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7961-7980hit(20498hit)

  • A Hardware-Efficient Pattern Matching Architecture Using Process Element Tree for Deep Packet Inspection

    Seongyong AHN  Hyejeong HONG  HyunJin KIM  Jin-Ho AHN  Dongmyong BAEK  Sungho KANG  

     
    LETTER-Network Management/Operation

      Vol:
    E93-B No:9
      Page(s):
    2440-2442

    This paper proposes a new pattern matching architecture with multi-character processing for deep packet inspection. The proposed pattern matching architecture detects the start point of pattern matching from multi-character input using input text alignment. By eliminating duplicate hardware components using process element tree, hardware cost is greatly reduced in the proposed pattern matching architecture.

  • Effect of Holder Heat Capacity on Bridge Shape at Low Speed Breaking Contact

    Kazuaki MIYANAGA  Yoshiki KAYANO  Tasuku TAKAGI  Hiroshi INOUE  

     
    BRIEF PAPER

      Vol:
    E93-C No:9
      Page(s):
    1456-1459

    In order to clarify the physics of contact life time, the relationship between heat capacity of holder and shape of bridge (length and diameter) is discussed in this paper. The AgPd60 alloy is chosen as electrode material. Two holders with different heat capacity are comprised of copper plate and cylinder. The shape of the bridge at the low speed breaking contact is observed by using the high speed digital camera. It was demonstrated that the shape of the bridge is changed by the response and distribution of the temperature.

  • Development of Efficient Discrete Model and Error Analysis for Nonlinear RF Power Amplifiers in Wireless Communications

    Hyunchul KU  Youngcheol PARK  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E93-B No:9
      Page(s):
    2363-2369

    This paper discusses an efficient discrete model for nonlinear RF power amplifier (PA) with long-term memory effects and analyzes its error. The procedure of converting RF signals and systems into a discrete domain is explained for a discrete baseband memory polynomial model. Unlike a previous simple memory polynomial model, the proposed discrete model has two different sampling frequencies: one for nonlinear system with long-term memory effects and one for input signal. A method to choose an optimal sampling frequency for the system and a discrete memory depth is proposed to minimize the sensitivity of the system for perturbation of the measured data. A two-dimensional sensitivity function which is a product of relative residual and matrix condition number is defined for least square problem of the proposed model. Examples with a wideband WiBro 3FA signal and a WCDMA 4FA signal for nonlinear transmitters are presented to describe the overall procedure and effectiveness of the proposed scheme.

  • Commercial Shot Classification Based on Multiple Features Combination

    Nan LIU  Yao ZHAO  Zhenfeng ZHU  Rongrong NI  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E93-D No:9
      Page(s):
    2651-2655

    This paper presents a commercial shot classification scheme combining well-designed visual and textual features to automatically detect TV commercials. To identify the inherent difference between commercials and general programs, a special mid-level textual descriptor is proposed, aiming to capture the spatio-temporal properties of the video texts typical of commercials. In addition, we introduce an ensemble-learning based combination method, named Co-AdaBoost, to interactively exploit the intrinsic relations between the visual and textual features employed.

  • User Location in Picocells -- A Paging Algorithm Derived from Measured Data

    Stephan WANKE  Hiroshi SAITO  Yutaka ARAKAWA  Shinsuke SHIMOGAWA  

     
    PAPER-Network

      Vol:
    E93-B No:9
      Page(s):
    2291-2298

    We present a new paging algorithm for wireless networks with ultra-short-range radio access links (picocells). The ubiquitous office (u-office) network is a good example of such a network, and we present some u-office example applications. In addition, we show that conventional paging algorithms are not feasible in such networks. Therefore, we derived a new paging algorithm from the measurement results of an experimental sensor network with short-range wireless links deployed in our office. We equipped persons with sensors and deployed sensor readers at selected places in our office. The sensors transmit messages to the sensor readers at regular intervals. If no sensor reader is in range, the message is lost. Our main observation is that, if a picocell shows an attraction property to a certain person, the residence time of an attached mobile terminal is not gamma distributed (as described in the literature) and the probability of long-lasting residences increases. Thus, if the residence time is larger than a certain threshold, the probability of a long-lasting residence time increases if a sensor reader location has an attraction property to a person. Based on this observation, our proposed paging algorithm registers the location of the mobile terminal only when the residence time in the cell is longer than a predetermined constant. By appropriately setting this constant, we can significantly reduce the registration message frequency while ensuring that the probability of the network successfully connecting to a mobile terminal remains high.

