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1161-1180hit(16314hit)

  • A Multiobjective Optimization Dispatch Method of Wind-Thermal Power System

    Xiaoxuan GUO  Renxi GONG  Haibo BAO  Zhenkun LU  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2020/09/18
      Vol:
    E103-D No:12
      Page(s):
    2549-2558

    It is well known that the large-scale access of wind power to the power system will affect the economic and environmental objectives of power generation scheduling, and also bring new challenges to the traditional deterministic power generation scheduling because of the intermittency and randomness of wind power. In order to deal with these problems, a multiobjective optimization dispatch method of wind-thermal power system is proposed. The method can be described as follows: A multiobjective interval power generation scheduling model of wind-thermal power system is firstly established by describing the wind speed on wind farm as an interval variable, and the minimization of fuel cost and pollution gas emission cost of thermal power unit is chosen as the objective functions. And then, the optimistic and pessimistic Pareto frontiers of the multi-objective interval power generation scheduling are obtained by utilizing an improved normal boundary intersection method with a normal boundary intersection (NBI) combining with a bilevel optimization method to solve the model. Finally, the optimistic and pessimistic compromise solutions is determined by a distance evaluation method. The calculation results of the 16-unit 174-bus system show that by the proposed method, a uniform optimistic and pessimistic Pareto frontier can be obtained, the analysis of the impact of wind speed interval uncertainty on the economic and environmental indicators can be quantified. In addition, it has been verified that the Pareto front in the actual scenario is distributed between the optimistic and pessimistic Pareto front, and the influence of different wind power access levels on the optimistic and pessimistic Pareto fronts is analyzed.

  • Formulation of a Test Pattern Measure That Counts Distinguished Fault-Pairs for Circuit Fault Diagnosis

    Tsutomu INAMOTO  Yoshinobu HIGAMI  

     
    PAPER

      Vol:
    E103-A No:12
      Page(s):
    1456-1463

    In this paper, we aim to develop technologies for the circuit fault diagnosis and propose a formulation of a measure of a test pattern for the circuit fault diagnosis. Given a faulty circuit, the fault diagnosis is to deduce locations of faults that had occurred in the circuit. The fault diagnosis is executed in software before the failure analysis by which engineers inspect physical defects, and helps to improve the manufacturing process which yielded faulty circuits. The heart of the fault diagnosis is to distinguish between candidate faults by using test patterns, which are applied to the circuit-under-diagnosis (CUD), and thus test patterns that can distinguish as many faults as possible need to be generated. This fact motivates us to consider the test pattern measure based on the number of fault-pairs that become distinguished by a test pattern. To the best of the authors' knowledge, that measure requires the computational time of complexity order O(NF2), where NF denotes the number of candidate faults. Since NF is generally large for real industrial circuits, the computational time of the measure is long even when a high-performance computer is used. The formulation proposed in this paper makes it possible to calculate the measure in the computational complexity of O(NF log NF), and thus that measure is useful for the test pattern selection in the fault diagnosis. In computational experiments, the effectiveness of the formulation is demonstrated as samples of computational times of the measure calculated by the traditional and the proposed formulae and thorough comparisons between several greedy heuristics which are based on the measure.

  • On the Signal-to-Noise Ratio for Boolean Functions

    Yu ZHOU  Wei ZHAO  Zhixiong CHEN  Weiqiong WANG  Xiaoni DU  

     
    LETTER-Cryptography and Information Security

      Pubricized:
    2020/05/25
      Vol:
    E103-A No:12
      Page(s):
    1659-1665

    The notion of the signal-to-noise ratio (SNR), proposed by Guilley, et al. in 2004, is a property that attempts to characterize the resilience of (n, m)-functions F=(f1,...,fm) (cryptographic S-boxes) against differential power analysis. But how to study the signal-to-noise ratio for a Boolean function still appears to be an important direction. In this paper, we give a tight upper and tight lower bounds on SNR for any (balanced) Boolean function. We also deduce some tight upper bounds on SNR for balanced Boolean function satisfying propagation criterion. Moreover, we obtain a SNR relationship between an n-variable Boolean function and two (n-1)-variable decomposition functions. Meanwhile, we give SNR(f⊞g) and SNR(f⊡g) for any balanced Boolean functions f, g. Finally, we give a lower bound on SNR(F), which determined by SNR(fi) (1≤i≤m), for (n, m)-function F=(f1,f2,…,fm).

