A rapid method for the preparation of ultrapure, functional lysosomes using functionalized superparamagnetic iron oxide nanoparticles.

Science.gov (United States)

Walker, Mathew W; Lloyd-Evans, Emyr

2015-01-01

Lysosomes are an emerging and increasingly important cellular organelle. With every passing year, more novel proteins and key cellular functions are associated with lysosomes. Despite this, the methodologies for their purification have largely remained unchanged since the days of their discovery. With little advancement in this area, it is no surprise that analysis of lysosomal function has been somewhat stymied, largely in part by the change in buoyant densities that occur under conditions where lysosomes accumulate macromolecules. Such phenotypes are often associated with the lysosomal storage diseases but are increasingly being observed under conditions where lysosomal proteins or, in some cases, cellular functions associated with lysosomal proteins are being manipulated. These altered lysosomes poise a problem to the classical methods to purify lysosomes that are reliant largely on their correct sedimentation by density gradient centrifugation. Building upon a technique developed by others to purify lysosomes magnetically, we have developed a unique assay using superparamagnetic iron oxide nanoparticles (SPIONs) to purify high yields of ultrapure functional lysosomes from multiple cell types including the lysosomal storage disorders. Here we describe this method in detail, including the rationale behind using SPIONs, the potential pitfalls that can be avoided and the potential functional assays these lysosomes can be used for. Finally we also summarize the other methodologies and the exact reasons why magnetic purification of lysosomes is now the method of choice for lysosomal researchers. Copyright © 2015 Elsevier Inc. All rights reserved.

Functionalized Media and Methods of Making and Using Therefor

Science.gov (United States)

Huang, Yongsong (Inventor); Dillon, James (Inventor)

2017-01-01

Methods, compositions, devices and kits are provided herein for separating, scavenging, capturing or identifying a metal from a target using a medium or scaffold with a selenium-containing functional group. The medium or the scaffold including the selenium-containing functional group has affinity and specificity to metal ions or compounds having one or more metals, and efficiently separates, recovers, and scavenges of the metals from a target such as a sample, solution, suspension, or mixture.

Finding function: evaluation methods for functional genomic data

Directory of Open Access Journals (Sweden)

Barrett Daniel R

2006-07-01

Full Text Available Abstract Background Accurate evaluation of the quality of genomic or proteomic data and computational methods is vital to our ability to use them for formulating novel biological hypotheses and directing further experiments. There is currently no standard approach to evaluation in functional genomics. Our analysis of existing approaches shows that they are inconsistent and contain substantial functional biases that render the resulting evaluations misleading both quantitatively and qualitatively. These problems make it essentially impossible to compare computational methods or large-scale experimental datasets and also result in conclusions that generalize poorly in most biological applications. Results We reveal issues with current evaluation methods here and suggest new approaches to evaluation that facilitate accurate and representative characterization of genomic methods and data. Specifically, we describe a functional genomics gold standard based on curation by expert biologists and demonstrate its use as an effective means of evaluation of genomic approaches. Our evaluation framework and gold standard are freely available to the community through our website. Conclusion Proper methods for evaluating genomic data and computational approaches will determine how much we, as a community, are able to learn from the wealth of available data. We propose one possible solution to this problem here but emphasize that this topic warrants broader community discussion.

The Boundary Function Method. Fundamentals

Science.gov (United States)

Kot, V. A.

2017-03-01

The boundary function method is proposed for solving applied problems of mathematical physics in the region defined by a partial differential equation of the general form involving constant or variable coefficients with a Dirichlet, Neumann, or Robin boundary condition. In this method, the desired function is defined by a power polynomial, and a boundary function represented in the form of the desired function or its derivative at one of the boundary points is introduced. Different sequences of boundary equations have been set up with the use of differential operators. Systems of linear algebraic equations constructed on the basis of these sequences allow one to determine the coefficients of a power polynomial. Constitutive equations have been derived for initial boundary-value problems of all the main types. With these equations, an initial boundary-value problem is transformed into the Cauchy problem for the boundary function. The determination of the boundary function by its derivative with respect to the time coordinate completes the solution of the problem.

Optimising Job-Shop Functions Utilising the Score-Function Method

DEFF Research Database (Denmark)

Nielsen, Erland Hejn

2000-01-01

During the last 1-2 decades, simulation optimisation of discrete event dynamic systems (DEDS) has made considerable theoretical progress with respect to computational efficiency. The score-function (SF) method and the infinitesimal perturbation analysis (IPA) are two candidates belonging to this ......During the last 1-2 decades, simulation optimisation of discrete event dynamic systems (DEDS) has made considerable theoretical progress with respect to computational efficiency. The score-function (SF) method and the infinitesimal perturbation analysis (IPA) are two candidates belonging...... of a Job-Shop can be handled by the SF method....

Based on Penalty Function Method

Directory of Open Access Journals (Sweden)

Ishaq Baba

2015-01-01

Full Text Available The dual response surface for simultaneously optimizing the mean and variance models as separate functions suffers some deficiencies in handling the tradeoffs between bias and variance components of mean squared error (MSE. In this paper, the accuracy of the predicted response is given a serious attention in the determination of the optimum setting conditions. We consider four different objective functions for the dual response surface optimization approach. The essence of the proposed method is to reduce the influence of variance of the predicted response by minimizing the variability relative to the quality characteristics of interest and at the same time achieving the specific target output. The basic idea is to convert the constraint optimization function into an unconstraint problem by adding the constraint to the original objective function. Numerical examples and simulations study are carried out to compare performance of the proposed method with some existing procedures. Numerical results show that the performance of the proposed method is encouraging and has exhibited clear improvement over the existing approaches.

Doubly stochastic radial basis function methods

Science.gov (United States)

Yang, Fenglian; Yan, Liang; Ling, Leevan

2018-06-01

We propose a doubly stochastic radial basis function (DSRBF) method for function recoveries. Instead of a constant, we treat the RBF shape parameters as stochastic variables whose distribution were determined by a stochastic leave-one-out cross validation (LOOCV) estimation. A careful operation count is provided in order to determine the ranges of all the parameters in our methods. The overhead cost for setting up the proposed DSRBF method is O (n2) for function recovery problems with n basis. Numerical experiments confirm that the proposed method not only outperforms constant shape parameter formulation (in terms of accuracy with comparable computational cost) but also the optimal LOOCV formulation (in terms of both accuracy and computational cost).

Time-domain Green's Function Method for three-dimensional nonlinear subsonic flows

Science.gov (United States)

Tseng, K.; Morino, L.

1978-01-01

The Green's Function Method for linearized 3D unsteady potential flow (embedded in the computer code SOUSSA P) is extended to include the time-domain analysis as well as the nonlinear term retained in the transonic small disturbance equation. The differential-delay equations in time, as obtained by applying the Green's Function Method (in a generalized sense) and the finite-element technique to the transonic equation, are solved directly in the time domain. Comparisons are made with both linearized frequency-domain calculations and existing nonlinear results.

Exp-function method for solving Maccari's system

International Nuclear Information System (INIS)

Zhang Sheng

2007-01-01

In this Letter, the Exp-function method is used to seek exact solutions of Maccari's system. As a result, single and combined generalized solitonary solutions are obtained, from which some known solutions obtained by extended sine-Gordon equation method and improved hyperbolic function method are recovered as special cases. It is shown that the Exp-function method provides a very effective and powerful mathematical tool for solving nonlinear evolution equations in mathematical physics

Water hammer prediction and control: the Green's function method

Science.gov (United States)

Xuan, Li-Jun; Mao, Feng; Wu, Jie-Zhi

2012-04-01

By Green's function method we show that the water hammer (WH) can be analytically predicted for both laminar and turbulent flows (for the latter, with an eddy viscosity depending solely on the space coordinates), and thus its hazardous effect can be rationally controlled and minimized. To this end, we generalize a laminar water hammer equation of Wang et al. (J. Hydrodynamics, B2, 51, 1995) to include arbitrary initial condition and variable viscosity, and obtain its solution by Green's function method. The predicted characteristic WH behaviors by the solutions are in excellent agreement with both direct numerical simulation of the original governing equations and, by adjusting the eddy viscosity coefficient, experimentally measured turbulent flow data. Optimal WH control principle is thereby constructed and demonstrated.

Membrane for distillation including nanostructures, methods of making membranes, and methods of desalination and separation

KAUST Repository

Lai, Zhiping; Huang, Kuo-Wei; Chen, Wei

2016-01-01

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure provide membranes, methods of making the membrane, systems including the membrane, methods of separation, methods of desalination, and the like.

Membrane for distillation including nanostructures, methods of making membranes, and methods of desalination and separation

KAUST Repository

Lai, Zhiping

2016-01-21

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure provide membranes, methods of making the membrane, systems including the membrane, methods of separation, methods of desalination, and the like.

A predator-prey model with a holling type I functional response including a predator mutual interference

Science.gov (United States)

Seo, G.; DeAngelis, D.L.

2011-01-01

The most widely used functional response in describing predator-prey relationships is the Holling type II functional response, where per capita predation is a smooth, increasing, and saturating function of prey density. Beddington and DeAngelis modified the Holling type II response to include interference of predators that increases with predator density. Here we introduce a predator-interference term into a Holling type I functional response. We explain the ecological rationale for the response and note that the phase plane configuration of the predator and prey isoclines differs greatly from that of the Beddington-DeAngelis response; for example, in having three possible interior equilibria rather than one. In fact, this new functional response seems to be quite unique. We used analytical and numerical methods to show that the resulting system shows a much richer dynamical behavior than the Beddington-DeAngelis response, or other typically used functional responses. For example, cyclic-fold, saddle-fold, homoclinic saddle connection, and multiple crossing bifurcations can all occur. We then use a smooth approximation to the Holling type I functional response with predator mutual interference to show that these dynamical properties do not result from the lack of smoothness, but rather from subtle differences in the functional responses. ?? 2011 Springer Science+Business Media, LLC.

Association between functional performance and executive cognitive functions in an elderly population including patients with low ankle–brachial index

Directory of Open Access Journals (Sweden)

Ferreira NV

2015-05-01

Full Text Available Naomi Vidal Ferreira,1 Paulo Jannuzzi Cunha,2 Danielle Irigoyen da Costa,3 Fernando dos Santos,1 Fernando Oliveira Costa,1 Fernanda Consolim-Colombo,4 Maria Cláudia Irigoyen1 1Heart Institute, Medical School, Universidade de São Paulo, São Paulo, SP, Brazil; 2Neuroimaging in Psychiatry Laboratory, Department of Psychiatry, Medical School, Universidade de São Paulo, São Paulo, SP, Brazil; 3Rio Grande do Sul Cardiology Institute, Fundação Universitária de Cardiologia, Porto Alegre, RS, Brazil; 4Medical School, Universidade Nove de Julho, São Paulo, SP, Brazil Introduction: Peripheral arterial disease, as measured by the ankle–brachial index (ABI, is prevalent among the elderly, and is associated with functional performance, assessed by the 6-minute walk test (6MWT. Executive cognitive function (ECF impairments are also prevalent in this population, but no existing study has investigated the association between ECF and functional performance in an elderly population including individuals with low ABI.Aim: To investigate the association between functional performance, as measured by the 6MWT, and loss in ECF, in an elderly sample including individuals with low ABI.Method: The ABI group was formed by 26 elderly individuals with low ABI (mean ABI: 0.63±0.19, and the control group was formed by 40 elderly individuals with normal ABI (mean ABI: 1.08±0.07. We analyzed functional performance using the 6MWT, global cognition using the Mini-Mental State Examination (MMSE, and ECF using the Digit Span for assessing attention span and working memory, the Stroop Color Word Test (SCWT for assessing information processing speed and inhibitory control/impulsivity, and the Controlled Oral Word Association Test (COWAT for assessing semantic verbal fluency and phonemic verbal fluency. We also used a factor analysis on all of the ECF tests (global ECF.Results: Before adjustment, the ABI group performed worse on global cognition, attention span, working

O-hydroxy-functionalized diamines, polymides, methods of making each, and methods of use

KAUST Repository

Ma, Xiaohua; Ghanem, Bader S.; Pinnau, Ingo

2016-01-01

Embodiments of the present disclosure provide for an ortho (o)-hydroxy-functionalized diamine, a method of making an o-hydroxy-functionalized diamine, an o-hydroxy-functionalized diamine-based polyimide, a method of making an o-hydroxy-functionalized diamine imide, methods of gas separation, and the like.

O-hydroxy-functionalized diamines, polymides, methods of making each, and methods of use

KAUST Repository

Ma, Xiaohua

2016-01-21

Embodiments of the present disclosure provide for an ortho (o)-hydroxy-functionalized diamine, a method of making an o-hydroxy-functionalized diamine, an o-hydroxy-functionalized diamine-based polyimide, a method of making an o-hydroxy-functionalized diamine imide, methods of gas separation, and the like.

Development of thermal stress screening method. Application of green function method

International Nuclear Information System (INIS)

Furuhashi, Ichiro; Shibamoto, Hiroshi; Kasahara, Naoto

2004-01-01

This work was achieved for the development of the screening method of thermal transient stresses in FBR components. We proposed an approximation method for evaluations of thermal stress under variable heat transfer coefficients (non-linear problems) using the Green functions of thermal stresses with constant heat transfer coefficients (linear problems). Detailed thermal stress analyses provided Green functions for a skirt structure and a tube-sheet of Intermediate Heat Exchanger. The upper bound Green functions were obtained by the analyses using those upper bound heat transfer coefficients. The medium and the lower bound Green functions were got by the analyses of those under medium and the lower bound heat transfer coefficients. Conventional evaluations utilized the upper bound Green functions. On the other hand, we proposed a new evaluation method by using the upper bound, medium and the lower bound Green functions. The comparison of above results gave the results as follows. The conventional evaluations were conservative and appropriate for the cases under one fluid thermal transient structure such as the skirt. The conventional evaluations were generally conservative for the complicated structures under two or more fluids thermal transients such as the tube-sheet. But the danger locations could exists for the complicated structures under two or more fluids transients, namely the conventional evaluations were non-conservative. The proposed evaluations gave good estimations for these complicated structures. Though above results, we have made the basic documents of the screening method of thermal transient stresses using the conventional method and the new method. (author)

Functional geometric method for solving free boundary problems for harmonic functions

Energy Technology Data Exchange (ETDEWEB)

Demidov, Aleksander S [M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

2010-01-01

A survey is given of results and approaches for a broad spectrum of free boundary problems for harmonic functions of two variables. The main results are obtained by the functional geometric method. The core of these methods is an interrelated analysis of the functional and geometric characteristics of the problems under consideration and of the corresponding non-linear Riemann-Hilbert problems. An extensive list of open questions is presented. Bibliography: 124 titles.

Application of numerical methods to the determination of molecular wave functions

International Nuclear Information System (INIS)

Douady, Jerome

1969-01-01

A simplified SCF Method is developed. The wave function of molecular systems and spin densities in the case of free radicals are computed from geometrical data. This method, including at the beginning a delocalization of electrons over all the molecular system, two methods which clear out bonding and anti-bonding interactions have been studied and programmed: a) overlap population analysis, b) localisation of molecular orbitals. These methods have been carried out in the case of organic compounds and free radicals. (author) [fr

Improving protein function prediction methods with integrated literature data

Directory of Open Access Journals (Sweden)

Gabow Aaron P

2008-04-01

Full Text Available Abstract Background Determining the function of uncharacterized proteins is a major challenge in the post-genomic era due to the problem's complexity and scale. Identifying a protein's function contributes to an understanding of its role in the involved pathways, its suitability as a drug target, and its potential for protein modifications. Several graph-theoretic approaches predict unidentified functions of proteins by using the functional annotations of better-characterized proteins in protein-protein interaction networks. We systematically consider the use of literature co-occurrence data, introduce a new method for quantifying the reliability of co-occurrence and test how performance differs across species. We also quantify changes in performance as the prediction algorithms annotate with increased specificity. Results We find that including information on the co-occurrence of proteins within an abstract greatly boosts performance in the Functional Flow graph-theoretic function prediction algorithm in yeast, fly and worm. This increase in performance is not simply due to the presence of additional edges since supplementing protein-protein interactions with co-occurrence data outperforms supplementing with a comparably-sized genetic interaction dataset. Through the combination of protein-protein interactions and co-occurrence data, the neighborhood around unknown proteins is quickly connected to well-characterized nodes which global prediction algorithms can exploit. Our method for quantifying co-occurrence reliability shows superior performance to the other methods, particularly at threshold values around 10% which yield the best trade off between coverage and accuracy. In contrast, the traditional way of asserting co-occurrence when at least one abstract mentions both proteins proves to be the worst method for generating co-occurrence data, introducing too many false positives. Annotating the functions with greater specificity is harder

Method for estimating modulation transfer function from sample images.

Science.gov (United States)

Saiga, Rino; Takeuchi, Akihisa; Uesugi, Kentaro; Terada, Yasuko; Suzuki, Yoshio; Mizutani, Ryuta

2018-02-01

The modulation transfer function (MTF) represents the frequency domain response of imaging modalities. Here, we report a method for estimating the MTF from sample images. Test images were generated from a number of images, including those taken with an electron microscope and with an observation satellite. These original images were convolved with point spread functions (PSFs) including those of circular apertures. The resultant test images were subjected to a Fourier transformation. The logarithm of the squared norm of the Fourier transform was plotted against the squared distance from the origin. Linear correlations were observed in the logarithmic plots, indicating that the PSF of the test images can be approximated with a Gaussian. The MTF was then calculated from the Gaussian-approximated PSF. The obtained MTF closely coincided with the MTF predicted from the original PSF. The MTF of an x-ray microtomographic section of a fly brain was also estimated with this method. The obtained MTF showed good agreement with the MTF determined from an edge profile of an aluminum test object. We suggest that this approach is an alternative way of estimating the MTF, independently of the image type. Copyright © 2017 Elsevier Ltd. All rights reserved.

Green close-quote s function method with energy-independent vertex functions

International Nuclear Information System (INIS)

Tsay Tzeng, S.Y.; Kuo, T.T.; Tzeng, Y.; Geyer, H.B.; Navratil, P.

1996-01-01

In conventional Green close-quote s function methods the vertex function Γ is generally energy dependent. However, a model-space Green close-quote s function method where the vertex function is manifestly energy independent can be formulated using energy-independent effective interaction theories based on folded diagrams and/or similarity transformations. This is discussed in general and then illustrated for a 1p1h model-space Green close-quote s function applied to a solvable Lipkin many-fermion model. The poles of the conventional Green close-quote s function are obtained by solving a self-consistent Dyson equation and model space calculations may lead to unphysical poles. For the energy-independent model-space Green close-quote s function only the physical poles of the model problem are reproduced and are in satisfactory agreement with the exact excitation energies. copyright 1996 The American Physical Society

The multifacet graphically contracted function method. I. Formulation and implementation

International Nuclear Information System (INIS)

Shepard, Ron; Brozell, Scott R.; Gidofalvi, Gergely

2014-01-01

The basic formulation for the multifacet generalization of the graphically contracted function (MFGCF) electronic structure method is presented. The analysis includes the discussion of linear dependency and redundancy of the arc factor parameters, the computation of reduced density matrices, Hamiltonian matrix construction, spin-density matrix construction, the computation of optimization gradients for single-state and state-averaged calculations, graphical wave function analysis, and the efficient computation of configuration state function and Slater determinant expansion coefficients. Timings are given for Hamiltonian matrix element and analytic optimization gradient computations for a range of model problems for full-CI Shavitt graphs, and it is observed that both the energy and the gradient computation scale as O(N 2 n 4 ) for N electrons and n orbitals. The important arithmetic operations are within dense matrix-matrix product computational kernels, resulting in a computationally efficient procedure. An initial implementation of the method is used to present applications to several challenging chemical systems, including N 2 dissociation, cubic H 8 dissociation, the symmetric dissociation of H 2 O, and the insertion of Be into H 2 . The results are compared to the exact full-CI values and also to those of the previous single-facet GCF expansion form

The multifacet graphically contracted function method. I. Formulation and implementation

Science.gov (United States)

Shepard, Ron; Gidofalvi, Gergely; Brozell, Scott R.

2014-08-01

The basic formulation for the multifacet generalization of the graphically contracted function (MFGCF) electronic structure method is presented. The analysis includes the discussion of linear dependency and redundancy of the arc factor parameters, the computation of reduced density matrices, Hamiltonian matrix construction, spin-density matrix construction, the computation of optimization gradients for single-state and state-averaged calculations, graphical wave function analysis, and the efficient computation of configuration state function and Slater determinant expansion coefficients. Timings are given for Hamiltonian matrix element and analytic optimization gradient computations for a range of model problems for full-CI Shavitt graphs, and it is observed that both the energy and the gradient computation scale as O(N2n4) for N electrons and n orbitals. The important arithmetic operations are within dense matrix-matrix product computational kernels, resulting in a computationally efficient procedure. An initial implementation of the method is used to present applications to several challenging chemical systems, including N2 dissociation, cubic H8 dissociation, the symmetric dissociation of H2O, and the insertion of Be into H2. The results are compared to the exact full-CI values and also to those of the previous single-facet GCF expansion form.

Unsteady panel method for complex configurations including wake modeling

CSIR Research Space (South Africa)

Van Zyl, Lourens H

2008-01-01

Full Text Available implementations of the DLM are however not very versatile in terms of geometries that can be modeled. The ZONA6 code offers a versatile surface panel body model including a separated wake model, but uses a pressure panel method for lifting surfaces. This paper...

A recursive Monte Carlo method for estimating importance functions in deep penetration problems

International Nuclear Information System (INIS)

Goldstein, M.

1980-04-01

A pratical recursive Monte Carlo method for estimating the importance function distribution, aimed at importance sampling for the solution of deep penetration problems in three-dimensional systems, was developed. The efficiency of the recursive method was investigated for sample problems including one- and two-dimensional, monoenergetic and and multigroup problems, as well as for a practical deep-penetration problem with streaming. The results of the recursive Monte Carlo calculations agree fairly well with Ssub(n) results. It is concluded that the recursive Monte Carlo method promises to become a universal method for estimating the importance function distribution for the solution of deep-penetration problems, in all kinds of systems: for many systems the recursive method is likely to be more efficient than previously existing methods; for three-dimensional systems it is the first method that can estimate the importance function with the accuracy required for an efficient solution based on importance sampling of neutron deep-penetration problems in those systems

Direct fragmentation of quarkonia including Fermi motion using light-cone wave function

Energy Technology Data Exchange (ETDEWEB)

Nobary, M.A. Gomshi [Razi University, Department of Physics, Faculty of Science, Kermanshah (Iran); A.E.O.I., Center for Theoretical Physics and Mathematics, Tehran (Iran); Javadi, B. [Razi University, Department of Physics, Faculty of Science, Kermanshah (Iran)

2005-07-01

We investigate the effect of Fermi motion on the direct fragmentation of the J/{psi} and {upsilon} states employing a light-cone wave function. Consistent with such a wave function we set up the kinematics of a heavy quark fragmenting into quarkonia such that the Fermi motion of the constituents splits into a longitudinal as well as a transverse direction and thus calculate the fragmentation functions for these states. In the framework of our investigation, we estimate that the fragmentation probabilities of J/{psi} and {upsilon} may increase at least up to 14 percent when including this degree of freedom. (orig.)

BLUES function method in computational physics

Science.gov (United States)

Indekeu, Joseph O.; Müller-Nedebock, Kristian K.

2018-04-01

We introduce a computational method in physics that goes ‘beyond linear use of equation superposition’ (BLUES). A BLUES function is defined as a solution of a nonlinear differential equation (DE) with a delta source that is at the same time a Green’s function for a related linear DE. For an arbitrary source, the BLUES function can be used to construct an exact solution to the nonlinear DE with a different, but related source. Alternatively, the BLUES function can be used to construct an approximate piecewise analytical solution to the nonlinear DE with an arbitrary source. For this alternative use the related linear DE need not be known. The method is illustrated in a few examples using analytical calculations and numerical computations. Areas for further applications are suggested.

Density-functional expansion methods: Grand challenges.

Science.gov (United States)

Giese, Timothy J; York, Darrin M

2012-03-01

We discuss the source of errors in semiempirical density functional expansion (VE) methods. In particular, we show that VE methods are capable of well-reproducing their standard Kohn-Sham density functional method counterparts, but suffer from large errors upon using one or more of these approximations: the limited size of the atomic orbital basis, the Slater monopole auxiliary basis description of the response density, and the one- and two-body treatment of the core-Hamiltonian matrix elements. In the process of discussing these approximations and highlighting their symptoms, we introduce a new model that supplements the second-order density-functional tight-binding model with a self-consistent charge-dependent chemical potential equalization correction; we review our recently reported method for generalizing the auxiliary basis description of the atomic orbital response density; and we decompose the first-order potential into a summation of additive atomic components and many-body corrections, and from this examination, we provide new insights and preliminary results that motivate and inspire new approximate treatments of the core-Hamiltonian.

Wada-test, functional magnetic resonance imaging and direct electrical stimulation - brain mapping methods

International Nuclear Information System (INIS)

Minkin, K.; Tanova, R.; Busarski, A.; Penkov, M.; Penev, L.; Hadjidekov, V.

2009-01-01

Modern neurosurgery requires accurate preoperative and intraoperative localization of brain pathologies but also of brain functions. The presence of individual variations in healthy subjects and the shift of brain functions in brain diseases provoke the introduction of various methods for brain mapping. The aim of this paper was to analyze the most widespread methods for brain mapping: Wada-test, functional magnetic resonance imaging (fMRI) and intraoperative direct electrical stimulation (DES). This study included 4 patients with preoperative brain mapping using Wada-test and fMRI. Intraoperative mapping with DES during awake craniotomy was performed in one case. The histopathological diagnosis was low-grade glioma in 2 cases, cortical dysplasia (1 patient) and arteriovenous malformation (1 patient). The brain mapping permits total lesion resection in three of four patients. There was no new postoperative deficit despite surgery near or within functional brain areas. Brain plasticity provoking shift of eloquent areas from their usual locations was observed in two cases. The brain mapping methods allow surgery in eloquent brain areas recognized in the past as 'forbidden areas'. Each method has advantages and disadvantages. The precise location of brain functions and pathologies frequently requires combination of different brain mapping methods. (authors)

Catalyst support structure, catalyst including the structure, reactor including a catalyst, and methods of forming same

Science.gov (United States)

Van Norman, Staci A.; Aston, Victoria J.; Weimer, Alan W.

2017-05-09

Structures, catalysts, and reactors suitable for use for a variety of applications, including gas-to-liquid and coal-to-liquid processes and methods of forming the structures, catalysts, and reactors are disclosed. The catalyst material can be deposited onto an inner wall of a microtubular reactor and/or onto porous tungsten support structures using atomic layer deposition techniques.

Taylor-series method for four-nucleon wave functions

International Nuclear Information System (INIS)

Sandulescu, A.; Tarnoveanu, I.; Rizea, M.

1977-09-01

Taylor-series method for transforming the infinite or finite well two-nucleon wave functions from individual coordinates to relative and c.m. coordinates, by expanding the single particle shell model wave functions around c.m. of the system, is generalized to four-nucleon wave functions. Also the connections with the Talmi-Moshinsky method for two and four harmonic oscillator wave functions are deduced. For both methods Fortran IV programs for the expansion coefficients have been written and the equivalence of corresponding expressions numerically proved. (author)

Temporal quadratic expansion nodal Green's function method

International Nuclear Information System (INIS)

Liu Cong; Jing Xingqing; Xu Xiaolin

2000-01-01

A new approach is presented to efficiently solve the three-dimensional space-time reactor dynamics equation which overcomes the disadvantages of current methods. In the Temporal Quadratic Expansion Nodal Green's Function Method (TQE/NGFM), the Quadratic Expansion Method (QEM) is used for the temporal solution with the Nodal Green's Function Method (NGFM) employed for the spatial solution. Test calculational results using TQE/NGFM show that its time step size can be 5-20 times larger than that of the Fully Implicit Method (FIM) for similar precision. Additionally, the spatial mesh size with NGFM can be nearly 20 times larger than that using the finite difference method. So, TQE/NGFM is proved to be an efficient reactor dynamics analysis method

Simulation of ecological processes using response functions method

International Nuclear Information System (INIS)

Malkina-Pykh, I.G.; Pykh, Yu. A.

1998-01-01

The article describes further development and applications of the already well-known response functions method (MRF). The method is used as a basis for the development of mathematical models of a wide set of ecological processes. The model of radioactive contamination of the ecosystems is chosen as an example. The mathematical model was elaborated for the description of 90 Sr dynamics in the elementary ecosystems of various geographical zones. The model includes the blocks corresponding with the main units of any elementary ecosystem: lower atmosphere, soil, vegetation, surface water. Parameters' evaluation was provided on a wide set of experimental data. A set of computer simulations was done on the model to prove the possibility of the model's use for ecological forecasting

Including screening in van der Waals corrected density functional theory calculations: The case of atoms and small molecules physisorbed on graphene

Energy Technology Data Exchange (ETDEWEB)

Silvestrelli, Pier Luigi; Ambrosetti, Alberto [Dipartimento di Fisica e Astronomia, Università di Padova, via Marzolo 8, I–35131 Padova, Italy and DEMOCRITOS National Simulation Center of the Italian Istituto Officina dei Materiali (IOM) of the Italian National Research Council (CNR), Trieste (Italy)

2014-03-28

The Density Functional Theory (DFT)/van der Waals-Quantum Harmonic Oscillator-Wannier function (vdW-QHO-WF) method, recently developed to include the vdW interactions in approximated DFT by combining the quantum harmonic oscillator model with the maximally localized Wannier function technique, is applied to the cases of atoms and small molecules (X=Ar, CO, H{sub 2}, H{sub 2}O) weakly interacting with benzene and with the ideal planar graphene surface. Comparison is also presented with the results obtained by other DFT vdW-corrected schemes, including PBE+D, vdW-DF, vdW-DF2, rVV10, and by the simpler Local Density Approximation (LDA) and semilocal generalized gradient approximation approaches. While for the X-benzene systems all the considered vdW-corrected schemes perform reasonably well, it turns out that an accurate description of the X-graphene interaction requires a proper treatment of many-body contributions and of short-range screening effects, as demonstrated by adopting an improved version of the DFT/vdW-QHO-WF method. We also comment on the widespread attitude of relying on LDA to get a rough description of weakly interacting systems.

Improved quasi-static nodal green's function method

International Nuclear Information System (INIS)

Li Junli; Jing Xingqing; Hu Dapu

1997-01-01

Improved Quasi-Static Green's Function Method (IQS/NGFM) is presented, as an new kinetic method. To solve the three-dimensional transient problem, improved Quasi-Static Method is adopted to deal with the temporal problem, which will increase the time step as long as possible so as to decrease the number of times of space calculation. The time step of IQS/NGFM can be increased to 5∼10 times longer than that of Full Implicit Differential Method. In spatial calculation, the NGFM is used to get the distribution of shape function, and it's spatial mesh can be nearly 20 times larger than that of Definite Differential Method. So the IQS/NGFM is considered as an efficient kinetic method

Relationships between the generalized functional method and other methods of nonimaging optical design.

Science.gov (United States)

Bortz, John; Shatz, Narkis

2011-04-01

The recently developed generalized functional method provides a means of designing nonimaging concentrators and luminaires for use with extended sources and receivers. We explore the mathematical relationships between optical designs produced using the generalized functional method and edge-ray, aplanatic, and simultaneous multiple surface (SMS) designs. Edge-ray and dual-surface aplanatic designs are shown to be special cases of generalized functional designs. In addition, it is shown that dual-surface SMS designs are closely related to generalized functional designs and that certain computational advantages accrue when the two design methods are combined. A number of examples are provided. © 2011 Optical Society of America

A Method for Functional Task Alignment Analysis of an Arthrocentesis Simulator.

Science.gov (United States)

Adams, Reid A; Gilbert, Gregory E; Buckley, Lisa A; Nino Fong, Rodolfo; Fuentealba, I Carmen; Little, Erika L

2018-05-16

During simulation-based education, simulators are subjected to procedures composed of a variety of tasks and processes. Simulators should functionally represent a patient in response to the physical action of these tasks. The aim of this work was to describe a method for determining whether a simulator does or does not have sufficient functional task alignment (FTA) to be used in a simulation. Potential performance checklist items were gathered from published arthrocentesis guidelines and aggregated into a performance checklist using Lawshe's method. An expert panel used this performance checklist and an FTA analysis questionnaire to evaluate a simulator's ability to respond to the physical actions required by the performance checklist. Thirteen items, from a pool of 39, were included on the performance checklist. Experts had mixed reviews of the simulator's FTA and its suitability for use in simulation. Unexpectedly, some positive FTA was found for several tasks where the simulator lacked functionality. By developing a detailed list of specific tasks required to complete a clinical procedure, and surveying experts on the simulator's response to those actions, educators can gain insight into the simulator's clinical accuracy and suitability. Unexpected of positive FTA ratings of function deficits suggest that further revision of the survey method is required.

Quasiaverages, symmetry breaking and irreducible Green functions method

Directory of Open Access Journals (Sweden)

A.L.Kuzemsky

2010-01-01

Full Text Available The development and applications of the method of quasiaverages to quantum statistical physics and to quantum solid state theory and, in particular, to quantum theory of magnetism, were considered. It was shown that the role of symmetry (and the breaking of symmetries in combination with the degeneracy of the system was reanalyzed and essentially clarified within the framework of the method of quasiaverages. The problem of finding the ferromagnetic, antiferromagnetic and superconducting "symmetry broken" solutions of the correlated lattice fermion models was discussed within the irreducible Green functions method. A unified scheme for the construction of generalized mean fields (elastic scattering corrections and self-energy (inelastic scattering in terms of the equations of motion and Dyson equation was generalized in order to include the "source fields". This approach complements previous studies of microscopic theory of antiferromagnetism and clarifies the concepts of Neel sublattices for localized and itinerant antiferromagnetism and "spin-aligning fields" of correlated lattice fermions.

A functional U-statistic method for association analysis of sequencing data.

Science.gov (United States)

Jadhav, Sneha; Tong, Xiaoran; Lu, Qing

2017-11-01

Although sequencing studies hold great promise for uncovering novel variants predisposing to human diseases, the high dimensionality of the sequencing data brings tremendous challenges to data analysis. Moreover, for many complex diseases (e.g., psychiatric disorders) multiple related phenotypes are collected. These phenotypes can be different measurements of an underlying disease, or measurements characterizing multiple related diseases for studying common genetic mechanism. Although jointly analyzing these phenotypes could potentially increase the power of identifying disease-associated genes, the different types of phenotypes pose challenges for association analysis. To address these challenges, we propose a nonparametric method, functional U-statistic method (FU), for multivariate analysis of sequencing data. It first constructs smooth functions from individuals' sequencing data, and then tests the association of these functions with multiple phenotypes by using a U-statistic. The method provides a general framework for analyzing various types of phenotypes (e.g., binary and continuous phenotypes) with unknown distributions. Fitting the genetic variants within a gene using a smoothing function also allows us to capture complexities of gene structure (e.g., linkage disequilibrium, LD), which could potentially increase the power of association analysis. Through simulations, we compared our method to the multivariate outcome score test (MOST), and found that our test attained better performance than MOST. In a real data application, we apply our method to the sequencing data from Minnesota Twin Study (MTS) and found potential associations of several nicotine receptor subunit (CHRN) genes, including CHRNB3, associated with nicotine dependence and/or alcohol dependence. © 2017 WILEY PERIODICALS, INC.

An efficient and accurate method to obtain the energy-dependent Green function for general potentials

International Nuclear Information System (INIS)

Kramer, T; Heller, E J; Parrott, R E

2008-01-01

Time-dependent quantum mechanics provides an intuitive picture of particle propagation in external fields. Semiclassical methods link the classical trajectories of particles with their quantum mechanical propagation. Many analytical results and a variety of numerical methods have been developed to solve the time-dependent Schroedinger equation. The time-dependent methods work for nearly arbitrarily shaped potentials, including sources and sinks via complex-valued potentials. Many quantities are measured at fixed energy, which is seemingly not well suited for a time-dependent formulation. Very few methods exist to obtain the energy-dependent Green function for complicated potentials without resorting to ensemble averages or using certain lead-in arrangements. Here, we demonstrate in detail a time-dependent approach, which can accurately and effectively construct the energy-dependent Green function for very general potentials. The applications of the method are numerous, including chemical, mesoscopic, and atomic physics

Second-principles method for materials simulations including electron and lattice degrees of freedom

Science.gov (United States)

García-Fernández, Pablo; Wojdeł, Jacek C.; Íñiguez, Jorge; Junquera, Javier

2016-05-01

We present a first-principles-based (second-principles) scheme that permits large-scale materials simulations including both atomic and electronic degrees of freedom on the same footing. The method is based on a predictive quantum-mechanical theory—e.g., density functional theory—and its accuracy can be systematically improved at a very modest computational cost. Our approach is based on dividing the electron density of the system into a reference part—typically corresponding to the system's neutral, geometry-dependent ground state—and a deformation part—defined as the difference between the actual and reference densities. We then take advantage of the fact that the bulk part of the system's energy depends on the reference density alone; this part can be efficiently and accurately described by a force field, thus avoiding explicit consideration of the electrons. Then, the effects associated to the difference density can be treated perturbatively with good precision by working in a suitably chosen Wannier function basis. Further, the electronic model can be restricted to the bands of interest. All these features combined yield a very flexible and computationally very efficient scheme. Here we present the basic formulation of this approach, as well as a practical strategy to compute model parameters for realistic materials. We illustrate the accuracy and scope of the proposed method with two case studies, namely, the relative stability of various spin arrangements in NiO (featuring complex magnetic interactions in a strongly-correlated oxide) and the formation of a two-dimensional electron gas at the interface between band insulators LaAlO3 and SrTiO3 (featuring subtle electron-lattice couplings and screening effects). We conclude by discussing ways to overcome the limitations of the present approach (most notably, the assumption of a fixed bonding topology), as well as its many envisioned possibilities and future extensions.

Linear regression methods a ccording to objective functions

OpenAIRE

Yasemin Sisman; Sebahattin Bektas

2012-01-01

The aim of the study is to explain the parameter estimation methods and the regression analysis. The simple linear regressionmethods grouped according to the objective function are introduced. The numerical solution is achieved for the simple linear regressionmethods according to objective function of Least Squares and theLeast Absolute Value adjustment methods. The success of the appliedmethods is analyzed using their objective function values.

Methods for deconvolving sparse positive delta function series

International Nuclear Information System (INIS)

Trussell, H.J.; Schwalbe, L.A.

1981-01-01

Sparse delta function series occur as data in many chemical analyses and seismic methods. These original data are often sufficiently degraded by the recording instrument response that the individual delta function peaks are difficult to distinguish and measure. A method, which has been used to measure these peaks, is to fit a parameterized model by a nonlinear least-squares fitting algorithm. The deconvolution approaches described have the advantage of not requiring a parameterized point spread function, nor do they expect a fixed number of peaks. Two new methods are presented. The maximum power technique is reviewed. A maximum a posteriori technique is introduced. Results on both simulated and real data by the two methods are presented. The characteristics of the data can determine which method gives superior results. 5 figures

Convex functions and optimization methods on Riemannian manifolds

CERN Document Server

Udrişte, Constantin

1994-01-01

This unique monograph discusses the interaction between Riemannian geometry, convex programming, numerical analysis, dynamical systems and mathematical modelling. The book is the first account of the development of this subject as it emerged at the beginning of the 'seventies. A unified theory of convexity of functions, dynamical systems and optimization methods on Riemannian manifolds is also presented. Topics covered include geodesics and completeness of Riemannian manifolds, variations of the p-energy of a curve and Jacobi fields, convex programs on Riemannian manifolds, geometrical constructions of convex functions, flows and energies, applications of convexity, descent algorithms on Riemannian manifolds, TC and TP programs for calculations and plots, all allowing the user to explore and experiment interactively with real life problems in the language of Riemannian geometry. An appendix is devoted to convexity and completeness in Finsler manifolds. For students and researchers in such diverse fields as pu...

Force measuring valve assemblies, systems including such valve assemblies and related methods

Science.gov (United States)

DeWall, Kevin George [Pocatello, ID; Garcia, Humberto Enrique [Idaho Falls, ID; McKellar, Michael George [Idaho Falls, ID

2012-04-17

Methods of evaluating a fluid condition may include stroking a valve member and measuring a force acting on the valve member during the stroke. Methods of evaluating a fluid condition may include measuring a force acting on a valve member in the presence of fluid flow over a period of time and evaluating at least one of the frequency of changes in the measured force over the period of time and the magnitude of the changes in the measured force over the period of time to identify the presence of an anomaly in a fluid flow and, optionally, its estimated location. Methods of evaluating a valve condition may include directing a fluid flow through a valve while stroking a valve member, measuring a force acting on the valve member during the stroke, and comparing the measured force to a reference force. Valve assemblies and related systems are also disclosed.

Geometric optical transfer function and tis computation method

International Nuclear Information System (INIS)

Wang Qi

1992-01-01

Geometric Optical Transfer Function formula is derived after expound some content to be easily ignored, and the computation method is given with Bessel function of order zero and numerical integration and Spline interpolation. The method is of advantage to ensure accuracy and to save calculation

A novel method to solve functional differential equations

International Nuclear Information System (INIS)

Tapia, V.

1990-01-01

A method to solve differential equations containing the variational operator as the derivation operation is presented. They are called variational differential equations (VDE). The solution to a VDE should be a function containing the derivatives, with respect to the base space coordinates, of the fields up to a generic order s: a s-th-order function. The variational operator doubles the order of the function on which it acts. Therefore, in order to make compatible the orders of the different terms appearing in a VDE, the solution should be a function containing the derivatives of the fields at all orders. But this takes us again back to the functional methods. In order to avoid this, one must restrict the considerations, in the case of second-order VDEs, to the space of s-th-order functions on which the variational operator acts transitively. These functions have been characterized for a one-dimensional base space for the first- and second-order cases. These functions turn out to be polynomial in the highest-order derivatives of the fields with functions of the lower-order derivatives as coefficients. Then VDEs reduce to a system of coupled partial differential equations for the coefficients above mentioned. The importance of the method lies on the fact that the solutions to VDEs are in a one-to-one correspondence with the solutions of functional differential equations. The previous method finds direct applications in quantum field theory, where the Schroedinger equation plays a central role. Since the Schroedinger equation is reduced to a system of coupled partial differential equations, this provides a nonperturbative scheme for quantum field theory. As an example, the massless scalar field is considered

Sum rules in the response function method

International Nuclear Information System (INIS)

Takayanagi, Kazuo

1990-01-01

Sum rules in the response function method are studied in detail. A sum rule can be obtained theoretically by integrating the imaginary part of the response function over the excitation energy with a corresponding energy weight. Generally, the response function is calculated perturbatively in terms of the residual interaction, and the expansion can be described by diagrammatic methods. In this paper, we present a classification of the diagrams so as to clarify which diagram has what contribution to which sum rule. This will allow us to get insight into the contributions to the sum rules of all the processes expressed by Goldstone diagrams. (orig.)

