Simulating Nonlinear Dynamics of Deployable Space Structures Project
National Aeronautics and Space Administration — To support NASA's vital interest in developing much larger solar array structures over the next 20 years, MotionPort LLC's Phase I SBIR project will strengthen...
Abdel-Salam, Emad A-B; Hassan, Gmal F
2015-01-01
In this paper, the fractional projective Riccati expansion method is proposed to solve fractional differential equations. To illustrate the effectiveness of the method, we discuss the space-time fractional Burgers equation, the space-time fractional mKdV equation and time fractional biological population model. The solutions are expressed in terms of fractional hyperbolic functions. These solutions are useful to understand the mechanisms of the complicated nonlinear physical phenomena and fractional differential equations. Among these solutions, some are found for the first time. The fractal index for the obtained results is equal to one. Counter examples to compute the fractal index are introduced in appendix.
Nonlinear field space cosmology
Mielczarek, Jakub; Trześniewski, Tomasz
2017-08-01
We consider the FRW cosmological model in which the matter content of the Universe (playing the role of an inflaton or quintessence) is given by a novel generalization of the massive scalar field. The latter is a scalar version of the recently introduced nonlinear field space theory, where the physical phase space of a given field is assumed to be compactified at large energies. For our analysis, we choose the simple case of a field with the spherical phase space and endow it with the generalized Hamiltonian analogous to the XXZ Heisenberg model, normally describing a system of spins in condensed matter physics. Subsequently, we study both the homogenous cosmological sector and linear perturbations of such a test field. In the homogenous sector, we find that nonlinearity of the field phase space is becoming relevant for large volumes of the Universe and can lead to a recollapse, and possibly also at very high energies, leading to the phase of a bounce. Quantization of the field is performed in the limit where the nontrivial nature of its phase space can be neglected, while there is a nonvanishing contribution from the Lorentz symmetry breaking term of the Hamiltonian. As a result, in the leading order of the XXZ anisotropy parameter, we find that the inflationary spectral index remains unmodified with respect to the standard case but the total amplitude of perturbations is subject to a correction. The Bunch-Davies vacuum state also becomes appropriately corrected. The proposed new approach is bringing cosmology and condensed matter physics closer together, which may turn out to be beneficial for both disciplines.
Nonlinear Optical Terahertz Technology Project
National Aeronautics and Space Administration — Our approach is based on high-Q optical WGM resonators made with a nonlinear crystal. Such resonators have been demonstrated to dramatically enhance nonlinear...
Gradiometer Based on Nonlinear Magneto-Optic Rotation Project
National Aeronautics and Space Administration — This Phase I SBIR project will demonstrate sensitive measurements of magnetic field gradients by nonlinear atomic spectroscopy. The gradients are determined by...
The Nonlinear Field Space Theory
Mielczarek, Jakub; Trześniewski, Tomasz
2016-08-01
In recent years the idea that not only the configuration space of particles, i.e. spacetime, but also the corresponding momentum space may have nontrivial geometry has attracted significant attention, especially in the context of quantum gravity. The aim of this letter is to extend this concept to the domain of field theories, by introducing field spaces (i.e. phase spaces of field values) that are not affine spaces. After discussing the motivation and general aspects of our approach we present a detailed analysis of the prototype (quantum) Nonlinear Field Space Theory of a scalar field on the Minkowski background. We show that the nonlinear structure of a field space leads to numerous interesting predictions, including: non-locality, generalization of the uncertainty relations, algebra deformations, constraining of the maximal occupation number, shifting of the vacuum energy and renormalization of the charge and speed of propagation of field excitations. Furthermore, a compact field space is a natural way to implement the "Principle of finiteness" of physical theories, which once motivated the Born-Infeld theory. Thus the presented framework has a variety of potential applications in the theories of fundamental interactions (e.g. quantum gravity), as well as in condensed matter physics (e.g. continuous spin chains), and can shed new light on the issue of divergences in quantum field theories.
The Nonlinear Field Space Theory
Energy Technology Data Exchange (ETDEWEB)
Mielczarek, Jakub, E-mail: jakub.mielczarek@uj.edu.pl [Institute of Physics, Jagiellonian University, ul. Łojasiewicza 11, 30-348 Kraków (Poland); Trześniewski, Tomasz, E-mail: tbwbt@ift.uni.wroc.pl [Institute of Physics, Jagiellonian University, ul. Łojasiewicza 11, 30-348 Kraków (Poland); Institute for Theoretical Physics, University of Wrocław, pl. Borna 9, 50-204 Wrocław (Poland)
2016-08-10
In recent years the idea that not only the configuration space of particles, i.e. spacetime, but also the corresponding momentum space may have nontrivial geometry has attracted significant attention, especially in the context of quantum gravity. The aim of this letter is to extend this concept to the domain of field theories, by introducing field spaces (i.e. phase spaces of field values) that are not affine spaces. After discussing the motivation and general aspects of our approach we present a detailed analysis of the prototype (quantum) Nonlinear Field Space Theory of a scalar field on the Minkowski background. We show that the nonlinear structure of a field space leads to numerous interesting predictions, including: non-locality, generalization of the uncertainty relations, algebra deformations, constraining of the maximal occupation number, shifting of the vacuum energy and renormalization of the charge and speed of propagation of field excitations. Furthermore, a compact field space is a natural way to implement the “Principle of finiteness” of physical theories, which once motivated the Born–Infeld theory. Thus the presented framework has a variety of potential applications in the theories of fundamental interactions (e.g. quantum gravity), as well as in condensed matter physics (e.g. continuous spin chains), and can shed new light on the issue of divergences in quantum field theories.
The Nonlinear Field Space Theory
Directory of Open Access Journals (Sweden)
Jakub Mielczarek
2016-08-01
Full Text Available In recent years the idea that not only the configuration space of particles, i.e. spacetime, but also the corresponding momentum space may have nontrivial geometry has attracted significant attention, especially in the context of quantum gravity. The aim of this letter is to extend this concept to the domain of field theories, by introducing field spaces (i.e. phase spaces of field values that are not affine spaces. After discussing the motivation and general aspects of our approach we present a detailed analysis of the prototype (quantum Nonlinear Field Space Theory of a scalar field on the Minkowski background. We show that the nonlinear structure of a field space leads to numerous interesting predictions, including: non-locality, generalization of the uncertainty relations, algebra deformations, constraining of the maximal occupation number, shifting of the vacuum energy and renormalization of the charge and speed of propagation of field excitations. Furthermore, a compact field space is a natural way to implement the “Principle of finiteness” of physical theories, which once motivated the Born–Infeld theory. Thus the presented framework has a variety of potential applications in the theories of fundamental interactions (e.g. quantum gravity, as well as in condensed matter physics (e.g. continuous spin chains, and can shed new light on the issue of divergences in quantum field theories.
Some nonlinear space decomposition algorithms
Energy Technology Data Exchange (ETDEWEB)
Tai, Xue-Cheng; Espedal, M. [Univ. of Bergen (Norway)
1996-12-31
Convergence of a space decomposition method is proved for a general convex programming problem. The space decomposition refers to methods that decompose a space into sums of subspaces, which could be a domain decomposition or a multigrid method for partial differential equations. Two algorithms are proposed. Both can be used for linear as well as nonlinear elliptic problems and they reduce to the standard additive and multiplicative Schwarz methods for linear elliptic problems. Two {open_quotes}hybrid{close_quotes} algorithms are also presented. They converge faster than the additive one and have better parallelism than the multiplicative method. Numerical tests with a two level domain decomposition for linear, nonlinear and interface elliptic problems are presented for the proposed algorithms.
Nonlinear projective filtering in a data stream
Schreiber, T; Schreiber, Thomas; Richter, Marcus
1998-01-01
We introduce a modified algorithm to perform nonlinear filtering of a time series by locally linear phase space projections. Unlike previous implementations, the algorithm can be used not only for a posteriori processing but includes the possibility to perform real time filtering in a data stream. The data base that represents the phase space structure generated by the data is updated dynamically. This also allows filtering of non-stationary signals and dynamic parameter adjustment. We discuss exemplary applications, including the real time extraction of the fetal electrocardiogram from abdominal recordings.
Computational Models for Nonlinear Aeroelastic Systems Project
National Aeronautics and Space Administration — Clear Science Corp. and Duke University propose to develop and demonstrate new and efficient computational methods of modeling nonlinear aeroelastic systems. The...
Model Updating Nonlinear System Identification Toolbox Project
National Aeronautics and Space Administration — ZONA Technology (ZONA) proposes to develop an enhanced model updating nonlinear system identification (MUNSID) methodology that utilizes flight data with...
Nonlinear approximation in alpha-modulation spaces
DEFF Research Database (Denmark)
Borup, Lasse; Nielsen, Morten
2006-01-01
The α-modulation spaces are a family of spaces that contain the Besov and modulation spaces as special cases. In this paper we prove that brushlet bases can be constructed to form unconditional and even greedy bases for the α-modulation spaces. We study m -term nonlinear approximation with brushlet...... bases, and give complete characterizations of the associated approximation spaces in terms of α-modulation spaces....
Space curves, anholonomy and nonlinearity
Indian Academy of Sciences (India)
Radha Balakrishnan
2005-04-01
Using classical differential geometry, we discuss the phenomenon of anholonomy that gets associated with a static and a moving curve. We obtain the expressions for the respective geometric phases in the two cases and interpret them. We show that there is a close connection between anholonomy and nonlinearity in a wide class of nonlinear systems.
Nonlinear Oscillators in Space Physics
Lester,Daniel; Thronson, Harley
2011-01-01
We discuss dynamical systems that produce an oscillation without an external time dependent source. Numerical results are presented for nonlinear oscillators in the Em1h's atmosphere, foremost the quasi-biennial oscillation (QBOl. These fluid dynamical oscillators, like the solar dynamo, have in common that one of the variables in a governing equation is strongly nonlinear and that the nonlinearity, to first order, has particular form. of 3rd or odd power. It is shown that this form of nonlinearity can produce the fundamental li'equency of the internal oscillation. which has a period that is favored by the dynamical condition of the fluid. The fundamental frequency maintains the oscillation, with no energy input to the system at that particular frequency. Nonlinearities of 2nd or even power could not maintain the oscillation.
Indian Academy of Sciences (India)
Usha N Bhosle
2013-08-01
We compute the cohomology of the Picard bundle on the desingularization $\\overline{J}^d (Y)$ of the compactified Jacobian of an irreducible nodal curve . We use it to compute the cohomology classes of the Brill–Noether loci in $\\overline{J}^d(Y)$. We show that the moduli space of morphisms of a fixed degree from to a projective space has a smooth compactification. As another application of the cohomology of the Picard bundle, we compute a top intersection number for the moduli space confirming the Vafa–Intriligator formulae in the nodal case.
Non-Linear Relativity in Position Space
Kimberly, D; Medeiros-Neto, J F; Kimberly, Dagny; Magueijo, João; Medeiros, João
2003-01-01
We propose two methods for obtaining the dual of non-linear relativity as previously formulated in momentum space. In the first we allow for the (dual) position space to acquire a non-linear representation of the Lorentz group independently of the chosen representation in momentum space. This requires a non-linear definition for the invariant contraction between momentum and position spaces. The second approach, instead, respects the linearity of the invariant contraction. This fully fixes the dual of momentum space and dictates a set of energy-dependent space-time Lorentz transformations. We discuss a variety of physical implications that would distinguish these two strategies. We also show how they point to two rather distinct formulations of theories of gravity with an invariant energy and/or length scale.
Lagrangian Space Nonlinear $E$-mode clustering
Yu, Hao-Ran; Zhu, Hong-Ming
2016-01-01
We study the nonlinear $E$-mode clustering in Lagrangian space by using large scale structure (LSS) $N$-body simulations and use the displacement field information in Lagrangian space to recover the primordial linear density field. We find that, compared to Eulerian nonlinear density fields, the $E$-mode displacement fields in Lagrangian space improves the cross-correlation scale $k$ with initial density field by factor of 6 $\\sim$ 7, containing 2 orders of magnitude more primordial information. This illustrates ability of potential density reconstruction algorithms, to improve the baryonic acoustic oscillation (BAO) measurements from current and future large scale structure surveys.
Model Updating Nonlinear System Identification Toolbox Project
National Aeronautics and Space Administration — ZONA Technology proposes to develop an enhanced model updating nonlinear system identification (MUNSID) methodology by adopting the flight data with state-of-the-art...
Parallel Nonlinear Optimization for Astrodynamic Navigation Project
National Aeronautics and Space Administration — CU Aerospace proposes the development of a new parallel nonlinear program (NLP) solver software package. NLPs allow the solution of complex optimization problems,...
Computational Models for Nonlinear Aeroelastic Systems Project
National Aeronautics and Space Administration — Clear Science Corp. and Duke University propose to develop and demonstrate a new and efficient computational method of modeling nonlinear aeroelastic systems. The...
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
Nonlinear projective filtering; 1, Application to real time series
Schreiber, T
1998-01-01
We discuss applications of nonlinear filtering of time series by locally linear phase space projections. Noise can be reduced whenever the error due to the manifold approximation is smaller than the noise in the system. Examples include the real time extraction of the fetal electrocardiogram from abdominal recordings.
Nonextensivity, Complexity and Nonlinearity in Space Plasmas
Pavlos, G. P.
2017-01-01
Experimental time series, extracted from many and different space plasma systems corresponding to, solar wind, magnetospheric and other space plasma systems reveal common dynamical, geometrical, or statistical characteristics. Such characteristics are the low dimensionality, the typical intermittent turbulence multifractality, the temporal or spatial multiscale correlations and power laws scale invariance, non Gaoussianity and others. This universal aspect of experimental time series profiles was understood in the past as the chaos or SOC universality. However, after two or three decades of theoretical development in understanding of the nonlinearity and complexity, we can give a more compact theoretical description of the underline universal physical processes that produce the experimental time series complexity. Finally, in this study, we present and explain the modern complex set of theoretical concepts from the point of view of physics as the unification theory of nonlinear theory of non-equilibrium plasma systems as well as the presupposed theoretical framework of time series analysis of space plasma charachteristics.
Isospectral Metrics on Projective Spaces
Rueckriemen, Ralf
2011-01-01
We construct isospectral non isometric metrics on real and complex projective space. We recall the construction using isometric torus actions by Carolyn Gordon in chapter 2. In chapter 3 we will recall some facts about complex projective space. In chapter 4 we build the isospectral metrics. Chapter 5 is devoted to the non isometry proof of the metrics built in chapter 4. In chapter 6 isospectral metrics on real projective space are derived from metrics on the sphere.
Control of nonlinear flexible space structures
Shi, Jianjun
With the advances made in computer technology and efficiency of numerical algorithms over last decade, the MPC strategies have become quite popular among control community. However, application of MPC or GPC to flexible space structure control has not been explored adequately in the literature. The work presented in this thesis primarily focuses on application of GPC to control of nonlinear flexible space structures. This thesis is particularly devoted to the development of various approximate dynamic models, design and assessment of candidate controllers, and extensive numerical simulations for a realistic multibody flexible spacecraft, namely, Jupiter Icy Moons Orbiter (JIMO)---a Prometheus class of spacecraft proposed by NASA for deep space exploratory missions. A stable GPC algorithm is developed for Multi-Input-Multi-Output (MIMO) systems. An end-point weighting (penalty) is used in the GPC cost function to guarantee the nominal stability of the closed-loop system. A method is given to compute the desired end-point state from the desired output trajectory. The methodologies based on Fake Algebraic Riccati Equation (FARE) and constrained nonlinear optimization, are developed for synthesis of state weighting matrix. This makes this formulation more practical. A stable reconfigurable GPC architecture is presented and its effectiveness is demonstrated on both aircraft as well as spacecraft model. A representative in-orbit maneuver is used for assessing the performance of various control strategies using various design models. Different approximate dynamic models used for analysis include linear single body flexible structure, nonlinear single body flexible structure, and nonlinear multibody flexible structure. The control laws evaluated include traditional GPC, feedback linearization-based GPC (FLGPC), reconfigurable GPC, and nonlinear dissipative control. These various control schemes are evaluated for robust stability and robust performance in the presence of
National Aeronautics and Space Administration — The overall goal of the project is to develop reliable reduced order modeling technologies to automatically generate nonlinear, parameter-varying (PV),...
Processing Approach of Non-linear Adjustment Models in the Space of Non-linear Models
Institute of Scientific and Technical Information of China (English)
LI Chaokui; ZHU Qing; SONG Chengfang
2003-01-01
This paper investigates the mathematic features of non-linear models and discusses the processing way of non-linear factors which contributes to the non-linearity of a nonlinear model. On the basis of the error definition, this paper puts forward a new adjustment criterion, SGPE.Last, this paper investigates the solution of a non-linear regression model in the non-linear model space and makes the comparison between the estimated values in non-linear model space and those in linear model space.
Resiliant Space Systems Project
National Aeronautics and Space Administration — The task goal is to develop and demonstrate an innovative software architecture, the “Resilient Spacecraft Executive”, that will enable highly-resilient...
National Aeronautics and Space Administration — Individual talks by JPL and Caltech experts on graphene to present the different ambits of application in which graphene is currently being used on campus,...
Nonlinear Time Reversal Acoustic Method of Friction Stir Weld Assessment Project
National Aeronautics and Space Administration — The goal of the project is demonstration of the feasibility of Friction Stir Weld (FSW) assessment by novel Nonlinear Time Reversal Acoustic (TRA) method. Time...
Coherent states in projected Hilbert spaces
Drummond, P. D.; Reid, M. D.
2016-12-01
Coherent states in a projected Hilbert space have many useful properties. When there are conserved quantities, a representation of the entire Hilbert space is not necessary. The same issue arises when conditional observations are made with postselected measurement results. In these cases, only a part of the Hilbert space needs to be represented, and one can define this restriction by way of a projection operator. Here coherent state bases and normally ordered phase-space representations are introduced for treating such projected Hilbert spaces, including existence theorems and dynamical equations. These techniques are very useful in studying novel optical or microwave integrated photonic quantum technologies, such as boson sampling or Josephson quantum computers. In these cases, states become strongly restricted due to inputs, nonlinearities, or conditional measurements. This paper focuses on coherent phase states, which have especially simple properties. Practical applications are reported on calculating recurrences in anharmonic oscillators, the effects of arbitrary phase noise on Schrödinger cat fringe visibility, and on boson sampling interferometry for large numbers of modes.
Space market model development project
Bishop, Peter C.
1987-01-01
The objectives of the research program, Space Market Model Development Project, (Phase 1) were: (1) to study the need for business information in the commercial development of space; and (2) to propose a design for an information system to meet the identified needs. Three simultaneous research strategies were used in proceeding toward this goal: (1) to describe the space business information which currently exists; (2) to survey government and business representatives on the information they would like to have; and (3) to investigate the feasibility of generating new economical information about the space industry.
BERGMAN TYPE PROJECTIONS ON Lp SPACES
Institute of Scientific and Technical Information of China (English)
Kehe Zhu
2005-01-01
The paper is a survey on the action of Bergman type projections on various Lp spaces. The focus is on three types of holomorphic function spaces: weighted Bergman spaces, the Bloch space, and diagonal Besov spaces.
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...
Trade Space Analysis: Rotational Analyst Research Project
2015-09-01
TRAC-M-TR-15-028 September 2015 Trade Space Analysis: Rotational Analyst Research Project TRADOC Analysis...PAGE INTENTIONALLY LEFT BLANK TRAC-M-TR-15-028 September 2015 Trade Space Analysis: Rotational Analyst Research Project...NUMBERS Trade Space Analysis : Rotational Analyst Research Project TRAC Project Code 060128 6. AUTHOR(S) Kirstin D Smead 7. PERFORMING
Projective duality and homogeneous spaces
Tevelev, E A
2006-01-01
Projective duality is a very classical notion naturally arising in various areas of mathematics, such as algebraic and differential geometry, combinatorics, topology, analytical mechanics, and invariant theory, and the results in this field were until now scattered across the literature. Thus the appearance of a book specifically devoted to projective duality is a long-awaited and welcome event. Projective Duality and Homogeneous Spaces covers a vast and diverse range of topics in the field of dual varieties, ranging from differential geometry to Mori theory and from topology to the theory of algebras. It gives a very readable and thorough account and the presentation of the material is clear and convincing. For the most part of the book the only prerequisites are basic algebra and algebraic geometry. This book will be of great interest to graduate and postgraduate students as well as professional mathematicians working in algebra, geometry and analysis.
A Null Space Approach for Solving Nonlinear Complementarity Problems
Institute of Scientific and Technical Information of China (English)
Pu-yan Nie
2006-01-01
In this work, null space techniques are employed to tackle nonlinear complementarity problems(NCPs). NCP conditions are transform into a nonlinear programming problem, which is handled by null space algorithms. The NCP conditions are divided into two groups. Some equalities and inequalities in an NCP are treated as constraints. While other equalities and inequalities in an NCP are to be regarded as objective function.Two groups are all updated in every step. Null space approaches are extended to nonlinear complementarity problems. Two different solvers are employed for an NCP in an algorithm.
Nonlinear regime-switching state-space (RSSS) models.
Chow, Sy-Miin; Zhang, Guangjian
2013-10-01
Nonlinear dynamic factor analysis models extend standard linear dynamic factor analysis models by allowing time series processes to be nonlinear at the latent level (e.g., involving interaction between two latent processes). In practice, it is often of interest to identify the phases--namely, latent "regimes" or classes--during which a system is characterized by distinctly different dynamics. We propose a new class of models, termed nonlinear regime-switching state-space (RSSS) models, which subsumes regime-switching nonlinear dynamic factor analysis models as a special case. In nonlinear RSSS models, the change processes within regimes, represented using a state-space model, are allowed to be nonlinear. An estimation procedure obtained by combining the extended Kalman filter and the Kim filter is proposed as a way to estimate nonlinear RSSS models. We illustrate the utility of nonlinear RSSS models by fitting a nonlinear dynamic factor analysis model with regime-specific cross-regression parameters to a set of experience sampling affect data. The parallels between nonlinear RSSS models and other well-known discrete change models in the literature are discussed briefly.
Nonlinear damped Schrodinger equation in two space dimensions
Directory of Open Access Journals (Sweden)
Tarek Saanouni
2015-04-01
Full Text Available In this article, we study the initial value problem for a semi-linear damped Schrodinger equation with exponential growth nonlinearity in two space dimensions. We show global well-posedness and exponential decay.
Space Compatible Radar Absorbing Materials Project
National Aeronautics and Space Administration — This SBIR Phase 1 project shall investigate novel radar absorbing materials (RAM) for use in space or simulated space environments. These materials are lightweight...
Singularity-free Bianchi spaces with nonlinear electrodynamics
García-Salcedo, R; Garcia-Salcedo, Ricardo; Breton, Nora
2004-01-01
In this paper we present the analysis to determine the existence of singularities in spatially homogeneous anisotropic universes filled with nonlinear electromagnetic radiation. These spaces are conformal to Bianchi spaces admitting a three parameter group of motions G$_3$. We study analytical extensions as well as geodesic completeness. It is shown that with nonlinear electromagnetic field some of the Bianchi spaces are geodesically complete, like G$_3$II and G$_3$VIII; however Bianchi G$_3$IX presents the phenomenon of geodesics that are imprisoned. In contrast, diagonal Bianchi spaces like G$_3$I, G$_3$III and Kantowski-Sachs have a finite time existence ending in a scalar polynomial curvature singularity.
Nonlinear Parabolic Equations with Singularities in Colombeau Vector Spaces
Institute of Scientific and Technical Information of China (English)
Mirjana STOJANOVI(C)
2006-01-01
We consider nonlinear parabolic equations with nonlinear non-Lipschitz's term and singular initial data like Dirac measure, its derivatives and powers. We prove existence-uniqueness theorems in Colombeau vector space gC1,w2,2([O,T),Rn),n ≤ 3. Due to high singularity in a case of parabolic equation with nonlinear conservative term we employ the regularized derivative for the conservative term, in order to obtain the global existence-uniqueness result in Colombeau vector space gC1,L2([O,T),Rn),n ≤ 3.
Nonlinear differentiation equation and analytic function spaces
Li, Hao; Li, Songxiao
2015-01-01
In this paper we consider the nonlinear complex differential equation $$(f^{(k)})^{n_{k}}+A_{k-1}(z)(f^{(k-1)})^{n_{k-1}}+\\cdot\\cdot\\cdot+A_{1}(z)(f')^{n_{1}}+A_{0}(z)f^{n_{0}}=0, $$where $ A_{j}(z)$, $ j=0, \\cdots, k-1 $, are analytic in the unit disk $ \\mathbb{D} $, $ n_{j}\\in R^{+} $ for all $ j=0, \\cdots, k $. We investigate this nonlinear differential equation from two aspects. On one hand, we provide some sufficient conditions on coefficients such that all solutions of this equation bel...
Space Qualified Heterogeneous Processing Project
National Aeronautics and Space Administration — Space Micro proposes to develop a radiation hardened, monolithic, heterogeneous processor for space imaging and radar systems. High performance processors are needed...
Nonlinear Adaptive Filter for MEMS Gyro Error Cancellation Project
National Aeronautics and Space Administration — The Nonlinear adaptive filters (NAF) can learn deterministic gyro errors and cancel the error’s effect from attitude estimates. By completely canceling...
Unified Nonlinear Flight Dynamics and Aeroelastic Simulator Tool Project
National Aeronautics and Space Administration — ZONA Technology, Inc. (ZONA) proposes a R&D effort to develop a Unified Nonlinear Flight Dynamics and Aeroelastic Simulator (UNFDAS) Tool that will combine...
Non-linear Ultrasonic Bond-Strength Monitor Project
National Aeronautics and Space Administration — To date, bond strength is considered one of the ?holy grails? for NDE. Preliminary data indicates that the Luna Nonlinear Ultrasonic Bond Strength (NUBS) monitor...
Geometric properties of Banach spaces and nonlinear iterations
Chidume, Charles
2009-01-01
Nonlinear functional analysis and applications is an area of study that has provided fascination for many mathematicians across the world. This monograph delves specifically into the topic of the geometric properties of Banach spaces and nonlinear iterations, a subject of extensive research over the past thirty years. Chapters 1 to 5 develop materials on convexity and smoothness of Banach spaces, associated moduli and connections with duality maps. Key results obtained are summarized at the end of each chapter for easy reference. Chapters 6 to 23 deal with an in-depth, comprehensive and up-to-date coverage of the main ideas, concepts and results on iterative algorithms for the approximation of fixed points of nonlinear nonexpansive and pseudo-contractive-type mappings. This includes detailed workings on solutions of variational inequality problems, solutions of Hammerstein integral equations, and common fixed points (and common zeros) of families of nonlinear mappings. Carefully referenced and full of recent,...
The nonlinear standing wave inside the space of liquid
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
Based on the basic equations of hydrodynamics, the nonlinear acoustic wave equation is obtained. By taking into account the boundary condition and properties of nonlinear standing wave, the equation is solved through perturbation method, and the stable expressions of fundamental wave and second harmonic are presented. The sound pressures in an ultrasonic cleaner are measured by hydrophones, and the relationship between the received voltages of hydrophones and the output voltages of the ultrasonic generator is researched. The study shows the existence of the nonlinear effect of liquid and analyzes the frequency spectrum of the received signals by hydrophones, by which the fundamental wave, second and high order harmonics are found coexisting in the bounded space filled with liquids. The theory and experimental results testify the existence of the nonlinear standing wave in liquid. Owing to the restricted applicability of perturbation method, the theoretical results of the fundamental wave and second harmonic are good only for the weak nonlinear phenomenon.
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...
Optical Space Telescope Assembly Project
National Aeronautics and Space Administration — The Optical Space Telescope Assembly (OSTA) task is to demonstrate the technology readiness of assembling large space telescopes on orbit in 2015. This task is an...
Nonlinear Mirror Modes in Space Plasmas
Sulem, P -L
2011-01-01
Since the first observations by Kaufmann et al.\\ (1970), special attention has been paid to static pressure-balanced structures in the form of magnetic holes or humps observed in regions of the solar wind and of planetary magnetosheaths where the $\\beta$ parameter is relatively large and the ion perpendicular temperature exceeds the parallel one. Although alternative interpretations have been proposed, these structures are usually viewed as associated with the mirror instability discovered in 1957 by Vedenov and Sagdeev. After reviewing observational results provided by satellite missions, high-resolution numerical simulations of the Vlasov--Maxwell equations together with asymptotic and phenomenological models of the nonlinear dynamics near the instability threshold are discussed. The constraining effect of the mirror instability on the temperature anisotropy associated with a dominant perpendicular ion heating observed in the solar wind is reported, and recent simulations of this phenomenon based on an elab...
