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1621-1640hit(42807hit)

  • Resilient Virtual Network Embedding Ensuring Connectivity under Substrate Node Failures

    Nagao OGINO  

     
    PAPER-Network

      Pubricized:
    2021/11/11
      Vol:
    E105-B No:5
      Page(s):
    557-568

    A variety of smart services are being provided on multiple virtual networks embedded into a common inter-cloud substrate network. The substrate network operator deploys critical substrate nodes so that multiple service providers can achieve enhanced services due to the secure sharing of their service data. Even if one of the critical substrate nodes incurs damage, resiliency of the enhanced services can be assured due to reallocation of the workload and periodic backup of the service data to the other normal critical substrate nodes. However, the connectivity of the embedded virtual networks must be maintained so that the enhanced services can be continuously provided to all clients on the virtual networks. This paper considers resilient virtual network embedding (VNE) that ensures the connectivity of the embedded virtual networks after critical substrate node failures have occurred. The resilient VNE problem is formulated using an integer linear programming model and a distance-based method is proposed to solve the large-scale resilient VNE problem efficiently. Simulation results demonstrate that the distance-based method can derive a sub-optimum VNE solution with a small computational effort. The method derived a VNE solution with an approximation ratio of less than 1.2 within ten seconds in all the simulation experiments.

  • Analysis and Design of a Linear Ka-Band Power Amplifier in 65-nm CMOS for 5G Applications

    Chongyu YU  Jun FENG  

     
    PAPER-Microwaves, Millimeter-Waves

      Pubricized:
    2021/12/14
      Vol:
    E105-C No:5
      Page(s):
    184-193

    A linear and broadband power amplifier (PA) for 5G phased-array is presented. The design improves the linearity by operating the transistors in deep class AB region. The design broadens the bandwidth by applying the inter-stage weakly-coupled transformer. The theory of transformers is illustrated by analyzing the odd- and even-mode model. Based on this, the odd-mode Q factor is used to evaluate the quality of impedance matching. Weakly- and strongly-coupled transformers are compared and analyzed in both the design process and applicable characteristics. Besides, a well-founded method to achieve the transformer-based balanced-unbalanced transformation is proposed. The fully integrated two-stage PA is designed and implemented in a 65-nm CMOS process with a 1-V power supply to provide a maximum small-signal gain of 19dB. The maximum output 1-dB compressed power (P1dB) of 17.4dBm and the saturated output power (PSAT) of 18dBm are measured at 28GHz. The power-added efficiency (PAE) of the P1dB is 26.5%. From 23 to 32GHz, the measured P1dB is above 16dBm, covering the potential 5G bands worldwide around 28GHz.

  • Signal Quality Improvement in Downlink Power Domain NOMA with Blind Nonlinear Compensator and Frequency Domain Equalizer Open Access

    Jun NAGAI  Koji ISHIBASHI  Yasushi YAMAO  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2021/12/01
      Vol:
    E105-B No:5
      Page(s):
    648-656

    The non-orthogonal multiple access (NOMA) approach has been developed in the fifth-generation mobile communication systems (5G) and beyond, to improve the spectrum efficiency and accommodate a large number of IoT devices. Although power domain NOMA is a promising candidate, it is vulnerable to the nonlinearity of RF circuits and cannot achieve high-throughput transmission using high-level modulations in nonlinear environments. This study proposes a novel post-reception nonlinear compensation scheme consisting of two blind nonlinear compensators (BNLCs) and a frequency-domain equalizer (FDE) to reduce the effect of nonlinear distortion. The improvement possible with the proposed scheme is evaluated by using the error vector magnitude (EVM) of the received signal, which is obtained through computer simulations. The simulation results confirm that the proposed scheme can effectively improve the quality of the received downlink power-domain NOMA signal and enable high-throughput transmission under the transmitter (Tx) and receiver (Rx) nonlinearities via a frequency-selective fading channel.

