Journal articles: 'Non-compact problems'

1

Ellis, John, K. Enqvist, and D. V. Nanopoulos. "Non-compact supergravity solves problems." Physics Letters B 151, no. 5-6 (February 1985): 357–62. http://dx.doi.org/10.1016/0370-2693(85)91654-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Cavalier, L. "Inverse problems with non-compact operators." Journal of Statistical Planning and Inference 136, no. 2 (February 2006): 390–400. http://dx.doi.org/10.1016/j.jspi.2004.06.063.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Hofmann, Bernd, and G. Fleischer. "Stability Rates for Linear Ill-Posed Problems with Compact and Non-Compact Operators." Zeitschrift für Analysis und ihre Anwendungen 18, no. 2 (1999): 267–86. http://dx.doi.org/10.4171/zaa/881.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Gajic, Ljiljana. "On some optimization problems in not necessarily locally convex space." Yugoslav Journal of Operations Research 18, no. 2 (2008): 167–72. http://dx.doi.org/10.2298/yjor0802167g.

Full text

Abstract:

In this note, by using O. Hadzic's generalization of a fixed point theorem of Himmelberg, we prove a non - cooperative equilibrium existence theorem in non - compact settings and a generalization of an existence theorem for non - compact infinite optimization problems, all in not necessarily locally convex spaces.

APA, Harvard, Vancouver, ISO, and other styles

5

Aussel, Didier, and Asrifa Sultana. "Quasi-variational inequality problems with non-compact valued constraint maps." Journal of Mathematical Analysis and Applications 456, no. 2 (December 2017): 1482–94. http://dx.doi.org/10.1016/j.jmaa.2017.06.034.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

O'Regan, Donal. "Boundary value problems on noncompact intervals." Proceedings of the Royal Society of Edinburgh: Section A Mathematics 125, no. 4 (1995): 777–99. http://dx.doi.org/10.1017/s0308210500030341.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Molica Bisci, Giovanni, and Simone Secchi. "Elliptic problems on complete non-compact Riemannian manifolds with asymptotically non-negative Ricci curvature." Nonlinear Analysis 177 (December 2018): 637–72. http://dx.doi.org/10.1016/j.na.2018.04.019.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Singh, Vishal, Hossain Chizari, and Farzad Ismail. "Non-unified Compact Residual-Distribution Methods for Scalar Advection–Diffusion Problems." Journal of Scientific Computing 76, no. 3 (March 5, 2018): 1521–46. http://dx.doi.org/10.1007/s10915-018-0674-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Rahaman, Mijanur, and Rais Ahmad. "Weak and strong mixed vector equilibrium problems on non-compact domain." Journal of the Egyptian Mathematical Society 23, no. 2 (July 2015): 352–55. http://dx.doi.org/10.1016/j.joems.2014.06.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Fieseler, K. H., and K. Tintarev. "Semilinear elliptic problems and concentration compactness on non-compact Riemannian manifolds." Journal of Geometric Analysis 13, no. 1 (March 2003): 67–75. http://dx.doi.org/10.1007/bf02930997.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Wang, Xiangsheng. "Elliptic boundary value problem on non-compact G-manifolds." International Journal of Mathematics 28, no. 04 (April 2017): 1750025. http://dx.doi.org/10.1142/s0129167x17500252.

Full text

Abstract:

In this paper, an equality between the Hochs–Mathai type index and the Atiyah–Patodi–Singer type index is established when the manifold and the group action are both non-compact, which generalizes a result of Ma and Zhang for compact group actions. As a technical preparation, a problem concerning the Fredholm property of the global elliptic boundary value problems of the Atiyah–Patodi–Singer type on a non-compact manifold is studied.

APA, Harvard, Vancouver, ISO, and other styles

12

DUC, DUONG MINH. "VARIATIONAL PROBLEMS OF CERTAIN FUNCTIONALS." International Journal of Mathematics 06, no. 04 (August 1995): 503–35. http://dx.doi.org/10.1142/s0129167x95000195.

Full text

Abstract:

We get the existence and regularity of minimizers of certain functionals, which may be degenerate and have non-polynomial growth. Applying these results we can find exponentially harmonic maps in every homotopy class of maps from a connected Riemannian C4-manifold into [Formula: see text], where [Formula: see text] is a compact Riemannian C4-manifold.

APA, Harvard, Vancouver, ISO, and other styles

13

de Andrade, Bruno, and Claudio Cuevas. "Compact almost automorphic solutions to semilinear Cauchy problems with non-dense domain." Applied Mathematics and Computation 215, no. 8 (December 2009): 2843–49. http://dx.doi.org/10.1016/j.amc.2009.09.025.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Wegert, E., and M. A. Efendiev. "Nonlinear Riemann—Hilbert problems with Lipschitz continuous boundary condition." Proceedings of the Royal Society of Edinburgh: Section A Mathematics 130, no. 4 (August 2000): 793–800. http://dx.doi.org/10.1017/s0308210500000421.