  • Strongly Secure Privacy Amplification Cannot Be Obtained by Encoder of Slepian-Wolf Code

    Shun WATANABE  Ryutaroh MATSUMOTO  Tomohiko UYEMATSU  

     
    PAPER-Information Theory

      Vol:
    E93-A No:9
      Page(s):
    1650-1659

    Privacy amplification is a technique to distill a secret key from a random variable by a function so that the distilled key and eavesdropper's random variable are statistically independent. There are three kinds of security criteria for the key distilled by privacy amplification: the normalized divergence criterion, which is also known as the weak security criterion, the variational distance criterion, and the divergence criterion, which is also known as the strong security criterion. As a technique to distill a secret key, it is known that the encoder of a Slepian-Wolf (the source coding with full side-information at the decoder) code can be used as a function for privacy amplification if we employ the weak security criterion. In this paper, we show that the encoder of a Slepian-Wolf code cannot be used as a function for privacy amplification if we employ the criteria other than the weak one.

  • Opening Electrical Contacts: The Transition from the Molten Metal Bridge to the Electric Arc Open Access

    Paul G. SLADE  

     
    INVITED PAPER

      Vol:
    E93-C No:9
      Page(s):
    1380-1386

    This paper presents a comprehensive explanation of the formation of the electric arc between opening contacts in a current carrying electric circuit. As the contacts begin to open a molten metal bridge forms between them. The rupture of this bridge and the initial formation of the electric arc are studied in both atmospheric air and vacuum using experiments to determine the direction of metal transfer between the contacts as a function of time after the rupture of the molten metal bridge. High speed streak photography is also used to show the rupture of the molten metal bridge and the initial formation of the electric arc. Analysis of these data show that a very high-pressure, high-temperature metal vapor zone exists between the contacts after the rupture of the molten metal bridge. Under this condition a pseudo-arc forms where current is carried by metal ions and an anomalous, high net transfer of metal to the cathodic contact occurs. The pressure in this region decreases rapidly and there is a transition to the usual electric arc, which still operates in the metal vapor. In this arc the current is now mostly carried by electrons. The data shows that there is still a net transfer of metal to the cathode, but now its volume is a function of the arcing time.

  • Thermal Simulation of a Contactor with Feedback Controlled Magnet System

    Liang JI  Degui CHEN  Yingyi LIU  Xingwen LI  

     
    PAPER

      Vol:
    E93-C No:9
      Page(s):
    1424-1430

    Similarities and differences of the thermal analysis issues between the intelligent and general AC contactors are analyzed. Heat source model of the magnet system is established according to the unique control mode of the intelligent AC contactor. Linking with the features common of the two kinds of contactors, the extension of the thermal analysis method of the general AC contactor to the intelligent AC contactor is demonstrated. Consequently, a comprehensive thermal analysis model considering heat sources of both main circuit and magnet system is constructed for the intelligent AC contactor. With this model, the steady-state temperature rise of the intelligent AC contactor is calculated and compared with the measurements of an actual intelligent AC contactor.

  • Linear Analysis of Feedforward Ring Oscillators

    Young-Seok PARK  Pyung-Su HAN  Woo-Young CHOI  

     
    BRIEF PAPER-Electronic Circuits

      Vol:
    E93-C No:9
      Page(s):
    1467-1470

    A linear model for feedforward ring oscillators (FROs) is developed and oscillator characteristics are analyzed using the model. The model allows prediction of multiple oscillation modes as well as the oscillation frequency of each mode. The prediction agrees well with SPICE simulation results.

  • Structural Models that Manage IT Portfolio Affecting Business Value of Enterprise Architecture

    Takaaki KAMOGAWA  

     
    PAPER-Office Information Systems, e-Business Modeling

      Vol:
    E93-D No:9
      Page(s):
    2566-2576

    This paper examines the structural relationships between Information Technology (IT) governance and Enterprise Architecture (EA), with the objective of enhancing business value in the enterprise society. Structural models consisting of four related hypotheses reveal the relationship between IT governance and EA in the improvement of business values. We statistically examined the hypotheses by analyzing validated questionnaire items from respondents within firms listed on the Japanese stock exchange who were qualified to answer them. We concluded that firms which have organizational ability controlled by IT governance are more likely to deliver business value based on IT portfolio management.

  • Esophageal Speech Enhancement Based on Statistical Voice Conversion with Gaussian Mixture Models

    Hironori DOI  Keigo NAKAMURA  Tomoki TODA  Hiroshi SARUWATARI  Kiyohiro SHIKANO  

     
    PAPER-Voice Conversion

      Vol:
    E93-D No:9
      Page(s):
    2472-2482

    This paper presents a novel method of enhancing esophageal speech using statistical voice conversion. Esophageal speech is one of the alternative speaking methods for laryngectomees. Although it doesn't require any external devices, generated voices usually sound unnatural compared with normal speech. To improve the intelligibility and naturalness of esophageal speech, we propose a voice conversion method from esophageal speech into normal speech. A spectral parameter and excitation parameters of target normal speech are separately estimated from a spectral parameter of the esophageal speech based on Gaussian mixture models. The experimental results demonstrate that the proposed method yields significant improvements in intelligibility and naturalness. We also apply one-to-many eigenvoice conversion to esophageal speech enhancement to make it possible to flexibly control the voice quality of enhanced speech.

