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2661-2680hit(8214hit)

  • Low-Complexity Soft-ML Detection Algorithm for Modified-DCM in WiMedia UWB Systems

    Kilhwan KIM  Jangyong PARK  Jihun KOO  Yongsuk KIM  Jaeseok KIM  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E96-B No:3
      Page(s):
    910-913

    This letter proposes a low-complexity soft-detection algorithm for modified dual-carrier modulation (MDCM) in WiMedia ultra-wideband (UWB) systems. In order to reduce the complexity of soft-output maximum-likelihood detection (soft-MLD), which gives the optimal performance for MDCM symbols, the proposed algorithm utilizes the following three methods: real/imaginary separation, multiplierless distance calculation, and candidate set reduction. Through these methods, the proposed algorithm reduces the complexity of soft-MLD by 97%, while preventing the deterioration of its optimality. The performance of the proposed algorithm is demonstrated by simulations of 640–1024 Mbps transmission modes of the latest Release 1.5 standard of the WiMedia UWB.

  • Orientation Imaging of Single Molecule at Various Ambient Conditions

    Toshiki YAMADA  Takahiro KAJI  Akira OTOMO  

     
    BRIEF PAPER

      Vol:
    E96-C No:3
      Page(s):
    381-382

    After brief introduction of our new microscope unit with an immersion objective and ionic liquid used as a refractive index matching medium, in this paper, we describe the studies on dipole orientation imaging of single molecules under high vacuum conditions as one of the important applications of our microscope.

  • Reconstruction Algorithms for Permutation Graphs and Distance-Hereditary Graphs

    Masashi KIYOMI  Toshiki SAITOH  Ryuhei UEHARA  

     
    PAPER

      Vol:
    E96-D No:3
      Page(s):
    426-432

    PREIMAGE CONSTRUCTION problem by Kratsch and Hemaspaandra naturally arose from the famous graph reconstruction conjecture. It deals with the algorithmic aspects of the conjecture. We present an O(n8) time algorithm for PREIMAGE CONSTRUCTION on permutation graphs and an O(n4(n+m)) time algorithm for PREIMAGE CONSTRUCTION on distance-hereditary graphs, where n is the number of graphs in the input, and m is the number of edges in a preimage. Since each graph of the input has n-1 vertices and O(n2) edges, the input size is O(n3) (, or O(nm)). There are polynomial time isomorphism algorithms for permutation graphs and distance-hereditary graphs. However the number of permutation (distance-hereditary) graphs obtained by adding a vertex to a permutation (distance-hereditary) graph is generally exponentially large. Thus exhaustive checking of these graphs does not achieve any polynomial time algorithm. Therefore reducing the number of preimage candidates is the key point.

  • Centralized Gradient Pattern for Face Recognition

    Dong-Ju KIM  Sang-Heon LEE  Myoung-Kyu SHON  

     
    PAPER-Face Perception and Recognition

      Vol:
    E96-D No:3
      Page(s):
    538-549

    This paper proposes a novel face recognition approach using a centralized gradient pattern image and image covariance-based facial feature extraction algorithms, i.e. a two-dimensional principal component analysis and an alternative two-dimensional principal component analysis. The centralized gradient pattern image is obtained by AND operation of a modified center-symmetric local binary pattern image and a modified local directional pattern image, and it is then utilized as input image for the facial feature extraction based on image covariance. To verify the proposed face recognition method, the performance evaluation was carried out using various recognition algorithms on the Yale B, the extended Yale B and the CMU-PIE illumination databases. From the experimental results, the proposed method showed the best recognition accuracy compared to different approaches, and we confirmed that the proposed approach is robust to illumination variation.

  • Refinement of Landmark Detection and Extraction of Articulator-Free Features for Knowledge-Based Speech Recognition

    Jung-In LEE  Jeung-Yoon CHOI  Hong-Goo KANG  

     
    LETTER-Speech and Hearing

      Vol:
    E96-D No:3
      Page(s):
    746-749

    Refinement methods for landmark detection and extraction of articulator-free features for a knowledge-based speech recognition system are described. Sub-band energy difference profiles are used to detect landmarks, with additional parameters used to improve accuracy. For articulator-free feature extraction, duration, relative energy, and silence detection are additionally used to find [continuant] and [strident] features. Vowel, obstruent and sonorant consonant landmarks, and locations of voicing onsets and offsets are detected within a unified framework with 85% accuracy overall. Additionally, 75% and 79% of [continuant] and [strident] features, respectively, are detected from landmarks.