Full text

Abstract:

Using a norm inequality for singular integral operators in pairs of weighted Lebesgue spaces we are able to prove existence and uniqueness results for solutions of nonlinear RiemannHilbert problems with non-compact Lipschitz continuous restriction curves.

APA, Harvard, Vancouver, ISO, and other styles

15

Gérard, Patrick, and Sandrine Grellier. "Inverse spectral problems for compact Hankel operators." Journal of the Institute of Mathematics of Jussieu 13, no. 2 (April 18, 2013): 273–301. http://dx.doi.org/10.1017/s1474748013000121.

Full text

Abstract:

AbstractGiven two arbitrary sequences $({\lambda }_{j} )_{j\geq 1} $ and $({\mu }_{j} )_{j\geq 1} $ of real numbers satisfying $$\begin{eqnarray*}\displaystyle \vert {\lambda }_{1} \vert \gt \vert {\mu }_{1} \vert \gt \vert {\lambda }_{2} \vert \gt \vert {\mu }_{2} \vert \gt \cdots \gt \vert {\lambda }_{j} \vert \gt \vert {\mu }_{j} \vert \rightarrow 0, &&\displaystyle\end{eqnarray*}$$ we prove that there exists a unique sequence $c= ({c}_{n} )_{n\in { \mathbb{Z} }_{+ } } $, real valued, such that the Hankel operators ${\Gamma }_{c} $ and ${\Gamma }_{\tilde {c} } $ of symbols $c= ({c}_{n} )_{n\geq 0} $ and $\tilde {c} = ({c}_{n+ 1} )_{n\geq 0} $, respectively, are selfadjoint compact operators on ${\ell }^{2} ({ \mathbb{Z} }_{+ } )$ and have the sequences $({\lambda }_{j} )_{j\geq 1} $ and $({\mu }_{j} )_{j\geq 1} $, respectively, as non-zero eigenvalues. Moreover, we give an explicit formula for $c$ and we describe the kernel of ${\Gamma }_{c} $ and of ${\Gamma }_{\tilde {c} } $ in terms of the sequences $({\lambda }_{j} )_{j\geq 1} $ and $({\mu }_{j} )_{j\geq 1} $. More generally, given two arbitrary sequences $({\rho }_{j} )_{j\geq 1} $ and $({\sigma }_{j} )_{j\geq 1} $ of positive numbers satisfying $$\begin{eqnarray*}\displaystyle {\rho }_{1} \gt {\sigma }_{1} \gt {\rho }_{2} \gt {\sigma }_{2} \gt \cdots \gt {\rho }_{j} \gt {\sigma }_{j} \rightarrow 0, &&\displaystyle\end{eqnarray*}$$ we describe the set of sequences $c= ({c}_{n} )_{n\in { \mathbb{Z} }_{+ } } $ of complex numbers such that the Hankel operators ${\Gamma }_{c} $ and ${\Gamma }_{\tilde {c} } $ are compact on ${\ell }^{2} ({ \mathbb{Z} }_{+ } )$ and have sequences $({\rho }_{j} )_{j\geq 1} $ and $({\sigma }_{j} )_{j\geq 1} $, respectively, as non-zero singular values.

APA, Harvard, Vancouver, ISO, and other styles

16

Mazepa, E. A., and D. K. Ryaboshlykova. "Boundary-value problems for the inhomogeneous Schr"odinger equation with variations of its potential on non-compact Riemannian manifolds." Issues of Analysis 28, no. 3 (November 2021): 113–28. http://dx.doi.org/10.15393/j3.art.2021.10911.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Infante, Gennaro. "EIGENVALUES OF SOME NON-LOCAL BOUNDARY-VALUE PROBLEMS." Proceedings of the Edinburgh Mathematical Society 46, no. 1 (January 27, 2003): 75–86. http://dx.doi.org/10.1017/s0013091501001079.

Full text

Abstract:

AbstractWorking on a suitable cone of continuous functions, we give new results for integral equations of the form $\lambda u(t)=\int_{G}k(t,s)f(s,u(s))\,\mathrm{d} s:=Tu(t)$, where $G$ is a compact set in $\mathbb{R}^{n}$ and $k$ is a possibly discontinuous function that is allowed to change sign. We apply our results to prove existence of eigenvalues of some non-local boundary-value problems.AMS 2000 Mathematics subject classification: Primary 34B10. Secondary 34B18; 47H10; 47H30

APA, Harvard, Vancouver, ISO, and other styles

18

Fang, Yi. "Minimal annuli in R3 bounded by non-compact complete convex curves in parallel planes." Journal of the Australian Mathematical Society. Series A. Pure Mathematics and Statistics 60, no. 3 (June 1996): 369–88. http://dx.doi.org/10.1017/s1446788700037885.

Full text

Abstract:

AbstractIn this paper we consider the Plateau problem for surfaces of annular type bounded by a pair of convex, non-compact curves in parallel planes. We prove that for certain symmetric boundaries there are solutions to the non-compact Plateau problems (Theorem B). Except for boundaries consisting of a pair of parallel straight lines, these are the first known examples.