RANDOM FUNCTIONS AND INTERVAL METHOD FOR PREDICTING THE RESIDUAL RESOURCE OF BUILDING STRUCTURES

Directory of Open Access Journals (Sweden)

Shmelev Gennadiy Dmitrievich

2017-11-01

Full Text Available Subject: possibility of using random functions and interval prediction method for estimating the residual life of building structures in the currently used buildings. Research objectives: coordination of ranges of values to develop predictions and random functions that characterize the processes being predicted. Materials and methods: when performing this research, the method of random functions and the method of interval prediction were used. Results: in the course of this work, the basic properties of random functions, including the properties of families of random functions, are studied. The coordination of time-varying impacts and loads on building structures is considered from the viewpoint of their influence on structures and representation of the structures’ behavior in the form of random functions. Several models of random functions are proposed for predicting individual parameters of structures. For each of the proposed models, its scope of application is defined. The article notes that the considered approach of forecasting has been used many times at various sites. In addition, the available results allowed the authors to develop a methodology for assessing the technical condition and residual life of building structures for the currently used facilities. Conclusions: we studied the possibility of using random functions and processes for the purposes of forecasting the residual service lives of structures in buildings and engineering constructions. We considered the possibility of using an interval forecasting approach to estimate changes in defining parameters of building structures and their technical condition. A comprehensive technique for forecasting the residual life of building structures using the interval approach is proposed.

OCOPTR, Minimization of Nonlinear Function, Variable Metric Method, Derivative Calculation. DRVOCR, Minimization of Nonlinear Function, Variable Metric Method, Derivative Calculation

International Nuclear Information System (INIS)

Nazareth, J. L.

1979-01-01

1 - Description of problem or function: OCOPTR and DRVOCR are computer programs designed to find minima of non-linear differentiable functions f: R n →R with n dimensional domains. OCOPTR requires that the user only provide function values (i.e. it is a derivative-free routine). DRVOCR requires the user to supply both function and gradient information. 2 - Method of solution: OCOPTR and DRVOCR use the variable metric (or quasi-Newton) method of Davidon (1975). For OCOPTR, the derivatives are estimated by finite differences along a suitable set of linearly independent directions. For DRVOCR, the derivatives are user- supplied. Some features of the codes are the storage of the approximation to the inverse Hessian matrix in lower trapezoidal factored form and the use of an optimally-conditioned updating method. Linear equality constraints are permitted subject to the initial Hessian factor being chosen correctly. 3 - Restrictions on the complexity of the problem: The functions to which the routine is applied are assumed to be differentiable. The routine also requires (n 2 /2) + 0(n) storage locations where n is the problem dimension

Composite materials and bodies including silicon carbide and titanium diboride and methods of forming same

Science.gov (United States)

Lillo, Thomas M.; Chu, Henry S.; Harrison, William M.; Bailey, Derek

2013-01-22

Methods of forming composite materials include coating particles of titanium dioxide with a substance including boron (e.g., boron carbide) and a substance including carbon, and reacting the titanium dioxide with the substance including boron and the substance including carbon to form titanium diboride. The methods may be used to form ceramic composite bodies and materials, such as, for example, a ceramic composite body or material including silicon carbide and titanium diboride. Such bodies and materials may be used as armor bodies and armor materials. Such methods may include forming a green body and sintering the green body to a desirable final density. Green bodies formed in accordance with such methods may include particles comprising titanium dioxide and a coating at least partially covering exterior surfaces thereof, the coating comprising a substance including boron (e.g., boron carbide) and a substance including carbon.

Initiation devices, initiation systems including initiation devices and related methods

Energy Technology Data Exchange (ETDEWEB)

Daniels, Michael A.; Condit, Reston A.; Rasmussen, Nikki; Wallace, Ronald S.

2018-04-10

Initiation devices may include at least one substrate, an initiation element positioned on a first side of the at least one substrate, and a spark gap electrically coupled to the initiation element and positioned on a second side of the at least one substrate. Initiation devices may include a plurality of substrates where at least one substrate of the plurality of substrates is electrically connected to at least one adjacent substrate of the plurality of substrates with at least one via extending through the at least one substrate. Initiation systems may include such initiation devices. Methods of igniting energetic materials include passing a current through a spark gap formed on at least one substrate of the initiation device, passing the current through at least one via formed through the at least one substrate, and passing the current through an explosive bridge wire of the initiation device.

MHCcluster, a method for functional clustering of MHC molecules

DEFF Research Database (Denmark)

Thomsen, Martin Christen Frølund; Lundegaard, Claus; Buus, Søren

2013-01-01

The identification of peptides binding to major histocompatibility complexes (MHC) is a critical step in the understanding of T cell immune responses. The human MHC genomic region (HLA) is extremely polymorphic comprising several thousand alleles, many encoding a distinct molecule. The potentially...... binding specificity. The method has a flexible web interface that allows the user to include any MHC of interest in the analysis. The output consists of a static heat map and graphical tree-based visualizations of the functional relationship between MHC variants and a dynamic TreeViewer interface where...

Numerical methods for characterization of synchrotron radiation based on the Wigner function method

Directory of Open Access Journals (Sweden)

Takashi Tanaka

2014-06-01

Full Text Available Numerical characterization of synchrotron radiation based on the Wigner function method is explored in order to accurately evaluate the light source performance. A number of numerical methods to compute the Wigner functions for typical synchrotron radiation sources such as bending magnets, undulators and wigglers, are presented, which significantly improve the computation efficiency and reduce the total computation time. As a practical example of the numerical characterization, optimization of betatron functions to maximize the brilliance of undulator radiation is discussed.

Density Functional Theory versus the Hartree-Fock Method: Comparative Assessment

International Nuclear Information System (INIS)

Amusia, M.Ya.; Shaginyan, V.R.; Msezane, A.Z.

2003-01-01

We compare two different approaches to investigations of many-electron systems. The first is the Hartree-Fock (HF) method and the second is the Density Functional Theory (DFT). Overview of the main features and peculiar properties of the HF method are presented. A way to realize the HF method within the Kohn-Sham (KS) approach of the DFT is discussed. We show that this is impossible without including a specific correlation energy, which is defined by the difference between the sum of the kinetic and exchange energies of a system considered within KS and HF, respectively. It is the nonlocal exchange potential entering the HF equations that generates this correlation energy. We show that the total correlation energy of a finite electron system, which has to include this correlation energy, cannot be obtained from considerations of uniform electron systems. The single-particle excitation spectrum of many-electron systems is related to the eigenvalues of the corresponding KS equations. We demonstrate that this spectrum does not coincide in general with the eigenvalues of KS or HF equations

Density Functional Theory versus the Hartree-Fock Method: Comparative Assessment

Energy Technology Data Exchange (ETDEWEB)

Amusia, M.Ya.; Shaginyan, V.R. [The Hebrew University, Jerusalem (Israel); Msezane, A.Z. [Clark Atlanta Univ., Atlanta, GA (United States). Center for Theoretical Studies of Physical Systems

2003-12-01

We compare two different approaches to investigations of many-electron systems. The first is the Hartree-Fock (HF) method and the second is the Density Functional Theory (DFT). Overview of the main features and peculiar properties of the HF method are presented. A way to realize the HF method within the Kohn-Sham (KS) approach of the DFT is discussed. We show that this is impossible without including a specific correlation energy, which is defined by the difference between the sum of the kinetic and exchange energies of a system considered within KS and HF, respectively. It is the nonlocal exchange potential entering the HF equations that generates this correlation energy. We show that the total correlation energy of a finite electron system, which has to include this correlation energy, cannot be obtained from considerations of uniform electron systems. The single-particle excitation spectrum of many-electron systems is related to the eigenvalues of the corresponding KS equations. We demonstrate that this spectrum does not coincide in general with the eigenvalues of KS or HF equations.

Explicit appropriate basis function method for numerical solution of stiff systems

International Nuclear Information System (INIS)

Chen, Wenzhen; Xiao, Hongguang; Li, Haofeng; Chen, Ling

2015-01-01

Highlights: • An explicit numerical method called the appropriate basis function method is presented. • The method differs from the power series method for obtaining approximate numerical solutions. • Two cases show the method is fit for linear and nonlinear stiff systems. • The method is very simple and effective for most of differential equation systems. - Abstract: In this paper, an explicit numerical method, called the appropriate basis function method, is presented. The explicit appropriate basis function method differs from the power series method because it employs an appropriate basis function such as the exponential function, or periodic function, other than a polynomial, to obtain approximate numerical solutions. The method is successful and effective for the numerical solution of the first order ordinary differential equations. Two examples are presented to show the ability of the method for dealing with linear and nonlinear systems of differential equations

Efficient methods for including quantum effects in Monte Carlo calculations of large systems: extension of the displaced points path integral method and other effective potential methods to calculate properties and distributions.

Science.gov (United States)

Mielke, Steven L; Dinpajooh, Mohammadhasan; Siepmann, J Ilja; Truhlar, Donald G

2013-01-07

We present a procedure to calculate ensemble averages, thermodynamic derivatives, and coordinate distributions by effective classical potential methods. In particular, we consider the displaced-points path integral (DPPI) method, which yields exact quantal partition functions and ensemble averages for a harmonic potential and approximate quantal ones for general potentials, and we discuss the implementation of the new procedure in two Monte Carlo simulation codes, one that uses uncorrelated samples to calculate absolute free energies, and another that employs Metropolis sampling to calculate relative free energies. The results of the new DPPI method are compared to those from accurate path integral calculations as well as to results of two other effective classical potential schemes for the case of an isolated water molecule. In addition to the partition function, we consider the heat capacity and expectation values of the energy, the potential energy, the bond angle, and the OH distance. We also consider coordinate distributions. The DPPI scheme performs best among the three effective potential schemes considered and achieves very good accuracy for all of the properties considered. A key advantage of the effective potential schemes is that they display much lower statistical sampling variances than those for accurate path integral calculations. The method presented here shows great promise for including quantum effects in calculations on large systems.

Numerical solution to generalized Burgers'-Fisher equation using Exp-function method hybridized with heuristic computation.

Science.gov (United States)

Malik, Suheel Abdullah; Qureshi, Ijaz Mansoor; Amir, Muhammad; Malik, Aqdas Naveed; Haq, Ihsanul

2015-01-01

In this paper, a new heuristic scheme for the approximate solution of the generalized Burgers'-Fisher equation is proposed. The scheme is based on the hybridization of Exp-function method with nature inspired algorithm. The given nonlinear partial differential equation (NPDE) through substitution is converted into a nonlinear ordinary differential equation (NODE). The travelling wave solution is approximated by the Exp-function method with unknown parameters. The unknown parameters are estimated by transforming the NODE into an equivalent global error minimization problem by using a fitness function. The popular genetic algorithm (GA) is used to solve the minimization problem, and to achieve the unknown parameters. The proposed scheme is successfully implemented to solve the generalized Burgers'-Fisher equation. The comparison of numerical results with the exact solutions, and the solutions obtained using some traditional methods, including adomian decomposition method (ADM), homotopy perturbation method (HPM), and optimal homotopy asymptotic method (OHAM), show that the suggested scheme is fairly accurate and viable for solving such problems.

Numerical solution to generalized Burgers'-Fisher equation using Exp-function method hybridized with heuristic computation.

Directory of Open Access Journals (Sweden)

Suheel Abdullah Malik

Full Text Available In this paper, a new heuristic scheme for the approximate solution of the generalized Burgers'-Fisher equation is proposed. The scheme is based on the hybridization of Exp-function method with nature inspired algorithm. The given nonlinear partial differential equation (NPDE through substitution is converted into a nonlinear ordinary differential equation (NODE. The travelling wave solution is approximated by the Exp-function method with unknown parameters. The unknown parameters are estimated by transforming the NODE into an equivalent global error minimization problem by using a fitness function. The popular genetic algorithm (GA is used to solve the minimization problem, and to achieve the unknown parameters. The proposed scheme is successfully implemented to solve the generalized Burgers'-Fisher equation. The comparison of numerical results with the exact solutions, and the solutions obtained using some traditional methods, including adomian decomposition method (ADM, homotopy perturbation method (HPM, and optimal homotopy asymptotic method (OHAM, show that the suggested scheme is fairly accurate and viable for solving such problems.

Method of Fusion Diagnosis for Dam Service Status Based on Joint Distribution Function of Multiple Points

Directory of Open Access Journals (Sweden)

Zhenxiang Jiang

2016-01-01

Full Text Available The traditional methods of diagnosing dam service status are always suitable for single measuring point. These methods also reflect the local status of dams without merging multisource data effectively, which is not suitable for diagnosing overall service. This study proposes a new method involving multiple points to diagnose dam service status based on joint distribution function. The function, including monitoring data of multiple points, can be established with t-copula function. Therefore, the possibility, which is an important fusing value in different measuring combinations, can be calculated, and the corresponding diagnosing criterion is established with typical small probability theory. Engineering case study indicates that the fusion diagnosis method can be conducted in real time and the abnormal point can be detected, thereby providing a new early warning method for engineering safety.

A new wall function boundary condition including heat release effect for supersonic combustion flows

International Nuclear Information System (INIS)

Gao, Zhen-Xun; Jiang, Chong-Wen; Lee, Chun-Hian

2016-01-01

Highlights: • A new wall function including heat release effect is theoretically derived. • The new wall function is a unified form holding for flows with/without combustion. • The new wall function shows good results for a supersonic combustion case. - Abstract: A new wall function boundary condition considering combustion heat release effect (denoted as CWFBC) is proposed, for efficient predictions of skin friction and heat transfer in supersonic combustion flows. Based on a standard flow model including boundary-layer combustion, the Shvab–Zeldovich coupling parameters are introduced to derive a new velocity law-of-the-wall including the influence of combustion. For the temperature law-of-the-wall, it is proposed to use the enthalpy–velocity relation, instead of the Crocco–Busemann equation, to eliminate explicit influence of chemical reactions. The obtained velocity and temperature law-of-the-walls constitute the CWFBC, which is a unified form simultaneously holding for single-species, multi-species mixing and multi-species reactive flows. The subsequent numerical simulations using this CWFBC on an experimental case indicate that the CWFBC could accurately reflect the influences on the skin friction and heat transfer by the chemical reactions and heat release, and show large improvements compared to previous WFBC. Moreover, the CWFBC can give accurate skin friction and heat flux for a coarse mesh with y"+ up to 200 for the experimental case, except for slightly larger discrepancy of the wall heat flux around ignition position.

A tutorial review of functional connectivity analysis methods and their interpretational pitfalls

Directory of Open Access Journals (Sweden)

Andre M Bastos

2016-01-01

Full Text Available Oscillatory neuronal activity may provide a mechanism for dynamic network coordination. Rhythmic neuronal interactions can be quantified using multiple metrics, each with their own advantages and disadvantages. This tutorial will review and summarize current analysis methods used in the field of invasive and non-invasive electrophysiology to study the dynamic connections between neuronal populations. First, we review metrics for functional connectivity, including coherence, phase synchronization, phase-slope index, and Granger causality, with the specific aim to provide an intuition for how these metrics work, as well as their quantitative definition. Next, we highlight a number of interpretational caveats and common pitfalls that can arise when performing functional connectivity analysis, including the common reference problem, the signal to noise ratio problem, the volume conduction problem, the common input problem, and the trial sample size bias problem. These pitfalls will be illustrated by presenting a set of MATLAB-scripts, which can be executed by the reader to simulate each of these potential problems. We discuss of how these issues can be addressed using current methods.

Method of Measuring the Coupled Lattice Functions at the Interaction Point in e sup + e sup - Storage Rings

CERN Document Server

Cai, Y

2003-01-01

We have investigate a method of measuring the complete lattice functions including the coupling parameters at any azimuthal position in a periodic an symplectic system. In particular, the method is applied to measure the lattice functions at the interaction point where the beams collide. It has been demonstrate that a complete set of lattice functions can be accurately measured with two adjacent beam position monitors and the known transformation matrix between them. As a by-product, the method also automatically measures the complete one-turn matrix.

Distal radioulnar joint: functional anatomy, including pathomechanics.

Science.gov (United States)

Haugstvedt, J R; Langer, M F; Berger, R A

2017-05-01

The distal radioulnar joint allows the human to rotate the forearm to place the hand in a desired position to perform different tasks, without interfering with the grasping function of the hand. The ulna is the stable part of the forearm around which the radius rotates; the stability of the distal radioulnar joint is provided by the interaction between ligaments, muscles and bones. The stabilizing structures are the triangular fibrocartilage complex, the ulnocarpal ligament complex, the extensor carpi ulnaris tendon and tendon sheath, the pronator quadratus, the interosseous membrane and ligament, the bone itself and the joint capsule. The purpose of this review article is to present and illustrate the current understanding of the functional anatomy and pathomechanics of this joint.

Electromagnetically induced nuclear beta decay calculated by a Green's function method

International Nuclear Information System (INIS)

Reiss, H.R.

1984-01-01

The transition probability for enhancement of forbidden nuclear beta decay by an applied plane-wave electromagnetic field is calculated in a nonrelativistic spinless approximation by a Green's function method. The calculation involves a stationary-phase approximation. The stationary phase points in the presence of an intense field are located in very different positions than they are in the field-free case. In order-of-magnitude terms, the results are completely consistent with an earlier, much more complete wave-function calculation which includes spin and relativistic effects. Both the present Green's function calculation and the earlier wave function calculation give electromagnetic contributions in first-forbidden nuclear beta decay matrix elements which are of order (R 0 /lambda-dash-bar/sub C/) 2 with respect to allowed decays, where R 0 is the nuclear radius and lambda-dash-bar/sub C/ is the electron Compton wavelength

A Numerical Method for Lane-Emden Equations Using Hybrid Functions and the Collocation Method

Directory of Open Access Journals (Sweden)

Changqing Yang

2012-01-01

Full Text Available A numerical method to solve Lane-Emden equations as singular initial value problems is presented in this work. This method is based on the replacement of unknown functions through a truncated series of hybrid of block-pulse functions and Chebyshev polynomials. The collocation method transforms the differential equation into a system of algebraic equations. It also has application in a wide area of differential equations. Corresponding numerical examples are presented to demonstrate the accuracy of the proposed method.

Accelerometer method and apparatus for integral display and control functions

Science.gov (United States)

Bozeman, Richard J., Jr.

1992-06-01

Vibration analysis has been used for years to provide a determination of the proper functioning of different types of machinery, including rotating machinery and rocket engines. A determination of a malfunction, if detected at a relatively early stage in its development, will allow changes in operating mode or a sequenced shutdown of the machinery prior to a total failure. Such preventative measures result in less extensive and/or less expensive repairs, and can also prevent a sometimes catastrophic failure of equipment. Standard vibration analyzers are generally rather complex, expensive, and of limited portability. They also usually result in displays and controls being located remotely from the machinery being monitored. Consequently, a need exists for improvements in accelerometer electronic display and control functions which are more suitable for operation directly on machines and which are not so expensive and complex. The invention includes methods and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. The apparatus includes an accelerometer package having integral display and control functions. The accelerometer package is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine condition over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase over the selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated. The benefits of a vibration recording and monitoring system with controls and displays readily

Method of hyperspherical functions in a few-body quantum mechanics

International Nuclear Information System (INIS)

Dzhibuti, R.I.; Krupennikova, N.B.

1984-01-01

A new method for solving a few-body problem in quantum mechanics based on the expansion of the wave function of many-particle system in terms of basis hyperspherical functions is outlined in the monograph. This method gives the possibility to obtain important results in nuclear physics. A materials of general character is presented which can be useful when considering a few-body problem in atomic and molecular physics as well as in elementary particle physics. The paper deals with the theory of hyperspherical functions and the method of expansion in terms of hyperspherical functions basis can be formally considered as a certain generalization of the partial expansion method in the two-body problem. The Raynal-Revai theory is stated for the three-body problem and coe-- fficients of unitary transformations for four-particle hyperspherical function coefficients are introduced. Five-particle hyperspherical functions are introduced and an attempt of generalization of the theory for the systems With any number of particles has been made. The rules of plotting symmetrized hyperspherical functions for three and four identical particles are given. Also described is the method of expansion in terms of hyperspherical functions basis in the coordinate and impulse representations for discrete and continuous spectrum, respectively

Multiquark masses and wave functions through modified Green's function Monte Carlo method

International Nuclear Information System (INIS)

Kerbikov, B.O.; Polikarpov, M.I.; Shevchenko, L.V.

1987-01-01

The Modified Green's function Monte Carlo method (MGFMC) is used to calculate the masses and ground-state wave functions of multiquark systems in the potential model. The previously developed MGFMC is generalized in order to treat systems containing quarks with inequal masses. The obtained results are presented with the Cornell potential for the masses and the wave functions of light and heavy flavoured baryons and multiquark states (N=6, 9, 12) made of light quarks

Some Supplementary Methods for the Analysis of the Delis-Kaplan Executive Function System

Science.gov (United States)

Crawford, John R.; Garthwaite, Paul H.; Sutherland, David; Borland, Nicola

2011-01-01

Supplementary methods for the analysis of the Delis-Kaplan Executive Function System (Delis, Kaplan, & Kramer, 2001) are made available, including (a) quantifying the number of abnormally low achievement scores exhibited by an individual and accompanying this with an estimate of the percentage of the normative population expected to exhibit at…

Methods for integrating a functional component into a microfluidic device

Science.gov (United States)

Simmons, Blake; Domeier, Linda; Woo, Noble; Shepodd, Timothy; Renzi, Ronald F.

2014-08-19

Injection molding is used to form microfluidic devices with integrated functional components. One or more functional components are placed in a mold cavity, which is then closed. Molten thermoplastic resin is injected into the mold and then cooled, thereby forming a solid substrate including the functional component(s). The solid substrate including the functional component(s) is then bonded to a second substrate, which may include microchannels or other features.

Analytic function expansion nodal method for nuclear reactor core design

International Nuclear Information System (INIS)

Noh, Hae Man

1995-02-01

deriving the nodal coupling equations, it does not suffer from the limitations caused by the transverse integration, such as the need of transverse leakage approximation and the singularity arising in non-rectangular node geometries. And because of the use of analytic basis functions, the method accurately models large localized flux gradients in the vicinity of nodal corner points as well as nodal interfaces. To demonstrate its accuracy and applicability to realistic problems, the AFEN method was tested to several benchmark problems in both the rectangular and the hexagonal geometry, including MOX fuel problems, and the initial core of Ulchin Unit 1. The results show that the AFEN method significantly improves the accuracy in the nodal flux distribution and the core multiplication factor compared to the nodal methods which use the transverse integration. The method also facilitates pinwise flux reconstruction since the homogeneous flux distributions obtained from the nodal calculation are very accurate and can be used directly in the reconstruction. Encouraged by the success of the AFEN method, we also developed two other nodal methods in this study, which can be classified as variations of the AFEN method. The first one is the Polynomial Expansion Nodal (PEN) method. This method retains all the features of the AFEN method except expanding the intranodal flux distribution into a nonseparable high-order polynomial instead of the analytic function. The results of benchmark problems indicate mixed performance of the method. For the conventional light water reactor cores loaded with the conventional UO 2 fuel assembly, the performance of the method is similar to that of the AFEN method, but for the reactor cores loaded with the MOX fuel assemblies, the PEN method is poorer than the AFEN method. The poor performance of the PEN method for the MOX fuel loaded cores is due to the fact that the polynomial is less accurate for the representation of the intranodal flux distribution

Basic methods of linear functional analysis

CERN Document Server

Pryce, John D

2011-01-01

Introduction to the themes of mathematical analysis, geared toward advanced undergraduate and graduate students. Topics include operators, function spaces, Hilbert spaces, and elementary Fourier analysis. Numerous exercises and worked examples.1973 edition.

Methods uncovering usability issues in medication-related alerting functions: results from a systematic review.

Science.gov (United States)

Marcilly, Romaric; Vasseur, Francis; Ammenwerth, Elske; Beuscart-Zephir, Marie-Catherine

2014-01-01

This paper aims at listing the methods used to evaluate the usability of medication-related alerting functions and at knowing what type of usability issues those methods allow to detect. A sub-analysis of data from this systematic review has been performed. Methods applied in the included papers were collected. Then, included papers were sorted in four types of evaluation: "expert evaluation", "user- testing/simulation", "on site observation" and "impact studies". The types of usability issues (usability flaws, usage problems and negative outcomes) uncovered by those evaluations were analyzed. Results show that a large set of methods are used. The largest proportion of papers uses "on site observation" evaluation. This is the only evaluation type for which every kind of usability flaws, usage problems and outcomes are detected. It is somehow surprising that, in a usability systematic review, most of the papers included use a method that is not often presented as a usability method. Results are discussed about the opportunity to provide usability information collected after the implementation of the technology during their design process, i.e. before their implementation.

Computing wave functions in multichannel collisions with non-local potentials using the R-matrix method

Science.gov (United States)

Bonitati, Joey; Slimmer, Ben; Li, Weichuan; Potel, Gregory; Nunes, Filomena

2017-09-01

The calculable form of the R-matrix method has been previously shown to be a useful tool in approximately solving the Schrodinger equation in nuclear scattering problems. We use this technique combined with the Gauss quadrature for the Lagrange-mesh method to efficiently solve for the wave functions of projectile nuclei in low energy collisions (1-100 MeV) involving an arbitrary number of channels. We include the local Woods-Saxon potential, the non-local potential of Perey and Buck, a Coulomb potential, and a coupling potential to computationally solve for the wave function of two nuclei at short distances. Object oriented programming is used to increase modularity, and parallel programming techniques are introduced to reduce computation time. We conclude that the R-matrix method is an effective method to predict the wave functions of nuclei in scattering problems involving both multiple channels and non-local potentials. Michigan State University iCER ACRES REU.

Theoretical method for determining particle distribution functions of classical systems

International Nuclear Information System (INIS)

Johnson, E.

1980-01-01

An equation which involves the triplet distribution function and the three-particle direct correlation function is obtained. This equation was derived using an analogue of the Ornstein--Zernike equation. The new equation is used to develop a variational method for obtaining the triplet distribution function of uniform one-component atomic fluids from the pair distribution function. The variational method may be used with the first and second equations in the YBG hierarchy to obtain pair and triplet distribution functions. It should be easy to generalize the results to the n-particle distribution function

High-temperature electronic structure with the Korringa-Kohn-Rostoker Green's function method

Science.gov (United States)

Starrett, C. E.

2018-05-01

Modeling high-temperature (tens or hundreds of eV), dense plasmas is challenging due to the multitude of non-negligible physical effects including significant partial ionization and multisite effects. These effects cause the breakdown or intractability of common methods and approximations used at low temperatures, such as pseudopotentials or plane-wave basis sets. Here we explore the Korringa-Kohn-Rostoker Green's function method at these high-temperature conditions. The method is all electron, does not rely on pseudopotentials, and uses a spherical harmonic basis set, and so avoids the aforementioned limitations. It is found to be accurate for solid density aluminum and iron plasmas when compared to a plane-wave method at low temperature, while being able to access high temperatures.

Numerical methods for hyperbolic differential functional problems

Directory of Open Access Journals (Sweden)

Roman Ciarski

2008-01-01

Full Text Available The paper deals with the initial boundary value problem for quasilinear first order partial differential functional systems. A general class of difference methods for the problem is constructed. Theorems on the error estimate of approximate solutions for difference functional systems are presented. The convergence results are proved by means of consistency and stability arguments. A numerical example is given.

Global Convergence of Arbitrary-Block Gradient Methods for Generalized Polyak-{\\L} ojasiewicz Functions

KAUST Repository

Csiba, Dominik

2017-09-09

In this paper we introduce two novel generalizations of the theory for gradient descent type methods in the proximal setting. First, we introduce the proportion function, which we further use to analyze all known (and many new) block-selection rules for block coordinate descent methods under a single framework. This framework includes randomized methods with uniform, non-uniform or even adaptive sampling strategies, as well as deterministic methods with batch, greedy or cyclic selection rules. Second, the theory of strongly-convex optimization was recently generalized to a specific class of non-convex functions satisfying the so-called Polyak-{\\\\L}ojasiewicz condition. To mirror this generalization in the weakly convex case, we introduce the Weak Polyak-{\\\\L}ojasiewicz condition, using which we give global convergence guarantees for a class of non-convex functions previously not considered in theory. Additionally, we establish (necessarily somewhat weaker) convergence guarantees for an even larger class of non-convex functions satisfying a certain smoothness assumption only. By combining the two abovementioned generalizations we recover the state-of-the-art convergence guarantees for a large class of previously known methods and setups as special cases of our general framework. Moreover, our frameworks allows for the derivation of new guarantees for many new combinations of methods and setups, as well as a large class of novel non-convex objectives. The flexibility of our approach offers a lot of potential for future research, as a new block selection procedure will have a convergence guarantee for all objectives considered in our framework, while a new objective analyzed under our approach will have a whole fleet of block selection rules with convergence guarantees readily available.

Global Convergence of Arbitrary-Block Gradient Methods for Generalized Polyak-{\\L} ojasiewicz Functions

KAUST Repository

Csiba, Dominik; Richtarik, Peter

2017-01-01

In this paper we introduce two novel generalizations of the theory for gradient descent type methods in the proximal setting. First, we introduce the proportion function, which we further use to analyze all known (and many new) block-selection rules for block coordinate descent methods under a single framework. This framework includes randomized methods with uniform, non-uniform or even adaptive sampling strategies, as well as deterministic methods with batch, greedy or cyclic selection rules. Second, the theory of strongly-convex optimization was recently generalized to a specific class of non-convex functions satisfying the so-called Polyak-{\\L}ojasiewicz condition. To mirror this generalization in the weakly convex case, we introduce the Weak Polyak-{\\L}ojasiewicz condition, using which we give global convergence guarantees for a class of non-convex functions previously not considered in theory. Additionally, we establish (necessarily somewhat weaker) convergence guarantees for an even larger class of non-convex functions satisfying a certain smoothness assumption only. By combining the two abovementioned generalizations we recover the state-of-the-art convergence guarantees for a large class of previously known methods and setups as special cases of our general framework. Moreover, our frameworks allows for the derivation of new guarantees for many new combinations of methods and setups, as well as a large class of novel non-convex objectives. The flexibility of our approach offers a lot of potential for future research, as a new block selection procedure will have a convergence guarantee for all objectives considered in our framework, while a new objective analyzed under our approach will have a whole fleet of block selection rules with convergence guarantees readily available.

Exact solutions for nonlinear evolution equations using Exp-function method

International Nuclear Information System (INIS)

Bekir, Ahmet; Boz, Ahmet

2008-01-01

In this Letter, the Exp-function method is used to construct solitary and soliton solutions of nonlinear evolution equations. The Klein-Gordon, Burger-Fisher and Sharma-Tasso-Olver equations are chosen to illustrate the effectiveness of the method. The method is straightforward and concise, and its applications are promising. The Exp-function method presents a wider applicability for handling nonlinear wave equations

Ocena funkcija saobraćajne podrške primenom metode procesnih funkcija / Evaluation of the traffic support functions using the processing function method

Directory of Open Access Journals (Sweden)

Goran Tadić

2005-05-01

Full Text Available U naučnoj organizaciji rada razvijeno je više metoda za ocenu postojećeg organizacionog nivoa. Organizovanost se može analizirati na različitim nivoima, kao što su: poslovne funkcije, organizacijske jedinice, područja rada u okviru pojedinih funkcija ili organizacijskih jedinica, kao i elemenata poslovanja. Analitički postupak, koji daje metoda procesnih funkcija, omogućuje kvantitativno ocenjivanje organizacionog nivoa funkcija i, polazeći od toga, preciziranje i programiranje mera za dalje organizacijsko delovanje. U radu je prikazana primena metode procesnih funkcija u ocenjivanju funkcija saobraćajne podrške korpusa kopnene vojske. / To appraise the existing organizational solutions -within the scientific organization of work, there are several methods. Organization could be analyzed at different levels such as: functionality, organizational units, -working areas included in some functions or organizational units and also into -work elements. Analytical order, given by the method of processing function, permits us to evaluate the level of organizational functions and starting from this point, precising and programming orders for further organizational -work could be done. In this paper, the methods of processing functions in evaluation of the functions of traffic support for army corps could be read.

A New Filled Function Method with One Parameter for Global Optimization

Directory of Open Access Journals (Sweden)

Fei Wei

2013-01-01

Full Text Available The filled function method is an effective approach to find the global minimizer of multidimensional multimodal functions. The conventional filled functions are numerically unstable due to exponential or logarithmic term and sensitive to parameters. In this paper, a new filled function with only one parameter is proposed, which is continuously differentiable and proved to satisfy all conditions of the filled function definition. Moreover, this filled function is not sensitive to parameter, and the overflow can not happen for this function. Based on these, a new filled function method is proposed, and it is numerically stable to the initial point and the parameter variable. The computer simulations indicate that the proposed filled function method is efficient and effective.

Numerical functional integration method for studying the properties of the physical vacuum

International Nuclear Information System (INIS)

Lobanov, Yu.Yu.

1998-01-01

The new approach to investigate the physical vacuum in quantum theories including its nonperturbative topological structure is discussed. This approach is based on the representation of the matrix element of the evolution operator in Euclidean metrics in a form of the functional integral with a certain measure in the corresponding space and on the use of approximation formulas which we constructed for this kind of integral. No preliminary discretization of space and time is required, as well as no simplifying assumptions like semiclassical approximation, collective excitations, introduction of ''short-time'' propagators, etc. are necessary in this approach. The method allows to use the more preferable deterministic algorithms instead of the traditional stochastic technique. It has been proven that our approach has important advantages over the other known methods, including the higher efficiency of computations. Examples of application of the method to the numerical study of some potential nuclear models and to the computation of the topological susceptibility and the θ-vacua energy are presented. (author)

Self-consistent DFT +U method for real-space time-dependent density functional theory calculations

Science.gov (United States)

Tancogne-Dejean, Nicolas; Oliveira, Micael J. T.; Rubio, Angel

2017-12-01

We implemented various DFT+U schemes, including the Agapito, Curtarolo, and Buongiorno Nardelli functional (ACBN0) self-consistent density-functional version of the DFT +U method [Phys. Rev. X 5, 011006 (2015), 10.1103/PhysRevX.5.011006] within the massively parallel real-space time-dependent density functional theory (TDDFT) code octopus. We further extended the method to the case of the calculation of response functions with real-time TDDFT+U and to the description of noncollinear spin systems. The implementation is tested by investigating the ground-state and optical properties of various transition-metal oxides, bulk topological insulators, and molecules. Our results are found to be in good agreement with previously published results for both the electronic band structure and structural properties. The self-consistent calculated values of U and J are also in good agreement with the values commonly used in the literature. We found that the time-dependent extension of the self-consistent DFT+U method yields improved optical properties when compared to the empirical TDDFT+U scheme. This work thus opens a different theoretical framework to address the nonequilibrium properties of correlated systems.

The interpolation method of stochastic functions and the stochastic variational principle

International Nuclear Information System (INIS)

Liu Xianbin; Chen Qiu

1993-01-01

Uncertainties have been attaching more importance to increasingly in modern engineering structural design. Viewed on an appropriate scale, the inherent physical attributes (material properties) of many structural systems always exhibit some patterns of random variation in space and time, generally the random variation shows a small parameter fluctuation. For a linear mechanical system, the random variation is modeled as a random one of a linear partial differential operator and, in stochastic finite element method, a random variation of a stiffness matrix. Besides the stochasticity of the structural physical properties, the influences of random loads which always represent themselves as the random boundary conditions bring about much more complexities in structural analysis. Now the stochastic finite element method or the probabilistic finite element method is used to study the structural systems with random physical parameters, whether or not the loads are random. Differing from the general finite element theory, the main difficulty which the stochastic finite element method faces is the inverse operation of stochastic operators and stochastic matrices, since the inverse operators and the inverse matrices are statistically correlated to the random parameters and random loads. So far, many efforts have been made to obtain the reasonably approximate expressions of the inverse operators and inverse matrices, such as Perturbation Method, Neumann Expansion Method, Galerkin Method (in appropriate Hilbert Spaces defined for random functions), Orthogonal Expansion Method. Among these methods, Perturbation Method appear to be the most available. The advantage of these methods is that the fairly accurate response statistics can be obtained under the condition of the finite information of the input. However, the second-order statistics obtained by use of Perturbation Method and Neumann Expansion Method are not always the appropriate ones, because the relevant second

Recent Advances in the Korringa-Kohn-Rostoker Green Function Method

Directory of Open Access Journals (Sweden)

Zeller Rudolf

2014-01-01

Full Text Available The Korringa-Kohn-Rostoker (KKR Green function (GF method is a technique for all-electron full-potential density-functional calculations. Similar to the historical Wigner-Seitz cellular method, the KKR-GF method uses a partitioning of space into atomic Wigner-Seitz cells. However, the numerically demanding wave-function matching at the cell boundaries is avoided by use of an integral equation formalism based on the concept of reference Green functions. The advantage of this formalism will be illustrated by the recent progress made for very large systems with thousands of inequivalent atoms and for very accurate calculations of atomic forces and total energies.

Cross-organism learning method to discover new gene functionalities.

Science.gov (United States)

Domeniconi, Giacomo; Masseroli, Marco; Moro, Gianluca; Pinoli, Pietro

2016-04-01

Knowledge of gene and protein functions is paramount for the understanding of physiological and pathological biological processes, as well as in the development of new drugs and therapies. Analyses for biomedical knowledge discovery greatly benefit from the availability of gene and protein functional feature descriptions expressed through controlled terminologies and ontologies, i.e., of gene and protein biomedical controlled annotations. In the last years, several databases of such annotations have become available; yet, these valuable annotations are incomplete, include errors and only some of them represent highly reliable human curated information. Computational techniques able to reliably predict new gene or protein annotations with an associated likelihood value are thus paramount. Here, we propose a novel cross-organisms learning approach to reliably predict new functionalities for the genes of an organism based on the known controlled annotations of the genes of another, evolutionarily related and better studied, organism. We leverage a new representation of the annotation discovery problem and a random perturbation of the available controlled annotations to allow the application of supervised algorithms to predict with good accuracy unknown gene annotations. Taking advantage of the numerous gene annotations available for a well-studied organism, our cross-organisms learning method creates and trains better prediction models, which can then be applied to predict new gene annotations of a target organism. We tested and compared our method with the equivalent single organism approach on different gene annotation datasets of five evolutionarily related organisms (Homo sapiens, Mus musculus, Bos taurus, Gallus gallus and Dictyostelium discoideum). Results show both the usefulness of the perturbation method of available annotations for better prediction model training and a great improvement of the cross-organism models with respect to the single-organism ones

A second-order unconstrained optimization method for canonical-ensemble density-functional methods

Science.gov (United States)

Nygaard, Cecilie R.; Olsen, Jeppe

2013-03-01

A second order converging method of ensemble optimization (SOEO) in the framework of Kohn-Sham Density-Functional Theory is presented, where the energy is minimized with respect to an ensemble density matrix. It is general in the sense that the number of fractionally occupied orbitals is not predefined, but rather it is optimized by the algorithm. SOEO is a second order Newton-Raphson method of optimization, where both the form of the orbitals and the occupation numbers are optimized simultaneously. To keep the occupation numbers between zero and two, a set of occupation angles is defined, from which the occupation numbers are expressed as trigonometric functions. The total number of electrons is controlled by a built-in second order restriction of the Newton-Raphson equations, which can be deactivated in the case of a grand-canonical ensemble (where the total number of electrons is allowed to change). To test the optimization method, dissociation curves for diatomic carbon are produced using different functionals for the exchange-correlation energy. These curves show that SOEO favors symmetry broken pure-state solutions when using functionals with exact exchange such as Hartree-Fock and Becke three-parameter Lee-Yang-Parr. This is explained by an unphysical contribution to the exact exchange energy from interactions between fractional occupations. For functionals without exact exchange, such as local density approximation or Becke Lee-Yang-Parr, ensemble solutions are favored at interatomic distances larger than the equilibrium distance. Calculations on the chromium dimer are also discussed. They show that SOEO is able to converge to ensemble solutions for systems that are more complicated than diatomic carbon.

Evaluation of snubber functional test methods: Tier 1

International Nuclear Information System (INIS)

Brown, D.P.

