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[Keyword] Q(6809hit)

4061-4080hit(6809hit)

  • Optical Manipulation of Nano Materials under Quantum Mechanical Resonance Conditions

    Takuya IIDA  Hajime ISHIHARA  

     
    PAPER

      Vol:
    E88-C No:9
      Page(s):
    1809-1816

    We make a theoretical study about the laser-induced radiation force exerted on nano materials under a quantum mechanical resonance condition of electronic systems [1] confined in them. In our recent study, we have clarified that the remarkable effects of the electronic resonance appear in the radiation force on the small object whose size is much smaller than the light wavelength; (A) the acceleration on the object gets larger as the size decreases, (B) the peaks with less heat appear in the force spectra even under the resonance condition, (C) the peak position sensitively varies with the nanoscale-size changes. These are useful for the optical manipulation to precisely control the mechanical motions of nano materials. In this paper, toward the experiment to verify the above results, we discuss the dependence of the mechanical motion of nano objects on the width of the incident laser light, and on the diffusion and friction effects assuming that they are floating in the superfluid helium-4 with the cryogenic condition where the electronic resonance effects become conspicuous. The results of calculations show that the particular nano objects, whose resonance energy corresponds to the center frequency of incident laser, can move away from others over macroscopic distance beyond diffusion length. This means that we can observe the distribution of sizes and qualities of nano objects as a macroscopic spatial distribution of them if we prepare appropriate conditions of incident light. We call this new technique 'Nano Optical Chromatography (NOC).'

  • Knowledge Circulation Framework for Flexible Multimedia Communication Services

    Shintaro IMAI  Takuo SUGANUMA  Norio SHIRATORI  

     
    PAPER

      Vol:
    E88-D No:9
      Page(s):
    2059-2066

    We present a design of knowledge circulation framework for quality of service (QoS) control of multimedia communication service (MCS). This framework aims to realizing user oriented and resource aware MCS by enabling effective placement of QoS control knowledge on the network. In this paper, we propose a conceptual design of the framework with knowledge-based multiagent system. In this framework, QoS control knowledge is actively circulated by getting on the agents. We implement a prototype of real-time bidirectional MCS (videoconference system) using this framework, and show initial experiment results using it to evaluate the effectiveness of the framework.

  • Supporting User Needs in a Network: A New Queue Management Technique

    Yan BAI  Mabo Rober ITO  

     
    LETTER-Network

      Vol:
    E88-B No:8
      Page(s):
    3458-3461

    Traditional network-level Quality of Service (QoS) techniques are efficient from a network perspective, but they have not provided end-to-end QoS that is satisfactory to users. In this letter, a Coordinated Packet Discard scheme for the distribution of end-to-end QoS requirements into local loss constraints, as well as provision of local loss assurance is proposed. Experiments demonstrate its advantages on increasing QoS-satisfied user ratio and improving network efficiency.

  • Adaptation Policies for Web Server Intrusion-Tolerant System

    Eul Gyu IM  Hoh Peter IN  Dae-Sik CHOI  Yong Ho SONG  

     
    LETTER-Internet

      Vol:
    E88-B No:8
      Page(s):
    3462-3465

    The emergence of intelligent and sophisticated attack techniques makes web services more vulnerable than ever which are becoming an important business tool in e-commerce. Many techniques have been proposed to remove the security vulnerabilities, yet have limitations. This paper proposes an adaptive mechanism for a web-server intrusion-tolerant system (WITS) to prevent unknown patterns of attacks by adapting known attack patterns. SYN flooding attacks and their adaptive defense mechanisms are simulated as a case study to evaluate the performance of the proposed adaptation mechanism.

  • A Compact Design of W-Band High-Pass Waveguide Filter Using Genetic Algorithms and Full-Wave Finite Element Analysis

    An-Shyi LIU  Ruey-Beei WU  Yi-Cheng LIN  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E88-C No:8
      Page(s):
    1764-1771

    This paper proposes an efficient two-phase optimization approach for a compact W-band double-plane stepped rectangular waveguide filter design, which combines genetic algorithms (GAs) with the simplified transmission-line model and full-wave analysis. Being more efficient and robust than the gradient-based method, the approach can lead to a compact waveguide filter design. Numerical results show that the resultant waveguide filter design with 4 sections (total length 19.6 mm) is sufficient to meet the design goal and provides comparable performance to that with 8 sections (total length 35.6 mm) by the Chebyshev synthesis approach. Based on the present approach, nineteen compact high-pass waveguide filters have been implemented and measured at the W-band with satisfactory performance.