APA, Harvard, Vancouver, ISO, and other styles

19

an Huef, Astrid, S. Kaliszewski, and Iain Raeburn. "Extension problems and non-Abelian duality for C*-algebras." Bulletin of the Australian Mathematical Society 75, no. 2 (April 2007): 229–38. http://dx.doi.org/10.1017/s0004972700039162.

Full text

Abstract:

Suppose that H is a closed subgroup of a locally compact group G. We show that a unitary representation U of H is the restriction of a unitary representation of G if and only if a dual representation Û of a crossed product C*(G) ⋊ (G/H) is regular in an appropriate sense. We then discuss the problem of deciding whether a given representation is regular; we believe that this problem will prove to be an interesting test question in non-Abelian duality for crossed products of C*-algebras.

APA, Harvard, Vancouver, ISO, and other styles

20

S GARCIA, ELINO. "An Exploration of Synthetic Division for Non-Linear Polynomial Divisors." International Multidisciplinary Research Journal 4, no. 1 (March 6, 2022): 11–21. http://dx.doi.org/10.54476/iimrj02.

Full text

Abstract:

As a goal of developing alternative algorithm on division of polynomials whose dividend is 𝑎1𝑥 𝑛 + 𝑎2𝑥 𝑛−1 + 𝑎3𝑥 𝑛−2 + ⋯ + 𝑎𝑛𝑥 + 𝑎𝑛+1 and the divisor is 𝑏1𝑥 𝑚 + 𝑏2𝑥 𝑚−1 + 𝑏3𝑥 𝑚−2 … + 𝑏𝑚𝑥 + 𝑏𝑚+1, where 𝑛 > 𝑚, 𝑎1 ≠ 0, 𝑏1 ≠ 0, and 𝑎𝑖 ′𝑠and 𝑏𝑖 ′𝑠including 𝑎𝑛+1 and 𝑏𝑚+1 are constant, the researcher explored the synthetic division in compact form.The researcher believes that the algorithm in this study is a good alternative in dividing polynomials of higher degrees. In the said compact form, division of only some distinct pairs of non-linear polynomials were presented and served as reference problems for the researcher during the initial exploration. The Division Algorithm for Polynomials theorem was applied in exploring the problems with quadratic, cubic and quartic divisors. This resulted to the development of formulas for the coefficients 𝑡1of the quotient 𝑄(𝑥) and coefficients 𝑟1 of the remainder 𝑅(𝑥) which were considered important parts of the algorithm. Aside from the condition for the inapplicability for non-linear divisors, additional conditions were provided to the problems where the usual synthetic division is inappropriate. At the end, the algorithm on division of polynomials of higher degrees by non-linear divisors was developed using basic research. Illustrative examples of dividing polynomials using the developed algorithms with monic (𝑏1 = 1) and non-monic (𝑏1 ≠ 1) divisors were provided. Results were verified through other existing methods: long division and synthetic division in compact form.

APA, Harvard, Vancouver, ISO, and other styles

21

Boffi, Daniele. "Finite element approximation of eigenvalue problems." Acta Numerica 19 (May 2010): 1–120. http://dx.doi.org/10.1017/s0962492910000012.

Full text

Abstract:

We discuss the finite element approximation of eigenvalue problems associated with compact operators. While the main emphasis is on symmetric problems, some comments are present for non-self-adjoint operators as well. The topics covered include standard Galerkin approximations, non-conforming approximations, and approximation of eigenvalue problems in mixed form. Some applications of the theory are presented and, in particular, the approximation of the Maxwell eigenvalue problem is discussed in detail. The final part tries to introduce the reader to the fascinating setting of differential forms and homological techniques with the description of the Hodge–Laplace eigenvalue problem and its mixed equivalent formulations. Several examples and numerical computations complete the paper, ranging from very basic exercises to more significant applications of the developed theory.

APA, Harvard, Vancouver, ISO, and other styles

22

Geffner, Tomas, and Hector Geffner. "Compact Policies for Fully Observable Non-Deterministic Planning as SAT." Proceedings of the International Conference on Automated Planning and Scheduling 28 (June 15, 2018): 88–96. http://dx.doi.org/10.1609/icaps.v28i1.13880.

Full text

Abstract:

Fully observable non-deterministic (FOND) planning is becoming increasingly important as an approach for computing proper policies in probabilistic planning, extended temporal plans in LTL planning, and general plans in generalized planning. In this work, we introduce a SAT encoding for FOND planning that is compact and can produce compact strong cyclic policies. Simple variations of the encodings are also introduced for strong planning and for what we call, dual FOND planning, where some non-deterministic actions are assumed to be fair (e.g., probabilistic) and others unfair (e.g., adversarial). The resulting FOND planners are compared empirically with existing planners over existing and new benchmarks. The notion of ``probabilistic interesting problems'' is also revisited to yield a more comprehensive picture of the strengths and limitations of current FOND planners and the proposed SAT approach.

