143 resultados para Extraction and purification


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快速图像特征提取算法是图像处理和计算机视觉领域的重要研究课题。在复杂背景下基于视频的自动目标识别与跟踪中,目标特征的快速准确提取是实现高概率自动目标识别的关键技术,目标特征的快速提取能简化待识别目标的表示,实现快速准确地识别出感兴趣的目标。在机器人视觉中,快速图像特征提取也有广泛的应用,如视觉里程计技术、机器人自主视觉导航技术等。本文根据视频监控和机器人视觉的实际需求,对此课题开展了研究,主要的研究成果包括如下内容: 1)为消除视频图像的噪声对特征点提取的影响,提出了一种新的基于图像统计信息消除椒盐噪声算法。该算法能在去除噪声同时保持图像的细节特征(边缘和角点等),并且具有较低的计算复杂度。 2)提出了基于4叉树和色彩迁移理论的光照常恒算法。该算法可对同一场景不同光照下的两幅图像进行光照校正。将一幅图像的亮度特征传递给另一幅图像,使目标图像具有与参照图像相似的亮度统计信息。通过亮度处理之后,两幅图像具有相似的光照背景,有助于后续的特征点检测。 3)提出了基于LBP的角点快速提取算法。该方法与目前流行Harris和SUSAN角点提取算法相比,具有复杂度低、实时性好、灰度伸缩不变性和旋转不变性等优点。 4)从透镜成像模型原理出发,推导出精确的景深计算公式,并将其和传统的景深计算公式进行了深入的比较和分析,最后从计算机视觉角度阐述了本文的景深计算公式的优点。 5)在上述算法研究和试验基础上,研发了森林烟火自动识别软件系统。在该系统中,上述提出的算法得到成功的应用。该软件系统已投入实际使用,实现了24小时全天候森林烟火自动监控和预警,同时也验证了文中所提算法的有效性。论文的最后一章进行了总结,并对今后的研究工作进行了展望。

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插件作业 (parts mating)是装配机器人的一项基本作业环节 .本文介绍了以双目立体视觉实现该作业的视觉导引方法 .该方法通过采用人机交互方式 ,借助于人的智慧 ,提高了图像特征提取和匹配的准确性和可靠性、可直观准确地给出插件作业的动作参数 ,克服了自动视觉计算复杂、鲁棒性差的缺点 ,适用于机器人遥操作作业 .实验表明 ,基于人机交互的机器人插件作业在立体视觉导引下是完全可行的

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随着工业技术的发展,现代设备的生产方式更加趋于自动化和连续化。变速箱作为机械设备中最常见的传动方式之一,在各种设备中有着广泛的用途。因此,对变速箱进行状态监测及故障诊断意义重大,不仅可缩短维修时间、降低维修成本,还可提高诊断准确性和维修质量,创造可观经济效益。 汽车生产自动化程度的日渐提高以及市场竞争的日趋激烈化,要求汽车制造公司在高产量的同时保证产品质量的可靠,这样对机械故障诊断的准确性和快速性提出了更高的要求。变速箱作为汽车动力总成的重要部分,其质量对整车性能有着极大的影响。因此,快速准确的对变速箱进行在线检测和故障诊断是保证汽车质量的重要途径。 变速箱故障诊断技术是近年来的研究热点。当变速箱发生故障时,其故障信号往往包含着大量的冲击成分,由于变速箱内部结构比较复杂,所以其振动信号同时含有很强的噪声成分,如何有效的消除噪声,提取到故障信号是变速箱故障诊断的前提和基础。 本论文围绕小波变换和小波包变换在变速箱故障诊断中的应用进行了理论研究和实验验证,将小波分析这一时频分析方法应用到变速箱故障诊断领域。结合自适应小波变换滤波与经典的小波阈值去噪算法,提出了一种基于小波的双层滤波去噪算法,它可以有效的消除变速箱故障信号中的噪声;对去噪后的故障信号进行重采样处理,以便消除由于转速和采样频率的改变对小波包频带能量特征提取的影响;然后,将重采样后的信号进行了小波包分解。最后,小波包频带能量序列被提取作为故障特征向量,以便进行故障诊断。 实验结果表明,本文提出的基于小波的双层滤波去噪算法相对于传统的小波阈值去噪算法,去噪效果更优;相对于改变尺度因子a与小波形状控制参数的k的自适应小波变换滤波算法,计算量大大减小。重采样信号处理可以较好的消除转速和采样频率对故障特征向量提取的影响。因此,以小波包分解频带能量序列作为故障特征向量能较好的表征不同的故障。

