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[Keyword] ROS(1068hit)

341-360hit(1068hit)

  • New Construction of Quaternary Sequences with Good Correlation Using Binary Sequences with Good Correlation

    Taehyung LIM  Jong-Seon NO  Habong CHUNG  

     
    PAPER-Coding Theory

      Vol:
    E94-A No:8
      Page(s):
    1701-1705

    In this paper, a new construction method of quaternary sequences of even period 2N having the ideal autocorrelation and balance properties is proposed. These quaternary sequences are constructed by applying the inverse Gray mapping to binary sequences of odd period N with the ideal autocorrelation. Autocorrelation distribution of the proposed quaternary sequences is derived. These sequences can be used to construct quaternary sequence families of even period 2N. Family size and the maximum absolute value of correlation spectrum of the proposed quaternary sequence families are also derived.

  • Cross-Layer Optimization for Multi-View Video Streaming Service over Wireless Broadband Internet

    Junghyun SON  Doug Young SUH  Gwang-Hoon PARK  Kyuheon KIM  

     
    PAPER-Multimedia Systems for Communications

      Vol:
    E94-B No:7
      Page(s):
    2104-2113

    This paper defines a Quality of Experience (QoE) parameter for multi-view video streaming service over Wireless Broadband Internet, and proposes cross-layer optimization (CLO) algorithm to maximize the QoE. The proposed CLO algorithm interacts with all layers from PHY layer to video layer. Under the time-varying wireless channel condition, it guarantees service continuity to the user by selecting frames to be transmitted. The CLO technique takes inter-view and the temporal significance of the multi-view video frames into consideration when deciding the Transmission Frame Set (TFS) and its Levels of FEC (LOF). Through simulation of the proposed technique, it is shown that the optimal quality of the multi-view video can be achieved even during hand-over, using the minimum amount of resources. Visual quality of multi-view video streams is improved by about 15.330.2%, especially up to 39.165% during the hand-over. Moreover, continuity of the most important view has been increased by 20.139.1% in comparison with conventional method.

  • Eigenmode Analysis of Propagation Constant for a Microstrip Line with Dummy Fills on a Si CMOS Substrate

    Yuya ONO  Takuichi HIRANO  Kenichi OKADA  Jiro HIROKAWA  Makoto ANDO  

     
    PAPER

      Vol:
    E94-C No:6
      Page(s):
    1008-1015

    In this paper we present eigenmode analysis of the propagation constant for a microstrip line with dummy fills on a Si CMOS substrate. The effect of dummy fills is not negligible, particularly in the millimeter-wave band, although it has been ignored below frequencies of a few GHz. The propagation constant of a microstrip line with a periodic structure on a Si CMOS substrate is analyzed by eigenmode analysis for one period of the line. The calculated propagation constant and characteristic impedance were compared with measured values for a chip fabricated by the 0.18 µm CMOS process. The agreement between the analysis and measurement was very good. The dependence of loss on the arrangement of dummy fills was also investigated by eigenmode analysis. It was found that the transmission loss becomes large when dummy fills are arranged at places where the electromagnetic field is strong.

  • A New Framework with FDPP-LX Crossover for Real-Coded Genetic Algorithm

    Zhi-Qiang CHEN  Rong-Long WANG  

     
    PAPER-Numerical Analysis and Optimization

      Vol:
    E94-A No:6
      Page(s):
    1417-1425

    This paper presents a new and robust framework for real-coded genetic algorithm, called real-code conditional genetic algorithm (rc-CGA). The most important characteristic of the proposed rc-CGA is the implicit self-adaptive feature of the crossover and mutation mechanism. Besides, a new crossover operator with laplace distribution following a few promising descent directions (FPDD-LX) is proposed for the rc-CGA. The proposed genetic algorithm (rc-CGA+FPDD-LX) is tested using 31 benchmark functions and compared with four existing algorithms. The simulation results show excellent performance of the proposed rc-CGA+FPDD-LX for continuous function optimization.

