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1741-1760hit(16314hit)

  • VHDL vs. SystemC: Design of Highly Parameterizable Artificial Neural Networks

    David ALEDO  Benjamin CARRION SCHAFER  Félix MORENO  

     
    PAPER-Computer System

      Pubricized:
    2018/11/29
      Vol:
    E102-D No:3
      Page(s):
    512-521

    This paper describes the advantages and disadvantages observed when describing complex parameterizable Artificial Neural Networks (ANNs) at the behavioral level using SystemC and at the Register Transfer Level (RTL) using VHDL. ANNs are complex to parameterize because they have a configurable number of layers, and each one of them has a unique configuration. This kind of structure makes ANNs, a priori, challenging to parameterize using Hardware Description Languages (HDL). Thus, it seems intuitively that ANNs would benefit from the raise in level of abstraction from RTL to behavioral level. This paper presents the results of implementing an ANN using both levels of abstractions. Results surprisingly show that VHDL leads to better results and allows a much higher degree of parameterization than SystemC. The implementation of these parameterizable ANNs are made open source and are freely available online. Finally, at the end of the paper we make some recommendation for future HLS tools to improve their parameterization capabilities.

  • Modification of Velvet Noise for Speech Waveform Generation by Using Vocoder-Based Speech Synthesizer Open Access

    Masanori MORISE  

     
    LETTER-Speech and Hearing

      Pubricized:
    2018/12/05
      Vol:
    E102-D No:3
      Page(s):
    663-665

    This paper introduces a new noise generation algorithm for vocoder-based speech waveform generation. White noise is generally used for generating an aperiodic component. Since short-term white noise includes a zero-frequency component (ZFC) and inaudible components below 20 Hz, they are reduced in advance when synthesizing. We propose a new noise generation algorithm based on that for velvet noise to overcome the problem. The objective evaluation demonstrated that the proposed algorithm can reduce the unwanted components.

  • A 6th-Order Quadrature Bandpass Delta Sigma AD Modulator Using Dynamic Amplifier and Noise Coupling SAR Quantizer

    Chunhui PAN  Hao SAN  

     
    PAPER

      Vol:
    E102-A No:3
      Page(s):
    507-517

    This paper presents a 6th-order quadrature bandpass delta sigma AD modulator (QBPDSM) with 2nd-order image rejection using dynamic amplifier and noise coupling (NC) SAR quantizer embedded by passive adder for the application of wireless communication system. A novel complex integrator using dynamic amplifier is proposed to improve the energy efficiency of the QBPDSM. The NC SAR quantizer can realize an additional 2nd-order noise shaping and 2nd-order image rejection by the digital domain noise coupling technique. As a result, the 6th-order QBPDSM with 2nd-order image rejection is realized by two complex integrators using dynamic amplifier and the NC SAR quantizer. The SPICE simulation results demonstrate the feasibility of the proposed QBPDSM in 90nm CMOS technology. Simulated SNDR of 76.30dB is realized while a sinusoid -3.25dBFS input is sampled at 33.3MS/s and the bandwidth of 2.083MHz (OSR=8) is achieved. The total power consumption in the modulator is 6.74mW while the supply voltage is 1.2V.

  • Quantum Information Processing with Superconducting Nanowire Single-Photon Detectors Open Access

    Takashi YAMAMOTO  

     
    INVITED PAPER

      Vol:
    E102-C No:3
      Page(s):
    224-229

    Superconducting nanowire single-photon detector(SNSPD) has been one of the important ingredients for photonic quantum information processing (QIP). In order to see the potential of SNSPDs, I briefly review recent progresses of the photonic QIP with SNSPDs implemented for various purposes and present a possible direction for the development of SNSPDs.