  • Localization of Pointed-At Word in Printed Documents via a Single Neural Network

    Rubin ZHAO  Xiaolong ZHENG  Zhihua YING  Lingyan FAN  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/01/26
      Vol:
    E105-D No:5
      Page(s):
    1075-1084

    Most existing object detection methods and text detection methods are mainly designed to detect either text or objects. In some scenarios where the task is to find the target word pointed-at by an object, results of existing methods are far from satisfying. However, such scenarios happen often in human-computer interaction, when the computer needs to figure out which word the user is pointing at. Comparing with object detection, pointed-at word localization (PAWL) requires higher accuracy, especially in dense text scenarios. Moreover, in printed document, characters are much smaller than those in scene text detection datasets such as ICDAR-2013, ICDAR-2015 and ICPR-2018 etc. To address these problems, the authors propose a novel target word localization network (TWLN) to detect the pointed-at word in printed documents. In this work, a single deep neural network is trained to extract the features of markers and text sequentially. For each image, the location of the marker is predicted firstly, according to the predicted location, a smaller image is cropped from the original image and put into the same network, then the location of pointed-at word is predicted. To train and test the networks, an efficient approach is proposed to generate the dataset from PDF format documents by inserting markers pointing at the words in the documents, which avoids laborious labeling work. Experiments on the proposed dataset demonstrate that TWLN outperforms the compared object detection method and optical character recognition method on every category of targets, especially when the target is a single character that only occupies several pixels in the image. TWLN is also tested with real photographs, and the accuracy shows no significant differences, which proves the validity of the generating method to construct the dataset.

  • Online EEG-Based Emotion Prediction and Music Generation for Inducing Affective States

    Kana MIYAMOTO  Hiroki TANAKA  Satoshi NAKAMURA  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2022/02/15
      Vol:
    E105-D No:5
      Page(s):
    1050-1063

    Music is often used for emotion induction because it can change the emotions of people. However, since we subjectively feel different emotions when listening to music, we propose an emotion induction system that generates music that is adapted to each individual. Our system automatically generates suitable music for emotion induction based on the emotions predicted from an electroencephalogram (EEG). We examined three elements for constructing our system: 1) a music generator that creates music that induces emotions that resemble the inputs, 2) emotion prediction using EEG in real-time, and 3) the control of a music generator using the predicted emotions for making music that is suitable for inducing emotions. We constructed our proposed system using these elements and evaluated it. The results showed its effectiveness for inducing emotions and suggest that feedback loops that tailor stimuli to individuals can successfully induce emotions.

  • Evaluation and Test of Production Defects in Hardened Latches

    Ruijun MA  Stefan HOLST  Xiaoqing WEN  Aibin YAN  Hui XU  

     
    PAPER-Dependable Computing

      Pubricized:
    2022/02/07
      Vol:
    E105-D No:5
      Page(s):
    996-1009

    As modern CMOS circuits fabricated with advanced technology nodes are becoming more and more susceptible to soft-errors, many hardened latches have been proposed for reliable LSI designs. We reveal for the first time that production defects in such hardened latches can cause two serious problems: (1) these production defects are difficult to detect with conventional scan test and (2) these production defects can reduce the reliability of hardened latches. This paper systematically addresses these two problems with three major contributions: (1) Post-Test Vulnerability Factor (PTVF), a first-of-its-kind metric for quantifying the impact of production defects on hardened latches, (2) a novel Scan-Test-Aware Hardened Latch (STAHL) design that has the highest defect coverage compared to state-of-the-art hardened latch designs, and (3) an STAHL-based scan test procedure. Comprehensive simulation results demonstrate the accuracy of the proposed PTVF metric and the effectiveness of the STAHL-based scan test. As the first comprehensive study bridging the gap between hardened latch design and LSI testing, the findings of this paper will significantly improve the soft-error-related reliability of LSI designs for safety-critical applications.

  • Predicting A Growing Stage of Rice Plants Based on The Cropping Records over 25 Years — A Trial of Feature Engineering Incorporating Hidden Regional Characteristics —

    Hiroshi UEHARA  Yasuhiro IUCHI  Yusuke FUKAZAWA  Yoshihiro KANETA  

     
    PAPER

      Pubricized:
    2021/12/29
      Vol:
    E105-D No:5
      Page(s):
    955-963

    This study tries to predict date of ear emergence of rice plants, based on cropping records over 25 years. Predicting ear emergence of rice plants is known to be crucial for practicing good harvesting quality, and has long been dependent upon old farmers who acquire skills of intuitive prediction based on their long term experiences. Facing with aging farmers, data driven approach for the prediction have been pursued. Nevertheless, they are not necessarily sufficient in terms of practical use. One of the issue is to adopt weather forecast as the feature so that the predictive performance is varied by the accuracy of the forecast. The other issue is that the performance is varied by region and the regional characteristics have not been used as the features for the prediction. With this background, we propose a feature engineering to quantify hidden regional characteristics as the feature for the prediction. Further the feature is engineered based only on observational data without any forecast. Applying our proposal to the data on the cropping records resulted in sufficient predictive performance, ±2.69days of RMSE.