APA, Harvard, Vancouver, ISO, and other styles

23

Sengupta, T. K., V. Lakshmanan, and V. V. S. N. Vijay. "A new combined stable and dispersion relation preserving compact scheme for non-periodic problems." Journal of Computational Physics 228, no. 8 (May 2009): 3048–71. http://dx.doi.org/10.1016/j.jcp.2009.01.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

S. Garcia, Elino. "An Exploration of Synthetic Division for Non-Linear Polynomial Divisors." International Multidisciplinary Research Journal 4, no. 1 (March 23, 2022): 10–21. http://dx.doi.org/10.54476/1286801.

Full text

Abstract:

As a goal of developing alternative algorithm on division of polynomials whose dividend is 𝑎1𝑥 𝑛 + 𝑎2𝑥 𝑛−1 + 𝑎3𝑥 𝑛−2 + ⋯ + 𝑎𝑛𝑥 + 𝑎𝑛+1 and the divisor is 𝑏1𝑥 𝑚 + 𝑏2𝑥 𝑚−1 + 𝑏3𝑥 𝑚−2 … + 𝑏𝑚𝑥 + 𝑏𝑚+1, where 𝑛 > 𝑚, 𝑎1 ≠ 0, 𝑏1 ≠ 0, and 𝑎𝑖 ′𝑠and 𝑏𝑖 ′𝑠including 𝑎𝑛+1 and 𝑏𝑚+1 are constant, the researcher explored the synthetic division in compact form.The researcher believes that the algorithm in this study is a good alternative in dividing polynomials of higher degrees. In the said compact form, division of only some distinct pairs of non-linear polynomials were presented and served as reference problems for the researcher during the initial exploration. The Division Algorithm for Polynomials theorem was applied in exploring the problems with quadratic, cubic and quartic divisors. This resulted to the development of formulas for the coefficients 𝑡1of the quotient 𝑄(𝑥) and coefficients 𝑟1 of the remainder 𝑅(𝑥) which were considered important parts of the algorithm. Aside from the condition for the inapplicability for non-linear divisors, additional conditions were provided to the problems where the usual synthetic division is inappropriate. At the end, the algorithm on division of polynomials of higher degrees by non-linear divisors was developed using basic research. Illustrative examples of dividing polynomials using the developed algorithms with monic (𝑏1 = 1) and non-monic (𝑏1 ≠ 1) divisors were provided. Results were verified through other existing methods: long division and synthetic division in compact form. Keywords: synthetic division, high school algebra, short division

APA, Harvard, Vancouver, ISO, and other styles

25

Gordin, V. A. "COMPACT FINITE-DIFFERENCE SCHEMES FOR WEAKLY NON-LINEAR PROBLEMS AND BOUNDARY CONDITIONS IMITATING CAUCHY PROBLEM." XXII workshop of the Council of nonlinear dynamics of the Russian Academy of Sciences 47, no. 1 (April 30, 2019): 32–37. http://dx.doi.org/10.29006/1564-2291.jor-2019.47(1).9.

Full text

Abstract:

Compact finite-difference schemes are well known and provide high accuracy order for differential equation with constant coefficients. Algorithms for constructing compact schemes of the 4-th order for boundary value problems with variable (smooth or jump) coefficient are developed. For the diffusion equations with a smooth variable coefficient and the Levin – Leontovich equation, compact finite-difference schemes are also constructed and their 4-th order is experimentally confirmed. The method of constructing compact schemes of the 4-th order can be generalized to partial differential equations and systems with weak nonlinearity, for example, for the Fisher – Kolmogorov – Petrovsky – Piskunov equation, for the nonlinear Schrödinger equation or for the Fitzhugh – Nagumo system. For such nonlinear problems, a combination of simple explicit schemes and relaxation is used. Richardson’s extrapolation increases the order of the circuits to the 6-th. To approximate multidimensional problems with discontinuous coefficients, for example, the two-dimensional stationary diffusion equation in inhomogeneous media, it is necessary to estimate the possible asymptotics of solutions in the vicinity of the boundary line’s breaks. To do this, we use generalized eigen-functions in the angle, which can be used as a set of test functions and build compact difference schemes approximating the problem on triangular grids with high order of accuracy. The asymptotics along the radius of these generalized eigen-functions (in polar coordinates in the vicinity of the vertex of the angle) have irrational indices which can be found from a special dispersion equation and which determine the indices of the corresponding Bessel functions along the radius. For a number of difference schemes approximating the most important evolutionary equations of mathematical physics, it is possible to construct special boundary conditions imitating the Cauchy problem (ICP) on the whole space. These conditions depend not only on the original equation, but also on the type of the difference scheme, and even on the coefficients of the corresponding differential equation. The ICP conditions are determined with accuracy to a gauge. But the choice of this gauge turns out to be essential with numerical implementation. The role of rational approximations of the Pade – Hermite type of the symbol of the corresponding pseudo-differential operator is important. Examples of movie solutions of problems with ICP conditions for various finite-difference schemes approximating the basic mathematical physics equations, see https://cs.hse.ru/mmsg/transbounds. The study was realized within the framework of the Academic Fund Program at the National Research University – Higher School of Economics (HSE) in 2016–2017 (grant No. 16-05-0069) and by the Russian Academic Excellence Project «5–100».