Using Space as a Nonlinear Plasma Laboratory
Papadopoulos, Konstantinos
2008-11-01
Ionospheric heaters have been an important tool of plasma physics investigations. The extent that non-linear plasma phenomena can be triggered and observed depends critically on the heater power, its Effective Radiative Power (ERP) and its scanning capability. Increasing these parameters allows us to reach thresholds associated with effects that were not previously observed. The latest entry to ionospheric heating, the HF transmitter associated with the High Frequency Active Ionospheric Research Program (HAARP) was completed in June 2007. The transmitter consists of 180 antenna elements spanning 30.6 acres and can radiate 3.6 MW of HF power (a factor of almost 4 higher than any previous heater) in the 2.8-10.0 MHz range. With increasing frequency the beam-width varies from 15-5 degrees, corresponding to 20-30 dB gain and resulting in ERP between 1-5 GW. The antenna can point to any direction in a cone 30 degrees from the vertical, with reposition time of 15 microseconds resulting in superluminal scanning speeds. The transmitter can synthesize essentially any waveform and transmit any polarization. These capabilities far exceed those of any previous heater and allow for new frontier research in non-linear plasma physics. The presentation will focus first on the relationship of the new capabilities of the facility with thresholds of physical processes that had not been achieved previously. It will then present new spectacular results that have been achieved during the last year. They include whistler injection and amplification, injection of shear and magnetosonic waves in the magnetosphere, Langmuir turbulence, upper hybrid waves and thermal instabilities, electron acceleration, optical emissions and formation of artificial ducts for whistler propagation. The presentation will also discuss future experiments made possible for the first time by the new transmitter capabilities, large bandwidth and high ERP.
Relating harmonic and projective descriptions of N=2 nonlinear sigma models
Butter, Daniel
2012-01-01
Recent papers have established the relationship between projective superspace and a complexified version of harmonic superspace. We extend this construction to the case of general nonlinear sigma models in both frameworks. Using an analogy with Hamiltonian mechanics, we demonstrate how the Hamiltonian structure of the harmonic model and the symplectic structure of the projective model naturally arise from a single unifying action on a complexified version of harmonic superspace. This links the harmonic and projective descriptions of hyperkahler target spaces. For two examples, we show how to derive the projective superspace solutions for the Taub-NUT and Eguchi-Hanson models from the harmonic superspace solutions.
Nonlinear State Space Modeling and System Identification for Electrohydraulic Control
Directory of Open Access Journals (Sweden)
Jun Yan
2013-01-01
Full Text Available The paper deals with nonlinear modeling and identification of an electrohydraulic control system for improving its tracking performance. We build the nonlinear state space model for analyzing the highly nonlinear system and then develop a Hammerstein-Wiener (H-W model which consists of a static input nonlinear block with two-segment polynomial nonlinearities, a linear time-invariant dynamic block, and a static output nonlinear block with single polynomial nonlinearity to describe it. We simplify the H-W model into a linear-in-parameters structure by using the key term separation principle and then use a modified recursive least square method with iterative estimation of internal variables to identify all the unknown parameters simultaneously. It is found that the proposed H-W model approximates the actual system better than the independent Hammerstein, Wiener, and ARX models. The prediction error of the H-W model is about 13%, 54%, and 58% less than the Hammerstein, Wiener, and ARX models, respectively.
High Performance Space Pump Project
National Aeronautics and Space Administration — PDT is proposing a High Performance Space Pump based upon an innovative design using several technologies. The design will use a two-stage impeller, high temperature...
An analytic map for space charge in a nonlinear lattice
Energy Technology Data Exchange (ETDEWEB)
Benedetti, C. [Dipartimento di Fisica Universita di Bologna and INFN, Via Irnerio 46, 40126 Bologna (Italy)]. E-mail: benedetti@bo.infn.it; Turchetti, G. [Dipartimento di Fisica Universita di Bologna and INFN, Via Irnerio 46, 40126 Bologna (Italy)
2005-06-13
We propose a simple analytical model for an intense beam in a lattice with localized nonlinearities. In the thin lens limit a single nonlinearity leads to a Henon like map. When the space charge is present and the core radius is small with respect to the dynamic aperture, the use of a frozen core distribution like KV is justified. In this case we define an analytic map M by composing the phase advance due to space charge, computed at the first perturbation order, with the kick due to the nonlinear force. The corresponding dynamics is almost indistinguishable from the dynamics of the 'exact' map, which requires an accurate symplectic integration, if the tune depression is weak enough. The same accuracy is preserved for parametric modulations of the perveance or the beam core radius. The extension to any other distribution is straightforward.
Nonlinear Multigrid solver exploiting AMGe Coarse Spaces with Approximation Properties
DEFF Research Database (Denmark)
Christensen, Max la Cour; Villa, Umberto; Engsig-Karup, Allan Peter;
The paper introduces a nonlinear multigrid solver for mixed finite element discretizations based on the Full Approximation Scheme (FAS) and element-based Algebraic Multigrid (AMGe). The main motivation to use FAS for unstructured problems is the guaranteed approximation property of the AMGe coarse...... spaces that were developed recently at Lawrence Livermore National Laboratory. These give the ability to derive stable and accurate coarse nonlinear discretization problems. The previous attempts (including ones with the original AMGe method), were less successful due to lack of such good approximation...... are compared to FAS on a nonlinear saddle point problem with applications to porous media flow. It is demonstrated that FAS is faster than Newton’s method and Picard iterations for the experiments considered here. Due to the guaranteed approximation properties of our AMGe, the coarse spaces are very accurate...
Nonlinear Interferometry via Fock State Projection
Khoury, G; Eisenberg, H S; Fonseca, E J S
2006-01-01
We use a photon-number resolving detector to monitor the photon number distribution of the output of an interferometer, as a function of phase delay. As inputs we use coherent states with mean photon number up to seven. The postselection of a specific Fock (photon-number) state effectively induces high-order optical non-linearities. Following a scheme by Bentley and Boyd [S.J. Bentley and R.W. Boyd, Optics Express 12, 5735 (2004)] we explore this effect to demonstrate interference patterns a factor of five smaller than the Rayleigh limit.
Nonlinear Interferometry via Fock-State Projection
Khoury, G.; Eisenberg, H. S.; Fonseca, E. J. S.; Bouwmeester, D.
2006-05-01
We use a photon-number-resolving detector to monitor the photon-number distribution of the output of an interferometer, as a function of phase delay. As inputs we use coherent states with mean photon number up to seven. The postselection of a specific Fock (photon-number) state effectively induces high-order optical nonlinearities. Following a scheme by Bentley and Boyd [Opt. Express 12, 5735 (2004).OPEXFF1094-408710.1364/OPEX.12.005735], we explore this effect to demonstrate interference patterns a factor of 5 smaller than the Rayleigh limit.
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.
Directory of Open Access Journals (Sweden)
E. M. E. Zayed
2014-01-01
Full Text Available We apply the generalized projective Riccati equations method to find the exact traveling wave solutions of some nonlinear evolution equations with any-order nonlinear terms, namely, the nonlinear Pochhammer-Chree equation, the nonlinear Burgers equation and the generalized, nonlinear Zakharov-Kuznetsov equation. This method presents wider applicability for handling many other nonlinear evolution equations in mathematical physics.
Sarhadi, Ali; Burn, Donald H.; Johnson, Fiona; Mehrotra, Raj; Sharma, Ashish
2016-05-01
Accurate projection of global warming on the probabilistic behavior of hydro-climate variables is one of the main challenges in climate change impact assessment studies. Due to the complexity of climate-associated processes, different sources of uncertainty influence the projected behavior of hydro-climate variables in regression-based statistical downscaling procedures. The current study presents a comprehensive methodology to improve the predictive power of the procedure to provide improved projections. It does this by minimizing the uncertainty sources arising from the high-dimensionality of atmospheric predictors, the complex and nonlinear relationships between hydro-climate predictands and atmospheric predictors, as well as the biases that exist in climate model simulations. To address the impact of the high dimensional feature spaces, a supervised nonlinear dimensionality reduction algorithm is presented that is able to capture the nonlinear variability among projectors through extracting a sequence of principal components that have maximal dependency with the target hydro-climate variables. Two soft-computing nonlinear machine-learning methods, Support Vector Regression (SVR) and Relevance Vector Machine (RVM), are engaged to capture the nonlinear relationships between predictand and atmospheric predictors. To correct the spatial and temporal biases over multiple time scales in the GCM predictands, the Multivariate Recursive Nesting Bias Correction (MRNBC) approach is used. The results demonstrate that this combined approach significantly improves the downscaling procedure in terms of precipitation projection.
National Aeronautics and Space Administration — ZONA Technology proposes to develop an innovative nonlinear structural reduced order model (ROM) - nonlinear aerodynamic ROM methodology for the inflatable...
On space enrichment estimator for nonlinear Poisson-Boltzmann
Randrianarivony, Maharavo
2013-10-01
We consider the mathematical aspect of the nonlinear Poisson-Boltzmann equation which physically governs the ionic interaction between solute and solvent media. The presented a-posteriori estimates can be computed locally in a very efficient manner. The a-posteriori error is based upon hierarchical space enrichment which ensures its efficiency and reliability. A brief survey of the solving of the nonlinear system resulting from the FEM discretization is reported. To corroborate the analysis, we report on a few numerical results for illustrations. We numerically examine some values of the constants encountered in the theoretical study.
Implementing Kernel Methods Incrementally by Incremental Nonlinear Projection Trick.
Kwak, Nojun
2016-05-20
Recently, the nonlinear projection trick (NPT) was introduced enabling direct computation of coordinates of samples in a reproducing kernel Hilbert space. With NPT, any machine learning algorithm can be extended to a kernel version without relying on the so called kernel trick. However, NPT is inherently difficult to be implemented incrementally because an ever increasing kernel matrix should be treated as additional training samples are introduced. In this paper, an incremental version of the NPT (INPT) is proposed based on the observation that the centerization step in NPT is unnecessary. Because the proposed INPT does not change the coordinates of the old data, the coordinates obtained by INPT can directly be used in any incremental methods to implement a kernel version of the incremental methods. The effectiveness of the INPT is shown by applying it to implement incremental versions of kernel methods such as, kernel singular value decomposition, kernel principal component analysis, and kernel discriminant analysis which are utilized for problems of kernel matrix reconstruction, letter classification, and face image retrieval, respectively.
Projective synchronization of chaotic systems with bidirectional nonlinear coupling
Indian Academy of Sciences (India)
Mohammada Ali Khan; Swarup Poria
2013-09-01
This paper presents a new scheme for constructing bidirectional nonlinear coupled chaotic systems which synchronize projectively. Conditions necessary for projective synchronization (PS) of two bidirectionally coupled chaotic systems are derived using Lyapunov stability theory. The proposed PS scheme is discussed by taking as examples the so-called unified chaotic model, the Lorenz–Stenflo system and the nonautonomous chaotic Van der Pol oscillator. Numerical simulation results are presented to show the efficiency of the proposed synchronization scheme.
A nonlinear state-space approach to hysteresis identification
Noël, J. P.; Esfahani, A. F.; Kerschen, G.; Schoukens, J.
2017-02-01
Most studies tackling hysteresis identification in the technical literature follow white-box approaches, i.e. they rely on the assumption that measured data obey a specific hysteretic model. Such an assumption may be a hard requirement to handle in real applications, since hysteresis is a highly individualistic nonlinear behaviour. The present paper adopts a black-box approach based on nonlinear state-space models to identify hysteresis dynamics. This approach is shown to provide a general framework to hysteresis identification, featuring flexibility and parsimony of representation. Nonlinear model terms are constructed as a multivariate polynomial in the state variables, and parameter estimation is performed by minimising weighted least-squares cost functions. Technical issues, including the selection of the model order and the polynomial degree, are discussed, and model validation is achieved in both broadband and sine conditions. The study is carried out numerically by exploiting synthetic data generated via the Bouc-Wen equations.
Generalized non-linear strength theory and transformed stress space
Institute of Scientific and Technical Information of China (English)
YAO Yangping; LU Dechun; ZHOU Annan; ZOU Bo
2004-01-01
Based on the test data of frictional materials and previous research achievements in this field, a generalized non-linear strength theory (GNST) is proposed. It describes non-linear strength properties on the π-plane and the meridian plane using a unified formula, and it includes almost all the present non-linear strength theories, which can be used in just one material. The shape of failure function of the GNST is a smooth curve between the SMP criterion and the Mises criterion on the π-plane, and an exponential curve on the meridian plane. Through the transformed stress space based on the GNST, the combination of the GNST and various constitutive models using p and q as stress parameters can be realized simply and rationally in three-dimensional stress state.
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 $\\mathbb{S}^2$.
NONLINEAR MULTIGRID SOLVER EXPLOITING AMGe COARSE SPACES WITH APPROXIMATION PROPERTIES
Energy Technology Data Exchange (ETDEWEB)
Christensen, Max La Cour [Technical Univ. of Denmark, Lyngby (Denmark); Villa, Umberto E. [Univ. of Texas, Austin, TX (United States); Engsig-Karup, Allan P. [Technical Univ. of Denmark, Lyngby (Denmark); Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2016-01-22
The paper introduces a nonlinear multigrid solver for mixed nite element discretizations based on the Full Approximation Scheme (FAS) and element-based Algebraic Multigrid (AMGe). The main motivation to use FAS for unstruc- tured problems is the guaranteed approximation property of the AMGe coarse spaces that were developed recently at Lawrence Livermore National Laboratory. These give the ability to derive stable and accurate coarse nonlinear discretization problems. The previous attempts (including ones with the original AMGe method, [5, 11]), were less successful due to lack of such good approximation properties of the coarse spaces. With coarse spaces with approximation properties, our FAS approach on un- structured meshes should be as powerful/successful as FAS on geometrically re ned meshes. For comparison, Newton's method and Picard iterations with an inner state-of-the-art linear solver is compared to FAS on a nonlinear saddle point problem with applications to porous media ow. It is demonstrated that FAS is faster than Newton's method and Picard iterations for the experiments considered here. Due to the guaranteed approximation properties of our AMGe, the coarse spaces are very accurate, providing a solver with the potential for mesh-independent convergence on general unstructured meshes.
Discrete state space modeling and control of nonlinear unknown systems.
Savran, Aydogan
2013-11-01
A novel procedure for integrating neural networks (NNs) with conventional techniques is proposed to design industrial modeling and control systems for nonlinear unknown systems. In the proposed approach, a new recurrent NN with a special architecture is constructed to obtain discrete-time state-space representations of nonlinear dynamical systems. It is referred as the discrete state-space neural network (DSSNN). In the DSSNN, the outputs of the hidden layer neurons of the DSSNN represent the system's (pseudo) state. The inputs are fed to output neurons and the delayed outputs of the hidden layer neurons are fed to their inputs via adjustable weights. The discrete state space model of the actual system is directly obtained by training the DSSNN with the input-output data. A training procedure based on the back-propagation through time (BPTT) algorithm is developed. The Levenberg-Marquardt (LM) method with a trust region approach is used to update the DSSNN weights. Linear state space models enable to use well developed conventional analysis and design techniques. Thus, building a linear model of a system has primary importance in industrial applications. Thus, a suitable linearization procedure is proposed to derive the linear state space model from the nonlinear DSSNN representation. The controllability, observability and stability properties are examined. The state feedback controllers are designed with both the linear quadratic regulator (LQR) and the pole placement techniques. The regulator and servo control problems are both addressed. A full order observer is also designed to estimate the state variables. The performance of the proposed procedure is demonstrated by applying for both single-input single-output (SISO) and multiple-input multiple-output (MIMO) nonlinear control problems. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.
In-Space Robotic Servicing (ISRS) Project
National Aeronautics and Space Administration — This project advances the state of robotic technology to enable the routine servicing of satellites that were not designed with servicing in mind, including...
Geometrically Nonlinear Finite Element Analysis of a Composite Space Reflector
Lee, Kee-Joo; Leet, Sung W.; Clark, Greg; Broduer, Steve (Technical Monitor)
2001-01-01
Lightweight aerospace structures, such as low areal density composite space reflectors, are highly flexible and may undergo large deflection under applied loading, especially during the launch phase. Accordingly, geometrically nonlinear analysis that takes into account the effect of finite rotation may be needed to determine the deformed shape for a clearance check and the stress and strain state to ensure structural integrity. In this study, deformation of the space reflector is determined under static conditions using a geometrically nonlinear solid shell finite element model. For the solid shell element formulation, the kinematics of deformation is described by six variables that are purely vector components. Because rotational angles are not used, this approach is free of the limitations of small angle increments. This also allows easy connections between substructures and large load increments with respect to the conventional shell formulation using rotational parameters. Geometrically nonlinear analyses were carried out for three cases of static point loads applied at selected points. A chart shows results for a case when the load is applied at the center point of the reflector dish. The computed results capture the nonlinear behavior of the composite reflector as the applied load increases. Also, they are in good agreement with the data obtained by experiments.
Space vehicle pose estimation via optical correlation and nonlinear estimation
Rakoczy, John M.; Herren, Kenneth A.
2008-03-01
A technique for 6-degree-of-freedom (6DOF) pose estimation of space vehicles is being developed. This technique draws upon recent developments in implementing optical correlation measurements in a nonlinear estimator, which relates the optical correlation measurements to the pose states (orientation and position). For the optical correlator, the use of both conjugate filters and binary, phase-only filters in the design of synthetic discriminant function (SDF) filters is explored. A static neural network is trained a priori and used as the nonlinear estimator. New commercial animation and image rendering software is exploited to design the SDF filters and to generate a large filter set with which to train the neural network. The technique is applied to pose estimation for rendezvous and docking of free-flying spacecraft and to terrestrial surface mobility systems for NASA's Vision for Space Exploration. Quantitative pose estimation performance will be reported. Advantages and disadvantages of the implementation of this technique are discussed.
Information mining in weighted complex networks with nonlinear rating projection
Liao, Hao; Zeng, An; Zhou, Mingyang; Mao, Rui; Wang, Bing-Hong
2017-10-01
Weighted rating networks are commonly used by e-commerce providers nowadays. In order to generate an objective ranking of online items' quality according to users' ratings, many sophisticated algorithms have been proposed in the complex networks domain. In this paper, instead of proposing new algorithms we focus on a more fundamental problem: the nonlinear rating projection. The basic idea is that even though the rating values given by users are linearly separated, the real preference of users to items between the different given values is nonlinear. We thus design an approach to project the original ratings of users to more representative values. This approach can be regarded as a data pretreatment method. Simulation in both artificial and real networks shows that the performance of the ranking algorithms can be improved when the projected ratings are used.
National Aeronautics and Space Administration — ZONA proposes a phase II effort to fully develop a comprehensive methodology for aeroelastic predictions of the nonlinear aerodynamic/aerothermodynamic - structure...
Nonlinear Sigma Models with Compact Hyperbolic Target Spaces
Gubser, Steven; Schoenholz, Samuel S; Stoica, Bogdan; Stokes, James
2015-01-01
We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the $O(2)$ model. Unlike in the $O(2)$ case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. The diversity of compact hyperbolic manifolds suggest...
Principal Manifolds and Nonlinear Dimensionality Reduction via Tangent Space Alignment
Institute of Scientific and Technical Information of China (English)
张振跃; 查宏远
2004-01-01
We present a new algorithm for manifold learning and nonlinear dimensionality reduction. Based on a set of unorganized da-ta points sampled with noise from a parameterized manifold, the local geometry of the manifold is learned by constructing an approxi-mation for the tangent space at each point, and those tangent spaces are then aligned to give the global coordinates of the data pointswith respect to the underlying manifold. We also present an error analysis of our algorithm showing that reconstruction errors can bequite small in some cases. We illustrate our algorithm using curves and surfaces both in 2D/3D Euclidean spaces and higher dimension-al Euclidean spaces. We also address several theoretical and algorithmic issues for further research and improvements.
On nonlinear stability in various random normed spaces
Directory of Open Access Journals (Sweden)
Saadati Reza
2011-01-01
Full Text Available Abstract In this article, we prove the nonlinear stability of the quartic functional equation 1 6 f ( x + 4 y + f ( 4 x - y = 3 0 6 9 f x + y 3 + f ( x + 2 y (1 + 1 3 6 f ( x - y - 1 3 9 4 f ( x + y + 4 2 5 f ( y - 1 5 3 0 f ( x (2 (3 in the setting of random normed spaces Furthermore, the interdisciplinary relation among the theory of random spaces, the theory of non-Archimedean space, the theory of fixed point theory, the theory of intuitionistic spaces and the theory of functional equations are also presented in the article.
Introduction to Meridian Space Weather Monitoring Project
Institute of Scientific and Technical Information of China (English)
WU Ji; WANG Chi; FAN Quanlin
2006-01-01
The Meridian Project is a ground- based network program to monitor solar-terrestrial space environment, which consists of a chain of ground-based observatories with multiple instruments including magnetometers, ionosondes, HF and VHF radar, Lidar, IPS monitors, sounding rockets etc. The chain is mainly located in the neighborhood of 120°E meridian, and is thus named the Meridian Project. It has officially been approved by the Chinese government and will be finished by 2009. This talk will give an overview of the Meridian Project and the proposed International Space Weather Meridian Circle Program.
On time-space of nonlinear phenomena with Gompertzian dynamics.
Waliszewski, Przemyslaw; Konarski, Jerzy
2005-04-01
This paper describes a universal relationship between time and space for a nonlinear process with Gompertzian dynamics, such as growth. Gompertzian dynamics implicates a coupling between time and space. Those two categories are related to each other through a linear function of their logarithms. Moreover, we demonstrate that the spatial fractal dimension is a function of both scalar time and the temporal fractal dimension. The Gompertz function reflects the equilibrium of regular states, that is, states with dynamics that are predictable for any time-point (e.g., sinusoidal glycolytic oscillations) and chaotic states, that is, states with dynamics that are unpredictable in time, but are characterized by certain regularities (e.g., the existence of strange attractor for any biochemical reaction). We conclude that both this equilibrium and volume of the available complementary Euclidean space determine temporal and spatial expansion of a process with Gompertzian dynamics.
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.
Radiation Risk Projections for Space Travel
Cucinotta, Francis
2003-01-01
Space travelers are exposed to solar and galactic cosmic rays comprised of protons and heavy ions moving with velocities close to the speed of light. Cosmic ray heavy ions are known to produce more severe types of biomolecular damage in comparison to terrestrial forms of radiation, however the relationship between such damage and disease has not been fully elucidated. On Earth, we are protected from cosmic rays by atmospheric and magnetic shielding, and only the remnants of cosmic rays in the form of ground level muons and other secondary radiations are present. Because human epidemiology data is lacking for cosmic rays, risk projection must rely on theoretical understanding and data from experimental models exposed to space radiation using charged particle accelerators to simulate space radiation. Although the risks of cancer and other late effects from cosmic rays are currently believed to present a severe challenge to space travel, this challenge is centered on our lack of confidence in risk projections methodologies. We review biophysics and radiobiology data on the effects of the cosmic ray heavy ions, and the current methods used to project radiation risks . Cancer risk projections are described as a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Risk projections for space travel are described using Monte-Carlo sampling from subjective error di stributions that represent the lack of knowledge in each factor that contributes to the projection model in order to quantify the overall uncertainty in risk projections. This analysis is applied to space mi ssion scenarios including lunar colony, deep space outpost, and a Mars mission. Results suggest that the number of days in space where cancer mortality risks can be assured at a 95% confidence level to be below the maximum acceptable risk for radi ation workers on Earth or the International Space Station is only on the order
Nonlinear rotordynamics analysis. [Space Shuttle Main Engine turbopumps
Noah, Sherif T.
1991-01-01
Effective analysis tools were developed for predicting the nonlinear rotordynamic behavior of the Space Shuttle Main Engine (SSME) turbopumps under steady and transient operating conditions. Using these methods, preliminary parametric studies were conducted on both generic and actual HPOTP (high pressure oxygen turbopump) models. In particular, a novel modified harmonic balance/alternating Fourier transform (HB/AFT) method was developed and used to conduct a preliminary study of the effects of fluid, bearing and seal forces on the unbalanced response of a multi-disk rotor in the presence of bearing clearances. The method makes it possible to determine periodic, sub-, super-synchronous and chaotic responses of a rotor system. The method also yields information about the stability of the obtained response, thus allowing bifurcation analyses. This provides a more effective capability for predicting the response under transient conditions by searching in proximity of resonance peaks. Preliminary results were also obtained for the nonlinear transient response of an actual HPOTP model using an efficient, newly developed numerical method based on convolution integration. Currently, the HB/AFT is being extended for determining the aperiodic response of nonlinear systems. Initial results show the method to be promising.
EXTENSION OF THE PROJECTION THEOREM ON HILBERT SPACE TO FUZZY HILBERT SPACE OVER FUZZY NUMBER SPACE
K. P. DEEPA; Dr.S.Chenthur Pandian
2012-01-01
In this paper, we extend the projection theorem on Hilbert space to its fuzzy version over fuzzy number space embedded with fuzzy number mapping. To prove this we discuss the concepts of fuzzy Hilbert space over fuzzy number space with fuzzy number mapping. The fuzzy orthogonality, fuzzy orthonormality, fuzzy complemented subset property etc. of fuzzy Hilbert space over fuzzy number space using fuzzy number mapping also been discussed.
Estimation methods for nonlinear state-space models in ecology
DEFF Research Database (Denmark)
Pedersen, Martin Wæver; Berg, Casper Willestofte; Thygesen, Uffe Høgsbro
2011-01-01
The use of nonlinear state-space models for analyzing ecological systems is increasing. A wide range of estimation methods for such models are available to ecologists, however it is not always clear, which is the appropriate method to choose. To this end, three approaches to estimation in the theta...... logistic model for population dynamics were benchmarked by Wang (2007). Similarly, we examine and compare the estimation performance of three alternative methods using simulated data. The first approach is to partition the state-space into a finite number of states and formulate the problem as a hidden...... Markov model (HMM). The second method uses the mixed effects modeling and fast numerical integration framework of the AD Model Builder (ADMB) open-source software. The third alternative is to use the popular Bayesian framework of BUGS. The study showed that state and parameter estimation performance...
Space Science Projects. LC Science Tracer Bullet.
Carter, Constance, Comp.; Howland, Joyce, Comp.
This document presents sources to assist elementary and secondary school students and teachers in planning, preparing, and executing projects in the space sciences. Bibliographies for the following sections are included: (1) Basic Texts, (2) Specialized Texts, (3) Classroom Experiments and Activities, (4) Background Readings, (5) Related Titles,…
OBLIQUE PROJECTION REALIZATION OF A KERNEL-BASED NONLINEAR DISCRIMINATOR
Institute of Scientific and Technical Information of China (English)
Liu Benyong; Zhang Jing
2006-01-01
Previously, a novel classifier called Kernel-based Nonlinear Discriminator (KND) was proposed to discriminate a pattern class from other classes by minimizing mean effect of the latter. To consider the effect of the target class, this paper introduces an oblique projection algorithm to determine the coefficients of a KND so that it is extended to a new version called extended KND (eKND). In eKND construction, the desired output vector of the target class is obliquely projected onto the relevant subspace along the subspace related to other classes. In addition, a simple technique is proposed to calculate the associated oblique projection operator. Experimental results on handwritten digit recognition show that the algorithm performes better than a KND classifier and some other commonly used classifiers.
New cooperative projection neural network for nonlinearly constrained variational inequality
Institute of Scientific and Technical Information of China (English)
XIA YouSheng
2009-01-01
This paper proposes a new cooperative projection neural network (CPNN), which combines automat-ically three individual neural network models with a common projection term. As a special case, the proposed CPNN can include three recent recurrent neural networks for solving monotone variational in-equality problems with limit or linear constraints, respectively. Under the monotonicity condition of the corresponding Lagrangian mapping, the proposed CPNN is theoretically guaranteed to solve monotone variational inequality problems and a class of nonmonotone variational inequality problems with linear and nonlinear constraints. Unlike the extended projection neural network, the proposed CPNN has no limitation on the initial point for global convergence. Compared with other related cooperative neural networks and numerical optimization algorithms, the proposed CPNN has a low computational complex-ity and requires weak convergence conditions. An application in real-time grasping force optimization and examples demonstrate good performance of the proposed CPNN.
Sparse Nonlinear Electromagnetic Imaging Accelerated With Projected Steepest Descent Algorithm
Desmal, Abdulla
2017-04-03
An efficient electromagnetic inversion scheme for imaging sparse 3-D domains is proposed. The scheme achieves its efficiency and accuracy by integrating two concepts. First, the nonlinear optimization problem is constrained using L₀ or L₁-norm of the solution as the penalty term to alleviate the ill-posedness of the inverse problem. The resulting Tikhonov minimization problem is solved using nonlinear Landweber iterations (NLW). Second, the efficiency of the NLW is significantly increased using a steepest descent algorithm. The algorithm uses a projection operator to enforce the sparsity constraint by thresholding the solution at every iteration. Thresholding level and iteration step are selected carefully to increase the efficiency without sacrificing the convergence of the algorithm. Numerical results demonstrate the efficiency and accuracy of the proposed imaging scheme in reconstructing sparse 3-D dielectric profiles.
Nonlinear sigma models with compact hyperbolic target spaces
Gubser, Steven; Saleem, Zain H.; Schoenholz, Samuel S.; Stoica, Bogdan; Stokes, James
2016-06-01
We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the O(2) model [1, 2]. Unlike in the O(2) case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. The diversity of compact hyperbolic manifolds suggests that our model is only the simplest example of a broad class of statistical mechanical models whose main features can be understood essentially in geometric terms.
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.
Nonlinear Aerodynamics-Structure Time Simulation for HALE Aircraft Design/Analysis Project
National Aeronautics and Space Administration — Time simulation of a nonlinear aerodynamics model (NA) developed at Virginia Tech coupled with a nonlinear structure model (NS) is proposed as a design/analysis...