  • Implementation of a Multi-Word Compare-and-Swap Operation without Garbage Collection

    Kento SUGIURA  Yoshiharu ISHIKAWA  

     
    PAPER

      Pubricized:
    2022/02/03
      Vol:
    E105-D No:5
      Page(s):
    946-954

    With the rapid increase in the number of CPU cores, software that can utilize these many cores is required. A lock-free algorithm based on compare-and-swap (CAS) operations is one of the concurrency control methods to implement such multi-threading software. A multi-word CAS (MwCAS) operation is an extension of a CAS operation to swap multiple words atomically. However, we noticed that the performance of the existing MwCAS implementation is limited because of garbage collection even if in a low-contention environment. To achieve high performance in low-contention workloads, we propose a new MwCAS algorithm without garbage collection. Experimental results show that our approach is three to five times faster than implementation with garbage collection in low-contention workloads. Moreover, the performance of the proposed method is also superior in a high-contention environment.

  • Toward Generating Robot-Robot Natural Counseling Dialogue

    Tomoya HASHIGUCHI  Takehiro YAMAMOTO  Sumio FUJITA  Hiroaki OHSHIMA  

     
    PAPER

      Pubricized:
    2022/02/07
      Vol:
    E105-D No:5
      Page(s):
    928-935

    In this study, we generate dialogue contents in which two systems discuss their distress with each other. The user inputs sentences that include environment and feelings of distress. The system generates the dialogue content from the input. In this study, we created dialogue data about distress in order to generate them using deep learning. The generative model fine-tunes the GPT of the pre-trained model using the TransferTransfo method. The contribution of this study is the creation of a conversational dataset using publicly available data. This study used EmpatheticDialogues, an existing empathetic dialogue dataset, and Reddit r/offmychest, a public data set of distress. The models fine-tuned with each data were evaluated both automatically (such as by the BLEU and ROUGE scores) and manually (such as by relevance and empathy) by human assessors.

  • A Low-Cost High-Performance Semantic and Physical Distance Calculation Method Based on ZIP Code

    Da LI  Yuanyuan WANG  Rikuya YAMAMOTO  Yukiko KAWAI  Kazutoshi SUMIYA  

     
    PAPER

      Pubricized:
    2022/01/13
      Vol:
    E105-D No:5
      Page(s):
    920-927

    Recently, machine learning approaches and user movement history analysis on mobile devices have attracted much attention. Generally, we need to apply text data into the word embedding tool for acquiring word vectors as the preprocessing of machine learning approaches. However, it is difficult for mobile devices to afford the huge cost of high-dimensional vector calculation. Thus, a low-cost user behavior and user movement history analysis approach should be considered. To address this issue, firstly, we convert the zip code and street house number into vectors instead of textual address information to reduce the cost of spatial vector calculation. Secondly, we propose a low-cost high-performance semantic and physical distance (real distance) calculation method that applied zip-code-based vectors. Finally, to verify the validity of our proposed method, we utilize the US zip code data to calculate both semantic and physical distances and compare their results with the previous method. The experimental results showed that our proposed method could significantly improve the performance of distance calculation and effectively control the cost to a low level.

  • Does Student-Submission Allocation Affect Peer Assessment Accuracy?

    Hideaki OHASHI  Toshiyuki SHIMIZU  Masatoshi YOSHIKAWA  

     
    PAPER

      Pubricized:
    2022/01/05
      Vol:
    E105-D No:5
      Page(s):
    888-897

    Peer assessment in education has pedagogical benefits and is a promising method for grading a large number of submissions. At the same time, student reliability has been regarded as a problem; consequently, various methods of estimating highly reliable grades from scores given by multiple students have been proposed. Under most of the existing methods, a nonadaptive allocation pattern, which performs allocation in advance, is assumed. In this study, we analyze the effect of student-submission allocation on score estimation in peer assessment under a nonadaptive allocation setting. We examine three types of nonadaptive allocation methods, random allocation, circular allocation and group allocation, which are considered the commonly used approaches among the existing nonadaptive peer assessment methods. Through simulation experiments, we show that circular allocation and group allocation tend to yield lower accuracy than random allocation. Then, we utilize this result to improve the existing adaptive allocation method, which performs allocation and assessment in parallel and tends to make similar allocation result to circular allocation. We propose the method to replace part of the allocation with random allocation, and show that the method is effective through experiments.

