Directory of Open Access Journals (Sweden)
George Isac
2004-01-01
Full Text Available In the first part of this paper we present a representation theorem for the directional derivative of the metric projection operator in an arbitrary Hilbert space. As a consequence of the representation theorem, we present in the second part the development of the theory of projected dynamical systems in infinite dimensional Hilbert space. We show that this development is possible if we use the viable solutions of differential inclusions. We use also pseudomonotone operators.
Response to the Comment by G. Emch on projective group representations in quaternionic Hilbert space
International Nuclear Information System (INIS)
Adler, S.L.
1996-01-01
We discuss the differing definitions of complex and quaternionic projective group representations employed by us and by Emch. The definition of Emch (termed here a strong projective representation) is too restrictive to accommodate quaternionic Hilbert space embeddings of complex projective representations. Our definition (termed here a weak projective representation) encompasses such embeddings, and leads to a detailed theory of quaternionic, as well as complex, projective group representations. copyright 1996 American Institute of Physics
Plymen, Roger; Robinson, Paul
1995-01-01
Infinite-dimensional Clifford algebras and their Fock representations originated in the quantum mechanical study of electrons. In this book, the authors give a definitive account of the various Clifford algebras over a real Hilbert space and of their Fock representations. A careful consideration of the latter's transformation properties under Bogoliubov automorphisms leads to the restricted orthogonal group. From there, a study of inner Bogoliubov automorphisms enables the authors to construct infinite-dimensional spin groups. Apart from assuming a basic background in functional analysis and operator algebras, the presentation is self-contained with complete proofs, many of which offer a fresh perspective on the subject.
A constructive presentation of rigged Hilbert spaces
International Nuclear Information System (INIS)
Celeghini, Enrico
2015-01-01
We construct a rigged Hilbert space for the square integrable functions on the line L2(R) adding to the generators of the Weyl-Heisenberg algebra a new discrete operator, related to the degree of the Hermite polynomials. All together, continuous and discrete operators, constitute the generators of the projective algebra io(2). L 2 (R) and the vector space of the line R are shown to be isomorphic representations of such an algebra and, as both these representations are irreducible, all operators defined on the rigged Hilbert spaces L 2 (R) or R are shown to belong to the universal enveloping algebra of io(2). The procedure can be extended to orthogonal and pseudo-orthogonal spaces of arbitrary dimension by tensorialization.Circumventing all formal problems the paper proposes a kind of toy model, well defined from a mathematical point of view, of rigged Hilbert spaces where, in contrast with the Hilbert spaces, operators with different cardinality are allowed. (paper)
International Nuclear Information System (INIS)
Exner, P.; Kolerov, G.I.
1980-01-01
A Hilbert space of paths, the elements of which are determined by trigonometric series, was proposed and used recently by Truman. This space is shown to consist precisely of all absolutely continuous paths ending in the origin with square-integrable derivatives
Hilbert-type inequalities for Hilbert space operators | Krnic ...
African Journals Online (AJOL)
In this paper we establish a general form of the Hilbert inequality for positive invertible operators on a Hilbert space. Special emphasis is given to such inequalities with homogeneous kernels. In some general cases the best possible constant factors are also derived. Finally, we obtain the improvement of previously deduced ...
Teleportation schemes in infinite dimensional Hilbert spaces
International Nuclear Information System (INIS)
Fichtner, Karl-Heinz; Freudenberg, Wolfgang; Ohya, Masanori
2005-01-01
The success of quantum mechanics is due to the discovery that nature is described in infinite dimension Hilbert spaces, so that it is desirable to demonstrate the quantum teleportation process in a certain infinite dimensional Hilbert space. We describe the teleportation process in an infinite dimensional Hilbert space by giving simple examples
Weaving Hilbert space fusion frames
Neyshaburi, Fahimeh Arabyani; Arefijamaal, Ali Akbar
2018-01-01
A new notion in frame theory, so called weaving frames has been recently introduced to deal with some problems in signal processing and wireless sensor networks. Also, fusion frames are an important extension of frames, used in many areas especially for wireless sensor networks. In this paper, we survey the notion of weaving Hilbert space fusion frames. This concept can be had potential applications in wireless sensor networks which require distributed processing using different fusion frames...
Frames and bases in tensor products of Hilbert spaces and Hilbert C ...
Indian Academy of Sciences (India)
In this article, we study tensor product of Hilbert *-modules and Hilbert spaces. We show that if is a Hilbert -module and is a Hilbert -module, then tensor product of frames (orthonormal bases) for and produce frames (orthonormal bases) for Hilbert A ⊗ B -module E ⊗ F , and we get more results. For Hilbert ...
Means of Hilbert space operators
Hiai, Fumio
2003-01-01
The monograph is devoted to a systematic study of means of Hilbert space operators by a unified method based on the theory of double integral transformations and Peller's characterization of Schur multipliers. General properties on means of operators such as comparison results, norm estimates and convergence criteria are established. After some general theory, special investigations are focused on three one-parameter families of A-L-G (arithmetic-logarithmic-geometric) interpolation means, Heinz-type means and binomial means. In particular, norm continuity in the parameter is examined for such means. Some necessary technical results are collected as appendices.
Structure of Hilbert space operators
Jiang, Chunlan
2006-01-01
This book exposes the internal structure of non-self-adjoint operators acting on complex separable infinite dimensional Hilbert space, by analyzing and studying the commutant of operators. A unique presentation of the theorem of Cowen-Douglas operators is given. The authors take the strongly irreducible operator as a basic model, and find complete similarity invariants of Cowen-Douglas operators by using K -theory, complex geometry and operator algebra tools. Sample Chapter(s). Chapter 1: Background (153 KB). Contents: Jordan Standard Theorem and K 0 -Group; Approximate Jordan Theorem of Opera
Rigged Hilbert spaces for chaotic dynamical systems
International Nuclear Information System (INIS)
Suchanecki, Z.; Antoniou, I.; Bandtlow, O.F.
1996-01-01
We consider the problem of rigging for the Koopman operators of the Renyi and the baker maps. We show that the rigged Hilbert space for the Renyi maps has some of the properties of a strict inductive limit and give a detailed description of the rigged Hilbert space for the baker maps. copyright 1996 American Institute of Physics
Quantum theory in complex Hilbert space
International Nuclear Information System (INIS)
Sharma, C.S.
1988-01-01
The theory of complexification of a real Hilbert space as developed by the author is scrutinized with the aim of explaining why quantum theory should be done in a complex Hilbert space in preference to real Hilbert space. It is suggested that, in order to describe periodic motions in stationary states of a quantum system, the mathematical object modelling a state of a system should have enough points in it to be able to describe explicit time dependence of a periodic motion without affecting the probability distributions of observables. Heuristic evidence for such an assumption comes from Dirac's theory of interaction between radiation and matter. If the assumption is adopted as a requirement on the mathematical model for a quantum system, then a real Hilbert space is ruled out in favour of a complex Hilbert space for a possible model for such a system
Hilbert space methods in partial differential equations
Showalter, Ralph E
1994-01-01
This graduate-level text opens with an elementary presentation of Hilbert space theory sufficient for understanding the rest of the book. Additional topics include boundary value problems, evolution equations, optimization, and approximation.1979 edition.
Theory of linear operators in Hilbert space
Akhiezer, N I
1993-01-01
This classic textbook by two mathematicians from the USSR's prestigious Kharkov Mathematics Institute introduces linear operators in Hilbert space, and presents in detail the geometry of Hilbert space and the spectral theory of unitary and self-adjoint operators. It is directed to students at graduate and advanced undergraduate levels, but because of the exceptional clarity of its theoretical presentation and the inclusion of results obtained by Soviet mathematicians, it should prove invaluable for every mathematician and physicist. 1961, 1963 edition.
Transverse entanglement migration in Hilbert space
International Nuclear Information System (INIS)
Chan, K. W.; Torres, J. P.; Eberly, J. H.
2007-01-01
We show that, although the amount of mutual entanglement of photons propagating in free space is fixed, the type of correlations between the photons that determine the entanglement can dramatically change during propagation. We show that this amounts to a migration of entanglement in Hilbert space, rather than real space. For the case of spontaneous parametric down-conversion, the migration of entanglement in transverse coordinates takes place from modulus to phase of the biphoton state and back again. We propose an experiment to observe this migration in Hilbert space and to determine the full entanglement
κ-Minkowski representations on Hilbert spaces
International Nuclear Information System (INIS)
Agostini, Alessandra
2007-01-01
The algebra of functions on κ-Minkowski noncommutative space-time is studied as algebra of operators on Hilbert spaces. The representations of this algebra are constructed and classified. This new approach leads to a natural construction of integration in κ-Minkowski space-time in terms of the usual trace of operators
Spectral Theory of Operators on Hilbert Spaces
Kubrusly, Carlos S
2012-01-01
This work is a concise introduction to spectral theory of Hilbert space operators. Its emphasis is on recent aspects of theory and detailed proofs, with the primary goal of offering a modern introductory textbook for a first graduate course in the subject. The coverage of topics is thorough, as the book explores various delicate points and hidden features often left untreated. Spectral Theory of Operators on Hilbert Space is addressed to an interdisciplinary audience of graduate students in mathematics, statistics, economics, engineering, and physics. It will also be useful to working mathemat
The role of the rigged Hilbert space in quantum mechanics
International Nuclear Information System (INIS)
Madrid, Rafael de la
2005-01-01
There is compelling evidence that, when a continuous spectrum is present, the natural mathematical setting for quantum mechanics is the rigged Hilbert space rather than just the Hilbert space. In particular, Dirac's braket formalism is fully implemented by the rigged Hilbert space rather than just by the Hilbert space. In this paper, we provide a pedestrian introduction to the role the rigged Hilbert space plays in quantum mechanics, by way of a simple, exactly solvable example. The procedure will be constructive and based on a recent publication. We also provide a thorough discussion on the physical significance of the rigged Hilbert space
Reproducing kernel Hilbert spaces of Gaussian priors
Vaart, van der A.W.; Zanten, van J.H.; Clarke, B.; Ghosal, S.
2008-01-01
We review definitions and properties of reproducing kernel Hilbert spaces attached to Gaussian variables and processes, with a view to applications in nonparametric Bayesian statistics using Gaussian priors. The rate of contraction of posterior distributions based on Gaussian priors can be described
Invariant Hilbert spaces of holomorphic functions
Faraut, J; Thomas, EGF
1999-01-01
A Hilbert space of holomorphic functions on a complex manifold Z, which is invariant under a group G of holomorphic automorphisms of Z, can be decomposed into irreducible subspaces by using Choquet theory. We give a geometric condition on Z and G which implies that this decomposition is multiplicity
Hilbert space theory of classical electrodynamics
Indian Academy of Sciences (India)
Hilbert space; Koopman–von Neumann theory; classical electrodynamics. PACS No. 03.50. ... The paper is divided into four sections. Section 2 .... construction of Sudarshan is to be contrasted with that of Koopman and von Neumann. ..... ture from KvN and [16] in this formulation is to define new momentum and coordinate.
Vertical integration from the large Hilbert space
Erler, Theodore; Konopka, Sebastian
2017-12-01
We develop an alternative description of the procedure of vertical integration based on the observation that amplitudes can be written in BRST exact form in the large Hilbert space. We relate this approach to the description of vertical integration given by Sen and Witten.
Elements of Hilbert spaces and operator theory
Vasudeva, Harkrishan Lal
2017-01-01
The book presents an introduction to the geometry of Hilbert spaces and operator theory, targeting graduate and senior undergraduate students of mathematics. Major topics discussed in the book are inner product spaces, linear operators, spectral theory and special classes of operators, and Banach spaces. On vector spaces, the structure of inner product is imposed. After discussing geometry of Hilbert spaces, its applications to diverse branches of mathematics have been studied. Along the way are introduced orthogonal polynomials and their use in Fourier series and approximations. Spectrum of an operator is the key to the understanding of the operator. Properties of the spectrum of different classes of operators, such as normal operators, self-adjoint operators, unitaries, isometries and compact operators have been discussed. A large number of examples of operators, along with their spectrum and its splitting into point spectrum, continuous spectrum, residual spectrum, approximate point spectrum and compressio...
Convexity Of Inversion For Positive Operators On A Hilbert Space
International Nuclear Information System (INIS)
Sangadji
2001-01-01
This paper discusses and proves three theorems for positive invertible operators on a Hilbert space. The first theorem gives a comparison of the generalized arithmetic mean, generalized geometric mean, and generalized harmonic mean for positive invertible operators on a Hilbert space. For the second and third theorems each gives three inequalities for positive invertible operators on a Hilbert space that are mutually equivalent
Resonances, scattering theory and rigged Hilbert spaces
International Nuclear Information System (INIS)
Parravicini, G.; Gorini, V.; Sudarshan, E.C.G.
1979-01-01
The problem of decaying states and resonances is examined within the framework of scattering theory in a rigged Hilbert space formalism. The stationary free, in, and out eigenvectors of formal scattering theory, which have a rigorous setting in rigged Hilbert space, are considered to be analytic functions of the energy eigenvalue. The value of these analytic functions at any point of regularity, real or complex, is an eigenvector with eigenvalue equal to the position of the point. The poles of the eigenvector families give origin to other eigenvectors of the Hamiltonian; the singularities of the out eigenvector family are the same as those of the continued S matrix, so that resonances are seen as eigenvectors of the Hamiltonian with eigenvalue equal to their location in the complex energy plane. Cauchy theorem then provides for expansions in terms of complete sets of eigenvectors with complex eigenvalues of the Hamiltonian. Applying such expansions to the survival amplitude of a decaying state, one finds that resonances give discrete contributions with purely exponential time behavior; the background is of course present, but explicitly separated. The resolvent of the Hamiltonian, restricted to the nuclear space appearing in the rigged Hilbert space, can be continued across the absolutely continuous spectrum; the singularities of the continuation are the same as those of the out eigenvectors. The free, in and out eigenvectors with complex eigenvalues and those corresponding to resonances can be approximated by physical vectors in the Hilbert space, as plane waves can. The need for having some further physical information in addition to the specification of the total Hamiltonian is apparent in the proposed framework. The formalism is applied to the Lee-Friedrichs model. 48 references
Semiclassical propagation: Hilbert space vs. Wigner representation
Gottwald, Fabian; Ivanov, Sergei D.
2018-03-01
A unified viewpoint on the van Vleck and Herman-Kluk propagators in Hilbert space and their recently developed counterparts in Wigner representation is presented. Based on this viewpoint, the Wigner Herman-Kluk propagator is conceptually the most general one. Nonetheless, the respective semiclassical expressions for expectation values in terms of the density matrix and the Wigner function are mathematically proven here to coincide. The only remaining difference is a mere technical flexibility of the Wigner version in choosing the Gaussians' width for the underlying coherent states beyond minimal uncertainty. This flexibility is investigated numerically on prototypical potentials and it turns out to provide neither qualitative nor quantitative improvements. Given the aforementioned generality, utilizing the Wigner representation for semiclassical propagation thus leads to the same performance as employing the respective most-developed (Hilbert-space) methods for the density matrix.
Frames and bases in tensor products of Hilbert spaces and Hilbert C ...
Indian Academy of Sciences (India)
[14] Heil C E and Walnut D F, Continuous and discrete wavelet transforms, SIAM Review 31. (1989) 628–666. [15] Khosravi A and Asgari M S, Frames and bases in tensor product of Hilbert spaces, Int. J. Math. 4(6) (2003) 527–538. [16] Lance E C, Hilbert C. ∗. -modules – a toolkit for operator algebraists, London Math. Soc.
Unstable quantum states and rigged Hilbert spaces
International Nuclear Information System (INIS)
Gorini, V.; Parravicini, G.
1978-10-01
Rigged Hilbert space techniques are applied to the quantum mechanical treatment of unstable states in nonrelativistic scattering theory. A method is discussed which is based on representations of decay amplitudes in terms of expansions over complete sets of generalized eigenvectors of the interacting Hamiltonian, corresponding to complex eigenvalues. These expansions contain both a discrete and a continuum contribution. The former corresponds to eigenvalues located at the second sheet poles of the S matrix, and yields the exponential terms in the survival amplitude. The latter arises from generalized eigenvectors associated to complex eigenvalues on background contours in the complex plane, and gives the corrections to the exponential law. 27 references
Adaptive Learning in Cartesian Product of Reproducing Kernel Hilbert Spaces
Yukawa, Masahiro
2014-01-01
We propose a novel adaptive learning algorithm based on iterative orthogonal projections in the Cartesian product of multiple reproducing kernel Hilbert spaces (RKHSs). The task is estimating/tracking nonlinear functions which are supposed to contain multiple components such as (i) linear and nonlinear components, (ii) high- and low- frequency components etc. In this case, the use of multiple RKHSs permits a compact representation of multicomponent functions. The proposed algorithm is where t...
Open superstring field theory on the restricted Hilbert space
International Nuclear Information System (INIS)
Konopka, Sebastian; Sachs, Ivo
2016-01-01
It appears that the formulation of an action for the Ramond sector of open superstring field theory requires to either restrict the Hilbert space for the Ramond sector or to introduce auxiliary fields with picture −3/2. The purpose of this note is to clarify the relation of the restricted Hilbert space with other approaches and to formulate open superstring field theory entirely in the small Hilbert space.
Quantum mechanics in an evolving Hilbert space
Artacho, Emilio; O'Regan, David D.
2017-03-01
Many basis sets for electronic structure calculations evolve with varying external parameters, such as moving atoms in dynamic simulations, giving rise to extra derivative terms in the dynamical equations. Here we revisit these derivatives in the context of differential geometry, thereby obtaining a more transparent formalization, and a geometrical perspective for better understanding the resulting equations. The effect of the evolution of the basis set within the spanned Hilbert space separates explicitly from the effect of the turning of the space itself when moving in parameter space, as the tangent space turns when moving in a curved space. New insights are obtained using familiar concepts in that context such as the Riemann curvature. The differential geometry is not strictly that for curved spaces as in general relativity, a more adequate mathematical framework being provided by fiber bundles. The language used here, however, will be restricted to tensors and basic quantum mechanics. The local gauge implied by a smoothly varying basis set readily connects with Berry's formalism for geometric phases. Generalized expressions for the Berry connection and curvature are obtained for a parameter-dependent occupied Hilbert space spanned by nonorthogonal Wannier functions. The formalism is applicable to basis sets made of atomic-like orbitals and also more adaptative moving basis functions (such as in methods using Wannier functions as intermediate or support bases), but should also apply to other situations in which nonorthogonal functions or related projectors should arise. The formalism is applied to the time-dependent quantum evolution of electrons for moving atoms. The geometric insights provided here allow us to propose new finite-difference time integrators, and also better understand those already proposed.
Eigenfunction expansions and scattering theory in rigged Hilbert spaces
Energy Technology Data Exchange (ETDEWEB)
Gomez-Cubillo, F [Dpt. de Analisis Matematico, Universidad de Valladolid. Facultad de Ciencias, 47011 Valladolid (Spain)], E-mail: fgcubill@am.uva.es
2008-08-15
The work reviews some mathematical aspects of spectral properties, eigenfunction expansions and scattering theory in rigged Hilbert spaces, laying emphasis on Lippmann-Schwinger equations and Schroedinger operators.
Quantum holonomy theory and Hilbert space representations
Energy Technology Data Exchange (ETDEWEB)
Aastrup, Johannes [Mathematisches Institut, Universitaet Hannover (Germany); Moeller Grimstrup, Jesper [QHT Gruppen, Copenhagen Area (Denmark)
2016-11-15
We present a new formulation of quantum holonomy theory, which is a candidate for a non-perturbative and background independent theory of quantum gravity coupled to matter and gauge degrees of freedom. The new formulation is based on a Hilbert space representation of the QHD(M) algebra, which is generated by holonomy-diffeomorphisms on a 3-dimensional manifold and by canonical translation operators on the underlying configuration space over which the holonomy-diffeomorphisms form a non-commutative C*-algebra. A proof that the state that generates the representation exist is left for later publications. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Multipliers for continuous frames in Hilbert spaces
International Nuclear Information System (INIS)
Balazs, P; Bayer, D; Rahimi, A
2012-01-01
In this paper, we examine the general theory of continuous frame multipliers in Hilbert space. These operators are a generalization of the widely used notion of (discrete) frame multipliers. Well-known examples include anti-Wick operators, STFT multipliers or Calderón–Toeplitz operators. Due to the possible peculiarities of the underlying measure spaces, continuous frames do not behave quite as their discrete counterparts. Nonetheless, many results similar to the discrete case are proven for continuous frame multipliers as well, for instance compactness and Schatten-class properties. Furthermore, the concepts of controlled and weighted frames are transferred to the continuous setting. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’. (paper)
A note on tensor fields in Hilbert spaces
Directory of Open Access Journals (Sweden)
LEONARDO BILIOTTI
2002-06-01
Full Text Available We discuss and extend to infinite dimensional Hilbert spaces a well-known tensoriality criterion for linear endomorphisms of the space of smooth vector fields in n.Discutimos e estendemos para espaços de Hilbert um critério de tensorialidade para endomorfismos do espaço dos campos vetoriais em Rpot(n.
ON STRONG AND WEAK CONVERGENCE IN n-HILBERT SPACES
Directory of Open Access Journals (Sweden)
Agus L. Soenjaya
2014-03-01
Full Text Available We discuss the concepts of strong and weak convergence in n-Hilbert spaces and study their properties. Some examples are given to illustrate the concepts. In particular, we prove an analogue of Banach-Saks-Mazur theorem and Radon-Riesz property in the case of n-Hilbert space.
Hilbert space, Poincare dodecahedron and golden mean transfiniteness
International Nuclear Information System (INIS)
El Naschie, M.S.
2007-01-01
A rather direct connection between Hilbert space and E-infinity theory is established via an irrational-transfinite golden mean topological probability. Subsequently the ramifications for Kleinian modular spaces and the cosmological Poincare Dodecahedron proposals are considered
Isometric Reflection Vectors and Characterizations of Hilbert Spaces
Directory of Open Access Journals (Sweden)
Donghai Ji
2014-01-01
Full Text Available A known characterization of Hilbert spaces via isometric reflection vectors is based on the following implication: if the set of isometric reflection vectors in the unit sphere SX of a Banach space X has nonempty interior in SX, then X is a Hilbert space. Applying a recent result based on well-known theorem of Kronecker from number theory, we improve this by substantial reduction of the set of isometric reflection vectors needed in the hypothesis.
Aveiro method in reproducing kernel Hilbert spaces under complete dictionary
Mai, Weixiong; Qian, Tao
2017-12-01
Aveiro Method is a sparse representation method in reproducing kernel Hilbert spaces (RKHS) that gives orthogonal projections in linear combinations of reproducing kernels over uniqueness sets. It, however, suffers from determination of uniqueness sets in the underlying RKHS. In fact, in general spaces, uniqueness sets are not easy to be identified, let alone the convergence speed aspect with Aveiro Method. To avoid those difficulties we propose an anew Aveiro Method based on a dictionary and the matching pursuit idea. What we do, in fact, are more: The new Aveiro method will be in relation to the recently proposed, the so called Pre-Orthogonal Greedy Algorithm (P-OGA) involving completion of a given dictionary. The new method is called Aveiro Method Under Complete Dictionary (AMUCD). The complete dictionary consists of all directional derivatives of the underlying reproducing kernels. We show that, under the boundary vanishing condition, bring available for the classical Hardy and Paley-Wiener spaces, the complete dictionary enables an efficient expansion of any given element in the Hilbert space. The proposed method reveals new and advanced aspects in both the Aveiro Method and the greedy algorithm.
Introduction to Hilbert space and the theory of spectral multiplicity
Halmos, Paul R
2017-01-01
Concise introductory treatment consists of three chapters: The Geometry of Hilbert Space, The Algebra of Operators, and The Analysis of Spectral Measures. A background in measure theory is the sole prerequisite. 1957 edition.
Alabiso, Carlo
2015-01-01
This book is an introduction to the theory of Hilbert space, a fundamental tool for non-relativistic quantum mechanics. Linear, topological, metric, and normed spaces are all addressed in detail, in a rigorous but reader-friendly fashion. The rationale for an introduction to the theory of Hilbert space, rather than a detailed study of Hilbert space theory itself, resides in the very high mathematical difficulty of even the simplest physical case. Within an ordinary graduate course in physics there is insufficient time to cover the theory of Hilbert spaces and operators, as well as distribution theory, with sufficient mathematical rigor. Compromises must be found between full rigor and practical use of the instruments. The book is based on the author's lessons on functional analysis for graduate students in physics. It will equip the reader to approach Hilbert space and, subsequently, rigged Hilbert space, with a more practical attitude. With respect to the original lectures, the mathematical flavor in all sub...
Diagonalization of Bounded Linear Operators on Separable Quaternionic Hilbert Space
International Nuclear Information System (INIS)
Feng Youling; Cao, Yang; Wang Haijun
2012-01-01
By using the representation of its complex-conjugate pairs, we have investigated the diagonalization of a bounded linear operator on separable infinite-dimensional right quaternionic Hilbert space. The sufficient condition for diagonalizability of quaternionic operators is derived. The result is applied to anti-Hermitian operators, which is essential for solving Schroedinger equation in quaternionic quantum mechanics.
On Some Fractional Stochastic Integrodifferential Equations in Hilbert Space
Directory of Open Access Journals (Sweden)
Hamdy M. Ahmed
2009-01-01
Full Text Available We study a class of fractional stochastic integrodifferential equations considered in a real Hilbert space. The existence and uniqueness of the Mild solutions of the considered problem is also studied. We also give an application for stochastic integropartial differential equations of fractional order.
Ad Hoc Physical Hilbert Spaces in Quantum Mechanics
Czech Academy of Sciences Publication Activity Database
Fernandez, F. M.; Garcia, J.; Semorádová, Iveta; Znojil, Miloslav
2015-01-01
Roč. 54, č. 12 (2015), s. 4187-4203 ISSN 0020-7748 Institutional support: RVO:61389005 Keywords : quantum mechanics * physical Hilbert spaces * ad hoc inner product * singular potentials regularized * low lying energies Subject RIV: BE - Theoretical Physics Impact factor: 1.041, year: 2015
A Hilbert space structure on Banach algebras
International Nuclear Information System (INIS)
Mohammad, N.; Thaheem, A.B.
1988-08-01
In this note we define an inner product on ''reduced'' Banach *-algebras via a measure on the set of positive functionals. It is shown here that the resultant inner product space is a topological algebra and also a completeness condition is obtained. (author). 9 refs
The Hilbert Series of the One Instanton Moduli Space
Benvenuti, Sergio; Mekareeya, Noppadol; 10.1007
2010-01-01
The moduli space of k G-instantons on R^4 for a classical gauge group G is known to be given by the Higgs branch of a supersymmetric gauge theory that lives on Dp branes probing D(p + 4) branes in Type II theories. For p = 3, these (3 + 1) dimensional gauge theories have N = 2 supersymmetry and can be represented by quiver diagrams. The F and D term equations coincide with the ADHM construction. The Hilbert series of the moduli spaces of one instanton for classical gauge groups is easy to compute and turns out to take a particularly simple form which is previously unknown. This allows for a G invariant character expansion and hence easily generalisable for exceptional gauge groups, where an ADHM construction is not known. The conjectures for exceptional groups are further checked using some new techniques like sewing relations in Hilbert Series. This is applied to Argyres-Seiberg dualities.
The method of moments and nested Hilbert spaces in quantum mechanics
International Nuclear Information System (INIS)
Adeniyi Bangudu, E.
1980-08-01
It is shown how the structures of a nested Hilbert space Hsub(I), associated with a given Hilbert space Hsub(O), may be used to simplify our understanding of the effects of parameters, whose values have to be chosen rather than determined variationally, in the method of moments. The result, as applied to non-relativistic quartic oscillator and helium atom, is to associate the parameters with sequences of Hilbert spaces, while the error of the method of moments relative to the variational method corresponds to a nesting operator of the nested Hilbert space. Difficulties hindering similar interpretations in terms of rigged Hilbert space structures are highlighted. (author)
Moretti, Valter; Oppio, Marco
As earlier conjectured by several authors and much later established by Solèr (relying on partial results by Piron, Maeda-Maeda and other authors), from the lattice theory point of view, Quantum Mechanics may be formulated in real, complex or quaternionic Hilbert spaces only. Stückelberg provided some physical, but not mathematically rigorous, reasons for ruling out the real Hilbert space formulation, assuming that any formulation should encompass a statement of Heisenberg principle. Focusing on this issue from another — in our opinion, deeper — viewpoint, we argue that there is a general fundamental reason why elementary quantum systems are not described in real Hilbert spaces. It is their basic symmetry group. In the first part of the paper, we consider an elementary relativistic system within Wigner’s approach defined as a locally-faithful irreducible strongly-continuous unitary representation of the Poincaré group in a real Hilbert space. We prove that, if the squared-mass operator is non-negative, the system admits a natural, Poincaré invariant and unique up to sign, complex structure which commutes with the whole algebra of observables generated by the representation itself. This complex structure leads to a physically equivalent reformulation of the theory in a complex Hilbert space. Within this complex formulation, differently from what happens in the real one, all selfadjoint operators represent observables in accordance with Solèr’s thesis, and the standard quantum version of Noether theorem may be formulated. In the second part of this work, we focus on the physical hypotheses adopted to define a quantum elementary relativistic system relaxing them on the one hand, and making our model physically more general on the other hand. We use a physically more accurate notion of irreducibility regarding the algebra of observables only, we describe the symmetries in terms of automorphisms of the restricted lattice of elementary propositions of the
Real analysis measure theory, integration, and Hilbert spaces
Stein, Elias M
2005-01-01
Real Analysis is the third volume in the Princeton Lectures in Analysis, a series of four textbooks that aim to present, in an integrated manner, the core areas of analysis. Here the focus is on the development of measure and integration theory, differentiation and integration, Hilbert spaces, and Hausdorff measure and fractals. This book reflects the objective of the series as a whole: to make plain the organic unity that exists between the various parts of the subject, and to illustrate the wide applicability of ideas of analysis to other fields of mathematics and science. After
Geometry of quantum dynamics in infinite-dimensional Hilbert space
Grabowski, Janusz; Kuś, Marek; Marmo, Giuseppe; Shulman, Tatiana
2018-04-01
We develop a geometric approach to quantum mechanics based on the concept of the Tulczyjew triple. Our approach is genuinely infinite-dimensional, i.e. we do not restrict considerations to finite-dimensional Hilbert spaces, contrary to many other works on the geometry of quantum mechanics, and include a Lagrangian formalism in which self-adjoint (Schrödinger) operators are obtained as Lagrangian submanifolds associated with the Lagrangian. As a byproduct we also obtain results concerning coadjoint orbits of the unitary group in infinite dimensions, embedding of pure states in the unitary group, and self-adjoint extensions of symmetric relations.
On convergence of nuclear and correlation operators in Hilbert space
International Nuclear Information System (INIS)
Kubrusly, C.S.
1985-01-01
The convergence of sequences of nuclear operators on a separable Hilbert space is studied. Emphasis is given to trace-norm convergence, which is a basic property in stochastic systems theory. Obviously trace-norm convergence implies uniform convergence. The central theme of the paper focus the opposite way, by investigating when convergence in a weaker topology turns out to imply convergence in a stronger topology. The analysis carried out here is exhaustive in the following sense. All possible implications within a selected set of asymptotic properties for sequences of nuclear operators are established. The special case of correlation operators is also considered in detail. (Author) [pt
Perturbation for Frames for a Subspace of a Hilbert Space
DEFF Research Database (Denmark)
Christensen, Ole; deFlicht, C.; Lennard, C.
1997-01-01
We extend a classical result stating that a sufficiently small perturbation$\\{ g_i \\}$ of a Riesz sequence $\\{ f_i \\}$ in a Hilbert space $H$ is again a Riesz sequence. It turns out that the analog result for a frame does not holdunless the frame is complete. However, we are able to prove a very...... similarresult for frames in the case where the gap between the subspaces$\\overline{span} \\{f_i \\}$ and $\\overline{span} \\{ g_i \\}$ is small enough. We give a geometric interpretation of the result....
Explicit signal to noise ratio in reproducing kernel Hilbert spaces
DEFF Research Database (Denmark)
Gomez-Chova, Luis; Nielsen, Allan Aasbjerg; Camps-Valls, Gustavo
2011-01-01
This paper introduces a nonlinear feature extraction method based on kernels for remote sensing data analysis. The proposed approach is based on the minimum noise fraction (MNF) transform, which maximizes the signal variance while also minimizing the estimated noise variance. We here propose...... an alternative kernel MNF (KMNF) in which the noise is explicitly estimated in the reproducing kernel Hilbert space. This enables KMNF dealing with non-linear relations between the noise and the signal features jointly. Results show that the proposed KMNF provides the most noise-free features when confronted...
Friedrichs systems in a Hilbert space framework: Solvability and multiplicity
Antonić, N.; Erceg, M.; Michelangeli, A.
2017-12-01
The Friedrichs (1958) theory of positive symmetric systems of first order partial differential equations encompasses many standard equations of mathematical physics, irrespective of their type. This theory was recast in an abstract Hilbert space setting by Ern, Guermond and Caplain (2007), and by Antonić and Burazin (2010). In this work we make a further step, presenting a purely operator-theoretic description of abstract Friedrichs systems, and proving that any pair of abstract Friedrichs operators admits bijective extensions with a signed boundary map. Moreover, we provide sufficient and necessary conditions for existence of infinitely many such pairs of spaces, and by the universal operator extension theory (Grubb, 1968) we get a complete identification of all such pairs, which we illustrate on two concrete one-dimensional examples.
Convex analysis and monotone operator theory in Hilbert spaces
Bauschke, Heinz H
2017-01-01
This reference text, now in its second edition, offers a modern unifying presentation of three basic areas of nonlinear analysis: convex analysis, monotone operator theory, and the fixed point theory of nonexpansive operators. Taking a unique comprehensive approach, the theory is developed from the ground up, with the rich connections and interactions between the areas as the central focus, and it is illustrated by a large number of examples. The Hilbert space setting of the material offers a wide range of applications while avoiding the technical difficulties of general Banach spaces. The authors have also drawn upon recent advances and modern tools to simplify the proofs of key results making the book more accessible to a broader range of scholars and users. Combining a strong emphasis on applications with exceptionally lucid writing and an abundance of exercises, this text is of great value to a large audience including pure and applied mathematicians as well as researchers in engineering, data science, ma...
Hamiltonian and physical Hilbert space in polymer quantum mechanics
International Nuclear Information System (INIS)
Corichi, Alejandro; Vukasinac, Tatjana; Zapata, Jose A
2007-01-01
In this paper, a version of polymer quantum mechanics, which is inspired by loop quantum gravity, is considered and shown to be equivalent, in a precise sense, to the standard, experimentally tested Schroedinger quantum mechanics. The kinematical cornerstone of our framework is the so-called polymer representation of the Heisenberg-Weyl (HW) algebra, which is the starting point of the construction. The dynamics is constructed as a continuum limit of effective theories characterized by a scale, and requires a renormalization of the inner product. The result is a physical Hilbert space in which the continuum Hamiltonian can be represented and that is unitarily equivalent to the Schroedinger representation of quantum mechanics. As a concrete implementation of our formalism, the simple harmonic oscillator is fully developed
Galerkin approximations of nonlinear optimal control problems in Hilbert spaces
Directory of Open Access Journals (Sweden)
Mickael D. Chekroun
2017-07-01
Full Text Available Nonlinear optimal control problems in Hilbert spaces are considered for which we derive approximation theorems for Galerkin approximations. Approximation theorems are available in the literature. The originality of our approach relies on the identification of a set of natural assumptions that allows us to deal with a broad class of nonlinear evolution equations and cost functionals for which we derive convergence of the value functions associated with the optimal control problem of the Galerkin approximations. This convergence result holds for a broad class of nonlinear control strategies as well. In particular, we show that the framework applies to the optimal control of semilinear heat equations posed on a general compact manifold without boundary. The framework is then shown to apply to geoengineering and mitigation of greenhouse gas emissions formulated here in terms of optimal control of energy balance climate models posed on the sphere $\\mathbb{S}^2$.
International Nuclear Information System (INIS)
Khrennikov, A.
2005-01-01
We constructed the representation of contextual probabilistic dynamics in the complex Hilbert space. Thus dynamics of the wave function can be considered as Hilbert space projection of realistic dynamics in a pre space. The basic condition for representing the pre space-dynamics is the law of statistical conservation of energy-conservation of probabilities. The construction of the dynamical representation is an important step in the development of contextual statistical viewpoint of quantum processes. But the contextual statistical model is essentially more general than the quantum one. Therefore in general the Hilbert space projection of the pre space dynamics can be nonlinear and even irreversible (but it is always unitary). There were found conditions of linearity and reversibility of the Hilbert space dynamical projection. We also found conditions for the conventional Schrodinger dynamics (including time-dependent Hamiltonians). We remark that in general even the Schrodinger dynamics is based just on the statistical conservation of energy; for individual systems the law of conservation of energy can be violated (at least in our theoretical model)
International Nuclear Information System (INIS)
Luks, A.; Perinova, V.
1993-01-01
A suitable ordering of phase exponential operators has been compared with the antinormal ordering of the annihilation and creation operators of a single mode optical field. The extended Wigner function for number and phase in the enlarged Hilbert space has been used for the derivation of the Wigner function for number and phase in the original Hilbert space. (orig.)
The kinematical Hilbert space of loop quantum gravity from BF theories
International Nuclear Information System (INIS)
Cianfrani, Francesco
2011-01-01
In this work, it is demonstrated how the kinematical Hilbert space of loop quantum gravity (LQG) can be inferred from the configuration space of BF theories via the imposition of the Hamiltonian constraints. In particular, it is outlined how the projection to the representations associated with Ashtekar-Barbero connections provides the correct procedure to implement second-class constraints and the corresponding nontrivial induced symplectic structure. Then, the reduction to SU(2) invariant intertwiners is analyzed and the properties of LQG states under Lorentz transformations are discussed.
Continuous Slice Functional Calculus in Quaternionic Hilbert Spaces
Ghiloni, Riccardo; Moretti, Valter; Perotti, Alessandro
2013-04-01
The aim of this work is to define a continuous functional calculus in quaternionic Hilbert spaces, starting from basic issues regarding the notion of spherical spectrum of a normal operator. As properties of the spherical spectrum suggest, the class of continuous functions to consider in this setting is the one of slice quaternionic functions. Slice functions generalize the concept of slice regular function, which comprises power series with quaternionic coefficients on one side and that can be seen as an effective generalization to quaternions of holomorphic functions of one complex variable. The notion of slice function allows to introduce suitable classes of real, complex and quaternionic C*-algebras and to define, on each of these C*-algebras, a functional calculus for quaternionic normal operators. In particular, we establish several versions of the spectral map theorem. Some of the results are proved also for unbounded operators. However, the mentioned continuous functional calculi are defined only for bounded normal operators. Some comments on the physical significance of our work are included.
Characterizing sequential isomorphisms on Hilbert-space effect algebras
International Nuclear Information System (INIS)
Hou Jinchuan; He Kan; Qi Xiaofei
2010-01-01
Let * be any sequential product on the Hilbert-space effect algebra E(H) with dim H≥2, and Φ:E(H)→E(H) be a bijective map. We show that if Φ satisfies Φ(A*B) = Φ(A)*Φ(B) for A,B element of E(H), then there is either a unitary or an anti-unitary operator U such that Φ(A) = UAU† for every A element of E(H). Let g:[0,1]→{λ|λ element of C, |λ|=0 or 1} be a Borel function satisfying g(0) = 0, g(1) = 1 and let us define a binary operation lozenge g on E(H) by A lozenge g B = A 1/2 g(A)Bg(A)†A 1/2 , where T† denotes the conjugate of the operator T. We also show that a bijective map Φ:E(H)→E(H) satisfies Φ(A lozenge g B) = Φ(A) lozenge g Φ(B) for A,B element of E(H) if and only if there is either a unitary or an anti-unitary operator U such that Φ(A) = UAU† for every A element of E(H).
States in the Hilbert space formulation and in the phase space formulation of quantum mechanics
International Nuclear Information System (INIS)
Tosiek, J.; Brzykcy, P.
2013-01-01
We consider the problem of testing whether a given matrix in the Hilbert space formulation of quantum mechanics or a function considered in the phase space formulation of quantum theory represents a quantum state. We propose several practical criteria for recognising states in these two versions of quantum physics. After minor modifications, they can be applied to check positivity of any operators acting in a Hilbert space or positivity of any functions from an algebra with a ∗-product of Weyl type. -- Highlights: ► Methods of testing whether a given matrix represents a quantum state. ► The Stratonovich–Weyl correspondence on an arbitrary symplectic manifold. ► Criteria for checking whether a function on a symplectic space is a Wigner function
Wiener-Hopf operators on spaces of functions on R+ with values in a Hilbert space
Petkova, Violeta
2006-01-01
A Wiener-Hopf operator on a Banach space of functions on R+ is a bounded operator T such that P^+S_{-a}TS_a=T, for every positive a, where S_a is the operator of translation by a. We obtain a representation theorem for the Wiener-Hopf operators on a large class of functions on R+ with values in a separable Hilbert space.
Hilbert spaces contractively included in the Hardy space of the bidisk
Alpay, D.; Bolotnikov, V.; Dijksma, A.; Sadosky, C.
We study the reproducing kernel Hilbert spaces h(D-2,S) with kernels of the form I-S(z(1),z(2)>)S(w(1),w(2))*/(1-z(1)w(1)*) (1-z(2)w(2)*) where S(z(1),z(2)) is a Schur function of two variables z(1),z(2)is an element of D. They are analogs of the spaces h(D,S) with reproducing kernel
Generalized Polar Decompositions for Closed Operators in Hilbert Spaces and Some Applications
Gesztesy, Fritz; Malamud, Mark; Mitrea, Marius; Naboko, Serguei
2008-01-01
We study generalized polar decompositions of densely defined, closed linear operators in Hilbert spaces and provide some applications to relatively (form) bounded and relatively (form) compact perturbations of self-adjoint, normal, and m-sectorial operators.
Positive-definite functions and unitary representations of locally compact groups in a Hilbert space
International Nuclear Information System (INIS)
Gali, I.M.; Okb el-Bab, A.S.; Hassan, H.M.
1977-08-01
It is proved that the necessary and sufficient condition for the existence of an integral representation of a group of unitary operators in a Hilbert space is that it is positive-definite and continuous in some topology
On the minimizers of calculus of variations problems in Hilbert spaces
Gomes, Diogo A.
2014-01-19
The objective of this paper is to discuss existence, uniqueness and regularity issues of minimizers of one dimensional calculus of variations problem in Hilbert spaces. © 2014 Springer-Verlag Berlin Heidelberg.
On the minimizers of calculus of variations problems in Hilbert spaces
Gomes, Diogo A.; Nurbekyan, Levon
2014-01-01
The objective of this paper is to discuss existence, uniqueness and regularity issues of minimizers of one dimensional calculus of variations problem in Hilbert spaces. © 2014 Springer-Verlag Berlin Heidelberg.
An introduction of gauge field by the Lie-isotopic lifting of the Hilbert space
International Nuclear Information System (INIS)
Nishioka, M.
1984-01-01
It is introduced the gauge field by the Lie-isotopic lifting of the Hilbert space. Our method is different from other's in that the commutator between the isotropic element and the generators of the Lie algebra does not vanish in our case, but vanishes in other cases. Our method uses the Lie-isotopic lifting of the Hilbert space, but others do not use it
Oscillatory integrals on Hilbert spaces and Schroedinger equation with magnetic fields
International Nuclear Information System (INIS)
Albeverio, S.; Brzezniak, Z.
1994-01-01
We extend the theory of oscillatory integrals on Hilbert spaces (the mathematical version of ''Feynman path integrals'') to cover more general integrable functions, preserving the property of the integrals to have converging finite dimensional approximations. We give an application to the representation of solutions of the time dependent Schroedinger equation with a scalar and a magnetic potential by oscillatory integrals on Hilbert spaces. A relation with Ramer's functional in the corresponding probabilistic setting is found. (orig.)
Soft and hard classification by reproducing kernel Hilbert space methods.
Wahba, Grace
2002-12-24
Reproducing kernel Hilbert space (RKHS) methods provide a unified context for solving a wide variety of statistical modelling and function estimation problems. We consider two such problems: We are given a training set [yi, ti, i = 1, em leader, n], where yi is the response for the ith subject, and ti is a vector of attributes for this subject. The value of y(i) is a label that indicates which category it came from. For the first problem, we wish to build a model from the training set that assigns to each t in an attribute domain of interest an estimate of the probability pj(t) that a (future) subject with attribute vector t is in category j. The second problem is in some sense less ambitious; it is to build a model that assigns to each t a label, which classifies a future subject with that t into one of the categories or possibly "none of the above." The approach to the first of these two problems discussed here is a special case of what is known as penalized likelihood estimation. The approach to the second problem is known as the support vector machine. We also note some alternate but closely related approaches to the second problem. These approaches are all obtained as solutions to optimization problems in RKHS. Many other problems, in particular the solution of ill-posed inverse problems, can be obtained as solutions to optimization problems in RKHS and are mentioned in passing. We caution the reader that although a large literature exists in all of these topics, in this inaugural article we are selectively highlighting work of the author, former students, and other collaborators.
Alpay, Daniel
2015-01-01
This is an exercises book at the beginning graduate level, whose aim is to illustrate some of the connections between functional analysis and the theory of functions of one variable. A key role is played by the notions of positive definite kernel and of reproducing kernel Hilbert space. A number of facts from functional analysis and topological vector spaces are surveyed. Then, various Hilbert spaces of analytic functions are studied.
Some means inequalities for positive operators in Hilbert spaces
Directory of Open Access Journals (Sweden)
Jin Liang
2017-01-01
Full Text Available Abstract In this paper, we obtain two refinements of the ordering relations among Heinz means with different parameters via the Taylor series of some hyperbolic functions and by the way, we derive new generalizations of Heinz operator inequalities. Moreover, we establish a matrix version of Heinz inequality for the Hilbert-Schmidt norm. Finally, we introduce a weighted multivariate geometric mean and show that the weighted multivariate operator geometric mean possess several attractive properties and means inequalities.
Space Inside a Liquid Sphere Transforms into De Sitter Space by Hilbert Radius
Rabounski, Dmitri; Borissova, Larissa
2010-04-01
Consider space inside a sphere of incompressible liquid, and space surrounding a mass-point. Metrics of the spaces were deduced in 1916 by Karl Schwarzschild. 1) Our calculation shows that a liquid sphere can be in the state of gravitational collapse (g00 = 0) only if its mass and radius are close to those of the Universe (M = 8.7x10^55 g, a = 1.3x10^28 cm). However if the same mass is presented as a mass-point, the radius of collapse rg (Hilbert radius) is many orders lesser: g00 = 0 realizes in a mass-point's space by other conditions. 2) We considered a liquid sphere whose radius meets, formally, the Hilbert radius of a mass-point bearing the same mass: a = rg, however the liquid sphere is not a collapser (see above). We show that in this case the metric of the liquid sphere's internal space can be represented as de Sitter's space metric, wherein λ = 3/a^2 > 0: physical vacuum (due to the λ-term) is the same as the field of an ideal liquid where ρ0 0 (the mirror world liquid). The gravitational redshift inside the sphere is produced by the non-Newtonian force of repulsion (which is due to the λ-term, λ = 3/a^2 > 0); it is also calculated.
3D Hilbert Space Filling Curves in 3D City Modeling for Faster Spatial Queries
DEFF Research Database (Denmark)
Ujang, Uznir; Antón Castro, Francesc/François; Azri, Suhaibah
2014-01-01
The advantages of three dimensional (3D) city models can be seen in various applications including photogrammetry, urban and regional planning, computer games, etc. They expand the visualization and analysis capabilities of Geographic Information Systems on cities, and they can be developed using...... method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban...... objects. In this research, the authors propose an opponent data constellation technique of space-filling curves (3D Hilbert curves) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA...
Asymptotic behaviour of unbounded trajectories for some non-autonomous systems in a Hilbert space
International Nuclear Information System (INIS)
Djafari Rouhani, B.
1990-07-01
The asymptotic behaviour of unbounded trajectories for non expansive mappings in a real Hilbert space and the extension to more general Banach spaces and to nonlinear contraction semi-group have been studied by many authors. In this paper we study the asymptotic behaviour of unbounded trajectories for a quasi non-autonomous dissipative systems. 26 refs
Frames in super Hilbert modules
Directory of Open Access Journals (Sweden)
Mehdi Rashidi-Kouchi
2018-01-01
Full Text Available In this paper, we define super Hilbert module and investigate frames in this space. Super Hilbert modules are generalization of super Hilbert spaces in Hilbert C*-module setting. Also, we define frames in a super Hilbert module and characterize them by using of the concept of g-frames in a Hilbert C*-module. Finally, disjoint frames in Hilbert C*-modules are introduced and investigated.
A New General Iterative Method for a Finite Family of Nonexpansive Mappings in Hilbert Spaces
Directory of Open Access Journals (Sweden)
Singthong Urailuk
2010-01-01
Full Text Available We introduce a new general iterative method by using the -mapping for finding a common fixed point of a finite family of nonexpansive mappings in the framework of Hilbert spaces. A strong convergence theorem of the purposed iterative method is established under some certain control conditions. Our results improve and extend the results announced by many others.
