Remarks on brachistochrone-tautochrone problems
Denman, Harry H.
1985-03-01
A number of recent papers have discussed brachistochrone (minimum-time) and tautochrone (equal-time) curves for a number of gravitational and rotating systems. The symmetry of the physical system is useful in solving brachistochrone problems expressed in variational form. We point out that such symmetries are equally useful in solving the associated Euler-Lagrange equations, or solving tautochrone differential equations. These brachistochrone problems share a common mathematical form, and therefore a common procedure for reducing the problem to quadrature. It is shown that the cusps characteristic of these curves have a simple physical origin. Finally, the question of the most general spherically symmetric gravitation potential for which the brachistochrone and tautochrone curves are identical is answered in implicit form.
Paul Bunyan's Brachistochrone and Tautochrone
Energy Technology Data Exchange (ETDEWEB)
HURTADO,JOHN E.
2000-08-21
In this paper we concern ourselves with modified versions of the traditional brachistochrone and tautochrone problems. In the modified version of each problem the constant gravity model is replaced with an attractive inverse square law, consequently we name these the 1/{tau}{sup 2} brachistochrone and 1/{tau}{sup 2} tautochrone problems. With regard to the 1/{tau}{sup 2} brachistochrone problem, we show that the shape of the minimizing curve is formally constructed from an infinite series of elliptic integrals, and we use a numerical optimal control technique to generate the trajectories. The 1/{tau}{sup 2} tautochrone problem is solved using fraction calculus together with Lagrange's rule for tautochronous curves
Brachistochrones, Tautochrones, Evolutes, and Tessellations.
McKinley, John M.
1979-01-01
This article shows that the centrifugal force in a rotating reference frame possesses the property that the brachistochrone and tautochrone are identical. In this system the force is repulsive and proportional to the distance from the force center. (Author/BB)
On generalized operator quasi-equilibrium problems
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.
Generalizations of the Brachistochrone Problem
Gemmer, J.; Umble, R.; Nolan, M.
2006-01-01
Consider a frictionless surface S in a gravitational field that need not be uniform. Given two points A and B on S, what curve is traced out by a particle that starts at A and reaches B in the shortest time? This paper considers this problem on simple surfaces such as surfaces of revolution and solves the problem two ways: First, we use conservation of mechanical energy and the Euler-Lagange equation; second, we use geometrical optics and the eikonal equation. We conclude with a discussion of...
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
The generalized minimum spanning tree problem
Pop, P.C.; Kern, Walter; Still, Georg J.
2000-01-01
We consider the Generalized Minimum Spanning Tree Problem denoted by GMSTP. It is known that GMSTP is NP-hard and even finding a near optimal solution is NP-hard. We introduce a new mixed integer programming formulation of the problem which contains a polynomial number of constraints and a
Generalized network improvement and packing problems
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.
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.
Initial Value Problem in General Relativity
Isenberg, James
2013-01-01
This article, written to appear as a chapter in "The Springer Handbook of Spacetime", is a review of the initial value problem for Einstein's gravitational field theory in general relativity. Designed to be accessible to graduate students who have taken a first course in general relativity, the article first discusses how to reformulate the spacetime fields and spacetime covariant field equations of Einstein's theory in terms of fields and field equations compatible with a 3+1 foliation of sp...
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
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...
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...... (Castellammare di Stabia). Alcohol problems, which were defined by a cut-off score of 5 on the MAST and/or by heavy alcohol consumption (corresponding to at least 60 g of ethanol daily for males and 36 g of ethanol daily for females for at least 2 years), were identified in 54 patients [43.9%; 95% confidence...... heavy alcohol consumption had a predictive negative value of 97.2% (95% CI 90.2-99.7%) and a predictive positive value of 73.1% (95% CI 59.0-84.4%) in relation to MAST positive patients. It is suggested that general practitioners should incorporate this question about heavy alcohol consumption...
Gambling Problems in the General Danish Population
DEFF Research Database (Denmark)
Harrison, Glenn W.; Jessen, Lasse J.; Lau, Morten
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...... ratesof detectable gambling risk groups, since gambling behavior is positively correlated with the decision to participate in gambling surveys. We also find that imposing a threshold gambling history leads to underestimation of the prevalence of gambling problems.......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...
A generalization of the convex Kakeya problem
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.
PROBLEMS OF GENERAL PRACTICE IN RURAL CALIFORNIA
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
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
A generalization of the convex Kakeya problem
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.
The Generalized Fixed-Charge Network Design Problem
DEFF Research Database (Denmark)
Thomadsen, Tommy; Stidsen, Thomas K.
2007-01-01
In this paper we present the generalized fixed-charge network design (GFCND) problem. The GFCND problem is an instance of the so-called generalized network design problems. In such problems, clusters instead of nodes have to be interconnected by a network. The network interconnecting the clusters...... is a fixed-charge network, and thus the GFCND problem generalizes the fixed-charge network design problem. The GFCND problem is related to the more general problem of designing hierarchical telecommunication networks. A mixed integer programming model is described and a branch-cut-and-price algorithm...
The dual of a generalized minimax location problem
DEFF Research Database (Denmark)
Juel, Henrik; Love, Robert F.
1992-01-01
This paper develops the dual formulation of a generalized minimax facility location problem which has distance and linear constraints......This paper develops the dual formulation of a generalized minimax facility location problem which has distance and linear constraints...
General problems of modeling for accelerators
International Nuclear Information System (INIS)
Luccio, A.
1991-01-01
In this presentation the author only discusses problems of modeling for circular accelerators and bases the examples on the AGS Booster Synchrotron presently being commissioned at BNL. A model is a platonic representation of an accelerator. With algorithms, implemented through computer codes, the model is brought to life. At the start of a new accelerator project, the model and the real machine are taking shape somewhat apart. They get closer and closer as the project goes on. Ideally, the modeler is only satisfied when the model or the machine cannot be distinguished. Accelerator modeling for real time control has specific problems. If one wants fast responses, algorithms may be implemented in hardware or by parallel computation, perhaps by neural networks. Algorithms and modeling is not only for accelerator control. It is also for: accelerator parameter measurement; hardware problem debugging, perhaps with some help of artificial intelligence; operator training, much like a flight simulator
Exponential operators, generalized polynomials and evolution problems
International Nuclear Information System (INIS)
Dattoli, G.; Mancho, A.M.; Quattromini, M.; Torre, A.
2001-01-01
The operator (d/dx) χ d/dx plays a central role in the theory of operational calculus. Its exponential form is crucial in problems relevant to solutions of Fokker-Planck and Schroedinger equations. We explore the formal properties of the evolution operators associated to (d/dx) χ d/dx, discuss its link to special forms of Laguerre polynomials and Laguerre-based functions. The obtained results are finally applied to specific problems concerning the solution of Fokker-Planck equations relevant to the beam lifetime in storage rings
A General Solution for Troesch's Problem
Directory of Open Access Journals (Sweden)
Hector Vazquez-Leal
2012-01-01
Full Text Available The homotopy perturbation method (HPM is employed to obtain an approximate solution for the nonlinear differential equation which describes Troesch’s problem. In contrast to other reported solutions obtained by using variational iteration method, decomposition method approximation, homotopy analysis method, Laplace transform decomposition method, and HPM method, the proposed solution shows the highest degree of accuracy in the results for a remarkable wide range of values of Troesch’s parameter.
Prevalence of alcohol problems in general practice
DEFF Research Database (Denmark)
Rambaldi, A; Todisco, N; Gluud, C
1996-01-01
heavy alcohol consumption had a predictive negative value of 97.2% (95% CI 90.2-99.7%) and a predictive positive value of 73.1% (95% CI 59.0-84.4%) in relation to MAST positive patients. It is suggested that general practitioners should incorporate this question about heavy alcohol consumption...
The Human Mind As General Problem Solver
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.
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.
Minimal connections: the classical Steiner problem and generalizations
Directory of Open Access Journals (Sweden)
Emanuele Paolini
2012-12-01
Full Text Available The classical Steiner problem is the problem of finding the shortest graph connecting a given finite set of points. In this seminar we review the classical problem and introduce a new, generalized formulation, which extends the original one to infinite sets in metric spaces.
Recent results on a general financial equilibrium problem
Barbagallo, Annamaria; Daniele, Patrizia; Lorino, Mariagrazia; Maugeri, Antonino; Mirabella, Cristina
2013-10-01
The paper is devoted to the study of a general financial equilibrium problem which is modeled by means of a variational inequality. The main theoretical results obtained in these last years are presented.
Book Review: Solving Language Problems: From General to ...
African Journals Online (AJOL)
Abstract. Book Title: Solving Language Problems: From General to Applied Linguistics. Book Author: R.R.K. Hartmann (Ed.) 1st edition 1996, vi + 298 pp. ISBN 0-85989-484-3. Exeter: University of Exeter Press.
The analysis of singletons in generalized birthday problems
Koot, M.R.; Mandjes, M.R.H.
2012-01-01
This paper describes techniques to characterize the number of singletons in the setting of the generalized birthday problem, that is, the birthday problem in which the birthdays are non-uniformly distributed over the year. Approximations for the mean and variance presented which explicitly indicate
Bounds in the generalized Weber problem under locational uncertainty
DEFF Research Database (Denmark)
Juel, Henrik
1981-01-01
An existing analysis of the bounds on the Weber problem solution under uncertainty is incorrect. For the generalized problem with arbitrary measures of distance, we give easily computable ranges on the bounds and state the conditions under which the exact values of the bounds can be found...... with little computational effort. Numerical examples illustrate the analysis....
Child dental fear and general emotional problems: a pilot study
Krikken, J.B.; ten Cate, J.M.; Veerkamp, J.S.J.
2010-01-01
AIM: This was to investigate the relation between general emotional and behavioural problems of the child and dental anxiety and dental behavioural management problems. BACKGROUND: Dental treatment involves many potentially unpleasant stimuli, which all may lead to the development of dental anxiety
Procrustes Problems for General, Triangular, and Symmetric Toeplitz Matrices
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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.
Higher-Order Generalized Invexity in Control Problems
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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.
Local Conjecturing Process in the Solving of Pattern Generalization Problem
Sutarto; Nusantara, Toto; Subanji; Sisworo
2016-01-01
This aim of this study is to describe the process of local conjecturing in generalizing patterns based on Action, Process, Object, Schema (APOS) theory. The subjects were 16 grade 8 students from a junior high school. Data collection used Pattern Generalization Problem (PGP) and interviews. In the first stage, students completed PGP; in the second…
A general approach to posterior contraction in nonparametric inverse problems
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
Generalized Nash equilibrium problems, bilevel programming and mpec
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...
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.)
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....... For a general controlled Markov process and a fairly general objective functional we derive an extension of the standard Hamilton-Jacobi-Bellman equation, in the form of a system of on-linear equations, for the determination for the equilibrium strategy as well as the equilibrium value function. All known...... 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...
Varying domains in a general class of sublinear elliptic problems
Directory of Open Access Journals (Sweden)
Santiago Cano-Casanova
2004-05-01
Full Text Available In this paper we use the linear theory developed in [8] and [9] to show the continuous dependence of the positive solutions of a general class of sublinear elliptic boundary value problems of mixed type with respect to the underlying domain. Our main theorem completes the results of Daners and Dancer [12] -and the references there in-, where the classical Robin problem was dealt with. Besides the fact that we are working with mixed non-classical boundary conditions, it must be mentioned that this paper is considering problems where bifurcation from infinity occurs; now a days, analyzing these general problems, where the coefficients are allowed to vary and eventually vanishing or changing sign, is focusing a great deal of attention -as they give rise to metasolutions (e.g., [20]-.
Municipal solid waste management problems: an applied general equilibrium analysis
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
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,.
Digital Competence: general problems and experimental practices concerning highschools
Directory of Open Access Journals (Sweden)
Roberto Gris
2015-10-01
Full Text Available In the current social context Information and Communication Technologies (ICT are more and more present and pervasive and the European institutions enter the Digital Competence in the Key Competences for Lifelong Learning. In this focus we are deepened the general problems of Digital Competence and competence-based education and to describe experimental practices concerning highschools.
Generalized birthday problems in the large-deviations regime
Mandjes, M.
2014-01-01
This paper considers generalized birthday problems, in which there are d classes of possible outcomes. A fraction f i of the N possible outcomes has probability α i /N, where $\\sum_{i=1}^{d} f_{i} =\\sum_{i=1}^{d} f_{i}\\alpha_{i}=1$. Sampling k times (with replacements), the objective is to determine
Refinements, Generalizations, and Applications of Jordan's Inequality and Related Problems
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Feng Qi
2009-01-01
Full Text Available This is a survey and expository article. Some new developments on refinements, generalizations, and applications of Jordan's inequality and related problems, including some results about Wilker-Anglesio's inequality, some estimates for three kinds of complete elliptic integrals, and several inequalities for the remainder of power series expansion of the exponential function, are summarized.
Problem-Based Learning in a General Psychology Course.
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.)…
The Neumann Problem for the Laplace Equation on General Domains
Czech Academy of Sciences Publication Activity Database
Medková, Dagmar
2007-01-01
Roč. 57, č. 4 (2007), s. 1107-1139 ISSN 0011-4642 Institutional research plan: CEZ:AV0Z10190503 Keywords : Laplace equation * Neumann problem * potential Subject RIV: BA - General Mathematics Impact factor: 0.155, year: 2007
Polymorphic Uncertain Linear Programming for Generalized Production Planning Problems
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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.
Application of Neutrosophic Set Theory in Generalized Assignment Problem
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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.
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
Redesigning problem solving component in General Physics course.
Shakov, Jerry; McGuire, Jim
2007-04-01
Problem-based learning has been widely used in teaching introductory/general physics courses for a long time. The role of problem-solving sessions in the learning process is absolutely critical: they give the students an opportunity to learn how to apply both newly and previously acquired knowledge to practical situations, how to put together different strategies and portions of material, and much more. Unfortunately, the traditional format used for the problem solving sessions is not very accommodative for the goal: large class sizes and limited time often force instructors to spend most of the time solving sample problems in front of the class, which leaves the students with the role of passive observers. In this work, we will discuss how one can involve the students in the process of active learning using collaborative strategies and principles of cognitive apprenticeship.
General terms and rigidity: another solution to the trivialization problem
Directory of Open Access Journals (Sweden)
Eleonora Orlando
2014-06-01
Full Text Available In this paper I am concerned with the problem of applying the notion of rigidity to general terms. In Naming and Necessity, Kripke has clearly suggested that we should include some general terms among the rigid ones, namely, those common nouns semantically correlated with natural substances, species and phenomena, in general, natural kinds -'water', 'tiger', 'heat'- and some adjectives -'red', 'hot', 'loud'. However, the notion of rigidity has been defined for singular terms; after all, the notion that Kripke has provided us with is the notion of a rigid designator. But general terms do not designate single individuals: rather, they apply to many of them. In sum, the original concept of rigidity cannot be straightforwardly applied to general terms: it has to be somehow redefined in order to make it cover them. As is known, two main positions have been put forward to accomplish that task: the identity of designation conception, according to which a rigid general term is one that designates the same property or kind in all possible worlds, and the essentialist conception, which conceives of a rigid general term as an essentialist one, namely, a term that expresses an essential property of an object. My purpose in the present paper is to defend a particular version of the identity of designation conception: on the proposed approach, a rigid general term will be one that expresses the same property in all possible worlds and names the property it expresses. In my opinion, the position can be established on the basis of an inference to the best explanation of our intuitive interpretation and evaluation, relative to counterfactual circumstances, of statements containing different kinds of general terms, which is strictly analogous to our intuitive interpretation and evaluation, relative to such circumstances, of statements containing different kinds of singular ones. I will argue that it is possible to offer a new solution to the trivialization
A general solution to some plane problems of micropolar elasticity
DEFF Research Database (Denmark)
Warren, William E.; Byskov, Esben
2008-01-01
that micropolar effects are most significant in material regions subjected to large deformation gradients. Specific results are presented for the classical crack problem, the half plane loaded uniformly on the surface, Flamant's problem, and the circular cylinder compressed by equal and opposite oncentrated......We obtain a general solution to the field equations of plane micropolar elasticity for materials characterized by a hexagonal or equilateral triangular structure. These materials exhibit 3-fold symmetry in the plane and the elastic response is isotropic. Utilizing two displacement potential...
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
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.
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.
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.
General Problem Solving Strategies Employed in the Mexican Mathematical Olympiad
Directory of Open Access Journals (Sweden)
María del Consuelo Valle Espinosa
2007-11-01
Full Text Available This article describes the general strategies applied to problem solving in the State Math Olympiad selection test, in Puebla, Mexico. It analyzes the answers of 91 participants, ages 14 to 17, from junior high school and high school. Whether participants reached a problem solution or not, they rendered their results in one answer sheet and the arguments for those results in other. These answer sheets were used to form a database with 546 results. The sheets selected for the database were those in which participants identified the unknown factor, data and condition of the problem, in addition to have offered one or several solution strategies. Then, strategies were verbally described, their usage frequency calculated, and their effect on the different branches of mathematics depending on the problem analyzed. The strategy or strategies provided by participants were examined to identify stages of problem solving. The results showed that only 5% of the answer sheets had complete solutions. That emphasizes the need to systematize the State training courses for the National Olympiad. The importance of the training course is directly related to its purpose: to prepare young people for the National Olympiad and to enrich the Higher Education System of Puebla with students interested in doing science careers, with the ability to develop their hypothetical–deductive reasoning successfully.
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.
The problem of time quantum mechanics versus general relativity
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 ...
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
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.
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
Generalized Mixed Equilibria, Variational Inclusions, and Fixed Point Problems
Directory of Open Access Journals (Sweden)
A. E. Al-Mazrooei
2014-01-01
Full Text Available We propose two iterative algorithms for finding a common element of the set of solutions of finite generalized mixed equilibrium problems, the set of solutions of finite variational inclusions for maximal monotone and inverse strong monotone mappings, and the set of common fixed points of infinite nonexpansive mappings and an asymptotically κ-strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove some strong and weak convergence theorems for the proposed iterative algorithms under suitable conditions.
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].
Origins and development of the Cauchy problem in general relativity
Ringström, Hans
2015-06-01
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 also closely
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)
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.
Topological approach to the generalized n-centre problem
Bolotin, S. V.; Kozlov, V. V.
2017-06-01
This paper considers a natural Hamiltonian system with two degrees of freedom and Hamiltonian H=\\Vert p\\Vert^2/2+V(q). The configuration space M is a closed surface (for non-compact M certain conditions at infinity are required). It is well known that if the potential energy V has n>2χ(M) Newtonian singularities, then the system is not integrable and has positive topological entropy on the energy level H=h>\\sup V. This result is generalized here to the case when the potential energy has several singular points a_j of type V(q)∼ -\\operatorname{dist}(q,a_j)-α_j. Let A_k=2-2k-1, k\\in{N}, and let n_k be the number of singular points with A_k≤slant α_jk+1. It is proved that if \\displaystyle \\sum2≤slant k≤slant∞n_kA_k>2χ(M), then the system has a compact chaotic invariant set of collision-free trajectories on any energy level H=h>\\sup V. This result is purely topological: no analytical properties of the potential energy are used except the presence of singularities. The proofs are based on the generalized Levi-Civita regularization and elementary topology of coverings. As an example, the plane n-centre problem is considered. Bibliography: 29 titles.
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)
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)
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 characterizatio...
Utility Generalization and Composability Problems in Explanation-Based Learning.
Gratch, Jonathan M.; DeJong, Gerald F.
The PRODIGY/EBL system [Minton88] was one of the first works to directly attack the problem of strategy utility. The problem of finding effective strategies was reduced to the problem of finding effective rules. However, this paper illustrates limitations of the approach. There are two basic difficulties. The first arises from the fact that the…
Fuzzy Generalized Variational Like Inequality problems in Topological Vector Spaces
Directory of Open Access Journals (Sweden)
M. K. Ahmad
2013-01-01
Full Text Available This paper is devoted to the existence of solutions for generalized variational like inequalities with fuzzy mappings in topological vector spaces by using a particular form of the generalized KKM-Theorem.
Institutional Problems and Solutions of General Education in Chinese Universities
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…
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.
Top Element Problem and Macneille Completions of Generalized Effect Algebras
RieČanová, Z.; Kalina, M.
2014-10-01
Effect algebras (EAs), introduced by D. J. Foulis and M. K. Bennett, as common generalizations of Boolean algebras, orthomodular lattices and MV-algebras, are nondistributive algebraic structures including unsharp elements. Their unbounded versions, called generalized effect algebras, are posets which may have or may have not an EA-MacNeille completion, or cannot be embedded into any complete effect algebra. We give a necessary and sufficient condition for a generalized effect algebra to have an EA-MacNeille completion. Some examples are provided.
