The search functionality is under construction.
The search functionality is under construction.

Keyword Search Result

[Keyword] SC(4570hit)

1261-1280hit(4570hit)

  • Analysis of Electrostatic Discharge in Terms of Electromagnetic Interference Assessment: Assessing High Oscillations in ESD Events

    Masao MASUGI  Norihito HIRASAWA  Yoshiharu AKIYAMA  Kazuo MURAKAWA  

     
    LETTER-Electromagnetic Compatibility(EMC)

      Vol:
    E95-B No:11
      Page(s):
    3601-3604

    This paper observes electrostatic discharge (ESD) events in terms of electromagnetic interference (EMI) assessments. To characterize the high frequency oscillations present in ESD waveforms, we use two kinds of discharge electrodes: copper and stainless steel spheres. Based on data gathered under charging voltages of 0.25, 0.5, and 1.0 kV, we examine the energy levels of ESD waveforms. As a result, we find that the high-frequency energy, which is related to the high frequency oscillations in the ESD waveform, was affected by the material of discharge electrodes and the fast movement of discharge electrodes.

  • Perceived Depth Change Produced by Visual Acuity Difference between the Eyes

    Kei SADAKUNI  Takuya INOUE  Hirotsugu YAMAMOTO  Shiro SUYAMA  

     
    PAPER

      Vol:
    E95-C No:11
      Page(s):
    1707-1715

    Three methods of presenting a three-dimensional (3-D) image – a real object, a protruding stereoscopic display, and the depth-fused 3-D (DFD) display – have different tendencies for the change in perceived depth produced when the visual acuity of the dominant eye is decreased by an occlusion foil. These different tendencies are estimated from the slope and correlation coefficient of the plot of perceived depth difference versus stimuli depth difference. This estimation was derived using the same experimental system setup composed of two displays and a half mirror for all three 3-D display methods. The perceived depth difference was measured for four subjects by calipers using two fingers. The slope and correlation coefficient had almost the same tendencies as follows. The real object had the smallest decrease among the three 3-D display methods when the dominant eye's visual acuity was decreased and the protruding stereoscopic display had the largest decrease. The DFD display method had an intermediate decrease between those of the real object and protruding stereoscopic display. When the dominant eye's visual acuity was high enough, the differences among the three 3-D display methods were small. When its visual acuity was decreased, the differences increased among the three 3-D display methods and became statistically significant.

  • Effect of Impurity in Discharge Gas on High γ Properties of Newly Developed CeSrO Film for Novel Plasma Display Panel Open Access

    Yasuhiro YAMAUCHI  Yusuke FUKUI  Yosuke HONDA  Michiko OKAFUJI  Masahiro SAKAI  Mikihiko NISHITANI  Yasushi YAMAUCHI  

     
    INVITED PAPER

      Vol:
    E95-C No:11
      Page(s):
    1761-1768

    The discharge properties and chemical surface stability of CeO2 containing Sr (CeSrO) as the candidate for high-γ protective layer of noble plasma display panels (PDPs) are characterized. CeSrO films have superior chemical stability, because of the decrease in reactiveness on surface due to their fluorite structure. The discharge voltage is 50 V lower than that of MgO films for a pure discharge gas of Ne/Xe = 85/15 at 60 kPa. However the topmost surface, monolayer, of the CeSrO film relevant to the discharge property is hardly recovered from the damage by CO2 impurity in discharge gas. We can expect that by pumping down to a sufficiently low CO2 partial pressure (lower than 1 10-3 Pa), PDP panels with very high efficiency are realized with CeSrO protective layer.

  • Effect of Multiple Antennas on the Transport Capacity in Large-Scale Ad Hoc Networks

    Won-Yong SHIN  Koji ISHIBASHI  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E95-B No:10
      Page(s):
    3113-3119

    A one-dimensional ad hoc network with a single active source–destination pair is analyzed in terms of transport capacity, where each node uses multiple antennas. The analysis is based on using a multi-hop opportunistic routing transmission in the presence of fading. Specifically, the lower and upper bounds on the transport capacity are derived and their scaling law is analyzed as the node density, λ, is assumed to be infinitely large. The lower and upper bounds are shown to have the same scaling (ln λ)1/α, where α denotes the path-loss exponent. We also show that using multiple antennas at each node does not fundamentally change the scaling law.

