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13241-13260hit(20498hit)

  • An Algorithm for the Generation of Maximal-Period Sequences Based on One-Dimensional Chaos Maps with Finite Bits

    Daisaburo YOSHIOKA  Akio TSUNEDA  Takahiro INOUE  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1371-1376

    This paper deals with the method for generation of maximal-period sequences which are designed by properly quantizing the variable state of a class of one-dimensional piecewise-linear onto maps. We confirmed that the proposed method enables us to generate many maximal-period sequences from such maps including De-Bruijn cases.

  • Robust Watermarking Based on Time-spread Echo Method with Subband Decomposition

    Byeong-Seob KO  Ryouichi NISHIMURA  Yoiti SUZUKI  

     
    LETTER-Information Security

      Vol:
    E87-A No:6
      Page(s):
    1647-1650

    A robust watermarking scheme based on the time-spread echo method is proposed in this letter. The embedding process is achieved by subband decomposition of a host signal and by controlling the amount of distortion, i.e., power of watermark, of each subband according to the Signal to Mask Ratio (SMR) calculated from MPEG psychoacoustic model. The decoding performance and robustness of the proposed method were evaluated.

  • Density Attack to the Knapsack Cryptosystems with Enumerative Source Encoding

    Keiji OMURA  Keisuke TANAKA  

     
    PAPER-Information Security

      Vol:
    E87-A No:6
      Page(s):
    1564-1569

    We analyze the Lagarias-Odlyzko low-density attack precisely, and show that this low-density attack can be applied to the Chor-Rivest and the Okamoto-Tanaka-Uchiyama cryptosystemes, which are considered to be secure against the low-density attack. According to our analysis, these schemes turn out to be no longer secure against the low-density attack.

  • On the Use of Shanks Transformation to Accelerate Capacitance Extraction for Periodic Structures

    Ye LIU  Zheng-Fan LI  Mei XUE  Rui-Feng XUE  

     
    LETTER-Electromagnetic Theory

      Vol:
    E87-C No:6
      Page(s):
    1078-1081

    Integral equation method is used to compute three-dimension-structure capacitance in this paper. Since some multi-conductor structures present regular periodic property, the periodic cell is used to reduce the computational domain with adding appropriate magnetic and electric walls. The periodic Green's function in the integral equation method is represented in the form of infinite series with slow convergence. In this paper, Shanks transformation is used to accelerate the convergence. Numerical examples show that the proposed method is accurate with a much higher efficiency in capacitance extraction for 3-D periodic structures.

  • A Basic Study on Control Command Input Device Using Head Movement for FES System--Availability of Acceleration Sensors--

    Hiroki HIGA  Ikuo NAKAMURA  Nozomu HOSHIMIYA  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1441-1445

    As one of control command input methods for functional electrical stimulation (FES) system, using the head movements was considered in this paper. In order to detect the head movements, we designed a prototype control command input device using acceleration sensors and verified its validity in experiments. The experimental results showed that the head movements in the lateral flexion and in the flexion/extension were highly detected and separated by the acceleration sensors.

  • The Effects of the Timing of Commercial Breaks on the Loss of Attention

    Noriko NAGATA  Sanae H. WAKE  Mieko OHSUGA  Seiji INOKUCHI  

     
    LETTER

      Vol:
    E87-D No:6
      Page(s):
    1484-1487

    Commercial breaks are often placed at the climax of stories in recent TV programs in Japan, which may cause some serious effects on audiences, especially children, since this practice disturbs the concentrations. The experiment measured the psycho-physiological state of four children before and after commercials. The results showed that the next peak of attention is delayed by distracting the attention.

  • Design Optimization Methodology for On-Chip Spiral Inductors

    Kenichi OKADA  Hiroaki HOSHINO  Hidetoshi ONODERA  

     
    PAPER

      Vol:
    E87-C No:6
      Page(s):
    933-941

    This paper presents a methodology for optimizing the layout of on-chip spiral inductors using structural parameters and design frequency in a response surface method. The proposed method uses scattering parameters (S-parameter) to express inductor characteristics, and hence is independent of spiral geometries and equivalent circuit models. The procedure of inductor optimization is described, and a design example is presented.