Optimal portfolio selection for general provisioning and terminal wealth problems
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.
Optimal portfolio selection for general provisioning and terminal wealth problems
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
Navier-Stokes Solvers and Generalizations for Reacting Flow Problems
Energy Technology Data Exchange (ETDEWEB)
Elman, Howard C
2013-01-27
This is an overview of our accomplishments during the final term of this grant (1 September 2008 -- 30 June 2012). These fall mainly into three categories: fast algorithms for linear eigenvalue problems; solution algorithms and modeling methods for partial differential equations with uncertain coefficients; and preconditioning methods and solvers for models of computational fluid dynamics (CFD).
Integer programming for the generalized high school timetabling problem
DEFF Research Database (Denmark)
Kristiansen, Simon; Sørensen, Matias; Stidsen, Thomas Riis
2015-01-01
Recently, the XHSTT format for high school timetabling was introduced. It provides a uniform way of modeling problem instances and corresponding solutions. The format supports a wide variety of constraints, and currently 38 real-life instances from 11 different countries are available. Thereby...
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)
Generalized mixed finite element method for 3D elasticity problems
Qing, Guanghui; Mao, Junhui; Liu, Yanhong
2017-06-01
Without applying any stable element techniques in the mixed methods, two simple generalized mixed element (GME) formulations were derived by combining the minimum potential energy principle and Hellinger-Reissner (H-R) variational principle. The main features of the GME formulations are that the common C0 -continuous polynomial shape functions for displacement methods are used to express both displacement and stress variables, and the coefficient matrix of these formulations is not only automatically symmetric but also invertible. Hence, the numerical results of the generalized mixed methods based on the GME formulations are stable. Displacement as well as stress results can be obtained directly from the algebraic system for finite element analysis after introducing stress and displacement boundary conditions simultaneously. Numerical examples show that displacement and stress results retain the same accuracy. The results of the noncompatible generalized mixed method proposed herein are more accurate than those of the standard noncompatible displacement method. The noncompatible generalized mixed element is less sensitive to element geometric distortions.
Nonlinear Analysis of the Generalized Thermo-Magnetodynamic Problem
Czech Academy of Sciences Publication Activity Database
Nedoma, Jiří
1995-01-01
Roč. 63, 1/3 (1995), s. 393-402 ISSN 0377-0427. [Modelling'94. Prague, 29.08.1994-02.09.1994] Grant - others:COPERNICUS(XE) 94-00820 Keywords : generalized magnetodynamics * partial differential equations * variational inequalities * viscoplasticity * geodynamics * magnetic field of planets * astrophysics Impact factor: 0.373, year: 1995
General Systems Theory Approaches to Organizations: Some Problems in Application
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…
The problem of diagnostic variability in general practice.
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
A generalization of the Birthday problem and the chromatic polynomial
Fadnavis, Sukhada
2011-01-01
The birthday paradox states that there is at least a 50% chance that some two out of twenty-three randomly chosen people will share the same birth date. The calculation for this problem assumes that all birth dates are equally likely. We consider the following two modifications of this question. If the distribution of birthdays is non-uniform, does that increase or decrease the probability of matching birth dates? Further, what if we focus on birthdays shared by some particular pairs rather t...
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
Introduction to the concept of thermal stability: expression of the general problem
International Nuclear Information System (INIS)
Llory, M.; Planchard, J.
1981-01-01
In the first part, an introduction is given to the concept of thermal stability, based firstly on experimental results and secondly on a simplified formulation of the problem. In the second part, the above considerations are generalized: the general problem of thermal stability is stated and it is shown that it can be considered as an eigenvalue problem. In the third part, a simple application of the general case is developed [fr
Generalized single-hidden layer feedforward networks for regression problems.
Wang, Ning; Er, Meng Joo; Han, Min
2015-06-01
In this paper, traditional single-hidden layer feedforward network (SLFN) is extended to novel generalized SLFN (GSLFN) by employing polynomial functions of inputs as output weights connecting randomly generated hidden units with corresponding output nodes. The significant contributions of this paper are as follows: 1) a primal GSLFN (P-GSLFN) is implemented using randomly generated hidden nodes and polynomial output weights whereby the regression matrix is augmented by full or partial input variables and only polynomial coefficients are to be estimated; 2) a simplified GSLFN (S-GSLFN) is realized by decomposing the polynomial output weights of the P-GSLFN into randomly generated polynomial nodes and tunable output weights; 3) both P- and S-GSLFN are able to achieve universal approximation if the output weights are tuned by ridge regression estimators; and 4) by virtue of the developed batch and online sequential ridge ELM (BR-ELM and OSR-ELM) learning algorithms, high performance of the proposed GSLFNs in terms of generalization and learning speed is guaranteed. Comprehensive simulation studies and comparisons with standard SLFNs are carried out on real-world regression benchmark data sets. Simulation results demonstrate that the innovative GSLFNs using BR-ELM and OSR-ELM are superior to standard SLFNs in terms of accuracy, training speed, and structure compactness.
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.)
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
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…
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.
A generalization of szebehely's inverse problem of dynamics in dimension three
Sarlet, W.; Mestdag, T.; Prince, G.
2017-06-01
Extending a previous paper, we present a generalization in dimension 3 of the traditional Szebehely-type inverse problem. In that traditional setting, the data are curves determined as the intersection of two families of surfaces, and the problem is to find a potential V such that the Lagrangian L = T - V, where T is the standard Euclidean kinetic energy function, generates integral curves which include the given family of curves. Our more general way of posing the problem makes use of ideas of the inverse problem of the calculus of variations and essentially consists of allowing more general kinetic energy functions, with a metric which is still constant, but need not be the standard Euclidean one. In developing our generalization, we review and clarify different aspects of the existing literature on the problem and illustrate the relevance of the newly introduced additional freedom with many examples.
Zwaanswijk, Marieke; Verhaak, Peter F M; van der Ende, Jan; Bensing, Jozien M; Verhulst, Frank C
2005-10-01
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. To investigate in a general population sample of 2,449 Dutch children and adolescents (4-17 years) GP consultation and GP diagnoses of child psychological problems, and the influence of child and family characteristics upon these variables. The degree to which parent, teacher, and adolescent reports of the presence of child psychological problems are in concordance with GP diagnoses of these problems was determined. Logistic regression analyses were used to examine correlates of GP consultation and psychological diagnoses. Approximately 80% of children and adolescents with psychological problems had visited their GP within the preceding year. GP consultation was most strongly associated with child/adolescent chronic physical disorders. Concordance between GP psychological diagnoses and parent, teacher, and adolescent reports of psychological problems was limited. Children and adolescents with psychological problems according to parent or teacher report, children with school problems, young boys, adolescents with negative health perceptions, and adolescents from single parent families were more likely to be diagnosed with psychological problems by GPs. Improving GPs' interview techniques, introducing standardised screening measures in general practice, increasing GPs' awareness of the possible presence of psychological problems in children consulting for physical problems, and strengthening collaboration between GPs and mental health professionals may increase GP identification of child psychological problems and enhance access to care for those in need.
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)
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.
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
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
Zantinge, E.M.; Verhaak, P.F.M.; Kerssens, J.J.; Bensing, J.M.
2006-01-01
Background: Many mental problems are not recognized by the general practitioner (GP). Recognition of these problems is important because it is one of the critical stages in finding appropriate care for the patient. GPs are sometimes reluctant to get involved in mental health care because it requires
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
DEFF Research Database (Denmark)
Helsgaun, Keld
2015-01-01
The equality generalized traveling salesman problem (E-GTSP) is an extension of the traveling salesman problem (TSP) where the set of cities is partitioned into clusters, and the salesman has to visit every cluster exactly once. It is well known that any instance of E-GTSP can be transformed...
The course of mental health problems in children presenting with abdominal pain in general practice
Gieteling, Marieke J.; Lisman-Van Leeuwen, Yvone; Passchier, Jan; Koes, Bart W.; Berger, Marjolein Y.; Leuwen, Y.L.V.
Objective. To investigate the course of mental health problems in children presenting to general practice with abdominal pain and to evaluate the extent to which abdominal pain characteristics during follow-up predict the presence of mental health problems at 12 months' follow-up. Design. A
The course of mental health problems in children presenting with abdominal pain in general practice
Passchier, J.; Gieteling, M.J.; Lisman-Van Leeuwen, Y.; Koes, B.W.; Berger, M.Y.
2012-01-01
Objective. To investigate the course of mental health problems in children presenting to general practice with abdominal pain and to evaluate the extent to which abdominal pain characteristics during follow-up predict the presence of mental health problems at 12 months' follow-up. Design. A
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.)
Consultations for mental problems in general practices with and without mental health nurses.
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
Statistical problem of ideal gas in general two-dimensional regions
Song, Ci; Li, Wen-Du; Mwansa, Pardon; Zhang, Ping
2015-09-01
In this paper, based on the conformal mapping method and the perturbation theory, we develop a method to solve the statistical problem within general two-dimensional regions. We consider some examples and the numerical results and fitting results are given. We also give the thermodynamic quantities of the general two-dimensional regions, and compare the thermodynamic quantities of the different regions.
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
Gambling problems among patients in primary care: a cross-sectional study of general practices.
Cowlishaw, Sean; Gale, Lone; Gregory, Alison; McCambridge, Jim; Kessler, David
2017-04-01
Primary care is an important context for addressing health-related behaviours, and may provide a setting for identification of gambling problems. To indicate the extent of gambling problems among patients attending general practices, and explore settings or patient groups that experience heightened vulnerability. Cross-sectional study of patients attending 11 general practices in Bristol, South West England. Adult patients ( n = 1058) were recruited from waiting rooms of practices that were sampled on the basis of population characteristics. Patients completed anonymous questionnaires comprising measures of mental health problems (for example, depression) and addictive behaviours (for example, risky alcohol use). The Problem Gambling Severity Index (PGSI) measured gambling problems, along with a single-item measure of gambling problems among family members. Estimates of extent and variability according to practice and patient characteristics were produced. There were 0.9% of all patients exhibiting problem gambling (PGSI ≥5), and 4.3% reporting problems that were low to moderate in severity (PGSI 1-4). Around 7% of patients reported gambling problems among family members. Further analyses indicated that rates of any gambling problems (PGSI ≥1) were higher among males and young adults, and more tentatively, within a student healthcare setting. They were also elevated among patients exhibiting drug use, risky alcohol use, and depression. There is need for improved understanding of the burden of, and responses to, patients with gambling problems in general practices, and new strategies to increase identification to facilitate improved care and early intervention. © British Journal of General Practice 2017.
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.
Exact Post-Selection Inference for Changepoint Detection and Other Generalized Lasso Problems
Hyun, Sangwon; G'Sell, Max; Tibshirani, Ryan J.
2016-01-01
We study tools for inference conditioned on model selection events that are defined by the generalized lasso regularization path. The generalized lasso estimate is given by the solution of a penalized least squares regression problem, where the penalty is the l1 norm of a matrix D times the coefficient vector. The generalized lasso path collects these estimates for a range of penalty parameter ({\\lambda}) values. Leveraging a sequential characterization of this path from Tibshirani & Taylor (...
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.
Gambling problems among patients in primary care: a cross-sectional study of general practices
Cowlishaw, Sean; Gale, Lone; Gregory, Alison; McCambridge, Jim; Kessler, David
2017-01-01
Background Primary care is an important context for addressing health-related behaviours, and may provide a setting for identification of gambling problems. Aim To indicate the extent of gambling problems among patients attending general practices, and explore settings or patient groups that experience heightened vulnerability. Design and setting Cross-sectional study of patients attending 11 general practices in Bristol, South West England. Method Adult patients (n = 1058) were recruited from waiting rooms of practices that were sampled on the basis of population characteristics. Patients completed anonymous questionnaires comprising measures of mental health problems (for example, depression) and addictive behaviours (for example, risky alcohol use). The Problem Gambling Severity Index (PGSI) measured gambling problems, along with a single-item measure of gambling problems among family members. Estimates of extent and variability according to practice and patient characteristics were produced. Results There were 0.9% of all patients exhibiting problem gambling (PGSI ≥5), and 4.3% reporting problems that were low to moderate in severity (PGSI 1–4). Around 7% of patients reported gambling problems among family members. Further analyses indicated that rates of any gambling problems (PGSI ≥1) were higher among males and young adults, and more tentatively, within a student healthcare setting. They were also elevated among patients exhibiting drug use, risky alcohol use, and depression. Conclusion There is need for improved understanding of the burden of, and responses to, patients with gambling problems in general practices, and new strategies to increase identification to facilitate improved care and early intervention. PMID:28289016
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.
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.
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...... 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....
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.
Learning generalization in problem solving by a blue-fronted parrot (Amazona aestiva).
de Mendonça-Furtado, Olívia; Ottoni, Eduardo B
2008-10-01
Pepperberg (The Alex studies: cognitive and communicative abilities of gray parrots. Harvard University Press, Cambridge;1999) showed that some of the complex cognitive capabilities found in primates are also present in psittacine birds. Through the replication of an experiment performed with cotton-top tamarins (Saguinus oedipus oedipus) by Hauser et al. (Anim Behav 57:565-582; 1999), we examined a blue-fronted parrot's (Amazona aestiva) ability to generalize the solution of a particular problem in new but similar cases. Our results show that, at least when it comes to solving this particular problem, our parrot subject exhibited learning generalization capabilities resembling the tamarins'.
State and problems of physical education in regional general education educational institutions
Мамешина, Маргарита Анатоліївна; Масляк, Ірина Павлівна
2015-01-01
Margarita Mameshina, Irina MaslyakPurpose: to study a state and problems of physical education in regional general education educational institutions. Material and Methods: 29 teachers of physical culture of Izyum and Izyum district of the Kharkov region took part in the research. The following methods were used: theoretical analysis and generalization of scientific literature, opinion poll, and mathematical statistics. Results: it is established that most of teachers aren't absolutely satisf...
State and problems of physical education in regional general education educational institutions
Mameshina, Margarita; Maslyak, Irina; Zhuk, Vjacheslav
2015-01-01
Purpose: to study a state and problems of physical education in regional general education educational institutions. Material and Methods: 29 teachers of physical culture of Izyum and Izyum district of the Kharkov region took part in the research. The following methods were used: theoretical analysis and generalization of scientific literature, opinion poll, and mathematical statistics. Results: it is established that most of teachers aren't absolutely satisfied with the relation of pupils to...
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.
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
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
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
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.
M. Nool (Margreet); A. van der Ploeg (Auke)
1997-01-01
textabstractWe study the solution of generalized eigenproblems generated by a model which is used for stability investigation of tokamak plasmas. The eigenvalue problems are of the form $A x = lambda B x$, in which the complex matrices $A$ and $B$ are block tridiagonal, and $B$ is Hermitian positive
Parametric general variational-like inequality problem in uniformly smooth Banach space
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Kazmi KR
2006-01-01
Full Text Available Using the concept of - -proximal mapping, we study the existence and sensitivity analysis of solution of a parametric general variational-like inequality problem in uniformly smooth Banach space. The approach used may be treated as an extension and unification of approaches for studying sensitivity analysis for various important classes of variational inequalities given by many authors in this direction.
R.R.K. Hartmann (Ed.). Solving Language Problems: From General to
African Journals Online (AJOL)
Solving Language Problems: From General to. Applied Linguistics, 1st edition 1996, vi + 298 pp. ISBN 0-85989-484-3. Exeter: University of Exeter Press. Price £13,95. Questions about the nature of linguistics and its contribution to human intel- lectual pursuit often appear in academic discussions and in casual conversa-.
Nakai, Minori; Hotta, Hiroshi; Ootsuru, Taku; Hiejima, Shigeto; Murakami, Masaru; Yuzuriha, Takefumi; Kondo, Tsuyoshi
2013-04-01
In Japan, many problems related to alcohol are pointed out from before. We believe that there is a unique drinking culture in Okinawa, such as a large amount of alcohol. Therefore, we estimate many people in Okinawa have a drinking problem. We conducted a survey of patients who visited general hospital (medical or surgical or orthopedic) in 2007. The purpose of this study is to collect basic data for introducing alcoholics to specialized treatment as early as possible, detecting the person who drink large amounts of alcohol, performing early intervention for people who drink large amount of alcohol, and advancing cooperation with specialized medical agencies of alcohol. As a result, Among the patients who visited general hospital in Okinawa, many problem drinkers are concentrated in the young age. and they have strong fears of health. The possibility of early intervention with intervention techniques, such as brief intervention, has been suggested.
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.
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
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.
Generalized multiscale finite element methods for problems in perforated heterogeneous domains
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
Magrabi, Farah; Liaw, Siaw Teng; Arachi, Diana; Runciman, William; Coiera, Enrico; Kidd, Michael R
2016-11-01
To identify the categories of problems with information technology (IT), which affect patient safety in general practice. General practitioners (GPs) reported incidents online or by telephone between May 2012 and November 2013. Incidents were reviewed against an existing classification for problems associated with IT and the clinical process impacted. 87 GPs across Australia. Types of problems, consequences and clinical processes. GPs reported 90 incidents involving IT which had an observable impact on the delivery of care, including actual patient harm as well as near miss events. Practice systems and medications were the most affected clinical processes. Problems with IT disrupted clinical workflow, wasted time and caused frustration. Issues with user interfaces, routine updates to software packages and drug databases, and the migration of records from one package to another generated clinical errors that were unique to IT; some could affect many patients at once. Human factors issues gave rise to some errors that have always existed with paper records but are more likely to occur and cause harm with IT. Such errors were linked to slips in concentration, multitasking, distractions and interruptions. Problems with patient identification and hybrid records generated errors that were in principle no different to paper records. Problems associated with IT include perennial risks with paper records, but additional disruptions in workflow and hazards for patients unique to IT, occasionally affecting multiple patients. Surveillance for such hazards may have general utility, but particularly in the context of migrating historical records to new systems and software updates to existing systems. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Variational methods for problems from plasticity theory and for generalized Newtonian fluids
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.
Directory of Open Access Journals (Sweden)
Qinghai He
2013-01-01
Full Text Available In general Banach spaces, we consider a vector optimization problem (SVOP in which the objective is a set-valued mapping whose graph is the union of finitely many polyhedra or the union of finitely many generalized polyhedra. Dropping the compactness assumption, we establish some results on structure of the weak Pareto solution set, Pareto solution set, weak Pareto optimal value set, and Pareto optimal value set of (SVOP and on connectedness of Pareto solution set and Pareto optimal value set of (SVOP. In particular, we improved and generalize, Arrow, Barankin, and Blackwell’s classical results in Euclidean spaces and Zheng and Yang’s results in general Banach spaces.
The stochastic mechanics of fields in a general relativistic context: Problems and perspectives
International Nuclear Information System (INIS)
De Falco, D.
1987-01-01
The problem of a formulation of Nelson's stochastic mechanics of scalar fields in the context of general relativity is considered. The simple example of the scalar field in the Wightman vacuum state on the Rindler wedge is examined, the stochastic counterpart of the Fulling ambiguity of canonical quantization is formulated, and the role of the stochastic quantization is formulated, and the role of the stochastic mechanics of thermal mixtures, as formulated by Guerra and Loffredo, is analyzed in the solution, in the spirit of Davies and Unruh, of the above ambiguity. An overall picture emerges which, both in the explicit example considered here and in its straightforward generalizations to static submanifolds of more general space-times, confirms Smolin's point of view that stochastic quantization is a very natural conceptual frame in which to study the general non covariance of the distinction between quantum and thermal fluctuations. (orig.)
General practice-based clinical trials in Germany - a problem analysis
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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
New generalized variable stepsizes of the CQ algorithm for solving the split feasibility problem
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Peiyuan Wang
2017-06-01
Full Text Available Abstract Variable stepsize methods are effective for various modified CQ algorithms to solve the split feasibility problem (SFP. The purpose of this paper is first to introduce two new simpler variable stepsizes of the CQ algorithm. Then two new generalized variable stepsizes which can cover the former ones are also proposed in real Hilbert spaces. And then, two more general KM (Krasnosel’skii-Mann-CQ algorithms are also presented. Several weak and strong convergence properties are established. Moreover, some numerical experiments have been taken to illustrate the performance of the proposed stepsizes and algorithms.
Association of Problem Gambling with Type of Gambling Among Italian General Population.