Real Hypersurfaces of a Complex Projective Space
Indian Academy of Sciences (India)
Sharief Deshmukh
2011-05-01
In this paper, we classify real hypersurfaces in the complex projective space $CP\\frac{n+1}{2}$ whose structure vector field is a -analytic vector field (a notion similar to analytic vector fields on complex manifolds). We also define Jacobi-type vector fields on a Riemannian manifold and classify real hypersurfaces whose structure vector field is a Jacobi-type vector field.
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.
Projective Loop Quantum Gravity I. State Space
Lanéry, Suzanne
2014-01-01
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 [Oko{\\l}\\'ow 2013, arXiv:1304.6330] 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, wh...
Nonlinear projection trick in kernel methods: an alternative to the kernel trick.
Kwak, Nojun
2013-12-01
In kernel methods such as kernel principal component analysis (PCA) and support vector machines, the so called kernel trick is used to avoid direct calculations in a high (virtually infinite) dimensional kernel space. In this brief, based on the fact that the effective dimensionality of a kernel space is less than the number of training samples, we propose an alternative to the kernel trick that explicitly maps the input data into a reduced dimensional kernel space. This is easily obtained by the eigenvalue decomposition of the kernel matrix. The proposed method is named as the nonlinear projection trick in contrast to the kernel trick. With this technique, the applicability of the kernel methods is widened to arbitrary algorithms that do not use the dot product. The equivalence between the kernel trick and the nonlinear projection trick is shown for several conventional kernel methods. In addition, we extend PCA-L1, which uses L1-norm instead of L2-norm (or dot product), into a kernel version and show the effectiveness of the proposed approach.
Space project IONOSAT- MICRO - goals and realization
Korepanov, Valery; Lizunov, Georgii; Fedorov, Oleg
2013-04-01
The IONOSAT-MICRO project is a first stage of IONOSAT program devoted to the multi-point global monitoring of dynamic processes in the ionosphere. The IONOSAT program is planned to be realized in 2015-2020 with the help of three satellites at coordinated low Earth orbits (LEO). IONOSAT-MICRO is the forerunner project scheduled for launch in 2014 at sun-synchronous orbit with the aim to test the IONOSAT mission scientific postulates and preliminary collection of related space data. The main goal of the IONOSAT-MICRO project is the systematic study of the dynamic response of the ionosphere to the influence "from above" (sun, geomagnetic activity) and "from below" (powerful meteorological, seismic and anthropogenic impacts). More in details, the study of following formations in the ionosphere is foreseen: - Space-temporal structure and global distribution of inhomogeneities in neutral atmosphere and ionosphere; - Global structure and dynamics of quasi-stationary electric currents, electric and magnetic fields; - Wave structures and turbulences at different spatial and temporal scales. To realize such a research, the scientific payload of the MICROSAT spacecraft will provide the measurements of following parameters: - Neutral gas and plasma parameters - concentration, temperature; - DC-ELF-VLF electromagnetic field vectors and ELF-VLF plasma current fluctuations; - Total electron content (TEC); - Spectral content of plasma oscillations. Synchronous experiments with ground support facilities - both active and passive ones - are also foreseen. The IONOSAT-MICRO project will be realized onboard of MICROSAT microsatellite platform, manufactured by Yuzhnoye Design Office with new experimental models of ammonia propulsion system, battery, solar arrays and panels with thermal control coating, the in-flight tests of which are also planned in frames of the project. The composition of the scientific equipment developed by the international team of participants and sensors
Directory of Open Access Journals (Sweden)
W. Dzwinel
2005-01-01
Full Text Available We present a novel technique based on a multi-resolutional clustering and nonlinear multi-dimensional scaling of earthquake patterns to investigate observed and synthetic seismic catalogs. The observed data represent seismic activities around the Japanese islands during 1997-2003. The synthetic data were generated by numerical simulations for various cases of a heterogeneous fault governed by 3-D elastic dislocation and power-law creep. At the highest resolution, we analyze the local cluster structures in the data space of seismic events for the two types of catalogs by using an agglomerative clustering algorithm. We demonstrate that small magnitude events produce local spatio-temporal patches delineating neighboring large events. Seismic events, quantized in space and time, generate the multi-dimensional feature space characterized by the earthquake parameters. Using a non-hierarchical clustering algorithm and nonlinear multi-dimensional scaling, we explore the multitudinous earthquakes by real-time 3-D visualization and inspection of the multivariate clusters. At the spatial resolutions characteristic of the earthquake parameters, all of the ongoing seismicity both before and after the largest events accumulates to a global structure consisting of a few separate clusters in the feature space. We show that by combining the results of clustering in both low and high resolution spaces, we can recognize precursory events more precisely and unravel vital information that cannot be discerned at a single resolution.
Nonlinear sigma models with compact hyperbolic target spaces
Energy Technology Data Exchange (ETDEWEB)
Gubser, Steven [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Saleem, Zain H. [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104 (United States); National Center for Physics, Quaid-e-Azam University Campus,Islamabad 4400 (Pakistan); Schoenholz, Samuel S. [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104 (United States); Stoica, Bogdan [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Stokes, James [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104 (United States)
2016-06-23
We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the O(2) model V.L. Berezinskii, Destruction of long-range order in one-dimensional and two-dimensional systems having a continuous symmetry group II. Quantum systems, Sov. Phys. JETP 34 (1972) 610. J.M. Kosterlitz and D.J. Thouless, Ordering, metastability and phase transitions in two-dimensional systems, J. Phys. C 6 (1973) 1181 [http://inspirehep.net/search?p=find+J+%22J.Phys.,C6,1181%22]. . Unlike in the O(2) case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. The diversity of compact hyperbolic manifolds suggests that our model is only the simplest example of a broad class of statistical mechanical models whose main features can be understood essentially in geometric terms.
Identification of a Class of Non-linear State Space Models using RPE Techniques
DEFF Research Database (Denmark)
Zhou, Wei-Wu; Blanke, Mogens
1989-01-01
The RPE (recursive prediction error) method in state-space form is developed in the nonlinear systems and extended to include the exact form of a nonlinearity, thus enabling structure preservation for certain classes of nonlinear systems. Both the discrete and the continuous-discrete versions...... of the algorithm in an innovations model are investigated, and a nonlinear simulation example shows a quite convincing performance of the filter as combined parameter and state estimator...
Flight Dynamic Simulation with Nonlinear Aeroelastic Interaction using the ROM-ROM Procedure Project
National Aeronautics and Space Administration — ZONA Technology, Inc. (ZONA) proposes to develop an integrated flight dynamics simulation capability with nonlinear aeroelastic interactions by combining a flight...
Flight Dynamic Simulation with Nonlinear Aeroelastic Interaction using the ROM-ROM Procedure Project
National Aeronautics and Space Administration — ZONA Technology, Inc. proposes to develop an integrated flight dynamics simulation capability with nonlinear aeroelastic interactions by combining a flight dynamics...
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.
Miniature Space Dosimeter Based on Semiconductor Oxides Project
National Aeronautics and Space Administration — Space Micro and Clemson University have teamed for a miniature, ultra low power, space radiation dosimeter. We project this unit, "MicroRad", to be 50X...
Nonlinear Landau-Zener tunneling in quantum phase space
Energy Technology Data Exchange (ETDEWEB)
Trimborn, F [Institut fuer theoretische Physik, Leibniz Universitaet Hannover, D-30167 Hannover (Germany); Witthaut, D [QUANTOP, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Kegel, V; Korsch, H J, E-mail: friederike.trimborn@itp.uni-hannover.d [Fachbereich Physik, TU Kaiserslautern, D-67663 Kaiserslautern (Germany)
2010-05-15
We present a detailed analysis of the Landau-Zener problem for an interacting Bose-Einstein condensate in a time-varying double-well trap, especially focusing on the relation between the full many-particle problem and the mean-field approximation. Due to the nonlinear self-interaction a dynamical instability occurs, which leads to a breakdown of adiabaticity and thus fundamentally alters the dynamics. It is shown that essentially all the features of the Landau-Zener problem including the depletion of the condensate mode can be already understood within a semiclassical phase-space picture. In particular, this treatment resolves the formerly imputed incommutability of the adiabatic and semiclassical limits. The possibility of exploiting Landau-Zener sweeps to generate squeezed states for spectroscopic tasks is analyzed in detail. Moreover, we study the influence of phase noise and propose a Landau-Zener sweep as a sensitive yet readily implementable probe for decoherence, since the noise has significant effect on the transition rate for slow parameter variations.
Nonlinear Landau-Zener tunneling in quantum phase space
Trimborn, F; Kegel, V; Korsch, H J; 10.1088/1367-2630/12/5/053010
2010-01-01
We present a detailed analysis of the Landau-Zener problem for an interacting Bose-Einstein condensate in a time-varying double-well trap, especially focussing on the relation between the full many-particle problem and the mean-field approximation. Due to the nonlinear self-interaction a dynamical instability occurs, which leads to a breakdown of adiabaticity condition and thus fundamentally alters the dynamics. It is shown that essentially all features of the Landau-Zener problem including the depletion of the condensate mode can be already understood within a semiclassical phase space picture. In particular, this treatment resolves the formerly imputed incommutability of the adiabatic and semiclassical limits. The possibility to exploit Landau-Zener sweeps to generate squeezed states for spectroscopic tasks is analysed in detail. Moreover, we study the influence of phase noise and propose a Landau-Zener sweep as a sensitive, yet readily implementable probe for decoherence, since this has a significant effec...
Identification of a class of nonlinear state-space models using RPE techniques
DEFF Research Database (Denmark)
Zhou, W. W.; Blanke, Mogens
1986-01-01
The recursive prediction error methods in state-space form have been efficiently used as parameter identifiers for linear systems, and especially Ljung's innovations filter using a Newton search direction has proved to be quite ideal. In this paper, the RPE method in state-space form is developed...... to the nonlinear case and extended to include the exact form of a nonlinearity, thus enabling structure preservation for certain classes of nonlinear systems. Both the discrete and the continuous-discrete versions of the algorithm in an innovations model are investigated, and a nonlinear simulation example shows...... a quite convincing performance of the filter as combined parameter and state estimator....
Autonomous Deep-Space Optical Navigation Project
D'Souza, Christopher
2014-01-01
This project will advance the Autonomous Deep-space navigation capability applied to Autonomous Rendezvous and Docking (AR&D) Guidance, Navigation and Control (GNC) system by testing it on hardware, particularly in a flight processor, with a goal of limited testing in the Integrated Power, Avionics and Software (IPAS) with the ARCM (Asteroid Retrieval Crewed Mission) DRO (Distant Retrograde Orbit) Autonomous Rendezvous and Docking (AR&D) scenario. The technology, which will be harnessed, is called 'optical flow', also known as 'visual odometry'. It is being matured in the automotive and SLAM (Simultaneous Localization and Mapping) applications but has yet to be applied to spacecraft navigation. In light of the tremendous potential of this technique, we believe that NASA needs to design a optical navigation architecture that will use this technique. It is flexible enough to be applicable to navigating around planetary bodies, such as asteroids.
Analytical approximate solution for nonlinear space-time fractional Klein-Gordon equation
Institute of Scientific and Technical Information of China (English)
Khaled A.Gepreel; Mohamed S.Mohamed
2013-01-01
The fractional derivatives in the sense of Caputo and the homotopy analysis method are used to construct an approximate solution for the nonlinear space-time fractional derivatives Klein-Gordon equation.The numerical results show that the approaches are easy to implement and accurate when applied to the nonlinear space-time fractional derivatives KleinGordon equation.This method introduces a promising tool for solving many space-time fractional partial differential equations.This method is efficient and powerful in solving wide classes of nonlinear evolution fractional order equations.
On projective invariants of the complex Finsler spaces
Aldea, Nicoleta
2011-01-01
In this paper the projective curvature invariants of a complex Finsler space are obtained. By means of these invariants the notion of complex Douglas space is then defined. A special approach is devoted to obtain the equivalence conditions that a complex Finsler space should be Douglas. It is shown that any weakly K\\"{a}hler Douglas space is a complex Berwald space. A projective curvature invariant of Weyl type characterizes the complex Berwald spaces. They must be either purely Hermitian of constant holomorphic curvature or non purely Hermitian of vanish holomorphic curvature. The locally projectively flat complex Finsler metrics are also studied
A dual approach in Orlicz spaces for the nonlinear Helmholtz equation
Evéquoz, Gilles
2015-12-01
In this paper, we present a variational framework in Orlicz spaces for the study of the nonlinear Helmholtz equation - Δ{u} - k2 u = f(x,u),quad {x} in {R}^N where N ≥ 3, k > 0 and f is a superlinear but subcritical nonlinearity, and we prove the existence of infinitely many real-valued solutions under additional decay assumptions on the nonlinear term. We also derive a far-field relation for these solutions.
Energy Technology Data Exchange (ETDEWEB)
Belmonte-Beitia, Juan [Departamento de Matematicas, E.T.S. de Ingenieros Industriales and Instituto de Matematica Aplicada a la Ciencia y la Ingenieria (IMACI), Avda. Camilo Jose Cela 3, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)], E-mail: juan.belmonte@uclm.es; Calvo, Gabriel F. [Departamento de Matematicas, E.T.S. de Ingenieros Industriales and Instituto de Matematica Aplicada a la Ciencia y la Ingenieria (IMACI), Avda. Camilo Jose Cela 3, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)], E-mail: gabriel.fernandez@uclm.es
2009-01-19
In this Letter, by means of similarity transformations, we construct explicit solutions to the quintic nonlinear Schroedinger equation with potentials and nonlinearities depending both on time and on the spatial coordinates. We present the general approach and use it to study some examples and find nontrivial explicit solutions such as periodic (breathers), quasiperiodic and bright and dark soliton solutions.
Locally Bounded Function Spaces as the External Environment for Nonlinear Systems
Directory of Open Access Journals (Sweden)
Valery G. Fetisov
2013-01-01
Full Text Available . In this paper we consider locally bounded function spaces that act as the external environment for nonlinear dynamic systems. We give non-traditional examples of above spaces in which the basis of the selected function Orlicz space
Identification of Nonlinear Nonautonomous State Space Systems from Input-Output Measurements
Verdult, Vincent; Verhaegen, Michel; Scherpen, Jacquelien
2000-01-01
This paper presents a method to determine a nonlinear state space model from a finite number of measurements of the inputs and outputs. The method is based on embedding theory for nonlinear systems, and can be viewed as an extension of the subspace identification method for linear systems. The paper
Institute of Scientific and Technical Information of China (English)
Wan-sheng WANG; Shou-fu LI; Run-sheng YANG
2012-01-01
A series of contractivity and exponential stability results for the solutions to nonlinear neutral functional differential equations (NFDEs) in Banach spaces are obtained,which provide unified theoretical foundation for the contractivity analysis of solutions to nonlinear problems in functional differential equations (FDEs),neutral delay differential equations (NDDEs) and NFDEs of other types which appear in practice.
NONLOCAL INITIAL PROBLEM FOR NONLINEAR NONAUTONOMOUS DIFFERENTIAL EQUATIONS IN A BANACH SPACE
Institute of Scientific and Technical Information of China (English)
M.I.Gil＇
2004-01-01
The nonlocal initial problem for nonlinear nonautonomous evolution equations in a Banach space is considered. It is assumed that the nonlinearities have the local Lipschitz properties. The existence and uniqueness of mild solutions are proved. Applications to integro-differential equations are discussed. The main tool in the paper is the normalizing mapping (the generalized norm).
Tam, Leo K; Stockmann, Jason P; Galiana, Gigi; Constable, R Todd
2012-10-01
To increase image acquisition efficiency, we develop alternative gradient encoding strategies designed to provide spatial encoding complementary to the spatial encoding provided by the multiple receiver coil elements in parallel image acquisitions. Intuitively, complementary encoding is achieved when the magnetic field encoding gradients are designed to encode spatial information where receiver spatial encoding is ambiguous, for example, along sensitivity isocontours. Specifically, the method generates a basis set for the null space of the coil sensitivities with the singular value decomposition and calculates encoding fields from the null space vectors. A set of nonlinear gradients is used as projection imaging readout magnetic fields, replacing the conventional linear readout field and phase encoding. Multiple encoding fields are used as projections to capture the null space information, hence the term null space imaging. The method is compared to conventional Cartesian SENSitivity Encoding as evaluated by mean squared error and robustness to noise. Strategies for developments in the area of nonlinear encoding schemes are discussed. The null space imaging approach yields a parallel imaging method that provides high acceleration factors with a limited number of receiver coil array elements through increased time efficiency in spatial encoding.
Titanium Loop Heat Pipes for Space Nuclear Radiators Project
National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will develop titanium Loop Heat Pipes (LHPs) that can be used in low-mass space nuclear radiators, such as...
Advanced Space Power Systems (ASPS): Regenerative Fuel Cells (RFC) Project
National Aeronautics and Space Administration — The objective of the regenerative fuel cell project element is to develop power and energy storage technologies that enable new capabilities for future human space...
Modular Architecture for the Deep Space Habitat Instrumentation System Project
National Aeronautics and Space Administration — This project is focused on developing a continually evolving modular backbone architecture for the Deep Space Habitat (DSH) instrumentation system by integrating new...
Multicore Rad Hard Processing in Space Project
National Aeronautics and Space Administration — Space Micro proposes to research and develop a high performance computing/processing platform for NASA space missions. Leveraging our previous work for both NASA and...
Miniature Active Space Radiation Dosimeter Project
National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...
Space-Qualifiable Cyanate Ester Elastomer Project
National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG) proposes to design and develop a space-qualifiable cyanate ester elastomer for application in self-deployable space structures...
Securing Data for Space Communications Project
National Aeronautics and Space Administration — NASA's vision of data exchange between space and ground nodes would involve the space network accessing public infrastructure such as the internet. Hence, advanced...
Lightweight Radiator Fins for Space Nuclear Power Project
National Aeronautics and Space Administration — This SBIR Phase 1 project shall investigate concept radiator fins that incorporate novel carbon materials for improved performance of segmented high temperature...
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, ma...
Electronic Health Monitoring for Space Systems Project
National Aeronautics and Space Administration — Prognostic monitoring capabilities for space exploration aircrafts are crucial to enable safety and reliability in these platforms. Nokomis proposes to develop and...
Live From Space Station Outreach Payload Project
National Aeronautics and Space Administration — The Live from Space Station? Outreach Payload (LFSSOP) is a technologically challenging, exciting opportunity for university students to conduct significant research...
Improved Ionic Liquids as Space Lubricants Project
National Aeronautics and Space Administration — Ionic liquids are candidate lubricant materials. However for application in low temperature space mechanisms their lubrication performance needs to be enhanced. UES...
Seljak, Uros
2012-01-01
On large scales a nonlinear transformation of matter density field can be viewed as a biased tracer of the density field itself. A nonlinear transformation also modifies the redshift space distortions in the same limit, giving rise to a velocity bias. In models with primordial nongaussianity a nonlinear transformation generates a scale dependent bias on large scales. We derive analytic expressions for these for a general nonlinear transformation. These biases can be expressed entirely in terms of the one point distribution function (PDF) of the final field and the parameters of the transformation. Our analysis allows one to devise nonlinear transformations with nearly arbitrary bias properties, which can be used to increase the signal in the large scale clustering limit. We apply the results to the ionizing equilibrium model of Lyman-alpha forest, in which Lyman-alpha flux F is related to the density perturbation delta via a nonlinear transformation. Velocity bias can be expressed as an average over the Lyman...
Exact solutions of SO(3) non-linear sigma model in a conic space background
Bezerra, V B; Romero, C
2005-01-01
We consider a nonlinear sigma model coupled to the metric of a conic space. We obtain restrictions for a nonlinear sigma model to be a source of the conic space. We then study nonlinear sigma model in the conic space background. We find coordinate transformations which reduce the chiral fields equations in the conic space background to field equations in Minkowski spacetime. This enables us to apply the same methods for obtaining exact solutions in Minkowski spacetime to the case of a conic spacetime. In the case the solutions depend on two spatial coordinates we employ Ivanov's geometrical ansatz. We give a general analysis and also present classes of solutions in which there is dependence on three and four coordinates. We discuss with special attention the intermediate instanton and meron solutions and their analogous in the conic space. We find differences in the total actions and topological charges of these solutions and discuss the role of the deficit angle.
Hua, Minh-Duc; Hamel, Tarek; Mahony, Robert; Trumpf, Jochen
2015-01-01
A nonlinear observer on the Special Euclidean group $\\mathrm{SE(3)}$ for full pose estimation, that takes the system outputs on the real projective space directly as inputs, is proposed. The observer derivation is based on a recent advanced theory on nonlinear observer design. A key advantage with respect to existing pose observers on $\\mathrm{SE(3)}$ is that we can now incorporate in a unique observer different types of measurements such as vectorial measurements of known inertial vectors an...
Difference schemes for fully nonlinear pseudo-parabolic systems with two space dimensions
Institute of Scientific and Technical Information of China (English)
周毓麟; 袁光伟
1996-01-01
The first boundary value problem for the fully nonlinear pseudoparabolic systems of partial differential equations with two space dimensions by the finite difference method is studied. The existence and uniqueness of the discrete vector solutions for the difference systems are established by the fixed point technique. The stability and convergence of the discrete vector solutions of the difference schemes to the vector solutions of the original boundary problem of the fully nonlinear pseudo-parabolic system are obtained by way of a priori estimation. Here the unique smooth vector solution of the original problems for the fully nonlinear pseudo-parabolic system is assumed. Moreover, by the method used here, it can be proved that analogous results hold for fully nonlinear pseudo-parabolic system with three space dimensions, and improve the known results in the case of one space dimension.
On a state space approach to nonlinear H∞ control
Schaft, van der A.J.
1991-01-01
We study the standard H∞ optimal control problem using state feedback for smooth nonlinear control systems. The main theorem obtained roughly states that the L2-induced norm (from disturbances to inputs and outputs) can be made smaller than a constant γ > 0 if the corresponding H∞ norm for the syste
Novel Reduced Order in Time Models for Problems in Nonlinear Aeroelasticity Project
National Aeronautics and Space Administration — Research is proposed for the development and implementation of state of the art, reduced order models for problems in nonlinear aeroelasticity. Highly efficient and...
Self-Assembly of Nanocomposite Nonlinear Optical Materials for Photonic Devices Project
National Aeronautics and Space Administration — This program targets the development of new highly anisotropic nonlinear optical nanocomposite materials for NASA and non-NASA applications in advanced photonic and...
Handheld Nonlinear Detection of Delamination and Intrusion Faults in Composites Project
National Aeronautics and Space Administration — In Phase I of the SBIR program, LEEOAT Company will develop a hand-held high-resolution ultrasonic nonlinear imager for non-destructive inspection (NDI) of...
Institute of Scientific and Technical Information of China (English)
GAO Jie
2009-01-01
In this paper we treat first some nonlinear beam dynamics problems in storage rings, such as beam dynamic apertures due to magnetic multipoles, wiggles, beam-beam effects, nonlinear space charge effect, and then nonlinear electron cloud effect combined with beam-beam and space charge effects, analytically. This analytical treatment is applied to BEPC Ⅱ. The corresponding analytical expressions developed in this paper are useful both in understanding the physics behind these problems and also in making practical quick hand estimations.
Microwave Materials Processing for Space Applications Project
National Aeronautics and Space Administration — For a space-based fabrication effort to be effective, the weight, power requirements and footprint must be minimized. Because of the unique beam forming properties...
High Performance Bipropellant Space Engines Project
National Aeronautics and Space Administration — Advanced bipropellant engines are needed for ARES/ORION vehicle maneuvering and future deep space science missions. Currently, an iridium-lined rhenium combustion...
Advanced Fire Detector for Space Applications Project
National Aeronautics and Space Administration — New sensor technology is required to face the challenging tasks associated with future space exploration involving missions to the Moon and Mars. The safety and...
3D Flash LIDAR Space Laser Project
National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business that has developed 3D Flash LIDAR systems for space and terrestrial applications. 3D Flash LIDAR is...
Shielded ADR Magnets For Space Applications Project
National Aeronautics and Space Administration — The Phase II program will concentrate on manufacturing of qualified low-current, light-weight, 10K ADR magnets for space application. Shielded ADR solenoidal magnets...
Deep Space Optical Communication (DSOC) Project
National Aeronautics and Space Administration — Develop key technologies that enable operational deep space optical communications.Spacecraft disturbance isolation platform for sub-microradian pointing with...
SWaP Optimized Space Transceivers Project
National Aeronautics and Space Administration — Size and weight of payloads on space platforms is limited by the launch vehicle capacity, and NASA platform designers must use every square inch and pound...
Space-Qualified Ultrastable Laser Source Project
National Aeronautics and Space Administration — We propose the development and space-qualification of a 1.06 micron ultrastable fiber laser source that fully satisfies the requirements of this SBIR opportunity...
Wide Bandgap Nanostructured Space Photovoltaics Project
National Aeronautics and Space Administration — Firefly, in collaboration with Rochester Institute of Technology, proposes an STTR program for the development of a wide-bandgap GaP-based space solar cell capable...
FCAPD Protective Coating for Space Tethers Project
National Aeronautics and Space Administration — Alameda Applied Sciences Corporation (AASC) proposes to demonstrate extended service lifetime of space tethers in the Low Earth Orbit (LEO) environment by using...
Ghost Imaging of Space Objects Project
National Aeronautics and Space Administration — The NIAC research effort entitled “The Ghost Imaging of Space Objects” has been inspired by the original 1995 Ghost Imaging and Ghost Diffraction...
Novel Lightweight Magnets for Space Applications Project
National Aeronautics and Space Administration — The Tai-Yang Research Company (TYRC) of Tallahassee, Florida, will design, build and test a superconducting magnet system optimized for low current space based...
Novel Lightweight Magnets for Space Applications Project
National Aeronautics and Space Administration — TYRC of Tallahassee, Florida will design, fabricate and test a novel magnet for space applications. This lightweight magnet will be designed to operate at higher...
Intelligent Agents for Scheduling Space Communications Project
National Aeronautics and Space Administration — With the advent of the new exploration initiative, the number of customers and missions to be supported by the NASA Space Communications infrastructure will increase...
Improvement in Space Food Packaging Methods Project
National Aeronautics and Space Administration — The Space Food Systems Laboratory's (SFSL) current Bulk Overwrap Bag (BOB) package, while simple and effective, leaves room for improvement. Currently, BOBs are...
Directory of Open Access Journals (Sweden)
Banan Maayah
2014-01-01
Full Text Available A new algorithm called multistep reproducing kernel Hilbert space method is represented to solve nonlinear oscillator’s models. The proposed scheme is a modification of the reproducing kernel Hilbert space method, which will increase the intervals of convergence for the series solution. The numerical results demonstrate the validity and the applicability of the new technique. A very good agreement was found between the results obtained using the presented algorithm and the Runge-Kutta method, which shows that the multistep reproducing kernel Hilbert space method is very efficient and convenient for solving nonlinear oscillator’s models.
Leech Lattice Extension of the Non-linear Schrodinger Equation Theory of Einstein spaces
Chapline, George
2015-01-01
Although the nonlinear Schrodinger equation description of Einstein spaces has provided insights into how quantum mechanics might modify the classical general relativistic description of space-time, an exact quantum description of space-times with matter has remained elusive. In this note we outline how the nonlinear Schrodinger equation theory of Einstein spaces might be generalized to include matter by transplanting the theory to the 25+1 dimensional Lorentzian Leech lattice. Remarkably when a hexagonal section of the Leech lattice is set aside as the stage for the nonlinear Schrodinger equation, the discrete automorphism group of the complex Leech lattice with one complex direction fixed can be lifted to continuous Lie group symmetries. In this setting the wave function becomes an 11x11 complex matrix which represents matter degrees of freedom consisting of a 2-form abelian gauge field and vector nonabelian SU(3)xE6 gauge fields together with their supersymmetric partners. The lagrangian field equations fo...
DEFF Research Database (Denmark)
Tatu, Aditya Jayant
defined subspace, the N-links bicycle chain space, i.e. the space of curves with equidistant neighboring landmark points. This in itself is a useful shape space for medical image analysis applications. The Histogram of Gradient orientation based features are many in number and are widely used......This thesis deals with two unrelated issues, restricting curve evolution to subspaces and computing image patches in the equivalence class of Histogram of Gradient orientation based features using nonlinear projection methods. Curve evolution is a well known method used in various applications like...... specific requirements like shape priors or a given data model, and due to limitations of the computer, the computed curve evolution forms a path in some finite dimensional subspace of the space of curves. We give methods to restrict the curve evolution to a finite dimensional linear or implicitly defined...
Micro tube heat exchangers for Space Project
National Aeronautics and Space Administration — Mezzo fabricates micro tube heat exchangers for a variety of applications, including aerospace, automotive racing, Department of Defense ground vehicles, economizers...
Universal Space IP Transparent Proxy Project
National Aeronautics and Space Administration — Communications applications are strategically moving toward Internet Protocol-based architectures and technologies. Despite IP's huge potential, (e.g. cost...
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...
Graphene for Expandable Space Structures Project
National Aeronautics and Space Administration — Graphene's tightly bonded impermeable single atomic layer of carbon offers unrivalled potential for lightweight flexible gas barrier applications. Graphene has been...
