Quantum superpositions of crystalline structures
Baltrusch, Jens D.; Morigi, Giovanna; Cormick, Cecilia; De Chiara, Gabriele; Calarco, Tommaso
2011-12-15
A procedure is discussed for creating coherent superpositions of motional states of ion strings. The motional states are across the structural transition linear-zigzag, and their coherent superposition is achieved by means of spin-dependent forces, such that a coherent superposition of the electronic states of one ion evolves into an entangled state between the chain's internal and external degrees of freedom. It is shown that the creation of such an entangled state can be revealed by performing Ramsey interferometry with one ion of the chain.
Luy, B; Glaser, S J
2001-01-01
The superposition of scalar and residual dipolar couplings gives rise to so-called cylindrical mixing Hamiltonians in dipolar coupling spectroscopy. General analytical polarization and coherence transfer functions are presented for three cylindrically coupled spins 12 under energy-matched conditions. In addition, the transfer efficiency is analyzed as a function of the relative coupling constants for characteristic special cases.
Using least median of squares for structural superposition of flexible proteins
Liu, Yu-Shen; Fang, Yi; Ramani, Karthik
2009-01-01
Background The conventional superposition methods use an ordinary least squares (LS) fit for structural comparison of two different conformations of the same protein. The main problem of the LS fit that it is sensitive to outliers, i.e. large displacements of the original structures superimposed. Results To overcome this problem, we present a new algorithm to overlap two protein conformations by their atomic coordinates using a robust statistics technique: least median of squares (LMS). In order to effectively approximate the LMS optimization, the forward search technique is utilized. Our algorithm can automatically detect and superimpose the rigid core regions of two conformations with small or large displacements. In contrast, most existing superposition techniques strongly depend on the initial LS estimating for the entire atom sets of proteins. They may fail on structural superposition of two conformations with large displacements. The presented LMS fit can be considered as an alternative and complementary tool for structural superposition. Conclusion The proposed algorithm is robust and does not require any prior knowledge of the flexible regions. Furthermore, we show that the LMS fit can be extended to multiple level superposition between two conformations with several rigid domains. Our fit tool has produced successful superpositions when applied to proteins for which two conformations are known. The binary executable program for Windows platform, tested examples, and database are available from . PMID:19159484
Wu, Vincent W.C.; Tse, Teddy K.H.; Ho, Cola L.M.; Yeung, Eric C.Y.
2013-07-01
Monte Carlo (MC) simulation is currently the most accurate dose calculation algorithm in radiotherapy planning but requires relatively long processing time. Faster model-based algorithms such as the anisotropic analytical algorithm (AAA) by the Eclipse treatment planning system and multigrid superposition (MGS) by the XiO treatment planning system are 2 commonly used algorithms. This study compared AAA and MGS against MC, as the gold standard, on brain, nasopharynx, lung, and prostate cancer patients. Computed tomography of 6 patients of each cancer type was used. The same hypothetical treatment plan using the same machine and treatment prescription was computed for each case by each planning system using their respective dose calculation algorithm. The doses at reference points including (1) soft tissues only, (2) bones only, (3) air cavities only, (4) soft tissue-bone boundary (Soft/Bone), (5) soft tissue-air boundary (Soft/Air), and (6) bone-air boundary (Bone/Air), were measured and compared using the mean absolute percentage error (MAPE), which was a function of the percentage dose deviations from MC. Besides, the computation time of each treatment plan was recorded and compared. The MAPEs of MGS were significantly lower than AAA in all types of cancers (p<0.001). With regards to body density combinations, the MAPE of AAA ranged from 1.8% (soft tissue) to 4.9% (Bone/Air), whereas that of MGS from 1.6% (air cavities) to 2.9% (Soft/Bone). The MAPEs of MGS (2.6%±2.1) were significantly lower than that of AAA (3.7%±2.5) in all tissue density combinations (p<0.001). The mean computation time of AAA for all treatment plans was significantly lower than that of the MGS (p<0.001). Both AAA and MGS algorithms demonstrated dose deviations of less than 4.0% in most clinical cases and their performance was better in homogeneous tissues than at tissue boundaries. In general, MGS demonstrated relatively smaller dose deviations than AAA but required longer computation time.
Shah, Shweta B; Sahinidis, Nikolaos V
2012-01-01
Protein structure alignment is the problem of determining an assignment between the amino-acid residues of two given proteins in a way that maximizes a measure of similarity between the two superimposed protein structures. By identifying geometric similarities, structure alignment algorithms provide critical insights into protein functional similarities. Existing structure alignment tools adopt a two-stage approach to structure alignment by decoupling and iterating between the assignment evaluation and structure superposition problems. We introduce a novel approach, SAS-Pro, which addresses the assignment evaluation and structure superposition simultaneously by formulating the alignment problem as a single bilevel optimization problem. The new formulation does not require the sequentiality constraints, thus generalizing the scope of the alignment methodology to include non-sequential protein alignments. We employ derivative-free optimization methodologies for searching for the global optimum of the highly nonlinear and non-differentiable RMSD function encountered in the proposed model. Alignments obtained with SAS-Pro have better RMSD values and larger lengths than those obtained from other alignment tools. For non-sequential alignment problems, SAS-Pro leads to alignments with high degree of similarity with known reference alignments. The source code of SAS-Pro is available for download at http://eudoxus.cheme.cmu.edu/saspro/SAS-Pro.html.
GPU-based Point Cloud Superpositioning for Structural Comparisons of Protein Binding Sites.
Leinweber, Matthias; Fober, Thomas; Freisleben, Bernd
2016-11-07
In this paper, we present a novel approach to solve the labeled point cloud superpositioning problem for performing structural comparisons of protein binding sites. The solution is based on a parallel evolution strategy that operates on large populations and runs on GPU hardware. The proposed evolution strategy reduces the likelihood of getting stuck in a local optimum of the multimodal real-valued optimization problem represented by labeled point cloud superpositioning. The performance of the GPU-based parallel evolution strategy is compared to a previously proposed CPU-based sequential approach for labeled point cloud superpositioning, indicating that the GPU-based parallel evolution strategy leads to qualitatively better results and significantly shorter runtimes, with speed improvements of up to a factor of 1,500 for large populations. Binary classification tests based on the ATP, NADH and FAD protein subsets of CavBase, a database containing putative binding sites, show average classification rate improvements from about 92% (CPU) to 96% (GPU). Further experiments indicate that the proposed GPU-based labeled point cloud superpositioning approach can be superior to traditional protein comparison approaches based on sequence alignments.
Helmich, Benjamin; Sierka, Marek
2012-01-15
An algorithm for similarity recognition of molecules and molecular clusters is presented which also establishes the optimum matching among atoms of different structures. In the first step of the algorithm, a set of molecules are coarsely superimposed by transforming them into a common reference coordinate system. The optimum atomic matching among structures is then found with the help of the Hungarian algorithm. For this, pairs of structures are represented as complete bipartite graphs with a weight function that uses intermolecular atomic distances. In the final step, a rotational superposition method is applied using the optimum atomic matching found. This yields the minimum root mean square deviation of intermolecular atomic distances with respect to arbitrary rotation and translation of the molecules. Combined with an effective similarity prescreening method, our algorithm shows robustness and an effective quadratic scaling of computational time with the number of atoms.
NASA Astrophysics Data System (ADS)
Martínez-Martos, Manuel; Galindo-Zaldivar, Jesús; Martínez-Moreno, Francisco José; Calvo-Rayo, Raquel; Sanz de Galdeano, Carlos
2017-01-01
The relief of the Betic Cordillera was formed since the late Serravallian inducing the development of intramontane basins. The Alhabia basin, situated in the central part of the Internal Zones, is located at the intersection of the Alpujarran Corridor, the Tabernas basin, both trending E-W, and the NW-SE oriented Gádor-Almería basin. The geometry of the basin has been constrained by new gravity data. The basin is limited to the North by the Sierra de Filabres and Sierra Nevada antiforms that started to develop in Serravallian times under N-S shortening and to the south by Sierra Alhamilla and Sierra de Gádor antiforms. Plate convergence in the region rotated counter-clockwise in Tortonian times favouring the formation of E-W dextral faults. In this setting, NE-SW extension, orthogonal to the shortening direction, was accommodated by normal faults on the SW edge of Sierra Alhamilla. The Alhabia basin shows a cross-shaped depocentre in the zone of synform and fault intersection. This field example serves to constrain recent counter-clockwise stress rotation during the latest stages of Neogene-Quaternary basin evolution in the Betic Cordillera Internal Zones and underlines the importance of studying the basins' deep structure and its relation with the tectonic structures interactions.
NASA Astrophysics Data System (ADS)
Sadovskii, V. M.; Sadovskaya, O. V.
2016-10-01
The Tarasov fan-shaped mechanism, simulating the formation of shear ruptures in a brittle rock at stress conditions corresponding to seismogenic depths, is analyzed. For computation of the stress-strain state of a rock near the equilibrium fan-structure the original method is constructed. The fault is modeled as a narrow elongated layer, filled with the domino-blocks, between two elastic half-spaces. Displacements and stresses around the fan are represented in the integral form as a superposition of edge dislocations with an unknown function of distribution of the Burgers vector. To take into account the stresses of lateral thrust, the solution of plane problem of the elasticity is used for a tensile crack, on the surfaces of which the previously unknown normal stresses are distributed. The exact formulation of the problem leads to a system of two nonlinear singular integral equations, which is solved numerically by the method of successive approximations. The obtained solution is used, when setting the initial data in computations of the dynamics of the Tarasov fan-shaped mechanism. With the help of this solution the discontinuous nature of shear ruptures, observed in natural and laboratory experiments, is explained.
Analytical ultrasonics for structural materials
NASA Technical Reports Server (NTRS)
Kupperman, D. S.
1986-01-01
The application of ultrasonic velocity and attenuation measurements to characterize the microstructure of structural materials is discussed. Velocity measurements in cast stainless steel are correlated with microstructural variations ranging from equiaxed (elastically isotropic) to columnar (elastically anisotropic) grain structure. The effect of the anisotropic grain structure on the deviation of ultrasonic waves in cast stainless steel is also reported. Field-implementable techniques for distinguishing equiaxed from columnar grain structures in cast strainless steel structural members are presented. The application of ultrasonic velocity measurements to characterize structural ceramics in the green state is also discussed.
Superpositions of probability distributions
NASA Astrophysics Data System (ADS)
Jizba, Petr; Kleinert, Hagen
2008-09-01
Probability distributions which can be obtained from superpositions of Gaussian distributions of different variances v=σ2 play a favored role in quantum theory and financial markets. Such superpositions need not necessarily obey the Chapman-Kolmogorov semigroup relation for Markovian processes because they may introduce memory effects. We derive the general form of the smearing distributions in v which do not destroy the semigroup property. The smearing technique has two immediate applications. It permits simplifying the system of Kramers-Moyal equations for smeared and unsmeared conditional probabilities, and can be conveniently implemented in the path integral calculus. In many cases, the superposition of path integrals can be evaluated much easier than the initial path integral. Three simple examples are presented, and it is shown how the technique is extended to quantum mechanics.
Network Class Superposition Analyses
Pearson, Carl A. B.; Zeng, Chen; Simha, Rahul
2013-01-01
Networks are often used to understand a whole system by modeling the interactions among its pieces. Examples include biomolecules in a cell interacting to provide some primary function, or species in an environment forming a stable community. However, these interactions are often unknown; instead, the pieces' dynamic states are known, and network structure must be inferred. Because observed function may be explained by many different networks (e.g., for the yeast cell cycle process [1]), considering dynamics beyond this primary function means picking a single network or suitable sample: measuring over all networks exhibiting the primary function is computationally infeasible. We circumvent that obstacle by calculating the network class ensemble. We represent the ensemble by a stochastic matrix , which is a transition-by-transition superposition of the system dynamics for each member of the class. We present concrete results for derived from Boolean time series dynamics on networks obeying the Strong Inhibition rule, by applying to several traditional questions about network dynamics. We show that the distribution of the number of point attractors can be accurately estimated with . We show how to generate Derrida plots based on . We show that -based Shannon entropy outperforms other methods at selecting experiments to further narrow the network structure. We also outline an experimental test of predictions based on . We motivate all of these results in terms of a popular molecular biology Boolean network model for the yeast cell cycle, but the methods and analyses we introduce are general. We conclude with open questions for , for example, application to other models, computational considerations when scaling up to larger systems, and other potential analyses. PMID:23565141
Network class superposition analyses.
Pearson, Carl A B; Zeng, Chen; Simha, Rahul
2013-01-01
Networks are often used to understand a whole system by modeling the interactions among its pieces. Examples include biomolecules in a cell interacting to provide some primary function, or species in an environment forming a stable community. However, these interactions are often unknown; instead, the pieces' dynamic states are known, and network structure must be inferred. Because observed function may be explained by many different networks (e.g., ≈ 10(30) for the yeast cell cycle process), considering dynamics beyond this primary function means picking a single network or suitable sample: measuring over all networks exhibiting the primary function is computationally infeasible. We circumvent that obstacle by calculating the network class ensemble. We represent the ensemble by a stochastic matrix T, which is a transition-by-transition superposition of the system dynamics for each member of the class. We present concrete results for T derived from boolean time series dynamics on networks obeying the Strong Inhibition rule, by applying T to several traditional questions about network dynamics. We show that the distribution of the number of point attractors can be accurately estimated with T. We show how to generate Derrida plots based on T. We show that T-based Shannon entropy outperforms other methods at selecting experiments to further narrow the network structure. We also outline an experimental test of predictions based on T. We motivate all of these results in terms of a popular molecular biology boolean network model for the yeast cell cycle, but the methods and analyses we introduce are general. We conclude with open questions for T, for example, application to other models, computational considerations when scaling up to larger systems, and other potential analyses.
Transient Response of Shells of Revolution by Direct Integration and Modal Superposition Methods
NASA Technical Reports Server (NTRS)
Stephens, W. B.; Adelman, H. M.
1974-01-01
The results of an analytical effort to obtain and evaluate transient response data for a cylindrical and a conical shell by use of two different approaches: direct integration and modal superposition are described. The inclusion of nonlinear terms is more important than the inclusion of secondary linear effects (transverse shear deformation and rotary inertia) although there are thin-shell structures where these secondary effects are important. The advantages of the direct integration approach are that geometric nonlinear and secondary effects are easy to include and high-frequency response may be calculated. In comparison to the modal superposition technique the computer storage requirements are smaller. The advantages of the modal superposition approach are that the solution is independent of the previous time history and that once the modal data are obtained, the response for repeated cases may be efficiently computed. Also, any admissible set of initial conditions can be applied.
Goerigk, Lars; Collyer, Charles A; Reimers, Jeffrey R
2014-12-18
We demonstrate the importance of properly accounting for London dispersion and basis-set-superposition error (BSSE) in quantum-chemical optimizations of protein structures, factors that are often still neglected in contemporary applications. We optimize a portion of an ensemble of conformationally flexible lysozyme structures obtained from highly accurate X-ray crystallography data that serve as a reliable benchmark. We not only analyze root-mean-square deviations from the experimental Cartesian coordinates, but also, for the first time, demonstrate how London dispersion and BSSE influence crystallographic R factors. Our conclusions parallel recent recommendations for the optimization of small gas-phase peptide structures made by some of the present authors: Hartree-Fock theory extended with Grimme's recent dispersion and BSSE corrections (HF-D3-gCP) is superior to popular density functional theory (DFT) approaches. Not only are statistical errors on average lower with HF-D3-gCP, but also the convergence behavior is much better. In particular, we show that the BP86/6-31G* approach should not be relied upon as a black-box method, despite its widespread use, as its success is based on an unpredictable cancellation of errors. Using HF-D3-gCP is technically straightforward, and we therefore encourage users of quantum-chemical methods to adopt this approach in future applications.
Medwedeff, D.A. ); Lin, Joseph, T.C.; Carr, T.R.; Stafford, J.M. )
1993-02-01
Seven balanced cross sections document the structural fabric of the San Emigdio Mountains and the adjacent San Joaquin Valley. Major tectonic elements are (1) the Los Lobos normal fault (LLF), (2) the White Wolf reverse fault (WWF), and (3) the Pleito fold-and-thrust belt (PTFB). The Oligo-Miocene LLF system created the distinction between the San Joaquin basin to the north and the Tejon platform to the south. Superposed on the LLF is the younger WWF which has further uplifted the Tejon platform. Along strike, the WWF alternately rotates, truncates, and overrides the LU. The even younger low-angle PTFB is primarily developed on the Tejon platform, but locally interferes both the LLF and WWf. Super position of these structures control the hydrocarbon traps. Wheeler Ridge field (73+MMBOE) is created by the superposition of the PFTB atop of pre-existing basement structures. The field produces from Eocene to late Miocene sands. Some sands are structurally controlled. Due to the complex structural setting, this 1922 field has been extended by discovery of additional reservoirs including a 1989 gas and condensate find in the Oligocene section. This success triggered our comprehensive structural reevaluation. Other fields along and south of the WWF trend are North Tejon (basement involved anticline; 56 MMBOE), Tejon (stratigraphic trap; 36 MMBOE) and Pleito (fault trap; 12 MMBOE) fields. The new structural model suggests two play types for exploration potential: (1) additional fault traps along the WWF trend; and (2) subthrust plays beneath the Pleito thrust. The prolific production history of the WWF trend and large structures mapped beneath the Pleito thrust bode well for future exploration in the San Emigdio Mountains area.
Analytical modeling of orthogonal spiral structures
NASA Astrophysics Data System (ADS)
Santos, Auteliano A.; Hobeck, Jared D.; Inman, Daniel J.
2016-11-01
This paper presents the analytical modeling of orthogonal spiral structures (OSS), a promising option for small-scale energy harvesting applications. This unique multi-beam structure is analyzed using a distributed parameter approach with Euler-Bernoulli assumptions. First, an aluminum substrate is evaluated to determine if the proposed design can be used to capture vibration energy in the desired frequency range using a twelve beam OSS. Finite element calculations are used to validate the analytical model. This model is then modified to include the electromechanical effects of a piezoelectric layer added to the aluminum substrate. Lastly, the effects of the beam width and the number of beams is analyzed for a particular surface area of the OSS. Results show that increasing the number of beams causes a reduction in the first natural frequency. From those results, it is possible to conclude that OSS can be used as an alternative to current energy harvesting systems for MEMS applications, allowing the capture of environmental energy in the frequency range of common mechanical systems.
NASA Astrophysics Data System (ADS)
Hayami, Satoru; Ozawa, Ryo; Motome, Yukitoshi
2016-07-01
Magnetic orders characterized by multiple ordering vectors harbor noncollinear and noncoplanar spin textures and can be a source of unusual electronic properties through the spin Berry phase mechanism. We theoretically show that such multiple-Q states are stabilized in itinerant magnets in the form of superpositions of collinear up-up-down-down (UUDD) spin states, which accompany the density waves of vector and scalar chirality. The result is drawn by examining the ground state of the Kondo lattice model with classical localized moments, especially when the Fermi surface is tuned to be partially nested by the symmetry-related commensurate vectors. We unveil the instability toward a double-Q UUDD state with vector chirality density waves on the square lattice and a triple-Q UUDD state with scalar chirality density waves on the triangular lattice, using the perturbative theory and variational calculations. The former double-Q state is also confirmed by large-scale Langevin dynamics simulations. We also show that, for a sufficiently large exchange coupling, the chirality density waves can induce rich nontrivial topology of electronic structures, such as the massless Dirac semimetal, Chern insulator with quantized topological Hall response, and peculiar edge states which depend on the phase of chirality density waves at the edges.
On the superposition principle in interference experiments
Sinha, Aninda; H. Vijay, Aravind; Sinha, Urbasi
2015-01-01
The superposition principle is usually incorrectly applied in interference experiments. This has recently been investigated through numerics based on Finite Difference Time Domain (FDTD) methods as well as the Feynman path integral formalism. In the current work, we have derived an analytic formula for the Sorkin parameter which can be used to determine the deviation from the application of the principle. We have found excellent agreement between the analytic distribution and those that have been earlier estimated by numerical integration as well as resource intensive FDTD simulations. The analytic handle would be useful for comparing theory with future experiments. It is applicable both to physics based on classical wave equations as well as the non-relativistic Schrödinger equation. PMID:25973948
Automated dynamic analytical model improvement for damped structures
NASA Technical Reports Server (NTRS)
Fuh, J. S.; Berman, A.
1985-01-01
A method is described to improve a linear nonproportionally damped analytical model of a structure. The procedure finds the smallest changes in the analytical model such that the improved model matches the measured modal parameters. Features of the method are: (1) ability to properly treat complex valued modal parameters of a damped system; (2) applicability to realistically large structural models; and (3) computationally efficiency without involving eigensolutions and inversion of a large matrix.
Combined experimental/analytical modeling of shell/payload structures
Martinez, D.R.; Miller, A.K.; Carne, T.G.
1985-12-01
This study evaluates the accuracy of computed modal frequencies obtained from a combined experimental/analytical model of a shell/payload structure. A component mode synthesis technique was used which incorporated free modes and residual effects. The total structure is physically divided into the two subsystems which are connected through stiff joints. The payload was tested to obtain its free-free modes, while a finite element model of the shell was analyzed to obtain its modal description. Both the translational and rotational components of the experimental mode shapes at the payload interface were used in the coupling. Sensitivity studies were also performed to determine the effect of neglecting the residual terms of the payload. Results from a previous study of a combined experimental/analytical model for a beam structure are also given. The beam structure was used to examine the basic procedures and difficulties in experimentally measuring, and analytically accounting for the rotational and residual quantities.
Macroscopic superposition of ultracold atoms with orbital degrees of freedom
Garcia-March, M. A.; Carr, L. D.; Dounas-Frazer, D. R.
2011-04-15
We introduce higher dimensions into the problem of Bose-Einstein condensates in a double-well potential, taking into account orbital angular momentum. We completely characterize the eigenstates of this system, delineating new regimes via both analytical high-order perturbation theory and numerical exact diagonalization. Among these regimes are mixed Josephson- and Fock-like behavior, crossings in both excited and ground states, and shadows of macroscopic superposition states.
Maximum Likelihood Estimation in Meta-Analytic Structural Equation Modeling
ERIC Educational Resources Information Center
Oort, Frans J.; Jak, Suzanne
2016-01-01
Meta-analytic structural equation modeling (MASEM) involves fitting models to a common population correlation matrix that is estimated on the basis of correlation coefficients that are reported by a number of independent studies. MASEM typically consist of two stages. The method that has been found to perform best in terms of statistical…
Analytic semigroups: Applications to inverse problems for flexible structures
NASA Technical Reports Server (NTRS)
Banks, H. T.; Rebnord, D. A.
1990-01-01
Convergence and stability results for least squares inverse problems involving systems described by analytic semigroups are presented. The practical importance of these results is demonstrated by application to several examples from problems of estimation of material parameters in flexible structures using accelerometer data.
Fitting Meta-Analytic Structural Equation Models with Complex Datasets
ERIC Educational Resources Information Center
Wilson, Sandra Jo; Polanin, Joshua R.; Lipsey, Mark W.
2016-01-01
A modification of the first stage of the standard procedure for two-stage meta-analytic structural equation modeling for use with large complex datasets is presented. This modification addresses two common problems that arise in such meta-analyses: (a) primary studies that provide multiple measures of the same construct and (b) the correlation…
A Meta-analytic Review of Family Structure Stereotypes.
ERIC Educational Resources Information Center
Ganong, Lawrence H.; And Others
1990-01-01
A meta-analytic review examined 26 research studies on stereotypes related to family structure. Three hypotheses were explored: that married adults, parents, and children of married parents are all perceived more favorably than their single, nonparent, or child-of-single-parent counterparts. For all three comparisons, traditional nuclear family…
Creating a Superposition of Unknown Quantum States.
