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Sample records for general tautochrone problem

  1. General problems

    International Nuclear Information System (INIS)

    2005-01-01

    This article presents the general problems as natural disasters, consequences of global climate change, public health, the danger of criminal actions, the availability to information about problems of environment

  2. Problem Solving with General Semantics.

    Science.gov (United States)

    Hewson, David

    1996-01-01

    Discusses how to use general semantics formulations to improve problem solving at home or at work--methods come from the areas of artificial intelligence/computer science, engineering, operations research, and psychology. (PA)

  3. On generalized operator quasi-equilibrium problems

    Science.gov (United States)

    Kum, Sangho; Kim, Won Kyu

    2008-09-01

    In this paper, we will introduce the generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which generalize the operator equilibrium problem due to Kazmi and Raouf [K.R. Kazmi, A. Raouf, A class of operator equilibrium problems, J. Math. Anal. Appl. 308 (2005) 554-564] into multi-valued and quasi-equilibrium problems. Using a Fan-Browder type fixed point theorem in [S. Park, Foundations of the KKM theory via coincidences of composites of upper semicontinuous maps, J. Korean Math. Soc. 31 (1994) 493-519] and an existence theorem of equilibrium for 1-person game in [X.-P. Ding, W.K. Kim, K.-K. Tan, Equilibria of non-compact generalized games with L*-majorized preferences, J. Math. Anal. Appl. 164 (1992) 508-517] as basic tools, we prove new existence theorems on generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which includes operator equilibrium problems.

  4. Dimensional reduction of a generalized flux problem

    International Nuclear Information System (INIS)

    Moroz, A.

    1992-01-01

    In this paper, a generalized flux problem with Abelian and non-Abelian fluxes is considered. In the Abelian case we shall show that the generalized flux problem for tight-binding models of noninteracting electrons on either 2n- or (2n + 1)-dimensional lattice can always be reduced to an n-dimensional hopping problem. A residual freedom in this reduction enables one to identify equivalence classes of hopping Hamiltonians which have the same spectrum. In the non-Abelian case, the reduction is not possible in general unless the flux tensor factorizes into an Abelian one times are element of the corresponding algebra

  5. Algorithm for the Stochastic Generalized Transportation Problem

    Directory of Open Access Journals (Sweden)

    Marcin Anholcer

    2012-01-01

    Full Text Available The equalization method for the stochastic generalized transportation problem has been presented. The algorithm allows us to find the optimal solution to the problem of minimizing the expected total cost in the generalized transportation problem with random demand. After a short introduction and literature review, the algorithm is presented. It is a version of the method proposed by the author for the nonlinear generalized transportation problem. It is shown that this version of the method generates a sequence of solutions convergent to the KKT point. This guarantees the global optimality of the obtained solution, as the expected cost functions are convex and twice differentiable. The computational experiments performed for test problems of reasonable size show that the method is fast. (original abstract

  6. A generalization of the convex Kakeya problem

    KAUST Repository

    Ahn, Heekap; Bae, Sangwon; Cheong, Otfried; Gudmundsson, Joachim; Tokuyama, Takeshi; Vigneron, Antoine E.

    2012-01-01

    We consider the following geometric alignment problem: Given a set of line segments in the plane, find a convex region of smallest area that contains a translate of each input segment. This can be seen as a generalization of Kakeya's problem

  7. Generalized network improvement and packing problems

    CERN Document Server

    Holzhauser, Michael

    2016-01-01

    Michael Holzhauser discusses generalizations of well-known network flow and packing problems by additional or modified side constraints. By exploiting the inherent connection between the two problem classes, the author investigates the complexity and approximability of several novel network flow and packing problems and presents combinatorial solution and approximation algorithms. Contents Fractional Packing and Parametric Search Frameworks Budget-Constrained Minimum Cost Flows: The Continuous Case Budget-Constrained Minimum Cost Flows: The Discrete Case Generalized Processing Networks Convex Generalized Flows Target Groups Researchers and students in the fields of mathematics, computer science, and economics Practitioners in operations research and logistics The Author Dr. Michael Holzhauser studied computer science at the University of Kaiserslautern and is now a research fellow in the Optimization Research Group at the Department of Mathematics of the University of Kaiserslautern.

  8. Prevalence of alcohol problems in general practice

    DEFF Research Database (Denmark)

    Rambaldi, A; Todisco, N; Gluud, C

    1996-01-01

    The Michigan Alcoholism Screening Test (MAST) and the response to a question about heavy alcohol consumption were used to assess the prevalence of alcohol problems in consecutive patients (77 males and 46 females) consulting a general practitioner in an urban area in the South of Italy (Castellam...... as a screening question in order to detect alcohol problems and give advice regarding reduction of alcohol consumption....

  9. Generalized production planning problem under interval uncertainty

    Directory of Open Access Journals (Sweden)

    Samir A. Abass

    2010-06-01

    Full Text Available Data in many real life engineering and economical problems suffer from inexactness. Herein we assume that we are given some intervals in which the data can simultaneously and independently perturb. We consider the generalized production planning problem with interval data. The interval data are in both of the objective function and constraints. The existing results concerning the qualitative and quantitative analysis of basic notions in parametric production planning problem. These notions are the set of feasible parameters, the solvability set and the stability set of the first kind.

  10. A general heuristic for genome rearrangement problems.

    Science.gov (United States)

    Dias, Ulisses; Galvão, Gustavo Rodrigues; Lintzmayer, Carla Négri; Dias, Zanoni

    2014-06-01

    In this paper, we present a general heuristic for several problems in the genome rearrangement field. Our heuristic does not solve any problem directly, it is rather used to improve the solutions provided by any non-optimal algorithm that solve them. Therefore, we have implemented several algorithms described in the literature and several algorithms developed by ourselves. As a whole, we implemented 23 algorithms for 9 well known problems in the genome rearrangement field. A total of 13 algorithms were implemented for problems that use the notions of prefix and suffix operations. In addition, we worked on 5 algorithms for the classic problem of sorting by transposition and we conclude the experiments by presenting results for 3 approximation algorithms for the sorting by reversals and transpositions problem and 2 approximation algorithms for the sorting by reversals problem. Another algorithm with better approximation ratio can be found for the last genome rearrangement problem, but it is purely theoretical with no practical implementation. The algorithms we implemented in addition to our heuristic lead to the best practical results in each case. In particular, we were able to improve results on the sorting by transpositions problem, which is a very special case because many efforts have been made to generate algorithms with good results in practice and some of these algorithms provide results that equal the optimum solutions in many cases. Our source codes and benchmarks are freely available upon request from the authors so that it will be easier to compare new approaches against our results.

  11. Generalized Riemann problem for reactive flows

    International Nuclear Information System (INIS)

    Ben-Artzi, M.

    1989-01-01

    A generalized Riemann problem is introduced for the equations of reactive non-viscous compressible flow in one space dimension. Initial data are assumed to be linearly distributed on both sides of a jump discontinuity. The resolution of the singularity is studied and the first-order variation (in time) of flow variables is given in exact form. copyright 1989 Academic Press, Inc

  12. Generalized Benders’ Decomposition for topology optimization problems

    DEFF Research Database (Denmark)

    Munoz Queupumil, Eduardo Javier; Stolpe, Mathias

    2011-01-01

    ) problems with discrete design variables to global optimality. We present the theoretical aspects of the method, including a proof of finite convergence and conditions for obtaining global optimal solutions. The method is also linked to, and compared with, an Outer-Approximation approach and a mixed 0......–1 semi definite programming formulation of the considered problem. Several ways to accelerate the method are suggested and an implementation is described. Finally, a set of truss topology optimization problems are numerically solved to global optimality.......This article considers the non-linear mixed 0–1 optimization problems that appear in topology optimization of load carrying structures. The main objective is to present a Generalized Benders’ Decomposition (GBD) method for solving single and multiple load minimum compliance (maximum stiffness...

  13. Lobb's Generalization of Catalan's Parenthesization Problem

    Science.gov (United States)

    Koshy, Thomas

    2009-01-01

    A. Lobb discovered an interesting generalization of Catalan's parenthesization problem, namely: Find the number L(n, m) of arrangements of n + m positive ones and n - m negative ones such that every partial sum is nonnegative, where 0 = m = n. This article uses Lobb's formula, L(n, m) = (2m + 1)/(n + m + 1) C(2n, n + m), where C is the usual…

  14. Generalized Darcy–Oseen resolvent problem

    Czech Academy of Sciences Publication Activity Database

    Medková, Dagmar; Ptashnyk, M.; Varnhorn, W.

    2016-01-01

    Roč. 39, č. 6 (2016), s. 1621-1630 ISSN 0170-4214 Institutional support: RVO:67985840 Keywords : Darcy-Oseen resolvent problem * semipermeable membrane * Brinkman-Darcy equations * fluid flow between free-fluid domains and porous media Subject RIV: BA - General Mathematics Impact factor: 1.017, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/mma.3872/abstract

  15. A generalization of the convex Kakeya problem

    KAUST Repository

    Ahn, Heekap

    2012-01-01

    We consider the following geometric alignment problem: Given a set of line segments in the plane, find a convex region of smallest area that contains a translate of each input segment. This can be seen as a generalization of Kakeya\\'s problem of finding a convex region of smallest area such that a needle can be turned through 360 degrees within this region. Our main result is an optimal Θ(n log n)-time algorithm for our geometric alignment problem, when the input is a set of n line segments. We also show that, if the goal is to minimize the perimeter of the region instead of its area, then the optimum placement is when the midpoints of the segments coincide. Finally, we show that for any compact convex figure G, the smallest enclosing disk of G is a smallest-perimeter region containing a translate of any rotated copy of G. © 2012 Springer-Verlag Berlin Heidelberg.

  16. PROBLEMS OF GENERAL PRACTICE IN RURAL CALIFORNIA

    Science.gov (United States)

    Carey, Hollis L.; Andrews, Carroll B.

    1949-01-01

    Medical care for rural populations is an important problem facing the medical profession nationally and locally. The mechanism for solution lies in the existing American Medical Association and California Medical Association committees on rural medical service and further development of “local health councils.” Additional emphasis on training of physicians for general practice is essential through medical school graduate and postgraduate periods. The problem of providing additional adequately equipped and staffed hospitals must receive much consideration. Recognizing that passiveness invites aggressive non-medical agencies to foster bureaucratic dictation inimical to the practice of medicine, the rural physician must act through medical and community organizations to correct weaknesses in the structure of medical practice. PMID:18116230

  17. Gambling Problems in the General Danish Population

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Jessen, Lasse J.; Lau, Morten

    We compare several popular survey instruments for measuring gambling behavior and gambling propensity to assess if they differ in their classification of individuals in the general adult Danish population. We also examine correlations with standard survey instruments for alcohol use, anxiety......, depression and impulsivity. A feature of our design is that nobody was excluded on the basis of their response to a “trigger,” “gateway” or “diagnostic item” question about previous gambling history. Our sample consists of 8,405 adult Danes. We administered the Focal Adult Gambling Screen to all subjects...... and estimate prevalence of gambling problems using sample weights and controlling for sample selection. We find that 95.4% of the population has no detectable risk, 2.9% has an early risk, 0.8% has an intermediate risk, 0.7% has an advanced risk, and 0.2% can be classified as problem gamblers...

  18. Anholonomic Cauchy problem in general relativity

    International Nuclear Information System (INIS)

    Stachel, J.

    1980-01-01

    The Lie derivative approach to the Cauchy problem in general relativity is applied to the evolution along an arbitrary timelike vector field for the case where the dynamical degrees of freedom are chosen as the (generally anholonomic) metric of the hypersurface elements orthogonal to the vector field. Generalizations of the shear, rotation, and acceleration are given for a nonunit timelike vector field, and applied to the three-plus-one breakup of the Riemann tensor into components parallel and orthogonal to the vector field, resulting in the anholonomic Gauss--Codazzi equations. A similar breakup of the Einstein field equations results in the form of the constraint and evolution equations for the anholonomic case. The results are applied to the case of a space--time with a timelike Killing vector field (stationary field) to demonstrate their utility. Other possible applications, such as in the numerical integration of the field equations, are mentioned. Definitions are given of three-index shear, rotation, and acceleration tensors, and their use in a two-plus-two decomposition of the Riemann tensor and field equations is indicated

  19. A generalization of the convex Kakeya problem

    KAUST Repository

    Ahn, Heekap

    2013-09-19

    Given a set of line segments in the plane, not necessarily finite, what is a convex region of smallest area that contains a translate of each input segment? This question can be seen as a generalization of Kakeya\\'s problem of finding a convex region of smallest area such that a needle can be rotated through 360 degrees within this region. We show that there is always an optimal region that is a triangle, and we give an optimal Θ(nlogn)-time algorithm to compute such a triangle for a given set of n segments. We also show that, if the goal is to minimize the perimeter of the region instead of its area, then placing the segments with their midpoint at the origin and taking their convex hull results in an optimal solution. Finally, we show that for any compact convex figure G, the smallest enclosing disk of G is a smallest-perimeter region containing a translate of every rotated copy of G. © 2013 Springer Science+Business Media New York.

  20. Dynamic problem of generalized thermoelastic diffusive medium

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajneesh; Kansal, Tarun [Kurukshetra University, Kurukshetra (India)

    2010-01-15

    The equations of generalized thermoelastic diffusion, based on the theory of Lord and Shulman with one relaxation time, are derived for anisotropic media with rotation. The variational principle and reciprocity theorem for the governing equations are derived. The propagation of leaky Rayleigh waves in a viscous fluid layer overlying a homogeneous isotropic, generalized thermoelastic diffusive half space with rotating frame of reference is studied

  1. General inverse problems for regular variation

    DEFF Research Database (Denmark)

    Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

    2014-01-01

    Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

  2. The Twin Prime Problem and Generalizations

    Indian Academy of Sciences (India)

    IAS Admin

    theory. Though several sophisticated tools were discov- ered, the problem defied many attempts to ... number theory and algebraic geometry. Thus ... goal to discuss some of these below. ..... values of d) ϱ2(d) by setting ϱ2(p) = νp(H) − 1 and.

  3. Cinema, Fermi Problems and General Education

    Science.gov (United States)

    Efthimiou, C. J.; Llewellyn, R. A.

    2007-01-01

    During the past few years the authors have developed a new approach to the teaching of physical science, a general education course typically found in the curricula of nearly every college and university. This approach, called "Physics in Films" (Efthimiou and Llewellyn 2006 Phys. Teach. 44 28-33), uses scenes from popular films to illustrate…

  4. General Research and Development problems in dismantling

    International Nuclear Information System (INIS)

    Lorin, C.

    1993-01-01

    R and D studies for dismantling nuclear facilities have been conducted in several domains: safety evaluation (3D cameras, gamma camera, gamma low level control bench, alpha measures); general studies (such as the Baladin software, an expert system for dismantling); decontamination techniques (utilisation of acid or base liquids, laser, ...); cutting techniques and tools (remote controlled grinder, remote controlled robot, carrier crane); robotics for remote operations and handling; waste processing

  5. Using a general problem-solving strategy to promote transfer.

    Science.gov (United States)

    Youssef-Shalala, Amina; Ayres, Paul; Schubert, Carina; Sweller, John

    2014-09-01

    Cognitive load theory was used to hypothesize that a general problem-solving strategy based on a make-as-many-moves-as-possible heuristic could facilitate problem solutions for transfer problems. In four experiments, school students were required to learn about a topic through practice with a general problem-solving strategy, through a conventional problem solving strategy or by studying worked examples. In Experiments 1 and 2 using junior high school students learning geometry, low knowledge students in the general problem-solving group scored significantly higher on near or far transfer tests than the conventional problem-solving group. In Experiment 3, an advantage for a general problem-solving group over a group presented worked examples was obtained on far transfer tests using the same curriculum materials, again presented to junior high school students. No differences between conditions were found in Experiments 1, 2, or 3 using test problems similar to the acquisition problems. Experiment 4 used senior high school students studying economics and found the general problem-solving group scored significantly higher than the conventional problem-solving group on both similar and transfer tests. It was concluded that the general problem-solving strategy was helpful for novices, but not for students that had access to domain-specific knowledge. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  6. The Human Mind As General Problem Solver

    Science.gov (United States)

    Gurr, Henry

    2011-10-01

    Since leaving U Cal Irvine Neutrino Research, I have been a University Physics Teacher, and an Informal Researcher Of Human Functionality. My talk will share what I discovered about the best ways to learn, many of which are regularities that are to be expected from the Neuronal Network Properties announced in the publications of physicist John Joseph Hopfield. Hopfield's Model of mammalian brain-body, provides solid instructive understanding of how best Learn, Solve Problems, Live! With it we understand many otherwise puzzling features of our intellect! Examples Why 1) Analogies and metaphors powerful in class instruction, ditto poems. 2) Best learning done in physical (Hands-On) situations with tight immediate dynamical feedback such as seen in learning to ride bike, drive car, speak language, etc. 3) Some of the best learning happens in seeming random exploration, bump around, trial and error. 4) Scientific discoveries happen, with no apparent effort, at odd moments. 5) Important discoveries DEPEND on considerable frustrating effort, then Flash of Insight AHA EURIKA.

  7. Strong Duality and Optimality Conditions for Generalized Equilibrium Problems

    Directory of Open Access Journals (Sweden)

    D. H. Fang

    2013-01-01

    Full Text Available We consider a generalized equilibrium problem involving DC functions. By using the properties of the epigraph of the conjugate functions, some sufficient and/or necessary conditions for the weak and strong duality results and optimality conditions for generalized equilibrium problems are provided.

  8. Problem solving therapy - use and effectiveness in general practice.

    Science.gov (United States)

    Pierce, David

    2012-09-01

    Problem solving therapy (PST) is one of the focused psychological strategies supported by Medicare for use by appropriately trained general practitioners. This article reviews the evidence base for PST and its use in the general practice setting. Problem solving therapy involves patients learning or reactivating problem solving skills. These skills can then be applied to specific life problems associated with psychological and somatic symptoms. Problem solving therapy is suitable for use in general practice for patients experiencing common mental health conditions and has been shown to be as effective in the treatment of depression as antidepressants. Problem solving therapy involves a series of sequential stages. The clinician assists the patient to develop new empowering skills, and then supports them to work through the stages of therapy to determine and implement the solution selected by the patient. Many experienced GPs will identify their own existing problem solving skills. Learning about PST may involve refining and focusing these skills.

  9. Computational Complexity of Some Problems on Generalized Cellular Automations

    Directory of Open Access Journals (Sweden)

    P. G. Klyucharev

    2012-03-01

    Full Text Available We prove that the preimage problem of a generalized cellular automation is NP-hard. The results of this work are important for supporting the security of the ciphers based on the cellular automations.

  10. Procrustes Problems for General, Triangular, and Symmetric Toeplitz Matrices

    Directory of Open Access Journals (Sweden)

    Juan Yang

    2013-01-01

    Full Text Available The Toeplitz Procrustes problems are the least squares problems for the matrix equation AX=B over some Toeplitz matrix sets. In this paper the necessary and sufficient conditions are obtained about the existence and uniqueness for the solutions of the Toeplitz Procrustes problems when the unknown matrices are constrained to the general, the triangular, and the symmetric Toeplitz matrices, respectively. The algorithms are designed and the numerical examples show that these algorithms are feasible.

  11. Higher-Order Generalized Invexity in Control Problems

    Directory of Open Access Journals (Sweden)

    S. K. Padhan

    2011-01-01

    Full Text Available We introduce a higher-order duality (Mangasarian type and Mond-Weir type for the control problem. Under the higher-order generalized invexity assumptions on the functions that compose the primal problems, higher-order duality results (weak duality, strong duality, and converse duality are derived for these pair of problems. Also, we establish few examples in support of our investigation.

  12. A general approach to posterior contraction in nonparametric inverse problems

    NARCIS (Netherlands)

    Knapik, Bartek; Salomond, Jean Bernard

    In this paper, we propose a general method to derive an upper bound for the contraction rate of the posterior distribution for nonparametric inverse problems. We present a general theorem that allows us to derive contraction rates for the parameter of interest from contraction rates of the related

  13. Numerical solution of pipe flow problems for generalized Newtonian fluids

    International Nuclear Information System (INIS)

    Samuelsson, K.

    1993-01-01

    In this work we study the stationary laminar flow of incompressible generalized Newtonian fluids in a pipe with constant arbitrary cross-section. The resulting nonlinear boundary value problems can be written in a variational formulation and solved using finite elements and the augmented Lagrangian method. The solution of the boundary value problem is obtained by finding a saddle point of the augmented Lagrangian. In the algorithm the nonlinear part of the equations is treated locally and the solution is obtained by iteration between this nonlinear problem and a global linear problem. For the solution of the linear problem we use the SSOR preconditioned conjugate gradient method. The approximating problem is solved on a sequence of adaptively refined grids. A scheme for adjusting the value of the crucial penalization parameter of the augmented Lagrangian is proposed. Applications to pipe flow and a problem from the theory of capacities are given. (author) (34 refs.)

  14. Generalized Nash equilibrium problems, bilevel programming and mpec

    CERN Document Server

    Lalitha, CS

    2017-01-01

    The book discusses three classes of problems: the generalized Nash equilibrium problems, the bilevel problems and the mathematical programming with equilibrium constraints (MPEC). These problems interact through their mathematical analysis as well as their applications. The primary aim of the book is to present the modern tool of variational analysis and optimization, which are used to analyze these three classes of problems. All contributing authors are respected academicians, scientists and researchers from around the globe. These contributions are based on the lectures delivered by experts at CIMPA School, held at the University of Delhi, India, from 25 November–6 December 2013, and peer-reviewed by international experts. The book contains five chapters. Chapter 1 deals with nonsmooth, nonconvex bilevel optimization problems whose feasible set is described by using the graph of the solution set mapping of a parametric optimization problem. Chapter 2 describes a constraint qualification to MPECs considere...

  15. Generalized coherent states for the Coulomb problem in one dimension

    International Nuclear Information System (INIS)

    Nouri, S.

    2002-01-01

    A set of generalized coherent states for the one-dimensional Coulomb problem in coordinate representation is constructed. At first, we obtain a mapping for proper transformation of the one-dimensional Coulomb problem into a nonrotating four-dimensional isotropic harmonic oscillator in the hyperspherical space, and the generalized coherent states for the one-dimensional Coulomb problem is then obtained in exact closed form. This exactly soluble model can provide an adequate means for a quantum coherency description of the Coulomb problem in one dimension, sample for coherent aspects of the exciton model in one-dimension example in high-temperature superconductivity, semiconductors, and polymers. Also, it can be useful for investigating the coherent scattering of the Coulomb particles in one dimension

  16. Investigation of Free Particle Propagator with Generalized Uncertainty Problem

    International Nuclear Information System (INIS)

    Hassanabadi, H.; Ghobakhloo, F.

    2016-01-01

    We consider the Schrödinger equation with a generalized uncertainty principle for a free particle. We then transform the problem into a second-order ordinary differential equation and thereby obtain the corresponding propagator. The result of ordinary quantum mechanics is recovered for vanishing minimal length parameter.

  17. A generalization of the finiteness problem in local cohomology ...

    Indian Academy of Sciences (India)

    (Math. Sci.) Vol. 119, No. 2, April 2009, pp. 159–164. © Printed in India. A generalization of the finiteness problem in local cohomology modules. AMIR MAFI. Department of Mathematics, University of Kurdistan, P.O. Box 416, Sanandaj, Iran. Institute for Studies in Theoretical Physics and Mathematics, P.O. Box 19395-5746,.

  18. Problem-Based Learning in a General Psychology Course.

    Science.gov (United States)

    Willis, Sandra A.

    2002-01-01

    Describes the adoption of problem-based learning (PBL) techniques in a general psychology course. States that the instructor used a combination of techniques, including think-pair-share, lecture/discussion, and PBL. Notes means and standard deviations for graded components of PBL format versus lecture/discussion format. (Contains 18 references.)…

  19. Energy-momentum distribution: A crucial problem in general relativity

    NARCIS (Netherlands)

    Sharif, M.; Fatima, T.

    2005-01-01

    This paper is aimed to elaborate the problem of energy–momentum in general relativity. In this connection, we use the prescriptions of Einstein, Landau–Lifshitz, Papapetrou and Möller to compute the energy–momentum densities for two exact solutions of Einstein field equations. The space–times under

  20. Municipal solid waste management problems: an applied general equilibrium analysis

    NARCIS (Netherlands)

    Bartelings, H.

    2003-01-01

    Keywords: Environmental policy; General equilibrium modeling; Negishi format; Waste management policies; Market distortions.

    About 40% of the entire budget spent on environmental problems in the

  1. Jacobi-Davidson methods for generalized MHD-eigenvalue problems

    NARCIS (Netherlands)

    J.G.L. Booten; D.R. Fokkema; G.L.G. Sleijpen; H.A. van der Vorst (Henk)

    1995-01-01

    textabstractA Jacobi-Davidson algorithm for computing selected eigenvalues and associated eigenvectors of the generalized eigenvalue problem $Ax = lambda Bx$ is presented. In this paper the emphasis is put on the case where one of the matrices, say the B-matrix, is Hermitian positive definite. The

  2. Band Generalization of the Golub-Kahan Bidiagonalization, Generalized Jacobi Matrices, and the Core Problem

    Czech Academy of Sciences Publication Activity Database

    Hnětynková, Iveta; Plešinger, M.; Strakoš, Z.

    2015-01-01

    Roč. 36, č. 2 (2015), s. 417-434 ISSN 0895-4798 R&D Projects: GA ČR GA13-06684S Grant - others:GA MŠk(CZ) EE2.3.30.0065; GA MŠk(CZ) LL1202 Keywords : total least squares problem * multiple right-hand sides * core problem * Golub-Kahan bidiagonalization * generalized Jacobi matrices Subject RIV: BA - General Mathematics Impact factor: 1.883, year: 2015

  3. Application of Neutrosophic Set Theory in Generalized Assignment Problem

    Directory of Open Access Journals (Sweden)

    Supriya Kar

    2015-09-01

    Full Text Available This paper presents the application of Neutrosophic Set Theory (NST in solving Generalized Assignment Problem (GAP. GAP has been solved earlier under fuzzy environment. NST is a generalization of the concept of classical set, fuzzy set, interval-valued fuzzy set, intuitionistic fuzzy set. Elements of Neutrosophic set are characterized by a truth-membership function, falsity and also indeterminacy which is a more realistic way of expressing the parameters in real life problem. Here the elements of the cost matrix for the GAP are considered as neutrosophic elements which have not been considered earlier by any other author. The problem has been solved by evaluating score function matrix and then solving it by Extremum Difference Method (EDM [1] to get the optimal assignment. The method has been demonstrated by a suitable numerical example.

  4. Polymorphic Uncertain Linear Programming for Generalized Production Planning Problems

    Directory of Open Access Journals (Sweden)

    Xinbo Zhang

    2014-01-01

    Full Text Available A polymorphic uncertain linear programming (PULP model is constructed to formulate a class of generalized production planning problems. In accordance with the practical environment, some factors such as the consumption of raw material, the limitation of resource and the demand of product are incorporated into the model as parameters of interval and fuzzy subsets, respectively. Based on the theory of fuzzy interval program and the modified possibility degree for the order of interval numbers, a deterministic equivalent formulation for this model is derived such that a robust solution for the uncertain optimization problem is obtained. Case study indicates that the constructed model and the proposed solution are useful to search for an optimal production plan for the polymorphic uncertain generalized production planning problems.

  5. Stochastic programming problems with generalized integrated chance constraints

    Czech Academy of Sciences Publication Activity Database

    Branda, Martin

    2012-01-01

    Roč. 61, č. 8 (2012), s. 949-968 ISSN 0233-1934 R&D Projects: GA ČR GAP402/10/1610 Grant - others:SVV(CZ) 261315/2010 Institutional support: RVO:67985556 Keywords : chance constraints * integrated chance constraints * penalty functions * sample approximations * blending problem Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.707, year: 2012 http://library.utia.cas.cz/separaty/2012/E/branda-stochastic programming problems with generalized integrated.pdf

  6. A New Inexact Inverse Subspace Iteration for Generalized Eigenvalue Problems

    Directory of Open Access Journals (Sweden)

    Fatemeh Mohammad

    2014-05-01

    Full Text Available In this paper‎, ‎we represent an inexact inverse‎ ‎subspace iteration method for computing a few eigenpairs of the‎ ‎generalized eigenvalue problem $Ax = \\lambda Bx$[Q.~Ye and P.~Zhang‎, ‎Inexact inverse subspace iteration for generalized eigenvalue‎ ‎problems‎, ‎Linear Algebra and its Application‎, ‎434 (2011 1697-1715‎‎]‎. ‎In particular‎, ‎the linear convergence property of the inverse‎ ‎subspace iteration is preserved‎.

  7. Problem drinking - detection and assessment in general practice.

    Science.gov (United States)

    Demirkol, Apo; Haber, Paul; Conigrave, Katherine

    2011-08-01

    Alcohol has long been an integral part of the social life of many Australians. However, alcohol is associated with significant harm to drinkers, and also to nondrinkers. This article explores the role of the general practitioner in the detection and assessment of problem drinking. Excessive alcohol use is a major public health problem and the majority of people who drink excessively go undetected. General practitioners are in a good position to detect excessive alcohol consumption; earlier intervention can help improve outcomes. AUDIT-C is an effective screening tool for the detection of problem drinking. National Health and Medical Research Council guidelines suggest that no more than two standard drinks on each occasion will keep lifetime risk of death from alcohol related disease or injury at a low level. Once an alcohol problem is detected it is important to assess for alcohol dependence, other substance use, motivation to change, psychiatric comorbidities and examination and investigation findings that may be associated with excessive alcohol use. A comprehensive assessment of the impact and risk of harm of the patient's drinking to themselves and others is vital, and may require several consultations.

  8. Does Preschool Self-Regulation Predict Later Behavior Problems in General or Specific Problem Behaviors?

    Science.gov (United States)

    Lonigan, Christopher J; Spiegel, Jamie A; Goodrich, J Marc; Morris, Brittany M; Osborne, Colleen M; Lerner, Matthew D; Phillips, Beth M

    2017-11-01

    Findings from prior research have consistently indicated significant associations between self-regulation and externalizing behaviors. Significant associations have also been reported between children's language skills and both externalizing behaviors and self-regulation. Few studies to date, however, have examined these relations longitudinally, simultaneously, or with respect to unique clusters of externalizing problems. The current study examined the influence of preschool self-regulation on general and specific externalizing behavior problems in early elementary school and whether these relations were independent of associations between language, self-regulation, and externalizing behaviors in a sample of 815 children (44% female). Additionally, given a general pattern of sex differences in the presentations of externalizing behavior problems, self-regulation, and language skills, sex differences for these associations were examined. Results indicated unique relations of preschool self-regulation and language with both general externalizing behavior problems and specific problems of inattention. In general, self-regulation was a stronger longitudinal correlate of externalizing behavior for boys than it was for girls, and language was a stronger longitudinal predictor of hyperactive/impulsive behavior for girls than it was for boys.

  9. An Enhanced Genetic Algorithm for the Generalized Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    H. Jafarzadeh

    2017-12-01

    Full Text Available The generalized traveling salesman problem (GTSP deals with finding the minimum-cost tour in a clustered set of cities. In this problem, the traveler is interested in finding the best path that goes through all clusters. As this problem is NP-hard, implementing a metaheuristic algorithm to solve the large scale problems is inevitable. The performance of these algorithms can be intensively promoted by other heuristic algorithms. In this study, a search method is developed that improves the quality of the solutions and competition time considerably in comparison with Genetic Algorithm. In the proposed algorithm, the genetic algorithms with the Nearest Neighbor Search (NNS are combined and a heuristic mutation operator is applied. According to the experimental results on a set of standard test problems with symmetric distances, the proposed algorithm finds the best solutions in most cases with the least computational time. The proposed algorithm is highly competitive with the published until now algorithms in both solution quality and running time.

  10. A Generalized Cauchy Distribution Framework for Problems Requiring Robust Behavior

    Directory of Open Access Journals (Sweden)

    Carrillo RafaelE

    2010-01-01

    Full Text Available Statistical modeling is at the heart of many engineering problems. The importance of statistical modeling emanates not only from the desire to accurately characterize stochastic events, but also from the fact that distributions are the central models utilized to derive sample processing theories and methods. The generalized Cauchy distribution (GCD family has a closed-form pdf expression across the whole family as well as algebraic tails, which makes it suitable for modeling many real-life impulsive processes. This paper develops a GCD theory-based approach that allows challenging problems to be formulated in a robust fashion. Notably, the proposed framework subsumes generalized Gaussian distribution (GGD family-based developments, thereby guaranteeing performance improvements over traditional GCD-based problem formulation techniques. This robust framework can be adapted to a variety of applications in signal processing. As examples, we formulate four practical applications under this framework: (1 filtering for power line communications, (2 estimation in sensor networks with noisy channels, (3 reconstruction methods for compressed sensing, and (4 fuzzy clustering.

  11. A General Solution Framework for Component-Commonality Problems

    Directory of Open Access Journals (Sweden)

    Nils Boysen

    2009-05-01

    Full Text Available Component commonality - the use of the same version of a component across multiple products - is being increasingly considered as a promising way to offer high external variety while retaining low internal variety in operations. However, increasing commonality has both positive and negative cost effects, so that optimization approaches are required to identify an optimal commonality level. As components influence to a greater or lesser extent nearly every process step along the supply chain, it is not surprising that a multitude of diverging commonality problems is being investigated in literature, each of which are developing a specific algorithm designed for the respective commonality problem being considered. The paper on hand aims at a general framework which is flexible and efficient enough to be applied to a wide range of commonality problems. Such a procedure based on a two-stage graph approach is presented and tested. Finally, flexibility of the procedure is shown by customizing the framework to account for different types of commonality problems.

  12. Generalized Artificial Life Structure for Time-dependent Problems

    Institute of Scientific and Technical Information of China (English)

    TSAU Minhe; KAO Weiwen; CHANG Albert

    2009-01-01

    In recent years, more attention has been paid on artificial life researches. Artificial life(AL) is a research on regulating gene parameters of digital organisms under complicated problematic environments through natural selections and evolutions to achieve the final emergence of intelligence. Most recent studies focused on solving certain real problems by artificial life methods, yet without much address on the AL life basic mechanism. The real problems are often very complicated, and the proposed methods sometimes seem too simple to handle those problems. This study proposed a new approach in AL research, named "generalized artificial life structure(GALS)", in which the traditional "gene bits" in genetic algorithms is first replaced by "gene parameters", which could appear anywhere in GALS. A modeling procedure is taken to normalize the input data, and AL "tissue" is innovated to make AL more complex. GALS is anticipated to contribute significantly to the fitness of AL evolution. The formation of"tissue" begins with some different AL basic cells, and then tissue is produced by the casual selections of one or several of these cells. As a result, the gene parameters, represented by "tissues", could become highly diversified. This diversification should have obvious effects on improving gene fitness. This study took the innovative method of GALS in a stock forecasting problem under a carefully designed manipulating platform. And the researching results verify that the GALS is successful in improving the gene evolution fitness.

  13. The problem of time quantum mechanics versus general relativity

    CERN Document Server

    Anderson, Edward

    2017-01-01

    This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon ...

  14. Spectrum of general surgical problems in the developmentally disabled adults

    International Nuclear Information System (INIS)

    Khalid, K.; Al-Salamah, Saleh M.

    2006-01-01

    This study highlights the spectrum of general surgical problems necessitating admission on intellectually disabled adult patients. Problems encountered in the management and the ways to overcome various difficulties are highlighted. Prospective collection of data on 63 consecutive developmentally disabled adult patients admitted to the Department of General Surgery, Riyadh Medical Complex (RMC), Riyadh, Kingdom of Saudi Arabia for various indications from January 2000 through December 2004. Demographic details, clinical presentation, diagnostic modalities, associated physical and neurological disabilities, coexisting medical condition, treatment options, morbidity and mortality were analyzed. Various difficulties encountered during the management and mean to overcome these problems are addressed. Sixty-three patients accounted for 71 admissions. Mean age was 26.7 years with a male preponderance (4.25:1). Fifty-four patients were admitted for various emergency conditions. History of pica could be obtained in 33% of the cases. Twenty-seven patients were admitted for acute abdomen. Volvulus of the colon (22.2%) and pseudo-obstruction (18.5%) were the most common causes of acute abdomen. Twenty-one patients were admitted with upper gastrointestinal bleeding. Reflux esophagitis was the most common cause of bleeding (62%). Overall morbidity was 41% for emergency admissions and 22% for elective surgery. Hospital mortality was 21.4% for emergency surgery. There was no death in elective cases. Developmentally disabled patients comprise a special class of patients with peculiar management problems. The treating clinician should be aware of various unexpected conditions not found as frequently in the normal patient population. Apparent lack of pain does not exclude an acute emergency. Possible surgical condition should be suspected if there is vomiting, abdominal distension, fever, increased irritability of recent onset. Male gender and history of pica are added risk factors

  15. Homotopy Method for a General Multiobjective Programming Problem under Generalized Quasinormal Cone Condition

    Directory of Open Access Journals (Sweden)

    X. Zhao

    2012-01-01

    Full Text Available A combined interior point homotopy continuation method is proposed for solving general multiobjective programming problem. We prove the existence and convergence of a smooth homotopy path from almost any interior initial interior point to a solution of the KKT system under some basic assumptions.

  16. Non-integrability of the generalized spring-pendulum problem

    International Nuclear Information System (INIS)

    Maciejewski, Andrzej J; Przybylska, Maria; Weil, Jacques-Arthur

    2004-01-01

    We investigate a generalization of the three-dimensional spring-pendulum system. The problem depends on two real parameters (k, a), where k is the Young modulus of the spring and a describes the nonlinearity of elastic forces. We show that this system is not integrable when k ≠ -a. We carefully investigated the case k = -a when the necessary condition for integrability given by the Morales-Ruiz-Ramis theory is satisfied. We discuss an application of the higher order variational equations for proving the non-integrability in this case

  17. PARETO OPTIMAL SOLUTIONS FOR MULTI-OBJECTIVE GENERALIZED ASSIGNMENT PROBLEM

    Directory of Open Access Journals (Sweden)

    S. Prakash

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The Multi-Objective Generalized Assignment Problem (MGAP with two objectives, where one objective is linear and the other one is non-linear, has been considered, with the constraints that a job is assigned to only one worker – though he may be assigned more than one job, depending upon the time available to him. An algorithm is proposed to find the set of Pareto optimal solutions of the problem, determining assignments of jobs to workers with two objectives without setting priorities for them. The two objectives are to minimise the total cost of the assignment and to reduce the time taken to complete all the jobs.

    AFRIKAANSE OPSOMMING: ‘n Multi-doelwit veralgemeende toekenningsprobleem (“multi-objective generalised assignment problem – MGAP” met twee doelwitte, waar die een lineêr en die ander nielineêr is nie, word bestudeer, met die randvoorwaarde dat ‘n taak slegs toegedeel word aan een werker – alhoewel meer as een taak aan hom toegedeel kan word sou die tyd beskikbaar wees. ‘n Algoritme word voorgestel om die stel Pareto-optimale oplossings te vind wat die taaktoedelings aan werkers onderhewig aan die twee doelwitte doen sonder dat prioriteite toegeken word. Die twee doelwitte is om die totale koste van die opdrag te minimiseer en om die tyd te verminder om al die take te voltooi.

  18. Origins and development of the Cauchy problem in general relativity

    International Nuclear Information System (INIS)

    Ringström, Hans

    2015-01-01

    The seminal work of Yvonne Choquet-Bruhat published in 1952 demonstrates that it is possible to formulate Einstein's equations as an initial value problem. The purpose of this article is to describe the background to and impact of this achievement, as well as the result itself. In some respects, the idea of viewing the field equations of general relativity as a system of evolution equations goes back to Einstein himself; in an argument justifying that gravitational waves propagate at the speed of light, Einstein used a special choice of coordinates to derive a system of wave equations for the linear perturbations on a Minkowski background. Over the following decades, Hilbert, de Donder, Lanczos, Darmois and many others worked to put Einstein's ideas on a more solid footing. In fact, the issue of local uniqueness (giving a rigorous justification for the statement that the speed of propagation of the gravitational field is bounded by that of light) was already settled in the 1930s by the work of Stellmacher. However, the first person to demonstrate both local existence and uniqueness in a setting in which the notion of finite speed of propagation makes sense was Yvonne Choquet-Bruhat. In this sense, her work lays the foundation for the formulation of Einstein's equations as an initial value problem. Following a description of the results of Choquet-Bruhat, we discuss the development of three research topics that have their origin in her work. The first one is local existence. One reason for addressing it is that it is at the heart of the original paper. Moreover, it is still an active and important research field, connected to the problem of characterizing the asymptotic behaviour of solutions that blow up in finite time. As a second topic, we turn to the questions of global uniqueness and strong cosmic censorship. These questions are of fundamental importance to anyone interested in justifying that the Cauchy problem makes sense globally. They are

  19. POWERPLAY: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem

    Directory of Open Access Journals (Sweden)

    Jürgen eSchmidhuber

    2013-06-01

    Full Text Available Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. The novel algorithmic framework POWERPLAY (2011 continually searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Wow-effects are achieved by continually making previously learned skills more efficient such that they require less time and space. New skills may (partially re-use previously learned skills. POWERPLAY's search orders candidate pairs of tasks and solver modifications by their conditional computational (time & space complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. The computational costs of validating new tasks need not grow with task repertoire size. POWERPLAY's ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Goedel's sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing repertoire of problem solving procedures can be exploited by a parallel search for solutions to additional externally posed tasks. POWERPLAY may be viewed as a greedy but practical implementation of basic principles of creativity. A first experimental analysis can be found in separate papers [58, 56, 57].

  20. Modified and fuzzified general problem solver for 'monkey and banana' problem

    International Nuclear Information System (INIS)

    Sano, Norihide; Takahashi, Ryoichi.

    1994-01-01

    Automatic operation is important for the in-service inspection of nuclear power stations of the decommission of retired plants. Master and slave control will be introduced for work-robot control. It is desirable that the slave possess problem-solving capabilities. In this paper we assume that the slave incorporates the general problem solver (GPS) algorithm. In view of having solved the 'monkey and banana' problem, the slave system is regarded as reasonable alternative which incorporates the capability of problem-solving. Basically, the GPS solves a problem by reducing the difference between the initial state and goal state, and hence the performance of GPS depends on selection of the difference to be reduced. The conventional GPS is given the order of importance of the differences in advance. In this study, the GPS was improved by making use of the rules which determine the order. When several choices are available for the given difference, a fuzzified decision to determine the necessary action is made, as demonstrated in this paper. (author)

  1. An efficient iterative method for the generalized Stokes problem

    Energy Technology Data Exchange (ETDEWEB)

    Sameh, A. [Univ. of Minnesota, Twin Cities, MN (United States); Sarin, V. [Univ. of Illinois, Urbana, IL (United States)

    1996-12-31

    This paper presents an efficient iterative scheme for the generalized Stokes problem, which arises frequently in the simulation of time-dependent Navier-Stokes equations for incompressible fluid flow. The general form of the linear system is where A = {alpha}M + vT is an n x n symmetric positive definite matrix, in which M is the mass matrix, T is the discrete Laplace operator, {alpha} and {nu} are positive constants proportional to the inverses of the time-step {Delta}t and the Reynolds number Re respectively, and B is the discrete gradient operator of size n x k (k < n). Even though the matrix A is symmetric and positive definite, the system is indefinite due to the incompressibility constraint (B{sup T}u = 0). This causes difficulties both for iterative methods and commonly used preconditioners. Moreover, depending on the ratio {alpha}/{nu}, A behaves like the mass matrix M at one extreme and the Laplace operator T at the other, thus complicating the issue of preconditioning.

  2. Modified and fuzzified general problem solver for 'monkey and banana' problem, 2

    International Nuclear Information System (INIS)

    Sano, Norihide; Takahashi, Ryoichi.

    1991-01-01

    The automatic operation is important for the in-service inspection of the operating nuclear power station or the decommission of retired plants. The master and slave control will be introduced for work-robot control. It is desirable that the slave involves the capability of problem solving. This paper assumed that the slave involved the general problem solver algorithm. In view of having solved the puzzle of the 'monkey and banana', the slave system is regarded as the reasonable alternative which incorporates the capability of problem solving. Basically, the GPS solves a problem by reducing the difference between an initial state and a goal state, and hence the performance of GPS depends on selecting the difference to be reduced. The usual GPS is given in advance the ordering which indicates the importance of the differences. In this paper, the GPS was improved by making use of the rules which decide the order. When several choices are found on the given difference, the fuzzified decision to determine the action is demonstrated in this paper. (author)

  3. Modified and fuzzified general problem solver for the 'monkey and banana' problem, 1

    International Nuclear Information System (INIS)

    Sano, Norihide; Takahashi, Ryoichi.

    1991-01-01

    The master-and-slave control system should be extensively implemented for the in-service inspection of operating nuclear power stations or the decommission of retired plants. The performance of this system depends on the intelligent slave. In this paper the degree of intelligence is approximated by the given amount of prior knowledge or suggestions. This paper aims at improving the general problem solver (GPS) by incorporating the learning process in order to solve the puzzle of the 'monkey and banana'. The monkey in this puzzle may be a reasonable alternative to represent the intelligent slave. Also, this paper deals with fuzzified problem solving since the master's command is not always crisp to the slave. (author)

  4. Some problems in generalized electromagnetic thermoelasticity and wave propagation

    International Nuclear Information System (INIS)

    Mohamed, S.E.S.

    2012-01-01

    The first chapter contains a review of the classical theory of elasticity, the theory of thermodynamics, the theory of uncoupled thermoelasticity, the coupled theory of thermoelasticity, the generalized theory of thermoelasticity with one relaxation time, electromagneto thermoelasticity and an introduction to wave propagation in elastic media. Chapter two is devoted to the study of wave propagation for a problem of an infinitely long solid conducting circular cylinder whose lateral surface is traction free and subjected to a known surrounding temperatures in the presence of a uniform magnetic field in the direction of the axis of the cylinder. Laplace transform techniques are used to derive the solution in the Laplace transform domain. The inversion process is carried out using asymptotic expansions valid for short tines. Numerical results are computed for the temperature, displacement, stress,induced magnetic field and induced electric field distributions. The chapter contains also a study of the wave propagation in the elastic medium. In chapter three, we consider the two-dimensional problem of an infinitely long conducting solid cylinder. The lateral surface of the cylinder is taken to be traction free and is subjected to a known temperature distribution independent of z in the presence of a uniform magnetic field in the direction of the axis of the cylinder. Laplace transform techniques are used. The inversion process is carried out using a numerical method based on Fourier series expansions. Numerical results are computed and represented graphically. The chapter contains also a study of the wave propagation in the elastic medium. In chapter four, we consider a two-dimensional problem for an infinity long cylinder. The lateral surface of the cylinder is taken to be traction free and is subjected to a known temperature distribution independent of φ in the presence of a uniform electric field in the direction of the binomial of the cylinder axis. Laplace and

  5. Limited Data Problems for the Generalized Radon Transform in Rn

    DEFF Research Database (Denmark)

    Frikel, Jürgen; Quinto, Eric Todd

    2016-01-01

    We consider the generalized Radon transform (defined in terms of smooth weight functions) on hyperplanes in Rn. We analyze general filtered backprojection type reconstruction methods for limited data with filters given by general pseudodifferential operators. We provide microlocal characterizations...

  6. Abstract generalized vector quasi-equilibrium problems in noncompact Hadamard manifolds

    Directory of Open Access Journals (Sweden)

    Haishu Lu

    2017-05-01

    Full Text Available Abstract This paper deals with the abstract generalized vector quasi-equilibrium problem in noncompact Hadamard manifolds. We prove the existence of solutions to the abstract generalized vector quasi-equilibrium problem under suitable conditions and provide applications to an abstract vector quasi-equilibrium problem, a generalized scalar equilibrium problem, a scalar equilibrium problem, and a perturbed saddle point problem. Finally, as an application of the existence of solutions to the generalized scalar equilibrium problem, we obtain a weakly mixed variational inequality and two mixed variational inequalities. The results presented in this paper unify and generalize many known results in the literature.

  7. A General Theory of Markovian Time Inconsistent Stochastic Control Problems

    DEFF Research Database (Denmark)

    Björk, Tomas; Murgochi, Agatha

    We develop a theory for stochastic control problems which, in various ways, are time inconsistent in the sense that they do not admit a Bellman optimality principle. We attach these problems by viewing them within a game theoretic framework, and we look for Nash subgame perfect equilibrium points...... examples of time inconsistency in the literature are easily seen to be special cases of the present theory. We also prove that for every time inconsistent problem, there exists an associated time consistent problem such that the optimal control and the optimal value function for the consistent problem...

  8. SOCIAL NETWORK OPTIMIZATION A NEW METHAHEURISTIC FOR GENERAL OPTIMIZATION PROBLEMS

    Directory of Open Access Journals (Sweden)

    Hassan Sherafat

    2017-12-01

    Full Text Available In the recent years metaheuristics were studied and developed as powerful technics for hard optimization problems. Some of well-known technics in this field are: Genetic Algorithms, Tabu Search, Simulated Annealing, Ant Colony Optimization, and Swarm Intelligence, which are applied successfully to many complex optimization problems. In this paper, we introduce a new metaheuristic for solving such problems based on social networks concept, named as Social Network Optimization – SNO. We show that a wide range of np-hard optimization problems may be solved by SNO.

  9. Institutional Problems and Solutions of General Education in Chinese Universities

    Science.gov (United States)

    Meng, Weiqing; Huang, Wei

    2018-01-01

    Embedding general education in the Chinese university education system is a considerably complex systemic project, and a lack of institutional arrangements beneficial to general education has always been a key barrier in implementation. Currently, the main institutional restricting factors for university general education include substantial…

  10. Spatial Transformation of Equality – Generalized Travelling Salesman Problem to Travelling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Mohammed Zia

    2018-03-01

    Full Text Available The Equality-Generalized Travelling Salesman Problem (E-GTSP, which is an extension of the Travelling Salesman Problem (TSP, is stated as follows: given groups of points within a city, like banks, supermarkets, etc., find a minimum cost Hamiltonian cycle that visits each group exactly once. It can model many real-life combinatorial optimization scenarios more efficiently than TSP. This study presents five spatially driven search-algorithms for possible transformation of E-GTSP to TSP by considering the spatial spread of points in a given urban city. Presented algorithms are tested over 15 different cities, classified by their street-network’s fractal-dimension. Obtained results denote that the R-Search algorithm, which selects the points from each group based on their radial separation with respect to the start–end point, is the best search criterion for any E-GTSP to TSP conversion modelled for a city street network. An 8.8% length error has been reported for this algorithm.

  11. Investigating the Problem of Skill Generalization: Literature Review III.

    Science.gov (United States)

    Haring, Norris

    The third in a series of literature reviews, this monograph presents three articles on skill generalization among individuals with severe disabilities. Kathleen A. Liberty analyzes the results of 15 studies to determine how teaching self-control affected students' performance in training and generalization, "Behavior-Control of Stimulus Events to…

  12. A branch-and-cut-and-price algorithm for the mixed capacitated general routing problem

    DEFF Research Database (Denmark)

    Bach, Lukas; Wøhlk, Sanne; Lysgaard, Jens

    2016-01-01

    In this paper, we consider the Mixed Capacitated General Routing Problem which is a combination of the Capacitated Vehicle Routing Problem and the Capacitated Arc Routing Problem. The problem is also known as the Node, Edge, and Arc Routing Problem. We propose a Branch-and-Cut-and-Price algorithm...

