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
129 巻 , 12 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:電気関係学会東海支部連合大会
巻頭言
特集論文
<情報通信工学>
  • 平田 晃正, 長屋 義雄, 伊藤 亨基, 藤原 修, 長岡 智明, 渡邊 聡一
    2009 年 129 巻 12 号 p. 2102-2107
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    From an anatomically-based Japanese model of three-year-old child with a resolution of 1 mm, we developed a nine-month Japanese infant with linear shrink. With these models, we calculated the whole-body average specific absorption rate (WBA-SAR) for plane-wave exposure from 0.1 to 6 GHz. A conservative estimate of the WBA-SAR was also investigated by using three kinds of simple-shaped models: cuboid, ellipsoid and spheroid, whose parameters were determined based on the above three-year-old child model. As a result, the cuboid and ellipsoid were found to provide an overestimate of the WBA-SAR compared to the realistic model, whereas the spheroid does an underestimate. Based on these findings for different body models, we have specified the incident power density required to produce WBA-SAR of 0.08 W/kg, which is the basic restriction for public exposure in the guidelines of International Commission on Non-Ionizing Radiation Protection.
<生体医工学・福祉工学>
  • 宮崎 剛, 中島 豊四郎
    2009 年 129 巻 12 号 p. 2108-2114
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    In this paper, we propose a lip-reading method based on lip-reading skill holders. When they do lip-reading, they pay attention to the changes in mouth shape of a speaker. In recent years, some research into lip-reading using information technology has been pursued. There are some research based on the changes in mouth shape. The researchers analyze all data of the size of mouth shapes during utterance, whereas lip-reading skill holders look at the distinctive mouth shapes. We discovered that it is able to do lip-reading using the distinctive mouth shapes. To build the technique into a lip-reading system, we propose an expression method of the distinctive mouth shapes which can be processed with computer. And, we acquire knowledge about the relation between Japanese articulation and mouth shapes. We also define the method to express the order of the distinctive mouth shapes which are formed by a speaker.
<システム・計測・制御>
  • 名和 靖彦, 津田 紀生, 山田 諄
    2009 年 129 巻 12 号 p. 2115-2120
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    Small vibration sensors with the laser interferometer have been developed. However, there are some disadvantages, for example, weakness to external vibration, difficulty in optical alignment, and so on. These disadvantages are improved by making use of a self-coupling effect of a semiconductor laser, because this sensor is composed of only a laser diode and a lens. When a small vibration, whose amplitude is less than half-wavelength of the laser, is measured, a reference signal is needed. The reference signal is generated by moving the sensor head quickly. Also an output signal should be measured at maximum sensitivity. This output signal is observed by moving the sensor head slowly. The signal is controlled by a microcomputer. The vibration amplitude is evaluated from the ratio of the output signal to the reference one by the microcomputer. This sensor can detect a small vibration with minimum amplitude of about 3 nm, and a small vibration is able to be measured irrespective of the frequency in the range between 0.5 kHz and 3.0 kHz, and the target color.
  • 板倉 啓樹, 小中 英嗣
    2009 年 129 巻 12 号 p. 2121-2128
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    Switching control is used as a feasible control technique with low-resolution actuators, and it is modeled as a control system which restricts its input to discrete values. The control performance of this control besically depends on the length of the control period and switching surface. Long control period will cause large chattering, and short control period will cause redundant switching and energy consumption. The design of switching surface is difficult problem for nonliner plant.
    In this study, firstly, a switching of discrete-valued control is considered as a timed discrete event. Secondly, propose a controller design method which realizes variable control period state feedback control by exploiting learning capability of neural network. The designed neural controller determines the control period and the switchng surface simultaneously. Finally, the usefulness of the proposed method is demonstrated through some numerical simulations.
  • 龍田 建次, 野呂 雄一, 吉久 光一, 久野 和宏
    2009 年 129 巻 12 号 p. 2129-2135
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    We have proposed a simple model to predict environmental noise in urban areas. In the model, the sound power level per unit area is estimated from the local traffic volume and the law of the conservation of energy is applied to derive the average value of LAeq in an area. In order to examine the actual relation between environmental noise and road traffic networks and verify the proposed model, field data on environmental noise and the distance traveled by vehicles in Nagoya City were analyzed statistically. The field data were converted into the grid square data by using GIS in 12 areas of the city. It has been found that a strong relation between LAeq and the distance traveled by vehicles is observed for each area. When the exceptional larger values of noise data are excluded and the observation time of LAeq becomes sufficiently large, the coefficients of determination exceed 0.8. The strong relation between them found to be consistent with that derived from the proposed simple model.
