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[Keyword] Si(16405hit)

181-200hit(16405hit)

  • Effects of Parasitic Elements on L-Type LC/CL Matching Circuits Open Access

    Satoshi TANAKA  Takeshi YOSHIDA  Minoru FUJISHIMA  

     
    PAPER

      Pubricized:
    2023/11/07
      Vol:
    E107-A No:5
      Page(s):
    719-726

    L-type LC/CL matching circuits are well known for their simple analytical solutions and have been applied to many radio-frequency (RF) circuits. When actually constructing a circuit, parasitic elements are added to inductors and capacitors. Therefore, each L and C element has a self-resonant frequency, which affects the characteristics of the matching circuit. In this paper, the parallel parasitic capacitance to the inductor and the series parasitic inductor to the capacitance are taken up as parasitic elements, and the details of the effects of the self-resonant frequency of each element on the S11, voltage standing wave ratio (VSWR) and S21 characteristics are reported. When a parasitic element is added, each characteristic basically tends to deteriorate as the self-resonant frequency decreases. However, as an interesting feature, we found that the combination of resonant frequencies determines the VSWR and passband characteristics, regardless of whether it is the inductor or the capacitor.

  • RC-Oscillator-Based Battery-Less Wireless Sensing System Using RF Resonant Electromagnetic Coupling Open Access

    Zixuan LI  Sangyeop LEE  Noboru ISHIHARA  Hiroyuki ITO  

     
    PAPER

      Pubricized:
    2023/11/24
      Vol:
    E107-A No:5
      Page(s):
    727-740

    A wireless sensor terminal module of 5cc size (2.5 cm × 2.5 cm × 0.8 cm) that does not require a battery is proposed by integrating three kinds of circuit technologies. (i) a low-power sensor interface: an FM modulation type CMOS sensor interface circuit that can operate with a typical power consumption of 24.5 μW was fabricated by the 0.7-μm CMOS process technology. (ii) power supply to the sensor interface circuit: a wireless power transmission characteristic to a small-sized PCB spiral coil antenna was clarified and applied to the module. (iii) wireless sensing from the module: backscatter communication technology that modulates the signal from the base terminal equipment with sensor information and reflects it, which is used for the low-power sensing operation. The module fabricated includes a rectifier circuit with the PCB spiral coil antenna that receives wireless power transmitted from base terminal equipment by electromagnetic resonance coupling and converts it into DC power and a sensor interface circuit that operates using the power. The interface circuit modulates the received signal with the sensor information and reflects it back to the base terminal. The module could achieve 100 mm communication distance when 0.4 mW power is feeding to the sensor terminal.

  • 150 GHz Fundamental Oscillator Utilizing Transmission-Line-Based Inter-Stage Matching in 130 nm SiGe BiCMOS Technology Open Access

    Sota KANO  Tetsuya IIZUKA  

     
    LETTER

      Pubricized:
    2023/12/05
      Vol:
    E107-A No:5
      Page(s):
    741-745

    A 150 GHz fundamental oscillator employing an inter-stage matching network based on a transmission line is presented in this letter. The proposed oscillator consists of a two-stage common-emitter amplifier loop, whose inter-stage connections are optimized to meet the oscillation condition. The oscillator is designed in a 130-nm SiGe BiCMOS process that offers fT and fMAX of 350 GHz and 450 GHz. According to simulation results, an output power of 3.17 dBm is achieved at 147.6 GHz with phase noise of -115 dBc/Hz at 10 MHz offset and figure-of-merit (FoM) of -180 dBc/Hz.

