Inner Functions in Lipschitz, Besov, and Sobolev Spaces

Directory of Open Access Journals (Sweden)

Daniel Girela

2011-01-01

Full Text Available We study the membership of inner functions in Besov, Lipschitz, and Hardy-Sobolev spaces, finding conditions that enable an inner function to be in one of these spaces. Several results in this direction are given that complement or extend previous works on the subject from different authors. In particular, we prove that the only inner functions in either any of the Hardy-Sobolev spaces Hαp with 1/p≤α<∞ or any of the Besov spaces Bαp,  q with 0spaces B0∞,q, 0space VMOA. We prove also that for 2space contains infinite Blaschke products. Furthermore, we obtain distinct results for other values of α relating the membership of an inner function I in the spaces under consideration with the distribution of the sequences of preimages {I-1(a}, |a|<1. In addition, we include a section devoted to Blaschke products with zeros in a Stolz angle.

A direct proof of Sobolev embeddings for Triebel-Lizorkin spaces, including mixed norms and quasi-homogeneity

DEFF Research Database (Denmark)

Johnsen, Jon

The article deals with a simplified proof of the Sobolev embedding theorem for Triebel-Lizorkin spaces (that contain the $L_p$-Sobolev spaces $H^s_p$ as special cases). The method extends to a proof of the corresponding fact for general Triebel–Lizorkin spaces based on mixed $L_p$-norms...

A Numerical Framework for Sobolev Metrics on the Space of Curves

DEFF Research Database (Denmark)

Bauer, Martin; Bruveris, Martins; Harms, Philipp

2017-01-01

Statistical shape analysis can be done in a Riemannian framework by endowing the set of shapes with a Riemannian metric. Sobolev metrics of order two and higher on shape spaces of parametrized or unparametrized curves have several desirable properties not present in lower order metrics...

A Note on Generalized Hardy-Sobolev Inequalities

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T. V. Anoop

2013-01-01

Full Text Available We are concerned with finding a class of weight functions g so that the following generalized Hardy-Sobolev inequality holds: ∫Ωgu2≤C∫Ω|∇u|2,   u∈H01(Ω, for some C>0, where Ω is a bounded domain in ℝ2. By making use of Muckenhoupt condition for the one-dimensional weighted Hardy inequalities, we identify a rearrangement invariant Banach function space so that the previous integral inequality holds for all weight functions in it. For weights in a subspace of this space, we show that the best constant in the previous inequality is attained. Our method gives an alternate way of proving the Moser-Trudinger embedding and its refinement due to Hansson.

Numerical Solutions of Singularly Perturbed Reaction Diffusion Equation with Sobolev Gradients

Directory of Open Access Journals (Sweden)

Nauman Raza

2013-01-01

Full Text Available Critical points related to the singular perturbed reaction diffusion models are calculated using weighted Sobolev gradient method in finite element setting. Performance of different Sobolev gradients has been discussed for varying diffusion coefficient values. A comparison is shown between the weighted and unweighted Sobolev gradients in two and three dimensions. The superiority of the method is also demonstrated by showing comparison with Newton's method.

On grand and small Lebesgue and Sobolev spaces and some applications to PDEs

Czech Academy of Sciences Publication Activity Database

Fiorenza, A.; Formica, M. R.; Gogatishvili, Amiran

2018-01-01

Roč. 10, č. 1 (2018), s. 21-46 ISSN 1847-120X R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : grand Lebesgue spaces * small Lebesgue spaces * interpolation Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics http://dea.ele-math.com/10-03/On-grand-and-small-Lebesgue-and-Sobolev-spaces-and-some-applications-to-PDE-s

Generalized Lions-Peetre interpolation construction and optimal embedding theorems for Sobolev spaces

International Nuclear Information System (INIS)

Ovchinnikov, V I

2014-01-01

In the paper, a new description of the generalized Lions-Peetre method of means is found, which enables one to evaluate the interpolation orbits of spaces constructed by this method. The list of these spaces includes all Lorentz spaces with functional parameters, Orlicz spaces, and spaces close to them. This leads in turn to new optimal embedding theorems for Sobolev spaces produced using the Lions-Peetre construction in rearrangement invariant spaces. It turns out that the optimal space of the embedding is also a generalized Lions-Peetre space whose parameters are explicitly evaluated. Bibliography: 18 titles

Long-Time Behavior and Critical Limit of Subcritical SQG Equations in Scale-Invariant Sobolev Spaces

Science.gov (United States)

Coti Zelati, Michele

2018-02-01

We consider the subcritical SQG equation in its natural scale-invariant Sobolev space and prove the existence of a global attractor of optimal regularity. The proof is based on a new energy estimate in Sobolev spaces to bootstrap the regularity to the optimal level, derived by means of nonlinear lower bounds on the fractional Laplacian. This estimate appears to be new in the literature and allows a sharp use of the subcritical nature of the L^∞ bounds for this problem. As a by-product, we obtain attractors for weak solutions as well. Moreover, we study the critical limit of the attractors and prove their stability and upper semicontinuity with respect to the strength of the diffusion.

Sobolev gradients and differential equations

CERN Document Server

Neuberger, J W

2010-01-01

A Sobolev gradient of a real-valued functional on a Hilbert space is a gradient of that functional taken relative to an underlying Sobolev norm. This book shows how descent methods using such gradients allow a unified treatment of a wide variety of problems in differential equations. For discrete versions of partial differential equations, corresponding Sobolev gradients are seen to be vastly more efficient than ordinary gradients. In fact, descent methods with these gradients generally scale linearly with the number of grid points, in sharp contrast with the use of ordinary gradients. Aside from the first edition of this work, this is the only known account of Sobolev gradients in book form. Most of the applications in this book have emerged since the first edition was published some twelve years ago. What remains of the first edition has been extensively revised. There are a number of plots of results from calculations and a sample MatLab code is included for a simple problem. Those working through a fair p...

Existence of weak solutions in lower order Sobolev space for a Camassa-Holm-type equation

International Nuclear Information System (INIS)

Lai Shaoyong; Wu Yonghong

2010-01-01

A generalized Camassa-Holm equation containing a nonlinear dissipative effect is investigated. The existence of the weak solution of the equation in lower order Sobolev space H s with 1

Exterior domain problems and decomposition of tensor fields in weighted Sobolev spaces

OpenAIRE

Schwarz, Günter

1996-01-01

The Hodge decompOsition is a useful tool for tensor analysis on compact manifolds with boundary. This paper aims at generalising the decomposition to exterior domains G ⊂ IR n. Let L 2a Ω k(G) be the space weighted square integrable differential forms with weight function (1 + |χ|²)a, let d a be the weighted perturbation of the exterior derivative and δ a its adjoint. Then L 2a Ω k(G) splits into the orthogonal sum of the subspaces of the d a-exact forms with vanishi...

On dimension-free Sobolev imbeddings II

Czech Academy of Sciences Publication Activity Database

Krbec, Miroslav; Schmeisser, H.-J.

2012-01-01

Roč. 25, č. 1 (2012), s. 247-265 ISSN 1139-1138 R&D Projects: GA ČR GAP201/10/1920 Institutional research plan: CEZ:AV0Z10190503 Keywords : Sobolev space * imbedding theorem * uncertainty principle Subject RIV: BA - General Mathematics Impact factor: 0.377, year: 2012 http://www.springerlink.com/content/0228856047016606/

Approximate controllability of Sobolev type fractional stochastic nonlocal nonlinear differential equations in Hilbert spaces

Directory of Open Access Journals (Sweden)

Mourad Kerboua

2014-12-01

Full Text Available We introduce a new notion called fractional stochastic nonlocal condition, and then we study approximate controllability of class of fractional stochastic nonlinear differential equations of Sobolev type in Hilbert spaces. We use Hölder's inequality, fixed point technique, fractional calculus, stochastic analysis and methods adopted directly from deterministic control problems for the main results. A new set of sufficient conditions is formulated and proved for the fractional stochastic control system to be approximately controllable. An example is given to illustrate the abstract results.

A note on the zeros of Freud-Sobolev orthogonal polynomials

Science.gov (United States)

Moreno-Balcazar, Juan J.

2007-10-01

We prove that the zeros of a certain family of Sobolev orthogonal polynomials involving the Freud weight function e-x4 on are real, simple, and interlace with the zeros of the Freud polynomials, i.e., those polynomials orthogonal with respect to the weight function e-x4. Some numerical examples are shown.

Mixed Norm Estimate for Radon Transform on Weighted $ L^ p ...

Indian Academy of Sciences (India)

We will discuss about the mapping property of Radon transform on L p spaces with power weight. It will be shown that the Pitt's inequality together with the weighted version of Hardy–Littlewood–Sobolev lemma imply weighted inequality for the Radon transform.

On the constants for some Sobolev imbeddings

Directory of Open Access Journals (Sweden)

Pizzocchero Livio

2001-01-01

Full Text Available We consider the imbedding inequality is the Sobolev space (or Bessel potential space of type and (integer or fractional order . We write down upper bounds for the constants , using an argument previously applied in the literature in particular cases. We prove that the upper bounds computed in this way are in fact the sharp constants if , , and exhibit the maximising functions. Furthermore, using convenient trial functions, we derive lower bounds on for in many cases these are close to the previous upper bounds, as illustrated by a number of examples, thus characterizing the sharp constants with little uncertainty.

Avangardistid Moskvas / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

2000-01-01

Valdek Alberi ja Taave Tuutma videoinstallatsioonist "Think different" näitusel "Salon 2000" Moskva Kunstnike Keskmajas 16.-26. III. Kuraator Mari Sobolev. Eesti väljapaneku vastukajast ja Jüri Arrakust, kelle maalid olid näitusel "Balti meistrid", ajalehes "Kommersant". Moskva kunstinäitustest.

Well posedness and regularity for heat equation with the initial condition in weighted Orlitz-Slobodetskii space subordinated to Orlicz space like lambda (log lambda0alpha and the logarithmic weight

Czech Academy of Sciences Publication Activity Database

Kałamajska, A.; Krbec, Miroslav

2015-01-01

Roč. 28, č. 3 (2015), s. 677-713 ISSN 1139-1138 R&D Projects: GA ČR GAP201/10/1920 Institutional research plan: CEZ:AV0Z1019905 Keywords : evolution problems * heat equation * Orlitz-Slobodetskii spaces * Orlitz-Sobolev spaces Subject RIV: BA - General Mathematics Impact factor: 0.631, year: 2015 http://link.springer.com/article/10.1007%2Fs13163-014-0164-4

Salt-body Inversion with Minimum Gradient Support and Sobolev Space Norm Regularizations

KAUST Repository

Kazei, Vladimir

2017-05-26

Full-waveform inversion (FWI) is a technique which solves the ill-posed seismic inversion problem of fitting our model data to the measured ones from the field. FWI is capable of providing high-resolution estimates of the model, and of handling wave propagation of arbitrary complexity (visco-elastic, anisotropic); yet, it often fails to retrieve high-contrast geological structures, such as salt. One of the reasons for the FWI failure is that the updates at earlier iterations are too smooth to capture the sharp edges of the salt boundary. We compare several regularization approaches, which promote sharpness of the edges. Minimum gradient support (MGS) regularization focuses the inversion on blocky models, even more than the total variation (TV) does. However, both approaches try to invert undesirable high wavenumbers in the model too early for a model of complex structure. Therefore, we apply the Sobolev space norm as a regularizing term in order to maintain a balance between sharp and smooth updates in FWI. We demonstrate the application of these regularizations on a Marmousi model, enriched by a chunk of salt. The model turns out to be too complex in some parts to retrieve its full velocity distribution, yet the salt shape and contrast are retrieved.

Quasi-invariant modified Sobolev norms for semi linear reversible PDEs

International Nuclear Information System (INIS)

Faou, Erwan; Grébert, Benoît

2010-01-01

We consider a general class of infinite dimensional reversible differential systems. Assuming a nonresonance condition on linear frequencies, we construct for such systems almost invariant pseudo-norms that are close to Sobolev-like norms. This allows us to prove that if the Sobolev norm of index s of the initial data z 0 is sufficiently small (of order ε) then the Sobolev norm of the solution is bounded by 2ε over a very long time interval (of order ε −r with r arbitrary). It turns out that this theorem applies to a large class of reversible semi-linear partial differential equations (PDEs) including the nonlinear Schrödinger (NLS) equation on the d-dimensional torus. We also apply our method to a system of coupled NLS equations which is reversible but not Hamiltonian. We also note that for the same class of reversible systems we can prove a Birkhoff normal form theorem, which in turn implies the same bounds on the Sobolev norms. Nevertheless the techniques that we use to prove the existence of quasi-invariant pseudo-norms are much more simple and direct

-Error Estimates of the Extrapolated Crank-Nicolson Discontinuous Galerkin Approximations for Nonlinear Sobolev Equations

Directory of Open Access Journals (Sweden)

Lee HyunYoung

2010-01-01

Full Text Available We analyze discontinuous Galerkin methods with penalty terms, namely, symmetric interior penalty Galerkin methods, to solve nonlinear Sobolev equations. We construct finite element spaces on which we develop fully discrete approximations using extrapolated Crank-Nicolson method. We adopt an appropriate elliptic-type projection, which leads to optimal error estimates of discontinuous Galerkin approximations in both spatial direction and temporal direction.

Vector-valued Lizorkin-Triebel spaces and sharp trace theory for functions in Sobolev spaces with mixed \\pmb{L_p}-norm for parabolic problems

Science.gov (United States)

Weidemaier, P.

2005-06-01

The trace problem on the hypersurface y_n=0 is investigated for a function u=u(y,t) \\in L_q(0,T;W_{\\underline p}^{\\underline m}(\\mathbb R_+^n)) with \\partial_t u \\in L_q(0,T; L_{\\underline p}(\\mathbb R_+^n)), that is, Sobolev spaces with mixed Lebesgue norm L_{\\underline p,q}(\\mathbb R^n_+\\times(0,T))=L_q(0,T;L_{\\underline p}(\\mathbb R_+^n)) are considered; here \\underline p=(p_1,\\dots,p_n) is a vector and \\mathbb R^n_+=\\mathbb R^{n-1} \\times (0,\\infty). Such function spaces are useful in the context of parabolic equations. They allow, in particular, different exponents of summability in space and time. It is shown that the sharp regularity of the trace in the time variable is characterized by the Lizorkin-Triebel space F_{q,p_n}^{1-1/(p_nm_n)}(0,T;L_{\\widetilde{\\underline p}}(\\mathbb R^{n-1})), \\underline p=(\\widetilde{\\underline p},p_n). A similar result is established for first order spatial derivatives of u. These results allow one to determine the exact spaces for the data in the inhomogeneous Dirichlet and Neumann problems for parabolic equations of the second order if the solution is in the space L_q(0,T; W_p^2(\\Omega)) \\cap W_q^1(0,T;L_p(\\Omega)) with p \\le q.

Characterization of generalized Orlicz spaces

KAUST Repository

Ferreira, Rita

2016-12-14

The norm in classical Sobolev spaces can be expressed as a difference quotient. This expression can be used to generalize the space to the fractional smoothness case. Because the difference quotient is based on shifting the function, it cannot be used in generalized Orlicz spaces. In its place, we introduce a smoothed difference quotient and show that it can be used to characterize the generalized Orlicz-Sobolev space. Our results are new even in Orlicz spaces and variable exponent spaces.

Characterization of generalized Orlicz spaces

KAUST Repository

Ferreira, Rita; Hä stö , Peter; Ribeiro, Ana Margarida

2016-01-01

The norm in classical Sobolev spaces can be expressed as a difference quotient. This expression can be used to generalize the space to the fractional smoothness case. Because the difference quotient is based on shifting the function, it cannot be used in generalized Orlicz spaces. In its place, we introduce a smoothed difference quotient and show that it can be used to characterize the generalized Orlicz-Sobolev space. Our results are new even in Orlicz spaces and variable exponent spaces.

Virtual continuity of the measurable functions of several variables, and Sobolev embedding theorems

OpenAIRE

Vershik, Anatoly; Zatitskiy, Pavel; Petrov, Fedor

2013-01-01

Classical Luzin's theorem states that the measurable function of one variable is "almost" continuous. This is not so anymore for functions of several variables. The search of right analogue of the Luzin theorem leads to a notion of virtually continuous functions of several variables. This probably new notion appears implicitly in the statements like embeddings theorems and traces theorems for Sobolev spaces. In fact, it reveals their nature as theorems about virtual continuity. This notion is...

Very weak solutions to the rotating Stokes, Oseen and Navier–Stokes problems in weighted spaces

Czech Academy of Sciences Publication Activity Database

Kračmar, S.; Krbec, Miroslav; Nečasová, Šárka; Penel, P.; Schumacher, K.

2016-01-01

Roč. 289, 11-12 (2016), s. 1466-1487 ISSN 0025-584X R&D Projects: GA ČR GA13-00522S; GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : viscous incompressible fluid * flow around rotating rigid body * very weak solution * weighted homogenous Sobolev spaces Subject RIV: BA - General Mathematics Impact factor: 0.742, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/mana.201400052/abstract?systemMessage=Wiley+Online+Library+will+be+unavailable+on+Saturday+3rd+ September +2016+at+08.30+BST%2F+03%3A30+EDT%2F+15%3A30+SGT+for+5+hours+ and +Sunday+4th+ September +at+10%3A00+BST%2F+05%3A00+EST%2F+17%3A00+SGT+for+1+hour++for+essential+maintenance.+Apologies+for+the+inconvenience

The delta-Sobolev approach for modeling solar spectral irradiance and radiance

International Nuclear Information System (INIS)

Xiang, Xuwu.

1990-01-01

The development and evaluation of a solar radiation model is reported, which gives irradiance and radiance results at the bottom and top of an atmosphere of specified optical depth for each of 145 spectral intervals from 0.29 to 4.05 microns. Absorption by water vapor, aerosols, ozone, and uniformly mixed gases; scattering by molecules and aerosols; and non-Lambertian surface reflectance are included in the model. For solving the radiative transfer equation, an innovative delta-Sobolev method is developed. It applies a delta-function modification to the conventional Sobolev solutions in a way analogous to the delta-Eddington method. The irradiance solution by the delta-Sobolev method turns out to be mathematically identical to the delta-Eddington approximation. The radiance solution by the delta-Sobolov method provides a convenient way to obtain the directional distribution pattern of the radiation transfer field, a feature unable to be obtained by most commonly used approximation methods. Such radiance solutions are also especially useful in models for satellite remote sensing. The model is tested against the rigorous Dave model, which solves the radiation transfer problem by the spherical harmonic method, an accurate but very time consuming process. Good agreement between the current model results and those of Dave's model are observed. The advantages of the delta-Sobolev model are simplicity, reasonable accuracy and capability for implementation on a minicomputer or microcomputer

on differential operators on w 1,2 space and fredholm operators

African Journals Online (AJOL)

A selfadjoint differential operator defined over a closed and bounded interval on Sobolev space which is a dense linear subspace of a Hilbert space over the same interval is considered and shown to be a Fredholm operator with index zero. KEY WORDS: Sobolev space, Hilbert space, dense subspace, Fredholm operator

L2-Error Estimates of the Extrapolated Crank-Nicolson Discontinuous Galerkin Approximations for Nonlinear Sobolev Equations

Directory of Open Access Journals (Sweden)

Hyun Young Lee

2010-01-01

Full Text Available We analyze discontinuous Galerkin methods with penalty terms, namely, symmetric interior penalty Galerkin methods, to solve nonlinear Sobolev equations. We construct finite element spaces on which we develop fully discrete approximations using extrapolated Crank-Nicolson method. We adopt an appropriate elliptic-type projection, which leads to optimal ℓ∞(L2 error estimates of discontinuous Galerkin approximations in both spatial direction and temporal direction.

On the Cauchy problem for a Sobolev-type equation with quadratic non-linearity

International Nuclear Information System (INIS)

Aristov, Anatoly I

2011-01-01

We investigate the asymptotic behaviour as t→∞ of the solution of the Cauchy problem for a Sobolev-type equation with quadratic non-linearity and develop ideas used by I. A. Shishmarev and other authors in the study of classical and Sobolev-type equations. Conditions are found under which it is possible to consider the case of an arbitrary dimension of the spatial variable.

Large-time asymptotic behaviour of solutions of non-linear Sobolev-type equations

International Nuclear Information System (INIS)

Kaikina, Elena I; Naumkin, Pavel I; Shishmarev, Il'ya A

2009-01-01

The large-time asymptotic behaviour of solutions of the Cauchy problem is investigated for a non-linear Sobolev-type equation with dissipation. For small initial data the approach taken is based on a detailed analysis of the Green's function of the linear problem and the use of the contraction mapping method. The case of large initial data is also closely considered. In the supercritical case the asymptotic formulae are quasi-linear. The asymptotic behaviour of solutions of a non-linear Sobolev-type equation with a critical non-linearity of the non-convective kind differs by a logarithmic correction term from the behaviour of solutions of the corresponding linear equation. For a critical convective non-linearity, as well as for a subcritical non-convective non-linearity it is proved that the leading term of the asymptotic expression for large times is a self-similar solution. For Sobolev equations with convective non-linearity the asymptotic behaviour of solutions in the subcritical case is the product of a rarefaction wave and a shock wave. Bibliography: 84 titles.

International Conference on Function Spaces and Inequalities

CERN Document Server

Schmeisser, Hans-Jürgen

2017-01-01

This book features original research and survey articles on the topics of function spaces and inequalities. It focuses on (variable/grand/small) Lebesgue spaces, Orlicz spaces, Lorentz spaces, and Morrey spaces and deals with mapping properties of operators, (weighted) inequalities, pointwise multipliers and interpolation. Moreover, it considers Sobolev–Besov and Triebel–Lizorkin type smoothness spaces. The book includes papers by leading international researchers, presented at the International Conference on Function Spaces and Inequalities, held at the South Asian University, New Delhi, India, on 11–15 December 2015, which focused on recent developments in the theory of spaces with variable exponents. It also offers further investigations concerning Sobolev-type embeddings, discrete inequalities and harmonic analysis. Each chapter is dedicated to a specific topic and written by leading experts, providing an overview of the subject and stimulating future research.

Poisson Stochastic Process and Basic Schauder and Sobolev Estimates in the Theory of Parabolic Equations

Science.gov (United States)

Krylov, N. V.; Priola, E.

2017-09-01

We show, among other things, how knowing Schauder or Sobolev-space estimates for the one-dimensional heat equation allows one to derive their multidimensional analogs for equations with coefficients depending only on the time variable with the same constants as in the case of the one-dimensional heat equation. The method is quite general and is based on using the Poisson stochastic process. It also applies to equations involving non-local operators. It looks like no other methods are available at this time and it is a very challenging problem to find a purely analytical approach to proving such results.

The steady state solutions of radiatively driven stellar winds for a non-Sobolev, pure absorption model

International Nuclear Information System (INIS)

Poe, C.H.; Owocki, S.P.; Castor, J.I.

1990-01-01

The steady state solution topology for absorption line-driven flows is investigated for the condition that the Sobolev approximation is not used to compute the line force. The solution topology near the sonic point is of the nodal type with two positive slope solutions. The shallower of these slopes applies to reasonable lower boundary conditions and realistic ion thermal speed v(th) and to the Sobolev limit of zero of the usual Castor, Abbott, and Klein model. At finite v(th), this solution consists of a family of very similar solutions converging on the sonic point. It is concluded that a non-Sobolev, absorption line-driven flow with a realistic values of v(th) has no uniquely defined steady state. To the extent that a pure absorption model of the outflow of stellar winds is applicable, radiatively driven winds should be intrinsically variable. 34 refs

Stochastic Moyal product on the Wiener space

International Nuclear Information System (INIS)

Dito, Giuseppe; Leandre, Remi

2007-01-01

We propose a stochastic extension of deformation quantization on a Hilbert space. The Moyal product is defined in this context on the space of functionals belonging to all of the Sobolev spaces of the Malliavin calculus

Weighted semiconvex spaces of measurable functions

International Nuclear Information System (INIS)

Olaleru, J.O.

2001-12-01

Semiconvex spaces are intermediates between locally convex spaces and the non locally convex topological vector spaces. They include all locally convex spaces; hence it is a generalization of locally convex spaces. In this article, we make a study of weighted semiconvex spaces parallel to weighted locally convex spaces where continuous functions are replaced with measurable functions and N p family replaces Nachbin family on a locally compact space X. Among others, we examine the Hausdorffness, completeness, inductive limits, barrelledness and countably barrelledness of weighted semiconvex spaces. New results are obtained while we have a more elegant proofs of old results. Furthermore, we get extensions of some of the old results. It is observed that the technique of proving theorems in weighted locally convex spaces can be adapted to that of weighted semicovex spaces of measurable functions in most cases. (author)

Expansion of Sobolev functions in series in Laguerre polynomials

International Nuclear Information System (INIS)

Selyakov, K.I.

1985-01-01

The solution of the integral equation for the Sobolev functions is represented in the form of series in Laguerre polynomials. The coefficients of these series are simultaneously the coefficients of the power series for the Ambartsumyan-Chandrasekhar H functions. Infinite systems of linear algebraic equations with Toeplitz matrices are given for the coefficients of the series. Numerical results and approximate expressions are given for the case of isotropic scattering

Optimality of embeddings of Bessel-potential-type spaces into generalized Hölder spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Neves, J. S.; Opic, Bohumír

2005-01-01

Roč. 49, č. 2 (2005), s. 297-327 ISSN 0214-1493 R&D Projects: GA ČR(CZ) GA201/01/0333 Institutional research plan: CEZ:AV0Z10190503 Keywords : slowly varying functions * Lorentz-Karamata spaces * (fractional) Sobolev-type spaces Subject RIV: BA - General Mathematics Impact factor: 0.659, year: 2005

THE WIGNER–FOKKER–PLANCK EQUATION: STATIONARY STATES AND LARGE TIME BEHAVIOR

KAUST Repository

ARNOLD, ANTON; GAMBA, IRENE M.; GUALDANI, MARIA PIA; MISCHLER, STÉ PHANE; MOUHOT, CLEMENT; SPARBER, CHRISTOF

2012-01-01

solution in a weighted Sobolev space. A key ingredient of the proof is a new result on the existence of spectral gaps for FokkerPlanck type operators in certain weighted L 2-spaces. In addition we show that the steady state corresponds to a positive density

WeightLifter: Visual Weight Space Exploration for Multi-Criteria Decision Making.

Science.gov (United States)

Pajer, Stephan; Streit, Marc; Torsney-Weir, Thomas; Spechtenhauser, Florian; Muller, Torsten; Piringer, Harald

2017-01-01

A common strategy in Multi-Criteria Decision Making (MCDM) is to rank alternative solutions by weighted summary scores. Weights, however, are often abstract to the decision maker and can only be set by vague intuition. While previous work supports a point-wise exploration of weight spaces, we argue that MCDM can benefit from a regional and global visual analysis of weight spaces. Our main contribution is WeightLifter, a novel interactive visualization technique for weight-based MCDM that facilitates the exploration of weight spaces with up to ten criteria. Our technique enables users to better understand the sensitivity of a decision to changes of weights, to efficiently localize weight regions where a given solution ranks high, and to filter out solutions which do not rank high enough for any plausible combination of weights. We provide a comprehensive requirement analysis for weight-based MCDM and describe an interactive workflow that meets these requirements. For evaluation, we describe a usage scenario of WeightLifter in automotive engineering and report qualitative feedback from users of a deployed version as well as preliminary feedback from decision makers in multiple domains. This feedback confirms that WeightLifter increases both the efficiency of weight-based MCDM and the awareness of uncertainty in the ultimate decisions.

The Dirichlet problem with L2-boundary data for elliptic linear equations

CERN Document Server

Chabrowski, Jan

1991-01-01

The Dirichlet problem has a very long history in mathematics and its importance in partial differential equations, harmonic analysis, potential theory and the applied sciences is well-known. In the last decade the Dirichlet problem with L2-boundary data has attracted the attention of several mathematicians. The significant features of this recent research are the use of weighted Sobolev spaces, existence results for elliptic equations under very weak regularity assumptions on coefficients, energy estimates involving L2-norm of a boundary data and the construction of a space larger than the usual Sobolev space W1,2 such that every L2-function on the boundary of a given set is the trace of a suitable element of this space. The book gives a concise account of main aspects of these recent developments and is intended for researchers and graduate students. Some basic knowledge of Sobolev spaces and measure theory is required.

On spaces of functions of smoothness zero

International Nuclear Information System (INIS)

Besov, Oleg V

2012-01-01

The paper is concerned with the new spaces B-bar p,q 0 of functions of smoothness zero defined on the n-dimensional Euclidean space R n or on a subdomain G of R n . These spaces are compared with the spaces B p,q 0 (R n ) and bmo(R n ). The embedding theorems for Sobolev spaces are refined in terms of the space B-bar p,q 0 with the limiting exponent. Bibliography: 8 titles.

Weighted composition operators from Bergman-type spaces into ...

Indian Academy of Sciences (India)

Weighted composition operators from Bergman-type spaces into Bloch spaces and little. Bloch spaces are characterized by function theoretic properties of their inducing maps. Keywords. Weighted composition operator; Bergman-type space; Bloch space. 1. Introduction. Let D be the open unit disk in the complex plane C.

Theory of function spaces

CERN Document Server

Triebel, Hans

1983-01-01

The book deals with the two scales Bsp,q and Fsp,q of spaces of distributions, where -8spaces, such as Hölder spaces, Zygmund classes, Sobolev spaces, Besov spaces, Bessel-potential spaces, Hardy spaces and spaces of BMO-type. It is the main aim of this book to give a unified treatment of the corresponding spaces on the Euclidean n-space Rn in the framework of Fourier analysis, which is based on the technique of maximal functions, Fourier multipliers and interpolation assertions. These topics are treated in Chapter 2, which is the heart

On weighted spaces without a fundamental sequence of bounded sets

International Nuclear Information System (INIS)

Olaleru, J.O.

2001-09-01

The problem of countably quasibarrelledness of weighted spaces of continuous functions, of which there are no results in the general setting of weighted spaces, is tackled in this paper. This leads to the study of quasibarrelledness of weighted spaces which, unlike that of Ernst and Schnettler, though with a similar approach, we drop the assumption that the weighted space has a fundamental sequence of bounded sets. The study of countably quasibarrelledness of weighted spaces naturally leads to definite results on the weighted (DF)-spaces for those weighted spaces with a fundamental sequence of bounded sets. (author)

Integral type operators from normal weighted Bloch spaces to QT,S spaces

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Yongyi GU

2016-08-01

Full Text Available Operator theory is an important research content of the analytic function space theory. The discussion of simultaneous operator and function space is an effective way to study operator and function space. Assuming that  is an analytic self map on the unit disk Δ, and the normal weighted bloch space μ-B is a Banach space on the unit disk Δ, defining a composition operator C∶C(f=f on μ-B for all f∈μ-B, integral type operator JhC and CJh are generalized by integral operator and composition operator. The boundeness and compactness of the integral type operator JhC acting from normal weighted Bloch spaces to QT,S spaces are discussed, as well as the boundeness of the integral type operators CJh acting from normal weighted Bloch spaces to QT,S spaces. The related sufficient and necessary conditions are given.

Characterization of associate spaces of weighted Lorentz spaces with applications

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Pick, L.; Soudský, F.

2014-01-01

Roč. 224, č. 1 (2014), s. 1-23 ISSN 0039-3223 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : weighted Lorentz spaces * weighted inequalities * non-increasing rearragement * Banach function space Subject RIV: BA - General Mathematics Impact factor: 0.610, year: 2014 http://journals.impan.gov.pl/sm/Inf/224-1-1.html

Schur spaces and weighted spaces of type H

African Journals Online (AJOL)

We extend some results related to composition operators on Hv(G) to arbitrary linear operators on Hv0 (G) and Hv(G). We also give examples of rank-one operators on Hv(G) which cannot be approximated by composition operators. Keywords: Weighted Banach spaces of holomorphic functions, Schur spaces, weakly ...

Optimal Embeddings of Bessel-Potential-Type Spaces into Generalized Hölder Spaces Involving k-Modulus of Smoothness

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Neves, J. S.; Opic, Bohumír

2010-01-01

Roč. 32, č. 3 (2010), s. 201-228 ISSN 0926-2601 R&D Projects: GA ČR GA201/05/2033; GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : slowly varying functions * Lorentz-Karamata spaces * Rearrangement-invariant Banach function spaces * Bessel potentials * (fractional) Sobolev-type spaces * Hölder-type spaces * Zygmund-type spaces Subject RIV: BA - General Mathematics Impact factor: 0.853, year: 2010 http://link.springer.com/article/10.1007%2Fs11118-009-9148-2

Weighted Composition Operators from Hardy Spaces into Logarithmic Bloch Spaces

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Flavia Colonna

2012-01-01

Full Text Available The logarithmic Bloch space Blog⁡ is the Banach space of analytic functions on the open unit disk 𝔻 whose elements f satisfy the condition ∥f∥=sup⁡z∈𝔻(1-|z|2log⁡  (2/(1-|z|2|f'(z|<∞. In this work we characterize the bounded and the compact weighted composition operators from the Hardy space Hp (with 1≤p≤∞ into the logarithmic Bloch space. We also provide boundedness and compactness criteria for the weighted composition operator mapping Hp into the little logarithmic Bloch space defined as the subspace of Blog⁡ consisting of the functions f such that lim⁡|z|→1(1-|z|2log⁡  (2/(1-|z|2|f'(z|=0.

Bundles over Quantum RealWeighted Projective Spaces

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Tomasz Brzeziński

2012-09-01

Full Text Available The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1-bundles over quantum real weighted projective spaces are constructed. As the spaces in question fall into two separate classes, the negative or odd class that generalises quantum real projective planes and the positive or even class that generalises the quantum disc, so do the constructed principal bundles. In the negative case the principal bundle is proven to be non-trivial and associated projective modules are described. In the positive case the principal bundles turn out to be trivial, and so all the associated modules are free. It is also shown that the circle (coactions on the quantum Seifert manifold that define quantum real weighted projective spaces are almost free.

On a class of strongly degenerate and singular linear elliptic equation

International Nuclear Information System (INIS)

Duong Minh Duc, D.M.; Le Dung.

1992-11-01

We consider a class of strongly degenerate linear elliptic equation. The boundedness and the Holder regularity of the weak solutions in the weighted Sobolev-Hardy spaces will be studied. (author). 9 refs

Spaces of positive and negative frequency solutions of field equations in curved space--times. I. The Klein--Gordon equation in stationary space--times

International Nuclear Information System (INIS)

Moreno, C.

1977-01-01

In stationary space--times V/sub n/ x R with compact space-section manifold without boundary V/sub n/, the Klein--Gordon equation is solved by the one-parameter group of unitary operators generated by the energy operator i -1 T -1 in the Sobolev spaces H/sup l/(V/sub n/) x H/sup l/(V/sub n/). The canonical symplectic and complex structures of the associated dynamical system are calculated. The existence and the uniqueness of the Lichnerowicz kernel are established. The Hilbert spaces of positive and negative frequency-part solutions defined by means of this kernel are constructed

Weighted Differentiation Composition Operator from Logarithmic Bloch Spaces to Zygmund-Type Spaces

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Huiying Qu

2014-01-01

Full Text Available Let H( denote the space of all holomorphic functions on the unit disk of ℂ, u∈H( and let  n be a positive integer, φ a holomorphic self-map of , and μ a weight. In this paper, we investigate the boundedness and compactness of a weighted differentiation composition operator φ,unf(z=u(zf(n(φ(z,f∈H(, from the logarithmic Bloch spaces to the Zygmund-type spaces.

Existence, uniqueness, and stability of stochastic neutral functional differential equations of Sobolev-type

Energy Technology Data Exchange (ETDEWEB)

Yang, Xuetao; Zhu, Quanxin, E-mail: zqx22@126.com [School of Mathematical Sciences and Institute of Mathematics, Nanjing Normal University, Nanjing 210023, Jiangsu (China)

2015-12-15

In this paper, we are mainly concerned with a class of stochastic neutral functional differential equations of Sobolev-type with Poisson jumps. Under two different sets of conditions, we establish the existence of the mild solution by applying the Leray-Schauder alternative theory and the Sadakovskii’s fixed point theorem, respectively. Furthermore, we use the Bihari’s inequality to prove the Osgood type uniqueness. Also, the mean square exponential stability is investigated by applying the Gronwall inequality. Finally, two examples are given to illustrate the theory results.

Elliptic equations with measure data in Orlicz spaces

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Ge Dong

2008-05-01

Full Text Available This article shows the existence of solutions to the nonlinear elliptic problem $A(u=f$ in Orlicz-Sobolev spaces with a measure valued right-hand side, where $A(u=-mathop{ m div}a(x,u, abla u$ is a Leray-Lions operator defined on a subset of $W_{0}^{1}L_{M}(Omega$, with general $M$.

Weighted local Hardy spaces associated with operators

Indian Academy of Sciences (India)

RUMING GONG

2018-04-24

5 days ago ... Studies 116 (1985) (Amsterdam: North Holland). [12] Gong R M and Yan L X, Littlewood–Paley and spectral multipliers on weighted L p spaces, J. Geom. Anal. 24 (2014) 873–900. [13] Gong R M, Li J and Yan L X, A local version of Hardy spaces associated with operators on metric spaces, Sci. China Math.

Trigonometric bases for matrix weighted Lp-spaces

DEFF Research Database (Denmark)

Nielsen, Morten

2010-01-01

We give a complete characterization of 2π-periodic matrix weights W for which the vector-valued trigonometric system forms a Schauder basis for the matrix weighted space Lp(T;W). Then trigonometric quasi-greedy bases for Lp(T;W) are considered. Quasi-greedy bases are systems for which the simple...

Hörmander spaces, interpolation, and elliptic problems

CERN Document Server

Mikhailets, Vladimir A; Malyshev, Peter V

2014-01-01

The monograph gives a detailed exposition of the theory of general elliptic operators (scalar and matrix) and elliptic boundary value problems in Hilbert scales of Hörmander function spaces. This theory was constructed by the authors in a number of papers published in 2005-2009. It is distinguished by a systematic use of the method of interpolation with a functional parameter of abstract Hilbert spaces and Sobolev inner product spaces. This method, the theory and their applications are expounded for the first time in the monographic literature. The monograph is written in detail and in a

Second order elastic metrics on the shape space of curves

DEFF Research Database (Denmark)

Bauer, Martin; Bruveris, Martins; Harms, Philipp

2015-01-01

Second order Sobolev metrics on the space of regular unparametrized planar curves have several desirable completeness properties not present in lower order metrics, but numerics are still largely missing. In this paper, we present algorithms to numerically solve the initial and boundary value......, due to its generality, it could be applied to more general spaces of mapping. We demonstrate the effectiveness of our approach by analyzing a collection of shapes representing physical objects....

Approximate Solution of Nonlinear Klein-Gordon Equation Using Sobolev Gradients

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Nauman Raza

2016-01-01

Full Text Available The nonlinear Klein-Gordon equation (KGE models many nonlinear phenomena. In this paper, we propose a scheme for numerical approximation of solutions of the one-dimensional nonlinear KGE. A common approach to find a solution of a nonlinear system is to first linearize the equations by successive substitution or the Newton iteration method and then solve a linear least squares problem. Here, we show that it can be advantageous to form a sum of squared residuals of the nonlinear problem and then find a zero of the gradient. Our scheme is based on the Sobolev gradient method for solving a nonlinear least square problem directly. The numerical results are compared with Lattice Boltzmann Method (LBM. The L2, L∞, and Root-Mean-Square (RMS values indicate better accuracy of the proposed method with less computational effort.

Spectral multipliers on spaces of distributions associated with non-negative self-adjoint operators

DEFF Research Database (Denmark)

Georgiadis, Athanasios; Nielsen, Morten

2018-01-01

and Triebel–Lizorkin spaces with full range of indices is established too. As an application, we obtain equivalent norm characterizations for the spaces mentioned above. Non-classical spaces as well as Lebesgue, Hardy, (generalized) Sobolev and Lipschitz spaces are also covered by our approach.......We consider spaces of homogeneous type associated with a non-negative self-adjoint operator whose heat kernel satisfies certain upper Gaussian bounds. Spectral multipliers are introduced and studied on distributions associated with this operator. The boundedness of spectral multipliers on Besov...

Characterization of associate spaces of generalized weighted weak-Lorentz spaces and embeddings

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Aykol, C.; Guliyev, V.S.

2015-01-01

Roč. 228, č. 3 (2015), s. 223-233 ISSN 0039-3223 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : generalized weighted weak-Lorentz spaces * reverse Hardy inequalities * associate spaces * embeddings Subject RIV: BA - General Mathematics Impact factor: 0.623, year: 2015 http://journals.impan.gov.pl/sm/Inf/228-3-2.html

Unbounded weighted composition operators in L²-spaces

CERN Document Server

Budzyński, Piotr; Jung, Il Bong; Stochel, Jan

2018-01-01

This book establishes the foundations of the theory of bounded and unbounded weighted composition operators in L²-spaces. It develops the theory in full generality, meaning that the weighted composition operators under consideration are not regarded as products of multiplication and composition operators. A variety of seminormality properties are characterized and the first-ever criteria for subnormality of unbounded weighted composition operators is provided. The subtle interplay between the classical moment problem, graph theory and the injectivity problem is revealed and there is an investigation of the relationships between weighted composition operators and the corresponding multiplication and composition operators. The optimality of the obtained results is illustrated by a variety of examples, including those of discrete and continuous types. The book is primarily aimed at researchers in single or multivariable operator theory.

Mitigating nonlinearity in full waveform inversion using scaled-Sobolev pre-conditioning

Science.gov (United States)

Zuberi, M. AH; Pratt, R. G.

2018-04-01

The Born approximation successfully linearizes seismic full waveform inversion if the background velocity is sufficiently accurate. When the background velocity is not known it can be estimated by using model scale separation methods. A frequently used technique is to separate the spatial scales of the model according to the scattering angles present in the data, by using either first- or second-order terms in the Born series. For example, the well-known `banana-donut' and the `rabbit ear' shaped kernels are, respectively, the first- and second-order Born terms in which at least one of the scattering events is associated with a large angle. Whichever term of the Born series is used, all such methods suffer from errors in the starting velocity model because all terms in the Born series assume that the background Green's function is known. An alternative approach to Born-based scale separation is to work in the model domain, for example, by Gaussian smoothing of the update vectors, or some other approach for separation by model wavenumbers. However such model domain methods are usually based on a strict separation in which only the low-wavenumber updates are retained. This implies that the scattered information in the data is not taken into account. This can lead to the inversion being trapped in a false (local) minimum when sharp features are updated incorrectly. In this study we propose a scaled-Sobolev pre-conditioning (SSP) of the updates to achieve a constrained scale separation in the model domain. The SSP is obtained by introducing a scaled Sobolev inner product (SSIP) into the measure of the gradient of the objective function with respect to the model parameters. This modified measure seeks reductions in the L2 norm of the spatial derivatives of the gradient without changing the objective function. The SSP does not rely on the Born prediction of scale based on scattering angles, and requires negligible extra computational cost per iteration. Synthetic

Weighted inequalities for fractional integral operators and linear commutators in the Morrey-type spaces

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Hua Wang

2017-01-01

Full Text Available Abstract In this paper, we first introduce some new Morrey-type spaces containing generalized Morrey space and weighted Morrey space with two weights as special cases. Then we give the weighted strong type and weak type estimates for fractional integral operators I α $I_{\\alpha}$ in these new Morrey-type spaces. Furthermore, the weighted strong type estimate and endpoint estimate of linear commutators [ b , I α ] $[b,I_{\\alpha}]$ formed by b and I α $I_{\\alpha}$ are established. Also we study related problems about two-weight, weak type inequalities for I α $I_{\\alpha}$ and [ b , I α ] $[b,I_{\\alpha}]$ in the Morrey-type spaces and give partial results.

