We present a general framework for a higher-order spline level-set (HLS) method and apply this to smooth surface constructions. Starting from a first order energy functional, we obtain a general ...level set formulation of geometric partial differential equation, and provide an efficient approach to solve this partial differential equation using a C 2 spline basis. We also present a fast cubic spline interpolation algorithm based on convolution and the Z-transform, which exploits the local relationship of interpolatory cubic spline coefficients with respect to given function data values. We provide two demonstrative smooth surface construction examples of our HLS method. The first is the construction of a smooth surface model (an implicit solvation interface) of bio-molecules in solvent, given their individual atomic coordinates and solvated radii. The second is the smooth surface reconstruction from a cloud of points generated from a 3D surface scanner.
Quality multi-domain meshing for volumetric data Qin Zhang; Subramanian, B; Guoliang Xu ...
2010 3rd International Conference on Biomedical Engineering and Informatics,
10/2010, Volume:
2
Conference Proceeding, Journal Article
Open access
Multi-domain meshing from volumetric data is of great importance in many fields like medicine, biology and geology. This paper proposes a new approach to produce a high quality mesh with separated ...multiple domains. A point cloud is generated from a preliminary mesh representing the boundary between different domains from the discrete volumetric representation used as input. A higher-order level-set method is employed to produce a quality sub-mesh from this point cloud and geometric flow is used as smoothing mechanism. A new approach to detect and curate intersections within an assembly of these 2-manifold sub-meshes by utilizing the intermediate volumetric representation is developed. The separation between sub-meshes can be controlled by the user using a gap threshold parameter. The resulting high quality multi-domain mesh is free from self- and inter-domain intersections and can be further utilized in finite element and boundary element computations. The proposed pipeline has been efficiently implemented and sample meshes have been provided for visualization.
The characteristics of membrane fouling control in membrane bioreactors (MBR) were studied with the addition of coagulants Al sub(2)(SO sub(4)) sub(3), FeCl sub(3), polymeric ferric sulfate (PFS), ...polymeric aluminum chloride (PAC), and cationic polyacrylamide (PAM) directly into activated sludge. In the batch experiments, the colloids from 0.2 mu m to 1.5 mu m were identified as the most important foulants for the microfiltration membrane with a pore size of 0.2 mu m in submerged MBR. Considering specific filtration resistance, colloidal TOC, pH and particle size distributions, the effect of each coagulant was in the order of: PAC>PFS> FeCl sub(3)>Al sub(2)(SO sub(4)) sub(3)>PAM. In the long-term tests, PAC and PFS were added in two submerged MBRs and their effects on membrane fouling control were confirmed. Among the selected coagulants, PAC was found to be the most effective on membrane fouling control at the optimal dosage about 1.0 mM Al. At this dose, the biological activity of activated sludge and the removals of COD, BOD sub(5), and NH super(+) sub(4)-N were not affected obviously by coagulation in the long-term operation. The removals of COD, BOD sub(5) and NH super(+) sub(4)-N exceeded 80%, 95% and 90%, respectively. Coagulants alleviated colloidal TOC and thus protected the membrane from fouling. Moreover, particles smaller than 2.512 mu m could not be measured by the instrument, and the particle size distributions were not responsible for membrane fouling control.
Poly(D,L-lactic acid)-co-poly(ethylene glycol) copolymer (D,L-PLEG) synthesized by melt polycondensation was irradiated using low energy electron beam (EB) in the presence of triallyl cyanurate (TAC) ...and tetraallyl pentaerythritol (TAPE) as crosslinking agents. The tensile strength of D,L-PLEG/TAC and D,L-PLEG/TAPE samples increases up to 48 MPa and 28 MPa at dose of 80 kGy and 60 kGy, respectively, and decreases with further increase of dose, whereas the elongation at break decreases continuously with increasing dose. The glass transition temperature (
) is improved to some extent due to the formation of molecular chain network. Degradation of D,L-PLEG is retarded with introduction of cross-linked network. The results suggest that the physical properties of crosslinked D,L-PLEG can be adjusted easily by varying irradiation dose.
A general formulation based on the variation of digitized energy to denoise image is proposed in this paper. This method is different from classical variational method employed in image processing. ...For a digitized energy functional, we first compute the variation, then design algorithms leading to digital filters. Numerical experiments and comparative examples are thus carried out to verify the effectiveness of the proposed method, which is efficient, adaptive and easily implemented. Higher quality images can be obtained with characteristic singular features preserved. The method can be easily expanded to multichannel image denoising.
In electronics, silicon-based metal thin films are a sort of common material structure. In practical applications, electronic packaging materials should show stable mechanical properties under ...temperature changes, as well as predicted and preventing the fatigue failure. In this paper, Digital Image Correlation method was employed to measure the thermal strain and thermal stress of silicon-based metal thin film. It has been investigated that the feasibility of DIC Method to determine the thermal stress of thin film and the impact of the temperature range on measurement. The heating process of thin film was simulated by a quarter thin film model. The results shows that the DIC method was well suitable to determine the thermal stress of thin film with low error. Besides, the longer the temperature range is, the more accurate the measuring is. This provides a method of undamaged test on the thermal stress of thin film.
介绍了玉米单倍体的发展历程、玉米单倍体诱导和加倍方法的研究进展，对单倍体育种应用价值和前景进行了评述。著者文摘
The advances in haploid hisrory, haploid induction and doubling methods in maize were reviewed in the paper. The advantages and perspective of ...haploid application were summarized as well.
Automatic reconstruction of surfaces and scalar fields from 3D scans Bajaj, Chandrajit L.; Bernardini, Fausto; Xu, Guoliang
International Conference on Computer Graphics and Interactive Techniques: Proceedings of the 22nd annual conference on Computer graphics and interactive techniques,
1995
Conference Proceeding
In this paper, we present a stable, reliable and robust method for reconstructing a three dimensional density function from a set of two dimensional electron microscopy images. By minimizing an ...energy functional consisting of a fidelity term and a regularization term, a L 2 -gradient flow is derived. The flow is integrated by a finite element method in the spatial direction and an explicit Euler scheme in temporal direction. The experimental results show that the proposed method is efficient and effective.
Generating diagnosis rules based on a new rough distance Bin Nie; Jianqiang Du; Riyue Yu ...
2010 International Conference on Computer Application and System Modeling (ICCASM 2010),
2010-Oct., Volume:
7
Conference Proceeding
The paper put forward a new rough distance for generating diagnosis rules, it was proved to be feasible and effective after tested with diabetes and its complications sub-database.
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