  • Investigation and Improvement on Self-Dithered MASH ΔΣ Modulator for Fractional-N Frequency Synthesis Open Access

    Yuyang ZHU  Zunsong YANG  Masaru OSADA  Haoming ZHANG  Tetsuya IIZUKA  

     
    LETTER

      Pubricized:
    2023/12/05
      Vol:
    E107-A No:5
      Page(s):
    746-750

    Self-dithered digital delta-sigma modulators (DDSMs) are commonly used in fractional-N frequency synthesizers due to their ability to eliminate unwanted spurs from the synthesizer’s spectra without requiring additional hardware. However, when operating with a low-bit input, self-dithered DDSMs can still suffer from spurious tones at certain inputs. In this paper, we propose a self-dithered MASH 1-1-1-1 structure to mitigate the spur issue in the self-dithered MASH DDSMs. The proposed self-dithered MASH 1-1-1-1 suppresses the spurs with shaped dithering and achieves 4th order noise shaping.

  • Output Feedback Ultimate Boundedness Control with Decentralized Event-Triggering Open Access

    Koichi KITAMURA  Koichi KOBAYASHI  Yuh YAMASHITA  

     
    PAPER

      Pubricized:
    2023/11/10
      Vol:
    E107-A No:5
      Page(s):
    770-778

    In cyber-physical systems (CPSs) that interact between physical and information components, there are many sensors that are connected through a communication network. In such cases, the reduction of communication costs is important. Event-triggered control that the control input is updated only when the measured value is widely changed is well known as one of the control methods of CPSs. In this paper, we propose a design method of output feedback controllers with decentralized event-triggering mechanisms, where the notion of uniformly ultimate boundedness is utilized as a control specification. Using this notion, we can guarantee that the state stays within a certain set containing the origin after a certain time, which depends on the initial state. As a result, the number of times that the event occurs can be decreased. First, the design problem is formulated. Next, this problem is reduced to a BMI (bilinear matrix inequality) optimization problem, which can be solved by solving multiple LMI (linear matrix inequality) optimization problems. Finally, the effectiveness of the proposed method is presented by a numerical example.

  • A Feedback Vertex Set-Based Approach to Simplifying Probabilistic Boolean Networks Open Access

    Koichi KOBAYASHI  

     
    PAPER

      Pubricized:
    2023/09/26
      Vol:
    E107-A No:5
      Page(s):
    779-785

    A PBN is well known as a mathematical model of complex network systems such as gene regulatory networks. In Boolean networks, interactions between nodes (e.g., genes) are modeled by Boolean functions. In PBNs, Boolean functions are switched probabilistically. In this paper, for a PBN, a simplified representation that is effective in analysis and control is proposed. First, after a polynomial representation of a PBN is briefly explained, a simplified representation is derived. Here, the steady-state value of the expected value of the state is focused, and is characterized by a minimum feedback vertex set of an interaction graph expressing interactions between nodes. Next, using this representation, input selection and stabilization are discussed. Finally, the proposed method is demonstrated by a biological example.

  • A BDD-Based Approach to Finite-Time Control of Boolean Networks Open Access

    Fuma MOTOYAMA  Koichi KOBAYASHI  Yuh YAMASHITA  

     
    PAPER

      Pubricized:
    2023/10/23
      Vol:
    E107-A No:5
      Page(s):
    793-798

    Control of complex networks such as gene regulatory networks is one of the fundamental problems in control theory. A Boolean network (BN) is one of the mathematical models in complex networks, and represents the dynamic behavior by Boolean functions. In this paper, a solution method for the finite-time control problem of BNs is proposed using a BDD (binary decision diagram). In this problem, we find all combinations of the initial state and the control input sequence such that a certain control specification is satisfied. The use of BDDs enables us to solve this problem for BNs such that the conventional method cannot be applied. First, after the outline of BNs and BDDs is explained, the problem studied in this paper is given. Next, a solution method using BDDs is proposed. Finally, a numerical example on a 67-node BN is presented.