1993-07-01

The objective of the research is to establish technical bases in support of efforts on the part of the Snubber Utility Group (SNUG) and the Subsection ISTD Working Group of the ASME O ampersand M Code in developing guidelines and methodologies for snubber functional testing to ensure that snubbers are tested in a manner that ensures reliable and meaningful test results. The methodology used in this research includes both a review of available industry information as well as the testing of different snubber models using various test machines. Information is provided pertaining to current industry practices in regard to snubber testing including recommended test procedures, technical description of various test machines, and the number and types of snubbers used in the nuclear power industry. A review of previous test methodology research conducted by the Snubber Utility Group is also included. The effects of variations in controllable test parameters on snubber test results are discussed. Also included are the results of confirmatory tests in which various snubber models were tested using various test machines. Recommendations are provided for standard test methods to be included in Subsection ISTD of the ASME O ampersand M Code [4]. General information and recommendations are provided that may be used by utility personnel in specifying snubber test equipment that is most suited for plant-specific needs as well as information that may be effectively used in the review and interpretation of test results

A logic circuit for solving linear function by digital method

International Nuclear Information System (INIS)

Ma Yonghe

1986-01-01

A mathematical method for determining the linear relation of physical quantity with rediation intensity is described. A logic circuit has been designed for solving linear function by digital method. Some applications and the circuit function are discussed

Etiopathophysiological assessment of cases with chronic daily headache: A functional magnetic resonance imaging included investigation

Science.gov (United States)

Hashemi, Akram; Nami, Mohammad Torabi; Oghabian, Mohammad Ali; Ganjgahi, Habib; Vahabi, Zahra

2012-01-01

Background Chronic daily headache (CDH) has gained little attention in functional neuro-imaging. When no structural abnormality is found in CDH, defining functional correlates between activated brain regions during headache bouts may provide unique insights towards understanding the pathophysiology of this type of headache. Methods We recruited four CDH cases for comprehensive assessments, including history taking, physical examinations and neuropsychological evaluations (The Addenbrooke's Cognitive Evaluation, Beck's Anxiety and Depression Inventories, Pittsburg Sleep Quality Index and Epworth Sleepiness Scale). Visual analogue scale (VAS) was used to self-rate the intensity of headache. Patients then underwent electroencephalography (EEG), transcranial Doppler (TCD) and functional magnetic resonance imaging (fMRI) evaluations during maximal (VAS = 8-10/10) and off-headache (VAS = 0-3/10) conditions. Data were used to compare in both conditions. We also used BOLD (blood oxygen level dependent) -group level activation map fMRI to possibly locate headache-related activated brain regions. Results General and neurological examinations as well as conventional MRIs were unremarkable. Neuropsychological assessments showed moderate anxiety and depression in one patient and minimal in others. Unlike three patients, maximal and off-headache TCD evaluation in one revealed increased middle cerebral artery blood flow velocity, at the maximal pain area. Although with no seizure history, the same patient's EEG showed paroxysmal epileptic discharges during maximal headache intensity, respectively. Group level activation map fMRI showed activated classical pain matrix regions upon headache bouts (periaqueductal grey, substantia nigra and raphe nucleus), and markedly bilateral occipital lobes activation. Conclusion The EEG changes were of note. Furthermore, the increased BOLD signals in areas outside the classical pain matrix (i.e. occipital lobes) during maximal headaches may

Approximation methods for the partition functions of anharmonic systems

International Nuclear Information System (INIS)

Lew, P.; Ishida, T.

1979-07-01

The analytical approximations for the classical, quantum mechanical and reduced partition functions of the diatomic molecule oscillating internally under the influence of the Morse potential have been derived and their convergences have been tested numerically. This successful analytical method is used in the treatment of anharmonic systems. Using Schwinger perturbation method in the framework of second quantization formulism, the reduced partition function of polyatomic systems can be put into an expression which consists separately of contributions from the harmonic terms, Morse potential correction terms and interaction terms due to the off-diagonal potential coefficients. The calculated results of the reduced partition function from the approximation method on the 2-D and 3-D model systems agree well with the numerical exact calculations

Accident Analysis and Barrier Function (AEB) Method. Manual for Incident Analysis

International Nuclear Information System (INIS)

Svenson, Ola

2000-02-01

The Accident Analysis and Barrier Function (AEB) Method models an accident or incident as a series of interactions between human and technical systems. In the sequence of human and technical errors leading to an accident there is, in principle, a possibility to arrest the development between each two successive errors. This can be done by a barrier function which, for example, can stop an operator from making an error. A barrier function can be performed by one or several barrier function systems. To illustrate, a mechanical system, a computer system or another operator can all perform a given barrier function to stop an operator from making an error. The barrier function analysis consists of analysis of suggested improvements, the effectiveness of the improvements, the costs of implementation, probability of implementation, the cost of maintaining the barrier function, the probability that maintenance will be kept up to standards and the generalizability of the suggested improvement. The AEB method is similar to the US method called HPES, but differs from that method in different ways. To exemplify, the AEB method has more emphasis on technical errors than HPES. In contrast to HPES that describes a series of events, the AEB method models only errors. This gives a more focused analysis making it well suited for checking other HPES-type accident analyses. However, the AEB method is a generic and stand-alone method that has been applied in other fields than nuclear power, such as, in traffic accident analyses

Accident Analysis and Barrier Function (AEB) Method. Manual for Incident Analysis

Energy Technology Data Exchange (ETDEWEB)

Svenson, Ola [Stockholm Univ. (Sweden). Dept. of Psychology

2000-02-01

The Accident Analysis and Barrier Function (AEB) Method models an accident or incident as a series of interactions between human and technical systems. In the sequence of human and technical errors leading to an accident there is, in principle, a possibility to arrest the development between each two successive errors. This can be done by a barrier function which, for example, can stop an operator from making an error. A barrier function can be performed by one or several barrier function systems. To illustrate, a mechanical system, a computer system or another operator can all perform a given barrier function to stop an operator from making an error. The barrier function analysis consists of analysis of suggested improvements, the effectiveness of the improvements, the costs of implementation, probability of implementation, the cost of maintaining the barrier function, the probability that maintenance will be kept up to standards and the generalizability of the suggested improvement. The AEB method is similar to the US method called HPES, but differs from that method in different ways. To exemplify, the AEB method has more emphasis on technical errors than HPES. In contrast to HPES that describes a series of events, the AEB method models only errors. This gives a more focused analysis making it well suited for checking other HPES-type accident analyses. However, the AEB method is a generic and stand-alone method that has been applied in other fields than nuclear power, such as, in traffic accident analyses.

Fibonacci collocation method with a residual error Function to solve linear Volterra integro differential equations

Directory of Open Access Journals (Sweden)

Salih Yalcinbas

2016-01-01

Full Text Available In this paper, a new collocation method based on the Fibonacci polynomials is introduced to solve the high-order linear Volterra integro-differential equations under the conditions. Numerical examples are included to demonstrate the applicability and validity of the proposed method and comparisons are made with the existing results. In addition, an error estimation based on the residual functions is presented for this method. The approximate solutions are improved by using this error estimation.

Improved non-dimensional dynamic influence function method for vibration analysis of arbitrarily shaped plates with clamped edges

Directory of Open Access Journals (Sweden)

Sang-Wook Kang

2016-03-01

Full Text Available A new formulation for the non-dimensional dynamic influence function method, which was developed by the authors, is proposed to efficiently extract eigenvalues and mode shapes of clamped plates with arbitrary shapes. Compared with the finite element and boundary element methods, the non-dimensional dynamic influence function method yields highly accurate solutions in eigenvalue analysis problems of plates and membranes including acoustic cavities. However, the non-dimensional dynamic influence function method requires the uneconomic procedure of calculating the singularity of a system matrix in the frequency range of interest for extracting eigenvalues because it produces a non-algebraic eigenvalue problem. This article describes a new approach that reduces the problem of free vibrations of clamped plates to an algebraic eigenvalue problem, the solution of which is straightforward. The validity and efficiency of the proposed method are illustrated through several numerical examples.

Representing uncertainty in objective functions: extension to include the influence of serial correlation

Science.gov (United States)

Croke, B. F.

2008-12-01

The role of performance indicators is to give an accurate indication of the fit between a model and the system being modelled. As all measurements have an associated uncertainty (determining the significance that should be given to the measurement), performance indicators should take into account uncertainties in the observed quantities being modelled as well as in the model predictions (due to uncertainties in inputs, model parameters and model structure). In the presence of significant uncertainty in observed and modelled output of a system, failure to adequately account for variations in the uncertainties means that the objective function only gives a measure of how well the model fits the observations, not how well the model fits the system being modelled. Since in most cases, the interest lies in fitting the system response, it is vital that the objective function(s) be designed to account for these uncertainties. Most objective functions (e.g. those based on the sum of squared residuals) assume homoscedastic uncertainties. If model contribution to the variations in residuals can be ignored, then transformations (e.g. Box-Cox) can be used to remove (or at least significantly reduce) heteroscedasticity. An alternative which is more generally applicable is to explicitly represent the uncertainties in the observed and modelled values in the objective function. Previous work on this topic addressed the modifications to standard objective functions (Nash-Sutcliffe efficiency, RMSE, chi- squared, coefficient of determination) using the optimal weighted averaging approach. This paper extends this previous work; addressing the issue of serial correlation. A form for an objective function that includes serial correlation will be presented, and the impact on model fit discussed.

On the trial functions in nested element method

International Nuclear Information System (INIS)

Altiparmakov, D.V.

1985-01-01

The R-function method is applied to the multidimensional steady-state neutron diffusion equation. Using a variational principle the nested element approximation is formulated. Trial functions taking into account the geometrical shape of material regions are constructed. The influence of both the surrounding regions and the corner singularities at the external boundary is incorporated into the approximate solution. Benchmark calculations show that such an approximation can yield satisfactory results. Moreover, in the case of complex geometry, the presented approach would result in a significant reduction of the number of unknowns compared to other methods

Identification of fractional order systems using modulating functions method

KAUST Repository

Liu, Dayan

2013-06-01

The modulating functions method has been used for the identification of linear and nonlinear systems. In this paper, we generalize this method to the on-line identification of fractional order systems based on the Riemann-Liouville fractional derivatives. First, a new fractional integration by parts formula involving the fractional derivative of a modulating function is given. Then, we apply this formula to a fractional order system, for which the fractional derivatives of the input and the output can be transferred into the ones of the modulating functions. By choosing a set of modulating functions, a linear system of algebraic equations is obtained. Hence, the unknown parameters of a fractional order system can be estimated by solving a linear system. Using this method, we do not need any initial values which are usually unknown and not equal to zero. Also we do not need to estimate the fractional derivatives of noisy output. Moreover, it is shown that the proposed estimators are robust against high frequency sinusoidal noises and the ones due to a class of stochastic processes. Finally, the efficiency and the stability of the proposed method is confirmed by some numerical simulations.

Function combined method for design innovation of children's bike

Science.gov (United States)

Wu, Xiaoli; Qiu, Tingting; Chen, Huijuan

2013-03-01

As children mature, bike products for children in the market develop at the same time, and the conditions are frequently updated. Certain problems occur when using a bike, such as cycle overlapping, repeating function, and short life cycle, which go against the principles of energy conservation and the environmental protection intensive design concept. In this paper, a rational multi-function method of design through functional superposition, transformation, and technical implementation is proposed. An organic combination of frog-style scooter and children's tricycle is developed using the multi-function method. From the ergonomic perspective, the paper elaborates on the body size of children aged 5 to 12 and effectively extracts data for a multi-function children's bike, which can be used for gliding and riding. By inverting the body, parts can be interchanged between the handles and the pedals of the bike. Finally, the paper provides a detailed analysis of the components and structural design, body material, and processing technology of the bike. The study of Industrial Product Innovation Design provides an effective design method to solve the bicycle problems, extends the function problems, improves the product market situation, and enhances the energy saving feature while implementing intensive product development effectively at the same time.

The extended hyperbolic function method and exact solutions of the long-short wave resonance equations

International Nuclear Information System (INIS)

Shang Yadong

2008-01-01

The extended hyperbolic functions method for nonlinear wave equations is presented. Based on this method, we obtain a multiple exact explicit solutions for the nonlinear evolution equations which describe the resonance interaction between the long wave and the short wave. The solutions obtained in this paper include (a) the solitary wave solutions of bell-type for S and L, (b) the solitary wave solutions of kink-type for S and bell-type for L, (c) the solitary wave solutions of a compound of the bell-type and the kink-type for S and L, (d) the singular travelling wave solutions, (e) periodic travelling wave solutions of triangle function types, and solitary wave solutions of rational function types. The variety of structure to the exact solutions of the long-short wave equation is illustrated. The methods presented here can also be used to obtain exact solutions of nonlinear wave equations in n dimensions

An improved method for estimating the frequency correlation function

KAUST Repository

Chelli, Ali; Pä tzold, Matthias

2012-01-01

For time-invariant frequency-selective channels, the transfer function is a superposition of waves having different propagation delays and path gains. In order to estimate the frequency correlation function (FCF) of such channels, the frequency averaging technique can be utilized. The obtained FCF can be expressed as a sum of auto-terms (ATs) and cross-terms (CTs). The ATs are caused by the autocorrelation of individual path components. The CTs are due to the cross-correlation of different path components. These CTs have no physical meaning and leads to an estimation error. We propose a new estimation method aiming to improve the estimation accuracy of the FCF of a band-limited transfer function. The basic idea behind the proposed method is to introduce a kernel function aiming to reduce the CT effect, while preserving the ATs. In this way, we can improve the estimation of the FCF. The performance of the proposed method and the frequency averaging technique is analyzed using a synthetically generated transfer function. We show that the proposed method is more accurate than the frequency averaging technique. The accurate estimation of the FCF is crucial for the system design. In fact, we can determine the coherence bandwidth from the FCF. The exact knowledge of the coherence bandwidth is beneficial in both the design as well as optimization of frequency interleaving and pilot arrangement schemes. © 2012 IEEE.

An improved method for estimating the frequency correlation function

KAUST Repository

Chelli, Ali

2012-04-01

For time-invariant frequency-selective channels, the transfer function is a superposition of waves having different propagation delays and path gains. In order to estimate the frequency correlation function (FCF) of such channels, the frequency averaging technique can be utilized. The obtained FCF can be expressed as a sum of auto-terms (ATs) and cross-terms (CTs). The ATs are caused by the autocorrelation of individual path components. The CTs are due to the cross-correlation of different path components. These CTs have no physical meaning and leads to an estimation error. We propose a new estimation method aiming to improve the estimation accuracy of the FCF of a band-limited transfer function. The basic idea behind the proposed method is to introduce a kernel function aiming to reduce the CT effect, while preserving the ATs. In this way, we can improve the estimation of the FCF. The performance of the proposed method and the frequency averaging technique is analyzed using a synthetically generated transfer function. We show that the proposed method is more accurate than the frequency averaging technique. The accurate estimation of the FCF is crucial for the system design. In fact, we can determine the coherence bandwidth from the FCF. The exact knowledge of the coherence bandwidth is beneficial in both the design as well as optimization of frequency interleaving and pilot arrangement schemes. © 2012 IEEE.

Meshfree Local Radial Basis Function Collocation Method with Image Nodes

Energy Technology Data Exchange (ETDEWEB)

Baek, Seung Ki; Kim, Minjae [Pukyong National University, Busan (Korea, Republic of)

2017-07-15

We numerically solve two-dimensional heat diffusion problems by using a simple variant of the meshfree local radial-basis function (RBF) collocation method. The main idea is to include an additional set of sample nodes outside the problem domain, similarly to the method of images in electrostatics, to perform collocation on the domain boundaries. We can thereby take into account the temperature profile as well as its gradients specified by boundary conditions at the same time, which holds true even for a node where two or more boundaries meet with different boundary conditions. We argue that the image method is computationally efficient when combined with the local RBF collocation method, whereas the addition of image nodes becomes very costly in case of the global collocation. We apply our modified method to a benchmark test of a boundary value problem, and find that this simple modification reduces the maximum error from the analytic solution significantly. The reduction is small for an initial value problem with simpler boundary conditions. We observe increased numerical instability, which has to be compensated for by a sufficient number of sample nodes and/or more careful parameter choices for time integration.

Methods for selective functionalization and separation of carbon nanotubes

Science.gov (United States)

Strano, Michael S. (Inventor); Usrey, Monica (Inventor); Barone, Paul (Inventor); Dyke, Christopher A. (Inventor); Tour, James M. (Inventor); Kittrell, W. Carter (Inventor); Hauge, Robert H (Inventor); Smalley, Richard E. (Inventor); Marek, legal representative, Irene Marie (Inventor)

2011-01-01

The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.

[Cognitive functions, their development and modern diagnostic methods].

Science.gov (United States)

Klasik, Adam; Janas-Kozik, Małgorzata; Krupka-Matuszczyk, Irena; Augustyniak, Ewa

2006-01-01

provided a theory. The psychometric approach concentrates on studying the differences in intelligence. The aim of this approach is to test intelligence by means of standardized tests (e.g. WISC-R, WAIS-R) used to show the individual differences among humans. Human cognitive functions determine individuals' adaptation capabilities and disturbances in this area indicate a number of psychopathological changes and are a symptom enabling to differentiate or diagnose one with a disorder. That is why the psychological assessment of cognitive functions is an important part of patients' diagnosis. Contemporary neuropsychological studies are to a great extent based computer tests. The use of computer methods has a number of measurement-related advantages. It allows for standardized testing environment, increasing therefore its reliability and standardizes the patient assessment process. Special attention should be paid to the neuropsychological tests included in the Vienna Test System (Cognitron, SIGNAL, RT, VIGIL, DAUF), which are used to assess the operational memory span, learning processes, reaction time, attention selective function, attention continuity as well as attention interference resistance. It also seems justified to present the CPT id test (Continuous Performance Test) as well as Free Recall. CPT is a diagnostic tool used to assess the attention selective function, attention continuity of attention, attention interference resistance as well as attention alertness. The Free Recall test is used in the memory processes diagnostics to assess patients' operational memory as well as the information organization degree in operational memory. The above mentioned neuropsychological tests are tools used in clinical assessment of cognitive function disorders.

Systems and Methods for Fabricating Structures Including Metallic Glass-Based Materials Using Low Pressure Casting

Science.gov (United States)

Hofmann, Douglas C. (Inventor); Kennett, Andrew (Inventor)

2018-01-01

Systems and methods to fabricate objects including metallic glass-based materials using low-pressure casting techniques are described. In one embodiment, a method of fabricating an object that includes a metallic glass-based material includes: introducing molten alloy into a mold cavity defined by a mold using a low enough pressure such that the molten alloy does not conform to features of the mold cavity that are smaller than 100 microns; and cooling the molten alloy such that it solidifies, the solid including a metallic glass-based material.

Modeling photonic crystal waveguides with noncircular geometry using green function method

International Nuclear Information System (INIS)

Uvarovaa, I.; Tsyganok, B.; Bashkatov, Y.; Khomenko, V.

2012-01-01

Currently in the field of photonics is an acute problem fast and accurate simulation photonic crystal waveguides with complex geometry. This paper describes an improved method of Green's functions for non-circular geometries. Based on comparison of selected efficient numerical method for finding the eigenvalues for the Green's function method for non-circular holes chosen effective method for our purposes. Simulation is realized in Maple environment. The simulation results confirmed experimentally. Key words: photonic crystal, waveguide, modeling, Green function, complex geometry

Methods library of embedded R functions at Statistics Norway

Directory of Open Access Journals (Sweden)

Øyvind Langsrud

2017-11-01

Full Text Available Statistics Norway is modernising the production processes. An important element in this work is a library of functions for statistical computations. In principle, the functions in such a methods library can be programmed in several languages. A modernised production environment demand that these functions can be reused for different statistics products, and that they are embedded within a common IT system. The embedding should be done in such a way that the users of the methods do not need to know the underlying programming language. As a proof of concept, Statistics Norway soon has established a methods library offering a limited number of methods for macro-editing, imputation and confidentiality. This is done within an area of municipal statistics with R as the only programming language. This paper presents the details and experiences from this work. The problem of fitting real word applications to simple and strict standards is discussed and exemplified by the development of solutions to regression imputation and table suppression.

Solar cells, structures including organometallic halide perovskite monocrystalline films, and methods of preparation thereof

KAUST Repository

Bakr, Osman; Peng, Wei; Wang, Lingfei

2017-01-01

Embodiments of the present disclosure provide for solar cells including an organometallic halide perovskite monocrystalline film (see fig. 1.1B), other devices including the organometallic halide perovskite monocrystalline film, methods of making

Electrode assemblies, plasma apparatuses and systems including electrode assemblies, and methods for generating plasma

Science.gov (United States)

Kong, Peter C; Grandy, Jon D; Detering, Brent A; Zuck, Larry D

2013-09-17

Electrode assemblies for plasma reactors include a structure or device for constraining an arc endpoint to a selected area or region on an electrode. In some embodiments, the structure or device may comprise one or more insulating members covering a portion of an electrode. In additional embodiments, the structure or device may provide a magnetic field configured to control a location of an arc endpoint on the electrode. Plasma generating modules, apparatus, and systems include such electrode assemblies. Methods for generating a plasma include covering at least a portion of a surface of an electrode with an electrically insulating member to constrain a location of an arc endpoint on the electrode. Additional methods for generating a plasma include generating a magnetic field to constrain a location of an arc endpoint on an electrode.

Systems and strippable coatings for decontaminating structures that include porous material

Science.gov (United States)

Fox, Robert V [Idaho Falls, ID; Avci, Recep [Bozeman, MT; Groenewold, Gary S [Idaho Falls, ID

2011-12-06

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

Comparison of some biased estimation methods (including ordinary subset regression) in the linear model

Science.gov (United States)

Sidik, S. M.

1975-01-01

Ridge, Marquardt's generalized inverse, shrunken, and principal components estimators are discussed in terms of the objectives of point estimation of parameters, estimation of the predictive regression function, and hypothesis testing. It is found that as the normal equations approach singularity, more consideration must be given to estimable functions of the parameters as opposed to estimation of the full parameter vector; that biased estimators all introduce constraints on the parameter space; that adoption of mean squared error as a criterion of goodness should be independent of the degree of singularity; and that ordinary least-squares subset regression is the best overall method.

Density-functional method for nonequilibrium electron transport

DEFF Research Database (Denmark)

Brandbyge, Mads; Mozos, J.L.; Ordejon, P.

2002-01-01

the contact and the electrodes on the same footing. The effect of the finite bias (including self-consistency and the solution of the electrostatic problem) is taken into account using nonequilibrium Green's functions. We relate the nonequilibrium Green's function expressions to the more transparent scheme...... wires connected to aluminum electrodes with extended or finite cross section, (ii) single atom gold wires, and finally (iii) large carbon nanotube systems with point defects....

A point-value enhanced finite volume method based on approximate delta functions

Science.gov (United States)

Xuan, Li-Jun; Majdalani, Joseph

2018-02-01

We revisit the concept of an approximate delta function (ADF), introduced by Huynh (2011) [1], in the form of a finite-order polynomial that holds identical integral properties to the Dirac delta function when used in conjunction with a finite-order polynomial integrand over a finite domain. We show that the use of generic ADF polynomials can be effective at recovering and generalizing several high-order methods, including Taylor-based and nodal-based Discontinuous Galerkin methods, as well as the Correction Procedure via Reconstruction. Based on the ADF concept, we then proceed to formulate a Point-value enhanced Finite Volume (PFV) method, which stores and updates the cell-averaged values inside each element as well as the unknown quantities and, if needed, their derivatives on nodal points. The sharing of nodal information with surrounding elements saves the number of degrees of freedom compared to other compact methods at the same order. To ensure conservation, cell-averaged values are updated using an identical approach to that adopted in the finite volume method. Here, the updating of nodal values and their derivatives is achieved through an ADF concept that leverages all of the elements within the domain of integration that share the same nodal point. The resulting scheme is shown to be very stable at successively increasing orders. Both accuracy and stability of the PFV method are verified using a Fourier analysis and through applications to the linear wave and nonlinear Burgers' equations in one-dimensional space.

convergent methods for calculating thermodynamic Green functions

OpenAIRE

Bowen, S. P.; Williams, C. D.; Mancini, J. D.

1984-01-01

A convergent method of approximating thermodynamic Green functions is outlined briefly. The method constructs a sequence of approximants which converges independently of the strength of the Hamiltonian's coupling constants. Two new concepts associated with the approximants are introduced: the resolving power of the approximation, and conditional creation (annihilation) operators. These ideas are illustrated on an exactly soluble model and a numerical example. A convergent expression for the s...

Creep analysis by the path function method

International Nuclear Information System (INIS)

Akin, J.E.; Pardue, R.M.

1977-01-01

The finite element method has become a common analysis procedure for the creep analysis of structures. The most recent programs are designed to handle a general class of material properties and are able to calculate elastic, plastic, and creep components of strain under general loading histories. The constant stress approach is too crude a model to accurately represent the actual behaviour of the stress for large time steps. The true path of a point in the effective stress-effective strain (sigmasup(e)-epsilonsup(c)) plane is often one in which the slope is rapidly changing. Thus the stress level quickly moves away from the initial stress level and then gradually approaches the final one. The result is that the assumed constant stress level quickly becomes inaccurate. What is required is a better method of approximation of the true path in the sigmasup(e)-epsilonsup(c) space. The method described here is called the path function approach because it employs an assumed function to estimate the motion of points in the sigmasup(e)-epsilonsup(c) space. (Auth.)

Modulating Function-Based Method for Parameter and Source Estimation of Partial Differential Equations

KAUST Repository

Asiri, Sharefa M.

2017-10-08

Partial Differential Equations (PDEs) are commonly used to model complex systems that arise for example in biology, engineering, chemistry, and elsewhere. The parameters (or coefficients) and the source of PDE models are often unknown and are estimated from available measurements. Despite its importance, solving the estimation problem is mathematically and numerically challenging and especially when the measurements are corrupted by noise, which is often the case. Various methods have been proposed to solve estimation problems in PDEs which can be classified into optimization methods and recursive methods. The optimization methods are usually heavy computationally, especially when the number of unknowns is large. In addition, they are sensitive to the initial guess and stop condition, and they suffer from the lack of robustness to noise. Recursive methods, such as observer-based approaches, are limited by their dependence on some structural properties such as observability and identifiability which might be lost when approximating the PDE numerically. Moreover, most of these methods provide asymptotic estimates which might not be useful for control applications for example. An alternative non-asymptotic approach with less computational burden has been proposed in engineering fields based on the so-called modulating functions. In this dissertation, we propose to mathematically and numerically analyze the modulating functions based approaches. We also propose to extend these approaches to different situations. The contributions of this thesis are as follows. (i) Provide a mathematical analysis of the modulating function-based method (MFBM) which includes: its well-posedness, statistical properties, and estimation errors. (ii) Provide a numerical analysis of the MFBM through some estimation problems, and study the sensitivity of the method to the modulating functions\\' parameters. (iii) Propose an effective algorithm for selecting the method\\'s design parameters

Investigation of MLE in nonparametric estimation methods of reliability function

International Nuclear Information System (INIS)

Ahn, Kwang Won; Kim, Yoon Ik; Chung, Chang Hyun; Kim, Kil Yoo

2001-01-01

There have been lots of trials to estimate a reliability function. In the ESReDA 20 th seminar, a new method in nonparametric way was proposed. The major point of that paper is how to use censored data efficiently. Generally there are three kinds of approach to estimate a reliability function in nonparametric way, i.e., Reduced Sample Method, Actuarial Method and Product-Limit (PL) Method. The above three methods have some limits. So we suggest an advanced method that reflects censored information more efficiently. In many instances there will be a unique maximum likelihood estimator (MLE) of an unknown parameter, and often it may be obtained by the process of differentiation. It is well known that the three methods generally used to estimate a reliability function in nonparametric way have maximum likelihood estimators that are uniquely exist. So, MLE of the new method is derived in this study. The procedure to calculate a MLE is similar just like that of PL-estimator. The difference of the two is that in the new method, the mass (or weight) of each has an influence of the others but the mass in PL-estimator not

The method of images and Green's function for spherical domains

International Nuclear Information System (INIS)

Gutkin, Eugene; Newton, Paul K

2004-01-01

Motivated by problems in electrostatics and vortex dynamics, we develop two general methods for constructing Green's function for simply connected domains on the surface of the unit sphere. We prove a Riemann mapping theorem showing that such domains can be conformally mapped to the upper hemisphere. We then categorize all domains on the sphere for which Green's function can be constructed by an extension of the classical method of images. We illustrate our methods by several examples, such as the upper hemisphere, geodesic triangles, and latitudinal rectangles. We describe the point vortex motion in these domains, which is governed by a Hamiltonian determined by the Dirichlet Green's function

METHOD OF GREEN FUNCTIONS IN MATHEMATICAL MODELLING FOR TWO-POINT BOUNDARY-VALUE PROBLEMS

Directory of Open Access Journals (Sweden)

E. V. Dikareva

2015-01-01

Full Text Available Summary. In many applied problems of control, optimization, system theory, theoretical and construction mechanics, for problems with strings and nods structures, oscillation theory, theory of elasticity and plasticity, mechanical problems connected with fracture dynamics and shock waves, the main instrument for study these problems is a theory of high order ordinary differential equations. This methodology is also applied for studying mathematical models in graph theory with different partitioning based on differential equations. Such equations are used for theoretical foundation of mathematical models but also for constructing numerical methods and computer algorithms. These models are studied with use of Green function method. In the paper first necessary theoretical information is included on Green function method for multi point boundary-value problems. The main equation is discussed, notions of multi-point boundary conditions, boundary functionals, degenerate and non-degenerate problems, fundamental matrix of solutions are introduced. In the main part the problem to study is formulated in terms of shocks and deformations in boundary conditions. After that the main results are formulated. In theorem 1 conditions for existence and uniqueness of solutions are proved. In theorem 2 conditions are proved for strict positivity and equal measureness for a pair of solutions. In theorem 3 existence and estimates are proved for the least eigenvalue, spectral properties and positivity of eigenfunctions. In theorem 4 the weighted positivity is proved for the Green function. Some possible applications are considered for a signal theory and transmutation operators.

Structural properties of metal-organic frameworks within the density-functional based tight-binding method

Energy Technology Data Exchange (ETDEWEB)

Lukose, Binit; Supronowicz, Barbara; Kuc, Agnieszka B.; Heine, Thomas [School of Engineering and Science, Jacobs University Bremen (Germany); Petkov, Petko S.; Vayssilov, Georgi N. [Faculty of Chemistry, University of Sofia (Bulgaria); Frenzel, Johannes [Lehrstuhl fuer Theoretische Chemie, Ruhr-Universitaet Bochum (Germany); Seifert, Gotthard [Physikalische Chemie, Technische Universitaet Dresden (Germany)

2012-02-15

Density-functional based tight-binding (DFTB) is a powerful method to describe large molecules and materials. Metal-organic frameworks (MOFs), materials with interesting catalytic properties and with very large surface areas, have been developed and have become commercially available. Unit cells of MOFs typically include hundreds of atoms, which make the application of standard density-functional methods computationally very expensive, sometimes even unfeasible. The aim of this paper is to prepare and to validate the self-consistent charge-DFTB (SCC-DFTB) method for MOFs containing Cu, Zn, and Al metal centers. The method has been validated against full hybrid density-functional calculations for model clusters, against gradient corrected density-functional calculations for supercells, and against experiment. Moreover, the modular concept of MOF chemistry has been discussed on the basis of their electronic properties. We concentrate on MOFs comprising three common connector units: copper paddlewheels (HKUST-1), zinc oxide Zn{sub 4}O tetrahedron (MOF-5, MOF-177, DUT-6 (MOF-205)), and aluminum oxide AlO{sub 4}(OH){sub 2} octahedron (MIL-53). We show that SCC-DFTB predicts structural parameters with a very good accuracy (with less than 5% deviation, even for adsorbed CO and H{sub 2}O on HKUST-1), while adsorption energies differ by 12 kJ mol{sup -1} or less for CO and water compared to DFT benchmark calculations. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

DESCRIBING FUNCTION METHOD FOR PI-FUZZY CONTROLLED SYSTEMS STABILITY ANALYSIS

Directory of Open Access Journals (Sweden)

Stefan PREITL

2004-12-01

Full Text Available The paper proposes a global stability analysis method dedicated to fuzzy control systems containing Mamdani PI-fuzzy controllers with output integration to control SISO linear / linearized plants. The method is expressed in terms of relatively simple steps, and it is based on: the generalization of the describing function method for the considered fuzzy control systems to the MIMO case, the approximation of the describing functions by applying the least squares method. The method is applied to the stability analysis of a class of PI-fuzzy controlled servo-systems, and validated by considering a case study.

Green's function matching method for adjoining regions having different masses

International Nuclear Information System (INIS)

Morgenstern Horing, Norman J

2006-01-01

We present a primer on the method of Green's function matching for the determination of the global Schroedinger Green's function for all space subject to joining conditions at an interface between two (or more) separate parts of the region having different masses. The object of this technique is to determine the full space Schroedinger Green's function in terms of the individual Green's functions of the constituent parts taken as if they were themselves extended to all space. This analytical method has had successful applications in the theory of surface states, and remains of interest for nanostructures

An advanced probabilistic structural analysis method for implicit performance functions

Science.gov (United States)

Wu, Y.-T.; Millwater, H. R.; Cruse, T. A.

1989-01-01

In probabilistic structural analysis, the performance or response functions usually are implicitly defined and must be solved by numerical analysis methods such as finite element methods. In such cases, the most commonly used probabilistic analysis tool is the mean-based, second-moment method which provides only the first two statistical moments. This paper presents a generalized advanced mean value (AMV) method which is capable of establishing the distributions to provide additional information for reliability design. The method requires slightly more computations than the second-moment method but is highly efficient relative to the other alternative methods. In particular, the examples show that the AMV method can be used to solve problems involving non-monotonic functions that result in truncated distributions.

Solar cells, structures including organometallic halide perovskite monocrystalline films, and methods of preparation thereof

KAUST Repository

Bakr, Osman M.

2017-03-02

Embodiments of the present disclosure provide for solar cells including an organometallic halide perovskite monocrystalline film (see fig. 1.1B), other devices including the organometallic halide perovskite monocrystalline film, methods of making organometallic halide perovskite monocrystalline film, and the like.

Determination of resonance parameters in QCD by functional analysis methods

International Nuclear Information System (INIS)

Ciulli, S.; Geniet, F.; Papadopoulos, N.A.; Schilcher, K.

1988-01-01

A mathematically rigorous method based on functional analysis is used to determine resonance parameters of an amplitude from its given asymptotic expression in the space-like region. This method is checked on a model amplitude where both the asymptotic expression and the exact function are known. This method is then applied to the determination of the mass and the width of the ρ-meson from the corresponding space-like asymptotic QCD expression. (orig.)

Methods of assessing the functional status of patients with left ventricular systolic dysfunction in interventional studies: can brain natriuretic peptide measurement be used as surrogate for the traditional methods?

DEFF Research Database (Denmark)

Abdulla, Jawdat; Køber, Lars; Torp-Pedersen, Christian

2004-01-01

AIM: To review whether brain natriuretic peptides (BNP) can be used as a surrogate for the traditional methods of assessing functional status in interventional studies of patients with left ventricular systolic dysfunction (LVSD). METHODS AND RESULTS: The traditional methods for assessing...... functional status including New York Heart Association (NYHA) class, exercise intolerance and quality of life were reviewed in relation to BNP measurements in patients with LVSD. A meta-analysis of four studies evaluating BNP levels versus exercise peak oxygen uptake or 6-minute walking distance showed...

Method of vacuum correlation functions: Results and prospects

International Nuclear Information System (INIS)

Badalian, A. M.; Simonov, Yu. A.; Shevchenko, V. I.

2006-01-01

Basic results obtained within the QCD method of vacuum correlation functions over the past 20 years in the context of investigations into strong-interaction physics at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) are formulated Emphasis is placed primarily on the prospects of the general theory developed within QCD by employing both nonperturbative and perturbative methods. On the basis of ab initio arguments, it is shown that the lowest two field correlation functions play a dominant role in QCD dynamics. A quantitative theory of confinement and deconfinement, as well as of the spectra of light and heavy quarkonia, glueballs, and hybrids, is given in terms of these two correlation functions. Perturbation theory in a nonperturbative vacuum (background perturbation theory) plays a significant role, not possessing drawbacks of conventional perturbation theory and leading to the infrared freezing of the coupling constant α s

Fast methods for spatially correlated multilevel functional data

KAUST Repository

Staicu, A.-M.

2010-01-19

We propose a new methodological framework for the analysis of hierarchical functional data when the functions at the lowest level of the hierarchy are correlated. For small data sets, our methodology leads to a computational algorithm that is orders of magnitude more efficient than its closest competitor (seconds versus hours). For large data sets, our algorithm remains fast and has no current competitors. Thus, in contrast to published methods, we can now conduct routine simulations, leave-one-out analyses, and nonparametric bootstrap sampling. Our methods are inspired by and applied to data obtained from a state-of-the-art colon carcinogenesis scientific experiment. However, our models are general and will be relevant to many new data sets where the object of inference are functions or images that remain dependent even after conditioning on the subject on which they are measured. Supplementary materials are available at Biostatistics online.

Improved non-dimensional dynamic influence function method based on tow-domain method for vibration analysis of membranes

Directory of Open Access Journals (Sweden)

SW Kang

2015-02-01

Full Text Available This article introduces an improved non-dimensional dynamic influence function method using a sub-domain method for efficiently extracting the eigenvalues and mode shapes of concave membranes with arbitrary shapes. The non-dimensional dynamic influence function method (non-dimensional dynamic influence function method, which was developed by the authors in 1999, gives highly accurate eigenvalues for membranes, plates, and acoustic cavities, compared with the finite element method. However, it needs the inefficient procedure of calculating the singularity of a system matrix in the frequency range of interest for extracting eigenvalues and mode shapes. To overcome the inefficient procedure, this article proposes a practical approach to make the system matrix equation of the concave membrane of interest into a form of algebraic eigenvalue problem. It is shown by several case studies that the proposed method has a good convergence characteristics and yields very accurate eigenvalues, compared with an exact method and finite element method (ANSYS.

Measurement properties of exsisting clinical assessment methods evaluating scapular positioning and function. A systematic review

DEFF Research Database (Denmark)

Larsen, Camilla Marie; Juul-Kristensen, B; Lund, H

(COSMIN checklist), the methodological quality in the reliability and validity domains was ‘fair’ (57%) to ‘poor’ (43%), with only one study rated as ‘good’. The reliability domain was most often investigated. Fewof the assessment methods in the included studies that had ‘fair’ or ‘good’ measurement......MEASUREMENT PROPERTIES OF EXISTING CLINICAL ASSESSMENT METHODS EVALUATING SCAPULAR POSITIONING AND FUNCTION. A SYSTEMATIC REVIEW1,2Camilla Marie Larsen, 1,3Birgit Juul-Kristensen, 1,3Hans Lund, 1Karen Søgaard1Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark2......,2]. Rehabilitation exercises are aiming at altering abnormal/asymmetric scapular positioning and/or function. Numerous assessment methods have measured the degree of scapular dyskinesis, subjectively by visual evaluation and objectively by measurements of static and dynamic scapular positioning, by either a 3...

Application of the Green's function method to some nonlinear problems of an electron storage ring

International Nuclear Information System (INIS)

Kheifets, S.

1984-01-01

One of the most important characteristics of an electron storage ring is the size of the beam. However analytical calculations of beam size are beset with problems and the computational methods and programs which are used to overcome these are inadequate for all problems in which stochastic noise is an essential part. Two examples are, for an electron storage ring, beam-size evaluation including beam-beam interactions, and finding the beam size for a nonlinear machine. The method described should overcome some of the problems. It uses the Green's function method applied to the Fokker-Planck equation governing the distribution function in the phase space of particle motion. The new step is to consider the particle motion in two degrees of freedom rather than in one dimension. The technique is described fully and is then applied to a strong-focusing machine. (U.K.)

Heuristic method for searching global maximum of multimodal unknown function

Energy Technology Data Exchange (ETDEWEB)

Kamei, K; Araki, Y; Inoue, K

1983-06-01

The method is composed of three kinds of searches. They are called g (grasping)-mode search, f (finding)-mode search and c (confirming)-mode search. In the g-mode search and the c-mode search, a heuristic method is used which was extracted from search behaviors of human subjects. In f-mode search, the simplex method is used which is well known as a search method for unimodal unknown function. Each mode search and its transitions are shown in the form of flowchart. The numerical results for one-dimensional through six-dimensional multimodal functions prove the proposed search method to be an effective one. 11 references.

TS Fuzzy Model-Based Controller Design for a Class of Nonlinear Systems Including Nonsmooth Functions

DEFF Research Database (Denmark)

Vafamand, Navid; Asemani, Mohammad Hassan; Khayatiyan, Alireza

2018-01-01

This paper proposes a novel robust controller design for a class of nonlinear systems including hard nonlinearity functions. The proposed approach is based on Takagi-Sugeno (TS) fuzzy modeling, nonquadratic Lyapunov function, and nonparallel distributed compensation scheme. In this paper, a novel...... criterion, new robust controller design conditions in terms of linear matrix inequalities are derived. Three practical case studies, electric power steering system, a helicopter model and servo-mechanical system, are presented to demonstrate the importance of such class of nonlinear systems comprising...

Earthquake analysis of structures including structure-soil interaction by a substructure method

International Nuclear Information System (INIS)

Chopra, A.K.; Guttierrez, J.A.

1977-01-01

A general substructure method for analysis of response of nuclear power plant structures to earthquake ground motion, including the effects of structure-soil interaction, is summarized. The method is applicable to complex structures idealized as finite element systems and the soil region treated as either a continuum, for example as a viscoelastic halfspace, or idealized as a finite element system. The halfspace idealization permits reliable analysis for sites where essentially similar soils extend to large depths and there is no rigid boundary such as soil-rock interface. For sites where layers of soft soil are underlain by rock at shallow depth, finite element idealization of the soil region is appropriate; in this case, the direct and substructure methods would lead to equivalent results but the latter provides the better alternative. Treating the free field motion directly as the earthquake input in the substructure eliminates the deconvolution calculations and the related assumption-regarding type and direction of earthquake waves-required in the direct method. (Auth.)

Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

Directory of Open Access Journals (Sweden)

Hai-peng Wang

2017-01-01

Full Text Available Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. Through a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a prototype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist flexion/extension, hand grasp, and finger extension could be reproduced with high accuracy and low latency. This system can build a bridge of information transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate efficiency of rehabilitation training.

On some methods of NPP functional diagnostics

International Nuclear Information System (INIS)

Babkin, N.A.

1988-01-01

Methods for NPP functional diagnosis, in which space and time dependences for controlled variable anomalous deviations change are used as characteristic features, are suggested. The methods are oriented for operative recognition of suddenly appearing defects and envelop quite a wide range of possible anomalous effects in an onject under diagnostics. Analysis of transients dynamic properties caused by a failure is realized according to the rules, which do not depend on the character of anomalous situation development

Exponential function method for solving nonlinear ordinary ...

Indian Academy of Sciences (India)

[14] introduced a new system of rational. 79 ..... Also, for k-power of function f (η), by induction, we have ..... reliability and efficiency of the method. .... electric field and the polarization effects are negligible and B(x) is assumed by Chaim [8] as.

