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171.
Du-Ming Tsai Ming-Chun Chen Wei-Chen Li Wei-Yao Chiu 《Machine Vision and Applications》2012,23(5):869-886
In this paper, we propose a fast regularity measure for defect detection in non-textured and homogeneously textured surfaces, with specific emphasis on ill-defined subtle defects. A small neighborhood window of proper size is first chosen and they slide over the entire inspection image in a pixel-by-pixel basis. The regularity measure for each image patch enclosed in the window is then derived from the eigenvalues of the covariance matrix formed by the variance–covariance of the x- and y-coordinates with the pixel gray levels as the weights for all pixel points in the window. The two eigenvalues of the weighted covariance matrix will be approximately the same when the image patch contains only a homogeneous region, whereas the two eigenvalues will be relatively different if the image patch in the window contains a defect. The smaller eigenvalue of the covariance matrix is then used as the regularity measure. The integral image technique is introduced to the computation of the regularity measure so that it is invariant to the neighborhood window size. The proposed method uses only one single discrimination feature for defect detection. It avoids the use of complicated classifiers in a high-dimensional feature space, and requires no learning process from a set of defective and defect-free training samples. Experimental results on a variety of material surfaces found in industry, including textured images of plastic surfaces and leather and non-textured images of backside solar wafers and LCD backlight panels, have shown the effectiveness of the proposed regularity measure for surface defect detection. It is computationally very fast, and takes only 0.032 s for a 400 × 400 image on a Pentium 3.00?GHz personal computer. In a test set of 73 backside solar wafer images involving 53 defect-free and 20 defective samples, the proposed regularity measure can correctly identify all the test images. 相似文献
172.
A three-axis SOI accelerometer sensing with both in-plane and vertical comb electrodes 总被引:1,自引:0,他引:1
A three-axis capacitive accelerometer based on silicon-on-insulator is designed and fabricated. In the accelerometer, totally
eight groups of capacitors are compactly arranged around an octagonal proof mass. The four groups of capacitors along orthogonal
direction with in-plane comb electrodes detect XY acceleration, while the other four groups of capacitors along diagonal direction with vertical comb electrodes detect Z acceleration.
Measurements of in-plane and vertical motion by the respective in-plane and vertical comb electrodes enable direct detection
for all the three axes with differential capacitive sensing scheme. For the fabricated accelerometer in the size of 4 × 4 mm2, the capacitance sensitivities of in-plane and out-of-plane accelerometers are 145.3 and 9.1 fF/g, respectively. 相似文献
173.
Ta-Wen Kuan Hsin-Chun Tsai Jhing-Fa Wang Jia-Ching Wang Bo-Wei Chen Zong-You Lin 《Expert systems with applications》2012,39(10):9288-9296
Intelligent porch research is an important issue in smart home development; however, such a field was rarely investigated in the literature. This investigation proposes a new hybrid and dynamic fusion of multiple experts for the intelligent porch system. First, a new hybrid priority tree with decision fusion (HPTD-fusion) is proposed to eliminate the problems of tag-based authentication outdoors. The HPTD-fusion first verifies the vocal entrance code (VEC), and subsequently the remaining experts are performed in the cases of AND, OR or majority voting for decision fusion. Second, the post-mapping dynamic weighted fusion (PMDW-fusion) scheme is presented to adapt the indoor porch audio-visual environment. The PMDW-fusion dynamically assigns the higher weight to experts with higher performance, and then sums all participating experts for score fusion. The experimental results demonstrate that FRR and FAR can reach up to 0.18 and 0.19, respectively, when the system is tested in the outdoor environment. Furthermore, the indoor recognition accuracy can be increased to 86.1% using the proposed fusion scheme. The experiments have verified the effectiveness and feasibility of the proposed system. Restated, the contribution of this work is to develop a novel intelligent porch system incorporating a natural and unobtrusive method for identity recognition. The proposed system has been installed and tested in a real-world environment in the Technologies for Ubiquitous Computing and Humanity (TOUCH) Center at National Cheng Kung University. 相似文献
174.
The heterogeneous catalytic redox behaviour of NiS
x
deposited electrodes was investigated with and without benzyl alcohol in KOH solution using cyclic voltammetry and linear sweep voltammetry. The limiting current density for benzyl alcohol oxidation on a NiS
x
electrode was 22 times larger than that on a polished nickel electrode. The experimental results in galvanostatic electrolysis using fractional factorial design showed that the main and interaction effects of benzyl alcohol concentration, temperature, and OH– concentration are the key variables influencing the selectivity of benzaldehyde formation during electrolysis. 相似文献
175.