  • An Efficient Route Optimization Scheme for Multiple LMAs in PMIPv6 Domain

    Won-Kyeong SEO  Kang-Won LEE  Jae-In CHOI  You-Ze CHO  

     
    PAPER-Network

      Vol:
    E95-B No:10
      Page(s):
    3149-3157

    PMIPv6 is the IETF standard for a network-based localized mobility management protocol. In PMIPv6, MNs are topologically anchored at an LMA, which forwards all data for registered MNs. However, since all data packets destined for MNs always traverse the MNs' LMA, the end-to-end packet delay is increased. Therefore, this paper proposes an RO scheme in single and multiple LMA environments. For efficient RO possibility detection, an IPv6 RO extension header and initial RO procedure are proposed. Plus, an effective post-handover RO procedure is presented, along with a packet forwarding scheme to avoid the race condition problem during an RO operation. A Performance evaluation confirms that the proposed scheme can significantly reduce the end-to-end delay, signaling overhead, and RO latency when compared with existing RO schemes.

  • Single-Channel Adaptive Noise Canceller for Heart Sound Enhancement during Auscultation

    Yunjung LEE  Pil Un KIM  Jin Ho CHO  Yongmin CHANG  Myoung Nam KIM  

     
    LETTER-Biological Engineering

      Vol:
    E95-D No:10
      Page(s):
    2593-2596

    In this paper, a single-channel adaptive noise canceller (SCANC) is proposed to enhance heart sounds during auscultation. Heart sounds provide important information about the condition of the heart, but other sounds interfere with heart sounds during auscultation. The adaptive noise canceller (ANC) is widely used to reduce noises from biomedical signals, but it is not suitable for enhancing auscultatory sounds acquired by a stethoscope. While the ANC needs two inputs, a stethoscope provides only one input. Other approaches, such as ECG gating and wavelet de-noising, are rather complex and difficult to implement as real-time systems. The proposed SCANC uses a single-channel input based on Heart Sound Inherency Indicator and reference generator. The architecture is simple, so it can be easily implemented in real-time systems. It was experimentally confirmed that the proposed SCANC is efficient for heart sound enhancement and is robust against the heart rate variations.

  • A Channel-Aware Scheduling Scheme for (m,k)-Firm Streams in Wireless Multimedia Sensor Networks

    Changxiao ZHAO  Huagang XIONG  

     
    LETTER-Network

      Vol:
    E95-B No:10
      Page(s):
    3312-3315

    In this letter, we propose a channel-aware scheduling algorithm to support real-time applications in wireless multimedia sensor networks. Multimedia streams are sensitive to real-time delivery but can tolerate some packet loss. Therefore, this specific application is modelled as an (m,k)-firm stream. To satisfy the real-time requirements, a scheduling scheme that provides packet partitioning and real-time delivery is proposed. Packet partitioning combines static assignment and dynamic adjustment while considering the channel state. The scheme is designed to minimize the number of mandatory packets delivered in a bad channel state to avoid dynamic failure. In addition, automatic repeat request technology is introduced to enhance the reliability of real-time delivery. Simulations and analyses show that the proposed scheme has a good ability to withstand a bad channel status.

  • Cache-Aware Virtual Machine Scheduling on Multi-Core Architecture

    Cheol-Ho HONG  Young-Pil KIM  Seehwan YOO  Chi-Young LEE  Chuck YOO  

     
    PAPER-Software System

      Vol:
    E95-D No:10
      Page(s):
    2377-2392

    Facing practical limits to increasing processor frequencies, manufacturers have resorted to multi-core designs in their commercial products. In multi-core implementations, cores in a physical package share the last-level caches to improve inter-core communication. To efficiently exploit this facility, operating systems must employ cache-aware schedulers. Unfortunately, virtualization software, which is a foundation technology of cloud computing, is not yet cache-aware or does not fully exploit the locality of the last-level caches. In this paper, we propose a cache-aware virtual machine scheduler for multi-core architectures. The proposed scheduler exploits the locality of the last-level caches to improve the performance of concurrent applications running on virtual machines. For this purpose, we provide a space-partitioning algorithm that migrates and clusters communicating virtual CPUs (VCPUs) in the same cache domain. Second, we provide a time-partitioning algorithm that co-schedules or schedules in sequence clustered VCPUs. Finally, we present a theoretical analysis that proves our scheduling algorithm is more efficient in supporting concurrent applications than the default credit scheduler in Xen. We implemented our virtual machine scheduler in the recent Xen hypervisor with para-virtualized Linux-based operating systems. We show that our approach can improve performance of concurrent virtual machines by up to 19% compared to the credit scheduler.

