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[Keyword] EMP(607hit)

321-340hit(607hit)

  • Spectroscopic Temperature Measurement of Breaking Arcs Near Cathode and Anode Surfaces of Copper Contacts

    Naoki MORIYAMA  Junya SEKIKAWA  Takayoshi KUBONO  

     
    PAPER-Arc Discharge & Related Phenomena

      Vol:
    E89-C No:8
      Page(s):
    1141-1146

    Breaking arcs are generated between a pair of Cu electrical contacts in a DC 42 V/10.5 A circuit, and the arc voltage, the arc current and the time-resolved arc spectral intensities near contact surfaces are simultaneously measured. The arc temperature is calculated from some spectral intensities emitted from Cu neutral atoms using the Boltzmann plot method. The arc temperatures near the cathode and anode surfaces are measured, and the following experimental results were obtained. (1) Time evolutions of the spectral intensities and the calculated arc temperature have similar characteristics. (2) The arc temperature near the anode surface is higher than that near the cathode surface, and the temperature fluctuation near the anode surface is larger than that near the cathode. (3) Just before arc extinction, the arc temperature near the cathode surface is almost constant for many breaking operations but the arc temperature near the anode surface varies.

  • A Visual Inspection System Based on Trinarized Broad-Edge and Gray-Scale Hybrid Matching

    Haruhisa OKUDA  Manabu HASHIMOTO  Miwako HIROOKA  Kazuhiko SUMI  

     
    PAPER-Image Inspection

      Vol:
    E89-D No:7
      Page(s):
    2068-2075

    In the field of industrial manufacturing, visual pattern inspection is an important task to prevent the inclusion of incorrect parts. There have been demands for such methods able to handle factors caused by positional and rotational alignment, and illumination changes. In this paper, we propose a discrimination method called Trinarized broad-edge and Gray-scale Hybrid Matching (TGHM). The method is highly reliable due to gray-scale cross correlation which has a high pattern discrimination efficiency, with high-speed position and rotation alignment using the characteristics of trinarized broad-edge representation which has high data compressibility and illumination-resistant variability. In an example in which the method is applied to mis-collation inspection equipment of a bookbinding machine, it is confirmed that the processing speed is 24,000 sheets/hour, the error detection rate is 100.0%, and the mis-alarm rate is less than 0.002%, and it is verified that the method is practical.

  • Self-Starting Pulse Generation from Cooled Erbium-Doped Fiber Ring Laser

    Kazuhiko SUMIMURA  Hidetsugu YOSHIDA  Hisanori FUJITA  Masahiro NAKATSUKA  Minoru YOSHIDA  

     
    LETTER-Lasers, Quantum Electronics

      Vol:
    E89-C No:7
      Page(s):
    1106-1107

    A self-starting pulse laser with an erbium-doped fiber cooled at liquid-nitrogen temperature was demonstrated. The self-starting-pulse fiber-ring laser can produce an approximately 1 ns pulse train without the need for devices for polarization control and compensation of birefringence.

  • Relationship among Complexities of Individual Sequences over Countable Alphabet

    Shigeaki KUZUOKA  Tomohiko UYEMATSU  

     
    PAPER-Information Theory

      Vol:
    E89-A No:7
      Page(s):
    2047-2055

    This paper investigates some relations among four complexities of sequence over countably infinite alphabet, and shows that two kinds of empirical entropies and the self-entropy rate regarding a Markov source are asymptotically equal and lower bounded by the maximum number of phrases in distinct parsing of the sequence. Some connections with source coding theorems are also investigated.

  • Removal of Adherent Waterdrops from Images Acquired with a Stereo Camera System

    Yuu TANAKA  Atsushi YAMASHITA  Toru KANEKO  Kenjiro T. MIURA  

     
    PAPER-Stereo and Multiple View Analysis

      Vol:
    E89-D No:7
      Page(s):
    2021-2027

    In this paper, we propose a new method that can remove view-disturbing noises from stereo images. One of the thorny problems in outdoor surveillance by a camera is that adherent noises such as waterdrops on the protecting glass surface lens disturb the view from the camera. Therefore, we propose a method for removing adherent noises from stereo images taken with a stereo camera system. Our method is based on the stereo measurement and utilizes disparities between stereo image pair. Positions of noises in images can be detected by comparing disparities measured from stereo images with the distance between the stereo camera system and the glass surface. True disparities of image regions hidden by noises can be estimated from the property that disparities are generally similar with those around noises. Finally, we can remove noises from images by replacing the above regions with textures of corresponding image regions obtained by the disparity referring. Experimental results show the effectiveness of the proposed method.

