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
134 巻 , 8 号
選択された号の論文の28件中1~28を表示しています
特集:産業界における新たな通信・ネットワーク技術の活用
巻頭言
特集論文
<電気回路・電子回路>
<情報通信工学>
  • 森岡 和行, アサノ デービッド
    2014 年 134 巻 8 号 p. 1010-1015
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    In this paper, CPM-OFDM systems which use CPM (Continuous Phase Modulation) as the first modulation scheme of OFDM (Orthogonal Frequency Division Multiplexing) are considered. As is the case for conventional OFDM systems, PAPR (Peak to Average Power Ratio) reduction is the most important task in CPM-OFDM systems. PAPR reduction by varying the initial phase of each sub-carrier with a fixed offset and a random offset are proposed. In the random offset method, the initial phase of each sub-carrier is not known at the receiver side, so we propose a demodulation algorithm using the phase continuity property of CPM and MLSD (Maximum Likelihood Sequence Detection). Simulation results show that the PAPR performance is improved if we use the random offset method. Also, we found that even though the initial phase is unknown at the receiver, the proposed algorithm can demodulate CPM-OFDM symbols as well as an algorithm where the initial phase is known.
  • 平田 孝志, 村口 正弘
    2014 年 134 巻 8 号 p. 1016-1023
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    This paper proposes a dynamic lightpath establishment scheme considering power consumption and four-wave mixing (FWM) in all-optical networks. In all-optical networks, an optical amplifier is used to amplify a group of optical signals of different wavelengths in a fiber without O/E/O conversion. Even if only one optical signal passes through an optical amplifier in a fiber, the optical amplifier operates. Thus, to efficiently use power of the optical amplifier, multiple optical signals in the fiber should be simultaneously amplified. FWM is one of the most important physical impairments to be resolved in all-optical networks because FWM decays the performance of all-optical networks. The FWM power in a fiber increases with the number of wavelengths used in the fiber. Therefore, in order to reduce the FWM power, it is preferred that optical signals are transmitted on different fibers. The proposed scheme provides an ingenious route, wavelength, fiber selection strategy considering the tradeoff between the power consumption and the FWM power. Furthermore, the proposed scheme avoids blocking of lightpath establishment due to depletion of wavelength resources. Through simulation experiments, we show that the proposed scheme efficiently reduces the blocking probability, the power consumption, and the FWM power in case of the number of fibers is fixed.
<システム・計測・制御>
  • 美濃谷 直志, 落合 克幸, 溝田 勉, 森澤 文晴, 藤井 孝治, 森村 浩季, 品川 満
    2014 年 134 巻 8 号 p. 1024-1030
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    Estimation of communication zone for contactless electric-field intrabody communication (IBC) with a side electrode on the wall of a security gate is studied. The IBC with a side electrode has two transmission paths between a mobile device and the side electrode. By using a proposed method of measuring two capacitances corresponding to two paths, human position dependency of capacitances is obtained. Communication zone estimated from measured capacitances is consistent with the measured one.
  • 上田 和樹, 鞠谷 達士, 矢向 高弘
    2014 年 134 巻 8 号 p. 1031-1038
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    In this paper, an Ethernet device using two ring buffers was implemented in order to achieve a parallel realization of a real-time communication and an IP communication. Using a conventional device driver, it is difficult to realize such a parallel realization. This is because the non real-time frames (IP frames) are processed using a NAPI mechanism, which introduces large delay and variation. Therefore, processing flows of the real-time frames (RT frames) must be separated from that of IP frames. A proposed mechanism was implemented by modifying the existing open source device driver to realize the flow separation mentioned above. By the modifications of the device driver, the RT frames and the IP frames can be distinguished and managed in the different ring buffers. RT frames are sent to a real-time frame ring buffer and they are processed immediately by using a hardware interrupt. IP frames are processed regularly by the conventional Linux network stack. By implementing them, the proposed device driver achieved 100µs or lower RTT (Round Trip Time) with a real-time communication in parallel with 500Mbit/s or wider bandwidth of IP traffic load. This paper shows the design, the implementation, and the evaluation of the priority processing device driver.
