WorldWideScience

Sample records for variational problem defined

  1. Homogenization of variational inequalities and equations defined by pseudomonotone operators

    International Nuclear Information System (INIS)

    Sandrakov, G V

    2008-01-01

    Results on the convergence of sequences of solutions of non-linear equations and variational inequalities for obstacle problems are proved. The variational inequalities and equations are defined by a non-linear, pseudomonotone operator of the second order with periodic, rapidly oscillating coefficients and by sequences of functions characterizing the obstacles and the boundary conditions. Two-scale and macroscale (homogenized) limiting problems for such variational inequalities and equations are obtained. Results on the relationship between solutions of these limiting problems are established and sufficient conditions for the uniqueness of solutions are presented. Bibliography: 25 titles

  2. Homogenization of variational inequalities for obstacle problems

    International Nuclear Information System (INIS)

    Sandrakov, G V

    2005-01-01

    Results on the convergence of solutions of variational inequalities for obstacle problems are proved. The variational inequalities are defined by a non-linear monotone operator of the second order with periodic rapidly oscillating coefficients and a sequence of functions characterizing the obstacles. Two-scale and macroscale (homogenized) limiting variational inequalities are obtained. Derivation methods for such inequalities are presented. Connections between the limiting variational inequalities and two-scale and macroscale minimization problems are established in the case of potential operators.

  3. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander

    2013-12-17

    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  4. General inverse problems for regular variation

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  5. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander; Markowich, Peter A.; Perthame, Benoî t

    2013-01-01

    The question of 'cutting the tail' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric

  6. Nonterminals and codings in defining variations of OL-systems

    DEFF Research Database (Denmark)

    Skyum, Sven

    1974-01-01

    The use of nonterminals versus the use of codings in variations of OL-systems is studied. It is shown that the use of nonterminals produces a comparatively low generative capacity in deterministic systems while it produces a comparatively high generative capacity in nondeterministic systems. Fina....... Finally it is proved that the family of context-free languages is contained in the family generated by codings on propagating OL-systems with a finite set of axioms, which was one of the open problems in [10]. All the results in this paper can be found in [71] and [72].......The use of nonterminals versus the use of codings in variations of OL-systems is studied. It is shown that the use of nonterminals produces a comparatively low generative capacity in deterministic systems while it produces a comparatively high generative capacity in nondeterministic systems...

  7. On the use of antithetic variates in particle transport problems

    International Nuclear Information System (INIS)

    Milgram, M.S.

    2001-01-01

    The possible use of antithetic variates as a method of variance reduction in particle transport problems is investigated, by performing some numerical experiments. It is found that if variance reduction is not very carefully defined, it is possible, with antithetic variates, to spuriously detect reduction, or not detect true reduction. Once such subtleties are overcome, it is shown that antithetic variates can reduce variance in multidimensional integration up to a point. The phenomenon of spontaneous correlation is defined and identified as the cause of failure. The surprising result that it sometimes pays to track non-contributing particle histories is demonstrated by means of a zero variance integration analogue. The principles developed in the investigation of multi-variable integration are then employed in a simple calculation of energy deposition using the EGS4 computer code. Promising results are obtained for the total energy deposition problem, but the depth/dose problem remains unsolved. Possible means of overcoming the difficulties are suggested

  8. Undergraduate Performance in Solving Ill-Defined Biochemistry Problems

    Science.gov (United States)

    Sensibaugh, Cheryl A.; Madrid, Nathaniel J.; Choi, Hye-Jeong; Anderson, William L.; Osgood, Marcy P.

    2017-01-01

    With growing interest in promoting skills related to the scientific process, we studied performance in solving ill-defined problems demonstrated by graduating biochemistry majors at a public, minority-serving university. As adoption of techniques for facilitating the attainment of higher-order learning objectives broadens, so too does the need to…

  9. Variational problems for plane curves in centro-affine geometry

    International Nuclear Information System (INIS)

    Musso, Emilio

    2010-01-01

    In this paper closed extremals of variational problems defined by quadratic polynomials in the centro-affine curvature are considered. The closure of the trajectories is discussed and the existence of countably many closed critical curves is proven. The geometrical properties of closed trajectories are analyzed by numerical methods.

  10. A Formal Model and Verification Problems for Software Defined Networks

    Directory of Open Access Journals (Sweden)

    V. A. Zakharov

    2013-01-01

    Full Text Available Software-defined networking (SDN is an approach to building computer networks that separate and abstract data planes and control planes of these systems. In a SDN a centralized controller manages a distributed set of switches. A set of open commands for packet forwarding and flow-table updating was defined in the form of a protocol known as OpenFlow. In this paper we describe an abstract formal model of SDN, introduce a tentative language for specification of SDN forwarding policies, and set up formally model-checking problems for SDN.

  11. Schwartz distributions in the Lagrange variational problem

    International Nuclear Information System (INIS)

    Anton, H.; Bahar, L.Y.

    1978-01-01

    Schwartz distributions are used to eliminate the necessity of imposing a priori conditions on the class of admissible functions in the Lagrange fixed end-point variational problem. This makes it possible to defer the imposition of conditions on the extremals until such conditions become apparent from physical considerations

  12. Variational segmentation problems using prior knowledge in imaging and vision

    DEFF Research Database (Denmark)

    Fundana, Ketut

    This dissertation addresses variational formulation of segmentation problems using prior knowledge. Variational models are among the most successful approaches for solving many Computer Vision and Image Processing problems. The models aim at finding the solution to a given energy functional defined......, prior knowledge is needed to obtain the desired solution. The introduction of shape priors in particular, has proven to be an effective way to segment objects of interests. Firstly, we propose a prior-based variational segmentation model to segment objects of interest in image sequences, that can deal....... Many objects have high variability in shape and orientation. This often leads to unsatisfactory results, when using a segmentation model with single shape template. One way to solve this is by using more sophisticated shape models. We propose to incorporate shape priors from a shape sub...

  13. Error identities for variational problems with obstacles

    Czech Academy of Sciences Publication Activity Database

    Repin, S.; Valdman, Jan

    2018-01-01

    Roč. 98, č. 4 (2018), s. 635-658 ISSN 0044-2267 R&D Projects: GA ČR(CZ) GF16-34894L; GA ČR GA17-04301S; GA MŠk(CZ) 7AMB16AT015 Institutional support: RVO:67985556 Keywords : variational problems with obstacles * coincidence set * convex functionals * error identities Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.332, year: 2016 http://library.utia.cas.cz/separaty/2017/MTR/valdman-0483574.pdf

  14. On the Update Problems for Software Defined Networks

    Directory of Open Access Journals (Sweden)

    V. A. Zakharov

    2014-01-01

    Full Text Available The designing of network update algorithms is urgent for the development of SDN control software. A particular case of Network Update Problem is that of restoring seamlessly a given network configuration after some packet forwarding rules have been disabled (say, at the expiry of their time-outs. We study this problem in the framework of a formal model of SDN, develop correct and safe network recovering algorithms, and show that in general case there is no way to restore network configuration seamlessly without referring to priorities of packet forwarding rules.

  15. On inverse problem of calculus of variations

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Z-L [College of Mathematics and Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China)], E-mail: zaolingt@nuist.edu.cn

    2008-02-15

    Using the semi-inverse method proposed by Ji-Huan He, variational principles are established for some nonlinear equations arising in physics, including the (p, 2p)-mZK equation, Klein-Gordon equation, sine-Gordon equation, Liouville equation, Dodd- Bullough-Mikhailov equation, and Tzitzeica-Dodd-Bullough equation.

  16. On a variational principle for shape optimization and elliptic free boundary problems

    Directory of Open Access Journals (Sweden)

    Raúl B. González De Paz

    2009-02-01

    Full Text Available A variational principle for several free boundary value problems using a relaxation approach is presented. The relaxed Energy functional is concave and it is defined on a convex set, so that the minimizing points are characteristic functions of sets. As a consequence of the first order optimality conditions, it is shown that the corresponding sets are domains bounded by free boundaries, so that the equivalence of the solution of the relaxed problem with the solution of several free boundary value problem is proved. Keywords: Calculus of variations, optimization, free boundary problems.

  17. A Modified Alternating Direction Method for Variational Inequality Problems

    International Nuclear Information System (INIS)

    Han, D.

    2002-01-01

    The alternating direction method is an attractive method for solving large-scale variational inequality problems whenever the subproblems can be solved efficiently. However, the subproblems are still variational inequality problems, which are as structurally difficult to solve as the original one. To overcome this disadvantage, in this paper we propose a new alternating direction method for solving a class of nonlinear monotone variational inequality problems. In each iteration the method just makes an orthogonal projection to a simple set and some function evaluations. We report some preliminary computational results to illustrate the efficiency of the method

  18. Noether's Theorem and its Inverse of Birkhoffian System in Event Space Based on Herglotz Variational Problem

    Science.gov (United States)

    Tian, X.; Zhang, Y.

    2018-03-01

    Herglotz variational principle, in which the functional is defined by a differential equation, generalizes the classical ones defining the functional by an integral. The principle gives a variational principle description of nonconservative systems even when the Lagrangian is independent of time. This paper focuses on studying the Noether's theorem and its inverse of a Birkhoffian system in event space based on the Herglotz variational problem. Firstly, according to the Herglotz variational principle of a Birkhoffian system, the principle of a Birkhoffian system in event space is established. Secondly, its parametric equations and two basic formulae for the variation of Pfaff-Herglotz action of a Birkhoffian system in event space are obtained. Furthermore, the definition and criteria of Noether symmetry of the Birkhoffian system in event space based on the Herglotz variational problem are given. Then, according to the relationship between the Noether symmetry and conserved quantity, the Noether's theorem is derived. Under classical conditions, Noether's theorem of a Birkhoffian system in event space based on the Herglotz variational problem reduces to the classical ones. In addition, Noether's inverse theorem of the Birkhoffian system in event space based on the Herglotz variational problem is also obtained. In the end of the paper, an example is given to illustrate the application of the results.

  19. L∞ Variational Problems with Running Costs and Constraints

    International Nuclear Information System (INIS)

    Aronsson, G.; Barron, E. N.

    2012-01-01

    Various approaches are used to derive the Aronsson–Euler equations for L ∞ calculus of variations problems with constraints. The problems considered involve holonomic, nonholonomic, isoperimetric, and isosupremic constraints on the minimizer. In addition, we derive the Aronsson–Euler equation for the basic L ∞ problem with a running cost and then consider properties of an absolute minimizer. Many open problems are introduced for further study.

  20. Defining the XML schema matching problem for a personal schema based query answering system

    NARCIS (Netherlands)

    Smiljanic, M.; van Keulen, Maurice; Jonker, Willem

    In this report, we analyze the problem of personal schema matching. We define the ingredients of the XML schema matching problem using constraint logic programming. This allows us to thourougly investigate specific matching problems. We do not have the ambition to provide for a formalism that covers

  1. A duality recipe for non-convex variational problems

    Science.gov (United States)

    Bouchitté, Guy; Phan, Minh

    2018-03-01

    The aim of this paper is to present a general convexification recipe that can be useful for studying non-convex variational problems. In particular, this allows us to treat such problems by using a powerful primal-dual scheme. Possible further developments and open issues are given. xml:lang="fr"

  2. Solution of problems in calculus of variations via He's variational iteration method

    International Nuclear Information System (INIS)

    Tatari, Mehdi; Dehghan, Mehdi

    2007-01-01

    In the modeling of a large class of problems in science and engineering, the minimization of a functional is appeared. Finding the solution of these problems needs to solve the corresponding ordinary differential equations which are generally nonlinear. In recent years He's variational iteration method has been attracted a lot of attention of the researchers for solving nonlinear problems. This method finds the solution of the problem without any discretization of the equation. Since this method gives a closed form solution of the problem and avoids the round off errors, it can be considered as an efficient method for solving various kinds of problems. In this research He's variational iteration method will be employed for solving some problems in calculus of variations. Some examples are presented to show the efficiency of the proposed technique

  3. Variational structure of inverse problems in wave propagation and vibration

    Energy Technology Data Exchange (ETDEWEB)

    Berryman, J.G.

    1995-03-01

    Practical algorithms for solving realistic inverse problems may often be viewed as problems in nonlinear programming with the data serving as constraints. Such problems are most easily analyzed when it is possible to segment the solution space into regions that are feasible (satisfying all the known constraints) and infeasible (violating some of the constraints). Then, if the feasible set is convex or at least compact, the solution to the problem will normally lie on the boundary of the feasible set. A nonlinear program may seek the solution by systematically exploring the boundary while satisfying progressively more constraints. Examples of inverse problems in wave propagation (traveltime tomography) and vibration (modal analysis) will be presented to illustrate how the variational structure of these problems may be used to create nonlinear programs using implicit variational constraints.

  4. Strong Convergence Theorems for Variational Inequalities and Split Equality Problem

    Directory of Open Access Journals (Sweden)

    Yu Jing Wu

    2013-01-01

    Full Text Available Let H1, H2, and H3 be real Hilbert spaces, let C⊆H1, Q⊆H2 be two nonempty closed convex sets, and let A:H1→H3, B:H2→H3 be two bounded linear operators. The split equality problem (SEP is to find x∈C, y∈Q such that Ax=By. Let H=H1×H2; consider f:H→H a contraction with coefficient 00, and M:H→H is a β-inverse strongly monotone mapping. Let 0<γ<γ̅/α, S=C×Q and G:H→H3 be defined by restricting to H1 is A and restricting to H2 is -B, that is, G has the matrix form G=[A,-B]. It is proved that the sequence {wn}={(xn,yn}⊆H generated by the iterative method wn+1=PS[αnγf(wn+(I-αnTPS(I-γnG*GPS(wn-λnMwn] converges strongly to w̃ which solves the SEP and the following variational inequality: 〈(T-λfw̃,w-w̃〉≥0 and 〈Mw̃,w-w̃〉≥0 for all w∈S. Moreover, if we take M=G*G:H→H,  γn=0, then M is a β-inverse strongly monotone mapping, and the sequence {wn} generated by the iterative method wn+1=αnγf(wn+(I-αnTPS(wn-λnG*Gwn converges strongly to w̃ which solves the SEP and the following variational inequality: 〈(T-λfw̃,w-w̃〉≥0 for all w∈S.

  5. Convex variational problems linear, nearly linear and anisotropic growth conditions

    CERN Document Server

    Bildhauer, Michael

    2003-01-01

    The author emphasizes a non-uniform ellipticity condition as the main approach to regularity theory for solutions of convex variational problems with different types of non-standard growth conditions. This volume first focuses on elliptic variational problems with linear growth conditions. Here the notion of a "solution" is not obvious and the point of view has to be changed several times in order to get some deeper insight. Then the smoothness properties of solutions to convex anisotropic variational problems with superlinear growth are studied. In spite of the fundamental differences, a non-uniform ellipticity condition serves as the main tool towards a unified view of the regularity theory for both kinds of problems.

  6. Defining the XML schema matching problem for a personal schema based query answering system

    OpenAIRE

    Smiljanic, M.; van Keulen, Maurice; Jonker, Willem

    2004-01-01

    In this report, we analyze the problem of personal schema matching. We define the ingredients of the XML schema matching problem using constraint logic programming. This allows us to thourougly investigate specific matching problems. We do not have the ambition to provide for a formalism that covers all kinds of schema matching problems. The target is specifically personal schema matching using XML. The report is organized as follows. Chapter 2 provides a detailed description of our research ...

  7. Newton-type methods for optimization and variational problems

    CERN Document Server

    Izmailov, Alexey F

    2014-01-01

    This book presents comprehensive state-of-the-art theoretical analysis of the fundamental Newtonian and Newtonian-related approaches to solving optimization and variational problems. A central focus is the relationship between the basic Newton scheme for a given problem and algorithms that also enjoy fast local convergence. The authors develop general perturbed Newtonian frameworks that preserve fast convergence and consider specific algorithms as particular cases within those frameworks, i.e., as perturbations of the associated basic Newton iterations. This approach yields a set of tools for the unified treatment of various algorithms, including some not of the Newton type per se. Among the new subjects addressed is the class of degenerate problems. In particular, the phenomenon of attraction of Newton iterates to critical Lagrange multipliers and its consequences as well as stabilized Newton methods for variational problems and stabilized sequential quadratic programming for optimization. This volume will b...

  8. Solving the uncalibrated photometric stereo problem using total variation

    DEFF Research Database (Denmark)

    Quéau, Yvain; Lauze, Francois Bernard; Durou, Jean-Denis

    2013-01-01

    In this paper we propose a new method to solve the problem of uncalibrated photometric stereo, making very weak assumptions on the properties of the scene to be reconstructed. Our goal is to solve the generalized bas-relief ambiguity (GBR) by performing a total variation regularization of both...

  9. A Volume Constrained Variational Problem with Lower-Order Terms

    International Nuclear Information System (INIS)

    Morini, M.; Rieger, M.O.

    2003-01-01

    We study a one-dimensional variational problem with two or more level set constraints. The existence of global and local minimizers turns out to be dependent on the regularity of the energy density. A complete characterization of local minimizers and the underlying energy landscape is provided. The Γ -limit when the phases exhaust the whole domain is computed

  10. Optimal Control Problems for Nonlinear Variational Evolution Inequalities

    Directory of Open Access Journals (Sweden)

    Eun-Young Ju

    2013-01-01

    Full Text Available We deal with optimal control problems governed by semilinear parabolic type equations and in particular described by variational inequalities. We will also characterize the optimal controls by giving necessary conditions for optimality by proving the Gâteaux differentiability of solution mapping on control variables.

  11. Efficient algorithm for bifurcation problems of variational inequalities

    International Nuclear Information System (INIS)

    Mittelmann, H.D.

    1983-01-01

    For a class of variational inequalities on a Hilbert space H bifurcating solutions exist and may be characterized as critical points of a functional with respect to the intersection of the level surfaces of another functional and a closed convex subset K of H. In a recent paper [13] we have used a gradient-projection type algorithm to obtain the solutions for discretizations of the variational inequalities. A related but Newton-based method is given here. Global and asymptotically quadratic convergence is proved. Numerical results show that it may be used very efficiently in following the bifurcating branches and that is compares favorably with several other algorithms. The method is also attractive for a class of nonlinear eigenvalue problems (K = H) for which it reduces to a generalized Rayleigh-quotient interaction. So some results are included for the path following in turning-point problems

  12. Variational problems with fractional derivatives: Euler-Lagrange equations

    International Nuclear Information System (INIS)

    Atanackovic, T M; Konjik, S; Pilipovic, S

    2008-01-01

    We generalize the fractional variational problem by allowing the possibility that the lower bound in the fractional derivative does not coincide with the lower bound of the integral that is minimized. Also, for the standard case when these two bounds coincide, we derive a new form of Euler-Lagrange equations. We use approximations for fractional derivatives in the Lagrangian and obtain the Euler-Lagrange equations which approximate the initial Euler-Lagrange equations in a weak sense

  13. Relevance of variation in use of terminology to define generic pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Elize Massard da Fonseca

    2015-02-01

    Full Text Available The World Health Organization (WHO promotes the use of generic drug policies to foster competition in the pharmaceutical sector, reduce drug prices, and increase access to therapeutic drugs. However, little is known about how countries implement these policies. This article describes different terminology adopted by national regulatory authorities to define generic versus proprietary drug products in developing countries, including those in Latin America, and challenges that arise in their application of WHO guidelines, such as labeling issues. The author concludes that variation in generics terminology in these countries is a result of institutional context (i.e., the public sector setting as well as the body of laws and regulations that exists in the country and policy legacies, such as intellectual property regimes, and highlights the need for further analysis of pharmaceutical regulations to improve understanding of the barriers and political implications of generic drug policies.

  14. Relevance of variation in use of terminology to define generic pharmaceutical products.

    Science.gov (United States)

    Fonseca, Elize Massard da

    2015-02-01

    The World Health Organization (WHO) promotes the use of generic drug policies to foster competition in the pharmaceutical sector, reduce drug prices, and increase access to therapeutic drugs. However, little is known about how countries implement these policies. This article describes different terminology adopted by national regulatory authorities to define generic versus proprietary drug products in developing countries, including those in Latin America, and challenges that arise in their application of WHO guidelines, such as labeling issues. The author concludes that variation in generics terminology in these countries is a result of institutional context (i.e., the public sector setting as well as the body of laws and regulations that exists in the country) and policy legacies, such as intellectual property regimes, and highlights the need for further analysis of pharmaceutical regulations to improve understanding of the barriers and political implications of generic drug policies.

  15. An Adaptive Approach to Variational Nodal Diffusion Problems

    International Nuclear Information System (INIS)

    Zhang Hui; Lewis, E.E.

    2001-01-01

    An adaptive grid method is presented for the solution of neutron diffusion problems in two dimensions. The primal hybrid finite elements employed in the variational nodal method are used to reduce the diffusion equation to a coupled set of elemental response matrices. An a posteriori error estimator is developed to indicate the magnitude of local errors stemming from the low-order elemental interface approximations. An iterative procedure is implemented in which p refinement is applied locally by increasing the polynomial order of the interface approximations. The automated algorithm utilizes the a posteriori estimator to achieve local error reductions until an acceptable level of accuracy is reached throughout the problem domain. Application to a series of X-Y benchmark problems indicates the reduction of computational effort achievable by replacing uniform with adaptive refinement of the spatial approximations

  16. Practice variation in defining sentinel lymph nodes on lymphoscintigrams in oral cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Flach, Geke B.; Bree, Remco de [VU University Medical Center, Department of Otolaryngology-Head and Neck Surgery, De Boelelaan 1117, 1081 HV Amsterdam, PO Box 7057, Amsterdam (Netherlands); Schie, Annelies van; Hoekstra, Otto S. [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Witte, Birgit I. [VU University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); Olmos, Renato A.V. [VU University Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Klop, W.M.C. [Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Head and Neck Surgery and Oncology, Amsterdam (Netherlands)

    2014-12-15

    Lymphoscintigraphic imaging and adequate interpretation of the lymphatic drainage pattern is an essential step in the sentinel lymph node biopsy (SLNB) procedure. In oral cancer, identification of the sentinel lymph node (SLN) can be challenging. In this study, interobserver variability in defining SLNs on lymphoscintigrams was evaluated in patients with T1-T2 stage N0 oral cancer. Sixteen observers (head and neck surgeons, nuclear medicine physicians or teams of both) from various institutes were asked which criteria they use to consider a hot focus on the lymphoscintigram as SLN. Lymphoscintigrams of 9 patients with 47 hot foci (3-9 per patient) were assessed, using a scale of 'yes/equivocal/no'. Bilateral drainage was seen in four of nine cases. In three cases additional late single photon emission computed tomography (SPECT)/CT scanning was performed. Interobserver variability was evaluated by kappa (κ) analysis, using linear weighted pairwise comparison of the observers. Conservative (equivocal analysed as no) and sensitive (equivocal analysed as yes) assessment strategies were investigated using pairwise kappa analysis. Various definitions of SLN on lymphoscintigrams were given. Interobserver variability of all cases using a 3-point scale showed fair agreement (71 %, κ{sub w} = 0.29). The conservative and sensitive analyses both showed moderate agreement: conservative approach κ = 0.44 (in 80 % of the hot foci the observers agreed) and sensitive approach κ = 0.42 (81 %) respectively. Multidisciplinary involvement in image interpretation and higher levels of observer experience appeared to increase agreement. Among 16 observers, there is practice variation in defining SLNs on lymphoscintigrams in oral cancer patients. Interobserver variability of lymphoscintigraphic interpretation shows moderate agreement. In order to achieve better agreement in defining SLNs on lymphoscintigrams specific guidelines are warranted. (orig.)

  17. Practice variation in defining sentinel lymph nodes on lymphoscintigrams in oral cancer patients

    International Nuclear Information System (INIS)

    Flach, Geke B.; Bree, Remco de; Schie, Annelies van; Hoekstra, Otto S.; Witte, Birgit I.; Olmos, Renato A.V.; Klop, W.M.C.

    2014-01-01

    Lymphoscintigraphic imaging and adequate interpretation of the lymphatic drainage pattern is an essential step in the sentinel lymph node biopsy (SLNB) procedure. In oral cancer, identification of the sentinel lymph node (SLN) can be challenging. In this study, interobserver variability in defining SLNs on lymphoscintigrams was evaluated in patients with T1-T2 stage N0 oral cancer. Sixteen observers (head and neck surgeons, nuclear medicine physicians or teams of both) from various institutes were asked which criteria they use to consider a hot focus on the lymphoscintigram as SLN. Lymphoscintigrams of 9 patients with 47 hot foci (3-9 per patient) were assessed, using a scale of 'yes/equivocal/no'. Bilateral drainage was seen in four of nine cases. In three cases additional late single photon emission computed tomography (SPECT)/CT scanning was performed. Interobserver variability was evaluated by kappa (κ) analysis, using linear weighted pairwise comparison of the observers. Conservative (equivocal analysed as no) and sensitive (equivocal analysed as yes) assessment strategies were investigated using pairwise kappa analysis. Various definitions of SLN on lymphoscintigrams were given. Interobserver variability of all cases using a 3-point scale showed fair agreement (71 %, κ w = 0.29). The conservative and sensitive analyses both showed moderate agreement: conservative approach κ = 0.44 (in 80 % of the hot foci the observers agreed) and sensitive approach κ = 0.42 (81 %) respectively. Multidisciplinary involvement in image interpretation and higher levels of observer experience appeared to increase agreement. Among 16 observers, there is practice variation in defining SLNs on lymphoscintigrams in oral cancer patients. Interobserver variability of lymphoscintigraphic interpretation shows moderate agreement. In order to achieve better agreement in defining SLNs on lymphoscintigrams specific guidelines are warranted. (orig.)

  18. Convergence Properties of Projection and Contraction Methods for Variational Inequality Problems

    International Nuclear Information System (INIS)

    Xiu, N.; Wang, C.; Zhang, J.

    2001-01-01

    In this paper we develop the convergence theory of a general class of projection and contraction algorithms (PC method), where an extended stepsize rule is used, for solving variational inequality (VI) problems. It is shown that, by defining a scaled projection residue, the PC method forces the sequence of the residues to zero. It is also shown that, by defining a projected function, the PC method forces the sequence of projected functions to zero. A consequence of this result is that if the PC method converges to a nondegenerate solution of the VI problem, then after a finite number of iterations, the optimal face is identified. Finally, we study local convergence behavior of the extragradient algorithm for solving the KKT system of the inequality constrained VI problem

  19. THE CONTROL VARIATIONAL METHOD FOR ELASTIC CONTACT PROBLEMS

    Directory of Open Access Journals (Sweden)

    Mircea Sofonea

    2010-07-01

    Full Text Available We consider a multivalued equation of the form Ay + F(y = fin a real Hilbert space, where A is a linear operator and F represents the (Clarke subdifferential of some function. We prove existence and uniqueness results of the solution by using the control variational method. The main idea in this method is to minimize the energy functional associated to the nonlinear equation by arguments of optimal control theory. Then we consider a general mathematical model describing the contact between a linearly elastic body and an obstacle which leads to a variational formulation as above, for the displacement field. We apply the abstract existence and uniqueness results to prove the unique weak solvability of the corresponding contact problem. Finally, we present examples of contact and friction laws for which our results work.

  20. Nonlinear Eigenvalue Problems in Elliptic Variational Inequalities: a local study

    International Nuclear Information System (INIS)

    Conrad, F.; Brauner, C.; Issard-Roch, F.; Nicolaenko, B.

    1985-01-01

    The authors consider a class of Nonlinear Eigenvalue Problems (N.L.E.P.) associated with Elliptic Variational Inequalities (E.V.I.). First the authors introduce the main tools for a local study of branches of solutions; the authors extend the linearization process required in the case of equations. Next the authors prove the existence of arcs of solutions close to regular vs singular points, and determine their local behavior up to the first order. Finally, the authors discuss the connection between their regularity condition and some stability concept. 37 references, 6 figures

  1. A variational Bayesian method to inverse problems with impulsive noise

    KAUST Repository

    Jin, Bangti

    2012-01-01

    We propose a novel numerical method for solving inverse problems subject to impulsive noises which possibly contain a large number of outliers. The approach is of Bayesian type, and it exploits a heavy-tailed t distribution for data noise to achieve robustness with respect to outliers. A hierarchical model with all hyper-parameters automatically determined from the given data is described. An algorithm of variational type by minimizing the Kullback-Leibler divergence between the true posteriori distribution and a separable approximation is developed. The numerical method is illustrated on several one- and two-dimensional linear and nonlinear inverse problems arising from heat conduction, including estimating boundary temperature, heat flux and heat transfer coefficient. The results show its robustness to outliers and the fast and steady convergence of the algorithm. © 2011 Elsevier Inc.

  2. A new class of problems in the calculus of variations

    Science.gov (United States)

    Ekeland, Ivar; Long, Yiming; Zhou, Qinglong

    2013-11-01

    This paper investigates an infinite-horizon problem in the one-dimensional calculus of variations, arising from the Ramsey model of endogeneous economic growth. Following Chichilnisky, we introduce an additional term, which models concern for the well-being of future generations. We show that there are no optimal solutions, but that there are equilibrium strateges, i.e. Nash equilibria of the leader-follower game between successive generations. To solve the problem, we approximate the Chichilnisky criterion by a biexponential criterion, we characterize its equilibria by a pair of coupled differential equations of HJB type, and we go to the limit. We find all the equilibrium strategies for the Chichilnisky criterion. The mathematical analysis is difficult because one has to solve an implicit differential equation in the sense of Thom. Our analysis extends earlier work by Ekeland and Lazrak.

  3. Essays on variational approximation techniques for stochastic optimization problems

    Science.gov (United States)

    Deride Silva, Julio A.

    This dissertation presents five essays on approximation and modeling techniques, based on variational analysis, applied to stochastic optimization problems. It is divided into two parts, where the first is devoted to equilibrium problems and maxinf optimization, and the second corresponds to two essays in statistics and uncertainty modeling. Stochastic optimization lies at the core of this research as we were interested in relevant equilibrium applications that contain an uncertain component, and the design of a solution strategy. In addition, every stochastic optimization problem relies heavily on the underlying probability distribution that models the uncertainty. We studied these distributions, in particular, their design process and theoretical properties such as their convergence. Finally, the last aspect of stochastic optimization that we covered is the scenario creation problem, in which we described a procedure based on a probabilistic model to create scenarios for the applied problem of power estimation of renewable energies. In the first part, Equilibrium problems and maxinf optimization, we considered three Walrasian equilibrium problems: from economics, we studied a stochastic general equilibrium problem in a pure exchange economy, described in Chapter 3, and a stochastic general equilibrium with financial contracts, in Chapter 4; finally from engineering, we studied an infrastructure planning problem in Chapter 5. We stated these problems as belonging to the maxinf optimization class and, in each instance, we provided an approximation scheme based on the notion of lopsided convergence and non-concave duality. This strategy is the foundation of the augmented Walrasian algorithm, whose convergence is guaranteed by lopsided convergence, that was implemented computationally, obtaining numerical results for relevant examples. The second part, Essays about statistics and uncertainty modeling, contains two essays covering a convergence problem for a sequence

  4. Variational Bayes and a problem of reliable communication: II. Infinite systems

    International Nuclear Information System (INIS)

    Newton, Nigel J; Mitter, Sanjoy K

    2012-01-01

    We consider a family of estimation problems not admitting conventional analysis because of singularity and measurability issues. We define posterior distributions for the family by a variational technique analogous to that used to define Gibbs measures in statistical mechanics. The family of estimation problems, which arise in the asymptotic analysis of error-control codes, is parametrized by a code rate, R∈(0,∞); this is shown to be analogous to the absolute temperature of statistical mechanics. The family undergoes an (Ehrenfest) first-order phase transition at a critical code rate C (the channel capacity), where there is a convex set of posterior distributions. At all other code rates, there is only one posterior distribution; if R C it has infinite support. In a result reflecting the Dobrushin construction, we show that these posterior distributions are asymptotically consistent with those of families of finite-sequence error-control codes. (paper)

  5. Variational problems arising in classical mechanics and nonlinear elasticity

    International Nuclear Information System (INIS)

    Spencer, P.

    1999-01-01

    In this thesis we consider two different classes of variational problems. First, one-dimensional problems arising from classical mechanics where the problem is to determine whether there is a unique function η 0 (x) which minimises the energy functional of the form I(η) = ∫ a b L(x,η(x), η'(x)) dx. We will investigate uniqueness by making a change of dependent and independent variables and showing that for a class of integrands L with a particular kind of scaling invariance the resulting integrand is completely convex. The change of variables arises by applying results from Lie group theory as applied in the study of differential equations and this work is motivated by [60] and [68]. Second, the problem of minimising energy functionals of the form E(u) = ∫ A W(∇u(x)) dx in the case of a nonlinear elastic body occupying an annular region A contains R 2 with u : A-bar → A-bar. This work is motivated by [57] (in particular the example of paragraph 4). We will consider rotationally symmetric deformations satisfying prescribed boundary conditions. We will show the existence of minimisers for stored energy functions of the form W(F) = g-tilde(vertical bar-F-vertical bar, det(F)) in a class of general rotationally symmetric deformations of a compressible annulus and for stored energy functions of the form W(F) = g-bar(vertical bar-F-vertical bar) in a class of rotationally symmetric deformations of an incompressible annulus. We will also show that in each case the minimisers are solutions of the full equilibrium equations. A model problem will be considered where the energy functional is the Dirichlet integral and it will be shown that the rotationally symmetric solution obtained is a minimiser among admissible non-rotationally symmetric deformations. In the case of an incompressible annulus, we will consider the Dirichlet integral as the energy functional and show that the rotationally symmetric equilibrium solutions in this case are weak local minimisers in

  6. The problem of defining contemporary right-wing extremism in political theory

    Directory of Open Access Journals (Sweden)

    Đorić Marija

    2016-01-01

    Full Text Available The subject matter of research in this paper is theoretical controversy related to the definition of right-wing extremism. Given the fact that extremism is a variable, amorphous and insufficiently researched phenomenon, largely conditioned by time, space, political and cultural differences, there is a great confusion in the field of political science when defining right-wing extremism. The problem of researching right-wing extremism is additionally complicated by various terms that are being used in the contemporary literature as its synonyms, such as right-wing radicalism, neo-Fascism, ultra-radicalism, etc. In order to provide the most valid theoretical determination of right-wing extremism, the author provides a detailed analysis of all the components constituting this phenomenon and examines their causality. In the political praxis, the term extremism is extensively abused, which additionally complicates its determination. Videlicet, politicians often use term 'extremist' in order to discredit their political opponents. While during the French revolution aristocracy saw the bourgeoisie as extremists, the members of the working class later stated that the bourgeoisie were extremists. The problem lies in the fact that, in politics, extremists are not only the ones who use violence as modus operandi; indeed, it is also used by political opponents who do not belong to the extreme political option. Another aggravating factor in defining right-wing extremism is that many administrative and academic definitions do not make a clear distinction between extremism and related phenomena, such as terrorism, radicalism and populism. Extremism is most often equaled with terrorism, which gives rise to another problem in defining this phenomenon. The relation between extremism and terrorism is the relation of general and specific. Namely, every act of terrorism is concurrently considered to be an act of extremism, but not vice versa, given the fact that

  7. From a Nonlinear, Nonconvex Variational Problem to a Linear, Convex Formulation

    International Nuclear Information System (INIS)

    Egozcue, J.; Meziat, R.; Pedregal, P.

    2002-01-01

    We propose a general approach to deal with nonlinear, nonconvex variational problems based on a reformulation of the problem resulting in an optimization problem with linear cost functional and convex constraints. As a first step we explicitly explore these ideas to some one-dimensional variational problems and obtain specific conclusions of an analytical and numerical nature

  8. Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome

    NARCIS (Netherlands)

    Collins, Ryan L; Brand, Harrison; Redin, Claire E.; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T.; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A.; Lucente, Diane; Levy, Brynn; Sanders, Jan-Stephan; Wapner, Ronald J.; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E.

    2017-01-01

    Background: Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. Results: We sequenced 689 participants with autism spectrum disorder (ASD) and other

  9. Variational methods applied to problems of diffusion and reaction

    CERN Document Server

    Strieder, William

    1973-01-01

    This monograph is an account of some problems involving diffusion or diffusion with simultaneous reaction that can be illuminated by the use of variational principles. It was written during a period that included sabbatical leaves of one of us (W. S. ) at the University of Minnesota and the other (R. A. ) at the University of Cambridge and we are grateful to the Petroleum Research Fund for helping to support the former and the Guggenheim Foundation for making possible the latter. We would also like to thank Stephen Prager for getting us together in the first place and for showing how interesting and useful these methods can be. We have also benefitted from correspondence with Dr. A. M. Arthurs of the University of York and from the counsel of Dr. B. D. Coleman the general editor of this series. Table of Contents Chapter 1. Introduction and Preliminaries . 1. 1. General Survey 1 1. 2. Phenomenological Descriptions of Diffusion and Reaction 2 1. 3. Correlation Functions for Random Suspensions 4 1. 4. Mean Free ...

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

    Directory of Open Access Journals (Sweden)

    Phayap Katchang

    2010-01-01

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

  11. A function space framework for structural total variation regularization with applications in inverse problems

    Science.gov (United States)

    Hintermüller, Michael; Holler, Martin; Papafitsoros, Kostas

    2018-06-01

    In this work, we introduce a function space setting for a wide class of structural/weighted total variation (TV) regularization methods motivated by their applications in inverse problems. In particular, we consider a regularizer that is the appropriate lower semi-continuous envelope (relaxation) of a suitable TV type functional initially defined for sufficiently smooth functions. We study examples where this relaxation can be expressed explicitly, and we also provide refinements for weighted TV for a wide range of weights. Since an integral characterization of the relaxation in function space is, in general, not always available, we show that, for a rather general linear inverse problems setting, instead of the classical Tikhonov regularization problem, one can equivalently solve a saddle-point problem where no a priori knowledge of an explicit formulation of the structural TV functional is needed. In particular, motivated by concrete applications, we deduce corresponding results for linear inverse problems with norm and Poisson log-likelihood data discrepancy terms. Finally, we provide proof-of-concept numerical examples where we solve the saddle-point problem for weighted TV denoising as well as for MR guided PET image reconstruction.

  12. Influences of spatial and temporal variation on fish-habitat relationships defined by regression quantiles

    Science.gov (United States)

    Dunham, J.B.; Cade, B.S.; Terrell, J.W.

    2002-01-01

    We used regression quantiles to model potentially limiting relationships between the standing crop of cutthroat trout Oncorhynchus clarki and measures of stream channel morphology. Regression quantile models indicated that variation in fish density was inversely related to the width:depth ratio of streams but not to stream width or depth alone. The spatial and temporal stability of model predictions were examined across years and streams, respectively. Variation in fish density with width:depth ratio (10th-90th regression quantiles) modeled for streams sampled in 1993-1997 predicted the variation observed in 1998-1999, indicating similar habitat relationships across years. Both linear and nonlinear models described the limiting relationships well, the latter performing slightly better. Although estimated relationships were transferable in time, results were strongly dependent on the influence of spatial variation in fish density among streams. Density changes with width:depth ratio in a single stream were responsible for the significant (P 80th). This suggests that stream-scale factors other than width:depth ratio play a more direct role in determining population density. Much of the variation in densities of cutthroat trout among streams was attributed to the occurrence of nonnative brook trout Salvelinus fontinalis (a possible competitor) or connectivity to migratory habitats. Regression quantiles can be useful for estimating the effects of limiting factors when ecological responses are highly variable, but our results indicate that spatiotemporal variability in the data should be explicitly considered. In this study, data from individual streams and stream-specific characteristics (e.g., the occurrence of nonnative species and habitat connectivity) strongly affected our interpretation of the relationship between width:depth ratio and fish density.

  13. Variations in Humanized and Defined Culture Conditions Supporting Derivation of New Human Embryonic Stem Cell Lines

    DEFF Research Database (Denmark)

    Fletcher, Judy M; Ferrier, Patricia M; Gardner, John O

    2006-01-01

    matrix substrate of purified human laminin (Ln) with transitional reliance on mitotically inactivated human fibroblast (HDF) feeder cells. With this integrated system hESC lines were isolated using either HDF conditioned medium supplemented with a bovine-sourced serum replacement (bSRM), or a defined...

  14. Problems of phenomenological simulation of the Dst variation

    International Nuclear Information System (INIS)

    Gul'el'mi, A.V.

    1988-01-01

    Stochastic generalization of RBM model, describing the D st -variation is suggested. The corresponding Fokker-Planck equation contains a new phenomenological parameter enabling to obtain the interval estimation of D st forecast. The structure of sources and sinks forming the D st -variation is considered from the viewpoint of critical phenomenon theory

  15. Ill-defined problem solving in amnestic mild cognitive impairment: linking episodic memory to effective solution generation.

    Science.gov (United States)

    Sheldon, S; Vandermorris, S; Al-Haj, M; Cohen, S; Winocur, G; Moscovitch, M

    2015-02-01

    It is well accepted that the medial temporal lobes (MTL), and the hippocampus specifically, support episodic memory processes. Emerging evidence suggests that these processes also support the ability to effectively solve ill-defined problems which are those that do not have a set routine or solution. To test the relation between episodic memory and problem solving, we examined the ability of individuals with single domain amnestic mild cognitive impairment (aMCI), a condition characterized by episodic memory impairment, to solve ill-defined social problems. Participants with aMCI and age and education matched controls were given a battery of tests that included standardized neuropsychological measures, the Autobiographical Interview (Levine et al., 2002) that scored for episodic content in descriptions of past personal events, and a measure of ill-defined social problem solving. Corroborating previous findings, the aMCI group generated less episodically rich narratives when describing past events. Individuals with aMCI also generated less effective solutions when solving ill-defined problems compared to the control participants. Correlation analyses demonstrated that the ability to recall episodic elements from autobiographical memories was positively related to the ability to effectively solve ill-defined problems. The ability to solve these ill-defined problems was related to measures of activities of daily living. In conjunction with previous reports, the results of the present study point to a new functional role of episodic memory in ill-defined goal-directed behavior and other non-memory tasks that require flexible thinking. Our findings also have implications for the cognitive and behavioural profile of aMCI by suggesting that the ability to effectively solve ill-defined problems is related to sustained functional independence. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Defining Allowable Physical Property Variations for High Accurate Measurements on Polymer Parts

    DEFF Research Database (Denmark)

    Mohammadi, Ali; Sonne, Mads Rostgaard; Madruga, Daniel González

    2015-01-01

    Measurement conditions and material properties have a significant impact on the dimensions of a part, especially for polymers parts. Temperature variation causes part deformations that increase the uncertainty of the measurement process. Current industrial tolerances of a few micrometres demand...... high accurate measurements in non-controlled ambient. Most of polymer parts are manufactured by injection moulding and their inspection is carried out after stabilization, around 200 hours. The overall goal of this work is to reach ±5μm in uncertainty measurements a polymer products which...

  17. Unilateral contact problems variational methods and existence theorems

    CERN Document Server

    Eck, Christof; Krbec, Miroslav

    2005-01-01

    The mathematical analysis of contact problems, with or without friction, is an area where progress depends heavily on the integration of pure and applied mathematics. This book presents the state of the art in the mathematical analysis of unilateral contact problems with friction, along with a major part of the analysis of dynamic contact problems without friction. Much of this monograph emerged from the authors'' research activities over the past 10 years and deals with an approach proven fruitful in many situations. Starting from thin estimates of possible solutions, this approach is based on an approximation of the problem and the proof of a moderate partial regularity of the solution to the approximate problem. This in turn makes use of the shift (or translation) technique - an important yet often overlooked tool for contact problems and other nonlinear problems with limited regularity. The authors pay careful attention to quantification and precise results to get optimal bounds in sufficient conditions f...

  18. Chondrocyte heterogeneity: immunohistologically defined variation of integrin expression at different sites in human fetal knees.

    Science.gov (United States)

    Salter, D M; Godolphin, J L; Gourlay, M S

    1995-04-01

    During development and at maturity different forms of cartilage vary in morphology and macromolecular content. This reflects heterogeneity of chondrocyte activity, in part involving differential interactions with the adjacent extracellular matrix via specialized cell surface receptors such as integrins. We undertook an immunohistological study on a series of human fetal knee joints to assess variation in the expression of integrins by chondrocytes and potential matrix ligands in articular, epiphyseal, growth plate, and meniscal cartilage. The results show that articular chondrocytes (beta 1+, beta 5 alpha V+, alpha 1+, alpha 2+/-, alpha 5+, weakly alpha 6+, alpha V+) differed from epiphyseal (beta 1+, beta 5 alpha V+, alpha 1+/-, alpha 2+/-, alpha 5+, alpha 6+, alpha V+) growth plate (beta 1+, beta 5 alpha V+, alpha 1-, alpha 2-, alpha 5+, alpha 6+, alpha V+), and meniscal cells (beta 1+, beta 5 alpha V+, alpha 1+, strongly alpha 2+, alpha 5+, alpha 6+, alpha V+ in expression of integrin subunits. There was no expression of beta 3, beta 4, beta 6, or alpha 3 by chondrocytes. These results differ from previous reports on the expression of integrins by adult articular cartilage, where alpha 2 and alpha 6 are not seen. Variation in distribution of matrix ligands was also seen. Fibronectin, laminin and Type VI collagen were expressed in all cartilages but there was restricted expression of tenascin, ED-A and ED-B fibronectin isoforms (articular cartilage and meniscus), and vitronectin (absent from growth plate cartilage). Regulated expression of integrins by chondrocytes, associated with changes in the pericellular matrix composition, is of potential importance in control of cartilage differentiation and function in health and disease.

  19. Optimization of the variational basis in the three body problem

    International Nuclear Information System (INIS)

    Simenog, I.V.; Pushkash, O.M.; Bestuzheva, A.B.

    1995-01-01

    The procedure of variational oscillator basis optimization is proposed to the calculation the energy spectra of three body systems. The hierarchy of basis functions is derived and energies of ground and excited states for three gravitating particles is obtained with high accuracy. 12 refs

  20. Presymplectic current and the inverse problem of the calculus of variations

    NARCIS (Netherlands)

    Khavkine, I.

    2013-01-01

    The inverse problem of the calculus of variations asks whether a given system of partial differential equations (PDEs) admits a variational formulation. We show that the existence of a presymplectic form in the variational bicomplex, when horizontally closed on solutions, allows us to construct a

  1. General Criteria to Evaluate Students' Performance in Dealing with Ill-Defined Problems

    National Research Council Canada - National Science Library

    Peterson, Donna

    1998-01-01

    .... The purpose of constructing ill defined assessment tasks for our students is to assess their ability to recognize and contribute to the resolution of real world dilemmas they are likely to face...

  2. The uniqueness of the solution for the definite problem of a parabolic variational inequality

    Directory of Open Access Journals (Sweden)

    Liping Song

    2016-12-01

    Full Text Available Abstract The uniqueness of the solution for the definite problem of a parabolic variational inequality is proved. The problem comes from the study of the optimal exercise strategies for the perpetual executive stock options with unrestricted exercise in financial market. Because the variational inequality is degenerate and the obstacle condition contains the partial derivative of an unknown function, it makes the theoretical study of the definite problem of the variational inequality problem very difficult. Firstly, the property which the value function satisfies is derived by applying the Jensen inequality. Then the uniqueness of the solution is proved by using this property and maximum principles.

  3. A variational Bayesian method to inverse problems with impulsive noise

    KAUST Repository

    Jin, Bangti

    2012-01-01

    We propose a novel numerical method for solving inverse problems subject to impulsive noises which possibly contain a large number of outliers. The approach is of Bayesian type, and it exploits a heavy-tailed t distribution for data noise to achieve

  4. On a variational approach to truncated problems of moments

    Czech Academy of Sciences Publication Activity Database

    Ambrozie, Calin-Grigore

    2013-01-01

    Roč. 138, č. 1 (2013), s. 105-112 ISSN 0862-7959 R&D Projects: GA AV ČR IAA100190903 Institutional support: RVO:67985840 Keywords : problem of moments * representing measure Subject RIV: BA - General Mathematics http://www.dml.cz/handle/10338.dmlcz/143233

  5. Minimization of Linear Functionals Defined on| Solutions of Large-Scale Discrete Ill-Posed Problems

    DEFF Research Database (Denmark)

    Elden, Lars; Hansen, Per Christian; Rojas, Marielba

    2003-01-01

    The minimization of linear functionals de ned on the solutions of discrete ill-posed problems arises, e.g., in the computation of con dence intervals for these solutions. In 1990, Elden proposed an algorithm for this minimization problem based on a parametric-programming reformulation involving...... the solution of a sequence of trust-region problems, and using matrix factorizations. In this paper, we describe MLFIP, a large-scale version of this algorithm where a limited-memory trust-region solver is used on the subproblems. We illustrate the use of our algorithm in connection with an inverse heat...

  6. Convex Minimization with Constraints of Systems of Variational Inequalities, Mixed Equilibrium, Variational Inequality, and Fixed Point Problems

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We introduce and analyze one iterative algorithm by hybrid shrinking projection method for finding a solution of the minimization problem for a convex and continuously Fréchet differentiable functional, with constraints of several problems: finitely many generalized mixed equilibrium problems, finitely many variational inequalities, the general system of variational inequalities and the fixed point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another iterative algorithm by hybrid shrinking projection method for finding a fixed point of infinitely many nonexpansive mappings with the same constraints, and derive its strong convergence under mild assumptions.

  7. A Duality Approach for the Boundary Variation of Neumann Problems

    DEFF Research Database (Denmark)

    Bucur, Dorin; Varchon, Nicolas

    2002-01-01

    In two dimensions, we study the stability of the solution of an elliptic equation with Neumann boundary conditions for nonsmooth perturbations of the geometric domain. Using harmonic conjugates, we relate this problem to the shape stability of the solution of an elliptic equation with Dirichlet b...... boundary conditions. As a particular case, we prove the stability of the solution under a topological constraint ( uniform number of holes), which is analogous to Sverak's result for Dirichlet boundary conditions....

  8. A duality approach or the boundary variation of Neumann problems

    DEFF Research Database (Denmark)

    Bucur, D.; Varchon, Nicolas

    2002-01-01

    In two dimensions, we study the stability of the solution of an elliptic equation with Neumann boundary conditions for nonsmooth perturbations of the geometric domain. Using harmonic conjugates, we relate this problem to the shape stability of the solution of an elliptic equation with Dirichlet b...... boundary conditions. As a particular case, we prove the stability of the solution under a topological constraint ( uniform number of holes), which is analogous to Sverak's result for Dirichlet boundary conditions....

  9. Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

    Science.gov (United States)

    Taylor, Wendy; Stacey, Kaye

    2014-01-01

    This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

  10. Application of He's variational iteration method to the fifth-order boundary value problems

    International Nuclear Information System (INIS)

    Shen, S

    2008-01-01

    Variational iteration method is introduced to solve the fifth-order boundary value problems. This method provides an efficient approach to solve this type of problems without discretization and the computation of the Adomian polynomials. Numerical results demonstrate that this method is a promising and powerful tool for solving the fifth-order boundary value problems

  11. The inverse problem of the calculus of variations for discrete systems

    Science.gov (United States)

    Barbero-Liñán, María; Farré Puiggalí, Marta; Ferraro, Sebastián; Martín de Diego, David

    2018-05-01

    We develop a geometric version of the inverse problem of the calculus of variations for discrete mechanics and constrained discrete mechanics. The geometric approach consists of using suitable Lagrangian and isotropic submanifolds. We also provide a transition between the discrete and the continuous problems and propose variationality as an interesting geometric property to take into account in the design and computer simulation of numerical integrators for constrained systems. For instance, nonholonomic mechanics is generally non variational but some special cases admit an alternative variational description. We apply some standard nonholonomic integrators to such an example to study which ones conserve this property.

  12. The Criterion A problem revisited: controversies and challenges in defining and measuring psychological trauma.

    Science.gov (United States)

    Weathers, Frank W; Keane, Terence M

    2007-04-01

    The Criterion A problem in the field of traumatic stress refers to the stressor criterion for posttraumatic stress disorder (PTSD) and involves a number of fundamental issues regarding the definition and measurement of psychological trauma. These issues first emerged with the introduction of PTSD as a diagnostic category in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III; American Psychiatric Association, 1980) and continue to generate considerable controversy. In this article, the authors provide an update on the Criterion A problem, with particular emphasis on the evolution of the DSM definition of the stressor criterion and the ongoing debate regarding broad versus narrow conceptualizations of traumatic events.