  • Short-Term QoS Deficit Round Robin: An Efficient Scheduling Scheme for E-PON Systems

    Myoung-Hun KIM  Hong-Shik PARK  

     
    PAPER-Switching for Communications

      Vol:
    E88-B No:8
      Page(s):
    3321-3328

    In this paper, a design alternative for guaranteeing short-term QoS in the E-PON (Ethernet-Passive Optical Network) OLT (Optical Line Terminal) node is studied. A scheduling algorithm called Short-term QoS Deficit Round Robin (SQ-DRR) is proposed to guarantee tunable deterministic QoS constraints for multimedia applications over E-PON. The major appealing aspect of the scheduler is that it guarantees delay constraint for short-term aggregate burst traffic violating pre-contracted descriptors at the same time without loosing long-term fairness. We then evaluate the scheduler performance with and without admission control scheme under non-stationary long-range dependence (LRD) traffic. The simulation results indicate that the SQ-DRR performs well in dynamic burst traffic conditions.

  • Fundamental Characteristics of Stationary Lithium-Ion Secondary Cells and a Cell-Voltage-Equalizing Circuit

    Toshio MATSUSHIMA  Shinya TAKAGI  Seiichi MUROYAMA  Toshio HORIE  

     
    PAPER-Energy in Electronics Communications

      Vol:
    E88-B No:8
      Page(s):
    3436-3442

    This paper describes the characteristics of lithium-ion cells developed for stationary use, as in the case of stand-by sources in power systems. The effect of a cell-voltage-equalizing circuit developed for batteries of cells is also demonstrated. The tested lithium-ion cells were suitable to be charged by the constant-current, constant-voltage (CCCV) method and could be charged efficiently over a wide range of temperatures. They also showed good discharge performance with little dependence on the discharge current and temperature. Total capacity reduction of over 60% can be expected in batteries of lithium-ion cells. The cell-voltage-equalizing circuit was shown to be useful and necessary for batteries of lithium-ion cells in order to suppress deviations in the cell voltage and capacity loss.

  • An Enhanced Scalable Probe-Based Multicast Admission Control Scheme

    Zongkai YANG  Chunhui LE  Jianhua HE  Chun Tung CHOU  Wei LIU  

     
    LETTER-Internet

      Vol:
    E88-B No:8
      Page(s):
    3466-3470

    To guarantee QoS for multicast transmission, admission control for multicast sessions is expected. Probe-based multicast admission control (PBMAC) scheme is a scalable and simple approach. However, PBMAC suffers from the subsequent request problem which can significantly reduce the maximum number of multicast sessions that a network can admit. In this letter, we describe the subsequent request problem and propose an enhanced PBMAC scheme to solve this problem. The enhanced scheme makes use of complementary probing and remarking which require only minor modification to the original scheme. By using a fluid-based analytical model, we are able to prove that the enhanced scheme can always admit a higher number of multicast sessions. Furthermore, we present validation of the analytical model using packet based simulation.

  • Performance Analysis of Asynchronous FFH-MA Systems with a Linear-Combining Receiver in Rayleigh Fading

    Jeungmin JOO  Hyunduk KANG  Kanghee KIM  Kiseon KIM  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E88-B No:8
      Page(s):
    3475-3479

    The performance of asynchronous fast frequency hopping-multiple access (AFFH-MA) systems with multiple hops per bit is investigated with a linear-combining receiver in Rayleigh fading. We present an accurate approximation method for evaluating the error probability by using the characteristic function, Taylor series, and Gauss-Chebyshev quadrature rule. We will show that the proposed method provides an accurate approximation, compared with a simple Gaussian approximation. The validity of proposed analytic works is verified through Monte Carlo simulations.

  • General Method to Construct LS Codes by Complete Complementary Sequences

    Chao ZHANG  Xiaokang LIN  Shigeki YAMADA  Mitsutoshi HATORI  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E88-B No:8
      Page(s):
    3484-3487

    Large Area Synchronized (LAS)-CDMA, actually composed of LA codes and pulse compressing LS codes, has been proposed as a most promising scheme in 3G and 4G wireless communications. LS codes are famous for the Zero Correlation Zone (ZCZ) in the auto-correlation and cross-correlation functions, which endows the codes with the capability to perfectly reduce the Multiple Access Interference (MAI) and Inter Symbol Interference (ISI) if the maximum transmission delay is less than the length of ZCZ. In this letter, we provide a general and systematic method to construct LS codes from the set of complete complementary sequences. Our method is much more general than the ordinary LS construction method revealed previously.