Oszmaniec, Michał; Grudka, Andrzej; Horodecki, Michał; Wójcik, Antoni
2016-03-18
The superposition principle is one of the landmarks of quantum mechanics. The importance of quantum superpositions provokes questions about the limitations that quantum mechanics itself imposes on the possibility of their generation. In this work, we systematically study the problem of the creation of superpositions of unknown quantum states. First, we prove a no-go theorem that forbids the existence of a universal probabilistic quantum protocol producing a superposition of two unknown quantum states. Second, we provide an explicit probabilistic protocol generating a superposition of two unknown states, each having a fixed overlap with the known referential pure state. The protocol can be applied to generate coherent superposition of results of independent runs of subroutines in a quantum computer. Moreover, in the context of quantum optics it can be used to efficiently generate highly nonclassical states or non-Gaussian states.
Mesoscopic Superposition States in Relativistic Landau Levels
Bermudez, A.; Martin-Delgado, M. A.; Solano, E.
2007-09-21
We show that a linear superposition of mesoscopic states in relativistic Landau levels can be built when an external magnetic field couples to a relativistic spin 1/2 charged particle. Under suitable initial conditions, the associated Dirac equation produces unitarily superpositions of coherent states involving the particle orbital quanta in a well-defined mesoscopic regime. We demonstrate that these mesoscopic superpositions have a purely relativistic origin and disappear in the nonrelativistic limit.
Communication: Two measures of isochronal superposition
NASA Astrophysics Data System (ADS)
Roed, Lisa Anita; Gundermann, Ditte; Dyre, Jeppe C.; Niss, Kristine
2013-09-01
A liquid obeys isochronal superposition if its dynamics is invariant along the isochrones in the thermodynamic phase diagram (the curves of constant relaxation time). This paper introduces two quantitative measures of isochronal superposition. The measures are used to test the following six liquids for isochronal superposition: 1,2,6 hexanetriol, glycerol, polyphenyl ether, diethyl phthalate, tetramethyl tetraphenyl trisiloxane, and dibutyl phthalate. The latter four van der Waals liquids obey isochronal superposition to a higher degree than the two hydrogen-bonded liquids. This is a prediction of the isomorph theory, and it confirms findings by other groups.
Superposition and alignment of labeled point clouds.
Fober, Thomas; Glinca, Serghei; Klebe, Gerhard; Hüllermeier, Eyke
2011-01-01
Geometric objects are often represented approximately in terms of a finite set of points in three-dimensional euclidean space. In this paper, we extend this representation to what we call labeled point clouds. A labeled point cloud is a finite set of points, where each point is not only associated with a position in three-dimensional space, but also with a discrete class label that represents a specific property. This type of model is especially suitable for modeling biomolecules such as proteins and protein binding sites, where a label may represent an atom type or a physico-chemical property. Proceeding from this representation, we address the question of how to compare two labeled points clouds in terms of their similarity. Using fuzzy modeling techniques, we develop a suitable similarity measure as well as an efficient evolutionary algorithm to compute it. Moreover, we consider the problem of establishing an alignment of the structures in the sense of a one-to-one correspondence between their basic constituents. From a biological point of view, alignments of this kind are of great interest, since mutually corresponding molecular constituents offer important information about evolution and heredity, and can also serve as a means to explain a degree of similarity. In this paper, we therefore develop a method for computing pairwise or multiple alignments of labeled point clouds. To this end, we proceed from an optimal superposition of the corresponding point clouds and construct an alignment which is as much as possible in agreement with the neighborhood structure established by this superposition. We apply our methods to the structural analysis of protein binding sites.
Multipartite cellular automata and the superposition principle
NASA Astrophysics Data System (ADS)
Elze, Hans-Thomas
2016-05-01
Cellular automata (CA) can show well known features of quantum mechanics (QM), such as a linear updating rule that resembles a discretized form of the Schrödinger equation together with its conservation laws. Surprisingly, a whole class of “natural” Hamiltonian CA, which are based entirely on integer-valued variables and couplings and derived from an action principle, can be mapped reversibly to continuum models with the help of sampling theory. This results in “deformed” quantum mechanical models with a finite discreteness scale l, which for l→0 reproduce the familiar continuum limit. Presently, we show, in particular, how such automata can form “multipartite” systems consistently with the tensor product structures of non-relativistic many-body QM, while maintaining the linearity of dynamics. Consequently, the superposition principle is fully operative already on the level of these primordial discrete deterministic automata, including the essential quantum effects of interference and entanglement.
Nucleic Acid i-Motif Structures in Analytical Chemistry.
Alba, Joan Josep; Sadurní, Anna; Gargallo, Raimundo
2016-09-02
Under the appropriate experimental conditions of pH and temperature, cytosine-rich segments in DNA or RNA sequences may produce a characteristic folded structure known as an i-motif. Besides its potential role in vivo, which is still under investigation, this structure has attracted increasing interest in other fields due to its sharp, fast and reversible pH-driven conformational changes. This "on/off" switch at molecular level is being used in nanotechnology and analytical chemistry to develop nanomachines and sensors, respectively. This paper presents a review of the latest applications of this structure in the field of chemical analysis.
Structurally compliant rocket engine combustion chamber: Experimental and analytical validation
NASA Technical Reports Server (NTRS)
Jankovsky, Robert S.; Arya, Vinod K.; Kazaroff, John M.; Halford, Gary R.
1994-01-01
A new, structurally compliant rocket engine combustion chamber design has been validated through analysis and experiment. Subscale, tubular channel chambers have been cyclically tested and analytically evaluated. Cyclic lives were determined to have a potential for 1000 percent increase over those of rectangular channel designs, the current state of the art. Greater structural compliance in the circumferential direction gave rise to lower thermal strains during hot firing, resulting in lower thermal strain ratcheting and longer predicted fatigue lives. Thermal, structural, and durability analyses of the combustion chamber design, involving cyclic temperatures, strains, and low-cycle fatigue lives, have corroborated the experimental observations.
Analytical studies of spectrum broadcast structures in quantum Brownian motion
NASA Astrophysics Data System (ADS)
Tuziemski, J.; Korbicz, J. K.
2016-11-01
Spectrum broadcast structures are a new and fresh concept in the quantum-to-classical transition, introduced recently in the context of decoherence and the appearance of objective features in quantum mechanics. These are specific quantum state structures, responsible for the objectivization of the decohered state of a system. Recently, they have been demonstrated by means of the well-known quantum Brownian motion model of the recoilless limit (infinitely massive central system), as the principal interest lies in information transfer from the system to the environment. However, a final analysis relied on numerics. Here, after a presentation of the main concepts, we perform analytical studies of the model, showing the timescales and the efficiency of the spectrum broadcast structure formation. We consider a somewhat simplified environment, being random with a uniform distribution of frequencies.
A reciprocal space approach for locating symmetry elements in Patterson superposition maps
Hendrixson, T.
1990-09-21
A method for determining the location and possible existence of symmetry elements in Patterson superposition maps has been developed. A comparison of the original superposition map and a superposition map operated on by the symmetry element gives possible translations to the location of the symmetry element. A reciprocal space approach using structure factor-like quantities obtained from the Fourier transform of the superposition function is then used to determine the best'' location of the symmetry element. Constraints based upon the space group requirements are also used as a check on the locations. The locations of the symmetry elements are used to modify the Fourier transform coefficients of the superposition function to give an approximation of the structure factors, which are then refined using the EG relation. The analysis of several compounds using this method is presented. Reciprocal space techniques for locating multiple images in the superposition function are also presented, along with methods to remove the effect of multiple images in the Fourier transform coefficients of the superposition map. In addition, crystallographic studies of the extended chain structure of (NHC{sub 5}H{sub 5})SbI{sub 4} and of the twinning method of the orthorhombic form of the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} are presented. 54 refs.
Maximum likelihood estimation in meta-analytic structural equation modeling.
Oort, Frans J; Jak, Suzanne
2016-06-01
Meta-analytic structural equation modeling (MASEM) involves fitting models to a common population correlation matrix that is estimated on the basis of correlation coefficients that are reported by a number of independent studies. MASEM typically consist of two stages. The method that has been found to perform best in terms of statistical properties is the two-stage structural equation modeling, in which maximum likelihood analysis is used to estimate the common correlation matrix in the first stage, and weighted least squares analysis is used to fit structural equation models to the common correlation matrix in the second stage. In the present paper, we propose an alternative method, ML MASEM, that uses ML estimation throughout. In a simulation study, we use both methods and compare chi-square distributions, bias in parameter estimates, false positive rates, and true positive rates. Both methods appear to yield unbiased parameter estimates and false and true positive rates that are close to the expected values. ML MASEM parameter estimates are found to be significantly less bias than two-stage structural equation modeling estimates, but the differences are very small. The choice between the two methods may therefore be based on other fundamental or practical arguments. Copyright © 2016 John Wiley & Sons, Ltd.
Fitting meta-analytic structural equation models with complex datasets.
Wilson, Sandra Jo; Polanin, Joshua R; Lipsey, Mark W
2016-06-01
A modification of the first stage of the standard procedure for two-stage meta-analytic structural equation modeling for use with large complex datasets is presented. This modification addresses two common problems that arise in such meta-analyses: (a) primary studies that provide multiple measures of the same construct and (b) the correlation coefficients that exhibit substantial heterogeneity, some of which obscures the relationships between the constructs of interest or undermines the comparability of the correlations across the cells. One component of this approach is a three-level random effects model capable of synthesizing a pooled correlation matrix with dependent correlation coefficients. Another component is a meta-regression that can be used to generate covariate-adjusted correlation coefficients that reduce the influence of selected unevenly distributed moderator variables. A non-technical presentation of these techniques is given, along with an illustration of the procedures with a meta-analytic dataset. Copyright © 2016 John Wiley & Sons, Ltd.
Semi Active Control of Civil Structures, Analytical and Numerical Studies
NASA Astrophysics Data System (ADS)
Kerboua, M.; Benguediab, M.; Megnounif, A.; Benrahou, K. H.; Kaoulala, F.
numerical example of the parallel R-L piezoelectric vibration shunt control simulated with MATLAB® is presented. An analytical study of the resistor-inductor (R-L) passive piezoelectric vibration shunt control of a cantilever beam was undertaken. The modal and strain analyses were performed by varying the material properties and geometric configurations of the piezoelectric transducer in relation to the structure in order to maximize the mechanical strain produced in the piezoelectric transducer.
The Developmental Rules of Neural Superposition in Drosophila.
Langen, Marion; Agi, Egemen; Altschuler, Dylan J; Wu, Lani F; Altschuler, Steven J; Hiesinger, Peter Robin
2015-07-02
Complicated neuronal circuits can be genetically encoded, but the underlying developmental algorithms remain largely unknown. Here, we describe a developmental algorithm for the specification of synaptic partner cells through axonal sorting in the Drosophila visual map. Our approach combines intravital imaging of growth cone dynamics in developing brains of intact pupae and data-driven computational modeling. These analyses suggest that three simple rules are sufficient to generate the seemingly complex neural superposition wiring of the fly visual map without an elaborate molecular matchmaking code. Our computational model explains robust and precise wiring in a crowded brain region despite extensive growth cone overlaps and provides a framework for matching molecular mechanisms with the rules they execute. Finally, ordered geometric axon terminal arrangements that are not required for neural superposition are a side product of the developmental algorithm, thus elucidating neural circuit connectivity that remained unexplained based on adult structure and function alone.
Experimental superposition of orders of quantum gates.
Procopio, Lorenzo M; Moqanaki, Amir; Araújo, Mateus; Costa, Fabio; Alonso Calafell, Irati; Dowd, Emma G; Hamel, Deny R; Rozema, Lee A; Brukner, Časlav; Walther, Philip
2015-08-07
Quantum computers achieve a speed-up by placing quantum bits (qubits) in superpositions of different states. However, it has recently been appreciated that quantum mechanics also allows one to 'superimpose different operations'. Furthermore, it has been shown that using a qubit to coherently control the gate order allows one to accomplish a task--determining if two gates commute or anti-commute--with fewer gate uses than any known quantum algorithm. Here we experimentally demonstrate this advantage, in a photonic context, using a second qubit to control the order in which two gates are applied to a first qubit. We create the required superposition of gate orders by using additional degrees of freedom of the photons encoding our qubits. The new resource we exploit can be interpreted as a superposition of causal orders, and could allow quantum algorithms to be implemented with an efficiency unlikely to be achieved on a fixed-gate-order quantum computer.
Experimental superposition of orders of quantum gates
Procopio, Lorenzo M.; Moqanaki, Amir; Araújo, Mateus; Costa, Fabio; Alonso Calafell, Irati; Dowd, Emma G.; Hamel, Deny R.; Rozema, Lee A.; Brukner, Časlav; Walther, Philip
2015-01-01
Quantum computers achieve a speed-up by placing quantum bits (qubits) in superpositions of different states. However, it has recently been appreciated that quantum mechanics also allows one to ‘superimpose different operations'. Furthermore, it has been shown that using a qubit to coherently control the gate order allows one to accomplish a task—determining if two gates commute or anti-commute—with fewer gate uses than any known quantum algorithm. Here we experimentally demonstrate this advantage, in a photonic context, using a second qubit to control the order in which two gates are applied to a first qubit. We create the required superposition of gate orders by using additional degrees of freedom of the photons encoding our qubits. The new resource we exploit can be interpreted as a superposition of causal orders, and could allow quantum algorithms to be implemented with an efficiency unlikely to be achieved on a fixed-gate-order quantum computer. PMID:26250107
a Logical Account of Quantum Superpositions
NASA Astrophysics Data System (ADS)
Krause, Décio Arenhart, Jonas R. Becker
In this paper we consider the phenomenon of superpositions in quantum mechanics and suggest a way to deal with the idea in a logical setting from a syntactical point of view, that is, as subsumed in the language of the formalism, and not semantically. We restrict the discussion to the propositional level only. Then, after presenting the motivations and a possible world semantics, the formalism is outlined and we also consider within this scheme the claim that superpositions may involve contradictions, as in the case of the Schrödinger's cat, which (it is usually said) is both alive and dead. We argue that this claim is a misreading of the quantum case. Finally, we sketch a new form of quantum logic that involves three kinds of negations and present the relationships among them. The paper is a first approach to the subject, introducing some main guidelines to be developed by a `syntactical' logical approach to quantum superpositions.
On the Use of Material-Dependent Damping in ANSYS for Mode Superposition Transient Analysis
Nie, J.; Wei, X.
2011-07-17
The mode superposition method is often used for dynamic analysis of complex structures, such as the seismic Category I structures in nuclear power plants, in place of the less efficient full method, which uses the full system matrices for calculation of the transient responses. In such applications, specification of material-dependent damping is usually desirable because complex structures can consist of multiple types of materials that may have different energy dissipation capabilities. A recent review of the ANSYS manual for several releases found that the use of material-dependent damping is not clearly explained for performing a mode superposition transient dynamic analysis. This paper includes several mode superposition transient dynamic analyses using different ways to specify damping in ANSYS, in order to determine how material-dependent damping can be specified conveniently in a mode superposition transient dynamic analysis.
Large energy superpositions via Rydberg dressing
NASA Astrophysics Data System (ADS)
Khazali, Mohammadsadegh; Lau, Hon Wai; Humeniuk, Adam; Simon, Christoph
2016-08-01
We propose to create superposition states of over 100 strontium atoms in a ground state or metastable optical clock state using the Kerr-type interaction due to Rydberg state dressing in an optical lattice. The two components of the superposition can differ by an order of 300 eV in energy, allowing tests of energy decoherence models with greatly improved sensitivity. We take into account the effects of higher-order nonlinearities, spatial inhomogeneity of the interaction, decay from the Rydberg state, collective many-body decoherence, atomic motion, molecular formation, and diminishing Rydberg level separation for increasing principal number.
Analytic PRISM theory of structurally asymmetric polymer blends and copolymers
Schweizer, K.S. )
1993-10-25
Analytic PRISM theory with the new molecular closures is applied to determine the effective chi-parameters and spinodal instability curves for structurally asymmetric polymer alloys. Compressibility effects are found to be very important, and the use of a literal incompressible RPA-like approximation is shown to incur qualitative errors in most cases. A rich and nonadditive dependence of phase transition temperatures and apparent SANS chi-parameters on backbone stiffness asymmetry, attractive interaction potential asymmetry, and thermodynamic variables is found for binary homopolymer blends. A novel strategy for designing miscible mixtures based on a cancellation, or compensation, of the relevant asymmetries is identified. The influence of chain stiffness asymmetry in blends characterized by specific interactions is also studied. Generalization of the analytic PRISM theory to mixtures of random copolymers and periodic block copolymer melts is presented. All the rich behavior predicted for phase-separating homopolymer mixtures is again found for these systems, plus additional non mean field effects associated with random copolymer composition and block architecture. The theory is applied semiquantitatively to interpret recent experiments on polyolefin blends, diblock copolymers, and random copolymer alloys. Theoretical predictions are made which qualitatively account for recent experimental observations of a strong influence of stiffness asymmetry on phase separation temperatures, and the breakdown of the mean field random copolymer approach. Anomalous behavior is also predicted for deuterated mixtures due to an interference between the consequences of stiffness asymmetry and enthalipic interactions. The physical mechanism for the many non-Flory-Huggins effects predicted by the compressible PRISM theory is local, scalar density correlations, which appears to be different than the nematic fluctuation mechanism suggested by recent field theoretic work.
The Evolution and Development of Neural Superposition
Agi, Egemen; Langen, Marion; Altschuler, Steven J.; Wu, Lani F.; Zimmermann, Timo
2014-01-01
Visual systems have a rich history as model systems for the discovery and understanding of basic principles underlying neuronal connectivity. The compound eyes of insects consist of up to thousands of small unit eyes that are connected by photoreceptor axons to set up a visual map in the brain. The photoreceptor axon terminals thereby represent neighboring points seen in the environment in neighboring synaptic units in the brain. Neural superposition is a special case of such a wiring principle, where photoreceptors from different unit eyes that receive the same input converge upon the same synaptic units in the brain. This wiring principle is remarkable, because each photoreceptor in a single unit eye receives different input and each individual axon, among thousands others in the brain, must be sorted together with those few axons that have the same input. Key aspects of neural superposition have been described as early as 1907. Since then neuroscientists, evolutionary and developmental biologists have been fascinated by how such a complicated wiring principle could evolve, how it is genetically encoded, and how it is developmentally realized. In this review article, we will discuss current ideas about the evolutionary origin and developmental program of neural superposition. Our goal is to identify in what way the special case of neural superposition can help us answer more general questions about the evolution and development of genetically “hard-wired” synaptic connectivity in the brain. PMID:24912630
The principle of superposition in human prehension
Zatsiorsky, Vladimir M.; Latash, Mark L.; Gao, Fan; Shim, Jae Kun
2010-01-01
SUMMARY The experimental evidence supports the validity of the principle of superposition for multi-finger prehension in humans. Forces and moments of individual digits are defined by two independent commands: “Grasp the object stronger/weaker to prevent slipping” and “Maintain the rotational equilibrium of the object”. The effects of the two commands are summed up. PMID:20186284
The principle of superposition in human prehension.
Zatsiorsky, Vladimir M; Latash, Mark L; Gao, Fan; Shim, Jae Kun
2004-03-01
The experimental evidence supports the validity of the principle of superposition for multi-finger prehension in humans. Forces and moments of individual digits are defined by two independent commands: "Grasp the object stronger/weaker to prevent slipping" and "Maintain the rotational equilibrium of the object". The effects of the two commands are summed up.
The evolution and development of neural superposition.
Agi, Egemen; Langen, Marion; Altschuler, Steven J; Wu, Lani F; Zimmermann, Timo; Hiesinger, Peter Robin
2014-01-01
Visual systems have a rich history as model systems for the discovery and understanding of basic principles underlying neuronal connectivity. The compound eyes of insects consist of up to thousands of small unit eyes that are connected by photoreceptor axons to set up a visual map in the brain. The photoreceptor axon terminals thereby represent neighboring points seen in the environment in neighboring synaptic units in the brain. Neural superposition is a special case of such a wiring principle, where photoreceptors from different unit eyes that receive the same input converge upon the same synaptic units in the brain. This wiring principle is remarkable, because each photoreceptor in a single unit eye receives different input and each individual axon, among thousands others in the brain, must be sorted together with those few axons that have the same input. Key aspects of neural superposition have been described as early as 1907. Since then neuroscientists, evolutionary and developmental biologists have been fascinated by how such a complicated wiring principle could evolve, how it is genetically encoded, and how it is developmentally realized. In this review article, we will discuss current ideas about the evolutionary origin and developmental program of neural superposition. Our goal is to identify in what way the special case of neural superposition can help us answer more general questions about the evolution and development of genetically "hard-wired" synaptic connectivity in the brain.
SUPERPOSITION OF POLYTROPES IN THE INNER HELIOSHEATH
Livadiotis, G.
2016-03-15
This paper presents a possible generalization of the equation of state and Bernoulli's integral when a superposition of polytropic processes applies in space and astrophysical plasmas. The theory of polytropic thermodynamic processes for a fixed polytropic index is extended for a superposition of polytropic indices. In general, the superposition may be described by any distribution of polytropic indices, but emphasis is placed on a Gaussian distribution. The polytropic density–temperature relation has been used in numerous analyses of space plasma data. This linear relation on a log–log scale is now generalized to a concave-downward parabola that is able to describe the observations better. The model of the Gaussian superposition of polytropes is successfully applied in the proton plasma of the inner heliosheath. The estimated mean polytropic index is near zero, indicating the dominance of isobaric thermodynamic processes in the sheath, similar to other previously published analyses. By computing Bernoulli's integral and applying its conservation along the equator of the inner heliosheath, the magnetic field in the inner heliosheath is estimated, B ∼ 2.29 ± 0.16 μG. The constructed normalized histogram of the values of the magnetic field is similar to that derived from a different method that uses the concept of large-scale quantization, bringing incredible insights to this novel theory.
Analytic structure of eigenvalues of coupled quantum systems
NASA Astrophysics Data System (ADS)
Bender, Carl M.; Felski, Alexander; Hassanpour, Nima; Klevansky, S. P.; Beygi, Alireza
2017-01-01
By analytically continuing the coupling constant g of a coupled quantum theory, one can, at least in principle, arrive at a state whose energy is lower than the ground state of the theory. The idea is to begin with the uncoupled g = 0 theory in its ground state, to analytically continue around an exceptional point (square-root singularity) in the complex-coupling-constant plane, and finally to return to the point g = 0. In the course of this analytic continuation, the uncoupled theory ends up in an unconventional state whose energy is lower than the original ground-state energy. However, it is unclear whether one can use this analytic continuation to extract energy from the conventional vacuum state; this process appears to be exothermic but one must do work to vary the coupling constant g.
Macroscopic Quantum Superposition in Cavity Optomechanics
NASA Astrophysics Data System (ADS)
Liao, Jie-Qiao; Tian, Lin
Quantum superposition in mechanical systems is not only a key evidence of macroscopic quantum coherence, but can also be utilized in modern quantum technology. Here we propose an efficient approach for creating macroscopically distinct mechanical superposition states in a two-mode optomechanical system. Photon hopping between the two cavity-modes is modulated sinusoidally. The modulated photon tunneling enables an ultrastrong radiation-pressure force acting on the mechanical resonator, and hence significantly increases the mechanical displacement induced by a single photon. We present systematic studies on the generation of the Yurke-Stoler-like states in the presence of system dissipations. The state generation method is general and it can be implemented with either optomechanical or electromechanical systems. The authors are supported by the National Science Foundation under Award No. NSF-DMR-0956064 and the DARPA ORCHID program through AFOSR.
Predicting jet radius in electrospinning by superpositioning exponential functions
NASA Astrophysics Data System (ADS)
Widartiningsih, P. M.; Iskandar, F.; Munir, M. M.; Viridi, S.