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Prediction of Carbonate Reservoir Based on the Elastic Parameter Analysis Zhang Guangzhi (Solid Geophysics) Directed by Professor Liu Hong Abstract With the exploration and development of Puguang Oilfield, oil-gas exploration of carbonate rock in China has shown good prospects. Research on earthquake prediction methods for carbonate reservoir becomes the key of oil and gas exploration. Starting with analysis of geological characteristics of carbonate rock, prestack AVO inversion method, prestack elastic impedance inversion and parameter calculation method and seismic attribute extraction and optimization method were studied based on the analysis of rock physics in this work. First, variation characteristic and law of carbonate rock reservoir parameters were studied based on experimental data of rock physics, log data, analysis assay data, mud logging data and seismic data, so as to lay a foundation for the further reservoir identification and description. Then, the structure, type and propagation law of seismic wave field were analyzed through seismic forward modeling of the reservoir, and contact between information from log and geology data with elastic parameters, such as compressional wave and shear wave velocity and density were established, so as to provide a standard for reservoir identification and hydrocarbon detection using seismic reflection characteristics of the research area. Starting with the general concept of inverse problem, through analysis of Zoeppritz equation, three kinds of pre-stack inversion methods were derived and analyzed in detail, the AVO 3-parameter inversion based on Bayesian theory, the prestack AVO waveform inversion method and the simultaneous inversion method, based on the statistical hypothesis of inversion parameters and observation data and the Gauss distribution assumption of noise. The three methods were validated by model data and real data. Then, the elastic wave impedance inversion method of carbonate reservoir was investigated and the method of elastic parameter extraction from elastic impedance data was put forward. Based on the analysis of conventional methods of seismic attribute extraction and optimization, the time-frequency attributes and the wavelet attributes with time and amplitude feature were presented, and the prestack seismic attribute calculation method which can characterize the reservoir rock and fluid characteristic was presented. And the optimization of seismic attribute using the nonlinear KPCA method was also put forward. A series of seismic prediction technologies for carbonate reservoir were presented based on analysis of rock physics and seismic forward simulation technology. Practical application of these technologies was implemented in A oil field of Southern China and good effect has been achieved. Key words: carbonate rock; reservoir prediction; rock physics, prestack seismic inversion; seismic attribute

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The Puziwan gold deposit is located at the northern boundary of the North China platform where there are very favorable ore-forming conditions. The deposit is a medium-sized gold deposit associated with silver and copper polymetallic minerallization which were closely related to cryptoexplosive processes and fluidization and underwent multi-epoch superposition of mineralization. The mineralization consists of cryptoexplosive breccia-type, fluidizing-type, porphyry-type, quartz vein-type, etc. The ore-controlling law of ore-bearing brecciated zone is systematically studied in the paper. The shape, scale and attitude of ore bodies are dominat in the upper, the ore bodies of fluidizing breccia-type are dominant in the upper and the middle part, the porphyry-type ore bodies are dominant in the bottom. The quartz vein-type ore bodies are impenetrated in all the brecciated zone. The metallogenic epoch of Puziwan gold deposit is collated and stipulated. The Rb-Sr isochron age of quartz porphyry (wall rock) is 233 Ma, refering to the Ar-Ar age of gold-bearing quartz, excluded the former conclusion that the so-called metallogenic epoch (245.9Ma) is in Indosinian epoch. The nonage metallogenic age of Buziwan gold deposit shoule be in the Yanshanian epoch (142.5Ma). By applying the sub-specimen sampling technique, the Rb-Sr isochron age of gold-bearing pyrites in late mineralization epoch is dated to be 64 Ma. In conclusion, the metallogenetic epoch of Puziwan gold deposit is in late Yanshanian-early Himalayan epoch. On the above basis, the metallogenic model of the "train type" and new texture model of ore deposit are established. by applying the methods of geology, shallow seismic exploration, remote sensing, partial geochemical extraction and the study of inclusions in the late granite porphyry, the author has made the metallogenic progosis in the depth and the prephery of Puziwan gold deposit and eight prospecting targets are proposed.