  • Relationship between Length and Diameter of Contact Bridge Formed under Thermal Equilibrium Condition

    Hiroyuki ISHIDA  Masanari TANIGUCHI  Hideaki SONE  Hiroshi INOUE  Tasuku TAKAGI  

     
    PAPER-Contact Phenomena

      Vol:
    E88-C No:8
      Page(s):
    1566-1572

    From the authors' investigations on the initial instantaneous phenomena in breaking contacts, we have found the two types of bridge, i.e. one is a brightened (luminous) bridge and another one is a dark (non-luminous) one. This paper discusses on the dark bridge formed between contacts when the separation speed is very small. The following items are mentioned in this paper: a) bridge model and theory on the relationship between bridge length and diameter. b) thermal flow from bridge to its vicinity, c) deduction of a thermal equilibrium condition from the calculation of thermal flow time constant. d) experimental works, e) discussions and f) conclusions. In conclusion, we see the coincidence of the tendency of the theory and experiment carried out on the relationship between bridge diameter and length.

  • An Ultra-Small Double-Surface Electrode RFID Chip

    Mitsuo USAMI  

     
    INVITED PAPER

      Vol:
    E88-C No:8
      Page(s):
    1711-1715

    An ultra-small (0.3-mm0.3-mm0.06-mm) radio frequency identification chip called the µ-chip has been developed for use in a wide range of individual recognition applications. The chip is designed to be thin enough to be applied to paper and paper-like media that are widely used in retailing to create certificates with monetary value, as well as to token-type devices. The µ-chip has been designed and fabricated using 0.18-µm standard CMOS technology. This ultra-small RFID chip also has a low-cost oriented device structure of a double-surface electrode to simplify the process of connecting the antenna and chip. The measured characteristics of the prototype chip are presented, demonstrating the capability of the new chip as an RFID device.

  • High Speed Electronic Connectors: A Review of Electrical Contact Properties

    Roland S. TIMSIT  

     
    INVITED PAPER

      Vol:
    E88-C No:8
      Page(s):
    1532-1545

    At frequencies in the GHz range, an electrical connector must be considered as part of an electromagnetic transmission line. This paper reviews the effect of signal frequency on constriction resistance, interfacial capacitance and contact inductance at an electrical interface in a high speed connector. The deleterious effects of contact degradation at pin-receptacle junctions on transmitted signal integrity, are addressed. For frequencies in the GHz range, an electrical interface becomes capacitively coupled if contact resistance increases sufficiently. Contact deterioration may also lead to the generation of parasitic third-order harmonics that contribute to loss of signal integrity.

  • Radiated Electromagnetic Field Immunity Test Method for Wireless LAN Using Opened Parallel Wired Cell

    Masamitsu TOKUDA  Masayuki KITORA  Yasuo HONMA  Kouhei ICHIKAWA  

     
    PAPER-Communications

      Vol:
    E88-B No:8
      Page(s):
    3229-3234

    We study radiated RF (radio-frequency) electromagnetic field immunity test system for wireless LAN system by using opened PW (Parallel Wired) cell, in which metal cover is removed. Leakage electric field at distance of 160 cm from the opened PW cell decreases until 30 dB, and then does not affect to operation of the AP (Access Point) composed of the wireless LAN system that communicates EUT (Equipment Under Test) installed in the PW cell. NSA (Normalized Site Attenuation) between EUT and AP changes only several dB by inserting the PW cell, and then it can be concluded that the effect of PW cell for radio wave property of wireless communication system is negligible small. In addition, we try to measure dependencies of impressing level of disturbance wave on a throughput of wireless LAN systems IEEE802.11b and IEEE802.11g. As a result, it is confirmed that the radiated RF electromagnetic field immunity test system for wireless LAN system can be composed by using the opened PW cell without affecting from impressing disturbance wave.

  • Electromagnetic and Thermal Dosimetry of a Cylindrical Waveguide-Type in vitro Exposure Apparatus

    Tomohide SONODA  Rui TOKUNAGA  Koichi SETO  Yukihisa SUZUKI  Kanako WAKE  Soichi WATANABE  Masao TAKI  

     
    PAPER-Biological Effects

      Vol:
    E88-B No:8
      Page(s):
    3287-3293

    In this paper, dosimetry of an in vitro exposure apparatus based on a cylindrical waveguide is performed. The SAR distributions are first obtained numerically by using FDTD method. The thermal fields in the medium are then estimated by numerical calculations of the equation of heat conduction. The maximum temperature rise for 17.9 W/kg average SAR during 3000 s exposure is about 2 on the bottom of the medium where cells are located. The thermal distribution is relatively uniform near the center of the dish and the temperature in this region is around 38.7. The results of the numerical calculation are experimentally supported. The results provide the electromagnetic and thermal characteristics of the exposure apparatus, which will define the exposure conditions of the planned experiments using this apparatus.

