput. Then we evaluate, by Monte-Carlo numerical computation method, the combined effect of random TPC and IPI cancellation on the uplink throughput of DS-CDMA packet mobile communications.

  • A Single Camera Motion Capture System for Human-Computer Interaction

    Ryuzo OKADA  Bjorn STENGER  

     
    PAPER

      Vol:
    E91-D No:7
      Page(s):
    1855-1862

    This paper presents a method for markerless human motion capture using a single camera. It uses tree-based filtering to efficiently propagate a probability distribution over poses of a 3D body model. The pose vectors and associated shapes are arranged in a tree, which is constructed by hierarchical pairwise clustering, in order to efficiently evaluate the likelihood in each frame. A new likelihood function based on silhouette matching is proposed that improves the pose estimation of thinner body parts, i.e. the limbs. The dynamic model takes self-occlusion into account by increasing the variance of occluded body-parts, thus allowing for recovery when the body part reappears. We present two applications of our method that work in real-time on a Cell Broadband EngineTM: a computer game and a virtual clothing application.

  • Power Reduction during Scan Testing Based on Multiple Capture Technique

    Lung-Jen LEE  Wang-Dauh TSENG  Rung-Bin LIN  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E91-C No:5
      Page(s):
    798-805

    In this paper, we present a multiple capture approach to reducing the peak power as well as average power consumption during testing. The basic idea behind is to divide a scan chain into two sub-scan chains, and only one sub-scan chain will be enabled at a time during the scan shift or capture operations. We develop a pattern insertion technique to efficiently deal with the capture violation problem during the capture cycle. In order to alleviate the timing cost due to the insertion of redundant patterns, a scan chain partitioning method incorporated with test pattern reordering is developed to reduce the testing time. Experimental results for large ISCAS'89 benchmark circuits show that the proposed approach can efficiently reduce peak and average power with little timing overhead.

  • 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.

  • Self-Resetting Level-Conversion Flip-Flops with Direct Output Feedback for Dual-Supply SoCs

    Joo-Seong KIM  Bai-Sun KONG  

     
    LETTER-Electronic Circuits

      Vol:
    E91-C No:2
      Page(s):
    240-243

    This paper describes novel CMOS level-conversion flip-flops for use in low-power SoCs with clustered voltage scaling. These flip-flops feed outputs directly into the front stage to support self-resetting and conditional operations. They thus have simple structures to avoid clock level shifting and redundant transitions, leading to substantial improvements in terms of power and area. The comparison results indicate that the proposed level-conversion flip-flops achieve power and area savings up to 50% and 31%, respectively, with no speed degradation as compared to conventional level-conversion flip-flops.

  • A Novel ATPG Method for Capture Power Reduction during Scan Testing

    Xiaoqing WEN  Seiji KAJIHARA  Kohei MIYASE  Tatsuya SUZUKI  Kewal K. SALUJA  Laung-Terng WANG  Kozo KINOSHITA  

     
    PAPER-Dependable Computing

      Vol:
    E90-D No:9
      Page(s):
    1398-1405

    High power dissipation can occur when the response to a test vector is captured by flip-flops in scan testing, resulting in excessive IR drop, which may cause significant capture-induced yield loss in the DSM era. This paper addresses this serious problem with a novel test generation method, featuring a unique algorithm that deterministically generates test cubes not only for fault detection but also for capture power reduction. Compared with previous methods that passively conduct X-filling for unspecified bits in test cubes generated only for fault detection, the new method achieves more capture power reduction with less test set inflation. Experimental results show its effectiveness.

