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[Keyword] CTI(8214hit)

581-600hit(8214hit)

  • Collaborative Ontology Development and its Use for Video Annotation in Elderly Care Domain

    Satoshi NISHIMURA  Julio VIZCARRA  Yuichi OOTA  Ken FUKUDA  

     
    PAPER

      Pubricized:
    2021/02/04
      Vol:
    E104-D No:5
      Page(s):
    528-538

    Multimedia data and information management is an important task according to the development of media processing technology. Multimedia is a useful resource that people understand complex situations such as the elderly care domain. Appropriate annotation is beneficial in several tasks of information management, such as storing, retrieval, and summarization of data, from a semantic perspective. However, the metadata annotation for multimedia data remains problematic because metadata is obtained as a result of interpretation depending on domain-specific knowledge, and it needs well-controlled and comprehensive vocabulary for annotation. In this study, we proposed a collaborative methodology for developing ontologies and annotation with domain experts. The method includes (1) classification of knowledge types for collaborative construction of annotation data, (2) division of tasks among a team composed of domain experts, ontology engineers, and annotators, and (3) incremental approach to ontology development. We applied the proposed method to 11 videos on elderly care domain for the confirmation of its feasibility. We focused on annotation of actions occurring in these videos, thereby the annotated data is used as a support in evaluating staff skills. The application results show the content in the ontology during annotation increases monotonically. The number of “action concepts” is saturated and reused among the case studies. This demonstrates that the ontology is reusable and could represent various case studies by using a small number of “action concepts”. This study concludes by presenting lessons learnt from the case studies.

  • An Evaluation of the Effectiveness of ECN with Fallback on the Internet

    Linzhi ZOU  Kenichi NAGAOKA  Chun-Xiang CHEN  

     
    PAPER

      Pubricized:
    2021/02/24
      Vol:
    E104-D No:5
      Page(s):
    628-636

    In this paper, we used the data set of domain names Global Top 1M provided by Alexa to analyze the effectiveness of Fallback in ECN. For the same test server, we first negotiate a connection with Not-ECN-Capable, and then negotiate a connection with ECN-Capable, if the sender does not receive the response to ECN-Capable negotiation from the receiver by the end of retransmission timeout, it will enter the Fallback state, and switch to negotiating a connection with Not-ECN-Capable. By extracting the header fields of the TCP/IP packets, we confirmed that in most regions, connectivity will be slightly improved after Fallback is enabled and Fallback has a positive effect on the total time of the whole access process. Meanwhile, we provided the updated information about the characteristics related to ECN with Fallback in different regions by considering the geographical region distribution of all targeted servers.

  • Noise-Robust Distorted Born Iterative Method with Prior Estimate for Microwave Ablation Monitoring Open Access

    Yuriko TAKAISHI  Shouhei KIDERA  

     
    BRIEF PAPER-Electromagnetic Theory

      Pubricized:
    2020/10/06
      Vol:
    E104-C No:4
      Page(s):
    148-152

    A noise-robust and accuracy-enhanced microwave imaging algorithm is presented for microwave ablation monitoring of cancer treatment. The ablation impact of dielectric change can be assessed by microwave inverse scattering analysis, where the dimension and dielectric drop of the ablation zone enable safe ablation monitoring. We focus on the distorted Born iterative method (DBIM), which is applicable to highly heterogeneous and contrasted dielectric profiles. As the reconstruction accuracy and convergence speed of DBIM depend largely on the initial estimate of the dielectric profile or noise level, this study exploits a prior estimate of the DBIM for the pre-ablation state to accelerate the convergence speed and introduces the matched-filter-based noise reduction scheme in the DBIM framework. The two-dimensional finite-difference time-domain numerical test with realistic breast phantoms shows that our method significantly enhances the reconstruction accuracy with a lower computational cost.