Universal Space IP Transparent Proxy Project
National Aeronautics and Space Administration — NASA requires protocols and architectures that will allow reduced levels of mission funding, shorter mission development schedules, and facilitate high availability...
A Thermal Switch for Space Applications Project
National Aeronautics and Space Administration — Various planned NASA missions require thermal switches for active thermal control. As an example cryocoolers, including redundant coolers are incorporated on select...
Autonomous Control of Space Nuclear Reactors Project
National Aeronautics and Space Administration — Nuclear reactors to support future robotic and manned missions impose new and innovative technological requirements for their control and protection instrumentation....
A Heat Switch for Space Applications Project
National Aeronautics and Space Administration — Various planned NASA missions require heat switches for active thermal control. As an example cryocoolers, including redundant coolers are incorporated on select...
Extended phase space of Black Holes in Lovelock gravity with nonlinear electrodynamics
Hendi, S H; Panah, B Eslam
2015-01-01
In this paper, we consider Lovelock gravity in presence of two Born-Infeld types of nonlinear electrodynamics and study their thermodynamical behavior. We extend the phase space by considering cosmological constant as a thermodynamical pressure. We obtain critical values of pressure, volume and temperature and investigate the effects of both the Lovelock gravity and the nonlinear electrodynamics on these values. We plot $P-v$, $T-v$ and $G-T$ diagrams to study the phase transition of these thermodynamical systems. We show that power of the nonlinearity and gravity have opposite effects. We also show how considering cosmological constant, nonlinearity and Lovelock parameters as thermodynamical variables will modify Smarr formula and first law of thermodynamics. In addition, we study the behavior of universal ratio of $\\frac{P_{c}v_{c}}{T_{c}}$ for different values of nonlinearity power of electrodynamics as well as the Lovelock coefficients.
Variational space-time (dis)continuous Galerkin method for nonlinear free surface waves
Gagarina, E; Vegt, van der, N.F.A.; Ambati, V.R.; Bokhove, O.
2013-01-01
A new variational finite element method is developed for nonlinear free surface gravity water waves. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a space-time finite element discretization that is continuous in space and discontinuous in time. The key features of this formulation are: (i) a discrete variational approach that gives rise to conservation of discrete energy and phase space and prese...
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.
Institute of Scientific and Technical Information of China (English)
LI Shoufu
2005-01-01
A series of stability, contractivity and asymptotic stability results of the solutions to nonlinear stiff Volterra functional differential equations (VFDEs) in Banach spaces is obtained, which provides the unified theoretical foundation for the stability analysis of solutions to nonlinear stiff problems in ordinary differential equations(ODEs), delay differential equations(DDEs), integro-differential equations(IDEs) and VFDEs of other type which appear in practice.
MCMC for non-linear state space models using ensembles of latent sequences
2013-01-01
Non-linear state space models are a widely-used class of models for biological, economic, and physical processes. Fitting these models to observed data is a difficult inference problem that has no straightforward solution. We take a Bayesian approach to the inference of unknown parameters of a non-linear state model; this, in turn, requires the availability of efficient Markov Chain Monte Carlo (MCMC) sampling methods for the latent (hidden) variables and model parameters. Using the ensemble ...
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 a...
Energy Technology Data Exchange (ETDEWEB)
Alvarez-Estrada, R.F.
1979-08-01
A comprehensive review of the inverse scattering solution of certain non-linear evolution equations of physical interest in one space dimension is presented. We explain in some detail the interrelated techniques which allow to linearize exactly the following equations: (1) the Korteweg and de Vries equation; (2) the non-linear Schrodinger equation; (3) the modified Korteweg and de Vries equation; (4) the Sine-Gordon equation. We concentrate in discussing the pairs of linear operators which accomplish such an exact linearization and the solution of the associated initial value problem. The application of the method to other non-linear evolution equations is reviewed very briefly.
ANTI-PERIODIC SOLUTIONS FOR FIRST AND SECOND ORDER NONLINEAR EVOLUTION EQUATIONS IN BANACH SPACES
Institute of Scientific and Technical Information of China (English)
WEI Wei; XIANG Xiaoling
2004-01-01
In this paper, a new existence theorem of anti-periodic solutions for a class ofstrongly nonlinear evolution equations in Banach spaces is presentedThe equations con-tain nonlinear monotone operators and a nonmonotone perturbationMoreover, throughan appropriate transformation, the existence of anti-periodic solutions for a class of second-order nonlinear evolution equations is verifiedOur abstract results are illustrated by anexample from quasi-linear partial differential equations with time anti-periodic conditionsand an example from quasi-linear anti-periodic hyperbolic differential equations.
Non-commutative Complex Projective Spaces and the Standard Model
Dolan, Brian P
2003-01-01
The standard model fermion spectrum, including a right handed neutrino, can be obtained as a zero-mode of the Dirac operator on a space which is the product of complex projective spaces of complex dimension two and three. The construction requires the introduction of topologically non-trivial background gauge fields. By borrowing from ideas in Connes' non-commutative geometry and making the complex spaces `fuzzy' a matrix approximation to the fuzzy space allows for three generations to emerge...
Telepresence for Deep Space Missions Project
National Aeronautics and Space Administration — Telepresence sessions between the crew, family members and medical doctors require visual and acoustic privacy. This environment is best achieved in the...
3D Flash LIDAR Space Laser Project
National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...
Intelligent Agents for Scheduling Space Communications Project
National Aeronautics and Space Administration — The new exploration initiative, and the planned new antenna types to be developed in support of that initiative will increase the number and complexity of missions...
Shielded ADR Magnets For Space Applications Project
National Aeronautics and Space Administration — An important consideration of the use of superconducting magnets in ADR applications is shielding of the other instruments in the vicinity of the superconducting...
Space-Qualifiable Cyanate Ester Elastomer Project
National Aeronautics and Space Administration — In Phase 1, CRG demonstrated the feasibility of a novel approach to prepare cyanate ester based elastomers. This approach polymerizes in-situ siloxane within a...
Modular Actuators for Space Applications Project
National Aeronautics and Space Administration — Rocketstar Robotics is proposing the development of a modern dual drive actuator. Rocketstar has put together numerous modern concepts for modular actuators that...
Space-Qualifiable Digital Radar Transceiver Project
National Aeronautics and Space Administration — Historically, radar systems have tended to be either large, complex, power-hungry, purpose-built systems, or extremely simple systems of limited capability. More...
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....... The computation does not use the fact that CPr is formal, nor does it use the Jones isomorphism and negative cyclic homology....
Autonomous Control of Space Nuclear Reactors Project
National Aeronautics and Space Administration — Nuclear reactors to support future lunar and Mars robotic and manned missions impose new and innovative technological requirements for their control and protection...
Individualized Fatigue Meter for Space Exploration Project
National Aeronautics and Space Administration — To ensure mission success, astronauts must maintain a high level of performance even when work-rest schedules result in chronic sleep restriction and circadian...
Advanced Fire Detector for Space Applications Project
National Aeronautics and Space Administration — Reliable and efficient fire detection is a precondition for safe spaceflight. The threat of onboard fire is constant and requires early, fast and unfailing...
Reservoir Cathode for Electric Space Propulsion Project
National Aeronautics and Space Administration — We propose a reservoir cathode to improve performance in both ion and Hall-effect thrusters. We propose to adapt our existing reservoir cathode technology to this...
Reservoir Cathode for Electric Space Propulsion Project
National Aeronautics and Space Administration — We propose a hollow reservoir cathode to improve performance in ion and Hall thrusters. We will adapt our existing reservoir cathode technology to this purpose....
Iodine Hall Thruster for Space Exploration Project
National Aeronautics and Space Administration — Busek Co. Inc. proposes to develop a high power (high thrust) electric propulsion system featuring an iodine fueled Hall Effect Thruster (HET). The system to be...
Ghost Imaging of Space Objects Project
National Aeronautics and Space Administration — Ghost imaging is an optical imaging technique that utilizes the correlations between optical fields in two channels. One of the channels contains the object,...
Space Debris Elimination (SpaDE) Project
National Aeronautics and Space Administration — The amount of debris in low Earth orbit (LEO) has increased rapidly over the last twenty years. This prevalence of debris increases the likelihood of cascading...
Long Duration Space Shelter Shielding Project
National Aeronautics and Space Administration — Physical Sciences Inc. (PSI) has developed fiber reinforced ceramic composites for radiation shielding that can be used for external walls in long duration manned...
Space-Ready Advanced Imaging System Project
National Aeronautics and Space Administration — In this Phase II effort Toyon will increase the state-of-the-art for video/image systems. This will include digital image compression algorithms as well as system...
Space-qualifiable Digital Radar Transceiver Project
National Aeronautics and Space Administration — Radar technology offers a very flexible, powerful tool for applications such as object detection, tracking, and characterization, as well as remote sensing, imaging,...
Efficient Space Borne MMIC Interface Project
National Aeronautics and Space Administration — We are proposing to develop high power, high efficiency Ka-band and W-band amplifiers for future NASA missions. The significance of the innovation primarily lies in...
Deep Space Cryogenic Power Electronics Project
National Aeronautics and Space Administration — Technology Application, Inc. (TAI) is proposing to demonstrate feasibility of implementing silicon germanium (SiGe) strained-gate technology in the power...
Validation of Autonomous Space Systems Project
National Aeronautics and Space Administration — System validation addresses the question “Will the system do the right thing?” When system capability includes autonomy, or more specifically, onboard...
Autonomous Deep-Space Optical Navigation Project
National Aeronautics and Space Administration — Every one of the future exploration architectures being considered by NASA have, at their core, the need to rendezvous and dock with other vehicles or bodies. ...
Iodine Hall Thruster for Space Exploration Project
National Aeronautics and Space Administration — In the Phase I program, Busek Co. Inc. tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high flow iodine feed system,...
Long Duration Space Shelter Shielding Project
National Aeronautics and Space Administration — Physical Sciences Inc. (PSI) has developed a ceramic composite material system that is more effective for shielding both GCR and SPE than aluminum. The composite...
Materials Characterization for Space Manufactured Components Project
National Aeronautics and Space Administration — Long duration missions to the Moon and Mars will place new demands upon components and systems leading to increasingly stringent requirements for safety, quality,...
Green Applications for Space Power Project
National Aeronautics and Space Administration — A key technical difference (aside from the differences in toxicity) between Hydrazine and the green propellant alternatives is the combustion temperature. Both...
Nonlinear Approximation and the Space BV(R2)
1997-01-01
number t let Uf t infgBVQ kf gk LI tVQg where the inmum is taken over all functions g BV of bounded variation on I This and related...all functions g BV of bounded variation on I This and related extremal problems arise in several areas of mathematics such as interpolation of...Q tVQg Here BVQ is the space of functions of bounded variation on Q see x for the de nition of this space and VQf jf jBV is the
Energy Technology Data Exchange (ETDEWEB)
Subalakshmi, R. [Department of Mathematics, Bharathiar University, Coimbatore 641 046 (India)], E-mail: suba.ab.bu@gmail.com; Balachandran, K. [Department of Mathematics, Bharathiar University, Coimbatore 641 046 (India)], E-mail: balachandran_k@lycos.com
2009-11-30
Many practical systems in physical and biological sciences have impulsive dynamical behaviours during the evolution process which can be modeled by impulsive differential equations. This paper studies the approximate controllability properties of nonlinear stochastic impulsive integrodifferential and neutral functional stochastic impulsive integrodifferential equations in Hilbert spaces. Assuming the conditions for the approximate controllability of these linear systems we obtain the sufficient conditions for the approximate controllability of these associated nonlinear stochastic impulsive integrodifferential systems in Hilbert spaces. The results are obtained by using the Nussbaum fixed-point theorem. Finally, two examples are presented to illustrate the utility of the proposed result.
Linear and Nonlinear Time-Frequency Analysis for Parameter Estimation of Resident Space Objects
2017-02-22
AFRL-AFOSR-UK-TR-2017-0023 Linear and Nonlinear Time-Frequency Analysis for Parameter Estimation of Resident Space Objects Marco Martorella... UNIVERSITY DI PISA, DEPARTMENT DI INGEGNERIA Final Report 02/22/2017 DISTRIBUTION A: Distribution approved for public release. AF Office Of Scientific Research...Nonlinear Time-Frequency Analysis for Parameter Estimation of Resident Space Objects 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-14-1-0183 5c. PROGRAM
Jeribi, Aref
2015-01-01
Uncover the Useful Interactions of Fixed Point Theory with Topological StructuresNonlinear Functional Analysis in Banach Spaces and Banach Algebras: Fixed Point Theory under Weak Topology for Nonlinear Operators and Block Operator Matrices with Applications is the first book to tackle the topological fixed point theory for block operator matrices with nonlinear entries in Banach spaces and Banach algebras. The book provides researchers and graduate students with a unified survey of the fundamental principles of fixed point theory in Banach spaces and algebras. The authors present several exten
On projective space bundle with nef normalized tautological line bundle
Yasutake, Kazunori
2011-01-01
In this paper, we study the structure of projective space bundles whose relative anti-canonical line bundle is nef. As an application, we get a characterization of abelian varieties up to finite etale covering.
Low Cost Method of Manufacturing Space Optics Project
National Aeronautics and Space Administration — The Phase I project successfully demonstrated the feasibility of developing a technology that will reduce cost and manufacturing time, broaden design options, and...
Using Heliospheric Imager Data to Improve Space Weather Forecasting Project
National Aeronautics and Space Administration — The objective of this project is to test a new approach for selecting the optimal solar wind model from an ensemble of model runs.Because of the paucity of...
Fast GC for Space Applications Based on PIES Technology Project
National Aeronautics and Space Administration — This SBIR Phase II project is aimed at the development of an analytical instrument which combines the advantages of fast gas chromatography (GC) and a detector that...
Integrated Modeling, Analysis, and Verification for Space Missions Project
National Aeronautics and Space Administration — This project will further MBSE technology in fundamental ways by strengthening the link between SysML tools and framework engineering execution environments. Phoenix...
Enhanced Reliability MEMS Deformable Mirrors for Space Imaging Applications Project
National Aeronautics and Space Administration — The goal of this project is to develop and demonstrate a reliable, fault-tolerant wavefront control system that will fill a critical technology gap in NASA's vision...
Evolution of classical projected phase space density in billiards
Indian Academy of Sciences (India)
Debabrata Biswas
2005-04-01
The classical phase space density projected on to the configuration space offers a means of comparing classical and quantum evolution. In this alternate approach that we adopt here, we show that for billiards, the eigenfunctions of the coarse-grained projected classical evolution operator are identical to a first approximation to the quantum Neumann eigenfunctions. Moreover, there exists a correspondence between the respective eigenvalues although their time evolutions differ.
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
The nonlinear evolution of de Sitter space instabilities
Niemeyer, J C; Niemeyer, Jens C.; Bousso, Raphael
2000-01-01
We investigate the quantum evolution of large black holes that nucleate spontaneously in de Sitter space. By numerical computation in the s-wave and one-loop approximations, we verify claims that such black holes can initially "anti-evaporate" instead of shrink. We show, however, that this is a transitory effect. It is followed by an evaporating phase, which we are able to trace until the black holes are small enough to be treated as Schwarzschild. Under generic perturbations, the nucleated geometry is shown to decay into a ring of de Sitter regions connected by evaporating black holes. This confirms that de Sitter space is globally unstable and fragments into disconnected daughter universes.
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.
Finite element method for nonlinear Riesz space fractional diffusion equations on irregular domains
Yang, Z.; Yuan, Z.; Nie, Y.; Wang, J.; Zhu, X.; Liu, F.
2017-02-01
In this paper, we consider two-dimensional Riesz space fractional diffusion equations with nonlinear source term on convex domains. Applying Galerkin finite element method in space and backward difference method in time, we present a fully discrete scheme to solve Riesz space fractional diffusion equations. Our breakthrough is developing an algorithm to form stiffness matrix on unstructured triangular meshes, which can help us to deal with space fractional terms on any convex domain. The stability and convergence of the scheme are also discussed. Numerical examples are given to verify accuracy and stability of our scheme.
Nonlinear dynamics of phase space zonal structures and energetic particle physics in fusion plasmas
Zonca, Fulvio; Briguglio, Sergio; Fogaccia, Giuliana; Vlad, Gregorio; Wang, Xin
2014-01-01
A general theoretical framework for investigating nonlinear dynamics of phase space zonal structures is presented in this work. It is then, more specifically, applied to the limit where the nonlinear evolution time scale is smaller or comparable to the wave-particle trapping period. In this limit, both theoretical and numerical simulation studies show that non-adiabatic frequency chirping and phase locking could lead to secular resonant particle transport on meso- or macro-scales. The interplay between mode structures and resonant particles then provides the crucial ingredient to properly understand and analyze the nonlinear dynamics of Alfv\\'en wave instabilities excited by non-perturbative energetic particles in burning fusion plasmas. Analogies with autoresonance in nonlinear dynamics and with superradiance in free electron lasers are also briefly discussed.
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…
On the uniqueness of minimal projections in Banach spaces
Directory of Open Access Journals (Sweden)
Ewa Szlachtowska
2012-01-01
Full Text Available Let \\(X\\ be a uniformly convex Banach space with a continuous semi-inner product. We investigate the relation of orthogonality in \\(X\\ and generalized projections acting on \\(X\\. We prove uniqueness of orthogonal and co-orthogonal projections.
Suppression of space charge induced beam halo in nonlinear focusing channel
Batygin, Yuri K.; Scheinker, Alexander; Kurennoy, Sergey; Li, Chao
2016-04-01
An intense non-uniform particle beam exhibits strong emittance growth and halo formation in focusing channels due to nonlinear space charge forces of the beam. This phenomenon limits beam brightness and results in particle losses. The problem is connected with irreversible distortion of phase space volume of the beam in conventional focusing structures due to filamentation in phase space. Emittance growth is accompanied by halo formation in real space, which results in inevitable particle losses. A new approach for solving a self-consistent problem for a matched non-uniform beam in two-dimensional geometry is discussed. The resulting solution is applied to the problem of beam transport, while avoiding emittance growth and halo formation by the use of nonlinear focusing field. Conservation of a beam distribution function is demonstrated analytically and by particle-in-cell simulation for a beam with a realistic beam distribution.
Suppression of Space Charge Induced Beam Halo in Nonlinear Focusing Channel
Batygin, Yuri K; Kurennoy, Sergey; Li, Chao
2016-01-01
An intense non-uniform particle beam exhibits strong emittance growth and halo formation in focusing channels due to nonlinear space charge forces of the beam. This phenomenon limits beam brightness and results in particle losses. The problem is connected with irreversible distortion of phase space volume of the beam in conventional focusing structures due to filamentation in phase space. Emittance growth is accompanied by halo formation in real space, which results in inevitable particle losses. A new approach for solving a self-consistent problem for a matched non-uniform beam in two-dimensional geometry is discussed. The resulting solution is applied to the problem of beam transport, while avoiding emittance growth and halo formation by the use of nonlinear focusing field. Conservation of a beam distribution function is demonstrated analytically and by particle-in-cell simulation for a beam with a realistic beam distribution.
An Open Specification for Space Project Mission Operations Control Architectures
Hooke, A.; Heuser, W. R.
1995-01-01
An 'open specification' for Space Project Mission Operations Control Architectures is under development in the Spacecraft Control Working Group of the American Institute for Aeronautics and Astro- nautics. This architecture identifies 5 basic elements incorporated in the design of similar operations systems: Data, System Management, Control Interface, Decision Support Engine, & Space Messaging Service.
On the Quaternion Ball and the Quaternion Projective Space
Institute of Scientific and Technical Information of China (English)
Qi Keng LU
2005-01-01
Since the quaternion ball was used to study the AdS/CFT problems for spinor fields, it is worthwhile to study further the geometry (in sense of Klein) and analysis on it and on its extended space (in the sense of Behnke-Thullen), the quaternion projective space.
A Projected Lagrangian Algorithm for Nonlinear Minimax Optimization.
1979-11-01
T Problem 5: Charalambous and Bandler (1976) # 1. f 1(x ) 2- + _ f3(x) = 2 exp(-x+ X2) Starting Pointz xO (1,..1)T 61 Problem 6: Rosen and Suzuki...Charalambous and Bandler ,#l) 2 3 1 6 6 6 (Rosen and Suzuki) 4 4 2 7 10 The results demonstrate that at least on a limited set of test problems the...and Numerical Methods for Stiff Differential Equations. Charalambous, C. and J.W. Bandler (1974). Nonlinear minimax optimization as a sequence of least
Existence and Boundedness of Solutions for Nonlinear Volterra Difference Equations in Banach Spaces
Directory of Open Access Journals (Sweden)
Rigoberto Medina
2016-01-01
Full Text Available We consider a class of nonlinear discrete-time Volterra equations in Banach spaces. Estimates for the norm of operator-valued functions and the resolvents of quasi-nilpotent operators are used to find sufficient conditions that all solutions of such equations are elements of an appropriate Banach space. These estimates give us explicit boundedness conditions. The boundedness of solutions to Volterra equations with infinite delay is also investigated.
Nonlinear state space model identification of synchronous generators
Energy Technology Data Exchange (ETDEWEB)
Dehghani, M.; Nikravesh, S.K.Y. [Electrical Engineering Department, Amirkabir University of Technology, Tehran (Iran)
2008-05-15
A method for identification of a synchronous generator is suggested in this paper. The method uses the theoretical relations of machine parameters and the Prony method to find the state space model of the system. Such models are useful for controller design and stability tests. The proposed identification method is applied to a third order model of a synchronous generator. In this study, the field voltage is considered as the input and the active output power and the rotor angle are considered as the outputs of the synchronous generator. Simulation results show good accuracy of the identified model. (author)
Nonlinear Data Analysis Tool for Scramjets and Other Engines Project
National Aeronautics and Space Administration — The UCDS process is the result of 50 years of research into combustion instability by the worlds leading scientists and engineers. The breakthroughs that created...
Quantitative Emboli Detection Using Nonlinear Ultrasound Technique Project
National Aeronautics and Space Administration — We propose to develop a new and innovative method for the detection and classification of emboli flowing into the brain through Carotid arteries, specifically for...
National Aeronautics and Space Administration — Impact Technologies in collaboration with Pratt & Whitney and Wright State University, proposes to continue the development of an innovative nonlinear adaptive...
On the correct formulation of a nonlinear differential equations in Banach space
Directory of Open Access Journals (Sweden)
Mahmoud M. El-Borai
2001-01-01
Full Text Available We study, the existence and uniqueness of the initial value problems in a Banach space E for the abstract nonlinear differential equation (dn−1/dtn−1(du/dt+Au=B(tu+f(t,W(t, and consider the correct solution of this problem. We also give an application of the theory of partial differential equations.
On Landau damping of dipole modes by non-linear space charge and octupoles
Möhl, D
1995-01-01
The joint effect of space-charge non-linearities and octupole lenses is important for Landau damping of coherent instabilities. The octupole strength required for stabilisation can depend strongly on the sign of the excitation current of the lenses. This note tries to extend results, previously obtained for coasting beams and rigid bunches, to more general head--tail modes.
Institute of Scientific and Technical Information of China (English)
Tetsuya Ishiwata; Masayoshi Tsutsumi
2000-01-01
Semidiscretization in space of nonlinear degenerate parabolic equations of nondivergent form is presented, under zero Dirichlet boundary condition. It is shown that semidiscrete solutions blow up in finite time. In particular, the asymptotic behavior of blowing-up solutions, is discussed precisely.
Variational space-time (dis)continuous Galerkin method for nonlinear free surface waves
Gagarina, E.; Vegt, van der J.J.W.; Ambati, V.R.; Bokhove, O.
2013-01-01
A new variational finite element method is developed for nonlinear free surface gravity water waves. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a space-time finite element discretization that is cont
Integrability of Nonlinear Equations of Motion on Two-Dimensional World Sheet Space-Time
Institute of Scientific and Technical Information of China (English)
YAN Jun
2005-01-01
The integrability character of nonlinear equations of motion of two-dimensional gravity with dynamical torsion and bosonic string coupling is studied in this paper. The space-like and time-like first integrals of equations of motion are also found.
Nonlinear scale space with spatially varying stopping time.
Gilboa, Guy
2008-12-01
A general scale space algorithm is presented for denoising signals and images with spatially varying dominant scales. The process is formulated as a partial differential equation with spatially varying time. The proposed adaptivity is semi-local and is in conjunction with the classical gradient-based diffusion coefficient, designed to preserve edges. The new algorithm aims at maximizing a local SNR measure of the denoised image. It is based on a generalization of a global stopping time criterion presented recently by the author and colleagues. Most notably, the method works well also for partially textured images and outperforms any selection of a global stopping time. Given an estimate of the noise variance, the procedure is automatic and can be applied well to most natural images.
Free-Space Nonlinear Beam Combining Towards Filamentation
Rostami, Shermineh; Kepler, Daniel; Baudelet, Matthieu; Litchinitser, Natalia M; Richardson, Martin
2016-01-01
Multi-filamentation opens new degrees of freedom for manipulating electromagnetic waves in air. However, without control, multiple filament interactions, including attraction, repulsion or fusion often result in formation of complex disordered filament distributions. Moreover, high power beams conventionally used in multi-filament formation experiments often cause significant surface damage. The growing number of applications for laser filaments requires fine control of their formation and propagation. We demonstrate, experimentally and theoretically, that the attraction and fusion of ultrashort beams with initial powers below the critical value enable the eventual formation of a filament downstream. Filament formation is delayed to a predetermined distance in space, avoiding optical damage to external beam optics while still enabling robust filaments with controllable properties as if formed from a single high power beam. This paradigm introduces new opportunities for filament engineering eliminating the nee...
Contractive projections in Orlicz sequence spaces
Directory of Open Access Journals (Sweden)
Beata Randrianantoanina
2004-01-01
Full Text Available We characterize norm-one complemented subspaces of Orlicz sequence spaces ℓM equipped with either Luxemburg or Orlicz norm, provided that the Orlicz function M is sufficiently smooth and sufficiently different from the square function. We measure smoothness of M using AC1 and AC2 classes introduced by Maleev and Troyanski in 1991, and the condition for M to be different from a square function is essentially a requirement that the second derivative M″ of M cannot have a finite nonzero limit at zero. This paper treats the real case; the complex case follows from previously known results.
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.
Liu, Peipei; Sohn, Hoon; Park, Byeongjin
2015-06-01
Damage often causes a structural system to exhibit severe nonlinear behaviors, and the resulting nonlinear features are often much more sensitive to the damage than their linear counterparts. This study develops a laser nonlinear wave modulation spectroscopy (LNWMS) so that certain types of damage can be detected without any sensor placement. The proposed LNWMS utilizes a pulse laser to generate ultrasonic waves and a laser vibrometer for ultrasonic measurement. Under the broadband excitation of the pulse laser, a nonlinear source generates modulations at various frequency values due to interactions among various input frequency components. State space attractors are reconstructed from the ultrasonic responses measured by LNWMS, and a damage feature called Bhattacharyya distance (BD) is computed from the state space attractors to quantify the degree of damage-induced nonlinearity. By computing the BD values over the entire target surface using laser scanning, damage can be localized and visualized without relying on the baseline data obtained from the pristine condition of a target structure. The proposed technique has been successfully used for visualizing fatigue crack in an aluminum plate and delamination and debonding in a glass fiber reinforced polymer wind turbine blade.
Space Radiation Effects on Inflatable Habitat Materials Project
Waller, Jess M.; Nichols, Charles
2015-01-01
The Space Radiation Effects on Inflatable Habitat Materials project provides much needed risk reduction data to assess space radiation damage of existing and emerging materials used in manned low-earth orbit, lunar, interplanetary, and Martian surface missions. More specifically, long duration (up to 50 years) space radiation damage will be quantified for materials used in inflatable structures (1st priority), as well as for habitable composite structures and space suits materials (2nd priority). The data acquired will have relevance for nonmetallic materials (polymers and composites) used in NASA missions where long duration reliability is needed in continuous or intermittent radiation fluxes. This project also will help to determine the service lifetimes for habitable inflatable, composite, and space suit materials.
Space research scientific and educational project of Moscow State University
Krasotkin, S. A.; Mjagkova, I. N.; Panasyuk, M. I.; Radchenko, V. V.; Ryazantseva, M. O.
The scientific and educational project of space research was initiated in Lomonosov Moscow State University in order to incorporate modern space research in the university and high education, to popularize basics of space physics, and to enhance public interest in space exploration. On 20 January, 2005 the First Russian University Satellite UNIVERSITETSKIY 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 center, was designed and developed in Moscow State University. The scientific program of the mission include measurements of space radiation in different energy channels, and Earth UV luminosity and lightening. A multimedia lectures "Life of the Earth in the Solar Atmosphere" containing the basic information and demonstrations of the 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 was created a dozen of special computerized lab exercises based on the experimental quasi-realtime data obtained from our satellites. Students specialized in space physics from a few Russian universities are involved in scientific work based. Educational program of the project (both the multimedia lectures and lab exercises) is concentrated to upper high school, middle university and special level for space physics students. The space research scientific and educational activity of Moscow State University is a non-profit project and is open for all interested parties.
The Projection Neural Network for Solving Convex Nonlinear Programming
Yang, Yongqing; Xu, Xianyun
In this paper, a projection neural network for solving convex optimization is investigated. Using Lyapunov stability theory and LaSalle invariance principle, the proposed network is showed to be globally stable and converge to exact optimal solution. Two examples show the effectiveness of the proposed neural network model.