Scalese, Marco; Bastiani, Luca; Salvadori, Stefano; Gori, Mercedes; Lewis, Isabella; Jarre, Paolo; Molinaro, Sabrina
2016-09-01
The origin of gambling disorders is uncertain; however, research has shown a tendency to focus on specific types of games as a potential important risk factor. The principal aim of this study is to examine the relationships between types of gambling practices and gambling disorder. The data were extracted from IPSAD-Italia(®) 2010-2011 (Italian Population Survey on Alcohol and other Drugs), a survey among the Italian general population which collects socio-cultural information, information about the use of drugs, legal substances and gambling habits. In order to identify the "problem gambler" we used the Problem Gambling Severity Index. Three groups are considered in this analysis: no-risk gamblers, low-risk gamblers, moderate-risk/problem gamblers. Type of gambling practice was considered among two types of gambler: one-game players and multi-games players. 1.9 % of multi-game players were considered problem gamblers, only 0.6 % of one-game players were problem gamblers (p gambling severity was associated with multi-game players (OR = 2.23, p gambling severity among both one-game players and multi-game players, with scores of OR equal to 4.3 and 4.5 respectively. These findings suggest a popular perception of risk associated with this type of gambling for the development of gambling problems.
Algorithm for Solving a Generalized Mixed Equilibrium Problem with Perturbation in a Banach Space
Kum Sangho; Yao Jen-Chih; Ceng Lu-Chuan
2010-01-01
Let be a real Banach space with the dual space . Let be a proper functional and let be a bifunction. In this paper, a new concept of -proximal mapping of with respect to is introduced. The existence and Lipschitz continuity of the -proximal mapping of with respect to are proved. By using properties of the -proximal mapping of with respect to , a generalized mixed equilibrium problem with perturbation (for short, GMEPP) is introduced and studied in Banach space . An exis...
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)
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
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
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.
Kim, Hyoun S; Salmon, Melissa; Wohl, Michael J A; Young, Matthew
2016-04-01
The current research examined whether alcohol consumption exacerbates suicidal ideations among gamblers in the general population. While prior research suggests problem gambling severity and excessive alcohol consumption are unique predictors of suicidal behaviors, the extant literature as almost exclusively focused on gamblers in treatment. This represents a significant gap in the literature as less than 10% of gamblers seek treatment. Furthermore, gamblers in treatment are not representative of gamblers in the general population, precluding a simple generalization of research findings. We address this gap using data obtained from the Canadian Community Health Survey (Cycle 4.1)--a cross-sectional national survey that assesses health-related information among the Canadian population. To this end, we conducted a moderation analysis with problem gambling severity as the independent variable, weekly alcohol consumption as the moderator variable and suicidal ideations (in the past 12 months) as the dependent variable. The results found that alcohol consumption alone did not reliably predict suicidal ideation among gamblers who did not gamble problematically. However, as predicted, the odds of suicidal ideation were greatest among problem gamblers who frequently consumed alcohol. Thus, it may behoove policy makers to re-visit the availability of alcohol in gambling venues. Moreover, responsible gambling-oriented education initiatives may be advanced by informing gamblers about the increased risk of suicidal ideations when problematic gambling is combined with frequent alcohol consumption.
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.
PROBLEMS OF EFFICIENCY OF BUDGET SPENDING ON GENERAL EDUCATION DURING ITS REFORMING
Directory of Open Access Journals (Sweden)
E. B. Krylova
2016-01-01
Full Text Available This article presents an analysis of the main problems of the Russian general education during the ongoing reform of the general education system, as well as identified the main reasons for reducing the efficiency of budget spending in this area.Analysis is based on data provided by the State Statistics Service of the changes in the number of state and municipal educational institutions for the period of the general reform of the education sector from 1981 to 2016. The authors highlighted that reduced the total number of educational institutions of higher education, compared with 2014. by 5.7% and significantly reduced the number of students and school pupils in particular on specific professional areas, and there was a decrease in the overall number of educational institutions.The authors identified factors that influenced this process, including the demographic collapse in the birth rate in the last decade of the 20th century and marks them active reform activities of the Government of the Russian Federation in the field of general education. The dynamics in the financing of general education. The problems of financing of general education, which is not so much the amount of funds allocated, how much as using them in the educational process.The main problems of inefficient budget spending on general education authors attributed such as: the lack of a unified approach to the optimization of budgets (by type of education spending; inadequate budget planning and control system, lack of a direct link between allocated resources and indicators of the effectiveness of the educational institutions; procedural complications monitoring the effectiveness of budget spending. The necessity to optimize the proportion of the federal budget for education spending and improve the utilization of allocated budget, which will undoubtedly impact on improving the quality of educational services.The authors noted the key role of the budget funding for support of
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)
Still a difficult business? Negotiating alcohol-related problems in general practice consultations.
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.
A Nitsche cut finite element method for the Oseen problem with general Navier boundary conditions
Winter, M.; Schott, B.; Massing, A.; Wall, W. A.
2018-03-01
In this work a Nitsche-based imposition of generalized Navier conditions on cut meshes for the Oseen problem is presented. Other methods from literature dealing with the generalized Navier condition impose this condition by means of substituting the tangential Robin condition in a classical Galerkin way. These methods work fine for a large slip length coefficient but lead to conditioning and stability issues when it approaches zero. We introduce a novel method for the weak imposition of the generalized Navier condition which remains well-posed and stable for arbitrary choice of slip length, including zero. The method proposed here builds on the formulation done by [1]. They impose a Robin condition for the Poisson problem by means of Nitsche's method for an arbitrary combination of the Dirichlet and Neumann parts of the condition. The analysis conducted for the proposed method is done in a similar fashion as in [2], but is done here for a more general type of boundary condition. The analysis proves stability for all flow regimes and all choices of slip lengths. Also an L2-optimal estimate for the velocity error is shown, which was not conducted in the previously mentioned work. A numerical example is carried out for varying slip lengths to verify the robustness and stability of the method with respect to the choice of slip length. Even though proofs and formulations are presented for the more general case of an unfitted grid method, they can easily be reduced to the simpler case of a boundary-fitted grid with the removal of the ghost-penalty stabilization terms.
International Nuclear Information System (INIS)
Garba, Abdou; Haldenwang, Pierre
2003-01-01
The aim of the paper is concerned with the iterative resolution of the generalized Stokes problem in the framework of collocation Chebyshev approximation. More precisely, we analyze the performance of several preconditioners improving the classical Uzawa method. We first recall that the general Stokes problem (GSP) is an elementary substep of general interest for computing not only incompressible flows but also low Mach number flows. We then remark that performances of the classical Uzawa algorithm for solving the GSP are in fact closely related to the Reynolds number. In order to overcome this dependence, preconditioners are needed. The preconditioners we analyze here are recommended by Fourier analysis of the pressure operator. We additionally give interpretation of the preconditioners in terms of influence (or capacitance) techniques. We give a detailed analysis of the conditioning of the discrete collocation Chebyshev versions of the operators. Numerical comparison is conducted in 2D as well as in 3D rectangular geometry. Our comparative study shows that the fictitious wall permeability (FWP) method is the most efficient preconditioner. If complemented with a suitable pressure filtering, its efficiency still increases
The initial boundary value problem for free-evolution formulations of general relativity
Hilditch, David; Ruiz, Milton
2018-01-01
We consider the initial boundary value problem for free-evolution formulations of general relativity coupled to a parametrized family of coordinate conditions that includes both the moving puncture and harmonic gauges. We concentrate primarily on boundaries that are geometrically determined by the outermost normal observer to spacelike slices of the foliation. We present high-order-derivative boundary conditions for the gauge, constraint violating and gravitational wave degrees of freedom of the formulation. Second order derivative boundary conditions are presented in terms of the conformal variables used in numerical relativity simulations. Using Kreiss–Agranovich–Métivier theory we demonstrate, in the frozen coefficient approximation, that with sufficiently high order derivative boundary conditions the initial boundary value problem can be rendered boundary stable. The precise number of derivatives required depends on the gauge. For a choice of the gauge condition that renders the system strongly hyperbolic of constant multiplicity, well-posedness of the initial boundary value problem follows in this approximation. Taking into account the theory of pseudo-differential operators, it is expected that the nonlinear problem is also well-posed locally in time.
Guo, Peng; Cheng, Wenming; Wang, Yi
2014-10-01
The quay crane scheduling problem (QCSP) determines the handling sequence of tasks at ship bays by a set of cranes assigned to a container vessel such that the vessel's service time is minimized. A number of heuristics or meta-heuristics have been proposed to obtain the near-optimal solutions to overcome the NP-hardness of the problem. In this article, the idea of generalized extremal optimization (GEO) is adapted to solve the QCSP with respect to various interference constraints. The resulting GEO is termed the modified GEO. A randomized searching method for neighbouring task-to-QC assignments to an incumbent task-to-QC assignment is developed in executing the modified GEO. In addition, a unidirectional search decoding scheme is employed to transform a task-to-QC assignment to an active quay crane schedule. The effectiveness of the developed GEO is tested on a suite of benchmark problems introduced by K.H. Kim and Y.M. Park in 2004 (European Journal of Operational Research, Vol. 156, No. 3). Compared with other well-known existing approaches, the experiment results show that the proposed modified GEO is capable of obtaining the optimal or near-optimal solution in a reasonable time, especially for large-sized problems.
Efficient generalized Golub-Kahan based methods for dynamic inverse problems
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.
A general approach to regularizing inverse problems with regional data using Slepian wavelets
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.
Assessment of achievement in problem-solving skills in a General Chemistry course
Directory of Open Access Journals (Sweden)
Patricia Morales Bueno
2014-12-01
Full Text Available This article reports the development and validation study of tests to assess achievements at three levels of knowledge structure, following the model proposed by Sugrue to measure problem-solving skills. This model is particularly consistent with the theoretical constructs underlying problem-based learning (PBL methodology. The tests were constructed for a General Chemistry course in a curriculum of engineering, which implements PBL methodology at a Peruvian university. The content validation of the tests was performed, as well as a pilot implementation with Peruvian students of first year enginnering. The results obtained in omissions percentage, difficulty degree, items response pattern and the point biserial coefficient (rpb, let us to conclude that these are appropiate tools for assessing these skills, so constitute a significant contribution to future research in this line.
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.
[Validation of the general help-seeking questionnaire for mental health problems in adolescents].
Olivari, Cecilia; Guzmán-González, Mónica
2017-06-01
Help-seeking behavior is a protective factor in young people, essential for their mental health, well-being and development. However, some adolescents do not seek professional help when they need to. In this context, it is relevant to study the help-seeking behavior for mental health problems in adolescent population. To adapt and validate the general help-seeking questionnaire for mental health problems in Chilean adolescents. Cross-sectional and correlational study of a non-random sample of 793 adolescent students, between 14 and 19 years old, from the city of Talca (Chile). The general help-seeking questionnaire, vignette version, (GHSQ-V) was administered after a transcultural adaptation and criterion validation. Descriptive statistics, exploratory factor analysis and non-parametric Mann-Whitney U test were used for analysis. An exploratory analysis identified two factors regarding available sources of help: 1) informal sources; 2) formal sources. Reliability was calculated separately for each of the health problems, resulting alpha values ranging from 0.87 to 0.75. In addition, the scale showed significant association with the variables self-efficacy and depression in the hypothesized directions. Finally, significant differences were identified in the willingness to seek help by adolescents level of mental health literacy, for all mental health issues presented, except suicide. The adaptation of the GHSQ-V for Chilean adolescent and youth population is a valid and reliable instrument to measure willingness to seek help for mental health problems in our socio-cultural environment.
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 fo...... new integer linear programming formulations for the GVRP, two based on multicommodity flow and the other two based on exponential sets of inequalities. Branch-and-cut algorithms are proposed for the latter two. Computational results on a large set of instances are presented....
Georgevic, R. M.; Anderson, J. D.
1973-01-01
The relationships between the osculating orbital elements for a family of solutions of the general relativistic Schwarzschild problems are developed. These relationships provide a method for evaluating orbital elements in different Schwarzschild coordinate systems without the necessity of fitting to real data every time the system of coordinates is changed. The objectivity of different coordinate systems is discussed. Considerations of orbital motions favor the standard Schwarzschild metric, but the propagation of light signals is more objective in the metric of Painleve. Because the orbital motions usually dominate the representation of data, the standard Schwarzschild coordinates are the best objective choice for most applications.
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
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.
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
Multi-choice stochastic transportation problem involving general form of distributions.
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.
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)
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
Rijswijk, E. van; Borghuis, M.; Lisdonk, E.H. van de; Zitman, F.G.; Weel, C. van
2007-01-01
OBJECTIVE: Real-life data on the treatment of patients with mental health problems are important as a reference to evaluate care and benchmarking. This study describes the treatment of mental health problems in general practice as diagnosed by general practitioners (GP). MATERIAL AND METHODS: Data
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)
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…
An analysis of the Rayleigh–Stokes problem for a generalized second-grade fluid
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.
Equihash: Asymmetric Proof-of-Work Based on the Generalized Birthday Problem
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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.
Particle size-shape distributions: the general spheroid problem. I. Mathematical model.
Orive, L M
1976-08-01
The development of stereological methods for the study of dilute phases of particles, voids or organelles embedded in a matrix, from measurements made on plane or linear intercepts through the aggregate, has deserved a great deal of effort. With almost no exception, the problem of describing the particulate phase is reduced to that of identifying the statistical distribution--histogram in practice--of a relevant size parameter, with the previous assumption that the particles are modelled by geometrical objects of a constant shape (e.g. spheres). Therefore, particles exhibiting a random variation about a given type of shape as well as a random variation in size, escape previous analyses. Such is the case of unequiaxed particles modelled by triaxial ellipsoids of variable size and eccentricity parameters. It has been conjectured (Moran, 1972) that this problem is indetermined in its generally (i.e. the elliptical sections do not furnish a sufficient information which permits a complete description of the ellipsoids). A proof of this conjecture is given in the Appendix. When the ellipsoids are biaxial (spheroids) and of the same type (prolate or oblate), the problem is identifiable. Previous attempts to solve it assume statistical independence between size and shape. A complete, theoretical solution of the spheroids problem--with the independence condition relaxed--is presented. A number of exact relationships--some of them of a striking simplicity--linking particle properties (e.g. mean-mean caliper length, mean axial ratio, correlation coefficient between principal diameters, etc.) on the one hand, with the major and minor dimensions of the ellipses of section on the other, emerge, and natural, consistent estimators of the mentioned properties are made easily accessible for practical computation. Finally, the scope and limitations of the mathematical model are discussed.
Handy, C R; Okbagabir, S; Yarahmad, T
2003-01-01
For one-dimensional Schroedinger quantum systems, the correlation expression S(x, tau, a) ident to PSI*(x - tau/2/a)PSI(x + tau/2) satisfies a fourth-order linear differential equation with regard to x. This generalizes the result previously derived by Handy (2001 J. Phys. A: Math. Gen. 34 L271), and Handy and Wang (2001 J. Phys. A: Math. Gen. 34 8297), with regard to S(x, 0, 1). We are then able to incorporate this within a generalized Wigner transform representation, through the use of scalets (Handy C R and Brooks H A 2001 J. Phys. A: Math. Gen. 34 3577). Energy quantization is achieved through a moment problem positivity analysis (focusing on the moments of the probability density, vertical bar PSI vertical bar sup 2) at a=1, tau=0. The wavefunction, PSI, is then generated through a multiscale analysis proceeding from the unity scale, extended into the zero scale limit. The power moments, mu sub p =integral dx x sup p PSI(x), can be generated through a similar procedure. We present the general formalism a...
General competencies of problem-based learning (PBL) and non-PBL graduates.
Prince, Katinka J A H; van Eijs, Patrick W L J; Boshuizen, Henny P A; van der Vleuten, Cees P M; Scherpbier, Albert J J A
2005-04-01
Junior doctors have reported shortcomings in their general competencies, such as organisational skills and teamwork. We explored graduates' perceptions of how well their training had prepared them for medical practice and in general competencies in particular. We compared the opinions of graduates from problem-based learning (PBL) and non-PBL schools, because PBL is supposed to enhance general competencies. We analysed the responses of 1159 graduates from 1 PBL and 4 non-PBL schools to a questionnaire survey administered 18 months after graduation. Compared with their non-PBL colleagues, the PBL graduates gave higher ratings for the connection between school and work, their medical training and preparation for practice. According to the graduates, the most frequently used competencies with sufficient coverage during medical training were expert knowledge, profession-specific skills and communication skills. The majority of the PBL graduates, but less than half of the non-PBL graduates, indicated that communication skills had been covered sufficiently. All the graduates called for more curriculum attention on working with computers, planning and organisation, and leadership skills. More PBL graduates than non-PBL graduates indicated that they had learned profession-specific methods, communication skills and teamwork in medical school. Overall, the graduates appeared to be satisfied with their knowledge and skills. The results suggest that the PBL school provided better preparation with respect to several of the competencies. However, both PBL and non-PBL graduates identified deficits in their general competencies, such as working with computers and planning and organising work. These competencies should feature more prominently in undergraduate medical education.
A Generalized Measure for the Optimal Portfolio Selection Problem and its Explicit Solution
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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.
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.
Mikami, Katsunaka; Jorge, Ricardo E; Moser, David J; Arndt, Stephan; Jang, Mijin; Solodkin, Ana; Small, Steven L; Fonzetti, Pasquale; Hegel, Mark T; Robinson, Robert G
2014-01-01
This study examined the efficacy of antidepressant treatment for preventing the onset of generalized anxiety disorder (GAD) among patients with recent stroke. Of 799 patients assessed, 176 were randomized, and 149 patients without evidence of GAD at the initial visit were included in this double-blind treatment with escitalopram (N=47) or placebo (N=49) or non-blinded problem-solving therapy (PST; 12 total sessions; N=53). Participants given placebo over 12 months were 4.95 times more likely to develop GAD than patients given escitalopram and 4.00 times more likely to develop GAD than patients given PST. Although these results should be considered preliminary, the authors found that both escitalopram and PST were effective in preventing new onset of post-stroke GAD.
Algorithm for Solving a Generalized Mixed Equilibrium Problem with Perturbation in a Banach Space
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Kum Sangho
2010-01-01
Full Text Available Let be a real Banach space with the dual space . Let be a proper functional and let be a bifunction. In this paper, a new concept of -proximal mapping of with respect to is introduced. The existence and Lipschitz continuity of the -proximal mapping of with respect to are proved. By using properties of the -proximal mapping of with respect to , a generalized mixed equilibrium problem with perturbation (for short, GMEPP is introduced and studied in Banach space . An existence theorem of solutions of the GMEPP is established and a new iterative algorithm for computing approximate solutions of the GMEPP is suggested. The strong convergence criteria of the iterative sequence generated by the new algorithm are established in a uniformly smooth Banach space , and the weak convergence criteria of the iterative sequence generated by this new algorithm are also derived in a Hilbert space.
Normal Mode Analysis to a Poroelastic Half-Space Problem under Generalized Thermoelasticity
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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.
A generalized number theory problem applied to ideal liquids and to terminological lexis
Maslov, V. P.; Maslova, T. V.
2017-01-01
We consider the notion of number of degrees of freedom in number theory and thermodynamics. This notion is applied to notions of terminology such as terms, slogans, themes, rules, and regulations. Prohibitions are interpreted as restrictions on the number of degrees of freedom. We present a theorem on the small number of degrees of freedom as a consequence of the generalized partitio numerorum problem. We analyze the relationship between thermodynamically ideal liquids with the lexical background that a term acquires in the process of communication. Examples showing how this background may be enhanced are considered. We discuss the question of the coagulation of drops in connection with the forecast of analogs of the gas-ideal liquid phase transition in social-political processes.
A Generalized Mathematical Model for the Fracture Problem of the Suspended Highway
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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.
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.
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,
Goldberg, Sarah E.; Whittamore, Kathy H.; Harwood, Rowan H.; Bradshaw, Lucy E.; Gladman, John R. F.; Jones, Rob G.
2011-01-01
Background: a high prevalence of co-morbid mental health problems is reported among older adults admitted to general hospitals. Setting: an 1,800 bed teaching hospital. Design: consecutive general medical and trauma orthopaedic admissions aged 70 or older were screened for mental health problems. Those screening positive were invited to undergo further assessment, and were interviewed to complete a battery of health status measurements. Results: of 1,004 patients screened, 36% had no mental h...