Methods of filtering the graph images of the functions

Directory of Open Access Journals (Sweden)

Олександр Григорович Бурса

2017-06-01

Full Text Available The theoretical aspects of cleaning raster images of scanned graphs of functions from digital, chromatic and luminance distortions by using computer graphics techniques have been considered. The basic types of distortions characteristic of graph images of functions have been stated. To suppress the distortion several methods, providing for high-quality of the resulting images and saving their topological features, were suggested. The paper describes the techniques developed and improved by the authors: the method of cleaning the image of distortions by means of iterative contrasting, based on the step-by-step increase in image contrast in the graph by 1%; the method of small entities distortion restoring, based on the thinning of the known matrix of contrast increase filter (the allowable dimensions of the nucleus dilution radius convolution matrix, which provide for the retention of the graph lines have been established; integration technique of the noise reduction method by means of contrasting and distortion restoring method of small entities with known σ-filter. Each method in the complex has been theoretically substantiated. The developed methods involve treatment of graph images as the entire image (global processing and its fragments (local processing. The metrics assessing the quality of the resulting image with the global and local processing have been chosen, the substantiation of the choice as well as the formulas have been given. The proposed complex methods of cleaning the graphs images of functions from grayscale image distortions is adaptive to the form of an image carrier, the distortion level in the image and its distribution. The presented results of testing the developed complex of methods for a representative sample of images confirm its effectiveness

Penalty parameter of the penalty function method

DEFF Research Database (Denmark)

Si, Cheng Yong; Lan, Tian; Hu, Junjie

2014-01-01

The penalty parameter of penalty function method is systematically analyzed and discussed. For the problem that Deb's feasibility-based rule doesnot give the detailed instruction as how to rank two solutions when they have the same constraint violation, an improved Deb's feasibility-based rule is...

Quality functions for requirements engineering in system development methods.

Science.gov (United States)

Johansson, M; Timpka, T

1996-01-01

Based on a grounded theory framework, this paper analyses the quality characteristics for methods to be used for requirements engineering in the development of medical decision support systems (MDSS). The results from a Quality Function Deployment (QFD) used to rank functions connected to user value and a focus group study were presented to a validation focus group. The focus group studies take advantage of a group process to collect data for further analyses. The results describe factors considered by the participants as important in the development of methods for requirements engineering in health care. Based on the findings, the content which, according to the user a MDSS method should support is established.

A New Method for Deriving the Stellar Birth Function of Resolved Stellar Populations.

Science.gov (United States)

Gennaro, M.; Tchernyshyov, K.; Brown, T. M.; Gordon, K. D.

2015-07-01

We present a new method for deriving the stellar birth function (SBF) of resolved stellar populations. The SBF (stars born per unit mass, time, and metallicity) is the combination of the initial mass function (IMF), the star formation history (SFH), and the metallicity distribution function (MDF). The framework of our analysis is that of Poisson Point Processes (PPPs), a class of statistical models suitable when dealing with points (stars) in a multidimensional space (the measurement space of multiple photometric bands). The theory of PPPs easily accommodates the modeling of measurement errors as well as that of incompleteness. Our method avoids binning stars in the color-magnitude diagram and uses the whole likelihood function for each data point; combining the individual likelihoods allows the computation of the posterior probability for the population's SBF. Within the proposed framework it is possible to include nuisance parameters, such as distance and extinction, by specifying their prior distributions and marginalizing over them. The aim of this paper is to assess the validity of this new approach under a range of assumptions, using only simulated data. Forthcoming work will show applications to real data. Although it has a broad scope of possible applications, we have developed this method to study multi-band Hubble Space Telescope observations of the Milky Way Bulge. Therefore we will focus on simulations with characteristics similar to those of the Galactic Bulge. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Critical node treatment in the analytic function expansion method for Pin Power Reconstruction

International Nuclear Information System (INIS)

Gao, Z.; Xu, Y.; Downar, T.

2013-01-01

Pin Power Reconstruction (PPR) was implemented in PARCS using the eight term analytic function expansion method (AFEN). This method has been demonstrated to be both accurate and efficient. However, similar to all the methods involving analytic functions, such as the analytic node method (ANM) and AFEN for nodal solution, the use of AFEN for PPR also has potential numerical issue with critical nodes. The conventional analytic functions are trigonometric or hyperbolic sine or cosine functions with an angular frequency proportional to buckling. For a critic al node the buckling is zero and the sine functions becomes zero, and the cosine function become unity. In this case, the eight terms of the analytic functions are no longer distinguishable from ea ch other which makes their corresponding coefficients can no longer be determined uniquely. The mode flux distribution of critical node can be linear while the conventional analytic functions can only express a uniform distribution. If there is critical or near critical node in a plane, the reconstructed pin power distribution is often be shown negative or very large values using the conventional method. In this paper, we propose a new method to avoid the numerical problem wit h critical nodes which uses modified trigonometric or hyperbolic sine functions which are the ratio of trigonometric or hyperbolic sine and its angular frequency. If there are no critical or near critical nodes present, the new pin power reconstruction method with modified analytic functions are equivalent to the conventional analytic functions. The new method is demonstrated using the L336C5 benchmark problem. (authors)

Critical node treatment in the analytic function expansion method for Pin Power Reconstruction

Energy Technology Data Exchange (ETDEWEB)

Gao, Z. [Rice University, MS 318, 6100 Main Street, Houston, TX 77005 (United States); Xu, Y. [Argonne National Laboratory, 9700 South Case Ave., Argonne, IL 60439 (United States); Downar, T. [Department of Nuclear Engineering, University of Michigan, 2355 Bonisteel blvd., Ann Arbor, MI 48109 (United States)

2013-07-01

Pin Power Reconstruction (PPR) was implemented in PARCS using the eight term analytic function expansion method (AFEN). This method has been demonstrated to be both accurate and efficient. However, similar to all the methods involving analytic functions, such as the analytic node method (ANM) and AFEN for nodal solution, the use of AFEN for PPR also has potential numerical issue with critical nodes. The conventional analytic functions are trigonometric or hyperbolic sine or cosine functions with an angular frequency proportional to buckling. For a critic al node the buckling is zero and the sine functions becomes zero, and the cosine function become unity. In this case, the eight terms of the analytic functions are no longer distinguishable from ea ch other which makes their corresponding coefficients can no longer be determined uniquely. The mode flux distribution of critical node can be linear while the conventional analytic functions can only express a uniform distribution. If there is critical or near critical node in a plane, the reconstructed pin power distribution is often be shown negative or very large values using the conventional method. In this paper, we propose a new method to avoid the numerical problem wit h critical nodes which uses modified trigonometric or hyperbolic sine functions which are the ratio of trigonometric or hyperbolic sine and its angular frequency. If there are no critical or near critical nodes present, the new pin power reconstruction method with modified analytic functions are equivalent to the conventional analytic functions. The new method is demonstrated using the L336C5 benchmark problem. (authors)

A method for estimating DMSA SPECT renal function for assessing the effect of percutaneous nephrolithotripsy on the treated pole

International Nuclear Information System (INIS)

AGUIAR, Pablo; RUIBAL, Álvaro; CORTÉS, Julia; PÉREZ-FENTES, Daniel; GARCÍA, Camilo; GARRIDO, Miguel

2016-01-01

The aim of this study was to develop a method for estimating DMSA SPECT renal function on each renal pole in order to evaluate the effect of percutaneous nephrolithotripsy by focusing the measurements on the region through which the percutaneous approach is performed. Twenty patients undergoing percutaneous nephrolithotripsy between November 2010 and June 2012 were included in this study. Both Planar and SPECT-DMSA studies were carried out before and after nephrolithotripsy. The effect of percutaneous nephrolithotripsy was evaluated by estimating the total renal function and the regional renal function of each renal pole. Despite PCNL has been previously reported as a minimally invasive technique, our results showed regional renal function decreases in the treated pole in most patients, affecting the total renal function in a few of them. A quantification method was used for estimating the SPECT DMSA renal function of the upper, inter polar and lower renal poles. Our results confirmed that total renal function was preserved after nephrolithotripsy. Nevertheless, the proposed method showed that the regional renal function of the treated pole decreased in most patients (15 of 20 patients), allowing us to find differences in patients who had not shown changes in the total renal function obtained from conventional quantification methods. In conclusion, a method for estimating the SPECT DMSA renal function focused on the treated pole enabled us to show for the first time that nephrolithotripsy can lead to a renal parenchymal damage restricted to the treated pole.

A Comparative Density Functional Theory and Density Functional Tight Binding Study of Phases of Nitrogen Including a High Energy Density Material N8

Directory of Open Access Journals (Sweden)

Nicholas Capel

2015-11-01

Full Text Available We present a comparative dispersion-corrected Density Functional Theory (DFT and Density Functional Tight Binding (DFTB-D study of several phases of nitrogen, including the well-known alpha, beta, and gamma phases as well as recently discovered highly energetic phases: covalently bound cubic gauche (cg nitrogen and molecular (vdW-bound N8 crystals. Among several tested parametrizations of N–N interactions for DFTB, we identify only one that is suitable for modeling of all these phases. This work therefore establishes the applicability of DFTB-D to studies of phases, including highly metastable phases, of nitrogen, which will be of great use for modelling of dynamics of reactions involving these phases, which may not be practical with DFT due to large required space and time scales. We also derive a dispersion-corrected DFT (DFT-D setup (atom-centered basis parameters and Grimme dispersion parameters tuned for accurate description simultaneously of several nitrogen allotropes including covalently and vdW-bound crystals and including high-energy phases.

Exact traveling wave solutions of fractional order Boussinesq-like equations by applying Exp-function method

Directory of Open Access Journals (Sweden)

Rahmatullah

2018-03-01

Full Text Available We have computed new exact traveling wave solutions, including complex solutions of fractional order Boussinesq-Like equations, occurring in physical sciences and engineering, by applying Exp-function method. The method is blended with fractional complex transformation and modified Riemann-Liouville fractional order operator. Our obtained solutions are verified by substituting back into their corresponding equations. To the best of our knowledge, no other technique has been reported to cope with the said fractional order nonlinear problems combined with variety of exact solutions. Graphically, fractional order solution curves are shown to be strongly related to each other and most importantly, tend to fixate on their integer order solution curve. Our solutions comprise high frequencies and very small amplitude of the wave responses. Keywords: Exp-function method, New exact traveling wave solutions, Modified Riemann-Liouville derivative, Fractional complex transformation, Fractional order Boussinesq-like equations, Symbolic computation

SYNTHESIS METHODS OF ALGEBRAIC NORMAL FORM OF MANY-VALUED LOGIC FUNCTIONS

Directory of Open Access Journals (Sweden)

A. V. Sokolov

2016-01-01

Full Text Available The rapid development of methods of error-correcting coding, cryptography, and signal synthesis theory based on the principles of many-valued logic determines the need for a more detailed study of the forms of representation of functions of many-valued logic. In particular the algebraic normal form of Boolean functions, also known as Zhegalkin polynomial, that well describe many of the cryptographic properties of Boolean functions is widely used. In this article, we formalized the notion of algebraic normal form for many-valued logic functions. We developed a fast method of synthesis of algebraic normal form of 3-functions and 5-functions that work similarly to the Reed-Muller transform for Boolean functions: on the basis of recurrently synthesized transform matrices. We propose the hypothesis, which determines the rules of the synthesis of these matrices for the transformation from the truth table to the coefficients of the algebraic normal form and the inverse transform for any given number of variables of 3-functions or 5-functions. The article also introduces the definition of algebraic degree of nonlinearity of the functions of many-valued logic and the S-box, based on the principles of many-valued logic. Thus, the methods of synthesis of algebraic normal form of 3-functions applied to the known construction of recurrent synthesis of S-boxes of length N = 3k, whereby their algebraic degrees of nonlinearity are computed. The results could be the basis for further theoretical research and practical applications such as: the development of new cryptographic primitives, error-correcting codes, algorithms of data compression, signal structures, and algorithms of block and stream encryption, all based on the perspective principles of many-valued logic. In addition, the fast method of synthesis of algebraic normal form of many-valued logic functions is the basis for their software and hardware implementation.

Ankle-brachial index by automated method and renal function

Directory of Open Access Journals (Sweden)

Ricardo Pereira Silva

2017-05-01

Full Text Available Background The Ankle-brachial index (ABI is a non-invasive method used for the diagnosis of peripheral arterial occlusive disease (PAOD. Aims To determine the clinical features of patients submitted to ABI measurement by automatic method. To investigate association between ABI and renal function. Methods The present is a cross-sectional study. The study was performed in a private clinic in the city of Fortaleza (Ce- Brazil. For ABI analysis, we utilized automatic methodology using a Microlife device. Data collection took place from March 2012 to January 2016. During this period, ABI was measured in 375 patients aged >50 years, who had a diagnosis of hypertension, diabetes or vascular disease. Results Of the 375 patients, 18 were categorized as having abnormal ABI (4.8 per cent and 357 were normal ABI (95.2 per cent. Patients with abnormal ABI showed older mean age when compared to patients with normal ABI. Among patients with normal renal function, only 0.95 per cent showed abnormal ABI; among patients with abnormal renal function, 6 per cent showed abnormal ABI. Conclusion 1 No differences were observed when comparing the groups regarding gender or the prevalence of hypertension, diabetes, dyslipidaemia or CAD. 2 Group with abnormal ABI had renal function greater impairment.

On a method for generating inequalities for the zeros of certain functions

Science.gov (United States)

Gatteschi, Luigi; Giordano, Carla

2007-10-01

In this paper we describe a general procedure which yields inequalities satisfied by the zeros of a given function. The method requires the knowledge of a two-term approximation of the function with bound for the error term. The method was successfully applied many years ago [L. Gatteschi, On the zeros of certain functions with application to Bessel functions, Nederl. Akad. Wetensch. Proc. Ser. 55(3)(1952), Indag. Math. 14(1952) 224-229] and more recently too [L. Gatteschi and C. Giordano, Error bounds for McMahon's asymptotic approximations of the zeros of the Bessel functions, Integral Transform Special Functions, 10(2000) 41-56], to the zeros of the Bessel functions of the first kind. Here, we present the results of the application of the method to get inequalities satisfied by the zeros of the derivative of the function . This function plays an important role in the asymptotic study of the stationary points of the solutions of certain differential equations.

Functional discriminant method and neuronal net

International Nuclear Information System (INIS)

Minh-Quan Tran.

1993-02-01

The ZEUS detector at the ep storage ring HERA at DESY is equipped with a 3 level trigger system. This enormous effort is necessary to fight against the high proton beamgas background that was estimated to be at the level of 100 kHz. In this thesis two methods were investigated to calculate a trigger decision from a set of various trigger parameters. The Functional Discriminant Analysis evalutes a decision parameter that is optimized by means of a linear algebra technic. A method is shown how to determine the most important trigger parameters. A 'feed forward' neuralnetwork was analyzed in order to allow none lineare cuts in the n dimensinal configuration space spanned by the trigger parameters. The error back propagation method was used to teach the neural network. It is shown that both decision methods are able to abstract the important characteristics of event samples. As soon as they are tought they will seperate events from these classes even though they were not part of the training sample. (orig.) [de

Some Remarks on Exp-Function Method and Its Applications

International Nuclear Information System (INIS)

Aslan Ismail; Marinakis Vangelis

2011-01-01

Recently, many important nonlinear partial differential equations arising in the applied physical and mathematical sciences have been tackled by a popular approach, the so-called Exp-function method. In this paper, we present some shortcomings of this method by analyzing the results of recently published papers. We also discuss the possible improvement of the effectiveness of the method. (general)

Transfer Function Identification Using Orthogonal Fourier Transform Modeling Functions

Science.gov (United States)

Morelli, Eugene A.

2013-01-01

A method for transfer function identification, including both model structure determination and parameter estimation, was developed and demonstrated. The approach uses orthogonal modeling functions generated from frequency domain data obtained by Fourier transformation of time series data. The method was applied to simulation data to identify continuous-time transfer function models and unsteady aerodynamic models. Model fit error, estimated model parameters, and the associated uncertainties were used to show the effectiveness of the method for identifying accurate transfer function models from noisy data.

Quantal density functional theory II. Approximation methods and applications

International Nuclear Information System (INIS)

Sahni, Viraht

2010-01-01

This book is on approximation methods and applications of Quantal Density Functional Theory (QDFT), a new local effective-potential-energy theory of electronic structure. What distinguishes the theory from traditional density functional theory is that the electron correlations due to the Pauli exclusion principle, Coulomb repulsion, and the correlation contribution to the kinetic energy -- the Correlation-Kinetic effects -- are separately and explicitly defined. As such it is possible to study each property of interest as a function of the different electron correlations. Approximations methods based on the incorporation of different electron correlations, as well as a many-body perturbation theory within the context of QDFT, are developed. The applications are to the few-electron inhomogeneous electron gas systems in atoms and molecules, as well as to the many-electron inhomogeneity at metallic surfaces. (orig.)

Quantum statistical field theory an introduction to Schwinger's variational method with Green's function nanoapplications, graphene and superconductivity

CERN Document Server

Morgenstern Horing, Norman J

2017-01-01

This book provides an introduction to the methods of coupled quantum statistical field theory and Green's functions. The methods of coupled quantum field theory have played a major role in the extensive development of nonrelativistic quantum many-particle theory and condensed matter physics. This introduction to the subject is intended to facilitate delivery of the material in an easily digestible form to advanced undergraduate physics majors at a relatively early stage of their scientific development. The main mechanism to accomplish this is the early introduction of variational calculus and the Schwinger Action Principle, accompanied by Green's functions. Important achievements of the theory in condensed matter and quantum statistical physics are reviewed in detail to help develop research capability. These include the derivation of coupled field Green's function equations-of-motion for a model electron-hole-phonon system, extensive discussions of retarded, thermodynamic and nonequilibrium Green's functions...

Orbital-dependent exchange-correlation functionals in density-functional theory realized by the FLAPW method

Energy Technology Data Exchange (ETDEWEB)

Betzinger, Markus

2011-12-14

In this thesis, we extended the applicability of the full-potential linearized augmented-plane-wave (FLAPW) method, one of the most precise, versatile and generally applicable electronic structure methods for solids working within the framework of density-functional theory (DFT), to orbital-dependent functionals for the exchange-correlation (xc) energy. Two different schemes that deal with orbital-dependent functionals, the Kohn-Sham (KS) and the generalized Kohn-Sham (gKS) formalism, have been realized. Hybrid functionals, combining some amount of the orbital-dependent exact exchange energy with local or semi-local functionals of the density, are implemented within the gKS scheme. We work in particular with the PBE0 hybrid of Perdew, Burke, and Ernzerhof. Our implementation relies on a representation of the non-local exact exchange potential - its calculation constitutes the most time consuming step in a practical calculation - by an auxiliary mixed product basis (MPB). In this way, the matrix elements of the Hamiltonian corresponding to the non-local potential become a Brillouin-zone (BZ) sum over vector-matrix-vector products. Several techniques are developed and explored to further accelerate our numerical scheme. We show PBE0 results for a variety of semiconductors and insulators. In comparison with experiment, the PBE0 functional leads to improved band gaps and an improved description of localized states. Even for the ferromagnetic semiconductor EuO with localized 4f electrons, the electronic and magnetic properties are correctly described by the PBE0 functional. Subsequently, we discuss the construction of the local, multiplicative exact exchange (EXX) potential from the non-local, orbital-dependent exact exchange energy. For this purpose we employ the optimized effective potential (OEP) method. Central ingredients of the OEP equation are the KS wave-function response and the single-particle density response function. We show that a balance between the LAPW

Orbital-dependent exchange-correlation functionals in density-functional theory realized by the FLAPW method

International Nuclear Information System (INIS)

Betzinger, Markus

2011-01-01

In this thesis, we extended the applicability of the full-potential linearized augmented-plane-wave (FLAPW) method, one of the most precise, versatile and generally applicable electronic structure methods for solids working within the framework of density-functional theory (DFT), to orbital-dependent functionals for the exchange-correlation (xc) energy. Two different schemes that deal with orbital-dependent functionals, the Kohn-Sham (KS) and the generalized Kohn-Sham (gKS) formalism, have been realized. Hybrid functionals, combining some amount of the orbital-dependent exact exchange energy with local or semi-local functionals of the density, are implemented within the gKS scheme. We work in particular with the PBE0 hybrid of Perdew, Burke, and Ernzerhof. Our implementation relies on a representation of the non-local exact exchange potential - its calculation constitutes the most time consuming step in a practical calculation - by an auxiliary mixed product basis (MPB). In this way, the matrix elements of the Hamiltonian corresponding to the non-local potential become a Brillouin-zone (BZ) sum over vector-matrix-vector products. Several techniques are developed and explored to further accelerate our numerical scheme. We show PBE0 results for a variety of semiconductors and insulators. In comparison with experiment, the PBE0 functional leads to improved band gaps and an improved description of localized states. Even for the ferromagnetic semiconductor EuO with localized 4f electrons, the electronic and magnetic properties are correctly described by the PBE0 functional. Subsequently, we discuss the construction of the local, multiplicative exact exchange (EXX) potential from the non-local, orbital-dependent exact exchange energy. For this purpose we employ the optimized effective potential (OEP) method. Central ingredients of the OEP equation are the KS wave-function response and the single-particle density response function. We show that a balance between the LAPW

The analytic regularization ζ function method and the cut-off method in Casimir effect

International Nuclear Information System (INIS)

Svaiter, N.F.; Svaiter, B.F.

1990-01-01

The zero point energy associated to a hermitian massless scalar field in the presence of perfectly reflecting plates in a three dimensional flat space-time is discussed. A new technique to unify two different methods - the ζ function and a variant of the cut-off method - used to obtain the so called Casimir energy is presented, and the proof of the analytic equivalence between both methods is given. (author)

The Innovative Bike Conceptual Design by Using Modified Functional Element Design Method

Directory of Open Access Journals (Sweden)

Nien-Te Liu

2016-11-01

Full Text Available The purpose of the study is to propose a new design process by modifying functional element design approach which can commence a large amount of innovative concepts within a short period of time. Firstly, the original creative functional elements design method is analyzed and the drawbacks are discussed. Then, the modified is proposed and is divided into 6 steps. The creative functional element representations, generalization, specialization, and particularization are used in this method. Every step is described clearly, and users could design by following the process easily. In this paper, a clear and accurate design process is proposed based on the creative functional element design method. By following this method, a lot of innovative bicycles will be created quickly.

On the Reliability of Source Time Functions Estimated Using Empirical Green's Function Methods

Science.gov (United States)

Gallegos, A. C.; Xie, J.; Suarez Salas, L.

2017-12-01

The Empirical Green's Function (EGF) method (Hartzell, 1978) has been widely used to extract source time functions (STFs). In this method, seismograms generated by collocated events with different magnitudes are deconvolved. Under a fundamental assumption that the STF of the small event is a delta function, the deconvolved Relative Source Time Function (RSTF) yields the large event's STF. While this assumption can be empirically justified by examination of differences in event size and frequency content of the seismograms, there can be a lack of rigorous justification of the assumption. In practice, a small event might have a finite duration when the RSTF is retrieved and interpreted as the large event STF with a bias. In this study, we rigorously analyze this bias using synthetic waveforms generated by convolving a realistic Green's function waveform with pairs of finite-duration triangular or parabolic STFs. The RSTFs are found using a time-domain based matrix deconvolution. We find when the STFs of smaller events are finite, the RSTFs are a series of narrow non-physical spikes. Interpreting these RSTFs as a series of high-frequency source radiations would be very misleading. The only reliable and unambiguous information we can retrieve from these RSTFs is the difference in durations and the moment ratio of the two STFs. We can apply a Tikhonov smoothing to obtain a single-pulse RSTF, but its duration is dependent on the choice of weighting, which may be subjective. We then test the Multi-Channel Deconvolution (MCD) method (Plourde & Bostock, 2017) which assumes that both STFs have finite durations to be solved for. A concern about the MCD method is that the number of unknown parameters is larger, which would tend to make the problem rank-deficient. Because the kernel matrix is dependent on the STFs to be solved for under a positivity constraint, we can only estimate the rank-deficiency with a semi-empirical approach. Based on the results so far, we find that the

Perturbation methods and the Melnikov functions for slowly varying oscillators

International Nuclear Information System (INIS)

Lakrad, Faouzi; Charafi, Moulay Mustapha

2005-01-01

A new approach to obtaining the Melnikov function for homoclinic orbits in slowly varying oscillators is proposed. The present method applies the Lindstedt-Poincare method to determine an approximation of homoclinic solutions. It is shown that the resultant Melnikov condition is the same as that obtained in the usual way involving distance functions in three dimensions by Wiggins and Holmes [Homoclinic orbits in slowly varying oscillators. SIAM J Math Anal 1987;18(3):612

Earthquake analysis of structures including structure-soil interaction by a substructure method

International Nuclear Information System (INIS)

Chopra, A.K.; Guttierrez, J.A.

1977-01-01

A general substructure method for analysis of response of nuclear power plant structures to earthquake ground motion, including the effects of structure-soil interaction, is summarized. The method is applicable to complex structures idealized as finite element systems and the soil region treated as either a continuum, for example as a viscoelastic halfspace, or idealized as a finite element system. The halfspace idealization permits reliable analysis for sites where essentially similar soils extend to large depths and there is no rigid boundary such as soil-rock interface. For sites where layers of soft soil are underlain by rock at shallow depth, finite element idealization of the soil region is appropriate; in this case, the direct and substructure methods would lead to equivalent results but the latter provides the better alternative. Treating the free field motion directly as the earthquake input in the substructure method eliminates the deconvolution calculations and the related assumption -regarding type and direction of earthquake waves- required in the direct method. The substructure method is computationally efficient because the two substructures-the structure and the soil region- are analyzed separately; and, more important, it permits taking advantage of the important feature that response to earthquake ground motion is essentially contained in the lower few natural modes of vibration of the structure on fixed base. For sites where essentially similar soils extend to large depths and there is no obvious rigid boundary such as a soil-rock interface, numerical results for earthquake response of a nuclear reactor structure are presented to demonstrate that the commonly used finite element method may lead to unacceptable errors; but the substructure method leads to reliable results

Minimizing convex functions by continuous descent methods

Directory of Open Access Journals (Sweden)

Sergiu Aizicovici

2010-01-01

Full Text Available We study continuous descent methods for minimizing convex functions, defined on general Banach spaces, which are associated with an appropriate complete metric space of vector fields. We show that there exists an everywhere dense open set in this space of vector fields such that each of its elements generates strongly convergent trajectories.

Iterative method of the parameter variation for solution of nonlinear functional equations

International Nuclear Information System (INIS)

Davidenko, D.F.

1975-01-01

The iteration method of parameter variation is used for solving nonlinear functional equations in Banach spaces. The authors consider some methods for numerical integration of ordinary first-order differential equations and construct the relevant iteration methods of parameter variation, both one- and multifactor. They also discuss problems of mathematical substantiation of the method, study the conditions and rate of convergence, estimate the error. The paper considers the application of the method to specific functional equations

An Influence Function Method for Predicting Store Aerodynamic Characteristics during Weapon Separation,

Science.gov (United States)

1981-05-14

8217 AO-Ail 777 GRUMMAN AEROSPACE CORP BETHPAGE NY F/G 20/4 AN INFLUENCE FUNCTION METHOD FOR PREDICTING STORE AERODYNAMIC C--ETCCU) MAY 8 1 R MEYER, A...CENKO, S YARDS UNCLASSIFIED N ’.**~~N**n I EHEEKI j~j .25 Q~4 111110 111_L 5. AN INFLUENCE FUNCTION METHOD FOR PREDICTING STORE AERODYNAMIC...extended to their logical conclusion one is led quite naturally to consideration of an " Influence Function Method" for I predicting store aerodynamic

New method for minimizing regular functions with constraints on parameter region

International Nuclear Information System (INIS)

Kurbatov, V.S.; Silin, I.N.

1993-01-01

The new method of function minimization is developed. Its main features are considered. It is possible minimization of regular function with the arbitrary structure. For χ 2 -like function the usage of simplified second derivatives is possible with the control of correctness. The constraints of arbitrary structure can be used. The means for fast movement along multidimensional valleys are used. The method is tested on real data of K π2 decay of the experiment on rare K - -decays. 6 refs

25 CFR 1000.361 - Will the annual review include a review of the Secretary's residual trust functions?

Science.gov (United States)

2010-04-01

... Evaluations § 1000.361 Will the annual review include a review of the Secretary's residual trust functions... Department official will be notified of the need for corrective action. The review of the Secretary's trust... 25 Indians 2 2010-04-01 2010-04-01 false Will the annual review include a review of the Secretary...

General Retarded Contact Self-energies in and beyond the Non-equilibrium Green's Functions Method

Science.gov (United States)

Kubis, Tillmann; He, Yu; Andrawis, Robert; Klimeck, Gerhard

2016-03-01

Retarded contact self-energies in the framework of nonequilibrium Green's functions allow to model the impact of lead structures on the device without explicitly including the leads in the actual device calculation. Most of the contact self-energy algorithms are limited to homogeneous or periodic, semi-infinite lead structures. In this work, the complex absorbing potential method is extended to solve retarded contact self-energies for arbitrary lead structures, including irregular and randomly disordered leads. This method is verified for regular leads against common approaches and on physically equivalent, but numerically different irregular leads. Transmission results on randomly alloyed In0.5Ga0.5As structures show the importance of disorder in the leads. The concept of retarded contact self-energies is expanded to model passivation of atomically resolved surfaces without explicitly increasing the device's Hamiltonian.

MIMIC Methods for Assessing Differential Item Functioning in Polytomous Items

Science.gov (United States)

Wang, Wen-Chung; Shih, Ching-Lin

2010-01-01

Three multiple indicators-multiple causes (MIMIC) methods, namely, the standard MIMIC method (M-ST), the MIMIC method with scale purification (M-SP), and the MIMIC method with a pure anchor (M-PA), were developed to assess differential item functioning (DIF) in polytomous items. In a series of simulations, it appeared that all three methods…

van der Waals forces in density functional theory: a review of the vdW-DF method.

Science.gov (United States)

Berland, Kristian; Cooper, Valentino R; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T; Hyldgaard, Per; Lundqvist, Bengt I

2015-06-01

A density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology is reviewed. The insights that led to the construction of the Rutgers-Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only for dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.

The Green's function method for critical heterogeneous slabs

International Nuclear Information System (INIS)

Kornreich, D.E.

1996-01-01

Recently, the Green's Function Method (GFM) has been employed to obtain benchmark-quality results for nuclear engineering and radiative transfer calculations. This was possible because of fast and accurate calculations of the Green's function and the associated Fourier and Laplace transform inversions. Calculations have been provided in one-dimensional slab geometries for both homogeneous and heterogeneous media. A heterogeneous medium is analyzed as a series of homogeneous slabs, and Placzek's lemma is used to extend each slab to infinity. This allows use of the infinite medium Green's function (the anisotropic plane source in an infinite homogeneous medium) in the solution. To this point, a drawback of the GFM has been the limitation to media with c 1; however, mathematical solutions exist which result in oscillating Green's functions. Such calculations are briefly discussing. The limitation to media with c < 1 has been relaxed so that the Green's function may also be calculated for media with c ≥ 1. Thus, materials that contain fissionable isotopes may be modeled

Rational function approximation method for discrete ordinates problems in slab geometry

International Nuclear Information System (INIS)

Leal, Andre Luiz do C.; Barros, Ricardo C.

2009-01-01

In this work we use rational function approaches to obtain the transfer functions that appear in the spectral Green's function (SGF) auxiliary equations for one-speed isotropic scattering SN equations in one-dimensional Cartesian geometry. For this task we use the computation of the Pade approximants to compare the results with the standard SGF method's applied to deep penetration problems in homogeneous domains. This work is a preliminary investigation of a new proposal for handling leakage terms that appear in the two transverse integrated one-dimensional SN equations in the exponential SGF method (SGF-ExpN). Numerical results are presented to illustrate the rational function approximation accuracy. (author)

Calculation of neutron importance function in fissionable assemblies using Monte Carlo method

International Nuclear Information System (INIS)

Feghhi, S. A. H.; Afarideh, H.; Shahriari, M.

2007-01-01

The purpose of the present work is to develop an efficient solution method to calculate neutron importance function in fissionable assemblies for all criticality conditions, using Monte Carlo Method. The neutron importance function has a well important role in perturbation theory and reactor dynamic calculations. Usually this function can be determined by calculating adjoint flux through out solving the Adjoint weighted transport equation with deterministic methods. However, in complex geometries these calculations are very difficult. In this article, considering the capabilities of MCNP code in solving problems with complex geometries and its closeness to physical concepts, a comprehensive method based on physical concept of neutron importance has been introduced for calculating neutron importance function in sub-critical, critical and supercritical conditions. For this means a computer program has been developed. The results of the method has been benchmarked with ANISN code calculations in 1 and 2 group modes for simple geometries and their correctness has been approved for all three criticality conditions. Ultimately, the efficiency of the method for complex geometries has been shown by calculation of neutron importance in MNSR research reactor

Formal Analysis of SET and NSL Protocols Using the Interpretation Functions-Based Method

Directory of Open Access Journals (Sweden)

Hanane Houmani

2012-01-01

Full Text Available Most applications in the Internet such as e-banking and e-commerce use the SET and the NSL protocols to protect the communication channel between the client and the server. Then, it is crucial to ensure that these protocols respect some security properties such as confidentiality, authentication, and integrity. In this paper, we analyze the SET and the NSL protocols with respect to the confidentiality (secrecy property. To perform this analysis, we use the interpretation functions-based method. The main idea behind the interpretation functions-based technique is to give sufficient conditions that allow to guarantee that a cryptographic protocol respects the secrecy property. The flexibility of the proposed conditions allows the verification of daily-life protocols such as SET and NSL. Also, this method could be used under different assumptions such as a variety of intruder abilities including algebraic properties of cryptographic primitives. The NSL protocol, for instance, is analyzed with and without the homomorphism property. We show also, using the SET protocol, the usefulness of this approach to correct weaknesses and problems discovered during the analysis.

The Reliasep method used for the functional modeling of complex systems

International Nuclear Information System (INIS)

Dubiez, P.; Gaufreteau, P.; Pitton, J.P.

1997-07-01

The RELIASEP R method and its support tool have been recommended to carry out the functional analysis of large systems within the framework of the design of new power units. Let us first recall the principles of the method based on the breakdown of functions into tree(s). These functions are characterised by their performance and constraints. Then the main modifications made under EDF requirement and in particular the 'viewpoints' analyses are presented. The knowledge obtained from the first studies carried out are discussed. (author)

The Reliasep method used for the functional modeling of complex systems

Energy Technology Data Exchange (ETDEWEB)

Dubiez, P.; Gaufreteau, P.; Pitton, J.P

1997-07-01

The RELIASEP{sup R} method and its support tool have been recommended to carry out the functional analysis of large systems within the framework of the design of new power units. Let us first recall the principles of the method based on the breakdown of functions into tree(s). These functions are characterised by their performance and constraints. Then the main modifications made under EDF requirement and in particular the `viewpoints` analyses are presented. The knowledge obtained from the first studies carried out are discussed. (author)

Methods for assessing the effects of dehydration on cognitive function.

Science.gov (United States)

Lieberman, Harris R

2012-11-01

Studying the effects of dehydration on cognitive function presents a variety of unique and difficult challenges to investigators. These challenges, which are addressed in this article, can be divided into three general categories: 1) choosing an appropriate method of generating a consistent level of dehydration; 2) determining and effectively employing appropriate and sensitive measures of cognitive state; and 3) adequately controlling the many confounding factors that interfere with assessment of cognitive function. The design and conduct of studies on the effects of dehydration on cognitive function should carefully consider various methodological issues, and investigators should carefully weigh the benefits and disadvantages of particular methods and procedures. © 2012 International Life Sciences Institute.

Comparison of different methods to include recycling in LCAs of aluminium cans and disposable polystyrene cups

NARCIS (Netherlands)

Harst-Wintraecken, van der Eugenie; Potting, José; Kroeze, Carolien

2016-01-01

Many methods have been reported and used to include recycling in life cycle assessments (LCAs). This paper evaluates six widely used methods: three substitution methods (i.e. substitution based on equal quality, a correction factor, and alternative material), allocation based on the number of

Application of Exp-function method for (2 + 1)-dimensional nonlinear evolution equations

International Nuclear Information System (INIS)

Bekir, Ahmet; Boz, Ahmet

2009-01-01

In this paper, the Exp-function method is used to construct solitary and soliton solutions of (2 + 1)-dimensional nonlinear evolution equations. (2 + 1)-dimensional breaking soliton (Calogero) equation, modified Zakharov-Kuznetsov and Konopelchenko-Dubrovsky equations are chosen to illustrate the effectiveness of the method. The method is straightforward and concise, and its applications are promising. The Exp-function method presents a wider applicability for handling nonlinear wave equations.

Cross-Correlation-Function-Based Multipath Mitigation Method for Sine-BOC Signals

Directory of Open Access Journals (Sweden)

H. H. Chen

2012-06-01

Full Text Available Global Navigation Satellite Systems (GNSS positioning accuracy indoor and urban canyons environments are greatly affected by multipath due to distortions in its autocorrelation function. In this paper, a cross-correlation function between the received sine phased Binary Offset Carrier (sine-BOC modulation signal and the local signal is studied firstly, and a new multipath mitigation method based on cross-correlation function for sine-BOC signal is proposed. This method is implemented to create a cross-correlation function by designing the modulated symbols of the local signal. The theoretical analysis and simulation results indicate that the proposed method exhibits better multipath mitigation performance compared with the traditional Double Delta Correlator (DDC techniques, especially the medium/long delay multipath signals, and it is also convenient and flexible to implement by using only one correlator, which is the case of low-cost mass-market receivers.

Apparatus and test method for characterizing the temperature regulating properties of thermal functional porous polymeric materials.

Science.gov (United States)

Yao, Bao-Guo; Zhang, Shan; Zhang, De-Pin

2017-05-01

In order to evaluate the temperature regulating properties of thermal functional porous polymeric materials such as fabrics treated with phase change material microcapsules, a new apparatus was developed. The apparatus and the test method can measure the heat flux, temperature, and displacement signals during the dynamic contact and then quickly give an evaluation for the temperature regulating properties by simulating the dynamic heat transfer and temperature regulating process when the materials contact the body skin. A series of indices including the psychosensory intensity, regulating capability index, and relative regulating index were defined to characterize the temperature regulating properties. The measurement principle, the evaluation criteria and grading method, the experimental setup and the test results discussion, and the gage capability analysis of the apparatus are presented. The new apparatus provides a method for the objective measurement and evaluation of the temperature regulating properties of thermal functional porous polymeric materials.

Application of the Exp-function method to the equal-width wave equation

International Nuclear Information System (INIS)

Biazar, J; Ayati, Z

2008-01-01

In this paper, the Exp-function method is used to find an exact solution of the equal-width wave (EW) equation. The method is straightforward and concise, and its applications are promising. It is shown that the Exp-function method, with the help of symbolic computation, provides a very effective and powerful mathematical tool for solving the EW equation.

Accuracy of three-body wave functions obtained with the correlation-function hyperspherical-harmonic method

International Nuclear Information System (INIS)

Haftel, M.I.; Mandelzweig, V.B.

1990-01-01

The local convergence and accuracy of wave functions obtained by direct solution of the Schroedinger equation with the help of the correlation-function hyperspherical-harmonic method are analyzed for ground and excited states of the helium atom and for the ground state of the positronium negative ion. The inclusion of the cusp conditions into the correlation function is shown to be of crucial importance, not only near the coalescence points, but also away from them. The proper inclusion of all cusps yields for the ground state of the helium atom the local wave-function accuracy of about 10 -7 for different interparticle distances. The omission of one of the cusps in the excited helium atom reduces the wave-function precision to 10 -2 near the corresponding coalescence point and to 10 -4 --10 -5 away from it

Optimized Signaling Method for High-Speed Transmission Channels with Higher Order Transfer Function

Science.gov (United States)

Ševčík, Břetislav; Brančík, Lubomír; Kubíček, Michal

2017-08-01

In this paper, the selected results from testing of optimized CMOS friendly signaling method for high-speed communications over cables and printed circuit boards (PCBs) are presented and discussed. The proposed signaling scheme uses modified concept of pulse width modulated (PWM) signal which enables to better equalize significant channel losses during data high-speed transmission. Thus, the very effective signaling method to overcome losses in transmission channels with higher order transfer function, typical for long cables and multilayer PCBs, is clearly analyzed in the time and frequency domain. Experimental results of the measurements include the performance comparison of conventional PWM scheme and clearly show the great potential of the modified signaling method for use in low power CMOS friendly equalization circuits, commonly considered in modern communication standards as PCI-Express, SATA or in Multi-gigabit SerDes interconnects.

Difficulties in applying pure Kohn-Sham density functional theory electronic structure methods to protein molecules

Science.gov (United States)

Rudberg, Elias

2012-02-01

Self-consistency-based Kohn-Sham density functional theory (KS-DFT) electronic structure calculations with Gaussian basis sets are reported for a set of 17 protein-like molecules with geometries obtained from the Protein Data Bank. It is found that in many cases such calculations do not converge due to vanishing HOMO-LUMO gaps. A sequence of polyproline I helix molecules is also studied and it is found that self-consistency calculations using pure functionals fail to converge for helices longer than six proline units. Since the computed gap is strongly correlated to the fraction of Hartree-Fock exchange, test calculations using both pure and hybrid density functionals are reported. The tested methods include the pure functionals BLYP, PBE and LDA, as well as Hartree-Fock and the hybrid functionals BHandHLYP, B3LYP and PBE0. The effect of including solvent molecules in the calculations is studied, and it is found that the inclusion of explicit solvent molecules around the protein fragment in many cases gives a larger gap, but that convergence problems due to vanishing gaps still occur in calculations with pure functionals. In order to achieve converged results, some modeling of the charge distribution of solvent water molecules outside the electronic structure calculation is needed. Representing solvent water molecules by a simple point charge distribution is found to give non-vanishing HOMO-LUMO gaps for the tested protein-like systems also for pure functionals.

Difficulties in applying pure Kohn-Sham density functional theory electronic structure methods to protein molecules

International Nuclear Information System (INIS)

Rudberg, Elias

2012-01-01

Self-consistency-based Kohn-Sham density functional theory (KS-DFT) electronic structure calculations with Gaussian basis sets are reported for a set of 17 protein-like molecules with geometries obtained from the Protein Data Bank. It is found that in many cases such calculations do not converge due to vanishing HOMO-LUMO gaps. A sequence of polyproline I helix molecules is also studied and it is found that self-consistency calculations using pure functionals fail to converge for helices longer than six proline units. Since the computed gap is strongly correlated to the fraction of Hartree-Fock exchange, test calculations using both pure and hybrid density functionals are reported. The tested methods include the pure functionals BLYP, PBE and LDA, as well as Hartree-Fock and the hybrid functionals BHandHLYP, B3LYP and PBE0. The effect of including solvent molecules in the calculations is studied, and it is found that the inclusion of explicit solvent molecules around the protein fragment in many cases gives a larger gap, but that convergence problems due to vanishing gaps still occur in calculations with pure functionals. In order to achieve converged results, some modeling of the charge distribution of solvent water molecules outside the electronic structure calculation is needed. Representing solvent water molecules by a simple point charge distribution is found to give non-vanishing HOMO-LUMO gaps for the tested protein-like systems also for pure functionals. (fast track communication)

Functional methods for arbitrary densities in curved spacetime

International Nuclear Information System (INIS)

Basler, M.