  • Low-Complexity Joint Antenna and User Selection Scheme for the Downlink Multiuser Massive MIMO System with Complexity Reduction Factors

    Aye Mon HTUN  Maung SANN MAW  Iwao SASASE  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2018/08/29
      Vol:
    E102-B No:3
      Page(s):
    592-602

    Multiuser massive multi-input multi-output (MU massive MIMO) is considered as a promising technology for the fifth generation (5G) of the wireless communication system. In this paper, we propose a low-complexity joint antenna and user selection scheme with block diagonalization (BD) precoding for MU massive MIMO downlink channel in the time division duplex (TDD) system. The base station (BS) is equipped with a large-scale transmit antenna array while each user is using the single receive antenna in the system. To reduce the hardware cost, BS will be implemented by limited number of radio frequency (RF) chains and BS must activate some selected transmit antennas in the BS side for data transmitting and some users' receive antennas in user side for data receiving. To achieve the reduction in the computation complexity in the antenna and user selection while maintaining the same or higher sum-rate in the system, the proposed scheme relies on three complexity reduction key factors. The first key factor is that finding the average channel gains for the transmit antenna in the BS side and the receive antenna in the user side to select the best channel gain antennas and users. The second key factor called the complexity control factor ξ(Xi) for the antenna set and the user set limitation is used to control the complexity of the brute force search. The third one is that using the assumption of the point-to-point deterministic MIMO channel model to avoid the singular value decomposition (SVD) computation in the brute force search. We show that the proposed scheme offers enormous reduction in the computation complexity while ensuring the acceptable performance in terms of total system sum-rate compared with optimal and other conventional schemes.

  • Simplified User Grouping Algorithm for Massive MIMO on Sparse Beam-Space Channels

    Maliheh SOLEIMANI  Mahmood MAZROUEI-SEBDANI  Robert C. ELLIOTT  Witold A. KRZYMIEŃ  Jordan MELZER  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2018/09/13
      Vol:
    E102-B No:3
      Page(s):
    623-631

    Massive multiple-input multiple-output (MIMO) systems are a key promising technology for future broadband cellular networks. The propagation paths within massive MIMO radio channels are often sparse, both in the sub-6GHz frequency band and at millimeter wave frequencies. Herein, we propose a two-layer beamforming scheme for downlink transmission over massive multiuser MIMO sparse beam-space channels. The first layer employs a bipartite graph to dynamically group users in the beam-space domain; the aim is to minimize inter-user interference while significantly reducing the effective channel dimensionality. The second layer performs baseband linear MIMO precoding to maximize spatial multiplexing gain and system throughput. Simulation results demonstrate the proposed two-layer beamforming scheme outperforms other, more conventional algorithms.

  • Bandwidth-Efficient Blind Nonlinear Compensation of RF Receiver Employing Folded-Spectrum Sub-Nyquist Sampling Technique Open Access

    Kan KIMURA  Yasushi YAMAO  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2018/09/14
      Vol:
    E102-B No:3
      Page(s):
    632-640

    Blind nonlinear compensation for RF receivers is an important research topic in 5G mobile communication, in which higher level modulation schemes are employed more often to achieve high capacity and ultra-broadband services. Since nonlinear compensation circuits must handle intermodulation bandwidths that are more than three times the signal bandwidth, reducing the sampling frequency is essential for saving power consumption. This paper proposes a novel blind nonlinear compensation technique that employs sub-Nyquist sampling analog-to-digital conversion. Although outband distortion spectrum is folded in the proposed sub-Nyquist sampling technique, determination of compensator coefficients is still possible by using the distortion power. Proposed technique achieves almost same compensation performance in EVM as the conventional compensation scheme, while reducing sampling speed of analog to digital convertor (ADC) to less than half the normal sampling frequency. The proposed technique can be applied in concurrent dual-band communication systems and adapt to flat Rayleigh fading environments.

  • A Foreground-Background-Based CTU λ Decision Algorithm for HEVC Rate Control of Surveillance Videos

    Zhenglong YANG  Guozhong WANG  GuoWei TENG  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2018/12/18
      Vol:
    E102-D No:3
      Page(s):
    670-674

    Although HEVC rate control can achieve high coding efficiency, it still does not fully utilize the special characteristics of surveillance videos, which typically have a moving foreground and relatively static background. For surveillance videos, it is usually necessary to provide a better coding quality of the moving foreground. In this paper, a foreground-background CTU λ separate decision scheme is proposed. First, low-complexity pixel-based segmentation is presented to obtain the foreground and the background. Second, the rate distortion (RD) characteristics of the foreground and the background are explored. With the rate distortion optimization (RDO) process, the average CTU λ value of the foreground or the background should be equal to the frame λ. Then, a separate optimal CTU λ decision is proposed with a separate λ clipping method. Finally, a separate updating process is used to obtain reasonable parameters for the foreground and the background. The experimental results show that the quality of the foreground is improved by 0.30 dB in the random access configuration and 0.45 dB in the low delay configuration without degradation of either the rate control accuracy or whole frame quality.