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,
Teunissen, E.; Bavel, E. Van; Driessen Mareeuw, F.A. van den; Macfarlane, A.; Weel-Baumgarten, E.M. van; Muijsenbergh, M.E.T.C. van den; Weel, C. van
2015-01-01
OBJECTIVE: To explore the views and experiences of general practitioners (GPs) in relation to recognition, recording, and treatment of mental health problems of undocumented migrants (UMs), and to gain insight in the reasons for under-registration of mental health problems in the electronic medical
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
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
Overweight in adolescent, psychiatric inpatients: A problem of general or food-specific impulsivity?
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.
Generalized Supersoft Supersymmetry Breaking and a Solution to the μ Problem.
Nelson, Ann E; Roy, Tuhin S
2015-05-22
We propose the framework generalized supersoft supersymmetry breaking. "Supersoft" models, with D-type supersymmetry breaking and heavy Dirac gauginos, are considerably less constrained by the LHC searches than the well studied MSSM. These models also ameliorate the supersymmetric flavor and CP problems. However, previously considered mechanisms for obtaining a natural size Higgsino mass parameter (namely, μ) in supersoft models have been relatively complicated and contrived. Obtaining a 125 GeV for the mass of the lightest Higgs boson has also been difficult. Additional issues with the supersoft scenario arise from the fact that these models contain new scalars in the adjoint representation of the standard model, which may obtain negative squared-masses, breaking color and generating too large a T parameter. In this Letter, we introduce new operators into supersoft models which can potentially solve all these issues. A novel feature of this framework is that the new μ term can give unequal masses to the up and down type Higgs fields, and the Higgsinos can be much heavier than the Higgs boson without fine-tuning. However, unequal Higgs and Higgsino masses also remove some attractive features of supersoft supersymmetry.
Stein, Dan J; Lopez, Ana Garcia
2011-11-01
Disturbed sleep is a key symptom in major depressive disorder (MDD) and generalized anxiety disorder (GAD). First-line antidepressants, including the selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs), may have different effects on sleep. Data from 22 randomized, controlled trials comparing escitalopram with SSRIs, SNRIs, or placebo in the treatment of adult MDD or GAD were included. Both last observation carried forward (LOCF) and repeated measurements (MMRM) were used to analyze the sleep item of the Montgomery Åsberg Depression Rating Scale (MADRS) or Hamilton Anxiety Rating Scale (HAM-A) after 8 weeks of treatment. Sleep-related treatment-emergent adverse events were also compared across groups. For patients with MDD (n = 5133), the treatment difference on MADRS item 4 ("reduced sleep") was significantly in favor of escitalopram versus placebo (LOCF [P = 0.0017] and MMRM [P = 0.0002]), versus SSRIs (LOCF [P = 0.0020] and MMRM [P 0.0787]). For patients with GAD (n = 2052) the treatment difference in sleep symptoms measured by HAM-A item 4 ("insomnia") was significantly in favor of escitalopram versus placebo (LOCF [P = 0.0005] and MMRM [P insomnia as an adverse event after escitalopram was higher than placebo, similar to SSRIs, and lower than SNRIs. Additional research assessing the comparative effects of antidepressants with polysomnography is needed. In the interim, from a clinical perspective, escitalopram appears to be beneficial for the treatment of sleep problems in MDD and GAD.
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.
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.
Lower, Stephen K.
A brief overview of CHEMEX--a problem-solving, tutorial style computer-assisted instructional course--is provided and sample problems are offered. In CHEMEX, students receive problems in advance and attempt to solve them before moving through the computer program, which assists them in overcoming difficulties and serves as a review mechanism.…
Basten, Maartje; Tiemeier, Henning; Althoff, Robert R; van de Schoot, Rens; Jaddoe, Vincent W V; Hofman, Albert; Hudziak, James J; Verhulst, Frank C; van der Ende, Jan
2016-02-01
This study examined the stability of internalizing and externalizing problems from age 1.5 to 6 years, while taking into account developmental changes in the presentation of problems. The study comprised a population-based cohort of 7,206 children (50.4 % boys). At ages 1.5, 3, and 6 years, mothers reported on problem behavior using the Child Behavior Checklist/1.5-5 (CBCL/1.5-5). At each age we performed latent profile analysis on the CBCL/1.5-5 scales. Latent transition analysis (LTA) was applied to study the stability of problem behavior. Profiles of problem behavior varied across ages. At each age, 82-87 % of the children did not have problems whereas approximately 2 % showed a profile of co-occurring internalizing and externalizing problems. This profile was more severe (with higher scores) at 6 years than at earlier ages. A predominantly internalizing profile only emerged at 6 years, while a profile with externalizing problems and emotional reactivity was present at each age. LTA showed that, based on profiles at 1.5 and 3 years, it was difficult to predict the type of profile at 6 years. Children with a profile of co-occurring internalizing and externalizing problems early in life were most likely to show problem behavior at 6 years. This study shows that the presentation of problem behavior changes across the preschool period and that heterotypic continuity of problems is very common among preschoolers. Children with co-occurring internalizing and externalizing problems were most likely to show persisting problems. The use of evidence-based treatment for these young children may prevent psychiatric problems across the life course.
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.
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).
Leitner, Markus
In this article, we introduce the Generalized [Formula: see text]-Survivable Network Design Problem ([Formula: see text]-GSNDP) which has applications in the design of backbone networks. Different mixed integer linear programming formulations are derived by combining previous results obtained for the related [Formula: see text]-GSNDP and Generalized Network Design Problems. An extensive computational study comparing the correspondingly developed branch-and-cut approaches shows clear advantages for two particular variants. Additional insights into individual advantages and disadvantages of the developed algorithms for different instance characteristics are given.
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
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
A Generalization of the Aumann-Shapley Value for Risk Capital Allocation Problems
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
Health problems of victims before and after disaster: a longitudinal study in general practice.
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
Directory of Open Access Journals (Sweden)
Granville Sewell
2013-01-01
Full Text Available PDE2D is a general-purpose partial differential equation solver which solves very general systems of nonlinear, steady-state, time-dependent and eigenvalue PDEs in 1D intervals, general 2D regions (see Figure 1, and a wide range of simple 3D regions (see Figure 2, with general boundary conditions. It uses a collocation finite element method [2] for 3D problems, and either a collocation or Galerkin finite element method can be used for 1D and 2D problems. It has been sold commercially for 30 years, but recently a version has been made available, which can be downloaded at no cost from www.pde2d.com.
Directory of Open Access Journals (Sweden)
Vladimir V. Kozoderov
1998-01-01
Full Text Available The overall problem of global change is considered as the mathematical discrete dynamics discipline that deals with the sets, measures and metrics (SMM categories in information sub-spaces. The SMM conception enables to unify techniques of data interpretation and analysis and to explain how effectively the giant amounts of information from multispectral satellite radiometers and ground-based instruments are to be processed. It is shown that Prigogine's chaos/order theory and Kolmogorov's probability space are two milestones in understanding the predictability problems of global change. The essence of the problems is maintained to be in filtering out a “useful signal” that would spread from key regions of the globe as compared to their background. Global analysis, interpretation and modelling issues are outlined in the framework of incorrect mathematical problems and of the SMM categories, which contribute to solving the comparability problem for different sets of observations.
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.
Teunissen, Erik; Van Bavel, Eric; Van Den Driessen Mareeuw, Francine; Macfarlane, Anne; Van Weel-Baumgarten, Evelyn; Van Den Muijsenbergh, Maria; Van Weel, Chris
2015-06-01
To explore the views and experiences of general practitioners (GPs) in relation to recognition, recording, and treatment of mental health problems of undocumented migrants (UMs), and to gain insight in the reasons for under-registration of mental health problems in the electronic medical records. Qualitative study design with semi-structured interviews using a topic guide. Sixteen GPs in the Netherlands with clinical expertise in the care of UMs. GPs recognized many mental health problems in UMs. Barriers that prevented them from recording these problems and from delivering appropriate care were their low consultation rates, physical presentation of mental health problems, high number of other problems, the UM's lack of trust towards health care professionals, and cultural differences in health beliefs and language barriers. Referrals to mental health care organizations were often seen as problematic by GPs. To overcome these barriers, GPs provided personalized care as far as possible, referred to other primary care professionals such as social workers or mental health care nurses in their practice, and were a little less restrictive in prescribing psychotropics than guidelines recommended. GPs experienced a variety of barriers in engaging with UMs when identifying or suspecting mental health problems. This explains why there is a gap between the high recognition of mental health problems and the low recording of these problems in general practice files. It is recommended that GPs address mental health problems more actively, strive for continuity of care in order to gain trust of the UMs, and look for opportunities to provide mental care that is accessible and acceptable for UMs.
Directory of Open Access Journals (Sweden)
Marleen H.M. De Moor
2011-11-01
Full Text Available This study examined the heritability of problem drinking and investigated the phenotypic and genetic relationships between problem drinking and personality. It was conducted in a sample of 5,870 twins and siblings and 4,420 additional family members from the Netherlands Twin Register. Data on problem drinking (assessed with the AUDIT and CAGE; 12 items and personality (NEO-FFI; 60 items were collected in 2009/2010 through surveys. Factor analysis on the AUDIT and CAGE items showed that the items clustered on two separate but highly correlated (r=0.74 underlying factors. A higher order factor was extracted that reflected those aspects of problem drinking that are common to the AUDIT and CAGE , which showed a heritability of 40%. The correlations between problem drinking and the five dimensions of personality were small but significant, ranging from 0.06 for Extraversion to -0.12 for Conscientiousness. All personality dimensions (with broad-sense heritabilities between 32% and 55%, and some evidence for non-additive genetic influences were genetically correlated with problem drinking. The genetic correlations were small to modest (between |0.12-0.41|. Future studies with longitudinal data and DNA polymorphisms are needed to determine the biological mechanisms that underlie the genetic link between problem drinking and personality.
Miller-Graff, Laura E; Cater, Åsa Källström; Howell, Kathryn H; Graham-Bermann, Sandra A
2015-10-01
The goal of the current study was to examine the direct relationship between diverse types of childhood victimization and physical health problems in early adulthood, controlling for other common factors that contribute to physical health problems, including psychopathology and health risk behaviors. The associations between types of victimization (e.g., physical assault) and specific health problems (e.g., pain) were also examined. 2500 Swedish young adults reported on their exposure to victimization in childhood and their current mental and physical health as adults. Using multiple regression, results indicated that the amount of childhood victimization was a significant predictor of health problems in adulthood, controlling for the significant negative effects of health risk behaviors and mental health problems on physical health. Logistic regressions indicated that physical assaults and sexual abuse were associated with all types of health problems assessed. Sleep problems were associated with almost all types of victimization history. The long-term effects of childhood victimization on physical health in adulthood are serious and warrant significant attention. Primary care providers should include assessments of past victimization as one way of screening for health risk. Health providers should also consider multiple points of intervention that may help to reduce physical illness. For example, providing a mental health intervention or social service support related to victimization experiences may not only address these difficulties, but also more broadly impact physical health as well. Copyright © 2015 Elsevier Inc. All rights reserved.
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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.
A Simulated Annealing method to solve a generalized maximal covering location problem
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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.
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.
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....
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.
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Milena Netka
2009-01-01
Full Text Available The paper is concerned with weak solutions of a generalized Cauchy problem for a nonlinear system of first order differential functional equations. A theorem on the uniqueness of a solution is proved. Nonlinear estimates of the Perron type are assumed. A method of integral functional inequalities is used.
Bogan, Yu A.
2017-10-01
By means of a new approach, the general boundary value problem for a higher order elliptic equation with two independent variables, and a normal set of boundary conditions and simple complex characteristics is reduced to the Fredholm system of integral equations in a bounded region with a smooth boundary.
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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.
Nygaard, Egil; Jensen, Tine K.; Dyb, Grete
2012-01-01
The aim of this study was to evaluate the structure of posttraumatic stress reaction factors and their relation to general mental health problems in Norwegian children exposed to the tsunami on December 26, 2004. A total of 133 children and adolescents (ages 6-17) were interviewed 10 months posttsunami using the UCLA PTSD Reaction Index, and 104…
The Role of General Physical Education in Solution of Health Problem of Russia’s Population
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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.
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
Twenty Years of General Education in China: Progress, Problems, and Solutions
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…
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.
A generalization of Schauder's theorem and its application to Cauchy-Kovalevskaya problem
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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.
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)
2012-03-01
uncertainties. Pioneers in the study of optimal filtering were Norbert Wiener (1894-1964) in the 1940’s [84] and Ruldolf Kalman and Richard Bucy in the 1950...in this research and will be presented more thoroughly in the next subsection. 67 2.4.2 Generalized Polynomial Chaos. In 1938 Norbert Wiener introduced...Generalized Poly- nomial Chaos for Arbitrary Probability Measures”. SIAM Journal on Scientific Computing, 28(3):901–928, 2006. 83. Wiener , Norbert . “The
General linear methods and friends: Toward efficient solutions of multiphysics problems
Sandu, Adrian
2017-07-01
Time dependent multiphysics partial differential equations are of great practical importance as they model diverse phenomena that appear in mechanical and chemical engineering, aeronautics, astrophysics, meteorology and oceanography, financial modeling, environmental sciences, etc. There is no single best time discretization for the complex multiphysics systems of practical interest. We discuss "multimethod" approaches that combine different time steps and discretizations using the rigourous frameworks provided by Partitioned General Linear Methods and Generalize-structure Additive Runge Kutta Methods..
Estimates for a general fractional relaxation equation and application to an inverse source problem
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...
Tarber, Christel; Frostholm, Lisbeth
2014-01-01
Common mental disorders often go undetected in primary care. Sharpening general practitioners' (GPs') attention to potential signs thereof is therefore crucial. This conversation-analytic study arises from the observation that the consideration of psychological problems in new-concern visits can be achieved by way of 'gradual topic emergence'. This entails that the problem is not presented directly, but adjunct to somatic symptoms, and is hinted at by way of generic, ambiguous complaints, and furthermore by expressions of frustration and uncertainty and talk about lifeworld problems. It is argued that these materials are 'trouble-premonitory, alerting the GP to the presence of an underlying problem that can then be addressed throughfurther inquiry. The patient logic behind this approach is to assure the GP's recipiency and thus ratification of the problem's medical legitimacy. It allows the patient to introduce a potentially delicate problem 'off the record, thus guarding the patient against the loss of face that could resultfrom no uptake by the GP. The results of the study point to the importance of GPs being receptive to such interactional clues to psychological problems provided by patients.
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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.
Balder, E.J.
1984-01-01
This note presents a new, quick approach to existence results without convexity conditions for optimal control problems with singular components in the sense of [11.], 438–485). Starting from the resolvent kernel representation of the solutions of a linear integral equation, a version of Fatou's
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 ...
A note on hierarchical hubbing for a generalization of the VPN problem
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].
A note on hierarchical hubbing for a generalization of the VPN problem
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
A note on hierarchical hubbing for a generalization of the VPN problem
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
A note on hierarchical hubbing for a generalization of the VPN problem
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
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
Bazo, Plácido; Rodríguez, Romén; Fumero, Dácil
2016-01-01
In this paper, we will introduce an innovative software platform that can be especially useful in a Content and Language Integrated Learning (CLIL) context. This tool is called Vocabulary Notebook, and has been developed to solve all the problems that traditional (paper) vocabulary notebooks have. This tool keeps focus on the personalisation of…
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...... works well on both serial and parallel computers, and good scalability of the algorithm is obtained. (C) 2001 IMACS. Published by Elsevier Science B.V. All rights reserved.......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...... propose a new algorithm of this kind which is well suited for the SCF method, since the accuracy of the eigensolution is gradually improved along with the outer SCF-iterations. Best efficiency is obtained for small-block-size iterations, and the algorithm is highly memory efficient. The implementation...
Foot problems in children presented to the general practitioner: a comparison between 1987 and 2001.
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
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
Common mental health problems in immigrants and refugees: general approach in primary care.
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
Common mental health problems in immigrants and refugees: general approach in primary care
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
Directory of Open Access Journals (Sweden)
Zhaoli Ma
2012-01-01
Full Text Available We introduce an iterative scheme for finding a common element of the set of solutions of generalized mixed equilibrium problems and the set of fixed points for countable families of total quasi-ϕ-asymptotically nonexpansive mappings in Banach spaces. We prove a strong convergence theorem of the iterative sequence generated by the proposed iterative algorithm in an uniformly smooth and strictly convex Banach space which also enjoys the Kadec-Klee property. The results presented in this paper improve and extend some recent corresponding results.
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....
Indian Academy of Sciences (India)
Page S20: NMR compound 4i. Page S22: NMR compound 4j. General: Chemicals were purchased from Fluka, Merck and Aldrich Chemical Companies. All the products were characterized by comparison of their IR, 1H NMR and 13C NMR spectroscopic data and their melting points with reported values. General procedure ...
Pannier, S.; Waurick, M.; Graf, W.; Kaliske, M.
2013-05-01
The present paper is about data corrupted by both aleatoric and epistemic uncertainty. A unification of randomness, which represents aleatoric uncertainty, and fuzziness, which represents epistemic uncertainty, is dicussed in detail. As a result, the main uncertainty characteristics, i.e., variability, incompleteness and imprecision, can be described. With a focus on engineering problems the aim is to bridge the imprecision of data to the decision making process. Suitable fields of applications are highlighted; remarks on the numerical treatment are given.
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
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.
Sobolev spaces, their generalizations and elliptic problems in smooth and Lipschitz domains
Agranovich, Mikhail S
2015-01-01
This book, which is based on several courses of lectures given by the author at the Independent University of Moscow, is devoted to Sobolev-type spaces and boundary value problems for linear elliptic partial differential equations. Its main focus is on problems in non-smooth (Lipschitz) domains for strongly elliptic systems. The author, who is a prominent expert in the theory of linear partial differential equations, spectral theory, and pseudodifferential operators, has included his own very recent findings in the present book. The book is well suited as a modern graduate textbook, utilizing a thorough and clear format that strikes a good balance between the choice of material and the style of exposition. It can be used both as an introduction to recent advances in elliptic equations and boundary value problems, and as a valuable survey and reference work. It also includes a good deal of new and extremely useful material not available in standard textbooks to date. Graduate and post-graduate student...
The Problems and Prospects of General Education in an Information Society
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.
Children with Generalized Anxiety Disorder Do Not Have Peer Problems, Just Fewer Friends
Scharfstein, Lindsay; Alfano, Candice; Beidel, Deborah; Wong, Nina
2011-01-01
A common assumption is that all youth with anxiety disorders (AD) experience impaired peer relationships relative to healthy control children. Social impairments have been identified among youth with certain AD (e.g., social anxiety disorder; SAD), but less is known about the peer relationships of children with generalized anxiety disorder (GAD).…
Czech Academy of Sciences Publication Activity Database
Daněk, Josef; Hlaváček, Ivan; Nedoma, Jiří
2005-01-01
Roč. 68, č. 3 (2005), s. 271-300 ISSN 0378-4754 R&D Projects: GA MPO FT-TA/087 Keywords : domain decomposition * unilateral contact * Tresca's friction model * formulation in displacements * linear finite elements Subject RIV: BA - General Mathematics Impact factor: 0.554, year: 2005
Navajo Community College Funding Problems. Report by the Comptroller General of the United States.
Comptroller General of the U.S., Washington, DC.
Funding for the Navajo Community College was reviewed by the Comptroller General of the United States to determine if the Bureau of Indian Affairs' (BIA) regulations and method of computing full-time equivalent enrollments were consistent with the Tribally Controlled Community College Assistance Act of 1978 (P.L. 95-471). The investigation…
The CTRW in finance: Direct and inverse problems with some generalizations and extensions
Masoliver, Jaume; Montero, Miquel; Perello, Josep; Weiss, George H.
2003-01-01
We study financial distributions within the framework of the continuous time random walk (CTRW). We review earlier approaches and present new results related to overnight effects as well as the generalization of the formalism which embodies a non-Markovian formulation of the CTRW aimed to account for correlated increments of the return.
Ringoot, A P; Jansen, P W; Rijlaarsdam, J; So, P; Jaddoe, V W V; Verhulst, F C; Tiemeier, H
2017-02-01
Problem behavior of young children is generally not assessed with structured child interviews. This paper examined how information about problem behavior, obtained by structured interviews with six-year-old children, relates to DSM-disorders obtained from parents and to treatment referral. In a population-based cohort, caregivers of 1084 young children (mean age 6.7 years) were interviewed with the DSM-based Diagnostic Interview Schedule-Young Child version (DISC-YC), and they scored the Child Behavior Checklist (CBCL). Children themselves were interviewed about problem behavior using the semi-structured Berkeley Puppet Interview (BPI). Information regarding treatment referral to mental health services was obtained by parent-reported questionnaire when children were on average eight years old. DSM-disorders and CBCL problems in the clinical range were cross-sectionally associated with higher levels of child self-reported problems. Associations were strongest in the externalizing domain (e.g. DISC-YC externalizing disorders with BPI externalizing scores: F(1, 416)=19.39, Pchildren should be an integral part of child assessment. This approach may contribute to a better understanding of child development and may predict future problems. Copyright Â© 2016 Elsevier Masson SAS. All rights reserved.
