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31.
Chen-Tsung Kuo Author Vitae 《Pattern recognition》2007,40(2):742-755
Three dimensional models play an important role in many applications; the problem is how to select the appropriate models from a 3D database rapidly and accurately. In recent years, a variety of shape representations, statistical methods, and geometric algorithms have been proposed for matching 3D shapes or models. In this paper, we propose a 3D shape representation scheme based on a combination of principal plane analysis and dynamic programming. The proposed 3D shape representation scheme consists of three steps. First, a 3D model is transformed into a 2D image by projecting the vertices of the model onto its principal plane. Second, the convex hall of the 2D shape of the model is further segmented into multiple disjoint triangles using dynamic programming. Finally, for each triangle, a projection score histogram and moments are extracted as the feature vectors for similarity searching. Experimental results showed the robustness of the proposed scheme, which resists translation, rotation, scaling, noise, and destructive attacks. The proposed 3D model retrieval method performs fairly well in retrieving models having similar characteristics from a database of 3D models. 相似文献
32.
Tetrahedrally close-packed structures with juxtaposed pentagonal antiprisms, such as the μ, C14 Laves and the newly found C phases, were studied by means of HREM and SAD. It was found that each bright spot in the structural image corresponds to an antiprism. Differently oriented domains of these phases intergrow frequently with a fairly good match at the interphase boundary. All diffraction patterns of these phases show a fivefold distribution of spot-pairs, and it is shown that this fivefold symmetry comes from the pentagons and spot-pairs from two pentagonal prisms superposed in antisymmetrical positions. 相似文献
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35.
Kuo R. J. Chang C. K. Nguyen Thi Phuong Quyen Liao T. W. 《Knowledge and Information Systems》2021,63(7):1935-1959
Knowledge and Information Systems - With the advance of information technology, many fields have begun using data clustering to reveal data structures and obtain useful information. Most of the... 相似文献
36.
Shih-Ying Lin Shi-Jinn Horng Tzong-Wann Kao Chin-Shyurng Fahn Deng-Kui Huang Ray-Shine Run Yuh-Rau Wang I.-Hong Kuo 《Applied Soft Computing》2012,12(9):2840-2845
A particle swarm optimization (PSO) algorithm combined with the random-key (RK) encoding scheme (named as PSORK) for solving a bi-objective personnel assignment problem (BOPAP) is presented. The main contribution of this work is to improve the f1_f2 heuristic algorithm which was proposed by Huang et al. [3]. The objective of the f1_f2 heuristic algorithm is to get a satisfaction level (SL) value which is satisfied to the bi-objective values f1, and f2 for the personnel assignment problem. In this paper, PSORK algorithm searches the solution of BOPAP space thoroughly. The experimental results show that the solution quality of BOPAP based on the proposed method is far better than that of the f1_f2 heuristic algorithm. 相似文献
37.
Ming-Yen Hsiao Ya-Wen Wu Wen-Shiang Chen Yu-Ling Lin Po-Ling Kuo Chueh-Hung Wu 《International journal of molecular sciences》2021,22(7)
Entrapment neuropathy (EN) is a prevalent and debilitative condition caused by a complex pathogenesis that involves a chronic compression–edema–ischemia cascade and perineural adhesion that results in excessive shear stress during motion. Despite decades of research, an easily accessible and surgery-free animal model mimicking the mixed etiology is currently lacking, thus limiting our understanding of the disease and the development of effective therapies. In this proof-of-concept study, we used ultrasound-guided perineural injection of a methoxy poly(ethylene glycol)-b-Poly(lactide-co-glycoilide) carboxylic acid (mPEG-PLGA-BOX) hydrogel near the rat’s sciatic nerve to induce EN, as confirmed sonographically, electrophysiologically, and histologically. The nerve that was injected with hydrogel appeared unevenly contoured and swollen proximally with slowed nerve conduction velocities across the injected segments, thus showing the compressive features of EN. Histology showed perineural cellular infiltration, deposition of irregular collagen fibers, and a possible early demyelination process, thus indicating the existence of adhesions. The novel method provides a surgery-free and cost-effective way to establish a small-animal model of EN that has mixed compression and adhesion features, thus facilitating the additional elucidation of the pathophysiology of EN and the search for promising treatments. 相似文献
38.
Flexible memory devices are one of the most crucial elements in the wearable electronics. In this work, polyimides (PIs)-based flexible resistive memory devices with an excellent thermal and mechanical durability are demonstrated. Four kinds of functional PIs are derived from the heterocyclic diamines including 2,6-diaminodibenzo-p-dioxin (OODA) and 2,6-diaminothianthrene, and dianhydrides including 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride. PI with diamine of OODA and dianhydride of 6FDA (PI(OODA_6FDA)) possesses outstanding thermal and mechanical properties with a high glass transition temperature of 352 °C, a low coefficient of thermal expansion of 28.1 ppm K−1, and a high elongation at break of 10%. In addition, PI(OODA_6FDA)-based memory shows write-once-read-many behavior with a high on/off current ratio of 106 and a stable data retention, attributed to the donor–acceptor charge transfer between the polymer chains. The retained current levels at a low resistive state can be observed even with thermal treatment at 200 °C for 24 h or 1000 times cyclic bending at a bending radius of 5 mm. These results demonstrate the potential of heterocyclic PIs for flexible resistive memory. 相似文献
39.
PHASES IN HIGH ALLOY STEELS AND SUPERALLOYS 总被引:1,自引:0,他引:1
<正> 高温合金一般是指以铁、镍或钴形成的面心立方基体(γ)为基的在较高温度下使用的合金,有些合金靠碳化物强化,有些合金靠铝、钛、铌等与镍生成的中间相(γ′或γ″)强化。此外,还要加入一定数量的钼或钨强化固溶体γ,加入微量的硼或锆强化晶界,加入较多的铬以增强合金的抗氧化能力。由此可见,高温合金中的合金元素,无论从种类或数量上来看,都要比合金钢中复杂得多。但是,在奥氏体不锈耐热钢与铁基高温合金之间并无明显的界限,实际上铁基高温合金就是在镍铬不锈耐热钢中不断提高镍的含量和增添新的合金元素而发展出来的。因此,在讨论高温合金中的相时,我们把铬镍不锈耐热钢也包括在内。 相似文献
40.
Chih-Wei Chang Chun-Pao Kuo 《International Journal of Machine Tools and Manufacture》2007,47(3-4):452-461
Laser-assisted machining (LAM), an alternative method of fabricating difficult-to-machine materials, uses primarily laser power to heat the local area (without necessarily evaporating or melting any material) before the material is removed. It not only efficiently reduces the cutting force during the manufacturing process but also improves the machining characteristics and geography with regard to difficult-to-machine materials, especially structural ceramics.This study on the application of laser-assisted machining to Al2O3 ceramics examines the measurements of cutting force and workpiece surface temperature as well as surface integrity and tool wear. Specifically, it uses the lattice Boltzmann method (LBM) to calculate the temperature distribution inside the ceramic workpiece during the LAM process and ensure that the laser energy causes no subsurface damage. The experimental results reveal that the LAM process efficiently reduces the cutting force by 22% (feed force) and 20% (thrust force) and produces better workpiece surface quality than conventional planing. 相似文献