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
135 巻 , 2 号
選択された号の論文の20件中1~20を表示しています
特集:フレキシブルフィルムデバイスのための材料・プロセスと評価技術
特集解説
  • 臼井 博明
    2015 年 135 巻 2 号 p. 140-145
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    Interface between inorganic electrode and organic layer bears various problems, such as poor adhesion strength and charge injection barrier due to inconsistency in physicochemical properties of both materials. This paper reviews the experimental results of using self-assembled monolayers (SAMs) that have reactive terminal groups to resolve the problems of organic/inorganic interface. Polymer thin films that are covalently tethered to inorganic surfaces can be prepared by vapor-depositing monomer molecules on the substrates that were modified with SAMs having a function of polymerization initiator. The reactive units can be amino group for ring-opening polymerization, azo group for UV-assisted vinyl polymerization, and benzophenone unit for thermally-assisted vinyl polymerization. A polymer thin film prepared by spin-coating can also be tethered via a benzophenone-terminated SAM by photochemical reaction. The chemical tethering at the interface resulted in increase of adhesion strength, improvement of surface morphology, and increase of charge injection from the inorganic substrates.
特集論文
<電子物性・デバイス>
<生体医工学・福祉工学>
  • Daluwathu Mulla Gamage Preethichandra, 小野田 光宣
    2015 年 135 巻 2 号 p. 174-180
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    In order to improve biosensor performance namely, the sensitivity, response time, and linear range values, novel amerometric polypyrrole (PPy) glucose biosensors, achieved by three different immobilizing techniques namely, physical adsorption, coentrapment and a two steps method of coentrapment superimposed with physical adsorption had been studied. Different enzyme loading and material properties resulted in varied immobilizing techniques lead to dissimilarities in characteristics. In this study, Pt coated AnodiscTMs with 0.2 µm maximum pore size were used as electrodes to polymerize PPy at 0.3 mAcm-2 using a solution containing 0.05 mol/l pyrrole and 0.1 M NaPF6. The polymerization time was optimized to 90 s. In the coentrapment method, glucose oxidase (GOx) (1 mg/ml) was added to the monomer solution while an aliquot of GOx (5 µl) was placed on the pre-polymerized electrode for physical adsorption. A combined procedure of these two techniques was used as the last immobilization technique. Physical adsorption method gave a sensitivity of 3 mAcm-2 (mol/l)-1 and a linear range of 0.5-13×10-3 mol/l with a response time of a 3 s. Sensitivity in the case of coentrapment was 3.75 mAcm-2 (mol/l)-1 while it showed a value of 4.45 mAcm-2 (mol/l)-1 in two step immobilization thus giving 25 and 48 % increases respectively. Response times of 9 and 8 s in latter cases reveal the possible repercussion taking place at enzyme immobilization in three dimensional (3-D) PPy matrix and the delay occur in glucose to reach the enzyme. Linear range of the two step method was extended up to 16×10-3 mol/l due to the reinforced enzyme loading.
論文
<電気回路・電子回路>
  • Kenji Takato, Hitoshi Kijima, Kazuo Murakawa, Hiroshi Iwao
    2015 年 135 巻 2 号 p. 181-190
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    We have already reported(3)-(6) that the capacitance of Surge Protective Devices (SPDs), such as varistor type SPDs, degraded the transmission rate of power line communication modems. Not only the capacitance of the varistor but also the inductance of the varistor and wiring of SPD cause LC series resonance and attenuate signal level at the resonant frequency. In this paper, we found that there is a close relationship among capacitance, maximum current, size of disk, and varistor voltage. The inductance is the sum of SPDs themselves and wiring connecting SPDs to AC power lines. Therefore how to install SPDs and connect them to Protection Earth (PE) is important. Typical varistor type SPDs that have 1000pF to 14000pF and wiring less than 50cm will have resonant frequency somewhere between 2MHz to 30MHz. We propose practical information to select and install SPDs on AC power lines, and to estimate PLC signal degradation.
<情報通信工学>
  • Satoshi Yamazaki, David K. Asano
    2015 年 135 巻 2 号 p. 191-196
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    In our previous research, we proposed a serial unequal error protection (UEP) code system for use with information sources that contain a mixture of both important and less important data. Previously, theoretical analyses were presented, and the effectiveness and the validity of the system for additive white Gaussian noise (AWGN) channels were confirmed using theoretical analyses and computer simulations. On the other hand, we proposed an adaptive error prediction filter with a decision feedback equalizer (AEPF-DFE) to achieve faster convergence and lower computational cost during the tracking period. In this paper, we proposed our UEP system using AEPF-DFE for time and frequency selective fading channels. We confirmed the improvement in BER performance and the effectiveness of adaptive equalization for the proposed system in fading channels. Also, we confirmed the predominance of the proposed system by comparing the previous scheme, that is, the case using a simple DFE.