  • A Timed-Based Approach for Genetic Algorithm: Theory and Applications

    Amir MEHRAFSA  Alireza SOKHANDAN  Ghader KARIMIAN  

     
    PAPER-Biocybernetics, Neurocomputing

      Vol:
    E94-D No:6
      Page(s):
    1306-1320

    In this paper, a new algorithm called TGA is introduced which defines the concept of time more naturally for the first time. A parameter called TimeToLive is considered for each chromosome, which is a time duration in which it could participate in the process of the algorithm. This will lead to keeping the dynamism of algorithm in addition to maintaining its convergence sufficiently and stably. Thus, the TGA guarantees not to result in premature convergence or stagnation providing necessary convergence to achieve optimal answer. Moreover, the mutation operator is used more meaningfully in the TGA. Mutation probability has direct relation with parent similarity. This kind of mutation will decrease ineffective mating percent which does not make any improvement in offspring individuals and also it is more natural. Simulation results show that one run of the TGA is enough to reach the optimum answer and the TGA outperforms the standard genetic algorithm.

  • COLA: COmmon Layer Architecture for Adaptive Power Control and Access Technology Assignment in New Generation Networks

    John Paul TORREGOZA  Pham Ngoc THAI  Won Joo HWANG  Yun Sop HAN  Fumio TERAOKA  Martin ANDRE  Hiroaki HARAI  

     
    PAPER

      Vol:
    E94-B No:6
      Page(s):
    1526-1535

    Cognitive radio in network core devices, such as basestations, is being considered as a spectrum management solution for future society's communication demands. Aside from new resource allocation algorithms, efficient inter- and intra-protocol processing should be considered. In this paper, we propose an opportunistic cross layer architecture called COmmon Layer Architecture (COLA) for information exchange between arbitrary layers in New Generation Networks with network-oriented cognitive radio. COLA provides a means for faster information exchange between OSI layers by introducing abstraction at each layer and designing primitives for communication between each abstraction layer. Emulation and simulation results showed improvements, compared to conventional networks, in disrupted service (42% reduction), average delay (47% reduced) and packet drop ratio (22% reduced) in the scenario analyzed.

  • A Wideband Noise Cancelling Low Noise Amplifier for 3GPP LTE Standard

    Viet-Hoang LE  Hoai-Nam NGUYEN  Sun-a KIM  Seok-Kyun HAN  Sang-Gug LEE  

     
    BRIEF PAPER-Microwaves, Millimeter-Waves

      Vol:
    E94-C No:6
      Page(s):
    1127-1130

    This paper presents the design of a wideband low noise amplifier (LNA) for the 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) standard. The proposed LNA uses a common gate topology with a noise cancellation technique for wideband (0.7 to 2.7 GHz) and low noise operation. The capacitive cross coupling technique is adopted for the common gate amplifier. Consequently input matching is achieved with lower transconductance, thereby reducing the power consumption and noise contribution. The LNA is designed in a 0.18 µm process and the simulations show lower than -10 dB input return loss (S11), and 2.42.6 dB noise figure (NF) over the entire operating band (0.72.7 GHz) while drawing 9 mA from a 1.8 V supply.

  • High Transport Si/SiGe Heterostructures for CMOS Transistors with Orientation and Strain Enhanced Mobility Open Access

    Jungwoo OH  Jeff HUANG  Injo OK  Se-Hoon LEE  Paul D. KIRSCH  Raj JAMMY  Hi-Deok LEE  

     
    INVITED PAPER

      Vol:
    E94-C No:5
      Page(s):
    712-716

    We have demonstrated high mobility MOS transistors on high quality epitaxial SiGe films selectively grown on Si (100) substrates. The hole mobility enhancement afforded intrinsically by the SiGe channel (60%) is further increased by an optimized Si cap (40%) process, resulting in a combined ∼100% enhancement over Si channels. Surface orientation, channel direction, and uniaxial strain technologies for SiGe channels CMOS further enhance transistor performances. On a (110) surface, the hole mobility of SiGe pMOS is greater on a (110) surface than on a (100) surface. Both electron and hole mobility on SiGe (110) surfaces are further enhanced in a <110> channel direction with appropriate uniaxial channel strain. We finally address low drive current issue of Ge-based nMOSFET. The poor electron transport property is primarily attributed to the intrinsically low density of state and high conductivity effective masses. Results are supported by interface trap density (Dit) and specific contact resistivity (ρc).