  • Statistical Analysis of Phase-Only Correlation Functions under the Phase Fluctuation of Signals due to Additive Gaussian Noise

    Shunsuke YAMAKI  Kazuhiro FUKUI  Masahide ABE  Masayuki KAWAMATA  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2020/09/29
      Vol:
    E104-A No:4
      Page(s):
    671-679

    This paper proposes statistical analysis of phase-only correlation (POC) functions under the phase fluctuation of signals due to additive Gaussian noise. We derive probability density function of phase-spectrum differences between original signal and its noise-corrupted signal with additive Gaussian noise. Furthermore, we evaluate the expectation and variance of the POC functions between these two signals. As the variance of Gaussian noise increases, the expectation of the peak of the POC function monotonically decreases and variance of the POC function monotonically increases. These results mathematically guarantee the validity of the POC functions used for similarity measure in matching techniques.

  • Approximate Simultaneous Diagonalization of Matrices via Structured Low-Rank Approximation

    Riku AKEMA  Masao YAMAGISHI  Isao YAMADA  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2020/10/15
      Vol:
    E104-A No:4
      Page(s):
    680-690

    Approximate Simultaneous Diagonalization (ASD) is a problem to find a common similarity transformation which approximately diagonalizes a given square-matrix tuple. Many data science problems have been reduced into ASD through ingenious modelling. For ASD, the so-called Jacobi-like methods have been extensively used. However, the methods have no guarantee to suppress the magnitude of off-diagonal entries of the transformed tuple even if the given tuple has an exact common diagonalizer, i.e., the given tuple is simultaneously diagonalizable. In this paper, to establish an alternative powerful strategy for ASD, we present a novel two-step strategy, called Approximate-Then-Diagonalize-Simultaneously (ATDS) algorithm. The ATDS algorithm decomposes ASD into (Step 1) finding a simultaneously diagonalizable tuple near the given one; and (Step 2) finding a common similarity transformation which diagonalizes exactly the tuple obtained in Step 1. The proposed approach to Step 1 is realized by solving a Structured Low-Rank Approximation (SLRA) with Cadzow's algorithm. In Step 2, by exploiting the idea in the constructive proof regarding the conditions for the exact simultaneous diagonalizability, we obtain an exact common diagonalizer of the obtained tuple in Step 1 as a solution for the original ASD. Unlike the Jacobi-like methods, the ATDS algorithm has a guarantee to find an exact common diagonalizer if the given tuple happens to be simultaneously diagonalizable. Numerical experiments show that the ATDS algorithm achieves better performance than the Jacobi-like methods.

  • Transmission Control Method for Data Retention Taking into Account the Low Vehicle Density Environments

    Ichiro GOTO  Daiki NOBAYASHI  Kazuya TSUKAMOTO  Takeshi IKENAGA  Myung LEE  

     
    LETTER-Information Network

      Pubricized:
    2021/01/05
      Vol:
    E104-D No:4
      Page(s):
    508-512

    With the development and spread of Internet of Things (IoT) technology, various kinds of data are now being generated from IoT devices. Some data generated from IoT devices depend on geographical location and time, and we refer to them as spatio-temporal data (STD). Since the “locally produced and consumed” paradigm of STD use is effective for location-dependent applications, the authors have previously proposed a vehicle-based STD retention system. However, in low vehicle density environments, the data retention becomes difficult due to the decrease in the number of data transmissions in this method. In this paper, we propose a new data transmission control method for data retention in the low vehicle density environments.

  • Forcible Search Scheme for Mixed Gibbs Sampling Massive MIMO Detection

    Kenji YAMAZAKI  Yukitoshi SANADA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2020/10/06
      Vol:
    E104-B No:4
      Page(s):
    419-427

    In this paper, mixed Gibbs sampling multiple-input multiple-output (MIMO) detection with forcible search is proposed. In conventional Gibbs sampling MIMO detection, the problem of stalling occurs under high signal-to-noise ratios (SNRs) which degrades the detection performance. Mixed Gibbs sampling (MGS) is one solution to this problem. In MGS, random sampling is carried out with a constant probability regardless of whether a current search falls into a local minimum. In the proposed scheme, combined with MGS, multiple candidate symbols are forcibly changed when the search is captured by a local minimum. The search restarts away from the local minimum which effectively enlarges the search area in the solution space. Numerical results obtained through computer simulation show that the proposed scheme achieves better performance in a large scale MIMO system with QPSK signals.