Two New Iterative Methods for a Countable Family of Nonexpansive Mappings in Hilbert Spaces
Directory of Open Access Journals (Sweden)
Hu Changsong
2010-01-01
Full Text Available We consider two new iterative methods for a countable family of nonexpansive mappings in Hilbert spaces. We proved that the proposed algorithms strongly converge to a common fixed point of a countable family of nonexpansive mappings which solves the corresponding variational inequality. Our results improve and extend the corresponding ones announced by many others.
Hilbert space representation of the SOq(N)-covariant Heisenberg algebra
International Nuclear Information System (INIS)
Hebecker, A.; Weich, W.
1993-01-01
The differential calculus on SO q (N)-covariant quantum planes is rewritten in polar co-ordinates. Thus a Hilbert space formulation of q-deformed quantum mechanics can be developed particularly suitable for spherically symmetric potentials. The simplest case of a free particle is solved showing a discrete energy spectrum. (orig.)
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.
Projective loop quantum gravity. I. State space
Lanéry, Suzanne; Thiemann, Thomas
2016-12-01
Instead of formulating the state space of a quantum field theory over one big Hilbert space, it has been proposed by Kijowski to describe quantum states as projective families of density matrices over a collection of smaller, simpler Hilbert spaces. Beside the physical motivations for this approach, it could help designing a quantum state space holding the states we need. In a latter work by Okolów, the description of a theory of Abelian connections within this framework was developed, an important insight being to use building blocks labeled by combinations of edges and surfaces. The present work generalizes this construction to an arbitrary gauge group G (in particular, G is neither assumed to be Abelian nor compact). This involves refining the definition of the label set, as well as deriving explicit formulas to relate the Hilbert spaces attached to different labels. If the gauge group happens to be compact, we also have at our disposal the well-established Ashtekar-Lewandowski Hilbert space, which is defined as an inductive limit using building blocks labeled by edges only. We then show that the quantum state space presented here can be thought as a natural extension of the space of density matrices over this Hilbert space. In addition, it is manifest from the classical counterparts of both formalisms that the projective approach allows for a more balanced treatment of the holonomy and flux variables, so it might pave the way for the development of more satisfactory coherent states.
Tensor algebra over Hilbert space: Field theory in classical phase space
International Nuclear Information System (INIS)
Matos Neto, A.; Vianna, J.D.M.
1984-01-01
It is shown using tensor algebras, namely Symmetric and Grassmann algebras over Hilbert Space that it is possible to introduce field operators, associated to the Liouville equation of classical statistical mechanics, which are characterized by commutation (for Symmetric) and anticommutation (for Grassmann) rules. The procedure here presented shows by construction that many-particle classical systems admit an algebraic structure similar to that of quantum field theory. It is considered explicitly the case of n-particle systems interacting with an external potential. A new derivation of Schoenberg's result about the equivalence between his field theory in classical phase space and the usual classical statistical mechanics is obtained as a consequence of the algebraic structure of the theory as introduced by our method. (Author) [pt
Hilbert, Fock and Cantorian spaces in the quantum two-slit gedanken experiment
International Nuclear Information System (INIS)
El Naschie, M.S.
2006-01-01
On the one hand, a rigorous mathematical formulation of quantum mechanics requires the introduction of a Hilbert space and as we move to the second quantization, a Fock space. On the other hand, the Cantorian E-infinity approach to quantum physics was developed largely without any direct reference to the afore mentioned mathematical spaces. In the present work we utilize some novel reinterpretations of basic E (∞) Cantorian spacetime relations in terms of the Hilbert space of quantum mechanics. Proceeding in this way, we gain a better understanding of the physico-mathematical structure of quantum spacetime which is at the heart of the paradoxical and non-intuitive outcome of the famous quantum two-slit gedanken experiment
A simple proof to an extension of a theorem of A. Pazy in Hilbert space
International Nuclear Information System (INIS)
Djafari Rouhani, B.
1990-08-01
We prove that if (x n ) n≥0 is a non expansive sequence in a Hilbert space H, the sequence ( n x n ) n≥1 converges strongly in H to the element of minimum norm in the closed convex hull of the sequence (x n+1 -x n ) n≥0 . This result was previously proved; the proof we give here is even much simpler and can be extended to a Banach space. 29 refs
Estimates of solutions of certain classes of second-order differential equations in a Hilbert space
International Nuclear Information System (INIS)
Artamonov, N V
2003-01-01
Linear second-order differential equations of the form u''(t)+(B+iD)u'(t)+(T+iS)u(t)=0 in a Hilbert space are studied. Under certain conditions on the (generally speaking, unbounded) operators T, S, B and D the correct solubility of the equation in the 'energy' space is proved and best possible (in the general case) estimates of the solutions on the half-axis are obtained
Quantization of systems with temporally varying discretization. I. Evolving Hilbert spaces
International Nuclear Information System (INIS)
Höhn, Philipp A.
2014-01-01
A temporally varying discretization often features in discrete gravitational systems and appears in lattice field theory models subject to a coarse graining or refining dynamics. To better understand such discretization changing dynamics in the quantum theory, an according formalism for constrained variational discrete systems is constructed. While this paper focuses on global evolution moves and, for simplicity, restricts to flat configuration spaces R N , a Paper II [P. A. Höhn, “Quantization of systems with temporally varying discretization. II. Local evolution moves,” J. Math. Phys., e-print http://arxiv.org/abs/arXiv:1401.7731 [gr-qc].] discusses local evolution moves. In order to link the covariant and canonical picture, the dynamics of the quantum states is generated by propagators which satisfy the canonical constraints and are constructed using the action and group averaging projectors. This projector formalism offers a systematic method for tracing and regularizing divergences in the resulting state sums. Non-trivial coarse graining evolution moves lead to non-unitary, and thus irreversible, projections of physical Hilbert spaces and Dirac observables such that these concepts become evolution move dependent on temporally varying discretizations. The formalism is illustrated in a toy model mimicking a “creation from nothing.” Subtleties arising when applying such a formalism to quantum gravity models are discussed
Relativistic resonances as non-orthogonal states in Hilbert space
Blum, W
2003-01-01
We analyze the energy-momentum properties of relativistic short-lived particles with the result that they are characterized by two 4-vectors: in addition to the familiar energy-momentum vector (timelike) there is an energy-momentum 'spread vector' (spacelike). The wave functions in space and time for unstable particles are constructed. For the relativistic properties of unstable states we refer to Wigner's method of Poincare group representations that are induced by representations of the space-time translation and rotation groups. If stable particles, unstable particles and resonances are treated as elementary objects that are not fundamentally different one has to take into account that they will not generally be orthogonal to each other in their state space. The scalar product between a stable and an unstable state with otherwise identical properties is calculated in a particular Lorentz frame. The spin of an unstable particle is not infinitely sharp but has a 'spin spread' giving rise to 'spin neighbors'....
Alternative structures and bi-Hamiltonian systems on a Hilbert space
International Nuclear Information System (INIS)
Marmo, G; Scolarici, G; Simoni, A; Ventriglia, F
2005-01-01
We discuss transformations generated by dynamical quantum systems which are bi-unitary, i.e. unitary with respect to a pair of Hermitian structures on an infinite-dimensional complex Hilbert space. We introduce the notion of Hermitian structures in generic relative position. We provide a few necessary and sufficient conditions for two Hermitian structures to be in generic relative position to better illustrate the relevance of this notion. The group of bi-unitary transformations is considered in both the generic and the non-generic case. Finally, we generalize the analysis to real Hilbert spaces and extend to infinite dimensions results already available in the framework of finite-dimensional linear bi-Hamiltonian systems
Bulk entanglement gravity without a boundary: Towards finding Einstein's equation in Hilbert space
Cao, ChunJun; Carroll, Sean M.
2018-04-01
We consider the emergence from quantum entanglement of spacetime geometry in a bulk region. For certain classes of quantum states in an appropriately factorized Hilbert space, a spatial geometry can be defined by associating areas along codimension-one surfaces with the entanglement entropy between either side. We show how radon transforms can be used to convert these data into a spatial metric. Under a particular set of assumptions, the time evolution of such a state traces out a four-dimensional spacetime geometry, and we argue using a modified version of Jacobson's "entanglement equilibrium" that the geometry should obey Einstein's equation in the weak-field limit. We also discuss how entanglement equilibrium is related to a generalization of the Ryu-Takayanagi formula in more general settings, and how quantum error correction can help specify the emergence map between the full quantum-gravity Hilbert space and the semiclassical limit of quantum fields propagating on a classical spacetime.
Controlled G-Frames and Their G-Multipliers in Hilbert spaces
Rahimi, Asghar; Fereydooni, Abolhassan
2012-01-01
Multipliers have been recently introduced by P. Balazs as operators for Bessel sequences and frames in Hilbert spaces. These are operators that combine (frame-like) analysis, a multiplication with a fixed sequence (called the symbol) and synthesis. Weighted and controlled frames have been introduced to improve the numerical efficiency of iterative algorithms for inverting the frame operator Also g-frames are the most popular generalization of frames that include almost all of the frame extens...
Nonrelativistic multichannel quantum scattering theory in a two Hilbert space formulation
International Nuclear Information System (INIS)
Chandler, C.
1977-08-01
A two-Hilbert-space form of an abstract scattering theory specifically applicable to multichannel quantum scattering problems is outlined. General physical foundations of the theory are reviewed. Further topics discussed include the invariance principle, asymptotic completeness of the wave operators, representations of the scattering operator in terms of transition operators and fundamental equations that these transition operators satisfy. Outstanding problems, including the difficulties of including Coulomb interactions in the theory, are pointed out. (D.P.)
Approximately dual frames in Hilbert spaces and applications to Gabor frames
Christensen, Ole; Laugesen, Richard S.
2011-01-01
Approximately dual frames are studied in the Hilbert space setting. Approximate duals are easier to construct than classical dual frames, and can be tailored to yield almost perfect reconstruction. Bounds on the deviation from perfect reconstruction are obtained for approximately dual frames constructed via perturbation theory. An alternative bound is derived for the rich class of Gabor frames, by using the Walnut representation of the frame operator to estimate the deviation from equality in...
Limit distribution function of inhomogeneities in regions with random boundary in the Hilbert space
International Nuclear Information System (INIS)
Rasulova, M.Yu.; Tashpulatov, S.M.
2004-10-01
The interaction of charged particle systems with a membrane consisting of nonhomogeneities which are randomly distributed by the same law in the vicinity of appropriate sites of a planax crystal lattice is studied. A system of equations for the self-consistent potential U 1 (x,ξ 0 ,..., ξ N ,...) and the density of induced charges σ(x,ξ 0 ,...,ξ N ,...) is solved on Hilbert space. (author)
INFORMATIVE ENERGY METRIC FOR SIMILARITY MEASURE IN REPRODUCING KERNEL HILBERT SPACES
Directory of Open Access Journals (Sweden)
Songhua Liu
2012-02-01
Full Text Available In this paper, information energy metric (IEM is obtained by similarity computing for high-dimensional samples in a reproducing kernel Hilbert space (RKHS. Firstly, similar/dissimilar subsets and their corresponding informative energy functions are defined. Secondly, IEM is proposed for similarity measure of those subsets, which converts the non-metric distances into metric ones. Finally, applications of this metric is introduced, such as classification problems. Experimental results validate the effectiveness of the proposed method.
Quantum limits to information about states for finite dimensional Hilbert space
International Nuclear Information System (INIS)
Jones, K.R.W.
1990-01-01
A refined bound for the correlation information of an N-trial apparatus is developed via an heuristic argument for Hilbert spaces of arbitrary finite dimensionality. Conditional upon the proof of an easily motivated inequality it was possible to find the optimal apparatus for large ensemble quantum Inference, thereby solving the asymptotic optimal state determination problem. In this way an alternative inferential uncertainty principle, is defined which is then contrasted with the usual Heisenberg uncertainty principle. 6 refs
Covariant loops and strings in a positive definite Hilbert space
International Nuclear Information System (INIS)
Rohrlich, F.
1977-01-01
Relativistic loops and strings are defined in the conventional way as solutions of a one-dimensional wave equation with certain boundary conditions and satisfying the orthogonal gauge conditions. Conventional pseudo-Cartesian co-ordinates (rather than null-plane co-ordinates) are used. The creation and annihilation operator four-vector αsub(μ)sup(+) and αsub(m) are required to be spacelike (orthogonal to the total momentum Psup(μ), so that the resulting Fock space is positive definite. This requirements is shown to be mathematically consistent with Poincare' invariance and to impose no additional physical constraints on the system. It can be implemented in a canonical realization of the Poincare' algebra as a condition on a state vectors, or in a noncanonical realization as an operator equation, as is done here. The space is further restricted by the Virasoro conditions to a physical subspace PHI which is of course also positive definite. In this way there arises no critical-dimension problem and Poincare' invariance holds also in 3+1 dimensions. The energy and spin spectra are the same as usual, leading to linear Regge trajectories, except that there are no tachyons and no zero mass states. The leading Regge trajectory has negative intercept
Effective realistic interactions for low momentum Hilbert spaces
International Nuclear Information System (INIS)
Weber, Dennis
2012-01-01
Realistic nucleon-nucleon potentials are an essential ingredient of modern microscopic many-body calculations. These potentials can be represented in two different ways: operator representation or matrix element representation. In operator representation the potential is represented by a set of quantum mechanical operators while in matrix element representation it is defined by the matrix elements in a given basis. Many modern potentials are constructed directly in matrix element representation. While the matrix element representation can be calculated from the operator representation, the determination of the operator representation from the matrix elements is more difficult. Some methods to solve the nuclear many-body problem, such as Fermionic Molecular Dynamics (FMD) or the Green's Function Monte Carlo (GFMC) method, however require explicitly the operator representation of the potential, as they do not work in a fixed many-body basis. It is therefore desirable to derive an operator representation also for the interactions given by matrix elements. In this work a method is presented which allows the derivation of an approximate operator representation starting from the momentum space partial wave matrix elements of the interaction. For that purpose an ansatz for the operator representation is chosen. The parameters in the ansatz are determined by a fit to the partial wave matrix elements. Since a perfect reproduction of the matrix elements in general cannot be achieved with a finite number of operators and the quality of the results depends on the choice of the ansatz, the obtained operator representation is tested in nuclear many-body calculations and the results are compared with those from the initial interaction matrix elements. For the calculation of the nucleon-nucleon scattering phase shifts and the deuteron properties a computer code written within this work is used. For larger nuclei the No Core Shell Model (NCSM) and FMD are applied. The described
Quantum computation via local control theory: Direct sum vs. direct product Hilbert spaces
International Nuclear Information System (INIS)
Sklarz, Shlomo E.; Tannor, David J.
2006-01-01
The central objective in any quantum computation is the creation of a desired unitary transformation; the mapping that this unitary transformation produces between the input and output states is identified with the computation. In [S.E. Sklarz, D.J. Tannor, arXiv:quant-ph/0404081 (submitted to PRA) (2004)] it was shown that local control theory can be used to calculate fields that will produce such a desired unitary transformation. In contrast with previous strategies for quantum computing based on optimal control theory, the local control scheme maintains the system within the computational subspace at intermediate times, thereby avoiding unwanted decay processes. In [S.E. Sklarz et al.], the structure of the Hilbert space had a direct sum structure with respect to the computational register and the mediating states. In this paper, we extend the formalism to the important case of a direct product Hilbert space. The final equations for the control algorithm for the two cases are remarkably similar in structure, despite the fact that the derivations are completely different and that in one case the dynamics is in a Hilbert space and in the other case the dynamics is in a Liouville space. As shown in [S.E. Sklarz et al.], the direct sum implementation leads to a computational mechanism based on virtual transitions, and can be viewed as an extension of the principles of Stimulated Raman Adiabatic Passage from state manipulation to evolution operator manipulation. The direct product implementation developed here leads to the intriguing concept of virtual entanglement - computation that exploits second-order transitions that pass through entangled states but that leaves the subsystems nearly separable at all intermediate times. Finally, we speculate on a connection between the algorithm developed here and the concept of decoherence free subspaces
Method of the Determination of Exterior Orientation of Sensors in Hilbert Type Space.
Stępień, Grzegorz
2018-03-17
The following article presents a new isometric transformation algorithm based on the transformation in the newly normed Hilbert type space. The presented method is based on so-called virtual translations, already known in advance, of two relative oblique orthogonal coordinate systems-interior and exterior orientation of sensors-to a common, known in both systems, point. Each of the systems is translated along its axis (the systems have common origins) and at the same time the angular relative orientation of both coordinate systems is constant. The translation of both coordinate systems is defined by the spatial norm determining the length of vectors in the new Hilbert type space. As such, the displacement of two relative oblique orthogonal systems is reduced to zero. This makes it possible to directly calculate the rotation matrix of the sensor. The next and final step is the return translation of the system along an already known track. The method can be used for big rotation angles. The method was verified in laboratory conditions for the test data set and measurement data (field data). The accuracy of the results in the laboratory test is on the level of 10 -6 of the input data. This confirmed the correctness of the assumed calculation method. The method is a further development of the author's 2017 Total Free Station (TFS) transformation to several centroids in Hilbert type space. This is the reason why the method is called Multi-Centroid Isometric Transformation-MCIT. MCIT is very fast and enables, by reducing to zero the translation of two relative oblique orthogonal coordinate systems, direct calculation of the exterior orientation of the sensors.
Method of the Determination of Exterior Orientation of Sensors in Hilbert Type Space
Directory of Open Access Journals (Sweden)
Grzegorz Stępień
2018-03-01
Full Text Available The following article presents a new isometric transformation algorithm based on the transformation in the newly normed Hilbert type space. The presented method is based on so-called virtual translations, already known in advance, of two relative oblique orthogonal coordinate systems—interior and exterior orientation of sensors—to a common, known in both systems, point. Each of the systems is translated along its axis (the systems have common origins and at the same time the angular relative orientation of both coordinate systems is constant. The translation of both coordinate systems is defined by the spatial norm determining the length of vectors in the new Hilbert type space. As such, the displacement of two relative oblique orthogonal systems is reduced to zero. This makes it possible to directly calculate the rotation matrix of the sensor. The next and final step is the return translation of the system along an already known track. The method can be used for big rotation angles. The method was verified in laboratory conditions for the test data set and measurement data (field data. The accuracy of the results in the laboratory test is on the level of 10−6 of the input data. This confirmed the correctness of the assumed calculation method. The method is a further development of the author’s 2017 Total Free Station (TFS transformation to several centroids in Hilbert type space. This is the reason why the method is called Multi-Centroid Isometric Transformation—MCIT. MCIT is very fast and enables, by reducing to zero the translation of two relative oblique orthogonal coordinate systems, direct calculation of the exterior orientation of the sensors.
Construction of rigged Hilbert spaces to describe resonances and virtual states
International Nuclear Information System (INIS)
Gadella, M.
1983-01-01
In the present communication we present a mathematical formalism for the description of resonances and virtual states. We start by constructing rigged Hilbert spaces of Hardy class functions restricted to the positive half of the real line. Then resonances and virtual states can be written as generalized eigenvectors of the total Hamiltonian. We also define time evolution on functionals. We see that the time evolution group U(t) splits into two semigroups, one for t > 0 and the other for t < 0, hence showing the irreversibility of the decaying process
Classical and quantum contents of solvable game theory on Hilbert space
International Nuclear Information System (INIS)
Cheon, Taksu; Tsutsui, Izumi
2006-01-01
A simple and general formulation of the quantum game theory is presented, accommodating all possible strategies in the Hilbert space for the first time. The theory is solvable for the two strategy quantum game, which is shown to be equivalent to a family of classical games supplemented by quantum interference. Our formulation gives a clear perspective to understand why and how quantum strategies outmaneuver classical strategies. It also reveals novel aspects of quantum games such as the stone-scissor-paper phase sub-game and the fluctuation-induced moderation
Strong Convergence of Hybrid Algorithm for Asymptotically Nonexpansive Mappings in Hilbert Spaces
Directory of Open Access Journals (Sweden)
Juguo Su
2012-01-01
Full Text Available The hybrid algorithms for constructing fixed points of nonlinear mappings have been studied extensively in recent years. The advantage of this methods is that one can prove strong convergence theorems while the traditional iteration methods just have weak convergence. In this paper, we propose two types of hybrid algorithm to find a common fixed point of a finite family of asymptotically nonexpansive mappings in Hilbert spaces. One is cyclic Mann's iteration scheme, and the other is cyclic Halpern's iteration scheme. We prove the strong convergence theorems for both iteration schemes.
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.
Construction of rigged Hilbert spaces to describe resonances and virtual states
International Nuclear Information System (INIS)
Gadella, M.
1984-01-01
In the present communication we present a mathematical formalism for the description of resonances and virtual states. We start by constructing rigged Hilbert spaces of Hardy class functions restricted to the positive half of the real line. Then resonances and virtual states can be written as generalized eigenvectors of the total Hamiltonian. We also define time evolution on functionals. We see that the time evolution group U(t) splits into two semigroups, one for t>0 and the other for t<0, hence showing the irreversibility of the decaying process. (orig.)
On knottings in the physical Hilbert space of LQG as given by the EPRL model
International Nuclear Information System (INIS)
Bahr, Benjamin
2011-01-01
We consider the EPRL spin foam amplitude for arbitrary embedded two-complexes. Choosing a definition of the face- and edge amplitudes which lead to spin foam amplitudes invariant under trivial subdivisions, we investigate invariance properties of the amplitude under consistent deformations, which are deformations of the embedded two-complex where faces are allowed to pass through each other in a controlled way. Using this surprising invariance, we are able to show that the physical Hilbert space, as defined by the sum over all spin foams, contains no information about knotting classes of graphs anymore.
Recipes for stable linear embeddings from Hilbert spaces to R^m
Puy, Gilles; Davies, Michael; Gribonval, Remi
2017-01-01
We consider the problem of constructing a linear map from a Hilbert space H (possibly infinite dimensional) to Rm that satisfies a restricted isometry property (RIP) on an arbitrary signal model, i.e., a subset of H. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP with high probability. We also describe a generic technique ...
Recipes for stable linear embeddings from Hilbert spaces to R^m
Puy, Gilles; Davies, Mike; Gribonval, Rémi
2015-01-01
We consider the problem of constructing a linear map from a Hilbert space $\\mathcal{H}$ (possibly infinite dimensional) to $\\mathbb{R}^m$ that satisfies a restricted isometry property (RIP) on an arbitrary signal model $\\mathcal{S} \\subset \\mathcal{H}$. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP on $\\mathcal{S}$ with h...
An Hilbert space approach for a class of arbitrage free implied volatilities models
Brace, A.; Fabbri, G.; Goldys, B.
2007-01-01
We present an Hilbert space formulation for a set of implied volatility models introduced in \\cite{BraceGoldys01} in which the authors studied conditions for a family of European call options, varying the maturing time and the strike price $T$ an $K$, to be arbitrage free. The arbitrage free conditions give a system of stochastic PDEs for the evolution of the implied volatility surface ${\\hat\\sigma}_t(T,K)$. We will focus on the family obtained fixing a strike $K$ and varying $T$. In order to...
The physical boundary Hilbert space and volume operator in the Lorentzian new spin-foam theory
International Nuclear Information System (INIS)
Ding You; Rovelli, Carlo
2010-01-01
A covariant spin-foam formulation of quantum gravity has been recently developed, characterized by a kinematics which appears to match well the one of canonical loop quantum gravity. In this paper we reconsider the implementation of the constraints that defines the model. We define in a simple way the boundary Hilbert space of the theory, introducing a slight modification of the embedding of the SU(2) representations into the SL(2,C) ones. We then show directly that all constraints vanish on this space in a weak sense. The vanishing is exact (and not just in the large quantum number limit). We also generalize the definition of the volume operator in the spin-foam model to the Lorentzian signature and show that it matches the one of loop quantum gravity, as in the Euclidean case.
The Schrödinger–Robinson inequality from stochastic analysis on a complex Hilbert space
International Nuclear Information System (INIS)
Khrennikov, Andrei
2013-01-01
We explored the stochastic analysis on a complex Hilbert space to show that one of the cornerstones of quantum mechanics (QM), namely Heisenberg's uncertainty relation, can be derived in the classical probabilistic framework. We created a new mathematical representation of quantum averages: as averages with respect to classical random fields. The existence of a classical stochastic model matching with Heisenberg's uncertainty relation makes the connection between classical and quantum probabilistic models essentially closer. In real physical situations, random fields are valued in the L 2 -space. Hence, although we model QM and not QFT, the classical systems under consideration have an infinite number of degrees of freedom. And in our modeling, infinite-dimensional stochastic analysis is the basic mathematical tool. (comment)
Fano, Guido
2017-01-01
This book is designed to make accessible to nonspecialists the still evolving concepts of quantum mechanics and the terminology in which these are expressed. The opening chapters summarize elementary concepts of twentieth century quantum mechanics and describe the mathematical methods employed in the field, with clear explanation of, for example, Hilbert space, complex variables, complex vector spaces and Dirac notation, and the Heisenberg uncertainty principle. After detailed discussion of the Schrödinger equation, subsequent chapters focus on isotropic vectors, used to construct spinors, and on conceptual problems associated with measurement, superposition, and decoherence in quantum systems. Here, due attention is paid to Bell’s inequality and the possible existence of hidden variables. Finally, progression toward quantum computation is examined in detail: if quantum computers can be made practicable, enormous enhancements in computing power, artificial intelligence, and secure communication will result...
Parallel magnetic resonance imaging as approximation in a reproducing kernel Hilbert space
International Nuclear Information System (INIS)
Athalye, Vivek; Lustig, Michael; Martin Uecker
2015-01-01
In magnetic resonance imaging data samples are collected in the spatial frequency domain (k-space), typically by time-consuming line-by-line scanning on a Cartesian grid. Scans can be accelerated by simultaneous acquisition of data using multiple receivers (parallel imaging), and by using more efficient non-Cartesian sampling schemes. To understand and design k-space sampling patterns, a theoretical framework is needed to analyze how well arbitrary sampling patterns reconstruct unsampled k-space using receive coil information. As shown here, reconstruction from samples at arbitrary locations can be understood as approximation of vector-valued functions from the acquired samples and formulated using a reproducing kernel Hilbert space with a matrix-valued kernel defined by the spatial sensitivities of the receive coils. This establishes a formal connection between approximation theory and parallel imaging. Theoretical tools from approximation theory can then be used to understand reconstruction in k-space and to extend the analysis of the effects of samples selection beyond the traditional image-domain g-factor noise analysis to both noise amplification and approximation errors in k-space. This is demonstrated with numerical examples. (paper)
Ito, Kazufumi
1987-01-01
The linear quadratic optimal control problem on infinite time interval for linear time-invariant systems defined on Hilbert spaces is considered. The optimal control is given by a feedback form in terms of solution pi to the associated algebraic Riccati equation (ARE). A Ritz type approximation is used to obtain a sequence pi sup N of finite dimensional approximations of the solution to ARE. A sufficient condition that shows pi sup N converges strongly to pi is obtained. Under this condition, a formula is derived which can be used to obtain a rate of convergence of pi sup N to pi. The results of the Galerkin approximation is demonstrated and applied for parabolic systems and the averaging approximation for hereditary differential systems.
Regularization in Hilbert space under unbounded operators and general source conditions
International Nuclear Information System (INIS)
Hofmann, Bernd; Mathé, Peter; Von Weizsäcker, Heinrich
2009-01-01
The authors study ill-posed equations with unbounded operators in Hilbert space. This setup has important applications, but only a few theoretical studies are available. First, the question is addressed and answered whether every element satisfies some general source condition with respect to a given self-adjoint unbounded operator. This generalizes a previous result from Mathé and Hofmann (2008 Inverse Problems 24 015009). The analysis then proceeds to error bounds for regularization, emphasizing some specific points for regularization under unbounded operators. The study finally reviews two examples within the light of the present study, as these are fractional differentiation and some Cauchy problems for the Helmholtz equation, both studied previously and in more detail by U Tautenhahn and co-authors
Systems of general nonlinear set-valued mixed variational inequalities problems in Hilbert spaces
Directory of Open Access Journals (Sweden)
Cho Yeol
2011-01-01
Full Text Available Abstract In this paper, the existing theorems and methods for finding solutions of systems of general nonlinear set-valued mixed variational inequalities problems in Hilbert spaces are studied. To overcome the difficulties, due to the presence of a proper convex lower semi-continuous function, φ and a mapping g, which appeared in the considered problem, we have used some applications of the resolvent operator technique. We would like to point out that although many authors have proved results for finding solutions of the systems of nonlinear set-valued (mixed variational inequalities problems, it is clear that it cannot be directly applied to the problems that we have considered in this paper because of φ and g. 2000 AMS Subject Classification: 47H05; 47H09; 47J25; 65J15.
A Numerical Approximation Framework for the Stochastic Linear Quadratic Regulator on Hilbert Spaces
Energy Technology Data Exchange (ETDEWEB)
Levajković, Tijana, E-mail: tijana.levajkovic@uibk.ac.at, E-mail: t.levajkovic@sf.bg.ac.rs; Mena, Hermann, E-mail: hermann.mena@uibk.ac.at [University of Innsbruck, Department of Mathematics (Austria); Tuffaha, Amjad, E-mail: atufaha@aus.edu [American University of Sharjah, Department of Mathematics (United Arab Emirates)
2017-06-15
We present an approximation framework for computing the solution of the stochastic linear quadratic control problem on Hilbert spaces. We focus on the finite horizon case and the related differential Riccati equations (DREs). Our approximation framework is concerned with the so-called “singular estimate control systems” (Lasiecka in Optimal control problems and Riccati equations for systems with unbounded controls and partially analytic generators: applications to boundary and point control problems, 2004) which model certain coupled systems of parabolic/hyperbolic mixed partial differential equations with boundary or point control. We prove that the solutions of the approximate finite-dimensional DREs converge to the solution of the infinite-dimensional DRE. In addition, we prove that the optimal state and control of the approximate finite-dimensional problem converge to the optimal state and control of the corresponding infinite-dimensional problem.
Blanchard, Philippe
2015-01-01
The second edition of this textbook presents the basic mathematical knowledge and skills that are needed for courses on modern theoretical physics, such as those on quantum mechanics, classical and quantum field theory, and related areas. The authors stress that learning mathematical physics is not a passive process and include numerous detailed proofs, examples, and over 200 exercises, as well as hints linking mathematical concepts and results to the relevant physical concepts and theories. All of the material from the first edition has been updated, and five new chapters have been added on such topics as distributions, Hilbert space operators, and variational methods. The text is divided into three main parts. Part I is a brief introduction to distribution theory, in which elements from the theories of ultradistributions and hyperfunctions are considered in addition to some deeper results for Schwartz distributions, thus providing a comprehensive introduction to the theory of generalized functions. P...
International Nuclear Information System (INIS)
Gessner, W.; Ernst, V.
1980-01-01
The indefinite metric space O/sub M/ of the covariant form of the quantized Maxwell field M is analyzed in some detail. S/sub M/ contains not only the pre-Hilbert space X 0 of states of transverse photons which occurs in the Gupta--Bleuler formalism of the free M, but a whole rosette of continuously many, isomorphic, complete, pre-Hilbert spaces L/sup q/ disjunct up to the zero element o of S/sub M/. The L/sup q/ are the maximal subspaces of S/sub M/ which allow the usual statistical interpretation. Each L/sup q/ corresponds uniquely to one square integrable, spatial distribution j/sup o/(x) of the total charge Q=0. If M is in any state from L/sup q/, the bare charge j 0 (x) appears to be inseparably dressed by the quantum equivalent of its proper, classical Coulomb field E(x). The vacuum occurs only in the state space L 0 of the free Maxwell field. Each L/sup q/ contains a secondary rosette of continuously many, up to o disjunct, isomorphic Hilbert spaces H/sub g//sup q/ related to different electromagnetic gauges. The space H/sub o//sup q/, which corresponds to the Coulomb gauge within the Lorentz gauge, plays a physically distinguished role in that only it leads to the usual concept of energy. If M is in any state from H/sub g//sup q/, the bare 4-current j 0 (x), j(x), where j(x) is any square integrable, transverse current density in space, is endowed with its proper 4-potential which depends on the chosen gauge, and with its proper, gauge independent, Coulomb--Oersted field E(x), B(x). However, these fields exist only in the sense of quantum mechanical expectation values equipped with the corresponding field fluctuations. So they are basically different from classical electromagnetic fields
A differential equation for Lerch's transcendent and associated symmetric operators in Hilbert space
International Nuclear Information System (INIS)
Kaplitskii, V M
2014-01-01
The function Ψ(x,y,s)=e iy Φ(−e iy ,s,x), where Φ(z,s,v) is Lerch's transcendent, satisfies the following two-dimensional formally self-adjoint second-order hyperbolic differential equation, where s=1/2+iλ. The corresponding differential expression determines a densely defined symmetric operator (the minimal operator) on the Hilbert space L 2 (Π), where Π=(0,1)×(0,2π). We obtain a description of the domains of definition of some symmetric extensions of the minimal operator. We show that formal solutions of the eigenvalue problem for these symmetric extensions are represented by functional series whose structure resembles that of the Fourier series of Ψ(x,y,s). We discuss sufficient conditions for these formal solutions to be eigenfunctions of the resulting symmetric differential operators. We also demonstrate a close relationship between the spectral properties of these symmetric differential operators and the distribution of the zeros of some special analytic functions analogous to the Riemann zeta function. Bibliography: 15 titles
International Nuclear Information System (INIS)
Bach, A.
1981-01-01
A representation of quantum mechanics in terms of classical probability theory by means of integration in Hilbert space is discussed. This formal hidden-variables representation is analysed in the context of impossibility proofs concerning hidden-variables theories. The structural analogy of this formulation of quantum theory with classical statistical mechanics is used to elucidate the difference between classical mechanics and quantum mechanics. (author)
Directory of Open Access Journals (Sweden)
Zhou Yinying
2014-01-01
Full Text Available We introduce a hybrid iterative scheme for finding a common element of the set of common fixed points for a family of infinitely nonexpansive mappings, the set of solutions of the varitional inequality problem and the equilibrium problem in Hilbert space. Under suitable conditions, some strong convergence theorems are obtained. Our results improve and extend the corresponding results in (Chang et al. (2009, Min and Chang (2012, Plubtieng and Punpaeng (2007, S. Takahashi and W. Takahashi (2007, Tada and Takahashi (2007, Gang and Changsong (2009, Ying (2013, Y. Yao and J. C. Yao (2007, and Yong-Cho and Kang (2012.
International Nuclear Information System (INIS)
Gallego-Castillo, Cristobal; Bessa, Ricardo; Cavalcante, Laura; Lopez-Garcia, Oscar
2016-01-01
Wind power probabilistic forecast is being used as input in several decision-making problems, such as stochastic unit commitment, operating reserve setting and electricity market bidding. This work introduces a new on-line quantile regression model based on the Reproducing Kernel Hilbert Space (RKHS) framework. Its application to the field of wind power forecasting involves a discussion on the choice of the bias term of the quantile models, and the consideration of the operational framework in order to mimic real conditions. Benchmark against linear and splines quantile regression models was performed for a real case study during a 18 months period. Model parameter selection was based on k-fold crossvalidation. Results showed a noticeable improvement in terms of calibration, a key criterion for the wind power industry. Modest improvements in terms of Continuous Ranked Probability Score (CRPS) were also observed for prediction horizons between 6 and 20 h ahead. - Highlights: • New online quantile regression model based on the Reproducing Kernel Hilbert Space. • First application to operational probabilistic wind power forecasting. • Modest improvements of CRPS for prediction horizons between 6 and 20 h ahead. • Noticeable improvements in terms of Calibration due to online learning.
International Nuclear Information System (INIS)
Arik, M.
1991-01-01
It is shown that the differential calculus of Wess and Zumino for the quantum hyperplane is intimately related to the q-difference operator acting on the n-dimensional complex space C n . An explicit transformation relates the variables and the q-difference operators on C n to the variables and the quantum derivatives on the quantum hyperplane. For real values of the quantum parameter q, the consideration of the variables and the derivatives as hermitean conjugates yields a quantum deformation of the Bargmann-Segal Hilbert space of analytic functions on C n . Physically such a system can be interpreted as the quantum deformation of the n dimensional harmonic oscillator invariant under the unitary quantum group U q (n) with energy eigenvalues proportional to the basic integers. Finally, a construction of the variables and quantum derivatives on the quantum hyperplane in terms of variables and ordinary derivatives on C n is presented. (orig.)
Yuji, NAKAWAKI; Azuma, TANAKA; Kazuhiko, OZAKI; Division of Physics and Mathematics, Faculty of Engineering Setsunan University; Junior College of Osaka Institute of Technology; Faculty of General Education, Osaka Institute of Technology
1994-01-01
Gauge Equivalence of the A_3=0 (axial) gauge to the Coulomb gauge is directly verified in QED. For that purpose a pair of conjugate zero-norm fields are introduced. This enables us to construct a canonical formulation in the axial gauge embedded in the indefinite metric Hilbert space in such a way that the Feynman rules are not altered. In the indefinite metric Hilbert space we can implement a gauge transformation, which otherwise has to be carried out only by hand, as main parts of a canonic...
Directory of Open Access Journals (Sweden)
Kan Li
2018-04-01
Full Text Available This paper presents a novel real-time dynamic framework for quantifying time-series structure in spoken words using spikes. Audio signals are converted into multi-channel spike trains using a biologically-inspired leaky integrate-and-fire (LIF spike generator. These spike trains are mapped into a function space of infinite dimension, i.e., a Reproducing Kernel Hilbert Space (RKHS using point-process kernels, where a state-space model learns the dynamics of the multidimensional spike input using gradient descent learning. This kernelized recurrent system is very parsimonious and achieves the necessary memory depth via feedback of its internal states when trained discriminatively, utilizing the full context of the phoneme sequence. A main advantage of modeling nonlinear dynamics using state-space trajectories in the RKHS is that it imposes no restriction on the relationship between the exogenous input and its internal state. We are free to choose the input representation with an appropriate kernel, and changing the kernel does not impact the system nor the learning algorithm. Moreover, we show that this novel framework can outperform both traditional hidden Markov model (HMM speech processing as well as neuromorphic implementations based on spiking neural network (SNN, yielding accurate and ultra-low power word spotters. As a proof of concept, we demonstrate its capabilities using the benchmark TI-46 digit corpus for isolated-word automatic speech recognition (ASR or keyword spotting. Compared to HMM using Mel-frequency cepstral coefficient (MFCC front-end without time-derivatives, our MFCC-KAARMA offered improved performance. For spike-train front-end, spike-KAARMA also outperformed state-of-the-art SNN solutions. Furthermore, compared to MFCCs, spike trains provided enhanced noise robustness in certain low signal-to-noise ratio (SNR regime.
Li, Kan; Príncipe, José C
2018-01-01
This paper presents a novel real-time dynamic framework for quantifying time-series structure in spoken words using spikes. Audio signals are converted into multi-channel spike trains using a biologically-inspired leaky integrate-and-fire (LIF) spike generator. These spike trains are mapped into a function space of infinite dimension, i.e., a Reproducing Kernel Hilbert Space (RKHS) using point-process kernels, where a state-space model learns the dynamics of the multidimensional spike input using gradient descent learning. This kernelized recurrent system is very parsimonious and achieves the necessary memory depth via feedback of its internal states when trained discriminatively, utilizing the full context of the phoneme sequence. A main advantage of modeling nonlinear dynamics using state-space trajectories in the RKHS is that it imposes no restriction on the relationship between the exogenous input and its internal state. We are free to choose the input representation with an appropriate kernel, and changing the kernel does not impact the system nor the learning algorithm. Moreover, we show that this novel framework can outperform both traditional hidden Markov model (HMM) speech processing as well as neuromorphic implementations based on spiking neural network (SNN), yielding accurate and ultra-low power word spotters. As a proof of concept, we demonstrate its capabilities using the benchmark TI-46 digit corpus for isolated-word automatic speech recognition (ASR) or keyword spotting. Compared to HMM using Mel-frequency cepstral coefficient (MFCC) front-end without time-derivatives, our MFCC-KAARMA offered improved performance. For spike-train front-end, spike-KAARMA also outperformed state-of-the-art SNN solutions. Furthermore, compared to MFCCs, spike trains provided enhanced noise robustness in certain low signal-to-noise ratio (SNR) regime.
Quantum correlations and dynamics from classical random fields valued in complex Hilbert spaces
International Nuclear Information System (INIS)
Khrennikov, Andrei
2010-01-01
One of the crucial differences between mathematical models of classical and quantum mechanics (QM) is the use of the tensor product of the state spaces of subsystems as the state space of the corresponding composite system. (To describe an ensemble of classical composite systems, one uses random variables taking values in the Cartesian product of the state spaces of subsystems.) We show that, nevertheless, it is possible to establish a natural correspondence between the classical and the quantum probabilistic descriptions of composite systems. Quantum averages for composite systems (including entangled) can be represented as averages with respect to classical random fields. It is essentially what Albert Einstein dreamed of. QM is represented as classical statistical mechanics with infinite-dimensional phase space. While the mathematical construction is completely rigorous, its physical interpretation is a complicated problem. We present the basic physical interpretation of prequantum classical statistical field theory in Sec. II. However, this is only the first step toward real physical theory.
Coherent states on Hilbert modules
International Nuclear Information System (INIS)
Ali, S Twareque; Bhattacharyya, T; Roy, S S
2011-01-01
We generalize the concept of coherent states, traditionally defined as special families of vectors on Hilbert spaces, to Hilbert modules. We show that Hilbert modules over C*-algebras are the natural settings for a generalization of coherent states defined on Hilbert spaces. We consider those Hilbert C*-modules which have a natural left action from another C*-algebra, say A. The coherent states are well defined in this case and they behave well with respect to the left action by A. Certain classical objects like the Cuntz algebra are related to specific examples of coherent states. Finally we show that coherent states on modules give rise to a completely positive definite kernel between two C*-algebras, in complete analogy to the Hilbert space situation. Related to this, there is a dilation result for positive operator-valued measures, in the sense of Naimark. A number of examples are worked out to illustrate the theory. Some possible physical applications are also mentioned.
International Nuclear Information System (INIS)
Hermann, M.R.; Langhoff, P.W.
1983-01-01
Explicit Hilbert-space techniques are reported for construction of the discrete and continuum Schroedinger states required in atomic and molecular photoexcitation and/or photoionization studies. These developments extend and clarify previously described moment-theory methods for determinations of photoabsorption cross sections from discrete basis-set calculations to include explicit construction of underlying wave functions. The appropriate Stieltjes-Tchebycheff excitation and ionization functions of nth order are defined as Radau-type eigenstates of an appropriate operator in an n-term Cauchy-Lanczos basis. The energies of these states are the Radau quadrature points of the photoabsorption cross section, and their (reciprocal) norms provide the corresponding quadrature weights. Although finite-order Stieltjes-Tchebycheff functions are L 2 integrable, and do not have asymptotic spatial tails in the continuous spectrum, the Radau quadrature weights nevertheless provide information for normalization in the conventional Dirac delta-function sense. Since one Radau point can be placed anywhere in the spectrum, appropriately normalized convergent approximations to any of the discrete or continuum Schroedinger states are obtained from the development. Connections with matrix partitioning methods are established, demonstrating that nth-order Stieltjes-Tchebycheff functions are optical-potential solutions of the matrix Schroedinger equation in the full Cauchy-Lanczos basis
Potoček, Václav; Miatto, Filippo M; Mirhosseini, Mohammad; Magaña-Loaiza, Omar S; Liapis, Andreas C; Oi, Daniel K L; Boyd, Robert W; Jeffers, John
2015-10-16
In 1924 David Hilbert conceived a paradoxical tale involving a hotel with an infinite number of rooms to illustrate some aspects of the mathematical notion of "infinity." In continuous-variable quantum mechanics we routinely make use of infinite state spaces: here we show that such a theoretical apparatus can accommodate an analog of Hilbert's hotel paradox. We devise a protocol that, mimicking what happens to the guests of the hotel, maps the amplitudes of an infinite eigenbasis to twice their original quantum number in a coherent and deterministic manner, producing infinitely many unoccupied levels in the process. We demonstrate the feasibility of the protocol by experimentally realizing it on the orbital angular momentum of a paraxial field. This new non-Gaussian operation may be exploited, for example, for enhancing the sensitivity of NOON states, for increasing the capacity of a channel, or for multiplexing multiple channels into a single one.
International Nuclear Information System (INIS)
Schroer, Bert; FU-Berlin
2012-02-01
Massive quantum matter of prescribed spin permits infinitely many possibilities of covariantization in terms of spinorial (undotted/dotted) pointlike fields, whereas massless nite helicity representations lead to large gap in this spinorial spectrum which for s=1 excludes vector potentials. Since the nonexistence of such pointlike generators is the result of a deep structural clash between modular localization and the Hilbert space setting of QT, there are two ways out: gauge theory which sacrifices the Hilbert space and keeps the pointlike formalism and the use of string like potentials which allows to preserve the Hilbert space. The latter setting contains also string-localized charge-carrying operators whereas the gauge theoretic formulation is limited to point-like generated observables. This description also gives a much better insight into the Higgs mechanism which leads to a revival of the more physical 'Schwinger-Higgs' screening idea. The new formalism is not limited to m=0, s=1, it leads to renormalizable inter- actions in the sense of power-counting for all s in massless representations. The existence of string like vector potentials is preempted by the Aharonov-Bohm effect in QFT; it is well-known that the use of pointlike vector potentials in Stokes theorem would with lead to wrong results. Their use in Maxwell's equations is known to lead to zero Maxwell charge. The role of string-localization in the problem behind the observed invisibility and confinement of gluons and quarks leads to new questions and problems. (author)
Variational Inequalities in Hilbert Spaces with Measures and Optimal Stopping Problems
International Nuclear Information System (INIS)
Barbu, Viorel; Marinelli, Carlo
2008-01-01
We study the existence theory for parabolic variational inequalities in weighted L 2 spaces with respect to excessive measures associated with a transition semigroup. We characterize the value function of optimal stopping problems for finite and infinite dimensional diffusions as a generalized solution of such a variational inequality. The weighted L 2 setting allows us to cover some singular cases, such as optimal stopping for stochastic equations with degenerate diffusion coefficient. As an application of the theory, we consider the pricing of American-style contingent claims. Among others, we treat the cases of assets with stochastic volatility and with path-dependent payoffs
Truncated Hilbert Space Approach for the 1+1D phi^4 Theory
CERN. Geneva
2016-01-01
(an informal seminar, not a regular string seminar) We used the massive analogue of the truncated conformal space approach to study the broken phase of the 1+1 dimensional scalar phi^4 model in finite volume, similarly to the work by S. Rychkov and L. Vitale. In our work, the finite size spectrum was determined numerically using an effective eigensolver routine, which was followed by a simple extrapolation in the cutoff energy. We analyzed both the periodic and antiperiodic sectors. The results were compared with semiclassical and Bethe-Yang results as well as perturbation theory. We obtained the coupling dependence of the infinite volume breather and kink masses for moderate couplings. The results fit well with semiclassics and perturbative estimations, and confirm the conjecture of Mussardo that at most two neutral excitations can exist in the spectrum. We believe that improving our method with the renormalization procedure of Rychkov et al. enables to measure further interesting quantities such as decay ra...
N-body quantum scattering theory in two Hilbert spaces. VII. Real-energy limits
International Nuclear Information System (INIS)
Chandler, C.; Gibson, A.G.
1994-01-01
A study is made of the real-energy limits of approximate solutions of the Chandler--Gibson equations, as well as the real-energy limits of the approximate equations themselves. It is proved that (1) the approximate time-independent transition operator T π (z) and an auxiliary operator M π (z), when restricted to finite energy intervals, are trace class operators and have limits in trace norm for almost all values of the real energy; (2) the basic dynamical equation that determines the operator M π (z), when restricted to the space of trace class operators, has a real-energy limit in trace norm for almost all values of the real energy; (3) the real-energy limit of M π (z) is a solution of the real-energy limit equation; (4) the diagonal (on-shell) elements of the kernels of the real-energy limit of T π (z) and of all solutions of the real-energy limit equation exactly equal the on-shell transition operator, implying that the real-energy limit equation uniquely determines the physical transition amplitude; and (5) a sequence of approximate on-shell transition operators converges strongly to the exact on-shell transition operator. These mathematically rigorous results are believed to be the most general of their type for nonrelativistic N-body quantum scattering theories
Directory of Open Access Journals (Sweden)
Ali Hadi Abdulwahid
2016-12-01
Full Text Available Nowadays, the use of distributed generation (DG has increased because of benefits such as increased reliability, reduced losses, improvement in the line capacity, and less environmental pollution. The protection of microgrids, which consist of generation sources, is one of the most crucial concerns of basic distribution operators. One of the key issues in this field is the protection of microgrids against permanent and temporary failures by improving the safety and reliability of the network. The traditional method has a number of disadvantages. The reliability and stability of a power system in a microgrid depend to a great extent on the efficiency of the protection scheme. The application of Artificial Intelligence approaches was introduced recently in the protection of distribution networks. The fault detection method depends on differential relay based on Hilbert Space-Based Power (HSBP theory to achieve fastest primary protection. It is backed up by a total harmonic distortion (THD detection method that takes over in case of a failure in the primary method. The backup protection would be completely independent of the main protection. This is rarely attained in practice. This paper proposes a new algorithm to improve protection performance by adaptive network-based fuzzy inference system (ANFIS. The protection can be obtained in a novel way based on this theory. An advantage of this algorithm is that the protection system operates in fewer than two cycles after the occurrence of the fault. Another advantage is that the error detection is not dependent on the selection of threshold values, and all types of internal fault can identify and show that the algorithm operates correctly for all types of faults while preventing unwanted tripping, even if the data were distorted by current transformer (CT saturation or by data mismatches. The simulation results show that the proposed circuit can identify the faulty phase in the microgrid quickly and
Exponential Hilbert series of equivariant embeddings
Johnson, Wayne A.
