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[Keyword] CAD(177hit)

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  • Precise Design of an 11-Pole TM010 Mode Dielectric Resonator BPF with Novel Capacitive Coupling Structures Open Access

    Fan LIU  Zhewang MA  Masataka OHIRA  Dongchun QIAO  Guosheng PU  Masaru ICHIKAWA  

     
    PAPER

      Pubricized:
    2024/03/22
      Vol:
    E107-C No:11
      Page(s):
    472-478

    In this paper, a precise design method of high-order bandpass filters (BPFs) with complicated coupling topologies is proposed, and is demonstrated through the design of an 11-pole BPF using TM010 mode dielectric resonators (DRs). A novel Z-shaped coupling structure is proposed which avoids the mixed use of TM010 and TM01δ modes and enables the tuning and assembling of the filter much easier. The coupling topology of the BPF includes three cascade triplets (CTs) of DRs, and both the capacitive and inductive couplings in the CTs are designed independently tunable, which produce consequently three controllable transmission zeros on both sides of the passband of filter. A procedure of mapping the coupling matrix of BPF to its physical dimensions is developed, and an iterative optimization of these physical dimensions is implemented to achieve best performance. The design of the 11-pole BPF is shown highly precise by the excellent agreement between the electromagnetic simulated response of the filter and the desired target specifications.

  • Determination Method of Cascaded Number for Lumped Parameter Models Oriented to Transmission Lines Open Access

    Risheng QIN  Hua KUANG  He JIANG  Hui YU  Hong LI  Zhuan LI  

     
    PAPER-Electronic Circuits

      Pubricized:
    2023/12/20
      Vol:
    E107-C No:7
      Page(s):
    201-209

    This paper proposes a determination method of the cascaded number for lumped parameter models (LPMs) of the transmission lines. The LPM is used to simulate long-distance transmission lines, and the cascaded number significantly impacts the simulation results. Currently, there is a lack of a system-level determination method of the cascaded number for LPMs. Based on the theoretical analysis and eigenvalue decomposition of network matrix, this paper discusses the error in resonance characteristics between distributed parameter model and LPMs. Moreover, it is deduced that optimal cascaded numbers of the cascaded π-type and T-type LPMs are the same, and the Γ-type LPM has a lowest analog accuracy. The principle that the maximum simulation frequency is less than the first resonance frequency of each segment is presented. According to the principle, optimal cascaded numbers of cascaded π-type, T-type, and Γ-type LPMs are obtained. The effectiveness of the proposed determination method is verified by simulation.

  • Two-Phase Approach to Finding the Most Critical Entities in Interdependent Systems Open Access

    Daichi MINAMIDE  Tatsuhiro TSUCHIYA  

     
    PAPER

      Pubricized:
    2023/09/20
      Vol:
    E107-A No:5
      Page(s):
    786-792

    In interdependent systems, such as electric power systems, entities or components mutually depend on each other. Due to these interdependencies, a small number of initial failures can propagate throughout the system, resulting in catastrophic system failures. This paper addresses the problem of finding the set of entities whose failures will have the worst effects on the system. To this end, a two-phase algorithm is developed. In the first phase, the tight bound on failure propagation steps is computed using a Boolean Satisfiablility (SAT) solver. In the second phase, the problem is formulated as an Integer Linear Programming (ILP) problem using the obtained step bound and solved with an ILP solver. Experimental results show that the algorithm scales to large problem instances and outperforms a single-phase algorithm that uses a loose step bound.