2016-08-01
This paper presents an analytical study of the correlation between viscosity and fiber diameter in electrospinning. Control over fiber diameter in electrospinning process was important since it will determine the performance of resulting nanofiber. Theoretically, fiber diameter was determined by surface tension, solution concentration, flow rate, and electric current. But experimentally it had been proven that significantly viscosity had an influence to fiber diameter. Jet radius equation in electrospinning process was divided into three areas: near the nozzle, far from the nozzle, and at jet terminal. There was no correlation between these equations. Superposition of exponential series model provides the equations combined into one, thus the entire of working parameters on electrospinning take a contribution to fiber diameter. This method yields the value of solution viscosity has a linear relation to jet radius. However, this method works only for low viscosity.
Toward quantum superposition of living organisms
NASA Astrophysics Data System (ADS)
Romero-Isart, Oriol; Juan, Mathieu L.; Quidant, Romain; Cirac, J. Ignacio
2010-03-01
The most striking feature of quantum mechanics is the existence of superposition states, where an object appears to be in different situations at the same time. The existence of such states has been previously tested with small objects, such as atoms, ions, electrons and photons (Zoller et al 2005 Eur. Phys. J. D 36 203-28), and even with molecules (Arndt et al 1999 Nature 401 680-2). More recently, it has been shown that it is possible to create superpositions of collections of photons (Deléglise et al 2008 Nature 455 510-14), atoms (Hammerer et al 2008 arXiv:0807.3358) or Cooper pairs (Friedman et al 2000 Nature 406 43-6). Very recent progress in optomechanical systems may soon allow us to create superpositions of even larger objects, such as micro-sized mirrors or cantilevers (Marshall et al 2003 Phys. Rev. Lett. 91 130401; Kippenberg and Vahala 2008 Science 321 1172-6 Marquardt and Girvin 2009 Physics 2 40; Favero and Karrai 2009 Nature Photon. 3 201-5), and thus to test quantum mechanical phenomena at larger scales. Here we propose a method to cool down and create quantum superpositions of the motion of sub-wavelength, arbitrarily shaped dielectric objects trapped inside a high-finesse cavity at a very low pressure. Our method is ideally suited for the smallest living organisms, such as viruses, which survive under low-vacuum pressures (Rothschild and Mancinelli 2001 Nature 406 1092-101) and optically behave as dielectric objects (Ashkin and Dziedzic 1987 Science 235 1517-20). This opens up the possibility of testing the quantum nature of living organisms by creating quantum superposition states in very much the same spirit as the original Schrödinger's cat 'gedanken' paradigm (Schrödinger 1935 Naturwissenschaften 23 807-12, 823-8, 844-9). We anticipate that our paper will be a starting point for experimentally addressing fundamental questions, such as the role of life and consciousness in quantum mechanics.
Analytical study of electronic structure in armchair graphene nanoribbons
NASA Astrophysics Data System (ADS)
Zheng, Huaixiu; Wang, Z. F.; Luo, Tao; Shi, Q. W.; Chen, Jie
2007-04-01
We present the analytical solution of the wave function and energy dispersion of armchair graphene nanoribbons (GNRs) based on the tight-binding approximation. By imposing the hard-wall boundary condition, we find that the wave vector in the confined direction is discretized. This discrete wave vector serves as the index of different subbands. Our analytical solutions of wave function and associated energy dispersion reproduce the results of numerical tight-binding and the solutions based on the k•p approximation. In addition, we also find that all armchair GNRs with edge deformation have energy gaps, which agrees with recently reported first-principles calculations.
Feature Extraction of High-Dimensional Structures for Exploratory Analytics
2013-04-01
development of a method to gain insight into HDD, particularly in the application of an analytic strategy to terrorist data. 15. SUBJECT TERMS...geodesic distance 4 (8); (3) the COIL-20 dataset; (4) word-features dataset; and (5) a Netflix dataset.* Although the manifold learners are
Laser superposition in multi-pass amplification process
NASA Astrophysics Data System (ADS)
Zhang, Ying; Liu, Lan-Qin; Wang, Wen-Yi; Huang, Wan-Qing; Geng, Yuan-Chao
2015-02-01
Physical model was established to describe the pulse superposition in multi-pass amplification process when the pulse reflected from the cavity mirror and the front and the end of the pulse encountered. Theoretical analysis indicates that pulse superposition will consume more inversion population than that consumed without superposition. The standing wave field will be formed when the front and the end of the pulse is coherent overlapped. The inversion population density is spatial hole-burning by the standing wave field. The pulse gain and pulse are affected by superposition. Based on this physical model, three conditions, without superposition, coherent superposition and incoherent superposition were compared. This study will give instructions for high power solid laser design.
On Kolmogorov's superpositions and Boolean functions
Beiu, V.
1998-12-31
The paper overviews results dealing with the approximation capabilities of neural networks, as well as bounds on the size of threshold gate circuits. Based on an explicit numerical (i.e., constructive) algorithm for Kolmogorov's superpositions they will show that for obtaining minimum size neutral networks for implementing any Boolean function, the activation function of the neurons is the identity function. Because classical AND-OR implementations, as well as threshold gate implementations require exponential size (in the worst case), it will follow that size-optimal solutions for implementing arbitrary Boolean functions require analog circuitry. Conclusions and several comments on the required precision are ending the paper.
Maximum predictive power and the superposition principle
NASA Technical Reports Server (NTRS)
Summhammer, Johann
1994-01-01
In quantum physics the direct observables are probabilities of events. We ask how observed probabilities must be combined to achieve what we call maximum predictive power. According to this concept the accuracy of a prediction must only depend on the number of runs whose data serve as input for the prediction. We transform each probability to an associated variable whose uncertainty interval depends only on the amount of data and strictly decreases with it. We find that for a probability which is a function of two other probabilities maximum predictive power is achieved when linearly summing their associated variables and transforming back to a probability. This recovers the quantum mechanical superposition principle.
Design of artificial spherical superposition compound eye
NASA Astrophysics Data System (ADS)
Cao, Zhaolou; Zhai, Chunjie; Wang, Keyi
2015-12-01
In this research, design of artificial spherical superposition compound eye is presented. The imaging system consists of three layers of lens arrays. In each channel, two lenses are designed to control the angular magnification and a field lens is added to improve the image quality and extend the field of view. Aspherical surfaces are introduced to improve the image quality. Ray tracing results demonstrate that the light from the same object point is focused at the same imaging point through different channels. Therefore the system has much higher energy efficiency than conventional spherical apposition compound eye.
NASA Astrophysics Data System (ADS)
Zhang, En-Tao; Ji, Xiao-Ling; Lü, Bai-Da
2009-02-01
The propagation properties of the off-axis superposition of partially coherent beams through atmospheric turbulence and their beam quality in terms of the mean-squared beam width w(z) and the power in the bucket (PIB) are studied in detail, where the effects of partial coherence, off-axis beam superposition and atmospheric turbulence are considered. The analytical expressions for the intensity, the beam width and the PIB are derived, and illustrative examples are given numerically. It is shown that the maximum intensity Imax and the PIB decrease and w(z) increases as the refraction index structure constant Cn2 increases. Therefore, the turbulence results in a degradation of the beam quality. However, the resulting partially coherent beam with a smaller value of spatial correlation parameter γ and larger values of separate distance xd and beam number M is less affected by the turbulence than that with a larger value of γ and smaller values of xd and M. The main results obtained in this paper are explained physically.
The analytic solution of the structural analysis problem and its use in structural synthesis
NASA Astrophysics Data System (ADS)
Fuchs, M. B.
An overview is presented of the analytic expressions for the inverse of the stiffness matrix, the nodal displacements, and the internal forces in linear elastic redundant structures. The inverse of the stiffness matrix and the nodal displacements are obtained using Binet and Cauchy's theorem on the product of compound matrices. The formula for the internal forces is derived from the principles of structural mechanics. This approach is shown to apply to all framed structures via the unimodal stiffnesses of its elements. Approximate models are constructed which are exact at preselected points along a line in the analysis space. An argument is also made for the use of multilinear polynomials as an alternative to Taylor expansion-based approximations.
A linear algebraic nonlinear superposition formula
NASA Astrophysics Data System (ADS)
Gordoa, Pilar R.; Conde, Juan M.
2002-04-01
The Darboux transformation provides an iterative approach to the generation of exact solutions for an integrable system. This process can be simplified using the Bäcklund transformation and Bianchi's theorem of permutability; in this way we construct a nonlinear superposition formula, that is, an equation relating a new solution to three previous solutions. In general this equation will be a differential equation; for some examples, such as the Korteweg-de Vries equation, it is a linear algebraic equation. This last is what happens also in the case of the system discussed in this Letter. The linear algebraic nonlinear superposition formula obtained here is a new result. As an example, we use it to construct the two soliton solution, as well as special cases of this last which give rise to solutions exhibiting combinations of fission and fusion. Solutions exhibiting repeated processes of fission and fusion are new phenomena within the area of soliton equations. We also consider obtaining solutions using a symmetry approach; in this way we obtain rational solutions and also the one soliton solution.
Simulating images captured by superposition lens cameras
NASA Astrophysics Data System (ADS)
Thangarajan, Ashok Samraj; Kakarala, Ramakrishna
2011-03-01
As the demand for reduction in the thickness of cameras rises, so too does the interest in thinner lens designs. One such radical approach toward developing a thin lens is obtained from nature's superposition principle as used in the eyes of many insects. But generally the images obtained from those lenses are fuzzy, and require reconstruction algorithms to complete the imaging process. A hurdle to developing such algorithms is that the existing literature does not provide realistic test images, aside from using commercial ray-tracing software which is costly. A solution for that problem is presented in this paper. Here a Gabor Super Lens (GSL), which is based on the superposition principle, is simulated using the public-domain ray-tracing software POV-Ray. The image obtained is of a grating surface as viewed through an actual GSL, which can be used to test reconstruction algorithms. The large computational time in rendering such images requires further optimization, and methods to do so are discussed.
ERIC Educational Resources Information Center
Budsankom, Prayoonsri; Sawangboon, Tatsirin; Damrongpanit, Suntorapot; Chuensirimongkol, Jariya
2015-01-01
The purpose of the research is to develop and identify the validity of factors affecting higher order thinking skills (HOTS) of students. The thinking skills can be divided into three types: analytical, critical, and creative thinking. This analysis is done by applying the meta-analytic structural equation modeling (MASEM) based on a database of…
Analytic structure of QCD propagators in Minkowski space
NASA Astrophysics Data System (ADS)
Siringo, Fabio
2016-12-01
Analytical functions for the propagators of QCD, including a set of chiral quarks, are derived by a one-loop massive expansion in the Landau gauge, deep in the infrared. By analytic continuation, the spectral functions are studied in Minkowski space, yielding a direct proof of positivity violation and confinement from first principles. The dynamical breaking of chiral symmetry is described on the same footing of gluon mass generation, providing a unified picture. While dealing with the exact Lagrangian, the expansion is based on massive free-particle propagators, is safe in the infrared and is equivalent to the standard perturbation theory in the UV. By dimensional regularization, all diverging mass terms cancel exactly without including mass counterterms that would spoil the gauge and chiral symmetry of the Lagrangian. Universal scaling properties are predicted for the inverse dressing functions and shown to be satisfied by the lattice data. Complex conjugated poles are found for the gluon propagator, in agreement with the i-particle scenario.
Superposition states for quantum nanoelectronic circuits and their nonclassical properties
NASA Astrophysics Data System (ADS)
Choi, Jeong Ryeol
2016-09-01
Quantum properties of a superposition state for a series RLC nanoelectronic circuit are investigated. Two displaced number states of the same amplitude but with opposite phases are considered as components of the superposition state. We have assumed that the capacitance of the system varies with time and a time-dependent power source is exerted on the system. The effects of displacement and a sinusoidal power source on the characteristics of the state are addressed in detail. Depending on the magnitude of the sinusoidal power source, the wave packets that propagate in charge(q)-space are more or less distorted. Provided that the displacement is sufficiently high, distinct interference structures appear in the plot of the time behavior of the probability density whenever the two components of the wave packet meet together. This is strong evidence for the advent of nonclassical properties in the system, that cannot be interpretable by the classical theory. Nonclassicality of a quantum system is not only a beneficial topic for academic interest in itself, but its results can be useful resources for quantum information and computation as well.
Analytical and Experimental Random Vibration of Nonlinear Aeroelastic Structures.
1987-01-28
shapes of structures acted the beam stiffness. The beam was modeled as a lumped-parame- upon by an external static loading. This type of problems ter...frequency’s mean and standard deviation. The where E! is the mean value of the beam stiffness and (x) is a influence of the static load on the statistics... dinamics . Sijthoff- Hilton, H H. and Feigen. M. Minimum weight analysis based on structural Noordhoff Co, Netherlands. reliability. J Aerospace Sc, 27
Authentication Protocol using Quantum Superposition States
Kanamori, Yoshito; Yoo, Seong-Moo; Gregory, Don A.; Sheldon, Frederick T
2009-01-01
When it became known that quantum computers could break the RSA (named for its creators - Rivest, Shamir, and Adleman) encryption algorithm within a polynomial-time, quantum cryptography began to be actively studied. Other classical cryptographic algorithms are only secure when malicious users do not have sufficient computational power to break security within a practical amount of time. Recently, many quantum authentication protocols sharing quantum entangled particles between communicators have been proposed, providing unconditional security. An issue caused by sharing quantum entangled particles is that it may not be simple to apply these protocols to authenticate a specific user in a group of many users. An authentication protocol using quantum superposition states instead of quantum entangled particles is proposed. The random number shared between a sender and a receiver can be used for classical encryption after the authentication has succeeded. The proposed protocol can be implemented with the current technologies we introduce in this paper.
ERIC Educational Resources Information Center
Cheung, Mike W.-L.; Cheung, Shu Fai
2016-01-01
Meta-analytic structural equation modeling (MASEM) combines the techniques of meta-analysis and structural equation modeling for the purpose of synthesizing correlation or covariance matrices and fitting structural equation models on the pooled correlation or covariance matrix. Both fixed-effects and random-effects models can be defined in MASEM.…
Dubrovsky, V. G.; Topovsky, A. V.
2013-03-15
New exact solutions, nonstationary and stationary, of Veselov-Novikov (VN) equation in the forms of simple nonlinear and linear superpositions of arbitrary number N of exact special solutions u{sup (n)}, n= 1, Horizontal-Ellipsis , N are constructed via Zakharov and Manakov {partial_derivative}-dressing method. Simple nonlinear superpositions are represented up to a constant by the sums of solutions u{sup (n)} and calculated by {partial_derivative}-dressing on nonzero energy level of the first auxiliary linear problem, i.e., 2D stationary Schroedinger equation. It is remarkable that in the zero energy limit simple nonlinear superpositions convert to linear ones in the form of the sums of special solutions u{sup (n)}. It is shown that the sums u=u{sup (k{sub 1})}+...+u{sup (k{sub m})}, 1 Less-Than-Or-Slanted-Equal-To k{sub 1} < k{sub 2} < Horizontal-Ellipsis < k{sub m} Less-Than-Or-Slanted-Equal-To N of arbitrary subsets of these solutions are also exact solutions of VN equation. The presented exact solutions include as superpositions of special line solitons and also superpositions of plane wave type singular periodic solutions. By construction these exact solutions represent also new exact transparent potentials of 2D stationary Schroedinger equation and can serve as model potentials for electrons in planar structures of modern electronics.
Superposition rendering: Increased realism for interactive walkthroughs
NASA Astrophysics Data System (ADS)
Bastos, Rui M. R. De
1999-11-01
The light transport equation, conventionally known as the rendering equation in a slightly different form, is an implicit integral equation, which represents the interactions of light with matter and the distribution of light in a scene. This research describes a signals-and- systems approach to light transport and casts the light transport equation in terms of convolution. Additionally, the light transport problem is linearly decomposed into simpler problems with simpler solutions, which are then recombined to approximate the full solution. The central goal is to provide interactive photorealistic rendering of virtual environments. We show how the light transport problem can be cast in terms of signals-and-systems. The light is the signal and the materials are the systems. The outgoing light from a light transfer at a surface point is given by convolving the incoming light with the material's impulse response (the material's BRDF/BTDF). Even though the theoretical approach is presented in directional-space, we present an approximation in screen-space, which enables the exploitation of graphics hardware convolution for approximating the light transport equation. The convolution approach to light transport is not enough to fully solve the light transport problem at interactive rates with current machines. We decompose the light transport problem into simpler problems. The decomposition of the light transport problem is based on distinct characteristics of different parts of the problem: the ideally diffuse, the ideally specular, and the glossy transfers. A technique for interactive rendering of each of these components is presented as well a technique for superposing the independent components in a multipass manner in real time. Given the extensive use of the superposition principle in this research, we name our approach superposition rendering to distinguish it from other standard hardware-aided multipass rendering approaches.
Analytical review of structure and regulation of hemopoiesis
Cronkite, E.P.
1987-01-01
The development of knowledge on the structure of hemopoiesis and its regulation can be divided into four broad areas: descriptive morphology, kinetics of cell proliferation, regulation of rates of cell proliferation through interaction of molecular regulators and their cell surface receptors, and clinical applications. 60 refs., 6 figs.
Design Protocols and Analytical Strategies that Incorporate Structural Reliability Models
NASA Technical Reports Server (NTRS)
Duffy, Stephen F.
1997-01-01
Ceramic matrix composites (CMC) and intermetallic materials (e.g., single crystal nickel aluminide) are high performance materials that exhibit attractive mechanical, thermal and chemical properties. These materials are critically important in advancing certain performance aspects of gas turbine engines. From an aerospace engineer's perspective the new generation of ceramic composites and intermetallics offers a significant potential for raising the thrust/weight ratio and reducing NO(x) emissions of gas turbine engines. These aspects have increased interest in utilizing these materials in the hot sections of turbine engines. However, as these materials evolve and their performance characteristics improve a persistent need exists for state-of-the-art analytical methods that predict the response of components fabricated from CMC and intermetallic material systems. This need provided the motivation for the technology developed under this research effort. Continuous ceramic fiber composites exhibit an increase in work of fracture, which allows for "graceful" rather than catastrophic failure. When loaded in the fiber direction, these composites retain substantial strength capacity beyond the initiation of transverse matrix cracking despite the fact that neither of its constituents would exhibit such behavior if tested alone. As additional load is applied beyond first matrix cracking, the matrix tends to break in a series of cracks bridged by the ceramic fibers. Any additional load is born increasingly by the fibers until the ultimate strength of the composite is reached. Thus modeling efforts supported under this research effort have focused on predicting this sort of behavior. For single crystal intermetallics the issues that motivated the technology development involved questions relating to material behavior and component design. Thus the research effort supported by this grant had to determine the statistical nature and source of fracture in a high strength, Ni
Design Protocols and Analytical Strategies that Incorporate Structural Reliability Models
NASA Technical Reports Server (NTRS)
Duffy, Stephen F.
1997-01-01
Ceramic matrix composites (CMC) and intermetallic materials (e.g., single crystal nickel aluminide) are high performance materials that exhibit attractive mechanical, thermal, and chemical properties. These materials are critically important in advancing certain performance aspects of gas turbine engines. From an aerospace engineers perspective the new generation of ceramic composites and intermetallics offers a significant potential for raising the thrust/weight ratio and reducing NO(sub x) emissions of gas turbine engines. These aspects have increased interest in utilizing these materials in the hot sections of turbine engines. However, as these materials evolve and their performance characteristics improve a persistent need exists for state-of-the-art analytical methods that predict the response of components fabricated from CMC and intermetallic material systems. This need provided the motivation for the technology developed under this research effort. Continuous ceramic fiber composites exhibit an increase in work of fracture, which allows for 'graceful' rather than catastrophic failure. When loaded in the fiber direction these composites retain substantial strength capacity beyond the initiation of transverse matrix cracking despite the fact that neither of its constituents would exhibit such behavior if tested alone. As additional load is applied beyond first matrix cracking, the matrix tends to break in a series of cracks bridged by the ceramic fibers. Any additional load is born increasingly by the fibers until the ultimate strength of the composite is reached. Thus modeling efforts supported under this research effort have focused on predicting this sort of behavior. For single crystal intermetallics the issues that motivated the technology development involved questions relating to material behavior and component design. Thus the research effort supported by this grant had to determine the statistical nature and source of fracture in a high strength, Ni
Versatile Measurement Techniques to Validate Analytical Structural Mechanical Models
2007-03-01
ATM of IEST, Banaszak and Parin , Phoenix, AZ, 8 May 2006 presentation. 9. "Exploring Fiber Optic Strain Sensors for Testing Future Aerospace...Vehicles Directorate-Structures Division Wright Patterson AFB, OH David.Banaszak@wpafb.af.mil Damping Technology, Inc. - Mishawaka, IN Michael L. Parin ...27 Patch Installation Procedures Installed by Mike Parin during October 2003 President - Damping Technology, Inc. Applied 5 Pieces Total 12” x 3” One
De Martini, Francesco; Sciarrino, Fabio; Spagnolo, Nicolò
2009-09-04
We show that all macroscopic quantum superpositions (MQS) based on phase-covariant quantum cloning are characterized by an anomalous high resilence to the decoherence processes. The analysis supports the results of recent MQS experiments and leads to conceive a useful conjecture regarding the realization of complex decoherence-free structures for quantum information, such as the quantum computer.
NASA Astrophysics Data System (ADS)
de Martini, Francesco; Sciarrino, Fabio; Spagnolo, Nicolò
2009-09-01
We show that all macroscopic quantum superpositions (MQS) based on phase-covariant quantum cloning are characterized by an anomalous high resilence to the decoherence processes. The analysis supports the results of recent MQS experiments and leads to conceive a useful conjecture regarding the realization of complex decoherence-free structures for quantum information, such as the quantum computer.
On sufficient statistics of least-squares superposition of vector sets.
Konagurthu, Arun S; Kasarapu, Parthan; Allison, Lloyd; Collier, James H; Lesk, Arthur M
2015-06-01
The problem of superposition of two corresponding vector sets by minimizing their sum-of-squares error under orthogonal transformation is a fundamental task in many areas of science, notably structural molecular biology. This problem can be solved exactly using an algorithm whose time complexity grows linearly with the number of correspondences. This efficient solution has facilitated the widespread use of the superposition task, particularly in studies involving macromolecular structures. This article formally derives a set of sufficient statistics for the least-squares superposition problem. These statistics are additive. This permits a highly efficient (constant time) computation of superpositions (and sufficient statistics) of vector sets that are composed from its constituent vector sets under addition or deletion operation, where the sufficient statistics of the constituent sets are already known (that is, the constituent vector sets have been previously superposed). This results in a drastic improvement in the run time of the methods that commonly superpose vector sets under addition or deletion operations, where previously these operations were carried out ab initio (ignoring the sufficient statistics). We experimentally demonstrate the improvement our work offers in the context of protein structural alignment programs that assemble a reliable structural alignment from well-fitting (substructural) fragment pairs. A C++ library for this task is available online under an open-source license.
An Analytical Solution for Transient Thermal Response of an Insulated Structure
NASA Technical Reports Server (NTRS)
Blosser, Max L.
2012-01-01
An analytical solution was derived for the transient response of an insulated aerospace vehicle structure subjected to a simplified heat pulse. This simplified problem approximates the thermal response of a thermal protection system of an atmospheric entry vehicle. The exact analytical solution is solely a function of two non-dimensional parameters. A simpler function of these two parameters was developed to approximate the maximum structural temperature over a wide range of parameter values. Techniques were developed to choose constant, effective properties to represent the relevant temperature and pressure-dependent properties for the insulator and structure. A technique was also developed to map a time-varying surface temperature history to an equivalent square heat pulse. Using these techniques, the maximum structural temperature rise was calculated using the analytical solutions and shown to typically agree with finite element simulations within 10 to 20 percent over the relevant range of parameters studied.
Multichannel Polarization-Controllable Superpositions of Orbital Angular Momentum States.
Yue, Fuyong; Wen, Dandan; Zhang, Chunmei; Gerardot, Brian D; Wang, Wei; Zhang, Shuang; Chen, Xianzhong
2017-04-01
A facile metasurface approach is shown to realize polarization-controllable multichannel superpositions of orbital angular momentum (OAM) states with various topological charges. By manipulating the polarization state of the incident light, four kinds of superpositions of OAM states are realized using a single metasurface consisting of space-variant arrays of gold nanoantennas.