2018-01-01
In this article, we study properties of the exponential Hilbert series of a $G$-equivariant projective variety, where $G$ is a semisimple, simply-connected complex linear algebraic group. We prove a relationship between the exponential Hilbert series and the degree and dimension of the variety. We then prove a combinatorial identity for the coefficients of the polynomial representing the exponential Hilbert series. This formula is used in examples to prove further combinatorial identities inv...
Space Synthetic Biology Project
Howard, David; Roman, Monsi; Mansell, James (Matt)
2015-01-01
Synthetic biology is an effort to make genetic engineering more useful by standardizing sections of genetic code. By standardizing genetic components, biological engineering will become much more similar to traditional fields of engineering, in which well-defined components and subsystems are readily available in markets. Specifications of the behavior of those components and subsystems can be used to model a system which incorporates them. Then, the behavior of the novel system can be simulated and optimized. Finally, the components and subsystems can be purchased and assembled to create the optimized system, which most often will exhibit behavior similar to that indicated by the model. The Space Synthetic Biology project began in 2012 as a multi-Center effort. The purpose of this project was to harness Synthetic Biology principals to enable NASA's missions. A central target for application was to Environmental Control & Life Support (ECLS). Engineers from NASA Marshall Space Flight Center's (MSFC's) ECLS Systems Development Branch (ES62) were brought into the project to contribute expertise in operational ECLS systems. Project lead scientists chose to pursue the development of bioelectrochemical technologies to spacecraft life support. Therefore, the ECLS element of the project became essentially an effort to develop a bioelectrochemical ECLS subsystem. Bioelectrochemical systems exploit the ability of many microorganisms to drive their metabolisms by direct or indirect utilization of electrical potential gradients. Whereas many microorganisms are capable of deriving the energy required for the processes of interest (such as carbon dioxide (CO2) fixation) from sunlight, it is believed that subsystems utilizing electrotrophs will exhibit smaller mass, volume, and power requirements than those that derive their energy from sunlight. In the first 2 years of the project, MSFC personnel conducted modeling, simulation, and conceptual design efforts to assist the
National Aeronautics and Space Administration — The Deep Space Habitat was closed out at the end of Fiscal Year 2013 (September 30, 2013). Results and select content have been incorporated into the new Exploration...
International Nuclear Information System (INIS)
Loubenets, Elena R.
2015-01-01
We prove the existence for each Hilbert space of the two new quasi hidden variable (qHV) models, statistically noncontextual and context-invariant, reproducing all the von Neumann joint probabilities via non-negative values of real-valued measures and all the quantum product expectations—via the qHV (classical-like) average of the product of the corresponding random variables. In a context-invariant model, a quantum observable X can be represented by a variety of random variables satisfying the functional condition required in quantum foundations but each of these random variables equivalently models X under all joint von Neumann measurements, regardless of their contexts. The proved existence of this model negates the general opinion that, in terms of random variables, the Hilbert space description of all the joint von Neumann measurements for dimH≥3 can be reproduced only contextually. The existence of a statistically noncontextual qHV model, in particular, implies that every N-partite quantum state admits a local quasi hidden variable model introduced in Loubenets [J. Math. Phys. 53, 022201 (2012)]. The new results of the present paper point also to the generality of the quasi-classical probability model proposed in Loubenets [J. Phys. A: Math. Theor. 45, 185306 (2012)
Projective limits of state spaces IV. Fractal label sets
Lanéry, Suzanne; Thiemann, Thomas
2018-01-01
Instead of formulating the state space of a quantum field theory over one big Hilbert space, it has been proposed by Kijowski (1977) to represent quantum states as projective families of density matrices over a collection of smaller, simpler Hilbert spaces (see Lanéry (2016) [1] for a concise introduction to this formalism). One can thus bypass the need to select a vacuum state for the theory, and still be provided with an explicit and constructive description of the quantum state space, at least as long as the label set indexing the projective structure is countable. Because uncountable label sets are much less practical in this context, we develop in the present article a general procedure to trim an originally uncountable label set down to countable cardinality. In particular, we investigate how to perform this tightening of the label set in a way that preserves both the physical content of the algebra of observables and its symmetries. This work is notably motivated by applications to the holonomy-flux algebra underlying Loop Quantum Gravity. Building on earlier work by Okołów (2013), a projective state space was introduced for this algebra in Lanéry and Thiemann (2016). However, the non-trivial structure of the holonomy-flux algebra prevents the construction of satisfactory semi-classical states (Lanéry and Thiemann, 2017). Implementing the general procedure just mentioned in the case of a one-dimensional version of this algebra, we show how a discrete subalgebra can be extracted without destroying universality nor diffeomorphism invariance. On this subalgebra, quantum states can then be constructed which are more regular than was possible on the original algebra. In particular, this allows the design of semi-classical states whose semi-classicality is enforced step by step, starting from collective, macroscopic degrees of freedom and going down progressively toward smaller and smaller scales.
Compact Hilbert Curve Index Algorithm Based on Gray Code
Directory of Open Access Journals (Sweden)
CAO Xuefeng
2016-12-01
Full Text Available Hilbert curve has best clustering in various kinds of space filling curves, and has been used as an important tools in discrete global grid spatial index design field. But there are lots of redundancies in the standard Hilbert curve index when the data set has large differences between dimensions. In this paper, the construction features of Hilbert curve is analyzed based on Gray code, and then the compact Hilbert curve index algorithm is put forward, in which the redundancy problem has been avoided while Hilbert curve clustering preserved. Finally, experiment results shows that the compact Hilbert curve index outperforms the standard Hilbert index, their 1 computational complexity is nearly equivalent, but the real data set test shows the coding time and storage space decrease 40%, the speedup ratio of sorting speed is nearly 4.3.
Indian Academy of Sciences (India)
Usha N Bhosle. Acknowledgements. This work was initiated during the author's visit to the Isaac Newton Institute, Cambridge,. UK as a visiting fellow to participate in the programme Moduli Spaces (MOS) during. June 2011. She would like to thank the Institute for hospitality and excellent working environment. References.
Projective limits of state spaces II. Quantum formalism
Lanéry, Suzanne; Thiemann, Thomas
2017-06-01
In this series of papers, we investigate the projective framework initiated by Kijowski (1977) and Okołów (2009, 2014, 2013), which describes the states of a quantum theory as projective families of density matrices. A short reading guide to the series can be found in Lanéry (2016). After discussing the formalism at the classical level in a first paper (Lanéry, 2017), the present second paper is devoted to the quantum theory. In particular, we inspect in detail how such quantum projective state spaces relate to inductive limit Hilbert spaces and to infinite tensor product constructions (Lanéry, 2016, subsection 3.1) [1]. Regarding the quantization of classical projective structures into quantum ones, we extend the results by Okołów (2013), that were set up in the context of linear configuration spaces, to configuration spaces given by simply-connected Lie groups, and to holomorphic quantization of complex phase spaces (Lanéry, 2016, subsection 2.2) [1].
2013-01-01
David Hilbert was one of the great mathematicians who expounded the centrality of their subject in human thought. In this collection of essays, Wilfried Sieg frames Hilbert's foundational work, from 1890 to 1939, in a comprehensive way and integrates it with modern proof theoretic investigations. Ten essays are devoted to the analysis of classical as well as modern proof theory; three papers on the mathematical roots of Hilbert's work precede the analytical core, and three final essays exploit an open philosophical horizon for reflection on the nature of mathematics in the 21st century.
Chinese Manned Space Utility Project
Gu, Y.
Since 1992 China has been carrying out a conspicuous manned space mission A utility project has been defined and created during the same period The Utility Project of the Chinese Manned Space Mission involves wide science areas such as earth observation life science micro-gravity fluid physics and material science astronomy space environment etc In the earth observation area it is focused on the changes of global environments and relevant exploration technologies A Middle Revolution Image Spectrometer and a Multi-model Micro-wave Remote Sensor have been developed The detectors for cirrostratus distribution solar constant earth emission budget earth-atmosphere ultra-violet spectrum and flux have been manufactured and tested All of above equipment was engaged in orbital experiments on-board the Shenzhou series spacecrafts Space life science biotechnologies and micro-gravity science were much concerned with the project A series of experiments has been made both in ground laboratories and spacecraft capsules The environmental effect in different biological bodies in space protein crystallization electrical cell-fusion animal cells cultural research on separation by using free-low electrophoresis a liquid drop Marangoni migration experiment under micro-gravity as well as a set of crystal growth and metal processing was successfully operated in space The Gamma-ray burst and high-energy emission from solar flares have been explored A set of particle detectors and a mass spectrometer measured
2013-01-01
The book aims at nurturing theoretic reflection on the city and the territory and working out and applying methods and techniques for improving our physical and social landscapes. The main issue is developed around the projectual dimension, with the objective of visualising both the city and the territory from a particular viewpoint, which singles out the territorial dimension as the city’s space of communication and negotiation. Issues that characterise the dynamics of city development will be faced, such as the new, fresh relations between urban societies and physical space, the right to the city, urban equity, the project for the physical city as a means to reveal civitas, signs of new social cohesiveness, the sense of contemporary public space and the sustainability of urban development. Authors have been invited to explore topics that feature a pluralism of disciplinary contributions studying formal and informal practices on the project for the city and seeking conceptual and operative categories capab...
Nested Hilbert schemes on surfaces: Virtual fundamental class
DEFF Research Database (Denmark)
Gholampour, Amin; Sheshmani, Artan; Yau, Shing-Tung
We construct natural virtual fundamental classes for nested Hilbert schemes on a nonsingular projective surface S. This allows us to define new invariants of S that recover some of the known important cases such as Poincare invariants of Durr-Kabanov-Okonek and the stable pair invariants of Kool......-Thomas. In the case of the nested Hilbert scheme of points, we can express these invariants in terms of integrals over the products of Hilbert scheme of points on S, and relate them to the vertex operator formulas found by Carlsson-Okounkov. The virtual fundamental classes of the nested Hilbert schemes play a crucial...
Mathematical foundations of the projection-operator method
International Nuclear Information System (INIS)
Moore, S.M.
1979-01-01
Mathematical foundations are determined for the projection-operator method developed by Zwanzig and Mori and used in the study of cooperative phenomena in non-equilibrium processes. It is shown that the Hilbert space of operators can be taken as the Hilbert-Schmidt class. Comments are made on the possibility of a complete formulation of quantum mechanics in terms of this Hilbert space. (author)
Directory of Open Access Journals (Sweden)
F. O. Isiogugu
2016-01-01
Full Text Available The strong convergence of a hybrid algorithm to a common element of the fixed point sets of multivalued strictly pseudocontractive-type mappings and the set of solutions of an equilibrium problem in Hilbert spaces is obtained using a strict fixed point set condition. The obtained results improve, complement, and extend the results on multivalued and single-valued mappings in the contemporary literature.
Hilbert schemes of points and Heisenberg algebras
International Nuclear Information System (INIS)
Ellingsrud, G.; Goettsche, L.
2000-01-01
Let X [n] be the Hilbert scheme of n points on a smooth projective surface X over the complex numbers. In these lectures we describe the action of the Heisenberg algebra on the direct sum of the cohomologies of all the X [n] , which has been constructed by Nakajima. In the second half of the lectures we study the relation of the Heisenberg algebra action and the ring structures of the cohomologies of the X [n] , following recent work of Lehn. In particular we study the Chern and Segre classes of tautological vector bundles on the Hilbert schemes X [n] . (author)
Noise properties of Hilbert transform evaluation
Czech Academy of Sciences Publication Activity Database
Pavlíček, Pavel; Svak, V.
2015-01-01
Roč. 26, č. 8 (2015), s. 085207 ISSN 0957-0233 R&D Projects: GA ČR GA13-12301S Institutional support: RVO:68378271 Keywords : Hilbert transform * noise * measurement uncertainty * white -light interferometry * fringe-pattern analysis Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.492, year: 2015
A relative Hilbert-Mumford criterion
DEFF Research Database (Denmark)
Gulbrandsen, Martin G.; Halle, Lars Halvard; Hulek, Klaus
2015-01-01
We generalize the classical Hilbert-Mumford criteria for GIT (semi-)stability in terms of one parameter subgroups of a linearly reductive group G over a field k, to the relative situation of an equivariant, projective morphism X -> Spec A to a noetherian k-algebra A. We also extend the classical...
Quantum mechanics in Hilbert space
Prugovecki, Eduard
1981-01-01
A critical presentation of the basic mathematics of nonrelativistic quantum mechanics, this text is suitable for courses in functional analysis at the advanced undergraduate and graduate levels. Its readable and self-contained form is accessible even to students without an extensive mathematical background. Applications of basic theorems to quantum mechanics make it of particular interest to mathematicians working in functional analysis and related areas.This text features the rigorous proofs of all the main functional-analytic statements encountered in books on quantum mechanics. It fills the
Hilbert space and quantum mechanics
Gallone, Franco
2015-01-01
The topics of this book are the mathematical foundations of non-relativistic quantum mechanics and the mathematical theory they require. The main characteristic of the book is that the mathematics is developed assuming familiarity with elementary analysis only. Moreover, all the proofs are carried out in detail. These features make the book easily accessible to readers with only the mathematical training offered by undergraduate education in mathematics or in physics, and also ideal for individual study. The principles of quantum mechanics are discussed with complete mathematical accuracy and an effort is made to always trace them back to the experimental reality that lies at their root. The treatment of quantum mechanics is axiomatic, with definitions followed by propositions proved in a mathematical fashion. No previous knowledge of quantum mechanics is required. This book is designed so that parts of it can be easily used for various courses in mathematics and mathematical physics, as suggested in the Pref...
Functional Analysis: Entering Hilbert Space
DEFF Research Database (Denmark)
Hansen, Vagn Lundsgaard
in a new chapter on Fredholm theory (Chapter 6). Fredholm theory originates in pioneering work of the Swedish mathematician Erik Ivar Fred-holm on integral equations, which inspired the study of a new class of bounded linear operators, known as Fredholm operators. Chapter 6 presents the basic elements...
Hilbert schemes of points and infinite dimensional Lie algebras
Qin, Zhenbo
2018-01-01
Hilbert schemes, which parametrize subschemes in algebraic varieties, have been extensively studied in algebraic geometry for the last 50 years. The most interesting class of Hilbert schemes are schemes X^{[n]} of collections of n points (zero-dimensional subschemes) in a smooth algebraic surface X. Schemes X^{[n]} turn out to be closely related to many areas of mathematics, such as algebraic combinatorics, integrable systems, representation theory, and mathematical physics, among others. This book surveys recent developments of the theory of Hilbert schemes of points on complex surfaces and its interplay with infinite dimensional Lie algebras. It starts with the basics of Hilbert schemes of points and presents in detail an example of Hilbert schemes of points on the projective plane. Then the author turns to the study of cohomology of X^{[n]}, including the construction of the action of infinite dimensional Lie algebras on this cohomology, the ring structure of cohomology, equivariant cohomology of X^{[n]} a...
Space Mission Human Reliability Analysis (HRA) Project
National Aeronautics and Space Administration — The purpose of this project is to extend current ground-based Human Reliability Analysis (HRA) techniques to a long-duration, space-based tool to more effectively...
Hilbert schemes of points on some classes surface singularities
Gyenge, Ádám
2016-01-01
We study the geometry and topology of Hilbert schemes of points on the orbifold surface [C^2/G], respectively the singular quotient surface C^2/G, where G is a finite subgroup of SL(2,C) of type A or D. We give a decomposition of the (equivariant) Hilbert scheme of the orbifold into affine space strata indexed by a certain combinatorial set, the set of Young walls. The generating series of Euler characteristics of Hilbert schemes of points of the singular surface of type A or D is computed in...
Lectures on Hilbert schemes of points on surfaces
Nakajima, Hiraku
1999-01-01
This beautifully written book deals with one shining example: the Hilbert schemes of points on algebraic surfaces ... The topics are carefully and tastefully chosen ... The young person will profit from reading this book. --Mathematical Reviews The Hilbert scheme of a surface X describes collections of n (not necessarily distinct) points on X. More precisely, it is the moduli space for 0-dimensional subschemes of X of length n. Recently it was realized that Hilbert schemes originally studied in algebraic geometry are closely related to several branches of mathematics, such as singularities, symplectic geometry, representation theory--even theoretical physics. The discussion in the book reflects this feature of Hilbert schemes. One example of the modern, broader interest in the subject is a construction of the representation of the infinite-dimensional Heisenberg algebra, i.e., Fock space. This representation has been studied extensively in the literature in connection with affine Lie algebras, conformal field...
Life sciences space biology project planning
Primeaux, G.; Newkirk, K.; Miller, L.; Lewis, G.; Michaud, R.
1988-01-01
The Life Sciences Space Biology (LSSB) research will explore the effect of microgravity on humans, including the physiological, clinical, and sociological implications of space flight and the readaptations upon return to earth. Physiological anomalies from past U.S. space flights will be used in planning the LSSB project.The planning effort integrates science and engineering. Other goals of the LSSB project include the provision of macroscopic view of the earth's biosphere, and the development of spinoff technology for application on earth.
Banach spaces with projectional skeletons
Czech Academy of Sciences Publication Activity Database
Kubiś, Wieslaw
2009-01-01
Roč. 350, č. 2 (2009), s. 758-776 ISSN 0022-247X Institutional research plan: CEZ:AV0Z10190503 Keywords : projection * projectional skeleton * norming set Subject RIV: BA - General Mathematics Impact factor: 1.225, year: 2009
A note on the von Neumann alternating projections algorithm
Czech Academy of Sciences Publication Activity Database
Kopecká, Eva; Reich, S.
2004-01-01
Roč. 5, č. 3 (2004), s. 379-386 ISSN 1345-4773 Institutional research plan: CEZ:AV0Z1019905 Keywords : alternating orthogonal projections * Hilbert space * nearest point mapping Subject RIV: BA - General Mathematics
Live from Space Station Learning Technologies Project
2001-01-01
This is the Final Report for the Live From Space Station (LFSS) project under the Learning Technologies Project FY 2001 of the MSFC Education Programs Department. AZ Technology, Inc. (AZTek) has developed and implemented science education software tools to support tasks under the LTP program. Initial audience consisted of 26 TreK in the Classroom schools and thousands of museum visitors to the International Space Station: The Earth Tour exhibit sponsored by Discovery Place museum.
Cuspidal discrete series for projective hyperbolic spaces
DEFF Research Database (Denmark)
Andersen, Nils Byrial; Flensted-Jensen, Mogens
2013-01-01
Abstract. We have in [1] proposed a definition of cusp forms on semisimple symmetric spaces G/H, involving the notion of a Radon transform and a related Abel transform. For the real non-Riemannian hyperbolic spaces, we showed that there exists an infinite number of cuspidal discrete series......, and at most finitely many non-cuspidal discrete series, including in particular the spherical discrete series. For the projective spaces, the spherical discrete series are the only non-cuspidal discrete series. Below, we extend these results to the other hyperbolic spaces, and we also study the question...
Projective flatness in the quantisation of bosons and fermions
Wu, Siye
2015-07-01
We compare the quantisation of linear systems of bosons and fermions. We recall the appearance of projectively flat connection and results on parallel transport in the quantisation of bosons. We then discuss pre-quantisation and quantisation of fermions using the calculus of fermionic variables. We define a natural connection on the bundle of Hilbert spaces and show that it is projectively flat. This identifies, up to a phase, equivalent spinor representations constructed by various polarisations. We introduce the concept of metaplectic correction for fermions and show that the bundle of corrected Hilbert spaces is naturally flat. We then show that the parallel transport in the bundle of Hilbert spaces along a geodesic is a rescaled projection provided that the geodesic lies within the complement of a cut locus. Finally, we study the bundle of Hilbert spaces when there is a symmetry.
Space Mission Human Reliability Analysis (HRA) Project
Boyer, Roger
2014-01-01
The purpose of the Space Mission Human Reliability Analysis (HRA) Project is to extend current ground-based HRA risk prediction techniques to a long-duration, space-based tool. Ground-based HRA methodology has been shown to be a reasonable tool for short-duration space missions, such as Space Shuttle and lunar fly-bys. However, longer-duration deep-space missions, such as asteroid and Mars missions, will require the crew to be in space for as long as 400 to 900 day missions with periods of extended autonomy and self-sufficiency. Current indications show higher risk due to fatigue, physiological effects due to extended low gravity environments, and others, may impact HRA predictions. For this project, Safety & Mission Assurance (S&MA) will work with Human Health & Performance (HH&P) to establish what is currently used to assess human reliabiilty for human space programs, identify human performance factors that may be sensitive to long duration space flight, collect available historical data, and update current tools to account for performance shaping factors believed to be important to such missions. This effort will also contribute data to the Human Performance Data Repository and influence the Space Human Factors Engineering research risks and gaps (part of the HRP Program). An accurate risk predictor mitigates Loss of Crew (LOC) and Loss of Mission (LOM).The end result will be an updated HRA model that can effectively predict risk on long-duration missions.
Hilbert W*-modules and coherent states
International Nuclear Information System (INIS)
Bhattacharyya, T; Roy, S Shyam
2012-01-01
Hilbert C*-module valued coherent states was introduced earlier by Ali, Bhattacharyya and Shyam Roy. We consider the case when the underlying C*-algebra is a W*-algebra. The construction is similar with a substantial gain. The associated reproducing kernel is now algebra valued, rather than taking values in the space of bounded linear operators between two C*-algebras. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’. (paper)
Design methodology and projects for space engineering
Nichols, S.; Kleespies, H.; Wood, K.; Crawford, R.
1993-01-01
NASA/USRA is an ongoing sponsor of space design projects in the senior design course of the Mechanical Engineering Department at The University of Texas at Austin. This paper describes the UT senior design sequence, consisting of a design methodology course and a capstone design course. The philosophical basis of this sequence is briefly summarized. A history of the Department's activities in the Advanced Design Program is then presented. The paper concludes with a description of the projects completed during the 1991-92 academic year and the ongoing projects for the Fall 1992 semester.
NASA rocket launches student project into space
Crumbley, Liz
2005-01-01
A project that began in 2002 will culminate at sunrise on Tuesday, March 15, when a team of Virginia Tech engineering students watch a payload section they designed lift off aboard a sounding rocket from a launch pad at NASA's Wallops Island Flight Facility and travel 59 miles into space.
Topological freeness for Hilbert bimodules
DEFF Research Database (Denmark)
Kwasniewski, Bartosz
2014-01-01
It is shown that topological freeness of Rieffel’s induced representation functor implies that any C*-algebra generated by a faithful covariant representation of a Hilbert bimodule X over a C*-algebra A is canonically isomorphic to the crossed product A ⋊ X ℤ. An ideal lattice description...
The NASA Advanced Space Power Systems Project
Mercer, Carolyn R.; Hoberecht, Mark A.; Bennett, William R.; Lvovich, Vadim F.; Bugga, Ratnakumar
2015-01-01
The goal of the NASA Advanced Space Power Systems Project is to develop advanced, game changing technologies that will provide future NASA space exploration missions with safe, reliable, light weight and compact power generation and energy storage systems. The development effort is focused on maturing the technologies from a technology readiness level of approximately 23 to approximately 56 as defined in the NASA Procedural Requirement 7123.1B. Currently, the project is working on two critical technology areas: High specific energy batteries, and regenerative fuel cell systems with passive fluid management. Examples of target applications for these technologies are: extending the duration of extravehicular activities (EVA) with high specific energy and energy density batteries; providing reliable, long-life power for rovers with passive fuel cell and regenerative fuel cell systems that enable reduced system complexity. Recent results from the high energy battery and regenerative fuel cell technology development efforts will be presented. The technical approach, the key performance parameters and the technical results achieved to date in each of these new elements will be included. The Advanced Space Power Systems Project is part of the Game Changing Development Program under NASAs Space Technology Mission Directorate.
Four-dimensional hilbert curves for R-trees
DEFF Research Database (Denmark)
Haverkort, Herman; Walderveen, Freek van
2011-01-01
Two-dimensional R-trees are a class of spatial index structures in which objects are arranged to enable fast window queries: report all objects that intersect a given query window. One of the most successful methods of arranging the objects in the index structure is based on sorting the objects...... according to the positions of their centers along a two-dimensional Hilbert space-filling curve. Alternatively, one may use the coordinates of the objects' bounding boxes to represent each object by a four-dimensional point, and sort these points along a four-dimensional Hilbert-type curve. In experiments...
Lectures on Hilbert modular varieties and modular forms
Goren, Eyal Z
2001-01-01
This book is devoted to certain aspects of the theory of p-adic Hilbert modular forms and moduli spaces of abelian varieties with real multiplication. The theory of p-adic modular forms is presented first in the elliptic case, introducing the reader to key ideas of N. M. Katz and J.-P. Serre. It is re-interpreted from a geometric point of view, which is developed to present the rudiments of a similar theory for Hilbert modular forms. The theory of moduli spaces of abelian varieties with real multiplication is presented first very explicitly over the complex numbers. Aspects of the general theory are then exposed, in particular, local deformation theory of abelian varieties in positive characteristic. The arithmetic of p-adic Hilbert modular forms and the geometry of moduli spaces of abelian varieties are related. This relation is used to study q-expansions of Hilbert modular forms, on the one hand, and stratifications of moduli spaces on the other hand. The book is addressed to graduate students and non-exper...
Project Mercury: NASA's first manned space programme
Catchpole, John
Project Mercury will offer a developmental resume of the first American manned spaceflight programme and its associated infrastructure, including accounts of space launch vehicles. The book highlights the differences in Redstone/Atlas technology, drawing similar comparisons between ballistic capsules and alternative types of spacecraft. The book also covers astronaut selection and training, as well as tracking systems, flight control, basic principles of spaceflight and detailed accounts of individual flights.
Projection x-space magnetic particle imaging.
Goodwill, Patrick W; Konkle, Justin J; Zheng, Bo; Saritas, Emine U; Conolly, Steven M
2012-05-01
Projection magnetic particle imaging (MPI) can improve imaging speed by over 100-fold over traditional 3-D MPI. In this work, we derive the 2-D x-space signal equation, 2-D image equation, and introduce the concept of signal fading and resolution loss for a projection MPI imager. We then describe the design and construction of an x-space projection MPI scanner with a field gradient of 2.35 T/m across a 10 cm magnet free bore. The system has an expected resolution of 3.5 × 8.0 mm using Resovist tracer, and an experimental resolution of 3.8 × 8.4 mm resolution. The system images 2.5 cm × 5.0 cm partial field-of views (FOVs) at 10 frames/s, and acquires a full field-of-view of 10 cm × 5.0 cm in 4 s. We conclude by imaging a resolution phantom, a complex "Cal" phantom, mice injected with Resovist tracer, and experimentally confirm the theoretically predicted x-space spatial resolution.
Computing Instantaneous Frequency by normalizing Hilbert Transform
Huang, Norden E.
2005-05-31
This invention presents Normalized Amplitude Hilbert Transform (NAHT) and Normalized Hilbert Transform(NHT), both of which are new methods for computing Instantaneous Frequency. This method is designed specifically to circumvent the limitation set by the Bedorsian and Nuttal Theorems, and to provide a sharp local measure of error when the quadrature and the Hilbert Transform do not agree. Motivation for this method is that straightforward application of the Hilbert Transform followed by taking the derivative of the phase-angle as the Instantaneous Frequency (IF) leads to a common mistake made up to this date. In order to make the Hilbert Transform method work, the data has to obey certain restrictions.
The ESA Space Weather Applications Pilot Project
Glover, A.; Hilgers, A.; Daly, E.
Following the completion in 2001 of two parallel studies to consider the feasibility of a European Space Weather Programme ESA embarked upon a space weather pilot study with the goal of prototyping European space weather services and assessing the overall market for such within Europe This pilot project centred on a number of targeted service development activities supported by a common infrastructure and making use of only existing space weather assets Each service activity included clear participation from at least one identified service user who was requested to provide initial requirements and regular feedback during the operational phase of the service These service activities are now reaching the end of their 2-year development and testing phase and are now accessible each with an element of the service in the public domain see http www esa-spaceweathet net swenet An additional crucial element of the study was the inclusion of a comprehensive and independent analysis of the benefits both economic and strategic of embarking on a programme which would include the deployment of an infrastructure with space-based elements The results of this study will be reported together with their implication for future coordinated European activities in this field
A product of three projections
Czech Academy of Sciences Publication Activity Database
Kopecká, E.; Müller, Vladimír
2014-01-01
Roč. 223, č. 2 (2014), s. 175-186 ISSN 0039-3223 R&D Projects: GA ČR(CZ) GA14-07880S Institutional support: RVO:67985840 Keywords : Hilbert space * projection * extension Subject RIV: BA - General Mathematics Impact factor: 0.610, year: 2014 http://journals.impan.pl/cgi-bin/doi?sm223-2-4
Liquid identification by Hilbert spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Lyatti, M; Divin, Y; Poppe, U; Urban, K, E-mail: M.Lyatti@fz-juelich.d, E-mail: Y.Divin@fz-juelich.d [Forschungszentrum Juelich, 52425 Juelich (Germany)
2009-11-15
Fast and reliable identification of liquids is of great importance in, for example, security, biology and the beverage industry. An unambiguous identification of liquids can be made by electromagnetic measurements of their dielectric functions in the frequency range of their main dispersions, but this frequency range, from a few GHz to a few THz, is not covered by any conventional spectroscopy. We have developed a concept of liquid identification based on our new Hilbert spectroscopy and high- T{sub c} Josephson junctions, which can operate at the intermediate range from microwaves to THz frequencies. A demonstration setup has been developed consisting of a polychromatic radiation source and a compact Hilbert spectrometer integrated in a Stirling cryocooler. Reflection polychromatic spectra of various bottled liquids have been measured at the spectral range of 15-300 GHz with total scanning time down to 0.2 s and identification of liquids has been demonstrated.
Liquid identification by Hilbert spectroscopy
Lyatti, M.; Divin, Y.; Poppe, U.; Urban, K.
2009-11-01
Fast and reliable identification of liquids is of great importance in, for example, security, biology and the beverage industry. An unambiguous identification of liquids can be made by electromagnetic measurements of their dielectric functions in the frequency range of their main dispersions, but this frequency range, from a few GHz to a few THz, is not covered by any conventional spectroscopy. We have developed a concept of liquid identification based on our new Hilbert spectroscopy and high- Tc Josephson junctions, which can operate at the intermediate range from microwaves to THz frequencies. A demonstration setup has been developed consisting of a polychromatic radiation source and a compact Hilbert spectrometer integrated in a Stirling cryocooler. Reflection polychromatic spectra of various bottled liquids have been measured at the spectral range of 15-300 GHz with total scanning time down to 0.2 s and identification of liquids has been demonstrated.
Liquid identification by Hilbert spectroscopy
International Nuclear Information System (INIS)
Lyatti, M; Divin, Y; Poppe, U; Urban, K
2009-01-01
Fast and reliable identification of liquids is of great importance in, for example, security, biology and the beverage industry. An unambiguous identification of liquids can be made by electromagnetic measurements of their dielectric functions in the frequency range of their main dispersions, but this frequency range, from a few GHz to a few THz, is not covered by any conventional spectroscopy. We have developed a concept of liquid identification based on our new Hilbert spectroscopy and high- T c Josephson junctions, which can operate at the intermediate range from microwaves to THz frequencies. A demonstration setup has been developed consisting of a polychromatic radiation source and a compact Hilbert spectrometer integrated in a Stirling cryocooler. Reflection polychromatic spectra of various bottled liquids have been measured at the spectral range of 15-300 GHz with total scanning time down to 0.2 s and identification of liquids has been demonstrated.
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.)
VLBI2010 in NASA's Space Geodesy Project
Ma, Chopo
2012-01-01
In the summer of 20 11 NASA approved the proposal for the Space Geodesy Project (SGP). A major element is developing at the Goddard Geophysical and Astronomical Observatory a prototype of the next generation of integrated stations with co-located VLBI, SLR, GNSS and DORIS instruments as well as a system for monitoring the vector ties. VLBI2010 is a key component of the integrated station. The objectives ofSGP, the role of VLBI20 lOin the context of SGP, near term plans and possible future scenarios will be discussed.
Vector bundles on complex projective spaces
Okonek, Christian; Spindler, Heinz
1980-01-01
This expository treatment is based on a survey given by one of the authors at the Séminaire Bourbaki in November 1978 and on a subsequent course held at the University of Göttingen. It is intended to serve as an introduction to the topical question of classification of holomorphic vector bundles on complex projective spaces, and can easily be read by students with a basic knowledge of analytic or algebraic geometry. Short supplementary sections describe more advanced topics, further results, and unsolved problems.
On the projective curvature tensor of generalized Sasakian-space ...
African Journals Online (AJOL)
space-forms under some conditions regarding projective curvature tensor. All the results obtained in this paper are in the form of necessary and sufficient conditions. Keywords: Generalized Sasakian-space-forms; projectively flat; ...
Czech Academy of Sciences Publication Activity Database
Pittner, Jiří
2003-01-01
Roč. 118, č. 24 (2003), s. 10876-10889 ISSN 0021-9606 R&D Projects: GA MŠk OC D23.001; GA ČR GA203/99/D009; GA AV ČR IAA4040108 Institutional research plan: CEZ:AV0Z4040901 Keywords : continuous transition * Brillouin-Wigner * Rayleigh-Schrödinger Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.950, year: 2003
TRI-Worthy Projects for the Deep Space Gateway
Wotring, V. E.; Strangman, G. E.; Donoviel, D.
2018-02-01
Preparations for exploration will require exposure to the actual deep space environment. The new TRI for Space Health proposes innovative projects using real space radiation to make medically-relevant measurements affecting human physiology.
Clustering in Hilbert simplex geometry
Nielsen, Frank
2017-04-03
Clustering categorical distributions in the probability simplex is a fundamental primitive often met in applications dealing with histograms or mixtures of multinomials. Traditionally, the differential-geometric structure of the probability simplex has been used either by (i) setting the Riemannian metric tensor to the Fisher information matrix of the categorical distributions, or (ii) defining the information-geometric structure induced by a smooth dissimilarity measure, called a divergence. In this paper, we introduce a novel computationally-friendly non-Riemannian framework for modeling the probability simplex: Hilbert simplex geometry. We discuss the pros and cons of those three statistical modelings, and compare them experimentally for clustering tasks.
Regularization methods for ill-posed problems in multiple Hilbert scales
International Nuclear Information System (INIS)
Mazzieri, Gisela L; Spies, Ruben D
2012-01-01
Several convergence results in Hilbert scales under different source conditions are proved and orders of convergence and optimal orders of convergence are derived. Also, relations between those source conditions are proved. The concept of a multiple Hilbert scale on a product space is introduced, and regularization methods on these scales are defined, both for the case of a single observation and for the case of multiple observations. In the latter case, it is shown how vector-valued regularization functions in these multiple Hilbert scales can be used. In all cases, convergence is proved and orders and optimal orders of convergence are shown. Finally, some potential applications and open problems are discussed. (paper)
6th Hilbert's problem and S.Lie's infinite groups
International Nuclear Information System (INIS)
Konopleva, N.P.
1999-01-01
The progress in Hilbert's sixth problem solving is demonstrated. That became possible thanks to the gauge field theory in physics and to the geometrical treatment of the gauge fields. It is shown that the fibre bundle spaces geometry is the best basis for solution of the problem being discussed. This talk has been reported at the International Seminar '100 Years after Sophus Lie' (Leipzig, Germany)
Quantum mechanics: why complex Hilbert space?
Cassinelli, G; Lahti, P
2017-11-13
We outline a programme for an axiomatic reconstruction of quantum mechanics based on the statistical duality of states and effects that combines the use of a theorem of Solér with the idea of symmetry. We also discuss arguments favouring the choice of the complex field.This article is part of the themed issue 'Second quantum revolution: foundational questions'. © 2017 The Author(s).
Hilbert space theory of classical electrodynamics
Indian Academy of Sciences (India)
Furthermore, following Bondar et al, {\\it Phys. Rev.} A 88, 052108 (2013), it is pointed out that quantum processes that preserve the positivity or nonpositivity of theWigner function can be implemented by classical optics. This may be useful in interpreting quantum information processing in terms of classical optics.
Quantum mechanics: why complex Hilbert space?
Cassinelli, G.; Lahti, P.
2017-10-01
We outline a programme for an axiomatic reconstruction of quantum mechanics based on the statistical duality of states and effects that combines the use of a theorem of Solér with the idea of symmetry. We also discuss arguments favouring the choice of the complex field. This article is part of the themed issue `Second quantum revolution: foundational questions'.
Scientific projection paper for space radiobiological research
International Nuclear Information System (INIS)
Vinograd, S.P.
1980-01-01
A nationale for the radiobiological research requirements for space is rooted in a national commitment to the exploration of space, mandated in the form of the National Space Act. This research is almost entirely centered on man; more specifically, on the effects of the space radiation environment on man and his protection from them. The research needs discussed in this presentation include the space radiation environment; dosimetry; radiation biology-high LET particles (dose/response); and operational countermeasures
Space life sciences: Programs and projects
1989-01-01
NASA space life science activities are outlined. Brief, general descriptions are given of research in the areas of biomedical research, space biology, closed loop life support systems, exobiology, and biospherics.
Power Spectral Density and Hilbert Transform
2016-12-01
there is 1.3 W of power. How much bandwidth does a pure sine wave require? The bandwidth of an ideal sine wave is 0 Hz. How do you represent a 1-W...the Hilbert transform. 2.3 Hilbert Transform The Hilbert transform is a math function used to convert a real function into an analytic signal...The math operation minus 2 means to move 2 steps back on the number line. For minus –2, we move 2 steps backwards from –2, which is the same as
Frame transforms, star products and quantum mechanics on phase space
International Nuclear Information System (INIS)
Aniello, P; Marmo, G; Man'ko, V I
2008-01-01
Using the notions of frame transform and of square integrable projective representation of a locally compact group G, we introduce a class of isometries (tight frame transforms) from the space of Hilbert-Schmidt operators in the carrier Hilbert space of the representation into the space of square integrable functions on the direct product group G x G. These transforms have remarkable properties. In particular, their ranges are reproducing kernel Hilbert spaces endowed with a suitable 'star product' which mimics, at the level of functions, the original product of operators. A 'phase space formulation' of quantum mechanics relying on the frame transforms introduced in the present paper, and the link of these maps with both the Wigner transform and the wavelet transform are discussed
Moduli spaces of convex projective structures on surfaces
DEFF Research Database (Denmark)
Fock, V. V.; Goncharov, A. B.
2007-01-01
We introduce explicit parametrisations of the moduli space of convex projective structures on surfaces, and show that the latter moduli space is identified with the higher Teichmüller space for defined in [V.V. Fock, A.B. Goncharov, Moduli spaces of local systems and higher Teichmüller theory, math.......AG/0311149]. We investigate the cluster structure of this moduli space, and define its quantum version....
In-Space Propulsion (346620) Technology Project
National Aeronautics and Space Administration — Technologies include, but are not limited to, electric and advanced chemical propulsion, propellantless propulsion such as aerocapture and solar sails, sample return...
Projective invariants in a conformal finsler space - I
International Nuclear Information System (INIS)
Mishra, C.K.; Singh, M.P.
1989-12-01
The projective invariants in a conformal Finsler space have been studied in regard to certain tensor and scalar which are invariant under projective transformation in a Finsler space. They have been the subject of further investigation by the present authors. (author). 8 refs
Activities of NICT space weather project
Murata, Ken T.; Nagatsuma, Tsutomu; Watari, Shinichi; Shinagawa, Hiroyuki; Ishii, Mamoru
NICT (National Institute of Information and Communications Technology) has been in charge of space weather forecast service in Japan for more than 20 years. The main target region of the space weather is the geo-space in the vicinity of the Earth where human activities are dominant. In the geo-space, serious damages of satellites, international space stations and astronauts take place caused by energetic particles or electromagnetic disturbances: the origin of the causes is dynamically changing of solar activities. Positioning systems via GPS satellites are also im-portant recently. Since the most significant effect of positioning error comes from disturbances of the ionosphere, it is crucial to estimate time-dependent modulation of the electron density profiles in the ionosphere. NICT is one of the 13 members of the ISES (International Space Environment Service), which is an international assembly of space weather forecast centers under the UNESCO. With help of geo-space environment data exchanging among the member nations, NICT operates daily space weather forecast service every day to provide informa-tion on forecasts of solar flare, geomagnetic disturbances, solar proton event, and radio-wave propagation conditions in the ionosphere. The space weather forecast at NICT is conducted based on the three methodologies: observations, simulations and informatics (OSI model). For real-time or quasi real-time reporting of space weather, we conduct our original observations: Hiraiso solar observatory to monitor the solar activity (solar flare, coronal mass ejection, and so on), domestic ionosonde network, magnetometer HF radar observations in far-east Siberia, and south-east Asia low-latitude ionosonde network (SEALION). Real-time observation data to monitor solar and solar-wind activities are obtained through antennae at NICT from ACE and STEREO satellites. We have a middle-class super-computer (NEC SX-8R) to maintain real-time computer simulations for solar and solar
Hilbert transform and optical tomography for anisotropic edge enhancement of phase objects
International Nuclear Information System (INIS)
Montes-Perez, Areli; Meneses-Fabian, Cruz; Rodriguez-Zurita, Gustavo
2011-01-01
In phase object tomography a slice reconstruction is related to distribution of refractive index. Typically, this is obtained by applying the filtered back-projection algorithm to the set of projections (sinogram) obtained experimentally, which are sequentially obtained by calculating the phase of the wave emerging from the slice of the object at different angles. In this paper, based on optical implementation of the Hilbert-transform in a 4f Fourier operator, the Hilbert transform of the projections leaving of the object are obtained numerically. When these projection data are captured for a set of viewing angles an unconventional sinogram is eventually obtained, we have called it as an Hilbert-sinogram. The reconstruction obtained by applying the filtered back-projection algorithm is proportional to the Hilbert transform of the distribution of refractive index of the slice and the obtained image shows a typical isotropic edge enhancement. In this manuscript, the theoretical analysis and the numerical implementation of the Hilbert-transform, mathematical model of the edge enhancement reconstructed are extensively detailed.
String cohomology groups of complex projective spaces
DEFF Research Database (Denmark)
Ottosen, Iver; Bökstedt, Marcel
2007-01-01
Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p. The compu......Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p...
Bundles over Quantum RealWeighted Projective Spaces
Directory of Open Access Journals (Sweden)
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.
Space technology and robotics in school projects
Villias, Georgios
2016-04-01
Space-related educational activities is a very inspiring and attractive way to involve students into science courses, present them the variety of STEM careers that they can follow, while giving them at the same time the opportunity to develop various practical and communication skills necessary for their future professional development. As part of a large scale extracurricular course in Space Science, Space Technology and Robotics that has been introduced in our school, our students, divided in smaller groups of 3-4 students in each, try to understand the challenges that current and future space exploration is facing. Following a mixture of an inquiry-based learning methodology and hands-on practical activities related with constructions and experiments, students get a glimpse of the pre-mentioned fields. Our main goal is to gain practical knowledge and inspiration from the exciting field of Space, to attain an adequate level of team spirit and effective cooperation, while developing technical and research data-mining skills. We use the following two approaches: 1. Constructive (Technical) approach Designing and constructing various customized robotic machines, that will simulate the future space exploration vehicles and satellites needed to study the atmosphere, surface and subsurface of planets, moons or other planetary bodies of our solar system that have shown some promising indications for the existence of life, taking seriously into account their special characteristics and known existing conditions (like Mars, Titan, Europa & Enceladus). The STEM tools we use are the following: - LEGO Mindstorms: to construct rovers for surface exploration. - Hydrobots: an MIT's SeaPerch program for the construction of submarine semi-autonomous robots. - CanSats: Arduino-based microsatellites able to receive, record & transmit data. - Space balloons: appropriate for high altitude atmospheric measurements & photography. 2. Scientific approach Conducting interesting physics
Real hypersurfaces of a complex projective space
Indian Academy of Sciences (India)
Kaehler manifolds of con- stant holomorphic sectional curvature c) is a very interesting and active area of research. The ambient space ¯M(c), specially in the case c = 0 imposes quite significant restrictions on the geometry of its real hypersurfaces.
Miller, R. H.; Minsky, M. L.; Smith, D. B. S.
1982-01-01
Applications of automation, robotics, and machine intelligence systems (ARAMIS) to space activities, and their related ground support functions are studied so that informed decisions can be made on which aspects of ARAMIS to develop. The space project breakdowns, which are used to identify tasks ('functional elements'), are described. The study method concentrates on the production of a matrix relating space project tasks to pieces of ARAMIS.
Rich families and projectional skeletons in Asplund WCG spaces
Czech Academy of Sciences Publication Activity Database
Cúth, M.; Fabian, Marián
2017-01-01
Roč. 448, č. 2 (2017), s. 1618-1632 ISSN 0022-247X R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : Asplund space * weakly compactly generated space * weakly Lindelöf determined space Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022247X16307715
Evaluating Quality in Educational Spaces: OECD/CELE Pilot Project
von Ahlefeld, Hannah
2009-01-01
CELE's International Pilot Project on Evaluating Quality in Educational Spaces aims to assist education authorities, schools and others to maximise the use of and investment in learning environments. This article provides an update on the pilot project, which is currently being implemented in Brazil, Mexico, New Zealand, Portugal and the United…
Strategic Project Management at the NASA Kennedy Space Center
Lavelle, Jerome P.
2000-01-01
This paper describes Project Management at NASA's Kennedy Space Center (KSC) from a strategic perspective. It develops the historical context of the agency and center's strategic planning process and illustrates how now is the time for KSC to become a center which has excellence in project management. The author describes project management activities at the center and details observations on those efforts. Finally the author describes the Strategic Project Management Process Model as a conceptual model which could assist KSC in defining an appropriate project management process system at the center.
Green Applications for Space Power Project
Robinson, Joel (Principal Investigator)
2014-01-01
Spacecraft propulsion and power for many decades has relied on Hydrazine monopropellant technology for auxiliary power units (APU), orbital circularization, orbit raising/lowering and attitude control. However, Hydrazine is toxic and therefore requires special ground handling procedures to ensure launch crew safety. The Swedish Company ECAPS has developed a technology based upon the propellant Ammonium Dinitramide (ADN) that offers higher performance, higher density and reduced ground handling support than Hydrazine. This blended propellant is called LMP-103S. Currently, the United States Air Force (USAF) is pursuing a technology based on Hydroxyl Ammonium Nitrate (HAN, otherwise known as AF-M315E) with industry partners Aerojet and Moog. Based on the advantages offered by these propellants, MSFC should explore powering APU's with these propellants. Due to the availability of space hardware, the principal investigator has found a collection of USAF hardware, that will act as a surrogate, which operates on a Hydrazine derivative. The F-16 fighter jet uses H-70 or 30% diluted Hydrazine for an Emergency Power Unit (EPU) which supplies power to the plane. The PI has acquired two EPU's from planes slated for destruction at the Davis Monthan AFB. This CIF will include a partnership with 2 other NASA Centers who are individually seeking seed funds from their respective organizations: Kennedy Space Center (KSC) and Dryden Flight Research Center (DFRC). KSC is preparing for future flights from their launch pads that will utilize green propellants and desire a low-cost testbed in which to test and calibrate new leak detection sensors. DFRC has access to F-16's which can be used by MSFC & KSC to perform a ground test that demonstrates emergency power supplied to the jet. Neither of the green propellant alternatives have been considered nor evaluated for an APU application. Work has already been accomplished to characterize and obtain the properties of these 2 propellants
Projections in duals to Asplund spaces made without Simons' lemma
Czech Academy of Sciences Publication Activity Database
Cúth, M.; Fabian, Marián
2015-01-01
Roč. 143, č. 1 (2015), s. 301-308 ISSN 0002-9939 R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : Asplund space * projectional resolution of identity * projectional skeleton Subject RIV: BA - General Mathematics Impact factor: 0.700, year: 2015 http://www.ams.org/journals/proc/2015-143-01/S0002-9939-2014-12300-8/
NASA Space Flight Program and Project Management Handbook
Blythe, Michael P.; Saunders, Mark P.; Pye, David B.; Voss, Linda D.; Moreland, Robert J.; Symons, Kathleen E.; Bromley, Linda K.
2014-01-01
This handbook is a companion to NPR 7120.5E, NASA Space Flight Program and Project Management Requirements and supports the implementation of the requirements by which NASA formulates and implements space flight programs and projects. Its focus is on what the program or project manager needs to know to accomplish the mission, but it also contains guidance that enhances the understanding of the high-level procedural requirements. (See Appendix C for NPR 7120.5E requirements with rationale.) As such, it starts with the same basic concepts but provides context, rationale, guidance, and a greater depth of detail for the fundamental principles of program and project management. This handbook also explores some of the nuances and implications of applying the procedural requirements, for example, how the Agency Baseline Commitment agreement evolves over time as a program or project moves through its life cycle.
Quantum Hilbert matrices and orthogonal polynomials
DEFF Research Database (Denmark)
Andersen, Jørgen Ellegaard; Berg, Christian
2009-01-01
Using the notion of quantum integers associated with a complex number q≠0 , we define the quantum Hilbert matrix and various extensions. They are Hankel matrices corresponding to certain little q -Jacobi polynomials when |q|<1 , and for the special value they are closely related to Hankel matrice...
