58 resultados para Vision Screening


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This paper presents a novel architecture of vision chip for fast traffic lane detection (FTLD). The architecture consists of a 32*32 SIMD processing element (PE) array processor and a dual-core RISC processor. The PE array processor performs low-level pixel-parallel image processing at high speed and outputs image features for high-level image processing without I/O bottleneck. The dual-core processor carries out high-level image processing. A parallel fast lane detection algorithm for this architecture is developed. The FPGA system with a CMOS image sensor is used to implement the architecture. Experiment results show that the system can perform the fast traffic lane detection at 50fps rate. It is much faster than previous works and has good robustness that can operate in various intensity of light. The novel architecture of vision chip is able to meet the demand of real-time lane departure warning system.

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This paper presents a novel CMOS color pixel with a 2D metal-grating structure for real-time vision chips. It consists of an N-well/P-substrate diode without salicide and 2D metal-grating layers on the diode. The periods of the 2D metal structure are controlled to realize color filtering. We implemented sixteen kinds of the pixels with the different metal-grating structures in a standard 0.18 mu m CMOS process. The measured results demonstrate that the N-well/P-substrate diode without salicide and with the 2D metal-grating structures can serve as the high speed RGB color active pixel sensor for real-time vision chips well.

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D-vision系统(这里"D"有"Divide Screen"和"Duplex-Vision"双重含义)是一类基于PC机群的多投影虚拟现实系统(或简称多投影系统).给出D-vision系统中双手6自由度力觉交互的实现过程:在客户端协同控制两个力觉交互设备Spidar-G(Space Interface for Artificial Reality withGrip)实现双手协作交互,其次构造一个基于UDP的Socket类完成客户端和绘制服务器节点之间的通讯,传递跟踪球的位置、方向等信息;然后,通过分布绘制实现在大屏幕上无缝显示.最后实验结果表明:在D-vision系统中双手6自由度力觉交互是一种自然直观的人机交互方式.

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A portable 3D laser scanning system has been designed and built for robot vision. By tilting the charge coupled device (CCD) plane of portable 3D scanning system according to the Scheimpflug condition, the depth-of-view is successfully extended from less than 40 to 100 mm. Based on the tilted camera model, the traditional two-step camera calibration method is modified by introducing the angle factor. Meanwhile, a novel segmental calibration approach, i.e., dividing the whole work range into two parts and calibrating, respectively, with corresponding system parameters, is proposed to effectively improve the measurement accuracy of the large depth-of-view 3D laser scanner. In the process of 3D reconstruction, different calibration parameters are used to transform the 2D coordinates into 3D coordinates according to the different positions of the image in the CCD plane, and the measurement accuracy of 60 mu m is obtained experimentally. Finally, the experiment of scanning a lamina by the large depth-of-view portable 3D laser scanner used by an industrial robot IRB 4400 is also employed to demonstrate the effectiveness and high measurement accuracy of our scanning system. (C) 2007 Elsevier Ltd. All rights reserved.

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This paper shows that waveguides induced by grey screening-photovoltaic solitons are always single mode for all intensity ratios, which are the ratio between the peak intensity of the soliton and the dark irradiance. It finds that the confined energy near the centre of the grey soliton and the propagation constant of the guided mode increase monotonically with increasing intensity ratio. On the other hand, when the soliton greyness increases, the confined energy near the centre of the grey soliton and the propagation constant of the guided mode reduce monotonically. When the bulk photovoltaic effect is neglected for short circuits, these waveguides become waveguides induced by grey screening solitons. When the external bias field is absent, these waveguides become waveguides induced by grey photovoltaic solitons.

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We investigate theoretically waveguides induced by screening-photovoltaic solitons in biased photorefractive-photovoltaic crystals. We show that the number of guided modes in a waveguide induced by a bright screening-photovoltaic soliton increases monotonically with the increasing intensity ratio of the soliton, which is the ratio between the peak intensity of the soliton and the dark irradiance. On the other hand, waveguides induced by dark screening-photovoltaic solitons are always single mode for all intensity ratios and the confined energy near the centre of a dark screening-photovoltaic soliton increases monotonically with the increasing intensity ratio. When the bulk photovoltaic effect is neglectable, these waveguides are those induced by screening solitons. When the external field is absent, these waveguides predict those induced by photovoltaic solitons.

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Secondary metabolites produced by water-blooming cyanobacteria in eutrophic waters include some potent hepatotoxins, These compounds also have tumour-promoting properties, attributable to their inhibition and activation of protein phosphatases and kinases respectively. The inhibitory effect of these toxins on protein phosphatases have been employed in a commonly used radiometric assay, involving the use of a P-32-labeled substrate, for the detection and quantitation of these compounds. This paper investigates and describes a colorimetric method in which the activity of protein phosphatase 2A is determined by measuring the rate of colour production from the release of yellow p-nitrophenol using p-nitrophenyl phosphate as the substrate. Results of this study suggest that the colorimetric protein phosphatase inhibition assay is a simple, inexpensive tool for screening substances that may have tumour-promoting characteristics in aquatic systems. The detection limit of the colorimetric method is comparable to the radiometric assay. (C) 1998 Elsevier Science Ltd. All rights reserved.

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枯草芽孢杆菌BJ1是一种在真菌病害防治中发挥重要作用的生防因子,为进一步提高它的抑菌能力,获得生防效果更好的高效菌种,利用不同能量和剂量的12C6+对生防菌BJ1进行了离子辐照处理。研究结果表明:离子辐照生防菌BJ1的最适宜剂量为200~400 Gy,传能线密度(LET)为60 keV/μm;突变菌株的抑菌能力比BJ1提高了2%~21%;不仅防病效果比BJ1提高了17.48%,而且对植物具有更好的促生长作用。