  • An Academic Presentation Support System Utilizing Structural Elements Open Access

    Kazuma TAKAHASHI  Wen GU  Koichi OTA  Shinobu HASEGAWA  

     
    PAPER

      Pubricized:
    2023/12/27
      Vol:
    E107-D No:4
      Page(s):
    486-494

    In academic presentation, the structure design of presentation is critical for making the presentation logical and understandable. However, it is difficult for novice researchers to construct required academic presentation structure due to the flexibility in structure creation. To help novice researchers revise and improve their presentation structure, we propose an academic presentation structure modification support system based on structural elements of the presentation slides. In the proposed system, we build a presentation structural elements model (PSEM) that represents the essential structural elements and their relations to clarify the ideal structure of academic presentation. Based on the PSEM, we also designed two evaluation indices to evaluate the academic presentation structure. To evaluate the proposed system with real-world data, we construct a web application that generates evaluation and feedback to academic presentation slides. The experimental results demonstrate the effectiveness of the proposed system.

  • Two Cascade Control Strategy of Generalized Electric Spring

    Xiaohu WANG  Yubin DUAN  Yi WEI  Xinyuan CHEN  Huang ZHUN  Chaohui ZHAO  

     
    PAPER-Energy in Electronics Communications

      Pubricized:
    2023/06/05
      Vol:
    E106-B No:11
      Page(s):
    1102-1108

    With the gradually increase of the application of new energy in microgrids, Electric Spring (ES), as a new type of distributed compensation power electronic device has been widely studied. The Generalized Electric Spring (G-ES) is an improved topology, and the space limitation problem in the traditional topology is solved. Because of the mode of G-ES use in the power grid, a reasonable solution to the voltage loss of the critical section feeder is needed. In this paper, the voltage balance equation based on the feedforward compensation coefficient is established, and a two cascade control strategy based on the equation is studied. The first stage of the two cascade control strategy is to use communication means to realize the allocation of feedforward compensation coefficients, and the second stage is to use the coefficients to realize feedforward fixed angle control. Simulation analysis shows that the proposed control strategy does not affect the control accuracy of the critical load (CL), and effectively improves the operational range of the G-ES.

  • A Multitask Learning Approach Based on Cascaded Attention Network and Self-Adaption Loss for Speech Emotion Recognition

    Yang LIU  Yuqi XIA  Haoqin SUN  Xiaolei MENG  Jianxiong BAI  Wenbo GUAN  Zhen ZHAO  Yongwei LI  

     
    PAPER-Speech and Hearing

      Pubricized:
    2022/12/08
      Vol:
    E106-A No:6
      Page(s):
    876-885

    Speech emotion recognition (SER) has been a complex and difficult task for a long time due to emotional complexity. In this paper, we propose a multitask deep learning approach based on cascaded attention network and self-adaption loss for SER. First, non-personalized features are extracted to represent the process of emotion change while reducing external variables' influence. Second, to highlight salient speech emotion features, a cascade attention network is proposed, where spatial temporal attention can effectively locate the regions of speech that express emotion, while self-attention reduces the dependence on external information. Finally, the influence brought by the differences in gender and human perception of external information is alleviated by using a multitask learning strategy, where a self-adaption loss is introduced to determine the weights of different tasks dynamically. Experimental results on IEMOCAP dataset demonstrate that our method gains an absolute improvement of 1.97% and 0.91% over state-of-the-art strategies in terms of weighted accuracy (WA) and unweighted accuracy (UA), respectively.

  • Design and Analysis of Si/CaF2 Near-Infrared (λ∼1.7µm) DFB Quantum Cascade Laser for Silicon Photonics

    Gensai TEI  Long LIU  Masahiro WATANABE  

     
    PAPER-Lasers, Quantum Electronics

      Pubricized:
    2022/11/04
      Vol:
    E106-C No:5
      Page(s):
    157-164

    We have designed a near-infrared wavelength Si/CaF2 DFB quantum cascade laser and investigated the possibility of single-mode laser oscillation by analysis of the propagation mode, gain, scattering time of Si quantum well, and threshold current density. As the waveguide and resonator, a slab-type waveguide structure with a Si/CaF2 active layer sandwiched by SiO2 on a Si (111) substrate and a grating structure in an n-Si conducting layer were assumed. From the results of optical propagation mode analysis, by assuming a λ/4-shifted bragg waveguide structure, it was found that the single vertical and horizontal TM mode propagation is possible at the designed wavelength of 1.70µm. In addition, a design of the active layer is proposed and its current injection capability is roughly estimated to be 25.1kA/cm2, which is larger than required threshold current density of 1.4kA/cm2 calculated by combining analysis results of the scattering time, population inversion, gain of quantum cascade lasers, and coupling theory of a Bragg waveguide. The results strongly indicate the possibility of single-mode laser oscillation.