  • Temperature and Illumination Dependence of AlGaN/GaN HFET Threshold Voltage

    Masaya OKADA  Ryohei TAKAKI  Daigo KIKUTA  Jin-Ping AO  Yasuo OHNO  

     
    PAPER-GaN-Based Devices

      Vol:
    E89-C No:7
      Page(s):
    1042-1046

    This investigation of the temperature and illumination effects on the AlGaN/GaN HFET threshold voltage shows that it shifts about -1 V under incandescent lamp or blue LED illumination, while almost no shift takes place under red LED illumination. The temperature coefficient for the threshold voltage shift is +3.44 mV/deg under the illuminations and +0.28 mV/deg in darkness. The threshold voltage variation can be attributed to a virtual back-gate effect caused by light-generated buffer layer potential variations. The expressions for the potential variation are derived using Shockley-Read-Hall (SRH) statistics and the Maxwell-Boltzmann distribution for the carriers and deep traps in the buffer layer. The expressions indicate that large photoresponses will occur when the electron concentration in the buffer layer is extremely small, that is, highly resistive. In semi-insulating substrates, the substrate potential varies so as to keep the trap occupation function constant. The sign and the magnitude of the threshold voltage variation are explained by the shift of the pinning energy calculated from the Fermi-Dirac distribution function.

  • Temporal Error Concealment for H.264 Video Based on Adaptive Block-Size Pixel Replacement

    Donghyung KIM  Jongho KIM  Jechang JEONG  

     
    LETTER-Multimedia Systems for Communications

      Vol:
    E89-B No:7
      Page(s):
    2111-2114

    The H.264 standard allows each macroblock to have up to sixteen motion vectors, four reference frames, and a macroblock mode. Exploiting this feature, we present an efficient temporal error concealment algorithm for H.264-coded video. The proposed method turns out to show good performance compared with conventional approaches.

  • Video Synthesis with High Spatio-Temporal Resolution Using Motion Compensation and Spectral Fusion

    Kiyotaka WATANABE  Yoshio IWAI  Hajime NAGAHARA  Masahiko YACHIDA  Toshiya SUZUKI  

     
    PAPER-Video Generation

      Vol:
    E89-D No:7
      Page(s):
    2186-2196

    We propose a novel strategy to obtain a high spatio-temporal resolution video. To this end, we introduce a dual sensor camera that can capture two video sequences with the same field of view simultaneously. These sequences record high resolution with low frame rate and low resolution with high frame rate. This paper presents an algorithm to synthesize a high spatio-temporal resolution video from these two video sequences by using motion compensation and spectral fusion. We confirm that the proposed method improves the resolution and frame rate of the synthesized video.

  • A Low Loss Multi-Layer Dielectric Waveguide Filter for 60-GHz System-on-Package Applications

    Dong Yun JUNG  Won Il CHANG  Ji Hoon KIM  Chul Soon PARK  

     
    LETTER

      Vol:
    E89-A No:6
      Page(s):
    1690-1691

    For V-band applications, this paper presents a fully embedded multi-layer dielectric waveguide filter (DWGF) with very low insertion loss and small size, which does not need any more assemblies such as flip-chip bonding and bond wires. The top and bottom plane are grounded, and therefore, although we make a metal housing, there will be no resonance occurrences. Especially, the proposed structure is very suitable for MMICs interconnection because the in/output pads consist of conductor backed co-planar waveguide (CBCPW). The filter is formed incorporating metallized through holes in low temperature co-fired ceramic (LTCC) substrates with relative dielectric constant of 7.05. The total volume of the filter including transitions is 4.5 mm2.65 mm0.4 mm. A fabricated DWGF with four transitions shows an insertion loss and a return loss of 2.95 dB and less than 15 dB at the center frequency of 62.17 GHz, respectively. According to the authors' knowledge, the proposed filter shows the lowest insertion loss among the embedded multi-layer millimeter-wave filters ever reported for 60 GHz applications.

