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[Keyword] OMP(3945hit)

301-320hit(3945hit)

  • New Construction of Even-Length Binary Z-Complementary Pairs with Low PAPR Open Access

    Zhi GU  Yong WANG  Yang YANG  

     
    LETTER-Coding Theory

      Vol:
    E104-A No:2
      Page(s):
    412-416

    This paper is focused on constructing even-length binary Z-complementary pairs (EB-ZCPs) with new length. Inspired by a recent work of Adhikary et al., we give a construction of EB-ZCPs with length 8N+4 (where N=2α 10β 26γ and α, β, γ are nonnegative integers) and zero correlation zone (ZCZ) width 5N+2. The maximum aperiodic autocorrelation sums (AACS) magnitude of the proposed sequences outside the ZCZ region is 8. It turns out that the generated sequences have low PAPR.

  • A Differential on Chip Oscillator with 1.47-μs Startup Time and 3.3-ppm/°C Temperature Coefficient of Frequency

    Guoqiang ZHANG  Lingjin CAO  Kosuke YAYAMA  Akio KATSUSHIMA  Takahiro MIKI  

     
    PAPER

      Vol:
    E104-A No:2
      Page(s):
    499-505

    A differential on chip oscillator (OCO) is proposed in this paper for low supply voltage, high frequency accuracy and fast startup. The differential architecture helps the OCO achieve a good power supply rejection ratio (PSRR) without using a regulator so as to make the OCO suitable for a low power supply voltage of 1.38V. A reference voltage generator is also developed to generate two output voltages lower than Vbe for low supply voltage operation. The output frequency is locked to 48MHz by a frequency-locked loop (FLL) and a 3.3-ppm/°C temperature coefficient of frequency is realized by the differential voltage ratio adjusting (differential VRA) technique. The startup time is only 1.47μs because the differential OCO is not necessary to charge a big capacitor for ripple reduction.

  • Learning Rule for a Quantum Neural Network Inspired by Hebbian Learning

    Yoshihiro OSAKABE  Shigeo SATO  Hisanao AKIMA  Mitsunaga KINJO  Masao SAKURABA  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2020/10/30
      Vol:
    E104-D No:2
      Page(s):
    237-245

    Utilizing the enormous potential of quantum computers requires new and practical quantum algorithms. Motivated by the success of machine learning, we investigate the fusion of neural and quantum computing, and propose a learning method for a quantum neural network inspired by the Hebb rule. Based on an analogy between neuron-neuron interactions and qubit-qubit interactions, the proposed quantum learning rule successfully changes the coupling strengths between qubits according to training data. To evaluate the effectiveness and practical use of the method, we apply it to the memorization process of a neuro-inspired quantum associative memory model. Our numerical simulation results indicate that the proposed quantum versions of the Hebb and anti-Hebb rules improve the learning performance. Furthermore, we confirm that the probability of retrieving a target pattern from multiple learned patterns is sufficiently high.

  • A Phase Retrieval Method with Probe-Positioning Error Compensation for Phaseless Near-Field Measurements

    Yoshiki SUGIMOTO  Hiroyuki ARAI  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2020/07/14
      Vol:
    E104-B No:1
      Page(s):
    55-63

    The phaseless antenna measurement technique is advantageous for high-frequency near-field measurements in which the uncertainty of the measured phase is a problem. In the phaseless measurement, which is expected to be used in the frequency band with a short wavelength, a slight positional deviation error of the probe greatly deteriorates the measurement result. This paper proposes a phase retrieval method that can compensate the measurement errors caused by misalignment of a probe and its jig. And this paper proposes a far-field estimation method by phase resurrection that incorporated the compensation techniques. We find that the positioning errors are due to the random errors occurring at each measurement point because of minute vibrations of the probe; in addition, we determine that the stationary depth errors occurring at each measurement surface as errors caused by improper setting of the probe jig. The random positioning error is eliminated by adding a low-pass filter in wavenumber space, and the depth positioning error is iteratively compensated on the basis of the relative residual obtained in each plane. The validity of the proposed method is demonstrated by estimating the far-field patterns using the results from numerical simulations, and is also demonstrated using measurement data with probe-positioning error. The proposed method can reduce the probe-positioning error and improve the far-field estimation accuracy by more over than 10 dB.