  • An eFPGA Generation Suite with Customizable Architecture and IDE

    Morihiro KUGA  Qian ZHAO  Yuya NAKAZATO  Motoki AMAGASAKI  Masahiro IIDA  

     
    PAPER

      Pubricized:
    2022/10/07
      Vol:
    E106-A No:3
      Page(s):
    560-574

    From edge devices to cloud servers, providing optimized hardware acceleration for specific applications has become a key approach to improve the efficiency of computer systems. Traditionally, many systems employ commercial field-programmable gate arrays (FPGAs) to implement dedicated hardware accelerator as the CPU's co-processor. However, commercial FPGAs are designed in generic architectures and are provided in the form of discrete chips, which makes it difficult to meet increasingly diversified market needs, such as balancing reconfigurable hardware resources for a specific application, or to be integrated into a customer's system-on-a-chip (SoC) in the form of embedded FPGA (eFPGA). In this paper, we propose an eFPGA generation suite with customizable architecture and integrated development environment (IDE), which covers the entire eFPGA design generation, testing, and utilization stages. For the eFPGA design generation, our intellectual property (IP) generation flow can explore the optimal logic cell, routing, and array structures for given target applications. For the testability, we employ a previously proposed shipping test method that is 100% accurate at detecting all stuck-at faults in the entire FPGA-IP. In addition, we propose a user-friendly and customizable Web-based IDE framework for the generated eFPGA based on the NODE-RED development framework. In the case study, we show an eFPGA architecture exploration example for a differential privacy encryption application using the proposed suite. Then we show the implementation and evaluation of the eFPGA prototype with a 55nm test element group chip design.

  • Critical Location of Communications Network with Power Grid Power Supply Open Access

    Hiroshi SAITO  

     
    PAPER-Network Management/Operation

      Pubricized:
    2022/08/10
      Vol:
    E106-B No:2
      Page(s):
    166-173

    When a disaster hits a network, network service disruptions can occur even if the network facilities have survived and battery and power generators are provided. This is because in the event of a disaster, the power supply will not be restarted within the lifetime of the battery or oil transportation will not be restarted before running out of oil and power will be running out. Therefore, taking a power grid into account is important. This paper proposes a polynomial-time algorithm to identify the critical location C*D of a communications network Nc when a disaster hits. Electrical power grid Np supplies power to the nodes of Nc, and a link in Nc is disconnected when a node or a link in Nc or Np fails. Here, the disaster area is modeled as co-centric disks and the failure probability is higher in the inner disk than the outer one. The location of the center of the disaster with the greatest expected number of disconnected links in Nc is taken as the critical location C*D.

  • Design, Fabrication, and Evaluation of Waveguide Structure Using Si/CaF2 Heterostructure for Near- and Mid- Infrared Silicon Photonics

    Long LIU  Gensai TEI  Masahiro WATANABE  

     
    PAPER-Lasers, Quantum Electronics

      Pubricized:
    2022/07/08
      Vol:
    E106-C No:1
      Page(s):
    1-6

    We have proposed integrated waveguide structure suitable for mid- and near- infrared light propagation using Si and CaF2 heterostructures on Si substrate. Using a fabrication process based on etching, lithography and crystal growth techniques, we have formed a slab-waveguide structure with a current injection mechanism on a SOI substrate, which would be a key component for Si/CaF2 quantum cascade lasers and other optical integrated systems. The propagation of light at a wavelength of 1.55 µm through a Si/CaF2 waveguide structure have been demonstrated for the first time using a structure with a Si/CaF2 multilayered core with 610-nm-thick, waveguide width of 970 nm, which satisfies single-mode condition in the horizontal direction within a tolerance of fabrication accuracy. The waveguide loss for transverse magnetic (TM) mode has been evaluated to be 51.4 cm-1. The cause of the loss was discussed by estimating the edge roughness scattering and free carrier absorption, which suggests further reduction of the loss would be possible.

