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[Keyword] CTI(8214hit)

4081-4100hit(8214hit)

  • Multiple View Geometry under Projective Projection in Space-Time

    Cheng WAN  Jun SATO  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E91-D No:9
      Page(s):
    2353-2359

    This paper introduces multiple view geometry under projective projection from four-dimensional space to two-dimensional space which can represent multiple view geometry under the projection of space-time. We show the multifocal tensors defined under space-time projective projection can be derived from non-rigid object motions viewed from multiple cameras with arbitrary translational motions, and they are practical for generating images of non-rigid object motions viewed from cameras with arbitrary translational motions. The method is tested in real image sequences.

  • A New Model for the Error Detection Delay of Finite Precision Binary Arithmetic Codes with a Forbidden Symbol

    Yuye PANG  Jun SUN  Jia WANG  Peng WANG  

     
    LETTER-Fundamental Theories for Communications

      Vol:
    E91-B No:9
      Page(s):
    2987-2990

    In this paper, the statistical characteristic of the Error Detection Delay (EDD) of Finite Precision Binary Arithmetic Codes (FPBAC) is discussed. It is observed that, apart from the probability of the Forbidden Symbol (FS) inserted into the list of the source symbols, the probability of the source sequence and the operation precision as well as the position of the FS in the coding interval can affect the statistical characteristic of the EDD. Experiments demonstrate that the actual distribution of the EDD of FPBAC is quite different from the geometric distribution of infinite precision arithmetic codes. This phenomenon is researched deeply, and a new statistical model (gamma distribution) of the actual distribution of the EDD is proposed, which can make a more precise prediction of the EDD. Finally, the relation expressions between the parameters of gamma distribution and the related factors affecting the distribution are given.

  • Pulse Wave Propagation in a Large Number of Coupled Bistable Oscillators

    Kuniyasu SHIMIZU  Tetsuro ENDO  Daishin UEYAMA  

     
    LETTER

      Vol:
    E91-A No:9
      Page(s):
    2540-2545

    A simple model of inductor-coupled bistable oscillators is shown to exhibit pulse wave propagation. We demonstrate numerically that there exists a pulse wave which propagates with a constant speed in comparatively wide parameter region. In particular, the propagating pulse wave can be observed in non-uniform lattice with noise. The propagating pulse wave can be observed for comparatively strong coupling case, and for weak coupling case no propagating pulse wave can be observed (propagation failure). We also demonstrate various interaction phenomena between two pulses.

  • A Theoretical Analysis of On-Line Learning Using Correlated Examples

    Chihiro SEKI  Shingo SAKURAI  Masafumi MATSUNO  Seiji MIYOSHI  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E91-A No:9
      Page(s):
    2663-2670

    In this paper we analytically investigate the generalization performance of learning using correlated inputs in the framework of on-line learning with a statistical mechanical method. We consider a model composed of linear perceptrons with Gaussian noise. First, we analyze the case of the gradient method. We analytically clarify that the larger the correlation among inputs is or the larger the number of inputs is, the stricter the condition the learning rate should satisfy is, and the slower the learning speed is. Second, we treat the block orthogonal projection learning as an alternative learning rule and derive the theory. In a noiseless case, the learning speed does not depend on the correlation and is proportional to the number of inputs used in an update. The learning speed is identical to that of the gradient method with uncorrelated inputs. On the other hand, when there is noise, the larger the correlation among inputs is, the slower the learning speed is and the larger the residual generalization error is.