On the analytical modeling of the nonlinear vibrations of pretensioned space structures
NASA Technical Reports Server (NTRS)
Housner, J. M.; Belvin, W. K.
1983-01-01
Pretensioned structures are receiving considerable attention as candidate large space structures. A typical example is a hoop-column antenna. The large number of preloaded members requires efficient analytical methods for concept validation and design. Validation through analyses is especially important since ground testing may be limited due to gravity effects and structural size. The present investigation has the objective to present an examination of the analytical modeling of pretensioned members undergoing nonlinear vibrations. Two approximate nonlinear analysis are developed to model general structural arrangements which include beam-columns and pretensioned cables attached to a common nucleus, such as may occur at a joint of a pretensioned structure. Attention is given to structures undergoing nonlinear steady-state oscillations due to sinusoidal excitation forces. Three analyses, linear, quasi-linear, and nonlinear are conducted and applied to study the response of a relatively simple cable stiffened structure.
Analytic and Simulation Studies of Dust Grain Interaction and Structuring
NASA Astrophysics Data System (ADS)
Lampe, Martin; Joyce, Glenn; Ganguli, Gurudas
For dust grains in stationary plasma, a quantitative assessment is made of the effect of centrifugal potential barriers on ion trajectories near a grain. It is shown that in most situations of interest the barriers are weak and only marginally affect the validity of the orbital-motion-limited (OML) theory. The OML theory is then used to show that the electrostatic interaction between grains is always repulsive. The ion-shadowing force is calculated, and it is shown that this force can lead to a weak net attraction between grains at long range, under certain conditions with large grains, dense plasma, and/or low gas pressure. For grains in streaming plasma at or near the sheath, it is shown that nonlinear effects are weak and the grains can be represented as dressed particles interacting via the dynamically shielded Coulomb interaction, which includes wakefields, Landau damping, and collisional damping. The Dynamically Shielded Dust (DSD) simulation code, which is based on this model, is described and a simulation is shown for strongly coupled grains in flowing plasma. The simulation shows ordering of the grains into rigid strings aligned with the ion flow, and looser glass-like organization of the strings in the transverse plane. The presence of strings with odd and even numbers of grains results in stratification of the grains into planes with an alternating structure.
Design Protocols and Analytical Strategies that Incorporate Structural Reliability Models
NASA Technical Reports Server (NTRS)
Duffy, Stephen F.
1995-01-01
The general goal of this project is to establish design protocols that enable the engineer to analyze and predict certain types of behavior in ceramic composites. Sections of the final report addresses the following: Description of the Problem that Motivated the Technology Development, Description of the New Technology that was Developed, Unique and Novel Features of the Technology and Results/Benefits of Application (year by year accomplishments), and Utilization of New Technology in Non-Aerospace Applications. Activities for this reporting period included the development of a design analysis as part of a cooperative agreement with general Electric Aircraft Engines. The effort focused on modifying the Toughened Ceramics Analysis and Reliability Evaluation of Structures (TCARES) algorithm for use in the design of engine components fabricated from NiAl. Other activities related to the development of an ASTM standard practice for estimating Weibull parameters. The standard focuses on the evaluation and reporting of uniaxial strength data, and the estimation of probability distribution parameters for ceramics which fail in a brittle fashion.
Superposition properties of interacting ion channels.
Keleshian, A M; Yeo, G F; Edeson, R O; Madsen, B W
1994-01-01
Quantitative analysis of patch clamp data is widely based on stochastic models of single-channel kinetics. Membrane patches often contain more than one active channel of a given type, and it is usually assumed that these behave independently in order to interpret the record and infer individual channel properties. However, recent studies suggest there are significant channel interactions in some systems. We examine a model of dependence in a system of two identical channels, each modeled by a continuous-time Markov chain in which specified transition rates are dependent on the conductance state of the other channel, changing instantaneously when the other channel opens or closes. Each channel then has, e.g., a closed time density that is conditional on the other channel being open or closed, these being identical under independence. We relate the two densities by a convolution function that embodies information about, and serves to quantify, dependence in the closed class. Distributions of observable (superposition) sojourn times are given in terms of these conditional densities. The behavior of two channel systems based on two- and three-state Markov models is examined by simulation. Optimized fitting of simulated data using reasonable parameters values and sample size indicates that both positive and negative cooperativity can be distinguished from independence. PMID:7524711
Macroscopic superpositions and gravimetry with quantum magnetomechanics
NASA Astrophysics Data System (ADS)
Johnsson, Mattias T.; Brennen, Gavin K.; Twamley, Jason
2016-11-01
Precision measurements of gravity can provide tests of fundamental physics and are of broad practical interest for metrology. We propose a scheme for absolute gravimetry using a quantum magnetomechanical system consisting of a magnetically trapped superconducting resonator whose motion is controlled and measured by a nearby RF-SQUID or flux qubit. By driving the mechanical massive resonator to be in a macroscopic superposition of two different heights our we predict that our interferometry protocol could, subject to systematic errors, achieve a gravimetric sensitivity of Δg/g ~ 2.2 × 10‑10 Hz‑1/2, with a spatial resolution of a few nanometres. This sensitivity and spatial resolution exceeds the precision of current state of the art atom-interferometric and corner-cube gravimeters by more than an order of magnitude, and unlike classical superconducting interferometers produces an absolute rather than relative measurement of gravity. In addition, our scheme takes measurements at ~10 kHz, a region where the ambient vibrational noise spectrum is heavily suppressed compared the ~10 Hz region relevant for current cold atom gravimeters.
Macroscopic superpositions and gravimetry with quantum magnetomechanics
Johnsson, Mattias T.; Brennen, Gavin K.; Twamley, Jason
2016-01-01
Precision measurements of gravity can provide tests of fundamental physics and are of broad practical interest for metrology. We propose a scheme for absolute gravimetry using a quantum magnetomechanical system consisting of a magnetically trapped superconducting resonator whose motion is controlled and measured by a nearby RF-SQUID or flux qubit. By driving the mechanical massive resonator to be in a macroscopic superposition of two different heights our we predict that our interferometry protocol could, subject to systematic errors, achieve a gravimetric sensitivity of Δg/g ~ 2.2 × 10−10 Hz−1/2, with a spatial resolution of a few nanometres. This sensitivity and spatial resolution exceeds the precision of current state of the art atom-interferometric and corner-cube gravimeters by more than an order of magnitude, and unlike classical superconducting interferometers produces an absolute rather than relative measurement of gravity. In addition, our scheme takes measurements at ~10 kHz, a region where the ambient vibrational noise spectrum is heavily suppressed compared the ~10 Hz region relevant for current cold atom gravimeters. PMID:27869142
Controlling coherent state superpositions with superconducting circuits
NASA Astrophysics Data System (ADS)
Vlastakis, Brian Michael
Quantum computation requires a large yet controllable Hilbert space. While many implementations use discrete quantum variables such as the energy states of a two-level system to encode quantum information, continuous variables could allow access to a larger computational space while minimizing the amount of re- quired hardware. With a toolset of conditional qubit-photon logic, we encode quantum information into the amplitude and phase of coherent state superpositions in a resonator, also known as Schrddinger cat states. We achieve this using a superconducting transmon qubit with a strong off-resonant coupling to a waveguide cavity. This dispersive interaction is much greater than decoherence rates and higher-order nonlinearites and therefore allows for simultaneous control of over one hundred photons. Furthermore, we combine this experiment with fast, high-fidelity qubit state readout to perform composite qubit-cavity state tomography and detect entanglement between a physical qubit and a cat-state encoded qubit. These results have promising applications for redundant encoding in a cavity state and ultimately quantum error correction with superconducting circuits.
Advanced superposition methods for high speed turbopump vibration analysis
NASA Technical Reports Server (NTRS)
Nielson, C. E.; Campany, A. D.
1981-01-01
The small, high pressure Mark 48 liquid hydrogen turbopump was analyzed and dynamically tested to determine the cause of high speed vibration at an operating speed of 92,400 rpm. This approaches the design point operating speed of 95,000 rpm. The initial dynamic analysis in the design stage and subsequent further analysis of the rotor only dynamics failed to predict the vibration characteristics found during testing. An advanced procedure for dynamics analysis was used in this investigation. The procedure involves developing accurate dynamic models of the rotor assembly and casing assembly by finite element analysis. The dynamically instrumented assemblies are independently rap tested to verify the analytical models. The verified models are then combined by modal superposition techniques to develop a completed turbopump model where dynamic characteristics are determined. The results of the dynamic testing and analysis obtained are presented and methods of moving the high speed vibration characteristics to speeds above the operating range are recommended. Recommendations for use of these advanced dynamic analysis procedures during initial design phases are given.
Zhou, Haibo; Ying, Hao
2016-06-01
A conventional controller's explicit input-output mathematical relationship, also known as its analytical structure, is always available for analysis and design of a control system. In contrast, virtually all type-2 (T2) fuzzy controllers are treated as black-box controllers in the literature in that their analytical structures are unknown, which inhibits precise and comprehensive understanding and analysis. In this regard, a long-standing fundamental issue remains unresolved: how a T2 fuzzy set's footprint of uncertainty, a key element differentiating a T2 controller from a type-1 (T1) controller, affects a controller's analytical structure. In this paper, we describe an innovative technique for deriving analytical structures of a class of typical interval T2 (IT2) TS fuzzy controllers. This technique makes it possible to analyze the analytical structures of the controllers to reveal the role of footprints of uncertainty in shaping the structures. Specifically, we have mathematically proven that under certain conditions, the larger the footprints, the more the IT2 controllers resemble linear or piecewise linear controllers. When the footprints are at their maximum, the IT2 controllers actually become linear or piecewise linear controllers. That is to say the smaller the footprints, the more nonlinear the controllers. The most nonlinear IT2 controllers are attained at zero footprints, at which point they become T1 controllers. This finding implies that sometimes if strong nonlinearity is most important and desired, one should consider using a smaller footprint or even just a T1 fuzzy controller. This paper exemplifies the importance and value of the analytical structure approach for comprehensive analysis of T2 fuzzy controllers.
Analytical modeling of structure-soil systems for lunar bases
NASA Technical Reports Server (NTRS)
Macari-Pasqualino, Jose Emir
1989-01-01
The study of the behavior of granular materials in a reduced gravity environment and under low effective stresses became a subject of great interest in the mid 1960's when NASA's Surveyor missions to the Moon began the first extraterrestrial investigation and it was found that Lunar soils exhibited properties quite unlike those on Earth. This subject gained interest during the years of the Apollo missions and more recently due to NASA's plans for future exploration and colonization of Moon and Mars. It has since been clear that a good understanding of the mechanical properties of granular materials under reduced gravity and at low effective stress levels is of paramount importance for the design and construction of surface and buried structures on these bodies. In order to achieve such an understanding it is desirable to develop a set of constitutive equations that describes the response of such materials as they are subjected to tractions and displacements. This presentation examines issues associated with conducting experiments on highly nonlinear granular materials under high and low effective stresses. The friction and dilatancy properties which affect the behavior of granular soils with low cohesion values are assessed. In order to simulate the highly nonlinear strength and stress-strain behavior of soils at low as well as high effective stresses, a versatile isotropic, pressure sensitive, third stress invariant dependent, cone-cap elasto-plastic constitutive model was proposed. The integration of the constitutive relations is performed via a fully implicit Backward Euler technique known as the Closest Point Projection Method. The model was implemented into a finite element code in order to study nonlinear boundary value problems associated with homogeneous as well as nonhomogeneous deformations at low as well as high effective stresses. The effect of gravity (self-weight) on the stress-strain-strength response of these materials is evaluated. The calibration
Optical information encryption based on incoherent superposition with the help of the QR code
NASA Astrophysics Data System (ADS)
Qin, Yi; Gong, Qiong
2014-01-01
In this paper, a novel optical information encryption approach is proposed with the help of QR code. This method is based on the concept of incoherent superposition which we introduce for the first time. The information to be encrypted is first transformed into the corresponding QR code, and thereafter the QR code is further encrypted into two phase only masks analytically by use of the intensity superposition of two diffraction wave fields. The proposed method has several advantages over the previous interference-based method, such as a higher security level, a better robustness against noise attack, a more relaxed work condition, and so on. Numerical simulation results and actual smartphone collected results are shown to validate our proposal.
NASA Astrophysics Data System (ADS)
Manea, I.; Popa, G.; Girnita, I.; Prenta, G.
2015-11-01
The paper presents a practical methodology for design and structural verification of the locomotive bogie frames using a modern software package for design, structural verification and validation through combined, analytical and experimental methods. In the initial stage, the bogie geometry is imported from a CAD program into a finite element analysis program, such as Ansys. The analytical model validation is done by experimental modal analysis carried out on a finished bogie frame. The bogie frame own frequencies and own modes by both experimental and analytic methods are determined and the correlation analysis of the two types of models is performed. If the results are unsatisfactory, the structural optimization should be performed. If the results are satisfactory, the qualification procedures follow by static and fatigue tests carried out in a laboratory with international accreditation in the field. This paper presents an application made on bogie frames for the LEMA electric locomotive of 6000 kW.
Gillen, David S.
2014-08-07
Analysis activities for Nonproliferation and Arms Control verification require the use of many types of data. Tabular structured data, such as Excel spreadsheets and relational databases, have traditionally been used for data mining activities, where specific queries are issued against data to look for matching results. The application of visual analytics tools to structured data enables further exploration of datasets to promote discovery of previously unknown results. This paper discusses the application of a specific visual analytics tool to datasets related to the field of Arms Control and Nonproliferation to promote the use of visual analytics more broadly in this domain. Visual analytics focuses on analytical reasoning facilitated by interactive visual interfaces (Wong and Thomas 2004). It promotes exploratory analysis of data, and complements data mining technologies where known patterns can be mined for. Also with a human in the loop, they can bring in domain knowledge and subject matter expertise. Visual analytics has not widely been applied to this domain. In this paper, we will focus on one type of data: structured data, and show the results of applying a specific visual analytics tool to answer questions in the Arms Control and Nonproliferation domain. We chose to use the T.Rex tool, a visual analytics tool developed at PNNL, which uses a variety of visual exploration patterns to discover relationships in structured datasets, including a facet view, graph view, matrix view, and timeline view. The facet view enables discovery of relationships between categorical information, such as countries and locations. The graph tool visualizes node-link relationship patterns, such as the flow of materials being shipped between parties. The matrix visualization shows highly correlated categories of information. The timeline view shows temporal patterns in data. In this paper, we will use T.Rex with two different datasets to demonstrate how interactive exploration of
Reliability-based structural optimization: A proposed analytical-experimental study
NASA Technical Reports Server (NTRS)
Stroud, W. Jefferson; Nikolaidis, Efstratios
1993-01-01
An analytical and experimental study for assessing the potential of reliability-based structural optimization is proposed and described. In the study, competing designs obtained by deterministic and reliability-based optimization are compared. The experimental portion of the study is practical because the structure selected is a modular, actively and passively controlled truss that consists of many identical members, and because the competing designs are compared in terms of their dynamic performance and are not destroyed if failure occurs. The analytical portion of this study is illustrated on a 10-bar truss example. In the illustrative example, it is shown that reliability-based optimization can yield a design that is superior to an alternative design obtained by deterministic optimization. These analytical results provide motivation for the proposed study, which is underway.
Reliability and structural integrity. [analytical model for calculating crack detection probability
NASA Technical Reports Server (NTRS)
Davidson, J. R.
1973-01-01
An analytic model is developed to calculate the reliability of a structure after it is inspected for cracks. The model accounts for the growth of undiscovered cracks between inspections and their effect upon the reliability after subsequent inspections. The model is based upon a differential form of Bayes' Theorem for reliability, and upon fracture mechanics for crack growth.
ERIC Educational Resources Information Center
Cheung, Mike W. L.; Chan, Wai
2009-01-01
Structural equation modeling (SEM) is widely used as a statistical framework to test complex models in behavioral and social sciences. When the number of publications increases, there is a need to systematically synthesize them. Methodology of synthesizing findings in the context of SEM is known as meta-analytic SEM (MASEM). Although correlation…
ERIC Educational Resources Information Center
McGill, Ryan J.; Canivez, Gary L.
2016-01-01
As recommended by Carroll, the present study examined the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition Spanish (WISC-IV Spanish) normative sample using higher order exploratory factor analytic techniques not included in the WISC-IV Spanish Technical Manual. Results indicated that the WISC-IV Spanish subtests were…
ERIC Educational Resources Information Center
Szafran, Zvi
1985-01-01
Background information, procedures used, and typical results obtained are provided for an experiment that examines the ability of nuclear magnetic resonance (NMR) to distinguish between structural isomers via resonance multiplicities and chemical shifts. Reasons for incorporating the experiment into organic, analytical, or physical chemistry…
NASA Technical Reports Server (NTRS)
Haley, P. J.
1982-01-01
The forcing functions and structural responses characterizing gas turbine rotor/case system vibration due to rotating stall in an axial flow compressor are described. Two data sets with fundamentally different response characteristics are presented; one is supersynchronous and the other subsynchronous. Conventional beam element rotor dynamics analysis is shown to be severely limited in its ability to predict these responses. A new analytical approach, which significantly increases structural response predictive capability for these phenomena, is briefly discussed.
Nonclassical properties and quantum resources of hierarchical photonic superposition states
Volkoff, T. J.
2015-11-15
We motivate and introduce a class of “hierarchical” quantum superposition states of N coupled quantum oscillators. Unlike other well-known multimode photonic Schrödinger-cat states such as entangled coherent states, the hierarchical superposition states are characterized as two-branch superpositions of tensor products of single-mode Schrödinger-cat states. In addition to analyzing the photon statistics and quasiprobability distributions of prominent examples of these nonclassical states, we consider their usefulness for highprecision quantum metrology of nonlinear optical Hamiltonians and quantify their mode entanglement. We propose two methods for generating hierarchical superpositions in N = 2 coupled microwave cavities, exploiting currently existing quantum optical technology for generating entanglement between spatially separated electromagnetic field modes.
Analytic Modeling of the Hydrodynamic, Thermal, and Structural Behavior of Foil Thrust Bearings
NASA Technical Reports Server (NTRS)
Bruckner, Robert J.; DellaCorte, Christopher; Prahl, Joseph M.
2005-01-01
A simulation and modeling effort is conducted on gas foil thrust bearings. A foil bearing is a self acting hydrodynamic device capable of separating stationary and rotating components of rotating machinery by a film of air or other gaseous lubricant. Although simple in appearance these bearings have proven to be complicated devices in analysis. They are sensitive to fluid structure interaction, use a compressible gas as a lubricant, may not be in the fully continuum range of fluid mechanics, and operate in the range where viscous heat generation is significant. These factors provide a challenge to the simulation and modeling task. The Reynolds equation with the addition of Knudsen number effects due to thin film thicknesses is used to simulate the hydrodynamics. The energy equation is manipulated to simulate the temperature field of the lubricant film and combined with the ideal gas relationship, provides density field input to the Reynolds equation. Heat transfer between the lubricant and the surroundings is also modeled. The structural deformations of the bearing are modeled with a single partial differential equation. The equation models the top foil as a thin, bending dominated membrane whose deflections are governed by the biharmonic equation. A linear superposition of hydrodynamic load and compliant foundation reaction is included. The stiffness of the compliant foundation is modeled as a distributed stiffness that supports the top foil. The system of governing equations is solved numerically by a computer program written in the Mathematica computing environment. Representative calculations and comparisons with experimental results are included for a generation I gas foil thrust bearing.
Quantum State Engineering Via Coherent-State Superpositions
NASA Technical Reports Server (NTRS)
Janszky, Jozsef; Adam, P.; Szabo, S.; Domokos, P.
1996-01-01
The quantum interference between the two parts of the optical Schrodinger-cat state makes possible to construct a wide class of quantum states via discrete superpositions of coherent states. Even a small number of coherent states can approximate the given quantum states at a high accuracy when the distance between the coherent states is optimized, e. g. nearly perfect Fock state can be constructed by discrete superpositions of n + 1 coherent states lying in the vicinity of the vacuum state.
NASA Technical Reports Server (NTRS)
Montgomery, Raymond C.
1988-01-01
This paper deals with analytic redundancy management of systems that have appreciable structural dynamics and require active control. The class of systems considered is large, lightweight spacecraft that have large numbers of distributed sensors and actuators. Both preliminary design and on-line operations are studied. For the preliminary design we deal with the placement of the sensor and actuator components on a highly flexible spacecraft. For on-line operation an analytic redundancy management system based on examination of the residuals of a Kalman filter is considered. A large, flexible grid made of overlapping aluminum bars is used to experimentally evaluate this analytic redundancy management system. Results of the experimental evaluation are included in the paper.
Magnetic anomaly depth and structural index estimation using different height analytic signals data
NASA Astrophysics Data System (ADS)
Zhou, Shuai; Huang, Danian; Su, Chao
2016-09-01
This paper proposes a new semi-automatic inversion method for magnetic anomaly data interpretation that uses the combination of analytic signals of the anomaly at different heights to determine the depth and the structural index N of the sources. The new method utilizes analytic signals of the original anomaly at different height to effectively suppress the noise contained in the anomaly. Compared with the other high-order derivative calculation methods based on analytic signals, our method only computes first-order derivatives of the anomaly, which can be used to obtain more stable and accurate results. Tests on synthetic noise-free and noise-corrupted magnetic data indicate that the new method can estimate the depth and N efficiently. The technique is applied to a real measured magnetic anomaly in Southern Illinois caused by a known dike, and the result is in agreement with the drilling information and inversion results within acceptable calculation error.
Flight and analytical investigations of a structural mode excitation system on the YF-12A airplane
NASA Technical Reports Server (NTRS)
Goforth, E. A.; Murphy, R. C.; Beranek, J. A.; Davis, R. A.
1987-01-01
A structural excitation system, using an oscillating canard vane to generate force, was mounted on the forebody of the YF-12A airplane. The canard vane was used to excite the airframe structural modes during flight in the subsonic, transonic, and supersonic regimes. Structural modal responses generated by the canard vane forces were measured at the flight test conditions by airframe-mounted accelerometers. Correlations of analytical and experimental aeroelastic results were made. Doublet lattice, steady state double lattice with uniform lag, Mach box, and piston theory all produced acceptable analytical aerodynamic results within the restrictions that apply to each. In general, the aerodynamic theory methods, carefully applied, were found to predict the dynamic behavior of the YF-12A aircraft adequately.
Analytic structure of the multichannel Jost matrix for potentials with Coulombic tails
Rakityansky, S. A.; Elander, N.
2013-12-15
A quantum system is considered that can move in N two-body channels with the potentials that may include the Coulomb interaction. For this system, the Jost matrix is constructed in such a way that all its dependencies on the channel momenta and Sommerfeld parameters are factorized in the form of explicit analytic expressions. It is shown that the two remaining unknown matrices are single-valued analytic functions of the energy and therefore can be expanded in the Taylor series near an arbitrary point within the domain of their analyticity. It is derived a system of first-order differential equations whose solutions determine the expansion coefficients of these series. Alternatively, the unknown expansion coefficients can be used as fitting parameters for parametrizing experimental data similarly to the effective-range expansion. Such a parametrization has the advantage of preserving proper analytic structure of the Jost matrix and can be done not only near the threshold energies, but around any collision or even complex energy. As soon as the parameters are obtained, the Jost matrix (and therefore the S-matrix) is known analytically on all sheets of the Riemann surface, and thus enables one to locate possible resonances.
Quantum superposition at the half-metre scale.