APA, Harvard, Vancouver, ISO, and other styles

26

Ignatyev, Mikhail. "Inverse scattering problem for Sturm-Liouville operator on non-compact A-graph. Uniqueness result." Tamkang Journal of Mathematics 46, no. 4 (December 22, 2015): 401–22. http://dx.doi.org/10.5556/j.tkjm.46.2015.1806.

Full text

Abstract:

We consider a connected metric graph with the following property: each two cycles can have at most one common point. Such graphs are called A-graphs. On noncompact A-graph we consider a scattering problem for Sturm--Liouville differential operator with standard matching conditions in the internal vertices. Transport, spectral and scattering problems for differential operators on graphs appear frequently in mathematics, natural sciences and engineering. In particular, direct and inverse problems for such operators are used to construct and study models in mechanics, nano-electronics, quantum computing and waveguides. The most complete results on (both direct and inverse) spectral problems were achieved in the case of Sturm--Liouville operators on compact graphs, in the noncompact case there are no similar general results. In this paper, we establish some properties of the spectral characteristics and investigate the inverse problem of recovering the operator from the scattering data. A uniqueness theorem for such inverse problem is proved.

APA, Harvard, Vancouver, ISO, and other styles

27

Ghimenti, Marco G., and Anna Maria Micheletti. "Compactness and blow up results for doubly perturbed Yamabe problems on manifolds with non umbilic boundary." Mathematical Biosciences and Engineering 30, no. 4 (2022): 1209–35. http://dx.doi.org/10.3934/era.2022064.

Full text

Abstract:

<abstract><p>We study the stability of compactness of solutions for the Yamabe boundary problem on a compact Riemannian manifold with non umbilic boundary. We prove that the set of solutions of Yamabe boundary problem is a compact set when perturbing the mean curvature of the boundary from below and the scalar curvature with a function whose maximum is not too positive. In addition, we prove the counterpart of the stability result: there exists a blowing up sequence of solutions when we perturb the mean curvature from above or the mean curvature from below and the scalar curvature with a function with a large positive maximum.</p></abstract>

APA, Harvard, Vancouver, ISO, and other styles

28

Hofmann, B., D. Düvelmeyer, and K. Krumbiegel. "APPROXIMATE SOURCE CONDITIONS IN TIKHONOV REGULARIZATION‐NEW ANALYTICAL RESULTS AND SOME NUMERICAL STUDIES." Mathematical Modelling and Analysis 11, no. 1 (March 31, 2006): 41–56. http://dx.doi.org/10.3846/13926292.2006.9637301.

Full text

Abstract:

We present some new ideas and results for finding convergence rates in Tikhonov regularization for ill‐posed linear inverse problems with compact and non‐compact forward operators based on the consideration of approximate source conditions and corresponding distance functions. The new results and studies complement and extend in numerous points the recent papers [5, 7, 8, 10] that also exploit the distance functions originally introduced in [2] which measure the violation of a moderate source condition that works as a benchmark. In this context, we distinguish as in [8] logarithmic, power and exponential decay rates for the distance functions and their consequences. Under specific range inclusions the decay rate of distance functions is verified explicitly, whereas in [10] this result is also used but formulated only in an implicit manner. Applications to non‐compact multiplication operators are briefly reviewed from [8]. An important new result is that we can show for compact operators a one‐to‐one correspondence between the maximal power type decay rates for the distance functions and maximal exponents of Holder rates in Tikhonov regularization linked by the specific singular value expansion of the solution element. Some numerical studies on simple integration illustrate the compact operator case and the specific situation of discretized problems. Finally, some ideas of generalization are mentioned concerning the fact that the benchmark of the distance function can be shifted.

APA, Harvard, Vancouver, ISO, and other styles

29

Mazepa, Elena. "On Solvability of Boundary Value Problems of the Poisson Equation on Non-Compact Riemannian Manifolds." Vestnik Volgogradskogo gosudarstvennogo universiteta. Serija 1. Mathematical Physics and Computer Modeling 20, no. 3 (September 2017): 136–47. http://dx.doi.org/10.15688/mpcm.jvolsu.2017.3.10.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Long, Guangqing, Xiaoyuan Huang, Aimei Tan, and Gnaneshwar Nelakanti. "Discrete product integration methods for eigen-problems of a class of non-compact integral operators." Applied Mathematics and Computation 219, no. 15 (April 2013): 7964–72. http://dx.doi.org/10.1016/j.amc.2013.02.034.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Majidian, H., and E. Babolian. "An interpolation degenerate kernel method for eigenvalue problems of a class of non-compact operators." Applied Mathematics Letters 23, no. 8 (August 2010): 825–30. http://dx.doi.org/10.1016/j.aml.2010.01.019.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Talgorn, Bastien, and Michael Kokkolaras. "Compact implementation of non-hierarchical analytical target cascading for coordinating distributed multidisciplinary design optimization problems." Structural and Multidisciplinary Optimization 56, no. 6 (July 3, 2017): 1597–602. http://dx.doi.org/10.1007/s00158-017-1726-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Meskhi, Alexander. "On a measure of non-compactness for singular integrals." Journal of Function Spaces and Applications 1, no. 1 (2003): 35–43. http://dx.doi.org/10.1155/2003/927590.

