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, 1 号
選択された号の論文の26件中1~26を表示しています
特集:スマート社会を支える電子回路技術
巻頭言
特集論文
<電気回路・電子回路>
論文
<情報通信工学>
  • 小川 猛志, 小田部 悟士, 西沢 秀樹, 中村 秀文, 柴田 高穂
    2014 年 134 巻 1 号 p. 15-27
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    To construct future M2M networks economically, wide-range wireless cells with a radius of more than 1 km are proposed to be applied to the networks and the number of accommodatied terminals are estimated to be more than the population(1)-(3). The networks are expected to accommodate socially important services such as telemetering and disaster sensing. We are proposing that the minimum data packet rate shall be assured to the terminal groups used for such important services even if all terminals used for other services have data packets to send and keep retrying sending random access (RA) messages(4)(5). However, no studies have been done on controlling data packet rate as a terminal group under such requirements, and it is difficult to distinguish between collision of RA messages and idle signals, so it is also difficult to control RA message traffic. We propose here a fair congestion control method for terminal groups adaptable to the field wireless enviroment. This method distinguishes between RA collisions and idle signals using media access control (MAC) layer information and also enables RA message traffic and data packet traffic to be controlled unaffected by wireless error rate under variable bit rate. The results of a simulated evaluation are presented.
<生体医工学・福祉工学>
  • 有馬 正浩, 佐藤 隆幸, 渡部 泰明
    2014 年 134 巻 1 号 p. 28-34
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    Measurement of blood viscosity in human body is a very important subject for preventing diabetes mellitus. The blood viscosity is strongly correlated with an aggregation phenomenon of red blood cell. Some noninvasive method for estimation of the blood viscosity based on ultrasonic spectroscopy has been proposed. In the studies, substitution experiments using particles with large diameter has been generally performed, because a control of aggregation size is very difficult. This study is aimed at assessing the validity of the substitution experiments and proposing a compensation technique for the substitution experiments.
  • 高橋 真悟, 児玉 直樹, 小杉 尚子, 竹内 裕之
    2014 年 134 巻 1 号 p. 35-40
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    The category fluency task has become one of the most important measurement tools of the brain's function. In this study we have used a near-infrared spectroscopy to examine the prefrontal blood flow of the brain by performing a category fluency task function test to determine if this method can be used to diagnose dementia in the early stages.
    We examined 21 healthy volunteer students (age 21.0±1.4, 11 males, 10 females) and 50 patients with dementia (age 83.3±6.7, 12 male, 38 female, Mini Mental State: 0-22). The category fluency task required the users to create nouns belonging to the category of vegetables. Our results have shown that healthy volunteer students show an increase in the blood flow during the category fluency task while those with dementia patients did not show any relevant increase of blood flow while performing the same task. The results obtained suggest that the combination of the category fluency task and a near-infrared spectroscopy could be used as one more tool in the diagnosis of dementia.
  • 松村 健太, 吉元 健史, 山越 健弘, 小川 充洋, 山越 憲一
    2014 年 134 巻 1 号 p. 41-48
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    Transthoracic admittance cardiography is a simple and non-invasive method for monitoring cardiac kinetic function. However, its application is relatively limited because few portable devices are available. We have therefore developed a new portable transthoracic admittance cardiograph and its experimental validation of performance has been made in this study. We measured cardiac kinetic function, including heart rate, pre-ejection period, left ventricular ejection period, stroke volume, and cardiac output, in 10 healthy adult male subjects at rest and during exercise using a conventional desktop device as a reference and a newly developed portable device. As a result, high correlations between the desktop and the portable devices were observed in all indices (all rs > .83, all ps < .001). In addition, despite a simple case study, 24-hour continuous ambulatory measurement in a normal daily life using this portable device was confirmed. These results clearly demonstrate the validity of performance and the practicability of this device.
<システム・計測・制御>
<知能,ロボティクス>
  • 綿田 将悟, 大林 正直, 呉本 尭, 小林 邦和, 間普 真吾
    2014 年 134 巻 1 号 p. 85-93
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    In this paper, we propose a new decision making system of autonomous mobile robots based on a Markovian emotional model. In the proposed method, it is possible to build a method of determining behavior along the task by optimizing system parameters automatically. In addition, we propose a method for self-organization of a nonlinear transformation that makes it possible to convert input stimuli to internal parameters properly using a neural network. The effectiveness of the proposed method is verified through simulations of identifying unknown environments by evaluating the exploration time under five different test environments. These results showed that the automatic construction of the decision making system was performed, and valid action decisions were made effectively.