論文
<光工学>
  • 福地 哲生, 布施 則一, 水野 麻弥, 福永 香
    2014 年 134 巻 8 号 p. 1039-1048
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    Improvement of the in-plane spatial resolution in cross-sectional imaging using terahertz waves was investigated. The effects of frequency filtering, which limits the frequency range of the terahertz waves, and unsharp mask processing, based on a two-dimensional convolution of the imaging result and a mask consisting of a linear combination of the original image and a Laplacian filter, were evaluated. The filtering methods were successful in improving the spatial resolution up to the sampling limit of 0.4 mm. The combination of frequency filtering and unsharp mask processing was found to be effective for improving the contrast in addition to the spatial resolution. Frequency filtering, unsharp mask processing, and their combination were applied to terahertz wave cross-sectional imaging of an IC card.
<生体医工学・福祉工学>
  • 種池 卓哉, 田中 元志, 新山 喜嗣
    2014 年 134 巻 8 号 p. 1049-1055
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    In order to study on event-related potential (ERP) in opinion tests of picture quality and food evaluation, the ERPs were measured at 14 electrode positions by the same evaluation method with the same picture, and the same subjects. The pictures of sushi were used. ERP waveform of opinion tests with stimulus-comparison and single-stimulus methods were compared. In result, the ERP waveform of picture quality test has one peak, and the waveform of food preference test has two peaks. The P300 amplitude in the cases of picture quality and food preference tests with stimulus-comparison method is different at Fz and F7. And there is no significant difference between P300 amplitudes of the cases with stimulus-comparison and single-stimulus methods in food preference test. These results indicate that a difference by evaluation method is small, and the content of the evaluation task such as picture quality or food preference is one of the causes.
  • 酒井 洸児, 榛葉 健太, 有松 和之, 小谷 潔, 神保 泰彦
    2014 年 134 巻 8 号 p. 1056-1063
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    Myelination is essential for rapid conduction of action potentials in central nervous system. The loss of myelin leads to impairment of motor and cognitive functions. Remyelination by transplantation of oligodendrocytes (OL) is a potent therapeutic strategy for the demyelinating diseases. However, little is known about how the conduction velocity increases after remyelination. Here, the aim of this study is to develop a culture device for evaluating the change in action potential conduction velocity along axon in co-culture of neurons and OL. We developed the culture device which composed of a culture chamber and a microelectrode array (MEA). The chamber has two neuron culture compartments and four OL culture compartments which are interconnected by four microchannels. Electrodes of the MEA were in alignment with the microchannels. Cortical neurons and OL were cultured separately with a co-culture chamber. OL maturation and axon outgrowth through the microchannels were confirmed by immunofluorescence imaging. After neural activities were recorded, spike sorting was performed to separate spikes into clusters of individual neurons. The propagations of action potentials along axon were detected from spike trains. Then, the conduction velocity increased with culture days. These results suggest that this device can be utilized for evaluating the change in action potential conduction velocity in myelination process.
  • 高橋 和佐, 白松(磯口) 知世, 野田 貴大, 神崎 亮平, 中原 はるか, 高橋 宏知
    2014 年 134 巻 8 号 p. 1064-1070
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    We developed an experimental system to simultaneously characterize tonotopic activities of both the auditory cortex and thalamus of rats, each with a number of microelectrodes. The system consisted of a custom-designed surface electrode array and depth electrode array. The surface electrode array had 64 recording points in a 4.5 mm × 3 mm area. Between the recording points holes were made, through which the depth array was inserted. The depth array had 3 shanks, each of which was 6 mm long with an inter-shank distance of 500 µm. Each shank had 15 recording sites for the thalamus and 17 for the auditory cortex. To precisely insert the depth array perpendicularly to the cortical surface, a laser displacement meter was used. We measured tone-evoked local field potentials and multi-unit activities in the auditory cortex and thalamus of rats under anesthesia, and characterized tonotopic maps simultaneously in the auditory cortex and thalamus.