  • Performance Analysis on the Uplink of Massive MIMO Systems with Superimposed Pilots and Arbitrary-Bit ADCs

    Chen CHEN  Wence ZHANG  Xu BAO  Jing XIA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2021/10/28
      Vol:
    E105-B No:5
      Page(s):
    629-637

    This paper studies the performance of quantized massive multiple-input multiple-output (MIMO) systems with superimposed pilots (SP), using linear minimum mean-square-error (LMMSE) channel estimation and maximum ratio combining (MRC) detection. In contrast to previous works, arbitrary-bit analog-to-digital converters (ADCs) are considered. We derive an accurate approximation of the uplink achievable rate considering the removal of estimated pilots. Based on the analytical expression, the optimal pilot power factor that maximizes the achievable rate is deduced and an expression for energy efficiency (EE) is given. In addition, the achievable rate and the optimal power allocation policy under some asymptotic limits are analyzed. Analysis shows that the systems with higher-resolution ADCs or larger number of base station (BS) antennas need to allocate more power to pilots. In contrast, more power needs to be allocated to data when the channel is slowly varying. Numerical results show that in the low signal-to-noise ratio (SNR) region, for 1-bit quantizers, SP outperforms time-multiplexed pilots (TP) in most cases, while for systems with higher-resolution ADCs, the SP scheme is suitable for the scenarios with comparatively small number of BS antennas and relatively long channel coherence time.

  • Research on the Algorithm of License Plate Recognition Based on MPGAN Haze Weather

    Weiguo ZHANG  Jiaqi LU  Jing ZHANG  Xuewen LI  Qi ZHAO  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/02/21
      Vol:
    E105-D No:5
      Page(s):
    1085-1093

    The haze situation will seriously affect the quality of license plate recognition and reduce the performance of the visual processing algorithm. In order to improve the quality of haze pictures, a license plate recognition algorithm based on haze weather is proposed in this paper. The algorithm in this paper mainly consists of two parts: The first part is MPGAN image dehazing, which uses a generative adversarial network to dehaze the image, and combines multi-scale convolution and perceptual loss. Multi-scale convolution is conducive to better feature extraction. The perceptual loss makes up for the shortcoming that the mean square error (MSE) is greatly affected by outliers; the second part is to recognize the license plate, first we use YOLOv3 to locate the license plate, the STN network corrects the license plate, and finally enters the improved LPRNet network to get license plate information. Experimental results show that the dehazing model proposed in this paper achieves good results, and the evaluation indicators PSNR and SSIM are better than other representative algorithms. After comparing the license plate recognition algorithm with the LPRNet algorithm, the average accuracy rate can reach 93.9%.

  • Anomaly Detection Using Spatio-Temporal Context Learned by Video Clip Sorting

    Wen SHAO  Rei KAWAKAMI  Takeshi NAEMURA  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/02/08
      Vol:
    E105-D No:5
      Page(s):
    1094-1102

    Previous studies on anomaly detection in videos have trained detectors in which reconstruction and prediction tasks are performed on normal data so that frames on which their task performance is low will be detected as anomalies during testing. This paper proposes a new approach that involves sorting video clips, by using a generative network structure. Our approach learns spatial contexts from appearances and temporal contexts from the order relationship of the frames. Experiments were conducted on four datasets, and we categorized the anomalous sequences by appearance and motion. Evaluations were conducted not only on each total dataset but also on each of the categories. Our method improved detection performance on both anomalies with different appearance and different motion from normality. Moreover, combining our approach with a prediction method produced improvements in precision at a high recall.

  • Unfolding Hidden Structures in Cyber-Physical Systems for Thorough STPA Analysis

    Sejin JUNG  Eui-Sub KIM  Junbeom YOO  

     
    LETTER-Software Engineering

      Pubricized:
    2022/02/10
      Vol:
    E105-D No:5
      Page(s):
    1103-1106

    Traditional safety analysis techniques have shown difficulties in incorporating dynamically changing structures of CPSs (Cyber-Physical Systems). STPA (System-Theoretic Process Analysis), one of the widely used, needs to unfold and arrange all hidden structures before beginning a full-fledged analysis. This paper proposes an intermediate model “Information Unfolding Model (IUM)” and a process “Information Unfolding Process (IUP)” to unfold dynamic structures which are hidden in CPSs and so help analysts construct control structures in STPA thoroughly.