  • Ultra Dependable Processor

    Shuichi SAKAI  Masahiro GOSHIMA  Hidetsugu IRIE  

     
    INVITED PAPER

      Vol:
    E91-C No:9
      Page(s):
    1386-1393

    This paper presents the processor architecture which provides much higher level dependability than the current ones. The features of it are: (1) fault tolerance and secure processing are integrated into a modern superscalar VLSI processor; (2) light-weight effective soft-error tolerant mechanisms are proposed and evaluated; (3) timing errors on random logic and registers are prevented by low-overhead mechanisms; (4) program behavior is hidden from the outer world by proposed address translation methods; (5) information leakage can be avoided by attaching policy tags for all data and monitoring them for each instruction execution; (6) injection attacks are avoided with much higher accuracy than the current systems, by providing tag trackings; (7) the overall structure of the dependable processor is proposed with a dependability manager which controls the detection of illegal conditions and recovers to the normal mode; and (8) an FPGA-based testbed system is developed where the system clock and the voltage are intentionally varied for experiment. The paper presents the fundamental scheme for the dependability, elemental technologies for dependability and the whole architecture of the ultra dependable processor. After showing them, the paper concludes with future works.

  • Replicator Dynamics with Dynamic Payoff Reallocation Based on the Government's Payoff

    Takafumi KANAZAWA  Hayato GOTO  Toshimitsu USHIO  

     
    PAPER-Nonlinear System Theory

      Vol:
    E91-A No:9
      Page(s):
    2411-2418

    In a population which consists of a large number of players interacting with each other, the payoff of each player often conflicts with the total payoff of the population which he/she belongs to. In such a situation, a "government" which has the comprehensive perspective is needed to govern the population. Recently, to discuss the population with the government, the authors have proposed replicator dynamics with reallocation of payoffs to analyze an effect of the government. In this model, the government is willing to lead the population to a desirable target state by collecting a part of players' payoffs and reallocating them depending on the target state. The government's action is the rate of collecting payoffs from players and the rate is assumed to be constant and independent of the population state. Thus, in this paper, we suppose that the government change their intervention strategy depending on the current population state. We consider the government as a game player and define the government's payoff as a sum of a benefit and a cost of intervention. We propose a model which describes the evolution of the government's reallocation strategy and investigate stability of its equilibrium points.

  • Secure Multiparty Computation for Comparator Networks

    Gembu MOROHASHI  Koji CHIDA  Keiichi HIROTA  Hiroaki KIKUCHI  

     
    PAPER

      Vol:
    E91-A No:9
      Page(s):
    2349-2355

    We propose a multiparty protocol for comparator networks which are used to compute various functions in statistical analysis, such as the maximum, minimum, median, and quartiles, for example, through sorting and searching. In the protocol, all values which are inputted to a comparator network and all intermediate outputs are kept secret assuming the presence of an honest majority. We also introduce an application of the protocol for a secure (M+1)-st price auction.

  • Detecting Theft of Java Applications via a Static Birthmark Based on Weighted Stack Patterns

    Hyun-il LIM  Heewan PARK  Seokwoo CHOI  Taisook HAN  

     
    PAPER-Application Information Security

      Vol:
    E91-D No:9
      Page(s):
    2323-2332

    A software birthmark means the inherent characteristics of a program that can be used to identify the program. A comparison of such birthmarks facilitates the detection of software theft. In this paper, we propose a static Java birthmark based on a set of stack patterns, which reflect the characteristic of Java applications. A stack pattern denotes a sequence of bytecodes that share their operands through the operand stack. A weight scheme is used to balance the influence of each bytecode in a comparison of the birthmarks. We evaluate the proposed birthmark with respect to two properties required for a birthmark: credibility and resilience. The empirical results show that the proposed birthmark is highly credible and resilient to program transformation. We also compare the proposed birthmark with existing birthmarks, such as that of Tamada et al. and the k-gram birthmark. The experimental results show that the proposed birthmark is more stable than the birthmarks in terms of resilience to program transformation. Thus, the proposed birthmark can provide more reliable evidence of software theft when the software is modified by someone other than author.

