Browsing by Author "HO, CT"

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A FAST ELLIPSE/CIRCLE DETECTOR USING GEOMETRIC SYMMETRY
(1995-01-01)
HO, CT
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CHEN, LH
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交大名義發表
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資訊工程學系
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National Chiao Tung University
Through the use of a global geometric symmetry, a fast ellipse/circle detector is proposed in this paper. Based on the geometric symmetry, the proposed method first locates candidates of ellipse and circle centers. In the meantime, according to these candidate centers, all feature points in an input image are grouped into several subimages. Then, for each subimage, by using geometric symmetry again, all ellipses and circles are obtained. The method significantly reduces the time required to evaluate all possible parameters without using edge direction information. Experimental results are given to show the correctness and effectiveness of the proposed method.
ALUMINA-CHROMIUM CARBIDE COMPOSITE THROUGH AN INTERNAL SYNTHESIS METHODS
(1992-11-01)
CHUANG, SC
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KUO, CT
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LEE, CS
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HO, CT
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LI, AK
In situ formation of chromium carbide parlicles, through a solid state reaction between Cr2O3 and SiC, for strengthening Al2O3 has been studied. Three kinds of chromium compound, Cr3Si, Cr3C2 and Cr7C3 and mullite were formed in the alumina matrix. The reaction behaviour during hot pressing depends on heating parameters such as temperature and atmosphere. In a vacuum environment, the Cr3Si particles formed first and was the dominant dispersed phase below 1550-degrees-C, while the Cr7C3 phase was only dominant above 1600-degrees-C. The Cr3C2 phase emerged briefly then diminished at temperature greater-than-or-equal-to 1500-degrees-C. In an argon environment, however, the Cr3C2 phase was the main product component at temperatures ranging from 1450-1550-degrees-C. The mullite phase formed concurrently through the diffusion Of SiO2 phase into the A12O3 matrix, which is a by-product from the reaction between Cr2O3 and SiC. Incorporating chromium carbide or silicide particles into the Al2O3 matrix induces a strengthening effect. However, only when the content of dispersed phases is low and is mainly of Cr3C2 particles, is the strengthening effect significant. For instance, the composite, containing 5 vol % chromium carbide and hot-pressed at 1500-degrees-C in argon, gives a flexural strength and fracture toughness up to 600 M Pa and 6.1 MPa m1/2, respectively.
BROADCASTING ON INCOMPLETE HYPERCUBES
(1993-11-01)
TIEN, JY
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HO, CT
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YANG, WP
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資訊工程學系
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Department of Computer Science
Incomplete hypercubes make the hypercubes more flexible on task allocation in large cubes, cost of manufacturing hardware, and hypercubes with faulty nodes. In this correspondence, we devise and analyze a broadcasting algorithm based on edge-disjoint spanning trees in an incomplete hypercube of 2n + 2k nodes, where 0 less-than-or-equal-to k less-than-or-equal-to n. The broadcasting algorithm is strictly optimal.
INSITU REACTED TIB2-REINFORCED ALUMINA
(1992-11-15)
CHUANG, SC
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KUO, CT
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HO, CT
;
LI, AK
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機械工程學系
In situ formation of TiB2 in Al2O3 matrix through the reaction of TiO2, boron and carbon has been studied. In hot-pressed samples, in addition to TiB2, TiC and Al2TiO5, were also found to be dispersed phases in Al2O3 matrix. However, in the case of pressureless-sintered samples, pure Al2O3/TiB2 composite with > 99% relative density can be obtained through a preheating step held at 1300-degrees-C for longer than 30 min and then sintering at a temperature above 1500-degrees-C. Pressureless-sintered composite containing 20 vol % TiB2 gives a flexural strength of 580 MPa and a fracture toughness of 7.2 MPa m1/2.