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10261-10280hit(42807hit)

  • Initial (Final) State Estimation in Error-Trellises for Tail-Biting Convolutional Codes

    Masato TAJIMA  Koji OKINO  Tatsuto MURAYAMA  

     
    LETTER-Coding Theory

      Vol:
    E97-A No:3
      Page(s):
    881-887

    In this paper, we clarify the relationship between an initial (final) state in a tail-biting error-trellis and the obtained syndromes. We show that a final state is dependent on the first M syndromes as well, where M is the memory length of the parity-check matrix. Next, we calculate the probability of an initial (final) state conditioned by the syndromes. We also apply this method to concrete examples. It is shown that the initial (final) state in a tail-biting error-trellis is well estimated using these conditional probabilities.

  • Performance Evaluation on RSSI-Based Wireless Capsule Endoscope Location Tracking with Particle Filter

    Takahiro ITO  Daisuke ANZAI  Jianqing WANG  

     
    PAPER

      Vol:
    E97-B No:3
      Page(s):
    579-586

    Tracking capsule endoscope location is one of the promising applications offered by implant body area networks (BANs). When tracking the capsule endoscope location, i.e., continuously localize it, it is effective to take the weighted sum of its past locations to its present location, in other words, to low-pass filter its past locations. Furthermore, creating an exact mathematical model of location transition will improve tracking performance. Therefore, in this paper, we investigate two tracking methods with received signal strength indicator (RSSI)-based localization in order to solve the capsule endoscope location tracking problem. One of the two tracking methods is finite impulse response (FIR) filter-based tracking, which tracks the capsule endoscope location by averaging its past locations. The other one is particle filter-based tracking in order to deal with a nonlinear transition model on the capsule endoscope. However, the particle filter requires that the particle weight is calculated according to its condition (namely, its likelihood value), while the transition model on capsule endoscope location has some model parameters which cannot be estimated from the received wireless signal. Therefore, for the purpose of applying the particle filter to capsule endoscope tracking, this paper makes some modifications in the resampling step of the particle filter algorithm. Our computer simulation results demonstrate that the two tracking methods can improve the performance as compared with the conventional maximum likelihood (ML) localization. Furthermore, we confirm that the particle filter-based tracking outperforms the conventional FIR filter-based tracking by taking the realistic capsule endoscope transition model into consideration.

  • Resolution and Parameter Estimation of Non-ideally Sampled Pulse Signals

    Bo WU  Yan WANG  Xiuying CAO  Pengcheng ZHU  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E97-B No:3
      Page(s):
    647-654

    Attenuated and delayed versions of the pulse signal overlap in multipath propagation. Previous algorithms can resolve them only if signal sampling is ideal, but fail to resolve two counterparts with non-ideal sampling. In this paper, we propose a novel method which can resolve the general types of non-ideally sampled pulse signals in the time domain via Taylor Series Expansion (TSE) and estimate multipath signals' precise time delays and amplitudes. In combination with the CLEAN algorithm, the overlapped pulse signal parameters are estimated one by one through an iteration method. Simulation results verify the effectiveness of the proposed method.

  • Neuron Circuit Using Coupled SQUIDs Gate with Flat Output Characteristics for Superconducting Neural Network

    Takeshi ONOMI  Koji NAKAJIMA  

     
    PAPER

      Vol:
    E97-C No:3
      Page(s):
    173-177

    We propose an improved design of a neuron circuit, using coupled SQUIDs gates, for a superconducting neural network. An activation function with step-like input vs. output characteristics is desirable for a neuron circuit to solve a combinatorial optimization problem. The proposed neuron circuit is composed of two coupled SQUIDs gates with a cascade connection, in order to obtain such characteristics. The designed neuron circuit is fabricated by a 2.5kA/cm2 Nb/AlOx/Nb process. The operation of a fabricated neuron circuit is experimentally demonstrated. Network performance of a neural network using proposed neuron circuits is also estimated by numerical dynamic simulations.