<メディア情報,ユーザ・インタフェース>
  • 小野 雄一, 石原 学, 山城 光雄
    2014 年 134 巻 1 号 p. 94-101
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    This paper is concerned with evaluation on the participants' use of the two multimedia distributing systems; PC-based podcasting and mobile-based distribution. We carried out two experiments in this paper; (i) evaluation of user's impression on the use of these distribution systems, and (ii) the relationship between download time and users' frustration caused by it. The results of students' questionnaire research revealed that there is a statistic significance between these two systems and that mobile-based podcasting was observed to have more salient factors concerning operability like “easy to operate” and “friendliness”, regardless of the difficulty of contents. Moreover, the comparative study on the download time between these two systems demonstrated that users were not feeling less comfortable for downloading materials to mobile devices, although mobiles took longer time to download materials than PC. These results lead us to interesting implications that mobile devices will have a great possibility to change learning environment because they will play an important role in the so-called “blended instruction” classroom environment applying to a traditional classroom setting in the near future.
  • 原 健太, 堀 磨伊也, 武村 紀子, 岩井 儀雄, 佐藤 宏介
    2014 年 134 巻 1 号 p. 102-111
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    We propose a method for constructing an interpersonal interaction system using a real image-based avatar. Human-computer interaction is important when we communicate with computers. As a medium of an interpersonal interaction, communication robots are used commonly in the real world and CG avatar is used in the virtual world. On behalf of the communication robots, android robots that have a similar appearance to an actual person can effectively transfer the human presence. On the other hand, CG avatar has advantages of a cost and installation space as compared to communication robots. When we use a CG avatar for a communication, it is important to increase the reality of a speaker. In this paper, we construct a prototype of an interpersonal interaction system using a real image-based avatar. By generating the avatar from captured images, we can have a high realistic sensation similar to the interpersonal communication system such as a video conference system. In the proposed method, additionally, the movement of the avatar is smoothed by generating interpolated images. The interpolated images are generated by approximating avatar's each body part as an ellipsoid, using user's posture information. To verify the validity of the system, we have conducted the experiments of subjective evaluation.
<音声画像処理・認識>
  • 萩原 良信, 野澤 満明, 崔 龍雲, 渡辺 一弘
    2014 年 134 巻 1 号 p. 112-120
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    In this paper, we propose a novel indoor human navigation system by applying view-based navigation to a smartphone. Indoor human navigation systems should conventionally need to install positioning infrastructures in buildings. To solve this problem, we focus on the view-based navigation developed as an indoor positioning method for mobile robots. This method has the following two features. One is able to identify the position of a user by processing images obtained from a monocular camera. The other is profitable in the processing cost because the process for position identification can be realized by a simple image matching algorithm. By using these two features, we will show that a human navigation can be implemented on a smartphone without installing special infrastructures. For applying the view-based navigation to a smartphone, we optimize an image matching algorithm and we also visualize the positional information obtained by the image matching. In the experiments of human navigation in actual indoor environments like a corridor, we confirmed that the proposed system is capable of accomplishing the indoor human navigation on a smart phone.
  • 野村 松信, 鈴木 拓真, 景山 陽一, 石沢 千佳子, 西田 眞
    2014 年 134 巻 1 号 p. 121-130
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    The smart phones, tablet terminals and mobile phones with built-in cameras are today very popular because of their ease of use. It is important for image processors to be able identify a signboard in an image and extract the character sequence. Techniques for extracting a character sequence from a signboard can combined with various other systems to realize a diverse range of services. When utilization of the system is assumed, it is necessary to consider improvement in the extraction accuracy of a character string domain, and improvement in the speed of the processing. Therefore, this paper proposes an algorithm for extracting character sequence from signboards on the basis of scene image features. In order to improve processing speed and accuracy, the information about the background color of the signboard obtained by cooperation with the car-navigation system etc. was also utilized. In the experiment conducted for 319 color signboards, the proposed method detected 313 signboards (98.12%), and for 569 monochrome signboards, the proposed method detected 513 signboards (90.16%). Moreover, the average processing time of the proposed method was about 0.47 seconds for a color signboard, and was about 0.95 seconds for a monochrome signboard. The experimental results revealed that the proposed method was able to accurately extract the different type of character string on signboard.