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 groups ( 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 group than in young-aged group
Tracey, T J; Rounds, J; Gurtman, M
1996-10-01
The relation of the general factor of the Inventory of Interpersonal Problems (IIP, Horowitz, Rosenberg, Baer, Ureno, & Villasenor, 1988) to several response set and personality measures as well its relation to the circumplex structure was examined. The correlation of the IIP general factor to the personality and response measures was examined on a sample of 105 undergraduates. The general factor was significantly related to a symptom severity measure as well as negative affectivity and self-deception, supporting its interpretation in a substantive manner. Subsequently, the circular structure of the IIP was examined as it varied across different levels of the general factor in a sample of 1093 college students. The sample was divided into five relatively equally sized groups on the general factor. At each level, the IIP scales were examined for their circularity and circular variance accounted for to determine if the structure of the IIP scales resembled a cylinder, a sphere, or a truncated cone. Evaluations of both the circular order model and the circumplex model supported the circularity of the IIP at all levels of the general factor. Support for the cone structure was supported for lower levels of the general distress factor but higher levels did not demonstrate the expected increased correlational dispersion.
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
ZERO-2 - a general purpose computer program for fluid-structure interaction problems
International Nuclear Information System (INIS)
Brusa, L.; Ciacci, R.; Greco, A.
1983-01-01
The objective of this paper is to present a description of the main features of the finite element code ZERO-2, which allows the static and dynamic analysis of axisymmetric structures with non symmetrical loads, taking into account dynamic fluid-structure interaction effects. The structure is assumed to have an elastic behaviour and the acoustic approximation is made for the fluid. The liquid is considered as compressible and sloshing effects may be taken into account. The structural displacement field, the fluid pressure distribution and the applied loads are expanded as a Fourier series to describe circumferential variations, so that the problem is reduced to the solution of decoupled equations for the amplitude for the harmonic terms. The structure may be composed of thin and thick elements characterized by different nodal degrees of freedom. The static analysis may be performed with thermal loads and distributed or concentrated froces on the structure. The dynamic loading may consist of distributed or concentrated forces on the structure, prescribed pressures on some part of the fluid surface, prescribed forces on the structure, prescribed pressures on some part of the fluid surface, prescribed nodal displacements and seismic ground acceleration. The seismic response may be computed taking into account multiple support excitations acting both on the structure and on the fluid. The dynamic equilibrium equations are solved by means of the modal superposition method and in the case of fluid-structure interaction problems, the normal modes of the coupled system are used. One of the major problems to be considered when using modal superposition method, is the choice of an appropriate number of modes to have accurate results. (orig./GL)
Acceleration of the generalized global basis (GGB) method for nonlinear problems
Waisman, Haim; Fish, Jacob; Tuminaro, Raymond S.; Shadid, John N.
2005-11-01
Two heuristic strategies intended to enhance the performance of the generalized global basis (GGB) method [H. Waisman, J. Fish, R.S. Tuminaro, J. Shadid, The Generalized Global Basis (GGB) method, International Journal for Numerical Methods in Engineering 61(8), 1243-1269] applied to nonlinear systems are presented. The standard GGB accelerates a multigrid scheme by an additional coarse grid correction that filters out slowly converging modes. This correction requires a potentially costly eigen calculation. This paper considers reusing previously computed eigenspace information. The GGB α scheme enriches the prolongation operator with new eigenvectors while the modified method (MGGB) selectively reuses the same prolongation. Both methods use the criteria of principal angles between subspaces spanned between the previous and current prolongation operators. Numerical examples clearly indicate significant time savings in particular for the MGGB scheme.
International Nuclear Information System (INIS)
Xie Yushu; Li Fatao
2010-01-01
The objective of this paper is to study thermal inertia effect due to the fact of the properties of the hyperbolic equations based on LS theory in generalized thermoelasticity. Simulations in a 2D hollow cylinder for uncoupled dynamic thermal stresses and thermal displacements were predicted by use of finite element method with Newmark algorithm. The thermal inertia effect on LS theory in rapid transient heat transfer process is also investigated in comparison with in steady heat transfer process. When different specific heat capacity is chosen, dynamic thermal stresses appear different types of vibration, in which less heat capacity causes more violent dynamic thermal stresses because of the thermal inertia effect. Both dynamic thermal stresses and thermal displacements in rapid transient heat transfer process have the larger amplitude and higher frequency than in steady heat transfer process due to thermal inertia from the results of simulation, which is consistent with the nature of the generalized thermoelasticity.
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
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.
Inverse backscattering problem for the generalized nonlinear Schroedinger operator in two dimensions
International Nuclear Information System (INIS)
Serov, V; Sandhu, J
2010-01-01
The inverse Born approximation is studied for the generalized nonlinear two-dimensional Schroedinger equation -Δu +Σ l = 0 m α l |u| l u = k 2 u, where the real-valued unknown potentials α l belong to L p c omp(R 2 ) for some 2 ≤ p ≤ ∞ and their Fourier transforms belong to the space L s (R 2 ) for some 1 t while the other being a continuous function.
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.
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...
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
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.
Hintermair, Manfred
2013-01-01
In this study, behavioral problems of deaf and hard-of-hearing (D/HH) school-aged children are discussed in the context of executive functioning and communicative competence. Teachers assessed the executive functions of a sample of 214 D/HH students from general schools and schools for the deaf, using a German version of the Behavior Rating Inventory of Executive Functions (BRIEF-D). This was complemented by a questionnaire that measured communicative competence and behavioral problems (German version of the Strengths and Difficulties Questionnaire; SDQ-D). The results in nearly all the scales show a significantly higher problem rate for executive functions in the group of D/HH students compared with a normative sample of hearing children. In the D/HH group, students at general schools had better scores on most scales than students at schools for the deaf. Regression analysis reveals the importance of executive functions and communicative competence for behavioral problems. The relevance of the findings for pedagogical work is discussed. A specific focus on competencies such as self-efficacy or self-control in educational concepts for D/HH students seems to be necessary in addition to extending language competencies.
Collaborative activities for solving multi-step problems in general chemistry
Directory of Open Access Journals (Sweden)
Luis Antonio Tortajada-Genaro
2014-12-01
Full Text Available The learning of solving multi-step problems is a relevant objective in chemical education for engineering students. In these questions, after analyzing initial data, a complex reasoning and an elaborated mathematical procedure is needed to achieve the correct numerical answer. But, many students are able to effectively use algorithms even with a lack of meaningful understanding of involved chemical concepts. This paper reports the application of some collaborative actions in order to induce a complete acquisition of problem solving skills. The studied approaches, performed inside and outside the classroom, are classified in low-collaborative and high-collaborative activities depending on the relative participation of instructor/students in their development. The critical description of proposed methodology and the produced outcomes are exposed. The contribution of each major reasoning mode (model, rule or case based employed in these activities is analyzed. Also, the perception of students is evaluated based on the data provided by direct observation and a specific survey with Likert-scale and open-ended questions. The results indicate that the changes of teaching to a more conceptual orientation lead a deeper understanding, minimizing misconceptions or a rote learning.
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)
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.
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.
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.
A Family of Multipoint Flux Mixed Finite Element Methods for Elliptic Problems on General Grids
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.
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.
Directory of Open Access Journals (Sweden)
Thanin Sitthiwirattham
2012-01-01
Full Text Available By using Krasnoselskii's fixed point theorem, we study the existence of positive solutions to the three-point summation boundary value problem Δ2u(t-1+a(tf(u(t=0, t∈{1,2,…,T}, u(0=β∑s=1ηu(s, u(T+1=α∑s=1ηu(s, where f is continuous, T≥3 is a fixed positive integer, η∈{1,2,...,T-1}, 0<α<(2T+2/η(η+1, 0<β<(2T+2-αη(η+1/η(2T-η+1, and Δu(t-1=u(t-u(t-1. We show the existence of at least one positive solution if f is either superlinear or sublinear.
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
microTaboo: a general and practical solution to the k-disjoint problem.
Al-Jaff, Mohammed; Sandström, Eric; Grabherr, Manfred
2017-05-02
A common challenge in bioinformatics is to identify short sub-sequences that are unique in a set of genomes or reference sequences, which can efficiently be achieved by k-mer (k consecutive nucleotides) counting. However, there are several areas that would benefit from a more stringent definition of "unique", requiring that these sub-sequences of length W differ by more than k mismatches (i.e. a Hamming distance greater than k) from any other sub-sequence, which we term the k-disjoint problem. Examples include finding sequences unique to a pathogen for probe-based infection diagnostics; reducing off-target hits for re-sequencing or genome editing; detecting sequence (e.g. phage or viral) insertions; and multiple substitution mutations. Since both sensitivity and specificity are critical, an exhaustive, yet efficient solution is desirable. We present microTaboo, a method that allows for efficient and extensive sequence mining of unique (k-disjoint) sequences of up to 100 nucleotides in length. On a number of simulated and real data sets ranging from microbe- to mammalian-size genomes, we show that microTaboo is able to efficiently find all sub-sequences of a specified length W that do not occur within a threshold of k mismatches in any other sub-sequence. We exemplify that microTaboo has many practical applications, including point substitution detection, sequence insertion detection, padlock probe target search, and candidate CRISPR target mining. microTaboo implements a solution to the k-disjoint problem in an alignment- and assembly free manner. microTaboo is available for Windows, Mac OS X, and Linux, running Java 7 and higher, under the GNU GPLv3 license, at: https://MohammedAlJaff.github.io/microTaboo.
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
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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
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
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
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
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)
The general problem of the motion of coupled rigid bodies about a fixed point
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.
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.
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
2018-01-01
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 fully understood, particularly in younger populations. We investigated whether polygenic scores of five psychiatric disorders and educational attainment are related to emotional and behaviour problems during early childhood. From the Generation R Study, we included participants with available genotype data and behavioural problems measured with the Child Behavior Checklist (CBCL) at the age of 3 (n = 1,902), 6 (n = 2,202) and 10 years old (n = 1,843). Polygenic scores were calculated for five psychiatric disorders and educational attainment. These polygenic scores were tested for an association with the broadband internalizing and externalizing problem scales and the specific CBCL syndrome scale scores. Analysis of the CBCL broadband scales showed that the schizophrenia polygenic score was associated with significantly higher internalizing scores at 3, 6 and 10 years and higher externalizing scores at age 3 and 6. The educational attainment polygenic score was associated with lower externalizing scores at all time points and lower internalizing scores at age 3. No associations were observed for the polygenic scores of bipolar disorder, major depressive disorder and autism spectrum disorder. Secondary analyses of specific syndrome scores showed that the schizophrenia polygenic score was strongly related to the Thought Problems scores. A negative association was observed between the educational attainment polygenic score and Attention Problems scores across all age groups. Polygenic scores for adult psychiatric disorders and educational attainment are associated with variation in emotional and behavioural problems already at a very early age. © 2017 Association for Child and
Johannessen, Håkon A; Sterud, Tom
2017-10-01
A growing number of longitudinal studies report associations between adverse psychosocial factors at work and sleep problems. However, the evidence regarding the direction of these associations and the effects of changes in exposure across time is limited. This study examined the plausibility of normal, reverse, and reciprocal associations between ten psychosocial factors at work and sleep problems. In addition, we analyzed if reduced exposure across time had the anticipated result of reducing the risk of sleep problems. Randomly drawn from the general working-age population, the cohort comprised respondents with an active employee relationship in 2009 and 2013 (N = 5760). Exposures and outcome were measured on two occasions separated by 4 years. We computed several sex-stratified logistic regression models with adjustments for various plausible confounders. We found support for the commonly hypothesized unidirectional forward associations between psychosocial factors at work and sleep problems among women only. Among men, psychosocial stressors at work and sleep problems were reciprocally and reversely related. Nevertheless, reduced exposure levels across time pertaining to effort-reward imbalance (OR = 0.36; 95% CI = 0.19-0.69) and lack of social support (OR = 0.55; 95% CI = 0.32-0.93) among men, and work-family imbalance (OR = 0.26; 95% CI = 0.15-0.46) among women were associated with a robust significant lower risk of sleep problems compared to those in the stable high exposure groups. The study results suggest that preventive measures targeting effort-reward imbalance and lack of social support among men, and work-family imbalance among women, might contribute to reduce the risk of troubled sleep among employees.
Chen, S.; Indrei, E.
2015-04-01
This paper concerns the regularity and geometry of the free boundary in the optimal partial transport problem for general cost functions. More specifically, we prove that a C1 cost implies a locally Lipschitz free boundary. As an application, we address a problem discussed by Caffarelli and McCann [1] regarding cost functions satisfying the Ma-Trudinger-Wang condition (A3): if the non-negative source density is in some Lp (Rn) space for p ∈ (n + 1/2, ∞ ] and the positive target density is bounded away from zero, then the free boundary is a semiconvex Cloc1,α hypersurface. Furthermore, we show that a locally Lipschitz cost implies a rectifiable free boundary and initiate a corresponding regularity theory in the Riemannian setting.
Bouchaud, Jean-Philippe; Sornette, Didier
1994-01-01
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 processe...
Directory of Open Access Journals (Sweden)
2009-03-01
Full Text Available We introduce a new approximation scheme combining the viscosity method with parallel method for finding a common element of the set of solutions of a generalized equilibrium problem and the set of fixed points of a family of finitely strict pseudocontractions. We obtain a strong convergence theorem for the sequences generated by these processes in Hilbert spaces. Based on this result, we also get some new and interesting results. The results in this paper extend and improve some well-known results in the literature.
International Nuclear Information System (INIS)
Aleixo, A N F; Balantekin, A B
2010-01-01
We solve the normal ordering problem for the ladder operators B-hat + and B-hat - for strings in the form (B-hat + r B-hat - s ) n for supersymmetric and shape-invariant potential systems, with r, s and n positive integers. We provide exact and explicit expressions for their normal form N{(B-hat + r B-hat - s ) n }, where N{...} all B-hat - are at the right side, and find that the solution involves an expansion coefficients sequence which, for r, s > 1, corresponds to the generalization, for any shape-invariant potential system, of the classical Stirling and Bell numbers. We show that these numbers are obtained for families of polynomials generated with parameters related to the forms of the supersymmetric partner potentials. We apply the general formalism to Poeschl-Teller, Morse, Scarf and self-similar potential systems.
Szeto, Alan Ka-Fai
This study explored how undergraduate students in a new problem-centered General Chemistry Laboratory curriculum achieved cognitive growth. The new curriculum had three instructional segments: the highly-structured, semi-structured, and open-ended segments. The pedagogical approaches adopted were expository, guided-inquiry, and open-inquiry styles, respectively. Sixty-seven first-year undergraduate students who enrolled in the course in Spring semester, 2000, at Columbia University and three Ph.D.-level chemistry experts were included in the study. A qualitative approach was used including data collection through "think-aloud" problem solving; however, quantitative data such as test scores were also used. The findings from this study confirmed that chemistry experts possessed sophisticated and domain-specific conceptual knowledge structures; they mobilized and applied conceptual knowledge in conjunction with use of heuristics, tacit knowledge, and experience in authentic problem solving. They validated the new curriculum design in preparing students for inquiry-type of problem solving. For novices, solving of semi-structured before ill-structured problems had a positive effect on the solvers' chance of success in solving the latter type of problems as their abilities to mobilize and apply conceptual knowledge and use effective strategies appeared to be critical for successful problem solving. Students in the new course curriculum had grown cognitively as evidenced by their performance on the Case Study projects and Final Examination. High academic achievers were found to perform well independently while the medium and relatively low academic achievers should benefit from sustained and intensive instruction. It is proposed that ill-structured problems should be used to assess and identify the best from the better students. Finally, it was found that no significant change in students' attitudes had resulted from their curriculum experience. Gender and cognitive style
A General T-Matrix Approach Applied to Two-Body and Three-Body Problems in Cold Atomic Gases
International Nuclear Information System (INIS)
Cui, X.
2012-01-01
We propose a systematic T-matrix approach to solve few-body problems with s-wave contact interactions in ultracold atomic gases. The problem is generally reduced to a matrix equation expanded by a set of orthogonal molecular states, describing external center-of-mass motions of pairs of interacting particles; while each matrix element is guaranteed to be finite by a proper renormalization for internal relative motions. This approach is able to incorporate various scattering problems and the calculations of related physical quantities in a single framework, and also provides a physically transparent way to understand the mechanism of resonance scattering. For applications, we study two-body effective scattering in 2D-3D mixed dimensions, where the resonance position and width are determined with high precision from only a few number of matrix elements. We also study three fermions in a (rotating) harmonic trap, where exotic scattering properties in terms of mass ratios and angular momenta are uniquely identified in the framework of T-matrix. (author)
Sanders, Stephanie A; Hill, Brandon J; Janssen, Erick; Graham, Cynthia A; Crosby, Richard A; Milhausen, Robin R; Yarber, William L
2015-09-01
Condom-associated erection problems (CAEP) are an underestimated factor related to inconsistent or incomplete male condom use. The underlying mechanisms of CAEP are not understood, and whether men who report these difficulties are also likely to experience erectile problems in situations when condoms are not used has not been studied. The aim of the study was to investigate, in a sample of condom-using young, heterosexual men (aged 18-24 years), whether men who report CAEP are more likely to (i) have erection problems when not using condoms and (ii) meet criteria for erectile dysfunction. A total of 479 men recruited online completed the International Index of Erectile Function (IIEF-5) and answered questions about erection problems experienced when using and not using condoms during the last 90 days. Demographic, sexual experience, and health status variables were investigated as correlates. Self-reported frequency of erection loss during condom application or during penile-vaginal intercourse (PVI) in the past 90 days and IIEF-5 scores. Of the men, 38.4% were classified in the no CAEP group, 13.8% as having CAEP during condom application, 15.7% as having CAEP during PVI, and 32.2% as having CAEP during both condom application and PVI. Men reporting any form of CAEP were significantly more likely than men reporting no CAEP to also report erection difficulties during sexual activity when not using condoms. Men who reported CAEP during PVI only or during both application and PVI scored significantly lower on the IIEF-5 than men without CAEP. The findings suggest that men who report CAEP are also more likely to experience more generalized erection difficulties. Clinicians should assess whether men using condoms experience CAEP and where appropriate, refer for psychosexual therapy or provide condom skills education. © 2015 International Society for Sexual Medicine.
Hu, Sheng-Long; Huang, Zheng-Hai; Chen, Jein-Shan
2009-08-01
In this paper, we propose a new family of NCP-functions and the corresponding merit functions, which are the generalization of some popular NCP-functions and the related merit functions. We show that the new NCP-functions and the corresponding merit functions possess a system of favorite properties. Specially, we show that the new NCP-functions are strongly semismooth, Lipschitz continuous, and continuously differentiable; and that the corresponding merit functions have SC1 property (i.e., they are continuously differentiable and their gradients are semismooth) and LC1 property (i.e., they are continuously differentiable and their gradients are Lipschitz continuous) under suitable assumptions. Based on the new NCP-functions and the corresponding merit functions, we investigate a derivative free algorithm for the nonlinear complementarity problem and discuss its global convergence. Some preliminary numerical results are reported.
Directory of Open Access Journals (Sweden)
Saewan Siwaporn
2011-01-01
Full Text Available Abstract In this article, we introduce a new hybrid projection iterative scheme based on the shrinking projection method for finding a common element of the set of solutions of the generalized mixed equilibrium problems and the set of common fixed points for a pair of asymptotically quasi-ϕ-nonexpansive mappings in Banach spaces and set of variational inequalities for an α-inverse strongly monotone mapping. The results obtained in this article improve and extend the recent ones announced by Matsushita and Takahashi (Fixed Point Theory Appl. 2004(1:37-47, 2004, Qin et al. (Appl. Math. Comput. 215:3874-3883, 2010, Chang et al. (Nonlinear Anal. 73:2260-2270, 2010, Kamraksa and Wangkeeree (J. Nonlinear Anal. Optim.: Theory Appl. 1(1:55-69, 2010 and many others. AMS Subject Classification: 47H05, 47H09, 47J25, 65J15.
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.