  • Consensus-Based Distributed Exp3 Policy Over Directed Time-Varying Networks Open Access

    Tomoki NAKAMURA  Naoki HAYASHI  Masahiro INUIGUCHI  

     
    PAPER

      Pubricized:
    2023/10/16
      Vol:
    E107-A No:5
      Page(s):
    799-805

    In this paper, we consider distributed decision-making over directed time-varying multi-agent systems. We consider an adversarial bandit problem in which a group of agents chooses an option from among multiple arms to maximize the total reward. In the proposed method, each agent cooperatively searches for the optimal arm with the highest reward by a consensus-based distributed Exp3 policy. To this end, each agent exchanges the estimation of the reward of each arm and the weight for exploitation with the nearby agents on the network. To unify the explored information of arms, each agent mixes the estimation and the weight of the nearby agents with their own values by a consensus dynamics. Then, each agent updates the probability distribution of arms by combining the Hedge algorithm and the uniform search. We show that the sublinearity of a pseudo-regret can be achieved by appropriately setting the parameters of the distributed Exp3 policy.

  • Prohibited Item Detection Within X-Ray Security Inspection Images Based on an Improved Cascade Network Open Access

    Qingqi ZHANG  Xiaoan BAO  Ren WU  Mitsuru NAKATA  Qi-Wei GE  

     
    PAPER

      Pubricized:
    2024/01/16
      Vol:
    E107-A No:5
      Page(s):
    813-824

    Automatic detection of prohibited items is vital in helping security staff be more efficient while improving the public safety index. However, prohibited item detection within X-ray security inspection images is limited by various factors, including the imbalance distribution of categories, diversity of prohibited item scales, and overlap between items. In this paper, we propose to leverage the Poisson blending algorithm with the Canny edge operator to alleviate the imbalance distribution of categories maximally in the X-ray images dataset. Based on this, we improve the cascade network to deal with the other two difficulties. To address the prohibited scale diversity problem, we propose the Re-BiFPN feature fusion method, which includes a coordinate attention atrous spatial pyramid pooling (CA-ASPP) module and a recursive connection. The CA-ASPP module can implicitly extract direction-aware and position-aware information from the feature map. The recursive connection feeds the CA-ASPP module processed multi-scale feature map to the bottom-up backbone layer for further multi-scale feature extraction. In addition, a Rep-CIoU loss function is designed to address the overlapping problem in X-ray images. Extensive experimental results demonstrate that our method can successfully identify ten types of prohibited items, such as Knives, Scissors, Pressure, etc. and achieves 83.4% of mAP, which is 3.8% superior to the original cascade network. Moreover, our method outperforms other mainstream methods by a significant margin.

  • A Multiobjective Approach for Side-Channel Based Hardware Trojan Detection Using Power Traces Open Access

    Priyadharshini MOHANRAJ  Saravanan PARAMASIVAM  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2023/08/23
      Vol:
    E107-A No:5
      Page(s):
    825-835

    The detection of hardware trojans has been extensively studied in the past. In this article, we propose a side-channel analysis technique that uses a wrapper-based feature selection technique for hardware trojan detection. The whale optimization algorithm is modified to carefully extract the best feature subset. The aim of the proposed technique is multiobjective: improve the accuracy and minimize the number of features. The power consumption traces measured from AES-128 trojan circuits are used as features in this experiment. The stabilizing property of the feature selection method helps to bring a mutual trade-off between the precision and recall parameters thereby minimizing the number of false negatives. The proposed hardware trojan detection scheme produces a maximum of 10.3% improvement in accuracy and reduction up to a single feature by employing the modified whale optimization technique. Thus the evaluation results conducted on various trust-hub cryptographic benchmark circuits prove to be efficient from the existing state-of-art methods.