Full text

Abstract:

It is proved that there exists no weight pair(v, w)for which a singular integral operator is compact from the weighted Lebesgue spaceLwp(Rn)toLvp(Rn). Moreover, a measure of non-compatness for this operator is estimated from below. Analogous problems for Cauchy singular integrals defined on Jordan smooth curves are studied.

APA, Harvard, Vancouver, ISO, and other styles

34

Infante, Gennaro, and J. R. L. Webb. "NONLINEAR NON-LOCAL BOUNDARY-VALUE PROBLEMS AND PERTURBED HAMMERSTEIN INTEGRAL EQUATIONS." Proceedings of the Edinburgh Mathematical Society 49, no. 3 (October 2006): 637–56. http://dx.doi.org/10.1017/s0013091505000532.

Full text

Abstract:

AbstractMotivated by some non-local boundary-value problems (BVPs) that arise in heat-flow problems, we establish new results for the existence of non-zero solutions of integral equations of the form$$ u(t)=\gamma(t)\alpha[u]+\int_{G}k(t,s)f(s,u(s))\,\mathrm{d}s, $$where $G$ is a compact set in $\mathbb{R}^{n}$. Here $\alpha[u]$ is a positive functional and $f$ is positive, while $k$ and $\gamma$ may change sign, so positive solutions need not exist. We prove the existence of multiple non-zero solutions of the BVPs under suitable conditions. We show that solutions of the BVPs lose positivity as a parameter decreases. For a certain parameter range not all solutions can be positive, but for one of the boundary conditions we consider we show that there are positive solutions for certain types of nonlinearity. We also prove a uniqueness result.

APA, Harvard, Vancouver, ISO, and other styles

35

GOLODETS, VALENTIN YA, and SERGEY D. SINEL'SHCHIKOV. "On the conjugacy and isomorphism problems for stabilizers of Lie group actions." Ergodic Theory and Dynamical Systems 19, no. 2 (April 1999): 391–411. http://dx.doi.org/10.1017/s014338579913013x.

Full text

Abstract:

The spaces of subgroups and Lie subalgebras with the group actions by conjugations are considered for real Lie groups. Our approach allows one to apply the properties of algebraically regular transformation groups to finding the conditions when those actions turn out to be type I. It follows, in particular, that in this case the stability groups for all the ergodic actions of such groups are conjugate (for example when the stability groups are compact). The isomorphism of the stability groups for ergodic actions is also established under some assumptions. A number of examples of non-conjugate and non-isomorphic stability groups are presented.

APA, Harvard, Vancouver, ISO, and other styles

36

Marraffa, Valeria, and Bianca Satco. "Stieltjes Differential Inclusions with Periodic Boundary Conditions without Upper Semicontinuity." Mathematics 10, no. 1 (December 24, 2021): 55. http://dx.doi.org/10.3390/math10010055.

Full text

Abstract:

We are studying first order differential inclusions with periodic boundary conditions where the Stieltjes derivative with respect to a left-continuous non-decreasing function replaces the classical derivative. The involved set-valued mapping is not assumed to have compact and convex values, nor to be upper semicontinuous concerning the second argument everywhere, as in other related works. A condition involving the contingent derivative relative to the non-decreasing function (recently introduced and applied to initial value problems by R.L. Pouso, I.M. Marquez Albes, and J. Rodriguez-Lopez) is imposed on the set where the upper semicontinuity and the assumption to have compact convex values fail. Based on previously obtained results for periodic problems in the single-valued cases, the existence of solutions is proven. It is also pointed out that the solution set is compact in the uniform convergence topology. In particular, the existence results are obtained for periodic impulsive differential inclusions (with multivalued impulsive maps and finite or possibly countable impulsive moments) without upper semicontinuity assumptions on the right-hand side, and also the existence of solutions is derived for dynamic inclusions on time scales with periodic boundary conditions.

APA, Harvard, Vancouver, ISO, and other styles

37

Dello Russo, Anahí, and Ana E. Alonso. "Mixed Finite Element Analysis of Eigenvalue Problems on Curved Domains." Computational Methods in Applied Mathematics 14, no. 1 (January 1, 2014): 1–33. http://dx.doi.org/10.1515/cmam-2013-0014.

Full text

Abstract:

Abstract. In this paper we present a theoretical framework for the analysis of the numerical approximations of a particular class of eigenvalue problems by mixed/hybrid methods. More precisely, we are interested in eigenproblems which are defined over curved domains or have internal curved boundaries and which may be associated with non-compact inverse operators. To do this, we consider external domain approximations $\Omega _{h}$ of the original domain $\Omega $, i.e., $\Omega _{h} \lnot \subset \Omega $. Sufficient conditions to ensure good convergence properties and optimal error bounds for the external approximations of the eigenfunction/eigenvalue pairs are established. Then, these results are applied to the study of the Stokes eigenvalue problem with slip boundary condition defined on a curved non-convex two-dimensional domain.