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Álvaro Bernal
2014-01-01
Full Text Available Numerical methods are usually required to solve the neutron diffusion equation applied to nuclear reactors due to its heterogeneous nature. The most popular numerical techniques are the Finite Difference Method (FDM, the Coarse Mesh Finite Difference Method (CFMD, the Nodal Expansion Method (NEM, and the Nodal Collocation Method (NCM, used virtually in all neutronic diffusion codes, which give accurate results in structured meshes. However, the application of these methods in unstructured meshes to deal with complex geometries is not straightforward and it may cause problems of stability and convergence of the solution. By contrast, the Finite Element Method (FEM and the Finite Volume Method (FVM are easily applied to unstructured meshes. On the one hand, the FEM can be accurate for smoothly varying functions. On the other hand, the FVM is typically used in the transport equations due to the conservation of the transported quantity within the volume. In this paper, the FVM algorithm implemented in the ARB Partial Differential Equations solver has been used to discretize the neutron diffusion equation to obtain the matrices of the generalized eigenvalue problem, which has been solved by means of the SLEPc library.
Chen, Wei; Tsui, Kwok-Leung; Allen, Janet K.; Mistree, Farrokh
1994-01-01
In this paper we introduce a comprehensive and rigorous robust design procedure to overcome some limitations of the current approaches. A comprehensive approach is general enough to model the two major types of robust design applications, namely, robust design associated with the minimization of the deviation of performance caused by the deviation of noise factors (uncontrollable parameters), and robust design due to the minimization of the deviation of performance caused by the deviation of control factors (design variables). We achieve mathematical rigor by using, as a foundation, principles from the design of experiments and optimization. Specifically, we integrate the Response Surface Method (RSM) with the compromise Decision Support Problem (DSP). Our approach is especially useful for design problems where there are no closed-form solutions and system performance is computationally expensive to evaluate. The design of a solar powered irrigation system is used as an example. Our focus in this paper is on illustrating our approach rather than on the results per se.
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.
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
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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.
Leutgeb, R; Mahler, C; Laux, G; Weschnetz, Artenetz; Szecsenyi, J
2009-01-01
The German federal Health Insurance law to strengthen competition between the pharmaceutical companies commits pharmacies to hand out drugs from discount contract drug suppliers of a patient's health insurance company. Thus patients are confronted with constantly changing drug packets. This study aimed at exploring whether patients have been properly informed about the new discount contracts and if they have experienced changes and problems in their long- term medications. Between May and June 2008 male and female patients older than 50 years who had a statutory health insurance and had been diagnosed with coronary heart disease for at least one year answered a standardized questionnaire filled in by doctors' assistants or general practitioners in the doctors' network "Weschnitztal". Of the 188 patients participated in this study 63,8% were informed about health insurance discount contracts. 31,3% of the patients reported that a positive effect due to the discount contracts was that they were discharged from paying the drug prescription fee, 22,2% mentioned that cost saving for the health insurance could also be positive. 120 patients (63,8%) knew that the names of their long-term drugs could change.101 of the questioned patients (53,7%) identified a change in their long-term drugs, 51,5% felt insecure about the permanent changes. 21,7% experienced adverse e effects due to the new drugs. 19% of the patients had serious problems regarding medication intake. This study demonstrates that the information which patients have on the new health insurance law is not adequate enough. Many of them felt insecure because of the changes of long-term medications. One fifth of the patients reported errors in their drug intake or their confusion about their drugs. There is a high risk that these circumstances may trigger further diseases or complications. The cost savings as intended by the health insurance companies may therefore not be achieved by discount contracts.
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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
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Gao Feng
2017-01-01
Full Text Available In this paper we address the general fractional calculus of Liouville-Weyl and Liouville-Caputo general fractional derivative types with non-singular power-law kernel for the first time. The Fourier transforms and the anomalous diffusions are discussed in detail. The formulations are adopted to describe complex phenomena of the heat transfer problems.
DEFF Research Database (Denmark)
Romelsjö, A; Hasin, D; Hilton, M
1992-01-01
working conditions and subsequent risk of severe medical alcohol-related problems, but the precision of the estimates was low due to low number of cases. The odds ratio was 6.18 (95% confidence interval 1.86, 20.61) for twisted working positions and 6.74 (95% confidence interval 1.67, 27.19). Previous...... unemployment among males was associated with increased risk for high alcohol consumption, with an odds ratio of 5.71 (95% CI 1.39, 15.97) among those who had been unemployed more than once, and 1.67 (95% CI 0.76, 3.64) among those who had been unemployed once during the previous 5 years. Those and other......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...
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.
Chorwe-Sungani, G; Shangase, N
2013-12-01
Therapeutic commitment of general nurses influences their provision of mental health care to clients. It is the general nurses' predisposition for working therapeutically with clients who have mental health problems (MHPs). In Malawi, general nurses are the majority of health care professionals who care for people living with HIV/AIDS (PLWHA) and they are expected to deal with the mental health problems of these patients. The provision of mental health care to PLWHA is vital because apart from the physical illnesses associated with the virus, these people are also affected by mental health problems. However, most general nurses, feel neither confident nor competent when dealing with the mental health problems of their clients in Malawi. This may negatively influence their therapeutic commitment in dealing with mental health problems of PLWHA. However, therapeutic commitment of general nurses in providing mental health care to PLWHA in Malawi remains unknown. The study used a quantitative descriptive survey design. a convenient sample comprising of 136 general nurses was used and data was collected using Mental Health Problems Perception Questionnaire. Permission to use the tool in this study was granted by Prof. Lauder. Ethical approval to conduct the study was granted by Ethics Committees at University of KwaZulu Natal and University of Malawi. Data were analysed using Statistical Package for Social Sciences version 15.0. The study findings revealed that there is a linear relationship between general nurses' levels of knowledge and skills and their therapeutic commitment (r=.40, n=136, p<.05) to provide mental health care of PLWHA. This study suggests general nurses' levels of therapeutic commitment in dealing with MHPs of PLWHA vary and their levels of knowledge and skill to deal with MHPs influence their willingness to provide mental health care to PLWHA.
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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
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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.
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
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.
Gongora-Ortega, Javier; Segovia-Bernal, Yolanda; Valdivia-Martinez, J de Jesus; Galaviz-DeAnda, J Martin; Prado-Aguilar, Carlos A
2012-07-11
Evidence suggests that continuing medical education improves the clinical competence of general practitioners and the quality of health care services. Thus, we evaluated the relative impact of two educational strategies, critical reading (CR) and problem based learning (PBL), on the clinical competence of general practitioners in a healthcare system characterized by excessive workload and fragmentation into small primary healthcare centers. Clinical competence was evaluated in general practitioners assigned to three groups based on the educational interventions used: 1) critical reading intervention; 2) problem based learning intervention; and 3) no intervention (control group, which continued clinical practice as normal). The effect on the clinical competence of general practitioners was evaluated in three dimensions: the cognitive dimension, via a self-administered questionnaire; the habitual behavioral dimension, via information from patient's medical records; and the affective dimension, through interviews with patients. A paired Student´s t-test was used to evaluate the changes in the mean clinical competence scores before and after the intervention, and a 3 x 2 ANOVA was used to analyze groups, times and their interaction. Nine general practitioners participated in the critical reading workshop, nine in the problem-based learning workshop, and ten were assigned to the control group. The participants exhibited no significant differences in clinical competence measures at baseline, or in socio-demographic or job characteristics (p > 0.05). Significant improvements in all three dimensions (cognitive, 45.67 vs 54.89; habitual behavioral, 53.78 vs 82.33; affective, 4.16 vs 4.76) were only observed in the problem-based learning group after the intervention (p > 0.017). While no differences in post-intervention scores were observed between groups, we conclude that problem-based learning can be effective, particularly in a small-group context. Indeed
Mashood, K. K.; Singh, Vijay A.
2013-09-01
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 highly competitive problem-solving examinations was studied using a massive database. The sample sizes ranged from hundreds to a few hundred thousand. Encouraged by the presence of significant correlations, we interviewed 20 students to explore the pedagogic potential of physics in imparting transferable problem-solving skills. We report strategies and practices relevant to physics employed by these students which foster transfer.
Hisatomi, N; Ito, K; Nagashima, Y; Fujiwara, K; Yasuda, K; Ashizawa, T; Sato, M; Higuchi, S
1998-12-01
Nurses have the most contact with patients in the clinical settings, and they play an important role in the guidance and education of patients. Nurses' basic knowledge of alcohol-related problems greatly influences early discovery of and early intervention against alcohol-related problems in general units (GU). In a study undertaken mainly to understand the status of nurses' knowledge in GU, a survey was performed to compare the knowledge and attitude of nurses working in GU and those with working in units specializing in the treatment of alcoholism (AU). For reference, we used the results of separate surveys performed previously on the general population. The results showed that, compared with nurses in AU, nurses in GU (1) were more tolerant of drinking, but (2) were more stigmatic concerning alcoholism, and (3) had little knowledge concerning alcohol-related problems. Nurses in GU tended to have less knowledge about alcohol-related problems than the general population. Moreover, the knowledge of nurses in AU could not be considered sufficient. This study suggested the need for basic education concerning alcohol-related problems and their treatment aimed at nurses.
DEFF Research Database (Denmark)
Sølver, Lisbeth; Østergaard, Birte; Rydahl Hansen, Susan
2012-01-01
SOELVER L., OESTERGAARD B., RYDAHL-HANSEN S. & WAGNER L. (2012) European Journal of Cancer Care21, 667-676 Advanced cancer patients' self-assessed physical and emotional problems on admission and discharge from hospital general wards - a questionnaire study Most cancer patients receiving life...
Cherpitel, Cheryl J; Ye, Yu
2008-10-01
Substance use problems are overrepresented in probability samples of patients in primary care settings including the emergency room (ER) compared to the general population. While large proportions of those with alcohol or drug use disorders are most likely to obtain services for these problems outside the mental health or substance abuse treatment system, accounting, in part, for this overrepresentation, little is known about the association of alcohol misuse or drug use with health services utilization in the general population. The prevalence and predictive value of alcohol misuse and drug use on ER and primary care use was analyzed on 6919 respondents from the 2005 National Alcohol Survey (NAS). Among those reporting an ER visit during the last year, 24% were positive for risky drinking (14+ drinks weekly for men and 7+ for females and/or 5+/4+ in a day in the last 12 months), 8% for problem drinking, 3% for alcohol dependence, and 7% for illicit drug use greater than monthly. Figures for primary care users were, respectively: 24%, 5%, 3%, and 3%. ER users were more likely to be positive for problem drinking and greater than monthly illicit drug use compared to non-ER users, while no significant differences were found in substance use for users and non-users of primary care. In logistic regression controlling for gender, age, and health insurance, problem drinkers were twice as likely as non-problem drinkers (Odds ratio, OR=1.99) (pproblems and for initiating a brief intervention.
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
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
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…
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
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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.
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.
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
On The Fekete-Szegö Problem for Generalized Class Mα,γ(β Defined By Differential Operator
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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.
DEFF Research Database (Denmark)
Romelsjö, A; Hasin, D; Hilton, M
1992-01-01
-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...
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
Comptroller General of the U.S., Washington, DC.
Amounts billed for teaching physician services and paid by Medicare carriers were reviewed by the General Accounting Office (GAO) to determine whether such payments had been made only where the physicians had satisfied the requirements of the Social Security Act. Attention was focused on the requirement that teaching physicians must provide a…
Nammouz, Minory Suhil
2005-07-01
The development of problem solving skills and strategies is generally of importance in science education and specifically in chemistry, and is usually assessed by traditional methods such as laboratories, homework, and examinations. However, for instructors, developing a deep understanding of how students solve the problems is difficult and very time consuming. One potential way to address this problem is an internet-based software package known as IMMEX (Interactive Multimedia Exercises). Originally developed at the UCLA Medical School, it has now been expanded to K-12 and college classrooms. IMMEX Problems are case-based and cover a wide range of subject areas. Using this software the students are able to navigate throughout the problem space by choosing the necessary items from a range given to them. The student is provided with immediate feedback; if the student chooses an incorrect answer, most problems will allow for a review of the problem space and submit a second. The IMMEX system tracks the strategies used through a search path map for each problem the student answers; then these data are collected and analyzed using artificial neural networks for pattern recognition. In the present study, students were allowed to stabilize on a problem solving strategy by working five problems before conclusions were drawn regarding their acquired strategies. The major difference now being that any changes in strategy that occurred during and after the intervention of group-work would be by a student that had previously settled on a preferred strategy. The effects of group composition on students' problem solving strategies were also studied. The results presented in this study support the use of collaborative learning as a method that improves students' problem solving strategies. It was found that a collaborative learning environment would not only improve students' problem solving strategies in the groups, but would also carry over their individual subsequent
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Gongora-Ortega Javier
2012-07-01
Full Text Available Abstract Background Evidence suggests that continuing medical education improves the clinical competence of general practitioners and the quality of health care services. Thus, we evaluated the relative impact of two educational strategies, critical reading (CR and problem based learning (PBL, on the clinical competence of general practitioners in a healthcare system characterized by excessive workload and fragmentation into small primary healthcare centers. Methods Clinical competence was evaluated in general practitioners assigned to three groups based on the educational interventions used: 1 critical reading intervention; 2 problem based learning intervention; and 3 no intervention (control group, which continued clinical practice as normal. The effect on the clinical competence of general practitioners was evaluated in three dimensions: the cognitive dimension, via a self-administered questionnaire; the habitual behavioral dimension, via information from patient’s medical records; and the affective dimension, through interviews with patients. A paired Student´s t-test was used to evaluate the changes in the mean clinical competence scores before and after the intervention, and a 3 x 2 ANOVA was used to analyze groups, times and their interaction. Results Nine general practitioners participated in the critical reading workshop, nine in the problem-based learning workshop, and ten were assigned to the control group. The participants exhibited no significant differences in clinical competence measures at baseline, or in socio-demographic or job characteristics (p > 0.05. Significant improvements in all three dimensions (cognitive, 45.67 vs 54.89; habitual behavioral, 53.78 vs 82.33; affective, 4.16 vs 4.76 were only observed in the problem-based learning group after the intervention (p > 0.017. Conclusions While no differences in post-intervention scores were observed between groups, we conclude that problem-based learning can be
Abe, Sumiyoshi
2009-01-01
Quite unexpectedly, kinetic theory is found to specify the correct definition of average value to be employed in nonextensive statistical mechanics. It is shown that the normal average is consistent with the generalized Stosszahlansatz (i.e., molecular chaos hypothesis) and the associated H-theorem, whereas the q-average widely used in the relevant literature is not. In the course of the analysis, the distributions with finite cut-off factors are rigorously treated. Accordingly, the formulati...
Mols, Floortje; Denollet, Johan
2010-01-23
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. 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. 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). 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.
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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.
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
International Nuclear Information System (INIS)
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)
A note on the solution of general Falkner-Skan problem by two novel semi-analytical techniques
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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.
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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
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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.
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
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
Goldberg, Robert K.; Carney, Kelly S.; Dubois, Paul; Hoffarth, Canio; Khaled, Bilal; Shyamsunder, Loukham; Rajan, Subramaniam; Blankenhorn, Gunther
2017-01-01
The need for accurate material models to simulate the deformation, damage and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased use in the aerospace and automotive communities. The aerospace community has identified several key capabilities which are currently lacking in the available material models in commercial transient dynamic finite element codes. To attempt to improve the predictive capability of composite impact simulations, a next generation material model is being developed for incorporation within 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 used to allow for the uncoupling of the deformation and damage analyses. For the failure model, a tabulated approach is utilized in which a stress or strain based invariant is defined as a function of the location of the current stress state in stress space to define the initiation of failure. Failure surfaces can be defined with any arbitrary shape, unlike traditional failure models where the mathematical functions used to define the failure surface impose a specific shape on the failure surface. In the current paper, the complete development of the failure model is described and the generation of a tabulated failure surface for a representative composite material is discussed.
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.
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.
Harris, W F
1991-04-01
In general thickness varies along the cut edge of a lens. There is some interest in being able to predict the locations of the thickest and thinnest points on the edge. One purpose of this paper was to formulate the general problem mathematically of finding the locations of thickness extrema on the edge of an arbitrary lens cut into an arbitrary shape. A second purpose was to illustrate how the problem can be solved. In particular, the problem is solved completely and explicitly for what is probably the simplest case, the straight cut edge. A component-free matrix expression for the position of the extremum is derived by employing Lagrange multipliers and the concept of the generalized inverse of a matrix. The equation applies to spheres, cylinders and sphero-cylinders and allows for the presence of prism as well. Along some edges the thickness is constant. Along other edges the thickness varies linearly; there are no extrema except for the practical extrema at the two ends of the edge: thickest at the one and thinnest at the other. The mathematical conditions for these two cases are presented. Equivalent to the matrix equation for the position vector of the thickness extremum is a pair of scalar equations expressed in terms of components of the matrices. The pair is useful when locating extrema using manual calculations. On the other hand, the component-free matrix equation is useful in other circumstances such as for mathematical manipulations and when using computer software that handles matrices. The former is used in a number of numerical examples; the latter was used to check the answers by computer. The mathematical techniques described here are likely to find application in other areas of ophthalmic and visual optics.
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 pvalue 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.
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.
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
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
Thomas, Shane
2014-06-01
Problem gambling is an increasingly common problem in Australia. General practitioners (GPs) have an important role in ensuring that problem gambling is detected and treated. We review the clinical issues associated with the detection and treatment of problem gambling. At any one time 1% of the adult Australian population satisfy the clinical criteria for problem gambling; a further 4% are at a significant risk. Problem gambling frequently presents with other serious mental health conditions. There are several guidelines from the National Health and Medical Research Council and Australian Medical Association that recommend GP involvement in screening for problem gambling. Simple one-item tools are available for that purpose. GP screening and referral for problem gambling addresses the currently very low rates of treatment. Effective and durable psychological treatments are available for the treatment of problem gambling including cognitive behaviour therapy and motivational interviewing.
General problem of the airplane
Richard, Maurice; Richard, Paul
1922-01-01
A series of equations relating to airplanes are given and examples listed. Some of the equations listed include: the speed, altitude and carrying capacity of various airplanes; weight of an airplane; weight of various parts of an airplane; the polars of the wings; speeds of airplanes; radius of action.
The generalized sports competition problem
Kern, Walter; Paulusma, Daniël
2002-01-01
Consider a sports competition among various teams playing against each other in pairs (matches) according to a previously determined schedule. At some stage of the competition one may ask whether a particular team still has a (theoretical) chance to win the competition. The computational complexity
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
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.
Linden, M; Gothe, H; Ormel, J
2003-12-01
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 physician and specialist they like are a question of high interest. This study compares the Netherlands and Germany, two countries with very similar political, social, and health system structures, but different types of access to the health care system. While Germany offers unconstrained access to specialist ambulatory care, the Netherlands restricts health care utilization by giving primary care a 'gate keeper' function not allowing patients direct access to specialist care. Data from the WHO international collaborative study on psychological problems in general health care (Ustün and Sartorius 1995) were analysed with respect to pathways to care, treatment, and health status. In an initial cross-sectional assessment, in 3-month and 12-month follow-ups, contacts to physicians or hospital admission have also been monitored. There were only marginal differences between the Dutch and the German sample in the sociodemographic characteristics as well as in the diagnostic status with respect to mental disorders. In the Netherlands, 95.5%, and in Germany, 68.8% of the patients presented their 'reason for visit' for the first time to any physician at this index contact with a general practitioner. During the following 3 months, 24% of the Dutch patients, but 60.2% of the German patients, additionally contacted other physicians ( P Germany vs. 25.4 0/00 in the Netherlands ( P system reduce the number of contacts to other physicians and the intensity of treatment, while at the same time the rate of hospital admissions is increased.
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.
Butalid, Ligaya; Bensing, Jozien M; Verhaak, Peter F M
2014-03-01
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. From a database of 5184 consultations videotaped between 1977 and 2008, 512 consultations assessed by GPs as 'completely psychosocial' were coded with RIAS (Roter Interaction Analysis System). The 121 consultations prior to and 391 consultations after implementation of guidelines were analyzed whether communication styles have changed over time. We found that GPs were more likely to consider consultations to be mainly (17%) or completely (12%) psychosocial after the implementation of guidelines. They gave more biomedical and psychosocial information and advice in the second period compared to the first period. We also found that empathy decreased over time (frequency of empathic statements by GPs changed from 2.9-3.2 to 1.4-1.6 between periods). Communication in psychosocial consultations has changed; GPs have become more focused on task-oriented communication (asking questions, giving information and advice) and less on showing empathy. GPs face the challenge of integrating an evidence-based approach of applying guidelines that promote active symptom exploration with understanding patients' personal contexts and giving room to their emotions. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
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.
