检索结果-南通市图书馆

Calculation method of ship collision force on bridge using artificial neural network

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 614-623页

作者： Wei FAN wan-cheng yuan Qi-wu FAN State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Shanghai 200092 China Department of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

Ship collision on bridge is a dynamic process featured by high nonlinearity and instantaneity. Calculating ship-bridge collision force typically involves either the use of design-specification-stipulated equivalent static load, or the use of finite element method (FEM) which is more time-consuming and requires supercomputing resources. In this paper, we proposed an alternative approach that combines FEM with artificial neural network (ANN). The radial basis function neural network (RBFNN) employed for calculating the impact force in consideration of ship-bridge collision mechanics. With ship velocity and mass as the input vectors and ship collision force as the output vector, the neural networks for different network parameters are trained by the learning samples obtained from finite element simulation results. The error analyses of the learning and testing samples show that the proposed RBFNN is accurate enough to calculate ship-bridge collision force. The input-output relationship obtained by the RBFNN is essentially consistent with the typical empirical formulae. Finally, a special toolbox is developed for calculation efficiency in application using MATLAB software.

关键词： Ship-bridge collision force Finite element method (FEM) Artificial neural network (ANN) Radial basis function neural network (RBFNN)

Natural Variation of Pto and Fen Genes and Marker-Assisted Selection for Resistance to Bacterial Speck in Tomato

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2011年第6期10卷 827-837页

作者： SUN wan-yu ZHAO wan-ying wanG yuan-yuan PEI Cheng-cheng YANG Wen-cai Department of Vegetable Science College of Agronomy and Biotechnology China Agricultural University Beijing 100193 P.R.China

The resistance in tomato plants to bacterial speck caused by Pseudomonas syringae pv. tomato is triggered by the interactions between the plant resistance protein Pto and the pathogen avirulence proteins AvrPto or AvrPtoB. Fen is a gene encoding closely related functional protein kinases as the Pto gene. To investigate the status of resistance to the pathogen and natural variation of Pto and Fen genes in tomato, 67 lines including 29 growing in China were subject to disease resistance evaluation and fenthion-sensitivity test. Alleles of Pto and Fen were amplified from genomic DNA of 25 tomato lines using polymerase chain reaction （PCR） and sequences were determined by sequencing the PCR products. The results indicated that none of the 29 cultivars/hybrids growing in China were resistant to bacterial speck race 0 strain DC3000. Seven of eight tomato lines resistant to DC3000 were also fenthion-sensitive. Analysis of deduced amino acid sequences identified three novel residue substitutions between Pto and pto, and one new substitution identified between Fen and fen. A PCR-based marker was developed and successfully used to select plants with resistance to DC3000.

关键词： tomato bacterial speck Pto Fen natural variation marker-assisted selection

Semi-supervised Software Defect Prediction Using Task-Driven Dictionary Learning

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2016年第6期25卷 1089-1096页

作者： CHENG Ming WU guoqing yuan Mengting wan Hongyan School of Computer Wuhan University State Key Laboratory of Software Engineering Wuhan University

We present a semi-supervised approach for software defect prediction. The proposed method is designed to address the special problematic characteristics of software defect datasets, namely, lack of labeled samples and class-imbalanced data. To alleviate these problems, the proposed method features the following components. Being a semi-supervised approach, it exploits the wealth of unlabeled samples in software systems by evaluating the confidence probability of the predicted labels, for each unlabeled sample. And we propose to jointly optimize the classifier parameters and the dictionary by a task-driven formulation, to ensure that the learned features(sparse code) are optimal for the trained classifier. Finally, during the dictionary learning process we take the different misclassification costs into consideration to improve the prediction performance. Experimental results demonstrate that our method outperforms several representative stateof-the-art defect prediction methods.

关键词： Software defect prediction Task-driven dictionary learning Cost-sensitive Semi-supervised learning Sparse representation

Triangular domain extension of linear Bernstein-like trigonometric polynomial basis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第5期11卷 356-364页

作者： wan-qiang SHEN guo-zhao wanG Department of Mathematics Zhejiang University Hangzhou 310027 China

In computer aided geometric design(CAGD),the Bernstein-Bézier system for polynomial space including the triangular domain is an important tool for modeling free form *** Bernstein-like bases for other spaces(trigonometric polynomial,hyperbolic polynomial,or blended space) has also been ***,none of them was extended to the triangular *** this paper,we extend the linear trigonometric polynomial basis to the triangular domain and obtain a new Bernstein-like basis,which is linearly independent and satisfies positivity,partition of unity,symmetry,and boundary *** prove some properties of the corresponding surfaces,including differentiation,subdivision,convex hull,and so *** applications are shown.