1993-01-01

This paper gives an introduction to the technique of functional differentiation and integration in curved spacetime, applied to examples from quantum field theory. Special attention is drawn on the choice of functional integral measure. Referring to a suggestion by Toms, fields are choosen as arbitrary scalar, spinorial or vectorial densities. The technique developed by Toms for a pure quadratic Lagrangian are extended to the calculation of the generating functional with external sources. Included are two examples of interacting theories, a self-interacting scalar field and a Yang-Mills theory. For these theories the complete set of Feynman graphs depending on the weight of variables is derived. (orig.)

Recent advances in radial basis function collocation methods

CERN Document Server

Chen, Wen; Chen, C S

2014-01-01

This book surveys the latest advances in radial basis function (RBF) meshless collocation methods which emphasis on recent novel kernel RBFs and new numerical schemes for solving partial differential equations. The RBF collocation methods are inherently free of integration and mesh, and avoid tedious mesh generation involved in standard finite element and boundary element methods. This book focuses primarily on the numerical algorithms, engineering applications, and highlights a large class of novel boundary-type RBF meshless collocation methods. These methods have shown a clear edge over the traditional numerical techniques especially for problems involving infinite domain, moving boundary, thin-walled structures, and inverse problems. Due to the rapid development in RBF meshless collocation methods, there is a need to summarize all these new materials so that they are available to scientists, engineers, and graduate students who are interest to apply these newly developed methods for solving real world’s ...

The non-equilibrium Green's function method for nanoscale device simulation

CERN Document Server

Pourfath, Mahdi

2014-01-01

For modeling the transport of carriers in nanoscale devices, a Green-function formalism is the most accurate approach. Due to the complexity of the formalism, one should have a deep understanding of the underlying principles and use smart approximations and numerical methods for solving the kinetic equations at a reasonable computational time. In this book the required concepts from quantum and statistical mechanics and numerical methods for calculating Green functions are presented. The Green function is studied in detail for systems both under equilibrium and under nonequilibrium conditions. Because the formalism enables rigorous modeling of different scattering mechanisms in terms of self-energies, but an exact evaluation of self-energies for realistic systems is not possible, their approximation and inclusion in the quantum kinetic equations of the Green functions are elaborated. All the elements of the kinetic equations, which are the device Hamiltonian, contact self-energies, and scattering self-energie...

A Statistical Method of Identifying Interactions in Neuron–Glia Systems Based on Functional Multicell Ca2+ Imaging

Science.gov (United States)

Nakae, Ken; Ikegaya, Yuji; Ishikawa, Tomoe; Oba, Shigeyuki; Urakubo, Hidetoshi; Koyama, Masanori; Ishii, Shin

2014-01-01

Crosstalk between neurons and glia may constitute a significant part of information processing in the brain. We present a novel method of statistically identifying interactions in a neuron–glia network. We attempted to identify neuron–glia interactions from neuronal and glial activities via maximum-a-posteriori (MAP)-based parameter estimation by developing a generalized linear model (GLM) of a neuron–glia network. The interactions in our interest included functional connectivity and response functions. We evaluated the cross-validated likelihood of GLMs that resulted from the addition or removal of connections to confirm the existence of specific neuron-to-glia or glia-to-neuron connections. We only accepted addition or removal when the modification improved the cross-validated likelihood. We applied the method to a high-throughput, multicellular in vitro Ca2+ imaging dataset obtained from the CA3 region of a rat hippocampus, and then evaluated the reliability of connectivity estimates using a statistical test based on a surrogate method. Our findings based on the estimated connectivity were in good agreement with currently available physiological knowledge, suggesting our method can elucidate undiscovered functions of neuron–glia systems. PMID:25393874

Multiscale finite element methods for high-contrast problems using local spectral basis functions

KAUST Repository

Efendiev, Yalchin

2011-02-01

In this paper we study multiscale finite element methods (MsFEMs) using spectral multiscale basis functions that are designed for high-contrast problems. Multiscale basis functions are constructed using eigenvectors of a carefully selected local spectral problem. This local spectral problem strongly depends on the choice of initial partition of unity functions. The resulting space enriches the initial multiscale space using eigenvectors of local spectral problem. The eigenvectors corresponding to small, asymptotically vanishing, eigenvalues detect important features of the solutions that are not captured by initial multiscale basis functions. Multiscale basis functions are constructed such that they span these eigenfunctions that correspond to small, asymptotically vanishing, eigenvalues. We present a convergence study that shows that the convergence rate (in energy norm) is proportional to (H/Λ*)1/2, where Λ* is proportional to the minimum of the eigenvalues that the corresponding eigenvectors are not included in the coarse space. Thus, we would like to reach to a larger eigenvalue with a smaller coarse space. This is accomplished with a careful choice of initial multiscale basis functions and the setup of the eigenvalue problems. Numerical results are presented to back-up our theoretical results and to show higher accuracy of MsFEMs with spectral multiscale basis functions. We also present a hierarchical construction of the eigenvectors that provides CPU savings. © 2010.

Fertilizer nitrogen prescription for cotton by 15N recovery method under integrated nutrient management using soil test crop response function

International Nuclear Information System (INIS)

Arulmozhiselvan, K.; Govindaswamy, M.; Chellamuthu, S.

2007-01-01

Fertilizer efficiency is a vital parameter in prescription functions to compute fertilizer requirements of crops for achieving a specific yield target. In Soil Test Crop Response (STCR) function, nitrogen fertilizer efficiency is calculated by Apparent N Recovery (ANR) method, which includes the effect of added N interaction (ANI) on soil N reserves. In order to exclude soil effect and refine STCR function, the real efficiency of fertilizer N was estimated by 15 N recovery method. By fitting 15 N recovery in the function, the fertilizer N required for a specific yield target of cotton was estimated. The estimated N requirement by 15 N recovery method was lesser than ANR method when available soil N relatively increased. The approach also fine-tuned the N contributing efficiency of soil, farmyard manure and Azospirillum under Integrated Nutrient Management (INM). For achieving 25 q of seed cotton yield in a soil having 220 kg of available N ha -1 , the predicted N requirement was 159 kg ha -1 under ANR method, whereas in 15 N recovery method fertilizer N to be applied was 138 kg ha -1 with urea alone and 79 kg ha -1 with urea + FYM + Azospirillum. (author)

Study on application of green's function method in thermal stress rapid calculation

International Nuclear Information System (INIS)

Zhang Guihe; Duan Yuangang; Xu Xiao; Chen Rong

2013-01-01

This paper presents a quick and accuracy thermal stress calculation method, the Green's Function Method, which is a combination of finite element method and numerical algorithm method. Thermal stress calculation of Safe Injection Nozzle of Reactor Coolant Line of PWR plant is performed with Green's function method for heatup and cooldown thermal transients as a demonstration example, and the result is compared with finite element method to verify the rationality and accuracy of this method. The advantage and disadvantage of the Green's function method and the finite element method are also compared. (authors)

New application of Exp-function method for improved Boussinesq equation

Energy Technology Data Exchange (ETDEWEB)

Abdou, M.A. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Department of Physics, Faculty of Education for Girls, Science Departments, King Khalid University, Bisha (Saudi Arabia)], E-mail: m_abdou_eg@yahoo.com; Soliman, A.A. [Department of Mathematics, Faculty of Education (AL-Arish) Suez Canal University, AL-Arish 45111 (Egypt); Department of Mathematics, Teacher' s College (Bisha), King Khalid University, Bisha, PO Box 551 (Saudi Arabia)], E-mail: asoliman_99@yahoo.com; El-Basyony, S.T. [Theoretical Research Group, Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt)

2007-10-01

The Exp-function method is used to obtain generalized solitary solutions and periodic solutions for nonlinear evolution equations arising in mathematical physics with the aid of symbolic computation method, namely, the improved Boussinesq equation. The method is straightforward and concise, and its applications is promising for other nonlinear evolution equations in mathematical physics.

Approximation of the exponential integral (well function) using sampling methods

Science.gov (United States)

Baalousha, Husam Musa

2015-04-01

Exponential integral (also known as well function) is often used in hydrogeology to solve Theis and Hantush equations. Many methods have been developed to approximate the exponential integral. Most of these methods are based on numerical approximations and are valid for a certain range of the argument value. This paper presents a new approach to approximate the exponential integral. The new approach is based on sampling methods. Three different sampling methods; Latin Hypercube Sampling (LHS), Orthogonal Array (OA), and Orthogonal Array-based Latin Hypercube (OA-LH) have been used to approximate the function. Different argument values, covering a wide range, have been used. The results of sampling methods were compared with results obtained by Mathematica software, which was used as a benchmark. All three sampling methods converge to the result obtained by Mathematica, at different rates. It was found that the orthogonal array (OA) method has the fastest convergence rate compared with LHS and OA-LH. The root mean square error RMSE of OA was in the order of 1E-08. This method can be used with any argument value, and can be used to solve other integrals in hydrogeology such as the leaky aquifer integral.

Lung function imaging methods in Cystic Fibrosis pulmonary disease.

Science.gov (United States)

Kołodziej, Magdalena; de Veer, Michael J; Cholewa, Marian; Egan, Gary F; Thompson, Bruce R

2017-05-17

Monitoring of pulmonary physiology is fundamental to the clinical management of patients with Cystic Fibrosis. The current standard clinical practise uses spirometry to assess lung function which delivers a clinically relevant functional readout of total lung function, however does not supply any visible or localised information. High Resolution Computed Tomography (HRCT) is a well-established current 'gold standard' method for monitoring lung anatomical changes in Cystic Fibrosis patients. HRCT provides excellent morphological information, however, the X-ray radiation dose can become significant if multiple scans are required to monitor chronic diseases such as cystic fibrosis. X-ray phase-contrast imaging is another emerging X-ray based methodology for Cystic Fibrosis lung assessment which provides dynamic morphological and functional information, albeit with even higher X-ray doses than HRCT. Magnetic Resonance Imaging (MRI) is a non-ionising radiation imaging method that is garnering growing interest among researchers and clinicians working with Cystic Fibrosis patients. Recent advances in MRI have opened up the possibilities to observe lung function in real time to potentially allow sensitive and accurate assessment of disease progression. The use of hyperpolarized gas or non-contrast enhanced MRI can be tailored to clinical needs. While MRI offers significant promise it still suffers from poor spatial resolution and the development of an objective scoring system especially for ventilation assessment.

Coupled double-distribution-function lattice Boltzmann method for the compressible Navier-Stokes equations.

Science.gov (United States)

Li, Q; He, Y L; Wang, Y; Tao, W Q

2007-11-01

A coupled double-distribution-function lattice Boltzmann method is developed for the compressible Navier-Stokes equations. Different from existing thermal lattice Boltzmann methods, this method can recover the compressible Navier-Stokes equations with a flexible specific-heat ratio and Prandtl number. In the method, a density distribution function based on a multispeed lattice is used to recover the compressible continuity and momentum equations, while the compressible energy equation is recovered by an energy distribution function. The energy distribution function is then coupled to the density distribution function via the thermal equation of state. In order to obtain an adjustable specific-heat ratio, a constant related to the specific-heat ratio is introduced into the equilibrium energy distribution function. Two different coupled double-distribution-function lattice Boltzmann models are also proposed in the paper. Numerical simulations are performed for the Riemann problem, the double-Mach-reflection problem, and the Couette flow with a range of specific-heat ratios and Prandtl numbers. The numerical results are found to be in excellent agreement with analytical and/or other solutions.

Platelet function testing: methods of assessment and clinical utility.

LENUS (Irish Health Repository)

Mylotte, Darren

2012-02-01

Platelets play a central role in the regulation of both thrombosis and haemostasis yet tests of platelet function have, until recently, been exclusively used in the diagnosis and management of bleeding disorders. Recent advances have demonstrated the clinical utility of platelet function testing in patients with cardiovascular disease. The ex vivo measurement of response to antiplatelet therapies (aspirin and clopidogrel), by an ever-increasing array of platelet function tests, is with some assays, predictive of adverse clinical events and thus, represents an emerging area of interest for both the clinician and basic scientist. This review article will describe the advantages and disadvantages of the currently available methods of measuring platelet function and discuss both the limitations and emerging data supporting the role of platelet function studies in clinical practice.

Platelet function testing: methods of assessment and clinical utility.

LENUS (Irish Health Repository)

Mylotte, Darren

2011-01-01

Platelets play a central role in the regulation of both thrombosis and haemostasis yet tests of platelet function have, until recently, been exclusively used in the diagnosis and management of bleeding disorders. Recent advances have demonstrated the clinical utility of platelet function testing in patients with cardiovascular disease. The ex vivo measurement of response to antiplatelet therapies (aspirin and clopidogrel), by an ever-increasing array of platelet function tests, is with some assays, predictive of adverse clinical events and thus, represents an emerging area of interest for both the clinician and basic scientist. This review article will describe the advantages and disadvantages of the currently available methods of measuring platelet function and discuss both the limitations and emerging data supporting the role of platelet function studies in clinical practice.

A method for the computation of turbulent polymeric liquids including hydrodynamic interactions and chain entanglements

Energy Technology Data Exchange (ETDEWEB)

Kivotides, Demosthenes, E-mail: demosthenes.kivotides@strath.ac.uk

2017-02-12

An asymptotically exact method for the direct computation of turbulent polymeric liquids that includes (a) fully resolved, creeping microflow fields due to hydrodynamic interactions between chains, (b) exact account of (subfilter) residual stresses, (c) polymer Brownian motion, and (d) direct calculation of chain entanglements, is formulated. Although developed in the context of polymeric fluids, the method is equally applicable to turbulent colloidal dispersions and aerosols. - Highlights: • An asymptotically exact method for the computation of polymer and colloidal fluids is developed. • The method is valid for all flow inertia and all polymer volume fractions. • The method models entanglements and hydrodynamic interactions between polymer chains.

Development of calculation method for one-dimensional kinetic analysis in fission reactors, including feedback effects

International Nuclear Information System (INIS)

Paixao, S.B.; Marzo, M.A.S.; Alvim, A.C.M.

1986-01-01

The calculation method used in WIGLE code is studied. Because of the non availability of such a praiseworthy solution, expounding the method minutely has been tried. This developed method has been applied for the solution of the one-dimensional, two-group, diffusion equations in slab, axial analysis, including non-boiling heat transfer, accountig for feedback. A steady-state program (CITER-1D), written in FORTRAN 4, has been implemented, providing excellent results, ratifying the developed work quality. (Author) [pt

Application of the Characteristic Basis Function Method Using CUDA

Directory of Open Access Journals (Sweden)

Juan Ignacio Pérez

2014-01-01

Full Text Available The characteristic basis function method (CBFM is a popular technique for efficiently solving the method of moments (MoM matrix equations. In this work, we address the adaptation of this method to a relatively new computing infrastructure provided by NVIDIA, the Compute Unified Device Architecture (CUDA, and take into account some of the limitations which appear when the geometry under analysis becomes too big to fit into the Graphics Processing Unit’s (GPU’s memory.

Local-scaling density-functional method: Intraorbit and interorbit density optimizations

International Nuclear Information System (INIS)

Koga, T.; Yamamoto, Y.; Ludena, E.V.

1991-01-01

The recently proposed local-scaling density-functional theory provides us with a practical method for the direct variational determination of the electron density function ρ(r). The structure of ''orbits,'' which ensures the one-to-one correspondence between the electron density ρ(r) and the N-electron wave function Ψ({r k }), is studied in detail. For the realization of the local-scaling density-functional calculations, procedures for intraorbit and interorbit optimizations of the electron density function are proposed. These procedures are numerically illustrated for the helium atom in its ground state at the beyond-Hartree-Fock level

FUN-LDA: A Latent Dirichlet Allocation Model for Predicting Tissue-Specific Functional Effects of Noncoding Variation: Methods and Applications.

Science.gov (United States)

Backenroth, Daniel; He, Zihuai; Kiryluk, Krzysztof; Boeva, Valentina; Pethukova, Lynn; Khurana, Ekta; Christiano, Angela; Buxbaum, Joseph D; Ionita-Laza, Iuliana

2018-05-03

We describe a method based on a latent Dirichlet allocation model for predicting functional effects of noncoding genetic variants in a cell-type- and/or tissue-specific way (FUN-LDA). Using this unsupervised approach, we predict tissue-specific functional effects for every position in the human genome in 127 different tissues and cell types. We demonstrate the usefulness of our predictions by using several validation experiments. Using eQTL data from several sources, including the GTEx project, Geuvadis project, and TwinsUK cohort, we show that eQTLs in specific tissues tend to be most enriched among the predicted functional variants in relevant tissues in Roadmap. We further show how these integrated functional scores can be used for (1) deriving the most likely cell or tissue type causally implicated for a complex trait by using summary statistics from genome-wide association studies and (2) estimating a tissue-based correlation matrix of various complex traits. We found large enrichment of heritability in functional components of relevant tissues for various complex traits, and FUN-LDA yielded higher enrichment estimates than existing methods. Finally, using experimentally validated functional variants from the literature and variants possibly implicated in disease by previous studies, we rigorously compare FUN-LDA with state-of-the-art functional annotation methods and show that FUN-LDA has better prediction accuracy and higher resolution than these methods. In particular, our results suggest that tissue- and cell-type-specific functional prediction methods tend to have substantially better prediction accuracy than organism-level prediction methods. Scores for each position in the human genome and for each ENCODE and Roadmap tissue are available online (see Web Resources). Copyright © 2018 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Computational Methods for Large Spatio-temporal Datasets and Functional Data Ranking

KAUST Repository

Huang, Huang

2017-07-16

This thesis focuses on two topics, computational methods for large spatial datasets and functional data ranking. Both are tackling the challenges of big and high-dimensional data. The first topic is motivated by the prohibitive computational burden in fitting Gaussian process models to large and irregularly spaced spatial datasets. Various approximation methods have been introduced to reduce the computational cost, but many rely on unrealistic assumptions about the process and retaining statistical efficiency remains an issue. We propose a new scheme to approximate the maximum likelihood estimator and the kriging predictor when the exact computation is infeasible. The proposed method provides different types of hierarchical low-rank approximations that are both computationally and statistically efficient. We explore the improvement of the approximation theoretically and investigate the performance by simulations. For real applications, we analyze a soil moisture dataset with 2 million measurements with the hierarchical low-rank approximation and apply the proposed fast kriging to fill gaps for satellite images. The second topic is motivated by rank-based outlier detection methods for functional data. Compared to magnitude outliers, it is more challenging to detect shape outliers as they are often masked among samples. We develop a new notion of functional data depth by taking the integration of a univariate depth function. Having a form of the integrated depth, it shares many desirable features. Furthermore, the novel formation leads to a useful decomposition for detecting both shape and magnitude outliers. Our simulation studies show the proposed outlier detection procedure outperforms competitors in various outlier models. We also illustrate our methodology using real datasets of curves, images, and video frames. Finally, we introduce the functional data ranking technique to spatio-temporal statistics for visualizing and assessing covariance properties, such as

[Functional results of cryosurgical procedures in rhegmatogenous retinal detachment including macula region - our experience].

Science.gov (United States)

Chrapek, O; Sín, M; Jirková, B; Jarkovský, J; Rehák, J

2013-10-01

Aim of this study is to evaluate retrospectively functional results of cryosurgical treatment of uncomplicated, idiopathic rhegmatogenous retinal detachment including macula region in phakic patients operated on at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc, Czech Republic, E.U., during the period 2002 -2013, and to evaluate the significance of the macula detachment duration for the final visual acuity. In the study group were included 56 eyes of 56 patients operated in the years 2003 - 2012 at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc. All patients were phakic and in all of them, the retinal detachment including the macula region was diagnosed. The mean follow-up period of the patients was 8,75 months. The initial and final visual acuity testing were performed. Comparing the initial and final visual acuity we rated the level of the visual acuity change. The result was stated as improved, if the visual acuity improved by 1 or more lines on the ETDRS chart. The result was rated as stabilized, if the visual acuity remained the same or it changed by 1 line of the ETDRS chart only. The result was evaluated as worsened, if the visual acuity decreased by 1 or more lines of the ETDRS chart. In the followed-up group, the authors compared visual acuity levels in patients with the macula detachment duration 10 days and 11 days. For the statistical evaluation of achieved results, the Mann - Whitney U test was used. The visual acuity improved in 49 (87 %), did not changed in 5 (9 %) and worsened in 2 (4 %) patients. The patients with macula detachment duration 10 days achieved statistically significant better visual acuity than patients with macula detachment duration 11 days. Patients with macula detachment duration 10 days have better prognosis for functional result than patients with macula detachment duration 11 days.

The continuous, desingularized Newton method for meromorphic functions

NARCIS (Netherlands)

Jongen, H.Th.; Jonker, P.; Twilt, F.

For any (nonconstant) meromorphic function, we present a real analytic dynamical system, which may be interpreted as an infinitesimal version of Newton's method for finding its zeros. A fairly complete description of the local and global features of the phase portrait of such a system is obtained

Method of making gold thiolate and photochemically functionalized microcantilevers

Science.gov (United States)

Boiadjiev, Vassil I [Knoxville, TN; Brown, Gilbert M [Knoxville, TN; Pinnaduwage, Lal A [Knoxville, TN; Thundat, Thomas G [Knoxville, TN; Bonnesen, Peter V [Knoxville, TN; Goretzki, Gudrun [Nottingham, GB

2009-08-25

Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process. By focusing the activating UV light sequentially on selected silicon or silicon nitride hydrogen terminated surfaces and soaking or spotting selected metallic surfaces with organic thiols, sulfides, or disulfides, the microcantilevers are functionalized. The device and photochemical method are intended to be integrated into systems for detecting specific agents including chromate groundwater contamination, gasoline, and biological species.

Exp-function method for solving fractional partial differential equations.

Science.gov (United States)

Zheng, Bin

2013-01-01

We extend the Exp-function method to fractional partial differential equations in the sense of modified Riemann-Liouville derivative based on nonlinear fractional complex transformation. For illustrating the validity of this method, we apply it to the space-time fractional Fokas equation and the nonlinear fractional Sharma-Tasso-Olver (STO) equation. As a result, some new exact solutions for them are successfully established.

A meshless local radial basis function method for two-dimensional incompressible Navier-Stokes equations

KAUST Repository

Wang, Zhiheng

2014-12-10

A meshless local radial basis function method is developed for two-dimensional incompressible Navier-Stokes equations. The distributed nodes used to store the variables are obtained by the philosophy of an unstructured mesh, which results in two main advantages of the method. One is that the unstructured nodes generation in the computational domain is quite simple, without much concern about the mesh quality; the other is that the localization of the obtained collocations for the discretization of equations is performed conveniently with the supporting nodes. The algebraic system is solved by a semi-implicit pseudo-time method, in which the convective and source terms are explicitly marched by the Runge-Kutta method, and the diffusive terms are implicitly solved. The proposed method is validated by several benchmark problems, including natural convection in a square cavity, the lid-driven cavity flow, and the natural convection in a square cavity containing a circular cylinder, and very good agreement with the existing results are obtained.

Application of Patterson-function direct methods to materials characterization.

Science.gov (United States)

Rius, Jordi

2014-09-01

The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM), from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data.

Application of Patterson-function direct methods to materials characterization

Directory of Open Access Journals (Sweden)

Jordi Rius

2014-09-01

Full Text Available The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM, from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data.

Frames and other bases in abstract and function spaces novel methods in harmonic analysis

CERN Document Server

Gia, Quoc; Mayeli, Azita; Mhaskar, Hrushikesh; Zhou, Ding-Xuan

2017-01-01

The first of a two volume set on novel methods in harmonic analysis, this book draws on a number of original research and survey papers from well-known specialists detailing the latest innovations and recently discovered links between various fields. Along with many deep theoretical results, these volumes contain numerous applications to problems in signal processing, medical imaging, geodesy, statistics, and data science. The chapters within cover an impressive range of ideas from both traditional and modern harmonic analysis, such as: the Fourier transform, Shannon sampling, frames, wavelets, functions on Euclidean spaces, analysis on function spaces of Riemannian and sub-Riemannian manifolds, Fourier analysis on manifolds and Lie groups, analysis on combinatorial graphs, sheaves, co-sheaves, and persistent homologies on topological spaces. Volume I is organized around the theme of frames and other bases in abstract and function spaces, covering topics such as: The advanced development of frames, including ...

Dual number algebra method for Green's function derivatives in 3D magneto-electro-elasticity

Science.gov (United States)

Dziatkiewicz, Grzegorz

2018-01-01

The Green functions are the basic elements of the boundary element method. To obtain the boundary integral formulation the Green function and its derivative should be known for the considered differential operator. Today the interesting group of materials are electronic composites. The special case of the electronic composite is the magnetoelectroelastic continuum. The mentioned continuum is a model of the piezoelectric-piezomagnetic composites. The anisotropy of their physical properties makes the problem of Green's function determination very difficult. For that reason Green's functions for the magnetoelectroelastic continuum are not known in the closed form and numerical methods should be applied to determine such Green's functions. These means that the problem of the accurate and simply determination of Green's function derivatives is even harder. Therefore in the present work the dual number algebra method is applied to calculate numerically the derivatives of 3D Green's functions for the magnetoelectroelastic materials. The introduced method is independent on the step size and it can be treated as a special case of the automatic differentiation method. Therefore, the dual number algebra method can be applied as a tool for checking the accuracy of the well-known finite difference schemes.

Development of Manufacturing Method of Highly Functional Material Gallic acid-CLA Ester Using Irradiation

International Nuclear Information System (INIS)

Cho, C. H.; Byun, M. W.; Jeong, I. Y.; Kim, D. H.

2006-01-01

Increasing interest and current trends for natural materials with various health beneficial functions by radiation (RT)-biotechnology (BT) fusion by developed countries. However, the information and development of new functional materials using the RT-BT fusion technology is still limited. The target material developed and manufactured by RT-BT fusion technology may have a multi-functional effect on human health and it can be applied for pharmaceutical materials as well as functional food ingredient. The market of functional new materials has been grown dramatically and a multi-functional material manufactured by RT-BT fusion technology may have a great economic impact for both the domestic and overseas market. Development of GA-CLA ester by chemical synthetic method. Transformation of linoleic acid to conjugated linoleic acid by irradiation. Identification and confirmation of the biological functions including antioxidative, cancer cell proliferation inhibition, anti-microbial, enhancement of immune response and lipid metabolism of GA-CLA ester. Increase industrial applicability of the new materials. Development of GA-CLA ester by chemical synthetic method(2 patents submitted). Development of the optimum methodology of GA-CLA and its derivative, octadeca-9,12-dienyl-3,4,5-trihydroxy benzoate). Identification and confirmation of biological activities of GA-CLA. Extramural funding from the Ministry of Commerce, Industry, and Energy subjected by gallic acid-fatty acid derivatives (205,000,000 Won). Provides the basic data for successful project 'Development of cosmeceutical and cosmetics using gallic acid fatty acid derivatives' funded by Ministry of Commerce, Industry, and Energy and collaboration with the Technology-invested venture company, SunBiotech, Co. and problem-solving for industrial application. Complete the patent procedure and publish the results to international or domestic peer-reviewed journals

An efficient method for hybrid density functional calculation with spin-orbit coupling

Science.gov (United States)

Wang, Maoyuan; Liu, Gui-Bin; Guo, Hong; Yao, Yugui

2018-03-01

In first-principles calculations, hybrid functional is often used to improve accuracy from local exchange correlation functionals. A drawback is that evaluating the hybrid functional needs significantly more computing effort. When spin-orbit coupling (SOC) is taken into account, the non-collinear spin structure increases computing effort by at least eight times. As a result, hybrid functional calculations with SOC are intractable in most cases. In this paper, we present an approximate solution to this problem by developing an efficient method based on a mixed linear combination of atomic orbital (LCAO) scheme. We demonstrate the power of this method using several examples and we show that the results compare very well with those of direct hybrid functional calculations with SOC, yet the method only requires a computing effort similar to that without SOC. The presented technique provides a good balance between computing efficiency and accuracy, and it can be extended to magnetic materials.

Linear density response function in the projector augmented wave method

DEFF Research Database (Denmark)

Yan, Jun; Mortensen, Jens Jørgen; Jacobsen, Karsten Wedel

2011-01-01

We present an implementation of the linear density response function within the projector-augmented wave method with applications to the linear optical and dielectric properties of both solids, surfaces, and interfaces. The response function is represented in plane waves while the single...... functions of Si, C, SiC, AlP, and GaAs compare well with previous calculations. While optical properties of semiconductors, in particular excitonic effects, are generally not well described by ALDA, we obtain excellent agreement with experiments for the surface loss function of graphene and the Mg(0001...

Stream function method for computing steady rotational transonic flows with application to solar wind-type problems

International Nuclear Information System (INIS)

Kopriva, D.A.

1982-01-01

A numerical scheme has been developed to solve the quasilinear form of the transonic stream function equation. The method is applied to compute steady two-dimensional axisymmetric solar wind-type problems. A single, perfect, non-dissipative, homentropic and polytropic gas-dynamics is assumed. The four equations governing mass and momentum conservation are reduced to a single nonlinear second order partial differential equation for the stream function. Bernoulli's equation is used to obtain a nonlinear algebraic relation for the density in terms of stream function derivatives. The vorticity includes the effects of azimuthal rotation and Bernoulli's function and is determined from quantities specified on boundaries. The approach is efficient. The number of equations and independent variables has been reduced and a rapid relaxation technique developed for the transonic full potential equation is used. Second order accurate central differences are used in elliptic regions. In hyperbolic regions a dissipation term motivated by the rotated differencing scheme of Jameson is added for stability. A successive-line-overrelaxation technique also introduced by Jameson is used to solve the equations. The nonlinear equation for the density is a double valued function of the stream function derivatives. The velocities are extrapolated from upwind points to determine the proper branch and Newton's method is used to iteratively compute the density. This allows accurate solutions with few grid points

A method for improving global pyranometer measurements by modeling responsivity functions

Energy Technology Data Exchange (ETDEWEB)

Lester, A. [Smith College, Northampton, MA 01063 (United States); Myers, D.R. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401 (United States)

2006-03-15

Accurate global solar radiation measurements are crucial to climate change research and the development of solar energy technologies. Pyranometers produce an electrical signal proportional to global irradiance. The signal-to-irradiance ratio is the responsivity (RS) of the instrument (RS=signal/irradiance=microvolts/(W/m{sup 2})). Most engineering measurements are made using a constant RS. It is known that RS varies with day of year, zenith angle, and net infrared radiation. This study proposes a method to find an RS function to model a pyranometer's changing RS. Using a reference irradiance calculated from direct and diffuse instruments, we found instantaneous RS for two global pyranometers over 31 sunny days in a two-year period. We performed successive independent regressions of the error between the constant and instantaneous RS with respect to zenith angle, day of year, and net infrared to obtain an RS function. An alternative method replaced the infrared regression with an independently developed technique to account for thermal offset. Results show improved uncertainties with the function method than with the single-calibration value. Lower uncertainties also occur using a black-and-white (8-48), rather than all-black (PSP), shaded pyranometer as the diffuse reference instrument. We conclude that the function method is extremely effective in reducing uncertainty in the irradiance measurements for global PSP pyranometers if they are calibrated at the deployment site. Furthermore, it was found that the function method accounts for the pyranometer's thermal offset, rendering further corrections unnecessary. The improvements in irradiance data achieved in this study will serve to increase the accuracy of solar energy assessments and atmospheric research. (author)

Complete Tangent Stiffness for eXtended Finite Element Method by including crack growth parameters

DEFF Research Database (Denmark)

Mougaard, J.F.; Poulsen, P.N.; Nielsen, L.O.

2013-01-01

the crack geometry parameters, such as the crack length and the crack direction directly in the virtual work formulation. For efficiency, it is essential to obtain a complete tangent stiffness. A new method in this work is presented to include an incremental form the crack growth parameters on equal terms......The eXtended Finite Element Method (XFEM) is a useful tool for modeling the growth of discrete cracks in structures made of concrete and other quasi‐brittle and brittle materials. However, in a standard application of XFEM, the tangent stiffness is not complete. This is a result of not including...... with the degrees of freedom in the FEM‐equations. The complete tangential stiffness matrix is based on the virtual work together with the constitutive conditions at the crack tip. Introducing the crack growth parameters as direct unknowns, both equilibrium equations and the crack tip criterion can be handled...

On functions defined by sums of products of Bessel functions

International Nuclear Information System (INIS)

Martin, P A

2008-01-01

Various functions, defined as infinite series of products of Bessel functions of the first kind, are studied. Integral representations are obtained, and then used to deduce asymptotic approximations. Although several methods have been investigated (including power series expansions and integral transforms), methods based on Fourier series emerge as the most useful

Optimage central organised image quality control including statistics and reporting

International Nuclear Information System (INIS)

Jahnen, A.; Schilz, C.; Shannoun, F.; Schreiner, A.; Hermen, J.; Moll, C.

2008-01-01

Quality control of medical imaging systems is performed using dedicated phantoms. As the imaging systems are more and more digital, adequate image processing methods might help to save evaluation time and to receive objective results. The developed software package OPTIMAGE is focusing on this with a central approach: On one hand, OPTIMAGE provides a framework, which includes functions like database integration, DICOM data sources, multilingual user interface and image processing functionality. On the other hand, the test methods are implemented using modules which are able to process the images automatically for the common imaging systems. The integration of statistics and reporting into this environment is paramount: This is the only way to provide these functions in an interactive, user-friendly way. These features enable the users to discover degradation in performance quickly and document performed measurements easily. (authors)

Calculation of neutron importance function in fissionable assemblies using Monte Carlo method

International Nuclear Information System (INIS)

Feghhi, S.A.H.; Shahriari, M.; Afarideh, H.

2007-01-01

The purpose of the present work is to develop an efficient solution method for the calculation of neutron importance function in fissionable assemblies for all criticality conditions, based on Monte Carlo calculations. The neutron importance function has an important role in perturbation theory and reactor dynamic calculations. Usually this function can be determined by calculating the adjoint flux while solving the adjoint weighted transport equation based on deterministic methods. However, in complex geometries these calculations are very complicated. In this article, considering the capabilities of MCNP code in solving problems with complex geometries and its closeness to physical concepts, a comprehensive method based on the physical concept of neutron importance has been introduced for calculating the neutron importance function in sub-critical, critical and super-critical conditions. For this propose a computer program has been developed. The results of the method have been benchmarked with ANISN code calculations in 1 and 2 group modes for simple geometries. The correctness of these results has been confirmed for all three criticality conditions. Finally, the efficiency of the method for complex geometries has been shown by the calculation of neutron importance in Miniature Neutron Source Reactor (MNSR) research reactor

Fractional Complex Transform and exp-Function Methods for Fractional Differential Equations

Directory of Open Access Journals (Sweden)

Ahmet Bekir

2013-01-01

Full Text Available The exp-function method is presented for finding the exact solutions of nonlinear fractional equations. New solutions are constructed in fractional complex transform to convert fractional differential equations into ordinary differential equations. The fractional derivatives are described in Jumarie's modified Riemann-Liouville sense. We apply the exp-function method to both the nonlinear time and space fractional differential equations. As a result, some new exact solutions for them are successfully established.

Method for assessment of stormwater treatment facilities - Synthetic road runoff addition including micro-pollutants and tracer.

Science.gov (United States)

Cederkvist, Karin; Jensen, Marina B; Holm, Peter E

2017-08-01

Stormwater treatment facilities (STFs) are becoming increasingly widespread but knowledge on their performance is limited. This is due to difficulties in obtaining representative samples during storm events and documenting removal of the broad range of contaminants found in stormwater runoff. This paper presents a method to evaluate STFs by addition of synthetic runoff with representative concentrations of contaminant species, including the use of tracer for correction of removal rates for losses not caused by the STF. A list of organic and inorganic contaminant species, including trace elements representative of runoff from roads is suggested, as well as relevant concentration ranges. The method was used for adding contaminants to three different STFs including a curbstone extension with filter soil, a dual porosity filter, and six different permeable pavements. Evaluation of the method showed that it is possible to add a well-defined mixture of contaminants despite different field conditions by having a flexibly system, mixing different stock-solutions on site, and use bromide tracer for correction of outlet concentrations. Bromide recovery ranged from only 12% in one of the permeable pavements to 97% in the dual porosity filter, stressing the importance of including a conservative tracer for correction of contaminant retention values. The method is considered useful in future treatment performance testing of STFs. The observed performance of the STFs is presented in coming papers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Numerical simulation of electromagnetic waves in Schwarzschild space-time by finite difference time domain method and Green function method

Science.gov (United States)

Jia, Shouqing; La, Dongsheng; Ma, Xuelian

2018-04-01

The finite difference time domain (FDTD) algorithm and Green function algorithm are implemented into the numerical simulation of electromagnetic waves in Schwarzschild space-time. FDTD method in curved space-time is developed by filling the flat space-time with an equivalent medium. Green function in curved space-time is obtained by solving transport equations. Simulation results validate both the FDTD code and Green function code. The methods developed in this paper offer a tool to solve electromagnetic scattering problems.

Defining functioning levels in patients with schizophrenia: A combination of a novel clustering method and brain SPECT analysis.

Science.gov (United States)

Catherine, Faget-Agius; Aurélie, Vincenti; Eric, Guedj; Pierre, Michel; Raphaëlle, Richieri; Marine, Alessandrini; Pascal, Auquier; Christophe, Lançon; Laurent, Boyer

2017-12-30

This study aims to define functioning levels of patients with schizophrenia by using a method of interpretable clustering based on a specific functioning scale, the Functional Remission Of General Schizophrenia (FROGS) scale, and to test their validity regarding clinical and neuroimaging characterization. In this observational study, patients with schizophrenia have been classified using a hierarchical top-down method called clustering using unsupervised binary trees (CUBT). Socio-demographic, clinical, and neuroimaging SPECT perfusion data were compared between the different clusters to ensure their clinical relevance. A total of 242 patients were analyzed. A four-group functioning level structure has been identified: 54 are classified as "minimal", 81 as "low", 64 as "moderate", and 43 as "high". The clustering shows satisfactory statistical properties, including reproducibility and discriminancy. The 4 clusters consistently differentiate patients. "High" functioning level patients reported significantly the lowest scores on the PANSS and the CDSS, and the highest scores on the GAF, the MARS and S-QoL 18. Functioning levels were significantly associated with cerebral perfusion of two relevant areas: the left inferior parietal cortex and the anterior cingulate. Our study provides relevant functioning levels in schizophrenia, and may enhance the use of functioning scale. Copyright © 2017 Elsevier B.V. All rights reserved.

Diversity and functional traits of culturable microbiome members, including cyanobacteria in the rice phyllosphere.

Science.gov (United States)

Venkatachalam, S; Ranjan, K; Prasanna, R; Ramakrishnan, B; Thapa, S; Kanchan, A

2016-07-01

The diversity and abundance of culturable microbiome members of the rice phyllosphere was investigated using cv. Pusa Punjab Basmati 1509. Both diversity and species richness of bacteria were significantly higher in plants in pots in a semi-controlled environment than those in fields. Application of fertilisers reduced both diversity and species richness in field-grown plants under a conventional flooded system of rice intensification (SRI) and in dry-seeded rice (DSR) modes. Sequence analyses of 16S rDNA of culturable bacteria, those selected after amplified ribosomal DNA restriction analysis (ARDRA), showed the dominance of α-proteobacteria (35%) and actinobacteria (38%); Pantoea, Exiguobacterium and Bacillus were common among the culturable phyllospheric bacteria. About 34% of 83 culturable bacterial isolates had higher potential (>2 μg·ml(-1) ) for indole acetic acid production in the absence of tryptophan. Interestingly, the phyllosphere bacterial isolates from the pot experiment had significantly higher potential for nitrogen fixation than isolates from the field experiment. Enrichment for cyanobacteria showed both unicellular forms and non-heterocystous filaments under aerobic as well as anaerobic conditions. PCR-DGGE analysis of these showed that aerobic and anaerobic conditions as well as the three modes of cultivation of rice in the field strongly influenced the number and abundance of phylotypes. The adaptability and functional traits of these culturable microbiome members suggest enormous diversity in the phyllosphere, including potential for plant growth promotion, which was also significantly influenced by the different methods of growing rice. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Systems and methods for interpolation-based dynamic programming

KAUST Repository

Rockwood, Alyn

2013-01-03

Embodiments of systems and methods for interpolation-based dynamic programming. In one embodiment, the method includes receiving an object function and a set of constraints associated with the objective function. The method may also include identifying a solution on the objective function corresponding to intersections of the constraints. Additionally, the method may include generating an interpolated surface that is in constant contact with the solution. The method may also include generating a vector field in response to the interpolated surface.

Systems and methods for interpolation-based dynamic programming

KAUST Repository

Rockwood, Alyn

2013-01-01

Embodiments of systems and methods for interpolation-based dynamic programming. In one embodiment, the method includes receiving an object function and a set of constraints associated with the objective function. The method may also include identifying a solution on the objective function corresponding to intersections of the constraints. Additionally, the method may include generating an interpolated surface that is in constant contact with the solution. The method may also include generating a vector field in response to the interpolated surface.

Conjugate-gradient optimization method for orbital-free density functional calculations.

Science.gov (United States)

Jiang, Hong; Yang, Weitao

2004-08-01

Orbital-free density functional theory as an extension of traditional Thomas-Fermi theory has attracted a lot of interest in the past decade because of developments in both more accurate kinetic energy functionals and highly efficient numerical methodology. In this paper, we developed a conjugate-gradient method for the numerical solution of spin-dependent extended Thomas-Fermi equation by incorporating techniques previously used in Kohn-Sham calculations. The key ingredient of the method is an approximate line-search scheme and a collective treatment of two spin densities in the case of spin-dependent extended Thomas-Fermi problem. Test calculations for a quartic two-dimensional quantum dot system and a three-dimensional sodium cluster Na216 with a local pseudopotential demonstrate that the method is accurate and efficient. (c) 2004 American Institute of Physics.

