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9781-9800hit(20498hit)

  • An MEG Study of Temporal Characteristics of Semantic Integration in Japanese Noun Phrases

    Hirohisa KIGUCHI  Nobuhiko ASAKURA  

     
    PAPER-Human Information Processing

      Vol:
    E91-D No:6
      Page(s):
    1656-1663

    Many studies of on-line comprehension of semantic violations have shown that the human sentence processor rapidly constructs a higher-order semantic interpretation of the sentence. What remains unclear, however, is the amount of time required to detect semantic anomalies while concatenating two words to form a phrase with very rapid stimuli presentation. We aimed to examine the time course of semantic integration in concatenating two words in phrase structure building, using magnetoencephalography (MEG). In the MEG experiment, subjects decided whether two words (a classifier and its corresponding noun), presented each for 66 ms, form a semantically correct noun phrase. Half of the stimuli were matched pairs of classifiers and nouns. The other half were mismatched pairs of classifiers and nouns. In the analysis of MEG data, there were three primary peaks found at approximately 25 ms (M1), 170 ms (M2) and 250 ms (M3) after the presentation of the target words. As a result, only the M3 latencies were significantly affected by the stimulus conditions. Thus, the present results indicate that the semantic integration in concatenating two words starts from approximately 250 ms.

  • An Effective QoS Control Scheme for 3D Virtual Environments Based on User's Perception

    Takayuki KURODA  Takuo SUGANUMA  Norio SHIRATORI  

     
    PAPER-Media Communication

      Vol:
    E91-D No:6
      Page(s):
    1604-1612

    In this paper, we present a new three-dimensional (3D) virtual environment (3DVE) system named "QuViE/P", which can enhance quality of service (QoS), that users actually feel, as good as possible when resources of computers and networks are limited. To realize this, we focus on characteristics of user's perceptual quality evaluation on 3D objects. We propose an effective QoS control scheme for QuViE/P by introducing relationships between system's internal quality parameters and user's perceptual quality parameters. This scheme can appropriately maintain the QoS of the 3DVE system and it is expected to improve convenience when using 3DVE system where resources are insufficient. We designed and implemented a prototype of QuViE/P using a multiagent framework. The experiment results show that even when the computer resource is reduced to 20% of the required amount, the proposed scheme can maintain the quality of important objects to a certain level.

  • A Masking Model for Motion Sharpening Phenomenon in Video Sequences

    Akira FUJIBAYASHI  Choong Seng BOON  

     
    PAPER

      Vol:
    E91-A No:6
      Page(s):
    1408-1415

    In this paper, we show that motion sharpening phenomenon can be explained as a form of visual masking for a special case where a video sequence is composed of alternate frames with different level of sharpness. A frame of higher sharpness behaves to mask the ambiguity of a subsequent frame of lower sharpness and hence preserves the perceptive quality of the whole sequence. Borrowing the mechanism for visual masking, we formulated a quantitative model for deriving the minimum spatial frequency conditions which preserves the subjective quality of the frames being masked. The quantitative model takes into account three fundamental properties of the video signals, namely the size of motion, average luminance and the power of each frequency components. The psychophysical responses towards the changes of these properties are obtained through subjective assessment tests using video sequences of simple geometrical patterns. Subjective experiments on natural video sequences show that more than 75% of viewers could make no distinction between the original sequence and the one processed using the quantitative model.

  • A High-Q Active Inductor Circuit for Quasi-Millimeter-Wave Frequency Range

    Toru MASUDA  Yukio HATTORI  Hiroki SHIKAMA  Akira HYOGO  

     
    PAPER

      Vol:
    E91-C No:6
      Page(s):
    862-870

    This paper describes a novel high-Q active inductor circuit configuration composed of an operational transconductance amplifier (OTA) and an input RC network. Due to the phase rotation made by the input RC network, the active inductor circuit provides high-Q inductive impedance at higher frequencies. According to circuit simulation with design-kit of a 90-GHz-fT SiGe HBT technology, an inductance of more than 0.53 nH and Q of more than 80 can be obtained at quasi-millimeter-wave frequency, 24 GHz. The Q value is tunable by controlling the transconductance of the OTA. These features are also ensured by means of measurements of fabricated active inductor circuit. Since the active inductor circuit needs small chip area, which is 25% of a conventional passive inductor, the proposed active inductor contributes to implement a cost-effective high-Q notch filter for frequencies up to quasi-millimeter-wave frequencies.