  • Anomaly Prediction for Wind Turbines Using an Autoencoder with Vibration Data Supported by Power-Curve Filtering

    Masaki TAKANASHI  Shu-ichi SATO  Kentaro INDO  Nozomu NISHIHARA  Hiroki HAYASHI  Toru SUZUKI  

     
    LETTER-Artificial Intelligence, Data Mining

      Pubricized:
    2021/12/07
      Vol:
    E105-D No:3
      Page(s):
    732-735

    The prediction of the malfunction timing of wind turbines is essential for maintaining the high profitability of the wind power generation industry. Studies have been conducted on machine learning methods that use condition monitoring system data, such as vibration data, and supervisory control and data acquisition (SCADA) data to detect and predict anomalies in wind turbines automatically. Autoencoder-based techniques that use unsupervised learning where the anomaly pattern is unknown have attracted significant interest in the area of anomaly detection and prediction. In particular, vibration data are considered useful because they include the changes that occur in the early stages of a malfunction. However, when autoencoder-based techniques are applied for prediction purposes, in the training process it is difficult to distinguish the difference between operating and non-operating condition data, which leads to the degradation of the prediction performance. In this letter, we propose a method in which both vibration data and SCADA data are utilized to improve the prediction performance, namely, a method that uses a power curve composed of active power and wind speed. We evaluated the method's performance using vibration and SCADA data obtained from an actual wind farm.

  • A Proof of Work Based on Key Recovery Problem of Cascade Block Ciphers with ASIC Resistance

    Takaki ASANUMA  Takanori ISOBE  

     
    PAPER

      Pubricized:
    2021/11/08
      Vol:
    E105-D No:2
      Page(s):
    248-255

    Hashcash, which is a Proof of Work (PoW) of bitcoin, is based on a preimage problem of hash functions of SHA-2 and RIPEMD. As these hash functions employ the Merkle-Damgard (MD) construction, a preimage can be found with negligible memory. Since such calculations can be accelerated by dedicated ASICs, it has a potential risk of a so-called 51% attack. To address this issue, we propose a new PoW scheme based on the key recovery problem of cascade block ciphers. By choosing the appropriate parameters, e.g., block sizes and key sizes of underlying block ciphers, we can make this problem a memory-hard problem such that it requires a lot of memory to efficiently solve it. Besides, we can independently adjust the required time complexity and memory complexity, according to requirements by target applications and progress of computational power.

  • A Study on the Increase of Perceivable Information in the Saccade with High Speed Line Display Open Access

    Naoki KAWASAKI  Yuuki MACHIDA  Takayuki MISU  Keiichi ABE  Hiroshi SUGIMURA  Makiko OKUMURA  

     
    INVITED PAPER

      Pubricized:
    2021/08/17
      Vol:
    E105-C No:2
      Page(s):
    72-78

    A line display that utilizes saccade has been proposed. When an observer moves his or her eyes on a one-dimensional fixed line display, two-dimensional information is perceived on the retina. In this paper, a high speed flashing line display was developed using a CPLD and PIC microcontroller. The flashing period was reduced to 20 µs, which was less than half that of our previous system. The relationship between the flashing frequency and the optimum distance that can be perceived with the least distortion was clarified. The results show that the higher the flashing frequency is, the more information can be perceived from a farther position. Calculated values, which were based on the relationship between the flashing period and the width of the light source, were almost identical with measured values at the flashing frequencies from 3.3 kHz to 10 kHz. Due to short flashing period, the developed line display not only was visible at distance of 15 m or more, which is suitable for outdoor use, but also realized 16 gray levels.