  • Interactive Evolutionary Computation Using a Tabu Search Algorithm

    Hiroshi TAKENOUCHI  Masataka TOKUMARU  Noriaki MURANAKA  

     
    PAPER-Human-computer Interaction

      Vol:
    E96-D No:3
      Page(s):
    673-680

    We present an Interactive Tabu Search (ITS) algorithm to reduce the evaluation load of Interactive Evolutionary Computation (IEC) users. Most previous IEC studies used an evaluation interface that required users to provide evaluation values for all candidate solutions. However, user's burden with such an evaluation interface is large. Therefore, we propose ITS where users choose the favorite candidate solution from the presented candidate solutions. Tabu Search (TS) is recognized as an optimization technique. ITS evaluation is simpler than Interactive Genetic Algorithm (IGA) evaluation, in which users provide evaluation values for all candidate solutions. Therefore, ITS is effective for reducing user evaluation load. We evaluated the performance of our proposed ITS and a Normal IGA (NIGA), which is a conventional 10-stage evaluation, using a numerical simulation with an evaluation agent that imitates human preferences (Kansei). In addition, we implemented an ITS evaluation for a running-shoes-design system and examined its effectiveness through an experiment with real users. The simulation results showed that the evolution performance of ITS is better than that of NIGA. In addition, we conducted an evaluation experiment with 21 subjects in their 20 s to assess the effectiveness of these methods. The results showed that the satisfaction levels for the candidates generated by ITS and NIGA were approximately equal. Moreover, it was easier for test subjects to evaluate candidate solutions with ITS than with NIGA.

  • Risk Assessment of a Portfolio Selection Model Based on a Fuzzy Statistical Test

    Pei-Chun LIN  Junzo WATADA  Berlin WU  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E96-D No:3
      Page(s):
    579-588

    The objective of our research is to build a statistical test that can evaluate different risks of a portfolio selection model with fuzzy data. The central points and radiuses of fuzzy numbers are used to determine the portfolio selection model, and we statistically evaluate the best return by a fuzzy statistical test. Empirical studies are presented to illustrate the risk evaluation of the portfolio selection model with interval values. We conclude that the fuzzy statistical test enables us to evaluate a stable expected return and low risk investment with different choices for k, which indicates the risk level. The results of numerical examples show that our method is suitable for short-term investments.

  • On the Study of a Novel Decision Feedback Equalizer with Block Delay Detection for Joint Transceiver Optimization

    Chun-Hsien WU  

     
    PAPER-Transmission Systems and Transmission Equipment for Communications

      Vol:
    E96-B No:3
      Page(s):
    737-748

    This paper presents a novel decision feedback equalizer (DFE) with block delay detection for the joint transceiver design that uses channel state information (CSI). The block delay detection in the proposed DFE offers a degree of freedom for optimizing the precoder of the transmitter, provided the transmission power is constrained. In the proposed DFE, the feedforward matrix is devised to enable a block-based equalizer that can be cooperated with an intrablock decision feedback equalizer for suppressing the intersymbol interference (ISI) for the transmitted block with a certain block delay. In this design, the interblock interference (IBI) for the delay block is eliminated in advance by applying the recently developed oblique projection framework to the implementation of the feedforward matrix. With knowledge of full CSI, the block delay and the associated block-based precoder are jointly designed such that the average bit-error-rate (BER) is minimized, subject to the transmission power constraint. Separate algorithms are derived for directly determining the BER-minimized block delays for intrablock minimum mean-squared error (MMSE) and zero-forcing (ZF) equalization criteria. Theoretical derivations indicate that the proposed MMSE design simultaneously maximize the Gaussian mutual information of a transceiver, even under the cases of existing IBI. Simulation results validate the proposed DFE for devising an optimum transceiver with CSI, and show the superior BER performance of the optimized transceiver using proposed DFE. Relying on analytic results and simulation cases also builds a sub-optimum MMSE design of the proposed DFE using the BER-minimized block delay for ZF criterion, which exhibits almost identical BER performance as the proposed MMSE design in most of the signal-to-noise ratio (SNR) range.