  • Efficient Algorithms for Sign Detection in RNS Using Approximate Reciprocals Open Access

    Shinichi KAWAMURA  Yuichi KOMANO  Hideo SHIMIZU  Saki OSUKA  Daisuke FUJIMOTO  Yuichi HAYASHI  Kentaro IMAFUKU  

     
    PAPER

      Vol:
    E104-A No:1
      Page(s):
    121-134

    The residue number system (RNS) is a method for representing an integer x as an n-tuple of its residues with respect to a given set of moduli. In RNS, addition, subtraction, and multiplication can be carried out by independent operations with respect to each modulus. Therefore, an n-fold speedup can be achieved by parallel processing. The main disadvantage of RNS is that we cannot efficiently compare the magnitude of two integers or determine the sign of an integer. Two general methods of comparison are to transform a number in RNS to a mixed-radix system or to a radix representation using the Chinese remainder theorem (CRT). We used the CRT to derive an equation approximating a value of x relative to M, the product of moduli. Then, we propose two algorithms that efficiently evaluate the equation and output a sign bit. The expected number of steps of these algorithms is of order n. The algorithms use a lookup table that is (n+3) times as large as M, which is reasonably small for most applications including cryptography.

  • A Compact RTD-Based Push-Push Oscillator Using a Symmetrical Spiral Inductor

    Kiwon LEE  Yongsik JEONG  

     
    BRIEF PAPER-Microwaves, Millimeter-Waves

      Pubricized:
    2020/07/09
      Vol:
    E104-C No:1
      Page(s):
    37-39

    In this paper, a compact microwave push-push oscillator based on a resonant tunneling diode (RTD) has been fabricated and demonstrated. A symmetrical spiral inductor structure has been used in order to reduce a chip area. The designed symmetric inductor is integrated into the InP-based RTD monolithic microwave integrated circuit (MMIC) technology. The circuit occupies a compact active area of 0.088 mm2 by employing symmetric inductor. The fabricated RTD oscillator shows an extremely low DC power consumption of 87 µW at an applied voltage of 0.47 V with good figure-of-merit (FOM) of -191 dBc/Hz at an oscillation frequency of 27 GHz. This is the first implementation as the RTD push-push oscillator with the symmetrical spiral inductor.

  • Iterative Carrier Frequency Offset Estimation with Independent Component Analysis in BLE Systems

    Masahiro TAKIGAWA  Takumi TAKAHASHI  Shinsuke IBI  Seiichi SAMPEI  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2020/07/14
      Vol:
    E104-B No:1
      Page(s):
    88-98

    This paper proposes iterative carrier frequency offset (CFO) compensation for spatially multiplexed Bluetooth Low Energy (BLE) signals using independent component analysis (ICA). We apply spatial division multiple access (SDMA) to BLE system to deal with massive number of connection requests of BLE devices expected in the future. According to specifications, each BLE peripheral device is assumed to have CFO of up to 150 [kHz] due to hardware impairments. ICA can resolve spatially multiplexed signals even if they include independent CFO. After the ICA separation, the proposed scheme compensates for the CFO. However, the length of the BLE packet preamble is not long enough to obtain accurate CFO estimates. In order to accurately conduct the CFO compensation using the equivalent of a long pilot signal, preamble and a part of estimated data in the previous process are utilized. In addition, we reveal the fact that the independent CFO of each peripheral improves the capability of ICA blind separation. The results confirm that the proposed scheme can effectively compensate for CFO in the range of up to 150[kHz], which is defined as the acceptable value in the BLE specification.

  • A Novel Multi-Knowledge Distillation Approach

    Lianqiang LI  Kangbo SUN  Jie ZHU  

     
    LETTER-Artificial Intelligence, Data Mining

      Pubricized:
    2020/10/19
      Vol:
    E104-D No:1
      Page(s):
    216-219

    Knowledge distillation approaches can transfer information from a large network (teacher network) to a small network (student network) to compress and accelerate deep neural networks. This paper proposes a novel knowledge distillation approach called multi-knowledge distillation (MKD). MKD consists of two stages. In the first stage, it employs autoencoders to learn compact and precise representations of the feature maps (FM) from the teacher network and the student network, these representations can be treated as the essential of the FM, i.e., EFM. In the second stage, MKD utilizes multiple kinds of knowledge, i.e., the magnitude of individual sample's EFM and the similarity relationships among several samples' EFM to enhance the generalization ability of the student network. Compared with previous approaches that employ FM or the handcrafted features from FM, the EFM learned from autoencoders can be transferred more efficiently and reliably. Furthermore, the rich information provided by the multiple kinds of knowledge guarantees the student network to mimic the teacher network as closely as possible. Experimental results also show that MKD is superior to the-state-of-arts.