  • High Level Congestion Detection from C/C++ Source Code for High Level Synthesis Open Access

    Masato TATSUOKA  Mineo KANEKO  

     
    PAPER

      Vol:
    E103-A No:12
      Page(s):
    1437-1446

    High level synthesis (HLS) is a source-code-driven Register Transfer Level (RTL) design tool, and the performance, the power consumption, and the area of a generated RTL are limited partly by the description of a HLS input source code. In order to break through such kind of limitation and to get a further optimized RTL, the optimization of the input source code is indispensable. Routing congestion is one of such problems we need to consider the refinement of a HLS input source code. In this paper, we propose a novel HLS flow that performs code improvements by detecting congested parts directly from HLS input source code without using physical logic synthesis, and regenerating the input source code for HLS. In our approach, the origin of the wire congestion is detected from the HLS input source code by applying pattern matching on Program-Dependence Graph (PDG) constructed from the HLS input source code, the possibility of wire congestion is reported.

  • Multi-Resolution Fusion Convolutional Neural Networks for Intrapulse Modulation LPI Radar Waveforms Recognition

    Xue NI  Huali WANG  Ying ZHU  Fan MENG  

     
    PAPER-Sensing

      Pubricized:
    2020/06/15
      Vol:
    E103-B No:12
      Page(s):
    1470-1476

    Low Probability of Intercept (LPI) radar waveform has complex and diverse modulation schemes, which cannot be easily identified by the traditional methods. The research on intrapulse modulation LPI radar waveform recognition has received increasing attention. In this paper, we propose an automatic LPI radar waveform recognition algorithm that uses a multi-resolution fusion convolutional neural network. First, signals embedded within the noise are processed using Choi-William Distribution (CWD) to obtain time-frequency feature images. Then, the images are resized by interpolation and sent to the proposed network for training and identification. The network takes a dual-channel CNN structure to obtain features at different resolutions and makes features fusion by using the concatenation and Inception module. Extensive simulations are carried out on twelve types of LPI radar waveforms, including BPSK, Costas, Frank, LFM, P1~P4, and T1~T4, corrupted with additive white Gaussian noise of SNR from 10dB to -8dB. The results show that the overall recognition rate of the proposed algorithm reaches 95.1% when the SNR is -6dB. We also try various sample selection methods related to the recognition task of the system. The conclusion is that reducing the samples with SNR above 2dB or below -8dB can effectively improve the training speed of the network while maintaining recognition accuracy.

  • Unconstrained Facial Expression Recognition Based on Feature Enhanced CNN and Cross-Layer LSTM

    Ying TONG  Rui CHEN  Ruiyu LIANG  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2020/07/30
      Vol:
    E103-D No:11
      Page(s):
    2403-2406

    LSTM network have shown to outperform in facial expression recognition of video sequence. In view of limited representation ability of single-layer LSTM, a hierarchical attention model with enhanced feature branch is proposed. This new network architecture consists of traditional VGG-16-FACE with enhanced feature branch followed by a cross-layer LSTM. The VGG-16-FACE with enhanced branch extracts the spatial features as well as the cross-layer LSTM extracts the temporal relations between different frames in the video. The proposed method is evaluated on the public emotion databases in subject-independent and cross-database tasks and outperforms state-of-the-art methods.

  • Flex-LIONS: A Silicon Photonic Bandwidth-Reconfigurable Optical Switch Fabric Open Access

    Roberto PROIETTI  Xian XIAO  Marjan FARIBORZ  Pouya FOTOUHI  Yu ZHANG  S. J. Ben YOO  

     
    INVITED PAPER

      Pubricized:
    2020/05/14
      Vol:
    E103-B No:11
      Page(s):
    1190-1198

    This paper summarizes our recent studies on architecture, photonic integration, system validation and networking performance analysis of a flexible low-latency interconnect optical network switch (Flex-LIONS) for datacenter and high-performance computing (HPC) applications. Flex-LIONS leverages the all-to-all wavelength routing property in arrayed waveguide grating routers (AWGRs) combined with microring resonator (MRR)-based add/drop filtering and multi-wavelength spatial switching to enable topology and bandwidth reconfigurability to adapt the interconnection to different traffic profiles. By exploiting the multiple free spectral ranges of AWGRs, it is also possible to provide reconfiguration while maintaining minimum-diameter all-to-all interconnectivity. We report experimental results on the design, fabrication, and system testing of 8×8 silicon photonic (SiPh) Flex-LIONS chips demonstrating error-free all-to-all communication and reconfiguration exploiting different free spectral ranges (FSR0 and FSR1, respectively). After reconfiguration in FSR1, the bandwidth between the selected pair of nodes is increased from 50Gb/s to 125Gb/s while an all interconnectivity at 25Gb/s is maintained using FSR0. Finally, we investigate the use of Flex-LIONS in two different networking scenarios. First, networking simulations for a 256-node datacenter inter-rack communication scenario show the potential latency and energy benefits when using Flex-LIONS for optical reconfiguration based on different traffic profiles (a legacy fat-tree architecture is used for comparison). Second, we demonstrate the benefits of leveraging two FSRs in an 8-node 64-core computing system to provide reconfiguration for the hotspot nodes while maintaining minimum-diameter all-to-all interconnectivity.