Hilbert's Grand Hotel with a series twist
Wijeratne, Chanakya; Mamolo, Ami; Zazkis, Rina
2014-08-01
This paper presents a new twist on a familiar paradox, linking seemingly disparate ideas under one roof. Hilbert's Grand Hotel, a paradox which addresses infinite set comparisons is adapted and extended to incorporate ideas from calculus - namely infinite series. We present and resolve several variations, and invite the reader to explore his or her own variations.
Notes on Hilbert and Cauchy Matrices
Czech Academy of Sciences Publication Activity Database
Fiedler, Miroslav
2010-01-01
Roč. 432, č. 1 (2010), s. 351-356 ISSN 0024-3795 Institutional research plan: CEZ:AV0Z10300504 Keywords : Hilbert matrix * Cauchy matrix * combined matrix * AT-property Subject RIV: BA - General Mathematics Impact factor: 1.005, year: 2010
Theory and experiments on Peano and Hilbert curve RFID tags
McVay, John; Hoorfar, Ahmad; Engheta, Nader
2006-05-01
Recently, there has been considerable interest in the area of Radio Frequency Identification (RFID) and Radio Frequency Tagging (RFTAG). This emerging area of interest can be applied for inventory control (commercial) as well as friend/foe identification (military) to name but a few. The current technology can be broken down into two main groups, namely passive and active RFID tags. Utilization of Space-Filling Curve (SFC) geometries, such as the Peano and Hilbert curves, has been recently investigated for use in completely passive RFID applications [1, 2]. In this work, we give an overview of our work on the space-filling curves and the potential for utilizing the electrically small, resonant characteristics of these curves for use in RFID technologies with an emphasis on the challenging issues involved when attempting to tag conductive objects. In particular, we investigate the possible use of these tags in conjunction with high impedance ground-planes made of Hilbert or Peano curve inclusions [3, 4] to develop electrically small RFID tags that may also radiate efficiently, within close proximity of large conductive objects [5].
Commentaries on Hilbert's Basis Theorem | Apine | Science World ...
African Journals Online (AJOL)
The famous basis theorem of David Hilbert is an important theorem in commutative algebra. In particular the Hilbert's basis theorem is the most important source of Noetherian rings which are by far the most important class of rings in commutative algebra. In this paper we have used Hilbert's theorem to examine their unique ...
nth roots with Hilbert-Schmidt defect operator of normal contractions
International Nuclear Information System (INIS)
Duggal, B.P.
1992-08-01
Let T be a normal contraction (on a complex separable Hilbert space H into itself) with an nth root A such that the defect operator D A =(1-A*A) 1/2 is of the Hilbert-Schmidt class C 2 . Then either A is normal or A is similar to a normal contraction. In the case in which T is hyponormal, A n =T and D A is an element of C 2 , A is a ''coupling'' of a contraction similar to a normal contraction and a contraction which is the quasi-affine transform of a unilateral shift. These results are applied to prove a (Putnam-Fuglede type) commutatively theorem for operator valued roots of commutative analytic functions and hyponormal contractions T which have an nth root with Hilbert-Schmidt defect operator. 23 refs
Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors
Directory of Open Access Journals (Sweden)
Jing-Yi Chang
2014-01-01
Full Text Available The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2×2, 4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.
H-SLAM: Rao-Blackwellized Particle Filter SLAM Using Hilbert Maps
Directory of Open Access Journals (Sweden)
Guillem Vallicrosa
2018-05-01
Full Text Available Occupancy Grid maps provide a probabilistic representation of space which is important for a variety of robotic applications like path planning and autonomous manipulation. In this paper, a SLAM (Simultaneous Localization and Mapping framework capable of obtaining this representation online is presented. The H-SLAM (Hilbert Maps SLAM is based on Hilbert Map representation and uses a Particle Filter to represent the robot state. Hilbert Maps offer a continuous probabilistic representation with a small memory footprint. We present a series of experimental results carried both in simulation and with real AUVs (Autonomous Underwater Vehicles. These results demonstrate that our approach is able to represent the environment more consistently while capable of running online.
Management of Service Projects in Support of Space Flight Research
Love, J.
2009-01-01
Goal:To provide human health and performance countermeasures, knowledge, technologies, and tools to enable safe, reliable, and productive human space exploration . [HRP-47051] Specific Objectives: 1) Develop capabilities, necessary countermeasures, and technologies in support of human space exploration, focusing on mitigating the highest risks to human health and performance. 2) Define and improve human spaceflight medical, environmental, and human factors standards. 3) Develop technologies that serve to reduce medical and environmental risks, to reduce human systems resource requirements (mass, volume, power, data, etc.) and to ensure effective human-system integration across exploration systems. 4) Ensure maintenance of Agency core competencies necessary to enable risk reduction in the following areas: A. Space medicine B. Physiological and behavioral effects of long duration spaceflight on the human body C. Space environmental effects, including radiation, on human health and performance D. Space "human factors" [HRP-47051]. Service projects can form integral parts of research-based project-focused programs to provide specialized functions. Traditional/classic project management methodologies and agile approaches are not mutually exclusive paradigms. Agile strategies can be combined with traditional methods and applied in the management of service projects functioning in changing environments. Creative collaborations afford a mechanism for mitigation of constrained resource limitations.
2009 ESMD Space Grant Faculty Project Final Report
Murphy, Gloria; Ghanashyam, Joshi; Guo, Jiang; Conrad, James; Bandyopadhyay, Alak; Cross, William
2009-01-01
The Constellation Program is the medium by which we will maintain a presence in low Earth orbit, return to the moon for further exploration and develop procedures for Mars exploration. The foundation for its presence and success is built by the many individuals that have given of their time, talent and even lives to help propel the mission and objectives of NASA. The Exploration Systems Mission Directorate (ESMD) Faculty Fellows Program is a direct contributor to the success of directorate and Constellation Program objectives. It is through programs such as the ESMD Space Grant program that students are inspired and challenged to achieve the technological heights that will propel us to meet the goals and objectives of ESMD and the Constellation Program. It is through ESMD Space Grant programs that future NASA scientists, engineers, and mathematicians begin to dream of taking America to newer heights of space exploration. The ESMD Space Grant program is to be commended for taking the initiative to develop and implement programs that help solidify the mission of NASA. With the concerted efforts of the Kennedy Space Center educational staff, the 2009 ESMD Space Grant Summer Faculty Fellows Program allowed faculty to become more involved with NASA personnel relating to exploration topics for the senior design projects. The 2009 Project was specifically directed towards NASA's Strategic Educational Outcome 1. In-situ placement of Faculty Fellows at the NASA field Centers was essential; this allowed personal interactions with NASA scientists and engineers. In particular, this was critical to better understanding the NASA problems and begin developing a senior design effort to solve the problems. The Faculty Fellows are pleased that the ESMD Space Grant program is taking interest in developing the Senior Design courses at the university level. These courses are needed to help develop the NASA engineers and scientists of the very near future. It has been a pleasure to be
Another note on the von Neumann alternating projections algorithm
Czech Academy of Sciences Publication Activity Database
Kopecká, Eva; Reich, S.
2010-01-01
Roč. 11, č. 3 (2010), s. 455-460 ISSN 1345-4773 Institutional research plan: CEZ:AV0Z10190503 Keywords : projection * iteration * Hilbert space Subject RIV: BA - General Mathematics Impact factor: 0.738, year: 2010 http://www.ybook.co.jp/online/jncae/vol11/p455.html
The classes of the quasihomogeneous Hilbert schemes of points on the plane
Buryak, A.
2012-01-01
Abstract: In this paper we give a formula for the classes (in the Grothendieck ring of complex quasi-projective varieties) of irreducible components of -quasi-homogeneous Hilbert schemes of points on the plane. We find a new simple geometric interpretation of the -Catalan numbers. Finally, we
HAL/S programmer's guide. [for space shuttle project
Newbold, P. M.; Hotz, R. L.
1974-01-01
The structure and symbology of the HAL/S programming language are described; this language is to be used among the flight software for the space shuttle project. The data declaration, input/output statements, and replace statements are also discussed.
Projected space-time and varying speed of light
International Nuclear Information System (INIS)
Iovane, G.; Bellucci, S.; Benedetto, E.
2008-01-01
In this paper starting from El Naschie's Cantorian space-time and our model of projected Universe, we consider its properties in connection with varying speed of light. A possible way-out of the related problem is provided by the Fantappie group approach
Space Geodesy Project Information and Configuration Management Procedure
Merkowitz, Stephen M.
2016-01-01
This plan defines the Space Geodesy Project (SGP) policies, procedures, and requirements for Information and Configuration Management (CM). This procedure describes a process that is intended to ensure that all proposed and approved technical and programmatic baselines and changes to the SGP hardware, software, support systems, and equipment are documented.
NASA Space Radiation Risk Project: Overview and Recent Results
Blattnig, Steve R.; Chappell, Lori J.; George, Kerry A.; Hada, Megumi; Hu, Shaowen; Kidane, Yared H.; Kim, Myung-Hee Y.; Kovyrshina, Tatiana; Norman, Ryan B.; Nounu, Hatem N.;
2015-01-01
The NASA Space Radiation Risk project is responsible for integrating new experimental and computational results into models to predict risk of cancer and acute radiation syndrome (ARS) for use in mission planning and systems design, as well as current space operations. The project has several parallel efforts focused on proving NASA's radiation risk projection capability in both the near and long term. This presentation will give an overview, with select results from these efforts including the following topics: verification, validation, and streamlining the transition of models to use in decision making; relative biological effectiveness and dose rate effect estimation using a combination of stochastic track structure simulations, DNA damage model calculations and experimental data; ARS model improvements; pathway analysis from gene expression data sets; solar particle event probabilistic exposure calculation including correlated uncertainties for use in design optimization.
Space Projects: Improvements Needed in Selecting Future Projects for Private Financing
1990-01-01
The Office of Management and Budget (OMB) and NASA jointly selected seven projects for commercialization to reduce NASA's fiscal year 1990 budget request and to help achieve the goal of increasing private sector involvement in space. However, the efforts to privately finance these seven projects did not increase the commercial sector's involvement in space to the extent desired. The General Accounting Office (GAO) determined that the projects selected were not a fair test of the potential of increasing commercial investment in space at an acceptable cost to the government, primarily because the projects were not properly screened. That is, neither their suitability for commercialization nor the economic consequences of seeking private financing for them were adequately evaluated before selection. Evaluations and market tests done after selection showed that most of the projects were not viable candidates for private financing. GAO concluded that projects should not be removed from NASA's budget for commercial development until after careful screening has been done to determine whether adequate commercial demand exists, development risks are commercially acceptable and private financing is found or judged to be highly likely, and the cost effectiveness of such a decision is acceptable. Premature removal of projects from NASA's budget ultimately can cause project delays and increased costs when unsuccessful commercialization candidates must be returned to the budget. NASA also needs to ensure appropriate comparisons of government and private financing options for future commercialization projects.
Problem and Project Based Learning in Hybrid Spaces
DEFF Research Database (Denmark)
Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien
2016-01-01
There is a need within networked learning to understand and conceptualise the interplay between digital and physical spaces or what we could term hybrid spaces. Therefore, we discuss a recent study of students from two different programmes who are engaged in long-term, group-based problem...... and project based learning. Based on interviews, workshops and observations of students’ actual group practices in open, shared and flexible spaces in Aalborg University (AAU), we identify and discuss how students incorporate networked and digital technologies into their group work and into the study places...... they create for themselves. We describe how in one of the programmes ‘nomadic’ groups of students used different technologies and spaces for ‘placemaking’. We then show how their experience and approach to collaborative work differs to that of the more static or ‘artisan’ groups of students in the other...
Kiwa, pseud., 1975-
2009-01-01
Aastatel 2004-2008 Pärnus ja aastatel 2006-2008 Tartus tegutsenud Rael Artel Galeriist, mille looja ja moderaator oli Rael Artel. Galerii tegevus lõppes kunstialbumi "Hotell Pärnu : Rael Arel Gallery : Non Profit Project Space 2004-2008 / kontseptsioon ja toimetamine: Rael Artel" ilmumisega 2009. aastal
Project LAUNCH: Bringing Space into Math and Science Classrooms
Fauerbach, M.; Henry, D. P.; Schmidt, D. L.
2005-01-01
Project LAUNCH is a K-12 teacher professional development program, which has been created in collaboration between the Whitaker Center for Science, Mathematics and Technology Education at Florida Gulf Coast University (FGCU), and the Florida Space Research Institute (FSRI). Utilizing Space as the overarching theme it is designed to improve mathematics and science teaching, using inquiry based, hands-on teaching practices, which are aligned with Florida s Sunshine State Standards. Many students are excited about space exploration and it provides a great venue to get them involved in science and mathematics. The scope of Project LAUNCH however goes beyond just providing competency in the subject area, as pedagogy is also an intricate part of the project. Participants were introduced to the Conceptual Change Model (CCM) [1] as a framework to model good teaching practices. As the CCM closely follows what scientists call the scientific process, this teaching method is also useful to actively engage institute participants ,as well as their students, in real science. Project LAUNCH specifically targets teachers in low performing, high socioeconomic schools, where the need for skilled teachers is most critical.
The use of particle accelerators for space projects
International Nuclear Information System (INIS)
Virtanen, Ari
2006-01-01
With the introduction of CMOS technology radiation effects in components became an important issue in satellite and space mission projects. At the end of the cold war, the market of radiation hard (RadHard) components crashed and during the 90's their fabrication practically stopped. The use of 'commercial-off-the-shelf' (COTS) components became more common but required increased evaluation activities at radiation test sites. Component manufacturers and space project engineers were directed towards these test sites, in particular, towards particle accelerators. Many accelerator laboratories developed special beam lines and constructed dedicated test areas for component evaluations. The space environment was simulated at these test sites and components were tested to levels often exceeding mission requirements. In general, space projects environments were predicted in respects to particle mass and energy distributions with the expected fluxes and fluences. In order to validate this information in tests, concepts like stopping power, linear energy transfer, ion penetration ranges etc. have to be understood. The knowledge from the component structure also defines the way of irradiation. For example, the higher ion energies resulting in much deeper ion penetration ranges allow successful reverse side irradiation of thinned Integrated Circuits (ICs). So overall increased demands for radiation testing attracted the European Space Agency (ESA) to the JYFL-accelerator laboratory of the University of Jyvaeskylae, Finland. A contract was signed between ESA and JYFL for the development of a 'High Penetrating Heavy Ion Test Site'. Following one year development, this test site was commissioned in May 2005. This paper addresses the various issues around the JYFL laboratory with its accelerator and radiation effects facility as the focal point in service of component evaluations for the space community
Space Sciences Education and Outreach Project of Moscow State University
Krasotkin, S.
2006-11-01
sergekras@mail.ru The space sciences education and outreach project was initiated at Moscow State University in order to incorporate modern space research into the curriculum popularize the basics of space physics, and enhance public interest in space exploration. On 20 January 2005 the first Russian University Satellite “Universitetskiy-Tatyana” was launched into circular polar orbit (inclination 83 deg., altitude 940-980 km). The onboard scientific complex “Tatyana“, as well as the mission control and information receiving centre, was designed and developed at Moscow State University. The scientific programme of the mission includes measurements of space radiation in different energy channels and Earth UV luminosity and lightning. The current education programme consists of basic multimedia lectures “Life of the Earth in the Solar Atmosphere” and computerized practice exercises “Space Practice” (based on the quasi-real-time data obtained from “Universitetskiy-Tatyana” satellite and other Internet resources). A multimedia lectures LIFE OF EARTH IN THE SOLAR ATMOSPHERE containing the basic information and demonstrations of heliophysics (including Sun structure and solar activity, heliosphere and geophysics, solar-terrestrial connections and solar influence on the Earth’s life) was created for upper high-school and junior university students. For the upper-university students there a dozen special computerized hands-on exercises were created based on the experimental quasi-real-time data obtained from our satellites. Students specializing in space physics from a few Russian universities are involved in scientific work. Educational materials focus on upper high school, middle university and special level for space physics students. Moscow State University is now extending its space science education programme by creating multimedia lectures on remote sensing, space factors and materials study, satellite design and development, etc. The space
A two-step Hilbert transform method for 2D image reconstruction
International Nuclear Information System (INIS)
Noo, Frederic; Clackdoyle, Rolf; Pack, Jed D
2004-01-01
The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fan-beam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained
Girls InSpace project: A new space physics outreach initiative.
Abe Pacini, A.; Tegbaru, D.; Max, A., Sr.
2017-12-01
We present here the concept and state-of-art of the new space physics youth education and outreach initiative called "Girls InSpace project". The project goal is to spread quality scientific information to underrepresented groups, motivate girls in STEM and promote gender equality in the Space Physics area. Initially, the "Girls InSpace project" will be available in two languages (Portuguese and English) aiming to reach out to the youth of Brazil, United States, Nigeria, South Africa, Ethiopia and Angola. Eventually, the material will be translated to French and Spanish, focusing on French-speaking countries in Africa and Latin America. The project spans a collection of four books about a group of young girls and their adventures (always related to the sky and simultaneously introducing earth and space science concepts). Ancillary content such as a webpage, mobile applications and lesson plans are also in development. The books were written by a Space Physicist PhD woman, illustrated by a Brazilian young artist and commented by senior female scientists, creating positive role models for the next generation of girls in STEM. The story lines were drawn around the selected topics of astronomy and space physics, introducing scientific information to the target readers (girls from 8-13 years old) and enhancing their curiosity and critical thinking. The books instill the readers to explore the available extra web-content (with images, videos, interviews with scientists, real space data, coding and deeper scientific information) and game apps (with Virtual Reality components and real space images). Moreover, for teachers K-12, a collection of lesson plans will be made available, aiming to facilitate scientific content discussed in the books and inside classroom environments. Gender bias in STEM reported earlier this year in Nature and based on a study of the American Geophysical Union's member database showed a competitive disadvantage for women in the Earth and Space
Xu, Wenjun; Tang, Chen; Su, Yonggang; Li, Biyuan; Lei, Zhenkun
2018-02-01
In this paper, we propose an image decomposition model Shearlet-Hilbert-L 2 with better performance for denoising in electronic speckle pattern interferometry (ESPI) fringe patterns. In our model, the low-density fringes, high-density fringes, and noise are, respectively, described by shearlet smoothness spaces, adaptive Hilbert space, and L 2 space and processed individually. Because the shearlet transform has superior directional sensitivity, our proposed Shearlet-Hilbert-L 2 model achieves commendable filtering results for various types of ESPI fringe patterns, including uniform density fringe patterns, moderately variable density fringe patterns, and greatly variable density fringe patterns. We evaluate the performance of our proposed Shearlet-Hilbert-L 2 model via application to two computer-simulated and nine experimentally obtained ESPI fringe patterns with various densities and poor quality. Furthermore, we compare our proposed model with windowed Fourier filtering and coherence-enhancing diffusion, both of which are the state-of-the-art methods for ESPI fringe patterns denoising in transform domain and spatial domain, respectively. We also compare our proposed model with the previous image decomposition model BL-Hilbert-L 2 .
Concerning the Hilbert 16th problem
Ilyashenko, Yu; Il'yashenko, Yu
1995-01-01
This book examines qualitative properties of vector fields in the plane, in the spirit of Hilbert's Sixteenth Problem. Two principal topics explored are bifurcations of limit cycles of planar vector fields and desingularization of singular points for individual vector fields and for analytic families of such fields. In addition to presenting important new developments in this area, this book contains an introductory paper which outlines the general context and describes connections between the papers in the volume. The book will appeal to researchers and graduate students working in the qualit
Supporting Multiple Programs and Projects at NASA's Kennedy Space Center
Stewart, Camiren L.
2014-01-01
With the conclusion of the shuttle program in 2011, the National Aeronautics and Space Administration (NASA) had found itself at a crossroads for finding transportation of United States astronauts and experiments to space. The agency would eventually hand off the taxiing of American astronauts to the International Space Station (ISS) that orbits in Low Earth Orbit (LEO) about 210 miles above the earth under the requirements of the Commercial Crew Program (CCP). By privatizing the round trip journey from Earth to the ISS, the space agency has been given the additional time to focus funding and resources to projects that operate beyond LEO; however, adding even more stress to the agency, the premature cancellation of the program that would succeed the Shuttle Program - The Constellation Program (CxP) -it would inevitably delay the goal to travel beyond LEO for a number of years. Enter the Space Launch System (SLS) and the Orion Multipurpose Crew Vehicle (MPCV). Currently, the SLS is under development at NASA's Marshall Spaceflight Center in Huntsville, Alabama, while the Orion Capsule, built by government contractor Lockheed Martin Corporation, has been assembled and is currently under testing at the Kennedy Space Center (KSC) in Florida. In its current vision, SLS will take Orion and its crew to an asteroid that had been captured in an earlier mission in lunar orbit. Additionally, this vehicle and its configuration is NASA's transportation to Mars. Engineers at the Kennedy Space Center are currently working to test the ground systems that will facilitate the launch of Orion and the SLS within its Ground Services Development and Operations (GSDO) Program. Firing Room 1 in the Launch Control Center (LCC) has been refurbished and outfitted to support the SLS Program. In addition, the Spaceport Command and Control System (SCCS) is the underlying control system for monitoring and launching manned launch vehicles. As NASA finds itself at a junction, so does all of its
Hilbert's sixth problem: between the foundations of geometry and the axiomatization of physics.
Corry, Leo
2018-04-28
The sixth of Hilbert's famous 1900 list of 23 problems was a programmatic call for the axiomatization of the physical sciences. It was naturally and organically rooted at the core of Hilbert's conception of what axiomatization is all about. In fact, the axiomatic method which he applied at the turn of the twentieth century in his famous work on the foundations of geometry originated in a preoccupation with foundational questions related with empirical science in general. Indeed, far from a purely formal conception, Hilbert counted geometry among the sciences with strong empirical content, closely related to other branches of physics and deserving a treatment similar to that reserved for the latter. In this treatment, the axiomatization project was meant to play, in his view, a crucial role. Curiously, and contrary to a once-prevalent view, from all the problems in the list, the sixth is the only one that continually engaged Hilbet's efforts over a very long period of time, at least between 1894 and 1932.This article is part of the theme issue 'Hilbert's sixth problem'. © 2018 The Author(s).
Hilbert's sixth problem: between the foundations of geometry and the axiomatization of physics
Corry, Leo
2018-04-01
The sixth of Hilbert's famous 1900 list of 23 problems was a programmatic call for the axiomatization of the physical sciences. It was naturally and organically rooted at the core of Hilbert's conception of what axiomatization is all about. In fact, the axiomatic method which he applied at the turn of the twentieth century in his famous work on the foundations of geometry originated in a preoccupation with foundational questions related with empirical science in general. Indeed, far from a purely formal conception, Hilbert counted geometry among the sciences with strong empirical content, closely related to other branches of physics and deserving a treatment similar to that reserved for the latter. In this treatment, the axiomatization project was meant to play, in his view, a crucial role. Curiously, and contrary to a once-prevalent view, from all the problems in the list, the sixth is the only one that continually engaged Hilbet's efforts over a very long period of time, at least between 1894 and 1932. This article is part of the theme issue `Hilbert's sixth problem'.
MAGDAS Project for Space Weather Research and Application
International Nuclear Information System (INIS)
Yumoto, Kiyohumi
2009-01-01
The Space Environment Research Center (SERC), Kyushu University, is currently deploying a new ground-based magnetometer network of MAGnetic Data Acqusition System (MAGDAS), in cooperation with about 30 organizations in the world, in order to understand the complex Sun-Earth system for space weather research and application. SERC will conducts MAGDAS observation at 50 stations in the Circum-pan Pacific Magnetometer Network (CPMN) region, and FM-CW radar observation along the 210 deg. magnetic meridian (MM) during the IHY/ILWS/CAWSES periods. This project is actively providing the following space weather monitoring:(1) Global 3-dimensional current system to know electromagnetic coupling of the region 1 and 2 field-aligned currents, auroral electrojet current, Sq current, and equatorial electrojet current. (2) Plasma mass density along the 210 deg. MM to understand plasma environment change during space storms. (3) Ionospheric electric field intensity with 10-sec sampling at L = 1.26 to understand how the external electric field penetrates into the equatorial ionosphere.
NASA's In-Space Manufacturing Project: A Roadmap for a Multimaterial Fabrication Laboratory in Space
Prater, Tracie; Werkheiser, Niki; Ledbetter, Frank
2017-01-01
Human space exploration to date has been limited to low Earth orbit and the moon. The International Space Station (ISS) provides a unique opportunity for NASA to partner with private industry for development and demonstration of the technologies needed to support exploration initiatives. One challenge that is critical to sustainable and safer exploration is the ability to manufacture and recycle materials in space. This paper provides an overview of NASA's in-space manufacturing (ISM) project, its past and current activities (2014-2017), and how technologies under development will ultimately culminate in a multimaterial fabrication laboratory ("ISM FabLab") to be deployed on the International Space Station in the early 2020s. ISM is a critical capability for the long endurance missions NASA seeks to undertake in the coming decades. An unanticipated failure that can be adapted for in low earth orbit, through a resupply launch or a return to earth, may instead result in a loss of mission while in transit to Mars. To have a suite of functional ISM capabilities that are compatible with NASA's exploration timeline, ISM must be equipped with the resources necessary to develop these technologies and deploy them for testing prior to the scheduled de-orbit of ISS in 2024. The presentation provides a broad overview of ISM projects activities culminating with the Fabrication Laboratory for ISS. In 2017, the in-space manufacturing project issued a broad agency announcement for this capability. Requirements of the Fabrication Laboratory as stated in the solicitation will be discussed. The FabLab will move NASA and private industry significantly closer to changing historical paradigms for human spaceflight where all materials used in space are launched from earth. While the current ISM FabLab will be tested on ISS, future systems are eventually intended for use in a deep space habitat or transit vehicle. The work of commercial companies funded under NASA's Small Business
Information Theoretic Characterization of Physical Theories with Projective State Space
Zaopo, Marco
2015-08-01
Probabilistic theories are a natural framework to investigate the foundations of quantum theory and possible alternative or deeper theories. In a generic probabilistic theory, states of a physical system are represented as vectors of outcomes probabilities and state spaces are convex cones. In this picture the physics of a given theory is related to the geometric shape of the cone of states. In quantum theory, for instance, the shape of the cone of states corresponds to a projective space over complex numbers. In this paper we investigate geometric constraints on the state space of a generic theory imposed by the following information theoretic requirements: every non completely mixed state of a system is perfectly distinguishable from some other state in a single shot measurement; information capacity of physical systems is conserved under making mixtures of states. These assumptions guarantee that a generic physical system satisfies a natural principle asserting that the more a state of the system is mixed the less information can be stored in the system using that state as logical value. We show that all theories satisfying the above assumptions are such that the shape of their cones of states is that of a projective space over a generic field of numbers. Remarkably, these theories constitute generalizations of quantum theory where superposition principle holds with coefficients pertaining to a generic field of numbers in place of complex numbers. If the field of numbers is trivial and contains only one element we obtain classical theory. This result tells that superposition principle is quite common among probabilistic theories while its absence gives evidence of either classical theory or an implausible theory.
Projective embeddings of homogeneous spaces with small boundary
International Nuclear Information System (INIS)
Arzhantsev, Ivan V
2009-01-01
We study open equivariant projective embeddings of homogeneous spaces such that the complement of the open orbit has codimension at least 2. We establish a criterion for the existence of such an embedding, prove that the set of isomorphism classes of such embeddings is finite, and give a construction of the embeddings in terms of Geometric Invariant Theory. A generalization of Cox's construction and the theory of bunched rings enable us to describe in combinatorial terms the basic geometric properties of embeddings with small boundary
Expected asteroseismic performances with the space project PLATO
Directory of Open Access Journals (Sweden)
Goupil Mariejo
2017-01-01
Full Text Available The PLATO (PLAnetary Transits and Oscillations of star space project will observe about fifty percents of the sky with the main purpose of detecting, confirming and characterizing transiting exoplanets of (superEarth sizes in the habitable zone of solar-like stars. Determining masses, radii and ages of exoplanets require the knowledge the masses, radii and ages of the host stars. We give a brief presentation of the main features of the mission. We then discuss some expected seismic performances of PLATO for characterizing bright solar-like stars, focusing on the challenging determination of accurate/precise stellar ages.
Bobkov, S. G.; Serdin, O. V.; Arkhangelskiy, A. I.; Arkhangelskaja, I. V.; Suchkov, S. I.; Topchiev, N. P.
The problem of electronic component unification at the different levels (circuits, interfaces, hardware and software) used in space industry is considered. The task of computer systems for space purposes developing is discussed by example of scientific data acquisition system for space project GAMMA-400. The basic characteristics of high reliable and fault tolerant chips developed by SRISA RAS for space applicable computational systems are given. To reduce power consumption and enhance data reliability, embedded system interconnect made hierarchical: upper level is Serial RapidIO 1x or 4x with rate transfer 1.25 Gbaud; next level - SpaceWire with rate transfer up to 400 Mbaud and lower level - MIL-STD-1553B and RS232/RS485. The Ethernet 10/100 is technology interface and provided connection with the previously released modules too. Systems interconnection allows creating different redundancy systems. Designers can develop heterogeneous systems that employ the peer-to-peer networking performance of Serial RapidIO using multiprocessor clusters interconnected by SpaceWire.
Holden, Kristina L.; Sandor, Aniko; Thompson, Shelby G.; Kaiser, Mary K.; McCann, Robert S.; Begault, D. R.; Adelstein, B. D.; Beutter, B. R.; Wenzel, E. M.; Godfroy, M.;
2010-01-01
The goal of the Information Presentation Directed Research Project (DRP) is to address design questions related to the presentation of information to the crew. The major areas of work, or subtasks, within this DRP are: 1) Displays, 2) Controls, 3) Electronic Procedures and Fault Management, and 4) Human Performance Modeling. This DRP is a collaborative effort between researchers atJohnson Space Center and Ames Research Center. T
Monopole operators and Hilbert series of Coulomb branches of 3 d = 4 gauge theories
Cremonesi, Stefano; Hanany, Amihay; Zaffaroni, Alberto
2014-01-01
This paper addresses a long standing problem - to identify the chiral ring and moduli space (i.e. as an algebraic variety) on the Coulomb branch of an = 4 superconformal field theory in 2+1 dimensions. Previous techniques involved a computation of the metric on the moduli space and/or mirror symmetry. These methods are limited to sufficiently small moduli spaces, with enough symmetry, or to Higgs branches of sufficiently small gauge theories. We introduce a simple formula for the Hilbert series of the Coulomb branch, which applies to any good or ugly three-dimensional = 4 gauge theory. The formula counts monopole operators which are dressed by classical operators, the Casimir invariants of the residual gauge group that is left unbroken by the magnetic flux. We apply our formula to several classes of gauge theories. Along the way we make various tests of mirror symmetry, successfully comparing the Hilbert series of the Coulomb branch with the Hilbert series of the Higgs branch of the mirror theory.
Matter tensor from the Hilbert variational principle
International Nuclear Information System (INIS)
Pandres, D. Jr.
1976-01-01
We consider the Hilbert variational principle which is conventionally used to derive Einstein's equations for the source-free gravitational field. We show that at least one version of the equivalence principle suggests an alternative way of performing the variation, resulting in a different set of Einstein equations with sources automatically present. This illustrates a technique which may be applied to any theory that is derived from a variational principle and that admits a gauge group. The essential point is that, if one first imposes a gauge condition and then performs the variation, one obtains field equations with source terms which do not appear if one first performs the variation and then imposes the gauge condition. A second illustration is provided by the variational principle conventionally used to derive Maxwell's equations for the source-free electromagnetic field. If one first imposes the Lorentz gauge condition and then performs the variation, one obtains Maxwell's equations with sources present
Noise properties of Hilbert transform evaluation
International Nuclear Information System (INIS)
Pavliček, Pavel; Svak, Vojtěch
2015-01-01
The Hilbert transform is a standard method for the calculation of the envelope and phase of a modulated signal in optical measurement methods. Usually, the intensity of light is converted into an electric signal at a detector. Therefore the actual spatially or temporally sampled signal is always affected by noise. Because the noise values of individual samples are independent, the noise can be considered as white. If the envelope and phase are calculated from the noised signal, they will also be affected by the noise. We calculate the variance and spectral density of both the envelope noise and the phase noise. We determine which parameters influence the variance and spectral density of both the envelope noise and the phase noise. Finally, we determine the influence of the noise on the measurement uncertainty in white-light interferometry and fringe-pattern analysis. (paper)
Report of space experiment project, 'Rad Gene', performed in the International Space Station Kibo
International Nuclear Information System (INIS)
Ohnishi, Takeo; Takahashi, Akihisa; Nagamatsu, Aiko
2010-01-01
This report summarizes results of the project in the title adopted by Japan Aerospace Exploration Agency (JAXA) (in 2000) aiming to elucidate the biological effect of space environment, and contains 3 major parts of the process of the experiment, and of findings by analysis after flight and in radioadaptive response. The process for the experiment includes training of the experimenter crew (Dr. S. Magnus) in JAXA, preparation of samples (frozen cells with normal and mutated p53 genes derived from human lymphoblast TK6) and their transfer to the Space Shuttle Endeavour STS-126 launched on Nov. 15, 2008 (Japanese time) for cell culturing in Feb., 2009. Analyses after flight back to the Kennedy Space Center on Mar. 29, 2009, done on the ground in Japan thereafter include the physical evaluation, confirmation of DNA damage, and phenotypic expression with DNA- and protein-arrays (genes induced for expression of p53-related phenotypes in those cells which were stored frozen in the space, thawed on the ground and then cultured, genes induced for expressing the phenotypes and p53-related proteins expressed in cells cultured in space). Physically, total absorbed dose and dose equivalent are found to be respectively 43.5 mGy and 71.2 mSv (0.5 mSv/day). Interestingly, the biologically estimated dose by DNA-double strand breaks detected by γH2AX staining, 94.5 mSv (0.7 mSv/day), in living, frozen cells in space, is close to the above physical dose. Expression experiments of p53-related phenotypes have revealed that expression of 750 or more genes in 41,000 genes in the array is changed: enhanced or suppressed by space radiation, micro-gravity and/or their mixed effects in space environment. In 642 protein antibodies in the array, 2 proteins are found enhanced and 8, suppressed whereas heat-shock protein is unchanged. Radioadaptive response is the acquisition of radio-resistance to acute exposure by previous irradiation of small dose (window width 20-100 mSv) in normal p53
10 Steps to Building an Architecture for Space Surveillance Projects
Gyorko, E.; Barnhart, E.; Gans, H.
Space surveillance is an increasingly complex task, requiring the coordination of a multitude of organizations and systems, while dealing with competing capabilities, proprietary processes, differing standards, and compliance issues. In order to fully understand space surveillance operations, analysts and engineers need to analyze and break down their operations and systems using what are essentially enterprise architecture processes and techniques. These techniques can be daunting to the first- time architect. This paper provides a summary of simplified steps to analyze a space surveillance system at the enterprise level in order to determine capabilities, services, and systems. These steps form the core of an initial Model-Based Architecting process. For new systems, a well defined, or well architected, space surveillance enterprise leads to an easier transition from model-based architecture to model-based design and provides a greater likelihood that requirements are fulfilled the first time. Both new and existing systems benefit from being easier to manage, and can be sustained more easily using portfolio management techniques, based around capabilities documented in the model repository. The resulting enterprise model helps an architect avoid 1) costly, faulty portfolio decisions; 2) wasteful technology refresh efforts; 3) upgrade and transition nightmares; and 4) non-compliance with DoDAF directives. The Model-Based Architecting steps are based on a process that Harris Corporation has developed from practical experience architecting space surveillance systems and ground systems. Examples are drawn from current work on documenting space situational awareness enterprises. The process is centered on DoDAF 2 and its corresponding meta-model so that terminology is standardized and communicable across any disciplines that know DoDAF architecting, including acquisition, engineering and sustainment disciplines. Each step provides a guideline for the type of data to
Kac's question, planar isospectral pairs and involutions in projective space
International Nuclear Information System (INIS)
Thas, Koen
2006-01-01
In a paper published in Am. Math. Mon. (1966 73 1-23), Kac asked his famous question 'Can one hear the shape of a drum?'. Gordon et al answered this question negatively by constructing planar isospectral pairs in their paper published in Invent. Math. (1992 110 1-22). Only a finite number of pairs have been constructed till now. Further in J. Phys. A: Math. Gen. (2005 38 L477-83), Giraud showed that most of the known examples can be generated from solutions of a certain equation which involves certain involutions of an n-dimensional projective space over some finite field. He then generated all possible solutions when n = 2. In this letter we handle all dimensions, and show that no other examples arise. (letter to the editor)
Empirical mode decomposition and Hilbert transforms for analysis of oil-film interferograms
International Nuclear Information System (INIS)
Chauhan, Kapil; Ng, Henry C H; Marusic, Ivan
2010-01-01
Oil-film interferometry is rapidly becoming the preferred method for direct measurement of wall shear stress in studies of wall-bounded turbulent flows. Although being widely accepted as the most accurate technique, it does have inherent measurement uncertainties, one of which is associated with determining the fringe spacing. This is the focus of this paper. Conventional analysis methods involve a certain level of user input and thus some subjectivity. In this paper, we consider empirical mode decomposition (EMD) and the Hilbert transform as an alternative tool for analyzing oil-film interferograms. In contrast to the commonly used Fourier-based techniques, this new method is less subjective and, as it is based on the Hilbert transform, is superior for treating amplitude and frequency modulated data. This makes it particularly robust to wide differences in the quality of interferograms
UNH Project SMART 2017: Space Science for High School Students
Smith, C. W.; Broad, L.; Goelzer, S.; Levergood, R.; Lugaz, N.; Moebius, E.
2017-12-01
Every summer for the past 26 years the University of New Hampshire (UNH) has run a month-long, residential outreach program for high school students considering careers in mathematics, science, or engineering. Space science is one of the modules. Students work directly with UNH faculty performing original work with real spacecraft data and hardware and present the results of that effort at the end of the program. This year the student research projects used data from the Messenger, STEREO, and Triana missions. In addition, the students build and fly a high-altitude balloon payload with instruments of their own construction. Students learn circuit design and construction, microcontroller programming, and core atmospheric and space science along with fundamental concepts in space physics and engineering. Our payload design has evolved significantly since the first flight of a simple rectangular box and now involves a stable descent vehicle that does not require a parachute. Our flight hardware includes an on-board flight control computer, in-flight autonomous control and data acquisition of multiple student-built instruments, and real-time camera images sent to ground. This year we developed, built and flew a successful line cutter based on GPS location information that prevents our payload from falling into the ocean while also separating the payload from the balloon remains for a cleaner descent. We will describe that new line cutter design and implementation along with the shielded Geiger counters that we flew as part of our cosmic ray air shower experiment. This is a program that can be used as a model for other schools to follow and that high schools can initiate. More information can be found at .
Schroedinger--Dirac spaces of entire functions
International Nuclear Information System (INIS)
De Branges, L.
1977-01-01
A study is made of some Hilbert spaces of entire function which appear in the quantum mechanical theory of the hydrogen atoms. These spaces are examples in the theory of Hilbert spaces whose elements are entire functions and which have certain given properties. 1 reference
Delusional Cities: beyond the projected identity of urban space
Directory of Open Access Journals (Sweden)
Ruxandra Puşcaşu
2014-06-01
Full Text Available Narratives intermediate the perception of place along with image, which is according to Burgin an integrated part of the “cultural promotion” and “city marketing” process (1996. In this manner, social and cultural meanings of place are re-modelled with relation to significant events or icons and, therefore, a more enchanting and attractive portrait of the city is promoted to be explored and experienced. Cities introduce a representation based on an idealised projection of their reality while exposing “key attractions”. As such, their projected image may have a greater influence than the reality in shaping the views of visitors, investors or even residents. The advertised portrait of the city has the power to reshape its appearance, as it is usually perceived, into a misleading one. Such chimera physiognomies of cities are often, if not in every case, presented in a captivating manner. This paper relies on the remarkable quality of narratives to go beyond the fabricated image of the city and to engage with the real identity of place while profiling the visual and experiential layout of the city. The investigation focus is primarily placed upon the mode in which historical and spatial humanities theoretical knowledge along with narratives of place can enrich the morphological study. The interaction between architecture, people, and narrative codes in the city spaces and on the way spatial layout relates to them is therefore explored. Particular emphasis is laid towards the manner in which spoken narratives of place can provide us with perceptual tools to shape the complexity of the urban phenomena and its cultural meaning. In doing so, we can start overlaying memories that are situated “beyond the city” and as such are brought to light and merged with maps of “lived experiences”.
International Space Station Medical Projects - Full Services to Mars
Pietrzyk, R. A.; Primeaux, L. L.; Wood, S. J.; Vessay, W. B.; Platts, S. H.
2018-01-01
The International Space Station Medical Projects (ISSMP) Element provides planning, integration, and implementation services for HRP research studies for both spaceflight and flight analog research. Through the implementation of these two efforts, ISSMP offers an innovative way of guiding research decisions to meet the unique challenges of understanding the human risks to space exploration. Flight services provided by ISSMP include leading informed consent briefings, developing and validating in-flight crew procedures, providing ISS crew and ground-controller training, real-time experiment monitoring, on-orbit experiment and hardware operations and facilitating data transfer to investigators. For analog studies at the NASA Human Exploration Research Analog (HERA), the ISSMP team provides subject recruitment and screening, science requirements integration, data collection schedules, data sharing agreements, mission scenarios and facilities to support investigators. The ISSMP also serves as the HRP interface to external analog providers including the :envihab bed rest facility (Cologne, Germany), NEK isolation chamber (Moscow, Russia) and the Antarctica research stations. Investigators working in either spaceflight or analog environments requires a coordinated effort between NASA and the investigators. The interdisciplinary nature of both flight and analog research requires investigators to be aware of concurrent research studies and take into account potential confounding factors that may impact their research objectives. Investigators must define clear research requirements, participate in Investigator Working Group meetings, obtain human use approvals, and provide study-specific training, sample and data collection and procedures all while adhering to schedule deadlines. These science requirements define the technical, functional and performance operations to meet the research objectives. The ISSMP maintains an expert team of professionals with the knowledge and
Astrium suborbital spaceplane project: Demand analysis of suborbital space tourism
Le Goff, Thierry; Moreau, Antoine
2013-12-01
ASTRIUM is preparing the development of a safe and passenger friendly Suborbital Spaceplane, taking off and landing from a standard runway, powered by turbofans and using a rocket engine of proven design to reach 100 km altitude. This vehicle will be able to carry paying passengers to the edge of space and return them safely to their starting point. As a very new potentially adjacent B2C market, Astrium had decided at the beginning of this project to first conduct a full market analysis with the support of a worldwide survey based Research Company (IPSOS) in order to assess reality and credibility of this market. Two campaigns have been done, the first one in 2007 and the second one in 2010 after the international financial crisis. Last one has been also the opportunity to optimize quality of models by focusing in Asia region. This article describes the methodology used for this survey and unveils some results in term of size of this market and typology of the customers.
Overview of some projects of SNPS for global space communication
International Nuclear Information System (INIS)
Ivanov, E.; Ghitajkin, V.; Ionkin, V.; Dubinin, A.; Pyshko, A.
2000-01-01
Modem concepts of the application of power technology in space believe in using an onboard source of energy for maintenance of self-transportation of the vehicle into working geosynchronous orbit (GEO). This can result in reduction of the cost of all installation and the number of rocket starts. There we present several conceptual projects of nuclear power installations. Power units developed with, IPPE's participation are intended for long term supply of electricity to the vehicle in GEO and to maintain self-transportation of capabilities. Considered units include a tiny, fast neutron nuclear reactor, radiation shield, control system, cooling system (radiator) and power conversion system. Additionally, they must also include a rocket engine to maintain the dual-mode regime. This may be an electric-stationary ion jet (with Xe as working body) and a thermal engine such as hybrid or NRE. There are three more prospective systems as follows: (a) gas cooled nuclear reactor with hybrid thermal engine and machine power converter; (b) nuclear reactor cooled by liquid metal and with a thermoelectric power generating system; (c) nuclear reactor with Li cooling and a thermionic and thermoelectric power generator on board. All considered schemes have two thermal circuits and use thermal pipes in the radiator. Two final concepts are based on a Xe electric jet; these differ from first concept by having a lower working body mass but a longer transportation period from basic orbit into GEO. (authors)
In-Space Manufacturing Project (prior to FY15: Additive Manufacturing Technology Development)
National Aeronautics and Space Administration — The In-Space Manufacturing (ISM) project is responsible for developing the manufacturing capabilities that will provide on-demand, sustainable operations during NASA...
Moduli of mathematical instanton vector bundles with odd c2 on projective space
International Nuclear Information System (INIS)
Tikhomirov, Aleksandr S
2012-01-01
We study the moduli space I n of mathematical instanton vector bundles of rank 2 with second Chern class n≥1 on the projective space P 3 , and prove the irreducibility of I n for arbitrary odd n≥1.
1976-01-01
Contractural requirements, project planning, equipment specifications, and technical data for space shuttle biological experiment payloads are presented. Topics discussed are: (1) urine collection and processing on the space shuttle, (2) space processing of biochemical and biomedical materials, (3) mission simulations, and (4) biomedical equipment.
Directory of Open Access Journals (Sweden)
Sergey Krichevsky
2018-02-01
Full Text Available The 60th anniversary of the Space Age is an important intermediate finishing point on the way of a man and the whole humanity to space. Along with the outstanding achievements, there are a number of challenges and contradictions in space exploration due to the aggravation of the global crisis on Earth, low efficiency and the backlog of space research in the transition to a new technology based reality and clean technologies. Both the international astronautics and the space exploration area nowadays face difficulties in choosing a new paradigm and a development strategy that is becoming even more complicated due to the current unstable and turbulent situation on Earth. The article reveals the optimistic scenario of further space exploration, as well as the methodological and practical aspects of new projects and technologies. The periodization of the Space Age history has been conducted. It has been also proposed a new classification of the “space” phenomenon due to concretizing the concept of “global” in the form of a three-scale structure encompassing the following levels: 1 planetary global; 2 super global; 3 universally global. The notion of “super global space exploration project” has been introduced. The concept of further space exploration is proposed, which includes four interrelated super global projects:1 Earth Protection System from Asteroid and Comet Threat; 2 Moon Exploration; 3 Mars Exploration; 4 Cosmic Humanity. Since the humanity is embarking on the practical implementation of these super global projects, it is urgent to make a transition towards a new technology based order, as well as up-to-date technologies. A couple of ecological projects and space exploration technologies of the 20th and 21st centuries have been exemplified and analyzed. It has been also worked out the list of new environmentally friendly space technologies and projects. The research makes an emphasis upon a great potential of clean and green
The RMI Space Weather and Navigation Systems (SWANS) Project
Warnant, Rene; Lejeune, Sandrine; Wautelet, Gilles; Spits, Justine; Stegen, Koen; Stankov, Stan
The SWANS (Space Weather and Navigation Systems) research and development project (http://swans.meteo.be) is an initiative of the Royal Meteorological Institute (RMI) under the auspices of the Belgian Solar-Terrestrial Centre of Excellence (STCE). The RMI SWANS objectives are: research on space weather and its effects on GNSS applications; permanent mon-itoring of the local/regional geomagnetic and ionospheric activity; and development/operation of relevant nowcast, forecast, and alert services to help professional GNSS/GALILEO users in mitigating space weather effects. Several SWANS developments have already been implemented and available for use. The K-LOGIC (Local Operational Geomagnetic Index K Calculation) system is a nowcast system based on a fully automated computer procedure for real-time digital magnetogram data acquisition, data screening, and calculating the local geomagnetic K index. Simultaneously, the planetary Kp index is estimated from solar wind measurements, thus adding to the service reliability and providing forecast capabilities as well. A novel hybrid empirical model, based on these ground-and space-based observations, has been implemented for nowcasting and forecasting the geomagnetic index, issuing also alerts whenever storm-level activity is indicated. A very important feature of the nowcast/forecast system is the strict control on the data input and processing, allowing for an immediate assessment of the output quality. The purpose of the LIEDR (Local Ionospheric Electron Density Reconstruction) system is to acquire and process data from simultaneous ground-based GNSS TEC and digital ionosonde measurements, and subsequently to deduce the vertical electron density distribution. A key module is the real-time estimation of the ionospheric slab thickness, offering additional infor-mation on the local ionospheric dynamics. The RTK (Real Time Kinematic) status mapping provides a quick look at the small-scale ionospheric effects on the RTK
High Efficiency Space Power Systems Project Advanced Space-Rated Batteries
Reid, Concha M.
2011-01-01
Case Western Reserve University (CWRU) has an agreement with China National Offshore Oil Corporation New Energy Investment Company, Ltd. (CNOOC), under the United States-China EcoPartnerships Framework, to create a bi-national entity seeking to develop technically feasible and economically viable solutions to energy and environmental issues. Advanced batteries have been identified as one of the initial areas targeted for collaborations. CWRU invited NASA Glenn Research Center (GRC) personnel from the Electrochemistry Branch to CWRU to discuss various aspects of advanced battery development as they might apply to this partnership. Topics discussed included: the process for the selection of a battery chemistry; the establishment of an integrated development program; project management/technical interactions; new technology developments; and synergies between batteries for automotive and space operations. Additional collaborations between CWRU and NASA GRC's Electrochemistry Branch were also discussed.
Nature's Way of Making Audacious Space Projects Viable
Metzger, Philip T.