  • Feasibility Study for Computer-Aided Diagnosis System with Navigation Function of Clear Region for Real-Time Endoscopic Video Image on Customizable Embedded DSP Cores

    Masayuki ODAGAWA  Tetsushi KOIDE  Toru TAMAKI  Shigeto YOSHIDA  Hiroshi MIENO  Shinji TANAKA  

     
    LETTER-VLSI Design Technology and CAD

      Pubricized:
    2021/07/08
      Vol:
    E105-A No:1
      Page(s):
    58-62

    This paper presents examination result of possibility for automatic unclear region detection in the CAD system for colorectal tumor with real time endoscopic video image. We confirmed that it is possible to realize the CAD system with navigation function of clear region which consists of unclear region detection by YOLO2 and classification by AlexNet and SVMs on customizable embedded DSP cores. Moreover, we confirmed the real time CAD system can be constructed by a low power ASIC using customizable embedded DSP cores.

  • Design and Performance of Low-Density Parity-Check Codes for Noisy Channels with Synchronization Errors

    Ryo SHIBATA  Hiroyuki YASHIMA  

     
    LETTER-Coding Theory

      Pubricized:
    2021/07/14
      Vol:
    E105-A No:1
      Page(s):
    63-67

    In this letter, we study low-density parity-check (LDPC) codes for noisy channels with insertion and deletion (ID) errors. We first propose a design method of irregular LDPC codes for such channels, which can be used to simultaneously obtain degree distributions for different noise levels. We then show the asymptotic/finite-length decoding performances of designed codes and compare them with the symmetric information rates of cascaded ID-noisy channels. Moreover, we examine the relationship between decoding performance and a code structure of irregular LDPC codes.

  • Classification with CNN features and SVM on Embedded DSP Core for Colorectal Magnified NBI Endoscopic Video Image

    Masayuki ODAGAWA  Takumi OKAMOTO  Tetsushi KOIDE  Toru TAMAKI  Shigeto YOSHIDA  Hiroshi MIENO  Shinji TANAKA  

     
    PAPER-VLSI Design Technology and CAD

      Pubricized:
    2021/07/21
      Vol:
    E105-A No:1
      Page(s):
    25-34

    In this paper, we present a classification method for a Computer-Aided Diagnosis (CAD) system in a colorectal magnified Narrow Band Imaging (NBI) endoscopy. In an endoscopic video image, color shift, blurring or reflection of light occurs in a lesion area, which affects the discrimination result by a computer. Therefore, in order to identify lesions with high robustness and stable classification to these images specific to video frame, we implement a CAD system for colorectal endoscopic images with the Convolutional Neural Network (CNN) feature and Support Vector Machine (SVM) classification on the embedded DSP core. To improve the robustness of CAD system, we construct the SVM learned by multiple image sizes data sets so as to adapt to the noise peculiar to the video image. We confirmed that the proposed method achieves higher robustness, stable, and high classification accuracy in the endoscopic video image. The proposed method also can cope with differences in resolution by old and new endoscopes and perform stably with respect to the input endoscopic video image.

  • Sketch Face Recognition via Cascaded Transformation Generation Network

    Lin CAO  Xibao HUO  Yanan GUO  Kangning DU  

     
    PAPER-Image

      Pubricized:
    2021/04/01
      Vol:
    E104-A No:10
      Page(s):
    1403-1415

    Sketch face recognition refers to matching photos with sketches, which has effectively been used in various applications ranging from law enforcement agencies to digital entertainment. However, due to the large modality gap between photos and sketches, sketch face recognition remains a challenging task at present. To reduce the domain gap between the sketches and photos, this paper proposes a cascaded transformation generation network for cross-modality image generation and sketch face recognition simultaneously. The proposed cascaded transformation generation network is composed of a generation module, a cascaded feature transformation module, and a classifier module. The generation module aims to generate a high quality cross-modality image, the cascaded feature transformation module extracts high-level semantic features for generation and recognition simultaneously, the classifier module is used to complete sketch face recognition. The proposed transformation generation network is trained in an end-to-end manner, it strengthens the recognition accuracy by the generated images. The recognition performance is verified on the UoM-SGFSv2, e-PRIP, and CUFSF datasets; experimental results show that the proposed method is better than other state-of-the-art methods.