  • Analysis on Empathy-Inducing Effect Brought by Haiku

    Masami SUZUKI  Yuichi KOBAYASHI  Takahiro NAKAI  Kaori YOSHIDA  

     
    PAPER-Language

      Vol:
    E89-D No:6
      Page(s):
    1860-1867

    In this paper, we discuss the issue of empathy-inducing effect brought by Japanese Haiku, regarded as the world-shortest poetry. Its condensed form of word combination sometimes arouses deep impression and empathy in readers. Its possibilities as communication media would be enhanced in multimedia contexts, when considering educational purpose or cross-cultural interchanges. An experimental result is shown for evaluating multimedia effect on combined presentation of a CG drawing and its associated haiku in English. We confirmed that various aspects of visual impression and empathy were sometimes enhanced with certain haiku text as linguistic stimuli, compared with the condition of viewing a CG drawing only. The reason of raised empathy was analyzed from the various aspects of the content provided by the associated haiku text complementary for the drawing. Moreover, we examined the effects of poetic styles on subjects' empathy, using Japanese prose and conventional haiku style (5-7-5 syllabic rhyme), both of them were translated from the same haiku in English.

  • Novel Fiber-Optic Distributed Strain and Temperature Sensor with Very High Resolution

    Yahei KOYAMADA  Yousuke EDA  Souichi HIROSE  Shinki NAKAMURA  Kazuo HOGARI  

     
    LETTER-Sensing

      Vol:
    E89-B No:5
      Page(s):
    1722-1725

    A novel technique is proposed for measuring the distributed strain and temperature in a fiber with a very high resolution. This technique makes use of the jagged appearance of Rayleigh backscatter traces from a single-mode fiber measured by using a coherent OTDR with a precisely frequency-controlled light source. Our preliminary experiment indicated the possibility of measuring temperature with a resolution of better than 0.01 and a spatial resolution of one meter. This temperature resolution is two orders of magnitude better than that provided by Brillouin-based distributed sensors.

  • Competitive Analysis of Multi-Queue Preemptive QoS Algorithms for General Priorities

    Toshiya ITOH  Noriyuki TAKAHASHI  

     
    PAPER

      Vol:
    E89-A No:5
      Page(s):
    1186-1197

    The recent burst growth of the Internet use overloads networking systems and degrades the quality of communications, e.g., bandwidth loss, packet drops, delay of responses, etc. To overcome such degradation of communication quality, the notion of Quality of Service (QoS) has received attention in practice. In general, QoS switches have several queues and each queue has several slots to store arriving packets. Since network traffic changes frequently, QoS switches need to control arriving packets to maximize the total priorities of transmitted packets, where the priorities are given by nonnegative values and correspond to the quality of service required to each packet. In this paper, we first derive the upper bounds for the competitive ratio of multi-queue preemptive QoS problem with priority between 1/α and 1, i.e., for any α ≥ 1, the algorithm TLH is (3-1/α)-competitive. This is a generalization of known results--for the case that packets have only priority 1 (α =1), the algorithm GREEDY (or TLH) is 2-competitive; for the case that packets have priorities between 0 and 1 (α = ∞), the algorithm TLH is 3-competitive. Then we consider the lower bounds for the competitive ratio of multi-queue preemptive QoS problem with priority between 0 and 1, and show that the competitive ratio of any multi-queue preemptive QoS algorithm is at least 1.514.

  • Separation of Mixed Audio Signals by Decomposing Hilbert Spectrum with Modified EMD

    Md. Khademul Islam MOLLA  Keikichi HIROSE  Nobuaki MINEMATSU  

     
    PAPER-Speech/Audio Processing

      Vol:
    E89-A No:3
      Page(s):
    727-734

    The Hilbert transformation together with empirical mode decomposition (EMD) produces Hilbert spectrum (HS) which is a fine-resolution time-frequency representation of any nonlinear and non-stationary signal. The EMD decomposes the mixture signal into some oscillatory components each one is called intrinsic mode function (IMF). Some modification of the conventional EMD is proposed here. The instantaneous frequency of every real valued IMF component is computed with Hilbert transformation. The HS is constructed by arranging the instantaneous frequency spectra of IMF components. The HS of the mixture signal is decomposed into subspaces corresponding to the component sources. The decomposition is performed by applying independent component analysis (ICA) and Kulback-Leibler divergence based K-means clustering on the selected number of bases derived from HS of the mixture. The time domain source signals are assembled by applying some post processing on the subspaces. We have produced experimental results using the proposed separation technique.