2011-01-01
Building a starship within the next 100 years is an audacious goal. To be successful, we need sustained funding that may be difficult to maintain in the face of economic challenges that are poised to arise during these next 100 years. Our species' civilization has only recently reached the classification as (approximately) Type-I on the Kardashev scale; that is, we have spread out from one small locality to become a global species mastering the energy and resources of an entire planet. In the process we discovered the profound truth that the two-dimensional surface of our world is not flat, but has positive curvature and is closed so that its area and resources are finite. It should come as no surprise to a Type I civilization when its planet's resources dWindle; how could they not? Yet we have gone year by year, government by government, making little investment for the time when civilization becomes violent in the unwelcome contractions that must follow, when we are forced too late into the inevitable choice: to remain and diminish on an unhappy world; or to expand into the only dimension remaining perpendicularly outward from the surface into space. Then some day we may become a Type-II civilization, mastering the resources of an entire solar system. Our species cannot continue as we have on this planet for another 100 years. Doubtless it falls on us today, the very time we intended to start building a starship, to make the late choice. We wished this century to be filled with enlightenment and adventure; it could be an age of desperation and war. What a time to begin an audacious project in space! How will we maintain consistent funding for the next 100 years? Fortunately, saving a civilization, mastering a solar system, and doing other great things like building starships amount to mostly the same set of tasks. Recognizing what we must be about during the next 100 years will make it possible to do them all.
On projective invariants based on non-linear connections in a Finsler space I
International Nuclear Information System (INIS)
Rastogi, S.C.
1986-05-01
The projective transformations based on linear connections in a Finsler space have been studied by Berwald, Misra, Szabo, Matsumoto, Fukai and Yamada, Rastogi and others. In almost all these papers the emphasis has been on studying Finsler spaces of scalar curvature, Finsler spaces of constant curvature and Finsler spaces of zero curvature with the help of projective curvature tensors of Weyl and Douglas. In 1981, the author studied projective transformation in a Finsler space based on non-linear connections and obtained certain projective invariants. The aim of the present paper is to study Finsler spaces of scalar curvature, constant curvature and zero curvature with the help of non-linear connections and projective invariants obtained from non-linear connections. (author)
Introduction to partial differential equations and Hilbert space methods
Gustafson, Karl E
1997-01-01
Easy-to-use text examines principal method of solving partial differential equations, 1st-order systems, computation methods, and much more. Over 600 exercises, with answers for many. Ideal for a 1-semester or full-year course.
On Nyman, Beurling and Baez-Duarte's Hilbert space reformulation ...
Indian Academy of Sciences (India)
an expert is usually defined to be a person who has the relevant piece of information.) Moreover, the main result in [2] is not the ... Recall that Riemann's zeta function is the analytic function defined on the half-plane {σ > 1} by the absolutely ... Our intention in this article is to point out that the entire gamut of these results is ...
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
Kalcic, Maria; Turowski, Mark; Hall, Callie
2010-01-01
Presentation topics include: importance of salinity of coastal waters, habitat switching algorithm, habitat switching module, salinity estimates from Landsat for Sabine Calcasieu Basin, percent of time inundated in 2006, salinity data, prototyping the system, system as packaged for field tests, salinity probe and casing, opening for water flow, cellular antenna used to transmit data, preparing to launch, system is launched in the Pearl River at Stennis Space Center, data are transmitted to Twitter by cell phone modem every 15 minutes, Google spreadsheet I used to import the data from the Twitter feed and to compute salinity (from conductivity) and display charts of salinity and temperature, results are uploaded to NASA's Applied Science and Technology Project Office Webpage.
Improved specimen reconstruction by Hilbert phase contrast tomography.
Barton, Bastian; Joos, Friederike; Schröder, Rasmus R
2008-11-01
The low signal-to-noise ratio (SNR) in images of unstained specimens recorded with conventional defocus phase contrast makes it difficult to interpret 3D volumes obtained by electron tomography (ET). The high defocus applied for conventional tilt series generates some phase contrast but leads to an incomplete transfer of object information. For tomography of biological weak-phase objects, optimal image contrast and subsequently an optimized SNR are essential for the reconstruction of details such as macromolecular assemblies at molecular resolution. The problem of low contrast can be partially solved by applying a Hilbert phase plate positioned in the back focal plane (BFP) of the objective lens while recording images in Gaussian focus. Images recorded with the Hilbert phase plate provide optimized positive phase contrast at low spatial frequencies, and the contrast transfer in principle extends to the information limit of the microscope. The antisymmetric Hilbert phase contrast (HPC) can be numerically converted into isotropic contrast, which is equivalent to the contrast obtained by a Zernike phase plate. Thus, in-focus HPC provides optimal structure factor information without limiting effects of the transfer function. In this article, we present the first electron tomograms of biological specimens reconstructed from Hilbert phase plate image series. We outline the technical implementation of the phase plate and demonstrate that the technique is routinely applicable for tomography. A comparison between conventional defocus tomograms and in-focus HPC volumes shows an enhanced SNR and an improved specimen visibility for in-focus Hilbert tomography.
Diagonalization of a self-adjoint operator acting on a Hilbert module
Directory of Open Access Journals (Sweden)
Parfeny P. Saworotnow
1985-01-01
Full Text Available For each bounded self-adjoint operator T on a Hilbert module H over an H*-algebra A there exists a locally compact space m and a certain A-valued measure μ such that H is isomorphic to L2(μ⊗A and T corresponds to a multiplication with a continuous function. There is a similar result for a commuting family of normal operators. A consequence for this result is a representation theorem for generalized stationary processes.
Better library and learning space projects, trends, ideas
Watson, Les
2014-01-01
What are the most important things a 21st-century library should do with its space? This title includes chapters that address this critical question, capturing the insights and practical ideas of international librarians, educators and designers to offer you a 'creative resource bank' that helps to transform your library and learning spaces.
Overview of some projects of SNPS for global space communication
International Nuclear Information System (INIS)
Ivanov, E.; Ghitaykin, V.; Ionkin, V.; Dubinin, A.; Pyshko, A.
2001-01-01
In this presentation we focused on three variants of prospective concepts of SNPS. They are intended to solve tasks of global space communication (GSC) as nearest future tasks in space. Modern concepts of the application of power technology in space believe in using an onboard source of energy for maintenance of self-transportation of the vehicle into geostationary orbit (GSO). There are three more prospective systems as follows: gas cooled nuclear reactor with hybrid thermal engine and machine power converter; nuclear reactor cooled by liquid metal and with a thermoelectric power generating system; nuclear reactor with Li cooling and a thermionic and thermoelectric power generator on board. The choice of a concept must fit strong requirements such as: space nuclear power unit is aimed to be used in a powerful mission; space power unit must be able to maintain the dual - mode regime of vehicle operation (self - transportation and long life in geosynchronous orbit [GEO]); nuclear rector of unit must be safety and it must be designed in such a way that it will ensure minimum size of the complete system; the elements of the considered technology can be used for the creation of NPPI and with other sources of heat (for example, radioisotope); the degree of technical and technological readiness of units of the thermal and power circuit of installation is estimated to be high and is defined by a number of technological developments in air, space and nuclear branches; nuclear reactor and heat transfer equipment should work in a normal mode, which can be very reliably confirmed for other high-temperature nuclear systems. Considering these concepts we practically consider one of possible strategy of developing of complex system of nuclear power engineering. It is the strategy of step-by-step development of space engineering with real application of them in commercial, scientific and other powerful missions in the nearest and deep space. As starting point of this activity is
Frames and outer frames for Hilbert C^*-modules
Arambašić, Ljiljana; Bakić, Damir
2015-01-01
The goal of the present paper is to extend the theory of frames for countably generated Hilbert $C^*$-modules over arbitrary $C^*$-algebras. In investigating the non-unital case we introduce the concept of outer frame as a sequence in the multiplier module $M(X)$ that has the standard frame property when applied to elements of the ambient module $X$. Given a Hilbert $\\A$-module $X$, we prove that there is a bijective correspondence of the set of all adjointable surjections from the generalize...
Measurement of vibration mode shape by using Hilbert transform
International Nuclear Information System (INIS)
Kang, Min Sig
2001-01-01
This paper concerns on modal analysis of mechanical structures by using a continuous scanning laser Doppler vibrometer. In modal analysis the Hilbert transform based approach is superior to the Fourier transform based approach because of its fine accuracy and its flexible experimental settings. In this paper the Hilbert transform based approach is extended to measure area mode shape data of a structure by simply modifying the scanning pattern ranging the entire surface of the structure. The effectiveness of this proposed method is illustrated along with results of numerical simulation for a rectangular plate
Projective unitary-antiunitary representations of the Shubnikov space groups
International Nuclear Information System (INIS)
Broek, P.M. van den.
1979-01-01
Some mathematical aspects of the symmetry of a physical system in quantum mechanics are examined with special emphasis on the symmetry groups of charged particles in crystalline solids, the Shuknikov space groups. (Auth.)
Advanced Life Support Project: Crop Experiments at Kennedy Space Center
Sager, John C.; Stutte, Gary W.; Wheeler, Raymond M.; Yorio, Neil
2004-01-01
Crop production systems provide bioregenerative technologies to complement human crew life support requirements on long duration space missions. Kennedy Space Center has lead NASA's research on crop production systems that produce high value fresh foods, provide atmospheric regeneration, and perform water processing. As the emphasis on early missions to Mars has developed, our research focused on modular, scalable systems for transit missions, which can be developed into larger autonomous, bioregenerative systems for subsequent surface missions. Components of these scalable systems will include development of efficient light generating or collecting technologies, low mass plant growth chambers, and capability to operate in the high energy background radiation and reduced atmospheric pressures of space. These systems will be integrated with air, water, and thermal subsystems in an operational system. Extensive crop testing has been done for both staple and salad crops, but limited data is available on specific cultivar selection and breadboard testing to meet nominal Mars mission profiles of a 500-600 day surface mission. The recent research emphasis at Kennedy Space Center has shifted from staple crops, such as wheat, soybean and rice, toward short cycle salad crops such as lettuce, onion, radish, tomato, pepper, and strawberry. This paper will review the results of crop experiments to support the Exploration Initiative and the ongoing development of supporting technologies, and give an overview of capabilities of the newly opened Space Life Science (SLS) Lab at Kennedy Space Center. The 9662 square m (104,000 square ft) SLS Lab was built by the State of Florida and supports all NASA research that had been performed in Hanger-L. In addition to NASA research, the SLS Lab houses the Florida Space Research Institute (FSRI), responsible for co-managing the facility, and the University of Florida (UF) has established the Space Agriculture and Biotechnology Research and
The Social and Economic Impacts of Space Weather (US Project)
Pulkkinen, A. A.; Bisi, M. M.; Webb, D. F.; Oughton, E. J.; Worman, S. L.; Taylor, S. M.; Onsager, T. G.; Adkins, J. E.; Baker, D. N.; Forbes, K. F.; Basoli, D.; Griot, O.
2017-12-01
The National Space Weather Action Plan calls for new research into the social and economic impacts of space weather and for the development of quantitative estimates of potential costs. In response to this call, NOAA's Space Weather Prediction Center (SWPC) and Abt Associates are working together to identify, describe, and quantify the impact of space weather to U.S. interests. This study covers impacts resulting from both moderate and severe space weather events across four technological sectors: Electric power, commercial aviation, satellites, and Global Navigation Satellite System (GNSS) users. It captures the full range of potential impacts, identified from an extensive literature review and from additional conversations with more than 50 sector stakeholders of diverse expertise from engineering to operations to end users. We organize and discuss our findings in terms of five broad but interrelated impact categories including Defensive Investments, Mitigating Actions, Asset Damages, Service Interruptions, and Health Effects. We also present simple, tractable estimates of the potential costs where we focused on quantifying a subset of all identified impacts that are apt to be largest and are also most plausible during moderate and more severe space weather scenarios. We hope that our systematic exploration of the social and economic impacts provides a foundation for the future work that is critical for designing technologies, developing procedures, and implementing policies that can effectively reduce our known and evolving vulnerabilities to this natural hazard.
Construction of spaces of kinematic quantum states for field theories via projective techniques
International Nuclear Information System (INIS)
Okołów, Andrzej
2013-01-01
We present a method of constructing a space of quantum states for a field theory: given phase space of a theory, we define a family of physical systems each possessing a finite number of degrees of freedom, next we define a space of quantum states for each finite system, finally using projective techniques we organize all these spaces into a space of quantum states which corresponds to the original phase space. This construction is kinematic in this sense that it bases merely on the structure of the phase space of a theory and does not take into account possible constraints on the space. The construction is a generalization of a construction by Kijowski—the latter one is limited to theories of linear phase spaces, while the former one is free of this limitation. The method presented in this paper enables to construct a space of quantum states for the teleparallel equivalent of general relativity. (paper)
Tang, Shaojie; Yang, Yi; Tang, Xiangyang
2012-01-01
Interior tomography problem can be solved using the so-called differentiated backprojection-projection onto convex sets (DBP-POCS) method, which requires a priori knowledge within a small area interior to the region of interest (ROI) to be imaged. In theory, the small area wherein the a priori knowledge is required can be in any shape, but most of the existing implementations carry out the Hilbert filtering either horizontally or vertically, leading to a vertical or horizontal strip that may be across a large area in the object. In this work, we implement a practical DBP-POCS method with radial Hilbert filtering and thus the small area with the a priori knowledge can be roughly round (e.g., a sinus or ventricles among other anatomic cavities in human or animal body). We also conduct an experimental evaluation to verify the performance of this practical implementation. We specifically re-derive the reconstruction formula in the DBP-POCS fashion with radial Hilbert filtering to assure that only a small round area with the a priori knowledge be needed (namely radial DBP-POCS method henceforth). The performance of the practical DBP-POCS method with radial Hilbert filtering and a priori knowledge in a small round area is evaluated with projection data of the standard and modified Shepp-Logan phantoms simulated by computer, followed by a verification using real projection data acquired by a computed tomography (CT) scanner. The preliminary performance study shows that, if a priori knowledge in a small round area is available, the radial DBP-POCS method can solve the interior tomography problem in a more practical way at high accuracy. In comparison to the implementations of DBP-POCS method demanding the a priori knowledge in horizontal or vertical strip, the radial DBP-POCS method requires the a priori knowledge within a small round area only. Such a relaxed requirement on the availability of a priori knowledge can be readily met in practice, because a variety of small
Projecting Homes: Domestic Spaces in Three Filipino Films
Directory of Open Access Journals (Sweden)
Tito R. Quiling Jr.
2013-12-01
Full Text Available The house is a fundamental space for a character’s consciousness, and this structure is a familiar image in Filipino f ilms. This particular space as a setting in which the narrative and the characters are able to move in, is essential. This paper analyzes the influence of domestic spaces and the characteristics of home, which correspond to the characters’ consciousness and the narrative. These are presented in the selected films: Oro, Plata, Mata (1982 by Peque Gallaga, “Hellow, Soldier,” the second episode in Lino Brocka’s Tatlo, Dalawa, Isa (1975, and Kisapmata (1981 by Mike De Leon. The method for assessment consists of three parts: (1 the background in which the films are set, (2 the influence of the house using Gaston Bachelard’s notion of the house in The Poetics of Space (1994 as a framework, (3 and the behavior of the characters as portrayed in the films. The significance of domestic spaces to a character’s experience is illustrated in the selected texts.
Generalized noncommutative Hardy and Hardy-Hilbert type inequalities
DEFF Research Database (Denmark)
Hansen, Frank; Krulic, Kristina; Pecaric, Josip
2010-01-01
We extend and unify several Hardy type inequalities to functions whose values are positive semi-definite operators. In particular, our methods lead to the operator versions of Hardy-Hilbert's and Godunova's inequalities. While classical Hardy type inequalities hold for parameter values p > 1, it ...
[Earth and Space Sciences Project Services for NASA HPCC
Merkey, Phillip
2002-01-01
This grant supported the effort to characterize the problem domain of the Earth Science Technology Office's Computational Technologies Project, to engage the Beowulf Cluster Computing Community as well as the High Performance Computing Research Community so that we can predict the applicability of said technologies to the scientific community represented by the CT project and formulate long term strategies to provide the computational resources necessary to attain the anticipated scientific objectives of the CT project. Specifically, the goal of the evaluation effort is to use the information gathered over the course of the Round-3 investigations to quantify the trends in scientific expectations, the algorithmic requirements and capabilities of high-performance computers to satisfy this anticipated need.
International Nuclear Information System (INIS)
Sitaramayya, M.
1993-11-01
After a brief review of the geometry of Moishezon spaces, their relation with l-convex spaces and a reasonable and up to date understanding of the obstructions for projectivity of Moishezon objects both in singular and non-singular case is given. The geometry of l-convex manifolds and with l-dimensional exceptional set is studied and some problems and conjectures are stated. The tools of cohomology vanishing theorems important for the subject are briefly sketched. Compactifications of C 3 and Stein spaces are finally outlined. given. 111 refs, 2 figs
Biodigester Feasibility and Design for Space and Earth Project
Terrier, Douglas; Clayton, Ronald; Shutts, Stacy (Principal Investigator); Bacon, John; Ewert, Michael; Paul, Thomas
2016-01-01
Biodigesters harness and utilize byproducts, and are a valuable technology for waste conversion and advanced exploration closed loops targets (6.1.a-E), including that of human waste. On Mars and at JSC, this could lead to growing food and to more sustainable uses of waste. It is critical to understand biogas generation rates, odor management of the effluent, and nutrient viability. Improved efficiency and reliance on this renewable energy source can become feasible for deep space missions.
Advanced Solid State Lighting for AES Deep Space Hab Project
Holbert, Eirik
2015-01-01
The advanced Solid State Lighting (SSL) assemblies augmented 2nd generation modules under development for the Advanced Exploration Systems Deep Space Habitat in using color therapy to synchronize crew circadian rhythms. Current RGB LED technology does not produce sufficient brightness to adequately address general lighting in addition to color therapy. The intent is to address both through a mix of white and RGB LEDs designing for fully addressable alertness/relaxation levels as well as more dramatic circadian shifts.
Classification of the spaces Cp*(X) within the Borel-Wadge hierarchy for a projective space X
Czech Academy of Sciences Publication Activity Database
Doležal, Martin; Vejnar, B.
2015-01-01
Roč. 183, March (2015), s. 11-17 ISSN 0166-8641 Institutional support: RVO:67985840 Keywords : function spaces * pointwise convergence * projective determinacy Subject RIV: BA - General Mathematics Impact factor: 0.493, year: 2015 http://www.sciencedirect.com/science/article/pii/S0166864114004854
Functional equations in matrix normed spaces
Indian Academy of Sciences (India)
The abstract characterization given for linear spaces of bounded Hilbert space operators in terms of ... effect on operator algebra theory (see [12]). .... of functional equations for the proof of new fixed point theorems with applications. By.
Fall 2015 NASA Internship, and Space Radiation Health Project
Patience, Luke
2015-01-01
This fall, I was fortunate enough to have been able to participate in an internship at NASA's Lyndon B. Johnson Space Center. I was placed into the Human Health & Performance Directorate, where I was specifically tasked to work with Dr. Zarana Patel, researching the impacts of cosmic level radiation on human cells. Using different laboratory techniques, we were able to examine the cells to see if any damage had been done due to radiation exposure, and if so, how much damage was done. Cell culture samples were exposed at different doses, and fixed at different time points so that we could accumulate a large pool of quantifiable data. After examining quantifiable results relative to the impacts of space radiation on the human body at the cellular and chromosomal level, researchers can defer to different areas of the space program that have to do with astronaut safety, and research and development (extravehicular mobility unit construction, vehicle design and construction, etc.). This experience has been very eye-opening, and I was able to learn quite a bit. I learned some new laboratory techniques, and I did my best to try and learn new ways to balance such a hectic work and school schedule. I also learned some very intimate thing about working at NASA; I learned that far more people want to watch you succeed, rather than watch you fail, and I also learned that this is a place that is alive with innovators and explorers - people who have a sole purpose of exploring space for the betterment of humanity, and not for any other reason. It's truly inspiring. All of these experiences during my internship have impacted me in a really profound way, so much that my educational and career goals are completely different than when I started. I started out as a biotechnology major, and I discovered recently toward the end of the internship, that I don't want to work in a lab, nor was I as enthralled by biological life sciences as a believed myself to be. Taking that all into
Space Object and Light Attribute Rendering (SOLAR) Projection System
2017-05-08
depicting the proposed SOLAR projection system. The installation process is shown in Fig. 3. SOLAR system comprises of a dome that houses Digitairum’s...imaging process. A fiberglass dome system was erected to make the SOLAR system a self contained facility. Calibration process was carried out to register...Separate software solutions were implemented to model the light transport processes involved in the imaging process. A fiberglass dome system was erected to
The effect of redshift-space distortions on projected 2-pt clustering measurements
Nock, Kelly; Percival, Will J.; Ross, Ashley J.
2010-01-01
Although redshift-space distortions only affect inferred distances and not angles, they still distort the projected angular clustering of galaxy samples selected using redshift dependent quantities. From an Eulerian view-point, this effect is caused by the apparent movement of galaxies into or out of the sample. From a Lagrangian view-point, we find that projecting the redshift-space overdensity field over a finite radial distance does not remove all the anisotropic distortions. We investigat...
Projective limits of state spaces III. Toy-models
Lanéry, Suzanne; Thiemann, Thomas
2018-01-01
In this series of papers, we investigate the projective framework initiated by Kijowski (1977) and Okołów (2009, 2014, 2013) [1,2], which describes the states of a quantum theory as projective families of density matrices. A short reading guide to the series can be found in Lanéry (2016). A strategy to implement the dynamics in this formalism was presented in our first paper Lanéry and Thiemann (2017) (see also Lanéry, 2016, section 4), which we now test in two simple toy-models. The first one is a very basic linear model, meant as an illustration of the general procedure, and we will only discuss it at the classical level. In the second one, we reformulate the Schrödinger equation, treated as a classical field theory, within this projective framework, and proceed to its (non-relativistic) second quantization. We are then able to reproduce the physical content of the usual Fock quantization.
Visual Odometry for Autonomous Deep-Space Navigation Project
Robinson, Shane; Pedrotty, Sam
2016-01-01
Autonomous rendezvous and docking (AR&D) is a critical need for manned spaceflight, especially in deep space where communication delays essentially leave crews on their own for critical operations like docking. Previously developed AR&D sensors have been large, heavy, power-hungry, and may still require further development (e.g. Flash LiDAR). Other approaches to vision-based navigation are not computationally efficient enough to operate quickly on slower, flight-like computers. The key technical challenge for visual odometry is to adapt it from the current terrestrial applications it was designed for to function in the harsh lighting conditions of space. This effort leveraged Draper Laboratory’s considerable prior development and expertise, benefitting both parties. The algorithm Draper has created is unique from other pose estimation efforts as it has a comparatively small computational footprint (suitable for use onboard a spacecraft, unlike alternatives) and potentially offers accuracy and precision needed for docking. This presents a solution to the AR&D problem that only requires a camera, which is much smaller, lighter, and requires far less power than competing AR&D sensors. We have demonstrated the algorithm’s performance and ability to process ‘flight-like’ imagery formats with a ‘flight-like’ trajectory, positioning ourselves to easily process flight data from the upcoming ‘ISS Selfie’ activity and then compare the algorithm’s quantified performance to the simulated imagery. This will bring visual odometry beyond TRL 5, proving its readiness to be demonstrated as part of an integrated system.Once beyond TRL 5, visual odometry will be poised to be demonstrated as part of a system in an in-space demo where relative pose is critical, like Orion AR&D, ISS robotic operations, asteroid proximity operations, and more.
Space Processing Applications Rocket project, SPAR 1. Final report
International Nuclear Information System (INIS)
Reeves, F.; Chassay, R.
1976-12-01
The experiment objectives, design/operational concepts, and final results of each of nine scientific experiments conducted during the first Space Processing Applications Rocket (SPAR) flight are summarized. The nine individual SPAR experiments, covering a wide and varied range of scientific materials processing objectives, were entitled: solidification of Pb-Sb eutectic, feasibility of producing closed-cell metal foams, characterization of rocket vibration environment by measurement of mixing of two liquids, uniform dispersions of crystallization processing, direct observation of solidification as a function of gravity levels, casting thoria dispersion-strengthened interfaces, contained polycrystalline solidification, and preparation of a special alloy for manufacturing of magnetic hard superconductor under zero-g environment
Insurance and indemnification implications of future space projects
O'Brien, John E.
1987-01-01
NASA options regarding insurance and indemnification policies as they relate to NASA customers and contractors are described. The foundation for the discussion is the way in which NASA is planning to return the Space Shuttle fleet to safe flight as well as current U.S. policy concerning future uses of the Shuttle fleet. Issues discussed include: the nature of the Shuttle manifest; the policy regarding property damage or destruction; insurance against liability to third parties; the reduction of the scope of the risk to be insured; NASA as the insurer; a sharing arrangement between the user and NASA; and contractors and subcontractors involved in Shuttle operations.
Space Processing Applications rocket project SPAR III. Final report
International Nuclear Information System (INIS)
Reeves, F.
1978-01-01
This document presents the engineering report and science payload III test report and summarizes the experiment objectives, design/operational concepts, and final results of each of five scientific experiments conducted during the third Space Processing Applications Rocket (SPAR) flight flown by NASA in December 1976. The five individual SPAR experiments, covering a wide and varied range of scientific materials processing objectives, were entitled: Liquid Mixing, Interaction of Bubbles with Solidification Interfaces, Epitaxial Growth of Single Crystal Film, Containerless Processing of Beryllium, and Contact and Coalescence of Viscous Bodies
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
A generalization of the Friedrichs angle and the method of alternating projections
Czech Academy of Sciences Publication Activity Database
Badea, C.; Grivaux, S.; Müller, Vladimír
2010-01-01
Roč. 348, 1-2 (2010), s. 53-56 ISSN 1631-073X R&D Projects: GA ČR(CZ) GA201/06/0128 Institutional research plan: CEZ:AV0Z10190503 Keywords : Hilbert space * Neumann -Halperin method Subject RIV: BA - General Mathematics Impact factor: 0.399, year: 2010 http://www.sciencedirect.com/science/article/pii/S1631073X09004002
PCB-Caulk Replacement Project Johnson Space Center Houston, TX
Young, William M.; Stanch, Penney M.; Molenda, William
2011-01-01
Wet method reduced exposure by minimizing overall respirable particulate release. Dry method didn't introduce delays for primer/caulk application. Removed caulks came in many forms, from dry powdery to tarry sticky. Varying textures were not sampled or packaged differently. During the course of the project, EPA modified recommended practices to include full containment for exterior caulk removal. Changes are ongoing. Initial recommendations were directed to school buildings. EPA is researching risks due to caulk. Exposure guidance lacking except for 2 of 209 PCB congeners. Work was safely completed on schedule and under budget.
Problem and Project Based Learning in Hybrid Spaces:Nomads and Artisans
Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien
2016-01-01
There is a need within networked learning to understand and conceptualise the interplay between digital and physical spaces or what we could term hybrid spaces. Therefore, we discuss a recent study of students from two different programmes who are engaged in long-term, group-based problem and project based learning. Based on interviews, workshops and observations of students’ actual group practices in open, shared and flexible spaces in Aalborg University (AAU), we identify and discuss how st...
Space-time least-squares Petrov-Galerkin projection in nonlinear model reduction.
Energy Technology Data Exchange (ETDEWEB)
Choi, Youngsoo [Sandia National Laboratories (SNL-CA), Livermore, CA (United States). Extreme-scale Data Science and Analytics Dept.; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Carlberg, Kevin Thomas [Sandia National Laboratories (SNL-CA), Livermore, CA (United States). Extreme-scale Data Science and Analytics Dept.
2017-09-01
Our work proposes a space-time least-squares Petrov-Galerkin (ST-LSPG) projection method for model reduction of nonlinear dynamical systems. In contrast to typical nonlinear model-reduction methods that first apply Petrov-Galerkin projection in the spatial dimension and subsequently apply time integration to numerically resolve the resulting low-dimensional dynamical system, the proposed method applies projection in space and time simultaneously. To accomplish this, the method first introduces a low-dimensional space-time trial subspace, which can be obtained by computing tensor decompositions of state-snapshot data. The method then computes discrete-optimal approximations in this space-time trial subspace by minimizing the residual arising after time discretization over all space and time in a weighted ℓ^{2}-norm. This norm can be de ned to enable complexity reduction (i.e., hyper-reduction) in time, which leads to space-time collocation and space-time GNAT variants of the ST-LSPG method. Advantages of the approach relative to typical spatial-projection-based nonlinear model reduction methods such as Galerkin projection and least-squares Petrov-Galerkin projection include: (1) a reduction of both the spatial and temporal dimensions of the dynamical system, (2) the removal of spurious temporal modes (e.g., unstable growth) from the state space, and (3) error bounds that exhibit slower growth in time. Numerical examples performed on model problems in fluid dynamics demonstrate the ability of the method to generate orders-of-magnitude computational savings relative to spatial-projection-based reduced-order models without sacrificing accuracy.
International Nuclear Information System (INIS)
Ogievetsky, O.; Pillin, M.; Schmidke, W.B.; Wess, J.; Zumino, B.
1993-01-01
In this lecture I discuss the algebraic structure of a q-deformed four-vector space. It serves as a good example of quantizing Minkowski space. To give a physical interpretation of such a quantized Minkowski space we construct the Hilbert space representation and find that the relevant time and space operators have a discrete spectrum. Thus the q-deformed Minkowski space has a lattice structure. Nevertheless this lattice structure is compatible with the operation of q-deformed Lorentz transformations. The generators of the q-deformed Lorentz group can be represented as linear operators in the same Hilbert space. (orig.)
Art & Space: the webbing projects of Eva Petrič
Petrič, E.; Schlacht, I. L.; Foing, B.
2015-10-01
Art is considered a form of communication often related to the perception of personal emotion of the artist. Space is the most extreme environment that a human could approach, this environment affects the human body and the individual's personal perception with metamorphosis created by factors such as, isolation, radiation and difference of gravity. This alteration of the perception could be viewed as a potentiality from artists to acquire and communicate new emotions. To investigate the capacity of an artist to come faster and closer to emotions and to communicate their feeling, a mission simulation has been performed in the ExoLab module [1] from ILEWG [A] on the 29th of April 2015.
National Space Biomedical Research Institute (NSBRI) JSC Summer Projects
Dowdy, Forrest Ryan
2014-01-01
This project optimized the calorie content in a breakfast meal replacement bar for the Advanced Food Technology group. Use of multivariable optimization yielded the highest weight savings possible while simultaneously matching NASA Human Standards nutritional guidelines. The scope of this research included the study of shelf-life indicators such as water activity, moisture content, and texture analysis. Key metrics indicate higher protein content, higher caloric density, and greater mass savings as a result of the reformulation process. The optimization performed for this study demonstrated wide application to other food bars in the Advanced Food Technology portfolio. Recommendations for future work include shelf life studies on bar hardening and overall acceptability data over increased time frames and temperature fluctuation scenarios.
T^{\\sigma}_{\\rho}(G) Theories and Their Hilbert Series
Cremonesi, Stefano; Mekareeya, Noppadol; Zaffaroni, Alberto
2015-01-01
We give an explicit formula for the Higgs and Coulomb branch Hilbert series for the class of 3d N=4 superconformal gauge theories T^{\\sigma}_{\\rho}(G) corresponding to a set of D3 branes ending on NS5 and D5-branes, with or without O3 planes. Here G is a classical group, \\sigma is a partition of G and \\rho a partition of the dual group G^\\vee. In deriving such a formula we make use of the recently discovered formula for the Hilbert series of the quantum Coulomb branch of N=4 superconformal theories. The result can be expressed in terms of a generalization of a class of symmetric functions, the Hall-Littlewood polynomials, and can be interpreted in mathematical language in terms of localization. We mainly consider the case G=SU(N) but some interesting results are also given for orthogonal and symplectic groups.
The Hilbert-Schmidt method for nucleon-deuteron scattering
International Nuclear Information System (INIS)
Moeller, K.; Narodetskii, I.M.
1984-01-01
The Hilbert-Schmidt technique is used for computing the divergent multiple-scattering series for scattering of nucleons by deuterons at energies above the deuteron breakup. We have found that for each partial amplitude a series of s-channel resonances diverges because of the logarithmic singularities which reflect the t-channel singularities of the total amplitude. However, the convergence of the Hilbert-Schmidt series may be improved by iterating the Faddeev equations thereby extracting the most strong logarithmic singularities. We show that the series for the amplitudes with the first two iteration subtracted converges rapidly. Our final results are in excellent agreement with exact results obtained by a direct matrix technique. (orig.)
Hilbert-Schmidt method for nucleon-deuteron scattering
International Nuclear Information System (INIS)
Moeller, K.; Narodetskij, I.M.
1983-01-01
The Hilbert-Schmidt technique is used for computing the divergent multiple-scattering series for scattering of nucleons by deuterons at energies above the deuteron breakup. It is found that for each partial amplitude a series of s-channel resonances diverges because of the logarithmic singularities which reflect the t-channel singularities of the total amplitude. However, the convergence of the Hilbert-Schmidt series may be improved by iterating the Faddeev equations thereby extracting the most strong logarithmic singularities. It is shown that the series for the amplitudes with first two iterations subtracted converges rapidly. Final results are in excellent agreement with exact results obtained by a direct matrix technique
Large Energy Development Projects: Lessons Learned from Space and Politics
International Nuclear Information System (INIS)
Schmitt, Harrison H.
2005-01-01
The challenge to global energy future lies in meeting the needs and aspirations of the ten to twelve billion earthlings that will be on this planet by 2050. At least an eight-fold increase in annual production will be required by the middle of this century. The energy sources that can be considered developed and 'in the box' for consideration as sources for major increases in supply over the next half century are fossil fuels, nuclear fission, and, to a lesser degree, various forms of direct and stored solar energy and conservation. None of these near-term sources of energy will provide an eight-fold or more increase in energy supply for various technical, environmental and political reasons.Only a few potential energy sources that fall 'out of the box' appear worthy of additional consideration as possible contributors to energy demand in 2050 and beyond. These particular candidates are deuterium-tritium fusion, space solar energy, and lunar helium-3 fusion. The primary advantage that lunar helium-3 fusion will have over other 'out of the box' energy sources in the pre-2050 timeframe is a clear path into the private capital markets. The development and demonstration of new energy sources will require several development paths, each of Apollo-like complexity and each with sub-paths of parallel development for critical functions and components
Geometry and experience: Einstein's 1921 paper and Hilbert's axiomatic system
International Nuclear Information System (INIS)
De Gandt, Francois
2006-01-01
In his 1921 paper Geometrie und Erfahrung, Einstein decribes the new epistemological status of geometry, divorced from any intuitive or a priori content. He calls that 'axiomatics', following Hilbert's theoretical developments on axiomatic systems, which started with the stimulus given by a talk by Hermann Wiener in 1891 and progressed until the Foundations of geometry in 1899. Difficult questions arise: how is a theoretical system related to an intuitive empirical content?
How were the Hilbert-Einstein equations discovered?
International Nuclear Information System (INIS)
Logunov, Anatolii A; Mestvirishvili, Mirian A; Petrov, Vladimir A
2004-01-01
The ways in which Albert Einstein and David Hilbert independently arrived at the gravitational field equations are traced. A critical analysis is presented of a number of papers in which the history of the derivation of the equations is viewed in a way that 'radically differs from the standard point of view'. The conclusions of these papers are shown to be totally unfounded. (from the history of physics)
Von Neuman representations on self-dual Hilbert W* moduli
International Nuclear Information System (INIS)
Frank, M.
1987-01-01
Von Neumann algebras M of bounded operators on self-dual Hilbert W* moduli H possessing a cyclic-separating element x-bar in H are considered. The close relation of them to certain real subspaces of H is established. Under the supposition that the underlying W*-algebra is commutative, a Tomita-Takesaki type theorem is stated. The natural cone in H arising from the pair (M, x-bar) is investigated and its properties are obtained
The Einstein-Hilbert gravitation with minimum length
Louzada, H. L. C.
2018-05-01
We study the Einstein-Hilbert gravitation with the deformed Heisenberg algebra leading to the minimum length, with the intention to find and estimate the corrections in this theory, clarifying whether or not it is possible to obtain, by means of the minimum length, a theory, in D=4, which is causal, unitary and provides a massive graviton. Therefore, we will calculate and analyze the dispersion relationships of the considered theory.
Schmerling, E. R.
1975-01-01
The Space Shuttle will open a new era in the exploration of earth's near-space environment, where the weight and power capabilities of Spacelab and the ability to use man in real time add important new features. The Atmospheric, Magnetospheric, and Plasmas-in-Space project (AMPS) is conceived of as a facility where flexible core instruments can be flown repeatedly to perform different observations and experiments. The twin thrusts of remote sensing of the atmosphere below 120 km and active experiments on the space plasma are the major themes. They have broader implications in increasing our understanding of plasma physics and of energy conversion processes elsewhere in the universe.
Directory of Open Access Journals (Sweden)
Mario Losasso
2014-05-01
Full Text Available “Historic Centre of Naples, World Heritage Site Enhancement” project has as its goal the rehabilitation of the oldest part of the historic center of Naples, one of the largest and most representative of Europe. The research reference field is placed on the level of strategic approach to the project and process management downstream of EU funding in large cities, with particular multidisciplinary relevance and urban issues of a complex nature. The scientific products of study, training and research were collected in Guidelines for the rehabilitation of public spaces and for sustainable performance of interventions on roads, walkways, squares and urban facilities.
Uznir, U.; Anton, F.; Suhaibah, A.; Rahman, A. A.; Mioc, D.
2013-09-01
The advantages of three dimensional (3D) city models can be seen in various applications including photogrammetry, urban and regional planning, computer games, etc.. They expand the visualization and analysis capabilities of Geographic Information Systems on cities, and they can be developed using web standards. However, these 3D city models consume much more storage compared to two dimensional (2D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban objects. In this research, we propose an opponent data constellation technique of space-filling curves (3D Hilbert curves) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA) or Hilbert mappings, in this research, we extend the Hilbert space-filling curve to one higher dimension for 3D city model data implementations. The query performance was tested using a CityGML dataset of 1,000 building blocks and the results are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert's curve, preserves the Lebesgue measure and is Lipschitz continuous. Depending on the applications, several alternatives are possible in order to cluster spatial data together in the third dimension compared to its
Directory of Open Access Journals (Sweden)
Yoshikawa Akimasa
2017-01-01
Full Text Available For study of coupling processes in the Solar-Terrestrial System, International Center for Space Weather Science and Education (ICSWSE, Kyushu University has developed a real time magnetic data acquisition system (the MAGDAS project around the world. The number of observational sites is increasing every year with the collaboration of host countries. Now at this time, the MAGDAS Project has installed 78 real time magnetometers – so it is the largest magnetometer array in the world. The history of global observation at Kyushu University is over 30 years and number of developed observational sites is over 140. Especially, Collaboration between IKIR is extended back to 1990's. Now a time, we are operating Flux-gate magnetometer and FM-CW Radar. It is one of most important collaboration for space weather monitoring. By using MAGDAS data, ICSWSE produces many types of space weather index, such as EE-index (for monitoring long tern and shot term variation of equatorial electrojet, Pc5 index (for monitoring solar-wind velocity and high energy electron flux, Sq-index (for monitoring global change of ionospheric low and middle latitudinal current system, and Pc3 index (for monitoring of plasma density variation at low latitudes. In this report, we will introduce recent development of MAGDAS/ICSWSE Indexes project and topics for new open policy for MAGDAS data will be also discussed.
Yoshikawa, Akimasa; Fujimoto, Akiko; Ikeda, Akihiro; Uozumi, Teiji; Abe, Shuji
2017-10-01
For study of coupling processes in the Solar-Terrestrial System, International Center for Space Weather Science and Education (ICSWSE), Kyushu University has developed a real time magnetic data acquisition system (the MAGDAS project) around the world. The number of observational sites is increasing every year with the collaboration of host countries. Now at this time, the MAGDAS Project has installed 78 real time magnetometers - so it is the largest magnetometer array in the world. The history of global observation at Kyushu University is over 30 years and number of developed observational sites is over 140. Especially, Collaboration between IKIR is extended back to 1990's. Now a time, we are operating Flux-gate magnetometer and FM-CW Radar. It is one of most important collaboration for space weather monitoring. By using MAGDAS data, ICSWSE produces many types of space weather index, such as EE-index (for monitoring long tern and shot term variation of equatorial electrojet), Pc5 index (for monitoring solar-wind velocity and high energy electron flux), Sq-index (for monitoring global change of ionospheric low and middle latitudinal current system), and Pc3 index (for monitoring of plasma density variation at low latitudes). In this report, we will introduce recent development of MAGDAS/ICSWSE Indexes project and topics for new open policy for MAGDAS data will be also discussed.
Aerogel Use as a Skin Protective Liner In Space Suits and Prosthetic Limbs Project
Roberson, Luke Bennett
2014-01-01
Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications for use in space suits and orthopedics. Three tests were performed on several types of aerogel to assess the properties of each material, and our initial findings demonstrated that these materrials would be excellent candidates for liner applications for prosthetics and space suits. The project is currently on hold until additional funding is obtained for application testing at the VH Hospitals in Tampa
EGNOS Monitoring Prepared in Space Research Centre P.A.S. for SPMS Project
Swiatek, Anna; Jaworski, Leszek; Tomasik, Lukasz
2017-12-01
The European Geostationary Overlay Service (EGNOS) augments Global Positioning System (GPS) by providing correction data and integrity information for improving positioning over Europe. EGNOS Service Performance Monitoring Support (SPMS) project has assumed establishment, maintenance and implementation of an EGNOS performance monitoring network. The paper presents preliminary results of analyses prepared in Space Research Centre, Polish Academy of Sciences (Warsaw), as one of partners in SPMS project.
The scientific data acquisition system of the GAMMA-400 space project
Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Arkhangelskiy, A. I.; Topchiev, N. P.
2016-02-01
The description of scientific data acquisition system (SDAS) designed by SRISA for the GAMMA-400 space project is presented. We consider the problem of different level electronics unification: the set of reliable fault-tolerant integrated circuits fabricated on Silicon-on-Insulator 0.25 mkm CMOS technology and the high-speed interfaces and reliable modules used in the space instruments. The characteristics of reliable fault-tolerant very large scale integration (VLSI) technology designed by SRISA for the developing of computation systems for space applications are considered. The scalable net structure of SDAS based on Serial RapidIO interface including real-time operating system BAGET is described too.
Reduced aliasing artifacts using shaking projection k-space sampling trajectory
Zhu, Yan-Chun; Du, Jiang; Yang, Wen-Chao; Duan, Chai-Jie; Wang, Hao-Yu; Gao, Song; Bao, Shang-Lian
2014-03-01
Radial imaging techniques, such as projection-reconstruction (PR), are used in magnetic resonance imaging (MRI) for dynamic imaging, angiography, and short-T2 imaging. They are less sensitive to flow and motion artifacts, and support fast imaging with short echo times. However, aliasing and streaking artifacts are two main sources which degrade radial imaging quality. For a given fixed number of k-space projections, data distributions along radial and angular directions will influence the level of aliasing and streaking artifacts. Conventional radial k-space sampling trajectory introduces an aliasing artifact at the first principal ring of point spread function (PSF). In this paper, a shaking projection (SP) k-space sampling trajectory was proposed to reduce aliasing artifacts in MR images. SP sampling trajectory shifts the projection alternately along the k-space center, which separates k-space data in the azimuthal direction. Simulations based on conventional and SP sampling trajectories were compared with the same number projections. A significant reduction of aliasing artifacts was observed using the SP sampling trajectory. These two trajectories were also compared with different sampling frequencies. A SP trajectory has the same aliasing character when using half sampling frequency (or half data) for reconstruction. SNR comparisons with different white noise levels show that these two trajectories have the same SNR character. In conclusion, the SP trajectory can reduce the aliasing artifact without decreasing SNR and also provide a way for undersampling reconstruction. Furthermore, this method can be applied to three-dimensional (3D) hybrid or spherical radial k-space sampling for a more efficient reduction of aliasing artifacts.
Reduced aliasing artifacts using shaking projection k-space sampling trajectory
International Nuclear Information System (INIS)
Zhu Yan-Chun; Yang Wen-Chao; Wang Hao-Yu; Gao Song; Bao Shang-Lian; Du Jiang; Duan Chai-Jie
2014-01-01
Radial imaging techniques, such as projection-reconstruction (PR), are used in magnetic resonance imaging (MRI) for dynamic imaging, angiography, and short-T2 imaging. They are less sensitive to flow and motion artifacts, and support fast imaging with short echo times. However, aliasing and streaking artifacts are two main sources which degrade radial imaging quality. For a given fixed number of k-space projections, data distributions along radial and angular directions will influence the level of aliasing and streaking artifacts. Conventional radial k-space sampling trajectory introduces an aliasing artifact at the first principal ring of point spread function (PSF). In this paper, a shaking projection (SP) k-space sampling trajectory was proposed to reduce aliasing artifacts in MR images. SP sampling trajectory shifts the projection alternately along the k-space center, which separates k-space data in the azimuthal direction. Simulations based on conventional and SP sampling trajectories were compared with the same number projections. A significant reduction of aliasing artifacts was observed using the SP sampling trajectory. These two trajectories were also compared with different sampling frequencies. A SP trajectory has the same aliasing character when using half sampling frequency (or half data) for reconstruction. SNR comparisons with different white noise levels show that these two trajectories have the same SNR character. In conclusion, the SP trajectory can reduce the aliasing artifact without decreasing SNR and also provide a way for undersampling reconstruction. Furthermore, this method can be applied to three-dimensional (3D) hybrid or spherical radial k-space sampling for a more efficient reduction of aliasing artifacts
Uniform sparse bounds for discrete quadratic phase Hilbert transforms
Kesler, Robert; Arias, Darío Mena
2017-09-01
For each α \\in T consider the discrete quadratic phase Hilbert transform acting on finitely supported functions f : Z → C according to H^{α }f(n):= \\sum _{m ≠ 0} e^{iα m^2} f(n - m)/m. We prove that, uniformly in α \\in T , there is a sparse bound for the bilinear form for every pair of finitely supported functions f,g : Z→ C . The sparse bound implies several mapping properties such as weighted inequalities in an intersection of Muckenhoupt and reverse Hölder classes.
A Proof of the Hilbert-Smith Conjecture
McAuley, Louis F.
2001-01-01
The Hilbert-Smith Conjecture states that if G is a locally compact group which acts effectively on a connected manifold as a topological transformation group, then G is a Lie group. A rather straightforward proof of this conjecture is given. The motivation is work of Cernavskii (``Finite-to-one mappings of manifolds'', Trans. of Math. Sk. 65 (107), 1964.) His work is generalized to the orbit map of an effective action of a p-adic group on compact connected n-manifolds with the aid of some new...
Time average vibration fringe analysis using Hilbert transformation
International Nuclear Information System (INIS)
Kumar, Upputuri Paul; Mohan, Nandigana Krishna; Kothiyal, Mahendra Prasad
2010-01-01
Quantitative phase information from a single interferogram can be obtained using the Hilbert transform (HT). We have applied the HT method for quantitative evaluation of Bessel fringes obtained in time average TV holography. The method requires only one fringe pattern for the extraction of vibration amplitude and reduces the complexity in quantifying the data experienced in the time average reference bias modulation method, which uses multiple fringe frames. The technique is demonstrated for the measurement of out-of-plane vibration amplitude on a small scale specimen using a time average microscopic TV holography system.
Smith, D. B. S.
1982-01-01
The potential applications of Automation, Robotics, and Machine Intelligence Systems (ARAMIS) to space projects are investigated, through a systematic method. In this method selected space projects are broken down into space project tasks, and 69 of these tasks are selected for study. Candidate ARAMIS options are defined for each task. The relative merits of these options are evaluated according to seven indices of performance. Logical sequences of ARAMIS development are also defined. Based on this data, promising applications of ARAMIS are
RFI Mitigation and Testing Employed at GGAO for NASA's Space Geodesy Project (SGP)
Hilliard, L. M.; Rajagopalan, Ganesh; Turner, Charles; Stevenson, Thomas; Bulcha, Berhanu
2017-01-01
Radio Frequency Interference (RFI) Mitigation at Goddard Geophysical and Astronomical Observatory (GGAO) has been addressed in three different ways by NASA's Space Geodesy Project (SGP); masks, blockers, and filters. All of these techniques will be employed at the GGAO, to mitigate the RFI consequences to the Very Long Baseline Interferometer.
Space Versus Time: Unimodular Versus Non-Unimodular Projective Ring Geometries?
Czech Academy of Sciences Publication Activity Database
Saniga, M.; Pracna, Petr
2010-01-01
Roč. 4, - (2010), s. 719-735 ISSN 2159-063X Institutional research plan: CEZ:AV0Z40400503 Keywords : projective ring lines * smallest ring of ternions * Germas: of space-time Subject RIV: CF - Physical ; Theoretical Chemistry http://journalofcosmology.com/Multiverse4.html
Energy Technology Data Exchange (ETDEWEB)
Smith, D B.S.
1983-01-01
The potential applications of automation, robotics and machine intelligence systems (ARAMIS) to space projects are investigated, through a systematic method. In this method selected space projects are broken down into space project tasks, and 69 of these tasks are selected for study. Candidate ARAMIS options are defined for each task. The relative merits of these options are evaluated according to seven indices of performance. Logical sequences of ARAMIS development are also defined. Based on this data, promising applications of ARAMIS are identified for space project tasks. General conclusions and recommendations for further study are also presented. 6 references.
