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1561-1580hit(4570hit)

  • Temporal Coalescing on Window Extents over Data Streams

    Mohammed AL-KATEB  Sasi Sekhar KUNTA  Byung Suk LEE  

     
    PAPER

      Vol:
    E94-D No:3
      Page(s):
    489-503

    This paper focuses on the coalescing operator applied to the processing of continuous queries with temporal functions and predicates over windowed data streams. Coalescing is a key operation enabling the evaluation of interval predicates and functions on temporal tuples. Applying this operation for temporal query processing on windowed streams brings the challenge of coalescing tuples in a window extent each time the window slides over the data stream. This coalescing becomes even more involving when some tuples arrive out of order. This paper distinguishes between eager coalescing and lazy coalescing, the two known coalescing schemes. The former coalesces tuples during window extent update and the latter does it during window extent scan. With these two schemes, the paper first presents algorithms for updating a window extent for both tuple-based and time-based windows. Then, the problem of optimally selecting between eager and lazy coalescing for concurrent queries is formulated as a 0-1 integer programming problem. Through extensive performance study, the two schemes are compared and the optimal selection is demonstrated.

  • Optimized Median Lifting Scheme for Lossy Image Compression

    Do QUAN  Yo-Sung HO  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E94-D No:3
      Page(s):
    721-724

    In JPEG2000, the Cohen-Daubechies-Feauveau (CDF) 9/7-tap wavelet filter was implemented by using the conventional lifting scheme. However, the filter coefficients remain complex, and the conventional lifting scheme disregards image edges in the coding process. In order to solve these issues, we propose a lifting scheme in two steps. In the first step, we select the appropriate filter coefficients; in the second step, we employ a median operator to regard image edges. Experimental results show that the peak signal-to-noise ratio (PSNR) value of the proposed lifting scheme is significantly improved, by up to 0.75 dB on average, compared to that of the conventional lifting scheme in the CDF 9/7-tap wavelet filter of JPEG2000.

  • GKJ: Group KJ Method Support System Utilizing Digital Pens

    Motoki MIURA  Taro SUGIHARA  Susumu KUNIFUJI  

     
    PAPER

      Vol:
    E94-D No:3
      Page(s):
    456-464

    Practitioners of the Jiro Kawakita (KJ) method, a method for organizing ideas, typically use paper labels and four-colored ball-point pens to record their ideas during the creative thinking process. A similar approach is used in group KJ method sessions; however, the effectiveness of capturing and sharing the diagrams and information is limited because of the large amount of paper required. Considering the merits of the conventional paper-pen approach and the demand for quick sharing of diagrams after a session, we designed and implemented a system to digitize group KJ sessions--not just the diagrams but also the details of the creative process. We used digital pens during the session to capture the position and orientation of labels as well as their content. We confirmed the efficiency of our system by applying it to several GKJ sessions.

  • Query Expansion and Text Mining for ChronoSeeker -- Search Engine for Future/Past Events --

    Hideki KAWAI  Adam JATOWT  Katsumi TANAKA  Kazuo KUNIEDA  Keiji YAMADA  

     
    PAPER

      Vol:
    E94-D No:3
      Page(s):
    552-563

    This paper introduces a future and past search engine, ChronoSeeker, which can help users to develop long-term strategies for their organizations. To provide on-demand searches, we tackled two technical issues: (1) organizing efficient event searches and (2) filtering out noises from search results. Our system employed query expansion with typical expressions related to event information such as year expressions, temporal modifiers, and context terms for efficient event searches. We utilized a machine-learning technique of filtering noise to classify candidates into information or non-event information, using heuristic features and lexical patterns derived from a text-mining approach. Our experiment revealed that filtering achieved an 85% F-measure, and that query expansion could collect dozens more events than those without expansion.