APA, Harvard, Vancouver, ISO, and other styles

38

Friderikos, Orestis, Marc Olive, Emmanuel Baranger, Dimitris Sagris, and Constantine David. "A non-intrusive space-time interpolation from compact Stiefel manifolds of parametrized rigid-viscoplastic FEM problems." Computational Mechanics 68, no. 4 (June 30, 2021): 861–83. http://dx.doi.org/10.1007/s00466-021-02050-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Dai, Ruxin, Yin Wang, and Xiwei Wang. "Effects of Different High Order Compact Computations for Solving Boundary Layer Problems on Non-Uniform Grids." Journal of Computational Intelligence and Electronic Systems 3, no. 3 (September 1, 2014): 200–211. http://dx.doi.org/10.1166/jcies.2014.1091.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Rodriguez, Armando A., and Munther A. Dahleh. "On the computation of induced norms for non-compact Hankel operators arising from distributed control problems." Systems & Control Letters 19, no. 6 (December 1992): 429–38. http://dx.doi.org/10.1016/0167-6911(92)90074-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Liang, Yan, Xiao Ming Wu, Bi Hua Tang, and Yong Le Wu. "Compact LowPass Filter with Wide StopBand Using Non-Uniform Microstrip Resonant Cells." Applied Mechanics and Materials 263-266 (December 2012): 15–19. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.15.

Full text

Abstract:

In this paper, a novel compact microstrip lowpass filter is designed. The proposed filter which is etched on the 50 Ω microstrip line consists of four non-uniform 1-D microstrip photonic bandgap (PBG) cells with different cutoff frequency.. The demonstration lowpass filter with 2.2 GHz cutoff frequency is designed, fabricated and measured. The measurement results show that the band rejection effect is better than -20 dB from 2.8 GHz to 10 GHz, the insertion is less than 2 dB, and the length of filter is 5.6 cm long. Compared with the conventional filter, the proposed filter has smaller size. Meanwhile, it overcomes the problems of narrow stop-band and low harmonic suppression. Furthermore, the impedance matching is not need to be considered. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

APA, Harvard, Vancouver, ISO, and other styles

42

Ashton, Brenden, and Ian Doust. "A COMPARISON OF ALGEBRAS OF FUNCTIONS OF BOUNDED VARIATION." Proceedings of the Edinburgh Mathematical Society 49, no. 3 (October 2006): 575–91. http://dx.doi.org/10.1017/s0013091504001130.

Full text

Abstract:

AbstractMotivated by problems in the spectral theory of linear operators, we previously introduced a new concept of variation for functions defined on a non-empty compact subset of the plane. In this paper, we examine the algebras of functions of bounded variation one obtains from these new definitions for the case where the underlying compact set is either a rectangle or the unit circle, and compare these algebras with those previously used by Berkson and Gillespie in their theories of AC-operators and trigonometrically well-bounded operators.

APA, Harvard, Vancouver, ISO, and other styles

43

Matevossian, Hovik A. "Mixed Boundary Value Problems for the Elasticity System in Exterior Domains." Mathematical and Computational Applications 24, no. 2 (June 2, 2019): 58. http://dx.doi.org/10.3390/mca24020058.

Full text

Abstract:

We study the properties of solutions of the mixed Dirichlet–Robin and Neumann–Robin problems for the linear system of elasticity theory in the exterior of a compact set and the asymptotic behavior of solutions of these problems at infinity under the assumption that the energy integral with weight | x | a is finite for such solutions. We use the variational principle and depending on the value of the parameter a, obtain uniqueness (non-uniqueness) theorems of the mixed problems or present exact formulas for the dimension of the space of solutions.

APA, Harvard, Vancouver, ISO, and other styles

44

CORRÊA, F. J. S. A., J. V. GONCALVES, and ANGELO RONCALLI. "ON A CLASS OF FOURTH ORDER NONLINEAR ELLIPTIC EQUATIONS UNDER NAVIER BOUNDARY CONDITIONS." Analysis and Applications 08, no. 02 (April 2010): 185–97. http://dx.doi.org/10.1142/s0219530510001576.

Full text

Abstract:

We employ arguments involving continua of fixed points of suitable nonlinear compact operators and the Lyapunov–Schmidt method to prove existence and multiplicity of solutions in a class of fourth order non-homogeneous resonant elliptic problems. Our main result extends even similar ones known for the Laplacian.

APA, Harvard, Vancouver, ISO, and other styles

45

Matevossian, Hovik. "On the Mixed Dirichlet–Steklov-Type and Steklov-Type Biharmonic Problems in Weighted Spaces." Mathematical and Computational Applications 24, no. 1 (February 18, 2019): 25. http://dx.doi.org/10.3390/mca24010025.