Kovachy, T; Asenbaum, P; Overstreet, C; Donnelly, C A; Dickerson, S M; Sugarbaker, A; Hogan, J M; Kasevich, M A
2015-12-24
The quantum superposition principle allows massive particles to be delocalized over distant positions. Though quantum mechanics has proved adept at describing the microscopic world, quantum superposition runs counter to intuitive conceptions of reality and locality when extended to the macroscopic scale, as exemplified by the thought experiment of Schrödinger's cat. Matter-wave interferometers, which split and recombine wave packets in order to observe interference, provide a way to probe the superposition principle on macroscopic scales and explore the transition to classical physics. In such experiments, large wave-packet separation is impeded by the need for long interaction times and large momentum beam splitters, which cause susceptibility to dephasing and decoherence. Here we use light-pulse atom interferometry to realize quantum interference with wave packets separated by up to 54 centimetres on a timescale of 1 second. These results push quantum superposition into a new macroscopic regime, demonstrating that quantum superposition remains possible at the distances and timescales of everyday life. The sub-nanokelvin temperatures of the atoms and a compensation of transverse optical forces enable a large separation while maintaining an interference contrast of 28 per cent. In addition to testing the superposition principle in a new regime, large quantum superposition states are vital to exploring gravity with atom interferometers in greater detail. We anticipate that these states could be used to increase sensitivity in tests of the equivalence principle, measure the gravitational Aharonov-Bohm effect, and eventually detect gravitational waves and phase shifts associated with general relativity.
Perelberg, Rosine Jozef
2016-12-01
This paper explores the meaning of a patient's hallucinatory experiences in the course of a five times a week analysis. I will locate my understanding within the context of André Green's ideas on the role of the framing structure and the negative hallucination in the structuring of the mind. The understanding of the transference and countertransference was crucial in the creation of meaning and enabling the transformations that took place in the analytic process. Through a detailed analysis of a clinical example the author examines Bion's distinction between hysterical hallucinations and psychotic hallucinations and formulates her own hypothesis about the distinctions between the two. The paper suggests that whilst psychotic hallucinations express a conflict between life and death, in the hysterical hallucination it is between love and hate. The paper also contains some reflections on the dramatic nature of the analytic encounter.
Big data and high-performance analytics in structural health monitoring for bridge management
NASA Astrophysics Data System (ADS)
Alampalli, Sharada; Alampalli, Sandeep; Ettouney, Mohammed
2016-04-01
Structural Health Monitoring (SHM) can be a vital tool for effective bridge management. Combining large data sets from multiple sources to create a data-driven decision-making framework is crucial for the success of SHM. This paper presents a big data analytics framework that combines multiple data sets correlated with functional relatedness to convert data into actionable information that empowers risk-based decision-making. The integrated data environment incorporates near real-time streams of semi-structured data from remote sensors, historical visual inspection data, and observations from structural analysis models to monitor, assess, and manage risks associated with the aging bridge inventories. Accelerated processing of dataset is made possible by four technologies: cloud computing, relational database processing, support from NOSQL database, and in-memory analytics. The framework is being validated on a railroad corridor that can be subjected to multiple hazards. The framework enables to compute reliability indices for critical bridge components and individual bridge spans. In addition, framework includes a risk-based decision-making process that enumerate costs and consequences of poor bridge performance at span- and network-levels when rail networks are exposed to natural hazard events such as floods and earthquakes. Big data and high-performance analytics enable insights to assist bridge owners to address problems faster.
Fixed- and random-effects meta-analytic structural equation modeling: examples and analyses in R.
Cheung, Mike W-L
2014-03-01
Meta-analytic structural equation modeling (MASEM) combines the ideas of meta-analysis and structural equation modeling for the purpose of synthesizing correlation or covariance matrices and fitting structural equation models on the pooled correlation or covariance matrix. Cheung and Chan (Psychological Methods 10:40-64, 2005b, Structural Equation Modeling 16:28-53, 2009) proposed a two-stage structural equation modeling (TSSEM) approach to conducting MASEM that was based on a fixed-effects model by assuming that all studies have the same population correlation or covariance matrices. The main objective of this article is to extend the TSSEM approach to a random-effects model by the inclusion of study-specific random effects. Another objective is to demonstrate the procedures with two examples using the metaSEM package implemented in the R statistical environment. Issues related to and future directions for MASEM are discussed.
Analytic Sensitivities for Shape Optimization in Equivalent Plate Structural Wing Models
NASA Technical Reports Server (NTRS)
Livne, Eli
1994-01-01
Equivalent plate modeling techniques based on Ritz analysis with simple polynomials prove to be efficient tools for structural modeling of wings in the preliminary design stage. Accuracy problems are encountered, however, when these models are used to obtain finite difference behavior sensitivities with respect to planform shape. The accuracy problems are associated with the poor numerical conditioning of static and eigenvalue equations. As higher-order polynomials are being used to Improve the analysis itself, the more sensitive is the finite difference derivative to the step size used. This article describes a formulation of wing equivalent plate modeling in which it is simple to obtain analytic, explicit expressions for stiffness and mass matrix elements without the need to perform numerical integration. This formulation leads naturally to analytic expressions for the derivatives of displacements, stresses, and natural frequencies with respect to shape design variables. This article examines the accuracy of finite difference derivatives compared with the analytic derivatives, and shows that In some cases it is impossible to obtain any information of value by finite differences. Analytic sensitivities, in this case, are still sufficiently accurate for design optimization.
Hybrid experimental/analytical models of structural dynamics - Creation and use for predictions
NASA Technical Reports Server (NTRS)
Balmes, Etienne
1993-01-01
An original complete methodology for the construction of predictive models of damped structural vibrations is introduced. A consistent definition of normal and complex modes is given which leads to an original method to accurately identify non-proportionally damped normal mode models. A new method to create predictive hybrid experimental/analytical models of damped structures is introduced, and the ability of hybrid models to predict the response to system configuration changes is discussed. Finally a critical review of the overall methodology is made by application to the case of the MIT/SERC interferometer testbed.
NASA Technical Reports Server (NTRS)
Elishakoff, Isaac; Lin, Y. K.; Zhu, Li-Ping; Fang, Jian-Jie; Cai, G. Q.
1994-01-01
This report supplements a previous report of the same title submitted in June, 1992. It summarizes additional analytical techniques which have been developed for predicting the response of linear and nonlinear structures to noise excitations generated by large propulsion power plants. The report is divided into nine chapters. The first two deal with incomplete knowledge of boundary conditions of engineering structures. The incomplete knowledge is characterized by a convex set, and its diagnosis is formulated as a multi-hypothesis discrete decision-making algorithm with attendant criteria of adaptive termination.
NASA Technical Reports Server (NTRS)
Fuller, C. R.
1986-01-01
The structural influence of the cabin floor on the transmission of low frequency propeller noise into aircraft interiors has been examined using a simplified analytical model. The response amplitudes and distributions of shell displacement and internal acoustic pressure are examined for various frequencies and floor configurations. In general, at lower frequencies the floor exerts little structural influence on the transmission of acoustic energy to the interior. However, as the frequency nears half the cylinder ring frequency the floor can be seen to significantly alter the internal pressure distributions and response.
NASA Astrophysics Data System (ADS)
Schur, W. W.
Effects of varying parameters in the design of super-pressure balloons of the "pumpkin" shape such as gore design, tendon stiffness, and structural lack-of-fit between tendons and gore seams are exhibited in analytical studies. The importance of an accurate representation of Poisson's effect for the film is demonstrated. Important design aspects that affect load paths and robustness of the design are discussed together with their resolution and quantification where applicable.
Robust mesoscopic superposition of strongly correlated ultracold atoms
Hallwood, David W.; Ernst, Thomas; Brand, Joachim
2010-12-15
We propose a scheme to create coherent superpositions of annular flow of strongly interacting bosonic atoms in a one-dimensional ring trap. The nonrotating ground state is coupled to a vortex state with mesoscopic angular momentum by means of a narrow potential barrier and an applied phase that originates from either rotation or a synthetic magnetic field. We show that superposition states in the Tonks-Girardeau regime are robust against single-particle loss due to the effects of strong correlations. The coupling between the mesoscopically distinct states scales much more favorably with particle number than in schemes relying on weak interactions, thus making particle numbers of hundreds or thousands feasible. Coherent oscillations induced by time variation of parameters may serve as a 'smoking gun' signature for detecting superposition states.
Optimal control of quantum superpositions in a bosonic Josephson junction
NASA Astrophysics Data System (ADS)
Lapert, M.; Ferrini, G.; Sugny, D.
2012-02-01
We show how to optimally control the creation of quantum superpositions in a bosonic Josephson junction within the two-site Bose-Hubbard-model framework. Both geometric and purely numerical optimal-control approaches are used, the former providing a generalization of the proposal of Micheli [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.67.013607 67, 013607 (2003)]. While this method is shown not to lead to significant improvements in terms of time of formation and fidelity of the superposition, a numerical optimal-control approach appears more promising, as it allows creation of an almost perfect superposition, within a time short compared to other existing protocols. We analyze the robustness of the optimal solution against atom-number variations. Finally, we discuss the extent to which these optimal solutions could be implemented with state-of-the-art technology.
Time-efficient flexible superposition of medium-sized molecules
NASA Astrophysics Data System (ADS)
Lemmen, Christian; Lengauer, Thomas
1997-07-01
We present an efficient algorithm for the structural alignment of medium-sized organic molecules. The algorithm has been developed for applications in 3D QSAR and in receptor modeling. The method assumes one of the molecules, the reference ligand, to be presented in the conformation that it adopts inside the receptor pocket. The second molecule, the test ligand, is considered to be flexible, and is assumed to be given in an arbitrary low-energy conformation. Ligand flexibility is modeled by decomposing the test ligand into molecular fragments, such that ring systems are completely contained in a single fragment. Conformations of fragments and torsional angles of single bonds are taken from a small finite set, which depends on the fragment and bond, respectively. The algorithm superimposes a distinguished base fragment of the test ligand onto a suitable region of the reference ligand and then attaches the remaining fragments of the test ligand in a step-by-step fashion. During this process, a scoring function is optimized that encompasses bonding terms and terms accounting for steric overlap as well as for similarity of chemical properties of both ligands. The algorithm has been implemented in the FLEXS system. To validate the quality of the produced results, we have selected a number of examples for which the mutual superposition of two ligands is experimentally given by the comparison of the binding geometries known from the crystal structures of their corresponding protein-ligand complexes. On more than two-thirds of the test examples the algorithm produces rms deviations of the predicted versus the observed conformation of the test ligand below 1.5 Å. The run time of the algorithm on a single problem instance is a few minutes on a common-day workstation. The overall goal of this research is to drastically reduce run times, while limiting the inaccuracies of the model and the computation to a tolerable level.
Dimensional limits for arthropod eyes with superposition optics.
Meyer-Rochow, Victor Benno; Gál, József
2004-01-01
An essential feature of the superposition type of compound eye is the presence of a wide zone, which is transparent and devoid of pigment and interposed between the distal array of dioptric elements and the proximally placed photoreceptive layer. Parallel rays, collected by many lenses, must (through reflection or refraction) cross this transparent clear-zone in such a way that they become focused on one receptor. Superposition depends mostly on diameter and curvature of the cornea, size and shape of the crystalline cone, lens cylinder properties of cornea and cone, dimensions of the receptor cells, and width of the clear-zone. We examined the role of the latter by geometrical, geometric-optical, and anatomical measurements and concluded that a minimal size exists, below which effective superposition can no longer occur. For an eye of a given size, it is not possible to increase the width of the clear-zone cz=dcz/R1 and decrease R2 (i.e., the radius of curvature of the distal retinal surface) and/or c=dc/R1 without reaching a limit. In the equations 'cz' is the width of the clear-zone dcz relative to the radius R1 of the eye and c is the length of the cornea-cone unit relative to R1. Our results provide one explanation as to why apposition eyes exist in very small scarabaeid beetles, when generally the taxon Scarabaeoidea is characterized by the presence of superposition eyes. The results may also provide the answer for the puzzle why juveniles or the young of species, in which the adults possess superposition (=clear-zone) eyes, frequently bear eyes that do not contain a clear zone, but resemble apposition eyes. The eyes of the young and immature specimens may simply be too small to permit superposition to occur.
Caporale, C
1998-11-01
The most recent algorithms based on the use of modern analytical techniques for the assessment of structural peptide and protein features have been reviewed. No algorithm devoted to the realization of predictive models or statistical analysis has been discussed, but only methods furnishing information on the real structure of the molecules. In particular, the procedures designed for handling sequence and mass spectrometric data obtained from the analysis of unfractionated digestion mixtures allow the user to get rapid information on the structure of the target polypeptide. Two classes of methods are illustrated: the first regards the determination of the amino acid sequence, whereas the second used its knowledge to supply data on the localization, function and three-dimensional structure of disulphides.
Superposition of helical beams by using a Michelson interferometer.
Gao, Chunqing; Qi, Xiaoqing; Liu, Yidong; Weber, Horst
2010-01-04
Orbital angular momentum (OAM) of a helical beam is of great interests in the high density optical communication due to its infinite number of eigen-states. In this paper, an experimental setup is realized to the information encoding and decoding on the OAM eigen-states. A hologram designed by the iterative method is used to generate the helical beams, and a Michelson interferometer with two Porro prisms is used for the superposition of two helical beams. The experimental results of the collinear superposition of helical beams and their OAM eigen-states detection are presented.
NASA Astrophysics Data System (ADS)
Ahmad, N.; Ali, Q.; Ashraf, M.; Alam, B.; Naeem, A.
2012-11-01
Half-Dressed rubble stone (DS) masonry structures as found in the Himalayan region are investigated using experimental and analytical studies. The experimental study included a shake table test on a one-third scaled structural model, a representative of DS masonry structure employed for public critical facilities, e.g. school buildings, offices, health care units, etc. The aim of the experimental study was to understand the damage mechanism of the model, develop damage scale towards deformation-based assessment and retrieve the lateral force-deformation response of the model besides its elastic dynamic properties, i.e. fundamental vibration period and elastic damping. The analytical study included fragility analysis of building prototypes using a fully probabilistic nonlinear dynamic method. The prototypes are designed as SDOF systems assigned with lateral, force-deformation constitutive law (obtained experimentally). Uncertainties in the constitutive law, i.e. lateral stiffness, strength and deformation limits, are considered through random Monte Carlo simulation. Fifty prototype buildings are analyzed using a suite of ten natural accelerograms and an incremental dynamic analysis technique. Fragility and vulnerability functions are derived for the damageability assessment of structures, economic loss and casualty estimation during an earthquake given the ground shaking intensity, essential within the context of risk assessment of existing stock aiming towards risk mitigation and disaster risk reduction.
NASA Astrophysics Data System (ADS)
Young, Meggie N.; Bleiholder, Christian
2017-03-01
Structure elucidation by ion mobility spectrometry-mass spectrometry methods is based on the comparison of an experimentally measured momentum transfer cross-section to cross-sections calculated for model structures. Thus, it is imperative that the calculated cross-section must be accurate. However, it is not fully understood how important it is to accurately model the charge distribution of an analyte ion when calculating momentum transfer cross-sections. Here, we calculate and compare momentum transfer cross-sections for carbon clusters that differ in mass, charge state, and mode of charge distribution, and vary temperature and polarizability of the buffer gas. Our data indicate that the detailed distribution of the ion charge density is intimately linked to the contribution of glancing collisions to the momentum transfer cross-section. The data suggest that analyte ions with molecular mass 3 kDa or momentum transfer cross-section 400-500 Å2 would be significantly influenced by the charge distribution in nitrogen buffer gas. Our data further suggest that accurate structure elucidation on the basis of IMS-MS data measured in nitrogen buffer gas must account for the molecular charge distribution even for systems as large as C960 ( 12 kDa) when localized charges are present and/or measurements are conducted under cryogenic temperatures. Finally, our data underscore that accurate structure elucidation is unlikely if ion mobility data recorded in one buffer gas is converted into other buffer gases when electronic properties of the buffer gases differ.
NASA Technical Reports Server (NTRS)
Platnick, S.
1999-01-01
Photon transport in a multiple scattering medium is critically dependent on scattering statistics, in particular the average number of scatterings. A superposition technique is derived to accurately determine the average number of scatterings encountered by reflected and transmitted photons within arbitrary layers in plane-parallel, vertically inhomogeneous clouds. As expected, the resulting scattering number profiles are highly dependent on cloud particle absorption and solar/viewing geometry. The technique uses efficient adding and doubling radiative transfer procedures, avoiding traditional time-intensive Monte Carlo methods. Derived superposition formulae are applied to a variety of geometries and cloud models, and selected results are compared with Monte Carlo calculations. Cloud remote sensing techniques that use solar reflectance or transmittance measurements generally assume a homogeneous plane-parallel cloud structure. The scales over which this assumption is relevant, in both the vertical and horizontal, can be obtained from the superposition calculations. Though the emphasis is on photon transport in clouds, the derived technique is applicable to any scattering plane-parallel radiative transfer problem, including arbitrary combinations of cloud, aerosol, and gas layers in the atmosphere.
Cheung, Mike W-L; Cheung, Shu Fai
2016-06-01
Meta-analytic structural equation modeling (MASEM) combines the techniques of meta-analysis and structural equation modeling for the purpose of synthesizing correlation or covariance matrices and fitting structural equation models on the pooled correlation or covariance matrix. Both fixed-effects and random-effects models can be defined in MASEM. Random-effects models are well known in conventional meta-analysis but are less studied in MASEM. The primary objective of this paper was to address issues related to random-effects models in MASEM. Specifically, we compared two different random-effects models in MASEM-correlation-based MASEM and parameter-based MASEM-and explored their strengths and limitations. Two examples were used to illustrate the similarities and differences between these models. We offered some practical guidelines for choosing between these two models. Future directions for research on random-effects models in MASEM were also discussed. Copyright © 2016 John Wiley & Sons, Ltd.
A novel analytical ultracentrifugation based approach to the low resolution structure of gum arabic.
Gillis, Richard B; Adams, Gary G; Alzahrani, Qushmua; Harding, Stephen E
2016-09-01
Under investigation are the structural properties of gum arabic, an industrially important biopolymer for use as a stabilizer or in drug delivery, using Analytical Ultracentrifugation-a well-established, matrix-free probe for macromolecular size and shape. These results are combined with chromatographically-coupled methods (multi-angle light scattering, differential press imbalance viscometry) to provide a global analysis of its structure in varying ionic strength conditions. This analysis indicates that gum Arabic may have a compact, elliptical structure in solution, the significance of which for biotechnological use is indicated. This modelling method can be applied to other biopolymers and synthetic polymers. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 618-625, 2016.
Stand dynamics and tree coexistence in an analytical structured model: the role of recruitment.
Angulo, Óscar; Bravo de la Parra, Rafael; López-Marcos, Juan C; Zavala, Miguel A
2013-09-21
Understanding the mechanisms of coexistence and niche partitioning in plant communities is a central question in ecology. Current theories of forest dynamics range between the so-called neutral theories which assume functional equivalence among coexisting species to forest simulators that explain species assemblages as the result of tradeoffs in species individual strategies at several ontogenetic stages. Progress in these questions has been hindered by the inherent difficulties of developing analytical size-structured models of stand dynamics. This precludes examination of the relative importance of each mechanism on tree coexistence. In previous simulation and analytical studies emphasis has been given to interspecific differences at the sapling stage, and less so to interspecific variation in seedling recruitment. In this study we develop a partial differential equation model of stand dynamics in which competition takes place at the recruitment stage. Species differ in their size-dependent growth rates and constant mortality rates. Recruitment is described as proportional to the basal area of conspecifics, to account for fecundity and seed supply per unit of basal area, and is corrected with a decreasing function of species specific basal area to account for competition. We first analyze conditions for population persistence in monospecific stands and second we investigate conditions of coexistence for two species. In the monospecific case we found a stationary stand structure based on an inequality between mortality rate and seed supply. In turn, intra-specific competition does not play any role on the asymptotic extinction or population persistence. In the two-species case we found that coexistence can be attained when the reciprocal negative effect on recruitment follows a given relation with respect to intraspecific competition. Specifically a tradeoff between recruitment potential (i.e. shade tolerance or predation avoidance) and fecundity or growth rate
A (semi)-analytic view of the inner structure of Pulsar Wind Nebulae
NASA Astrophysics Data System (ADS)
Bandiera, R.; Olmi, B.; del Zanna, L.; Bucciantini, N.; Amato, E.
2016-06-01
When the wind of an active pulsar impacts on the surrounding medium, it forms a termination shock (TS) that feeds a relativistic and magnetized bubble, known as "Pulsar Wind Nebula". About thirty years ago, Kennel Coroniti investigated this scenario, but unfortunately their results failed to match the observed morphologies. That model was in principle correct, but its main drawback was the assumption of a spherical symmetry. More recently, numerical codes have been used to simulate in detail the dynamical structure of PWNe: they have shown complex morphologies, with a closer resemblance with observations. We show how Kennel Coroniti model can be generalized to two dimensions, by solving the jump equations for an oblique TS, and then the relativistic MHD equations in the downstream regions closest to the TS. In this way we can obtain two dimensional, steady state solutions, which in the inner regions agree quite well with the numerical ones. This method is semi-analytic and computationally rather light: given the shape of the TS (in an analytic form), the spatial behaviour of the physical quantities (like velocity, pressure, magnetic field) is derived. Maps of the synchrotron emission are also obtained. A final goal is to use semi-analytic modelling, together with numerical simulations, to improve inversion techniques, aimed at deriving the pulsar-wind parameters from observations.
Measuring orbital angular momentum superpositions of light by mode transformation.
Berkhout, Gregorius C G; Lavery, Martin P J; Padgett, Miles J; Beijersbergen, Marco W
2011-05-15
We recently reported on a method for measuring orbital angular momentum (OAM) states of light based on the transformation of helically phased beams to tilted plane waves [Phys. Rev. Lett.105, 153601 (2010)]. Here we consider the performance of such a system for superpositions of OAM states by measuring the modal content of noninteger OAM states and beams produced by a Heaviside phase plate.
Real-time feedback control of a mesoscopic superposition
Jacobs, Kurt; Finn, Justin; Vinjanampathy, Sai
2011-04-15
We show that continuous real-time feedback can be used to track, control, and protect a mesoscopic superposition of two spatially separated wave packets. The feedback protocol is enabled by an approximate state estimator and requires two continuous measurements, performed simultaneously. For nanomechanical and superconducting resonators, both measurements can be implemented by coupling the resonators to superconducting qubits.
Analytical and Numerical Evaluation of Limit States of MSE Wall Structure
NASA Astrophysics Data System (ADS)
Drusa, Marián; Vlček, Jozef; Holičková, Martina; Kais, Ladislav
2016-12-01
Simplification of the design of Mechanically Stabilized Earth wall structures (MSE wall or MSEW) is now an important factor that helps us not only to save a time and costs, but also to achieve the desired results more reliably. It is quite common way in practice, that the designer of a section of motorway or railway line gives order for design to a supplier of geosynthetics materials. However, supplier company has experience and skills, but a general designer does not review the safety level of design and its efficiency, and is simply incorporating into the overall design of the construction project. Actually, large number of analytical computational methods for analysis and design of MSE walls or similar structures are known. The problem of these analytical methods is the verification of deformations and global stability of structure. The article aims to clarify two methods of calculating the internal stability of MSE wall and their comparison with FEM numerical model. Comparison of design approaches allows us to draft an effective retaining wall and tells us about the appropriateness of using a reinforcing element.
NASA Astrophysics Data System (ADS)
Piet, David L.
Ferromagnetic microparticles suspended at the interface between immiscible liquids and energized by an external alternating magnetic field show a rich variety of self-assembled structures, from linear snakes to radial asters, elongated wires to spinning chains to less dense clouds of particles called snails. In order to obtain insight into the fundamental physical mechanisms and the overall balance of forces governing self-assembly, we develop a modeling approach based on analytical solutions of the time-averaged Navier-Stokes equations. These analytical expressions for the self-consistent hydrodynamic flows are then employed to modify effective interactions between the particles, which in turn are formulated in terms of the time-averaged quantities. Our method allows effective computational verification of the mechanisms of self-assembly and leads to a testable predictions on the transitions between various self-assembled patterns. In one set of experiments, it was observed that viscosity is the primary driving force that determines whether asters or snakes appear at steady state. In the second set of experiments where hydrodynamics are less critical, the amplitude and frequency of the applied magnetic field determine whether wires, spinners or snails will appear. The ability to better understand what drives self-assembly and how to control which dynamic structures appear is necessary for further development of such structures and their applications.