  • Estimation of Blood Pressure Measurements for Hypertension Diagnosis Using Oscillometric Method

    Youngsuk SHIN  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E94-A No:2
      Page(s):
    806-812

    Blood pressure is the measurement of the force exerted by blood against the walls of the arteries. Hypertension is a major risk factor of cardiovascular diseases. The systolic and diastolic blood pressures obtained from the oscillometric method could carry clues about hypertension. However, blood pressure is influenced by individual traits such as physiology, the geometry of the heart, body figure, gender and age. Therefore, consideration of individual traits is a requisite for reliable hypertension monitoring. The oscillation waveforms extracted from the cuff pressure reflect individual traits in terms of oscillation patterns that vary in size and amplitude over time. Thus, uniform features for individual traits from the oscillation patterns were extracted, and they were applied to evaluate systolic and diastolic blood pressures using two feedforward neural networks. The measurements of systolic and diastolic blood pressures from two neural networks were compared with the average values of systolic and diastolic blood pressures obtained by two nurses using the auscultatory method. The recognition performance was based on the difference between the blood pressures measured by the auscultation method and the proposed method with two neural networks. The recognition performance for systolic blood pressure was found to be 98.2% for 20 mmHg, 93.5% for 15 mmHg, and 82.3% for 10 mmHg, based on maximum negative amplitude. The recognition performance for diastolic blood pressure was found to be 100% for 20 mmHg, 98.8% for 15 mmHg, and 88.2% for 10 mmHg based on maximum positive amplitude. In our results, systolic blood pressure showed more fluctuation than diastolic blood pressure in terms of individual traits, and subjects with prehypertension or hypertension (systolic blood pressure) showed a stronger steep-slope pattern in 1/3 section of the feature windows than normal subjects. The other side, subjects with prehypertension or hypertension (diastolic blood pressure) showed a steep-slope pattern in front of the feature windows (2/3 section) than normal subjects. This paper presented a novel blood pressure measurement system that can monitor hypertension using personalized traits. Our study can serve as a foundation for reliable hypertension diagnosis and management based on consideration of individual traits.

  • In Situ Observation of Reduction Behavior of Cytochrome c Adsorbed on Glass Surface by Slab Optical Waveguide Spectroscopy

    Naoki MATSUDA  Hirotaka OKABE  Masaki FUJII  Masayoshi MATSUI  Yusuke AYATO  Akiko TAKATSU  Kenji KATO  

     
    PAPER

      Vol:
    E94-C No:2
      Page(s):
    170-175

    In situ observation of the adsorption process and the states of cytochrome c on glass/solution interfaces, and the functionality of the reduction reaction of adsorbed cytochorome c were performed by using slab optical waveguide (SOWG) spectroscopy. The peak position of the absorption band of cytochorome c adsorbed on a bare glass surface was almost the same as that of that in solution. The cytochorome c adsorbed on glass/solution interface was reduced by sodium dithionite solution. The adsorbed cytochorome c was still maintained its functionality after immobilization.

  • Millimeter-Wave Imaging System Using Simultaneous Frequency-Encoding Technique

    Hirokazu KAMODA  Thomas DERHAM  Toru IWASAKI  Takao KUKI  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E94-C No:2
      Page(s):
    206-214

    We fabricated and evaluated a prototype imaging system using the Simultaneous Frequency-Encoding technique, which is an active imaging technique that is potentially capable of fast frame-frequency imaging using a frequency-scanning antenna with only a single transceiver. The prototype performed simultaneous acquisition of pixels in elevation using Simultaneous Frequency-Encoding and performed a mechanical scan in azimuth. We also studied a ranging technique and incorporated it into the prototype. The ranging technique for Simultaneous Frequency-Encoding must take into account the characteristics of the frequency-scanning antenna, which are fundamental to Simultaneous Frequency-Encoding. We verified that ordinary range processing can be performed before frequency analysis with Simultaneous Frequency-Encoding, giving both range and angular profiles. The prototype was evaluated based on the radiation patterns of a receiver antenna comprising the frequency-scanning antenna and a reflector, on which both the image quality and ranging performance depend. Finally we conducted actual imaging tests and confirmed the capability of through-obstacle imaging. The frame frequency was only 0.1 Hz, which was due to the use of a slow mechanical scan in azimuth. However, assuming electronic beam forming is used instead of the mechanical scan, the frame frequency can be improved to several Hertz.