  • Designing and Implementing an Enhanced Bluetooth Low Energy Scanner with User-Level Channel Awareness and Simultaneous Channel Scanning

    Sangwook BAK  Young-Joo SUH  

     
    LETTER-Information Network

      Pubricized:
    2018/12/17
      Vol:
    E102-D No:3
      Page(s):
    640-644

    This paper proposes an enhanced BLE scanner with user-level channel awareness and simultaneous channel scanning to increase theoretical scanning capability by up to three times. With better scanning capability, channel analysis quality also has been improved by considering channel-specific signal characteristics, without the need of beacon-side changes.

  • Millimeter-Wave InSAR Target Recognition with Deep Convolutional Neural Network

    Yilu MA  Yuehua LI  

     
    LETTER-Pattern Recognition

      Pubricized:
    2018/11/26
      Vol:
    E102-D No:3
      Page(s):
    655-658

    Target recognition in Millimeter-wave Interferometric Synthetic Aperture Radiometer (MMW InSAR) imaging is always a crucial task. However, the recognition performance of conventional algorithms degrades when facing unpredictable noise interference in practical scenarios and information-loss caused by inverse imaging processing of InSAR. These difficulties make it very necessary to develop general-purpose denoising techniques and robust feature extractors for InSAR target recognition. In this paper, we propose a denoising convolutional neural network (D-CNN) and demonstrate its advantage on MMW InSAR automatic target recognition problem. Instead of directly feeding the MMW InSAR image to the CNN, the proposed algorithm utilizes the visibility function samples as the input of the fully connected denoising layer and recasts the target recognition as a data-driven supervised learning task, which learns the robust feature representations from the space-frequency domain. Comparing with traditional methods which act on the MMW InSAR output images, the D-CNN will not be affected by information-loss accused by inverse imaging process. Furthermore, experimental results on the simulated MMW InSAR images dataset illustrate that the D-CNN has superior immunity to noise, and achieves an outstanding performance on the recognition task.

  • Software Engineering Data Analytics: A Framework Based on a Multi-Layered Abstraction Mechanism

    Chaman WIJESIRIWARDANA  Prasad WIMALARATNE  

     
    LETTER-Software Engineering

      Pubricized:
    2018/12/04
      Vol:
    E102-D No:3
      Page(s):
    637-639

    This paper presents a concept of a domain-specific framework for software analytics by enabling querying, modeling, and integration of heterogeneous software repositories. The framework adheres to a multi-layered abstraction mechanism that consists of domain-specific operators. We showcased the potential of this approach by employing a case study.

  • Superconducting Digital Electronics for Controlling Quantum Computing Systems Open Access

    Nobuyuki YOSHIKAWA  

     
    INVITED PAPER

      Vol:
    E102-C No:3
      Page(s):
    217-223

    The recent rapid increase in the scale of superconducting quantum computing systems greatly increases the demand for qubit control by digital circuits operating at qubit temperatures. In this paper, superconducting digital circuits, such as single-flux quantum and adiabatic quantum flux parametron circuits are described, that are promising candidates for this purpose. After estimating their energy consumption and speed, a conceptual overview of the superconducting electronics for controlling a multiple-qubit system is provided, as well as some of its component circuits.