  • Design and Investigation of Silicon Gate-All-Around Junctionless Field-Effect Transistor Using a Step Thickness Gate Oxide

    Wenlun ZHANG  Baokang WANG  

     
    PAPER-Semiconductor Materials and Devices

      Pubricized:
    2021/01/15
      Vol:
    E104-C No:8
      Page(s):
    379-385

    We design a silicon gate-all-around junctionless field-effect transistor (JLFET) using a step thickness gate oxide (GOX) by the Sentaurus technology computer-aided design simulation. We demonstrate the different gate-induced drain leakage (GIDL) mechanism of the traditional inversion-mode field-effect transistor (IMFET) and JLFET. The off leakage in the IMFET is dominated by the parasitic bipolar junction transistor effect, whereas in the JLFET it is a result of the volume conduction due to the screening effect of the accumulated holes. With the introduction of a 4 nm thick-second GOX and remaining first GOX thickness of 1 nm, the tunneling generation is reduced at the channel-drain interface, leading to a decrease in the off current of the JLFET. A thicker second GOX has the total gate capacitance of JLFETs, where a 0.3 ps improved intrinsic delay is achieved. This alleviates the capacitive load of the transistor in the circuit applications. Finally, the short-channel effects of the step thickness GOX JLFET were investigated with a total gate length from 40 nm to 6 nm. The results indicate that the step thickness GOX JLFETs perform better on the on/off ratio and drain-induced barrier lowering but exhibit a small degradation on the subthreshold swing and threshold roll-off.

  • A Retrieval Method for 3D CAD Assembly Models Using 3D Radon Transform and Spherical Harmonic Transform

    Kaoru KATAYAMA  Takashi HIRASHIMA  

     
    PAPER

      Pubricized:
    2020/02/20
      Vol:
    E103-D No:5
      Page(s):
    992-1001

    We present a retrieval method for 3D CAD assemblies consisted of multiple components. The proposed method distinguishes not only shapes of 3D CAD assemblies but also layouts of their components. Similarity between two assemblies is computed from feature quantities of the components constituting the assemblies. In order to make the similarity robust to translation and rotation of an assembly in 3D space, we use the 3D Radon transform and the spherical harmonic transform. We show that this method has better retrieval precision and efficiency than targets for comparison by experimental evaluation.

  • Automatic Lung Nodule Detection in CT Images Using Convolutional Neural Networks

    Furqan SHAUKAT  Kamran JAVED  Gulistan RAJA  Junaid MIR  Muhammad Laiq Ur Rahman SHAHID  

     
    PAPER-Image

      Vol:
    E102-A No:10
      Page(s):
    1364-1373

    One of the major causes of mortalities around the globe is lung cancer with the least chance of survival even after the diagnosis. Computer-aided detection can play an important role, especially in initial screening and thus prevent the deaths caused by lung cancer. In this paper, a novel technique for lung nodule detection, which is the primary cause of lung cancer, is proposed using convolutional neural networks. Initially, the lung volume is segmented from a CT image using optimal thresholding which is followed by image enhancement using multi-scale dot enhancement filtering. Next, lung nodule candidates are detected from an enhanced image and certain features are extracted. The extracted features belong to intensity, shape and texture class. Finally, the classification of lung nodule candidates into nodules and non-nodules is done using a convolutional neural network. The Lung Image Database Consortium (LIDC) dataset has been used to evaluate the proposed system which achieved an accuracy of 94.80% with 6.2 false positives per scan only.

1-20hit(177hit)

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