  13. Defining transmedia narrative: problems and questions. Dialogue with Mary-Laure Ryan

    Directory of Open Access Journals (Sweden)

    Franco Passalacqua

    2011-07-01

    Full Text Available In this interview Mary-Laure Ryan faces some problems that arise from her definition of «transmedia narrative». Can every semiotic system tell stories? How can we elaborate a definition of «narrative» which accounts both for cognitive and semantic aspects? How can we dispense with the syntactic level if we need a definition of «narrativity» that suits every semiotic system? Answering these questions, Ryan deals with other proposals developed around the same theoretical problems, and points out a thought-provoking argument against Meir Sternberg’s functionalist definition of narrative.

  14. Error Analysis of Variations on Larsen's Benchmark Problem

    International Nuclear Information System (INIS)

    Azmy, YY

    2001-01-01

    Error norms for three variants of Larsen's benchmark problem are evaluated using three numerical methods for solving the discrete ordinates approximation of the neutron transport equation in multidimensional Cartesian geometry. The three variants of Larsen's test problem are concerned with the incoming flux boundary conditions: unit incoming flux on the left and bottom edges (Larsen's configuration); unit, incoming flux only on the left edge; unit incoming flux only on the bottom edge. The three methods considered are the Diamond Difference (DD) method, and the constant-approximation versions of the Arbitrarily High Order Transport method of the Nodal type (AHOT-N), and of the Characteristic (AHOT-C) type. The cell-wise error is computed as the difference between the cell-averaged flux computed by each method and the exact value, then the L 1 , L 2 , and L ∞ error norms are calculated. The results of this study demonstrate that while integral error norms, i.e. L 1 , L 2 , converge to zero with mesh refinement, the pointwise L ∞ norm does not due to solution discontinuity across the singular characteristic. Little difference is observed between the error norm behavior of the three methods considered in spite of the fact that AHOT-C is locally exact, suggesting that numerical diffusion across the singular characteristic as the major source of error on the global scale. However, AHOT-C possesses a given accuracy in a larger fraction of computational cells than DD

  15. L{sup {infinity}} Variational Problems with Running Costs and Constraints

    Energy Technology Data Exchange (ETDEWEB)

    Aronsson, G., E-mail: gunnar.aronsson@liu.se [Linkoeping University, Department of Mathematics (Sweden); Barron, E. N., E-mail: enbarron@math.luc.edu [Loyola University of Chicago, Department of Mathematics and Statistics (United States)

    2012-02-15

    Various approaches are used to derive the Aronsson-Euler equations for L{sup {infinity}} calculus of variations problems with constraints. The problems considered involve holonomic, nonholonomic, isoperimetric, and isosupremic constraints on the minimizer. In addition, we derive the Aronsson-Euler equation for the basic L{sup {infinity}} problem with a running cost and then consider properties of an absolute minimizer. Many open problems are introduced for further study.

  16. On the minimizers of calculus of variations problems in Hilbert spaces

    KAUST Repository

    Gomes, Diogo A.

    2014-01-19

    The objective of this paper is to discuss existence, uniqueness and regularity issues of minimizers of one dimensional calculus of variations problem in Hilbert spaces. © 2014 Springer-Verlag Berlin Heidelberg.

  17. Minimizers of a Class of Constrained Vectorial Variational Problems: Part I

    KAUST Repository

    Hajaiej, Hichem; Markowich, Peter A.; Trabelsi, Saber

    2014-01-01

    In this paper, we prove the existence of minimizers of a class of multiconstrained variational problems. We consider systems involving a nonlinearity that does not satisfy compactness, monotonicity, neither symmetry properties. Our approach hinges

  18. On the minimizers of calculus of variations problems in Hilbert spaces

    KAUST Repository

    Gomes, Diogo A.; Nurbekyan, Levon

    2014-01-01

    The objective of this paper is to discuss existence, uniqueness and regularity issues of minimizers of one dimensional calculus of variations problem in Hilbert spaces. © 2014 Springer-Verlag Berlin Heidelberg.

  19. Optimality Bounds for a Variational Relaxation of the Image Partitioning Problem

    KAUST Repository

    Lellmann, Jan; Lenzen, Frank; Schnö rr, Christoph

    2012-01-01

    We consider a variational convex relaxation of a class of optimal partitioning and multiclass labeling problems, which has recently proven quite successful and can be seen as a continuous analogue of Linear Programming (LP) relaxation methods

  20. Defining Solutions, Finding Problems: Deforestation, Gender, and REDD+ in Burkina Faso

    Directory of Open Access Journals (Sweden)

    Lisa Westholm

    2015-01-01

    Full Text Available Reducing Emissions from Deforestation and Degradation (REDD+ is a policy instrument meant to mitigate climate change while also achieving poverty reduction in tropical countries. It has garnered critics for homogenising environmental and development governance and for ignoring how similar efforts have tended to exacerbate gender inequalities. Nonetheless, regarding such schemes as inevitable, some feminists argue for requirements that include women′s empowerment and participation. In this paper we move beyond discussions about safeguards and examine whether the very framing of REDD+ programs can provide openings for a transformation as argued for by its proponents. Following the REDD+ policy process in Burkina Faso, we come to two important insights: REDD+ is a solution in need of a problem. Assumptions about gender are at the heart of creating ′actionable knowledge′ that enabled REDD+ to be presented as a policy solution to the problems of deforestation, poverty and gender inequality. Second, despite its ′safeguards′, REDD+ appears to be perpetuating gendered divisions of labour, as formal environmental decision-making moves upwards; and responsibility and the burden of actual environmental labour shifts further down in particularly gendered ways. We explore how this is enabled by the development of policies whose stated aims are to tackle inequalities.

  1. Triple Hierarchical Variational Inequalities with Constraints of Mixed Equilibria, Variational Inequalities, Convex Minimization, and Hierarchical Fixed Point Problems

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We introduce and analyze a hybrid iterative algorithm by virtue of Korpelevich's extragradient method, viscosity approximation method, hybrid steepest-descent method, and averaged mapping approach to the gradient-projection algorithm. It is proven that under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of infinitely many nonexpansive mappings, the solution set of finitely many generalized mixed equilibrium problems (GMEPs, the solution set of finitely many variational inequality problems (VIPs, the solution set of general system of variational inequalities (GSVI, and the set of minimizers of convex minimization problem (CMP, which is just a unique solution of a triple hierarchical variational inequality (THVI in a real Hilbert space. In addition, we also consider the application of the proposed algorithm to solve a hierarchical fixed point problem with constraints of finitely many GMEPs, finitely many VIPs, GSVI, and CMP. The results obtained in this paper improve and extend the corresponding results announced by many others.

  2. The Problems of the Defining the Risk: The Case of Mountaineering

    Directory of Open Access Journals (Sweden)

    Viviane Seigneur

    2006-01-01

    Full Text Available A central assumption in sociology is that the view on the risk is essentially a construction rather than a strictly objective perspective. However, this approach has a tendency to forget objective knowledge and tangible facts. Our research on risks in high mountains compares the available information on risks (scientific literature, safety information, media coverage and political discourse with our empiric observations. Our work shows that there are differences caused by lack of fundamental reflection on the definition of the risk as a social construction. We propose to reconsider the definition of the risk with concepts closely connected to risk such as: uncertainty, emotion, phobia and danger, and to point out problems of confusion in several works of authors (e.g. those dealing with sensational activity, such as bungee jumping, as if it was dangerous. URN: urn:nbn:de:0114-fqs0601148

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

    CERN Document Server

    Fuchs, Martin

    2000-01-01

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

  4. On problems in defining abstract and metaphysical concepts--emergence of a new model.

    Science.gov (United States)

    Nahod, Bruno; Nahod, Perina Vukša

    2014-12-01

    Basic anthropological terminology is the first project covering terms from the domain of the social sciences under the Croatian Special Field Terminology program (Struna). Problems that have been sporadically noticed or whose existence could have been presumed during the processing of terms mainly from technical fields and sciences have finally emerged in "anthropology". The principles of the General Theory of Terminology (GTT), which are followed in Struna, were put to a truly exacting test, and sometimes stretched beyond their limits when applied to concepts that do not necessarily have references in the physical world; namely, abstract and metaphysical concepts. We are currently developing a new terminographical model based on Idealized Cognitive Models (ICM), which will hopefully ensure a better cross-filed implementation of various types of concepts and their relations. The goal of this paper is to introduce the theoretical bases of our model. Additionally, we will present a pilot study of the series of experiments in which we are trying to investigate the nature of conceptual categorization in special languages and its proposed difference form categorization in general language.

  5. 30th International School of Mathematics "G Stampacchia" : Equilibrium Problems and Variational Models "Ettore Majorana"

    CERN Document Server

    Giannessi, Franco; Maugeri, Antonino; Equilibrium Problems and Variational Models

    2000-01-01

    The volume, devoted to variational analysis and its applications, collects selected and refereed contributions, which provide an outline of the field. The meeting of the title "Equilibrium Problems and Variational Models", which was held in Erice (Sicily) in the period June 23 - July 2 2000, was the occasion of the presentation of some of these papers; other results are a consequence of a fruitful and constructive atmosphere created during the meeting. New results, which enlarge the field of application of variational analysis, are presented in the book; they deal with the vectorial analysis, time dependent variational analysis, exact penalization, high order deriva­ tives, geometric aspects, distance functions and log-quadratic proximal methodology. The new theoretical results allow one to improve in a remarkable way the study of significant problems arising from the applied sciences, as continuum model of transportation, unilateral problems, multicriteria spatial price models, network equilibrium...

  6. Analysis of Diffusion Problems using Homotopy Perturbation and Variational Iteration Methods

    DEFF Research Database (Denmark)

    Barari, Amin; Poor, A. Tahmasebi; Jorjani, A.

    2010-01-01

    In this paper, variational iteration method and homotopy perturbation method are applied to different forms of diffusion equation. The diffusion equations have found wide applications in heat transfer problems, theory of consolidation and many other problems in engineering. The methods proposed...

  7. A variation method in the optimization problem of the minority game model

    International Nuclear Information System (INIS)

    Blazhyijevs'kij, L.; Yanyishevs'kij, V.

    2009-01-01

    This article contains the results of applying a variation method in the investigation of the optimization problem in the minority game model. That suggested approach is shown to give relevant results about phase transition in the model. Other methods pertinent to the problem have also been assessed.

  8. Minimizers of a Class of Constrained Vectorial Variational Problems: Part I

    KAUST Repository

    Hajaiej, Hichem

    2014-04-18

    In this paper, we prove the existence of minimizers of a class of multiconstrained variational problems. We consider systems involving a nonlinearity that does not satisfy compactness, monotonicity, neither symmetry properties. Our approach hinges on the concentration-compactness approach. In the second part, we will treat orthogonal constrained problems for another class of integrands using density matrices method. © 2014 Springer Basel.

  9. Variation in diagnosis and management of common foot problems by GPs

    NARCIS (Netherlands)

    Gorter, K; de Melker, R; Kuyvenhoven, M; de Poel, S.

    2001-01-01

    Background. There are indications that the diagnosis and management of common foot problems vary widely in general practice. Objectives. Our aim was to explore the variation of GPs' diagnosis and management of common foot problems and the possible correlation between GPs' characteristics and their

  10. The use of Adomian decomposition method for solving problems in calculus of variations

    Directory of Open Access Journals (Sweden)

    Mehdi Dehghan

    2006-01-01

    Full Text Available In this paper, a numerical method is presented for finding the solution of some variational problems. The main objective is to find the solution of an ordinary differential equation which arises from the variational problem. This work is done using Adomian decomposition method which is a powerful tool for solving large amount of problems. In this approach, the solution is found in the form of a convergent power series with easily computed components. To show the efficiency of the method, numerical results are presented.

  11. Uniqueness theorems for variational problems by the method of transformation groups

    CERN Document Server

    Reichel, Wolfgang

    2004-01-01

    A classical problem in the calculus of variations is the investigation of critical points of functionals {\\cal L} on normed spaces V. The present work addresses the question: Under what conditions on the functional {\\cal L} and the underlying space V does {\\cal L} have at most one critical point? A sufficient condition for uniqueness is given: the presence of a "variational sub-symmetry", i.e., a one-parameter group G of transformations of V, which strictly reduces the values of {\\cal L}. The "method of transformation groups" is applied to second-order elliptic boundary value problems on Riemannian manifolds. Further applications include problems of geometric analysis and elasticity.

  12. Stratified Sampling to Define Levels of Petrographic Variation in Coal Beds: Examples from Indonesia and New Zealand

    Directory of Open Access Journals (Sweden)

    Tim A. Moore

    2016-01-01

    Full Text Available DOI: 10.17014/ijog.3.1.29-51Stratified sampling of coal seams for petrographic analysis using block samples is a viable alternative to standard methods of channel sampling and particulate pellet mounts. Although petrographic analysis of particulate pellets is employed widely, it is both time consuming and does not allow variation within sampling units to be assessed - an important measure in any study whether it be for paleoenvironmental reconstruction or in obtaining estimates of industrial attributes. Also, samples taken as intact blocks provide additional information, such as texture and botanical affinity that cannot be gained using particulate pellets. Stratified sampling can be employed both on ‘fine’ and ‘coarse’ grained coal units. Fine-grained coals are defined as those coal intervals that do not contain vitrain bands greater than approximately 1 mm in thickness (as measured perpendicular to bedding. In fine-grained coal seams, a reasonable sized block sample (with a polished surface area of ~3 cm2 can be taken that encapsulates the macroscopic variability. However, for coarse-grained coals (vitrain bands >1 mm a different system has to be employed in order to accurately account for the larger particles. Macroscopic point counting of vitrain bands can accurately account for those particles>1 mm within a coal interval. This point counting method is conducted using something as simple as string on a coal face with marked intervals greater than the largest particle expected to be encountered (although new technologies are being developed to capture this type of information digitally. Comparative analyses of particulate pellets and blocks on the same interval show less than 6% variation between the two sample types when blocks are recalculated to include macroscopic counts of vitrain. Therefore even in coarse-grained coals, stratified sampling can be used effectively and representatively.

  13. Variational methods for eigenvalue problems an introduction to the weinstein method of intermediate problems

    CERN Document Server

    Gould, S H

    1966-01-01

    The first edition of this book gave a systematic exposition of the Weinstein method of calculating lower bounds of eigenvalues by means of intermediate problems. This second edition presents new developments in the framework of the material contained in the first edition, which is retained in somewhat modified form.

  14. Variations Method to Solve Terminal Problems for the Second Order Systems of Canonical Form with State Constraints

    Directory of Open Access Journals (Sweden)

    T. S. Kasatkina

    2015-01-01

    Full Text Available Terminal control problem with fixed finite time for the second order affine systems with state constraints is considered. A solution of such terminal problem is suggested for the systems with scalar control of regular canonical form.In this article it is shown that the initial terminal problem is equivalent to the problem of auxiliary function search. This function should satisfy some conditions. Such function design consists of two stages. The first stage includes search of function which corresponds the solution of the terminal control problem without state constraints. This function is designed as polynom of the fifth power which depends on time variable. Coefficients of the polynom are defined by boundary conditions. The second stage includes modification of designed function if corresponding to that function trajectory is not satisfied constraints. Modification process is realized by adding to the current function supplementary polynom. Influence of that polynom handles by variation of a parameter value. Modification process can include a few iterations. After process termination continuous control is found. This control is the solution of the initial terminal prUsing presented scheme the terminal control problem for system, which describes oscillations of the mathematical pendulum, is solved. This approach can be used for the solution of terminal control problems with state constraints for affine systems with multi-dimensional control.

  15. Hamiltonian and Lagrangian flows on center manifolds with applications to elliptic variational problems

    CERN Document Server

    Mielke, Alexander

    1991-01-01

    The theory of center manifold reduction is studied in this monograph in the context of (infinite-dimensional) Hamil- tonian and Lagrangian systems. The aim is to establish a "natural reduction method" for Lagrangian systems to their center manifolds. Nonautonomous problems are considered as well assystems invariant under the action of a Lie group ( including the case of relative equilibria). The theory is applied to elliptic variational problemson cylindrical domains. As a result, all bounded solutions bifurcating from a trivial state can be described by a reduced finite-dimensional variational problem of Lagrangian type. This provides a rigorous justification of rod theory from fully nonlinear three-dimensional elasticity. The book will be of interest to researchers working in classical mechanics, dynamical systems, elliptic variational problems, and continuum mechanics. It begins with the elements of Hamiltonian theory and center manifold reduction in order to make the methods accessible to non-specialists,...

  16. Age-related changes in strategic variations during arithmetic problem solving: The role of executive control.

    Science.gov (United States)

    Hinault, T; Lemaire, P

    2016-01-01

    In this review, we provide an overview of how age-related changes in executive control influence aging effects in arithmetic processing. More specifically, we consider the role of executive control in strategic variations with age during arithmetic problem solving. Previous studies found that age-related differences in arithmetic performance are associated with strategic variations. That is, when they accomplish arithmetic problem-solving tasks, older adults use fewer strategies than young adults, use strategies in different proportions, and select and execute strategies less efficiently. Here, we review recent evidence, suggesting that age-related changes in inhibition, cognitive flexibility, and working memory processes underlie age-related changes in strategic variations during arithmetic problem solving. We discuss both behavioral and neural mechanisms underlying age-related changes in these executive control processes. © 2016 Elsevier B.V. All rights reserved.

  17. Duality for Multitime Multiobjective Ratio Variational Problems on First Order Jet Bundle

    Directory of Open Access Journals (Sweden)

    Mihai Postolache

    2012-01-01

    Full Text Available We consider a new class of multitime multiobjective variational problems of minimizing a vector of quotients of functionals of curvilinear integral type. Based on the efficiency conditions for multitime multiobjective ratio variational problems, we introduce a ratio dual of generalized Mond-Weir-Zalmai type, and under some assumptions of generalized convexity, duality theorems are stated. We prove our weak duality theorem for efficient solutions, showing that the value of the objective function of the primal cannot exceed the value of the dual. Direct and converse duality theorems are stated, underlying the connections between the values of the objective functions of the primal and dual programs. As special cases, duality results of Mond-Weir-Zalmai type for a multitime multiobjective variational problem are obtained. This work further develops our studies in (Pitea and Postolache (2011.

  18. A Duality Theory for Non-convex Problems in the Calculus of Variations

    Science.gov (United States)

    Bouchitté, Guy; Fragalà, Ilaria

    2018-02-01

    We present a new duality theory for non-convex variational problems, under possibly mixed Dirichlet and Neumann boundary conditions. The dual problem reads nicely as a linear programming problem, and our main result states that there is no duality gap. Further, we provide necessary and sufficient optimality conditions, and we show that our duality principle can be reformulated as a min-max result which is quite useful for numerical implementations. As an example, we illustrate the application of our method to a celebrated free boundary problem. The results were announced in Bouchitté and Fragalà (C R Math Acad Sci Paris 353(4):375-379, 2015).

  19. Presymplectic current and the inverse problem of the calculus of variations

    Science.gov (United States)

    Khavkine, Igor

    2013-11-01

    The inverse problem of the calculus of variations asks whether a given system of partial differential equations (PDEs) admits a variational formulation. We show that the existence of a presymplectic form in the variational bicomplex, when horizontally closed on solutions, allows us to construct a variational formulation for a subsystem of the given PDE. No constraints on the differential order or number of dependent or independent variables are assumed. The proof follows a recent observation of Bridges, Hydon, and Lawson [Math. Proc. Cambridge Philos. Soc. 148(01), 159-178 (2010)] and generalizes an older result of Henneaux [Ann. Phys. 140(1), 45-64 (1982)] from ordinary differential equations (ODEs) to PDEs. Uniqueness of the variational formulation is also discussed.

  20. Presymplectic current and the inverse problem of the calculus of variations

    Energy Technology Data Exchange (ETDEWEB)

    Khavkine, Igor, E-mail: i.khavkine@uu.nl [Institute for Theoretical Physics, Utrecht, Leuvenlaan 4, NL-3584 CE Utrecht (Netherlands)

    2013-11-15

    The inverse problem of the calculus of variations asks whether a given system of partial differential equations (PDEs) admits a variational formulation. We show that the existence of a presymplectic form in the variational bicomplex, when horizontally closed on solutions, allows us to construct a variational formulation for a subsystem of the given PDE. No constraints on the differential order or number of dependent or independent variables are assumed. The proof follows a recent observation of Bridges, Hydon, and Lawson [Math. Proc. Cambridge Philos. Soc. 148(01), 159–178 (2010)] and generalizes an older result of Henneaux [Ann. Phys. 140(1), 45–64 (1982)] from ordinary differential equations (ODEs) to PDEs. Uniqueness of the variational formulation is also discussed.

  1. Variational Homotopy Perturbation Method for Solving Higher Dimensional Initial Boundary Value Problems

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2008-01-01

    Full Text Available We suggest and analyze a technique by combining the variational iteration method and the homotopy perturbation method. This method is called the variational homotopy perturbation method (VHPM. We use this method for solving higher dimensional initial boundary value problems with variable coefficients. The developed algorithm is quite efficient and is practically well suited for use in these problems. The proposed scheme finds the solution without any discritization, transformation, or restrictive assumptions and avoids the round-off errors. Several examples are given to check the reliability and efficiency of the proposed technique.

  2. On an Optimal -Control Problem in Coefficients for Linear Elliptic Variational Inequality

    Directory of Open Access Journals (Sweden)

    Olha P. Kupenko

    2013-01-01

    Full Text Available We consider optimal control problems for linear degenerate elliptic variational inequalities with homogeneous Dirichlet boundary conditions. We take the matrix-valued coefficients in the main part of the elliptic operator as controls in . Since the eigenvalues of such matrices may vanish and be unbounded in , it leads to the “noncoercivity trouble.” Using the concept of convergence in variable spaces and following the direct method in the calculus of variations, we establish the solvability of the optimal control problem in the class of the so-called -admissible solutions.

  3. Laplace transform homotopy perturbation method for the approximation of variational problems.

    Science.gov (United States)

    Filobello-Nino, U; Vazquez-Leal, H; Rashidi, M M; Sedighi, H M; Perez-Sesma, A; Sandoval-Hernandez, M; Sarmiento-Reyes, A; Contreras-Hernandez, A D; Pereyra-Diaz, D; Hoyos-Reyes, C; Jimenez-Fernandez, V M; Huerta-Chua, J; Castro-Gonzalez, F; Laguna-Camacho, J R

    2016-01-01

    This article proposes the application of Laplace Transform-Homotopy Perturbation Method and some of its modifications in order to find analytical approximate solutions for the linear and nonlinear differential equations which arise from some variational problems. As case study we will solve four ordinary differential equations, and we will show that the proposed solutions have good accuracy, even we will obtain an exact solution. In the sequel, we will see that the square residual error for the approximate solutions, belongs to the interval [0.001918936920, 0.06334882582], which confirms the accuracy of the proposed methods, taking into account the complexity and difficulty of variational problems.

  4. Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome.

    Science.gov (United States)

    Collins, Ryan L; Brand, Harrison; Redin, Claire E; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon-Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A; Lucente, Diane; Levy, Brynn; Sanders, Stephan J; Wapner, Ronald J; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E

    2017-03-06

    Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. We sequenced 689 participants with autism spectrum disorder (ASD) and other developmental abnormalities to construct a genome-wide map of large SV. Using long-insert jumping libraries at 105X mean physical coverage and linked-read whole-genome sequencing from 10X Genomics, we document seven major SV classes at ~5 kb SV resolution. Our results encompass 11,735 distinct large SV sites, 38.1% of which are novel and 16.8% of which are balanced or complex. We characterize 16 recurrent subclasses of complex SV (cxSV), revealing that: (1) cxSV are larger and rarer than canonical SV; (2) each genome harbors 14 large cxSV on average; (3) 84.4% of large cxSVs involve inversion; and (4) most large cxSV (93.8%) have not been delineated in previous studies. Rare SVs are more likely to disrupt coding and regulatory non-coding loci, particularly when truncating constrained and disease-associated genes. We also identify multiple cases of catastrophic chromosomal rearrangements known as chromoanagenesis, including somatic chromoanasynthesis, and extreme balanced germline chromothripsis events involving up to 65 breakpoints and 60.6 Mb across four chromosomes, further defining rare categories of extreme cxSV. These data provide a foundational map of large SV in the morbid human genome and demonstrate a previously underappreciated abundance and diversity of cxSV that should be considered in genomic studies of human disease.

  5. A new differential calculus on a complex banach space with application to variational problems of quantum theory

    International Nuclear Information System (INIS)

    Sharma, C.S.; Rebelo, I.

    1975-01-01

    It is proved that a semilinear function on a complex banach space is not differentiable according to the usual definition of differentiability in the calculus on banch spaces. It is shown that this result makes the calculus largely inapplicable to the solution od variational problems of quantum mechanics. A new concept of differentiability called semidifferentiability is defined. This generalizes the standard concept of differentiability in a banach space and the resulting calculus is particularly suitable for optimizing real-value functions on a complex banach space and is directly applicable to the solution of quantum mechanical variational problems. As an example of such application a rigorous proof of a generalized version of a result due to Sharma (J. Phys. A; 2:413 (1969)) is given. In the course of this work a new concept of prelinearity is defined and some standard results in the calculus in banach spaces are extended and generalized into more powerful ones applicable directly to prelinear functions and hence yielding the standard results for linear function as particular cases. (author)

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

    Directory of Open Access Journals (Sweden)

    Cho Yeol

    2011-01-01

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

  7. Variational approach to direct and inverse problems of atmospheric pollution studies

    Science.gov (United States)

    Penenko, Vladimir; Tsvetova, Elena; Penenko, Alexey

    2016-04-01

    We present the development of a variational approach for solving interrelated problems of atmospheric hydrodynamics and chemistry concerning air pollution transport and transformations. The proposed approach allows us to carry out complex studies of different-scale physical and chemical processes using the methods of direct and inverse modeling [1-3]. We formulate the problems of risk/vulnerability and uncertainty assessment, sensitivity studies, variational data assimilation procedures [4], etc. A computational technology of constructing consistent mathematical models and methods of their numerical implementation is based on the variational principle in the weak constraint formulation specifically designed to account for uncertainties in models and observations. Algorithms for direct and inverse modeling are designed with the use of global and local adjoint problems. Implementing the idea of adjoint integrating factors provides unconditionally monotone and stable discrete-analytic approximations for convection-diffusion-reaction problems [5,6]. The general framework is applied to the direct and inverse problems for the models of transport and transformation of pollutants in Siberian and Arctic regions. The work has been partially supported by the RFBR grant 14-01-00125 and RAS Presidium Program I.33P. References: 1. V. Penenko, A.Baklanov, E. Tsvetova and A. Mahura . Direct and inverse problems in a variational concept of environmental modeling //Pure and Applied Geoph.(2012) v.169: 447-465. 2. V. V. Penenko, E. A. Tsvetova, and A. V. Penenko Development of variational approach for direct and inverse problems of atmospheric hydrodynamics and chemistry, Izvestiya, Atmospheric and Oceanic Physics, 2015, Vol. 51, No. 3, p. 311-319, DOI: 10.1134/S0001433815030093. 3. V.V. Penenko, E.A. Tsvetova, A.V. Penenko. Methods based on the joint use of models and observational data in the framework of variational approach to forecasting weather and atmospheric composition

  8. Application of the variational iteration method for system of initial value problems delay differential equations

    Science.gov (United States)

    Yousef, Hamood. M.; Ismail, A. I. B. MD.

    2017-08-01

    Many attempts have been presented to solve the system of Delay Differential Equations (DDE) with Initial Value Problem. As a result, it has shown difficulties when getting the solution or cannot be solved. In this paper, a Variational Iteration Method is employed to find out an approximate solution for the system of DDE with initial value problems. The example illustrates convenient and an efficiency comparison with the exact solution.

  9. On the inverse problem of the calculus of variations in field theory

    International Nuclear Information System (INIS)

    Henneaux, M.

    1984-01-01

    The inverse problem of the calculus of variations is investigated in the case of field theory. Uniqueness of the action principle is demonstrated for the vector Laplace equation in a non-decomposable Riemannian space, as well as for the harmonic map equation. (author)

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

    Science.gov (United States)

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

    2017-07-01

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

  11. Aksoy Nigar Yildirim Variational problem with complex co-efficient of ...

    Indian Academy of Sciences (India)

    user1

    Abbaspour Mohammad Hassan see Ghaffarzadeh Ghodrat. 329. Abhyankar Shreeram S. Rees valuations. 525. Agarwal A K. seeAnand S. 23. Aithal A R. On the extrema of Dirichlet's first eigen- value of a family of punctured regular polygons in two dimensional space forms. 257. Aksoy Nigar Yildirim. Variational problem ...

  12. Schwinger variational principle in scattering problems of charged particles on mesic atoms and atoms

    International Nuclear Information System (INIS)

    Belyaev, V.B.; Zubarev, A.L.; Podkopaev, A.P.

    1978-01-01

    The Schwinger variational principle is applied to solve the problems of atomic physics. A separable approximation for a Hamiltonian of a bound subsystem is used. The length of e + H-scattering and the elastic p(dμ)-scattering cross section are calculated in the second Born approximation

  13. Variational Iteration Method for Fifth-Order Boundary Value Problems Using He's Polynomials

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2008-01-01

    Full Text Available We apply the variational iteration method using He's polynomials (VIMHP for solving the fifth-order boundary value problems. The proposed method is an elegant combination of variational iteration and the homotopy perturbation methods and is mainly due to Ghorbani (2007. The suggested algorithm is quite efficient and is practically well suited for use in these problems. The proposed iterative scheme finds the solution without any discritization, linearization, or restrictive assumptions. Several examples are given to verify the reliability and efficiency of the method. The fact that the proposed technique solves nonlinear problems without using Adomian's polynomials can be considered as a clear advantage of this algorithm over the decomposition method.

  14. On the uniqueness of minimizers for a class of variational problems with Polyconvex integrand

    KAUST Repository

    Awi, Romeo

    2017-02-05

    We prove existence and uniqueness of minimizers for a family of energy functionals that arises in Elasticity and involves polyconvex integrands over a certain subset of displacement maps. This work extends previous results by Awi and Gangbo to a larger class of integrands. First, we study these variational problems over displacements for which the determinant is positive. Second, we consider a limit case in which the functionals are degenerate. In that case, the set of admissible displacements reduces to that of incompressible displacements which are measure preserving maps. Finally, we establish that the minimizer over the set of incompressible maps may be obtained as a limit of minimizers corresponding to a sequence of minimization problems over general displacements provided we have enough regularity on the dual problems. We point out that these results defy the direct methods of the calculus of variations.

  15. An algorithm for finding a common solution for a system of mixed equilibrium problem, quasi-variational inclusion problem and fixed point problem of nonexpansive semigroup

    Directory of Open Access Journals (Sweden)

    Liu Min

    2010-01-01

    Full Text Available In this paper, we introduce a hybrid iterative scheme for finding a common element of the set of solutions for a system of mixed equilibrium problems, the set of common fixed points for a nonexpansive semigroup and the set of solutions of the quasi-variational inclusion problem with multi-valued maximal monotone mappings and inverse-strongly monotone mappings in a Hilbert space. Under suitable conditions, some strong convergence theorems are proved. Our results extend some recent results in the literature.

  16. Variational Inequalities in Hilbert Spaces with Measures and Optimal Stopping Problems

    International Nuclear Information System (INIS)

    Barbu, Viorel; Marinelli, Carlo

    2008-01-01

    We study the existence theory for parabolic variational inequalities in weighted L 2 spaces with respect to excessive measures associated with a transition semigroup. We characterize the value function of optimal stopping problems for finite and infinite dimensional diffusions as a generalized solution of such a variational inequality. The weighted L 2 setting allows us to cover some singular cases, such as optimal stopping for stochastic equations with degenerate diffusion coefficient. As an application of the theory, we consider the pricing of American-style contingent claims. Among others, we treat the cases of assets with stochastic volatility and with path-dependent payoffs

  17. Optimality Bounds for a Variational Relaxation of the Image Partitioning Problem

    KAUST Repository

    Lellmann, Jan

    2012-11-09

    We consider a variational convex relaxation of a class of optimal partitioning and multiclass labeling problems, which has recently proven quite successful and can be seen as a continuous analogue of Linear Programming (LP) relaxation methods for finite-dimensional problems. While for the latter several optimality bounds are known, to our knowledge no such bounds exist in the infinite-dimensional setting. We provide such a bound by analyzing a probabilistic rounding method, showing that it is possible to obtain an integral solution of the original partitioning problem from a solution of the relaxed problem with an a priori upper bound on the objective. The approach has a natural interpretation as an approximate, multiclass variant of the celebrated coarea formula. © 2012 Springer Science+Business Media New York.

  18. Off-energy-shell variations of two-nucleon transition matrix and three-nucleon problem

    International Nuclear Information System (INIS)

    Stingl, M.; Sauer, P.U.

    1975-01-01

    For a schematic three-nucleon problem, approximate analytic expressions are derived for the functional derivatives of measurable three-particle quantities with respect to off-shell variations of the triplet-s two-nucleon transition matrix. Those quantities include neutron-deuteron scattering lengths, trinucleon binding energies, and the 3 He charge form-factor minimum; correlations between off-shell changes in the latter two are discussed. An indication is given how results of this kind may be to decide whether or not a given set of discrepancies between calculated and experimental three-nucleon observables can be reconciled in terms of off-shell variations of a nonretarded hermitean two-nucleon interaction. The treatment is not restricted to special classes of phase-shift equivalent potentials or phase-shift preserving transformations but instead makes use of a systematic parameterization of off-shell variations in terms of symmetric rational approximants of increasing order

  19. 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

  20. A new operational approach for solving fractional variational problems depending on indefinite integrals

    Science.gov (United States)

    Ezz-Eldien, S. S.; Doha, E. H.; Bhrawy, A. H.; El-Kalaawy, A. A.; Machado, J. A. T.

    2018-04-01

    In this paper, we propose a new accurate and robust numerical technique to approximate the solutions of fractional variational problems (FVPs) depending on indefinite integrals with a type of fixed Riemann-Liouville fractional integral. The proposed technique is based on the shifted Chebyshev polynomials as basis functions for the fractional integral operational matrix (FIOM). Together with the Lagrange multiplier method, these problems are then reduced to a system of algebraic equations, which greatly simplifies the solution process. Numerical examples are carried out to confirm the accuracy, efficiency and applicability of the proposed algorithm

  1. Variational Multiscale error estimator for anisotropic adaptive fluid mechanic simulations: application to convection-diffusion problems

    OpenAIRE

    Bazile , Alban; Hachem , Elie; Larroya-Huguet , Juan-Carlos; Mesri , Youssef

    2018-01-01

    International audience; In this work, we present a new a posteriori error estimator based on the Variational Multiscale method for anisotropic adaptive fluid mechanics problems. The general idea is to combine the large scale error based on the solved part of the solution with the sub-mesh scale error based on the unresolved part of the solution. We compute the latter with two different methods: one using the stabilizing parameters and the other using bubble functions. We propose two different...

  2. A study of the one dimensional total generalised variation regularisation problem

    KAUST Repository

    Papafitsoros, Konstantinos

    2015-03-01

    © 2015 American Institute of Mathematical Sciences. In this paper we study the one dimensional second order total generalised variation regularisation (TGV) problem with L2 data fitting term. We examine the properties of this model and we calculate exact solutions using simple piecewise affine functions as data terms. We investigate how these solutions behave with respect to the TGV parameters and we verify our results using numerical experiments.

  3. Coarse-convex-compactification approach to numerical solution of nonconvex variational problems

    Czech Academy of Sciences Publication Activity Database

    Meziat, R.; Roubíček, Tomáš; Patino, D.

    2010-01-01

    Roč. 31, č. 4 (2010), s. 460-488 ISSN 0163-0563 Grant - others:GA MŠk(CZ) LC06052 Program:LC Institutional research plan: CEZ:AV0Z20760514 Keywords : convex approximations * method of moments * relaxed variational problems Subject RIV: BA - General Mathematics Impact factor: 0.687, year: 2010 http://www.informaworld.com/smpp/content~db=all~content=a922886514~frm=titlelink

  4. A study of the one dimensional total generalised variation regularisation problem

    KAUST Repository

    Papafitsoros, Konstantinos; Bredies, Kristian

    2015-01-01

    © 2015 American Institute of Mathematical Sciences. In this paper we study the one dimensional second order total generalised variation regularisation (TGV) problem with L2 data fitting term. We examine the properties of this model and we calculate exact solutions using simple piecewise affine functions as data terms. We investigate how these solutions behave with respect to the TGV parameters and we verify our results using numerical experiments.

  5. The vexing problem of defining the meaning, role and measurement of values in treatment decision-making.

    Science.gov (United States)

    Charles, Cathy; Gafni, Amiram

    2014-03-01

    Two international movements, evidence-based medicine (EBM) and shared decision-making (SDM) have grappled for some time with issues related to defining the meaning, role and measurement of values/preferences in their respective models of treatment decision-making. In this article, we identify and describe unresolved problems in the way that each movement addresses these issues. The starting point for this discussion is that at least two essential ingredients are needed for treatment decision-making: research information about treatment options and their potential benefits and risks; and the values/preferences of participants in the decision-making process. Both the EBM and SDM movements have encountered difficulties in defining the meaning, role and measurement of values/preferences in treatment decision-making. In the EBM model of practice, there is no clear and consistent definition of patient values/preferences and no guidance is provided on how to integrate these into an EBM model of practice. Methods advocated to measure patient values are also problematic. Within the SDM movement, patient values/preferences tend to be defined and measured in a restrictive and reductionist way as patient preferences for treatment options or attributes of options, while broader underlying value structures are ignored. In both models of practice, the meaning and expected role of physician values in decision-making are unclear. Values clarification exercises embedded in patient decision aids are suggested by SDM advocates to identify and communicate patient values/preferences for different treatment outcomes. Such exercises have the potential to impose a particular decision-making theory and/or process onto patients, which can change the way they think about and process information, potentially impeding them from making decisions that are consistent with their true values. The tasks of clarifying the meaning, role and measurement of values/preferences in treatment decision

  6. Variational methods for direct/inverse problems of atmospheric dynamics and chemistry

    Science.gov (United States)

    Penenko, Vladimir; Penenko, Alexey; Tsvetova, Elena

    2013-04-01

    We present a variational approach for solving direct and inverse problems of atmospheric hydrodynamics and chemistry. It is important that the accurate matching of numerical schemes has to be provided in the chain of objects: direct/adjoint problems - sensitivity relations - inverse problems, including assimilation of all available measurement data. To solve the problems we have developed a new enhanced set of cost-effective algorithms. The matched description of the multi-scale processes is provided by a specific choice of the variational principle functionals for the whole set of integrated models. Then all functionals of variational principle are approximated in space and time by splitting and decomposition methods. Such approach allows us to separately consider, for example, the space-time problems of atmospheric chemistry in the frames of decomposition schemes for the integral identity sum analogs of the variational principle at each time step and in each of 3D finite-volumes. To enhance the realization efficiency, the set of chemical reactions is divided on the subsets related to the operators of production and destruction. Then the idea of the Euler's integrating factors is applied in the frames of the local adjoint problem technique [1]-[3]. The analytical solutions of such adjoint problems play the role of integrating factors for differential equations describing atmospheric chemistry. With their help, the system of differential equations is transformed to the equivalent system of integral equations. As a result we avoid the construction and inversion of preconditioning operators containing the Jacobi matrixes which arise in traditional implicit schemes for ODE solution. This is the main advantage of our schemes. At the same time step but on the different stages of the "global" splitting scheme, the system of atmospheric dynamic equations is solved. For convection - diffusion equations for all state functions in the integrated models we have developed the

  7. The problem of defining the limits of protected areas in Ukraine regarding to the sustainable land management

    Directory of Open Access Journals (Sweden)

    Б. В. Даниленко

    2015-11-01

    Full Text Available Nowadays all over the world new protected areas are being created. In Ukraine this process is developed within European programs. During the years of independence many new protected areas were created. Large amount of them were included in so called Ukrainian ecological network that ought to be built in 2015. This network is connected with the European ecological network. The governmental reports show high level of the execution of the programs of developing of the protected areas. But in reality we can see that many of new protected areas do not have the determined limits. This results in dangerous human occupation of such lands. Businessmen understand that occupation will be impossible soon. And they think that such protected areas are proclaimed but yet not really exist. And most of Ukrainian courts agree with this. Recent research and publications analyses. Research of management of protected areas through legal means in Ukraine was made by many Ukrainian scientists (V.I. Andreytsev, A.P. Hetman, M.V. Shulga, P.F. Kulynich, A.M. Myroshnychenko and others. At the same time the scientists have not paid enough attention to the problem of defining the limits of protected areas which is now really a great legal problem in Ukraine. Paper objective is the legal problem of defining the limits of protected areas in Ukraine regarding to the sustainable land management. Paper main body. Generally, protected areas are understood to be those in which human occupation or at least the exploitation of resources is limited. The definition that has been widely accepted across regional and global frameworks has been provided by the International Union for Conservation of Nature (IUCN in its categorization guidelines for protected areas. The definition is as follows: "A clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services

  8. Retrospectively reported month-to-month variation in sleeping problems of people naturally exposed to high-amplitude annual variation in daylength and/or temperature

    Directory of Open Access Journals (Sweden)

    Arcady A. Putilov

    Full Text Available Compared to literature on seasonal variation in mood and well-being, reports on seasonality of trouble sleeping are scarce and contradictive. To extend geography of such reports on example of people naturally exposed to high-amplitude annual variation in daylength and/or temperature. Participants were the residents of Turkmenia, West Siberia, South and North Yakutia, Chukotka, and Alaska. Health and sleep-wake adaptabilities, month-to-month variation in sleeping problems, well-being and behaviors were self-assessed. More than a half of 2398 respondents acknowledged seasonality of sleeping problems. Four of the assessed sleeping problems demonstrated three different patterns of seasonal variation. Rate of the problems significantly increased in winter months with long nights and cold days (daytime sleepiness and difficulties falling and staying asleep as well as in summer months with either long days (premature awakening and difficulties falling and staying asleep or hot nights and days (all 4 sleeping problems. Individual differences between respondents in pattern and level of seasonality of sleeping problems were significantly associated with differences in several other domains of individual variation, such as gender, age, ethnicity, physical health, morning-evening preference, sleep quality, and adaptability of the sleep-wake cycle. These results have practical relevance to understanding of the roles playing by natural environmental factors in seasonality of sleeping problems as well as to research on prevalence of sleep disorders and methods of their prevention and treatment in regions with large seasonal differences in temperature and daylength.

  9. Schwinger variational principle in the nuclear two-body problem and multichannel theory

    International Nuclear Information System (INIS)

    Zubarev, A.L.; Podkopaev, A.P.

    1978-01-01

    The aim of the investigation is to study the Schwinger variational principle in the nuclear two-body problem and the multichannel theory. An approach is proposed to problems of the potential scattering based on the substitution of the exact potential operator V by the finite rank operator Vsup((n)) with which the dynamic equations are solved exactly. The functionals obtained for observed values coincide with corresponding expressions derived by the Schwinger variational principle with the set of test functions. The determination of the Schwinger variational principle is given. The method is given for finding amplitude of the double-particle scattering with the potential Vsup((n)). The corresponding amplitudes are constructed within the framework of the multichannel potential model. Interpolation formula for determining amplitude, which describes with high accuracy a process of elastic scattering for any energies, is obtained. On the basis of the above method high-energy amplitude may be obtained within the range of small and large scattering angles

  10. The Schwinger variational principle in the quantum-mechanical three-body problem

    International Nuclear Information System (INIS)

    Podkopaev, A.P.; Subarev, A.I.; Wrzecionko, J.

    1978-01-01

    The Schwinger variational principle (SVP) is applied to problems of atomic (e + H scattering), mesoatomic (p(dμ) scattering) and nuclear (pion-deuteron scattering) physics. The convergence of the Schwinger variational iterative method is investigated. It is shown that in some cases there occurs a pathological convergence. It means that the iterative procedure is convergent, but not to the exact solution. The method of strong coupling of channels is reformulated on the basis of SVP. it permits the summation over all closed channels. The obtained equations are applied to the calculations of the low energy scattering parameters of the following processes: e + H → e + H; πd → πd. The dependence on πN scattering lengths and effective radii is investigated. It is shown that the contribution of closed channels to the π - d scattering length is 30 percent

  11. THE MODEL OF IDENTIFICATION OF THE PROBLEM MAIN CAUSE SET OF VARIATION

    Directory of Open Access Journals (Sweden)

    Nenad Miric

    2008-06-01

    Full Text Available The term Lean has been widely used in today's product manufacturing and service delivery environments. In its fundamental nature the Lean Philosophy continuously strives for elimination of any kind of waste that exists in such environments. There are six basic strategies [1] related to the Lean Philosophy: Workplace Safety & Order & Cleanliness, JIT production, Six Sigma Quality, Empowered Teams, Visual Management and Pursuit of Perfection. On the journey of sustaining the lean supporting strategies there are many problems, or opportunities as Lean Practitioners call them. The value of some strategies highly depends on the efficiency of the problem solving techniques used to overcome the emerging issues. JIT production is difficult to imagine without a system that supports a high level of operational readiness with equipment uptime above 98%. Six Sigma level of quality, even when built into a product or system design, still undergoes the challenges of day to day operations and the variability brought with it. This variability is the source of waste and lean systems culture strives for continuous reduction of it. Empowered Teams properly trained to recognize the real cause of the problems and their Pursuit of Perfection culture are one of the corner stones of Lean Philosophy sustainability. Their ability to work with Problem Solvers and understand the difference between the "cure of the symptoms" approach versus "problem root cause identification" is one of the distinctions between Lean and Mass operations. Among the series of Statistical Engineering To ols this paper will show one of the techniques that proved to be powerful in the identification of the Set of Variation that contains the Main Cause of the new problems that arise in daily operations. This technique is called Multi - Vari. Multi - Vari is th e statistical engineering method used to analyze the set of data acquired in an organized manner. The set could be analyzed graphically or

  12. Comparison of finite-difference and variational solutions to advection-diffusion problems

    International Nuclear Information System (INIS)

    Lee, C.E.; Washington, K.E.

    1984-01-01

    Two numerical solution methods are developed for 1-D time-dependent advection-diffusion problems on infinite and finite domains. Numerical solutions are compared with analytical results for constant coefficients and various boundary conditions. A finite-difference spectrum method is solved exactly in time for periodic boundary conditions by a matrix operator method and exhibits excellent accuracy compared with other methods, especially at late times, where it is also computationally more efficient. Finite-system solutions are determined from a conservational variational principle with cubic spatial trial functions and solved in time by a matrix operator method. Comparisons of problems with few nodes show excellent agreement with analytical solutions and exhibit the necessity of implementing Lagrangian conservational constraints for physically-correct solutions. (author)

  13. Variational data assimilation problem for the thermodynamics model with displaced pole

    Science.gov (United States)

    Parmuzin, Eugene; Agosgkov, Valery; Zakharova, Natalia

    2017-04-01

    The most versatile and promising technology for solving problems of monitoring and analysis of the natural environment is a four-dimensional variational data assimilation of observation data. The development of computational algorithms for the solution of data assimilation problems in geophysical hydrodynamics is important in the contemporary computation and informational science to improve the quality of long-term prediction by using the hydrodynamics sea model. These problems are applied to close and solve in practice the appropriate inverse problems of the geophysical hydrodynamics. In this work the variational data assimilation problems in the Baltic Sea water area with displaced pole were formulated and studied [1]. We assume, that the unique function which is obtained by observation data processing is the function and we permit that the function is known only on a part of considering area (for example, on a part of the Baltic Sea). Numerical experiments on restoring the ocean heat flux and obtaining solution of the system (temperature, salinity, velocity, and sea surface height) in the Baltic Sea primitive equation hydrodynamics model [2] with assimilation procedure were carried out. In the calculations we used daily sea surface temperature observation from Danish meteorological Institute, prepared on the basis of measurements of the radiometer (AVHRR, AATSR and AMSRE) and spectroradiometer (SEVIRI and MODIS). The spatial resolution of the model grid with respect to the horizontal variables is uniform on latitude (0.2 degree) and varies on longitude from 0.04 to 0.0004 degree . The results of the numerical experiments are presented. This study was supported by the Russian Foundation for Basic Research (project №16-01-00548) and project №14-11-00609 by the Russian Science Foundation. References: [1] Agoshkov V.I., Parmuzin E.I., Zakharova N.B., Zalesny V.B., Shutyaev V.P., Gusev A.V. Variational assimilation of observation data in the mathematical model of

  14. Virtual sampling in variational processing of Monte Carlo simulation in a deep neutron penetration problem

    International Nuclear Information System (INIS)

    Allagi, Mabruk O.; Lewins, Jeffery D.

    1999-01-01

    In a further study of virtually processed Monte Carlo estimates in neutron transport, a shielding problem has been studied. The use of virtual sampling to estimate the importance function at a certain point in the phase space depends on the presence of neutrons from the real source at that point. But in deep penetration problems, not many neutrons will reach regions far away from the source. In order to overcome this problem, two suggestions are considered: (1) virtual sampling is used as far as the real neutrons can reach, then fictitious sampling is introduced for the remaining regions, distributed in all the regions, or (2) only one fictitious source is placed where the real neutrons almost terminate and then virtual sampling is used in the same way as for the real source. Variational processing is again found to improve the Monte Carlo estimates, being best when using one fictitious source in the far regions with virtual sampling (option 2). When fictitious sources are used to estimate the importances in regions far away from the source, some optimization has to be performed for the proportion of fictitious to real sources, weighted against accuracy and computational costs. It has been found in this study that the optimum number of cells to be treated by fictitious sampling is problem dependent, but as a rule of thumb, fictitious sampling should be employed in regions where the number of neutrons from the real source fall below a specified limit for good statistics

  15. Total variation regularization for a backward time-fractional diffusion problem

    International Nuclear Information System (INIS)

    Wang, Liyan; Liu, Jijun

    2013-01-01

    Consider a two-dimensional backward problem for a time-fractional diffusion process, which can be considered as image de-blurring where the blurring process is assumed to be slow diffusion. In order to avoid the over-smoothing effect for object image with edges and to construct a fast reconstruction scheme, the total variation regularizing term and the data residual error in the frequency domain are coupled to construct the cost functional. The well posedness of this optimization problem is studied. The minimizer is sought approximately using the iteration process for a series of optimization problems with Bregman distance as a penalty term. This iteration reconstruction scheme is essentially a new regularizing scheme with coupling parameter in the cost functional and the iteration stopping times as two regularizing parameters. We give the choice strategy for the regularizing parameters in terms of the noise level of measurement data, which yields the optimal error estimate on the iterative solution. The series optimization problems are solved by alternative iteration with explicit exact solution and therefore the amount of computation is much weakened. Numerical implementations are given to support our theoretical analysis on the convergence rate and to show the significant reconstruction improvements. (paper)

  16. Efficient computation of the elastography inverse problem by combining variational mesh adaption and a clustering technique

    International Nuclear Information System (INIS)

    Arnold, Alexander; Bruhns, Otto T; Reichling, Stefan; Mosler, Joern

    2010-01-01

    This paper is concerned with an efficient implementation suitable for the elastography inverse problem. More precisely, the novel algorithm allows us to compute the unknown stiffness distribution in soft tissue by means of the measured displacement field by considerably reducing the numerical cost compared to previous approaches. This is realized by combining and further elaborating variational mesh adaption with a clustering technique similar to those known from digital image compression. Within the variational mesh adaption, the underlying finite element discretization is only locally refined if this leads to a considerable improvement of the numerical solution. Additionally, the numerical complexity is reduced by the aforementioned clustering technique, in which the parameters describing the stiffness of the respective soft tissue are sorted according to a predefined number of intervals. By doing so, the number of unknowns associated with the elastography inverse problem can be chosen explicitly. A positive side effect of this method is the reduction of artificial noise in the data (smoothing of the solution). The performance and the rate of convergence of the resulting numerical formulation are critically analyzed by numerical examples.

