80 research outputs found
Improved Kansa RBF Method for the Solution of Nonlinear Boundary Value Problems
We apply the Kansa–radial basis function (RBF) collocation method to two-dimensional nonlinear boundary value problems. In it, the solution is approximated by a linear combination of RBFs and the governing equation and boundary conditions are satisfied in a collocation sense at interior and boundary points, respectively. The nonlinear system of equations resulting from the Kansa–RBF discretization for the unknown coefficients in the RBF approximation is solved by directly applying a standard nonlinear solver. In a natural way, the value of the shape parameter in the RBFs employed in the approximation may be included in the unknowns to be determined. The numerical results of several examples are presented and analyzed
Polynomial Particular Solutions for Solving Elliptic Partial Differential Equations
In the past, polynomial particular solutions have been obtained for certain types of partial differential operators without convection terms. In this paper, a closed-form particular solution for more general partial differential operators with constant coefficients has been derived for polynomial basis functions. The newly derived particular solution is further coupled with the method of particular solutions (MPS) for numerically solving a large class of elliptic partial differential equations. In contrast to the use of Chebyshev polynomial basis functions, the proposed approach is more flexible in selecting the collocation points inside the domain. The polynomial basis functions are well-known for yielding ill-conditioned systems when their order becomes large. The multiple scale technique is applied to circumvent the difficulty of ill-conditioning problem. Five numerical examples are presented to demonstrate the effectiveness of the proposed algorithm
The Method of Particular Solutions Using Trigonometric Basis Functions
In this paper, the method of particular solutions (MPS) using trigonometric functions as the basis functions is proposed to solve two-dimensional elliptic partial differential equations. The inhomogeneous term of the governing equation is approximated by Fourier series and the closed-form particular solutions of trigonometric functions are derived using the method of undetermined coefficients. Once the particular solutions for the trigonometric basis functions are derived, the standard MPS can be applied for solving partial differential equations. In comparing with the use of radial basis functions and polynomials in the MPS, our proposed approach provides another simple approach to effectively solving two-dimensional elliptic partial differential equations. Five numerical examples are provided in this paper to validate the merits of the proposed meshless method
A SCADA System for Mobile Industry
Taiwanese mobile telecom industry encounters the difficult of operation and management due to the dispersing of mobile stations and telecom system in different areas. Therefore it is the important policy for mobile industry that how to draft an effective operation method and to drop the cost of management and human resource. The aim of this research is to study the operation and management cost reduction of the mobile industry through the supervisor control and data acquisition (SCADA) system application during globalization, privatization and liberalization competition. Results indicated that the SCADA system has been highly willing to mobile industry in the development of power supply quality and to drop the operation and management cost. Also this research aims at measuring the benefit on SCADA system and to provide decision-makers with useful operation and management strategies as reference
Particular Solutions of Products of Helmholtz-Type Equations Using the Matern Function
We derive closed-form particular solutions for Helmholtz-type partial differential equations. These are derived explicitly using the Matern basis functions. The derivation of such particular solutions is further extended to the cases of products of Helmholtz-type operators in two and three dimensions. The main idea of the paper is to link the derivation of the particular solutions to the known fundamental solutions of certain differential operators. The newly derived particular solutions are used, in the context of the method of particular solutions, to solve boundary value problems governed by a certain class of products of Helmholtz-type equations. The leave-one-out cross validation (LOOCV) algorithm is employed to select an appropriate shape parameter for the Matern basis functions. Three numerical examples are given to demonstrate the effectiveness of the proposed method
Detection of EBV Infection and Gene Expression in Oral Cancer from Patients in Taiwan by Microarray Analysis
Epstein-Barr virus is known to cause nasopharyngeal carcinoma. Although oral cavity is located close to the nasal pharynx, the pathogenetic role of Epstein-Barr virus (EBV) in oral cancers is unclear. This molecular epidemiology study uses EBV genomic microarray (EBV-chip) to simultaneously detect the prevalent rate and viral gene expression patterns in 57 oral squamous cell carcinoma biopsies (OSCC) collected from patients in Taiwan. The majority of the specimens (82.5%) were EBV-positive that probably expressed coincidently the genes for EBNAs, LMP2A and 2B, and certain structural proteins. Importantly, the genes fabricated at the spots 61 (BBRF1, BBRF2, and BBRF3) and 68 (BDLF4 and BDRF1) on EBV-chip were actively expressed in a significantly greater number of OSCC exhibiting exophytic morphology or ulceration than those tissues with deep invasive lesions (P = .0265 and .0141, resp.). The results may thus provide the lead information for understanding the role of EBV in oral cancer pathogenesis
Effects of manual lymphatic drainage on breast cancer-related lymphedema: a systematic review and meta-analysis of randomized controlled trials
BACKGROUND: Lymphedema is a common complication of axillary dissection for breast cancer. We investigated whether manual lymphatic drainage (MLD) could prevent or manage limb edema in women after breast-cancer surgery. METHODS: We performed a systematic review and meta-analysis of published randomized controlled trials (RCTs) to evaluate the effectiveness of MLD in the prevention and treatment of breast-cancer-related lymphedema. The PubMed, EMBASE, CINAHL, Physiotherapy Evidence Database (PEDro), SCOPUS, and Cochrane Central Register of Controlled Trials electronic databases were searched for articles on MLD published before December 2012, with no language restrictions. The primary outcome for prevention was the incidence of postoperative lymphedema. The outcome for management of lymphedema was a reduction in edema volume. RESULTS: In total, 10 RCTs with 566 patients were identified. Two studies evaluating the preventive outcome of MLD found no significant difference in the incidence of lymphedema between the MLD and standard treatment groups, with a risk ratio of 0.63 and a 95% confidence interval (CI) of 0.14 to 2.82. Seven studies assessed the reduction in arm volume, and found no significant difference between the MLD and standard treatment groups, with a weighted mean difference of 75.12 (95% CI, −9.34 to 159.58). CONCLUSIONS: The current evidence from RCTs does not support the use of MLD in preventing or treating lymphedema. However, clinical and statistical inconsistencies between the various studies confounded our evaluation of the effect of MLD on breast-cancer-related lymphedema
Pin1 positively affects tumorigenesis of esophageal squamous cell carcinoma and correlates with poor survival of patients
Induction of cyclooxygenase-2 overexpression in human gastric epithelial cells by Helicobacter pylori involves TLR2/TLR9 and c-Srcdependent nuclear factor-
ABSTRACT Gastric epithelial cells were incubated with a panel of clinical isolates of Helicobacter pylori, including nonulcer dyspepsia with gastritis (HS, n ϭ 20), gastric ulcer (HU, n ϭ 20), duodenal ulcer (HD, n ϭ 21), and gastric cancer (HC, n ϭ 20). HC strains induced a higher cyclooxygenase-2 (COX-2) expression than those from HS, HD, and HU. The bacterial virulence factors and the host cellular pathways were investigated. Virulence genes of iceA, vacA, babA2, cagA 3Ј repeat region, and hrgA failed to show any association with the disease status and COX-2 expression. Methylation-specific polymerase chain reaction revealed HC strains not affecting the methylation status of COX-2 promoter. Nuclear factor (NF)-B, NF-interleukin 6, and cAMP response element were found to be involved in COX-2 induction. We explored a novel NF-B activation pathway. The mutants of TLR2 and TLR9, but not TLR4, inhibited H. pyloriinduced COX-2 promoter activity, and neutralizing antibodies for TLR2 and TLR9 abolished H. pylori-induced COX-2 expression
- …