  • Generative Adversarial Network Using Weighted Loss Map and Regional Fusion Training for LDR-to-HDR Image Conversion

    Sung-Woon JUNG  Hyuk-Ju KWON  Dong-Min SON  Sung-Hak LEE  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2020/08/18
      Vol:
    E103-D No:11
      Page(s):
    2398-2402

    High dynamic range (HDR) imaging refers to digital image processing that modifies the range of color and contrast to enhance image visibility. To create an HDR image, two or more images that include various information are needed. In order to convert low dynamic range (LDR) images to HDR images, we consider the possibility of using a generative adversarial network (GAN) as an appropriate deep neural network. Deep learning requires a great deal of data in order to build a module, but once the module is created, it is convenient to use. In this paper, we propose a weight map for local luminance based on learning to reconstruct locally tone-mapped images.

  • Fabrication and Strain Vector Characteristics of Multicore Fiber Based FBG

    Zhao SUN  Shunge DENG  Xin MA  Haimei LUO  Xinwan LI  

     
    PAPER

      Pubricized:
    2020/05/22
      Vol:
    E103-B No:11
      Page(s):
    1305-1309

    Through novel rotation writing method of Bragg grating in multicore fiber, its strain vector characteristics are analyzed. The relation between the rotation angle and the strain curvature sensitivity is obtained. Reconstruction of strain vector is verified.

  • Design and Performance Analysis of a Skin-Stretcher Device for Urging Head Rotation

    Takahide ITO  Yuichi NAKAMURA  Kazuaki KONDO  Espen KNOOP  Jonathan ROSSITER  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2020/08/03
      Vol:
    E103-D No:11
      Page(s):
    2314-2322

    This paper introduces a novel skin-stretcher device for gently urging head rotation. The device pulls and/or pushes the skin on the user's neck by using servo motors. The user is induced to rotate his/her head based on the sensation caused by the local stretching of skin. This mechanism informs the user when and how much the head rotation is requested; however it does not force head rotation, i.e., it allows the user to ignore the stimuli and to maintain voluntary movements. We implemented a prototype device and analyzed the performance of the skin stretcher as a human-in-the-loop system. Experimental results define its fundamental characteristics, such as input-output gain, settling time, and other dynamic behaviors. Features are analyzed, for example, input-output gain is stable within the same installation condition, but various between users.

  • Impact of Sampling and Quantization on Kramers-Kronig Relation-Based Direct Detection Open Access

    Takaha FUJITA  Kentaro TOBA  Kariyawasam Indipalage Amila SAMPATH  Joji MAEDA  

     
    PAPER

      Pubricized:
    2020/06/08
      Vol:
    E103-B No:11
      Page(s):
    1291-1298

    Impact of sampling frequency and the number of quantization bit of analog-to-digital conversion (ADC) in a direct detection lightwave system using Kramers-Kronig (KK) relation, which has been attracting attention in recent years, are numerically investigated. We studied the effect of spectral broadening caused by nonlinear operations (logarithm, square root) of the KK algorithm when the frequency gap (shift frequency) between the modulated signal and the optical tone is varied. We found that reception performances depend on both the ADC bandwidth and the relative positions of the optical tone and the spectrum. Spectral broadening caused by the logarithm operation of the KK algorithm is found to be the dominant factor of signal distortion in an ADC bandwidth limited system. We studied the effect of the number of quantization bit on the error vector magnitude (EVM) of KK relation based reception in a carrier-to-signal power ratio (CSPR) adjustable transmission system. We found that performances of KK relation based receiver can be improved by increasing the number of quantization bits. For minimum-phase-condition satisfied KK receiver, the required number of quantization bit was found to be 5 bits or more for detection of QPSK, 16-QAM and 64-QAM-modulated signal after 20-km transmission.