Hansen, H; Pohontsch, N J; Bole, L; Schäfer, I; Scherer, M
2017-05-25
Patients from rural and urban regions should have equitable access to health care. In Germany, the physician-patient-ratio and the supply of medical services vary greatly between urban and rural areas. The aim of our study was to explore the regional variations of the perceived health care problems in ambulatory care from the perspective of affected professionals and laypersons i.e. general practitioners and their patients. We conducted 27 focus groups with general practitioners (n = 65) and patients (n = 145) from urban areas, environs and rural areas in northern Germany. Discussions were facilitated by two researchers using a semi-structured guideline. The transcripts were content analyzed using deductive and inductive categories. General practitioners and patients reported problems due to demographic change and patient behaviour, through structural inequalities and the ambulatory reimbursement system as well as with specialist care and inpatient care. A high physician density, associated with high competition between general practitioners, a high fluctuation of patients and a low status of general practitioners were the main problems reported in urban areas. In contrast, participants from rural areas reported an insufficient physician density, a lack of young recruits in primary care and a resulting increased workload as problematic. All regions are concerned with subjectively inadequate general practitioners' budgets, insufficiently compensated consultations and problems in the cooperation with specialists and inpatient care institutions. Most problems were mentioned by GPs and patients alike, but some (e.g. high competition rates in urban regions and problems with inpatient care) were only mentioned by GPs. While many problems arise in urban regions as well as in rural regions, our results support the notion that there is an urgent need for action in rural areas. Possible measures include the support of telemedicine, delegation of medical services and
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
[Population problem, comprehension problem].
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
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
International Nuclear Information System (INIS)
Szatmary, Z.
1983-01-01
General experiences in nuclear power are summarized using statistical data revealing the significance of nuclear power in comparison with traditional power sources. Some causes of problems associated with nuclear power are listed, including world recession, high innovation costs, oversupply of nuclear power plants, low availabilities, insufficient arguments for reactor safety to facilitate public acceptance, unsolved waste disposal problems. To assure the world's long-term energy supply, development of commercial fast breeder reactors are suggested. (V.N.)
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.
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).
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
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
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)
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)
Assessment Problems in Reading.
MacGinitie, Walter H., Ed.
The papers in this volume deal with a range of assessment problems in reading. The first paper, by Karlin, introduces the general problem of using assessment procedures to guide teaching. The next six papers deal with various aspects of this general problem. Otto discusses the distinction between norm-referenced, standardized achievement tests and…
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
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
Zhang, Xiaomin; Zhang, Long; Chu, Zhongxiang; Peng, Song
2016-09-01
In this paper, the periodic structure material is modeled as the continuum homogeneous micro-polar media subjecting to thermo-mechanical interaction. Meanwhile, a series of equivalent quantities such as the equivalent stress, couple stress, displacement gradient and torsion tensor were defined by the integral forms of the boundary values of the external surface force, moment, displacement and the angular displacement, and were proved to satisfy the equivalence conditions of virtual work. Based on above works, the displacement boundary value problem was established to deduce the equivalent constitutive equation. Assume the representative volume element is composed of the spatial cross-framework, and applying the boundary value problem of displacement on frame structures, the equivalent elastic coefficients, temperature coefficients of equivalent stress and the temperature gradient coefficients of equivalent couple stress are deduced. In addition, themethod can also be extended to the stress boundary value problem to deduce the equivalent constitutive equation. The calculations indicate that the equivalent result can be obtained from the two kinds of boundary value problems.
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
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.
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
Epstein, Marina; Hill, Karl G.; Bailey, Jennifer A.; Hawkins, J. David
2013-01-01
Previous research has shown that the development of alcohol and tobacco dependence is linked and that both are influenced by environmental and intrapersonal factors, many of which likely interact over the life course. The present study examines the effects of general and alcohol- and tobacco-specific environmental influences in the family of…
Donker, G.A.; Velden, P.G. van der; Kerssens, J.J.; Yzermans, C.J.
2008-01-01
Objective: To assess the characteristics and implications for care of infrequent attendance in general practice in the aftermath of disaster. Methods: A study of the content of electronic medical records (EMRs) in pre- and post-disaster periods linked to an enquiry using self-reported questionnaires
Donker, G.; van der Velden, P.G.; Kerssens, J.; Yzermans, C.J.
2008-01-01
Objective. To assess the characteristics and implications for care of infrequent attendance in general practice in the aftermath of disaster. Methods. A study of the content of electronic medical records (EMRs) in pre- and post-disaster periods linked to an enquiry using self-reported questionnaires
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
Comptroller General of the U.S., Washington, DC.
This report by the Comptroller General of the United States is a review of the Antilles Consolidated School System (ACSS) in Puerto Rico. ACSS, operated by the Department of the Navy, provides free education to children of certain federal employees. The paper reviews the condition of ACSS facilities and efforts to improve it as well as overall…
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...
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
Kawashima, Motoko; Uchino, Miki; Kawazoe, Takashi; Kamiyashiki, Masaaki; Sano, Kokoro; Tsubota, Kazuo
2013-09-27
A Web-based self-check system including a brief questionnaire would seem to be a suitable tool for rapid disease screening. The purpose of this preliminary study was to test a Web-based self-screening questionnaire for drawing attention to dry eye disease among general Internet users and identifying those with a higher risk of developing the condition. A survey website was launched and used to recruit participants from general Internet users. In the first phase, volunteers were asked to complete a Web-based self-screening questionnaire containing 12 questions on dry eye symptoms. The second phase focused on the respondents who reported five or more dry eye symptoms and expressed their intention to seek medical attention. These participants performed the Schirmer test, for evaluating tear production, and completed a paper-based lifestyle questionnaire to provide relevant background data. Of the 1689 visitors to the website, 980 (58.0%) volunteers completed the Web-based self-screening questionnaire. Among these, 355 (36.2%) respondents reported five or more dry eye symptoms. Then, 99 (27.9%) of the symptomatic participants performed the Schirmer test and completed the paper-based lifestyle questionnaire. Out of these, 32 (32.2%) had abnormal tear production (≤5 mm). The proposed Web-based self-screening questionnaire seems to be a promising tool for raising awareness of dry eye disease among general Internet users and identifying those with a higher risk of developing the condition, although further research is needed to validate its effectiveness.
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.
Mavundla, T R; Poggenpoel, M; Gmeiner, A
2001-03-01
The impressive growth in the extent and range of psychiatric services provided by general hospitals in South Africa creates stress among nurses employed in these settings who are not psychiatric trained. This manifests itself in negative attitudes displayed towards mentally ill people. The aim of this paper is to discuss the process followed in the development of the model of facilitative communication. A theory generative design was used. The research methods were dealt with in four steps of theory generation as set out below. Step 1 entailed concept analysis. This step was dealt with in two phases, namely concept identification and concept definition. During concept identification, a qualitative research strategy that is explorative, descriptive and contextual was used. This was achieved through field research conducted in an urban general hospital. A sample of twelve professional nurses was selected from a population of 800 professional nurses employed in a general hospital using the purposive sampling technique. This sample size was determined by saturation of data in themes. Both semi-structured individual phenomenological interviews and observations were used as methods of data collection. Giorgi's method of descriptive data analysis (1985) was used. Four themes emerged from the results of the study. The main concepts of the model were identified and classified using a survey list of Dickoff et al. (1968). Step 2 dealt with the creation of interrelationship statements between concepts identified in Step 1, while Step 3 dealt with the description of the model using strategies proposed by Chinn and Kramer (1991). In Step 4, the description of guidelines for operationalizing in practice was ensured. To ensure valid results, a model for trustworthiness proposed by Guba (Lincoln & Guba, 1985) was used. The following criteria for trustworthiness were applied in all the steps of theory generation: truth value, applicability, consistency and neutrality.
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.)
... Infants and Children Chest Pain, Acute Chest Pain, Chronic Cold and Flu Cough Diarrhea Ear Problems Elimination Problems Elimination Problems in Infants and Children Eye Problems Facial Swelling Feeding Problems in Infants ...
... Infants and Children Chest Pain, Acute Chest Pain, Chronic Cold and Flu Cough Diarrhea Ear Problems Elimination Problems Elimination Problems in Infants and Children Eye Problems Facial Swelling Feeding Problems in Infants ...
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.
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....
Directory of Open Access Journals (Sweden)
Lourdes Figueiras
2010-01-01
Full Text Available Describimos el proceso seguido por estudiantes de 11 y 12 años para descubrir patrones de conteo en un problema básico de combinatoria. Hacemos énfasis en la transición de las estrategias manipulativas para el conteo directo a la generalización. En esta transición hubo estudiantes que utilizaron, de forma espontánea, diagramas de árbol; y otros estudiantes que recurrieron a estrategias comunes en pensamiento numérico. Resaltamos el interés de resolver problemas de combinatoria sin haber aprendido fórmulas previas para que los estudiantes den significado a la regla del producto y relacionamos los resultados obtenidos con aspectos didácticos de la multiplicación en educación primaria. Reasoning and Strategies in the Transition to Generalization in a Combinatorial Problem We describe the procedure used by 11-12 years old students to discover counting patterns in basic combinatory problems. We emphasize the transition from manipulative strategies for direct counting to generalization. In this transition, there were students who spontaneously used tree diagrams of mathematical ideas and some students used numerical thinking strategies. We highlight the interest of solving combinatory problems in order to let the students make sense of the multiplication rule. We relate the results to the teaching of multiplication in primary school.
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.
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.
Directory of Open Access Journals (Sweden)
陳嘉皇 Chia-Huang Chen
2013-03-01
Full Text Available 本研究旨在探索學生對圖形規律問題一般化歷程產出的基模，以掌握學生一般化認知結構，理解其一般化運作情形；並探討學生一般化歷程基模的轉換，建構一般化解題模式，以提升代數思考教學的成效。研究樣本為小學3 名六年級學生，參與研究者設計之三十二項圖形規律問題，並從學生對作業的操作與訪談蒐集資料，資料分析與說明則採質性方法呈現。綜合研究發現，獲得以下三階段結果：學生在發想階段利用「整體圖形關係」和「部分結構要素」概念基模計畫解題，在連結階段則運用「圖形特徵與圖次比對」與「物件計數與圖次比對」概念基模進行圖形與圖次關係的連結，在歸納階段採用「單位組合」與「圖形結構」概念基模，協助其進行解題。在一般化歷程上，也利用「加法」、「乘法」與「實用」等運算基模協助整合規則或算式。學生因圖形結構的性質與一般化解題經驗與知識，讓其在一般化歷程上產生基模與解題策略的改變與轉換，使其朝向更精細代數思考心智模式的運用與圖形整體結構關係之整合。以一般化基模運作與發展作為基礎，可建構出「利用圖形結構」與「利用數字序列」兩種一般化解題模式。研究者根據發現結果提出學生解題模式與建議，提供未來代數思考教學與研究參考。 The purpose of this study is to enhance our understanding of the generalization process by examining the generalization schemas of figural pattern problems and capturing the cognitive structure of generalization, and by examining the ways in which to improve the generalization schema transformation to construct models for solving generalization problems and promote the effects of algebraic thinking. Three Grade six students in a teaching activity setting completed 32 tasks related to figural
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
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.
DEFF Research Database (Denmark)
Almegaard, Henrik
2014-01-01
The majority of literature on engineering design methods is focused on the processes of fulfilling the design goals as efficiently as possible. This paper will focus on - and discuss - the processes of determining the design goals: the specifications. The purpose is to draw attention to the inher...... to the inherent problems, dilemmas and possibilities in these processes bearing in mind that that the most important decisions in a design project are taken in the beginning of the project....
Directory of Open Access Journals (Sweden)
Vina A. Sagita
2018-04-01
Full Text Available Objectives: This study aimed to evaluate the role of a clinical pharmacist intervention in decreasing subsequent clinical and drug-related problems (DRPs among coronary heart disease (CHD inpatients with at least one previous DRP. Methods: This pre-experimental study with a pre-post design was carried out from January to April 2017 among inpatients with at least one previous DRP at a general hospital in Tangerang District, Banten, Indonesia. Clinical and DRPs were documented prospectively by a clinical pharmacist, with DRPs classified using Version 6.2 of the DRP classification scheme of the Pharmaceutical Care Network Europe Foundation. The intervention consisted of a discussion of identified DRPs with physicians, patients, pharmaceutical logistics clerks, nurses and nutritionists. Following this, any subsequent clinical and DRPs were re-identified and further interventions were conducted as necessary. Results: A total of 75 inpatients were included in the study. Pre-intervention, there were 443 DRPs and 202 clinical problems. The most frequent DRPs were adverse drug reactions (52.6%, followed by drug effects (41.8%. Most DRPs were of moderate severity and would have resulted in moderate consequences had the pharmacist not intervened. The interventions resulted in a significant reduction in the number of DRPs, type of DRPs and number of clinical problems (P <0.05 each. Patients with complications were 26.047 times more likely to have no reduction or an increased number of clinical problems compared to patients without complications (P <0.05. Conclusion: Clinical pharmacist interventions were found to reduce subsequent DRPs and clinical problems among CHD patients with at least one previous DRP.
... 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 ...
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
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…
The global existence problem in general relativity
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.
The Twin Prime Problem and Generalizations
Indian Academy of Sciences (India)
IAS Admin
M Ram Murty, a Canadian mathematician, is currently Queen's. Research Chair in. Mathematics and. Philosophy at the Queen's. University in Canada. He is also an adjunct professor at several institutions in India (TIFR in Mumbai, IMSc in. Chennai and HRI in. Allahabad.) He also teaches Indian philosophy at Queen's ...
The Twin Prime Problem and Generalizations
Indian Academy of Sciences (India)
IAS Admin
ture and is best derived using the theory of Ramanujan–. Fourier series expansion of the von Mangoldt function as in a recent paper of Gadiyar and Padma [8] (see also. [11] for a nice exposition). However, it is possible to proceed as follows. By the unique factorization theorem of the natural numbers, we can write log n = ∑.
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
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
The Generalized A* Architecture
Felzenszwalb, P. F.; McAllester, D.
2011-01-01
We consider the problem of computing a lightest derivation of a global structure using a set of weighted rules. A large variety of inference problems in AI can be formulated in this framework. We generalize A* search and heuristics derived from abstractions to a broad class of lightest derivation problems. We also describe a new algorithm that searches for lightest derivations using a hierarchy of abstractions. Our generalization of A* gives a new algorithm for searching AND/OR graphs in a bo...
... 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 ...
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.
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.
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
Obstacle problems in mathematical physics
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.
Problems in equilibrium theory
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.
... the mother, baby, or both. Possible complications include Preterm (premature) labor, when labor starts before 37 completed weeks of pregnancy Problems with the umbilical cord Problems with the position of the baby, such as breech, in which ...
... 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 ...
... your legs or feet Movement disorders such as Parkinson's disease Diseases such as arthritis or multiple sclerosis Vision or balance problems Treatment of walking problems depends on the cause. Physical therapy, surgery, or mobility aids may help.
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...
Generalized connectivity of graphs
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.
DEFF Research Database (Denmark)
Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter Verner
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....
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.
Inverse feasibility problems of the inverse maximum flow problems
Indian Academy of Sciences (India)
A linear time method to decide if any inverse maximum ﬂow (denoted General Inverse Maximum Flow problems (IMFG)) problem has solution is deduced. If IMFG does not have solution, methods to transform IMFG into a feasible problem are presented. The methods consist of modifying as little as possible the restrictions to ...
... can also cause foot problems. The Most Common Types of Foot Problems In older adults, the foot complaints encountered ... people include: Arch pain . From fallen arches (flat feet), or abnormally high arches. Tarsal tunnel syndrome . A type of pinched nerve disorder. Achilles tendonitis . Inflammation of ...
... during your menstrual cycle Premenstrual syndrome (PMS) Problem periods Getting enough sleep Looking and feeling your best Fighting germs Your sexuality What are STDs and STIs? Seeing the doctor Quizzes Links to more information on girls' bodies girlshealth glossary girlshealth.gov home http://www.girlshealth.gov/ Home ... Problem periods Itâs common to have ...
PTSD and Problems with Alcohol Use
... Enter ZIP code here PTSD and Problems with Alcohol Use Public This section is for Veterans, General Public, Family, & Friends PTSD and Problems with Alcohol Use PTSD and alcohol use problems are often ...
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...
Generalized convexity, generalized monotonicity recent results
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...
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...
Indian Academy of Sciences (India)
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 General Editorial. Academy Policy on Plagiarism · More Details Fulltext PDF. Volume 22 Issue 1 January 2017 pp 1-3 General Editorial.
Partington, Gordon Geoffrey
1980-01-01
Discusses controversies concerning the use of generalizations in history. Generalizations lead to national stereotypes and confusion over definitions. Concludes, however, that historical understanding requires criteria to determine what in general may be of importance to the human condition. Classificatory or labeling generalizations are…
... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.
... 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 ...
... Tongue pain may also occur with: Diabetic neuropathy Leukoplakia Mouth ulcers Oral cancer After menopause, some women have ... problem. Medicine may be prescribed for mouth ulcers, leukoplakia, oral cancer, and other mouth sores. Anti-inflammatory medicines ...
... High Blood Pressure Nutrition Join our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & ... specialize in the care of people with kidney (renal) diseases are called nephrologists . What are Kidney Diseases? ...
... Start OverDiagnosisThese thickened areas are likely to be CORNS. If they appear to have small granules in ... these problems. Self CareUse an over-the-counter corn or wart remover. Remove the dead skin after ...
DEFF Research Database (Denmark)
Skovhus, Randi Boelskifte; Thomsen, Rie
2017-01-01
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....
Generalized Riemann derivative
Directory of Open Access Journals (Sweden)
Sorin Radulescu
2013-03-01
Full Text Available Initiated by Marshall Ash in 1966, the study of generalized Riemann derivative draw significant attention of the mathematical community and numerous studies where carried out since then. One of the major areas that benefits from these developments is the numerical analysis, as the use of generalized Riemann derivatives leads to solving a wider class of problems that are not solvable with the classical tools. This article studies the generalized Riemann derivative and its properties and establishes relationships between Riemann generalized derivative and the classical one. The existence of classical derivative implies the existence of the Riemann generalized derivative, and we study conditions necessary for the generalized Riemann derivative to imply the existence of the classical derivative. Furthermore, we provide conditions on the generalized Riemann derivative that are sufficient for the existence of the classical derivative.
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 ...
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....
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 ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 7. The Class Number Problem - An Introduction to Algebraic Number Theory. Rajat Tandon. General ... Author Affiliations. Rajat Tandon1. Department of Mathematics, University of Hyderabad, Central University P.O., Hyderabad 500 046, India ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 6. The Class Number Problem - Binary Quadratic Forms. Rajat Tandon. General Article Volume 3 Issue ... Author Affiliations. Rajat Tandon1. Department of Mathematics, University of Hyderabad, Central University P.O. Hyderabad 500 046. India ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 7. The Class Number Problem - An Introduction to Algebraic Number Theory. Rajat Tandon. General Article Volume 3 Issue 7 July 1998 pp 28-37. Fulltext. Click here to view fulltext PDF. Permanent link:
... generally safe because of modern equipment, medicines, and safety standards. Most people recover completely and do not have any complications. Alternative Names Surgery - general anesthesia Patient Instructions Anesthesia - what to ask your doctor - adult ...
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-...
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
Heuristics for Multidimensional Packing Problems
DEFF Research Database (Denmark)
Egeblad, Jens
costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra...... methods. Two important problem variants are the knapsack packing problem and the strip-packing problem. In the knapsack packing problem, each item is given a profit value, and the problem asks for the subset with maximal profit that can be placed within one container. The strip-packing problem asks...... for a minimum height container required for the items. The main contributions of the thesis are three new heuristics for strip-packing and knapsack packing problems where items are both rectangular and irregular. In the two first papers we describe a heuristic for the multidimensional strip-packing problem...
... If you have BPH, you may need to wake up often to urinate when you sleep. If you can’t urinate at all, you should get medical help right away. Your doctor will know if you have a prostate problem based on ...
Mendoza Mendoza, A; Solano Reina, E
1990-04-01
In this worn we introduce the alterations of the occlusion in the horizontal level or transversal problems, in which lateral crossed bites appear, either with or without a deviation of the medium line, underlying its differential diagnostic and guide lines treatment through several different clinic cases.
Cohen, David K.