  17. Strong convergence with a modified iterative projection method for hierarchical fixed point problems and variational inequalities

    Directory of Open Access Journals (Sweden)

    Ibrahim Karahan

    2016-04-01

    Full Text Available Let C be a nonempty closed convex subset of a real Hilbert space H. Let {T_{n}}:C›H be a sequence of nearly nonexpansive mappings such that F:=?_{i=1}^{?}F(T_{i}?Ø. Let V:C›H be a ?-Lipschitzian mapping and F:C›H be a L-Lipschitzian and ?-strongly monotone operator. This paper deals with a modified iterative projection method for approximating a solution of the hierarchical fixed point problem. It is shown that under certain approximate assumptions on the operators and parameters, the modified iterative sequence {x_{n}} converges strongly to x^{*}?F which is also the unique solution of the following variational inequality: ?0, ?x?F. As a special case, this projection method can be used to find the minimum norm solution of above variational inequality; namely, the unique solution x^{*} to the quadratic minimization problem: x^{*}=argmin_{x?F}?x?². The results here improve and extend some recent corresponding results of other authors.

  18. Family stressors, home demands and responsibilities, coping resources, social connectedness, and Thai older adult health problems: examining gender variations.

    Science.gov (United States)

    Krishnakumar, Ambika; Narine, Lutchmie; Soonthorndhada, Amara; Thianlai, Kanchana

    2015-03-01

    To examine gender variations in the linkages among family stressors, home demands and responsibilities, coping resources, social connectedness, and older adult health problems. Data were collected from 3,800 elderly participants (1,654 men and 2,146 women) residing in Kanchanaburi province, Thailand. Findings indicated gender variations in the levels of these constructs and in the mediational pathways. Thai women indicated greater health problems than men. Emotional empathy was the central variable that linked financial strain, home demands and responsibilities, and older adult health problems through social connectedness. Financial strain (and negative life events for women) was associated with lowered coping self-efficacy and increased health problems. The model indicated greater strength in predicting female health problems. Findings support gender variations in the relationships between ecological factors and older adult health problems. © The Author(s) 2014.

  19. Genetic and morphological variation of bee-parasitic Tropilaelaps mites (Acari: Laelapidae): new and re-defined species.

    Science.gov (United States)

    Anderson, Denis L; Morgan, Mathew J

    2007-01-01

    Mites in the genus Tropilaelaps are parasites of social honeybees. Two species, Tropilaelaps clareae and T. koenigerum, have been recorded and their primary hosts are presumed to be the giant honeybees of Asia, Apis dorsata and A. laboriosa. The most common species, T. clareae, is also an economically important pest of the introduced Western honeybee (A. mellifera) throughout Asia and is considered an emerging threat to world apiculture. In the studies reported here, genetic (mtDNA CO-I and nuclear ITS1-5.8S-ITS2 gene sequence) and morphological variation and host associations were examined among Tropilaelaps isolates collected from A. dorsata, A. laboriosa and A. mellifera throughout Asia and neighbouring regions. The results clearly indicate that the genus contains at least four species. Tropilaelaps clareae, previously assumed to be ubiquitous in Asia, was found to be two species, and it is here redefined as encompassing haplotypes (mites with distinct mtDNA gene sequences) that parasitise native A. dorsata breviligula and introduced A. mellifera in the Philippines and also native A. d. binghami on Sulawesi Island in Indonesia. Tropilaelaps mercedesae n. sp., which until now has been mistaken for T. clareae, encompasses haplotypes that, together with haplotypes of T. koenigerum, parasitise native A. d. dorsata in mainland Asia and Indonesia (except Sulawesi Island). It also parasitises introduced A. mellifera in these and surrounding regions and, with another new species, T. thaii n. sp., also parasitises A. laboriosa in mountainous Himalayan regions. Methods are described for identifying each species. These studies help to clarify the emerging threat of Tropilaelaps to world apiculture and will necessitate a revision of quarantine protocols for countries that import and export honeybees.

  20. One particle properties in the 2D Coulomb problem. Luttinger-Ward variational approach

    International Nuclear Information System (INIS)

    Agnihotri, M.P.

    2007-01-01

    In this work, we have studied the 2D Coulomb problem. We used the Luttinger-Ward variational principle to determine the self-energy Σ in ring approximation. The use of an ansatz for Σ enables us to perform the frequency sums (integrals as T → 0) analytically. Compared to the usual procedure of iterating the self consistency equation with free Green's function as starting points, the present approach is superior. It works for higher density parameter r s (low density) where the iteration already fails to converge. The motivation of the present work is the quantum Hall system at filling factor 1/2. The Luttinger-Ward procedure is a rather powerful method in particular if combined with an analytical ansatz for Σ. The computation performed here for 2DEG has to be seen as a first step: There, the experiment shows the features of a free Fermion system that is interpreted as a system of Composite Fermions. If one studies the self energy of the Composite Fermions in an conserved approximation that corresponds to the ring approximation, one encounters a self consistency equation. However, an iterative solution of this equation meets with a complication: Instead of the polarization part Π 00 , in the case of the Composite Fermion there appears the longitudinal polarization part Π LL that has an additional factor (2k + q) 2 under the k integral. This integral converges only after the frequency integral is performed. It is highly difficult to reproduce this numerically. Here, the Luttinger-Ward variational approach applied to the 2D Coulomb problem in the present work looks promising. For the 2D Coulomb problem, in the ring approximation for the LW thermodynamic potential, that already leads to a formidable integral equation that has to be studied numerically. (orig.)

  1. One particle properties in the 2D Coulomb problem. Luttinger-Ward variational approach

    Energy Technology Data Exchange (ETDEWEB)

    Agnihotri, M.P.

    2007-04-27

    In this work, we have studied the 2D Coulomb problem. We used the Luttinger-Ward variational principle to determine the self-energy {sigma} in ring approximation. The use of an ansatz for {sigma} enables us to perform the frequency sums (integrals as T {yields} 0) analytically. Compared to the usual procedure of iterating the self consistency equation with free Green's function as starting points, the present approach is superior. It works for higher density parameter r{sub s} (low density) where the iteration already fails to converge. The motivation of the present work is the quantum Hall system at filling factor 1/2. The Luttinger-Ward procedure is a rather powerful method in particular if combined with an analytical ansatz for {sigma}. The computation performed here for 2DEG has to be seen as a first step: There, the experiment shows the features of a free Fermion system that is interpreted as a system of Composite Fermions. If one studies the self energy of the Composite Fermions in an conserved approximation that corresponds to the ring approximation, one encounters a self consistency equation. However, an iterative solution of this equation meets with a complication: Instead of the polarization part {pi}{sub 00}, in the case of the Composite Fermion there appears the longitudinal polarization part {pi}{sub LL} that has an additional factor (2k + q){sup 2} under the k integral. This integral converges only after the frequency integral is performed. It is highly difficult to reproduce this numerically. Here, the Luttinger-Ward variational approach applied to the 2D Coulomb problem in the present work looks promising. For the 2D Coulomb problem, in the ring approximation for the LW thermodynamic potential, that already leads to a formidable integral equation that has to be studied numerically. (orig.)

  2. He's variational iteration method applied to the solution of the prey and predator problem with variable coefficients

    International Nuclear Information System (INIS)

    Yusufoglu, Elcin; Erbas, Baris

    2008-01-01

    In this Letter, a mathematical model of the problem of prey and predator is presented and He's variational iteration method is employed to compute an approximation to the solution of the system of nonlinear differential equations governing the problem. The results are compared with the results obtained by Adomian decomposition method and homotopy perturbation method. Comparison of the methods show that He's variational iteration method is a powerful method for obtaining approximate solutions to nonlinear equations and their systems

  3. Solving variational problems and partial differential equations that map between manifolds via the closest point method

    Science.gov (United States)

    King, Nathan D.; Ruuth, Steven J.

    2017-05-01

    Maps from a source manifold M to a target manifold N appear in liquid crystals, color image enhancement, texture mapping, brain mapping, and many other areas. A numerical framework to solve variational problems and partial differential equations (PDEs) that map between manifolds is introduced within this paper. Our approach, the closest point method for manifold mapping, reduces the problem of solving a constrained PDE between manifolds M and N to the simpler problems of solving a PDE on M and projecting to the closest points on N. In our approach, an embedding PDE is formulated in the embedding space using closest point representations of M and N. This enables the use of standard Cartesian numerics for general manifolds that are open or closed, with or without orientation, and of any codimension. An algorithm is presented for the important example of harmonic maps and generalized to a broader class of PDEs, which includes p-harmonic maps. Improved efficiency and robustness are observed in convergence studies relative to the level set embedding methods. Harmonic and p-harmonic maps are computed for a variety of numerical examples. In these examples, we denoise texture maps, diffuse random maps between general manifolds, and enhance color images.

  4. A moving boundary problem for the Stokes equations involving osmosis : Variational modelling and short-time well-posedness

    NARCIS (Netherlands)

    Lippoth, F.; Peletier, M.A.; Prokert, G.

    2016-01-01

    Within the framework of variational modelling we derive a one-phase moving boundary problem describing the motion of a semipermeable membrane enclosing a viscous liquid, driven by osmotic pressure and surface tension of the membrane. For this problem we prove the existence of classical solutions for

  5. Have I Ever Done Anything Like This Before? Older Adults Solving Ill-Defined Problems in Intensive Volunteering.

    Science.gov (United States)

    Cheek, Cheryl; Piercy, Kathleen W; Kohlenberg, Meranda

    2015-01-01

    This study examined the ways in which individuals over 50 years old solved problems while volunteering in intensive humanitarian and disaster relief service. Thirty-seven men and women in the sample were sponsored by three religious organizations well known for providing humanitarian and disaster relief service. Semistructured interviews yielded data that were analyzed qualitatively, using McCracken's five-step process for analysis. We found that volunteers used three different abilities to solve problems: drawing upon experience to create strategies, maintaining emotional stability in the midst of trying circumstances, and applying strategies in a context-sensitive manner. These findings illustrate that these factors, which are comparable to those used in solving everyday problems, are unique in the way they are applied to intensive volunteering. The volunteers' sharing of knowledge, experience, and support with each other were also noticeable in their accounts of their service. This sharing contributed strongly to their sense of emotional stability and effectiveness in solving problems. © The Author(s) 2015.

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

    Directory of Open Access Journals (Sweden)

    Fethiye Müge SAKAR

    2016-11-01

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

  7. Post-head-emergence frost in wheat and barley: defining the problem, assessing the damage, and identifying resistance.

    Science.gov (United States)

    Frederiks, T M; Christopher, J T; Sutherland, M W; Borrell, A K

    2015-06-01

    Radiant frost is a significant production constraint to wheat (Triticum aestivum) and barley (Hordeum vulgare), particularly in regions where spring-habit cereals are grown through winter, maturing in spring. However, damage to winter-habit cereals in reproductive stages is also reported. Crops are particularly susceptible to frost once awns or spikes emerge from the protection of the flag leaf sheath. Post-head-emergence frost (PHEF) is a problem distinct from other cold-mediated production constraints. To date, useful increased PHEF resistance in cereals has not been identified. Given the renewed interest in reproductive frost damage in cereals, it is timely to review the problem. Here we update the extent and impacts of PHEF and document current management options to combat this challenge. We clarify terminology useful for discussing PHEF in relation to chilling and other freezing stresses. We discuss problems characterizing radiant frost, the environmental conditions leading to PHEF damage, and the effects of frost at different growth stages. PHEF resistant cultivars would be highly desirable, to both reduce the incidence of direct frost damage and to allow the timing of crop maturity to be managed to maximize yield potential. A framework of potential adaptation mechanisms is outlined. Clarification of these critical issues will sharpen research focus, improving opportunities to identify genetic sources for improved PHEF resistance. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Inverse Problem and Variation Method to Optimize Cascade Heat Exchange Network in Central Heating System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yin; WEI Zhiyuan; ZHANG Yinping; WANG Xin

    2017-01-01

    Urban heating in northern China accounts for 40% of total building energy usage.In central heating systems,heat is often transfened from heat source to users by the heat network where several heat exchangers arc installed at heat source,substations and terminals respectively.For given overall heating capacity and heat source temperarure,increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving.In this paper,the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in series is established.Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity,the optimal heat exchange area distribution and the medium fluids' flow rates are determined through inverse problem and variation method.The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger.It also indicates that in order to improve the thernmal performance of the whole system,more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small.This work is important for guiding the optimization design of practical cascade heating systems.

  9. Variational multiscale enrichment method with mixed boundary conditions for elasto-viscoplastic problems

    Science.gov (United States)

    Zhang, Shuhai; Oskay, Caglar

    2015-04-01

    This manuscript presents the formulation and implementation of the variational multiscale enrichment (VME) method for the analysis of elasto-viscoplastic problems. VME is a global-local approach that allows accurate fine scale representation at small subdomains, where important physical phenomena are likely to occur. The response within far-fields is idealized using a coarse scale representation. The fine scale representation not only approximates the coarse grid residual, but also accounts for the material heterogeneity. A one-parameter family of mixed boundary conditions that range from Dirichlet to Neumann is employed to study the effect of the choice of the boundary conditions at the fine scale on accuracy. The inelastic material behavior is modeled using Perzyna type viscoplasticity coupled with flow stress evolution idealized by the Johnson-Cook model. Numerical verifications are performed to assess the performance of the proposed approach against the direct finite element simulations. The results of verification studies demonstrate that VME with proper boundary conditions accurately model the inelastic response accounting for material heterogeneity.

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

    Science.gov (United States)

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

    2018-04-01

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

  11. Variational equations for the solution of the hartree-fock problem with angular momentum projection before the variation

    International Nuclear Information System (INIS)

    Schmid, K.W.; Gruemmer, F.

    1979-01-01

    A variational principle is used to determine the optimal angular momentum projected one determinant approach to the N-nucleon yrast-wave function for a given total spin value. The solution is given in terms of a set of coupled nonlinear equations. Besides an orthonormality constraint for the occupied orbits and a normalization conditions for the total wave function, this set consists out of a matrix equation taking care of the fact that the spin-projected wave function does not depend on the orientation of the intrinsic determinant it is based on, and a second subset of equations, which can be considered as a Thouless theorem for the spin-projected N-nucleon state, and desribes the diagonalization of the total Hamiltonian in the subspace of linear independent N-nucleon shell model configurations contained in the test-determinant. Furthermore, a numerical method for the solution of these equations is proposed and an extension of the theory for the description of excited bands is given. Finally, the consistency of the equations is checked by solving them for a simple example analytically. (orig.)

  12. A HIGH ORDER SOLUTION OF THREE DIMENSIONAL TIME DEPENDENT NONLINEAR CONVECTIVE-DIFFUSIVE PROBLEM USING MODIFIED VARIATIONAL ITERATION METHOD

    Directory of Open Access Journals (Sweden)

    Pratibha Joshi

    2014-12-01

    Full Text Available In this paper, we have achieved high order solution of a three dimensional nonlinear diffusive-convective problem using modified variational iteration method. The efficiency of this approach has been shown by solving two examples. All computational work has been performed in MATHEMATICA.

  13. Application of the Variational Iteration Method to the Initial Value Problems of Q-difference Equations-Some Examples

    Directory of Open Access Journals (Sweden)

    Yu Xiang Zeng

    2013-12-01

    Full Text Available The q-difference equations are a class of important models both in q-calculus and applied sciences. The variational iteration method is extended to approximately solve the initial value problems of q-difference equations. A q-analogue of the Lagrange multiplier is presented and three examples are illustrated to show the method's efficiency.

  14. Three-Field Modelling of Nonlinear Nonsmooth Boundary Value Problems and Stability of Differential Mixed Variational Inequalities

    Directory of Open Access Journals (Sweden)

    J. Gwinner

    2013-01-01

    Full Text Available The purpose of this paper is twofold. Firstly we consider nonlinear nonsmooth elliptic boundary value problems, and also related parabolic initial boundary value problems that model in a simplified way steady-state unilateral contact with Tresca friction in solid mechanics, respectively, stem from nonlinear transient heat conduction with unilateral boundary conditions. Here a recent duality approach, that augments the classical Babuška-Brezzi saddle point formulation for mixed variational problems to twofold saddle point formulations, is extended to the nonsmooth problems under consideration. This approach leads to variational inequalities of mixed form for three coupled fields as unknowns and to related differential mixed variational inequalities in the time-dependent case. Secondly we are concerned with the stability of the solution set of a general class of differential mixed variational inequalities. Here we present a novel upper set convergence result with respect to perturbations in the data, including perturbations of the associated nonlinear maps, the nonsmooth convex functionals, and the convex constraint set. We employ epiconvergence for the convergence of the functionals and Mosco convergence for set convergence. We impose weak convergence assumptions on the perturbed maps using the monotonicity method of Browder and Minty.

  15. Learning the solution sparsity of an ill-posed linear inverse problem with the Variational Garrote

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Hansen, Sofie Therese; Hansen, Lars Kai

    2013-01-01

    the Variational Garrote, we show, has a wide range of parameter values for which it at the same time provides low test error and high retrieval of the true feature locations. Furthermore, the new form of the prior and associated hyper-prior leads to a simple update rule in a Bayesian variational inference scheme...

  16. mathematical model of thermal explosion, the dual variational formulation of nonlinear problem, alternative functional

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    in its plane, and in the circular cylinder unlimited in length.An approximate numerical solution of the differential equation that is included in a nonlinear mathematical model of the thermal explosion enables us to obtain quantitative estimates of combination of determining parameters at which the limit state occurs in areas of not only canonical form. A capability to study of the thermal explosion state can be extended in the context of development of mathematical modeling methods, including methods of model analysis to describe the thermal state of solids.To analyse a mathematical model of the thermal explosion in a homogeneous solid the paper uses a variational approach based on the dual variational formulation of the appropriate nonlinear stationary problem of heat conduction in such a body. This formulation contains two alternative functional reaching the matching values in their stationary points corresponding to the true temperature distribution. This functional feature allows you to not only get an approximate quantitative estimate of the combination of parameters that determine the thermal explosion state, but also to find the greatest possible error in such estimation.

  17. The problem of defining myth

    Directory of Open Access Journals (Sweden)

    Lauri Honko

    1972-01-01

    Full Text Available The first thing that one realises in trying to grasp the semantic implications of myth is that myth can cover an extremely wide field. The way in which the term myth is commonly used reveals, too, that the word is loaded with emotional overtones. These overtones creep not only into common parlance but also, somewhat surprisingly, into scientific usage. That myth does, in fact, carry emotional overtones in this way is perhaps most easily seen if we think of terms such as prayer, liturgy, ritual drama, spell: they are all used for different religious genres but would seem to be more neutral than myth. It appears to be difficult for many scholars to discuss myth simply as a form of religious communication, as one genre among other genres. If one differentiates between four levels, namely, form, content, function and context, it is much easier to encounter the varied uses which the concept has acquired in scientific literature. By this it is possible to delimit and yet be flexible at the same time. There is no need to welcome with open arms just any traditions into the fold of myth research: but nor is it necessary to exclude, for example, studies of myth where the context criterion, i.e. a context of ritual, is not fulfilled. The degree of flexibility that can be achieved is dependent on the approach that the scholar has chosen.

  18. Vectorial Ekeland Variational Principles and Inclusion Problems in Cone Quasi-Uniform Spaces

    Directory of Open Access Journals (Sweden)

    Jiang Zhu

    2012-01-01

    principle, vectorial quasiequilibrium principle are obtained. Also, several other important principles in nonlinear analysis are extended to cone quasi-uniform spaces. The results of this paper extend, generalize, and improve the corresponding results for Ekeland's variational principles of the directed vectorial perturbation type and other generalizations of Ekeland's variational principles in the setting of F-type topological space and quasi-metric spaces in the literatures. Even in usual real metric spaces, some of our results are new.

  19. Hybrid Proximal-Point Methods for Zeros of Maximal Monotone Operators, Variational Inequalities and Mixed Equilibrium Problems

    Directory of Open Access Journals (Sweden)

    Kriengsak Wattanawitoon

    2011-01-01

    Full Text Available We prove strong and weak convergence theorems of modified hybrid proximal-point algorithms for finding a common element of the zero point of a maximal monotone operator, the set of solutions of equilibrium problems, and the set of solution of the variational inequality operators of an inverse strongly monotone in a Banach space under different conditions. Moreover, applications to complementarity problems are given. Our results modify and improve the recently announced ones by Li and Song (2008 and many authors.

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

    NARCIS (Netherlands)

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

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

  1. Treatment of Multiply Controlled Problem Behavior with Procedural Variations of Differential Reinforcement

    Science.gov (United States)

    Neidert, Pamela L.; Iwata, Brian A.; Dozier, Claudia L.

    2005-01-01

    We describe the assessment and treatment of 2 children with autism spectrum disorder whose problem behaviors (self-injury, aggression, and disruption) were multiply controlled. Results of functional analyses indicated that the children's problem behaviors were maintained by both positive reinforcement (attention) and negative reinforcement (escape…

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

    Directory of Open Access Journals (Sweden)

    Jianke Zhang

    2018-01-01

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

  3. Compressed modes for variational problems in mathematical physics and compactly supported multiresolution basis for the Laplace operator

    Science.gov (United States)

    Ozolins, Vidvuds; Lai, Rongjie; Caflisch, Russel; Osher, Stanley

    2014-03-01

    We will describe a general formalism for obtaining spatially localized (``sparse'') solutions to a class of problems in mathematical physics, which can be recast as variational optimization problems, such as the important case of Schrödinger's equation in quantum mechanics. Sparsity is achieved by adding an L1 regularization term to the variational principle, which is shown to yield solutions with compact support (``compressed modes''). Linear combinations of these modes approximate the eigenvalue spectrum and eigenfunctions in a systematically improvable manner, and the localization properties of compressed modes make them an attractive choice for use with efficient numerical algorithms that scale linearly with the problem size. In addition, we introduce an L1 regularized variational framework for developing a spatially localized basis, compressed plane waves (CPWs), that spans the eigenspace of a differential operator, for instance, the Laplace operator. Our approach generalizes the concept of plane waves to an orthogonal real-space basis with multiresolution capabilities. Supported by NSF Award DMR-1106024 (VO), DOE Contract No. DE-FG02-05ER25710 (RC) and ONR Grant No. N00014-11-1-719 (SO).

  4. Strongly coupled single-phase flow problems: Effects of density variation, hydrodynamic dispersion, and first order decay

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.; Pruess, K. [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1995-03-01

    We have developed TOUGH2 modules for strongly coupled flow and transport that include full hydrodynamic dispersion. T2DM models tow-dimensional flow and transport in systems with variable salinity, while T32DMR includes radionuclide transport with first-order decay of a parent-daughter chain of radionuclide components in variable salinity systems. T2DM has been applied to a variety of coupled flow problems including the pure solutal convection problem of Elder and the mixed free and forced convection salt-dome flow problem. In the Elder and salt-dome flow problems, density changes of up to 20% caused by brine concentration variations lead to strong coupling between the velocity and brine concentration fields. T2DM efficiently calculates flow and transport for these problems. We have applied T2DMR to the dispersive transport and decay of radionuclide tracers in flow fields with permeability heterogeneities and recirculating flows. Coupling in these problems occurs by velocity-dependent hydrodynamic dispersion. Our results show that the maximum daughter species concentration may occur fully within a recirculating or low-velocity region. In all of the problems, we observe very efficient handling of the strongly coupled flow and transport processes.

  5. Variational methods for boundary value problems for systems of elliptic equations

    CERN Document Server

    Lavrent'ev, M A

    2012-01-01

    Famous monograph by a distinguished mathematician presents an innovative approach to classical boundary value problems. The treatment employs the basic scheme first suggested by Hilbert and developed by Tonnelli. 1963 edition.

  6. Identification and observability problems of the induction motor for sensor-less industrial speed variation; Problemes d'identification et d'observabilite du moteur a induction pour la variation de vitesse industrielle sans capteur

    Energy Technology Data Exchange (ETDEWEB)

    Malrait, F.

    2001-02-15

    In order to improve the efficiency of a speed variator or to make autonomous the control of induction motors without mechanical sensor, the speed variator must integrate with a good precision the parameters of the motor to which it is connected. In this work, an identification phase when the motor is off is proposed. This raises the problem of the modeling of the induction motor and of the power stage (saturation model, voltage drop in the power stage components) in an unusual operation zone for a speed variator. The knowledge of the off-line electrical parameters is thus not sufficient. During normal operation, the thermal drift of resistors leads to a parametric error which can create blocking problems in the low sped domain or which can significantly lower the efficiency. The low-speed zone has been analyzed. This zone contains some intrinsic properties of the induction motor: instability, non-observability (first order). The synthesis of an observer of the induction motor is proposed which is based on the linearization of the system around a trajectory. A construction method has been developed to generate a non-singular observer for a system changing with time and having observability singularities. This result comes from this study on systems having controllability singularities for linear systems with time-variable coefficients. An exogenous loop is explicitly proposed which allows to transform the original system into integrator chains without singularities. (J.S.)

  7. Mean-Variance Portfolio Selection Problem with Stochastic Salary for a Defined Contribution Pension Scheme: A Stochastic Linear-Quadratic-Exponential Framework

    Directory of Open Access Journals (Sweden)

    Charles Nkeki

    2013-11-01

    Full Text Available This paper examines a mean-variance portfolio selection problem with stochastic salary and inflation protection strategy in the accumulation phase of a defined contribution (DC pension plan. The utility function is assumed to be quadratic. It was assumed that the flow of contributions made by the PPM are invested into a market that is characterized by a cash account, an inflation-linked bond and a stock. In this paper, inflationlinked bond is traded and used to hedge inflation risks associated with the investment. The aim of this paper is to maximize the expected final wealth and minimize its variance. Efficient frontier for the three classes of assets (under quadratic utility function that will enable pension plan members (PPMs to decide their own wealth and risk in their investment profile at retirement was obtained.

  8. The numerical solution of total variation minimization problems in image processing

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, C.R.; Oman, M.E. [Montana State Univ., Bozeman, MT (United States)

    1994-12-31

    Consider the minimization of penalized least squares functionals of the form: f(u) = 1/2 ({parallel}Au {minus} z{parallel}){sup 2} + {alpha}{integral}{sub {Omega}}{vert_bar}{del}u{vert_bar}dx. Here A is a bounded linear operator, z represents data, {parallel} {center_dot} {parallel} is a Hilbert space norm, {alpha} is a positive parameter, {integral}{sub {Omega}}{vert_bar}{del}u{vert_bar} dx represents the total variation (TV) of a function u {element_of} BV ({Omega}), the class of functions of bounded variation on a bounded region {Omega}, and {vert_bar} {center_dot} {vert_bar} denotes Euclidean norm. In image processing, u represents an image which is to be recovered from noisy data z. Certain {open_quotes}blurring processes{close_quotes} may be represented by the action of an operator A on the image u.

  9. Fractional variational problems and particle in cell gyrokinetic simulations with fuzzy logic approach for tokamaks

    Directory of Open Access Journals (Sweden)

    Rastović Danilo

    2009-01-01

    Full Text Available In earlier Rastovic's papers [1] and [2], the effort was given to analyze the stochastic control of tokamaks. In this paper, the deterministic control of tokamak turbulence is investigated via fractional variational calculus, particle in cell simulations, and fuzzy logic methods. Fractional integrals can be considered as approximations of integrals on fractals. The turbulent media could be of the fractal structure and the corresponding equations should be changed to include the fractal features of the media.

  10. Who Defines Culturally Acceptable Health Access? Universal rights, healthcare politics and the problems of two Mbya-Guarani communities in the Misiones Province, Argentina

    Directory of Open Access Journals (Sweden)

    A. Sy

    2013-05-01

    Full Text Available This paper seeks to analyze the problems and barriers encountered when public policy health programs are implemented within indigenous communities. The initial stumbling block for such programs is precisely the idea of health as a universal right, around which emerges a characterization and stereotype of the indigenous population who are consequently addressed as a homogenized unit subsisting below the poverty line, and marginalized. A result of this is that the  particular ethno-cultural register of such populations fails to be acknowledged and form part of a systematic public health policy. Consequently, health policies become generalized in character, unable to variate and differentiate according to the culturally specific contexts within which health outreach and access is needed. In this sense, based on the results of an ethnographic study carried out in two Mbya-Guaraní indigenous communities of Argentina, our study highlights as to how public policies of indigenous health are perceived, their impact value measured, and the meanings which emerge locally about the policy practices implemented.Lastly, our study identifies problems that can be avoided in fulfilling the goals of universal policies and certain questions to consider at the time of policy design and implementation.

  11. Childhood socioeconomic status and longitudinal patterns of alcohol problems: Variation across etiological pathways in genetic risk.

    Science.gov (United States)

    Barr, Peter B; Silberg, Judy; Dick, Danielle M; Maes, Hermine H

    2018-05-14

    Childhood socioeconomic status (SES) is an important aspect of early life environment associated with later life health/health behaviors, including alcohol misuse. However, alcohol misuse is modestly heritable and involves differing etiological pathways. Externalizing disorders show significant genetic overlap with substance use, suggesting an impulsivity pathway to alcohol misuse. Alcohol misuse also overlaps with internalizing disorders, suggesting alcohol is used to cope. These differing pathways could lead to different patterns over time and/or differential susceptibility to environmental conditions, such as childhood SES. We examine whether: 1) genetic risk for externalizing and internalizing disorders influence trajectories of alcohol problems across adolescence to adulthood, 2) childhood SES alters genetic risk these disorders on trajectories of alcohol problems, and 3) these patterns are consistent across sex. We find modest evidence of gene-environment interaction. Higher childhood SES increases the risk of alcohol problems in late adolescence/early adulthood, while lower childhood SES increases the risk of alcohol problems in later adulthood, but only among males at greater genetic risk of externalizing disorders. Females from lower SES families with higher genetic risk of internalizing or externalizing disorders have greater risk of developing alcohol problems. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Newton-type method for the variational discretization of topology optimization problems

    DEFF Research Database (Denmark)

    Evgrafov, Anton

    2013-01-01

    We present a locally quadratically convergent optimization algorithm for solving topology optimization problems. The distinguishing feature of the algorithm is to treat the design as a smooth function of the state and not vice versa as in the traditional nested approach to topology optimization, ...

  13. The Shape of a Sausage: A Challenging Problem in the Calculus of Variations

    Science.gov (United States)

    Deakin, Michael A. B.

    2010-01-01

    Many familiar household objects (such as sausages) involve the maximization of a volume under geometric constraints. A flexible but inextensible membrane bounds a volume which is to be filled to capacity. In the case of the sausage, a full analytic solution is here provided. Other related but more difficult problems seem to demand approximate…

  14. Time-dependent post-imperative negative variation indicates adaptation and problem solving in migraine patients.

    Science.gov (United States)

    Kropp, Peter; Brecht, Ines-Beatrice; Niederberger, Uwe; Kowalski, Jens; Schröder, Dietmar; Thome, Johannes; Meyer, Wolfgang; Wallasch, Thomas-Martin; Hilgendorf, Inken; Gerber, Wolf-Dieter

    2012-10-01

    According to the Seligman theory of learned helplessness, depression is caused by a repetitive experience of loss of control resulting in internal, stable and global attributional styles for negative events. In depressed patients and healthy controls experiencing such events, an increased amplitude of the post-imperative negative variation (PINV) has been described. The aim of the study was to investigate a possible correlation between migraine, depression, learned helplessness and PINV. 24 patients suffering from migraine without aura and 24 healthy controls were exposed to a situation of loss of control whilst the contingent negative variation (CNV) from C3, C4 and Cz were recorded. Before conducting the experiment, the subjects were asked to answer the Beck Depression Inventory (BDI) and the German attributional style questionnaire (GASQ). Amplitudes of total CNV, early and late component and PINV were calculated in eight blocks of four recordings each. The results confirm findings of a pronounced PINV in situations of loss of control, though high amplitudes were not correlated with low values in the GASQ and therefore with learned helplessness. High PINV in migraine patients correlated with high scores in the BDI and the list of the complaints questionnaire. However, this was not the case in healthy controls. In this experimental situation, PINV in migraine patients can be interpreted as an expectancy potential in order to avoid failure and helplessness.

  15. Use of variational principles for solution of infinitely redundant continuum problem with special reference to containment vessels

    International Nuclear Information System (INIS)

    Stefanou, G.D.

    1982-01-01

    The calculation of time-deepndent stresses in concrete structures operating at elevated temperatures is discussed. The method described is of a direct formulation technique and it is based on the principles of the calculus of variation. The paper mainly deals with the application of the method to a large and infinitely redundant continuum problem. The analytical procedure of the variational principle is also described and the mathematical expressions are developed for uniaxial and biaxial stress problems. The solution for the biaxial state of stress is carried out by a two-dimensional finite element stiffness analysis. A step-by-step method developed by the author using two-dimensional finite element stiffness analysis is also described in APPENDIX 3. Both methods are then applied to a real problem for which experimental data exist from Ref. (1) Predicted analytical values obtained by both methods are compared with experimental results. The method is suitable for predicting the distribution of stress in the end slabs of containment vessels. These slabs are perforated to permit fuel loading by the charging machine. (author)

  16. Performance evaluation of firefly algorithm with variation in sorting for non-linear benchmark problems

    Science.gov (United States)

    Umbarkar, A. J.; Balande, U. T.; Seth, P. D.

    2017-06-01

    The field of nature inspired computing and optimization techniques have evolved to solve difficult optimization problems in diverse fields of engineering, science and technology. The firefly attraction process is mimicked in the algorithm for solving optimization problems. In Firefly Algorithm (FA) sorting of fireflies is done by using sorting algorithm. The original FA is proposed with bubble sort for ranking the fireflies. In this paper, the quick sort replaces bubble sort to decrease the time complexity of FA. The dataset used is unconstrained benchmark functions from CEC 2005 [22]. The comparison of FA using bubble sort and FA using quick sort is performed with respect to best, worst, mean, standard deviation, number of comparisons and execution time. The experimental result shows that FA using quick sort requires less number of comparisons but requires more execution time. The increased number of fireflies helps to converge into optimal solution whereas by varying dimension for algorithm performed better at a lower dimension than higher dimension.

  17. Race/Ethnic Based Genetic Variations in Human Genes: Defining the Genetic Evidence for Disparity of Prostate Cancer Risk and Mortality Between Different Populations

    National Research Council Canada - National Science Library

    Franklin, John

    1999-01-01

    .... The study will evaluate variations in androgen receptor gene, the vitamin D receptor gene, and the APOJ/clusterin gene by amplifying specific DNA segments from certain genes utilizing a commonly used...

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

    International Nuclear Information System (INIS)

    Scaramuzzino, F.

    2009-01-01

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

  19. On the use of a variational technique based on integral equations for plane acoustic and vibro-acoustic problems

    DEFF Research Database (Denmark)

    Brunskog, Jonas; Richard, Antoine Philippe André

    2016-01-01

    Problems such as sound insulation and absorption of plane structures in laboratory conditions can theoretically be described as an integral or integral-differential equation. This equation contains the Green’s function integrated over the surface, which describes the radiation from the surface....... A variational technique, well described by Morse and Ingard, has successfully been used for both absorption and sound insulation for a plane incident wave. The resulting formulas are surprisingly simple, accurate and robust. Moreover, they capture the physics of sound radiation of a finite surface well. However...

  20. Some global problems in gauge theories (Variations on a theme of Aharonov and Bohm)

    International Nuclear Information System (INIS)

    Wilczek, F.

    1989-12-01

    Several situations are discussed, in which the sort of global considerations made famous by Aharonov and Bohm in their discussion of the interaction of charged particles with magnetic flux tubes have important physical implications. It is argued that discrete gauge symmetries in the continuum make sense, and manifest themselves most clearly in Aharonov-Bohm type scattering of charged particles off string singularities. The existence of such discrete symmetries has important implications for the quantum mechanics of topologically non-trivial space-times in general and black holes in particular. It is argued that in the non-abelian case essentially new features arise, most notably that the symmetry group of the homogeneous ground state generally ceases to be globally defined in the presence of a string. When continuous rather than discrete symmetries are involved, a variety of fascinating and as yet poorly understood dynamical effects occur. Perhaps the most striking is a new form of string superconductivity, that exists for purely topological reasons, and is not well modeled by regarding the string as a superconducting wire. 8 refs., 2 figs

  1. Multistep Hybrid Extragradient Method for Triple Hierarchical Variational Inequalities

    Directory of Open Access Journals (Sweden)

    Zhao-Rong Kong

    2013-01-01

    Full Text Available We consider a triple hierarchical variational inequality problem (THVIP, that is, a variational inequality problem defined over the set of solutions of another variational inequality problem which is defined over the intersection of the fixed point set of a strict pseudocontractive mapping and the solution set of the classical variational inequality problem. Moreover, we propose a multistep hybrid extragradient method to compute the approximate solutions of the THVIP and present the convergence analysis of the sequence generated by the proposed method. We also derive a solution method for solving a system of hierarchical variational inequalities (SHVI, that is, a system of variational inequalities defined over the intersection of the fixed point set of a strict pseudocontractive mapping and the solution set of the classical variational inequality problem. Under very mild conditions, it is proven that the sequence generated by the proposed method converges strongly to a unique solution of the SHVI.

  2. On a free-surface problem with moving contact line: From variational principles to stable numerical approximations

    Science.gov (United States)

    Fumagalli, Ivan; Parolini, Nicola; Verani, Marco

    2018-02-01

    We analyze a free-surface problem described by time-dependent Navier-Stokes equations. Surface tension, capillary effects and wall friction are taken into account in the evolution of the system, influencing the motion of the contact line - where the free surface hits the wall - and of the dynamics of the contact angle. The differential equations governing the phenomenon are first derived from the variational principle of minimum reduced dissipation, and then discretized by means of the ALE approach. The numerical properties of the resulting scheme are investigated, drawing a parallel with the physical properties holding at the continuous level. Some instability issues are addressed in detail, in the case of an explicit treatment of the geometry, and novel additional terms are introduced in the discrete formulation in order to damp the instabilities. Numerical tests assess the suitability of the approach, the influence of the parameters, and the effectiveness of the new stabilizing terms.

  3. Defining microbial community composition and seasonal variation in a sewage treatment plant in India using a down-flow hanging sponge reactor.

    Science.gov (United States)

    Nomoto, Naoki; Hatamoto, Masashi; Hirakata, Yuga; Ali, Muntjeer; Jayaswal, Komal; Iguchi, Akinori; Okubo, Tsutomu; Takahashi, Masanobu; Kubota, Kengo; Tagawa, Tadashi; Uemura, Shigeki; Yamaguchi, Takashi; Harada, Hideki

    2018-05-01

    The characteristics of the microbial community in a practical-scale down-flow hanging sponge (DHS) reactor, high in organic matter and sulfate ion concentration, and the seasonal variation of the microbial community composition were investigated. Microorganisms related to sulfur oxidation and reduction (2-27%), as well as Leucobacter (7.50%), were abundant in the reactor. Anaerobic bacteria (27-38% in the first layer) were also in abundance and were found to contribute to the removal of organic matter from the sewage in the reactor. By comparing the Simpson index, the abundance-based coverage estimator (ACE) index, and the species composition of the microbial community across seasons (summer/dry, summer/rainy, autumn/dry, and winter/dry), the microbial community was found to change in composition only during the winter season. In addition to the estimation of seasonal variation, the difference in the microbial community composition along the axes of the DHS reactor was investigated for the first time. Although the abundance of each bacterial species differed along both axes of the reactor, the change of the community composition in the reactor was found to be greater along the vertical axis than the horizontal axis of the DHS reactor.

  4. Define Project

    DEFF Research Database (Denmark)

    Munk-Madsen, Andreas

    2005-01-01

    "Project" is a key concept in IS management. The word is frequently used in textbooks and standards. Yet we seldom find a precise definition of the concept. This paper discusses how to define the concept of a project. The proposed definition covers both heavily formalized projects and informally...... organized, agile projects. Based on the proposed definition popular existing definitions are discussed....

  5. "Dermatitis" defined.

    Science.gov (United States)

    Smith, Suzanne M; Nedorost, Susan T

    2010-01-01

    The term "dermatitis" can be defined narrowly or broadly, clinically or histologically. A common and costly condition, dermatitis is underresourced compared to other chronic skin conditions. The lack of a collectively understood definition of dermatitis and its subcategories could be the primary barrier. To investigate how dermatologists define the term "dermatitis" and determine if a consensus on the definition of this term and other related terms exists. A seven-question survey of dermatologists nationwide was conducted. Of respondents (n  =  122), half consider dermatitis to be any inflammation of the skin. Nearly half (47.5%) use the term interchangeably with "eczema." Virtually all (> 96%) endorse the subcategory "atopic" under the terms "dermatitis" and "eczema," but the subcategories "contact," "drug hypersensitivity," and "occupational" are more highly endorsed under the term "dermatitis" than under the term "eczema." Over half (55.7%) personally consider "dermatitis" to have a broad meaning, and even more (62.3%) believe that dermatologists as a whole define the term broadly. There is a lack of consensus among experts in defining dermatitis, eczema, and their related subcategories.

  6. A model reduction approach for the variational estimation of vascular compliance by solving an inverse fluid–structure interaction problem

    International Nuclear Information System (INIS)

    Bertagna, Luca; Veneziani, Alessandro

    2014-01-01

    Scientific computing has progressively become an important tool for research in cardiovascular diseases. The role of quantitative analyses based on numerical simulations has moved from ‘proofs of concept’ to patient-specific investigations, thanks to a strong integration between imaging and computational tools. However, beyond individual geometries, numerical models require the knowledge of parameters that are barely retrieved from measurements, especially in vivo. For this reason, recently cardiovascular mathematics considered data assimilation procedures for extracting the knowledge of patient-specific parameters from measures and images. In this paper, we consider specifically the quantification of vascular compliance, i.e. the parameter quantifying the tendency of arterial walls to deform under blood stress. Following up a previous paper, where a variational data assimilation procedure was proposed, based on solving an inverse fluid–structure interaction problem, here we consider model reduction techniques based on a proper orthogonal decomposition approach to accomplish the solution of the inverse problem in a computationally efficient way. (paper)

  7. Variation in Wood Quality in White Spruce (Picea Glauca (Moench Voss. Part I. Defining the Juvenile–Mature Wood Transition Based on Tracheid Length

    Directory of Open Access Journals (Sweden)

    Cyriac Serge Mvolo

    2015-01-01

    Full Text Available Estimations of transition age (TA and juvenile wood proportion (JWP are important for wood industries due to their impact on end-product quality. However, the relationships between analytical determination of TA based on tracheid length (TL and recognized thresholds for adequate end products have not yet been established. In this study, we used three different statistical models to estimate TA in white spruce (Picea glauca (Moench Voss based on TL radial variation. We compared the results with technological maturity. A two-millimeter threshold, previously suggested for good paper tear strength, was used. Tracheid length increased from pith to bark and from breast height to upper height. Juvenile wood (JW was conical with the three models. At breast height, TA ranged from 11 to 27 years and JWP ranged from 15.3% to 47.5% across the three models. The linear mixed model produced more conservative estimates than the maximum-quadratic-linear (M_Q_L model. Both the linear mixed model and the M_Q_L model produced more conservative TA estimates than the piecewise model. TA estimates by the MIXED model, and to a lesser extent by the M_Q_L model, were equivalent to those for real mature wood, whereas TA estimates by the piecewise model were considerably lower, falling into the transition wood area.

  8. Defining chaos.

    Science.gov (United States)

    Hunt, Brian R; Ott, Edward

    2015-09-01

    In this paper, we propose, discuss, and illustrate a computationally feasible definition of chaos which can be applied very generally to situations that are commonly encountered, including attractors, repellers, and non-periodically forced systems. This definition is based on an entropy-like quantity, which we call "expansion entropy," and we define chaos as occurring when this quantity is positive. We relate and compare expansion entropy to the well-known concept of topological entropy to which it is equivalent under appropriate conditions. We also present example illustrations, discuss computational implementations, and point out issues arising from attempts at giving definitions of chaos that are not entropy-based.

  9. Defining Cyberbullying.

    Science.gov (United States)

    Englander, Elizabeth; Donnerstein, Edward; Kowalski, Robin; Lin, Carolyn A; Parti, Katalin

    2017-11-01

    Is cyberbullying essentially the same as bullying, or is it a qualitatively different activity? The lack of a consensual, nuanced definition has limited the field's ability to examine these issues. Evidence suggests that being a perpetrator of one is related to being a perpetrator of the other; furthermore, strong relationships can also be noted between being a victim of either type of attack. It also seems that both types of social cruelty have a psychological impact, although the effects of being cyberbullied may be worse than those of being bullied in a traditional sense (evidence here is by no means definitive). A complicating factor is that the 3 characteristics that define bullying (intent, repetition, and power imbalance) do not always translate well into digital behaviors. Qualities specific to digital environments often render cyberbullying and bullying different in circumstances, motivations, and outcomes. To make significant progress in addressing cyberbullying, certain key research questions need to be addressed. These are as follows: How can we define, distinguish between, and understand the nature of cyberbullying and other forms of digital conflict and cruelty, including online harassment and sexual harassment? Once we have a functional taxonomy of the different types of digital cruelty, what are the short- and long-term effects of exposure to or participation in these social behaviors? What are the idiosyncratic characteristics of digital communication that users can be taught? Finally, how can we apply this information to develop and evaluate effective prevention programs? Copyright © 2017 by the American Academy of Pediatrics.

  10. Variation in the Early Trajectories of Autism Symptoms Is Related to the Development of Language, Cognition, and Behavior Problems.

    Science.gov (United States)

    Visser, Janne C; Rommelse, Nanda N J; Lappenschaar, Martijn; Servatius-Oosterling, Iris J; Greven, Corina U; Buitelaar, Jan K

    2017-08-01

    The objectives of this study were to model more homogeneous subgroups within autism spectrum disorder (ASD) based on early trajectories of core symptoms; and to further characterize these subgroups in terms of trajectories of language, cognition, co-occurring (attention-deficit/hyperactivity disorder [ADHD]-related) traits and clinical outcome diagnosis. Children (N = 203) referred for possible ASD at ages 1 to 4 years were assessed at three time points at intervals ranging from 9 months to 3 years. Assessments included standardized measures for ASD (Autism Diagnostic Observation Schedule [ADOS]), language (ADOS-language item), nonverbal IQ (NV-IQ; different tests adequate to chronological/mental age), and parent-reported behavioral problems (Infant-Toddler Social and Emotional Assessment, Child Behavior Checklist). Latent-class growth curve analysis with ADOS total scores led to the identification of three main stable and two small improving groups: a severe-stable group (19.5% of sample)-the only group without considerable language improvement-showed persistent low NV-IQ and marked increase in attention problems over time; a moderate-stable group (21.7%) with below-average increasing NV-IQ; and a mild-stable group (48%) with stable-average NV-IQ and the highest scores on ADHD-related traits, whose ASD outcome diagnoses increased despite stable-low ASD scores. Two groups (each 5.4%) improved: one moved from severe to moderate ASD scores, and the other moved from moderate to mild/nonspectrum scores. Both of these groups improved on language, NV-IQ, and ADHD-related traits. Results support the high stability of ASD symptoms into various severity levels, but also highlight the significant contribution of non-ASD domains in defining and explaining the different ASD trajectories. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. Creating a pediatric digital library for pediatric health care providers and families: using literature and data to define common pediatric problems.

    Science.gov (United States)

    D'Alessandro, Donna; Kingsley, Peggy

    2002-01-01

    The goal of this study was to complete a literature-based needs assessment with regard to common pediatric problems encountered by pediatric health care providers (PHCPs) and families, and to develop a problem-based pediatric digital library to meet those needs. The needs assessment yielded 65 information sources. Common problems were identified and categorized, and the Internet was manually searched for authoritative Web sites. The created pediatric digital library (www.generalpediatrics.com) used a problem-based interface and was deployed in November 1999. From November 1999 to November 2000, the number of hyperlinks and authoritative Web sites increased 51.1 and 32.2 percent, respectively. Over the same time, visitors increased by 57.3 percent and overall usage increased by 255 percent. A pediatric digital library has been created that begins to bring order to general pediatric resources on the Internet. This pediatric digital library provides current, authoritative, easily accessed pediatric information whenever and wherever the PHCPs and families want assistance.

  12. State Decision-Makers Guide for Hazardous Waste Management: Defining Hazardous Wastes, Problem Recognition, Land Use, Facility Operations, Conceptual Framework, Policy Issues, Transportation.

    Science.gov (United States)

    Corson, Alan; And Others

    Presented are key issues to be addressed by state, regional, and local governments and agencies in creating effective hazardous waste management programs. Eight chapters broadly frame the topics which state-level decision makers should consider. These chapters include: (1) definition of hazardous waste; (2) problem definition and recognition; (3)…

  13. Promoting Self-Directed Learning in Developing or Poorly Defined Subject Areas: A Problem-Based Course in Molecular Biology, Genetics, and Cancer.

    Science.gov (United States)

    Edmondson, Katherine M.

    A new problem-based course in molecular biology, genetics, and cancer for first-year veterinary students was developed at the College of Veterinary Medicine at Cornell University (New York). The course was developed out of a desire to foster student-centered and lifelong learning and to integrate basic and clinical science knowledge despite a lack…

  14. A New Result Concerning the Solvability of a Class of General Systems of Variational Equations with Nonmonotone Operators: Applications to Dirichlet and Neumann Nonlinear Problems

    Directory of Open Access Journals (Sweden)

    Luisa Toscano

    2016-01-01

    Full Text Available A new result of solvability for a wide class of systems of variational equations depending on parameters and governed by nonmonotone operators is found in a Banach real and reflexive space with applications to Dirichlet and Neumann problems related to nonlinear elliptic systems.

  15. Revisiting the concept of ‘chronic disease’ from the perspective of the episode of care model. Does the ratio of incidence to prevalence rate help us to define a problem as chronic?

    Directory of Open Access Journals (Sweden)

    Jean K Soler

    2013-12-01

    Full Text Available Background This is a study of the epidemiology of acute and chronic episodes of care (EoCs in the Transition Project in three countries. We studied the duration of EoCs for acute and chronic health problems and the relationship of incidence to prevalence rates for these EoCs.Method The Transition Project databases collect data on all elements of the doctor–patient encounter in family medicine. Family doctors code these elements using the International Classification of Primary Care.We used the data from three practice populations to study the duration of EoCs and the ratio of incidence to prevalence for common health problems.Results We found that chronic health problems tended to have proportionately longer duration EoCs, as expected, but also a lower incidence to prevalence rate ratio than acute health problems. Thus, the incidence to prevalence index could be used to define a chronic condition as one with a low ratio, below a defined threshold.Conclusions Chronic health problems tend to have longer duration EoCs, proportionately, across populations. This result is expected, but we found important similarities and differences which make defining a problem as chronic on the basis of time rather difficult. The ratio of incidence to prevalence rates has potential to categorise health problems into acute or chronic categories, at different ratio thresholds (such as 20, 30 or 50%. It seems to perform well in this study of three family practice populations, and is proposed to the scientific community for further evaluation.

  16. A Variationally Formulated Problem of the Stationary Heat Conduction in a Plate with Radiation Reduction Factor Increased under Temperature

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    dependence of the absorption factor on the local intensity of this radiation. Furthermore, it can be a significant dependence of this factor on the local value of the material temperature, reflecting the above-mentioned relationship between the absorption of electromagnetic wave energy and the excitation of material microparticles. This process can be described by Boltzmann distribution function that comprises the energy to activate microparticles and the local value of temperature.This paper presents a variational formulation of the nonlinear problem of stationary heat conduction in a plate for the case when the radiation reduction factor in relation to the Bouguer law depends on the local temperature. This formulation includes a functional that can have several fixed points corresponding to different steady states of the plate temperature. Analysis of the properties of this functional enabled us to identify the stationary points, which correspond to the realized temperature distribution in the plate.

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

    Directory of Open Access Journals (Sweden)

    Chowdhury Molhammad SR

    2000-01-01

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

  18. Fractional action-like variational problems in holonomic, non-holonomic and semi-holonomic constrained and dissipative dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    EL-Nabulsi, Ahmad Rami [Department of Nuclear and Energy Engineering, Cheju National University, Ara-dong 1, Jeju 690-756 (Korea, Republic of)], E-mail: nabulsiahmadrami@yahoo.fr

    2009-10-15

    We communicate through this work the fractional calculus of variations and its corresponding Euler-Lagrange equations in 1D constrained holonomic, non-holonomic, and semi-holonomic dissipative dynamical system. The extension of the laws obtained to the 2D space state is done. Some interesting consequences are revealed.