Y spaces and global smooth solution of fractional Navier-Stokes equations with initial value in the critical oscillation spaces

Science.gov (United States)

Yang, Qixiang; Yang, Haibo

2018-04-01

For fractional Navier-Stokes equations and critical initial spaces X, one used to establish the well-posedness in the solution space which is contained in C (R+ , X). In this paper, for heat flow, we apply parameter Meyer wavelets to introduce Y spaces Y m , β where Y m , β is not contained in C (R+, B˙∞ 1 - 2 β , ∞). Consequently, for 1/2 global well-posedness of fractional Navier-Stokes equations with small initial data in all the critical oscillation spaces. The critical oscillation spaces may be any Besov-Morrey spaces (B˙p,q γ1 ,γ2 (Rn)) n or any Triebel-Lizorkin-Morrey spaces (F˙p,q γ1 ,γ2 (Rn)) n where 1 ≤ p , q ≤ ∞ , 0 ≤γ2 ≤ n/p, γ1 -γ2 = 1 - 2 β. These critical spaces include many known spaces. For example, Besov spaces, Sobolev spaces, Bloch spaces, Q-spaces, Morrey spaces and Triebel-Lizorkin spaces etc.

Nonclassical Problem for Ultraparabolic Equation in Abstract Spaces

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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.

Spectral analysis of difference and differential operators in weighted spaces

International Nuclear Information System (INIS)

Bichegkuev, M S

2013-01-01

This paper is concerned with describing the spectrum of the difference operator K:l α p (Z,X)→l α p (Z......athscrKx)(n)=Bx(n−1),  n∈Z,  x∈l α p (Z,X), with a constant operator coefficient B, which is a bounded linear operator in a Banach space X. It is assumed that K acts in the weighted space l α p (Z,X), 1≤p≤∞, of two-sided sequences of vectors from X. The main results are obtained in terms of the spectrum σ(B) of the operator coefficient B and properties of the weight function. Applications to the study of the spectrum of a differential operator with an unbounded operator coefficient (the generator of a strongly continuous semigroup of operators) in weighted function spaces are given. Bibliography: 23 titles

An improvement of dimension-free Sobolev imbeddings in r spaces

Czech Academy of Sciences Publication Activity Database

Fiorenza, A.; Krbec, Miroslav; Schmeisser, H.-J.

2014-01-01

Roč. 267, č. 1 (2014), s. 243-261 ISSN 0022-1236 R&D Projects: GA ČR GAP201/10/1920 Institutional support: RVO:67985840 Keywords : imbedding theorem * small Lebesgue space * rearrangement-invariant Banach Subject RIV: BA - General Mathematics Impact factor: 1.322, year: 2014 http://www.sciencedirect.com/science/article/pii/S0022123614001724

Superconformal compactifications in weighted projective space

International Nuclear Information System (INIS)

Greene, B.R.

1990-01-01

We discuss some aspects of string vacua constructed from orbifolded nonminimal Landau-Ginzburg theories which correspond to Calabi-Yau manifolds in weighted projective space. In contrast to previous expectations, we find that these theories allow for the construction of numerous stable (2, 0) Calabi-Yau vacua (most of which are not simply deformations of an underlying (2, 2) theory) thus indicating that this phenomenologically promising sector of the space of classical vacua is quite robust. We briefly discuss methods for extracting the phenomenology of these models and show, for example, that the full renormalizable superpotential of our SU(5) theories is not corrected by world sheet instantons and is thus given exactly by its tree-level value. (orig.)

Spacelike Hypersurfaces in Weighted Generalized Robertson-Walker Space-Times

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Ximin Liu

2018-01-01

Full Text Available Applying generalized maximum principle and weak maximum principle, we obtain several uniqueness results for spacelike hypersurfaces immersed in a weighted generalized Robertson-Walker (GRW space-time under suitable geometric assumptions. Furthermore, we also study the special case when the ambient space is static and provide some results by using Bochner’s formula.

Approximation of Müntz-Szász type in weighted spaces

Energy Technology Data Exchange (ETDEWEB)

Sedletskii, A M [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

2013-07-31

The paper looks at whether a system of exponentials exp(-λ{sub n}t), Reλ{sub n}>0, is complete in various function spaces on the half-line R{sub +}. Wide classes of Banach spaces E and F of functions on R{sub +} are described such that this system is complete in E and F simultaneously. A test is established to determine when this system is complete in the weighted spaces C{sub 0} and L{sup p} with weight (1+t){sup α} on R{sub +}, for α<0 and α<-1, respectively. Bibliography: 18 titles.

On the differential structure of metric measure spaces and applications

CERN Document Server

Gigli, Nicola

2015-01-01

The main goals of this paper are: (i) To develop an abstract differential calculus on metric measure spaces by investigating the duality relations between differentials and gradients of Sobolev functions. This will be achieved without calling into play any sort of analysis in charts, our assumptions being: the metric space is complete and separable and the measure is Radon and non-negative. (ii) To employ these notions of calculus to provide, via integration by parts, a general definition of distributional Laplacian, thus giving a meaning to an expression like \\Delta g=\\mu, where g is a functi

On the Projective Description of Weighted (LF-Spaces of Continuous Functions

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Catherine V. Komarchuk

2014-01-01

Full Text Available We solve the problem of the topological or algebraic description of countable inductive limits of weighted Fréchet spaces of continuous functions on a cone. This problem is investigated for two families of weights defined by positively homogeneous functions. Weights of this form play the important role in Fourier analysis.

Classical and Weak Solutions for Two Models in Mathematical Finance

Science.gov (United States)

Gyulov, Tihomir B.; Valkov, Radoslav L.

2011-12-01

We study two mathematical models, arising in financial mathematics. These models are one-dimensional analogues of the famous Black-Scholes equation on finite interval. The main difficulty is the degeneration at the both ends of the space interval. First, classical solutions are studied. Positivity and convexity properties of the solutions are discussed. Variational formulation in weighted Sobolev spaces is introduced and existence and uniqueness of the weak solution is proved. Maximum principle for weak solution is discussed.

Solvability of Urysohn and Urysohn-Volterra equations with hysteresis in weighted spaces

International Nuclear Information System (INIS)

Darwish Mohamed Abdalla

2005-09-01

The existence of solutions to nonlinear integral equations of the second kind with hysteresis, of Urysohn-Volterra and Urysohn types has been established. We develop the solvability theory of Urysohn-Volterra equation with hysteresis in weighted spaces proposed by the author [M.A. Darwish, On solvability of Urysohn-Volterra equations with hysteresis in weighted spaces, J. Integral Equations and Application, 14(2) (2002), 151-163]. (author)

THE WIGNER–FOKKER–PLANCK EQUATION: STATIONARY STATES AND LARGE TIME BEHAVIOR

KAUST Repository

ARNOLD, ANTON

2012-11-01

We consider the linear WignerFokkerPlanck equation subject to confining potentials which are smooth perturbations of the harmonic oscillator potential. For a certain class of perturbations we prove that the equation admits a unique stationary solution in a weighted Sobolev space. A key ingredient of the proof is a new result on the existence of spectral gaps for FokkerPlanck type operators in certain weighted L 2-spaces. In addition we show that the steady state corresponds to a positive density matrix operator with unit trace and that the solutions of the time-dependent problem converge towards the steady state with an exponential rate. © 2012 World Scientific Publishing Company.

The Multivariate Müntz-Szasz Problem in Weighted Banach Space on Rn

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Xiangdong Yang

2014-01-01

Full Text Available The purpose of this paper is to give an extension of Müntz-Szasz theorems to multivariable weighted Banach space. Denote by {λk=(λk1,λk2,...,λkn}k=1∞ a sequence of real numbers in R+n. The completeness of monomials {tλk} in Cα is investigated, where Cα is the weighted Banach spaces which consist of complex continuous functions f defined on Rn with f(t exp(-α(t vanishing at infinity in the uniform norm.

Embeddings of Sobolev-type spaces into generalized Hölder spaces involving k-modulus of smoothness

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Moura, S.; Neves, J. S.; Opic, B.

2015-01-01

Roč. 194, č. 2 (2015), s. 425-450 ISSN 0373-3114 R&D Projects: GA ČR GA13-14743S; GA ČR GA201/08/0383 Institutional support: RVO:67985840 Keywords : rearrangement-invariant Banach function space * modulus of smoothness * distributional gradient Subject RIV: BA - General Mathematics Impact factor: 0.861, year: 2015 http://link.springer.com/article/10.1007/s10231-013-0383-1

A negative-norm least-squares method for time-harmonic Maxwell equations

KAUST Repository

Copeland, Dylan M.

2012-04-01

This paper presents and analyzes a negative-norm least-squares finite element discretization method for the dimension-reduced time-harmonic Maxwell equations in the case of axial symmetry. The reduced equations are expressed in cylindrical coordinates, and the analysis consequently involves weighted Sobolev spaces based on the degenerate radial weighting. The main theoretical results established in this work include existence and uniqueness of the continuous and discrete formulations and error estimates for simple finite element functions. Numerical experiments confirm the error estimates and efficiency of the method for piecewise constant coefficients. © 2011 Elsevier Inc.

Stabilization of exact nonlinear Timoshenko beams in space by boundary feedback

Science.gov (United States)

Do, K. D.

2018-05-01

Boundary feedback controllers are designed to stabilize Timoshenko beams with large translational and rotational motions in space under external disturbances. The exact nonlinear partial differential equations governing motion of the beams are derived and used in the control design. The designed controllers guarantee globally practically asymptotically (and locally practically exponentially) stability of the beam motions at the reference state. The control design, well-posedness and stability analysis are based on various relationships between the earth-fixed and body-fixed coordinates, Sobolev embeddings, and a Lyapunov-type theorem developed to study well-posedness and stability for a class of evolution systems in Hilbert space. Simulation results are included to illustrate the effectiveness of the proposed control design.

Dissatisfaction of Compact Picard Condition (CPC) with GRACE satellite data and its treatment by Generalized Tikhonov in Sobolev subspace

Science.gov (United States)

AllahTavakoli, Y.; Bagheri, H.; Safari, A.; Sharifi, M.

2012-04-01

This paper is mainly aiming to prove that the stripy noises in the map of earth's surface mass-density changes derived from GRACE Satellites gravimetry, is due to a dissatisfaction of Compact Picard Condition (CPC) with the GRACE data in the inversion of the Newton Integral Equation over the thin layer of earth; and hence the paper proposes the regularization strategies as efficient tools to treat the Ill-posedness and consequently to de-strip the data. First of all, we preferred to slightly modify the mathematical model of earth's surface mass-density changes developed creatively first by J. Wahr and et.al (1998), according to the all their previous assumptions plus taking into consideration the effect of the earth topography. By the modification we expect that some uncertainties in the prior model have been reduced to some extent. Then we analyzed the CPC on the model and we demonstrated how to perform Generalized Tikhonov regularization in Sobolev subspace for overcoming the instability of the problem. Then we applied the strategy in some simulations and case studies to validate our ideas. The simulations confirm that the stripy noises in the GRACE-derived map of the mass-density changes are due to the CPC dissatisfaction and furthermore the case studies show that Generalized Tikhonov regularization in Sobolev subspace is an influential filtering tool to de-strip the noisy data. Also, the case studies interestingly show that the effect of the topography is comparable to the effect of the load Love numbers on the Wahr's model; hence it may be taken into consideration when the load Love numbers have been taken into account.

Revisiting Robustness and Evolvability: Evolution in Weighted Genotype Spaces

Science.gov (United States)

Partha, Raghavendran; Raman, Karthik

2014-01-01

Robustness and evolvability are highly intertwined properties of biological systems. The relationship between these properties determines how biological systems are able to withstand mutations and show variation in response to them. Computational studies have explored the relationship between these two properties using neutral networks of RNA sequences (genotype) and their secondary structures (phenotype) as a model system. However, these studies have assumed every mutation to a sequence to be equally likely; the differences in the likelihood of the occurrence of various mutations, and the consequence of probabilistic nature of the mutations in such a system have previously been ignored. Associating probabilities to mutations essentially results in the weighting of genotype space. We here perform a comparative analysis of weighted and unweighted neutral networks of RNA sequences, and subsequently explore the relationship between robustness and evolvability. We show that assuming an equal likelihood for all mutations (as in an unweighted network), underestimates robustness and overestimates evolvability of a system. In spite of discarding this assumption, we observe that a negative correlation between sequence (genotype) robustness and sequence evolvability persists, and also that structure (phenotype) robustness promotes structure evolvability, as observed in earlier studies using unweighted networks. We also study the effects of base composition bias on robustness and evolvability. Particularly, we explore the association between robustness and evolvability in a sequence space that is AU-rich – sequences with an AU content of 80% or higher, compared to a normal (unbiased) sequence space. We find that evolvability of both sequences and structures in an AU-rich space is lesser compared to the normal space, and robustness higher. We also observe that AU-rich populations evolving on neutral networks of phenotypes, can access less phenotypic variation compared to

Interpolation functors and interpolation spaces

CERN Document Server

Brudnyi, Yu A

1991-01-01

The theory of interpolation spaces has its origin in the classical work of Riesz and Marcinkiewicz but had its first flowering in the years around 1960 with the pioneering work of Aronszajn, Calderón, Gagliardo, Krein, Lions and a few others. It is interesting to note that what originally triggered off this avalanche were concrete problems in the theory of elliptic boundary value problems related to the scale of Sobolev spaces. Later on, applications were found in many other areas of mathematics: harmonic analysis, approximation theory, theoretical numerical analysis, geometry of Banach spaces, nonlinear functional analysis, etc. Besides this the theory has a considerable internal beauty and must by now be regarded as an independent branch of analysis, with its own problems and methods. Further development in the 1970s and 1980s included the solution by the authors of this book of one of the outstanding questions in the theory of the real method, the K-divisibility problem. In a way, this book harvests the r...

Global Well-Posedness of the Incompressible Magnetohydrodynamics

Science.gov (United States)

Cai, Yuan; Lei, Zhen

2018-06-01

This paper studies the Cauchy problem of the incompressible magnetohydro dynamic systems with or without viscosity ν. Under the assumption that the initial velocity field and the displacement of the initialmagnetic field froma non-zero constant are sufficiently small in certain weighted Sobolev spaces, the Cauchy problem is shown to be globally well-posed for all ν ≧ 0 and all spaces with dimension n ≧ 2. Such a result holds true uniformly in nonnegative viscosity parameters. The proof is based on the inherent strong null structure of the systems introduced by Lei (Commun Pure Appl Math 69(11):2072-2106, 2016) and the ghost weight technique introduced by Alinhac (Invent Math 145(3):597-618, 2001).

On a Mixed Nonlinear One Point Boundary Value Problem for an Integrodifferential Equation

Directory of Open Access Journals (Sweden)

Mesloub Said

2008-01-01

Full Text Available This paper is devoted to the study of a mixed problem for a nonlinear parabolic integro-differential equation which mainly arise from a one dimensional quasistatic contact problem. We prove the existence and uniqueness of solutions in a weighted Sobolev space. Proofs are based on some a priori estimates and on the Schauder fixed point theorem. we also give a result which helps to establish the regularity of a solution.

Existence and exponential stability of traveling waves for delayed reaction-diffusion systems

Science.gov (United States)

Hsu, Cheng-Hsiung; Yang, Tzi-Sheng; Yu, Zhixian

2018-03-01

The purpose of this work is to investigate the existence and exponential stability of traveling wave solutions for general delayed multi-component reaction-diffusion systems. Following the monotone iteration scheme via an explicit construction of a pair of upper and lower solutions, we first obtain the existence of monostable traveling wave solutions connecting two different equilibria. Then, applying the techniques of weighted energy method and comparison principle, we show that all solutions of the Cauchy problem for the considered systems converge exponentially to traveling wave solutions provided that the initial perturbations around the traveling wave fronts belong to a suitable weighted Sobolev space.

Eigenvalue problems for degenerate nonlinear elliptic equations in anisotropic media

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Vicenţiu RăDulescu

2005-06-01

Full Text Available We study nonlinear eigenvalue problems of the type −div(a(x∇u=g(λ,x,u in ℝN, where a(x is a degenerate nonnegative weight. We establish the existence of solutions and we obtain information on qualitative properties as multiplicity and location of solutions. Our approach is based on the critical point theory in Sobolev weighted spaces combined with a Caffarelli-Kohn-Nirenberg-type inequality. A specific minimax method is developed without making use of Palais-Smale condition.

Functional inequalities

CERN Document Server

Ghoussoub, Nassif

2013-01-01

The book describes how functional inequalities are often manifestations of natural mathematical structures and physical phenomena, and how a few general principles validate large classes of analytic/geometric inequalities, old and new. This point of view leads to "systematic" approaches for proving the most basic inequalities, but also for improving them, and for devising new ones--sometimes at will and often on demand. These general principles also offer novel ways for estimating best constants and for deciding whether these are attained in appropriate function spaces. As such, improvements of Hardy and Hardy-Rellich type inequalities involving radially symmetric weights are variational manifestations of Sturm's theory on the oscillatory behavior of certain ordinary differential equations. On the other hand, most geometric inequalities, including those of Sobolev and Log-Sobolev type, are simply expressions of the convexity of certain free energy functionals along the geodesics on the Wasserstein manifold of...

Shape tracking with occlusions via coarse-to-fine region-based sobolev descent

KAUST Repository

Yang, Yanchao

2015-05-01

We present a method to track the shape of an object from video. The method uses a joint shape and appearance model of the object, which is propagated to match shape and radiance in subsequent frames, determining object shape. Self-occlusions and dis-occlusions of the object from camera and object motion pose difficulties to joint shape and appearance models in tracking. They are unable to adapt to new shape and appearance information, leading to inaccurate shape detection. In this work, we model self-occlusions and dis-occlusions in a joint shape and appearance tracking framework. Self-occlusions and the warp to propagate the model are coupled, thus we formulate a joint optimization problem. We derive a coarse-to-fine optimization method, advantageous in tracking, that initially perturbs the model by coarse perturbations before transitioning to finer-scale perturbations seamlessly. This coarse-to-fine behavior is automatically induced by gradient descent on a novel infinite-dimensional Riemannian manifold that we introduce. The manifold consists of planar parameterized regions, and the metric that we introduce is a novel Sobolev metric. Experiments on video exhibiting occlusions/dis-occlusions, complex radiance and background show that occlusion/dis-occlusion modeling leads to superior shape accuracy. © 2014 IEEE.

On the ill-posedness of the Gardner equation

DEFF Research Database (Denmark)

Alejo Plana, Miguel Angel

2012-01-01

We present ill-posedness results for the initial value problem (IVP) for the Gardner equation. We measure the regularity of the Cauchy problem in the classical Sobolev spaces Hs, and show the critical Sobolev index under which the local well-posedness of the problem is not present, in the sense t...

The characterization of weighted local hardy spaces on domains and its application.

Science.gov (United States)

Wang, Heng-geng; Yang, Xiao-ming

2004-09-01

In this paper, we give the four equivalent characterizations for the weighted local hardy spaces on Lipschitz domains. Also, we give their application for the harmonic function defined in bounded Lipschitz domains.

Weighted Traffic Equilibrium Problem in Non Pivot Hilbert Spaces with Long Term Memory

International Nuclear Information System (INIS)

Giuffre, Sofia; Pia, Stephane

2010-01-01

In the paper we consider a weighted traffic equilibrium problem in a non-pivot Hilbert space and prove the equivalence between a weighted Wardrop condition and a variational inequality with long term memory. As an application we show, using recent results of the Senseable Laboratory at MIT, how wireless devices can be used to optimize the traffic equilibrium problem.

A Novel Transfer Learning Method Based on Common Space Mapping and Weighted Domain Matching

KAUST Repository

Liang, Ru-Ze; Xie, Wei; Li, Weizhi; Wang, Hongqi; Wang, Jim Jing-Yan; Taylor, Lisa

2017-01-01

In this paper, we propose a novel learning framework for the problem of domain transfer learning. We map the data of two domains to one single common space, and learn a classifier in this common space. Then we adapt the common classifier to the two domains by adding two adaptive functions to it respectively. In the common space, the target domain data points are weighted and matched to the target domain in term of distributions. The weighting terms of source domain data points and the target domain classification responses are also regularized by the local reconstruction coefficients. The novel transfer learning framework is evaluated over some benchmark cross-domain data sets, and it outperforms the existing state-of-the-art transfer learning methods.

A Novel Transfer Learning Method Based on Common Space Mapping and Weighted Domain Matching

KAUST Repository

Liang, Ru-Ze

2017-01-17

In this paper, we propose a novel learning framework for the problem of domain transfer learning. We map the data of two domains to one single common space, and learn a classifier in this common space. Then we adapt the common classifier to the two domains by adding two adaptive functions to it respectively. In the common space, the target domain data points are weighted and matched to the target domain in term of distributions. The weighting terms of source domain data points and the target domain classification responses are also regularized by the local reconstruction coefficients. The novel transfer learning framework is evaluated over some benchmark cross-domain data sets, and it outperforms the existing state-of-the-art transfer learning methods.

Differential operators on Hermite Sobolev spaces

Indian Academy of Sciences (India)

Unit, Indian Statistical Institute, Bangalore 560 059, India. ∗Corresponding Author ... Mathematics Subject Classification. Primary: 60H15; Secondary: ... Some applications of this will be developed in a separate article. We prove our results.

Integration Processes of Delay Differential Equation Based on Modified Laguerre Functions

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Yeguo Sun

2012-01-01

Full Text Available We propose long-time convergent numerical integration processes for delay differential equations. We first construct an integration process based on modified Laguerre functions. Then we establish its global convergence in certain weighted Sobolev space. The proposed numerical integration processes can also be used for systems of delay differential equations. We also developed a technique for refinement of modified Laguerre-Radau interpolations. Lastly, numerical results demonstrate the spectral accuracy of the proposed method and coincide well with analysis.

The C*-algebras of quantum lens and weighted projective spaces

DEFF Research Database (Denmark)

Brzezinski, Tomasz; Szymanski, Wojciech

2018-01-01

It is shown that the algebra of continuous functions on the quantum 2n+1-dimensional lens space C(L^{2n+1}_q(N; m_0,..., m_n)) is a graph C*-algebra, for arbitrary positive weights m_0,..., m_n. The form of the corresponding graph is determined from the skew product of the graph which defines the...

Weight and cost forecasting for advanced manned space vehicles

Science.gov (United States)

Williams, Raymond

1989-01-01

A mass and cost estimating computerized methology for predicting advanced manned space vehicle weights and costs was developed. The user friendly methology designated MERCER (Mass Estimating Relationship/Cost Estimating Relationship) organizes the predictive process according to major vehicle subsystem levels. Design, development, test, evaluation, and flight hardware cost forecasting is treated by the study. This methodology consists of a complete set of mass estimating relationships (MERs) which serve as the control components for the model and cost estimating relationships (CERs) which use MER output as input. To develop this model, numerous MER and CER studies were surveyed and modified where required. Additionally, relationships were regressed from raw data to accommodate the methology. The models and formulations which estimated the cost of historical vehicles to within 20 percent of the actual cost were selected. The result of the research, along with components of the MERCER Program, are reported. On the basis of the analysis, the following conclusions were established: (1) The cost of a spacecraft is best estimated by summing the cost of individual subsystems; (2) No one cost equation can be used for forecasting the cost of all spacecraft; (3) Spacecraft cost is highly correlated with its mass; (4) No study surveyed contained sufficient formulations to autonomously forecast the cost and weight of the entire advanced manned vehicle spacecraft program; (5) No user friendly program was found that linked MERs with CERs to produce spacecraft cost; and (6) The group accumulation weight estimation method (summing the estimated weights of the various subsystems) proved to be a useful method for finding total weight and cost of a spacecraft.

Irreducible quantum group modules with finite dimensional weight spaces

DEFF Research Database (Denmark)

Pedersen, Dennis Hasselstrøm

a finitely generated U q -module which has finite dimensional weight spaces and is a sum of those. Our approach follows the procedures used by S. Fernando and O. Mathieu to solve the corresponding problem for semisimple complex Lie algebra modules. To achieve this we have to overcome a number of obstacles...... not present in the classical case. In the process we also construct twisting functors rigerously for quantum group modules, study twisted Verma modules and show that these admit a Jantzen filtration with corresponding Jantzen sum formula....

Heat conduction problem of an evaporating liquid wedge

Directory of Open Access Journals (Sweden)

Tomas Barta

2015-02-01

Full Text Available We consider the stationary heat transfer near the contact line of an evaporating liquid wedge surrounded by the atmosphere of its pure vapor. In a simplified setting, the problem reduces to the Laplace equation in a half circle, subject to a non-homogeneous and singular boundary condition. By classical tools (conformal mapping, Green's function, we reformulate the problem as an integral equation for the unknown Neumann boundary condition in the setting of appropriate fractional Sobolev and weighted space. The unique solvability is then obtained by means of the Fredholm theorem.

The Orthodox Doctrine of Salvation» by Archimandrite Sergius (Stragorodsky and its criticism by Confessor of the Faith Victor (Ostrovidov and Archbishop Seraphim (Sobolev

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P. KHONDSINSKIY

2014-04-01

Full Text Available «The Orthodox Doctrine of Salvation», a well-known work by Archimandrite Sergius (Stragorodsky that was defended by him as a master’s thesis at the Moscow Theological Academy in 1895, is still considered an etalon in Orthodox theology. Meanwhile, in the first half of the 20th century, it was heavily criticized by at least two prominent members of the Church hierarchy of that time: Confessor of the Faith Victor (Ostrovidov and Archbishop Seraphim (Sobolev. This article does not only examine their arguments, but also provides the researcher’s personal understanding of the main theses of the work by Archimandrite Sergius. The researcher’s work in this case is complicated by a large number of patristic texts, which are given by Archimandrite Sergius and the abundance of which hampers the identification of his own original ideas. Nevertheless, the carried out analysis reveals that the dissertation doesn’t contain not only patristic, but any kind of a clear doctrine of the Fall, or of man’s state after the Fall, or of redemption, or of man’s assimilation of redemption fruits. Besides, the theses illustrated in the dissertation by the texts of the Holy Fathers belong not so much to them as to the first Slavophiles, Archimandrite Anthony (Khrapovitsky, the teacher and the senior friend of Archimandrite Sergius, and finally to Immanuel Kant. Consequently, in his doctrine of freedom anticipating grace, Archimandrite Sergius comes dangerously close to Pelagianism. These findings recognize the truth of complaints against the work of Archimandrite Sergius by Confessor of the Faith Viktor (Ostrovidov and Archbishop Seraphim (Sobolev.

Configuration space analysis of common cost functions in radiotherapy beam-weight optimization algorithms

Energy Technology Data Exchange (ETDEWEB)

Rowbottom, Carl Graham [Joint Department of Physics, Institute of Cancer Research and the Royal Marsden NHS Trust, Sutton, Surrey (United Kingdom); Webb, Steve [Joint Department of Physics, Institute of Cancer Research and the Royal Marsden NHS Trust, Sutton, Surrey (United Kingdom)

2002-01-07

The successful implementation of downhill search engines in radiotherapy optimization algorithms depends on the absence of local minima in the search space. Such techniques are much faster than stochastic optimization methods but may become trapped in local minima if they exist. A technique known as 'configuration space analysis' was applied to examine the search space of cost functions used in radiotherapy beam-weight optimization algorithms. A downhill-simplex beam-weight optimization algorithm was run repeatedly to produce a frequency distribution of final cost values. By plotting the frequency distribution as a function of final cost, the existence of local minima can be determined. Common cost functions such as the quadratic deviation of dose to the planning target volume (PTV), integral dose to organs-at-risk (OARs), dose-threshold and dose-volume constraints for OARs were studied. Combinations of the cost functions were also considered. The simple cost function terms such as the quadratic PTV dose and integral dose to OAR cost function terms are not susceptible to local minima. In contrast, dose-threshold and dose-volume OAR constraint cost function terms are able to produce local minima in the example case studied. (author)

Quantitative Hahn-Banach Theorems and Isometric Extensions forWavelet and Other Banach Spaces

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Sergey Ajiev

2013-05-01

Full Text Available We introduce and study Clarkson, Dol’nikov-Pichugov, Jacobi and mutual diameter constants reflecting the geometry of a Banach space and Clarkson, Jacobi and Pichugov classes of Banach spaces and their relations with James, self-Jung, Kottman and Schäffer constants in order to establish quantitative versions of Hahn-Banach separability theorem and to characterise the isometric extendability of Hölder-Lipschitz mappings. Abstract results are further applied to the spaces and pairs from the wide classes IG and IG+ and non-commutative Lp-spaces. The intimate relation between the subspaces and quotients of the IG-spaces on one side and various types of anisotropic Besov, Lizorkin-Triebel and Sobolev spaces of functions on open subsets of an Euclidean space defined in terms of differences, local polynomial approximations, wavelet decompositions and other means (as well as the duals and the lp-sums of all these spaces on the other side, allows us to present the algorithm of extending the main results of the article to the latter spaces and pairs. Special attention is paid to the matter of sharpness. Our approach is quasi-Euclidean in its nature because it relies on the extrapolation of properties of Hilbert spaces and the study of 1-complemented subspaces of the spaces under consideration.

Learning by random walks in the weight space of the Ising perceptron

International Nuclear Information System (INIS)

Huang, Haiping; Zhou, Haijun

2010-01-01

Several variants of a stochastic local search process for constructing the synaptic weights of an Ising perceptron are studied. In this process, binary patterns are sequentially presented to the Ising perceptron and are then learned as the synaptic weight configuration is modified through a chain of single- or double-weight flips within the compatible weight configuration space of the earlier learned patterns. This process is able to reach a storage capacity of α≈0.63 for pattern length N = 101 and α≈0.41 for N = 1001. If in addition a relearning process is exploited, the learning performance is further improved to a storage capacity of α≈0.80 for N = 101 and α≈0.42 for N = 1001. We found that, for a given learning task, the solutions constructed by the random walk learning process are separated by a typical Hamming distance, which decreases with the constraint density α of the learning task; at a fixed value of α, the width of the Hamming distance distribution decreases with N

Asymptotic Analysis of Upwind Discontinuous Galerkin Approximation of the Radiative Transport Equation in the Diffusive Limit

KAUST Repository

Guermond, Jean-Luc; Kanschat, Guido

2010-01-01

We revisit some results from M. L. Adams [Nu cl. Sci. Engrg., 137 (2001), pp. 298- 333]. Using functional analytic tools we prove that a necessary and sufficient condition for the standard upwind discontinuous Galerkin approximation to converge to the correct limit solution in the diffusive regime is that the approximation space contains a linear space of continuous functions, and the restrictions of the functions of this space to each mesh cell contain the linear polynomials. Furthermore, the discrete diffusion limit converges in the Sobolev space H1 to the continuous one if the boundary data is isotropic. With anisotropic boundary data, a boundary layer occurs, and convergence holds in the broken Sobolev space H with s < 1/2 only © 2010 Society for Industrial and Applied Mathematics.

Sobolev spaces associated to the harmonic oscillator

Indian Academy of Sciences (India)

We consider the second-order differential operator. H = − + |x|2, x ∈ Rd. (1) ... In other words, the range of the Hermite fractional integral. 337 ... convergence of the solution of the Schrödinger equation (42) to the initial data. Our work was ... Given a multi-index α = (αj )d j=1 ∈ Nd ..... For the second term of (24), we have. ∫.

Existence of solutions to Burgers equations in domains that can be transformed into rectangles

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Yassine Benia

2016-06-01

Full Text Available This work is concerned with Burgers equation $\\partial _{t}u+u\\partial_x u-\\partial _x^2u=f$ (with Dirichlet boundary conditions in the non rectangular domain $\\Omega =\\{(t,x\\in R^2;\\ 0space $L^2(\\Omega $, and the initial condition is in the usual Sobolev space $H_0^{1}$. Our goal is to establish the existence, uniqueness and the optimal regularity of the solution in the anisotropic Sobolev space.

Highest weight generating functions for hyperKähler T{sup ⋆}(G/H) spaces

Energy Technology Data Exchange (ETDEWEB)

Hanany, Amihay [Theoretical Physics Group, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom); Ramgoolam, Sanjaye [Centre for Research in String Theory,School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Rodriguez-Gomez, Diego [Department of Physics, Universidad de Oviedo,Avda. Calvo Sotelo 18, 33007, Oviedo (Spain)

2016-10-05

We develop an efficient procedure for counting holomorphic functions on a hyperKahler cone that has a resolution as a cotangent bundle of a homogeneous space by providing a formula for computing the corresponding Highest Weight Generating function.

How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping.

Directory of Open Access Journals (Sweden)

Annie A Butler

Full Text Available We know much about mechanisms determining the perceived size and weight of lifted objects, but little about how these properties of size and weight affect the body representation (e.g. grasp aperture of the hand. Without vision, subjects (n = 16 estimated spacing between fingers and thumb (perceived grasp aperture while lifting canisters of the same width (6.6cm but varied weights (300, 600, 900, and 1200 g. Lifts were performed by movement of either the wrist, elbow or shoulder to examine whether lifting with different muscle groups affects the judgement of grasp aperture. Results for perceived grasp aperture were compared with changes in perceived weight of objects of different sizes (5.2, 6.6, and 10 cm but the same weight (600 g. When canisters of the same width but different weights were lifted, perceived grasp aperture decreased 4.8% [2.2 ‒ 7.4] (mean [95% CI]; P < 0.001 from the lightest to the heaviest canister, no matter how they were lifted. For objects of the same weight but different widths, perceived weight decreased 42.3% [38.2 ‒ 46.4] from narrowest to widest (P < 0.001, as expected from the size-weight illusion. Thus, despite a highly distorted perception of the weight of objects based on their size, we conclude that proprioceptive afferents maintain a reasonably stable perception of the aperture of the grasping hand over a wide range of object weights. Given the small magnitude of this 'weight-grasp aperture' illusion, we propose the brain has access to a relatively stable 'perceptual ruler' to aid the manipulation of different objects.

Green Space and Child Weight Status: Does Outcome Measurement Matter? Evidence from an Australian Longitudinal Study

Directory of Open Access Journals (Sweden)

Taren Sanders

2015-01-01

Full Text Available Objective. To examine whether neighbourhood green space is beneficially associated with (i waist circumference (WC and (ii waist-to-height ratio (WtHR across childhood. Methods. Gender-stratified multilevel linear regressions were used to examine associations between green space and objective measures of weight status in the Longitudinal Study of Australian Children, a nationally representative source of data on 4,423 children aged 6 y to 13 y. WC and WtHR were measured objectively. Percentage green space within the local area of residence was calculated. Effect modification by age was explored, adjusting for socioeconomic confounding. Results. Compared to peers with 0–5% green space locally, boys and girls with >40% green space tended to have lower WC (βboys  −1.15, 95% CI −2.44, 0.14; βgirls  −0.21, 95% CI −1.47, 1.05 and WtHR (βboys  −0.82, 95% CI −1.65, 0.01; βgirls  −0.32, 95% CI −1.13, 0.49. Associations among boys were contingent upon age (p  valuesage∗green  space40% green space at 73.85 cm and 45.75% compared to those with 0–5% green space at 75.18 cm and 46.62%, respectively. Conclusions. Greener neighbourhoods appear beneficial to alternative child weight status measures, particularly among boys.

C1,1 regularity for degenerate elliptic obstacle problems

Science.gov (United States)

Daskalopoulos, Panagiota; Feehan, Paul M. N.

2016-03-01

The Heston stochastic volatility process is a degenerate diffusion process where the degeneracy in the diffusion coefficient is proportional to the square root of the distance to the boundary of the half-plane. The generator of this process with killing, called the elliptic Heston operator, is a second-order, degenerate-elliptic partial differential operator, where the degeneracy in the operator symbol is proportional to the distance to the boundary of the half-plane. In mathematical finance, solutions to the obstacle problem for the elliptic Heston operator correspond to value functions for perpetual American-style options on the underlying asset. With the aid of weighted Sobolev spaces and weighted Hölder spaces, we establish the optimal C 1 , 1 regularity (up to the boundary of the half-plane) for solutions to obstacle problems for the elliptic Heston operator when the obstacle functions are sufficiently smooth.

The Laplace equation boundary value problems on bounded and unbounded Lipschitz domains

CERN Document Server

Medková, Dagmar

2018-01-01

This book is devoted to boundary value problems of the Laplace equation on bounded and unbounded Lipschitz domains. It studies the Dirichlet problem, the Neumann problem, the Robin problem, the derivative oblique problem, the transmission problem, the skip problem and mixed problems. It also examines different solutions - classical, in Sobolev spaces, in Besov spaces, in homogeneous Sobolev spaces and in the sense of non-tangential limit. It also explains relations between different solutions. The book has been written in a way that makes it as readable as possible for a wide mathematical audience, and includes all the fundamental definitions and propositions from other fields of mathematics. This book is of interest to research students, as well as experts in partial differential equations and numerical analysis.

Local existence of solutions to the Euler-Poisson system, including densities without compact support

Science.gov (United States)

Brauer, Uwe; Karp, Lavi

2018-01-01

Local existence and well posedness for a class of solutions for the Euler Poisson system is shown. These solutions have a density ρ which either falls off at infinity or has compact support. The solutions have finite mass, finite energy functional and include the static spherical solutions for γ = 6/5. The result is achieved by using weighted Sobolev spaces of fractional order and a new non-linear estimate which allows to estimate the physical density by the regularised non-linear matter variable. Gamblin also has studied this setting but using very different functional spaces. However we believe that the functional setting we use is more appropriate to describe a physical isolated body and more suitable to study the Newtonian limit.

Partial Regularity for Holonomic Minimisers of Quasiconvex Functionals

Science.gov (United States)

Hopper, Christopher P.

2016-10-01

We prove partial regularity for local minimisers of certain strictly quasiconvex integral functionals, over a class of Sobolev mappings into a compact Riemannian manifold, to which such mappings are said to be holonomically constrained. Our approach uses the lifting of Sobolev mappings to the universal covering space, the connectedness of the covering space, an application of Ekeland's variational principle and a certain tangential A-harmonic approximation lemma obtained directly via a Lipschitz approximation argument. This allows regularity to be established directly on the level of the gradient. Several applications to variational problems in condensed matter physics with broken symmetries are also discussed, in particular those concerning the superfluidity of liquid helium-3 and nematic liquid crystals.

14 CFR 25.1519 - Weight, center of gravity, and weight distribution.

Science.gov (United States)

2010-01-01

... Information Operating Limitations § 25.1519 Weight, center of gravity, and weight distribution. The airplane weight, center of gravity, and weight distribution limitations determined under §§ 25.23 through 25.27... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight, center of gravity, and weight...

On the convergence of nonlinear Beltrami type operators

Directory of Open Access Journals (Sweden)

Riccardo De Arcangelis

1986-11-01

Full Text Available One of the results proved is the following: if (fh is a sequence of K-quasiregular mappings, converging to f  in L1loc , whose jacobians verify a weak integrability condition, then the solutions of Dirichlet problems for the nonlinear Laplace-Beltrami operator associated to each fh converge to the solution of the Dirichlet problem for the nonlinear Laplace-Beltrami operator associated to f. Such result is deduced as a particular case of a more general theorem concerning nonlinear operators. The case of K-quasiconformal functions fh is also treated. A class of weighted Sobolev spaces associated to quasiconformal mappings is studied.

Critical imbeddings with multivariate rearrangements

Czech Academy of Sciences Publication Activity Database

Krbec, Miroslav; Schmeisser, H.-J.

2007-01-01

Roč. 181, č. 3 (2007), s. 255-284 ISSN 0039-3223 R&D Projects: GA ČR(CZ) GA201/06/0400 Institutional research plan: CEZ:AV0Z10190503 Keywords : Sobolev spaces * Bessel potential spaces * Besov spaces Subject RIV: BA - General Mathematics Impact factor: 0.568, year: 2007

Ultra High Temperature and Multifunctional Ceramic Matrix Composite – Coating Systems for Light-Weight Space and Aero Systems

Data.gov (United States)

National Aeronautics and Space Administration — Revolutionary ultra-high temperature, high mechanical loading capable, oxidation resistant, durable ceramic coatings and light-weight fiber-reinforced Ceramic Matrix...

On solution of Maxwell's equations in axisymmetric domains with edges. Part I: Theoretical aspects

International Nuclear Information System (INIS)

Nkemzi, Boniface

2003-10-01

In this paper we present the basic mathematical tools for treating boundary value problems for the Maxwell's equations in three-dimensional axisymmetric domains with reentrant edges by means of partial Fourier analysis. We consider the decomposition of the classical and regularized time-harmonic three-dimensional Maxwell's equations into variational equations in the plane meridian domain of the axisymmetric domain and define suitable weighted Sobolev spaces for their treatment. The trace properties of these spaces on the rotational axis and some properties of the solutions are proved, which are important for further numerical treatment, e.g. by the finite-element method. Particularly, a priori estimates of the solutions of the reduced system are given and the asymptotic behavior of these solutions near reentrant corners of the meridian domain is explicitly described by suitable singular functions. (author)

Partial differential operators of elliptic type

CERN Document Server

Shimakura, Norio

1992-01-01

This book, which originally appeared in Japanese, was written for use in an undergraduate course or first year graduate course in partial differential equations and is likely to be of interest to researchers as well. This book presents a comprehensive study of the theory of elliptic partial differential operators. Beginning with the definitions of ellipticity for higher order operators, Shimakura discusses the Laplacian in Euclidean spaces, elementary solutions, smoothness of solutions, Vishik-Sobolev problems, the Schauder theory, and degenerate elliptic operators. The appendix covers such preliminaries as ordinary differential equations, Sobolev spaces, and maximum principles. Because elliptic operators arise in many areas, readers will appreciate this book for the way it brings together a variety of techniques that have arisen in different branches of mathematics.

Curve Matching with Applications in Medical Imaging

DEFF Research Database (Denmark)

Bauer, Martin; Bruveris, Martins; Harms, Philipp

2015-01-01

In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several...

Nonlinear analysis

CERN Document Server

Gasinski, Leszek

2005-01-01

Hausdorff Measures and Capacity. Lebesgue-Bochner and Sobolev Spaces. Nonlinear Operators and Young Measures. Smooth and Nonsmooth Analysis and Variational Principles. Critical Point Theory. Eigenvalue Problems and Maximum Principles. Fixed Point Theory.

On a non-linear pseudodifferential boundary value problem

International Nuclear Information System (INIS)

Nguyen Minh Chuong.

1989-12-01

A pseudodifferential boundary value problem for operators with symbols taking values in Sobolev spaces and with non-linear right-hand side was studied. Existence and uniqueness theorems were proved. (author). 11 refs

On the formula of Jacques-Louis Lions for reproducing kernels of harmonic and other functions

Czech Academy of Sciences Publication Activity Database

Engliš, Miroslav; Lukkassen, D.; Peetre, J.; Persson, L. E.

2004-01-01

Roč. 570, - (2004), s. 89-129 ISSN 0075-4102 R&D Projects: GA AV ČR IAA1019005 Institutional research plan: CEZ:AV0Z1019905 Keywords : formula of Jacques-Louis Lions * Sobolev space * Hilber space Subject RIV: BA - General Mathematics Impact factor: 0.885, year: 2004

Harmonic analysis, partial differential equations and applications in honor of Richard L. Wheeden

CERN Document Server

Franchi, Bruno; Lu, Guozhen; Perez, Carlos; Sawyer, Eric

2017-01-01

This is a collection of contributed papers by many eminent Harmonic Analysts and specialists of Partial Differential equations. The papers focus on weighted norm equalities for singular integrals, focusing wave equations, degenerate elliptic equations, Navier-Stokes flow in two dimensions and Poincare-Sobolev inequalities in the setting of metric spaces equipped with measures among others. Many topics considered in this volume stem from the interests of Richard L. Wheeden whose contributions to Potential Theory, singular integral theory and degenerate elliptic PDE theory this volume honors. Luis Caffarelli, Sagun Chanillo, Bruno Franchi, Cristian Guttierez, Xiaojun Huang, Carlos Kenig, Ermanno Lanconelli, Eric Sawyer and Alexander Volberg, are some of the many contributors to this volume. .

