The two dimensional problem of simply supported laminated isotropic strips with viscoelastic interfaces and under static loading was studied. Exact solution was derived based on the exact elasticity equation and the K...The two dimensional problem of simply supported laminated isotropic strips with viscoelastic interfaces and under static loading was studied. Exact solution was derived based on the exact elasticity equation and the Kelvin-Voigt viscoelastic interfacial model. Numerical computations were performed for a strip consisting of three layers of equal thickness. Results indicated that the response of the laminate was very sensitive to the presence of viscoelastic interfaces.展开更多
A direct texture synthesis method on arbitrary surfaces is proposed in thispaper. The idea is to recursively map triangles on surface to texture space until the surface iscompletely mapped. First, the surface is simpl...A direct texture synthesis method on arbitrary surfaces is proposed in thispaper. The idea is to recursively map triangles on surface to texture space until the surface iscompletely mapped. First, the surface is simplified and a tangential vector field is created overthe simplified mesh. Then, mapping process searches for the most optimal texture coordinates intexture sample for each triangle, and the textures of neighboring triangles are blended on the mesh.All synthesized texture triangles are compressed to an atlas. Finally, the simplified mesh issubdivided to approach the initial surface. The algorithm has several advantages over formermethods: it synthesizes texture on surface without local parameterization; it does not needpartitioning surface to patches; and it does not need a particular texture sample. The resultsdemonstrate that the new algorithm is applicable to a wide variety of texture samples and anytriangulated surfaces.展开更多
This paper investigates a preemptive semi-online scheduling problem onm identical parallel machines wherem=2,3. It is assumed that all jobs have their processing times in betweenp andrp (p > 0,r ≥1). The goal is t...This paper investigates a preemptive semi-online scheduling problem onm identical parallel machines wherem=2,3. It is assumed that all jobs have their processing times in betweenp andrp (p > 0,r ≥1). The goal is to minimize the makespan. Best possible algorithms are designed for anyr≥1 whenm=2,3. Keywords semi-online - scheduling - preemption - competitive ratio Regular PaperThis research is supported by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE. China, and the National Natural Science Foundation of China (Grant Nos. 10271110 and 60021201).Yong He received his B.S., M.S., and Ph.D. degrees all from Zhejiang University in 1989, 1992, 1996, respectively. He is currently a professor and Ph.D. supervisor at Department of Mathematics, Zhejiang University. His current research interests include combinatorial and network optimization, scheduling theory, computational biology, mathematical modeling, etc.Yi-Wei Jiang received his B.S. degree from Zhejiang University in 2002. He is currently a Ph.D. candidate of Zhejiang University. His current interests include scheduling theory and online algorithms.展开更多
Based on the equation of transfer in transport theory of optical physics,a new volume rendering model, called composed scattering model (CSM), is presented. In calculating the scattering term of the equation, it is de...Based on the equation of transfer in transport theory of optical physics,a new volume rendering model, called composed scattering model (CSM), is presented. In calculating the scattering term of the equation, it is decomposed into volume scattering intensity and surface scattering intensity, and they are composed with the boundary detection operator as the weight function. This proposed model differs from the most current volume rendering models in the aspect that in CSM segmentation and illumination intensity calculation are taken as two coherent parts while in ekisting models they are regarded as two separate ones. This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI. The resultant images show not only rich details but also clear boundary surfaces. CSM is demonstrated to be an accurate volume rendering model suitable for CT and MRI data sets.展开更多
Under the volume segmentation in voxel space, a lot of details, some fine and thin objects, are ignored. In order to accurately display these details, this paper has developed a methodology for volume segmentation in...Under the volume segmentation in voxel space, a lot of details, some fine and thin objects, are ignored. In order to accurately display these details, this paper has developed a methodology for volume segmentation in subvoxel space. In the subvoxel space, most of the 'bridges' between adjacent layers are broken down.Based on the subvoxel space, an automatic segmentation algorithm reserving details is discussed. After segmentation, volume data in subvoxel space are reduced to original voxel space. Thus, the details with width of only one or several voxels are extracted and displayed.展开更多
文摘The two dimensional problem of simply supported laminated isotropic strips with viscoelastic interfaces and under static loading was studied. Exact solution was derived based on the exact elasticity equation and the Kelvin-Voigt viscoelastic interfacial model. Numerical computations were performed for a strip consisting of three layers of equal thickness. Results indicated that the response of the laminate was very sensitive to the presence of viscoelastic interfaces.
文摘A direct texture synthesis method on arbitrary surfaces is proposed in thispaper. The idea is to recursively map triangles on surface to texture space until the surface iscompletely mapped. First, the surface is simplified and a tangential vector field is created overthe simplified mesh. Then, mapping process searches for the most optimal texture coordinates intexture sample for each triangle, and the textures of neighboring triangles are blended on the mesh.All synthesized texture triangles are compressed to an atlas. Finally, the simplified mesh issubdivided to approach the initial surface. The algorithm has several advantages over formermethods: it synthesizes texture on surface without local parameterization; it does not needpartitioning surface to patches; and it does not need a particular texture sample. The resultsdemonstrate that the new algorithm is applicable to a wide variety of texture samples and anytriangulated surfaces.
文摘This paper investigates a preemptive semi-online scheduling problem onm identical parallel machines wherem=2,3. It is assumed that all jobs have their processing times in betweenp andrp (p > 0,r ≥1). The goal is to minimize the makespan. Best possible algorithms are designed for anyr≥1 whenm=2,3. Keywords semi-online - scheduling - preemption - competitive ratio Regular PaperThis research is supported by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE. China, and the National Natural Science Foundation of China (Grant Nos. 10271110 and 60021201).Yong He received his B.S., M.S., and Ph.D. degrees all from Zhejiang University in 1989, 1992, 1996, respectively. He is currently a professor and Ph.D. supervisor at Department of Mathematics, Zhejiang University. His current research interests include combinatorial and network optimization, scheduling theory, computational biology, mathematical modeling, etc.Yi-Wei Jiang received his B.S. degree from Zhejiang University in 2002. He is currently a Ph.D. candidate of Zhejiang University. His current interests include scheduling theory and online algorithms.
文摘Based on the equation of transfer in transport theory of optical physics,a new volume rendering model, called composed scattering model (CSM), is presented. In calculating the scattering term of the equation, it is decomposed into volume scattering intensity and surface scattering intensity, and they are composed with the boundary detection operator as the weight function. This proposed model differs from the most current volume rendering models in the aspect that in CSM segmentation and illumination intensity calculation are taken as two coherent parts while in ekisting models they are regarded as two separate ones. This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI. The resultant images show not only rich details but also clear boundary surfaces. CSM is demonstrated to be an accurate volume rendering model suitable for CT and MRI data sets.
文摘Under the volume segmentation in voxel space, a lot of details, some fine and thin objects, are ignored. In order to accurately display these details, this paper has developed a methodology for volume segmentation in subvoxel space. In the subvoxel space, most of the 'bridges' between adjacent layers are broken down.Based on the subvoxel space, an automatic segmentation algorithm reserving details is discussed. After segmentation, volume data in subvoxel space are reduced to original voxel space. Thus, the details with width of only one or several voxels are extracted and displayed.
