IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
Online ISSN : 1745-1337
Print ISSN : 0916-8508
最新号
選択された号の論文の37件中1~37を表示しています
Special Section on Intelligent Transport Systems
  • Tomotaka WADA
    2021 年 E104.A 巻 2 号 p. 348
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル フリー
  • Koji OGURI, Haruki KAWANAKA, Shintaro ONO
    原稿種別: INVITED PAPER
    2021 年 E104.A 巻 2 号 p. 349-356
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル フリー

    The environment surrounding automotive technology is undergoing a major transformation. In particular, as technological innovation advances in new areas called “CASE” such as Connected, Autonomous/Automated, Shared, and Electric, various research activities are underway. However, this is an approach from the standpoint of the automobile centered, and when considering the development of a new automobile society, it is necessary to consider from the standpoint of “human centered,” who are users, too. Therefore, this paper proposes the possibility of technological innovation in the area of “Another CASE” such as Comfortable, Accessible, Safety, and Enjoy/Exciting, and introduces the contents of some interesting researches.

  • Go ISHII, Takaaki HASEGAWA, Daichi CHONO
    原稿種別: PAPER
    2021 年 E104.A 巻 2 号 p. 357-365
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    In this paper, we build a microscopic simulator of traffic flow in a three-modal transport society for pedestrians/slow vehicles/vehicles (P/SV/V) to evaluate a post P/V society. The simulator assumes that the SV includes bicycles and micro electric vehicles, whose speed is strictly and mechanically limited up to 30 km/h. In addition, this simulator adopts an SV overtaking model. Modal shifts caused by modal diversity requires new valuation indexes. The simulator has a significant feature of a traveler-based traffic demand simulation not a vehicle-based traffic demand simulation as well as new evaluation indexes. New assessment taking this situation into account is conducted and the results explain new aspects of traffic flow in a three-mode transport society.

  • Taichi NAWANO, Tetsuya MANABE
    原稿種別: LETTER
    2021 年 E104.A 巻 2 号 p. 366-370
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    This paper proposes a route calculation method for a bicycle navigation system that complies with traffic regulations. The extension of the node map and three kinds of route calculation methods are constructed and evaluated on the basis of travel times and system acceptability survey results. Our findings reveal the effectiveness of the proposed route calculation method and the acceptability of the bicycle navigation system that included the method.

  • Kosuke OMURA, Tetsuya MANABE
    原稿種別: LETTER
    2021 年 E104.A 巻 2 号 p. 371-374
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    In this paper, we clarify the importance of performance evaluation using a plurality of smartphones in a positioning system based on radio waves. Specifically, in a positioning system using bluetooth low energy, the positioning performance of two types of positioning algorithms is performed using a plurality of smartphones. As a result, we confirmed that the fingerprint algorithm does not always provide sufficient positioning performance. It depends on the model of the smartphone used. On the other hand, the hybrid algorithm that the authors have already proposed is robust in the difference of the received signal characteristics of the smartphone. Consequently, we spotlighted that the use of multiple devices is essential for providing high-quality location-based services in real environments in the performance evaluation of radio wave-based positioning systems using smartphones.

Special Section on Signal Design and Its Applications in Communications
  • Pingzhi FAN, Tetsuya KOJIMA
    2021 年 E104.A 巻 2 号 p. 375
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル フリー
  • Fang LIU, Kenneth W. SHUM, Yijin ZHANG, Wing Shing WONG
    原稿種別: INVITED PAPER
    専門分野: Communication Theory and Signals
    2021 年 E104.A 巻 2 号 p. 376-383
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    We consider all-to-all broadcast and unicast among nodes in a multi-channel single-hop ad hoc network, with no time synchronization. Motivated by the hard delay requirement for ultra-reliable and low-latency communication (URLLC) in 5G wireless networks, we aim at designing medium access control (MAC) schemes to guarantee successful node-to-node transmission within a bounded delay. To provide a hard guarantee on the transmission delay, deterministic sequence schemes are preferred to probabilistic schemes such as carrier sense multiple access (CSMA). Therefore, we mainly consider sequence schemes, with the goal to design schedule sequence set to guarantee successful broadcast/unicast within a common sequence period. This period should be as short as possible since it determines an upper bound on the transmission delay. In previous works, we have considered sequence design under time division duplex (TDD). In this paper, we focus on another common duplex mode, frequency division duplex (FDD). For the FDD case, we present a lower bound on period of feasible sequence sets, and propose a sequence construction method by which the sequence period can achieve the same order as the lower bound, for both broadcast and unicast models. We also compare the sequence length for FDD with that for TDD.