  • Mitigation of Flash Crowd in Web Services By Providing Feedback Information to Users

    Harumasa TADA  Masayuki MURATA  Masaki AIDA  

     
    PAPER

      Pubricized:
    2020/09/18
      Vol:
    E104-D No:1
      Page(s):
    63-75

    The term “flash crowd” describes a situation in which a large number of users access a Web service simultaneously. Flash crowds, in particular, constitute a critical problem in e-commerce applications because of the potential for enormous economic damage as well as difficulty in management. Flash crowds can become more serious depending on users' behavior. When a flash crowd occurs, the delay in server response may cause users to retransmit their requests, thereby adding to the server load. In the present paper, we propose to use the psychological factors of the users for flash crowd mitigation. We aim to analyze changes in the user behavior by presenting feedback information. To evaluate the proposed method, we performed subject experiments and stress tests. Subject experiments showed that, by providing feedback information, the average number of request retransmissions decreased from 1.33 to 0.09, and the subjects that abandoned the service decreased from 81% to 0%. This confirmed that feedback information is effective in influencing user behavior in terms of abandonment and retransmission of requests. Stress tests showed that the average number of retransmissions decreased by 41%, and the proportion of abandonments decreased by 30%. These results revealed that the presentation of feedback information could mitigate the damage caused by flash crowds in real websites, although the effect is limited. The proposed method can be used in conjunction with conventional methods to handle flash crowds.

  • IND-CCA1 Secure FHE on Non-Associative Ring

    Masahiro YAGISAWA  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2020/07/08
      Vol:
    E104-A No:1
      Page(s):
    275-282

    A fully homomorphic encryption (FHE) would be the important cryptosystem as the basic scheme for the cloud computing. Since Gentry discovered in 2009 the first fully homomorphic encryption scheme, some fully homomorphic encryption schemes were proposed. In the systems proposed until now the bootstrapping process is the main bottleneck and the large complexity for computing the ciphertext is required. In 2011 Zvika Brakerski et al. proposed a leveled FHE without bootstrapping. But circuit of arbitrary level cannot be evaluated in their scheme while in our scheme circuit of any level can be evaluated. The existence of an efficient fully homomorphic cryptosystem would have great practical implications in the outsourcing of private computations, for instance, in the field of the cloud computing. In this paper, IND-CCA1secure FHE based on the difficulty of prime factorization is proposed which does not need the bootstrapping and it is thought that our scheme is more efficient than the previous schemes. In particular the computational overhead for homomorphic evaluation is O(1).

  • Quantitative Evaluation of Software Component Behavior Discovery Approach

    Cong LIU  

     
    LETTER

      Pubricized:
    2020/05/21
      Vol:
    E104-D No:1
      Page(s):
    117-120

    During the execution of software systems, their execution data can be recorded. By fully exploiting these data, software practitioners can discover behavioral models describing the actual execution of the underlying software system. The recorded unstructured software execution data may be too complex, spanning over several days, etc. Applying existing discovery techniques results in spaghetti-like models with no clear structure and no valuable information for comprehension. Starting from the observation that a software system is composed of a set of logical components, Liu et al. propose to decompose the software behavior discovery problem into smaller independent ones by discovering a behavioral model per component in [1]. However, the effectiveness of the proposed approach is not fully evaluated and compared with existing approaches. In this paper, we evaluate the quality (in terms of understandability/complexity) of discovered component behavior models in a quantitative manner. Based on evaluation, we show that this approach can reduce the complexity of the discovered model and gives a better understanding.

  • Load Balancing for Energy-Harvesting Mobile Edge Computing

    Ping ZHAO  Jiawei TAO  Abdul RAUF  Fengde JIA  Longting XU  

     
    LETTER-Mobile Information Network and Personal Communications

      Pubricized:
    2020/07/27
      Vol:
    E104-A No:1
      Page(s):
    336-342

    With the development of cloud computing, the Mobile Edge Computing has emerged and attracted widespread attentions. In this paper, we focus on the load balancing in MEC with energy harvesting. We first introduce the load balancing in MEC as a problem of minimizing both the energy consumption and queue redundancy. Thereafter, we adapt such a optimization problem to the Lyapunov algorithm and solve this optimization problem. Finally, extensive simulation results validate that the obtained strategy improves the capabilities of MEC systems.