Institute of Scientific and Technical Information of China (English)
GUYanfeng; ZHANGYe; QUANTaifan
2003-01-01
A challenging problem in using hyper-spectral data is to eliminate redundancy and preserve useful spectral information for applications. In this pa-per, a kernel-based nonlinear subspace projection (KNSP)method is proposed for feature extraction and dimension-ality reduction in hyperspectral images. The proposed method includes three key steps: subspace partition of hyperspectral data, feature extraction using kernel-based principal component analysis (KPCA) and feature selec-tion based on class separability in the subspaces. Accord-ing to the strong correlation between neighboring bands,the whole data space is partitioned to requested subspaces.In each subspace, the KPCA method is used to effectively extract spectral feature and eliminate redundancies. A criterion function based on class discrimination and sepa-rability is used for the transformed feature selection. For the purpose of testifying its effectiveness, the proposed new method is compared with the classical principal component analysis (PCA) and segmented principal component trans-formation (SPCT). A hyperspectral image classification is performed on AVIRIS data. which have 224 svectral bands.Experimental results show that KNSP is very effective for feature extraction and dimensionality reduction of hyper-spectral data and provides significant improvement over classical PCA and current SPCT technique.
Chaotic behaviour of nonlinear coupled reaction–diffusion system in four-dimensional space
Indian Academy of Sciences (India)
Li Zhang; Shutang Liu; Chenglong Yu
2014-06-01
In recent years, nonlinear coupled reaction–diffusion (CRD) system has been widely investigated by coupled map lattice method. Previously, nonlinear behaviour was observed dynamically when one or two of the three variables in the discrete system change. In this paper, we consider the chaotic behaviour when three variables change, which is called as four-dimensional chaos. When two parameters in the discrete system are unknown, we first give the existing condition of the chaos in four-dimensional space by the generalized definitions of spatial periodic orbits and spatial chaos. In addition, the chaotic behaviour will vary with the parameters. Then we propose a generalized Lyapunov exponent in four-dimensional space to characterize the different effects of parameters on the chaotic behaviour, which has not been studied in detail. In order to verify the chaotic behaviour of the system and the different effects clearly, we simulate the dynamical behaviour in two- and three-dimensional spaces.
Existence Results for Differential Inclusions with Nonlinear Growth Conditions in Banach Spaces
Directory of Open Access Journals (Sweden)
Messaoud Bounkhel
2013-01-01
Full Text Available In the Banach space setting, the existence of viable solutions for differential inclusions with nonlinear growth; that is, ẋ(t∈F(t,x(t a.e. on I, x(t∈S, ∀t∈I, x(0=x0∈S, (*, where S is a closed subset in a Banach space , I=[0,T], (T>0, F:I×S→, is an upper semicontinuous set-valued mapping with convex values satisfying F(t,x⊂c(tx+xp, ∀(t,x∈I×S, where p∈ℝ, with p≠1, and c∈C([0,T],ℝ+. The existence of solutions for nonconvex sweeping processes with perturbations with nonlinear growth is also proved in separable Hilbert spaces.
Sun, Xiaodian; Jin, Li; Xiong, Momiao
2008-01-01
It is system dynamics that determines the function of cells, tissues and organisms. To develop mathematical models and estimate their parameters are an essential issue for studying dynamic behaviors of biological systems which include metabolic networks, genetic regulatory networks and signal transduction pathways, under perturbation of external stimuli. In general, biological dynamic systems are partially observed. Therefore, a natural way to model dynamic biological systems is to employ nonlinear state-space equations. Although statistical methods for parameter estimation of linear models in biological dynamic systems have been developed intensively in the recent years, the estimation of both states and parameters of nonlinear dynamic systems remains a challenging task. In this report, we apply extended Kalman Filter (EKF) to the estimation of both states and parameters of nonlinear state-space models. To evaluate the performance of the EKF for parameter estimation, we apply the EKF to a simulation dataset and two real datasets: JAK-STAT signal transduction pathway and Ras/Raf/MEK/ERK signaling transduction pathways datasets. The preliminary results show that EKF can accurately estimate the parameters and predict states in nonlinear state-space equations for modeling dynamic biochemical networks.
Gain Scheduling Control of Nonlinear Systems Based on Neural State Space Models
DEFF Research Database (Denmark)
Bendtsen, Jan Dimon; Stoustrup, Jakob
2003-01-01
This paper presents a novel method for gain scheduling control of nonlinear systems based on extraction of local linear state space models from neural networks with direct application to robust control. A neural state space model of the system is first trained based on in- and output training...... samples from the system, after which linearized state space models are extracted from the neural network in a number of operating points according to a simple and computationally cheap scheme. Robust observer-based controllers can then be designed in each of these operating points,and gain scheduling...
Recursive prediction error methods for online estimation in nonlinear state-space models
Directory of Open Access Journals (Sweden)
Dag Ljungquist
1994-04-01
Full Text Available Several recursive algorithms for online, combined state and parameter estimation in nonlinear state-space models are discussed in this paper. Well-known algorithms such as the extended Kalman filter and alternative formulations of the recursive prediction error method are included, as well as a new method based on a line-search strategy. A comparison of the algorithms illustrates that they are very similar although the differences can be important for the online tracking capabilities and robustness. Simulation experiments on a simple nonlinear process show that the performance under certain conditions can be improved by including a line-search strategy.
Lu, Zhao; Sun, Jing; Butts, Kenneth
2016-02-03
A giant leap has been made in the past couple of decades with the introduction of kernel-based learning as a mainstay for designing effective nonlinear computational learning algorithms. In view of the geometric interpretation of conditional expectation and the ubiquity of multiscale characteristics in highly complex nonlinear dynamic systems [1]-[3], this paper presents a new orthogonal projection operator wavelet kernel, aiming at developing an efficient computational learning approach for nonlinear dynamical system identification. In the framework of multiresolution analysis, the proposed projection operator wavelet kernel can fulfill the multiscale, multidimensional learning to estimate complex dependencies. The special advantage of the projection operator wavelet kernel developed in this paper lies in the fact that it has a closed-form expression, which greatly facilitates its application in kernel learning. To the best of our knowledge, it is the first closed-form orthogonal projection wavelet kernel reported in the literature. It provides a link between grid-based wavelets and mesh-free kernel-based methods. Simulation studies for identifying the parallel models of two benchmark nonlinear dynamical systems confirm its superiority in model accuracy and sparsity.
A geometric approach to quantum control in projective hilbert spaces
Pastorello, Davide
2017-02-01
A quantum theory in a finite-dimensional Hilbert space can be formulated as a proper geometric Hamiltonian theory as explained in [2, 3, 7, 9]. From this point of view a quantum system can be described within a classical-like framework where quantum dynamics is represented by a Hamiltonian flow in the phase space given by a projective Hilbert space. This paper is devoted to investigating how the notion of an accessibility algebra from classical control theory can be applied within the geometric Hamiltonian formulation of quantum mechanics to study controllability of a quantum system. A new characterization of quantum controllability in terms of Killing vector fields w.r.t. the Fubini-Study metric on projective space is also discussed.
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].
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.
Dyja, Robert; van der Zee, Kristoffer G
2016-01-01
We present an adaptive methodology for the solution of (linear and) non-linear time dependent problems that is especially tailored for massively parallel computations. The basic concept is to solve for large blocks of space-time unknowns instead of marching sequentially in time. The methodology is a combination of a computationally efficient implementation of a parallel-in-space-time finite element solver coupled with a posteriori space-time error estimates and a parallel mesh generator. This methodology enables, in principle, simultaneous adaptivity in both space and time (within the block) domains. We explore this basic concept in the context of a variety of time-steppers including $\\Theta$-schemes and Backward Differentiate Formulas. We specifically illustrate this framework with applications involving time dependent linear, quasi-linear and semi-linear diffusion equations. We focus on investigating how the coupled space-time refinement indicators for this class of problems affect spatial adaptivity. Final...
Deliktaş, Ekin; Teymür, Mevlüt
2017-07-01
In this study, the propagation of shear horizontal (SH) waves in a nonlinear elastic half space covered by a nonlinear elastic layer with a slowly varying interface is examined. The constituent materials are assumed to be homogenous, isotropic, elastic and having different mechanical properties. By employing the method of multiple scales, a nonlinear Schrödinger equation (NLS) with variable coefficients is derived for the nonlinear self-modulation of SH waves. We examine the effects of dispersion, irregularity of the interface and nonlinearity on the propagation characteristics of SH waves.
Directory of Open Access Journals (Sweden)
Esfandiar, H.
2013-05-01
Full Text Available In this paper, based on the VoigtKelvin constitutive model, nonlinear dynamic modelling and state space representation of a viscoelastic beam acting as a flexible robotic manipulator is investigated. Complete nonlinear dynamic modelling of a viscoelastic beam without premature linearisation of dynamic equations is developed. The adopted method is capable of reproducing nonlinear dynamic effects, such as beam stiffening due to centrifugal and Coriolis forces induced by rotation of the joints. Structural damping effects on the models dynamic behaviour are also shown. A reliable model for a viscoelastic beam is subsequently presented. The governing equations of motion are derived using Hamiltons principle, and using the finite difference method, nonlinear partial differential equations are reduced to ordinary differential equations. For the purpose of flexible manipulator control, the standard form of state space equations for the viscoelastic link and the actuator is obtained. Simulation results indicate substantial improvements in dynamic behaviour, and a parameter sensitivity study is carried out to investigate the effect of structural damping on the vibration amplitude.
Nonlinear free vibrations of beams in space due to internal resonance
Stoykov, S.; Ribeiro, P.
2011-08-01
The geometrically nonlinear free vibrations of beams with rectangular cross section are investigated using a p-version finite element method. The beams may vibrate in space, hence they may experience longitudinal, torsional and non-planar bending deformations. The model is based on Timoshenko's theory for bending and assumes that, under torsion, the cross section rotates as a rigid body and is free to warp in the longitudinal direction, as in Saint-Venant's theory. The geometrical nonlinearity is taken into account by considering Green's nonlinear strain tensor. Isotropic and elastic beams are investigated and generalised Hooke's law is used. The equation of motion is derived by the principle of virtual work. Mostly clamped-clamped beams are investigated, although other boundary conditions are considered for validation purposes. Employing the harmonic balance method, the differential equations of motion are converted into a nonlinear algebraic form and then solved by a continuation method. One constant term, odd and even harmonics are assumed in the Fourier series and convergence with the number of harmonics is analysed. The variation of the amplitude of vibration with the frequency of vibration is determined and presented in the form of backbone curves. Coupling between modes is investigated, internal resonances are found and the ensuing multimodal oscillations are described. Some of the couplings discovered lead from planar oscillations to oscillations in the three dimensional space.
Directory of Open Access Journals (Sweden)
Souad Larabi Marie-Sainte
2017-01-01
Full Text Available This article consists of using biologically inspired algorithms in order to detect potentially interesting structures in large and multidimensional data sets. Data exploration and the detection of interesting structures are based on the use of Projection Pursuit that involves the definition and the optimization of an index associated with each direction or projection. The optimization of a projection index should provide a set of multiple optima that is expected to correspond to interesting graphical representations in low dimensional space. The implementation of the bio-inspired algorithms along with the projection pursuit develops a new software called EPP-Lab. Projection pursuit is widely used in different scientific domains (biology, pharmacy, bioinformatics, biometry, etc but not widely present in the well-known softwares. EPP-Lab is dedicated to recognize and visualize clusters and outlying observations on one dimension from high dimensional and multivariate data sets. It includes different statistical techniques for results analysis. It provides several features and gives the user the option to adjust the parameters of the selected bio-inspired methods or to use defaults values. EPP-Lab is a unique software for detection, visualization and analysis of non-linear structures. The performance of this tool has been validated by testing different real and simulated data sets.
An iterative regularization method for nonlinear problems based on Bregman projections
Maaß, Peter; Strehlow, Robin
2016-11-01
In this paper, we present an iterative method for the regularization of ill-posed, nonlinear problems. The approach is based on the Bregman projection onto stripes the width of which is controlled by both the noise level and the structure of the operator. In our investigations, we follow (Lorenz et al 2014 SIAM J. Imaging Sci. 7 1237-62) and extend the respective method to the setting of nonlinear operators. Furthermore, we present a proof for the regularizing properties of the method.
An Inhomogeneous Space-Time Patching Model Based on a Nonlocal and Nonlinear Schrodinger Equation
Dantas, Christine C
2016-01-01
We consider an integrable, nonlocal and nonlinear, Schr\\"odinger equation (NNSE) as a model for building space-time patchings in inhomogeneous loop quantum cosmology (LQC). We briefly review exact solutions of the NNSE, specially those obtained through "geometric equivalence" methods. Furthemore, we argue that the integrability of the NNSE could be linked to consistency conditions derived from LQC, under the assumption that the patchwork dynamics behaves as an integrable many-body system.
Non-linear shape functions over time in the space-time finite element method
Directory of Open Access Journals (Sweden)
Kacprzyk Zbigniew
2017-01-01
Full Text Available This work presents a generalisation of the space-time finite element method proposed by Kączkowski in his seminal of 1970’s and early 1980’s works. Kączkowski used linear shape functions in time. The recurrence formula obtained by Kączkowski was conditionally stable. In this paper, non-linear shape functions in time are proposed.
Numerical Simulations for the Space-Time Variable Order Nonlinear Fractional Wave Equation
Directory of Open Access Journals (Sweden)
Nasser Hassan Sweilam
2013-01-01
Full Text Available The explicit finite-difference method for solving variable order fractional space-time wave equation with a nonlinear source term is considered. The concept of variable order fractional derivative is considered in the sense of Caputo. The stability analysis and the truncation error of the method are discussed. To demonstrate the effectiveness of the method, some numerical test examples are presented.
On the System of Nonlinear Mixed Implicit Equilibrium Problems in Hilbert Spaces
Directory of Open Access Journals (Sweden)
Yeol Je Cho
2010-01-01
Full Text Available We use the Wiener-Hopf equations and the Yosida approximation notions to prove the existence theorem of a system of nonlinear mixed implicit equilibrium problems (SMIE in Hilbert spaces. The algorithm for finding a solution of the problem (SMIE is suggested; the convergence criteria and stability of the iterative algorithm are discussed. The results presented in this paper are more general and are viewed as an extension, refinement, and improvement of the previously known results in the literature.
Frequency map analysis of resonances in a nonlinear lattice with space charge
Energy Technology Data Exchange (ETDEWEB)
Turchetti, G. E-mail: turchetti@bo.infn.it; Bazzani, A.; Bergamini, F.; Rambaldi, S.; Hofmann, I.; Bongini, L.; Franchetti, G
2001-05-21
In storage rings for heavy ion fusion beam losses must be minimized. During bunch compression high space charge is reached and the reciprocal effects between the collective modes of the beam and the single particle lattice nonlinearities must be considered to understand the problem of resonance crossing and halo formation. We show that the frequency map analysis of particle in core models gives an adequate description of the resonance network and of the chaotic regions where the halo particles can diffuse.
GLOBAL SOLUTIONS OF SYSTEMS OF NONLINEAR IMPULSIVE VOLTERRA INTEGRAL EQUATIONS IN BANACH SPACES
Institute of Scientific and Technical Information of China (English)
陈芳启; 陈予恕
2001-01-01
The existence of solutions for systems of nonlinear impulsive Volterra integral equations on the infinite interval R+ with an infinite number of moments of impulse effect in Banach spaces is studied. Some existence theorems of extremal solutions are obtained,which extend the related results for this class of equations on a finite interval with a finite number of moments of impulse effect. The results are demonstrated by means of an example of an infinite systems for impulsive integral equations.
Directory of Open Access Journals (Sweden)
M. Boudjema
2003-01-01
Full Text Available The elastic response of many rocks to quasistatic stress changes is highly nonlinear and hysteretic, displaying discrete memory. Rocks also display unusual nonlinear response to dynamic stress changes. A model to describe the elastic behavior of rocks and other consolidated materials is called the Preisach-Mayergoyz (PM space model. In contrast to the traditional analytic approach to stress-strain, the PM space picture establishes a relationship between the quasistatic data and a number density of hysteretic mesoscopic elastic elements in the rock. The number density allows us to make quantitative predictions of dynamic elastic properties. Using the PM space model, we analyze a complex suite of quasistatic stress-strain data taken on Berea sandstone. We predict a dynamic bulk modulus and a dynamic shear modulus surface as a function of mean stress and shear stress. Our predictions for the dynamic moduli compare favorably to moduli derived from time of flight measurements. We derive a set of nonlinear elastic constants and a set of constants that describe the hysteretic behavior of the sandstone.
Persistence of solutions to nonlinear evolution equations in weighted Sobolev spaces
Directory of Open Access Journals (Sweden)
Xavier Carvajal Paredes
2010-11-01
Full Text Available In this article, we prove that the initial value problem associated with the Korteweg-de Vries equation is well-posed in weighted Sobolev spaces $mathcal{X}^{s,heta}$, for $s geq 2heta ge 2$ and the initial value problem associated with the nonlinear Schrodinger equation is well-posed in weighted Sobolev spaces $mathcal{X}^{s,heta}$, for $s geq heta geq 1$. Persistence property has been proved by approximation of the solutions and using a priori estimates.
A Fully Discrete Galerkin Method for a Nonlinear Space-Fractional Diffusion Equation
Directory of Open Access Journals (Sweden)
Yunying Zheng
2011-01-01
Full Text Available The spatial transport process in fractal media is generally anomalous. The space-fractional advection-diffusion equation can be used to characterize such a process. In this paper, a fully discrete scheme is given for a type of nonlinear space-fractional anomalous advection-diffusion equation. In the spatial direction, we use the finite element method, and in the temporal direction, we use the modified Crank-Nicolson approximation. Here the fractional derivative indicates the Caputo derivative. The error estimate for the fully discrete scheme is derived. And the numerical examples are also included which are in line with the theoretical analysis.
Maj, Omar
2008-01-01
This is the second part of a work aimed to study complex-phase oscillatory solutions of nonlinear symmetric hyperbolic systems. We consider, in particular, the case of one space dimension. That is a remarkable case, since one can always satisfy the \\emph{naive} coherence condition on the complex phases, which is required in the construction of the approximate solution. Formally the theory applies also in several space dimensions, but the \\emph{naive} coherence condition appears to be too restrictive; the identification of the optimal coherence condition is still an open problem.
Küchler, Sebastian; Meurer, Thomas; Jacobs, Laurence J; Qu, Jianmin
2009-03-01
This study investigates two-dimensional wave propagation in an elastic half-space with quadratic nonlinearity. The problem is formulated as a hyperbolic system of conservation laws, which is solved numerically using a semi-discrete central scheme. These numerical results are then analyzed in the frequency domain to interpret the nonlinear effects, specifically the excitation of higher-order harmonics. To quantify and compare the nonlinearity of different materials, a new parameter is introduced, which is similar to the acoustic nonlinearity parameter beta for one-dimensional longitudinal waves. By using this new parameter, it is found that the nonlinear effects of a material depend on the point of observation in the half-space, both the angle and the distance to the excitation source. Furthermore it is illustrated that the third-order elastic constants have a linear effect on the acoustic nonlinearity of a material.
Institute of Scientific and Technical Information of China (English)
文双春; 范滇元
2002-01-01
Spatiotemporal instability in nonlinear dispersive media is investigated on the basis of the nonlinear envelope equation. A general expression for instability gain which includes the effects of space-time focusing, arbitrarily higher-order dispersions and self-steepening is obtained. It is found that, for both normal and anomalous group-velocity dispersions, space-time focusing may lead to the appearance of new instability regions and influence the original instability gain spectra mainly by shrinking their regions. The region of the original instability gain spectrum shrinks much more in normal dispersion case than in anomalous one. In the former case, space-time focusing completely suppresses the growing of higher frequency components. In addition, we find that all the oddth-order dispersions contribute none to instability, while all the eventh-order dispersions influence instability region and do not influence the maximum instability gain, therein the fourth-order dispersion plays the same role as space-time focusing in spatiotemporal instability. The main role played by self-steepening in spatiotemporal instability is that it reduces the instability gain and exerts much more significant influence on the new instability regions resulting from space-time focusing.
Non-linear diffusion in RD and in Hilbert Spaces, a Cylindrical/Functional Integral Study
Botelho, Luiz Carlos Lobato
2010-01-01
We present a proof for the existence and uniqueness of weak solutions for a cut-off and non cut-off model of non-linear diffusion equation in finite-dimensional space RD useful for modelling flows on porous medium with saturation, turbulent advection, etc. - and subject to deterministic or stochastic (white noise) stirrings. In order to achieve such goal, we use the powerful results of compacity on functional Lp spaces (the Aubin-Lion Theorem). We use such results to write a path-integral solution for this problem. Additionally, we present the rigourous functional integral solutions for the Linear Diffussion equation defined in Infinite-Dimensional Spaces (Separable Hilbert Spaces). These further results are presented in order to be useful to understand Polymer cylindrical surfaces probability distributions and functionals on String theory.
Contamination and Radiation Effects on Nonlinear Crystals for Space Laser Systems
Abdeldayem, Hossain A.; Dowdye, Edward; Jamison, Tracee; Canham, John; Jaeger, Todd
2005-01-01
Space Lasers are vital tools for NASA s space missions and military applications. Although, lasers are highly reliable on the ground, several past space laser missions proved to be short-lived and unreliable. In this communication, we are shedding more light on the contamination and radiation issues, which are the most common causes for optical damages and laser failures in space. At first, we will present results based on the study of liquids and subsequently correlate these results to the particulates of the laser system environment. We present a model explaining how the laser beam traps contaminants against the optical surfaces and cause optical damages and the role of gravity in the process. We also report the results of the second harmonic generation efficiency for nonlinear optical crystals irradiated with high-energy beams of protons. In addition, we are proposing to employ the technique of adsorption to minimize the presence of adsorbing molecules present in the laser compartment.
European standardization for the management of space-related projects
Directory of Open Access Journals (Sweden)
Teresa IDZIKOWSKA
2017-06-01
Full Text Available A project is a temporary endeavour designed to produce a unique product, service or result, with a defined beginning and end (usually constrained by time, funding or deliverables, which is undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value. Space projects involve a complex process and usually take many years to be developed. The development of complex project requires the cooperation of several organizations, which share a common goal: namely, to create a product that satisfies the consumer’s needs (technical performance within cost and schedule constraints. To reach this goal, corresponding technical activities, as well as human and financial resources, need to be organized and coordinated in a wellorganized manner. Project management is the discipline of initiating, planning, executing, controlling, and finalizing the work of a team in the achievement of specific goals and meeting specific success criteria. This involves the application of knowledge, skills, tools, and techniques to project activities in order to meet project requirements. The paper is a review of how issues related to space management requirements has been addressed in Europe.
Energy Technology Data Exchange (ETDEWEB)
Chekhov, L.O.
1985-12-01
Matrix nonlinear sigma models are discussed and the matrix nonlinear sigma model in the case of N x ..cap alpha..N rectangular matrices is considered. The authors show that in two-dimensional Euclidean space, the model is renormalizable with respect to ..cap alpha.. and 1/N. The fulfillment of the chirality identity is demonstrated in the operator expansion for the renormalized theory.
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
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
Huffaker, Ray; Bittelli, Marco
2015-01-01
Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind-the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns.
A Neurodynamic Model to Solve Nonlinear Pseudo-Monotone Projection Equation and Its Applications.
Eshaghnezhad, Mohammad; Effati, Sohrab; Mansoori, Amin
2016-09-29
In this paper, a neurodynamic model is given to solve nonlinear pseudo-monotone projection equation. Under pseudo-monotonicity condition and Lipschitz continuous condition, the projection neurodynamic model is proved to be stable in the sense of Lyapunov, globally convergent, globally asymptotically stable, and globally exponentially stable. Also, we show that, our new neurodynamic model is effective to solve the nonconvex optimization problems. Moreover, since monotonicity is a special case of pseudo-monotonicity and also since a co-coercive mapping is Lipschitz continuous and monotone, and a strongly pseudo-monotone mapping is pseudo-monotone, the neurodynamic model can be applied to solve a broader classes of constrained optimization problems related to variational inequalities, pseudo-convex optimization problem, linear and nonlinear complementarity problems, and linear and convex quadratic programming problems. Finally, several illustrative examples are stated to demonstrate the effectiveness and efficiency of our new neurodynamic model.
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.
A Space-Time Finite Element Model for Design and Control Optimization of Nonlinear Dynamic Response
Directory of Open Access Journals (Sweden)
P.P. Moita
2008-01-01
Full Text Available A design and control sensitivity analysis and multicriteria optimization formulation is derived for flexible mechanical systems. This formulation is implemented in an optimum design code and it is applied to the nonlinear dynamic response. By extending the spatial domain to the space-time domain and treating the design variables as control variables that do not change with time, the design space is included in the control space. Thus, one can unify in one single formulation the problems of optimum design and optimal control. Structural dimensions as well as lumped damping and stiffness parameters plus control driven forces, are considered as decision variables. The dynamic response and its sensitivity with respect to the design and control variables are discretized via space-time finite elements, and are integrated at-once, as it is traditionally used for static response. The adjoint system approach is used to determine the design sensitivities. Design optimization numerical examples are performed. Nonlinear programming and optimality criteria may be used for the optimization process. A normalized weighted bound formulation is used to handle multicriteria problems.
Salient region detection Using Wasserstein distance measure based on nonlinear scale space
Zhu, Lei; Cao, Zhiguo
2013-10-01
Many existing bottom-up saliency detection methods measure the multi-scale local prominence by building the Gaussian scale space. As a kind of linear scale space, it is a natural representation of human perception. However the Gaussian filtering does not respect the boundaries of proto-objects and smooth both noises and details. In this paper, we compute the pixel level center-surround difference in a nonlinear scale space which makes blurring locally adaptive to the image regions. The nonlinear scale space is built by a efficient evolution techniques and extended to represent color images. In contrast to some widely used region-based measures, we represent feature statistics by multivariate normal distributions and compare them with the Wasserstein distance on l2 norm (W2 distance). From the perspective of visual organization in imaging, many priors are proved to be efficient in global consideration. In order to further precisely locate the proper salient object, we also use the background prior as a global cue to refine the obtained local saliency map. The experimental results show that our approach outperforms 5 recent state of the art saliency detection methods in terms of precision and recall on a newly published benchmark.
The NASA OCEAN project--an ocean-space analog
Chamberland, D
1996-01-01
An advanced life support system (ALS) with bioregenerative components may one day be required for long-term, deep space exploration, in extended missions to Mars or in establishing long-term bases on the moon. Intensive research programs on such ALS systems have been ongoing throughout the National Aeronautics and Space Administration (NASA) since 1988. Notably, projects have been initiated at the John F. Kennedy Space Center (KSC), Ames Research Center (ARC), and the Lyndon B. Johnson Space Center (JSC). The KSC ALS work has been named the "Breadboard Project" because of its approach developing the components and combining them into a breadboard to understanding the bioregenerative ALS picture [also called a Controlled Ecological Life Support System (CELSS)] in smaller pieces, similar to an electronic "breadboard." The Breadboard Project has been involved for 7 years in the study of higher crops grown in a 113 m3 chamber--the longest operating and largest such closed, controlled growth chamber in the world. This chamber has proven itself to be very successful in growing a wide variety of crops from seedlings to harvest and in helping researchers understand the complex biological cycle of such edible plants in closed, environmentally controlled environments. Because the system's ultimate use will be a more challenging environment, moving a specially designed piece of the system into extreme conditions was an important test. Engineers at KSC developed a compact, portable, functional plant module for testing in the world's only fixed seafloor laboratory at Key Largo, FL. The laboratory, called MarineLab, is operated out of the facilities of the Marine Resources Development Foundation in a lagoon of some 10 m depth. The project was called the OCEAN project (Ocean CELSS Experimental Analog NASA).
Geng, Lingling; Yu, Yongguang; Zhang, Shuo
2016-09-01
In this paper, the function projective synchronization between integer-order and stochastic fractional-order nonlinear systems is investigated. Firstly, according to the stability theory of fractional-order systems and tracking control, a controller is designed. At the same time, based on the orthogonal polynomial approximation, the method of transforming stochastic error system into an equivalent deterministic system is given. Thus, the stability of the stochastic error system can be analyzed through its equivalent deterministic one. Finally, to demonstrate the effectiveness of the proposed scheme, the function projective synchronization between integer-order Lorenz system and stochastic fractional-order Chen system is studied.
Generalized projective synchronization in time-delayed systems: nonlinear observer approach.
Ghosh, Dibakar
2009-03-01
In this paper, we consider the projective-anticipating, projective, and projective-lag synchronization in a unified coupled time-delay system via nonlinear observer design. A new sufficient condition for generalized projective synchronization is derived analytically with the help of Krasovskii-Lyapunov theory for constant and variable time-delay systems. The analytical treatment can give stable synchronization (anticipatory and lag) for a large class of time-delayed systems in which the response system's trajectory is forced to have an amplitude proportional to the drive system. The constant of proportionality is determined by the control law, not by the initial conditions. The proposed technique has been applied to synchronize Ikeda and prototype models by numerical simulation.