Planning and managing future space facility projects. [management by objectives and group dynamics
Sieber, J. E.; Wilhelm, J. A.; Tanner, T. A.; Helmreich, R. L.; Burgenbauch, S. F.
1979-01-01
To learn how ground-based personnel of a space project plan and organize their work and how such planning and organizing relate to work outcomes, longitudinal study of the management and execution of the Space Lab Mission Development Test 3 (SMD 3) was performed at NASA Ames Research Center. A view of the problems likely to arise in organizations and some methods of coping with these problems are presented as well as the conclusions and recommendations that pertain strictly to SMD 3 management. Emphasis is placed on the broader context of future space facility projects and additional problems that may be anticipated. A model of management that may be used to facilitate problem solving and communication - management by objectives (MBO) is presented. Some problems of communication and emotion management that MBO does not address directly are considered. Models for promoting mature, constructive and satisfying emotional relationships among group members are discussed.
New opportunities offered by Cubesats for space research in Latin America: The SUCHAI project case
Diaz, M. A.; Zagal, J. C.; Falcon, C.; Stepanova, M.; Valdivia, J. A.; Martinez-Ledesma, M.; Diaz-Peña, J.; Jaramillo, F. R.; Romanova, N.; Pacheco, E.; Milla, M.; Orchard, M.; Silva, J.; Mena, F. P.
2016-11-01
During the last decade, a very small-standardized satellite, the Cubesat, emerged as a low-cost fast-development tool for space and technology research. Although its genesis is related to education, the change in paradigm presented by this satellite platform has motivated several countries, institutions, and companies to invest in a variety of technologies, aimed at improving Cubesat capabilities, while lowering costs of space missions. Following that trend, Latin American institutions, mostly universities, has started to develop Cubesat missions. This article describes some of the Latin American projects in this area. In particular, we discuss the achievements and scientific grounds upon which the first Cubesat projects in Chile were based and the implications that those projects have had on pursuing satellite-based research in the country and in collaboration with other countries of the region.
Applications of Hilbert Spectral Analysis for Speech and Sound Signals
Huang, Norden E.
2003-01-01
A new method for analyzing nonlinear and nonstationary data has been developed, and the natural applications are to speech and sound signals. The key part of the method is the Empirical Mode Decomposition method with which any complicated data set can be decomposed into a finite and often small number of Intrinsic Mode Functions (IMF). An IMF is defined as any function having the same numbers of zero-crossing and extrema, and also having symmetric envelopes defined by the local maxima and minima respectively. The IMF also admits well-behaved Hilbert transform. This decomposition method is adaptive, and, therefore, highly efficient. Since the decomposition is based on the local characteristic time scale of the data, it is applicable to nonlinear and nonstationary processes. With the Hilbert transform, the Intrinsic Mode Functions yield instantaneous frequencies as functions of time, which give sharp identifications of imbedded structures. This method invention can be used to process all acoustic signals. Specifically, it can process the speech signals for Speech synthesis, Speaker identification and verification, Speech recognition, and Sound signal enhancement and filtering. Additionally, as the acoustical signals from machinery are essentially the way the machines are talking to us. Therefore, the acoustical signals, from the machines, either from sound through air or vibration on the machines, can tell us the operating conditions of the machines. Thus, we can use the acoustic signal to diagnosis the problems of machines.
Multisymplectic unified formalism for Einstein-Hilbert gravity
Gaset, Jordi; Román-Roy, Narciso
2018-03-01
We present a covariant multisymplectic formulation for the Einstein-Hilbert model of general relativity. As it is described by a second-order singular Lagrangian, this is a gauge field theory with constraints. The use of the unified Lagrangian-Hamiltonian formalism is particularly interesting when it is applied to these kinds of theories, since it simplifies the treatment of them, in particular, the implementation of the constraint algorithm, the retrieval of the Lagrangian description, and the construction of the covariant Hamiltonian formalism. In order to apply this algorithm to the covariant field equations, they must be written in a suitable geometrical way, which consists of using integrable distributions, represented by multivector fields of a certain type. We apply all these tools to the Einstein-Hilbert model without and with energy-matter sources. We obtain and explain the geometrical and physical meaning of the Lagrangian constraints and we construct the multimomentum (covariant) Hamiltonian formalisms in both cases. As a consequence of the gauge freedom and the constraint algorithm, we see how this model is equivalent to a first-order regular theory, without gauge freedom. In the case of the presence of energy-matter sources, we show how some relevant geometrical and physical characteristics of the theory depend on the type of source. In all the cases, we obtain explicitly multivector fields which are solutions to the gravitational field equations. Finally, a brief study of symmetries and conservation laws is done in this context.
International Roughness Index (IRI) measurement using Hilbert-Huang transform
Zhang, Wenjin; Wang, Ming L.
2018-03-01
International Roughness Index (IRI) is an important metric to measure condition of roadways. This index is usually used to justify the maintenance priority and scheduling for roadways. Various inspection methods and algorithms are used to assess this index through the use of road profiles. This study proposes to calculate IRI values using Hilbert-Huang Transform (HHT) algorithm. In particular, road profile data is provided using surface radar attached to a vehicle driving at highway speed. Hilbert-Huang transform (HHT) is used in this study because of its superior properties for nonstationary and nonlinear data. Empirical mode decomposition (EMD) processes the raw data into a set of intrinsic mode functions (IMFs), representing various dominating frequencies. These various frequencies represent noises from the body of the vehicle, sensor location, and the excitation induced by nature frequency of the vehicle, etc. IRI calculation can be achieved by eliminating noises that are not associated with the road profile including vehicle inertia effect. The resulting IRI values are compared favorably to the field IRI values, where the filtered IMFs captures the most characteristics of road profile while eliminating noises from the vehicle and the vehicle inertia effect. Therefore, HHT is an effect method for road profile analysis and for IRI measurement. Furthermore, the application of HHT method has the potential to eliminate the use of accelerometers attached to the vehicle as part of the displacement measurement used to offset the inertia effect.
Hilbert-Schmidt quantum coherence in multi-qudit systems
Maziero, Jonas
2017-11-01
Using Bloch's parametrization for qudits ( d-level quantum systems), we write the Hilbert-Schmidt distance (HSD) between two generic n-qudit states as an Euclidean distance between two vectors of observables mean values in R^{Π_{s=1}nds2-1}, where ds is the dimension for qudit s. Then, applying the generalized Gell-Mann's matrices to generate SU(ds), we use that result to obtain the Hilbert-Schmidt quantum coherence (HSC) of n-qudit systems. As examples, we consider in detail one-qubit, one-qutrit, two-qubit, and two copies of one-qubit states. In this last case, the possibility for controlling local and non-local coherences by tuning local populations is studied, and the contrasting behaviors of HSC, l1-norm coherence, and relative entropy of coherence in this regard are noticed. We also investigate the decoherent dynamics of these coherence functions under the action of qutrit dephasing and dissipation channels. At last, we analyze the non-monotonicity of HSD under tensor products and report the first instance of a consequence (for coherence quantification) of this kind of property of a quantum distance measure.
Directory of Open Access Journals (Sweden)
Pedro Brandão
2015-06-01
• In the development of design practice and studio teaching methods We shall see in this paper how interdisciplinary approaches correspond to new and complex urban transformations, focusing on the importance of actors’ interaction processes, combining professional and non-professional knowledge and theory-practice relations. Therefore, we aim at a deepening in public space area of knowledge under the growing complexity of urban life. We see it as a base for further development of collaborative projects and their implications on community empowerment and urban governance at local level. Motivations of this line of work are persistent in several ongoing research projects, aiming to: - Understand public space as a cohesion factor both in urban life and urban form - Manage processes and strategies as elements of urban transformation, - Stimulate the understanding of actors’ roles in urban design practices. - Favoring the questioning of emerging aspects of urban space production… The paper presents and analyses processes, methods and results from civic participation projects developed in the neighbourhood of Barò de Viver (Barcelona and in the District of Marvila (Lisbon. In the first case, a long process initiated in 2004 and partially completed in 2011, neighbours developed the projects "Memory Wall" and Ciutat d'Asuncion Promenade as part of identity construction in public space, in collaboration with a team of facilitators from CrPolis group. In the second case, different participatory processes dated from 2001 and 2003 have resulted in the implementation of a specific identity urban brand and communication system with an ongoing project of "maps" construction according to the neighbours perception and representation systems. We may conclude that processes of urban governance require more active participation of citizens in projects regarding the improvement of quality of life. At the same time, the implementation of these processes requires a clear
Technical needs and research opportunities provided by projected aeronautical and space systems
Noor, Ahmed K.
1992-01-01
The overall goal of the present task is to identify the enabling and supporting technologies for projected aeronautical and space systems. A detailed examination was made of the technical needs in the structures, dynamics and materials areas required for the realization of these systems. Also, the level of integration required with other disciplines was identified. The aeronautical systems considered cover the broad spectrum of rotorcraft; subsonic, supersonic and hypersonic aircraft; extremely high-altitude aircraft; and transatmospheric vehicles. The space systems considered include space transportation systems; spacecrafts for near-earth observation; spacecrafts for planetary and solar exploration; and large space systems. A monograph is being compiled which summarizes the results of this study. The different chapters of the monograph are being written by leading experts from governmental laboratories, industry and universities.
Sexual health promotion on social networking sites: a process evaluation of The FaceSpace Project.
Nguyen, Phuong; Gold, Judy; Pedrana, Alisa; Chang, Shanton; Howard, Steve; Ilic, Olivia; Hellard, Margaret; Stoove, Mark
2013-07-01
This article reports findings from an evaluation of reach and engagement of The FaceSpace Project, a novel sexual health promotion project delivered through social networking sites that targeted young people aged 16-29 years. Multiple methods were used to evaluate project reach and engagement. The evaluation focussed on quantitative data (online usage statistics, online surveys), complemented by available qualitative data (project team meeting notes). The project reached 900 fans who were mostly between 18 and 34 years of age. The most successful ways of increasing audience reach were via Facebook advertisements and tagging photos of young people attending a music festival on the project Facebook page. Peaks in Facebook page interactions (comments and "likes") coincided with recruitment peaks and when videos were posted. However, video views varied greatly between postings. Feedback from the project team for increasing engagement in future social networking site interventions included having one centralized Facebook page and using episodic videos. This evaluation is among the first to assess the use of social networking sites for sexual health promotion and provides information to inform the implementation and evaluation of future projects using new media. Social networking sites offer great potential to reach and engage young people for sexual health promotion. However, further work is required to improve implementation and promote audience reach and engagement as well as to determine effectiveness of social networking sites in changing knowledge, attitudes, and behaviors. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
On using the Hilbert transform for blind identification of complex modes: A practical approach
Antunes, Jose; Debut, Vincent; Piteau, Pilippe; Delaune, Xavier; Borsoi, Laurent
2018-01-01
The modal identification of dynamical systems under operational conditions, when subjected to wide-band unmeasured excitations, is today a viable alternative to more traditional modal identification approaches based on processing sets of measured FRFs or impulse responses. Among current techniques for performing operational modal identification, the so-called blind identification methods are the subject of considerable investigation. In particular, the SOBI (Second-Order Blind Identification) method was found to be quite efficient. SOBI was originally developed for systems with normal modes. To address systems with complex modes, various extension approaches have been proposed, in particular: (a) Using a first-order state-space formulation for the system dynamics; (b) Building complex analytic signals from the measured responses using the Hilbert transform. In this paper we further explore the latter option, which is conceptually interesting while preserving the model order and size. Focus is on applicability of the SOBI technique for extracting the modal responses from analytic signals built from a set of vibratory responses. The novelty of this work is to propose a straightforward computational procedure for obtaining the complex cross-correlation response matrix to be used for the modal identification procedure. After clarifying subtle aspects of the general theoretical framework, we demonstrate that the correlation matrix of the analytic responses can be computed through a Hilbert transform of the real correlation matrix, so that the actual time-domain responses are no longer required for modal identification purposes. The numerical validation of the proposed technique is presented based on time-domain simulations of a conceptual physical multi-modal system, designed to display modes ranging from normal to highly complex, while keeping modal damping low and nearly independent of the modal complexity, and which can prove very interesting in test bench
Mars Atmospheric In Situ Resource Utilization Projects at the Kennedy Space Center
Muscatello, A. C.; Hintze, P. E.; Caraccio, A. J.; Bayliss, J. A.; Karr, L. J.; Paley, M. S.; Marone, M. J.; Gibson, T. L.; Surma, J. M.; Mansell, J. M.;
2016-01-01
The atmosphere of Mars, which is approximately 95% carbon dioxide (CO2), is a rich resource for the human exploration of the red planet, primarily by the production of rocket propellants and oxygen for life support. Three recent projects led by NASA's Kennedy Space Center have been investigating the processing of CO2. The first project successfully demonstrated the Mars Atmospheric Processing Module (APM), which freezes CO2 with cryocoolers and combines sublimated CO2 with hydrogen to make methane and water. The second project absorbs CO2 with Ionic Liquids and electrolyzes it with water to make methane and oxygen, but with limited success so far. A third project plans to recover up to 100% of the oxygen in spacecraft respiratory CO2. A combination of the Reverse Water Gas Shift reaction and the Boudouard reaction eventually fill the reactor up with carbon, stopping the process. A system to continuously remove and collect carbon is under construction.
Mars Atmospheric In Situ Resource Utilization Projects at the Kennedy Space Center
Muscatello, Anthony; Hintze, Paul; Meier, Anne; Bayliss, Jon; Karr, Laurel; Paley, Steve; Marone, Matt; Gibson, Tracy; Surma, Jan; Mansell, Matt;
2016-01-01
The atmosphere of Mars, which is 96 percent carbon dioxide (CO2), is a rich resource for the human exploration of the red planet, primarily by the production of rocket propellants and oxygen for life support. Three recent projects led by NASAs Kennedy Space Center have been investigating the processing of CO2. The first project successfully demonstrated the Mars Atmospheric Processing Module (APM), which freezes CO2 with cryocoolers and combines sublimated CO2 with hydrogen to make methane and water. The second project absorbs CO2 with Ionic Liquids and electrolyzes it with water to make methane and oxygen, but with limited success so far. A third project plans to recover up to 100 of the oxygen in spacecraft respiratory CO2. A combination of the Reverse Water Gas Shift reaction and the Boudouard reaction eventually fill the reactor up with carbon, stopping the process. A system to continuously remove and collect carbon has been tested with encouraging results.
NASA GeneLab Project: Bridging Space Radiation Omics with Ground Studies
Beheshti, Afshin; Miller, Jack; Kidane, Yared H.; Berrios, Daniel; Gebre, Samrawit G.; Costes, Sylvain V.
2018-01-01
Accurate assessment of risk factors for long-term space missions is critical for human space exploration: therefore it is essential to have a detailed understanding of the biological effects on humans living and working in deep space. Ionizing radiation from Galactic Cosmic Rays (GCR) is one of the major risk factors factor that will impact health of astronauts on extended missions outside the protective effects of the Earth's magnetic field. Currently there are gaps in our knowledge of the health risks associated with chronic low dose, low dose rate ionizing radiation, specifically ions associated with high (H) atomic number (Z) and energy (E). The GeneLab project (genelab.nasa.gov) aims to provide a detailed library of Omics datasets associated with biological samples exposed to HZE. The GeneLab Data System (GLDS) currently includes datasets from both spaceflight and ground-based studies, a majority of which involve exposure to ionizing radiation. In addition to detailed information for ground-based studies, we are in the process of adding detailed, curated dosimetry information for spaceflight missions. GeneLab is the first comprehensive Omics database for space related research from which an investigator can generate hypotheses to direct future experiments utilizing both ground and space biological radiation data. In addition to previously acquired data, the GLDS is continually expanding as Omics related data are generated by the space life sciences community. Here we provide a brief summary of space radiation related data available at GeneLab.
NASA GeneLab Project: Bridging Space Radiation Omics with Ground Studies.
Beheshti, Afshin; Miller, Jack; Kidane, Yared; Berrios, Daniel; Gebre, Samrawit G; Costes, Sylvain V
2018-04-13
Accurate assessment of risks of long-term space missions is critical for human space exploration. It is essential to have a detailed understanding of the biological effects on humans living and working in deep space. Ionizing radiation from galactic cosmic rays (GCR) is a major health risk factor for astronauts on extended missions outside the protective effects of the Earth's magnetic field. Currently, there are gaps in our knowledge of the health risks associated with chronic low-dose, low-dose-rate ionizing radiation, specifically ions associated with high (H) atomic number (Z) and energy (E). The NASA GeneLab project ( https://genelab.nasa.gov/ ) aims to provide a detailed library of omics datasets associated with biological samples exposed to HZE. The GeneLab Data System (GLDS) includes datasets from both spaceflight and ground-based studies, a majority of which involve exposure to ionizing radiation. In addition to detailed information on radiation exposure for ground-based studies, GeneLab is adding detailed, curated dosimetry information for spaceflight experiments. GeneLab is the first comprehensive omics database for space-related research from which an investigator can generate hypotheses to direct future experiments, utilizing both ground and space biological radiation data. The GLDS is continually expanding as omics-related data are generated by the space life sciences community. Here we provide a brief summary of the space radiation-related data available at GeneLab.
Differentiable absorption of Hilbert C*-modules, connections and lifts of unbounded operators
DEFF Research Database (Denmark)
Kaad, Jens
2017-01-01
. The differentiable absorption theorem is then applied to construct densely defined connections (or correpondences) on Hilbert C∗C∗-modules. These connections can in turn be used to define selfadjoint and regular "lifts" of unbounded operators which act on an auxiliary Hilbert C∗C∗-module....
Projecting technology change to improve space technology planning and systems management
Walk, Steven Robert
2011-04-01
Projecting technology performance evolution has been improving over the years. Reliable quantitative forecasting methods have been developed that project the growth, diffusion, and performance of technology in time, including projecting technology substitutions, saturation levels, and performance improvements. These forecasts can be applied at the early stages of space technology planning to better predict available future technology performance, assure the successful selection of technology, and improve technology systems management strategy. Often what is published as a technology forecast is simply scenario planning, usually made by extrapolating current trends into the future, with perhaps some subjective insight added. Typically, the accuracy of such predictions falls rapidly with distance in time. Quantitative technology forecasting (QTF), on the other hand, includes the study of historic data to identify one of or a combination of several recognized universal technology diffusion or substitution patterns. In the same manner that quantitative models of physical phenomena provide excellent predictions of system behavior, so do QTF models provide reliable technological performance trajectories. In practice, a quantitative technology forecast is completed to ascertain with confidence when the projected performance of a technology or system of technologies will occur. Such projections provide reliable time-referenced information when considering cost and performance trade-offs in maintaining, replacing, or migrating a technology, component, or system. This paper introduces various quantitative technology forecasting techniques and illustrates their practical application in space technology and technology systems management.
Directory of Open Access Journals (Sweden)
Majewski M.
2015-06-01
Full Text Available The parametric OMI (Optimization in Multiple Intervals, the Yoshida-Magalas (YM and a novel Hilbert-twin (H-twin methods are advocated for computing the logarithmic decrement in the field of internal friction and mechanical spectroscopy of solids. It is shown that dispersion in experimental points results mainly from the selection of the computing methods, the number of oscillations, and noise. It is demonstrated that conventional Hilbert transform method suffers from high dispersion in internal friction values. It is unequivocally demonstrated that the Hilbert-twin method, which yields a ‘true envelope’ for exponentially damped harmonic oscillations is superior to conventional Hilbert transform method. The ‘true envelope’ of free decaying strain signals calculated from the Hilbert-twin method yields excellent estimation of the logarithmic decrement in metals, alloys, and solids.
Terahertz bandwidth all-optical Hilbert transformers based on long-period gratings.
Ashrafi, Reza; Azaña, José
2012-07-01
A novel, all-optical design for implementing terahertz (THz) bandwidth real-time Hilbert transformers is proposed and numerically demonstrated. An all-optical Hilbert transformer can be implemented using a uniform-period long-period grating (LPG) with a properly designed amplitude-only grating apodization profile, incorporating a single π-phase shift in the middle of the grating length. The designed LPG-based Hilbert transformers can be practically implemented using either fiber-optic or integrated-waveguide technologies. As a generalization, photonic fractional Hilbert transformers are also designed based on the same optical platform. In this general case, the resulting LPGs have multiple π-phase shifts along the grating length. Our numerical simulations confirm that all-optical Hilbert transformers capable of processing arbitrary optical signals with bandwidths well in the THz range can be implemented using feasible fiber/waveguide LPG designs.
Progress update of NASA's free-piston Stirling space power converter technology project
Dudenhoefer, James E.; Winter, Jerry M.; Alger, Donald
1992-01-01
A progress update is presented of the NASA LeRC Free-Piston Stirling Space Power Converter Technology Project. This work is being conducted under NASA's Civil Space Technology Initiative (CSTI). The goal of the CSTI High Capacity Power Element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space initiatives. Efforts are focused upon increasing system power output and system thermal and electric energy conversion efficiency at least five fold over current SP-100 technology, and on achieving systems that are compatible with space nuclear reactors. This paper will discuss progress toward 1050 K Stirling Space Power Converters. Fabrication is nearly completed for the 1050 K Component Test Power Converter (CTPC); results of motoring tests of the cold end (525 K), are presented. The success of these and future designs is dependent upon supporting research and technology efforts including heat pipes, bearings, superalloy joining technologies, high efficiency alternators, life and reliability testing, and predictive methodologies. This paper will compare progress in significant areas of component development from the start of the program with the Space Power Development Engine (SPDE) to the present work on CTPC.
General-purpose heat source project and space nuclear safety and fuels program. Progress report
International Nuclear Information System (INIS)
Maraman, W.J.
1979-12-01
This formal monthly report covers the studies related to the use of 238 PuO 2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed hear are of a continuing nature. Results and conclusions described may change as the work continues
Directory of Open Access Journals (Sweden)
Yun-zhi Zou
2012-01-01
Full Text Available A new class of generalized dynamical systems involving generalized f-projection operators is introduced and studied in Banach spaces. By using the fixed-point theorem due to Nadler, the equilibrium points set of this class of generalized global dynamical systems is proved to be nonempty and closed under some suitable conditions. Moreover, the solutions set of the systems with set-valued perturbation is showed to be continuous with respect to the initial value.
The TERRA project, a space nuclear micro-reactor case study
Energy Technology Data Exchange (ETDEWEB)
Guimaraes, Lamartine N.F.; Nascimento, Jamil A.; Borges, Eduardo M.; Lobo, Paulo D. Castro, E-mail: guimarae@ieav.cta.br, E-mail: jamil@ieav.cta.br, E-mail: eduardo@ieav.cta.br [Divisao de Energia Nuclear. Instituto de Estudos Avancados, Sao Jose dos Campos, SP (Brazil); Placco, Guilherme M.; Barrios Junior, Ary G. [Faculdade de Tecnologia Sao Francisco (FATESF), Jacarei, SP (Brazil)
2011-07-01
The TEcnologia de Reatores Rapidos Avancados project, also known as TERRA Project is been conducted by the Institute for Advanced Studies IEAv. The TERRA project has a general objective of understanding and developing the key technologies that will allow (Brazil) the use of nuclear technology to generate electricity in space. This electricity may power several space systems and/or a type of plasma based engine. Also, the type of reactor intended for space may be used for power generation in very inhospitable environment such as the ocean floor. Some of the mentioned technologies may include: Brayton cycles, Stirling engines, heat pipes and its coupled systems, nuclear fuel technology, new materials and several others. Once there is no mission into which apply this technology, at this moment, this research may be conducted in many forms and ways. The fact remains that when this technology becomes needed there will be no way that we (Brazilians) will be able to buy it from. This technology, in this sense, is highly strategic and will be the key to commercially explore deep space. Therefore, there is the need to face the development problems and solve them, to gain experience with our own rights and wrongs. This paper will give a brief overview of what has been done so far, on experimental facilities and hardware that could support space system development, including a Brayton cycle test facility, Tesla turbine testing, and Stirling engine development and modeling. Our great problem today is lack of human resources. To attend that problem we are starting a new graduate program that will allow overcoming that, given the proper time frame. (author)
The TERRA project, a space nuclear micro-reactor case study
International Nuclear Information System (INIS)
Guimaraes, Lamartine N.F.; Nascimento, Jamil A.; Borges, Eduardo M.; Lobo, Paulo D. Castro; Placco, Guilherme M.; Barrios Junior, Ary G.
2011-01-01
The TEcnologia de Reatores Rapidos Avancados project, also known as TERRA Project is been conducted by the Institute for Advanced Studies IEAv. The TERRA project has a general objective of understanding and developing the key technologies that will allow (Brazil) the use of nuclear technology to generate electricity in space. This electricity may power several space systems and/or a type of plasma based engine. Also, the type of reactor intended for space may be used for power generation in very inhospitable environment such as the ocean floor. Some of the mentioned technologies may include: Brayton cycles, Stirling engines, heat pipes and its coupled systems, nuclear fuel technology, new materials and several others. Once there is no mission into which apply this technology, at this moment, this research may be conducted in many forms and ways. The fact remains that when this technology becomes needed there will be no way that we (Brazilians) will be able to buy it from. This technology, in this sense, is highly strategic and will be the key to commercially explore deep space. Therefore, there is the need to face the development problems and solve them, to gain experience with our own rights and wrongs. This paper will give a brief overview of what has been done so far, on experimental facilities and hardware that could support space system development, including a Brayton cycle test facility, Tesla turbine testing, and Stirling engine development and modeling. Our great problem today is lack of human resources. To attend that problem we are starting a new graduate program that will allow overcoming that, given the proper time frame. (author)
The NASA In-Space Propulsion Technology Project, Products, and Mission Applicability
Anderson, David J.; Pencil, Eric; Liou, Larry; Dankanich, John; Munk, Michelle M.; Kremic, Tibor
2009-01-01
The In-Space Propulsion Technology (ISPT) Project, funded by NASA s Science Mission Directorate (SMD), is continuing to invest in propulsion technologies that will enable or enhance NASA robotic science missions. This overview provides development status, near-term mission benefits, applicability, and availability of in-space propulsion technologies in the areas of aerocapture, electric propulsion, advanced chemical thrusters, and systems analysis tools. Aerocapture investments improved: guidance, navigation, and control models of blunt-body rigid aeroshells; atmospheric models for Earth, Titan, Mars, and Venus; and models for aerothermal effects. Investments in electric propulsion technologies focused on completing NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6 to 7 kW throttle-able gridded ion system. The project is also concluding its High Voltage Hall Accelerator (HiVHAC) mid-term product specifically designed for a low-cost electric propulsion option. The primary chemical propulsion investment is on the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. The project is also delivering products to assist technology infusion and quantify mission applicability and benefits through mission analysis and tools. In-space propulsion technologies are applicable, and potentially enabling for flagship destinations currently under evaluation, as well as having broad applicability to future Discovery and New Frontiers mission solicitations.
Upper ankle joint space detection on low contrast intraoperative fluoroscopic C-arm projections
Thomas, Sarina; Schnetzke, Marc; Brehler, Michael; Swartman, Benedict; Vetter, Sven; Franke, Jochen; Grützner, Paul A.; Meinzer, Hans-Peter; Nolden, Marco
2017-03-01
Intraoperative mobile C-arm fluoroscopy is widely used for interventional verification in trauma surgery, high flexibility combined with low cost being the main advantages of the method. However, the lack of global device-to- patient orientation is challenging, when comparing the acquired data to other intrapatient datasets. In upper ankle joint fracture reduction accompanied with an unstable syndesmosis, a comparison to the unfractured contralateral site is helpful for verification of the reduction result. To reduce dose and operation time, our approach aims at the comparison of single projections of the unfractured ankle with volumetric images of the reduced fracture. For precise assessment, a pre-alignment of both datasets is a crucial step. We propose a contour extraction pipeline to estimate the joint space location for a prealignment of fluoroscopic C-arm projections containing the upper ankle joint. A quadtree-based hierarchical variance comparison extracts potential feature points and a Hough transform is applied to identify bone shaft lines together with the tibiotalar joint space. By using this information we can define the coarse orientation of the projections independent from the ankle pose during acquisition in order to align those images to the volume of the fractured ankle. The proposed method was evaluated on thirteen cadaveric datasets consisting of 100 projections each with manually adjusted image planes by three trauma surgeons. The results show that the method can be used to detect the joint space orientation. The correlation between angle deviation and anatomical projection direction gives valuable input on the acquisition direction for future clinical experiments.
Project for the Space Science in Moscow State University of Geodesy and Cartography (MIIGAiK)
Semenov, M.; Oberst, J.; Malinnikov, V.; Shingareva, K.; Grechishchev, A.; Karachevtseva, I.; Konopikhin, A.
2012-04-01
Introduction: Based on the proposal call of the Government of Russian Federation 40 of international scientists came to Russia for developing and support-ing research capabilities of national educational institutions. Moscow State University of Geodesy and Cartography (MIIGAiK) and invited scientist Prof. Dr. Jurgen Oberst were awarded a grant to establish a capable research facility concerned with Planetary Geodesy, Cartography and Space Exploration. Objectives: The goals of the project are to build laboratory infrastructure, and suitable capability for MIIGAiK to participate in the planning, execution and analyses of data from future Russian planetary mis-sions and also to integrate into the international science community. Other important tasks are to develop an attractive work place and job opportunities for planetary geodesy and cartography students. For this purposes new MIIGAiK Extraterrestrial Laboratory (MExLab) was organized. We involved professors, researchers, PhD students in to the projects of Moon and planets exploration at the new level of Russian Space Science development. Main results: MExLab team prepare data for upcom-ing Russian space missions, such as LUNA-GLOB and LUNA-RESOURSE. We established cooperation with Russian and international partners (IKI, ESA, DLR, and foreign Universities) and actively participated in international conferences and workshops. Future works: For the future science development we investigated the old Soviet Archives and received the access to the telemetry data of the Moon rovers Lunokhod-1 and Lunokhod-2. That data will be used in education purposes and could be the perfect base for the analysis, development and support in new Russian and international missions and especially Moon exploration projects. MExLab is open to cooperate and make the consortiums for science projects for the Moon and planets exploration. Acknowledgement: Works are funded by the Rus-sian Government (Project name: "Geodesy, cartography and the
NASA Systems Autonomy Demonstration Project - Development of Space Station automation technology
Bull, John S.; Brown, Richard; Friedland, Peter; Wong, Carla M.; Bates, William
1987-01-01
A 1984 Congressional expansion of the 1958 National Aeronautics and Space Act mandated that NASA conduct programs, as part of the Space Station program, which will yield the U.S. material benefits, particularly in the areas of advanced automation and robotics systems. Demonstration programs are scheduled for automated systems such as the thermal control, expert system coordination of Station subsystems, and automation of multiple subsystems. The programs focus the R&D efforts and provide a gateway for transfer of technology to industry. The NASA Office of Aeronautics and Space Technology is responsible for directing, funding and evaluating the Systems Autonomy Demonstration Project, which will include simulated interactions between novice personnel and astronauts and several automated, expert subsystems to explore the effectiveness of the man-machine interface being developed. Features and progress on the TEXSYS prototype thermal control system expert system are outlined.
Public channel cryptography: chaos synchronization and Hilbert's tenth problem.
Kanter, Ido; Kopelowitz, Evi; Kinzel, Wolfgang
2008-08-22
The synchronization process of two mutually delayed coupled deterministic chaotic maps is demonstrated both analytically and numerically. The synchronization is preserved when the mutually transmitted signals are concealed by two commutative private filters, a convolution of the truncated time-delayed output signals or some powers of the delayed output signals. The task of a passive attacker is mapped onto Hilbert's tenth problem, solving a set of nonlinear Diophantine equations, which was proven to be in the class of NP-complete problems [problems that are both NP (verifiable in nondeterministic polynomial time) and NP-hard (any NP problem can be translated into this problem)]. This bridge between nonlinear dynamics and NP-complete problems opens a horizon for new types of secure public-channel protocols.
Martin, J. C.; Davidson, Kris; Koppelman, M. D.
2006-12-01
During the past decade η Car has brightened markedly, possibly indicating a change of state. Here we summarize photometry gathered by the Hubble Space Telescope (HST) as part of the HST Treasury Project on this object. Our data include Space Telescope Imaging Spectrograph (STIS) CCD acquisition images, Advanced Camera for Surveys HRC images in four filters, and synthetic photometry in flux-calibrated STIS spectra. The HST's spatial resolution allows us to examine the central star separate from the bright circumstellar ejecta. Its apparent brightness continued to increase briskly during 2002-2006, especially after the mid-2003 spectroscopic event. If this trend continues, the central star will soon become brighter than its ejecta, quite different from the state that existed only a few years ago. One precedent may be the rapid change observed in 1938-1953. We conjecture that the star's mass-loss rate has been decreasing throughout the past century. This research was conducted as part of the η Car Hubble Space Telescope Treasury project via grant GO-9973 from the Space Telescope Science Institute. HST is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts.
Optimized image acquisition for breast tomosynthesis in projection and reconstruction space
International Nuclear Information System (INIS)
Chawla, Amarpreet S.; Lo, Joseph Y.; Baker, Jay A.; Samei, Ehsan
2009-01-01
Breast tomosynthesis has been an exciting new development in the field of breast imaging. While the diagnostic improvement via tomosynthesis is notable, the full potential of tomosynthesis has not yet been realized. This may be attributed to the dependency of the diagnostic quality of tomosynthesis on multiple variables, each of which needs to be optimized. Those include dose, number of angular projections, and the total angular span of those projections. In this study, the authors investigated the effects of these acquisition parameters on the overall diagnostic image quality of breast tomosynthesis in both the projection and reconstruction space. Five mastectomy specimens were imaged using a prototype tomosynthesis system. 25 angular projections of each specimen were acquired at 6.2 times typical single-view clinical dose level. Images at lower dose levels were then simulated using a noise modification routine. Each projection image was supplemented with 84 simulated 3 mm 3D lesions embedded at the center of 84 nonoverlapping ROIs. The projection images were then reconstructed using a filtered backprojection algorithm at different combinations of acquisition parameters to investigate which of the many possible combinations maximizes the performance. Performance was evaluated in terms of a Laguerre-Gauss channelized Hotelling observer model-based measure of lesion detectability. The analysis was also performed without reconstruction by combining the model results from projection images using Bayesian decision fusion algorithm. The effect of acquisition parameters on projection images and reconstructed slices were then compared to derive an optimization rule for tomosynthesis. The results indicated that projection images yield comparable but higher performance than reconstructed images. Both modes, however, offered similar trends: Performance improved with an increase in the total acquisition dose level and the angular span. Using a constant dose level and angular
Regularization methods in Banach spaces
Schuster, Thomas; Hofmann, Bernd; Kazimierski, Kamil S
2012-01-01
Regularization methods aimed at finding stable approximate solutions are a necessary tool to tackle inverse and ill-posed problems. Usually the mathematical model of an inverse problem consists of an operator equation of the first kind and often the associated forward operator acts between Hilbert spaces. However, for numerous problems the reasons for using a Hilbert space setting seem to be based rather on conventions than on an approprimate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, sparsity constraints using general Lp-norms or the B
Instanton tunneling for de Sitter space with real projective spatial sections
Energy Technology Data Exchange (ETDEWEB)
Ong, Yen Chin [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Yeom, Dong-han, E-mail: ongyenchin@sjtu.edu.cn, E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)
2017-04-01
The physics of tunneling from one spacetime to another is often understood in terms of instantons. For some instantons, it was recently shown in the literature that there are two complementary ''interpretations'' for their analytic continuations. Dubbed ''something-to-something'' and ''nothing-to-something'' interpretations, respectively, the former involves situation in which the initial and final hypersurfaces are connected by a Euclidean manifold, whereas the initial and final hypersurfaces in the latter case are not connected in such a way. We consider a de Sitter space with real projective space RP{sup 3} spatial sections, as was originally understood by de Sitter himself. This original version of de Sitter space has several advantages over the usual de Sitter space with S{sup 3} spatial sections. In particular, the interpretation of the de Sitter entropy as entanglement entropy is much more natural. We discuss the subtleties involved in the tunneling of such a de Sitter space.
SPADA: a project to study the effectiveness of shielding materials in space
International Nuclear Information System (INIS)
Pugliese, M.; Casolino, M.; Cerciello, V.
2008-01-01
The SPADA (SPAce Dosimetry for Astronauts) project is a part of an extensive teamwork that aims to optimize shielding solutions against space radiation. Shielding is indeed all irreplaceable tool to reduce, exposure of crews of future Moon and Mars missions. We concentrated our studies on two flexible materials, Kevlar (R) and Nextel (R), because of their ability to protect space infrastructure from micro meteoroids measured radiation hardness of these shielding materials and compared to polyethylene, generally acknowledged as the most effective space radiation shield with practical applications in spacecraft. Both flight test (on the International Space Station and on the Russian FOTON M3 rocket), with passive dosimeters and accelerator-based experiments have been performed. Accelerator tests using high-energy Fe ions have demonstrated that Kevlar is almost as effective as polyethylene in shielding heavy ions, while Nextel is a poor shield against, high-charge and -energy particles. Preliminary results from spaceflight, however, show that for the radiation environment ill low-Earth orbit. dominated by trapped protons, thin shields of Kevlar and Nextel provide limited reduction.
Miller, R. H.; Minsky, M. L.; Smith, D. B. S.
1982-01-01
Applications of automation, robotics, and machine intelligence systems (ARAMIS) to space activities and their related ground support functions are studied, so that informed decisions can be made on which aspects of ARAMIS to develop. The specific tasks which will be required by future space project tasks are identified and the relative merits of these options are evaluated. The ARAMIS options defined and researched span the range from fully human to fully machine, including a number of intermediate options (e.g., humans assisted by computers, and various levels of teleoperation). By including this spectrum, the study searches for the optimum mix of humans and machines for space project tasks.
Projected quasiparticle theory for molecular electronic structure
Scuseria, Gustavo E.; Jiménez-Hoyos, Carlos A.; Henderson, Thomas M.; Samanta, Kousik; Ellis, Jason K.
2011-09-01
We derive and implement symmetry-projected Hartree-Fock-Bogoliubov (HFB) equations and apply them to the molecular electronic structure problem. All symmetries (particle number, spin, spatial, and complex conjugation) are deliberately broken and restored in a self-consistent variation-after-projection approach. We show that the resulting method yields a comprehensive black-box treatment of static correlations with effective one-electron (mean-field) computational cost. The ensuing wave function is of multireference character and permeates the entire Hilbert space of the problem. The energy expression is different from regular HFB theory but remains a functional of an independent quasiparticle density matrix. All reduced density matrices are expressible as an integration of transition density matrices over a gauge grid. We present several proof-of-principle examples demonstrating the compelling power of projected quasiparticle theory for quantum chemistry.
SpaceScience@Home: Authentic Research Projects that Use Citizen Scientists
Méndez, B. J. H.
2008-06-01
In recent years, several space science research projects have enlisted the help of large numbers of non-professional volunteers, ``citizen scientists'', to aid in performing tasks that are critical to a project, but require more person-time (or computing time) than a small professional research team can practically perform themselves. Examples of such projects include SETI@home, which uses time from volunteers computers to process radio-telescope observation looking for signals originating from extra-terrestrial intelligences; Clickworkers, which asks volunteers to review images of the surface of Mars to identify craters; Spacewatch, which used volunteers to review astronomical telescopic images of the sky to identify streaks made by possible Near Earth Asteroids; and Stardust@home, which asks volunteers to review ``focus movies'' taken of the Stardust interstellar dust aerogel collector to search for possible impacts from interstellar dust particles. We shall describe these and other similar projects and discuss lessons learned from carrying out such projects, including the educational opportunities they create.
Analysis of Discrete L2 Projection on Polynomial Spaces with Random Evaluations
Migliorati, Giovanni
2014-03-05
We analyze the problem of approximating a multivariate function by discrete least-squares projection on a polynomial space starting from random, noise-free observations. An area of possible application of such technique is uncertainty quantification for computational models. We prove an optimal convergence estimate, up to a logarithmic factor, in the univariate case, when the observation points are sampled in a bounded domain from a probability density function bounded away from zero and bounded from above, provided the number of samples scales quadratically with the dimension of the polynomial space. Optimality is meant in the sense that the weighted L2 norm of the error committed by the random discrete projection is bounded with high probability from above by the best L∞ error achievable in the given polynomial space, up to logarithmic factors. Several numerical tests are presented in both the univariate and multivariate cases, confirming our theoretical estimates. The numerical tests also clarify how the convergence rate depends on the number of sampling points, on the polynomial degree, and on the smoothness of the target function. © 2014 SFoCM.
Analysis of Discrete L2 Projection on Polynomial Spaces with Random Evaluations
Migliorati, Giovanni; Nobile, Fabio; von Schwerin, Erik; Tempone, Raul
2014-01-01
We analyze the problem of approximating a multivariate function by discrete least-squares projection on a polynomial space starting from random, noise-free observations. An area of possible application of such technique is uncertainty quantification for computational models. We prove an optimal convergence estimate, up to a logarithmic factor, in the univariate case, when the observation points are sampled in a bounded domain from a probability density function bounded away from zero and bounded from above, provided the number of samples scales quadratically with the dimension of the polynomial space. Optimality is meant in the sense that the weighted L2 norm of the error committed by the random discrete projection is bounded with high probability from above by the best L∞ error achievable in the given polynomial space, up to logarithmic factors. Several numerical tests are presented in both the univariate and multivariate cases, confirming our theoretical estimates. The numerical tests also clarify how the convergence rate depends on the number of sampling points, on the polynomial degree, and on the smoothness of the target function. © 2014 SFoCM.
Hilbert-Schmidt expansion for the nucleon-deuteron scattering amplitude
International Nuclear Information System (INIS)
Moeller, K.; Narodetskii, I.M.
1983-01-01
The Hilbert-Schmidt method is used to sum the divergent iterative series for the partial amplitudes of nucleon-deuteron scattering in the energy region above the deuteron breakup threshold. It is observed that the Hilbert-Schmidt series for the partial amplitudes themselves diverges, which is due to the closeness of the logarithmic singularities. But if the first iterations in the series for multiple scattering are subtracted from the amplitude, the Hilbert-Schmidt series for the remainder converges rapidly. The final answer obtained in the present paper is in excellent agreement with the results obtained in exact calculations
Application of Arbitrary-Order Hilbert Spectral Analysis to Passive Scalar Turbulence
International Nuclear Information System (INIS)
Huang, Y X; Lu, Z M; Liu, Y L; Schmitt, F G; Gagne, Y
2011-01-01
In previous work [Huang et al., PRE 82, 26319, 2010], we found that the passive scalar turbulence field maybe less intermittent than what we believed before. Here we apply the same method, namely arbitrary-order Hilbert spectral analysis, to a passive scalar (temperature) time series with a Taylor's microscale Reynolds number Re λ ≅ 3000. We find that with increasing Reynolds number, the discrepancy of scaling exponents between Hilbert ξ θ (q) and Kolmogorov-Obukhov-Corrsin (KOC) theory is increasing, and consequently the discrepancy between Hilbert and structure function could disappear at infinite Reynolds number.
Monte Carlo simulations for the space radiation superconducting shield project (SR2S).
Vuolo, M; Giraudo, M; Musenich, R; Calvelli, V; Ambroglini, F; Burger, W J; Battiston, R
2016-02-01
Astronauts on deep-space long-duration missions will be exposed for long time to galactic cosmic rays (GCR) and Solar Particle Events (SPE). The exposure to space radiation could lead to both acute and late effects in the crew members and well defined countermeasures do not exist nowadays. The simplest solution given by optimized passive shielding is not able to reduce the dose deposited by GCRs below the actual dose limits, therefore other solutions, such as active shielding employing superconducting magnetic fields, are under study. In the framework of the EU FP7 SR2S Project - Space Radiation Superconducting Shield--a toroidal magnetic system based on MgB2 superconductors has been analyzed through detailed Monte Carlo simulations using Geant4 interface GRAS. Spacecraft and magnets were modeled together with a simplified mechanical structure supporting the coils. Radiation transport through magnetic fields and materials was simulated for a deep-space mission scenario, considering for the first time the effect of secondary particles produced in the passage of space radiation through the active shielding and spacecraft structures. When modeling the structures supporting the active shielding systems and the habitat, the radiation protection efficiency of the magnetic field is severely decreasing compared to the one reported in previous studies, when only the magnetic field was modeled around the crew. This is due to the large production of secondary radiation taking place in the material surrounding the habitat. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.
On deformation of foliations with a center in the projective space
Directory of Open Access Journals (Sweden)
MOVASATI HOSSEIN
2001-01-01
Full Text Available Let be a foliation in the projective space of dimension two with a first integral of the type , where F and G are two polynomials on an affine coordinate, = and g.c.d.(p, q = 1. Let z be a nondegenerate critical point of , which is a center singularity of , and be a deformation of in the space of foliations of degree deg( such that its unique deformed singularity near z persists in being a center. We will prove that the foliation has a first integral of the same type of . Using the arguments of the proof of this result we will give a lower bound for the maximum number of limit cycles of real polynomial differential equations of a fixed degree in the real plane.
Rodríguez, Jacobo; Laverón-Simavilla, Ana; del Cura, Juan M.; Ezquerro, José M.; Lapuerta, Victoria; Cordero-Gracia, Marta
2015-10-01
This work describes the innovation activities performed in the field of space education since the academic year 2009/10 at the Technical University of Madrid (UPM), in collaboration with the Spanish User Support and Operations Center (E-USOC), the center assigned by the European Space Agency (ESA) in Spain to support the operations of scientific experiments on board the International Space Station. These activities have been integrated within the last year of the UPM Aerospace Engineering degree. A laboratory has been created, where students have to validate and integrate the subsystems of a microsatellite using demonstrator satellites. In parallel, the students participate in a Project Based Learning (PBL) training process in which they work in groups to develop the conceptual design of a space mission. One student in each group takes the role of project manager, another one is responsible for the mission design and the rest are each responsible for the design of one of the satellite subsystems. A ground station has also been set up with the help of students developing their final thesis, which will allow future students to perform training sessions and learn how to communicate with satellites, how to receive telemetry and how to process the data. Several surveys have been conducted along two academic years to evaluate the impact of these techniques in engineering learning. The surveys evaluate the acquisition of specific and generic competences, as well as the students' degree of satisfaction with respect to the use of these learning methodologies. The results of the surveys and the perception of the lecturers show that PBL encourages students' motivation and improves their results. They not only acquire better technical training, but also improve their transversal skills. It is also pointed out that this methodology requires more dedication from lecturers than traditional methods.
Toeplitz Operators, Pseudo-Homogeneous Symbols, and Moment Maps on the Complex Projective Space
Directory of Open Access Journals (Sweden)
Miguel Antonio Morales-Ramos
2017-01-01
Full Text Available Following previous works for the unit ball due to Nikolai Vasilevski, we define quasi-radial pseudo-homogeneous symbols on the projective space and obtain the corresponding commutativity results for Toeplitz operators. A geometric interpretation of these symbols in terms of moment maps is developed. This leads us to the introduction of a new family of symbols, extended pseudo-homogeneous, that provide larger commutative Banach algebras generated by Toeplitz operators. This family of symbols provides new commutative Banach algebras generated by Toeplitz operators on the unit ball.
Automation and robotics for the Space Exploration Initiative: Results from Project Outreach
Gonzales, D.; Criswell, D.; Heer, E.
1991-01-01
A total of 52 submissions were received in the Automation and Robotics (A&R) area during Project Outreach. About half of the submissions (24) contained concepts that were judged to have high utility for the Space Exploration Initiative (SEI) and were analyzed further by the robotics panel. These 24 submissions are analyzed here. Three types of robots were proposed in the high scoring submissions: structured task robots (STRs), teleoperated robots (TORs), and surface exploration robots. Several advanced TOR control interface technologies were proposed in the submissions. Many A&R concepts or potential standards were presented or alluded to by the submitters, but few specific technologies or systems were suggested.
International Nuclear Information System (INIS)
Maraman, W.J.
1980-05-01
This formal monthly report covers the studies related to the use of 238 PuO 2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are: General-Purpose Heat Source Development and Space Nuclear Safety and Fuels. Most of the studies discussed here are of a continuing nature. Results and conclusions described may change as the work continues. Published reference to the results cited in this report should not be made without the explicit permission of the person in charge of the work
Directory of Open Access Journals (Sweden)
Xin Xu
2009-03-01
Full Text Available The significant economic contributions of the tourism industry in recent years impose an unprecedented force for data mining and machine learning methods to analyze tourism data. The intrinsic problems of raw data in tourism are largely related to the complexity, noise and nonlinearity in the data that may introduce many challenges for the existing data mining techniques such as rough sets and neural networks. In this paper, a novel method using SVM- based classification with two nonlinear feature projection techniques is proposed for tourism data analysis. The first feature projection method is based on ISOMAP (Isometric Feature Mapping, which is a class of manifold learning approaches for dimension reduction. By making use of ISOMAP, part of the noisy data can be identified and the classification accuracy of SVMs can be improved by appropriately discarding the noisy training data. The second feature projection method is a probabilistic space mapping technique for scale transformation. Experimental results on expenditure data of business travelers show that the proposed method can improve prediction performance both in terms of testing accuracy and statistical coincidence. In addition, both of the feature projection methods are helpful to reduce the training time of SVMs.