  • Development and Effectiveness Evaluation of Interactive Voice HMI System

    Chiharu KATAOKA  Osamu KUKIMOTO  Yuichiro YOSHIKAWA  Kohei OGAWA  Hiroshi ISHIGURO  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2021/01/13
      Vol:
    E104-D No:4
      Page(s):
    500-507

    Connected services have been under development in the automotive industry. Meanwhile, the volume of predictive notifications that utilize travel-related data is increasing, and there are concerns that drivers cannot process such an amount of information or do not accept and follow such predictive instructions straightforwardly because the information provided is predicted. In this work, an interactive voice system using two agents is proposed to realize notifications that can easily be accepted by drivers and enhance the reliability of the system by adding contextual information. An experiment was performed using a driving simulator to compare the following three forms of notifications: (1) notification with no contextual information, (2) notification with contextual information using one agent, and (3) notification with contextual information using two agents. The notification content was limited to probable near-miss incidents. The results of the experiment indicate that the driver may decelerate more with the one- and two-agent notification methods than with the conventional notification method. The degree of deceleration depended the number of times the notification was provided and whether there were cars parked on the streets.

  • Optimization and Hole Interpolation of 2-D Sparse Arrays for Accurate Direction-of-Arrival Estimation

    Shogo NAKAMURA  Sho IWAZAKI  Koichi ICHIGE  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2020/10/21
      Vol:
    E104-B No:4
      Page(s):
    401-409

    This paper presents a method to optimize 2-D sparse array configurations along with a technique to interpolate holes to accurately estimate the direction of arrival (DOA). Conventional 2-D sparse arrays are often defined using a closed-form representation and have the property that they can create hole-free difference co-arrays that can estimate DOAs of incident signals that outnumber the physical elements. However, this property restricts the array configuration to a limited structure and results in a significant mutual coupling effect between consecutive sensors. In this paper, we introduce an optimization-based method for designing 2-D sparse arrays that enhances flexibility of array configuration as well as DOA estimation accuracy. We also propose a method to interpolate holes in 2-D co-arrays by nuclear norm minimization (NNM) that permits holes and to extend array aperture to further enhance DOA estimation accuracy. The performance of the proposed optimum arrays is evaluated through numerical examples.

  • Backbone Alignment and Cascade Tiny Object Detecting Techniques for Dolphin Detection and Classification

    Yih-Cherng LEE  Hung-Wei HSU  Jian-Jiun DING  Wen HOU  Lien-Shiang CHOU  Ronald Y. CHANG  

     
    PAPER-Image

      Pubricized:
    2020/09/29
      Vol:
    E104-A No:4
      Page(s):
    734-743

    Automatic tracking and classification are essential for studying the behaviors of wild animals. Owing to dynamic far-shooting photos, the occlusion problem, protective coloration, the background noise is irregular interference for designing a computerized algorithm for reducing human labeling resources. Moreover, wild dolphin images are hard-acquired by on-the-spot investigations, which takes a lot of waiting time and hardly sets the fixed camera to automatic monitoring dolphins on the ocean in several days. It is challenging tasks to detect well and classify a dolphin from polluted photos by a single famous deep learning method in a small dataset. Therefore, in this study, we propose a generic Cascade Small Object Detection (CSOD) algorithm for dolphin detection to handle small object problems and develop visualization to backbone based classification (V2BC) for removing noise, highlighting features of dolphin and classifying the name of dolphin. The architecture of CSOD consists of the P-net and the F-net. The P-net uses the crude Yolov3 detector to be a core network to predict all the regions of interest (ROIs) at lower resolution images. Then, the F-net, which is more robust, is applied to capture the ROIs from high-resolution photos to solve single detector problems. Moreover, a visualization to backbone based classification (V2BC) method focuses on extracting significant regions of occluded dolphin and design significant post-processing by referencing the backbone of dolphins to facilitate for classification. Compared to the state of the art methods, including faster-rcnn, yolov3 detection and Alexnet, the Vgg, and the Resnet classification. All experiments show that the proposed algorithm based on CSOD and V2BC has an excellent performance in dolphin detection and classification. Consequently, compared to the related works of classification, the accuracy of the proposed designation is over 14% higher. Moreover, our proposed CSOD detection system has 42% higher performance than that of the original Yolov3 architecture.