  • BMM: A Binary Metaheuristic Mapping Algorithm for Mesh-Based Network-on-Chip

    Xilu WANG  Yongjun SUN  Huaxi GU  

     
    LETTER-Fundamentals of Information Systems

      Pubricized:
    2018/11/26
      Vol:
    E102-D No:3
      Page(s):
    628-631

    The mapping optimization problem in Network-on-Chip (NoC) is constraint and NP-hard, and the deterministic algorithms require considerable computation time to find an exact optimal mapping solution. Therefore, the metaheuristic algorithms (MAs) have attracted great interests of researchers. However, most MAs are designed for continuous problems and suffer from premature convergence. In this letter, a binary metaheuristic mapping algorithm (BMM) with a better exploration-exploitation balance is proposed to solve the mapping problem. The binary encoding is used to extend the MAs to the constraint problem and an adaptive strategy is introduced to combine Sine Cosine Algorithm (SCA) and Particle Swarm Algorithm (PSO). SCA is modified to explore the search space effectively, while the powerful exploitation ability of PSO is employed for the global optimum. A set of well-known applications and large-scale synthetic cores-graphs are used to test the performance of BMM. The results demonstrate that the proposed algorithm can improve the energy consumption more significantly than some other heuristic algorithms.

  • Multi-View Synthesis and Analysis Dictionaries Learning for Classification

    Fei WU  Xiwei DONG  Lu HAN  Xiao-Yuan JING  Yi-mu JI  

     
    LETTER-Pattern Recognition

      Pubricized:
    2018/11/27
      Vol:
    E102-D No:3
      Page(s):
    659-662

    Recently, multi-view dictionary learning technique has attracted lots of research interest. Although several multi-view dictionary learning methods have been addressed, they can be further improved. Most of existing multi-view dictionary learning methods adopt the l0 or l1-norm sparsity constraint on the representation coefficients, which makes the training and testing phases time-consuming. In this paper, we propose a novel multi-view dictionary learning approach named multi-view synthesis and analysis dictionaries learning (MSADL), which jointly learns multiple discriminant dictionary pairs with each corresponding to one view and containing a structured synthesis dictionary and a structured analysis dictionary. MSADL utilizes synthesis dictionaries to achieve class-specific reconstruction and uses analysis dictionaries to generate discriminative code coefficients by linear projection. Furthermore, we design an uncorrelation term for multi-view dictionary learning, such that the redundancy among synthesis dictionaries learned from different views can be reduced. Two widely used datasets are employed as test data. Experimental results demonstrate the efficiency and effectiveness of the proposed approach.

  • BER Performance of Human Body Communications Using FSDT

    Kunho PARK  Min Joo JEONG  Jong Jin BAEK  Se Woong KIM  Youn Tae KIM  

     
    PAPER-Network

      Pubricized:
    2018/08/23
      Vol:
    E102-B No:3
      Page(s):
    522-527

    This paper presents the bit error rate (BER) performance of human body communication (HBC) receivers in interference-rich environments. The BER performance was measured while applying an interference signal to the HBC receiver to consider the effect of receiver performance on BER performance. During the measurement, a signal attenuator was used to mimic the signal loss of the human body channel, which improved the repeatability of the measurement results. The measurement results showed that HBC is robust against the interference when frequency selective digital transmission (FSDT) is used as a modulation scheme. The BER performance in this paper can be effectively used to evaluate a communication performance of HBC.

  • Generation of Efficient Obfuscated Code through Just-in-Time Compilation

    Muhammad HATABA  Ahmed EL-MAHDY  Kazunori UEDA  

     
    LETTER-Dependable Computing

      Pubricized:
    2018/11/22
      Vol:
    E102-D No:3
      Page(s):
    645-649

    Nowadays the computing technology is going through a major paradigm shift. Local processing platforms are being replaced by physically out of reach yet more powerful and scalable environments such as the cloud computing platforms. Previously, we introduced the OJIT system as a novel approach for obfuscating remotely executed programs, making them difficult for adversaries to reverse-engineer. The system exploited the JIT compilation technology to randomly and dynamically transform the code, making it constantly changing, thereby complicating the execution state. This work aims to propose the new design iOJIT, as an enhanced approach that patches the old systems shortcomings, and potentially provides more effective obfuscation. Here, we present an analytic study of the obfuscation techniques on the generated code and the cost of applying such transformations in terms of execution time and performance overhead. Based upon this profiling study, we implemented a new algorithm to choose which obfuscation techniques would be better chosen for “efficient” obfuscation according to our metrics, i.e., less prone to security attacks. Another goal was to study the system performance with different applications. Therefore, we applied our system on a cloud platform running different standard benchmarks from SPEC suite.

