著者
本郷 節之 乾 敏郎 川人 光男
出版者
一般社団法人映像情報メディア学会
雑誌
テレビジョン学会技術報告 (ISSN:03864227)
巻号頁・発行日
vol.14, no.54, pp.1-6, 1990-10-23
被引用文献数
3

Illusions sometimes give us the keys to understand the mechanisms of the visual information processing. But, the mechanisms of the brightness illusions, for example the Mach band of the Craik-O'Brien effect, are not clear yet. In this paper, the role of the filling-in process on the brightness perception is explained. Its computational theory is discussed. And a neural network model of the filling-in process on the brightness perception is constructed based on the computational theory. Some properties of the Mach band and the Craik-O'Brien effect are simulated with the model, and its behavior is similar to some psychological experiment results.
著者
小倉 明夫 前田 富美恵 宮井 明 本郷 隆治
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.60, no.11, pp.1543-1549, 2004-11-20
被引用文献数
14

The contrast-to-noise ratio (CNR.) is often used to evaluate magnetic resonance images, because it has two components, contrast and SNR, and indicates the detectability of clinical lesions. Two methods (using a phantom and using clinical images) are employed to measure CNR. In addition, there are some methods of measurement that use clinical images. In this report, the accuracy of measurement and correlation for signal detectability were evaluated in four methods of measuring CNR using clinical images. The results indicated that the inter-tissue method using an air signal provided good accuracy and was consistent with signal detectability using observer performance. In addition, a small region of interest (ROI) was better suited as the target for CNR measurement using clinical images.
著者
本郷 仁志 山田 光穂
出版者
一般社団法人映像情報メディア学会
雑誌
テレビジョン学会技術報告 (ISSN:03864227)
巻号頁・発行日
vol.16, no.70, pp.7-12, 1992-10-26
被引用文献数
2

To examine how rapidly, and to what extent, humans obtain sufficient information for searching during fixation, we experimented with visual search by masking the subject's central vision at various onsets and sizes after he had fixated there. The subjects counted circles embedded in distractors. From the results, we learned that, in an area of 4.2 degrees, sufficient visual information could be acquired in 33 ms. The oculomotor control system was not affected by masking. The distribution of the fixation duration varied according to the onset of masking. suggesting that eye movements were quickened by the masking of central vision, and saccades occurred about 130 ms after at the onset of masking.
著者
本郷 道夫
雑誌
自律神経 = The Autonomic nervous system (ISSN:02889250)
巻号頁・発行日
vol.35, no.3, pp.339-341, 1998-06-15
被引用文献数
2
著者
山口 高康 青野 博 本郷 節之
出版者
一般社団法人電子情報通信学会
雑誌
電子情報通信学会技術研究報告. PRMU, パターン認識・メディア理解 (ISSN:09135685)
巻号頁・発行日
vol.104, no.448, pp.1-6, 2004-11-12
被引用文献数
8 6

In this paper, we discuss image representation methods for signboard discrimination based on images. First, characteristics of image-based signboard discrimination problem and requirements for the discriminator are extracted. Next, traditional image representation methods, e.g. a color histogram or a space frequency, and so on, and their advantages and/or disadvantages are outlined. And next, effectiveness for each representation is compared for the signboard discrimination problem with images, using k-nearest neighbor (k-NN) method which is one of the most simple discrimination methods. Finally, to improve faculties of the image representation from the view point of signboard discrimination, two means, i) for reduction of the background affection and ii) for use of the color information, are discussed based on the extracted characteristics and requirements.
著者
本郷 保二 道下 幸志
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society (ISSN:03854213)
巻号頁・発行日
vol.128, no.12, pp.1535-1542, 2008-12-01
被引用文献数
6 1

The overvoltage associated with direct lightning hits has been the important factor for the insulation design of a distribution line. In this paper, the sparkover rate of a medium-voltage line associated with direct lightning hits is investigated based on numerical calculations obtained by using EMTP and statistical analysis by taking account of the correlation between the peak value and the front duration of return-stroke current waveform. When the line is equipped with surge arresters at the interval of 100m in addition to the overhead ground wire, the sparkover rate associated with subsequent strokes is higher than that associated with first strokes. This demonstrates the importance of the study of current parameters for subsequent strokes.
著者
笹木 圭子 本郷 大 恒川 昌美
出版者
一般社団法人 資源・素材学会
雑誌
資源と素材 (ISSN:09161740)
巻号頁・発行日
vol.114, no.10, pp.709-713, 1998-08-25 (Released:1999-10-01)

Aragonite-type calcium carbonate was synthesized from calcined scallop shell using carbonates of orthorohombic structure (such as SrCO3) as seeds, by bubbling CO2 at ambient temperature. The products were examined by FTIR, SEM, EPMA, and XRD. The addition of SrCO3 increased aragonite content in the products, but BaCO3 and PbCO3 did not play the role of seed crystals due to the difference of their lattice parameters to those of aragonite, whereas lattice parameters of SrCO3 are the most similar to them. With increasing SrCO3 -addition, formation of aragonite was accelerated to a limit in the amount. Light calcium carbonate rich in aragonite was formed in agglegates consisting of needle-like crystals with large specific surface areas.