Solution of the generalized Emden-Fowler equations by the hybrid functions method

International Nuclear Information System (INIS)

Tabrizidooz, H R; Marzban, H R; Razzaghi, M

2009-01-01

In this paper, we present a numerical algorithm for solving the generalized Emden-Fowler equations, which have many applications in mathematical physics and astrophysics. The method is based on hybrid functions approximations. The properties of hybrid functions, which consist of block-pulse functions and Lagrange interpolating polynomials, are presented. These properties are then utilized to reduce the computation of the generalized Emden-Fowler equations to a system of nonlinear equations. The method is easy to implement and yields very accurate results.

Design of New Test Function Model Based on Multi-objective Optimization Method

Directory of Open Access Journals (Sweden)

Zhaoxia Shang

2017-01-01

Full Text Available Space partitioning method, as a new algorism, has been applied to planning and decision-making of investment portfolio more and more often. But currently there are so few testing function for this algorism, which has greatly restrained its further development and application. An innovative test function model is designed in this paper and is used to test the algorism. It is proved that for evaluation of space partitioning method in certain applications, this test function has fairly obvious advantage.

Method and apparatus for controlling a powertrain system including a multi-mode transmission

Science.gov (United States)

Hessell, Steven M.; Morris, Robert L.; McGrogan, Sean W.; Heap, Anthony H.; Mendoza, Gil J.

2015-09-08

A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.

Harris functional and related methods for calculating total energies in density-functional theory

International Nuclear Information System (INIS)

Averill, F.W.; Painter, G.S.

1990-01-01

The simplified energy functional of Harris has given results of useful accuracy for systems well outside the limits of weakly interacting fragments for which the method was originally proposed. In the present study, we discuss the source of the frequent good agreement of the Harris energy with full Kohn-Sham self-consistent results. A procedure is described for extending the applicability of the scheme to more strongly interacting systems by going beyond the frozen-atom fragment approximation. A gradient-force expression is derived, based on the Harris functional, which accounts for errors in the fragment charge representation. Results are presented for some diatomic molecules, illustrating the points of this study

Introduction to functional and path integral methods in quantum field theory

International Nuclear Information System (INIS)

Strathdee, J.

1991-11-01

The following aspects concerning the use of functional and path integral methods in quantum field theory are discussed: generating functionals and the effective action, perturbation series, Yang-Mills theory and BRST symmetry. 10 refs, 3 figs

Heuristic method for determining outgoing waves in many-body wave functions

International Nuclear Information System (INIS)

Redish, E.F.; Tandy, P.C.; L'Huillier, M.

1975-12-01

A new and simple method is proposed for determining the kinds of outgoing waves present in a given many-body wave function. Whether any particular wave function contains ''hidden'' rearrangement components can be determined. 1 figure

Comparison of the auxiliary function method and the discrete-ordinate method for solving the radiative transfer equation for light scattering.

Science.gov (United States)

da Silva, Anabela; Elias, Mady; Andraud, Christine; Lafait, Jacques

2003-12-01

Two methods for solving the radiative transfer equation are compared with the aim of computing the angular distribution of the light scattered by a heterogeneous scattering medium composed of a single flat layer or a multilayer. The first method [auxiliary function method (AFM)], recently developed, uses an auxiliary function and leads to an exact solution; the second [discrete-ordinate method (DOM)] is based on the channel concept and needs an angular discretization. The comparison is applied to two different media presenting two typical and extreme scattering behaviors: Rayleigh and Mie scattering with smooth or very anisotropic phase functions, respectively. A very good agreement between the predictions of the two methods is observed in both cases. The larger the number of channels used in the DOM, the better the agreement. The principal advantages and limitations of each method are also listed.

A New Method of Creating Technology/Function Matrix for Systematic Innovation without Expert

Directory of Open Access Journals (Sweden)

Tien-Yuan Cheng

2012-02-01

Full Text Available The technology/function matrix is comprised by specific technologies and functions, and through the technology/function matrix we can known what the technologies with functions have opportunities for innovation of product or technology. However, the technology/function matrix is very difficult to create, because the patents need to be read, analyzed and categorized into the technology/function matrix always more than hundreds or thousands. In this research, I propose a method to create a technology/function matrix just need to execute patent search without reading and analyzing patents. Through the proposed method anyone can create a technology/function matrix in a short time without experts’ help even if there are thousands of thousands of patents need to be read and analyzed.

The study of system function analysis method for success path alarm design

International Nuclear Information System (INIS)

Kang, S. K.; Shin, Y. C.

1999-01-01

The key benefit to the common use of the critical function approach for safety and mission functions is that monitoring methods expected to be used by operaotrs during emergency condition are used continuously during normal operation. For each critical safety function there exists two or more success paths. Information Processing System monitors the availability, operation state and performance of the critical function success paths. In this paper, We have studied System Function Analysis(SFA) for the design of Success Path Alarm(SPA) for applying in KNGR. In here, we thought that SFA will help the design of SPA. The SFA can be applicable to the design of SPA according to NUREG-0711, also can induce the algorithm for alarm of system, train and flow path. We present a method of system function analysis for designing Success Path Alarm

The functional variable method for finding exact solutions of some ...

Indian Academy of Sciences (India)

Abstract. In this paper, we implemented the functional variable method and the modified. Riemann–Liouville derivative for the exact solitary wave solutions and periodic wave solutions of the time-fractional Klein–Gordon equation, and the time-fractional Hirota–Satsuma coupled. KdV system. This method is extremely simple ...

Validating the JobFit system functional assessment method

Energy Technology Data Exchange (ETDEWEB)

Jenny Legge; Robin Burgess-Limerick

2007-05-15

Workplace injuries are costing the Australian coal mining industry and its communities $410 Million a year. This ACARP study aims to meet those demands by developing a safe, reliable and valid pre-employment functional assessment tool. All JobFit System Pre-Employment Functional Assessments (PEFAs) consist of a musculoskeletal screen, balance test, aerobic fitness test and job-specific postural tolerances and material handling tasks. The results of each component are compared to the applicant's job demands and an overall PEFA score between 1 and 4 is given with 1 being the better score. The reliability study and validity study were conducted concurrently. The reliability study examined test-retest, intra-tester and inter-tester reliability of the JobFit System Functional Assessment Method. Overall, good to excellent reliability was found, which was sufficient to be used for comparison with injury data for determining the validity of the assessment. The overall assessment score and material handling tasks had the greatest reliability. The validity study compared the assessment results of 336 records from a Queensland underground and open cut coal mine with their injury records. A predictive relationship was found between PEFA score and the risk of a back/trunk/shoulder injury from manual handling. An association was also found between PEFA score of 1 and increased length of employment. Lower aerobic fitness test results had an inverse relationship with injury rates. The study found that underground workers, regardless of PEFA score, were more likely to have an injury when compared to other departments. No relationship was found between age and risk of injury. These results confirm the validity of the JobFit System Functional Assessment method.

Effective-range function methods for charged particle collisions

Science.gov (United States)

Gaspard, David; Sparenberg, Jean-Marc

2018-04-01

Different versions of the effective-range function method for charged particle collisions are studied and compared. In addition, a novel derivation of the standard effective-range function is presented from the analysis of Coulomb wave functions in the complex plane of the energy. The recently proposed effective-range function denoted as Δℓ [Ramírez Suárez and Sparenberg, Phys. Rev. C 96, 034601 (2017), 10.1103/PhysRevC.96.034601] and an earlier variant [Hamilton et al., Nucl. Phys. B 60, 443 (1973), 10.1016/0550-3213(73)90193-4] are related to the standard function. The potential interest of Δℓ for the study of low-energy cross sections and weakly bound states is discussed in the framework of the proton-proton S10 collision. The resonant state of the proton-proton collision is successfully computed from the extrapolation of Δℓ instead of the standard function. It is shown that interpolating Δℓ can lead to useful extrapolation to negative energies, provided scattering data are known below one nuclear Rydberg energy (12.5 keV for the proton-proton system). This property is due to the connection between Δℓ and the effective-range function by Hamilton et al. that is discussed in detail. Nevertheless, such extrapolations to negative energies should be used with caution because Δℓ is not analytic at zero energy. The expected analytic properties of the main functions are verified in the complex energy plane by graphical color-based representations.

Functional Imaging of Autonomic Regulation: Methods and Key Findings

Directory of Open Access Journals (Sweden)

Paul M Macey

2016-01-01

Full Text Available Central nervous system processing of autonomic function involves a network of regions throughout the brain which can be visualized and measured with neuroimaging techniques, notably functional magnetic resonance imaging (fMRI. The development of fMRI procedures has both confirmed and extended earlier findings from animal models, and human stroke and lesion studies. Assessments with fMRI can elucidate interactions between different central sites in regulating normal autonomic patterning, and demonstrate how disturbed systems can interact to produce aberrant regulation during autonomic challenges. Understanding autonomic dysfunction in various illnesses reveals mechanisms that potentially lead to interventions in the impairments. The objectives here are to: 1 describe the fMRI neuroimaging methodology for assessment of autonomic neural control, 2 outline the widespread, lateralized distribution of function in autonomic sites in the normal brain which includes structures from the neocortex through the medulla and cerebellum, 3 illustrate the importance of the time course of neural changes when coordinating responses, and how those patterns are impacted in conditions of sleep-disordered breathing, and 4 highlight opportunities for future research studies with emerging methodologies. Methodological considerations specific to autonomic testing include timing of challenges relative to the underlying fMRI signal, spatial resolution sufficient to identify autonomic brainstem nuclei, blood pressure and blood oxygenation influences on the fMRI signal, and the sustained timing, often measured in minutes of challenge periods and recovery. Key findings include the lateralized nature of autonomic organization, which is reminiscent of asymmetric motor, sensory and language pathways. Testing brain function during autonomic challenges demonstrate closely-integrated timing of responses in connected brain areas during autonomic challenges, and the involvement with

Curvelet-domain multiple matching method combined with cubic B-spline function

Science.gov (United States)

Wang, Tong; Wang, Deli; Tian, Mi; Hu, Bin; Liu, Chengming

2018-05-01

Since the large amount of surface-related multiple existed in the marine data would influence the results of data processing and interpretation seriously, many researchers had attempted to develop effective methods to remove them. The most successful surface-related multiple elimination method was proposed based on data-driven theory. However, the elimination effect was unsatisfactory due to the existence of amplitude and phase errors. Although the subsequent curvelet-domain multiple-primary separation method achieved better results, poor computational efficiency prevented its application. In this paper, we adopt the cubic B-spline function to improve the traditional curvelet multiple matching method. First, select a little number of unknowns as the basis points of the matching coefficient; second, apply the cubic B-spline function on these basis points to reconstruct the matching array; third, build constraint solving equation based on the relationships of predicted multiple, matching coefficients, and actual data; finally, use the BFGS algorithm to iterate and realize the fast-solving sparse constraint of multiple matching algorithm. Moreover, the soft-threshold method is used to make the method perform better. With the cubic B-spline function, the differences between predicted multiple and original data diminish, which results in less processing time to obtain optimal solutions and fewer iterative loops in the solving procedure based on the L1 norm constraint. The applications to synthetic and field-derived data both validate the practicability and validity of the method.

The functional variable method for solving the fractional Korteweg ...

Indian Academy of Sciences (India)

The physical and engineering processes have been modelled by means of fractional ... very important role in various fields such as economics, chemistry, notably control the- .... In §3, the functional variable method is applied for finding exact.

Measurement properties of existing clinical assessment methods evaluating scapular positioning and function. A systematic review

DEFF Research Database (Denmark)

Larsen, Camilla Marie; Juul-Kristensen, Birgit; Lund, Hans

%), with only one study rated as ‘good’. The reliability domain was most often investigated. Fewof the assessment methods in the included studies that had ‘fair’ or ‘good’ measurement properties demonstrated acceptable results for both reliability and validity.ConclusionWe found a substantially larger number......ABSTRACT OARSI Measurement properties of existing clinical assessment methods evaluating scapular positioning and function. A systematic review Larsen CM1, Juul-Kristensen B1,2 Lund H1,2, Søgaard K11University of Southern Denmark, Institute of Sports Science and Clinical Biomechanics2Institute...... assessment methods have measured the degree of scapular dyskinesis, subjectively by visual evaluation and objectively by measurements of static and dynamic scapular positioning, by either a 3-dimensional electromagnetic device or 2-dimensional clinically applicable methods. Since advanced equipment (i.e. 3D...

A Quadrature Method of Moments for Polydisperse Flow in Bubble Columns Including Poly-Celerity, Breakup and Coalescence

Directory of Open Access Journals (Sweden)

Thomas Acher

2014-12-01

Full Text Available A simulation model for 3D polydisperse bubble column flows in an Eulerian/Eulerian framework is presented. A computationally efficient and numerically stable algorithm is created by making use of quadrature method of moments (QMOM functionalities, in conjunction with appropriate breakup and coalescence models. To account for size dependent bubble motion, the constituent moments of the bubble size distribution function are transported with individual velocities. Validation of the simulation results against experimental and numerical data of Hansen [1] show the capability of the present model to accurately predict complex gas-liquid flows.

Modified Strum functions method in the nuclear three body problem

International Nuclear Information System (INIS)

Nasyrov, M.; Abdurakhmanov, A.; Yunusova, M.

1997-01-01

Fadeev-Hahn equations in the nuclear three-body problem were solved by modified Sturm functions method. Numerical calculations were carried out the square well potential. It was shown that the convergence of the method is high and the binding energy value is in agreement with experimental one (A.A.D.)

Methods of forming aluminum oxynitride-comprising bodies, including methods of forming a sheet of transparent armor

Science.gov (United States)

Chu, Henry Shiu-Hung [Idaho Falls, ID; Lillo, Thomas Martin [Idaho Falls, ID

2008-12-02

The invention includes methods of forming an aluminum oxynitride-comprising body. For example, a mixture is formed which comprises A:B:C in a respective molar ratio in the range of 9:3.6-6.2:0.1-1.1, where "A" is Al.sub.2O.sub.3, "B" is AlN, and "C" is a total of one or more of B.sub.2O.sub.3, SiO.sub.2, Si--Al--O--N, and TiO.sub.2. The mixture is sintered at a temperature of at least 1,600.degree. C. at a pressure of no greater than 500 psia effective to form an aluminum oxynitride-comprising body which is at least internally transparent and has at least 99% maximum theoretical density.

Classical density functional theory and the phase-field crystal method using a rational function to describe the two-body direct correlation function.

Science.gov (United States)

Pisutha-Arnond, N; Chan, V W L; Iyer, M; Gavini, V; Thornton, K

2013-01-01

We introduce a new approach to represent a two-body direct correlation function (DCF) in order to alleviate the computational demand of classical density functional theory (CDFT) and enhance the predictive capability of the phase-field crystal (PFC) method. The approach utilizes a rational function fit (RFF) to approximate the two-body DCF in Fourier space. We use the RFF to show that short-wavelength contributions of the two-body DCF play an important role in determining the thermodynamic properties of materials. We further show that using the RFF to empirically parametrize the two-body DCF allows us to obtain the thermodynamic properties of solids and liquids that agree with the results of CDFT simulations with the full two-body DCF without incurring significant computational costs. In addition, the RFF can also be used to improve the representation of the two-body DCF in the PFC method. Last, the RFF allows for a real-space reformulation of the CDFT and PFC method, which enables descriptions of nonperiodic systems and the use of nonuniform and adaptive grids.

Engine including hydraulically actuated valvetrain and method of valve overlap control

Science.gov (United States)

Cowgill, Joel [White Lake, MI

2012-05-08

An exhaust valve control method may include displacing an exhaust valve in communication with the combustion chamber of an engine to an open position using a hydraulic exhaust valve actuation system and returning the exhaust valve to a closed position using the hydraulic exhaust valve actuation assembly. During closing, the exhaust valve may be displaced for a first duration from the open position to an intermediate closing position at a first velocity by operating the hydraulic exhaust valve actuation assembly in a first mode. The exhaust valve may be displaced for a second duration greater than the first duration from the intermediate closing position to a fully closed position at a second velocity at least eighty percent less than the first velocity by operating the hydraulic exhaust valve actuation assembly in a second mode.

Modulating functions method for parameters estimation in the fifth order KdV equation

KAUST Repository

Asiri, Sharefa M.

2017-07-25

In this work, the modulating functions method is proposed for estimating coefficients in higher-order nonlinear partial differential equation which is the fifth order Kortewegde Vries (KdV) equation. The proposed method transforms the problem into a system of linear algebraic equations of the unknowns. The statistical properties of the modulating functions solution are described in this paper. In addition, guidelines for choosing the number of modulating functions, which is an important design parameter, are provided. The effectiveness and robustness of the proposed method are shown through numerical simulations in both noise-free and noisy cases.

Further Stable methods for the calculation of partition functions

International Nuclear Information System (INIS)

Wilson, B G; Gilleron, F; Pain, J

2007-01-01

The extension to recursion over holes of the Gilleron and Pain method for calculating partition functions of a canonical ensemble of non-interacting bound electrons is presented as well as a generalization for the efficient computation of collisional line broadening

Score Function of Distribution and Revival of the Moment Method

Czech Academy of Sciences Publication Activity Database

Fabián, Zdeněk

2016-01-01

Roč. 45, č. 4 (2016), s. 1118-1136 ISSN 0361-0926 R&D Projects: GA MŠk(CZ) LG12020 Institutional support: RVO:67985807 Keywords : characteristics of distributions * data characteristics * general moment method * Huber moment estimator * parametric methods * score function Subject RIV: BB - Applied Statistics , Operational Research Impact factor: 0.311, year: 2016

Exp-function method for constructing exact solutions of Sharma-Tasso-Olver equation

International Nuclear Information System (INIS)

Erbas, Baris; Yusufoglu, Elcin

2009-01-01

In this paper we use the Exp-function method for the analytic treatment of Sharma-Tasso-Olver equation. New solitonary solutions are formally derived. Change of parameters, which drastically changes the characteristics of the equations, is examined. It is shown that the Exp-function method provides a powerful mathematical tool for solving high-dimensional nonlinear evolutions in mathematical physics. The proposed schemes are reliable and manageable.

The MIMIC Method with Scale Purification for Detecting Differential Item Functioning

Science.gov (United States)

Wang, Wen-Chung; Shih, Ching-Lin; Yang, Chih-Chien

2009-01-01

This study implements a scale purification procedure onto the standard MIMIC method for differential item functioning (DIF) detection and assesses its performance through a series of simulations. It is found that the MIMIC method with scale purification (denoted as M-SP) outperforms the standard MIMIC method (denoted as M-ST) in controlling…

Grid refinement model in lattice Boltzmann method for stream function-vorticity formulations

Energy Technology Data Exchange (ETDEWEB)

Shin, Myung Seob [Dept. of Mechanical Engineering, Dongyang Mirae University, Seoul (Korea, Republic of)

2015-03-15

In this study, we present a grid refinement model in the lattice Boltzmann method (LBM) for two-dimensional incompressible fluid flow. That is, the model combines the desirable features of the lattice Boltzmann method and stream function-vorticity formulations. In order to obtain an accurate result, very fine grid (or lattice) is required near the solid boundary. Therefore, the grid refinement model is used in the lattice Boltzmann method for stream function-vorticity formulation. This approach is more efficient in that it can obtain the same accurate solution as that in single-block approach even if few lattices are used for computation. In order to validate the grid refinement approach for the stream function-vorticity formulation, the numerical simulations of lid-driven cavity flows were performed and good results were obtained.

Green's functions in quantum chemistry - I. The Σ perturbation method

International Nuclear Information System (INIS)

Sebastian, K.L.

1978-01-01

As an improvement over the Hartree-Fock approximation, a Green's Function method - the Σ perturbation method - is investigated for molecular calculations. The method is applied to the hydrogen molecule and to the π-electron system of ethylene under PPP approximation. It is found that when the algebraic approximation is used, the energy obtained is better than that of the HF approach, but is not as good as that of the configuration-interaction method. The main advantage of this procedure is that it is devoid of the most serious defect of HF method, viz. incorrect dissociation limits. (K.B.)

Analytic methods for the Percus-Yevick hard sphere correlation functions

Directory of Open Access Journals (Sweden)

D. Henderson

2009-01-01

Full Text Available The Percus-Yevick theory for hard spheres provides simple accurate expressions for the correlation functions that have proven exceptionally useful. A summary of the author's lecture notes concerning three methods of obtaining these functions are presented. These notes are original only in part. However, they contain some helpful steps and simplifications. The purpose of this paper is to make these notes more widely available.

Generalization of the influence function method in mining subsidence

International Nuclear Information System (INIS)

Bello Garcia, A.; Mendendez Diaz, A.; Ordieres Mere, J.B.; Gonzalez Nicieza, C.

1996-01-01

A generic approach to subsidence prediction based on the influence function method is presented. The changes proposed to the classical approach are the result of a previous analysis stage where a generalization to the 3D problem was made. In addition other hypothesis in order to relax the structural principles of the classical model are suggested. The quantitative results of this process and a brief discussion of its method of employment is presented. 13 refs., 8 figs., 5 tabs

Methods to determine fast-ion distribution functions from multi-diagnostic measurements

DEFF Research Database (Denmark)

Jacobsen, Asger Schou; Salewski, Mirko

-ion diagnostic views, it is possible to infer the distribution function using a tomography approach. Several inversion methods for solving this tomography problem in velocity space are implemented and compared. It is found that the best quality it obtained when using inversion methods which penalise steep......Understanding the behaviour of fast ions in a fusion plasma is very important, since the fusion-born alpha particles are expected to be the main source of heating in a fusion power plant. Preferably, the entire fast-ion velocity-space distribution function would be measured. However, no fast...

Method for determining the work hardening function to describe plasticity of metals

International Nuclear Information System (INIS)

Wilkins, M.L.

1978-01-01

A method for obtaining a constitutive relation that relates the flow stress to the equivalent plastic strain is developed. The method uses simple tension test data to suggest a functional form. This form is then used as a constitutive model in a computer program that simulates the tension test. The calculated results are compared with the experimental results and the functional form is refined until agreement is obtained between calculations and experiments. The importance of knowing the relationship between the flow stress and the plastic strain is discussed. A work hardening function is calibrated for 6061 T6 aluminum

Formal methods in design and verification of functional specifications

International Nuclear Information System (INIS)

Vaelisuo, H.

1995-01-01

It is claimed that formal methods should be applied already when specifying the functioning of the control/monitoring system, i.e. when planning how to implement the desired operation of the plant. Formal methods are seen as a way to mechanize and thus automate part of the planning. All mathematical methods which can be applied on related problem solving should be considered as formal methods. Because formal methods can only support the designer, not replace him/her, they must be integrated into a design support tool. Such a tool must also aid the designer in getting the correct conception of the plant and its behaviour. The use of a hypothetic design support tool is illustrated to clarify the requirements such a tool should fulfill. (author). 3 refs, 5 figs

Robust fractional order differentiators using generalized modulating functions method

KAUST Repository

Liu, Dayan

2015-02-01

This paper aims at designing a fractional order differentiator for a class of signals satisfying a linear differential equation with unknown parameters. A generalized modulating functions method is proposed first to estimate the unknown parameters, then to derive accurate integral formulae for the left-sided Riemann-Liouville fractional derivatives of the studied signal. Unlike the improper integral in the definition of the left-sided Riemann-Liouville fractional derivative, the integrals in the proposed formulae can be proper and be considered as a low-pass filter by choosing appropriate modulating functions. Hence, digital fractional order differentiators applicable for on-line applications are deduced using a numerical integration method in discrete noisy case. Moreover, some error analysis are given for noise error contributions due to a class of stochastic processes. Finally, numerical examples are given to show the accuracy and robustness of the proposed fractional order differentiators.

Robust fractional order differentiators using generalized modulating functions method

KAUST Repository

Liu, Dayan; Laleg-Kirati, Taous-Meriem

2015-01-01

This paper aims at designing a fractional order differentiator for a class of signals satisfying a linear differential equation with unknown parameters. A generalized modulating functions method is proposed first to estimate the unknown parameters, then to derive accurate integral formulae for the left-sided Riemann-Liouville fractional derivatives of the studied signal. Unlike the improper integral in the definition of the left-sided Riemann-Liouville fractional derivative, the integrals in the proposed formulae can be proper and be considered as a low-pass filter by choosing appropriate modulating functions. Hence, digital fractional order differentiators applicable for on-line applications are deduced using a numerical integration method in discrete noisy case. Moreover, some error analysis are given for noise error contributions due to a class of stochastic processes. Finally, numerical examples are given to show the accuracy and robustness of the proposed fractional order differentiators.

Performance analysis, quality function deployment and structured methods

Science.gov (United States)

Maier, M. W.

Quality function deployment, (QFD), an approach to synthesizing several elements of system modeling and design into a single unit, is presented. Behavioral, physical, and performance modeling are usually considered as separate aspects of system design without explicit linkages. Structured methodologies have developed linkages between behavioral and physical models before, but have not considered the integration of performance models. QFD integrates performance models with traditional structured models. In this method, performance requirements such as cost, weight, and detection range are partitioned into matrices. Partitioning is done by developing a performance model, preferably quantitative, for each requirement. The parameters of the model become the engineering objectives in a QFD analysis and the models are embedded in a spreadsheet version of the traditional QFD matrices. The performance model and its parameters are used to derive part of the functional model by recognizing that a given performance model implies some structure to the functionality of the system.

Functional Mobility Testing: A Novel Method to Create Suit Design Requirements

Science.gov (United States)

England, Scott A.; Benson, Elizabeth A.; Rajulu, Sudhakar L.

2008-01-01

This study was performed to aide in the creation of design requirements for the next generation of space suits that more accurately describe the level of mobility necessary for a suited crewmember through the use of an innovative methodology utilizing functional mobility. A novel method was utilized involving the collection of kinematic data while 20 subjects (10 male, 10 female) performed pertinent functional tasks that will be required of a suited crewmember during various phases of a lunar mission. These tasks were selected based on relevance and criticality from a larger list of tasks that may be carried out by the crew. Kinematic data was processed through Vicon BodyBuilder software to calculate joint angles for the ankle, knee, hip, torso, shoulder, elbow, and wrist. Maximum functional mobility was consistently lower than maximum isolated mobility. This study suggests that conventional methods for establishing design requirements for human-systems interfaces based on maximal isolated joint capabilities may overestimate the required mobility. Additionally, this method provides a valuable means of evaluating systems created from these requirements by comparing the mobility available in a new spacesuit, or the mobility required to use a new piece of hardware, to this newly established database of functional mobility.

Teaching Methods in Biology Education and Sustainability Education Including Outdoor Education for Promoting Sustainability—A Literature Review

Directory of Open Access Journals (Sweden)

Eila Jeronen

2016-12-01

Full Text Available There are very few studies concerning the importance of teaching methods in biology education and environmental education including outdoor education for promoting sustainability at the levels of primary and secondary schools and pre-service teacher education. The material was selected using special keywords from biology and sustainable education in several scientific databases. The article provides an overview of 24 selected articles published in peer-reviewed scientific journals from 2006–2016. The data was analyzed using qualitative content analysis. Altogether, 16 journals were selected and 24 articles were analyzed in detail. The foci of the analyses were teaching methods, learning environments, knowledge and thinking skills, psychomotor skills, emotions and attitudes, and evaluation methods. Additionally, features of good methods were investigated and their implications for teaching were emphasized. In total, 22 different teaching methods were found to improve sustainability education in different ways. The most emphasized teaching methods were those in which students worked in groups and participated actively in learning processes. Research points toward the value of teaching methods that provide a good introduction and supportive guidelines and include active participation and interactivity.

General Retarded Contact Self-energies in and beyond the Non-equilibrium Green's Functions Method

International Nuclear Information System (INIS)

Kubis, Tillmann; He, Yu; Andrawis, Robert; Klimeck, Gerhard

2016-01-01

Retarded contact self-energies in the framework of nonequilibrium Green's functions allow to model the impact of lead structures on the device without explicitly including the leads in the actual device calculation. Most of the contact self-energy algorithms are limited to homogeneous or periodic, semi-infinite lead structures. In this work, the complex absorbing potential method is extended to solve retarded contact self-energies for arbitrary lead structures, including irregular and randomly disordered leads. This method is verified for regular leads against common approaches and on physically equivalent, but numerically different irregular leads. Transmission results on randomly alloyed In 0.5 Ga 0.5 As structures show the importance of disorder in the leads. The concept of retarded contact self-energies is expanded to model passivation of atomically resolved surfaces without explicitly increasing the device's Hamiltonian. (paper)

APPROX, 1-D and 2-D Function Approximation by Polynomials, Splines, Finite Elements Method

International Nuclear Information System (INIS)

Tollander, Bengt

1975-01-01

1 - Nature of physical problem solved: Approximates one- and two- dimensional functions using different forms of the approximating function, as polynomials, rational functions, Splines and (or) the finite element method. Different kinds of transformations of the dependent and (or) the independent variables can easily be made by data cards using a FORTRAN-like language. 2 - Method of solution: Approximations by polynomials, Splines and (or) the finite element method are made in L2 norm using the least square method by which the answer is directly given. For rational functions in one dimension the result given in L(infinite) norm is achieved by iterations moving the zero points of the error curve. For rational functions in two dimensions, the norm is L2 and the result is achieved by iteratively changing the coefficients of the denominator and then solving the coefficients of the numerator by the least square method. The transformation of the dependent and (or) independent variables is made by compiling the given transform data card(s) to an array of integers from which the transformation can be made

Path integral solutions of the master equation. [Lagrangian function, Ehrenfest-type theorem, Cauchy method, inverse functions

Energy Technology Data Exchange (ETDEWEB)

Etim, E; Basili, C [Rome Univ. (Italy). Ist. di Matematica

1978-08-21

The lagrangian in the path integral solution of the master equation of a stationary Markov process is derived by application of the Ehrenfest-type theorem of quantum mechanics and the Cauchy method of finding inverse functions. Applied to the non-linear Fokker-Planck equation the authors reproduce the result obtained by integrating over Fourier series coefficients and by other methods.

Development of new methods in modern selective organic synthesis: preparation of functionalized molecules with atomic precision

International Nuclear Information System (INIS)

Ananikov, V P; Khemchyan, L L; Ivanova, Yu V; Dilman, A D; Levin, V V; Bukhtiyarov, V I; Sorokin, A M; Prosvirin, I P; Romanenko, A V; Simonov, P A; Vatsadze, S Z; Medved'ko, A V; Nuriev, V N; Nenajdenko, V G; Shmatova, O I; Muzalevskiy, V M; Koptyug, I V; Kovtunov, K V; Zhivonitko, V V; Likholobov, V A

2014-01-01

The challenges of the modern society and the growing demand of high-technology sectors of industrial production bring about a new phase in the development of organic synthesis. A cutting edge of modern synthetic methods is introduction of functional groups and more complex structural units into organic molecules with unprecedented control over the course of chemical transformation. Analysis of the state-of-the-art achievements in selective organic synthesis indicates the appearance of a new trend — the synthesis of organic molecules, biologically active compounds, pharmaceutical substances and smart materials with absolute selectivity. Most advanced approaches to organic synthesis anticipated in the near future can be defined as 'atomic precision' in chemical reactions. The present review considers selective methods of organic synthesis suitable for transformation of complex functionalized molecules under mild conditions. Selected key trends in the modern organic synthesis are considered including the preparation of organofluorine compounds, catalytic cross-coupling and oxidative cross-coupling reactions, atom-economic addition reactions, methathesis processes, oxidation and reduction reactions, synthesis of heterocyclic compounds, design of new homogeneous and heterogeneous catalytic systems, application of photocatalysis, scaling up synthetic procedures to industrial level and development of new approaches to investigation of mechanisms of catalytic reactions. The bibliography includes 840 references

A hybrid method for the parallel computation of Green’s functions

DEFF Research Database (Denmark)

Petersen, Dan Erik; Li, Song; Stokbro, Kurt

2009-01-01

Quantum transport models for nanodevices using the non-equilibrium Green’s function method require the repeated calculation of the block tridiagonal part of the Green’s and lesser Green’s function matrices. This problem is related to the calculation of the inverse of a sparse matrix. Because of t...

The inclusion of long-range polarisation functions in calculations of low-energy e+-H2 scattering using the Kohn method

International Nuclear Information System (INIS)

Armour, E.A.G.; Plummer, M.

1989-01-01

An explanation is given of why it is necessary to include long-range polarisation functions in the trial function when carrying out Kohn calculations of low-energy positron (and electron) scattering by atoms and simple molecules. The asymptotic form of these functions in low-energy e + -H 2 scattering is deduced. Appropriate functions with this asymptotic form are used to represent the closed-channel part of the wavefunction in a Kohn calculation of the lowest partial wave of Σ u + symmetry in e + -H 2 scattering at very low energies. For k≤0.03a 0 -1 , the results obtained are in good agreement with those obtained using the Born approximation and the asymptotic forms of the static and polarisation potentials. The relationship is pointed out between this method of taking into account long-range polarisation and the polarised pseudostate method used in R-matrix calculations. (author)

The Method of a Standalone Functional Verifying Operability of Sonar Control Systems

Directory of Open Access Journals (Sweden)

A. A. Sotnikov

2014-01-01

Full Text Available This article describes a method of standalone verifying sonar control system, which is based on functional checking of control system operability.The main features of realized method are a development of the valid mathematic model for simulation of sonar signals at the point of hydroacoustic antenna, a valid representation of the sonar control system modes as a discrete Markov model, providing functional object verification in real time mode.Some ways are proposed to control computational complexity in case of insufficient computing resources of the simulation equipment, namely the way of model functionality reduction and the way of adequacy reduction.Experiments were made using testing equipment, which was developed by department of Research Institute of Information Control System at Bauman Moscow State Technical University to verify technical validity of industrial sonar complexes.On-board software was artificially changed to create malfunctions in functionality of sonar control systems during the verifying process in order to estimate verifying system performances.The method efficiency was proved by the theory and experiment results in comparison with the basic methodology of verifying technical systems.This method could be also used in debugging of on-board software of sonar complexes and in development of new promising algorithms of sonar signal processing.

Critical comparison between equation of motion-Green's function methods and configuration interaction methods: analysis of methods and applications

International Nuclear Information System (INIS)

Freed, K.F.; Herman, M.F.; Yeager, D.L.

1980-01-01

A description is provided of the common conceptual origins of many-body equations of motion and Green's function methods in Liouville operator formulations of the quantum mechanics of atomic and molecular electronic structure. Numerical evidence is provided to show the inadequacies of the traditional strictly perturbative approaches to these methods. Nonperturbative methods are introduced by analogy with techniques developed for handling large configuration interaction calculations and by evaluating individual matrix elements to higher accuracy. The important role of higher excitations is exhibited by the numerical calculations, and explicit comparisons are made between converged equations of motion and configuration interaction calculations for systems where a fundamental theorem requires the equality of the energy differences produced by these different approaches. (Auth.)

Acquiring molecular interference functions of X-ray coherent scattering for breast tissues by combination of simulation and experimental methods

International Nuclear Information System (INIS)

Chaparian, A.; Oghabian, M. A.; Changizi, V.

2009-01-01

Recently, it has been indicated that X-ray coherent scatter from biological tissues can be used to access signature of tissue. Some scientists are interested in studying this effect to get early detection of breast cancer. Since experimental methods for optimization are time consuming and expensive, some scientists suggest using simulation. Monte Carlo codes are the best option for radiation simulation: however, one permanent defect with Monte Carlo codes has been the lack of a sufficient physical model for coherent (Rayleigh) scattering, including molecular interference effects. Materials and Methods: It was decided to obtain molecular interference functions of coherent X-ray scattering for normal breast tissues by combination of modeling and experimental methods. A Monte Carlo simulation program was written to simulate the angular distribution of scattered photons for the normal breast tissue samples. Moreover, experimental diffraction patterns of these tissues were measured by means of energy dispersive X-ray diffraction method. The simulation and experimental data were used to obtain a tabulation of molecular interference functions for breast tissues. Results: With this study a tabulation of molecular interference functions for normal breast tissues Was prepared to facilitate the simulation diffraction patterns of the tissues without any experimental. Conclusion: The method may lead to design new systems for early detection of breast cancer.

Solving Nonlinear Fractional Differential Equation by Generalized Mittag-Leffler Function Method

Science.gov (United States)

Arafa, A. A. M.; Rida, S. Z.; Mohammadein, A. A.; Ali, H. M.

2013-06-01

In this paper, we use Mittag—Leffler function method for solving some nonlinear fractional differential equations. A new solution is constructed in power series. The fractional derivatives are described by Caputo's sense. To illustrate the reliability of the method, some examples are provided.

Application of Exp-function method to potential Kadomtsev-Petviashvili equation

International Nuclear Information System (INIS)

Xian Daquan; Dai Zhengde

2009-01-01

Exact periodic kink-wave solution, periodic soliton and doubly periodic solutions for the potential Kadomtsev-Petviashvii (PKP) equation are obtained using Exp-function method with the help of Maple computation.

High heterogeneity in methods used for the laboratory confirmation of pertussis diagnosis among European countries, 2010: integration of epidemiological and laboratory surveillance must include standardisation of methodologies and quality assurance.

Science.gov (United States)

He, Q; Barkoff, A M; Mertsola, J; Glismann, S; Bacci, S

2012-08-09

Despite extensive childhood immunisation, pertussis remains one of the world’s leading causes of vaccine preventable deaths. The current methods used for laboratory diagnosis of pertussis include bacterial culture, polymerase chain reaction (PCR) and enzyme linked immunosorbent assay (ELISA) serology. We conducted a questionnaire survey to identify variations in the laboratory methods and protocols used among participating countries included in the European surveillance network for vaccine-preventable diseases(EUVAC.NET). In February 2010, we performed the survey using a web-based questionnaire and sent it to the country experts of 25 European Union countries,and two European Economic Area (EEA) countries,Norway and Iceland. The questionnaire consisted of 37 questions which covered both general information on surveillance methods and detailed laboratory methods used. A descriptive analysis was performed.Questionnaires were answered by all 27 contacted countries. Nineteen countries had pertussis reference laboratories at the national level; their functions varied from performing diagnosis to providing technical advice for routine microbiology laboratories. Culture,PCR and serology were used in 17, 18 and 20 countries,respectively. For PCR, nine laboratories used insertion sequence IS481 as the target gene, which is present in multiple copies in the Bordetella pertussis genome and thus has a greater sensitivity over single copy targets, but has been proved not to be specific for B.pertussis. Antibodies directed against pertussis toxin(PT) are specific for B. pertussis infections. For ELISA serology, only 13 countries’ laboratories used purified PT as coating antigen and 10 included World Health Organization (WHO) or Food and Drug Administration (FDA) reference sera in their tests. This present survey shows that methods used for laboratory confirmation of pertussis differ widely among European countries and that there is a great heterogeneity of the reference

Time-dependent density-functional theory in the projector augmented-wave method

DEFF Research Database (Denmark)

Walter, Michael; Häkkinen, Hannu; Lehtovaara, Lauri

2008-01-01

We present the implementation of the time-dependent density-functional theory both in linear-response and in time-propagation formalisms using the projector augmented-wave method in real-space grids. The two technically very different methods are compared in the linear-response regime where we...

A new promising screening method for cognitive functioning in elderly patients

NARCIS (Netherlands)

Kuin, Y.; Nijsten, J.M.H.; Stok-Koch, E.G.H.J.; Jansen, R.W.M.M.

1996-01-01

The Mini Mental State Examination (MMSE) is frequently used as a screening method to detect cognitive dysfunctioning. However, the MMSE has limited sensitivity to detect mild impairment. We aimed to develop a new screening method to discriminate between normal and mild cognitive functioning in older

Consensus for nonmelanoma skin cancer treatment: basal cell carcinoma, including a cost analysis of treatment methods.

Science.gov (United States)

Kauvar, Arielle N B; Cronin, Terrence; Roenigk, Randall; Hruza, George; Bennett, Richard

2015-05-01

Basal cell carcinoma (BCC) is the most common cancer in the US population affecting approximately 2.8 million people per year. Basal cell carcinomas are usually slow-growing and rarely metastasize, but they do cause localized tissue destruction, compromised function, and cosmetic disfigurement. To provide clinicians with guidelines for the management of BCC based on evidence from a comprehensive literature review, and consensus among the authors. An extensive review of the medical literature was conducted to evaluate the optimal treatment methods for cutaneous BCC, taking into consideration cure rates, recurrence rates, aesthetic and functional outcomes, and cost-effectiveness of the procedures. Surgical approaches provide the best outcomes for BCCs. Mohs micrographic surgery provides the highest cure rates while maximizing tissue preservation, maintenance of function, and cosmesis. Mohs micrographic surgery is an efficient and cost-effective procedure and remains the treatment of choice for high-risk BCCs and for those in cosmetically sensitive locations. Nonsurgical modalities may be used for low-risk BCCs when surgery is contraindicated or impractical, but the cure rates are lower.

Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation

Energy Technology Data Exchange (ETDEWEB)

Green, Daniel M., E-mail: daniel.green@stjude.org [Department of Epidemiology and Cancer Control, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Billups, Catherine A. [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Stokes, Dennis C. [Department of Pediatrics, University of Tennessee School of Medicine, Memphis, Tennessee (United States); Broniscer, Alberto [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Bartels, Ute [Department of Haematology and Oncology, The Hospital for Sick Children, Toronto, Ontario (Canada); Chintagumpala, Murali [Department of Pediatric Medicine, Texas Children' s Cancer and Hematology Centers, Baylor College of Medicine, Houston, Texas (United States); Hassall, Timothy E. [Department of Haematology and Oncology, Royal Children' s Hospital, Brisbane (Australia); Gururangan, Sridharan [Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (United States); McCowage, Geoffrey B. [Department of Pediatrics, Children' s Hospital at Westmead, Sydney (Australia); Heath, John A. [Children' s Cancer Center, Royal Children' s Hospital Melbourne, Melbourne (Australia); Cohn, Richard J. [Department of Clinical Oncology, Sydney Children' s Hospital, Sydney (Australia); Fisher, Michael J. [Department of Pediatrics, Children' s Hospital of Philadelphia, Philadelphia, Pennsylvania (United States); Srinivasan, Ashok [Department of Bone Marrow Transplantation & Cellular Therapy, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Robinson, Giles W.; Gajjar, Amar [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

2015-09-01

Purpose: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. Methods: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV{sub 1}] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO{sub corr}]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. Results: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose: ≤2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m{sup 2} (IQR, 15.7-16.0 g/m{sup 2}). At 24 and 60 months ACT, DLCO{sub corr} was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV{sub 1} was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO{sub corr} was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P=.028) and 60 months ACT (MD in % predicted, 6.00%; P=.033) compared with the end of radiation therapy. These significant decreases in DLCO{sub corr} were also observed in repeated-measures models (P=.011 and P=.032 at 24 and 60 months ACT, respectively). Conclusions: A significant minority of EBT survivors experience PFT deficits after CSI

Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation

International Nuclear Information System (INIS)

Green, Daniel M.; Merchant, Thomas E.; Billups, Catherine A.; Stokes, Dennis C.; Broniscer, Alberto; Bartels, Ute; Chintagumpala, Murali; Hassall, Timothy E.; Gururangan, Sridharan; McCowage, Geoffrey B.; Heath, John A.; Cohn, Richard J.; Fisher, Michael J.; Srinivasan, Ashok; Robinson, Giles W.; Gajjar, Amar

2015-01-01

Purpose: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. Methods: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV 1 ] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO corr ]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. Results: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose: ≤2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m 2 (IQR, 15.7-16.0 g/m 2 ). At 24 and 60 months ACT, DLCO corr was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV 1 was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO corr was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P=.028) and 60 months ACT (MD in % predicted, 6.00%; P=.033) compared with the end of radiation therapy. These significant decreases in DLCO corr were also observed in repeated-measures models (P=.011 and P=.032 at 24 and 60 months ACT, respectively). Conclusions: A significant minority of EBT survivors experience PFT deficits after CSI. Continued monitoring of this cohort

Methods of using structures including catalytic materials disposed within porous zeolite materials to synthesize hydrocarbons

Science.gov (United States)

Rollins, Harry W [Idaho Falls, ID; Petkovic, Lucia M [Idaho Falls, ID; Ginosar, Daniel M [Idaho Falls, ID

2011-02-01

Catalytic structures include a catalytic material disposed within a zeolite material. The catalytic material may be capable of catalyzing a formation of methanol from carbon monoxide and/or carbon dioxide, and the zeolite material may be capable of catalyzing a formation of hydrocarbon molecules from methanol. The catalytic material may include copper and zinc oxide. The zeolite material may include a first plurality of pores substantially defined by a crystal structure of the zeolite material and a second plurality of pores dispersed throughout the zeolite material. Systems for synthesizing hydrocarbon molecules also include catalytic structures. Methods for synthesizing hydrocarbon molecules include contacting hydrogen and at least one of carbon monoxide and carbon dioxide with such catalytic structures. Catalytic structures are fabricated by forming a zeolite material at least partially around a template structure, removing the template structure, and introducing a catalytic material into the zeolite material.

Psychophysical "blinding" methods reveal a functional hierarchy of unconscious visual processing.

Science.gov (United States)

Breitmeyer, Bruno G

2015-09-01

Numerous non-invasive experimental "blinding" methods exist for suppressing the phenomenal awareness of visual stimuli. Not all of these suppressive methods occur at, and thus index, the same level of unconscious visual processing. This suggests that a functional hierarchy of unconscious visual processing can in principle be established. The empirical results of extant studies that have used a number of different methods and additional reasonable theoretical considerations suggest the following tentative hierarchy. At the highest levels in this hierarchy is unconscious processing indexed by object-substitution masking. The functional levels indexed by crowding, the attentional blink (and other attentional blinding methods), backward pattern masking, metacontrast masking, continuous flash suppression, sandwich masking, and single-flash interocular suppression, fall at progressively lower levels, while unconscious processing at the lowest levels is indexed by eye-based binocular-rivalry suppression. Although unconscious processing levels indexed by additional blinding methods is yet to be determined, a tentative placement at lower levels in the hierarchy is also given for unconscious processing indexed by Troxler fading and adaptation-induced blindness, and at higher levels in the hierarchy indexed by attentional blinding effects in addition to the level indexed by the attentional blink. The full mapping of levels in the functional hierarchy onto cortical activation sites and levels is yet to be determined. The existence of such a hierarchy bears importantly on the search for, and the distinctions between, neural correlates of conscious and unconscious vision. Copyright © 2015 Elsevier Inc. All rights reserved.

An Approximate Proximal Bundle Method to Minimize a Class of Maximum Eigenvalue Functions

Directory of Open Access Journals (Sweden)

Wei Wang

2014-01-01

Full Text Available We present an approximate nonsmooth algorithm to solve a minimization problem, in which the objective function is the sum of a maximum eigenvalue function of matrices and a convex function. The essential idea to solve the optimization problem in this paper is similar to the thought of proximal bundle method, but the difference is that we choose approximate subgradient and function value to construct approximate cutting-plane model to solve the above mentioned problem. An important advantage of the approximate cutting-plane model for objective function is that it is more stable than cutting-plane model. In addition, the approximate proximal bundle method algorithm can be given. Furthermore, the sequences generated by the algorithm converge to the optimal solution of the original problem.

Spine surgeon's kinematics during discectomy, part II: operating table height and visualization methods, including microscope.

Science.gov (United States)

Park, Jeong Yoon; Kim, Kyung Hyun; Kuh, Sung Uk; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

2014-05-01

Surgeon spine angle during surgery was studied ergonomically and the kinematics of the surgeon's spine was related with musculoskeletal fatigue and pain. Spine angles varied depending on operation table height and visualization method, and in a previous paper we showed that the use of a loupe and a table height at the midpoint between the umbilicus and the sternum are optimal for reducing musculoskeletal loading. However, no studies have previously included a microscope as a possible visualization method. The objective of this study is to assess differences in surgeon spine angles depending on operating table height and visualization method, including microscope. We enrolled 18 experienced spine surgeons for this study, who each performed a discectomy using a spine surgery simulator. Three different methods were used to visualize the surgical field (naked eye, loupe, microscope) and three different operating table heights (anterior superior iliac spine, umbilicus, the midpoint between the umbilicus and the sternum) were studied. Whole spine angles were compared for three different views during the discectomy simulation: midline, ipsilateral, and contralateral. A 16-camera optoelectronic motion analysis system was used, and 16 markers were placed from the head to the pelvis. Lumbar lordosis, thoracic kyphosis, cervical lordosis, and occipital angle were compared between the different operating table heights and visualization methods as well as a natural standing position. Whole spine angles differed significantly depending on visualization method. All parameters were closer to natural standing values when discectomy was performed with a microscope, and there were no differences between the naked eye and the loupe. Whole spine angles were also found to differ from the natural standing position depending on operating table height, and became closer to natural standing position values as the operating table height increased, independent of the visualization method

An integrated miRNA functional screening and target validation method for organ morphogenesis.

Science.gov (United States)

Rebustini, Ivan T; Vlahos, Maryann; Packer, Trevor; Kukuruzinska, Maria A; Maas, Richard L

2016-03-16

The relative ease of identifying microRNAs and their increasing recognition as important regulators of organogenesis motivate the development of methods to efficiently assess microRNA function during organ morphogenesis. In this context, embryonic organ explants provide a reliable and reproducible system that recapitulates some of the important early morphogenetic processes during organ development. Here we present a method to target microRNA function in explanted mouse embryonic organs. Our method combines the use of peptide-based nanoparticles to transfect specific microRNA inhibitors or activators into embryonic organ explants, with a microRNA pulldown assay that allows direct identification of microRNA targets. This method provides effective assessment of microRNA function during organ morphogenesis, allows prioritization of multiple microRNAs in parallel for subsequent genetic approaches, and can be applied to a variety of embryonic organs.

Quasi-Newton methods for parameter estimation in functional differential equations

Science.gov (United States)

Brewer, Dennis W.

1988-01-01

A state-space approach to parameter estimation in linear functional differential equations is developed using the theory of linear evolution equations. A locally convergent quasi-Newton type algorithm is applied to distributed systems with particular emphasis on parameters that induce unbounded perturbations of the state. The algorithm is computationally implemented on several functional differential equations, including coefficient and delay estimation in linear delay-differential equations.

A new generalized exponential rational function method to find exact special solutions for the resonance nonlinear Schrödinger equation

Science.gov (United States)

Ghanbari, Behzad; Inc, Mustafa

2018-04-01

The present paper suggests a novel technique to acquire exact solutions of nonlinear partial differential equations. The main idea of the method is to generalize the exponential rational function method. In order to examine the ability of the method, we consider the resonant nonlinear Schrödinger equation (R-NLSE). Many variants of exact soliton solutions for the equation are derived by the proposed method. Physical interpretations of some obtained solutions is also included. One can easily conclude that the new proposed method is very efficient and finds the exact solutions of the equation in a relatively easy way.

Approximation of the Doppler broadening function by Frobenius method

International Nuclear Information System (INIS)

Palma, Daniel A.P.; Martinez, Aquilino S.; Silva, Fernando C.

2005-01-01

An analytical approximation of the Doppler broadening function ψ(x,ξ) is proposed. This approximation is based on the solution of the differential equation for ψ(x,ξ) using the methods of Frobenius and the parameters variation. The analytical form derived for ψ(x,ξ) in terms of elementary functions is very simple and precise. It can be useful for applications related to the treatment of nuclear resonances mainly for the calculations of multigroup parameters and self-protection factors of the resonances, being the last used to correct microscopic cross-sections measurements by the activation technique. (author)

A SVM-based quantitative fMRI method for resting-state functional network detection.

Science.gov (United States)

Song, Xiaomu; Chen, Nan-kuei

2014-09-01

Resting-state functional magnetic resonance imaging (fMRI) aims to measure baseline neuronal connectivity independent of specific functional tasks and to capture changes in the connectivity due to neurological diseases. Most existing network detection methods rely on a fixed threshold to identify functionally connected voxels under the resting state. Due to fMRI non-stationarity, the threshold cannot adapt to variation of data characteristics across sessions and subjects, and generates unreliable mapping results. In this study, a new method is presented for resting-state fMRI data analysis. Specifically, the resting-state network mapping is formulated as an outlier detection process that is implemented using one-class support vector machine (SVM). The results are refined by using a spatial-feature domain prototype selection method and two-class SVM reclassification. The final decision on each voxel is made by comparing its probabilities of functionally connected and unconnected instead of a threshold. Multiple features for resting-state analysis were extracted and examined using an SVM-based feature selection method, and the most representative features were identified. The proposed method was evaluated using synthetic and experimental fMRI data. A comparison study was also performed with independent component analysis (ICA) and correlation analysis. The experimental results show that the proposed method can provide comparable or better network detection performance than ICA and correlation analysis. The method is potentially applicable to various resting-state quantitative fMRI studies. Copyright © 2014 Elsevier Inc. All rights reserved.

Assessment of Methods to Consolidate Iodine-Loaded Silver-Functionalized Silica Aerogel

Energy Technology Data Exchange (ETDEWEB)

Matyas, Josef; Engler, Robert K.

2013-09-01

The U.S. Department of Energy is currently investigating alternative sorbents for the removal and immobilization of radioiodine from the gas streams in a nuclear fuel reprocessing plant. One of these new sorbents, Ag0-functionalized silica aerogels, shows great promise as a potential replacement for Ag-bearing mordenites because of its high selectivity and sorption capacity for iodine. Moreover, a feasible consolidation of iodine-loaded Ag0-functionalized silica aerogels to a durable SiO2-based waste form makes this aerogel an attractive choice for sequestering radioiodine. This report provides a preliminary assessment of the methods that can be used to consolidate iodine-loaded Ag0-functionalized silica aerogels into a final waste form. In particular, it focuses on experimental investigation of densification of as prepared Ag0-functionalized silica aerogels powders, with or without organic moiety and with or without sintering additive (colloidal silica), with three commercially available techniques: 1) hot uniaxial pressing (HUP), 2) hot isostatic pressing (HIP), and 3) spark plasma sintering (SPS). The densified products were evaluated with helium gas pycnometer for apparent density, with the Archimedes method for apparent density and open porosity, and with high-resolution scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) for the extent of densification and distribution of individual elements. The preliminary investigation of HUP, HIP, and SPS showed that these sintering methods can effectively consolidate powders of Ag0-functionalized silica aerogel into products of near-theoretical density. Also, removal of organic moiety and adding 5.6 mass% of colloidal silica to Ag0-functionalized silica aerogel powders before processing provided denser products. Furthermore, the ram travel data for SPS indicated that rapid consolidation of powders can be performed at temperatures below 950°C.

Wave resistance calculation method combining Green functions based on Rankine and Kelvin source

Directory of Open Access Journals (Sweden)

LI Jingyu

2017-12-01

Full Text Available [Ojectives] At present, the Boundary Element Method(BEM of wave-making resistance mostly uses a model in which the velocity distribution near the hull is solved first, and the pressure integral is then calculated using the Bernoulli equation. However,the process of this model of wave-making resistance is complex and has low accuracy.[Methods] To address this problem, the present paper deduces a compound method for the quick calculation of ship wave resistance using the Rankine source Green function to solve the hull surface's source density, and combining the Lagally theorem concerning source point force calculation based on the Kelvin source Green function so as to solve the wave resistance. A case for the Wigley model is given.[Results] The results show that in contrast to the thin ship method of the linear wave resistance theorem, this method has higher precision, and in contrast to the method which completely uses the Kelvin source Green function, this method has better computational efficiency.[Conclusions] In general, the algorithm in this paper provides a compromise between precision and efficiency in wave-making resistance calculation.

Lagrange polynomial interpolation method applied in the calculation of the J({xi},{beta}) function

Energy Technology Data Exchange (ETDEWEB)

Fraga, Vinicius Munhoz; Palma, Daniel Artur Pinheiro [Centro Federal de Educacao Tecnologica de Quimica de Nilopolis, RJ (Brazil)]. E-mails: munhoz.vf@gmail.com; dpalma@cefeteq.br; Martinez, Aquilino Senra [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE) (COPPE). Programa de Engenharia Nuclear]. E-mail: aquilino@lmp.ufrj.br

2008-07-01

The explicit dependence of the Doppler broadening function creates difficulties in the obtaining an analytical expression for J function . The objective of this paper is to present a method for the quick and accurate calculation of J function based on the recent advances in the calculation of the Doppler broadening function and on a systematic analysis of its integrand. The methodology proposed, of a semi-analytical nature, uses the Lagrange polynomial interpolation method and the Frobenius formulation in the calculation of Doppler broadening function . The results have proven satisfactory from the standpoint of accuracy and processing time. (author)

Lagrange polynomial interpolation method applied in the calculation of the J(ξ,β) function

International Nuclear Information System (INIS)

Fraga, Vinicius Munhoz; Palma, Daniel Artur Pinheiro; Martinez, Aquilino Senra

2008-01-01

The explicit dependence of the Doppler broadening function creates difficulties in the obtaining an analytical expression for J function . The objective of this paper is to present a method for the quick and accurate calculation of J function based on the recent advances in the calculation of the Doppler broadening function and on a systematic analysis of its integrand. The methodology proposed, of a semi-analytical nature, uses the Lagrange polynomial interpolation method and the Frobenius formulation in the calculation of Doppler broadening function . The results have proven satisfactory from the standpoint of accuracy and processing time. (author)

[Pituitary function of dysgenesic femal rats. Studies with grafting method].

Science.gov (United States)

Vanhems, E; Busquet, J

1975-01-01

Misulban administered to pregnant rats on the 15th day of gestation provoked gonadal dysgenesia in the offspring. Study of the pituitary function of dysgenesic female rats, realized by grafting method, showed gonadotrophic hypersecretion.

Kidney function tests

Science.gov (United States)

Kidney function tests are common lab tests used to evaluate how well the kidneys are working. Such tests include: ... Oh MS, Briefel G. Evaluation of renal function, water, electrolytes ... and Management by Laboratory Methods . 23rd ed. Philadelphia, ...

[Functional methods of the esophagus examination].

Science.gov (United States)

Valitova, E R; Bordin, D S; Ianova, O B; Vasnev, O S; Masharova, A A

2010-01-01

Manometry of the esophagus is the "gold standard" in diagnosing diseases of the esophagus associated with motor disorders. The combination of manometry with impedance gives an indication of violation of bolus transport along the esophagus. High resolution manometry is new method that provides the most accurate information about the functional anatomy of the esophagus and its sphincters, as well as accurately characterizes the esophageal-gastric junction. We can increase the diagnostic value of daily pH-monitoring by analyzing communication with reflux symptoms. The combination of pH and impedance can identify different types of reflux (acid, sour, gas, liquid and mixed) in patients with symptoms of GERD and related Ahil, after gastric resection in children and infants, to evaluate the effectiveness of antireflux therapy.

Functional development in density functional theory for superconductors

Energy Technology Data Exchange (ETDEWEB)

Sanna, Antonio; Gross, E.K.U.; Essenberger, Frank [Max Planck Institute of Microstructure Physics, Halle (Saale) (Germany)

2015-07-01

Density functional theory for superconductors (SCDFT) is a fully parameter-free approach to superconductivity that allows for accurate predictions of critical temperature and properties of superconductors. We report on the most recent extensions of the method, in particular the development of new functionals to: (1) incorporate in a correct fashion Migdal's theorem; (2) compute the excitation spectrum; (3) include spin-fluctuation mediated pairing Applications and predictions are shown for a set of materials, including conventional and unconventional superconductors.

Statistical limitations in functional neuroimaging. I. Non-inferential methods and statistical models.

Science.gov (United States)

Petersson, K M; Nichols, T E; Poline, J B; Holmes, A P

1999-01-01

Functional neuroimaging (FNI) provides experimental access to the intact living brain making it possible to study higher cognitive functions in humans. In this review and in a companion paper in this issue, we discuss some common methods used to analyse FNI data. The emphasis in both papers is on assumptions and limitations of the methods reviewed. There are several methods available to analyse FNI data indicating that none is optimal for all purposes. In order to make optimal use of the methods available it is important to know the limits of applicability. For the interpretation of FNI results it is also important to take into account the assumptions, approximations and inherent limitations of the methods used. This paper gives a brief overview over some non-inferential descriptive methods and common statistical models used in FNI. Issues relating to the complex problem of model selection are discussed. In general, proper model selection is a necessary prerequisite for the validity of the subsequent statistical inference. The non-inferential section describes methods that, combined with inspection of parameter estimates and other simple measures, can aid in the process of model selection and verification of assumptions. The section on statistical models covers approaches to global normalization and some aspects of univariate, multivariate, and Bayesian models. Finally, approaches to functional connectivity and effective connectivity are discussed. In the companion paper we review issues related to signal detection and statistical inference. PMID:10466149

Exact traveling wave solutions of fractional order Boussinesq-like equations by applying Exp-function method

Science.gov (United States)

Rahmatullah; Ellahi, Rahmat; Mohyud-Din, Syed Tauseef; Khan, Umar

2018-03-01

We have computed new exact traveling wave solutions, including complex solutions of fractional order Boussinesq-Like equations, occurring in physical sciences and engineering, by applying Exp-function method. The method is blended with fractional complex transformation and modified Riemann-Liouville fractional order operator. Our obtained solutions are verified by substituting back into their corresponding equations. To the best of our knowledge, no other technique has been reported to cope with the said fractional order nonlinear problems combined with variety of exact solutions. Graphically, fractional order solution curves are shown to be strongly related to each other and most importantly, tend to fixate on their integer order solution curve. Our solutions comprise high frequencies and very small amplitude of the wave responses.

Green's function method for the monoenergetic transport equation in heterogeneous plane geometry

International Nuclear Information System (INIS)

Ganapol, B.D.

1995-01-01

For the past several years, a series of papers by the transport group at the University of Arizona dealing with benchmark solutions of the monoenergetic transport equation has appeared. The approach has been to take advantage of highly successful numerical Laplace Fourier transform inversions to provide benchmark quality solutions in infinite media, half-space in one and two dimensions and in homogeneous slabs. This paper extends the set of solutions to include heterogeneous slab geometry by using the recently established Green's Function Method (GFM). Analytical benchmark solutions are an essential part of the quality control of computational algorithms developed for particle transport. In addition, benchmarking methods have applications in the classroom by providing examples of how computational mathematics is used to solve physical problems to obtain meaningful answers. In a structural context, monoenergetic solutions are directly applicable to the investigation of the microlight environment within a leaf. The leaf is considered to be a composition of alternating layers of highly absorbing pigments and water superimposed on a refractively scattering background

Solution of neutron slowing down equation including multiple inelastic scattering

International Nuclear Information System (INIS)

El-Wakil, S.A.; Saad, A.E.

1977-01-01

The present work is devoted the presentation of an analytical method for the calculation of elastically and inelastically slowed down neutrons in an infinite non absorbing homogeneous medium. On the basis of the Central limit theory (CLT) and the integral transform technique the slowing down equation including inelastic scattering in terms of the Green function of elastic scattering is solved. The Green function is decomposed according to the number of collisions. A formula for the flux at any lethargy O (u) after any number of collisions is derived. An equation for the asymptotic flux is also obtained

Incorporation of charge transfer into the explicit polarization fragment method by grand canonical density functional theory.

Science.gov (United States)

Isegawa, Miho; Gao, Jiali; Truhlar, Donald G

2011-08-28

Molecular fragmentation algorithms provide a powerful approach to extending electronic structure methods to very large systems. Here we present a method for including charge transfer between molecular fragments in the explicit polarization (X-Pol) fragment method for calculating potential energy surfaces. In the conventional X-Pol method, the total charge of each fragment is preserved, and charge transfer between fragments is not allowed. The description of charge transfer is made possible by treating each fragment as an open system with respect to the number of electrons. To achieve this, we applied Mermin's finite temperature method to the X-Pol wave function. In the application of this method to X-Pol, the fragments are open systems that partially equilibrate their number of electrons through a quasithermodynamics electron reservoir. The number of electrons in a given fragment can take a fractional value, and the electrons of each fragment obey the Fermi-Dirac distribution. The equilibrium state for the electrons is determined by electronegativity equalization with conservation of the total number of electrons. The amount of charge transfer is controlled by re-interpreting the temperature parameter in the Fermi-Dirac distribution function as a coupling strength parameter. We determined this coupling parameter so as to reproduce the charge transfer energy obtained by block localized energy decomposition analysis. We apply the new method to ten systems, and we show that it can yield reasonable approximations to potential energy profiles, to charge transfer stabilization energies, and to the direction and amount of charge transferred. © 2011 American Institute of Physics

A functional-analytic method for the study of difference equations

Directory of Open Access Journals (Sweden)

Siafarikas Panayiotis D

2004-01-01

Full Text Available We will give the generalization of a recently developed functional-analytic method for studying linear and nonlinear, ordinary and partial, difference equations in the and spaces, p∈ℕ, . The method will be illustrated by use of two examples concerning a nonlinear ordinary difference equation known as the Putnam equation, and a linear partial difference equation of three variables describing the discrete Newton law of cooling in three dimensions.

Application of Wave Distribution Function Method to the ERG/PWE Data

Science.gov (United States)

Ota, M.; Kasahara, Y.; Matsuda, S.; Kojima, H.; Matsuoka, A.; Hikishima, M.; Kasaba, Y.; Ozaki, M.; Yagitani, S.; Tsuchiya, F.; Kumamoto, A.

2017-12-01

The ERG (Arase) satellite was launched on 20 December 2016 to study acceleration and loss mechanisms of relativistic electrons in the Earth's magnetosphere. The Plasma Wave Experiment (PWE), which is one of the science instruments on board the ERG satellite, measures electric field and magnetic field. The PWE consists of three sub-systems; EFD (Electric Field Detector), OFA/WFC (Onboard Frequency Analyzer and Waveform Capture), and HFA (High Frequency Analyzer).The OFA/WFC measures electromagnetic field spectra and raw waveforms in the frequency range from few Hz to 20 kHz. The OFA produces three kind of data; OFA-SPEC (power spectrum), OFA-MATRIX (spectral matrix), and OFA-COMPLEX (complex spectrum). The OFA-MATRIX measures ensemble averaged complex cross-spectra of two electric field components, and of three magnetic field components. The OFA-COMPLEX measures instantaneous complex spectra of electric and magnetic fields. These data are produced every 8 seconds in the nominal mode, and it can be used for polarization analysis and wave propagation direction finding.In general, spectral matrix composed by cross-spectra of observed signals is used for direction finding, and many algorithms have been proposed. For example, Means method and SVD method can be applied on the assumption that the spectral matrix is consists of a single plane wave, while wave distribution function (WDF) method is applicable even to the data in which multiple numbers of plane waves are simultaneously included. In this presentation, we introduce the results when the WDF method is applied to the ERG/PWE data.

A Method of Function Space for Vertical Impedance Function of a Circular Rigid Foundation on a Transversely Isotropic Ground

Directory of Open Access Journals (Sweden)

Morteza Eskandari-Ghadi

2014-06-01

Full Text Available This paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semi-infinite transversely isotropic alluvium. To this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. The governing partial differential equation for the potential function is solved via implementing Hankel integral transforms in radial direction. The vertical and radial components of displacement vector are determined with the use of transformed displacement-potential function relationships. The mixed boundary conditions at the surface are satisfied by specifying the traction between the rigid foundation and the underneath alluvium in a special function space introduced in this paper, where the vertical displacements are forced to satisfy the rigid boundary condition. Through exercising these restraints, the normal traction and then the vertical impedance function are obtained. The results are then compared with the existing results in the literature for the simpler case of isotropic half-space, which shows an excellent agreement. Eventually, the impedance functions are presented in terms of dimensionless frequency for different materials. The method presented here may be used to obtain the impedance function in any other direction as well as in buried footing in layered media.

Application of numerical methods to the determination of molecular wave functions; Application de methodes de calcul numerique a la determination de fonctions d'onde moleculaires

Energy Technology Data Exchange (ETDEWEB)

Douady, Jerome

1969-10-01

A simplified SCF Method is developed. The wave function of molecular systems and spin densities in the case of free radicals are computed from geometrical data. This method, including at the beginning a delocalization of electrons over all the molecular system, two methods which clear out bonding and anti-bonding interactions have been studied and programmed: a) overlap population analysis, b) localisation of molecular orbitals. These methods have been carried out in the case of organic compounds and free radicals. (author) [French] Mise en oeuvre d'une methode de champ self-consistant simplifie qui, a partir des donnees geometriques, permet de calculer la fonction d'onde des systemes moleculaires et les densites de spin dans le cas des radicaux libres. Cette methode introduisant au depart une delocalisation des electrons sur tout le systeme moleculaire, deux methodes permettant de rendre compte du caractere liant et antiliant de ces electrons ont ete etudiees et programmees: a) analyse des populations de recouvrement, b) localisation des orbitales moleculaires. Ces methodes ont ete appliquees a divers composes organiques radicalaires et non radicalaires. (auteur)

An impedance function approach for soil-structure interaction analyses including structure-to-structure interaction effects

International Nuclear Information System (INIS)

Gantayat, A.; Kamil, H.

1981-01-01

The dynamic soil-structure and structure-to-structure interaction effects may be determined in one of the two ways: by modeling the entire soil-structure system by a finite-element model, or by using a frequency-dependent (or frequency-independent) impedance function approach. In seismic design of nuclear power plant structures, the normal practice is to use the first approach because of its simplicity and easy availability of computer codes to perform such analyses. However, in the finite-element approach, because of the size and cost restrictions, the three-dimensional behavior of the entire soil-structure system and the radiation damping in soil are only approximately included by using a two-dimensional finite-element mesh. In using the impedance function approach, the soil-structure analyses can be performed in four steps: (a) determination of the dynamic properties of the fixed base superstructure, (b) determination of foundation and structure impedance matrices and input motions, (c) evaluation of foundation motion, (d) analysis of the fixed base superstructure using computed foundation motion. (orig./RW)

Dhage Iteration Method for Generalized Quadratic Functional Integral Equations

Directory of Open Access Journals (Sweden)

Bapurao C. Dhage

2015-01-01

Full Text Available In this paper we prove the existence as well as approximations of the solutions for a certain nonlinear generalized quadratic functional integral equation. An algorithm for the solutions is developed and it is shown that the sequence of successive approximations starting at a lower or upper solution converges monotonically to the solutions of related quadratic functional integral equation under some suitable mixed hybrid conditions. We rely our main result on Dhage iteration method embodied in a recent hybrid fixed point theorem of Dhage (2014 in partially ordered normed linear spaces. An example is also provided to illustrate the abstract theory developed in the paper.

11C-methionine PET, a novel method for measuring regional salivary gland function after radiotherapy of head and neck cancer

International Nuclear Information System (INIS)

Buus, Simon; Grau, Cai; Munk, Ole Lajord; Bender, Dirk; Jensen, Kenneth; Keiding, Susanne

2004-01-01

Background and purpose: Loss of salivary gland function is a distressing side-effect of radiotherapy (RT) for head and neck cancer. The aim of this study was to develop a positron emission tomography (PET) method for measuring regional salivary gland function in the major salivary glands irradiated during RT. Patients and methods: Eight head and neck cancer patients were included; two were examined before RT and six after parotid sparing RT. Patients were examined by dynamic 11 C-methionine PET of the major salivary glands and parotid gland salivary flow measurements. PET data were analysed using a kinetic model of salivary gland 11 C-methionine metabolism, in which salivary gland function was quantified by the net metabolic clearance of 11 C-methionine, K. Functional voxel-wise images of K were calculated and matched with the CT-dose-plan for comparing regional salivary gland function with the regional radiation dose. Results: Parotid gland K correlated positively with parotid gland salivary flow, indicating that K can be used as an index of salivary gland function. K of parotid and submandibular glands was reduced dependent on the median radiation dose. In one patient, receiving a heterogeneous radiation dose to the parotid glands, regional salivary gland function was inversely correlated to the regional radiation dose. Conclusions: Salivary gland function can be measured by dynamic 11 C-methionine PET. The net metabolic clearance of 11 C-methionine of salivary glands was reduced dependent on the radiation dose. Dynamic 11 C-methionine PET offers a method for studying the individual response of the major salivary glands to irradiation

The Halden Reactor Project workshop meeting on human centred automation and function allocation methods

International Nuclear Information System (INIS)

Sebok, Angelia; Green, Marit; Larsen, Marit; Miberg, Ann Britt; Morisseau, Dolores

1998-02-01

A workshop on Human Centred Automation (HCA) and Function Allocation Methods was organised in Halden, September 29-30, 1997. The purpose of the workshop was to discuss and make recommendations on requirements for the Halden Project research agenda. The workshop meeting began with several presentations summarising current issues in HCA, Function Allocation Methods and Functional Modelling. Invited speakers presented their research or modelling efforts. Following the presentations, the workshop was divided into three working groups, all tasked with answering the same four questions: (1) What are the most important issues in Human Centred Automation? (2) Which strengths could be achieved by integrating Functional Modelling Methods into experimental Human Centred Automation research? (3) How should analytical and experimental methods be balanced? (4) What are the most important aspects in automation design methodology? Each group discussed the questions and produced specific recommendations that were summarised by the group's facilitator in a joint session of the workshop. (author)

An extended diffraction tomography method for quantifying structural damage using numerical Green's functions.

Science.gov (United States)

Chan, Eugene; Rose, L R Francis; Wang, Chun H

2015-05-01

Existing damage imaging algorithms for detecting and quantifying structural defects, particularly those based on diffraction tomography, assume far-field conditions for the scattered field data. This paper presents a major extension of diffraction tomography that can overcome this limitation and utilises a near-field multi-static data matrix as the input data. This new algorithm, which employs numerical solutions of the dynamic Green's functions, makes it possible to quantitatively image laminar damage even in complex structures for which the dynamic Green's functions are not available analytically. To validate this new method, the numerical Green's functions and the multi-static data matrix for laminar damage in flat and stiffened isotropic plates are first determined using finite element models. Next, these results are time-gated to remove boundary reflections, followed by discrete Fourier transform to obtain the amplitude and phase information for both the baseline (damage-free) and the scattered wave fields. Using these computationally generated results and experimental verification, it is shown that the new imaging algorithm is capable of accurately determining the damage geometry, size and severity for a variety of damage sizes and shapes, including multi-site damage. Some aspects of minimal sensors requirement pertinent to image quality and practical implementation are also briefly discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Methods of geometric function theory in classical and modern problems for polynomials

International Nuclear Information System (INIS)

Dubinin, Vladimir N

2012-01-01

This paper gives a survey of classical and modern theorems on polynomials, proved using methods of geometric function theory. Most of the paper is devoted to results of the author and his students, established by applying majorization principles for holomorphic functions, the theory of univalent functions, the theory of capacities, and symmetrization. Auxiliary results and the proofs of some of the theorems are presented. Bibliography: 124 titles.

A new diffusion nodal method based on analytic basis function expansion

International Nuclear Information System (INIS)

Noh, J.M.; Cho, N.Z.

1993-01-01

The transverse integration procedure commonly used in most advanced nodal methods results in some limitations. The first is that the transverse leakage term that appears in the transverse integration procedure must be appropriately approximated. In most advanced nodal methods, this term is expanded in a quadratic polynomial. The second arises when reconstructing the pinwise flux distribution within a node. The available one-dimensional flux shapes from nodal calculation in each spatial direction cannot be used directly in the flux reconstruction. Finally, the transverse leakage defined for a hexagonal node becomes so complicated as not to be easily handled and contains nonphysical singular terms. In this paper, a new nodal method called the analytic function expansion nodal (AFEN) method is described for both the rectangular geometry and the hexagonal geometry in order to overcome these limitations. This method does not solve the transverse-integrated one-dimensional diffusion equations but instead solves directly the original multidimensional diffusion equation within a node. This is a accomplished by expanding the solution (or the intranodal homogeneous flux distribution) in terms of nonseparable analytic basis functions satisfying the diffusion equation at any point in the node

A Method for the Measurement of Salivary Gland Function in Mice.

Science.gov (United States)

Bagavant, Harini; Trzeciak, Marta; Papinska, Joanna; Biswas, Indranil; Dunkleberger, Micah L; Sosnowska, Anna; Deshmukh, Umesh S

2018-01-25

Patients with Sjögren's syndrome, an autoimmune disease affecting the exocrine glands, develop salivary gland inflammation and have reduced saliva production. Similarly, saliva production is severely compromised in patients receiving radiation treatment for head and neck cancers. Rodent models, developed to mimic these clinical conditions, facilitate an understanding of the disease pathogenesis and allow for the development of new therapeutic strategies. Therefore, the ability to accurately, reproducibly, and repeatedly measure salivary gland function in animal models is critical. Building on procedures previously described in the literature, a method was developed that meets these criteria and was used to evaluate salivary gland function in mice. An additional advantage of this new method is that it is easily mastered, and has little inter-operator variation. Salivary gland function is evaluated as the amount (weight or volume) or rate (mL/min) of saliva produced in response to pilocarpine stimulation. The collected saliva is a good source for the analyses of protein content, immunoglobulin concentrations, and other biomolecules.

Modulation transfer function (MTF) measurement method based on support vector machine (SVM)

Science.gov (United States)

Zhang, Zheng; Chen, Yueting; Feng, Huajun; Xu, Zhihai; Li, Qi

2016-03-01

An imaging system's spatial quality can be expressed by the system's modulation spread function (MTF) as a function of spatial frequency in terms of the linear response theory. Methods have been proposed to assess the MTF of an imaging system using point, slit or edge techniques. The edge method is widely used for the low requirement of targets. However, the traditional edge methods are limited by the edge angle. Besides, image noise will impair the measurement accuracy, making the measurement result unstable. In this paper, a novel measurement method based on the support vector machine (SVM) is proposed. Image patches with different edge angles and MTF levels are generated as the training set. Parameters related with MTF and image structure are extracted from the edge images. Trained with image parameters and the corresponding MTF, the SVM classifier can assess the MTF of any edge image. The result shows that the proposed method has an excellent performance on measuring accuracy and stability.

A transformed rational function method and exact solutions to the 3+1 dimensional Jimbo-Miwa equation

International Nuclear Information System (INIS)

Ma Wenxiu; Lee, J.-H.

2009-01-01

A direct approach to exact solutions of nonlinear partial differential equations is proposed, by using rational function transformations. The new method provides a more systematical and convenient handling of the solution process of nonlinear equations, unifying the tanh-function type methods, the homogeneous balance method, the exp-function method, the mapping method, and the F-expansion type methods. Its key point is to search for rational solutions to variable-coefficient ordinary differential equations transformed from given partial differential equations. As an application, the construction problem of exact solutions to the 3+1 dimensional Jimbo-Miwa equation is treated, together with a Baecklund transformation.

Methods for Fabricating Gradient Alloy Articles with Multi-Functional Properties

Science.gov (United States)

Hofmann, Douglas C. (Inventor); Borgonia, John Paul C. (Inventor); Dillon, Robert P. (Inventor); Suh, Eric J. (Inventor); Mulder, Jerry L. (Inventor); Gardner, Paul B. (Inventor)

2015-01-01

Systems and methods for fabricating multi-functional articles comprised of additively formed gradient materials are provided. The fabrication of multi-functional articles using the additive deposition of gradient alloys represents a paradigm shift from the traditional way that metal alloys and metal/metal alloy parts are fabricated. Since a gradient alloy that transitions from one metal to a different metal cannot be fabricated through any conventional metallurgy techniques, the technique presents many applications. Moreover, the embodiments described identify a broad range of properties and applications.

Developing Mathematical Knowledge for Teaching in a Methods Course: The Case of Function

Science.gov (United States)

Steele, Michael D.; Hillen, Amy F.; Smith, Margaret S.

2013-01-01

This study describes teacher learning in a teaching experiment consisting of a content-focused methods course involving the mathematical knowledge for teaching function. Prospective and practicing teachers in the course showed growth in their ability to define function, to provide examples of functions and link them to the definition, in the…

A Modified Levenberg-Marquardt Method for Nonsmooth Equations with Finitely Many Maximum Functions

Directory of Open Access Journals (Sweden)

Shou-qiang Du

2008-01-01

Full Text Available For solving nonsmooth systems of equations, the Levenberg-Marquardt method and its variants are of particular importance because of their locally fast convergent rates. Finitely many maximum functions systems are very useful in the study of nonlinear complementarity problems, variational inequality problems, Karush-Kuhn-Tucker systems of nonlinear programming problems, and many problems in mechanics and engineering. In this paper, we present a modified Levenberg-Marquardt method for nonsmooth equations with finitely many maximum functions. Under mild assumptions, the present method is shown to be convergent Q-linearly. Some numerical results comparing the proposed method with classical reformulations indicate that the modified Levenberg-Marquardt algorithm works quite well in practice.

Generic primal-dual interior point methods based on a new kernel function

NARCIS (Netherlands)

EL Ghami, M.; Roos, C.

2008-01-01

In this paper we present a generic primal-dual interior point methods (IPMs) for linear optimization in which the search direction depends on a univariate kernel function which is also used as proximity measure in the analysis of the algorithm. The proposed kernel function does not satisfy all the

FSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Guidance on the scientific requirements for health claims related to functions of the ne rvous system, including psycholog ical functions

DEFF Research Database (Denmark)

Tetens, Inge

The European Food Safety Authority (EFSA) asked the Panel on Dietetic Products, Nutrition and Allergies to draft guidance on scientific requirements for health claims related to functions of the nervous system, including psychological functions. This guidance has been drawn from scientific opinions......, and was released for public consultation from 17 October 2011 to 16 December 2011....

Band extension in digital methods of transfer function determination – signal conditioners asymmetry error corrections

Directory of Open Access Journals (Sweden)

Zbigniew Staroszczyk

2014-12-01

Full Text Available [b]Abstract[/b]. In the paper, the calibrating method for error correction in transfer function determination with the use of DSP has been proposed. The correction limits/eliminates influence of transfer function input/output signal conditioners on the estimated transfer functions in the investigated object. The method exploits frequency domain conditioning paths descriptor found during training observation made on the known reference object.[b]Keywords[/b]: transfer function, band extension, error correction, phase errors

Solving two-dimensions heat conduction problem for fuel elements in reactor by nodal green's function method

International Nuclear Information System (INIS)

Tang Jian; Peng Muzhang; Cao Dongxing

1989-01-01

A new numerical method-nodal green's function method is used for solving heat conduction function. A heat conduction problem in cylindrical geometry with axial conduction is solved in this paper. The Kirchhoff transformation is used to deal with the problem with temperature dependent conductivity. Therefor, the calculation for the function is simplified. On the basis of the formulas developed, the code named NGMEFC is programmed. A sample problem which has been calculated by the code COBRA-IV is chosen as checking. A good agreement between both codes is achieved. The calculation shows that the calculation efficiency of the nodel green's function method is much higher than that of finite difference method

Fabrication of Al/Diamond Particles Functionally Graded Materials by Centrifugal Sintered-Casting Method

International Nuclear Information System (INIS)

Watanabe, Yoshimi; Shibuya, Masafumi; Sato, Hisashi

2013-01-01

The continuous graded structure of functionally graded materials (FGMs) can be created under a centrifugal force. Centrifugal sintered-casting (CSC) method, proposed by the authors, is one of the fabrication methods of FGM under centrifugal force. This method is a combination of the centrifugal sintering method and centrifugal casting method. In this study, Al/diamond particle FGM was fabricated by the proposed method.

Obtention of the parameters of the Voigt function using the least square fit method

International Nuclear Information System (INIS)

Flores Ll, H.; Cabral P, A.; Jimenez D, H.

1990-01-01

The fundamental parameters of the Voigt function are determined: lorentzian wide (Γ L ) and gaussian wide (Γ G ) with an error for almost all the cases inferior to 1% in the intervals 0.01 ≤ Γ L / Γ G ≤1 and 0.3 ≤ Γ G / Γ L ≤1. This is achieved using the least square fit method with an algebraic function, being obtained a simple method to obtain the fundamental parameters of the Voigt function used in many spectroscopies. (Author)

Defining the breeding goal for a sheep breed including production and functional traits using market data.