  • Regularized Maximum Likelihood Linear Regression Adaptation for Computer-Assisted Language Learning Systems

    Dean LUO  Yu QIAO  Nobuaki MINEMATSU  Keikichi HIROSE  

     
    PAPER-Educational Technology

      Vol:
    E94-D No:2
      Page(s):
    308-316

    This study focuses on speaker adaptation techniques for Computer-Assisted Language Learning (CALL). We first investigate the effects and problems of Maximum Likelihood Linear Regression (MLLR) speaker adaptation when used in pronunciation evaluation. Automatic scoring and error detection experiments are conducted on two publicly available databases of Japanese learners' English pronunciation. As we expected, over-adaptation causes misjudgment of pronunciation accuracy. Following the analysis, we propose a novel method, Regularized Maximum Likelihood Regression (Regularized-MLLR) adaptation, to solve the problem of the adverse effects of MLLR adaptation. This method uses a group of teachers' data to regularize learners' transformation matrices so that erroneous pronunciations will not be erroneously transformed as correct ones. We implement this idea in two ways: one is using the average of the teachers' transformation matrices as a constraint to MLLR, and the other is using linear combinations of the teachers' matrices to represent learners' transformations. Experimental results show that the proposed methods can better utilize MLLR adaptation and avoid over-adaptation.

  • RF CMOS Integrated Circuit: History, Current Status and Future Prospects

    Noboru ISHIHARA  Shuhei AMAKAWA  Kazuya MASU  

     
    INVITED PAPER

      Vol:
    E94-A No:2
      Page(s):
    556-567

    As great advancements have been made in CMOS process technology over the past 20 years, RF CMOS circuits operating in the microwave band have rapidly developed from component circuit levels to multiband/multimode transceiver levels. In the next ten years, it is highly likely that the following devices will be realized: (i) versatile transceivers such as those used in software-defined radios (SDR), cognitive radios (CR), and reconfigurable radios (RR); (ii) systems that operate in the millimeter-wave or terahertz-wave region and achieve high speed and large-capacity data transmission; and (iii) microminiaturized low-power RF communication systems that will be extensively used in our everyday lives. However, classical technology for designing analog RF circuits cannot be used to design circuits for the abovementioned devices since it can be applied only in the case of continuous voltage and continuous time signals; therefore, it is necessary to integrate the design of high-speed digital circuits, which is based on the use of discrete voltages and the discrete time domain, with analog design, in order to both achieve wideband operation and compensate for signal distortions as well as variations in process, power supply voltage, and temperature. Moreover, as it is thought that small integration of the antenna and the interface circuit is indispensable to achieve miniaturized micro RF communication systems, the construction of the integrated design environment with the Micro Electro Mechanical Systems (MEMS) device etc. of the different kind devices becomes more important. In this paper, the history and the current status of the development of RF CMOS circuits are reviewed, and the future status of RF CMOS circuits is predicted.

  • Remarks on Transient Amplitude Analysis of MOS Cross-Coupled Oscillators

    Amir EBRAHIMI  Hossein MIAR NAIMI  Habib ADRANG  

     
    PAPER-Electronic Circuits

      Vol:
    E94-C No:2
      Page(s):
    231-239

    In this paper, closed-form analytical equations for the time-domain amplitude of the MOS cross-coupled oscillators are derived. The procedure of the paper is based on estimating an accurate equation for describing the behavior of the cross-coupled MOS configurations and finding a reasonable solution for the nonlinear differential equation governing the circuit. The solution method is presented for a general equation and is valid for all possible second-order oscillators. Both of the long channel and short channel transistor topologies have been investigated. The resulted equations are in a good agreement with simulation results for a wide range of the circuit parameters and enable us to analyze and synthesize the oscillators with the desired transient behavior.