  • A Scheme of Reversible Data Hiding for the Encryption-Then-Compression System

    Masaaki FUJIYOSHI  Ruifeng LI  Hitoshi KIYA  

     
    PAPER

      Pubricized:
    2020/10/21
      Vol:
    E104-D No:1
      Page(s):
    43-50

    This paper proposes an encryption-then-compression (EtC) system-friendly data hiding scheme for images, where an EtC system compresses images after they are encrypted. The EtC system divides an image into non-overlapping blocks and applies four block-based processes independently and randomly to the image for visual encryption of the image. The proposed scheme hides data to a plain, i.e., unencrypted image and the scheme can take hidden data out from the image encrypted by the EtC system. Furthermore, the scheme serves reversible data hiding, so it can perfectly recover the unmarked image from the marked image whereas the scheme once distorts unmarked image for hiding data to the image. The proposed scheme copes with the three of four processes in the EtC system, namely, block permutation, rotation/flipping of blocks, and inverting brightness in blocks, whereas the conventional schemes for the system do not cope with the last one. In addition, these conventional schemes have to identify the encrypted image so that image-dependent side information can be used to extract embedded data and to restore the unmarked image, but the proposed scheme does not need such identification. Moreover, whereas the data hiding process must know the block size of encryption in conventional schemes, the proposed scheme needs no prior knowledge of the block size for encryption. Experimental results show the effectiveness of the proposed scheme.

  • Analysis of Work Efficiency and Quality of Software Maintenance Using Cross-Company Dataset

    Masateru TSUNODA  Akito MONDEN  Kenichi MATSUMOTO  Sawako OHIWA  Tomoki OSHINO  

     
    PAPER

      Pubricized:
    2020/08/31
      Vol:
    E104-D No:1
      Page(s):
    76-90

    Software maintenance is an important activity in the software lifecycle. Software maintenance does not only mean removing faults found after software release. Software needs extensions or modifications of its functions owing to changes in the business environment and software maintenance also refers to them. To help users and service suppliers benchmark work efficiency for software maintenance, and to clarify the relationships between software quality, work efficiency, and unit cost of staff, we used a dataset that includes 134 data points collected by the Economic Research Association in 2012, and analyzed the factors that affected the work efficiency of software maintenance. In the analysis, using a multiple regression model, we clarified the relationships between work efficiency and programming language and productivity factors. To analyze the influence to the quality, relationships of fault ratio was analyzed using correlation coefficients. The programming language and productivity factors affect work efficiency. Higher work efficiency and higher unit cost of staff do not affect the quality of software maintenance.

  • Application Mapping and Scheduling of Uncertain Communication Patterns onto Non-Random and Random Network Topologies

    Yao HU  Michihiro KOIBUCHI  

     
    PAPER-Computer System

      Pubricized:
    2020/07/20
      Vol:
    E103-D No:12
      Page(s):
    2480-2493

    Due to recent technology progress based on big-data processing, many applications present irregular or unpredictable communication patterns among compute nodes in high-performance computing (HPC) systems. Traditional communication infrastructures, e.g., torus or fat-tree interconnection networks, may not handle well their matchmaking problems with these newly emerging applications. There are already many communication-efficient application mapping algorithms for these typical non-random network topologies, which use nearby compute nodes to reduce the network distances. However, for the above unpredictable communication patterns, it is difficult to efficiently map their applications onto the non-random network topologies. In this context, we recommend using random network topologies as the communication infrastructures, which have drawn increasing attention for the use of HPC interconnects due to their small diameter and average shortest path length (ASPL). We make a comparative study to analyze the impact of application mapping performance on non-random and random network topologies. We propose using topology embedding metrics, i.e., diameter and ASPL, and list several diameter/ASPL-based application mapping algorithms to compare their job scheduling performances, assuming that the communication pattern of each application is unpredictable to the computing system. Evaluation with a large compound application workload shows that, when compared to non-random topologies, random topologies can reduce the average turnaround time up to 39.3% by a random connected mapping method and up to 72.1% by a diameter/ASPL-based mapping algorithm. Moreover, when compared to the baseline topology mapping method, the proposed diameter/ASPL-based topology mapping strategy can reduce up to 48.0% makespan and up to 78.1% average turnaround time, and improve up to 1.9x system utilization over random topologies.

  • PCA-LDA Based Color Quantization Method Taking Account of Saliency

    Yoshiaki UEDA  Seiichi KOJIMA  Noriaki SUETAKE  

     
    LETTER-Image

      Vol:
    E103-A No:12
      Page(s):
    1613-1617

    In this letter, we propose a color quantization method based on saliency. In the proposed method, the salient colors are selected as representative colors preferentially by using saliency as weights. Through experiments, we verify the effectiveness of the proposed method.