176.
This research focuses on the fabrication of glass fiber/epoxy nanocomposites containing organoclay as well as understanding the organoclay effect on the transverse compressive strength of nanocomposites. To demonstrate the organoclay effect, three different loadings of organoclay were dispersed, respectively, in the epoxy resin using a mechanical mixer followed by sonication. The corresponding glass/epoxy nanocomposites were produced by impregnating dry glass fiber with organoclay epoxy compound through a vacuum hand lay-up procedure. Unidirectional block specimens were employed for transverse compression tests on a hydraulic MTS machine. Experimental observations indicate that glass/epoxy nanocomposites containing organoclay exhibit higher transverse compressive strength than conventional composites. Furthermore, the failure mechanisms for all tested specimens were found to be fiber and matrix debonding. Therefore, results indicate that the increasing characteristic in transverse failure stress may be ascribed to the enhanced fiber/matrix adhesion modified by the organoclay. 相似文献
177.
Jeng-Han Tsai Wei-Chien Chen To-Po Wang Tian-Wei Huang Huei Wang 《Microwave and Wireless Components Letters, IEEE》2006,16(6):327-329
A miniature Q-band low noise amplifier (LNA) using 0.13-/spl mu/m standard mixed signal/radio frequency complementary metal-oxide-semiconductor (CMOS) technology is presented in this letter. This three-stage common source thin-film microstrip LNA achieves a peak gain of 20dB at 43GHz with a compact chip size of 0.525mm/sup 2/. The 3-dB frequency bandwidth ranges from 34 to 44GHz and the minimum noise figure is 6.3dB at 41GHz. The LNA outperforms all the reported commercial standard CMOS Q-band LNAs, with the highest gain, highest output IP3, and smallest chip size. 相似文献
178.
Fu S.-I. Cheng S.-Y. Chen T.-P. Lai P.-H. Tsai Y.-Y. Hung C.-W. Yen C.-H. Liu W.-C. 《Electron Devices, IEEE Transactions on》2006,53(11):2689-2695
A comprehensive study of emitter-ledge thickness of InGaP/GaAs heterojunction bipolar transistors (HBTs) has been undertaken. It is shown that the recombination rate and electron densities are drastically increased near the exposed base surface between the base contact and the emitter ledge. In contrast, the corresponding hole densities are decreased. If the emitter ledge is too thick, current will flow through the undepleted ledge, which increases the emitter-size effect. In contrast, if the emitter ledge is too thin, it may not effectively passivate the surface. Therefore, the thickness of the emitter ledge is a crucial issue and should be carefully considered. It is shown that, from simulated and experimental results, the optimum emitter-ledge thickness of InGaP/GaAs HBT is 100-200 Aring 相似文献
179.
Hung C.-W. Lin H.-L. Chen H.-I. Tsai Y.-Y. Lai P.-H. Fu S.-I Liu W.-C. 《Electron Device Letters, IEEE》2006,27(12):951-954
On the basis of a Pt/In0.52Al0.48As metal-semiconductor structure, a novel hydrogen sensor is fabricated and demonstrated. The studied Pt/In0.52Al0.48As Schottky diode-type hydrogen sensor exhibits significant sensing performance including high relative sensitivity ratio of about 2600% (under the 1% H2/air gas and VR=-0.5 V at 30 degC), large current variation of 310 muA (under the 1% H2/air gas and VR=-5 V at 200 degC), widespread reverse-voltage regime (0~-5 V), stable hydrogen-sensing current-voltage (I-V) curves, and fast transient response time of 1.5 s. The calculated Schottky barrier-height change and series-resistance variation, from the thermionic-emission model and Norde method, are 87.0 meV and 288 Omega, respectively (under the 1% H2/air gas at 30 degC). The hydrogen concentrations and operating temperatures tested in this letter are in the range of 15 ppm-1% H2/air and 30 degC-250 degC, respectively. Based on the excellent integration compatibility with InP-based electronic devices, the studied device provides the potentiality in high-performance sensor-array applications 相似文献
180.
PESOI: Process Embedded Service-Oriented Architecture 总被引:4,自引:0,他引:4
Wei-Tek Tsai Yinong Chen Chun Fan 《软件学报》2006,17(6):1470-1484
1 Introduction Service-Oriented Architecture (SOA) has received significant attention recently as major computer and software companies such as HP, IBM, Intel, Microsoft, and SAP, have all embraced SOA, as well as government agencies such as DoD (US depar… 相似文献