  • Mingxing ZHANG, Zhengchun ZHOU, Meng YANG, Haode YAN
    原稿種別: PAPER
    専門分野: Communication Theory and Signals
    2021 年 E104.A 巻 2 号 p. 384-391
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    The partial-period autocorrelation of sequences is an important performance measure of communication systems employing them, but it is notoriously difficult to be analyzed. In this paper, we propose an algorithm to design unimodular sequences with low partial-period autocorrelations via directly minimizing the partial-period integrated sidelobe level (PISL). The proposed algorithm is inspired by the monotonic minimizer for integrated sidelobe level (MISL) algorithm. Then an acceleration scheme is considered to further accelerate the algorithms. Numerical experiments show that the proposed algorithm can effectively generate sequences with lower partial-period peak sidelobe level (PPSL) compared with the well-known Zadoff-Chu sequences.

  • Bing LIU, Zhengchun ZHOU, Udaya PARAMPALLI
    原稿種別: PAPER
    専門分野: Communication Theory and Signals
    2021 年 E104.A 巻 2 号 p. 392-398
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    Inspired by an idea due to Levenshtein, we apply the low correlation zone constraint in the analysis of the weighted mean square aperiodic correlation. Then we derive a lower bound on the measure for quasi-complementary sequence sets with low correlation zone (LCZ-QCSS). We discuss the conditions of tightness for the proposed bound. It turns out that the proposed bound is tighter than Liu-Guan-Ng-Chen bound for LCZ-QCSS. We also derive a lower bound for QCSS, which improves the Liu-Guan-Mow bound in general.

  • Xina ZHANG, Xiaoni DU, Rong WANG, Fujun ZHANG
    原稿種別: PAPER
    専門分野: Coding Theory
    2021 年 E104.A 巻 2 号 p. 399-403
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    Linear codes with a few weights have many applications in secret sharing schemes, authentication codes, association schemes and strongly regular graphs, and they are also of importance in consumer electronics, communications and data storage systems. In this paper, based on the theory of defining sets, we present a class of five-weight linear codes over $\mathbb{F}_p$(p is an odd prime), which include an almost optimal code with respect to the Griesmer bound. Then, we use exponential sums to determine the weight distribution.

  • Kosuke SHIMA, Kazuki MARUTA, Chang-Jun AHN
    原稿種別: PAPER
    専門分野: Digital Signal Processing
    2021 年 E104.A 巻 2 号 p. 404-411
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    This paper proposes a novel weight derivation method to improve adaptive array interference suppression performance based on our previously conceived sample matrix inversion algorithm using common correlation matrix (CCM-SMI), by data-aided approach. In recent broadband wireless communication system such as orthogonal frequency division multiplexing (OFDM) which possesses lots of subcarriers, the computation complexity is serious problem when using SMI algorithm to suppress unknown interference. To resolve this problem, CCM based SMI algorithm was previously proposed. It computes the correlation matrix by the received time domain signals before fast Fourier transform (FFT). However, due to the limited number of pilot symbols, the estimated channel state information (CSI) is often incorrect. It leads limited interference suppression performance. In this paper, we newly employ a data-aided channel state estimation. Decision results of received symbols are obtained by CCM-SMI and then fed-back to the channel estimator. It assists improving CSI estimation accuracy. Computer simulation result reveals that our proposal accomplishes better bit error rate (BER) performance in spite of the minimum pilot symbols with a slight additional computation complexity.

  • Zhi GU, Yong WANG, Yang YANG
    原稿種別: LETTER
    専門分野: Coding Theory
    2021 年 E104.A 巻 2 号 p. 412-416
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル フリー

    This paper is focused on constructing even-length binary Z-complementary pairs (EB-ZCPs) with new length. Inspired by a recent work of Adhikary et al., we give a construction of EB-ZCPs with length 8N+4 (where N=2α 10β 26γ and α, β, γ are nonnegative integers) and zero correlation zone (ZCZ) width 5N+2. The maximum aperiodic autocorrelation sums (AACS) magnitude of the proposed sequences outside the ZCZ region is 8. It turns out that the generated sequences have low PAPR.