  • Magnetospinography: Instruments and Application to Functional Imaging of Spinal Cords

    Yoshiaki ADACHI  Daisuke OYAMA  Shigenori KAWABATA  Kensuke SEKIHARA  Yasuhiro HARUTA  Gen UEHARA  

     
    PAPER

      Vol:
    E96-C No:3
      Page(s):
    326-333

    Magnetospinography (MSG) is one of the most promising techniques to detect the nerve activity of spinal cords thanks to its noninvasiveness and high spatial/temporal resolutions. Multichannel superconducting quantum interference device (SQUID) MSG measurement systems optimized for supine subjects have been developed previously and employed in clinical applications in hospitals. Magnetic source analyses of MSG data based on spatial filter techniques reveal the transition of reconstructed current distributions adjacent to the spinal cord. The propagation of the neural signals was noninvasively visualized. The MSG measurements provide significant diagnostic information such as irregularities in the transitions of the reconstructed current distribution and/or considerable decreases in the current intensity at the lesion. Such functional imaging of the spinal cord in addition to conventional neurologic examinations and morphological imaging will be fairly effective in presurgical lesion localizations of the spinal cord.

  • Real-Time Face Detection and Recognition via Local Binary Pattern Plus Sample Selective Biomimetic Pattern Recognition

    Yikui ZHAI  Junying GAN  Jinwen LI  Junying ZENG  Ying XU  

     
    PAPER-Face Perception and Recognition

      Vol:
    E96-D No:3
      Page(s):
    523-530

    Due to security demand of society development, real-time face recognition has been receiving more and more attention nowadays. In this paper, a real-time face recognition system via Local Binary Pattern (LBP) plus Improved Biomimetic Pattern Recognition (BPR) has been proposed. This system comprises three main steps: real-time color face detection process, feature extraction process and recognition process. Firstly, a color face detector is proposed to detect face with eye alignment and simultaneous performance; while in feature extraction step, LBP method is adopted to eliminate the negative effect of the light heterogeneity. Finally, an improved BPR method with Selective Sampling construction is applied to the recognition system. Experiments on our established database named WYU Database, PUT Database and AR Database show that this real-time face recognition system can work with high efficiency and has achieved comparable performance with the state-of-the-art systems.

  • Static Dependency Pair Method in Rewriting Systems for Functional Programs with Product, Algebraic Data, and ML-Polymorphic Types

    Keiichirou KUSAKARI  

     
    PAPER

      Vol:
    E96-D No:3
      Page(s):
    472-480

    For simply-typed term rewriting systems (STRSs) and higher-order rewrite systems (HRSs) a la Nipkow, we proposed a method for proving termination, namely the static dependency pair method. The method combines the dependency pair method introduced for first-order rewrite systems with the notion of strong computability introduced for typed λ-calculi. This method analyzes a static recursive structure based on definition dependency. By solving suitable constraints generated by the analysis, we can prove termination. In this paper, we extend the method to rewriting systems for functional programs (RFPs) with product, algebraic data, and ML-polymorphic types. Although the type system in STRSs contains only product and simple types and the type system in HRSs contains only simple types, our RFPs allow product types, type constructors (algebraic data types), and type variables (ML-polymorphic types). Hence, our RFPs are more representative of existing functional programs than STRSs and HRSs. Therefore, our result makes a large contribution to applying theoretical rewriting techniques to actual problems, that is, to proving the termination of existing functional programs.

  • Energy- and Traffic-Balance-Aware Mapping Algorithm for Network-on-Chip

    Zhi DENG  Huaxi GU  Yingtang YANG  Hua YOU  

     
    LETTER-Computer System

      Vol:
    E96-D No:3
      Page(s):
    719-722

    In this paper, an energy- and traffic-balance-aware mapping algorithm from IP cores to nodes in a network is proposed for application-specific Network-on-Chip(NoC). The multi-objective optimization model is set up by considering the NoC architecture, and addressed by the proposed mapping algorithm that decomposes mapping optimization into a number of scalar subproblems simultaneously. In order to show performance of the proposed algorithm, the application specific benchmark is applied in the simulation. The experimental results demonstrate that the algorithm has advantages in energy consumption and traffic balance over other algorithms.