Variational principle and a perturbative solution of non-linear string equations in curved space
Roshchupkin, S N
1999-01-01
String dynamics in a curved space-time is studied on the basis of an action functional including a small parameter of rescaled tension constant. A rescaled slow worldsheet time $T=\\epsilon\\tau$ is introduced, and general covariant non-linear string equation are derived. It is shown that in the first order of an $\\epsilon $-expansion these equations are reduced to the known equation for geodesic derivation but complemented by a string oscillatory term. These equations are solved for the de Sitter and Friedmann -Robertson-Walker spaces. The primary string constraints are found to be split into a chain of perturbative constraints and their conservation and consistency are proved. It is established that in the proposed realization of the perturbative approach the string dynamics in the de Sitter space is stable for a large Hubble constant $H
Miksovsky, J.; Raidl, A.
Time delays phase space reconstruction represents one of useful tools of nonlinear time series analysis, enabling number of applications. Its utilization requires the value of time delay to be known, as well as the value of embedding dimension. There are sev- eral methods how to estimate both these parameters. Typically, time delay is computed first, followed by embedding dimension. Our presented approach is slightly different - we reconstructed phase space for various combinations of mentioned parameters and used it for prediction by means of the nearest neighbours in the phase space. Then some measure of prediction's success was computed (correlation or RMSE, e.g.). The position of its global maximum (minimum) should indicate the suitable combination of time delay and embedding dimension. Several meteorological (particularly clima- tological) time series were used for the computations. We have also created a MS- Windows based program in order to implement this approach - its basic features will be presented as well.
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.
Finite Element Solutions for the Space Fractional Diffusion Equation with a Nonlinear Source Term
Directory of Open Access Journals (Sweden)
Y. J. Choi
2012-01-01
Full Text Available We consider finite element Galerkin solutions for the space fractional diffusion equation with a nonlinear source term. Existence, stability, and order of convergence of approximate solutions for the backward Euler fully discrete scheme have been discussed as well as for the semidiscrete scheme. The analytical convergent orders are obtained as O(k+hγ˜, where γ˜ is a constant depending on the order of fractional derivative. Numerical computations are presented, which confirm the theoretical results when the equation has a linear source term. When the equation has a nonlinear source term, numerical results show that the diffusivity depends on the order of fractional derivative as we expect.
Nonlinear Superconducting Metamaterials in Free-Space at mm-wave Frequencies
Anlage, Steven; Zhang, Daimeng; Trepanier, Melissa; Mukhanov, Oleg; Delfanazari, K.; Savinov, V.; Zheludev, N.
2014-03-01
Superconducting metamaterials show the promise of low loss, compact size and extreme tunability and nonlinearity, allowing for new applications. Most demonstrations of these metamaterials have been conducted in waveguide geometries, either in co-planar form or three-dimensional single-conductor structures. Here we demonstrate for the first time a widely tunable superconducting metamaterial operating under the free-space illumination of a quasi-optical beam in the 100 GHz regime. The meta-atoms are Radio Frequency Superconducting QUantum Interference Devices (RF SQUIDs) that form compact self-resonant objects endowed with the nonlinearity of the Josephson effect. The metamaterial is tuned with dc magnetic flux, temperature and mm-wave power, and holds promise for a new generation of mm-wave agile devices. This work is supported by the NSF-GOALI and OISE programs through grant # ECCS-1158644, and CNAM.
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
Pan, Shuokai; Elliott, Stephen J; Teal, Paul D; Lineton, Ben
2015-06-01
Nonlinear models of the cochlea are best implemented in the time domain, but their computational demands usually limit the duration of the simulations that can reasonably be performed. This letter presents a modified state space method and its application to an example nonlinear one-dimensional transmission-line cochlear model. The sparsity pattern of the individual matrices for this alternative formulation allows the use of significantly faster numerical algorithms. Combined with a more efficient implementation of the saturating nonlinearity, the computational speed of this modified state space method is more than 40 times faster than that of the original formulation.
Manned Space Flight Project Ready to Start the Second Stage
Institute of Scientific and Technical Information of China (English)
LiuJie
2004-01-01
China Aerospace Science and Technology Corporation (CASC) made four launches from October 15 to November 15 in 2003, The successful launches made in such short time have proved the ability of the Chinese engineers, technology level and management skills. Especially China's first manned mission achieved a complete success, which indicates that the first step of China's manned space flight project has already been completed and the conditions for the second step is mature.
RECENT PROGRESS IN THE PROJECT OF SPACE SOLAR TELESCOPE
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
In this paper, we introduce some process of the project of Space Solar Telescope in recent two years. The astronomic requirements have been further identified,the mission and operation requirements have been assessed, and some critical technologies have been performed. According to the time schedule, it is esti mated that the engineering model of the spacecraft would be completed and put into test operation in the end of 2004 and the spacecraft would be launched in about 2007.
Projective Limits of State Spaces IV. Fractal Label Sets
Lanéry, Suzanne
2015-01-01
Instead of formulating the state space of a quantum field theory over one big Hilbert space, it has been proposed by Kijowski [Kijowski 1977] to represent quantum states as projective families of density matrices over a collection of smaller, simpler Hilbert spaces. 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 w...
Topological complexity of motion planning in projective product spaces
Gonzalez, Jesus; Torres-Giese, Enrique; Xicotencatl, Miguel
2012-01-01
We study Farber's topological complexity (TC) of Davis' projective product spaces (PPS's). We show that, in many non-trivial instances, the TC of PPS's coming from at least two sphere factors is (much) lower than the dimension of the manifold. This is in high contrast with the known situation for (usual) real projective spaces for which, in fact, the Euclidean immersion dimension and TC are two facets of the same problem. Low TC-values have been observed for infinite families of non-simply connected spaces only for H-spaces, for finite complexes whose fundamental group has cohomological dimension not exceeding 2, and now in this work for infinite families of PPS's. We discuss general bounds for the TC (and the Lusternik-Schnirelmann category) of PPS's, and compute these invariants for specific families of such manifolds. Some of our methods involve the use of an equivariant version of TC. We also give a characterization of the Euclidean immersion dimension of PPS's through generalized concepts of axial maps a...
National Aeronautics and Space Administration — SSCI proposes to develop and test a framework referred to as the ADVANCE (Algorithm Design and Validation for Adaptive Nonlinear Control Enhancement), within which...
National Aeronautics and Space Administration — Techsburg is teaming with the Vibration and Acoustics Laboratory of Virginia Tech to propose a non-linear analytical tool for designing Herschel-Quincke (HQ)...
National Aeronautics and Space Administration — A ferroelectric non-linear dielectric was recently discovered that, in their film form, possess a number of properties that make it an excellent choice for...
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.
Directory of Open Access Journals (Sweden)
Emad A.-B. Abdel-Salam
2013-01-01
Full Text Available The fractional Riccati expansion method is proposed to solve fractional differential equations. To illustrate the effectiveness of the method, space-time fractional Korteweg-de Vries equation, regularized long-wave equation, Boussinesq equation, and Klein-Gordon equation are considered. As a result, abundant types of exact analytical solutions are obtained. These solutions include generalized trigonometric and hyperbolic functions solutions which may be useful for further understanding of the mechanisms of the complicated nonlinear physical phenomena and fractional differential equations. Among these solutions, some are found for the first time. The periodic and kink solutions are founded as special case.
Existence of Solutions to Nonlinear Impulsive Volterra Integral Equations in Banach Spaces
Institute of Scientific and Technical Information of China (English)
CHEN Fangqi; TIAN Ruilan
2005-01-01
In this paper, the existence of solutions is studied for nonlinear impulsive Volterra integral equations with infinite moments of impulse effect on the half line R+ in Banach spaces.By the use of a new comparison result and recurrence method, the new existence theorems are achieved under a weaker compactness-type condition, which generalize and improve the related results for this class of equations with finite moments of impulse effect on finite interval and infinite moments of impulse effect on infinite interval.
Panoramic Stereoscopic Video System for Remote-Controlled Robotic Space Operations Project
National Aeronautics and Space Administration — This Phase I project will demonstrate the feasibility of providing panoramic stereoscopic images for remote-controlled robotic space operations using three...
Sarhadi, Ali; Burn, Donald H.; Yang, Ge; Ghodsi, Ali
2017-02-01
One of the main challenges in climate change studies is accurate projection of the global warming impacts on the probabilistic behaviour of hydro-climate processes. Due to the complexity of climate-associated processes, identification of predictor variables from high dimensional atmospheric variables is considered a key factor for improvement of climate change projections in statistical downscaling approaches. For this purpose, the present paper adopts a new approach of supervised dimensionality reduction, which is called "Supervised Principal Component Analysis (Supervised PCA)" to regression-based statistical downscaling. This method is a generalization of PCA, extracting a sequence of principal components of atmospheric variables, which have maximal dependence on the response hydro-climate variable. To capture the nonlinear variability between hydro-climatic response variables and projectors, a kernelized version of Supervised PCA is also applied for nonlinear dimensionality reduction. The effectiveness of the Supervised PCA methods in comparison with some state-of-the-art algorithms for dimensionality reduction is evaluated in relation to the statistical downscaling process of precipitation in a specific site using two soft computing nonlinear machine learning methods, Support Vector Regression and Relevance Vector Machine. The results demonstrate a significant improvement over Supervised PCA methods in terms of performance accuracy.
Inferring gene regulatory networks via nonlinear state-space models and exploiting sparsity.
Noor, Amina; Serpedin, Erchin; Nounou, Mohamed; Nounou, Hazem N
2012-01-01
This paper considers the problem of learning the structure of gene regulatory networks from gene expression time series data. A more realistic scenario when the state space model representing a gene network evolves nonlinearly is considered while a linear model is assumed for the microarray data. To capture the nonlinearity, a particle filter-based state estimation algorithm is considered instead of the contemporary linear approximation-based approaches. The parameters characterizing the regulatory relations among various genes are estimated online using a Kalman filter. Since a particular gene interacts with a few other genes only, the parameter vector is expected to be sparse. The state estimates delivered by the particle filter and the observed microarray data are then subjected to a LASSO-based least squares regression operation which yields a parsimonious and efficient description of the regulatory network by setting the irrelevant coefficients to zero. The performance of the aforementioned algorithm is compared with the extended Kalman filter (EKF) and Unscented Kalman Filter (UKF) employing the Mean Square Error (MSE) as the fidelity criterion in recovering the parameters of gene regulatory networks from synthetic data and real biological data. Extensive computer simulations illustrate that the proposed particle filter-based network inference algorithm outperforms EKF and UKF, and therefore, it can serve as a natural framework for modeling gene regulatory networks with nonlinear and sparse structure.
Interferometric and nonlinear-optical spectral-imaging techniques for outer space and live cells
Itoh, Kazuyoshi
2015-12-01
Multidimensional signals such as the spectral images allow us to have deeper insights into the natures of objects. In this paper the spectral imaging techniques that are based on optical interferometry and nonlinear optics are presented. The interferometric imaging technique is based on the unified theory of Van Cittert-Zernike and Wiener-Khintchine theorems and allows us to retrieve a spectral image of an object in the far zone from the 3D spatial coherence function. The retrieval principle is explained using a very simple object. The promising applications to space interferometers for astronomy that are currently in progress will also be briefly touched on. An interesting extension of interferometric spectral imaging is a 3D and spectral imaging technique that records 4D information of objects where the 3D and spectral information is retrieved from the cross-spectral density function of optical field. The 3D imaging is realized via the numerical inverse propagation of the cross-spectral density. A few techniques suggested recently are introduced. The nonlinear optical technique that utilizes stimulated Raman scattering (SRS) for spectral imaging of biomedical targets is presented lastly. The strong signals of SRS permit us to get vibrational information of molecules in the live cell or tissue in real time. The vibrational information of unstained or unlabeled molecules is crucial especially for medical applications. The 3D information due to the optical nonlinearity is also the attractive feature of SRS spectral microscopy.
Some results of a nodal method for nonlinear space-time reactor dynamics
Energy Technology Data Exchange (ETDEWEB)
Le, T.T. (Westinghouse Savannah River Co., Aiken, SC (United States)); Grossman, L.M. (California Univ., Berkeley, CA (United States). Dept. of Nuclear Engineering)
1991-01-01
There are many reports about nodal methods for static and dynamic problems, but not many for the nonlinear feedback cases. In this paper, a class of nodal methods called mathematical nodal method'' (MNM) is studied with the temperature feedback problems. The spatially complex domain of the problem is represented as a collection of geometrically simple subdomains of the size of fuel assemblies called nodes. Over each node, the time dependent coefficients of the neutron flux, precursor concentrations, fuel and coolant temperatures are the surface and volume weighted average (moment) values of the unknown solutions; the space dependent basis functions are a combination of Legendre polynomials. If the material parameters are a linear function of fuel and coolant temperatures, the coupled equations can be put in a dimensionless form and a system of time dependent ordinary differential equations containing nonlinear feedback terms is obtained. These nonlinear feedback terms are updated at each time step during the time iteration process. Results of some benchmark problems are included in this report.
Some results of a nodal method for nonlinear space-time reactor dynamics
Energy Technology Data Exchange (ETDEWEB)
Le, T.T. [Westinghouse Savannah River Co., Aiken, SC (United States); Grossman, L.M. [California Univ., Berkeley, CA (United States). Dept. of Nuclear Engineering
1991-12-31
There are many reports about nodal methods for static and dynamic problems, but not many for the nonlinear feedback cases. In this paper, a class of nodal methods called ``mathematical nodal method`` (MNM) is studied with the temperature feedback problems. The spatially complex domain of the problem is represented as a collection of geometrically simple subdomains of the size of fuel assemblies called nodes. Over each node, the time dependent coefficients of the neutron flux, precursor concentrations, fuel and coolant temperatures are the surface and volume weighted average (moment) values of the unknown solutions; the space dependent basis functions are a combination of Legendre polynomials. If the material parameters are a linear function of fuel and coolant temperatures, the coupled equations can be put in a dimensionless form and a system of time dependent ordinary differential equations containing nonlinear feedback terms is obtained. These nonlinear feedback terms are updated at each time step during the time iteration process. Results of some benchmark problems are included in this report.
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
New Space Weather and Nonlinear Waves and Processes Prize announced for 2013
Thompson, Victoria
2012-01-01
At the 2011 Fall Meeting in San Francisco, Calif., AGU announced the creation of a new award: the Space Weather and Nonlinear Waves and Processes Prize. The prize, which is being made possible by a generous contribution from longtime AGU members and NASA Jet Propulsion Laboratory (JPL), California Institute of Technology, scientists Bruce Tsurutani and Olga Verkhoglyadova, will recognize an AGU member scientist and will come with a $10,000 award. Tsurutani has served as a researcher with JPL since 1972 and is currently a senior research scientist. He was also the president of AGU's Space Physics and Aeronomy section from 1990 to 1992 and is a recipient of AGU's John Adam Fleming Medal, given “for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences.” Verkhoglyadova served as a professor of space physics in the Department of Astrophysics and Space Physics at Taras Shevchenko National University of Kyiv, in the Ukraine, prior to coming to the United States. Their leadership and dedication to AGU and to their field are apparent in their passion for this prize.
Directory of Open Access Journals (Sweden)
Ray Huffaker
Full Text Available Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A. to sites with lower-average speeds (such as the Southeast U.S.A. by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind-the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns.
Johnston, D. W. H.
1981-01-01
The increasing density of electrical and electronic circuits in Deep Space Station systems for computation, control, and numerous related functions has combined with the extension of system performance requirements calling for higher speed circuitry along with broader bandwidths. This has progressively increased the number of potential sources of radio frequency interference inside the stations. Also, the extension of spectrum usage both in power and frequency as well as the greater density of usage at all frequencies for national and international satellite communications, space research, Earth resource operations and defense, and particularly the huge expansion of airborne electronic warfare and electronic countermeasures operations in the Mojave area have greatly increased the potential number and severity of radio frequency interference incidents. The various facets of this problem and the efforts to eliminate or minimize the impact of interference on Deep Space Network support of deep space flight projects are described.
Nonlinear model of space manipulator joint considering time-variant stiffness and backlash
Yang, Tianfu; Yan, Shaoze; Han, Zengyao
2015-04-01
Modeling of space manipulator joints has been studied for years but accurate positioning control is still unsatisfactory. One of the primary reasons is that, in the past researches, effects of the high-ratio reducers in the joints have usually been neglected. In this paper, a nonlinear dynamic model of the manipulator joint with planetary gear train transmission is developed by considering time-variant joint stiffness, backlash and reduction ratio. Based on the gear parameters and meshing phase relationship, the stiffness of the joint model is presented, in which the time-variant stiffness of 2K-H planetary gear train and the backlash are taken into consideration. The backlash effect is modeled as an alternate engagement mechanism, and the transmitted torque is defined as a dead zone function. This model is simulated on a two-link space manipulator system. The results show that the time-variant stiffness effect can be simplified as a constant value in most cases when other shafting parts are flexible, while if the total stiffness is approximate to the nonlinear stiffness, the positioning accuracy is reduced if neglecting the time-variant part. On the other hand, the backlash is the main source of positioning error and impact. Minimizing backlash is the most effective way to improve positioning accuracy and avoid the impact in the gearing system.
The Lazarus Project II: Space-like extraction with the Quasi-Kinnersley tetrad
Campanelli, Manuela; Kelly, Bernard; Lousto, Carlos
2006-04-01
The Lazarus project was designed to make the most of limited 3D binary black-hole simulations, through the identification of perturbations at late times, and subsequent evolution of the Weyl scalar ψ4 via the Teukolsky formulation. Here we report on new developments, employing the concept of the ``quasi-Kinnersley'' (transverse) frame, valid in the full nonlinear regime, to analyze late-time numerical space-times that should differ only slightly from Kerr. This allows us to extract the essential information about the background Kerr solution, and through this, to identify the radiation present. We explicitly test this procedure with full numerical evolutions of Bowen-York data for single spinning black holes, head-on and orbiting black holes near the ISCO regime. These techniques validate previous Lazarus results, provide a measure of the errors intrinsic to the method, and give as a by-product a more robust wave extraction method for numerical relativity.
The Lazarus Project II: Space-like extraction with the Quasi-Kinnersley tetrad
Campanelli, M; Loustó, C O; Campanelli, Manuela; Kelly, Bernard J.; Lousto, Carlos O.
2006-01-01
The Lazarus project was designed to make the most of limited 3D binary black-hole simulations, through the identification of perturbations at late times, and subsequent evolution of the Weyl scalar $\\Psi_4$ via the Teukolsky formulation. Here we report on new developments, employing the concept of the ``quasi-Kinnersley'' (transverse) frame, valid in the full nonlinear regime, to analyze late-time numerical space-times that should differ only slightly from Kerr. This allows us to extract the essential information about the background Kerr solution, and through this, to identify the radiation present. We explicitly test this procedure with full numerical evolutions of Bowen-York data for single spinning black holes, head-on and orbiting black holes near the ISCO regime. These techniques validate previous Lazarus results, provide a measure of the errors intrinsic to the method, and give as a by-product a more robust wave extraction method for numerical relativity.
A Projected Non-linear Conjugate Gradient Method for Interactive Inverse Kinematics
DEFF Research Database (Denmark)
Engell-Nørregård, Morten; Erleben, Kenny
2009-01-01
Inverse kinematics is the problem of posing an articulated figure to obtain a wanted goal, without regarding inertia and forces. Joint limits are modeled as bounds on individual degrees of freedom, leading to a box-constrained optimization problem. We present A projected Non-linear Conjugate...... Gradient optimization method suitable for box-constrained optimization problems for inverse kinematics. We show application on inverse kinematics positioning of a human figure. Performance is measured and compared to a traditional Jacobian Transpose method. Visual quality of the developed method...
A non-linear model predictive controller with obstacle avoidance for a space robot
Wang, Mingming; Luo, Jianjun; Walter, Ulrich
2016-04-01
This study investigates the use of the non-linear model predictive control (NMPC) strategy for a kinematically redundant space robot to approach an un-cooperative target in complex space environment. Collision avoidance, traditionally treated as a high level planning problem, can be effectively translated into control constraints as part of the NMPC. The objective of this paper is to evaluate the performance of the predictive controller in a constrained workspace and to investigate the feasibility of imposing additional constraints into the NMPC. In this paper, we reformulated the issue of the space robot motion control by using NMPC with predefined objectives under input, output and obstacle constraints over a receding horizon. An on-line quadratic programming (QP) procedure is employed to obtain the constrained optimal control decisions in real-time. This study has been implemented for a 7 degree-of-freedom (DOF) kinematically redundant manipulator mounted on a 6 DOF free-floating spacecraft via simulation studies. Real-time trajectory tracking and collision avoidance particularly demonstrate the effectiveness and potential of the proposed NMPC strategy for the space robot.
The Space Optical Clock project: status and perspectives
Schiller, Stephan; Tino, Guglielmo M.; Sterr, Uwe; Lemonde, Pierre; Görlitz, Axel; Salomon, Christophe
The Space Optical Clocks project aims at operating lattice clocks on the ISS for tests of funda-mental physics and for providing high-accuracy comparisons of future terrestrial optical clocks. A pre-phase-A study (2007-10), funded partially by ESA and DLR, includes the implementa-tion of several optical lattice clock systems using Strontium and Ytterbium as atomic systems and their characterization. Subcomponents of clock demonstrators with the added specification of transportability and using techniques that are suitable for later space use, such as all-solid-state lasers, low power consumption, and compact dimensions, have been developed and are being validated. The talk will give a brief overview over the achieved results and outline future developments.
The read-out ASIC for the Space NUCLEON project
Atkin, E.; Voronin, A.; Karmanov, D.; Kudryashov, I.; Podorozhniy, D.; Shumikhin, V.
2015-04-01
This paper summarizes the design results for the read-out ASIC for the space NUCLEON project of the Russian Federal Space Agency ROSCOSMOS. The ASIC with a unique high dynamic range (1-40 000 mip) at low power consumption ( 50, generated by silicon detectors, having capacitances up to 100 pF. The chip structure includes 32 analog channels, each consisting of a charge sensitive amplifier (CSA) with a p-MOS input transistor (W = 8 mm, L = 0.5 μ m), a shaper (peaking time of 2 us) and a T&H circuit. The ASIC showed a 120 pC dynamic range at a SNR of 2.5 for the particles with minimal ionization energy (1 mip). The chip was fabricated by the 0.35 um CMOS process via Europractice and tested both at lab conditions and in the SPS beam at CERN.
Institute of Scientific and Technical Information of China (English)
Lu Jun
2004-01-01
The stationary-state nonlinear Schr(o)dinger equation, which models the dilute-gas Bose-Einstein condensate, is introduced within the framework of the quantum phase-space representation established by Torres-Vega and Frederick.The exact solutions of equation are obtained in the phase space, by means of the wave-mechanics method. The the phase space eigenfunctions. The eigenfunction with a hypersecant part is discussed as an example.
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.; Stone, L. S.
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
Linear and nonlinear associations between general intelligence and personality in Project TALENT.
Major, Jason T; Johnson, Wendy; Deary, Ian J
2014-04-01
Research on the relations of personality traits to intelligence has primarily been concerned with linear associations. Yet, there are no a priori reasons why linear relations should be expected over nonlinear ones, which represent a much larger set of all possible associations. Using 2 techniques, quadratic and generalized additive models, we tested for linear and nonlinear associations of general intelligence (g) with 10 personality scales from Project TALENT (PT), a nationally representative sample of approximately 400,000 American high school students from 1960, divided into 4 grade samples (Flanagan et al., 1962). We departed from previous studies, including one with PT (Reeve, Meyer, & Bonaccio, 2006), by modeling latent quadratic effects directly, controlling the influence of the common factor in the personality scales, and assuming a direction of effect from g to personality. On the basis of the literature, we made 17 directional hypotheses for the linear and quadratic associations. Of these, 53% were supported in all 4 male grades and 58% in all 4 female grades. Quadratic associations explained substantive variance above and beyond linear effects (mean R² between 1.8% and 3.6%) for Sociability, Maturity, Vigor, and Leadership in males and Sociability, Maturity, and Tidiness in females; linear associations were predominant for other traits. We discuss how suited current theories of the personality-intelligence interface are to explain these associations, and how research on intellectually gifted samples may provide a unique way of understanding them. We conclude that nonlinear models can provide incremental detail regarding personality and intelligence associations.
HIgh Efficiency Laser for Aircraft/UAV and Space Lidar Missions Project
National Aeronautics and Space Administration — This SBIR will develop advanced, high-efficiency, high beam-quality solid-state laser technology and non-linear wavelength conversion technology suitable for Ozone,...
HIgh Efficiency Laser for Aircraft/UAV and Space Lidar Missions Project
National Aeronautics and Space Administration — This SBIR is developing high-efficiency, high beam-quality Nd lasers and non-linear wavelength conversion technologies suitable for ozone, aerosol, oxygen, CO2,...
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.
Tsurutani, Bruce T.
1995-01-01
As the lead-off presentation for the topic of nonlinear waves and their evolution, we will illustrate some prominent examples of waves in space plasmas. We will describe recent observations detected within planetary foreshocks, near comets and in interplanetary space. It is believed that the nonlinear LF plasma wave features discussed here are part of and may be basic to the development of plasma turbulence. In this sense, this is one area of space plasma physics that is fundamental, with applications to fusion physics and astrophysics as well. It is hoped that the reader(s) will be stimulated to study nonlinear wave development themselves, if he/she is not already involved.
Yang, Haijian
2016-07-26
Fully implicit methods are drawing more attention in scientific and engineering applications due to the allowance of large time steps in extreme-scale simulations. When using a fully implicit method to solve two-phase flow problems in porous media, one major challenge is the solution of the resultant nonlinear system at each time step. To solve such nonlinear systems, traditional nonlinear iterative methods, such as the class of the Newton methods, often fail to achieve the desired convergent rate due to the high nonlinearity of the system and/or the violation of the boundedness requirement of the saturation. In the paper, we reformulate the two-phase model as a variational inequality that naturally ensures the physical feasibility of the saturation variable. The variational inequality is then solved by an active-set reduced-space method with a nonlinear elimination preconditioner to remove the high nonlinear components that often causes the failure of the nonlinear iteration for convergence. To validate the effectiveness of the proposed method, we compare it with the classical implicit pressure-explicit saturation method for two-phase flow problems with strong heterogeneity. The numerical results show that our nonlinear solver overcomes the often severe limits on the time step associated with existing methods, results in superior convergence performance, and achieves reduction in the total computing time by more than one order of magnitude.
Experiments in Nonlinear Adaptive Control of Multi-Manipulator, Free-Flying Space Robots
Chen, Vincent Wei-Kang
1992-01-01
Sophisticated robots can greatly enhance the role of humans in space by relieving astronauts of low level, tedious assembly and maintenance chores and allowing them to concentrate on higher level tasks. Robots and astronauts can work together efficiently, as a team; but the robot must be capable of accomplishing complex operations and yet be easy to use. Multiple cooperating manipulators are essential to dexterity and can broaden greatly the types of activities the robot can achieve; adding adaptive control can ease greatly robot usage by allowing the robot to change its own controller actions, without human intervention, in response to changes in its environment. Previous work in the Aerospace Robotics Laboratory (ARL) have shown the usefulness of a space robot with cooperating manipulators. The research presented in this dissertation extends that work by adding adaptive control. To help achieve this high level of robot sophistication, this research made several advances to the field of nonlinear adaptive control of robotic systems. A nonlinear adaptive control algorithm developed originally for control of robots, but requiring joint positions as inputs, was extended here to handle the much more general case of manipulator endpoint-position commands. A new system modelling technique, called system concatenation was developed to simplify the generation of a system model for complicated systems, such as a free-flying multiple-manipulator robot system. Finally, the task-space concept was introduced wherein the operator's inputs specify only the robot's task. The robot's subsequent autonomous performance of each task still involves, of course, endpoint positions and joint configurations as subsets. The combination of these developments resulted in a new adaptive control framework that is capable of continuously providing full adaptation capability to the complex space-robot system in all modes of operation. The new adaptive control algorithm easily handles free
Energy Technology Data Exchange (ETDEWEB)
Belmonte-Beitia, J [Departamento de Matematicas, E T S de Ingenieros Industriales and Instituto de Matematica Aplicada a la Ciencia y la IngenierIa (IMACI), Avda Camilo Jose Cela, 3 Universidad de Castilla-La Mancha 13071 Ciudad Real (Spain); Cuevas, J [Grupo de Fisica No Lineal, Departamento de Fisica Aplicada I, Escuela Universitaria Politecnica, C/Virgen de Africa, 7, 41011 Sevilla (Spain)], E-mail: juan.belmonte@uclm.es, E-mail: jcuevas@us.es
2009-04-24
In this paper, we construct, by means of similarity transformations, explicit solutions to the cubic-quintic nonlinear Schroedinger equation with potentials and nonlinearities depending on both time and spatial coordinates. We present the general approach and use it to calculate bright and dark soliton solutions for nonlinearities and potentials of physical interest in applications to Bose-Einstein condensates and nonlinear optics.