  • Dance-Conditioned Artistic Music Generation by Creative-GAN Open Access

    Jiang HUANG  Xianglin HUANG  Lifang YANG  Zhulin TAO  

     
    PAPER-Multimedia Environment Technology

      Pubricized:
    2023/08/23
      Vol:
    E107-A No:5
      Page(s):
    836-844

    We present a novel adversarial, end-to-end framework based on Creative-GAN to generate artistic music conditioned on dance videos. Our proposed framework takes the visual and motion posture data as input, and then adopts a quantized vector as the audio representation to generate complex music corresponding to input. However, the GAN algorithm just imitate and reproduce works what humans have created, instead of generating something new and creative. Therefore, we newly introduce Creative-GAN, which extends the original GAN framework to two discriminators, one is to determine whether it is real music, and the other is to classify music style. The paper shows that our proposed Creative-GAN can generate novel and interesting music which is not found in the training dataset. To evaluate our model, a comprehensive evaluation scheme is introduced to make subjective and objective evaluation. Compared with the advanced methods, our experimental results performs better in measureing the music rhythm, generation diversity, dance-music correlation and overall quality of generated music.

  • High-Throughput Exact Matching Implementation on FPGA with Shared Rule Tables among Parallel Pipelines Open Access

    Xiaoyong SONG  Zhichuan GUO  Xinshuo WANG  Mangu SONG  

     
    PAPER-Network System

      Vol:
    E107-B No:5
      Page(s):
    387-397

    In software defined network (SDN), packet processing is commonly implemented using match-action model, where packets are processed based on matched actions in match action table. Due to the limited FPGA on-board resources, it is an important challenge to achieve large-scale high throughput based on exact matching (EM), while solving hash conflicts and out-of-order problems. To address these issues, this study proposed an FPGA-based EM table that leverages shared rule tables across multiple pipelines to eliminate memory replication and enhance overall throughput. An out-of-order reordering function is used to ensure packet sequencing within the pipelines. Moreover, to handle collisions and increase load factor of hash table, multiple hash table blocks are combined and an auxiliary CAM-based EM table is integrated in each pipeline. To the best of our knowledge, this is the first time that the proposed design considers the recovery of out-of-order operations in multi-channel EM table for high-speed network packets processing application. Furthermore, it is implemented on Xilinx Alveo U250 field programmable gate arrays, which has a million rules and achieves a processing speed of 200 million operations per second, theoretically enabling throughput exceeding 100 Gbps for 64-Byte size packets.

  • Traffic Reduction for Speculative Video Transmission in Cloud Gaming Systems Open Access

    Takumasa ISHIOKA  Tatsuya FUKUI  Toshihito FUJIWARA  Satoshi NARIKAWA  Takuya FUJIHASHI  Shunsuke SARUWATARI  Takashi WATANABE  

     
    PAPER-Network

      Vol:
    E107-B No:5
      Page(s):
    408-418

    Cloud gaming systems allow users to play games that require high-performance computational capability on their mobile devices at any location. However, playing games through cloud gaming systems increases the Round-Trip Time (RTT) due to increased network delay. To simulate a local gaming experience for cloud users, we must minimize RTTs, which include network delays. The speculative video transmission pre-generates and encodes video frames corresponding to all possible user inputs and sends them to the user before the user’s input. The speculative video transmission mitigates the network, whereas a simple solution significantly increases the video traffic. This paper proposes tile-wise delta detection for traffic reduction of speculative video transmission. More specifically, the proposed method determines a reference video frame from the generated video frames and divides the reference video frame into multiple tiles. We calculate the similarity between each tile of the reference video frame and other video frames based on a hash function. Based on calculated similarity, we determine redundant tiles and do not transmit them to reduce traffic volume in minimal processing time without implementing a high compression ratio video compression technique. Evaluations using commercial games showed that the proposed method reduced 40-50% in traffic volume when the SSIM index was around 0.98 in certain genres, compared with the speculative video transmission method. Furthermore, to evaluate the feasibility of the proposed method, we investigated the effectiveness of network delay reduction with existing computational capability and the requirements in the future. As a result, we found that the proposed scheme may mitigate network delay by one to two frames, even with existing computational capability under limited conditions.