  19. Calculus of variations

    CERN Document Server

    Elsgolc, Lev D

    2007-01-01

    This concise text offers both professionals and students an introduction to the fundamentals and standard methods of the calculus of variations. In addition to surveys of problems with fixed and movable boundaries, it explores highly practical direct methods for the solution of variational problems.Topics include the method of variation in problems with fixed boundaries; variational problems with movable boundaries and other problems; sufficiency conditions for an extremum; variational problems of constrained extrema; and direct methods of solving variational problems. Each chapter features nu

  20. Variations on the planar Landau problem: canonical transformations, a purely linear potential and the half-plane

    International Nuclear Information System (INIS)

    Govaerts, Jan; Hounkonnou, M Norbert; Mweene, Habatwa V

    2009-01-01

    The ordinary Landau problem of a charged particle in a plane subjected to a perpendicular homogeneous and static magnetic field is reconsidered from different points of view. The role of phase space canonical transformations and their relation to a choice of gauge in the solution of the problem is addressed. The Landau problem is then extended to different contexts, in particular the singular situation of a purely linear potential term being added as an interaction, for which a complete purely algebraic solution is presented. This solution is then exploited to solve this same singular Landau problem in the half-plane, with as motivation the potential relevance of such a geometry for quantum Hall measurements in the presence of an electric field or a gravitational quantum well.

  1. Variations on the planar Landau problem: canonical transformations, a purely linear potential and the half-plane

    Energy Technology Data Exchange (ETDEWEB)

    Govaerts, Jan [Center for Particle Physics and Phenomenology (CP3), Institut de Physique Nucleaire, Universite catholique de Louvain (UCL), 2, Chemin du Cyclotron, B-1348 Louvain-la Neuve (Belgium); Hounkonnou, M Norbert [International Chair in Mathematical Physics and Applications (ICMPA-UNESCO Chair), University of Abomey-Calavi, 072 BP 50, Cotonou (Benin); Mweene, Habatwa V [Physics Department, University of Zambia, PO Box 32379, Lusaka (Zambia)], E-mail: Jan.Govaerts@uclouvain.be, E-mail: hounkonnou@yahoo.fr, E-mail: norbert.hounkonnou@cipma.uac.bj, E-mail: habatwamweene@yahoo.com, E-mail: hmweene@unza.zm

    2009-12-04

    The ordinary Landau problem of a charged particle in a plane subjected to a perpendicular homogeneous and static magnetic field is reconsidered from different points of view. The role of phase space canonical transformations and their relation to a choice of gauge in the solution of the problem is addressed. The Landau problem is then extended to different contexts, in particular the singular situation of a purely linear potential term being added as an interaction, for which a complete purely algebraic solution is presented. This solution is then exploited to solve this same singular Landau problem in the half-plane, with as motivation the potential relevance of such a geometry for quantum Hall measurements in the presence of an electric field or a gravitational quantum well.

  2. On advanced variational formulation of the method of lines and its application to the wave propagation problems

    CSIR Research Space (South Africa)

    Shatalov, M

    2012-09-01

    Full Text Available are transformed into systems of ordinary differential equations with initial conditions. This reduction is obtained by means of application of particular finite difference schemes to the spatial derivatives. Many of the wave propagation problems describing...

  3. Reconstructive schemes for variational iteration method within Yang-Laplace transform with application to fractal heat conduction problem

    Directory of Open Access Journals (Sweden)

    Liu Chun-Feng

    2013-01-01

    Full Text Available A reconstructive scheme for variational iteration method using the Yang-Laplace transform is proposed and developed with the Yang-Laplace transform. The identification of fractal Lagrange multiplier is investigated by the Yang-Laplace transform. The method is exemplified by a fractal heat conduction equation with local fractional derivative. The results developed are valid for a compact solution domain with high accuracy.

  4. Fasting plasma glucose and variation in cardiometabolic risk factors in people with high-risk HbA1c-defined prediabetes: A cross-sectional multiethnic study.

    Science.gov (United States)

    Srivanichakorn, Weerachai; Godsland, Ian F; Thomson, Hazel; Misra, Shivani; Phisalprapa, Pochamana; Charatcharoenwitthaya, Phunchai; Pramyothin, Pornpoj; Washirasaksiri, Chaiwat; Snehalatha, Chamukuttan; Ramachandran, Ambady; Alberti, K George M M; Johnston, Desmond G; Oliver, Nick S

    2017-12-01

    Variation in cardiometabolic risk in prediabetes and any impacts of ethnicity on such variation have been little studied. In an ethnically diverse dataset, selected according to a high-risk HbA1c-based definition of prediabetes, we have investigated relationships between glycaemia and cardiometabolic risk factors and the influence of ethnicity on these relationships. We undertook a cross-sectional analysis of baseline data from a diabetes prevention study in the UK and a chronic care clinic in Thailand, selected for people without diabetes (fasting plasma glucose fasting plasma glucose (FPG), blood pressure (BP), lipids and insulin resistance-related risk factors (IRFs). Independently of individual characteristics including ethnicity, only systolic BP was weakly associated with FPG (beta coefficient 1.76 (95%CI 0.10-3.42), p 0.03) and only LDL-c with IFG (FPG 5.6 to fasting glucose (FPG ≥ 6.1 to <7.0 mmol/L) were considered. Relative to White, South Asian ethnicity was independently associated with lower systolic and diastolic BP, Black with lower triglycerides, cholesterol/HDL-c ratio and having 2 or more IRFs, and Thai with lower cholesterol/HDL-c ratio and all three non-white ethnicities with lower total and LDL cholesterol. In high-risk HbA1c-defined prediabetes additional measurement of FPG will add little to evaluation of cardiometabolic risk. Additionally, UK Whites tend to have the most adverse cardiometabolic profile of any ethnic group. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Molecular subtypes in stage II-III colon cancer defined by genomic instability: early recurrence-risk associated with a high copy-number variation and loss of RUNX3 and CDKN2A.

    Directory of Open Access Journals (Sweden)

    Marianne Berg

    Full Text Available We sought to investigate various molecular subtypes defined by genomic instability that may be related to early death and recurrence in colon cancer.We sought to investigate various molecular subtypes defined by instability at microsatellites (MSI, changes in methylation patterns (CpG island methylator phenotype, CIMP or copy number variation (CNV in 8 genes. Stage II-III colon cancers (n = 64 were investigated by methylation-specific multiplex ligated probe amplification (MS-MLPA. Correlation of CNV, CIMP and MSI, with mutations in KRAS and BRAFV600E were assessed for overlap in molecular subtypes and early recurrence risk by uni- and multivariate regression.The CIMP phenotype occurred in 34% (22/64 and MSI in 27% (16/60 of the tumors, with noted CIMP/MSI overlap. Among the molecular subtypes, a high CNV phenotype had an associated odds ratio (OR for recurrence of 3.2 (95% CI 1.1-9.3; P = 0.026. Losses of CACNA1G (OR of 2.9, 95% CI 1.4-6.0; P = 0.001, IGF2 (OR of 4.3, 95% CI 1.1-15.8; P = 0.007, CDKN2A (p16 (OR of 2.0, 95% CI 1.1-3.6; P = 0.024, and RUNX3 (OR of 3.4, 95% CI 1.3-8.7; P = 0.002 were associated with early recurrence, while MSI, CIMP, KRAS or BRAF V600E mutations were not. The CNV was significantly higher in deceased patients (CNV in 6 of 8 compared to survivors (CNV in 3 of 8. Only stage and loss of RUNX3 and CDKN2A were significant in the multivariable risk-model for early recurrence.A high copy number variation phenotype is a strong predictor of early recurrence and death, and may indicate a dose-dependent relationship between genetic instability and outcome. Loss of tumor suppressors RUNX3 and CDKN2A were related to recurrence-risk and warrants further investigation.

  6. Acquisition Cycle Time: Defining the Problem

    Science.gov (United States)

    2016-04-01

    development cost and unit procurement cost, relative to the legacy systems that we replace or upgrade. This is not simply inflation or price hikes ; the new...costs, investigation of apparent inequities in Veterans’ Disability Benefit adjudications, and modeling and optimization of resource- constrained

  7. What type of rural? Assessing the variations in life expectancy at birth at small area-level for a small population province using classes of locally defined settlement types.

    Science.gov (United States)

    Terashima, Mikiko; Read Guernsey, Judith; Andreou, Pantelis

    2014-02-13

    Although efforts have been made to articulate rural-urban health inequalities in recent years, results have been inconsistent due to different geographical scales used in these studies. Small-area level investigations of health inequalities will likely show more detailed pictures of health inequalities among diverse rural communities, but they are difficult to conduct, particularly in a small population region. The objectives of this study were: 1) to compare life expectancy at birth for females and males across small-areas classified by locally defined settlement types for a small province in Canada; 2) to assess whether any of the settlement types explains variations in life expectancy over and above the extent of socioeconomic disadvantage and social isolation; and 3) to examine variations in life expectancies within a (larger) area unit used as the basis of health inequality investigations in previous studies. Seven settlement types were determined for the 'community' units based on population per-kilometre-road density and settlement forms. Mean life expectancies at birth for both genders were compared by settlement type, both for the entire province and within the Halifax Regional Municipality--the province's only census designated metropolitan area, but also contains rural settlements. Linear regression analyses were conducted to assess the statistical associations between life expectancy and the settlement types, adjusting for indicators of community-level deprivation. While types of communities considered as 'rural' generally had lower life expectancy for both genders, the effects of living in any settlement type were attenuated once adjusted for socioeconomic deprivation and social isolation. An exception was the village and settlement cluster type, which had additionally negative effects on health for females. There were some variations observed within the Halifax Regional Municipality, suggesting the importance of further investigating a variety of

  8. Convergence Theorem for Equilibrium and Variational Inequality Problems and a Family of Infinitely Nonexpansive Mappings in Hilbert Space

    Directory of Open Access Journals (Sweden)

    Zhou Yinying

    2014-01-01

    Full Text Available We introduce a hybrid iterative scheme for finding a common element of the set of common fixed points for a family of infinitely nonexpansive mappings, the set of solutions of the varitional inequality problem and the equilibrium problem in Hilbert space. Under suitable conditions, some strong convergence theorems are obtained. Our results improve and extend the corresponding results in (Chang et al. (2009, Min and Chang (2012, Plubtieng and Punpaeng (2007, S. Takahashi and W. Takahashi (2007, Tada and Takahashi (2007, Gang and Changsong (2009, Ying (2013, Y. Yao and J. C. Yao (2007, and Yong-Cho and Kang (2012.

  9. MO-F-304-01: Applying PDSA to a Practical Clinical Problem: Variation in Procedural Doses Among Interventional Radiologists

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. [UT MD Anderson Cancer Center (United States)

    2015-06-15

    With the current Maintenance of Certification (MOC) requirement for a practice quality improvement (PQI) project every 3 years, we all (well, most of us) find ourselves searching for projects that are both manageable and likely to have a positive impact on our clinical practice. In this session we will walk through the use of the Plan, Do, Study, Act (PDSA) cycle to address a common finding in practices where fluoroscopically guided interventions (FGI) are performed: variation in procedural doses among physicians. We will also examine strategies to secure physician support using carrots, not sticks. Learning Objectives: Review the PDSA cycle and its application to PQI. Discuss strategies for action in the example presented. Examine strategies for successful group PQI projects. A. Kyle Jones: Owner, FluoroSafety Joseph R. Steele: Consultant, FluoroSafety.

  10. MO-F-304-01: Applying PDSA to a Practical Clinical Problem: Variation in Procedural Doses Among Interventional Radiologists

    International Nuclear Information System (INIS)

    Jones, A.

    2015-01-01

    With the current Maintenance of Certification (MOC) requirement for a practice quality improvement (PQI) project every 3 years, we all (well, most of us) find ourselves searching for projects that are both manageable and likely to have a positive impact on our clinical practice. In this session we will walk through the use of the Plan, Do, Study, Act (PDSA) cycle to address a common finding in practices where fluoroscopically guided interventions (FGI) are performed: variation in procedural doses among physicians. We will also examine strategies to secure physician support using carrots, not sticks. Learning Objectives: Review the PDSA cycle and its application to PQI. Discuss strategies for action in the example presented. Examine strategies for successful group PQI projects. A. Kyle Jones: Owner, FluoroSafety Joseph R. Steele: Consultant, FluoroSafety

  11. Calculus of variations

    CERN Document Server

    Elsgolc, L E; Stark, M

    1961-01-01

    Calculus of Variations aims to provide an understanding of the basic notions and standard methods of the calculus of variations, including the direct methods of solution of the variational problems. The wide variety of applications of variational methods to different fields of mechanics and technology has made it essential for engineers to learn the fundamentals of the calculus of variations. The book begins with a discussion of the method of variation in problems with fixed boundaries. Subsequent chapters cover variational problems with movable boundaries and some other problems; sufficiency

  12. On the problem of the flux value of cosmic origin radioisotopes on the Earth and their time variations

    International Nuclear Information System (INIS)

    Styro, B.I.; Luyanas, V.Yu.; Zinkyavichyus, P.K.

    1977-01-01

    Cosmogenic radioisotopes flows on the Earth's surface are investigated. Nuclear reactions by the action of slow neutrons (cosmic rays) are analysed. It has been testified that the role of Ne, Kr, Ze and nuclei of the volcanic substance in production of cosmogenic nuclids is insignificant. Radioisotopes can provide by meteorites while passing through the atmosphere as a result of ablation. The evaluations of the meteoritic sustance falling out to the Earth can be used as a base to calculate flows of a number of radioactive isotopes. The flow density of most isotopes which come with the meteoric substance are quite insignificant. However the 26 Al flows can be of the same value as that of the rate of their production in the atmosphere. Changes of the rate of the production of cosmogenic isotopes both due to the flow variations meteoric and as a result of the cosmic ray intensity oscillations first of all effect the stratospheral reservoir. Time oscillations of cosmogenic radioisotope flows to the Earth's surface will occur with some delay because the life time of isotopes in the stratosphere lasts several years. The evaluation is given of the difference of phases between oscillations of the stratospheral rate of the formation of long-living isotopes and the flow density to the Earth's surface. It can approximate to 1-2 years

  13. Variation in Parasympathetic Dysregulation Moderates Short-term Memory Problems in Childhood Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Ward, Anthony R; Alarcón, Gabriela; Nigg, Joel T; Musser, Erica D

    2015-11-01

    Although attention deficit/hyperactivity disorder (ADHD) is associated with impairment in working memory and short-term memory, up to half of individual children with ADHD perform within a normative range. Heterogeneity in other ADHD-related mechanisms, which may compensate for or combine with cognitive weaknesses, is a likely explanation. One candidate is the robustness of parasympathetic regulation (as indexed by respiratory sinus arrhythmia; RSA). Theory and data suggest that a common neural network is likely tied to both heart-rate regulation and certain cognitive functions (including aspects of working and short-term memory). Cardiac-derived indices of parasympathetic reactivity were collected during short-term memory (STM) storage and rehearsal tasks from 243 children (116 ADHD, 127 controls). ADHD was associated with lower STM performance, replicating previous work. In addition, RSA reactivity moderated the association between STM and ADHD - both as a category and a dimension - independent of comorbidity. Specifically, conditional effects revealed that high levels of withdrawal interacted with weakened STM but high levels of augmentation moderated a positive association predicting ADHD. Thus, variations in parasympathetic reactivity may help explain neuropsychological heterogeneity in ADHD.

  14. Spectrum interpretation problems with well-type Ge(Li) detectors due to self-absorption variations

    International Nuclear Information System (INIS)

    Bruin, M. de; Korthoven, P.J.M.; Bode, P.

    1979-01-01

    For use in instrumental neutron activation analysis, a well-type Ge(Li) detector compares favourably with a comparable detector without well. It combines a good energy resolution with a relatively high detector efficiency. Moreover, this efficiency is almost independent of sample dimensions. But the use of a well-type Ge(Li) detector also has been some drawbacks, as large summation effects will result from the high detector efficiency. The least severe aspect of this summation is the additional formation of many extra sum peaks in gamma-ray spectra of nuclides with moderate or highly complex decay schemes. This leads to higher computation times, but in general, the accuracy of the analysis will not be affected. A far more important aspect of the summation is found in the fact that the intensity ratios between high energy peaks and the sum peaks of self-absorption effects, which in a flat detector is limited to only the low energy part of the spectrum, may be extended to the high energy region. This leads to sample-dependent distortion of the high energy part of the gamma-ray spectrum which may result in misinterpretation of instrumental neutron activation analysis data. The only solution to this problem seems to be to prevent the relevant low energy photons from reaching the detector. This can be accomplished by using a high Z absorber inside the detector well. (Auth.)

  15. American lookback option with fixed strike price—2-D parabolic variational inequality

    Science.gov (United States)

    Chen, Xiaoshan; Yi, Fahuai; Wang, Lihe

    In this paper we study a 2-dimensional parabolic variational inequality with financial background. We define a suitable weak formula and obtain existence and uniqueness of the problem. Moreover we analyze the behaviors of the free boundary surface.

  16. Shape Variation in the Craniomandibular System and Prevalence of Dental Problems in Domestic Rabbits: A Case Study in Evolutionary Veterinary Science

    Directory of Open Access Journals (Sweden)

    Christine Böhmer

    2017-01-01

    Full Text Available In contrast to wild lagomorphs, pet rabbits exhibit a noticeably high frequency of dental problems. Although dietary habits are considered as a major factor contributing to acquired malocclusions, the exact causes and interrelationships are still under debate. In this regard, an important aspect that has not been considered thoroughly to date is the effect of diet-induced phenotypic plasticity in skull morphology. Therefore, we conducted a geometric morphometric analysis on skull radiological images of wild and pet rabbits in order to quantify intraspecific variation in craniomandibular morphology. The statistical analyses reveal a significant morphological differentiation of the craniomandibular system between both groups. Furthermore, the analysis of covariance shows that the force-generating modules (cranium and mandible vary independently from the force-receiving module (hypselodont teeth in pet rabbits, which is in contrast to their wild relatives. Our findings suggest that the phenotypic changes in domestic rabbits impact mastication performance and, consequently, oral health. An adequate close-to-nature nutrition throughout the whole life and especially beginning early parallel to weaning (phase of increased phenotypic plasticity is necessary to ensure a normal strain on the teeth by promoting physiological lateral gliding movements and avoiding direct axial loads.

  17. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  18. Defining Quantum Control Flow

    OpenAIRE

    Ying, Mingsheng; Yu, Nengkun; Feng, Yuan

    2012-01-01

    A remarkable difference between quantum and classical programs is that the control flow of the former can be either classical or quantum. One of the key issues in the theory of quantum programming languages is defining and understanding quantum control flow. A functional language with quantum control flow was defined by Altenkirch and Grattage [\\textit{Proc. LICS'05}, pp. 249-258]. This paper extends their work, and we introduce a general quantum control structure by defining three new quantu...

  19. Can play be defined?

    DEFF Research Database (Denmark)

    Eichberg, Henning

    2015-01-01

    Can play be defined? There is reason to raise critical questions about the established academic demand that at phenomenon – also in humanist studies – should first of all be defined, i.e. de-lineated and by neat lines limited to a “little box” that can be handled. The following chapter develops....... Human beings can very well understand play – or whatever phenomenon in human life – without defining it....

  20. Preparation of initial neutronic data for fuel justification in the modes of power variation. statement of the problem and experience of practical application

    International Nuclear Information System (INIS)

    Kurakin, K.Yu.; Kozak, B.G.; Gorokhov, A.K.

    2008-01-01

    Reactor power variation causes additional thermo-mechanical loads on fuel rod clads increasing with increase in a number of loading cycles and fuel burn-up fraction. Power distribution resulted from power variation and motion of control rods is of rather complicated character that can be correctly considered only in detailed (pin-by-pin) presentation of the core neutron physics characteristics. (authors)

  1. Study of weak solutions for parabolic variational inequalities with nonstandard growth conditions.

    Science.gov (United States)

    Dong, Yan

    2018-01-01

    In this paper, we study the degenerate parabolic variational inequality problem in a bounded domain. First, the weak solutions of the variational inequality are defined. Second, the existence and uniqueness of the solutions in the weak sense are proved by using the penalty method and the reduction method.

  2. Variational collocation on finite intervals

    International Nuclear Information System (INIS)

    Amore, Paolo; Cervantes, Mayra; Fernandez, Francisco M

    2007-01-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schroedinger equation, and we have compared the performance of the present approach with others

  3. Defining Overweight and Obesity

    Science.gov (United States)

    ... Micronutrient Malnutrition State and Local Programs Defining Adult Overweight and Obesity Recommend on Facebook Tweet Share Compartir ... weight for a given height is described as overweight or obese. Body Mass Index, or BMI, is ...

  4. Drinking Levels Defined

    Science.gov (United States)

    ... of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol Exposure Support & Treatment Alcohol Policy Special ... Definition of Drinking at Low Risk for Developing Alcohol Use Disorder (AUD): For women, low-risk drinking is defined ...

  5. Defining Documentary Film

    DEFF Research Database (Denmark)

    Juel, Henrik

    2006-01-01

    A discussion of various attemts at defining documentary film regarding form, content, truth, stile, genre or reception - and a propoposal of a positive list of essential, but non-exclusive characteristica of documentary film......A discussion of various attemts at defining documentary film regarding form, content, truth, stile, genre or reception - and a propoposal of a positive list of essential, but non-exclusive characteristica of documentary film...

  6. An Integrative Approach for Defining Plinian and Sub-Plinian Eruptive Scenarios at Andesitic Volcanoes: Event-Lithostratigraphy, Eruptive Parameters and Pyroclast Textural Variations of the Largest Late-Holocene Eruptions of Mt. Taranaki, New Zealand.

    Science.gov (United States)

    Torres-Orozco, R.; Cronin, S. J.; Damaschke, M.; Kosik, S.; Pardo, N.

    2016-12-01

    Three eruptive scenarios were determined based on the event-lithostratigraphic reconstruction of the largest late-Holocene eruptions of the andesitic Mt. Taranaki, New Zealand: a) sustained dome-effusion followed by sudden stepwise collapse and unroofing of gas-rich magma; b) repeated plug and burst events generated by transient open-/closed-vent conditions; and c) open-vent conditions of more mafic magmas erupting from a satellite vent. Pyroclastic density currents (PDCs) are the most frequent outcome in every scenario. They can be produced in any/every eruption phase by formation and either repetitive-partial or total gravity-driven collapse of lava domes in the summit crater (block-and-ash flows), frequently followed by sudden magma decompression and violent, highly unsteady to quasi-steady lateral expansion (blast-like PDCs); by collapse or single-pulse fall-back of unsteady eruption columns (pyroclastic flow- and surge-type currents); or during highly unsteady and explosive hydromagmatic phases (wet surges). Fall deposits are produced during the climatic phase of each eruptive scenario by the emplacement of (i) high, sustained and steady, (ii) sustained and height-oscillating, (iii) quasi-steady and pulsating, or (iv) unsteady and totally collapsing eruption columns. Volumes, column heights and mass- and volume-eruption rates indicate that these scenarios correspond to VEI 4-5 plinian and sub-plinian multi-phase and style-shifting episodes, similar or larger than the most recent 1655 AD activity, and comparable to plinian eruptions of e.g. Apoyeque, Colima, Merapi and Tarawera volcanoes. Whole-rock chemistry, textural reconstructions and density-porosity determinations suggest that the different eruptive scenarios are mainly driven by variations in the density structure of magma in the upper conduit. Assuming a simple single conduit model, the style transitions can be explained by differing proportions of alternating gas-poor/degassed and gas-rich magma.

  7. Correlation analysis of extremely low-frequency variations of the natural electromagnetic Earth field and the problem of detecting periodical gravitational radiation

    International Nuclear Information System (INIS)

    Balakin, A.B.; Murzakhanov, Z.G.; Grunskaya, L.V.

    1994-01-01

    A proposal on the experimental detection of extremely low-frequency variations of the electromagnetic Earth field at the gravitational-wave frequency and method for correlation processing results of the experiments are described. 14 refs

  8. Fractional-Order Variational Calculus with Generalized Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Baleanu Dumitru

    2011-01-01

    Full Text Available This paper presents the necessary and sufficient optimality conditions for fractional variational problems involving the right and the left fractional integrals and fractional derivatives defined in the sense of Riemman-Liouville with a Lagrangian depending on the free end-points. To illustrate our approach, two examples are discussed in detail.

  9. Defining line replaceable units

    NARCIS (Netherlands)

    Parada Puig, J. E.; Basten, R. J I

    2015-01-01

    Defective capital assets may be quickly restored to their operational condition by replacing the item that has failed. The item that is replaced is called the Line Replaceable Unit (LRU), and the so-called LRU definition problem is the problem of deciding on which item to replace upon each type of

  10. Quantum Variational Calculus

    OpenAIRE

    Malinowska , Agnieszka B.; Torres , Delfim

    2014-01-01

    International audience; Introduces readers to the treatment of the calculus of variations with q-differences and Hahn difference operators Provides the reader with the first extended treatment of quantum variational calculus Shows how the techniques described can be applied to economic models as well as other mathematical systems This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of it...

  11. Definably compact groups definable in real closed fields. I

    OpenAIRE

    Barriga, Eliana

    2017-01-01

    We study definably compact definably connected groups definable in a sufficiently saturated real closed field $R$. We introduce the notion of group-generic point for $\\bigvee$-definable groups and show the existence of group-generic points for definably compact groups definable in a sufficiently saturated o-minimal expansion of a real closed field. We use this notion along with some properties of generic sets to prove that for every definably compact definably connected group $G$ definable in...

  12. Variational principles for locally variational forms

    International Nuclear Information System (INIS)

    Brajercik, J.; Krupka, D.

    2005-01-01

    We present the theory of higher order local variational principles in fibered manifolds, in which the fundamental global concept is a locally variational dynamical form. Any two Lepage forms, defining a local variational principle for this form, differ on intersection of their domains, by a variationally trivial form. In this sense, but in a different geometric setting, the local variational principles satisfy analogous properties as the variational functionals of the Chern-Simons type. The resulting theory of extremals and symmetries extends the first order theories of the Lagrange-Souriau form, presented by Grigore and Popp, and closed equivalents of the first order Euler-Lagrange forms of Hakova and Krupkova. Conceptually, our approach differs from Prieto, who uses the Poincare-Cartan forms, which do not have higher order global analogues

  13. Defining Game Mechanics

    DEFF Research Database (Denmark)

    Sicart (Vila), Miguel Angel

    2008-01-01

    This article defins game mechanics in relation to rules and challenges. Game mechanics are methods invoked by agents for interacting with the game world. I apply this definition to a comparative analysis of the games Rez, Every Extend Extra and Shadow of the Colossus that will show the relevance...... of a formal definition of game mechanics. Udgivelsesdato: Dec 2008...

  14. Modal Logics and Definability

    OpenAIRE

    Kuusisto, Antti

    2013-01-01

    In recent years, research into the mathematical foundations of modal logic has become increasingly popular. One of the main reasons for this is the fact that modal logic seems to adapt well to the requirements of a wide range of different fields of application. This paper is a summary of some of the author’s contributions to the understanding of modal definability theory.

  15. Software Defined Cyberinfrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Ian; Blaiszik, Ben; Chard, Kyle; Chard, Ryan

    2017-07-17

    Within and across thousands of science labs, researchers and students struggle to manage data produced in experiments, simulations, and analyses. Largely manual research data lifecycle management processes mean that much time is wasted, research results are often irreproducible, and data sharing and reuse remain rare. In response, we propose a new approach to data lifecycle management in which researchers are empowered to define the actions to be performed at individual storage systems when data are created or modified: actions such as analysis, transformation, copying, and publication. We term this approach software-defined cyberinfrastructure because users can implement powerful data management policies by deploying rules to local storage systems, much as software-defined networking allows users to configure networks by deploying rules to switches.We argue that this approach can enable a new class of responsive distributed storage infrastructure that will accelerate research innovation by allowing any researcher to associate data workflows with data sources, whether local or remote, for such purposes as data ingest, characterization, indexing, and sharing. We report on early experiments with this approach in the context of experimental science, in which a simple if-trigger-then-action (IFTA) notation is used to define rules.

  16. Defining Abnormally Low Tenders

    DEFF Research Database (Denmark)

    Ølykke, Grith Skovgaard; Nyström, Johan

    2017-01-01

    The concept of an abnormally low tender is not defined in EU public procurement law. This article takes an interdisciplinary law and economics approach to examine a dataset consisting of Swedish and Danish judgments and verdicts concerning the concept of an abnormally low tender. The purpose...

  17. Software Defined Coded Networking

    DEFF Research Database (Denmark)

    Di Paola, Carla; Roetter, Daniel Enrique Lucani; Palazzo, Sergio

    2017-01-01

    the quality of each link and even across neighbouring links and using simulations to show that an additional reduction of packet transmission in the order of 40% is possible. Second, to advocate for the use of network coding (NC) jointly with software defined networking (SDN) providing an implementation...

  18. Defining depth of anesthesia.

    Science.gov (United States)

    Shafer, S L; Stanski, D R

    2008-01-01

    In this chapter, drawn largely from the synthesis of material that we first presented in the sixth edition of Miller's Anesthesia, Chap 31 (Stanski and Shafer 2005; used by permission of the publisher), we have defined anesthetic depth as the probability of non-response to stimulation, calibrated against the strength of the stimulus, the difficulty of suppressing the response, and the drug-induced probability of non-responsiveness at defined effect site concentrations. This definition requires measurement of multiple different stimuli and responses at well-defined drug concentrations. There is no one stimulus and response measurement that will capture depth of anesthesia in a clinically or scientifically meaningful manner. The "clinical art" of anesthesia requires calibration of these observations of stimuli and responses (verbal responses, movement, tachycardia) against the dose and concentration of anesthetic drugs used to reduce the probability of response, constantly adjusting the administered dose to achieve the desired anesthetic depth. In our definition of "depth of anesthesia" we define the need for two components to create the anesthetic state: hypnosis created with drugs such as propofol or the inhalational anesthetics and analgesia created with the opioids or nitrous oxide. We demonstrate the scientific evidence that profound degrees of hypnosis in the absence of analgesia will not prevent the hemodynamic responses to profoundly noxious stimuli. Also, profound degrees of analgesia do not guarantee unconsciousness. However, the combination of hypnosis and analgesia suppresses hemodynamic response to noxious stimuli and guarantees unconsciousness.

  19. Defining and classifying syncope

    NARCIS (Netherlands)

    Thijs, Roland D.; Wieling, Wouter; Kaufmann, Horacio; van Dijk, Gert

    2004-01-01

    There is no widely adopted definition or classification of syncope and related disorders. This lack of uniformity harms patient care, research, and medical education. In this article, syncope is defined as a form of transient loss of consciousness (TLOC) due to cerebral hypoperfusion. Differences

  20. Defining Legal Moralism

    DEFF Research Database (Denmark)

    Thaysen, Jens Damgaard

    2015-01-01

    This paper discusses how legal moralism should be defined. It is argued that legal moralism should be defined as the position that “For any X, it is always a pro tanto reason for justifiably imposing legal regulation on X that X is morally wrong (where “morally wrong” is not conceptually equivalent...... to “harmful”)”. Furthermore, a distinction between six types of legal moralism is made. The six types are grouped according to whether they are concerned with the enforcement of positive or critical morality, and whether they are concerned with criminalising, legally restricting, or refraining from legally...... protecting morally wrong behaviour. This is interesting because not all types of legal moralism are equally vulnerable to the different critiques of legal moralism that have been put forth. Indeed, I show that some interesting types of legal moralism have not been criticised at all....

  1. Defining local food

    DEFF Research Database (Denmark)

    Eriksen, Safania Normann

    2013-01-01

    Despite evolving local food research, there is no consistent definition of “local food.” Various understandings are utilized, which have resulted in a diverse landscape of meaning. The main purpose of this paper is to examine how researchers within the local food systems literature define local...... food, and how these definitions can be used as a starting point to identify a new taxonomy of local food based on three domains of proximity....

  2. 9th International Symposium on the Biosafety of Genetically Modified Organisms. Session II: Identifying and defining hazards and potential consequences I: Concepts for problem formulation and non-target risk assessment.

    Science.gov (United States)

    Bigler, Franz

    2006-01-01

    The scientific organizers of the symposium put much emphasis on the identification and definition of hazard and the potential consequences thereof and three full sessions with a total of 13 presentations encompassing a wide range of related themes were planned for this topic. Unfortunately, one talk had to be cancelled because of illness of the speaker (BM Khadi, India). Some presentations covered conceptual approaches for environmental risk assessment (ERA) of GM plants (problem formulation in the risk assessment framework, familiarity approach, tiered and methodological frameworks, non-target risk assessment) and the use of models in assessing invasiveness and weediness of GM plants. Other presentations highlighted the lessons learned for future ERA from case studies and commercialized GM crops, and from monitoring of unintended releases to the environment. When the moderators of the three sessions came together after the presentations to align their summaries, there was an obvious need to restructure the 12 presentations in a way that allowed for a consistent summarizing discussion. The following new organization of the 12 talks was chosen: (1) Concepts for problem formulation and non-target risk assessment, (2) Modeling as a tool for predicting invasiveness of GM plants, (3) Case-studies of ERA of large-scale release, (4) Lessons learned for ERA from a commercialized GM plant, (5) Monitoring of unintended release of Bt maize in Mexico. The new thematic structure facilitates a more in-depth discussion of the presentations related to a specific topic, and the conclusions to be drawn are thus more consistent. Each moderator agreed to take responsibility for summarizing one or more themes and to prepare the respective report.

  3. Using the ovarian sensitivity index to define poor, normal, and high response after controlled ovarian hyperstimulation in the long gonadotropin-releasing hormone-agonist protocol: suggestions for a new principle to solve an old problem.

    Science.gov (United States)

    Huber, Malin; Hadziosmanovic, Nermin; Berglund, Lars; Holte, Jan

    2013-11-01

    To explore the utility of using the ratio between oocyte yield and total dose of FSH, i.e., the ovarian sensitivity index (OSI), to define ovarian response patterns. Retrospective cross-sectional study. University-affiliated private center. The entire unselected cohort of 7,520 IVF/intracytoplasmic sperm injection treatments (oocyte pick-ups [OPUs]) during an 8-year period (long GnRH agonist-recombinant FSH protocol). None. The distribution of the OSI (oocytes recovered × 1,000/total dose of FSH), the cutoff levels for poor and high response, set at ±1 SD, and the relationship between OSI and treatment outcome. OSI showed a log-normal distribution with cutoff levels for poor and high response at 1.697/IU and 10.07/IU, respectively. A nomogram is presented. Live-birth rates per OPU were 10.5 ± 0.1%, 26.9 ± 0.6%, and 36.0 ± 1.4% for poor, normal, and high response treatments, respectively. The predictive power (C-statistic) for OSI to predict live birth was superior to that of oocyte yield. The OSI improves the definition of ovarian response patterns because it takes into account the degree of stimulation. The nomogram presents evidence-based cutoff levels for poor, normal, and high response and could be used for unifying study designs involving ovarian response patterns. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Software defined access networks

    OpenAIRE

    Maricato, José Miguel Duarte

    2016-01-01

    With the increase of internet usage and the exponential growth of bandwidth consumption due to the increasing number of users of new generation equipments and the creation of new services that consume increasingly higher bandwidths, it's necessary to nd solutions to meet these new requirements. Passive optical networks (PONs) promise to solve these problems by providing a better service to users and providers. PON networks are very attractive since they don't depend on a...

  5. Fractional variational calculus in terms of Riesz fractional derivatives

    International Nuclear Information System (INIS)

    Agrawal, O P

    2007-01-01

    This paper presents extensions of traditional calculus of variations for systems containing Riesz fractional derivatives (RFDs). Specifically, we present generalized Euler-Lagrange equations and the transversality conditions for fractional variational problems (FVPs) defined in terms of RFDs. We consider two problems, a simple FVP and an FVP of Lagrange. Results of the first problem are extended to problems containing multiple fractional derivatives, functions and parameters, and to unspecified boundary conditions. For the second problem, we present Lagrange-type multiplier rules. For both problems, we develop the Euler-Lagrange-type necessary conditions which must be satisfied for the given functional to be extremum. Problems are considered to demonstrate applications of the formulations. Explicitly, we introduce fractional momenta, fractional Hamiltonian, fractional Hamilton equations of motion, fractional field theory and fractional optimal control. The formulations presented and the resulting equations are similar to the formulations for FVPs given in Agrawal (2002 J. Math. Anal. Appl. 272 368, 2006 J. Phys. A: Math. Gen. 39 10375) and to those that appear in the field of classical calculus of variations. These formulations are simple and can be extended to other problems in the field of fractional calculus of variations

  6. The relation between the bifactor model of the Youth Psychopathic Traits Inventory and conduct problems in adolescence: Variations across gender, ethnic background, and age.

    Science.gov (United States)

    Zwaanswijk, Wendy; Veen, Violaine C; van Geel, Mitch; Andershed, Henrik; Vedder, Paul

    2017-08-01

    The current study examines how the bifactor model of the Youth Psychopathic Traits Inventory (YPI) is related to conduct problems in a sample of Dutch adolescents (N = 2,874; 43% female). It addresses to what extent the YPI dimensions explain variance over and above a General Psychopathy factor (i.e., one factor related to all items) and how the general factor and dimensional factors are related to conduct problems. Group differences in these relations for gender, ethnic background, and age were examined. Results showed that the general factor is most important, but dimensions explain variance over and above the general factor. The general factor, and Affective and Lifestyle dimensions, of the YPI were positively related to conduct problems, whereas the Interpersonal dimension was not, after taking the general factor into account. However, across gender, ethnic background, and age, different dimensions were related to conduct problems over and above the general factor. This suggests that all 3 dimensions should be assessed when examining the psychopathy construct. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Defined contribution health benefits.

    Science.gov (United States)

    Fronstin, P

    2001-03-01

    This Issue Brief discusses the emerging issue of "defined contribution" (DC) health benefits. The term "defined contribution" is used to describe a wide variety of approaches to the provision of health benefits, all of which have in common a shift in the responsibility for payment and selection of health care services from employers to employees. DC health benefits often are mentioned in the context of enabling employers to control their outlay for health benefits by avoiding increases in health care costs. DC health benefits may also shift responsibility for choosing a health plan and the associated risks of choosing a plan from employers to employees. There are three primary reasons why some employers currently are considering some sort of DC approach. First, they are once again looking for ways to keep their health care cost increases in line with overall inflation. Second, some employers are concerned that the public "backlash" against managed care will result in new legislation, regulations, and litigation that will further increase their health care costs if they do not distance themselves from health care decisions. Third, employers have modified not only most employee benefit plans, but labor market practices in general, by giving workers more choice, control, and flexibility. DC-type health benefits have existed as cafeteria plans since the 1980s. A cafeteria plan gives each employee the opportunity to determine the allocation of his or her total compensation (within employer-defined limits) among various employee benefits (primarily retirement or health). Most types of DC health benefits currently being discussed could be provided within the existing employment-based health insurance system, with or without the use of cafeteria plans. They could also allow employees to purchase health insurance directly from insurers, or they could drive new technologies and new forms of risk pooling through which health care services are provided and financed. DC health

  8. On Defining Mass

    Science.gov (United States)

    Hecht, Eugene

    2011-01-01

    Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement surrounding the Large Hadron Collider at CERN is associated with discovering the mechanism responsible for the masses of the elementary particles. This paper will first briefly examine the leading definitions, pointing out their shortcomings. Then, utilizing relativity theory, it will propose—for consideration by the community of physicists—a conceptual definition of mass predicated on the more fundamental concept of energy, more fundamental in that everything that has mass has energy, yet not everything that has energy has mass.

  9. Implementing Software Defined Radio

    CERN Document Server

    Grayver, Eugene

    2013-01-01

    Software Defined Radio makes wireless communications easier, more efficient, and more reliable. This book bridges the gap between academic research and practical implementation. When beginning a project, practicing engineers, technical managers, and graduate students can save countless hours by considering the concepts presented in these pages. The author covers the myriad options and trade-offs available when selecting an appropriate hardware architecture. As demonstrated here, the choice between hardware- and software-centric architecture can mean the difference between meeting an aggressive schedule and bogging down in endless design iterations. Because of the author’s experience overseeing dozens of failed and successful developments, he is able to present many real-life examples. Some of the key concepts covered are: Choosing the right architecture for the market – laboratory, military, or commercial Hardware platforms – FPGAs, GPPs, specialized and hybrid devices Standardization efforts to ens...

  10. Defining cyber warfare

    Directory of Open Access Journals (Sweden)

    Dragan D. Mladenović

    2012-04-01

    Full Text Available Cyber conflicts represent a new kind of warfare that is technologically developing very rapidly. Such development results in more frequent and more intensive cyber attacks undertaken by states against adversary targets, with a wide range of diverse operations, from information operations to physical destruction of targets. Nevertheless, cyber warfare is waged through the application of the same means, techniques and methods as those used in cyber criminal, terrorism and intelligence activities. Moreover, it has a very specific nature that enables states to covertly initiate attacks against their adversaries. The starting point in defining doctrines, procedures and standards in the area of cyber warfare is determining its true nature. In this paper, a contribution to this effort was made through the analysis of the existing state doctrines and international practice in the area of cyber warfare towards the determination of its nationally acceptable definition.

  11. Defining the mobilome.

    Science.gov (United States)

    Siefert, Janet L

    2009-01-01

    This chapter defines the agents that provide for the movement of genetic material which fuels the adaptive potential of life on our planet. The chapter has been structured to be broadly comprehensive, arbitrarily categorizing the mobilome into four classes: (1) transposons, (2) plasmids, (3) bacteriophage, and (4) self-splicing molecular parasites.Our increasing understanding of the mobilome is as dynamic as the mobilome itself. With continuing discovery, it is clear that nature has not confined these genomic agents of change to neat categories, but rather the classification categories overlap and intertwine. Massive sequencing efforts and their published analyses are continuing to refine our understanding of the extent of the mobilome. This chapter provides a framework to describe our current understanding of the mobilome and a foundation on which appreciation of its impact on genome evolution can be understood.

  12. Software Defined Networking

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius

    Network Service Providers (NSP) often choose to overprovision their networks instead of deploying proper Quality of Services (QoS) mechanisms that allow for traffic differentiation and predictable quality. This tendency of overprovisioning is not sustainable for the simple reason that network...... resources are limited. Hence, to counteract this trend, current QoS mechanisms must become simpler to deploy and operate, in order to motivate NSPs to employ QoS techniques instead of overprovisioning. Software Defined Networking (SDN) represents a paradigm shift in the way telecommunication and data...... generic perspective (e.g. service provisioning speed, resources availability). As a result, new mechanisms for providing QoS are proposed, solutions for SDN-specific QoS challenges are designed and tested, and new network management concepts are prototyped, all aiming to improve QoS for network services...

  13. General quantum variational calculus

    Directory of Open Access Journals (Sweden)

    Artur M. C. Brito da Cruz

    2018-02-01

    Full Text Available We develop a new variational calculus based in the general quantum difference operator recently introduced by Hamza et al. In particular, we obtain optimality conditions for generalized variational problems where the Lagrangian may depend on the endpoints conditions and a real parameter, for the basic and isoperimetric problems, with and without fixed boundary conditions. Our results provide a generalization to previous results obtained for the $q$- and Hahn-calculus.

  14. Defining the Anthropocene

    Science.gov (United States)

    Lewis, Simon; Maslin, Mark

    2016-04-01

    Time is divided by geologists according to marked shifts in Earth's state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Should the Anthropocene - the idea that human activity is a force acting upon the Earth system in ways that mean that Earth will be altered for millions of years - be defined as a geological time-unit at the level of an Epoch? Here we appraise the data to assess such claims, first in terms of changes to the Earth system, with particular focus on very long-lived impacts, as Epochs typically last millions of years. Can Earth really be said to be in transition from one state to another? Secondly, we then consider the formal criteria used to define geological time-units and move forward through time examining whether currently available evidence passes typical geological time-unit evidence thresholds. We suggest two time periods likely fit the criteria (1) the aftermath of the interlinking of the Old and New Worlds, which moved species across continents and ocean basins worldwide, a geologically unprecedented and permanent change, which is also the globally synchronous coolest part of the Little Ice Age (in Earth system terms), and the beginning of global trade and a new socio-economic "world system" (in historical terms), marked as a golden spike by a temporary drop in atmospheric CO2, centred on 1610 CE; and (2) the aftermath of the Second World War, when many global environmental changes accelerated and novel long-lived materials were increasingly manufactured, known as the Great Acceleration (in Earth system terms) and the beginning of the Cold War (in historical terms), marked as a golden spike by the peak in radionuclide fallout in 1964. We finish by noting that the Anthropocene debate is politically loaded, thus transparency in the presentation of evidence is essential if a formal definition of the Anthropocene is to avoid becoming a debate about bias. The

  15. Defining Information Security.

    Science.gov (United States)

    Lundgren, Björn; Möller, Niklas

    2017-11-15

    This article proposes a new definition of information security, the 'Appropriate Access' definition. Apart from providing the basic criteria for a definition-correct demarcation and meaning concerning the state of security-it also aims at being a definition suitable for any information security perspective. As such, it bridges the conceptual divide between so-called 'soft issues' of information security (those including, e.g., humans, organizations, culture, ethics, policies, and law) and more technical issues. Because of this it is also suitable for various analytical purposes, such as analysing possible security breaches, or for studying conflicting attitudes on security in an organization. The need for a new definition is demonstrated by pointing to a number of problems for the standard definition type of information security-the so-called CIA definition. Besides being too broad as well as too narrow, it cannot properly handle the soft issues of information security, nor recognize the contextual and normative nature of security.

  16. Teleology and Defining Sex.

    Science.gov (United States)

    Gamble, Nathan K; Pruski, Michal

    2018-07-01

    Disorders of sexual differentiation lead to what is often referred to as an intersex state. This state has medical, as well as some legal, recognition. Nevertheless, the question remains whether intersex persons occupy a state in between maleness and femaleness or whether they are truly men or women. To answer this question, another important conundrum needs to be first solved: what defines sex? The answer seems rather simple to most people, yet when morphology does not coincide with haplotypes, and genetics might not correlate with physiology the issue becomes more complex. This paper tackles both issues by establishing where the essence of sex is located and by superimposing that framework onto the issue of the intersex. This is achieved through giving due consideration to the biology of sexual development, as well as through the use of a teleological framework of the meaning of sex. Using a range of examples, the paper establishes that sex cannot be pinpointed to one biological variable but is rather determined by how the totality of one's biology is oriented towards biological reproduction. A brief consideration is also given to the way this situation could be comprehended from a Christian understanding of sex and suffering.

  17. A Variational Reduction and the Existence of a Fully Localised Solitary Wave for the Three-Dimensional Water-Wave Problem with Weak Surface Tension

    Science.gov (United States)

    Buffoni, Boris; Groves, Mark D.; Wahlén, Erik

    2018-06-01

    Fully localised solitary waves are travelling-wave solutions of the three- dimensional gravity-capillary water wave problem which decay to zero in every horizontal spatial direction. Their existence has been predicted on the basis of numerical simulations and model equations (in which context they are usually referred to as `lumps'), and a mathematically rigorous existence theory for strong surface tension (Bond number {β} greater than {1/3}) has recently been given. In this article we present an existence theory for the physically more realistic case {0 point of the reduced functional is found by minimising it over its natural constraint set.

  18. Complementarity problems

    CERN Document Server

    Isac, George

    1992-01-01

    The study of complementarity problems is now an interesting mathematical subject with many applications in optimization, game theory, stochastic optimal control, engineering, economics etc. This subject has deep relations with important domains of fundamental mathematics such as fixed point theory, ordered spaces, nonlinear analysis, topological degree, the study of variational inequalities and also with mathematical modeling and numerical analysis. Researchers and graduate students interested in mathematical modeling or nonlinear analysis will find here interesting and fascinating results.

  19. Defining an emerging disease.

    Science.gov (United States)

    Moutou, F; Pastoret, P-P

    2015-04-01

    Defining an emerging disease is not straightforward, as there are several different types of disease emergence. For example, there can be a 'real' emergence of a brand new disease, such as the emergence of bovine spongiform encephalopathy in the 1980s, or a geographic emergence in an area not previously affected, such as the emergence of bluetongue in northern Europe in 2006. In addition, disease can emerge in species formerly not considered affected, e.g. the emergence of bovine tuberculosis in wildlife species since 2000 in France. There can also be an unexpected increase of disease incidence in a known area and a known species, or there may simply be an increase in our knowledge or awareness of a particular disease. What all these emerging diseases have in common is that human activity frequently has a role to play in their emergence. For example, bovine spongiform encephalopathy very probably emerged as a result of changes in the manufacturing of meat-and-bone meal, bluetongue was able to spread to cooler climes as a result of uncontrolled trade in animals, and a relaxation of screening and surveillance for bovine tuberculosis enabled the disease to re-emerge in areas that had been able to drastically reduce the number of cases. Globalisation and population growth will continue to affect the epidemiology of diseases in years to come and ecosystems will continue to evolve. Furthermore, new technologies such as metagenomics and high-throughput sequencing are identifying new microorganisms all the time. Change is the one constant, and diseases will continue to emerge, and we must consider the causes and different types of emergence as we deal with these diseases in the future.

  20. 143Nd/144Nd and 87Sr/86Sr isotope ratio variations in magmatic rocks of Aleutian island arc as regard to the problem of their petrogenesis

    International Nuclear Information System (INIS)

    Zhuravlev, D.Z.; Chernyshev, I.V.; Tsvetkov, A.A.; Borsuk, A.M.; Agapova, A.A.; Serdyuk, N.I.

    1983-01-01

    The results of precision measurement of isotope composition of neodymium in rocks of Pre-Quaternary magmatic formations of the Aleutian island arc (AIA) (Commander Islands). It has been found summing the Nd and Sr analysis results in AIA magmatic rocks that AIA magmatic melts are of mantle origin. The AIA magma source the full its length off and for all the history of geological development remained isotopically homogeneousm Crust contamination of magmatic melts played a significant role only in the initial and early stages of the AIA development, in the later and conclusive stages this process has been sharply reduced. Sedimentary material practically did not take part in the magmaproduction process at the initial stage of the AIA development, it is hardly probable that its role increased at the later stages. The cause of important 87 Sr/ 86 Sr ratio variations in the rocks of one AIA petrographic type is the propylitization process with participation of sea water. Variance of 87 Sr/ 86 Sr ratios without taking into account other isotope systems data is not an indisputable proof of magma source heterogeneity

  1. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  2. Definably compact groups definable in real closed fields.II

    OpenAIRE

    Barriga, Eliana

    2017-01-01

    We continue the analysis of definably compact groups definable in a real closed field $\\mathcal{R}$. In [3], we proved that for every definably compact definably connected semialgebraic group $G$ over $\\mathcal{R}$ there are a connected $R$-algebraic group $H$, a definable injective map $\\phi$ from a generic definable neighborhood of the identity of $G$ into the group $H\\left(R\\right)$ of $R$-points of $H$ such that $\\phi$ acts as a group homomorphism inside its domain. The above result and o...

  3. Minimizers with discontinuous velocities for the electromagnetic variational method

    International Nuclear Information System (INIS)

    De Luca, Jayme

    2010-01-01

    The electromagnetic two-body problem has neutral differential delay equations of motion that, for generic boundary data, can have solutions with discontinuous derivatives. If one wants to use these neutral differential delay equations with arbitrary boundary data, solutions with discontinuous derivatives must be expected and allowed. Surprisingly, Wheeler-Feynman electrodynamics has a boundary value variational method for which minimizer trajectories with discontinuous derivatives are also expected, as we show here. The variational method defines continuous trajectories with piecewise defined velocities and accelerations, and electromagnetic fields defined by the Euler-Lagrange equations on trajectory points. Here we use the piecewise defined minimizers with the Lienard-Wierchert formulas to define generalized electromagnetic fields almost everywhere (but on sets of points of zero measure where the advanced/retarded velocities and/or accelerations are discontinuous). Along with this generalization we formulate the generalized absorber hypothesis that the far fields vanish asymptotically almost everywhere and show that localized orbits with far fields vanishing almost everywhere must have discontinuous velocities on sewing chains of breaking points. We give the general solution for localized orbits with vanishing far fields by solving a (linear) neutral differential delay equation for these far fields. We discuss the physics of orbits with discontinuous derivatives stressing the differences to the variational methods of classical mechanics and the existence of a spinorial four-current associated with the generalized variational electrodynamics.

  4. A New Accreditation Problem: Defining the Liberal Arts and Sciences.

    Science.gov (United States)

    Hoskins, Robert L.