A Space-time Smooth Artificial Viscosity Method For Nonlinear Conservation Laws
Reisner, Jon; Shkoller, Steve
2012-01-01
We introduce the $C$-method, a simple scheme for adding localized, space-time smooth, artificial viscosity to nonlinear systems of conservation laws which propagate shock waves, rarefactions, and contact discontinuities. In particular, we focus our attention on the compressible Euler equations which form a 3x3 system in one space dimension. The novel feature of our approach involves the coupling of a linear scalar reaction diffusion equation to our system of conservation laws, whose solution $C(x,t)$ is the coefficient to an additional (and artificial) term added to the flux, which determines both the location and strength of the added viscosity. Near shock discontinuities, $C(x,t)$ is large and localized, and transitions smoothly in space-time to zero away from the shock. This simple approach has two fundamental features: (1) our regularization is at the continuum level--i.e., the level of he partial differential equations (PDE)-- so that any higher-order numerical discretization scheme can be employed, and ...
Niemi, Jarad; West, Mike
2010-06-01
We describe a strategy for Markov chain Monte Carlo analysis of non-linear, non-Gaussian state-space models involving batch analysis for inference on dynamic, latent state variables and fixed model parameters. The key innovation is a Metropolis-Hastings method for the time series of state variables based on sequential approximation of filtering and smoothing densities using normal mixtures. These mixtures are propagated through the non-linearities using an accurate, local mixture approximation method, and we use a regenerating procedure to deal with potential degeneracy of mixture components. This provides accurate, direct approximations to sequential filtering and retrospective smoothing distributions, and hence a useful construction of global Metropolis proposal distributions for simulation of posteriors for the set of states. This analysis is embedded within a Gibbs sampler to include uncertain fixed parameters. We give an example motivated by an application in systems biology. Supplemental materials provide an example based on a stochastic volatility model as well as MATLAB code.
Variational space-time (dis)continuous Galerkin method for nonlinear free surface water waves
Gagarina, E.; Ambati, V. R.; van der Vegt, J. J. W.; Bokhove, O.
2014-10-01
A new variational finite element method is developed for nonlinear free surface gravity water waves using the potential flow approximation. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a finite element discretization that is continuous in space and discontinuous in time. One novel feature of this variational finite element approach is that the free surface evolution is variationally dependent on the mesh deformation vis-à-vis the mesh deformation being geometrically dependent on free surface evolution. Another key feature is the use of a variational (dis)continuous Galerkin finite element discretization in time. Moreover, in the absence of a wave maker, it is shown to be equivalent to the second order symplectic Störmer-Verlet time stepping scheme for the free-surface degrees of freedom. These key features add to the stability of the numerical method. Finally, the resulting numerical scheme is verified against nonlinear analytical solutions with long time simulations and validated against experimental measurements of driven wave solutions in a wave basin of the Maritime Research Institute Netherlands.
Asymptotic behaviour for Schrodinger equations with a quadratic nonlinearity in one-space dimension
Directory of Open Access Journals (Sweden)
Nakao Hayashi
2001-07-01
Full Text Available We consider the Cauchy problem for the Schr"{o}dinger equation with a quadratic nonlinearity in one space dimension $$ iu_{t}+frac{1}{2}u_{xx}=t^{-alpha}| u_x| ^2,quad u(0,x = u_0(x, $$ where $alpha in (0,1$. From the heuristic point of view, solutions to this problem should have a quasilinear character when $alpha in (1/2,1$. We show in this paper that the solutions do not have a quasilinear character for all $alpha in (0,1$ due to the special structure of the nonlinear term. We also prove that for $alpha in [1/2,1$ if the initial data $u_0in H^{3,0}cap H^{2,2}$ are small, then the solution has a slow time decay such as $t^{-alpha /2}$. For $alpha in (0,1/2$, if we assume that the initial data $u_0$ are analytic and small, then the same time decay occurs.
Red'kov, V
2011-01-01
Non-linear electrodynamics arising in the frames of field theories in non-commutative space-time is examined on the base of the Riemann-Silberstein-Majorana-Oppenheimer formalism. The problem of form-invariance of the non-linear constitutive relations governed by six non-commutative parameters \\theta_{kl} \\sim {\\bf K} = {\\bf n} + i {\\bf m} is explored in detail on the base of the complex orthogonal group theory SO(3.C). Two Abelian 2-parametric small groups, isomorphic to each other in abstract sense, and leaving unchangeable the extended constitutive relations at arbitrary six parameters \\theta_{kl} of effective media have been found, their realization depends explicitly on invariant length {\\bf K}^{2}. In the case of non-vanishing length a special reference frame in which the small group has the structure SO(2) \\otimes SO(1,1) has been found. In isotropic case no such reference frame exists. The way to interpret both Abelian small groups in physical terms consists in factorizing corresponding Lorentz transf...
Li, Wan-Tong; Wang, Jia-Bing; Zhang, Li
2016-08-01
This paper is concerned with the new types of entire solutions other than traveling wave solutions of nonlocal dispersal equations with monostable nonlinearity in space periodic habitats. We first establish the existence and properties of spatially periodic solutions connecting two steady states. Then new types of entire solutions are constructed by combining the rightward and leftward pulsating traveling fronts with different speeds and a spatially periodic solution. Finally, for a class of special heterogeneous reaction, we further establish the uniqueness of entire solutions and the continuous dependence of such an entire solution on parameters, such as wave speeds and the shifted variables. In other words, we build a five-dimensional manifold of solutions and the traveling wave solutions are on the boundary of the manifold.
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
Scientific problems addressed by the Spektr-UV space project (world space Observatory—Ultraviolet)
Boyarchuk, A. A.; Shustov, B. M.; Savanov, I. S.; Sachkov, M. E.; Bisikalo, D. V.; Mashonkina, L. I.; Wiebe, D. Z.; Shematovich, V. I.; Shchekinov, Yu. A.; Ryabchikova, T. A.; Chugai, N. N.; Ivanov, P. B.; Voshchinnikov, N. V.; Gomez de Castro, A. I.; Lamzin, S. A.; Piskunov, N.; Ayres, T.; Strassmeier, K. G.; Jeffrey, S.; Zwintz, S. K.; Shulyak, D.; Gérard, J.-C.; Hubert, B.; Fossati, L.; Lammer, H.; Werner, K.; Zhilkin, A. G.; Kaigorodov, P. V.; Sichevskii, S. G.; Ustamuich, S.; Kanev, E. N.; Kil'pio, E. Yu.
2016-01-01
The article presents a review of scientific problems and methods of ultraviolet astronomy, focusing on perspective scientific problems (directions) whose solution requires UV space observatories. These include reionization and the history of star formation in the Universe, searches for dark baryonic matter, physical and chemical processes in the interstellar medium and protoplanetary disks, the physics of accretion and outflows in astrophysical objects, from Active Galactic Nuclei to close binary stars, stellar activity (for both low-mass and high-mass stars), and processes occurring in the atmospheres of both planets in the solar system and exoplanets. Technological progress in UV astronomy achieved in recent years is also considered. The well advanced, international, Russian-led Spektr-UV (World Space Observatory—Ultraviolet) project is described in more detail. This project is directed at creating a major space observatory operational in the ultraviolet (115-310 nm). This observatory will provide an effective, and possibly the only, powerful means of observing in this spectral range over the next ten years, and will be an powerful tool for resolving many topical scientific problems.
Classification of smooth structures on a homotopy complex projective space
Indian Academy of Sciences (India)
Ramesh Kasilingam
2016-05-01
We classify, up to diffeomorphism, all closed smooth manifolds homeomorphic to the complex projective $n$-space ${\\mathbb C}{\\bf P}^n$, where $n = 3$ and 4. Let $M^{2n}$ be a closed smooth $2n$-manifold homotopy equivalent to ${\\mathbb C}{\\bf P}^n$. We show that, up to diffeomorphism, $M^6$ has a unique differentiable structure and $M^8$ has at most two distinct differentiable structures. We also show that, up to concordance, there exist at least two distinct differentiable structures on a finite sheeted cover $N^2n$ of ${\\mathbb C}{\\bf P}^n$ for = 4, 7 or 8 and six distinct differentiable structures on $N^{10}$.
Embedding a Latin square with transversal into a projective space
Pretorius, Lou M
2010-01-01
A Latin square of side n defines in a natural way a finite geometry on 3n points, with three lines of size n and n^2 lines of size 3. A Latin square of side n with a transversal similarly defines a finite geometry on 3n+1 points, with three lines of size n, n^2-n lines of size 3, and n concurrent lines of size 4. A collection of k mutually orthogonal Latin squares defines a geometry on kn points, with k lines of size n and n^2 lines of size k. Extending work of Bruen and Colbourn (J. Combin. Th. Ser. A 92 (2000), 88-94), we characterise embeddings of these finite geometries into projective spaces over skew fields.
Security-Enhanced Autonomous Network Management for Space Networking Project
National Aeronautics and Space Administration — NASA's Space Communications and Navigation (SCaN) program is integrating its three current agency networks: Space Network (SN), Deep Space Network (DSN), and Near...
Wu, Huilan; Yao, Yuqin
2017-01-01
The time- and space-modulated nonlinearity is the important character of the Bose-Einstein condensates (BECs). Many works have been done on atomic BECs with spatially modulated nonlinearity, but there is little work on atomic-molecular BECs. In this paper, we construct one family of explicitly exact solutions of the atomic-molecular BECs with time- and space-modulated nonlinearities and trapping potential by similarity transformations. We discuss the dynamics of matter waves including breathing solitons, quasi-breathing solitons, resonant solitons and moving solitons. We analyze the linear stability of the solutions by adding various initial stochastic noise. We also provide the experimental parameters to produce these phenomena in future experiments.
Tao, Jili; Ma, Longhua; Zhu, Yong
2016-11-01
Inspired by the state space model based predictive control, this paper presents the combination design of extended non-minimal state space predictive control (ENMSSPC) and modified linear quadratic regulator (LQR) for a kind of nonlinear process with output feedback coupling, which shows improved control performance for both model/plant match and model/plant mismatch cases. In many previous control methods for this kind of nonlinear systems, the nonlinear part is treated in different ways such as ignored, represented as a rough linear one or assumed to be time-variant when corresponding predictive control methods are designed. However, the above methods will generally lead to information loss, resulting in the influenced control performance. This paper will show that the ENMSSPC-LQ control structure will further improve closed-loop control performance concerning tracking ability and disturbance rejection compared with previous predictive control methods.
Experimental nonlinear beam dynamics studies with turn- by-turn phase space monitors
Terebilo, Andrei Gennadyevich
1999-10-01
This thesis presents an experimental study of single particle and collective beam dynamics undertaken by the author in SPEAR electron storage ring. The technique used for measurement consists of exciting transverse oscillations of a bunch circulating in the ring with a fast kicker and observing the center of mass oscillations every turn for several thousand turns. The goal of this study was to develop new applications of the turn-by-turn technique to accelerator diagnostics. One innovation introduced is the use of a collective mode of the beam motion as a phase space probe. When in this mode the bunch behaves similar to a macroparticle and oscillates coherently. It is possible to control the growth/damping rate of this oscillation by adjusting the accelerator parameters. Another new tool proposed is the analysis of phase space trajectories in the time-frequency domain. This technique makes it possible to conduct nonlinear dynamics experiments such as observation of high order resonances in the frequency map and single-kick measurement of the tune dependence on the amplitude of oscillations.
A Mega-project on Space Weather Monitoring Gets the Green Light
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
@@ A 200-million-yuan ($25 million) mega-project of science research on space weather monitoring, namely the Meridian Space Weather Moni toting Project (Meridian Project for short), proposed by several research institutes and universities in China has been approved recently by the Chinese government.
The ALTCRISS project on board the International Space Station
Casolino, M; Minori, M; Picozza, P; Fuglesang, C; Galper, A; Popov, A; Benghin, V; Petrov, V M; Nagamatsu, A; Berger, T; Reitz, G; Durante, M; Pugliese, M; Roca, V; Cucinotta, L Sihver F; Semones, E; Shavers, M; Guarnieri, V; Lobascio, C; Castagnolo, D; Fortezza, R
2007-01-01
The Altcriss project aims to perform a long term survey of the radiation environment on board the International Space Station. Measurements are being performed with active and passive devices in different locations and orientations of the Russian segment of the station. The goal is to perform a detailed evaluation of the differences in particle fluence and nuclear composition due to different shielding material and attitude of the station. The Sileye-3/Alteino detector is used to identify nuclei up to Iron in the energy range above 60 MeV/n. Several passive dosimeters (TLDs, CR39) are also placed in the same location of Sileye-3 detector. Polyethylene shielding is periodically interposed in front of the detectors to evaluate the effectiveness of shielding on the nuclear component of the cosmic radiation. The project was submitted to ESA in reply to the AO in the Life and Physical Science of 2004 and data taking began in December 2005. Dosimeters and data cards are rotated every six months: up to now three lau...
Non-linear supersymmetric {sigma}-models and their gauging in the Atiyah-Ward space-time
Energy Technology Data Exchange (ETDEWEB)
Carvalho, M.; Vilar, L.C.Q.; Helayel-Neto, J.A.
1995-10-01
We present a supersymmetric non-linear {sigma}-model built up in the N 1 superspace of Atiyah-ward space-time. A manifold of the Kaehler type comes out that is restricted by a a particular decomposition of the Kaehler potential. The gauging of the {sigma}-model isometries is also accomplished in superspace. (author). 20 refs.
Institute of Scientific and Technical Information of China (English)
WU YUE-XIANG; HUO YAN-MEI; WU YA-KUN
2012-01-01
The main purpose of this paper is to examine the existence of coupled solutions and coupled minimal-maximal solutions for a kind of nonlinear operator equations in partial ordered linear topology spaces by employing the semi-order method.Some new existence results are obtained.
Energy Technology Data Exchange (ETDEWEB)
Chekhov, L.O.
1985-06-01
Matrix nonlinear sigma-model is considered in the case of rectangular matrices of the dimension Nx..alpha..N. Renormalizability of the model with respect to ..alpha.. and 1/N is demonstrated for the case of two-dimensional Euclidean space. Validity of the chiral identity is proved in the operator expansion for the renormalized theory.
Derivation of second-order nonlinear optical conductivity by the projection-diagram method
Directory of Open Access Journals (Sweden)
Nam Lyong Kang
2012-03-01
Full Text Available A projection-diagram method is introduced for optical conductivity with lineshape functions, which takes into account the population criterion that the electron and phonon distribution functions are multiplicatively combined along with the energy conservation factors for proper interpretation of emission and absorption of phonons and photons in all the processes of electron transitions. It is further shown that the second order nonlinear optical conductivity of the system of electrons interacting with phonons, obtained using this method, is identical with that derived by using the state dependent projectors and the KC reduction identities [J. Phys. A: Math. Theor. 43, 165203 (2010]. We expect that this method can reduce the amount of many-body calculation and can be of help in providing physical intuition into solid state quantum dynamics and representing perturbation expressions for such systems.
Chew, Huck Beng
2013-01-01
Determining the tractions along a surface or interface from measurement data in the far-fields of nonlinear materials is a challenging inverse problem which has significant engineering and nanoscience applications. Previously, a field projection method was established to identify the crack-tip cohesive zone constitutive relations in an isotropic elastic solid (Hong and Kim, 2003. J. Mech. Phys. Solids 51, 1267). In this paper, the field projection method is further generalized to extracting the tractions along interfaces bounded by nonlinear materials, both with and without pre-existing cracks. The new formulation is based on Maxwell-Betti's reciprocal theorem with a reciprocity gap associated with nonlinear materials. We express the unknown normal and shear tractions along the interface in terms of the Fourier series, and use specially constructed analytical auxiliary fields in the reciprocal theorem to extract the unknown Fourier coefficients from far-field data; the reciprocity gap in the formulation is iteratively determined with a set of numerical algorithms. Our detailed numerical experiments demonstrate that this nonlinear field projection method (NFPM) is well-suited for extracting the interfacial tractions from the far-field data of any nonlinear elastic or elasto-plastic material with known constitutive laws. Applications of the NFPM to experiments and atomistic simulations are discussed.
A Comprehensive CFD Tool for Aerothermal Environment Around Space Vehicles Project
National Aeronautics and Space Administration — The goal of this SBIR project is to develop an innovative, high fidelity computational tool for accurate prediction of aerothermal environment around space vehicles....
A Comprehensive CFD Tool for Aerothermal Environment Around Space Vehicles Project
National Aeronautics and Space Administration — The goal of this SBIR project is to develop an innovative, high fidelity computational tool for accurate prediction of aerothermal environment around space...
Onboard Space Autonomy Through Integration of Health Management and Control Reconfiguration Project
National Aeronautics and Space Administration — In this SBIR project we propose to integrate spacecraft control and vehicle health functions to improve the robustness and productivity of space operations. The main...
Silicon Carbide Based Power Mangement and Distribution for Space Nuclear Power Systems Project
National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard, 100's kWe power management and distribution (PMAD) system for space nuclear...
National Aeronautics and Space Administration — The Phase I project successfully demonstrated that the advanced non-contacting stress measurement system (NSMS) was able to address closely spaced modes and...
Intelligent, Reusable Software for Plug and Play Space Avionics Project
National Aeronautics and Space Administration — Space Micro proposes to build upon our existing space processing and hardening technologies and products e.g (Proton 200K), to research and develop reusable software...
Coupled Human-Space Suit Mobility Studies Project
National Aeronautics and Space Administration — The space suit is arguably the most intimate piece of space flight hardware yet we know surprisingly little about the interactions between the astronaut and this...
CubeSat Capabilities for Space Science Missions Project
National Aeronautics and Space Administration — The CubeSat Capabilities for Space Science Missions combines science and engineering talent at Goddard Space Flight Center and the Wallops Flight Facility to...
Downlink Fiber Laser Transmitter for Deep Space Communication Project
National Aeronautics and Space Administration — NASA's Space Communications and Navigation (SCaN) roadmap, calls for an integrated network approach to communication and navigation needs for robotic and human space...
In-Space Manufacturing Development and Demonstration Project
National Aeronautics and Space Administration — In-space manufacturing provides the opportunity to build replacement parts on-demand and repair structure to change the paradigm for space exploration mission...
CNT Applique for SHM of Space Structures Project
National Aeronautics and Space Administration — Space structures are unique in that once they are deployed, there is little to no opportunity for manual inspection to assess their integrity. Even on the space...
Downlink Fiber Laser Transmitter for Deep Space Communication Project
National Aeronautics and Space Administration — NASA's Space Communications and Navigation (SCaN) roadmap, calls for an integrated network approach to communication and navigation needs for robotic and human space...
Ultra-Light ?Photonic Muscle? Space Structures Project
National Aeronautics and Space Administration — Fabrication of large space optics that are accurately shaped to better than a 1,000th of the width of a human hair is an enormous challenge. Traditional space...
Fast Neutron Dosimeter for the Space Environment Project
National Aeronautics and Space Administration — Secondary neutrons make a significant contribution to the total absorbed dose received by space crews during long duration space missions However, only a limited...
Multipurpose Cooling Garment for Improved Space Suit Environmental Control Project
National Aeronautics and Space Administration — Future manned space exploration missions will require space suits with capabilities beyond the current state of the art. Portable Life Support Systems for these...
Highly Sensitive Photon Counting Detectors for Deep Space Optical Communications Project
National Aeronautics and Space Administration — This project will focus on fabricating and optimizing a photodetector that utilizes the emerging technology of internal discrete amplification to create...
National Aeronautics and Space Administration — For this project, several different augmentation techniques for locating ground articles from distance through an augmented live view were investigated....
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”.
Hendi, S H; Panah, B Eslam
2016-01-01
In this paper, we take into account the black hole solutions of Einstein gravity in the presence of logarithmic and exponential forms of nonlinear electrodynamics. At first, we consider the cosmological constant as a dynamic pressure to study the analogy of the black hole solutions with the Van der Waals liquid--gas system in the extended phase space. We plot $P-V$, $T-V$ and $G-T$ diagrams and investigate the phase transition of adS black holes in the canonical ensemble. Moreover, we discuss about the effect of nonlinear electrodynamics on the the critical values and the universal ratio $P_{c}v_{c}/T_{c}$.
Ultralightweight PV Array Materials for Deep Space Mission Environments Project
National Aeronautics and Space Administration — Photovoltaic arrays for future deep space NASA missions demand multiple functionalities. They must efficiently generate electrical power, have very large areas and...
An Ultra Low Power Cryo-Refrigerator for Space Project
National Aeronautics and Space Administration — Future NASA Space Science Missions will incorporate detectors, sensors, shields, and telescopes that must be cooled to cryogenic temperatures. An enabling technology...
Recovery of In-Space Cubesat Experiments (RICE) Project
National Aeronautics and Space Administration — ELORET Corporation, in collaboration with the Space Systems Design Laboratory of Georgia Institute of Technology, proposes developing and demonstrating a...
An Ultra Low Power Cryo-Refrigerator for Space Project
National Aeronautics and Space Administration — Future NASA Space Science Missions will incorporate detectors, sensors, shields, and telescopes that must be cooled to cryogenic temperatures. An enabling...
The Conductive Thermal Control Material Systems for Space Applications Project
National Aeronautics and Space Administration — This proposal is submitted to develop and demonstrate the feasibility of processing the space environment stable, multifunctional thermal control material system...
Miniature Flexible Humidity Sensitive Patches for Space Suits Project
National Aeronautics and Space Administration — Advanced space suit technologies demand improved, simplified, long-life regenerative sensing technologies, including humidity sensors, that exceed the performance of...
Security-Enhanced Autonomous Network Management for Space Networking Project
National Aeronautics and Space Administration — Intelligent Automation Inc. (IAI) proposes an innovative Security-Enhanced Autonomous Network Management (SEANM) scheme for reliable communication in space...
The Conductive Thermal Control Material Systems for Space Applications Project
National Aeronautics and Space Administration — This Phase II proposal is submitted to further develop and Validate materials and process engineering of the space environment stable, multifunctional conductive...
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.
Post Process Characterization of Friction Stir Welded Components Project
National Aeronautics and Space Administration — Luna Innovations Incorporated proposes in this STTR Phase II project to continue development and validation of Luna's amplitude-dependent, nonlinear ultrasonic...
Cosmic flows and the expansion of the Local Universe from nonlinear phase-space reconstructions
Hess, Steffen
2014-01-01
We investigate the impact of cosmic flows and density perturbations on Hubble constant $H_0$ measurements using nonlinear phase-space reconstructions of the Local Universe (LU). We rely on a set of 25 N-body simulations which are constrained to resemble the LU within distances of about 90 Mpc/h. These have been randomly extended up to volumes enclosing distances of 360 Mpc/h with augmented Lagrangian perturbation theory (=750 simulations), accounting in this way for effects from from larger scales ($\\sigma_{\\rm large}=134$ km/s). We report on Local Group (LG) speed reconstructions, which are compatible with those derived from the CMB-dipole: $|v_{\\rm LG}|=685\\pm137$ km/s. The direction $(l,b)=(260.5\\pm 13.3,39.1\\pm 10.4)^\\circ$ is found to be compatible with observations. We use the CMB-dipole information to estimate the missing large scale bulk flow component, indicating that we miss a closely perpendicular flow with a magnitude corresponding to $1.4 \\sigma_{\\rm large}$. Considering this, our bulk flow estim...
On Invariant Notions of Segre Varieties in Binary Projective Spaces
Havlicek, Hans; Saniga, Metod
2010-01-01
Invariant notions of a class of Segre varieties $\\Segrem(2)$ of PG(2^m - 1, 2) that are direct products of $m$ copies of PG(1, 2), $m$ being any positive integer, are established and studied. We first demonstrate that there exists a hyperbolic quadric that contains $\\Segrem(2)$ and is invariant under its projective stabiliser group $\\Stab{m}{2}$. By embedding PG(2^m - 1, 2) into \\PG(2^m - 1, 4), a basis of the latter space is constructed that is invariant under $\\Stab{m}{2}$ as well. Such a basis can be split into two subsets of an odd and even parity whose spans are either real or complex-conjugate subspaces according as $m$ is even or odd. In the latter case, these spans can, in addition, be viewed as indicator sets of a $\\Stab{m}{2}$-invariant geometric spread of lines of PG(2^m - 1, 2). This spread is also related with a $\\Stab{m}{2}$-invariant non-singular Hermitian variety. The case $m=3$ is examined in detail to illustrate the theory. Here, the lines of the invariant spread are found to fall into four ...
Vectors, Cyclic Submodules and Projective Spaces Linked with Ternions
Havlicek, Hans
2008-01-01
Given a ring of ternions $R$, i. e., a ring isomorphic to that of upper triangular $2\\times 2$ matrices with entries from an arbitrary commutative field $F$, a complete classification is performed of the vectors from the free left $R$-module $R^{n+1}$, $n \\geq 1$, and of the cyclic submodules generated by these vectors. The vectors fall into $5 + |F|$ and the submodules into 6 distinct orbits under the action of the general linear group $\\GL_{n+1}(R)$. Particular attention is paid to {\\it free} cyclic submodules generated by \\emph{non}-unimodular vectors, as these are linked with the lines of $\\PG(n,F)$, the $n$-dimensional projective space over $F$. In the finite case, $F$ = $\\GF(q)$, explicit formulas are derived for both the total number of non-unimodular free cyclic submodules and the number of such submodules passing through a given vector. These formulas yield a combinatorial approach to the lines and points of $\\PG(n,q)$, $n\\geq 2$, in terms of vectors and non-unimodular free cyclic submodules of $R^{n...
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.
Space Research Institute (IKI) Exhibition as an Educational Project
Sadovski, Andrei; Antonenko, Elena
2016-07-01
The Exhibition "Space Science: Part and Future" in Space Research Institute (IKI) was opened in 2007 in commemoration of the 50th anniversary of the first man-made satellite launch. It covers the latest and the most important findings in space research, shows instruments which are used in space exploration, and presents past, current, and future Russian science missions. Prototypes of space instruments developed by Russian specialists and mockups of spacecraft and spaceships flown to space are displayed, together with information posters, describing space missions, their purposes and results. The Exhibition takes a great part in school space education. Its stuff actively works with schoolchildren, undergraduate students and also makes a great contribution in popularization of space researches. Moreover the possibility to learn about scientific space researches first-hand is priceless. We describe the main parts of the Exhibition and forms of it work and also describe the collaboration with other museums and educational organizations.
Cheng, Kung-Shan; Yuan, Yu; Li, Zhen; Stauffer, Paul R.; Joines, William T.; Dewhirst, Mark W.; Das, Shiva K.
2009-02-01
Purpose: Blood perfusion is a well-known factor that complicates accurate control of heating during hyperthermia treatments of cancer. Since blood perfusion varies as a function of time, temperature and location, determination of appropriate power deposition pattern from multiple antenna array Hyperthermia systems and heterogeneous tissues is a difficult control problem. Therefore, we investigate the applicability of a real-time eigenvalue model reduction (virtual source - VS) reduced-order controller for hyperthermic treatments of tissue with nonlinearly varying perfusion. Methods: We impose a piecewise linear approximation to a set of heat pulses, each consisting of a 1-min heat-up, followed by a 2-min cool-down. The controller is designed for feedback from magnetic resonance temperature images (MRTI) obtained after each iteration of heat pulses to adjust the projected optimal setting of antenna phase and magnitude for selective tumor heating. Simulated temperature patterns with additive Gaussian noise with a standard deviation of 1.0°C and zero mean were used as a surrogate for MRTI. Robustness tests were conducted numerically for a patient's right leg placed at the middle of a water bolus surrounded by a 10-antenna applicator driven at 150 MHz. Robustness tests included added discrepancies in perfusion, electrical and thermal properties, and patient model simplifications. Results: The controller improved selective tumor heating after an average of 4-9 iterative adjustments of power and phase, and fulfilled satisfactory therapeutic outcomes with approximately 75% of tumor volumes heated to temperatures >43°C while maintaining about 93% of healthy tissue volume time to only 4 to 9% of the original value. Conclusions: Using a piecewise linear approximation to a set of heat pulses in a VS reduced-order controller, the proposed algorithm greatly improves the efficiency of hyperthermic treatment of leg sarcomas while accommodating practical nonlinear variation of
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.
Um, Myoung-Jin; Kim, Yeonjoo; Markus, Momcilo; Wuebbles, Donald J.
2017-09-01
Climate extremes, such as heavy precipitation events, have become more common in recent decades, and nonstationarity concepts have increasingly been adopted to model hydrologic extremes. Various issues are associated with applying nonstationary modeling to extremes, and in this study, we focus on assessing the need for different forms of nonlinear functions in a nonstationary generalized extreme value (GEV) model of different annual maximum precipitation (AMP) time series. Moreover, we suggest an efficient approach for selecting the nonlinear functions of a nonstationary GEV model. Based on observed and multiple projected AMP data for eight cities across the U.S., three separate tasks are proposed. First, we conduct trend and stationarity tests for the observed and projected data. Second, AMP series are fit with thirty different nonlinear functions, and the best functions among these are selected. Finally, the selected nonlinear functions are used to model the location parameter of a nonstationary GEV model and stationary and nonstationary GEV models with a linear function. Our results suggest that the simple use of nonlinear functions might prove useful with nonstationary GEV models of AMP for different locations with different types of model results.