  • A High Performance Spread Spectrum Clock Generator Using Two-Point Modulation Scheme

    Yao-Huang KAO  Yi-Bin HSIEH  

     
    PAPER

      Vol:
    E91-C No:6
      Page(s):
    911-917

    A new spread spectrum clock generator (SSCG) using two-point delta-sigma modulation is presented in this paper. Not only the divider is varied, but also the voltage controlled oscillator is modulated. This technique can enhance the modulation bandwidth so that the effect of EMI suppression is improved with lower order ΣΔ modulator and can simultaneously optimize the jitter and the modulation profile. In addition, the method of two-path is applied to the loop filter to reduce the capacitance value such that the total integration can be achieved. The proposed SSCG has been fabricated in a 0.35 µm CMOS process. The clock of 400 MHz with center spread ratios of 1.25% and 2.5% are verified. The peak EMI reduction is 19.73 dB for the case of 2.5%. The size of chip area is 0.900.89 mm2.

  • Compact Built-In Handset MIMO Antenna Using L-Shaped Folded Monopole Antennas

    Yongho KIM  Toshiteru HAYASHI  Yoshio KOYANAGI  Hisashi MORISHITA  

     
    PAPER-Smart Antennas & MIMO

      Vol:
    E91-B No:6
      Page(s):
    1743-1751

    A compact built-in handset antenna for multiple-input multiple-output (MIMO) system at 2 GHz, comprising two elements array of newly proposed L-shaped folded monopole antenna (LFMA), is evaluated under the multipath radio wave propagation environments. By analyzing the fundamental characteristics, mean effective gain (MEG), correlation, and channel capacity, the significant enhancement in the capability, as a handset MIMO antenna under practical use conditions, was confirmed. The performances were also compared to those of an array antenna comprising two planar inversed-F antenna (PIFA) elements in order to verify the effectiveness of the proposed antenna. The results show that the equivalent or improved performances can be realized, by using the proposed LFMA array with a compact size, taking only the volume of 44% of a PIFA array. The LFMA array provides almost the same bandwidth and enhanced isolation compared with a PIFA array, and the sufficiently low correlation and acceptable effective gain are obtained under the multipath radio wave propagation environments. In addition, a greater channel capacity than a PIFA array is achieved especially when the proposed LFMA array is inclined for the display-viewing mode, and moreover, an almost doubled increase in the channel capacity is obtained by using MIMO transmission compared with single-input single-output (SISO). This study also show that the MEG has much effects on the channel capacity, rather than the correlations, for the proposed antenna.

  • Quantitative Characterization of Surface Amino Groups of Plasma-Polymerized Films Prepared from Nitrogen-Containing Monomers for Bioelectronic Applications

    Hitoshi MUGURUMA  

     
    PAPER-Organic Molecular Electronics

      Vol:
    E91-C No:6
      Page(s):
    963-967

    The surface amino groups of plasma-polymerized films prepared from various nitrogen-containing monomers were quantitatively characterized for bioelectronic and biomedical applications. X-ray photoelectron spectroscopy (XPS) measurements were conducted on two kinds of surfaces: pristine surfaces of plasma-polymerized film prepared using various nitrogen-containing monomers, and theirs surfaces whose amino groups had been derivatized by a primary-amine-selective reagent carrying an XPS label. The XPS data showed that the maximum surface density of amino groups for this film was 8.41013 cm-2. Amino groups constituted 14-64% of all surface nitrogen atoms (NH/N), depending on the monomer used.