  • The Precoder Design for Intrablock MMSE Equalization and Block Delay Detection with a Modified Oblique Projection Framework

    Chun-Hsien WU  

     
    LETTER-Digital Signal Processing

      Vol:
    E94-A No:2
      Page(s):
    829-832

    This letter presents a method to enable the precoder design for intrablock MMSE equalization with previously proposed oblique projection framework. The joint design of the linear transceiver with optimum block delay detection is built. Simulation results validate the proposed approach and show the superior BER performance of the optimized transceiver.

  • A 1 Gb/s 3.8 pJ/bit Differential Input BPSK Detection Scheme for UWB-IR Communication Using 180 nm CMOS Technology

    Mohiuddin HAFIZ  Nobuo SASAKI  Takamaro KIKKAWA  

     
    PAPER-Electronic Circuits

      Vol:
    E94-C No:2
      Page(s):
    240-247

    A CMOS detection procedure for ultra-wideband impulse radio (UWB-IR) communication system, employing Bi-Phase Shift Keying (BPSK) modulation scheme, is presented here. The chip was designed and fabricated in a 180 nm CMOS process and it requires a supply voltage of 1.8 V, with a die area of 0.01 mm2. A train of Gaussian Monocycle Pulses (GMP), modulated by a random data sequence of 1 Gb/s, has been detected successfully by the detector. Ability to process differential data without using conventional blocks like mixer, correlator etc. while consuming a very low power (3.8 pJ/bit for a data rate of 1 Gb/s) is the novelty of this work. The detection scheme employing a simple architecture with a noncoherent detection mechanism is well suited for UWB-IR communication system.

  • Yellow-Blue Component Modification of Color Image for Protanopia or Deuteranopia

    Go TANAKA  Noriaki SUETAKE  Eiji UCHINO  

     
    LETTER-Image

      Vol:
    E94-A No:2
      Page(s):
    884-888

    A new recoloring method to improve visibility of indiscriminable colors for protanopes or deuteranopes is proposed. In the proposed method, yellow-blue components of a color image perceived by protanopes/deuteranopes are adequately modified. Moreover, the gamut mapping is considered to obtain proper output color values in this method.

  • Simple Local Multicast Tree Extension against Intermittently Disconnected State by Exploiting Motion Affinity

    Kwang Bin IM  Kyungran KANG  Young-Jong CHO  

     
    LETTER-Network

      Vol:
    E94-B No:2
      Page(s):
    565-568

    This letter proposes a simple k-hop flooding scheme for the temporarily lost child node of a multicast tree in a mobile ad hoc network where a group of nodes move together within a bound. Through simulation, we show that our scheme improves the packet delivery ratio of MAODV to be comparable to the epidemic routing with only small additional duplicate packets.

  • The Effects of Spatial Correlation on Multiple Antenna Techniques with Multiuser Scheduling

    Haelyong KIM  Wan CHOI  Hyuncheol PARK  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E94-B No:2
      Page(s):
    591-594

    This letter investigates the effects of spatial correlation on several multiple antenna schemes in multiuser environments. Using an order statistics upper bound on achievable capacity, we quantify the interaction among spatial correlation, spatial diversity, spatial multiplexing and multiuser diversity. Also, it is verified that the upper bound is tighter than asymptotic capacity when the number of users is relatively small.