  • Near-Field to Far-Field Transformation for an Outdoor RCS Range

    Yoshio INASAWA  Shinji KURODA  Ken-ichi KAKIZAKI  Hitoshi NISHIKAWA  Naofumi YONEDA  Shigeru MAKINO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E91-C No:9
      Page(s):
    1463-1471

    This paper presents the near-field to far-field transformation for an outdoor radar cross section (RCS) range. Direct measurement of the large actual target requires quite a long measurement range. The near-field to far-field RCS transformation method achieves the reduction of measurement range. However the non-uniformity of the incident electric field distribution on the target causes some errors in RCS prediction. We propose a novel near-field to far-field RCS transformation method that can be applied to an outdoor RCS measurement. The non-uniformity of the incident electric field distribution is successfully resolved by introducing the correction term of the ground bounce. We investigate the validity of the proposed method by the simulation and measurement.

  • Derivation of Excess Mean-Square Error for Affine Projection Algorithms Using the Condition Number

    Chang Woo LEE  Hyeonwoo CHO  Sang Woo KIM  

     
    LETTER-Digital Signal Processing

      Vol:
    E91-A No:9
      Page(s):
    2675-2677

    This letter presents a new mathematical expression for the excess mean-square error (EMSE) of the affine projection (AP) algorithm. The proposed expression explicitly shows the proportional relationship between the EMSE and the condition number of the input signals.

  • Adaptive Flocking of Robot Swarms: Algorithms and Properties

    Geunho LEE  Nak Young CHONG  

     
    PAPER-Theories

      Vol:
    E91-B No:9
      Page(s):
    2848-2855

    This paper presents a distributed approach for adaptive flocking of swarms of mobile robots that enables to navigate autonomously in complex environments populated with obstacles. Based on the observation of the swimming behavior of a school of fish, we propose an integrated algorithm that allows a swarm of robots to navigate in a coordinated manner, split into multiple swarms, or merge with other swarms according to the environment conditions. We prove the convergence of the proposed algorithm using Lyapunov stability theory. We also verify the effectiveness of the algorithm through extensive simulations, where a swarm of robots repeats the process of splitting and merging while passing around multiple stationary and moving obstacles. The simulation results show that the proposed algorithm is scalable, and robust to variations in the sensing capability of individual robots.

  • A Single Backup-Table Rerouting Scheme for Fast Failure Protection in OSPF

    Takuya YOSHIHIRO  

     
    PAPER-Theories

      Vol:
    E91-B No:9
      Page(s):
    2838-2847

    We propose a practical link protection scheme, called Single Backup-table Rerouting, (SBR) as an extension for Open Shortest Path First (OSPF). SBR protects against any single link failure as soon as the failure occurs if the topology of every area in OSPF is two-link-connected. An efficient algorithm to compute a set of backup tables is provided for networks with symmetric link costs. The foremost feature of SBR is that the backup process is fully distributed, so no message exchange is required and the modification of OSPF is minor. OSPF is extended with the following: only one extra backup routing table, a 2-bit flag at each traffic packet, and a process for handling the backup table. There are no changes to the message format of OSPF. In this paper, we present the practical link protection scheme by fitting SBR into several OSPF specific mechanisms such as OSPF areas, Equal Costs Multipath (ECMP), and virtual links with proofs of their correctness. Furthermore, together with a loop-free routing technique for link-state routing, SBR guarantees the consistency of every route against a single link failure, even during the path recomputation phase, until it converges to the new shortest paths.

  • A Simple Mechanism for Collapsing Instructions under Timing Speculation

    Toshinori SATO  

     
    PAPER

      Vol:
    E91-C No:9
      Page(s):
    1394-1401

    The deep submicron semiconductor technologies will make the worst-case design impossible, since they can not provide design margins that it requires. We are investigating a typical-case design methodology, which we call the Constructive Timing Violation (CTV). This paper extends the CTV concept to collapse dependent instructions, resulting in performance improvement. Based on detailed simulations, we find the proposed mechanism effectively collapses dependent instructions.