Leslie ja Naomi juhtum / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

2004-01-01

Readingi Ülikoolis (Inglismaa) toimunud feminismikonverentsiga kaasnenud näitusest "Virtue and Vulgarity" ja selle silmapaistvamatest töödest. Analüüsitakse naiste ja meeste kunstile omaseid erinevusi ning võimalust aktsepteerida feminiinsusena ka malbust, alalhoidlikkust. Esitati Mare Tralla CD-ROM "her.space"

Functional analysis and applied optimization in Banach spaces applications to non-convex variational models

CERN Document Server

Botelho, Fabio

2014-01-01

This book introduces the basic concepts of real and functional analysis. It presents the fundamentals of the calculus of variations, convex analysis, duality, and optimization that are necessary to develop applications to physics and engineering problems. The book includes introductory and advanced concepts in measure and integration, as well as an introduction to Sobolev spaces. The problems presented are nonlinear, with non-convex variational formulation. Notably, the primal global minima may not be attained in some situations, in which cases the solution of the dual problem corresponds to an appropriate weak cluster point of minimizing sequences for the primal one. Indeed, the dual approach more readily facilitates numerical computations for some of the selected models. While intended primarily for applied mathematicians, the text will also be of interest to engineers, physicists, and other researchers in related fields.

Proceedings – Mathematical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

In this paper, we compute the Hilbert space adjoint * of the derivative operator on the Hermite Sobolev spaces S q . We use this calculation to give a different proof of the 'monotonicity inequality' for a class of differential operators (, ) for which the inequality was proved in Infin. Dimens. Anal. Quantum Probab. Relat.

Effectiveness of a Rapid Lumbar Spine MRI Protocol Using 3D T2-Weighted SPACE Imaging Versus a Standard Protocol for Evaluation of Degenerative Changes of the Lumbar Spine.

Science.gov (United States)

Sayah, Anousheh; Jay, Ann K; Toaff, Jacob S; Makariou, Erini V; Berkowitz, Frank

2016-09-01

Reducing lumbar spine MRI scanning time while retaining diagnostic accuracy can benefit patients and reduce health care costs. This study compares the effectiveness of a rapid lumbar MRI protocol using 3D T2-weighted sampling perfection with application-optimized contrast with different flip-angle evolutions (SPACE) sequences with a standard MRI protocol for evaluation of lumbar spondylosis. Two hundred fifty consecutive unenhanced lumbar MRI examinations performed at 1.5 T were retrospectively reviewed. Full, rapid, and complete versions of each examination were interpreted for spondylotic changes at each lumbar level, including herniations and neural compromise. The full examination consisted of sagittal T1-weighted, T2-weighted turbo spin-echo (TSE), and STIR sequences; and axial T1- and T2-weighted TSE sequences (time, 18 minutes 40 seconds). The rapid examination consisted of sagittal T1- and T2-weighted SPACE sequences, with axial SPACE reformations (time, 8 minutes 46 seconds). The complete examination consisted of the full examination plus the T2-weighted SPACE sequence. Sensitivities and specificities of the full and rapid examinations were calculated using the complete study as the reference standard. The rapid and full studies had sensitivities of 76.0% and 69.3%, with specificities of 97.2% and 97.9%, respectively, for all degenerative processes. Rapid and full sensitivities were 68.7% and 66.3% for disk herniation, 85.2% and 81.5% for canal compromise, 82.9% and 69.1% for lateral recess compromise, and 76.9% and 69.7% for foraminal compromise, respectively. Isotropic SPACE T2-weighted imaging provides high-quality imaging of lumbar spondylosis, with multiplanar reformatting capability. Our SPACE-based rapid protocol had sensitivities and specificities for herniations and neural compromise comparable to those of the protocol without SPACE. This protocol fits within a 15-minute slot, potentially reducing costs and discomfort for a large subgroup of

Estimate of K-functionals and modulus of smoothness constructed ...

Indian Academy of Sciences (India)

Casablanca, Morocco. E-mail: m_elhamma@yahoo.fr. MS received 17 January 2013. Abstract. Using a generalized spherical mean operator, we define generalized modu- lus of smoothness in the space L2 k. (Rd). Based on the Dunkl operator we define. Sobolev-type space and K-functionals. The main result of the paper ...

A novel variable selection approach that iteratively optimizes variable space using weighted binary matrix sampling.

Science.gov (United States)

Deng, Bai-chuan; Yun, Yong-huan; Liang, Yi-zeng; Yi, Lun-zhao

2014-10-07

In this study, a new optimization algorithm called the Variable Iterative Space Shrinkage Approach (VISSA) that is based on the idea of model population analysis (MPA) is proposed for variable selection. Unlike most of the existing optimization methods for variable selection, VISSA statistically evaluates the performance of variable space in each step of optimization. Weighted binary matrix sampling (WBMS) is proposed to generate sub-models that span the variable subspace. Two rules are highlighted during the optimization procedure. First, the variable space shrinks in each step. Second, the new variable space outperforms the previous one. The second rule, which is rarely satisfied in most of the existing methods, is the core of the VISSA strategy. Compared with some promising variable selection methods such as competitive adaptive reweighted sampling (CARS), Monte Carlo uninformative variable elimination (MCUVE) and iteratively retaining informative variables (IRIV), VISSA showed better prediction ability for the calibration of NIR data. In addition, VISSA is user-friendly; only a few insensitive parameters are needed, and the program terminates automatically without any additional conditions. The Matlab codes for implementing VISSA are freely available on the website: https://sourceforge.net/projects/multivariateanalysis/files/VISSA/.

Existence and multiplicity of weak solutions for a class of degenerate nonlinear elliptic equations

Directory of Open Access Journals (Sweden)

Mihăilescu Mihai

2006-01-01

Full Text Available The goal of this paper is to study the existence and the multiplicity of non-trivial weak solutions for some degenerate nonlinear elliptic equations on the whole space . The solutions will be obtained in a subspace of the Sobolev space . The proofs rely essentially on the Mountain Pass theorem and on Ekeland's Variational principle.

Global weak solution for a equations in plasma

International Nuclear Information System (INIS)

Guo Boling; Huang Daiwen

2010-01-01

The existence of global weak solutions of the initial boundary value problem to a simplified equations, derived from the equations of two fluid system in plasma, is proven by using energy method and some embedding theorems in Sobolev-Orlicz space.

Realizations of the canonical representation

Indian Academy of Sciences (India)

Traditionally, the canonical representation is realized on the Hilbert space ... Fix a decomposition R2n = Rn × Rn ..... to an orthonormal basis {ψ1,ψ2,. ..... [7] Vemuri M K, A non-commutative Sobolev inequality and its application to spectral.

Stability estimates for h-p spectral element methods for elliptic ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

With this mesh we seek a solution which minimizes a weighted ... uniform mesh; fractional Sobolev norms; stability estimate; polylogarithmic bounds. ... In [6,7] we restrict ourselves to examining the Poisson's equation with ... it by stating the stability theorem 3.1 for a simpler case. ..... And this gives us the following inequality:.

Existence and multiplicity of weak solutions for a class of degenerate nonlinear elliptic equations

Directory of Open Access Journals (Sweden)

Mihai Mihăilescu

2006-02-01

Full Text Available The goal of this paper is to study the existence and the multiplicity of non-trivial weak solutions for some degenerate nonlinear elliptic equations on the whole space RN. The solutions will be obtained in a subspace of the Sobolev space W1/p(RN. The proofs rely essentially on the Mountain Pass theorem and on Ekeland's Variational principle.

Weight window/importance generator for Monte Carlo streaming problems

International Nuclear Information System (INIS)

Booth, T.E.

1983-01-01

A Monte Carlo method for solving highly angle dependent streaming problems is described. The method uses a DXTRAN-like angle biasing scheme, a space-angle weight window to reduce weight fluctuations introduced by the angle biasing, and a space-angle importance generator to set parameters for the space-angle weight window. Particle leakage through a doubly-bent duct is calculated to demonstrate the method's use

Existence of infinitely many solutions for degenerate and singular elliptic systems with indefinite concave nonlinearities

Directory of Open Access Journals (Sweden)

Nguyen Thanh Chung

2011-02-01

Full Text Available In this article, we consider degenerate and singular elliptic systems of the form $$displaylines{ - hbox{div}(h_1(xabla u = b_1(x|u|^{r-2}u + F_u(x,u,v quad hbox{in } Omega,cr - hbox{div}(h_2(xabla v = b_2(x|v|^{r-2}v + F_v(x,u,v quad hbox{in } Omega, }$$ where $Omega$ is a bounded domain in $mathbb{R}^N$, $N geq 2$, with smooth boundary $partialOmega$; $h_i: Omega o [0, infty$, $h_i in L^1_{loc}(Omega$, and are allowed to have ``essential'' zeroes; $1 < r < 2$; the weight functions $b_i: Omega o mathbb{R}$, may be sign-changing; and $(F_u,F_v = abla F$. Using variational techniques, a variant of the Caffarelli - Kohn - Nirenberg inequality, and a variational principle by Clark [9], we prove the rxistence of infinitely many solutions in a weighted Sobolev space.

Weighted regularized statistical shape space projection for breast 3D model reconstruction.

Science.gov (United States)

Ruiz, Guillermo; Ramon, Eduard; García, Jaime; Sukno, Federico M; Ballester, Miguel A González

2018-05-02

The use of 3D imaging has increased as a practical and useful tool for plastic and aesthetic surgery planning. Specifically, the possibility of representing the patient breast anatomy in a 3D shape and simulate aesthetic or plastic procedures is a great tool for communication between surgeon and patient during surgery planning. For the purpose of obtaining the specific 3D model of the breast of a patient, model-based reconstruction methods can be used. In particular, 3D morphable models (3DMM) are a robust and widely used method to perform 3D reconstruction. However, if additional prior information (i.e., known landmarks) is combined with the 3DMM statistical model, shape constraints can be imposed to improve the 3DMM fitting accuracy. In this paper, we present a framework to fit a 3DMM of the breast to two possible inputs: 2D photos and 3D point clouds (scans). Our method consists in a Weighted Regularized (WR) projection into the shape space. The contribution of each point in the 3DMM shape is weighted allowing to assign more relevance to those points that we want to impose as constraints. Our method is applied at multiple stages of the 3D reconstruction process. Firstly, it can be used to obtain a 3DMM initialization from a sparse set of 3D points. Additionally, we embed our method in the 3DMM fitting process in which more reliable or already known 3D points or regions of points, can be weighted in order to preserve their shape information. The proposed method has been tested in two different input settings: scans and 2D pictures assessing both reconstruction frameworks with very positive results. Copyright © 2018 Elsevier B.V. All rights reserved.

Fulltext PDF

Indian Academy of Sciences (India)

Abstract Cauchy problem. Multiplicative perturbations of local. C-semigroups. 45. Action. Pullback and pushout crossed poly- modules. 11. Adjoint operators. Differential operators on Hermite. Sobolev spaces. 113. Almost Koszul algebras. Yoneda algebras of almost Koszul algebras. 477. Almost product structure. On the (1 ...

Removability of singularity for nonlinear elliptic equations with p(x-growth

Directory of Open Access Journals (Sweden)

Yongqiang Fu

2013-09-01

Full Text Available Using Moser's iteration method, we investigate the problem of removable isolated singularities for elliptic equations with p(x-type nonstandard growth. We give a sufficient condition for removability of singularity for the equations in the framework of variable exponent Sobolev spaces.

Embeddings relations between weighted complementary Local Morrey-type spaces and weighted local Morrey-type spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Mustafayev, R.Ch.; Ünver, T.

2017-01-01

Roč. 8, č. 1 (2017), s. 34-49 ISSN 2077-9879 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : local Morrey-type spaces * embeddings * iterated Hardy inequalities Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics http://www.mathnet.ru/ php /archive.phtml?wshow=paper&jrnid=emj&paperid=246&option_lang=rus

Embeddings relations between weighted complementary Local Morrey-type spaces and weighted local Morrey-type spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Mustafayev, R.Ch.; Ünver, T.

2017-01-01

Roč. 8, č. 1 (2017), s. 34-49 ISSN 2077-9879 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : local Morrey-type spaces * embeddings * iterated Hardy inequalities Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=emj&paperid=246&option_lang=rus

14 CFR 27.1519 - Weight and center of gravity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight and center of gravity. 27.1519 Section 27.1519 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Operating Limitations § 27.1519 Weight and center of gravity. The weight and center of gravity limitations...

14 CFR 29.1519 - Weight and center of gravity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight and center of gravity. 29.1519 Section 29.1519 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Operating Limitations § 29.1519 Weight and center of gravity. The weight and center of gravity limitations...

14 CFR 23.1519 - Weight and center of gravity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight and center of gravity. 23.1519 Section 23.1519 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Limitations and Information § 23.1519 Weight and center of gravity. The weight and center of gravity...

A posteriori error estimates for axisymmetric and nonlinear problems

Czech Academy of Sciences Publication Activity Database

Křížek, Michal; Němec, J.; Vejchodský, Tomáš

2001-01-01

Roč. 15, - (2001), s. 219-236 ISSN 1019-7168 R&D Projects: GA ČR GA201/01/1200; GA MŠk ME 148 Keywords : weigted Sobolev spaces%a posteriori error estimates%finite elements Subject RIV: BA - General Mathematics Impact factor: 0.886, year: 2001

Invariant differential operators on H-type groups and discrete components in restrictions of complementary series of rank one semisimple groups

DEFF Research Database (Denmark)

Möllers, Jan; Ørsted, Bent; Zhang, Genkai

2016-01-01

We explicitly construct a finite number of discrete components in the restriction of complementary series representations of rank one semisimple groups $G$ to rank one subgroups $G_1$. For this we use the realizations of complementary series representations of $G$ and $G_1$ on Sobolev spaces...

Proceedings – Mathematical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

We establish a sharp Trudinger–Moser type inequality invoking a Hardy inequality for any even dimension. This leads to a non compact Sobolev embedding in some Orlicz space. We also give a description of the lack of compactness of this embedding in the spirit of [8].

On Coupled System of Navier-Stokes Equations and Temperature

African Journals Online (AJOL)

Dr. Anthony Peter

ABSTRACT. This paper deals with the coupled system of Navier-Stokes equations and temperature (Thermohydraulics) in a strip in the class of spatially non-decaying (infinite-energy) solutions belonging to the properly chosen uniformly local Sobolev spaces. The global well-posedness and dissipativity of the Navier- ...

Realizing spaces as path-component spaces

OpenAIRE

Banakh, Taras; Brazas, Jeremy

2018-01-01

The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

A numerical method for solving singular De`s

Energy Technology Data Exchange (ETDEWEB)

Mahaver, W.T.

1996-12-31

A numerical method is developed for solving singular differential equations using steepest descent based on weighted Sobolev gradients. The method is demonstrated on a variety of first and second order problems, including linear constrained, unconstrained, and partially constrained first order problems, a nonlinear first order problem with irregular singularity, and two second order variational problems.

Remarks on a Class of Nonlinear Schrödinger Equations with Potential Vanishing at Infinity

Directory of Open Access Journals (Sweden)

Hongbo Zhu

2013-01-01

Full Text Available We study the following nonlinear Schrödinger equation −Δu+V(xu=K(xf(u,  x∈ℝN,  u∈H1(ℝN, where the potential V(x vanishes at infinity. Working in weighted Sobolev space, we obtain the ground states of problem ( under a Nahari type condition. Furthermore, if V(x,K(x are radically symmetric with respect to x∈ℝN, it is shown that problem ( has a positive solution with some more general growth conditions of the nonlinearity. Particularly, if f(u=up, then the growth restriction σ≤p≤N+2/N-2 in Ambrosetti et al. (2005 can be relaxed to σ~≤p≤N+2/N-2, where σ~<σ if 0<β<α<2.

Contrast-enhanced MR imaging of metastatic brain tumor at 3 Tesla. Utility of T1-weighted SPACE compared with 2D spin echo and 3D gradient echo sequence

International Nuclear Information System (INIS)

Komada, Tomohiro; Naganawa, Shinji; Ogawa, Hiroshi

2008-01-01

We evaluated the newly developed whole-brain, isotropic, 3-dimensional turbo spin-echo imaging with variable flip angle echo train (SPACE) for contrast-enhanced T 1 -weighted imaging in detecting brain metastases at 3 tesla (T). Twenty-two patients with suspected brain metastases underwent postcontrast study with SPACE, magnetization-prepared rapid gradient-echo (MP-RAGE), and 2-dimensional T 1 -weighted spin echo (2D-SE) imaging at 3 T. We quantitatively compared SPACE, MP-RAGE, and 2D-SE images by using signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM) and contrast-to-noise ratios (CNRs) for GM-to-WM, lesion-to-GM, and lesion-to-WM. Two blinded radiologists evaluated the detection of brain metastases by segment-by-segment analysis and continuously-distributed test. The CNR between GM and WM was significantly higher on MP-RAGE images than on SPACE images (P 1 -weighted imaging. (author)

Corridengum: Linear and fractional response for the SRB measure of smooth hyperbolic attractors and discontinuous observables (2017 Nonlinearity 30 1204)

Science.gov (United States)

Baladi, Viviane; Kuna, Tobias; Lucarini, Valerio

2017-08-01

The first main result of Baladi et al (2017 Nonlinearity 30 1204-20) is modified as follows: For any θ in the Sobolev space H^r_p(M) , with 1 and 0, the map t\\mapsto \\int θ dρt is α-Hölder continuous for all \

Proceedings – Mathematical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Proceedings – Mathematical Sciences. Suprio Bhar. Articles written in Proceedings – Mathematical Sciences. Volume 125 Issue 1 February 2015 pp 113-125. Differential operators on Hermite Sobolev spaces · Suprio Bhar B Rajeev · More Details Abstract Fulltext PDF. In this paper, we compute the Hilbert ...

Divergence-Free Wavelets on the Hypercube : General Boundary Conditions

NARCIS (Netherlands)

Stevenson, R.

2016-01-01

On the n-dimensional hypercube, for given k∈N, wavelet Riesz bases are constructed for the subspace of divergence-free vector fields of the Sobolev space Hk((0,1)n)n with general homogeneous Dirichlet boundary conditions, including slip or no-slip boundary conditions. Both primal and suitable dual

A Gauss-Newton method for the integration of spatial normal fields in shape Space

KAUST Repository

Balzer, Jonathan

2011-08-09

We address the task of adjusting a surface to a vector field of desired surface normals in space. The described method is entirely geometric in the sense, that it does not depend on a particular parametrization of the surface in question. It amounts to solving a nonlinear least-squares problem in shape space. Previously, the corresponding minimization has been performed by gradient descent, which suffers from slow convergence and susceptibility to local minima. Newton-type methods, although significantly more robust and efficient, have not been attempted as they require second-order Hadamard differentials. These are difficult to compute for the problem of interest and in general fail to be positive-definite symmetric. We propose a novel approximation of the shape Hessian, which is not only rigorously justified but also leads to excellent numerical performance of the actual optimization. Moreover, a remarkable connection to Sobolev flows is exposed. Three other established algorithms from image and geometry processing turn out to be special cases of ours. Our numerical implementation founds on a fast finite-elements formulation on the minimizing sequence of triangulated shapes. A series of examples from a wide range of different applications is discussed to underline flexibility and efficiency of the approach. © 2011 Springer Science+Business Media, LLC.

Strichartz Estimates for the Schrödinger Equation

OpenAIRE

CORDERO, ELENA; ZUCCO, DAVIDE

2010-01-01

The objective of this paper is to report on recent progress on Strichartz estimates for the Schrödinger equation and to present the state-of-the-art. These estimates have been obtained in Lebesgue spaces, Sobolev spaces and, recently, in Wiener amalgam and modulation spaces. We present and compare the different technicalities. Then, we illustrate applications to well-posedness. El objetivo de este trabajo es reportar los progresos recientes sobre estimativas de Strichartz para la ecuación ...

Cryogenic explosion environment modeling and testing of space shuttle and light-weight radioisotope heater unit interactions

International Nuclear Information System (INIS)

Johnson, E.W.

1985-10-01

In order to assess the risk to the world's populace in the event of a Space Shuttle accident when radioisotope-containing heat sources are on board, testing of that system must be performed to determine release point, environments required, and the size distribution of the released fuel. To evaluate the performance of the Light-Weight Radioisotope Heater Unit (LWRHU) (101 of these 1-W items are placed on the Galileo spacecraft which will be launched from the Space Shuttle), some high-velocity impact and flyer plate testing was carried out. The results showed that a bare urania-fueled LWRHU clad (approximately 1-mm thick platinum-30 wt % rhodium alloy) will withstand 1100 m/s flyer plate (3.5-mm thick aluminum) impacts and 330 m/s impacts upon the Space Shuttle floor (approximately 12-mm thick aluminum) without rupture or fuel release. Velocities in the order of 600 m/s on a steel surface will cause clad failure with fuel release. The fuel breakup patterns were characterized as to quantity in a specific size range. These data were employed in the formal Safety Analysis Report for the LWRHU to support the planned 1986 Galileo launch. 19 figs

Primary Dendrite Arm Spacing and Trunk Diameter in Al-7-Weight-Percentage Si Alloy Directionally Solidified Aboard the International Space Station

Science.gov (United States)

Ghods, M.; Tewari, S. N.; Lauer, M.; Poirier, D. R.; Grugel, R. N.

2016-01-01

Under a NASA-ESA collaborative research project, three Al-7-weight-percentage Si samples (MICAST-6, MICAST-7 and MICAST 2-12) were directionally solidified aboard the International Space Station to determine the effect of mitigating convection on the primary dendrite array. The samples were approximately 25 centimeters in length with a diameter of 7.8 millimeter-diameter cylinders that were machined from [100] oriented terrestrially grown dendritic Al-7Si samples and inserted into alumina ampoules within the Sample Cartridge Assembly (SCA) inserts of the Low Gradient Furnace (LGF). The feed rods were partially remelted in space and directionally solidified to effect the [100] dendrite-orientation. MICAST-6 was grown at 5 microns per second for 3.75 centimeters and then at 50 microns per second for its remaining 11.2 centimeters of its length. MICAST-7 was grown at 20 microns per second for 8.5 centimeters and then at 10 microns per second for 9 centimeters of its remaining length. MICAST2-12 was grown at 40 microns per second for 11 centimeters. The thermal gradient at the liquidus temperature varied from 22 to 14 degrees Kelvin per centimeter during growth of MICAST-6, from 26 to 24 degrees Kelvin per centimeter for MICAST-7 and from 33 to 31 degrees Kelvin per centimeter for MICAST2-12. Microstructures on the transverse sections along the sample length were analyzed to determine nearest-neighbor spacing of the primary dendrite arms and trunk diameters of the primary dendrite-arrays. This was done along the lengths where steady-state growth prevailed and also during the transients associated with the speed-changes. The observed nearest-neighbor spacings during steady-state growth of the MICAST samples show a very good agreement with predictions from the Hunt-Lu primary spacing model for diffusion controlled growth. The observed primary dendrite trunk diameters during steady-state growth of these samples also agree with predictions from a coarsening-based model

Integral functionals that are continuous with respect to the weak topology on W-0(1,p)(Omega)

Czech Academy of Sciences Publication Activity Database

Černý, R.; Hencl, S.; Kolář, Jan

2009-01-01

Roč. 71, 7-8 (2009), s. 2753-2763 ISSN 0362-546X R&D Projects: GA ČR GA201/06/0018 Institutional research plan: CEZ:AV0Z10190503 Keywords : weak continuity * nonlinear integral functional * Sobolev spaces * linearity Subject RIV: BA - General Mathematics Impact factor: 1.487, year: 2009

A remark about the mean curvature

International Nuclear Information System (INIS)

Zhang Weitao.

1992-11-01

In this paper, we give an integral identity about the mean curvature in Sobolev space H 0 1 (Ω) intersection H 2 (Ω). Suppose the mean curvature on Γ=δΩ is positive, we prove some inequalities of the positive mean curvature and propose some open problems. (author). 4 refs

A boundary-value problem in weighted Hölder spaces for elliptic equations which degenerate at the boundary of the domain

Energy Technology Data Exchange (ETDEWEB)

Bazalii, B V; Degtyarev, S P [Institute of Applied Mathematics and Mechanics, National Academy of Sciences of Ukraine, Donetsk (Ukraine)

2013-07-31

An elliptic boundary-value problem for second-order equations with nonnegative characteristic form is investigated in the situation when there is a weak degeneracy on the boundary of the domain. A priori estimates are obtained for solutions and the problem is proved to be solvable in some weighted Hölder spaces. Bibliography: 18 titles.

About One Approach to Determine the Weights of the State Space Method

Directory of Open Access Journals (Sweden)

I. K. Romanova

2015-01-01

Full Text Available The article studies methods of determining weight coefficients, also called coefficients of criteria importance in multiobjective optimization (MOO. It is assumed that these coefficients indicate a degree of individual criteria influence on the final selection (final or summary assessment: the more is coefficient, the greater is contribution of its corresponding criterion.Today in the framework of modern information systems to support decision making for various purposes a number of methods for determining relative importance of criteria has been developed. Among those methods we can distinguish a utility method, method of weighted power average; weighted median; method of matching clustered rankings, method of paired comparison of importance, etc.However, it should be noted that different techniques available for calculating weights does not eliminate the main problem of multicriteria optimization namely, the inconsistency of individual criteria. The basis for solving multicriteria problems is a fundamental principle of multi-criteria selection i.e. Edgeworth - Pareto principle.Despite a large number of methods to determine the weights, the task remains relevant not only for reasons of evaluations subjectivity, but also because of the mathematical aspects. Today, recognized is the fact that, for example, such a popular method as linear convolution of private criteria, essentially, represents one of the heuristic approaches and, applying it, you can have got not the best final choice. Carlin lemma reflects the limits of the method application.The aim of this work is to offer one of the methods to calculate the weights applied to the problem of dynamic system optimization, the quality of which is determined by the criterion of a special type, namely integral quadratic quality criterion. The main challenge relates to the method of state space, which in the literature also is called the method of analytical design of optimal controllers.Despite the

T2-weighted MR imaging of the liver: Qualitative and quantitative comparison of SPACE MR imaging with turbo spin-echo MR imaging

Energy Technology Data Exchange (ETDEWEB)

Dohan, Anthony, E-mail: anthony.dohan@lrb.aphp.fr [Department of Body and Interventional Imaging, Hôpital Lariboisière, AP-HP, 2 Rue Ambroise Paré, 75475 Paris Cedex 10 (France); Université Paris-Diderot, Sorbonne Paris Cité, 10 Rue de Verdun, 75010 Paris (France); UMR INSERM 965, Hôpital Lariboisière, 2 Rue Amboise Paré, 75010 Paris (France); Gavini, Jean-Philippe, E-mail: jpgavini@gmail.com [Department of Body and Interventional Imaging, Hôpital Lariboisière, AP-HP, 2 Rue Ambroise Paré, 75475 Paris Cedex 10 (France); Université Paris-Diderot, Sorbonne Paris Cité, 10 Rue de Verdun, 75010 Paris (France); Placé, Vinciane, E-mail: vinciane.place@gmail.com [Department of Body and Interventional Imaging, Hôpital Lariboisière, AP-HP, 2 Rue Ambroise Paré, 75475 Paris Cedex 10 (France); Sebbag, Delphine, E-mail: delphinesebbag@gmail.com [Department of Body and Interventional Imaging, Hôpital Lariboisière, AP-HP, 2 Rue Ambroise Paré, 75475 Paris Cedex 10 (France); Université Paris-Diderot, Sorbonne Paris Cité, 10 Rue de Verdun, 75010 Paris (France); Vignaud, Alexandre, E-mail: alexandre.vignaud@cea.fr [LRMN, Neurospin, CEA-SACLAY, Bâtiment 145, 91 191 Gif-sur-Yvette Cedex (France); and others

2013-11-01

Objective: To qualitatively and quantitatively compare T2-weighted MR imaging of the liver using volumetric spin-echo with sampling perfection with application-optimized contrast using different flip angle evolutions (SPACE) with conventional turbo spin-echo (TSE) sequence for fat-suppressed T2-weighted MR imaging of the liver. Materials and methods: Thirty-three patients with suspected focal liver lesions had SPACE MR imaging and conventional fat-suppressed TSE MR imaging. Images were analyzed quantitatively by measuring the lesion-to-liver contrast-to-noise ratio (CNR), and the signal-to-noise ratio (SNR) of main focal hepatic lesions, hepatic and splenic parenchyma and qualitatively by evaluating the presence of vascular, respiratory motion and cardiac artifacts. Wilcoxon signed rank test was used to search for differences between the two sequences. Results: SPACE MR imaging showed significantly greater CNR for focal liver lesions (median = 22.82) than TSE MR imaging (median = 14.15) (P < .001). No differences were found for SNR of hepatic parenchyma (P = .097), main focal hepatic lesions (P = .35), and splenic parenchyma (P = .25). SPACE sequence showed less artifacts than TSE sequence (vascular, P < .001; respiratory motion, P < .001; cardiac, P < .001) but needed a longer acquisition time (228.4 vs. 162.1 s; P < .001). Conclusion: SPACE MR imaging provides a significantly increased CNR for focal liver lesions and less artifacts by comparison with the conventional TSE sequence. These results should stimulate further clinical studies with a surgical standard of reference to compare the two techniques in terms of sensitivity for malignant lesions.

Fulltext PDF

Indian Academy of Sciences (India)

Natterer [4] introduced Sobolev space theory in developing error analysis theorems for CT images. Munshi et al [5] followed this work and carried out a precise quantification of these errors resulting in an approximate error formula for the CBP algorithm [6]. This for- mula was verified numerically [7] as well as experimentally ...

Inverse Problems for a Parabolic Integrodifferential Equation in a Convolutional Weak Form

Directory of Open Access Journals (Sweden)

Kairi Kasemets

2013-01-01

Full Text Available We deduce formulas for the Fréchet derivatives of cost functionals of several inverse problems for a parabolic integrodifferential equation in a weak formulation. The method consists in the application of an integrated convolutional form of the weak problem and all computations are implemented in regular Sobolev spaces.

Third-order operator-differential equations with discontinuous coefficients and operators in the boundary conditions

Directory of Open Access Journals (Sweden)

Araz R. Aliev

2013-10-01

Full Text Available We study a third-order operator-differential equation on the semi-axis with a discontinuous coefficient and boundary conditions which include an abstract linear operator. Sufficient conditions for the well-posed and unique solvability are found by means of properties of the operator coefficients in a Sobolev-type space.

Associations of neighbourhood walkability indices with weight gain.

Science.gov (United States)

Koohsari, Mohammad Javad; Oka, Koichiro; Shibata, Ai; Liao, Yung; Hanibuchi, Tomoya; Owen, Neville; Sugiyama, Takemi

2018-04-03

Inconsistent associations of neighbourhood walkability with adults' body weight have been reported. Most studies examining the relationships of walkability and adiposity are cross-sectional in design. We examined the longitudinal relationships of two walkability indices - conventional walkability and space syntax walkability, and their individual components, with weight change among adults over four years. Data were from the Physical Activity in Localities and Community study in Adelaide, Australia. In 2003-2004, 2650 adults living in 154 Census Collection Districts (CCDs) returned baseline questionnaires; in 2007-2008, the follow-up survey was completed by 1098. Participants reported their weight at baseline and at follow-up. Neighbourhood walkability indices were calculated using geographic information systems and space syntax software. Linear marginal models using generalized estimating equations with robust standard errors were fitted to examine associations of the two walkability indices and their individual components with the weight at follow-up, adjusting for baseline weight, socio-demographic variables, and spatial clustering at the level of CCD. The overall mean weight gain over four years was 1.5 kg. The two walkability indices were closely correlated (r = 0.76, p walkability indices and weight change. Among walkability components, there was a marginally significant negative association between space syntax measure of street integration and weight change: one standard deviation increment in street integration was associated with 0.31 kg less weight gain (p = 0.09). Using a prospective study design and a novel space-syntax based measure of walkability, we were not able to identify relationships between neighbourhood walkability with weight gain. This is consistent with other inconclusive findings on the built environment and obesity. Research on the built environment and adults' weight gain may need to consider not just local environments but

Fractional multilinear integrals with rough kernels on generalized weighted Morrey spaces

Directory of Open Access Journals (Sweden)

Akbulut Ali

2016-01-01

Full Text Available In this paper, we study the boundedness of fractional multilinear integral operators with rough kernels TΩ,αA1,A2,…,Ak,$T_{\\Omega ,\\alpha }^{{A_1},{A_2}, \\ldots ,{A_k}},$ which is a generalization of the higher-order commutator of the rough fractional integral on the generalized weighted Morrey spaces Mp,ϕ (w. We find the sufficient conditions on the pair (ϕ1, ϕ2 with w ∈ Ap,q which ensures the boundedness of the operators TΩ,αA1,A2,…,Ak,$T_{\\Omega ,\\alpha }^{{A_1},{A_2}, \\ldots ,{A_k}},$ from Mp,φ1wptoMp,φ2wq${M_{p,{\\varphi _1}}}\\left( {{w^p}} \\right\\,{\\rm{to}}\\,{M_{p,{\\varphi _2}}}\\left( {{w^q}} \\right$ for 1 < p < q < ∞. In all cases the conditions for the boundedness of the operator TΩ,αA1,A2,…,Ak,$T_{\\Omega ,\\alpha }^{{A_1},{A_2}, \\ldots ,{A_k}},$ are given in terms of Zygmund-type integral inequalities on (ϕ1, ϕ2 and w, which do not assume any assumption on monotonicity of ϕ1 (x,r, ϕ2(x, r in r.

14 CFR 29.29 - Empty weight and corresponding center of gravity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...

Pseudo-differential operators on manifolds with singularities

CERN Document Server

Schulze, B-W

1991-01-01

The analysis of differential equations in domains and on manifolds with singularities belongs to the main streams of recent developments in applied and pure mathematics. The applications and concrete models from engineering and physics are often classical but the modern structure calculus was only possible since the achievements of pseudo-differential operators. This led to deep connections with index theory, topology and mathematical physics. The present book is devoted to elliptic partial differential equations in the framework of pseudo-differential operators. The first chapter contains the Mellin pseudo-differential calculus on R+ and the functional analysis of weighted Sobolev spaces with discrete and continuous asymptotics. Chapter 2 is devoted to the analogous theory on manifolds with conical singularities, Chapter 3 to manifolds with edges. Employed are pseudo-differential operators along edges with cone-operator-valued symbols.

Necessary and Sufficient Conditions for Boundedness of Commutators of the General Fractional Integral Operators on Weighted Morrey Spaces

Directory of Open Access Journals (Sweden)

Zengyan Si

2012-01-01

Full Text Available We prove that b is in Lipβ(ω if and only if the commutator [b,L-α/2] of the multiplication operator by b and the general fractional integral operator L-α/2 is bounded from the weighted Morrey space Lp,k(ω to Lq,kq/p(ω1-(1-α/nq,ω, where 0(1-k/(p/(q-k, and here rω denotes the critical index of ω for the reverse Hölder condition.

On Weighted Support Vector Regression

DEFF Research Database (Denmark)

Han, Xixuan; Clemmensen, Line Katrine Harder

2014-01-01

We propose a new type of weighted support vector regression (SVR), motivated by modeling local dependencies in time and space in prediction of house prices. The classic weights of the weighted SVR are added to the slack variables in the objective function (OF‐weights). This procedure directly...... shrinks the coefficient of each observation in the estimated functions; thus, it is widely used for minimizing influence of outliers. We propose to additionally add weights to the slack variables in the constraints (CF‐weights) and call the combination of weights the doubly weighted SVR. We illustrate...... the differences and similarities of the two types of weights by demonstrating the connection between the Least Absolute Shrinkage and Selection Operator (LASSO) and the SVR. We show that an SVR problem can be transformed to a LASSO problem plus a linear constraint and a box constraint. We demonstrate...

THE WEIGHTED POINCARÉ DISTANCE IN THE HALF PLANE

OpenAIRE

Byun, Jisoo; Baek, Seung Min; Cho, Hong Rae; Lee, Han-Wool

2014-01-01

In this paper we introduce the weighted Poincaré distance and the induced distance by the weighted Bloch type space. We prove that the weighted Poincaré distance is identical to the inner distance generated by the induced distance.

Numerically Calculated 3D Space-Weighting Functions to Image Crustal Volcanic Structures Using Diffuse Coda Waves

Directory of Open Access Journals (Sweden)

Edoardo Del Pezzo

2018-05-01

Full Text Available Seismic coda measurements retrieve parameters linked to the physical characteristics of rock volumes illuminated by high frequency scattered waves. Space weighting functions (SWF and kernels are different tools that model the spatial sensitivity of coda envelopes to scattering and absorption anomalies in these rock matrices, allowing coda-wave attenuation ( Q c o d a imaging. This note clarifies the difference between SWF and sensitivity kernels developed for coda wave imaging. It extends the SWF previously developed in 2D to the third dimension by using radiative transfer and the diffusion equation, based on the assumption that variations of Q c o d a depend solely on variations of the extinction length. When applied to active data (Deception Island, Antarctica, 3D SWF images strongly resemble 2D images, making this 3D extension redundant. On the other hand, diffusion does not efficiently model coda waveforms when using earthquake datasets spanning depths between 0 and 20 km, such as at Mount St. Helens volcano. In this setting, scattering attenuation and absorption suffer tradeoffs and cannot be separated by fitting a single seismogram energy envelope for SWF imaging. We propose that an approximate analytical 3D SWF, similar in shape to the common coda kernels used in literature, can still be used in a space weighted back-projection approach. While Q c o d a is not a physical parameter of the propagation medium, its spatially-dependent modeling allows improved reconstruction of crustal-scale tectonic and geological features. It is even more efficient as a velocity independent imaging tool for magma and fluid storage when applied to deep volcanism.

Exploiting Molecular Weight Distribution Shape to Tune Domain Spacing in Block Copolymer Thin Films.

Science.gov (United States)

Gentekos, Dillon T; Jia, Junteng; Tirado, Erika S; Barteau, Katherine P; Smilgies, Detlef-M; DiStasio, Robert A; Fors, Brett P

2018-04-04

We report a method for tuning the domain spacing ( D sp ) of self-assembled block copolymer thin films of poly(styrene- block-methyl methacrylate) (PS- b-PMMA) over a large range of lamellar periods. By modifying the molecular weight distribution (MWD) shape (including both the breadth and skew) of the PS block via temporal control of polymer chain initiation in anionic polymerization, we observe increases of up to 41% in D sp for polymers with the same overall molecular weight ( M n ≈ 125 kg mol -1 ) without significantly changing the overall morphology or chemical composition of the final material. In conjunction with our experimental efforts, we have utilized concepts from population statistics and least-squares analysis to develop a model for predicting D sp based on the first three moments of the MWDs. This statistical model reproduces experimental D sp values with high fidelity (with mean absolute errors of 1.2 nm or 1.8%) and provides novel physical insight into the individual and collective roles played by the MWD moments in determining this property of interest. This work demonstrates that both MWD breadth and skew have a profound influence over D sp , thereby providing an experimental and conceptual platform for exploiting MWD shape as a simple and modular handle for fine-tuning D sp in block copolymer thin films.

Solution Theory of Ginzburg-Landau Theory on BCS-BEC Crossover

Directory of Open Access Journals (Sweden)

Shuhong Chen

2014-01-01

Full Text Available We establish strong solution theory of time-dependent Ginzburg-Landau (TDGL systems on BCS-BEC crossover. By the properties of Besov, Sobolev spaces, and Fourier functions and the method of bootstrapping argument, we deduce that the global existence of strong solutions to time-dependent Ginzburg-Landau systems on BCS-BEC crossover in various spatial dimensions.

Nonlinear anisotropic elliptic equations with variable exponents and degenerate coercivity

Directory of Open Access Journals (Sweden)

Hocine Ayadi

2018-02-01

Full Text Available In this article, we prove the existence and the regularity of distributional solutions for a class of nonlinear anisotropic elliptic equations with $p_i(x$ growth conditions, degenerate coercivity and $L^{m(\\cdot}$ data, with $m(\\cdot$ being small, in appropriate Lebesgue-Sobolev spaces with variable exponents. The obtained results extend some existing ones [8,10].

The Cauchy Problem for a Fifth-Order Dispersive Equation

OpenAIRE

Wang, Hongjun; Liu, Yongqi; Chen, Yongqiang

2014-01-01

This paper is devoted to studying the Cauchy problem for a fifth-order equation. We prove that it is locally well-posed for the initial data in the Sobolev space ${H}^{s}(\\mathbf{R})$ with $s\\ge 1/4$ . We also establish the ill-posedness for the initial data in ${H}^{s}(\\mathbf{R})$ with $s

Fractional Sobolev’s Spaces on Time Scales via Conformable Fractional Calculus and Their Application to a Fractional Differential Equation on Time Scales

Directory of Open Access Journals (Sweden)

Yanning Wang

2016-01-01

Full Text Available Using conformable fractional calculus on time scales, we first introduce fractional Sobolev spaces on time scales, characterize them, and define weak conformable fractional derivatives. Second, we prove the equivalence of some norms in the introduced spaces and derive their completeness, reflexivity, uniform convexity, and compactness of some imbeddings, which can be regarded as a novelty item. Then, as an application, we present a recent approach via variational methods and critical point theory to obtain the existence of solutions for a p-Laplacian conformable fractional differential equation boundary value problem on time scale T:  Tα(Tαup-2Tα(u(t=∇F(σ(t,u(σ(t, Δ-a.e.  t∈a,bTκ2, u(a-u(b=0, Tα(u(a-Tα(u(b=0, where Tα(u(t denotes the conformable fractional derivative of u of order α at t, σ is the forward jump operator, a,b∈T,  01, and F:[0,T]T×RN→R. By establishing a proper variational setting, we obtain three existence results. Finally, we present two examples to illustrate the feasibility and effectiveness of the existence results.

Small Valdivia compact spaces

CERN Document Server

Kubi's, W; Kubi\\'s, Wieslaw; Michalewski, Henryk

2005-01-01

We prove a preservation theorem for the class of Valdivia compact spaces, which involves inverse sequences of ``simple'' retractions. Consequently, a compact space of weight $\\loe\\aleph_1$ is Valdivia compact iff it is the limit of an inverse sequence of metric compacta whose bonding maps are retractions. As a corollary, we show that the class of Valdivia compacta of weight at most $\\aleph_1$ is preserved both under retractions and under open 0-dimensional images. Finally, we characterize the class of all Valdivia compacta in the language of category theory, which implies that this class is preserved under all continuous weight preserving functors.

The feature-weighted receptive field: an interpretable encoding model for complex feature spaces.

Science.gov (United States)

St-Yves, Ghislain; Naselaris, Thomas

2017-06-20

We introduce the feature-weighted receptive field (fwRF), an encoding model designed to balance expressiveness, interpretability and scalability. The fwRF is organized around the notion of a feature map-a transformation of visual stimuli into visual features that preserves the topology of visual space (but not necessarily the native resolution of the stimulus). The key assumption of the fwRF model is that activity in each voxel encodes variation in a spatially localized region across multiple feature maps. This region is fixed for all feature maps; however, the contribution of each feature map to voxel activity is weighted. Thus, the model has two separable sets of parameters: "where" parameters that characterize the location and extent of pooling over visual features, and "what" parameters that characterize tuning to visual features. The "where" parameters are analogous to classical receptive fields, while "what" parameters are analogous to classical tuning functions. By treating these as separable parameters, the fwRF model complexity is independent of the resolution of the underlying feature maps. This makes it possible to estimate models with thousands of high-resolution feature maps from relatively small amounts of data. Once a fwRF model has been estimated from data, spatial pooling and feature tuning can be read-off directly with no (or very little) additional post-processing or in-silico experimentation. We describe an optimization algorithm for estimating fwRF models from data acquired during standard visual neuroimaging experiments. We then demonstrate the model's application to two distinct sets of features: Gabor wavelets and features supplied by a deep convolutional neural network. We show that when Gabor feature maps are used, the fwRF model recovers receptive fields and spatial frequency tuning functions consistent with known organizational principles of the visual cortex. We also show that a fwRF model can be used to regress entire deep

Approximation of the eigenvalue problem for the time harmonic Maxwell system by continuous Lagrange finite elements

KAUST Repository

Bonito, Andrea; Guermond, Jean-Luc

2011-01-01

We propose and analyze an approximation technique for the Maxwell eigenvalue problem using H1-conforming finite elements. The key idea consists of considering a mixed method controlling the divergence of the electric field in a fractional Sobolev space H-α with α ∈ (1/2, 1). The method is shown to be convergent and spectrally correct. © 2011 American Mathematical Society.

