共查询到20条相似文献,搜索用时 15 毫秒
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Results are presented for theoretical research and modelling of a measuring channel for information measuring systems for
the volume of oil with a turbine oil discharge converter. The possibility of increasing accuracy is established. 相似文献
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Effect of image resolution on intensity based scene illumination classification using neural network
《成像科学杂志》2013,61(8):433-439
In this paper, a framework for testing scene illumination classification with different image resolutions is proposed. The testing aims to provide the researchers with valuable information about the effect of image resolution on scene illumination classification using a neural network. The experiment is done by extracting three types of features from the images. These three types consist of statistical features, physic based features and histogram based features. It has been demonstrated that scene illumination classification can be affected by changing the image resolution. Despite the popular belief that high resolution images lead to better results, scene illumination classification by the proposed method performed best using low resolution images. At the second part of discussion, the reason behind this phenomenon is mathematically analysed and explained. 相似文献
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This article presents a practical method that estimates illumination distribution from shadows using only a single image. The shadows are assumed to be cast on a textured, Lambertian surface by an object of known shape. Previous methods for illumination estimation from shadows usually require that the reflectance property of the surface on which shadows are cast be constant or uniform, or need an additional image to cancel out the effects of varying albedo of the textured surface on illumination estimation. But, our method deals with an estimation problem for which surface albedo information is not available. In this case, the estimation problem corresponds to an underdetermined one. We show that the combination of regularization by correlation and some user‐specified information can be a practical method for solving the underdetermined problem. In addition, as an optimization tool for solving the problem, we develop a constrained Non‐Negative Quadratic Programming (NNQP) technique into which not only regularization but also multiple linear constraints induced by user‐specified information are easily incorporated. We test and validate our method on both synthetic and real images and present some experimental results. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 143–154, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20047 相似文献
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Abstract The irradiance produced by an optical imaging system suffering from aberrations under broad-band illumination is analysed in the phase-space domain of the Wigner distribution function associated with a modified one-dimensional pupil aperture. To this end, a coordinate transformation is employed in such a way that the varying irradiance along different paths in the image space can be derived from different slices of the Wigner distribution function, which involve both the defocus distance and the dispersion properties of the optical system. The method is illustrated by comparing the axial irradiance distribution for different primary aberrations. Also, the irradiance along parabolic paths is obtained in order to analyse the coma effect. 相似文献
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G. N. Solopchenko 《Measurement Techniques》1997,40(11):1029-1037
A method for verification of error characteristics containing random components is proposed to be used in metrological trials
of measuring devices. This method does not require the knowledge of the prior distribution law of the random error component
but nevertheless assures the preassigned guarantees against erroneous decisions. It is based on R. A. Fisher's fiducial probabilities.
Translated from Izmeritel'naya Tekhnika, No. 11, pp. 3–8, November, 1997. 相似文献
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The results are given of an investigating of errors in measuring the parameters of short-range radiating stations in the near-field
zone, owing to the involvement of the scattering characteristics in measurements of the dimensions of receiving aperture antennae
and phased antenna arrays. It is shown that such errors are systematic in character, and, at high levels of antenna effective
scattering area, appreciably exceed phase errors arising from sphericity of the amplitude-phase front of the electromagnetic
wave. Methods are proposed for metering and reducing the scattering errors.
Translated from Izmeritel'naya Tekhnika, No. 5, pp. 56–58, May, 1995. 相似文献
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V. V. Makarov 《Measurement Techniques》1994,37(8):949-956
Two classes of amplitude-adaptation algorithms, steady random Gaussian measured signals, and measurement problems are considered: sampled and with subsequent restoration of the signal form. Expressions are derived for the errors of adaptive measurements in the case when the metrological characteristics of the components of the measuring channel are known. A method of determining the adaptation time and a numerical example are presented, as well as criteria of the quality of an adaptive measuring channel. The problem of making a rational choice of the algorithm is solved.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 56–59, August, 1994. 相似文献
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Translated from Izmeritel'naya Tekhnika, No. 1, pp. 31–32, January, 1991. 相似文献
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