  • Collision Recovery for OFDM System over Wireless Channel

    Yafei HOU  Masanori HAMAMURA  

     
    PAPER

      Vol:
    E90-A No:7
      Page(s):
    1312-1322

    We present an effective method of collision recovery for orthogonal frequency division multiplexing (OFDM)-based communications. For the OFDM system, the modulated message data can be demodulated using the partial time-domain OFDM signal. Therefore, the partial time-domain signal can be adopted to reconstruct the whole OFDM time-domain signal with estimated channel information. This property can be utilized to recover packets from the collisions. Since most collisions are cases in which a long packet collides with a short packet, the collided part is assumed to be short. The simulated results show that the method can recover the two collided packets with a certain probability and can be developed to solve the problem of hidden terminals. This method will dramatically benefit the protocol design of wireless networks, including ad hoc and sensor networks.

  • A New Method for Low-Capture-Power Test Generation for Scan Testing

    Xiaoqing WEN  Yoshiyuki YAMASHITA  Seiji KAJIHARA  Laung-Terng WANG  Kewal K. SALUJA  Kozo KINOSHITA  

     
    PAPER-Dependable Computing

      Vol:
    E89-D No:5
      Page(s):
    1679-1686

    Research on low-power scan testing has been focused on the shift mode, with little consideration given to the capture mode power. However, high switching activity when capturing a test response can cause excessive IR-drop, resulting in significant yield loss due to faulty test results. This paper addresses this problem with a novel low-capture-power X-filling method by assigning 0's and 1's to unspecified bits (X-bits) in a test cube to reduce the switching activity in capture mode. This method can be easily incorporated into any test generation flow, where test cubes can be obtained during ATPG or by X-bit identification. Experimental results show the effectiveness of this method in reducing capture power dissipation without any impact on area, timing, and fault coverage.

  • Human Walking Motion Synthesis with Desired Pace and Stride Length Based on HSMM

    Naotake NIWASE  Junichi YAMAGISHI  Takao KOBAYASHI  

     
    PAPER

      Vol:
    E88-D No:11
      Page(s):
    2492-2499

    This paper presents a new technique for automatically synthesizing human walking motion. In the technique, a set of fundamental motion units called motion primitives is defined and each primitive is modeled statistically from motion capture data using a hidden semi-Markov model (HSMM), which is a hidden Markov model (HMM) with explicit state duration probability distributions. The mean parameter for the probability distribution function of HSMM is assumed to be given by a function of factors that control the walking pace and stride length, and a training algorithm, called factor adaptive training, is derived based on the EM algorithm. A parameter generation algorithm from motion primitive HSMMs with given control factors is also described. Experimental results for generating walking motion are presented when the walking pace and stride length are changed. The results show that the proposing technique can generate smooth and realistic motion, which are not included in the motion capture data, without the need for smoothing or interpolation.

  • Construction of Audio-Visual Speech Corpus Using Motion-Capture System and Corpus Based Facial Animation

    Tatsuo YOTSUKURA  Shigeo MORISHIMA  Satoshi NAKAMURA  

     
    PAPER

      Vol:
    E88-D No:11
      Page(s):
    2477-2483

    An accurate audio-visual speech corpus is inevitable for talking-heads research. This paper presents our audio-visual speech corpus collection and proposes a head-movement normalization method and a facial motion generation method. The audio-visual corpus contains speech data, movie data on faces, and positions and movements of facial organs. The corpus consists of Japanese phoneme-balanced sentences uttered by a female native speaker. An accurate facial capture is realized by using an optical motion-capture system. We captured high-resolution 3D data by arranging many markers on the speaker's face. In addition, we propose a method of acquiring the facial movements and removing head movements by using affine transformation for computing displacements of pure facial organs. Finally, in order to easily create facial animation from this motion data, we propose a technique assigning the captured data to the facial polygon model. Evaluation results demonstrate the effectiveness of the proposed facial motion generation method and show the relationship between the number of markers and errors.