    In 1985, the Accrediting Council on Education in Journalism and Mass Communications (ACEJMC) adopted a standard requiring that journalism/mass communications students take a minimum of 90 semester hours in courses outside their major, with at least 65 hours in liberal arts and sciences. The term "liberal arts" defies precise definition,…

  5. Problems and Progress in Defining Terrorism in International Law

    Directory of Open Access Journals (Sweden)

    Ridarson Galingging

    2012-02-01

    Full Text Available There is an effort to adopt an internationally-accepted legal definition for ‘terrorism’ since such definition will enhance international cooperation in fighting terrorism, which at the moment is fragmented and ineffective. However, various obstacles e.g. political heterogeneity or ideological discrepancy arise when seeking a uniformed definition of terrorism, hence this study. Dunia internasional berupaya untuk menetapkan definisi legal ‘terorisme’ yang diterima secara umum karena definisi ini dapat meningkatkan kerjasama internasional dalam melawan terorisme yang saat ini masih terkotak-kotak dan tidak efektif. Tulisan ini membahas pelbagai kesulitan yang muncul dalam upaya mencari definisi tersebut, seperti masalah keragaman politik dan kesenjangan ideologi antarnegara.

  6. Conversations with Technical Writing Teachers: Defining a Problem.

    Science.gov (United States)

    Selting, Bonita R.

    2002-01-01

    Considers if teaching technology is problematic for technical writing instructors. Presents ideas of 64 Association of Teachers of Technical Writing (ATTW) members who were queried on their roles as teachers of technical writing in relation to the demands made upon them to also be teachers of technology skills. Concludes with a call for more…

  7. Ranking Reproductive Health Problems to Define Service Priorities ...

    African Journals Online (AJOL)

    Le classement des problèmes de la santé reproductive afin de définir les priorités des services. Le Rapport du Développement Mondial de 1993 a proposé un nouveau paradigme à l'établissement des priorités dans les services de santé. Les deux démarches importantes par rapport à cette approche sont les estimations ...

  8. Violence on Campus: Defining the Problems, Strategies for Action.

    Science.gov (United States)

    Hoffman, Allan M., Ed.; Schuh, John H., Ed.; Fenske, Robert H., Ed.

    This book addresses issues in dealing with campus violence, including types of violence on campuses, trends in campus violence, effects of increasing concerns about campus violence, and appropriate actions by student affairs and academic administrators to ensure campus safety. The chapters are: (1) "Violent Crime in American Society" (Fernando M.…

  9. Knapsack problems

    CERN Document Server

    Kellerer, Hans; Pisinger, David

    2004-01-01

    Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num­ ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...

  10. Obstacle problems in mathematical physics

    CERN Document Server

    Rodrigues, J-F

    1987-01-01

    The aim of this research monograph is to present a general account of the applicability of elliptic variational inequalities to the important class of free boundary problems of obstacle type from a unifying point of view of classical Mathematical Physics.The first part of the volume introduces some obstacle type problems which can be reduced to variational inequalities. Part II presents some of the main aspects of the theory of elliptic variational inequalities, from the abstract hilbertian framework to the smoothness of the variational solution, discussing in general the properties of the free boundary and including some results on the obstacle Plateau problem. The last part examines the application to free boundary problems, namely the lubrication-cavitation problem, the elastoplastic problem, the Signorini (or the boundary obstacle) problem, the dam problem, the continuous casting problem, the electrochemical machining problem and the problem of the flow with wake in a channel past a profile.

  11. Variations in government contract in Malaysia

    Directory of Open Access Journals (Sweden)

    Jaspal Singh Nachatar

    2010-12-01

    Full Text Available The complexity of construction works means that it is hardly possible to complete a project without changes to the plans or the construction process itself. There can only be a minority of contracts of any size in which the subject matter when completed is identical in every respect with what was contemplated at the outset. As such, variations are inevitable in even the best-planned contracts. This study is attempted to examine the ways a variation was formed in law and project, in finding out whether the Standard Form of Contract used in Malaysia particularly the government Public Works Department (PWD form has been utilized to the best level in variation cases. Additionally, this study examined the benefits of variations to parties in contract and also provides suggestions and assumptions in an effort to contribute solutions to issues and problem detected. The research methodology used in this study was an extensive review of relevant literature, case study, empirical questionnaires and structured interviews and general observations based on experience and surroundings. The academic study approach incorporated stages such as initial understanding, data and information gathering, analysis of data, findings and conclusion and general suggestions in the study. The major findings of this study, among others, revealed that the existences of variations are common in projects. The main cause of variations was due to client request because of inadequate project objectives for the designer to develop comprehensive design. Besides, the analysis pointed out that the government form of contract the Public Works Department (PWD 203/203A can help in overcoming projects with variation because of the clear defined procedure. This study also found that proper planning and coordination at tender stage can minimize the risk of ‘unwanted’ variations. In conclusion, this study recommended that future research should be done in design and build based contract

  12. 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.

  13. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  14. Improving network management with Software Defined Networking

    International Nuclear Information System (INIS)

    Dzhunev, Pavel

    2013-01-01

    Software-defined networking (SDN) is developed as an alternative to closed networks in centers for data processing by providing a means to separate the control layer data layer switches, and routers. SDN introduces new possibilities for network management and configuration methods. In this article, we identify problems with the current state-of-the-art network configuration and management mechanisms and introduce mechanisms to improve various aspects of network management

  15. Academic Departments: Problems, Variations, and Alternatives.

    Science.gov (United States)

    McHenry, Dean E.; And Others

    Do academic departments promote scholarship, protect higher learning from stagnation and interference, and provide a sound basis for hiring and advancing faculty? Or do they stifle teaching and research, foster parochialism, and limit the development of professors and students? There exist operating alternatives to conventional departments. Those…

  16. Variational problems with obstacles and harmonic maps

    International Nuclear Information System (INIS)

    Musina, R.

    1990-08-01

    Our first purpose is to find a generalization of the usual definition of a harmonic map between two Riemannian manifolds in order to consider less regular target spaces. Our second aim was to extend a result by Chen and Struwe about the heat flow of harmonic mappings into manifolds with boundary. 19 refs

  17. How Should Energy Be Defined Throughout Schooling?

    Science.gov (United States)

    Bächtold, Manuel

    2017-02-01

    The question of how to teach energy has been renewed by recent studies focusing on the learning and teaching progressions for this concept. In this context, one question has been, for the most part, overlooked: how should energy be defined throughout schooling? This paper addresses this question in three steps. We first identify and discuss two main approaches in physics concerning the definition of energy, one claiming there is no satisfactory definition and taking conservation as a fundamental property, and the other based on Rankine's definition of energy as the capacity of a system to produce changes. We then present a study concerning how energy is actually defined throughout schooling in the case of France by analyzing national programs, physics textbooks, and the answers of teachers to a questionnaire. This study brings to light a consistency problem in the way energy is defined across school years: in primary school, an adapted version of Rankine's definition is introduced and conservation is ignored; in high school, conservation is introduced and Rankine's definition is ignored. Finally, we address this consistency problem by discussing possible teaching progressions. We argue in favor of the use of Rankine's definition throughout schooling: at primary school, it is a possible substitute to students' erroneous conceptions; at secondary school, it might help students become aware of the unifying role of energy and thereby overcome the compartmentalization problem.

  18. Variational and quasi-variational inequalities in mechanics

    CERN Document Server

    Kravchuk, Alexander S

    2007-01-01

    The essential aim of the present book is to consider a wide set of problems arising in the mathematical modelling of mechanical systems under unilateral constraints. In these investigations elastic and non-elastic deformations, friction and adhesion phenomena are taken into account. All the necessary mathematical tools are given: local boundary value problem formulations, construction of variational equations and inequalities, and the transition to minimization problems, existence and uniqueness theorems, and variational transformations (Friedrichs and Young-Fenchel-Moreau) to dual and saddle-point search problems. Important new results concern contact problems with friction. The Coulomb friction law and some others are considered, in which relative sliding velocities appear. The corresponding quasi-variational inequality is constructed, as well as the appropriate iterative method for its solution. Outlines of the variational approach to non-stationary and dissipative systems and to the construction of the go...

  19. Selection problems and objectives in mutation breeding

    International Nuclear Information System (INIS)

    Mac Key, J.

    1984-01-01

    In plant breeding, major genes are preferably handled by inbreeding, back-crosses and selection through the family/pedigree method. Polygenic systems need gene accumulation, i.e. handling in bulk allowing natural/recurrent selection to operate. The two types of genetic control normally occur together irrespective of whether the variation is created by crossing or by mutagenesis. Cross-breeding can conveniently work with both types of variation and offers a range of genetic backgrounds. Problems are the often enormous recombination potential risking the break-down of already accomplished genic constellations or undesirable linkages. Mutation induction implies a scattered mono- to oligo-factorial variation mostly functioning as a negative load. As a result, it will be difficult and unrealistic to try to explore micromutations, as defined by Gaul, in vegetatively propagated and autogamous crop plants. Quantitative analyses have not been able to give guidance since the induced variation includes disturbed vitality and main or side-effects of events that are possible to define as macro-mutations. The possibility of better exhausting the variation induced will mainly depend on the precision in selection techniques, i.e. by dividing complex traits into their components, by improving environmental conditions for selection, and/or by sharpening the screening technique. Contrary to recombination breeding, mutation-induced variation does not fit a plan encompassing overall agronomic traits simultaneously. The progress has to go step by step. Thus, even more than in cross-breeding, it is important that accurately outlined objectives be set. Some characters, such as flower colour, can easily be defined while others, such as yield, may be more interdependent, calling for compromises difficult to foresee. The complexity of the latter category of traits is illustrated by the interaction pattern in relation to grain yield in cereals where both shoot and root are considered

  20. Defining asthma in genetic studies

    NARCIS (Netherlands)

    Koppelman, GH; Postma, DS; Meijer, G.

    1999-01-01

    Genetic studies have been hampered by the lack of a gold standard to diagnose asthma. The complex nature of asthma makes it more difficult to identify asthma genes. Therefore, approaches to define phenotypes, which have been successful in other genetically complex diseases, may be applied to define

  1. Variation and Linguistic Theory.

    Science.gov (United States)

    Bailey, Charles-James N.

    This volume presents principles and models for describing language variation, and introduces a time-based, dynamic framework for linguistic description. The book first summarizes some of the problems of grammatical description encountered from Saussure through the present and then outlines possibilities for new descriptions of language which take…

  2. Quantum variational calculus

    CERN Document Server

    Malinowska, Agnieszka B

    2014-01-01

    This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of its results is that they are able to deal with nondifferentiable (even discontinuous) functions, which are important in applications. Possible applications in economics are discussed. Economists model time as continuous or discrete. Although individual economic decisions are generally made at discrete time intervals, they may well be less than perfectly synchronized in ways discrete models postulate. On the other hand, the usual assumption that economic activity takes place continuously, is nothing else than a convenient abstraction that in many applications is far from reality. The Hahn quantum calculus helps to bridge the gap between the two families of models: continuous and discrete. Quantum Variational Calculus is self-contained and unified in presentation. It provides an opportunity for an introduction to the quantum calculus of variations fo...

  3. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  4. Variational submanifolds of Euclidean spaces

    Science.gov (United States)

    Krupka, D.; Urban, Z.; Volná, J.

    2018-03-01

    Systems of ordinary differential equations (or dynamical forms in Lagrangian mechanics), induced by embeddings of smooth fibered manifolds over one-dimensional basis, are considered in the class of variational equations. For a given non-variational system, conditions assuring variationality (the Helmholtz conditions) of the induced system with respect to a submanifold of a Euclidean space are studied, and the problem of existence of these "variational submanifolds" is formulated in general and solved for second-order systems. The variational sequence theory on sheaves of differential forms is employed as a main tool for the analysis of local and global aspects (variationality and variational triviality). The theory is illustrated by examples of holonomic constraints (submanifolds of a configuration Euclidean space) which are variational submanifolds in geometry and mechanics.

  5. Introduction to global variational geometry

    CERN Document Server

    Krupka, Demeter

    2015-01-01

    The book is devoted to recent research in the global variational theory on smooth manifolds. Its main objective is an extension of the classical variational calculus on Euclidean spaces to (topologically nontrivial) finite-dimensional smooth manifolds; to this purpose the methods of global analysis of differential forms are used. Emphasis is placed on the foundations of the theory of variational functionals on fibered manifolds - relevant geometric structures for variational principles in geometry, physical field theory and higher-order fibered mechanics. The book chapters include: - foundations of jet bundles and analysis of differential forms and vector fields on jet bundles, - the theory of higher-order integral variational functionals for sections of a fibred space, the (global) first variational formula in infinitesimal and integral forms- extremal conditions and the discussion of Noether symmetries and generalizations,- the inverse problems of the calculus of variations of Helmholtz type- variational se...

  6. Theoretical approaches to elections defining

    OpenAIRE

    Natalya V. Lebedeva

    2011-01-01

    Theoretical approaches to elections defining develop the nature, essence and content of elections, help to determine their place and a role as one of the major national law institutions in democratic system.

  7. Theoretical approaches to elections defining

    Directory of Open Access Journals (Sweden)

    Natalya V. Lebedeva

    2011-01-01

    Full Text Available Theoretical approaches to elections defining develop the nature, essence and content of elections, help to determine their place and a role as one of the major national law institutions in democratic system.

  8. Environmental variation partitioned into separate heritable components

    DEFF Research Database (Denmark)

    Ørsted, Michael; Rohde, Palle Duun; Hoffmann, Ary A

    2018-01-01

    Trait variation is normally separated into genetic and environmental components, yet genetic factors also control the expression of environmental variation, encompassing plasticity across environmental gradients and within-environment responses. We defined four components of environmental variation......: plasticity across environments, variability in plasticity, variation within environments, and differences in within-environment variation across environments. We assessed these components for cold tolerance across five rearing temperatures using the Drosophila melanogaster Genetic Reference Panel (DGRP...

  9. Defining Modules, Modularity and Modularization

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth; Pedersen, Per Erik Elgård

    The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization.......The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization....

  10. Nonclassical Problem for Ultraparabolic Equation in Abstract Spaces

    Directory of Open Access Journals (Sweden)

    Gia Avalishvili

    2016-01-01

    Full Text Available Nonclassical problem for ultraparabolic equation with nonlocal initial condition with respect to one time variable is studied in abstract Hilbert spaces. We define the space of square integrable vector-functions with values in Hilbert spaces corresponding to the variational formulation of the nonlocal problem for ultraparabolic equation and prove trace theorem, which allows one to interpret initial conditions of the nonlocal problem. We obtain suitable a priori estimates and prove the existence and uniqueness of solution of the nonclassical problem and continuous dependence upon the data of the solution to the nonlocal problem. We consider an application of the obtained abstract results to nonlocal problem for ultraparabolic partial differential equation with second-order elliptic operator and obtain well-posedness result in Sobolev spaces.

  11. Defining functional distances over Gene Ontology

    Directory of Open Access Journals (Sweden)

    del Pozo Angela

    2008-01-01

    Full Text Available Abstract Background A fundamental problem when trying to define the functional relationships between proteins is the difficulty in quantifying functional similarities, even when well-structured ontologies exist regarding the activity of proteins (i.e. 'gene ontology' -GO-. However, functional metrics can overcome the problems in the comparing and evaluating functional assignments and predictions. As a reference of proximity, previous approaches to compare GO terms considered linkage in terms of ontology weighted by a probability distribution that balances the non-uniform 'richness' of different parts of the Direct Acyclic Graph. Here, we have followed a different approach to quantify functional similarities between GO terms. Results We propose a new method to derive 'functional distances' between GO terms that is based on the simultaneous occurrence of terms in the same set of Interpro entries, instead of relying on the structure of the GO. The coincidence of GO terms reveals natural biological links between the GO functions and defines a distance model Df which fulfils the properties of a Metric Space. The distances obtained in this way can be represented as a hierarchical 'Functional Tree'. Conclusion The method proposed provides a new definition of distance that enables the similarity between GO terms to be quantified. Additionally, the 'Functional Tree' defines groups with biological meaning enhancing its utility for protein function comparison and prediction. Finally, this approach could be for function-based protein searches in databases, and for analysing the gene clusters produced by DNA array experiments.

  12. Radiation Tolerant Software Defined Video Processor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — MaXentric's is proposing a radiation tolerant Software Define Video Processor, codenamed SDVP, for the problem of advanced motion imaging in the space environment....

  13. Conformable variational iteration method

    Directory of Open Access Journals (Sweden)

    Omer Acan

    2017-02-01

    Full Text Available In this study, we introduce the conformable variational iteration method based on new defined fractional derivative called conformable fractional derivative. This new method is applied two fractional order ordinary differential equations. To see how the solutions of this method, linear homogeneous and non-linear non-homogeneous fractional ordinary differential equations are selected. Obtained results are compared the exact solutions and their graphics are plotted to demonstrate efficiency and accuracy of the method.

  14. Islamic Education Research Problem

    Directory of Open Access Journals (Sweden)

    Abdul Muthalib

    2012-04-01

    Full Text Available This paper will discuss Islamic educational studies that is reviewing how to find, limit and define problems and problem-solving concepts. The central question of this paper is to describe how to solve the problem in Islamic educational research. A researcher or educator who has the knowledge, expertise, or special interest on education for example is usually having a sensitivity to issues relating to educational research. In the research dimension of religious education, there are three types of problems, namely: Problems foundation, structural problems and operational issues. In doing research in Islamic education someone should understand research problem, limiting and formulating the problem, how to solve the problem, other problem relating to the point of research, and research approach.

  15. On vector equilibrium problem

    Indian Academy of Sciences (India)

    [G] Giannessi F, Theorems of alternative, quadratic programs and complementarity problems, in: Variational Inequalities and Complementarity Problems (eds) R W Cottle, F Giannessi and J L Lions (New York: Wiley) (1980) pp. 151±186. [K1] Kazmi K R, Existence of solutions for vector optimization, Appl. Math. Lett. 9 (1996).

  16. Control of System with Defined Risk Level

    Directory of Open Access Journals (Sweden)

    Pavol Tomasov

    2002-01-01

    Full Text Available In the following paper the basic requirements for system control with defined risk level is presented. The paper should be an introduction to describe of theoretical apparatus, which was created during some years of research work in the Department of information and safety systems in this area. It a modification or creation of new parts of Information theory, System theory, and Control theory means. This parts are necessary for the analysis and synthesis tasks in the systems where dominant attribute of control is defined risk level. The basic problem is the creation of protect mechanism again the threats from inside and from controlled system environs. For each risk reduction mechanism is needed some redundancy which should be into control algorithm to put by exactly determined way.

  17. Variational inference & deep learning : A new synthesis

    NARCIS (Netherlands)

    Kingma, D.P.

    2017-01-01

    In this thesis, Variational Inference and Deep Learning: A New Synthesis, we propose novel solutions to the problems of variational (Bayesian) inference, generative modeling, representation learning, semi-supervised learning, and stochastic optimization.

  18. Variational inference & deep learning: A new synthesis

    OpenAIRE

    Kingma, D.P.

    2017-01-01

    In this thesis, Variational Inference and Deep Learning: A New Synthesis, we propose novel solutions to the problems of variational (Bayesian) inference, generative modeling, representation learning, semi-supervised learning, and stochastic optimization.

  19. Defining Plagiarism: A Literature Review

    Directory of Open Access Journals (Sweden)

    Akbar Akbar

    2018-02-01

    Full Text Available Plagiarism has repeatedly occurred in Indonesia, resulting in focusing on such academic misbehavior as a “central issue” in Indonesian higher education. One of the issues of addressing plagiarism in higher education is that there is a confusion of defining plagiarism. It seems that Indonesian academics had different perception when defining plagiarism. This article aims at exploring the issue of plagiarism by helping define plagiarism to address confusion among Indonesian academics. This article applies literature review by firs finding relevant articles after identifying databases for literature searching. After the collection of required articles for review, the articles were synthesized before presenting the findings. This study has explored the definition of plagiarism in the context of higher education. This research found that plagiarism is defined in the relation of criminal acts. The huge numbers of discursive features used position plagiaristic acts as an illegal deed. This study also found that cultural backgrounds and exposure to plagiarism were influential in defining plagiarism.

  20. Modular Software-Defined Radio

    Directory of Open Access Journals (Sweden)

    Rhiemeier Arnd-Ragnar

    2005-01-01

    Full Text Available In view of the technical and commercial boundary conditions for software-defined radio (SDR, it is suggestive to reconsider the concept anew from an unconventional point of view. The organizational principles of signal processing (rather than the signal processing algorithms themselves are the main focus of this work on modular software-defined radio. Modularity and flexibility are just two key characteristics of the SDR environment which extend smoothly into the modeling of hardware and software. In particular, the proposed model of signal processing software includes irregular, connected, directed, acyclic graphs with random node weights and random edges. Several approaches for mapping such software to a given hardware are discussed. Taking into account previous findings as well as new results from system simulations presented here, the paper finally concludes with the utility of pipelining as a general design guideline for modular software-defined radio.

  1. Defining and Selecting Independent Directors

    Directory of Open Access Journals (Sweden)

    Eric Pichet

    2017-10-01

    Full Text Available Drawing from the Enlightened Shareholder Theory that the author first developed in 2011, this theoretical paper with practical and normative ambitions achieves a better definition of independent director, while improving the understanding of the roles he fulfils on boards of directors. The first part defines constructs like firms, Governance system and Corporate governance, offering a clear distinction between the latter two concepts before explaining the four main missions of a board. The second part defines the ideal independent director by outlining the objective qualities that are necessary and adding those subjective aspects that have turned this into a veritable profession. The third part defines the ideal process for selecting independent directors, based on nominating committees that should themselves be independent. It also includes ways of assessing directors who are currently in function, as well as modalities for renewing their mandates. The paper’s conclusion presents the Paradox of the Independent Director.

  2. Defining and Classifying Interest Groups

    DEFF Research Database (Denmark)

    Baroni, Laura; Carroll, Brendan; Chalmers, Adam

    2014-01-01

    The interest group concept is defined in many different ways in the existing literature and a range of different classification schemes are employed. This complicates comparisons between different studies and their findings. One of the important tasks faced by interest group scholars engaged...... in large-N studies is therefore to define the concept of an interest group and to determine which classification scheme to use for different group types. After reviewing the existing literature, this article sets out to compare different approaches to defining and classifying interest groups with a sample...... in the organizational attributes of specific interest group types. As expected, our comparison of coding schemes reveals a closer link between group attributes and group type in narrower classification schemes based on group organizational characteristics than those based on a behavioral definition of lobbying....

  3. Software Defined Radio: Basic Principles and Applications

    Directory of Open Access Journals (Sweden)

    José Raúl Machado-Fernández

    2014-12-01

    Full Text Available The author makes a review of the SDR (Software Defined Radio technology, including hardware schemes and application fields. A low performance device is presented and several tests are executed with it using free software. With the acquired experience, SDR employment opportunities are identified for low-cost solutions that can solve significant problems. In addition, a list of the most important frameworks related to the technology developed in the last years is offered, recommending the use of three of them.

  4. Defining the Strategy of Nuclear Activity

    International Nuclear Information System (INIS)

    Racana, R.

    2006-01-01

    This article presents nuclear activity as defined within the field of the nuclear industry, which is studied from its capacity to generate electric power to its application in industry and medicine as well as a source for weapons of mass destruction. These fields of analysis introduce some problems that the nuclear activity itself must know how to confront employing action strategies aimed at becoming an activity to be kept in mind when making use of the benefits that its peaceful use contributes to human life. (Author)

  5. Software defined networking applications in distributed datacenters

    CERN Document Server

    Qi, Heng

    2016-01-01

    This SpringerBrief provides essential insights on the SDN application designing and deployment in distributed datacenters. In this book, three key problems are discussed: SDN application designing, SDN deployment and SDN management. This book demonstrates how to design the SDN-based request allocation application in distributed datacenters. It also presents solutions for SDN controller placement to deploy SDN in distributed datacenters. Finally, an SDN management system is proposed to guarantee the performance of datacenter networks which are covered and controlled by many heterogeneous controllers. Researchers and practitioners alike will find this book a valuable resource for further study on Software Defined Networking. .

  6. Perturbed asymptotically linear problems

    OpenAIRE

    Bartolo, R.; Candela, A. M.; Salvatore, A.

    2012-01-01

    The aim of this paper is investigating the existence of solutions of some semilinear elliptic problems on open bounded domains when the nonlinearity is subcritical and asymptotically linear at infinity and there is a perturbation term which is just continuous. Also in the case when the problem has not a variational structure, suitable procedures and estimates allow us to prove that the number of distinct crtitical levels of the functional associated to the unperturbed problem is "stable" unde...

  7. ON DEFINING S-SPACES

    Directory of Open Access Journals (Sweden)

    Francesco Strati

    2013-05-01

    Full Text Available The present work is intended to be an introduction to the Superposition Theory of David Carfì. In particular I shall depict the meaning of his brand new theory, on the one hand in an informal fashion and on the other hand by giving a formal approach of the algebraic structure of the theory: the S-linear algebra. This kind of structure underpins the notion of S-spaces (or Carfì-spaces by defining both its properties and its nature. Thus I shall define the S-triple as the fundamental principle upon which the S-linear algebra is built up.

  8. Are the ICD-10 or DSM-5 diagnostic systems able to define those who will benefit from treatment for depression?

    Science.gov (United States)

    Montgomery, Stuart

    2016-08-01

    Two widely used diagnostic systems, the International Statistical Classification of Diseases and Related Health Problems (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), are reviewed for their ability to define those who will benefit from active treatment rather than placebo. Both systems suffer from a weakness in defining symptoms sufficiently clearly to separate depression from normal mood variations in the general population. Consequently, normal individuals may be medicalized and defined as suffering from and treated for depression. Also, in mild depression, unlike moderate depression, a lack of significant separation of active treatment from placebo has been shown in individual double-blind, placebo-controlled studies and in meta-analyses of these treatment studies. Both systems would be more useful for treatment purposes if they provided a clearer symptomatic definition of moderate depression, as is widely used in pivotal regulatory standard efficacy studies.

  9. Defining and Differentiating the Makerspace

    Science.gov (United States)

    Dousay, Tonia A.

    2017-01-01

    Many resources now punctuate the maker movement landscape. However, some schools and communities still struggle to understand this burgeoning movement. How do we define these spaces and differentiate them from previous labs and shops? Through a multidimensional framework, stakeholders should consider how the structure, access, staffing, and tools…

  10. Indico CONFERENCE: Define the Programme

    CERN Multimedia

    CERN. Geneva; Ferreira, Pedro

    2017-01-01

    In this tutorial you are going to learn how to define the programme of a conference in Indico. The program of your conference is divided in different “tracks”. Tracks represent the subject matter of the conference, such as “Online Computing”, “Offline Computing”, and so on.

  11. Black hole thermodynamics from a variational principle: asymptotically conical backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    An, Ok Song [SISSA and INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste (Italy); Department of Physics, Kim Il Sung University,Ryongnam Dong, TaeSong District, Pyongyang, D.P.R. (Korea, Republic of); ICTP,Strada Costiera 11, 34014 Trieste (Italy); Cvetič, Mirjam [Department of Physics and Astronomy, University of Pennsylvania,209 S 33rd St, Philadelphia, PA 19104 (United States); Center for Applied Mathematics and Theoretical Physics, University of Maribor,Mladinska 3, SI2000 Maribor (Slovenia); Papadimitriou, Ioannis [SISSA and INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste (Italy)

    2016-03-14

    The variational problem of gravity theories is directly related to black hole thermodynamics. For asymptotically locally AdS backgrounds it is known that holographic renormalization results in a variational principle in terms of equivalence classes of boundary data under the local asymptotic symmetries of the theory, which automatically leads to finite conserved charges satisfying the first law of thermodynamics. We show that this connection holds well beyond asymptotically AdS black holes. In particular, we formulate the variational problem for N=2 STU supergravity in four dimensions with boundary conditions corresponding to those obeyed by the so called ‘subtracted geometries’. We show that such boundary conditions can be imposed covariantly in terms of a set of asymptotic second class constraints, and we derive the appropriate boundary terms that render the variational problem well posed in two different duality frames of the STU model. This allows us to define finite conserved charges associated with any asymptotic Killing vector and to demonstrate that these charges satisfy the Smarr formula and the first law of thermodynamics. Moreover, by uplifting the theory to five dimensions and then reducing on a 2-sphere, we provide a precise map between the thermodynamic observables of the subtracted geometries and those of the BTZ black hole. Surface terms play a crucial role in this identification.

  12. Some remarks on variational and quasi-variational inequalities of monotone operators

    International Nuclear Information System (INIS)

    Siddiqi, A.H.

    1990-08-01

    In this paper we study a fairly general class of variational and quasi-variational inequalities problem which represent some important physical phenomena. Several well-known results concerning variational inequalities are special cases of our results. Existence, uniqueness and numerical analysis of this problem have been studied. (author). 39 refs

  13. Dynamics of nonholonomic systems from variational principles embedded variation identity

    International Nuclear Information System (INIS)

    Guo Yongxin; Liu Shixing; Liu Chang; Chang Peng

    2009-01-01

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  14. Dynamics of nonholonomic systems from variational principles embedded variation identity

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yongxin, E-mail: yxguo@lnu.edu.c [College of Physics, Liaoning University, Shenyang 110036 (China); Liu Shixing [College of Physics, Liaoning University, Shenyang 110036 (China); Liu Chang; Chang Peng [Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081 (China)

    2009-10-19

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  15. Identification of the Diffusion Parameter in Nonlocal Steady Diffusion Problems

    Energy Technology Data Exchange (ETDEWEB)

    D’Elia, M., E-mail: mdelia@fsu.edu, E-mail: mdelia@sandia.gov [Sandia National Laboratories (United States); Gunzburger, M. [Florida State University (United States)

    2016-04-15

    The problem of identifying the diffusion parameter appearing in a nonlocal steady diffusion equation is considered. The identification problem is formulated as an optimal control problem having a matching functional as the objective of the control and the parameter function as the control variable. The analysis makes use of a nonlocal vector calculus that allows one to define a variational formulation of the nonlocal problem. In a manner analogous to the local partial differential equations counterpart, we demonstrate, for certain kernel functions, the existence of at least one optimal solution in the space of admissible parameters. We introduce a Galerkin finite element discretization of the optimal control problem and derive a priori error estimates for the approximate state and control variables. Using one-dimensional numerical experiments, we illustrate the theoretical results and show that by using nonlocal models it is possible to estimate non-smooth and discontinuous diffusion parameters.

  16. AIDS defining disease: Disseminated cryptococcosis

    Directory of Open Access Journals (Sweden)

    Roshan Anupama

    2006-01-01

    Full Text Available Disseminated cryptococcosis is one of the acquired immune deficiency syndrome defining criteria and the most common cause of life threatening meningitis. Disseminated lesions in the skin manifest as papules or nodules that mimic molluscum contagiosum (MC. We report here a human immunodeficiency virus positive patient who presented with MC like lesions. Disseminated cryptococcosis was confirmed by India ink preparation and histopathology. The condition of the patient improved with amphotercin B.

  17. How do people define moderation?

    Science.gov (United States)

    vanDellen, Michelle R; Isherwood, Jennifer C; Delose, Julie E

    2016-06-01

    Eating in moderation is considered to be sound and practical advice for weight maintenance or prevention of weight gain. However, the concept of moderation is ambiguous, and the effect of moderation messages on consumption has yet to be empirically examined. The present manuscript examines how people define moderate consumption. We expected that people would define moderate consumption in ways that justified their current or desired consumption rather than view moderation as an objective standard. In Studies 1 and 2, moderate consumption was perceived to involve greater quantities of an unhealthy food (chocolate chip cookies, gummy candies) than perceptions of how much one should consume. In Study 3, participants generally perceived themselves to eat in moderation and defined moderate consumption as greater than their personal consumption. Furthermore, definitions of moderate consumption were related to personal consumption behaviors. Results suggest that the endorsement of moderation messages allows for a wide range of interpretations of moderate consumption. Thus, we conclude that moderation messages are unlikely to be effective messages for helping people maintain or lose weight. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Variational inequalities and flow in porous media

    International Nuclear Information System (INIS)

    Chipot, M.

    1984-01-01

    This book is concerned with regularity theory for obstacle problems, and with the dam problem, which, in the rectangular case, is one of the most interesting applications of variational inequalities with an obstacle

  19. Balance Problems

    Science.gov (United States)

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

  20. Definability and almost disjoint families

    DEFF Research Database (Denmark)

    Törnquist, Asger Dag

    2018-01-01

    We show that there are no infinite maximal almost disjoint ("mad") families in Solovay's model, thus solving a long-standing problem posed by A.D.R. Mathias in 1967. We also give a new proof of Mathias' theorem that no analytic infinite almost disjoint family can be maximal, and show more generally...

  1. 1. round table - Nuclear wastes and radioactive materials. 2. round table - risks linked with nuclear wastes and materials. 3. round table - the problem of long-term management of medium-high activity and long lived wastes. The process defined by the 1991 law

    International Nuclear Information System (INIS)

    2005-01-01

    The law from December 30, 1991, precisely defines 3 axes of researches for the management of high level and long-lived radioactive wastes: separation/transmutation, surface storage and underground disposal. A global evaluation report about these researches is to be supplied in 2006 by the French government to the Parliament. A first synthesis of the knowledge gained after 14 years of research has led the national commission of the public debate (CNDP) to organize a national debate about the general options of management of high-level and long-lived radioactive wastes before the 2006 date line. The debate comprises 4 public hearings (September 2005: Bar-le-Duc, Saint-Dizier, Pont-du-Gard, Cherbourg), 12 round-tables (October and November 2005: Paris, Joinville, Caen, Nancy, Marseille), a synthesis meeting (December 2005, Dunkerque) and a closing meeting (January 2006, Lyon). This document is the synthesis of the debates of the first round table of Paris about the problems raised by nuclear wastes in the case of the geologic disposal option. Four families of questions have been tackled: 1 - the exhaustiveness of ANDRA's inventory, the solutions foreseen for the different types of wastes; 2 - the high-medium activity wastes and their processing; 3 - the management of non-reprocessed spent MOX fuels; 4 - the safety and security standards used and their establishment. Four presentations are attached to these proceedings and deal with: the measured and estimated inventory of all radioactive wastes; the inventory and management of radioactive wastes and the place of citizens; the point of view of the nuclear safety authority; conditioning and storage. (J.S.)

  2. [Population problem, comprehension problem].

    Science.gov (United States)

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

  3. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Roetter, Daniel Enrique Lucani

    2015-01-01

    Software Defined Networking (SDN) and Network Coding (NC) are two key concepts in networking that have garnered a large attention in recent years. On the one hand, SDN's potential to virtualize services in the Internet allows a large flexibility not only for routing data, but also to manage....... This paper advocates for the use of SDN to bring about future Internet and 5G network services by incorporating network coding (NC) functionalities. The inherent flexibility of both SDN and NC provides a fertile ground to envision more efficient, robust, and secure networking designs, that may also...

  4. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Hansen, Jonas; Roetter, Daniel Enrique Lucani; Krigslund, Jeppe

    2015-01-01

    Software defined networking has garnered large attention due to its potential to virtualize services in the Internet, introducing flexibility in the buffering, scheduling, processing, and routing of data in network routers. SDN breaks the deadlock that has kept Internet network protocols stagnant...... for decades, while applications and physical links have evolved. This article advocates for the use of SDN to bring about 5G network services by incorporating network coding (NC) functionalities. The latter constitutes a major leap forward compared to the state-of-the- art store and forward Internet paradigm...

  5. (Re)Defining Salesperson Motivation

    DEFF Research Database (Denmark)

    Khusainova, Rushana; de Jong, Ad; Lee, Nick

    2018-01-01

    The construct of motivation is one of the central themes in selling and sales management research. Yet, to-date no review article exists that surveys the construct (both from an extrinsic and intrinsic motivation context), critically evaluates its current status, examines various key challenges...... apparent from the extant research, and suggests new research opportunities based on a thorough review of past work. The authors explore how motivation is defined, major theories underpinning motivation, how motivation has historically been measured, and key methodologies used over time. In addition......, attention is given to principal drivers and outcomes of salesperson motivation. A summarizing appendix of key articles in salesperson motivation is provided....

  6. Defining Usability of PN Services

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Ahola, Titta; Fleury, Alexandre

    In this deliverable usability and user experience are defined in relation to MAGNET Beyond technologies, and it is described how the main MAGNET Beyond concepts can be evaluated through the involvement of users. The concepts include the new "Activity based communication approach" for interacting...... with the MAGNET Beyond system, as well as the core concepts: Personal Network, Personal Network-Federation, Service Discovery, User Profile Management, Personal Network Management, Privacy and Security and Context Awareness. The overall plans for the final usability evaluation are documented based on the present...

  7. Troubleshooting of Software Defined Networks

    OpenAIRE

    Sistek, Haris

    2015-01-01

    Network troubleshooting is a field where automation is sorely needed. While the network has grown in many other ways since 1960s, the tools we use to troubleshoot and manage it have stayed very much the same. Could we use the programmability of SDN to automate this problem? In this thesis work, we developed a prototype that would systematically troubleshoot the network with automation. The prototype automatically captures network behaviour, matches it against a network policy and creates its ...

  8. Expressiveness and definability in circumscription

    Directory of Open Access Journals (Sweden)

    Francicleber Martins Ferreira

    2011-06-01

    Full Text Available We investigate expressiveness and definability issues with respect to minimal models, particularly in the scope of Circumscription. First, we give a proof of the failure of the Löwenheim-Skolem Theorem for Circumscription. Then we show that, if the class of P; Z-minimal models of a first-order sentence is Δ-elementary, then it is elementary. That is, whenever the circumscription of a first-order sentence is equivalent to a first-order theory, then it is equivalent to a finitely axiomatizable one. This means that classes of models of circumscribed theories are either elementary or not Δ-elementary. Finally, using the previous result, we prove that, whenever a relation Pi is defined in the class of P; Z-minimal models of a first-order sentence Φ and whenever such class of P; Z-minimal models is Δ-elementary, then there is an explicit definition ψ for Pi such that the class of P; Z-minimal models of Φ is the class of models of Φ ∧ ψ. In order words, the circumscription of P in Φ with Z varied can be replaced by Φ plus this explicit definition ψ for Pi.

  9. Defining Quality in Undergraduate Education

    Directory of Open Access Journals (Sweden)

    Alison W. Bowers

    2018-01-01

    Full Text Available Objectives: This research brief explores the literature addressing quality in undergraduate education to identify what previous research has said about quality and to offer future directions for research on quality in undergraduate education. Method: We conducted a scoping review to provide a broad overview of existing research. Using targeted search terms in academic databases, we identified and reviewed relevant academic literature to develop emergent themes and implications for future research. Results: The exploratory review of the literature revealed a range of thoughtful discussions and empirical studies attempting to define quality in undergraduate education. Many publications highlighted the importance of including different stakeholder perspectives and presented some of the varying perceptions of quality among different stakeholders. Conclusions: While a number of researchers have explored and written about how to define quality in undergraduate education, there is not a general consensus regarding a definition of quality in undergraduate education. Past research offers a range of insights, models, and data to inform future research. Implication for Theory and/or Practice: We provide four recommendations for future research to contribute to a high quality undergraduate educational experience. We suggest more comprehensive systematic reviews of the literature as a next step.

  10. Terminology, the importance of defining.

    Science.gov (United States)

    van Mil, J W Foppe; Henman, Martin

    2016-06-01

    Multiple terms and definitions exist to describe specific aspects of pharmacy practice and service provision. This commentary explores the reasons for different interpretations of words and concepts in pharmaceutical care and pharmacy practice research. Reasons for this variation can be found in language, culture, profession and may also depend on developments over time. A list of words is provided where the authors think that currently multiple interpretations are possible. To make sure that the reader understands the essence, it seems imperative that authors include a definition of the topics that they actually study in their papers, and that they clearly cite existing definitions or refer to collections of definitions such as existing glossaries. It is important that presenters, authors and reviewers of pharmacy practice papers pay more attention to this aspect of describing studies.

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

    Directory of Open Access Journals (Sweden)

    Dieter Egerer Michael

    2015-03-01

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

  12. Metaleptic Variations

    OpenAIRE

    Pernot, Dominique

    2014-01-01

    Les derniers romans de Gabriel Josipovici offrent beaucoup de variété, allant de la parodie, de la fiction comique légère, dans Only Joking et Making Mistakes, à des sujets plus graves, plus personnels, ontologiques. Dans un court roman, Everything Passes, et dans un roman majeur, Goldberg: Variations, le lecteur est amené à se poser des questions sur la nature mystérieuse de la réalité, qui est, trop souvent, acceptée sans conteste par de nombreux roma...

  13. A min-max variational principle

    International Nuclear Information System (INIS)

    Georgiev, P.G.

    1995-11-01

    In this paper a variational principle for min-max problems is proved that is of the same spirit as Deville-Godefroy-Zizler's variational principle for minimization problems. A localization theorem in which the mini-max points for the perturbed function with respect top a given ε-min-max point are localized is presented. 3 refs

  14. Defining the "normal" postejaculate urinalysis.

    Science.gov (United States)

    Mehta, Akanksha; Jarow, Jonathan P; Maples, Pat; Sigman, Mark

    2012-01-01

    Although sperm have been shown to be present in the postejaculate urinalysis (PEU) of both fertile and infertile men, the number of sperm present in the PEU of the general population has never been well defined. The objective of this study was to describe the semen and PEU findings in both the general and infertile population, in order to develop a better appreciation for "normal." Infertile men (n = 77) and control subjects (n = 71) were prospectively recruited. Exclusion criteria included azoospermia and medications known to affect ejaculation. All men underwent a history, physical examination, semen analysis, and PEU. The urine was split into 2 containers: PEU1, the initial voided urine, and PEU2, the remaining voided urine. Parametric statistical methods were applied for data analysis to compare sperm concentrations in each sample of semen and urine between the 2 groups of men. Controls had higher average semen volume (3.3 ± 1.6 vs 2.0 ± 1.4 mL, P sperm concentrations (112 million vs 56.2 million, P = .011), compared with infertile men. The presence of sperm in urine was common in both groups, but more prevalent among infertile men (98.7% vs 88.7%, P = .012), in whom it comprised a greater proportion of the total sperm count (46% vs 24%, P = .022). The majority of sperm present in PEU were seen in PEU1 of both controls (69%) and infertile men (88%). An association was noted between severe oligospermia (sperm counts in PEU (sperm in the urine compared with control, there is a large degree of overlap between the 2 populations, making it difficult to identify a specific threshold to define a positive test. Interpretation of a PEU should be directed by whether the number of sperm in the urine could affect subsequent management.

  15. Miniature EVA Software Defined Radio

    Science.gov (United States)

    Pozhidaev, Aleksey

    2012-01-01

    As NASA embarks upon developing the Next-Generation Extra Vehicular Activity (EVA) Radio for deep space exploration, the demands on EVA battery life will substantially increase. The number of modes and frequency bands required will continue to grow in order to enable efficient and complex multi-mode operations including communications, navigation, and tracking applications. Whether conducting astronaut excursions, communicating to soldiers, or first responders responding to emergency hazards, NASA has developed an innovative, affordable, miniaturized, power-efficient software defined radio that offers unprecedented power-efficient flexibility. This lightweight, programmable, S-band, multi-service, frequency- agile EVA software defined radio (SDR) supports data, telemetry, voice, and both standard and high-definition video. Features include a modular design, an easily scalable architecture, and the EVA SDR allows for both stationary and mobile battery powered handheld operations. Currently, the radio is equipped with an S-band RF section. However, its scalable architecture can accommodate multiple RF sections simultaneously to cover multiple frequency bands. The EVA SDR also supports multiple network protocols. It currently implements a Hybrid Mesh Network based on the 802.11s open standard protocol. The radio targets RF channel data rates up to 20 Mbps and can be equipped with a real-time operating system (RTOS) that can be switched off for power-aware applications. The EVA SDR's modular design permits implementation of the same hardware at all Network Nodes concept. This approach assures the portability of the same software into any radio in the system. It also brings several benefits to the entire system including reducing system maintenance, system complexity, and development cost.

  16. Quantum computing. Defining and detecting quantum speedup.

    Science.gov (United States)

    Rønnow, Troels F; Wang, Zhihui; Job, Joshua; Boixo, Sergio; Isakov, Sergei V; Wecker, David; Martinis, John M; Lidar, Daniel A; Troyer, Matthias

    2014-07-25

    The development of small-scale quantum devices raises the question of how to fairly assess and detect quantum speedup. Here, we show how to define and measure quantum speedup and how to avoid pitfalls that might mask or fake such a speedup. We illustrate our discussion with data from tests run on a D-Wave Two device with up to 503 qubits. By using random spin glass instances as a benchmark, we found no evidence of quantum speedup when the entire data set is considered and obtained inconclusive results when comparing subsets of instances on an instance-by-instance basis. Our results do not rule out the possibility of speedup for other classes of problems and illustrate the subtle nature of the quantum speedup question. Copyright © 2014, American Association for the Advancement of Science.

  17. DEFINED CONTRIBUTION PLANS, DEFINED BENEFIT PLANS, AND THE ACCUMULATION OF RETIREMENT WEALTH

    Science.gov (United States)

    Poterba, James; Rauh, Joshua; Venti, Steven; Wise, David

    2010-01-01

    The private pension structure in the United States, once dominated by defined benefit (DB) plans, is currently divided between defined contribution (DC) and DB plans. Wealth accumulation in DC plans depends on the participant's contribution behavior and on financial market returns, while accumulation in DB plans is sensitive to a participant's labor market experience and to plan parameters. This paper simulates the distribution of retirement wealth under representative DB and DC plans. It uses data from the Health and Retirement Study (HRS) to explore how asset returns, earnings histories, and retirement plan characteristics contribute to the variation in retirement wealth outcomes. We simulate DC plan accumulation by randomly assigning individuals a share of wages that they and their employer contribute to the plan. We consider several possible asset allocation strategies, with asset returns drawn from the historical return distribution. Our DB plan simulations draw earnings histories from the HRS, and randomly assign each individual a pension plan drawn from a sample of large private and public defined benefit plans. The simulations yield distributions of both DC and DB wealth at retirement. Average retirement wealth accruals under current DC plans exceed average accruals under private sector DB plans, although DC plans are also more likely to generate very low retirement wealth outcomes. The comparison of current DC plans with more generous public sector DB plans is less definitive, because public sector DB plans are more generous on average than their private sector counterparts. PMID:21057597

  18. Canonical variate regression.

    Science.gov (United States)

    Luo, Chongliang; Liu, Jin; Dey, Dipak K; Chen, Kun

    2016-07-01

    In many fields, multi-view datasets, measuring multiple distinct but interrelated sets of characteristics on the same set of subjects, together with data on certain outcomes or phenotypes, are routinely collected. The objective in such a problem is often two-fold: both to explore the association structures of multiple sets of measurements and to develop a parsimonious model for predicting the future outcomes. We study a unified canonical variate regression framework to tackle the two problems simultaneously. The proposed criterion integrates multiple canonical correlation analysis with predictive modeling, balancing between the association strength of the canonical variates and their joint predictive power on the outcomes. Moreover, the proposed criterion seeks multiple sets of canonical variates simultaneously to enable the examination of their joint effects on the outcomes, and is able to handle multivariate and non-Gaussian outcomes. An efficient algorithm based on variable splitting and Lagrangian multipliers is proposed. Simulation studies show the superior performance of the proposed approach. We demonstrate the effectiveness of the proposed approach in an [Formula: see text] intercross mice study and an alcohol dependence study. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Approximation of Fixed Points of Nonexpansive Mappings and Solutions of Variational Inequalities

    Directory of Open Access Journals (Sweden)

    Chidume CO

    2008-01-01

    Full Text Available Abstract Let be a real -uniformly smooth Banach space with constant , . Let and be a nonexpansive map and an -strongly accretive map which is also -Lipschitzian, respectively. Let be a real sequence in that satisfies the following condition: and . For and , define a sequence iteratively in by , , . Then, converges strongly to the unique solution of the variational inequality problem (search for such that for all , where . A convergence theorem related to finite family of nonexpansive maps is also proved.

  20. Visualization of Variation and Variability

    NARCIS (Netherlands)

    Busking, S.

    2014-01-01

    As datasets grow in size and complexity, the importance of comparison as a tool for analysis is growing. We define comparison as the act of analyzing variation or variability based on two or more specific instances of the data. This thesis explores a number of cases spread across the range of

  1. MAP estimators and their consistency in Bayesian nonparametric inverse problems

    KAUST Repository

    Dashti, M.

    2013-09-01

    We consider the inverse problem of estimating an unknown function u from noisy measurements y of a known, possibly nonlinear, map applied to u. We adopt a Bayesian approach to the problem and work in a setting where the prior measure is specified as a Gaussian random field μ0. We work under a natural set of conditions on the likelihood which implies the existence of a well-posed posterior measure, μy. Under these conditions, we show that the maximum a posteriori (MAP) estimator is well defined as the minimizer of an Onsager-Machlup functional defined on the Cameron-Martin space of the prior; thus, we link a problem in probability with a problem in the calculus of variations. We then consider the case where the observational noise vanishes and establish a form of Bayesian posterior consistency for the MAP estimator. We also prove a similar result for the case where the observation of can be repeated as many times as desired with independent identically distributed noise. The theory is illustrated with examples from an inverse problem for the Navier-Stokes equation, motivated by problems arising in weather forecasting, and from the theory of conditioned diffusions, motivated by problems arising in molecular dynamics. © 2013 IOP Publishing Ltd.

  2. MAP estimators and their consistency in Bayesian nonparametric inverse problems

    International Nuclear Information System (INIS)

    Dashti, M; Law, K J H; Stuart, A M; Voss, J

    2013-01-01

    We consider the inverse problem of estimating an unknown function u from noisy measurements y of a known, possibly nonlinear, map G applied to u. We adopt a Bayesian approach to the problem and work in a setting where the prior measure is specified as a Gaussian random field μ 0 . We work under a natural set of conditions on the likelihood which implies the existence of a well-posed posterior measure, μ y . Under these conditions, we show that the maximum a posteriori (MAP) estimator is well defined as the minimizer of an Onsager–Machlup functional defined on the Cameron–Martin space of the prior; thus, we link a problem in probability with a problem in the calculus of variations. We then consider the case where the observational noise vanishes and establish a form of Bayesian posterior consistency for the MAP estimator. We also prove a similar result for the case where the observation of G(u) can be repeated as many times as desired with independent identically distributed noise. The theory is illustrated with examples from an inverse problem for the Navier–Stokes equation, motivated by problems arising in weather forecasting, and from the theory of conditioned diffusions, motivated by problems arising in molecular dynamics. (paper)

  3. The nonholonomic variational principle

    Energy Technology Data Exchange (ETDEWEB)

    Krupkova, Olga [Department of Algebra and Geometry, Faculty of Science, Palacky University, Tomkova 40, 779 00 Olomouc (Czech Republic); Department of Mathematics, La Trobe University, Bundoora, Victoria 3086 (Australia)], E-mail: krupkova@inf.upol.cz

    2009-05-08

    A variational principle for mechanical systems and fields subject to nonholonomic constraints is found, providing Chetaev-reduced equations as equations for extremals. Investigating nonholonomic variations of the Chetaev type and their properties, we develop foundations of the calculus of variations on constraint manifolds, modelled as fibred submanifolds in jet bundles. This setting is appropriate to study general first-order 'nonlinear nonitegrable constraints' that locally are given by a system of first-order ordinary or partial differential equations. We obtain an invariant constrained first variation formula and constrained Euler-Lagrange equations both in intrinsic and coordinate forms, and show that the equations are the same as Chetaev equations 'without Lagrange multipliers', introduced recently by other methods. We pay attention to two possible settings: first, when the constrained system arises from an unconstrained Lagrangian system defined in a neighbourhood of the constraint, and second, more generally, when an 'internal' constrained system on the constraint manifold is given. In the latter case a corresponding unconstrained system need not be a Lagrangian, nor even exist. We also study in detail an important particular case: nonholonomic constraints that can be alternatively modelled by means of (co)distributions in the total space of the fibred manifold; in nonholonomic mechanics this happens whenever constraints affine in velocities are considered. It becomes clear that (and why) if the distribution is completely integrable (= the constraints are semiholonomic), the principle of virtual displacements holds and can be used to obtain the constrained first variational formula by a more or less standard procedure, traditionally used when unconstrained or holonomic systems are concerned. If, however, the constraint is nonintegrable, no significant simplifications are available. Among others, some properties of nonholonomic

  4. Semidefinite linear complementarity problems

    International Nuclear Information System (INIS)

    Eckhardt, U.