  • Recursive Nearest Neighbor Graph Partitioning for Extreme Multi-Label Learning

    Yukihiro TAGAMI  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2018/11/30
      Vol:
    E102-D No:3
      Page(s):
    579-587

    As the data size of Web-related multi-label classification problems continues to increase, the label space has also grown extremely large. For example, the number of labels appearing in Web page tagging and E-commerce recommendation tasks reaches hundreds of thousands or even millions. In this paper, we propose a graph partitioning tree (GPT), which is a novel approach for extreme multi-label learning. At an internal node of the tree, the GPT learns a linear separator to partition a feature space, considering approximate k-nearest neighbor graph of the label vectors. We also developed a simple sequential optimization procedure for learning the linear binary classifiers. Extensive experiments on large-scale real-world data sets showed that our method achieves better prediction accuracy than state-of-the-art tree-based methods, while maintaining fast prediction.

  • Recognition of Collocation Frames from Sentences

    Xiaoxia LIU  Degen HUANG  Zhangzhi YIN  Fuji REN  

     
    PAPER-Natural Language Processing

      Pubricized:
    2018/12/14
      Vol:
    E102-D No:3
      Page(s):
    620-627

    Collocation is a ubiquitous phenomenon in languages and accurate collocation recognition and extraction is of great significance to many natural language processing tasks. Collocations can be differentiated from simple bigram collocations to collocation frames (referring to distant multi-gram collocations). So far little focus is put on collocation frames. Oriented to translation and parsing, this study aims to recognize and extract the longest possible collocation frames from given sentences. We first extract bigram collocations with distributional semantics based method by introducing collocation patterns and integrating some state-of-the-art association measures. Based on bigram collocations extracted by the proposed method, we get the longest collocation frames according to recursive nature and linguistic rules of collocations. Compared with the baseline systems, the proposed method performs significantly better in bigram collocation extraction both in precision and recall. And in extracting collocation frames, the proposed method performs even better with the precision similar to its bigram collocation extraction results.

  • Object Tracking by Unified Semantic Knowledge and Instance Features

    Suofei ZHANG  Bin KANG  Lin ZHOU  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2018/11/30
      Vol:
    E102-D No:3
      Page(s):
    680-683

    Instance features based deep learning methods prompt the performances of high speed object tracking systems by directly comparing target with its template during training and tracking. However, from the perspective of human vision system, prior knowledge of target also plays key role during the process of tracking. To integrate both semantic knowledge and instance features, we propose a convolutional network based object tracking framework to simultaneously output bounding boxes based on different prior knowledge as well as confidences of corresponding Assumptions. Experimental results show that our proposed approach retains both higher accuracy and efficiency than other leading methods on tracking tasks covering most daily objects.

  • Fabrication and Evaluation of Integrated Photonic Array-Antenna System for RoF Based Remote Antenna Beam Forming

    Takayoshi HIRASAWA  Shigeyuki AKIBA  Jiro HIROKAWA  Makoto ANDO  

     
    PAPER-Lasers, Quantum Electronics

      Vol:
    E102-C No:3
      Page(s):
    235-242

    This paper studies the performance of the quantitative RF power variation in Radio-over-Fiber beam forming system utilizing a phased array-antenna integrating photo-diodes in downlink network for next generation millimeter wave band radio access. Firstly, we described details of fabrication of an integrated photonic array-antenna (IPA), where a 60GHz patch antenna 4×2 array and high-speed photo-diodes were integrated into a substrate. We evaluated RF transmission efficiency as an IPA system for Radio-over-Fiber (RoF)-based mobile front hall architecture with remote antenna beam forming capability. We clarified the characteristics of discrete and integrated devices such as an intensity modulator (IM), an optical fiber and the IPA and calculated RF power radiated from the IPA taking account of the measured data of the devices. Based on the experimental results on RF tone signal transmission by utilizing the IPA, attainable transmission distance of wireless communication by improvement and optimization of the used devices was discussed. We deduced that the antenna could output sufficient power when we consider that the cell size of the future mobile communication systems would be around 100 meters or smaller.

1741-1760hit(16314hit)