  13. On generalizations of network design problems with degree bounds

    NARCIS (Netherlands)

    Bansal, N.; Khandekar, R.; Könemann, J.; Nagarajan, V.; Peis, B.

    2013-01-01

    Iterative rounding and relaxation have arguably become the method of choice in dealing with unconstrained and constrained network design problems. In this paper we extend the scope of the iterative relaxation method in two directions: (1) by handling more complex degree constraints in the minimum

  14. On generalizations of network design problems with degree bounds

    NARCIS (Netherlands)

    N. Bansal (Nikhil); R. Khandekar; J. Könemann (Jochen); V. Nagarajan; B. Peis

    2013-01-01

    htmlabstractIterative rounding and relaxation have arguably become the method of choice in dealing with unconstrained and constrained network design problems. In this paper we extend the scope of the iterative relaxation method in two directions: (1) by handling more complex degree constraints in

  15. Optimal portfolio selection for general provisioning and terminal wealth problems

    NARCIS (Netherlands)

    van Weert, K.; Dhaene, J.; Goovaerts, M.

    2010-01-01

    In Dhaene et al. (2005), multiperiod portfolio selection problems are discussed, using an analytical approach to find optimal constant mix investment strategies in a provisioning or a savings context. In this paper we extend some of these results, investigating some specific, real-life situations.

  16. Optimal portfolio selection for general provisioning and terminal wealth problems

    NARCIS (Netherlands)

    van Weert, K.; Dhaene, J.; Goovaerts, M.

    2009-01-01

    In Dhaene et al. (2005), multiperiod portfolio selection problems are discussed, using an analytical approach to find optimal constant mix investment strategies in a provisioning or savings context. In this paper we extend some of these results, investigating some specific, real-life situations. The

  17. On a problem of Berenstein-Gay and its generalizations

    International Nuclear Information System (INIS)

    Volchkov, Valerii V; Volchkov, Vitaly V

    2010-01-01

    We obtain a solution of the Berenstein-Gay problem on the local analogue of spectral analysis on Riemannian symmetric spaces X of rank 1. The proof is based on constructing transmutation maps connected with eigenfunction expansions of the Laplace-Beltrami operator on X.

  18. Contribution of radiobiology to the problem of general fitness

    International Nuclear Information System (INIS)

    Vacha, J.

    1976-01-01

    On the basis of the present scarce literary data it can be taken as proved that between the numerous properties of the organism usually considered as biologically valuable (high fertility, longevity, higher body weight, resistance to fasting, radiation, and infection agents, certain favorable parameters of CNS) there exist many single and multiple positive correlations. The existence of these correlations allows for the introduction of the working concept of general fitness, stimulating further interdisciplinary research in this field important both in practice and theory. Most correlated manifestations of fitness demonstrated a masked influence of the organism's genotype even though the manner of this manifestation on the phenotype level remains considerably obscure. The efficiency of the haematopoietic system is doubtless one of the mechanisms of general fitness; it is determined by the very complex coordination of several cytokinetic parameters. Important factors are the efficiency of regulation mechanisms at CNS level, the endocrine system, and the regulators of cell populations. Generally highest fitness is connected with a ''balanced'' regulation type, which is characterized by optimal activation of the homeostatic regulation mechanism. In studying the causes of general fitness a systems approach is inevitable which evaluates the levels of individual factors not ''mechanically'' or linearly but from the point of view of the needs of the whole organism and with the application of concepts established by the systems theory (e.g. by the theory of automatic regulation). The sensitivity of an organism to irradiation with ionizing radiation turns out to be a suitable criterion of its general fitness. (author)

  19. Infrared problems in two-dimensional generalized σ-models

    International Nuclear Information System (INIS)

    Curci, G.; Paffuti, G.

    1989-01-01

    We study the correlations of the energy-momentum tensor for classically conformally invariant generalized σ-models in the Wilson operator-product-expansion approach. We find that these correlations are, in general, infrared divergent. The absence of infrared divergences is obtained, as one can expect, for σ-models on a group manifold or for σ-models with a string-like interpretation. Moreover, the infrared divergences spoil the naive scaling arguments used by Zamolodchikov in the demonstration of the C-theorem. (orig.)

  20. The global existence problem and cosmic censorship in general relativity

    International Nuclear Information System (INIS)

    Moncrief, V.; Eardley, D.M.

    1981-01-01

    Two global existence conjectures for the Einstein equations are formulated and their relevance to the cosmic censorship conjecture discussed. It is argued that the reformulation of the cosmic censorship conjecture as a global existence problem renders it more amenable to direct analytical attack. To demonstrate the facility of this approach the cosmological version of the global existence conjecture is proved for the Gowdy spacetimes on T 3 X R. (author)

  1. General problems of dynamics and control of vibratory gyroscopes

    CSIR Research Space (South Africa)

    Shatalov, MY

    2008-05-01

    Full Text Available A general model of operation of vibratory gyroscopes, which is applicable to a broad class of instruments, including cylindrical, disc and micro-machined gyros, is formulated on the basis of analysis of dynamics and control of a hemispherical...

  2. General Systems Theory Approaches to Organizations: Some Problems in Application

    Science.gov (United States)

    Peery, Newman S., Jr.

    1975-01-01

    Considers the limitations of General Systems Theory (GST) as a major paradigm within administrative theory and concludes that most systems formulations overemphasize growth and show little appreciation for intraorganizational conflict, diversity of values, and political action within organizations. Suggests that these limitations are mainly due to…

  3. The problem of diagnostic variability in general practice.

    Science.gov (United States)

    Crombie, D L; Cross, K W; Fleming, D M

    1992-08-01

    The aim was to examine the scale, source, and relevance of variation between general practices in respect of the rates with which patients consulted with illnesses falling in each of several diagnostic groups. This study involved a general practice morbidity survey conducted over two years, 1970-72. All patients who consulted their general practitioners were identified and the number of these who consulted with diagnoses attributable to each of the 18 main chapters of the International classification of diseases were counted. Patients who consulted for more than one diagnosis within a chapter were counted once only; those who consulted for one or more diagnoses in each of several chapters were counted once for each chapter. This was a national survey involving general practitioners in England and Wales. The study involved 214,524 patients from 53 selected general practices (115 doctors) who were registered with their general practitioners for the whole of the year 1970-71 and for whom their morbidity data had been linked with their social data from the 1971 census. Using the numbers of patients on the practice lists as denominators, practice patient consulting rates (PPCR) were calculated for each practice and for each ICD chapter. Variability in chapter PPCR was examined by calculating coefficients of variation and, after allowance for random variation, coefficients of residual variation. There were large interpractice (doctor) variations in all chapter rates. These variations were only marginally attributable to: chance; different age, sex and social class mixes of practice populations; geographical locations; and practice organisation. The rates were, however, consistent from one year to the next for any one practice. Approximately half of the interpractice (doctor) diagnostic variability was associated with overall patient consulting behaviour. When the effects of this behaviour were discounted, any major residual diagnostic variability was confined largely to

  4. Neurotoxicity of general anesthetics: A modern view of the problem

    Directory of Open Access Journals (Sweden)

    A. M. Ovezov

    2015-01-01

    Full Text Available All general anesthetics routinely used in clinical practice are noted to have a neurotoxic effect on the brain in different animal species including primates. The negative effects observed both in young and sexually mature animals include apoptotic neuronal cell death, suppression of neurogenesis and gliogenesis, neuroinflammation, as well as learning and memory impairments. A number of epidemiologic surveys have established an association between anesthesia in patients younger than 3 to 4 years and subsequent learning disabilities and language disorders whereas others have not found this link. In middle-aged and elderly patients, anesthesia is frequently associated with the development of postoperative cognitive dysfunction. The key component of its pathogenesis (general anesthesia itself or other factors, such as operative injury, an inflammatory response, pain syndrome, intraoperative complications, underlying disease in a patient remains unelucidated. It is concluded that there is a need for additional experimental and clinical studies of the pathogenesis of these undesirable phenomena to be prevented and corrected.

  5. Structure of the generalized momentum of a test charged particle and the inverse problem in general relativity theory

    International Nuclear Information System (INIS)

    Zakharov, A.V.; Singatullin, R.S.

    1981-01-01

    The inverse problem is solved in general relativity theory (GRT) consisting in determining the metric and potentials of an electromagnetic field by their values in the nonsingular point of the V 4 space and present functions, being the generalized momenta of a test charged particle. The Hamilton-Jacobi equation for a test charged particle in GRT is used. The general form of the generalized momentum dependence on the initial values is determined. It is noted that the inverse problem solution of dynamics in GRT contains arbitrariness which depends on the choice of the metric and potential values of the electromagnetic field in the nonsingular point [ru

  6. General principles of neurotransmitter detection. Problems and application to catecholamines

    International Nuclear Information System (INIS)

    Taxi, Jacques

    1976-01-01

    The use of radioautography for neurotransmitter studies requires two preliminary conditions (in addition to the availability of tritiated molecules): there must be a selective uptake of the neurotransmitter itself, or of a related substance (precursor or false transmitter); the labelled substance must be preserved in situ by fixation and must not be removed by further treatments. Since the putative neurotransmitters are generally small, hydrosoluble molecules, they can be maintained in situ only if they are bound to structure made insoluble by the fixative. The technical indications are summarized so that the successive stages of experimentation can be considered in an attempt to answer the major questions posed by the experimenter

  7. Solving the generalized symmetric eigenvalue problem using tile algorithms on multicore architectures

    KAUST Repository

    Ltaief, Hatem; Luszczek, Piotr R.; Haidar, Azzam; Dongarra, Jack

    2012-01-01

    This paper proposes an efficient implementation of the generalized symmetric eigenvalue problem on multicore architecture. Based on a four-stage approach and tile algorithms, the original problem is first transformed into a standard symmetric

  8. The workload of general practitioners does not affect their awareness of patients' psychological problems.

    NARCIS (Netherlands)

    Zantinge, E.M.; Verhaak, P.F.M.; Bakker, D.H. de; Kerssens, J.J.; Meer, K. van der; Bensing, J.M.

    2007-01-01

    OBJECTIVE: To investigate if general practitioners (GPs) with a higher workload are less inclined to encourage their patients to disclose psychological problems, and are less aware of their patients' psychological problems. METHODS: Data from 2095 videotaped consultations from a representative

  9. General problems specific to hot nuclear materials research facilities

    International Nuclear Information System (INIS)

    Bart, G.

    1996-01-01

    During the sixties, governments have installed hot nuclear materials research facilities to characterize highly radioactive materials, to describe their in-pile behaviour, to develop and test new reactor core components, and to provide the industry with radioisotopes. Since then, the attitude towards the nuclear option has drastically changed and resources have become very tight. Within the changed political environment, the national research centres have defined new objectives. Given budgetary constraints, nuclear facilities have to co-operate internationally and to look for third party research assignments. The paper discusses the problems and needs within experimental nuclear research facilities as well as industrial requirements. Special emphasis is on cultural topics (definition of the scope of nuclear research facilities, the search for competitive advantages, and operational requirements), social aspects (overageing of personnel, recruitment, and training of new staff), safety related administrative and technical issues, and research needs for expertise and state of the art analytical infrastructure

  10. General review on climate change problems: causes, potential effects

    International Nuclear Information System (INIS)

    Martellet, J.

    1991-01-01

    Greenhouse gases and greenhouse effect principles are reviewed and climate changes due to the human activities are discussed: identification of gases, human or natural causes, composition evolution in the atmosphere and relative roles of greenhouse gases. The various tools and calculations methods for evaluating the climate change due to greenhouse effect are presented. Several problems are stated: evolution of the climate structure in 2030, variations of the climatic extremes and the extreme phenomena, augmentation or diminution of the storms on a warmed planet, long term evolution of the climate. Some consequences of a climate change are reviewed: sea level raising, climate change effects on ecosystems. Precision and validity of these predictions are discussed; recommendations for diminishing the uncertainties are proposed

  11. On a covariant 2+2 formulation of the initial value problem in general relativity

    International Nuclear Information System (INIS)

    Smallwood, J.

    1980-03-01

    The initial value problems in general relativity are considered from a geometrical standpoint with especial reference to the development of a covariant 2+2 formalism in which space-time is foliated by space-like 2-surfaces under the headings; the Cauchy problem in general relativity, the covariant 3+1 formulation of the Cauchy problem, characteristic and mixed initial value problems, on locally imbedding a family of null hypersurfaces, the 2+2 formalism, the 2+2 formulation of the Cauchy problem, the 2+2 formulation of the characteristic and mixed initial value problems, and a covariant Lagrangian 2+2 formulation. (U.K.)

  12. Generalized multivalued equilibrium-like problems: auxiliary principle technique and predictor-corrector methods

    Directory of Open Access Journals (Sweden)

    Vahid Dadashi

    2016-02-01

    Full Text Available Abstract This paper is dedicated to the introduction a new class of equilibrium problems named generalized multivalued equilibrium-like problems which includes the classes of hemiequilibrium problems, equilibrium-like problems, equilibrium problems, hemivariational inequalities, and variational inequalities as special cases. By utilizing the auxiliary principle technique, some new predictor-corrector iterative algorithms for solving them are suggested and analyzed. The convergence analysis of the proposed iterative methods requires either partially relaxed monotonicity or jointly pseudomonotonicity of the bifunctions involved in generalized multivalued equilibrium-like problem. Results obtained in this paper include several new and known results as special cases.

  13. General solution to the E-B mixing problem

    International Nuclear Information System (INIS)

    Smith, Kendrick M.; Zaldarriaga, Matias

    2007-01-01

    We derive a general ansatz for optimizing pseudo-C l estimators used to measure cosmic microwave background anisotropy power spectra, and apply it to the recently proposed pure pseudo-C l formalism, to obtain an estimator which achieves near-optimal B-mode power spectrum errors for any specified noise distribution while minimizing leakage from ambiguous modes. Our technique should be relevant for upcoming cosmic microwave background polarization experiments searching for B-mode polarization. We compare our technique both to the theoretical limits based on a full Fisher matrix calculation and to the standard pseudo-C l technique. We demonstrate it by applying it to a fiducial survey with realistic inhomogeneous noise, complex boundaries, point source masking, and a noise level comparable to what is expected for next-generation experiments (∼5.75 μK-arcmin). For such an experiment our technique could improve the constraints on the amplitude of a gravity wave background by over a factor of 10 compared to what could be obtained using ordinary pseudo-C l , coming quite close to saturating the theoretical limit. Constraints on the amplitude of the lensing B-modes are improved by about a factor of 3

  14. Generalized information theory: aims, results, and open problems

    International Nuclear Information System (INIS)

    Klir, George J.

    2004-01-01

    The principal purpose of this paper is to present a comprehensive overview of generalized information theory (GIT): a research program whose objective is to develop a broad treatment of uncertainty-based information, not restricted to classical notions of uncertainty. After a brief overview of classical information theories, a broad framework for formalizing uncertainty and the associated uncertainty-based information of a great spectrum of conceivable types is sketched. The various theories of imprecise probabilities that have already been developed within this framework are then surveyed, focusing primarily on some important unifying principles applying to all these theories. This is followed by introducing two higher levels of the theories of imprecise probabilities: (i) the level of measuring the amount of relevant uncertainty (predictive, retrodictive, prescriptive, diagnostic, etc.) in any situation formalizable in each given theory, and (ii) the level of some methodological principles of uncertainty, which are contingent upon the capability to measure uncertainty and the associated uncertainty-based information. Various issues regarding both the measurement of uncertainty and the uncertainty principles are discussed. Again, the focus is on unifying principles applicable to all the theories. Finally, the current status of GIT is assessed and future research in the area is discussed

  15. Examination of Turkish Junior High-School Students' Perceptions of the General Problem-Solving Process

    Science.gov (United States)

    Ekici, Didem Inel

    2016-01-01

    This study aimed to determine Turkish junior high-school students' perceptions of the general problem-solving process. The Turkish junior high-school students' perceptions of the general problem-solving process were examined in relation to their gender, grade level, age and their grade point with regards to the science course identified in the…

  16. A General Iterative Method of Fixed Points for Mixed Equilibrium Problems and Variational Inclusion Problems

    Directory of Open Access Journals (Sweden)

    Phayap Katchang

    2010-01-01

    Full Text Available The purpose of this paper is to investigate the problem of finding a common element of the set of solutions for mixed equilibrium problems, the set of solutions of the variational inclusions with set-valued maximal monotone mappings and inverse-strongly monotone mappings, and the set of fixed points of a family of finitely nonexpansive mappings in the setting of Hilbert spaces. We propose a new iterative scheme for finding the common element of the above three sets. Our results improve and extend the corresponding results of the works by Zhang et al. (2008, Peng et al. (2008, Peng and Yao (2009, as well as Plubtieng and Sriprad (2009 and some well-known results in the literature.

  17. Markov chains with exponentially small transition probabilities: First exit problem from a general domain. II. The general case

    International Nuclear Information System (INIS)

    Olivieri, E.; Scoppola, E.

    1996-01-01

    In this paper we consider aperiodic ergodic Markov chains with transition probabilities exponentially small in a large parameter β. We extend to the general, not necessarily reversible case the analysis, started in part I of this work, of the first exit problem from a general domain Q containing many stable equilibria (attracting equilibrium points for the β = ∞ dynamics). In particular we describe the tube of typical trajectories during the first excursion outside Q

  18. Multistep Hybrid Iterations for Systems of Generalized Equilibria with Constraints of Several Problems

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We first introduce and analyze one multistep iterative algorithm by hybrid shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: the generalized mixed equilibrium problem, finitely many variational inclusions, the minimization problem for a convex and continuously Fréchet differentiable functional, and the fixed-point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another multistep iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions.

  19. General volumes in the Orlicz-Brunn-Minkowski theory and a related Minkowski Problem I

    OpenAIRE

    Gardner, Richard J.; Hug, Daniel; Weil, Wolfgang; Xing, Sudan; Ye, Deping

    2018-01-01

    The general volume of a star body, a notion that includes the usual volume, the $q$th dual volumes, and many previous types of dual mixed volumes, is introduced. A corresponding new general dual Orlicz curvature measure is defined that specializes to the $(p,q)$-dual curvature measures introduced recently by Lutwak, Yang, and Zhang. General variational formulas are established for the general volume of two types of Orlicz linear combinations. One of these is applied to the Minkowski problem f...

  20. A Rule-Based Local Search Algorithm for General Shift Design Problems in Airport Ground Handling

    DEFF Research Database (Denmark)

    Clausen, Tommy

    We consider a generalized version of the shift design problem where shifts are created to cover a multiskilled demand and fit the parameters of the workforce. We present a collection of constraints and objectives for the generalized shift design problem. A local search solution framework with mul......We consider a generalized version of the shift design problem where shifts are created to cover a multiskilled demand and fit the parameters of the workforce. We present a collection of constraints and objectives for the generalized shift design problem. A local search solution framework...... with multiple neighborhoods and a loosely coupled rule engine based on simulated annealing is presented. Computational experiments on real-life data from various airport ground handling organization show the performance and flexibility of the proposed algorithm....

  1. Effects of conventional and problem-based learning on clinical and general competencies and career development

    NARCIS (Netherlands)

    Cohen-Schotanus, Janke; Muijtjens, Arno M. M.; Schonrock-Adema, Johanna; Geertsma, Jelle; van der Vleuten, Cees P. M.

    OBJECTIVE: To test hypotheses regarding the longitudinal effects of problem-based learning (PBL) and conventional learning relating to students' appreciation of the curriculum, self-assessment of general competencies, summative assessment of clinical competence and indicators of career development.

  2. Generalized ladder operators for the Dirac-Coulomb problem via SUSY QM

    International Nuclear Information System (INIS)

    Rodrigues, R. de Lima; Universidade Federal de Campina Grande, PB

    2003-12-01

    The supersymmetry in quantum mechanics and shape invariance condition are applied as an algebraic method to solving the Dirac-Coulomb problem. The ground state and the excited states are investigated via new generalized ladder operators. (author)

  3. PowerPlay: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem.

    Science.gov (United States)

    Schmidhuber, Jürgen

    2013-01-01

    Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. Given a general problem-solving architecture, at any given time, the novel algorithmic framework PowerPlay (Schmidhuber, 2011) searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Newly invented tasks may require to achieve a wow-effect by making previously learned skills more efficient such that they require less time and space. New skills may (partially) re-use previously learned skills. The greedy search of typical PowerPlay variants uses time-optimal program search to order candidate pairs of tasks and solver modifications by their conditional computational (time and space) complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. This biases the search toward pairs that can be described compactly and validated quickly. The computational costs of validating new tasks need not grow with task repertoire size. Standard problem solver architectures of personal computers or neural networks tend to generalize by solving numerous tasks outside the self-invented training set; PowerPlay's ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Gödel's sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing

  4. A Study of Some General Problems of Dieudonné-Rashevski Type

    Directory of Open Access Journals (Sweden)

    Ariana Pitea

    2012-01-01

    Full Text Available We use a method of investigation based on employing adequate variational calculus techniques in the study of some generalized Dieudonné-Rashevski problems. This approach allows us to state and prove optimality conditions for such kind of vector multitime variational problems, with mixed isoperimetric constraints. We state and prove efficiency conditions and develop a duality theory.

  5. Consultation for and identification of child and adolescent psychological problems in Dutch general practice.

    NARCIS (Netherlands)

    Zwaanswijk, M.; Verhaak, P.F.M.; Ende, J. van der; Bensing, J.M.; Verhulst, F.C.

    2005-01-01

    BACKGROUND: Child and adolescent psychological problems are rarely brought to the attention of GPs. Children and adolescents with psychological problems who do visit their GP are seldom identified as such by GPs. OBJECTIVE: To investigate in a general population sample of 2,449 Dutch children and

  6. General conditions guaranteeing the solvability of the Cauchy problem for functional differential equations

    Czech Academy of Sciences Publication Activity Database

    Dilna, N.; Rontó, András

    2008-01-01

    Roč. 133, č. 4 (2008), s. 435-445 ISSN 0862-7959 R&D Projects: GA ČR(CZ) GA201/06/0254 Institutional research plan: CEZ:AV0Z10190503 Keywords : functional differential equation * Cauchy problem * initial value problem * differential inequality Subject RIV: BA - General Mathematics

  7. The wetted solid---A generalization of the Plateau problem and its implications for sintered materials

    International Nuclear Information System (INIS)

    Salamon, P.; Bernholc, J.; Berry, R.S.; Carrera-Patino, M.E.; Andresen, B.

    1990-01-01

    A new generalization of the Plateau problem that includes the constraint of enclosing a given region is introduced. Physically, the problem is important insofar as it bears on sintering processes and the structure of wetted porous media. Some primal and dual characterizations of the solutions are offered and aspects of the problem are illustrated in one and two dimensions in order to clarify the combinatorial elements and demonstrate the importance of numerous local minima

  8. The wetted solid - a generalization of Plateau's problem and its implications for sintered materials

    International Nuclear Information System (INIS)

    Salomon, P.; Berry, R.S.; Carrera-Patino, M.E.; Chicago Univ., IL; Andresen, B.

    1988-01-01

    We introduce a new generalization of the Plateau problem which includes the constraint of enclosing a given region. Physically the problem is important insofar as it bears on sintering processes and on the structure of wetted porous media. Some primal and dual characterizations of the solutions are offered, and aspects of the problem are illustrated in one and two dimensions in order to clarify the combinatorial elements and to demonstrate the importance of numerous local minima. (orig.)

  9. Consultations for mental problems in general practices with and without mental health nurses.

    NARCIS (Netherlands)

    Magnée, T.; Beurs, D. de; Verhaak, P.

    2016-01-01

    Background & Aim: It seems cost-effective to provide mental health care to patient with mild mental problems in general practices instead of in specialized care, but general practitioners (GPs) often lack time or expertise. Since 2008, Dutch GPs have been collaborating with nurses with mental health

  10. Reduction of the general Spitzer-Haerm problem in plasma physics

    International Nuclear Information System (INIS)

    Ferreira, A.

    1988-01-01

    The general Spitzer-Haerm problem is unfolded through a redefinition of the dependent variable into two separate simpler problems. The first takes the form of a second order differential equation, and the second, that of an integration over the solution of the first problem, which provides the distribution function or, directly, the current and the heat flow. It is shown that the current and the heat flow can in general by synthesized from the solutions of the differential equation for two specific forms of the driving term. (author)

  11. Generalizing the classical fixed-centres problem in a non-Hamiltonian way

    International Nuclear Information System (INIS)

    Albouy, A; Stuchi, T J

    2004-01-01

    The problem of two gravitational (or Coulombian) fixed centres is a classical integrable problem, stated and integrated by Euler in 1760. The integrability is due to the unexpected first integral G. We introduce some straightforward generalizations of the problem that still have the generalization of G as a first integral, but do not possess the energy integral. We present some numerical integrations showing the main features of their dynamics. In the domain of bounded orbits the behaviour of these a priori non-Hamiltonian systems is very similar to the behaviour of usual near-integrable systems

  12. The Implementation of Physics Problem Solving Strategy Combined with Concept Map in General Physics Course

    Science.gov (United States)

    Hidayati, H.; Ramli, R.

    2018-04-01

    This paper aims to provide a description of the implementation of Physic Problem Solving strategy combined with concept maps in General Physics learning at Department of Physics, Universitas Negeri Padang. Action research has been conducted in two cycles where each end of the cycle is reflected and improved for the next cycle. Implementation of Physics Problem Solving strategy combined with concept map can increase student activity in solving general physics problem with an average increase of 15% and can improve student learning outcomes from 42,7 in the cycle I become 62,7 in cycle II in general physics at the Universitas Negeri Padang. In the future, the implementation of Physic Problem Solving strategy combined with concept maps will need to be considered in Physics courses.

  13. Algebraic structures in generalized Clifford analysis and applications to boundary value problems

    Directory of Open Access Journals (Sweden)

    José Játem

    2015-12-01

    Full Text Available The present article has a threefold purpose: First it is a survey of the algebraic structures of generalized Clifford-type algebras and shows the main results of the corresponding Clifford-type analysis and its application to boundary value problems known so far. Second it is aimed to implement algorithms to provide the fast and accurate computation of boundary value problems for inhomogeneous equations in the framework of the generalized Clifford analysis. Finally it is also aimed to encourage the development of a generalized discrete Clifford analysis.

  14. An efficient method for generalized linear multiplicative programming problem with multiplicative constraints.

    Science.gov (United States)

    Zhao, Yingfeng; Liu, Sanyang

    2016-01-01

    We present a practical branch and bound algorithm for globally solving generalized linear multiplicative programming problem with multiplicative constraints. To solve the problem, a relaxation programming problem which is equivalent to a linear programming is proposed by utilizing a new two-phase relaxation technique. In the algorithm, lower and upper bounds are simultaneously obtained by solving some linear relaxation programming problems. Global convergence has been proved and results of some sample examples and a small random experiment show that the proposed algorithm is feasible and efficient.

  15. Vol. 1: Physics of Elementary Particles and Quantum Field Theory. General Problems

    International Nuclear Information System (INIS)

    Sitenko, A.

    1993-01-01

    Problems of modern physics and the situation with physical research in Ukraine are considered. Programme of the conference includes scientific and general problems. Its proceedings are published in 6 volumes. The papers presented in this volume refer to elementary particle physics and quantum field theory. The main attention is paid to the following problems: - development of science in Ukraine and its role in the state structures; - modern state of scientific research in Ukraine; - education and training of specialists; - history of Ukrainian physics and contribution of Ukrainian scientists in the world science; - problems of the Ukrainian scientific terminology

  16. Psychological and social problems in primary care patients - general practitioners' assessment and classification.

    Science.gov (United States)

    Rosendal, Marianne; Vedsted, Peter; Christensen, Kaj Sparle; Moth, Grete

    2013-03-01

    To estimate the frequency of psychological and social classification codes employed by general practitioners (GPs) and to explore the extent to which GPs ascribed health problems to biomedical, psychological, or social factors. A cross-sectional survey based on questionnaire data from GPs. Setting. Danish primary care. 387 GPs and their face-to-face contacts with 5543 patients. GPs registered consecutive patients on registration forms including reason for encounter, diagnostic classification of main problem, and a GP assessment of biomedical, psychological, and social factors' influence on the contact. The GP-stated reasons for encounter largely overlapped with their classification of the managed problem. Using the International Classification of Primary Care (ICPC-2-R), GPs classified 600 (11%) patients with psychological problems and 30 (0.5%) with social problems. Both codes for problems/complaints and specific disorders were used as the GP's diagnostic classification of the main problem. Two problems (depression and acute stress reaction/adjustment disorder) accounted for 51% of all psychological classifications made. GPs generally emphasized biomedical aspects of the contacts. Psychological aspects were given greater importance in follow-up consultations than in first-episode consultations, whereas social factors were rarely seen as essential to the consultation. Psychological problems are frequently seen and managed in primary care and most are classified within a few diagnostic categories. Social matters are rarely considered or classified.

  17. Two Efficient Generalized Laguerre Spectral Algorithms for Fractional Initial Value Problems

    Directory of Open Access Journals (Sweden)

    D. Baleanu

    2013-01-01

    Full Text Available We present a direct solution technique for approximating linear multiterm fractional differential equations (FDEs on semi-infinite interval, using generalized Laguerre polynomials. We derive the operational matrix of Caputo fractional derivative of the generalized Laguerre polynomials which is applied together with generalized Laguerre tau approximation for implementing a spectral solution of linear multiterm FDEs on semi-infinite interval subject to initial conditions. The generalized Laguerre pseudo-spectral approximation based on the generalized Laguerre operational matrix is investigated to reduce the nonlinear multiterm FDEs and its initial conditions to nonlinear algebraic system, thus greatly simplifying the problem. Through several numerical examples, we confirm the accuracy and performance of the proposed spectral algorithms. Indeed, the methods yield accurate results, and the exact solutions are achieved for some tested problems.

  18. A Projection free method for Generalized Eigenvalue Problem with a nonsmooth Regularizer.

    Science.gov (United States)

    Hwang, Seong Jae; Collins, Maxwell D; Ravi, Sathya N; Ithapu, Vamsi K; Adluru, Nagesh; Johnson, Sterling C; Singh, Vikas

    2015-12-01

    Eigenvalue problems are ubiquitous in computer vision, covering a very broad spectrum of applications ranging from estimation problems in multi-view geometry to image segmentation. Few other linear algebra problems have a more mature set of numerical routines available and many computer vision libraries leverage such tools extensively. However, the ability to call the underlying solver only as a "black box" can often become restrictive. Many 'human in the loop' settings in vision frequently exploit supervision from an expert, to the extent that the user can be considered a subroutine in the overall system. In other cases, there is additional domain knowledge, side or even partial information that one may want to incorporate within the formulation. In general, regularizing a (generalized) eigenvalue problem with such side information remains difficult. Motivated by these needs, this paper presents an optimization scheme to solve generalized eigenvalue problems (GEP) involving a (nonsmooth) regularizer. We start from an alternative formulation of GEP where the feasibility set of the model involves the Stiefel manifold. The core of this paper presents an end to end stochastic optimization scheme for the resultant problem. We show how this general algorithm enables improved statistical analysis of brain imaging data where the regularizer is derived from other 'views' of the disease pathology, involving clinical measurements and other image-derived representations.

  19. The association between childhood autistic traits and adolescent psychotic experiences is explained by general neuropsychiatric problems.

    Science.gov (United States)

    Cederlöf, Martin; Pettersson, Erik; Sariaslan, Amir; Larsson, Henrik; Östberg, Per; Kelleher, Ian; Långström, Niklas; Gumpert, Clara Hellner; Lundström, Sebastian; Lichtenstein, Paul

    2016-03-01

    Studies suggest associations between childhood autistic traits and adolescent psychotic experiences. However, recent research suggests that a general neuropsychiatric problems factor predicts adverse outcomes better than specific diagnostic entities. To examine if the alleged association between autistic traits and psychotic experiences could rather be explained by a general neuropsychiatric problems factor comprising symptoms of ADHD, tic disorder, developmental coordination disorder, and learning disorder, we conducted a prospective cohort study based on the Child and Adolescent Twin Study in Sweden. In addition, we examined the genetic and environmental influences on the associations. A total of 9,282 twins with data on childhood autistic traits and other neuropsychiatric problems, and follow-up data on psychotic experiences at ages 15 and/or 18 years were included. First, psychotic experiences were regressed on autistic traits and second, the general neuropsychiatric problems factor was added to the model. Auditory hallucinations were analyzed separately from the other psychotic experiences. Finally, twin analyses were employed to disentangle genetic from environmental influences in the observed associations. Replicating prior research, significant associations were found between autistic traits in childhood and auditory hallucinations at ages 15 and 18. However, after controlling for the general neuropsychiatric problems factor, the associations between autistic traits and auditory hallucinations disappeared, whereas the association between the general neuropsychiatric problems factor and auditory hallucinations persisted after controlling for autistic traits. Twin analyses revealed that the association between the general neuropsychiatric problems factor and auditory hallucinations was driven by shared genetic influences. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  20. The problem of general Radon representation for an arbitrary Hausdorff space

    Science.gov (United States)

    Zakharov, V. K.; Mikhalev, A. V.

    1999-10-01

    After the fundamental work of Riesz, Radon and Hausdorff in the period 1909-1914, the following problem of general Radon representation emerged: for any Hausdorff space find the space of linear functionals that are integrally representable by Radon measures. In the early 1950s, a partial solution of this problem (the bijective version) for locally compact spaces was obtained by Halmos, Hewitt, Edwards, Bourbaki and others. For bounded Radon measures on a Tychonoff space, the problem of isomorphic Radon representation was solved in 1956 by Prokhorov. In this paper we give a possible solution of the problem of general Radon representation. To do this, we use the family of metasemicontinuous functions with compact support and the class of thin functionals. We present bijective and isomorphic versions of the solution (Theorems 1 and 2 of §2.5). To get the isomorphic version, we introduce the family of Radon bimeasures.

  1. The problem of general Radon representation for an arbitrary Hausdorff space

    Energy Technology Data Exchange (ETDEWEB)

    Zakharov, V K [St Petersburg State University of Technology and Design (Russian Federation); Mikhalev, A V [M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    1999-10-31

    After the fundamental work of Riesz, Radon and Hausdorff in the period 1909-1914, the following problem of general Radon representation emerged: for any Hausdorff space find the space of linear functionals that are integrally representable by Radon measures. In the early 1950s, a partial solution of this problem (the bijective version) for locally compact spaces was obtained by Halmos, Hewitt, Edwards, Bourbaki and others. For bounded Radon measures on a Tychonoff space, the problem of isomorphic Radon representation was solved in 1956 by Prokhorov. In this paper we give a possible solution of the problem of general Radon representation. To do this, we use the family of metasemicontinuous functions with compact support and the class of thin functionals. We present bijective and isomorphic versions of the solution (Theorems 1 and 2 of paragraph 2.5). To get the isomorphic version, we introduce the family of Radon bimeasures.

  2. The problem of general Radon representation for an arbitrary Hausdorff space

    International Nuclear Information System (INIS)

    Zakharov, V K; Mikhalev, A V

    1999-01-01

    After the fundamental work of Riesz, Radon and Hausdorff in the period 1909-1914, the following problem of general Radon representation emerged: for any Hausdorff space find the space of linear functionals that are integrally representable by Radon measures. In the early 1950s, a partial solution of this problem (the bijective version) for locally compact spaces was obtained by Halmos, Hewitt, Edwards, Bourbaki and others. For bounded Radon measures on a Tychonoff space, the problem of isomorphic Radon representation was solved in 1956 by Prokhorov. In this paper we give a possible solution of the problem of general Radon representation. To do this, we use the family of metasemicontinuous functions with compact support and the class of thin functionals. We present bijective and isomorphic versions of the solution (Theorems 1 and 2 of paragraph 2.5). To get the isomorphic version, we introduce the family of Radon bimeasures

  3. Parallelization of mathematical library for generalized eigenvalue problem for real band matrices

    International Nuclear Information System (INIS)

    Tanaka, Yasuhisa.

    1997-05-01

    This research has focused on a parallelization of the mathematical library for a generalized eigenvalue problem for real band matrices on IBM SP and Hitachi SR2201. The origin of the library is LASO (Lanczos Algorithm with Selective Orthogonalization), which was developed on the basis of Block Lanczos method for standard eigenvalue problem for real band matrices at Texas University. We adopted D.O.F. (Degree Of Freedom) decomposition method for a parallelization of this library, and evaluated its parallel performance. (author)

  4. PROBLEMS OF CREATION THE MONITORING SYSTEM CONCERNING THE CONDITION OF INFORMATIZATION OF THE GENERAL EDUCATION INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    Valeriy Yu. Bykov

    2010-08-01

    Full Text Available In the article the problems, which appear under the creation of monitoring systems concerning the condition of informatization of general educational institutions, such as definition of monitoring object and list of parameters that will be traced during the monitoring, technologies of obtaining and actualization of data parameters, that are to be monitored, formats of data submission and ways of its processing, monitoring time period etc. are considered. In the article some decision of these problems are offered. Here is also mentioned the data of some characteristics and possibilities of the creation of monitoring systems concerning the condition of informatization of general educational institutions in Ukraine.

  5. Evolution of general surgical problems in patients with left ventricular assist devices.

    Science.gov (United States)

    McKellar, Stephen H; Morris, David S; Mauermann, William J; Park, Soon J; Zietlow, Scott P

    2012-11-01

    Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. These patients may develop acute noncardiac surgical problems around the time of LVAD implantation or, as survival continues to improve, chronic surgical problems as ambulatory patients remote from the LVAD implant. Previous reports of noncardiac surgical problems in LVAD patients included patients with older, first-generation devices and do not address newer, second-generation devices. We describe the frequency and management of noncardiac surgical problems encountered during LVAD support with these newer-generation devices to assist noncardiac surgeons involved in the care of patients with LVADs. We retrospectively reviewed the medical records of consecutive patients receiving LVADs at our institution. We collected data for any consultation by noncardiac surgeons within the scope of general surgery during LVAD support and subsequent treatment. Ninety-nine patients received implantable LVADs between 2003 and 2009 (first-generation, n = 19; second-generation, n = 80). Excluding intestinal hemorrhage, general surgical opinions were rendered for 34 patients with 49 problems, mostly in the acute recovery phase after LVAD implantation. Of those, 27 patients underwent 28 operations. Respiratory failure and intra-abdominal pathologies were the most common problems addressed, and LVAD rarely precluded operation. Patients with second-generation LVADs were more likely to survive hospitalization (P = .04) and develop chronic, rather than emergent, surgical problems. Patients with LVADs frequently require consultation from noncardiac surgeons within the scope of general surgeons and often require operation. Patients with second-generation LVADs are more likely to become outpatients and develop more elective surgical problems. Noncardiac surgeons will be increasingly involved in caring for patients with LVADs and should anticipate the problems unique to this patient

  6. Generalized Pattern Search methods for a class of nonsmooth optimization problems with structure

    Science.gov (United States)

    Bogani, C.; Gasparo, M. G.; Papini, A.

    2009-07-01

    We propose a Generalized Pattern Search (GPS) method to solve a class of nonsmooth minimization problems, where the set of nondifferentiability is included in the union of known hyperplanes and, therefore, is highly structured. Both unconstrained and linearly constrained problems are considered. At each iteration the set of poll directions is enforced to conform to the geometry of both the nondifferentiability set and the boundary of the feasible region, near the current iterate. This is the key issue to guarantee the convergence of certain subsequences of iterates to points which satisfy first-order optimality conditions. Numerical experiments on some classical problems validate the method.

  7. Green's functions and trace formulas for generalized Sturm-Liouville problems related by Darboux transformations

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel

    2010-01-01

    We study Green's functions of the generalized Sturm-Liouville problems that are related to each other by Darboux -equivalently, supersymmetrical - transformations. We establish an explicit relation between the corresponding Green's functions and derive a simple formula for their trace. The class of equations considered here includes the conventional Schroedinger equation and generalizations, such as for position-dependent mass and with linearly energy-dependent potential, as well as the stationary Fokker-Planck equation.

  8. Solving a class of generalized fractional programming problems using the feasibility of linear programs.

    Science.gov (United States)

    Shen, Peiping; Zhang, Tongli; Wang, Chunfeng

    2017-01-01

    This article presents a new approximation algorithm for globally solving a class of generalized fractional programming problems (P) whose objective functions are defined as an appropriate composition of ratios of affine functions. To solve this problem, the algorithm solves an equivalent optimization problem (Q) via an exploration of a suitably defined nonuniform grid. The main work of the algorithm involves checking the feasibility of linear programs associated with the interesting grid points. It is proved that the proposed algorithm is a fully polynomial time approximation scheme as the ratio terms are fixed in the objective function to problem (P), based on the computational complexity result. In contrast to existing results in literature, the algorithm does not require the assumptions on quasi-concavity or low-rank of the objective function to problem (P). Numerical results are given to illustrate the feasibility and effectiveness of the proposed algorithm.

  9. General versus executive cognitive ability in pupils with ADHD and with milder attention problems

    Directory of Open Access Journals (Sweden)

    Ek U

    2013-01-01

    Full Text Available Ulla Ek,1 Joakim Westerlund,2 Elisabeth Fernell31Department of Special Education, 2Department of Psychology, Stockholm University, Stockholm, 3Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg and the Research and Development Centre, Skaraborg Hospital Skövde, SwedenBackground: The aim of this study was to analyze two main types of cognitive domains in school children with different types and severities of attention-related problems. The cognitive domains examined were general cognitive ability and executive abilities.Methods: Three different clinical samples of pupils with school problems were analyzed to assess their cognitive Wechsler Intelligence Scale for Children profiles. In particular, the general cognitive ability index and the executive markers (ie, verbal memory index and processing speed index were of interest. Of the total sample (n = 198, two main groups were contrasted; one met the full criteria for attention deficit hyperactivity disorder (ADHD/subthreshold ADHD, and one was comprised of those with milder attention problems, insufficient to meet the criteria for ADHD/subthreshold ADHD.Results: It could be demonstrated that both groups had a significantly higher score on the general cognitive ability index than on measures of working memory and processing speed. This difference was more pronounced for boys.Conclusion: These types of cognitive differences need to be considered in children with different kinds of learning, behavior, and attention problems; this is also true for children presenting with an average general intelligence quotient and with milder attention problems. Current educational expectations are demanding for children with mild difficulties, and such cognitive information will add to the understanding of the child's learning problems, hopefully leading to a better adapted education than that conventionally available.Keywords: working memory, processing speed, children, learning and

  10. Do longer consultations improve the management of psychological problems in general practice? A systematic literature review

    Directory of Open Access Journals (Sweden)

    Hutton Catherine

    2007-05-01

    Full Text Available Abstract Background Psychological problems present a huge burden of illness in our community and GPs are the main providers of care. There is evidence that longer consultations in general practice are associated with improved quality of care; but this needs to be balanced against the fact that doctor time is a limited resource and longer consultations may lead to reduced access to health care. The aim of this research was to conduct a systematic literature review to determine whether management of psychological problems in general practice is associated with an increased consultation length and to explore whether longer consultations are associated with better health outcomes for patients with psychological problems. Methods A search was conducted on Medline (Ovid databases up to7 June 2006. The following search terms, were used: general practice or primary health care (free text or family practice (MeSH AND consultation length or duration (free text or time factors (MeSH AND depression or psychological problems or depressed (free text. A similar search was done in Web of Science, Pubmed, Google Scholar, and Cochrane Library and no other papers were found. Studies were included if they contained data comparing consultation length and management or detection of psychological problems in a general practice or primary health care setting. The studies were read and categories developed to enable systematic data extraction and synthesis. Results 29 papers met the inclusion criteria. Consultations with a recorded diagnosis of a psychological problem were reported to be longer than those with no recorded psychological diagnosis. It is not clear if this is related to the extra time or the consultation style. GPs reported that time pressure is a major barrier to treating depression. There was some evidence that increased consultation length is associated with more accurate diagnosis of psychological problems. Conclusion Further research is needed to

  11. Variational P1 approximations of general-geometry multigroup transport problems

    International Nuclear Information System (INIS)

    Rulko, R.P.; Tomasevic, D.; Larsen, E.W.

    1995-01-01

    A variational approximation is developed for general-geometry multigroup transport problems with arbitrary anisotropic scattering. The variational principle is based on a functional that approximates a reaction rate in a subdomain of the system. In principle, approximations that result from this functional ''optimally'' determine such reaction rates. The functional contains an arbitrary parameter α and requires the approximate solutions of a forward and an adjoint transport problem. If the basis functions for the forward and adjoint solutions are chosen to be linear functions of the angular variable Ω, the functional yields the familiar multigroup P 1 equations for all values of α. However, the boundary conditions that result from the functional depend on α. In particular, for problems with vacuum boundaries, one obtains the conventional mixed boundary condition, but with an extrapolation distance that depends continuously on α. The choice α = 0 yields a generalization of boundary conditions derived earlier by Federighi and Pomraning for a more limited class of problems. The choice α = 1 yields a generalization of boundary conditions derived previously by Davis for monoenergetic problems. Other boundary conditions are obtained by choosing different values of α. The authors discuss this indeterminancy of α in conjunction with numerical experiments

  12. A general solution of the plane problem in thermoelasticity in polar coordinates

    International Nuclear Information System (INIS)

    Tabakman, H.D.; Lin, Y.J.

    1977-01-01

    A general solution, in polar coordinates, of the plane problem in thermoelasticity is obtained in terms of a stress and displacement function. The solution is valid for arbitrary temperature distribution T(r,theta). The characteristic feature of the paper is the forthright determination of the displacement components brought about by the introduction of a displacement function. (Auth.)

  13. A general solution of the plane problem thermoelasticity in polar coordinates

    International Nuclear Information System (INIS)

    Tabakman, H.D.; Lin, Y.J.

    1977-01-01

    A general solution, in polar coordinates, of the plane problem in thermoelasticity is obtained in terms of a stress and displacement function. The solution is valid for arbitrary temperature distribution T(r, theta). The characteristic feature of the paper is the forthright determination of the displacement components brought about by the introduction of a displacement function

  14. Formulations and Branch-and-Cut Algorithms for the Generalized Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Bektas, Tolga; Erdogan, Günes; Røpke, Stefan

    2011-01-01

    The Generalized Vehicle Routing Problem (GVRP) consists of nding a set of routes for a number of vehicles with limited capacities on a graph with the vertices partitioned into clusters with given demands such that the total cost of travel is minimized and all demands are met. This paper offers four...

  15. A Note on the Dual of an Unconstrained (Generalized) Geometric Programming Problem

    NARCIS (Netherlands)

    J.B.G. Frenk (Hans); G.J. Still

    2005-01-01

    textabstractIn this note we show that the strong duality theorem of an unconstrained (generalized) geometric programming problem as defined by Peterson (cf.[1]) is actually a special case of a Lagrangian duality result. Contrary to [1] we also consider the case that the set C is compact and

  16. General stochastic variational formulation for the oligopolistic market equilibrium problem with excesses

    Science.gov (United States)

    Barbagallo, Annamaria; Di Meglio, Guglielmo; Mauro, Paolo

    2017-07-01

    The aim of the paper is to study, in a Hilbert space setting, a general random oligopolistic market equilibrium problem in presence of both production and demand excesses and to characterize the random Cournot-Nash equilibrium principle by means of a stochastic variational inequality. Some existence results are presented.

  17. Association between Speech-Language, General Cognitive Functioning and Behaviour Problems in Individuals with Williams Syndrome

    Science.gov (United States)

    Rossi, N. F.; Giacheti, C. M.

    2017-01-01

    Background: Williams syndrome (WS) phenotype is described as unique and intriguing. The aim of this study was to investigate the associations between speech-language abilities, general cognitive functioning and behavioural problems in individuals with WS, considering age effects and speech-language characteristics of WS sub-groups. Methods: The…

  18. Generalization of the Fourier Convergence Analysis in the Neutron Diffusion Eigenvalue Problem

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Noh, Jae Man; Joo, Hyung Kook

    2005-01-01

    Fourier error analysis has been a standard technique for the stability and convergence analysis of linear and nonlinear iterative methods. Lee et al proposed new 2- D/1-D coupling methods and demonstrated several advantages of the new methods by performing a Fourier convergence analysis of the methods as well as two existing methods for a fixed source problem. We demonstrated the Fourier convergence analysis of one of the 2-D/1-D coupling methods applied to a neutron diffusion eigenvalue problem. However, the technique cannot be used directly to analyze the convergence of the other 2-D/1-D coupling methods since some algorithm-specific features were used in our previous study. In this paper we generalized the Fourier convergence analysis technique proposed and analyzed the convergence of the 2-D/1-D coupling methods applied to a neutron diffusion Eigenvalue problem using the generalized technique

  19. A theory of general solutions of 3D problems in 1D hexagonal quasicrystals

    International Nuclear Information System (INIS)

    Gao Yang; Xu Sipeng; Zhao Baosheng

    2008-01-01

    A theory of general solutions of three-dimensional (3D) problems is developed for the coupled equilibrium equations in 1D hexagonal quasicrystals (QCs), and two new general solutions, which are called generalized Lekhnitskii-Hu-Nowacki (LHN) and Elliott-Lodge (E-L) solutions, respectively, are presented based on three theorems. As a special case, the generalized LHN solution is obtained from our previous general solution by introducing three high-order displacement functions. For further simplification, considering three cases in which three characteristic roots are distinct or possibly equal to each other, the generalized E-L solution shall take different forms, and be expressed in terms of four quasi-harmonic functions which are very simple and useful. It is proved that the general solution presented by Peng and Fan is consistent with one case of the generalized E-L solution, while does not include the other two cases. It is important to note that generalized LHN and E-L solutions are complete in z-convex domains, while incomplete in the usual non-z-convex domains

  20. A Fuzzy Approach Using Generalized Dinkelbach’s Algorithm for Multiobjective Linear Fractional Transportation Problem

    Directory of Open Access Journals (Sweden)

    Nurdan Cetin

    2014-01-01

    Full Text Available We consider a multiobjective linear fractional transportation problem (MLFTP with several fractional criteria, such as, the maximization of the transport profitability like profit/cost or profit/time, and its two properties are source and destination. Our aim is to introduce MLFTP which has not been studied in literature before and to provide a fuzzy approach which obtain a compromise Pareto-optimal solution for this problem. To do this, first, we present a theorem which shows that MLFTP is always solvable. And then, reducing MLFTP to the Zimmermann’s “min” operator model which is the max-min problem, we construct Generalized Dinkelbach’s Algorithm for solving the obtained problem. Furthermore, we provide an illustrative numerical example to explain this fuzzy approach.