    1978-04-01

    Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de

  5. Speech Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Speech Problems KidsHealth / For Teens / Speech Problems What's in ... a person's ability to speak clearly. Some Common Speech and Language Disorders Stuttering is a problem that ...

  6. Hemiequilibrium problems

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2004-01-01

    Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.

  7. Experiencing variation

    DEFF Research Database (Denmark)

    Kobayashi, Sofie; Berge, Maria; Grout, Brian William Wilson

    2017-01-01

    This study contributes towards a better understanding of learning dynamics in doctoral supervision by analysing how learning opportunities are created in the interaction between supervisors and PhD students, using the notion of experiencing variation as a key to learning. Empirically, we have based...... the study on four video-recorded sessions, with four different PhD students and their supervisors, all from life sciences. Our analysis revealed that learning opportunities in the supervision sessions concerned either the content matter of research (for instance, understanding soil structure......), or the research methods— more specifically how to produce valid results. Our results illustrate how supervisors and PhD students create a space of learning together in their particular discipline by varying critical aspects of their research in their discussions. Situations where more openended research issues...

  8. The benefits of defining "snacks".

    Science.gov (United States)

    Hess, Julie M; Slavin, Joanne L

    2018-04-18

    Whether eating a "snack" is considered a beneficial or detrimental behavior is largely based on how "snack" is defined. The term "snack food" tends to connote energy-dense, nutrient-poor foods high in nutrients to limit (sugar, sodium, and/or saturated fat) like cakes, cookies, chips and other salty snacks, and sugar-sweetened beverages. Eating a "snack food" is often conflated with eating a "snack," however, leading to an overall perception of snacks as a dietary negative. Yet the term "snack" can also refer simply to an eating occasion outside of breakfast, lunch, or dinner. With this definition, the evidence to support health benefits or detriments to eating a "snack" remains unclear, in part because relatively few well-designed studies that specifically focus on the impact of eating frequency on health have been conducted. Despite these inconsistencies and research gaps, in much of the nutrition literature, "snacking" is still referred to as detrimental to health. As discussed in this review, however, there are multiple factors that influence the health impacts of snacking, including the definition of "snack" itself, the motivation to snack, body mass index of snack eaters, and the food selected as a snack. Without a definition of "snack" and a body of research using methodologically rigorous protocols, determining the health impact of eating a "snack" will continue to elude the nutrition research community and prevent the development of evidence-based policies about snacking that support public health. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Software Defined Networks in Wireless Sensor Architectures

    Directory of Open Access Journals (Sweden)

    Jesús Antonio Puente Fernández

    2018-03-01

    Full Text Available Nowadays, different protocols coexist in Internet that provides services to users. Unfortunately, control decisions and distributed management make it hard to control networks. These problems result in an inefficient and unpredictable network behaviour. Software Defined Networks (SDN is a new concept of network architecture. It intends to be more flexible and to simplify the management in networks with respect to traditional architectures. Each of these aspects are possible because of the separation of control plane (controller and data plane (switches in network devices. OpenFlow is the most common protocol for SDN networks that provides the communication between control and data planes. Moreover, the advantage of decoupling control and data planes enables a quick evolution of protocols and also its deployment without replacing data plane switches. In this survey, we review the SDN technology and the OpenFlow protocol and their related works. Specifically, we describe some technologies as Wireless Sensor Networks and Wireless Cellular Networks and how SDN can be included within them in order to solve their challenges. We classify different solutions for each technology attending to the problem that is being fixed.

  10. [Defining AIDS terminology. A practical approach].

    Science.gov (United States)

    Locutura, Jaime; Almirante, Benito; Berenguer, Juan; Muñoz, Agustín; Peña, José María

    2003-01-01

    Since the appearance of AIDS, the study of this disease has generated a large amount of information and an extensive related vocabulary comprised of new terms or terms borrowed from other scientific fields. The urgent need to provide names for newly described phenomena and concepts in this field has resulted in the application of terms that are not always appropriate from the linguistic and scientific points of view. We discuss the difficulties in attempting to create adequate AIDS terminology in the Spanish language, considering both the general problems involved in building any scientific vocabulary and the specific problems inherent to this activity in a field whose defining illness has important social connotations. The pressure exerted by the predominance of the English language in reporting scientific knowledge is considered, and the inappropriate words most often found in a review of current literature are examined. Finally, attending to the two most important criteria for the creation of new scientific terms, accuracy and linguistic correction, we propose some well thought-out alternatives that conform to the essence of the Spanish language.

  11. Software-defined Quantum Networking Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-01

    The software enables a user to perform modeling and simulation of software-defined quantum networks. The software addresses the problem of how to synchronize transmission of quantum and classical signals through multi-node networks and to demonstrate quantum information protocols such as quantum teleportation. The software approaches this problem by generating a graphical model of the underlying network and attributing properties to each node and link in the graph. The graphical model is then simulated using a combination of discrete-event simulators to calculate the expected state of each node and link in the graph at a future time. A user interacts with the software by providing an initial network model and instantiating methods for the nodes to transmit information with each other. This includes writing application scripts in python that make use of the software library interfaces. A user then initiates the application scripts, which invokes the software simulation. The user then uses the built-in diagnostic tools to query the state of the simulation and to collect statistics on synchronization.

  12. Defining safety goals. 2. Basic Consideration on Defining Safety Goals

    International Nuclear Information System (INIS)

    Hakata, T.

    2001-01-01

    cancer and severe hereditary effects are 10 x 10 -2 /Sv and 1.3 x10 -2 /Sv, respectively. The basic safety goals can be expressed by the complementary accumulative distribution function (CCDF) of dose versus frequencies of events: Pc(C > Cp) 5 (Cp/Co) -α . The aversion factor a is here expressed by the following arbitrary equation, which gives a polynomial curve of the order of m on a logarithmic plane: α = a+b(log(Cp/Co)) m , where: Pc = CCDF frequency for Cp (/yr), Cp = dose (mSv), Co = Cp for Pc =1, a, b, m = constants. Figure 1 shows a typical tolerable risk profile (risk limit curve), which is drawn so that all the points obtained in the previous discussions are above the curve (Co=1, a=1, b=0.0772, and m = 2). Safety criteria by ANS (Ref. 2) and SHE (Ref. 3) are shown in Fig. 1 for comparison. An aversion of a factor of 2 is resulted between 1 mSv and 1 Sv. No ALARA is included, which must be considered in defining specific safety goals. The frequency of a single class of events must be lower than the CCDF profile, and a curve lower by a factor of 10 is drawn in Fig. 1. The doses referenced in the current Japanese safety guidelines and site criteria are shown in Fig. 1. The referenced doses seem reasonable, considering the conservatism in the analysis of design-basis accidents. Specific safety goals for each sort of facility can be defined based on the basic safety goals, reflecting the characteristics of the facilities and considering ALARA. The indexes of engineering terms, such as CMF and LERF, are preferable for nuclear power plants, although interpretation from dose to the engineering terms is needed. Other indexes may be used (such as frequency of criticality accidents, etc.) for facilities except for power plants. The applicability of safety goals will thus be improved. Figure 2 shows the relative risk factors (1, 1%, and 0.1%) versus the severity of radiation effects. This might indicate the adequacy of the risk factors. The absolute risk limits, which

  13. Defining Tobacco Regulatory Science Competencies.

    Science.gov (United States)

    Wipfli, Heather L; Berman, Micah; Hanson, Kacey; Kelder, Steven; Solis, Amy; Villanti, Andrea C; Ribeiro, Carla M P; Meissner, Helen I; Anderson, Roger

    2017-02-01

    In 2013, the National Institutes of Health and the Food and Drug Administration funded a network of 14 Tobacco Centers of Regulatory Science (TCORS) with a mission that included research and training. A cross-TCORS Panel was established to define tobacco regulatory science (TRS) competencies to help harmonize and guide their emerging educational programs. The purpose of this paper is to describe the Panel's work to develop core TRS domains and competencies. The Panel developed the list of domains and competencies using a semistructured Delphi method divided into four phases occurring between November 2013 and August 2015. The final proposed list included a total of 51 competencies across six core domains and 28 competencies across five specialized domains. There is a need for continued discussion to establish the utility of the proposed set of competencies for emerging TRS curricula and to identify the best strategies for incorporating these competencies into TRS training programs. Given the field's broad multidisciplinary nature, further experience is needed to refine the core domains that should be covered in TRS training programs versus knowledge obtained in more specialized programs. Regulatory science to inform the regulation of tobacco products is an emerging field. The paper provides an initial list of core and specialized domains and competencies to be used in developing curricula for new and emerging training programs aimed at preparing a new cohort of scientists to conduct critical TRS research. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Introduction to the calculus of variations

    CERN Document Server

    Sagan, Hans

    1992-01-01

    Excellent text provides basis for thorough understanding of the problems, methods and techniques of the calculus of variations and prepares readers for the study of modern optimal control theory. Treatment limited to extensive coverage of single integral problems in one and more unknown functions. Carefully chosen variational problems and over 400 exercises. ""Should find wide acceptance as a text and reference.""-American Mathematical Monthly. 1969 edition. Bibliography.

  15. Defining and certifying green power

    International Nuclear Information System (INIS)

    1998-02-01

    Studies have shown that as electric utilities restructure from monopolistic utilities to competitive open access retailers, there is an increasing demand by individual and institutional customers for green power. In the United States, 17 electricity suppliers have offered customers the opportunity to buy energy generated from renewable sources such as photovoltaic panels, wind turbines and biomass. Twenty other utilities are conducting market research in preparation for offering a similar program. It was suggested that in order to help the customers make their choice based on accurate information, generating facilities should be obligated to provide credible information about the environmental performance of electricity supply through standardized environmental profile labels. A list of agreed upon environmental indicators and performance levels must be established so that the 'environmental friendliness' of different generating facilities can be measured. One of the problems in tackling this issue is that there is disagreement about what constitutes green power. Opinions range from wind and solar generation being the only two forms of green power, to including even natural gas and nuclear energy (i.e. under the right conditions). The two programs that are used for the certification of green power in Canada and the United States are Canada's Environmental Choice Program and California's Green-e Renewable Electricity Branding Program. This report describes the two programs and summarizes the results of interviews conducted on the definition and certification of green power. 15 refs

  16. No Problem? No Research, Little Learning ... Big Problem!

    Directory of Open Access Journals (Sweden)

    Fernando Ornelas Marques

    2012-06-01

    Full Text Available The motivation to carry out this study stemmed from the generalized perception that nowadays youth lacks the skills for the 21st century. Especially the high-level competences like critical thinking, problem solving and autonomy. Several tools can help to improve these competences (e.g. the SCRATCH programming language, but, as researchers and educators, we are mostly concerned with the skill to recognize problems. What if we do not find problems to solve? What if we do not even feel the need to find or solve problems? The problem is to recognize the problem; the next step is to equate the problem; finally we have to feel the need to solve it. No need? No invention. Recognizing a problem is probably the biggest problem of everyday life, because we are permanently faced with problems (many ill-defined problems, which we need to identify, equate and solve.

  17. Stochastic variational approach to minimum uncertainty states

    Energy Technology Data Exchange (ETDEWEB)

    Illuminati, F.; Viola, L. [Dipartimento di Fisica, Padova Univ. (Italy)

    1995-05-21

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schroedinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials. (author)

  18. Explaining the Mind: Problems, Problems

    OpenAIRE

    Harnad, Stevan

    2001-01-01

    The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

  19. Existence of evolutionary variational solutions via the calculus of variations

    Science.gov (United States)

    Bögelein, Verena; Duzaar, Frank; Marcellini, Paolo

    In this paper we introduce a purely variational approach to time dependent problems, yielding the existence of global parabolic minimizers, that is ∫0T ∫Ω [uṡ∂tφ+f(x,Du)] dx dt⩽∫0T ∫Ω f(x,Du+Dφ) dx dt, whenever T>0 and φ∈C0∞(Ω×(0,T),RN). For the integrand f:Ω×R→[0,∞] we merely assume convexity with respect to the gradient variable and coercivity. These evolutionary variational solutions are obtained as limits of maps depending on space and time minimizing certain convex variational functionals. In the simplest situation, with some growth conditions on f, the method provides the existence of global weak solutions to Cauchy-Dirichlet problems of parabolic systems of the type ∂tu-divDξf(x,Du)=0 in Ω×(0,∞).

  20. The hard problem of cooperation.

    Directory of Open Access Journals (Sweden)

    Kimmo Eriksson

    Full Text Available Based on individual variation in cooperative inclinations, we define the "hard problem of cooperation" as that of achieving high levels of cooperation in a group of non-cooperative types. Can the hard problem be solved by institutions with monitoring and sanctions? In a laboratory experiment we find that the answer is affirmative if the institution is imposed on the group but negative if development of the institution is left to the group to vote on. In the experiment, participants were divided into groups of either cooperative types or non-cooperative types depending on their behavior in a public goods game. In these homogeneous groups they repeatedly played a public goods game regulated by an institution that incorporated several of the key properties identified by Ostrom: operational rules, monitoring, rewards, punishments, and (in one condition change of rules. When change of rules was not possible and punishments were set to be high, groups of both types generally abided by operational rules demanding high contributions to the common good, and thereby achieved high levels of payoffs. Under less severe rules, both types of groups did worse but non-cooperative types did worst. Thus, non-cooperative groups profited the most from being governed by an institution demanding high contributions and employing high punishments. Nevertheless, in a condition where change of rules through voting was made possible, development of the institution in this direction was more often voted down in groups of non-cooperative types. We discuss the relevance of the hard problem and fit our results into a bigger picture of institutional and individual determinants of cooperative behavior.

  1. The hard problem of cooperation.

    Science.gov (United States)

    Eriksson, Kimmo; Strimling, Pontus

    2012-01-01

    Based on individual variation in cooperative inclinations, we define the "hard problem of cooperation" as that of achieving high levels of cooperation in a group of non-cooperative types. Can the hard problem be solved by institutions with monitoring and sanctions? In a laboratory experiment we find that the answer is affirmative if the institution is imposed on the group but negative if development of the institution is left to the group to vote on. In the experiment, participants were divided into groups of either cooperative types or non-cooperative types depending on their behavior in a public goods game. In these homogeneous groups they repeatedly played a public goods game regulated by an institution that incorporated several of the key properties identified by Ostrom: operational rules, monitoring, rewards, punishments, and (in one condition) change of rules. When change of rules was not possible and punishments were set to be high, groups of both types generally abided by operational rules demanding high contributions to the common good, and thereby achieved high levels of payoffs. Under less severe rules, both types of groups did worse but non-cooperative types did worst. Thus, non-cooperative groups profited the most from being governed by an institution demanding high contributions and employing high punishments. Nevertheless, in a condition where change of rules through voting was made possible, development of the institution in this direction was more often voted down in groups of non-cooperative types. We discuss the relevance of the hard problem and fit our results into a bigger picture of institutional and individual determinants of cooperative behavior.

  2. Prostate Problems

    Science.gov (United States)

    ... know the exact cause of your prostate problem. Prostatitis The cause of prostatitis depends on whether you ... prostate problem in men older than age 50. Prostatitis If you have a UTI, you may be ...

  3. General problems

    International Nuclear Information System (INIS)

    2005-01-01

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

  4. Learning Problems

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Learning Problems KidsHealth / For Kids / Learning Problems What's in ... for how to make it better. What Are Learning Disabilities? Learning disabilities aren't contagious, but they ...

  5. Ankle Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Ankle ProblemsFollow this chart for more information about problems that can cause ankle pain. Our trusted Symptom Checker is written and ...

  6. Application of eigenfunction orthogonalities to vibration problems

    CSIR Research Space (South Africa)

    Fedotov, I

    2009-07-01

    Full Text Available The modelling of vibration problems is of great importance in engineering. A popular method of analysing such problems is the variational method. The simplest vibration model is represented using the example of a long rod. Two kinds...

  7. Regularization of Nonmonotone Variational Inequalities

    International Nuclear Information System (INIS)

    Konnov, Igor V.; Ali, M.S.S.; Mazurkevich, E.O.

    2006-01-01

    In this paper we extend the Tikhonov-Browder regularization scheme from monotone to rather a general class of nonmonotone multivalued variational inequalities. We show that their convergence conditions hold for some classes of perfectly and nonperfectly competitive economic equilibrium problems

  8. Solving quantum optimal control problems using Clebsch variables and Lin constraints

    Science.gov (United States)

    Delgado-Téllez, M.; Ibort, A.; Rodríguez de la Peña, T.

    2018-01-01

    Clebsch variables (and Lin constraints) are applied to the study of a class of optimal control problems for affine-controlled quantum systems. The optimal control problem will be modelled with controls defined on an auxiliary space where the dynamical group of the system acts freely. The reciprocity between both theories: the classical theory defined by the objective functional and the quantum system, is established by using a suitable version of Lagrange’s multipliers theorem and a geometrical interpretation of the constraints of the system as defining a subspace of horizontal curves in an associated bundle. It is shown how the solutions of the variational problem defined by the objective functional determine solutions of the quantum problem. Then a new way of obtaining explicit solutions for a family of optimal control problems for affine-controlled quantum systems (finite or infinite dimensional) is obtained. One of its main advantages, is the the use of Clebsch variables allows to compute such solutions from solutions of invariant problems that can often be computed explicitly. This procedure can be presented as an algorithm that can be applied to a large class of systems. Finally, some simple examples, spin control, a simple quantum Hamiltonian with an ‘Elroy beanie’ type classical model and a controlled one-dimensional quantum harmonic oscillator, illustrating the main features of the theory, will be discussed.

  9. Defining meridians: a modern basis of understanding.

    Science.gov (United States)

    Longhurst, John C

    2010-06-01

    Acupuncture, one of the primary methods of treatment in traditional Oriental medicine, is based on a system of meridians. Along the meridians lie acupuncture points or acupoints, which are stimulated by needling, pressure or heat to resolve a clinical problem. A number of methods have been used to identify meridians and to explain them anatomically. Thus, tendinomuscular structures, primo-vessels (Bonghan ducts), regions of increased temperature and low skin resistance have been suggested to represent meridians or as methods to identify them. However, none of these methods have met the criteria for a meridian, an entity that, when stimulated by acupuncture can result in clinical improvement. More recently, modern physiologists have put forward the "neural hypothesis" stating that the clinical influence of acupuncture is transmitted primarily through stimulation of sensory nerves that provide signals to the brain, which processes this information and then causes clinical changes associated with treatment. Although additional research is warranted to investigate the role of some of the structures identified, it seems clear that the peripheral and central nervous system can now be considered to be the most rational basis for defining meridians. The meridian maps and associated acupoints located along them are best viewed as road maps that can guide practitioners towards applying acupuncture to achieve optimal clinical results. Copyright 2010 Korean Pharmacopuncture Institute. Published by .. All rights reserved.

  10. Defining Astrology in Ancient and Classical History

    Science.gov (United States)

    Campion, Nicholas

    2015-05-01

    Astrology in the ancient and classical worlds can be partly defined by its role, and partly by the way in which scholars spoke about it. The problem is complicated by the fact that the word is Greek - it has no Babylonian or Egyptian cognates - and even in Greece it was interchangeable with its cousin, 'astronomy'. Yet if we are to understand the role of the sky, stars and planets in culture, debates about the nature of ancient astrology, by both classical and modern scholars, must be taken into account. This talk will consider modern scholars' typologies of ancient astrology, together with ancient debates from Cicero in the 1st century BC, to Plotinus (204/5-270 AD) and Isidore of Seville (c. 560 - 4 April 636). It will consider the implications for our understanding of astronomy's role in culture, and conclude that in the classical period astrology may be best understood through its diversity and allegiance to competing philosophies, and that its functions were therefore similarly varied.

  11. A Two-Dimensional Helmholtz Equation Solution for the Multiple Cavity Scattering Problem

    Science.gov (United States)

    2013-02-01

    obtained by using the block Gauss – Seidel iterative meth- od. To show the convergence of the iterative method, we define the error between two...models to the general multiple cavity setting. Numerical examples indicate that the convergence of the Gauss – Seidel iterative method depends on the...variational approach. A block Gauss – Seidel iterative method is introduced to solve the cou- pled system of the multiple cavity scattering problem, where

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

    OpenAIRE

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

    2018-01-01

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

  13. Sparsity regularization for parameter identification problems

    International Nuclear Information System (INIS)

    Jin, Bangti; Maass, Peter

    2012-01-01

    The investigation of regularization schemes with sparsity promoting penalty terms has been one of the dominant topics in the field of inverse problems over the last years, and Tikhonov functionals with ℓ p -penalty terms for 1 ⩽ p ⩽ 2 have been studied extensively. The first investigations focused on regularization properties of the minimizers of such functionals with linear operators and on iteration schemes for approximating the minimizers. These results were quickly transferred to nonlinear operator equations, including nonsmooth operators and more general function space settings. The latest results on regularization properties additionally assume a sparse representation of the true solution as well as generalized source conditions, which yield some surprising and optimal convergence rates. The regularization theory with ℓ p sparsity constraints is relatively complete in this setting; see the first part of this review. In contrast, the development of efficient numerical schemes for approximating minimizers of Tikhonov functionals with sparsity constraints for nonlinear operators is still ongoing. The basic iterated soft shrinkage approach has been extended in several directions and semi-smooth Newton methods are becoming applicable in this field. In particular, the extension to more general non-convex, non-differentiable functionals by variational principles leads to a variety of generalized iteration schemes. We focus on such iteration schemes in the second part of this review. A major part of this survey is devoted to applying sparsity constrained regularization techniques to parameter identification problems for partial differential equations, which we regard as the prototypical setting for nonlinear inverse problems. Parameter identification problems exhibit different levels of complexity and we aim at characterizing a hierarchy of such problems. The operator defining these inverse problems is the parameter-to-state mapping. We first summarize some

  14. Exploring language variation across Europe

    DEFF Research Database (Denmark)

    Hovy, Dirk; Johannsen, Anders Trærup

    2016-01-01

    Language varies not only between countries, but also along regional and sociodemographic lines. This variation is one of the driving factors behind language change. However, investigating language variation is a complex undertaking: the more factors we want to consider, the more data we need. Tra...... use of large amounts of data and provides statistical analyses, maps, and interactive features that enable scholars to explore language variation in a data-driven way.......Language varies not only between countries, but also along regional and sociodemographic lines. This variation is one of the driving factors behind language change. However, investigating language variation is a complex undertaking: the more factors we want to consider, the more data we need...... training in both variational linguistics and computational methods, a combination that is still not common. We take a first step here to alleviate the problem by providing an interface to explore large-scale language variation along several socio-demographic factors without programming knowledge. It makes...

  15. Convergence analysis of variational and non-variational multigrid algorithms for the Laplace-Beltrami operator

    KAUST Repository

    Bonito, Andrea; Pasciak, Joseph E.

    2012-01-01

    is captured well enough by the coarsest grid. The main argument hinges on a perturbation analysis from an auxiliary variational algorithm defined directly on the smooth surface. In addition, the vanishing mean value constraint is imposed on each level, thereby

  16. Indico CONFERENCE: Define the Call for Abstracts

    CERN Multimedia

    CERN. Geneva; Ferreira, Pedro

    2017-01-01

    In this tutorial, you will learn how to define and open a call for abstracts. When defining a call for abstracts, you will be able to define settings related to the type of questions asked during a review of an abstract, select the users who will review the abstracts, decide when to open the call for abstracts, and more.

  17. On defining semantics of extended attribute grammars

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1980-01-01

    Knuth has introduced attribute grammars (AGs) as a tool to define the semanitcs of context-free languages. The use of AGs in connection with programming language definitions has mostly been to define the context-sensitive syntax of the language and to define a translation in code for a hypothetic...

  18. Languages for Software-Defined Networks

    Science.gov (United States)

    2013-02-01

    switches, firewalls, and middleboxes) with closed and proprietary configuration inter- faces. Software - Defined Networks ( SDN ) are poised to change...how- ever, have seen growing interest in software - defined networks ( SDNs ), in which a logically-centralized controller manages the packet-processing...switches, firewalls, and middleboxes) with closed and proprietary configuration interfaces. Software - Defined Networks ( SDN ) are poised to change this

  19. Lessons from a prototype geolocation problem

    DEFF Research Database (Denmark)

    Thygesen, Uffe Høgsbro; Nielsen, Anders

    2009-01-01

    This paper establishes simple and general expressions for the accuracy of geolocation, which may be obtained by optimal filtering of measurements front archival tags. We investigate an idealized geolocation problem where the animal performs a random walk. We derive simple closed-form expressions...... for the steady-state variance and for the characteristic time scale of the filter, i.e. the smoothing horizon. This leads to temporal and spatial scales defining the limit of resolution and explains the difference between what can be obtained for fast-moving and slow-moving animals. Using frequency......-domain methods, we consider the effect of adding additional sensors, and examine the substitution of the random walk model with anomalous diffusion, e.g. a Levy flight. We also discuss time variations in the accuracy near start and end of the time series, and due to holes in the data stream which e.g. arise...

  20. A model to compare a defined benefit pension fund with a defined contribution provident fund

    Directory of Open Access Journals (Sweden)

    J.M. Nevin

    2003-12-01

    Full Text Available During 1994 universities and certain other institutions were given the option of setting up private retirement funds as an alternative to the AIPF. Because of the underfundedness of the AIPF only a substantially reduced Actuarial Reserve Value could be transferred to the new fund on behalf of each member. Employees at these institutions had to make the difficult decision of whether to remain a member of the AIPF or to join a new fund. Several institutions created defined contribution funds as an alternative to the AIPF. In such funds the member carries the investment risk and most institutions felt the need to provide some form of top-up of the Transfer Value. A simple mathematical model is formulated to aid in the comparison of expected retirement benefits under the AIPF and a private fund and to investigate the management problem of distributing additional top-up funds in a fair manner amongst the various age groups within the fund.

  1. Sociale problemer

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter Verner

    Sociale problemer kan betragtes som selve udgangspunktet for socialt arbejde, hvor ambitionen er at råde bod på problemerne og sikre, at udsatte borgere får en bedre tilværelse. Det betyder også, at diskussionen af sociale problemer er afgørende for den sociale grundfaglighed. I denne bog sætter en...... række fagfolk på tværs af det danske socialfaglige felt fokus på sociale problemer. Det diskuteres, hvad vi overhovedet forstår ved sociale problemer, hvordan de opstår, hvilke konsekvenser de har, og ikke mindst hvordan man som fagprofessionel håndterer sociale problemer i det daglige arbejde. Bogen er...... skrevet som lærebog til professionsuddannelser, hvor sociale problemer udgør en dimension, bl.a. socialrådgiver-, pædagog- og sygeplejerskeuddannelserne....

  2. Schroedinger's variational method of quantization revisited

    International Nuclear Information System (INIS)

    Yasue, K.

    1980-01-01

    Schroedinger's original quantization procedure is revisited in the light of Nelson's stochastic framework of quantum mechanics. It is clarified why Schroedinger's proposal of a variational problem led us to a true description of quantum mechanics. (orig.)

  3. Solutions to variational inequalities of parabolic type

    Science.gov (United States)

    Zhu, Yuanguo

    2006-09-01

    The existence of strong solutions to a kind of variational inequality of parabolic type is investigated by the theory of semigroups of linear operators. As an application, an abstract semi permeable media problem is studied.

  4. On a class of general variational inequalities

    International Nuclear Information System (INIS)

    Siddiqi, A.H.

    1990-06-01

    The study of variational inequalities was initiated by the Italian Mathematician, Guido Stampacchia in the early 60's. Besides several other important problems of Physics and Engineering this theory has been applied to solve the problem of Elasticity with unilateral constraints. In this paper we introduce a new class of variational inequalities and study the existence and uniqueness of its solution. Error estimates, convergence of approximate solution and the penalty method are also discussed. (author). 25 refs

  5. Hearing Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Hearing ProblemsLoss in the ability to hear or discriminate ... This flow chart will help direct you if hearing loss is a problem for you or a ...

  6. Towards defining restlessness in individuals with dementia.

    Science.gov (United States)

    Regier, Natalie G; Gitlin, Laura N

    2017-05-01

    Most individuals with dementia develop significant behavioral problems. Restlessness is a behavioral symptom frequently endorsed by caregivers as distressing, yet is variably defined and measured. Lack of conceptual and operational clarity hinders an understanding of this common behavioral type, its prevalence, and development of effective interventions. We advance a systematic definition and understanding of restlessness from which to enhance reporting and intervention development. We reviewed the literature for existing definitions and measures of restlessness, identified common elements across existing definitions, assessed fit with relevant theoretical frameworks, and explored the relationship between restlessness and other behavioral symptoms in a data set of 272 community-dwelling persons with dementia. Twenty-five scales assessing restlessness were identified. Shared components included motor/neurological, psychiatric, and needs-based features. Exploratory analyses suggest that restlessness may co-occur primarily with argumentation, anxiety, waking the caregiver, delusions/hallucinations, and wandering. We propose that restlessness consists of three key attributes: diffuse motor activity or motion subject to limited control, non-productive or disorganized behavior, and subjective distress. Restlessness should be differentiated from and not confused with wandering or elopement, pharmacological side effects, a (non-dementia) mental or movement disorder, or behaviors occurring in the context of a delirium or at end-of-life. Restlessness appears to denote a distinct set of behaviors that have overlapping but non-equivalent features with other behavioral symptoms. We propose that it reflects a complex behavior involving three key characteristics. Understanding its specific manifestations and which components are present can enhance tailoring interventions to specific contexts of this multicomponent behavioral type.

  7. Traffic Policing in Dynamic Military Networks Using Software Defined Networking

    OpenAIRE

    Skappel, Hans Fredrik

    2016-01-01

    This thesis looks at how Software Defined Networking (SDN) can be used to provide traffic engineering and to police traffic in an Operational Military Network (OMN). SDN is a concept where the control plane is separated from the forwarding plane, and the control plane is capable of controlling forwarding plane elements located on multiple network nodes using the OpenFlow protocol. Specifically, we have discussed the problems in OMNs, and possible SDN approaches to mitigate the challenges. Bas...

  8. The mechanical response of lithographically defined break junctions

    International Nuclear Information System (INIS)

    Huisman, E. H.; Bakker, F. L.; Wees, B. J. van; Trouwborst, M. L.; Molen, S. J. van der

    2011-01-01

    We present an experimental study on the mechanical response of lithographically defined break junctions by measuring atomic chain formation, tunneling traces and Gundlach oscillations. The calibration factor, i.e., the ratio between the electrode movement and the bending of the substrate, is found to be 2.5 times larger than expected from a simple mechanical model. This result is consistent with previous finite-element calculations. Comparing different samples, the mechanical response is found to be similar for electrode separations >4 A. However, for smaller electrode separations significant sample-to-sample variations appear. These variations are ascribed to differences in the shape of the two electrodes on the atomic scale which cannot be controlled by the fabrication process.

  9. Problem Posing

    OpenAIRE

    Šilhavá, Marie

    2009-01-01

    This diploma thesis concentrates on problem posing from the students' point of view. Problem posing can be either seen as a teaching method which can be used in the class, or it can be used as a tool for researchers or teachers to assess the level of students' understanding of the topic. In my research, I compare three classes, one mathematics specialist class and two generalist classes, in their ability of problem posing. As an assessment tool it seemed that mathemathics specialists were abl...

  10. Seasonal variation in sports participation.

    Science.gov (United States)

    Schüttoff, Ute; Pawlowski, Tim

    2018-02-01

    This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

  11. Problem Based Learning

    DEFF Research Database (Denmark)

    de Graaff, Erik; Guerra, Aida

    , the key principles remain the same everywhere. Graaff & Kolmos (2003) identify the main PBL principles as follows: 1. Problem orientation 2. Project organization through teams or group work 3. Participant-directed 4. Experiental learning 5. Activity-based learning 6. Interdisciplinary learning and 7...... model and in general problem based and project based learning. We apply the principle of teach as you preach. The poster aims to outline the visitors’ workshop programme showing the results of some recent evaluations.......Problem-Based Learning (PBL) is an innovative method to organize the learning process in such a way that the students actively engage in finding answers by themselves. During the past 40 years PBL has evolved and diversified resulting in a multitude in variations in models and practices. However...

  12. Computational problems in engineering

    CERN Document Server

    Mladenov, Valeri

    2014-01-01

    This book provides readers with modern computational techniques for solving variety of problems from electrical, mechanical, civil and chemical engineering. Mathematical methods are presented in a unified manner, so they can be applied consistently to problems in applied electromagnetics, strength of materials, fluid mechanics, heat and mass transfer, environmental engineering, biomedical engineering, signal processing, automatic control and more.   • Features contributions from distinguished researchers on significant aspects of current numerical methods and computational mathematics; • Presents actual results and innovative methods that provide numerical solutions, while minimizing computing times; • Includes new and advanced methods and modern variations of known techniques that can solve difficult scientific problems efficiently.  

  13. Méthode intégro-variationnelle appliquée aux probèmes intérieur et extérieur avec surface libre de l'hydrodynamique linéaire Integro-Variational Method Applied to Indoor and Outdoor Problems with a Free Surface of Linear Hydrodinamics

    Directory of Open Access Journals (Sweden)

    Berhault C.

    2006-11-01

    Full Text Available Le but de cet article est de montrer que l'on peut appliquer une rintégro-variationnelle pour résoudre les problèmes intérieur (comportementliquide en milieu confiné et extérieur (diffraction-radiation de l'hydrodynamique linéaire. Une comparaison des résultats obtenus pour le problème intérieur dans Q les méthodes classiques : équation intégrale (singularités et formulation rationnelle (éléments finis, montre les avantages de cette méthode. The aim of this article is to show that an integro-variational method can be applied for solving interior (behavior of a liquid in a confined environment and exterior (diffraction-radiation problems of linear hydrodynamics. A comparison of the results obtained for the interior problem in IR2 with conventional methods, i.e. intégral équation (singularities and variational formulation (finite elements, shows the advantages of this method.

  14. Popular Problems

    DEFF Research Database (Denmark)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....

  15. Sleep Problems

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... 101 KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  16. Mouth Problems

    Science.gov (United States)

    ... such as sores, are very common. Follow this chart for more information about mouth problems in adults. ... cancers. See your dentist if sharp or rough teeth or dental work are causing irritation. Start OverDiagnosisThis ...

  17. Kidney Problems

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & Information The kidneys are two ... kidney (renal) diseases are called nephrologists . What are Kidney Diseases? For about one-third of older people, ...

  18. Are you better? A multi-centre study of patient-defined recovery from Complex Regional Pain Syndrome

    DEFF Research Database (Denmark)

    Llewellyn, A; McCabe, CS; Hibberd, Y

    2018-01-01

    Background: Complex Regional Pain Syndrome (CRPS) symptoms can significantly differ between patients, fluctuate over time, disappear or persist. This leads to problems in defining recovery and in evaluating the efficacy of therapeutic interventions. Objectives: To define recovery from the patient...

  19. Variational principles for nonpotential operators

    CERN Document Server

    Filippov, V M

    1989-01-01

    This book develops a variational method for solving linear equations with B-symmetric and B-positive operators and generalizes the method to nonlinear equations with nonpotential operators. The author carries out a constructive extension of the variational method to "nonvariational" equations (including parabolic equations) in classes of functionals which differ from the Euler-Lagrange functionals. In this connection, some new functions spaces are considered. Intended for mathematicians working in the areas of functional analysis and differential equations, this book would also prove useful for researchers in other areas and students in advanced courses who use variational methods in solving linear and nonlinear boundary value problems in continuum mechanics and theoretical physics.

  20. Solid mechanics a variational approach

    CERN Document Server

    Dym, Clive L

    2013-01-01

    Solid Mechanics: A Variational Approach, Augmented Edition presents a lucid and thoroughly developed approach to solid mechanics for students engaged in the study of elastic structures not seen in other texts currently on the market. This work offers a clear and carefully prepared exposition of variational techniques as they are applied to solid mechanics. Unlike other books in this field, Dym and Shames treat all the necessary theory needed for the study of solid mechanics and include extensive applications. Of particular note is the variational approach used in developing consistent structural theories and in obtaining exact and approximate solutions for many problems.  Based on both semester and year-long courses taught to undergraduate seniors and graduate students, this text is geared for programs in aeronautical, civil, and mechanical engineering, and in engineering science. The authors’ objective is two-fold: first, to introduce the student to the theory of structures (one- and two-dimensional) as ...

  1. Variational approach in transport theory

    International Nuclear Information System (INIS)

    Panta Pazos, R.; Tullio de Vilhena, M.

    2004-01-01

    In this work we present a variational approach to some methods to solve transport problems of neutral particles. We consider a convex domain X (for example the geometry of a slab, or a convex set in the plane, or a convex bounded set in the space) and we use discrete ordinates quadrature to get a system of differential equations derived from the neutron transport equation. The boundary conditions are vacuum for a subset of the boundary, and of specular reflection for the complementary subset of the boundary. Recently some different approximation methods have been presented to solve these transport problems. We introduce in this work the adjoint equations and the conjugate functions obtained by means of the variational approach. First we consider the general formulation, and then some numerical methods such as spherical harmonics and spectral collocation method. (authors)

  2. Variational approach in transport theory

    Energy Technology Data Exchange (ETDEWEB)

    Panta Pazos, R. [Nucler Engineering Department, UFRGS, Porto-Alegre (Brazil); Tullio de Vilhena, M. [Institute of Mathematics, UFRGS, Porto-Alegre (Brazil)

    2004-07-01

    In this work we present a variational approach to some methods to solve transport problems of neutral particles. We consider a convex domain X (for example the geometry of a slab, or a convex set in the plane, or a convex bounded set in the space) and we use discrete ordinates quadrature to get a system of differential equations derived from the neutron transport equation. The boundary conditions are vacuum for a subset of the boundary, and of specular reflection for the complementary subset of the boundary. Recently some different approximation methods have been presented to solve these transport problems. We introduce in this work the adjoint equations and the conjugate functions obtained by means of the variational approach. First we consider the general formulation, and then some numerical methods such as spherical harmonics and spectral collocation method. (authors)

  3. 22 CFR 92.36 - Authentication defined.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Authentication defined. 92.36 Section 92.36... Notarial Acts § 92.36 Authentication defined. An authentication is a certification of the genuineness of... recognized in another jurisdiction. Documents which may require authentication include legal instruments...

  4. A definability theorem for first order logic

    NARCIS (Netherlands)

    Butz, C.; Moerdijk, I.

    1997-01-01

    In this paper we will present a definability theorem for first order logic This theorem is very easy to state and its proof only uses elementary tools To explain the theorem let us first observe that if M is a model of a theory T in a language L then clearly any definable subset S M ie a subset S

  5. Dilution Confusion: Conventions for Defining a Dilution

    Science.gov (United States)

    Fishel, Laurence A.

    2010-01-01

    Two conventions for preparing dilutions are used in clinical laboratories. The first convention defines an "a:b" dilution as "a" volumes of solution A plus "b" volumes of solution B. The second convention defines an "a:b" dilution as "a" volumes of solution A diluted into a final volume of "b". Use of the incorrect dilution convention could affect…

  6. Defining Hardwood Veneer Log Quality Attributes

    Science.gov (United States)

    Jan Wiedenbeck; Michael Wiemann; Delton Alderman; John Baumgras; William Luppold

    2004-01-01

    This publication provides a broad spectrum of information on the hardwood veneer industry in North America. Veneer manufacturers and their customers impose guidelines in specifying wood quality attributes that are very discriminating but poorly defined (e.g., exceptional color, texture, and/or figure characteristics). To better understand and begin to define the most...

  7. Sleep Health: Can We Define It? Does It Matter?

    Science.gov (United States)

    Buysse, Daniel J.

    2014-01-01

    Good sleep is essential to good health. Yet for most of its history, sleep medicine has focused on the definition, identification, and treatment of sleep problems. Sleep health is a term that is infrequently used and even less frequently defined. It is time for us to change this. Indeed, pressures in the research, clinical, and regulatory environments require that we do so. The health of populations is increasingly defined by positive attributes such as wellness, performance, and adaptation, and not merely by the absence of disease. Sleep health can be defined in such terms. Empirical data demonstrate several dimensions of sleep that are related to health outcomes, and that can be measured with self-report and objective methods. One suggested definition of sleep health and a description of self-report items for measuring it are provided as examples. The concept of sleep health synergizes with other health care agendas, such as empowering individuals and communities, improving population health, and reducing health care costs. Promoting sleep health also offers the field of sleep medicine new research and clinical opportunities. In this sense, defining sleep health is vital not only to the health of populations and individuals, but also to the health of sleep medicine itself. Citation: Buysse DJ. Sleep health: can we define it? Does it matter? SLEEP 2014;37(1):9-17. PMID:24470692

  8. Monolingual Lexicography and Linguistic Variation in Shona

    African Journals Online (AJOL)

    R.B. Ruthven

    Abstract: This article focuses on the problems lexicographers of monolingual dictionaries face when dealing with a language characterised by differences associated with geographical variation. The article specifically seeks to explore problems with which Shona lexicographers are confronted when working on monolingual ...

  9. A unified framework of descent algorithms for nonlinear programs and variational inequalities

    International Nuclear Information System (INIS)

    Patriksson, M.

    1993-01-01

    We present a framework of algorithms for the solution of continuous optimization and variational inequality problems. In the general algorithm, a search direction finding auxiliary problems is obtained by replacing the original cost function with an approximating monotone cost function. The proposed framework encompasses algorithm classes presented earlier by Cohen, Dafermos, Migdalas, and Tseng, and includes numerous descent and successive approximation type methods, such as Newton methods, Jacobi and Gauss-Siedel type decomposition methods for problems defined over Cartesian product sets, and proximal point methods, among others. The auxiliary problem of the general algorithm also induces equivalent optimization reformulation and descent methods for asymmetric variational inequalities. We study the convergence properties of the general algorithm when applied to unconstrained optimization, nondifferentiable optimization, constrained differentiable optimization, and variational inequalities; the emphasis of the convergence analyses is placed on basic convergence results, convergence using different line search strategies and truncated subproblem solutions, and convergence rate results. This analysis offer a unification of known results; moreover, it provides strengthenings of convergence results for many existing algorithms, and indicates possible improvements of their realizations. 482 refs

  10. Variation and Mathematics Pedagogy

    Science.gov (United States)

    Leung, Allen

    2012-01-01

    This discussion paper put forwards variation as a theme to structure mathematical experience and mathematics pedagogy. Patterns of variation from Marton's Theory of Variation are understood and developed as types of variation interaction that enhance mathematical understanding. An idea of a discernment unit comprising mutually supporting variation…

  11. Defining Compensable Injury in Biomedical Research.

    Science.gov (United States)

    Larkin, Megan E

    2015-01-01

    Biomedical research provides a core social good by enabling medical progress. In the twenty-first century alone, this includes reducing transmission of HIV/AIDS, developing innovative therapies for cancer patients, and exploring the possibilities of personalized medicine. In order to continue to advance medical science, research relies on the voluntary participation of human subjects. Because research is inherently uncertain, unintended harm is an inevitable part of the research enterprise. Currently, injured research participants in the United States must turn to the “litigation lottery” of the tort system in search of compensation. This state of affairs fails research participants, who are too often left uncompensated for devastating losses, and makes the United States an outlier in the international community. In spite of forty years’ worth of Presidential Commissions and other respected voices calling for the development of a no-fault compensation system, no progress has been made to date. One of the reasons for this lack of progress is the failure to develop a coherent ethical basis for an obligation to provide compensation for research related injuries. This problem is exacerbated by the lack of a clear definition of “compensable injury” in the biomedical research context. This article makes a number of important contributions to the scholarship in this growing field. To begin, it examines compensation systems already in existence and concludes that there are four main definitional elements that must be used to define “compensable injury.” Next, it examines the justifications that have been put forth as the basis for an ethical obligation to provide compensation, and settles on retrospective nonmaleficence and distributive and compensatory justice as the most salient and persuasive. Finally, it uses the regulatory elements and the justifications discussed in the first two sections to develop a well-rounded definition of “compensable injury

  12. On the notion of Jacobi fields in constrained calculus of variations

    Directory of Open Access Journals (Sweden)

    Massa Enrico

    2016-12-01

    Full Text Available In variational calculus, the minimality of a given functional under arbitrary deformations with fixed end-points is established through an analysis of the so called second variation. In this paper, the argument is examined in the context of constrained variational calculus, assuming piecewise differentiable extremals, commonly referred to as extremaloids. The approach relies on the existence of a fully covariant representation of the second variation of the action functional, based on a family of local gauge transformations of the original Lagrangian and on a set of scalar attributes of the extremaloid, called the corners' strengths [16]. In dis- cussing the positivity of the second variation, a relevant role is played by the Jacobi fields, defined as infinitesimal generators of 1-parameter groups of diffeomorphisms preserving the extremaloids. Along a piecewise differentiable extremal, these fields are generally discontinuous across the corners. A thorough analysis of this point is presented. An alternative characterization of the Jacobi fields as solutions of a suitable accessory variational problem is established.

  13. Calculus problems

    CERN Document Server

    Baronti, Marco; van der Putten, Robertus; Venturi, Irene

    2016-01-01

    This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...

  14. Bilayer graphene quantum dot defined by topgates

    Energy Technology Data Exchange (ETDEWEB)

    Müller, André; Kaestner, Bernd; Hohls, Frank; Weimann, Thomas; Pierz, Klaus; Schumacher, Hans W., E-mail: hans.w.schumacher@ptb.de [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany)

    2014-06-21

    We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK, the conductance underneath the grounded gates is suppressed, which we attribute to nearest neighbour hopping and strain-induced piezoelectric fields. The gate-layout can thus be used to define resistive regions by tuning into the corresponding temperature range. We use this method to define a quantum dot structure in bilayer graphene showing Coulomb blockade oscillations consistent with the gate layout.

  15. Total variation-based neutron computed tomography

    Science.gov (United States)

    Barnard, Richard C.; Bilheux, Hassina; Toops, Todd; Nafziger, Eric; Finney, Charles; Splitter, Derek; Archibald, Rick

    2018-05-01

    We perform the neutron computed tomography reconstruction problem via an inverse problem formulation with a total variation penalty. In the case of highly under-resolved angular measurements, the total variation penalty suppresses high-frequency artifacts which appear in filtered back projections. In order to efficiently compute solutions for this problem, we implement a variation of the split Bregman algorithm; due to the error-forgetting nature of the algorithm, the computational cost of updating can be significantly reduced via very inexact approximate linear solvers. We present the effectiveness of the algorithm in the significantly low-angular sampling case using synthetic test problems as well as data obtained from a high flux neutron source. The algorithm removes artifacts and can even roughly capture small features when an extremely low number of angles are used.

  16. Optimal Control of Evolution Mixed Variational Inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Alduncin, Gonzalo, E-mail: alduncin@geofisica.unam.mx [Universidad Nacional Autónoma de México, Departamento de Recursos Naturales, Instituto de Geofísica (Mexico)

    2013-12-15

    Optimal control problems of primal and dual evolution mixed variational inclusions, in reflexive Banach spaces, are studied. The solvability analysis of the mixed state systems is established via duality principles. The optimality analysis is performed in terms of perturbation conjugate duality methods, and proximation penalty-duality algorithms to mixed optimality conditions are further presented. Applications to nonlinear diffusion constrained problems as well as quasistatic elastoviscoplastic bilateral contact problems exemplify the theory.