  • 武田 尚子, 工藤 卓, 田口 隆久, 細川 千絵
    2014 年 134 巻 8 号 p. 1071-1077
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    Living neuronal network in neural systems communicate through synaptic connections. For aiming artificial control of the synaptic transmission in neuronal network, we have applied conventional optical tweezers using a focused near-infrared (NIR) laser. The optical trapping of neural cell adhesion molecules (NCAMs) labeled with quantum-dots (Q-dots) at the plasma membrane of living neuronal cells was achieved at high laser power (>300 mW) in our previous study; therefore, the further reduction of laser power was required. Here, we propose and demonstrate resonant optical tweezers of Q-dots attached to NCAM in a neuron by simultaneous irradiation with non-resonance and resonance laser beams. The optical trapping dynamics of them was revealed by fluorescence correlation spectroscopy (FCS). The transit times of Q-dots attached to NCAM at the focal spot increased with the simultaneous irradiation of NIR laser and resonance laser. These results suggest that the particle motion of Q-dots attached to NCAM was constrained at the focus spot due to optical trapping force enhanced with resonance laser irradiation. Our method is applicable to selective manipulation of signaling molecules in living neurons.
<システム・計測・制御>
<ソフトコンピューティング・学習>
  • 篠原 靖志, 嘉屋 健, 松谷 悠司
    2014 年 134 巻 8 号 p. 1138-1147
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    Japanese electric power companies widely use the gas-in-oil based diagnostic criterion, which was developed in 1999, for determining the anomaly ranking of intermediate joint boxes of single-core cables during the maintenance of oil-filled cable joint boxes. However, it can determine neither the fault location nor aid in the diagnosis of terminal joint boxes. In addition, several joint boxes that are determined as normal using this criterion have recently been found to be anomalous in the overhaul. In this paper, we propose a new relatively accurate diagnostic criterion that covers both the intermediate and terminal joint boxes and aids in determining the anomaly ranking and fault location using the multiclass ν-linear support kernel machine (SKM), which we propose as an extension of the linear support vector machine (SVM). The proposed multiclass ν-linear SKM automatically scales data to maximize the performance of the linear SVM and obtains simpler linear evaluation functions. Furthermore, it is formulated as a linear programming problem, whereas general SKMs are formulated as semi-definite programming problems that are difficult to solve. The accuracy of our proposed linear criterion, which was estimated using 5 fold cross-validation, was approximately 75% which was almost comparable to 76% by the one-against-one non-linear RBF-support vector machine.
<情報処理・ソフトウェア>
  • Huiquan Zhang, Sha Luo, Osamu Yoshie
    2014 年 134 巻 8 号 p. 1148-1156
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    The discovery of associations between local facial features and image features is one of the current challenges in regard to facial expression recognition. To mitigate the negative effects caused by individual differences, this paper proposes an approach based upon human cognition which can recognize facial expression from six human cognitive regions. The proposed approach exploits descriptions of Local Binary Pattern (LBP) to extract the holistic facial area and establishes a pseudo 3D face model for segmenting the human face into six cognitive regions. Finally, we synthesize change trends and volume distribution of LBP of the six regions to recognize the expressions. Unlike many previous studies, this approach recognizes the expressions from regional features instead of holistic facial features. Further, the regional features are more robust than interesting point-based features because of idiosyncrasy of individuals. To validate our proposed approach, we conducted experiments on the Extended Cohn-Kanade (CK+) facial expression database. The results demonstrate that the proposed approach can effectively segment face into specific areas and recognize facial expressions.
  • 和田 典子, 小坂 満隆
    2014 年 134 巻 8 号 p. 1157-1163
    発行日: 2014年
    公開日: 2014/08/01
    ジャーナル 認証あり
    We have seen great variability in the outcomes of activities to improve the capabilities of software development, and that such variability has been attributed primarily to the skills and experiences of promoters of individual support activities. In this paper, we propose an approach of software development support activity that enhance the probability of achieving expected result with reference to service approach and organization management paradigms.
研究開発レター
<情報通信工学>
 
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