关键词： Computer aided geometric design(CAGD) Free form modeling Trigonometric polynomial Basis function Bernstein basis Triangular domain

Sobolev type embedding and weak solutions with a prescribed singular set

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2016年第10期59卷 1975-1994页

作者： guo ZongMing GUAN XiaoHong wan FangShu Department of Mathematics Henan Normal University

New Sobolev type embeddings for some weighted Banach spaces are established. Using such embeddings and the singular positive radial entire solutions, we construct singular positive weak solutions with a prescribed singular set for a weighted elliptic equation. Our main results in this paper also provide positive weak solutions with a prescribed singular set to an equation with Hardy potential.

关键词： positive weak solutions Sobolev type embeddings weighted elliptic equations prescribed singular sets

Generalized Jacobi-Gauss-Lobatto interpolation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2013年第4期8卷 933-960页

作者： Zhengsu wan Benyu guo Chengjian ZHANG School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074 China Department of Mathematics Hunan Institute of Science and Technology Yueyang 414006China Department of Mathematics Shanghai Normal University Shanghai 200234 China

We introduce the generalized Jacobi-Gauss-Lobatto interpolation involving the values of functions and their derivatives at the endpoints, which play important roles in the Jacobi pseudospectral methods for high order problems. We establish some results on these interpolations in non-uniformly weighted Sobolev spaces, which serve as the basic tools in analysis of numerical quadratures and various numerical methods of differential and integral equations.

关键词： Generalized Jacobi-Gauss-Lobatto interpolation pseudospectral method non-uniformly weighted Sobolev space

Degree elevation from Bzier curve to C-Bzier curve with corner cutting form

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2016年第2期31卷 165-176页

作者： SHEN wan-qiang wanG guo-zhao School of Science Jiangnan University Wuxi 214122 China Department of Mathematics Zhejiang University Hangzhou 310027 China State Key Lab of CAD & CG Zhejiang University Hangzhou 310027 China.

The existing results of curve degree elevation mainly focus on the degree of algebraic polynomials. The paper considers the elevation of degree of the trigonometric polynomial, from a Bezier curve on the algebraic polynomial space, to a C-Bezier curve on the algebraic and trigonometric polynomial space. The matrix of degree elevation is obtained by an operator presentation and a derivation pyramid. It possesses not a recursive presentation but a direct expression. The degree elevation process can also be represented as a corner cutting form.

关键词： Curve modeling Bezier curve C-Bezier curve Degree elevation Corner cutting.

Simultaneous Approximation Ratios for Parallel Machine Scheduling Problems

在线全文

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2019年第3期7卷 485-500页

作者： Long wan Jin-Jiang yuan School of Information Technology Jiangxi University of Financeand EconomicsNanchang 310013China School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China

Motivated by the problem to approximate all feasible schedules by one schedule in a given scheduling environment,we introduce in this paper the concepts of strong simultaneous approximation ratio and weak simultaneous approximation *** we study the two variants under various scheduling environments,such as non-preemptive,preemptive or fractional scheduling on identical,related or unrelated machines.

关键词： Scheduling Simultaneous approximation ratio Global fairness

Electromigration in eutectic SnAg solder reaction couples with various ambient temperatures and current densities

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2009年第6期16卷 685-690页

作者： Guang-chen Xu Fu guo wan-rong Zhu College of Materials Science and Engineering Beijing University of Technology Beijing 100124 China

The electromigration behavior of eutectic SnAg solder reaction couples was studied at various temperature （25 and 120℃ when the current density was held constant at 104 A/cm^2 or 5×10^3 A/cm^2. Under the current density of 104 A/cm^2, scallop type Cu6Sn5 spalls and migrates towards the direction of electron flow at room ambient temperature （25℃）, but transforms to layer type Cu3Sn and leaves Kirkendall voids in it at high ambient temperature （120℃）. Under the current density of 5×10^3 A/cm^2 plus room ambient temperature, no obvious directional migration of metal atoms/ions is found. Instead, the thermal stress induced by mismatch of dissimilar materials causes the formation of superficial valley at both interfaces. However, when the ambient temperature increases to 120℃, the mobility of metal atoms/ions is enhanced, and then the grains rotate due to the anisotropic property of β-Sn.

关键词： electromigration eutectic solder Joule heating intermetallic compound