  1. Systems of general nonlinear set-valued mixed variational inequalities problems in Hilbert spaces

    Directory of Open Access Journals (Sweden)

    Cho Yeol

    2011-01-01

    Full Text Available Abstract In this paper, the existing theorems and methods for finding solutions of systems of general nonlinear set-valued mixed variational inequalities problems in Hilbert spaces are studied. To overcome the difficulties, due to the presence of a proper convex lower semi-continuous function, φ and a mapping g, which appeared in the considered problem, we have used some applications of the resolvent operator technique. We would like to point out that although many authors have proved results for finding solutions of the systems of nonlinear set-valued (mixed variational inequalities problems, it is clear that it cannot be directly applied to the problems that we have considered in this paper because of φ and g. 2000 AMS Subject Classification: 47H05; 47H09; 47J25; 65J15.

  2. Women with urinary incontinence: self-perceived worries and general practitioners' knowledge of problem.

    Science.gov (United States)

    Lagro-Janssen, T L; Smits, A J; Van Weel, C

    1990-01-01

    In the context of a large scale survey of health problems in women aged 50 to 65 years, a study was undertaken on the effects of incontinence on daily life. For this purpose 1442 women randomly selected from the practice files of 75 general practitioners in the eastern part of the Netherlands were interviewed at home (response rate 60%). In cases of moderate or severe incontinence the general practitioner of the woman concerned was asked whether this problem had been diagnosed in general practice. Incontinence was reported in 22.5% of the women. Overall, 77.8% of the women did not feel worried about it and 75.4% did not feel restricted in their activities; even for women with severe incontinence (daily frequency and needing protective pads) only 15.6% experienced much worry and 15.7% much restriction. About a third of the women with incontinence (32.0%) had been identified by their general practitioner. The greater the worries and restrictions owing to incontinence, the greater the chance that the incontinence was known to the general practitioner concerned. Only a small minority of the women who felt severely restricted were not identified by their general practitioner. There was a positive relation between recognized incontinence and a history of hysterectomy. This study contradicts the image of the incontinent woman as isolated and helpless; most women in this study seemed able to cope. PMID:2121179

  3. Frequent attenders in general practice: problem solving treatment provided by nurses [ISRCTN51021015

    Directory of Open Access Journals (Sweden)

    van Oppen P

    2005-10-01

    Full Text Available Abstract Background There is a need for assistance from primary care mental health workers in general practice in the Netherlands. General practitioners (GPs experience an overload of frequent attenders suffering from psychological problems. Problem Solving Treatment (PST is a brief psychological treatment tailored for use in a primary care setting. PST is provided by nurses, and earlier research has shown that it is a treatment at least as effective as usual care. However, research outcomes are not totally satisfying. This protocol describes a randomized clinical trial on the effectiveness of PST provided by nurses for patients in general practice. The results of this study, which currently being carried out, will be presented as soon as they are available. Methods/design This study protocol describes the design of a randomized controlled trial to investigate the effectiveness and cost-effectiveness of PST and usual care compared to usual care only. Patients, 18 years and older, who present psychological problems and are frequent attenders in general practice are recruited by the research assistant. The participants receive questionnaires at baseline, after the intervention, and again after 3 months and 9 months. Primary outcome is the reduction of symptoms, and other outcomes measured are improvement in problem solving skills, psychological and physical well being, daily functioning, social support, coping styles, problem evaluation and health care utilization. Discussion Our results may either confirm that PST in primary care is an effective way of dealing with emotional disorders and a promising addition to the primary care in the UK and USA, or may question this assumption. This trial will allow an evaluation of the effects of PST in practical circumstances and in a rather heterogeneous group of primary care patients. This study delivers scientific support for this use and therefore indications for optimal treatment and referral.

  4. Generalized multiscale finite element methods for problems in perforated heterogeneous domains

    KAUST Repository

    Chung, Eric T.

    2015-06-08

    Complex processes in perforated domains occur in many real-world applications. These problems are typically characterized by physical processes in domains with multiple scales. Moreover, these problems are intrinsically multiscale and their discretizations can yield very large linear or nonlinear systems. In this paper, we investigate multiscale approaches that attempt to solve such problems on a coarse grid by constructing multiscale basis functions in each coarse grid, where the coarse grid can contain many perforations. In particular, we are interested in cases when there is no scale separation and the perforations can have different sizes. In this regard, we mention some earlier pioneering works, where the authors develop multiscale finite element methods. In our paper, we follow Generalized Multiscale Finite Element Method (GMsFEM) and develop a multiscale procedure where we identify multiscale basis functions in each coarse block using snapshot space and local spectral problems. We show that with a few basis functions in each coarse block, one can approximate the solution, where each coarse block can contain many small inclusions. We apply our general concept to (1) Laplace equation in perforated domains; (2) elasticity equation in perforated domains; and (3) Stokes equations in perforated domains. Numerical results are presented for these problems using two types of heterogeneous perforated domains. The analysis of the proposed methods will be presented elsewhere. © 2015 Taylor & Francis

  5. Variational methods for problems from plasticity theory and for generalized Newtonian fluids

    CERN Document Server

    Fuchs, Martin

    2000-01-01

    Variational methods are applied to prove the existence of weak solutions for boundary value problems from the deformation theory of plasticity as well as for the slow, steady state flow of generalized Newtonian fluids including the Bingham and Prandtl-Eyring model. For perfect plasticity the role of the stress tensor is emphasized by studying the dual variational problem in appropriate function spaces. The main results describe the analytic properties of weak solutions, e.g. differentiability of velocity fields and continuity of stresses. The monograph addresses researchers and graduate students interested in applications of variational and PDE methods in the mechanics of solids and fluids.

  6. General practice-based clinical trials in Germany - a problem analysis

    Directory of Open Access Journals (Sweden)

    Hummers-Pradier Eva

    2012-11-01

    Full Text Available Abstract Background In Germany, clinical trials and comparative effectiveness studies in primary care are still very rare, while their usefulness has been recognised in many other countries. A network of researchers from German academic general practice has explored the reasons for this discrepancy. Methods Based on a comprehensive literature review and expert group discussions, problem analyses as well as structural and procedural prerequisites for a better implementation of clinical trials in German primary care are presented. Results In Germany, basic biomedical science and technology is more reputed than clinical or health services research. Clinical trials are funded by industry or a single national programme, which is highly competitive, specialist-dominated, exclusive of pilot studies, and usually favours innovation rather than comparative effectiveness studies. Academic general practice is still not fully implemented, and existing departments are small. Most general practitioners (GPs work in a market-based, competitive setting of small private practices, with a high case load. They have no protected time or funding for research, and mostly no research training or experience. Good Clinical Practice (GCP training is compulsory for participation in clinical trials. The group defined three work packages to be addressed regarding clinical trials in German general practice: (1 problem analysis, and definition of (2 structural prerequisites and (3 procedural prerequisites. Structural prerequisites comprise specific support facilities for general practice-based research networks that could provide practices with a point of contact. Procedural prerequisites consist, for example, of a summary of specific relevant key measures, for example on a web platform. The platform should contain standard operating procedures (SOPs, templates, checklists and other supporting materials for researchers. Conclusion All in all, our problem analyses revealed that

  7. Generalization of the geometric optical series approach for nonadiabatic scattering problems

    International Nuclear Information System (INIS)

    Herman, M.F.

    1982-01-01

    The geometric optical series approach of Bremmer is generalized for multisurface nonadiabatic scattering problems. This method yields the formal solution of the Schroedinger equation as an infinite series of multiple integrals. The zeroth order term corresponds to WKB propagation on a single adiabatic surface, while the general Nth order term involves N reflections and/or transitions between surfaces accompanied by ''free,'' single surface semiclassical propagation between the points of reflection and transition. Each term is integrated over all possible transition and reflection points. The adiabatic and diabatic limits of this expression are discussed. Numerical results, in which all reflections are ignored, are presented for curve crossing and noncrossing problems. These results are compared to exact quantum results and are shown to be highly accurate

  8. Inverse planning for x-ray rotation therapy: a general solution of the inverse problem

    International Nuclear Information System (INIS)

    Oelfke, U.; Bortfeld, T.

    1999-01-01

    Rotation therapy with photons is currently under investigation for the delivery of intensity modulated radiotherapy (IMRT). An analytical approach for inverse treatment planning of this radiotherapy technique is described. The inverse problem for the delivery of arbitrary 2D dose profiles is first formulated and then solved analytically. In contrast to previously applied strategies for solving the inverse problem, it is shown that the most general solution for the fluence profiles consists of two independent solutions of different parity. A first analytical expression for both fluence profiles is derived. The mathematical derivation includes two different strategies, an elementary expansion of fluence and dose into polynomials and a more practical approach in terms of Fourier transforms. The obtained results are discussed in the context of previous work on this problem. (author)

  9. Reply to C. M. Will on the axially symmetric two-body problem in general relativity

    International Nuclear Information System (INIS)

    Cooperstock, F.I.; Lim, P.H.

    1985-01-01

    The recent paper by Will (1983) is considered which purports to demonstrate that the gravitational radiation which the authors had computed from their model two-body free-fall system is consistent with the so-called quadrupole formula. It is shown that in fact the system presented by Will is different from the authors and that the illegitimate application of the quadrupole formula to the authors system leads to a smaller flux than that which is correctly deduced using general relativity and a proper consideration of nonlinearities. It is demonstrated that a judicious choice of stress release is propagated through the bodies as a superposition of plane and spherical waves leading to pressure fluctuations to the order in question. This underlines the essential distinction between the authors problem and the Will problem. Various aspects of the problem are also discussed. 25 references

  10. An analogue of Morse theory for planar linear networks and the generalized Steiner problem

    International Nuclear Information System (INIS)

    Karpunin, G A

    2000-01-01

    A study is made of the generalized Steiner problem: the problem of finding all the locally minimal networks spanning a given boundary set (terminal set). It is proposed to solve this problem by using an analogue of Morse theory developed here for planar linear networks. The space K of all planar linear networks spanning a given boundary set is constructed. The concept of a critical point and its index is defined for the length function l of a planar linear network. It is shown that locally minimal networks are local minima of l on K and are critical points of index 1. The theorem is proved that the sum of the indices of all the critical points is equal to χ(K)=1. This theorem is used to find estimates for the number of locally minimal networks spanning a given boundary set

  11. Overlapping domain decomposition preconditioners for the generalized Davidson method for the eigenvalue problem

    Energy Technology Data Exchange (ETDEWEB)

    Stathopoulos, A.; Fischer, C.F. [Vanderbilt Univ., Nashville, TN (United States); Saad, Y.

    1994-12-31

    The solution of the large, sparse, symmetric eigenvalue problem, Ax = {lambda}x, is central to many scientific applications. Among many iterative methods that attempt to solve this problem, the Lanczos and the Generalized Davidson (GD) are the most widely used methods. The Lanczos method builds an orthogonal basis for the Krylov subspace, from which the required eigenvectors are approximated through a Rayleigh-Ritz procedure. Each Lanczos iteration is economical to compute but the number of iterations may grow significantly for difficult problems. The GD method can be considered a preconditioned version of Lanczos. In each step the Rayleigh-Ritz procedure is solved and explicit orthogonalization of the preconditioned residual ((M {minus} {lambda}I){sup {minus}1}(A {minus} {lambda}I)x) is performed. Therefore, the GD method attempts to improve convergence and robustness at the expense of a more complicated step.

  12. A complete basis for a perturbation expansion of the general N-body problem

    International Nuclear Information System (INIS)

    Laing, W Blake; Kelle, David W; Dunn, Martin; Watson, Deborah K

    2009-01-01

    We discuss a basis set developed to calculate perturbation coefficients in an expansion of the general N-body problem. This basis has two advantages. First, the basis is complete order-by-order for the perturbation series. Second, the number of independent basis tensors spanning the space for a given order does not scale with N, the number of particles, despite the generality of the problem. At first order, the number of basis tensors is 25 for all N, i.e. the problem scales as N 0 , although one would initially expect an N 6 scaling at first order. The perturbation series is expanded in inverse powers of the spatial dimension. This results in a maximally symmetric configuration at lowest order which has a point group isomorphic with the symmetric group, S N . The resulting perturbation series is order-by-order invariant under the N! operations of the S N point group which is responsible for the slower than exponential growth of the basis. In this paper, we demonstrate the completeness of the basis and perform the first test of this formalism through first order by comparing to an exactly solvable fully interacting problem of N particles with a two-body harmonic interaction potential

  13. Solving the generalized symmetric eigenvalue problem using tile algorithms on multicore architectures

    KAUST Repository

    Ltaief, Hatem

    2012-01-01

    This paper proposes an efficient implementation of the generalized symmetric eigenvalue problem on multicore architecture. Based on a four-stage approach and tile algorithms, the original problem is first transformed into a standard symmetric eigenvalue problem by computing the Cholesky factorization of the right hand side symmetric definite positive matrix (first stage), and applying the inverse of the freshly computed triangular Cholesky factors to the original dense symmetric matrix of the problem (second stage). Calculating the eigenpairs of the resulting problem is then equivalent to the eigenpairs of the original problem. The computation proceeds by reducing the updated dense symmetric matrix to symmetric band form (third stage). The band structure is further reduced by applying a bulge chasing procedure, which annihilates the extra off-diagonal entries using orthogonal transformations (fourth stage). More details on the third and fourth stage can be found in Haidar et al. [Accepted at SC\\'11, November 2011]. The eigenvalues are then calculated from the tridiagonal form using the standard LAPACK QR algorithm (i.e., DTSEQR routine), while the complex and challenging eigenvector computations will be addressed in a companion paper. The tasks from the various stages can concurrently run in an out-of-order fashion. The data dependencies are cautiously tracked by the dynamic runtime system environment QUARK, which ensures the dependencies are not violated for numerical correctness purposes. The obtained tile four-stage generalized symmetric eigenvalue solver significantly outperforms the state-of-the-art numerical libraries (up to 21-fold speed up against multithreaded LAPACK with optimized multithreaded MKL BLAS and up to 4-fold speed up against the corresponding routine from the commercial numerical software Intel MKL) on four sockets twelve cores AMD system with a 24000×24000 matrix size. © 2012 The authors and IOS Press. All rights reserved.

  14. Approximation in generalized Hardy classes and resolution of inverse problems for tokamaks

    International Nuclear Information System (INIS)

    Fisher, Y.

    2011-11-01

    This thesis concerns both the theoretical and constructive resolution of inverse problems for isotropic diffusion equation in planar domains, simply and doubly connected. From partial Cauchy boundary data (potential, flux), we look for those quantities on the remaining part of the boundary, where no information is available, as well as inside the domain. The proposed approach proceeds by considering solutions to the diffusion equation as real parts of complex valued solutions to some conjugated Beltrami equation. These particular generalized analytic functions allow to introduce Hardy classes, where the inverse problem is stated as a best constrained approximation issue (bounded extrema problem), and thereby is regularized. Hence, existence and smoothness properties, together with density results of traces on the boundary, ensure well-posedness. An application is studied, to a free boundary problem for a magnetically confined plasma in the tokamak Tore Supra (CEA Cadarache France). The resolution of the approximation problem on a suitable basis of functions (toroidal harmonics) leads to a qualification criterion for the estimated plasma boundary. A descent algorithm makes it decrease, and refines the estimations. The method does not require any integration of the solution in the overall domain. It furnishes very accurate numerical results, and could be extended to other devices, like JET or ITER. (author)

  15. Still a difficult business? Negotiating alcohol-related problems in general practice consultations.

    Science.gov (United States)

    Rapley, Tim; May, Carl; Frances Kaner, Eileen

    2006-11-01

    This paper describes general practitioners' (GPs) experiences of detecting and managing alcohol and alcohol-related problems in consultations. We undertook qualitative research in two phases in the North-East of England. Initially, qualitative interviews with 29 GPs explored their everyday work with patients with alcohol-related issues. We then undertook group interviews--two with GPs and one with a primary care team--where they discussed and challenged findings of the interviews. The GPs reported routinely discussing alcohol with patients with a range of alcohol-related problems. GPs believed that this work is important, but felt that until patients were willing to accept that their alcohol consumption was problematic they could achieve very little. They tentatively introduced alcohol as a potential problem, re-introduced the topic periodically, and then waited until the patient decided to change their behaviour. They were aware that they could identify and manage more patients. A lack of time and having to work with the multiple problems that patients brought to consultations were the main factors that stopped GPs managing more risky drinkers. Centrally, we compared the results of our study with [Thom, B., & Tellez, C. (1986). A difficult business-Detecting and managing alcohol-problems in general-practice. British Journal of Addiction, 81, 405-418] seminal study that was undertaken 20 years ago. We show how the intellectual, moral, emotional and practical difficulties that GPs currently face are quite similar to those faced by GPs from 20 years ago. As the definition of what could constitute abnormal alcohol consumption has expanded, so the range of consultations that they may have to negotiate these difficulties in has also expanded.

  16. Perceptions of general environmental problems, willingness to expend federal funds on these problems, and concerns regarding the Los Alamos national laboratory: Hispanics are more concerned than Whites

    International Nuclear Information System (INIS)

    Burger, Joanna; Myers, O.; Boring, C.S.; Dixon, C.; Lord, C.; Ramos, R.; Shukla, S.; Gochfeld, Michael

    2004-01-01

    Perceptions about general environmental problems, governmental spending for these problems, and major concerns about the US Department of Energy's Los Alamos National Laboratory (LANL) were examined by interviewing 356 people attending a gun show in Albuquerque, New Mexico. The hypothesis that there are differences in these three areas as a function of ethnicity was examined. We predicted that if differences existed, they would exist for all three evaluations (general environmental problems, government spending, and environmental concerns about LANL). However, this was not the case; there were fewer ethnic differences concerning LANL. Hispanics rated most general environmental problems higher than Whites and rated their willingness to expend federal funds higher than Whites, although all groups gave a lower score on willingness than on concern. Further, the congruence between these two types of ratings was higher for Hispanics than for others. In general, the concerns expressed by subjects about LANL showed few ethnic differences, and everyone was most concerned about contamination. These data indicate that Hispanics attending a gun show are equally or more concerned than others about environmental problems generally but are not more concerned about LANL. The data can be useful for developing future research and stewardship plans and for understanding general environmental problems and their relationship to concerns about LANL. More generally, they indicate that the attitudes and perceptions of Hispanics deserve increased study in a general population

  17. Educational Level, Underachievement, and General Mental Health Problems in 10,866 Adolescents.

    Science.gov (United States)

    Tempelaar, Wanda M; de Vos, Nelleke; Plevier, Carolien M; van Gastel, Willemijn A; Termorshuizen, Fabian; MacCabe, James H; Boks, Marco P M

    2017-08-01

    Previous research suggests that cognitive functioning is associated with the risk of several adult psychiatric disorders. In this study we investigated whether adolescents who perform worse than expected at secondary school are at a higher risk for general mental health problems. In a cross-sectional survey comprising 10,866 Dutch adolescents aged 13 to 16 years, underachievement at secondary school was defined as the discrepancy between predicted school grade and actual grade 1 or 3 years later. Mental health problems were assessed using the Strengths and Difficulties Questionnaire. We investigated the association of underachievement with mental health problems using logistic regression, adjusting for potential confounders. Underachievement was associated with general psychopathology in pupils aged 13 to 14 years (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.47-2.37) and in pupils aged 15 to 16 years (OR, 2.05; 95% CI, 1.67-2.52) in a multivariate analysis including sociodemographic factors. The association between underachievement and mental health problems was attenuated when school factors such as teacher advice and interaction between underachievement and teacher advice were added, but underachievement remained significantly associated with mental health problems in adolescents in the higher educational tracks (pupils aged 13-14 years: OR, 2.22; 95% CI, 1.07-4.60 and OR, 2.41; 95% CI, 1.10-5.30, age 15-16 years: OR, 2.63; 95% CI, 1.38-5.03). In the multivariate analysis including the interaction between underachievement and teacher advice, a significant interaction effect occurs between underachievement and teacher advice in the higher tracks. Values of OR and CI are given for each significant interaction term. In the younger age group (pupils aged 13-14 years) this results in 2 sets of OR and CI. This association was most pronounced for the hyperactivity subscale of the Strengths and Difficulties Questionnaire. Underachievement at secondary school

  18. Singular perturbations of manifolds, with applications to the problem of motion in general relativity

    International Nuclear Information System (INIS)

    Kates, R.E.

    1979-01-01

    This thesis shows that a small body with possibly strong internal gravity moves through an empty region of a curved, and not necessarily asymptotically flat, external spacetime on an approximate geodesic. By approximate geodesic, the following is meant: Suppose the ratio epsilon = m/L 1 - where m is the body's mass and L is a curvature reference length of the external field - is a small parameter. Then the body's worldline deviates from a geodesic only by distances of at most THETA(epsilon) L over times of order L. The worldline is calculated directly from the Einstein field equation using a singular perturbation technique that has been generalized from the method of matched asymptotic expansions. The need for singular perturbation techniques has long been appreciated in fluid mechanics, where they are now standard procedure in problems in which the straightforward expansion in powers of a small parameter fails to give a correct qualitative picture. In part I of this thesis, singular perturbations on manifolds are formulated in a coordinate-free way suitable for treating problems in general relativity and other field theories. Most importantly for this thesis, the coordinate-free formulation of singular perturbations given in part I is essential for treatment of the problem of motion in part II

  19. A Generalized Ant Colony Algorithm for Job一shop Scheduling Problem

    Directory of Open Access Journals (Sweden)

    ZHANG Hong-Guo

    2017-02-01

    Full Text Available Aiming at the problem of ant colony algorithm for solving Job一shop scheduling problem. Considering the complexity of the algorithm that uses disjunctive graph to describe the relationship between workpiece processing. To solve the problem of optimal solution,a generalized ant colony algorithm is proposed. Under the premise of considering constrained relationship between equipment and process,the pheromone update mechanism is applied to solve Job-shop scheduling problem,so as to improve the quality of the solution. In order to improve the search efficiency,according to the state transition rules of ant colony algorithm,this paper makes a detailed study on the selection and improvement of the parameters in the algorithm,and designs the pheromone update strategy. Experimental results show that a generalized ant colony algorithm is more feasible and more effective. Compared with other algorithms in the literature,the results prove that the algorithm improves in computing the optimal solution and convergence speed.

  20. Efficient generalized Golub-Kahan based methods for dynamic inverse problems

    Science.gov (United States)

    Chung, Julianne; Saibaba, Arvind K.; Brown, Matthew; Westman, Erik

    2018-02-01

    We consider efficient methods for computing solutions to and estimating uncertainties in dynamic inverse problems, where the parameters of interest may change during the measurement procedure. Compared to static inverse problems, incorporating prior information in both space and time in a Bayesian framework can become computationally intensive, in part, due to the large number of unknown parameters. In these problems, explicit computation of the square root and/or inverse of the prior covariance matrix is not possible, so we consider efficient, iterative, matrix-free methods based on the generalized Golub-Kahan bidiagonalization that allow automatic regularization parameter and variance estimation. We demonstrate that these methods for dynamic inversion can be more flexible than standard methods and develop efficient implementations that can exploit structure in the prior, as well as possible structure in the forward model. Numerical examples from photoacoustic tomography, space-time deblurring, and passive seismic tomography demonstrate the range of applicability and effectiveness of the described approaches. Specifically, in passive seismic tomography, we demonstrate our approach on both synthetic and real data. To demonstrate the scalability of our algorithm, we solve a dynamic inverse problem with approximately 43 000 measurements and 7.8 million unknowns in under 40 s on a standard desktop.

  1. A general approach to regularizing inverse problems with regional data using Slepian wavelets

    Science.gov (United States)

    Michel, Volker; Simons, Frederik J.

    2017-12-01

    Slepian functions are orthogonal function systems that live on subdomains (for example, geographical regions on the Earth’s surface, or bandlimited portions of the entire spectrum). They have been firmly established as a useful tool for the synthesis and analysis of localized (concentrated or confined) signals, and for the modeling and inversion of noise-contaminated data that are only regionally available or only of regional interest. In this paper, we consider a general abstract setup for inverse problems represented by a linear and compact operator between Hilbert spaces with a known singular-value decomposition (svd). In practice, such an svd is often only given for the case of a global expansion of the data (e.g. on the whole sphere) but not for regional data distributions. We show that, in either case, Slepian functions (associated to an arbitrarily prescribed region and the given compact operator) can be determined and applied to construct a regularization for the ill-posed regional inverse problem. Moreover, we describe an algorithm for constructing the Slepian basis via an algebraic eigenvalue problem. The obtained Slepian functions can be used to derive an svd for the combination of the regionalizing projection and the compact operator. As a result, standard regularization techniques relying on a known svd become applicable also to those inverse problems where the data are regionally given only. In particular, wavelet-based multiscale techniques can be used. An example for the latter case is elaborated theoretically and tested on two synthetic numerical examples.

  2. Averaging problem in general relativity, macroscopic gravity and using Einstein's equations in cosmology.

    Science.gov (United States)

    Zalaletdinov, R. M.

    1998-04-01

    The averaging problem in general relativity is briefly discussed. A new setting of the problem as that of macroscopic description of gravitation is proposed. A covariant space-time averaging procedure is described. The structure of the geometry of macroscopic space-time, which follows from averaging Cartan's structure equations, is described and the correlation tensors present in the theory are discussed. The macroscopic field equations (averaged Einstein's equations) derived in the framework of the approach are presented and their structure is analysed. The correspondence principle for macroscopic gravity is formulated and a definition of the stress-energy tensor for the macroscopic gravitational field is proposed. It is shown that the physical meaning of using Einstein's equations with a hydrodynamic stress-energy tensor in looking for cosmological models means neglecting all gravitational field correlations. The system of macroscopic gravity equations to be solved when the correlations are taken into consideration is given and described.

  3. Multigrid method applied to the solution of an elliptic, generalized eigenvalue problem

    Energy Technology Data Exchange (ETDEWEB)

    Alchalabi, R.M. [BOC Group, Murray Hill, NJ (United States); Turinsky, P.J. [North Carolina State Univ., Raleigh, NC (United States)

    1996-12-31

    The work presented in this paper is concerned with the development of an efficient MG algorithm for the solution of an elliptic, generalized eigenvalue problem. The application is specifically applied to the multigroup neutron diffusion equation which is discretized by utilizing the Nodal Expansion Method (NEM). The underlying relaxation method is the Power Method, also known as the (Outer-Inner Method). The inner iterations are completed using Multi-color Line SOR, and the outer iterations are accelerated using Chebyshev Semi-iterative Method. Furthermore, the MG algorithm utilizes the consistent homogenization concept to construct the restriction operator, and a form function as a prolongation operator. The MG algorithm was integrated into the reactor neutronic analysis code NESTLE, and numerical results were obtained from solving production type benchmark problems.

  4. ALAM/CLAM and some applications of computer algebra systems to problems in general relativity

    International Nuclear Information System (INIS)

    Russell-Clark, R.A.

    1973-01-01

    This paper is divided into three parts. Part A presents a historical survey of the development of the system, a brief description of its features and, finally, a critical assessment. ALAM and CLAM have been used in many problems in General Relativity; the vast majority of these belong to a set of standard calculations termed ''metric applications''. However, four large non-standard applications have been attempted successfully and these are described in Part B. CAMAL is the only other system which has been used extensively for work in relativity. CAMAL has played an important role in two research projects and details of these are given in Part C

  5. Comparison of three-dimensional ocean general circulation models on a benchmark problem

    International Nuclear Information System (INIS)

    Chartier, M.

    1990-12-01

    A french and an american Ocean General Circulation Models for deep-sea disposal of radioactive wastes are compared on a benchmark test problem. Both models are three-dimensional. They solve the hydrostatic primitive equations of the ocean with two different finite difference techniques. Results show that the dynamics simulated by both models are consistent. Several methods for the running of a model from a known state are tested in the French model: the diagnostic method, the prognostic method, the acceleration of convergence and the robust-diagnostic method

  6. The generalized Laguerre polynomials, the associated Bessel functions and application to propagation problems

    International Nuclear Information System (INIS)

    Dattoli, G.; Torre, A.; Mancho, A.M.

    2000-01-01

    The theory of generalized Bessel functions has found significant applications in the analysis of radiation phenomena, associated with charges moving in magnetic devices. In this paper we exploit the monomiality principle to discuss the theory of two-variable Laguerre polynomials and introduce the associated Laguerre-Bessel functions. We study their properties (addition and multiplication theorems, generating function, recurrence relations and so on) and discuss the link with the ordinary case. The usefulness of the obtained results to treat problems relevant to the paraxial propagation of electromagnetic waves is also discussed.

  7. Random matrix analysis of the QCD sign problem for general topology

    International Nuclear Information System (INIS)

    Bloch, Jacques; Wettig, Tilo

    2009-01-01

    Motivated by the important role played by the phase of the fermion determinant in the investigation of the sign problem in lattice QCD at nonzero baryon density, we derive an analytical formula for the average phase factor of the fermion determinant for general topology in the microscopic limit of chiral random matrix theory at nonzero chemical potential, for both the quenched and the unquenched case. The formula is a nontrivial extension of the expression for zero topology derived earlier by Splittorff and Verbaarschot. Our analytical predictions are verified by detailed numerical random matrix simulations of the quenched theory.

  8. Conformal changes of metrics and the initial-value problem of general relativity

    International Nuclear Information System (INIS)

    Mielke, E.W.

    1977-01-01

    Conformal techniques are reviewed with respect to applications to the initial-value problem of general relativity. Invariant transverse traceless decompositions of tensors, one of its main tools, are related to representations of the group of 'conformeomorphisms' acting on the space of all Riemannian metrics on M. Conformal vector fields, a kernel in the decomposition, are analyzed on compact manifolds with constant scalar curvature. The realization of arbitrary functions as scalar curvature of conformally equivalent metrics, a generalization of Yamabe's (Osaka Math. J.; 12:12 (1960)) conjecture, is applied to the Hamiltonian constraint and to the issue of positive energy of gravitational fields. Various approaches to the solution of the initial-value equations produced by altering the scaling behaviour of the second fundamental form are compared. (author)

  9. Multi-choice stochastic transportation problem involving general form of distributions.

    Science.gov (United States)

    Quddoos, Abdul; Ull Hasan, Md Gulzar; Khalid, Mohammad Masood

    2014-01-01

    Many authors have presented studies of multi-choice stochastic transportation problem (MCSTP) where availability and demand parameters follow a particular probability distribution (such as exponential, weibull, cauchy or extreme value). In this paper an MCSTP is considered where availability and demand parameters follow general form of distribution and a generalized equivalent deterministic model (GMCSTP) of MCSTP is obtained. It is also shown that all previous models obtained by different authors can be deduced with the help of GMCSTP. MCSTP with pareto, power function or burr-XII distributions are also considered and equivalent deterministic models are obtained. To illustrate the proposed model two numerical examples are presented and solved using LINGO 13.0 software package.

  10. Some aspects of the inverse problem for general first order systems

    International Nuclear Information System (INIS)

    Sarlet, W.; Cantrijn, F.

    1978-01-01

    In this paper we investigate the most general systems of first-order ordinary differential equations which satisfy the integrability conditions of the inverse problem for canonical formulations, i.e., are derivable from a variational principle. It is shown that they have a structure which is invariant under arbitrary coordinate-transformations. A special class of transformations, called identity-isotopic transformations, is described. It is illustrated how these transformations share all properties with classical canonical transformations except one: the solutions of the system, viewed as transformations from the set of initial values, generally are not identity-isotopic. This failure is shown to be due to the explicit time-dependence of the functions which characterise the system, and the special role of this time-dependence is further clarified using the possibility of a reduction to conventional Hamiltonian systems. All properties are derived here within the framework of an analytic treatment of a system of differential equations

  11. A generalized electro-magneto-thermo-elastic problem for an infinitely long solid cylinder

    International Nuclear Information System (INIS)

    Tianhu, H.; Xiaogeng, T.; Yapeng, S.; Tianhu, H.

    2005-01-01

    The theory of generalized thermoelasticity, based on the theory of Lord and Shulman with one relaxation time, is used to study the electro-magneto-thermo-elastic interactions in an infinitely long perfectly conducting solid cylinder subjected to a thermal shock on its surface when the cylinder and its adjoining vacuum is subjected to a uniform axial magnetic field. The cylinder deforms because of thermal shock, and due to the application of the magnetic field, there result an induced magnetic and an induced electric field in the cylinder. The Maxwell's equations are formulated and the generalized electro-magneto-thermo-elastic coupled governing equations are established. By means of the Laplace transform and numerical Laplace inversion the problem is solved. The distributions of the considered temperature, stress, displacement, induced magnetic and electric field are represented graphically. From the distributions, it can be found the electromagnetic-thermoelastic coupled effects and the wave type heat propagation in the medium. This indicates that the generalized heat conduction mechanism is completely different from the classic Fourier's in essence. In generalized thermoelasticity theory heat propagates as a wave with finite velocity instead of infinite velocity in medium. (authors)

  12. The Effect of Using an Explicit General Problem Solving Teaching Approach on Elementary Pre-Service Teachers' Ability to Solve Heat Transfer Problems

    Science.gov (United States)

    Mataka, Lloyd M.; Cobern, William W.; Grunert, Megan L.; Mutambuki, Jacinta; Akom, George

    2014-01-01

    This study investigate the effectiveness of adding an "explicit general problem solving teaching strategy" (EGPS) to guided inquiry (GI) on pre-service elementary school teachers' ability to solve heat transfer problems. The pre-service elementary teachers in this study were enrolled in two sections of a chemistry course for pre-service…

  13. AN ACCURATE ORBITAL INTEGRATOR FOR THE RESTRICTED THREE-BODY PROBLEM AS A SPECIAL CASE OF THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM

    International Nuclear Information System (INIS)

    Minesaki, Yukitaka

    2013-01-01

    For the restricted three-body problem, we propose an accurate orbital integration scheme that retains all conserved quantities of the two-body problem with two primaries and approximately preserves the Jacobi integral. The scheme is obtained by taking the limit as mass approaches zero in the discrete-time general three-body problem. For a long time interval, the proposed scheme precisely reproduces various periodic orbits that cannot be accurately computed by other generic integrators

  14. Communication problems between dementia carers and general practitioners: effect on access to community support services.

    Science.gov (United States)

    Bruce, David G; Paley, Glenys A; Underwood, Peter J; Roberts, David; Steed, Duncan

    2002-08-19

    To investigate the circumstances that led general practitioners to refer dementia sufferers and their carers to community support services. Qualitative study using semi-structured interviews, carried out between 1 September 1999 and 30 April 2000. 21 live-in carers of patients with dementia referred for the first time to a Western Australian metropolitan Aged Care Assessment Team, and 19 of their referring general practitioners. Most referrals occurred after the carers had been experiencing carer stress, and were precipitated by crisis situations. Carers failed to discuss their difficulties with the referring GP for a variety of reasons, including the belief that they should cope because it was their duty. The doctors found it difficult to know how the carers were coping or when to intervene, and some carers tended to resist their attempts to help. Time constraints were a significant problem for both groups. Attitudinal barriers in both carers of patients with dementia and GPs, combined with time constraints, often lead to inadequate assessment of carer problems. While it is important that strategies to improve communication between carers and GPs are developed, it would be sensible for GPs to assume that dementia carers are at risk of carer stress and should be encouraged to use community care services.

  15. Efficient Greedy Randomized Adaptive Search Procedure for the Generalized Regenerator Location Problem

    Directory of Open Access Journals (Sweden)

    J.D. Quintana

    2016-12-01

    Full Text Available Over the years, there has been an evolution in the manner in which we perform traditional tasks. Nowadays, almost every simple action that we can think about involves the connection among two or more devices. It is desirable to have a high quality connection among devices, by using electronic or optical signals. Therefore, it is really important to have a reliable connection among terminals in the network. However, the transmission of the signal deteriorates when increasing the distance among devices. There exists a special piece of equipment that we can deploy in a network, called regenerator, which is able to restore the signal transmitted through it, in order to maintain its quality. Deploying a regenerator in a network is generally expensive, so it is important to minimize the number of regenerators used. In this paper we focus on the Generalized Regenerator Location Problem (GRLP, which tries to innd the minimum number of regenerators that must be deployed in a network in order to have a reliable communication without loss of quality. We present a GRASP metaheuristic in order to innd good solutions for the GRLP. The results obtained by the proposal are compared with the best previous methods for this problem. We conduct an extensive computational experience with 60 large and challenging instances, emerging the proposed method as the best performing one. This fact is innally supported by non-parametric statistical tests.

  16. Equihash: Asymmetric Proof-of-Work Based on the Generalized Birthday Problem

    Directory of Open Access Journals (Sweden)

    Alex Biryukov

    2017-04-01

    Full Text Available Proof-of-work is a central concept in modern cryptocurrencies and denial-ofservice protection tools, but the requirement for fast verification so far has made it an easy prey for GPU-, ASIC-, and botnet-equipped users. The attempts to rely on memory-intensive computations in order to remedy the disparity between architectures have resulted in slow or broken schemes. In this paper we solve this open problem and show how to construct an asymmetric proof-of-work (PoW based on a computationally-hard problem, which requires a great deal of memory to generate a proof (called a ”memory-hardness” feature but is instant to verify. Our primary proposal, Equihash, is a PoW based on the generalized birthday problem and enhanced Wagner’s algorithm for it. We introduce the new technique of algorithm binding to prevent cost amortization and demonstrate that possible parallel implementations are constrained by memory bandwidth. Our scheme has tunable and steep time-space tradeoffs, which impose large computational penalties if less memory is used. Our solution is practical and ready to deploy: a reference implementation of a proof-of-work requiring 700 MB of RAM runs in 15 seconds on a 2.1 GHz CPU, increases the computations by a factor of 1000 if memory is halved, and presents a proof of just 120 bytes long.

  17. An analysis of the Rayleigh–Stokes problem for a generalized second-grade fluid

    KAUST Repository

    Bazhlekova, Emilia

    2014-11-26

    © 2014, The Author(s). We study the Rayleigh–Stokes problem for a generalized second-grade fluid which involves a Riemann–Liouville fractional derivative in time, and present an analysis of the problem in the continuous, space semidiscrete and fully discrete formulations. We establish the Sobolev regularity of the homogeneous problem for both smooth and nonsmooth initial data v, including v∈L2(Ω). A space semidiscrete Galerkin scheme using continuous piecewise linear finite elements is developed, and optimal with respect to initial data regularity error estimates for the finite element approximations are derived. Further, two fully discrete schemes based on the backward Euler method and second-order backward difference method and the related convolution quadrature are developed, and optimal error estimates are derived for the fully discrete approximations for both smooth and nonsmooth initial data. Numerical results for one- and two-dimensional examples with smooth and nonsmooth initial data are presented to illustrate the efficiency of the method, and to verify the convergence theory.

  18. An analysis of the Rayleigh–Stokes problem for a generalized second-grade fluid

    KAUST Repository

    Bazhlekova, Emilia; Jin, Bangti; Lazarov, Raytcho; Zhou, Zhi

    2014-01-01

    © 2014, The Author(s). We study the Rayleigh–Stokes problem for a generalized second-grade fluid which involves a Riemann–Liouville fractional derivative in time, and present an analysis of the problem in the continuous, space semidiscrete and fully discrete formulations. We establish the Sobolev regularity of the homogeneous problem for both smooth and nonsmooth initial data v, including v∈L2(Ω). A space semidiscrete Galerkin scheme using continuous piecewise linear finite elements is developed, and optimal with respect to initial data regularity error estimates for the finite element approximations are derived. Further, two fully discrete schemes based on the backward Euler method and second-order backward difference method and the related convolution quadrature are developed, and optimal error estimates are derived for the fully discrete approximations for both smooth and nonsmooth initial data. Numerical results for one- and two-dimensional examples with smooth and nonsmooth initial data are presented to illustrate the efficiency of the method, and to verify the convergence theory.

  19. The general linear thermoelastic end problem for solid and hollow cylinders

    International Nuclear Information System (INIS)

    Thompson, J.J.; Chen, P.Y.P.

    1977-01-01

    This paper reports on three topics arising from work in progress on theoretical and computational aspects of the utilization of self equilibrating and load stress systems, to solve thermoelastic problems of finite, or semi-infinite, solid or hollow circular cylinders, with particular reference to the pellets, rods, tubes and shells with arbitrary internal heat generation encountered in Nuclear Reactor Technology. Specifically the work is aimed at the evaluation of stress intensification factors in the end elastic boundary layer region, due to various thermal and mechanical end load conditions, in relation to the external, exact stress solutions, which satisfy conditions on the curved surfaces only and are valid over the remainder of the cylindrical body. More generally, it is possible, at least for symmetric thermoelastic problems, to derive exact external solutions, using self equilibrating end load systems, which describe the stress/displacement state completely as a combination of a simple local plane strain solution and a correction dependent on the magnitude of axial thermal gradients. Thus plane strain, and self equilibrating end load systems are sufficient for the complete external and boundary layer solution of a finite cylindrical body. This formulation is capable of further extension, e.g., to concentric multi-region problems, and provides a useful approach to the study of local stress intensification factors due to thermal perturbations

  20. Optimal Stochastic Control Problem for General Linear Dynamical Systems in Neuroscience

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2017-01-01

    Full Text Available This paper considers a d-dimensional stochastic optimization problem in neuroscience. Suppose the arm’s movement trajectory is modeled by high-order linear stochastic differential dynamic system in d-dimensional space, the optimal trajectory, velocity, and variance are explicitly obtained by using stochastic control method, which allows us to analytically establish exact relationships between various quantities. Moreover, the optimal trajectory is almost a straight line for a reaching movement; the optimal velocity bell-shaped and the optimal variance are consistent with the experimental Fitts law; that is, the longer the time of a reaching movement, the higher the accuracy of arriving at the target position, and the results can be directly applied to designing a reaching movement performed by a robotic arm in a more general environment.

  1. The Anderson localization problem, the Fermi-Pasta-Ulam paradox and the generalized diffusion approach

    International Nuclear Information System (INIS)

    Kuzovkov, V N

    2011-01-01

    The goal of this paper is twofold. First, based on the interpretation of a quantum tight-binding model in terms of a classical Hamiltonian map, we consider the Anderson localization (AL) problem as the Fermi-Pasta-Ulam (FPU) effect in a modified dynamical system containing both stable and unstable (inverted) modes. Delocalized states in the AL are analogous to the stable quasi-periodic motion in FPU, whereas localized states are analogous to thermalization, respectively. The second aim is to use the classical Hamilton map for a simplified derivation of exact equations for the localization operator H(z). The latter was presented earlier (Kuzovkov et al 2002 J. Phys.: Condens. Matter 14 13777) treating the AL as a generalized diffusion in a dynamical system. We demonstrate that counter-intuitive results of our studies of the AL are similar to the FPU counter-intuitivity.

  2. Normal Mode Analysis to a Poroelastic Half-Space Problem under Generalized Thermoelasticity

    Directory of Open Access Journals (Sweden)

    Chunbao Xiong

    Full Text Available Abstract The thermo-hydro-mechanical problems associated with a poroelastic half-space soil medium with variable properties under generalized thermoelasticity theory were investigated in this study. By remaining faithful to Biot’s theory of dynamic poroelasticity, we idealized the foundation material as a uniform, fully saturated, poroelastic half-space medium. We first subjected this medium to time harmonic loads consisting of normal or thermal loads, then investigated the differences between the coupled thermohydro-mechanical dynamic models and the thermo-elastic dynamic models. We used normal mode analysis to solve the resulting non-dimensional coupled equations, then investigated the effects that non-dimensional vertical displacement, excess pore water pressure, vertical stress, and temperature distribution exerted on the poroelastic half-space medium and represented them graphically.

  3. The Anderson localization problem, the Fermi-Pasta-Ulam paradox and the generalized diffusion approach

    Science.gov (United States)

    Kuzovkov, V. N.

    2011-12-01

    The goal of this paper is twofold. First, based on the interpretation of a quantum tight-binding model in terms of a classical Hamiltonian map, we consider the Anderson localization (AL) problem as the Fermi-Pasta-Ulam (FPU) effect in a modified dynamical system containing both stable and unstable (inverted) modes. Delocalized states in the AL are analogous to the stable quasi-periodic motion in FPU, whereas localized states are analogous to thermalization, respectively. The second aim is to use the classical Hamilton map for a simplified derivation of exact equations for the localization operator H(z). The latter was presented earlier (Kuzovkov et al 2002 J. Phys.: Condens. Matter 14 13777) treating the AL as a generalized diffusion in a dynamical system. We demonstrate that counter-intuitive results of our studies of the AL are similar to the FPU counter-intuitivity.

  4. An Optimal Order Nonnested Mixed Multigrid Method for Generalized Stokes Problems

    Science.gov (United States)

    Deng, Qingping

    1996-01-01

    A multigrid algorithm is developed and analyzed for generalized Stokes problems discretized by various nonnested mixed finite elements within a unified framework. It is abstractly proved by an element-independent analysis that the multigrid algorithm converges with an optimal order if there exists a 'good' prolongation operator. A technique to construct a 'good' prolongation operator for nonnested multilevel finite element spaces is proposed. Its basic idea is to introduce a sequence of auxiliary nested multilevel finite element spaces and define a prolongation operator as a composite operator of two single grid level operators. This makes not only the construction of a prolongation operator much easier (the final explicit forms of such prolongation operators are fairly simple), but the verification of the approximate properties for prolongation operators is also simplified. Finally, as an application, the framework and technique is applied to seven typical nonnested mixed finite elements.

  5. A Generalized Measure for the Optimal Portfolio Selection Problem and its Explicit Solution

    Directory of Open Access Journals (Sweden)

    Zinoviy Landsman

    2018-03-01

    Full Text Available In this paper, we offer a novel class of utility functions applied to optimal portfolio selection. This class incorporates as special cases important measures such as the mean-variance, Sharpe ratio, mean-standard deviation and others. We provide an explicit solution to the problem of optimal portfolio selection based on this class. Furthermore, we show that each measure in this class generally reduces to the efficient frontier that coincides or belongs to the classical mean-variance efficient frontier. In addition, a condition is provided for the existence of the a one-to-one correspondence between the parameter of this class of utility functions and the trade-off parameter λ in the mean-variance utility function. This correspondence essentially provides insight into the choice of this parameter. We illustrate our results by taking a portfolio of stocks from National Association of Securities Dealers Automated Quotation (NASDAQ.

  6. An efficient heuristic versus a robust hybrid meta-heuristic for general framework of serial-parallel redundancy problem

    International Nuclear Information System (INIS)

    Sadjadi, Seyed Jafar; Soltani, R.

    2009-01-01

    We present a heuristic approach to solve a general framework of serial-parallel redundancy problem where the reliability of the system is maximized subject to some general linear constraints. The complexity of the redundancy problem is generally considered to be NP-Hard and the optimal solution is not normally available. Therefore, to evaluate the performance of the proposed method, a hybrid genetic algorithm is also implemented whose parameters are calibrated via Taguchi's robust design method. Then, various test problems are solved and the computational results indicate that the proposed heuristic approach could provide us some promising reliabilities, which are fairly close to optimal solutions in a reasonable amount of time.

  7. LAGRANGE SOLUTIONS TO THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM

    International Nuclear Information System (INIS)

    Minesaki, Yukitaka

    2013-01-01

    There is no known integrator that yields exact orbits for the general three-body problem (G3BP). It is difficult to verify whether a numerical procedure yields the correct solutions to the G3BP because doing so requires knowledge of all 11 conserved quantities, whereas only six are known. Without tracking all of the conserved quantities, it is possible to show that the discrete general three-body problem (d-G3BP) yields the correct orbits corresponding to Lagrange solutions of the G3BP. We show that the d-G3BP yields the correct solutions to the G3BP for two special cases: the equilateral triangle and collinear configurations. For the triangular solution, we use the fact that the solution to the three-body case is a superposition of the solutions to the three two-body cases, and we show that the three bodies maintain the same relative distances at all times. To obtain the collinear solution, we assume a specific permutation of the three bodies arranged along a straight rotating line, and we show that the d-G3BP maintains the same distance ratio between two bodies as in the G3BP. Proving that the d-G3BP solutions for these cases are equivalent to those of the G3BP makes it likely that the d-G3BP and G3BP solutions are equivalent in other cases. To our knowledge, this is the first work that proves the equivalence of the discrete solutions and the Lagrange orbits.

  8. A Generalized Mathematical Model for the Fracture Problem of the Suspended Highway

    Directory of Open Access Journals (Sweden)

    Zhao Ying

    2017-01-01

    Full Text Available In order to answer dangling fracture problems of highway, the suspended pavement equivalent for non - suspended pavement, through the special boundary conditions has been suspended highway stress field of expression, in accordance with the 3D fracture model of crack formation, and establish a vacant, a general mathematics model for fracture problems of highway and analysis in highway suspended segment weight and vehicle load limit of highway capacity of Pu For overturning road inPu is less than the force of carrying more than compared to the work and fruit Bridge Hydropower Station Road engineering examples to verify suspended highway should force field expressions for the correctness and applicability. The results show that: when the hanging ratio R 0. 243177 limits of Pu design axle load 100kN. When the vertical crack in the vacant in the direction of length greater than 0. 1, the ultimate bearing capacity is less than the design axle load 100kN; when the hanging ratio R is less than 0. 5, the road to local fracture, the ultimate bearing capacity of suspended stress field expressions in solution; when the hanging ratio is greater than or equal to 0. 5, the road does not reach the limit bearing capacity of the whole body; torque shear surface of the effect is far less than the bending moments on shear planes.

  9. Recruitment and retention of general practitioners in the UK: what are the problems and solutions?

    Science.gov (United States)

    Young, R; Leese, B

    1999-10-01

    Recruitment and retention of general practitioners (GPs) has become an issue of major concern in recent years. However, much of the evidence is anecdotal and some commentators continue to question the scale of workforce problems. Hence, there is a need to establish a clear picture of those instabilities (i.e. imbalances between demand and supply) that do exist in the GP labour market in the UK. Based on a review of the published literature, we identify problems that stem from: (i) the changing social composition of the workforce and the fact that a large proportion of qualified GPs are significantly underutilized within traditional career structures; and (ii) the considerable differences in the ability of local areas to match labour demand and supply. We argue that one way to address these problems would be to encourage greater flexibility in a number of areas highlighted in the literature: (i) time commitment across the working day and week; (ii) long-term career paths; (iii) training and education; and (iv) remuneration and contract conditions. Overall, although the evidence suggests that the predicted 'crisis' has not yet occurred in the GP labour market as a whole, there is no room for lack of imagination in planning terms. Workforce planners continue to emphasize national changes to the medical school intake as the means to balance labour demand and supply between the specialities; however, better retention and deployment of existing GP labour would arguably produce more effective supply-side solutions. In this context, current policy and practice developments (e.g. Primary Care Groups and Primary Care Act Pilot Sites) offer a unique learning base upon which to move forward.

  10. Solving the patient zero inverse problem by using generalized simulated annealing

    Science.gov (United States)

    Menin, Olavo H.; Bauch, Chris T.

    2018-01-01

    Identifying patient zero - the initially infected source of a given outbreak - is an important step in epidemiological investigations of both existing and emerging infectious diseases. Here, the use of the Generalized Simulated Annealing algorithm (GSA) to solve the inverse problem of finding the source of an outbreak is studied. The classical disease natural histories susceptible-infected (SI), susceptible-infected-susceptible (SIS), susceptible-infected-recovered (SIR) and susceptible-infected-recovered-susceptible (SIRS) in a regular lattice are addressed. Both the position of patient zero and its time of infection are considered unknown. The algorithm performance with respect to the generalization parameter q˜v and the fraction ρ of infected nodes for whom infection was ascertained is assessed. Numerical experiments show the algorithm is able to retrieve the epidemic source with good accuracy, even when ρ is small, but present no evidence to support that GSA performs better than its classical version. Our results suggest that simulated annealing could be a helpful tool for identifying patient zero in an outbreak where not all cases can be ascertained.