  • Efficient Detection for Large-Scale MIMO Systems Using Dichotomous Coordinate Descent Iterations

    Zhi QUAN  Shuhua LV  Li JIANG  

     
    PAPER-Fundamental Theories for Communications

      Pubricized:
    2020/05/08
      Vol:
    E103-B No:11
      Page(s):
    1310-1317

    Massive multiple-input multiple-output (MIMO) is an enabling technology for next-generation wireless systems because it provides significant improvements in data rates compared to existing small-scale MIMO systems. However, the increased number of antennas results in high computational complexity for data detection, and requires more efficient detection algorithms. In this paper, we propose a new data detector based on a box-constrained complex-valued dichotomous coordinate descent (BCC-DCD) algorithm for large-scale MIMO systems. The proposed detector involves two steps. First, a transmitted data vector is detected using the BCC-DCD algorithm with a large number of iterations and high solution precision. Second, an improved soft output is generated by reapplying the BCC-DCD algorithm, but with a considerably smaller number of iterations and 1-bit solution precision. Numerical results demonstrate that the proposed method outperforms existing advanced detectors while possessing lower complexity. Specifically, the proposed method provides significantly better detection performance than a BCC-DCD algorithm with similar complexity. The performance advantage increases as the signal-to-noise ratio and the system size increase.

  • A Study on Optimal Design of Optical Devices Utilizing Coupled Mode Theory and Machine Learning

    Koji KUDO  Keita MORIMOTO  Akito IGUCHI  Yasuhide TSUJI  

     
    PAPER

      Pubricized:
    2020/03/25
      Vol:
    E103-C No:11
      Page(s):
    552-559

    We propose a new design approach to improve the computational efficiency of an optimal design of optical waveguide devices utilizing coupled mode theory (CMT) and a neural network (NN). Recently, the NN has begun to be used for efficient optimal design of optical devices. In this paper, the eigenmode analysis required in the CMT is skipped by using the NN, and optimization with an evolutionary algorithm can be efficiently carried out. To verify usefulness of our approach, optimal design examples of a wavelength insensitive 3dB coupler, a 1 : 2 power splitter, and a wavelength demultiplexer are shown and their transmission properties obtained by the CMT with the NN (NN-CMT) are verified by comparing with those calculated by a finite element beam propagation method (FE-BPM).

  • A Comprehensive Performance Evaluation on Iterative Algorithms for Sensitivity Analysis of Continuous-Time Markov Chains

    Yepeng CHENG  Hiroyuki OKAMURA  Tadashi DOHI  

     
    PAPER-Numerical Analysis and Optimization

      Vol:
    E103-A No:11
      Page(s):
    1252-1259

    This paper discusses how to compute the parametric sensitivity function in continuous-time Markov chains (CTMC). The sensitivity function is the first derivative of the steady-state probability vector regarding a CTMC parameter. Since the sensitivity function is given as a solution of linear equations with a sparse matrix, several linear equation solvers are available to obtain it. In this paper, we consider Jacobi and successive-over relaxation as variants of the Gauss-Seidel algorithm. In addition, we develop an algorithm based on the Takahashi method for the sensitivity function. In numerical experiments, we comprehensively evaluate the performance of these algorithms from the viewpoint of computation time and accuracy.

  • Characterization of Multi-Layer Ceramic Chip Capacitors up to mm-Wave Frequencies for High-Speed Digital Signal Coupling Open Access

    Tsugumichi SHIBATA  Yoshito KATO  

     
    PAPER

      Pubricized:
    2020/04/09
      Vol:
    E103-C No:11
      Page(s):
    575-581

    Capacitive coupling of line coded and DC-balanced digital signals is often used to eliminate steady bias current flow between the systems or components in various communication systems. A multi-layer ceramic chip capacitor is promising for the capacitor of very broadband signal coupling because of its high frequency characteristics expected from the downsizing of the chip recent years. The lower limit of the coupling bandwidth is determined by the capacitance while the higher limit is affected by the parasitic inductance associated with the chip structure. In this paper, we investigate the coupling characteristics up to millimeter wave frequencies by the measurement and simulations. A phenomenon has been found in which the change in the current distribution in the chip structure occur at high frequencies and the coupling characteristics are improved compared to the prediction based on the conventional equivalent circuit model. A new equivalent circuit model of chip capacitor that can express the effect of the improvement has been proposed.