Migliorati, G.; Nobile, F.; von Schwerin, E.; Tempone, Raul
2013-01-01
In this work we consider the random discrete L^2 projection on polynomial spaces (hereafter RDP) for the approximation of scalar quantities of interest (QOIs) related to the solution of a partial differential equation model with random input
Phase difference estimation method based on data extension and Hilbert transform
International Nuclear Information System (INIS)
Shen, Yan-lin; Tu, Ya-qing; Chen, Lin-jun; Shen, Ting-ao
2015-01-01
To improve the precision and anti-interference performance of phase difference estimation for non-integer periods of sampling signals, a phase difference estimation method based on data extension and Hilbert transform is proposed. Estimated phase difference is obtained by means of data extension, Hilbert transform, cross-correlation, auto-correlation, and weighted phase average. Theoretical analysis shows that the proposed method suppresses the end effects of Hilbert transform effectively. The results of simulations and field experiments demonstrate that the proposed method improves the anti-interference performance of phase difference estimation and has better performance of phase difference estimation than the correlation, Hilbert transform, and data extension-based correlation methods, which contribute to improving the measurement precision of the Coriolis mass flowmeter. (paper)
Integrated reconfigurable photonic filters based on interferometric fractional Hilbert transforms.
Sima, C; Cai, B; Liu, B; Gao, Y; Yu, Y; Gates, J C; Zervas, M N; Smith, P G R; Liu, D
2017-10-01
In this paper, we present integrated reconfigurable photonic filters using fractional Hilbert transformers (FrHTs) and optical phase tuning structure within the silica-on-silicon platform. The proposed structure, including grating-based FrHTs, an X-coupler, and a pair of thermal tuning filaments, is fabricated through the direct UV grating writing technique. The thermal tuning effect is realized by the controllable microheaters located on the two arms of the X-coupler. We investigate the 200 GHz maximum bandwidth photonic FrHTs based on apodized planar Bragg gratings, and analyze the reflection spectrum responses. Through device integration and thermal modulation, the device could operate as photonic notch filters with 5 GHz linewidth and controllable single sideband suppression filters with measured 12 dB suppression ratio. A 50 GHz instantaneous frequency measuring system using this device is also schematically proposed and analyzed with potential 3 dB measurement improvement. The device could be configured with these multiple functions according to need. The reconfigurable structure has great potential in ultrafast all-optical signal processing fields.
International Nuclear Information System (INIS)
Thas, Koen
2006-01-01
In Am. Math. Monthly (73 1-23 (1966)), Kac asked his famous question 'Can one hear the shape of a drum?', which was eventually answered negatively in Gordon et al (1992 Invent. Math. 110 1-22) by construction of planar isospectral pairs. Giraud (2005 J. Phys. A: Math. Gen. 38 L477-83) observed that most of the known examples can be generated from solutions of a certain equation which involves a set of involutions of an n-dimensional projective space over some finite field. He then generated all possible solutions for n = 2, when the involutions fix the same number of points. In Thas (2006 J. Phys. A: Math. Gen. 39 L385-8) we showed that no other examples arise for any other dimension, still assuming that the involutions fix the same number of points. In this paper we study the problem for involutions not necessarily fixing the same number of points, and solve the problem completely
Majewski M.; Magalas L.B.
2015-01-01
The parametric OMI (Optimization in Multiple Intervals), the Yoshida-Magalas (YM) and a novel Hilbert-twin (H-twin) methods are advocated for computing the logarithmic decrement in the field of internal friction and mechanical spectroscopy of solids. It is shown that dispersion in experimental points results mainly from the selection of the computing methods, the number of oscillations, and noise. It is demonstrated that conventional Hilbert transform method suffers from high dispersion in in...
Application of Hilbert-Huang Transform in Generating Spectrum-Compatible Earthquake Time Histories
Ni, Shun-Hao; Xie, Wei-Chau; Pandey, Mahesh
2011-01-01
Spectrum-compatible earthquake time histories have been widely used for seismic analysis and design. In this paper, a data processing method, Hilbert-Huang transform, is applied to generate earthquake time histories compatible with the target seismic design spectra based on multiple actual earthquake records. Each actual earthquake record is decomposed into several components of time-dependent amplitude and frequency by Hilbert-Huang transform. The spectrum-compatible earthquake time history ...
Mazur, J. E.; Guild, T. B.; Crain, W.; Crain, S.; Holker, D.; Quintana, S.; O'Brien, T. P., III; Kelly, M. A.; Barnes, R. J.; Sotirelis, T.
2017-12-01
The Responsive Environmental Assessment Commercial Hosting (REACH) project uses radiation dosimeters on a commercial satellite constellation in low Earth orbit to provide unprecedented spatial and time sampling of space weather radiation hazards. The spatial and time scales of natural space radiation environments coupled with constraints for the hosting accommodation drove the instrumentation requirements and the plan for the final orbital constellation. The project has delivered a total of thirty two radiation dosimeter instruments for launch with each instrument containing two dosimeters with different passive shielding and electronic thresholds to address proton-induced single-event effects, vehicle charging, and total ionizing dose. There are two REACH instruments currently operating with four more planned for launch by the time of the 2017 meeting. Our aim is to field a long-lived system of highly-capable radiation detectors to monitor the hazards of single-event effects, total ionizing dose, and spacecraft charging with maximized spatial coverage and with minimal time latency. We combined a robust detection technology with a commercial satellite hosting to produce a new demonstration for satellite situational awareness and for other engineering and science applications.
Wheeler, R. M.; Sager, J. C.; Prince, R. P.; Knott, W. M.; Mackowiak, C. L.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Peterson, B. V.; Goins, G. D.
2003-01-01
The use of plants for bioregenerative life support for space missions was first studied by the US Air Force in the 1950s and 1960s. Extensive testing was also conducted from the 1960s through the 1980s by Russian researchers located at the Institute of Biophysics in Krasnoyarsk, Siberia, and the Institute for Biomedical Problems in Moscow. NASA initiated bioregenerative research in the 1960s (e.g., Hydrogenomonas) but this research did not include testing with plants until about 1980, with the start of the Controlled Ecological Life Support System (CELSS) Program. The NASA CELSS research was carried out at universities, private corporations, and NASA field centers, including Kennedy Space Center (KSC). The project at KSC began in 1985 and was called the CELSS Breadboard Project to indicate the capability for plugging in and testing various life support technologies; this name has since been dropped but bioregenerative testing at KSC has continued to the present under the NASA s Advanced Life Support (ALS) Program. A primary objective of the KSC testing was to conduct pre-integration tests with plants (crops) in a large, atmospherically closed test chamber called the Biomass Production Chamber (BPC). Test protocols for the BPC were based on observations and growing procedures developed by university investigators, as well as procedures developed in plant growth chamber studies at KSC. Growth chamber studies to support BPC testing focused on plant responses to different carbon dioxide (CO2) concentrations, different spectral qualities from various electric lamps, and nutrient film hydroponic culture techniques.
To quantum averages through asymptotic expansion of classical averages on infinite-dimensional space
International Nuclear Information System (INIS)
Khrennikov, Andrei
2007-01-01
We study asymptotic expansions of Gaussian integrals of analytic functionals on infinite-dimensional spaces (Hilbert and nuclear Frechet). We obtain an asymptotic equality coupling the Gaussian integral and the trace of the composition of scaling of the covariation operator of a Gaussian measure and the second (Frechet) derivative of a functional. In this way we couple classical average (given by an infinite-dimensional Gaussian integral) and quantum average (given by the von Neumann trace formula). We can interpret this mathematical construction as a procedure of 'dequantization' of quantum mechanics. We represent quantum mechanics as an asymptotic projection of classical statistical mechanics with infinite-dimensional phase space. This space can be represented as the space of classical fields, so quantum mechanics is represented as a projection of 'prequantum classical statistical field theory'
Status and Mission Applicability of NASA's In-Space Propulsion Technology Project
Anderson, David J.; Munk, Michelle M.; Dankanich, John; Pencil, Eric; Liou, Larry
2009-01-01
The In-Space Propulsion Technology (ISPT) project develops propulsion technologies that will enable or enhance NASA robotic science missions. Since 2001, the ISPT project developed and delivered products to assist technology infusion and quantify mission applicability and benefits through mission analysis and tools. These in-space propulsion technologies are applicable, and potentially enabling for flagship destinations currently under evaluation, as well as having broad applicability to future Discovery and New Frontiers mission solicitations. This paper provides status of the technology development, near-term mission benefits, applicability, and availability of in-space propulsion technologies in the areas of advanced chemical thrusters, electric propulsion, aerocapture, and systems analysis tools. The current chemical propulsion investment is on the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. Investments in electric propulsion technologies focused on completing NASA's Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system, and the High Voltage Hall Accelerator (HiVHAC) thruster, which is a mid-term product specifically designed for a low-cost electric propulsion option. Aerocapture investments developed a family of thermal protections system materials and structures; guidance, navigation, and control models of blunt-body rigid aeroshells; atmospheric models for Earth, Titan, Mars and Venus; and models for aerothermal effects. In 2009 ISPT started the development of propulsion technologies that would enable future sample return missions. The paper describes the ISPT project's future focus on propulsion for sample return missions. The future technology development areas for ISPT is: Planetary Ascent Vehicles (PAV), with a Mars Ascent Vehicle (MAV) being the initial development focus; multi-mission technologies for Earth Entry Vehicles (MMEEV) needed
International Nuclear Information System (INIS)
Bonora, Loriano; Bytsenko, Andrey; Elizalde, Emilio
2012-01-01
This review paper contains a concise introduction to highest weight representations of infinite-dimensional Lie algebras, vertex operator algebras and Hilbert schemes of points, together with their physical applications to elliptic genera of superconformal quantum mechanics and superstring models. The common link of all these concepts and of the many examples considered in this paper is to be found in a very important feature of the theory of infinite-dimensional Lie algebras: the modular properties of the characters (generating functions) of certain representations. The characters of the highest weight modules represent the holomorphic parts of the partition functions on the torus for the corresponding conformal field theories. We discuss the role of the unimodular (and modular) groups and the (Selberg-type) Ruelle spectral functions of hyperbolic geometry in the calculation of elliptic genera and associated q-series. For mathematicians, elliptic genera are commonly associated with new mathematical invariants for spaces, while for physicists elliptic genera are one-loop string partition function. (Therefore, they are applicable, for instance, to topological Casimir effect calculations.) We show that elliptic genera can be conveniently transformed into product expressions, which can then inherit the homology properties of appropriate polygraded Lie algebras. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker’s 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’. (review)
Hilbert's 'Foundations of Physics': Gravitation and electromagnetism within the axiomatic method
Brading, K. A.; Ryckman, T. A.
2008-01-01
In November and December 1915, Hilbert presented two communications to the Göttingen Academy of Sciences under the common title 'The Foundations of Physics'. Versions of each eventually appeared in the Nachrichten of the Academy. Hilbert's first communication has received significant reconsideration in recent years, following the discovery of printer's proofs of this paper, dated 6 December 1915. The focus has been primarily on the 'priority dispute' over the Einstein field equations. Our contention, in contrast, is that the discovery of the December proofs makes it possible to see the thematic linkage between the material that Hilbert cut from the published version of the first communication and the content of the second, as published in 1917. The latter has been largely either disregarded or misinterpreted, and our aim is to show that (a) Hilbert's two communications should be regarded as part of a wider research program within the overarching framework of 'the axiomatic method' (as Hilbert expressly stated was the case), and (b) the second communication is a fine and coherent piece of work within this framework, whose principal aim is to address an apparent tension between general invariance and causality (in the precise sense of Cauchy determination), pinpointed in Theorem I of the first communication. This is not the same problem as that found in Einstein's 'hole argument'-something that, we argue, never confused Hilbert.
The NASA Space Place: A Plethora of Games, Projects, and Fun Facts for Celebrating Astronomy
Leon, N. J.; Fisher, D. K.
2008-12-01
out activities to tie in with the IYA April topic, Galaxies and the Distant Universe. The infrared Spitzer Space Telescope, as well as the Galaxy Evolution Explorer (GALEX) spacecraft are strongly represented on The Space Place web site, with interactive games, images, and crafts that explore the wonders of and latest discoveries about galaxies. In addition, in our mailings and other partner communications throughout the year, we will feature special activities and projects on spaceplace.nasa.gov, and suggest ways to use these resources in IYA-related events.
Space Science in Project SMART: A UNH High School Outreach Program
Smith, C. W.; Broad, L.; Goelzer, S.; Lessard, M.; Levergood, R.; Lugaz, N.; Moebius, E.; Schwadron, N.; Torbert, R. B.; Zhang, J.; Bloser, P. F.
2016-12-01
Every summer for the past 25 years the University of New Hampshire (UNH) has run a month-long, residential outreach program for high school students considering careers in mathematics, science, or engineering. Space science is one of the modules. Students work directly with UNH faculty performing original work with real spacecraft data and hardware and present the results of that effort at the end of the program. Recent research topics have included interplanetary waves and turbulence as recorded by the ACE and Voyager spacecraft, electromagnetic ion cyclotron (EMIC) waves seen by the RBSP spacecraft, interplanetary coronal mass ejections (ICME) acceleration and interstellar pickup ions as seen by the STEREO spacecraft, and prototyping CubeSat hardware. Student research efforts can provide useful results for future research efforts by the faculty while the students gain unique exposure to space physics and a science career. In addition, the students complete a team project. Since 2006, that project has been the construction and flight of a high-altitude balloon payload and instruments. The students typically build the instruments they fly. In the process, students learn circuit design and construction, microcontroller programming, and core atmospheric and space science. Our payload design has evolved significantly since the first flight of a simple rectangular box and now involves a stable descent vehicle that does not require a parachute, an on-board flight control computer, in-flight autonomous control and data acquisition of multiple student-built instruments, and real-time camera images sent to ground. This is a program that can be used as a model for other schools to follow and that high schools can initiate. More information can be found at .
Science Students Creating Hybrid Spaces when Engaging in an Expo Investigation Project
Ramnarain, Umesh; de Beer, Josef
2013-02-01
In this paper, we report on the experiences of three 9th-grade South African students (13-14 years) in doing open science investigation projects for a science expo. A particular focus of this study was the manner in which these students merge the world of school science with their social world to create a hybrid space by appropriating knowledge and resources of the school and home. Within this hybrid space they experienced a deeper, more meaningful and authentic engagement in science practical work. This hybrid space redefined the landscape of the science learning experience for these students, as they could derive the twofold benefit of appropriating support when necessary and at the same time maintain their autonomy over the investigation. For South Africa and quite probably other countries; these findings serve as a guideline as to how opportunities can be created for students to do open science investigations, against prevailing school factors such as large classes, a lack of physical resources, the lack of time for practical work and the demands of syllabus coverage.
Sinha, Shriprakash
2017-12-04
Ever since the accidental discovery of Wingless [Sharma R.P., Drosophila information service, 1973, 50, p 134], research in the field of Wnt signaling pathway has taken significant strides in wet lab experiments and various cancer clinical trials, augmented by recent developments in advanced computational modeling of the pathway. Information rich gene expression profiles reveal various aspects of the signaling pathway and help in studying different issues simultaneously. Hitherto, not many computational studies exist which incorporate the simultaneous study of these issues. This manuscript ∙ explores the strength of contributing factors in the signaling pathway, ∙ analyzes the existing causal relations among the inter/extracellular factors effecting the pathway based on prior biological knowledge and ∙ investigates the deviations in fold changes in the recently found prevalence of psychophysical laws working in the pathway. To achieve this goal, local and global sensitivity analysis is conducted on the (non)linear responses between the factors obtained from static and time series expression profiles using the density (Hilbert-Schmidt Information Criterion) and variance (Sobol) based sensitivity indices. The results show the advantage of using density based indices over variance based indices mainly due to the former's employment of distance measures & the kernel trick via Reproducing kernel Hilbert space (RKHS) that capture nonlinear relations among various intra/extracellular factors of the pathway in a higher dimensional space. In time series data, using these indices it is now possible to observe where in time, which factors get influenced & contribute to the pathway, as changes in concentration of the other factors are made. This synergy of prior biological knowledge, sensitivity analysis & representations in higher dimensional spaces can facilitate in time based administration of target therapeutic drugs & reveal hidden biological information within
Mentoring Undergraduate Students through the Space Shuttle Hitchhiker GoldHELOX Project
Moody, J. Ward; Barnes, Jonathan; Roming, Peter; Durfee, Dallin; Campbell, Branton; Turley, Steve; Eastman, Paul
2015-01-01
In the late 1980s a team of four BYU undergraduate students designed a space-based telescope to image the sun in soft x-rays from 171-181 Angstroms to gain information on microflares and their relation to the corona-chromosphere transition region. The telescope used a near-normal incidence multi-layered mirror imaging onto film through a micro-channel plate. The system was capable of 1.0 sec time resolution and 2.5 arcsec spatial resolution. Aided by a NASA grant in 1991, a system was built and successfully tested in 1998 at Marshall Space Flight Center. Originally designed to be deployed from a Get-Away-Special (GAS) canister in the bay of a space shuttle, the good results of this test elevated GoldHelox to greater-priority Hitchhiker status. Even so technical and procedural difficulties delayed a launch until after 2003. Unfortunately after the Columbia re-entry break-up in February 2003, the Hitchhiker program was cancelled and the GoldHelox project ended.Well over 200 undergraduate students worked on GoldHelox. Many of these have since earned advanced degrees in a variety of technical fields. Several have gone on to work in the space industry, becoming NASA scientists and engineers with one becoming a PI on the Swift satellite. The broad range of talent on the team has included students majoring in physics, astronomy, mechanical engineering, electrical engineering, manufacturing engineering, design engineering, business and even English majors who have written technical and public relations documents. We report on lessons learned and the pitfalls and successes of this unique mentoring experience.
Coherent states in the fermionic Fock space
International Nuclear Information System (INIS)
Oeckl, Robert
2015-01-01
We construct the coherent states in the sense of Gilmore and Perelomov for the fermionic Fock space. Our treatment is from the outset adapted to the infinite-dimensional case. The fermionic Fock space becomes in this way a reproducing kernel Hilbert space of continuous holomorphic functions. (paper)
Seizure classification in EEG signals utilizing Hilbert-Huang transform
Directory of Open Access Journals (Sweden)
Abdulhay Enas W
2011-05-01
Full Text Available Abstract Background Classification method capable of recognizing abnormal activities of the brain functionality are either brain imaging or brain signal analysis. The abnormal activity of interest in this study is characterized by a disturbance caused by changes in neuronal electrochemical activity that results in abnormal synchronous discharges. The method aims at helping physicians discriminate between healthy and seizure electroencephalographic (EEG signals. Method Discrimination in this work is achieved by analyzing EEG signals obtained from freely accessible databases. MATLAB has been used to implement and test the proposed classification algorithm. The analysis in question presents a classification of normal and ictal activities using a feature relied on Hilbert-Huang Transform. Through this method, information related to the intrinsic functions contained in the EEG signal has been extracted to track the local amplitude and the frequency of the signal. Based on this local information, weighted frequencies are calculated and a comparison between ictal and seizure-free determinant intrinsic functions is then performed. Methods of comparison used are the t-test and the Euclidean clustering. Results The t-test results in a P-value Conclusion An original tool for EEG signal processing giving physicians the possibility to diagnose brain functionality abnormalities is presented in this paper. The proposed system bears the potential of providing several credible benefits such as fast diagnosis, high accuracy, good sensitivity and specificity, time saving and user friendly. Furthermore, the classification of mode mixing can be achieved using the extracted instantaneous information of every IMF, but it would be most likely a hard task if only the average value is used. Extra benefits of this proposed system include low cost, and ease of interface. All of that indicate the usefulness of the tool and its use as an efficient diagnostic tool.
Comments on the interacting Einstein-Hilbert drop
International Nuclear Information System (INIS)
Khanal, U.
2004-12-01
The bosonic internal co-ordinates of the Einstein-Hilbert drop is complexified to include U(1) gauge interaction. The equations of motion of the gauge fields are Maxwell equations. The EOM of the internal co-ordinates are elliptic under matter domination and hyperbolic under vacuum domination. These equations take on the familiar form of the wave equation of the interacting massless scalar field in any world spacetime that has the sum of its energy-momentum and Einstein tensors proportional to the induced metric. The reparametrization invariance of the worldtime can be used to identify it with the internal time. This results in a gauge condition that relates time to the curvature, gauge potential and energy-momentum. In gaussian normal co-ordinates of a constant curvature worldspace with real time, this condition translates into vanishing pressure, allowing a solution for the time dependence of the time-component of the vector potential. This potential has a simple pole at the origin of the complex time-plane, and another at a point on the imaginary axis. The singularity at the origin occurs only in the imaginary part of the potential. This potential in turn makes it possible to solve for the time dependence of the internal co-ordinates. Real internal co-ordinates have to be linear in worldtime. The complex internal co-ordinate also has two simple poles: one is at the same point on the imaginary axis as the potential; the other at infinity occurs only in the imaginary part. The origin turns out to be a regular point. (author)
Seizure classification in EEG signals utilizing Hilbert-Huang transform.
Oweis, Rami J; Abdulhay, Enas W
2011-05-24
Classification method capable of recognizing abnormal activities of the brain functionality are either brain imaging or brain signal analysis. The abnormal activity of interest in this study is characterized by a disturbance caused by changes in neuronal electrochemical activity that results in abnormal synchronous discharges. The method aims at helping physicians discriminate between healthy and seizure electroencephalographic (EEG) signals. Discrimination in this work is achieved by analyzing EEG signals obtained from freely accessible databases. MATLAB has been used to implement and test the proposed classification algorithm. The analysis in question presents a classification of normal and ictal activities using a feature relied on Hilbert-Huang Transform. Through this method, information related to the intrinsic functions contained in the EEG signal has been extracted to track the local amplitude and the frequency of the signal. Based on this local information, weighted frequencies are calculated and a comparison between ictal and seizure-free determinant intrinsic functions is then performed. Methods of comparison used are the t-test and the Euclidean clustering. The t-test results in a P-value with respect to its fast response and ease to use. An original tool for EEG signal processing giving physicians the possibility to diagnose brain functionality abnormalities is presented in this paper. The proposed system bears the potential of providing several credible benefits such as fast diagnosis, high accuracy, good sensitivity and specificity, time saving and user friendly. Furthermore, the classification of mode mixing can be achieved using the extracted instantaneous information of every IMF, but it would be most likely a hard task if only the average value is used. Extra benefits of this proposed system include low cost, and ease of interface. All of that indicate the usefulness of the tool and its use as an efficient diagnostic tool.
Directory of Open Access Journals (Sweden)
Mehmet PENPECİOĞLU
2013-04-01
Full Text Available With the rise of neo-liberalism, large-scale urban projects (LDPs have become a powerful mechanism of urban policy. Creating spaces of neo-liberal urbanization such as central business districts, tourism centers, gated residences and shopping malls, LDPs play a role not only in the reproduction of capital accumulation relations but also in the shift of urban political priorities towards the construction of neo-liberal hegemony. The construction of neo-liberal hegemony and the role played by LDPs in this process could not only be investigated by the analysis of capital accumulation. For such an investigation; the role of state and civil society actors in LDPs, their collaborative and conflictual relationships should be researched and their functions in hegemony should be revealed. In the case of Izmir’s two LDPs, namely the New City Center (NCC and Inciraltı Tourism Center (ITC projects, this study analyzes the relationship between the production of space and neo-liberal hegemony. In the NCC project, local governments, investors, local capital organizations and professional chambers collaborated and disseminated hegemonic discourse, which provided social support for the project. Through these relationships and discourses, the NCC project has become a hegemonic project for producing space and constructed neo-liberal hegemony over urban political priorities. In contrast to the NCC project, the ITC project saw no collaboration between state and organized civil society actors. The social opposition against the ITC project, initiated by professional chambers, has brought legal action against the ITC development plans in order to prevent their implementation. As a result, the ITC project did not acquire the consent of organized social groups and failed to become a hegemonic project for producing space.
Miller, Thomas
2007-01-01
The NASA Glenn Research Center (GRC), along with the Goddard Space Flight Center (GSFC), Jet Propulsion Laboratory (JPL), Johnson Space Center (JSC), Marshall Space Flight Center (MSFC), and industry partners, is leading a space-rated lithium-ion advanced development battery effort to support the vision for Exploration. This effort addresses the lithium-ion battery portion of the Energy Storage Project under the Exploration Technology Development Program. Key discussions focus on the lithium-ion cell component development activities, a common lithium-ion battery module, test and demonstration of charge/discharge cycle life performance and safety characterization. A review of the space-rated lithium-ion battery project will be presented highlighting the technical accomplishments during the past year.
The MY NASA DATA Project: Tools and a Collaboration Space for Knowledge Discovery
Chambers, L. H.; Alston, E. J.; Diones, D. D.; Moore, S. W.; Oots, P. C.; Phelps, C. S.
2006-05-01
The Atmospheric Science Data Center (ASDC) at NASA Langley Research Center is charged with serving a wide user community that is interested in its large data holdings in the areas of Aerosols, Clouds, Radiation Budget, and Tropospheric Chemistry. Most of the data holdings, however, are in large files with specialized data formats. The MY NASA DATA (mynasadata.larc.nasa.gov) project began in 2004, as part of the NASA Research, Education, and Applications Solutions Network (REASoN), in order to open this important resource to a broader community including K-12 education and citizen scientists. MY NASA DATA (short for Mentoring and inquirY using NASA Data on Atmospheric and earth science for Teachers and Amateurs) consists of a web space that collects tools, lesson plans, and specially developed documentation to help the target audience more easily use the vast collection of NASA data about the Earth System. The core piece of the MY NASA DATA project is the creation of microsets (both static and custom) that make data easily accessible. The installation of a Live Access Server (LAS) greatly enhanced the ability for teachers, students, and citizen scientists to create and explore custom microsets of Earth System Science data. The LAS, which is an open source software tool using emerging data standards, also allows the MY NASA DATA team to make available data on other aspects of the Earth System from collaborating data centers. We are currently working with the Physical Oceanography DAAC at the Jet Propulsion Laboratory to bring in several parameters describing the ocean. In addition, MY NASA DATA serves as a central space for the K-12 community to share resources. The site already includes a dozen User-contributed lesson plans. This year we will be focusing on the Citizen Science portion of the site, and will be welcoming user-contributed project ideas, as well as reports of completed projects. An e-mentor network has also been created to involve a wider community in
The Space Geodesy Project and Radio Frequency Interference Characterization and Mitigation
Lawrence, Hilliard M.; Beaudoin, C.; Corey, B. E.; Tourain, C. L.; Petrachenko, B.; Dickey, John
2013-01-01
The Space Geodesy Project (SGP) development by NASA is an effort to co-locate the four international geodetic techniques Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR), Very Long Baseline Interferometry (VLBI), Global Navigation Satellite System (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) into one tightly referenced campus and coordinated reference frame analysis. The SGP requirement locates these stations within a small area to maintain line-of-sight and frequent automated survey known as the vector tie system. This causes a direct conflict with the new broadband VLBI technique. Broadband means 2-14 GHz, and RFI susceptibility at -80 dBW or higher due to sensitive RF components in the front end of the radio receiver.
Directory of Open Access Journals (Sweden)
Magalas L.B.
2015-06-01
Full Text Available In this work, we present a novel Hilbert-twin method to compute an envelope and the logarithmic decrement, δ, from exponentially damped time-invariant harmonic strain signals embedded in noise. The results obtained from five computing methods: (1 the parametric OMI (Optimization in Multiple Intervals method, two interpolated discrete Fourier transform-based (IpDFT methods: (2 the Yoshida-Magalas (YM method and (3 the classic Yoshida (Y method, (4 the novel Hilbert-twin (H-twin method based on the Hilbert transform, and (5 the conventional Hilbert transform (HT method are analyzed and compared. The fundamental feature of the Hilbert-twin method is the efficient elimination of intrinsic asymmetrical oscillations of the envelope, aHT (t, obtained from the discrete Hilbert transform of analyzed signals. Excellent performance in estimation of the logarithmic decrement from the Hilbert-twin method is comparable to that of the OMI and YM for the low- and high-damping levels. The Hilbert-twin method proved to be robust and effective in computing the logarithmic decrement and the resonant frequency of exponentially damped free decaying signals embedded in experimental noise. The Hilbert-twin method is also appropriate to detect nonlinearities in mechanical loss measurements of metals and alloys.
Use of projectional phase space data to infer a 4D particle distribution
International Nuclear Information System (INIS)
Friedman, A.; Grote, D.P.; Celata, C.M.; Staples, J.W.
2002-01-01
We consider beams which are described by a 4D transverse distribution f(x, y, x(prime), y(prime)), where x(prime) (triple b ond) p x /p z and z is the axial coordinate. A two-slit scanner is commonly employed to measure, over a sequence of shots, a 2D projection of such a beam's phase space, e.g., f(x, x(prime)). Another scanner might yield f(y, y(prime)) or, using crossed slits, f(x, y). A small set of such 2D scans does not uniquely specify f(x, y, x(prime), y(prime)). We have developed ''tomographic'' techniques to synthesize a ''reasonable'' set of particles in a 4D phase space having 2D densities consistent with the experimental data. These techniques are described in a separate document [A. Friedman, et. al., submitted to Phys. Rev. ST-AB, 2002]. Here we briefly summarize one method and describe progress in validating it, using simulations of the High Current Experiment at Lawrence Berkeley National Laboratory
The Riemann surface of static limit dispersion relation and projective spaces
International Nuclear Information System (INIS)
Majewski, M.; Meshcheryakov, V.A.; Meshcheryakov, D.V.; Tran Quang Tuyet
2004-01-01
The rigorous Bogolyubov's proof of the dispersion relations (DR) for pion-nucleon scattering is a good foundation for the static models. DR contain a small parameter (ratio of the pion-nucleon masses). The static models arise when this parameter goes to zero. The S-matrix in the static models has a block structure. Each block of the S-matrix has a finite order NxN and is a matrix of meromorphic functions of the light particle energy ω in the complex plane with cuts (-∞, -1], [+1,+∞). In the elastic case, it reduces to N functions S i (ω) connected by the NxN crossing-symmetry matrix A. The unitarity and the crossing symmetry are the base for the system of nonlinear boundary value problems. It defines the analytical continuation of S i (ω) from the physical sheet to the unphysical ones and can be treated as a system of nonlinear difference equations. The problem is solvable for any 2x2 crossing-symmetry matrix A that permits one to calculate the Regge trajectories for the SU(2) static model. It is shown that global analyses of this system can be carried out effectively in projective spaces P N-1 and P N . The connection between the spaces P N-1 and P N is discussed. Some particular solutions of the system are found
Hydrogen Research for Spaceport and Space-Based Applications: Fuel Cell Projects
Anderson, Tim; Balaban, Canan
2008-01-01
The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Fuel cell research focused on proton exchange membranes (PEM), solid oxide fuel cells (SOFC). Specific technologies included aircraft fuel cell reformers, new and improved electrodes, electrolytes, interconnect, and seals, modeling of fuel cells including CFD coupled with impedance spectroscopy. Research was conducted on new materials and designs for fuel cells, along with using embedded sensors with power management electronics to improve the power density delivered by fuel cells. Fuel cell applications considered were in-space operations, aviation, and ground-based fuel cells such as; powering auxiliary power units (APUs) in aircraft; high power density, long duration power supplies for interplanetary missions (space science probes and planetary rovers); regenerative capabilities for high altitude aircraft; and power supplies for reusable launch vehicles.
Directory of Open Access Journals (Sweden)
Raechel Tiffe
2017-08-01
Full Text Available Abstract This essay examines the rhetorical and structural divides between the “inside” and “outside” carceral world as they exist within the intersections of racialized state violence and biopolitics. It is also a reflection on my embodied experience, as a volunteer and activist, inside penal and correctional facilities, not in an attempt to center my “freeworld” body as more important than the embodied experiences of incarcerated people, but rather to trouble that binary altogether and to use my experience as a perceived outsider to illuminate what I call the compounds of projected deviance. I will use my experiences working in jails as well as my experiences teaching yoga in an addiction correctional facility to argue for prison abolition and transformative justice, particularly in relation to resettlement. Drawing on the work of prison and queer studies, I argue that space, race, and sexuality interlock in significant ways in historical and contemporary prisons and jails. I will also use my reflections to argue that the feminist project of sexual liberation and autonomy must start with a rejection of sexual Othering for the most marginalized members of society: incarcerated people.
International Nuclear Information System (INIS)
Patricia Jaramillo A Liliana Vinasco T
2005-01-01
This paper presents a methodological proposal that is developed to identify corridors for lineal projects (highways, transmission lines, pipelines, etc), with environmental management criteria, when there is not complete information about the area of influence of the project, or some of the information is imprecise. Also a computational module is developed that allow the use of the methodological proposal. The proposal is based in the fuzzy multiobjective analysis concept, which takes elements of the diffuse logic and the traditional Multiobjective Analysis; the first one, it conserves its properties with imprecise information and of the second allows, the minimization of multiple objective correspond to the least environmental the physical, biological, cultural, economical and political dimensions of the environment uses the Geographic Information SIG this proposal is being constituted a complete tool for taking decisions in which space attributed is included. The FMA is a recent technique that is in development [S integration to GIS is stiller. The proposal is a contribution to the construction of a conceptual scheme for future applications in this aspects constitute a tool for the environmental planning which decreasing the risks, future cost analysis of natural resources and human group
Osann Jochum, M. A.; Demeter Partners
2006-08-01
The project DEMETER (DEMonstration of Earth observation TEchnologies in Routine irrigation advisory services) was dedicated to assessing and demonstrating improvements introduced by Earth observation (EO) and Information and Communication Technologies (ICT) in farm and Irrigation Advisory Service (IAS) day-to-day operations. The DEMETER concept of near-real-time delivery of EO-based irrigation scheduling information to IAS and farmers has proven to be valid. The operationality of the space segment was demonstrated for Landsat 5-TM in the Barrax pilot zone during the 2004 and 2005 irrigation campaigns. Extra-fast image delivery and quality controlled operational processing make the EO-based crop coefficient maps available at the same speed and quality as ground-based data (point samples), while significantly extending the spatial coverage and reducing service cost. Leading-edge online analysis and visualization tools provide easy, intuitive access to the information and personalized service to users. First feedback of users at IAS and farmer level is encouraging. The paper gives an overview of the project and its main achievements.
LaBelle, Remi C.; Rochblatt, David J.
2018-06-01
The NASA Deep Space Network (DSN) has recently constructed two new 34-m antennas at the Canberra Deep Space Communications Complex (CDSCC). These new antennas are part of the larger DAEP project to add six new 34-m antennas to the DSN, including two in Madrid, three in Canberra and one in Goldstone (California). The DAEP project included development and implementation of several new technologies for the X, and Ka (32 GHz) -band uplink and downlink electronics. The electronics upgrades were driven by several different considerations, including parts obsolescence, cost reduction, improved reliability and maintainability, and capability to meet future performance requirements. The new antennas are required to support TT&C links for all of the NASA deep-space spacecraft, as well as for several international partners. Some of these missions, such as Voyager 1 and 2, have very limited link budgets, which results in demanding requirements for system G/T performance. These antennas are also required to support radio science missions with several spacecraft, which dictate some demanding requirements for spectral purity, amplitude stability and phase stability for both the uplink and downlink electronics. After completion of these upgrades, a comprehensive campaign of tests and measurements took place to characterize the electronics and calibrate the antennas. Radiometric measurement techniques were applied to characterize, calibrate, and optimize the performance of the antenna parameters. These included optical and RF high-resolution holographic and total power radiometry techniques. The methodology and techniques utilized for the measurement and calibration of the antennas is described in this paper. Lessons learned (not all discussed in this paper) from the commissioning of the first antenna (DSS-35) were applied to the commissioning of the second antenna (DSS-36). These resulted in achieving antenna aperture efficiency of 66% (for DSS-36), at Ka-Band (32-Ghz), which is
Pustil'Nik, Lev
We present more then 10 year experience of educational project in Space/Astrophysics/Environment field, realized on the base of National Science- Educational Center "Blossoms of Science" of the Jordan Valley College. Our approach is based on the natural curiosity of children as driver of their self-development from the first minutes of their life and even in adult state. This approach shift center of the weight in educational process from direct lectures, sermons, explanation from teacher to children on own attempts of children to investigate problem, what is interesting for them, by themselves (individually or in group). Our approach includes four levels of the projects: "nano-projects" for children garden and basic school (up to 10-12 years), "micro-projects" for intermediate school (12-16 years), "mini-projects" for high school (16-18 years), and "macro-projects" for the best graduates high schools and students of colleges (17-22 years). These levels and projects are interconnected one with another and sometimes participants, started on the micro-projects level in intermediate school, continue their activity up to macro-projects of the graduate's diploma level. For each level we organize courses for preparation of the teachers and instructors, interested in the using of our receipts, and published books and brochures for them. The content of our activity for different levels: a) Level of kinder gardens/basic schools- special software with interactive movie -nano-projects; b) Level of intermediate school: "Days of Science" in tens schools of Israel- first contact with astronomy; c) Summer astronomy camps (4-5 of one week camps on 200-300 pupils from all country) with introduce to astronomy and with preparation of micro-projects on themes - first successful experience of research in real science fields (hundreds projects); d) ASTROTOP - one year program of preparation of short projects, with solution on the quality level of chosen astrophysical problem - mini-projects
Wavelet Based Hilbert Transform with Digital Design and Application to QCM-SS Watermarking
Directory of Open Access Journals (Sweden)
S. P. Maity
2008-04-01
Full Text Available In recent time, wavelet transforms are used extensively for efficient storage, transmission and representation of multimedia signals. Hilbert transform pairs of wavelets is the basic unit of many wavelet theories such as complex filter banks, complex wavelet and phaselet etc. Moreover, Hilbert transform finds various applications in communications and signal processing such as generation of single sideband (SSB modulation, quadrature carrier multiplexing (QCM and bandpass representation of a signal. Thus wavelet based discrete Hilbert transform design draws much attention of researchers for couple of years. This paper proposes an (i algorithm for generation of low computation cost Hilbert transform pairs of symmetric filter coefficients using biorthogonal wavelets, (ii approximation to its rational coefficients form for its efficient hardware realization and without much loss in signal representation, and finally (iii development of QCM-SS (spread spectrum image watermarking scheme for doubling the payload capacity. Simulation results show novelty of the proposed Hilbert transform design and its application to watermarking compared to existing algorithms.
Xu, Haotong; Li, Xiaoxiao; Zhang, Zhengzhi; Qiu, Mingguo; Mu, Qiwen; Wu, Yi; Tan, Liwen; Zhang, Shaoxiang; Zhang, Xiaoming
2011-01-01
Background The major hindrance to multidetector CT imaging of the left extraperitoneal space (LES), and the detailed spatial relationships to its related spaces, is that there is no obvious density difference between them. Traditional gross anatomy and thick-slice sectional anatomy imagery are also insufficient to show the anatomic features of this narrow space in three-dimensions (3D). To overcome these obstacles, we used a new method to visualize the anatomic features of the LES and its spatial associations with related spaces, in random sections and in 3D. Methods In conjunction with Mimics® and Amira® software, we used thin-slice cross-sectional images of the upper abdomen, retrieved from the Chinese and American Visible Human dataset and the Chinese Virtual Human dataset, to display anatomic features of the LES and spatial relationships of the LES to its related spaces, especially the gastric bare area. The anatomic location of the LES was presented on 3D sections reconstructed from CVH2 images and CT images. Principal Findings What calls for special attention of our results is the LES consists of the left sub-diaphragmatic fat space and gastric bare area. The appearance of the fat pad at the cardiac notch contributes to converting the shape of the anteroexternal surface of the LES from triangular to trapezoidal. Moreover, the LES is adjacent to the lesser omentum and the hepatic bare area in the anterointernal and right rear direction, respectively. Conclusion The LES and its related spaces were imaged in 3D using visualization technique for the first time. This technique is a promising new method for exploring detailed communication relationships among other abdominal spaces, and will promote research on the dynamic extension of abdominal diseases, such as acute pancreatitis and intra-abdominal carcinomatosis. PMID:22087259
Czech Academy of Sciences Publication Activity Database
Engliš, Miroslav; Hänninen, T.; Taskinen, J.
2006-01-01
Roč. 32, č. 2 (2006), s. 253-275 ISSN 0362-1588 R&D Projects: GA ČR(CZ) GA201/03/0041; GA AV ČR(CZ) IAA1019304 Institutional research plan: CEZ:AV0Z10190503 Keywords : Bergman projection * weighted supremum norms * locally convex space Subject RIV: BA - General Mathematics Impact factor: 0.354, year: 2006
International Nuclear Information System (INIS)
Furdea, A; Wilson, J D; Eswaran, H; Lowery, C L; Govindan, R B; Preissl, H
2009-01-01
We propose a multi-stage approach using Wavelet and Hilbert transforms to identify uterine contraction bursts in magnetomyogram (MMG) signals measured using a 151 magnetic sensor array. In the first stage, we decompose the MMG signals by wavelet analysis into multilevel approximate and detail coefficients. In each level, the signals are reconstructed using the detail coefficients followed by the computation of the Hilbert transform. The Hilbert amplitude of the reconstructed signals from different frequency bands (0.1–1 Hz) is summed up over all the sensors to increase the signal-to-noise ratio. Using a novel clustering technique, affinity propagation, the contractile bursts are distinguished from the noise level. The method is applied on simulated MMG data, using a simple stochastic model to determine its robustness and to seven MMG datasets
Sima, Chaotan; Gates, J C; Holmes, C; Mennea, P L; Zervas, M N; Smith, P G R
2013-09-01
Terahertz bandwidth photonic Hilbert transformers are proposed and experimentally demonstrated. The integrated device is fabricated via a direct UV grating writing technique in a silica-on-silicon platform. The photonic Hilbert transformer operates at bandwidths of up to 2 THz (~16 nm) in the telecom band, a 10-fold greater bandwidth than any previously reported experimental approaches. Achieving this performance requires detailed knowledge of the system transfer function of the direct UV grating writing technique; this allows improved linearity and yields terahertz bandwidth Bragg gratings with improved spectral quality. By incorporating a flat-top reflector and Hilbert grating with a waveguide coupler, an ultrawideband all-optical single-sideband filter is demonstrated.
Chrysoulakis, Nektarios; Marconcini, Mattia; Gastellu-Etchegorry, Jean-Philippe; Grimmond, Sue; Feigenwinter, Christian; Lindberg, Fredrik; Del Frate, Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Landier, Lucas; Gabey, Andy; Parlow, Eberhard; Olofson, Frans
2017-04-01
The H2020-Space project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of Copernicus Sentinels to retrieve anthropogenic heat flux, as a key component of the Urban Energy Budget (UEB). URBANFLUXES advances the current knowledge of the impacts of UEB fluxes on urban heat island and consequently on energy consumption in cities. In URBANFLUXES, the anthropogenic heat flux is estimated as a residual of UEB. Therefore, the rest UEB components, namely, the net all-wave radiation, the net change in heat storage and the turbulent sensible and latent heat fluxes are independently estimated from Earth Observation (EO), whereas the advection term is included in the error of the anthropogenic heat flux estimation from the UEB closure. The Discrete Anisotropic Radiative Transfer (DART) model is employed to improve the estimation of the net all-wave radiation balance, whereas the Element Surface Temperature Method (ESTM), adjusted to satellite observations is used to improve the estimation the estimation of the net change in heat storage. Furthermore the estimation of the turbulent sensible and latent heat fluxes is based on the Aerodynamic Resistance Method (ARM). Based on these outcomes, QF is estimated by regressing the sum of the turbulent heat fluxes versus the available energy. In-situ flux measurements are used to evaluate URBANFLUXES outcomes, whereas uncertainties are specified and analyzed. URBANFLUXES is expected to prepare the ground for further innovative exploitation of EO in scientific activities (climate variability studies at local and regional scales) and future and emerging applications (sustainable urban planning, mitigation technologies) to benefit climate change mitigation/adaptation. This study presents the results of the second phase of the project and detailed information on URBANFLUXES is available at: http://urbanfluxes.eu
Burning Plastics Investigated in Space for Unique US/Russian Cooperative Project
Friedman, Robert
2000-01-01
It is well known that fires in the low-gravity environment of Earth-orbiting spacecraft are different from fires on Earth. The flames lack the familiar upward plume, which is the result of gravitational buoyancy. These flames, however, are strongly influenced by minor airflow currents. A recent study conducted in low gravity (microgravity) on the Russian orbital station Mir used burning plastic rods mounted in a small chamber with a controllable fan to expose the flame to airflows of different velocities. In this unique project, a Russian scientific agency, the Keldysh Research Center, furnished the apparatus and directed the Mir tests, while the NASA Glenn Research Center at Lewis Field provided the test materials and the project management. Reference testing and calibrations in ground laboratories were conducted jointly by researchers at Keldysh and at the NASA Johnson Space Center's White Sands Test Facility. Multiple samples of three different plastics were burned in the tests: Delrin, a common material for valve bodies; PMMA, a plastic "glass"; and polyethylene, a familiar material for containers and films. Each burned with a unique spherical or egg-shaped flame that spread over the rod. The effect of varying the airflow was dramatic. At the highest airflow attainable in the combustion chamber, nearly 10 cm/sec (a typical ventilation breeze), the flames were bright and strong. As airflow velocity decreased, the flames became shorter but wider. In addition, the flames became less bright, and for PMMA and polyethylene, they showed two colors, a bright part decreasing in volume and a nearly invisible remainder (see the photographs). Finally, at a very low velocity, the flames extinguished. For the plastics tested, this minimum velocity was very low, around 0.3 to 0.5 cm/sec. This finding confirms that at least a slight airflow is required to maintain a flame in microgravity for these types of materials.
Directory of Open Access Journals (Sweden)
Lucinei Pereira da Silva
2012-12-01
Full Text Available The representations and memory of living space are essential to developing mental maps and cartographic documents. In this regard this investigation as a primary objective to understand how mind maps can contribute pedagogically classes in Geography and History as well, breaking the dichotomy space / time. From the point of view of theoretical and methodological the research relied on the analysis of the school project “Our Neighborhood, Our Place” developed at the Municipal School “Vereador Hamilton Teodoro” in Governador Valadares (MG, along with a group of 7th grades from elementary school and the articulation of authors who discuss the concepts of representation, memory, space and place.
Casazza, Peter G
1989-01-01
This monograph provides a structure theory for the increasingly important Banach space discovered by B.S. Tsirelson. The basic construction should be accessible to graduate students of functional analysis with a knowledge of the theory of Schauder bases, while topics of a more advanced nature are presented for the specialist. Bounded linear operators are studied through the use of finite-dimensional decompositions, and complemented subspaces are studied at length. A myriad of variant constructions are presented and explored, while open questions are broached in almost every chapter. Two appendices are attached: one dealing with a computer program which computes norms of finitely-supported vectors, while the other surveys recent work on weak Hilbert spaces (where a Tsirelson-type space provides an example).
International Nuclear Information System (INIS)
Flemming, Jens; Hofmann, Bernd
2011-01-01
In this paper, we enlighten the role of variational inequalities for obtaining convergence rates in Tikhonov regularization of nonlinear ill-posed problems with convex penalty functionals under convexity constraints in Banach spaces. Variational inequalities are able to cover solution smoothness and the structure of nonlinearity in a uniform manner, not only for unconstrained but, as we indicate, also for constrained Tikhonov regularization. In this context, we extend the concept of projected source conditions already known in Hilbert spaces to Banach spaces, and we show in the main theorem that such projected source conditions are to some extent equivalent to certain variational inequalities. The derived variational inequalities immediately yield convergence rates measured by Bregman distances
Sauerwein, Timothy A.; Gostomski, Tom
2007-01-01
The Space Technology 5(ST5) payload was successfully carried into orbit on an OSC Pegasus XL launch vehicle, which was carried aloft and dropped from the OSC Lockheed L-1011 from Vandenberg Air Force Base March 22,2006, at 9:03 am Eastern time, 6:03 am Pacific time. In order to reach the completion of the development and successful launch of ST 5, the systems integration and test(I&T) team determined that a different approach was required to meet the project requirements rather than the standard I&T approach used for single, room-sized satellites. The ST5 payload, part of NASA's New Millennium Program headquartered at JPL, consisted of three micro satellites (approximately 30 kg each) and the Pegasus Support Structure (PSS), the system that connected the spacecrafts to the launch vehicle and deployed the spacecrafts into orbit from the Pegasus XL launch vehicle. ST5 was a technology demonstration payload, intended to test six (6) new technologies for potential use for future space flights along with demonstrating the ability of small satellites to perform quality science. The main technology was a science grade magnetometer designed to take measurements of the earth's magnetic field. The three spacecraft were designed, integrated, and tested at NASA Goddard Space Flight Center with integration and environmental testing occurring in the Bldg. 7-1 0-15-29. The three spacecraft were integrated and tested by the same I&T team. The I&T Manager determined that there was insufficient time in the schedule to perform the three I&T spacecraft activities in series used standard approaches. The solution was for spacecraft #1 to undergo integration and test first, followed by spacecraft #2 and #3 simultaneously. This simultaneous integration was successful for several reasons. Each spacecraft had a Lead Test Conductor who planned and coordinated their spacecraft through its integration and test activities. One team of engineers and technicians executed the integration of all
Cutting force response in milling of Inconel: analysis by wavelet and Hilbert-Huang Transforms
Directory of Open Access Journals (Sweden)
Grzegorz Litak
Full Text Available We study the milling process of Inconel. By continuously increasing the cutting depth we follow the system response and appearance of oscillations of larger amplitude. The cutting force amplitude and frequency analysis has been done by means of wavelets and Hilbert-Huang transform. We report that in our system the force oscillations are closely related to the rotational motion of the tool and advocate for a regenerative mechanism of chatter vibrations. To identify vibrations amplitudes occurrence in time scale we apply wavelet and Hilbert-Huang transforms.