  • Parallel FDTD Simulation of Microwave Propagation Characteristics in Forest Model for WiMAX Signal

    Yasumitsu MIYAZAKI  Koichi TAKAHASHI  Nobuo GOTO  

     
    PAPER

      Vol:
    E95-C No:10
      Page(s):
    1572-1579

    WiMAX wireless communication has been rapidly developed for broadband mobile communication. Mobile WiMAX communication system uses microwave carrier of 2.5 GHz frequency band and modulation is OFDM mainly. By using OFDM technique, WiMAX provide high speed and reliable communication against multi pass interferences due to the presence of obstacles in communication channels. To design excellent high performance mobile communication systems, accurate evaluation of communication system is indispensable. By using parallel FDTD, we studied fundamental characteristics of microwave propagation and scattering in urban area. We also studied wave propagation and scattering by forest and trees using FDTD method. The effects of multiple scattering and attenuation of microwave by forest are severe factors of high speed wireless communications. In this paper, signal propagation and receiving characteristics of OFDM modulated wave are studied by parallel FDTD method. Propagation, reflection, scattering, interference and delay of digital code signals in received code signals are evaluated to show the environmental characteristics. Parallel FDTD methods are applied for signal and noise analysis about several different complex models and inhomogeneous materials such as forests in long distance communication channels.

  • Dimensionality Reduction by Locally Linear Discriminant Analysis for Handwritten Chinese Character Recognition

    Xue GAO  Jinzhi GUO  Lianwen JIN  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E95-D No:10
      Page(s):
    2533-2543

    Linear Discriminant Analysis (LDA) is one of the most popular dimensionality reduction techniques in existing handwritten Chinese character (HCC) recognition systems. However, when used for unconstrained handwritten Chinese character recognition, the traditional LDA algorithm is prone to two problems, namely, the class separation problem and multimodal sample distributions. To deal with these problems,we propose a new locally linear discriminant analysis (LLDA) method for handwritten Chinese character recognition.Our algorithm operates as follows. (1) Using the clustering algorithm, find clusters for the samples of each class. (2) Find the nearest neighboring clusters from the remaining classes for each cluster of one class. Then, use the corresponding cluster means to compute the between-class scatter matrix in LDA while keeping the within-class scatter matrix unchanged. (3) Finally, apply feature vector normalization to further improve the class separation problem. A series of experiments on both the HCL2000 and CASIA Chinese character handwriting databases show that our method can effectively improve recognition performance, with a reduction in error rate of 28.7% (HCL2000) and 16.7% (CASIA) compared with the traditional LDA method.Our algorithm also outperforms DLA (Discriminative Locality Alignment,one of the representative manifold learning-based dimensionality reduction algorithms proposed recently). Large-set handwritten Chinese character recognition experiments also verified the effectiveness of our proposed approach.

  • SAFE: A Scalable Autonomous Fault-Tolerant Ethernet Scheme for Large-Scale Star Networks

    Dong Ho LEE  You-Ze CHO  Hoang-Anh PHAM  Jong Myung RHEE  Yeonseung RYU  

     
    PAPER-Network

      Vol:
    E95-B No:10
      Page(s):
    3158-3167

    In this paper, we present a new fault-tolerant, large-scale star network scheme called Scalable Autonomous Fault-tolerant Ethernet (SAFE). The primary goal of a SAFE scheme is to provide network scalability and autonomous fault detection and recovery. SAFE divides a large-scale, mission-critical network, such as the naval combatant network, into several subnets by limiting the number of nodes in each subnet. This network can be easily configured as a star network in order to meet fault recovery time requirements. For SAFE, we developed a novel mechanism for inter-subnet fault detection and recovery; a conventional Ethernet-based heartbeat mechanism is used in each subnet. Theoretical and experimental performance analyses of SAFE in terms of fail-over time were conducted under various network failure scenarios. The results validate our scheme.

  • Online Continuous Scale Estimation of Hand Gestures

    Woosuk KIM  Hideaki KUZUOKA  Kenji SUZUKI  

     
    PAPER-Human-computer Interaction

      Vol:
    E95-D No:10
      Page(s):
    2447-2455

    The style of a gesture provides significant information for communication, and thus understanding the style is of great importance in improving gestural interfaces using hand gestures. We present a novel method to estimate temporal and spatial scale—which are considered principal elements of the style—of hand gestures. Gesture synchronization is proposed for matching progression between spatio-temporally varying gestures, and scales are estimated based on the progression matching. For comparing gestures of various sizes and speeds, gesture representation is defined by adopting turning angle representation. Also, LCSS is used as a similarity measure for reliability and robustness to noise and outliers. Performance of our algorithm is evaluated with synthesized data to show the accuracy and robustness to noise and experiments are carried out using recorded hand gestures to analyze applicability under real-world situations.