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
Theesar, S Jeeva Sathya; Balasubramaniam, P; Banerjee, Santo
2012-09-01
In Chaos 19, 013102 (2009), the author proposed generalized projective synchronization for time delay systems using nonlinear observer and obtained sufficient condition to ensure projective synchronization for modulated time varying delay. There are concerns with the obtained conditions as the result was applicable only to trivial case of time varying delay τ[over dot](1)(t)=dτ(1)(t)/dt<1. In this paper, we note the drawbacks of the proposed sufficient condition. The new improved sufficient condition for ensuring the projective synchronization of time varying delayed systems is presented. The proposed new criteria have been verified by adopting the Ikeda system.
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.
Directory of Open Access Journals (Sweden)
Chen Xiong
2016-01-01
Full Text Available Although the structured light system that uses digital fringe projection has been widely implemented in three-dimensional surface profile measurement, the measurement system is susceptible to non-linear error. In this work, we propose a convenient look-up-table-based (LUT-based method to compensate for the non-linear error in captured fringe patterns. Without extra calibration, this LUT-based method completely utilizes the captured fringe pattern by recording the full-field differences. Then, a phase compensation map is established to revise the measured phase. Experimental results demonstrate that this method works effectively.
Nonlinear ion-acoustic solitary waves with warm ions and non-Maxwellian electrons in space plasmas
Hussain Shah, Khalid; Qureshi, Nouman
2017-04-01
Electrons velocity distributions are often observed with non-Maxwellian features such flat tops at low energies and/or superthermal tails at high energies from different regions of near Earth plasmas such as Earth's bow shock, auroral zone and magnetosphere by numerous satellites. Such non-Maxwellian distributions are well modelled by generalized (r,q) distribution or Cairns distribution. Solitons are nonlinear solitary structures and are integral part of space plasmas. In this paper, we present a fluid model containing Cairns (r,q) distributed non-Maxwellian electrons and derive the Sagdeev potential for fully nonlinear fluid equations. We found that compressive solitons can be developed in such a plasma. The results from our model can be used to interpret solitary structures in space plasmas when electrons are obeying the non-Maxwellian flat tops along with the high energy tails.
Design of nonlinear discrete-time controllers using a parameter space sampling procedure
Young, G. E.; Auslander, D. M.
1983-01-01
The design of nonlinear discrete-time controllers is investigated where the control algorithm assumes a special form. State-dependent control actions are obtained from tables whose values are the design parameters. A new design methodology capable of dealing with nonlinear systems containing parameter uncertainty is used to obtain the controller design. Various controller strategies are presented and illustrated through an example.
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.
Multifunctional Metal-Polymer Nanocomposites for Space Applications Project
National Aeronautics and Space Administration — NASA has identified a need for new high performance-to-weight materials capable of protecting critical components from the space environment, mitigating threat of...
An Advanced Light Weight Recuperator for Space Power Systems Project
National Aeronautics and Space Administration — Nuclear Electric Propulsion (NEP) technology holds great promise for power and propulsion demands of NASA current and future deep space explorations. Closed Brayton...
Simulating Emerging Space Industries with Agent-Based Modeling Project
National Aeronautics and Space Administration — The Vision for Space Exploration (VSE) calls for encouraging commercial participation as a top-level objective. Given current and future commercial activities, how...
Space Qualified, Radiation Hardened, Dense Monolithic Flash Memory Project
National Aeronautics and Space Administration — Space Micro proposes to build a radiation hardened by design (RHBD) flash memory, using a modified version of our RH-eDRAM Memory Controller to solve all the single...
Temperature Sensing Solution for Cryogenic Space Engines Project
National Aeronautics and Space Administration — Cryogenic systems, heavily used in rocket ground testing, space station operations, shuttle launch systems, etc, require a large number of temperature sensors for...
Agile cognitive space radio demo on ISS Project
National Aeronautics and Space Administration — Space Micro's technology features the use of a FPMA or field programmabe microwave array that is Multi-band and multi-waveform capable. The FPMA can be integrated...
Radiation Hard Space Wire Gigabit Ethernet Compatible Transponder Project
National Aeronautics and Space Administration — Current and future programs of near-Earth and deep space exploration performed by NASA and Department of Defense require the development of reconfigurable,...
An Advanced Light Weight Recuperator for Space Power Systems Project
National Aeronautics and Space Administration — Closed Brayton Cycle (CBC) space power system is one of the most efficient energy conversion technologies for nuclear and solar electric propulsion. The recuperator...
Deep Space Navigation and Timing Architecture and Simulation Project
National Aeronautics and Space Administration — Microcosm will develop a deep space navigation and timing architecture and associated simulation, incorporating state-of-the art radiometric, x-ray pulsar, and laser...
Polymer Flip Chips with Extreme Temperature Stability in Space Project
National Aeronautics and Space Administration — The objective of the proposed SBIR Phase I program is to develop highly thermally and electrically conductive nanocomposites for space-based flip chips for...
Low-power formaldehyde detector for space applications Project
National Aeronautics and Space Administration — Trace contamination of the International Space Station (ISS) by formaldehyde?a known carcinogen? is a significant potential threat to crew health. The spacecraft...
Low-Power Formaldehyde Detector for Space Applications Project
National Aeronautics and Space Administration — Trace contamination of the International Space Station (ISS) by formaldehyde -- a known carcinogen -- is a significant threat to crew health. The spacecraft maximum...
High Power Uplink Amplifier for Deep Space Communications Project
National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...
Space-Qualified 1064 nm Seed and Metrology Laser Project
National Aeronautics and Space Administration — Several instruments that are potential candidates for future space-based NASA missions require a highly stable, single frequency laser oscillator that is wavelength...
In-Space Friction Stir Welding Machine Project
National Aeronautics and Space Administration — Longhurst Engineering, PLC, and Vanderbilt University propose an in-space friction stir welding (FSW) machine for joining complex structural aluminum components. The...
Green Liquid Monopropellant Thruster for In-space Propulsion Project
National Aeronautics and Space Administration — Physical Sciences Inc. and AMPAC In-space Propulsion propose to develop a unique chemical propulsion system for the next generation NASA science spacecraft and...
Affordable Access to Space (AAS): Affordable Vehicle Avionics Project
National Aeronautics and Space Administration — Affordable Vehicle Avionics (AVA) is being developed at NASA Ames Research Center and is sponsored by Space Technology Mission Directorate (STMD) Game Changing...
In-Space Distributed Fiber Optic Hydrogen Leak Sensor Project
National Aeronautics and Space Administration — Broadband Photonics Inc. proposes development of a patent-pending distributed fiber optic sensor for in-space hydrogen leak detection. Reliable and fast detection of...
In-Space Cryogenic VOST Connect/Disconnect Project
National Aeronautics and Space Administration — Two novel cryogenic couplings will be designed, fabricated and tested. Intended for in-space use at cryogenic propellant depots, the couplings are based on patented...
In-Space Cryogenic VOST Connect/Disconnect Project
National Aeronautics and Space Administration — A novel cryogenic coupling will be designed and modeled. Intended for in-space use at cryogenic propellant depots, the coupling is based on patented Venturi-Offset...
Graphene Nanocomposite Cathode for Advanced Space Battery Project
National Aeronautics and Space Administration — High efficiency power systems are needed for NASA's future human exploration of space and such power systems must have advanced safety feature and provide high...
Advanced Thermal Interface Material Systems for Space Applications Project
National Aeronautics and Space Administration — The ultimate aim of proposed efforts are to develop innovative material and process (M&P) engineering technology to reduce thermal resistance between space power...
Iodine Stabilized Seed Laser for Space Applications Project
National Aeronautics and Space Administration — The overall goal of this SBIR effort is development of a space qualifiable, compact, frequency stabilized seed laser with low SWaP for routine use in NASA LaRC's...
Deployable solar energy generators for deep space cubesats Project
National Aeronautics and Space Administration — Cubesats require highly compact technologies to maximize their effectiveness. As cubesats are expected to be low-cost and, relative to the space industry, mass...
Novel Composite Membrane for Space Life Supporting System Project
National Aeronautics and Space Administration — Space life-supporting systems require effective removal of metabolic CO2 from the cabin atmosphere with minimal loss of O2. Conventional techniques, using either...
Space Qualified, Radiation Hardened, Dense Monolithic Flash Memory Project
National Aeronautics and Space Administration — Radiation hardened nonvolatile memories for space is still primarily confined to EEPROM. There is high density effective or cost effective NVM solution available to...
Space-Qualified 1064 nm Seed and Metrology Laser Project
National Aeronautics and Space Administration — A space-qualified, single-frequency oscillator operating at 1064 nm is a critical component for a number of active optical measurement systems that have been...
Iodine Stabilized Seed Laser for Space Applications Project
National Aeronautics and Space Administration — This SBIR Phase I effort proposes to establish the feasibility of leveraging advances in compact laser technology with integration of space qualified techniques into...
Multifunctional, Nanostructured Metal Rubber Protective Films for Space Exploration Project
National Aeronautics and Space Administration — NanoSonic has developed revolutionary nanostructured, yet macroscale, multifunctional Metal RubberTM films. In support of NASA's Vision for Space Exploration, low...
High Temperature Electrical Insulation Materials for Space Applications Project
National Aeronautics and Space Administration — NASA's future space science missions cannot be realized without the state of the art high temperature insulation materials of which higher working temperature, high...
High Power Uplink Amplifier for Deep Space Communications Project
National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...
Radiation-Tolerant, Space Wire-Compatible Switching Fabric Project
National Aeronautics and Space Administration — Current and future programs of near-Earth and deep space exploration require the development of faster and more reliable electronics with open system architectures...
Radiation-Tolerant, Space Wire-Compatible Switching Fabric Project
National Aeronautics and Space Administration — Current and future programs of near-Earth and deep space exploration require the development of robust serial data transfer electronics within the spacecraft's...
Small Space Platform Enhanced Internet Protocol Stack Device Project
National Aeronautics and Space Administration — To address the NASA/ARC need for wireless networking technologies for small launch vehicles, Broadata Communications, Inc. proposes to develop a new Small Space...
In-Space Distributed Fiber Optic Hydrogen Leak Sensor Project
National Aeronautics and Space Administration — Broadband Photonics Inc. proposes development of a patent-pending distributed fiber optic sensor for in-space hydrogen leak detection. Reliable and fast detection of...
Hendi, S H; Momennia, M
2015-01-01
In this paper, we consider quadratic Maxwell invariant as a correction to the Maxwell theory and study thermodynamic behavior of the black holes in Einstein (EN) and Gauss-Bonnet (GB) gravities. We consider cosmological constant as a thermodynamic pressure to extend phase space. Next, we obtain critical values in case of variation of nonlinearity and GB parameters. We generalized the study by considering the effects of dimensionality on critical values and make comparisons between our models with their special sub classes.
Symplectic geometry of the moduli space of projective structures in homological coordinates
Bertola, Marco; Norton, Chaya
2015-01-01
We introduce a natural symplectic structure on the moduli space of quadratic differentials with simple zeros and describe its Darboux coordinate systems in terms of so-called homological coordinates. We then show that this structure coincides with the canonical Poisson structure on the cotangent bundle of the moduli space of Riemann surfaces, and therefore the homological coordinates provide a new system of Darboux coordinates. We define a natural family of commuting "homological flows" on the moduli space of quadratic differentials and find the corresponding action-angle variables. The space of projective structures over the moduli space can be identified with the cotangent bundle upon selection of a reference projective connection that varies holomorphically and thus can be naturally endowed with a symplectic structure. Different choices of projective connections of this kind (Bergman, Schottky, Wirtinger) give rise to equivalent symplectic structures on the space of projective connections but different sym...
The Connection Between the Metric and Generalized Projection Operators in Banach Spaces
Institute of Scientific and Technical Information of China (English)
Yakov ALBER; Jin Lu LI
2007-01-01
In this paper we study the connection between the metric projection operator PK:B→K,where B is a reflexive Banach space with dual space B* and K is a non-empty closed convex subset of B, and the generalized projection oprators Πk:B→k and πk:B*→k.We also present some results in non-reflexive Banach spaces.
Multifunctional Metal/Polymer Composite Fiber for Space Applications Project
National Aeronautics and Space Administration — In this Small Business Innovation Research Phase II Program, Syscom Technology, Inc. will implement an integrated processing scheme to fabricate a conductive...
Novel High Temperature Magnetic Bearings for Space Vehicle Systems Project
National Aeronautics and Space Administration — Previous high temperature magnetic bearings employed electromagnets only. The work proposed in this SBIR program seeks to utilize High Temperature Permanent Magnets...
Novel High Temperature Magnetic Bearings for Space Vehicle Systems Project
National Aeronautics and Space Administration — Previous high temperature magnetic bearings employed only electromagnets. The work proposed in this SBIR program seeks to utilize High Temperature Permanent Magnets...
Multifunctional Metal/Polymer Composite Fiber for Space Applications Project
National Aeronautics and Space Administration — In this Small Business Innovation Research Phase I Program, Syscom Technology, Inc. (STI) will fabricate a metallized multifunctional composite fiber from a...
Thermo-Acoustic Convertor for Space Power Project
National Aeronautics and Space Administration — Sunpower will introduce thermoacoustic Stirling heat engine (TASHE) technology into its existing Stirling convertor technology to eliminate the moving mechanical...
Silicon Carbide Corrugated Mirrors for Space Telescopes Project
National Aeronautics and Space Administration — Trex Enterprises Corporation (Trex) proposes technology development to manufacture monolithic, lightweight silicon carbide corrugated mirrors (SCCM) suitable for...
Battery Diagnostics and Prognostics for Space Applications Project
National Aeronautics and Space Administration — Global Technology Connection, Inc., in collaboration with Georgia Tech (Center for Fuel Cell and Battery Technologies) and our industrial partner, Eagle Pichers,...
Electrochemical Hydrogen Peroxide Generator for Multiple Applications in Space Project
National Aeronautics and Space Administration — Controlled Ecological Life Support System (CELSS) facilities require the development of reliable systems for the disinfection of microorganisms. There are several...
Low Cost Method of Manufacturing Space Optics Project
National Aeronautics and Space Administration — Proposed is the development of a manufacturing technology that will increase feasible large optics design options and significantly reduce the manufacturing time,...
Modular, Fault-Tolerant Electronics Supporting Space Exploration Project
National Aeronautics and Space Administration — AeroAstro's innovative design approach for implementing reconfigurable electronics frees the spacecraft designer to concentrate on the mission at hand with...
Institute of Scientific and Technical Information of China (English)
陈化; 罗壮初
2002-01-01
In this paper the authors study a class of non-linear singular partial differential equation in complex domain Ct × Cnx. Under certain assumptions, they prove the existence and uniqueness of holomorphic solution near origin of Ct × Cnx.
ITERATIVE SOLUTIONS FOR SYSTEMS OF NONLINEAR OPERATOR EQUATIONS IN BANACH SPACE
Institute of Scientific and Technical Information of China (English)
宋光兴
2003-01-01
By using partial order method, the existence, uniqueness and iterative ap-proximation of solutions for a class of systems of nonlinear operator equations in Banachspace are discussed. The results obtained in this paper extend and improve recent results.
Indian Academy of Sciences (India)
K Balachandran; K Uchiyama
2000-05-01
In this paper we prove the existence of mild and strong solutions of a nonlinear integrodifferential equation of Sobolev type with nonlocal condition. The results are obtained by using semigroup theory and the Schauder fixed point theorem.
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.
Quach, Minh; Brunel, Nicolas; d'Alché-Buc, Florence
2007-12-01
Statistical inference of biological networks such as gene regulatory networks, signaling pathways and metabolic networks can contribute to build a picture of complex interactions that take place in the cell. However, biological systems considered as dynamical, non-linear and generally partially observed processes may be difficult to estimate even if the structure of interactions is given. Using the same approach as Sitz et al. proposed in another context, we derive non-linear state-space models from ODEs describing biological networks. In this framework, we apply Unscented Kalman Filtering (UKF) to the estimation of both parameters and hidden variables of non-linear state-space models. We instantiate the method on a transcriptional regulatory model based on Hill kinetics and a signaling pathway model based on mass action kinetics. We successfully use synthetic data and experimental data to test our approach. This approach covers a large set of biological networks models and gives rise to simple and fast estimation algorithms. Moreover, the Bayesian tool used here directly provides uncertainty estimates on parameters and hidden states. Let us also emphasize that it can be coupled with structure inference methods used in Graphical Probabilistic Models. Matlab code available on demand.
Projective limits of state spaces I. Classical formalism
Lanéry, Suzanne; Thiemann, Thomas
2017-01-01
In this series of papers, we investigate the projective framework initiated by Jerzy Kijowski (1977) and Andrzej Okołów (2009, 2013, 2014), which describes the states of a quantum (field) theory as projective families of density matrices. A short reading guide to the series can be found in [27]. The present first paper aims at clarifying the classical structures that underlies this formalism, namely projective limits of symplectic manifolds [27, subsection 2.1]. In particular, this allows us to discuss accurately the issues hindering an easy implementation of the dynamics in this context, and to formulate a strategy for overcoming them [27, subsection 4.1].
Nanda, Sudarsan
2013-01-01
"Nonlinear analysis" presents recent developments in calculus in Banach space, convex sets, convex functions, best approximation, fixed point theorems, nonlinear operators, variational inequality, complementary problem and semi-inner-product spaces. Nonlinear Analysis has become important and useful in the present days because many real world problems are nonlinear, nonconvex and nonsmooth in nature. Although basic concepts have been presented here but many results presented have not appeared in any book till now. The book could be used as a text for graduate students and also it will be useful for researchers working in this field.
DEFF Research Database (Denmark)
Rahman, Imadur Mohamed; Marchetti, Nicola; Fitzek, Frank;
2005-01-01
In this work, we have analyzed a joint spatial diversity and multiplexing transmission structure for MIMO-OFDM system, where Orthogonal Space-Frequency Block Coding (OSFBC) is used across all spatial multiplexing branches. We have derived a BLAST-like non-linear Successive Interference Cancellation...... in this paper. We have found that a linear two-stage receiver for the proposed system [1] performs very close to the non-linear receiver studied in this work. Finally, we compared the system performance in spatially correlated scenario. It is found that higher amount of spatial correlation at the transmitter...... (SIC) receiver where the detection is done on subcarrier by sub-carrier basis based on both Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) nulling criterion for the system. In terms of Frame Error Rate (FER), MMSE based SIC receiver performs better than all other receivers compared...
High Performance Arm for an Exploration Space Suit Project
National Aeronautics and Space Administration — Final Frontier Design (FFD) proposes to develop and deliver an advanced pressure garment arm with low torque and high Range of Motion (ROM), and increased...
Advanced Space Power Systems (ASPS): Advanced Energy Storage Systems Project
National Aeronautics and Space Administration — The development of high specific energy devices will enable NASA’s future robotic and human-exploration missions. The need for advances in energy storage...
NIST in Space: Better Remote Sensors for Better Science Project
National Aeronautics and Space Administration — This NASA Innovative Research Grant activity conducts engineering analysis to demonstrate the feasibility and advantages of applyi?ng a breakthrough remote sensor...
Prevention of Renal Stone Complications in Space Exploration Project
National Aeronautics and Space Administration — AIM 1. Refine ultrasound probes to detect, reposition, and fragment kidney stones. Task 1.1. Select imaging probe for stone repositioning. Clinical trials are...
Thermo-Acoustic Convertor for Space Power Project
National Aeronautics and Space Administration — In Phase Sunpower looked at Thermoacoustic Stirling Heat Engines (TASHEs). These ranged from a TASHE which was sized for the heat from a single General Purpose Heat...
Novel Materials for Mirror Substrate in Space Telescopes Project
National Aeronautics and Space Administration — Advanced Materials Technology, Inc (AMTI) responds to the NASA solicitation S2 "Advanced Telescope Systems" under subtopic S2.05, "Optics Manufacturing and Metrology...
Modular, Fault-Tolerant Electronics Supporting Space Exploration Project
National Aeronautics and Space Administration — Modern electronic systems tolerate only as many point failures as there are redundant system copies, using mere macro-scale redundancy. Fault Tolerant Electronics...
Deep Space Navigation and Timing Architecture and Simulation Project
National Aeronautics and Space Administration — The Microcosm team will complete the simulation tool architecture early in Phase II, and in parallel begin to develop the simulation. The tool is architected for...
Universal Brushless-DC Motor Controller for Space Applications Project
National Aeronautics and Space Administration — The goal of this SBIR is to adapt an initial prototype ultra-miniature high-performance brushless-DC-motor controller, code named 'Puck', for use by NASA across a...
Cryogenic Vibration Damping Mechanisms for Space Telescopes and Interferometers Project
National Aeronautics and Space Administration — In its mission to understand how galaxies, stars, and planetary systems form, NASA's Origins Technology Program calls for advances in "enabling component and...
Radiation Hard Space Wire Gigabit Ethernet Compatible Transponder Project
National Aeronautics and Space Administration — High-bandwidth, Radiation Hardening, low-power, low-EMI, easily reconfigurable and upgradeable transponder-based interconnects between processor nodes, subsystems,...
Efficient Space Hardy Thermoelectric Materials with Broad Temperature Range Project
National Aeronautics and Space Administration — The goal of this work is to develop new thermoelectric materials for use in fabricating solid state cooling devices and electrical power generators, which are 200 to...
A Reliable Electronic Package for Space Exploration Project
National Aeronautics and Space Administration — The proposed program will develop an hermetic, CTE matched, thermal shock resistant ceramic packaging technology that will facilitate the operation of Si and SiGe...
Small Space Platform Enhanced Internet Protocol Stack Device Project
National Aeronautics and Space Administration — Wireless communication of small, nano and micro satellites will play a vital role to NASA mission and marketability of the satellite. The use of an Internet-based...
Space/Flight Operable Miniature Six Axis Transducer Project
National Aeronautics and Space Administration — FUTEK will fully design and manufacture a sensor capable of measuring forces in and about each axis. The unit will measure forces up to 300 Newton's in the principle...
Nano-Particle Scandate Cathode for Space Communications Project
National Aeronautics and Space Administration — We propose an improved cathode based on our novel theory of the role of scandium oxide in enhancing emission in tungsten impregnate cathodes. Recent results have...
Fast GC for Space Applications Based on PIES Technology Project
National Aeronautics and Space Administration — Development of a novel analytical instrument which combines the advantages of fast GC and a detector capable of identifying species is proposed. Experiments in the...
Human Robotic Systems (HRS): Space Robotics Challenge Project
National Aeronautics and Space Administration — During 2013 and 2015, the DARPA Robotics Challenge explored through a competition the tasks and technologies for robots to operate in a natural and man-made...
Advanced In-Space Propulsion (AISP): Iodine Hall Thruster Project
National Aeronautics and Space Administration — Iodine propellant offers many enabling capabilities for both SmallSat application and for high power system level implementation. Some of the highest risk...
Extremely High Suction Performance Inducers for Space Propulsion Project
National Aeronautics and Space Administration — The proposed innovation provides a way to design low flow coefficient inducers that have higher cavitation breakdown margin, larger blade angles, thicker more...
Extremely High Suction Performance Inducers for Space Propulsion Project
National Aeronautics and Space Administration — Advanced pump inducer design technology that uses high inlet diffusion blades, operates at a very low flow coefficient, and employs a cavitation control and...
Brain Machine Interfaces for Robotic Control in Space Applications Project
National Aeronautics and Space Administration — This SBIR will study the application of a brain machine interface (BMI) to enable crew to remotely operate and monitor robots from inside a flight vehicle, habitat...
A Low Input Power Cryocooler for Space Applications Project
National Aeronautics and Space Administration — Future NASA missions will require cryocoolers providing cooling capacities upwards of 0.3W at 35K with heat rejection capability to temperature sinks as low as 150K...
Super Lightweight, Metal Rubber Fabric for Extreme Space Environments Project
National Aeronautics and Space Administration — NanoSonic has fabricated revolutionary nanostructured, yet macroscale, multifunctional Metal RubberTM films via layer-by-layer, molecular self-assembly, which...
Radiation Resistant, Reconfigurable, Shape Memory Metal Rubber Space Arrays Project
National Aeronautics and Space Administration — NanoSonic has demonstrated that Shape Memory Metal RubberTM (SM-MR) adaptive skins exhibit reconfigurable and durable RF properties. It is hypothesized that such...
Safety via Thermal Shutdown for Space Rated Batteries Project
National Aeronautics and Space Administration — Li-ion battery safety has inspired many safety features from CID, to safety valves. However, none of the current features protect a battery from internal...
Improved Rhenium Thrust Chambers for In-Space Propulsion Project
National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems (RCS) for future NASA missions such...
Real Time Space Radiation Effects in Electronic Systems Project
National Aeronautics and Space Administration — The ability to predict the occurrence and magnitude of solar particle events (coronal mass ejections and solar flares) has been elusive so exposure of astronauts and...
Lower Profile, Lighter Weight Space Suit Bearings Project
National Aeronautics and Space Administration — Air-Lock will deliver a final report based on the follwoing: 1. Historical summary of bearing design evolution throughout the life of the EMU Program 2. Material...
Bodies in Space - Online Education for Secondary School Students Project
National Aeronautics and Space Administration — This SBIR application proposes to develop, evaluate, and implement an Internet-based educational outreach site focusing on the varied biological effects of...
Green Liquid Monopropellant Thruster for In-space Propulsion Project
National Aeronautics and Space Administration — Physical Sciences Inc. (PSI) and Orbitec Inc. propose to develop a unique chemical propulsion system for the next generation NASA science spacecraft and missions...
LunarCube for Deep Space Missions Project
National Aeronautics and Space Administration — Busek Co., Inc. and Morehead State University propose to develop a 6U CubeSat capable of reaching a lunar orbit from GEO. The primary objective is to demonstrate...
Lightweight InP Solar Cells for Space Applications Project
National Aeronautics and Space Administration — The innovation in this Phase II SBIR is the development of a technology which will enable the manufacture of a lightweight, low cost, high radiation resistance InP...
Cryocooler With Cold Compressor for Deep Space Applications Project
National Aeronautics and Space Administration — The unique built-in design features of the proposed mini pulse tube cryocooler avoid all thermal expansion issues enabling it to operate within a cold, 150 K...
Striction-based Power Monitoring in Space Environment Project
National Aeronautics and Space Administration — The program will leverage recent advances in striction materials and coupled striction devices as to enable highly isolated (analog) voltage and current flow sensors...
Joining Silicon Carbide Components for Space Propulsion Project
National Aeronautics and Space Administration — This SBIR Phase I program will identify the joining materials and demonstrate the processes that are suited for construction of advanced ceramic matrix composite...
Soldier/Warfighter Operationally Responsive Deployer for Space (SWORDS) Project
National Aeronautics and Space Administration — SWORDS will place nanosatellites into precise low earth orbits to provide capabilities both where and when they are needed. Nanosatellites will no longer have to...
A Cold Cycle Dilution Refrigerator for Space Applications Project
National Aeronautics and Space Administration — The cold cycle dilution refrigerator is a continuous refrigerator capable of cooling to temperatures below 100 mK that makes use of a novel thermal magnetic pump....
Space Electronics Operating at High Temperatures and Radiation Levels Project
National Aeronautics and Space Administration — The objective is to produce high efficiency DC/DC power modules in a small low profile package that can tolerate extreme environment conditions. The primary effort...
Cryocooler With Cold Compressor for Deep Space Applications Project
National Aeronautics and Space Administration — The innovation is a high-frequency single-stage pulse tube cryocooler (PTC) that operates at a heat rejection temperature of 150 K. It employs a flexure-bearing...
Space Electronics Operating at High Temperatures and Radiation Levels Project
National Aeronautics and Space Administration — The proposal represents a radical revolution in Power Management & Distribution (PMAD) that addresses many of the challenges for NASA missions that will operate...
Integrated Health Management for Space Flight Digital Systems Project
National Aeronautics and Space Administration — This proposal addresses the need for a real-time Prognostics and Health Management (PHM) system to identify anomalous states in digital electronic systems used in...
A Medipix-Based Small Personal Space Radiation Dosimeter Project
National Aeronautics and Space Administration — This SBIR effort will take the first step in improving the existing Medipix dosimeter technology in terms of advancing the technique now used to couple the actual...
Striction-based Power Monitoring in Space Environment Project
National Aeronautics and Space Administration — The program delivers a completely new technology solution to isolation and sensing of power flow (current and voltage). Based on striction materials technology,...
Space Applications for Ensemble Detection and Analysis Project
National Aeronautics and Space Administration — Ensemble Detection is both a measurement technique and analysis tool. Like a prism that separates light into spectral bands, an ensemble detector mixes a signal with...
Fast Neutron Dosimeter for the Space Environment Project
National Aeronautics and Space Administration — Model calculations and risk assessment estimates indicate that secondary neutrons, with energies ranging between 0.5 to >150 MeV, make a significant contribution...
Optical Real-Time Space Radiation Monitor Project
National Aeronautics and Space Administration — Real-time dosimetry is needed to provide immediate feedback, so astronauts can minimize their exposure to ionizing radiation during periods of high solar activity....
SCONES: Secure Content-Oriented Networking for Exploring Space Project
National Aeronautics and Space Administration — We envision a secure content-oriented internetwork as a natural generalization of the cache-and-forward architecture inherent in delay-tolerant networks. Using our...
Universal Sample Preparation Module for Molecular Analysis in Space Project
National Aeronautics and Space Administration — Lynntech proposes to develop and demonstrate the ability of a compact, light-weight, and automated universal sample preparation module (USPM) to process samples from...