  • An Analysis of Antenna Integrated THz Oscillator Using a Negative Differential Resistance Transistor

    Katsumi FURUYA  Takeyoshi SUGAYA  Kazuhiro KOMORI  Masahiro ASADA  

     
    PAPER-Antennas

      Vol:
    E91-B No:6
      Page(s):
    1800-1805

    As THz wave has the advantages of enough resolution and penetration to materials, it has been examined to be used for the imaging system. The propagation distance of THz wave is limited to be short. That is also the advantage for application to the indoor wireless communication etc. For the achievement of the ultra-high frequency oscillator (and concurrently transmitter) device, the properties of small, electronic excitation, the antenna constructed and being on the wafer are important. For the purpose, the Negative differential resistance Dual channel transistor (NDR-DCT) proposed by AIST is utilized. In this paper, as an initial theoretical analysis, we simulated the oscillation frequency of this device at about 100 GHz-1THz within the Terahertz band on which the above applications was expected. The equivalent circuit model of NDR-DCT was shown based on the analogy with the resonant tunnelling diode (RTDs), and the antenna as the resonance circuit part was designed by the numerical analysis. The possibility of the THz oscillation of this device was confirmed. The slit reflector that we proposed can realize the slot antenna on the device effectively and is suitable for three terminal structure semiconductor. its manufacturing is relatively easy.

  • A Real-Time Decision Support System for Voltage Collapse Avoidance in Power Supply Networks

    Chen-Sung CHANG  

     
    PAPER-Artificial Intelligence and Cognitive Science

      Vol:
    E91-D No:6
      Page(s):
    1740-1747

    This paper presents a real-time decision support system (RDSS) based on artificial intelligence (AI) for voltage collapse avoidance (VCA) in power supply networks. The RDSS scheme employs a fuzzy hyperrectangular composite neural network (FHRCNN) to carry out voltage risk identification (VRI). In the event that a threat to the security of the power supply network is detected, an evolutionary programming (EP)-based algorithm is triggered to determine the operational settings required to restore the power supply network to a secure condition. The effectiveness of the RDSS methodology is demonstrated through its application to the American Electric Power Provider System (AEP, 30-bus system) under various heavy load conditions and contingency scenarios. In general, the numerical results confirm the ability of the RDSS scheme to minimize the risk of voltage collapse in power supply networks. In other words, RDSS provides Power Provider Enterprises (PPEs) with a viable tool for performing on-line voltage risk assessment and power system security enhancement functions.

  • Local Subspace Classifier with Transform-Invariance for Image Classification

    Seiji HOTTA  

     
    PAPER-Pattern Recognition

      Vol:
    E91-D No:6
      Page(s):
    1756-1763

    A family of linear subspace classifiers called local subspace classifier (LSC) outperforms the k-nearest neighbor rule (kNN) and conventional subspace classifiers in handwritten digit classification. However, LSC suffers very high sensitivity to image transformations because it uses projection and the Euclidean distances for classification. In this paper, I present a combination of a local subspace classifier (LSC) and a tangent distance (TD) for improving accuracy of handwritten digit recognition. In this classification rule, we can deal with transform-invariance easily because we are able to use tangent vectors for approximation of transformations. However, we cannot use tangent vectors in other type of images such as color images. Hence, kernel LSC (KLSC) is proposed for incorporating transform-invariance into LSC via kernel mapping. The performance of the proposed methods is verified with the experiments on handwritten digit and color image classification.

  • Online Chat Dependency: The Influence of Social Anxiety

    Chih-Chien WANG  Shu-Chen CHANG  

     
    PAPER-Media Communication

      Vol:
    E91-D No:6
      Page(s):
    1622-1627

    Recent developments in information technology have made it easy for people to "chat" online with others in real time, and many do so regularly. "Virtual" relationships can be attractive, especially for people with social interaction problems in the "real world". This study examines the influence on online chat dependency of three dimensions of social anxiety: general social situation fear, negative evaluation fear, and novel social situation fear. Participants of this study were 454 college students. The survey results show that negative evaluation fear and general social situation fear are relative to online chat dependency, while novel social situation fear does not seem to be a relevant factor.