  • A Novel Communication Range Recognition (CRR) Scheme for Spatial Localization of Passive RFID Tags

    Tomotaka WADA  Norie UCHITOMI  Yuuki OTA  Toshihiro HORI  Kouichi MUTSUURA  Hiromi OKADA  

     
    PAPER-Mobile Information Network and Personal Communications

      Vol:
    E93-A No:9
      Page(s):
    1660-1669

    RFID (Radio Frequency Identification) technology is expected to be used as a localization tool. By the localization of RFID tags, a mobile robot equipped with an RFID reader can recognize the surrounding environment. In this paper, we propose a novel effective scheme called the communication range recognition (CRR) scheme for localizing RFID tags. In this scheme, an RFID reader determines the boundaries of the communication range when it is appropriately positioned by the robot. We evaluate the estimated position accuracy through numerous experiments. We show that the moving distance of the RFID reader in the proposed scheme is lower than that in conventional schemes.

  • 22 OSIC Receiver for Hierarchical Constellation

    Deok-Kyu HWANG  Sooyong CHOI  Keum-Chan WHANG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E93-B No:9
      Page(s):
    2458-2461

    A transceiver employing hierarchical constellation encodes two hierarchies with different levels of protection and selectively decodes one or both of them, resulting in constellation inconsistency of encoding and decoding. Therefore, a conventional ordered successive interference cancellation (OSIC) receiver, which restores the signals as they are transmitted, can not be compatible with the constellation inconsistency. To mitigate this problem, an OSIC detector with the individual received bit rate per data stream is first designed. To further improve the error performance, the proposed detector is modified, for which distinct criteria are used for demodulation and cancellation. It is shown that the proposed detector achieves spectrally efficient detection while guaranteeing reliable communication.

  • Characteristics of Break Arcs Driven by Transverse Magnetic Field in a DC High-Voltage Resistive Circuit

    Tomohiro ATSUMI  Junya SEKIKAWA  Takayoshi KUBONO  

     
    PAPER

      Vol:
    E93-C No:9
      Page(s):
    1393-1398

    Break arcs are generated between pure silver electrical contacts in a DC high-voltage resistive circuit. The break arc is driven by the external magnetic field of a permanent magnet from horizontal direction of contacts. Electrical contacts are separated at constant opening speed at 75 mm/s. The maximum supply voltage is 300 V. The maximum circuit current when electrical contacts are closed is 20 A. The maximum output power of the supply is limited to 6.0 kW. The gap between the contacts and the magnet is defined as x. The gap is varied from 2.5 mm to 10.0 mm to change the magnetic flux density that affects the break arc. The break arc is observed with a high-speed camera. The effect of the magnetic field on the arc duration was examined. As a result, break arcs are successfully extinguished by the transverse magnetic field when the gap x is 2.5 mm. Then the length of the break arc just before lengthening of the break arc L and the Lorentz force that affects the break arc F are examined. The length L was almost constant for each gap x and independent of the circuit current I and the Lorentz force F. The break arc is driven by the magnetic field when the arc length reached a certain length that was determined by the strength of the magnetic flux density.

  • Effect of Contact Materials of Ag/SnO2 and Ag/ZnO on Rotational Motion of Break Arcs Driven by Radial Magnetic Field

    Junya SEKIKAWA  Takayoshi KUBONO  

     
    PAPER

      Vol:
    E93-C No:9
      Page(s):
    1387-1392

    Break arcs are generated between electrical contacts in a DC 42 V resistive circuit. Contact materials are Ag/SnO2 and Ag/ZnO. Circuit current when contacts are closed is varied from 5 A to 21 A. The radial magnetic field to drive break arcs is formed between the contact gap with a permanent magnet embedded in the cathode. The arc motion is observed with a high-speed camera. Experimental results with the magnet are compared with those without the magnet. Following results are shown. Similar experimental results to pure silver contacts are obtained for Ag/SnO2 and Ag/ZnO contact pairs. The rotational motion of the break arcs and the shortening effect of the arc duration are confirmed. The ring-shaped, wide and uniform traces are observed on the contact surfaces after break operations. This result shows the prevention effect of local erosion of electrical contacts and the reduction of total amount of contact erosion. The rotational frequency f is increased with the increase of the arc current Iarc. These results for Ag/SnO2 and Ag/ZnO contact pairs are similar to the results for pure silver contacts in our previous experiments. The rotational frequency of the break arc for the Ag/SnO2 and Ag/ZnO contacts is lower than that for the pure silver contacts.