  • Constant Time Enumeration of Subtrees with Exactly k Nodes in a Tree

    Kunihiro WASA  Yusaku KANETA  Takeaki UNO  Hiroki ARIMURA  

     
    PAPER-Graph Algorithms, Knowledge Discovery

      Vol:
    E97-D No:3
      Page(s):
    421-430

    By the motivation to discover patterns in massive structured data in the form of graphs and trees, we study a special case of the k-subtree enumeration problem with a tree of n nodes as an input graph, which is originally introduced by (Ferreira, Grossi, and Rizzi, ESA'11, 275-286, 2011) for general graphs. Based on reverse search technique (Avis and Fukuda, Discrete Appl. Math., vol.65, pp.21-46, 1996), we present the first constant delay enumeration algorithm that lists all k-subtrees of an input rooted tree in O(1) worst-case time per subtree. This result improves on the straightforward application of Ferreira et al.'s algorithm with O(k) amortized time per subtree when an input is restricted to tree. Finally, we discuss an application of our algorithm to a modification of the graph motif problem for trees.

  • Development of Compression Tolerable and Highly Implementable Watermarking Method for Mobile Devices

    Takeshi KUMAKI  Kei NAKAO  Kohei HOZUMI  Takeshi OGURA  Takeshi FUJINO  

     
    LETTER-Information Network

      Vol:
    E97-D No:3
      Page(s):
    593-596

    This paper reports on the image compression tolerability and high implementability of a novel proposed watermarking method that uses a morphological wavelet transform based on max-plus algebra. This algorithm is suitable for embedded low-power processors in mobile devices. For objective and unified evaluation of the capability of the proposed watermarking algorithm, we focus attention on a watermarking contest presented by the IHC, which belongs to the IEICE and investigate the image quality and tolerance against JPEG compression attack. During experiments for this contest, six benchmark images processed by the proposed watermarking is done to reduce the file size of original images to 1/10, 1/20, or less, and the error rate of embedding data is reduced to 0%. Thus, the embedded data can be completely extracted. The PSNR value is up to 54.66dB in these experiments. Furthermore, when the smallest image size is attained 0.49MB and the PSNR value become about 52dB, the proposed algorithm maintains very high quality with an error rate of 0%. Additionally, the processing time of the proposed watermarking can realize about 416.4 and 4.6 times faster than that of DCT and HWT on the ARM processor, respectively. As a result, the proposed watermarking method achieves effective processing capability for mobile processors.

  • Scan Shift Time Reduction Using Test Compaction for On-Chip Delay Measurement

    Wenpo ZHANG  Kazuteru NAMBA  Hideo ITO  

     
    PAPER-Dependable Computing

      Vol:
    E97-D No:3
      Page(s):
    533-540

    In recent VLSIs, small-delay defects, which are hard to detect by traditional delay fault testing, can bring about serious issues such as short lifetime. To detect small-delay defects, on-chip delay measurement which measures the delay time of paths in the circuit under test (CUT) was proposed. However, this approach incurs high test cost because it uses scan design, which brings about long test application time due to scan shift operation. Our solution is a test application time reduction method for testing using the on-chip path delay measurement. The testing with on-chip path delay measurement does not require capture operations, unlike the conventional delay testing. Specifically, FFs keep the transition pattern of the test pattern pair sensitizing a path under measurement (PUM) (denoted as p) even after the measurement of p. The proposed method uses this characteristic. The proposed method reduces scan shift time and test data volume using test pattern merging. Evaluation results on ISCAS89 benchmark circuits indicate that the proposed method reduces the test application time by 6.89∼62.67% and test data volume by 46.39∼74.86%.

  • Confidence Measure Based on Context Consistency Using Word Occurrence Probability and Topic Adaptation for Spoken Term Detection

    Haiyang LI  Tieran ZHENG  Guibin ZHENG  Jiqing HAN  

     
    PAPER-Speech and Hearing

      Vol:
    E97-D No:3
      Page(s):
    554-561

    In this paper, we propose a novel confidence measure to improve the performance of spoken term detection (STD). The proposed confidence measure is based on the context consistency between a hypothesized word and its context in a word lattice. The main contribution of this paper is to compute the context consistency by considering the uncertainty in the results of speech recognition and the effect of topic. To measure the uncertainty of the context, we employ the word occurrence probability, which is obtained through combining the overlapping hypotheses in a word posterior lattice. To handle the effect of topic, we propose a method of topic adaptation. The adaptation method firstly classifies the spoken document according to the topics and then computes the context consistency of the hypothesized word with the topic-specific measure of semantic similarity. Additionally, we apply the topic-specific measure of semantic similarity by two means, and they are performed respectively with the information of the top-1 topic and the mixture of all topics according to topic classification. The experiments conducted on the Hub-4NE Mandarin database show that both the occurrence probability of context word and the topic adaptation are effective for the confidence measure of STD. The proposed confidence measure performs better compared with the one ignoring the uncertainty of the context or the one using a non-topic method.