  • The Effect of Distinctiveness in Recognizing Average Face: Human Recognition and Eigenface Based Machine Recognition

    Naiwala P. CHANDRASIRI  Ryuta SUZUKI  Nobuyuki WATANABE  Hiroshi YAMADA  

     
    PAPER-Face Perception and Recognition

      Vol:
    E96-D No:3
      Page(s):
    514-522

    Face perception and recognition have attracted more attention recently in multidisciplinary fields such as engineering, psychology, neuroscience, etc. with the advances in physical/physiological measurement and data analysis technologies. In this paper, our main interest is building computational models of human face recognition based on psychological experiments. We specially focus on modeling human face recognition characteristics of average face in the dimension of distinctiveness. Psychological experiments were carried out to measure distinctiveness of face images and their results are explained by computer analysis results of the images. Two psychological experiments, 1) Classical experiment of distinctiveness rating and, 2) Novel experiment of recognition of an average face were performed. In the later experiment, we examined on how the average face of two face images was recognized by a human in a similarity test respect to the original images which were utilized for the calculation of the average face. To explain results of the psychological experiments, eigenface spaces were constructed based on Principal Component Analysis (PCA). Significant correlation was found between human and PCA based computer recognition results. Emulation of human recognition of faces is one of the expected applications of this research.

  • Skyline Monitoring in Wireless Sensor Networks

    Bo YIN  Yaping LIN  Jianping YU  Peng LIU  

     
    PAPER-Network

      Vol:
    E96-B No:3
      Page(s):
    778-789

    In many wireless sensor applications, skyline monitoring queries that continuously retrieve the skyline objects as well as the complete set of nodes that reported them play an important role. This paper presents SKYMON, a novel energy-efficient monitoring approach. The basic idea is to prune nodes that cannot yield a skyline result at the sink, as indicated by their (error bounded) prediction values, to suppress unnecessary sensor updates. Every node is associated with a prediction model, which is maintained at both the node and the sink. Sensors check sensed data against model-predicted values and transmit prediction errors to the sink. A data representation scheme is then developed to calculate an approximate view of each node's reading based on prediction errors and prediction values, which facilitates safe node pruning at the sink. We also develop a piecewise linear prediction model to maximize the benefit of making the predictions. Our proposed approach returns the exact results, while deceasing the number of queried nodes and transferred data. Extensive simulation results show that SKYMON substantially outperforms the existing TAG-based approach and MINMAX approach in terms of energy consumption.

  • Adaptive Iterative Decoding of Finite-Length Differentially Encoded LDPC Coded Systems with Multiple-Symbol Differential Detection

    Yang YU  Shiro HANDA  Fumihito SASAMORI  Osamu TAKYU  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E96-B No:3
      Page(s):
    847-858

    In this paper, through extrinsic information transfer (EXIT) band chart analysis, an adaptive iterative decoding approach (AIDA) is proposed to reduce the iterative decoding complexity and delay for finite-length differentially encoded Low-density parity-check (DE-LDPC) coded systems with multiple-symbol differential detection (MSDD). The proposed AIDA can adaptively adjust the observation window size (OWS) of the MSDD soft-input soft-output demodulator (SISOD) and the outer iteration number of the iterative decoder (consisting of the MSDD SISOD and the LDPC decoder) instead of setting fixed values for the two parameters of the considered systems. The performance of AIDA depends on its stopping criterion (SC) which is used to terminate the iterative decoding before reaching the maximum outer iteration number. Many SCs have been proposed; however, these approaches focus on turbo coded systems, and it has been proven that they do not well suit for LDPC coded systems. To solve this problem, a new SC called differential mutual information (DMI) criterion, which can track the convergence status of the iterative decoding, is proposed; it is based on tracking the difference of the output mutual information of the LDPC decoder between two consecutive outer iterations of the considered systems. AIDA using the DMI criterion can adaptively adjust the out iteration number and OWS according to the convergence situation of the iterative decoding. Simulation results show that compared with using the existing SCs, AIDA using the DMI criterion can further reduce the decoding complexity and delay, and its performance is not affected by a change in the LDPC code and transmission channel parameters.