Analytic structure of the S-matrix for singular quantum mechanics
Camblong, Horacio E.; Epele, Luis N.; Fanchiotti, Huner; García Canal, Carlos A.
2015-06-15
The analytic structure of the S-matrix of singular quantum mechanics is examined within a multichannel framework, with primary focus on its dependence with respect to a parameter (Ω) that determines the boundary conditions. Specifically, a characterization is given in terms of salient mathematical and physical properties governing its behavior. These properties involve unitarity and associated current-conserving Wronskian relations, time-reversal invariance, and Blaschke factorization. The approach leads to an interpretation of effective nonunitary solutions in singular quantum mechanics and their determination from the unitary family.
Semi-analytic approach for electromagnetic problems of large arrays structures
NASA Astrophysics Data System (ADS)
Rostami-Angas, Masoud
helps us in finding the microscopic charactristics of the structure. Building on the theory that the molecules can be modeled by electric dipoles; a semi-analytic and semi-classical approach is developed to solve the electromagnetic problem of large array of dipoles and simulate the optical response of molecular aggregates. In chapter 3, a double negative (DNG) metamaterial structure is designed by unit cells of multilayer (concentric) spheres. The dispersion diagram is analyzed to find the frequency band with negative group velocity and the losses in DNG region. Basically, the combination of a positive permittivity dielectric and a negative permittivity plasmonic material can control the resonances of unit cells and therefore the effective permittivity of the 3-D structure. It is also discussed how a novel design of multilayer sphere unit cells leads to the DNG performance at the desired frequency band. In chapter 4, analytical solution to the problem of electromagnetic wave scattering by an arbitrary array of non-concentric spheres is derived. A full wave multipole expansion method is applied to express the electromagnetic fields in terms of the electric and magnetic dipole modes and the higher order moments. Vector spherical wave functions are used as the basis functions of the multipole expansions and the translation addition theorem is implemented to expand fields in desired coordinate systems. The accuracy and computational performance of the model are investigated and some interesting applications are discussed.
NASA Astrophysics Data System (ADS)
Trombetti, Tomaso
This thesis presents an Experimental/Analytical approach to modeling and calibrating shaking tables for structural dynamic applications. This approach was successfully applied to the shaking table recently built in the structural laboratory of the Civil Engineering Department at Rice University. This shaking table is capable of reproducing model earthquake ground motions with a peak acceleration of 6 g's, a peak velocity of 40 inches per second, and a peak displacement of 3 inches, for a maximum payload of 1500 pounds. It has a frequency bandwidth of approximately 70 Hz and is designed to test structural specimens up to 1/5 scale. The rail/table system is mounted on a reaction mass of about 70,000 pounds consisting of three 12 ft x 12 ft x 1 ft reinforced concrete slabs, post-tensioned together and connected to the strong laboratory floor. The slip table is driven by a hydraulic actuator governed by a 407 MTS controller which employs a proportional-integral-derivative-feedforward-differential pressure algorithm to control the actuator displacement. Feedback signals are provided by two LVDT's (monitoring the slip table relative displacement and the servovalve main stage spool position) and by one differential pressure transducer (monitoring the actuator force). The dynamic actuator-foundation-specimen system is modeled and analyzed by combining linear control theory and linear structural dynamics. The analytical model developed accounts for the effects of actuator oil compressibility, oil leakage in the actuator, time delay in the response of the servovalve spool to a given electrical signal, foundation flexibility, and dynamic characteristics of multi-degree-of-freedom specimens. In order to study the actual dynamic behavior of the shaking table, the transfer function between target and actual table accelerations were identified using experimental results and spectral estimation techniques. The power spectral density of the system input and the cross power spectral
Verma, T.; Painuly, N.K.; Mishra, S.P.; Shajahan, M.; Singh, N.; Bhatt, M.L.B.; Jamal, N.; Pant, M.C.
2016-01-01
Background: Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. Objective: In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy planning. Materials and Methods: Treatment plans for ten lung cancer patients previously planned on Monte Carlo algorithm were re-planned using same treatment planning indices (gantry angel, rank, power etc.) in other four algorithms. Results: The values of radiotherapy planning parameters such as Mean dose, volume of 95% isodose line, Conformity Index, Homogeneity Index for target, Maximum dose, Mean dose; %Volume receiving 20Gy or more by contralateral lung; % volume receiving 30 Gy or more; % volume receiving 25 Gy or more, Mean dose received by heart; %volume receiving 35Gy or more; %volume receiving 50Gy or more, Mean dose to Easophagous; % Volume receiving 45Gy or more, Maximum dose received by Spinal cord and Total monitor unit, Volume of 50 % isodose lines were recorded for all ten patients. Performance of different algorithms was also evaluated statistically. Conclusion: MC and PB algorithms found better as for tumor coverage, dose distribution homogeneity in Planning Target Volume and minimal dose to organ at risks are concerned. Superposition algorithms found to be better than convolution and fast superposition. In the case of tumors located centrally, it is recommended to use Monte Carlo algorithms for the optimal use of radiotherapy. PMID:27853720
Analytical study of structural control with toggle mechanism for retrofiting existing R/C structures
NASA Astrophysics Data System (ADS)
Kubota, Masaharu; Ishimaru, Shinji; Niiya, Takahito; Nakagawa, Mitsuo; Maekawa, Yasuo
1999-05-01
The proposed toggle vibration controller is an excellent vibration-controlling device that efficiently absorbs seismic energy input into a building by amplifying small relative story displacements using a lever mechanism. And we tried to adopt the toggle mechanism as a lever mechanism. This is a brace-shaped passive response-controller installed in a column-beam frame of a building. It can minimize the response displacement and response acceleration by earthquakes, and is applicable independently of the type of construction, including steel-framed structures and reinforced concrete structures. The response-controlling effect is excellent for both newly built structures and seismic retrofit. This paper reports on seismic retrofit of existing reinforced concrete buildings using these devices.
NASA Technical Reports Server (NTRS)
Williams, J. G.; Mikulus, M. M., Jr.
1976-01-01
Structural efficiency studies were made to determine the weight saving potential of graphite/epoxy composite structures for compression panel applications. Minimum weight hat-stiffened and open corrugation configurations were synthesized using a nonlinear mathematical programming technique. Selected configurations were built and tested to study local and Euler buckling characteristics. Test results for 23 panels critical in local buckling and six panels critical in Euler buckling are compared with analytical results obtained using the BUCLASP-2 branched plate buckling program. A weight efficiency comparison is made between composite and aluminum compression panels using metal test data generated by the NACA. Theoretical studies indicate that potential weight savings of up to 50% are possible for composite hat-stiffened panels when compared with similar aluminum designs. Weight savings of 32% to 42% were experimentally achieved. Experience suggests that most of the theoretical weight saving potential is available if design deficiencies are eliminated and strict fabrication control is exercised.
Analytical theory of self-consistent current structures in a collisionless plasma
NASA Astrophysics Data System (ADS)
Kocharovsky, V. V.; Kocharovsky, Vl V.; Martyanov, V. Yu; Tarasov, S. V.
2017-03-01
The most-studied classes of exact solutions to Vlasov–Maxwell equations for stationary neutral current structures in a collisionless relativistic plasma, which allow the particle distribution functions (PDFs) to be chosen at will, are reviewed. A general classification is presented of the current sheets and filaments described by the method of invariants of motion of particles whose PDF is symmetric in a certain way in coordinate and momentum spaces. The possibility is discussed of using these explicit solutions to model the observed and/or expected features of current structures in cosmic and laboratory plasmas. Also addressed are how the magnetic field forms and the analytical description of the so-called Weibel instability in a plasma with an arbitrary PDF.
The structure of temperament in preschoolers: a two-stage factor analytic approach.
Dyson, Margaret W; Olino, Thomas M; Durbin, C Emily; Goldsmith, H Hill; Klein, Daniel N
2012-02-01
The structure of temperament traits in young children has been the subject of extensive debate, with separate models proposing different trait dimensions. This research has relied almost exclusively on parent-report measures. The present study used an alternative approach, a laboratory observational measure, to explore the structure of temperament in preschoolers. A 2-stage factor analytic approach, exploratory factor analyses (n = 274) followed by confirmatory factor analyses (n = 276), was used. We retrieved an adequately fitting model that consisted of 5 dimensions: Sociability, Positive Affect/Interest, Dysphoria, Fear/Inhibition, and Constraint versus Impulsivity. This solution overlaps with, but is also distinct from, the major models derived from parent-report measures.
Analytical theory of self-consistent current structures in a collisionless plasma
NASA Astrophysics Data System (ADS)
Kocharovsky, V. V.; Kocharovsky, V. V.; Martyanov, V. Yu; Tarasov, S. V.
2016-12-01
The most-studied classes of exact solutions to Vlasov – Maxwell equations for stationary neutral current structures in a collisionless relativistic plasma, which allow the particle distribution functions (PDFs) to be chosen at will, are reviewed. A general classification is presented of the current sheets and filaments described by the method of invariants of motion of particles whose PDF is symmetric in a certain way in coordinate and momentum spaces. The possibility is discussed of using these explicit solutions to model the observed and/or expected features of current structures in cosmic and laboratory plasmas. Also addressed are how the magnetic field forms and the analytical description of the so-called Weibel instability in a plasma with an arbitrary PDF.
Young, Meggie N; Bleiholder, Christian
2017-04-01
Structure elucidation by ion mobility spectrometry-mass spectrometry methods is based on the comparison of an experimentally measured momentum transfer cross-section to cross-sections calculated for model structures. Thus, it is imperative that the calculated cross-section must be accurate. However, it is not fully understood how important it is to accurately model the charge distribution of an analyte ion when calculating momentum transfer cross-sections. Here, we calculate and compare momentum transfer cross-sections for carbon clusters that differ in mass, charge state, and mode of charge distribution, and vary temperature and polarizability of the buffer gas. Our data indicate that the detailed distribution of the ion charge density is intimately linked to the contribution of glancing collisions to the momentum transfer cross-section. The data suggest that analyte ions with molecular mass ~3 kDa or momentum transfer cross-section 400-500 Å(2) would be significantly influenced by the charge distribution in nitrogen buffer gas. Our data further suggest that accurate structure elucidation on the basis of IMS-MS data measured in nitrogen buffer gas must account for the molecular charge distribution even for systems as large as C960 (~12 kDa) when localized charges are present and/or measurements are conducted under cryogenic temperatures. Finally, our data underscore that accurate structure elucidation is unlikely if ion mobility data recorded in one buffer gas is converted into other buffer gases when electronic properties of the buffer gases differ. Graphical Abstract ᅟ.
Zhu, Zhenyu; Ravelet, Corinne; Perrier, Sandrine; Guieu, Valérie; Roy, Béatrice; Perigaud, Christian; Peyrin, Eric
2010-06-01
Affinity probe capillary electrophoresis (APCE) assays, combining the separation power of CE with the specificity of interactions occurring between a target and a molecular recognition element (MRE), have become important analytical tools in many application fields. In this report, a rationalized strategy, derived from the structure-switching aptamer concept, is described for the design of a novel APCE mode dedicated to small molecule detection. Two assay configurations were reported. The first one, developed for the single-analyte determination, was based on the use of a cholesteryl-tagged aptamer (Chol-Apt) as the MRE and its fluorescein-labeled complementary strand (CS*) as the tracer (laser-induced fluorescence detection). Under micellar electrokinetic chromatography (MEKC) conditions, free CS* and the hybrid formed with Chol-Apt (duplex*) were efficiently separated (and then quantified) through the specific shift of the electrophoretic mobility of the cholesteryl-tagged species in the presence of a neutral micellar phase. When the target was introduced into the preincubated sample, the hybridized form was destabilized, resulting in a decrease in the duplex* peak area and a concomitant increase in the free CS* peak area. The second format, especially designed for multianalyte sensing, employed dually cholesteryl- and fluorescein-labeled complementary strands (Chol-CS*) of different lengths and unmodified aptamers (Apt). The size-dependent electrophoretic separation of different Chol-CS* forms from each other and from their corresponding duplexes* was also accomplished under MEKC conditions. The simultaneous detection of multiple analytes in a single capillary was performed by monitoring accurately each target-induced duplex-to-complex change. This method could expand significantly the potential of small solute APCE analysis in terms of simplicity, adaptability, generalizability, and high-throughput analysis capability.
A stereo triangulation system for structural identification: Analytical and experimental results
NASA Technical Reports Server (NTRS)
Junkins, J. L.; James, G. H., III; Pollock, T. C.; Rahman, Z. H.
1988-01-01
Identification of large space structures' distributed mass, stiffness, and energy dissipation characteristics poses formidable analytical, numerical, and implementation difficulties. Development of reliable on-orbit structural identification methods is important for implementing active vibration suppression concepts which are under widespread study in the large space structures community. Near the heart of the identification problem lies the necessity of making a large number of spatially distributed measurements of the structure's vibratory response and the associated force/moment inputs with sufficient spatial and frequency resolution. In the present paper, we discuss a method whereby tens of active or passive (retro-reflecting) targets on the structure are tracked simultaneously by the focal planes of two or more video cameras mounted on an adjacent platform. Triangulation (optical ray intersection) of the conjugate image centroids yield inertial trajectories of each target on the structure. Given the triangulated motion of the targets, we apply and extend methodology developed by Creamer, Junkins, and Juang to identify the frequencies, mode shapes, and updated estimates for the mass/stiffness/damping parameterization of the structure. The methodology is semi-automated, for example, the post experiment analysis of the video imagery to determine the inertial trajectories of the targets typically requires less than thirty minutes of real time. Using methodology discussed herein, the frequency response of a large number of points on the structure (where reflective targets are mounted) on the structure can be determined from optical measurements alone. For comparison purposes, we also utilize measurements from accelerometers and a calibrated impulse hammer. While our experimental work remains in a research stage of development, we have successfully tracked and stereo triangulated 20 targets (on a vibrating cantilevered grid structure) at a sample frequency of 200 HZ
Nonclassicality tests and entanglement witnesses for macroscopic mechanical superposition states
NASA Astrophysics Data System (ADS)
Gittsovich, Oleg; Moroder, Tobias; Asadian, Ali; Gühne, Otfried; Rabl, Peter
2015-02-01
We describe a set of measurement protocols for performing nonclassicality tests and the verification of entangled superposition states of macroscopic continuous variable systems, such as nanomechanical resonators. Following earlier works, we first consider a setup where a two-level system is used to indirectly probe the motion of the mechanical system via Ramsey measurements and discuss the application of this method for detecting nonclassical mechanical states. We then show that the generalization of this technique to multiple resonator modes allows the conditioned preparation and the detection of entangled mechanical superposition states. The proposed measurement protocols can be implemented in various qubit-resonator systems that are currently under experimental investigation and find applications in future tests of quantum mechanics at a macroscopic scale.
NASA Technical Reports Server (NTRS)
Johnston, John D.; Blandino, Joseph R.; McEvoy, Kiley C.
2004-01-01
The development of gossamer space structures such as solar sails and sunshields presents many challenges due to their large size and extreme flexibility. The post-deployment structural geometry exhibited during ground testing may significantly depart from the in-space configuration due to the presence of gravity-induced deformations (gravity sag) of lightly preloaded membranes. This paper describes a study carried out to characterize gravity sag in two subscale gossamer structures: a single quadrant from a 2 m, 4 quadrant square solar sail and a 1.7 m membrane layer from a multi-layer sunshield The behavior of the test articles was studied over a range of preloads and in several orientations with respect to gravity. An experimental study was carried out to measure the global surface profiles using photogrammetry, and nonlinear finite element analysis was used to predict the behavior of the test articles. Comparison of measured and predicted surface profiles shows that the finite dement analysis qualitatively predicts deformed shapes comparable to those observed in the laboratory. Quantitatively, finite element analysis predictions for peak gravity-induced deformations in both test articles were within 10% of measured values. Results from this study provide increased insight into gravity sag behavior in gossamer structures, and demonstrates the potential to analytically predict gravity-induced deformations to within reasonable accuracy.
Analytical solutions for the seismic response of underground structures under SH wave propagation
Smerzini, C.; Aviles, J.; Sanchez-Sesma, F. J.
2008-07-08
A theoretical approach is presented to study the antiplane seismic response of underground structures subjected to the incidence of plane waves. The structure is assumed to be a circular inclusion embedded in a homogenous, isotropic and linear visco-elastic halfspace and its mathematical formulation is approached through the theory of multiple scattering and diffraction. The inclusion may consist either of a cavity, with or without a ring-shaped boundary, or it may be filled in with a linear-elastic material, without loss of generality. The seismic response of the inclusion and its influence on surface ground motions are analyzed in both frequency and time domains. The dependence of the transfer function amplitudes on several parameters, such as the angle of incident SH waves, the frequency content of the excitation, the impedance contrast between the inclusion and the surrounding medium and the position along the ground surface, is underlined. Considering the lack of analytical solutions for quantifying the modification of ground motions induced by subterranean inhomogeneities, the results of this study can be used, on one side, as benchmark for both geophysical investigations and numerical dynamic soil-structure interaction studies, and, on the other side, to support the formulation of simplified approaches and/or formulas for the seismic design and assessment of underground structures.
NASA Astrophysics Data System (ADS)
Brouwers, H. J. H.
2007-10-01
The geometrical stability of the three lattices of the cubic crystal system, viz. face-centered cubic (fcc), body-centered cubic (bcc), and simple cubic (sc), consisting of bimodal discrete hard spheres, and the transition to amorphous packing is studied. First, the random close packing (rcp) fraction of binary mixtures of amorphously packed spheres is recapitulated. Next, the packing of a binary mixture of hard spheres in randomly disordered cubic structures is analyzed, resulting in original analytical expressions for the unit cell volume and the packing fraction, and which are also valid for the other five crystal systems. The bimodal fcc lattice parameter appears to be in close agreement with empirical hard sphere data from literature, and this parameter could be used to distinguish the size mismatch effect from all other effects in distorted binary lattices of materials. Here, as a first model application, bimodal amorphous and crystalline fcc/bcc packing fractions are combined, yielding the optimum packing configuration, which depends on mixture composition and diameter ratio only. Maps of the closest packing mode are established and applied to colloidal mixtures of polydisperse spheres and to binary alloys of bcc, fcc, and hcp metals. The extensive comparison between the analytical expressions derived here and the published numerical and empirical data yields good agreement. Hence, it is seen that basic space-filling theories on “simple” noninteracting hard spheres are a valuable tool for the study of crystalline materials.
Brouwers, H J H
2007-10-01
The geometrical stability of the three lattices of the cubic crystal system, viz. face-centered cubic (fcc), body-centered cubic (bcc), and simple cubic (sc), consisting of bimodal discrete hard spheres, and the transition to amorphous packing is studied. First, the random close packing (rcp) fraction of binary mixtures of amorphously packed spheres is recapitulated. Next, the packing of a binary mixture of hard spheres in randomly disordered cubic structures is analyzed, resulting in original analytical expressions for the unit cell volume and the packing fraction, and which are also valid for the other five crystal systems. The bimodal fcc lattice parameter appears to be in close agreement with empirical hard sphere data from literature, and this parameter could be used to distinguish the size mismatch effect from all other effects in distorted binary lattices of materials. Here, as a first model application, bimodal amorphous and crystalline fcc/bcc packing fractions are combined, yielding the optimum packing configuration, which depends on mixture composition and diameter ratio only. Maps of the closest packing mode are established and applied to colloidal mixtures of polydisperse spheres and to binary alloys of bcc, fcc, and hcp metals. The extensive comparison between the analytical expressions derived here and the published numerical and empirical data yields good agreement. Hence, it is seen that basic space-filling theories on "simple" noninteracting hard spheres are a valuable tool for the study of crystalline materials.
Measurement-Induced Macroscopic Superposition States in Cavity Optomechanics
NASA Astrophysics Data System (ADS)
Hoff, Ulrich B.; Kollath-Bönig, Johann; Neergaard-Nielsen, Jonas S.; Andersen, Ulrik L.
2016-09-01
A novel protocol for generating quantum superpositions of macroscopically distinct states of a bulk mechanical oscillator is proposed, compatible with existing optomechanical devices operating in the bad-cavity limit. By combining a pulsed optomechanical quantum nondemolition (QND) interaction with nonclassical optical resources and measurement-induced feedback, the need for strong single-photon coupling is avoided. We outline a three-pulse sequence of QND interactions encompassing squeezing-enhanced cooling by measurement, state preparation, and tomography.
Sensing Super-position: Visual Instrument Sensor Replacement
NASA Technical Reports Server (NTRS)
Maluf, David A.; Schipper, John F.
2006-01-01
The coming decade of fast, cheap and miniaturized electronics and sensory devices opens new pathways for the development of sophisticated equipment to overcome limitations of the human senses. This project addresses the technical feasibility of augmenting human vision through Sensing Super-position using a Visual Instrument Sensory Organ Replacement (VISOR). The current implementation of the VISOR device translates visual and other passive or active sensory instruments into sounds, which become relevant when the visual resolution is insufficient for very difficult and particular sensing tasks. A successful Sensing Super-position meets many human and pilot vehicle system requirements. The system can be further developed into cheap, portable, and low power taking into account the limited capabilities of the human user as well as the typical characteristics of his dynamic environment. The system operates in real time, giving the desired information for the particular augmented sensing tasks. The Sensing Super-position device increases the image resolution perception and is obtained via an auditory representation as well as the visual representation. Auditory mapping is performed to distribute an image in time. The three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. This paper details the approach of developing Sensing Super-position systems as a way to augment the human vision system by exploiting the capabilities of the human hearing system as an additional neural input. The human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns. The known capabilities of the human hearing system to learn and understand complicated auditory patterns provided the basic motivation for developing an
Single-Atom Gating of Quantum State Superpositions
Moon, Christopher
2010-04-28
The ultimate miniaturization of electronic devices will likely require local and coherent control of single electronic wavefunctions. Wavefunctions exist within both physical real space and an abstract state space with a simple geometric interpretation: this state space - or Hilbert space - is spanned by mutually orthogonal state vectors corresponding to the quantized degrees of freedom of the real-space system. Measurement of superpositions is akin to accessing the direction of a vector in Hilbert space, determining an angle of rotation equivalent to quantum phase. Here we show that an individual atom inside a designed quantum corral1 can control this angle, producing arbitrary coherent superpositions of spatial quantum states. Using scanning tunnelling microscopy and nanostructures assembled atom-by-atom we demonstrate how single spins and quantum mirages can be harnessed to image the superposition of two electronic states. We also present a straightforward method to determine the atom path enacting phase rotations between any desired state vectors. A single atom thus becomes a real-space handle for an abstract Hilbert space, providing a simple technique for coherent quantum state manipulation at the spatial limit of condensed matter.
WHAEM: PROGRAM DOCUMENTATION FOR THE WELLHEAD ANALYTIC ELEMENT MODEL
The Wellhead Analytic Element Model (WhAEM) demonstrates a new technique for the definition of time-of-travel capture zones in relatively simple geohydrologic settings. he WhAEM package includes an analytic element model that uses superposition of (many) analytic solutions to gen...
IT vendor selection model by using structural equation model & analytical hierarchy process
NASA Astrophysics Data System (ADS)
Maitra, Sarit; Dominic, P. D. D.
2012-11-01
Selecting and evaluating the right vendors is imperative for an organization's global marketplace competitiveness. Improper selection and evaluation of potential vendors can dwarf an organization's supply chain performance. Numerous studies have demonstrated that firms consider multiple criteria when selecting key vendors. This research intends to develop a new hybrid model for vendor selection process with better decision making. The new proposed model provides a suitable tool for assisting decision makers and managers to make the right decisions and select the most suitable vendor. This paper proposes a Hybrid model based on Structural Equation Model (SEM) and Analytical Hierarchy Process (AHP) for long-term strategic vendor selection problems. The five steps framework of the model has been designed after the thorough literature study. The proposed hybrid model will be applied using a real life case study to assess its effectiveness. In addition, What-if analysis technique will be used for model validation purpose.