  • Generalization Performance of Subspace Bayes Approach in Linear Neural Networks

    Shinichi NAKAJIMA  Sumio WATANABE  

     
    PAPER-Algorithm Theory

      Vol:
    E89-D No:3
      Page(s):
    1128-1138

    In unidentifiable models, the Bayes estimation has the advantage of generalization performance over the maximum likelihood estimation. However, accurate approximation of the posterior distribution requires huge computational costs. In this paper, we consider an alternative approximation method, which we call a subspace Bayes approach. A subspace Bayes approach is an empirical Bayes approach where a part of the parameters are regarded as hyperparameters. Consequently, in some three-layer models, this approach requires much less computational costs than Markov chain Monte Carlo methods. We show that, in three-layer linear neural networks, a subspace Bayes approach is asymptotically equivalent to a positive-part James-Stein type shrinkage estimation, and theoretically clarify its generalization error and training error. We also discuss the domination over the maximum likelihood estimation and the relation to the variational Bayes approach.

  • Design of MIMO Communication Systems Using Tapped Delay Line Structure in Receiver Side

    Tetsuki TANIGUCHI  Hoang Huy PHAM  Nam Xuan TRAN  Yoshio KARASAWA  

     
    PAPER-Communications

      Vol:
    E89-A No:3
      Page(s):
    670-677

    This paper presents a simple method to determine weights of single carrier multiple input multiple output (MIMO) broadband communication systems adopting tapped delay line (TDL) structure in receiver side for the effective communication under frequency selective fading (FSF) environment. First, assuming the perfect knowledge of the channel matrix in both arrays, an iterative design method of transmitter and receiver weights is proposed. In this approach, both weights are determined alternately to maximize signal to noise plus interference ratio (SINR) by fixing the weight of one side while optimizing the other, and this operation is repeated until SINR converges. Next, considering the case of uninformed transmitter, maximum SINR design method of MIMO system is extended for space time block coding (STBC) scheme working under FSF. Through computer simulations, it is demonstrated that the proposed schemes achieves higher SINR than conventional method with delay-less structure, particularly for the fading with long duration.

  • Thermal Characteristics of Access Cables Composed of Newly Designed Coated Fibers

    Atsuya TAKAHASHI  

     
    PAPER-Optical Fiber for Communications

      Vol:
    E89-B No:3
      Page(s):
    709-714

    The changes in fiber strain and fiber loss with temperature are quantitatively evaluated for 0.5 mm UV-coated fiber and three kind of fiber-optic access cables, for dropping and indoor wiring, employing 0.5 mm UV-coated fiber. Measurements of the fiber strain and loss increase are conducted using a quasi-heterodyne interferometer method and a photon-counting optical-time-domain-reflectmeter, respectively, at 1.3 and 1.55 µ m. From the strain characteristics, the following observations are made: (a) In the temperature range from -40 to 20 the fiber strain followed the cable strain quite closely, thus maintaining a tight cable structure and (b) from 20 to 80, the fiber exhibited a lower strain than the cable strain. Furthermore, no loss increase due to temperature change was observed for the 0.5-mm diameter coated fiber and the three type of optical cables.

  • A Novel Compact HTS Interdigital Bandpass Filter Using CPW Quarter-Wavelength Resonators

    Zhewang MA  Tamio KAWAGUCHI  Yoshio KOBAYASHI  Daisuke KOIZUMI  Kei SATOH  Shoichi NARAHASHI  

     
    PAPER

      Vol:
    E89-C No:2
      Page(s):
    140-144

    A novel high temperature superconducting interdigital bandpass filter is proposed by using coplanar waveguide quarter-wavelength resonators. The CPW resonators are arranged in parallel, and consequently the filter becomes very compact. The filter is a 5-pole Chebyshev BPF with a midband frequency of 5.0 GHz and an equal-ripple fractional bandwidth of 3.2%. It is fabricated using a YBCO film deposited on an MgO substrate. The measured filtering characteristics agree well with EM simulations and show a low insertion loss in spite of the small size of the filter.