  11. Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics

    NARCIS (Netherlands)

    Sweller, John; Clark, Richard; Kirschner, Paul A.

    2010-01-01

    Sweller, J., Clark, R., & Kirschner, P. A. (2010). Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics. Notices of the American Mathematical Society, 57, 1303-1304.

  12. The Distracted Brain : The neurobiology and neuropsychology of attention-deficit/hyperactivity problems in the general population

    NARCIS (Netherlands)

    S.E. Mous (Sabine)

    2015-01-01

    markdownabstractThis thesis focuses on the neurobiology and neuropsychology of attention-deficit/hyperactivity problems in the general population. The notion that child psychopathology might be better described within a dimensional framework, rather than with clearly defined diagnostic categories,

  13. Non-right-handedness and mental health problems among adolescents from the general population : The Trails Study

    NARCIS (Netherlands)

    van der Hoorn, Anouk; Oldehinkel, A.J.; Ormel, J.; Bruggeman, R; Uiterwaal, C.S.P.M.; Burger, Huib

    2010-01-01

    To determine whether the association between non-right-handedness and mental problems among adolescents is specific for psychotic symptoms, we included a group of 2096 adolescents with a mean age of 14 years from the general population. Mental health problems were assessed using the parent,

  14. Generalized Uncertainty Quantification for Linear Inverse Problems in X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, Michael James [Clarkson Univ., Potsdam, NY (United States)

    2014-04-25

    In industrial and engineering applications, X-ray radiography has attained wide use as a data collection protocol for the assessment of material properties in cases where direct observation is not possible. The direct measurement of nuclear materials, particularly when they are under explosive or implosive loading, is not feasible, and radiography can serve as a useful tool for obtaining indirect measurements. In such experiments, high energy X-rays are pulsed through a scene containing material of interest, and a detector records a radiograph by measuring the radiation that is not attenuated in the scene. One approach to the analysis of these radiographs is to model the imaging system as an operator that acts upon the object being imaged to produce a radiograph. In this model, the goal is to solve an inverse problem to reconstruct the values of interest in the object, which are typically material properties such as density or areal density. The primary objective in this work is to provide quantitative solutions with uncertainty estimates for three separate applications in X-ray radiography: deconvolution, Abel inversion, and radiation spot shape reconstruction. For each problem, we introduce a new hierarchical Bayesian model for determining a posterior distribution on the unknowns and develop efficient Markov chain Monte Carlo (MCMC) methods for sampling from the posterior. A Poisson likelihood, based on a noise model for photon counts at the detector, is combined with a prior tailored to each application: an edge-localizing prior for deconvolution; a smoothing prior with non-negativity constraints for spot reconstruction; and a full covariance sampling prior based on a Wishart hyperprior for Abel inversion. After developing our methods in a general setting, we demonstrate each model on both synthetically generated datasets, including those from a well known radiation transport code, and real high energy radiographs taken at two U. S. Department of Energy

  15. Generalized Galilean transformations and the measurement problem in the entropic dynamics approach to quantum theory

    Science.gov (United States)

    Johnson, David T.

    Quantum mechanics is an extremely successful and accurate physical theory, yet since its inception, it has been afflicted with numerous conceptual difficulties. The primary subject of this thesis is the theory of entropic quantum dynamics (EQD), which seeks to avoid these conceptual problems by interpreting quantum theory from an informational perspective. We begin by reviewing Cox's work in describing probability theory as a means of rationally and consistently quantifying uncertainties. We then discuss how probabilities can be updated according to either Bayes' theorem or the extended method of maximum entropy (ME). After that discussion, we review the work of Caticha and Giffin that shows that Bayes' theorem is a special case of ME. This important result demonstrates that the ME method is the general method for updating probabilities. We then review some motivating difficulties in quantum mechanics before discussing Caticha's work in deriving quantum theory from the approach of entropic dynamics, which concludes our review. After entropic dynamics is introduced, we develop the concepts of symmetries and transformations from an informational perspective. The primary result is the formulation of a symmetry condition that any transformation must satisfy in order to qualify as a symmetry in EQD. We then proceed to apply this condition to the extended Galilean transformation. This transformation is of interest as it exhibits features of both special and general relativity. The transformation yields a gravitational potential that arises from an equivalence of information. We conclude the thesis with a discussion of the measurement problem in quantum mechanics. We discuss the difficulties that arise in the standard quantum mechanical approach to measurement before developing our theory of entropic measurement. In entropic dynamics, position is the only observable. We show how a theory built on this one observable can account for the multitude of measurements present in

  16. Overweight in adolescent, psychiatric inpatients: A problem of general or food-specific impulsivity?

    Science.gov (United States)

    Deux, Natalie; Schlarb, Angelika A; Martin, Franziska; Holtmann, Martin; Hebebrand, Johannes; Legenbauer, Tanja

    2017-05-01

    Adolescent psychiatric patients are vulnerable to weight problems and show an overrepresentation of overweight compared to the healthy population. One potential factor that can contribute to the etiology of overweight is higher impulsivity. As of yet, it is unclear whether it is a general impulse control deficit or weight-related aspects such as lower impulse control in response to food that have an impact on body weight. As this may have therapeutic implications, the current study investigated differences between overweight and non-overweight adolescent psychiatric inpatients (N = 98; aged 12-20) in relation to trait impulsivity and behavioral inhibition performance. The Barratt Impulsiveness Scale and two go/no-go paradigms with neutral and food-related stimulus materials were applied. Results indicated no significant differences concerning trait impulsivity, but revealed that overweight inpatients had significantly more difficulties in inhibition performance (i.e. they reacted more impulsively) in response to both food and neutral stimuli compared to non-overweight inpatients. Furthermore, no specific inhibition deficit for high-caloric vs. low-caloric food cues emerged in overweight inpatients, whereas non-overweight participants showed significantly lower inhibition skills in response to high-caloric than low-caloric food stimuli. The results highlight a rather general, non-food-specific reduced inhibition performance in an overweight adolescent psychiatric population. Further research is necessary to enhance the understanding of the role of impulsivity in terms of body weight status in this high-risk group of adolescent inpatients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. General Physical Problems Related to MHD. Shock Tubes. Introduction to Papers in Section 1-b

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-10-15

    The papers which will be considered here are Nos. SM-74/26, 134, 172, 182 and 219. Each of the five papers will be discussed in turn, but before beginning this discussion, some general comments concerning shock tube studies of MHD generator plasmas seem in order. There is little doubt that the shock tube is an excellent facility-for the study of the basic processes which occur in the bulk of the plasma. It provides a large flow of uniform plasma with well-controlled properties. Because of the very short operating times, the materials problems, which plague continuously operating facilities, are eliminated. Depending upon the mode of operation of the shock tube, the gas dynamic conditions of an MHD generator may also be simulated more or less well. Three different modes have been used by the authors of the present papers. Abbas and Howatson have carried out their measurements in the driver plasma of an electrical shock tube. Both Zauderer and Mori, Kawada, Yamamoto and Imani have used the more conventional technique of experimenting in the plasma produced by the incident shock. Louis uses the plasma produced by reflection of the shock wave from the tube-end as a plasma source for the MHD channel.

  18. Illustrating chaos: a schematic discretization of the general three-body problem in Newtonian gravity

    Science.gov (United States)

    Leigh, Nathan W. C.; Wegsman, Shalma

    2018-05-01

    We present a formalism for constructing schematic diagrams to depict chaotic three-body interactions in Newtonian gravity. This is done by decomposing each interaction into a series of discrete transformations in energy- and angular momentum-space. Each time a transformation is applied, the system changes state as the particles re-distribute their energy and angular momenta. These diagrams have the virtue of containing all of the quantitative information needed to fully characterize most bound or unbound interactions through time and space, including the total duration of the interaction, the initial and final stable states in addition to every intervening temporary meta-stable state. As shown via an illustrative example for the bound case, prolonged excursions of one of the particles, which by far dominates the computational cost of the simulations, are reduced to a single discrete transformation in energy- and angular momentum-space, thereby potentially mitigating any computational expense. We further generalize our formalism to sequences of (unbound) three-body interactions, as occur in dense stellar environments during binary hardening. Finally, we provide a method for dynamically evolving entire populations of binaries via three-body scattering interactions, using a purely analytic formalism. In principle, the techniques presented here are adaptable to other three-body problems that conserve energy and angular momentum.

  19. Direct and inverse problems for the generalized relativistic Toda lattice and the connection with general orthogonal polynomials

    International Nuclear Information System (INIS)

    Gago-Alonso, A; Santiago-Moreno, L; Piñeiro-Díaz, L R

    2008-01-01

    We study finite nonlinear dynamical systems that are somehow more general and complex than the relativistic Toda lattice. Our dynamical systems have a matrix representation very similar to the ones that were previously studied. It is defined in terms of a one-parameter family (D(x), M(x)) of matrices, where D(x) is a Hessenberg matrix and M(x) is a lower triangular matrix. The Jordan matrix associated with M −1 (x)D(x) is a constant of motion and the auxiliary spectral data have explicit time evolution. Using the connection between Hessenberg matrices and general orthogonal polynomials we associated to our system a one-parameter family of scalar products that we use to prove the integrability of the system. In particular the inverse transform is given by an orthogonalization process on a given scalar product

  20. The role of general cognitive ability in moderating the relation of adverse life events to emotional and behavioural problems.

    Science.gov (United States)

    Flouri, Eirini; Mavroveli, Stella; Panourgia, Constantina

    2013-02-01

    Previous studies have established the role of various measures of cognitive functioning in dampening the association between adverse life events ('life stress') and adolescents' emotional and behavioural problems. However, it is not yet clear if general cognitive ability ('intelligence') is a protective factor. In this study of 1,175 10- to 19-year-olds in five secondary schools in England, we explored this issue. We found that even after controlling for sex, age, family poverty, and special educational needs, the association of life stress with emotional, hyperactivity, and conduct problems was significant. General cognitive ability moderated the association between life stress and conduct problems; among adolescents with higher than average general cognitive ability, the association between life stress and conduct problems was non-significant. © 2012 The British Psychological Society.

  1. The limit passage of space curvature in problems of celestial mechanics with the generalized Kepler and Hooke potentials

    Science.gov (United States)

    Vozmishcheva, Tatiana

    2016-09-01

    The connection between the problems of celestial mechanics: the Kepler problem, the two-center problem and the two body problem in spaces of constant curvature with the generalized Kepler and Hooke potentials is investigated. The limit passage in the two-center and two body problems in the Lobachevsky space and on a sphere is carried out as λto0 (λ is the curvature of the corresponding space) for the two potentials. The potentials and metrics in spaces under study are written in the gnomonic coordinates. It is shown that as the curvature radius tends to infinity, the generalized gravitational and elastic potentials transform to the Kepler and Hooke forms in the Euclidean space.

  2. Generalization of Abel's mechanical problem: The extended isochronicity condition and the superposition principle

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Tohru, E-mail: kinugawa@phoenix.kobe-u.ac.jp [Institute for Promotion of Higher Education, Kobe University, Kobe 657-8501 (Japan)

    2014-02-15

    This paper presents a simple but nontrivial generalization of Abel's mechanical problem, based on the extended isochronicity condition and the superposition principle. There are two primary aims. The first one is to reveal the linear relation between the transit-time T and the travel-length X hidden behind the isochronicity problem that is usually discussed in terms of the nonlinear equation of motion (d{sup 2}X)/(dt{sup 2}) +(dU)/(dX) =0 with U(X) being an unknown potential. Second, the isochronicity condition is extended for the possible Abel-transform approach to designing the isochronous trajectories of charged particles in spectrometers and/or accelerators for time-resolving experiments. Our approach is based on the integral formula for the oscillatory motion by Landau and Lifshitz [Mechanics (Pergamon, Oxford, 1976), pp. 27–29]. The same formula is used to treat the non-periodic motion that is driven by U(X). Specifically, this unknown potential is determined by the (linear) Abel transform X(U) ∝ A[T(E)], where X(U) is the inverse function of U(X), A=(1/√(π))∫{sub 0}{sup E}dU/√(E−U) is the so-called Abel operator, and T(E) is the prescribed transit-time for a particle with energy E to spend in the region of interest. Based on this Abel-transform approach, we have introduced the extended isochronicity condition: typically, τ = T{sub A}(E) + T{sub N}(E) where τ is a constant period, T{sub A}(E) is the transit-time in the Abel type [A-type] region spanning X > 0 and T{sub N}(E) is that in the Non-Abel type [N-type] region covering X < 0. As for the A-type region in X > 0, the unknown inverse function X{sub A}(U) is determined from T{sub A}(E) via the Abel-transform relation X{sub A}(U) ∝ A[T{sub A}(E)]. In contrast, the N-type region in X < 0 does not ensure this linear relation: the region is covered with a predetermined potential U{sub N}(X) of some arbitrary choice, not necessarily obeying the Abel-transform relation. In

  3. Global gradient estimates for divergence-type elliptic problems involving general nonlinear operators

    Science.gov (United States)

    Cho, Yumi

    2018-05-01

    We study nonlinear elliptic problems with nonstandard growth and ellipticity related to an N-function. We establish global Calderón-Zygmund estimates of the weak solutions in the framework of Orlicz spaces over bounded non-smooth domains. Moreover, we prove a global regularity result for asymptotically regular problems which are getting close to the regular problems considered, when the gradient variable goes to infinity.

  4. A problem of finding an acceptable variant in generalized project networks

    Directory of Open Access Journals (Sweden)

    David Blokh

    2005-01-01

    Full Text Available A project network often has some activities or groups of activities which can be performed at different stages of the project. Then, the problem of finding an optimal/acceptable time or/and optimal/acceptable order of such an activity or a group of activities arises. Such a problem emerges, in particular, in house-building management when the beginnings of some activities may vary in time or/and order. We consider a mathematical formulation of the problem, show its computational complexity, and describe an algorithm for solving the problem.

  5. Piping benchmark problems for the General Electric Advanced Boiling Water Reactor

    International Nuclear Information System (INIS)

    Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K.

    1993-08-01

    To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for an advanced boiling water reactor standard design, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the advanced reactor standard design. It will be required that the combined license holders demonstrate that their solutions to these problems are in agreement with the benchmark problem set

  6. A self-help problem-solving video for parents and teens : social validity and generalization of acquired skills

    OpenAIRE

    Hook, Richard J.

    1993-01-01

    A self-administered problem-solving skill training video for nonclinical families with teens is evaluated. The study focuses on the generalization of skills to naturalistic family conversations and the program's social validity: potential iatrogenic aggravation of family problems, perceived effectiveness, and program enjoyment. Seventy families with young teens were randomly assigned to two treatment groups. One group (skill) viewed a skill training program that included information about ...

  7. Markers for context-responsiveness: Client baseline interpersonal problems moderate the efficacy of two psychotherapies for generalized anxiety disorder.

    Science.gov (United States)

    Gomez Penedo, Juan Martin; Constantino, Michael J; Coyne, Alice E; Westra, Henny A; Antony, Martin M

    2017-10-01

    To follow-up a randomized clinical trial that compared the acute and long-term efficacy of 15 sessions of cognitive-behavioral therapy (CBT) versus CBT integrated with motivational interviewing (MI) for severe generalized anxiety disorder (GAD; Westra, Constantino, & Antony, 2016), we (a) characterized the sample's baseline interpersonal problems, and (b) analyzed the role of several theory-relevant problems as moderators of the comparative treatment effects on outcome. We first compared clients' (N = 85) baseline interpersonal problems profile to a general clinical sample. We next conducted piecewise, 2-level growth models to analyze the interactive effects of treatment condition and the hypothesized interpersonal problem indices of nonassertiveness (ranging from low to high), exploitability (ranging from low to high on this specific combination of nonassertiveness and friendliness), and overall agency (ranging from more problems of being too submissive to more problems of being too domineering, including friendly or hostile variants) on acute and follow-up worry reduction. Finally, we conducted hierarchical generalized linear models to examine these interactive effects on the likelihood of achieving clinically meaningful worry reduction across follow-up. As expected, the GAD clients evidenced more nonassertive and exploitable interpersonal problems than the general clinical sample. Also as predicted, clients with more problematic nonassertiveness and low overall agency in their relationships had greater follow-up worry reduction in MI-CBT versus CBT, including to a clinically significant degree for the agency by treatment interaction. GAD-specific interpersonal problems can serve as contextual markers for integrative treatment selection and planning. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Population Problems: A Constituent of General Culture in the 21st Century.

    Science.gov (United States)

    Rath, Ferdinand J. C. M.

    1993-01-01

    Compares modern population problems with those of previous generations. Examines variations in population problems in different countries and world regions and the ways in which demographic events (e.g., rapid population growth or urbanization) in one region affect other regions. Advocates preparing for demographic changes through education. (DMM)

  9. Does neuroticism explain variations in care service use for mental health problems in the general population?

    NARCIS (Netherlands)

    ten Have, M; Oldehinkel, A; Vollebergh, W; Ormel, J

    Little is known about the role of personality characteristics in service utilisation for mental health problems. We investigate whether neuroticism: 1) predicts the use of primary and specialised care services for mental health problems, independently of whether a person has an emotional disorder;

  10. A Generalization of the Aumann-Shapley Value for Risk Capital Allocation Problems

    NARCIS (Netherlands)

    Boonen, T.J.; De Waegenaere, A.M.B.; Norde, H.W.

    2012-01-01

    Abstract: This paper analyzes risk capital allocation problems. For risk capital allocation problems, the aim is to allocate the risk capital of a firm to its divisions. Risk capital allocation is of central importance in risk-based performance measurement. We consider a case in which the aggregate

  11. Consultations for women's health problems: factors influencing women's choice of sex of general practitioner.

    NARCIS (Netherlands)

    Brink-Muinen, A. van den; Bakker, D.H. de; Bensing, J.M.

    1994-01-01

    AIM. This study set out to examine the degree to which women choose to visit a woman doctor for women's health problems and the determinants of this choice. The differences between women and men doctors with regard to treating women's health problems were also studied. METHOD. Data from the Dutch

  12. General problems associated with the control and safe use of radiation sources (199)

    International Nuclear Information System (INIS)

    Ahmed, J.U.

    1993-01-01

    There are problems at various levels in ensuring safety in the use of radiation sources. A relatively new problem that warrants international action is the smuggling of radioactive material across international borders. An international convention on the control and safe use of radiation sources is essential to provide a universally harmonized mechanism for ensuring safety

  13. Solving large nonlinear generalized eigenvalue problems from Density Functional Theory calculations in parallel

    DEFF Research Database (Denmark)

    Bendtsen, Claus; Nielsen, Ole Holm; Hansen, Lars Bruno

    2001-01-01

    The quantum mechanical ground state of electrons is described by Density Functional Theory, which leads to large minimization problems. An efficient minimization method uses a self-consistent field (SCF) solution of large eigenvalue problems. The iterative Davidson algorithm is often used, and we...

  14. Comonotonic approximations for a generalized provisioning problem with application to optimal portfolio selection

    NARCIS (Netherlands)

    van Weert, K.; Dhaene, J.; Goovaerts, M.

    2011-01-01

    In this paper we discuss multiperiod portfolio selection problems related to a specific provisioning problem. Our results are an extension of Dhaene et al. (2005) [14], where optimal constant mix investment strategies are obtained in a provisioning and savings context, using an analytical approach

  15. A nodal method applied to a diffusion problem with generalized coefficients

    International Nuclear Information System (INIS)

    Laazizi, A.; Guessous, N.

    1999-01-01

    In this paper, we consider second order neutrons diffusion problem with coefficients in L ∞ (Ω). Nodal method of the lowest order is applied to approximate the problem's solution. The approximation uses special basis functions in which the coefficients appear. The rate of convergence obtained is O(h 2 ) in L 2 (Ω), with a free rectangular triangulation. (authors)

  16. Health problems of victims before and after disaster: a longitudinal study in general practice.

    NARCIS (Netherlands)

    Yzermans, C.J.; Donker, G.A.; Kerssens, J.J.; Dirkzwager, A.J.E.; Soeteman, R.J.H.; Veen, P.M.H. ten

    2005-01-01

    BACKGROUND: We aimed to quantify the health problems and to assess the possible risk factors for developing health problems in persons affected by the explosion of a firework depot at Enschede, The Netherlands, on May 13, 2000. The explosion considerably damaged buildings in the local neighbourhood

  17. Generalized Euler-Lagrange Equations for Fuzzy Fractional Variational Problems under gH-Atangana-Baleanu Differentiability

    Directory of Open Access Journals (Sweden)

    Jianke Zhang

    2018-01-01

    Full Text Available We study in this paper the Atangana-Baleanu fractional derivative of fuzzy functions based on the generalized Hukuhara difference. Under the condition of gH-Atangana-Baleanu fractional differentiability, we prove the generalized necessary and sufficient optimality conditions for problems of the fuzzy fractional calculus of variations with a Lagrange function. The new kernel of gH-Atangana-Baleanu fractional derivative has no singularity and no locality, which was not precisely illustrated in the previous definitions.

  18. Interpersonal Problems, Mindfulness, and Therapy Outcome in an Acceptance-Based Behavior Therapy for Generalized Anxiety Disorder.

    Science.gov (United States)

    Millstein, Daniel J; Orsillo, Susan M; Hayes-Skelton, Sarah A; Roemer, Lizabeth

    2015-01-01

    To better understand the role interpersonal problems play in response to two treatments for generalized anxiety disorder (GAD); an acceptance-based behavior therapy (ABBT) and applied relaxation (AR), and to examine how the development of mindfulness may be related to change in interpersonal problems over treatment and at follow-up. Eighty-one individuals diagnosed with GAD (65.4% female, 80.2% identified as white, average age 32.92) were randomized to receive 16 sessions of either ABBT or AR. GAD severity, interpersonal problems, and mindfulness were measured at pre-treatment, post-treatment, 6-month follow-up, and 12-month follow-up. Mixed effect regression models did not reveal any significant effects of pre-treatment interpersonal problems on GAD severity over treatment. After controlling for post-treatment GAD severity, remaining post-treatment interpersonal problems predicted 6- but not 12-month GAD severity. Participants in both conditions experienced a large decrease in interpersonal problems over treatment. Increases in mindfulness over treatment and through follow-up were associated with decreases in interpersonal problems, even when accounting for reductions in overall GAD severity. Interpersonal problems may be an important target of treatment in GAD, even if pre-treatment interpersonal problems are not predictive of outcome. Developing mindfulness in individuals with GAD may help ameliorate interpersonal difficulties among this population.

  19. Level of satisfaction of older persons with their general practitioner and practice: role of complexity of health problems.

    Directory of Open Access Journals (Sweden)

    Antonius J Poot

    Full Text Available BACKGROUND: Satisfaction is widely used to evaluate and direct delivery of medical care; a complicated relationship exists between patient satisfaction, morbidity and age. This study investigates the relationships between complexity of health problems and level of patient satisfaction of older persons with their general practitioner (GP and practice. METHODS AND FINDINGS: This study is embedded in the ISCOPE (Integrated Systematic Care for Older Persons study. Enlisted patients aged ≥75 years from 59 practices received a written questionnaire to screen for complex health problems (somatic, functional, psychological and social. For 2664 randomly chosen respondents (median age 82 years; 68% female information was collected on level of satisfaction (satisfied, neutral, dissatisfied with their GP and general practice, and demographic and clinical characteristics including complexity of health problems. Of all participants, 4% was dissatisfied with their GP care, 59% neutral and 37% satisfied. Between these three categories no differences were observed in age, gender, country of birth or education level. The percentage of participants dissatisfied with their GP care increased from 0.4% in those with 0 problem domains to 8% in those with 4 domains, i.e. having complex health problems (p<0.001. Per additional health domain with problems, the risk of being dissatisfied increased 1.7 times (95% CI 1.4-2.14; p<0.001. This was independent of age, gender, and demographic and clinical parameters (adjusted OR 1.4, 95% CI 1.1-1.8; p = 0.021. CONCLUSION: In older persons, dissatisfaction with general practice is strongly correlated with rising complexity of health problems, independent of age, demographic and clinical parameters. It remains unclear whether complexity of health problems is a patient characteristic influencing the perception of care, or whether the care is unable to handle the demands of these patients. Prospective studies are needed to

  20. A Simulated Annealing method to solve a generalized maximal covering location problem

    Directory of Open Access Journals (Sweden)

    M. Saeed Jabalameli

    2011-04-01

    Full Text Available The maximal covering location problem (MCLP seeks to locate a predefined number of facilities in order to maximize the number of covered demand points. In a classical sense, MCLP has three main implicit assumptions: all or nothing coverage, individual coverage, and fixed coverage radius. By relaxing these assumptions, three classes of modelling formulations are extended: the gradual cover models, the cooperative cover models, and the variable radius models. In this paper, we develop a special form of MCLP which combines the characteristics of gradual cover models, cooperative cover models, and variable radius models. The proposed problem has many applications such as locating cell phone towers. The model is formulated as a mixed integer non-linear programming (MINLP. In addition, a simulated annealing algorithm is used to solve the resulted problem and the performance of the proposed method is evaluated with a set of randomly generated problems.

  1. Oblique derivative problems for generalized Rassias equations of mixed type with several characteristic boundaries

    Directory of Open Access Journals (Sweden)

    Guo Chun Wen

    2009-05-01

    Full Text Available This article concerns the oblique derivative problems for second-order quasilinear degenerate equations of mixed type with several characteristic boundaries, which include the Tricomi problem as a special case. First we formulate the problem and obtain estimates of its solutions, then we show the existence of solutions by the successive iterations and the Leray-Schauder theorem. We use a complex analytic method: elliptic complex functions are used in the elliptic domain, and hyperbolic complex functions in the hyperbolic domain, such that second-order equations of mixed type with degenerate curve are reduced to the first order mixed complex equations with singular coefficients. An application of the complex analytic method, solves (1.1 below with $m=n=1$, $a=b=0$, which was posed as an open problem by Rassias.

  2. A Mixed Enthalpy-Temperature Finite Element Method For Generalized Phase-Change Problems

    DEFF Research Database (Denmark)

    krabbenhøft, Kristian; Damkilde, Lars

    2003-01-01

    In a large number of problems of engineering interest the transition of the material from one phase to another is of vital importance in describing the overall physical behaviour. Common applications include metal casting, freezing and thawing of foodstuffs and other biological materials, ground ...... freezing and solar energy storage. The phase-change problem is characterized by an abrupt change in enthalpy per unit temperature in a narrow temperature range around the freezing point....

  3. The Association between Sleep Problems and Psychotic Symptoms in the General Population: A Global Perspective.

    Science.gov (United States)

    Koyanagi, Ai; Stickley, Andrew

    2015-12-01

    To assess the prevalence of sleep problems and their association with psychotic symptoms using a global database. Community-based cross-sectional study. Data were analyzed from the World Health Organization's World Health Survey (WHS), a population-based survey conducted in 70 countries between 2002 and 2004. 261,547 individuals aged ≥ 18 years from 56 countries. N/A. The presence of psychotic symptoms in the past 12 months was established using 4 questions pertaining to positive symptoms from the psychosis screening module of the Composite International Diagnostic Interview. Sleep problems referred to severe or extreme sleep problems in the past 30 days. Multivariable logistic regression was used to estimate the associations. The overall prevalence of sleep problems was 7.6% and ranged from 1.6% (China) to 18.6% (Morocco). Sleep problems were associated with significantly higher odds for at least one psychotic symptom in the vast majority of countries. In the pooled sample, after adjusting for demographic factors, alcohol consumption, smoking, and chronic medical conditions, having sleep problems resulted in an odds ratio (OR) for at least one psychotic symptom of 2.41 (95% confidence interval [CI] 2.18-2.65). This OR was 1.59 (1.40-1.81) when further adjusted for anxiety and depression. A strong association between sleep problems and psychotic symptoms was observed globally. These results have clinical implications and serve as a basis for future studies to elucidate the causal association between psychotic symptoms and sleep problems. © 2015 Associated Professional Sleep Societies, LLC.

  4. A Mixed Enthalpy-Temperature Finite Element Method For Generalized Phase-Change Problems

    DEFF Research Database (Denmark)

    krabbenhøft, Kristian; Damkilde, Lars

    2003-01-01

    In a large number of problems of engineering interest the transition of the material from one phase to another is of vital importance in describing the overall physical behaviour. Common applications include metal casting, freezing and thawing of foodstuffs and other biological materials, ground...... freezing and solar energy storage. The phase-change problem is characterized by an abrupt change in enthalpy per unit temperature in a narrow temperature range around the freezing point....

  5. Extension problem for generalized multi-monogenic functions in Clifford analysis

    International Nuclear Information System (INIS)

    Tran Quyet Thang.

    1992-10-01

    The main purpose of this paper is to extend some properties of multi-monogenic functions, which is a generalization of monogenic functions in higher dimensions, for a class of functions satisfying Vekua-type generalized Cauchy-Riemann equations in Clifford Analysis. It is proved that the Hartogs theorem is valid for these functions. (author). 7 refs

  6. Twenty Years of General Education in China: Progress, Problems, and Solutions

    Science.gov (United States)

    Wang, Hongcai; Xie, Debo

    2018-01-01

    General education is a subject with rich contents and that is highly contested in the field of higher education studies. It has been highly praised for its core concepts such as broad educational targets, liberating educational objectives, and balanced educational content. Looking back at the course of general education in China over the past 20…

  7. The Role of General Physical Education in Solution of Health Problem of Russia’s Population

    Directory of Open Access Journals (Sweden)

    V.P. Lykyanenko

    2012-06-01

    Full Text Available The educational concept, worked out by the author rests on the ideas of fundamentalization of school physical educational process, basing on the unique general educational potential of this subject, acquiring the character of fundamental, backbone principle of general secondary education, reflecting its essence, goal and objectives in modern society with its core.

  8. Effort-Reward Imbalance and Mental Health Problems in 1074 German Teachers, Compared with Those in the General Population.

    Science.gov (United States)

    Hinz, Andreas; Zenger, Markus; Brähler, Elmar; Spitzer, Silvia; Scheuch, Klaus; Seibt, Reingard

    2016-08-01

    High degrees of premature retirement among teachers warrant investigating the occupational burden and the mental health status of this profession. A sample of 1074 German teachers participated in this study. Two samples of the general population (N = 824 and N = 792) were used as comparison groups. Work distress was assessed with the Effort-Reward-Imbalance questionnaire, and mental health problems were measured with the General Health Questionnaire (GHQ-12). Teachers reported more effort-reward imbalance (M = 0.64) compared with the general population (M = 0.57), and they perceived more mental health problems (GHQ: M = 12.1) than the comparison group (M = 9.5). School type was not associated with work stress and mental health. Teachers with leading functions perceived high degrees of effort and reward, resulting in a moderate effort-reward ratio and no heightened mental health problems. Teachers working full time reported more effort than teachers working part time, but the reward mean values of both groups were similar. This results in a somewhat unfavourable effort-reward ratio of teachers working full time. Moreover, teachers working full time reported more mental health problems. The results support the appropriateness of the effort-reward conception, applied to the profession of teachers. The higher degree of effort-reward imbalance and the level of mental health problems warrant preventive measures. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  9. On the Existence and Uniqueness of Rv-Generalized Solution for Dirichlet Problem with Singularity on All Boundary

    Directory of Open Access Journals (Sweden)

    V. Rukavishnikov

    2014-01-01

    Full Text Available The existence and uniqueness of the Rv-generalized solution for the first boundary value problem and a second order elliptic equation with coordinated and uncoordinated degeneracy of input data and with strong singularity solution on all boundary of a two-dimensional domain are established.

  10. The Views of the Teachers Related to the Problems the Nursery Class Teachers Encounter in Personnel Services and General Services

    Science.gov (United States)

    Ertör, Eren; Akan, Durdagi

    2016-01-01

    In this study, it was aimed to analyze the problems that the nursery school teachers, who worked in primary schools of Ministry of National Education in Agri city center in 2014-2015 academic years, experience in personnel services and general services according to the views of the teachers. In the direction of this purpose, phenomenology design,…

  11. Total variation regularization of the 3-D gravity inverse problem using a randomized generalized singular value decomposition

    Science.gov (United States)

    Vatankhah, Saeed; Renaut, Rosemary A.; Ardestani, Vahid E.

    2018-04-01

    We present a fast algorithm for the total variation regularization of the 3-D gravity inverse problem. Through imposition of the total variation regularization, subsurface structures presenting with sharp discontinuities are preserved better than when using a conventional minimum-structure inversion. The associated problem formulation for the regularization is nonlinear but can be solved using an iteratively reweighted least-squares algorithm. For small-scale problems the regularized least-squares problem at each iteration can be solved using the generalized singular value decomposition. This is not feasible for large-scale, or even moderate-scale, problems. Instead we introduce the use of a randomized generalized singular value decomposition in order to reduce the dimensions of the problem and provide an effective and efficient solution technique. For further efficiency an alternating direction algorithm is used to implement the total variation weighting operator within the iteratively reweighted least-squares algorithm. Presented results for synthetic examples demonstrate that the novel randomized decomposition provides good accuracy for reduced computational and memory demands as compared to use of classical approaches.

  12. Problems which are well posed in a generalized sense with applications to the Einstein equations

    International Nuclear Information System (INIS)

    Kreiss, H-O; Winicour, J

    2006-01-01

    In the harmonic description of general relativity, the principal part of the Einstein equations reduces to a constrained system of ten curved space wave equations for the components of the spacetime metric. We use the pseudo- differential theory of systems which are strongly well posed in the generalized sense to establish the well posedness of constraint-preserving boundary conditions for this system when treated in a second-order differential form. The boundary conditions are of a generalized Sommerfeld type that is benevolent for numerical calculation

  13. Generalized Airy functions for use in one-dimensional quantum mechanical problems

    Science.gov (United States)

    Eaves, J. O.

    1972-01-01

    The solution of the one dimensional, time independent, Schroedinger equation in which the energy minus the potential varies as the nth power of the distance is obtained from proper linear combinations of Bessel functions. The linear combinations called generalized Airy functions, reduce to the usual Airy functions Ai(x) and Bi(x) when n equals 1 and have the same type of simple asymptotic behavior. Expressions for the generalized Airy functions which can be evaluated by the method of generalized Gaussian quadrature are obtained.

  14. Self-adjoint extensions and spectral analysis in the generalized Kratzer problem

    International Nuclear Information System (INIS)

    Baldiotti, M C; Gitman, D M; Tyutin, I V; Voronov, B L

    2011-01-01

    We present a mathematically rigorous quantum-mechanical treatment of a one-dimensional non-relativistic motion of a particle in the potential field V(x)=g 1 x -1 +g 2 x -2 , x is an element of R + = [0, ∞). For g 2 >0 and g 1 K (x) and is usually used to describe molecular energy and structure, interactions between different molecules and interactions between non-bonded atoms. We construct all self-adjoint Schroedinger operators with the potential V(x) and represent rigorous solutions of the corresponding spectral problems. Solving the first part of the problem, we use a method of specifying self-adjoint extensions by (asymptotic) self-adjoint boundary conditions. Solving spectral problems, we follow Krein's method of guiding functionals. This work is a continuation of our previous works devoted to the Coulomb, Calogero and Aharonov-Bohm potentials.

  15. SUSY shape-invariant Hamiltonians for the generalized dirac-coulomb problem

    International Nuclear Information System (INIS)

    Rodrigues, R. de Lima; Vaidya, Arvind Narayan

    2007-02-01

    A spin 1/2 relativistic particle described by a general potential in terms of the sum of the Coulomb potential with a Lorentz scalar potential is investigated via supersymmetry in quantum mechanics. (author)

  16. A generalization of Schauder's theorem and its application to Cauchy-Kovalevskaya problem

    Directory of Open Access Journals (Sweden)

    Oleg Zubelevich

    2003-05-01

    Full Text Available We extend the classical majorant functions method to a PDE system which right hand side is a mapping of one functional space to another. This extension is based on some generalization of the Schauder fixed point theorem.

  17. Estimates for a general fractional relaxation equation and application to an inverse source problem

    OpenAIRE

    Bazhlekova, Emilia

    2018-01-01

    A general fractional relaxation equation is considered with a convolutional derivative in time introduced by A. Kochubei (Integr. Equ. Oper. Theory 71 (2011), 583-600). This equation generalizes the single-term, multi-term and distributed-order fractional relaxation equations. The fundamental and the impulse-response solutions are studied in detail. Properties such as analyticity and subordination identities are established and employed in the proof of an upper and a lower bound. The obtained...

  18. On the general principles and problems of realization of gasers (gamma-lasers)

    International Nuclear Information System (INIS)

    Gol'danskij, V.I.; Kagan, Yu.

    1975-01-01

    An attempt is presented to formulate main principles behind induced generation of gamma quanta and to prove that the requirements thereof are consistent with actual physical parameters. The problems are discussed of constructing the so-called gasers, i.e. lasers operated by gamma transitions, and of their possible applications. (L.O.)

  19. The H2 control problem: a general transfer-function solution

    Czech Academy of Sciences Publication Activity Database

    Kučera, Vladimír

    2007-01-01

    Roč. 80, č. 5 (2007), s. 800-815 ISSN 0020-7179 Institutional research plan: CEZ:AV0Z10750506 Keywords : linear system * polynomial design methods * H_2 control problem Subject RIV: BC - Control Systems Theory Impact factor: 0.861, year: 2007

  20. Psychological and social problems in primary care patients - general practitioners' assessment and classification

    DEFF Research Database (Denmark)

    Rosendal, Marianne; Vedsted, Peter; Christensen, Kaj Sparle

    2013-01-01

    I almen praksis får 11 % af patienterne en diagnose, der vedrører psykisk sygdom. Heraf har halvdelen en depression eller en belastningstilstand. Kun 18 af de 43 tilgængelige diagnoser i ICPC anvendes regelmæssigt. Sociale problemer angives sjældent som primær problemstilling (0,5 %). Uafhængigt ...

  1. Foot problems in children presented to the general practitioner: a comparison between 1987 and 2001.

    NARCIS (Netherlands)

    Krul, M.; Wouden, J.C. van der; Schellevis, F.G.; Suijlekom-Smit, L.W.A. van; Koes, B.W.

    2009-01-01

    BACKGROUND: In recent decades, studies on the management of common foot problems in children have suggested that in many cases, there is no indication for treatment. It is not known whether these studies have changed daily practice. OBJECTIVE: Our aim was to establish and compare incidence and

  2. A note on hierarchical hubbing for a generalization of the VPN problem

    NARCIS (Netherlands)

    N.K. Olver (Neil)

    2014-01-01

    htmlabstractRobust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. The notion of "hierarchical hubbing" was introduced (in the narrow context of a specific robust network design question), by Olver and Shepherd

  3. A note on hierarchical hubbing for a generalization of the VPN problem

    NARCIS (Netherlands)

    N.K. Olver (Neil)

    2016-01-01

    textabstractRobust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. In this context, Fréchette et al. (2013) recently explored hierarchical hubbing: a routing strategy involving a multiplicity of "hubs" connected to

  4. A note on hierarchical hubbing for a generalization of the VPN problem

    NARCIS (Netherlands)

    Olver, N.K.

    2014-01-01

    Robust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. The notion of "hierarchical hubbing" was introduced (in the narrow context of a specific robust network design question), by Olver and Shepherd [2010].

  5. A note on hierarchical hubbing for a generalization of the VPN problem

    NARCIS (Netherlands)

    Olver, Neil

    2016-01-01

    Robust network design refers to a class of optimization problems that occur when designing networks to efficiently handle variable demands. In this context, Fréchette et al. (2013) recently explored hierarchical hubbing: a routing strategy involving a multiplicity of "hubs" connected to terminals

  6. And that is Where the Fun Ends - General Practitioners' Conceptualisation of the Line Between Recreational and Problem Gambling

    Directory of Open Access Journals (Sweden)

    Dieter Egerer Michael

    2015-03-01

    Full Text Available AIMS - Problem gambling is normally identified by fixed criteria of harm adapted from those of substance abuse and by focusing on the individual gambler. However, rigid definitions neglect institutional variations of gambling practices within different legislative configurations. This study proposes analysing the line between recreational and problem gambling by focusing on gambling behaviour and looking at the corruption of the defining factors of play (Cail-lois, 1958 in three different institutional contexts. DESIGN - A stimulated focus-group method (Reception Analytical Group Interview was applied to seven groups of Finnish and French general practitioners each and three groups of German ones to study the variations of conceptualising the defining factors of play as introduced by Caillois. RESULTS - Corruption of play was distinguished by participants from all three countries as the dividing line between recreational and problem gambling, but cultural variations were found: the French and German GPs emphasised the loss of the exceptionality of gambling, whereas the Finnish GPs highlighted the invasion of the home by online gambling. Furthermore, the Finnish and German participants were more concerned about the use of gambling as an emotional regulator, while French GPs echoed the French medical model in discussing the adrenaline rush of problem gamblers. CONCLUSIONS - Caillois' defining factors of play can be used to distinguish recreational from problem gambling and to offer a more encompassing definition of problem gambling. The perception of the line between recreational and problem gambling also seems to depend on the institutional and cultural context.

  7. How do general practitioners experience providing care to refugees with mental health problems? A qualitative study from Denmark.

    Science.gov (United States)

    Jensen, Natasja Koitzsch; Norredam, Marie; Priebe, Stefan; Krasnik, Allan

    2013-01-28

    Refugees are a particularly vulnerable group in relation to the development of mental illness and many may have been subjected to torture or other traumatic experiences. General practitioners are gatekeepers for access to several parts of the psychiatric system and knowledge of their patients' refugee background is crucial to secure adequate care. The aim of this study is to investigate how general practitioners experience providing care to refugees with mental health problems. The study was conducted as part of an EU project on European Best Practices in Access, Quality and Appropriateness of Health Services for Immigrants in Europe (EUGATE). Semi-structured interviews were carried out with nine general practitioners in the vicinity of Copenhagen purposively selected from areas with a high proportion of immigrants. The analysis of the interviews is inspired by qualitative content analysis. One of the main themes identified in the analysis is communication. This includes the use of professional interpreters and that communication entails more than sharing a common language. Quality of care is another theme that emerges and includes awareness of possible trauma history, limited possibilities for refugees to participate in certain treatments due to language barriers and feelings of hopelessness in the general practitioners. The general practitioners may also choose different referral pathways for refugees and they report that their patients lack understanding regarding the differences between psychological problems and physical symptoms. General practitioners experience that providing care to refugees differs from providing care for patients from the majority population. The different strategies employed by the general practitioners in the health care treatment of refugees may be the result of the great diversity in the organisation of general practice in Denmark and the lack of a national strategy in the health care management of refugees. The findings from this

  8. Common mental health problems in immigrants and refugees: general approach in primary care

    Science.gov (United States)

    Kirmayer, Laurence J.; Narasiah, Lavanya; Munoz, Marie; Rashid, Meb; Ryder, Andrew G.; Guzder, Jaswant; Hassan, Ghayda; Rousseau, Cécile; Pottie, Kevin

    2011-01-01

    Background: Recognizing and appropriately treating mental health problems among new immigrants and refugees in primary care poses a challenge because of differences in language and culture and because of specific stressors associated with migration and resettlement. We aimed to identify risk factors and strategies in the approach to mental health assessment and to prevention and treatment of common mental health problems for immigrants in primary care. Methods: We searched and compiled literature on prevalence and risk factors for common mental health problems related to migration, the effect of cultural influences on health and illness, and clinical strategies to improve mental health care for immigrants and refugees. Publications were selected on the basis of relevance, use of recent data and quality in consultation with experts in immigrant and refugee mental health. Results: The migration trajectory can be divided into three components: premigration, migration and postmigration resettlement. Each phase is associated with specific risks and exposures. The prevalence of specific types of mental health problems is influenced by the nature of the migration experience, in terms of adversity experienced before, during and after resettlement. Specific challenges in migrant mental health include communication difficulties because of language and cultural differences; the effect of cultural shaping of symptoms and illness behaviour on diagnosis, coping and treatment; differences in family structure and process affecting adaptation, acculturation and intergenerational conflict; and aspects of acceptance by the receiving society that affect employment, social status and integration. These issues can be addressed through specific inquiry, the use of trained interpreters and culture brokers, meetings with families, and consultation with community organizations. Interpretation: Systematic inquiry into patients’ migration trajectory and subsequent follow-up on culturally

  9. Common mental health problems in immigrants and refugees: general approach in primary care.

    Science.gov (United States)

    Kirmayer, Laurence J; Narasiah, Lavanya; Munoz, Marie; Rashid, Meb; Ryder, Andrew G; Guzder, Jaswant; Hassan, Ghayda; Rousseau, Cécile; Pottie, Kevin

    2011-09-06

    Recognizing and appropriately treating mental health problems among new immigrants and refugees in primary care poses a challenge because of differences in language and culture and because of specific stressors associated with migration and resettlement. We aimed to identify risk factors and strategies in the approach to mental health assessment and to prevention and treatment of common mental health problems for immigrants in primary care. We searched and compiled literature on prevalence and risk factors for common mental health problems related to migration, the effect of cultural influences on health and illness, and clinical strategies to improve mental health care for immigrants and refugees. Publications were selected on the basis of relevance, use of recent data and quality in consultation with experts in immigrant and refugee mental health. The migration trajectory can be divided into three components: premigration, migration and postmigration resettlement. Each phase is associated with specific risks and exposures. The prevalence of specific types of mental health problems is influenced by the nature of the migration experience, in terms of adversity experienced before, during and after resettlement. Specific challenges in migrant mental health include communication difficulties because of language and cultural differences; the effect of cultural shaping of symptoms and illness behaviour on diagnosis, coping and treatment; differences in family structure and process affecting adaptation, acculturation and intergenerational conflict; and aspects of acceptance by the receiving society that affect employment, social status and integration. These issues can be addressed through specific inquiry, the use of trained interpreters and culture brokers, meetings with families, and consultation with community organizations. Systematic inquiry into patients' migration trajectory and subsequent follow-up on culturally appropriate indicators of social, vocational and

  10. Level of satisfaction of older persons with their general practitioner and practice: role of complexity of health problems.

    Science.gov (United States)

    Poot, Antonius J; den Elzen, Wendy P J; Blom, Jeanet W; Gussekloo, Jacobijn

    2014-01-01

    Satisfaction is widely used to evaluate and direct delivery of medical care; a complicated relationship exists between patient satisfaction, morbidity and age. This study investigates the relationships between complexity of health problems and level of patient satisfaction of older persons with their general practitioner (GP) and practice. This study is embedded in the ISCOPE (Integrated Systematic Care for Older Persons) study. Enlisted patients aged ≥75 years from 59 practices received a written questionnaire to screen for complex health problems (somatic, functional, psychological and social). For 2664 randomly chosen respondents (median age 82 years; 68% female) information was collected on level of satisfaction (satisfied, neutral, dissatisfied) with their GP and general practice, and demographic and clinical characteristics including complexity of health problems. Of all participants, 4% was dissatisfied with their GP care, 59% neutral and 37% satisfied. Between these three categories no differences were observed in age, gender, country of birth or education level. The percentage of participants dissatisfied with their GP care increased from 0.4% in those with 0 problem domains to 8% in those with 4 domains, i.e. having complex health problems (ppatient characteristic influencing the perception of care, or whether the care is unable to handle the demands of these patients. Prospective studies are needed to investigate the causal associations between care organization, patient characteristics, indicators of quality, and patient perceptions.

  11. Analytic theory of curvature effects for wave problems with general boundary conditions

    DEFF Research Database (Denmark)

    Willatzen, Morten; Gravesen, Jens; Voon, L. C. Lew Yan

    2010-01-01

    A formalism based on a combination of differential geometry and perturbation theory is used to obtain analytic expressions for confined eigenmode changes due to general curvature effects. In cases of circular-shaped and helix-shaped structures, where alternative analytic solutions can be found......, the perturbative solution is shown to yield the same result. The present technique allows the generalization of earlier results to arbitrary boundary conditions. The power of the method is illustrated using examples based on Maxwell’s and Schrödinger’s equations for applications in photonics and nanoelectronics....

  12. General Disinfection in Medical and Dental Hospitals, Selection of Disinfectant Type and Problems Encountered

    OpenAIRE

    Akça, Gülin

    2015-01-01

    Hospitals are the places where, either the patients or other health workers can encounter with dangerous problem of several bacterial, fungal, viral, parasitic infectious agents, especially the emerging and life threatening ones such as, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus faecalis (VRE), Stenotrophomonas sp., and multi drug resistant Acinetobacter sp., Pseudomonas sp.. The reasons of these resistant microorganisms that can threaten the life o...

  13. Legendre condition and the stabilization problem for classical soliton solutions in generalized Skyrme models

    International Nuclear Information System (INIS)

    Kiknadze, N.A.; Khelashvili, A.A.

    1990-01-01

    The problem on stability of classical soliton solutions is studied from the unique point of view: the Legendre condition - necessary condition of existence of weak local minimum for energy functional (term soliton is used here in the wide sense) is used. Limits to parameters of the model Lagrangians are obtained; it is shown that there is no soliton stabilization in some of them despite the phenomenological achievements. The Jacoby sufficient condition is discussed

  14. The Neighborhood Covering Heuristic (NCH) Approach for the General Mixed Integer Programming Problem

    Science.gov (United States)

    2004-02-02

    5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Creative Action LLC 680 N. Portage Path Akron, OH 44303; The...University of Akron Department of Theoretical and Applied Mathematics Akron OH 44325-4002 8. PERFORMING ORGANIZATION REPORT NUMBER SF309 9...algorithm is naturally adaptable to a parallel architechture . In particular, under NCH, one could parcel out pieces of the problem to many processors

  15. Cauchy problem with general discontinuous initial data along a smooth curve for 2-d Euler system

    Science.gov (United States)

    Chen, Shuxing; Li, Dening

    2014-09-01

    We study the Cauchy problems for the isentropic 2-d Euler system with discontinuous initial data along a smooth curve. All three singularities are present in the solution: shock wave, rarefaction wave and contact discontinuity. We show that the usual restrictive high order compatibility conditions for the initial data are automatically satisfied. The local existence of piecewise smooth solution containing all three waves is established.

  16. GENERAL: Application of Symplectic Algebraic Dynamics Algorithm to Circular Restricted Three-Body Problem

    Science.gov (United States)

    Lu, Wei-Tao; Zhang, Hua; Wang, Shun-Jin

    2008-07-01

    Symplectic algebraic dynamics algorithm (SADA) for ordinary differential equations is applied to solve numerically the circular restricted three-body problem (CR3BP) in dynamical astronomy for both stable motion and chaotic motion. The result is compared with those of Runge-Kutta algorithm and symplectic algorithm under the fourth order, which shows that SADA has higher accuracy than the others in the long-term calculations of the CR3BP.