  • All-Optical PAM4 to 16QAM Modulation Format Conversion Using Nonlinear Optical Loop Mirror and 1:2 Coupler Open Access

    Yuta MATSUMOTO  Ken MISHINA  Daisuke HISANO  Akihiro MARUTA  

     
    PAPER

      Pubricized:
    2020/05/14
      Vol:
    E103-B No:11
      Page(s):
    1272-1281

    In inter-data center networks where high transmission capacity and spectral efficiency are required, a 16QAM format is deployed. On the other hand, in intra-data center networks, a PAM4 format is deployed to meet the demand for a simple and low-cost transceiver configuration. For a seamless and effective connection of such heterogeneous networks without using optical-electrical-optical conversion, an all-optical modulation format conversion technique is required. In this paper, we propose an all-optical PAM4 to 16QAM modulation format conversion using nonlinear optical loop mirror. The successful conversion operation from 2 × 26.6-Gbaud PAM4 signals to a 100-Gbps class 16QAM signal is verified by numerical simulation. Compared with an ideal 16QAM signal, the power penalty of the converted 16QAM signal can be kept within 0.51dB.

  • Concatenated LDPC/Trellis Codes: Surpassing the Symmetric Information Rate of Channels with Synchronization Errors

    Ryo SHIBATA  Gou HOSOYA  Hiroyuki YASHIMA  

     
    PAPER-Coding Theory

      Pubricized:
    2020/09/03
      Vol:
    E103-A No:11
      Page(s):
    1283-1291

    We propose a coding/decoding strategy that surpasses the symmetric information rate of a binary insertion/deletion (ID) channel and approaches the Markov capacity of the channel. The proposed codes comprise inner trellis codes and outer irregular low-density parity-check (LDPC) codes. The trellis codes are designed to mimic the transition probabilities of a Markov input process that achieves a high information rate, whereas the LDPC codes are designed to maximize an iterative decoding threshold in the superchannel (concatenation of the ID channels and trellis codes).

  • Validation Measurement of Hybrid Propagation Analysis Suitable for Airport Surface in VHF Band and Its Application to Realistic Situations

    Ryosuke SUGA  Satoshi KURODA  Atsushi KEZUKA  

     
    PAPER

      Pubricized:
    2020/04/10
      Vol:
    E103-C No:11
      Page(s):
    582-587

    Authors had proposed a hybrid electromagnetic field analysis method suitable for an airport surface so far. In this paper, the hybrid method is validated by measurements by using a 1/50 scale-model of an airport considering several layouts of the buildings and sloping ground. The measured power distributions agreed with the analyzed ones within 5 dB errors excepting null points and the null positions of the distribution is also estimated within one wavelength errors.

  • Testing Homogeneity for Normal Mixture Models: Variational Bayes Approach

    Natsuki KARIYA  Sumio WATANABE  

     
    PAPER-Information Theory

      Vol:
    E103-A No:11
      Page(s):
    1274-1282

    The test of homogeneity for normal mixtures has been used in various fields, but its theoretical understanding is limited because the parameter set for the null hypothesis corresponds to singular points in the parameter space. In this paper, we shed a light on this issue from a new perspective, variational Bayes, and offer a theory for testing homogeneity based on it. Conventional theory has not reveal the stochastic behavior of the variational free energy, which is necessary for constructing a hypothesis test, has remained unknown. We clarify it for the first time and construct a new test base on it. Numerical experiments show the validity of our results.

  • Non-Linear Distance Filter for Modeling Effect of a Large Pointer Used in a Gesture-Based Pointing Interface

    Kazuaki KONDO  Takuto FUJIWARA  Yuichi NAKAMURA  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2020/08/03
      Vol:
    E103-D No:11
      Page(s):
    2302-2313

    When using a gesture-based interface for pointing to targets on a wide screen, displaying a large pointer instead of a typical spot pattern reduces disturbance caused by measurement errors of user's pointing posture. However, it remains unclear why a large pointer helps facilitate easy pointing. To examine this issue, in this study we propose a mathematical model that formulates human pointing motions affected by a large pointer. Our idea is to describe the effect of the large pointer as human visual perception, because the user will perceive the pointer-target distance as being shorter than it actually is. We embedded this scheme, referred to as non-linear distance filter (NDF), into a typical feedback loop model designed to formulate human pointing motions. We also proposed a method to estimate NDF mapping from pointing trajectories, and used it to investigate the applicability of the model under three typical disturbance patterns: small vibration, smooth shift, and step signal. Experimental results demonstrated that the proposed NDF-based model could accurately reproduced actual pointing trajectories, achieving high similarity values of 0.89, 0.97, and 0.91 for the three respective disturbance patterns. The results indicate the applicability of the proposed method. In addition, we confirmed that the obtained NDF mappings suggested rationales for why a large pointer helps facilitate easy pointing.

1161-1180hit(16314hit)