<生体医工学・福祉工学>
  • 石井 賢治, 川合 洋子, 鶴岡 典子, 布施 貴大, 小原 拓, 松永 忠雄, 今井 潤, 芳賀 洋一
    2015 年 135 巻 2 号 p. 197-203
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    To improve the reliability of medication record keeping, we have developed a cup-shaped medication recording device and system for taking intraoral pictures of pills. This device has a camera, a memory card with a wireless transmitter, a capacitance sensor, a processing unit, and a rechargeable battery in the cup. When the capacitance sensor used as the trigger switch detects water level change, the camera starts shooting and takes some intraoral pictures. Waterproofing is achieved by the use of wireless data transmission and wireless battery recharging to enable washability of the cup. In the first experiment, ten trials in one subject were conducted. There were 2.6±0.7 pictures per an action of taking pill. The pill was successfully photographed in all trials. Thirteen subjects participated in a second experiment. Intraoral pictures of pills were taken and sent to a PC or a server wirelessly in all subjects. These results show that this device can be expected to reliably record medication, to improve patient adherence, and reduction of medical labor.
<システム・計測・制御>
<音声画像処理・認識>
  • 熊谷 章平, 堀田 一弘
    2015 年 135 巻 2 号 p. 236-243
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    In the field of cell biology, particle counting in intracellular images is important for investigating the cause of diseases. However, particles are manually counted by human observers now. Such manually counting takes a lot of time, and counting result becomes subjective. If an automatic counting method by computer is realized, we can treat a large number of images and it can obtain many objective data. The development of an automatic counting method much contributes to understand the case of disease. However, particle counting in intracellular images by a computer is new research field, and conventional methods are little. Thus, we propose counting method based on regression analysis. We use partial least squares regression and auto-correlation between 2 different types of features using mask patterns for higher-order local autocorrelation feature. The proposed method gives higher accuracy than counting by principal component regression, support vector regression and ImageJ. In experiment, the proposed method can count with small error in comparison with human counting. The effectiveness of our method is shown by experiments.
  • 中谷 一輝, 藤本 太平, 川村 新, 飯國 洋二
    2015 年 135 巻 2 号 p. 244-253
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    This paper proposes an active noise control (ANC) system based on speech enhancement using inverse notch filter (INF). Conventional ANC systems remove an observed signal, even if it includes a desired speech signal. To extract the desired speech signal, we introduce a speech reduction method as pre-processing of the ANC system. In this case, the ANC produces only the noise replica, since the input signal to the ANC does not include the speech signal. We inversely use a speech enhancement technique to achieve speech reduction. One of the useful speech enhancement techniques is a spectral gain method. Inherently, the spectral gain method based on the FFT provides a delay depending on the analysis frame length. Since the ANC system can work well under a low processing delay, we replace the FFT with the INF which is a narrow band-pass filter for reducing processing delay. Simulation results show that the proposed ANC system with INF is effective to extract the speech signal included in the observed signal.
<ソフトコンピューティング・学習>
  • 落合 広樹, 金澤 貴彦, 田村 健一, 安田 恵一郎
    2015 年 135 巻 2 号 p. 254-264
    発行日: 2015年
    公開日: 2015/02/01
    ジャーナル 認証あり
    In this paper, we introduce a new concept of hierarchical structure into solution space of a combinatorial optimization problem, and develop a novel combinatorial optimization method based on the concept. The introduction of the above new hierarchical structure concept “basin of attraction”, which is a set binding solutions by utilizing properties of local optimal solutions, enables us to construe solution space as not only set of solutions but also set of basins of attraction hierarchically. It is well known that the appropriate balance of two policies, intensification and diversification, is essential in the search of meta-heuristics. The proposed method clarifies the search policy by relating the hierarchical structure in solution space with intensification and diversification. In regard to diversification, we incorporate a movement strategy that has longer-term or more macroscopic viewpoint than before in the algorithm by utilizing the concept basin of attraction. The performance of the proposed combinatorial optimization method is inspected by numerical experiments using some typical benchmark problems of a traveling salesman problem, a knapsack problem, a flow-shop scheduling problem and a quadratic assignment problem.
 
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