  • All Digital DLL with Three Phase Tuning Stages

    Jin-Ho CHOI  Jin-Ku KANG  

     
    PAPER

      Vol:
    E87-A No:6
      Page(s):
    1305-1309

    This paper describes an all-digital DLL (Delay Locked Loop) circuit with a high phase resolution. The proposed architecture is based on three-stage phase tuning blocks for coarse, fine and ultra fine phase control. Each block has a phase detector, a phase selection block and a delay line, respectively. It was simulated in a 0.35 µm CMOS technology under 3.3 V power supply. The simulation result shows the maximum phase error can be reduced to 13-42 ps with the operating range of 250 MHz to 800 MHz.

  • AGSphere: Multiresolution Structure of Directional Relationship on Surface Parts

    HyungSeok KIM  Kwangyun WOHN  

     
    PAPER-Computer Graphics

      Vol:
    E87-D No:6
      Page(s):
    1537-1544

    We present a new method in multiresolution rendering of a complex object. Our method uses viewer-centered features including the silhouette in generating multiresolution model. Because the silhouette of an object depends on the position of the viewer, the silhouette has difficulties in real-time generation. We propose the AGSphere for real-time management of the silhouette. The AGSphere easily identifies silhouette parts and manages it in multiresolution manner. The primary applicable feature of the AGSphere is the silhouette from the viewer, but we can also use the AGSphere for other directional features like light silhouette. In this paper, we show experimental results for the silhouette either from the viewer or the light. The efficiency of the proposed method is compared with other methods. We also propose new texture map generation method to use with the multiresolution geometry. Generated texture map has valid mapping function for the multiresolution geometry minimizing texture distortions.

  • Low Cost Printed Omni-Directional Spiral-Mode Monopole Antenna for Wireless Applications

    I-Fong CHEN  

     
    LETTER-Antenna and Propagation

      Vol:
    E87-B No:6
      Page(s):
    1764-1766

    A low cost printed omni-directional spiral-mode mono-pole antenna for wireless communication applications has been designed. This antenna has an integrated open-stub to adjust impedance matching. The 10 dB bandwidth is 336 MHz that achieved 13.7 and radiating characteristics are presented.

  • Mixed Signal SoC Era

    Akira MATSUZAWA  

     
    INVITED PAPER

      Vol:
    E87-C No:6
      Page(s):
    867-877

    Application area of mixed signal technology is currently expanded to digital communication, networking, and digital storage systems from conventional digital audio and video systems. Digital consumer electronics are emerged and their markets are extremely increased. Rapid progress of integrated circuit technology has enabled a system level integration on a SoC. Thus mixed signal SoC becomes a majority in LSI industry. Almost all the analog functions should be realized by CMOS technology on SoC, yet some difficulties such as a low transconductance, a large mismatch voltage, and a large 1/f noise should be solved. CMOS device has been considered as a poor device for the analog use, however in reality, it has attained a remarkable progress for analog applications. CMOS device has a variety of circuit techniques to address its own issues and also has an analog performance that increases rapidly with technology scaling. The mixed signal SoC needs a new development strategy and design methodology that covers from system level to device level for addressing tough needs for a shorter development time, a lower cost, and a higher design quality. The optimizations over analog and digital and over system to device must be established for the development success. Difficulty of low voltage operation of further scaled CMOS in analog circuits will be the most serious issue. This results in the saturation of performance and increase of cost. The system level optimization over analog and digital, digital calibration and compensation, and the use of sigma-delta modulation method will give us the solution.