  • Optimal Design of Complex Two-Channel IIR QMF Banks with Equiripple Response

    Ju-Hong LEE  Yuan-Hau YANG  

     
    PAPER-Digital Signal Processing

      Vol:
    E88-A No:8
      Page(s):
    2143-2153

    The optimal design of complex infinite impulse response (IIR) two-channel quadrature mirror filter (QMF) banks with equiripple frequency response is considered. The design problem is appropriately formulated to result in a simple optimization problem. Therefore, based on a variant of Karmarkar's algorithm, we can efficiently solve the optimization problem through a frequency sampling and iterative approximation method to find the complex coefficients for the IIR QMFs. The effectiveness of the proposed technique is to form an appropriate Chebyshev approximation of a desired response and then find its solution from a linear subspace in several iterations. Finally, simulation results are presented for illustration and comparison.

  • Human Body Impedance for Contact Current Measurement in Japan

    Yoshitsugu KAMIMURA  Katsuo KOMORI  Masahiro SHOJI  Yoshifumi YAMADA  Soichi WATANABE  Yukio YAMANAKA  

     
    PAPER-Biological Effects

      Vol:
    E88-B No:8
      Page(s):
    3263-3268

    The radio-frequency protection guideline of Japan recommend the limits of contact current for contact hazard due to an ungrounded metallic object under an electromagnetic field in the frequency range from 10 kHz to 15 MHz. To arrange the standard measurement methods of contact current in Japan, the contact body impedance for the Japanese in the frequency range from 75 kHz to 15 MHz is obtained, and the simplified equivalent circuit is determined using nonlinear least squares method. In addition, the human body impedance is obtained from numerical simulation using the impedance method and voxel human model, and compared it with measured one.

  • Evaluation of Damage in DNA Molecules Caused by Very-Low-Frequency Magnetic Fields Using Bacterial Cells

    Akira HAGA  Yoshiaki KUMAGAI  Hidetoshi MATSUKI  Ginro ENDO  Akira IGARASHI  Koichiro KOBAYASHI  

     
    PAPER-Biological Effects

      Vol:
    E88-B No:8
      Page(s):
    3249-3256

    The effect of intermediate frequency magnetic fields or, very-low-frequency magnetic fields (VLFMF) on living biological cells was investigated using a highly sensitive mutagenesis assay method. A bacterial gene expression system for mutation repair (umu system) was used for the sensitive evaluation of damage in DNA molecules. Salmonella typhimurium TA1535 (pSK1002) were exposed to VLFMF (20 kHz and 600 µT) in a specially designed magnetic field loading chamber. The experiment results showed the possibility of applying the umu assay for sensitive and effective evaluation of damage in DNA molecules. No effects from exposure to 20 kHz and 600 µT magnetic fields in terms of damage in DNA molecules were observed.

  • Extraction of Desired Spectra Using ICA Regression with DOAS

    Hyeon-Ho KIM  Sung-Hwan HAN  Hyeon-Deok BAE  

     
    LETTER-Measurement Technology

      Vol:
    E88-A No:8
      Page(s):
    2244-2246

    Recently, DOAS (differential optical absorption spectroscopy) has been used for nondestructive air monitoring, in which the LS (least squares) method is used to calculate trace gas concentrations due to its computational simplicity. This paper applies the ICA (independent component analysis) method to the DOAS system of air monitoring, since the LS method is insufficient to recover the desired spectra perfectly due to sparsity characteristic. If the sparsity of reference spectra in the DOAS system imposes the assumption of independence, the ICA algorithm can be used. The proposed method is used to regress the observed spectrum on the estimates of the reference spectra. The ICA algorithm can be seen as a preprocessing method where the ICs of the references are used as the input in the regression. The performance of the proposed method is evaluated in simulation studies using synthetic data.

  • An Experimental Equation for Dependence of Duration of Breaking Arcs on Supply Voltage with Constant Circuit Resistance

    Junya SEKIKAWA  Takayoshi KUBONO  

     
    PAPER-Arc Discharge & Related Phenomena

      Vol:
    E88-C No:8
      Page(s):
    1584-1589

    Arc duration of breaking arcs is investigated in order to obtain an experimental equation for the dependence of the arc duration on supply voltage in DC resistive circuit in air at atmospheric pressure. Materials of the contact pairs are Au, Ag, Cu, Ni, Pt and Pd. The interrupted current is ranging from 6 A to 10 A and the supply voltage is 30 V, 42 V and 54 V. Sato's experimental equation for the arc length is modified to obtain more appropriate experimental equation for our experimental results. The arc termination current It and minimum arc voltage Vm that are obtained with the experimental results are used as parameters of the experimental equation for each contact material. And characteristic coefficients C for each contact material in the experimental equation are obtained. As results, the experimental equation for each contact material well agrees with the experimental results. The experimental equation for several contact materials is presented.

4061-4080hit(6809hit)