  17. DISORDERS OF GASTROINTESTINAL TRACT FUNCTION IN INFANTS: THE PROBLEM AND THE ANALYSIS OF GENERALIZED DATA

    OpenAIRE

    N.I. Ursova

    2009-01-01

    The review analyzes the modern opinion on the problem of functional disorders of gastrointestinal tract, which are peculiar to infants. The peculiarities of nutrition and intestinal microbiocenosis in healthy infants are discussed. Authors observe the ways of its correction and propose the principles of a choice of medications, having proven clinical effectiveness in children on early stages of postnatal development. The advantages of natural smectite dioctaedric (Smecta) in prophylaxis and t...

  18. Self-adjoint extensions and spectral analysis in the generalized Kratzer problem

    Energy Technology Data Exchange (ETDEWEB)

    Baldiotti, M C; Gitman, D M [Institute of Physics, University of Sao Paulo (Brazil); Tyutin, I V; Voronov, B L, E-mail: baldiott@fma.if.usp.br, E-mail: gitman@dfn.if.usp.br, E-mail: tyutin@lpi.ru, E-mail: voronov@lpi.ru [Lebedev Physical Institute, Moscow (Russian Federation)

    2011-06-01

    We present a mathematically rigorous quantum-mechanical treatment of a one-dimensional non-relativistic motion of a particle in the potential field V(x)=g{sub 1}x{sup -1}+g{sub 2}x{sup -2}, x is an element of R{sub +} = [0, {infinity}). For g{sub 2}>0 and g{sub 1}<0, the potential is known as the Kratzer potential V{sub K}(x) and is usually used to describe molecular energy and structure, interactions between different molecules and interactions between non-bonded atoms. We construct all self-adjoint Schroedinger operators with the potential V(x) and represent rigorous solutions of the corresponding spectral problems. Solving the first part of the problem, we use a method of specifying self-adjoint extensions by (asymptotic) self-adjoint boundary conditions. Solving spectral problems, we follow Krein's method of guiding functionals. This work is a continuation of our previous works devoted to the Coulomb, Calogero and Aharonov-Bohm potentials.

  19. General health workers' description of mental health problems and treatment approaches used in Papua New Guinea.

    Science.gov (United States)

    Koka, Betty E; Deane, Frank P; Lyons, Geoffrey Cb; Lambert, Gordon

    2014-11-01

    Papua New Guinea is a developing country with limited resources for specialist mental health services. Little is known about the mental health and treatment services of Papua New Guinea. The aim of this study was to clarify the presenting mental health problems encountered by Papua New Guinean health workers and the common treatment approaches used. A total of 203 Papua New Guinean health workers completed a retrospective quantitative survey about their three most recent mental health patients. The survey asked about presenting symptomatology, diagnoses (including culture-bound diagnoses) and treatment approaches. The major presenting mental health problems for males included schizophrenia, substance use disorder, sorcery and spirit possession. Depression was the most common diagnoses for women, followed by sorcery and somatisation. Over 65% of patients were prescribed psychotropic medication, over 50% received some form of psychological intervention and 28% were receiving traditional treatments. Somatic symptoms are common among both male and female Papua New Guineans; however, males may be more likely to present with psychotic symptoms and females with mood-related problems. Schizophrenia and depression are commonly identified with substance use disorder more problematic among males. Culture-specific explanations and treatment are commonly used. © The Author(s) 2013.

  20. ABAQUS-EPGEN: a general-purpose finite element code. Volume 3. Example problems manual

    International Nuclear Information System (INIS)

    Hibbitt, H.D.; Karlsson, B.I.; Sorensen, E.P.

    1983-03-01

    This volume is the Example and Verification Problems Manual for ABAQUS/EPGEN. Companion volumes are the User's, Theory and Systems Manuals. This volume contains two major parts. The bulk of the manual (Sections 1-8) contains worked examples that are discussed in detail, while Appendix A documents a large set of basic verification cases that provide the fundamental check of the elements in the code. The examples in Sections 1-8 illustrate and verify significant aspects of the program's capability. Most of these problems provide verification, but they have also been chosen to allow discussion of modeling and analysis techniques. Appendix A contains basic verification cases. Each of these cases verifies one element in the program's library. The verification consists of applying all possible load or flux types (including thermal loading of stress elements), and all possible foundation or film/radiation conditions, and checking the resulting force and stress solutions or flux and temperature results. This manual provides program verification. All of the problems described in the manual are run and the results checked, for each release of the program, and these verification results are made available

  1. «CARDIAC PAIN» AS THE PATIENT’S PROBLEM IN GENERAL PRACTICE

    Directory of Open Access Journals (Sweden)

    S.V. Afanasieva

    2008-03-01

    Full Text Available The team of the first medico sanitary aid for population has examined the patients with ‘cardiac pain' (heavy heart in the district of general practitioner. The physical diagnosis, parameters of psychological and social status were determined. The authors developed clinical recommendations to organization of diagnostics and interference.

  2. The Problems and Prospects of General Education in an Information Society

    Science.gov (United States)

    Rusetskii, V. F.

    2014-01-01

    Russian education faces a difficult task in defining what its education system needs to be achieving to maximize its effectiveness in a changing society. Both educational officials and the general public need to be more aware of this challenge and how to deal with it. [This article was translated by Kim Braithwaite.

  3. A Jacobi-Davidson type method for the generalized singular value problem

    NARCIS (Netherlands)

    Hochstenbach, M.E.

    2009-01-01

    We discuss a new method for the iterative computation of some of the generalized singular values and vectors of a large sparse matrix. Our starting point is the augmented matrix formulation of the GSVD. The subspace expansion is performed by (approximately) solving a Jacobi–Davidson type correction

  4. Integral transform method for solving neutron transport problems with general anisotropic scattering in a cylinder of finite height

    International Nuclear Information System (INIS)

    Kumar, V.; Sahni, D.C.

    1983-01-01

    In this paper, the authors present the mathematical techniques that were developed for solving the integral transport equation for the criticality of a homogeneous cylinder of finite height with general anisotropic scattering. They present the integral transport equations for the Fourier transformed spherical harmonic moments of the angular flux. These moments are also represented by a series of products of spherical Bessel functions. The criticality problem is, then, posed by the matrix eigenvalue problem whose eigenvector is composed of the expansion coefficients mentioned above. An methodology of calculating the general matrix element is discussed by using the recursion relations derived in this paper. Finally, for the one-group criticality of finite cylinders, the benchmark results are generated when scattering is linearly anisotropic. Also, these benchmarks are solved and compared with the S/sub N/ method of TWOTRAN

  5. Spa therapy (balneotherapy) relieves mental stress, sleep disorder, and general health problems in sub-healthy people

    Science.gov (United States)

    Yang, Bei; Qin, Qi-zhong; Han, Ling-li; Lin, Jing; Chen, Yu

    2018-02-01

    To investigate the relieving effects of hot spring balneotherapy on mental stress, sleep disorder, general health problems, and women's health problems in sub-healthy people, we recruited 500 volunteers in sub-health in Chongqing, and 362 volunteers completed the project, including 223 in the intervention group and 139 in the control group. The intervention group underwent hot spring balneotherapy for 5 months, while the control group did not. The two groups took questionnaire investigation (general data, mental stress, emotional status, sleep quality, general health problems, as well as some women's health problems) and physical examination (height, weight, waist circumference, blood pressure, blood lipid, blood sugar) 5 months before and after the intervention, respectively. After intervention, sleep disorder (difficulty in falling asleep ( P = 0.017); dreaminess, nightmare suffering, and restless sleep ( P = 0.013); easy awakening ( P = 0.003) and difficulty in falling into sleep again after awakening( P = 0.016); and mental stress ( P = 0.031) and problems of general health (head pain ( P = 0.026), joint pain( P = 0.009), leg or foot cramps ( P = 0.001), blurred vision ( P = 0.009)) were relieved significantly in the intervention group, as compared with the control group. While other indicators (fatigue, eye tiredness, limb numbness, constipation, skin allergy) and women's health problems (breast distending pain; dysmenorrhea, irregular menstruation) were relieved significantly in the self-comparison of the intervention group before and after intervention ( P 0.05). All indications (except bad mood, low mood, and worry or irritability) in the intervention group significantly improved, with effect size from 0.096 to 1.302. Multiple logistic regression analysis showed that the frequency, length, and location of balneotherapy in the intervention group were the factors influencing emotion, sleep, and health condition ( P Physical examination found that waist

  6. Existence of Positive Solutions to Singular -Laplacian General Dirichlet Boundary Value Problems with Sign Changing Nonlinearity

    Directory of Open Access Journals (Sweden)

    Qiying Wei

    2009-01-01

    Full Text Available By using the well-known Schauder fixed point theorem and upper and lower solution method, we present some existence criteria for positive solution of an -point singular -Laplacian dynamic equation on time scales with the sign changing nonlinearity. These results are new even for the corresponding differential (=ℝ and difference equations (=ℤ, as well as in general time scales setting. As an application, an example is given to illustrate the results.

  7. Generalized W1;1-Young Measures and Relaxation of Problems with Linear Growth

    Czech Academy of Sciences Publication Activity Database

    Baia, M.; Krömer, Stefan; Kružík, Martin

    2018-01-01

    Roč. 50, č. 1 (2018), s. 1076-1119 ISSN 0036-1410 R&D Projects: GA ČR GA14-15264S; GA ČR(CZ) GF16-34894L Institutional support: RVO:67985556 Keywords : lower semicontinuity * quasiconvexity * Young measures Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.648, year: 2016 http://library.utia.cas.cz/2018/MTR/kruzik-0487019.pdf

  8. Investigation of the Practical Possibility of Solving Problems on Generalized Cellular Automata Associated with Cryptanalysis by Mean Algebraic Methods

    Directory of Open Access Journals (Sweden)

    P. G. Klyucharev

    2017-01-01

    Full Text Available A number of previous author’s papers proposed methods for constructing various cryptographic algorithms, including block ciphers and cryptographic hash functions, based on generalized cellular automata. This one is aimed at studying a possibility to use the algebraic cryptanalysis methods related to the construction of Gröbner bases for the generalized cellular automata to be applied in cryptography, i.e. this paper studies the possibility for using algebraic cryptanalysis methods to solve the problems of inversion of a generalized cellular automaton and recovering the key of such an automaton.If the cryptographic algorithm is represented as a system of polynomial equations over a certain finite field, then its breach is reduced to solving this system with respect to the key. Although the problem of solving a system of polynomial equations in a finite field is NP-difficult in the general case, the solution of a particular system can have low computational cost.Cryptanalysis based on the construction of a system of polynomial equations that links plain text, cipher-text and key, and its solution by algebraic methods, is usually called algebraic cryptanalysis. Among the main methods to solve systems of polynomial equations are those to construct Gröbner bases.Cryptanalysis of ciphers and hash functions based on generalized cellular automata can be reduced to various problems. We will consider two such problems: the problem of inversion of a generalized cellular automaton, which, in case we know the values of the cells after k iterations, enables us to find the initial values. And the task of recovering the key, which is to find the initial values of the remaining cells, using the cell values after k steps and the initial values of a part of the cells.A computational experiment was carried out to solve the two problems above stated in order to determine the maximum size of a generalized cellular automaton for which the solution of these

  9. Generalized stochastic target problems for pricing and partial hedging under loss constraints - Application in optimal book liquidation

    OpenAIRE

    Bouchard , Bruno; Dang , Ngoc Minh

    2013-01-01

    International audience; We consider a singular with state constraints version of the stochastic target problems studied in Soner and Touzi (2002) and more recently Bouchard, Elie and Touzi (2008), among others. This provides a general framework for the pricing of contingent claims under risk constraints. Our extended version perfectly suits to market models with proportional transaction costs and to order book liquidation issues. Our main result is a PDE characterization of the associated pri...

  10. Two-body problem in general relativity: A heuristic guide for the Einstein-Rosen bridge and EPR paradox

    OpenAIRE

    Weinstein, Galina

    2015-01-01

    Between 1935 and 1936, Einstein was occupied with the Schwarzschild solution and the singularity within it while working in Princeton on the unified field theory and with his assistant Nathan Rosen, on the theory of the Einstein-Rosen bridges. He was also occupied with quantum theory. He believed that quantum theory was an incomplete representation of real things. Together with Rosen and Boris Podolsky he invented the EPR paradox. I demonstrate that the two-body problem in general relativity ...

  11. Solution of a General Linear Complementarity Problem Using Smooth Optimization and Its Application to Bilinear Programming and LCP

    International Nuclear Information System (INIS)

    Fernandes, L.; Friedlander, A.; Guedes, M.; Judice, J.

    2001-01-01

    This paper addresses a General Linear Complementarity Problem (GLCP) that has found applications in global optimization. It is shown that a solution of the GLCP can be computed by finding a stationary point of a differentiable function over a set defined by simple bounds on the variables. The application of this result to the solution of bilinear programs and LCPs is discussed. Some computational evidence of its usefulness is included in the last part of the paper

  12. Existence and Hadamard well-posedness of a system of simultaneous generalized vector quasi-equilibrium problems

    Directory of Open Access Journals (Sweden)

    Wenyan Zhang

    2017-03-01

    Full Text Available Abstract An existence result for the solution set of a system of simultaneous generalized vector quasi-equilibrium problems (for short, (SSGVQEP is obtained, which improves Theorem 3.1 of the work of Ansari et al. (J. Optim. Theory Appl. 127:27-44, 2005. Moreover, a definition of Hadamard-type well-posedness for (SSGVQEP is introduced and sufficient conditions for Hadamard well-posedness of (SSGVQEP are established.

  13. [Differences in risk factors for disease and health problems between monks and the general population in The Netherlands].

    Science.gov (United States)

    van Meel, D; de Vrij, J H; Kunst, A E; Mackenbach, J P

    1992-08-08

    The aim of this study was to determine whether the austerely living Trappist and Benedictine monks have a lower prevalence of a number of risk factors and health problems than the general Dutch population. A written questionnaire was submitted to monks of 7 monasteries. The response was 67 per cent (134 monks). The data were compared with data from the national Health Interview Survey of 1989, which used an almost identical questionnaire. Adjustment was made for differences in age and education. Monks consume less alcohol and tobacco and have a more austere diet. Their average Quetelet index is lower. The prevalence of cardiovascular disease is lower. On the other hand, monks more often report a number of other chronic diseases, physical complaints, and problems with activities of daily life. They more often have contact with general practitioners and with consultants. The lower prevalence of a number of risk factors among monks reflects their austere way of life. It is not certain whether the lower prevalence of cardiovascular diseases can be attributed to this way of life. The fact that, in general, health problems are more prevalent among monks suggests that changes in lifestyle do not necessarily lead to compression of morbidity.

  14. Theoretical stability in coefficient inverse problems for general hyperbolic equations with numerical reconstruction

    Science.gov (United States)

    Yu, Jie; Liu, Yikan; Yamamoto, Masahiro

    2018-04-01

    In this article, we investigate the determination of the spatial component in the time-dependent second order coefficient of a hyperbolic equation from both theoretical and numerical aspects. By the Carleman estimates for general hyperbolic operators and an auxiliary Carleman estimate, we establish local Hölder stability with either partial boundary or interior measurements under certain geometrical conditions. For numerical reconstruction, we minimize a Tikhonov functional which penalizes the gradient of the unknown function. Based on the resulting variational equation, we design an iteration method which is updated by solving a Poisson equation at each step. One-dimensional prototype examples illustrate the numerical performance of the proposed iteration.

  15. Periodicity computation of generalized mathematical biology problems involving delay differential equations.

    Science.gov (United States)

    Jasim Mohammed, M; Ibrahim, Rabha W; Ahmad, M Z

    2017-03-01

    In this paper, we consider a low initial population model. Our aim is to study the periodicity computation of this model by using neutral differential equations, which are recognized in various studies including biology. We generalize the neutral Rayleigh equation for the third-order by exploiting the model of fractional calculus, in particular the Riemann-Liouville differential operator. We establish the existence and uniqueness of a periodic computational outcome. The technique depends on the continuation theorem of the coincidence degree theory. Besides, an example is presented to demonstrate the finding.

  16. Relativistic two-fermion problem with the most general electric and magnetic potentials

    International Nuclear Information System (INIS)

    Yilmazer, A.U.

    1986-01-01

    The energy equation of two spin-1/2 particles interacting with their charges and anomalous magnetic moments is examined. Starting with the most general Hamiltonian already obtained by other authors, the relevant wave equation has been written in terms of the generators of the de Sitter group. The radial equations for four different two-fermion systems are derived and the positronium case is studied in detail. Their bound state solutions are discussed and the similarity to the sixteen radial equations arrived at by other authors in completely different manner is pointed out. (author)

  17. Generalized permutation symmetry and the flavour problem in SU(2)sub(L)xU(1)

    International Nuclear Information System (INIS)

    Ecker, G.

    1984-01-01

    A generalized permutation group is introduced as a possible horizontal symmetry for SU(2)sub(L)xU(1) gauge theories. It leads to the unique two generation quark mass matrices with a correct prediction for the Cabibbo angle. For three generations the model exhibits spontaneous CP violation, correlates the Kobayashi-Maskawa mixing parameters s 1 and s 3 and predicts an upper bound for the running top quark mass of approximately 45 GeV. The hierarchy of generations is due to a hierarchy of vacuum expectation values rather than of Yukawa coupling constants. (orig.)

  18. The generalized PN synthetic acceleration method for linear transport problems with highly anisotropic scattering

    International Nuclear Information System (INIS)

    Khattab, K.M.

    1998-01-01

    The diffusion synthetic acceleration (DSA) method has been known to be an effective tool for accelerating the iterative solution of transport equations with isotopic or mildly anisotropic scattering. However, the DSA method is not effective for transport equations that have strongly anisotropic scattering. A generalization of the modified DSA (MDSA) methods is proposed. This method converges (Clock time) faster than the MDSA method. It is developed, the results of a Fourier analysis that theoretically predicts its efficiency are described, and numerical results that verify the theoretical prediction are presented. (author). 9 refs., 2 tabs., 5 figs

  19. The generalized PN synthetic acceleration method for linear transport problems with highly anisotropic scattering

    International Nuclear Information System (INIS)

    Khattab, K.M.

    1997-01-01

    The diffusion synthetic acceleration (DSA) method has been known to be an effective tool for accelerating the iterative solution of transport equations with isotropic or mildly anisotropic scattering. However, the DSA method is not effective for transport equations that have strongly anisotropic scattering. A generalization of the modified DSA (MDSA) method is proposed that converges (clock time) faster than the MDSA method. This method is developed, the results of a Fourier analysis that theoretically predicts its efficiency are described, and numerical results that verify the theoretical prediction are presented

  20. A chaos-based evolutionary algorithm for general nonlinear programming problems

    International Nuclear Information System (INIS)

    El-Shorbagy, M.A.; Mousa, A.A.; Nasr, S.M.

    2016-01-01

    In this paper we present a chaos-based evolutionary algorithm (EA) for solving nonlinear programming problems named chaotic genetic algorithm (CGA). CGA integrates genetic algorithm (GA) and chaotic local search (CLS) strategy to accelerate the optimum seeking operation and to speed the convergence to the global solution. The integration of global search represented in genetic algorithm and CLS procedures should offer the advantages of both optimization methods while offsetting their disadvantages. By this way, it is intended to enhance the global convergence and to prevent to stick on a local solution. The inherent characteristics of chaos can enhance optimization algorithms by enabling it to escape from local solutions and increase the convergence to reach to the global solution. Twelve chaotic maps have been analyzed in the proposed approach. The simulation results using the set of CEC’2005 show that the application of chaotic mapping may be an effective strategy to improve the performances of EAs.

  1. A Family of Multipoint Flux Mixed Finite Element Methods for Elliptic Problems on General Grids

    KAUST Repository

    Wheeler, Mary F.

    2011-01-01

    In this paper, we discuss a family of multipoint flux mixed finite element (MFMFE) methods on simplicial, quadrilateral, hexahedral, and triangular-prismatic grids. The MFMFE methods are locally conservative with continuous normal fluxes, since they are developed within a variational framework as mixed finite element methods with special approximating spaces and quadrature rules. The latter allows for local flux elimination giving a cell-centered system for the scalar variable. We study two versions of the method: with a symmetric quadrature rule on smooth grids and a non-symmetric quadrature rule on rough grids. Theoretical and numerical results demonstrate first order convergence for problems with full-tensor coefficients. Second order superconvergence is observed on smooth grids. © 2011 Published by Elsevier Ltd.

  2. DISORDERS OF GASTROINTESTINAL TRACT FUNCTION IN INFANTS: THE PROBLEM AND THE ANALYSIS OF GENERALIZED DATA

    Directory of Open Access Journals (Sweden)

    N.I. Ursova

    2009-01-01

    Full Text Available The review analyzes the modern opinion on the problem of functional disorders of gastrointestinal tract, which are peculiar to infants. The peculiarities of nutrition and intestinal microbiocenosis in healthy infants are discussed. Authors observe the ways of its correction and propose the principles of a choice of medications, having proven clinical effectiveness in children on early stages of postnatal development. The advantages of natural smectite dioctaedric (Smecta in prophylaxis and treatment of functional disorders of gastrointestinal system, acute and chronic diseases in children are presented.Key words: children of early age, gastrointestinal tract, function, nutrition, probiotics, smectite.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2009;8(6:48-54

  3. NJOY91, General ENDF/B Processing System for Reactor Design Problems

    International Nuclear Information System (INIS)

    MacFarlane, R.E.; Barrett, R.J.; Muir, D.W.; Boicourt, R.M.

    1997-01-01

    1 - Description of problem or function: The NJOY nuclear data processing system is a comprehensive computer code package for producing pointwise and multigroup neutron, photon, and charged particle cross sections from ENDF/B evaluated nuclear data. NJOY-89 is a substantial upgrade of the previous release. It includes photon production and photon interaction capabilities, heating calculations, covariance processing, and thermal scattering capabilities. It is capable of processing data in ENDF/B-4, ENDF/B-5, and ENDF/B-6 formats for evaluated data (to the extent that the latter have been frozen at the time of this release). NJOY-91.118: This is the last in the NJOY-91 series. It uses the same module structure as the earlier versions and its graphics options depend on DISSPLA. NJOY91.118 includes bug fixes, improvements in several modules, and some new capabilities. Information on the changes is included in the README file. A new test problem was added to test some ENDF/B-6 features, including Reich-Moore resonance reconstruction, energy-angle matrices in GROUPR, and energy-angle distributions in ACER. The 91.118 release is basically configured for UNIX. Short descriptions of the different modules follow: RECONR Reconstructs pointwise (energy-dependent) cross sections from ENDF/B resonance parameters and interpolation schemes. BROADR Doppler broadens and thins pointwise cross sections. UNRESR Computes effective self-shielded pointwise cross sections in the unresolved-resonance region. HEATR Generates pointwise heat production cross sections (KERMA factors) and radiation-damage-energy production cross sections. THERMR Produces incoherent inelastic energy-to-energy matrices for free or bound scatterers, coherent elastic cross sections for hexagonal materials, and incoherent elastic cross sections. GROUPR Generates self-shielded multigroup cross sections, group- to-group neutron scattering matrices, and photon production matrices from pointwise input. GAMINR Calculates

  4. Problems of Economic Grown in Modern Russia: General Characteristics and Regional Aspect

    Directory of Open Access Journals (Sweden)

    Sergey N. Levin

    2016-12-01

    Full Text Available Authors analyze the problem to find the optimal policy options to stimulate economic growth in modern conditions. They point out three possible options for such policy according to the different structural priorities. This point causes the question of the extent to which the proposed policy approaches to stimulate economic growth correspond to real economic trends. The solution of this problem is possible only on the basis of the empirical study analysis results. Also it is necessary to take into account the regional dimension related to the fact that the various sectors of the economy linked to the various regions. According to this fact one may point out Russian regions with the predominance of the mining industry, manufacturing industry and services. Authors exploit panel dataset on 80 Russian regions for the period 2005-2014 to analyze the relationship between annual shares of sectors in output and employment and per capita gross regional growth. Results indicate that regions with a higher share of manufacturing and mining both in terms of output and employment grow slower during the reporting period. The impact of services on growth is somewhat paradoxical: regions with bigger shares of healthcare and education in output growth faster, but a bigger share of this sector in employment, as much as expanding of the labor share of these sectors impede growth. Possible reason for this paradox is that the high proportion of services in the regions-leaders (especially the share of total employment reflects not the degree of their development, but the development of the public sector in relatively poor regions. The results show that neither manufacturing nor mining and services are not the engines of economic growth that can ensure sustainable development of the whole economy. Authors point out that it is necessary to conduct multivariate policies to stimulate economic growth, which is based on the various configurations of developmental actors

  5. The Riemann problem for the relativistic full Euler system with generalized Chaplygin proper energy density-pressure relation

    Science.gov (United States)

    Shao, Zhiqiang

    2018-04-01

    The relativistic full Euler system with generalized Chaplygin proper energy density-pressure relation is studied. The Riemann problem is solved constructively. The delta shock wave arises in the Riemann solutions, provided that the initial data satisfy some certain conditions, although the system is strictly hyperbolic and the first and third characteristic fields are genuinely nonlinear, while the second one is linearly degenerate. There are five kinds of Riemann solutions, in which four only consist of a shock wave and a centered rarefaction wave or two shock waves or two centered rarefaction waves, and a contact discontinuity between the constant states (precisely speaking, the solutions consist in general of three waves), and the other involves delta shocks on which both the rest mass density and the proper energy density simultaneously contain the Dirac delta function. It is quite different from the previous ones on which only one state variable contains the Dirac delta function. The formation mechanism, generalized Rankine-Hugoniot relation and entropy condition are clarified for this type of delta shock wave. Under the generalized Rankine-Hugoniot relation and entropy condition, we establish the existence and uniqueness of solutions involving delta shocks for the Riemann problem.

  6. Open problems and results in the group theoretic approach to quantum gravity via the BMS group and its generalizations

    International Nuclear Information System (INIS)

    Melas, Evangelos

    2011-01-01

    The Bondi-Metzner-Sachs group B is the common asymptotic group of all asymptotically flat (lorentzian) space-times, and is the best candidate for the universal symmetry group of General Relativity. However, in quantum gravity, complexified or euclidean versions of General Relativity are frequently considered. McCarthy has shown that there are forty-two generalizations of B for these versions of the theory and a variety of further ones, either real in any signature, or complex. A firm foundation for quantum gravity can be laid by following through the analogue of Wigner's programme for special relativity with B replacing the Poincare group P. Here the main results which have been obtained so far in this research programme are reported and the more important open problems are stated.

  7. RESEARCH OF PROBLEMS OF DESIGN OF COMPLEX TECHNICAL PROVIDING AND THE GENERALIZED MODEL OF THEIR DECISION

    Directory of Open Access Journals (Sweden)

    A. V. Skrypnikov

    2015-01-01

    Full Text Available Summary. In this work the general ideas of a method of V. I. Skurikhin taking into account the specified features develop and questions of the analysis and synthesis of a complex of technical means, with finishing them to the level suitable for use in engineering practice of design of information management systems are in more detail considered. In work the general system approach to the solution of questions of a choice of technical means of the information management system is created, the general technique of the sys tem analysis and synthesis of a complex of the technical means and its subsystems providing achievement of extreme value of criterion of efficiency of functioning of a technical complex of the information management system is developed. The main attention is paid to the applied party of system researches of complex technical providing, in particular, to definition of criteria of quality of functioning of a technical complex, development of methods of the analysis of information base of the information management system and definition of requirements to technical means, and also methods of structural synthesis of the main subsystems of complex technical providing. Thus, the purpose is research on the basis of system approach of complex technical providing the information management system and development of a number of methods of the analysis and the synthesis of complex technical providing suitable for use in engineering practice of design of systems. The well-known paradox of development of management information consists of that parameters of the system, and consequently, and requirements to the complex hardware, can not be strictly reasonable to development of algorithms and programs, and vice versa. The possible method of overcoming of these difficulties is prognostication of structure and parameters of complex hardware for certain management informations on the early stages of development, with subsequent clarification and

  8. On a first passage problem in general queueing systems with multiple vacations

    Directory of Open Access Journals (Sweden)

    Jewgeni H. Dshalalow

    1992-01-01

    Full Text Available The author studies a generalized single-server queueing system with bulk arrivals and batch service, where the server takes vacations each time the queue level falls below r(≥1 in accordance with the multiple vacation discipline. The input to the system is assumed to be a compound Poisson process modulated by the system and the service is assumed to be state dependent. One of the essential part in the analysis of the system is the employment of new techniques related to the first excess level processes. A preliminary analysis of such processes and recent results of the author on modulated processes enabled the author to obtain all major characteristics for the queueing process explicitly. Various examples and applications are discussed.

  9. Generalized Gibbs distribution and energy localization in the semiclassical FPU problem

    Science.gov (United States)

    Hipolito, Rafael; Danshita, Ippei; Oganesyan, Vadim; Polkovnikov, Anatoli

    2011-03-01

    We investigate dynamics of the weakly interacting quantum mechanical Fermi-Pasta-Ulam (qFPU) model in the semiclassical limit below the stochasticity threshold. Within this limit we find that initial quantum fluctuations lead to the damping of FPU oscillations and relaxation of the system to a slowly evolving steady state with energy localized within few momentum modes. We find that in large systems this state can be described by the generalized Gibbs ensemble (GGE), with the Lagrange multipliers being very weak functions of time. This ensembles gives accurate description of the instantaneous correlation functions, both quadratic and quartic. Based on these results we conjecture that GGE generically appears as a prethermalized state in weakly non-integrable systems.

  10. Progress in Application of Generalized Wigner Distribution to Growth and Other Problems

    Science.gov (United States)

    Einstein, T. L.; Morales-Cifuentes, Josue; Pimpinelli, Alberto; Gonzalez, Diego Luis

    We recap the use of the (single-parameter) Generalized Wigner Distribution (GWD) to analyze capture-zone distributions associated with submonolayer epitaxial growth. We discuss recent applications to physical systems, as well as key simulations. We pay particular attention to how this method compares with other methods to assess the critical nucleus size characterizing growth. The following talk discusses a particular case when special insight is needed to reconcile the various methods. We discuss improvements that can be achieved by going to a 2-parameter fragmentation approach. At a much larger scale we have applied this approach to various distributions in socio-political phenomena (areas of secondary administrative units [e.g., counties] and distributions of subway stations). Work at UMD supported by NSF CHE 13-05892.

  11. NJOY-97, General ENDF/B Processing System for Reactor Design Problems

    International Nuclear Information System (INIS)

    1999-01-01

    larger test-problem suite, a new revision control system, and some changes to the user input. 3 - Restrictions on the complexity of the problem: None noted

  12. Dealing with sickness certification – a survey of problems and strategies among general practitioners and orthopaedic surgeons

    Directory of Open Access Journals (Sweden)

    Nilsson Gunnar

    2007-10-01

    Full Text Available Abstract Background In order to get sickness benefit a sick-listed person need a medical certificate issued by a physician; in Sweden after one week of self-certification. Physicians experience sick-listing tasks as problematic and conflicts may arise when patients regard themselves unable to work due to complaints that are hard to objectively verify for the physician. Most GPs and orthopaedic surgeons (OS deal regularly with sick-listing issues in their daily practice. The aim of this study was to explore perceived problems and coping strategies related to tasks of sickness certification among general practitioners (GP and orthopaedic surgeons (OS. Methods A cross-sectional study about sickness certification in two Swedish counties, with 673 participating GPs and 149 OSs, who answered a comprehensive questionnaire. Frequencies together with crude and adjusted (gender and working years Odds ratios were calculated. Results A majority of the GPs and OSs experienced problems in sickness certification every week. To assess the patient's work ability, to handle situations when they and the patient had different opinions about the need for sickness absence, and to issue prolongation certificates when the previous was issued by another physician were reported as problematic by a majority in both groups. Both GPs and OSs prolonged sickness certifications due to waiting times in health care or at Social Insurance Office (SIO. To handle experienced problems they used different strategies; OSs issued sickness certificates without personal appointment more often than the GPs, who on the other hand reported having contact with SIO more often than the OSs. A higher rate of GPs experienced support from management and had a common strategy for handling sickness certification at the clinic than the OSs. Conclusion Most GPs and OSs handled sickness certification weekly and reported a variety of problems in relation to this task, generally GPs to a higher extent

  13. Patient and population protection in X-ray examinations -a general roentgenological and health problem

    International Nuclear Information System (INIS)

    Khadzhidekov, G.; Dermendzhiev, Kh.

    1975-01-01

    Population exposure in excess of that due to natural radiation background is known to result primarily (to 70-90%) from medical X-rays given in mass screening. Protection of the population is a problem of great concern in present-day radiology and is approached by balancing benefits of diagnostic X-rays against risks presented by the probability of overexposing the patient. An evaluation on such a basis necessitates detailed and accurate information on patient radiation exposure and takes into account factors leading to a population hazard by making assessments in terms of so-called genetically significant doses. Gonad doses have to be carefully analysed, implying a need for studies of various types of X-ray procedures, precautionary measures taken, etc. An important issue in the choice and adoption of an appropriate method for large-scale gonad dose assessments in routine practice. To obtain an estimate of radiation hazard from medical roentgenology in terms of genetically significant doses and identify measures necessary to limit exposure risks, collaborative efforts are needed involving participation of roentgenologists and hygienists, and use of dosimetric, organizational-methodological, and statistical techniques. These efforts should lead to an abrupt reduction in radiation burden to the population from diagnostic X-rays. (author)

  14. General description of preliminary design of an experimental fusion reactor and the future problems

    International Nuclear Information System (INIS)

    Sako, Kiyoshi

    1976-01-01

    Recently, the studies on plasma physics has progressed rapidly, and promising experimental data emerged successively. Especially expectation mounts high that Tokamak will develop into power reactors. In Japan, the construction of large plasma devices such as JT-60 of JAERI is going to start, and after several years, the studies on plasma physics will come to the end of first stage, then the main research and development will be directed to power reactors. The studies on the design of practical fusion reactors have been in progress since 1973 in JAERI, and the preliminary design is being carried out. The purposes of the preliminary design are the clarification of the concept of the experimental reactor and the requirements for the studies on core plasma, the examination of the problems for developing main components and systems of the reactor, and the development of design technology. The experimental reactor is the quasi-steady reactor of 100 MW fusion reaction output, and the conditions set for the design and the basis of their setting are explained. The outline of the design, namely core plasma, blankets, superconductive magnets and the shielding with them, vacuum wall, neutral particle injection heating device, core fuel supply and exhaust system, and others, is described. In case of scale-up the reactor structural material which can withstand neutron damage must be developed. (Kako, I.)

  15. General Relativity without paradigm of space-time covariance, and resolution of the problem of time

    Science.gov (United States)

    Soo, Chopin; Yu, Hoi-Lai

    2014-01-01

    The framework of a theory of gravity from the quantum to the classical regime is presented. The paradigm shift from full space-time covariance to spatial diffeomorphism invariance, together with clean decomposition of the canonical structure, yield transparent physical dynamics and a resolution of the problem of time. The deep divide between quantum mechanics and conventional canonical formulations of quantum gravity is overcome with a Schrödinger equation for quantum geometrodynamics that describes evolution in intrinsic time. Unitary time development with gauge-invariant temporal ordering is also viable. All Kuchar observables become physical; and classical space-time, with direct correlation between its proper times and intrinsic time intervals, emerges from constructive interference. The framework not only yields a physical Hamiltonian for Einstein's theory, but also prompts natural extensions and improvements towards a well behaved quantum theory of gravity. It is a consistent canonical scheme to discuss Horava-Lifshitz theories with intrinsic time evolution, and of the many possible alternatives that respect 3-covariance (rather than the more restrictive 4-covariance of Einstein's theory), Horava's "detailed balance" form of the Hamiltonian constraint is essentially pinned down by this framework. Issues in quantum gravity that depend on radiative corrections and the rigorous definition and regularization of the Hamiltonian operator are not addressed in this work.

  16. How do general practitioners experience providing care to refugees with mental health problems? A qualitative study from Denmark

    Science.gov (United States)

    2013-01-01

    Background Refugees are a particularly vulnerable group in relation to the development of mental illness and many may have been subjected to torture or other traumatic experiences. General practitioners are gatekeepers for access to several parts of the psychiatric system and knowledge of their patients’ refugee background is crucial to secure adequate care. The aim of this study is to investigate how general practitioners experience providing care to refugees with mental health problems. Methods The study was conducted as part of an EU project on European Best Practices in Access, Quality and Appropriateness of Health Services for Immigrants in Europe (EUGATE). Semi-structured interviews were carried out with nine general practitioners in the vicinity of Copenhagen purposively selected from areas with a high proportion of immigrants. The analysis of the interviews is inspired by qualitative content analysis. Results One of the main themes identified in the analysis is communication. This includes the use of professional interpreters and that communication entails more than sharing a common language. Quality of care is another theme that emerges and includes awareness of possible trauma history, limited possibilities for refugees to participate in certain treatments due to language barriers and feelings of hopelessness in the general practitioners. The general practitioners may also choose different referral pathways for refugees and they report that their patients lack understanding regarding the differences between psychological problems and physical symptoms. Conclusion General practitioners experience that providing care to refugees differs from providing care for patients from the majority population. The different strategies employed by the general practitioners in the health care treatment of refugees may be the result of the great diversity in the organisation of general practice in Denmark and the lack of a national strategy in the health care management

  17. How do general practitioners experience providing care to refugees with mental health problems? A qualitative study from Denmark

    Directory of Open Access Journals (Sweden)

    Jensen Natasja Koitzsch

    2013-01-01

    Full Text Available Abstract Background Refugees are a particularly vulnerable group in relation to the development of mental illness and many may have been subjected to torture or other traumatic experiences. General practitioners are gatekeepers for access to several parts of the psychiatric system and knowledge of their patients’ refugee background is crucial to secure adequate care. The aim of this study is to investigate how general practitioners experience providing care to refugees with mental health problems. Methods The study was conducted as part of an EU project on European Best Practices in Access, Quality and Appropriateness of Health Services for Immigrants in Europe (EUGATE. Semi-structured interviews were carried out with nine general practitioners in the vicinity of Copenhagen purposively selected from areas with a high proportion of immigrants. The analysis of the interviews is inspired by qualitative content analysis. Results One of the main themes identified in the analysis is communication. This includes the use of professional interpreters and that communication entails more than sharing a common language. Quality of care is another theme that emerges and includes awareness of possible trauma history, limited possibilities for refugees to participate in certain treatments due to language barriers and feelings of hopelessness in the general practitioners. The general practitioners may also choose different referral pathways for refugees and they report that their patients lack understanding regarding the differences between psychological problems and physical symptoms. Conclusion General practitioners experience that providing care to refugees differs from providing care for patients from the majority population. The different strategies employed by the general practitioners in the health care treatment of refugees may be the result of the great diversity in the organisation of general practice in Denmark and the lack of a national strategy

  18. Model calibration for ice sheets and glaciers dynamics: a general theory of inverse problems in glaciology

    Science.gov (United States)

    Giudici, Mauro; Baratelli, Fulvia; Vassena, Chiara; Cattaneo, Laura

    2014-05-01

    Numerical modelling of the dynamic evolution of ice sheets and glaciers requires the solution of discrete equations which are based on physical principles (e.g. conservation of mass, linear momentum and energy) and phenomenological constitutive laws (e.g. Glen's and Fourier's laws). These equations must be accompanied by information on the forcing term and by initial and boundary conditions (IBC) on ice velocity, stress and temperature; on the other hand the constitutive laws involves many physical parameters, which possibly depend on the ice thermodynamical state. The proper forecast of the dynamics of ice sheets and glaciers (forward problem, FP) requires a precise knowledge of several quantities which appear in the IBCs, in the forcing terms and in the phenomenological laws and which cannot be easily measured at the study scale in the field. Therefore these quantities can be obtained through model calibration, i.e. by the solution of an inverse problem (IP). Roughly speaking, the IP aims at finding the optimal values of the model parameters that yield the best agreement of the model output with the field observations and data. The practical application of IPs is usually formulated as a generalised least squares approach, which can be cast in the framework of Bayesian inference. IPs are well developed in several areas of science and geophysics and several applications were proposed also in glaciology. The objective of this paper is to provide a further step towards a thorough and rigorous theoretical framework in cryospheric studies. Although the IP is often claimed to be ill-posed, this is rigorously true for continuous domain models, whereas for numerical models, which require the solution of algebraic equations, the properties of the IP must be analysed with more care. First of all, it is necessary to clarify the role of experimental and monitoring data to determine the calibration targets and the values of the parameters that can be considered to be fixed

  19. The general problem of the motion of coupled rigid bodies about a fixed point

    CERN Document Server

    Leimanis, Eugene

    1965-01-01

    In the theory of motion of several coupled rigid bodies about a fixed point one can distinguish three basic ramifications. 1. The first, the so-called classical direction of investigations, is concerned with particular cases of integrability ot the equations of motion of a single rigid body about a fixed point,1 and with their geo­ metrical interpretation. This path of thought was predominant until the beginning of the 20th century and its most illustrious represen­ tatives are L. EULER (1707-1783), J L. LAGRANGE (1736-1813), L. POINSOT (1777-1859), S. V. KOVALEVSKAYA (1850-1891), and others. Chapter I of the present monograph intends to reflect this branch of investigations. For collateral reading on the general questions dealt with in this chapter the reader is referred to the following textbooks and reports: A. DOMOGAROV [1J, F. KLEIN and A. SOMMERFELD [11, 1 , 1 J, A. G. 2 3 GREENHILL [10J, A. GRAY [1J, R. GRAMMEL [4 J, E. J. ROUTH [21' 2 , 1 2 31' 32J, J. B. SCARBOROUGH [1J, and V. V. GOLUBEV [1, 2J.

  20. Generalization of the Numerov method for solution of N-d breakup problem in configuration space

    International Nuclear Information System (INIS)

    Suslov, V.M.; Vlahovic, B.

    2004-01-01

    A new computational method for solving the configuration-space Faddeev equations for three-nucleon systems has been developed. This method is based on the spline decomposition in the angular variable and a generalization of the Numerov method for the hyperradius. The s-wave calculations of the inelasticity and phase shift as well as breakup amplitudes for n-d and p-d breakup scatterings for lab energies 14.1 and 42.0 MeV were performed with the Malfliet-Tjon I-III potential. In the case of n-d breakup scattering the results are in good agreement with those of the benchmark solution [J. L. Friar, B. F. Gibson, G. Berthold, W. Gloeckle, Th. Cornelius, H. Witala, J. Haidenbauer, Y. Koike, G. L. Payne, J. A. Tjon, and W. M. Kloet, Phys. Rev. C 42, 1838 (1990); J. L. Friar, G. L. Payne, W. Gloeckle, D. Hueber, and H. Witala, Phys. Rev. C 51, 2356 (1995)]. In the case of p-d quartet breakup scattering disagreement for the inelasticities reaches up to 6% as compared with those of the Pisa group [A. Kievsky, M. Viviani, and S. Rosati, Phys. Rev. C 64, 024002 (2001)]. The calculated p-d amplitudes fulfill the optical theorem with a good precision

  1. Measurement standards and the general problem of reference points in chemical analysis

    International Nuclear Information System (INIS)

    Richter, W.; Dube, G.

    2002-01-01

    Besides the measurement standards available in general metrology in the form of the realisations of the units of measurement, measurement standards of chemical composition are needed for the vast field of chemical measurement (measurements of the chemical composition), because it is the main aim of such measurements to quantify non-isolated substances, often in complicated matrices, to which the 'classical' measurement standards and their lower- level derivatives are not directly applicable. At present, material artefacts as well as standard measurement devices serve as chemical measurement standards. These are measurement standards in the full metrological sense only, however, if they are firmly linked to the SI unit in which the composition represented by the standard is expressed. This requirement has the consequence that only a very restricted number of really reliable chemical measurement standards exist at present. Since it is very difficult and time consuming to increase this number substantially and, on the other hand, reliable reference points are increasingly needed for all kinds of chemical measurements, primary methods of measurement and high-level reference measurements will play an increasingly important role for the establishment of worldwide comparability and hence mutual acceptance of chemical measurement results. (author)

  2. How do NHS general hospitals in England deal with patients with alcohol-related problems? A questionnaire survey.

    Science.gov (United States)

    Owens, Lynn; Gilmore, Ian T; Pirmohamed, Munir

    2005-01-01

    Alcohol-related disease represents a major burden on hospitals. However, it is unclear whether hospitals have developed the necessary expertise and guidelines to deal with this burden. The aim of this survey was to determine what measures general hospital NHS Trusts in England had in place to deal with alcohol-related problems, including the employment of dedicated alcohol specialist nurses. Two postal surveys of all NHS general hospital Trusts in England, the first in 2000 (n = 138; 54% response rate) and the second in 2003 after the publication of the Royal College of Physicians (RCP) report on alcohol in secondary care (n = 164; 75% response rate). Between the two surveys, there was a significant increase (P = 0.005) in the number of dedicated alcohol nurses employed by general hospital trusts; however, the numbers remain low (n = 21). Additionally, the availability of prescribing guidelines for the management of alcohol withdrawal increased significantly (P = 0.0001). The survey indicates that most general hospitals do not have appropriate services in place to deal with such patients. Although there is a need and willingness to develop alcohol services in general hospitals, which is one of the key recommendations of the RCP report, the lack of funding is going to act as a major barrier.

  3. High Order A-stable Continuous General Linear Methods for Solution of Systems of Initial Value Problems in ODEs

    Directory of Open Access Journals (Sweden)

    Dauda GuliburYAKUBU

    2012-12-01

    Full Text Available Accurate solutions to initial value systems of ordinary differential equations may be approximated efficiently by Runge-Kutta methods or linear multistep methods. Each of these has limitations of one sort or another. In this paper we consider, as a middle ground, the derivation of continuous general linear methods for solution of stiff systems of initial value problems in ordinary differential equations. These methods are designed to combine the advantages of both Runge-Kutta and linear multistep methods. Particularly, methods possessing the property of A-stability are identified as promising methods within this large class of general linear methods. We show that the continuous general linear methods are self-starting and have more ability to solve the stiff systems of ordinary differential equations, than the discrete ones. The initial value systems of ordinary differential equations are solved, for instance, without looking for any other method to start the integration process. This desirable feature of the proposed approach leads to obtaining very high accuracy of the solution of the given problem. Illustrative examples are given to demonstrate the novelty and reliability of the methods.

  4. Exercise-induced dyspnea is a problem among the general adolescent population.

    Science.gov (United States)

    Johansson, H; Norlander, K; Hedenström, H; Janson, C; Nordang, L; Nordvall, L; Emtner, M

    2014-06-01

    Respiratory symptoms during exercise are common and might limit adolescents' ability to take part in physical activity. To estimate the prevalence, determinants and consequences of exercise-induced dyspnea (EID) on daily life in a general population of 12-13 year old adolescents. A letter was sent to the parents of all 12-13 year old adolescents in the city of Uppsala (n = 3838). Parents were asked to complete a questionnaire together with their child on EID, asthma and allergy, consequences for daily life (wheeze, day time- and nocturnal dyspnea) and physical activity. The response rate was 60% (n = 2309). Fourteen percent (n = 330) reported EID, i.e. had experienced an attack of shortness of breath that occurred after strenuous activity within the last 12 months. Female gender, ever-asthma and rhinitis were independently associated with an increased risk of EID. Ever-asthma was reported by 14.6% (n = 338), and 5.4% (n = 128) had both EID and ever-asthma. Sixty-one percent (n = 202) of the participants with EID did not have a diagnosis of asthma. In addition to rhinitis, participants with EID reported current wheeze and day-time as well as nocturnal dyspnea more often than the group without EID. No difference was found in the level of physical activity between participants with and without EID. Adolescents with undiagnosed exercise-induced dyspnea have respiratory symptoms and are affected in daily life but have the same level of physical activity as adolescents without exercise-induced respiratory symptoms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Time-Depending Parametric Variational Approach for an Economic General Equilibrium Problem of Pure Exchange with Application

    International Nuclear Information System (INIS)

    Scaramuzzino, F.

    2009-01-01

    This paper considers a qualitative analysis of the solution of a pure exchange general economic equilibrium problem according to two independent parameters. Some recently results obtained by the author in the static and the dynamic case have been collected. Such results have been applied in a particular parametric case: it has been focused the attention on a numerical application for which the existence of the solution of time-depending parametric variational inequality that describes the equilibrium conditions has been proved by means of the direct method. By using MatLab computation after a linear interpolation, the curves of equilibrium have been visualized.

  6. The relationship between stressful working conditions and high alcohol consumption and severe alcohol problems in an urban general population

    DEFF Research Database (Denmark)

    Romelsjö, A; Hasin, D; Hilton, M

    1992-01-01

    The relationship between 15 measures of stressful working conditions and high alcohol consumption (35 g 100% ethanol per day or more for men and 25 g or more for women) was studied, using cross-sectional data from a general population survey of 1344 males and 1494 females; the ages 25-64 years......-adjusted odds ratios, were positive and some were negative when high alcohol consumption was the endpoint, but there was a clear variation by sex and social class. Generally the positive associations were stronger among male non-manual employees. Among males, there was a clear association between stressful...... increased odds ratios were lower when subjects with an alcohol diagnosis at inpatient care during 1980-84 were excluded in the analyses. On the whole, our findings are not conclusive. The strong, but imprecise associations between stressful working conditions and severe alcohol problems, are however...

  7. Reduction by symmetries in singular quantum-mechanical problems: General scheme and application to Aharonov-Bohm model

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A. G., E-mail: smirnov@lpi.ru [I. E. Tamm Theory Department, P. N. Lebedev Physical Institute, Leninsky Prospect 53, Moscow 119991 (Russian Federation)

    2015-12-15

    We develop a general technique for finding self-adjoint extensions of a symmetric operator that respects a given set of its symmetries. Problems of this type naturally arise when considering two- and three-dimensional Schrödinger operators with singular potentials. The approach is based on constructing a unitary transformation diagonalizing the symmetries and reducing the initial operator to the direct integral of a suitable family of partial operators. We prove that symmetry preserving self-adjoint extensions of the initial operator are in a one-to-one correspondence with measurable families of self-adjoint extensions of partial operators obtained by reduction. The general scheme is applied to the three-dimensional Aharonov-Bohm Hamiltonian describing the electron in the magnetic field of an infinitely thin solenoid. We construct all self-adjoint extensions of this Hamiltonian, invariant under translations along the solenoid and rotations around it, and explicitly find their eigenfunction expansions.

  8. How are things adding up? Neural differences between arithmetic operations are due to general problem solving strategies.