Full text

Abstract:

We studied the properties of generalized solutions in unbounded domains and the asymptotic behavior of solutions of elliptic boundary value problems at infinity. Moreover, we studied the unique solvability of the mixed Dirichlet–Steklov-type and Steklov-type biharmonic problems in the exterior of a compact set under the assumption that generalized solutions of these problems has a bounded Dirichlet integral with weight | x | a . Depending on the value of the parameter a, we obtained uniqueness (non-uniqueness) theorems of these problems or present exact formulas for the dimension of the space of solutions.

APA, Harvard, Vancouver, ISO, and other styles

46

FUJII, KAZUYUKI. "STANDARD AND NON-STANDARD QUANTUM MODELS: A NON-COMMUTATIVE VERSION OF THE CLASSICAL SYSTEM OF SU(2) AND SU(1,1) ARISING FROM QUANTUM OPTICS." International Journal of Geometric Methods in Modern Physics 02, no. 05 (October 2005): 783–821. http://dx.doi.org/10.1142/s0219887805000879.

Full text

Abstract:

This is a challenging paper that includes some reviews and new results. Since the non-commutative version of the classical system based on the compact group SU(2) has been constructed in (quant-ph/0502174) by making use of Jaynes–Commings model and so-called quantum diagonalization method in (quant-ph/0502147), we construct a non-commutative version of the classical system based on the non-compact group SU(1,1) by modifying the compact case. In this model the Hamiltonian is not hermite but pseudo hermite, which causes a big difference between the two models. For example, in the classical representation theory of SU(1,1), unitary representations are infinite dimensional from the starting point. Therefore, to develop a unitary theory of non-commutative system of SU(1,1) we need an infinite number of non-commutative systems, which means a kind of second non-commutativization. This is a very hard and interesting problem. We develop a corresponding theory though it is not always enough, and present some challenging problems concerning how classical properties can be extended to the non-commutative case. This paper is arranged for the convenience of readers as the first subsection is based on the standard model (SU(2) system) and the next one is based on the non-standard model (SU(1,1) system). This contrast may make the similarities and differences between the standard and non-standard models clearer.

APA, Harvard, Vancouver, ISO, and other styles

47

Angelova, I. Tr. "HIGH-ORDER DIFFERENCE SCHEMES FOR CONVECTION‐DIFFUSION INTERFACE PROBLEMS." Mathematical Modelling and Analysis 10, no. 4 (December 31, 2005): 319–34. http://dx.doi.org/10.3846/13926292.2005.9637290.

Full text

Abstract:

On non‐uniform mesh new high‐order compact finite difference approximations of the solution and the flux to convection‐diffusion interface problems in one‐dimension are constructed and analyzed. Explicit formulas based on new Marchuk integral identities that give O(h2), O(h4), . . . accuracy are derived. New numerical integration quadrature procedures for computing three‐point schemes of any prescribed order of accuracy are developed. Numerical experiments confirm the theoretical results. Straipsnyje sukonstruotos ir analizuojamos naujos aukštos eiles kompaktines baigtiniu skirtumu schemos, aproksimuojančios konvekcijos‐difuzijos saveikos uždavinius vienmačiu atveju. Gautos išreikštines O(h 2), O(h4), … eiles tikslumo formules, pagristos Marchuko integralinemis tapatybemis. Išvestos naujos skaitmeninio integravimo kvadratūrines nurodyto tikslumo formules tritaškiu schemu skaičiavimui. Pateikti skaitiniai eksperimentai, patvirtinantys teorinius rezultatus.

APA, Harvard, Vancouver, ISO, and other styles

48

Britt, Steven, Semyon Tsynkov, and Eli Turkel. "Numerical Simulation of Time-Harmonic Waves in Inhomogeneous Media using Compact High Order Schemes." Communications in Computational Physics 9, no. 3 (March 2011): 520–41. http://dx.doi.org/10.4208/cicp.091209.080410s.

Full text

Abstract:

AbstractIn many problems, one wishes to solve the Helmholtz equation with variable coefficients within the Laplacian-like term and use a high order accurate method (e.g., fourth order accurate) to alleviate the points-per-wavelength constraint by reducing the dispersion errors. The variation of coefficients in the equation may be due to an inhomogeneous medium and/or non-Cartesian coordinates. This renders existing fourth order finite difference methods inapplicable. We develop a new compact scheme that is provably fourth order accurate even for these problems. We present numerical results that corroborate the fourth order convergence rate for several model problems.

APA, Harvard, Vancouver, ISO, and other styles

49

Aminnuddin, Hazim Fadli, Farzad Ismail, Akmal Nizam Mohamed, and Kamil Abdullah. "The Effect of Grid Skewness on Non-Unified Compact Residual Distribution Methods for Scalar Advection Diffusion Problems." CFD Letters 12, no. 3 (March 25, 2020): 58–65. http://dx.doi.org/10.37934/cfdl.12.3.5865.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Mazеpa, Elеna. "The Approximation Approach to Construction of Solutions of Boundary Value Problems on Non-Compact Rieman-nian Manifolds." Vestnik Volgogradskogo gosudarstvennogo universiteta. Serija 1. Mathematica. Physica, no. 5 (December 2015): 25–35. http://dx.doi.org/10.15688/jvolsu1.2015.5.2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Non-compact problems'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles