著者
柴田 正志 高橋 雅和
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.10, pp.1127-1133, 2020-10-01 (Released:2020-10-01)
参考文献数
26

In this paper, we propose an efficient method of technical structure analysis of FPGA development using network analysis. Recently, with the reform of the industrial structure called “Industry 4.0” and the explosive expansion of the application area of AI (Artificial Intelligence), the demand for computing power in edge devices is increasing. For these backgrounds, the acceleration by FPGA is focused on the industry. Hence, in this paper, we analyze the technology development trends of a significant FPGA supplier. As analytical data, we employ patents obtained by the company in the U.S. We focus on the classifiers in the patent information. We create graphs by classifiers and analyze their clusters. From the results of extracting graph features by the proposed method, key technology areas and their transitions are revealed in the technology development of FPGA suppliers.
著者
島袋 雄一 具志 翔太朗 又吉 淳二 比嘉 広樹
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.9, pp.1040-1049, 2020
被引用文献数
2

<p>In order to help people with disabilities of the upper extremities drink and eat, a simulator for self-feeding assistive robotic arm using solving method of inverse kinematics has been developed in this paper. Using inverse kinematics equations of 7 degrees of freedom (DOF) with an arm angle parameter, the robotic arm model was implemented in the simulator and its controller with mouse device was also designed. The arm angle parameter defined the angle between the arm plane and a reference plane was used to resolve the robotic arm redundancy. Three able-bodied persons participated in simulation experiments. They manipulated the robotic arm model in a virtual space using mouse device. It was found from the simulation results they successfully performed the drinking and eating tasks in our simulator.</p>
著者
西田 武弘 藤原 康文 山本 和久 小泉 淳 八木 哲哉
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.2, pp.181-186, 2020-02-01 (Released:2020-02-01)
参考文献数
31

Speckle reduction method for laser diode based displays was newly proposed. The method was based on temporal change of the active layer temperature which could be controlled by optimizing the driving condition of the laser diode under pulse. The red LD consisted of AlGaInP has low thermal conductivity and small energy difference between the active layer and the cladding one in the conduction band, resulting in the large temporal change of the lasing spectrum under the adequate driving condition in pulse. It indicates the speckle contrast could be controlled by changing the condition. The speckle contrast dependence on the driving condition of the high-power 638-nm lateral single mode laser diode was experimentally studied. In the experiment, not only the conventional square waveform but also the saw one were used. The speckle contrast under the adequate conditions for both waveforms was reduced approximately 25% compared with that under CW. In particular, the saw one might be expected as a very robust driving condition for the speckle reduction. This can be used with other speckle reduction method such as moving screen, moving diffuser and so on. In this sense, the newly proposal may be the speckle reduction method for “last one mile”.
著者
佐倉 衛 澤田 賢治 金子 修 新 誠一 松田 功
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.9, pp.1064-1073, 2020-09-01 (Released:2020-09-01)
参考文献数
19

In model-based development in the automotive industry, functional tests are performed using models made by CAE tools. The model needs to reproduce some physical properties of the target system correctly. The previous research of the current authors proposes energy balanced based verification (EBBV) that verifies the correctness of the model focused on the energy conservation law. EBBV confirms the balance of input and output energy of the model from output information of the model. In this paper, we develop three tools to automate EBBV processes. Also, we make a modeling guideline suitable for EBBV, which is composed of tagging and a hierarchical model structure. Through numerical experiments, we check that three tools automate EBBV processes for models according to the modeling guideline. The target model of the experiments is a mild hybrid electric vehicle model made by MATLAB/Simulink, MapleSim, and CarMaker.
著者
豊田 計時
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.122, no.4, pp.572-577, 2002-04-01 (Released:2008-12-19)
参考文献数
11

Waveform distortion of logic signal, by accelerating clock speed and improving implementation density, makes non-linear output for the input and has been giving behavioral problem to electronic system. There are overshoot type, hysteresis type, and undershoot type for transient waveform distortion. Deep undershoot could cause latchup for CMOS logic IC, data destruction for DRAM, pulse split for TTL IC, respectively. Undershoot of logic signal is not discussed only by transient phenomena (time domain ) but also by filter theory ( frequency domain). Time sequential resistance R variation by output circuit impedance variation causes such time domain variations as damping constant α and damping coefficient ζ. While resistance R variation causes Q variation in frequency domain. In this paper, an occurrence mechanism is shown that undershoot occurs when parasitic series resonance circuits are composed at load side of driving device and damping coefficient ζ varies time sequentially for totempole or complimentary circuits. PSpice simulation suggests that undershoot is reduced by controlling the phase of punch through current.
著者
小松 利彰 土方 嘉徳 才脇 直樹 西田 正吾
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.121, no.1, pp.118-126, 2001-01-01 (Released:2008-12-19)
参考文献数
8

User support by a computer is desired for creating computer graphics. Automatic generation of moving human crowd is one of such demands. The feature of human crowd is that the behavior of each figure is independent, but the crowd, as a huge mass of it, has a pattern as a whole. It is too troublesome if the user inputs the all coordinates data of this behavior. This paper describes the modelling method using chaos and electric charge model. Chaos is convenient to represent such features. Electric charge model can represent the detail of each figure's movement.
著者
安井 友徳 北村 尊義 泉 朋子 仲谷 善雄
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.7, pp.874-882, 2020-07-01 (Released:2020-07-01)
参考文献数
25

An immediate evacuation is essential for safety when a big earthquake and a tsunami occurred. For example, Great East Japan Earthquake in 2011 killed over 10 thousand people and over 90 percent of them drowned by the tsunami, that is, people who failed to escape from the tsunami after the earthquake occurred got losses by it. If they evacuated immediately after an earthquake, it would be possible that the losses could be limited. In this study, we analysis text-based information expression on a mobile device to induce immediate evacuation. We implemented an application which provides disaster information on a smartphone, and compare text expression about information of tsunami height, arrival time of tsunami, an expected number of evacuees, damage of buildings and so on. The results of the comparison verification show the sentence based on damage of building using fear-arousing communication is the most effective to induce evacuation in this study. However, in over seventies, the effectiveness of the sentence is less than half.
著者
豊泉 裕章 源田 正弘
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.125, no.8, pp.1217-1222, 2005 (Released:2005-11-01)
参考文献数
6
被引用文献数
1 2

GPS is widely used to obtain not only the position information but also the time information. Specially, it is used to synchronize the time between separate stations in the measurement system or the communications system. However, in these systems, the output circuit of the 1PPS signal in the GPS receiver has not been optimized. In this paper, we examine the error sources of the time measurement by GPS and show the time measurement accuracy is about 10 ns, and the improvement of the precision of 1PPS signal is most important to realize high accurate 1PPS signal. We propose the precise 1PPS generating method by the analog circuit whose output precision is sufficiently higher than the time measurement accuracy by GPS. We evaluated the time measurement accuracy and the accuracy of 1PPS signal in the relative time synchronization by 24 hours test, and succeeded to realize a few ns precision and several ns accuracy of 1PPS signal in the relative time synchronization using our precise 1PPS generating method.
著者
下田 義雄 佐藤 秀隆
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.119, no.8-9, pp.1004-1009, 1999-08-01 (Released:2008-12-19)
参考文献数
12

Reverse conducting thyristors are analyzed using a two-dimensional simulator to investigate the effects of substrate types, P-type or N-type, on transient characteristics. The ramp currents with four kinds of rise-time are applied to the thyristors. The thyristor with a P-type substrate shows faster turn-on time and lower clamping-voltage change than that of an N-substrate for the applied ramp currents. The excellent transient response to the P-type substrate thyristor is caused by the accelerated carrier, which results from the high electric field appearing in the P-base region.
著者
橋詰 賢一 山本 秀雄 伊佐 功 絹田 幸生 石川 勇 久米 信行 吉野 勝美
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.112, no.12, pp.828-834, 1992-12-20 (Released:2008-12-19)
参考文献数
6

Polyamic acid thin film was electrodeposited on metal foil using the solution containing triethyl-ammonium salt of polyamic acid dissolved in mixed solvent of DMF and methanol. The polyamic acid thin film was continuously imidized to form polyimide dielectric thin film, on which polypyrrole was polymerized as another electrode. Characteristics of this polyimide thin film as a dielectric is similar to that of polyimide film formed by spin coating technique. Applying this method to etched aluminium foil, small size film capacitor which has large capacitance and excellent characteristics was proposed.
著者
井上 卓弥 平山 高嗣 高橋 友和 川西 康友 出口 大輔 井手 一郎 村瀬 洋 黒住 隆行 柏野 邦夫
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.138, no.11, pp.1399-1409, 2018-11-01 (Released:2018-11-01)
参考文献数
23
被引用文献数
1

Recently, the spread of Web cameras has facilitated video-conferencing as a means of communication. Since a Web camera is usually located outside the display while the user looks at his/her partner in the display, there is a problem that they cannot establish eye contact with each other. Various methods have been proposed to solve this problem, but most of them required specific sensors, and robust and accurate feature extraction for various appearances to densely associate facial feature points of the images. In this paper, we propose a method that transforms the eye areas to synthesize eye contact using a single camera that is commonly implemented in laptop computers. Concretely, we implemented a system which transforms the user's eye areas in an image to his/her eye image with a straight gaze to the camera only when the user's gaze falls in a range that the partner would perceive eye contact. We then confirmed the effectiveness of the proposed method in terms of accuracy of the gaze area classification, subjective evaluation score for eye contact, and accuracy of eye contact through experiments.
著者
菅 博文 宮島 博文 関口 宏 晝馬 輝夫
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.125, no.2, pp.187-194, 2005 (Released:2005-05-01)
参考文献数
12

Recently, high power laser diodes (LDs) are appling the laser material processing. In this report, we have presented a brief overview of high power laser diode, and describe the basic technology of high power laser diodes and system for pumping solid state laser and direct applications.
著者
鈴木 裕 深澤 瑞也 森 鷹浩 阪田 治 服部 遊 加藤 隆也
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.130, no.3, pp.401-406, 2010-03-01 (Released:2010-03-01)
参考文献数
20
被引用文献数
4 4