1998-01-01
Maintains that Dewey tried to solve social problems related to the growth of industrialism, increasing economic inequality, and political inequality. Argues that Dewey aspired to create a counterculture to correct the human and social devastation of industrial capitalism through a curriculum and instruction that rooted academic learning in…
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.
Generalizations of orthogonal polynomials
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.
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....
Problems over Information Systems
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.
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
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...
Algebraic properties of generalized inverses
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...
Gondoin, C; Lévy, F; Tirmarche, D
2012-01-01
Memory impairments are common in elderly. General practitioners are in first line to detect and manage these troubles, for which many countries published recommendations. For Alzheimer disease there are currently four treatments, none of which is healing. Some countries limited the first prescription of those medicines to specialists whereas in Luxembourg, every practitioner is allowed to prescribe them, but has to ask health insurance first. Consequently, it is important that general practitioners know what to do. The aim of our paper is to study the management done by the general practitioners in Luxembourg, the way they feel about it and the way they see the specific medicines for Alzheimer disease. Therefore, we have sent a questionnaire to every general practitioner in Luxembourg. We found that 87% of the practitioners realize at least one cognitive impairment test. More than half of them check for depression and 22.6% also add an autonomy assessment scale, even though all these tests are done by the dependence insurance. The involvement of general practitioners in the diagnosis of dementia is important as more than half of them have a statistically adequate number of demented patients. About two third of the practitioners do systematically start a specific medicine for Alzheimer disease. The management of cognitive impairment is difficult for general practitioners of Luxembourg, particularly the disclosure of diagnosis and management of behavioural and psychological symptoms.
Adair, R H; Bauchner, H
1993-04-01
Sleep, like eating and toileting, is an individual physical requirement that changes with time as the child matures. Although much about a child's sleep is biologically determined, extrinsic factors, usually through the parents, also mold the child's sleep behavior. Normal sleep for a child is restful to the child and not excessively disruptive to others. Sleep problems interfere with the quality of the child's sleep and frustrate or frighten caretakers. Several sleep problems have their origins in normal sleep behavior from an earlier age. Some, the parasomnias, are caused by self-limited biologic diatheses. Many sleep problems have psychosocial triggers. Sleep disorders only rarely are a primary medical problem that is adequately treated with medication (e.g., narcolepsy). Good history-taking, often accompanied by diary-keeping, will usually identify the problem--the first step in effective treatment. Treatment of a sleep disorder in the pediatrician's office can start with educating caretakers about normative sleep for the age of the child and providing information regarding the cause and natural course of the problem. Treatment also may involve behavioral or psychological intervention or both, but medication is generally not indicated. When needed for short-term treatment, mild sedatives such as antihistamines are used most often. More serious sleep or behavioral problems should be acknowledged by the primary care pediatrician, followed by referral to an appropriate specialist. Inquiry into a child's sleep habits at each well-child visit, coupled with appropriate anticipatory guidance, could make an important contribution to the child and family by preventing problems with sleep and identifying sleep problems early in their evolution. Pediatricians and parents can work together to help children develop good sleep habits that fulfill the child's evolving sleep requirements within the context of the family's needs and expectations.
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...
... Understanding Problems and Causes Heart Murmurs and Valve Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - Problem: Pulmonary Valve Stenosis Problem: Mitral ...
A Problem on Optimal Transportation
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…
Directory of Open Access Journals (Sweden)
Jiménez Morales Ana Patricia
2009-08-01
Full Text Available Resumen:Durante el primer semestre del 2007, se realizó un estudio para evaluar la opinión de los estudiantes del Repertorio de Problemas Ecológicos, de la Escuela de Estudios Generales de la Universidad de Costa Rica, 155 estudiantes fueron entrevistados después de participar en una gira de estudio como una actividad del curso.El objetivo de la investigación fue indagar la importancia de las giras al campo como apoyo a su formación profesional, así como promotora de un cambio de concepción de mundo en su relación con el ambiente. Además, era de interés evaluar la presencia del curso en el ámbito universitario debido a que es un curso de repertorio dirigido a estudiante de carreras diferentes a las ciencias básicas. Como resultado de la investigación se obtuvo que la mayoría de los entrevistados (70.97% ve la gira importante en su formación profesional, pues les permite una educación integral. Además, esta práctica le permitió al 65.8% de los participantes cambiar su concepción de mundo en relación con el ambiente y a un 19.35% reafirmar sus creencias, permitiéndoles observar personalmente lo que ya conocían en forma teórica. A nivel U niversitario se comprobó que el curso tiene una presencia importante, los estudiantes que participaron como informantes pertenecían a 44 carreras de 12 facultades distintas.Abstract:During the first term of 2007 a study to evaluate the opinion of the students of the Repertoire of Ecological Problems, of the School of General Studies of the University of Costa Rica was carried out, 155 students were interviewed after participating in a study field trip. The objective of the research was to investigate the relevance of this practice in its professional development, as well as promotional of a change of world conception in its relation with the environment. In addition, it was of interest to evaluate the presence of the course in the university scope because it is a course of repertoire
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)
Solving Environmental Problems
DEFF Research Database (Denmark)
Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph
2017-01-01
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...... 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......Recent innovation and strategy research emphasizes the importance of firm’s search for external knowledge to improve innovation performance. We focus on such search strategies within the domain of sustainable innovation in which problems are inherently complex and the relevant knowledge is widely...
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.
Adler, Stephen L.; Wilczek, Frank
1994-10-01
This report is a progress report on the work of two principal investigators in the broad area of particle physics theory, covering their personal work, that of their coworkers, and their proposed work for the future. One author has worked in the past on various topics in field theory and particle physics, among them current algebras, the physics of neutrino induced reactions, quantum electrodynamics (including strong magnetic field processes), the theory of the axial-vector current anomaly, topics in quantum gravity, and nonlinear models for quark confinement. While much of his work has been analytical, all of the projects listed above (except for the work on gravity) had phases which required considerable computer work as well. Over the next several years, he proposes to continue or initiate research on the following problems: (1) acceleration algorithms for the Monte Carlo analysis of lattice field and gauge theories, and more generally, new research in computational neuroscience and pattern recognition; (2) construction of quaternionic generalizations of complex quantum mechanics and field theory, and their application to composite models of quarks and leptons, and to the problem of unifying quantum theories of matter with general relativity. One author has worked on problems in exotic quantum statistics and its applications to condensed matter systems. His work has also continued on the quantum theory of black holes. This has evolved toward understanding properties of quantum field theory and string theory in incomplete regions of flat space.
Existence results for trifunction equilibrium problems and fixed point problems
Mahato, Nihar Kumar; Noor, Muhammad Aslam; Sahu, Nabin Kumar
2017-10-01
In this paper, we establish the existence and uniqueness solutions of trifunction equilibrium problems using the generalized relaxed α -monotonicity in Banach spaces. By using the generalized f-projection operator, a hybrid iteration scheme is presented to find a common element of the solutions of a system of trifunction equilibrium problems and the set of fixed points of an infinite family of quasi-φ -nonexpansive mappings. Moreover, the strong convergence of our new proposed iterative method under generalized relaxed α -monotonicity is considered.
A Note on the Room-Mates Problem and a Related Revenue Allocation Problem
Daniel Granot
1984-01-01
We introduce in this note the consistent organizational structure (COS) problem, which can be viewed as a generalization of the college admission and room-mates problems. Both the room-mates problem and the COS problem may have no stable solution. When side payments are allowed, the COS problem, but not the room-mates problem, always has a nonempty core. We further study some nucleoli of the COS problem with side payments.
African Journals Online (AJOL)
Hydatid disease, a zoonotic disease caused by Echinococcus. spp of helminths. E. granulosus, is the commonest cause of cystic hydatidosis, a disease which continues to be a serious public problem causing morbidity and mortality in China,. Eastern Europe, Turkey, the Far East and South Africa.1,2. Hydatid cysts may ...
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 ...
Reider, Norman
1957-01-01
Moral, religious and legal attitudes in attempts to control sexual behavior have interfered with a clear view of the medical and psychological aspects of homosexuality. This phenomenon is probably much less destructive of social aspects of our society and culture than is generally believed, since it is actually more widespread than is generally acknowledged. Homosexuality probably has hormonal and undoubtedly social and psychological factors, the latter of which are the only ones which can be worked with successfully in our present state of knowledge. A general practitioner's task is to aid those who wish and need help with this problem in finding psychiatric treatment in the same way that persons with any other emotional disturbance are referred. This should be carried out without bias just as with any other emotional disturbance. PMID:13426813
Five Generalizations About Cognitive Development.
Siegler, Robert S.
1983-01-01
Proposes five generalizations on existing knowledge, learning, and their interaction, and discusses evidence for these from recent research on children's learning, memory, conceptual understanding, and problem solving. (Author/AOS)
Glauber model and its generalizations
International Nuclear Information System (INIS)
Bialkowski, G.
The physical aspects of the Glauber model problems are studied: potential model, profile function and Feynman diagrams approaches. Different generalizations of the Glauber model are discussed: particularly higher and lower energy processes and large angles [fr
Mechanics of Generalized Continua
Altenbach, Holm; Erofeev, Vladimir
2011-01-01
This collection on auMechanics of Generalized Continua - from Micromechanical Basics to Engineering Applications" brings together leading scientists in this field from France, Russian Federation, and Germany. The attention in this publication is be focussed on the most recent research items, i.e., - new models, - application of well-known models to new problems, - micro-macro aspects, - computational effort, - possibilities to identify the constitutive equations, and - old problems with incorrect or non-satisfying solutions based on the classical continua assumptions.
González Arias, Henry Giovanni
2011-01-01
Por medio de la recopilación de información y adaptación de métodos planteados por una guía metodológica de manejo pesquero, se formularon los lineamientos para generar un plan de manejo pesquera para la Isla Fuerte, aportando datos biológicos, ecológicos, sociales, y de gestión ambiental que permitan gestionar procesos de mejoramiento ambiental y social. La problemática ambiental de Isla Fuerte principalmente se genera por falta de conciencia y educación, donde el problema ambiental da mayor...
International Nuclear Information System (INIS)
Tubiana, M.
1993-01-01
In conclusion, a general consensus of a number of points which the author endeavours to summarize in this article: -doctors are an excellent channel for passing on information to the public -doctors feel that they do not know enough about the subject and a training on radiobiology and radiation protection is a necessity for them -communication between doctors and the general public is poor in this field -research should be encouraged in numerous areas such as: carcinogenic effect of low doses of radiation, pedagogy and risk perception
Musielak, Z E; Quarles, B
2014-06-01
The three-body problem, which describes three masses interacting through Newtonian gravity without any restrictions imposed on the initial positions and velocities of these masses, has attracted the attention of many scientists for more than 300 years. In this paper, we present a review of the three-body problem in the context of both historical and modern developments. We describe the general and restricted (circular and elliptic) three-body problems, different analytical and numerical methods of finding solutions, methods for performing stability analysis and searching for periodic orbits and resonances. We apply the results to some interesting problems of celestial mechanics. We also provide a brief presentation of the general and restricted relativistic three-body problems, and discuss their astronomical applications.
Lectures on general relativity
Papapetrou, Achille
1974-01-01
This book is an elaboration of lecture notes for the graduate course on General Rela tivity given by the author at Boston University in the spring semester of 1972. It is an introduction to the subject only, as the time available for the course was limited. The author of an introduction to General Relativity is faced from the beginning with the difficult task of choosing which material to include. A general criterion as sisting in this choice is provided by the didactic character of the book: Those chapters have to be included in priority, which will be most useful to the reader in enabling him to understand the methods used in General Relativity, the results obtained so far and possibly the problems still to be solved. This criterion is not sufficient to ensure a unique choice. General Relativity has developed to such a degree, that it is impossible to include in an introductory textbook of a reasonable length even a very condensed treatment of all important problems which have been discussed unt...
1949-01-01
In part I of this study a survey has veen given of what Dutch authors have written since 1870, when capital punishment was abolished, on subjects concerning the general preventive effect of punishment. This historical survey ends where, during the years 1940-1945, under the stress of the occupation
Staff Association
2016-01-01
5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...
Leider, A S; Garbarino, V E
1987-03-01
The case of an elderly female patient with a long-standing history of generalized hypercementosis is described. A thorough review of the literature indicates that this may be one of the most extensive cases of hypercementosis to be reported. Possible etiologic factors--including heredity, systemic disorders, chronic periapical infection, and abnormal occlusal trauma--are discussed.
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 2. Supersymmetry. Akshay Kulkarni P Ramadevi. General Article Volume 8 Issue 2 February 2003 pp 28-41. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/02/0028-0041. Keywords. Symmetry ...
Straumann, Norbert
2013-01-01
This book provides a completely revised and expanded version of the previous classic edition ‘General Relativity and Relativistic Astrophysics’. In Part I the foundations of general relativity are thoroughly developed, while Part II is devoted to tests of general relativity and many of its applications. Binary pulsars – our best laboratories for general relativity – are studied in considerable detail. An introduction to gravitational lensing theory is included as well, so as to make the current literature on the subject accessible to readers. Considerable attention is devoted to the study of compact objects, especially to black holes. This includes a detailed derivation of the Kerr solution, Israel’s proof of his uniqueness theorem, and a derivation of the basic laws of black hole physics. Part II ends with Witten’s proof of the positive energy theorem, which is presented in detail, together with the required tools on spin structures and spinor analysis. In Part III, all of the differential geomet...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 2. Supersymmetry. Akshay Kulkarni P Ramadevi. General Article Volume 8 Issue 2 February 2003 pp 28-41 ... Author Affiliations. Akshay Kulkarni1 P Ramadevi1. Physics Department, Indian Institute of Technology, Mumbai 400 076, India.
Indian Academy of Sciences (India)
IAS Admin
. A q-ary necklace of length n is an equivalence class of q-coloured strings of length n under rota- tion. In this article, we study various generaliza- tions and derive analytical expressions to count the number of these generalized necklaces.
African Journals Online (AJOL)
Department of Surgery, University of Cape Town Health Sciences Faculty, Groote Schuur Hospital, Observatory, Cape Town,. South Africa ... included all district, regional and tertiary hospitals in the nine provinces. Clinics and so-called ..... large contingency of senior general surgeons from countries such as Cuba, who have ...
Implementing general gauge mediation
International Nuclear Information System (INIS)
Carpenter, Linda M.; Dine, Michael; Festuccia, Guido; Mason, John D.
2009-01-01
Recently there has been much progress in building models of gauge mediation, often with predictions different than those of minimal gauge mediation. Meade, Seiberg, and Shih have characterized the most general spectrum which can arise in gauge-mediated models. We discuss some of the challenges of building models of general gauge mediation, especially the problem of messenger parity and issues connected with R symmetry breaking and CP violation. We build a variety of viable, weakly coupled models which exhibit some or all of the possible low energy parameters.
Generalized Probability-Probability Plots
Mushkudiani, N.A.; Einmahl, J.H.J.
2004-01-01
We introduce generalized Probability-Probability (P-P) plots in order to study the one-sample goodness-of-fit problem and the two-sample problem, for real valued data.These plots, that are constructed by indexing with the class of closed intervals, globally preserve the properties of classical P-P
The General Factor of Personality: A General Critique
Revelle, William; Wilt, Joshua
2013-01-01
Recently, it has been proposed that all non-cognitive measures of personality share a general factor of personality. A problem with many of these studies is a lack of clarity in defining a general factor. In this paper we address the multiple ways in which a general factor has been identified and argue that many of these approaches find factors that are not in fact general. Through the use of artificial examples, we show that a general factor is not: The first factor or component of a correla...
Maldeghem, Hendrik
1998-01-01
This book is intended to be an introduction to the fascinating theory ofgeneralized polygons for both the graduate student and the specialized researcher in the field. It gathers together a lot of basic properties (some of which are usually referred to in research papers as belonging to folklore) and very recent and sometimes deep results. I have chosen a fairly strict geometrical approach, which requires some knowledge of basic projective geometry. Yet, it enables one to prove some typically group-theoretical results such as the determination of the automorphism groups of certain Moufang polygons. As such, some basic group-theoretical knowledge is required of the reader. The notion of a generalized polygon is a relatively recent one. But it is one of the most important concepts in incidence geometry. Generalized polygons are the building bricks of Tits buildings. They are the prototypes and precursors of more general geometries such as partial geometries, partial quadrangles, semi-partial ge ometries, near...
Sums of Generalized Harmonic Series
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 9. Sums of Generalized Harmonic Series: For Kids from Five to Fifteen. Zurab Silagadze. General Article Volume 20 Issue 9 September 2015 pp 822-843 ... Keywords. Riemann zeta function; integral representation; Basel problem.
Gurr, Henry
2014-03-01
Princeton Physicist J. J. Hopfield's Mathematical Model of the Mammalian Brain, (Similar To Ising Glass Model of a crystal of magnetic spin particles) says our Brain-Work for Memory, Perception, Language, Thinking, etc, (Even the AHA-EUREKA-Flash Of Insight Type Problem Solving), is achieved by our massively inter-connected CNS Neurons ... working together ... MINIMIZING an analog of physical energy ... thus yielding Optimal Solutions: These ``best'' answers, correspond to highest mental coherence, for most facets organism response, beit mental (eg: perception, memory, ideas, thinking, etc) or physical-muscular-actions (eg speaking, tool using, trail following, etc). Our brain is this way, because living creature, MUST be evolved, so they will find & use the best actions, for survival!!! Our human heritage, is to instantly compute near optimal future plans, (mental & physical-muscular), and be able to accomplish plans reliably & efficiently. If you know of book or articles in these topic areas, please email to HenryG--USCA.edu How to work well, with your own ``self'', called mind-body, will follow!! Conjectures: Who is the ``I'' that appears to make decisions? Am ``I'' the master of my domain? Is there an ``I'' or am ``I'' merely an illusion of reality.
Directory of Open Access Journals (Sweden)
INTAN S. AHMAD
2008-04-01
Full Text Available This work presents the application of a primal-dual interior point method to minimax optimisation problems. The algorithm differs significantly from previous approaches as it involves a novel non-monotone line search procedure, which is based on the use of standard penalty methods as the merit function used for line search. The crucial novel concept is the discretisation of the penalty parameter used over a finite range of orders of magnitude and the provision of a memory list for each such order. An implementation within a logarithmic barrier algorithm for bounds handling is presented with capabilities for large scale application. Case studies presented demonstrate the capabilities of the proposed methodology, which relies on the reformulation of minimax models into standard nonlinear optimisation models. Some previously reported case studies from the open literature have been solved, and with significantly better optimal solutions identified. We believe that the nature of the non-monotone line search scheme allows the search procedure to escape from local minima, hence the encouraging results obtained.
Directory of Open Access Journals (Sweden)
Michael Segal
2004-11-01
Full Text Available Abstract: Ad-hoc networks of sensor nodes are in general semi-permanently deployed. However, the topology of such networks continuously changes over time, due to the power of some sensors wearing out to new sensors being inserted into the network, or even due to designers moving sensors around during a network re-design phase (for example, in response to a change in the requirements of the network. In this paper, we address the problem of covering a given path by a limited number of sensors Ã¢Â€Â” in our case to two, and show its relation to the well-studied matrix multiplication problem.
... Infants and Children Chest Pain, Acute Chest Pain, Chronic Cold and Flu Cough Diarrhea Ear Problems Elimination Problems Elimination Problems in Infants and Children Eye Problems Facial Swelling Feeding Problems in Infants ...
Generalized isothermic lattices
International Nuclear Information System (INIS)
Doliwa, Adam
2007-01-01
We study multi-dimensional quadrilateral lattices satisfying simultaneously two integrable constraints: a quadratic constraint and the projective Moutard constraint. When the lattice is two dimensional and the quadric under consideration is the Moebius sphere one obtains, after the stereographic projection, the discrete isothermic surfaces defined by Bobenko and Pinkall by an algebraic constraint imposed on the (complex) cross-ratio of the circular lattice. We derive the analogous condition for our generalized isothermic lattices using Steiner's projective structure of conics, and we present basic geometric constructions which encode integrability of the lattice. In particular, we introduce the Darboux transformation of the generalized isothermic lattice and we derive the corresponding Bianchi permutability principle. Finally, we study two-dimensional generalized isothermic lattices, in particular geometry of their initial boundary value problem
DEFF Research Database (Denmark)
Skov Jensen, Christian; Lando, David; Heje Pedersen, Lasse
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...... of Ross (2015). Our characterization is simple and intuitive, linking recovery to the relation between the number of time periods and the number of states. When recovery is feasible, our model is easy to implement, allowing a closed-form linearized solution. We implement our model empirically, testing...