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我国煤矿自动化现状及发展趋势 总被引:2,自引:0,他引:2
根据先进的煤矿自动化产品的特点,分析了我国煤矿自动化产品存在的问题,指出了建立具有统一网络平台的煤矿综合自动化系统是我国煤矿自动化与信息化的发展趋势;介绍了我国煤矿综合自动化系统的现有基础及其在建设中主要涉及的方面,给出了基于工业以太网和基于现场总线的煤矿综合自动化系统的网络平台结构及特点,以及实施煤矿综合自动化系统需要注意的问题。 相似文献
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Annick Valibouze 《Journal of Symbolic Computation》2011,46(4):396-405
This article proposes an efficient and simple algebraic method of computation of a Gröbner basis generating the alternating galoisian ideal of a univariate separable polynomial. We named this method “the descent of the Vandermonde determinants”. 相似文献
157.
Tao LiuAuthor Vitae Boxiong WangAuthor Vitae 《Sensors and actuators. A, Physical》2011,171(2):186-190
Intersection technology plays a key role in long-distance horizontal directional drilling (HDD). Magnetic ranging technology is an effective way to realize the intersection. A three-dimensional magnetic field model suitable for the cylindrical magnet connected with drilling bit was established. New formulae of magnetic induction intensity were deduced from the fundamental formulae to suit to the new magnetic ranging method. Based on the new formulae, a curve fitting model was established to complete the ranging. The whole process is simple and effective. The result of the experiment proved the feasibility of the new method and the accuracy is high enough for HDD. 相似文献
158.
Yunjie ChenAuthor Vitae Jianwei ZhangAuthor VitaeArabinda MishraAuthor Vitae Jianwei YangAuthor Vitae 《Neurocomputing》2011,74(17):3520-3530
Intensity inhomogeneity causes considerable difficulty in the quantitative analysis of magnetic resonance (MR) images. Thus bias field estimation is a necessary pre-processing step before quantitative analysis of MR data. This paper presents a variational level set approach for bias correction and segmentation for images with intensity inhomogeneities. Our method is based on the observation that local intensity variations in relatively smaller regions are separable, despite the inseparability of the whole image. In the beginning we define a function for clustering the image pixels in a smaller neighborhood. The cluster centers in this objective function have a multiplicative factor that estimates the bias within the neighborhood. Generally the local intensity variations are described by the Gaussian distributions with different means and variances. In this work the objective functions are integrated over the entire domain with local Gaussian distribution of fitting energy, ultimately analyzing the data with a level set framework. Our method is able to capture bias of quite general profiles. Moreover, our model can also distinguish regions with similar intensity distribution with different variances. The proposed method has been rigorously validated with images acquired on variety of imaging modalities with promising results. 相似文献
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Carmen Serrano Author Vitae Author Vitae 《Pattern recognition》2009,42(6):1052-61
In this paper a method for detecting different patterns in dermoscopic images is presented. In order to diagnose a possible skin cancer, physicians assess the lesion based on different rules. While the most famous one is the ABCD rule (asymmetry, border, colour, diameter), the new tendency in dermatology is to classify the lesion performing a pattern analysis. Due to the colour textured appearance of these patterns, this paper presents a novel method based on Markov random field (MRF) extended for colour images that classifies images representing different dermatologic patterns. First, each image plane in L*a*b* colour space is modelled as a MRF following a finite symmetric conditional model (FSCM). Coupling of colour components is taken into account by supposing that features of the MRF in the three colour planes follow a multivariate Normal distribution. Performance is analysed in different colour spaces. The best classification rate is 86% on average. 相似文献