Limitations to the validity of single wake superposition in wind farm yield assessment
NASA Astrophysics Data System (ADS)
Gunn, K.; Stock-Williams, C.; Burke, M.; Willden, R.; Vogel, C.; Hunter, W.; Stallard, T.; Robinson, N.; Schmidt, S. R.
2016-09-01
Commercially available wind yield assessment models rely on superposition of wakes calculated for isolated single turbines. These methods of wake simulation fail to account for emergent flow physics that may affect the behaviour of multiple turbines and their wakes and therefore wind farm yield predictions. In this paper wake-wake interaction is modelled computationally (CFD) and physically (in a hydraulic flume) to investigate physical causes of discrepancies between analytical modelling and simulations or measurements. Three effects, currently neglected in commercial models, are identified as being of importance: 1) when turbines are directly aligned, the combined wake is shortened relative to the single turbine wake; 2) when wakes are adjacent, each will be lengthened due to reduced mixing; and 3) the pressure field of downstream turbines can move and modify wakes flowing close to them.
Yin, H-L; Cao, W-F; Fu, Y; Tang, Y-L; Liu, Y; Chen, T-Y; Chen, Z-B
2014-09-15
Measurement-device-independent quantum key distribution (MDI-QKD) with decoy-state method is believed to be securely applied to defeat various hacking attacks in practical quantum key distribution systems. Recently, the coherent-state superpositions (CSS) have emerged as an alternative to single-photon qubits for quantum information processing and metrology. Here, in this Letter, CSS are exploited as the source in MDI-QKD. We present an analytical method that gives two tight formulas to estimate the lower bound of yield and the upper bound of bit error rate. We exploit the standard statistical analysis and Chernoff bound to perform the parameter estimation. Chernoff bound can provide good bounds in the long-distance MDI-QKD. Our results show that with CSS, both the security transmission distance and secure key rate are significantly improved compared with those of the weak coherent states in the finite-data case.
Shake table tests and analytical simulations of a steel structure with shape memory alloy dampers
NASA Astrophysics Data System (ADS)
Parulekar, Y. M.; Kiran, A. Ravi; Reddy, G. R.; Singh, R. K.; Vaze, K. K.
2014-12-01
This study uses the pseudoelastic properties of Ni-Ti shape memory alloy wires for attenuation of the seismic response of a steel structure and evaluates its effectiveness and applicability in seismic response control. In this paper, shake table tests, carried out on a model of a steel structure with and without wire-based shape memory alloy dampers, are discussed in detail. Shake table tests, comprised of free vibration tests and spectrum compatible time history tests, were carried out. The former were used for the evaluation of the frequency and damping, and the later were used to prove the efficacy of the shape memory alloy dampers. Further analytical simulations are carried out using detailed time history analysis utilizing a thermomechanical model of an SMA and taking into account the residual martensite accumulation, which is irreversibly due to cyclic forward/reverse martensitic transformation. Moreover, a simple iterative response spectrum (IRS) method with equivalent damping and stiffness is also used to evaluate the response of the structure with SMA dampers, and it is proved that the method can be conservatively used by designers.
NASA Astrophysics Data System (ADS)
Sotnikov, V.; Kim, T.; Lundberg, J.; Paraschiv, I.; Mehlhorn, T.
2014-09-01
The presence of plasma turbulence can strongly influence propagation properties of electromagnetic signals used for surveillance and communication. In particular, we are interested in the generation of low frequency plasma density irregularities in the form of coherent vortex structures. Interchange or flute type density irregularities in magnetized plasma are associated with Rayleigh-Taylor type instability. These types of density irregularities play important role in refraction and scattering of high frequency electromagnetic signals propagating in the earth ionosphere, in high energy density physics (HEDP) and in many other applications. We will discuss scattering of high frequency electromagnetic waves on low frequency density irregularities due to the presence of vortex density structures associated with interchange instability. We will also present PIC simulation results on EM scattering on vortex type density structures using the LSP code and compare them with analytical results. Acknowledgement: This work was supported by the Air Force Research laboratory, the Air Force Office of Scientific Research, the Naval Research Laboratory and NNSA/DOE grant no. DE-FC52-06NA27616 at the University of Nevada at Reno.
NASA Astrophysics Data System (ADS)
Liang, Guanhao; Wang, Yancheng; Mei, Deqing; Xi, Kailun; Chen, Zichen
2016-04-01
This paper presents an analytical model to study the structural effects of a capacitive tactile sensor array on its capacitance changes and sensitivities. The tactile sensor array has 8 × 8 sensor units, and each unit utilizes the truncated polydimethylsiloxane (PDMS) pyramid array structure as the dielectric layer to enhance the sensing performance. To predict the capacitance changes of the sensor unit, it is simplified into a two-layered structure: upper polyethylene terephthalate (PET) film and bottom truncated PDMS pyramid array. The upper PET is modeled by a displacement field function, while each of the truncated pyramids is analyzed to obtain its stress-strain relation. Using the Ritz method, the displacement field functions are solved. The deformation of the upper electrodes and the capacitance changes of the sensor unit can then be calculated. Using the developed model, the structural effects of the truncated PDMS pyramid array and the PDMS bump on the capacitance changes and sensitivities are studied. To achieve the largest capacitance changes, the dimensions have been optimized for the sensor unit. To verify the developed model, we have fabricated the sensor array, and the average sensitivities of the sensor unit to the x-, y-, and z-axes force are 0.49, 0.50, and 0.32% mN-1, respectively, while the model predicted values are 0.54, 0.54, and 0.35% mN-1. Results demonstrate that the developed model can accurately predict the sensing performance of the sensor array and could be utilized for structural optimization.
NASA Technical Reports Server (NTRS)
Flannelly, W. G.; Fabunmi, J. A.; Nagy, E. J.
1981-01-01
Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described.
Analytic study of the effect of dark energy-dark matter interaction on the growth of structures
NASA Astrophysics Data System (ADS)
Marcondes, Rafael J. F.; Landim, Ricardo C. G.; Costa, André A.; Wang, Bin; Abdalla, Elcio
2016-12-01
Large-scale structure has been shown as a promising cosmic probe for distinguishing and constraining dark energy models. Using the growth index parametrization, we obtain an analytic formula for the growth rate of structures in a coupled dark energy model in which the exchange of energy-momentum is proportional to the dark energy density. We find that the evolution of fσ8 can be determined analytically once we know the coupling, the dark energy equation of state, the present value of the dark energy density parameter and the current mean amplitude of dark matter fluctuations. After correcting the growth function for the correspondence with the velocity field through the continuity equation in the interacting model, we use our analytic result to compare the model's predictions with large-scale structure observations.
NASA Astrophysics Data System (ADS)
Boot, C. M.
2012-12-01
Microorganisms are the primary transformers of organic matter in terrestrial and aquatic ecosystems. The structure of organic matter controls its bioavailability and researchers have long sought to link the chemical characteristics of the organic matter pool to its lability. To date this effort has been primarily attempted using low resolution descriptive characteristics (e.g. organic matter content, carbon to nitrogen ratio, aromaticity, etc .). However, recent progress in linking these two important ecosystem components has been advanced using advanced high resolution tools (e.g. nuclear magnetic resonance (NMR) spectroscopy, and mass spectroscopy (MS)-based techniques). A series of experiments will be presented that highlight the application of high resolution techniques in a variety of terrestrial and aquatic ecosystems with the focus on how these data explicitly provide the foundation for integrating organic matter structure into our concept of ecosystem function. The talk will highlight results from a series of experiments including: an MS-based metabolomics and fluorescence excitation emission matrix approach evaluating seasonal and vegetation based changes in dissolved organic matter (DOM) composition from arctic soils; Fourier transform ion cyclotron resonance (FTICR) MS and MS metabolomics analysis of DOM from three lakes in an alpine watershed; and the transformation of 13C labeled glucose track with NMR during a rewetting experiment from Colorado grassland soils. These data will be synthesized to illustrate how the application of advanced analytical techniques provides novel insight into our understanding of organic matter processing in a wide range of ecosystems.
NASA Technical Reports Server (NTRS)
Williams, J. G.; Mikulas, M. M., Jr.
1975-01-01
Structural efficiency studies were made to determine the weight-saving potential of graphite/epoxy composite structures for compression panel applications. Minimum-weight hat-stiffened and open-corrugation configurations were synthesized using a nonlinear mathematical programing technique. Selected configurations were built and tested to study local and Euler buckling characteristics. Test results for 23 panels critical in local buckling and six panels critical in Euler buckling are compared with analytical results obtained using the BUCLASP-2 branched plate buckling program. A weight efficiency comparison is made between composite and aluminum compression panels using metal test data generated by the NACA. Theoretical studies indicate that potential weight savings of up to 50% are possible for composite hat-stiffened panels when compared with similar aluminum designs. Weight savings of 32% to 42% were experimentally achieved. Experience to date suggests that most of the theoretical weight-saving potential is available if design deficiencies are eliminated and strict fabrication control is exercised.
Theory of the electronic structure of substitutional semiconductor alloys: Analytical approaches
Zakharov, A. Yu.
2015-07-15
Methods of predicting the electronic structure of disordered semiconductor alloys involving mainly isoelectronic substitution are reviewed. Special emphasis is placed on analytical methods of studying currently available models of alloys. An approximate equation for the localization threshold of electronic states in the Lifshitz model is considered, and the inaccuracy of this equation is estimated. The contributions of the perturbation potential of an individual impurity and of crystal-lattice distortions in the vicinity of the impurity center are analyzed on the basis of the Faddeev equations. The contributions of intrinsic impurity potentials and volume effects to the formation of the electronic structure of semiconductor alloys are esti- mated. Methods of calculating matrix elements of the perturbation potentials of isoelectronic impurities in alloys with consideration for deformation effects are considered. The procedure of calculating the compositional dependence of the band gap of multicomponent alloys is described. A comparative analysis of various methods for predicting the formation of electronic states bound at individual isoelectronic impurities in semiconductors is conducted. The theory of the energy spectrum of charged impurities in isoelectronic alloys is presented.
The structural properties of a two-Yukawa fluid: Simulation and analytical results.
Broccio, Matteo; Costa, Dino; Liu, Yun; Chen, Sow-Hsin
2006-02-28
Standard Monte Carlo simulations are carried out to assess the accuracy of theoretical predictions for the structural properties of a model fluid interacting through a hard-core two-Yukawa potential composed of a short-range attractive well next to a hard repulsive core, followed by a smooth, long-range repulsive tail. Theoretical calculations are performed in the framework provided by the Ornstein-Zernike equation, solved either analytically with the mean spherical approximation (MSA) or iteratively with the hypernetted-chain (HNC) closure. Our analysis shows that both theories are generally accurate in a thermodynamic region corresponding to a dense vapor phase around the critical point. For a suitable choice of potential parameters, namely, when the attractive well is deep and/or large enough, the static structure factor displays a secondary low-Q peak. In this case HNC predictions closely follow the simulation results, whereas MSA results progressively worsen the more pronounced this low-Q peak is. We discuss the appearance of such a peak, also experimentally observed in colloidal suspensions and protein solutions, in terms of the formation of equilibrium clusters in the homogeneous fluid.
The structural properties of a two-Yukawa fluid: Simulation and analytical results
NASA Astrophysics Data System (ADS)
Broccio, Matteo; Costa, Dino; Liu, Yun; Chen, Sow-Hsin
2006-02-01
Standard Monte Carlo simulations are carried out to assess the accuracy of theoretical predictions for the structural properties of a model fluid interacting through a hard-core two-Yukawa potential composed of a short-range attractive well next to a hard repulsive core, followed by a smooth, long-range repulsive tail. Theoretical calculations are performed in the framework provided by the Ornstein-Zernike equation, solved either analytically with the mean spherical approximation (MSA) or iteratively with the hypernetted-chain (HNC) closure. Our analysis shows that both theories are generally accurate in a thermodynamic region corresponding to a dense vapor phase around the critical point. For a suitable choice of potential parameters, namely, when the attractive well is deep and/or large enough, the static structure factor displays a secondary low-Q peak. In this case HNC predictions closely follow the simulation results, whereas MSA results progressively worsen the more pronounced this low-Q peak is. We discuss the appearance of such a peak, also experimentally observed in colloidal suspensions and protein solutions, in terms of the formation of equilibrium clusters in the homogeneous fluid.
Analytic prediction of baryonic effects from the EFT of large scale structures
NASA Astrophysics Data System (ADS)
Lewandowski, Matthew; Perko, Ashley; Senatore, Leonardo
2015-05-01
The large scale structures of the universe will likely be the next leading source of cosmological information. It is therefore crucial to understand their behavior. The Effective Field Theory of Large Scale Structures provides a consistent way to perturbatively predict the clustering of dark matter at large distances. The fact that baryons move distances comparable to dark matter allows us to infer that baryons at large distances can be described in a similar formalism: the backreaction of short-distance non-linearities and of star-formation physics at long distances can be encapsulated in an effective stress tensor, characterized by a few parameters. The functional form of baryonic effects can therefore be predicted. In the power spectrum the leading contribution goes as propto k2 P(k), with P(k) being the linear power spectrum and with the numerical prefactor depending on the details of the star-formation physics. We also perform the resummation of the contribution of the long-wavelength displacements, allowing us to consistently predict the effect of the relative motion of baryons and dark matter. We compare our predictions with simulations that contain several implementations of baryonic physics, finding percent agreement up to relatively high wavenumbers such as k simeq 0.3 hMpc-1 or k simeq 0.6 hMpc-1, depending on the order of the calculation. Our results open a novel way to understand baryonic effects analytically, as well as to interface with simulations.
NASA Astrophysics Data System (ADS)
Anton, J. M.; Grau, J. B.; Tarquis, A. M.; Andina, D.; Sanchez, M. E.
2012-04-01
The authors have been involved in Model Codes for Construction prior to Eurocodes now Euronorms, and in a Drainage Instruction for Roads for Spain that adopted a prediction model from BPR (Bureau of Public Roads) of USA to take account of evident regional differences in Iberian Peninsula and Spanish Isles, and in some related studies. They used Extreme Value Type I (Gumbell law) models, with independent actions in superposition; this law was also adopted then to obtain maps of extreme rains by CEDEX. These methods could be extrapolated somehow with other extreme values distributions, but the first step was useful to set valid superposition schemas for actions in norms. As real case, in East of Spain rain comes usually extensively from normal weather perturbations, but in other cases from "cold drop" local high rains of about 400mm in a day occur, causing inundations and in cases local disasters. The city of Valencia in East of Spain was inundated at 1,5m high from a cold drop in 1957, and the river Turia formerly through that city was just later diverted some kilometers to South in a wider canal. With Gumbell law the expected intensity grows with time for occurrence, indicating a value for each given "return period", but the increasing speed grows with the "annual dispersion" of the Gumbell law, and some rare dangerous events may become really very possible in periods of many years. That can be proved with relatively simple models, e.g. with Extreme Law type I, and they could be made more precise or discussed. Such effects were used for superposition of actions on a structure for Model Codes, and may be combined with hydraulic effects, e.g. for bridges on rivers. These different Gumbell laws, or other extreme laws, with different dispersion may occur for marine actions of waves, earthquakes, tsunamis, and maybe for human perturbations, that could include industrial catastrophes, or civilization wars if considering historical periods.
Quantum jumps, superpositions, and the continuous evolution of quantum states
NASA Astrophysics Data System (ADS)
Dick, Rainer
2017-02-01
The apparent dichotomy between quantum jumps on the one hand, and continuous time evolution according to wave equations on the other hand, provided a challenge to Bohr's proposal of quantum jumps in atoms. Furthermore, Schrödinger's time-dependent equation also seemed to require a modification of the explanation for the origin of line spectra due to the apparent possibility of superpositions of energy eigenstates for different energy levels. Indeed, Schrödinger himself proposed a quantum beat mechanism for the generation of discrete line spectra from superpositions of eigenstates with different energies. However, these issues between old quantum theory and Schrödinger's wave mechanics were correctly resolved only after the development and full implementation of photon quantization. The second quantized scattering matrix formalism reconciles quantum jumps with continuous time evolution through the identification of quantum jumps with transitions between different sectors of Fock space. The continuous evolution of quantum states is then recognized as a sum over continually evolving jump amplitudes between different sectors in Fock space. In today's terminology, this suggests that linear combinations of scattering matrix elements are epistemic sums over ontic states. Insights from the resolution of the dichotomy between quantum jumps and continuous time evolution therefore hold important lessons for modern research both on interpretations of quantum mechanics and on the foundations of quantum computing. They demonstrate that discussions of interpretations of quantum theory necessarily need to take into account field quantization. They also demonstrate the limitations of the role of wave equations in quantum theory, and caution us that superpositions of quantum states for the formation of qubits may be more limited than usually expected.
Improved scatter correction using adaptive scatter kernel superposition
NASA Astrophysics Data System (ADS)
Sun, M.; Star-Lack, J. M.
2010-11-01
Accurate scatter correction is required to produce high-quality reconstructions of x-ray cone-beam computed tomography (CBCT) scans. This paper describes new scatter kernel superposition (SKS) algorithms for deconvolving scatter from projection data. The algorithms are designed to improve upon the conventional approach whose accuracy is limited by the use of symmetric kernels that characterize the scatter properties of uniform slabs. To model scatter transport in more realistic objects, nonstationary kernels, whose shapes adapt to local thickness variations in the projection data, are proposed. Two methods are introduced: (1) adaptive scatter kernel superposition (ASKS) requiring spatial domain convolutions and (2) fast adaptive scatter kernel superposition (fASKS) where, through a linearity approximation, convolution is efficiently performed in Fourier space. The conventional SKS algorithm, ASKS, and fASKS, were tested with Monte Carlo simulations and with phantom data acquired on a table-top CBCT system matching the Varian On-Board Imager (OBI). All three models accounted for scatter point-spread broadening due to object thickening, object edge effects, detector scatter properties and an anti-scatter grid. Hounsfield unit (HU) errors in reconstructions of a large pelvis phantom with a measured maximum scatter-to-primary ratio over 200% were reduced from -90 ± 58 HU (mean ± standard deviation) with no scatter correction to 53 ± 82 HU with SKS, to 19 ± 25 HU with fASKS and to 13 ± 21 HU with ASKS. HU accuracies and measured contrast were similarly improved in reconstructions of a body-sized elliptical Catphan phantom. The results show that the adaptive SKS methods offer significant advantages over the conventional scatter deconvolution technique.
Analysis of structural dynamic data from Skylab. Volume 2: Skylab analytical and test modal data
NASA Technical Reports Server (NTRS)
Demchak, L.; Harcrow, H.
1976-01-01
A compendium is presented of orbital configuration test modal data, analytical test modal data, analytical test correlation modal data and analytical flight configuration 1.2 modal data. Section A presents tables showing the generalized mass contributions for each of the thirty test modes. Section B presents the two dimensional mode shape plots for the thirty test modes. Tables of GMC's for the test correlated analytical modes are presented in Section C. These analytical modes were generated from a model that was adjusted to match test results by use of the methodology discussed in Sections 2.3 and 5.4 of Volume I of this report. Section D presents the two dimensional mode shape plots for the analytical modes. Sections E and F contain the uncoupled and coupled modes of the orbital flight configuration 1.2 at three development phases of the model.
Labelled Unit Superposition Calculi for Instantiation-Based Reasoning
NASA Astrophysics Data System (ADS)
Korovin, Konstantin; Sticksel, Christoph
The Inst-Gen-Eq method is an instantiation-based calculus which is complete for first-order clause logic modulo equality. Its distinctive feature is that it combines first-order reasoning with efficient ground satisfiability checking which is delegated in a modular way to any state-of-the-art ground SMT solver. The first-order reasoning modulo equality employs a superposition-style calculus which generates the instances needed by the ground solver to refine a model of a ground abstraction or to witness unsatisfiability.
Scaling of macroscopic superpositions close to a quantum phase transition
NASA Astrophysics Data System (ADS)
Abad, Tahereh; Karimipour, Vahid
2016-05-01
It is well known that in a quantum phase transition (QPT), entanglement remains short ranged [Osterloh et al., Nature (London) 416, 608 (2005), 10.1038/416608a]. We ask if there is a quantum property entailing the whole system which diverges near this point. Using the recently proposed measures of quantum macroscopicity, we show that near a quantum critical point, it is the effective size of macroscopic superposition between the two symmetry breaking states which grows to the scale of system size, and its derivative with respect to the coupling shows both singular behavior and scaling properties.
Concentration-temperature superposition of helix folding rates in gelatin.
Gornall, J L; Terentjev, E M
2007-07-13
Using optical rotation as the primary technique, we have characterized the kinetics of helix renaturation in water solutions of gelatin. By covering a wide range of solution concentrations we identify a universal exponential dependence of folding rate on concentration and quench temperature. We demonstrate a new concentration-temperature superposition of data at all temperatures and concentrations, and build the corresponding master curve. The normalized rate constant is consistent with helix lengthening. Nucleation of the triple helix occurs rapidly and contributes less to the helical onset than previously thought.
The problem of effect size heterogeneity in meta-analytic structural equation modeling.
Yu, Jia Joya; Downes, Patrick E; Carter, Kameron M; O'Boyle, Ernest H
2016-10-01
Scholars increasingly recognize the potential of meta-analytic structural equation modeling (MASEM) as a way to build and test theory (Bergh et al., 2016). Yet, 1 of the greatest challenges facing MASEM researchers is how to incorporate and model meaningful effect size heterogeneity identified in the bivariate meta-analysis into MASEM. Unfortunately, common MASEM approaches in applied psychology (i.e., Viswesvaran & Ones, 1995) fail to account for effect size heterogeneity. This means that MASEM effect sizes, path estimates, and overall fit values may only generalize to a small segment of the population. In this research, we quantify this problem and introduce a set of techniques that retain both the true score relationships and the variability surrounding those relationships in estimating model parameters and fit indices. We report our findings from simulated data as well as from a reanalysis of published MASEM studies. Results demonstrate that both path estimates and overall model fit indices are less representative of the population than existing MASEM research would suggest. We suggest 2 extension MASEM techniques that can be conducted using online software or in R, to quantify the stability of model estimates across the population and allow researchers to better build and test theory. (PsycINFO Database Record
THE ANALYTICAL STRUCTURE OF THE PRIMARY INTERSTELLAR HELIUM DISTRIBUTION FUNCTION IN THE HELIOSPHERE
Lee, Martin A.; Möbius, Eberhard; Leonard, Trevor W.
2015-10-15
A new analytical model based on the previous work of Lee et al. is presented for the distribution of interstellar helium in the heliosphere. The model is tailored for comparison with the IBEX-Lo observations in order to determine the bulk velocity and temperature of helium in the local interstellar cloud. The model includes solar gravity, spherically symmetric stationary ionization rates, transformation to the Earth/IBEX frame of reference, the IBEX viewing geometry with small spin-axis tilt, and integration of the atom differential intensity over energy and the instrument collimator solid angle. The analysis employs an expansion of the count rate about the peak of the velocity distribution to second order in the magnitudes of several small quantities: the ratio of the helium thermal speed to its bulk speed, the angle between the bulk velocity and the ecliptic, the two angles describing the tilt of the IBEX spin-axis away from Sun-pointing, the collimator angular width, and the angular difference between the observing longitude and the longitude where the projection of the bulk velocity onto the ecliptic is tangential to Earth's orbit. The model reveals the evolving ellipsoidal shape of the helium distribution as it moves along its average hyperbolic orbit. For specified interstellar parameters, the model predicts the latitudinal and longitudinal structure of the helium distribution. The model is in reasonable agreement with IBEX observations and the predictions of the other available models.
NASA Astrophysics Data System (ADS)
Stevens, Adam R. H.; Croton, Darren J.; Mutch, Simon J.