Non-commutative Nash inequalities

International Nuclear Information System (INIS)

Kastoryano, Michael; Temme, Kristan

2016-01-01

A set of functional inequalities—called Nash inequalities—are introduced and analyzed in the context of quantum Markov process mixing. The basic theory of Nash inequalities is extended to the setting of non-commutative L p spaces, where their relationship to Poincaré and log-Sobolev inequalities is fleshed out. We prove Nash inequalities for a number of unital reversible semigroups

Non-linear analytic and coanalytic problems (Lp-theory, Clifford analysis, examples)

International Nuclear Information System (INIS)

Dubinskii, Yu A; Osipenko, A S

2000-01-01

Two kinds of new mathematical model of variational type are put forward: non-linear analytic and coanalytic problems. The formulation of these non-linear boundary-value problems is based on a decomposition of the complete scale of Sobolev spaces into the 'orthogonal' sum of analytic and coanalytic subspaces. A similar decomposition is considered in the framework of Clifford analysis. Explicit examples are presented

Non-linear analytic and coanalytic problems ( L_p-theory, Clifford analysis, examples)

Science.gov (United States)

Dubinskii, Yu A.; Osipenko, A. S.

2000-02-01

Two kinds of new mathematical model of variational type are put forward: non-linear analytic and coanalytic problems. The formulation of these non-linear boundary-value problems is based on a decomposition of the complete scale of Sobolev spaces into the "orthogonal" sum of analytic and coanalytic subspaces. A similar decomposition is considered in the framework of Clifford analysis. Explicit examples are presented.

hp Spectral element methods for three dimensional elliptic problems

Indian Academy of Sciences (India)

This is the first of a series of papers devoted to the study of h-p spec- .... element functions defined on mesh elements in the new system of variables with a uni- ... the spectral element functions on these elements and give construction of the stability .... By Hm( ), we denote the usual Sobolev space of integer order m ≥ 0 ...

Velocity-space sensitivity of neutron spectrometry measurements

DEFF Research Database (Denmark)

Jacobsen, Asger Schou; Salewski, Mirko; Eriksson, J.

2015-01-01

Neutron emission spectrometry (NES) measures the energies of neutrons produced in fusion reactions. Here we present velocity-space weight functions for NES and neutron yield measurements. Weight functions show the sensitivity as well as the accessible regions in velocity space for a given range...

14 CFR 25.29 - Empty weight and corresponding center of gravity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 27.29 - Empty weight and corresponding center of gravity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

Measure theory and fine properties of functions

CERN Document Server

Evans, Lawrence Craig

2015-01-01

Measure Theory and Fine Properties of Functions, Revised Edition provides a detailed examination of the central assertions of measure theory in n-dimensional Euclidean space. The book emphasizes the roles of Hausdorff measure and capacity in characterizing the fine properties of sets and functions. Topics covered include a quick review of abstract measure theory, theorems and differentiation in ℝn, Hausdorff measures, area and coarea formulas for Lipschitz mappings and related change-of-variable formulas, and Sobolev functions as well as functions of bounded variation.The text provides complete proofs of many key results omitted from other books, including Besicovitch's covering theorem, Rademacher's theorem (on the differentiability a.e. of Lipschitz functions), area and coarea formulas, the precise structure of Sobolev and BV functions, the precise structure of sets of finite perimeter, and Aleksandrov's theorem (on the twice differentiability a.e. of convex functions).This revised edition includes countl...

Disjoint hypercyclicity of weighted composition operators

Indian Academy of Sciences (India)

Hypercyclicity; supercyclicity; disjoint hypercyclicity; disjoint super- cyclicity; weighted composition operators; Hilbert space. 2010 Mathematics Subject Classification. 47A16, 47B33, 47B38. 1. Introduction. Let X be a topological vector space and T a bounded linear operator on X. The T-orbit of a vector x ∈ X is the set. O(x,T) ...

Bessel Weighted Asymmetries

Energy Technology Data Exchange (ETDEWEB)

Avakian, Harut [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Gamberg, Leonard [Pennsylvania State Univ., University Park, PA (United States); Rossi, Patrizia [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Prokudin, Alexei [Pennsylvania State Univ., University Park, PA (United States)

2016-05-01

We review the concept of Bessel weighted asymmetries for semi-inclusive deep inelastic scattering and focus on the cross section in Fourier space, conjugate to the outgoing hadron’s transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. The procedure is applied to studies of the double longitudinal spin asymmetry in semi-inclusive deep inelastic scattering using a new dedicated Monte Carlo generator which includes quark intrinsic transverse momentum within the generalized parton model. We observe a few percent systematic offset of the Bessel-weighted asymmetry obtained from Monte Carlo extraction compared to input model calculations, which is due to the limitations imposed by the energy and momentum conservation at the given energy and hard scale Q2. We find that the Bessel weighting technique provides a powerful and reliable tool to study the Fourier transform of TMDs with controlled systematics due to experimental acceptances and resolutions with different TMD model inputs.

The S-Transform on Hardy Spaces and Its Duals

Directory of Open Access Journals (Sweden)

Sunil Kumar Singh

2015-03-01

Full Text Available In this paper, continuity and boundedness results for the continuous S-transform in BMO and Hardy spaces are obtained. Furthermore, the continuous S-transform is also studied on the weighted BMO$_k$ and weighted Hardy spaces associated with a tempered weight function which was proposed by L. H\\"ormander in the study of the theory of partial differential equations.

Ergonomic Evaluation of Space Shuttle Light-Weight Seat Lever Position and Operation

Science.gov (United States)

Maida, J.; Rajulu, Sudhakar L.; Bond, Robert L. (Technical Monitor)

2000-01-01

During a Shuttle flight in the early part of 1999, one of the crewmembers was unable to operate the backrest lever for the light-weight seat in microgravity. It is essential that the crewmembers are able to adjust this back-rest lever, which is titled forward 2 degrees from vertical during launch and then moved backwards to 10 degrees aft of vertical upon reaching orbit. This adjustment is needed to cushion the crewmembers during an inadvertent crash landing situation. The original Shuttle seats, which had seat controls located on the front left and right sides of the seat, were replaced recently with the new light-weight seats. The controls for these new, seats were moved to the night side with one control at the front and the other at the back. While it was uncertain whether the problem encountered was unique to that crewmember or not it was clear to the personnel responsible for maintaining the Shuttle seats that not knowing the cause of the problem posed a safety concern for NASA. Hence the Anthropometry and Biomechanics Facility (ABF) of the Johnson Space Center was requested to perform an evaluation of the seat controls and provide NASA with appropriate recommendations on whether the seat lever positions and operations should be modified. The ABF designed an experiment to investigate the amount of pull force exerted by subjects, wearing an unpressurized or pressurized crew launch escape suit, when controls were placed in the front and back (on the right side) of the light-weight seat. Single-axis load cells were attached to the seat levers, which measured the maximum static pull forces that were exerted by the subjects. Twelve subjects, six male and six female, participated in this study. Each subject was asked to perform the pull test at least three times for each combination of lever position and suit pressure conditions. The results from this study showed that as a whole (or in general), the subjects were able to pull on the lever at the back position with

An introduction to the mathematical theory of finite elements

CERN Document Server

Oden, J T

2011-01-01

This introduction to the theory of Sobolev spaces and Hilbert space methods in partial differential equations is geared toward readers of modest mathematical backgrounds. It offers coherent, accessible demonstrations of the use of these techniques in developing the foundations of the theory of finite element approximations.J. T. Oden is Director of the Institute for Computational Engineering & Sciences (ICES) at the University of Texas at Austin, and J. N. Reddy is a Professor of Engineering at Texas A&M University. They developed this essentially self-contained text from their seminars and co

Pro-torus actions on Poincaré duality spaces

Indian Academy of Sciences (India)

duality spaces, Borel's dimension formula and topological splitting principle to local weights, hold if 'torus' is replaced by 'pro-torus'. Keywords. Pro-torus; Poincaré duality space; local weight. 1. Introduction. In the theory of linear representations of compact connected Lie groups, the crucial first step is restriction to the ...

Neighbourhood Influences on Children's Weight-related Behaviours and Body Mass Index.

Science.gov (United States)

Jenkin, Gabrielle L; Pearson, Amber L; Bentham, Graham; Day, Peter; Kingham, Simon

2015-01-01

Neighbourhood contextual factors such as accessibility of food shops and green spaces are associated with adult bodyweight but not necessarily weight-related behaviours. Whether these associations are replicated amongst children is unknown. To understand which aspects of childrens' neighbourhoods are associated with unhealthy weight and weight-related behaviours. Individual-level data for children from the 2006/7 New Zealand Health Survey (of Body Mass Index (BMI), dietary indicators and socioeconomic variables) were linked with geographic level data on neighbourhood deprivation, rural/urban status, percentage of community engaged in active travel, access to green space, food shops and sports/leisure facilities. Logistic regression models were fitted for measures of BMI and weight-related behaviours; sugar sweetened beverage (SSB) consumption; fast-food consumption; and television viewing. Increased community engagement in active transport was, counterintuitively, the only neighbourhood contextual factor associated with unhealthy weight amongst children. After adjustment for socioeconomic and environmental variables, greater access to green space appeared to have a protective effect on SSB consumption and neighbourhood deprivation was associated with all three unhealthy weight-related behaviours (SSB and fast-food consumption and television viewing). Although further research is needed, evidence from the current study suggests that a repertoire of health promotion interventions and policies to change unhealthy weight-related behaviours in high deprivation neighbourhoods may be required to address childhood obesity.

An Advanced Light Weight Recuperator for Space Power Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Nuclear Electric Propulsion (NEP) technology holds great promise for power and propulsion demands of NASA current and future deep space explorations. Closed Brayton...

Moduli of weighted hyperplane arrangements

CERN Document Server

Lahoz, Martí; Macrí, Emanuele; Stellari, Paolo

2015-01-01

This book focuses on a large class of geometric objects in moduli theory and provides explicit computations to investigate their families. Concrete examples are developed that take advantage of the intricate interplay between Algebraic Geometry and Combinatorics. Compactifications of moduli spaces play a crucial role in Number Theory, String Theory, and Quantum Field Theory – to mention just a few. In particular, the notion of compactification of moduli spaces has been crucial for solving various open problems and long-standing conjectures. Further, the book reports on compactification techniques for moduli spaces in a large class where computations are possible, namely that of weighted stable hyperplane arrangements.

An Advanced Light Weight Recuperator for Space Power Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Closed Brayton Cycle (CBC) space power system is one of the most efficient energy conversion technologies for nuclear and solar electric propulsion. The recuperator...

Salt-body Inversion with Minimum Gradient Support and Sobolev Space Norm Regularizations

KAUST Repository

Kazei, Vladimir; Kalita, Mahesh; Alkhalifah, Tariq Ali

2017-01-01

propagation of arbitrary complexity (visco-elastic, anisotropic); yet, it often fails to retrieve high-contrast geological structures, such as salt. One of the reasons for the FWI failure is that the updates at earlier iterations are too smooth to capture

Global solutions in lower order Sobolev spaces for the generalized Boussinesq equation

Directory of Open Access Journals (Sweden)

Luiz G. Farah

2012-03-01

Full Text Available We show that the Cauchy problem for the defocusing generalized Boussinesq equation $$ u_{tt}-u_{xx}+u_{xxxx}-(|u|^{2k}u_{xx}=0, quad kgeq 1, $$ on the real line is globally well-posed in $H^s(mathbb{R}$ with s>1-(1/(3k. To do this, we use the I-method, introduced by Colliander, Keel, Staffilani, Takaoka and Tao [8,9], to define a modification of the energy functional that is almost conserved in time. Our result extends a previous result obtained by Farah and Linares [16] for the case k=1.

Associations among q-space MRI, diffusion-weighted MRI and histopathological parameters in meningiomas

Energy Technology Data Exchange (ETDEWEB)

Fatima, Zareen; Motosugi, Utaroh; Ishigame, Keiichi; Araki, Tsutomu [University of Yamanashi, Department of Radiology, Chuo-shi, Yamanashi (Japan); Waqar, Ahmed Bilal [University of Yamanashi, Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, Chuo-shi, Yamanashi (Japan); Hori, Masaaki [Juntendo University, Department of Radiology, School of Medicine, Tokyo (Japan); Oishi, Naoki; Katoh, Ryohei [University of Yamanashi, Department of Pathology, Chuo-shi, Yamanashi (Japan); Onodera, Toshiyuki; Yagi, Kazuo [Tokyo Metropolitan University, Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo (Japan)

2013-08-15

The purposes of this MR-based study were to calculate q-space imaging (QSI)-derived mean displacement (MDP) in meningiomas, to evaluate the correlation of MDP values with apparent diffusion coefficient (ADC) and to investigate the relationships among these diffusion parameters, tumour cell count (TCC) and MIB-1 labelling index (LI). MRI, including QSI and conventional diffusion-weighted imaging (DWI), was performed in 44 meningioma patients (52 lesions). ADC and MDP maps were acquired from post-processing of the data. Quantitative analyses of these maps were performed by applying regions of interest. Pearson correlation coefficients were calculated for ADC and MDP in all lesions and for ADC and TCC, MDP and TCC, ADC and MIB-1 LI, and MDP and MIB-1 LI in 17 patients who underwent subsequent surgery. ADC and MDP values were found to have a strong correlation: r = 0.78 (P = <0.0001). Both ADC and MDP values had a significant negative association with TCC: r = -0.53 (p = 0.02) and -0.48 (P = 0.04), respectively. MIB-1 LI was not, however, found to have a significant association with these diffusion parameters. In meningiomas, both ADC and MDP may be representative of cell density. (orig.)

Associations among q-space MRI, diffusion-weighted MRI and histopathological parameters in meningiomas

International Nuclear Information System (INIS)

Fatima, Zareen; Motosugi, Utaroh; Ishigame, Keiichi; Araki, Tsutomu; Waqar, Ahmed Bilal; Hori, Masaaki; Oishi, Naoki; Katoh, Ryohei; Onodera, Toshiyuki; Yagi, Kazuo

2013-01-01

The purposes of this MR-based study were to calculate q-space imaging (QSI)-derived mean displacement (MDP) in meningiomas, to evaluate the correlation of MDP values with apparent diffusion coefficient (ADC) and to investigate the relationships among these diffusion parameters, tumour cell count (TCC) and MIB-1 labelling index (LI). MRI, including QSI and conventional diffusion-weighted imaging (DWI), was performed in 44 meningioma patients (52 lesions). ADC and MDP maps were acquired from post-processing of the data. Quantitative analyses of these maps were performed by applying regions of interest. Pearson correlation coefficients were calculated for ADC and MDP in all lesions and for ADC and TCC, MDP and TCC, ADC and MIB-1 LI, and MDP and MIB-1 LI in 17 patients who underwent subsequent surgery. ADC and MDP values were found to have a strong correlation: r = 0.78 (P = <0.0001). Both ADC and MDP values had a significant negative association with TCC: r = -0.53 (p = 0.02) and -0.48 (P = 0.04), respectively. MIB-1 LI was not, however, found to have a significant association with these diffusion parameters. In meningiomas, both ADC and MDP may be representative of cell density. (orig.)

Uus kunstikool näitab oma nägu ja hambaid / Karen Jagodin

Index Scriptorium Estoniae

Jagodin, Karen, 1982-

2004-01-01

Positivistliku Kunsttööstuskooli kampaaniapäevad algasid Performance Week'iga Ku galeriis. Avamisel esines Mari Sobolev performance'iga "Lost in the system". Kampaaniapäevad kulmineeruvad Paide tegevuskunstifestivaliga "Aeg. Ruum. Liikumine: unplugged". Festivali kuraator on Mari Sobolev

Weighted estimates for the averaging integral operator

Czech Academy of Sciences Publication Activity Database

Opic, Bohumír; Rákosník, Jiří

2010-01-01

Roč. 61, č. 3 (2010), s. 253-262 ISSN 0010-0757 R&D Projects: GA ČR GA201/05/2033; GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : averaging integral operator * weighted Lebesgue spaces * weights Subject RIV: BA - General Mathematics Impact factor: 0.474, year: 2010 http://link.springer.com/article/10.1007%2FBF03191231

Structural Weight Estimation for Launch Vehicles

Science.gov (United States)

Cerro, Jeff; Martinovic, Zoran; Su, Philip; Eldred, Lloyd

2002-01-01

This paper describes some of the work in progress to develop automated structural weight estimation procedures within the Vehicle Analysis Branch (VAB) of the NASA Langley Research Center. One task of the VAB is to perform system studies at the conceptual and early preliminary design stages on launch vehicles and in-space transportation systems. Some examples of these studies for Earth to Orbit (ETO) systems are the Future Space Transportation System [1], Orbit On Demand Vehicle [2], Venture Star [3], and the Personnel Rescue Vehicle[4]. Structural weight calculation for launch vehicle studies can exist on several levels of fidelity. Typically historically based weight equations are used in a vehicle sizing program. Many of the studies in the vehicle analysis branch have been enhanced in terms of structural weight fraction prediction by utilizing some level of off-line structural analysis to incorporate material property, load intensity, and configuration effects which may not be captured by the historical weight equations. Modification of Mass Estimating Relationships (MER's) to assess design and technology impacts on vehicle performance are necessary to prioritize design and technology development decisions. Modern CAD/CAE software, ever increasing computational power and platform independent computer programming languages such as JAVA provide new means to create greater depth of analysis tools which can be included into the conceptual design phase of launch vehicle development. Commercial framework computing environments provide easy to program techniques which coordinate and implement the flow of data in a distributed heterogeneous computing environment. It is the intent of this paper to present a process in development at NASA LaRC for enhanced structural weight estimation using this state of the art computational power.

Challenges in Teaching Space Physics to Different Target Groups From Space Weather Forecasters to Heavy-weight Theorists

Science.gov (United States)

Koskinen, H. E.

2008-12-01

Plasma physics as the backbone of space physics is difficult and thus the space physics students need to have strong foundations in general physics, in particular in classical electrodynamics and thermodynamics, and master the basic mathematical tools for physicists. In many universities the number of students specializing in space physics at Master's and Doctoral levels is rather small and the students may have quite different preferences ranging from experimental approach to hard-core space plasma theory. This poses challenges in building up a study program that has both the variety and depth needed to motivate the best students to choose this field. At the University of Helsinki we require all beginning space physics students, regardless whether they enter the field as Master's or Doctoral degree students, to take a one-semester package consisting of plasma physics and its space applications. However, some compromises are necessary. For example, it is not at all clear, how thoroughly Landau damping should be taught at the first run or how deeply should the intricacies of collisionless reconnection be discussed. In both cases we have left the details to an optional course in advanced space physics, even with the risk that the student's appreciation of, e.g., reconnection may remain at the level of a magic wand. For learning experimental work, data analysis or computer simulations we have actively pursued arrangements for the Master's degree students to get a summer employments in active research groups, which usually lead to the Master's theses. All doctoral students are members of research groups and participate in experimental work, data analysis, simulation studies or theory development, or any combination of these. We emphasize strongly "learning by doing" all the way from the weekly home exercises during the lecture courses to the PhD theses which in Finland consist typically of 4-6 peer-reviewed articles with a comprehensive introductory part.

Embeddings between weighted Copson and Cesaro function spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Mustafayev, R.Ch.; Ünver, T.

2017-01-01

Roč. 67, č. 4 (2017), s. 1005-1132 ISSN 0011-4642 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : Cesaro and Copson function spaces * embedding * iterated Hardy inequalities Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.364, year: 2016 https://link.springer.com/article/10.21136/CMJ.2017.0424-16

Pseudo-Riemannian VSI spaces

International Nuclear Information System (INIS)

Hervik, Sigbjoern; Coley, Alan

2011-01-01

In this paper we consider pseudo-Riemannian spaces of arbitrary signature for which all of the polynomial curvature invariants vanish (VSI spaces). We discuss an algebraic classification of pseudo-Riemannian spaces in terms of the boost weight decomposition and define the S i - and N-properties, and show that if the curvature tensors of the space possess the N-property, then it is a VSI space. We then use this result to construct a set of metrics that are VSI. All of the VSI spaces constructed possess a geodesic, expansion-free, shear-free, and twist-free null congruence. We also discuss the related Walker metrics.

Pseudo-Riemannian VSI spaces

Energy Technology Data Exchange (ETDEWEB)

Hervik, Sigbjoern [Faculty of Science and Technology, University of Stavanger, N-4036 Stavanger (Norway); Coley, Alan, E-mail: sigbjorn.hervik@uis.no, E-mail: aac@mathstat.dal.ca [Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia B3H 3J5 (Canada)

2011-01-07

In this paper we consider pseudo-Riemannian spaces of arbitrary signature for which all of the polynomial curvature invariants vanish (VSI spaces). We discuss an algebraic classification of pseudo-Riemannian spaces in terms of the boost weight decomposition and define the S{sub i}- and N-properties, and show that if the curvature tensors of the space possess the N-property, then it is a VSI space. We then use this result to construct a set of metrics that are VSI. All of the VSI spaces constructed possess a geodesic, expansion-free, shear-free, and twist-free null congruence. We also discuss the related Walker metrics.

Weak convergence of Jacobian determinants under asymmetric assumptions

Directory of Open Access Journals (Sweden)

Teresa Alberico

2012-05-01

Full Text Available Let $\\Om$ be a bounded open set in $\\R^2$ sufficiently smooth and $f_k=(u_k,v_k$ and $f=(u,v$ mappings belong to the Sobolev space $W^{1,2}(\\Om,\\R^2$. We prove that if the sequence of Jacobians $J_{f_k}$ converges to a measure $\\mu$ in sense of measures andif one allows different assumptions on the two components of $f_k$ and $f$, e.g.$$u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,2}(\\Om \\qquad \\, v_k \\rightharpoonup v \\;\\;\\mbox{weakly in} \\;\\; W^{1,q}(\\Om$$for some $q\\in(1,2$, then\\begin{equation}\\label{0}d\\mu=J_f\\,dz.\\end{equation}Moreover, we show that this result is optimal in the sense that conclusion fails for $q=1$.On the other hand, we prove that \\eqref{0} remains valid also if one considers the case $q=1$, but it is necessary to require that $u_k$ weakly converges to $u$ in a Zygmund-Sobolev space with a slightly higher degree of regularity than $W^{1,2}(\\Om$ and precisely$$ u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,L^2 \\log^\\alpha L}(\\Om$$for some $\\alpha >1$.    

The theory of pseudo-differential operators on the noncommutative n-torus

Science.gov (United States)

Tao, J.

2018-02-01

The methods of spectral geometry are useful for investigating the metric aspects of noncommutative geometry and in these contexts require extensive use of pseudo-differential operators. In a foundational paper, Connes showed that, by direct analogy with the theory of pseudo-differential operators on finite-dimensional real vector spaces, one may derive a similar pseudo-differential calculus on noncommutative n-tori, and with the development of this calculus came many results concerning the local differential geometry of noncommutative tori for n=2,4, as shown in the groundbreaking paper in which the Gauss-Bonnet theorem on the noncommutative two-torus is proved and later papers. Certain details of the proofs in the original derivation of the calculus were omitted, such as the evaluation of oscillatory integrals, so we make it the objective of this paper to fill in all the details. After reproving in more detail the formula for the symbol of the adjoint of a pseudo-differential operator and the formula for the symbol of a product of two pseudo-differential operators, we extend these results to finitely generated projective right modules over the noncommutative n-torus. Then we define the corresponding analog of Sobolev spaces and prove equivalents of the Sobolev and Rellich lemmas.

Approximation by modified Szasz–Mirakjan operators on weighted ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

English translation in Math. Notes 20(5–6) (1976) 996–998. [3] Gadzhiev A D, Positive linear operators in weighted spaces of functions of several vari- ables, Izv. Akad. Nauk. SSR Ser. Fiz-Tekhn. Math. Nauk 4 (1980) 32–37. [4] Gadzhiev A D, Weighted approximation of continuous functions by linear operators on the whole ...

14 CFR 25.523 - Design weights and center of gravity positions.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Design weights and center of gravity... Design weights and center of gravity positions. (a) Design weights. The water load requirements must be...) must be used. (b) Center of gravity positions. The critical centers of gravity within the limits for...

Neighbourhood Influences on Children’s Weight-related Behaviours and Body Mass Index

Directory of Open Access Journals (Sweden)

Gabrielle L. Jenkin

2015-08-01

Full Text Available Introduction: Neighbourhood contextual factors such as accessibility of food shops and green spaces are associated with adult bodyweight but not necessarily weight-related behaviours. Whether these associations are replicated amongst children is unknown.Aim: To understand which aspects of childrens' neighbourhoods are associated with unhealthy weight and weight-related behaviours.Methods: Individual-level data for children from the 2006/7 New Zealand Health Survey (of Body Mass Index (BMI, dietary indicators and socioeconomic variables were linked with geographic level data on neighbourhood deprivation, rural/urban status, percentage of community engaged in active travel, access to green space, food shops and sports/leisure facilities. Logistic regression models were fitted for measures of BMI and weight-related behaviours; sugar sweetened beverage (SSB consumption; fast-food consumption; and television viewing. Results:Increased Ccommunity engagement in active transport was, counterintuitively, the only neighbourhood contextual factor associated with unhealthy weight amongst children. After adjustment for socioeconomic and environmental variables, greater access to green space appeared to have a protective effect on SSB consumption and neighbourhood deprivation was associated with all three unhealthy weight-related behaviours (SSB and fast-food consumption and television viewing. Conclusions: Although further research is needed, evidence from the current study suggests that a repertoire of health promotion interventions and policies to change unhealthy weight- related behaviours in high deprivation neighbourhoods may be required to address childhood obesity.

Thresholding projection estimators in functional linear models

OpenAIRE

Cardot, Hervé; Johannes, Jan

2010-01-01

We consider the problem of estimating the regression function in functional linear regression models by proposing a new type of projection estimators which combine dimension reduction and thresholding. The introduction of a threshold rule allows to get consistency under broad assumptions as well as minimax rates of convergence under additional regularity hypotheses. We also consider the particular case of Sobolev spaces generated by the trigonometric basis which permits to get easily mean squ...

B-spline goal-oriented error estimators for geometrically nonlinear rods

Science.gov (United States)

2011-04-01

respectively, for the output functionals q2–q4 (linear and nonlinear with the trigonometric functions sine and cosine) in all the tests considered...of the errors resulting from the linear, quadratic and nonlinear (with trigonometric functions sine and cosine) outputs and for p = 1, 2. If the... Portugal . References [1] A.T. Adams. Sobolev Spaces. Academic Press, Boston, 1975. [2] M. Ainsworth and J.T. Oden. A posteriori error estimation in

14 CFR 23.523 - Design weights and center of gravity positions.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Design weights and center of gravity... Structure Water Loads § 23.523 Design weights and center of gravity positions. (a) Design weights. The water... water taxi and takeoff run) must be used. (b) Center of gravity positions. The critical centers of...

Selecting a pharmacy layout design using a weighted scoring system.

Science.gov (United States)

McDowell, Alissa L; Huang, Yu-Li

2012-05-01

A weighted scoring system was used to select a pharmacy layout redesign. Facilities layout design techniques were applied at a local hospital pharmacy using a step-by-step design process. The process involved observing and analyzing the current situation, observing the current available space, completing activity flow charts of the pharmacy processes, completing communication and material relationship charts to detail which areas in the pharmacy were related to one another and how they were related, researching applications in other pharmacies or in scholarly works that could be beneficial, numerically defining space requirements for areas within the pharmacy, measuring the available space within the pharmacy, developing a set of preliminary designs, and modifying preliminary designs so they were all acceptable to the pharmacy staff. To select a final layout that could be implemented in the pharmacy, those layouts were compared via a weighted scoring system. The weighted aspect further allowed additional emphasis on categories based on their effect on pharmacy performance. The results produced a beneficial layout design as determined through simulated models of the pharmacy operation that more effectively allocated and strategically located space to improve transportation distances and materials handling, employee utilization, and ergonomics. Facilities layout designs for a hospital pharmacy were evaluated using a weighted scoring system to identify a design that was superior to both the current layout and alternative layouts in terms of feasibility, cost, patient safety, employee safety, flexibility, robustness, transportation distance, employee utilization, objective adherence, maintainability, usability, and environmental impact.

q-Space Upsampling Using x-q Space Regularization.

Science.gov (United States)

Chen, Geng; Dong, Bin; Zhang, Yong; Shen, Dinggang; Yap, Pew-Thian

2017-09-01

Acquisition time in diffusion MRI increases with the number of diffusion-weighted images that need to be acquired. Particularly in clinical settings, scan time is limited and only a sparse coverage of the vast q -space is possible. In this paper, we show how non-local self-similar information in the x - q space of diffusion MRI data can be harnessed for q -space upsampling. More specifically, we establish the relationships between signal measurements in x - q space using a patch matching mechanism that caters to unstructured data. We then encode these relationships in a graph and use it to regularize an inverse problem associated with recovering a high q -space resolution dataset from its low-resolution counterpart. Experimental results indicate that the high-resolution datasets reconstructed using the proposed method exhibit greater quality, both quantitatively and qualitatively, than those obtained using conventional methods, such as interpolation using spherical radial basis functions (SRBFs).

Geometric Spanners for Weighted Point Sets

DEFF Research Database (Denmark)

Abam, Mohammad; de Berg, Mark; Farshi, Mohammad

2009-01-01

Let (S,d) be a finite metric space, where each element p ∈ S has a non-negative weight w(p). We study spanners for the set S with respect to weighted distance function d w , where d w (p,q) is w(p) + d(p,q) + wq if p ≠ q and 0 otherwise. We present a general method for turning spanners with respect...... to the d-metric into spanners with respect to the d w -metric. For any given ε> 0, we can apply our method to obtain (5 + ε)-spanners with a linear number of edges for three cases: points in Euclidean space ℝ d , points in spaces of bounded doubling dimension, and points on the boundary of a convex body...... in ℝ d where d is the geodesic distance function. We also describe an alternative method that leads to (2 + ε)-spanners for points in ℝ d and for points on the boundary of a convex body in ℝ d . The number of edges in these spanners is O(nlogn). This bound on the stretch factor is nearly optimal...

Discrete Weighted Pseudo-Almost Automorphy and Applications

Directory of Open Access Journals (Sweden)

Zhinan Xia

2014-01-01

Full Text Available We deal with discrete weighted pseudo almost automorphy which extends some classical concepts and systematically explore its properties in Banach space including a composition result. As an application, we establish some sufficient criteria for the existence and uniqueness of the discrete weighted pseudo almost automorphic solutions to the Volterra difference equations of convolution type and also to nonautonomous semilinear difference equations. Some examples are presented to illustrate the main findings.

High Chamber Pressure, Light Weight Thrusters, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The performance liquid propellant engines can be significantly improved by increasing both combustion temperature and pressure and reducing engine weight. State of...

14 CFR 91.605 - Transport category civil airplane weight limitations.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Transport category civil airplane weight... civil airplane weight limitations. (a) No person may take off any transport category airplane (other than a turbine-engine-powered airplane certificated after September 30, 1958) unless— (1) The takeoff...

Malaria has no effect on birth weight in Rwanda

Directory of Open Access Journals (Sweden)

Karema Corine

2009-08-01

Full Text Available Abstract Background Malaria has a negative effect on pregnancy outcome, causing low birth weight, premature birth and stillbirths, particularly in areas with high malaria transmission. In Rwanda, malaria transmission intensity ranges from high to nil, probably associated with variable altitudes. Overall, the incidence decreased over the last six years (2002–2007. Therefore, the impact of malaria on birth outcomes is also expected to vary over time and space. Methods Obstetric indicators (birth weight and pregnancy outcome and malaria incidence were compared and analyzed to their association over time (2002–2007 and space. Birth data from 12,526 deliveries were collected from maternity registers of 11 different primary health centers located in different malaria endemic areas. Malaria data for the same communities were collected from the National Malaria Control Programme. Associations were sought with mixed effects models and logistic regression. Results In all health centres, a significant increase of birth weight over the years was observed (p Conclusion In Rwanda, birth weight and pregnancy outcome are not directly influenced by malaria, which is in contrast to many other studied areas. Although malaria incidence overall has declined and mean birth weight increased over the studied period, no direct association was found between the two. Socio-economic factors and improved nutrition could be responsible for birth weight changes in recent years.

3D Weight Matrices in Modeling Real Estate Prices

Science.gov (United States)

Mimis, A.

2016-10-01

Central role in spatial econometric models of real estate data has the definition of the weight matrix by which we capture the spatial dependence between the observations. The weight matrices presented in literature so far, treats space in a two dimensional manner leaving out the effect of the third dimension or in our case the difference in height where the property resides. To overcome this, we propose a new definition of the weight matrix including the third dimensional effect by using the Hadamard product. The results illustrated that the level effect can be absorbed into the new weight matrix.

Applied functional analysis

CERN Document Server

Oden, J Tinsley

2010-01-01

The textbook is designed to drive a crash course for beginning graduate students majoring in something besides mathematics, introducing mathematical foundations that lead to classical results in functional analysis. More specifically, Oden and Demkowicz want to prepare students to learn the variational theory of partial differential equations, distributions, and Sobolev spaces and numerical analysis with an emphasis on finite element methods. The 1996 first edition has been used in a rather intensive two-semester course. -Book News, June 2010

22. IV avati Berliini Kunstiülikooli galeriis näitus "Alle Gegen Alles"

Index Scriptorium Estoniae

2004-01-01

Osalevad Avangard, Raul Meel, Puhas Rõõm, Mare Tralla, Non Grata, Jaan Toomik, FLY, Erki Kasemets, Marliis Newsome, Tuupolev, Bille Neeve, Tuuliki Avango, Pink Punk, Egle Vesk, Raoul Kurvitz, Gert Hatsukov, Minna Hint ja Enn Tegova. Mari Sobolev pidas loengu eesti performance'i ajaloost ning Non Grata esitles oma töid. Valmistatakse ette Eesti Kunstiakadeemia ja Berliini Kunstiülikooli koostöö lepingut. 23. IV Open Space'i galeriis Taje Trossi kureeritud "Live Performance Nacht"

On velocity-space sensitivity of fast-ion D-alpha spectroscopy

DEFF Research Database (Denmark)

Salewski, Mirko; Geiger, B.; Moseev, Dmitry

2014-01-01

The velocity-space observation regions and sensitivities in fast-ion Dα (FIDA) spectroscopy measurements are often described by so-called weight functions. Here we derive expressions for FIDA weight functions accounting for the Doppler shift, Stark splitting, and the charge-exchange reaction...... and electron transition probabilities. Our approach yields an efficient way to calculate correctly scaled FIDA weight functions and implies simple analytic expressions for their boundaries that separate the triangular observable regions in (v‖, v⊥)-space from the unobservable regions. These boundaries...

Microwave Materials Processing for Space Applications, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — For a space-based fabrication effort to be effective, the weight, power requirements and footprint must be minimized. Because of the unique beam forming properties...

Embeddings of Lorentz-type spaces involving weighted integral means

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Křepela, M.; Pick, L.; Soudský, F.

2017-01-01

Roč. 273, č. 9 (2017), s. 2939-2980 ISSN 0022-1236 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : classical Lorentz spaces * embeddings * iterated operators Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.254, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022123617302252

Lightweight Space Tug body structure

International Nuclear Information System (INIS)

Lager, J.R.

1976-01-01

Lightweight honeycomb sandwich construction using a wide variety of metal and fibrous composite faceskins was used in the design of a typical Space Tug skirt structure. Relatively low magnitude combined loading of axial compression and torsion resulted in designs using ultrathin faceskins, light-weight honeycomb cores, and thin faceskin/core adhesive bond layers. Two of the designs with metal faceskins (aluminum and titanium) and four with fibrous composite faceskins (using combinations of fiberglass, boron, and graphite) were evaluated through the fabrication and structural test of a series of small development panels. The two most promising concepts with aluminum and graphite/epoxy faceskins, were further evaluated through the fabrication and structural test of larger compression and shear panels. All panels tested exceeded design ultimate load levels, thereby, verifying the structural integrity of the selected designs. Projected skirt structural weights for the graphite/epoxy and aluminum concepts fall within original weight guidelines established for the Space Tug vehicle

14 CFR 23.29 - Empty weight and corresponding center of gravity.

Science.gov (United States)

2010-01-01

... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...

Development of III-V/Si Multijunction Space Photovoltaics

Data.gov (United States)

National Aeronautics and Space Administration — High substrate costs, as well as weight, typically play a major role in the high costs of multijunction space solar cell production and deployment. III-V/Si...

Light-weight Self-correcting Inflatable/rigidizable Space Antennas, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The NASA/L'Garde Inflatable Antenna Experiment (IAE)flown in STS-77 has showed the potential of this class of structures in significantly reducing the costs for...

Thermal management of space stations

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Thermal management aims at making full use of energy resources available in the space station to reduce energy consumption, waste heat rejection and the weight of the station. It is an extension of the thermal control. This discussion introduces the concept and development of thermal management, presents the aspects of thermal management and further extends its application to subsystems of the space station.

Periodicity and positivity of a class of fractional differential equations.

Science.gov (United States)

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

2016-01-01

Fractional differential equations have been discussed in this study. We utilize the Riemann-Liouville fractional calculus to implement it within the generalization of the well known class of differential equations. The Rayleigh differential equation has been generalized of fractional second order. The existence of periodic and positive outcome is established in a new method. The solution is described in a fractional periodic Sobolev space. Positivity of outcomes is considered under certain requirements. We develop and extend some recent works. An example is constructed.

Theoretical numerical analysis a functional analysis framework

CERN Document Server

Atkinson, Kendall

2005-01-01

This textbook prepares graduate students for research in numerical analysis/computational mathematics by giving to them a mathematical framework embedded in functional analysis and focused on numerical analysis. This helps the student to move rapidly into a research program. The text covers basic results of functional analysis, approximation theory, Fourier analysis and wavelets, iteration methods for nonlinear equations, finite difference methods, Sobolev spaces and weak formulations of boundary value problems, finite element methods, elliptic variational inequalities and their numerical solu

On nonlinear evolution variational inequalities involving variable exponent

Directory of Open Access Journals (Sweden)

Mingqi Xiang

2013-12-01

Full Text Available In this paper, we discuss a class of quasilinear evolution variational inequalities with variable exponent growth conditions in a generalized Sobolev space. We obtain the existence of weak solutions by means of penalty method. Moreover, we study the extinction properties of weak solutions to parabolic inequalities and provide a sufficient condition that makes the weak solutions vanish in a finite time. The existence of global attractors for weak solutions is also obtained via the theories of multi-valued semiflow.

Elliptic boundary value problems with fractional regularity data the first order approach

CERN Document Server

Amenta, Alex

2018-01-01

In this monograph the authors study the well-posedness of boundary value problems of Dirichlet and Neumann type for elliptic systems on the upper half-space with coefficients independent of the transversal variable and with boundary data in fractional Hardy-Sobolev and Besov spaces. The authors use the so-called "first order approach" which uses minimal assumptions on the coefficients and thus allows for complex coefficients and for systems of equations. This self-contained exposition of the first order approach offers new results with detailed proofs in a clear and accessible way and will become a valuable reference for graduate students and researchers working in partial differential equations and harmonic analysis.

Free-breathing contrast-enhanced T1-weighted gradient-echo imaging with radial k-space sampling for paediatric abdominopelvic MRI

Energy Technology Data Exchange (ETDEWEB)

Chandarana, Hersh; Block, Kai T.; Winfeld, Matthew J.; Lala, Shailee V.; Mazori, Daniel; Giuffrida, Emalyn; Babb, James S.; Milla, Sarah S. [New York University Langone Medical Center, Department of Radiology, New York, NY (United States)

2014-02-15

To compare the image quality of contrast-enhanced abdominopelvic 3D fat-suppressed T1-weighted gradient-echo imaging with radial and conventional Cartesian k-space acquisition schemes in paediatric patients. Seventy-three consecutive paediatric patients were imaged at 1.5 T with sequential contrast-enhanced T1-weighted Cartesian (VIBE) and radial gradient echo (GRE) acquisition schemes with matching parameters when possible. Cartesian VIBE was acquired as a breath-hold or as free breathing in patients who could not suspend respiration, followed by free-breathing radial GRE in all patients. Two paediatric radiologists blinded to the acquisition schemes evaluated multiple parameters of image quality on a five-point scale, with higher score indicating a more optimal examination. Lesion presence or absence, conspicuity and edge sharpness were also evaluated. Mixed-model analysis of variance was performed to compare radial GRE and Cartesian VIBE. Radial GRE had significantly (all P < 0.001) higher scores for overall image quality, hepatic edge sharpness, hepatic vessel clarity and respiratory motion robustness than Cartesian VIBE. More lesions were detected on radial GRE by both readers than on Cartesian VIBE, with significantly higher scores for lesion conspicuity and edge sharpness (all P < 0.001). Radial GRE has better image quality and lesion conspicuity than conventional Cartesian VIBE in paediatric patients undergoing contrast-enhanced abdominopelvic MRI. (orig.)

Maternal risk factors associated with low birth weight

International Nuclear Information System (INIS)

Khan, N.; Jamal, M.

2003-01-01

Objective: To determine the association of socio-demographic, maternal, medical and obstetric risk factors with low birth weight. Results: The mean weight of cases was 2.08 kg as compared to 3.1 in controls. Forty-sixty percent of cases were preterm. The factors like maternal malnutrition, young age of the mothers, poverty, close birth spacing, hypertension and antenatal per vagamin (p/v) bleeding during pregnancy have independent effect in causing low birth weight (LBW). Conclusion: Maternal bio social, medical and obstetric factors have strong association with LBW. To overcome this problem, special attention is required to strengthen the mother and child health care services in the community. (author)

Powering the Space Exploration Initiative

International Nuclear Information System (INIS)

Bennett, G.L.

1991-01-01

The Space Exploration Initiative (SEI) establishes the long-term goal of returning to the Moon and then exploring Mars. One of the prerequisites of SEI is the Exploration Technology Program which includes program elements on space nuclear power and surface solar power. These program elements in turn build upon the ongoing NASA research and technology base program in space energy conversion. There is a wide range of missions in NASA's strategic planning and most would benefit from power sources with improved efficiency, lighter weight and reduced cost

Multifunctional Metal-Polymer Nanocomposites for Space Applications, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA has identified a need for new high performance-to-weight materials capable of protecting critical components from the space environment, mitigating threat of...

[Etiological and exacerbation factors for COPD. Body weight loss].

Science.gov (United States)

Yokoyama, Akihito

2016-05-01

Hunger or malnutrition is not only a historical issue but also a current problem worldwide. Biological responses to hunger are evolutionary prepared in our body, including energy generation by degradation of body proteins. Extreme weight loss (malnutrition) can cause air space enlargement in human and rodents. However, the changes in rodents could be reversible, since refeeding could repair the pathology. On the other hand, weight loss is a common feature in patients with more severe COPD. Complex factors, such as increased energy consumption, decreased food uptake by low grade inflammation, socio-economic factors and so on, are involved in weight loss. Weight loss in patients with COPD also increases the risk of exacerbation, hospitalization, and death.

Symmetry-adapted Liouville space. Pt. 8

International Nuclear Information System (INIS)

Temme, F.P.