  • User Scheduling with Beam Selection for Full Digital Massive MIMO Base Station

    Masahito YATA  Go OTSURU  Yukitoshi SANADA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2020/10/15
      Vol:
    E104-B No:4
      Page(s):
    428-435

    In this paper, user scheduling with beam selection for full-digital massive multi-input multi-output (MIMO) is proposed. Inter-user interference (IUI) can be canceled by precoding such as zero-forcing at a massive MIMO base station if ideal hardware implementation is assumed. However, owing to the non-ideal characteristics of hardware components, IUI occurs among multiple user terminals allocated on the same resource. Thus, in the proposed scheme, the directions of beams for allocated user terminals are adjusted to maximize the total user throughput. User allocation based on the user throughput after the adjustment of beam directivity is then carried out. Numerical results obtained through computer simulation show that when the number of user terminals in the cell is two and the number of user terminals allocated to one resource block (RB) is two, the throughput per subcarrier per subframe improves by about 3.0 bits. On the other hand, the fairness index (FI) is reduced by 0.03. This is because only the probability in the high throughput region increases as shown in the cumulative distribution function (CDF) of throughput per user. Also, as the number of user terminals in the cell increases, the amount of improvement in throughput decreases. As the number of allocated user terminals increases, more user terminals are allocated to the cell-edge, which reduces the average throughput.

  • Malicious URLs Detection Based on a Novel Optimization Algorithm

    Wang BO  Zhang B. FANG  Liu X. WEI  Zou F. CHENG  Zhang X. HUA  

     
    LETTER-Information Network

      Pubricized:
    2021/01/14
      Vol:
    E104-D No:4
      Page(s):
    513-516

    In this paper, the issue of malicious URL detection is investigated. Firstly a P system is proposed. Then the new P system is introduced to design the optimization algorithm of BP neural network to achieve the malicious URL detection with better performance. In the end some examples are included and corresponding experimental results display the advantage and effectiveness of the optimization algorithm proposed.

  • Building a Measurement Model for Simulating Naturalness of Vibrato Based on Subjective Evaluation

    Takahiro MIYAZAKI  Masanori MORISE  

     
    LETTER-Speech and Hearing

      Pubricized:
    2021/01/05
      Vol:
    E104-D No:4
      Page(s):
    521-525

    This work introduces a measurement model to estimate the naturalness of vibrato. We carried out a subjective evaluation using a mean opinion score (MOS). We then built a measurement model by using two-dimensional Gaussian functions. We found that three Gaussian functions can measure naturalness with an error of 4.0%.

  • Multiclass Dictionary-Based Statistical Iterative Reconstruction for Low-Dose CT

    Hiryu KAMOSHITA  Daichi KITAHARA  Ken'ichi FUJIMOTO  Laurent CONDAT  Akira HIRABAYASHI  

     
    PAPER-Numerical Analysis and Optimization

      Pubricized:
    2020/10/06
      Vol:
    E104-A No:4
      Page(s):
    702-713

    This paper proposes a high-quality computed tomography (CT) image reconstruction method from low-dose X-ray projection data. A state-of-the-art method, proposed by Xu et al., exploits dictionary learning for image patches. This method generates an overcomplete dictionary from patches of standard-dose CT images and reconstructs low-dose CT images by minimizing the sum of a data fidelity and a regularization term based on sparse representations with the dictionary. However, this method does not take characteristics of each patch, such as textures or edges, into account. In this paper, we propose to classify all patches into several classes and utilize an individual dictionary with an individual regularization parameter for each class. Furthermore, for fast computation, we introduce the orthogonality to column vectors of each dictionary. Since similar patches are collected in the same cluster, accuracy degradation by the orthogonality hardly occurs. Our simulations show that the proposed method outperforms the state-of-the-art in terms of both accuracy and speed.

