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[Keyword] CTI(8214hit)

5541-5560hit(8214hit)

  • Bidirectional Path Setup Scheme Using on Upstream Label Set in Optical GMPLS Networks

    Eiji OKI  Nobuaki MATSUURA  Kohei SHIOMOTO  Naoaki YAMANAKA  

     
    PAPER-Network

      Vol:
    E87-B No:6
      Page(s):
    1569-1576

    Generalized Multi-Protocol Label Switching (GMPLS) is being developed in the Internet Engineering Task Force (IETF). In GMPLS-based wavelength-division-multiplexing (WDM) optical networks, a wavelength in a fiber is used as a label. In the existing GMPLS signaling protocol for bidirectional paths in WDM networks with the wavelength continuity constraint, bidirectional path setup fails with high probability because the upstream label allocated by the previous hop node may not be accepted at the transit node. To solve this problem, this paper proposes an efficient bidirectional label switched path (LSP) setup scheme based on an upstream label set. Called the Upstream Label Set (ULS) scheme, it is an extension of the existing GMPLS signaling protocol. The ULS scheme is consistent with the existing GMPLS signaling procedure and so offers backward compatibility. The numerical results suggest that when the number of the LSP setup retries is limited, the ULS scheme offers lower blocking probability than the existing GMPLS signaling scheme which uses only with the upstream label (UL). In addition, under the condition that the constraint of the number of LSP setup retries is relaxed, the LSP setup time of the ULS scheme is faster than that of the existing scheme. Furthermore, by using our developed prototype of the GMPLS control system, in which the ULS scheme was installed, we demonstrated that the ULS scheme successfully setup bidirectional LSPs.

  • Improving RF CMOS Active Inductor by Simple Loss Compensation Network

    Chen-Yi LEE  Jyh-Neng YANG  Yi-Chang CHENG  

     
    LETTER-Communication Devices/Circuits

      Vol:
    E87-B No:6
      Page(s):
    1681-1683

    An RF CMOS active inductor with a novel loss compensation circuit network is proposed. Performance of this active inductor can be improved by adding a novel network, which simultaneously reduces parallel and series losses. Consequently, this technique not only increases Q value, inductance, and operating frequency, but also reduces power consumption and circuit complexity. Simulation results show that better performance indices can be achieved, such as minimum total equivalent loss of 1 mΩ, maximum Q value about 3E5, and inductance value from 20 nH to 45 nH in the RF range of 0.6 GHz to 1.6 GHz. Power dissipation is around 1.76 mW under 2.5 V dc supply voltage.

  • Methods of Improving the Accuracy and Reproducibility of Objective Quality Assessment of VoIP Speech

    Akira TAKAHASHI  Masataka MASUDA  Atsuko KURASHIMA  

     
    PAPER-Multimedia Systems

      Vol:
    E87-B No:6
      Page(s):
    1660-1669

    VoIP is one of the key technologies for recent telecommunication services. The quality of its services should be discussed in subjective terms. Since subjective quality assessment is time-consuming and expensive, however, objective quality assessment which estimates subjective quality without carrying out subjective quality experiments is desirable. This paper discusses the performance of the objective quality measure that was standardized as ITU-T Recommendation P.862 and clarifies the quality factors that can be evaluated with satisfactory accuracy based on it. We found that P.862 can be applied to the evaluation of coding distortion, tandeming of codecs, transmission bit-errors, packet loss, and silence compression in a codec, at least for clean Japanese speech. In addition, we propose a method of estimating the subjective quality evaluation value from objective measurement results and show the validity of this method. We also evaluate the uniqueness of objective quality assessment based on P.862 from the viewpoints of the effect of measurement noise and the variation of test speech samples, and propose how to improve the reproducibility of objective quality assessment.

  • A Novel Feature Selection for Fuzzy Neural Networks for Personalized Facial Expression Recognition

    Dae-Jin KIM  Zeungnam BIEN  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1386-1392

    This paper proposes a novel feature selection method for the fuzzy neural networks and presents an application example for 'personalized' facial expression recognition. The proposed method is shown to result in a superior performance than many existing approaches.

  • TAJODA: Proposed Tactile and Jog Dial Interface for the Blind

    Chieko ASAKAWA  Hironobu TAKAGI  Shuichi INO  Tohru IFUKUBE  

     
    PAPER

      Vol:
    E87-D No:6
      Page(s):
    1405-1414

    There is a fatal difference in obtaining information between sighted people and the blind. Screen reading technology assists blind people in accessing digital documents by themselves helping to bridge such gap. However, these days they are becoming much more visual using various types of visual effects for sighted people to explore the information intuitively at a glance. It is very hard to convey visual effects non-visually and intuitively while retaining the original effects. In addition, it takes a long time to explore the information, since blind people use the keyboard for exploration, while sighted people use eye movement. This research aims at improving the non-visual exploration interface and improving the quality of non-visual information. Therefore, TAJODA (tactile jog dial interface) was proposed to solve these problems. It presents verbal information (text information) in the form of speech, while nonverbal information (visual effects) is represented in the form of tactile sensations. It uses a jog dial as an exploration device, which makes it possible to explore forward or backward intuitively in the speech information by spinning the jog dial clockwise or counterclockwise. It also integrates a tactile device to represent visual effects non-visually. Both speech and tactile information can be synchronized with the dial movements. The speed of spinning the dial affects the speech rate. The main part of this paper describes an experimental evaluation of the effectiveness of the proposed TAJODA interface. The experimental system used a preprocessed recorded human voice as test data. The training sessions showed that it was easy to learn how to use TAJODA. The comparison test session clearly showed that the subjects could perform the comparison task using TAJODA significantly faster (2.4 times faster) than with the comparison method that is closest to the existing screen reading function. Through this experiment, our results showed that TAJODA can drastically improve the non-visual exploration interface.

  • Reduction of Sound Localization Error for Non-individualized HRTF by Directional Weighting Function

    Sin-Lyul LEE  Lae-Hoon KIM  Koeng-Mo SUNG  

     
    PAPER-Engineering Acoustics

      Vol:
    E87-A No:6
      Page(s):
    1531-1536

    The non-individualized head related transfer function (HRTF) is known to have a few problems, which are referred to as the 'hole in the middle' phenomenon and 'front-back reversals.' To overcome these problems, an HRTF refinement technique was introduced, but unfortunately, this refinement technique causes sudden degradation in sound quality and difficulty in cross-talk cancellation because of notch frequency exaggeration. In this paper, an HRTF refinement using directional weighting function is proposed. This newly proposed technique weights ordinary HRTF according to its direction to amplify frontal sound intensity. Since the proposed technique does not exaggerate the notch frequency, spectral differences in the 'cone-of-confusion' region become more pronounced within overall audible frequencies, resulting in mitigating the sound degradation. In addition, the cross-talk cancellation can be done more easily. We verified the superiority of the proposed technique over the existing one by means of the sound localization and sound quality tests in headphone and loudspeakers.

  • Shot Detection from MPEG Compressed Video

    Hee-Chul HWANG  Duk-Gyoo KIM  

     
    LETTER

      Vol:
    E87-A No:6
      Page(s):
    1509-1513

    A method for automatic and fast shot detection for the MPEG video is proposed. Shot detection is the first step in analyzing and searching a large amount of video data. Our proposed method is based on activity of images as well as intra MBs in the video frame. It is possible to detect scene changes rapidly by using information from the compressed MPEG video data without the need for full-frame decoding. Experimental results show that the proposed method can provide good performance at a low computational cost.

  • "Man-Computer Symbiosis" Revisited: Achieving Natural Communication and Collaboration with Computers

    Neal LESH  Joe MARKS  Charles RICH  Candace L. SIDNER  

     
    INVITED PAPER

      Vol:
    E87-D No:6
      Page(s):
    1290-1298

    In 1960, the famous computer pioneer J.C.R. Licklider described a vision for human-computer interaction that he called "man-computer symbiosis. " Licklider predicted the development of computer software that would allow people "to think in interaction with a computer in the same way that you think with a colleague whose competence supplements your own. " More than 40 years later, one rarely encounters any computer application that comes close to capturing Licklider's notion of human-like communication and collaboration. We echo Licklider by arguing that true symbiotic interaction requires at least the following three elements: a complementary and effective division of labor between human and machine; an explicit representation in the computer of the user's abilities, intentions, and beliefs; and the utilization of nonverbal communication modalities. We illustrate this argument with various research prototypes currently under development at Mitsubishi Electric Research Laboratories (USA).

  • Improvement of AMC-MIMO Multiplexing Systems with Selection Transmit Diversity Techniques

    Intae HWANG  Jungyoung SON  Sukki HAHN  Mingoo KANG  Young-Hwan YOU  Changeon KANG  

     
    LETTER-Transmission Systems and Transmission Equipment

      Vol:
    E87-B No:6
      Page(s):
    1684-1687

    In this letter, adaptive modulation and coding (AMC) is combined with multiple input multiple output (MIMO) multiplexing to improve the throughput performance of AMC. In addition, a system that adopts selection transmit diversity (STD) in the AMC-MIMO multiplexing system, AMC-STD-MIMO multiplexing system, is proposed. STD in our simulation selects 2 transmission antennas from 4 antennas and AMC-MIMO multiplexing process operates with the selected antennas. The computer simulation is performed in a flat Rayleigh fading channel. The results show that the proposed AMC-STD-MIMO multiplexing system achieves the SNR gain of 4.0 dB, compared to the AMC-MIMO multiplexing system at 3 Mbps throughput.

  • Limiting the Length of BET for Tunnel-Based IP Fast Handover

    HeeYoung JUNG  SeokJoo KOH  JaeHong MIN  DaeYoung KIM  

     
    LETTER

      Vol:
    E87-A No:6
      Page(s):
    1527-1530

    Next generation wired/wireless networks will be based on IP technology. In the IP based networks, it is crucially required to support seamless mobility especially for proving real-time services in the mobile environment. The conventional Mobile IP protocols cannot satisfy such seamless mobility requirements for real-time services. Therefore various extensions of Mobile IP are being proposed. In this paper, we propose a new handover scheme to enhance the existing tunnel-based fast handover method, which is a typical Mobile IP extension to support seamless mobility. It is shown that the proposed method reduces the traffic overhead in the networks. It is expected that the proposed method will be particularly useful in the IP-based networks in which there are a number of users simultaneously using the long-lived real-time services, or in the condition that the traffic overhead is considered as a critical performance measure.

  • Wearable Moment Display Device for Nonverbal Communications

    Hideyuki ANDO  Maki SUGIMOTO  Taro MAEDA  

     
    PAPER

      Vol:
    E87-D No:6
      Page(s):
    1354-1360

    There has recently been considerable interest in research on wearable non-grounded force display. However, there have been no developments for the communication of nonverbal information (ex. tennis and golf swing). We propose a small and lightweight wearable force display to present motion timing and direction. The display outputs a torque using rotational moment and mechanical brakes. We explain the principle of this device, and describe an actual measurement of the torque and torque sensitivity experiments.

  • Recognition of English Calling Cards by Using Enhanced Fuzzy Radial Basis Function Neural Networks

    Kwang-Baek KIM  Young-Ju KIM  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1355-1362

    In this paper, we proposed the novel method for the recognition of English calling cards by using the contour tracking algorithm and the enhanced fuzzy RBF (Radial Basis Function) neural networks. The recognition of calling cards consists of the extraction phase of character areas and the recognition phase of extracted characters. In the extraction phase, first of all, noises are removed from the images of calling cards, and the feature areas including character strings are separated from the calling card images by using the horizontal smearing method and the 8-directional contour tracking method. And using the image projection method the feature areas are split into the areas of individual characters. We also proposed the enhanced fuzzy RBF neural network that organizes the middle layer effectively by using the enhanced fuzzy ART neural network adjusting the vigilance parameter dynamically according to the similarity between patterns. In the recognition phase, the proposed fuzzy neural network was applied to recognize individual characters. Our experiment result showed that the proposed recognition algorithm has higher success rate of recognition and faster learning time than the conventional RBF network based recognitions.

  • A Class of Ternary Sequence Sets with a Zero-Correlation Zone

    Takafumi HAYASHI  Satoshi OKAWA  

     
    PAPER-Coding Theory

      Vol:
    E87-A No:6
      Page(s):
    1591-1598

    A new class of ternary sequence having a zero-correlation zone (zcz), based on Hadamard matrices, is presented. The proposed sequence construction can simultaneously generate a finite-length ternary zcz sequence set and a periodic ternary zcz sequence set. The generated finite-length ternary zcz sequence set has a zero-correlation zone for an aperiodic function. The generated periodic ternary zcz sequence set has a zero-correlation zone for even and odd correlation functions.

  • The Structures of CPW PHEMT's for Applications of Millimeter-Waves

    Byeong-Ok LIM  Tae-Shin KANG  Bok-Hyung LEE  Mun-Kyo LEE  Jin-Koo RHEE  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1323-1329

    The parasitic capacitances induced in the spaces between an air-bridge interconnection and a drain pad (Cad), and between an air-bridge interconnection and a gate head (Cag) from a power CPW PHEMT are not negligible. In this paper, a modified equivalent circuit model for a CPW PHEMT and an improved CPW PHEMT for millimeter-wave applications are proposed. These were proved by measuring the fabricated CPW PHEMT and improved CPW PHEMT. These capacitances were confirmed by measuring the gate-source coupling using CPW PHEMT patterns without an active layer. From the measurements, the improved CPW PHEMT has the lowest coupling (loss) and the highest S21 gain among four different types tested at 60 GHz. And the improved CPW PHEMT is a feasible device which can be directly applied in millimeter-waves as a power device.

  • Conservative Extension of Connection Retrieval Time for Wireless Packet Service

    Cheon Won CHOI  Woo Cheol SHIN  Jin Kyung PARK  Jun HA  Ho-Kyoung LEE  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1417-1425

    In provisioning packet data service on wireless cellular networks, a scheme of altering connection status between mobile and base stations appeared intending to efficiently utilize resource during idle periods. In such a scheme, connection components are sequentially released as an idle period persists, while the transmitting station converts to an transmission activity mode as the station is loaded with packets. However, actual resume of transmission activity is postponed by connection retrieval time to restore lost connection components. In general, an idle period affects the following connection retrieval time, which in turn produces an impact on the forthcoming idle period. Such chain reaction also makes a significant influence on overall packet delay performance. In this paper, as a way of improving packet delay performance, we propose two schemes identified as conservative extension and load threshold schemes. In the conservative extension scheme, we intentionally extend connection retrieval times so that each connection retrieval time is guaranteed not to be lower than a certain value. On the other hand, according to the load threshold scheme, a retrieval of lost connection components is postponed until packets are accumulated at the transmitting station up to a prescribed threshold. An increase in the value and threshold incurs an additional stand-by before resuming transmission activity in both proposed schemes. In turn, such intentional stand-by may contribute to regulating the length of idle period and connection retrieval time, and subsequently improving packet delay performance. To inspect the impact of conservative extension and load threshold schemes on packet delay performance, we first investigate the properties of idle periods. Secondly, for Poisson packet arrivals, we present an analytical method to exactly calculate the moments of packet delay time (at steady state) in each scheme. From numerical examples, we confirm the existence of non-trivial optimal value and threshold minimizing average packet delay or packet delay variation and conclude that conservative extension and load threshold schemes are able to enhance packet delay performance in various environments.

  • NTM-Agent: Text Mining Agent for Net Auction

    Yukitaka KUSUMURA  Yoshinori HIJIKATA  Shogo NISHIDA  

     
    PAPER

      Vol:
    E87-D No:6
      Page(s):
    1386-1396

    Net auctions have been widely utilized with the recent development of the Internet. However, it is a problem that there are too many items for bidders to select the most suitable one. We aim at supporting the bidders on net auctions by automatically generating a table which contains the features of several items for comparison. We construct a system called NTM-Agent (Net auction Text Mining Agent). The system collects web pages of items and extracts the items' features from the pages. After that, it generates a table which contains the extracted features. This research focuses on two problems in the process. The first problem is that if the system collects items automatically, the results contain the items which is different from the items of the user's target. The second problem is that the descriptions in net auctions are not uniform (There are different formats such as sentences, items and tables. The subjects of some sentences are omitted. ). Therefore, it is difficult to extract the information from the descriptions by conventional methods of information extraction. This research proposes methods to solve the problems. For the first problem, NTM-Agent filters the items by correlation rules about the keywords in the titles and the item descriptions. These rules are created semi-automatically by a support tool. For the second problem, NTM-Agent extracts the information by distinguishing the formats. It also learns the feature values from plain examples for the future extraction.