  • Jigsaw-Puzzle-Like 3D Glyphs for Visualization of Grammatical Constraints

    Noritaka OSAWA  

     
    PAPER-Computer Graphics

      Vol:
    E91-D No:6
      Page(s):
    1804-1812

    Three-dimensional visualization using jigsaw-puzzle-like glyphs, or shapes, is proposed as a means of representing grammatical constraints in programming. The proposed visualization uses 3D glyphs such as convex, concave, and wireframe shapes. A semantic constraint, such as a type constraint in an assignment, is represented by an inclusive match between 3D glyphs. An application of the proposed visualization method to a subset of the Java programming language is demonstrated. An experimental evaluation showed that the 3D glyphs are easier to learn and enable users to more quickly understand their relationships than 2D glyphs and 1D symbol sequences.

  • A Low Distortion and Low Noise Differential Amplifier Suitable for 3G LTE Applications Using the Even- and Odd-Mode Impedance Differences of a Bias Circuit

    Toshifumi NAKATANI  Koichi OGAWA  

     
    PAPER

      Vol:
    E91-C No:6
      Page(s):
    844-853

    A low distortion and low noise differential amplifier using the difference between the even- and odd-mode impedances is proposed. In order to realize an amplifier with high OIP3 and low NF characteristics, the impedance of the bias circuit should be low (<300 Ω) at the difference frequency and high (>4 kΩ) at the carrier frequency. Although the frequency response of the bias circuit impedance can only meet these conditions with difficulty, owing to the 20 MHz Tx signal bandwidth for 3G LTE, the proposed amplifier can achieve the impedance difference using the properties of a differential configuration where the difference frequency signal is the even-mode and the carrier frequency is the odd-mode. It has been demonstrated that the NF of the proposed amplifier, which has been fabricated in 0.18 µm SiGe BiCMOS technology operating at 2.14 GHz, can be kept to 1.6 dB or less and an OIP3 of 9.0 dBm can be achieved, which is 3 dB higher than that of a conventional amplifier, in the condition where the power gain is greater than 18 dB.

  • Mechanism of Perceptual Categorization in the Pre-Linguistic Period

    Tamami SUDO  Ken MOGI  

     
    PAPER-Human Information Processing

      Vol:
    E91-D No:6
      Page(s):
    1649-1655

    In this study, we conducted a series of experiments using stimuli characterized by various attributes in order to understand the categorization process in an infant's pre-linguistic development. The infants are able to assign the same label to members within the same category by focusing attention on specific features or functions common to the members. The ability to categorize is likely to play an essential role in an infant's overall cognitive development. Specifically, we investigated how the infants use different strategies in the process of linguistic categorization. In one strategy, members of a single category are derived from perceptual similarities within the most representative members, i.e., the prototypical members. Alternatively, each membership is established by referring to the linguistic labels for each category provided by the caretaker, in a symbol grounding process. We found that the infant is able to employ these strategies in a flexible manner in its development. We discuss the interplay between different cognitive strategies, including the prototype effects in the infant's cognitive development and the implications for cortical mechanism involved.

  • Image and Video Quality Assessment Using LCD: Comparisons with CRT Conditions

    Sylvain TOURANCHEAU  Patrick LE CALLET  Dominique BARBA  

     
    INVITED PAPER

      Vol:
    E91-A No:6
      Page(s):
    1383-1391

    In this paper, the impact of display on quality assessment is addressed. Subjective quality assessment experiments have been performed on both LCD and CRT displays. Two sets of still images and two sets of moving pictures have been assessed using either an ACR or a SAMVIQ protocol. Altogether, eight experiments have been led. Results are presented and discussed, some differences are pointed out. Concerning moving pictures, these differences seem to be mainly due to LCD moving artefacts such as motion blur. LCD motion blur has been measured objectively and with psycho-physics experiments. A motion-blur metric based on the temporal characteristics of LCD can be defined. A prediction model have been then designed which predict the differences of perceived quality between CRT and LCD. This motion-blur-based model enables the estimation of perceived quality on LCD with respect to the perceived quality on CRT. Technical solutions to LCD motion blur can thus be evaluated on natural contents by this mean.