  • Single-Input Six-Output Voltage-Mode Filter Using Universal Voltage Conveyors

    Martin MINARCIK  Kamil VRBA  

     
    LETTER

      Vol:
    E91-A No:8
      Page(s):
    2035-2037

    In this letter a new structure of multifunctional frequency filter using a universal voltage conveyor (UVC) is presented. The multifunctional circuit can realize a low-pass, high-pass and band-pass filter. All types of frequency filter can be realized as inverting or non-inverting. Advantages of the proposed structure are the independent control of the quality factor at the cut-off frequency and the low output impedance of output terminals. The computer simulations and measuring of particular frequency filters are depicted.

  • An Efficient Reversible Image Authentication Method

    Seungwu HAN  Masaaki FUJIYOSHI  Hitoshi KIYA  

     
    PAPER

      Vol:
    E91-A No:8
      Page(s):
    1907-1914

    This paper proposes an image authentication method that detects tamper and localizes tampered areas efficiently. The efficiency of the proposed method is summarized as the following three points. 1) This method offers coarse-to-fine tamper localization by hierarchical data hiding so that further tamper detection is suppressed for blocks labeled as genuine in the uppper layer. 2) Since the image feature description in the top layer is hidden over an image, the proposed method enciphers the data in the top layer rather than enciphers all data in all layers. 3) The proposed method is based on the reversible data hiding scheme that does not use highly-costed compression technique. These three points makes the proposed method superior to the conventional methods using compression techniques and methods using multi-tiered data hiding that requires integrity verification in many blocks even the image is genuine. Simulation results show the effectiveness of the proposed method.

  • Quadrature Hartley VCO and Injection-Locked Frequency Divider

    Sheng-Lyang JANG  Chia-Wei CHANG  Sheng-Chien WU  Chien-Feng LEE  Lin-yen TSAI  Jhin-Fang HUANG  

     
    LETTER-Electronic Circuits

      Vol:
    E91-C No:8
      Page(s):
    1371-1374

    Novel low phase noise quadrature voltage-controlled oscillator (QVCO) and quadrature injection locked frequency divider (QILFD) with two coupled Hartley VCOs are proposed and implemented using the standard TSMC 0.18 µm CMOS 1P6M process. The QVCO employs pMOS as the core to reduce the up-conversion of low-frequency device noise to RF phase noise. It uses super-harmonic coupling technique to couple two differential Hartley VCOs and four small-size coupling transistors to set the directivity of quadrature output phases. At the 1.7 V supply voltage, the output phase noise of the QVCO is -124 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 4.12 GHz, and the figure of merit is -185 dBc/Hz. At the supply voltage of 1.7 V, the total power consumption is 13.1 mW. At the supply voltage of 1.5 V, the tuning range of the free-running QILFD is from 2.05 GHz to 2.36 GHz, about 310 MHz, and the locking range of the ILFD is from 3.99 to 5.19 GHz, about 1.20 GHz, at the injection signal power of 0 dBm.

  • High Resolution DOA Estimation Using Unwrapped Phase Information of MUSIC-Based Noise Subspace

    Koichi ICHIGE  Kazuhiko SAITO  Hiroyuki ARAI  

     
    PAPER

      Vol:
    E91-A No:8
      Page(s):
    1990-1999

    This paper presents a high resolution Direction-Of-Arrival (DOA) estimation method using unwrapped phase information of MUSIC-based noise subspace. Superresolution DOA estimation methods such as MUSIC, Root-MUSIC and ESPRIT methods are paid great attention because of their brilliant properties in estimating DOAs of incident signals. Those methods achieve high accuracy in estimating DOAs in a good propagation environment, but would fail to estimate DOAs in severe environments like low Signal-to-Noise Ratio (SNR), small number of snapshots, or when incident waves are coming from close angles. In MUSIC method, its spectrum is calculated based on the absolute value of the inner product between array response and noise eigenvectors, means that MUSIC employs only the amplitude characteristics and does not use any phase characteristics. Recalling that phase characteristics plays an important role in signal and image processing, we expect that DOA estimation accuracy could be further improved using phase information in addition to MUSIC spectrum. This paper develops a procedure to obtain an accurate spectrum for DOA estimation using unwrapped and differentiated phase information of MUSIC-based noise subspace. Performance of the proposed method is evaluated through computer simulation in comparison with some conventional estimation methods.