  • Bitstream-Level Film Noise Cancellation for Damaged Video Playback

    Sinwook LEE  Euee-seon JANG  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E97-D No:3
      Page(s):
    562-572

    In this paper, we propose a bitstream-level noise cancellation method for playback applications of damaged video. Most analog video data such as movies, news and historical research videos are now stored in a digital format after a series of conversion processes that include analog-to-digital conversion and compression. In many cases, noise such as blotches and line scratching remaining in analog media are not removed during the conversion process. On the other hand, noise is propagated in the compression stage because most media compression technologies use predictive coding. Therefore, it is imperative to efficiently remove or reduce the artifacts caused by noise as much as possible. In some cases, the video data with historical values are to be preserved without correcting the noise in order not to lose any important information resulting from the noise removal process. However, playback applications of such video data still need to undergo a noise reduction process to ensure picture quality for public viewing. The proposed algorithm identifies the candidate noise blocks at the bitstream-level to directly provide a noise reduction process while decoding the bitstream. Throughout the experimental results, we confirm the efficiency of the proposed method by showing RR and PR values of around 70 percent.

  • Tailored Optical Frequency Comb Block Generation Using InP-Based Mach-Zehnder Modulator

    Takahiro YAMAMOTO  Takeaki SAIKAI  Eiichi YAMADA  Hiroshi YASAKA  

     
    BRIEF PAPER-Lasers, Quantum Electronics

      Vol:
    E97-C No:3
      Page(s):
    222-224

    A reduction in the intensity deviation of a nine-channel optical frequency comb block (OFCB) is demonstrated, by adopting an asymmetric differential drive method for an InP-based dual drive Mach-Zehnder modulator. The generation of a tailored OFCB with an intensity deviation of less than 0.8dB is confirmed by using the modulator.

  • Integrating Facial Expression and Body Gesture in Videos for Emotion Recognition

    Jingjie YAN  Wenming ZHENG  Minhai XIN  Jingwei YAN  

     
    LETTER-Pattern Recognition

      Vol:
    E97-D No:3
      Page(s):
    610-613

    In this letter, we research the method of using face and gesture image sequences to deal with the video-based bimodal emotion recognition problem, in which both Harris plus cuboids spatio-temporal feature (HST) and sparse canonical correlation analysis (SCCA) fusion method are applied to this end. To efficaciously pick up the spatio-temporal features, we adopt the Harris 3D feature detector proposed by Laptev and Lindeberg to find the points from both face and gesture videos, and then apply the cuboids feature descriptor to extract the facial expression and gesture emotion features [1],[2]. To further extract the common emotion features from both facial expression feature set and gesture feature set, the SCCA method is applied and the extracted emotion features are used for the biomodal emotion classification, where the K-nearest neighbor classifier and the SVM classifier are respectively used for this purpose. We test this method on the biomodal face and body gesture (FABO) database and the experimental results demonstrate the better recognition accuracy compared with other methods.

  • Guard Zone Protected Capacity in Multi-Cell MISO Networks under Fading and Shadowing

    Qi XI  Chen HE  Lingge JIANG  

     
    LETTER-Communication Theory and Signals

      Vol:
    E97-A No:3
      Page(s):
    899-903

    The exact power distribution of the inter-cell interference is obtained explicitly for cell edge users who are surrounded by circular guard zones. Compared with recent works, the underlying channel model is generalized from Rayleigh fading to a combination of Nakagami fading and Gamma shadowing. In addtion, asymptotic analysis shows that the mean power of intercell interference changes from infinite to finite with a guard zone. Based on this interference distribution, the average capacity at the cell edge is further obtained. Special case approximation indicates that the capacity scales proportionally to the exponential of the guard zone size. Analytical capacities are validated by Monte Carlo simulations.

  • On the Complexity of Computing Discrete Logarithms over Algebraic Tori

    Shuji ISOBE  Eisuke KOIZUMI  Yuji NISHIGAKI  Hiroki SHIZUYA  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E97-D No:3
      Page(s):
    442-447

    This paper studies the complexity of computing discrete logarithms over algebraic tori. We show that the order certified version of the discrete logarithm problem over general finite fields (OCDL, in symbols) reduces to the discrete logarithm problem over algebraic tori (TDL, in symbols) with respect to the polynomial-time Turing reducibility. This reduction means that if the prime factorization can be computed in polynomial time, then TDL is equivalent to the discrete logarithm problem over general finite fields with respect to the Turing reducibility.