  • No Reference and Reduced Reference Video Quality Metrics for End to End QoS Monitoring

    Patrick LE CALLET  Christian VIARD-GAUDIN  Stephane PECHARD  Emilie CAILLAULT  

     
    PAPER

      Vol:
    E89-B No:2
      Page(s):
    289-296

    This paper describes an objective measurement method designed to assess the perceived quality for digital videos. The proposed approach can be used either in the context of a reduced reference quality assessment or in the more challenging situation where no reference is available. In that way, it can be deployed in a QoS monitoring strategy in order to control the end-user perceived quality. The originality of the approach relies on the very limited computation resources which are involved, such a system could be integrated quite easily in a real time application. It uses a convolutional neural network (CNN) that allows a continuous time scoring of the video. Experiments conducted on different MPEG-2 videos, with bit rates ranging from 2 to 6 Mbits/s, show the effectiveness of the proposed approach. More specifically, a linear correlation criterion, between objective and subjective scoring, ranging from 0.90 up to 0.95 has been obtained on a set of typical TV videos in the case of a reduced reference assessment. Without any reference to the original video, the correlation criteria remains quite satisfying since it still lies between 0.85 and 0.90, which is quite high with respect to the difficulty of the task, and equivalent and more in some cases than the traditional PSNR, which is a full reference measurement.

  • Waveguide-Type SIS Receiver Using All-NbN Technique

    Masanori TAKEDA  Yoshinori UZAWA  Akira KAWAKAMI  Zhen WANG  

     
    PAPER

      Vol:
    E89-C No:2
      Page(s):
    163-169

    This paper describes the first experimental results for a waveguide-type all-NbN superconductor-insulator-superconductor (SIS) heterodyne mixer on an MgO substrate designed to operate over the gap frequency of Nb. The mixer consists of an NbN/MgO/NbN junction, which has a length of one wavelength at 880 GHz as a tuning circuit, an NbN/MgO/NbN microstrip as a λ/4 impedance transformer, and an RF choke filter. The mixer chip was designed using a high-frequency-structure simulator. Its return-loss and embedding-impedance characteristics were examined using a 180-times-scaled mixer model. By optimizing the cutting and polishing processes for the MgO substrate, we were able to fabricate the mixer chip with an accuracy of less than 5 µm. We succeeded in mounting the chip on a mixer block and in estimating the receiver noise temperature. The uncorrected minimum double-sideband receiver noise temperature was 740 K at 824 GHz. A comparison of the receiver noise temperature in a quasi-optical SIS mixer fabricated on the same wafer as the waveguide mixer showed that input noise was the major contributor to receiver noise in the waveguide mixer.

  • A 385-500 GHz Low Noise Superconductor-Insulator- Superconductor Mixer for ALMA Band 8

    Wenlei SHAN  Shinichiro ASAYAMA  Mamoru KAMIKURA  Takashi NOGUCHI  Shengcai SHI  Yutaro SEKIMOTO  

     
    PAPER

      Vol:
    E89-C No:2
      Page(s):
    170-176

    We report on the design and experimental results of a fix-tuned Superconductor-Insulator-Superconductor (SIS) mixer for Atacama Large Millimeter/submillimeter Array (ALMA) band 8 (385-500 GHz) receivers. Nb-based SIS junctions of a current density of 10 kA/cm2 and one micrometer size (fabricated with a two-step lift-off process) are employed to accomplish the ALMA receiver specification, which requires wide frequency coverage as well as low noise temperature. A parallel-connected twin-junction (PCTJ) is designed to resonate at the band center to tune out the junction geometric capacitance. A waveguide-microstrip probe is optimized to have nearly frequency-independent impedance at the probe's feed point, thereby making it easy to match the low-impedance PCTJ over a wide frequency band. The RF embedding impedance is retrieved by fitting the measured pumped I-V curves to confirm good matching between PCTJ and signal source. We demonstrate here a minimum double-sideband receiver noise temperature of 3 times of quantum limits for an intermediate-frequency range of 4-8 GHz. The mixers were measured in band 8 cartridge with a sideband separation scheme. Single-sideband receiver noise below ALMA specification was achieved over the whole band.

321-340hit(607hit)