    Science.gov (United States)

    Tschentscher, Nadja; Hauk, Olaf

    2014-05-15

    A number of previous studies have interpreted differences in brain activation between arithmetic operation types (e.g. addition and multiplication) as evidence in favor of distinct cortical representations, processes or neural systems. It is still not clear how differences in general task complexity contribute to these neural differences. Here, we used a mental arithmetic paradigm to disentangle brain areas related to general problem solving from those involved in operation type specific processes (addition versus multiplication). We orthogonally varied operation type and complexity. Importantly, complexity was defined not only based on surface criteria (for example number size), but also on the basis of individual participants' strategy ratings, which were validated in a detailed behavioral analysis. We replicated previously reported operation type effects in our analyses based on surface criteria. However, these effects vanished when controlling for individual strategies. Instead, procedural strategies contrasted with memory retrieval reliably activated fronto-parietal and motor regions, while retrieval strategies activated parietal cortices. This challenges views that operation types rely on partially different neural systems, and suggests that previously reported differences between operation types may have emerged due to invalid measures of complexity. We conclude that mental arithmetic is a powerful paradigm to study brain networks of abstract problem solving, as long as individual participants' strategies are taken into account. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Effect of Rotation for Two-Temperature Generalized Thermoelasticity of Two-Dimensional under Thermal Shock Problem

    Directory of Open Access Journals (Sweden)

    Kh. Lotfy

    2013-01-01

    Full Text Available The theory of two-temperature generalized thermoelasticity based on the theory of Youssef is used to solve boundary value problems of two-dimensional half-space. The governing equations are solved using normal mode method under the purview of the Lord-Şhulman (LS and the classical dynamical coupled theory (CD. The general solution obtained is applied to a specific problem of a half-space subjected to one type of heating, the thermal shock type. We study the influence of rotation on the total deformation of thermoelastic half-space and the interaction with each other under the influence of two temperature theory. The material is homogeneous isotropic elastic half-space. The methodology applied here is use of the normal mode analysis techniques that are used to solve the resulting nondimensional coupled field equations for the two theories. Numerical results for the displacement components, force stresses, and temperature distribution are presented graphically and discussed. The conductive temperature, the dynamical temperature, the stress, and the strain distributions are shown graphically with some comparisons.

  10. The "Forgotten" Pseudomomenta and Gauge Changes in Generalized Landau Level Problems: Spatially Nonuniform Magnetic and Temporally Varying Electric Fields

    Science.gov (United States)

    Konstantinou, Georgios; Moulopoulos, Konstantinos

    2017-05-01

    By perceiving gauge invariance as an analytical tool in order to get insight into the states of the "generalized Landau problem" (a charged quantum particle moving inside a magnetic, and possibly electric field), and motivated by an early article that correctly warns against a naive use of gauge transformation procedures in the usual Landau problem (i.e. with the magnetic field being static and uniform), we first show how to bypass the complications pointed out in that article by solving the problem in full generality through gauge transformation techniques in a more appropriate manner. Our solution provides in simple and closed analytical forms all Landau Level-wavefunctions without the need to specify a particular vector potential. This we do by proper handling of the so-called pseudomomentum ěc {{K}} (or of a quantity that we term pseudo-angular momentum L z ), a method that is crucially different from the old warning argument, but also from standard treatments in textbooks and in research literature (where the usual Landau-wavefunctions are employed - labeled with canonical momenta quantum numbers). Most importantly, we go further by showing that a similar procedure can be followed in the more difficult case of spatially-nonuniform magnetic fields: in such case we define ěc {{K}} and L z as plausible generalizations of the previous ordinary case, namely as appropriate line integrals of the inhomogeneous magnetic field - our method providing closed analytical expressions for all stationary state wavefunctions in an easy manner and in a broad set of geometries and gauges. It can thus be viewed as complementary to the few existing works on inhomogeneous magnetic fields, that have so far mostly focused on determining the energy eigenvalues rather than the corresponding eigenkets (on which they have claimed that, even in the simplest cases, it is not possible to obtain in closed form the associated wavefunctions). The analytical forms derived here for these

  11. Axi-symmetric generalized thermoelastic diffusion problem with two-temperature and initial stress under fractional order heat conduction

    International Nuclear Information System (INIS)

    Deswal, Sunita; Kalkal, Kapil Kumar; Sheoran, Sandeep Singh

    2016-01-01

    A mathematical model of fractional order two-temperature generalized thermoelasticity with diffusion and initial stress is proposed to analyze the transient wave phenomenon in an infinite thermoelastic half-space. The governing equations are derived in cylindrical coordinates for a two dimensional axi-symmetric problem. The analytical solution is procured by employing the Laplace and Hankel transforms for time and space variables respectively. The solutions are investigated in detail for a time dependent heat source. By using numerical inversion method of integral transforms, we obtain the solutions for displacement, stress, temperature and diffusion fields in physical domain. Computations are carried out for copper material and displayed graphically. The effect of fractional order parameter, two-temperature parameter, diffusion, initial stress and time on the different thermoelastic and diffusion fields is analyzed on the basis of analytical and numerical results. Some special cases have also been deduced from the present investigation.

  12. Experiences of family carers of older people with mental health problems in the acute general hospital: a qualitative study.

    Science.gov (United States)

    Clissett, Philip; Porock, Davina; Harwood, Rowan H; Gladman, John R F

    2013-12-01

    To explore the experiences of family carers of people with cognitive impairment during admission to hospital. Providing appropriate care in acute hospitals for people with co-morbid cognitive impairment, especially dementia or delirium or both, is challenging to healthcare professionals. One key element is close working with family members. Qualitative interview study. Semi-structured interviews with family carers of 34 older people who had been admitted to a UK general hospital and had co-morbid cognitive impairment. Interviews conducted in 2009 and 2010. Analysis was undertaken using Strauss and Corbin's framework. The findings elaborate a core problem, 'disruption from normal routine' and a core process, 'gaining or giving a sense of control to cope with disruption'. Family carers responded to disruption proactively by trying to make sense of the situation and attempting to gain control for themselves or the patient. They tried to stay informed, communicate with staff about the patient and plan for the future. The interaction of the core problem and the core process resulted in outcomes where family members either valued the support of hospital staff and services or were highly critical of the care provided. Family carers are not passive in the face of the disruption of hospitalization and respond both by trying to involve themselves in the care and support of their relative and by trying to work in partnership with members of staff. Nurses need to foster this relationship conscientiously. © 2013 John Wiley & Sons Ltd.

  13. Emotional intensity reduces later generalized anxiety disorder symptoms when fear of anxiety and negative problem-solving appraisal are low.

    Science.gov (United States)

    Sugiura, Yoshinori; Sugiura, Tomoko

    2015-08-01

    While research based on the emotion dysregulation model indicates a positive relationship between intense emotions and generalized anxiety disorder (GAD) symptoms, emotion-focused intervention involves the use of techniques to enhance emotional experiences, based on the notion that GAD patients are engaging in avoidance strategies. To reveal the conditions under which intense emotions lead to reduced GAD symptoms, we designed a longitudinal study to monitor changes in GAD symptoms among students (N = 129) over 3 months. Our focus was on possible moderators of the effect of emotional intensity. Results indicated that when fear of emotions and negative appraisals about problem solving were low, negative emotional intensity reduced later GAD symptoms. Moreover, under the condition of high responsibility to continue thinking, emotional intensity tended to reduce later GAD symptoms. Results suggest that reduced fear of emotions and reduced negative appraisals about problem solving may enhance the use of emotional processing techniques (e.g., emotional exposure). The interaction between responsibility to continue thinking and emotional intensity requires further examination. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. News from Front (of the Solar System): the problem with Mercury, the Vulcan hypothesis, and General Relativity's first astronomical triumph

    Science.gov (United States)

    Sheehan, William

    2016-01-01

    The discovery of the outer planet Neptune in 1846, based on the calculated position published by Urbain Jean Joseph Le Verrier, has been hailed as the "zenith of Newtonian mechanics." An attempt by Le Verrier to further extend the dominion of Newton's gravitational theory to the innermost known planet of the Solar System, Mercury, seemingly came to grief with the discovery of a small unexplained discrepancy in the precession of the perihelion of Mercury, whose value was later calculated as 43".0 per century. Le Verrier proposed that it could be explained on the basis of Newtonian theory by assuming the existence of an intra-mercurial planet ("Vulcan") or ring of debris. Efforts to confirm this hypothesis, culminating in high drama on the plains of the western United States at the great North American solar eclipse of July 1878, proved futile; by 1908, W. W. Campbell and C.D. Perrine of Lick Observatory, who had carried out exhaustive photographic searches at three eclipses (1901, 1905, and 1908) could declare that Vulcan did not exist. The theoretical problem it was invoked to explain remained until November 1915, when Albert Einstein used the recently discovered generally covariant gravitational equations to put the problem to rest. "Perihelion motions explained quantitatively … you will be astonished," he wrote to his friend Michael Besso.

  15. Preemption versus Entrenchment: Towards a Construction-General Solution to the Problem of the Retreat from Verb Argument Structure Overgeneralization.

    Directory of Open Access Journals (Sweden)

    Ben Ambridge

    Full Text Available Participants aged 5;2-6;8, 9;2-10;6 and 18;1-22;2 (72 at each age rated verb argument structure overgeneralization errors (e.g., *Daddy giggled the baby using a five-point scale. The study was designed to investigate the feasibility of two proposed construction-general solutions to the question of how children retreat from, or avoid, such errors. No support was found for the prediction of the preemption hypothesis that the greater the frequency of the verb in the single most nearly synonymous construction (for this example, the periphrastic causative; e.g., Daddy made the baby giggle, the lower the acceptability of the error. Support was found, however, for the prediction of the entrenchment hypothesis that the greater the overall frequency of the verb, regardless of construction, the lower the acceptability of the error, at least for the two older groups. Thus while entrenchment appears to be a robust solution to the problem of the retreat from error, and one that generalizes across different error types, we did not find evidence that this is the case for preemption. The implication is that the solution to the retreat from error lies not with specialized mechanisms, but rather in a probabilistic process of construction competition.

  16. A non-local theory of generalized entropy solutions of the Cauchy problem for a class of hyperbolic systems of conservation laws

    International Nuclear Information System (INIS)

    Panov, E Yu

    1999-01-01

    We consider a hyperbolic system of conservation laws on the space of symmetric second-order matrices. The right-hand side of this system contains the functional calculus operator f-bar(U) generated in the general case only by a continuous scalar function f(u). For these systems we define and describe the set of singular entropies, introduce the concept of generalized entropy solutions of the corresponding Cauchy problem, and investigate the properties of generalized entropy solutions. We define the class of strong generalized entropy solutions, in which the Cauchy problem has precisely one solution. We suggest a condition on the initial data under which any generalized entropy solution is strong, which implies its uniqueness. Under this condition we establish that the 'vanishing viscosity' method converges. An example shows that in the general case there can be more than one generalized entropy solution

  17. The generalized successive approximation and Padé Approximants method for solving an elasticity problem of based on the elastic ground with variable coefficients

    Directory of Open Access Journals (Sweden)

    Mustafa Bayram

    2017-01-01

    Full Text Available In this study, we have applied a generalized successive numerical technique to solve the elasticity problem of based on the elastic ground with variable coefficient. In the first stage, we have calculated the generalized successive approximation of being given BVP and in the second stage we have transformed it into Padé series. At the end of study a test problem has been given to clarify the method.

  18. IFLA General Conference, 1986. Pre-Conference Seminar on Automated Systems for Access to Multilingual and Multiscript Library materials: Problems and Solutions. Papers.

    Science.gov (United States)

    International Federation of Library Associations and Institutions, The Hague (Netherlands).

    A seminar which considered problems and solutions regarding automated systems for access to multilingual and multiscript library materials was held as a pre-session before the IFLA general conference in 1986. Papers presented include: (1) "Romanized and Transliterated Databases of Asian Language Materials--History, Problems, and…

  19. Discovery of dominant and dormant genes from expression data using a novel generalization of SNR for multi-class problems

    Directory of Open Access Journals (Sweden)

    Chung I-Fang

    2008-10-01

    Full Text Available Abstract Background The Signal-to-Noise-Ratio (SNR is often used for identification of biomarkers for two-class problems and no formal and useful generalization of SNR is available for multiclass problems. We propose innovative generalizations of SNR for multiclass cancer discrimination through introduction of two indices, Gene Dominant Index and Gene Dormant Index (GDIs. These two indices lead to the concepts of dominant and dormant genes with biological significance. We use these indices to develop methodologies for discovery of dominant and dormant biomarkers with interesting biological significance. The dominancy and dormancy of the identified biomarkers and their excellent discriminating power are also demonstrated pictorially using the scatterplot of individual gene and 2-D Sammon's projection of the selected set of genes. Using information from the literature we have shown that the GDI based method can identify dominant and dormant genes that play significant roles in cancer biology. These biomarkers are also used to design diagnostic prediction systems. Results and discussion To evaluate the effectiveness of the GDIs, we have used four multiclass cancer data sets (Small Round Blue Cell Tumors, Leukemia, Central Nervous System Tumors, and Lung Cancer. For each data set we demonstrate that the new indices can find biologically meaningful genes that can act as biomarkers. We then use six machine learning tools, Nearest Neighbor Classifier (NNC, Nearest Mean Classifier (NMC, Support Vector Machine (SVM classifier with linear kernel, and SVM classifier with Gaussian kernel, where both SVMs are used in conjunction with one-vs-all (OVA and one-vs-one (OVO strategies. We found GDIs to be very effective in identifying biomarkers with strong class specific signatures. With all six tools and for all data sets we could achieve better or comparable prediction accuracies usually with fewer marker genes than results reported in the literature using the

  20. On the theory of generalized entropy solutions of the Cauchy problem for a class of non-strictly hyperbolic systems of conservation laws

    International Nuclear Information System (INIS)

    Panov, E Yu

    2000-01-01

    Many-dimensional non-strictly hyperbolic systems of conservation laws with a radially degenerate flux function are considered. For such systems the set of entropies is defined and described, the concept of generalized entropy solution of the Cauchy problem is introduced, and the properties of generalized entropy solutions are studied. The class of strong generalized entropy solutions is distinguished, in which the Cauchy problem in question is uniquely soluble. A condition on the initial data is described that ensures that the generalized entropy solution is strong and therefore unique. Under this condition the convergence of the 'vanishing viscosity' method is established. An example presented in the paper shows that a generalized entropy solution is not necessarily unique in the general case

  1. General problems of metrology and indirect measuring in cardiology: error estimation criteria for indirect measurements of heart cycle phase durations

    Directory of Open Access Journals (Sweden)

    Konstantine K. Mamberger

    2012-11-01

    Full Text Available Aims This paper treats general problems of metrology and indirect measurement methods in cardiology. It is aimed at an identification of error estimation criteria for indirect measurements of heart cycle phase durations. Materials and methods A comparative analysis of an ECG of the ascending aorta recorded with the use of the Hemodynamic Analyzer Cardiocode (HDA lead versus conventional V3, V4, V5, V6 lead system ECGs is presented herein. Criteria for heart cycle phase boundaries are identified with graphic mathematical differentiation. Stroke volumes of blood SV calculated on the basis of the HDA phase duration measurements vs. echocardiography data are compared herein. Results The comparative data obtained in the study show an averaged difference at the level of 1%. An innovative noninvasive measuring technology originally developed by a Russian R & D team offers measuring stroke volume of blood SV with a high accuracy. Conclusion In practice, it is necessary to take into account some possible errors in measurements caused by hardware. Special attention should be paid to systematic errors.

  2. Problem gambling: patients affected by their own or another's gambling may approve of help from general practitioners.

    Science.gov (United States)

    Sullivan, Sean; McCormick, Ross; Lamont, Michael; Penfold, Alison

    2007-06-29

    To identify the health effects, including depression, on problem gambling patients and family members, and their perception of their GP as a help provider for problem gambling. 1580 patients from practices in Auckland, Taranaki, and Rotorua completed an anonymous questionnaire containing brief screens for problem gambling, effects on family of gambling, and depression. Patients were asked to assess their GP as a help provider for problem gambling. 7.5% of patients were positive for problem gambling, ranging from 3% of NZ European patients to 24% of Pacific patients; 18% of patients were affected by another's gambling. Less than one in four problem gambling patients, and one in three family positives, did not perceive their GP as a suitable help provider for problem gambling issues. Problem gambling patients were more likely than other patients to approve their GP as a help-provider. Patients affected by problem gambling were more depressed than other patients. No other disease indicators were found. Patients over 54 years are less likely than others to be problem gamblers. Problem gambling is associated with depression in patients. GPs are an important complementary resource for brief interventions for gambling problems, and for some possibly a more acceptable alternative than attending specialist problem gambling treatment providers.

  3. The ESPAT tool: a general-purpose DSS shell for solving stochastic optimization problems in complex river-aquifer systems

    Science.gov (United States)

    Macian-Sorribes, Hector; Pulido-Velazquez, Manuel; Tilmant, Amaury

    2015-04-01

    Stochastic programming methods are better suited to deal with the inherent uncertainty of inflow time series in water resource management. However, one of the most important hurdles in their use in practical implementations is the lack of generalized Decision Support System (DSS) shells, usually based on a deterministic approach. The purpose of this contribution is to present a general-purpose DSS shell, named Explicit Stochastic Programming Advanced Tool (ESPAT), able to build and solve stochastic programming problems for most water resource systems. It implements a hydro-economic approach, optimizing the total system benefits as the sum of the benefits obtained by each user. It has been coded using GAMS, and implements a Microsoft Excel interface with a GAMS-Excel link that allows the user to introduce the required data and recover the results. Therefore, no GAMS skills are required to run the program. The tool is divided into four modules according to its capabilities: 1) the ESPATR module, which performs stochastic optimization procedures in surface water systems using a Stochastic Dual Dynamic Programming (SDDP) approach; 2) the ESPAT_RA module, which optimizes coupled surface-groundwater systems using a modified SDDP approach; 3) the ESPAT_SDP module, capable of performing stochastic optimization procedures in small-size surface systems using a standard SDP approach; and 4) the ESPAT_DET module, which implements a deterministic programming procedure using non-linear programming, able to solve deterministic optimization problems in complex surface-groundwater river basins. The case study of the Mijares river basin (Spain) is used to illustrate the method. It consists in two reservoirs in series, one aquifer and four agricultural demand sites currently managed using historical (XIV century) rights, which give priority to the most traditional irrigation district over the XX century agricultural developments. Its size makes it possible to use either the SDP or

  4. Efficient method of solving the problems of steady-state oscillations of symmetric rectangular domains of general type

    Directory of Open Access Journals (Sweden)

    Олена Валентинівна Лупаренко

    2015-03-01

    Full Text Available When the wave processes in bounded elastic bodies are examined, we are faced with a significant complication of the structure of the wave field compared to the case of infinite bodies. This is due to the complex nature of the reflection of elastic waves from the boundaries of the body because the direction of the general flow of energy is changed. Even more complicated the structure of the wave field is, if there are inner boundaries between fields with different elastic properties. This entails the emergence of new wave effects associated with the dynamic stress concentration in the vicinity of the internal and external boundaries of the field. The nature of edge effects is changed too. They will depend not only from the size of the field but also from the geometric and elastic parameters defining the nature of heterogeneity. At the forefront are the questions of systematization of the results for the purpose of extradition of practical recommendations for optimal design of heterogeneous section details in particular conditions of its operation. Urgent enough is the question of the possibility of neglecting of structural heterogeneity and anisotropy of the section of the body in strengthening calculations and evaluation of possible errors. The mathematical basis for the study will be the expressions for particular solutions of equations of motion, constructed for infinite layers, which are sets of plane standing waves. When choosing the form of partial solutions, we must take into account not only the opportunity to satisfy the boundary conditions at the exterior boundary of the field, but also the mechanical properties at the interface of the sphere. This entails the complication of numerical-analytical algorithm of solving the problem

  5. Drug-related problems identification in general internal medicine: The impact and role of the clinical pharmacist and pharmacologist.

    Science.gov (United States)

    Guignard, Bertrand; Bonnabry, Pascal; Perrier, Arnaud; Dayer, Pierre; Desmeules, Jules; Samer, Caroline Flora

    2015-07-01

    Patients admitted to general internal medicine wards might receive a large number of drugs and be at risk for drug-related problems (DRPs) associated with increased morbidity and mortality. This study aimed to detect suboptimal drug use in internal medicine by a pharmacotherapy evaluation, to suggest treatment optimizations and to assess the acceptance and satisfaction of the prescribers. This was a 6-month prospective study conducted in two internal medicine wards. Physician rounds were attended by a pharmacist and a pharmacologist. An assessment grid was used to detect the DRPs in electronic prescriptions 24h in advance. One of the following interventions was selected, depending on the relevance and complexity of the DRPs: no intervention, verbal advice of treatment optimization, or written consultation. The acceptance rate and satisfaction of prescribers were measured. In total, 145 patients were included, and 383 DRPs were identified (mean: 2.6 DRPs per patient). The most frequent DRPs were drug interactions (21%), untreated indications (18%), overdosages (16%) and drugs used without a valid indication (10%). The drugs or drug classes most frequently involved were tramadol, antidepressants, acenocoumarol, calcium-vitamin D, statins, aspirin, proton pump inhibitors and paracetamol. The following interventions were selected: no intervention (51%), verbal advice of treatment optimization (42%), and written consultation (7%). The acceptance rate of prescribers was 84% and their satisfaction was high. Pharmacotherapy expertise during medical rounds was useful and well accepted by prescribers. Because of the modest allocation of pharmacists and pharmacologists in Swiss hospitals, complementary strategies would be required. Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  6. Study on the generalized WKB approximation for the inverse scattering problem at fixed energy for complex potentials

    International Nuclear Information System (INIS)

    Pozdnyakov, Yu.A.; Terenetskij, K.O.

    1981-01-01

    The approximate method for solution of the inverse scattering problem (ISP) at fixed energy for complex spherically symmetric potentials decreasing faster 1/r is considered. The method is based on using a generalized WKB approximation. For the designed potential V(r) a sufficiently ''close'' reference potential V(r) has been chosen. For both potentials S-matrix elements (ME) have been calculated and inversion procedure has been carried out. S-ME have been calculated for integral-valued and intermediate angular moment values. S-ME are presented in a graphical form for being restored reference, and restored potentials for proton scattering with Esub(p)=49.48 MeV energy on 12 C nuclei. The restoration is the better the ''closer'' the sought-for potential to the reference one. This allows to specify the potential by means of iterations: the restored potential can be used as a reference one, etc. The operation of a restored potential smoothing before the following iteration is introduced. Drawbacks and advantages of the ISP solution method under consideration are pointed out. The method application is strongly limited by the requirement that the energy should be higher than a certain ''critical'' one. The method is applicable in a wider region of particle energies (in the low-energies direction) than the ordinary WKB method. The method is more simple in realization conformably to complex potentials. The investigations carried out of the proposed ISP solution method at fixed energy for complex spherically-symmetric potentials allow to conclude that the method can be successFully applied to specify the central part of interaction of nucleons, α-particles and heavy ions of average and high energies with atomic nuclei [ru

  7. About solution of multipoint boundary problem of static analysis of deep beam with the use of combined application of finite element method and discrete-continual finite element method. part 1: formulation of the problem and general principles of approximation

    Directory of Open Access Journals (Sweden)

    Lyakhovich Leonid

    2017-01-01

    Full Text Available This paper is devoted to formulation and general principles of approximation of multipoint boundary problem of static analysis of deep beam with the use of combined application of finite element method (FEM discrete-continual finite element method (DCFEM. The field of application of DCFEM comprises structures with regular physical and geometrical parameters in some dimension (“basic” dimension. DCFEM presupposes finite element approximation for non-basic dimension while in the basic dimension problem remains continual. DCFEM is based on analytical solutions of resulting multipoint boundary problems for systems of ordinary differential equations with piecewise-constant coefficients.

  8. The formulation of dynamical contact problems with friction in the case of systems of rigid bodies and general discrete mechanical systems—Painlevé and Kane paradoxes revisited

    Science.gov (United States)

    Charles, Alexandre; Ballard, Patrick

    2016-08-01

    The dynamics of mechanical systems with a finite number of degrees of freedom (discrete mechanical systems) is governed by the Lagrange equation which is a second-order differential equation on a Riemannian manifold (the configuration manifold). The handling of perfect (frictionless) unilateral constraints in this framework (that of Lagrange's analytical dynamics) was undertaken by Schatzman and Moreau at the beginning of the 1980s. A mathematically sound and consistent evolution problem was obtained, paving the road for many subsequent theoretical investigations. In this general evolution problem, the only reaction force which is involved is a generalized reaction force, consistently with the virtual power philosophy of Lagrange. Surprisingly, such a general formulation was never derived in the case of frictional unilateral multibody dynamics. Instead, the paradigm of the Coulomb law applying to reaction forces in the real world is generally invoked. So far, this paradigm has only enabled to obtain a consistent evolution problem in only some very few specific examples and to suggest numerical algorithms to produce computational examples (numerical modeling). In particular, it is not clear what is the evolution problem underlying the computational examples. Moreover, some of the few specific cases in which this paradigm enables to write down a precise evolution problem are known to show paradoxes: the Painlevé paradox (indeterminacy) and the Kane paradox (increase in kinetic energy due to friction). In this paper, we follow Lagrange's philosophy and formulate the frictional unilateral multibody dynamics in terms of the generalized reaction force and not in terms of the real-world reaction force. A general evolution problem that governs the dynamics is obtained for the first time. We prove that all the solutions are dissipative; that is, this new formulation is free of Kane paradox. We also prove that some indeterminacy of the Painlevé paradox is fixed in this

  9. Doctor, can you spare some time? The role of workload in general practitioners' involvement in patients' mental health problems

    NARCIS (Netherlands)

    Zangtinge, E.M.

    2008-01-01

    GPs have an important position in the identification of patients’ mental health problems. As generalists, GPs are often the first health professionals contacted by patients with mental health problems and they are assigned to provide integrated care for both patients’ somatic and psychological

  10. Medical taking-decisions in the health primary assistance context. Transcendence of a problem from a general comprehensive doctor´s perspective.

    OpenAIRE

    Luis Alberto Corona Martínez

    2003-01-01

    This article is aimed at deepening on the consequences of the deficient development of abilities in decision making in the speciality of medicine, analysed from the prospective of the Comprehensive General Doctor . A psychological and professional characterisation of the Comprehensive General Doctors are developed from the analysis of their environment and on these bases the paper presents how these problems are reflected in the professional assistance. The conclusions are good to recognise h...

  11. Psychological vulnerability and problem gambling: an application of Durand Jacobs' general theory of addictions to electronic gaming machine playing in Australia.

    Science.gov (United States)

    McCormick, Jessica; Delfabbro, Paul; Denson, Linley A

    2012-12-01

    The aim of this study was to conduct an empirical investigation of the validity of Jacobs' (in J Gambl Behav 2:15-31, 1986) general theory of addictions in relation to gambling problems associated with electronic gaming machines (EGM). Regular EGM gamblers (n = 190) completed a series of standardised measures relating to psychological and physiological vulnerability, substance use, dissociative experiences, early childhood trauma and abuse and problem gambling (the Problem Gambling Severity Index). Statistical analysis using structural equation modelling revealed clear relationships between childhood trauma and life stressors and psychological vulnerability, dissociative-like experiences and problem gambling. These findings confirm and extend a previous model validated by Gupta and Derevensky (in J Gambl Stud 14: 17-49, 1998) using an adolescent population. The significance of these findings are discussed for existing pathway models of problem gambling, for Jacobs' theory, and for clinicians engaged in assessment and intervention.

  12. 15. Mendeleev's meeting on general and applied chemistry. Obninsk symposium. Radiological problems in nuclear energetics and industry conversion. Abstracts. V. 2

    International Nuclear Information System (INIS)

    1993-01-01

    Ecological aspects of nuclear-fuel engineering cycle and radiochemical technologies, radioactive waste processing and water purification, accidents at NPP and their consequences, ecological problems of industry conversion were discussed at the 15th Mendeleev's meeting on general and applied chemistry

  13. 15. Mendeleev's meeting on general and applied chemistry. Obninsk Symposium. Radioecological problems in nuclear energetics and in industry conversion. Abstracts. V. 1

    International Nuclear Information System (INIS)

    1993-01-01

    Works devoted to the problems of radioecology, radiochemistry, ecological monitoring, human health in zones subjected to radioactive contamination as a result of the Chernobyl accident, were presented at the 15. Mendeleev congress of general and applied chemistry which took place in Obninsk in 1993

  14. Parent Training on Generalized Use of Behavior Analytic Strategies for Decreasing the Problem Behavior of Children with Autism Spectrum Disorder: A Data-Based Case Study

    Science.gov (United States)

    Crone, Regina M.; Mehta, Smita Shukla

    2016-01-01

    Setting variables such as location of parent training, programming with common stimuli, generalization of discrete responses to non-trained settings, and subsequent reduction in child problem behavior may influence the effectiveness of interventions. The purpose of this study was to evaluate the effectiveness of home-versus clinic-based training…

  15. Talking about psychosocial problems: an observational study on changes in doctor–patient communication in general practice between 1977 and 2008.

    NARCIS (Netherlands)

    Butalid, L.; Bensing, J.M.; Verhaak, P.F.M.

    2014-01-01

    Objective: To examine whether GPs’ communication styles have changed since the introduction and implementation of clinical guidelines for psychosocial problems in Dutch general practice in the 1990s. Methods: From a database of 5184 consultations videotaped between 1977 and 2008, 512 consultations

  16. Generalized bi-quasi-variational inequalities for quasi-semi-monotone and bi-quasi-semi-monotone operators with applications in non-compact settings and minimization problems

    Directory of Open Access Journals (Sweden)

    Chowdhury Molhammad SR

    2000-01-01

    Full Text Available Results are obtained on existence theorems of generalized bi-quasi-variational inequalities for quasi-semi-monotone and bi-quasi-semi-monotone operators in both compact and non-compact settings. We shall use the concept of escaping sequences introduced by Border (Fixed Point Theorem with Applications to Economics and Game Theory, Cambridge University Press, Cambridge, 1985 to obtain results in non-compact settings. Existence theorems on non-compact generalized bi-complementarity problems for quasi-semi-monotone and bi-quasi-semi-monotone operators are also obtained. Moreover, as applications of some results of this paper on generalized bi-quasi-variational inequalities, we shall obtain existence of solutions for some kind of minimization problems with quasi- semi-monotone and bi-quasi-semi-monotone operators.

  17. The Black-Scholes option pricing problem in mathematical finance: generalization and extensions for a large class of stochastic processes

    Science.gov (United States)

    Bouchaud, Jean-Philippe; Sornette, Didier

    1994-06-01

    The ability to price risks and devise optimal investment strategies in thé présence of an uncertain "random" market is thé cornerstone of modern finance theory. We first consider thé simplest such problem of a so-called "European call option" initially solved by Black and Scholes using Ito stochastic calculus for markets modelled by a log-Brownien stochastic process. A simple and powerful formalism is presented which allows us to generalize thé analysis to a large class of stochastic processes, such as ARCH, jump or Lévy processes. We also address thé case of correlated Gaussian processes, which is shown to be a good description of three différent market indices (MATIF, CAC40, FTSE100). Our main result is thé introduction of thé concept of an optimal strategy in the sense of (functional) minimization of the risk with respect to the portfolio. If the risk may be made to vanish for particular continuous uncorrelated 'quasiGaussian' stochastic processes (including Black and Scholes model), this is no longer the case for more general stochastic processes. The value of the residual risk is obtained and suggests the concept of risk-corrected option prices. In the presence of very large deviations such as in Lévy processes, new criteria for rational fixing of the option prices are discussed. We also apply our method to other types of options, `Asian', `American', and discuss new possibilities (`doubledecker'...). The inclusion of transaction costs leads to the appearance of a natural characteristic trading time scale. L'aptitude à quantifier le coût du risque et à définir une stratégie optimale de gestion de portefeuille dans un marché aléatoire constitue la base de la théorie moderne de la finance. Nous considérons d'abord le problème le plus simple de ce type, à savoir celui de l'option d'achat `européenne', qui a été résolu par Black et Scholes à l'aide du calcul stochastique d'Ito appliqué aux marchés modélisés par un processus Log

  18. General general game AI

    OpenAIRE

    Togelius, Julian; Yannakakis, Georgios N.; 2016 IEEE Conference on Computational Intelligence and Games (CIG)

    2016-01-01

    Arguably the grand goal of artificial intelligence research is to produce machines with general intelligence: the capacity to solve multiple problems, not just one. Artificial intelligence (AI) has investigated the general intelligence capacity of machines within the domain of games more than any other domain given the ideal properties of games for that purpose: controlled yet interesting and computationally hard problems. This line of research, however, has so far focuse...

  19. On quasistability radius of a vector trajectorial problem with a principle of optimality generalizing Pareto and lexicographic principles

    Directory of Open Access Journals (Sweden)

    Sergey E. Bukhtoyarov

    2005-05-01

    Full Text Available A multicriterion linear combinatorial problem with a parametric principle of optimality is considered. This principle is defined by a partitioning of partial criteria onto Pareto preference relation groups within each group and the lexicographic preference relation between them. Quasistability of the problem is investigated. This type of stability is a discrete analog of Hausdorff lower semi-continuity of the multiple-valued mapping that defines the choice function. A formula of quasistability radius is derived for the case of the metric l∞. Some known results are stated as corollaries. Mathematics Subject Classification 2000: 90C05, 90C10, 90C29, 90C31.

  20. Mental health problems and the presentation of minor illnesses: data from a 30-year follow-up in general practice.

    NARCIS (Netherlands)

    Olde Hartman, T.C.; Rijswijk, E. van; Ravesteijn, H.J. van; Hassink-Franke, L.J.A.; Bor, H.; Weel-Baumgarten, E.M. van; Lucassen, P.L.B.J.

    2008-01-01

    BACKGROUND: Somatic comorbidity in patients with depression and anxiety is very prevalent and mainly studied with respect to chronic conditions. Patients with mental health problems are high utilizers of medical care. This may be a result of their functional impairment and illness behaviour, but

  1. Linking Complex Problem Solving and General Mental Ability to Career Advancement: Does a Transversal Skill Reveal Incremental Predictive Validity?

    Science.gov (United States)

    Mainert, Jakob; Kretzschmar, André; Neubert, Jonas C.; Greiff, Samuel

    2015-01-01

    Transversal skills, such as complex problem solving (CPS) are viewed as central twenty-first-century skills. Recent empirical findings have already supported the importance of CPS for early academic advancement. We wanted to determine whether CPS could also contribute to the understanding of career advancement later in life. Towards this end, we…

  2. Assessing the Social Skills and Problem Behaviors of Adolescents With Severe Disabilities Enrolled in General Education Classes.

    Science.gov (United States)

    Lyons, Gregory L; Huber, Heartley B; Carter, Erik W; Chen, Rui; Asmus, Jennifer M

    2016-07-01

    Although enhancing the social competence of students with severe disabilities has long remained a prominent focus of school-based intervention efforts, relatively little attention has focused on identifying the most critical social and behavioral needs of students during high school. We examined the social skills and problem behaviors of 137 adolescents with severe disabilities from the vantage point of both special educators and parents. We sought to identify areas of potential intervention need, explore factors associated with social skill and problem behavior ratings, and examine the extent to which teachers and parents converged in their assessments of these needs. Our findings indicate teachers and parents of high school students with severe disabilities rated social skills as considerably below average and problem behaviors as above average. In addition, lower social skills ratings were evident for students with greater support needs, lower levels of overall adaptive behavior, and a special education label of autism. We found moderate consistency in the degree to which teachers and parents aligned in their assessments of both social skills and problem behavior. We offer recommendations for assessment and intervention focused on strengthening the social competence of adolescents with severe disabilities within secondary school classrooms, as well as promising avenues for future research.

  3. The assessment of recalled parental rearing behavior and its relationship to life satisfaction and interpersonal problems: a general population study

    Directory of Open Access Journals (Sweden)

    Hinz Andreas

    2009-03-01

    Full Text Available Abstract Background Parental rearing behavior is a significant etiological factor for the vulnerability of psychopathology and has been an issue of clinical research for a long time. For this scope instruments are important who asses economically recalled parental rearing behavior in a clinical practice. Therefore, a short German instrument for the assessment of the recalled parental rearing behavior Fragebogen zum erinnerten elterlichen Erziehungsverhalten (FEE was psychometrically evaluated [Recalled Parental Rearing Behavior]. Methods This questionnaire was evaluated in a representative population sample (N = 2.948 in Germany which included 44.2% male and 55.8% female persons with a mean age of M = 47.35 (SD = 17.10, range = 18–92. For the content evaluation of the FEE the Life Satisfaction Questionnaire (FLZ and the Inventory of Interpersonal Problems (IIP was filled out by the participants. Results The FEE scales yielded a good to satisfactory internal consistency and split-half reliability. Its three factors (rejection/punishment, emotional warmth, control/overprotection correlated positively with most of the areas of life satisfaction. Furthermore, positive associations between interpersonal problems and parental rejection and control could be identified. Conclusion The FEE is a short, reliable and valid instrument that can be applied in the clinical practice. In addition, the data proved an association between recalled parental rearing behavior, life satisfaction and interpersonal problems conform to the literature. Finally, specific problems with the retrospective assessment of parental rearing behavior were addressed as well.

  4. Assessing the Social Skills and Problem Behaviors of Adolescents with Severe Disabilities Enrolled in General Education Classes

    Science.gov (United States)

    Lyons, Gregory L.; Huber, Heartley B.; Carter, Erik W.; Chen, Rui; Asmus, Jennifer M.

    2016-01-01

    Although enhancing the social competence of students with severe disabilities has long remained a prominent focus of school-based intervention efforts, relatively little attention has focused on identifying the most critical social and behavioral needs of students during high school. We examined the social skills and problem behaviors of 137…

  5. Multi-objective optimization of generalized reliability design problems using feature models-A concept for early design stages

    International Nuclear Information System (INIS)

    Limbourg, Philipp; Kochs, Hans-Dieter

    2008-01-01

    Reliability optimization problems such as the redundancy allocation problem (RAP) have been of considerable interest in the past. However, due to the restrictions of the design space formulation, they may not be applicable in all practical design problems. A method with high modelling freedom for rapid design screening is desirable, especially in early design stages. This work presents a novel approach to reliability optimization. Feature modelling, a specification method originating from software engineering, is applied for the fast specification and enumeration of complex design spaces. It is shown how feature models can not only describe arbitrary RAPs but also much more complex design problems. The design screening is accomplished by a multi-objective evolutionary algorithm for probabilistic objectives. Comparing averages or medians may hide the true characteristics of this distributions. Therefore the algorithm uses solely the probability of a system dominating another to achieve the Pareto optimal set. We illustrate the approach by specifying a RAP and a more complex design space and screening them with the evolutionary algorithm

  6. The Teaching of General Solution Methods to Pattern Finding Problems through Focusing on an Evaluation and Improvement Process.

    Science.gov (United States)

    Ishida, Junichi

    1997-01-01

    Examines the effects of a teaching strategy in which fifth-grade students evaluated the strengths or weaknesses of solution methods to pattern finding problems, including an experimental and control group each consisting of 34 elementary students, in Japan. The experimental group showed a significantly better performance on the retention test…

  7. Large-Scale Studies on the Transferability of General Problem-Solving Skills and the Pedagogic Potential of Physics

    Science.gov (United States)

    Mashood, K. K.; Singh, Vijay A.

    2013-01-01

    Research suggests that problem-solving skills are transferable across domains. This claim, however, needs further empirical substantiation. We suggest correlation studies as a methodology for making preliminary inferences about transfer. The correlation of the physics performance of students with their performance in chemistry and mathematics in…

  8. Modified truncated randomized singular value decomposition (MTRSVD) algorithms for large scale discrete ill-posed problems with general-form regularization

    Science.gov (United States)

    Jia, Zhongxiao; Yang, Yanfei

    2018-05-01

    In this paper, we propose new randomization based algorithms for large scale linear discrete ill-posed problems with general-form regularization: subject to , where L is a regularization matrix. Our algorithms are inspired by the modified truncated singular value decomposition (MTSVD) method, which suits only for small to medium scale problems, and randomized SVD (RSVD) algorithms that generate good low rank approximations to A. We use rank-k truncated randomized SVD (TRSVD) approximations to A by truncating the rank- RSVD approximations to A, where q is an oversampling parameter. The resulting algorithms are called modified TRSVD (MTRSVD) methods. At every step, we use the LSQR algorithm to solve the resulting inner least squares problem, which is proved to become better conditioned as k increases so that LSQR converges faster. We present sharp bounds for the approximation accuracy of the RSVDs and TRSVDs for severely, moderately and mildly ill-posed problems, and substantially improve a known basic bound for TRSVD approximations. We prove how to choose the stopping tolerance for LSQR in order to guarantee that the computed and exact best regularized solutions have the same accuracy. Numerical experiments illustrate that the best regularized solutions by MTRSVD are as accurate as the ones by the truncated generalized singular value decomposition (TGSVD) algorithm, and at least as accurate as those by some existing truncated randomized generalized singular value decomposition (TRGSVD) algorithms. This work was supported in part by the National Science Foundation of China (Nos. 11771249 and 11371219).

  9. Runge-Kutta and Hermite Collocation for a biological invasion problem modeled by a generalized Fisher equation

    International Nuclear Information System (INIS)

    Athanasakis, I E; Papadopoulou, E P; Saridakis, Y G

    2014-01-01

    Fisher's equation has been widely used to model the biological invasion of single-species communities in homogeneous one dimensional habitats. In this study we develop high order numerical methods to accurately capture the spatiotemporal dynamics of the generalized Fisher equation, a nonlinear reaction-diffusion equation characterized by density dependent non-linear diffusion. Working towards this direction we consider strong stability preserving Runge-Kutta (RK) temporal discretization schemes coupled with the Hermite cubic Collocation (HC) spatial discretization method. We investigate their convergence and stability properties to reveal efficient HC-RK pairs for the numerical treatment of the generalized Fisher equation. The Hadamard product is used to characterize the collocation discretized non linear equation terms as a first step for the treatment of generalized systems of relevant equations. Numerical experimentation is included to demonstrate the performance of the methods

  10. On The Fekete-Szegö Problem for Generalized Class Mα,γ(β Defined By Differential Operator

    Directory of Open Access Journals (Sweden)

    Fethiye Müge SAKAR

    2016-11-01

    Full Text Available In this study the classical Fekete-Szegö problem was investigated. Given f(z=z+a2z2+a3z3+...  to be an analytic standartly normalized function in the open unit disk U={z ∈ C : |z|<1}. For |a3-μa22|, a sharp maximum value is provided through the classes of S*α,γ(β order β and type α under the condition of μ≥1.

  11. Polygenic scores for schizophrenia and educational attainment are associated with behavioural problems in early childhood in the general population

    NARCIS (Netherlands)

    Jansen, Philip R; Polderman, Tinca J C; Bolhuis, Koen; van der Ende, Jan; Jaddoe, Vincent W V; Verhulst, Frank C; White, Tonya; Posthuma, Danielle; Tiemeier, Henning

    BACKGROUND: Genome-wide association studies in adults have identified numerous genetic variants related to psychiatric disorders and related traits, such as schizophrenia and educational attainment. However, the effects of these genetic variants on behaviour in the general population remain to be

  12. The general practitioner as the first contacted health professional by patients with psychosocial problems: a European study.

    NARCIS (Netherlands)

    Boerma, W.G.W.; Verhaak, P.F.M.

    1999-01-01

    Background: there are considerable differences between and within countries in the involvement of general practitioners (GPs) in psychosocial care. This study aimed to describe the self-perceived role of GPs in 30 European countries as the first contacted professional for patients with psychosocial

  13. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R; Gaudez, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration, l'equilibrage des pression entre l'eau lourde et le gaz, le montage

  14. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R.; Gaudez, J.C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration

  15. A general analytical solution for the stochastic Milne problem using Karhunen–Loeve (K–L) expansion

    International Nuclear Information System (INIS)

    Hussein, A.; Selim, M.M.

    2013-01-01

    This paper considers the solution of the stochastic integro-differential equation of Milne problem with random operator. The Pomraning–Eddington method is implemented to get a closed form solution deterministically. Relying on the spectral properties of the covariance function, the Karhunen–Loeve (K–L) expansion is used to represent the input stochastic process in the deterministic solution. This leads to an explicit expression for the solution process as a multivariate functional of a set of uncorrelated random variables. By using different distributions for these variables, the work is realized through computing the mean and the variance of the solution. The numerical results are found in agreement with those obtained in the literature. -- Highlights: •The solution of the stochastic Milne problem is considered. •We dealt with the random cross-section itself not with the optical transformation of it. •Pomraning–Eddington method together with the (K–L) expansion were implemented. •The solution process is obtained as a functional of a set of uncorrelated random variables. •Good results are obtained for different distributions of these variables

  16. The frequency of smoking and problem drinking among general hospital inpatients in Brazil - using the AUDIT and Fagerström questionnaires

    Directory of Open Access Journals (Sweden)

    Neliana Buzi Figlie

    2000-09-01

    Full Text Available CONTEXT: Although the CAGE questionnaire is one of the most widely used alcohol screening instruments, it has been criticized for not identifying people who are drinking heavily or who have alcohol related problems but do not as yet show symptoms of alcohol dependence. The AUDIT (Alcohol Use Disorder Identification Test questionnaire was developed by WHO as a screening instrument specifically designed to identify problem drinkers, as well as those who were already dependent on alcohol. OBJECTIVE: The aim of this study was to use the AUDIT and Fagerström questionnaires in a general hospital inpatient population to measure the frequency of problem drinking and nicotine dependence, and to see if levels varied between medical speciality. DESIGN: Retrospective cross-sectional study. SETTING: Federally funded public teaching hospital. SAMPLE: 275 inpatients from both genders. MAIN MEASUREMENTS: Socio-demographic data, AUDIT (Alcohol Use Disorders Identification Test and Fagerström Test for Nicotine Dependence. RESULTS: We interviewed 275 inpatients, 49% of whom were men and 51% women. Thirty-four patients were identified as "cases" by the Audit questionnaire; 22% of the male patients and 3% of the females. Just over 21% of inpatients were current smokers. The gastroenterology (26% and general medicine (16% inpatient units had the largest number of individual cases. CONCLUSIONS: Only by knowing the prevalence of alcohol abuse/dependence and nicotine dependence in a general hospital can we evaluate the need for a specialized liaison service to identify and treat these patients.

  17. Striking trends in the incidence of health problems in The Netherlands (2002-05). Findings from a new strategy for surveillance in general practice.

    Science.gov (United States)

    Biermans, Marion C J; Spreeuwenberg, Peter; Verheij, Robert A; de Bakker, Dinny H; de Vries Robbé, Pieter F; Zielhuis, Gerhard A

    2009-06-01

    This study aimed to detect striking trends based on a new strategy for monitoring public health. We used data over 4 years from electronic medical records of a large, nationally representative network of general practices. Episodes were either directly recorded by general practitioners (GPs) or were constructed using a new record linkage method (EPICON). The episodes were used to estimate raw morbidity rates for all codes of the International Classification of Primary Care (ICPC). Multilevel Poisson regression models were used to analyse the trend over time for 15 health problems that showed an obvious change over time. Based on these models, we calculated adjusted incidence rates corrected for clustering, sex and age. During 2002-05, both men and women increasingly consulted the GP because of concern about a drug reaction, a change in faeces/bowel movements and urination problems. Men showed an increase in consultations for prostate problems and venereal diseases. The incidence of chronic internal knee derangement decreased for both sexes. Women consulted their GP less frequently about sterilization and fear of being pregnant. The strategy developed proved to be useful to detect trends across a short period of time. Changes in the health care market, such as the increasing availability of over-the-counter drugs and various large advertising campaigns for medications may explain some of the findings. The increasing incidence of health problems in the urogenital area deserves attention as it could reflect increases in the incidence of sexually transmitted diseases (STDs) and urinary tract infections.

  18. Magnetic diagnostics: General principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems

    International Nuclear Information System (INIS)

    Pustovitov, V.D.

    2001-01-01

    Restrictions on magnetic diagnostics are discussed. Being related to the integral nature of the measurable quantities, these follow from the fundamental laws of electromagnetism. A series of examples demonstrating the strength of these restrictions is analysed. The general rule is emphasized that information obtained from external magnetic measurements is insufficient for reliable evaluation of plasma current and pressure profiles in tokamaks and in stellarators. The underlying reason is that outside the plasma the self-field of the equilibrium plasma currents is determined by the boundary conditions on the plasma surface alone. (author)

  19. Magnetic diagnostics: general principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems

    Energy Technology Data Exchange (ETDEWEB)

    Pustovitov, V.D.

    2000-04-01

    The restrictions of the magnetic diagnostics are discussed. Being related to the integral nature of the measurable quantities, they follow from the fundamental laws of electromagnetism. A series of particular examples demonstrating the strength of these restrictions is given and analyzed. A general rule is emphasized that the information obtained from external magnetic measurements is obviously insufficient for the reliable evaluation of plasma current and pressure profiles in tokamaks or in stellarators. The underlying reason is that outside the plasma the own field of the equilibrium plasma currents is determined by the boundary conditions on the plasma surface only. (author)

  20. A note on the solution of general Falkner-Skan problem by two novel semi-analytical techniques

    Directory of Open Access Journals (Sweden)

    Ahmed Khidir

    2015-12-01

    Full Text Available The aim of this paper is to give a presentation of two new iterative methods for solving non-linear differential equations, they are successive linearisation method and spectral homotopy perturbation method. We applied these techniques on the non-linear boundary value problems of Falkner-Skan type. The methods used to find a recursive former for higher order equations that are solved using the Chebyshev spectral method to find solutions that are accurate and converge rapidly to the full numerical solution. The methods are illustrated by progressively applying the technique to the Blasius boundary layer equation, the Falkner-Skan equation and finally, the magnetohydrodynamic (MHD Falkner-Skan equation. The solutions are compared to other methods in the literature such as the homotopy analysis method and the spectral-homotopy analysis method with focus on the accuracy and convergence of this new techniques.

  1. Axially symmetric two-body problem in general relativity. III. Bondi mass loss and the failure of the quadrupole formula

    International Nuclear Information System (INIS)

    Cooperstock, F.I.; Hobill, D.W.