  • Takahiro MATSUMOTO, Hideyuki TORII, Yuta IDA, Shinya MATSUFUJI
    原稿種別: LETTER
    専門分野: Spread Spectrum Technologies and Applications
    2021 年 E104.A 巻 2 号 p. 417-421
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    In this paper, we propose new generation methods of two-dimensional (2D) optical zero-correlation zone (ZCZ) sequences with the high peak autocorrelation amplitude. The 2D optical ZCZ sequence consists of a pair of a binary sequence which takes 1 or 0 and a bi-phase sequence which takes 1 or -1, and has a zero-correlation zone in the two-dimensional correlation function. Because of these properties, the 2D optical ZCZ sequence is suitable for optical code-division multiple access (OCDMA) system using an LED array having a plurality of light-emitting elements arranged in a lattice pattern. The OCDMA system using the 2D optical ZCZ sequence can be increased the data rate and can be suppressed interference by the light of adjacent LEDs. By using the proposed generation methods, we can improve the peak autocorrelation amplitude of the sequence. This means that the BER performance of the OCDMA system using the sequence can be improved.

Special Section on Mathematical Systems Science and its Applications
Special Section on Analog Circuit Techniques and Related Topics
  • Nobuyuki ITOH
    2021 年 E104.A 巻 2 号 p. 476
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル フリー
  • Toshihiko YOSHIMASU, Mengchu FANG, Tsuyoshi SUGIURA
    原稿種別: INVITED PAPER
    2021 年 E104.A 巻 2 号 p. 477-483
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    This paper presents a 26-GHz-band high back-off efficiency power amplifier (PA) IC with adaptively controlled bias and load circuits in 45-nm CMOS SOI. A 4-stacked-FET is employed to increase the output power and to conquer the low breakdown voltage issue of scaled MOSFET. The adaptive bias circuit is reviewed and the adaptive load circuit which consists of an inverter circuit and transformer-based inductors is described in detail. The measured performance of the PA IC is fully shown in this paper. The PA IC exhibits a saturated output power of 20.5dBm and a peak power-added-efficiency (PAE) as high as 39.4% at a supply voltage of 4.0V. Moreover, the PA IC has exhibited an excellent ITRS FoM of 82.0dB.

  • Satoshi TANAKA
    原稿種別: PAPER
    2021 年 E104.A 巻 2 号 p. 484-491
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    Since 2020, the service of the 5th generation (5G) mobile phone has been started. In order to increase the transmission speed in 5G mobile phones, the multi-level of the modulated signal is advanced, and for that, the power amplifier (PA) high linearity is required even at low output power. In accordance with this, the review of the linearization technology of a PA has become important. As a performance index of the distortion of the PA, the output power dependence of the gain and phase, the AM (Amplitude Modulation)-AM/PM (Phase Modulation) characteristic is well known. There has been a lot of consideration for the AM-AM/PM characteristics of PA. The AM-AM/PM characteristics are affected by both source and load impedances. In this paper, a single-stage HBT (Hetero-junction Bipolar Transistor) PA is described by a simple linear equivalent circuit with multiple parameter sets. Each parameter set is defined according to the PA output power level. With this simple model, we investigated the change of AM-AM/PM characteristics when the reactance parts of source and load impedances was changed. It has become clear that change in the AM-AM/PM characteristics of the PA when the parameters were changed was mainly due to the change in the AM-AM/PM characteristics at the base node.

  • Yohei NAKAMURA, Shinya KAJIYAMA, Yutaka IGARASHI, Takashi OSHIMA, Taiz ...
    原稿種別: PAPER
    2021 年 E104.A 巻 2 号 p. 492-498
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル フリー

    3D ultrasound imagers require low-noise amplifier (LNA) with much lower power consumption and smaller chip area than conventional 2D imagers because of the huge amount of transducer channels. This paper presents a low-power small-size LNA with a novel current-reuse circuitry for 3D ultrasound imaging systems. The proposed LNA is composed of a differential common source amplifier and a source-follower driver which share the current without using inductors. The LNA was fabricated in a 0.18-μm CMOS process with only 0.0056mm2. The measured results show a gain of 21dB and a bandwidth of 9MHz. The proposed LNA achieves an average noise density of 11.3nV/√Hz, and the 2nd harmonic distortion below -40dBc with 0.1-Vpp input. The supply current is 85μA with a 1.8-V power supply, which is competitive with conventional LNAs by finer CMOS process.

