Hydrograph recession constants are required in rainfall-runoff models, base flow augmentation studies, geohydrologic investigations and in regional low-flow studies. The recession portion of a streamflow hydrograph is shown to be either an autoregressive process or an integrated moving average process, depending upon the structure of the assumed model errors. Six different estimators of the bas...

Point sets from range scanners are noisy and do not contain additional data such as normals, which makes it difficult to create a mesh for rendering. We use the moving least-squares (MLS) approximation to get normals and differential information, and approximate the surface near each point by an MLS surface. From this we obtain a splat of a new octagonal shape which approximates the local curva...

Free-form deformation (FFD) is widely used in deformable image registration. FFD uses a regular grid of control points to generate image deformation. Accurate optimization of the control-point displacement relies on an appropriate initial-deformation of the regular grid. In this work, a hybrid registration of landmark-based and free-form deformation is proposed and applied to lung CT images. Co...

The method of finite spheres using moving least squares interpolants and point collocation as the weighted residual scheme is applied to the development of a virtual reality based training system for laparoscopic surgical procedures. The localization of approximation and the lack of numerical integration results in very high computational speeds required for real time simulation with graphical ...

Moving-Least Squares (MLS) surfaces are a popular way to define a smooth manifold surface from a set of unorganized points without normals. In this paper we present a formulation of MLS surfaces that sheds light on shortcomings of the original technique proposed by Levin, which is based on a two-step minimization procedure. We show that there are cases intrinsic to the geometry of the underlyin...

This paper considers conservation of momentum and tensile instability in transient dynamic particle methods. Local particle methods are defined as representing a continuous body with particles which discretize the body. The particles carry the field variables and are used for interpolation purposes. They also are discrete chunks of matter which must have mass and volume which in sum represent t...

Approximations of non-smooth multivariate functions return low-order approximations in the vicinities of the singularities. Most prior works solve this problem for univariate functions. In this work we introduce a method for approximating non-smooth multivariate functions of the form f = g + r+ where g, r ∈ C(R) and the function r+ is defined by r+(y) = { r(y), r(y) ≥ 0 0, r(y) < 0 , ∀y ∈ R . G...

This paper is aimed at presenting a partition of unity method for the simulation of three-dimensional dynamic crack propagation. The method is a variation of the partition of unity ®nite element method and hp-cloud method. In the context of crack simulation, this method allows for modeling of arbitrary dynamic crack propagation without any remeshing of the domain. In the proposed method, the ap...

Many models have been developed to forecast wind farm power output. It is generally difficult to determine whether the performance of one model is consistently better than that of another model under all circumstances. Motivated by this finding, we aimed to integrate groups of models into an aggregated model using fuzzy theory to obtain further performance improvements. First, three groups of l...

We present the basic formal and numerical aspects of higher-degree interpolated moving least squares (IMLS) methods. For simplicity, applications of these methods are restricted to two 1-D test cases: a Morse oscillator and a 1-D slice of the potential energy surface. For these two test cases, we systematically examine the effect of parameters in the weight function (intrinsic to IMLS methods),...