    1979-01-01

    Suggested difficulties and criticism regarding earlier work is addressed. It is demonstrated that the rate of gravitational energy loss from the authors' model free-fall system employing the widely accepted Bondi method agrees precisely with the results described in prior works. Origins of the breakdown of the quadrupole formalism for free fall, previously indicated, are now delineated in detail. The role of source structure in the energy loss rate re-emerges, bringing into question much of the earlier work of others. The iterative technique with flat-space wave operators is justified. A new approach to quasiperiodic systems such as binary stars is described. Ideally modeled upon the actual birth of such systems, it evolves from an initially stationary configuration, again avoiding the problems and ambiguities regarding incoming radiation

  2. A Generalized Semi-Analytical Solution for the Dispersive Henry Problem: Effect of Stratification and Anisotropy on Seawater Intrusion

    Directory of Open Access Journals (Sweden)

    Marwan Fahs

    2018-02-01

    Full Text Available The Henry problem (HP continues to play a useful role in theoretical and practical studies related to seawater intrusion (SWI into coastal aquifers. The popularity of this problem is attributed to its simplicity and precision to the existence of semi-analytical (SA solutions. The first SA solution has been developed for a high uniform diffusion coefficient. Several further studies have contributed more realistic solutions with lower diffusion coefficients or velocity-dependent dispersion. All the existing SA solutions are limited to homogenous and isotropic domains. This work attempts to improve the realism of the SA solution of the dispersive HP by extending it to heterogeneous and anisotropic coastal aquifers. The solution is obtained using the Fourier series method. A special hydraulic conductivity–depth model describing stratified heterogeneity is used for mathematical convenience. An efficient technique is developed to solve the flow and transport equations in the spectral space. With this technique, we show that the HP can be solved in the spectral space with the salt concentration as primary unknown. Several examples are generated, and the SA solutions are compared against an in-house finite element code. The results provide high-quality data assessed by quantitative indicators that can be effectively used for code verification in realistic configurations of heterogeneity and anisotropy. The SA solution is used to explain contradictory results stated in the previous works about the effect of anisotropy on the saltwater wedge. It is also used to investigate the combined influence of stratification and anisotropy on relevant metrics characterizing SWI. At a constant gravity number, anisotropy leads to landward migration of the saltwater wedge, more intense saltwater flux, a wider mixing zone and shallower groundwater discharge zone to the sea. The influence of stratified heterogeneity is more pronounced in highly anisotropic aquifers. The

  3. The Clinical Assessment Study of the Hand (CAS-HA: a prospective study of musculoskeletal hand problems in the general population

    Directory of Open Access Journals (Sweden)

    Marshall Michelle

    2007-08-01

    Full Text Available Abstract Background Pain in the hand affects an estimated 12–21% of the population, and at older ages the hand is one of the most common sites of pain and osteoarthritis. The association between symptomatic hand osteoarthritis and disability in everyday life has not been studied in detail, although there is evidence that older people with hand problems suffer significant pain and disability. Despite the high prevalence of hand problems and the limitations they cause in older adults, little attention has been paid to the hand by health planners and policy makers. We plan to conduct a prospective, population-based, observational cohort study designed in parallel with our previously reported cohort study of knee pain, to describe the course of musculoskeletal hand problems in older adults and investigate the relative merits of different approaches to classification and defining prognosis. Methods/Design All adults aged 50 years and over registered with two general practices in North Staffordshire will be invited to take part in a two-stage postal survey. Respondents to the survey who indicate that they have experienced hand pain or problems within the previous 12 months will be invited to attend a research clinic for a detailed assessment. This will consist of clinical interview, hand assessment, screening test of lower limb function, digital photography, plain x-rays, anthropometric measurement and brief self-complete questionnaire. All consenting clinic attenders will be followed up by (i general practice medical record review, (ii repeat postal questionnaire at 18-months, and (iii repeat postal questionnaire at 3 years. Discussion This paper describes the protocol for the Clinical Assessment Study of the Hand (CAS-HA, a prospective, population-based, observational cohort study of community-dwelling older adults with hand pain and hand problems based in North Staffordshire.

  4. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel

    International Nuclear Information System (INIS)

    Roche, R.; Gaudez, J.C.

    1964-01-01

    In the framework of research carried out on a CO 2 -cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [fr

  5. The effects of duration of exposure to the REAPS model in developing students' general creativity and creative problem solving in science

    Science.gov (United States)

    Alhusaini, Abdulnasser Alashaal F.

    The Real Engagement in Active Problem Solving (REAPS) model was developed in 2004 by C. June Maker and colleagues as an intervention for gifted students to develop creative problem solving ability through the use of real-world problems. The primary purpose of this study was to examine the effects of the REAPS model on developing students' general creativity and creative problem solving in science with two durations as independent variables. The long duration of the REAPS model implementation lasted five academic quarters or approximately 10 months; the short duration lasted two quarters or approximately four months. The dependent variables were students' general creativity and creative problem solving in science. The second purpose of the study was to explore which aspects of creative problem solving (i.e., generating ideas, generating different types of ideas, generating original ideas, adding details to ideas, generating ideas with social impact, finding problems, generating and elaborating on solutions, and classifying elements) were most affected by the long duration of the intervention. The REAPS model in conjunction with Amabile's (1983; 1996) model of creative performance provided the theoretical framework for this study. The study was conducted using data from the Project of Differentiation for Diverse Learners in Regular Classrooms (i.e., the Australian Project) in which one public elementary school in the eastern region of Australia cooperated with the DISCOVER research team at the University of Arizona. All students in the school from first to sixth grade participated in the study. The total sample was 360 students, of which 115 were exposed to a long duration and 245 to a short duration of the REAPS model. The principal investigators used a quasi-experimental research design in which all students in the school received the treatment for different durations. Students in both groups completed pre- and posttests using the Test of Creative Thinking

  6. Analysis and Characterization of Damage and Failure Utilizing a Generalized Composite Material Model Suitable for Use in Impact Problems

    Science.gov (United States)

    Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Khaled, Bilal; Hoffarth, Canio; Rajan, Subramaniam; Blankenhorn, Gunther

    2016-01-01

    A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in state-of-the art composite impact models is under development. In particular, a next generation composite impact material model, jointly developed by the FAA and NASA, is being implemented into the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage, and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters (such as modulus and strength). The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a semi-coupled approach is employed where the overall damage in a particular coordinate direction is assumed to be a multiplicative combination of the damage in that direction resulting from the applied loads in the various coordinate directions. Due to the fact that the plasticity and damage models are uncoupled, test procedures and methods to both characterize the damage model and to covert the material stress-strain curves from the true (damaged) stress space to the effective (undamaged) stress space have been developed. A methodology has been developed to input the experimentally determined composite failure surface in a tabulated manner. An analytical approach is then utilized to track how close the current stress state is to the failure surface.

  7. The effectiveness of clinical problem-based learning model of medico-jurisprudence education on general law knowledge for Obstetrics/Gynecological interns.

    Science.gov (United States)

    Chang, Hui-Chin; Wang, Ning-Yen; Ko, Wen-Ru; Yu, You-Tsz; Lin, Long-Yau; Tsai, Hui-Fang

    2017-06-01

    The effective education method of medico-jurisprudence for medical students is unclear. The study was designed to evaluate the effectiveness of problem-based learning (PBL) model teaching medico-jurisprudence in clinical setting on General Law Knowledge (GLK) for medical students. Senior medical students attending either campus-based law curriculum or Obstetrics/Gynecology (Ob/Gyn) clinical setting morning meeting from February to July in 2015 were enrolled. A validated questionnaire comprising 45 questions were completed before and after the law education. The interns attending clinical setting small group improvisation medico-jurisprudence problem-based learning education had significantly better GLK scores than the GLK of students attending campus-based medical law education course after the period studied. PBL teaching model of medico-jurisprudence is an ideal alternative pedagogy model in medical law education curriculum. Copyright © 2017. Published by Elsevier B.V.

  8. The Einstein Equations and the Large Scale Behavior of Gravitational Fields: 50 years of the Cauchy Problem in General Relativity

    International Nuclear Information System (INIS)

    Coles, P

    2006-01-01

    Cosmology is a discipline that encompasses many diverse aspects of physics and astronomy. This is part of its attraction, but also a reason why it is difficult for new researchers to acquire sufficient grounding to enable them to make significant contributions early in their careers. For this reason there are many cosmology textbooks aimed at the advanced undergraduate/beginning postgraduate level. Physical Foundations of Cosmology by Viatcheslav Mukhanov is a worthy new addition to this genre. Like most of its competitors it does not attempt to cover every single aspect of the subject but chooses a particular angle and tries to unify its treatment around that direction. Mukhanov has chosen to focus on the fundamental principles underlying modern cosmological research at the expense of some detail at the frontiers. The book places great emphasis on the particle-astrophysics interface and issues connected with the thermal history of the big-bang model. The treatment of big-bang nucleosynthesis is done in much more detail than in most texts at a similar level, for example. It also contains a very extended and insightful discussion of inflationary models. Mukhanov makes great use of approximate analytical arguments to develop physical intuition rather than concentrating on numerical approaches. The book is quite mathematical, but not in a pedantically formalistic way. There is much use of 'order-of-magnitude' dimensional arguments which undergraduate students often find difficult to get the hang of, but which they would do well to assimilate as early as possible in their research careers. The text is peppered with problems for the reader to solve, some straightforward and some exceedingly difficult. Solutions are not provided. The price to be paid for this foundational approach is that there is not much about observational cosmology in this book, and neither is there much about galaxy formation or large-scale structure. It also neglects some of the trendier recent

  9. Type D personality in the general population: a systematic review of health status, mechanisms of disease, and work-related problems

    Directory of Open Access Journals (Sweden)

    Denollet Johan

    2010-01-01

    Full Text Available Abstract Background The objective was to review all available literature concerning Type D (distressed personality among the general population and to discuss its implications for research on health status, disease-promoting mechanisms and work-related problems in non-clinical populations. Methods A computerized search of the literature was performed independently and in duplicate by both investigators on December 21st, 2009. Published research reports were included if they studied Type D personality among the general population. Nineteen articles were selected and they were subjected to an 11-item standardised quality checklist by both investigators. Results The methodological quality of the selected studies was adequate to high. The studies included in this review showed that the presence of Type D characteristics had a negative impact on mental health status (more symptoms of depression, anxiety, post-traumatic stress disorder, mental distress, passive coping, and less social support and physical health status (more somatic complaints, lower health status, more influenza-like illness reporting. Other studies reported on behavioral and biological mechanisms of disease in apparently healthy individuals with a Type D personality. Finally, some studies also showed a negative effect of Type D personality on work-related problems (higher absence-leave, higher levels of vital exhaustion and burnout, and more work-related stress. Conclusions Type D personality is a vulnerability factor for general psychological distress that affects mental and physical health status and is associated with disease-promoting mechanisms and work-related problems in apparently healthy individuals.

  10. Collective processes in a tokamak with high-energy particles: general problems of the linear theory of Alfven instabilities of a tokamak with high-energy ions

    International Nuclear Information System (INIS)

    Mikhailovskii, A.B.

    1986-01-01

    Some general problems of the theory of Alfven instabilities of a tokamak with high-energy ions are considered. It is assumed that such ions are due to either ionization of fast neutral atoms, injected into the tokamak, or production of them under thermo-nuclear conditions. Small-oscillation equations are derived for the Alfven-type waves, which allow for both destabilizing effects, associated with the high-energy particles, and stabilizing ones, such as effects of shear and bulk-plasm dissipation. A high-energy ion contribution is calculated into the growth rate of the Alfven waves. The author considers the role of trapped-electron collisional dissipation

  11. A general formulation of discrete-time quantum mechanics: Restrictions on the action and the relation of unitarity to the existence theorem for initial-value problems

    International Nuclear Information System (INIS)

    Khorrami, M.

    1995-01-01

    A general formulation for discrete-time quantum mechanics, based on Feynman's method in ordinary quantum mechanics, is presented. It is shown that the ambiguities present in ordinary quantum mechanics (due to noncommutativity of the operators), are no longer present here. Then the criteria for the unitarity of the evolution operator are examined. It is shown that the unitarity of the evolution operator puts restrictions on the form of the action, and also implies the existence of a solution for the classical initial-value problem. 13 refs

  12. Mental health problems are associated with low-frequency fluctuations in reaction time in a large general population sample. The TRAILS study.

    Science.gov (United States)

    Bastiaansen, J A; van Roon, A M; Buitelaar, J K; Oldehinkel, A J

    2015-02-01

    Increased intra-subject reaction time variability (RT-ISV) as coarsely measured by the standard deviation (RT-SD) has been associated with many forms of psychopathology. Low-frequency RT fluctuations, which have been associated with intrinsic brain rhythms occurring approximately every 15-40s, have been shown to add unique information for ADHD. In this study, we investigated whether these fluctuations also relate to attentional problems in the general population, and contribute to the two major domains of psychopathology: externalizing and internalizing problems. RT was monitored throughout a self-paced sustained attention task (duration: 9.1 ± 1.2 min) in a Dutch population cohort of young adults (n=1455, mean age: 19.0 ± 0.6 years, 55.1% girls). To characterize temporal fluctuations in RT, we performed direct Fourier Transform on externally validated frequency bands based on frequency ranges of neuronal oscillations: Slow-5 (0.010-0.027 Hz), Slow-4 (0.027-0.073 Hz), and three additional higher frequency bands. Relative magnitude of Slow-4 fluctuations was the primary predictor in regression models for attentional, internalizing and externalizing problems (measured by the Adult Self-Report questionnaire). Additionally, stepwise regression models were created to investigate (a) whether Slow-4 significantly improved the prediction of problem behaviors beyond the RT-SD and (b) whether the other frequency bands provided important additional information. The magnitude of Slow-4 fluctuations significantly predicted attentional and externalizing problems and even improved model fit after modeling RT-SD first (R(2) change=0.6%, Pfrequency bands provided additional information. Low-frequency RT fluctuations have added predictive value for attentional and externalizing, but not internalizing problems beyond global differences in variability. This study extends previous findings in clinical samples of children with ADHD to adolescents from the general population and

  13. Predictive value of general movements' quality in low-risk infants for minor neurological dysfunction and behavioural problems at preschool age.

    Science.gov (United States)

    Bennema, Anne N; Schendelaar, Pamela; Seggers, Jorien; Haadsma, Maaike L; Heineman, Maas Jan; Hadders-Algra, Mijna

    2016-03-01

    General movement (GM) assessment is a well-established tool to predict cerebral palsy in high-risk infants. Little is known on the predictive value of GM assessment in low-risk populations. To assess the predictive value of GM quality in early infancy for the development of the clinically relevant form of minor neurological dysfunction (complex MND) and behavioral problems at preschool age. Prospective cohort study. A total of 216 members of the prospective Groningen Assisted Reproductive Techniques (ART) cohort study were included in this study. ART did not affect neurodevelopmental outcome of these relatively low-risk infants born to subfertile parents. GM quality was determined at 2 weeks and 3 months. At 18 months and 4 years, the Hempel neurological examination was used to assess MND. At 4 years, parents completed the Child Behavior Checklist; this resulted in the total problem score (TPS), internalizing problem score (IPS), and externalizing problem score (EPS). Predictive values of definitely (DA) and mildly (MA) abnormal GMs were calculated. DA GMs at 2 weeks were associated with complex MND at 18 months and atypical TPS and IPS at 4 years (all ppredictive value of DA GMs at 2 weeks were rather low (13%-60%); specificity and negative predictive value were excellent (92%-99%). DA GMs at 3 months occurred too infrequently to calculate prediction. MA GMs were not associated with outcome. GM quality as a single predictor for complex MND and behavioral problems at preschool age has limited clinical value in children at low risk for developmental disorders. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Motivation to change risky drinking and motivation to seek help for alcohol risk drinking among general hospital inpatients with problem drinking and alcohol-related diseases.

    Science.gov (United States)

    Lau, Katharina; Freyer-Adam, Jennis; Gaertner, Beate; Rumpf, Hans-Jürgen; John, Ulrich; Hapke, Ulfert

    2010-01-01

    The objective of this study was to analyze motivation to change drinking behavior and motivation to seek help in general hospital inpatients with problem drinking and alcohol-related diseases. The sample consisted of 294 general hospital inpatients aged 18-64 years. Inpatients with alcohol-attributable disease were classified according to its alcohol-attributable fraction (AAF; AAF=1, AAFmotivation between the AAF groups were analyzed. Furthermore, differences in motivation to change, in motivation to seek help and in the amount of alcohol consumed from baseline to follow-up between the AAF groups were evaluated. During hospital stay, motivation to change was higher among inpatients with alcohol-attributable diseases than among inpatients who had no alcohol-attributable diseases [F(2)=18.40, PMotivation to seek help was higher among inpatients with AAF=1 than among inpatients with AAFmotivation to change drinking behavior remained stable within 12 months of hospitalization, motivation to seek help decreased. The amount of alcohol consumed decreased in all three AAF groups. Data suggest that hospital stay seems to be a "teachable moment." Screening for problem drinking and motivation differentiated by AAFs might be a tool for early intervention. Copyright 2010 Elsevier Inc. All rights reserved.

  15. An alcohol-focused intervention versus a healthy living intervention for problem drinkers identified in a general hospital setting (ADAPTA): study protocol for a randomized, controlled pilot trial.

    Science.gov (United States)

    Watson, Judith; Tober, Gillian; Raistrick, Duncan; Mdege, Noreen; Dale, Veronica; Crosby, Helen; Godfrey, Christine; Lloyd, Charlie; Toner, Paul; Parrott, Steve

    2013-04-30

    Alcohol misuse is a major cause of premature mortality and ill health. Although there is a high prevalence of alcohol problems among patients presenting to general hospital, many of these people are not help seekers and do not engage in specialist treatment. Hospital admission is an opportunity to steer people towards specialist treatment, which can reduce health-care utilization and costs to the public sector and produce substantial individual health and social benefits. Alcohol misuse is associated with other lifestyle problems, which are amenable to intervention. It has been suggested that the development of a healthy or balanced lifestyle is potentially beneficial for reducing or abstaining from alcohol use, and relapse prevention. The aim of the study is to test whether or not the offer of a choice of health-related lifestyle interventions is more acceptable, and therefore able to engage more problem drinkers in treatment, than an alcohol-focused intervention. This is a pragmatic, randomized, controlled, open pilot study in a UK general hospital setting with concurrent economic evaluation and a qualitative component. Potential participants are those admitted to hospital with a diagnosis likely to be responsive to addiction interventions who score equal to or more than 16 on the Alcohol Use Disorders Identification Test (AUDIT). The main purpose of this pilot study is to evaluate the acceptability of two sorts of interventions (healthy living related versus alcohol focused) to the participants and to assess the components and processes of the design. Qualitative research will be undertaken to explore acceptability and the impact of the approach, assessment, recruitment and intervention on trial participants and non-participants. The effectiveness of the two treatments will be compared at 6 months using AUDIT scores as the primary outcome measure. There will be additional economic, qualitative and secondary outcome measurements. Development of the study was a

  16. Early Child Social-Emotional Problems and Child Obesity: Exploring the Protective Role of a Primary Care-Based General Parenting Intervention.

    Science.gov (United States)

    Gross, Rachel S; Briggs, Rahil D; Hershberg, Rebecca S; Silver, Ellen J; Velazco, Nerissa K; Hauser, Nicole R; Racine, Andrew D

    2015-10-01

    To determine whether early social-emotional problems are associated with child feeding practices, maternal-child feeding styles, and child obesity at age 5 years, in the context of a primary care-based brief general parenting intervention led by an integrated behavioral health specialist to offer developmental monitoring, on-site intervention, and/or referrals. A retrospective cohort study was conducted of mothers with 5-year-old children previously screened using the Ages and Stages Questionnaires: Social-Emotional (ASQ:SE) during the first 3 years of life. ASQ:SE scores were dichotomized "not at risk" versus "at risk." "At risk" subjects were further classified as participating or not participating in the intervention. Regression analyses were performed to determine relationships between social-emotional problems and feeding practices, feeding styles, and weight status at age 5 years based on participation, controlling for potential confounders and using "not at risk" as a reference group. Compared with children "not at risk," children "at risk-no participation" were more likely to be obese at age 5 years (adjusted odds ratio, 3.12; 95% confidence interval, 1.03 to 9.45). Their mothers were less likely to exhibit restriction and limit setting and more likely to pressure to eat than mothers in the "not at risk" group. Children "at risk-participation" did not demonstrate differences in weight status compared with children "not at risk." Early social-emotional problems, unmitigated by intervention, were related to several feeding styles and to obesity at age 5 years. Further study is needed to understand how a general parenting intervention may be protective against obesity.

  17. Fictitious domain methods for elliptic problems with general boundary conditions with an application to the numerical simulation of two phase flows

    International Nuclear Information System (INIS)

    Ramiere, I.

    2006-09-01

    This work is dedicated to the introduction of two original fictitious domain methods for the resolution of elliptic problems (mainly convection-diffusion problems) with general and eventually mixed boundary conditions: Dirichlet, Robin or Neumann. The originality lies in the approximation of the immersed boundary by an approximate interface derived from the fictitious domain Cartesian mesh, which is generally not boundary-fitted to the physical domain. The same generic numerical scheme is used to impose the embedded boundary conditions. Hence, these methods require neither a surface mesh of the immersed boundary nor the local modification of the numerical scheme. We study two modelling of the immersed boundary. In the first one, called spread interface, the approximate immersed boundary is the union of the cells crossed by the physical immersed boundary. In the second one, called thin interface, the approximate immersed boundary lies on sides of mesh cells. Additional algebraic transmission conditions linking both flux and solution jumps through the thin approximate interface are introduced. The fictitious problem to solve as well as the treatment of the embedded boundary conditions are detailed for the two methods. A Q1 finite element scheme is implemented for the numerical validation of the spread interface approach while a new cell-centered finite volume scheme is derived for the thin interface approach with immersed jumps. Each method is then combined to multilevel local mesh refinement algorithms (with solution or flux residual) to increase the precision of the solution in the vicinity of the immersed interface. A convergence analysis of a Q1 finite element method with non-boundary fitted meshes is also presented. This study proves the convergence rates of the present methods. Among the various industrial applications, the simulation on a model of heat exchanger in french nuclear power plants enables us to appreciate the performances of the fictitious domain

  18. An Optimizing Space Data-Communications Scheduling Method and Algorithm with Interference Mitigation, Generalized for a Broad Class of Optimization Problems

    Science.gov (United States)

    Rash, James

    2014-01-01

    NASA's space data-communications infrastructure-the Space Network and the Ground Network-provide scheduled (as well as some limited types of unscheduled) data-communications services to user spacecraft. The Space Network operates several orbiting geostationary platforms (the Tracking and Data Relay Satellite System (TDRSS)), each with its own servicedelivery antennas onboard. The Ground Network operates service-delivery antennas at ground stations located around the world. Together, these networks enable data transfer between user spacecraft and their mission control centers on Earth. Scheduling data-communications events for spacecraft that use the NASA communications infrastructure-the relay satellites and the ground stations-can be accomplished today with software having an operational heritage dating from the 1980s or earlier. An implementation of the scheduling methods and algorithms disclosed and formally specified herein will produce globally optimized schedules with not only optimized service delivery by the space data-communications infrastructure but also optimized satisfaction of all user requirements and prescribed constraints, including radio frequency interference (RFI) constraints. Evolutionary algorithms, a class of probabilistic strategies for searching large solution spaces, is the essential technology invoked and exploited in this disclosure. Also disclosed are secondary methods and algorithms for optimizing the execution efficiency of the schedule-generation algorithms themselves. The scheduling methods and algorithms as presented are adaptable to accommodate the complexity of scheduling the civilian and/or military data-communications infrastructure within the expected range of future users and space- or ground-based service-delivery assets. Finally, the problem itself, and the methods and algorithms, are generalized and specified formally. The generalized methods and algorithms are applicable to a very broad class of combinatorial

  19. Series: The research agenda for general practice/family medicine and primary health care in Europe. Part 4. Results: specific problem solving skills.

    Science.gov (United States)

    Hummers-Pradier, Eva; Beyer, Martin; Chevallier, Patrick; Eilat-Tsanani, Sophia; Lionis, Christos; Peremans, Lieve; Petek, Davorina; Rurik, Imre; Soler, Jean Karl; Stoffers, Henri Ejh; Topsever, Pinar; Ungan, Mehmet; van Royen, Paul

    2010-09-01

    The 'Research Agenda for General Practice/Family Medicine and Primary Health Care in Europe' summarizes the evidence relating to the core competencies and characteristics of the Wonca Europe definition of GP/FM, and its implications for general practitioners/family doctors, researchers and policy makers. The European Journal of General Practice publishes a series of articles based on this document. The previous articles presented background, objectives, and methodology, as well results on 'primary care management' and 'community orientation' and the person-related core competencies of GP/FM. This article reflects on the general practitioner's 'specific problem solving skills'. These include decision making on diagnosis and therapy of specific diseases, accounting for the properties of primary care, but also research questions related to quality management and resource use, shared decision making, or professional education and development. Clinical research covers most specific diseases, but often lacks pragmatism and primary care relevance. Quality management is a stronghold of GP/FM research. Educational interventions can be effective when well designed for a specific setting and situation. However, their message that 'usual care' by general practitioners is insufficient may be problematic. GP and their patients need more research into diagnostic reasoning with a step-wise approach to increase predictive values in a setting characterized by uncertainty and low prevalence of specific diseases. Pragmatic comparative effectiveness studies of new and established drugs or non-pharmaceutical therapy are needed. Multi-morbidity and complexity should be addressed. Studies on therapy, communication strategies and educational interventions should consider impact on health and sustainability of effects.

  20. Shift Work and Related Health Problems among Medical and Diagnostic Staff of the General Teaching Hospitals Affiliated to Shiraz University of Medical Sciences, 2012

    Directory of Open Access Journals (Sweden)

    Zahra Sajjadnia

    2015-07-01

    Full Text Available Introduction:Today, shift work is considered as a necessity in many jobs and for some 24-hour services the use of shift-work is growing. However, shift work can lead to physiological and psycho-social problems for shift workers. This study aimed to determine the effects of shift work on the associated health problems, together with the demographic and job characteristics underlying the problems, among the medical and diagnostic staff of the general teaching hospitals affiliated to Shiraz University of Medical Sciences in 2012. Method:This study was an applied, cross-sectional and descriptive-analytical one. The study employed a sample of 205 employees from the medical and diagnostic staff using stratified sampling proportional to the size and simple random sampling methods. Data were collected using the Survey of Shift workers (SOS questionnaire, validity and reliability of which have already been confirmed. Finally, the collected data were analyzed using SPSS 16.0 software through ANOVA, Chi-square, Independent-Samples T-Test, as well as Pearson Correlation Coefficient. A P<0.05 was considered statistically significant. Results: The results showed that among the demographic and job characteristics studied, the individual, family and social problems had significant associations with work schedules, shift work and job satisfaction. In addition, there were significant associations between musculoskeletal disorders and the satisfaction of shift work; cardiovascular disorders and marital status and occupation; digestive disorders and the work schedules; sleep disorders and the satisfaction of shift work; musculoskeletal disorders, cardiovascular disorders and sleep disorders and age, job experience and shift work experience. And finally, there were significant associations among sleep disorders and age, job experience and the shift work experience. Conclusion: Based on the findings of this study, demographic characteristics such as age, marital

  1. Self-Reported Halitosis in relation to Oral Hygiene Practices, Oral Health Status, General Health Problems, and Multifactorial Characteristics among Workers in Ilala and Temeke Municipals, Tanzania.

    Science.gov (United States)

    Kayombo, C M; Mumghamba, E G

    2017-01-01

    Aim. To assess self-reported halitosis, oral hygiene practices, oral health conditions, general health problems, sociodemographic factors, and behavioural and psychological characteristics among workers in Ilala and Temeke municipals. Materials and Methods. This was a cross-sectional descriptive study. Four hundred workers were recruited using a self-administered structured questionnaire. Results. Self-reported tooth brushing practice was 100%, tongue cleaning 58.5%, dental flossing 4.3%, gum bleeding on tooth brushing 79.3%, presence of hard deposits on teeth 32%, mobile teeth 15.3%, and self-reported halitosis (SRH) 48.5%. Tea users were 95%, coffee users 75.8%, smokers 21%, and alcohol consumers 47%. The SRH was significantly associated with bleeding gums, hard deposits, and mobile and malaligned teeth. Tongue cleaning and regular change of toothbrush were associated with low prevalence of SRH ( P promotion are recommended.

  2. The promise and problems of non-physician practitioners in general surgery education: Results of a multi-center, mixed-methods study of faculty.

    Science.gov (United States)

    Coverdill, James E; Shelton, Jeff Scott; Alseidi, Adnan; Borgstrom, David C; Dent, Daniel L; Dumire, Russell; Fryer, Jonathan; Hartranft, Thomas H; Holsten, Steven B; Nelson, M Timothy; Shabahang, Mohsen M; Sherman, Stanley R; Termuhlen, Paula M; Woods, Randy J; Mellinger, John D

    2018-02-01

    Nurse Practitioners and Physician Assistants - called non-physician practitioners or NPPs - are common, but little is known about their educational promise and problems. General surgery faculty in 13 residency programs were surveyed (N = 279 with a 71% response rate) and interviewed (N = 43) about experiences with NPPs. The survey documents overall patterns and differences by program type and primary service; interviews point to deeper rationales and concerns. NPPs reduce faculty and resident workloads and teach residents. NPPs also reduce resident exposure to educationally valuable activities, and faculty sometimes round, make decisions, and operate with NPPs instead of residents. Interviews indicate that NPPs can overly reduce resident involvement in patient care, diminish resident responsibility and decision making, disrupt team dynamics, and compete for procedures. NPPs both enhance and hinder surgical education and highlight the need to more clearly articulate learning outcomes for residents and activities necessary to achieve those outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Comparative demography of an epiphytic lichen: support for general life history patterns and solutions to common problems in demographic parameter estimation.

    Science.gov (United States)

    Shriver, Robert K; Cutler, Kerry; Doak, Daniel F

    2012-09-01

    Lichens are major components in many terrestrial ecosystems, yet their population ecology is at best only poorly understood. Few studies have fully quantified the life history or demographic patterns of any lichen, with particularly little attention to epiphytic species. We conducted a 6-year demographic study of Vulpicida pinastri, an epiphytic foliose lichen, in south-central Alaska. After testing multiple size-structured functions to describe patterns in each V. pinastri demographic rate, we used the resulting estimates to construct a stochastic demographic model for the species. This model development led us to propose solutions to two general problems in construction of demographic models for many taxa: how to simply but accurately characterize highly skewed growth rates, and how to estimate recruitment rates that are exceptionally difficult to directly observe. Our results show that V. pinastri has rapid and variable growth and, for small individuals, low and variable survival, but that these traits are coupled with considerable longevity (e.g., >50 years mean future life span for a 4-cm(2) thallus) and little deviation of the stochastic population growth rate from the deterministic expectation. Comparisons of the demographic patterns we found with those of other lichen studies suggest that their relatively simple architecture may allow clearer generalities about growth patterns for lichens than for other taxa, and that the expected pattern of faster growth rates for epiphytic species is substantiated.

  4. The diagnosis, prevalence and outcome of delirium in a cohort of older people with mental health problems on general hospital wards.

    Science.gov (United States)

    Whittamore, Kathy H; Goldberg, Sarah E; Gladman, John R F; Bradshaw, Lucy E; Jones, Rob G; Harwood, Rowan H

    2014-01-01

    This paper aimed to measure the prevalence and outcomes of delirium for patients over 70 admitted to a general hospital for acute medical care and to assess the validity of the Delirium Rating Scale-Revised-98 (DRS-R-98) in this setting. Prospective study in a British acute general hospital providing sole emergency medical services for its locality. We screened consecutive patients over 70 with an unplanned emergency hospital admission and recruited a cohort of 249 patients likely to have mental health problems. They were assessed for health status at baseline and followed over 6 months. A sub-sample of 93 participants was assessed clinically for delirium. 27% (95% confidence interval (CI) 23-31) of all older medical patients admitted to hospital had DRS-diagnosed delirium, and 41% (95% CI 37-45) had dementia (including 19% with co-morbid delirium and dementia). Compared with clinician diagnosis, DRS-R-98 sensitivity was at least 0.75, specificity 0.71. Compared with reversible cognitive impairment, sensitivity was at least 0.50, specificity 0.67. DRS-diagnosed delirium was associated with cognitive impairment, mood, behavioural and psychological symptoms, activities of daily living, and number of drugs prescribed, supporting construct validity. Of those with DRS-diagnosed delirium, 37% died within 6 months (relative risk 1.4, 95% CI 0.97-2.2), 43% had reversible cognitive impairment, but only 25% had clinically important recovery in activities of daily living. Behavioural and psychological symptoms were common and mostly resolved, but new symptoms frequently developed. Delirium is common. Some, but not all, features are reversible. DRS-R-98 has reasonable validity in populations where co-morbid dementia is prevalent. Copyright © 2013 John Wiley & Sons, Ltd.

  5. Self-Reported Halitosis in relation to Oral Hygiene Practices, Oral Health Status, General Health Problems, and Multifactorial Characteristics among Workers in Ilala and Temeke Municipals, Tanzania

    Directory of Open Access Journals (Sweden)

    C. M. Kayombo

    2017-01-01

    Full Text Available Aim. To assess self-reported halitosis, oral hygiene practices, oral health conditions, general health problems, sociodemographic factors, and behavioural and psychological characteristics among workers in Ilala and Temeke municipals. Materials and Methods. This was a cross-sectional descriptive study. Four hundred workers were recruited using a self-administered structured questionnaire. Results. Self-reported tooth brushing practice was 100%, tongue cleaning 58.5%, dental flossing 4.3%, gum bleeding on tooth brushing 79.3%, presence of hard deposits on teeth 32%, mobile teeth 15.3%, and self-reported halitosis (SRH 48.5%. Tea users were 95%, coffee users 75.8%, smokers 21%, and alcohol consumers 47%. The SRH was significantly associated with bleeding gums, hard deposits, and mobile and malaligned teeth. Tongue cleaning and regular change of toothbrush were associated with low prevalence of SRH (P<0.001. Higher occurrence of SRH was significantly related to low education and smoking. Conclusion. Self-reported halitosis was prevalent among workers and was significantly associated with bleeding gums, hard dental deposits, mobile teeth, and smoking. All participants brushed their teeth and cleaned the tongue regularly but use of dental floss was extremely low. Oral health education and health promotion are recommended.

  6. Fictitious domain methods for elliptic problems with general boundary conditions with an application to the numerical simulation of two phase flows; Methodes de domaine fictif pour des problemes elliptiques avec conditions aux limites generales en vue de la simulation numerique d'ecoulements diphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Ramiere, I

    2006-09-15

    This work is dedicated to the introduction of two original fictitious domain methods for the resolution of elliptic problems (mainly convection-diffusion problems) with general and eventually mixed boundary conditions: Dirichlet, Robin or Neumann. The originality lies in the approximation of the immersed boundary by an approximate interface derived from the fictitious domain Cartesian mesh, which is generally not boundary-fitted to the physical domain. The same generic numerical scheme is used to impose the embedded boundary conditions. Hence, these methods require neither a surface mesh of the immersed boundary nor the local modification of the numerical scheme. We study two modelling of the immersed boundary. In the first one, called spread interface, the approximate immersed boundary is the union of the cells crossed by the physical immersed boundary. In the second one, called thin interface, the approximate immersed boundary lies on sides of mesh cells. Additional algebraic transmission conditions linking both flux and solution jumps through the thin approximate interface are introduced. The fictitious problem to solve as well as the treatment of the embedded boundary conditions are detailed for the two methods. A Q1 finite element scheme is implemented for the numerical validation of the spread interface approach while a new cell-centered finite volume scheme is derived for the thin interface approach with immersed jumps. Each method is then combined to multilevel local mesh refinement algorithms (with solution or flux residual) to increase the precision of the solution in the vicinity of the immersed interface. A convergence analysis of a Q1 finite element method with non-boundary fitted meshes is also presented. This study proves the convergence rates of the present methods. Among the various industrial applications, the simulation on a model of heat exchanger in french nuclear power plants enables us to appreciate the performances of the fictitious domain

  7. [Population problem, comprehension problem].

    Science.gov (United States)

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

  8. Inverse problems of geophysics

    International Nuclear Information System (INIS)

    Yanovskaya, T.B.

    2003-07-01

    This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

  9. Advanced cancer patients' self-assessed physical and emotional problems on admission and discharge from hospital general ward - a questionnaire study

    DEFF Research Database (Denmark)

    Sølver, Lisbeth; Østergaard, Birte; Rydahl Hansen, Susan

    2012-01-01

    of 'clinically relevant problems' on admission was 5 (SD 2) and on discharge 4 (SD 2). A Wilcoxon signed rank test showed significant change in mean score for six out of nine problem areas, but the majority of the patients did not move to the lower intensity category. The highest concurrence was between patient...

  10. Using routinely collected data to evaluate a leaflet campaign to increase the presentation of people with memory problems to general practice: a locality based controlled study

    Directory of Open Access Journals (Sweden)

    Tom Chan

    2010-09-01

    Conclusions During a leaflet campaign the recording and management ofmemory problems increased. However, there was greater improvement in the control locality. This study demonstrates the importance of including a control group and the strengths of routine primary care data.

  11. Approaching the Brachistochrone Using Inclined Planes--Striving for Shortest or Equal Travelling Times

    Science.gov (United States)

    Theilmann, Florian

    2017-01-01

    The classical "brachistochrone" problem asks for the path on which a mobile point M just driven by its own gravity will travel in the shortest possible time between two given points "A" and "B." The resulting curve, the cycloid, will also be the "tautochrone" curve, i.e. the travelling time of the mobile…

  12. Striking trends in the incidence of health problems in the Netherlands (2002-05): findings from a new method for record linkage in general practice.

    NARCIS (Netherlands)

    Biermans, M.C.J.; Spreeuwenberg, P.; Verheij, R.A.; Bakker, D.H. de; Vries Robbé, P.F. de; Zielhuis, G.A.

    2009-01-01

    BACKGROUND: This study aimed to detect striking trends based on a new strategy for monitoring public health. METHODS: We used data over 4 years from electronic medical records of a large, nationally representative network of general practices. Episodes were either directly recorded by general

  13. Striking trends in the incidence of health problems in The Netherlands (2002-05). Findings from a new strategy for surveillance in general practice.

    NARCIS (Netherlands)

    Biermans, M.C.J.; Spreeuwenberg, P.; Verheij, R.A.; Bakker, D.H. de; Vries Robbe, P.F. de; Zielhuis, G.A.

    2009-01-01

    BACKGROUND: This study aimed to detect striking trends based on a new strategy for monitoring public health. METHODS: We used data over 4 years from electronic medical records of a large, nationally representative network of general practices. Episodes were either directly recorded by general

  14. Top man: Mathematician, geographer, vice chancellor , Sir Alan Wilson the new director general of higher education at the DfES, has a reputation for solving complicated problems. He talks to Jim Kelly

    CERN Multimedia

    Kelly, J

    2003-01-01

    "Sir Alan Wilson, vice-chancellor of Leeds University, has made a career out of solving big problems. This week he landed himself one of the biggest. Appointed the government's first ever director general of higher education, he becomes responsible for advising Charles Clarke at a pivotal moment in the history of the sector" (1 page).

  15. General surgical complications associated with the use of long-term mechanical circulatory support devices: are we 'under-reporting' problems?

    Science.gov (United States)

    Tchantchaleishvili, Vakhtang; Umakanthan, Ramanan; Karp, Seth; Stulak, John M; Keebler, Mary E; Maltais, Simon

    2013-05-01

    Multiple complications are associated with use of ventricular assist devices (VADs). Cardiac-related complications and infections are most frequently reported. VADs, however, can also lead to a number of general surgical complications equally significant in terms of morbidity and mortality. The authors performed a systematic literature search to review current data that specifically relate general surgical complications to patients who undergo left VAD implantation. The review provides a relatively clear understanding of the spectrum of general surgical complications and shows that they contribute significantly to morbidity and mortality in these patients.

  16. Generalization of Spectral Green's Function nodal method for slab-geometry fixed-source adjoint transport problems in S{sub N} formulation

    Energy Technology Data Exchange (ETDEWEB)

    Curbelo, Jesus P.; Silva, Odair P. da; Barros, Ricardo C. [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico. Programa de Pos-graduacao em Modelagem Computacional; Garcia, Carlos R., E-mail: cgh@instec.cu [Departamento de Ingenieria Nuclear, Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba)

    2017-07-01

    Presented here is the application of the adjoint technique for solving source-detector discrete ordinates (S{sub N}) transport problems by using a spectral nodal method. For slab-geometry adjoint S-N model, the adjoint spectral Green's function method (SGF{sup †}) is extended to multigroup problems considering arbitrary L'th-order of scattering anisotropy, and the possibility of non-zero prescribed boundary conditions for the forward S{sub N} transport problems. The SGF{sup †} method converges numerical solutions that are completely free from spatial truncation errors. In order to generate numerical solutions of the SGF{sup †} equations, we use the partial adjoint one-node block inversion (NBI) iterative scheme. Partial adjoint NBI scheme uses the most recent estimates for the node-edge adjoint angular Fluxes in the outgoing directions of a given discretization node, to solve the resulting adjoint SN problem in that node for all the adjoint angular fluxes in the incoming directions, which constitute the outgoing adjoint angular fluxes for the adjacent node in the sweeping directions. Numerical results are given to illustrate the present spectral nodal method features and some advantages of using the adjoint technique in source-detector problems. author)

  17. Generalization of Spectral Green's Function nodal method for slab-geometry fixed-source adjoint transport problems in SN formulation

    International Nuclear Information System (INIS)

    Curbelo, Jesus P.; Silva, Odair P. da; Barros, Ricardo C.

    2017-01-01

    Presented here is the application of the adjoint technique for solving source{detector discrete ordinates (S N ) transport problems by using a spectral nodal method. For slab-geometry adjoint S-N model, the adjoint spectral Green's function method (SGF † ) is extended to multigroup problems considering arbitrary L'th-order of scattering anisotropy, and the possibility of non{zero prescribed boundary conditions for the forward S N transport problems. The SGF † method converges numerical solutions that are completely free from spatial truncation errors. In order to generate numerical solutions of the SGF † equations, we use the partial adjoint one{node block inversion (NBI) iterative scheme. Partial adjoint NBI scheme uses the most recent estimates for the node-edge adjoint angular Fluxes in the outgoing directions of a given discretization node, to solve the resulting adjoint SN problem in that node for all the adjoint angular fluxes in the incoming directions, which constitute the outgoing adjoint angular fluxes for the adjacent node in the sweeping directions. Numerical results are given to illustrate the present spectral nodal method features and some advantages of using the adjoint technique in source-detector problems. author)

  18. Problems of development and putting into education process an electronic textbook on special discipline 'General theory and construction of heat-and-power engineering facilities'

    International Nuclear Information System (INIS)

    Karitskaya, S.G.; Ruzanov, K.A.; Davletov, V.S.

    2005-01-01

    The results of work of making the electronic textbook of special discipline ('General theory and construction of heat-and-power engineering facilities' are brought. The principles and requirements, presented towards literature of such type, are outlined. (author)

  19. Combined effect of mental disorder and low social support on care service use for mental health problems in the Dutch general population

    NARCIS (Netherlands)

    Ten Have, M; Vollebergh, W; Bijl, R; Ormel, J

    Background. People with a mental disorder have high rates of service utilization for emotional or addiction problems. Little is known about the role of functional impairments and low social support in such service use. This article investigates: (1) whether the presence of multiple functional

  20. Combined effect of mental disorder and low social support on care service use for mental health problems in de Dutch general population

    NARCIS (Netherlands)

    Have, M.L. ten; Vollebergh, W.A.M.; Bijl, R.V.; Ormel, J.

    2002-01-01

    Background. People with a mental disorder have high rates of service utilization for emotional or addiction problems. Little is known about the role of functional impairments and low social support in such service use. This article investigates: (1) whether the presence of multiple functional

  1. A New Result Concerning the Solvability of a Class of General Systems of Variational Equations with Nonmonotone Operators: Applications to Dirichlet and Neumann Nonlinear Problems

    Directory of Open Access Journals (Sweden)

    Luisa Toscano

    2016-01-01

    Full Text Available A new result of solvability for a wide class of systems of variational equations depending on parameters and governed by nonmonotone operators is found in a Banach real and reflexive space with applications to Dirichlet and Neumann problems related to nonlinear elliptic systems.

  2. Factors influencing the type of health problems presented by women in general practice: differences between women's health care and regular health care.

    NARCIS (Netherlands)

    Brink-Muinen, A. van den; Bensing, J.M.

    1996-01-01

    Objective: Differences between health problems presented by women (aged 20-45) to female "women's health care" doctors and both female and male regular health care doctors were investigated. This article explores the relationship of patients' roles (worker, partner, or parent) and the type of health

  3. Application of a General Risk Management Model to Portfolio Optimization Problems with Elliptical Distributed Returns for Risk Neutral and Risk Averse Decision Makers

    NARCIS (Netherlands)

    B. Kaynar; S.I. Birbil (Ilker); J.B.G. Frenk (Hans)

    2007-01-01

    textabstractIn this paper portfolio problems with linear loss functions and multivariate elliptical distributed returns are studied. We consider two risk measures, Value-at-Risk and Conditional-Value-at-Risk, and two types of decision makers, risk neutral and risk averse. For Value-at-Risk, we show

  4. HPA-axis activity and externalizing behavior problems in early adolescents from the general population : the role of comorbidity and gender The TRAILS study

    NARCIS (Netherlands)

    Marsman, Rianne; Swinkels, Sophie H. N.; Rosmalen, Judith G. M.; Oldehinkel, Albertine J.; Ormel, Johan; Buitelaar, Jan K.

    Contradictory findings on the relationship between hypothalamus-pituitary-adrenal (HPA)-axis activity and externalizing behavior problems could be due to studies not accounting for issues of comorbidity and gender. In a population-based cohort of 1768 (10- to 12-year-old) early adolescents, we used

  5. General solutions to multiple testing problems. Translation of "Sonnemann, E. (1982). Allgemeine Lösungen multipler Test probleme. EDV in Medizin und Biologie 13(4), 120-128".

    Science.gov (United States)

    Sonnemann, Eckart

    2008-10-01

    The introduction of sequentially rejective multiple test procedures (Einot and Gabriel, 1975; Naik, 1975; Holm, 1977; Holm, 1979) has caused considerable progress in the theory of multiple comparisons. Emphasizing the closure of multiple tests we give a survey of the general theory and its recent results in applications. Some new applications are given including a discussion of the connection with the theory of confidence regions.

  6. Pathways to care and psychological problems of general practice patients in a "gate keeper" and an "open access" health care system - A comparison of Germany and the Netherlands

    NARCIS (Netherlands)

    Linden, M; Gothe, H; Ormel, J

    2003-01-01

    Background The comparison of different health care systems is one way to give empirical evidence to health care reform and policy. The differences between health care systems in which general practitioners serve as gate keepers in comparison to systems in which patients are free to contact every

  7. Psychometric properties of a Dutch version of the Maslach Burnout Inventory General Survey (UBOS) in individuals with work-related problems

    NARCIS (Netherlands)

    Roelofs, J.; Verbraak, M.J.P.M.; Keijsers, G.P.J.; Bruin, M.B.N. de; Schmidt, A.J.M.

    2005-01-01

    Psychometric properties of the Dutch version of the Maslach Burnout Inventory General Survey, the MBI-DV, were examined in individuals with and without clinical burnout. The factor structure, the utility of the MBI-DV as a screening instrument in addition to a clinical interview for diagnosing

  8. Predictive value of general movements' quality in low-risk infants for minor neurological dysfunction and behavioural problems at preschool age

    NARCIS (Netherlands)

    Bennema, Anne N; Schendelaar, Pamela; Seggers, Jorien; Haadsma, Maaike L; Heineman, Maas Jan; Hadders-Algra, Mijna

    Background: General movement (GM) assessment is a well-established tool to predict cerebral palsy in high-risk infants. Little is known on the predictive value of GM assessment in low-risk populations. Aims: To assess the predictive value of GM quality in early infancy for the development of the

  9. General problems arising from the analogical resolution of the kinetic equations of nuclear reactors (1961); Problemes generaux poses par la resolution analogique des equations cinetiques des reacteurs nucleaires (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Caillet, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The author reviews precisely the analogical techniques used for the resolution of the kinetic equations of nuclear reactors. Prior to this, he recalls the reasons which oblige physicians and engineers, even today, to use electronic machines in this domain. The author then considers the technological problems posed by the range of values which the various nuclear parameters adopt. In each case, he shows that a compromise is possible allowing an optimum precision. He compares the results to those obtained by arithmetic calculation and uses the examples chosen in a critical analysis of the present possibilities of the two methods of calculation. (author) [French] L'auteur cherche a faire un point aussi exact que possible des techniques analogiques utilisees pour resoudre les equations cinetiques des reacteurs nucleaires. Il rappelle auparavant les raisons pour lesquelles physiciens et ingenieurs sont obliges, encore aujourd'hui, de faire appel aux machines electroniques dans ce domaine. Puis il etudie les problemes technologiques que souleve le champ des valeurs prises par les differents parametres nucleaires. Dans chacun des cas, il montre l'existence d'un compromis qui permet d'atteindre une precision optimum. Il compare les resultats obtenus a ceux provenant de calculateurs arithmetiques et profite des exemples choisis pour faire une analyse critique des possibilites actuelles offertes par les deux modes de calcul. (auteur)

  10. Handling of computational in vitro/in vivo correlation problems by Microsoft Excel: IV. Generalized matrix analysis of linear compartment systems.

    Science.gov (United States)

    Langenbucher, Frieder

    2005-01-01

    A linear system comprising n compartments is completely defined by the rate constants between any of the compartments and the initial condition in which compartment(s) the drug is present at the beginning. The generalized solution is the time profiles of drug amount in each compartment, described by polyexponential equations. Based on standard matrix operations, an Excel worksheet computes the rate constants and the coefficients, finally the full time profiles for a specified range of time values.

  11. A General Discussion of Problems Related to the Determination of Concrete Armour Unit Stresses Including Specific Results related to Static and Dynamic Stresses in Dolosse

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1989-01-01

    Recent breakwater failures revealed the shortcomings of the traditional design procedures for concrete armour units. This paper deals with one of them, which can be expressed as the "lack of balance between the hydraulic stability of the armour layer and the mechanical strength or integrity...... of the units". This problem is related mainly to the slender types of armour units. The paper discusses the various types of loads, and the practical determination of the wave and gravity induced loads and stresses, especially the model test technique and its restrictions. Examples related to Dolosse...

  12. [Physician's anxiety and physician's elegance. Problems in dealing with cost reduction, education of general practitioners and optimal size of practice networks in a cross-national comparison].

    Science.gov (United States)

    Behrens, J

    2000-03-01

    The key reason for physicians networking in managed care is to get a better coping with uncertainty on action (treatment) decisions. The second reason for networking in managed care are financial benefits grounds. But this reason is very ambivalent. Three different action problems (role conflicts) in managed care network are to solved, which was also in single practices. In the lecture the decision strategies and decision resources has been compared. Observations are done using expert interviews, patient interviews and analysis of documents in USA, Germany and Switzerland. The first problem is the choosing of a cost reduction strategy which is not reducing the effectiveness. Such "ugly" solution strategies like exclusion of "expensive" patients and a rationing of necessary medical services in a kind of McDonalds network of physicians will fail the target. The optimost way is a saving of all unnecessary medical even injourious performances. The chosen cost reduction strategy is not real visible from outside but in fact limited cognizable and controllable. Evidence based health care can be a resource of treatment decisions and could train such decisions but it will not substitute these decisions. The second problem is the making of real family practitioners as gatekeepers. Knowledge about the care system is still not making a real family practitioner, even if this is the minimum condition of their work. Also contractual relationships between insurance and doctor as a gatekeeper or financial incentives for patients are still making not a real family practitioner as a gatekpeeper. Only throughout the trust of patients supported by second opinions is making the real family practitioner as a gatekeeper. "Doctor hopping" could be the reaction by scarcity of trustworthy family practitioners as gatekeepers. The third problem is the choosing of the optimal scale of a network due to the very different optimal size of networks regarding the requirement of risk spreeds, of the

  13. An evaluation of the effectiveness of psychological therapy in reducing general psychological distress for adults with autism spectrum conditions and comorbid mental health problems.