  • Virtual-FIFO Back-Off Algorithm for Collision Resolution in Wireless Networks

    Chih-Peng LI  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E88-B No:10
      Page(s):
    4056-4063

    This investigation proposes a virtual-FIFO (VFIFO) back-off algorithm for wireless networks. The proposed scheme takes advantage of the central unit (CU) in a wireless network to broadcast a common back-off window size to all the users, significantly alleviating the unfairness of bandwidth utilization in conventional binary exponential back-off (BEB) algorithms. The proposed scheme exploits the CU's capability for collision detection to estimate the number of simultaneously competing users. Additionally, packets generated in a given cycle are split into groups according to their times of arrivals and are guaranteed to be serviced one after another within the next cycle. Although the proposed algorithm is not strictly first come fist served, the FIFO principle is virtually accomplished. Simulation results demonstrate that the standard deviation of delay can be improved by more than two orders and the throughput can be maintained at 0.42 when the number of users approaches infinity. The capture effect even further improves system performance.

  • On Rake Reception of Ultra Wideband Signals over Multipath Channels from Energy Capture Perspective

    Mohammad Azizur RAHMAN  Shigenobu SASAKI  Jie ZHOU  Hisakazu KIKUCHI  

     
    PAPER-RAKE Receiver

      Vol:
    E88-A No:9
      Page(s):
    2339-2349

    Performance of Rake reception of Ultra Wideband (UWB) signals is evaluated from energy capture perspective. In addition to ordinary all Rake (ARake) and selective Rake (SRake) receivers which are considered in conventional spread spectrum communications, we introduce optimum ARake and SRake receivers which include the estimation of delay of the combining multipaths. Impact of pulse-width is discussed on their performances considering the relationship between pulse-width and fading. Time hopping M-ary pulse position modulation (TH-MPPM) and binary phase shift keying (TH-BPSK) are considered as modulation schemes. Extensive simulation results are presented showing the performances of the Rakes introduced using IEEE 802.15.3a UWB channel models (CM1 to CM3). Performance of MPPM is shown for various values of M and modulation parameters. The impact of pulse-width is illustrated mainly using BPSK. It is shown that the total energy capture (i.e. by ARake) strongly depends on the pulse-width, and the shorter the pulse-width the more is the amount. The energy capture also varies a lot for employing either optimum or ordinary Raking method. Energy capture by SRake additionally strongly depends on the number of combined paths until the number is 20 for optimum SRake and 10 for ordinary SRake; however, afterwards saturating effects are seen. Several aspects regarding the performance versus complexity issue of Rake receivers are also discussed.

  • Extensible Task Simulation with Motion Archive

    Shigeru KURIYAMA  Tomohiko MUKAI  Yusuke IRINO  Kazuyuki ANDA  Toyohisa KANEKO  

     
    PAPER

      Vol:
    E88-D No:5
      Page(s):
    809-815

    This paper proposes a new framework to produce humanoid animations for simulating human tasks. Natural working movements are generated via management of motion capture data with our simulation package. An extensible middleware controls reactive human behaviors, and all processes of simulation in a cyber factory are controlled through XML documents including motions, scene objects, and behaviors. This package displays simulation using Web3D technology and X3D specifications which can supply a common interface for customizing cyberworlds.

  • Application of Random Transmit Power Control to DS-CDMA/TDD Packet Mobile Radio

    ZhiSen WANG  Eisuke KUDOH  Fumiyuki ADACHI  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E87-B No:10
      Page(s):
    3144-3149

    A random transmit power control (TPC) is applied to DS-CDMA/TDD packet mobile radio, which controls the transmit power so as to intentionally vary the received signal power in order to obtain the large capture effect. The uplink capacity with the random TPC in a frequency-selective fading channel is evaluated by computer simulation. The simulation results show that the random TPC provides larger link capacity than slow TPC.

