電気学会論文誌C(電子・情報・システム部門誌)
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
140 巻, 3 号
選択された号の論文の25件中1~25を表示しています
特集:スマートシステムと計測・制御技術—IoT時代の計測・制御技術—
特集論文
<情報通信工学>
<システム・計測・制御>
特集研究開発レター
<生体医工学・福祉工学>
<システム・計測・制御>
特集:
産業応用をにらんだ高周波システム・電子デバイス・回路・材料技術
特集論文
<電子物性・デバイス>
  • 長野 健介, 河合 正, 榎原 晃
    2020 年 140 巻 3 号 p. 342-347
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    Microwave power dividers play important roles in microwave circuit systems. As an in-phase divider, the Wilkinson power divider which consists of two quarter-wavelength transmission lines and a resistor connected between two output ports is well known. However, the circuit size becomes large because this divider is designed based on a distributed circuit theory. This problem is extremely serious at low frequency regions such as VHF and UHF bands. Although some power dividers utilizing Π- or T-networks have been already reported in order to overcome this problem, these dividers have relatively narrow bandwidths. On the other hand, authors have been also proposed broadband lumped-element power dividers utilizing LC-ladder circuits.

    This paper describes a design method of multi-section LC-ladder dividers at VHF band. The multi-section LC-ladder divider is a broadband lumped-element power divider composed of multi-section LC-ladder circuits and an isolation resistor. By designing the divider based on multi-section impedance transformer and L-type matching techniques, broadband characteristics of a relative bandwidth of over 100% can be obtained at VHF band. Electromagnetic simulation and experiment for the designed divider have been performed in order to verify the design procedure. The measured results of the fabricated LC-ladder divider at a center frequency of 178MHz utilizing commercial chip elements are good agreement with simulation results.

<電気回路・電子回路>
論文
<情報通信工学>
  • 二井 克, 奥田 隆史
    2020 年 140 巻 3 号 p. 354-363
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    Internet of Things (IoT) data processing systems must handle massive and many kinds of data. Hence, it is important for designing IoT data processing systems to evaluate a performance of GI/G/s/s typed systems. The exact solutions of GI/G/s/s typed systems have not been yet developed. Alternatively, we apply a discrete simulation method to evaluate the systems. However, the method spends much time to evaluate the performance with any conditions. In our previous study, we have evaluated a performance of GI/G/s typed systems with infinite capacity by using machine learning. However, we have not evaluated a performance of loss traffic systems (GI/G/s/s typed systems with finite capacity). In this paper, we evaluate a performance of the systems by using machine learning and validate what kind of training data should we use.

<生体医工学・福祉工学>
  • 津田 純慈, 飯村 遊大, 鳥井 郁洋, 伊藤 薫, 山口 雄平, 岡野 菜々, 寺田 昌弘, 今村 誠
    2020 年 140 巻 3 号 p. 364-374
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    This paper proposes a joint vector model and a motion check rule format for an exercise guidance system to help beginners to learn exercise by themselves. Our joint vector model can describe the difference between correct/incorrect motions by the angles and the distances between vectors from joints to joints. Our format can describe planning knowledge that consists of precondition, time and actions for distinguishing correct/incorrect motions based on the joint vector model, so that it can generate guidance sentences depending on the types of error motions. We evaluate the description ability of the joint vector model by describing the check points in a text book concerning the Japanese popular radio exercise No. 1. Furthermore, we evaluate the usability of guidance, the times required for creating motion check rules, and the execution times by implementing an exercise training support system.

  • 大西 智也, 田中 雅博
    2020 年 140 巻 3 号 p. 375-383
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    In the field of rehabilitation, Stroke Impairment Assessment Set (SIAS) is used to evaluate the body dysfunctions for the post-stroke that is the disease of the brain. We have been developing automatic evaluation systems for the motor dysfunction in SIAS by using the detected joints of the body by using depth sensor. However, the joint detection is a specific function to Kinect and is not always possible for other depth sensors. Moreover, even when using Kinect, the positions of the joints are not correctly estimated when observed from the backward or with irregular poses. Thus, it is often inevitable to analyze the body poses from depth data directly. In this study, we directly apply depth data to the trunk function tests and joint movements of SIAS. The measuring method of angles from the raw depth data will be proposed, and the results are compared to the traditional test method of SIAS.