  17. Optimal Control of Evolution Mixed Variational Inclusions

    International Nuclear Information System (INIS)

    Alduncin, Gonzalo

    2013-01-01

    Optimal control problems of primal and dual evolution mixed variational inclusions, in reflexive Banach spaces, are studied. The solvability analysis of the mixed state systems is established via duality principles. The optimality analysis is performed in terms of perturbation conjugate duality methods, and proximation penalty-duality algorithms to mixed optimality conditions are further presented. Applications to nonlinear diffusion constrained problems as well as quasistatic elastoviscoplastic bilateral contact problems exemplify the theory

  18. Defining the role of common variation in the genomic and biological architecture of adult human height

    NARCIS (Netherlands)

    A.R. Wood (Andrew); T. Esko (Tõnu); J. Yang (Jian); S. Vedantam (Sailaja); T.H. Pers (Tune); S. Gustafsson (Stefan); A.Y. Chu (Audrey Y); K. Estrada Gil (Karol); J. Luan; Z. Kutalik; N. Amin (Najaf); M.L. Buchkovich (Martin); D.C. Croteau-Chonka (Damien); F.R. Day (Felix); Y. Duan (Yanan); M. Fall (Magnus); R.S.N. Fehrmann (Rudolf); T. Ferreira (Teresa); A.U. Jackson (Anne); J. Karjalainen (Juha); K.S. Lo (Ken Sin); A. Locke (Adam); R. Mägi (Reedik); E. Mihailov (Evelin); E. Porcu (Eleonora); J.C. Randall (Joshua); A. Scherag (Andre); A.A.E. Vinkhuyzen (Anna A.); H.J. Westra (Harm-Jan); T.W. Winkler (Thomas W.); T. Workalemahu (Tsegaselassie); J.H. Zhao (Jing Hua); D. Absher (Devin); E. Albrecht (Eva); J. Baron (Jeffrey); M. Beekman (Marian); A. Demirkan (Ayşe); G.B. Ehret (Georg); B. Feenstra; M.F. Feitosa (Mary Furlan); K. Fischer (Krista); R.M. Fraser (Ross); A. Goel (Anuj); J. Gong (Jian); A.E. Justice (Anne); S. Kanoni (Stavroula); M.E. Kleber (Marcus); K. Kristiansson (Kati); U. Lim (Unhee); V. Lotay (Vaneet); J.C. Lui (Julian C); M. Mangino (Massimo); I.M. Leach (Irene Mateo); M.C. Medina-Gomez (Carolina); M.A. Nalls (Michael); A.S. Dimas (Antigone); C. Palmer (Cameron); D. Pasko (Dorota); S. Pechlivanis (Sonali); I. Prokopenko (Inga); J.S. Ried (Janina); S. Ripke (Stephan); D. Shungin (Dmitry); A. Stancáková (Alena); R.J. Strawbridge (Rona); Y.J. Sung (Yun Ju); T. Tanaka (Toshiko); A. Teumer (Alexander); S. Trompet (Stella); S.W. Van Der Laan (Sander W.); J. van Setten (Jessica); J.V. van Vliet-Ostaptchouk (Jana); Z. Wang (Zhaoming); L. Yengo (Loic); W. Zhang (Weihua); U. Afzal (Uzma); J. Ärnlöv (Johan); G.M. Arscott (Gillian M.); S. Bandinelli (Stefania); A. Barrett (Angela); C. Bellis (Claire); A.J. Bennett (Amanda); C. Berne (Christian); M. Blüher (Matthias); J.L. Bolton (Jennifer); Y. Böttcher (Yvonne); H.A. Boyd; M. Bruinenberg (M.); B.M. Buckley (Brendan M.); S. Buyske (Steven); I.H. Caspersen (Ida H.); P.S. Chines (Peter); R. Clarke (Robert); S. Claudi-Boehm (Simone); M.N. Cooper (Matthew); E.W. Daw (E Warwick); P.A. De Jong (Pim A); J. Deelen (Joris); G. Delgado; J.C. Denny (Josh C); R.A.M. Dhonukshe-Rutten (Rosalie); M. Dimitriou (Maria); A.S.F. Doney (Alex); M. Dörr (Marcus); N. Eklund (Niina); E. Eury (Elodie); L. Folkersen (Lasse); M. Garcia (Melissa); F. Geller (Frank); V. Giedraitis (Vilmantas); A. Go (Attie); H. Grallert (Harald); T.B. Grammer (Tanja B); J. Gräßler (Jürgen); H. Grönberg (Henrik); L.C.P.G.M. de Groot (Lisette); C.J. Groves (Christopher J.); J. Haessler (Jeff); P. Hall (Per); T. Haller (Toomas); G. Hallmans (Göran); M. Hannemann (Mario); C.A. Hartman (Catharina); M. Hassinen (Maija); C. Hayward (Caroline); N.L. Heard-Costa (Nancy); Q. Helmer (Quinta); G. Hemani; A.K. Henders (Anjali); H.L. Hillege (Hans); M.A. Hlatky (Mark); W. Hoffmann (Wolfgang); P. Hoffmann (Per); O.L. Holmen (Oddgeir); J.J. Houwing-Duistermaat (Jeanine); T. Illig (Thomas); A. Isaacs (Aaron); A.L. James (Alan); J. Jeff (Janina); B. Johansen (Berit); A. Johansson (Åsa); G.J. Jolley (Jason); T. Juliusdottir (Thorhildur); M.J. Junttila (Juhani); M.M.L. Kho (Marcia); L. Kinnunen (Leena); N. Klopp (Norman); T. Kocher; W. Kratzer (Wolfgang); P. Lichtner (Peter); L. Lind (Lars); J. Lindström (Jaana); S. Lobbens (Stéphane); M. Lorentzon (Mattias); Y. Lu (Yingchang); V. Lyssenko (Valeriya); P.K. Magnusson (Patrik); A. Mahajan (Anubha); M. Maillard (Marc); W.L. McArdle (Wendy); C.A. McKenzie (Colin A.); S. McLachlan (Stela); P.J. McLaren (Paul J); C. Menni (Cristina); S. Merger (Sigrun); L. Milani (Lili); A. Moayyeri (Alireza); K.L. Monda (Keri); M.A. Morken (Mario); G. Müller (Gabriele); M. Müller-Nurasyid (Martina); A.W. Musk (Arthur); N. Narisu (Narisu); M. Nauck (Matthias); I.M. Nolte (Ilja M.); M.M. Nöthen (Markus); L. Oozageer (Laticia); S. Pilz (Stefan); N.W. Rayner (Nigel William); F. Renström (Frida); N.R. Robertson (Neil R.); L.M. Rose (Lynda M.); R. Roussel (Ronan); S. Sanna (Serena); H. Scharnagl (Hubert); S. Scholtens (Salome); F.R. Schumacher (Fredrick R); H. Schunkert (Heribert); R.A. Scott (Robert); J.S. Sehmi (Joban); T. Seufferlein (Thomas); J. Shi (Jianxin); K. Silventoinen (Karri); J.H. Smit (Johannes); G.D. Smith; J. Smolonska (Joanna); A. Stanton (Alice); K. Stirrups (Kathy); D.J. Stott (David J); H.M. Stringham (Heather); J. Sundstrom (Johan); M. Swertz (Morris); A.C. Syvanen; B. Tayo (Bamidele); G. Thorleifsson (Gudmar); J.P. Tyrer (Jonathan); S. Van Dijk (Suzanne); N.M. van Schoor (Natasja); N. van der Velde (Nathalie); D. van Heemst (Diana); F.V.A. Van Oort (Floor V A); S.H.H.M. Vermeulen (Sita); N. Verweij (Niek); J.M. Vonk (Judith M); L. Waite (Lindsay); M. Waldenberger (Melanie); R. Wennauer (Roman); L.R. Wilkens (Lynne R.); C. Willenborg (Christina); T. Wilsgaard (Tom); M.K. Wojczynski (Mary ); A. Wong (Andrew); A. Wright (Alan); Q. Zhang (Qunyuan); D. Arveiler (Dominique); S.J.L. Bakker (Stephan); J. Beilby (John); R.N. Bergman (Richard); S.M. Bergmann (Sven); R. Biffar; J. Blangero (John); D.I. Boomsma (Dorret); S.R. Bornstein (Stefan R.); P. Bovet (Pascal); P. Brambilla (Paolo); M.J. Brown (Morris); H. Campbell (Harry); M. Caulfield (Mark); A. Chakravarti (Aravinda); F.S. Collins (Francis); D.C. Crawford (Dana); L.A. Cupples (Adrienne); J. Danesh (John); U. de Faire (Ulf); H.M. den Ruijter (Hester ); R. Erbel (Raimund); J. Erdmann (Jeanette); J. Eriksson; M. Farrall (Martin); E. Ferrannini (Ele); J. Ferrieres (Jean); I. Ford; N.G. Forouhi (Nita); T. Forrester (Terrence); R.T. Gansevoort (Ron); P.V. Gejman (Pablo); C. Gieger (Christian); A. Golay (Alain); R.F. Gottesman (Rebecca); V. Gudnason (Vilmundur); U. Gyllensten (Ulf); D.W. Haas (David W); A.S. Hall (Alistair); T.B. Harris (Tamara); A.T. Hattersley (Andrew); A.C. Heath (Andrew C); C. Hengstenberg (Christian); A.A. Hicks (Andrew); L.A. Hindorff (Lucia A); A. Hingorani (Aroon); A. Hofman (Albert); G.K. Hovingh (Kees); S.E. Humphries (Steve E.); S.C. Hunt (Steven); E. Hypponen (Elina); K.B. Jacobs (Kevin); M.-R. Jarvelin (Marjo-Riitta); P. Jousilahti (Pekka); A. Jula (Antti); J. Kaprio (Jaakko); J.J.P. Kastelein (John); M.H. Kayser (Manfred); F. Kee (Frank); S. Keinanen-Kiukaanniemi (Sirkka); L.A.L.M. Kiemeney (Bart); J.S. Kooner (Jaspal S.); C. Kooperberg (Charles); S. Koskinen (Seppo); P. Kovacs (Peter); A. Kraja (Aldi); M. Kumari (Meena); J. Kuusisto (Johanna); T.A. Lakka (Timo); C. Langenberg (Claudia); L. Le Marchand (Loic); T. Lehtimäki (Terho); S. Lupoli (Sara); P.A. Madden; S. Männistö (Satu); P. Manunta (Paolo); A. Marette (Andre'); T.C. Matise (Tara C.); B. McKnight (Barbara); T. Meitinger (Thomas); F.L. Moll (Frans); G.W. Montgomery (Grant W.); A.D. Morris (Andrew); A.P. Morris (Andrew); J.C. Murray (Jeffrey); M. Nelis (Mari); C. Ohlsson (Claes); A.J. Oldehinkel (Albertine); K.K. Ong (Ken K.); W.H. Ouwehand (Willem); G. Pasterkamp (Gerard); A. Peters (Annette); P.P. Pramstaller (Peter Paul); J.F. Price (Jackie F.); L. Qi (Lu); O. Raitakari (Olli); T. Rankinen (Tuomo); D.C. Rao (Dabeeru C.); T.K. Rice (Treva K.); M.D. Ritchie (Marylyn D.); I. Rudan (Igor); V. Salomaa (Veikko); N.J. Samani (Nilesh); J. Saramies (Jouko); M.A. Sarzynski (Mark A.); P.E.H. Schwarz (Peter E. H.); S. Sebert (Sylvain); P. Sever (Peter); A.R. Shuldiner (Alan); J. Sinisalo (Juha); V. Steinthorsdottir (Valgerdur); R.P. Stolk; J.-C. Tardif (Jean-Claude); A. Tönjes (Anke); A. Tremblay (Angelo); E. Tremoli (Elena); J. Virtamo (Jarmo); M.-C. Vohl (Marie-Claude); P. Amouyel (Philippe); F.W. Asselbergs (Folkert W.); T.L. Assimes (Themistocles); M. Bochud (Murielle); B.O. Boehm (Bernhard); E.A. Boerwinkle (Eric); E.P. Bottinger (Erwin P.); C. Bouchard (Claude); S. Cauchi (Stéphane); J.C. Chambers (John C.); S.J. Chanock (Stephen); R.S. Cooper (Richard S.); P.I.W. de Bakker (Paul); G.V. Dedoussis (George); L. Ferrucci (Luigi); P.W. Franks; P. Froguel (Philippe); L. Groop (Leif); C.A. Haiman (Christopher); A. Hamsten (Anders); M.G. Hayes (M. Geoffrey); J. Hui (Jennie); D. Hunter (David); K. Hveem (Kristian); J.W. Jukema (Jan Wouter); R.C. Kaplan (Robert); M. Kivimaki (Mika); D. Kuh (Diana); M. Laakso (Markku); Y. Liu (YongMei); N.G. Martin (Nicholas); W. März (Winfried); M. Melbye (Mads); S. Moebus (Susanne); P. Munroe (Patricia); I. Njølstad (Inger); B.A. Oostra (Ben); C.N.A. Palmer (Colin); N.L. Pedersen (Nancy L.); M. Perola (Markus); L. Perusse (Louis); U. Peters (Ulrike); J.E. Powell (Joseph); C. Power (Christine); T. Quertermous (Thomas); R. Rauramaa (Rainer); E. Reinmaa (Eva); P.M. Ridker (Paul); F. Rivadeneira Ramirez (Fernando); J.I. Rotter (Jerome I.); T. Saaristo (Timo); D. Saleheen; D. Schlessinger (David); P.E. Slagboom (P Eline); H. Snieder (Harold); T.D. Spector (Timothy); K. Strauch (Konstantin); M. Stumvoll (Michael); J. Tuomilehto (Jaakko); M. Uusitupa (Matti); P. van der Harst (Pim); H. Völzke (Henry); M. Walker (Mark); N.J. Wareham (Nick); H. Watkins (Hugh); H.E. Wichmann (Heinz Erich); J.F. Wilson (James F); P. Zanen (Pieter); P. Deloukas (Panagiotis); I.M. Heid (Iris); C.M. Lindgren (Cecilia); K.L. Mohlke (Karen); E.K. Speliotes (Elizabeth); U. Thorsteinsdottir (Unnur); I.E. Barroso (Inês); C.S. Fox (Caroline S.); K.E. North (Kari); D.P. Strachan (David P.); J.S. Beckmann (Jacques); S.I. Berndt (Sonja); M. Boehnke (Michael); I.B. Borecki (Ingrid); M.I. McCarthy (Mark); A. Metspalu (Andres); J-A. Zwart (John-Anker); A.G. Uitterlinden (André); C.M. van Duijn (Cornelia); L. Franke (Lude); C.J. Willer (Cristen); A. Price (Alkes); G. Lettre (Guillaume); R.J.F. Loos (Ruth); M.N. Weedon (Michael); E. Ingelsson (Erik); J.R. O´Connell; G.R. Abecasis (Gonçalo); D.I. Chasman (Daniel); D. Anderson (Denise); M.E. Goddard (Michael); P.M. Visscher (Peter); J.N. Hirschhorn (Joel); T.M. Frayling (Timothy)

    2014-01-01

    textabstractUsing genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated

  19. Defining the role of common variation in the genomic and biological architecture of adult human height.

    Science.gov (United States)

    Wood, Andrew R; Esko, Tonu; Yang, Jian; Vedantam, Sailaja; Pers, Tune H; Gustafsson, Stefan; Chu, Audrey Y; Estrada, Karol; Luan, Jian'an; Kutalik, Zoltán; Amin, Najaf; Buchkovich, Martin L; Croteau-Chonka, Damien C; Day, Felix R; Duan, Yanan; Fall, Tove; Fehrmann, Rudolf; Ferreira, Teresa; Jackson, Anne U; Karjalainen, Juha; Lo, Ken Sin; Locke, Adam E; Mägi, Reedik; Mihailov, Evelin; Porcu, Eleonora; Randall, Joshua C; Scherag, André; Vinkhuyzen, Anna A E; Westra, Harm-Jan; Winkler, Thomas W; Workalemahu, Tsegaselassie; Zhao, Jing Hua; Absher, Devin; Albrecht, Eva; Anderson, Denise; Baron, Jeffrey; Beekman, Marian; Demirkan, Ayse; Ehret, Georg B; Feenstra, Bjarke; Feitosa, Mary F; Fischer, Krista; Fraser, Ross M; Goel, Anuj; Gong, Jian; Justice, Anne E; Kanoni, Stavroula; Kleber, Marcus E; Kristiansson, Kati; Lim, Unhee; Lotay, Vaneet; Lui, Julian C; Mangino, Massimo; Mateo Leach, Irene; Medina-Gomez, Carolina; Nalls, Michael A; Nyholt, Dale R; Palmer, Cameron D; Pasko, Dorota; Pechlivanis, Sonali; Prokopenko, Inga; Ried, Janina S; Ripke, Stephan; Shungin, Dmitry; Stancáková, Alena; Strawbridge, Rona J; Sung, Yun Ju; Tanaka, Toshiko; Teumer, Alexander; Trompet, Stella; van der Laan, Sander W; van Setten, Jessica; Van Vliet-Ostaptchouk, Jana V; Wang, Zhaoming; Yengo, Loïc; Zhang, Weihua; Afzal, Uzma; Arnlöv, Johan; Arscott, Gillian M; Bandinelli, Stefania; Barrett, Amy; Bellis, Claire; Bennett, Amanda J; Berne, Christian; Blüher, Matthias; Bolton, Jennifer L; Böttcher, Yvonne; Boyd, Heather A; Bruinenberg, Marcel; Buckley, Brendan M; Buyske, Steven; Caspersen, Ida H; Chines, Peter S; Clarke, Robert; Claudi-Boehm, Simone; Cooper, Matthew; Daw, E Warwick; De Jong, Pim A; Deelen, Joris; Delgado, Graciela; Denny, Josh C; Dhonukshe-Rutten, Rosalie; Dimitriou, Maria; Doney, Alex S F; Dörr, Marcus; Eklund, Niina; Eury, Elodie; Folkersen, Lasse; Garcia, Melissa E; Geller, Frank; Giedraitis, Vilmantas; Go, Alan S; Grallert, Harald; Grammer, Tanja B; Gräßler, Jürgen; Grönberg, Henrik; de Groot, Lisette C P G M; Groves, Christopher J; Haessler, Jeffrey; Hall, Per; Haller, Toomas; Hallmans, Goran; Hannemann, Anke; Hartman, Catharina A; Hassinen, Maija; Hayward, Caroline; Heard-Costa, Nancy L; Helmer, Quinta; Hemani, Gibran; Henders, Anjali K; Hillege, Hans L; Hlatky, Mark A; Hoffmann, Wolfgang; Hoffmann, Per; Holmen, Oddgeir; Houwing-Duistermaat, Jeanine J; Illig, Thomas; Isaacs, Aaron; James, Alan L; Jeff, Janina; Johansen, Berit; Johansson, Åsa; Jolley, Jennifer; Juliusdottir, Thorhildur; Junttila, Juhani; Kho, Abel N; Kinnunen, Leena; Klopp, Norman; Kocher, Thomas; Kratzer, Wolfgang; Lichtner, Peter; Lind, Lars; Lindström, Jaana; Lobbens, Stéphane; Lorentzon, Mattias; Lu, Yingchang; Lyssenko, Valeriya; Magnusson, Patrik K E; Mahajan, Anubha; Maillard, Marc; McArdle, Wendy L; McKenzie, Colin A; McLachlan, Stela; McLaren, Paul J; Menni, Cristina; Merger, Sigrun; Milani, Lili; Moayyeri, Alireza; Monda, Keri L; Morken, Mario A; Müller, Gabriele; Müller-Nurasyid, Martina; Musk, Arthur W; Narisu, Narisu; Nauck, Matthias; Nolte, Ilja M; Nöthen, Markus M; Oozageer, Laticia; Pilz, Stefan; Rayner, Nigel W; Renstrom, Frida; Robertson, Neil R; Rose, Lynda M; Roussel, Ronan; Sanna, Serena; Scharnagl, Hubert; Scholtens, Salome; Schumacher, Fredrick R; Schunkert, Heribert; Scott, Robert A; Sehmi, Joban; Seufferlein, Thomas; Shi, Jianxin; Silventoinen, Karri; Smit, Johannes H; Smith, Albert Vernon; Smolonska, Joanna; Stanton, Alice V; Stirrups, Kathleen; Stott, David J; Stringham, Heather M; Sundström, Johan; Swertz, Morris A; Syvänen, Ann-Christine; Tayo, Bamidele O; Thorleifsson, Gudmar; Tyrer, Jonathan P; van Dijk, Suzanne; van Schoor, Natasja M; van der Velde, Nathalie; van Heemst, Diana; van Oort, Floor V A; Vermeulen, Sita H; Verweij, Niek; Vonk, Judith M; Waite, Lindsay L; Waldenberger, Melanie; Wennauer, Roman; Wilkens, Lynne R; Willenborg, Christina; Wilsgaard, Tom; Wojczynski, Mary K; Wong, Andrew; Wright, Alan F; Zhang, Qunyuan; Arveiler, Dominique; Bakker, Stephan J L; Beilby, John; Bergman, Richard N; Bergmann, Sven; Biffar, Reiner; Blangero, John; Boomsma, Dorret I; Bornstein, Stefan R; Bovet, Pascal; Brambilla, Paolo; Brown, Morris J; Campbell, Harry; Caulfield, Mark J; Chakravarti, Aravinda; Collins, Rory; Collins, Francis S; Crawford, Dana C; Cupples, L Adrienne; Danesh, John; de Faire, Ulf; den Ruijter, Hester M; Erbel, Raimund; Erdmann, Jeanette; Eriksson, Johan G; Farrall, Martin; Ferrannini, Ele; Ferrières, Jean; Ford, Ian; Forouhi, Nita G; Forrester, Terrence; Gansevoort, Ron T; Gejman, Pablo V; Gieger, Christian; Golay, Alain; Gottesman, Omri; Gudnason, Vilmundur; Gyllensten, Ulf; Haas, David W; Hall, Alistair S; Harris, Tamara B; Hattersley, Andrew T; Heath, Andrew C; Hengstenberg, Christian; Hicks, Andrew A; Hindorff, Lucia A; Hingorani, Aroon D; Hofman, Albert; Hovingh, G Kees; Humphries, Steve E; Hunt, Steven C; Hypponen, Elina; Jacobs, Kevin B; Jarvelin, Marjo-Riitta; Jousilahti, Pekka; Jula, Antti M; Kaprio, Jaakko; Kastelein, John J P; Kayser, Manfred; Kee, Frank; Keinanen-Kiukaanniemi, Sirkka M; Kiemeney, Lambertus A; Kooner, Jaspal S; Kooperberg, Charles; Koskinen, Seppo; Kovacs, Peter; Kraja, Aldi T; Kumari, Meena; Kuusisto, Johanna; Lakka, Timo A; Langenberg, Claudia; Le Marchand, Loic; Lehtimäki, Terho; Lupoli, Sara; Madden, Pamela A F; Männistö, Satu; Manunta, Paolo; Marette, André; Matise, Tara C; McKnight, Barbara; Meitinger, Thomas; Moll, Frans L; Montgomery, Grant W; Morris, Andrew D; Morris, Andrew P; Murray, Jeffrey C; Nelis, Mari; Ohlsson, Claes; Oldehinkel, Albertine J; Ong, Ken K; Ouwehand, Willem H; Pasterkamp, Gerard; Peters, Annette; Pramstaller, Peter P; Price, Jackie F; Qi, Lu; Raitakari, Olli T; Rankinen, Tuomo; Rao, D C; Rice, Treva K; Ritchie, Marylyn; Rudan, Igor; Salomaa, Veikko; Samani, Nilesh J; Saramies, Jouko; Sarzynski, Mark A; Schwarz, Peter E H; Sebert, Sylvain; Sever, Peter; Shuldiner, Alan R; Sinisalo, Juha; Steinthorsdottir, Valgerdur; Stolk, Ronald P; Tardif, Jean-Claude; Tönjes, Anke; Tremblay, Angelo; Tremoli, Elena; Virtamo, Jarmo; Vohl, Marie-Claude; Amouyel, Philippe; Asselbergs, Folkert W; Assimes, Themistocles L; Bochud, Murielle; Boehm, Bernhard O; Boerwinkle, Eric; Bottinger, Erwin P; Bouchard, Claude; Cauchi, Stéphane; Chambers, John C; Chanock, Stephen J; Cooper, Richard S; de Bakker, Paul I W; Dedoussis, George; Ferrucci, Luigi; Franks, Paul W; Froguel, Philippe; Groop, Leif C; Haiman, Christopher A; Hamsten, Anders; Hayes, M Geoffrey; Hui, Jennie; Hunter, David J; Hveem, Kristian; Jukema, J Wouter; Kaplan, Robert C; Kivimaki, Mika; Kuh, Diana; Laakso, Markku; Liu, Yongmei; Martin, Nicholas G; März, Winfried; Melbye, Mads; Moebus, Susanne; Munroe, Patricia B; Njølstad, Inger; Oostra, Ben A; Palmer, Colin N A; Pedersen, Nancy L; Perola, Markus; Pérusse, Louis; Peters, Ulrike; Powell, Joseph E; Power, Chris; Quertermous, Thomas; Rauramaa, Rainer; Reinmaa, Eva; Ridker, Paul M; Rivadeneira, Fernando; Rotter, Jerome I; Saaristo, Timo E; Saleheen, Danish; Schlessinger, David; Slagboom, P Eline; Snieder, Harold; Spector, Tim D; Strauch, Konstantin; Stumvoll, Michael; Tuomilehto, Jaakko; Uusitupa, Matti; van der Harst, Pim; Völzke, Henry; Walker, Mark; Wareham, Nicholas J; Watkins, Hugh; Wichmann, H-Erich; Wilson, James F; Zanen, Pieter; Deloukas, Panos; Heid, Iris M; Lindgren, Cecilia M; Mohlke, Karen L; Speliotes, Elizabeth K; Thorsteinsdottir, Unnur; Barroso, Inês; Fox, Caroline S; North, Kari E; Strachan, David P; Beckmann, Jacques S; Berndt, Sonja I; Boehnke, Michael; Borecki, Ingrid B; McCarthy, Mark I; Metspalu, Andres; Stefansson, Kari; Uitterlinden, André G; van Duijn, Cornelia M; Franke, Lude; Willer, Cristen J; Price, Alkes L; Lettre, Guillaume; Loos, Ruth J F; Weedon, Michael N; Ingelsson, Erik; O'Connell, Jeffrey R; Abecasis, Goncalo R; Chasman, Daniel I; Goddard, Michael E; Visscher, Peter M; Hirschhorn, Joel N; Frayling, Timothy M

    2014-11-01

    Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ∼2,000, ∼3,700 and ∼9,500 SNPs explained ∼21%, ∼24% and ∼29% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/β-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants.

  20. Defining the role of common variation in the genomic and biological architecture of adult human height

    Science.gov (United States)

    Chu, Audrey Y; Estrada, Karol; Luan, Jian’an; Kutalik, Zoltán; Amin, Najaf; Buchkovich, Martin L; Croteau-Chonka, Damien C; Day, Felix R; Duan, Yanan; Fall, Tove; Fehrmann, Rudolf; Ferreira, Teresa; Jackson, Anne U; Karjalainen, Juha; Lo, Ken Sin; Locke, Adam E; Mägi, Reedik; Mihailov, Evelin; Porcu, Eleonora; Randall, Joshua C; Scherag, André; Vinkhuyzen, Anna AE; Westra, Harm-Jan; Winkler, Thomas W; Workalemahu, Tsegaselassie; Zhao, Jing Hua; Absher, Devin; Albrecht, Eva; Anderson, Denise; Baron, Jeffrey; Beekman, Marian; Demirkan, Ayse; Ehret, Georg B; Feenstra, Bjarke; Feitosa, Mary F; Fischer, Krista; Fraser, Ross M; Goel, Anuj; Gong, Jian; Justice, Anne E; Kanoni, Stavroula; Kleber, Marcus E; Kristiansson, Kati; Lim, Unhee; Lotay, Vaneet; Lui, Julian C; Mangino, Massimo; Leach, Irene Mateo; Medina-Gomez, Carolina; Nalls, Michael A; Nyholt, Dale R; Palmer, Cameron D; Pasko, Dorota; Pechlivanis, Sonali; Prokopenko, Inga; Ried, Janina S; Ripke, Stephan; Shungin, Dmitry; Stancáková, Alena; Strawbridge, Rona J; Sung, Yun Ju; Tanaka, Toshiko; Teumer, Alexander; Trompet, Stella; van der Laan, Sander W; van Setten, Jessica; Van Vliet-Ostaptchouk, Jana V; Wang, Zhaoming; Yengo, Loïc; Zhang, Weihua; Afzal, Uzma; Ärnlöv, Johan; Arscott, Gillian M; Bandinelli, Stefania; Barrett, Amy; Bellis, Claire; Bennett, Amanda J; Berne, Christian; Blüher, Matthias; Bolton, Jennifer L; Böttcher, Yvonne; Boyd, Heather A; Bruinenberg, Marcel; Buckley, Brendan M; Buyske, Steven; Caspersen, Ida H; Chines, Peter S; Clarke, Robert; Claudi-Boehm, Simone; Cooper, Matthew; Daw, E Warwick; De Jong, Pim A; Deelen, Joris; Delgado, Graciela; Denny, Josh C; Dhonukshe-Rutten, Rosalie; Dimitriou, Maria; Doney, Alex SF; Dörr, Marcus; Eklund, Niina; Eury, Elodie; Folkersen, Lasse; Garcia, Melissa E; Geller, Frank; Giedraitis, Vilmantas; Go, Alan S; Grallert, Harald; Grammer, Tanja B; Gräßler, Jürgen; Grönberg, Henrik; de Groot, Lisette C.P.G.M.; Groves, Christopher J; Haessler, Jeffrey; Hall, Per; Haller, Toomas; Hallmans, Goran; Hannemann, Anke; Hartman, Catharina A; Hassinen, Maija; Hayward, Caroline; Heard-Costa, Nancy L; Helmer, Quinta; Hemani, Gibran; Henders, Anjali K; Hillege, Hans L; Hlatky, Mark A; Hoffmann, Wolfgang; Hoffmann, Per; Holmen, Oddgeir; Houwing-Duistermaat, Jeanine J; Illig, Thomas; Isaacs, Aaron; James, Alan L; Jeff, Janina; Johansen, Berit; Johansson, Åsa; Jolley, Jennifer; Juliusdottir, Thorhildur; Junttila, Juhani; Kho, Abel N; Kinnunen, Leena; Klopp, Norman; Kocher, Thomas; Kratzer, Wolfgang; Lichtner, Peter; Lind, Lars; Lindström, Jaana; Lobbens, Stéphane; Lorentzon, Mattias; Lu, Yingchang; Lyssenko, Valeriya; Magnusson, Patrik KE; Mahajan, Anubha; Maillard, Marc; McArdle, Wendy L; McKenzie, Colin A; McLachlan, Stela; McLaren, Paul J; Menni, Cristina; Merger, Sigrun; Milani, Lili; Moayyeri, Alireza; Monda, Keri L; Morken, Mario A; Müller, Gabriele; Müller-Nurasyid, Martina; Musk, Arthur W; Narisu, Narisu; Nauck, Matthias; Nolte, Ilja M; Nöthen, Markus M; Oozageer, Laticia; Pilz, Stefan; Rayner, Nigel W; Renstrom, Frida; Robertson, Neil R; Rose, Lynda M; Roussel, Ronan; Sanna, Serena; Scharnagl, Hubert; Scholtens, Salome; Schumacher, Fredrick R; Schunkert, Heribert; Scott, Robert A; Sehmi, Joban; Seufferlein, Thomas; Shi, Jianxin; Silventoinen, Karri; Smit, Johannes H; Smith, Albert Vernon; Smolonska, Joanna; Stanton, Alice V; Stirrups, Kathleen; Stott, David J; Stringham, Heather M; Sundström, Johan; Swertz, Morris A; Syvänen, Ann-Christine; Tayo, Bamidele O; Thorleifsson, Gudmar; Tyrer, Jonathan P; van Dijk, Suzanne; van Schoor, Natasja M; van der Velde, Nathalie; van Heemst, Diana; van Oort, Floor VA; Vermeulen, Sita H; Verweij, Niek; Vonk, Judith M; Waite, Lindsay L; Waldenberger, Melanie; Wennauer, Roman; Wilkens, Lynne R; Willenborg, Christina; Wilsgaard, Tom; Wojczynski, Mary K; Wong, Andrew; Wright, Alan F; Zhang, Qunyuan; Arveiler, Dominique; Bakker, Stephan JL; Beilby, John; Bergman, Richard N; Bergmann, Sven; Biffar, Reiner; Blangero, John; Boomsma, Dorret I; Bornstein, Stefan R; Bovet, Pascal; Brambilla, Paolo; Brown, Morris J; Campbell, Harry; Caulfield, Mark J; Chakravarti, Aravinda; Collins, Rory; Collins, Francis S; Crawford, Dana C; Cupples, L Adrienne; Danesh, John; de Faire, Ulf; den Ruijter, Hester M; Erbel, Raimund; Erdmann, Jeanette; Eriksson, Johan G; Farrall, Martin; Ferrannini, Ele; Ferrières, Jean; Ford, Ian; Forouhi, Nita G; Forrester, Terrence; Gansevoort, Ron T; Gejman, Pablo V; Gieger, Christian; Golay, Alain; Gottesman, Omri; Gudnason, Vilmundur; Gyllensten, Ulf; Haas, David W; Hall, Alistair S; Harris, Tamara B; Hattersley, Andrew T; Heath, Andrew C; Hengstenberg, Christian; Hicks, Andrew A; Hindorff, Lucia A; Hingorani, Aroon D; Hofman, Albert; Hovingh, G Kees; Humphries, Steve E; Hunt, Steven C; Hypponen, Elina; Jacobs, Kevin B; Jarvelin, Marjo-Riitta; Jousilahti, Pekka; Jula, Antti M; Kaprio, Jaakko; Kastelein, John JP; Kayser, Manfred; Kee, Frank; Keinanen-Kiukaanniemi, Sirkka M; Kiemeney, Lambertus A; Kooner, Jaspal S; Kooperberg, Charles; Koskinen, Seppo; Kovacs, Peter; Kraja, Aldi T; Kumari, Meena; Kuusisto, Johanna; Lakka, Timo A; Langenberg, Claudia; Le Marchand, Loic; Lehtimäki, Terho; Lupoli, Sara; Madden, Pamela AF; Männistö, Satu; Manunta, Paolo; Marette, André; Matise, Tara C; McKnight, Barbara; Meitinger, Thomas; Moll, Frans L; Montgomery, Grant W; Morris, Andrew D; Morris, Andrew P; Murray, Jeffrey C; Nelis, Mari; Ohlsson, Claes; Oldehinkel, Albertine J; Ong, Ken K; Ouwehand, Willem H; Pasterkamp, Gerard; Peters, Annette; Pramstaller, Peter P; Price, Jackie F; Qi, Lu; Raitakari, Olli T; Rankinen, Tuomo; Rao, DC; Rice, Treva K; Ritchie, Marylyn; Rudan, Igor; Salomaa, Veikko; Samani, Nilesh J; Saramies, Jouko; Sarzynski, Mark A; Schwarz, Peter EH; Sebert, Sylvain; Sever, Peter; Shuldiner, Alan R; Sinisalo, Juha; Steinthorsdottir, Valgerdur; Stolk, Ronald P; Tardif, Jean-Claude; Tönjes, Anke; Tremblay, Angelo; Tremoli, Elena; Virtamo, Jarmo; Vohl, Marie-Claude; Amouyel, Philippe; Asselbergs, Folkert W; Assimes, Themistocles L; Bochud, Murielle; Boehm, Bernhard O; Boerwinkle, Eric; Bottinger, Erwin P; Bouchard, Claude; Cauchi, Stéphane; Chambers, John C; Chanock, Stephen J; Cooper, Richard S; de Bakker, Paul IW; Dedoussis, George; Ferrucci, Luigi; Franks, Paul W; Froguel, Philippe; Groop, Leif C; Haiman, Christopher A; Hamsten, Anders; Hayes, M Geoffrey; Hui, Jennie; Hunter, David J.; Hveem, Kristian; Jukema, J Wouter; Kaplan, Robert C; Kivimaki, Mika; Kuh, Diana; Laakso, Markku; Liu, Yongmei; Martin, Nicholas G; März, Winfried; Melbye, Mads; Moebus, Susanne; Munroe, Patricia B; Njølstad, Inger; Oostra, Ben A; Palmer, Colin NA; Pedersen, Nancy L; Perola, Markus; Pérusse, Louis; Peters, Ulrike; Powell, Joseph E; Power, Chris; Quertermous, Thomas; Rauramaa, Rainer; Reinmaa, Eva; Ridker, Paul M; Rivadeneira, Fernando; Rotter, Jerome I; Saaristo, Timo E; Saleheen, Danish; Schlessinger, David; Slagboom, P Eline; Snieder, Harold; Spector, Tim D; Strauch, Konstantin; Stumvoll, Michael; Tuomilehto, Jaakko; Uusitupa, Matti; van der Harst, Pim; Völzke, Henry; Walker, Mark; Wareham, Nicholas J; Watkins, Hugh; Wichmann, H-Erich; Wilson, James F; Zanen, Pieter; Deloukas, Panos; Heid, Iris M; Lindgren, Cecilia M; Mohlke, Karen L; Speliotes, Elizabeth K; Thorsteinsdottir, Unnur; Barroso, Inês; Fox, Caroline S; North, Kari E; Strachan, David P; Beckmann, Jacques S.; Berndt, Sonja I; Boehnke, Michael; Borecki, Ingrid B; McCarthy, Mark I; Metspalu, Andres; Stefansson, Kari; Uitterlinden, André G; van Duijn, Cornelia M; Franke, Lude; Willer, Cristen J; Price, Alkes L.; Lettre, Guillaume; Loos, Ruth JF; Weedon, Michael N; Ingelsson, Erik; O’Connell, Jeffrey R; Abecasis, Goncalo R; Chasman, Daniel I; Goddard, Michael E

    2014-01-01

    Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explain one-fifth of heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ~2,000, ~3,700 and ~9,500 SNPs explained ~21%, ~24% and ~29% of phenotypic variance. Furthermore, all common variants together captured the majority (60%) of heritability. The 697 variants clustered in 423 loci enriched for genes, pathways, and tissue-types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/beta-catenin, and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants. PMID:25282103

  1. Defining the role of common variation in the genomic and biological architecture of adult human height

    DEFF Research Database (Denmark)

    Wood, Andrew R.; Esko, Tonu; Yang, Jian

    2014-01-01

    to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/beta-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR...

  2. Defining the role of common variation in the genomic and biological architecture of adult human height

    NARCIS (Netherlands)

    Wood, Andrew R.; Esko, Tonu; Yang, Jian; Vedantam, Sailaja; Pers, Tune H.; Gustafsson, Stefan; Chu, Audrey Y.; Estrada, Karol; Luan, Jian'an; Kutalik, Zoltán; Amin, Najaf; Buchkovich, Martin L.; Croteau-Chonka, Damien C.; Day, Felix R.; Duan, Yanan; Fall, Tove; Fehrmann, Rudolf; Ferreira, Teresa; Jackson, Anne U.; Karjalainen, Juha; Lo, Ken Sin; Locke, Adam E.; Mägi, Reedik; Mihailov, Evelin; Porcu, Eleonora; Randall, Joshua C.; Scherag, André; Vinkhuyzen, Anna A. E.; Westra, Harm-Jan; Winkler, Thomas W.; Workalemahu, Tsegaselassie; Zhao, Jing Hua; Absher, Devin; Albrecht, Eva; Anderson, Denise; Baron, Jeffrey; Beekman, Marian; Demirkan, Ayse; Ehret, Georg B.; Feenstra, Bjarke; Feitosa, Mary F.; Fischer, Krista; Fraser, Ross M.; Goel, Anuj; Gong, Jian; Justice, Anne E.; Kanoni, Stavroula; Kleber, Marcus E.; Kristiansson, Kati; Lim, Unhee; Lotay, Vaneet; Lui, Julian C.; Mangino, Massimo; Mateo Leach, Irene; Medina-Gomez, Carolina; Nalls, Michael A.; Nyholt, Dale R.; Palmer, Cameron D.; Pasko, Dorota; Pechlivanis, Sonali; Prokopenko, Inga; Ried, Janina S.; Ripke, Stephan; Shungin, Dmitry; Stancáková, Alena; Strawbridge, Rona J.; Sung, Yun Ju; Tanaka, Toshiko; Teumer, Alexander; Trompet, Stella; van der Laan, Sander W.; van Setten, Jessica; van Vliet-Ostaptchouk, Jana V.; Wang, Zhaoming; Yengo, Loïc; Zhang, Weihua; Afzal, Uzma; Arnlöv, Johan; Arscott, Gillian M.; Bandinelli, Stefania; Barrett, Amy; Bellis, Claire; Bennett, Amanda J.; Berne, Christian; Blüher, Matthias; Bolton, Jennifer L.; Böttcher, Yvonne; Boyd, Heather A.; Bruinenberg, Marcel; Buckley, Brendan M.; Buyske, Steven; Caspersen, Ida H.; Chines, Peter S.; Clarke, Robert; Claudi-Boehm, Simone; Cooper, Matthew; Daw, E. Warwick; de Jong, Pim A.; Deelen, Joris; Delgado, Graciela; Denny, Josh C.; Dhonukshe-Rutten, Rosalie; Dimitriou, Maria; Doney, Alex S. F.; Dörr, Marcus; Eklund, Niina; Eury, Elodie; Folkersen, Lasse; Garcia, Melissa E.; Geller, Frank; Giedraitis, Vilmantas; Go, Alan S.; Grallert, Harald; Grammer, Tanja B.; Gräßler, Jürgen; Grönberg, Henrik; de Groot, Lisette C. P. G. M.; Groves, Christopher J.; Haessler, Jeffrey; Hall, Per; Haller, Toomas; Hallmans, Goran; Hannemann, Anke; Hartman, Catharina A.; Hassinen, Maija; Hayward, Caroline; Heard-Costa, Nancy L.; Helmer, Quinta; Hemani, Gibran; Henders, Anjali K.; Hillege, Hans L.; Hlatky, Mark A.; Hoffmann, Wolfgang; Hoffmann, Per; Holmen, Oddgeir; Houwing-Duistermaat, Jeanine J.; Illig, Thomas; Isaacs, Aaron; James, Alan L.; Jeff, Janina; Johansen, Berit; Johansson, Åsa; Jolley, Jennifer; Juliusdottir, Thorhildur; Junttila, Juhani; Kho, Abel N.; Kinnunen, Leena; Klopp, Norman; Kocher, Thomas; Kratzer, Wolfgang; Lichtner, Peter; Lind, Lars; Lindström, Jaana; Lobbens, Stéphane; Lorentzon, Mattias; Lu, Yingchang; Lyssenko, Valeriya; Magnusson, Patrik K. E.; Mahajan, Anubha; Maillard, Marc; McArdle, Wendy L.; McKenzie, Colin A.; McLachlan, Stela; McLaren, Paul J.; Menni, Cristina; Merger, Sigrun; Milani, Lili; Moayyeri, Alireza; Monda, Keri L.; Morken, Mario A.; Müller, Gabriele; Müller-Nurasyid, Martina; Musk, Arthur W.; Narisu, Narisu; Nauck, Matthias; Nolte, Ilja M.; Nöthen, Markus M.; Oozageer, Laticia; Pilz, Stefan; Rayner, Nigel W.; Renstrom, Frida; Robertson, Neil R.; Rose, Lynda M.; Roussel, Ronan; Sanna, Serena; Scharnagl, Hubert; Scholtens, Salome; Schumacher, Fredrick R.; Schunkert, Heribert; Scott, Robert A.; Sehmi, Joban; Seufferlein, Thomas; Shi, Jianxin; Silventoinen, Karri; Smit, Johannes H.; Smith, Albert Vernon; Smolonska, Joanna; Stanton, Alice V.; Stirrups, Kathleen; Stott, David J.; Stringham, Heather M.; Sundström, Johan; Swertz, Morris A.; Syvänen, Ann-Christine; Tayo, Bamidele O.; Thorleifsson, Gudmar; Tyrer, Jonathan P.; van Dijk, Suzanne; van Schoor, Natasja M.; van der Velde, Nathalie; van Heemst, Diana; van Oort, Floor V. A.; Vermeulen, Sita H.; Verweij, Niek; Vonk, Judith M.; Waite, Lindsay L.; Waldenberger, Melanie; Wennauer, Roman; Wilkens, Lynne R.; Willenborg, Christina; Wilsgaard, Tom; Wojczynski, Mary K.; Wong, Andrew; Wright, Alan F.; Zhang, Qunyuan; Arveiler, Dominique; Bakker, Stephan J. L.; Beilby, John; Bergman, Richard N.; Bergmann, Sven; Biffar, Reiner; Blangero, John; Boomsma, Dorret I.; Bornstein, Stefan R.; Bovet, Pascal; Brambilla, Paolo; Brown, Morris J.; Campbell, Harry; Caulfield, Mark J.; Chakravarti, Aravinda; Collins, Rory; Collins, Francis S.; Crawford, Dana C.; Cupples, L. Adrienne; Danesh, John; de Faire, Ulf; den Ruijter, Hester M.; Erbel, Raimund; Erdmann, Jeanette; Eriksson, Johan G.; Farrall, Martin; Ferrannini, Ele; Ferrières, Jean; Ford, Ian; Forouhi, Nita G.; Forrester, Terrence; Gansevoort, Ron T.; Gejman, Pablo V.; Gieger, Christian; Golay, Alain; Gottesman, Omri; Gudnason, Vilmundur; Gyllensten, Ulf; Haas, David W.; Hall, Alistair S.; Harris, Tamara B.; Hattersley, Andrew T.; Heath, Andrew C.; Hengstenberg, Christian; Hicks, Andrew A.; Hindorff, Lucia A.; Hingorani, Aroon D.; Hofman, Albert; Hovingh, G. Kees; Humphries, Steve E.; Hunt, Steven C.; Hypponen, Elina; Jacobs, Kevin B.; Jarvelin, Marjo-Riitta; Jousilahti, Pekka; Jula, Antti M.; Kaprio, Jaakko; Kastelein, John J. P.; Kayser, Manfred; Kee, Frank; Keinanen-Kiukaanniemi, Sirkka M.; Kiemeney, Lambertus A.; Kooner, Jaspal S.; Kooperberg, Charles; Koskinen, Seppo; Kovacs, Peter; Kraja, Aldi T.; Kumari, Meena; Kuusisto, Johanna; Lakka, Timo A.; Langenberg, Claudia; Le Marchand, Loic; Lehtimäki, Terho; Lupoli, Sara; Madden, Pamela A. F.; Männistö, Satu; Manunta, Paolo; Marette, André; Matise, Tara C.; McKnight, Barbara; Meitinger, Thomas; Moll, Frans L.; Montgomery, Grant W.; Morris, Andrew D.; Morris, Andrew P.; Murray, Jeffrey C.; Nelis, Mari; Ohlsson, Claes; Oldehinkel, Albertine J.; Ong, Ken K.; Ouwehand, Willem H.; Pasterkamp, Gerard; Peters, Annette; Pramstaller, Peter P.; Price, Jackie F.; Qi, Lu; Raitakari, Olli T.; Rankinen, Tuomo; Rao, D. C.; Rice, Treva K.; Ritchie, Marylyn; Rudan, Igor; Salomaa, Veikko; Samani, Nilesh J.; Saramies, Jouko; Sarzynski, Mark A.; Schwarz, Peter E. H.; Sebert, Sylvain; Sever, Peter; Shuldiner, Alan R.; Sinisalo, Juha; Steinthorsdottir, Valgerdur; Stolk, Ronald P.; Tardif, Jean-Claude; Tönjes, Anke; Tremblay, Angelo; Tremoli, Elena; Virtamo, Jarmo; Vohl, Marie-Claude; Amouyel, Philippe; Asselbergs, Folkert W.; Assimes, Themistocles L.; Bochud, Murielle; Boehm, Bernhard O.; Boerwinkle, Eric; Bottinger, Erwin P.; Bouchard, Claude; Cauchi, Stéphane; Chambers, John C.; Chanock, Stephen J.; Cooper, Richard S.; de Bakker, Paul I. W.; Dedoussis, George; Ferrucci, Luigi; Franks, Paul W.; Froguel, Philippe; Groop, Leif C.; Haiman, Christopher A.; Hamsten, Anders; Hayes, M. Geoffrey; Hui, Jennie; Hunter, David J.; Hveem, Kristian; Jukema, J. Wouter; Kaplan, Robert C.; Kivimaki, Mika; Kuh, Diana; Laakso, Markku; Liu, Yongmei; Martin, Nicholas G.; März, Winfried; Melbye, Mads; Moebus, Susanne; Munroe, Patricia B.; Njølstad, Inger; Oostra, Ben A.; Palmer, Colin N. A.; Pedersen, Nancy L.; Perola, Markus; Pérusse, Louis; Peters, Ulrike; Powell, Joseph E.; Power, Chris; Quertermous, Thomas; Rauramaa, Rainer; Reinmaa, Eva; Ridker, Paul M.; Rivadeneira, Fernando; Rotter, Jerome I.; Saaristo, Timo E.; Saleheen, Danish; Schlessinger, David; Slagboom, P. Eline; Snieder, Harold; Spector, Tim D.; Strauch, Konstantin; Stumvoll, Michael; Tuomilehto, Jaakko; Uusitupa, Matti; van der Harst, Pim; Völzke, Henry; Walker, Mark; Wareham, Nicholas J.; Watkins, Hugh; Wichmann, H.-Erich; Wilson, James F.; Zanen, Pieter; Deloukas, Panos; Heid, Iris M.; Lindgren, Cecilia M.; Mohlke, Karen L.; Speliotes, Elizabeth K.; Thorsteinsdottir, Unnur; Barroso, Inês; Fox, Caroline S.; North, Kari E.; Strachan, David P.; Beckmann, Jacques S.; Berndt, Sonja I.; Boehnke, Michael; Borecki, Ingrid B.; McCarthy, Mark I.; Metspalu, Andres; Stefansson, Kari; Uitterlinden, André G.; van Duijn, Cornelia M.; Franke, Lude; Willer, Cristen J.; Price, Alkes L.; Lettre, Guillaume; Loos, Ruth J. F.; Weedon, Michael N.; Ingelsson, Erik; O'Connell, Jeffrey R.; Abecasis, Goncalo R.; Chasman, Daniel I.; Goddard, Michael E.; Visscher, Peter M.; Hirschhorn, Joel N.; Frayling, Timothy M.; McCarty, Catherine A.; Starren, Justin; Peissig, Peggy; Berg, Richard; Rasmussen, Luke; Linneman, James; Miller, Aaron; Choudary, Vidhu; Chen, Lin; Waudby, Carol; Kitchner, Terrie; Reeser, Jonathan; Fost, Norman; Wilke, Russell A.; Chisholm, Rex L.; Avila, Pedro C.; Greenland, Philip; Hayes, M. Geoff; Kho, Abel; Kibbe, Warren A.; Lemke, Amy A.; Lowe, William L.; Smith, Maureen E.; Wolf, Wendy A.; Pacheco, Jennifer A.; Thompson, William K.; Humowiecki, Joel; Law, May; Chute, Christopher; Kullo, Iftikar; Koenig, Barbara; de Andrade, Mariza; Bielinski, Suzette; Pathak, Jyotishman; Savova, Guergana; Wu, Joel; Henriksen, Joan; Ding, Keyue; Hart, Lacey; Palbicki, Jeremy; Larson, Eric B.; Newton, Katherine; Ludman, Evette; Spangler, Leslie; Hart, Gene; Carrell, David; Jarvik, Gail; Crane, Paul; Burke, Wylie; Fullerton, Stephanie Malia; Trinidad, Susan Brown; Carlson, Chris; Hutchinson, Fred; McDavid, Andrew; Roden, Dan M.; Clayton, Ellen; Haines, Jonathan L.; Masys, Daniel R.; Churchill, Larry R.; Cornfield, Daniel; Crawford, Dana; Darbar, Dawood; Denny, Joshua C.; Malin, Bradley A.; Ritchie, Marylyn D.; Schildcrout, Jonathan S.; Xu, Hua; Ramirez, Andrea Havens; Basford, Melissa; Pulley, Jill; Alizadeh, Behrooz Z.; de Boer, Rudolf A.; Boezen, H. Marike; van der Klauw, Melanie M.; Navis, Gerjan; Ormel, Johan; Postma, Dirkje S.; Rosmalen, Judith G. M.; Slaets, Joris P.; Wolffenbuttel, Bruce H. R.; Wijmenga, Cisca; Kathiresan, Sekar; Voight, Benjamin F.; Purcell, Shaun; Musunuru, Kiran; Ardissino, Diego; Mannucci, Pier M.; Anand, Sonia; Engert, James C.; Reilly, Muredach P.; Rader, Daniel J.; Morgan, Thomas; Spertus, John A.; Stoll, Monika; Girelli, Domenico; McKeown, Pascal P.; Patterson, Chris C.; Siscovick, David S.; O'Donnell, Christopher J.; Elosua, Roberto; Peltonen, Leena; Schwartz, Stephen M.; Melander, Olle; Altshuler, David; Merlini, Pier Angelica; Berzuini, Carlo; Bernardinelli, Luisa; Peyvandi, Flora; Tubaro, Marco; Celli, Patrizia; Ferrario, Maurizio; Fetiveau, Raffaela; Marziliano, Nicola; Casari, Giorgio; Galli, Michele; Ribichini, Flavio; Rossi, Marco; Bernardi, Francesco; Zonzin, Pietro; Piazza, Alberto; Yee, Jean; Friedlander, Yechiel; Marrugat, Jaume; Lucas, Gavin; Subirana, Isaac; Sala, Joan; Ramos, Rafael; Meigs, James B.; Williams, Gordon; Nathan, David M.; MacRae, Calum A.; Havulinna, Aki S.; Berglund, Goran; Asselta, Rosanna; Duga, Stefano; Spreafico, Marta; Daly, Mark J.; Nemesh, James; Korn, Joshua M.; McCarroll, Steven A.; Surti, Aarti; Guiducci, Candace; Gianniny, Lauren; Mirel, Daniel; Parkin, Melissa; Burtt, Noel; Gabriel, Stacey B.; Thompson, John R.; Braund, Peter S.; Wright, Benjamin J.; Balmforth, Anthony J.; Ball, Stephen G.; Schunkert, I. Heribert; Linsel-Nitschke, Patrick; Lieb, Wolfgang; Ziegler, Andreas; König, Inke R.; Fischer, Marcus; Stark, Klaus; Grosshennig, Anika; Preuss, Michael; Schreiber, Stefan; Ouwehand, Willem; Scholz, Michael; Cambien, Francois; Goodall, Alison; Li, Mingyao; Chen, Zhen; Wilensky, Robert; Matthai, William; Qasim, Atif; Hakonarson, Hakon H.; Devaney, Joe; Burnett, Mary-Susan; Pichard, Augusto D.; Kent, Kenneth M.; Satler, Lowell; Lindsay, Joseph M.; Waksman, Ron; Knouff, Christopher W.; Waterworth, Dawn M.; Walker, Max C.; Mooser, Vincent; Epstein, Stephen E.; Scheffold, Thomas; Berger, Klaus; Huge, Andreas; Martinelli, Nicola; Olivieri, Oliviero; Corrocher, Roberto; Hólm, Hilma; Do, Ron; Xie, Changchun; Siscovick, David; Matise, Tara; Buyske, Steve; Higashio, Julia; Williams, Rasheeda; Nato, Andrew; Ambite, Jose Luis; Deelman, Ewa; Manolio, Teri; Hindorff, Lucia; Heiss, Gerardo; Taylor, Kira; Franceschini, Nora; Avery, Christy; Graff, Misa; Lin, Danyu; Quibrera, Miguel; Cochran, Barbara; Kao, Linda; Umans, Jason; Cole, Shelley; MacCluer, Jean; Person, Sharina; Pankow, James; Gross, Myron; Fornage, Myriam; Durda, Peter; Jenny, Nancy; Patsy, Bruce; Arnold, Alice; Buzkova, Petra; Haines, Jonathan; Murdock, Deborah; Glenn, Kim; Brown-Gentry, Kristin; Thornton-Wells, Tricia; Dumitrescu, Logan; Bush, William S.; Mitchell, Sabrina L.; Goodloe, Robert; Wilson, Sarah; Boston, Jonathan; Malinowski, Jennifer; Restrepo, Nicole; Oetjens, Matthew; Fowke, Jay; Zheng, Wei; Spencer, Kylee; Pendergrass, Sarah; Le Marchand, Loïc; Wilkens, Lynne; Park, Lani; Tiirikainen, Maarit; Kolonel, Laurence; Cheng, Iona; Wang, Hansong; Shohet, Ralph; Haiman, Christopher; Stram, Daniel; Henderson, Brian; Monroe, Kristine; Schumacher, Fredrick; Anderson, Garnet; Prentice, Ross; LaCroix, Andrea; Wu, Chunyuan; Carty, Cara; Rosse, Stephanie; Young, Alicia; Haessler, Jeff; Kocarnik, Jonathan; Lin, Yi; Jackson, Rebecca; Duggan, David; Kuller, Lew

    2014-01-01

    Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ∼2,000, ∼3,700

  3. Phenotypic variation in nurse traits and community feedbacks define an alpine community.

    Science.gov (United States)

    Michalet, Richard; Xiao, Sa; Touzard, Blaise; Smith, David S; Cavieres, Lohengrin A; Callaway, Ragan M; Whitham, Thomas G

    2011-05-01

    Much is known about facilitation, but virtually nothing about the underlying genetic and evolutionary consequences of this important interaction. We assessed the potential of phenotypic differences in facilitative effects of a foundation species to determine the composition of an Alpine community in Arizona. Two phenotypes of Geum rossii occur along a gradient of disturbance, with 'tight' competitive cushions in stable conditions and 'loose' facilitative cushions in disturbed conditions. A common-garden study suggested that field-based traits may have a genetic basis. Field experiments showed that the reproductive fitness of G. rossii cushions decreased with increasing facilitation. Finally, using a dual-lattice model we showed that including the cost and benefit of facilitation may contribute to the co-occurrence of genotypes with contrasting facilitative effects. Our results indicate that changes in community composition due to phenotypic differences in facilitative effects of a foundation species may in turn affect selective pressures on the foundation species. © 2011 Blackwell Publishing Ltd/CNRS.

