Optimal Viewpoint Extraction of 3D Model Based on AdaBoost Iterative Algorithm

Dong Tao 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.1

According to the limitations of a single measurement algorithm in the current 3D models’ viewpoint extraction, this essay puts forward a viewpoint extraction algorithm based on AdaBoost iterative algorithm, which can make the features adaptive automatically. It, firstly, extracts 3D models’ feature descriptor and feature vector in the model library and adopts AdaBoost iterative algorithm to establish rules about classification and matching from geometric features and various viewpoint extraction algorithm; then, it constructs decision classifier in order to extract optimal viewpoint. In query process, the model obtains viewpoint extraction algorithm which can suit its geometric feature through decision classifier and then gets its best view by calculation. The experimental result shows this algorithm extraction effect is superior to the one by a single measurement algorithm.

Application of Improved SVM Algorithm in Color Image De-Noising

Dong Tao 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8

It cannot avoid the noise interference in image processing, whether it is image generation, or image transmission, among them, the most typical noise is salt and pepper noise and Gaussian noise. The salt and pepper noise will cause the image showing the random distribution of noise points, thus greatly reduce the image quality. The Gaussian noise affects the input, collection and output of the image processing. Gaussian noise will make the image blurred. Therefore, the image de-noising plays a very important role in image processing. It has direct influence on image segmentation, feature extraction and image recognition. As is known to all, the support vector machine has the advantages of solving the problem of nonlinear, high dimension and local minimum points. In this article, we use this advantage to propose an image de-noising method which is based on it. The method uses support vector regression to construct the filter for image de-noising. The feature extraction and training samples are designed to suppress different types of noise. Firstly, we use the noise pixel as the center of the 5*5 window, and generate the input vector of SVM from row to column. Secondly, we set the output of the support vector filter as an image that is not contaminated by noise. At this point, we get the training samples of SVM filter. In addition, the parameter selection of support vector machine has a great influence on the result of image de-noising. Therefore, the particle swarm optimization algorithm is proposed in this article to optimize the parameters of SVM. Finally, we adding the simulated salt and pepper noise and Gaussian noise in the original Lena image, and using several methods to carry out the de-noising experiment. From the experimental results we can see that the de-noising effect of filtering algorithm of this paper is very good for the two kinds of noise. It can effectively remove the noise, and better maintain the details and the color of the image.

Bulk Nanocrystalline SmCo₅ Permanent Magnet Prepared by Spark Plasma Sintering

Zhang Dongtao,Yue Ming,Zhang Jiuxing,Pan Lijun 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Failure Analysis on Pressure Leakage of FRP

Guoquan Qi,Dongtao Qi,Qiang Bai,Houbu Li,Bin Wei,Nan Ding,Dongna Zhang,Xiaodong Shao 한국섬유공학회 2019 Fibers and polymers Vol.20 No.3

The fiberglass reinforced plastic (FRP) pipe used in the ground gathering system of an oil field occurred leakagefailure during the pressure test on site after installation. Investigations were performed to identify the most probable causes of the pipe failures. Take three types of specimens for the study, which is the leak position of failure line; the non-leaked position of failure line and the standby pipeline after insulation. The study was conducted by reviewing the background of the incident, visual physical inspection, mechanical property test and finite element analysis. The reason for the failure of this batch pipe is that, a large number of circumferential cracks appear on the outer wall of the pipe under the external force dominated by the bending stress, which reduced the overall internal pressure performance and caused the leakage failure of the pipe line. The leakage failure during the pressure test on site is mostly located in the transition zone of the pipe body to joint, which is due to the discontinuity of wall thickness and uneven material.

Molecular Cloning and Expression of a Cu/Zn-Containing Superoxide Dismutase from Thellungiella halophila

Xu Xiaojing,Zhou Yijun,Wei Shanjun,Ren Dongtao,Yang Min,Bu Huahu,Kang Mingming,Wang Junli,Feng Jinchao 한국분자세포생물학회 2009 Molecules and cells Vol.27 No.4

Superoxide dismutases (SODs) constitute the first line of cellular defense against oxidative stress in plants. SODs generally occur in three different forms with Cu/Zn, Fe, or Mn as prosthetic metals. We cloned the full-length cDNA of the Thellungiella halophila Cu/Zn-SOD gene ThCSD using degenerate RT-PCR and rapid amplification of cDNA ends (RACE). Sequence analysis indicated that the ThCSD gene (GenBank accession number EF405867) had an open reading frame of 456 bp. The deduced 152-amino acid polypeptide had a predicted molecular weight of 15.1 kDa, an estimated pI of 5.4, and a putative Cu/Zn-binding site. Recombinant ThCSD protein was expressed in Escherichia coli and assayed for SOD enzymatic activity in a native polyacrylamide gel. The SOD activity of ThCSD was inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide, confirming that ThCSD is a Cu/Zn-SOD. Northern blotting demonstrated that ThCSD is expressed in roots, stems, and leaves. ThCSD mRNA levels increased by about 30-fold when plants were treated with sodium chloride (NaCl), abscisic acid (ABA), and indole-acetic acid (IAA) and by about 50-fold when treated with UVB light. These results indicate that ThCSD is involved in physiological pathways activated by a variety of environmental conditions.

