Results 71 to 80 of about 6,728 (222)
Energy Science &Engineering, EarlyView.On the basis of core and log data, a Bayesian‐Optimized Random Forest model achieved 92.76% accuracy in classifying tight sandstone reservoirs. A gray relational analysis‐derived evaluation index shows > 80% consistency with actual gas zones. ABSTRACT Tight sandstone gas (TSG), an unconventional oil–gas resource, has heterogeneous reservoirs ...
Yin Yuan +8 more
wiley +1 more source
Two adaptive rejection sampling schemes for probability density functions log-convex tails [PDF]
, 2011 Monte Carlo methods are often necessary for the implementation of optimal Bayesian estimators. A fundamental technique that can be used to generate samples from virtually any target probability distribution is the so-called rejection sampling method ...
Martino, Luca, Míguez, Joaquín
core +2 more sources
Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver
International Journal for Numerical Methods in Fluids, EarlyView.A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
wiley +1 more source
Multiplicity of Solutions to a Potential Operator Equation and Its Applications
Abstract and Applied Analysis, 2014 We consider the multiplicity of solutions for operator equation involving homogeneous potential operators. With the help of Nehari manifold and fibering maps, we prove that such equation has at least two nontrivial solutions.
Jincheng Huang
doaj +1 more source
Three nontrivial solutions for the p-Laplacian Neumann problems with a concave nonlinearity near the origin [PDF]
, 2010 We consider a nonlinear Neumann problem driven by the p- Laplacian, with a right-hand side nonlinearity which is concave near the origin. Using variational techniques, combined with the method of upper-lower solutions and with Morse theory, we show ...
Aizicovici, Sergiu +2 more
core +1 more source
Bifurcation near infinity for the Neumann problem with concave–convex nonlinearities
Comptes Rendus. Mathématique, 2014 In this Note, we study a class of Neumann parametric elliptic equations driven by a nonhomogeneous differential operator and with a reaction that exhibits competing terms (concave–convex nonlinearities). Using the Ambrosetti–Rabinowitz condition and related topological and variational arguments, we prove a bifurcation result for large values of the ...
Papageorgiou, Nikolaos S. +1 more
openaire +2 more sources
Point and Risk estImation Using an enSemble of Models for Nowcasting: PRISM‐Now
Journal of Forecasting, EarlyView.ABSTRACT We propose PRISM‐Now, a novel ensemble forecasting system for near‐term GDP projection. Recognizing that relevant economic information evolves over time, we treat forecasts from multiple base models as draws from a mixture distribution of “good” and “bad” estimates, whose composition changes continuously and cannot be identified ex ante.
Beomseok Seo, Hyungbae Cho, Dongjae Lee
wiley +1 more source
Weak Solutions for a Class of Nonlocal Singular Problems Over the Nehari Manifold
Mathematical Methods in the Applied Sciences, EarlyView.ABSTRACT In this paper, we consider a nonlocal model of dilatant non‐Newtonian fluid with a Dirichlet boundary condition. By using the Nehari manifold and fibering map methods, we obtain the existence of at least two weak solutions, with sign information.
Zhenfeng Zhang +2 more
wiley +1 more source
Multiple Solutions for Nonlocal Fourth-Order Equation with Concave–Convex Nonlinearities
MathematicsThis paper is devoted to a class of general nonlocal fourth-order elliptic equation with concave–convex nonlinearities. First, using the Z2-mountain pass theorem in critical point theory, we obtain the existence of infinitely many large energy solutions.
Ruiting Jiang, Chengbo Zhai
doaj +1 more source
Experimental investigation of the flow-induced vibration of a curved circular cylinder [PDF]
, 2012 Experiments have been conducted to investigate the vortex-induced vibration (VIV) response of a rigid section of a curved circular cylinder. Two curved configurations, a concave and a convex, were tested regarding the direction of the flow, in addition ...
Assi, Gustavo +3 more
core