  • Locally Adaptive Perceptual Compression for Color Images

    Kuo-Cheng LIU  Chun-Hsien CHOU  

     
    PAPER-Image

      Vol:
    E91-A No:8
      Page(s):
    2213-2222

    The main idea in perceptual image compression is to remove the perceptual redundancy for representing images at the lowest possible bit rate without introducing perceivable distortion. A certain amount of perceptual redundancy is inherent in the color image since human eyes are not perfect sensors for discriminating small differences in color signals. Effectively exploiting the perceptual redundancy will help to improve the coding efficiency of compressing color images. In this paper, a locally adaptive perceptual compression scheme for color images is proposed. The scheme is based on the design of an adaptive quantizer for compressing color images with the nearly lossless visual quality at a low bit rate. An effective way to achieve the nearly lossless visual quality is to shape the quantization error as a part of perceptual redundancy while compressing color images. This method is to control the adaptive quantization stage by the perceptual redundancy of the color image. In this paper, the perceptual redundancy in the form of the noise detection threshold associated with each coefficient in each subband of three color components of the color image is derived based on the finding of perceptually indistinguishable regions of color stimuli in the uniform color space and various masking effects of human visual perception. The quantizer step size for the target coefficient in each color component is adaptively adjusted by the associated noise detection threshold to make sure that the resulting quantization error is not perceivable. Simulation results show that the compression performance of the proposed scheme using the adaptively coefficient-wise quantization is better than that using the band-wise quantization. The nearly lossless visual quality of the reconstructed image can be achieved by the proposed scheme at lower entropy.

  • Novel Conventional Standard Linear Element Based Complete Passive Equivalent Circuit Models of the Practical OTA-Based Inductors

    Rawid BANCHUIN  Boonruk CHIPIPOP  Boonchareon SIRINAOVAKUL  

     
    PAPER

      Vol:
    E91-A No:8
      Page(s):
    1883-1889

    In this research, the practical OTA-based inductors of all structures have been studied and their complete passive equivalent circuit models, where the effects of both parasitic elements and finite opened-loop bandwidth have been taken into account, also contain only the conventional standard linear elements i.e. the ordinary resistor, inductor and capacitor, without any infeasible high order element e.g. super inductor etc., have been proposed. The resulting models have been found to be excellently accurate, excellently straight forward, far superior to the previously proposed ones and completely realizable by the passive elements. Hence, the proposed passive equivalent circuit models have been found to be the convenience and versatile tools for the implementation of any analog and mixed signal processing circuits and systems.

  • A Deep Monotone Approximation Operator Based on the Best Quadratic Lower Bound of Convex Functions

    Masao YAMAGISHI  Isao YAMADA  

     
    PAPER

      Vol:
    E91-A No:8
      Page(s):
    1858-1866

    This paper presents a closed form solution to a problem of constructing the best lower bound of a convex function under certain conditions. The function is assumed (I) bounded below by -ρ, and (II) differentiable and its derivative is Lipschitz continuous with Lipschitz constant L. To construct the lower bound, it is also assumed that we can use the values ρ and L together with the values of the function and its derivative at one specified point. By using the proposed lower bound, we derive a computationally efficient deep monotone approximation operator to the level set of the function. This operator realizes better approximation than subgradient projection which has been utilized, as a monotone approximation operator to level sets of differentiable convex functions as well as nonsmooth convex functions. Therefore, by using the proposed operator, we can improve many signal processing algorithms essentially based on the subgradient projection.

4081-4100hit(8214hit)