  • Efficient Multi-Scale Feature Fusion for Image Manipulation Detection

    Yuxue ZHANG  Guorui FENG  

     
    LETTER-Information Network

      Pubricized:
    2022/02/03
      Vol:
    E105-D No:5
      Page(s):
    1107-1111

    Convolutional Neural Network (CNN) has made extraordinary progress in image classification tasks. However, it is less effective to use CNN directly to detect image manipulation. To address this problem, we propose an image filtering layer and a multi-scale feature fusion module which can guide the model more accurately and effectively to perform image manipulation detection. Through a series of experiments, it is shown that our model achieves improvements on image manipulation detection compared with the previous researches.

  • Neuron-Network-Based Mixture Probability Model for Passenger Walking Time Distribution Estimation

    Hao FANG  Chi-Hua CHEN  Dewang CHEN  Feng-Jang HWANG  

     
    LETTER-Artificial Intelligence, Data Mining

      Pubricized:
    2022/01/28
      Vol:
    E105-D No:5
      Page(s):
    1112-1115

    Aiming for accurate data-driven predictions for the passenger walking time, this study proposes a novel neuron-network-based mixture probability (NNBMP) model with repetition learning (RL) to estimate the probability density distribution of passenger walking time (PWT) in the metro station. Our conducted experiments for Fuzhou metro stations demonstrate that the proposed NNBMP-RL model achieved the mean absolute error, mean square error, and mean absolute percentage error of 0.0078, 1.33 × 10-4, and 19.41%, respectively, and it outperformed all the seven compared models. The developed NNBMP model fitting accurately the PWT distribution in the metro station is readily applicable to the microscopic analyses of passenger flow.

  • Stochastic Path Optimization to Improve Navigation Safety in Urban Environment

    Byungjae PARK  

     
    LETTER-Artificial Intelligence, Data Mining

      Pubricized:
    2022/02/15
      Vol:
    E105-D No:5
      Page(s):
    1116-1119

    This letter proposes a post-processing method to improve the smoothness and safety of the path for an autonomous vehicle navigating in an urban environment. The proposed method transforms the initial path given by local path planning algorithms using a stochastic approach to improve its smoothness and safety. Using the proposed method, the initial path is efficiently transformed by iteratively updating the position of each waypoint within it. The proposed method also guarantees the feasibility of the transformed path. Experimental results verify that the proposed method can improve the smoothness and safety of the initial path and ensure the feasibility of the transformed path.

  • A Deep Neural Network for Coarse-to-Fine Image Dehazing with Interleaved Residual Connections and Semi-Supervised Training

    Haoyu XU  Yuenan LI  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2022/01/28
      Vol:
    E105-D No:5
      Page(s):
    1125-1129

    In this letter, we propose a deep neural network and semi-supervised learning based dehazing algorithm. The dehazing network uses a pyramidal architecture to recover the haze-free scene from a single hazy image in a coarse-to-fine order. To faithfully restore the objects with different scales, we incorporate cascaded multi-scale convolutional blocks into each level of the pyramid. Feature fusion and transfer in the network are achieved using the paths constructed by interleaved residual connections. For better generalization to the complicated haze in real-world environments, we also devise a discriminator that enables semi-supervised adversarial training. Experimental results demonstrate that the proposed work outperforms comparative ones with higher quantitative metrics and more visually pleasant outputs. It can also enhance the robustness of object detection under haze.

  • Pairwise Similarity Normalization Based on a Hubness Score for Improving Cover Song Retrieval Accuracy

    Jin S. SEO  

     
    LETTER-Music Information Processing

      Pubricized:
    2022/02/21
      Vol:
    E105-D No:5
      Page(s):
    1130-1134

    A hubness-score based normalization of the pairwise similarity is proposed for the sequence-alignment based cover song retrieval. The hubness, which is the tendency of some data points in high-dimensional data sets to link more frequently to other points than the rest of the points from the set, is widely-known to deteriorate the information retrieval accuracy. This paper tries to relieve the performance degradation due to the hubness by normalizing the pairwise similarity with a hubness score. Experiments on two cover song datasets confirm that the proposed similarity normalization improves the cover song retrieval accuracy.

1621-1640hit(42807hit)