  • A New Artificial Fish Swarm Algorithm for the Multiple Knapsack Problem

    Qing LIU  Tomohiro ODAKA  Jousuke KUROIWA  Haruhiko SHIRAI  Hisakazu OGURA  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E97-D No:3
      Page(s):
    455-468

    A new artificial fish swarm algorithm (AFSA) for solving the multiple knapsack problem (MKP) is introduced in this paper. In the proposed AFSA, artificial fish (AF) individuals are only allowed to search the region near constraint boundaries of the problem to be solved. For this purpose, several behaviors to be performed by AF individuals, including escaping behavior, randomly moving behavior, preying behavior and following behavior, were specially designed. Exhaustive experiments were implemented in order to investigate the proposed AFSA's performance. The results demonstrated the proposed AFSA has the ability of finding high-quality solutions with very fast speed, as compared with some other versions of AFSA based on different constraint-handling methods. This study is also meaningful for solving other constrained problems.

  • FOREWORD Open Access

    Yukitoshi SANADA  

     
    FOREWORD

      Vol:
    E97-B No:2
      Page(s):
    241-241
  • FOREWORD

    Susumu HASHIZUME  

     
    FOREWORD

      Vol:
    E97-A No:2
      Page(s):
    451-451
  • Stabilization Technique for Region-of-Interest Trajectories Made from Video Watching Manipulations

    Daisuke OCHI  Hideaki KIMATA  Yoshinori KUSACHI  Kosuke TAKAHASHI  Akira KOJIMA  

     
    PAPER-Human-computer Interaction

      Vol:
    E97-D No:2
      Page(s):
    266-274

    Due to the recent progress made in camera and network environments, on-line video services enable people around the world to watch or share high-quality HD videos that can record a wider angle without losing objects' details in each image. As a result, users of these services can watch videos in different ways with different ROIs (Regions of Interest), especially when there are multiple objects in a scene, and thus there are few common ways for them to transfer their impressions for each scene directly. Posting messages is currently the usual way but it does not sufficiently enable all users to transfer their impressions. To transfer a user's impressions directly and provide users with a richer video watching experience, we propose a system that enables them to extract their favorite parts of videos as ROI trajectories through simple and intuitive manipulation of their tablet device. It also enables them to share a recorded trajectory with others after stabilizing it in a manner that should be satisfactory to every user. Using statistical analysis of user manipulations, we have demonstrated an approach to trajectory stabilization that can eliminate undesirable or uncomfortable elements due to tablet-specific manipulations. The system's validity has been confirmed by subjective evaluations.

  • FOREWORD

    Kenji SUGIYAMA  

     
    FOREWORD

      Vol:
    E97-A No:2
      Page(s):
    490-490
  • A Survey on OpenFlow Technologies Open Access

    Kazuya SUZUKI  Kentaro SONODA  Nobuyuki TOMIZAWA  Yutaka YAKUWA  Terutaka UCHIDA  Yuta HIGUCHI  Toshio TONOUCHI  Hideyuki SHIMONISHI  

     
    INVITED SURVEY PAPER

      Vol:
    E97-B No:2
      Page(s):
    375-386

    The paper presents a survey on OpenFlow related technologies that have been proposed as a means for researchers, network service creators, and others to easily design, test, and deploy their innovative ideas in experimental or production networks to accelerate research activities on network technologies. Rather than having programmability within each network node, separated OpenFlow controllers provide network control through pluggable software modules; thus, it is easy to develop new network control functions in executable form and test them in production networks. The emergence of OpenFlow has started various research activities. The paper surveys these activities and their results.

  • Adaptive Marker Coding for Insertion/Deletion/Substitution Error Correction

    Masato INOUE  Haruhiko KANEKO  

     
    PAPER-Coding Theory

      Vol:
    E97-A No:2
      Page(s):
    642-651

    This paper proposes an adaptive marker coding (AMC) for correction of insertion/deletion/substitution errors. Unlike the conventional marker codings which select marker-bit values deterministically, the AMC adaptively reverses the first and last bits of each marker as well as bits surrounding the marker. Decoding is based on a forward-backward algorithm which takes into account the dependency of bit-values around the marker. Evaluation shows that, for a channel with insertion/deletion error probability 1.8×10-2, the decoded BER of existing marker coding of rate 9/16 is 4.25×10-3, while that of the proposed coding with the same code rate is 1.73×10-3.

10261-10280hit(42807hit)