<システム・計測・制御>
  • 小林 正樹
    2020 年 140 巻 3 号 p. 384-390
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    It has been shown that it is possible to construct an ideal ANC system in which the noise source signal is a white signal by applying a dither signal having a power spectrum that is the inverse of the noise source signal. The noise source signal is a random signal that has reached to the microphone via the plural number of long distance acoustic paths. Therefore, the deviation of the frequency characteristic of the power spectrum is considered to be large. The nature of the system that the noise source signal is equivalently replaced by a white signal is extremely significance. The main aim of the paper is to verify the basic principle of this high speed ANC system to the actual noise. A method of generating an external dither signal with a power spectrum that is in reciprocal relation to the power spectrum of the noise source signal is discussed. Also, a practical normalized adaptive algorithm and a range of stable step size are derived. Finally, numerical verifications with actual noise source signal is performed by computer simulation, and the features and effectiveness of the proposed system are summarized.

<ソフトコンピューティング・学習>
  • 李 欣, 新井 洋, 濱上 知樹
    2020 年 140 巻 3 号 p. 391-397
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    A method for the estimation of wave-making resistance from the hull form and Froude number through deep learning is proposed. At the same time, this research also gives a solution when the data are skewed, which solves the problem of low generalization performance. The reduction of wave-making resistance is an essential issue in hull form design. However, the estimation of wave-making resistance is a time-consuming task that depends on experimental measurements. To enable direct estimation of the wave resistance from hull form, deep learning, which enables end-to-end learning, is an effective approach. The proposed method has two phases. First, auto-encoders, which reduce the dimension of the offset and the profile data, are generated, while performing to the skewed offset data, use an improved sampling method. Subsequently, after the regularization of these data, a deep neural net for regression estimation of wave-making resistance is generated. The results of evaluation experiments show that the proposed method can estimate wave-making resistance with high precision.

<情報システム,エレクトロニック・コマース>
  • 米原 三揮, 半田 岳志, 松鹿 弥生, 小泉 稔, 富山 友恵
    2020 年 140 巻 3 号 p. 398-408
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    The demand for navigation is rising as railway transportation services is becoming complex. Real-time data integration from multiple business systems is required for passenger-oriented navigation. Conventional mediators, real-time data integration technique which converts queries and data between business systems and applications based on their each schemes and mapping between them, can not follow expansion both of applications and business systems. In this paper, we propose a new mediator to solve the scalability problem with core-global scheme, which allows independednt mappings with each schemes of them and expresses principal components of business systems and applications. The 2 features of core-global scheme reduce effects of scheme changes on other mappings so that the mediator has scalability. Furthermore, we propose an architecture of the mediator that reduces effectivity loss of queries. We implemented a prototype and evaluated its scalability and query effectivity for an application of railway navigation.

研究開発レター
<生体医工学・福祉工学>
  • Ayaka Masaki, Kent Nagumo, Kosuke Oiwa, Akio Nozawa
    2020 年 140 巻 3 号 p. 409-410
    発行日: 2020/03/01
    公開日: 2020/03/01
    ジャーナル 認証あり

    A large number of traffic fatalities are caused by falling asleep at the wheel. Several drowsiness detection technologies have been developed in recent years. A previous study describes how hemodynamics can vary significantly due to drowsiness. However, it was difficult to estimate drowsiness from the time series of hemodynamics. In this study, general models for estimating three drowsiness levels (i.e., high, medium, and low) based on hemodynamics were constructed using a convolutional neural network for detecting the condition before a state of complete sleepiness is reached, the goal being traffic accident prevention. The results showed that the accuracy of the model was 68.9%.

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