  • Small Multi-Band Antenna with Tuning Function for Body-Centric Wireless Communications

    Chia-Hsien LIN  Zhengyi LI  Kazuyuki SAITO  Masaharu TAKAHASHI  Koichi ITO  

     
    PAPER

      Vol:
    E95-B No:10
      Page(s):
    3074-3080

    The research on body-centric wireless communications (BCWCs) is becoming very hot because of numerous applications, especially the application of E-health systems. Therefore, a small multi-band and low-profile planar inverted-F antenna (PIFA) with tuning function is presented for BCWCs in this paper. In order to achieve multi-band operation, there are two branches in the antenna: the longer branch low frequency band (950–956 MHz), and the shorter branch with a varactor diode embedded for high frequency bands. By supplying different DC voltages, the capacitance of the varactor diode varies, so the resonant frequency can be tuned without changing the dimension of the antenna. While the bias is set at 6 V and 14 V, WiMAX and ISM bands can be covered, respectively. From the radiation patterns, at 950 MHz, the proposed antenna is suitable for on-body communications, and in WiMAX and ISM bands, they are suitable for both on-body and off-body communications.

  • TL-Rank: A Blend of Text and Link Information for Measuring Similarity in Scientific Literature Databases

    Seok-Ho YOON  Ji-Su KIM  Sang-Wook KIM  Choonhwa LEE  

     
    LETTER-Artificial Intelligence, Data Mining

      Vol:
    E95-D No:10
      Page(s):
    2556-2559

    This paper presents a novel similarity measure that computes similarity scores among scientific research papers. The text of a given paper in online scientific literature is often found to be incomplete in terms of its potential to be compared with others, which likely leads to inaccurate results. Our solution to this problem makes use of both text and link information of a paper in question for similarity scores in that the comparison text of the paper is strengthened by adding that of papers related to it. More accurate similarity scores can be computed by reinforcing the input with the citations of the paper as well as the citations included within the paper. The efficacy of the proposed measure is validated through our extensive performance evaluation study which demonstrates a substantial gain.

  • Mode-Matching Analysis for Circular and Annular Aperture Scattering Open Access

    Hyo Joon EOM  Young Seung LEE  

     
    INVITED PAPER

      Vol:
    E95-C No:10
      Page(s):
    1566-1571

    The mode-matching applications to scattering from circular and annular apertures in a thick perfectly conducting plane are reviewed. The Hankel and Weber transforms are utilized to solve the boundary-value problems of circular and annular apertures. Simple electrostatic problems are presented to illustrate the mode-matching method in terms of the Hankel and Weber transforms. Various types of Weber transform are discussed with boundary-value problems. Electromagnetic radiation and scattering from circular and annular aperture geometries are summarized. The utility of the mode-matching method in circular and annular aperture scattering is emphasized.

  • Accurate 3-Dimensional Imaging Method Based on Extended RPM for Rotating Target Model

    Shouhei KIDERA  Hiroyuki YAMADA  Tetsuo KIRIMOTO  

     
    PAPER-Sensing

      Vol:
    E95-B No:10
      Page(s):
    3279-3289

    Three-dimensional (3-D) reconstruction techniques employed by airborne radars are essential for object recognition in scenarios where optically vision is blurry, and are required for the monitoring of disasters and coast-guard patrols. There have been reports on 3-D reconstruction methods that exploit the layover appearing in inverse synthetic aperture radar (ISAR) imagery, which are suitable for the recognition of artificial targets such as buildings, aircraft or ships. However, existing methods assume only a point target or the aggregate of point targets, and most require the tracking of the multiple points over sequential ISAR images. In the case of a solid object with a continuous boundary, such as a wire or polyhedral structure, the positioning accuracy of such methods is severely degraded owing to scattering centers continuously shifting on the target surface with changes in the rotation angle. To overcome this difficulty, this paper extends the original Range Points Migration (RPM) method to the ISAR observation model, where a double mono-static model with two transmitting and receiving antennas is introduced to suppress cross-range ambiguity. The results of numerical simulation and experimental validation demonstrate that the extended RPM method has a distinct advantage for accurate 3-D imaging, even for non-point targets.