  • Interpolation and Extrapolation of Repeated Motions Obtained with Magnetic Motion Capture

    Kiyoshi HOSHINO  

     
    PAPER

      Vol:
    E87-A No:9
      Page(s):
    2401-2407

    In this study, a CG animation tool was designed that allows interpolation and extrapolation of two types of repeated motions including finger actions, for quantitative analyses of the relationship between features of human motions and subjective impressions. Three-dimensional human motions are measured with a magnetic motion capture and a pair of data gloves, and then relatively accurate time-series joint data are generated utilizing statistical characteristics. Based on the data thus obtained, time-series angular data of each joint for two dancing motions is transformed into frequency domain by Fourier transform, and spectral shape of each dancing action is interpolated. The interpolation and extrapolation of two motions can be synthesized with simple manner by changing an weight parameter while keeping good harmony of actions. Using this CG animation tool as a motion synthesizer, repeated human motions such as a dancing action that gives particular impressions on the observers can be quantitatively measured and analyzed by the synthesis of actions.

  • Design and Implementation of Markup Language for Integrating of Motion Capture Data Formats

    Hyun-Sook CHUNG  Yillbyung LEE  

     
    PAPER-System Programs

      Vol:
    E87-D No:7
      Page(s):
    1897-1909

    Motion capture technology is widely used to make a realistic motion in these days. Different motion capture devices use different motion capture data formats. Because of the lack of compatibility of motion capture data animators can't reuse the already captured motion sequence. In addition, it is difficult for integrating, storing and retrieving motion capture data with different formats in the storage. In this paper, we propose a standard format for integrating a different motion capture data formats. In addition, we propose a framework of a system that manages motion capture data using our standard format. Our standard format is called MCML (Motion Capture Markup Language). It is a markup language for motion capture data and is based on XML (extensible Markup Language). Our system designed to manage motion capture data consists of a several components -- Mocap Syntax Analyzer, MCML Converter, MCML Editor, Motion Viewer, MCML Storage Wrapper.

  • A Clock and Data Recovery PLL for Variable Bit Rate NRZ Data Using Adaptive Phase Frequency Detector

    Gijun IDEI  Hiroaki KUNIEDA  

     
    PAPER

      Vol:
    E87-C No:6
      Page(s):
    956-963

    An adaptive 4-state phase-frequency detector (PFD) for clock and data recovery (CDR) PLL of non return to zero (NRZ) data is presented. The PLL achieves false-lock free operation with rapid frequency-capture and wide bit-rate-capture range. The variable bit rate operation is achieved by adaptive delay control of data delay. Circuitry and overall architecture are described in detail. A z-Domain analysis is also presented.

  • Uplink Link Capacity of DS-CDMA Packet Mobile Communications with Rake Combining and Transmit Power Control

    ZhiSen WANG  Eisuke KUDOH  Fumiyuki ADACHI  

     
    LETTER-Wireless Communication Technology

      Vol:
    E86-B No:7
      Page(s):
    2203-2206

    Without transmit power control (TPC) and Rake combining, the uplink capacity of a direct sequence code division multiple access (DS-CDMA) packet mobile communication system significantly degrades due to the near-far problem and multipath fading. In this letter, assuming a single cell system with an interference-limited channel, the impact of the joint use of Rake combining and TPC on the uplink capacity is evaluated by computer simulation. Slow TPC is found to give a link capacity larger than fast TPC. This is because, with slow TPC, the received signal power variations due to fading remain intact and this results in a larger capture effect.

  • Fast Capture Algorithm of Initial Attitude for Spacecraft Using Reaction Wheels

    Hyunwoo LEE  Dong-Jo PARK  

     
    PAPER-Systems and Control

      Vol:
    E85-A No:10
      Page(s):
    2311-2317

    A fast capture algorithm of the initial attitude is proposed for the spacecraft using reaction wheels. This algorithm is composed of two steps. The first step deals with absorption of the initial angular momentum of the spacecraft into the reaction wheels and the second step a rest-to-reset large angle maneuver for sun tracking. A criterion of the initial attitude capture and a controller for the fast large angle maneuver method are presented under considering constraints of the reaction wheels. Simulation results show that the proposed algorithm has several advantages of the initial attitude capture and fast large angle maneuver. This algorithm can be applied to the near minimum time rotation control of the spacecraft.

21-40hit(47hit)