It is desired to detect stenosis at an early stage to use hemodailysis shunt for longer time. Stethoscope auscultation of vascular murmurs is useful noninvasive diagnostic approach, but an experienced expert operator is necessary. Some experts often say that the high-pitch murmurs exist if the shunt becomes stenosed, and some studies report that there are some features detected at high frequency by time-frequency analysis. However, some of the murmurs are difficult to detect, and the final judgment is difficult. This study proposes a new diagnosis support system to screen stenosis by using vascular murmurs. The system is performed using artificial neural networks (ANN) with the analyzed frequency data by maximum entropy method (MEM). The author recorded vascular murmurs both before percutaneous transluminal angioplasty (PTA) and after. Examining the MEM spectral characteristics of the high-pitch stenosis murmurs, three features could be classified, which covered 85 percent of stenosis vascular murmurs. The features were learnt by the ANN, and judged. As a result, a percentage of judging the classified stenosis murmurs was 100%, and that of normal was 86%.
著者
脇 隼人 鈴木 裕 阪田 治 深澤 瑞也 加藤 初弘
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.132, no.10, pp.1589-1594, 2012-10-01 (Released:2012-10-01)
参考文献数
23
被引用文献数
1 2

The number of dialysis patients is approximately 300,000 and is increasing every year in Japan. A renal failure patient requires a hemodialysis shunt for dialysis to be performed; however, the blood vessels around the hemodialysis shunt may become stenosed. The stethoscope auscultation of vascular murmurs has some use in the assessment of access patency; however, this diagnostic approach is skill dependent. Therefore, a diagnostic support system to detect stenosis is desirable. We developed an auscultating diagnosis support system for assessing hemodialysis shunt stenosis by using a self-organizing map (SOM) and short-time maximum entropy method. In this paper, for the purpose of improving the accuracy of stenosis detection, the Mel-frequency cepstrum coefficient (MFCC)-based hidden Markov model (HMM) was also used. As a result, a high correlation between an SOM system and HMM system was found. Therefore, the credibility of the each system was confirmed. Furthermore, the results indicated that the accuracy of stenosis detection could be improved by combining the SOM and HMM methods.
著者
米原 三揮 半田 岳志 松鹿 弥生 小泉 稔 富山 友恵
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.3, pp.398-408, 2020-03-01 (Released:2020-03-01)
参考文献数
15

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.
著者
寺口 直希 南 政孝
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.140, no.3, pp.336-337, 2020-03-01 (Released:2020-03-01)
参考文献数
5
被引用文献数
2

The grid connection inverter is built in the PCS (Power Conditioning Subsystem) for the distributed power supply, such as photo voltaic system. Recently, there has been considerable advances in the research on power flow using PCS. In order to adjust the power in the PCS, it is necessary that the grid connection inverter of the PCS predicts the load and output fluctuation in the customer side. Therefore, this paper investigates a load estimation in the grid connection inverter of the PCS. The proposed estimation method adds a superimposing pseudo random binary sequence to the inverter reference. The validity of the proposed estimation method is verified experimentally. As a result, it is experimentally clarified that the estimation is possible even for inductive loads.
著者
渡部 泰明 佐藤 裕貴 五箇 繁善 佐藤 隆幸 関本 仁
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.127, no.8, pp.1192-1193, 2007-08-01 (Released:2007-09-01)
参考文献数
3

To improve the temperature characteristics of SC-cut oscillators without degrading their phase noise and short term stabilities, an oscillator circuit has been designed. This circuit uses an AT-cut resonator as a temperature reference of the output frequency, that is, the oscillation frequency of the SC-cut circuit traces the temperature characteristics of the AT-cut resonator. Experimental results show that the frequency stability for the temperature is improved 30 times better than normal oscillators.
著者
山中 隆 鹿嶋 雅之 佐藤 公則 渡邊 睦 緒方 淳
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)
巻号頁・発行日
vol.129, no.5, pp.792-799, 2009-05-01 (Released:2009-05-01)
参考文献数
11

Many researches have been done as for outdoor scene recognition by analyzing optical flow information. However, a practical driver-oriented system has not been proposed yet that notices the “Risk degree” when multiple obstacles exist, such as, parking cars and pedestrians. This article presents a new method to detect stand still obstacles using the “model flow” corresponding to optical flow field where there is no obstacle. The model flow is calculated using the knowledge as for navigation environments. Standard Points which are regularly set on image coordinates are transformed to Environment Points on road plane using several parameters such as, steering angle and camera tilt angle. Stand still objects are automatically detected by analyzing the difference between a model flow field and a real optical flow field which is acquired by an in-vehicle camera image. The algorithms have been installed in a desktop PC by Microsoft Visual C++6.0 programs. Experimental results by several kinds of outdoor scenes have shown the effectiveness of the proposed method. Total detection ratio is 91.0% and that in Dangerous case is 100%.