Science.gov (United States)

Theodoridis, A; Ragkos, A; Rose, G; Roustemis, D; Arsenos, G

2017-11-16

In this study, the economic values for production and functional traits of dairy sheep are estimated through the application of a profit function model using farm-level technical and economic data. The traits incorporated in the model were milk production, prolificacy, fertility, milking speed, longevity and mastitis occurrence. The economic values for these traits were derived as the approximate partial derivative of the specified profit function. A sensitivity analysis was also conducted in order to examine how potential changes in input and output prices would affect the breeding goal. The estimated economic values of the traits revealed their economic impact on the definition of the breeding goal for the specified production system. Milk production and fertility had the highest economic values (€40.30 and €20.28 per standard genetic deviation (SDa)), while, mastitis only had a low negative value of -0.57 €/SDa. Therefore, breeding for clinical mastitis will have a minor impact on farm profitability because it affects a small proportion of the flock and has low additive variance. The production traits, which include milk production, prolificacy and milking speed, contributed most to the breeding goal (70.0%), but functional traits still had a considerable share (30.0%). The results of this study highlight the importance of the knowledge of economic values of traits in the design of a breeding program. It is also suggested that the production and functional traits under consideration can be categorized as those which can be efficiently treated through genetic improvement (e.g. milk production and fertility) while others would be better dealt with through managerial interventions (e.g. mastitis occurrence). Also, sub-clinical mastitis that affects a higher proportion of flocks could have a higher contribution to breeding goals.

A review of Green's function methods in computational fluid mechanics: Background, recent developments and future directions

International Nuclear Information System (INIS)

Dorning, J.

1981-01-01

The research and development over the past eight years on local Green's function methods for the high-accuracy, high-efficiency numerical solution of nuclear engineering problems is reviewed. The basic concepts and key ideas are presented by starting with an expository review of the original fully two-dimensional local Green's function methods developed for neutron diffusion and heat conduction, and continuing through the progressively more complicated and more efficient nodal Green's function methods for neutron diffusion, heat conduction and neutron transport to establish the background for the recent development of Green's function methods in computational fluid mechanics. Some of the impressive numerical results obtained via these classes of methods for nuclear engineering problems are briefly summarized. Finally, speculations are proffered on future directions in which the development of these types of methods in fluid mechanics and other areas might lead. (orig.) [de

Renormalization Group Functional Equations

CERN Document Server

Curtright, Thomas L

2011-01-01

Functional conjugation methods are used to analyze the global structure of various renormalization group trajectories. With minimal assumptions, the methods produce continuous flows from step-scaling {\\sigma} functions, and lead to exact functional relations for the local flow {\\beta} functions, whose solutions may have novel, exotic features, including multiple branches. As a result, fixed points of {\\sigma} are sometimes not true fixed points under continuous changes in scale, and zeroes of {\\beta} do not necessarily signal fixed points of the flow, but instead may only indicate turning points of the trajectories.

The derivation of the Doppler broadening function using Frobenius method

International Nuclear Information System (INIS)

Palma, Daniel A.P.; Martinez, Aquilino S.; Silva, Fernando C.

2006-01-01

An analytical approximation of the Doppler broadening function ψ(ξ,x) is proposed. This approximation is based on the solution of the differential equation for ψ(ξ,x) using the methods of Frobenius and parameters variation. The analytical form derived for ψ(ξ,x) in terms of elementary functions is very simple and precise. It can be useful for applications related to the treatment of nuclear resonances, mainly for calculations of multigroup parameters and resonances self-protection factors, the latter being used to correct microscopic cross section measurements by the activation technique. (author)

Bootstrapping conformal field theories with the extremal functional method.

Science.gov (United States)

El-Showk, Sheer; Paulos, Miguel F

2013-12-13

The existence of a positive linear functional acting on the space of (differences between) conformal blocks has been shown to rule out regions in the parameter space of conformal field theories (CFTs). We argue that at the boundary of the allowed region the extremal functional contains, in principle, enough information to determine the dimensions and operator product expansion (OPE) coefficients of an infinite number of operators appearing in the correlator under analysis. Based on this idea we develop the extremal functional method (EFM), a numerical procedure for deriving the spectrum and OPE coefficients of CFTs lying on the boundary (of solution space). We test the EFM by using it to rederive the low lying spectrum and OPE coefficients of the two-dimensional Ising model based solely on the dimension of a single scalar quasiprimary--no Virasoro algebra required. Our work serves as a benchmark for applications to more interesting, less known CFTs in the near future.

Method of fabricating electrodes including high-capacity, binder-free anodes for lithium-ion batteries

Science.gov (United States)

Ban, Chunmei; Wu, Zhuangchun; Dillon, Anne C.

2017-01-10

An electrode (110) is provided that may be used in an electrochemical device (100) such as an energy storage/discharge device, e.g., a lithium-ion battery, or an electrochromic device, e.g., a smart window. Hydrothermal techniques and vacuum filtration methods were applied to fabricate the electrode (110). The electrode (110) includes an active portion (140) that is made up of electrochemically active nanoparticles, with one embodiment utilizing 3d-transition metal oxides to provide the electrochemical capacity of the electrode (110). The active material (140) may include other electrochemical materials, such as silicon, tin, lithium manganese oxide, and lithium iron phosphate. The electrode (110) also includes a matrix or net (170) of electrically conductive nanomaterial that acts to connect and/or bind the active nanoparticles (140) such that no binder material is required in the electrode (110), which allows more active materials (140) to be included to improve energy density and other desirable characteristics of the electrode. The matrix material (170) may take the form of carbon nanotubes, such as single-wall, double-wall, and/or multi-wall nanotubes, and be provided as about 2 to 30 percent weight of the electrode (110) with the rest being the active material (140).

New exact solutions of the Tzitzéica-type equations in non-linear optics using the expa function method

Science.gov (United States)

Hosseini, K.; Ayati, Z.; Ansari, R.

2018-04-01

One specific class of non-linear evolution equations, known as the Tzitzéica-type equations, has received great attention from a group of researchers involved in non-linear science. In this article, new exact solutions of the Tzitzéica-type equations arising in non-linear optics, including the Tzitzéica, Dodd-Bullough-Mikhailov and Tzitzéica-Dodd-Bullough equations, are obtained using the expa function method. The integration technique actually suggests a useful and reliable method to extract new exact solutions of a wide range of non-linear evolution equations.

Comparison of the functionality of pelvic floor muscles in women who practice the Pilates method and sedentary women: a pilot study.

Science.gov (United States)

Ferla, Lia; Paiva, Luciana Laureano; Darki, Caroline; Vieira, Adriane

2016-01-01

The Pilates method is a form of physical exercise that improves the control of the core muscles, improving the conditioning of all the muscle groups that comprise the core, including the pelvic floor muscles (PFM). Thus, this study had the goal of verifying the existence of differences in the functioning of the PFM in women who practice the Pilates method and sedentary women. This was an observational, cross-sectional pilot study. A sample size calculation was performed using preliminary data and it determined that the sample should have at least 24 individuals in each group. The participants were 60 women aged 20 to 40 years; 30 women practiced the Pilates method (PMG) and 30 were sedentary (SG). An anamnesis file was used to collect personal data and assess the knowledge and perception of the PFM. The Perina perineometer and vaginal palpation were used to determine the functionality of the PFM. There was no significant difference between the PMG and the SG in any of the variables analyzed. We concluded that the functionality of the PFM in younger women who practice the Pilates method is not different from that of sedentary women.

Coping with the node problem in quantum hydrodynamics: The covering function method

International Nuclear Information System (INIS)

Babyuk, Dmytro; Wyatt, Robert E.

2004-01-01

A conceptually simple approach, the covering function method (CFM), is developed to cope with the node problem in the hydrodynamic formulation of quantum mechanics. As nodes begin to form in a scattering wave packet (detected by a monitor function), a nodeless covering wave function is added to it yielding a total function that is also nodeless. Both local and global choices for the covering function are described. The total and covering functions are then propagated separately in the hydrodynamic picture. At a later time, the actual wave function is recovered from the two propagated functions. The results obtained for Eckart barrier scattering in one dimension are in excellent agreement with exact results, even for very long propagation times t=1.2 ps. The capability of the CFM is also demonstrated for multidimensional propagation of a vibrationally excited wave packet

Time-dependent density functional theory (TD-DFT) coupled with reference interaction site model self-consistent field explicitly including spatial electron density distribution (RISM-SCF-SEDD)

Energy Technology Data Exchange (ETDEWEB)

Yokogawa, D., E-mail: d.yokogawa@chem.nagoya-u.ac.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

2016-09-07

Theoretical approach to design bright bio-imaging molecules is one of the most progressing ones. However, because of the system size and computational accuracy, the number of theoretical studies is limited to our knowledge. To overcome the difficulties, we developed a new method based on reference interaction site model self-consistent field explicitly including spatial electron density distribution and time-dependent density functional theory. We applied it to the calculation of indole and 5-cyanoindole at ground and excited states in gas and solution phases. The changes in the optimized geometries were clearly explained with resonance structures and the Stokes shift was correctly reproduced.

Finite-time generalized function matrix projective lag synchronization of coupled dynamical networks with different dimensions via the double power function nonlinear feedback control method

International Nuclear Information System (INIS)

Dai, Hao; Si, Gangquan; Jia, Lixin; Zhang, Yanbin

2014-01-01

This paper investigates the problem of finite-time generalized function matrix projective lag synchronization between two different coupled dynamical networks with different dimensions of network nodes. The double power function nonlinear feedback control method is proposed in this paper to guarantee that the state trajectories of the response network converge to the state trajectories of the drive network according to a function matrix in a given finite time. Furthermore, in comparison with the traditional nonlinear feedback control method, the new method improves the synchronization efficiency, and shortens the finite synchronization time. Numerical simulation results are presented to illustrate the effectiveness of this method. (papers)

A Sequential Optimization Sampling Method for Metamodels with Radial Basis Functions

Science.gov (United States)

Pan, Guang; Ye, Pengcheng; Yang, Zhidong

2014-01-01

Metamodels have been widely used in engineering design to facilitate analysis and optimization of complex systems that involve computationally expensive simulation programs. The accuracy of metamodels is strongly affected by the sampling methods. In this paper, a new sequential optimization sampling method is proposed. Based on the new sampling method, metamodels can be constructed repeatedly through the addition of sampling points, namely, extrema points of metamodels and minimum points of density function. Afterwards, the more accurate metamodels would be constructed by the procedure above. The validity and effectiveness of proposed sampling method are examined by studying typical numerical examples. PMID:25133206

A method for the direct generation of comprehensive numerical solar building transfer functions

Energy Technology Data Exchange (ETDEWEB)

Chen, T.Y. [The Hong Kong Polytechnic University (China). Dept. of Building Services Engineering

2003-02-01

This paper describes a method for the direct generation of comprehensive numerical room transfer functions with any derived parameters as output, such as operative temperature or thermal load. Complex conductive, convective and radiant heat transfer processes, or any derived thermal parameters in buildings can be explicitly and precisely described by a generalized thermal network. This allows the s-transfer and z-transfer functions to be directly generated, using semi-symbolic analysis techniques, Cayley's expansion of determinant and Heaviside's expansion theorem. A simple algorithm is developed for finding the roots of the denominator in the inverse transform of the s-transfer functions, which ensures that no single root is missing. The techniques have been applied to generating the transfer functions of a passive solar room with floor heating. The example calculation demonstrates the high efficiency of the computational method. (author)

Functionality of system components: Conservation of protein function in protein feature space

DEFF Research Database (Denmark)

Jensen, Lars Juhl; Ussery, David; Brunak, Søren

2003-01-01

well on organisms other than the one on which it was trained. We evaluate the performance of such a method, ProtFun, which relies on protein features as its sole input, and show that the method gives similar performance for most eukaryotes and performs much better than anticipated on archaea......Many protein features useful for prediction of protein function can be predicted from sequence, including posttranslational modifications, subcellular localization, and physical/chemical properties. We show here that such protein features are more conserved among orthologs than paralogs, indicating...... they are crucial for protein function and thus subject to selective pressure. This means that a function prediction method based on sequence-derived features may be able to discriminate between proteins with different function even when they have highly similar structure. Also, such a method is likely to perform...

Generation of Functional Cardiomyocytes from Efficiently Generated Human iPSCs and a Novel Method of Measuring Contractility.

Directory of Open Access Journals (Sweden)

Sheeja Rajasingh

Full Text Available Human induced pluripotent stem cells (iPSCs derived cardiomyocytes (iCMCs would provide an unlimited cell source for regenerative medicine and drug discoveries. The objective of our study is to generate functional cardiomyocytes from human iPSCs and to develop a novel method of measuring contractility of CMCs. In a series of experiments, adult human skin fibroblasts (HSF and human umbilical vein endothelial cells (HUVECs were treated with a combination of pluripotent gene DNA and mRNA under specific conditions. The iPSC colonies were identified and differentiated into various cell lineages, including CMCs. The contractile activity of CMCs was measured by a novel method of frame-by-frame cross correlation (particle image velocimetry-PIV analysis. Our treatment regimen transformed 4% of HSFs into iPSC colonies at passage 0, a significantly improved efficiency compared with use of either DNA or mRNA alone. The iPSCs were capable of differentiating both in vitro and in vivo into endodermal, ectodermal and mesodermal cells, including CMCs with >88% of cells being positive for troponin T (CTT and Gata4 by flow cytometry. We report a highly efficient combination of DNA and mRNA to generate iPSCs and functional iCMCs from adult human cells. We also report a novel approach to measure contractility of iCMCs.

Generation of Functional Cardiomyocytes from Efficiently Generated Human iPSCs and a Novel Method of Measuring Contractility.

Science.gov (United States)

Rajasingh, Sheeja; Thangavel, Jayakumar; Czirok, Andras; Samanta, Saheli; Roby, Katherine F; Dawn, Buddhadeb; Rajasingh, Johnson

2015-01-01

Human induced pluripotent stem cells (iPSCs) derived cardiomyocytes (iCMCs) would provide an unlimited cell source for regenerative medicine and drug discoveries. The objective of our study is to generate functional cardiomyocytes from human iPSCs and to develop a novel method of measuring contractility of CMCs. In a series of experiments, adult human skin fibroblasts (HSF) and human umbilical vein endothelial cells (HUVECs) were treated with a combination of pluripotent gene DNA and mRNA under specific conditions. The iPSC colonies were identified and differentiated into various cell lineages, including CMCs. The contractile activity of CMCs was measured by a novel method of frame-by-frame cross correlation (particle image velocimetry-PIV) analysis. Our treatment regimen transformed 4% of HSFs into iPSC colonies at passage 0, a significantly improved efficiency compared with use of either DNA or mRNA alone. The iPSCs were capable of differentiating both in vitro and in vivo into endodermal, ectodermal and mesodermal cells, including CMCs with >88% of cells being positive for troponin T (CTT) and Gata4 by flow cytometry. We report a highly efficient combination of DNA and mRNA to generate iPSCs and functional iCMCs from adult human cells. We also report a novel approach to measure contractility of iCMCs.

Solving one-dimensional phase change problems with moving grid method and mesh free radial basis functions

International Nuclear Information System (INIS)

Vrankar, L.; Turk, G.; Runovc, F.; Kansa, E.J.

2006-01-01

Many heat-transfer problems involve a change of phase of material due to solidification or melting. Applications include: the safety studies of nuclear reactors (molten core concrete interaction), the drilling of high ice-content soil, the storage of thermal energy, etc. These problems are often called Stefan's or moving boundary value problems. Mathematically, the interface motion is expressed implicitly in an equation for the conservation of thermal energy at the interface (Stefan's conditions). This introduces a non-linear character to the system which treats each problem somewhat uniquely. The exact solution of phase change problems is limited exclusively to the cases in which e.g. the heat transfer regions are infinite or semi-infinite one dimensional-space. Therefore, solution is obtained either by approximate analytical solution or by numerical methods. Finite-difference methods and finite-element techniques have been used extensively for numerical solution of moving boundary problems. Recently, the numerical methods have focused on the idea of using a mesh-free methodology for the numerical solution of partial differential equations based on radial basis functions. In our case we will study solid-solid transformation. The numerical solutions will be compared with analytical solutions. Actually, in our work we will examine usefulness of radial basis functions (especially multiquadric-MQ) for one-dimensional Stefan's problems. The position of the moving boundary will be simulated by moving grid method. The resultant system of RBF-PDE will be solved by affine space decomposition. (author)

Proposals for Iterated Hash Functions

DEFF Research Database (Denmark)

Knudsen, Lars Ramkilde; Thomsen, Søren Steffen

2008-01-01

The past few years have seen an increase in the number of attacks on cryptographic hash functions. These include attacks directed at specific hash functions, and generic attacks on the typical method of constructing hash functions. In this paper we discuss possible methods for protecting against...... some generic attacks. We also give a concrete proposal for a new hash function construction, given a secure compression function which, unlike in typical existing constructions, is not required to be resistant to all types of collisions. Finally, we show how members of the SHA-family can be turned...

Proposals for iterated hash functions

DEFF Research Database (Denmark)

Knudsen, Lars Ramkilde; Thomsen, Søren Steffen

2006-01-01

The past few years have seen an increase in the number of attacks on cryptographic hash functions. These include attacks directed at specific hash functions, and generic attacks on the typical method of constructing hash functions. In this paper we discuss possible methods for protecting against...... some generic attacks. We also give a concrete proposal for a new hash function construction, given a secure compression function which, unlike in typical existing constructions, is not required to be resistant to all types of collisions. Finally, we show how members of the SHA-family can be turned...

A robust two-node, 13 moment quadrature method of moments for dilute particle flows including wall bouncing

Science.gov (United States)

Sun, Dan; Garmory, Andrew; Page, Gary J.

2017-02-01

For flows where the particle number density is low and the Stokes number is relatively high, as found when sand or ice is ingested into aircraft gas turbine engines, streams of particles can cross each other's path or bounce from a solid surface without being influenced by inter-particle collisions. The aim of this work is to develop an Eulerian method to simulate these types of flow. To this end, a two-node quadrature-based moment method using 13 moments is proposed. In the proposed algorithm thirteen moments of particle velocity, including cross-moments of second order, are used to determine the weights and abscissas of the two nodes and to set up the association between the velocity components in each node. Previous Quadrature Method of Moments (QMOM) algorithms either use more than two nodes, leading to increased computational expense, or are shown here to give incorrect results under some circumstances. This method gives the computational efficiency advantages of only needing two particle phase velocity fields whilst ensuring that a correct combination of weights and abscissas is returned for any arbitrary combination of particle trajectories without the need for any further assumptions. Particle crossing and wall bouncing with arbitrary combinations of angles are demonstrated using the method in a two-dimensional scheme. The ability of the scheme to include the presence of drag from a carrier phase is also demonstrated, as is bouncing off surfaces with inelastic collisions. The method is also applied to the Taylor-Green vortex flow test case and is found to give results superior to the existing two-node QMOM method and is in good agreement with results from Lagrangian modelling of this case.

Fixed Point Methods in the Stability of the Cauchy Functional Equations

Directory of Open Access Journals (Sweden)

Z. Dehvari

2013-03-01

Full Text Available By using the fixed point methods, we prove some generalized Hyers-Ulam stability of homomorphisms for Cauchy and CauchyJensen functional equations on the product algebras and on the triple systems.

The orthogonal gradients method: A radial basis functions method for solving partial differential equations on arbitrary surfaces

KAUST Repository

Piret, Cécile

2012-05-01

Much work has been done on reconstructing arbitrary surfaces using the radial basis function (RBF) method, but one can hardly find any work done on the use of RBFs to solve partial differential equations (PDEs) on arbitrary surfaces. In this paper, we investigate methods to solve PDEs on arbitrary stationary surfaces embedded in . R3 using the RBF method. We present three RBF-based methods that easily discretize surface differential operators. We take advantage of the meshfree character of RBFs, which give us a high accuracy and the flexibility to represent the most complex geometries in any dimension. Two out of the three methods, which we call the orthogonal gradients (OGr) methods are the result of our work and are hereby presented for the first time. © 2012 Elsevier Inc.

Assessment of soil microbial diversity with functional multi-endpoint methods

DEFF Research Database (Denmark)

Winding, Anne; Creamer, R. E.; Rutgers, M.

on CO2 development by the microbes such as substrate induced respiration (SIR) on specific substrates have lead to the development of MicroResp™ and Community Level Physiological Profile (CLPP) with Biolog™ plates, and soil enzymatic activity assayed by Extracellular Enzyme Activity (EEA) based on MUF......Soil microbial diversity provides the cornerstone for support of soil ecosystem services by key roles in soil organic matter turnover, carbon sequestration and water infiltration. However, standardized methods to quantify the multitude of microbial functions in soils are lacking. Methods based...... to the lack of principle methods, the data obtained from these substitute methods are currently not used in classification and assessment schemes, making quantification of natural capital and ecosystems services of the soil a difficult venture. In this contribution, we compare and contrast the three...

A nonlinear analytic function expansion nodal method for transient calculations

Energy Technology Data Exchange (ETDEWEB)

Joo, Han Gyn; Park, Sang Yoon; Cho, Byung Oh; Zee, Sung Quun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1999-12-31

The nonlinear analytic function expansion nodal (AFEN) method is applied to the solution of the time-dependent neutron diffusion equation. Since the AFEN method requires both the particular solution and the homogeneous solution to the transient fixed source problem, the derivation of the solution method is focused on finding the particular solution efficiently. To avoid complicated particular solutions, the source distribution is approximated by quadratic polynomials and the transient source is constructed such that the error due to the quadratic approximation is minimized, In addition, this paper presents a new two-node solution scheme that is derived by imposing the constraint of current continuity at the interface corner points. The method is verified through a series of application to the NEACRP PWR rod ejection benchmark problems. 6 refs., 2 figs., 1 tab. (Author)

A nonlinear analytic function expansion nodal method for transient calculations

Energy Technology Data Exchange (ETDEWEB)

Joo, Han Gyn; Park, Sang Yoon; Cho, Byung Oh; Zee, Sung Quun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

The nonlinear analytic function expansion nodal (AFEN) method is applied to the solution of the time-dependent neutron diffusion equation. Since the AFEN method requires both the particular solution and the homogeneous solution to the transient fixed source problem, the derivation of the solution method is focused on finding the particular solution efficiently. To avoid complicated particular solutions, the source distribution is approximated by quadratic polynomials and the transient source is constructed such that the error due to the quadratic approximation is minimized, In addition, this paper presents a new two-node solution scheme that is derived by imposing the constraint of current continuity at the interface corner points. The method is verified through a series of application to the NEACRP PWR rod ejection benchmark problems. 6 refs., 2 figs., 1 tab. (Author)

Apparatus and Method for Assessing Vestibulo-Ocular Function

Science.gov (United States)

Shelhamer, Mark J. (Inventor)

2015-01-01

A system for assessing vestibulo-ocular function includes a motion sensor system adapted to be coupled to a user's head; a data processing system configured to communicate with the motion sensor system to receive the head-motion signals; a visual display system configured to communicate with the data processing system to receive image signals from the data processing system; and a gain control device arranged to be operated by the user and to communicate gain adjustment signals to the data processing system.

Computational Methods and Function Theory

CERN Document Server

Saff, Edward; Salinas, Luis; Varga, Richard

1990-01-01

The volume is devoted to the interaction of modern scientific computation and classical function theory. Many problems in pure and more applied function theory can be tackled using modern computing facilities: numerically as well as in the sense of computer algebra. On the other hand, computer algorithms are often based on complex function theory, and dedicated research on their theoretical foundations can lead to great enhancements in performance. The contributions - original research articles, a survey and a collection of problems - cover a broad range of such problems.

Motor relearning program and Bobath method improve motor function of the upper extremities in patients with stroke

Institute of Scientific and Technical Information of China (English)

Jinjing Liu; Fengsheng Li; Guihua Liu

2006-01-01

BACKGROUND: In the natural evolution of cerebrovascular disease, unconscious use of affected extremity during drug treatment and daily life can improve the function of affected upper extremity partially, but it is very slow and alsc accompanied by the formation of abnormal mode. Therefore, functional training should be emphasized in recovering the motor function of extremity.OBJECTIVE: To observe the effects of combination of motor relearning program and Bobath method on motor function of upper extremity of patients with stroke.DESIGN: Comparison of therapeutic effects taking stroke patients as observation subjects.SETTING: Department of Neurology, General Hospital of Beijing Jingmei Group.PARTICIPANTS: Totally 120 stroke patients, including 60 males and 60 females, averaged (59±3) years, who hospitalized in the Department of Neurology, General Hospital of Beijing Jingmei Group between January 2005 and June 2006 were recruited. The involved patients met the following criteria: Stroke attack within 2 weeks;diagnosis criteria of cerebral hemorrhage or infarction made in the 4th National Cerebrovascular Disease Conference; confirmed by skull CT or MRI; Informed consents of therapeutic regimen were obtained. The patients were assigned into 2 groups according to their wills: rehabilitation group and control group, with 30 males and 30 females in each group. Patients in rehabilitation group averaged (59±2)years old, and those in the control group averaged (58±2)years old.METHODS: ① Patients in two groups received routine treatment in the Department of Neurology. When the vital signs of patients in the rehabilitation group were stable, individualized treatment was conducted by combined application of motor relearning program and Bobath method. Meanwhile, training of activity of daily living was performed according to the disease condition changes of patients at different phases, including the nursing and instruction of body posture, the maintenance of good extremity

Determination of acoustical transfer functions using an impulse method

Science.gov (United States)

MacPherson, J.

1985-02-01

The Transfer Function of a system may be defined as the relationship of the output response to the input of a system. Whilst recent advances in digital processing systems have enabled Impulse Transfer Functions to be determined by computation of the Fast Fourier Transform, there has been little work done in applying these techniques to room acoustics. Acoustical Transfer Functions have been determined for auditoria, using an impulse method. The technique is based on the computation of the Fast Fourier Transform (FFT) of a non-ideal impulsive source, both at the source and at the receiver point. The Impulse Transfer Function (ITF) is obtained by dividing the FFT at the receiver position by the FFT of the source. This quantity is presented both as linear frequency scale plots and also as synthesized one-third octave band data. The technique enables a considerable quantity of data to be obtained from a small number of impulsive signals recorded in the field, thereby minimizing the time and effort required on site. As the characteristics of the source are taken into account in the calculation, the choice of impulsive source is non-critical. The digital analysis equipment required for the analysis is readily available commercially.

Approximated calculation of the vacuum wave function and vacuum energy of the LGT with RPA method

International Nuclear Information System (INIS)

Hui Ping

2004-01-01

The coupled cluster method is improved with the random phase approximation (RPA) to calculate vacuum wave function and vacuum energy of 2 + 1 - D SU(2) lattice gauge theory. In this calculating, the trial wave function composes of single-hollow graphs. The calculated results of vacuum wave functions show very good scaling behaviors at weak coupling region l/g 2 >1.2 from the third order to the sixth order, and the vacuum energy obtained with RPA method is lower than the vacuum energy obtained without RPA method, which means that this method is a more efficient one

Green's function method for perturbed Korteweg-de Vries equation

International Nuclear Information System (INIS)

Cai Hao; Huang Nianning

2003-01-01

The x-derivatives of squared Jost solution are the eigenfunctions with the zero eigenvalue of the linearized equation derived from the perturbed Korteweg-de Vries equation. A method similar to Green's function formalism is introduced to show the completeness of the squared Jost solutions in multi-soliton cases. It is not related to Lax equations directly, and thus it is beneficial to deal with the nonlinear equations with complicated Lax pair

The cerebral blood flow measurement without absolute input function value for PET O-15 injection method

International Nuclear Information System (INIS)

Matsuda, Tadashige

2004-01-01

This paper shows the method of the measurement for the region of interest's (ROI's) cerebral blood flow (CBF) using PET data and the input function without the absolute density value of the radio activity. The value of the input function and the output function are fixed from the clinical data by regression analysis. The input function and the output function are transformed by the Fourier transform. The transfer function of the differential equation of the compartment model is got by these Fourier transforms. The CBF can be estimated by the transfer function regression analysis. Results are compared between the proposal and conventional methods. (author)

Preequilibrium decay models and the quantum Green function method

International Nuclear Information System (INIS)

Zhivopistsev, F.A.; Rzhevskij, E.S.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Teoreticheskoj i Ehksperimental'noj Fiziki)

1977-01-01

The nuclear process mechanism and preequilibrium decay involving complex particles are expounded on the basis of the Green function formalism without the weak interaction assumptions. The Green function method is generalized to a general nuclear reaction: A+α → B+β+γ+...rho, where A is the target nucleus, α is a complex particle in the initial state, B is the final nucleus, and β, γ, ... rho are nuclear fragments in the final state. The relationship between the generalized Green function and Ssub(fi)-matrix is established. The resultant equations account for: 1) direct and quasi-direct processes responsible for the angular distribution asymmetry of the preequilibrium component; 2) the appearance of addends corresponding to the excitation of complex states of final nucleus; and 3) the relationship between the preequilibrium decay model and the general models of nuclear reaction theories (Lippman-Schwinger formalism). The formulation of preequilibrium emission via the S(T) matrix allows to account for all the differential terms in succession important to an investigation of the angular distribution assymetry of emitted particles

The orthogonal gradients method: A radial basis functions method for solving partial differential equations on arbitrary surfaces

KAUST Repository

Piret, Cé cile

2012-01-01

Much work has been done on reconstructing arbitrary surfaces using the radial basis function (RBF) method, but one can hardly find any work done on the use of RBFs to solve partial differential equations (PDEs) on arbitrary surfaces. In this paper

Quantum Effect in a Diode Included Nonlinear Inductance-Capacitance Mesoscopic Circuit

International Nuclear Information System (INIS)

Yan Zhanyuan; Zhang Xiaohong; Ma Jinying

2009-01-01

The mesoscopic nonlinear inductance-capacitance circuit is a typical anharmonic oscillator, due to diodes included in the circuit. In this paper, using the advanced quantum theory of mesoscopic circuits, which based on the fundamental fact that the electric charge takes discrete value, the diode included mesoscopic circuit is firstly studied. Schroedinger equation of the system is a four-order difference equation in p-circumflex representation. Using the extended perturbative method, the detail energy spectrum and wave functions are obtained and verified, as an application of the results, the current quantum fluctuation in the ground state is calculated. Diode is a basis component in a circuit, its quantization would popularize the quantum theory of mesoscopic circuits. The methods to solve the high order difference equation are helpful to the application of mesoscopic quantum theory.

Method of the reduced-added Green function in the calculation of atomic polarizabilities

International Nuclear Information System (INIS)

Chernov, V.E.; Dorofeev, D.L.; Kretinin, I.Yu.; Zon, B.A.

2005-01-01

The Green function in the quantum defect theory provides an exact account for high-excited and continuum electronic states. We modify it by taking into account the ground and low-excited states using their wave functions calculated ab initio. As an application, we present a simple and efficient semianalytical method for the calculation of atomic electric frequency-dependent scalar dipole polarizability, for both real and imaginary frequencies. The polarizabilities calculated for some atoms (Li, Na, K, Be, Mg, Ca, Si, P, S, O, Al, Ge, C, N, F, He, Ne, Ar, Kr, and Xe) are compared with existing methods of computational quantum chemistry and with experiments; good accuracy of the proposed method is demonstrated

Researching Civil Remedies for International Corruption: The Choice of the Functional Comparative Method

NARCIS (Netherlands)

A.O. Makinwa (Abiola)

2009-01-01

textabstractThis paper motivates the choice of the functional comparative method to research the issue of civil remedies for international corruption. It shows how the social, economic and political factors that have shaped the normative context of the research question point to the functional

Test Functions for Three-Dimensional Control-Volume Mixed Finite-Element Methods on Irregular Grids

National Research Council Canada - National Science Library

Naff, R. L; Russell, T. F; Wilson, J. D

2000-01-01

.... For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error...

Symmetrized partial-wave method for density-functional cluster calculations

International Nuclear Information System (INIS)

Averill, F.W.; Painter, G.S.

1994-01-01

The computational advantage and accuracy of the Harris method is linked to the simplicity and adequacy of the reference-density model. In an earlier paper, we investigated one way the Harris functional could be extended to systems outside the limits of weakly interacting atoms by making the charge density of the interacting atoms self-consistent within the constraints of overlapping spherical atomic densities. In the present study, a method is presented for augmenting the interacting atom charge densities with symmetrized partial-wave expansions on each atomic site. The added variational freedom of the partial waves leads to a scheme capable of giving exact results within a given exchange-correlation approximation while maintaining many of the desirable convergence and stability properties of the original Harris method. Incorporation of the symmetry of the cluster in the partial-wave construction further reduces the level of computational effort. This partial-wave cluster method is illustrated by its application to the dimer C 2 , the hypothetical atomic cluster Fe 6 Al 8 , and the benzene molecule

Modulating functions method for parameters estimation in the fifth order KdV equation

KAUST Repository

Asiri, Sharefa M.; Liu, Da-Yan; Laleg-Kirati, Taous-Meriem

2017-01-01

In this work, the modulating functions method is proposed for estimating coefficients in higher-order nonlinear partial differential equation which is the fifth order Kortewegde Vries (KdV) equation. The proposed method transforms the problem into a

Improving the influence function method to take topography into the calculation of mining subsidence

OpenAIRE

Cai , Yinfei; Verdel , Thierry; Deck , Olivier; LI , Xiao-Jong

2016-01-01

International audience; The classic influence function method is often used in the calculation of mining subsidence caused by stratiform underground excavations. Theoretically,its use is limited to the subsidence predictions under the condition of horizontal ground surface. In order to improve the original influence function method to take topographic variations into account. Due to real-world mining conditions that are usually complicated, it is difficult to separate topography influences fr...

Nonequilibrium Green's function method for quantum thermal transport

Science.gov (United States)

Wang, Jian-Sheng; Agarwalla, Bijay Kumar; Li, Huanan; Thingna, Juzar

2014-12-01

This review deals with the nonequilibrium Green's function (NEGF) method applied to the problems of energy transport due to atomic vibrations (phonons), primarily for small junction systems. We present a pedagogical introduction to the subject, deriving some of the well-known results such as the Laudauer-like formula for heat current in ballistic systems. The main aim of the review is to build the machinery of the method so that it can be applied to other situations, which are not directly treated here. In addition to the above, we consider a number of applications of NEGF, not in routine model system calculations, but in a few new aspects showing the power and usefulness of the formalism. In particular, we discuss the problems of multiple leads, coupled left-right-lead system, and system without a center. We also apply the method to the problem of full counting statistics. In the case of nonlinear systems, we make general comments on the thermal expansion effect, phonon relaxation time, and a certain class of mean-field approximations. Lastly, we examine the relationship between NEGF, reduced density matrix, and master equation approaches to thermal transport.

Note on asymptotic series expansions for the derivative of the Hurwitz zeta function and related functions

International Nuclear Information System (INIS)

Rudaz, S.

1990-01-01

Asymptotic series for the Hurwitz zeta function, its derivative, and related functions (including the Riemann zeta function of odd integer argument) are derived as an illustration of a simple, direct method of broad applicability, inspired by the calculus of finite differences

Radionuclide method for functional and structural examination of the thyroid gland

International Nuclear Information System (INIS)

Mladenov, K.

2009-01-01

Full text: The aim of this study is development and routine daily practice of the radionuclide method for tracking of the thyroid gland functional status and structure. 168 patients with various thyroid diseases were examined. Nuclear medicine examination is held by gamma camera (Siemens and ADAK). 74 MBq 99m Tc-pertechnetate is injected intravenous. The activity of full and empty syringe is measured. Static scintigrams of full and empty syringes and injection place and duration 10 seconds are carried out. On 20 th minute a static scintigraphy of the thyroid gland with a duration of 300 seconds in front position is held. The individual dose calibration factor is calculated. The functional status of thyroid gland as well as its structural changes is determined. In addition, the relationships between the accumulation of radiopharmaceutical in the salivary glands and thyroid are determined. 168 patients are studied, 97 of them are with euthyroidism, 71 with hyperthyroidism and 19 - with hypothyroidism. The nuclear medicine diagnostic method provides information about functional and structural condition of the thyroid gland. The study is determining for decision to conduct the metabolic brachytherapy of hyperthyroid conditions

Exact solitary wave solutions for some nonlinear evolution equations via Exp-function method

International Nuclear Information System (INIS)

Ebaid, A.

2007-01-01

Based on the Exp-function method, exact solutions for some nonlinear evolution equations are obtained. The KdV equation, Burgers' equation and the combined KdV-mKdV equation are chosen to illustrate the effectiveness of the method

The Functions and Methods of Mental Training on Competitive Sports

Science.gov (United States)

Xiong, Jianshe

Mental training is the major training method of the competitive sports and the main factor of athletes skill and tactics level.By combining the psychological factor with the current competitive sports characteristics, this paper presents the function of mental training forward athletes, and how to improve the comprehensive psychological quality by using mental training.

Regularization of the Fourier series of discontinuous functions by various summation methods

Energy Technology Data Exchange (ETDEWEB)

Ahmad, S.S.; Beghi, L. (Padua Univ. (Italy). Seminario Matematico)

1983-07-01

In this paper the regularization by various summation methods of the Fourier series of functions containing discontinuities of the first and second kind are studied and the results of the numerical analyses referring to some typical periodic functions are presented. In addition to the Cesaro and Lanczos weightings, a new (i.e. cosine) weighting for accelerating the convergence rate is proposed. A comparison with the results obtained by Garibotti and Massaro with the punctual Pade approximants (PPA) technique in case of a periodic step function is also carried out.

Assessment of Ab Initio and Density Functional Theory Methods for the Excitations of Donor-Acceptor Complexes: The Case of the Benzene-Tetracyanoethylene Model

Directory of Open Access Journals (Sweden)

Peng Xu

2018-04-01

Full Text Available The understanding of the excited-state properties of electron donors, acceptors and their interfaces in organic optoelectronic devices is a fundamental issue for their performance optimization. In order to obtain a balanced description of the different excitation types for electron-donor-acceptor systems, including the singlet charge transfer (CT, local excitations, and triplet excited states, several ab initio and density functional theory (DFT methods for excited-state calculations were evaluated based upon the selected model system of benzene-tetracyanoethylene (B-TCNE complexes. On the basis of benchmark calculations of the equation-of-motion coupled-cluster with single and double excitations method, the arithmetic mean of the absolute errors and standard errors of the electronic excitation energies for the different computational methods suggest that the M11 functional in DFT is superior to the other tested DFT functionals, and time-dependent DFT (TDDFT with the Tamm–Dancoff approximation improves the accuracy of the calculated excitation energies relative to that of the full TDDFT. The performance of the M11 functional underlines the importance of kinetic energy density, spin-density gradient, and range separation in the development of novel DFT functionals. According to the TDDFT results, the performances of the different TDDFT methods on the CT properties of the B-TCNE complexes were also analyzed.

KEELE, Minimization of Nonlinear Function with Linear Constraints, Variable Metric Method

International Nuclear Information System (INIS)

Westley, G.W.

1975-01-01

1 - Description of problem or function: KEELE is a linearly constrained nonlinear programming algorithm for locating a local minimum of a function of n variables with the variables subject to linear equality and/or inequality constraints. 2 - Method of solution: A variable metric procedure is used where the direction of search at each iteration is obtained by multiplying the negative of the gradient vector by a positive definite matrix which approximates the inverse of the matrix of second partial derivatives associated with the function. 3 - Restrictions on the complexity of the problem: Array dimensions limit the number of variables to 20 and the number of constraints to 50. These can be changed by the user

Functional connectivity analysis of the neural bases of emotion regulation: A comparison of independent component method with density-based k-means clustering method.

Science.gov (United States)

Zou, Ling; Guo, Qian; Xu, Yi; Yang, Biao; Jiao, Zhuqing; Xiang, Jianbo

2016-04-29

Functional magnetic resonance imaging (fMRI) is an important tool in neuroscience for assessing connectivity and interactions between distant areas of the brain. To find and characterize the coherent patterns of brain activity as a means of identifying brain systems for the cognitive reappraisal of the emotion task, both density-based k-means clustering and independent component analysis (ICA) methods can be applied to characterize the interactions between brain regions involved in cognitive reappraisal of emotion. Our results reveal that compared with the ICA method, the density-based k-means clustering method provides a higher sensitivity of polymerization. In addition, it is more sensitive to those relatively weak functional connection regions. Thus, the study concludes that in the process of receiving emotional stimuli, the relatively obvious activation areas are mainly distributed in the frontal lobe, cingulum and near the hypothalamus. Furthermore, density-based k-means clustering method creates a more reliable method for follow-up studies of brain functional connectivity.

The calculations of small molecular conformation energy differences by density functional method

Science.gov (United States)

Topol, I. A.; Burt, S. K.

1993-03-01

The differences in the conformational energies for the gauche (G) and trans(T) conformers of 1,2-difluoroethane and for myo-and scyllo-conformer of inositol have been calculated by local density functional method (LDF approximation) with geometry optimization using different sets of calculation parameters. It is shown that in the contrast to Hartree—Fock methods, density functional calculations reproduce the correct sign and value of the gauche effect for 1,2-difluoroethane and energy difference for both conformers of inositol. The results of normal vibrational analysis for1,2-difluoroethane showed that harmonic frequencies calculated in LDF approximation agree with experimental data with the accuracy typical for scaled large basis set Hartree—Fock calculations.

Method of local pointed function reduction of original shape in Fourier transformation

International Nuclear Information System (INIS)

Dosch, H.; Slavyanov, S.Yu.

2002-01-01

The method for analytical reduction of the original shape in the one-dimensional Fourier transformation by the fourier image modulus is proposed. The basic concept of the method consists in the presentation of the model shape in the form of the local peak functions sum. The eigenfunctions, generated by the linear differential equations with the polynomial coefficients, are selected as the latter ones. This provides for the possibility of managing the Fourier transformation without numerical integration. This reduces the reverse task to the nonlinear regression with a small number of the evaluated parameters and to the numerical or asymptotic study on the model peak functions - the eigenfunctions of the differential tasks and their fourier images [ru

Non-equilibrium Green function method: theory and application in simulation of nanometer electronic devices

International Nuclear Information System (INIS)

Do, Van-Nam

2014-01-01

We review fundamental aspects of the non-equilibrium Green function method in the simulation of nanometer electronic devices. The method is implemented into our recently developed computer package OPEDEVS to investigate transport properties of electrons in nano-scale devices and low-dimensional materials. Concretely, we present the definition of the four real-time Green functions, the retarded, advanced, lesser and greater functions. Basic relations among these functions and their equations of motion are also presented in detail as the basis for the performance of analytical and numerical calculations. In particular, we review in detail two recursive algorithms, which are implemented in OPEDEVS to solve the Green functions defined in finite-size opened systems and in the surface layer of semi-infinite homogeneous ones. Operation of the package is then illustrated through the simulation of the transport characteristics of a typical semiconductor device structure, the resonant tunneling diodes. (review)