  • 森田 良文, 横井 彰敏, 岩崎 誠, 鵜飼 裕之, 松井 信行, 伊藤 徳久, 瓜生 信彦, 向井 靖彦
    2009 年 129 巻 12 号 p. 2136-2143
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    In this paper a new control method of Electric Power Steering (EPS) system with Variable Gear Transmission System (VGTS) is proposed. The control purpose is to achieve the desired steering gear ratio and the desired power assist with good steering feel. The basic idea of controller design is to apply decoupling control to this system and to separately design controllers for two decoupled systems. The angle control system and the torque control system are designed for the decoupled systems. In the angle control system the PID control is used for the desired gear ratio. In the torque control system the PID control is used for the desired assist torque designed so as to achieve good steering feel. In order to evaluate steering feel the Lissajous curve between the steering torque and steering angle is used. The effectiveness of the proposed controller is verified experimentally.
<音声画像処理・認識>
  • 澁谷 尚志, 横田 康成
    2009 年 129 巻 12 号 p. 2144-2151
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    In recent years, damage to agricultural products, livestock, and power transmission systems by crows is regarded as a serious problem; countermeasures against crow damage are urgently necessary. This paper proposed a method for detecting crow calls in various environmental sounds. If detection and discernment of crow calls were possible, various actions could be undertaken to prevent the damage. Wildlife call detection, not only that for crows, should be executed in extremely noisy environments. We then introduced both a spectrograph estimation technique with AR modeling in which AR coefficients are temporally smoothed and interpolated and a background noise elimination technique to obtain higher-quality crow call templates. The input sounds are compared with these templates by DP matching in the metric vector space of a logarithmic cepstrum. Every input sound whose minimal distance to the template database is less than the specified threshold value is detected as a crow call. The maximal detection performance can be obtained when five call templates in the template database are utilized; the implication is that carrion crows have five distinguishable call patterns. It is shown that the proposed method achieves 95% detection rate when 1.66% misdetection rate is allowed.
<情報処理・ソフトウェア>
  • 後藤 優, 田中 敏光, 佐川 雄二
    2009 年 129 巻 12 号 p. 2152-2158
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    This research presents a method to display realistic flow of water drops on windshield in real time. The grid system well simulates irregular movements of the water drops on glass surfaces. Realistic shape of the water drops can be displayed by combination of metaballs. Fusion and separation of water drops can be expressed by gathering and distancing metaballs, respectively. However, if windscreen wipers scoop many metaballs in one cell of the mesh, they fuse to one huge water drop. It is very strange. On the other hand, the particle system is suitable to display thin dollop of water along windscreen wipers, because particles push each other. Thus, by the distance from the wipers, our method selects one from those two methods properly. Although shapes of the water drops are defined with 2D metaballs, quality of the shapes is comparable to 3D metaballs, both in nature and smoothness, because our method compresses height of the 2D metaballs non-linearly. Our method can manipulate and render water drops on windshield in real-time by using GPU.
特集研究開発レター
<情報通信工学>
<システム・計測・制御>
<情報処理・ソフトウェア>
論文
<電気回路・電子回路>
  • Hao San, Hajime Konagaya, Takafumi Yamada, Haijun Lin, Haruo Kobayashi ...
    2009 年 129 巻 12 号 p. 2167-2173
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    This paper proposes an improved architecture of the noise-coupled ΔΣAD modulator with OP-Amp sharing technique. The noise-coupled ΔΣAD modulator enhances the order of noise-shaping efficiently by adding some passive capacitors and switches. However, in a conventional noise-coupled ΔΣAD modulator with feedforward path, an analog adder is needed before the quantizer, and especially in a multibit modulator, an additional amplifier is necessary to realize the summation of feedforward signals and coupled quantization noise, which leads to extra chip area and power dissipation. In this paper, we propose a novel architecture of the noise-coupled ΔΣAD modulator with OP-Amp sharing technique, which realizes the summation of feedforward signals and coupled quantization noise without an additional amplifier. The proposed architecture is functionally equivalent to the conventional noise-coupled modulator with smaller chip area and low power dissipation. We have performed simulation with MATLAB and SPICE to verify the effectiveness of the proposed architecture and modulator circuits. The simulation results show that the proposed modulator can realize the noise-shaping enhancement effectually as the same as the conventional noise-coupled modulator with small overhead.
