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[Keyword] Continua(9hit)

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  • Predicting Uninterruptible Durations of Office Workers by Using Probabilistic Work Continuance Model

    Shota SHIRATORI  Yuichiro FUJIMOTO  Kinya FUJITA  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2020/01/10
      Vol:
    E103-D No:4
      Page(s):
    838-849

    In order not to disrupt a team member concentrating on his/her own task, the interrupter needs to wait for a proper time. In this research, we examined the feasibility of predicting prospective interruptible times of office workers who use PCs. An analysis of actual working data collected from 13 participants revealed the relationship between uninterruptible durations and four features, i.e. type of application software, rate of PC operation activity, activity ratio between keystrokes and mouse clicks, and switching frequency of application software. On the basis of these results, we developed a probabilistic work continuance model whose probability changes according to the four features. The leave-one-out cross-validation indicated positive correlations between the actual and the predicted durations. The medians of the actual and the predicted durations were 539 s and 519 s. The main contribution of this study is the demonstration of the feasibility to predict uninterruptible durations in an actual working scenario.

  • Generic Transformation for Signatures in the Continual Leakage Model

    Yuyu WANG  Keisuke TANAKA  

     
    PAPER

      Vol:
    E100-A No:9
      Page(s):
    1857-1869

    In ProvSec 2014, Wang and Tanaka proposed a transformation which converts weakly existentially unforgeable (wEUF) signature schemes into strongly existentially unforgeable (sEUF) ones in the bounded leakage model. To obtain the construction, they combined leakage resilient (LR) chameleon hash functions with the Generalised Boneh-Shen-Waters (GBSW) transformation proposed by Steinfeld, Pieprzyk, and Wang. However, their transformation cannot be used in a more realistic model called continual leakage model since secret keys of LR chameleon hash functions cannot be updated. In this paper, we propose a transformation which can convert wEUF signature schemes into sEUF ones in the continual leakage model. To achieve our goal, we give a new definition of continuous leakage resilient (CLR) chameleon hash function and construct it based on the CLR signature scheme proposed by Malkin, Teranishi, Vahlis, and Yung. Although our CLR chameleon hash functions satisfy the property of strong collision-resistance, due to the existence of the updating algorithm, an adversary may find the kind of collisions such that messages are the same but randomizers are different. Hence, we cannot combine our chameleon hash functions with the GBSW transformation directly, or the sEUF security of the transformed signature schemes cannot be achieved. To solve this problem, we improve the original GBSW transformation by making use of the Groth-Sahai proof system and then combine it with CLR chameleon hash functions.

  • The Current State of Digital Healthcare towards Medical Application Open Access

    Toru WATSUJI  

     
    INVITED PAPER

      Vol:
    E99-B No:3
      Page(s):
    565-568

    Infrastructures for the evaluation of the state of health of individuals using a standardized communication network consisting of advanced instruments and subsequent data analysis have been developed. Here we report that this developed infrastructure has been tested in the field in 100 houses and involving almost 300 users. The communication protocol part of this infrastructure has been standardized as IEEE 11073-20601. Continua Health Alliance, an international not-for-profit industry organization which has nearly 230 member companies, has adopted this IEEE 11073-20601 to establish an ecosystem of interoperable personal connected health systems that empower individuals and organizations to better manage their health and wellness. Currently nearly 100 Continua certified products are available in public including smartphone.

  • Some Remarks on the Extension of Numerical Data to the Complex Space for Radiation Patterns in Electromagnetic Scattering Problems

    Masahiro HASHIMOTO  

     
    LETTER

      Vol:
    E92-C No:1
      Page(s):
    109-111

    A numerical scheme for the analytic continuation of radiation patterns of the azimuthal coordinate θ into the whole space over the complex plane is given. The scattering data given over the real space [0, 2π] are extended into the complex plane by using the recurrence formulas. An example shows the validity of mathematically exact evaluation for the scattering from polygonal cylinders.

  • A Simple Joint Estimation Method of Residual Frequency Offset and Sampling Frequency Offset for DVB Systems

    Ki-Won KWON  Yongsoo CHO  

     
    LETTER-Broadcast Systems

      Vol:
    E91-B No:5
      Page(s):
    1673-1676

    This letter presents a simple joint estimation method for residual frequency offset (RFO) and sampling frequency offset (STO) in OFDM-based digital video broadcasting (DVB) systems. The proposed method selects a continual pilot (CP) subset from an unsymmetrically and non-uniformly distributed CP set to obtain an unbiased estimator. Simulation results show that the proposed method using a properly selected CP subset is unbiased and performs robustly.

  • On Computing Connecting Orbits: General Algorithm and Applications to the Sine–Gordon and Hodgkin–Huxley Equations

    Eusebius J. DOEDEL  Mark J. FRIEDMAN  John GUCKENHEIMER  

     
    PAPER-Chaos and Related Topics

      Vol:
    E77-A No:11
      Page(s):
    1801-1805

    A systematic method for locating and computing branches of connecting orbits developed by the authors is outlined. The method is applied to the sine–Gordon and Hodgkin–Huxley equations.

  • A Correcting Method for Pitch Extraction Using Neural Networks

    Akio OGIHARA  Kunio FUKUNAGA  

     
    PAPER-Neural Networks

      Vol:
    E77-A No:6
      Page(s):
    1015-1022

    Pitch frequency is a basic characteristic of human voice, and pitch extraction is one of the most important studies for speech recognition. This paper describes a simple but effective technique to obtain correct pitch frequency from candidates (pitch candidates) extracted by the short-range autocorrelation function. The correction is performed by a neural network in consideration of the time coutinuation that is realized by referring to pitch candidates at previous frames. Since the neural network is trained by the back-propagation algorithm with training data, it adapts to any speaker and obtains good correction without sensitive adjustment and tuning. The pitch extraction was performed for 3 male and 3 female announcers, and the proposed method improves the percentage of correct pitch from 58.65% to 89.19%.

  • Computation of Constrained Channel Capacity by Newton's Method

    Kiyotaka YAMAMURA  Shin'ichi OISHI  Kazuo HORIUCHI  

     
    LETTER-Numerical Analysis and Self-Validation

      Vol:
    E76-A No:6
      Page(s):
    1043-1048

    Algorithms for computing channel capacity have been proposed by many researchers. Recently, one of the authors proposed an efficient algorithm using Newton's method. Since this algorithm has local quadratic convergence, it is advantageous when we want to obtain a numerical solution with high accuracy. In this letter, it is shown that this algorithm can be extended to the algorithm for computing the constrained capacity, i.e., the capacity of discrete memoryless channels with linear constraints. The global convergence of the extended algorithm is proved, and its effectiveness is verified by numerical examples.

  • A Newton Algorithm for Computing the Capacity of Discrete Memoryless Channels

    Kiyotaka YAMAMURA  

     
    PAPER-Numerical Analysis and Self-Validation

      Vol:
    E75-A No:11
      Page(s):
    1583-1589

    This paper presents an efficient algorithm for computing the capacity of discrete memoryless channels. The algorithm uses Newton's method which is known to be quadratically convergent. First, a system of nonlinear equations termed Kuhn-Tucker equations is formulated, which has the capacity as a solution. Then Newton's method is applied to the Kuhn-Tucker equations. Since Newton's method does not guarantee global convergence, a continuation method is also introduced. It is shown that the continuation method works well and the convergence of the Newton algorithm is guaranteed. By numerical examples, effectiveness of the algorithm is verified. Since the proposed algorithm has local quadratic convergence, it is advantageous when we want to obtain a numerical solution with high accuracy.