  • Phase Offsets for Binary Sequences Using Order and Index

    Young-Joon SONG  

     
    LETTER-Coding Theory

      Vol:
    E93-A No:9
      Page(s):
    1697-1699

    When a zero offset reference sequence is defined, the i-bit shifted sequence has phase offset i with respect to the reference sequence. In this letter, we propose a new algorithm to compute phase offsets for a periodic binary sequence using the concept of order and index of an integer based on the number theoretical approach. We define an offset evaluation function that is used to calculate the phase offset, and derive properties of the function. Once the function is computed, the phase offset of the sequence is simply obtained by taking the index of it. The new algorithm overcomes the restrictions found in conventional methods on the length and the number of '0's and '1's in binary codes. Its application to the code acquisition is also investigated to show the proposed method is useful.

  • Adaptive Arbitration of Fair QoS Based Resource Allocation in Multi-Tier Computing Systems

    Naoki HAYASHI  Toshimitsu USHIO  Takafumi KANAZAWA  

     
    PAPER-Concurrent Systems

      Vol:
    E93-A No:9
      Page(s):
    1678-1683

    This paper proposes an adaptive resource allocation for multi-tier computing systems to guarantee a fair QoS level under resource constraints of tiers. We introduce a multi-tier computing architecture which consists of a group of resource managers and an arbiter. Resource allocation of each client is managed by a dedicated resource manager. Each resource manager updates resources allocated to subtasks of its client by locally exchanging QoS levels with other resource managers. An arbiter compensates the updated resources to avoid overload conditions in tiers. Based on the compensation by the arbiter, the subtasks of each client are executed in corresponding tiers. We derive sufficient conditions for the proposed resource allocation to achieve a fair QoS level avoiding overload conditions in all tiers with some assumptions on a QoS function and a resource consumption function of each client. We conduct a simulation to demonstrate that the proposed resource allocation can adaptively achieve a fair QoS level without causing any overload condition.

  • HMM-Based Voice Conversion Using Quantized F0 Context

    Takashi NOSE  Yuhei OTA  Takao KOBAYASHI  

     
    PAPER-Voice Conversion

      Vol:
    E93-D No:9
      Page(s):
    2483-2490

    We propose a segment-based voice conversion technique using hidden Markov model (HMM)-based speech synthesis with nonparallel training data. In the proposed technique, the phoneme information with durations and a quantized F0 contour are extracted from the input speech of a source speaker, and are transmitted to a synthesis part. In the synthesis part, the quantized F0 symbols are used as prosodic context. A phonetically and prosodically context-dependent label sequence is generated from the transmitted phoneme and the F0 symbols. Then, converted speech is generated from the label sequence with durations using the target speaker's pre-trained context-dependent HMMs. In the model training, the models of the source and target speakers can be trained separately, hence there is no need to prepare parallel speech data of the source and target speakers. Objective and subjective experimental results show that the segment-based voice conversion with phonetic and prosodic contexts works effectively even if the parallel speech data is not available.

  • Efficient Hybrid CMOS-Nano Circuit Design for Spiking Neurons and Memristive Synapses with STDP

    Ahmad AFIFI  Ahmad AYATOLLAHI  Farshid RAISSI  Hasan HAJGHASSEM  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E93-A No:9
      Page(s):
    1670-1677

    This paper introduces a new hybrid CMOS-Nano circuit for efficient implementation of spiking neurons and spike-timing dependent plasticity (STDP) rule. In our spiking neural architecture, the STDP rule has been implemented by using neuron circuits which generate two-part spikes and send them in both forward and backward directions along their axons and dendrites, simultaneously. The two-part spikes form STDP windows and also they carry temporal information relating to neuronal activities. However, to reduce power consumption, we take the circuitry of two-part spike generation out of the neuron circuit and use the regular shaped pulses, after the training has been performed. Furthermore, the performance of the rule as spike-timing correlation learning and character recognition in a two layer winner-take-all (WTA) network of integrate-and-fire neurons and memristive synapses is demonstrated as a case example.

  • Computing Spatio-Temporal Multiple View Geometry from Mutual Projections of Multiple Cameras

    Cheng WAN  Jun SATO  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E93-D No:9
      Page(s):
    2602-2613

    The spatio-temporal multiple view geometry can represent the geometry of multiple images in the case where non-rigid arbitrary motions are viewed from multiple translational cameras. However, it requires many corresponding points and is sensitive to the image noise. In this paper, we investigate mutual projections of cameras in four-dimensional space and show that it enables us to reduce the number of corresponding points required for computing the spatio-temporal multiple view geometry. Surprisingly, take three views for instance, we no longer need any corresponding point to calculate the spatio-temporal multiple view geometry, if all the cameras are projected to the other cameras mutually for two time intervals. We also show that the stability of the computation of spatio-temporal multiple view geometry is drastically improved by considering the mutual projections of cameras.

7961-7980hit(20498hit)