  • Transition from Waveguide to Two Microstrip Lines with Slot Radiators in the Millimeter-Wave Band

    Kazuyuki SEO  Kunio SAKAKIBARA  Nobuyoshi KIKUMA  

     
    PAPER-Antennas and Antenna Measurement

      Vol:
    E94-B No:5
      Page(s):
    1184-1193

    Many kinds of microstrip array antennas have been developed in the millimeter-wave band. In order to avoid feeding loss and the decrease of antenna gain by beam shift due to frequency changes, center-fed array antennas are advantageous. In this case, the element spacing around the feeding circuit of the transition from the waveguide to two microstrip lines is larger than one wavelength. Therefore, the sidelobe level grows significantly. In order to suppress the sidelobe level, we propose transitions with slot radiators. Moreover, any polarization angles can be achieved by changing the slot angle. A wide variety from 1.5% to 70% of slot radiator coupling powers can be achieved. To investigate the performance of the proposed transition, 10, 22 and 30-element center-fed microstrip comb-line antennas with the proposed transition were developed at 76.5 GHz, and measured performance was evaluated in the millimeter-wave band.

  • A Non-snapback ESD Protection Clamp Circuit Using Isolated Parasitic Capacitance in a 0.35 µm Bipolar-CMOS-DMOS Process

    Jae-Young PARK  Dae-Woo KIM  Young-Sang SON  Jong-Kyu SONG  Chang-Soo JANG  Won-Young JUNG  

     
    PAPER

      Vol:
    E94-C No:5
      Page(s):
    796-801

    A novel NMOS Electrostatic Discharge (ESD) clamp circuit is proposed for a 0.35 µm Bipolar-CMOS-DMOS (BCD) process. The proposed ESD clamp has a non-snapback characteristic because of gate-coupled effect. This proposed ESD clamp circuit is developed without additional components made possible by replacing a capacitor with an isolated parasitic capacitor. The result of the proposed ESD clamp circuit is measured by 100 ns Transmission Line Pulse (TLP) system. From the measurement, it was observed that the proposed ESD clamp has approximately 40% lower triggering voltage compared to the conventional gate-grounded NMOS ESD clamp. This is achieved without degradation of the other ESD design key parameter. The proposed ESD clamp also has high robustness characteristics compared to the conventional RC-triggered NMOS ESD clamp circuit.

  • Compact Matrix-Switch-Based Hierarchical Optical Path Cross-Connect with Colorless Waveband Add/Drop Ratio Restriction

    Ryosuke HIRAKO  Kiyo ISHII  Hiroshi HASEGAWA  Ken-ichi SATO  Osamu MORIWAKI  

     
    PAPER

      Vol:
    E94-B No:4
      Page(s):
    918-927

    We propose a compact matrix-switch-based hierarchical optical cross-connect (HOXC) architecture that effectively handles the colorless waveband add/drop ratio restriction so as to realize switch scale reduction. In order to implement the colorless waveband add/drop function, we develop a wavelength MUX/DMUX that can be commonly used by different wavebands. We prove that the switch scale of the proposed HOXC is much smaller than that of conventional single-layer optical cross-connects (OXCs) and a typical HOXC. Furthermore, we introduce a prototype system based on the proposed architecture that utilizes integrated novel wavelength MUXs/DMUXs. Transmission experiments prove its technical feasibility.

  • Edge-Preserving Cross-Sharpening of Multi-Modal Images

    Yu QIU  Kiichi URAHAMA  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E94-D No:3
      Page(s):
    718-720

    We present a simple technique for enhancing multi-modal images. The unsharp masking (UM) is at first nonlinearized to prevent halos around large edges. This edge-preserving UM is then extended to cross-sharpening of multi-modal images where a component image is sharpened with the aid of more clear edges in another component image.

  • Bayesian Context Clustering Using Cross Validation for Speech Recognition

    Kei HASHIMOTO  Heiga ZEN  Yoshihiko NANKAKU  Akinobu LEE  Keiichi TOKUDA  

     
    PAPER-Speech and Hearing

      Vol:
    E94-D No:3
      Page(s):
    668-678

    This paper proposes Bayesian context clustering using cross validation for hidden Markov model (HMM) based speech recognition. The Bayesian approach is a statistical technique for estimating reliable predictive distributions by treating model parameters as random variables. The variational Bayesian method, which is widely used as an efficient approximation of the Bayesian approach, has been applied to HMM-based speech recognition, and it shows good performance. Moreover, the Bayesian approach can select an appropriate model structure while taking account of the amount of training data. Since prior distributions which represent prior information about model parameters affect estimation of the posterior distributions and selection of model structure (e.g., decision tree based context clustering), the determination of prior distributions is an important problem. However, it has not been thoroughly investigated in speech recognition, and the determination technique of prior distributions has not performed well. The proposed method can determine reliable prior distributions without any tuning parameters and select an appropriate model structure while taking account of the amount of training data. Continuous phoneme recognition experiments show that the proposed method achieved a higher performance than the conventional methods.

  • Dynamics Modeling and Induced Vibration Analysis of Momentum Wheel for Control Moment Gyros

    Jong-Oh PARK  Shi-Hwan OH  Ki-Lyuk YONG  Young-Do IM  

     
    LETTER-Noise and Vibration

      Vol:
    E94-A No:3
      Page(s):
    990-994

    Actuator-induced disturbances are among the most crucial factors in correct spacecraft attitude pointing and stability for fine attitude control problems. In order to develop a CMG as an actuator for fine controls, CMG-induced disturbances should be analyzed. Therefore, this paper aims to develop an analytic model that predicts the effect of disturbances to CMGs by assuming static and dynamic imbalances. The proposed analytical model with respect to the disturbances of a CMG is derived using the Lagrange energy method based on the small-signal assumption.

  • Accuracy in Permeability Measurement by a Combined Microstrip Line-Coaxial Conductor Method

    Keigo KANEMARU  Atsushi KURAMOTO  Tomohiko KANIE  Yuichi NORO  Takashi TAKEO  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E94-C No:3
      Page(s):
    327-333

    In this paper, accuracy or error in permeability measurement using a combined microstrip line-coaxial conductor method was investigated. The measurement circuit used in this study is composed of a microstrip line (MSL) circuit and a grounded metal pipe with a center conductor passing through it coaxially. A sample is placed between the metal pipe and the center conductor. We evaluated the measurement accuracy for this measurement arrangement with electromagnetic simulation for the case where there are gaps between the sample and the holder. As a result, it has been shown that the normalized errors for this method have similar gap size dependence to the conventional coaxial method, but are about 10 to 20 percent greater than the coaxial method. With a view to improving the measurement accuracy, a correction method for the error is also discussed.

  • 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.

  • Enhanced Distal Radius Segmentation in DXA Using Modified ASM

    Sihyoung LEE  Sunil CHO  Yong Man RO  

     
    PAPER-Biological Engineering

      Vol:
    E94-D No:2
      Page(s):
    363-370

    The active shape model (ASM) has been widely adopted by automated bone segmentation approaches for radiographic images. In radiographic images of the distal radius, multiple edges are often observed in the near vicinity of the bone, typically caused by the presence of thin soft tissue. The presence of multiple edges decreases the segmentation accuracy when segmenting the distal radius using ASM. In this paper, we propose an enhanced distal radius segmentation method that makes use of a modified version of ASM, reducing the number of segmentation errors. To mitigate segmentation errors, the proposed method emphasizes the presence of the bone edge and downplays the presence of a soft tissue edge by making use of Dual energy X-ray absorptiometry (DXA). To verify the effectiveness of the proposed segmentation method, experiments were performed with 30 distal radius patient images. For the images used, compared to ASM-based segmentation, the proposed method improves the segmentation accuracy with 47.4% (from 0.974 mm to 0.512 mm).

  • An Investigation on Crosstalk in Multi-Core Fibers by Introducing Random Fluctuation along Longitudinal Direction

    Katsuhiro TAKENAGA  Yoko ARAKAWA  Shoji TANIGAWA  Ning GUAN  Shoichiro MATSUO  Kunimasa SAITOH  Masanori KOSHIBA  

     
    PAPER

      Vol:
    E94-B No:2
      Page(s):
    409-416

    The length dependence of the crosstalk in multi-core fibers has been investigated by introducing random fluctuation along longitudinal direction. The power coupling coefficients in the coupled-power theory in heterogeneous multi-core fiber with seven cores were estimated based on consideration of the power coupling coefficients of the homogeneous multi-core fiber. The crosstalk can be quantitatively evaluated by employing coupled-power theory instead of coupled-mode theory.

  • 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.

  • Construction of Binary Array Set with Zero Correlation Zone Based on Interleaving Technique

    Yifeng TU  Pingzhi FAN  Li HAO  Xiyang LI  

     
    PAPER-Information Theory

      Vol:
    E94-A No:2
      Page(s):
    766-772

    Sequences with good correlation properties are of substantial interest in many applications. By interleaving a perfect array with shift sequences, a new method of constructing binary array set with zero correlation zone (ZCZ) is presented. The interleaving operation can be performed not only row-by-row but also column-by-column on the perfect array. The resultant ZCZ binary array set is optimal or almost optimal with respect to the theoretical bound. The new method provides a flexible choice for the rectangular ZCZ and the set size.

341-360hit(1068hit)