  • An Extension of Physical Optics Approximation for Dielectric Wedge Diffraction for a TM-Polarized Plane Wave Open Access

    Duc Minh NGUYEN  Hiroshi SHIRAI  Se-Yun KIM  

     
    PAPER-Electromagnetic Theory

      Pubricized:
    2023/11/08
      Vol:
    E107-C No:5
      Page(s):
    115-123

    In this study, the edge diffraction of a TM-polarized electromagnetic plane wave by two-dimensional dielectric wedges has been analyzed. An asymptotic solution for the radiation field has been derived from equivalent electric and magnetic currents which can be determined by the geometrical optics (GO) rays. This method may be regarded as an extended version of physical optics (PO). The diffracted field has been represented in terms of cotangent functions whose singularity behaviors are closely related to GO shadow boundaries. Numerical calculations are performed to compare the results with those by other reference solutions, such as the hidden rays of diffraction (HRD) and a numerical finite-difference time-domain (FDTD) simulation. Comparisons of the diffraction effect among these results have been made to propose additional lateral waves in the denser media.

  • Simplified Reactive Torque Model Predictive Control of Induction Motor with Common Mode Voltage Suppression Open Access

    Siyao CHU  Bin WANG  Xinwei NIU  

     
    PAPER-Electronic Instrumentation and Control

      Pubricized:
    2023/11/30
      Vol:
    E107-C No:5
      Page(s):
    132-140

    To reduce the common mode voltage (CMV), suppress the CMV spikes, and improve the steady-state performance, a simplified reactive torque model predictive control (RT-MPC) for induction motors (IMs) is proposed. The proposed prediction model can effectively reduce the complexity of the control algorithm with the direct torque control (DTC) based voltage vector (VV) preselection approach. In addition, the proposed CMV suppression strategy can restrict the CMV within ±Vdc/6, and does not require the exclusion of non-adjacent non-opposite VVs, thus resulting in the system showing good steady-state performance. The effectiveness of the proposed design has been tested and verified by the practical experiment. The proposed algorithm can reduce the execution time by an average of 26.33% compared to the major competitors.

  • Analysis of Optical Power Splitter with Resonator Structure Constructed by Two-Dimensional MDM Plasmonic Waveguide Open Access

    Yoshihiro NAKA  Masahiko NISHIMOTO  Mitsuhiro YOKOTA  

     
    BRIEF PAPER-Electromagnetic Theory

      Pubricized:
    2023/12/07
      Vol:
    E107-C No:5
      Page(s):
    141-145

    An efficient optical power splitter constructed by a metal-dielectric-metal plasmonic waveguide with a resonator structure has been analyzed. The method of solution is the finite difference time domain (FD-TD) method with the piecewise linear recursive convolution (PLRC) method. The resonator structure consists of input/output waveguides and a narrow waveguide with a T-junction. The power splitter with the resonator structure is expressed by an equivalent transmission-line circuit. We can find that the transmittance and reflectance calculated by the FD-TD method and the equivalent circuit are matched when the difference in width between the input/output waveguides and the narrow waveguide is small. It is also shown that the transmission wavelength can be adjusted by changing the narrow waveguide lengths that satisfy the impedance matching condition in the equivalent circuit.

  • Changes in Reading Voice to Convey Design Intention for Users with Visual Impairment Open Access

    Junko SHIROGANE  Daisuke SAYAMA  Hajime IWATA  Yoshiaki FUKAZAWA  

     
    PAPER

      Pubricized:
    2023/12/27
      Vol:
    E107-D No:5
      Page(s):
    589-601

    Webpage texts are often emphasized by decorations such as bold, italic, underline, and text color using HTML (HyperText Markup Language) tags and CSS (Cascading Style Sheets). However, users with visual impairment often struggle to recognize decorations appropriately because most screen readers do not read decorations appropriately. To overcome this limitation, we propose a method to read emphasized texts by changing the reading voice parameters of a screen reader and adding sound effects. First, the strong emphasis types and reading voices are investigated. Second, the intensity of the emphasis type is used to calculate a score. Then the score is used to assign the reading method for the emphasized text. Finally, the proposed method is evaluated by users with and without visual impairment. The proposed method can convey emphasized texts, but future improvements are necessary.