  • Noise Robust Acoustic Anomaly Detection System with Nonnegative Matrix Factorization Based on Generalized Gaussian Distribution

    Akihito AIBA  Minoru YOSHIDA  Daichi KITAMURA  Shinnosuke TAKAMICHI  Hiroshi SARUWATARI  

     
    PAPER-Speech and Hearing

      Pubricized:
    2020/12/18
      Vol:
    E104-D No:3
      Page(s):
    441-449

    We studied an acoustic anomaly detection system for equipments, where the outlier detection method based on recorded sounds is used. In a real environment, the SNR of the target sound against background noise is low, and there is the problem that it is necessary to catch slight changes in sound buried in noise. In this paper, we propose a system in which a sound source extraction process is provided at the preliminary stage of the outlier detection process. In the proposed system, nonnegative matrix factorization based on generalized Gaussian distribution (GGD-NMF) is used as a sound source extraction process. We evaluated the improvement of the anomaly detection performance in a low-SNR environment. In this experiment, SNR capable of detecting an anomaly was greatly improved by providing GGD-NMF for preprocessing.

  • A Note on Enumeration of 3-Edge-Connected Spanning Subgraphs in Plane Graphs

    Yasuko MATSUI  Kenta OZEKI  

     
    LETTER

      Pubricized:
    2020/10/07
      Vol:
    E104-D No:3
      Page(s):
    389-391

    This paper deals with the problem of enumerating 3-edge-connected spanning subgraphs of an input plane graph. In 2018, Yamanaka et al. proposed two enumeration algorithms for such a problem. Their algorithm generates each 2-edge-connected spanning subgraph of a given plane graph with n vertices in O(n) time, and another one generates each k-edge-connected spanning subgraph of a general graph with m edges in O(mT) time, where T is the running time to check the k-edge connectivity of a graph. This paper focuses on the case of the 3-edge-connectivity in a plane graph. We give an algorithm which generates each 3-edge-connected spanning subgraph of the input plane graph in O(n2) time. This time complexity is the same as the algorithm by Yamanaka et al., but our algorithm is simpler than theirs.

  • Research on Contact Performance of Aviation Electrical Connector under Atmospheric Turbulence

    Yanyan LUO  Guoping WANG  Ming CAI  Le ZHANG  Zhaopan ZHANG  

     
    PAPER-Electromechanical Devices and Components

      Pubricized:
    2020/09/07
      Vol:
    E104-C No:3
      Page(s):
    112-120

    Electrical connectors are the basic components of the electric system in automobiles, aircrafts and ships to realize the current and electrical signal transmission. In the aviation electrical system, the electrical connectors are indispensable supporting devices accessories, which play important roles in connecting electrical system, monitoring and controlling equipment, and provide a guarantee for the reliable transmission of electrical signals between the aviation equipment and system. Whether aviation electrical connectors work reliably directly affects the safety and reliability of the entire aircraft aviation system. The random vibration of aircraft caused by turbulence during flight is one of the main factors affecting the contact performance of the electrical connectors. In this paper, the contacts of the circular four-slot three-pin electrical connectors were chosen as the research specimens. The theoretical model of the contact force for contacts of electrical connectors was established. The test method for contact force measurement was determined. According to the test scheme, the detecting device for the contact force and contact resistance of the electrical connectors was designed, and the turbulence test of the electrical connectors was carried out. Through the analysis of the test data, the influence rule of the turbulence degree, flight speed and flight height on the contact force and contact resistance of the aviation electrical connectors was obtained.