  4. Thyroid Problems

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Thyroid Problems Font size A A A Print Share Glossary Basic ... enough thyroid hormone, usually of the thyroxine (T4) type of hormone. Your T4 levels can drop temporarily ...

  5. Balance Problems

    Science.gov (United States)

    ... fully trust your sense of balance. Loss of balance also raises the risk of falls. This is a serious and even life-threatening ... 65. Balance disorders are serious because of the risk of falls. But occasionally balance problems may warn of another health condition, such ...

  6. Application-Defined Decentralized Access Control

    Science.gov (United States)

    Xu, Yuanzhong; Dunn, Alan M.; Hofmann, Owen S.; Lee, Michael Z.; Mehdi, Syed Akbar; Witchel, Emmett

    2014-01-01

    DCAC is a practical OS-level access control system that supports application-defined principals. It allows normal users to perform administrative operations within their privilege, enabling isolation and privilege separation for applications. It does not require centralized policy specification or management, giving applications freedom to manage their principals while the policies are still enforced by the OS. DCAC uses hierarchically-named attributes as a generic framework for user-defined policies such as groups defined by normal users. For both local and networked file systems, its execution time overhead is between 0%–9% on file system microbenchmarks, and under 1% on applications. This paper shows the design and implementation of DCAC, as well as several real-world use cases, including sandboxing applications, enforcing server applications’ security policies, supporting NFS, and authenticating user-defined sub-principals in SSH, all with minimal code changes. PMID:25426493

  7. Software Defined Multiband EVA Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this research is to propose a reliable, lightweight, programmable, multi-band, multi-mode, miniaturized frequency-agile EVA software defined radio...

  8. Reconfigurable, Cognitive Software Defined Radio, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — IAI is actively developing Software Defined Radio platforms that can adaptively switch between different modes of operation by modifying both transmit waveforms and...

  9. Software Defined Multiband EVA Radio, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of Phase 2 is to build a reliable, lightweight, programmable, multi-mode, miniaturized EVA Software Defined Radio (SDR) that supports data telemetry,...

  10. Reconfigurable, Cognitive Software Defined Radio, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Automation Inc, (IAI) is currently developing a software defined radio (SDR) platform that can adaptively switch between different modes of operation for...

  11. Optimum Criteria for Developing Defined Structures

    Directory of Open Access Journals (Sweden)

    Ion IVAN

    2008-01-01

    Full Text Available Basic aspects concerning distributed applications are presented: definition, particularities and importance. For distributed applications linear, arborescent, graph structures are defined with different versions and aggregation methods. Distributed applications have associated structures which through their characteristics influence the costs of the stages in the development cycle and the exploitation costs transferred to each user. The complexity of the defined structures is analyzed. The minimum and maximum criteria are enumerated for optimizing distributed application structures.

  12. Considerations on field problem structure

    International Nuclear Information System (INIS)

    Pavelescu, M.

    1977-01-01

    A survey of the three field problem types known today: equilibrium, eigen value and propagation problems is presented. The place occupied by neutron field in the nuclear reactor systems both statics and dynamics is shown. The special class of approximate solution method concerning the solving of field and boundary equations is analysed. The residual and variational method and the finite element method which presents a special interest are examined as well. (author)

  13. Two-dimensional strain gradient damage modeling: a variational approach

    Science.gov (United States)

    Placidi, Luca; Misra, Anil; Barchiesi, Emilio

    2018-06-01

    In this paper, we formulate a linear elastic second gradient isotropic two-dimensional continuum model accounting for irreversible damage. The failure is defined as the condition in which the damage parameter reaches 1, at least in one point of the domain. The quasi-static approximation is done, i.e., the kinetic energy is assumed to be negligible. In order to deal with dissipation, a damage dissipation term is considered in the deformation energy functional. The key goal of this paper is to apply a non-standard variational procedure to exploit the damage irreversibility argument. As a result, we derive not only the equilibrium equations but, notably, also the Karush-Kuhn-Tucker conditions. Finally, numerical simulations for exemplary problems are discussed as some constitutive parameters are varying, with the inclusion of a mesh-independence evidence. Element-free Galerkin method and moving least square shape functions have been employed.

  14. Deficient motion-defined and texture-defined figure-ground segregation in amblyopic children.

    Science.gov (United States)

    Wang, Jane; Ho, Cindy S; Giaschi, Deborah E

    2007-01-01

    Motion-defined form deficits in the fellow eye and the amblyopic eye of children with amblyopia implicate possible direction-selective motion processing or static figure-ground segregation deficits. Deficient motion-defined form perception in the fellow eye of amblyopic children may not be fully accounted for by a general motion processing deficit. This study investigates the contribution of figure-ground segregation deficits to the motion-defined form perception deficits in amblyopia. Performances of 6 amblyopic children (5 anisometropic, 1 anisostrabismic) and 32 control children with normal vision were assessed on motion-defined form, texture-defined form, and global motion tasks. Performance on motion-defined and texture-defined form tasks was significantly worse in amblyopic children than in control children. Performance on global motion tasks was not significantly different between the 2 groups. Faulty figure-ground segregation mechanisms are likely responsible for the observed motion-defined form perception deficits in amblyopia.

  15. Steady-state groundwater recharge in trapezoidal-shaped aquifers: A semi-analytical approach based on variational calculus

    Science.gov (United States)

    Mahdavi, Ali; Seyyedian, Hamid

    2014-05-01

    This study presents a semi-analytical solution for steady groundwater flow in trapezoidal-shaped aquifers in response to an areal diffusive recharge. The aquifer is homogeneous, anisotropic and interacts with four surrounding streams of constant-head. Flow field in this laterally bounded aquifer-system is efficiently constructed by means of variational calculus. This is accomplished by minimizing a properly defined penalty function for the associated boundary value problem. Simple yet demonstrative scenarios are defined to investigate anisotropy effects on the water table variation. Qualitative examination of the resulting equipotential contour maps and velocity vector field illustrates the validity of the method, especially in the vicinity of boundary lines. Extension to the case of triangular-shaped aquifer with or without an impervious boundary line is also demonstrated through a hypothetical example problem. The present solution benefits from an extremely simple mathematical expression and exhibits strictly close agreement with the numerical results obtained from Modflow. Overall, the solution may be used to conduct sensitivity analysis on various hydrogeological parameters that affect water table variation in aquifers defined in trapezoidal or triangular-shaped domains.

  16. Minimizing communication cost among distributed controllers in software defined networks

    Science.gov (United States)

    Arlimatti, Shivaleela; Elbreiki, Walid; Hassan, Suhaidi; Habbal, Adib; Elshaikh, Mohamed

    2016-08-01

    Software Defined Networking (SDN) is a new paradigm to increase the flexibility of today's network by promising for a programmable network. The fundamental idea behind this new architecture is to simplify network complexity by decoupling control plane and data plane of the network devices, and by making the control plane centralized. Recently controllers have distributed to solve the problem of single point of failure, and to increase scalability and flexibility during workload distribution. Even though, controllers are flexible and scalable to accommodate more number of network switches, yet the problem of intercommunication cost between distributed controllers is still challenging issue in the Software Defined Network environment. This paper, aims to fill the gap by proposing a new mechanism, which minimizes intercommunication cost with graph partitioning algorithm, an NP hard problem. The methodology proposed in this paper is, swapping of network elements between controller domains to minimize communication cost by calculating communication gain. The swapping of elements minimizes inter and intra communication cost among network domains. We validate our work with the OMNeT++ simulation environment tool. Simulation results show that the proposed mechanism minimizes the inter domain communication cost among controllers compared to traditional distributed controllers.

  17. Using templates and linguistic patterns to define process performance indicators

    Science.gov (United States)

    del-Río-Ortega, Adela; Resinas, Manuel; Durán, Amador; Ruiz-Cortés, Antonio

    2016-02-01

    Process performance management (PPM) aims at measuring, monitoring and analysing the performance of business processes (BPs), in order to check the achievement of strategic and operational goals and to support decision-making for their optimisation. PPM is based on process performance indicators (PPIs), so having an appropriate definition of them is crucial. One of the main problems of PPIs definition is to express them in an unambiguous, complete, understandable, traceable and verifiable manner. In practice, PPIs are defined informally - usually in ad hoc, natural language, with its well-known problems - or they are defined from an implementation perspective, hardly understandable to non-technical people. In order to solve this problem, in this article we propose a novel approach to improve the definition of PPIs using templates and linguistic patterns. This approach promotes reuse, reduces both ambiguities and missing information, is understandable to all stakeholders and maintains traceability with the process model. Furthermore, it enables the automated processing of PPI definitions by its straightforward translation into the PPINOT metamodel, allowing the gathering of the required information for their computation as well as the analysis of the relationships between them and with BP elements.

  18. Variational Integrals of a Class of Nonhomogeneous -Harmonic Equations

    Directory of Open Access Journals (Sweden)

    Guanfeng Li

    2014-01-01

    Full Text Available We introduce a class of variational integrals whose Euler equations are nonhomogeneous -harmonic equations. We investigate the relationship between the minimization problem and the Euler equation and give a simple proof of the existence of some nonhomogeneous -harmonic equations by applying direct methods of the calculus of variations. Besides, we establish some interesting results on variational integrals.

  19. Agricultural problems

    International Nuclear Information System (INIS)

    Bickerton, George E.

    1997-01-01

    Although there were not reasons to deplore against major activity release from any of the 110 industrial reactors authorized to operate in US, the nuclear incident that occurred at the Three Mile Island Plant in 1979 urged the public conscience toward the necessity of readiness to cope with events of this type. The personnel of the Emergency Planning Office functioning in the frame of US Department of Agriculture has already participated in around 600 intervention drillings on a federal, local or state scale to plan, test or asses radiological emergency plans or to intervene locally. These exercises allowed acquiring a significant experience in elaborating emergency plans, planning the drillings, working out scenarios and evaluation of the potential impact of accidents from the agricultural point of view. We have also taken part in different international drillings among which the most recent are INEX 1 and RADEX 94. We have found on these occasions that the agricultural problems are essential preoccupations in most of the cases no matter if the context is international, national, local or of state level. The paper poses problems specifically related to milk, fruits and vegetables, soils, meat and meat products. Finally the paper discusses issues like drilling planning, alarm and notification, sampling strategy, access authorizations for farmers, removing of contamination wastes. A number of social, political and economical relating problems are also mentioned

  20. On Gap Functions for Quasi-Variational Inequalities

    Directory of Open Access Journals (Sweden)

    Kouichi Taji

    2008-01-01

    Full Text Available For variational inequalities, various merit functions, such as the gap function, the regularized gap function, the D-gap function and so on, have been proposed. These functions lead to equivalent optimization formulations and are used to optimization-based methods for solving variational inequalities. In this paper, we extend the regularized gap function and the D-gap functions for a quasi-variational inequality, which is a generalization of the variational inequality and is used to formulate generalized equilibrium problems. These extensions are shown to formulate equivalent optimization problems for quasi-variational inequalities and are shown to be continuous and directionally differentiable.

  1. Eigenvalue Problems.

    Science.gov (United States)

    1987-06-01

    11.55), we get (11.56) 1 bu(u - ZhU)dx < bull - hUi{ !s Ch2V(a), where C = C(aOa 1lbo,blV 0 (a),X). Next we consider I(S-Sh)uIL and Ij(T-Th)uaL2 It is...Math. Ann. 97, 711-736. Courant, R. [1943]: Variational methods for the solution of prob- .-lems of equilibrium and vibrations, Bull . Amer. Math. Soc...fournir des bornes superieures ou inferieures, C.R. Acad. Sci., Paris 235, 995-997. .V Prodi, G. (1962]: Theoremi di tipo locale per il sistema de Navier

  2. The process model of problem solving difficulty

    NARCIS (Netherlands)

    Pala, O.; Rouwette, E.A.J.A.; Vennix, J.A.M.

    2002-01-01

    Groups and organizations, or in general multi-actor decision-making groups, frequently come across complex problems in which neither the problem definition nor the interrelations of parts that make up the problem are well defined. In these kinds of situations, members of a decision-making group

  3. Bilateral renal artery variation

    OpenAIRE

    Üçerler, Hülya; Üzüm, Yusuf; İkiz, Z. Aslı Aktan

    2014-01-01

    Each kidney is supplied by a single renal artery, although renal artery variations are common. Variations of the renal arteryhave become important with the increasing number of renal transplantations. Numerous studies describe variations in renalartery anatomy. Especially the left renal artery is among the most critical arterial variations, because it is the referred side forresecting the donor kidney. During routine dissection in a formalin fixed male cadaver, we have found a bilateral renal...

  4. Genetics and variation

    Science.gov (United States)

    John R. Jones; Norbert V. DeByle

    1985-01-01

    The broad genotypic variability in quaking aspen (Populus tremuloides Michx.), that results in equally broad phenotypic variability among clones is important to the ecology and management of this species. This chapter considers principles of aspen genetics and variation, variation in aspen over its range, and local variation among clones. For a more...

  5. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  6. Detecting P2P Botnet in Software Defined Networks

    Directory of Open Access Journals (Sweden)

    Shang-Chiuan Su

    2018-01-01

    Full Text Available Software Defined Network separates the control plane from network equipment and has great advantage in network management as compared with traditional approaches. With this paradigm, the security issues persist to exist and could become even worse because of the flexibility on handling the packets. In this paper we propose an effective framework by integrating SDN and machine learning to detect and categorize P2P network traffics. This work provides experimental evidence showing that our approach can automatically analyze network traffic and flexibly change flow entries in OpenFlow switches through the SDN controller. This can effectively help the network administrators manage related security problems.

  7. Fusion reactor problems

    International Nuclear Information System (INIS)

    Carruthers, R.

    It is pointed out that plasma parameters for a fusion reactor have been fairly accurately defined for many years, and the real plasma physics objective must be to find the means of achieving and maintaining these specifiable parameters. There is good understanding of the generic technological problems: breading blankets and shields, radiation damage, heat transfer and methods of magnet design. The required plasma parameters for fusion self-heated reactors are established at ntausub(E) approximately 2.10 14 cm -3 sec, plasma radius 1.5 to 3 m, wall loading 5 to 10 MW cm -2 , temperature 15 keV. Within this model plasma control by quasi-steady burn as a key problem is studied. It is emphasized that the future programme must interact more closely with engineering studies and should concentrate upon research which is relevant to reactor plasmas. (V.P.)

  8. Variational principles for the projected breakup amplitude

    International Nuclear Information System (INIS)

    Hahn, Y.

    1976-01-01

    Two alternate forms of variational principles for the breakup amplitude describing the two- to three-cluster transition are derived such that all the integrals involved in the intermediate stages are well defined. The first form contains a trial Green's function with which both the initial and final state trial wave functions are constructed. The earlier form of the Kohn-type variational principle derived by Lieber, Rosenberg, and Spruch is recovered, however, when this connection between the trial functions is removed. The second form of the variational principle is derived by projecting out from the trial functions all the open channel components which correspond to the two-cluster structures including the rearrangement channels. The remaining part of the wave functions describes the channels with three-cluster structures, and the integrals involving this part are then mathematically well defined

  9. Heterogeneous treatment in the variational nodal method

    International Nuclear Information System (INIS)

    Fanning, T.H.

    1995-01-01

    The variational nodal transport method is reduced to its diffusion form and generalized for the treatment of heterogeneous nodes while maintaining nodal balances. Adapting variational methods to heterogeneous nodes requires the ability to integrate over a node with discontinuous cross sections. In this work, integrals are evaluated using composite gaussian quadrature rules, which permit accurate integration while minimizing computing time. Allowing structure within a nodal solution scheme avoids some of the necessity of cross section homogenization, and more accurately defines the intra-nodal flux shape. Ideally, any desired heterogeneity can be constructed within the node; but in reality, the finite set of basis functions limits the practical resolution to which fine detail can be defined within the node. Preliminary comparison tests show that the heterogeneous variational nodal method provides satisfactory results even if some improvements are needed for very difficult, configurations

  10. Variational method for integrating radial gradient field

    Science.gov (United States)

    Legarda-Saenz, Ricardo; Brito-Loeza, Carlos; Rivera, Mariano; Espinosa-Romero, Arturo

    2014-12-01

    We propose a variational method for integrating information obtained from circular fringe pattern. The proposed method is a suitable choice for objects with radial symmetry. First, we analyze the information contained in the fringe pattern captured by the experimental setup and then move to formulate the problem of recovering the wavefront using techniques from calculus of variations. The performance of the method is demonstrated by numerical experiments with both synthetic and real data.

  11. Boundary Value Problems and Approximate Solutions

    African Journals Online (AJOL)

    Tadesse

    Department of Mathematics, College of Natural and Computational Scineces, Mekelle ..... In this section, the Variational Iteration Method is applied to different forms of .... Some problems in non-Newtonian fluid mechanics, Ph.D. thesis, Wales.

  12. Problems of environment pollution in energy production

    International Nuclear Information System (INIS)

    Soyberk, Oe.

    2000-01-01

    This publication relates to nuclear fuel cycle and environment, nuclear accidents, risk analysis, test of nuclear weapon, security problems of nuclear power plants, advantages and disadvantages of energy sources, climate variation due to environment pollution

  13. 1. round table - Nuclear wastes and radioactive materials. 2. round table - risks linked with nuclear wastes and materials. 3. round table - the problem of long-term management of medium-high activity and long lived wastes. The process defined by the 1991 law; 1. table ronde - dechets nucleaires et matieres radioactives. 2. table ronde - Les risques des dechets et matieres nucleaires. 3. table ronde - Le probleme de la gestion a long terme des dechets a MA/HAVL. Le processus defini par la loi de 1991

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The law from December 30, 1991, precisely defines 3 axes of researches for the management of high level and long-lived radioactive wastes: separation/transmutation, surface storage and underground disposal. A global evaluation report about these researches is to be supplied in 2006 by the French government to the Parliament. A first synthesis of the knowledge gained after 14 years of research has led the national commission of the public debate (CNDP) to organize a national debate about the general options of management of high-level and long-lived radioactive wastes before the 2006 date line. The debate comprises 4 public hearings (September 2005: Bar-le-Duc, Saint-Dizier, Pont-du-Gard, Cherbourg), 12 round-tables (October and November 2005: Paris, Joinville, Caen, Nancy, Marseille), a synthesis meeting (December 2005, Dunkerque) and a closing meeting (January 2006, Lyon). This document is the synthesis of the debates of the first round table of Paris about the problems raised by nuclear wastes in the case of the geologic disposal option. Four families of questions have been tackled: 1 - the exhaustiveness of ANDRA's inventory, the solutions foreseen for the different types of wastes; 2 - the high-medium activity wastes and their processing; 3 - the management of non-reprocessed spent MOX fuels; 4 - the safety and security standards used and their establishment. Four presentations are attached to these proceedings and deal with: the measured and estimated inventory of all radioactive wastes; the inventory and management of radioactive wastes and the place of citizens; the point of view of the nuclear safety authority; conditioning and storage. (J.S.)

  14. Child maltreatment and problem gambling: A systematic review.

    Science.gov (United States)

    Lane, Wendy; Sacco, Paul; Downton, Katherine; Ludeman, Emilie; Levy, Lauren; Tracy, J Kathleen

    2016-08-01

    This study systematically reviews research on child maltreatment and risk of gambling problems in adulthood. It also reviews adult problem gamblers' risk of abusing or neglecting their own children. Multiple database searches were conducted using pre-defined search terms related to gambling and child abuse and neglect. We identified 601 unique references and excluded studies if they did not report original research, or did not specifically measure child maltreatment or gambling. Twelve studies that included multivariable analysis of childhood maltreatment exposure and problem gambling were identified. Six of seven studies examining childhood sexual abuse and four of five examining physical abuse showed a significant positive association between abuse and later gambling problems (odds ratios for sexual abuse 2.01-3.65; physical abuse 2.3-2.8). Both studies examining psychological maltreatment and two of three examining neglect identified positive associations with problem gambling. In most studies, risks were reduced or eliminated when controlling for other mental health disorders. The three studies measuring risk of child abuse and neglect among current problem gamblers suggest an increased risk for child physical abuse and medical conditions indicative of neglect although there is a considerable amount of variation among studies. Child abuse is associated with increased risk of gambling problems - gambling treatment providers should ask about maltreatment history as part of their clinical assessment. Problem gamblers may be more likely to physically abuse or neglect their children, but data here are more limited. Child welfare professionals should consider asking questions about parental gambling when assessing family risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Multigrid Reduction in Time for Nonlinear Parabolic Problems

    Energy Technology Data Exchange (ETDEWEB)

    Falgout, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Manteuffel, T. A. [Univ. of Colorado, Boulder, CO (United States); O' Neill, B. [Univ. of Colorado, Boulder, CO (United States); Schroder, J. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-04

    The need for parallel-in-time is being driven by changes in computer architectures, where future speed-ups will be available through greater concurrency, but not faster clock speeds, which are stagnant.This leads to a bottleneck for sequential time marching schemes, because they lack parallelism in the time dimension. Multigrid Reduction in Time (MGRIT) is an iterative procedure that allows for temporal parallelism by utilizing multigrid reduction techniques and a multilevel hierarchy of coarse time grids. MGRIT has been shown to be effective for linear problems, with speedups of up to 50 times. The goal of this work is the efficient solution of nonlinear problems with MGRIT, where efficient is defined as achieving similar performance when compared to a corresponding linear problem. As our benchmark, we use the p-Laplacian, where p = 4 corresponds to a well-known nonlinear diffusion equation and p = 2 corresponds to our benchmark linear diffusion problem. When considering linear problems and implicit methods, the use of optimal spatial solvers such as spatial multigrid imply that the cost of one time step evaluation is fixed across temporal levels, which have a large variation in time step sizes. This is not the case for nonlinear problems, where the work required increases dramatically on coarser time grids, where relatively large time steps lead to worse conditioned nonlinear solves and increased nonlinear iteration counts per time step evaluation. This is the key difficulty explored by this paper. We show that by using a variety of strategies, most importantly, spatial coarsening and an alternate initial guess to the nonlinear time-step solver, we can reduce the work per time step evaluation over all temporal levels to a range similar with the corresponding linear problem. This allows for parallel scaling behavior comparable to the corresponding linear problem.

  16. Hanford defined waste model limitations and improvements

    International Nuclear Information System (INIS)

    HARMSEN, R.W.

    1999-01-01

    Recommendation 93-5 Implementation Plan, Milestone 5,6.3.1.i requires issuance of this report which addresses ''updates to the tank contents model''. This report summarizes the review of the Hanford Defined Waste, Revision 4, model limitations and provides conclusions and recommendations for potential updates to the model

  17. Parallel Education and Defining the Fourth Sector.

    Science.gov (United States)

    Chessell, Diana

    1996-01-01

    Parallel to the primary, secondary, postsecondary, and adult/community education sectors is education not associated with formal programs--learning in arts and cultural sites. The emergence of cultural and educational tourism is an opportunity for adult/community education to define itself by extending lifelong learning opportunities into parallel…

  18. Bruxism defined and graded: an international consensus

    NARCIS (Netherlands)

    Lobbezoo, F.; Ahlberg, J.; Glaros, A.G.; Kato, T.; Koyano, K.; Lavigne, G.J.; de Leeuw, R.; Manfredini, D.; Svensson, P.; Winocur, E.

    2013-01-01

    To date, there is no consensus about the definition and diagnostic grading of bruxism. A written consensus discussion was held among an international group of bruxism experts as to formulate a definition of bruxism and to suggest a grading system for its operationalisation. The expert group defined

  19. 7 CFR 28.950 - Terms defined.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing..., TESTING, AND STANDARDS Cotton Fiber and Processing Tests Definitions § 28.950 Terms defined. As used... Agricultural Marketing Service of the U.S. Department of Agriculture. (c) Administrator. The Administrator of...

  20. 47 CFR 54.401 - Lifeline defined.

    Science.gov (United States)

    2010-10-01

    ... SERVICE Universal Service Support for Low-Income Consumers § 54.401 Lifeline defined. (a) As used in this subpart, Lifeline means a retail local service offering: (1) That is available only to qualifying low-income consumers; (2) For which qualifying low-income consumers pay reduced charges as a result of...

  1. How Should Energy Be Defined throughout Schooling?

    Science.gov (United States)

    Bächtold, Manuel

    2018-01-01

    The question of how to teach energy has been renewed by recent studies focusing on the learning and teaching progressions for this concept. In this context, one question has been, for the most part, overlooked: how should energy be defined throughout schooling? This paper addresses this question in three steps. We first identify and discuss two…

  2. Big data and software defined networks

    CERN Document Server

    Taheri, Javid

    2018-01-01

    Big Data Analytics and Software Defined Networking (SDN) are helping to drive the management of data usage of the extraordinary increase of computer processing power provided by Cloud Data Centres (CDCs). This new book investigates areas where Big-Data and SDN can help each other in delivering more efficient services.

  3. Delta Semantics Defined By Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

    and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

  4. Towards a Southern African English Defining Vocabulary

    African Journals Online (AJOL)

    user

    of parameters, such as avoiding synonyms and antonyms, to determine which words are necessary to write definitions in a concise and simple way. It has been found that existing defining vocabularies lack certain words that would make definitions more accessible to southern African learners, and therefore there is a need ...

  5. Spaces defined by the Paley function

    Energy Technology Data Exchange (ETDEWEB)

    Astashkin, S V [Samara State University, Samara (Russian Federation); Semenov, E M [Voronezh State University, Faculty of Mathematics, Voronezh (Russian Federation)

    2013-07-31

    The paper is concerned with Haar and Rademacher series in symmetric spaces, and also with the properties of spaces defined by the Paley function. In particular, the symmetric hull of the space of functions with uniformly bounded Paley function is found. Bibliography: 27 titles.

  6. Pointwise extensions of GSOS-defined operations

    NARCIS (Netherlands)

    Hansen, H.H.; Klin, B.

    2011-01-01

    Final coalgebras capture system behaviours such as streams, infinite trees and processes. Algebraic operations on a final coalgebra can be defined by distributive laws (of a syntax functor S over a behaviour functor F). Such distributive laws correspond to abstract specification formats. One such

  7. Pointwise Extensions of GSOS-Defined Operations

    NARCIS (Netherlands)

    H.H. Hansen (Helle); B. Klin

    2011-01-01

    textabstractFinal coalgebras capture system behaviours such as streams, infinite trees and processes. Algebraic operations on a final coalgebra can be defined by distributive laws (of a syntax functor $\\FSig$ over a behaviour functor $F$). Such distributive laws correspond to abstract specification

  8. Defining Virtual Reality: Dimensions Determining Telepresence.

    Science.gov (United States)

    Steuer, Jonathan

    1992-01-01

    Defines virtual reality as a particular type of experience (in terms of "presence" and "telepresence") rather than as a collection of hardware. Maintains that media technologies can be classified and studied in terms of vividness and interactivity, two attributes on which virtual reality ranks very high. (SR)

  9. A self-defining hierarchical data system

    Science.gov (United States)

    Bailey, J.

    1992-01-01

    The Self-Defining Data System (SDS) is a system which allows the creation of self-defining hierarchical data structures in a form which allows the data to be moved between different machine architectures. Because the structures are self-defining they can be used for communication between independent modules in a distributed system. Unlike disk-based hierarchical data systems such as Starlink's HDS, SDS works entirely in memory and is very fast. Data structures are created and manipulated as internal dynamic structures in memory managed by SDS itself. A structure may then be exported into a caller supplied memory buffer in a defined external format. This structure can be written as a file or sent as a message to another machine. It remains static in structure until it is reimported into SDS. SDS is written in portable C and has been run on a number of different machine architectures. Structures are portable between machines with SDS looking after conversion of byte order, floating point format, and alignment. A Fortran callable version is also available for some machines.

  10. Periodic weather and climate variations

    International Nuclear Information System (INIS)

    Ivanov, Vladimir V

    2002-01-01

    Variations in meteorological parameters are largely due to periodic processes and can be forecast for several years. Many such processes are related to astronomical factors such as the gravitational influences of the Moon and the Sun, and the modulation of solar irradiance by lunar and planetary motion. The Moon, Jupiter, and Venus have the strongest effect. These influences produce lines in the spectra of meteorological variations, which are combinations of the harmonics of the frequencies of revolution of the planets, the Earth, and the Moon around the Sun with the harmonics of the lunar revolution around the Earth. Due to frequency differences between the orbital and radial motions, fine spectral features of three types appear: line splitting, line-profile complications due to radial oscillations, and additional lines due to the combination of radial-oscillation frequencies with perturbation harmonics. (reviews of topical problems)

  11. VARIATIONAL PRINCIPLE FOR PLANETARY INTERIORS

    International Nuclear Information System (INIS)

    Zeng, Li; Jacobsen, Stein B.

    2016-01-01

    In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. The variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory, which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying the variational principle to the planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From this principle, a universal mass–radius relation, an estimate of the error propagation from the equation of state to the mass–radius relation, and a form of the virial theorem applicable to planetary interiors are derived.

  12. Hybrid Iterative Scheme for Triple Hierarchical Variational Inequalities with Mixed Equilibrium, Variational Inclusion, and Minimization Constraints

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We introduce and analyze a hybrid iterative algorithm by combining Korpelevich's extragradient method, the hybrid steepest-descent method, and the averaged mapping approach to the gradient-projection algorithm. It is proven that, under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of finitely many nonexpansive mappings, the solution set of a generalized mixed equilibrium problem (GMEP, the solution set of finitely many variational inclusions, and the solution set of a convex minimization problem (CMP, which is also a unique solution of a triple hierarchical variational inequality (THVI in a real Hilbert space. In addition, we also consider the application of the proposed algorithm to solving a hierarchical variational inequality problem with constraints of the GMEP, the CMP, and finitely many variational inclusions.

  13. An introduction to the calculus of variations

    CERN Document Server

    Pars, LA

    2009-01-01

    This clear, rigorous introduction to the calculus of variations covers applications to geometry, dynamics, and physics. Focusing upon problems with one independent variable, the text connects the abstract theory to its use in concrete problems. It offers a working knowledge of relevant techniques, plus an impetus for further study.Starting with an overview of fundamental problems and theories, the text advances to illustrative examples and examinations of variable end-points and the fundamental sufficiency theorem. Subsequent chapters explore the isoperimetrical problem, curves in space, the p

  14. Variational problem with complex coefficient of a nonlinear ...

    Indian Academy of Sciences (India)

    1Department of Mathematics, Faculty of Arts and Science, Kafkas University, ..... Applying the Cauchy–Bunyakowski inequality to this equality and using the estimates ..... Firstly, let us show that the gradient Jα is continuous on the set V, i.e..

  15. To the problem of DQ Herculis orbital period variations.

    Science.gov (United States)

    Dmitrienko, E. S.

    The eclipses of the primary component by the secondary one in DQ Her (Nova Her 1934) were analyzed using the light curves obtained by photometrical observations in 1982 - 1986. It is suspected that the value O-C is varying with time according to a sinusoidal law with the period of about 5 years and the amplitude ≡3 - 4 min. The secondary minimum is not shown up on the UBVRI-light curves of DQ Her. That is why the two hypotheses - the apsidal motion and the third component in the system - would seem adequate to explain the sinusoidal change of the value "O-C". By assuming that a probable sinusoidal dependence O-C on time occurs due to apsidal motion, it can be a result of deformation of the secondary component shape, since the contribution from the relativistic motion does not exceed 5%. The obtained value of k2 for the models with zero viscosity is (1 - 5)×10-3 that corresponds to a very high concentration of stellar matter toward the centre of the star. Application of models with the viscosity not equal to zero must lead to the increase of the k2 parameter.

  16. Linear-programming approach to nonconvex variational problems

    Czech Academy of Sciences Publication Activity Database

    Bartels, S.; Roubíček, Tomáš

    2004-01-01

    Roč. 99, č. 2 (2004), s. 251-287 ISSN 0029-599X R&D Projects: GA AV ČR IAA1075005 Institutional research plan: CEZ:AV0Z1075907 Keywords : young measures * convex approximations * adaptive scheme Subject RIV: BA - General Mathematics Impact factor: 1.011, year: 2004

  17. Total Variation Regularization for Functions with Values in a Manifold

    KAUST Repository

    Lellmann, Jan; Strekalovskiy, Evgeny; Koetter, Sabrina; Cremers, Daniel

    2013-01-01

    While total variation is among the most popular regularizers for variational problems, its extension to functions with values in a manifold is an open problem. In this paper, we propose the first algorithm to solve such problems which applies to arbitrary Riemannian manifolds. The key idea is to reformulate the variational problem as a multilabel optimization problem with an infinite number of labels. This leads to a hard optimization problem which can be approximately solved using convex relaxation techniques. The framework can be easily adapted to different manifolds including spheres and three-dimensional rotations, and allows to obtain accurate solutions even with a relatively coarse discretization. With numerous examples we demonstrate that the proposed framework can be applied to variational models that incorporate chromaticity values, normal fields, or camera trajectories. © 2013 IEEE.

  18. Total Variation Regularization for Functions with Values in a Manifold

    KAUST Repository

    Lellmann, Jan

    2013-12-01

    While total variation is among the most popular regularizers for variational problems, its extension to functions with values in a manifold is an open problem. In this paper, we propose the first algorithm to solve such problems which applies to arbitrary Riemannian manifolds. The key idea is to reformulate the variational problem as a multilabel optimization problem with an infinite number of labels. This leads to a hard optimization problem which can be approximately solved using convex relaxation techniques. The framework can be easily adapted to different manifolds including spheres and three-dimensional rotations, and allows to obtain accurate solutions even with a relatively coarse discretization. With numerous examples we demonstrate that the proposed framework can be applied to variational models that incorporate chromaticity values, normal fields, or camera trajectories. © 2013 IEEE.

  19. An Initial Load-Based Green Software Defined Network

    Directory of Open Access Journals (Sweden)

    Ying Hu

    2017-05-01

    Full Text Available Software defined network (SDN is a new network architecture in which the control function is decoupled from the data forwarding plane, that is attracting wide attentions from both research and industry sectors. However, SDN still faces the energy waste problem as do traditional networks. At present, research on energy saving in SDN is mainly focused on the static optimization of the network with zero load when new traffic arrives, changing the transmission path of the uncompleted traffic which arrived before the optimization, possibly resulting in route oscillation and other deleterious effects. To avoid this, a dynamical energy saving optimization scheme in which the paths of the uncompleted flows will not be changed when new traffic arrives is designed. To find the optimal solution for energy saving, the problem is modeled as a mixed integer linear programming (MILP problem. As the high complexity of the problem prohibits the optimal solution, an improved heuristic routing algorithm called improved constant weight greedy algorithm (ICWGA is proposed to find a sub-optimal solution. Simulation results show that the energy saving capacity of ICWGA is close to that of the optimal solution, offering desirable improvement in the energy efficiency of the network.

  20. Variation Tolerant On-Chip Interconnects

    CERN Document Server

    Nigussie, Ethiopia Enideg

    2012-01-01

    This book presents design techniques, analysis and implementation of high performance and power efficient, variation tolerant on-chip interconnects.  Given the design paradigm shift to multi-core, interconnect-centric designs and the increase in sources of variability and their impact in sub-100nm technologies, this book will be an invaluable reference for anyone concerned with the design of next generation, high-performance electronics systems. Provides comprehensive, circuit-level explanation of high-performance, energy-efficient, variation-tolerant on-chip interconnect; Describes design techniques to mitigate problems caused by variation; Includes techniques for design and implementation of self-timed on-chip interconnect, delay variation insensitive communication protocols, high speed signaling techniques and circuits, bit-width independent completion detection and process, voltage and temperature variation tolerance.                          

  1. Variational theory of nuclear and neutron matter

    International Nuclear Information System (INIS)

    Pandharipande, V.R.; Wiringa, R.B.

    1989-06-01

    In these lectures we will discuss attempts to solve the A = 3 to ∞ nuclear many-body problems with the variational method. We choose the form of a variational wave function Χ v (1, 2 hor-ellipsis A) to describe the ground state. The Χ v and the ground-state energy E v are obtained by minimizing E v = left-angle Χ v |H|Χ v right-angle/left-angle Χ v |Χ v right-angle with respect to variations in Χ v . If the form of the variational wave function is chosen properly we can expect Χ v ∼ Χ 0 and E v ∼ E 0 where Χ 0 and E 0 are the exact ground-state wave function and energy. In general E v ≥ E 0 in variational calculations. 63 refs., 11 figs

  2. On Labeled Traveling Salesman Problems

    DEFF Research Database (Denmark)

    Couetoux, Basile; Gourves, Laurent; Monnot, Jerome

    2008-01-01

    We consider labeled Traveling Salesman Problems, defined upon a complete graph of n vertices with colored edges. The objective is to find a tour of maximum (or minimum) number of colors. We derive results regarding hardness of approximation, and analyze approximation algorithms for both versions ...

  3. Unambiguous results from variational matrix Pade approximants

    International Nuclear Information System (INIS)

    Pindor, Maciej.

    1979-10-01

    Variational Matrix Pade Approximants are studied as a nonlinear variational problem. It is shown that although a stationary value of the Schwinger functional is a stationary value of VMPA, the latter has also another stationary value. It is therefore proposed that instead of looking for a stationary point of VMPA, one minimizes some non-negative functional and then one calculates VMPA at the point where the former has the absolute minimum. This approach, which we call the Method of the Variational Gradient (MVG) gives unambiguous results and is also shown to minimize a distance between the approximate and the exact stationary values of the Schwinger functional

  4. Variational form for a viscous plasma

    International Nuclear Information System (INIS)

    Ishida, A.; Steinhauer, L.C.; Berk, H.L.

    1991-01-01

    The variational formulation for a fluid plasma including the parallel and gyroviscosities is developed using the basic approach of Berk et al. [Phys. Fluids 24, 2245 (1981)]. The equivalence of the variational problem to the original viscous fluid equations of motion is shown. The theory is developed for an axisymmetric plasma with no magnetic field in the azimuthal direction and therefore applies to field-reversed configurations and axisymmetric mirrors. This theory offers the advantage of describing both parallel and transverse ion kinetic effects within the simplicity afforded by a variational fluid model

  5. Variational constraints for electrical-impedance tomography

    International Nuclear Information System (INIS)

    Berryman, J.G.; Kohn, R.V.

    1990-01-01

    The task of electrical-impedance tomography is to invert boundary measurements for the conductivity distribution of a body. This inverse problem can be formulated so the primary data are the measured powers dissipated across injection electrodes. Then, since these powers are minima of the pertinent (dual) variational principles, feasibility constraints can be found for the nonlinear inversion problem. When power may be measured accurately, the existence of these dual variational principles implies that any exact solution must lie at a point of intersection of the two feasibility boundaries

  6. Solar ultraviolet irradiance variations: a review

    International Nuclear Information System (INIS)

    Lean, J.

    1987-01-01

    Despite the geophysical importance of solar ultraviolet radiation, specific aspects of its temporal variations have not yet been adequately determined experimentally, nor are the mechanisms for the variability completely understood. Satellite observations have verified the reality of solar ultraviolet irradiance variations over time scales of days and months, and model calculations have confirmed the association of these short-term variations with the evolution and rotation of regions of enhanced magnetic activity on the solar disc. However, neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11-year solar cycle. The comparative importance for the long-term variations of local regions of enhanced magnetic activity and global scale activity perturbations is still being investigated. Solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. Correlations with ground-based measures of solar variability are examined because of the importance of the ground-based observations as historical proxies of ultraviolet irradiance variations. Current problems in understanding solar ultraviolet irradiance variations are discussed, and the measurements planned for solar cycle 22, which may resolve these problems, are briefly described. copyright American Geophysical Union 1987

  7. Errors in data interpretation from genetic variation of human analytes

    OpenAIRE

    Howie, Heather L.; Delaney, Meghan; Wang, Xiaohong; Er, Lay See; Kapp, Linda; Lebedev, Jenna N.; Zimring, James C.

    2017-01-01

    In recent years, the extent of our vulnerability to misinterpretation due to poorly characterized reagents has become an issue of great concern. Antibody reagents have been identified as a major source of error, contributing to the ?reproducibility crisis.? In the current report, we define an additional dimension of the crisis; in particular, we define variation of the targets being analyzed. We report that natural variation in the immunoglobulin ?constant? region alters the reactivity with c...

  8. Vector optimization set-valued and variational analysis

    CERN Document Server

    Chen, Guang-ya; Yang, Xiaogi

    2005-01-01

    This book is devoted to vector or multiple criteria approaches in optimization. Topics covered include: vector optimization, vector variational inequalities, vector variational principles, vector minmax inequalities and vector equilibrium problems. In particular, problems with variable ordering relations and set-valued mappings are treated. The nonlinear scalarization method is extensively used throughout the book to deal with various vector-related problems. The results presented are original and should be interesting to researchers and graduates in applied mathematics and operations research

  9. Influence of Design Variations on Systems Performance

    Science.gov (United States)

    Tumer, Irem Y.; Stone, Robert B.; Huff, Edward M.; Norvig, Peter (Technical Monitor)

    2000-01-01

    High-risk aerospace components have to meet very stringent quality, performance, and safety requirements. Any source of variation is a concern, as it may result in scrap or rework. poor performance, and potentially unsafe flying conditions. The sources of variation during product development, including design, manufacturing, and assembly, and during operation are shown. Sources of static and dynamic variation during development need to be detected accurately in order to prevent failure when the components are placed in operation. The Systems' Health and Safety (SHAS) research at the NASA Ames Research Center addresses the problem of detecting and evaluating the statistical variation in helicopter transmissions. In this work, we focus on the variations caused by design, manufacturing, and assembly of these components, prior to being placed in operation (DMV). In particular, we aim to understand and represent the failure and variation information, and their correlation to performance and safety and feed this information back into the development cycle at an early stage. The feedback of such critical information will assure the development of more reliable components with less rework and scrap. Variations during design and manufacturing are a common source of concern in the development and production of such components. Accounting for these variations, especially those that have the potential to affect performance, is accomplished in a variety ways, including Taguchi methods, FMEA, quality control, statistical process control, and variation risk management. In this work, we start with the assumption that any of these variations can be represented mathematically, and accounted for by using analytical tools incorporating these mathematical representations. In this paper, we concentrate on variations that are introduced during design. Variations introduced during manufacturing are investigated in parallel work.

  10. Stability analysis of an implicitly defined labor market model

    Science.gov (United States)

    Mendes, Diana A.; Mendes, Vivaldo M.

    2008-06-01

    Until very recently, the pervasive existence of models exhibiting well-defined backward dynamics but ill-defined forward dynamics in economics and finance has apparently posed no serious obstacles to the analysis of their dynamics and stability, despite the problems that may arise from possible erroneous conclusions regarding theoretical considerations and policy prescriptions from such models. A large number of papers have dealt with this problem in the past by assuming the existence of symmetry between forward and backward dynamics, even in the case when the map cannot be invertible either forward or backwards. However, this procedure has been seriously questioned over the last few years in a series of papers dealing with implicit difference equations and inverse limit spaces. This paper explores the search and matching labor market model developed by Bhattacharya and Bunzel [J. Bhattacharya, H. Bunzel, Chaotic Planning Solution in the Textbook Model of Equilibrium Labor Market Search and Matching, Mimeo, Iowa State University, 2002; J. Bhattacharya, H. Bunzel, Economics Bulletin 5 (19) (2003) 1-10], with the following objectives in mind: (i) to show that chaotic dynamics may still be present in the model for acceptable parameter values, (ii) to clarify some open questions related with the admissible dynamics in the forward looking setting, by providing a rigorous proof of the existence of cyclic and chaotic dynamics through the application of tools from symbolic dynamics and inverse limit theory.

  11. Software-Defined Congestion Control Algorithm for IP Networks

    Directory of Open Access Journals (Sweden)

    Yao Hu

    2017-01-01

    Full Text Available The rapid evolution of computer networks, increase in the number of Internet users, and popularity of multimedia applications have exacerbated the congestion control problem. Congestion control is a key factor in ensuring network stability and robustness. When the underlying network and flow information are unknown, the transmission control protocol (TCP must increase or reduce the size of the congestion window to adjust to the changes of traffic in the Internet Protocol (IP network. However, it is possible that a software-defined approach can relieve the network congestion problem more efficiently. This approach has the characteristic of centralized control and can obtain a global topology for unified network management. In this paper, we propose a software-defined congestion control (SDCC algorithm for an IP network. We consider the difference between TCP and the user datagram protocol (UDP and propose a new method to judge node congestion. We initially apply the congestion control mechanism in the congested nodes and then optimize the link utilization to control network congestion.

  12. Bayesian Image Restoration Using a Large-Scale Total Patch Variation Prior

    Directory of Open Access Journals (Sweden)

    Yang Chen

    2011-01-01

    Full Text Available Edge-preserving Bayesian restorations using nonquadratic priors are often inefficient in restoring continuous variations and tend to produce block artifacts around edges in ill-posed inverse image restorations. To overcome this, we have proposed a spatial adaptive (SA prior with improved performance. However, this SA prior restoration suffers from high computational cost and the unguaranteed convergence problem. Concerning these issues, this paper proposes a Large-scale Total Patch Variation (LS-TPV Prior model for Bayesian image restoration. In this model, the prior for each pixel is defined as a singleton conditional probability, which is in a mixture prior form of one patch similarity prior and one weight entropy prior. A joint MAP estimation is thus built to ensure the iteration monotonicity. The intensive calculation of patch distances is greatly alleviated by the parallelization of Compute Unified Device Architecture(CUDA. Experiments with both simulated and real data validate the good performance of the proposed restoration.

  13. Defining Tiger Parenting in Chinese Americans.

    Science.gov (United States)

    Kim, Su Yeong

    2013-09-01

    "Tiger" parenting, as described by Amy Chua [2011], has instigated scholarly discourse on this phenomenon and its possible effects on families. Our eight-year longitudinal study, published in the Asian American Journal of Psychology [Kim, Wang, Orozco-Lapray, Shen, & Murtuza, 2013b], demonstrates that tiger parenting is not a common parenting profile in a sample of 444 Chinese American families. Tiger parenting also does not relate to superior academic performance in children. In fact, the best developmental outcomes were found among children of supportive parents. We examine the complexities around defining tiger parenting by reviewing classical literature on parenting styles and scholarship on Asian American parenting, along with Amy Chua's own description of her parenting method, to develop, define, and categorize variability in parenting in a sample of Chinese American families. We also provide evidence that supportive parenting is important for the optimal development of Chinese American adolescents.

  14. Defining enthesitis in spondyloarthritis by ultrasound

    DEFF Research Database (Denmark)

    Terslev, Lene; Naredo, E; Iagnocco, A

    2014-01-01

    Objective: To standardize ultrasound (US) in enthesitis. Methods: An Initial Delphi exercise was undertaken to define US detected enthesitis and its core components. These definitions were subsequently tested on static images taken from Spondyloarthritis (SpA) patients in order to evaluate...... elementary component. On static images the intra-observer reliability showed a high degree of variability for the detection of elementary lesions with kappa coefficients ranging from 0.14 - 1. The inter-observer kappa value was variable with the lowest kappa for enthesophytes (0.24) and the best for Doppler...... activity at the enthesis (0.63). Conclusion: This is the first consensus based definition of US enthesitis and its elementary components and the first step performed to ensure a higher degree of homogeneity and comparability of results between studies and in daily clinical work. Defining Enthesitis...

  15. FINANCIAL ACCOUNTING QUALITY AND ITS DEFINING CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Andra M. ACHIM

    2014-11-01

    Full Text Available The importance ofhigh-quality financial statements is highlighted by the main standard-setting institutions activating in the field of accounting and reporting. These have issued Conceptual Frameworks which state and describe the qualitative characteristics of accounting information. In this qualitative study, the research methodology consists of reviewing the literature related to the definition of accounting quality and striving for understanding how it can be explained. The main objective of the study is to identify the characteristics information should possess in order to be of high quality. These characteristics also contribute to the way of defining financial accounting quality. The main conclusions that arise from this research are represented by the facts that indeed financial accounting quality cannot be uniquely defined and that financial information is of good quality when it enhances the characteristics incorporated in the conceptual frameworks issued by both International Accounting Standards Board and Financial Accounting Standards Board.

  16. Exploring self-defining memories in schizophrenia.

    Science.gov (United States)

    Raffard, Stéphane; D'Argembeau, Arnaud; Lardi, Claudia; Bayard, Sophie; Boulenger, Jean-Philippe; Van Der Linden, Martial

    2009-01-01

    Previous studies have shown that patients with schizophrenia are impaired in recalling specific events from their personal past. However, the relationship between autobiographical memory impairments and disturbance of the sense of identity in schizophrenia has not been investigated in detail. In this study the authors investigated schizophrenic patients' ability to recall self-defining memories; that is, memories that play an important role in building and maintaining the self-concept. Results showed that patients recalled as many specific self-defining memories as healthy participants. However, patients with schizophrenia exhibited an abnormal reminiscence bump and reported different types of thematic content (i.e., they recalled less memories about past achievements and more memories regarding hospitalisation and stigmatisation of illness). Furthermore, the findings suggest that impairments in extracting meaning from personal memories could represent a core disturbance of autobiographical memory in patients with schizophrenia.

  17. Stateless multicast switching in software defined networks

    OpenAIRE

    Reed, Martin J.; Al-Naday, Mays; Thomos, Nikolaos; Trossen, Dirk; Petropoulos, George; Spirou, Spiros

    2016-01-01

    Multicast data delivery can significantly reduce traffic in operators' networks, but has been limited in deployment due to concerns such as the scalability of state management. This paper shows how multicast can be implemented in contemporary software defined networking (SDN) switches, with less state than existing unicast switching strategies, by utilising a Bloom Filter (BF) based switching technique. Furthermore, the proposed mechanism uses only proactive rule insertion, and thus, is not l...

  18. Defining and Distinguishing Traditional and Religious Terrorism

    OpenAIRE

    Gregg, Heather S.

    2014-01-01

    The article of record may be found at: http://dx.doi.org/10.1080/23296151.2016.1239978 thus offering few if any policy options for counterterrorism measures. This assumption about religious terrorism stems from two challenges in the literature: disproportionate attention to apocalyptic terrorism, and a lack of distinction between religious terrorism and its secular counterpart. This article, therefore, aims to do four things: define and differentiate religiously motivated terrorism from tr...

  19. Defining Trust Using Expected Utility Theory

    OpenAIRE

    Arai, Kazuhiro

    2009-01-01

    Trust has been discussed in many social sciences including economics, psychology, and sociology. However, there is no widely accepted definition of trust. Inparticular, there is no definition that can be used for economic analysis. This paper regards trust as expectation and defines it using expected utility theory together with concepts such as betrayal premium. In doing so, it rejects the widely accepted black-and-white view that (un) trustworthy people are always (un)trustworthy. This pape...

  20. On Undefined and Meaningless in Lambda Definability

    OpenAIRE

    de Vries, Fer-Jan

    2016-01-01

    We distinguish between undefined terms as used in lambda definability of partial recursive functions and meaningless terms as used in infinite lambda calculus for the infinitary terms models that generalise the Bohm model. While there are uncountable many known sets of meaningless terms, there are four known sets of undefined terms. Two of these four are sets of meaningless terms. In this paper we first present set of sufficient conditions for a set of lambda terms to se...