  • Double-Scale Channel Prediction for Precoded TDD-MIMO Systems

    De-Chun SUN  Zu-Jun LIU  Ke-Chu YI  

     
    LETTER-Mobile Information Network and Personal Communications

      Vol:
    E96-A No:3
      Page(s):
    745-746

    In precoded TDD MIMO systems, precoding is done based on the downlink CSI, which can be predicted according to the outdated uplink CSI. This letter proposes a double-scale channel prediction scheme where frame-scale Kalman filters and pilot-symbol-scale AR predictors jointly predict the needed downlink CSI.

  • High-Tc Superconducting Electronic Devices Based on YBCO Step-Edge Grain Boundary Junctions Open Access

    Shane T. KEENAN  Jia DU  Emma E. MITCHELL  Simon K. H. LAM  John C. MACFARLANE  Chris J. LEWIS  Keith E. LESLIE  Cathy P. FOLEY  

     
    INVITED PAPER

      Vol:
    E96-C No:3
      Page(s):
    298-306

    We outline a number of high temperature superconducting Josephson junction-based devices including superconducting quantum interference devices (SQUIDs) developed for a wide range of applications including geophysical exploration, magnetic anomaly detection, terahertz (THz) imaging and microwave communications. All these devices are based on our patented technology for fabricating YBCO step-edge junction on MgO substrates. A key feature to the successful application of devices based on this technology is good stability, long term reliability, low noise and inherent flexibility of locating junctions anywhere on a substrate.

  • On the Length-Decreasing Self-Reducibility and the Many-One-Like Reducibilities for Partial Multivalued Functions

    Ji-Won HUH  Shuji ISOBE  Eisuke KOIZUMI  Hiroki SHIZUYA  

     
    PAPER

      Vol:
    E96-D No:3
      Page(s):
    465-471

    In this paper, we investigate a relationship between the length-decreasing self-reducibility and the many-one-like reducibilities for partial multivalued functions. We show that if any parsimonious (many-one or metric many-one) complete function for NPMV (or NPMVg) is length-decreasing self-reducible, then any function in NPMV (or NPMVg) has a polynomial-time computable refinement. This result implies that there exists an NPMV (or NPMVg)-complete function which is not length-decreasing self-reducible unless P = NP.

  • Winning the Kaggle Algorithmic Trading Challenge with the Composition of Many Models and Feature Engineering

    Ildefons MAGRANS DE ABRIL  Masashi SUGIYAMA  

     
    LETTER-Artificial Intelligence, Data Mining

      Vol:
    E96-D No:3
      Page(s):
    742-745

    This letter presents the ideas and methods of the winning solution* for the Kaggle Algorithmic Trading Challenge. This analysis challenge took place between 11th November 2011 and 8th January 2012, and 264 competitors submitted solutions. The objective of this competition was to develop empirical predictive models to explain stock market prices following a liquidity shock. The winning system builds upon the optimal composition of several models and a feature extraction and selection strategy. We used Random Forest as a modeling technique to train all sub-models as a function of an optimal feature set. The modeling approach can cope with highly complex data having low Maximal Information Coefficients between the dependent variable and the feature set and provides a feature ranking metric which we used in our feature selection algorithm.

  • Improving User's Privacy for Multi-Authority ABE Using Privacy Homomorphism

    Ang GAO  Zeng-Zhi LI  

     
    LETTER-Cryptography and Information Security

      Vol:
    E96-A No:3
      Page(s):
    724-727

    In order to improve user's privacy in multi-authority Attribute-Based Encryption (ABE), we propose a solution which hides user's attributes by privacy homomorphism, such that not only the “external” adversary fails to access the private attribute of one user by eavesdropping on communications, but also the “internal” Attribute Authorities (AA), who are responsible for issuing attribute keys, are unable to build a full profile with all of the user's attributes by pooling their information on the user's ID. Meanwhile, the use of ID is essential to defend against collusion attack on ABE. Benefiting from privacy homomorphism, by which we distribute the part of the interpolation for the shares abstracted by the hidden attributes into each AA, the performance of the proposed scheme is higher than those of existing ABE schemes.

2661-2680hit(8214hit)