Methods for detection and characterization of signals in noisy data with the Hilbert-Huang transform
International Nuclear Information System (INIS)
Stroeer, Alexander; Cannizzo, John K.; Camp, Jordan B.; Gagarin, Nicolas
2009-01-01
The Hilbert-Huang transform is a novel, adaptive approach to time series analysis that does not make assumptions about the data form. Its adaptive, local character allows the decomposition of nonstationary signals with high time-frequency resolution but also renders it susceptible to degradation from noise. We show that complementing the Hilbert-Huang transform with techniques such as zero-phase filtering, kernel density estimation and Fourier analysis allows it to be used effectively to detect and characterize signals with low signal-to-noise ratios.
On the discovery of the gravitational field equations by Einstein and Hilbert: new materials
International Nuclear Information System (INIS)
Vizgin, Vladimir P
2001-01-01
This article describes the history of discovery of the equations of gravitational field by Albert Einstein and David Hilbert in November 1915. The proof sheet of Hilbert's lecture report, made on 20 November 1915 and published in March 1916, rediscovered in 1997 in the archive of the university of Goettingen, throws new light on the history of this discovery. We also discuss the early history of the general theory of relativity that led to the expression of the general covariant equations of gravitational field. (from the history of physics)
An FP7 "Space" project: Aphorism "Advanced PRocedures for volcanic and Seismic Monitoring"
Di Iorio, A., Sr.; Stramondo, S.; Bignami, C.; Corradini, S.; Merucci, L.
2014-12-01
APHORISM project proposes the development and testing of two new methods to combine Earth Observation satellite data from different sensors, and ground data. The aim is to demonstrate that this two types of data, appropriately managed and integrated, can provide new improved GMES products useful for seismic and volcanic crisis management. The first method, APE - A Priori information for Earthquake damage mapping, concerns the generation of maps to address the detection and estimate of damage caused by a seism. The use of satellite data to investigate earthquake damages is not an innovative issue. We can find a wide literature and projects concerning such issue, but usually the approach is only based on change detection techniques and classifications algorithms. The novelty of APE relies on the exploitation of a priori information derived by InSAR time series to measure surface movements, shake maps obtained from seismological data, and vulnerability information. This a priori information is then integrated with change detection map to improve accuracy and to limit false alarms. The second method deals with volcanic crisis management. The method, MACE - Multi-platform volcanic Ash Cloud Estimation, concerns the exploitation of GEO (Geosynchronous Earth Orbit) sensor platform, LEO (Low Earth Orbit) satellite sensors and ground measures to improve the ash detection and retrieval and to characterize the volcanic ash clouds. The basic idea of MACE consists of an improvement of volcanic ash retrievals at the space-time scale by using both the LEO and GEO estimations and in-situ data. Indeed the standard ash thermal infrared retrieval is integrated with data coming from a wider spectral range from visible to microwave. The ash detection is also extended in case of cloudy atmosphere or steam plumes. APE and MACE methods have been defined in order to provide products oriented toward the next ESA Sentinels satellite missions.The project is funded under the European Union FP7
TanDEM-X the Earth surface observation project from space level - basis and mission status
Directory of Open Access Journals (Sweden)
Jerzy Wiśniowski
2015-03-01
Full Text Available TanDEM-X is DLR (Deutsches Zentrum für Luft- und Raumfahrt the Earth surface observation project using high-resolution SAR interferometry. It opens a new era in space borne radar remote sensing. The system is based on two satellites: TerraSAR-X (TSX and TanDEM-X (TDX flying on the very close, strictly controlled orbits. This paper gives an overview of the radar technology and overview of the TanDEM-X mission concept which is based on several innovative technologies. The primary objective of the mission is to deliver a global digital elevation model (DEM with an unprecedented accuracy, which is equal to or surpass the HRTI-3 specifications (12 m posting, relative height accuracy ±2 m for slope < 20% and ±4 m for slope > 20% [8]. Beyond that, TanDEM-X provides a highly reconfigurable platform for the demonstration of new radar imaging techniques and applications.[b]Keywords[/b]: remote sensing, Bistatic SAR, digital elevation model (DEM, Helix formation, SAR interferomery, HRTI-3, synchronization
Vector bundles on complex projective spaces with an appendix by S. I. Gelfand
Okonek, Christian; Spindler, Heinz
1980-01-01
This expository treatment is based on a survey given by one of the authors at the Séminaire Bourbaki in November 1978 and on a subsequent course held at the University of Göttingen. It is intended to serve as an introduction to the topical question of classification of holomorphic vector bundles on complex projective spaces, and can easily be read by students with a basic knowledge of analytic or algebraic geometry. Short supplementary sections describe more advanced topics, further results, and unsolved problems. This is a corrected third printing with an Appendix by S. I. Gelfand. ------ The present book is the first one, within the extensive literature on algebraic vector bundles, to give both a self-contained introduction to the basic methods and an exposition of the current state of the classification theory of algebraic vector bundles over Pn(C). (…) The reviewer thinks that readers should be grateful to the authors for presenting the first detailed, self-contained and systematic textbook on ve...
Project first and eye on the sky: strategies for teaching space science in the early grades
Paglierani, R.; Hawkins, I.
Elementary educators typically have only limited opportunity to teach substantive science units. This is due, in great part, to the current primary focus on literacy and mathematics instruction in the early grades. It is not surprising then, that the time and resources allocated to science teaching are significantly less than those allocated to language arts and mathematics. The integration of elementary science curricula with language arts provides one means of addressing the challenge of maintaining a robust science presence in the elementary classroom. Project FIRST's Eye on the Sky suggests a model for the successful integration of science instruction with language arts through inquiry-based learning. The model has been adopted by other Education/Public Outreach efforts, most recently, the Cassini- Huygens Mission and the Space Telescope Institute. We will present Eye on the Sky: Our Star the Sun, a suite of integrated, inquiry-based lessons designed specifically for K-4 students and discuss data showing the program's impact on the user audience. These materials offer an exciting opportunity to explore the dynamic Sun and share research discoveries of NASA's Sun-Earth Connection with the elementary education community. The lessons were developed and tested by UC Berkeley educators and NASA scientists in partnership with classroom teachers. We will review the program components and examine the benefits and challenges inherent in implementing such a program in the elementary school setting.
Rosenberg, Leigh; Hihn, Jairus; Roust, Kevin; Warfield, Keith
2000-01-01
This paper presents an overview of a parametric cost model that has been built at JPL to estimate costs of future, deep space, robotic science missions. Due to the recent dramatic changes in JPL business practices brought about by an internal reengineering effort known as develop new products (DNP), high-level historic cost data is no longer considered analogous to future missions. Therefore, the historic data is of little value in forecasting costs for projects developed using the DNP process. This has lead to the development of an approach for obtaining expert opinion and also for combining actual data with expert opinion to provide a cost database for future missions. In addition, the DNP cost model has a maximum of objective cost drivers which reduces the likelihood of model input error. Version 2 is now under development which expands the model capabilities, links it more tightly with key design technical parameters, and is grounded in more rigorous statistical techniques. The challenges faced in building this model will be discussed, as well as it's background, development approach, status, validation, and future plans.
General-purpose heat source project and space nuclear safety and fuels program. Progress report
International Nuclear Information System (INIS)
Maraman, W.J.
1980-02-01
Studies related to the use of 238 PuO 2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of LASL are presented. The three programs involved are: general-purpose heat source development; space nuclear safety; and fuels program. Three impact tests were conducted to evaluate the effects of a high temperature reentry pulse and the use of CBCF on impact performance. Additionally, two 238 PuO 2 pellets were encapsulated in Ir-0.3% W for impact testing. Results of the clad development test and vent testing are noted. Results of the environmental tests are summarized. Progress on the Stirling isotope power systems test and the status of the improved MHW tests are indicated. The examination of the impact failure of the iridium shell of MHFT-65 at a fuel pass-through continued. A test plan was written for vibration testing of the assembled light-weight radioisotopic heater unit. Progress on fuel processing is reported
Foundations of phase-space quantum mechanics
International Nuclear Information System (INIS)
Guz, W.
1984-01-01
In the present paper a general concept of a phase-space representation of the ordinary Hilbert-space quantum theory is formulated, and then, by using some elementary facts of functional analysis, several equivalent forms of that concept are analyzed. Several important physical examples are presented in Section 3 of the paper. (author)
Zhuang, L.; Khan, M.R.H.; Beeker, Willem; Beeker, W.P.; Leinse, Arne; Heideman, Rene; Roeloffzen, C.G.H.
2012-01-01
We propose and demonstrate a novel wideband microwave photonic fractional Hilbert transformer implemented using a ring resonatorbased optical all-pass filter. The full programmability of the ring resonator allows variable and arbitrary fractional order of the Hilbert transformer. The performance
Batsleer, Janet; Andersson, Björn; Liljeholm Hansson, Susanne; Lütgens, Jessica; Mengilli, Yagmur; Pais, Alexandre; Pohl, Axel; Wissö, Therése
2018-01-01
Drawing on research in progress in the Partispace project we make a case for the recognition of the importance of non-formal spaces in response to young refugees across three different national contexts: Frankfurt in Germany; Gothenburg in Sweden; and Manchester in the UK. It is argued that recognition of local regulation and national controls of…
Rainer, Löwen
2017-01-01
We prove that the automorphism group of a topological parallelism on real projective 3-space is compact. In a preceding article it was proved that at least the connected component of the identity is compact. The present proof does not depend on that earlier result.
McGinty, Lorna
2013-01-01
This short case study gives insight into a theatre-making project with young lesbian, gay, bisexual and trans-identified people. The author reflects on the capacity of collaborative arts practice to open discussion around identity and allow space to re-imagine lived experience through metaphor and mythology. She focuses on the central role of the…
Struck, C.; Wilde, de P.J.C.J.; Hopfe, C.J.; Hensen, J.L.M.
2008-01-01
This paper describes research conducted to gather empirical evidence on extent, character and content of the option space in building design projects, from the perspective of a climate engineer using building performance simulation for concept evaluation. The goal is to support uncertainty analysis
Bone, M.; Cloutier, R.L.; Gill, E.K.A.; Verma, D.
2009-01-01
There is increased recognition of the role of systems engineering in reducing the risk (technical, cost, and schedule) on complex space systems development and integration projects. A number of international systems engineering standards have been published in the last five years (ISO 15288, IEEE
Ng, Chee Hoe; Adnan, M.
2018-01-01
This research aims to investigate the effect of integrating STEM education through Project-based Inquiry Learning (PIL) and the users of the STEM modules which consists of five projects on topic Space in Year One Mathematics Syllabus in Kurikulum Standard Sekolah Rendah (KSSR) of Malaysia. STEM education in primary school focuses on the introduces and awareness of students about the importance of STEM education. The projects in STEM modules are covering the different ethnic cultures in Malaysia. The modules are designed using the four phases in PIL. Concepts and the explanation of STEM education on each project are emphasized and provided in the modules so the teachers able to carry out the projects by using the modules. By using the modules in primary Mathematics, the students and teachers will be more understanding on how to integrate the Mathematics’ concepts in STEM education.
Convexity and the Euclidean Metric of Space-Time
Directory of Open Access Journals (Sweden)
Nikolaos Kalogeropoulos
2017-02-01
Full Text Available We address the reasons why the “Wick-rotated”, positive-definite, space-time metric obeys the Pythagorean theorem. An answer is proposed based on the convexity and smoothness properties of the functional spaces purporting to provide the kinematic framework of approaches to quantum gravity. We employ moduli of convexity and smoothness which are eventually extremized by Hilbert spaces. We point out the potential physical significance that functional analytical dualities play in this framework. Following the spirit of the variational principles employed in classical and quantum Physics, such Hilbert spaces dominate in a generalized functional integral approach. The metric of space-time is induced by the inner product of such Hilbert spaces.
Self-calibration for lab-μCT using space-time regularized projection-based DVC and model reduction
Jailin, C.; Buljac, A.; Bouterf, A.; Poncelet, M.; Hild, F.; Roux, S.
2018-02-01
An online calibration procedure for x-ray lab-CT is developed using projection-based digital volume correlation. An initial reconstruction of the sample is positioned in the 3D space for every angle so that its projection matches the initial one. This procedure allows a space-time displacement field to be estimated for the scanned sample, which is regularized with (i) rigid body motions in space and (ii) modal time shape functions computed using model reduction techniques (i.e. proper generalized decomposition). The result is an accurate identification of the position of the sample adapted for each angle, which may deviate from the desired perfect rotation required for standard reconstructions. An application of this procedure to a 4D in situ mechanical test is shown. The proposed correction leads to a much improved tomographic reconstruction quality.
Richardson, J; Goss, Z; Pratt, A; Sharman, J; Tighe, M
2013-12-01
The health and well-being benefits of access to green space are well documented. Research suggests positive findings regardless of social group, however barriers exist that limit access to green space, including proximity, geography and differing social conditions. Current public health policy aims to broaden the range of environmental public health interventions through effective partnership working, providing opportunities to work across agencies to promote the use of green space. Health Impact Assessment (HIA) is a combination of methods and procedures to assess the potential health and well-being impacts of policies, developments and projects. It provides a means by which negative impacts can be mitigated and positive impacts can be enhanced, and has potential application for assessing green space use. This paper describes the application of a HIA approach to a multi-agency project (Stepping Stones to Nature--SS2N) in the UK designed to improve local green spaces and facilitate green space use in areas classified as having high levels of deprivation. The findings suggest that the SS2N project had the potential to provide significant positive benefits in the areas of physical activity, mental and social well-being. Specific findings for one locality identified a range of actions that could be taken to enhance benefits, and mitigate negative factors such as anti-social behaviour. The HIA approach proved to be a valuable process through which impacts of a community development/public health project could be enhanced and negative impacts prevented at an early stage; it illustrates how a HIA approach could enhance multi-agency working to promote health and well-being in communities.
The HYTHIRM Project: Flight Thermography of the Space Shuttle During the Hypersonic Re-entry
Horvath, Thomas J.; Tomek, Deborah M.; Berger, Karen T.; Zalameda, Joseph N.; Splinter, Scott C.; Krasa, Paul W.; Schwartz, Richard J.; Gibson, David M.; Tietjen, Alan B.; Tack, Steve
2010-01-01
This report describes a NASA Langley led endeavor sponsored by the NASA Engineering Safety Center, the Space Shuttle Program Office and the NASA Aeronautics Research Mission Directorate to demonstrate a quantitative thermal imaging capability. A background and an overview of several multidisciplinary efforts that culminated in the acquisition of high resolution calibrated infrared imagery of the Space Shuttle during hypervelocity atmospheric entry is presented. The successful collection of thermal data has demonstrated the feasibility of obtaining remote high-resolution infrared imagery during hypersonic flight for the accurate measurement of surface temperature. To maximize science and engineering return, the acquisition of quantitative thermal imagery and capability demonstration was targeted towards three recent Shuttle flights - two of which involved flight experiments flown on Discovery. In coordination with these two Shuttle flight experiments, a US Navy NP-3D aircraft was flown between 26-41 nautical miles below Discovery and remotely monitored surface temperature of the Orbiter at Mach 8.4 (STS-119) and Mach 14.7 (STS-128) using a long-range infrared optical package referred to as Cast Glance. This same Navy aircraft successfully monitored the Orbiter Atlantis traveling at approximately Mach 14.3 during its return from the successful Hubble repair mission (STS-125). The purpose of this paper is to describe the systematic approach used by the Hypersonic Thermodynamic Infrared Measurements team to develop and implement a set of mission planning tools designed to establish confidence in the ability of an imaging platform to reliably acquire, track and return global quantitative surface temperatures of the Shuttle during entry. The mission planning tools included a pre-flight capability to predict the infrared signature of the Shuttle. Such tools permitted optimization of the hardware configuration to increase signal-to-noise and to maximize the available
Hilbert scheme of points on cyclic quotient singularities of type (p,1)
Gyenge, Ádám
2016-01-01
In this note we investigate the generating series of the Euler characteristics of Hilbert scheme of points on cyclic quotient singularities of type (p,1). We link the appearing combinatorics to p-fountains, a generalization of the notion of fountain of coins. We obtain a representation of the generating series as coefficient of a two variable generating series.
Experimental validation of a structural damage detection method based on marginal Hilbert spectrum
Banerji, Srishti; Roy, Timir B.; Sabamehr, Ardalan; Bagchi, Ashutosh
2017-04-01
Structural Health Monitoring (SHM) using dynamic characteristics of structures is crucial for early damage detection. Damage detection can be performed by capturing and assessing structural responses. Instrumented structures are monitored by analyzing the responses recorded by deployed sensors in the form of signals. Signal processing is an important tool for the processing of the collected data to diagnose anomalies in structural behavior. The vibration signature of the structure varies with damage. In order to attain effective damage detection, preservation of non-linear and non-stationary features of real structural responses is important. Decomposition of the signals into Intrinsic Mode Functions (IMF) by Empirical Mode Decomposition (EMD) and application of Hilbert-Huang Transform (HHT) addresses the time-varying instantaneous properties of the structural response. The energy distribution among different vibration modes of the intact and damaged structure depicted by Marginal Hilbert Spectrum (MHS) detects location and severity of the damage. The present work investigates damage detection analytically and experimentally by employing MHS. The testing of this methodology for different damage scenarios of a frame structure resulted in its accurate damage identification. The sensitivity of Hilbert Spectral Analysis (HSA) is assessed with varying frequencies and damage locations by means of calculating Damage Indices (DI) from the Hilbert spectrum curves of the undamaged and damaged structures.
Analysis of the Cofrentes instability with the Hilbert-Huang transform
International Nuclear Information System (INIS)
Blazquez, J.; Galindo, A.
2010-01-01
The most obvious application of the Hilbert-Huang transform is the denoising (signal isolation). In this article, the dynamic system is the power of a BWR reactor that undergoes instability. The signal and the dynamic systems are described, which in this case corresponds to a current incident in a commercial BWR reactor (Cofrentes). Finally, empirical modes are calculated and the results are analyzed.
Pairs of dual Gabor frames generated by functions of Hilbert-Schmidt type
DEFF Research Database (Denmark)
Christiansen, Lasse Hjuler
2015-01-01
where each member may be written as a linear combination of integer translates of any B-spline. We introduce functions of Hilbert-Schmidt type along with a new method which allows us to associate to certain such functions finite families of recursively defined dual windows of arbitrary smoothness...
Heterotic reduction of Courant algebroid connections and Einstein–Hilbert actions
Energy Technology Data Exchange (ETDEWEB)
Jurčo, Branislav, E-mail: jurco@karlin.mff.cuni.cz [Mathematical Institute, Faculty of Mathematics and Physics, Charles University, Prague 186 75 (Czech Republic); Vysoký, Jan, E-mail: vysoky@math.cas.cz [Institute of Mathematics of the Czech Academy of Sciences, Žitná 25, Prague 115 67 (Czech Republic); Mathematical Sciences Institute, Australian National University, Acton ACT 2601 (Australia)
2016-08-15
We discuss Levi-Civita connections on Courant algebroids. We define an appropriate generalization of the curvature tensor and compute the corresponding scalar curvatures in the exact and heterotic case, leading to generalized (bosonic) Einstein–Hilbert type of actions known from supergravity. In particular, we carefully analyze the process of the reduction for the generalized metric, connection, curvature tensor and the scalar curvature.
Heterotic reduction of Courant algebroid connections and Einstein–Hilbert actions
International Nuclear Information System (INIS)
Jurčo, Branislav; Vysoký, Jan
2016-01-01
We discuss Levi-Civita connections on Courant algebroids. We define an appropriate generalization of the curvature tensor and compute the corresponding scalar curvatures in the exact and heterotic case, leading to generalized (bosonic) Einstein–Hilbert type of actions known from supergravity. In particular, we carefully analyze the process of the reduction for the generalized metric, connection, curvature tensor and the scalar curvature.
Infinite conformal symmetries and Riemann-Hilbert transformation in super principal chiral model
International Nuclear Information System (INIS)
Hao Sanru; Li Wei
1989-01-01
This paper shows a new symmetric transformation - C transformation in super principal chiral model and discover an infinite dimensional Lie algebra related to the Virasoro algebra without central extension. By using the Riemann-Hilbert transformation, the physical origination of C transformation is discussed
A more accurate half-discrete Hardy-Hilbert-type inequality with the logarithmic function.
Wang, Aizhen; Yang, Bicheng
2017-01-01
By means of the weight functions, the technique of real analysis and Hermite-Hadamard's inequality, a more accurate half-discrete Hardy-Hilbert-type inequality related to the kernel of logarithmic function and a best possible constant factor is given. Moreover, the equivalent forms, the operator expressions, the reverses and some particular cases are also considered.
A more accurate half-discrete Hardy-Hilbert-type inequality with the logarithmic function
Directory of Open Access Journals (Sweden)
Aizhen Wang
2017-06-01
Full Text Available Abstract By means of the weight functions, the technique of real analysis and Hermite-Hadamard’s inequality, a more accurate half-discrete Hardy-Hilbert-type inequality related to the kernel of logarithmic function and a best possible constant factor is given. Moreover, the equivalent forms, the operator expressions, the reverses and some particular cases are also considered.
International Nuclear Information System (INIS)
Chau Ling-Lie; Ge Mo-Lin; Teh, Rosy.
1984-09-01
The Baecklund Transformations and the hidden symmetry algebra for Self-Dual Yang-Mills Equations, Landau-Lifshitz equations and the Extended Super Yang-Mills fields (N>2) are discussed on the base of the Regular Riemann-Hilbert Transform and the linearization equations. (author)
Weighted regularized statistical shape space projection for breast 3D model reconstruction.
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.
Alabi, O.; Agbaje, G.; Akinyede, J.
2015-12-01
The United Nations "Zero Gravity Instrument Project" (ZGIP) is one of the activities coordinated under the Space Education Outreach Program (SEOP) of the African Regional Centre for Space Science and Technology Education in English (ARCSSTE-E) to popularize space science among pre-collegiate youths in Nigeria. The vision of ZGIP is to promote space education and research in microgravity. This paper will deliberate on the strategy used to implement the ZGIP to introduce school children to authentic scientific data and inquiry. The paper highlights how the students learned to collect scientific data in a laboratory environment, analyzed the data with specialized software, obtained results, interpreted and presented the results of their study in a standard format to the scientific community. About 100 school children, aged between 7 and 21 years, from ten public and private schools located in Osun State, Nigeria participated in the pilot phase of the ZGIP which commenced with a 1-day workshop in March 2014. During the inauguration workshop, the participants were introduced to the environment of outer space, with special emphasis on the concept of microgravity. They were also taught the basic principle of operation of the Clinostat, a Zero-Gravity Instrument donated to ARCSSTE-E by the United Nations Office for Outer Space Affairs (UN-OOSA), Vienna, under the Human Space Technology Initiative (UN-HSTI). At the end of the workshop, each school designed a project, and had a period of 1 week, on a planned time-table, to work in the laboratory of ARCSSTE-E where they utilized the clinostat to examine the germination of indigenous plant seeds in simulated microgravity conditions. The paper also documents the post-laboratory investigation activities, which included presentation of the results in a poster competition and an evaluation of the project. The enthusiasm displayed by the students, coupled with the favorable responses recorded during an oral interview conducted to
Delay/Disruption Tolerant Networks for Human Space Flight Video Project
Fink, Patrick W.; Ngo, Phong; Schlesinger, Adam
2010-01-01
The movie describes collaboration between NASA and Vint Cerf on the development of Disruption Tolerant Networks (DTN) for use in space exploration. Current evaluation efforts at Johnson Space Center are focused on the use of DTNs in space communications. Tests include the ability of rovers to store data for later display, tracking local and remote habitat inventory using radio-frequency identification tags, and merging networks.
International Nuclear Information System (INIS)
Giri, Pulak Ranjan
2007-01-01
We perform a one-parameter family of self-adjoint extensions characterized by the parameter ω 0 . This allows us to get generic boundary conditions for the quantum oscillator on N-dimensional complex projective space (CP N ) and on its non-compact version, i.e., Lobachewski space (L N ) in the presence of a constant magnetic field. As a result, we get a family of energy spectra for the oscillator. In our formulation the already known result of this oscillator also belongs to the family. We have also obtained an energy spectrum which preserves all the symmetries (full-hidden symmetry and rotational symmetry) of the oscillator. The method of self-adjoint extensions has also been discussed for a conic oscillator in the presence of the constant magnetic field
Pietsch, Jessica; Gass, Samuel; Nebuloni, Stefano; Echegoyen, David; Riwaldt, Stefan; Baake, Christin; Bauer, Johann; Corydon, Thomas J; Egli, Marcel; Infanger, Manfred; Grimm, Daniela
2017-04-01
Human endothelial cells (ECs) were sent to the International Space Station (ISS) to determine the impact of microgravity on the formation of three-dimensional structures. For this project, an automatic experiment unit (EU) was designed allowing cell culture in space. In order to enable a safe cell culture, cell nourishment and fixation after a pre-programmed timeframe, the materials used for construction of the EUs were tested in regard to their biocompatibility. These tests revealed a high biocompatibility for all parts of the EUs, which were in contact with the cells or the medium used. Most importantly, we found polyether ether ketones for surrounding the incubation chamber, which kept cellular viability above 80% and allowed the cells to adhere as long as they were exposed to normal gravity. After assembling the EU the ECs were cultured therein, where they showed good cell viability at least for 14 days. In addition, the functionality of the automatic medium exchange, and fixation procedures were confirmed. Two days before launch, the ECs were cultured in the EUs, which were afterwards mounted on the SpaceX CRS-8 rocket. 5 and 12 days after launch the cells were fixed. Subsequent analyses revealed a scaffold-free formation of spheroids in space. Copyright © 2017 Elsevier Ltd. All rights reserved.
McCurdy, Howard E.
1992-01-01
This folder contains working papers collected to date on a NASA-sponsored history project to document the events leading up to the July 20, 1989 speech setting forth the objectives of the Space Exploration Initiative. Included are a chronology of events, briefing papers produced by the NASA Working Group laying out proposal, briefing charts used to present the proposal, a copy of the President's speech, and an essay summarizing the events that led up to the announcement. Additionally, two fo the interviews conducted as part of the project are enclosed.
Clinton, R. G., Jr.
2014-01-01
NASA, including each Mission Directorate, is investing in, experimenting with, and/or utilizing AM across a broad spectrum of applications and projects; Centers have created and are continuing to create partnerships with industry, other Government Agencies, other Centers, and Universities; In-house additive manufacturing capability enables rapid iteration of the entire design, development and testing process, increasing innovation and reducing risk and cost to projects; For deep space exploration, AM offers significant reduction to logistics costs and risk by providing ability to create on demand; There are challenges: Overwhelming message from recent JANNAF AM for Propulsion Applications TIM was "certification."; NASA will continue to work with our partners to address this and other challenges to advance the state of the art in AM and incorporate these capabilities into an array of applications from aerospace to science missions to deep space exploration.
Computer based methods for measurement of joint space width: update of an ongoing OMERACT project
Sharp, John T.; Angwin, Jane; Boers, Maarten; Duryea, Jeff; von Ingersleben, Gabriele; Hall, James R.; Kauffman, Joost A.; Landewé, Robert; Langs, Georg; Lukas, Cédric; Maillefert, Jean-Francis; Bernelot Moens, Hein J.; Peloschek, Philipp; Strand, Vibeke; van der Heijde, Désirée
2007-01-01
Computer-based methods of measuring joint space width (JSW) could potentially have advantages over scoring joint space narrowing, with regard to increased standardization, sensitivity, and reproducibility. In an early exercise, 4 different methods showed good agreement on measured change in JSW over
Asghari, Mohammad H; Azaña, José
2009-02-01
A simple all-fiber design for implementing an all-optical temporal Hilbert transformer is proposed and numerically demonstrated. We show that an all-optical Hilbert transformer can be implemented using a uniform-period fiber Bragg grating (FBG) with a properly designed amplitude-only grating apodization profile incorporating a single pi phase shift in the middle of the grating length. All-optical Hilbert transformers capable of processing arbitrary optical waveforms with bandwidths up to a few hundreds of gigahertz can be implemented using feasible FBGs.
Kusano, K.
2016-12-01
Project for Solar-Terrestrial Environment Prediction (PSTEP) is a Japanese nation-wide research collaboration, which was recently launched. PSTEP aims to develop a synergistic interaction between predictive and scientific studies of the solar-terrestrial environment and to establish the basis for next-generation space weather forecasting using the state-of-the-art observation systems and the physics-based models. For this project, we coordinate the four research groups, which develop (1) the integration of space weather forecast system, (2) the physics-based solar storm prediction, (3) the predictive models of magnetosphere and ionosphere dynamics, and (4) the model of solar cycle activity and its impact on climate, respectively. In this project, we will build the coordinated physics-based model to answer the fundamental questions concerning the onset of solar eruptions and the mechanism for radiation belt dynamics in the Earth's magnetosphere. In this paper, we will show the strategy of PSTEP, and discuss about the role and prospect of the physics-based space weather forecasting system being developed by PSTEP.
International Nuclear Information System (INIS)
Reznik, Benni; Groisman, Berry; Aharonov, Yakir
2002-01-01
We present a systematic simple method for constructing deterministic remote operations on single and multiple systems of arbitrary discrete dimensionality. These operations include remote rotations, remote interactions, and measurements. The resources needed for an operation on a two-level system are one ebit and a bidirectional communication of two cbits, and for an n-level system, a pair of entangled n-level particles and two classical 'nits'. In the latter case, there are n-1 possible distinct operations per n-level entangled pair. Similar results apply for generating interaction between a pair of remote systems, while for remote measurements only one-directional classical communication is needed. We further consider remote operations on N spatially distributed systems, and show that the number of possible distinct operations increases here exponentially, with the available number of entangled pairs that are initially distributed between the systems. Our results follow from the properties of a hybrid state-operator object (stator), which describes quantum correlations between states and operations
Approximately dual frames in Hilbert spaces and applications to Gabor frames
DEFF Research Database (Denmark)
Christensen, Ole; Laugesen, Richard S.
2011-01-01
constructed via perturbation theory. An alternative bound is derived for the rich class of Gabor frames, by using the Walnut representation of the frame operator to estimate the deviation from equality in the duality conditions. To illustrate these results, we construct explicit approximate duals of Gabor...
Hilbert Space Inner Products for PJ-symmetric Su-Schrieffer-Heeger Models
Czech Academy of Sciences Publication Activity Database
Růžička, František
2015-01-01
Roč. 54, č. 11 (2015), s. 4154-4163 ISSN 0020-7748 Institutional support: RVO:61389005 Keywords : Su-Schrieffer-Heeger model * physical inner products * complete set of pseudometrics * exceptional points Subject RIV: BE - Theoretical Physics Impact factor: 1.041, year: 2015
A new look at the harmonic oscillator problem in a finite-dimensional Hilbert space
International Nuclear Information System (INIS)
Bagchi, B.
1995-01-01
In this Letter some basic properties of a truncated oscillator are studied. By using finite-dimensional representation matrices of the truncated oscillator we construct new parasupersymmetric schemes and remark on their relevance to the transition operators of the non-interacting N-level system endowed with bosonic modes. ((orig.))
Moment problems in Hilbert space with applications to magnetic resonance imaging
International Nuclear Information System (INIS)
Zwaan, Marcel.
1991-01-01
This thesis is concerned with the mathematical and computational aspects of reconstruction techniques by means of magnetic resonance imaging, in particular for the time-dependent case, referred to as dynamic MRI. The main subjects are: a mathematical framework for dynamic MRI reconstruction; analytic solutions, numerical algorithms and development of reconstruction techniques; stability analysis of the reconstruction algorithms; comparison between these algorithms. (author). 63 refs.; 38 figs.; 5 tabs
Applications of automata and graphs: Labeling operators in Hilbert space. II
International Nuclear Information System (INIS)
Cho, Ilwoo; Jorgensen, Palle E. T.
2009-01-01
We introduced a family of infinite graphs directly associated with a class of von Neumann automaton model A G . These are finite state models used in symbolic dynamics: stimuli models and in control theory. In the context of groupoid von Neumann algebras, and an associated fractal group, we prove a classification theorem for representations of automata.
A Hilbert Space Geometric Representation of Shared Awareness and Joint Decision Making
Canan, Mustafa
2017-01-01
Two people in the same situation may ascribe very different meanings to their experiences. They will form different awareness, reacting differently to shared information. Various factors can give rise to this behavior. These factors include, but are not limited to, prior knowledge, training, biases, cultural factors, social factors, team vs.…
Macroscopicity of quantum superpositions on a one-parameter unitary path in Hilbert space
Volkoff, T. J.; Whaley, K. B.
2014-12-01
We analyze quantum states formed as superpositions of an initial pure product state and its image under local unitary evolution, using two measurement-based measures of superposition size: one based on the optimal quantum binary distinguishability of the branches of the superposition and another based on the ratio of the maximal quantum Fisher information of the superposition to that of its branches, i.e., the relative metrological usefulness of the superposition. A general formula for the effective sizes of these states according to the branch-distinguishability measure is obtained and applied to superposition states of N quantum harmonic oscillators composed of Gaussian branches. Considering optimal distinguishability of pure states on a time-evolution path leads naturally to a notion of distinguishability time that generalizes the well-known orthogonalization times of Mandelstam and Tamm and Margolus and Levitin. We further show that the distinguishability time provides a compact operational expression for the superposition size measure based on the relative quantum Fisher information. By restricting the maximization procedure in the definition of this measure to an appropriate algebra of observables, we show that the superposition size of, e.g., NOON states and hierarchical cat states, can scale linearly with the number of elementary particles comprising the superposition state, implying precision scaling inversely with the total number of photons when these states are employed as probes in quantum parameter estimation of a 1-local Hamiltonian in this algebra.
Alam, Md. Ashad; Fukumizu, Kenji; Wang, Yu-Ping
2016-01-01
To the best of our knowledge, there are no general well-founded robust methods for statistical unsupervised learning. Most of the unsupervised methods explicitly or implicitly depend on the kernel covariance operator (kernel CO) or kernel cross-covariance operator (kernel CCO). They are sensitive to contaminated data, even when using bounded positive definite kernels. First, we propose robust kernel covariance operator (robust kernel CO) and robust kernel crosscovariance operator (robust kern...
Dirac-like operators on the Hilbert space of differential forms on manifolds with boundaries
Pérez-Pardo, Juan Manuel
The problem of self-adjoint extensions of Dirac-type operators in manifolds with boundaries is analyzed. The boundaries might be regular or non-regular. The latter situation includes point-like interactions, also called delta-like potentials, in manifolds of dimension higher than one. Self-adjoint boundary conditions for the case of dimension 2 are obtained explicitly.
Barron, Darcy; Peticolas, Laura; Multiverse Team at UC Berkeley's Space Sciences Lab
2018-01-01
The Advancing Space Science through Undergraduate Research Experience (ASSURE) summer REU program is an NSF-funded REU site at the Space Sciences Lab at UC Berkeley that first started in summer 2014. The program recruits students from all STEM majors, targeting underserved students including community college students and first-generation college students. The students have little or no research experience and a wide variety of academic backgrounds, but have a shared passion for space sciences and astronomy. We will describe our program's structure and the components we have found successful in preparing and supporting both the students and their research advisors for their summer research projects. This includes an intensive first week of introductory lectures and tutorials at the start of the program, preparing students for working in an academic research environment. The program also employs a multi-tiered mentoring system, with layers of support for the undergraduate student cohort, as well as graduate student and postdoctoral research advisors.
SPACE PHYSICS: Developing resources for astrophysics at A-level: the TRUMP Astrophysics project
Swinbank, Elizabeth
1997-01-01
After outlining the astrophysical options now available in A-level physics syllabuses, this paper notes some of the particular challenges facing A-level teachers and students who chose these options and describes a project designed to support them. The paper highlights some key features of the project that could readily be incorporated into other areas of physics curriculum development.
Aaron, Kim
1991-01-01
The Sample Acquisition, Analysis, and Preservation Project is summarized in outline and graphic form. The objective of the project is to develop component and system level technology to enable the unmanned collection, analysis and preservation of physical, chemical and mineralogical data from the surface of planetary bodies. Technology needs and challenges are identified and specific objectives are described.
Kottke, T. E.; Little Finger, L.; Trapp, M. A.; Panser, L. A.; Novotny, P. J.
1996-01-01
OBJECTIVE: To determine the response of participants to the Pine Ridge-Mayo National Aeronautics and Space Administration telemedicine project. DESIGN: We describe a 3-month demonstration project of medical education and clinical consultations conducted by means of satellite transmission. Postparticipation questionnaires and a postproject survey were used to assess the success of the activity. MATERIAL AND METHODS: Patients and employees at the Pine Ridge Indian Health Service Hospital in southwestern South Dakota and employees at Mayo Clinic Rochester participated in a telemedicine project, after which they completed exit surveys and a postproject questionnaire to ascertain the acceptability of this mode of health care. RESULTS: Almost all Pine Ridge and Mayo Clinic participants viewed the project as beneficial. The educational sessions received favorable evaluations, and almost two-thirds of the patients who completed evaluations thought the consultation had contributed to their medical care. More than 90% of the respondents from Pine Ridge and more than 85% of the respondents from Mayo Clinic Rochester said that they would recommend participation in this project to others. More than 90% of respondents from Pine Ridge and 80% of Mayo respondents agreed with the statement that the project should continue. CONCLUSION: These data suggest that a program of clinical consultation services, professional education, and patient education available by telemedicine might be viewed as beneficial.
SO-QT: Collaborative Tool to Project the Future Space Object Population
Stupl, Jan
2017-01-01
Earth orbit gets increasingly congested, a challenge to space operators, both in governments and industry. We present a web tool that provides: 1) data on todays and the historic space object environments, by aggregating object-specific tracking data; and 2) future trends through a collaboration platform to collect information on planed launches. The collaborative platform enables experts to pool and compare their data in order to generate future launch scenarios. The tool is intended to support decision makers and mission designers while they investigate future missions and scholars as they develop strategies for space traffic management.
A scientific operations plan for the NASA space telescope. [ground support systems, project planning
West, D. K.; Costa, S. R.
1975-01-01
A ground system is described which is compatible with the operational requirements of the space telescope. The goal of the ground system is to minimize the cost of post launch operations without seriously compromising the quality and total throughput of space telescope science, or jeopardizing the safety of the space telescope in orbit. The resulting system is able to accomplish this goal through optimum use of existing and planned resources and institutional facilities. Cost is also reduced and efficiency in operation increased by drawing on existing experience in interfacing guest astronomers with spacecraft as well as mission control experience obtained in the operation of present astronomical spacecraft.
Independence and totalness of subspaces in phase space methods
Vourdas, A.
2018-04-01
The concepts of independence and totalness of subspaces are introduced in the context of quasi-probability distributions in phase space, for quantum systems with finite-dimensional Hilbert space. It is shown that due to the non-distributivity of the lattice of subspaces, there are various levels of independence, from pairwise independence up to (full) independence. Pairwise totalness, totalness and other intermediate concepts are also introduced, which roughly express that the subspaces overlap strongly among themselves, and they cover the full Hilbert space. A duality between independence and totalness, that involves orthocomplementation (logical NOT operation), is discussed. Another approach to independence is also studied, using Rota's formalism on independent partitions of the Hilbert space. This is used to define informational independence, which is proved to be equivalent to independence. As an application, the pentagram (used in discussions on contextuality) is analysed using these concepts.
Johnston, John; Mosier, Mark; Howard, Joe; Hyde, Tupper; Parrish, Keith; Ha, Kong; Liu, Frank; McGinnis, Mark
2004-01-01
This paper presents viewgraphs about structural analysis activities and integrated modeling for the James Webb Space Telescope (JWST). The topics include: 1) JWST Overview; 2) Observatory Structural Models; 3) Integrated Performance Analysis; and 4) Future Work and Challenges.
Flexible Graphene-based Energy Storage Devices for Space Application Project
Calle, Carlos I.
2014-01-01
Develop prototype graphene-based reversible energy storage devices that are flexible, thin, lightweight, durable, and that can be easily attached to spacesuits, rovers, landers, and equipment used in space.
National Aeronautics and Space Administration — Develop new cell and blanket technologies and manufacturing processes that reduce overall array costs•Cells: develop new cell technology comparable to SOA with...
Development of Space Life Supporting System Using Radiation Technology (Top Brand Project)
Energy Technology Data Exchange (ETDEWEB)
Lee, Ju Woon; Kim, Jae Hun; Song, Beom Seok; Choi, Jong Il; Yoon, Yo Han; Park, Jin Kyu; Park, Jae Nam; Han, In Jun; Lee, Yoon Jong [KAERI, Daejeon (Korea, Republic of)
2010-08-15
To simulate the space environment of microgravity and expose to space radiation, Hindlimb Suspension Model was established in Gamma Phytotron. Hindlimb suspended group exposed to irradiation, non-suspended group not exposed to irradiation, and non-suspended group exposed to irradiation were experimented for 2 weeks at the dose rate of 3.2 mSV/day. The results showed that muscle weight was decreased by suspension. To develop the countermeasure to physiological changes in space environment, the peptides from soy beam was selected to evaluate the effect with the space environment simulation model. Suing the microscopic and fluorescent images, the growth of microorganisms were detected. The species were identified based on primer-targeted gene sequence analysis. Also, the radiation resistance of species was defined. To research on sustainable nutritional supply and improvement of human physiology in space environment, four kinds of new Korean space foods (Bulgogi, Bibimbap, Seaweed soup, and Mulberry beverage) were developed using the irradiation technology and certified as space foods by the Russian Institute of Biomedical Problems. The contract on joint research of MARS-500 between KAERI and IBMP was made. In the experiment, crews for expedition to Mars will eat Korean space foods (Bulgogi, Bibimbap, Seaweed soup, Mulberry beverage, Kimchi, Sujeonggwa) for 120 days, then their immunity will be examined and compared with it on the ground. The developed technology and know-how could be spun out to the various fields, such as aircraft, automobile, military, information and communication, bio technologies. Moreover, the results obtained from this research can be used for the further development for military use or special food area such as foods for patient
Development of Space Life Supporting System Using Radiation Technology (Top Brand Project)
International Nuclear Information System (INIS)
Lee, Ju Woon; Kim, Jae Hun; Song, Beom Seok; Choi, Jong Il; Yoon, Yo Han; Park, Jin Kyu; Park, Jae Nam; Han, In Jun; Lee, Yoon Jong
2010-08-01
To simulate the space environment of microgravity and expose to space radiation, Hindlimb Suspension Model was established in Gamma Phytotron. Hindlimb suspended group exposed to irradiation, non-suspended group not exposed to irradiation, and non-suspended group exposed to irradiation were experimented for 2 weeks at the dose rate of 3.2 mSV/day. The results showed that muscle weight was decreased by suspension. To develop the countermeasure to physiological changes in space environment, the peptides from soy beam was selected to evaluate the effect with the space environment simulation model. Suing the microscopic and fluorescent images, the growth of microorganisms were detected. The species were identified based on primer-targeted gene sequence analysis. Also, the radiation resistance of species was defined. To research on sustainable nutritional supply and improvement of human physiology in space environment, four kinds of new Korean space foods (Bulgogi, Bibimbap, Seaweed soup, and Mulberry beverage) were developed using the irradiation technology and certified as space foods by the Russian Institute of Biomedical Problems. The contract on joint research of MARS-500 between KAERI and IBMP was made. In the experiment, crews for expedition to Mars will eat Korean space foods (Bulgogi, Bibimbap, Seaweed soup, Mulberry beverage, Kimchi, Sujeonggwa) for 120 days, then their immunity will be examined and compared with it on the ground. The developed technology and know-how could be spun out to the various fields, such as aircraft, automobile, military, information and communication, bio technologies. Moreover, the results obtained from this research can be used for the further development for military use or special food area such as foods for patient
Hörmander spaces, interpolation, and elliptic problems
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
Martins, Luis Gustavo Nogueira; Stefanello, Michel Baptistella; Degrazia, Gervásio Annes; Acevedo, Otávio Costa; Puhales, Franciano Scremin; Demarco, Giuliano; Mortarini, Luca; Anfossi, Domenico; Roberti, Débora Regina; Costa, Felipe Denardin; Maldaner, Silvana
2016-11-01
In this study we analyze natural complex signals employing the Hilbert-Huang spectral analysis. Specifically, low wind meandering meteorological data are decomposed into turbulent and non turbulent components. These non turbulent movements, responsible for the absence of a preferential direction of the horizontal wind, provoke negative lobes in the meandering autocorrelation functions. The meandering characteristic time scales (meandering periods) are determined from the spectral peak provided by the Hilbert-Huang marginal spectrum. The magnitudes of the temperature and horizontal wind meandering period obtained agree with the results found from the best fit of the heuristic meandering autocorrelation functions. Therefore, the new method represents a new procedure to evaluate meandering periods that does not employ mathematical expressions to represent observed meandering autocorrelation functions.
Hilbert Series and Mixed Branches of T[SU(N)] theories
Energy Technology Data Exchange (ETDEWEB)
Carta, Federico [Departamento de Física Teórica and Instituto de Física Teórica UAM-CSIC,Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Hayashi, Hirotaka [Departamento de Física Teórica and Instituto de Física Teórica UAM-CSIC,Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Tokai University,4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)
2017-02-07
We consider mixed branches of 3dN=4T[SU(N)] theory. We compute the Hilbert series of the Coulomb branch part of the mixed branch from a restriction rule acting on the Hilbert series of the full Coulomb branch that will truncate the magnetic charge summation only to the subset of BPS dressed monopole operators that arise in the Coulomb branch sublocus where the mixed branch stems. This restriction can be understood directly from the type IIB brane picture by a relation between the magnetic charges of the monopoles and brane position moduli. We also apply the restriction rule to the Higgs branch part of a given mixed branch by exploiting 3d mirror symmetry. Both cases show complete agreement with the results calculated by different methods.
International Nuclear Information System (INIS)
Mei Jianwei
2012-01-01
We suggest a way to study possible conformal symmetries on black hole horizons. We do this by carrying out a Kaluza-Klein-like reduction of the Einstein-Hilbert action along the ignorable coordinates of stationary and axisymmetric black holes. Rigid diffeomorphism invariance of the m-ignorable coordinates then becomes a global SL(m, R) gauge symmetry of the reduced action. Related to each non-vanishing angular velocity, there is a particular SL(2, R) subgroup, which can be extended to the Witt algebra on the black hole horizons. The classical Einstein-Hilbert action thus has k-copies of infinite-dimensional conformal symmetries on a given black hole horizon, with k being the number of non-vanishing angular velocities of the black hole. (paper)
Frequency hopping signal detection based on wavelet decomposition and Hilbert-Huang transform
Zheng, Yang; Chen, Xihao; Zhu, Rui
2017-07-01
Frequency hopping (FH) signal is widely adopted by military communications as a kind of low probability interception signal. Therefore, it is very important to research the FH signal detection algorithm. The existing detection algorithm of FH signals based on the time-frequency analysis cannot satisfy the time and frequency resolution requirement at the same time due to the influence of window function. In order to solve this problem, an algorithm based on wavelet decomposition and Hilbert-Huang transform (HHT) was proposed. The proposed algorithm removes the noise of the received signals by wavelet decomposition and detects the FH signals by Hilbert-Huang transform. Simulation results show the proposed algorithm takes into account both the time resolution and the frequency resolution. Correspondingly, the accuracy of FH signals detection can be improved.
Directory of Open Access Journals (Sweden)
Isti Qomah
2017-01-01
Full Text Available Kerusakan batang rotor merupakan salah satu jenis kerusakan pada motor induksi yang dapat menyebabkan masalah serius. Kerusakan tersebut dapat mencapai 5% - 10% dari seluruh kasus gangguan motor induksi. Oleh karena itu, perlu adanya diagnosis awal yang mendeteksi adanya gangguan pada rotor motor induksi, agar dapat dilakukan perbaikan lebih cepat dan tanggap sebelum terjadi gangguan yang lebih besar. Tugas Akhir ini membahas terkait teknik deteksi kerusakan batang rotor pada motor induksi dengan menggunakan analisis arus mula. Sistem yang digunakan berbasis decomposition wavelet transform terlebih dahulu kemudian dilanjutkan dengan analisis berbasis hilbert transform sebagai perangkat pengolahan sinyal sehingga mampu mendeteksi motor dalam keadaan sehat atau mengalami kerusakan. Pengujian sistem dilakukan dalam beberapa kondisi, yaitu kondisi tanpa beban dan berbeban. Selain itu, kondisi yang diberikan adalah kecacatan mulai dai 1BRB hingga 3BRB. Hasil pengujian membuktikan bahwa decomposition wavelet transform dan Hilbert transform mampu mendeteksi perbedaan kondisi pada motor induksi normal ataupun rusak pada batang rotor.
Explicit solution of Riemann-Hilbert problems for the Ernst equation
Klein, C.; Richter, O.
1998-01-01
Riemann-Hilbert problems are an important solution technique for completely integrable differential equations. They are used to introduce a free function in the solutions which can be used at least in principle to solve initial or boundary value problems. But even if the initial or boundary data can be translated into a Riemann-Hilbert problem, it is in general impossible to obtain explicit solutions. In the case of the Ernst equation, however, this is possible for a large class because the matrix problem can be shown to be gauge equivalent to a scalar one on a hyperelliptic Riemann surface that can be solved in terms of theta functions. As an example we discuss the rigidly rotating dust disk.