  • A Basic Study on Teammates' Mental Workload among Ship's Bridge Team

    Koji MURAI  Yuji HAYASHI  Seiji INOKUCHI  

     
    PAPER

      Vol:
    E87-D No:6
      Page(s):
    1477-1483

    Ship handling for leaving and entering port always carries out for a captain, deck officers and quartermasters and sometimes include a pilot. For navigational watch keeping at sea except for a narrow channel and under restricted visibility etc., the deck officer and quartermaster do it. They achieve safe and efficient navigational watch keeping with their teamwork at a ship's bridge. The importance of teamwork has been recognized in the shipping world, and its training and education methods are also thought over. However, their evaluation is not clear, because they are depended on the experience of the trainers. Therefore, we need to make an evaluation method of teamwork for education and training of the ship handling. In this paper, we define that ship's bridge teamwork is shown by 1) a change of mental workload level and 2) a change of mental workload for time. We challenge to evaluate teammates' mental workload in the ship's bridge with R-R interval of subjects' heart rate variability, and we evaluate their mental workloads with the following three steps. 1) To confirm the evaluation of the mental workload of a ship's navigator with R-R interval. 2) To evaluate teamwork with R-R interval in case of an oral presentation at meetings as pre-experiments. 3) To evaluate the teammates' mental workload among ship's bridge team in case of a leaving port. Their results showed that the method using R-R interval was sufficient for the evaluation of teamwork effects.

  • Performance Evaluation Method of Bit-Interleaved Turbo Trellis-Coded Modulation and Its Optimization

    Novianto FAJAR  Haruo OGIWARA  

     
    PAPER-Coding Theory

      Vol:
    E87-A No:6
      Page(s):
    1583-1590

    For an additive white Gaussian noise (AWGN) channel, a performance evaluation of parallel concatenated turbo trellis-coded modulation (turbo TCM) using bit-interleavers is reported. By obtaining weight distribution, the performance is evaluated by using a union bound method. Comparison between the result of evaluated performance and simulation results is shown, and the usefulness of the evaluated performance is shown. An optimum code and an optimum mapping are sought. The result of the optimum code with the optimum mapping is a new interleaver size N dependency which is proportional to N-3. It is better than the interleaver size dependency for Benedetto code with the natural mapping which is proportional to N-1. The reasons why these dependencies can happen are also discussed.

  • An Estimation Algorithm of Target Location and Scattered Waveforms for UWB Pulse Radar Systems

    Takuya SAKAMOTO  Toru SATO  

     
    PAPER-Sensing

      Vol:
    E87-B No:6
      Page(s):
    1631-1638

    Radars utilizing ultra-wide-band (UWB) pulses are attractive as an environment measurement method for various applications including household robots. Suitable filtering is essential for accurate ranging, which requires an accurate waveform estimation. This paper presents a high-resolution algorithm of estimating target location and scattered waveforms, whose accuracies are interdependent. The technique relies on iterative improvements of estimated waveforms. Description of the algorithm is followed by statistical simulation examples. The performance of the algorithm is contrasted with conventional ones and statistical bounds. Results indicate that our proposed algorithm has a remarkable performance, which is close to the theoretical limit. Next, we clarify the problem of applying HCT to multiple targets. HCT for multiple targets can not be used as an estimated waveform because of interference waves from other targets. We propose an interference suppression algorithm based on a neural network, and show an application example of the algorithm.

  • Parallel Information Retrieval with Query Expansion

    Yoojin CHUNG  

     
    LETTER-Contents Technology and Web Information Systems

      Vol:
    E87-D No:6
      Page(s):
    1593-1595

    An information retrieval (IR) system with query expansion on a low-cost high-performance PC cluster environment is implemented. We study how query performance is affected by query expansion and two declustering methods using two standard Korean test collections. According to the experiments, the greedy method shows about 20% enhancement overall when compared with the lexical method.

  • Performance Analysis of Transmission Rate Scheduling Schemes for Integrated Voice/Data Service in Burst-Switching DS/CDMA System

    Meejoung KIM  

     
    LETTER-Wireless Communication Technology

      Vol:
    E87-B No:6
      Page(s):
    1691-1696

    This letter shows the performance comparisons of several different rate scheduling schemes for non-real time data service over the uplink of burst switching-based direct sequence code division multiple access (DS/CDMA) system to support the integrated voice/data service. The closed-form solution of optimal scheduling formulation, which minimizes average transmission delay when all of the active data users are transmitting simultaneously, is presented and mathematical analyses with other rate scheduling schemes, which provide efficiency criterion of transmission delay for rate scheduling schemes, are performed. Numerical results show the analyses explicitly.

  • Three Point Based Registration for Binocular Augmented Reality

    Steve VALLERAND  Masayuki KANBARA  Naokazu YOKOYA  

     
    PAPER-Multimedia Pattern Processing

      Vol:
    E87-D No:6
      Page(s):
    1554-1565

    In order to perform the registration of virtual objects in vision-based augmented reality systems, the estimation of the relation between the real and virtual worlds is needed. This paper presents a three-point vision-based registration method for video see-through augmented reality systems using binocular cameras. The proposed registration method is based on a combination of monocular and stereoscopic registration methods. A correction method that performs an optimization of the registration by correcting the 2D positions in the images of the marker feature points is proposed. Also, an extraction strategy based on color information is put forward to allow the system to be robust to fast user's motion. In addition, a quantification method is used in order to evaluate the stability of the produced registration. Timing and stability results are presented. The proposed registration method is proven to be more stable than the standard stereoscopic registration method and to be independent of the distance. Even when the user moves quickly, our developed system succeeds in producing stable three-point based registration. Therefore, our proposed methods can be considered as interesting alternatives to produce the registration in binocular augmented reality systems when only three points are available.

  • Web First Adaptive Traffic Engineering

    Guangyi LIU  Yang YANG  Xiaokang LIN  

     
    LETTER-Network

      Vol:
    E87-B No:6
      Page(s):
    1750-1755

    Internet traffic engineering is much important for Internet Service Providers (ISPs) today, since it can be used to fully utilize already deployed network resources. For ISPs, the requirements for traffic engineering should be simple, easy to configure, cost-effective and efficient. Based on these considerations, we propose an algorithm called Web First Adaptive Traffic Engineering (WFATE). Since World Wide Web (WWW) services dominate most of the total Internet traffic and WWW flows are not long-lived, we only apply load balancing to WWW traffic in the algorithm. It can be shown that the number of coexistent WWW flows at an ingress node is almost certainly below a bound, and thus a forward-per-flow mechanism without keeping track of the state of each flow is feasible. This mechanism can balance traffic load at fine granularity and therefore get better performance. Through simulations and performance comparison, it is shown that WFATE is quite efficient, which can improve the network throughput averagely by 26% under the "dense source" traffic pattern and 9% under the "sparse source" traffic pattern.

  • Motion Vector Based Error Concealment Algorithms for Video Decoder

    Mei-Juan CHEN  Che-Shing CHEN  Ching-Ting HSU  

     
    PAPER-Multimedia Systems

      Vol:
    E87-B No:6
      Page(s):
    1648-1659

    Compressed video bitstream is sensitive to errors that may degrade the reconstructed images severely even the bit error rate is small. One approach to combat the impact of error is error concealment at the decoder without increasing the bit rate and changing the encoder. We propose motion vector based error concealment algorithms to recover the motion vector per pixel instead of that per block according to the relation of neighboring motion vectors. The displacement per pixel can be estimated more accurately by using the tendency of neighboring motion vectors. Besides, we use not only the relation among motion vectors, but also the pixels. The pixels of the error block are divided into different parts according to their consistency with neighboring blocks and the displacement at each pixel of these parts is interpolated by relative motion vectors. From simulation results, the proposed motion vector based methods provide better reconstruction quality for damaged images than other methods.

  • 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.

13241-13260hit(20498hit)