  • Surface Plasmon Excitation and Emission Light Properties Using Hybrid Setup of Prism and Grating Coupling

    Kazunari SHINBO  Yuta HIRANO  Masayuki SAKAI  Masahiro MINAGAWA  Yasuo OHDAIRA  Akira BABA  Keizo KATO  Futao KANEKO  

     
    BRIEF PAPER

      Vol:
    E94-C No:2
      Page(s):
    196-197

    A half-cylindrical BK-7 prism/dielectric film with a grating/Ag film/fluorescent polymer film structure was prepared, and its surface plasmon (SP) excitation property was investigated. It was confirmed experimentally that SP excitations are possible in this structure by using prism and grating couplings. The SP excitation property depended on the direction of the grating vector. Furthermore, intense photoluminescence was observed when the SPs were simultaneously excited at the Ag/polymer interface by prism coupling and at the Cytop/Ag interface by grating coupling.

  • Energy-Saving Stochastic Scheduling of a Real-Time Parallel Task with Varying Computation Amount on Multi-Core Processors

    Wan Yeon LEE  Kyong Hoon KIM  

     
    LETTER-Systems and Control

      Vol:
    E94-A No:2
      Page(s):
    842-845

    The proposed scheduling scheme minimizes the mean energy consumption of a real-time parallel task, where the task has the probabilistic computation amount and can be executed concurrently on multiple cores. The scheme determines a pertinent number of cores allocated to the task execution and the instant frequency supplied to the allocated cores. Evaluation shows that the scheme saves manifest amount of the energy consumed by the previous method minimizing the mean energy consumption on a single core.

  • An Image Quality Assessment Model Based on the MPEG-7 Descriptor

    Masaharu SATO  Yuukou HORITA  

     
    PAPER-Evaluation

      Vol:
    E94-A No:2
      Page(s):
    509-518

    Our research is focused on examining the Image Quality Assessment Model based on the MPEG-7 descriptor and the No Reference model. The model retrieves a reference image using image search and evaluate its subject score as a pseudo Reduced Reference model. The MPEG-7 descriptor was originally used for content retrieval, but we discovered that the MPEG-7 descriptor can also be used for image quality assessment. We examined the performance of the proposed model and the results revealed that this method has a higher performance rating than the SSIM.

  • A Time-Variant Analysis of Phase Noise in Series Quadrature Oscillators

    Jinhua LIU  Guican CHEN  Hong ZHANG  

     
    PAPER

      Vol:
    E94-A No:2
      Page(s):
    574-582

    This paper presents a systemic analysis for phase noise performances of the series quadrature oscillator (QOSC) by using the time-variant impulse sensitivity function (ISF) model. The effective ISF for each noise source in the oscillator is derived mathematically. According to these effective ISFs, the explicit closed-form expression for phase noise due to the total thermal noise in the series QOSC is derived, and the phase noise contribution from the flicker noise in the regenerative and coupling transistors is also figured out. The phase noise contributions from the thermal noise and the flicker noise are verified by SpectreRF simulations.

  • Active Q Factor Analysis for Non-uniform Microstrip Stub Colpitts FET Oscillators

    Tuya WUREN  Takashi OHIRA  

     
    PAPER

      Vol:
    E94-A No:2
      Page(s):
    583-591

    This paper presents Q factor analysis for FET oscillators employing distributed-constant elements. We replace the inductor of a lumped constant Colpitts circuit by a shorted microstrip transmission line for high frequency applications. Involving the FET's transconductance and the transmission line's loss due to both conducting metal and dielectric substrate, we deduce the Q factor formula for the entire circuit in the steady oscillation state. We compared the computed results from the oscillator employing an uniform shorted microstrip line with that of the original LC oscillator. For obtaining even higher Q factor, we modify the shape of transmission line into nonuniform, i.e., step-, tapered-, and partially-tapered stubs. Non-uniformity causes some complexity in the impedance analysis. We exploit a piecewise uniform approximation for tapered part of the microstrip stub, and then involve the asymptotic expressions obtained from both stub's impedance and its frequency derivatives into the active Q factor formula. Applying these formulations, we calculate out the value of capacitance for tuning, the necessary FET's transconductance and achievable active Q factor, and then finally explore oscillator performances with a microstrip stub in different shapes and sizes.

1561-1580hit(4570hit)