  • Partial Reconfiguration of Flux Limiter Functions in MUSCL Scheme Using FPGA

    Mohamad Sofian ABU TALIP  Takayuki AKAMINE  Yasunori OSANA  Naoyuki FUJITA  Hideharu AMANO  

     
    PAPER-Computer System

      Vol:
    E95-D No:10
      Page(s):
    2369-2376

    Computational Fluid Dynamics (CFD) is used as a common design tool in the aerospace industry. UPACS, a package for CFD, is convenient for users, since a customized simulator can be built just by selecting desired functions. The problem is its computation speed, which is difficult to enhance by using the clusters due to its complex memory access patterns. As an economical solution, accelerators using FPGAs are hopeful candidate. However, the total scale of UPACS is too large to be implemented on small numbers of FPGAs. For cost efficient implementation, partial reconfiguration which dynamically loads only required functions is proposed in this paper. Here, the MUSCL scheme, which is used frequently in UPACS, is selected as a target. Partial reconfiguration is applied to the flux limiter functions (FLF) in MUSCL. Four FLFs are implemented for Turbulence MUSCL (TMUSCL) and eight FLFs are for Convection MUSCL (CMUSCL). All FLFs are developed independently and separated from the top MUSCL module. At start-up, only required FLFs are selected and deployed in the system without interfering the other modules. This implementation has successfully reduced the resource utilization by 44% to 63%. Total power consumption also reduced by 33%. Configuration speed is improved by 34-times faster as compared to full reconfiguration method. All implemented functions achieved at least 17 times speed-up performance compared with the software implementation.

  • On Kernel Parameter Selection in Hilbert-Schmidt Independence Criterion

    Masashi SUGIYAMA  Makoto YAMADA  

     
    LETTER-Artificial Intelligence, Data Mining

      Vol:
    E95-D No:10
      Page(s):
    2564-2567

    The Hilbert-Schmidt independence criterion (HSIC) is a kernel-based statistical independence measure that can be computed very efficiently. However, it requires us to determine the kernel parameters heuristically because no objective model selection method is available. Least-squares mutual information (LSMI) is another statistical independence measure that is based on direct density-ratio estimation. Although LSMI is computationally more expensive than HSIC, LSMI is equipped with cross-validation, and thus the kernel parameter can be determined objectively. In this paper, we show that HSIC can actually be regarded as an approximation to LSMI, which allows us to utilize cross-validation of LSMI for determining kernel parameters in HSIC. Consequently, both computational efficiency and cross-validation can be achieved.

  • Factor Analysis of Neighborhood-Preserving Embedding for Speaker Verification

    Chunyan LIANG  Lin YANG  Qingwei ZHAO  Yonghong YAN  

     
    LETTER-Speech and Hearing

      Vol:
    E95-D No:10
      Page(s):
    2572-2576

    In this letter, we adopt a new factor analysis of neighborhood-preserving embedding (NPE) for speaker verification. NPE aims at preserving the local neighborhood structure on the data and defines a low-dimensional speaker space called neighborhood-preserving embedding space. We compare the proposed method with the state-of-the-art total variability approach on the telephone-telephone core condition of the NIST 2008 Speaker Recognition Evaluation (SRE) dataset. The experimental results indicate that the proposed NPE method outperforms the total variability approach, providing up to 24% relative improvement.

  • Process Scheduling Based Memory Energy Management for Multi-Core Mobile Devices

    Tiefei ZHANG  Tianzhou CHEN  

     
    PAPER-Systems and Control

      Vol:
    E95-A No:10
      Page(s):
    1700-1707

    The energy consumption is always a serious problem for mobile devices powered by battery. As the capacity and density of off-chip memory continuous to scale, its energy consumption accounts for a considerable amount of the whole system energy. There are therefore strong demands for energy efficient techniques towards memory system. Different from previous works, we explore the different power management modes of the off-chip memory by process scheduling for the multi-core mobile devices. In particular, we schedule the processes based on their memory access characteristics to maximize the number of the memory banks being in low power mode. We propose a fast approximation algorithm to solve the scheduling process problem for the dual-core mobile device. And for those equipped with more than two cores, we prove that the scheduling process problem is NP-Hard, and propose two heuristic algorithms. The proposed algorithms are evaluated through a series of experiments, for which we have encouraging results.

1261-1280hit(4570hit)