  • Guoqiang ZHANG, Lingjin CAO, Kosuke YAYAMA, Akio KATSUSHIMA, Takahiro ...
    原稿種別: PAPER
    2021 年 E104.A 巻 2 号 p. 499-505
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    A differential on chip oscillator (OCO) is proposed in this paper for low supply voltage, high frequency accuracy and fast startup. The differential architecture helps the OCO achieve a good power supply rejection ratio (PSRR) without using a regulator so as to make the OCO suitable for a low power supply voltage of 1.38V. A reference voltage generator is also developed to generate two output voltages lower than Vbe for low supply voltage operation. The output frequency is locked to 48MHz by a frequency-locked loop (FLL) and a 3.3-ppm/°C temperature coefficient of frequency is realized by the differential voltage ratio adjusting (differential VRA) technique. The startup time is only 1.47μs because the differential OCO is not necessary to charge a big capacitor for ripple reduction.

  • Minoru SUDO, Fumiyasu UTSUNOMIYA, Ami TANAKA, Takakuni DOUSEKI
    原稿種別: PAPER
    2021 年 E104.A 巻 2 号 p. 506-515
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    A temperature-variation-tolerant intermittent startup circuit (ISC) that suppresses quiescent current to 300nA at 0.48V was developed. The ISC is a key circuit for a batteryless wireless sensor that can detect a 1μA generation current of energy harvesting sources from the intervals of wireless signals. The ISC consists of an ultralow-voltage detector composed of a depletion-type MOSFET and low-Vth MOSFETs, a Dickson-type gate-boosted charge pump circuit, and a power-switch control circuit. The detector consists of a voltage reference comparator and a feedback-controlled latch circuit for a hysteresis function. The voltage reference comparator, which has a common source stage with a folded constant-current-source load composed of a depletion-type nMOSFET, makes it possible to reduce the temperature dependency of the detection voltage, while suppressing the quiescent current to 300nA at 0.48V. The ISC fabricated with fully-depleted silicon-on-insulator (FD-SOI) CMOS technology also suppresses the variation of the quiescent current. To verify the effectiveness of the circuit, the ISC was fabricated in a 0.8-μm triple-Vth FD-SOI CMOS process. An experiment on the fabricated system, the ISC boosts the input voltage of 0.48V to 2.4V while suppressing the quiescent current to less than 300nA at 0.48V. The measured temperature coefficient of the detection voltage was ±50ppm/°C. The fluctuation of the quiescent current was 250nA ± 90nA in the temperature range from 0°C to 40°C. An intermittent energy harvesting sensor with the ISC was also fabricated. The sensor could detect a generation current of 1μA at EH sources within an accuracy of ±15% in the temperature range from 0°C to 40°C. It was also successfully applied to a self-powered wireless plant-monitoring sensor system.

  • Satoshi SEKINE, Tatsuji MATSUURA, Ryo KISHIDA, Akira HYOGO
    原稿種別: PAPER
    2021 年 E104.A 巻 2 号 p. 516-524
    発行日: 2021/02/01
    公開日: 2021/02/01
    ジャーナル 認証あり

    C-C successive approximation register analog-to-digital converter (C-C SAR-ADC) is space-saving architecture compared to SAR-ADC with binary weighted capacitive digital-to-analog converter (CDAC). However, the accuracy of C-C SAR-ADC is degraded due to parasitic capacitance of floating nodes. This paper proposes an algorithm calibrating the non-linearity by γ-estimation to accurately estimate radix greater than 2 required to realize C-C SAR-ADC. Behavioral analyses show that the radix γ-estimation error become within 1.5, 0.4 and 0.1% in case of 8-, 10- and 12-bit resolution ADC, respectively. SPICE simulations show that the γ-estimation satisfies the requirement of 10-bit resolution C-C SAR-ADC. The C-C SAR-ADC using γ-estimation achieves 9.72bit of ENOB, 0.8/-0.5LSB and 0.5/-0.4LSB of DNL/INL.

