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  • EfficientNet Empowered by Dendritic Learning for Diabetic Retinopathy Open Access

    Zeyuan JU  Zhipeng LIU  Yu GAO  Haotian LI  Qianhang DU  Kota YOSHIKAWA  Shangce GAO  

     
    LETTER-Artificial Intelligence, Data Mining

      Pubricized:
    2024/05/20
      Vol:
    E107-D No:9
      Page(s):
    1281-1284

    Medical imaging plays an indispensable role in precise patient diagnosis. The integration of deep learning into medical diagnostics is becoming increasingly common. However, existing deep learning models face performance and efficiency challenges, especially in resource-constrained scenarios. To overcome these challenges, we introduce a novel dendritic neural efficientnet model called DEN, inspired by the function of brain neurons, which efficiently extracts image features and enhances image classification performance. Assessments on a diabetic retinopathy fundus image dataset reveal DEN’s superior performance compared to EfficientNet and other classical neural network models.

  • Computer-Aided Design of Cross-Voltage-Domain Energy-Optimized Tapered Buffers Open Access

    Zhibo CAO  Pengfei HAN  Hongming LYU  

     
    PAPER-Electronic Circuits

      Pubricized:
    2024/04/09
      Vol:
    E107-C No:9
      Page(s):
    245-254

    This paper introduces a computer-aided low-power design method for tapered buffers that address given load capacitances, output transition times, and source impedances. Cross-voltage-domain tapered buffers involving a low-voltage domain in the frontier stages and a high-voltage domain in the posterior stages are further discussed which breaks the trade-off between the energy dissipation and the driving capability in conventional designs. As an essential circuit block, a dedicated analytical model for the level-shifter is proposed. The energy-optimized tapered buffer design is verified for different source and load conditions in a 180-nm CMOS process. The single-VDD buffer model achieves an average inaccuracy of 8.65% on the transition loss compared with Spice simulation results. Cross-voltage tapered buffers can be optimized to further remarkably reduce the energy consumption. The study finds wide applications in energy-efficient switching-mode analog applications.

  • Quantum Collision Resistance of Double-Block-Length Hashing Open Access

    Shoichi HIROSE  Hidenori KUWAKADO  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2024/03/04
      Vol:
    E107-A No:9
      Page(s):
    1478-1487

    In 2005, Nandi introduced a class of double-block-length compression functions hπ(x) := (h(x), h(π(x))), where h is a random oracle with an n-bit output and π is a non-cryptographic public permutation. Nandi demonstrated that the collision resistance of hπ is optimal if π has no fixed point in the classical setting. Our study explores the collision resistance of hπ and the Merkle-Damgård hash function using hπ in the quantum random oracle model. Firstly, we reveal that the quantum collision resistance of hπ may not be optimal even if π has no fixed point. If π is an involution, then a colliding pair of inputs can be found for hπ with only O(2n/2) queries by the Grover search. Secondly, we present a sufficient condition on π for the optimal quantum collision resistance of hπ. This condition states that any collision attack needs Ω(22n/3) queries to find a colliding pair of inputs. The proof uses the recent technique of Zhandry’s compressed oracle. Thirdly, we show that the quantum collision resistance of the Merkle-Damgård hash function using hπ can be optimal even if π is an involution. Finally, we discuss the quantum collision resistance of double-block-length compression functions using a block cipher.

  • Rectangle-of-Influence Drawings of Five-Connected Plane Graphs Open Access

    Kazuyuki MIURA  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2024/02/09
      Vol:
    E107-A No:9
      Page(s):
    1452-1457

    A rectangle-of-influence drawing of a plane graph G is a straight-line planar drawing of G such that there is no vertex in the proper inside of the axis-parallel rectangle defined by the two ends of any edge. In this paper, we show that any given 5-connected plane graph G with five or more vertices on the outer face has a rectangle-of-influence drawing in an integer grid such that W + H ≤ n - 2, where n is the number of vertices in G, W is the width and H is the height of the grid.

  • Edge Device Verification Techniques for Updated Object Detection AI via Target Object Existence Open Access

    Akira KITAYAMA  Goichi ONO  Hiroaki ITO  

     
    PAPER-Intelligent Transport System

      Pubricized:
    2023/12/20
      Vol:
    E107-A No:8
      Page(s):
    1286-1295

    Edge devices with strict safety and reliability requirements, such as autonomous driving cars, industrial robots, and drones, necessitate software verification on such devices before operation. The human cost and time required for this analysis constitute a barrier in the cycle of software development and updating. In particular, the final verification at the edge device should at least strictly confirm that the updated software is not degraded from the current it. Since the edge device does not have the correct data, it is necessary for a human to judge whether the difference between the updated software and the operating it is due to degradation or improvement. Therefore, this verification is very costly. This paper proposes a novel automated method for efficient verification on edge devices of an object detection AI, which has found practical use in various applications. In the proposed method, a target object existence detector (TOED) (a simple binary classifier) judges whether an object in the recognition target class exists in the region of a prediction difference between the AI’s operating and updated versions. Using the results of this TOED judgement and the predicted difference, an automated verification system for the updated AI was constructed. TOED was designed as a simple binary classifier with four convolutional layers, and the accuracy of object existence judgment was evaluated for the difference between the predictions of the YOLOv5 L and X models using the Cityscapes dataset. The results showed judgement with more than 99.5% accuracy and 8.6% over detection, thus indicating that a verification system adopting this method would be more efficient than simple analysis of the prediction differences.

  • New Classes of Permutation Quadrinomials Over 𝔽q3 Open Access

    Changhui CHEN  Haibin KAN  Jie PENG  Li WANG  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2023/12/27
      Vol:
    E107-A No:8
      Page(s):
    1205-1211

    Permutation polynomials have been studied for a long time and have important applications in cryptography, coding theory and combinatorial designs. In this paper, by means of the multivariate method and the resultant, we propose four new classes of permutation quadrinomials over 𝔽q3, where q is a prime power. We also show that they are not quasi-multiplicative equivalent to known ones. Moreover, we compare their differential uniformity with that of some known classes of permutation trinomials for some small q.

  • Analytical Model of Maximum Operating Frequency of Class-D ZVS Inverter with Linearized Parasitic Capacitance and any Duty Ratio Open Access

    Yi XIONG  Senanayake THILAK  Yu YONEZAWA  Jun IMAOKA  Masayoshi YAMAMOTO  

     
    PAPER-Circuit Theory

      Pubricized:
    2023/12/05
      Vol:
    E107-A No:8
      Page(s):
    1115-1126

    This paper proposes an analytical model of maximum operating frequency of class-D zero-voltage-switching (ZVS) inverter. The model includes linearized drain-source parasitic capacitance and any duty ratio. The nonlinear drain-source parasitic capacitance is equally linearized through a charge-related equation. The model expresses the relationship among frequency, shunt capacitance, duty ratio, load impedance, output current phase, and DC input voltage under the ZVS condition. The analytical result shows that the maximum operating frequency under the ZVS condition can be obtained when the duty ratio, the output current phase, and the DC input voltage are set to optimal values. A 650 V/30 A SiC-MOSFET is utilized for both simulated and experimental verification, resulting in good consistency.

  • Real-Time Safety Driving Advisory System Utilizing a Vision-Based Driving Monitoring Sensor Open Access

    Masahiro TADA  Masayuki NISHIDA  

     
    LETTER-Human-computer Interaction

      Pubricized:
    2024/03/15
      Vol:
    E107-D No:7
      Page(s):
    901-907

    In this study, we use a vision-based driving monitoring sensor to track drivers’ visual scanning behavior, a key factor for preventing traffic accidents. Our system evaluates driver’s behaviors by referencing the safety knowledge of professional driving instructors, and provides real-time voice-guided safety advice to encourage safer driving. Our system’s evaluation of safe driving behaviors matched the instructor’s evaluation with accuracy over 80%.

  • Joint CFO and DOA Estimation Based on MVDR Criterion in Interleaved OFDMA/SDMA Uplink Open Access

    Chih-Chang SHEN  Wei JHANG  

     
    LETTER-Spread Spectrum Technologies and Applications

      Pubricized:
    2023/10/26
      Vol:
    E107-A No:7
      Page(s):
    1066-1070

    This letter deals with joint carrier frequency offset (CFO) and direction of arrival (DOA) estimation based on the minimum variance distortionless response (MVDR) criterion for interleaved orthogonal frequency division multiple access (OFDMA)/space division multiple access (SDMA) uplink systems. In order to reduce the computational load of two-dimensional searching based methods, the proposed method includes only once polynomial CFO rooting and does not require DOA paring, hence it raises the searching efficiency. Several simulation results are provided to illustrate the effectiveness of the proposed method.

  • A Sequential Approach to Detect Drifts and Retrain Neural Networks on Resource-Limited Edge Devices Open Access

    Kazuki SUNAGA  Takeya YAMADA  Hiroki MATSUTANI  

     
    PAPER-Software System

      Pubricized:
    2024/02/09
      Vol:
    E107-D No:6
      Page(s):
    741-750

    A practical issue of edge AI systems is that data distributions of trained dataset and deployed environment may differ due to noise and environmental changes over time. Such a phenomenon is known as a concept drift, and this gap degrades the performance of edge AI systems and may introduce system failures. To address this gap, retraining of neural network models triggered by concept drift detection is a practical approach. However, since available compute resources are strictly limited in edge devices, in this paper we propose a fully sequential concept drift detection method in cooperation with an on-device sequential learning technique of neural networks. In this case, both the neural network retraining and the proposed concept drift detection are done only by sequential computation to reduce computation cost and memory utilization. We use three datasets for experiments and compare the proposed approach with existing batch-based detection methods. It is also compared with a DNN-based approach without concept drift detection. The evaluation results of the proposed approach show that the proposed method is capable of detecting each of four concept drift types. The results also show that, while the accuracy is decreased by up to 0.9% compared to the existing batch-based detection methods, it decreases the memory size by 88.9%-96.4% and the execution time by 45.0%-87.6%. As a result, the combination of the neural network retraining and the proposed concept drift detection method is demonstrated on Raspberry Pi Pico that has 264 kB memory.

  • Deeply Programmable Application Switch for Performance Improvement of KVS in Data Center Open Access

    Satoshi ITO  Tomoaki KANAYA  Akihiro NAKAO  Masato OGUCHI  Saneyasu YAMAGUCHI  

     
    PAPER

      Pubricized:
    2024/01/17
      Vol:
    E107-D No:5
      Page(s):
    659-673

    The concepts of programmable switches and software-defined networking (SDN) give developers flexible and deep control over the behavior of switches. We expect these concepts to dramatically improve the functionality of switches. In this paper, we focus on the concept of Deeply Programmable Networks (DPN), where data planes are programmable, and application switches based on DPN. We then propose a method to improve the performance of a key-value store (KVS) through an application switch. First, we explain the DPN and application switches. The DPN is a network that makes not only control planes but also data planes programmable. An application switch is a switch that implements some functions of network applications, such as database management system (DBMS). Second, we propose a method to improve the performance of Cassandra, one of the most popular key-value based DBMS, by implementing a caching function in a switch in a dedicated network such as a data center. The proposed method is expected to be effective even though it is a simple and traditional way because it is in the data path and the center of the network application. Third, we implement a switch with the caching function, which monitors the accessed data described in packets (Ethernet frames) and dynamically replaces the cached data in the switch, and then show that the proposed caching switch can significantly improve the KVS transaction performance with this implementation. In the case of our evaluation, our method improved the KVS transaction throughput by up to 47%.

  • Effects of Electromagnet Interference on Speed and Position Estimations of Sensorless SPMSM Open Access

    Yuanhe XUE  Wei YAN  Xuan LIU  Mengxia ZHOU  Yang ZHAO  Hao MA  

     
    PAPER-Electromechanical Devices and Components

      Pubricized:
    2023/11/10
      Vol:
    E107-C No:5
      Page(s):
    124-131

    Model-based sensorless control of permanent magnet synchronous motor (PMSM) is promising for high-speed operation to estimate motor state, which is the speed and the position of the rotor, via electric signals of the stator, beside the inevitable fact that estimation accuracy is degraded by electromagnet interference (EMI) from switching devices of the converter. In this paper, the simulation system based on Luenberger observer and phase-locked loop (PLL) has been established, analyzing impacts of EMI on motor state estimations theoretically, exploring influences of EMI with different cutoff frequency, rated speeds, frequencies and amplitudes. The results show that Luenberger observer and PLL have strong immunity, which enable PMSM can still operate stably even under certain degrees of interference. EMI produces sideband harmonics that enlarge pulsation errors of speed and position estimations. Additionally, estimation errors are positively correlated with cutoff frequency of low-pass filter and the amplitude of EMI, and negatively correlated with rated speed of the motor and the frequency of EMI.  When the frequency is too high, its effects on motor state estimations are negligible. This work contributes to the comprehensive understanding of how EMI affects motor state estimations, which further enhances practical application of sensorless PMSM.

  • Estimation of Drone Payloads Using Millimeter-Wave Fast-Chirp-Modulation MIMO Radar Open Access

    Kenshi OGAWA  Masashi KUROSAKI  Ryohei NAKAMURA  

     
    PAPER-Sensing

      Vol:
    E107-B No:5
      Page(s):
    419-428

    With the development of drone technology, concerns have arisen about the possibility of drones being equipped with threat payloads for terrorism and other crimes. A drone detection system that can detect drones carrying payloads is needed. A drone’s propeller rotation frequency increases with payload weight. Therefore, a method for estimating propeller rotation frequency will effectively detect the presence or absence of a payload and its weight. In this paper, we propose a method for classifying the payload weight of a drone by estimating its propeller rotation frequency from radar images obtained using a millimeter-wave fast-chirp-modulation multiple-input and multiple-output (MIMO) radar. For each drone model, the proposed method requires a pre-prepared reference dataset that establishes the relationships between the payload weight and propeller rotation frequency. Two experimental measurement cases were conducted to investigate the effectiveness of our proposal. In case 1, we assessed four drones (DJI Matrice 600, DJI Phantom 3, DJI Mavic Pro, and DJI Mavic Mini) to determine whether the propeller rotation frequency of any drone could be correctly estimated. In case 2, experiments were conducted on a hovering Phantom 3 drone with several payloads in a stable position for calculating the accuracy of the payload weight classification. The experimental results indicated that the proposed method could estimate the propeller rotation frequency of any drone and classify payloads in a 250 g step with high accuracy.

  • A Small-Data Solution to Data-Driven Lyapunov Equations: Data Reduction from O(n2) to O(n) Open Access

    Keitaro TSUJI  Shun-ichi AZUMA  Ikumi BANNO  Ryo ARIIZUMI  Toru ASAI  Jun-ichi IMURA  

     
    PAPER

      Pubricized:
    2023/10/24
      Vol:
    E107-A No:5
      Page(s):
    806-812

    When a mathematical model is not available for a dynamical system, it is reasonable to use a data-driven approach for analysis and control of the system. With this motivation, the authors have recently developed a data-driven solution to Lyapunov equations, which uses not the model but the data of several state trajectories of the system. However, the number of state trajectories to uniquely determine the solution is O(n2) for the dimension n of the system. This prevents us from applying the method to a case with a large n. Thus, this paper proposes a novel class of data-driven Lyapunov equations, which requires a smaller amount of data. Although the previous method constructs one scalar equation from one state trajectory, the proposed method constructs three scalar equations from any combination of two state trajectories. Based on this idea, we derive data-driven Lyapunov equations such that the number of state trajectories to uniquely determine the solution is O(n).

  • A Mueller-Müller CDR with False-Lock-Aware Locking Scheme for a 56-Gb/s ADC-Based PAM4 Transceiver Open Access

    Fumihiko TACHIBANA  Huy CU NGO  Go URAKAWA  Takashi TOI  Mitsuyuki ASHIDA  Yuta TSUBOUCHI  Mai NOZAWA  Junji WADATSUMI  Hiroyuki KOBAYASHI  Jun DEGUCHI  

     
    PAPER

      Pubricized:
    2023/11/02
      Vol:
    E107-A No:5
      Page(s):
    709-718

    Although baud-rate clock and data recovery (CDR) such as Mueller-Müller (MM) CDR is adopted to ADC-based receivers (RXs), it suffers from false-lock points when the RXs handle PAM4 data pattern because of the absence of edge data. In this paper, a false-lock-aware locking scheme is proposed to address this issue. After the false-lock-aware locking scheme, a clock phase is adjusted to achieve maximum eye height by using a post-1-tap parameter for an FFE in the CDR loop. The proposed techniques are implemented in a 56-Gb/s PAM4 transceiver. A PLL uses an area-efficient “glasses-shaped” inductor. The RX comprises an AFE, a 28-GS/s 7-bit time-interleaved SAR ADC, and a DSP with a 31-tap FFE and a 1-tap DFE. A TX is based on a 7-bit DAC with a 4-tap FFE. The transceiver is fabricated in 16-nm CMOS FinFET technology, and achieves a BER of less than 1e-7 with a 30-dB loss channel. The measurement results show that the MM CDR escapes from false-lock points, and converges to near the optimum point for large eye height.

  • Input Data Format for Sparse Matrix in Quantum Annealing Emulator

    Sohei SHIMOMAI  Kei UEDA  Shinji KIMURA  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2023/09/25
      Vol:
    E107-A No:3
      Page(s):
    557-565

    Recently, Quantum Annealing (QA) has attracted attention as an efficient algorithm for combinatorial optimization problems. In QA, the input data size becomes large and its reduction is important for accelerating by the hardware emulation since the usable memory size and its bandwidth are limited. The paper proposes the compression method of input sparse matrices for QA emulator. The proposed method uses the sparseness of the coefficient matrix and the reappearance of the same values. An independent table is introduced and data are compressed by the search and registration method of two consecutive data in the value table. The proposed method is applied to Traveling Salesman Problem (TSP) with 32, 64 and 96 cities and Nurse Scheduling Problem (NSP). The proposed method could reduce the amount of data by 1/40 for 96 city TSP and could manage 96 city TSP on the hardware emulator. When applied to NSP, we confirmed the effectiveness of the proposed method by the compression ratio ranging from 1/4 to 1/11.8. The data reduction is also useful for the simulation/emulation performance when using the compressed data directly and 1.9 times faster speed can be found on 96 city TSP than the CSR-based method.

  • Pipelined ADPCM Compression for HDR Synthesis on an FPGA

    Masahiro NISHIMURA  Taito MANABE  Yuichiro SHIBATA  

     
    PAPER-VLSI Design Technology and CAD

      Pubricized:
    2023/08/31
      Vol:
    E107-A No:3
      Page(s):
    531-539

    This paper presents an FPGA implementation of real-time high dynamic range (HDR) synthesis, which expresses a wide dynamic range by combining multiple images with different exposures using image pyramids. We have implemented a pipeline that performs streaming processing on images without using external memory. However, implementation for high-resolution images has been difficult due to large memory usage for line buffers. Therefore, we propose an image compression algorithm based on adaptive differential pulse code modulation (ADPCM). Compression modules based on the algorithm can be easily integrated into the pipeline. When the image resolution is 4K and the pyramid depth is 7, memory usage can be halved from 168.48% to 84.32% by introducing the compression modules, resulting in better quality.

  • Development of a Coanda-Drone with Built-in Propellers

    Zejing ZHAO  Bin ZHANG  Hun-ok LIM  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2023/11/10
      Vol:
    E107-D No:2
      Page(s):
    180-190

    In this study, a Coanda-drone with length, width, and height of 121.6, 121.6, and 191[mm] was designed, and its total mass was 1166.7[g]. Using four propulsion devices, it could produce a maximum of 5428[g] thrust. Its structure is very different from conventional drones because in this study it combines the design of the jet engine of a jet fixed-wing drone with the fuselage structure layout of a rotary-wing drone. The advantage of jet drone's high propulsion is kept so that it can output greater thrust under the same variation of PWM waveform output. In this study, the propulsion device performs high-speed jetting, and the airflow around the propulsion device will also be jetted downward along the direction of the airflow.

  • Pseudorandom Binary Sequences: Quality Measures and Number-Theoretic Constructions

    Arne WINTERHOF  

     
    INVITED PAPER-Cryptography and Information Security

      Pubricized:
    2023/05/31
      Vol:
    E106-A No:12
      Page(s):
    1452-1460

    In this survey we summarize properties of pseudorandomness and non-randomness of some number-theoretic sequences and present results on their behaviour under the following measures of pseudorandomness: balance, linear complexity, correlation measure of order k, expansion complexity and 2-adic complexity. The number-theoretic sequences are the Legendre sequence and the two-prime generator, the Thue-Morse sequence and its sub-sequence along squares, and the prime omega sequences for integers and polynomials.

  • A Unified Software and Hardware Platform for Machine Learning Aided Wireless Systems

    Dody ICHWANA PUTRA  Muhammad HARRY BINTANG PRATAMA  Ryotaro ISSHIKI  Yuhei NAGAO  Leonardo LANANTE JR  Hiroshi OCHI  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2023/08/22
      Vol:
    E106-A No:12
      Page(s):
    1493-1503

    This paper presents a unified software and hardware wireless AI platform (USHWAP) for developing and evaluating machine learning in wireless systems. The platform integrates multi-software development such as MATLAB and Python with hardware platforms like FPGA and SDR, allowing for flexible and scalable device and edge computing application development. The USHWAP is implemented and validated using FPGAs and SDRs. Wireless signal classification, wireless LAN sensing, and rate adaptation are used as examples to showcase the platform's capabilities. The platform enables versatile development, including software simulation and real-time hardware implementation, offering flexibility and scalability for multiple applications. It is intended to be used by wireless-AI researchers to develop and evaluate intelligent algorithms in a laboratory environment.

1-20hit(1315hit)