1990-01-01

A generalized hierarchy over lexical weight-sets is shown to provide significant insight into the structure of identical higher I i spin clusters under the S n /SO(3) dual groups. The use of combinatorial S n word-lengths allows one to derive the dual irreps directly from the combinatorics inherent in the adapted spin space. These advantages arise from the intimate connections between the scalar invariants of Cayley algebra over a field and their lexical combinatorics over vertical strokeI, Σ i M i , ()> space, which itself is a consequence of the S n -group representational algebra. By taking the highest SO(3) weight as the lexical origin, the calculations become recursive over all further expansions of the spin space, i.e., arising from an enhanced magnitude for the component nuclear spins, I i . The method over Hilbert space for spin clusters of I i ≤ 9/2 is more direct than those associated with unitary group algebras; in addition, the cogent beauty of combinatorial concepts derived from Cayley algebra deserves wider recognition in the physical sciences. (orig.)

he First Superconductivity Experiment in Space

International Nuclear Information System (INIS)

Polturak, E.; Koren, G.

1999-01-01

One of the most promising applications of high Tc superconductors is in the field of satellite communications. In view of the rapidly increasing demand for satellite communication channels due to the formation of global networks of cellular phones, internet, etc., one needs to (develop more efficient ways of dividing the finite frequency band into more and more channels without paying for it with excessive interference or an increasingly large weight of conventional filters. Superconductive components can save an order of magnitude on the weight and volume of such filters, a very important factor in satellite design. Yet, up to now superconductors were never tested in space. We present the design and performance of the first such experiment to reach space. The experiment consists of a thin film HTSC device integrated with a miniature cryo cooler. It was launched into space in July 1998 aboard the Thatch's-II micro satellite. We will present data obtained from this experiment until the present time. Long term survivability of HTSC devices in space would be discussed

Eigenvalues, embeddings and generalised trigonometric functions

CERN Document Server

Lang, Jan

2011-01-01

The main theme of the book is the study, from the standpoint of s-numbers, of integral operators of Hardy type and related Sobolev embeddings. In the theory of s-numbers the idea is to attach to every bounded linear map between Banach spaces a monotone decreasing sequence of non-negative numbers with a view to the classification of operators according to the way in which these numbers approach a limit: approximation numbers provide an especially important example of such numbers. The asymptotic behavior of the s-numbers of Hardy operators acting between Lebesgue spaces is determined here in a wide variety of cases. The proof methods involve the geometry of Banach spaces and generalized trigonometric functions; there are connections with the theory of the p-Laplacian.

Quantum mechanics in phase space

DEFF Research Database (Denmark)

Hansen, Frank

1984-01-01

A reformulation of quantum mechanics for a finite system is given using twisted multiplication of functions on phase space and Tomita's theory of generalized Hilbert algebras. Quantization of a classical observable h is achieved when the twisted exponential Exp0(-h) is defined as a tempered....... Generalized Weyl-Wigner maps related to the notion of Hamiltonian weight are studied and used in the formulation of a twisted spectral theory for functions on phase space. Some inequalities for Wigner functions on phase space are proven. A brief discussion of the classical limit obtained through dilations...

Mobius invariant QK spaces

CERN Document Server

Wulan, Hasi

2017-01-01

This monograph summarizes the recent major achievements in Möbius invariant QK spaces. First introduced by Hasi Wulan and his collaborators, the theory of QK spaces has developed immensely in the last two decades, and the topics covered in this book will be helpful to graduate students and new researchers interested in the field. Featuring a wide range of subjects, including an overview of QK spaces, QK-Teichmüller spaces, K-Carleson measures and analysis of weight functions, this book serves as an important resource for analysts interested in this area of complex analysis. Notes, numerous exercises, and a comprehensive up-to-date bibliography provide an accessible entry to anyone with a standard graduate background in real and complex analysis.

Light weight hollow maxillary complete denture: A case series

Directory of Open Access Journals (Sweden)

Laxman Singh Kaira

2012-01-01

Full Text Available Retention, stability and support are the basic principles on which the success of a complete denture relies on. The skill lies in applying these principles efficiently in critical situations. Residual ridge resorption occurs at a three times faster rate in mandibular arch than in the maxillary arch. The severely resorbed maxillary and mandibular edentulous arches that are narrow and constricted with increased interarch space provide decreased support, retention and stability. The consequent weight of the processed complete denture only compromises them further. The severely resorbed jaw can have various treatment options. Extreme resorption of the maxillary denture-bearing area may lead to problems with prosthetic rehabilitation. The advantage of a hollow maxillary or mandibular denture is the reduction of excessive weight of acrylic resin, which normally replaces lost alveolar ridge in the interridge space of the denture wearer. This clinical report describes two case reports of edentulous patients with resorbed ridges where a simplified technique of fabricating a light weight hollow maxillary complete denture was used for the preservation of denture bearing areas.

Space Industry Commercialization: A Systems Engineering Evaluation of Alternatives

Science.gov (United States)

Dinally, Jihan

The Constellation Program cancellation reversed the government and commercial space industry's roles and relationships by dedicating the majority of the federal funding and opportunities to the commercial space industry and left the government space industry in search of an approach to collaborate with the dominant organization, the commercial space industry service providers. The space industry government agencies, Air Force Space Command (AFSPC) and National Aeronautics and Space Administration (NASA) had realized that to gain resources in the new commercially oriented economic environment, they had to work together and possess the capabilities aligned with the National Space Policy's documented goals. Multi-organizational collaboration in space industry programs is challenging, as NASA, AFSPC, and commercial providers, follow different [1] enterprise architecture guidance such as the NASA systems engineering Handbook, MIL-STD-499 and "A Guide to the systems engineering Body of Knowledge" by the International Council on systems engineering [2] [3]. A solution to streamline their enterprise architecture documentation and meet National Space Policy goals is the Multi-User Architecture Maturity Model Methodology (MAM3), which offers a tailored systems engineering technique the government agencies and private companies can implement for the program's maturity level. In order to demonstrate the MAM3, a CubeSat motivated study was conducted partnering a commercial provider with a government agency. A survey of the commercial space industry service providers' capabilities was performed to select the private companies for the study. Using the survey results, the commercial space industry service providers were ranked using the Analytic Hierarchy Process (AHP) [4]. The AHP is a structured technique for making complex decisions for representing and quantifying its weights, relating those weights to overall goals, and evaluating alternative solutions [5] - [8]. The weights

EDIN0613P weight estimating program. [for launch vehicles

Science.gov (United States)

Hirsch, G. N.

1976-01-01

The weight estimating relationships and program developed for space power system simulation are described. The program was developed to size a two-stage launch vehicle for the space power system. The program is actually part of an overall simulation technique called EDIN (Engineering Design and Integration) system. The program sizes the overall vehicle, generates major component weights and derives a large amount of overall vehicle geometry. The program is written in FORTRAN V and is designed for use on the Univac Exec 8 (1110). By utilizing the flexibility of this program while remaining cognizant of the limits imposed upon output depth and accuracy by utilization of generalized input, this program concept can be a useful tool for estimating purposes at the conceptual design stage of a launch vehicle.

Bessel-Weighted Asymmetries in Semi Inclusive Deep Inelastic Scattering

International Nuclear Information System (INIS)

Boer, D.; Gamberg, L.; Musch, B.U.; Prokudin, A.

2011-01-01

The concept of weighted asymmetries is revisited for semi-inclusive deep inelastic scattering. We consider the cross section in Fourier space, conjugate to the outgoing hadron's transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. Advantages of employing these Bessel weights are that they suppress (divergent) contributions from high transverse momentum and that soft factors cancel in (Bessel-) weighted asymmetries. Also, the resulting compact expressions immediately connect to previous work on evolution equations for transverse momentum dependent parton distribution and fragmentation functions and to quantities accessible in lattice QCD. Bessel weighted asymmetries are thus model independent observables that augment the description and our understanding of correlations of spin and momentum in nucleon structure.

The space shuttle program from challenge to achievement: Space exploration rolling on tires

Science.gov (United States)

Felder, G. L.

1985-01-01

The Space Shuttle Transportation System is the first space program to employ the pneumatic tire as a part of space exploration. For aircraft tires, this program establishes new expectations as to what constitutes acceptable performance within a set of tough environmental and operational conditions. Tire design, stresses the usual low weight, high load, high speed, and excellent air retention features but at extremes well outside industry standards. Tires will continue to be an integral part of the Shuttle's landing phase in the immediate future since they afford a unique combination of directional control, braking traction, flotation and shock absorption not available by other systems.

Boundary value problems and Fourier expansions

CERN Document Server

MacCluer, Charles R

2004-01-01

Based on modern Sobolev methods, this text for advanced undergraduates and graduate students is highly physical in its orientation. It integrates numerical methods and symbolic manipulation into an elegant viewpoint that is consonant with implementation by digital computer. The first five sections form an informal introduction that develops students' physical and mathematical intuition. The following section introduces Hilbert space in its natural environment, and the next six sections pose and solve the standard problems. The final seven sections feature concise introductions to selected topi

Mathematical analysis of Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation

OpenAIRE

Rozanova-Pierrat , Anna

2006-01-01

We consider the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation (ut — uux — βuxx)x— γΔy u = 0 in Sobolev spaces of functions periodic in x and with mean value zero. The derivation of KZK from the nonlinear isentropic Navier Stokes equations and the approximation of their solutions (for viscous and non viscous cases), the results of the existence, uniqueness, stability and blow-up of solution of KZK equation are obtained, also a result of existence of a smooth solution of Navier-Stokes system i...

The weight hierarchies and chain condition of a class of codes from varieties over finite fields

Science.gov (United States)

Wu, Xinen; Feng, Gui-Liang; Rao, T. R. N.

1996-01-01

The generalized Hamming weights of linear codes were first introduced by Wei. These are fundamental parameters related to the minimal overlap structures of the subcodes and very useful in several fields. It was found that the chain condition of a linear code is convenient in studying the generalized Hamming weights of the product codes. In this paper we consider a class of codes defined over some varieties in projective spaces over finite fields, whose generalized Hamming weights can be determined by studying the orbits of subspaces of the projective spaces under the actions of classical groups over finite fields, i.e., the symplectic groups, the unitary groups and orthogonal groups. We give the weight hierarchies and generalized weight spectra of the codes from Hermitian varieties and prove that the codes satisfy the chain condition.

Real photon spectral weight functions, imaginary part of vacuum polarization and electromagnetic vertices

International Nuclear Information System (INIS)

Chahine, C.; College de France, 75 - Paris. Lab. de Physique Corpusculaire)

1978-02-01

The concept of a real photon spectral weight function for any cross-section involving charged particles is introduced as a simple approximation taking into account the soft part of photon emission to all orders in perturbation theory. The spectral weight function replaces the energy-momentum conservation delta function in the elastic cross-section. The spectral weight function is computed in closed form in space-time and in the peaking approximation in momentum space. The spectral weight function description is applied to the imaginary part of vacuum polarization ImPI and to electron-proton scattering. A spectral representation for ImPI is derived and its content compared with the known fourth order result, showing in particular the identity of the soft and peaking approximations in lowest order. The virtual photon radiative corrections are discussed in part, with emphasis on the threshold behavior of the vertex functions. A relativistic generalization of the electric non-relativistic vertex function is given, whose asymptotic behavior is approppriate to use in conjuction with the spectral weight function

Assembly of Space CFRP Structures with Racing Sailing Boats Technology

Science.gov (United States)

Nieto, Jose; Yuste, Laura; Pipo, Alvaro; Santarsiero, Pablo; Bureo, Rafael

2014-06-01

Carbon Fiber Reinforced Plastic (CFRP) is commonly used in space applications to get structures with good mechanical performances and a reduced mass. Most of larger parts of spatial structures are already made of CFRP but the achieved weight saving may be jeopardized by the use of metallic brackets as joining elements. This paper describes the work carried out to study and evaluate ways of reducing weight and costs of the joints between structural elements commonly used in space applications.The main objective of this project is to adapt design solutions coming from the racing sailing boats technology to space applications: the use of out-of autoclave (OoA) cured CFRP joints. In addition to that other CFRP solution common in space business, 3D- RTM Bracket, has been evaluated.This development studies the manufacturing and assembly feasibility making use of these CFRP technologies.This study also compares traditional metallic solutions with innovative CFRP ones in terms of mechanical performances at elementary level. Weight and cost of presented solutions are also compared.

Weighted Anisotropic Integral Representations of Holomorphic Functions in the Unit Ball of

Directory of Open Access Journals (Sweden)

Arman Karapetyan

2010-01-01

Full Text Available We obtain weighted integral representations for spaces of functions holomorphic in the unit ball and belonging to area-integrable weighted -classes with “anisotropic” weight function of the type ∏=1(1−|1|2−|2|2−⋯−||2, =(1,2,…,∈. The corresponding kernels of these representations are estimated, written in an integral form, and even written out in an explicit form (for =2.

Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

Energy Technology Data Exchange (ETDEWEB)

Qiao, Qin, E-mail: qqiao@ust.hk; Zhang, Hou-Dao [Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Huang, Xuhui, E-mail: xuhuihuang@ust.hk [Department of Chemistry, Division of Biomedical Engineering, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); The HKUST Shenzhen Research Institute, Shenzhen (China)

2016-04-21

Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

Science.gov (United States)

Qiao, Qin; Zhang, Hou-Dao; Huang, Xuhui

2016-04-01

Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

International Nuclear Information System (INIS)

Qiao, Qin; Zhang, Hou-Dao; Huang, Xuhui

2016-01-01

Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

The Space House TM : Space Technologies in Architectural Design

Science.gov (United States)

Gampe, F.; Raitt, D.

2002-01-01

The word "space" has always been associated with and had a profound impact upon architectural design. Until relatively recently, however, the term has been used in a different sense to that understood by the aerospace community - for them, space was less abstract, more concrete and used in the context of space flight and space exploration, rather than, say, an empty area or space requiring to be filled by furniture. However, the two senses of the word space have now converged to some extent. Interior designers and architects have been involved in designing the interior of Skylab, the structure of the International Space Station, and futuristic space hotels. Today, architects are designing, and builders are building, houses, offices and other structures which incorporate a plethora of new technologies, materials and production processes in an effort not only to introduce innovative and adventurous ideas but also in an attempt to address environmental and social issues. Foremost among these new technologies and materials being considered today are those that have been developed for and by the space industry. This paper examines some of these space technologies, such as energy efficient solar cells, durable plastics, air and water filtration techniques, which have been adapted to both provide power while reducing energy consumption, conserve resources and so on. Several of these technologies have now been employed by the European Space Agency to develop a Space House TM - the first of its kind, which will be deployed not so much on planets like Mars, but rather here on Earth. The Space House TM, which exhibits many innovative features such as high strength light-weight carbon composites, active noise-damped, (glass and plastic) windows, low-cost solar arrays and latent heat storage, air and water purification systems will be described.

Virtual continuity of measurable functions and its applications

Science.gov (United States)

Vershik, A. M.; Zatitskii, P. B.; Petrov, F. V.

2014-12-01

A classical theorem of Luzin states that a measurable function of one real variable is `almost' continuous. For measurable functions of several variables the analogous statement (continuity on a product of sets having almost full measure) does not hold in general. The search for a correct analogue of Luzin's theorem leads to a notion of virtually continuous functions of several variables. This apparently new notion implicitly appears in the statements of embedding theorems and trace theorems for Sobolev spaces. In fact it reveals the nature of such theorems as statements about virtual continuity. The authors' results imply that under the conditions of Sobolev theorems there is a well-defined integration of a function with respect to a wide class of singular measures, including measures concentrated on submanifolds. The notion of virtual continuity is also used for the classification of measurable functions of several variables and in some questions on dynamical systems, the theory of polymorphisms, and bistochastic measures. In this paper the necessary definitions and properties of admissible metrics are recalled, several definitions of virtual continuity are given, and some applications are discussed. Bibliography: 24 titles.

On the holonomy of the Coulomb connection over manifolds with boundary

International Nuclear Information System (INIS)

Gryc, William E.

2008-01-01

Narasimhan and Ramadas [Commun. Math. Phys. 67, 121 (1979)] showed that the restricted holonomy group of the Coulomb connection is dense in the connected component of the identity of the gauge group when one considers the product principal bundle S 3 xSU(2)→S 3 . Instead of a base manifold S 3 , we consider here a base manifold of dimension n≥2 with a boundary and use Dirichlet boundary conditions on connections as defined by Marini [Commun. Pure Appl. Math. 45, 1015 (1992)]. A key step in the method of Narasimhan and Ramadas consisted in showing that the linear space spanned by the curvature form at one specially chosen connection is dense in the holonomy Lie algebra with respect to an appropriate Sobolev norm. Our objective is to explore the effect of the presence of a boundary on this construction of the holonomy Lie algebra. Fixing appropriate Sobolev norms, it will be shown that the space spanned, linearly, by the curvature form at any one connection is never dense in the holonomy Lie algebra. In contrast, the linear space spanned by the curvature form and its first commutators at the flat connection is dense and, in the C ∞ category, is in fact the entire holonomy Lie algebra. The former, negative, theorem is proven for a general principle bundle over M, while the latter, positive, theorem is proven only for a product bundle over the closure of a bounded open subset of R n . Our technique for proving the absence of density consists in showing that the linear space spanned by the curvature form at one point is contained in the kernel of a linear map consisting of a third order differential operator, followed by a restriction operation at the boundary; this mapping is determined by the mean curvature of the boundary

On High Dimensional Searching Spaces and Learning Methods

DEFF Research Database (Denmark)

Yazdani, Hossein; Ortiz-Arroyo, Daniel; Choros, Kazimierz

2017-01-01

, and similarity functions and discuss the pros and cons of using each of them. Conventional similarity functions evaluate objects in the vector space. Contrarily, Weighted Feature Distance (WFD) functions compare data objects in both feature and vector spaces, preventing the system from being affected by some...

Structural weights analysis of advanced aerospace vehicles using finite element analysis

Science.gov (United States)

Bush, Lance B.; Lentz, Christopher A.; Rehder, John J.; Naftel, J. Chris; Cerro, Jeffrey A.

1989-01-01

A conceptual/preliminary level structural design system has been developed for structural integrity analysis and weight estimation of advanced space transportation vehicles. The system includes a three-dimensional interactive geometry modeler, a finite element pre- and post-processor, a finite element analyzer, and a structural sizing program. Inputs to the system include the geometry, surface temperature, material constants, construction methods, and aerodynamic and inertial loads. The results are a sized vehicle structure capable of withstanding the static loads incurred during assembly, transportation, operations, and missions, and a corresponding structural weight. An analysis of the Space Shuttle external tank is included in this paper as a validation and benchmark case of the system.

Semi-Inclusive Deep Inelastic Scattering and Bessel-Weighted Asymmetries

International Nuclear Information System (INIS)

Gamberg, Leonard; Boer, Daniel; Musch, Bernhard; Prokudin, Alexei

2012-01-01

We consider the cross section in Fourier space, conjugate to the outgoing hadron's transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. Advantages of employing these Bessel weights are that they suppress (divergent) contributions from high transverse momentum and that soft factors cancel in (Bessel-) weighted asymmetries. Also, the resulting compact expressions immediately connect to previous work on evolution equations for transverse momentum dependent parton distribution and fragmentation functions and to quantities accessible in lattice QCD. Bessel-weighted asymmetries are thus model independent observables that augment the description and our understanding of correlations of spin and momentum in nucleon structure.

Bessel-weighted asymmetries in semi-inclusive deep inelastic scattering

NARCIS (Netherlands)

Boer, D.; Gamberg, L.; Musch, B. U.; Prokudin, A.

2011-01-01

The concept of weighted asymmetries is revisited for semi-inclusive deep inelastic scattering. We consider the cross section in Fourier space, conjugate to the outgoing hadron's transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation

Cesic: optomechanical technology last development results and new HBCesic highly light weighted space mirror development including corrective function 7th international conference on space optics, october 2008

Science.gov (United States)

Devilliers, Christophe; Kroedel, Mathias

2017-11-01

Thales-Alenia-Space and ECM has developed a new SiC ceramic composite to produce very lightweight space mirrors and structure. Cesicmade by ECM has been selected for its own intrinsic properties ( high specific Young modulus, high conductivity , low CTE, high strength for a ceramics) and its large manufacturing capabilities. Recently a full monolithic space instrument for earth observation, with a monolithic Cesicstructure and with Cesicmirrors has been designed, manufactured and space qualified and is now ready for launch. The Cesictelescope assembly has been tested under shock environment, vibration loads, and full qualification thermal environment. All these qualification tests were done directly on the flight model. Extensive development has been also performed to design, size, manufacture and test a very light weight reflector shell made as a single part. This 1 meter reflective shell has an areal density of less than 10 Kg/m2 has been manufactured with its surface grounded to the bi parabolic shape. Such challenging areal density has requested a very thin skin associated with a ribs thickness of less than 2mm. In order to demonstrate the high stability and strength of Cesicthe reflector has been tested successfully under very aggressive environment up to 350°C and also an acoustic test with flight representative levels was successfully performed. To produce future very lightweight space mirrors ECM develop with the support of Thales-Alenia-Space since some years an improved version of Cesicceramic, called HB-Cesic©. HB-Cesicmade by ECM is developed for its higher intrinsic properties, Young modulus, strength and especially its direct polishing capabilities down to 3 nm micro-roughness. One of the major targets for this development was also to overcome size limitations of the C/C raw material of currently around 1x1 m to produce mirror up to 3,5 m diameter out of a single C/C raw material block. Under ESA study a 600 mm mirror with a surface density of only

On the well-posedness of the Schrödinger-Korteweg-de Vries system

Science.gov (United States)

Guo, Zihua; Wang, Yuzhao

We prove that the Cauchy problem for the Schrödinger-Korteweg-de Vries system is locally well-posed for the initial data belonging to the Sobolev spaces L(R)×H(R), and H(R)×H(R) ( s>-1/16) for the resonant case. The new ingredient is that we use the F-type space, introduced by the first author in Guo (2009) [10], to deal with the KdV part of the system and the coupling terms. In order to overcome the difficulty caused by the lack of scaling invariance, we prove uniform estimates for the multiplier. This result improves the previous one by Corcho and Linares (2007) [6].

Eigenvector Weighting Function in Face Recognition

Directory of Open Access Journals (Sweden)

Pang Ying Han

2011-01-01

Full Text Available Graph-based subspace learning is a class of dimensionality reduction technique in face recognition. The technique reveals the local manifold structure of face data that hidden in the image space via a linear projection. However, the real world face data may be too complex to measure due to both external imaging noises and the intra-class variations of the face images. Hence, features which are extracted by the graph-based technique could be noisy. An appropriate weight should be imposed to the data features for better data discrimination. In this paper, a piecewise weighting function, known as Eigenvector Weighting Function (EWF, is proposed and implemented in two graph based subspace learning techniques, namely Locality Preserving Projection and Neighbourhood Preserving Embedding. Specifically, the computed projection subspace of the learning approach is decomposed into three partitions: a subspace due to intra-class variations, an intrinsic face subspace, and a subspace which is attributed to imaging noises. Projected data features are weighted differently in these subspaces to emphasize the intrinsic face subspace while penalizing the other two subspaces. Experiments on FERET and FRGC databases are conducted to show the promising performance of the proposed technique.

Error estimates of Lagrange interpolation and orthonormal expansions for Freud weights

Science.gov (United States)

Kwon, K. H.; Lee, D. W.

2001-08-01

Let Sn[f] be the nth partial sum of the orthonormal polynomials expansion with respect to a Freud weight. Then we obtain sufficient conditions for the boundedness of Sn[f] and discuss the speed of the convergence of Sn[f] in weighted Lp space. We also find sufficient conditions for the boundedness of the Lagrange interpolation polynomial Ln[f], whose nodal points are the zeros of orthonormal polynomials with respect to a Freud weight. In particular, if W(x)=e-(1/2)x2 is the Hermite weight function, then we obtain sufficient conditions for the inequalities to hold:andwhere and k=0,1,2...,r.

Carleman estimates, observability inequalities and null controllability for interior degenerate nonsmooth parabolic equations

CERN Document Server

Fragnelli, Genni

2016-01-01

The authors consider a parabolic problem with degeneracy in the interior of the spatial domain, and they focus on observability results through Carleman estimates for the associated adjoint problem. The novelties of the present paper are two. First, the coefficient of the leading operator only belongs to a Sobolev space. Second, the degeneracy point is allowed to lie even in the interior of the control region, so that no previous result can be adapted to this situation; however, different cases can be handled, and new controllability results are established as a consequence.

Friction Plug Weld Repair for the Space Shuttle External Tank

Science.gov (United States)

Hartley, Paula J.; McCool, A. (Technical Monitor)

2000-01-01

Lockheed Martin Space Systems, Michoud Operations in New Orleans, LA is the manufacturer of the External Fuel Tanks (ET) for the Space Transportation System (STS). The ET contains and delivers the propellants used by the Orbiters three main engines. Additionally, it also serves as the structural backbone for the Orbiter and the two Solid Rocket Boosters (SRB), which combined, constitute the STS. In 1994, NASA established that in order to launch the International Space Station, the performance of the STS must be improved. One option was to reduce the weight of the ET, which would enable sufficient increase in performance. With the development of the Weldalite(R) series of Al-Cu-Li alloys in the late 1980's, Lockheed Martin was postured to replace the current A12219 fuel tanks with the high strength, light weight A12195 alloy. With the use of A12195 and some component redesign, the weight of the Super Lightweight (SLWT) ET was reduced by approximately 7,000 pounds, which added as much capability to the Space Shuttle. Since June 1998, seven STS missions have been successful with the use of the SLWT ET's.

Soliton Resolution for the Derivative Nonlinear Schrödinger Equation

Science.gov (United States)

Jenkins, Robert; Liu, Jiaqi; Perry, Peter; Sulem, Catherine

2018-05-01

We study the derivative nonlinear Schrödinger equation for generic initial data in a weighted Sobolev space that can support bright solitons (but exclude spectral singularities). Drawing on previous well-posedness results, we give a full description of the long-time behavior of the solutions in the form of a finite sum of localized solitons and a dispersive component. At leading order and in space-time cones, the solution has the form of a multi-soliton whose parameters are slightly modified from their initial values by soliton-soliton and soliton-radiation interactions. Our analysis provides an explicit expression for the correction dispersive term. We use the nonlinear steepest descent method of Deift and Zhou (Commun Pure Appl Math 56:1029-1077, 2003) revisited by the {\\overline{partial}} -analysis of McLaughlin and Miller (IMRP Int Math Res Pap 48673:1-77, 2006) and Dieng and McLaughlin (Long-time asymptotics for the NLS equation via dbar methods. Preprint, arXiv:0805.2807, 2008), and complemented by the recent work of Borghese et al. (Ann Inst Henri Poincaré Anal Non Linéaire, https://doi.org/10.1016/j.anihpc.2017.08.006, 2017) on soliton resolution for the focusing nonlinear Schrödinger equation. Our results imply that N-soliton solutions of the derivative nonlinear Schrödinger equation are asymptotically stable.

Comparative study of standard space and real space analysis of quantitative MR brain data.

Science.gov (United States)

Aribisala, Benjamin S; He, Jiabao; Blamire, Andrew M

2011-06-01

To compare the robustness of region of interest (ROI) analysis of magnetic resonance imaging (MRI) brain data in real space with analysis in standard space and to test the hypothesis that standard space image analysis introduces more partial volume effect errors compared to analysis of the same dataset in real space. Twenty healthy adults with no history or evidence of neurological diseases were recruited; high-resolution T(1)-weighted, quantitative T(1), and B(0) field-map measurements were collected. Algorithms were implemented to perform analysis in real and standard space and used to apply a simple standard ROI template to quantitative T(1) datasets. Regional relaxation values and histograms for both gray and white matter tissues classes were then extracted and compared. Regional mean T(1) values for both gray and white matter were significantly lower using real space compared to standard space analysis. Additionally, regional T(1) histograms were more compact in real space, with smaller right-sided tails indicating lower partial volume errors compared to standard space analysis. Standard space analysis of quantitative MRI brain data introduces more partial volume effect errors biasing the analysis of quantitative data compared to analysis of the same dataset in real space. Copyright © 2011 Wiley-Liss, Inc.

Poor birth weight recovery among low birth weight/preterm infants following hospital discharge in Kampala, Uganda

Directory of Open Access Journals (Sweden)

Namiiro Flavia B

2012-01-01

Full Text Available Abstract Background Healthy infants typically regain their birth weight by 21 days of age; however, failure to do so may be due to medical, nutritional or environmental factors. Globally, the incidence of low birth weight deliveries is high, but few studies have assessed the postnatal weight changes in this category of infants, especially in Africa. The aim was to determine what proportion of LBW infants had not regained their birth weight by 21 days of age after discharge from the Special Care Unit of Mulago hospital, Kampala. Methods A cross sectional study was conducted assessing weight recovery of 235 LBW infants attending the Kangaroo Clinic in the Special Care Unit of Mulago Hospital between January and April 2010. Infants aged 21 days with a documented birth weight and whose mothers gave consent to participate were included in the study. Baseline information was collected on demographic characteristics, history on pregnancy, delivery and postnatal outcome through interviews. Pertinent infant information like gestation age, diagnosis and management was obtained from the medical records and summarized in the case report forms. Results Of the 235 LBW infants, 113 (48.1% had not regained their birth weight by 21 days. Duration of hospitalization for more than 7 days (AOR: 4.2; 95% CI: 2.3 - 7.6; p value Conclusion Failure to regain birth weight among LBW infants by 21 days of age is a common problem in Mulago Hospital occurring in almost half of the neonates attending the Kangaroo clinic. Currently, the burden of morbidity in this group of high-risk infants is undetected and unaddressed in many developing countries. Measures for consideration to improve care of these infants would include; discharge after regaining birth weight and use of total parenteral nutrition. However, due to the pressure of space, keeping the baby and mother is not feasible at the moment hence the need for a strong community system to boost care of the infant. Close

Comparative empirical analysis of flow-weighted transit route networks in R-space and evolution modeling

Science.gov (United States)

Huang, Ailing; Zang, Guangzhi; He, Zhengbing; Guan, Wei

2017-05-01

Urban public transit system is a typical mixed complex network with dynamic flow, and its evolution should be a process coupling topological structure with flow dynamics, which has received little attention. This paper presents the R-space to make a comparative empirical analysis on Beijing’s flow-weighted transit route network (TRN) and we found that both the Beijing’s TRNs in the year of 2011 and 2015 exhibit the scale-free properties. As such, we propose an evolution model driven by flow to simulate the development of TRNs with consideration of the passengers’ dynamical behaviors triggered by topological change. The model simulates that the evolution of TRN is an iterative process. At each time step, a certain number of new routes are generated driven by travel demands, which leads to dynamical evolution of new routes’ flow and triggers perturbation in nearby routes that will further impact the next round of opening new routes. We present the theoretical analysis based on the mean-field theory, as well as the numerical simulation for this model. The results obtained agree well with our empirical analysis results, which indicate that our model can simulate the TRN evolution with scale-free properties for distributions of node’s strength and degree. The purpose of this paper is to illustrate the global evolutional mechanism of transit network that will be used to exploit planning and design strategies for real TRNs.

A new type of phase-space path integral

International Nuclear Information System (INIS)

Marinov, M.S.

1991-01-01

Evolution of Wigner's quasi-distribution of a quantum system is represented by means of a path integral in phase space. Instead of the Hamiltonian action, a new functional is present in the integral, and its extrema in the functional space are also given by the classical trajectories. The phase-space paths appear in the integral with real weights, so complex integrals are not necessary. The semiclassical approximation and some applications are discussed briefly. (orig.)

A Study Of Risk Factors For Low Birth Weight

Directory of Open Access Journals (Sweden)

Deswal B S

1999-01-01

Full Text Available Research question: What is the extent of low weight babies born in hospitals and its association with some maternal factors? Objectives: 1. To find an overall prevalence of low birth weight babies amongst hospital births in Meerut city. 2. To identify and quantify the effects of some risk factors for low birth weight. Setting: District women Hospital of Meerut city of western U.P. Study Design: Hospital based matched case-control study. Sample size: 491 low birth weight babies as ‘cases’ and an equal number of babies of normal birth weight in ‘control’ group matched for maternal age, sex of baby, birth order and institution of delivery. Study variables: Socio-economic Status: maternal biological factors including obstetric history: antenatal factors: nutritional factors: history of abortion: toxaemia of pregnancy etc. Results: Overall proportion of low birth weight babies was found to be 21.8% amongst hospital live births and 30.9% born to mothers aged below 30 years of age. Low maternal weight, under nutrition, lack of antenatal care, short inter-pregnancy interval, toxacmia of pregnancy were independent factors increasing the risk of low birth weight significantly. Conclusions: The study suggested that a substantial proportion of low birth weight babies can be averted by improving maternal nutritional status including anemic condition, birth spacing and proper antenatal care.

Energy decay for wave equations of phi-Laplacian type with weakly nonlinear dissipation

Directory of Open Access Journals (Sweden)

Aissa Guesmia

2008-08-01

Full Text Available In this paper, first we prove the existence of global solutions in Sobolev spaces for the initial boundary value problem of the wave equation of $phi$-Laplacian with a general dissipation of the form $$ (|u'|^{l-2}u''-Delta_{phi}u+sigma(t g(u'=0 quadext{in } Omegaimes mathbb{R}_+ , $$ where $Delta_{phi}=sum_{i=1}^n partial_{x_i}igl(phi (|partial_{x_i}|^2partial_{x_i}igr$. Then we prove general stability estimates using multiplier method and general weighted integral inequalities proved by the second author in [18]. Without imposing any growth condition at the origin on $g$ and $phi$, we show that the energy of the system is bounded above by a quantity, depending on $phi$, $sigma$ and $g$, which tends to zero (as time approaches infinity. These estimates allows us to consider large class of functions $g$ and $phi$ with general growth at the origin. We give some examples to illustrate how to derive from our general estimates the polynomial, exponential or logarithmic decay. The results of this paper improve and generalize many existing results in the literature, and generate some interesting open problems.

Acoustic-noise-optimized diffusion-weighted imaging.

Science.gov (United States)

Ott, Martin; Blaimer, Martin; Grodzki, David M; Breuer, Felix A; Roesch, Julie; Dörfler, Arnd; Heismann, Björn; Jakob, Peter M

2015-12-01

This work was aimed at reducing acoustic noise in diffusion-weighted MR imaging (DWI) that might reach acoustic noise levels of over 100 dB(A) in clinical practice. A diffusion-weighted readout-segmented echo-planar imaging (EPI) sequence was optimized for acoustic noise by utilizing small readout segment widths to obtain low gradient slew rates and amplitudes instead of faster k-space coverage. In addition, all other gradients were optimized for low slew rates. Volunteer and patient imaging experiments were conducted to demonstrate the feasibility of the method. Acoustic noise measurements were performed and analyzed for four different DWI measurement protocols at 1.5T and 3T. An acoustic noise reduction of up to 20 dB(A) was achieved, which corresponds to a fourfold reduction in acoustic perception. The image quality was preserved at the level of a standard single-shot (ss)-EPI sequence, with a 27-54% increase in scan time. The diffusion-weighted imaging technique proposed in this study allowed a substantial reduction in the level of acoustic noise compared to standard single-shot diffusion-weighted EPI. This is expected to afford considerably more patient comfort, but a larger study would be necessary to fully characterize the subjective changes in patient experience.

Weighting of field heights for sharpness and noisiness

Science.gov (United States)

Keelan, Brian W.; Jin, Elaine W.

2009-01-01

Weighting of field heights is important in cases when a single numerical value needs to be calculated that characterizes an attribute's overall impact on perceived image quality. In this paper we report an observer study to derive the weighting of field heights for sharpness and noisiness. One-hundred-forty images were selected to represent a typical consumer photo space distribution. Fifty-three sample points were sampled per image, representing field heights of 0, 14, 32, 42, 51, 58, 71, 76, 86% and 100%. Six observers participated in this study. The field weights derived in this report include both: the effect of area versus field height (which is a purely objective, geometric factor); and the effect of the spatial distribution of image content that draws attention to or masks each of these image structure attributes. The results show that relative to the geometrical area weights, sharpness weights were skewed to lower field heights, because sharpness-critical subject matter was often positioned relatively near the center of an image. Conversely, because noise can be masked by signal, noisiness-critical content (such as blue skies, skin tones, walls, etc.) tended to occur farther from the center of an image, causing the weights to be skewed to higher field heights.

A survey of weighted substitution operators and generalizations of Banach-stone theorem

OpenAIRE

R. K. Singh

2005-01-01

The classical Banach-Stone theorem characterizes linear surjective isometries between C(K)-spaces. The main aim of this paper is to present a survey of Banach-Stone-theorem-type results between some function spaces. The weighted substitution operators play an important role in characterization of isometries, disjointness preserving operators, and lattice homomorphisms. Some open problems are given for further investigation.

Metastatic thyroid follicular carcinoma of masticator space

International Nuclear Information System (INIS)

Gang, Tae In; Heo, Min Suk; An, Chang Hyeon; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won; Choi, Mi

2002-01-01

Follicular carcinomas are the second most common form of thyroid cancer, accounting for 10 to 20% of all thyroid cancers. Follicular carcinomas have a propensity to metastasize via the bloodstream, spreading to bone, lungs, liver, and elsewhere. We described the case of a 48-year-old woman who presented with swelling of the left pre auricular area, which was a consequence of a metastatic follicular carcinoma of the masticator space. Plain films showed ill defined erosive bony changes from the left condylar head to the mandibular notch. Contrast-enhanced CT images showed a well circumscribed round mass with well enhancement within left masticator space. On MR images, the mass was heterogenously hyperintense to the muscle on T2-weighted images and isointense or hyperintense to the muscle on T1-weighted images, and showed good enhancement on contrast-enhanced T1-weighted images. Upon microscopic examination, the metastatic mass was found to be composed of fairly uniform cells forming small follicles containing colloid, showing capsular and vascular invasion.

Lightweight Metal Rubber Wire and Cable for Space Power Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The objective of this NASA STTR program is to produce ultra-lightweight electrical wire and cable harnesses to reduce the liftoff weight of future space flight...

Multiphase Weakly Nonlinear Geometric Optics for Schrödinger Equations

KAUST Repository

Carles, Ré mi; Dumas, Eric; Sparber, Christof

2010-01-01

We describe and rigorously justify the nonlinear interaction of highly oscillatory waves in nonlinear Schrödinger equations, posed on Euclidean space or on the torus. Our scaling corresponds to a weakly nonlinear regime where the nonlinearity affects the leading order amplitude of the solution, but does not alter the rapid oscillations. We consider initial states which are superpositions of slowly modulated plane waves, and use the framework of Wiener algebras. A detailed analysis of the corresponding nonlinear wave mixing phenomena is given, including a geometric interpretation of the resonance structure for cubic nonlinearities. As an application, we recover and extend some instability results for the nonlinear Schrödinger equation on the torus in negative order Sobolev spaces. © 2010 Society for Industrial and Applied Mathematics.

Mindfulness Approaches and Weight Loss, Weight Maintenance, and Weight Regain.

Science.gov (United States)

Dunn, Carolyn; Haubenreiser, Megan; Johnson, Madison; Nordby, Kelly; Aggarwal, Surabhi; Myer, Sarah; Thomas, Cathy

2018-03-01

There is an urgent need for effective weight management techniques, as more than one third of US adults are overweight or obese. Recommendations for weight loss include a combination of reducing caloric intake, increasing physical activity, and behavior modification. Behavior modification includes mindful eating or eating with awareness. The purpose of this review was to summarize the literature and examine the impact of mindful eating on weight management. The practice of mindful eating has been applied to the reduction of food cravings, portion control, body mass index, and body weight. Past reviews evaluating the relationship between mindfulness and weight management did not focus on change in mindful eating as the primary outcome or mindful eating as a measured variable. This review demonstrates strong support for inclusion of mindful eating as a component of weight management programs and may provide substantial benefit to the treatment of overweight and obesity.

Complete proof systems for weighted modal logic

DEFF Research Database (Denmark)

Larsen, Kim G.; Mardare, Radu

2014-01-01

(WML) is a multi-modal logic that expresses qualitative and quantitative properties of WTSs. While WML has been studied in various contexts and for various application domains, no proof system has been developed for it. In this paper we solve this open problem and propose both weak-complete and strong......The weighted transition systems (WTS) considered in this paper are transition systems having both states and transitions labeled with real numbers: the state labels denote quantitative resources, while the transition labels denote costs of transitions in terms of resources. Weighted Modal Logic....... This work emphasizes a series of similarities between WML and the probabilistic/stochastic modal logics for Markov processes and Harsanyi type spaces, such as the use of particular infinitary rules to guarantee the strong-completeness....

Effect of manure and plants spacing on yield and flavonoid content of Elephantopus scaber L.

Science.gov (United States)

Riyana, D.; Widiyastuti, Y.; Widodo, H.; Purwanto, E.; Samanhudi

2018-03-01

This experiment is aimed to observe the growth and flavonoid contain of Tapak Liman (Elephantopus scaber L.) with different manure types and plants spacing treatment. This experiment is conducted at Tegal Gede Village, Karanganyar District on June until August 2016. The analysis of secondary metabolism was done in B2P2TOOT, Tawangamangu. This experiment is conducted with Randomized Complete Block Design (RCBD) with two treatment factors, those are manure and plants spacing. Animal manure treatment had 3 levels, those are without manure, cow manure with 20 ton/ha dose, and chicken manure with 20 ton/ha dose. Plants spacing treatment had 3 phrase, those are 20 cm × 20 cm; 30 × 30 cm; 40 cm × 40 cm. The result of this experiment shows that chicken manure with 20 ton/ha dosage increase the development of leaves’ lengthiness, header’s diameter, plant’s fresh weight, and plant’s dry weight. Plants spacing 40 cm × 40 cm increase for the development of leaves’ lengthiness, header’s diameter, plant’s wet weight, and plant’s dry weight. The combination between chicken manure with 20 ton/ha dose and plants spacing 40 cm × 40cm treatments show the highest amount of tapak liman extract and alleged having the biggest amount of flavonoid substance.

The multiplication operators on some analytic function spaces of the ...

Indian Academy of Sciences (India)

Given f ∈ E1(Bn) we still denote by f (ξ) (ξ ∈ Sn) its admissible limit at the boundary which exists a.e. A ... BMOA is a Banach space under the following norm: || f ||2 ..... The same inequalities hold when ga is replaced by fa by the same observations. ... The case of the Bloch space and the weighted Bloch space. As in the ...

Space power subsystem sizing

International Nuclear Information System (INIS)

Geis, J.W.

1992-01-01

This paper discusses a Space Power Subsystem Sizing program which has been developed by the Aerospace Power Division of Wright Laboratory, Wright-Patterson Air Force Base, Ohio. The Space Power Subsystem program (SPSS) contains the necessary equations and algorithms to calculate photovoltaic array power performance, including end-of-life (EOL) and beginning-of-life (BOL) specific power (W/kg) and areal power density (W/m 2 ). Additional equations and algorithms are included in the spreadsheet for determining maximum eclipse time as a function of orbital altitude, and inclination. The Space Power Subsystem Sizing program (SPSS) has been used to determine the performance of several candidate power subsystems for both Air Force and SDIO potential applications. Trade-offs have been made between subsystem weight and areal power density (W/m 2 ) as influenced by orbital high energy particle flux and time in orbit

A Sobolev-Type Upper Bound for Rates of Approximation by Linear Combinations of Heaviside Plane Waves

Czech Academy of Sciences Publication Activity Database

Kainen, P.C.; Kůrková, Věra; Vogt, A.

2007-01-01

Roč. 147, č. 1 (2007), s. 1-10 ISSN 0021-9045 R&D Projects: GA MŠk(CZ) 1M0567 Institutional research plan: CEZ:AV0Z10300504 Keywords : characteristic functions of closed half-spaces * perceptron neural networks * integral formulas * variation with respect to half-spaces * Radon transform * Gaussian function * rates of approximation Subject RIV: IN - Informatics, Computer Science Impact factor: 0.697, year: 2007

Critical spaces for quasilinear parabolic evolution equations and applications

Science.gov (United States)

Prüss, Jan; Simonett, Gieri; Wilke, Mathias

2018-02-01

We present a comprehensive theory of critical spaces for the broad class of quasilinear parabolic evolution equations. The approach is based on maximal Lp-regularity in time-weighted function spaces. It is shown that our notion of critical spaces coincides with the concept of scaling invariant spaces in case that the underlying partial differential equation enjoys a scaling invariance. Applications to the vorticity equations for the Navier-Stokes problem, convection-diffusion equations, the Nernst-Planck-Poisson equations in electro-chemistry, chemotaxis equations, the MHD equations, and some other well-known parabolic equations are given.