  • 中辻 秀人
    2014 年 134 巻 1 号 p. 131-137
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    In recent years, in the Fourier transform, the analytical method in which the length of the window for frequency can be arbitrarily determined was proposed by authors. Here, in the case that the length of a window is in inverse proportion to frequency, this becomes the same function as elasticity of the mother wavelet of Wavelet transform. In this analytical method, by using inner product between a sine wave or a cosine wave and a signal, the signal decomposes into many components which have each frequency. Furthermore calculating spectrum and reconstructing waveform from these decomposition waves were shown. Until now, a sine wave and a cosine wave have used independently as the cutting out wave. In this paper, In order to improve the approximation accuracy of the reconstruction wave, using the cutting out wave which combined a sine wave and a cosine wave is shown. In order to express the grade of approximation of a reconstruction wave and a signal waveform quantitatively, the degree of coincidence of both waveforms is introduced. In the example of numerical analysis, by using Japanese vocal sound /sa/, it is shown that the degree of approximation of the reconstruction wave to a signal waveform improves.
<情報システム,エレクトロニック・コマース>
  • 井上 和重, 青木 真吾, 福岡 憲治, 辻 洋
    2014 年 134 巻 1 号 p. 138-147
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    Data Envelopment Analysis (DEA) is one of evaluation methods and enables analysts to evaluate efficiencies of Decision Making Units (DMUs) with multiple input and output items. While DMUs were evaluated only in terms of efficiency, analysts cannot evaluate how efficient combinations of input and output items are. In order to evaluate the efficiencies of the combinations, we propose a method on the basis of DEA for evaluating structure of efficiency about input and output items based on conventional hierarchical approach. The proposed method is composed of four steps. In Step 1, dividing dataset, we construct a hierarchical structure. In Step 2, efficiency values are calculated for each divided dataset. In Step 3, nodes are integrated and visualized in Step 4. From visualized figure, analysts can evaluate characteristics of DMU structurally and find subsequent efficient items and key items which improve efficiency if this item is added to other items. A numerical example with the dataset of 2010 Quality of Life Index (thirty five DMUs, one input and five output items) is used to illustrate the features of the proposed method.
<情報処理・ソフトウェア>
  • 一ノ坪 剛生, 中村 優, 佐賀 亮介, 辻 洋
    2014 年 134 巻 1 号 p. 148-155
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    To make criteria for the activities of offshore software development, this paper proposes visualization technique for organization status. Basic promise under this research is that there are twelve capabilities and each capability has five levels. At first this paper introduces a knowledge management system, called SPICE with visualization functions. The function includes individual's growth path, group's growth path and dependency structure. Then, explaining the application domain on offshore software development, this paper describes experimental analysis and their visualization. The future perspective is also examined in detail.
  • 今村 誠, 竹内 丈志, 北上 眞二, 菅野 幹人, 撫中 達司
    2014 年 134 巻 1 号 p. 156-167
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    In facility management for plants and buildings, needs of facility diagnosis for saving energy or facility management cost by analyzing time series data from sensors of equipments in facilities have been increasing. In this paper, we propose a relation-based query language TPQL (Trend Pattern Query Language) for expressing constraints in time series data for anomaly detection in facilities and implemented an anomaly detection system based on TPQL. The features of TPQL are the following. (1) TPQL introduces a convolution operator into SQL (Structured Query Language) in order to describe contextual anomaly conditions over window sequences such as duration constraint and hunting constraint. (2) TPQL introduces time-interval based join into SQL in order to join time series data with different sampling rates. The anomaly detection system consists of a TPQL-interpreter as a top-level engine, relational database as an SQL engine, a key-value store database as a large data storage and configure management information to represent target signals for diagnosis and threshold values for anomaly detection. We evaluate that the system has enough expression ability to describe domain dependent anomaly detection conditions with TPQL over sliding windows and the sufficient processing speed required by the real applications.
  • 大塚 孝信, Deyue Deng, 伊藤 孝行
    2014 年 134 巻 1 号 p. 168-175
    発行日: 2014/01/01
    公開日: 2014/01/01
    ジャーナル フリー
    In recent years, young people are increasingly using internet. However, problem of received information to adversely affect the young people. Therefore, we propose a method to automatically classify to harmful sentences. Recently research on the information filtering have been improved the performance of the filter by introducing the co-occurrence information. Extended by two words co-occurrence information, which is commonly studied in this study we have created a training data using the co-occurrence information with three words. However, compared with the words two co-occurrence information processing time becomes a problem is increased the amount of training data. In addition, we have found that noise is caused by increase the co-occurrences, exceeds the number of double-precision floating-point calculation. We realized the processing speed by implementing a text filtering system with three-word co-occurrence using a Bayesian filter, to parallelize fast MyISAM database. In addition, by removing the noise caused by the increase in the number of co-occurrence BigDecimal, We realized the high F value.
 
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