Cotton GhKCH2, a Plant-specific Kinesin, is Low-affinitive and Nucleotide-independent as Binding to Microtubule

Xu, Tao,Sun, Xuewei,Jiang, Shiling,Ren, Dongtao,Liu, Guoqin Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.5

Kinesin is an ATP-driven microtubule motor protein that plays important roles in control of microtubule dynamics, intracellular transport, cell division and signal transduction. The kinesin superfamily is composed of numerous members that are classified into 14 subfamilies. Animal kinesins have been well characterized. In contrast, plant kinesins have not yet to be characterized adequately. Here, a novel plant-specific kinesin gene, GhKCH2, has been cloned from cotton (Gossypium hirsutum) fibers and biochemically identified by prokaryotic expression, affinity purification, ATPase activity assay and microtubule-binding analysis. The putative motor domain of GhKCH2, $M_{396-734}$ corresponding to amino acids Q396-N734 was fused with 6$\times$His-tag, soluble-expressed in E. coli and affinity-purified in a large amount. The biochemical analysis demonstrated that the basal ATPase activity of $M_{396-734}$ is not activated by $Ca^{2+}$, but stimulated 30-fold max by microtubules. The enzymatic activation is microtubule-concentration-dependent, and the concentration of microtubules that corresponds to half-maximum activation was about 11 ${\mu}M$, much higher than that of other kinesins reported. The cosedimentation assay indicated that $M_{396-734}$ could bind to microtubules in vitro whenever the nucleotide AMP-PNP is present or absent. As a plant-specific microtubule-dependent kinesin with a lower microtubule-affinity and a nucleotide-independent microtubule-binding ability, cotton GhKCH2 might be involved in the function of microtubules during the deposition of cellulose microfibrils in fibers or the formation of cell wall.

Two Kinesins from Arabidopsis, KatB and KatC, Have a Second Microtubule-binding Site in the Tail Domain

Jiang, Shiling,Li, Ming,Xu, Tao,Ren, Dongtao,Liu, Guoqin Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.1

Kinesins, as a kind of microtubule-based motor proteins, have a conserved microtubule-binding site in their motor domain. Here we report that two homologous kinesins in Arabidopsis thaliana, KatB and KatC, contain a second microtubule-binding site in their tail domains. The prokaryotic-expressed N-terminal tail domain of the KatC heavy chain can bind to microtubules in an ATP-insensitive manner. To identify the precise region responsible for the binding, a serious of truncated KatC cDNAs encoding KatC N-terminal regions in different lengths, KatC1-128, KatC1-86, KatC1-73 and KatC1-63, fused to Histidine-tags, were expressed in E. coli and affinity-purified. Microtubule cosedimentation assays show that the site at amino acid residues 74-86 in KatC is important for microtubule-binding. By similarity, we obtained three different lengths of KatB N-terminal regions, KatB1-384, KatB1-77, and KatB1-63, and analyzed their microtubule-binding ability. Cosedimentation assays indicate that the KatB tail domain can also bind to microtubules at the same site as and in a similar manner to KatC. Fluorescence microscopic observations show that the microtubule-binding site at the tail domain of KatB or KatC can induce microtubules bundling only when the stalk domain is present. Through pull-down assays, we show that KatB1-385 and KatC1-394 are able to interact specifically with themselves and with each other in vitro. These findings are significant for identifying a previously uncharacterized microtubule-binding site in the two kinesin proteins, KatB and KatC, and the functional relations between them.

Influence of Laser Power on Grain Size and Tensile Strength of 5A90 Al–Li Alloy T-joint Fabricated by Dual Laser-Beam Bilateral Synchronous Welding

Shuai Chen,Xiaohong Zhan,Yanqiu Zhao,Youfa Wu,Dongtao Liu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Dual laser-beam bilateral synchronous welding is introduced to produce the 2.5 mm thick 5A90 Al–Li alloy T-joint. Thegrain morphology and grain size of weld metal (WM) in the T-joint are analyzed and calculated. The tensile experiment,scanning electron microscopy and energy disperse spectroscopy are respectively employed to study the tensile strength,fracture morphology and chemical composition of the T-joint. The results reveal that when the laser power is increased from2500 to 3000 W, the grain sizes of fine-grained layers and columnar dendrites near the fusion line are significantly reduced. Conversely, that of equiaxed dendrites at the WM center is not sensitive to the variety of laser power. Moreover, the degreeof elemental segregation in WM near the fusion line is also aggravated with the increasing of the laser power. The tensilestrength of the T-joint with the laser power of 2500 W is significantly higher than that with the laser power of 3000 W. Thetensile fracture locations are occurred in the weld toe with obvious pores, shear dimples and tear ridges, which are the typicalcharacteristics of ductile fracture. Besides, the chemical compositions of the second phase particles in the WM are moresensitive to than the variation of laser power compared with that of the matrix.