  • Self-Learning pLSA Model for Abnormal Behavior Detection in Crowded Scenes

    Shuoyan LIU  Enze YANG  Kai FANG  

     
    LETTER-Pattern Recognition

      Pubricized:
    2020/11/30
      Vol:
    E104-D No:3
      Page(s):
    473-476

    Abnormal behavior detection is now a widely concerned research field, especially for crowded scenes. However, most traditional unsupervised approaches often suffered from the problem when the normal events in the scenario with large visual variety. This paper proposes a self-learning probabilistic Latent Semantic Analysis, which aims at taking full advantage of the high-level abnormal information to solve problems. We select the informative observations to construct the “reference events” from the training sets as a high-level guidance cue. Specifically, the training set is randomly divided into two separate subsets. One is used to learn this model, which is defined as the initialization sequence of “reference events”. The other aims to update this model and the the infrequent samples are chosen into the “reference events”. Finally, we define anomalies using events that are least similar to “reference events”. The experimental result demonstrates that the proposed model can detect anomalies accurately and robustly in the real-world crowd environment.

  • Low Complexity Overloaded MIMO Detection Based on Belief Propagation with MMSE Pre-Cancellation

    Takashi IMAMURA  Yukitoshi SANADA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2020/09/09
      Vol:
    E104-B No:3
      Page(s):
    312-319

    In this paper, the application of minimum mean square error (MMSE) pre-cancellation prior to belief propagation (BP) is proposed as a detection scheme for overloaded multiple-input multiple-output (MIMO) systems. In overloaded MIMO systems, the loops in the factor graph degrade the demodulation performance of BP. Therefore, the proposed scheme applies MMSE pre-cancellation prior to BP and reduces the number of loops. Furthermore, it is applied to the selected transmit and receive nodes so that the condition number of an inverse matrix in the MMSE weight matrix is minimized to suppress the residual interference and the noise after MMSE pre-cancellation. Numerical results obtained through computer simulation show that the proposed scheme achieves better bit error rate (BER) performance than BP without MMSE pre-cancellation. The proposed scheme improves the BER performance by 2.9-5.6dB at a BER of 5.0×10-3 compared with conventional BP. Numerical results also show that MMSE pre-cancellation reduces the complexity of BP by a factor of 896 in terms of the number of multiplication operations.

  • End-to-End SDN/NFV Orchestration of Multi-Domain Transport Networks and Distributed Computing Infrastructure for Beyond-5G Services Open Access

    Carlos MANSO  Pol ALEMANY  Ricard VILALTA  Raul MUÑOZ  Ramon CASELLAS  Ricardo MARTÍNEZ  

     
    INVITED PAPER-Network

      Pubricized:
    2020/09/11
      Vol:
    E104-B No:3
      Page(s):
    188-198

    The need of telecommunications operators to reduce Capital and Operational Expenditures in networks which traffic is continuously growing has made them search for new alternatives to simplify and automate their procedures. Because of the different transport network segments and multiple layers, the deployment of end-to-end services is a complex task. Also, because of the multiple vendor existence, the control plane has not been fully homogenized, making end-to-end connectivity services a manual and slow process, and the allocation of computing resources across the entire network a difficult task. The new massive capacity requested by Data Centers and the new 5G connectivity services will urge for a better solution to orchestrate the transport network and the distributed computing resources. This article presents and demonstrates a Network Slicing solution together with an end-to-end service orchestration for transport networks. The Network Slicing solution permits the co-existence of virtual networks (one per service) over the same physical network to ensure the specific service requirements. The network orchestrator allows automated end-to-end services across multi-layer multi-domain network segments making use of the standard Transport API (TAPI) data model for both l0 and l2 layers. Both solutions will allow to keep up with beyond 5G services and the higher and faster demand of network and computing resources.

581-600hit(8214hit)