  • Predicting Violence Rating Based on Pairwise Comparison

    Ying JI  Yu WANG  Jien KATO  Kensaku MORI  

     
    PAPER-Data Engineering, Web Information Systems

      Pubricized:
    2020/08/28
      Vol:
    E103-D No:12
      Page(s):
    2578-2589

    With the rapid development of multimedia, violent video can be easily accessed in games, movies, websites, and so on. Identifying violent videos and rating violence extent is of great importance to media filtering and children protection. Many previous studies only address the problems of violence scene detection and violent action recognition, yet violence rating problem is still not solved. In this paper, we present a novel video-level rating prediction method to estimate violence extent automatically. It has two main characteristics: (1) a two-stream network is fine-tuned to construct effective representations of violent videos; (2) a violence rating prediction machine is designed to learn the strength relationship among different videos. Furthermore, we present a novel violent video dataset with a total of 1,930 human-involved violent videos designed for violence rating analysis. Each video is annotated with 6 fine-grained objective attributes, which are considered to be closely related to violence extent. The ground-truth of violence rating is given by pairwise comparison method. The dataset is evaluated in both stability and convergence. Experiment results on this dataset demonstrate the effectiveness of our method compared with the state-of-art classification methods.

  • Battery-Powered Wild Animal Detection Nodes with Deep Learning

    Hiroshi SAITO  Tatsuki OTAKE  Hayato KATO  Masayuki TOKUTAKE  Shogo SEMBA  Yoichi TOMIOKA  Yukihide KOHIRA  

     
    PAPER

      Pubricized:
    2020/07/01
      Vol:
    E103-B No:12
      Page(s):
    1394-1402

    Since wild animals are causing more accidents and damages, it is important to safely detect them as early as possible. In this paper, we propose two battery-powered wild animal detection nodes based on deep learning that can automatically detect wild animals; the detection information is notified to the people concerned immediately. To use the proposed nodes outdoors where power is not available, we devise power saving techniques for the proposed nodes. For example, deep learning is used to save power by avoiding operations when wild animals are not detected. We evaluate the operation time and the power consumption of the proposed nodes. Then, we evaluate the energy consumption of the proposed nodes. Also, we evaluate the detection range of the proposed nodes, the accuracy of deep learning, and the success rate of communication through field tests to demonstrate that the proposed nodes can be used to detect wild animals outdoors.

  • L0 Norm Optimization in Scrambled Sparse Representation Domain and Its Application to EtC System

    Takayuki NAKACHI  Hitoshi KIYA  

     
    PAPER-Cryptography and Information Security

      Vol:
    E103-A No:12
      Page(s):
    1589-1598

    In this paper, we propose L0 norm optimization in a scrambled sparse representation domain and its application to an Encryption-then-Compression (EtC) system. We design a random unitary transform that conserves L0 norm isometry. The resulting encryption method provides a practical orthogonal matching pursuit (OMP) algorithm that allows computation in the encrypted domain. We prove that the proposed method theoretically has exactly the same estimation performance as the nonencrypted variant of the OMP algorithm. In addition, we demonstrate the security strength of the proposed secure sparse representation when applied to the EtC system. Even if the dictionary information is leaked, the proposed scheme protects the privacy information of observed signals.

  • Traffic-Independent Multi-Path Routing for High-Throughput Data Center Networks

    Ryuta KAWANO  Ryota YASUDO  Hiroki MATSUTANI  Michihiro KOIBUCHI  Hideharu AMANO  

     
    PAPER-Computer System

      Pubricized:
    2020/08/06
      Vol:
    E103-D No:12
      Page(s):
    2471-2479

    Network throughput has become an important issue for big-data analysis on Warehouse-Scale Computing (WSC) systems. It has been reported that randomly-connected inter-switch networks can enlarge the network throughput. For irregular networks, a multi-path routing method called k-shortest path routing is conventionally utilized. However, it cannot efficiently exploit longer-than-shortest paths that would be detour paths to avoid bottlenecks. In this work, a novel routing method called k-optimized path routing to achieve high throughput is proposed for irregular networks. We introduce a heuristic to select detour paths that can avoid bottlenecks in the network to improve the average-case network throughput. Experimental results by network simulation show that the proposed k-optimized path routing can improve the saturation throughput by up to 18.2% compared to the conventional k-shortest path routing. Moreover, it can reduce the computation time required for optimization to 1/2760 at a minimum compared to our previously proposed method.

301-320hit(3945hit)