  • Analysis-by-Synthesis Sinusoidal Model without an Overlapping Scheme

    Jong-Hark KIM  Gyu-Hyeok JEONG  In-Sung LEE  

     
    LETTER-Multimedia Systems for Communications

      Vol:
    E91-B No:6
      Page(s):
    2094-2096

    A new sinusoidal modeling approach for the analysis-by-synthesis (AbS) of parameters that characterize a linear combination of damped sinusoids is proposed. In addition to the typical sinusoidal parameters, two different damping factors, which represent the time-varying nature of speech, were used to efficiently reduce the modeling error. Even though the proposed model does not employ the overlap-adding synthesis or smoothly interpolative synthesis scheme, it shows substantially better modeling performance in the synthesis of voiced and transient segments.

  • Artificial Spiking Neurons and Analog-to-Digital-to-Analog Conversion

    Hiroyuki TORIKAI  Aya TANAKA  Toshimichi SAITO  

     
    PAPER-Nonlinear Problems

      Vol:
    E91-A No:6
      Page(s):
    1455-1462

    This paper studies encoding/decoding function of artificial spiking neurons. First, we investigate basic characteristics of spike-trains of the neurons and fix parameter value that can minimize variation of spike-train length for initial value. Second we consider analog-to-digital encoding based upon spike-interval modulation that is suitable for simple and stable signal detection. Third we present a digital-to-analog decoder in which digital input is applied to switch the base signal of the spiking neuron. The system dynamics can be simplified into simple switched dynamical systems and precise analysis is possible. A simple circuit model is also presented.

  • Self-Organizing Map with False-Neighbor Degree between Neurons for Effective Self-Organization

    Haruna MATSUSHITA  Yoshifumi NISHIO  

     
    PAPER-Nonlinear Problems

      Vol:
    E91-A No:6
      Page(s):
    1463-1469

    In the real world, it is not always true that neighboring houses are physically adjacent or close to each other. in other words, "neighbors" are not always "true neighbors." In this study, we propose a new Self-Organizing Map (SOM) algorithm, SOM with False-Neighbor degree between neurons (called FN-SOM). The behavior of FN-SOM is investigated with learning for various input data. We confirm that FN-SOM can obtain a more effective map reflecting the distribution state of input data than the conventional SOM and Growing Grid.

  • A Study about the Relationship between Frame Quality and Single Video Quality

    Yoshikazu KAWAYOKE  Yuukou HORITA  

     
    LETTER

      Vol:
    E91-A No:6
      Page(s):
    1443-1445

    Digital video encapsulates the time series of a frame (still) images, where overall video quality can be obtained by using the quality of each frame image and the temporal information between the frame image. Coding of video produces degradation of these two types of information. These degradations can be classified as spatial degradation (static degradation) of a frame images and temporal degradation between frame image (dynamic degradation). In the framework of video quality evaluation it is necessary to consider those degradations, because their contents are strongly interdependable and quantification is problematic for these degradations. Therefore, the development of an objective video quality assessment method for single video quality requires to investigate how much static degradation and dynamic degradation affect single video quality. In this research, single video quality was predicted highly accuratly by using frame quality as static degradation and frame rate information as dynamic degradation.

  • Factors of Incomplete Adaptation for Color Reproduction Considering Subjective White Point Shift for Varying Illuminant

    Sung-Hak LEE  Myoung-Hwa LEE  Kyu-Ik SOHNG  

     
    LETTER

      Vol:
    E91-A No:6
      Page(s):
    1438-1442

    In this paper, we investigated the effect of chromaticity and luminance of surround to decide subject neutral white, and conducted a mathematical model of adapting degree for environment. Factors for adapting degree consist of two parts, adapting degree of ambient chromaticity and color saturation. These can be applied to color appearance models (CAM), actually improve the performance of color matching of CAM, hence would produce the method of image reproduction to general display systems.

9781-9800hit(20498hit)