    Science.gov (United States)

    Blainey, Sarah H; Rumball, Freya; Mercer, Louise; Evans, Lauren Jayne; Beck, Alison

    2017-11-01

    To investigate the effectiveness of psychological therapy in reducing psychological distress for adults with autism spectrum conditions (ASC) and co-morbid mental health conditions in routine clinical practice. To explore the effect of individual characteristics and service factors on change in general distress. In a specialist psychological therapies service for adults with ASC, the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) self-report questionnaire of psychological distress is completed by clients at start and end of therapy. Change over time and reliable and clinical change was assessed for 81 of a total of 122 clients (66.4%). Factors which may influence change over time were explored using available clinical information. Overall, there was a significant reduction in CORE-OM score during therapy with a small effect size. Most clients showed an improvement in psychological distress over therapy (75.4% improved, with 36.9% of these showing reliable changes). Significant and comparable reductions from pre-therapy to post-therapy were seen across the sample, showing that individual differences did not mediate therapy effectiveness. CORE-OM scores mediate the association between age of ASD diagnosis and hours of therapeutic input required, with greater age at diagnosis and higher distress associated with longer therapy duration. Our preliminary findings suggest that psychological therapy may be effective in reducing general distress for clients with ASC and co-morbid mental health conditions and should be routinely offered. Individuals who are diagnosed with ASD in adulthood are likely to require a longer course of therapy when their general distress scores are high. Copyright © 2017 John Wiley & Sons, Ltd.

  14. General topology

    CERN Document Server

    Willard, Stephen

    2004-01-01

    Among the best available reference introductions to general topology, this volume is appropriate for advanced undergraduate and beginning graduate students. Its treatment encompasses two broad areas of topology: ""continuous topology,"" represented by sections on convergence, compactness, metrization and complete metric spaces, uniform spaces, and function spaces; and ""geometric topology,"" covered by nine sections on connectivity properties, topological characterization theorems, and homotopy theory. Many standard spaces are introduced in the related problems that accompany each section (340

  15. Bacterial contamination of ultrasound probes in different radiological institutions before and after specific hygiene training: do we have a general hygienical problem?

    Science.gov (United States)

    Sartoretti, Thomas; Sartoretti, Elisabeth; Bucher, Candid; Doert, Aleksis; Binkert, Christoph; Hergan, Klaus; Meissnitzer, Matthias; Froehlich, Johannes; Kolokythas, Orpheus; Matoori, Simon; Orasch, Christina; Kos, Sebastian; Sartoretti-Schefer, Sabine; Gutzeit, Andreas

    2017-10-01

    Aim was to investigate hygienic conditions of ultrasound probes before and after hygiene training in radiology institutions in comparison to bacterial contamination in public places. In three radiology departments, bacterial contamination was evaluated using baseline agar plates for cultures taken from 36 ultrasound probes. Afterwards teams were trained by a hygiene service centre and 36 ultrasound probes were routinely disinfected with regular disinfecting wipes and then evaluated. In comparison, bacterial contamination in public places (bus poles, n = 11; toilet seats, n = 10) were analysed. Plates were routinely incubated and the number of colony forming units (CFU) analysed. Cultures taken from the probes showed a median of 53 CFU before and 0 CFU after training (p contamination of ultrasound probes prior to hygiene training proved to be high and showed higher bacterial load than toilets seats or bus poles. Radiologists should be aware that the lack of hygiene in the field of ultrasound diagnostics puts patients at risk of healthcare-associated infections. • Hospital-associated infections are a problem for patient care. • Hygiene training of staff prevents bacterial contamination of ultrasound probes. • Disinfection of ultrasound probes is an easy method to protect patients.

  16. Materials damaging and rupture - Volumes 1-2. General remarks, metallic materials. Non-metallic materials and biomaterials, assemblies and industrial problems

    International Nuclear Information System (INIS)

    Clavel, M.; Bompard, P.

    2009-01-01

    The rupture and damaging of materials and structures is almost always and unwanted events which may have catastrophic consequences. Even if the mechanical failure causes can often be analyzed using a thorough knowledge of materials behaviour, the forecasting and prevention of failures remain difficult. While the macroscopic mechanical behaviour is often the result of average effects at the structure or microstructure scale, the damage is very often the result of the combination of load peaks, of localization effects and of microstructure defects. This book, presented in two volumes, takes stock of the state-of-the-art of the knowledge gained in the understanding and modelling of rupture and damaging phenomena of materials and structure, mostly of metallic type. It gives an outline of the available knowledge for other classes of materials (ceramics, biomaterials, geo-materials..) and for different types of applications (aeronautics, nuclear industry). Finally, it examines the delicate problem, but very important in practice, of the behaviour of assemblies. Content: Vol.1 - physical mechanisms of materials damaging and rupture; rupture mechanics; cyclic plasticity and fatigue crack growth; fatigue crack propagation; environment-induced cracking; contacts and surfaces. Vol.2 - glasses and ceramics; natural environments: soils and rocks; mechanical behaviour of biological solid materials: the human bone; contribution of simulation to the understanding of rupture mechanisms; assemblies damaging and rupture; industrial cases (behaviour of PWR pressure vessel steels, and thermal and mechanical stresses in turbojet engines). (J.S.)

  17. El trabajador con problemas de salud mental: Pautas generales de detección, intervención y prevención Workers with mental health problems: General guidelines for detection, intervention and prevention

    Directory of Open Access Journals (Sweden)

    José Carlos Mingote Adán

    2011-01-01

    Full Text Available Numerosos estudios han demostrado las relaciones entre condiciones psicosociales del trabajo y la salud mental de los empleados, y especialmente cómo la combinación de bajo control percibido y altas demandas laborales predicen determinados problemas de salud mental. Trastornos mentales tales como los de ansiedad y depresión tienen un efecto muy negativo sobre la calidad de vida y la capacidad funcional en el trabajo. Además, la salud mental del trabajador puede afectar a la percepción de las características del trabajo. Como consecuencia, es fundamental diseñar trabajos saludables, programas de reducción de estrés para los empleados y para la reincorporación laboral de empleados con trastornos mentales. El objetivo del presente artículo es revisar las principales líneas de prevención, detección e intervención en las organizaciones, que pueden promover políticas saludables para la atención e integración de los trabajadores con trastorno mental.Numerous studies have demonstrated the relationship between psychosocial work conditions and the mental health of employees, and especially the combination of low perceived control and high labor demands predicts mental health problems. Mental health disorders such us anxiety or depression have a big detrimental effect on the individual's quality of life and the ability to function in the workplace. Mental health may also affect the perception of work characteristics. As a consequence, it is essential to design healthy jobs, stress reduction programs and return to work programs for employees with mental disorders. The aim of this paper is to review the main lines of prevention, detection and intervention in organizations that can promote healthy policies for the care and integration of workers with mental disorder.

  18. The problem of polysemy in the first thousand words of the General Service List: A corpus study of secondary chemistry texts

    Science.gov (United States)

    Clemmons, Karina

    Vocabulary in a second language is an indispensable building block of all comprehension (Folse, 2006; Nation, 2006). Teachers in content area classes such as science, math, and social studies frequently teach content specific vocabulary, but are not aware of the obstacles that can occur when students do not know the basic words. Word lists such as the General Service List (GSL) were created to assist students and teachers (West, 1953). The GSL does not adequately take into account the high level of polysemy of many common English words, nor has it been updated by genre to reflect specific content domains encountered by secondary science students in today's high stakes classes such as chemistry. This study examines how many words of the first 1000 words of the GSL occurred in the secondary chemistry textbooks sampled, how often the first 1000 words of the GSL were polysemous, and specifically which multiple meanings occurred. A discussion of results includes word tables that list multiple meanings present, example phrases that illustrate the context surrounding the target words, suggestions for a GSL that is genre specific to secondary chemistry textbooks and that is ranked by meaning as well as type, and implications for both vocabulary materials and classroom instruction for ELLs in secondary chemistry classes. Findings are essential to second language (L2) researchers, materials developers, publishers, and teachers.

  19. The Designated Convergence Rate Problems of Consensus or Flocking of Double-Integrator Agents With General Nonequal Velocity and Position Couplings: Further Results and Patterns of Convergence Rate Contours.

    Science.gov (United States)

    Li, Wei

    2017-05-01

    This paper considers the designated convergence rate (DCR) (or the designated convergence margin) problems of consensus or flocking of coupled double-integrator agents. The DCR problems are more valuable for systems design than just convergence or stability conditions. The system setting in this paper is general, i.e., the velocity coupling and position coupling (VCPC) between agents, respectively, are set to be general and nonequal (up to rescaling), together with distinct damping and stiffness gains for the VCPC, respectively. This paper has two primary contributions on consensus: 1) further necessary and sufficient conditions are established to guarantee the DCR problems of the system, which have enriched the previous results and 2) the patterns of the convergence rate contours for the DCR are characterized, in terms of the damping and stiffness gains, which are closely related to the characteristics of the spectra of the two Laplacian matrices of the VCPC. Additionally, this paper has a contribution on matrix theory, i.e., the sufficient conditions for the simultaneous upper-triangularization of two independent Laplacian matrices, particularly from an easily verifiable topological perspective on the corresponding digraphs of these Laplacian matrices.

  20. Duality in constrained location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1987-01-01

    The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated.......The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated....

  1. Environmental pollution: Measurable quantity or a problem of general risk acceptance?; Die stoffliche Belastung der Umwelt. Eine Systemgroesse oder eine Frage der allgemeinen Risikoakzeptanz?

    Energy Technology Data Exchange (ETDEWEB)

    Ballschmiter, K.

    2001-08-01

    Having different disciplines give different meanings to one same word is not unusual; using the word 'risk' in an environmental context has its specific importance. The classical definitions of 'risk' as the possibility of an adverse incident have been projected in the environmental and human health study areas. Risk-acceptance and risk-preference are general factors of the everyday life and even find a role in economics. However, their use as parameters in the field of environmental hazards should be avoided, or at least be defined as to their meaning. The environment is a complex system of mass fluxes and interdependencies that can be observed and described but not regulated in its global dimension. Technology assessment has here a specific task in defining precaution as the prevention of hazards as well as the 'repair in advance' of potential environmental risks of global dimensions. The globe as a whole and many of its parts cannot be subjected to 'end of the pipe' repair strategies. (orig.) [German] Das Phaenomen der unterschiedlichen Fuellung eines Begriffs in unterschiedlichen Disziplinen ist nicht neu; es wird aber besonders deutlich bei der Verwendung des Begriffes Risiko, wenn es um reale oder nur als moeglich angesehene Gefaehrdungen im Umweltbereich geht. Es werden die klassischen Definitionen eines Risikos, d.h. des moeglichen Eintritts eines Schadensereignisses, in ihrer Anwendung auf moegliche Schadensereignisse fuer Umwelt und Gesundheit gegenueber gestellt. Es wird die These vertreten, dass spezifische Formen der Risikoakzeptanz und Risikopraeferenz sehr wohl Faktoren der persoenlichen Lebensgestaltung sein koennen und auch in wirtschaftlichen Unternehmungen definierbare Groessen sind, dass sie aber fuer vom Menschen angestossene Veraenderungen in der Umwelt und hier insbesondere im Bereich der stofflichen Vorgaenge in den globalen Dimensionen nicht eingebracht werden koennen oder wenigstens eine sehr eigene

  2. Generalized Superconductivity. Generalized Levitation

    International Nuclear Information System (INIS)

    Ciobanu, B.; Agop, M.

    2004-01-01

    In the recent papers, the gravitational superconductivity is described. We introduce the concept of generalized superconductivity observing that any nongeodesic motion and, in particular, the motion in an electromagnetic field, can be transformed in a geodesic motion by a suitable choice of the connection. In the present paper, the gravitoelectromagnetic London equations have been obtained from the generalized Helmholtz vortex theorem using the generalized local equivalence principle. In this context, the gravitoelectromagnetic Meissner effect and, implicitly, the gravitoelectromagnetic levitation are given. (authors)

  3. Problemática jurídica en torno a los principios fundamentales del Sistema Multilateral de Comercio, en el Acuerdo General sobre el Comercio de Servicios, AGCS

    OpenAIRE

    Velasteguí Ayala, Ximena del Rocío

    2013-01-01

    El Acuerdo General sobre el Comercio de Servicios, AGCS, negociado en la Ronda de Uruguay, constituye en el primer acopio de normas internacionales en materia de comercio internacional de servicios, sector que evidencia un crecimiento acelerado en respuesta al rápido crecimiento de la economía mundial, producto de la evolución de las comunicaciones. Con el presente trabajo de investigación se pretende conocer la problemática jurídica que surge en torno a los principales princip...

  4. Elastic interaction of a crack with a microcrack array. I - Formulation of the problem and general form of the solution. II - Elastic solution for two crack configurations (piecewise constant and linear approximations)

    Science.gov (United States)

    Chudnovsky, A.; Dolgopolsky, A.; Kachanov, M.

    1987-01-01

    The elastic interactions of a two-dimensional configuration consisting of a crack with an array of microcracks located near the tip are studied. The general form of the solution is based on the potential representations and approximations of tractions on the microcracks by polynomials. In the second part, the technique is applied to two simple two-dimensional configurations involving one and two microcracks. The problems of stress shielding and stress amplification (the reduction or increase of the effective stress intensity factor due to the presence of microcracks) are discussed, and the refinements introduced by higher order polynomial approximations are illustrated.

  5. The Complete Problem Solver.

    Science.gov (United States)

    Hayes, John R.

    This book, designed for a college course on general problem-solving skills, focuses on skills that can be used by anyone in solving problems that occur in everyday life. Part I considers theory and practice: understanding problems, search, and protocol analysis. Part II discusses memory and knowledge acquisition: the structure of human memory,…

  6. General relativity

    International Nuclear Information System (INIS)

    Gourgoulhon, Eric

    2013-01-01

    The author proposes a course on general relativity. He first presents a geometrical framework by addressing, presenting and discussion the following notions: the relativistic space-time, the metric tensor, Universe lines, observers, principle of equivalence and geodesics. In the next part, he addresses gravitational fields with spherical symmetry: presentation of the Schwarzschild metrics, radial light geodesics, gravitational spectral shift (Einstein effect), orbitals of material objects, photon trajectories. The next parts address the Einstein equation, black holes, gravitational waves, and cosmological solutions. Appendices propose a discussion of the relationship between relativity and GPS, some problems and their solutions, and Sage codes

  7. Kerr generalized solution

    International Nuclear Information System (INIS)

    Papoyan, V.V.

    1989-01-01

    A Kerr generalized solution for a stationary axially-symmetric gravitational field of rotating self-gravitational objects is given. For solving the problem Einstein equations and their combinations are used. The particular cases: internal and external Schwarzschild solutions are considered. The external solution of the stationary problem is a Kerr solution generalization. 3 refs

  8. Balance Problems

    Science.gov (United States)

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

  9. A generalization of the convex Kakeya problem

    KAUST Repository

    Ahn, Heekap; Bae, Sangwon; Cheong, Otfried; Gudmundsson, Joachim; Tokuyama, Takeshi; Vigneron, Antoine E.

    2013-01-01

    segments. We also show that, if the goal is to minimize the perimeter of the region instead of its area, then placing the segments with their midpoint at the origin and taking their convex hull results in an optimal solution. Finally, we show that for any

  10. Discontinuities in an axisymmetric generalized thermoelastic problem

    Directory of Open Access Journals (Sweden)

    Moncef Aouadi

    2005-06-01

    Full Text Available This paper deals with discontinuities analysis in the temperature, displacement, and stress fields of a thick plate whose lower and upper surfaces are traction-free and subjected to a given axisymmetric temperature distribution. The analysis is carried out under three thermoelastic theories. Potential functions together with Laplace and Hankel transform techniques are used to derive the solution in the transformed domain. Exact expressions for the magnitude of discontinuities are computed by using an exact method developed by Boley (1962. It is found that there exist two coupled waves, one of which is elastic and the other is thermal, both propagating with finite speeds with exponential attenuation, and a third which is called shear wave, propagating with constant speed but with no exponential attenuation. The Hankel transforms are inverted analytically. The inversion of the Laplace transforms is carried out using the inversion formula of the transform together with Fourier expansion techniques. Numerical results are presented graphically along with a comparison of the three theories of thermoelasticity.

  11. General anesthesia for horses with specific problems

    International Nuclear Information System (INIS)

    Hodgson, D.S.; Dunlop, C.I.

    1990-01-01

    We have discussed anesthetic techniques, special considerations, and expected complications involved in anesthetizing horses for abdominal, orthopedic, and head and neck surgery, and myelography and have described expected physiologic dysfunction that may require changes in anesthetic technique or supportive measures. The objective is high-quality patient care and reduction in anesthesia-related morbidity and death

  12. Linear Programming Problems for Generalized Uncertainty

    Science.gov (United States)

    Thipwiwatpotjana, Phantipa

    2010-01-01

    Uncertainty occurs when there is more than one realization that can represent an information. This dissertation concerns merely discrete realizations of an uncertainty. Different interpretations of an uncertainty and their relationships are addressed when the uncertainty is not a probability of each realization. A well known model that can handle…

  13. The global existence problem in general relativity

    CERN Document Server

    Andersson, L

    2000-01-01

    We survey some known facts and open questions concerning the global properties of 3+1 dimensional space--times containing a compact Cauchy surface. We consider space--times with an $\\ell$--dimensional Lie algebra of space--like Killing fields. For each $\\ell \\leq 3$, we give some basic results and conjectures on global existence and cosmic censorship. For the case of the 3+1 dimensional Einstein equations without symmetries, a new small data global existence result is announced.

  14. General problems of roentgenology of stomach ulcer

    International Nuclear Information System (INIS)

    Rizaev, M.N.

    1986-01-01

    It is shown that differential X-ray semiotics should be considered with regard to ulcer localization in one or another part of the stomach. Differential radiodiagnosis of tumoral and non-tumoral nature of ulcerations is based on analyzing the combination of X-ray symptoms, because every separate symptom doesn't reflect the whole variety and complexity of X-ray semiotics of the disease

  15. General quantum variational calculus

    Directory of Open Access Journals (Sweden)

    Artur M. C. Brito da Cruz

    2018-02-01

    Full Text Available We develop a new variational calculus based in the general quantum difference operator recently introduced by Hamza et al. In particular, we obtain optimality conditions for generalized variational problems where the Lagrangian may depend on the endpoints conditions and a real parameter, for the basic and isoperimetric problems, with and without fixed boundary conditions. Our results provide a generalization to previous results obtained for the $q$- and Hahn-calculus.

  16. Speech Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Speech Problems KidsHealth / For Teens / Speech Problems What's in ... a person's ability to speak clearly. Some Common Speech and Language Disorders Stuttering is a problem that ...

  17. Hemiequilibrium problems

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2004-01-01

    Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.

  18. Medical care of employees long-term sick listed due to mental health problems: a cohort study to describe and compare the care of the occupational physician and the general practitioner.

    Science.gov (United States)

    Anema, J R; Jettinghoff, K; Houtman, I; Schoemaker, C G; Buijs, P C; van den Berg, R

    2006-03-01

    To describe medical management by the general practitioner (GP) and occupational physician (OP) of workers sick listed due to mental health problems, and to determine agreement in diagnosis, main cause of sickness absence and obstacles in return to work. A cohort of 555 employees being sick listed for 12 to 20 weeks due to mental health problems was recruited and followed for 1 year. These employees were interviewed about their mental health and contacts with GP, OP, other specialists and employer. In addition, the GP and/or the OP of 72 employees were interviewed about the medical diagnosis and management. Most employees sick listed for 12-20 weeks visited their GP and OP. According to the employees most interventions applied by the GP were medical interventions, such as referral of employees and prescription of medical drugs. Working conditions were seldom discussed by the GP and work-related interventions were never applied. Most interventions applied by the OP were work-related interventions and/or contact with the employer. The OP more often talked about working conditions and conflicts. According to the employees, the communication between GP and OP only took place in 8% of the cases. Agreement in the diagnosis, main cause of sickness absence, and obstacles in return to work reported by the GPs and OPs of the same employee was poor. In addition, similarity in reported diagnosis by GP and/or OP and the employees' scores on valid questionnaires on (mental) health was limited. The lack of communication and agreement by Dutch GPs and OPs in medical diagnosis and management of employees long-term sick listed due to mental health problems are indicators of sub-optimal medical treatment and return-to-work strategies.

  19. Problems in optics

    CERN Document Server

    Rousseau, Madeleine; Ter Haar, D

    1973-01-01

    This collection of problems and accompanying solutions provide the reader with a full introduction to physical optics. The subject coverage is fairly traditional, with chapters on interference and diffraction, and there is a general emphasis on spectroscopy.

  20. The Markov moment problem and extremal problems

    CERN Document Server

    Kreĭn, M G; Louvish, D

    1977-01-01

    In this book, an extensive circle of questions originating in the classical work of P. L. Chebyshev and A. A. Markov is considered from the more modern point of view. It is shown how results and methods of the generalized moment problem are interlaced with various questions of the geometry of convex bodies, algebra, and function theory. From this standpoint, the structure of convex and conical hulls of curves is studied in detail and isoperimetric inequalities for convex hulls are established; a theory of orthogonal and quasiorthogonal polynomials is constructed; problems on limiting values of integrals and on least deviating functions (in various metrics) are generalized and solved; problems in approximation theory and interpolation and extrapolation in various function classes (analytic, absolutely monotone, almost periodic, etc.) are solved, as well as certain problems in optimal control of linear objects.

  1. General report

    International Nuclear Information System (INIS)

    Nicklisch, F.

    1984-01-01

    Growing complexity of technical matter has meant that technical expertise is called upon in more and more legal proceedings. The technical expert is, in general terms, the mediator between technology and the law, he is also entrusted with the task of pointing up the differences in approach and in the nature of authority in these two areas and thus paving the way for mutual understanding. The evaluation of the technical expert's opinion is one of the cardinal problems bound up with the role of the expert in legal procedure. After the presentation of the expert's opinion, the judge is supposed to possess so much specialised knowledge that he can assess the opinion itself in scientific and technical respects and put his finger on any errors the expert may have made. This problem can only be solved via an assessment opinion. First of all, the opinion can be assessed indirectly via evaluation of the credentials and the neutrality and independence of the expert. In direct terms, the opinion can be subjected to a certain - albeit restricted - scrutiny, whether it is generally convincing, as far as the layman is competent to judge. This interpretation alone makes it possible to classify and integrate legally the technical standards and regulations represent expert statements on the scientific and technical theorems based on the knowledge and experience gained in a given area. They are designed to reflect prevailing opinion among leading representatives of the profession and can thus themselves be regarded as expert opinions. As a rule, these opinions will have such weight that - other than in exceptional cases - they will not be invalidated in procedure by deviating opinions from individual experts. (orig./HSCH) [de

  2. The stochastic goodwill problem

    OpenAIRE

    Marinelli, Carlo

    2003-01-01

    Stochastic control problems related to optimal advertising under uncertainty are considered. In particular, we determine the optimal strategies for the problem of maximizing the utility of goodwill at launch time and minimizing the disutility of a stream of advertising costs that extends until the launch time for some classes of stochastic perturbations of the classical Nerlove-Arrow dynamics. We also consider some generalizations such as problems with constrained budget and with discretionar...

  3. Explaining the Mind: Problems, Problems

    OpenAIRE

    Harnad, Stevan

    2001-01-01

    The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

  4. Cosmology problems

    International Nuclear Information System (INIS)

    Lukash, V.N.

    1983-01-01

    Information discussed at the 18th General Assembly of the International Astronomical Union and Symposium on ''Early Universe Evolution and Its Modern Structure'' on the problems of relic radiation, Hubble expansion, spatial structure and physics of the early Universe is presented. The spectrum of relic radioemission differs but slightly from the equilibrium one in the maximum range. In G. Smith (USA) opinion such difference may be caused by any radiosources radiating in the same wave range. The absence of unanimous opinion of astronomers on Hubble constant value is pointed out. G.Tam-man (Switzerland) estimates the Hubble constant 50+-7 km/s. J. Voculer (USA) gives a twice greater value. Such divergence is ca sed by various methods of determining distances up to remote galaxies and galaxy clusters. Many reports deal with large-scale Universe structure. For the first time considered are the processes which occurred in the epoch at times about 10 -35 c from the beginning of the Universe expansion. Such possibility is presented by the theory of ''great unification'' which permits to explain some fundamental properties of the Universe: spatial uniformity of isotropic expansion, existence of small primary density perturbations

  5. Obstacle problems in mathematical physics

    CERN Document Server

    Rodrigues, J-F

    1987-01-01

    The aim of this research monograph is to present a general account of the applicability of elliptic variational inequalities to the important class of free boundary problems of obstacle type from a unifying point of view of classical Mathematical Physics.The first part of the volume introduces some obstacle type problems which can be reduced to variational inequalities. Part II presents some of the main aspects of the theory of elliptic variational inequalities, from the abstract hilbertian framework to the smoothness of the variational solution, discussing in general the properties of the free boundary and including some results on the obstacle Plateau problem. The last part examines the application to free boundary problems, namely the lubrication-cavitation problem, the elastoplastic problem, the Signorini (or the boundary obstacle) problem, the dam problem, the continuous casting problem, the electrochemical machining problem and the problem of the flow with wake in a channel past a profile.

  6. Generalized connectivity of graphs

    CERN Document Server

    Li, Xueliang

    2016-01-01

    Noteworthy results, proof techniques, open problems and conjectures in generalized (edge-) connectivity are discussed in this book. Both theoretical and practical analyses for generalized (edge-) connectivity of graphs are provided. Topics covered in this book include: generalized (edge-) connectivity of graph classes, algorithms, computational complexity, sharp bounds, Nordhaus-Gaddum-type results, maximum generalized local connectivity, extremal problems, random graphs, multigraphs, relations with the Steiner tree packing problem and generalizations of connectivity. This book enables graduate students to understand and master a segment of graph theory and combinatorial optimization. Researchers in graph theory, combinatorics, combinatorial optimization, probability, computer science, discrete algorithms, complexity analysis, network design, and the information transferring models will find this book useful in their studies.

  7. Cross-cultural patterns of the association between varying levels of alcohol consumption and the common mental disorders of depression and anxiety: secondary analysis of the WHO Collaborative Study on Psychological Problems in General Health Care.

    Science.gov (United States)

    Bellos, Stefanos; Skapinakis, Petros; Rai, Dheeraj; Zitko, Pedro; Araya, Ricardo; Lewis, Glyn; Lionis, Christos; Mavreas, Venetsanos

    2013-12-15

    Alcohol consumption is associated with several complications of both physical and mental health. Light or moderate alcohol consumption may have beneficial effects on physical or mental health but this effect is still controversial and research in the mental health field is relatively scarce. Our aim was to investigate the association between varying levels of alcohol consumption and the common mental disorders of depression and anxiety in a large international primary care sample. The sample consisted of 5438 primary care attenders from 14 countries who participated in the WHO Collaborative Study of Psychological Problems in General Health Care. Alcohol use was assessed using Alcohol Use Disorders Identification Test (AUDIT) and the mental disorders were assessed with the Composite International Diagnostic Interview (CIDI). Light to moderate alcohol consumption was associated with a lower prevalence of depression and generalized anxiety disorder compared to abstinence while excessive alcohol consumption was associated with a higher prevalence of depression. This non-linear association was not substantially affected after adjustment for a range of possible confounding variables, including the presence of chronic disease and the current physical status of participants and was evident in different drinking cultures. The study confirms that excessive drinking is associated with an increased prevalence of depression, but also raises the possibility that light/moderate drinking may be associated with a reduced prevalence of both depression and anxiety. Any causal interpretation of this association is difficult in the context of this cross-sectional study and further longitudinal studies are needed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Problems in equilibrium theory

    CERN Document Server

    Aliprantis, Charalambos D

    1996-01-01

    In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

  9. Prostate Problems

    Science.gov (United States)

    ... know the exact cause of your prostate problem. Prostatitis The cause of prostatitis depends on whether you ... prostate problem in men older than age 50. Prostatitis If you have a UTI, you may be ...

  10. Learning Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Learning Problems KidsHealth / For Kids / Learning Problems What's in ... for how to make it better. What Are Learning Disabilities? Learning disabilities aren't contagious, but they ...

  11. Ankle Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Ankle ProblemsFollow this chart for more information about problems that can cause ankle pain. Our trusted Symptom Checker is written and ...

  12. Simon on problem solving

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul

    2006-01-01

    as a general approach to problem solving. We apply these Simonian ideas to organisational issues, specifically new organisational forms. Specifically, Simonian ideas allow us to develop a morphology of new organisational forms and to point to some design problems that characterise these forms.......Two of Herbert Simon's best-known papers are 'The Architecture of Complexity' and 'The Structure of Ill-Structured Problems.' We discuss the neglected links between these two papers, highlighting the role of decomposition in the context of problems on which constraints have been imposed...

  13. Combinatorial problems and exercises

    CERN Document Server

    Lovász, László

    2007-01-01

    The main purpose of this book is to provide help in learning existing techniques in combinatorics. The most effective way of learning such techniques is to solve exercises and problems. This book presents all the material in the form of problems and series of problems (apart from some general comments at the beginning of each chapter). In the second part, a hint is given for each exercise, which contains the main idea necessary for the solution, but allows the reader to practice the techniques by completing the proof. In the third part, a full solution is provided for each problem. This book w

  14. Generalización del método de correlaciones canónicas aplicado a un problema de economía (Generalization of the canonical correlation method applied to an economy problem

    Directory of Open Access Journals (Sweden)

    Jorge Luis Azor Hernández

    2018-03-01

    Full Text Available Resumen. El Análisis de Correlaciones Canónicas (CCA desarrollado por Hotelling entre 1935 y 1936 es un método utilizado para estudiar las relaciones existentes entre dos conjuntos de variables. En 1968 Carroll introdujo una generalización de este método que permite analizar simultáneamente más de dos conjuntos de datos. Otra extensión de CCA es el Análisis de Correlaciones Canónicas Funcional que estudia las relaciones entre dos conjuntos de variables cuando estas transcurren en el tiempo. En este artículo se analiza, mediante estos métodos, la relación entre las ventas y el número de empleados en un problema de la economía mexicana English abstract. Canonical Correlation Analysis (CCA developed by Hotelling between 1935 and 1936 is a method used to study the relationships between two sets of variables. In 1968 Carroll introduced a generalization of this method to simultaneously analyze more than two datasets. Another extension of CCA is Functional Canonical Correlation Analysis that studies the relationships between two sets of variables when they pass in time. In this article, the relationship between sales and the number of employees in a problem of the Mexican economy is analyzed through these methods.

  15. Generalized quasi variational inequalities

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  16. Sociale problemer

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter Verner

    Sociale problemer kan betragtes som selve udgangspunktet for socialt arbejde, hvor ambitionen er at råde bod på problemerne og sikre, at udsatte borgere får en bedre tilværelse. Det betyder også, at diskussionen af sociale problemer er afgørende for den sociale grundfaglighed. I denne bog sætter en...... række fagfolk på tværs af det danske socialfaglige felt fokus på sociale problemer. Det diskuteres, hvad vi overhovedet forstår ved sociale problemer, hvordan de opstår, hvilke konsekvenser de har, og ikke mindst hvordan man som fagprofessionel håndterer sociale problemer i det daglige arbejde. Bogen er...... skrevet som lærebog til professionsuddannelser, hvor sociale problemer udgør en dimension, bl.a. socialrådgiver-, pædagog- og sygeplejerskeuddannelserne....

  17. Some problems on Monte Carlo method development

    International Nuclear Information System (INIS)

    Pei Lucheng

    1992-01-01

    This is a short paper on some problems of Monte Carlo method development. The content consists of deep-penetration problems, unbounded estimate problems, limitation of Mdtropolis' method, dependency problem in Metropolis' method, random error interference problems and random equations, intellectualisation and vectorization problems of general software

  18. No Problem? No Research, Little Learning ... Big Problem!

    Directory of Open Access Journals (Sweden)

    Fernando Ornelas Marques

    2012-06-01

    Full Text Available The motivation to carry out this study stemmed from the generalized perception that nowadays youth lacks the skills for the 21st century. Especially the high-level competences like critical thinking, problem solving and autonomy. Several tools can help to improve these competences (e.g. the SCRATCH programming language, but, as researchers and educators, we are mostly concerned with the skill to recognize problems. What if we do not find problems to solve? What if we do not even feel the need to find or solve problems? The problem is to recognize the problem; the next step is to equate the problem; finally we have to feel the need to solve it. No need? No invention. Recognizing a problem is probably the biggest problem of everyday life, because we are permanently faced with problems (many ill-defined problems, which we need to identify, equate and solve.

  19. Generalized convexity, generalized monotonicity recent results

    CERN Document Server

    Martinez-Legaz, Juan-Enrique; Volle, Michel

    1998-01-01

    A function is convex if its epigraph is convex. This geometrical structure has very strong implications in terms of continuity and differentiability. Separation theorems lead to optimality conditions and duality for convex problems. A function is quasiconvex if its lower level sets are convex. Here again, the geo­ metrical structure of the level sets implies some continuity and differentiability properties for quasiconvex functions. Optimality conditions and duality can be derived for optimization problems involving such functions as well. Over a period of about fifty years, quasiconvex and other generalized convex functions have been considered in a variety of fields including economies, man­ agement science, engineering, probability and applied sciences in accordance with the need of particular applications. During the last twenty-five years, an increase of research activities in this field has been witnessed. More recently generalized monotonicity of maps has been studied. It relates to generalized conve...

  20. Hearing Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Hearing ProblemsLoss in the ability to hear or discriminate ... This flow chart will help direct you if hearing loss is a problem for you or a ...

  1. Polyhedral combinatorics of the cardinality constrained quadratic knapsack problem and the quadratic selective travelling salesman problem

    DEFF Research Database (Denmark)

    Mak, Vicky; Thomadsen, Tommy

    2006-01-01

    This paper considers the cardinality constrained quadratic knapsack problem (QKP) and the quadratic selective travelling salesman problem (QSTSP). The QKP is a generalization of the knapsack problem and the QSTSP is a generalization of the travelling salesman problem. Thus, both problems are NP...

  2. Generalized functions

    CERN Document Server

    Gelfand, I M; Graev, M I; Vilenkin, N Y; Pyatetskii-Shapiro, I I

    Volume 1 is devoted to basics of the theory of generalized functions. The first chapter contains main definitions and most important properties of generalized functions as functional on the space of smooth functions with compact support. The second chapter talks about the Fourier transform of generalized functions. In Chapter 3, definitions and properties of some important classes of generalized functions are discussed; in particular, generalized functions supported on submanifolds of lower dimension, generalized functions associated with quadratic forms, and homogeneous generalized functions are studied in detail. Many simple basic examples make this book an excellent place for a novice to get acquainted with the theory of generalized functions. A long appendix presents basics of generalized functions of complex variables.

  3. Generalized sampling in Julia

    DEFF Research Database (Denmark)

    Jacobsen, Christian Robert Dahl; Nielsen, Morten; Rasmussen, Morten Grud

    2017-01-01

    Generalized sampling is a numerically stable framework for obtaining reconstructions of signals in different bases and frames from their samples. For example, one can use wavelet bases for reconstruction given frequency measurements. In this paper, we will introduce a carefully documented toolbox...... for performing generalized sampling in Julia. Julia is a new language for technical computing with focus on performance, which is ideally suited to handle the large size problems often encountered in generalized sampling. The toolbox provides specialized solutions for the setup of Fourier bases and wavelets....... The performance of the toolbox is compared to existing implementations of generalized sampling in MATLAB....

  4. The moment problem

    CERN Document Server

    Schmüdgen, Konrad

    2017-01-01

    This advanced textbook provides a comprehensive and unified account of the moment problem. It covers the classical one-dimensional theory and its multidimensional generalization, including modern methods and recent developments. In both the one-dimensional and multidimensional cases, the full and truncated moment problems are carefully treated separately. Fundamental concepts, results and methods are developed in detail and accompanied by numerous examples and exercises. Particular attention is given to powerful modern techniques such as real algebraic geometry and Hilbert space operators. A wide range of important aspects are covered, including the Nevanlinna parametrization for indeterminate moment problems, canonical and principal measures for truncated moment problems, the interplay between Positivstellensätze and moment problems on semi-algebraic sets, the fibre theorem, multidimensional determinacy theory, operator-theoretic approaches, and the existence theory and important special topics of multidime...

  5. Problem Posing

    OpenAIRE

    Šilhavá, Marie

    2009-01-01

    This diploma thesis concentrates on problem posing from the students' point of view. Problem posing can be either seen as a teaching method which can be used in the class, or it can be used as a tool for researchers or teachers to assess the level of students' understanding of the topic. In my research, I compare three classes, one mathematics specialist class and two generalist classes, in their ability of problem posing. As an assessment tool it seemed that mathemathics specialists were abl...

  6. Popular Problems

    DEFF Research Database (Denmark)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....

  7. Sleep Problems

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... 101 KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  8. Mouth Problems

    Science.gov (United States)

    ... such as sores, are very common. Follow this chart for more information about mouth problems in adults. ... cancers. See your dentist if sharp or rough teeth or dental work are causing irritation. Start OverDiagnosisThis ...

  9. Kidney Problems

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & Information The kidneys are two ... kidney (renal) diseases are called nephrologists . What are Kidney Diseases? For about one-third of older people, ...

  10. General Editorial

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. General Editorial. Articles in Resonance – Journal of Science Education. Volume 19 Issue 1 January 2014 pp 1-2 General Editorial. General Editorial on Publication Ethics · R Ramaswamy · More Details Fulltext PDF. Volume 19 Issue 1 January 2014 pp 3-3 ...

  11. Knapsack problems

    CERN Document Server

    Kellerer, Hans; Pisinger, David

    2004-01-01

    Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num­ ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...

  12. General minisum circle location

    DEFF Research Database (Denmark)

    Körner, Mark; Brimberg, Jack; Juel, Henrik

    2009-01-01

    In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points is minim......In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points...

  13. "Righting" the Writing Problem.

    Science.gov (United States)

    Shaughnessy, Michael F.; Eastham, Nicholas

    The problem of college students' writing skills or lack thereof is generally agreed upon in academia. One cause is the inordinate amount of multiple choice/true false/fill in the blank type of tests that students take in high school and college. Not only is there is a dearth of actual classes in writing available, few students recognize the need…

  14. The Bycatch Problem

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 5. The Bycatch Problem - Effects of Commercial Fisheries on Non-Target Species in India. Aaron Savio Lobo. General Article Volume 12 Issue 5 May 2007 pp 60-70 ...

  15. The interactive effect of paternal problem drinking and maternal problem drinking on adolescent internalizing problems.

    Science.gov (United States)

    Ohannessian, Christine McCauley

    2015-11-01

    This study examined the effects of both paternal problem drinking and maternal problem drinking on adolescent internalizing problems (depression and anxiety symptomatology). Surveys were administered to 566 10th and 11th grade students from the Mid-Atlantic region of the U.S. in the spring of 2007 and again in the spring of 2008. Although significant main effects were not observed, significant interactions were found between paternal problem drinking and maternal problem drinking for internalizing problems, especially for boys. In general, these interactions indicated that when paternal problem drinking was high, depression symptomatology and anxiety symptomatology were lower if maternal problem drinking was low. Findings from this study highlight the need to consider both paternal and maternal problem drinking when examining the effects that parental problem drinking may have on adolescent adjustment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Calculus problems

    CERN Document Server

    Baronti, Marco; van der Putten, Robertus; Venturi, Irene

    2016-01-01

    This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...

  17. Ensinar capacidades gerais de resolução de problemas não é uma substituição, nem um complemento viável, a ensinar matemática [Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics

    NARCIS (Netherlands)

    Sweller, John; Clark, Richard; Kirschner, Paul A.

    2012-01-01

    Sweller, J., Clark, R. E., & Kirschner, P. A. (2012). Ensinar capacidades gerais de resolução de problemas não é uma substituição, nem um complemento viável, a ensinar matemática [Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics]. Gazeta

  18. Generalized product

    OpenAIRE

    Greco, Salvatore; Mesiar, Radko; Rindone, Fabio

    2014-01-01

    Aggregation functions on [0,1] with annihilator 0 can be seen as a generalized product on [0,1]. We study the generalized product on the bipolar scale [–1,1], stressing the axiomatic point of view. Based on newly introduced bipolar properties, such as the bipolar increasingness, bipolar unit element, bipolar idempotent element, several kinds of generalized bipolar product are introduced and studied. A special stress is put on bipolar semicopulas, bipolar quasi-copulas and bipolar copulas.

  19. Thyroid Problems

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Thyroid Problems Font size A A A Print Share Glossary Basic ... enough thyroid hormone, usually of the thyroxine (T4) type of hormone. Your T4 levels can drop temporarily ...

  20. Balance Problems

    Science.gov (United States)

    ... fully trust your sense of balance. Loss of balance also raises the risk of falls. This is a serious and even life-threatening ... 65. Balance disorders are serious because of the risk of falls. But occasionally balance problems may warn of another health condition, such ...

  1. Generalizations of orthogonal polynomials

    Science.gov (United States)

    Bultheel, A.; Cuyt, A.; van Assche, W.; van Barel, M.; Verdonk, B.

    2005-07-01

    We give a survey of recent generalizations of orthogonal polynomials. That includes multidimensional (matrix and vector orthogonal polynomials) and multivariate versions, multipole (orthogonal rational functions) variants, and extensions of the orthogonality conditions (multiple orthogonality). Most of these generalizations are inspired by the applications in which they are applied. We also give a glimpse of these applications, which are usually generalizations of applications where classical orthogonal polynomials also play a fundamental role: moment problems, numerical quadrature, rational approximation, linear algebra, recurrence relations, and random matrices.

  2. Generalized vector calculus on convex domain

    Science.gov (United States)

    Agrawal, Om P.; Xu, Yufeng

    2015-06-01

    In this paper, we apply recently proposed generalized integral and differential operators to develop generalized vector calculus and generalized variational calculus for problems defined over a convex domain. In particular, we present some generalization of Green's and Gauss divergence theorems involving some new operators, and apply these theorems to generalized variational calculus. For fractional power kernels, the formulation leads to fractional vector calculus and fractional variational calculus for problems defined over a convex domain. In special cases, when certain parameters take integer values, we obtain formulations for integer order problems. Two examples are presented to demonstrate applications of the generalized variational calculus which utilize the generalized vector calculus developed in the paper. The first example leads to a generalized partial differential equation and the second example leads to a generalized eigenvalue problem, both in two dimensional convex domains. We solve the generalized partial differential equation by using polynomial approximation. A special case of the second example is a generalized isoperimetric problem. We find an approximate solution to this problem. Many physical problems containing integer order integrals and derivatives are defined over arbitrary domains. We speculate that future problems containing fractional and generalized integrals and derivatives in fractional mechanics will be defined over arbitrary domains, and therefore, a general variational calculus incorporating a general vector calculus will be needed for these problems. This research is our first attempt in that direction.

  3. Generalized rough sets

    International Nuclear Information System (INIS)

    Rady, E.A.; Kozae, A.M.; Abd El-Monsef, M.M.E.

    2004-01-01

    The process of analyzing data under uncertainty is a main goal for many real life problems. Statistical analysis for such data is an interested area for research. The aim of this paper is to introduce a new method concerning the generalization and modification of the rough set theory introduced early by Pawlak [Int. J. Comput. Inform. Sci. 11 (1982) 314

  4. Work and General Education.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and the Pacific.

    Presentations and other materials are provided from the Asia and the Pacific Programme of Educational Innovation for Development (APEID) Planning and Review Meeting on Work as an Integral Part of General Education. The focus is on how education, through an orientation to work, could help to decrease the gravity of the problems of population…

  5. Algebraic properties of generalized inverses

    CERN Document Server

    Cvetković‐Ilić, Dragana S

    2017-01-01

    This book addresses selected topics in the theory of generalized inverses. Following a discussion of the “reverse order law” problem and certain problems involving completions of operator matrices, it subsequently presents a specific approach to solving the problem of the reverse order law for {1} -generalized inverses. Particular emphasis is placed on the existence of Drazin invertible completions of an upper triangular operator matrix; on the invertibility and different types of generalized invertibility of a linear combination of operators on Hilbert spaces and Banach algebra elements; on the problem of finding representations of the Drazin inverse of a 2x2 block matrix; and on selected additive results and algebraic properties for the Drazin inverse. In addition to the clarity of its content, the book discusses the relevant open problems for each topic discussed. Comments on the latest references on generalized inverses are also included. Accordingly, the book will be useful for graduate students, Ph...

  6. Complementarity problems

    CERN Document Server

    Isac, George

    1992-01-01

    The study of complementarity problems is now an interesting mathematical subject with many applications in optimization, game theory, stochastic optimal control, engineering, economics etc. This subject has deep relations with important domains of fundamental mathematics such as fixed point theory, ordered spaces, nonlinear analysis, topological degree, the study of variational inequalities and also with mathematical modeling and numerical analysis. Researchers and graduate students interested in mathematical modeling or nonlinear analysis will find here interesting and fascinating results.

  7. Agricultural problems

    International Nuclear Information System (INIS)

    Bickerton, George E.

    1997-01-01

    Although there were not reasons to deplore against major activity release from any of the 110 industrial reactors authorized to operate in US, the nuclear incident that occurred at the Three Mile Island Plant in 1979 urged the public conscience toward the necessity of readiness to cope with events of this type. The personnel of the Emergency Planning Office functioning in the frame of US Department of Agriculture has already participated in around 600 intervention drillings on a federal, local or state scale to plan, test or asses radiological emergency plans or to intervene locally. These exercises allowed acquiring a significant experience in elaborating emergency plans, planning the drillings, working out scenarios and evaluation of the potential impact of accidents from the agricultural point of view. We have also taken part in different international drillings among which the most recent are INEX 1 and RADEX 94. We have found on these occasions that the agricultural problems are essential preoccupations in most of the cases no matter if the context is international, national, local or of state level. The paper poses problems specifically related to milk, fruits and vegetables, soils, meat and meat products. Finally the paper discusses issues like drilling planning, alarm and notification, sampling strategy, access authorizations for farmers, removing of contamination wastes. A number of social, political and economical relating problems are also mentioned

  8. Problems over Information Systems

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    The problems of estimation of the minimum average time complexity of decision trees and design of efficient algorithms are complex in general case. The upper bounds described in Chap. 2.4.3 can not be applied directly due to large computational complexity of the parameter M(z). Under reasonable assumptions about the relation of P and NP, there are no polynomial time algorithms with good approximation ratio [12, 32]. One of the possible solutions is to consider particular classes of problems and improve the existing results using characteristics of the considered classes. © Springer-Verlag Berlin Heidelberg 2011.

  9. Solving Environmental Problems

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph

    2017-01-01

    for Research and Technological Development (FP7), our results indicate that the problem-solving potential of a search strategy increases with the diversity of existing knowledge of the partners in a consortium and with the experience of the partners involved. Moreover, we identify a substantial negative effect...... dispersed. Hence, firms need to collaborate. We shed new light on collaborative search strategies led by firms in general and for solving environmental problems in particular. Both topics are largely absent in the extant open innovation literature. Using data from the European Seventh Framework Program...

  10. The Problem Revisited

    DEFF Research Database (Denmark)

    Ovesen, Nis

    2015-01-01

    Problem-based learning (PBL) is becoming increasingly popular in design educations, but how is it taught and practiced? This paper presents a case study of a three-day workshop that has the purpose of introducing PBL to design students. A theoretical background on PBL and problems in design is es...... is established and is backing up the case study. The study shows that design engineering and architectural students without experience in PBL in general finds the approach to be beneficial when working on a design challenge in a student team....

  11. General relativity

    International Nuclear Information System (INIS)

    Kenyon, I.R.

    1990-01-01

    General relativity is discussed in this book at a level appropriate to undergraduate students of physics and astronomy. It describes concepts and experimental results, and provides a succinct account of the formalism. A brief review of special relativity is followed by a discussion of the equivalence principle and its implications. Other topics covered include the concepts of curvature and the Schwarzschild metric, test of the general theory, black holes and their properties, gravitational radiation and methods for its detection, the impact of general relativity on cosmology, and the continuing search for a quantum theory of gravity. (author)

  12. Simon on Problem-Solving

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul

    as a general approach to problem solving. We apply these Simonian ideas to organizational issues, specifically new organizational forms. Specifically, Simonian ideas allow us to develop a morphology of new organizational forms and to point to some design problems that characterize these forms.Keywords: Herbert...... Simon, problem-solving, new organizational forms. JEL Code: D23, D83......Two of Herbert Simon's best-known papers are "The Architecture of Complexity" and "The Structure of Ill-Structured Problems." We discuss the neglected links between these two papers, highlighting the role of decomposition in the context of problems on which constraints have been imposed...

  13. Generalized Recovery

    DEFF Research Database (Denmark)

    Jensen, Christian Skov; Lando, David; Pedersen, Lasse Heje

    We characterize when physical probabilities, marginal utilities, and the discount rate can be recovered from observed state prices for several future time periods. Our characterization makes no assumptions of the probability distribution, thus generalizing the time-homogeneous stationary model...

  14. General Conformity

    Science.gov (United States)

    The General Conformity requirements ensure that the actions taken by federal agencies in nonattainment and maintenance areas do not interfere with a state’s plans to meet national standards for air quality.

  15. Problems in Cybersemiotic Modelling

    DEFF Research Database (Denmark)

    Brier, Søren

    2014-01-01

    the Peircean theory of the observer as the phaneroscopic foundation. 4. Cobley points out that both models, as they are combined in Cybersemiotics lacks to integrate a theory of interest and power. They are too consensual in their view on communication. This is a general problem in both theories. Still Luhmann...... do work with the power problem in his triple autopoietic communicative system theory as he sees communication specialized into generalized symbolic media, with no controlling center in the modern industrialized media society. Another way to go is Habermas’ critical theory in a social semiotic theory......Going from an empirical to an informational paradigm of cognition and communication, does not really help us to analyze, how the living systems manage to make a meaningful interpretation of environment that is useful for their survival and procreation. Other models are needed. 1. There is von...

  16. A Problem on Optimal Transportation

    Science.gov (United States)

    Cechlarova, Katarina

    2005-01-01

    Mathematical optimization problems are not typical in the classical curriculum of mathematics. In this paper we show how several generalizations of an easy problem on optimal transportation were solved by gifted secondary school pupils in a correspondence mathematical seminar, how they can be used in university courses of linear programming and…

  17. Generalized polygons

    CERN Document Server

    Van Maldeghem, Hendrik

    1998-01-01

    Generalized Polygons is the first book to cover, in a coherent manner, the theory of polygons from scratch. In particular, it fills elementary gaps in the literature and gives an up-to-date account of current research in this area, including most proofs, which are often unified and streamlined in comparison to the versions generally known. Generalized Polygons will be welcomed both by the student seeking an introduction to the subject as well as the researcher who will value the work as a reference. In particular, it will be of great value for specialists working in the field of generalized polygons (which are, incidentally, the rank 2 Tits-buildings) or in fields directly related to Tits-buildings, incidence geometry and finite geometry. The approach taken in the book is of geometric nature, but algebraic results are included and proven (in a geometric way!). A noteworthy feature is that the book unifies and generalizes notions, definitions and results that exist for quadrangles, hexagons, octagons - in the ...

  18. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  19. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

  20. Generalized Power Domination

    OpenAIRE

    Omerzel, Aleš

    2014-01-01

    The power domination problem is an optimization problem that has emerged together with the development of the power networks. It is important to control the voltage and current in all the nodes and links in a power network. Measuring devices are expensive, which is why there is a tendency to place a minimum number of devices in a power network so that the network remains fully supervised. The k-power domination is a generalization of the power domination. The thesis represents the rules of th...