<情報通信工学>
<生体医工学・福祉工学>
  • 酒井 太郎, 吉永 崇, 今井 崇雄, 桝田 晃司
    2009 年 129 巻 12 号 p. 2180-2188
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    Echography (ultrasonography) is indispensable equipment in every medical field but examination with echography greatly depends on the expertise and experience of an operator. Recently a tele-echography system, where a medical doctor obtains echograms of a remote patient to diagnose, has been proposed as an application of telemedicine by connecting between them using high-speed network and introducing a portable echography. However, it is difficult to obtain standard cross sections of heart if a person who handles the probe beside the patient is not skilled in echography. Thus we have developed a support system to acquire suitable echocardiograms for diagnosis independently by extracting the shape of left ventricular wall into an ellipse in real-time and measuring the position of the probe. As the result of evaluation experiments, we have confirmed the possibility for an assistant system in tele-echography.
  • 加藤 康広, 柏野 牧夫, 廣中 直行
    2009 年 129 巻 12 号 p. 2189-2193
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    To advance understanding of the mechanisms of neural interactions, including complex electrical and biochemical reactions, we designed and fabricated a microdialysis probe with multichannel neural electrodes for simultaneously recording both electrical and chemical neural signals. The microelectrodes were fabricated on the curved surface of the guide cannula of the microdialysis probe by using micro-electro-mechanical systems technologies. The advantage of placing microelectrodes on the guide cannula is that, like conventional microdialysis probe, the part of membrane in the microdialysis probe can be removed and replaced without further surgery to the animal, depending on an experimental design or in the case of mechanical failure of the membrane. Because of difficulty in controlling the etching conditions to expose the microelectrodes, we applied only a wet process for this fabrication with photosensitive polyimide and electrodeposition resist. Photosensitive polyimide was used for base and insulated layers. Chromium-gold, patterned with electrodeposition resist as a sacrificial layer, was used for individual recording electrode sites, interconnect lines, and connection pads. In biochemical studies, the fabricated microdialysis probe with multichannel electrodes has satisfied the physical properties of electro impedance and the recovery rate of neural substances, permitting practical use for animal experiments.
<システム・計測・制御>
<音声画像処理・認識>
  • 山口 晃一郎, 加藤 武男, 二宮 芳樹
    2009 年 129 巻 12 号 p. 2213-2221
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    This paper proposes a method for estimating the ego-motion of the vehicle by using a vehicle mounted monocular camera. Our proposed method is based on Structure from Motion (SFM). There are two problems with applying a SFM algorithm in a real road environment. Firstly, a typical road scene contains moving objects, such as other vehicles. Secondly, roads display fewer feature points, compared to the number associated with background structures. These problems cause false estimations or reduce the accuracy of the estimated motion. Our proposed method detects moving objects in every frame and selects feature points used for motion estimation from all extracted feature points in the image, so that those feature points are dispersedly distributed in various regions except those containing moving objects. The ego-motion of the vehicle can be accurately estimated from correspondences of these selected feature points. In our experiments, it has been shown that the proposed method is able to estimate the ego-motion in real road scenes.
  • 山崎 彬人, 金出 武雄, 高氏 秀則, 大城 英裕, 金子 俊一
    2009 年 129 巻 12 号 p. 2222-2231
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    Nighttime images of a scene from a surveillance camera have lower contrast and higher noise than their corresponding daytime images of the same scene due to low illumination. We propose a denighting method that enhances nighttime images so that they are closer in quality to images taken during the daytime. Our denighting method is based on an observation. It exploits the simple fact that the static camera captures the same scene all day long, obtaining a large quantity of data about the scene. In particular, to enhance the nighttime image, we decompose the image into an illuminance layer, and a reflectance layer that is assumed to be the textures. We enhance the nighttime image by improving the illuminance of nighttime so that it is closer to the illuminance of daytime by using day and nighttime background illuminances that have already been computed. We present several results of the enhancement of low quality nighttime images using denighting.
<情報処理・ソフトウェア>
  • 中山 弘二郎, 大場 みち子, 薦田 憲久
    2009 年 129 巻 12 号 p. 2232-2238
    発行日: 2009/12/01
    公開日: 2009/12/01
    ジャーナル 認証あり
    XML Encryption is used for partially encrypting XML data to provide end-to-end confidentiality in multi-hop web services. An intermediary along the message path cannot perform schema validation on encrypted XML data because the data structure is changed by the partial encryption. To perform schema validation, it is required to provide a post-encryption schema. However, generating a post-encryption schema is not accomplished by simple replacement of element declarations because we have to consider an impact of the replacement and UPA violation problem. So, if we generate a post-encryption schema by hand, some technical skills about schema are required and take some operation time. In this paper, we propose a method for generating a post-encryption schema. By using our proposed method, technical skills aren't required because the proposed method requires only existing information such as an original schema and a security policy. Our evaluation experiment shows that the proposed method can reduce an operation time for generating a post-encryption schema.
研究開発レター
<電気回路・電子回路>
<生体医工学・福祉工学>
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