Holiday Weight Management by Successful Weight Losers and Normal Weight Individuals

Science.gov (United States)

Phelan, Suzanne; Wing, Rena R.; Raynor, Hollie A.; Dibello, Julia; Nedeau, Kim; Peng, Wanfeng

2008-01-01

This study compared weight control strategies during the winter holidays among successful weight losers (SWL) in the National Weight Control Registry and normal weight individuals (NW) with no history of obesity. SWL (n = 178) had lost a mean of 34.9 kg and had kept greater than or equal to 13.6 kg off for a mean of 5.9 years. NW (n = 101) had a…

On the solvability of Dirichlet problem for the weighted p-Laplacian

Directory of Open Access Journals (Sweden)

Ewa Szlachtowska

2012-01-01

Full Text Available The paper investigates the existence and uniqueness of weak solutions for a non-linear boundary value problem involving the weighted \\(p\\-Laplacian. Our approach is based on variational principles and representation properties of the associated spaces.

Conditions and constraints of food processing in space

Science.gov (United States)

Fu, B.; Nelson, P. E.; Mitchell, C. A. (Principal Investigator)

1994-01-01

Requirements and constraints of food processing in space include a balanced diet, food variety, stability for storage, hardware weight and volume, plant performance, build-up of microorganisms, and waste processing. Lunar, Martian, and space station environmental conditions include variations in atmosphere, day length, temperature, gravity, magnetic field, and radiation environment. Weightlessness affects fluid behavior, heat transfer, and mass transfer. Concerns about microbial behavior include survival on Martian and lunar surfaces and in enclosed environments. Many present technologies can be adapted to meet space conditions.

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Tallinna XI graafikatriennaal. Rotermanni soolaladu: "Puudutus"; Kunstihoone: "Puutujad"; Rahvusraamatukogu: Laste ja noorte graafikanäitus; Kastellaanimaja galerii: Wim Lamboo (s. 1949) "Eesti kunstnike portreed 1997" (fotograafia); Tallinna Botaanikaaed: "Maised rõõmud"; Rahvusraamatukogu: Antanas Sutkus (s. 1939) "Pro memoria" (fotograafia); Tammsaare majamuuseum: Eve Pärnaste "Ülelend" (maalid); Haapsalu Linnagalerii: Paul Allik "Seisundid" (aktimaalid).

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Vaal-galerii: Peeter Laurits "Taeva Atlas" (gigitaaltehnoloogias kollaazhid); Sammas-galerii: "Maailma nägu"; Tartu Kunstimaja: "Viljandi kunstipäevad Tartus"; Estonia Talveaed: Mall Mets&Erika Pedak "Due Canzoni" (vaibakunst).

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Kunstihoone ja Rotermanni soolaladu: "Kujundid, objektid, stseenid - vaatenurki prantsuse kunstile alates 1978. aastast"; Sammas-galerii: Tiiu Rebane ja Karl Nagel "Tänapäeva müüt"; Raatuse galerii: Elo Järv "Saavad uuteks liblikateks" (nahakunst); Tammsaare muuseum: "Mis jääb mällu" (sissevaade Saksamaa ajalukku ajavahemikul 1933-1949); Hotell "Olümpia" Forte saal: Gabor Dienesi personaalnäitus (maalid)

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Kunstihoone galerii: Juhani Harri (s. 1939). assamblaažid; Linnagalerii Tallinnas: 'Top Secret Art' & 'Eesti noored kunstnikud kunstikriitikutest'; Kastellaanimaja galerii: Virge Jõekalda. Graafika; Raamatupoed 'Areng' ja 'Kupar': 'Maalitupsud tulevad'(lastekunst algava kooliaasta teemal).

Klassika & ekskremendid / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

2002-01-01

20.-21. aprillil toimus Pärnus 8. Fideo- ja Vilmifestival alapealkirjaga "Eksperimendid ja klassika". Peakorraldaja Rael Artel. Rami Raski filmist "Legowitz 1999" (soome rühmitus Vivid), läti filmist "Love, death & television", Concordia ülikooli ("Ülemus") ja Academia Grata (portreefilmid Asta Isakist, Andrus Joonasest jm.) programmist, Kadriann Kibuse ja Liina Paakspuu filmist "Urban Obsessions", Mirja-Mari Smidti ja Allan Tõnissoo videost, Marianne Männi koomiksitest kataloogis

Hoolimine kohvris / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1999-01-01

Rahvusvaheline rändnäitus 'Suitcases' ('Kohvrid') Tallinna Kunstihoones. Tallinna näituse alateema on 'Who Cares?' ('Kelle asi?'). Näituse kuraator on soomlane Timo Mähonen. Eestit esindab näitusel kunstnik Helena Palm.

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Vaal galerii: Ruth Tulving 'Davise liblikad' (maalid); Tartu Kunstimaja: Tuuli Luukas 'Foto/Installatsioon/Näitus'; Rotermanni soolaladu/rõdugalerii: 'Norra arhitektuur 1990. aastatel'; Sammas-galerii: Ilmar Kruusamäe 'Inimene X'; Energeetikamuuseum: Loore Haab&Nina Piilonen.Graafikanäitus

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Rotermanni Soolaladu: "Cweesti" (maastikuarhitektuur- ruum mere ja maa piiril); Tarbekunstimuuseum: "Pro Arte" (soome nüüdisaegse käsitöö näitus); Linnagalerii Tallinnas: Eve Kask "29 1Ü2"; Sammas-galerii: Rene Kari maalid; Kunstihoone galerii: Anne Türn "Hundid" (keraamika); Tammsaare muuseum. Karl Manbergi maalid ja pisiplastika (1914 Tallinn - 1993 Sidney); Eesti Loodusmuuseum: Marielle Liiveti maalid ja kompositsioonid; Raatus-galerii. "Euroopa koolis".

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Raatuse galerii: Kiwa. "Muzik at Vremja of my Võhod"; Tarbekunstimuuseum: Malle Agabush "Valgusega ajast aega"; EKM Jõhvi filiaal: Eduard Ole 100. sünniaastapäeva näitus; Rahvusraamatukogu: Eesti Akvarellistide Ühenduse aastanäitus; Eesti Rahva Muuseum: "Tulest jäänu" ja "Post textile"; Sammas-galerii: Helmet Raja&Karl Martin Sinijärv

Kunst lillepeenras / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Rahvusvahelne skulptuurisümpoosion-workshop Tallinna Botaanikaaias 13.-27. sept. 1998, mille käigus valmis vabas õhus eksponeeritud näitus 'Maised rõõmud'. Üritusel valminud tööd olid installatsioonid ja performance'id. Kuraator Paul Rodgers.

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Rotermanni soolaladu. "Elektrokardiogramm" (tegevuskunsti üritus); Vaal-galerii. Antoni T̉pies "Litograafiaid aastatest 1973-1995"; Mari Kadanik, Eero Barndõk, Rain Ader "Pildid" (maalid); Paldiski Põhikool. "Niemenlautta ja Hugo Simbergi fotod" (soome kunstniku fotode koopiad, pildistatud enne 1915. a.; Kullo lastegalerii. Neli uut näitust.(lastekunst); Arhitektuurimuuseum. Arnold Matteus - Tartu linna arhitekt (juubelinäitus), Alvar Aalto "Kolm objekti Eestis"; Linnagalerii Tallinnas. "Valge" (ruumi- ja moekunsti näitus); Sammas-galerii. Jüri Jegorow "Insect" (arvutigraafika); Endla Teatri palmisaal. "Muzik in der Kunst" (Tallinna kunstitudengite näitus); Eesti Rahvusraamatukogu. Õie Kütt "Uued ja vanad ehted"

Näitused / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Rotermanni soolaladu: Mark Raidpere ja Ene-Liis Semper "Mäng 4. käel"; Kunstihoone: Tony Craggi skulptuurid; Adamson-Ericu muuseum: Eduard Ole 100. sünniaastapäevale pühendatud näitus; Kastellaanimaja galerii: "Tee Raamat": Anu Purre kirjutus-kunstistuudio EKSTEKST GRUPP ja stuudio sõprade näitus (T-särkidest raamat-installatsioonid); Tervishoiumuuseum: "In vino..."; Tammsaare muuseum:"Tiibeti muistne kultuur. Hiina maastikud"; Kullo galerii: Huvikeskuse Kullo aastanäitus.

A space-qualified experiment integrating HTS digital circuits and small cryocoolers

International Nuclear Information System (INIS)

Silver, A.; Akerling, G.; Auten, R.

1996-01-01

High temperature superconductors (HTS) promise to achieve electrical performance superior to that of conventional electronics. For application in space systems, HTS systems must simultaneously achieve lower power, weight, and volume than conventional electronics, and meet stringent space qualification and reliability requirements. Most effort to date has focused on passive RF/microwave applications. However, incorporation of active microwave components such as amplifiers, mixers, and phase shifters, and on-board high data rate digital signal processing is limited by the power and weight of their spacecraft electronic and support modules. Absence of data on active HTS components will prevent their utilization in space. To validate the feasibility in space of HTS circuits and components based on Josephson junctions, one needs to demonstrate HTS circuits and critical supporting technologies, such as space-qualified packaging and interconnects, closed-cycle cryocooling, and interface electronics. This paper describes the packaging, performance, and space test plan of an integrated, space-qualified experimental package consisting of HTS Josephson junction circuits and all the supporting components for NRL's high temperature superconductor space experiment (HTSSE-II). Most of the technical challenges and approaches are equally applicable to passive and active RF/microwave and digital electronic components, and this experiment will provide valuable validation data

Weight Optimization of Active Thermal Management Using a Novel Heat Pump

Science.gov (United States)

Lear, William E.; Sherif, S. A.

2004-01-01

Efficient lightweight power generation and thermal management are two important aspects for space applications. Weight is added to the space platforms due to the inherent weight of the onboard power generation equipment and the additional weight of the required thermal management systems. Thermal management of spacecraft relies on rejection of heat via radiation, a process that can result in large radiator mass, depending upon the heat rejection temperature. For some missions, it is advantageous to incorporate an active thermal management system, allowing the heat rejection temperature to be greater than the load temperature. This allows a reduction of radiator mass at the expense of additional system complexity. A particular type of active thermal management system is based on a thermodynamic cycle, developed by the authors, called the Solar Integrated Thermal Management and Power (SITMAP) cycle. This system has been a focus of the authors research program in the recent past (see Fig. 1). One implementation of the system requires no moving parts, which decreases the vibration level and enhances reliability. Compression of the refrigerant working fluid is accomplished in this scheme via an ejector.

Perturbative stability of the approximate Killing field eigenvalue problem

International Nuclear Information System (INIS)

Beetle, Christopher; Wilder, Shawn

2014-01-01

An approximate Killing field may be defined on a compact, Riemannian geometry by solving an eigenvalue problem for a certain elliptic operator. This paper studies the effect of small perturbations in the Riemannian metric on the resulting vector field. It shows that small metric perturbations, as measured using a Sobolev-type supremum norm on the space of Riemannian geometries on a fixed manifold, yield small perturbations in the approximate Killing field, as measured using a Hilbert-type square integral norm. It also discusses applications to the problem of computing the spin of a generic black hole in general relativity. (paper)

On a modified form of navier-stokes equations for three-dimensional flows.

Science.gov (United States)

Venetis, J

2015-01-01

A rephrased form of Navier-Stokes equations is performed for incompressible, three-dimensional, unsteady flows according to Eulerian formalism for the fluid motion. In particular, we propose a geometrical method for the elimination of the nonlinear terms of these fundamental equations, which are expressed in true vector form, and finally arrive at an equivalent system of three semilinear first order PDEs, which hold for a three-dimensional rectangular Cartesian coordinate system. Next, we present the related variational formulation of these modified equations as well as a general type of weak solutions which mainly concern Sobolev spaces.

Asymptotic behaviour of solutions of the first boundary-value problem for strongly hyperbolic systems near a conical point at the boundary of the domain

International Nuclear Information System (INIS)

Hung, Nguyen M

1999-01-01

An existence and uniqueness theorem for generalized solutions of the first initial-boundary-value problem for strongly hyperbolic systems in bounded domains is established. The question of estimates in Sobolev spaces of the derivatives with respect to time of the generalized solution is discussed. It is shown that the smoothness of generalized solutions with respect to time is independent of the structure of the boundary of the domain but depends on the coefficients of the right-hand side. Results on the smoothness of the generalized solution and its asymptotic behaviour in a neighbourhood of a conical boundary point are also obtained

Adaptive wavelet collocation methods for initial value boundary problems of nonlinear PDE's

Science.gov (United States)

Cai, Wei; Wang, Jian-Zhong

1993-01-01

We have designed a cubic spline wavelet decomposition for the Sobolev space H(sup 2)(sub 0)(I) where I is a bounded interval. Based on a special 'point-wise orthogonality' of the wavelet basis functions, a fast Discrete Wavelet Transform (DWT) is constructed. This DWT transform will map discrete samples of a function to its wavelet expansion coefficients in O(N log N) operations. Using this transform, we propose a collocation method for the initial value boundary problem of nonlinear PDE's. Then, we test the efficiency of the DWT transform and apply the collocation method to solve linear and nonlinear PDE's.

Explicit Finite Difference Methods for the Delay Pseudoparabolic Equations

Directory of Open Access Journals (Sweden)

I. Amirali

2014-01-01

Full Text Available Finite difference technique is applied to numerical solution of the initial-boundary value problem for the semilinear delay Sobolev or pseudoparabolic equation. By the method of integral identities two-level difference scheme is constructed. For the time integration the implicit rule is being used. Based on the method of energy estimates the fully discrete scheme is shown to be absolutely stable and convergent of order two in space and of order one in time. The error estimates are obtained in the discrete norm. Some numerical results confirming the expected behavior of the method are shown.

A numerical method for finding sign-changing solutions of superlinear Dirichlet problems

Energy Technology Data Exchange (ETDEWEB)

Neuberger, J.M.

1996-12-31

In a recent result it was shown via a variational argument that a class of superlinear elliptic boundary value problems has at least three nontrivial solutions, a pair of one sign and one which sign changes exactly once. These three and all other nontrivial solutions are saddle points of an action functional, and are characterized as local minima of that functional restricted to a codimension one submanifold of the Hilbert space H-0-1-2, or an appropriate higher codimension subset of that manifold. In this paper, we present a numerical Sobolev steepest descent algorithm for finding these three solutions.

Marital status and body weight, weight perception, and weight management among U.S. adults.

Science.gov (United States)

Klos, Lori A; Sobal, Jeffery

2013-12-01

Married individuals often have higher body weights than unmarried individuals, but it is unclear how marital roles affect body weight-related perceptions, desires, and behaviors. This study analyzed cross-sectional data for 4,089 adult men and 3,989 adult women using multinomial logistic regression to examine associations between marital status, perceived body weight, desired body weight, and weight management approach. Controlling for demographics and current weight, married or cohabiting women and divorced or separated women more often perceived themselves as overweight and desired to weigh less than women who had never married. Marital status was unrelated to men's weight perception and desired weight change. Marital status was also generally unrelated to weight management approach, except that divorced or separated women were more likely to have intentionally lost weight within the past year compared to never married women. Additionally, never married men were more likely to be attempting to prevent weight gain than married or cohabiting men and widowed men. Overall, married and formerly married women more often perceived themselves as overweight and desired a lower weight. Men's marital status was generally unassociated with weight-related perceptions, desires, and behaviors. Women's but not men's marital roles appear to influence their perceived and desired weight, suggesting that weight management interventions should be sensitive to both marital status and gender differences. © 2013 Elsevier Ltd. All rights reserved.

Effects of Weight Hourly Space Velocity and Catalyst Diameter on Performance of Hybrid Catalytic-Plasma Reactor for Biodiesel Synthesis over Sulphated Zinc Oxide Acid Catalyst

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Luqman Buchori

2017-05-01

Full Text Available Biodiesel synthesis through transesterification of soybean oil with methanol on hybrid catalytic-plasma reactor over sulphated zinc oxide (SO42-/ZnO active acid catalyst was investigated. This research was aimed to study effects of Weight Hourly Space Velocity (WHSV and the catalyst diameter on performance of the hybrid catalytic-plasma reactor for biodiesel synthesis. The amount (20.2 g of active sulphated zinc oxide solid acid catalysts was loaded into discharge zone of the reactor. The WHSV and the catalyst diameter were varied between 0.89 to 1.55 min-1 and 3, 5, and 7 mm, respectively. The molar ratio of methanol to oil as reactants of 15:1 is fed to the reactor, while operating condition of the reactor was kept at reaction temperature of 65 oC and ambient pressure. The fatty acid methyl ester (FAME component in biodiesel product was identified by Gas Chromatography - Mass Spectrometry (GC-MS. The results showed that the FAME yield decreases with increasing WHSV. It was found that the optimum FAME yield was achieved of 56.91 % at WHSV of 0.89 min-1 and catalyst diameter of 5 mm and reaction time of 1.25 min. It can be concluded that the biodiesel synthesis using the hybrid catalytic-plasma reactor system exhibited promising the FAME yield. Copyright © 2017 BCREC Group. All rights reserved Received: 15th November 2016; Revised: 24th December 2016; Accepted: 16th February 2017 How to Cite: Buchori, L., Istadi, I., Purwanto, P. (2017. Effects of Weight Hourly Space Velocity and Catalyst Diameter on Performance of Hybrid Catalytic-Plasma Reactor for Biodiesel Synthesis over Sulphated Zinc Oxide Acid Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2: 227-234 (doi:10.9767/bcrec.12.2.775.227-234 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.775.227-234

Light-Weight, Flexible, High Efficiency Vacuum Photo-Thermo-Voltaic Solar Cells, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Conventional solar cells are limited in efficiency, require heavy weight for high power applications, and tend to degrade rapidly in the harsh radiation environment...

A REVIEW ON TEXTILES IN SPACE PROTECTION EQUIPMENTS

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SUNTER EROGLU Nilsen

2017-05-01

Full Text Available Astronauts need the lander for decelerate and bridle the speed when they land on the space surface slowly. This lander could be controlled velocity magnitude in any direction or orientation and provide protection. The landers consist of airbags and parachutes. The airbag is a type of vehicle safety device, have a soft cushioning and is an occupant restraint system. The parachute provides to slow the motion of an object through an atmosphere by the hauling. Space protection equipments must have some properties because of astronaut’s entry, descend and landing in safely. Textiles in airbags provide these properties especially which are light weight, low gas permeability, high strength, low cost, low temperature flexibility and low coefficient of friction. For textiles in parachutes must have properties such as smooth, porosity, air permeability, high strength, cost-effective, stability light weight and good in drag and lift. Airbags and parachutes in space protection equipment’s are improved in systems provide easy stability. Recently, inflatable technologies for space protection equipments plays a fundamental role in building re-entry capsule. It can be performed a variety of pre-flight analyses to ensure the success of the tests of protection systems from day to day. In this review, space protection systems, their textile materials and properties, their advantages and disadvantages are presented.

Empirical study on a directed and weighted bus transport network in China

Science.gov (United States)

Feng, Shumin; Hu, Baoyu; Nie, Cen; Shen, Xianghao

2016-01-01

Bus transport networks are directed complex networks that consist of routes, stations, and passenger flow. In this study, the concept of duplication factor is introduced to analyze the differences between uplinks and downlinks for the bus transport network of Harbin (BTN-H). Further, a new representation model for BTNs is proposed, named as directed-space P. Two empirical characteristics of BTN-H are reported in this paper. First, the cumulative distributions of weighted degree, degree, number of routes that connect to each station, and node weight (peak-hour trips at a station) uniformly follow the exponential law. Meanwhile, the node weight shows positive correlations with the corresponding weighted degree, degree, and number of routes that connect to a station. Second, a new richness parameter of a node is explored by its node weight and the connectivity, weighted connectivity, average shortest path length and efficiency between rich nodes can be fitted by composite exponential functions to demonstrate the rich-club phenomenon.

The Navier-Stokes equations an elementary functional analytic approach

CERN Document Server

Sohr, Hermann

2001-01-01

The primary objective of this monograph is to develop an elementary and self­ contained approach to the mathematical theory of a viscous incompressible fluid in a domain 0 of the Euclidean space ]Rn, described by the equations of Navier­ Stokes. The book is mainly directed to students familiar with basic functional analytic tools in Hilbert and Banach spaces. However, for readers' convenience, in the first two chapters we collect without proof some fundamental properties of Sobolev spaces, distributions, operators, etc. Another important objective is to formulate the theory for a completely general domain O. In particular, the theory applies to arbitrary unbounded, non-smooth domains. For this reason, in the nonlinear case, we have to restrict ourselves to space dimensions n = 2,3 that are also most significant from the physical point of view. For mathematical generality, we will develop the lin­ earized theory for all n 2 2. Although the functional-analytic approach developed here is, in principle, known ...

On existence and multiplicity for Schrödinger–Poisson systems involving weighted sublinear nonlinearities

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Sara Barile

2017-04-01

where $V, K: \\mathbb{R}^3 \\rightarrow \\mathbb{R}^+$ are suitable potentials and $f: \\mathbb{R}^3 \\times \\mathbb{R} \\rightarrow \\mathbb{R}$ satisfies sublinear growth assumptions involving a finite number of positive weights $W_i$, $i= 1,\\dots,r$ with $r \\geq 1$. By exploiting compact embeddings of the functional space on which we work in every weighted space $L_{W_i}^{w_i}(\\mathbb{R}^3$, $w_i \\in (1, 2$, we establish existence by means of a generalized Weierstrass theorem. Moreover, we prove multiplicity of solutions if $f$ is odd in $u$ and $g(x \\equiv 0$ thanks to a variant of the symmetric mountain pass theorem stated by R. Kajikiya for subquadratic functionals.

Characterisation of Embeddings in Lorentz Spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Johansson, M.; Okpoti, C.A.; Persson, L. E.

2007-01-01

Roč. 76, č. 1 (2007), s. 69-92 ISSN 0004-9727 R&D Projects: GA ČR GA201/05/2033 Institutional research plan: CEZ:AV0Z10190503 Keywords : non-increasing rearrangement * Lorentz spaces * weights Subject RIV: BA - General Mathematics Impact factor: 0.297, year: 2007

Weighted asymptotic behavior of solutions to semilinear integro-differential equations in Banach spaces

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Yan-Tao Bian

2014-04-01

Full Text Available In this article, we study weighted asymptotic behavior of solutions to the semilinear integro-differential equation $$ u'(t=Au(t+\\alpha\\int_{-\\infty}^{t}e^{-\\beta(t-s}Au(sds+f(t,u(t, \\quad t\\in \\mathbb{R}, $$ where $\\alpha, \\beta \\in \\mathbb{R}$, with $\\beta > 0, \\alpha \

Bloch spaces of holomorphic functions in the polydisk

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Anahit Harutyunyan

2007-01-01

Full Text Available This work is an introduction to anisotropic spaces of holomorphic functions, which have ω-weight and are generalizations of Bloch spaces to a polydisc. We prove that these classes form an algebra and are invariant with respect to monomial multiplication. Some theorems on projection and diagonal mapping are proved. We establish a description of (Ap(ω* (or (Hp(ω* via the Bloch classes for all 0

Weight Analysis of Two-Stage-To-Orbit Reusable Launch Vehicles for Military Applications

National Research Council Canada - National Science Library

Caldwell, Richard A

2005-01-01

In response to Department of Defense (DoD) requirements for responsive and low-cost space access, this design study provides an objective empty weight analysis of potential reusable launch vehicle (RLV) configurations...

Séminaire de probabilités XXXVI

CERN Document Server

Émery, Michel; Ledoux, Michel; Yor, Marc

2003-01-01

The 36th Séminaire de Probabilités contains an advanced course on Logarithmic Sobolev Inequalities by A. Guionnet and B. Zegarlinski, as well as two shorter surveys by L. Pastur and N. O'Connell on the theory of random matrices and their links with stochastic processes. The main themes of the other contributions are Logarithmic Sobolev Inequalities, Stochastic Calculus, Martingale Theory and Filtrations. Besides the traditional readership of the Séminaires, this volume will be useful to researchers in statistical mechanics and mathematical finance.

Vehicle Maximum Weight Limitation Based on Intelligent Weight Sensor

Science.gov (United States)

Raihan, W.; Tessar, R. M.; Ernest, C. O. S.; E Byan, W. R.; Winda, A.

2017-03-01

Vehicle weight is an important factor to be maintained for transportation safety. A weight limitation system is proposed to make sure the vehicle weight is always below its designation prior the vehicle is being used by the driver. The proposed system is divided into two systems, namely vehicle weight confirmation system and weight warning system. In vehicle weight confirmation system, the weight sensor work for the first time after the ignition switch is turned on. When the weight is under the weight limit, the starter engine can be switched on to start the engine system, otherwise it will be locked. The seconds system, will operated after checking all the door at close position, once the door of the car is closed, the weight warning system will check once again the weight during runing engine condition. The results of these two systems, vehicle weight confirmation system and weight warning system have 100 % accuracy, respectively. These show that the proposed vehicle weight limitation system operate well.

Finding Non-Zero Stable Fixed Points of the Weighted Kuramoto model is NP-hard

OpenAIRE

Taylor, Richard

2015-01-01

The Kuramoto model when considered over the full space of phase angles [$0,2\\pi$) can have multiple stable fixed points which form basins of attraction in the solution space. In this paper we illustrate the fundamentally complex relationship between the network topology and the solution space by showing that determining the possibility of multiple stable fixed points from the network topology is NP-hard for the weighted Kuramoto Model. In the case of the unweighted model this problem is shown...

Aluminum-Lithium Alloy 2050 for Reduced-Weight, Increased-Stiffness Space Structures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Touchstone Research Laboratory, along with Alcan Rolled Products -- Ravenswood WV, has identified the Aluminum-Lithium Alloy 2050 as a potentially game-changing...

Mechanisms of Weight Regain following Weight Loss.

Science.gov (United States)

Blomain, Erik Scott; Dirhan, Dara Anne; Valentino, Michael Anthony; Kim, Gilbert Won; Waldman, Scott Arthur

2013-01-01

Obesity is a world-wide pandemic and its incidence is on the rise along with associated comorbidities. Currently, there are few effective therapies to combat obesity. The use of lifestyle modification therapy, namely, improvements in diet and exercise, is preferable over bariatric surgery or pharmacotherapy due to surgical risks and issues with drug efficacy and safety. Although they are initially successful in producing weight loss, such lifestyle intervention strategies are generally unsuccessful in achieving long-term weight maintenance, with the vast majority of obese patients regaining their lost weight during followup. Recently, various compensatory mechanisms have been elucidated by which the body may oppose new weight loss, and this compensation may result in weight regain back to the obese baseline. The present review summarizes the available evidence on these compensatory mechanisms, with a focus on weight loss-induced changes in energy expenditure, neuroendocrine pathways, nutrient metabolism, and gut physiology. These findings have added a major focus to the field of antiobesity research. In addition to investigating pathways that induce weight loss, the present work also focuses on pathways that may instead prevent weight regain. Such strategies will be necessary for improving long-term weight loss maintenance and outcomes for patients who struggle with obesity.

Postero-anterior radiogram of the knee in weight-bearing and semiflexion. Comparison with MR imaging

International Nuclear Information System (INIS)

Boegaard, T.; Rudling, O.; Sanfridsson, J.; Jonsson, K.; Saxne, T.; Svensson, B.

1997-01-01

Purpose: The purpose was four-fold: to assess the reproducibility of p.a. weight-bearing radiograms of the knee and the minimal joint-space (MJS) width measurements in these radiograms; to compare the MJS with MR-detected cartilage defects; to evaluate the location of these cartilage defects; and to estimate the relation between meniscal abnormalities and joint-space narrowing. Material and Methods: Fifty-nine individuals, aged 41-58 years (mean 50), with chronic knee pain were examined by means of p.a. weight-bearing radiograms in semiflexion with fluoroscopic guidance of the knee joint. The MJS was measured with a standard ruler. On the same day MR imaging was performed with proton-density- and T2-weighted turbo spin-echo on a 1.0 T imager. Meniscal abnormalities and cartilage defects in the tibiofemoral joint (TFJ) were noted. Results and Conclusion: The p.a. view of the knee and the MJS measurements were reproducible. MJS of 3 mm is a limit in diagnosing joint-space narrowing in knees with MR-detected cartilage defects. There was a high proportion (p<0.001) of meniscal abnormality within the narrowed compartments in comparison with those that were not narrowed. A larger number of the cartilage defects (p<0.05) was found in the medial femoral condyle than in any of the other condyles of the TFJ. The defects had a dorsal location (p<0.001) as shown in the weight-bearing radiograms of the knee in semiflexion. (orig.)

Low Molecular Weight Z-Tetraol Boundary Lubricant Films in Hard Disk Drives

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R. J. Waltman

2012-01-01

Full Text Available Lower molecular weight Z-Tetraol films exhibit increased mechanical spacing in the slider-disk interface due to a lower z-profile. An increased resistance to lubricant disturbance on the disk surface (e.g., lube moguls with decreasing film thickness is attributed to an increasing contribution from the polar component of the disjoining pressure. Evaporative loss at temperatures typically encountered in a hard-disk drive also increases with decreasing molecular weight but is strongly dependent on the initial bonded fraction.

Convexity and concavity constants in Lorentz and Marcinkiewicz spaces

Science.gov (United States)

Kaminska, Anna; Parrish, Anca M.

2008-07-01

We provide here the formulas for the q-convexity and q-concavity constants for function and sequence Lorentz spaces associated to either decreasing or increasing weights. It yields also the formula for the q-convexity constants in function and sequence Marcinkiewicz spaces. In this paper we extent and enhance the results from [G.J.O. Jameson, The q-concavity constants of Lorentz sequence spaces and related inequalities, Math. Z. 227 (1998) 129-142] and [A. Kaminska, A.M. Parrish, The q-concavity and q-convexity constants in Lorentz spaces, in: Banach Spaces and Their Applications in Analysis, Conference in Honor of Nigel Kalton, May 2006, Walter de Gruyter, Berlin, 2007, pp. 357-373].

Criterion for the nuclearity of spaces of functions of infinite number of variables

International Nuclear Information System (INIS)

Gali, I.M.

1977-08-01

The paper formulates a new necessary and sufficient condition for the nuclearity of spaces of infinite number of variables, and defines new nuclear spaces which play an important role in the field of functional analysis and quantum field theory. Also the condition for nuclearity of the infinite weighted tensor product of nuclear spaces is given

(Dis-)solving the Weight Problem in Binge-Eating Disorder: Systemic Insights From Three Treatment Contexts With Weight Stability, Weight Loss, and Weight Acceptance.

Science.gov (United States)

Meyer, Lene Bomholt; Waaddegaard, Mette; Lau, Marianne Engelbrecht; Tjørnhøj-Thomsen, Tine

2018-04-01

Binge-eating disorder (BED) is a severe eating disorder strongly associated with obesity. Treatments struggle to provide safe and effective ways of addressing weight in a BED context. This study explored a two-phased treatment for BED developed at a major out-patient eating disorder service in Denmark. The study used interviews and participant observations to gain insight into experiences and processes related to weight and body issues in three treatment contexts that addressed weight stability, weight acceptance, and weight loss. Using systems theory, the study proposed a relational weight problem that embeds feelings of non-acceptance due to weight, a merge of weight and identity, and an internalized body- and weight-critical gaze of others. Contrary to critical claims that weight acceptance discourages people with obesity from engaging in weight loss efforts, this study suggests that acceptance and a disentanglement of weight and identity are prerequisites for weight loss for this group.

Weight savings in aerospace vehicles through propellant scavenging

Science.gov (United States)

Schneider, Steven J.; Reed, Brian D.

1988-01-01

Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

Weight savings in aerospace vehicles through propellant scavenging

Science.gov (United States)

Schneider, Steven J.; Reed, Brian D.

1988-05-01

Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

Infrared Free Space Communication - The Autonomous Testing of Free Space Infrared Communication

Science.gov (United States)

Heldman, Christopher

2017-01-01

Fiber optics has been a winning player in the game of high-speed communication and data transfer in cable connections. Yet, in free space RF has been the repeated choice of communication medium of the space industry. Investigating the benefits of free space optical communication over radio frequency is worthwhile. An increase in science data rate return capabilities could occur if optical communication is implemented. Optical communication systems also provide efficiencies in power, mass, and volume over RF systems1. Optical communication systems have been demonstrated from a satellite in orbit with the moon to earth, and resulted in the highest data rates ever seen through space (622Mbps)2. Because of these benefits, optical communication is far superior to RF. The HiDRA (High Data Rate Architecture) project is researching Passive Misalignment Mitigation of Dynamic Free Apace Optical Communication Links. The goal of this effort is to enable gigabit per second transmission of data in short range dynamic links (less than 100 meters). In practice this would enhance data rates between sites on the International Space Station with minimal size, weight, and power requirements. This paper will focus on an autonomous code and a hardware setup that will be used to fulfill the next step in the research being conducted. The free space optical communications pointing downfalls will be investigated. This was achieved by creating 5 python programs and a top-level code to automate this test.

Weight suppression predicts total weight gain and rate of weight gain in outpatients with anorexia nervosa.

Science.gov (United States)

Carter, Frances A; Boden, Joseph M; Jordan, Jennifer; McIntosh, Virginia V W; Bulik, Cynthia M; Joyce, Peter R

2015-11-01

The present study sought to replicate the finding of Wildes and Marcus, Behav Res Ther, 50, 266-274, 2012 that higher levels of weight suppression at pretreatment predict greater total weight gain, faster rate of weight gain, and bulimic symptoms amongst patients admitted with anorexia nervosa. Participants were 56 women with anorexia nervosa diagnosed by using strict or lenient weight criteria, who were participating in a randomized controlled psychotherapy trial (McIntosh et al., Am J Psychiatry, 162, 741-747, 2005). Thirty-five women completed outpatient treatment and post-treatment assessment. Weight suppression was the discrepancy between highest lifetime weight at adult height and weight at pretreatment assessment. Outcome variables were total weight gain, rate of weight gain, and bulimic symptoms in the month prior to post-treatment assessment [assessed using the Eating Disorders Examination (Fairburn et al., Binge-Eating: Nature, Assessment and Treatment. New York: Guilford, 1993)]. Weight suppression was positively associated with total weight gain and rate of weight gain over treatment. Regression models showed that this association could not be explained by covariates (age at onset of anorexia nervosa and treatment modality). Weight suppression was not significantly associated with bulimic symptoms in the month prior to post-treatment assessment, regardless of whether bulimic symptoms were examined as continuous or dichotomous variables. The present study reinforces the previous finding that weight suppression predicts total weight gain and rate of weight gain amongst patients being treated for anorexia nervosa. Methodological issues may explain the failure of the present study to find that weight suppression predicts bulimic symptoms. Weight suppression at pretreatment for anorexia nervosa should be assessed routinely and may inform treatment planning. © 2015 Wiley Periodicals, Inc.

The experience of weight management in normal weight adults.

Science.gov (United States)

Hernandez, Cheri Ann; Hernandez, David A; Wellington, Christine M; Kidd, Art

2016-11-01

No prior research has been done with normal weight persons specific to their experience of weight management. The purpose of this research was to discover the experience of weight management in normal weight individuals. Glaserian grounded theory was used. Qualitative data (focus group) and quantitative data (food diary, study questionnaire, and anthropometric measures) were collected. Weight management was an ongoing process of trying to focus on living (family, work, and social), while maintaining their normal weight targets through five consciously and unconsciously used strategies. Despite maintaining normal weights, the nutritional composition of foods eaten was grossly inadequate. These five strategies can be used to develop new weight management strategies that could be integrated into existing weight management programs, or could be developed into novel weight management interventions. Surprisingly, normal weight individuals require dietary assessment and nutrition education to prevent future negative health consequences. Copyright © 2016 Elsevier Inc. All rights reserved.

Handling Dynamic Weights in Weighted Frequent Pattern Mining

Science.gov (United States)

Ahmed, Chowdhury Farhan; Tanbeer, Syed Khairuzzaman; Jeong, Byeong-Soo; Lee, Young-Koo

Even though weighted frequent pattern (WFP) mining is more effective than traditional frequent pattern mining because it can consider different semantic significances (weights) of items, existing WFP algorithms assume that each item has a fixed weight. But in real world scenarios, the weight (price or significance) of an item can vary with time. Reflecting these changes in item weight is necessary in several mining applications, such as retail market data analysis and web click stream analysis. In this paper, we introduce the concept of a dynamic weight for each item, and propose an algorithm, DWFPM (dynamic weighted frequent pattern mining), that makes use of this concept. Our algorithm can address situations where the weight (price or significance) of an item varies dynamically. It exploits a pattern growth mining technique to avoid the level-wise candidate set generation-and-test methodology. Furthermore, it requires only one database scan, so it is eligible for use in stream data mining. An extensive performance analysis shows that our algorithm is efficient and scalable for WFP mining using dynamic weights.

The effect of holiday weight gain on body weight.

Science.gov (United States)

Schoeller, Dale A

2014-07-01

The topic of holiday weight gain has been a frequent subject of the lay media; however, scientific interest has only been recent. Multiple studies in Western societies have reported average weight gains among adults during the period between mid-November and mid-January that were about 0.5 kg. The range in individual weight changes was large, however, and the already overweight and obese gain more weight than those who are healthy weight. When the average gain across the year was also measured, the holiday weight was the major contributor to annual excess weight gain. Efforts patterned to increase awareness to energy balance and body weight have been shown to be successful at reducing such gain. An exception to holiday weight gain being a major contributor to annual excess gain has been children, in whom summer weight gains have been observed to be the major contributor to average excess weight gain. Copyright © 2014 Elsevier Inc. All rights reserved.

Weighted statistical parameters for irregularly sampled time series

Science.gov (United States)

Rimoldini, Lorenzo

2014-01-01

Unevenly spaced time series are common in astronomy because of the day-night cycle, weather conditions, dependence on the source position in the sky, allocated telescope time and corrupt measurements, for example, or inherent to the scanning law of satellites like Hipparcos and the forthcoming Gaia. Irregular sampling often causes clumps of measurements and gaps with no data which can severely disrupt the values of estimators. This paper aims at improving the accuracy of common statistical parameters when linear interpolation (in time or phase) can be considered an acceptable approximation of a deterministic signal. A pragmatic solution is formulated in terms of a simple weighting scheme, adapting to the sampling density and noise level, applicable to large data volumes at minimal computational cost. Tests on time series from the Hipparcos periodic catalogue led to significant improvements in the overall accuracy and precision of the estimators with respect to the unweighted counterparts and those weighted by inverse-squared uncertainties. Automated classification procedures employing statistical parameters weighted by the suggested scheme confirmed the benefits of the improved input attributes. The classification of eclipsing binaries, Mira, RR Lyrae, Delta Cephei and Alpha2 Canum Venaticorum stars employing exclusively weighted descriptive statistics achieved an overall accuracy of 92 per cent, about 6 per cent higher than with unweighted estimators.

Financial Time Series Forecasting Using Directed-Weighted Chunking SVMs

Directory of Open Access Journals (Sweden)

Yongming Cai

2014-01-01

Full Text Available Support vector machines (SVMs are a promising alternative to traditional regression estimation approaches. But, when dealing with massive-scale data set, there exist many problems, such as the long training time and excessive demand of memory space. So, the SVMs algorithm is not suitable to deal with financial time series data. In order to solve these problems, directed-weighted chunking SVMs algorithm is proposed. In this algorithm, the whole training data set is split into several chunks, and then the support vectors are obtained on each subset. Furthermore, the weighted support vector regressions are calculated to obtain the forecast model on the new working data set. Our directed-weighted chunking algorithm provides a new method of support vectors decomposing and combining according to the importance of chunks, which can improve the operation speed without reducing prediction accuracy. Finally, IBM stock daily close prices data are used to verify the validity of the proposed algorithm.

Optimization of vehicle weight for Mars excursion missions

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Ferebee, Melvin J., Jr.

1991-01-01

The excursion class mission to Mars is defined as a mission with one year durations coupled with a stay time of up to 30 days. The fuel budget for such a mission is investigated. The overall figure of merit in such an assessment is the vehicle weight ratio, the ratio between the wet vehicle weight to the dry vehicle weight. It is necessary to minimize the overall fuel budget for the mission in order to maximize the benefits that could be obtained by sending humans to Mars. Assumptions used in the analysis are: each mission will depart and terminate in low-earth-orbit (LEO) (500 km circular) and the maximum stay time at Mars is 30 days. The maximum mission duration is one year (355-375 days). The mass returned to LEO is 135,000 kg, the dropoff mass left at Mars is 168,000 kg. Three propulsive techniques for atmospheric interface are investigated: aerobraking, all-chemical propulsion, and nuclear thermal propulsion. By defining the fuel requirements, the space transfer vehicle's configuration is defined.

Research on Retro-reflecting Modulation in Space Optical Communication System

Science.gov (United States)

Zhu, Yifeng; Wang, Guannan

2018-01-01

Retro-reflecting modulation space optical communication is a new type of free space optical communication technology. Unlike traditional free space optical communication system, it applys asymmetric optical systems to reduce the size, weight and power consumption of the system and can effectively solve the limits of traditional free space optical communication system application, so it can achieve the information transmission. This paper introduces the composition and working principle of retro-reflecting modulation optical communication system, analyzes the link budget of this system, reviews the types of optical system and optical modulator, summarizes this technology future research direction and application prospects.

[Motivation for weight loss among weight loss treatment participants].

Science.gov (United States)

Czeglédi, Edit

2017-12-01

Unrealistic expectations about weight goal and about weight loss-related benefits can hinder the effort for a successful long-term weight control. To explore weight loss-related goals and their background among overweight/obese patients. Study sample consisted of patients who participated in the inpatient weight loss treatment in the Lipidological Department of Szent Imre Hospital (n = 339, 19% men). Mean age: 50.2 years (SD = 13.47 years), mean BMI: 38.6 (SD = 7.58). self-reported anthropometric data, type and number of treated illnesses, Goals and Relative Weights Questionnaire, Motivations for Weight Loss Scale, Body Shape Questionnaire. Participants would feel disappointed with a possible 10% weight loss in a half-year time span. The acceptable weight loss percentage was higher among women, younger participants and among those who had more excess weight. Motivation regarding the increase in social desirability by weight loss is in association with body dissatisfaction, health related motivation is in association with the number of treated illnesses. Our results are contributing to the understanding of motivational factors behind weight reduction efforts, considering these can improve treatment success rates. Orv Hetil. 2017; 158(49): 1960-1967.

Early weight loss predicts weight loss treatment response regardless of binge-eating disorder status and pretreatment weight change.

Science.gov (United States)

Barnes, Rachel D; Ivezaj, Valentina; Pittman, Brian P; Grilo, Carlos M

2018-04-10

Individuals seeking weight loss treatment have diverse pretreatment weight trajectories, and once enrolled, individuals' response to weight loss treatments also varies greatly and may be influenced by the presence of binge-eating disorder (BED). Reported average weight losses may obscure these considerable differences. This study examined whether BED status and different weight-related change variables are associated with successful weight loss treatment outcomes in a controlled treatment study. Participants (N = 89) with overweight/obesity, with and without BED, participated in a 3-month weight loss trial in primary care with 3- and 12-month follow-ups. We tested the prognostic significance of four weight-related change variables (the last supper, early weight loss, pretreatment weight trajectory, weight suppression) on outcomes (weight loss-overall, weight loss-"subsequent," weight loss during second half of treatment). Early weight loss was positively associated with weight loss-overall at post-treatment, and at 3-month and 12-month follow-up. Early weight loss was positively associated with weight loss-subsequent at post-treatment only. No other weight-related variables were significantly associated with weight loss. Models including BED status and treatment condition were not significant. Participants with early weight loss were more likely to continue losing weight, regardless of BED status or treatment condition. The results highlight the importance of early dedication to weight loss treatment to increase the likelihood of positive outcomes. © 2018 Wiley Periodicals, Inc.

Effect of space allowance and floor type on performance, welfare and physiological measurements of finishing beef heifers.

Science.gov (United States)

Keane, M P; McGee, M; O'Riordan, E G; Kelly, A K; Earley, B

2017-12-01

Accommodating cattle indoors during the winter is widely practiced throughout Europe. There is currently no legislation surrounding the space allowance and floor type that should be provided to cattle during this time, however, concerns have been raised regarding the type of housing systems currently in use. The objective of the study was to investigate the effect of space allowance and floor type on performance and welfare of finishing beef heifers. Continental crossbred heifers (n=240: mean initial live; weight, 504 (SD 35.8) kg) were blocked by breed, weight and age and randomly assigned to one of four treatments; (i) 3.0 m2, (ii) 4.5 m2 and (iii) 6.0 m2 space allowance per animal on a fully slatted concrete floor and (iv) 6.0 m2 space allowance per animal on a straw-bedded floor, for 105 days. Heifers were offered a total mixed ration ad libitum. Dry matter intake was recorded on a pen basis and refusals were weighed back twice weekly. Heifers were weighed, dirt scored and blood sampled every 3 weeks. Whole blood was analysed for complete cell counts and serum samples were assayed for metabolite concentrations. Behaviour was recorded continuously using IR cameras from days 70 to 87. Heifers' hooves were inspected for lesions at the start of the study and again after slaughter. Post-slaughter, carcass weight, conformation and fat scores and hide weight were recorded. Heifers housed at 4.5 m2 had a greater average daily live weight gain (ADG) than those on both of the other concrete slat treatments; however, space allowance had no effect on carcass weight. Heifers accommodated on straw had a greater ADG (0.15 kg) (PSpace allowance and floor type had no effect on the number of hoof lesions gained or on any of the haematological or metabolic variables measured. It was concluded that increasing space allowance above 3.0 m2/animal on concrete slats was of no benefit to animal performance but it did improve animal cleanliness. Housing heifers on straw instead of

Analysis of Vertical Weighting Functions for Lidar Measurements of Atmospheric CO2 and O2

Science.gov (United States)

Kooi, S.; Mao, J.; Abshire, J. B.; Browell, E. V.; Weaver, C. J.; Kawa, S. R.

2011-12-01

Several NASA groups have developed integrated path differential absorption (IPDA) lidar approaches to measure atmospheric CO2 concentrations from space as a candidates for NASA's ASCENDS space mission. For example, the Goddard CO2 Sounder approach uses two pulsed lasers to simultaneously measure both CO2 and O2 absorption in the vertical path to the surface at a number of wavelengths across a CO2 line near 1572 nm and an O2 line doublet near 764 nm. The measurements of CO2 and O2 absorption allow computing their vertically weighted number densities and then their ratios for estimating CO2 concentration relative to dry air. Since both the CO2 and O2 densities and their absorption line-width decrease with altitude, the absorption response (or weighting function) varies with both altitude and absorption wavelength. We have used some standard atmospheres and HITRAN 2008 spectroscopy to calculate the vertical weighting functions for two CO2 lines near 1571 nm and the O2 lines near 764.7 and 1260 nm for candidate online wavelength selections for ASCENDS. For CO2, the primary candidate on-line wavelengths are 10-12 pm away from line center with the weighting function peaking in the atmospheric boundary layer to measure CO2 sources and sinks at the surface. Using another on-line wavelength 3-5 pm away from line center allows the weighting function to peak in the mid- to upper troposphere, which is sensitive to CO2 transport in the free atmosphere. The Goddard CO2 sounder team developed an airborne precursor version of a space instrument. During the summers of 2009, 2010 and 2011 it has participated in airborne measurement campaigns over a variety of different sites in the US, flying with other NASA ASCENDS lidar candidates along with accurate in-situ atmospheric sensors. All flights used altitude patterns with measurements at steps in altitudes between 3 and 13 km, along with spirals from 13 km altitude to near the surface. Measurements from in-situ sensors allowed an

A finite-dimensional reduction method for slightly supercritical elliptic problems

Directory of Open Access Journals (Sweden)

Riccardo Molle

2004-01-01

Full Text Available We describe a finite-dimensional reduction method to find solutions for a class of slightly supercritical elliptic problems. A suitable truncation argument allows us to work in the usual Sobolev space even in the presence of supercritical nonlinearities: we modify the supercritical term in such a way to have subcritical approximating problems; for these problems, the finite-dimensional reduction can be obtained applying the methods already developed in the subcritical case; finally, we show that, if the truncation is realized at a sufficiently large level, then the solutions of the approximating problems, given by these methods, also solve the supercritical problems when the parameter is small enough.

Comparison between FLAIR images and T2-weighted fast spin-echo images of cerebral territory and lacunar infarction

International Nuclear Information System (INIS)

Paeng, Mi Hye; Choi, Hye-Young; Lim, Soo Mee; Lee, Jung Sik

2003-01-01

To assess the significance of fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging in the diagnosis of intracranial infarctions and to find out differential points between central lacunar infarctions and perivascular spaces. We consecutively selected 25 cases of territorial infarction in 20 patients, 37 cases of central infarction in 40 patients, and 30 patients with perivascular space. Signal intensity and lesion conspicuity were analyzed and compared between FLAIR and FSE T2-weighted images, and differences in signal intensity between central infarction and perivascular spaces were determined. Lesion conspicuity for FLAIR was better than for T2-weighted images in 12 and 15, worse in 4 and 24, and similar in 9 and 16 of territorial and central infarctions, respectively. In nine cases of territorial and one case of central infarction, there was associated hemorrhage. At FLAIR imaging, perivascular spaces showed a fine round low signal without a peripheral high signal rim in 17 patients but no demonstrable signals in 15. Differential diagnosis of perivascular spaces and central infarction was thus not difficult. FLAIR MRI was useful in the diagnosis of infarctions and in differentiating between central small lacular infarctions and perivascular spaces

Computer program to fit a hyperellipse to a set of phase-space points in as many as six dimensions

International Nuclear Information System (INIS)

Wadlinger, E.A.

1980-03-01

A computer program that will fit a hyperellipse to a set of phase-space points in as many as 6 dimensions was written and tested. The weight assigned to the phase-space points can be varied as a function of their distance from the centroid of the distribution. Varying the weight enables determination of whether there is a difference in ellipse orientation between inner and outer particles. This program should be useful in studying the effects of longitudinal and transverse phase-space couplings

Space shuttle wheels and brakes

Science.gov (United States)

Carsley, R. B.

1985-01-01

The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

Newton-Gauss Algorithm of Robust Weighted Total Least Squares Model

Directory of Open Access Journals (Sweden)

WANG Bin

2015-06-01

Full Text Available Based on the Newton-Gauss iterative algorithm of weighted total least squares (WTLS, a robust WTLS (RWTLS model is presented. The model utilizes the standardized residuals to construct the weight factor function and the square root of the variance component estimator with robustness is obtained by introducing the median method. Therefore, the robustness in both the observation and structure spaces can be simultaneously achieved. To obtain standardized residuals, the linearly approximate cofactor propagation law is employed to derive the expression of the cofactor matrix of WTLS residuals. The iterative calculation steps for RWTLS are also described. The experiment indicates that the model proposed in this paper exhibits satisfactory robustness for gross errors handling problem of WTLS, the obtained parameters have no significant difference with the results of WTLS without gross errors. Therefore, it is superior to the robust weighted total least squares model directly constructed with residuals.

Temporal trends in pregnancy weight gain and birth weight in Bavaria 2000–2007: slightly decreasing birth weight with increasing weight gain in pregnancy

OpenAIRE

Schiessl, Barbara; Beyerlein, Andreas; Lack, Nicholas; Kries, Rüdiger von

2009-01-01

Aims: To assess temporal trends in birth weight and pregnancy weight gain in Bavaria from 2000 to 2007. Methods: Data on 695,707 mother and infant pairs (singleton term births) were available from a compulsory reporting system for quality assurance, including information on birth weight, maternal weight at delivery and at booking, maternal smoking, age, and further anthropometric and lifestyle factors. Pregnancy weight gain was defined as: weight prior to delivery minus weight at first booki...

Upright Cone CT of the hindfoot: Comparison of the non-weight-bearing with the upright weight-bearing position

Energy Technology Data Exchange (ETDEWEB)

Hirschmann, Anna; Pfirrmann, Christian W.A.; Buck, Florian M. [University of Zurich, Department of Radiology, Orthopaedic University Hospital Balgrist, Zurich (Switzerland); Klammer, Georg; Espinosa, Norman [University of Zurich, Department of Orthopedic Surgery, Orthopaedic University Hospital Balgrist, Zurich (Switzerland)

2014-03-15

To prospectively compare computed tomography (CT) of the hindfoot in the supine non-weight-bearing position (NWBCT) with upright weight-bearing position (WBCT). Institutional review board approval and informed consent of all patients were obtained. NWBCT and WBCT scans of the ankle were obtained in 22 patients (mean age, 46.0 ± 17.1 years; range 19-75 years) using a conventional 64-row CT for NWBCT and a novel cone-beam CT for WBCT. Two musculoskeletal radiologists independently performed the following measurements: the hindfoot alignment angle, fibulocalcaneal and tibiocalcaneal distances, lateral talocalcaneal joint space width, talocalcaneal overlap and naviculocalcaneal distance. Significant changes between NWBCT and WBCT were sought using Wilcoxon signed-rank test. P values <0.05 were considered statistically significant. Significant differences were found for all measurements except the hindfoot alignment angle and tibiocalcaneal distance. Significant measurement results were as follows (NWBCT/WBCT reader 1; NWBCT/WBCT reader 2, mean ± standard deviation): fibulocalcaneal distance 3.6 mm ± 5.2/0.3 mm ± 6.0 (P = 0.006); 1.4 mm ± 6.3/-1.1 mm ± 6.3 (P = 0.002), lateral talocalcaneal joint space width 2.9 mm ± 1.7/2.2 mm ± 1.1 (P = 0.005); 3.4 mm ± 1.9/2.4 mm ± 1.3 (P = 0.001), talocalcaneal overlap 4.1 mm ± 3.9/1.4 mm ± 3.9 (P = 0.001); 4.5 mm ± 4.3/1.4 mm ± 3.7 (P < 0.001) and naviculocalcaneal distance 13.5 mm ± 4.0/15.3 mm ± 4.7 (P = 0.037); 14.0 mm ± 4.4/15.7 mm ± 6.2 (P = 0.100). Interreader agreement was good to excellent (ICC 0.48-0.94). Alignment of the hindfoot significantly changes in the upright weight-bearing CT position. Differences can be visualised and measured using WBCT. (orig.)

Inequality, green spaces, and pregnant women: roles of ethnicity and individual and neighbourhood socioeconomic status.

Science.gov (United States)

Dadvand, Payam; Wright, John; Martinez, David; Basagaña, Xavier; McEachan, Rosemary R C; Cirach, Marta; Gidlow, Christopher J; de Hoogh, Kees; Gražulevičienė, Regina; Nieuwenhuijsen, Mark J

2014-10-01

Evidence of the impact of green spaces on pregnancy outcomes is limited with no report on how this impact might vary by ethnicity. We investigated the association between residential surrounding greenness and proximity to green spaces and birth weight and explored the modification of this association by ethnicity and indicators of individual (maternal education) and neighbourhood (Index of Multiple Deprivation) socioeconomic status. Our study was based on 10,780 singleton live-births from the Born in Bradford cohort, UK (2007-2010). We defined residential surrounding greenness as average of satellite-based Normalized Difference Vegetation Index (NDVI) in buffers of 50 m, 100 m, 250 m, 500 m and 1000 m around each maternal home address. Residential proximity to green spaces was defined as living within 300 m of a green space with an area of ≥ 5000 m(2). We utilized mixed effects models to estimate adjusted change in birth weight associated with residential surrounding greenness as well as proximity to green spaces. We found a positive association between birth weight and residential surrounding greenness. Furthermore, we observed an interaction between ethnicity and residential surrounding greenness in that for White British participants there was a positive association between birth weight and residential surrounding greenness whereas for participants of Pakistani origin there was no such an association. For surrounding greenness in larger buffers (500 m and 1000 m) there were some indications of stronger associations for participants with lower education and those living in more deprived neighbourhoods which were not replicated for surrounding greenness in smaller buffer sizes (i.e. 50 m, 100 m, and 250 m). The findings for residential proximity to a green space were not conclusive. Our study showed that residential surrounding greenness is associated with better foetal growth and this association could vary between different ethnic and socioeconomic groups

Nanotechnology Concepts at Marshall Space Flight Center: Engineering Directorate

Science.gov (United States)

Bhat, B.; Kaul, R.; Shah, S.; Smithers, G.; Watson, M. D.

2001-01-01

Nanotechnology is the art and science of building materials and devices at the ultimate level of finesse: atom by atom. Our nation's space program has need for miniaturization of components, minimization of weight, and maximization of performance, and nanotechnology will help us get there. Marshall Space Flight Center's (MSFC's) Engineering Directorate is committed to developing nanotechnology that will enable MSFC missions in space transportation, space science, and space optics manufacturing. MSFC has a dedicated group of technologists who are currently developing high-payoff nanotechnology concepts. This poster presentation will outline some of the concepts being developed including, nanophase structural materials, carbon nanotube reinforced metal and polymer matrix composites, nanotube temperature sensors, and aerogels. The poster will outline these concepts and discuss associated technical challenges in turning these concepts into real components and systems.

Weight control behaviors of highly successful weight loss maintainers: the Portuguese Weight Control Registry.

Science.gov (United States)

Santos, Inês; Vieira, Paulo N; Silva, Marlene N; Sardinha, Luís B; Teixeira, Pedro J

2017-04-01

To describe key behaviors reported by participants in the Portuguese Weight Control Registry and to determine associations between these behaviors and weight loss maintenance. A total of 388 adults participated in this cross-sectional study. Assessments included demographic information, weight history, weight loss and weight maintenance strategies, dietary intake, and physical activity. Participants lost on average 18 kg, which they had maintained for ~28 months. Their average dietary intake was 2199 kcal/day, with 33 % of energy coming from fat. About 78 % of participants engaged in levels of moderate-plus-vigorous physical activity exceeding 150 min/week (51 % above 250 min/week), with men accumulating 82 more minutes than women (p breakfast. Greater weight loss maintenance was associated with higher levels of physical activity, walking, weight self-monitoring, establishing specific goals, and with reduced portion size use, reduced consumption of carbohydrates, and increased consumption of protein, (p < 0.05). Results indicate that weight loss maintenance is possible through the adoption of a nutritionally-balanced diet and regular participation in physical activity, but also suggest that adopting different (and, to a degree, individualized) set of behavioral strategies is key for achieving success.

Radial fractional Laplace operators and Hessian inequalities

Science.gov (United States)

Ferrari, Fausto; Verbitsky, Igor E.

In this paper we deduce a formula for the fractional Laplace operator ( on radially symmetric functions useful for some applications. We give a criterion of subharmonicity associated with (, and apply it to a problem related to the Hessian inequality of Sobolev type: ∫Rn |(u| dx⩽C∫Rn -uFk[u] dx, where Fk is the k-Hessian operator on Rn, 1⩽kFerrari et al. [5] contains the extremal functions for the Hessian Sobolev inequality of X.-J. Wang (1994) [15]. This is proved using logarithmic convexity of the Gaussian ratio of hypergeometric functions which might be of independent interest.

Well-posedness and ill-posedness of the fifth-order modified KdV equation

Directory of Open Access Journals (Sweden)

Soonsik Kwon

2008-01-01

Full Text Available We consider the initial value problem of the fifth-order modified KdV equation on the Sobolev spaces. $$displaylines{ partial_t u - partial_x^5u + c_1partial_x^3(u^3 + c_2upartial_x upartial_x^2 u + c_3uupartial_x^3 u =0cr u(x,0= u_0(x }$$ where $u:mathbb{R}imesmathbb{R} o mathbb{R} $ and $c_j$'s are real. We show the local well-posedness in $H^s(mathbb{R}$ for $sgeq 3/4$ via the contraction principle on $X^{s,b}$ space. Also, we show that the solution map from data to the solutions fails to be uniformly continuous below $H^{3/4}(mathbb{R}$. The counter example is obtained by approximating the fifth order mKdV equation by the cubic NLS equation.

Normed Orlicz function spaces which can be quasi-renormed with easily calculable quasinorms

Czech Academy of Sciences Publication Activity Database

Foralewski, P.; Hudzik, H.; Kaczmarek, R.; Krbec, Miroslav

2017-01-01

Roč. 11, č. 3 (2017), s. 636-660 ISSN 1735-8787 Institutional support: RVO:67985840 Keywords : embeddings into Lebesgue and weighted Lebesgue spaces * Orlicz spaces * quasinorms Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.833, year: 2016 http://projecteuclid.org/euclid.bjma/1496973700

Microwave integrated circuits for space applications

Science.gov (United States)

Leonard, Regis F.; Romanofsky, Robert R.

1991-01-01

Monolithic microwave integrated circuits (MMIC), which incorporate all the elements of a microwave circuit on a single semiconductor substrate, offer the potential for drastic reductions in circuit weight and volume and increased reliability, all of which make many new concepts in electronic circuitry for space applications feasible, including phased array antennas. NASA has undertaken an extensive program aimed at development of MMICs for space applications. The first such circuits targeted for development were an extension of work in hybrid (discrete component) technology in support of the Advanced Communication Technology Satellite (ACTS). It focused on power amplifiers, receivers, and switches at ACTS frequencies. More recent work, however, focused on frequencies appropriate for other NASA programs and emphasizes advanced materials in an effort to enhance efficiency, power handling capability, and frequency of operation or noise figure to meet the requirements of space systems.

Commercial microwave space power

International Nuclear Information System (INIS)

Siambis, J.; Gregorwich, W.; Walmsley, S.; Shockey, K.; Chang, K.

1991-01-01

This paper reports on central commercial space power, generating power via large scale solar arrays, and distributing power to satellites via docking, tethering or beamed power such as microwave or laser beams, that is being investigated as a potentially advantageous alternative to present day technology where each satellite carries its own power generating capability. The cost, size and weight for electrical power service, together with overall mission requirements and flexibility are the principal selection criteria, with the case of standard solar array panels based on the satellite, as the reference point. This paper presents and investigates a current technology design point for beamed microwave commercial space power. The design point requires that 25 kW be delivered to the user load with 30% overall system efficiency. The key elements of the design point are: An efficient rectenna at the user end; a high gain, low beam width, efficient antenna at the central space power station end, a reliable and efficient cw microwave tube. Design trades to optimize the proposed near term design point and to explore characteristics of future systems were performed. Future development for making the beamed microwave space power approach more competitive against docking and tethering are discussed

Empirical investigation of topological and weighted properties of a bus transport network from China

Science.gov (United States)

Shu-Min, Feng; Bao-Yu, Hu; Cen, Nie; Xiang-Hao, Shen; Yu-Sheng, Ci

2016-03-01

Many bus transport networks (BTNs) have evolved into directed networks. A new representation model for BTNs is proposed, called directed-space P. The bus transport network of Harbin (BTN-H) is described as a directed and weighted complex network by the proposed representation model and by giving each node weights. The topological and weighted properties are revealed in detail. In-degree and out-degree distributions, in-weight and out-weight distributions are presented as an exponential law, respectively. There is a strong relation between in-weight and in-degree (also between out-weight and out-degree), which can be fitted by a power function. Degree-degree and weight-weight correlations are investigated to reveal that BTN-H has a disassortative behavior as the nodes have relatively high degree (or weight). The disparity distributions of out-degree and in-degree follow an approximate power-law. Besides, the node degree shows a near linear increase with the number of routes that connect to the corresponding station. These properties revealed in this paper can help public transport planners to analyze the status quo of the BTN in nature. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA110304).

Modal survey testing of the Lidar In-space Technology Experiment (LITE) - A Space Shuttle payload

Science.gov (United States)

Anderson, J. B.; Coleman, A. D.; Driskill, T. C.; Lindell, M. C.

This paper presents the results of the modal survey test of the Lidar In-space Technology Experiment (LITE), a Space Shuttle payload mounted in a Spacelab flight single pallet. The test was performed by the Dynamics Test Branch at Marshall Space Flight Center, AL and run in two phases. In the first phase, an unloaded orthogrid connected to the pallet with 52 tension struts was tested. This test included 73 measurement points in three directions. In the second phase, the pallet was integrated with mass simulators mounted on the flight support structure to represent the dynamics (weight and center of gravity) of the various components comprising the LITE experiment and instrumented at 213 points in 3 directions. The test article was suspended by an air bag system to simulate a free-free boundary condition. This paper presents the results obtained from the testing and analytical model correlation efforts. The effect of the suspension system on the test article is also discussed.

A simple algorithm for computing positively weighted straight skeletons of monotone polygons☆

Science.gov (United States)

Biedl, Therese; Held, Martin; Huber, Stefan; Kaaser, Dominik; Palfrader, Peter

2015-01-01

We study the characteristics of straight skeletons of monotone polygonal chains and use them to devise an algorithm for computing positively weighted straight skeletons of monotone polygons. Our algorithm runs in O(nlog⁡n) time and O(n) space, where n denotes the number of vertices of the polygon. PMID:25648376

A simple algorithm for computing positively weighted straight skeletons of monotone polygons.

Science.gov (United States)

Biedl, Therese; Held, Martin; Huber, Stefan; Kaaser, Dominik; Palfrader, Peter

2015-02-01

We study the characteristics of straight skeletons of monotone polygonal chains and use them to devise an algorithm for computing positively weighted straight skeletons of monotone polygons. Our algorithm runs in [Formula: see text] time and [Formula: see text] space, where n denotes the number of vertices of the polygon.

Pancreas of C57 black mice after long-term space flight (Bion-M1 Space Mission).

Science.gov (United States)

Proshchina, A E; Krivova, Y S; Saveliev, S C

2015-11-01

In this study, we analysed the pancreases of C57BL/6N mice in order to estimate the effects of long-term space flights. Mice were flown aboard the Bion-M1 biosatellite, or remained on ground in the control experiment that replicated environmental and housing conditions in the spacecraft. Vivarium control group was used to account for housing effects. Each of the groups included mice designated for recovery studies. Mice pancreases were dissected for histological and immunohistochemical examinations. Using a morphometry and statistical analysis, a strong correlation between the mean islet size and the mean body weight was revealed in all groups. Therefore, we propose that hypokinesia and an increase in nutrition play an important role in alterations of the endocrine pancreas, both in space flight and terrestrial conditions. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Universal Sample Preparation Module for Molecular Analysis in Space, Phase I

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National Aeronautics and Space Administration — Lynntech proposes to develop and demonstrate the ability of a compact, light-weight, and automated universal sample preparation module (USPM) to process samples from...

Subacute mandibular and hypoglossal nerve denervation causing oedema of the masticator space and tongue

International Nuclear Information System (INIS)

Ho, T.; Lee, K.; Lee, H.

2003-01-01

We report the MRI of five patients with denervation oedema in the head and neck. Four had denervation oedema in one masticator space caused by a skull-base tumour invading the ipsilateral foramen ovale. Another case had denervation oedema confined to the half of the tongue ipsilateral to oral reconstruction surgery which involved mandibulectomy, free flap repair and wide excision of a buccal mucosal carcinoma. Inversion-recovery and/or T2-weighted spin-echo images showed increased signal in the affected areas. Contrast-enhanced T1-weighted images revealed enhancement of the muscles. There was no evidence of tumour or infection in the masticator space or tongue. It is important to differentiate denervation oedema from other disease processes causing high signal on T2-weighted images, such as tumour infiltration and soft-tissue infection. (orig.)

Weight Rhythms: Weight Increases during Weekends and Decreases during Weekdays

Directory of Open Access Journals (Sweden)

Anna-Leena Orsama

2014-01-01

Full Text Available Background/Aims: The week's cycle influences sleep, exercise, and eating habits. An accurate description of weekly weight rhythms has not been reported yet - especially across people who lose weight versus those who maintain or gain weight. Methods: The daily weight in 80 adults (BMI 20.0-33.5 kg/m2; age, 25-62 years was recorded and analysed to determine if a group-level weekly weight fluctuation exists. This was a retrospective study of 4,657 measurements during 15-330 monitoring days. Semi-parametric regression was used to model the rhythm. Results: A pattern of daily weight changes was found (p Conclusion: Weight variations between weekends and weekdays should be considered as normal instead of signs of weight gain. Those who compensate the most are most likely to either lose or maintain weight over time. Long-term habits may make more of a difference than short-term splurges. People prone to weight gain could be counselled about the importance of weekday compensation.

Artifact free T2*-weighted imaging at high spatial resolution using segmented EPI sequences

International Nuclear Information System (INIS)

Heiler, Patrick Michael; Schad, Lothar Rudi; Schmitter, Sebastian

2010-01-01

The aim of this work was the development of novel measurement techniques that acquire high resolution T2 * -weighted datasets in measurement times as short as possible without suffering from noticeable blurring and ghosting artifacts. Therefore, two new measurement techniques were developed that acquire a smoother k-space than generic multi shot echo planar imaging sequences. One is based on the principle of echo train shifting, the other on the reversed gradient method. Simulations and phantom measurements demonstrate that echo train shifting works properly and reduces artifacts in multi shot echo planar imaging. For maximum SNR-efficiency this technique was further improved by adding a second contrast. Both contrasts can be acquired within a prolongation in measurement time by a factor of 1.5, leading to an SNR increase by approximately √2. Furthermore it is demonstrated that the reversed gradient method remarkably reduces artifacts caused by a discontinuous k-space weighting. Assuming sequence parameters as feasible for fMRI experiments, artifact free T2 * -weighted images with a matrix size of 256 x 256 leading to an in-plane resolution in the submillimeter range can be obtained in about 2 s per slice. (orig.)

Global Classical Solutions for Partially Dissipative Hyperbolic System of Balance Laws

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Xu, Jiang; Kawashima, Shuichi

2014-02-01

The basic existence theory of Kato and Majda enables us to obtain local-in-time classical solutions to generally quasilinear hyperbolic systems in the framework of Sobolev spaces (in x) with higher regularity. However, it remains a challenging open problem whether classical solutions still preserve well-posedness in the case of critical regularity. This paper is concerned with partially dissipative hyperbolic system of balance laws. Under the entropy dissipative assumption, we establish the local well-posedness and blow-up criterion of classical solutions in the framework of Besov spaces with critical regularity with the aid of the standard iteration argument and Friedrichs' regularization method. Then we explore the theory of function spaces and develop an elementary fact that indicates the relation between homogeneous and inhomogeneous Chemin-Lerner spaces (mixed space-time Besov spaces). This fact allows us to capture the dissipation rates generated from the partial dissipative source term and further obtain the global well-posedness and stability by assuming at all times the Shizuta-Kawashima algebraic condition. As a direct application, the corresponding well-posedness and stability of classical solutions to the compressible Euler equations with damping are also obtained.

Local well-posedness for a higher order nonlinear Schrodinger equation in Sobolev spaces of negative indices

Directory of Open Access Journals (Sweden)

Xavier Carvajal

2004-01-01

Full Text Available We prove that the initial value problem associated with $$ partial_tu+ialpha partial^2_x u+Beta partial^3_x u +igamma|u|^2u = 0, quad x,t in mathbb{R}, $$ is locally well-posed in $H^s$ for $s>-1/4$.

A Gradient Weighted Moving Finite-Element Method with Polynomial Approximation of Any Degree

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Ali R. Soheili

2009-01-01

Full Text Available A gradient weighted moving finite element method (GWMFE based on piecewise polynomial of any degree is developed to solve time-dependent problems in two space dimensions. Numerical experiments are employed to test the accuracy and effciency of the proposed method with nonlinear Burger equation.

Prejudice and the Plate: Effects of Weight Bias in Nutrition Judgments.

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Schuldt, Jonathon P; Guillory, Jamie E; Gay, Geri K

2016-01-01

As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n>400 total) examining the power of society's widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which--notably--remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered.

Space environment effects on polymers in low earth orbit

International Nuclear Information System (INIS)

Grossman, E.; Gouzman, I.

2003-01-01

Polymers are widely used in space vehicles and systems as structural materials, thermal blankets, thermal control coatings, conformal coatings, adhesives, lubricants, etc. The low earth orbit (LEO) space environment includes hazards such as atomic oxygen, UV radiation, ionizing radiation (electrons, protons), high vacuum, plasma, micrometeoroids and debris, as well as severe temperature cycles. Exposure of polymers and composites to the space environment may result in different detrimental effects via modification of their chemical, electrical, thermal, optical and mechanical properties as well as surface erosion. The high vacuum induces material outgassing (e.g. low-molecular weight residues, plasticizers and additives) and consequent contamination of nearby surfaces. The present work reviews the LEO space environment constituents and their interactions with polymers. Examples of degradation of materials exposed in ground simulation facilities are presented. The issues discussed include the erosion mechanisms of polymers, formation of contaminants and their interaction with the space environment, and protection of materials from the harsh space environment

Haiguste ravi. Kontrollitud / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

2000-01-01

P. Alliku kureeritud näitusest "Naturalism" ja Academia Non Grata performance'itest Kunstihoone galeriis, J. Saare kureeritud näitusest "AIDS kultuuris" Rotermanni soolalaos, J. Zoova ja Kiwa näitusest "Kevaddisko" Tallinna Linnagaleriis, noortebiennaalist "ArtGenda" Helsingis ning H. Soansi ja M. Raadi kureeritud "ArtGenda" projektist "Analoog TV".

Sovhoos sinus eneses / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

2001-01-01

9.-11. VIII Moostes toimunud Evelyn Müürsepa ja Maia Mölleri korraldatud kultuurisündmusest "Postsovkhoz City & Postsovkhoz Person", mis püüdis praeguses eesti külas toimuvat lahti mõtestada. Esinejatest, ettekannetest, kunstinäitustest

"OUT" elab edasi / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

"OUT'98". Kuraatorid Eve Kiiler, Piret Räni. Otsingutest videovallas (I. Helander, A. Nali, K. Sukmit, M. Laanemets, J. Zoova). Näidati ka Tokio vodeofestivalil hõbepreemia saanud R. Kelomehe videot "House". [þmobil]-galerii saatusest.

Kontseptsioonid ja persoonid / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

2003-01-01

Heli Sarapuu näitus "Isale" Hobusepea galeriis. Valeri Vinogradovi "Design Jet 5001" Viviann Napi Galeriis. Eve Kiileri "Progressi arhitektoonika" Tallinna Linnagaleriis. Jan Van Imschooti maalinäitus "Müstilised patud ja kaasaegsed värvid. Ümberhindamise asupaik"

Vaimne dotatsioon meediaikaldusele / Mari Sobolev

Index Scriptorium Estoniae

Sobolev, Mari, 1968-

1998-01-01

Seoses Eesti Kunstimuuseumis toimunud näitusega "Medialization" 22.-23. nov. Eesti Kunstiakadeemias korraldatud meediakonverentsist 'Action ئ Reflection'. Korraldaja Ando Keskküla. Eric Kluitenbergi (Holland), Tapio Mäkela (Soome) ja Hanno Soansi ettekannetest. Avatud kanalist.

Composites Materials and Manufacturing Technologies for Space Applications

Science.gov (United States)

Vickers, J. H.; Tate, L. C.; Gaddis, S. W.; Neal, R. E.

2016-01-01

Composite materials offer significant advantages in space applications. Weight reduction is imperative for deep space systems. However, the pathway to deployment of composites alternatives is problematic. Improvements in the materials and processes are needed, and extensive testing is required to validate the performance, qualify the materials and processes, and certify components. Addressing these challenges could lead to the confident adoption of composites in space applications and provide spin-off technical capabilities for the aerospace and other industries. To address the issues associated with composites applications in space systems, NASA sponsored a Technical Interchange Meeting (TIM) entitled, "Composites Materials and Manufacturing Technologies for Space Applications," the proceedings of which are summarized in this Conference Publication. The NASA Space Technology Mission Directorate and the Game Changing Program chartered the meeting. The meeting was hosted by the National Center for Advanced Manufacturing (NCAM)-a public/private partnership between NASA, the State of Louisiana, Louisiana State University, industry, and academia, in association with the American Composites Manufacturers Association. The Louisiana Center for Manufacturing Sciences served as the coordinator for the TIM.

Three-year weight change in successful weight losers who lost weight on a low-carbohydrate diet.

Science.gov (United States)

Phelan, Suzanne; Wyatt, Holly; Nassery, Shirine; Dibello, Julia; Fava, Joseph L; Hill, James O; Wing, Rena R

2007-10-01

The purpose of this study was to evaluate long-term weight loss and eating and exercise behaviors of successful weight losers who lost weight using a low-carbohydrate diet. This study examined 3-year changes in weight, diet, and physical activity in 891 subjects (96 low-carbohydrate dieters and 795 others) who enrolled in the National Weight Control Registry between 1998 and 2001 and reported >or=30-lb weight loss and >or=1 year weight loss maintenance. Only 10.8% of participants reported losing weight after a low-carbohydrate diet. At entry into the study, low-carbohydrate diet users reported consuming more kcal/d (mean +/- SD, 1,895 +/- 452 vs. 1,398 +/- 574); fewer calories in weekly physical activity (1,595 +/- 2,499 vs. 2,542 +/- 2,301); more calories from fat (64.0 +/- 7.9% vs. 30.9 +/- 13.1%), saturated fat (23.8 +/- 4.1 vs. 10.5 +/- 5.2), monounsaturated fat (24.4 +/- 3.7 vs. 11.0 +/- 5.1), and polyunsaturated fat (8.6 +/- 2.7 vs. 5.5 +/- 2.9); and less dietary restraint (10.8 +/- 2.9 vs. 14.9 +/- 3.9) compared with other Registry members. These differences persisted over time. No differences in 3-year weight regain were observed between low-carbohydrate dieters and other Registry members in intent-to-treat analyses (7.0 +/- 7.1 vs. 5.7 +/- 8.7 kg). It is possible to achieve and maintain long-term weight loss using a low-carbohydrate diet. The long-term health effects of weight loss associated with a high-fat diet and low activity level merits further investigation.

Weight Management

Science.gov (United States)

... Health Information Weight Management English English Español Weight Management Obesity is a chronic condition that affects more ... Liver (NASH) Heart Disease & Stroke Sleep Apnea Weight Management Topics About Food Portions Bariatric Surgery for Severe ...

Executive function in weight loss and weight loss maintenance: a conceptual review and novel neuropsychological model of weight control.

Science.gov (United States)

Gettens, Katelyn M; Gorin, Amy A

2017-10-01

Weight loss maintenance is a complex, multifaceted process that presents a significant challenge for most individuals who lose weight. A growing body of literature indicates a strong relationship between cognitive dysfunction and excessive body weight, and suggests that a subset of high-order cognitive processes known as executive functions (EF) likely play an important role in weight management. Recent reviews cover neuropsychological correlates of weight status yet fail to address the role of executive function in the central dilemma of successful weight loss maintenance. In this paper, we provide an overview of the existing literature examining executive functions as they relate to weight status and initial weight loss. Further, we propose a novel conceptual model of the relationships between EF, initial weight loss, and weight loss maintenance, mapping specific executive functions onto strategies known to be associated with both phases of the weight control process. Implications for the development of more efficacious weight loss maintenance interventions are discussed.

Digital radiography in space.

Science.gov (United States)

Hart, Rob; Campbell, Mark R

2002-06-01

With the permanent habitation of the International Space Station, the planning of longer duration exploration missions, and the possibility of space tourism, it is likely that digital radiography will be needed in the future to support medical care in space. Ultrasound is currently the medical imaging modality of choice for spaceflight. Digital radiography in space is limited because of prohibitive launch costs (in the region of $20,000/kg) that severely restrict the volume, weight, and power requirements of medical care hardware. Technological increases in radiography, a predicted ten-fold decrease in future launch costs, and an increasing clinical need for definitive medical care in space will drive efforts to expand the ability to provide medical care in space including diagnostic imaging. Normal physiological responses to microgravity, in conjunction with the high-risk environment of spaceflight, increase the risk of injury and could imply an extended recovery period for common injuries. The advantages of gravity on Earth, such as the stabilization of patients undergoing radiography and the drainage of fluids, which provide radiographic contrast, are unavailable in space. This creates significant difficulties in patient immobilization and radiographic positioning. Gravity-dependent radiological signs, such as lipohemarthrosis in knee and shoulder trauma, air or fluid levels in pneumoperitoneum, pleural effusion, or bowel obstruction, and the apical pleural edge in pneumothorax become unavailable. Impaired healing processes such as delayed callus formation following fracture will have implications on imaging, and recovery time lines are unknown. The confined nature of spacecraft and the economic impossibility of launching lead-based personal protective equipment present significant challenges to crew radiation safety. A modified, free-floating radiographic C-arm device equipped with a digital detector and utilizing teleradiology support is proposed as a

SPE dose prediction using locally weighted regression

International Nuclear Information System (INIS)

Hines, J. W.; Townsend, L. W.; Nichols, T. F.

2005-01-01

When astronauts are outside earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events (SPEs). The total dose received from a major SPE in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be mitigated with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train and provides predictions as accurate as neural network models previously used. (authors)

SPE dose prediction using locally weighted regression

International Nuclear Information System (INIS)

Hines, J. W.; Townsend, L. W.; Nichols, T. F.

2005-01-01

When astronauts are outside Earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events. The total dose received from a major solar particle event in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be reduced with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train, and provides predictions as accurate as the neural network models that were used previously. (authors)

Stargate GTM: Bridging Descriptor and Activity Spaces.

Science.gov (United States)

Gaspar, Héléna A; Baskin, Igor I; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

2015-11-23

Predicting the activity profile of a molecule or discovering structures possessing a specific activity profile are two important goals in chemoinformatics, which could be achieved by bridging activity and molecular descriptor spaces. In this paper, we introduce the "Stargate" version of the Generative Topographic Mapping approach (S-GTM) in which two different multidimensional spaces (e.g., structural descriptor space and activity space) are linked through a common 2D latent space. In the S-GTM algorithm, the manifolds are trained simultaneously in two initial spaces using the probabilities in the 2D latent space calculated as a weighted geometric mean of probability distributions in both spaces. S-GTM has the following interesting features: (1) activities are involved during the training procedure; therefore, the method is supervised, unlike conventional GTM; (2) using molecular descriptors of a given compound as input, the model predicts a whole activity profile, and (3) using an activity profile as input, areas populated by relevant chemical structures can be detected. To assess the performance of S-GTM prediction models, a descriptor space (ISIDA descriptors) of a set of 1325 GPCR ligands was related to a B-dimensional (B = 1 or 8) activity space corresponding to pKi values for eight different targets. S-GTM outperforms conventional GTM for individual activities and performs similarly to the Lasso multitask learning algorithm, although it is still slightly less accurate than the Random Forest method.

Wavelet based free-form deformations for nonrigid registration

Science.gov (United States)

Sun, Wei; Niessen, Wiro J.; Klein, Stefan

2014-03-01

In nonrigid registration, deformations may take place on the coarse and fine scales. For the conventional B-splines based free-form deformation (FFD) registration, these coarse- and fine-scale deformations are all represented by basis functions of a single scale. Meanwhile, wavelets have been proposed as a signal representation suitable for multi-scale problems. Wavelet analysis leads to a unique decomposition of a signal into its coarse- and fine-scale components. Potentially, this could therefore be useful for image registration. In this work, we investigate whether a wavelet-based FFD model has advantages for nonrigid image registration. We use a B-splines based wavelet, as defined by Cai and Wang.1 This wavelet is expressed as a linear combination of B-spline basis functions. Derived from the original B-spline function, this wavelet is smooth, differentiable, and compactly supported. The basis functions of this wavelet are orthogonal across scales in Sobolev space. This wavelet was previously used for registration in computer vision, in 2D optical flow problems,2 but it was not compared with the conventional B-spline FFD in medical image registration problems. An advantage of choosing this B-splines based wavelet model is that the space of allowable deformation is exactly equivalent to that of the traditional B-spline. The wavelet transformation is essentially a (linear) reparameterization of the B-spline transformation model. Experiments on 10 CT lung and 18 T1-weighted MRI brain datasets show that wavelet based registration leads to smoother deformation fields than traditional B-splines based registration, while achieving better accuracy.

Weight self-regulation process in adolescence: the relationship between control weight attitudes, behaviors and body weight status

Directory of Open Access Journals (Sweden)

Jordi ePich

2015-05-01

Full Text Available Adolescents’ self-control weight behaviors were assessed (n= 1961; 12-17 years old; 2007-2008 in the Balearic Islands, Spain. The study analyzed the relationships between body weight status, body image and self-weight concern, and actual attempts to lose weight by restrained eating and/or increased exercising. In terms of regulatory focus theory (RFT, we considered that efforts to lose or to maintain weight (successful or failed would be motivated either by a promotion focus (to show an attractive body, a prevention focus (to avoid social rejection of fatness, or both. Results showed that 41% of overweight boys and 25% of obese boys stated that they had never made any attempt to lose weight, and 13% and 4% in females. Around half of overweight boys and around a quarter of obese boys stated that they were Not at all concerned about weight gain, and girls’ percentages decreased to 13% and 11% respectively. By contrast 57% of normal weight girls monitored their weight and stated that they had tried to slim at least once. Weight self-regulation in females attempted to combine diet and exercise, while boys relied almost exclusively on exercise. Apparent lack of consciousness of body weight status among overweight boys, and more important, subsequent absence of behaviors to reduce their weight clearly challenges efforts to prevent obesity. We argue that several causes may be involved in this outcome, including unconscious emotional (self-defense and cognitive (dissonance mechanisms driven by perceived social stigmatization of obesity. The active participation of social values of male and female body image (strong vs. pretty and the existence of social habituation to overweight are suggested. A better knowledge of psychosocial mechanisms underlying adolescent weight self-control may improve obesity epidemics.

EFFECTS OF PLANTING SPACE AND HARVEST TIME ON THE NUMBER, WEIGHT AND DIAMETER OF MARIGOLD (CALENDULA OFFICINALIS L. FLOWERS

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Nada Parađiković

2013-06-01

Full Text Available The study was conducted during 2010 in marigold (Calendula officinalis L. to determine the effects of three plant densities (plant density A - 65 cm x 35 cm; plant density B - 65 cm x 25 cm; plant density C – 55 cm x 25 cm and harvest time on the number, weight and diameter of marigold flowers. The results showed that the plant density significantly influenced the number of flowers per plant and flower weight. The largest number of flowers per plant was recorded in the plant density B (13.2 and the lowest (9.87 in the plant density C. The lowest flower weight was recorded in the plant density C (1.31 g and was statistically lower than the flower weight in the plant densities A (1.42 g and B (1.38 g. The plant density significantly influenced the number of flowers on side branches, being the highest in the plant density B. The diameter of the marigold flower was not significantly influenced by the plant density. During the experiment, a total of 13 harvests were achieved. The greatest number of flowers per plant was harvested in the eighth, ninth and tenth harvest, while the largest flower weight was measured in the fifth and twelfth harvest. On the average, the number of flowers per plant / harvest was 11.63 and the weight of flowers was 1.38 g. Diameter of marigold flowers ranged from 2.89 cm to 3.59 cm in the thirteenth and the third harvest, respectively. The number of flowers on side branches per plant / harvest was 11.61.

E VA Space Suit Power, Avionics, and Software Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA is interested in a reliable, robust, and low Size Weight and Power (SWAP) input device that will allow for EVA astronauts to navigate display menu systems. The...