Regular Section
  • Ryutaro FUJIKAWA, Tomoyuki TOGAWA, Toshimichi SAITO
    原稿種別: PAPER
    専門分野: Nonlinear Problems
    2021 年 E104.A 巻 2 号 p. 525-531
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/06
    ジャーナル 認証あり

    This paper studies a novel approach to analysis of switched dynamical systems in perspective of bifurcation and multiobjective optimization. As a first step, we analyze a simple switched dynamical system based on a boost converter with photovoltaic input. First, in a bifurcation phenomenon perspective, we consider period doubling bifurcation sets in the parameter space. Second, in a multiobjective optimization perspective, we consider a trade-off between maximum input power and stability. The trade-off is represented by a Pareto front in the objective space. Performing numerical experiments, relationship between the bifurcation sets and the Pareto front is investigated.

  • Zhenhui XU, Tielong SHEN, Daizhan CHENG
    原稿種別: PAPER
    専門分野: Numerical Analysis and Optimization
    2021 年 E104.A 巻 2 号 p. 532-541
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/18
    ジャーナル 認証あり

    This paper studies the infinite time horizon optimal control problem for continuous-time nonlinear systems. A completely model-free approximate optimal control design method is proposed, which only makes use of the real-time measured data from trajectories instead of a dynamical model of the system. This approach is based on the actor-critic structure, where the weights of the critic neural network and the actor neural network are updated sequentially by the method of weighted residuals. It should be noted that an external input is introduced to replace the input-to-state dynamics to improve the control policy. Moreover, strict proof of convergence to the optimal solution along with the stability of the closed-loop system is given. Finally, a numerical example is given to show the efficiency of the method.

  • Rui YIN, Zhiqun ZOU, Celimuge WU, Jiantao YUAN, Xianfu CHEN, Guanding ...
    原稿種別: PAPER
    専門分野: Mobile Information Network and Personal Communications
    2021 年 E104.A 巻 2 号 p. 542-549
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/20
    ジャーナル 認証あり

    The unlicensed spectrum has been utilized to make up the shortage on frequency spectrum in new radio (NR) systems. To fully exploit the advantages brought by the unlicensed bands, one of the key issues is to guarantee the fair coexistence with WiFi systems. To reach this goal, timely and accurate estimation on the WiFi traffic loads is an important prerequisite. In this paper, a machine learning (ML) based method is proposed to detect the number of WiFi users on the unlicensed bands. An unsupervised Neural Network (NN) structure is applied to filter the detected transmission collision probability on the unlicensed spectrum, which enables the NR users to precisely rectify the measurement error and estimate the number of active WiFi users. Moreover, NN is trained online and the related parameters and learning rate of NN are jointly optimized to estimate the number of WiFi users adaptively with high accuracy. Simulation results demonstrate that compared with the conventional Kalman Filter based detection mechanism, the proposed approach has lower complexity and can achieve a more stable and accurate estimation.

  • Yuji ARAKI, Kentaro MITA, Koichi ICHIGE
    原稿種別: PAPER
    専門分野: Image
    2021 年 E104.A 巻 2 号 p. 550-562
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/06
    ジャーナル 認証あり

    We propose an iterative single-image haze-removal method that first divides images with haze into regions in which haze-removal processing is difficult and then estimates the ambient light. The existing method has a problem wherein it often overestimates the amount of haze in regions where there is a large distance between the location the photograph was taken and the subject of the photograph; this problem prevents the ambient light from being estimated accurately. In particular, it is often difficult to accurately estimate the ambient light of images containing white and sky regions. Processing those regions in the same way as other regions has detrimental results, such as darkness or unnecessary color change. The proposed method divides such regions in advance into multiple small regions, and then, the ambient light is estimated from the small regions in which haze removal is easy to process. We evaluated the proposed method through some simulations, and found that the method achieves better haze reduction accuracy even than the state-of-the art methods based on deep learning.