  • Locating Concepts on Use Case Steps in Source Code Open Access

    Shinpei HAYASHI  Teppei KATO  Motoshi SAEKI  

     
    PAPER

      Pubricized:
    2023/12/20
      Vol:
    E107-D No:5
      Page(s):
    602-612

    Use case descriptions describe features consisting of multiple concepts with following a procedural flow. Because existing feature location techniques lack a relation between concepts in such features, it is difficult to identify the concepts in the source code with high accuracy. This paper presents a technique to locate concepts in a feature described in a use case description consisting of multiple use case steps using dependency between them. We regard each use case step as a description of a concept and apply an existing concept location technique to the descriptions of concepts and obtain lists of modules. Also, three types of dependencies: time, call, and data dependencies among use case steps are extracted based on their textual description. Modules in the obtained lists failing to match the dependency between concepts are filtered out. Thus, we can obtain more precise lists of modules. We have applied our technique to use case descriptions in a benchmark. Results show that our technique outperformed baseline setting without applying the filtering.

  • A Personalised Session-Based Recommender System with Sequential Updating Based on Aggregation of Item Embeddings Open Access

    Yuma NAGI  Kazushi OKAMOTO  

     
    PAPER

      Pubricized:
    2024/01/09
      Vol:
    E107-D No:5
      Page(s):
    638-649

    The study proposes a personalised session-based recommender system that embeds items by using Word2Vec and sequentially updates the session and user embeddings with the hierarchicalization and aggregation of item embeddings. To process a recommendation request, the system constructs a real-time user embedding that considers users’ general preferences and sequential behaviour to handle short-term changes in user preferences with a low computational cost. The system performance was experimentally evaluated in terms of the accuracy, diversity, and novelty of the ranking of recommended items and the training and prediction times of the system for three different datasets. The results of these evaluations were then compared with those of the five baseline systems. According to the evaluation experiment, the proposed system achieved a relatively high recommendation accuracy compared with baseline systems and the diversity and novelty scores of the proposed system did not fall below 90% for any dataset. Furthermore, the training times of the Word2Vec-based systems, including the proposed system, were shorter than those of FPMC and GRU4Rec. The evaluation results suggest that the proposed recommender system succeeds in keeping the computational cost for training low while maintaining high-level recommendation accuracy, diversity, and novelty.

  • Automated Labeling of Entities in CVE Vulnerability Descriptions with Natural Language Processing Open Access

    Kensuke SUMOTO  Kenta KANAKOGI  Hironori WASHIZAKI  Naohiko TSUDA  Nobukazu YOSHIOKA  Yoshiaki FUKAZAWA  Hideyuki KANUKA  

     
    PAPER

      Pubricized:
    2024/02/09
      Vol:
    E107-D No:5
      Page(s):
    674-682

    Security-related issues have become more significant due to the proliferation of IT. Collating security-related information in a database improves security. For example, Common Vulnerabilities and Exposures (CVE) is a security knowledge repository containing descriptions of vulnerabilities about software or source code. Although the descriptions include various entities, there is not a uniform entity structure, making security analysis difficult using individual entities. Developing a consistent entity structure will enhance the security field. Herein we propose a method to automatically label select entities from CVE descriptions by applying the Named Entity Recognition (NER) technique. We manually labeled 3287 CVE descriptions and conducted experiments using a machine learning model called BERT to compare the proposed method to labeling with regular expressions. Machine learning using the proposed method significantly improves the labeling accuracy. It has an f1 score of about 0.93, precision of about 0.91, and recall of about 0.95, demonstrating that our method has potential to automatically label select entities from CVE descriptions.

181-200hit(16405hit)

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