  • A One-Time Password Authentication Method for Low Spec Machines and on Internet Protocols

    Takasuke TSUJI  Akihiro SHIMIZU  

     
    PAPER-Internet

      Vol:
    E87-B No:6
      Page(s):
    1594-1600

    Applications for transforming money or personal information are increasingly common on the Internet and in mobile communications. These applications require user authentication for confirming legal users. One-time password authentication methods change the verifier every time by sending the present verifier along with the next verifier. However, such methods risk attacks because those protocols use two verifiers every session. The SAS (Simple And Secure password authentication protocol) is a one-time password authentication method that the method uses a hash function five times, but it requires high overhead on low spec machines. In this paper, we propose a new method, SAS-2, which reduces overhead of hash function adaptation by 40%. This method has a mutual authentication phase, which maintains synchronous data communications in its authentication procedure. Moreover, SAS-2 can be applied to key-free systems.

  • Reflection Routing: A Simple Approach for Contention Resolution in All-Optical Packet Switched Networks

    Hiroyuki YOKOYAMA  Hajime NAKAMURA  Shinichi NOMOTO  

     
    PAPER-Network

      Vol:
    E87-B No:6
      Page(s):
    1561-1568

    Packet loss is a serious problem due to the shortage of optical buffers in all-optical packet switched networks. In order to reduce packet losses, a dynamic routing method called 'deflection routing' has been proposed. Deflection routing, however, requires an optical switch to modify routing tables and packet labels for overflowing packets, so this routing method may also lead to other implementation problems in packet routing and forwarding. This paper proposes a simple routing method called 'reflection routing' which utilizes optical transport links as optical buffers to improve the quality of service in optical packet switched networks in terms of packet loss ratio. We numerically demonstrate the effectiveness and applicability of reflection routing.

  • Judgment Biases of Temporal Order during Apparent Self-Motion

    Wataru TERAMOTO  Hiroshi WATANABE  Hiroyuki UMEMURA  Katsunori MATSUOKA  Shinichi KITA  

     
    PAPER

      Vol:
    E87-D No:6
      Page(s):
    1466-1476

    Virtual reality system is one of the most useful tools for investigating the characteristics of human perception in dynamic visual environment because we can easily and appropriately manipulate parameters of three-dimensional stimuli of vision in accordance with our purpose. In the present study we examined how the brain processes local stimuli during the global sensation of self-motion (vection) in view of temporal information processing -- perceptual latency -- with temporal order judgment task. In Experiment 1 we demonstrated that the targets in the left visual field were perceived prior to those in the right visual field when an observer stared at rightward optokinetic stimuli or perceived self-motion leftward, and vice versa. Especially at 16.0 deg of target eccentricity the biases were much larger with the continuous exposure of optokinetic stimuli than with their intermittent exposure; the former compelled observers to perceive self-motion and the latter hardly did. In Experiment 2 we examined the relationship between the occurrence of vection and temporal order judgments as the exposure duration of optokinetic stimuli was fixed between conditions, and showed that the biases were larger when vection occurred than when it did not. In Experiment 3 we showed that the biases were not modulated by the speed of optokinetic stimuli and not related with the speed of perceived self-motion. This phenomenon can be explained based on exogenous components of attention, the shift of the reference frame for determining the order in which objects come into awareness and imbalance between hemispheric activities. The mechanism is ecologically reasonable in that it allows us to be aware of the incoming events as soon as possible and to avoid any dangerous situations.

  • Gate-to-Bulk Overlap Capacitance Extraction and Its Circuit Verification

    Masanori SHIMASUE  Yasuo KAWAHARA  Takeshi SANO  Hitoshi AOKI  

     
    PAPER

      Vol:
    E87-C No:6
      Page(s):
    929-932

    Gate-to-bulk overlap capacitance (CGBO) cannot be ignored for long gate channel MOSFET's that are used for various I/O and analog circuits. We present a simple and yet accurate CGBO measurement and extractions by using a group of MOSFET's. Dedicated test structures using 0.18 µm shallow trench isolation technology were fabricated for the purpose. The effect of CGBO has been successfully analyzed. Validity of the CGBO extraction has been verified by comparing measured time delay of 51 stage ring oscillators with simulated data using our customized UCB SPICE3 simulator.

5541-5560hit(8214hit)