Weighting training images by maximizing distribution similarity for supervised segmentation across scanners

DEFF Research Database (Denmark)

van Opbroek, Annegreet; Vernooij, Meike W; Ikram, M.Arfan

2015-01-01

Many automatic segmentation methods are based on supervised machine learning. Such methods have proven to perform well, on the condition that they are trained on a sufficiently large manually labeled training set that is representative of the images to segment. However, due to differences between...... scanners, scanning parameters, and patients such a training set may be difficult to obtain. We present a transfer-learning approach to segmentation by multi-feature voxelwise classification. The presented method can be trained using a heterogeneous set of training images that may be obtained with different...... scanners than the target image. In our approach each training image is given a weight based on the distribution of its voxels in the feature space. These image weights are chosen as to minimize the difference between the weighted probability density function (PDF) of the voxels of the training images...

Three-dimensional space charge calculation method

International Nuclear Information System (INIS)

Lysenko, W.P.; Wadlinger, E.A.

1981-01-01

A method is presented for calculating space-charge forces suitable for use in a particle tracing code. Poisson's equation is solved in three dimensions with boundary conditions specified on an arbitrary surface by using a weighted residual method. Using a discrete particle distribution as our source input, examples are shown of off-axis, bunched beams of noncircular crosssection in radio-frequency quadrupole (RFQ) and drift-tube linac geometries

Nuclear alkali metal Rankine power systems for space applications

International Nuclear Information System (INIS)

Moyers, J.C.; Holcomb, R.S.

1986-08-01

Nucler power systems utilizing alkali metal Rankine power conversion cycles offer the potential for high efficiency, lightweight space power plants. Conceptual design studies are being carried out for both direct and indirect cycle systems for steady state space power applications. A computational model has been developed for calculating the performance, size, and weight of these systems over a wide range of design parameters. The model is described briefly and results from parametric design studies, with descriptions of typical point designs, are presented in this paper

Nuclear alkali metal Rankine power systems for space applications

International Nuclear Information System (INIS)

Moyers, J.C.; Holcomb, R.S.

1986-01-01

Nuclear power systems utilizing alkali metal Rankine power conversion cycles offer the potential for high efficiency, lightweight space power plants. Conceptual design studies are being carried out for both direct and indirect cycle systems for steady state space power applications. A computational model has been developed for calculating the performance, size, and weight of these systems over a wide range of design parameters. The model is described briefly and results from parametric design studies, with descriptions of typical point designs, are presented in this paper

Some Nonunique Fixed Point Theorems of Ćirić Type on Cone Metric Spaces

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Erdal Karapınar

2010-01-01

Full Text Available Some results of (Ćirić, 1974 on a nonunique fixed point theorem on the class of metric spaces are extended to the class of cone metric spaces. Namely, nonunique fixed point theorem is proved in orbitally complete cone metric spaces under the assumption that the cone is strongly minihedral. Regarding the scalar weight of cone metric, we are able to remove the assumption of strongly minihedral.

Gestational weight gain among minority adolescents predicts term birth weight.

Science.gov (United States)

Ekambaram, Maheswari; Irigoyen, Matilde; DeFreitas, Johelin; Rajbhandari, Sharina; Geaney, Jessica Lynn; Braitman, Leonard Edward

2018-03-07

In adolescents, there is limited evidence on the independent and additive effect of prepregnancy body mass index (BMI) and gestational weight gain on infant birth weight. Data also show that this effect may vary by race. We sought to examine the impact of maternal prepregnancy BMI and gestational weight gain on birth weight and risk of large for gestational age (LGA) in term newborns of minority adolescent mothers. This was a retrospective cohort study of 411 singleton live term infants born to mothers ≤ 18 years. Data were abstracted from electronic medical records. Gestational weight gain was related to infant birth weight (ρ = 0.36, P gain, gestational age and Hispanic ethnicity were independent predictors of birth weight, controlling for maternal age, BMI, parity, tobacco/drug use and preeclampsia. The probability of having an LGA infant increased with weight gain [adjusted odds ratio (aOR) 1.14, 95% confidence interval (CI) 1.07-1.21] but not with BMI. Mothers who gained weight in excess of 2009 Institute of Medicine (IOM) recommendations had a greater risk of having an LGA infant compared to those who gained within recommendations (aOR 5.7, 95% CI 1.6-19.5). Minority adolescents with greater gestational weight gain had infants with higher birth weight and greater risk of LGA; BMI was not associated with either outcome. Further studies are needed to examine the applicability of the 2009 BMI-specific IOM gestational weight gain recommendations to adolescents in minority populations.

An embedding norm and the Lindqvist trigonometric functions

Directory of Open Access Journals (Sweden)

Christer Bennewitz

2002-10-01

Full Text Available We shall calculate the operator norm $|T|_p$ of the Hardy operator $Tf = int_0^x f $, where $1le ple infty$. This operator is related to the Sobolev embedding operator from $W^{1,p}(0,1/mathbb{C}$ into $W^p(0,1/mathbb{C}$. For $1Sobolev embedding operator; Volterra operator.

Association between maternal weight gain and birth weight

DEFF Research Database (Denmark)

Rode, Line; Hegaard, Hanne K; Kjaergaard, Hanne

2007-01-01

To investigate the association between maternal weight gain and birth weight less than 3,000 g and greater than or equal to 4,000 g in underweight (body mass index [BMI] less than 19.8 kg/m(2)), normal weight (BMI 19.8-26.0 kg/m(2)), overweight (BMI 26.1-29.0 kg/m(2)), and obese (BMI greater than...

Effects of Row Spacing and Plant Density on Yield and Yield Components of Sweet Corn in Climatic Conditions of Isfahan

Directory of Open Access Journals (Sweden)

N. Khodaeian

2013-06-01

Full Text Available To evaluate the effects of row spacing and plant density on yield and yield components of sweet corn, variety KSC403, an experiment was conducted in Research Farm of Isfahan University of Technology, Isfahan, Iran, in 2007, as randomized complete block design with a split-plot layout and three replications. The main plots were allocated to two row spacing (60 and 75 cm and the sub-plots accommodated four levels of plant density (50000, 70000, 90000 and 110000 plants per ha. There was significant increase in leaf area index, shoot dry weight, 100-grain fresh weight and grain fresh yield, as row width was decreased from 75 to 60 cm but the plant height was decreased. There was no significant effect of row spacing on number of rows per ear, number of grains per row and number of grains per ear. Plant height, leaf area index, shoot dry weight per m2 and number of ears per m2 were increased with an increase in plant density. The number of rows per ear, number of grains per row, number of grains per ear, 100-grain fresh weight and grain fresh yield were significantly higher under plant densities of 90000 and 110000 as compared to 50000 and 70000 plants per ha. There was significant interaction between row spacing and plant density for leaf area index, shoot dry weight, number of grains per ear, 100-grain fresh weight and grain fresh yield. Under all plant densities, the grain fresh yield was higher in 60-cm row width compared to 70-cm row width. However, the difference between these two row spacing was not significant in plant densities of 50000 and 110000 plants per ha. The highest grain fresh yield (33940 kg/ha was achieved under row spacing 60 cm and 70000 plants per ha and the least grain fresh yield (20750 kg/ha was obtained in under 75 cm row width and 110000 plants per ha. Considering the obtained results of this experiment, to have maximum grain fresh yield of sweet corn under Isfahan climate, the row spacing of 60 cm and plant density of

Body weight perception and body weight control behaviors in adolescents

OpenAIRE

Frank, Robson; Claumann, Gaia S.; Felden, Érico P.G.; Silva, Diego A.S.; Pelegrini, Andreia

2018-01-01

Abstract Objective: To investigate the association between the perception of body weight (as above or below the desired) and behaviors for body weight control in adolescents. Methods: This was a cross-sectional study that included 1051 adolescents (aged 15-19 years) who were high school students attending public schools. The authors collected information on the perception of body weight (dependent variable), weight control behaviors (initiative to change the weight, physical exercise, eatin...

Weight and weight gain during early infancy predict childhood obesity

DEFF Research Database (Denmark)

Andersen, Lise Geisler; Holst, Claus; Michaelsen, Kim F.

2012-01-01

Infant weight and weight gain are positively associated with later obesity, but whether there is a particular critical time during infancy remains uncertain.......Infant weight and weight gain are positively associated with later obesity, but whether there is a particular critical time during infancy remains uncertain....

Weighted Clustering

DEFF Research Database (Denmark)

Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

2012-01-01

We investigate a natural generalization of the classical clustering problem, considering clustering tasks in which different instances may have different weights.We conduct the first extensive theoretical analysis on the influence of weighted data on standard clustering algorithms in both...... the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

Artifact free T2{sup *}-weighted imaging at high spatial resolution using segmented EPI sequences

Energy Technology Data Exchange (ETDEWEB)

Heiler, Patrick Michael; Schad, Lothar Rudi [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Schmitter, Sebastian [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiology

2010-07-01

The aim of this work was the development of novel measurement techniques that acquire high resolution T2{sup *}-weighted datasets in measurement times as short as possible without suffering from noticeable blurring and ghosting artifacts. Therefore, two new measurement techniques were developed that acquire a smoother k-space than generic multi shot echo planar imaging sequences. One is based on the principle of echo train shifting, the other on the reversed gradient method. Simulations and phantom measurements demonstrate that echo train shifting works properly and reduces artifacts in multi shot echo planar imaging. For maximum SNR-efficiency this technique was further improved by adding a second contrast. Both contrasts can be acquired within a prolongation in measurement time by a factor of 1.5, leading to an SNR increase by approximately {radical}2. Furthermore it is demonstrated that the reversed gradient method remarkably reduces artifacts caused by a discontinuous k-space weighting. Assuming sequence parameters as feasible for fMRI experiments, artifact free T2{sup *}-weighted images with a matrix size of 256 x 256 leading to an in-plane resolution in the submillimeter range can be obtained in about 2 s per slice. (orig.)

Space construction engineering - A new career field

Science.gov (United States)

Hagler, T.

1979-01-01

Opportunities for engineers in the design and construction of future large space structures are outlined. Possible space structures for the 1980's include a large mirror to reflect sunlight to earth for night lighting, an antenna for a personal communications system, a deep space communications relay system and a large passive radiometer to measure soil moisture. Considerations in the design of such structures include the lack of gravity, allowing structures to be built with much less supporting weight, the cost of transportation to orbit, leading to the use of aluminum or composite materials stored on reels and attached to a beam builder, and the required surface accuracy in the presence of thermal stresses. Construction factors to consider include the use of astronauts and remote manipulators in assembly, both of which have been demonstrated to be feasible.

SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

International Nuclear Information System (INIS)

Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B; Wang, K; Bayram, E

2016-01-01

Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

Energy Technology Data Exchange (ETDEWEB)

Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B [UT MD Anderson Cancer Center, Houston, TX (United States); Wang, K; Bayram, E [GE Healthcare Technologies, Waukesha, Wisconsin (United States)

2016-06-15

Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

Weighted approximation with varying weight

CERN Document Server

Totik, Vilmos

1994-01-01

A new construction is given for approximating a logarithmic potential by a discrete one. This yields a new approach to approximation with weighted polynomials of the form w"n"(" "= uppercase)P"n"(" "= uppercase). The new technique settles several open problems, and it leads to a simple proof for the strong asymptotics on some L p(uppercase) extremal problems on the real line with exponential weights, which, for the case p=2, are equivalent to power- type asymptotics for the leading coefficients of the corresponding orthogonal polynomials. The method is also modified toyield (in a sense) uniformly good approximation on the whole support. This allows one to deduce strong asymptotics in some L p(uppercase) extremal problems with varying weights. Applications are given, relating to fast decreasing polynomials, asymptotic behavior of orthogonal polynomials and multipoint Pade approximation. The approach is potential-theoretic, but the text is self-contained.

Multifunctional Carbon Nanotube/Polyethylene Complex Composites for Space Radiation Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Polyethylene (PE), due to its high hydrogen content relative to its weight, has been identified by NASA as a promising radiation shielding material against galactic...

Your Health Buddies Matter: Preferential Selection and Social Influence on Weight Management in an Online Health Social Network.

Science.gov (United States)

Meng, Jingbo

2016-12-01

A growing number of online social networks are designed with the intention to promote health by providing virtual space wherein individuals can seek and share information and support with similar others. Research has shown that real-world social networks have a significant influence on one's health behavior and outcomes. However, there is a dearth of studies on how individuals form social networks in virtual space and whether such online social networks exert any impact on individuals' health outcomes. Built on the Multi-Theoretical Multilevel (MTML) framework and drawing from literature on social influence, this study examined the mechanisms underlying the formation of an online health social network and empirically tested social influence on individual health outcomes through the network. Situated in a weight management social networking site, the study tracked a health buddy network of 709 users and their weight management activities and outcomes for 4 months. Actor-based modeling was used to test the joint dynamics of preferential selection and social influence among health buddies. The results showed that baseline, inbreeding, and health status homophily significantly predicted preferential selection of health buddies in the weight management social networking site, whereas self-interest in seeking experiential health information did not. The study also found peer influence of online health buddy networks on individual weight outcomes, such that an individual's odds of losing weight increased if, on average, the individual's health buddies were losing weight.

Gestational weight gain.

Science.gov (United States)

Kominiarek, Michelle A; Peaceman, Alan M

2017-12-01

Prenatal care providers are advised to evaluate maternal weight at each regularly scheduled prenatal visit, monitor progress toward meeting weight gain goals, and provide individualized counseling if significant deviations from a woman's goals occur. Today, nearly 50% of women exceed their weight gain goals with overweight and obese women having the highest prevalence of excessive weight gain. Risks of inadequate weight gain include low birthweight and failure to initiate breast-feeding whereas the risks of excessive weight gain include cesarean deliveries and postpartum weight retention for the mother and large-for-gestational-age infants, macrosomia, and childhood overweight or obesity for the offspring. Prenatal care providers have many resources and tools to incorporate weight and other health behavior counseling into routine prenatal practices. Because many women are motivated to improve health behaviors, pregnancy is often considered the optimal time to intervene for issues related to eating habits and physical activity to prevent excessive weight gain. Gestational weight gain is a potentially modifiable risk factor for a number of adverse maternal and neonatal outcomes and meta-analyses of randomized controlled trials report that diet or exercise interventions during pregnancy can help reduce excessive weight gain. However, health behavior interventions for gestational weight gain have not significantly improved other maternal and neonatal outcomes and have limited effectiveness in overweight and obese women. Copyright © 2017 Elsevier Inc. All rights reserved.

The Weight-Inclusive versus Weight-Normative Approach to Health: Evaluating the Evidence for Prioritizing Well-Being over Weight Loss

Directory of Open Access Journals (Sweden)

Tracy L. Tylka

2014-01-01

Full Text Available Using an ethical lens, this review evaluates two methods of working within patient care and public health: the weight-normative approach (emphasis on weight and weight loss when defining health and well-being and the weight-inclusive approach (emphasis on viewing health and well-being as multifaceted while directing efforts toward improving health access and reducing weight stigma. Data reveal that the weight-normative approach is not effective for most people because of high rates of weight regain and cycling from weight loss interventions, which are linked to adverse health and well-being. Its predominant focus on weight may also foster stigma in health care and society, and data show that weight stigma is also linked to adverse health and well-being. In contrast, data support a weight-inclusive approach, which is included in models such as Health at Every Size for improving physical (e.g., blood pressure, behavioral (e.g., binge eating, and psychological (e.g., depression indices, as well as acceptability of public health messages. Therefore, the weight-inclusive approach upholds nonmaleficience and beneficience, whereas the weight-normative approach does not. We offer a theoretical framework that organizes the research included in this review and discuss how it can guide research efforts and help health professionals intervene with their patients and community.

SANS study of polymer chains in confined space

International Nuclear Information System (INIS)

Hasegawa, Hirokazu; Tanaka, Hideaki; Hashimoto, Takeji; Han, C.C.

1993-01-01

The lateral and vertical components of the radius of gyration for a single block copolymer chain in the lamellar microdomain space formed by a mixture of diblock copolymers and homopolymers were investigated by means of small-angle neutron scattering (SANS), and the microdomain structures by small-angle X-ray scattering (SAXS). We used the homopolymers whose molecular weights are much smaller than that of the corresponding chains of the block copolymers so that the homopolymers are uniformly solubilized in the corresponding microdomains. The SANS result suggests that the block copolymer chains in the microdomain space are more compressed in the direction parallel to the interface and more stretched in the direction perpendicular to the interface than the corresponding unperturbed polymer chains with the same molecular weight. With increasing the volume fraction of the homopolymers the thickness of the lamellar microdomains increases. The block copolymer chains were found to undergo an isochoric affine deformation on addition of the homopolymers or with the change of the thickness of the lamellar microdomains. (author)

Nuclear power in space

International Nuclear Information System (INIS)

Anghaie, S.

2007-01-01

The development of space nuclear power and propulsion in the United States started in 1955 with the initiation of the ROVER project. The first step in the ROVER program was the KIWI project that included the development and testing of 8 non-flyable ultrahigh temperature nuclear test reactors during 1955-1964. The KIWI project was precursor to the PHOEBUS carbon-based fuel reactor project that resulted in ground testing of three high power reactors during 1965-1968 with the last reactor operated at 4,100 MW. During the same time period a parallel program was pursued to develop a nuclear thermal rocket based on cermet fuel technology. The third component of the ROVER program was the Nuclear Engine for Rocket Vehicle Applications (NERVA) that was initiated in 1961 with the primary goal of designing the first generation of nuclear rocket engine based on the KIWI project experience. The fourth component of the ROVER program was the Reactor In-Flight Test (RIFT) project that was intended to design, fabricate, and flight test a NERVA powered upper stage engine for the Saturn-class lunch vehicle. During the ROVER program era, the Unites States ventured in a comprehensive space nuclear program that included design and testing of several compact reactors and space suitable power conversion systems, and the development of a few light weight heat rejection systems. Contrary to its sister ROVER program, the space nuclear power program resulted in the first ever deployment and in-space operation of the nuclear powered SNAP-10A in 1965. The USSR space nuclear program started in early 70's and resulted in deployment of two 6 kWe TOPAZ reactors into space and ground testing of the prototype of a relatively small nuclear rocket engine in 1984. The US ambition for the development and deployment of space nuclear powered systems was resurrected in mid 1980's and intermittently continued to date with the initiation of several research programs that included the SP-100, Space Exploration

Infinitely many solutions for Schrodinger-Kirchhoff type equations involving the fractional p-Laplacian and critical exponent

Directory of Open Access Journals (Sweden)

Li Wang

2016-12-01

Full Text Available In this article, we show the existence of infinitely many solutions for the fractional p-Laplacian equations of Schrodinger-Kirchhoff type equation $$ M([u]_{s, p}^p (-\\Delta _p^s u+V(x|u|^{p-2}u= \\alpha |u|^{ p_s^{*}-2 }u+\\beta k(x|u|^{q-2}u \\quad x\\in \\mathbb{R}^N, $$ where $(-\\Delta ^s_p$ is the fractional p-Laplacian operator, $[u]_{s,p}$ is the Gagliardo p-seminorm, $0 sp$, $1space. By means of the concentration-compactness principle in fractional Sobolev space and Kajikiya's new version of the symmetric mountain pass lemma, we obtain the existence of infinitely many solutions which tend to zero for suitable positive parameters $\\alpha$ and $\\beta$.

Optimal control for parabolic-hyperbolic system with time delay

International Nuclear Information System (INIS)

Kowalewski, A.

1985-07-01

In this paper we consider an optimal control problem for a system described by a linear partial differential equation of the parabolic-hyperbolic type with time delay in the state. The right-hand side of this equation and the initial conditions are not continuous functions usually, but they are measurable functions belonging to L 2 or Lsup(infinity) spaces. Therefore, the solution of this equation is given by a certain Sobolev space. The time delay in the state is constant, but it can be also a function of time. The control time T is fixed in our problem. Making use of the Milutin-Dubovicki theorem, necessary and sufficient conditions of optimality with the quadratic performance functional and constrained control are derived for the Dirichlet problem. The flow chart of the algorithm which can be used in the numerical solving of certain optimization problems for distributed systems is also presented. (author)

Gestational Weight Gain and its Relation with Birth Weight of the Newborn.

Science.gov (United States)

Thapa, Meena; Paneru, Rupa

2017-01-01

Gestational weight gain is an important predictor of the health of the newborn. It is affected by body mass index of the women. This study was conducted to find out gestational weight gain according to Institute of Medicine 2009 recommendation and relationship of newborn birth weight to body mass index and gestational weight gain of the women. It was cross sectional, hospital based study. The women, who attended at term pregnancy for delivery and having recorded first trimester body weight, were included in the study. Their body mass index was calculated and they were stratified into 4 groups according to body mass index. The gestational weight gain was calculated by subtracting first trimester body weight from body weight at the time of admission for delivery. All the women were followed till delivery. The newborn birth weight was taken immediately after delivery. A total of 227 women were enrolled in the study. More than half of the women had normal body mass index. There were 84 (37%) overweight and obese women. Mean gestational weight gain was 10.21 kg, and mean weight of the newborn was 3.05 kg. There were equal number of women who had adequate weight gain and less weight gain according to recommendation. Excess weight gain was seen in 34 (15%) women. Women of higher body mass index and women who had gain more weight during pregnancy had larger newborns. Body mass index and gestational weight gain of the women were important predictors of birth weight of the newborn. There is a positive correlation between gestational weight gain of the women and birth weight of the newborn.

Prevalence of metabolic syndrome using weight and weight indices ...

African Journals Online (AJOL)

Background: Notions about the metabolic syndrome (MS) emphasized the importance of obesity. This may prevent the early diagnosis of the condition in normal weight individuals. Aim: To determine variations in prevalence of MS according to different weight and weight indices. Materials and Methods: 342 apparently ...

Weight Loss Surgery

Science.gov (United States)

Weight loss surgery helps people with extreme obesity to lose weight. It may be an option if you cannot lose weight ... obesity. There are different types of weight loss surgery. They often limit the amount of food you ...

Weighted network modules

International Nuclear Information System (INIS)

Farkas, Illes; Abel, Daniel; Palla, Gergely; Vicsek, Tamas

2007-01-01

The inclusion of link weights into the analysis of network properties allows a deeper insight into the (often overlapping) modular structure of real-world webs. We introduce a clustering algorithm clique percolation method with weights (CPMw) for weighted networks based on the concept of percolating k-cliques with high enough intensity. The algorithm allows overlaps between the modules. First, we give detailed analytical and numerical results about the critical point of weighted k-clique percolation on (weighted) Erdos-Renyi graphs. Then, for a scientist collaboration web and a stock correlation graph we compute three-link weight correlations and with the CPMw the weighted modules. After reshuffling link weights in both networks and computing the same quantities for the randomized control graphs as well, we show that groups of three or more strong links prefer to cluster together in both original graphs

Maternal concern about child weight in a study of weight-discordant siblings.

Science.gov (United States)

Kral, Tanja V E; Moore, Reneé H; Compher, Charlene W

2015-01-01

This study examined concern about child weight in mothers of weight-discordant siblings and determined the accuracy of maternal self-report versus measured child height, weight, and corresponding body mass index (BMI; kg/m(2) ) z-score. Discordant sibling design. Forty-seven mothers of 5- to 12-year-old, weight-discordant siblings. Mothers self-reported their concern about child weight for each child separately and for a subset of children, self-reported their heights and weights. Siblings' height, weight, waist circumference, and adiposity were measured. The majority (83%) of mothers expressed concern about their overweight/obese child's weight and 20% of mothers expressed concern about their normal-weight child's weight (p concern about child weight were positively associated with difference scores in sibling BMI z-score (r = 0.42; p = .01) and percent body fat (r = 0.56; p concern for their overweight/obese child's weight was greater for sibling pairs who were more discordant in their weight. © 2014 Wiley Periodicals, Inc.

Association of Timing of Weight Gain in Pregnancy With Infant Birth Weight.

Science.gov (United States)

Retnakaran, Ravi; Wen, Shi Wu; Tan, Hongzhuan; Zhou, Shujin; Ye, Chang; Shen, Minxue; Smith, Graeme N; Walker, Mark C

2018-02-01

Gestational weight gain is a determinant of infant birth weight, but it is unclear whether its timing in pregnancy may hold implications in this regard. Previous studies have yielded conflicting findings on the association of maternal weight gain in early pregnancy with birth weight. However, as these studies have typically recruited women during the first trimester, they are inherently limited by a reliance on self-reported pregravid weight. To evaluate the associations of directly measured maternal pregravid weight and the timing of subsequent weight gain across pregnancy with infant birth weight. In this prospective, preconception, observational cohort study, 1164 newly married women in Liuyang, China, underwent pregravid evaluation at a median of 19.9 weeks before a singleton pregnancy during which they underwent serial weight measurements. The study was conducted from February 1, 2009, to November 4, 2015. Data analysis was performed between September 1, 2016, and May 6, 2017. Maternal weight gain was calculated for the following 10 gestational intervals: from pregravid to less than 14, 14 to 18, 19 to 23, 24 to 28, 29 to 30, 31 to 32, 33 to 34, 35 to 36, 37 to 38, and 39 to 40 weeks. Associations of pregravid weight and weight gain within each of the 10 gestational intervals with the outcome of infant birth weight. The mean (SD) age of the 1164 women included in the study was 25.3 (3.1) years. Pregravid weight was consistently associated with infant birth weight. However, among the 10 gestational intervals, only weight gain from pregravid to 14 weeks and from 14 to 18 weeks was associated with birth weight. Birth weight increased by 13.6 g/kg (95% CI, 3.2-24.1 g/kg) of maternal weight gain from pregravid to 14 weeks and by 26.1 g/kg (95% CI, 3.8-48.4 g/kg) of maternal weight gain from 14 to 18 weeks. Maternal weight only in the first half of gestation is a determinant of infant birth weight. Before pregnancy and early gestation may be a critical window for

Minimum distraction gap: how much ankle joint space is enough in ankle distraction arthroplasty?

Science.gov (United States)

Fragomen, Austin T; McCoy, Thomas H; Meyers, Kathleen N; Rozbruch, S Robert

2014-02-01

The success of ankle distraction arthroplasty relies on the separation of the tibiotalar articular surfaces. The purpose of this study was to find the minimum distraction gap needed to ensure that the tibiotalar joint surfaces would not contact each other with full weight-bearing while under distraction. Circular external fixators were mounted to nine cadaver ankle specimens. Each specimen was then placed into a custom-designed load chamber. Loads of 0, 350, and 700N were applied to the specimen. Radiographic joint space was measured and joint contact pressure was monitored under each load. The external fixator was then sequentially distracted, and the radiographic joint space was measured under the three different loads. The experiment was stopped when there was no joint contact under 700N of load. The radiographic joint space was measured and the initial (undistracted) radiographic joint space was subtracted from it yielding the distraction gap. The minimum distraction gap (mDG) that would provide total unloading was calculated. The average mDG was 2.4 mm (range, 1.6 to 4.0 mm) at 700N of load, 4.4 mm (range, 3.7 to 5.8 mm) at 350N of load, and 4.9 mm (range, 3.7 to 7.0 mm) at 0N of load. These results suggest that if the radiographic joint space of on a standing X-ray of an ankle undergoing distraction arthroplasty shows a minimum of 5.8 mm of DG, then there will be no contact between joint surfaces during full weight-bearing. Therefore, 5 mm of radiographic joint space, as recommended historically, may not be adequate to prevent contact of the articular surfaces during weight-bearing.

Should providers encourage realistic weight expectations and satisfaction with lost weight in commercial weight loss programs? a preliminary study.

Science.gov (United States)

Ames, Gretchen E; Thomas, Colleen S; Patel, Roshni H; McMullen, Jillian S; Lutes, Lesley D

2014-01-01

Attrition is a problem among patients who participate in commercial weight loss programs. One possible explanation is that if patients are unable to reach a weight that they expect to achieve, they may be more likely to drop out of treatment. This study investigated variables associated with attrition among 30 obese patients who completed a liquid meal replacement program (LMR) and enrolled in a 52-week Small Changes Maintenance intervention (SCM). Patients lost a median 18% of body weight during LMR and completed assessments about weight expectations and weight satisfaction pre- and post-SCM. Of the 30 patients who started SCM, 8 (27%) were lost to attrition. Odds of SCM attrition were higher in patients who lost ≤ 18.2% of pre-LMR weight (OR: 12.25, P = 0.035), had lower satisfaction (≤7) pre-SCM (OR: 10.11, P = 0.040), and who expected further weight loss of 9.1 kg or more pre-SCM (OR: 10.11, P = 0.040). SCM completers significantly increased weight loss expectations by a median of 2.3 kg from pre-SCM to post-SCM (WSR P = 0.049) that paralleled weight regained post-SCM (2.7 kg). After completion of a medically-supervised commercial weight loss program, patients with the greatest expectations for further weight loss and the lowest weight satisfaction were more likely to drop out of SCM. Failure to participate in maintenance treatment may lead to regain of greater than half of lost weight over the next year. Among SCM completers, lower expectations for further weight loss and greater weight satisfaction appeared to be associated with continued engagement in maintenance treatment.

Placental weight and birth weight to placental weight ratio in monochorionic and dichorionic growth-restricted and non-growth-restricted twins

Directory of Open Access Journals (Sweden)

Mariângela Alves Souza

Full Text Available OBJECTIVE: The aim of the present study was to compare the placental weight and birth weight/placental weight ratio for intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. METHODS: This was a retrospective analysis of placentas from twin pregnancies. Placental weight and the birth weight/placental weight ratio were compared in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins. The association between cord insertion type and placental lesions in intrauterine growth-restricted and non-intrauterine growth-restricted monochorionic and dichorionic twins was also investigated. RESULTS: A total of 105 monochorionic (intrauterine growth restriction=40; non-intrauterine growth restriction=65 and 219 dichorionic (intrauterine growth restriction=57; non-intrauterine growth restriction=162 placentas were analyzed. A significantly lower placental weight was observed in intrauterine growth-restricted monochorionic (p=0.022 and dichorionic (p<0.001 twins compared to non-intrauterine growth-restricted twins. There was no difference in the birth weight/placental weight ratio between the intrauterine growth restriction and non-intrauterine growth restriction groups for either monochorionic (p=0.36 or dichorionic (p=0.68 twins. Placental weight and the birth weight/placental weight ratio were not associated with cord insertion type or with placental lesions. CONCLUSION: Low placental weight, and consequently reduced functional mass, appears to be involved in fetal growth restriction in monochorionic and dichorionic twins. The mechanism by which low placental weight influences the birth weight/placental weight ratio in intrauterine growth-restricted monochorionic and dichorionic twins needs to be determined in larger prospective studies.

Power conditioning for space nuclear reactor systems

Science.gov (United States)

Berman, Baruch

1987-01-01

This paper addresses the power conditioning subsystem for both Stirling and Brayton conversion of space nuclear reactor systems. Included are the requirements summary, trade results related to subsystem implementation, subsystem description, voltage level versus weight, efficiency and operational integrity, components selection, and shielding considerations. The discussion is supported by pertinent circuit and block diagrams. Summary conclusions and recommendations derived from the above studies are included.

Effects of egg weight on hatchability, chick hatch-weight and ...

African Journals Online (AJOL)

Egg weight was positively and strongly correlated with egg hatchability (r2 = 0.727) and chick hatch-weight (r2 = 0.953). Heavier-sized eggs hatched chicks had higher mortality rates. Growth rate and live weight of the chickens were optimized at different egg weights of 56 (r2 = 0.657) and 60 (r2 = 0.870) g, respectively, ...

Oncogenesis of melanoma B16 cell clones mutagenized by space environment

International Nuclear Information System (INIS)

Guo Yupeng; Yang Hongsheng; Tang Jingtian; Xu Mei; Geng Chuanying; Fang Qing; Xu Bo; Li Hongyan; Xiang Xing; Pan Lin

2005-01-01

Objective: To explore the oncogenesis of the melanoma B16 cell clones mutagenized by space environment, and find the B16 cell clones with remarkably mutated immunogenicity. Methods: B16 cells were carried by the Chinese 20th recoverable satellite to the outer space, and were harvested after 18 days' spaceflight and then monocloned. Four cell clones, which were randomly selected from the total 110 clones obtained , and the control clone were routinely cultured. The cultured cells were injected to 10 groups of C57BL/6J mice, 82.1 mice in each group. Five groups of mice received hypodermic injection and another 5 groups of mice received abdominal injection. The survival time was observed in abdominal injection groups. The mice in hypodermic injection groups were sacrificed after 14 days, the tumor, spleen and thymus were weighted, and the serum IL-2 concentration was determined. Moreover, the melanoma tumor tissues were examined histopathologically. Results: An experiment program suitable to screening space mutagenesis of B16 tumor cell clones in vivo and the observation indices were basically established. One clone was found out which was remarkably different from the control clone in latent period of tumor formation, tumor weight, survival time of the tumor-bearing mice and the expression of IL-2. Conclusions: Cultured melanoma B16 cells could be mutated by outer space environment. The further study will be focused on the influence of space environment on immunogenicity of mutagenized B16 cells. (authors)

Multilevel weighted least squares polynomial approximation

KAUST Repository

Haji-Ali, Abdul-Lateef

2017-06-30

Weighted least squares polynomial approximation uses random samples to determine projections of functions onto spaces of polynomials. It has been shown that, using an optimal distribution of sample locations, the number of samples required to achieve quasi-optimal approximation in a given polynomial subspace scales, up to a logarithmic factor, linearly in the dimension of this space. However, in many applications, the computation of samples includes a numerical discretization error. Thus, obtaining polynomial approximations with a single level method can become prohibitively expensive, as it requires a sufficiently large number of samples, each computed with a sufficiently small discretization error. As a solution to this problem, we propose a multilevel method that utilizes samples computed with different accuracies and is able to match the accuracy of single-level approximations with reduced computational cost. We derive complexity bounds under certain assumptions about polynomial approximability and sample work. Furthermore, we propose an adaptive algorithm for situations where such assumptions cannot be verified a priori. Finally, we provide an efficient algorithm for the sampling from optimal distributions and an analysis of computationally favorable alternative distributions. Numerical experiments underscore the practical applicability of our method.

Maternal pre-pregnancy body mass index, gestational weight gain influence birth weight.

Science.gov (United States)

Zhao, R; Xu, L; Wu, M L; Huang, S H; Cao, X J

2018-02-01

Evidence suggests that pre-pregnancy body mass index and gestational weight gain have impact on pregnancy and birth weight, yet whether maternal gestational weight gain has a differential effect on the rates of adverse birth weight among women with different pre-pregnancy body mass index categories are unknown. We selected 1617 children matched with their mothers as study subjects. The subjects were divided into three categories: weight gain below the American Institute of Medicine guidelines, weight gain within the American Institute of Medicine guidelines and weight gain above the American Institute of Medicine guidelines. The prevalence of pre-pregnancy underweight and overweight/obese women was 16.3% and 12.3%. And nearly 15.2% of the women had gestational weight gain below American Institute of Medicine guideline, 52.1% of the women had gestational weight gain above American Institute of Medicine guideline. Maternal overweight and obese was associated with increased risk for macrosomia and large-for-gestational age. Women had gestational weight gain below American Institute of Medicine guideline were more likely to have low birth weight and small-for-gestational age than women who had gestational weight gain within American Institute of Medicine guideline. Furthermore, the risks for macrosomia and large-for-gestational age were increased in women with above American Institute of Medicine guideline. And for women with a normal weight before pregnancy, gestational weight gain above the American Institute of Medicine guidelines were associated with higher rates of macrosomia and large-for-gestational age, compared with the women of similar pre-pregnancy weight category but with gestational weight gain within the American Institute of Medicine guidelines. Women with abnormal pre-pregnancy body mass index and gestational weight gain are at risk for adverse birth weight outcomes. Moreover, gestational weight gain has a differential effect on the rates of adverse

Reduction theorems for weighted integral inequalities on the cone of monotone functions

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Stepanov, V.D.

2013-01-01

Roč. 68, č. 4 (2013), s. 597-664 ISSN 0036-0279 R&D Projects: GA ČR GA201/08/0383; GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : weighted Lebesgue space * cone of monotone functions * duality principle Subject RIV: BA - General Mathematics Impact factor: 1.357, year: 2013 http://iopscience.iop.org/0036-0279/68/4/597

The molecular characterization of weighted Hardy spaces

Institute of Scientific and Technical Information of China (English)

LI; Xingmin

2001-01-01

Surveys, 1993, 7: 305.［16］Shephand, N., Statistical aspects of ARCH and stochastic volatility, in Time Series Models in Econometrics, Finance and Other Fields (eds. Cox, D. R., Hinkley, D. V., Barndorff-Nielsen, O. E.), London: Chapman & Hall, 1996, 1.［17］Pantula, S. G., Estimation of autoregressive models with ARCH errors, Sankhya, Ser. B, 1988, 50: 119.［18］Campbell, J. Y., Lo, A. W., Mackinlay, A. C., The Econometrics of Financial Markets, Princeton: Princeton University Press, 1997, 488.［19］Fan, J., Gijbels, I., Local Polynomial Modeling and Its Applications, London: Chapman & Hall, 1996.［20］Lu, Z. D., A note on geometric ergodicity of autoregressive conditional heteroscedasticity (ARCH) model, Statistics and Probability Letters, 1996, 30: 305.［21］Robinson, P. M., Nonparametric estimators for time series, Journal of Time Series Analysis, 1983, 4: 185.［22］Stone, C. J., Optimal rates of convergence for nonparametric estimators, Annals of Statistics, 1980, 8: 1348.［23］Stone, C. J., Optimal global rates of convergence for nonparametric kernel regression, Annals of Statistics, 1982, 10: 1040.［24］Truong, Y. M., Stone, C. J., Nonparametric function estimation involving time series, Annals of Statistics, 1992, 20: 77.［25］Masry, E., Multivariate polynomial regression for time series; uniform strong consistency and rates, Journal of Time Series Analysis, 1996, 17: 571.［26］Ruppert, D., Wand, M. P., Multivariate locally weighted least squares regression, Annals of Statistics, 1994, 22: 1346.［27］Bollerslev, T., Generalized autoregressive conditional heteroscedasticity, Journal of Econometrics, 1986, 31: 307.［28］Engle, R. F., Granger, C. W. J., Co-integration and error-correction: representation, estimation and testing, Econometrica, 1987, 55: 251.

Study on Design Optimization of Centrifugal Compressors Considering Efficiency and Weight

International Nuclear Information System (INIS)

Lee, Younghwan; Kang, Shinhyoung; Ha, Kyunggu

2015-01-01

Various centrifugal compressors are currently used extensively in industrial fields, where the design requirements are more complicated. This makes it more difficult to determine the optimal design point of a centrifugal compressor. Traditionally, the efficiency is an important factor for optimization. In this study, the weight of the compressor was also considered. The aim of this study was to present the design tendency considering the stage efficiency and weight. In addition, this study suggested possibility of a selection of compressor design objectives at an early design stage based on the optimization results. Only a vaneless diffuser was considered in this case. The Kriging method was used with sample points from 1D design program data. The optimal points were determined in a substitute design space.

Study on Design Optimization of Centrifugal Compressors Considering Efficiency and Weight

Energy Technology Data Exchange (ETDEWEB)

Lee, Younghwan; Kang, Shinhyoung [Seoul National University, Seoul (Korea, Republic of); Ha, Kyunggu [Hyundai Motor Group, Ulsan (Korea, Republic of)

2015-04-15

Various centrifugal compressors are currently used extensively in industrial fields, where the design requirements are more complicated. This makes it more difficult to determine the optimal design point of a centrifugal compressor. Traditionally, the efficiency is an important factor for optimization. In this study, the weight of the compressor was also considered. The aim of this study was to present the design tendency considering the stage efficiency and weight. In addition, this study suggested possibility of a selection of compressor design objectives at an early design stage based on the optimization results. Only a vaneless diffuser was considered in this case. The Kriging method was used with sample points from 1D design program data. The optimal points were determined in a substitute design space.

Pancreas of C57 black mice after long-term space flight (Bion-M1 Space Mission)

Science.gov (United States)

Proshchina, A. E.; Krivova, Y. S.; Saveliev, S. C.

2015-11-01

In this study, we analysed the pancreases of C57BL/6N mice in order to estimate the effects of long-term space flights. Mice were flown aboard the Bion-M1 biosatellite, or remained on ground in the control experiment that replicated environmental and housing conditions in the spacecraft. Vivarium control group was used to account for housing effects. Each of the groups included mice designated for recovery studies. Mice pancreases were dissected for histological and immunohistochemical examinations. Using a morphometry and statistical analysis, a strong correlation between the mean islet size and the mean body weight was revealed in all groups. Therefore, we propose that hypokinesia and an increase in nutrition play an important role in alterations of the endocrine pancreas, both in space flight and terrestrial conditions.

Determination of finite-difference weights using scaled binomial windows

KAUST Repository

Chu, Chunlei; Stoffa, Paul L.

2012-01-01

The finite-difference method evaluates a derivative through a weighted summation of function values from neighboring grid nodes. Conventional finite-difference weights can be calculated either from Taylor series expansions or by Lagrange interpolation polynomials. The finite-difference method can be interpreted as a truncated convolutional counterpart of the pseudospectral method in the space domain. For this reason, we also can derive finite-difference operators by truncating the convolution series of the pseudospectral method. Various truncation windows can be employed for this purpose and they result in finite-difference operators with different dispersion properties. We found that there exists two families of scaled binomial windows that can be used to derive conventional finite-difference operators analytically. With a minor change, these scaled binomial windows can also be used to derive optimized finite-difference operators with enhanced dispersion properties. © 2012 Society of Exploration Geophysicists.

Determination of finite-difference weights using scaled binomial windows

KAUST Repository

Chu, Chunlei

2012-05-01

The finite-difference method evaluates a derivative through a weighted summation of function values from neighboring grid nodes. Conventional finite-difference weights can be calculated either from Taylor series expansions or by Lagrange interpolation polynomials. The finite-difference method can be interpreted as a truncated convolutional counterpart of the pseudospectral method in the space domain. For this reason, we also can derive finite-difference operators by truncating the convolution series of the pseudospectral method. Various truncation windows can be employed for this purpose and they result in finite-difference operators with different dispersion properties. We found that there exists two families of scaled binomial windows that can be used to derive conventional finite-difference operators analytically. With a minor change, these scaled binomial windows can also be used to derive optimized finite-difference operators with enhanced dispersion properties. © 2012 Society of Exploration Geophysicists.

Determining the amount of physical activity needed for long-term weight control

Science.gov (United States)

Wier, L. T.; Ayers, G. W.; Jackson, A. S.; Rossum, A. C.; Poston, W. S.; Foreyt, J. P.

2001-01-01

OBJECTIVE: To evaluate prospectively the influence of habitual physical activity on body weight of men and women and to develop a model that defines the role of physical activity on longitudinal weight change. DESIGN AND SETTING: Occupational cohort study conducted for a mean of 5.5 y. SUBJECTS: A total of 496 (341 male and 155 female) NASA/Johnson Space Center employees who completed the 3 month education component of the employee health-related fitness program and remained involved for a minimum of 2 y. MEASUREMENTS: Body weights were measured at baseline (T1) and follow-up (T2), and habitual physical activity was obtained from the mean of multiple ratings of the 11-point (0-10) NASA Activity Scale (NAS) recorded quarterly between T1 and T2. Other measures included age, gender, VO(2 max) obtained from maximal treadmill testing, body mass index (BMI), and body fat percentage. RESULTS: Multiple regression demonstrated that mean NAS, T1 weight, aging and gender all influence long-term T2 weight. T1 age was significant for the men only. Independently, each increase in mean NAS significantly (Pmen (b=-0.91 kg; 95% CI:-1.4 to-0.42 kg) and women (b=-2.14 kg; 95% CI:-2.93 to-1.35 kg). Mean NAS had a greater effect on T2 weight as T1 weight increased, and the relationship was dose-dependent. CONCLUSIONS: Habitual physical activity is a significant source of long-term weight change. The use of self-reported activity level is helpful in predicting long-term weight changes and may be used by health care professionals when counseling patients about the value of physical activity for weight control.