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With the progress of prospecting, the need for the discovery of blind ore deposits become more and more urgent. To study and find out the method and technology for the discovery of blind and buried ores is now a priority task. New geochemical methods are key technology to discover blind ores. Information of mobile components related to blind ores were extracted using this new methods. These methods were tested and applied based on element' s mobile components migrating and enriched in geophysical-geochemical process. Several kinds of partial extraction techniques have tested based on element' s occurrence in hypergenic zone. Middle-large scale geochemical methods for exploration in forest and swamp have been tested. A serious of methods were tested and applied effetely about evaluation of regional geochemical anomaly, 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system instead of the normal net. 1. Element related with ores can be mobiled to migrate upwards and be absorpted by surface soil. These abnomal components can be concentrated by natural or artificial methods. These trace metalic ions partially exist in dissovlvable ion forms of active state, and partially have been absorbed by Fe-Mn oxide, soil and organic matter in the soil so that a series of reaction such as complex reaction have take place. Employing various partial extraction techniques, metallic ions related with the phase of the blind ores can be extracted, such as the technique of organic complex extraction, Fe-Mn oxide extraction and the extraction technique of metallic ions of various absorption phases. 2.1:200000 regional geochemical evaluation anomaly methods: Advantageous ore-forming areas were selected firstly. Center, concentration, morphological feature, belt of anomaly were choosed then. Geological and geochemical anomalies were combined. And geological and geochemical background information were restrained. Xilekuduke area in Fuyun sheet , Zhaheba area in Qiakuerte sheet, the west-north part in Ertai sheet and Hongshanzui anomaly in Daqiao sheet were selected as target areas, in Alertai, in the north of Xinjiang. in Xilekuduke area, 1:25000 soil geochemical methods sampling based on the net in dendritic water system was carried out. Cu anomaly and copper mineralization were determined in the center area. Au , Cu anomalies and high polarization anomaly were determined in the south part. Prospecting by primary halo and organic complex extraction were used to prognosis blind ore in widely rang outcrop of bedrock. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system were used in transported overburden outside of mining area. Shallow seismic method and primary halo found a new blind orebody in mining area. A mineralization site was fou and outside of Puziwan gold mine, in the north of Shanxi province. Developing middle-large scale geochemical exploration method is a key technique based 1:200000 regional geochemical exploration. Some conditions were tested as Sampling density , distribution sites of sample, grain size of sample and occurrence of element for exploration. 1:50000 exploration method was advanced to sample clast sediment supplement clast sediment in valley. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system was applied to sample residual material in A or C horizon. 1:2000 primary or soil halo methods used to check anomalies and determine mineralization. Daliang gold mineralization in the northern Moerdaoga was found appling these methods. Thermomagnetic method was tested in miniqi copper-polymetallic ore. Process methods such as grain size of sample, heated temperature, magnetic separating technique were tested. A suite of Thermomagnetic geochemical method was formed. This method was applied in Xiangshan Cu~Ni deposit which is cover by clast or Gobi in the eastern Xinjiang. Element's content and contrast of anomaly with Thermomagnetic geochemical method were higher than soil anomaly. Susceptibility after samples were heated could be as a assessment conference for anomaly. In some sectors thermo-magnetic Cu, Ni, Ti anomalious were found outside deposits area. There were strong anomal ies response up ore tested by several kind of partial extraction methods include Thermomagnetic, enzyme leach and other partial extractions in Kalatongke Cu-Ni deposit in hungriness area in the northern of Xinjiang. Element's anomalies of meobile were mainly in Fe-Mn oxide and salt. A Copper mineralization site in Xilekuduke anomaly area had been determined. A blind ore was foung by shallow seismic and geochemical method and a mineralization site was found outside this mining area in Puziwan gold deposit in shanxi province. A Gold mineralization site was found by 1:50000 geochemical exploration in Daliang, Inner Mongolia.

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The synthesis of NaA zeolite membrane on a porous alpha -Al2O3 support by microwave heating (MH) was investigated. The formation of a NaA zeolite membrane was drastically promoted by MH. The synthesis time was reduced from 3 h for conventional heating (CH) to 15 min for MH. Surface seeding cannot only promote the formation of NaA zeolite on the support, but also inhibit the transformation of NaA zeolite into other types of zeolites. The thickness of the NaA zeolite membrane synthesized by MH was about 4 mum, thinner than that of NaA zeolite membrane synthesized by CH. The permeance of NaA zeolite membrane synthesized by MH was four times higher than that of the NaA zeolite membrane synthesized by CH, while their permselectivities were comparable. Multi-stage synthesis resulted in the transformation of NaA zeolite into other types of zeolites, and the perfection of the as-synthesized membrane decreased.

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A novel lower critical solution temperature (LCST) membrane forming system containing cellulose acetate (CA)/poly (vinyl pyrrolidone) (PVP 3 60K)/N-methyl-2-pyrrolidone (NMP)/1,2-propanediol with a weight ratio of 24.0:5.0:62.6:8.4 had been developed. CA hollow fiber ultrafiltration (UF) membranes were fabricated using the dry-wet spinning technique. The fibers were post-treated with a 200 mg/L hypochlorite solution over a period of 6 It at pH 7. The experimental results showed that water flux of a membrane decreased while retention increased with increasing CA concentration in a dope. It was concluded that the membrane pore size decreased with increasing CA concentration. The membrane fouling tendency for BSA was 3 times higher than that for PVP 24K. (C) 2004 Elsevier B.V. All rights reserved.