  • Yuxuan ZHU, Yong PENG, Yang SONG, Kenji OZAWA, Wanzeng KONG
    原稿種別: PAPER
    専門分野: Biometrics
    2021 年 E104.A 巻 2 号 p. 563-571
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/06
    ジャーナル 認証あり

    In this study we propose a method to perform personal identification (PI) based on Electroencephalogram (EEG) signals, where the used network is named residual and multiscale spatio-temporal convolution neural network (RAMST-CNN). Combined with some popular techniques in deep learning, including residual learning (RL), multi-scale grouping convolution (MGC), global average pooling (GAP) and batch normalization (BN), RAMST-CNN has powerful spatio-temporal feature extraction ability as it achieves task-independence that avoids the complexity of selecting and extracting features manually. Experiments were carried out on multiple datasets, the results of which were compared with methods from other studies. The results show that the proposed method has a higher recognition accuracy even though the network it is based on is lightweight.

  • Yue MA, Chen MIAO, Yuehua LI, Wen WU
    原稿種別: LETTER
    専門分野: Digital Signal Processing
    2021 年 E104.A 巻 2 号 p. 572-575
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/06
    ジャーナル 認証あり

    This letter proposes the use of a novel time-modulated array structure to estimate the direction of arrival (DOA). Such a time-modulated coprime array (TMCA) is obtained by exchanging a coprime array's phase shifter for a radio frequency (RF) switch. Compared with a traditional coprime array, the TMCA's structure is much simpler, and it has a higher degree of freedom and resolution compared with a time-modulated uniform linear array (TMULA) due to its exploitation of the virtual array's equivalent signals. Theoretical analysis and experimental results have validated the effectiveness of the proposed structure and method and have confirmed that a TMCA's DOA performance is better than that of a TMULA using the same number of antennas.

  • Liang ZHU, Youguo WANG, Jian LIU
    原稿種別: LETTER
    専門分野: Graphs and Networks
    2021 年 E104.A 巻 2 号 p. 576-581
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/20
    ジャーナル 認証あり

    Identifying the infection sources in a network, including the sponsor of a network rumor, the servers that inject computer virus into a computer network, or the zero-patient in an infectious disease network, plays a critical role in limiting the damage caused by the infection. A two-source estimator is firstly constructed on basis of partitions of infection regions in this paper. Meanwhile, the two-source estimation problem is transformed into calculating the expectation of permitted permutations count which can be simplified to a single-source estimation problem under determined infection region. A heuristic algorithm is also proposed to promote the estimator to general graphs in a Breadth-First-Search (BFS) fashion. Experimental results are provided to verify the performance of our method and illustrate variations of error detection in different networks.

  • Hedong HOU, Haiyang LIU, Lianrong MA
    原稿種別: LETTER
    専門分野: Coding Theory
    2021 年 E104.A 巻 2 号 p. 582-586
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/06
    ジャーナル 認証あり

    In this letter, we consider the incorrigible sets of binary linear codes. First, we show that the incorrigible set enumerator of a binary linear code is tantamount to the Tutte polynomial of the vector matroid induced by the parity-check matrix of the code. A direct consequence is that determining the incorrigible set enumerator of binary linear codes is #P-hard. Then for a cycle code, we express its incorrigible set enumerator via the Tutte polynomial of the graph describing the code. Furthermore, we provide the explicit formula of incorrigible set enumerators of cycle codes constructed from complete graphs.

  • Wentao LYU, Qiqi LIN, Lipeng GUO, Chengqun WANG, Zhenyi YANG, Weiqiang ...
    原稿種別: LETTER
    専門分野: Image
    2021 年 E104.A 巻 2 号 p. 587-590
    発行日: 2021/02/01
    公開日: 2021/02/01
    [早期公開] 公開日: 2020/08/18
    ジャーナル 認証あり

    In this paper, we present a novel method for vehicle detection based on the Faster R-CNN frame. We integrate MobileNet into Faster R-CNN structure. First, the MobileNet is used as the base network to generate the feature map. In order to retain the more information of vehicle objects, a fusion strategy is applied to multi-layer features to generate a fused feature map. The fused feature map is then shared by region proposal network (RPN) and Fast R-CNN. In the RPN system, we employ a novel dimension cluster method to predict the anchor sizes, instead of choosing the properties of anchors manually. Our detection method improves the detection accuracy and saves computation resources. The results show that our proposed method respectively achieves 85.21% and 91.16% on the mean average precision (mAP) for DIOR dataset and UA-DETRAC dataset, which are respectively 1.32% and 1.49% improvement than Faster R-CNN (ResNet152). Also, since less operations and parameters are required in the base network, our method costs the storage size of 42.52MB, which is far less than 214.89MB of Faster R-CNN(ResNet50).

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