2016-09-01
We present the new semi-analytic model of galaxy evolution, DARK SAGE, a heavily modified version of the publicly available SAGE code. The model is designed for detailed evolution of galactic discs. We evolve discs in a series of annuli with fixed specific angular momentum, which allows us to make predictions for the radial and angular-momentum structure of galaxies. Most physical processes, including all channels of star formation and associated feedback, are performed in these annuli. We present the surface density profiles of our model spiral galaxies, both as a function of radius and specific angular momentum, and find that the discs naturally build a pseudo-bulge-like component. Our main results are focused on predictions relating to the integrated mass-specific angular momentum relation of stellar discs. The model produces a distinct sequence between these properties in remarkable agreement with recent observational literature. We investigate the impact Toomre disc instabilities have on shaping this sequence and find they are crucial for regulating both the mass and spin of discs. Without instabilities, high-mass discs would be systematically deficient in specific angular momentum by a factor of ˜2.5, with increased scatter. Instabilities also appear to drive the direction in which the mass-spin sequence of spiral galaxy discs evolves. With them, we find galaxies of fixed mass have higher specific angular momentum at later epochs.
NASA Astrophysics Data System (ADS)
Ulriksen, M. D.; Damkilde, L.
2016-02-01
Contrary to global modal parameters such as eigenfrequencies, mode shapes inherently provide structural information on a local level. Therefore, this particular modal parameter and its derivatives are utilized extensively for damage identification. Typically, more or less advanced mathematical methods are employed to identify damage-induced discontinuities in the spatial mode shape signals, hereby, potentially, facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement noise. In the present paper, a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement noise is proposed. The method is based on signal processing of a spatial mode shape by means of continuous wavelet transformation (CWT) and subsequent application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact damage-induced, outlier analysis is conducted by applying the Mahalanobis metric to major principal scores of the sensor-located bands of the signal-processed mode shape. The method is tested analytically and benchmarked with other mode shape-based damage localization approaches on the basis of a free-vibrating beam and validated experimentally in the context of a residential-sized wind turbine blade subjected to an impulse load.
X-ray optics simulation using Gaussian superposition technique.
Idir, Mourad; Cywiak, Moisés; Morales, Arquímedes; Modi, Mohammed H
2011-09-26
We present an efficient method to perform x-ray optics simulation with high or partially coherent x-ray sources using Gaussian superposition technique. In a previous paper, we have demonstrated that full characterization of optical systems, diffractive and geometric, is possible by using the Fresnel Gaussian Shape Invariant (FGSI) previously reported in the literature. The complex amplitude distribution in the object plane is represented by a linear superposition of complex Gaussians wavelets and then propagated through the optical system by means of the referred Gaussian invariant. This allows ray tracing through the optical system and at the same time allows calculating with high precision the complex wave-amplitude distribution at any plane of observation. This technique can be applied in a wide spectral range where the Fresnel diffraction integral applies including visible, x-rays, acoustic waves, etc. We describe the technique and include some computer simulations as illustrative examples for x-ray optical component. We show also that this method can be used to study partial or total coherence illumination problem.
Experiments testing macroscopic quantum superpositions must be slow
NASA Astrophysics Data System (ADS)
Mari, Andrea; de Palma, Giacomo; Giovannetti, Vittorio
2016-03-01
We consider a thought experiment where the preparation of a macroscopically massive or charged particle in a quantum superposition and the associated dynamics of a distant test particle apparently allow for superluminal communication. We give a solution to the paradox which is based on the following fundamental principle: any local experiment, discriminating a coherent superposition from an incoherent statistical mixture, necessarily requires a minimum time proportional to the mass (or charge) of the system. For a charged particle, we consider two examples of such experiments, and show that they are both consistent with the previous limitation. In the first, the measurement requires to accelerate the charge, that can entangle with the emitted photons. In the second, the limitation can be ascribed to the quantum vacuum fluctuations of the electromagnetic field. On the other hand, when applied to massive particles our result provides an indirect evidence for the existence of gravitational vacuum fluctuations and for the possibility of entangling a particle with quantum gravitational radiation.
Modeling scattering from azimuthally symmetric bathymetric features using wavefield superposition.
Fawcett, John A
2007-12-01
In this paper, an approach for modeling the scattering from azimuthally symmetric bathymetric features is described. These features are useful models for small mounds and indentations on the seafloor at high frequencies and seamounts, shoals, and basins at low frequencies. A bathymetric feature can be considered as a compact closed region, with the same sound speed and density as one of the surrounding media. Using this approach, a number of numerical methods appropriate for a partially buried target or facet problem can be applied. This paper considers the use of wavefield superposition and because of the azimuthal symmetry, the three-dimensional solution to the scattering problem can be expressed as a Fourier sum of solutions to a set of two-dimensional scattering problems. In the case where the surrounding two half spaces have only a density contrast, a semianalytic coupled mode solution is derived. This provides a benchmark solution to scattering from a class of penetrable hemispherical bosses or indentations. The details and problems of the numerical implementation of the wavefield superposition method are described. Example computations using the method for a simple scattering feature on a seabed are presented for a wide band of frequencies.
Free Nano-Object Ramsey Interferometry for Large Quantum Superpositions
NASA Astrophysics Data System (ADS)
Wan, C.; Scala, M.; Morley, G. W.; Rahman, ATM. A.; Ulbricht, H.; Bateman, J.; Barker, P. F.; Bose, S.; Kim, M. S.
2016-09-01
We propose an interferometric scheme based on an untrapped nano-object subjected to gravity. The motion of the center of mass (c.m.) of the free object is coupled to its internal spin system magnetically, and a free flight scheme is developed based on coherent spin control. The wave packet of the test object, under a spin-dependent force, may then be delocalized to a macroscopic scale. A gravity induced dynamical phase (accrued solely on the spin state, and measured through a Ramsey scheme) is used to reveal the above spatially delocalized superposition of the spin-nano-object composite system that arises during our scheme. We find a remarkable immunity to the motional noise in the c.m. (initially in a thermal state with moderate cooling), and also a dynamical decoupling nature of the scheme itself. Together they secure a high visibility of the resulting Ramsey fringes. The mass independence of our scheme makes it viable for a nano-object selected from an ensemble with a high mass variability. Given these advantages, a quantum superposition with a 100 nm spatial separation for a massive object of 1 09 amu is achievable experimentally, providing a route to test postulated modifications of quantum theory such as continuous spontaneous localization.
Runs in superpositions of renewal processes with applications to discrimination
NASA Astrophysics Data System (ADS)
Alsmeyer, Gerold; Irle, Albrecht
2006-02-01
Wald and Wolfowitz [Ann. Math. Statist. 11 (1940) 147-162] introduced the run test for testing whether two samples of i.i.d. random variables follow the same distribution. Here a run means a consecutive subsequence of maximal length from only one of the two samples. In this paper we contribute to the problem of runs and resulting test procedures for the superposition of independent renewal processes which may be interpreted as arrival processes of customers from two different input channels at the same service station. To be more precise, let (Sn)n[greater-or-equal, slanted]1 and (Tn)n[greater-or-equal, slanted]1 be the arrival processes for channel 1 and channel 2, respectively, and (Wn)n[greater-or-equal, slanted]1 their be superposition with counting process . Let further be the number of runs in W1,...,Wn and the number of runs observed up to time t. We study the asymptotic behavior of and Rt, first for the case where (Sn)n[greater-or-equal, slanted]1 and (Tn)n[greater-or-equal, slanted]1 have exponentially distributed increments with parameters [lambda]1 and [lambda]2, and then for the more difficult situation when these increments have an absolutely continuous distribution. These results are used to design asymptotic level [alpha] tests for testing [lambda]1=[lambda]2 against [lambda]1[not equal to][lambda]2 in the first case, and for testing for equal scale parameters in the second.
Experiments testing macroscopic quantum superpositions must be slow
Mari, Andrea; De Palma, Giacomo; Giovannetti, Vittorio
2016-01-01
We consider a thought experiment where the preparation of a macroscopically massive or charged particle in a quantum superposition and the associated dynamics of a distant test particle apparently allow for superluminal communication. We give a solution to the paradox which is based on the following fundamental principle: any local experiment, discriminating a coherent superposition from an incoherent statistical mixture, necessarily requires a minimum time proportional to the mass (or charge) of the system. For a charged particle, we consider two examples of such experiments, and show that they are both consistent with the previous limitation. In the first, the measurement requires to accelerate the charge, that can entangle with the emitted photons. In the second, the limitation can be ascribed to the quantum vacuum fluctuations of the electromagnetic field. On the other hand, when applied to massive particles our result provides an indirect evidence for the existence of gravitational vacuum fluctuations and for the possibility of entangling a particle with quantum gravitational radiation. PMID:26959656
X-ray optics simulation using Gaussian superposition technique
Idir, M.; Cywiak, M.; Morales, A. and Modi, M.H.
2011-09-15
We present an efficient method to perform x-ray optics simulation with high or partially coherent x-ray sources using Gaussian superposition technique. In a previous paper, we have demonstrated that full characterization of optical systems, diffractive and geometric, is possible by using the Fresnel Gaussian Shape Invariant (FGSI) previously reported in the literature. The complex amplitude distribution in the object plane is represented by a linear superposition of complex Gaussians wavelets and then propagated through the optical system by means of the referred Gaussian invariant. This allows ray tracing through the optical system and at the same time allows calculating with high precision the complex wave-amplitude distribution at any plane of observation. This technique can be applied in a wide spectral range where the Fresnel diffraction integral applies including visible, x-rays, acoustic waves, etc. We describe the technique and include some computer simulations as illustrative examples for x-ray optical component. We show also that this method can be used to study partial or total coherence illumination problem.
Evolution of superpositions of quantum states through a level crossing
Torosov, B. T.; Vitanov, N. V.
2011-12-15
The Landau-Zener-Stueckelberg-Majorana (LZSM) model is widely used for estimating transition probabilities in the presence of crossing energy levels in quantum physics. This model, however, makes the unphysical assumption of an infinitely long constant interaction, which introduces a divergent phase in the propagator. This divergence remains hidden when estimating output probabilities for a single input state insofar as the divergent phase cancels out. In this paper we show that, because of this divergent phase, the LZSM model is inadequate to describe the evolution of pure or mixed superposition states across a level crossing. The LZSM model can be used only if the system is initially in a single state or in a completely mixed superposition state. To this end, we show that the more realistic Demkov-Kunike model, which assumes a hyperbolic-tangent level crossing and a hyperbolic-secant interaction envelope, is free of divergences and is a much more adequate tool for describing the evolution through a level crossing for an arbitrary input state. For multiple crossing energies which are reducible to one or more effective two-state systems (e.g., by the Majorana and Morris-Shore decompositions), similar conclusions apply: the LZSM model does not produce definite values of the populations and the coherences, and one should use the Demkov-Kunike model instead.
Experiments testing macroscopic quantum superpositions must be slow.
Mari, Andrea; De Palma, Giacomo; Giovannetti, Vittorio
2016-03-09
We consider a thought experiment where the preparation of a macroscopically massive or charged particle in a quantum superposition and the associated dynamics of a distant test particle apparently allow for superluminal communication. We give a solution to the paradox which is based on the following fundamental principle: any local experiment, discriminating a coherent superposition from an incoherent statistical mixture, necessarily requires a minimum time proportional to the mass (or charge) of the system. For a charged particle, we consider two examples of such experiments, and show that they are both consistent with the previous limitation. In the first, the measurement requires to accelerate the charge, that can entangle with the emitted photons. In the second, the limitation can be ascribed to the quantum vacuum fluctuations of the electromagnetic field. On the other hand, when applied to massive particles our result provides an indirect evidence for the existence of gravitational vacuum fluctuations and for the possibility of entangling a particle with quantum gravitational radiation.
Free Nano-Object Ramsey Interferometry for Large Quantum Superpositions.
Wan, C; Scala, M; Morley, G W; Rahman, Atm A; Ulbricht, H; Bateman, J; Barker, P F; Bose, S; Kim, M S
2016-09-30
We propose an interferometric scheme based on an untrapped nano-object subjected to gravity. The motion of the center of mass (c.m.) of the free object is coupled to its internal spin system magnetically, and a free flight scheme is developed based on coherent spin control. The wave packet of the test object, under a spin-dependent force, may then be delocalized to a macroscopic scale. A gravity induced dynamical phase (accrued solely on the spin state, and measured through a Ramsey scheme) is used to reveal the above spatially delocalized superposition of the spin-nano-object composite system that arises during our scheme. We find a remarkable immunity to the motional noise in the c.m. (initially in a thermal state with moderate cooling), and also a dynamical decoupling nature of the scheme itself. Together they secure a high visibility of the resulting Ramsey fringes. The mass independence of our scheme makes it viable for a nano-object selected from an ensemble with a high mass variability. Given these advantages, a quantum superposition with a 100 nm spatial separation for a massive object of 10^{9} amu is achievable experimentally, providing a route to test postulated modifications of quantum theory such as continuous spontaneous localization.
The structure of common emotion regulation strategies: A meta-analytic examination.
Naragon-Gainey, Kristin; McMahon, Tierney P; Chacko, Thomas P
2017-04-01
Emotion regulation has been examined extensively with regard to important outcomes, including psychological and physical health. However, the literature includes many different emotion regulation strategies but little examination of how they relate to one another, making it difficult to interpret and synthesize findings. The goal of this meta-analysis was to examine the underlying structure of common emotion regulation strategies (i.e., acceptance, behavioral avoidance, distraction, experiential avoidance, expressive suppression, mindfulness, problem solving, reappraisal, rumination, worry), and to evaluate this structure in light of theoretical models of emotion regulation. We also examined how distress tolerance-an important emotion regulation ability -relates to strategy use. We conducted meta-analyses estimating the correlations between emotion regulation strategies (based on 331 samples and 670 effect sizes), as well as between distress tolerance and strategies. The resulting meta-analytic correlation matrix was submitted to confirmatory and exploratory factor analyses. None of the confirmatory models, based on prior theory, was an acceptable fit to the data. Exploratory factor analysis suggested that 3 underlying factors best characterized these data. Two factors-labeled Disengagement and Aversive Cognitive Perseveration-emerged as strongly correlated but distinct factors, with the latter consisting of putatively maladaptive strategies. The third factor, Adaptive Engagement, was a less unified factor and weakly related to the other 2 factors. Distress tolerance was most closely associated with low levels of repetitive negative thought and experiential avoidance, and high levels of acceptance and mindfulness. We discuss the theoretical implications of these findings and applications to emotion regulation assessment. (PsycINFO Database Record
NASA Astrophysics Data System (ADS)
Suhir, Ephraim
2015-03-01
An updated version of the paper with revised references has been published The review part of the paper addresses analytical (mathematical) modeling in structural analysis in fiber optics engineering, mostly fiber optics interconnects, and deals with optical fibers subjected to thermal and/or mechanical loading (stresses) in bending, tension, compression, or to the combinations of such loadings. Attributes and significance of predictive modeling are indicated and discussed. The review is based mostly on the author's research conducted at Bell Laboratories, Physical Sciences and Engineering Research Division, Murray Hill, NJ, USA, during his tenure with this company, and, to a lesser extent, on his recent work in the field. The addressed structures include, but are not limited to, optical fibers of finite length: bare fibers; jacketed and dual-coated fibers; fibers experiencing thermal loading; fibers soldered into ferrules or adhesively bonded into capillaries; as well as the roles of geometric and material non-linearity; dynamic response to shocks and vibrations; and possible applications of nano-materials in new generations of coating and cladding systems. The extension part is concerned with a novel, fruitful and challenging directionprobabilistic design for reliability (PDfR) of opto-electronic and photonic products, including optical fibers and interconnects. The rationale behind the PDfR concept is that there is no such thing as zero probability of failure, that the difference between a highly reliable product and an insufficiently reliable product is "merely" in the level of the never zero probability of its failure and that when the operational performance of the product is imperative, the ability to predict, quantify, assure and, if possible and appropriate, even specify its reliability is highly desirable. Accordingly, the objective of the PDfR effort is to quantify the likelihood of an operational failure of a material, device or a system, including the
Analytic prediction of baryonic effects from the EFT of large scale structures
Lewandowski, Matthew; Perko, Ashley; Senatore, Leonardo E-mail: perko@stanford.edu
2015-05-01
The large scale structures of the universe will likely be the next leading source of cosmological information. It is therefore crucial to understand their behavior. The Effective Field Theory of Large Scale Structures provides a consistent way to perturbatively predict the clustering of dark matter at large distances. The fact that baryons move distances comparable to dark matter allows us to infer that baryons at large distances can be described in a similar formalism: the backreaction of short-distance non-linearities and of star-formation physics at long distances can be encapsulated in an effective stress tensor, characterized by a few parameters. The functional form of baryonic effects can therefore be predicted. In the power spectrum the leading contribution goes as ∝ k{sup 2} P(k), with P(k) being the linear power spectrum and with the numerical prefactor depending on the details of the star-formation physics. We also perform the resummation of the contribution of the long-wavelength displacements, allowing us to consistently predict the effect of the relative motion of baryons and dark matter. We compare our predictions with simulations that contain several implementations of baryonic physics, finding percent agreement up to relatively high wavenumbers such as k ≅ 0.3 hMpc{sup −1} or k ≅ 0.6 hMpc{sup −1}, depending on the order of the calculation. Our results open a novel way to understand baryonic effects analytically, as well as to interface with simulations.
NASA Astrophysics Data System (ADS)
Mitri, F. G.
2016-08-01
In this work, counterintuitive effects such as the generation of an axial (i.e., long the direction of wave motion) zero-energy flux density (i.e., axial Poynting singularity) and reverse (i.e., negative) propagation of nonparaxial quasi-Gaussian electromagnetic (EM) beams are examined. Generalized analytical expressions for the EM field's components of a coherent superposition of two high-order quasi-Gaussian vortex beams of opposite handedness and different amplitudes are derived based on the complex-source-point method, stemming from Maxwell's vector equations and the Lorenz gauge condition. The general solutions exhibiting unusual effects satisfy the Helmholtz and Maxwell's equations. The EM beam components are characterized by nonzero integer degree and order (n ,m ) , respectively, an arbitrary waist w0, a diffraction convergence length known as the Rayleigh range zR, and a weighting (real) factor 0 ≤α ≤1 that describes the transition of the beam from a purely vortex (α =0 ) to a nonvortex (α =1 ) type. An attractive feature for this superposition is the description of strongly focused (or strongly divergent) wave fields. Computations of the EM power density as well as the linear and angular momentum density fluxes illustrate the analysis with particular emphasis on the polarization states of the vector potentials forming the beams and the weight of the coherent beam superposition causing the transition from the vortex to the nonvortex type. Should some conditions determined by the polarization state of the vector potentials and the beam parameters be met, an axial zero-energy flux density is predicted in addition to a negative retrograde propagation effect. Moreover, rotation reversal of the angular momentum flux density with respect to the beam handedness is anticipated, suggesting the possible generation of negative (left-handed) torques. The results are particularly useful in applications involving the design of strongly focused optical laser
ERIC Educational Resources Information Center
Schniering, Carolyn A.; Rapee, Ronald M.
2004-01-01
The aim of this study was to examine the nature and organization of a range of negative self-statements in children and adolescents, using a structural equations/confirmatory factor-analytic approach. A community sample of 978 children aged 7-16 years completed a questionnaire about the frequency with which they experienced a broad range of…
ERIC Educational Resources Information Center
Goggins, S. P.; Galyen, K. D.; Petakovic, E.; Laffey, J. M.
2016-01-01
This exploratory study focuses on the design and evaluation of teaching analytics that relate social learning structure with performance measures in a massive open online course (MOOC) prototype environment. Using reflexive analysis of online learning trace data and qualitative performance measures we present an exploratory empirical study that:…
ERIC Educational Resources Information Center
Bernstein, Amit; Zvolensky, Michael J.; Stewart, Sherry; Comeau, Nancy
2007-01-01
This study represents an effort to better understand the latent structure of anxiety sensitivity (AS), a well-established affect-sensitivity individual difference factor, among youth by employing taxometric and factor analytic approaches in an integrative manner. Taxometric analyses indicated that AS, as indexed by the Child Anxiety Sensitivity…
NASA Technical Reports Server (NTRS)
Bryson, L. L.; Mccarty, J. E.
1973-01-01
Analytical and experimental investigations, performed to establish the feasibility of reinforcing metal aircraft structures with advanced filamentary composites, are reported. Aluminum-boron-epoxy and titanium-boron-epoxy were used in the design and manufacture of three major structural components. The components were representative of subsonic aircraft fuselage and window belt panels and supersonic aircraft compression panels. Both unidirectional and multidirectional reinforcement concepts were employed. Blade penetration, axial compression, and inplane shear tests were conducted. Composite reinforced structural components designed to realistic airframe structural criteria demonstrated the potential for significant weight savings while maintaining strength, stability, and damage containment properties of all metal components designed to meet the same criteria.
Multi-level manual and autonomous control superposition for intelligent telerobot
NASA Technical Reports Server (NTRS)
Hirai, Shigeoki; Sato, T.
1989-01-01
Space telerobots are recognized to require cooperation with human operators in various ways. Multi-level manual and autonomous control superposition in telerobot task execution is described. The object model, the structured master-slave manipulation system, and the motion understanding system are proposed to realize the concept. The object model offers interfaces for task level and object level human intervention. The structured master-slave manipulation system offers interfaces for motion level human intervention. The motion understanding system maintains the consistency of the knowledge through all the levels which supports the robot autonomy while accepting the human intervention. The superposing execution of the teleoperational task at multi-levels realizes intuitive and robust task execution for wide variety of objects and in changeful environment. The performance of several examples of operating chemical apparatuses is shown.
NASA Astrophysics Data System (ADS)
Weigl, Bernhard H.; Hixson, Greg T.; Kenny, Margaret; Zebert, Diane; Dwinnell, Silver; Buj, Todd; Yager, Paul
1997-05-01
Based on the recently introduced T-Sensor method, we demonstrate the fluorescence-determination of various analytes directly in whole blood and in serum. The method relies on microfluidic flow in silicon structures, diffusion-based separation, and analyte determination using fluorescent and absorption indicator dyes. Due to extremely small inertial forces in such structures, practically all flow in microstructures is laminar. This allows the movement of different layers of fluid and particles next to each other in a channel without mixing other than by diffusion. A sample solution (e.g., blood), and a receptor solution containing the indicator dye are introduced in a common channel, and flow laminarly next to each other until they exit the structure. Small ions such as H+, and Na+ diffuse rapidly across the channel, whereas larger molecules diffuse more slowly. Larger particles such as blood cells and polymer beads show no significant diffusion within the time the two flow streams are in contact. The fluorescence emission of indicator dyes is a function of the concentration of the analyte molecules and the dye concentration in the interaction zone between the two streams. This device allows continuous monitoring of the concentration of analytes in whole blood without the use of membranes or prior removal of blood cells. This principle is illustrated by the determination of human albumin, total calcium, and pH in whole blood and serum.
The EFT of Large Scale Structures at all redshifts: analytical predictions for lensing
NASA Astrophysics Data System (ADS)
Foreman, Simon; Senatore, Leonardo
2016-04-01
We study the prediction of the Effective Field Theory of Large Scale Structures (EFTofLSS) for the matter power spectrum at different redshifts. In previous work, we found that the two-loop prediction can match the nonlinear power spectrum measured from N-body simulations at redshift zero within approximately 2% up to k~ 0.6 h Mpc-1 after fixing a single free parameter, the so-called "speed of sound". We determine the time evolution of this parameter by matching the EFTofLSS prediction to simulation output at different redshifts, and find that it is well-described by a fitting function that only includes one additional parameter. After the two free parameters are fixed, the prediction agrees with nonlinear data within approximately 2% up to at least k~ 1 h Mpc-1 at z>= 1, and also within approximately 5% up to k~ 1.2 h Mpc-1 at z=1 and k~ 2.3 h Mpc-1 at z=3, a major improvement with respect to other perturbative techniques. We also develop an accurate way to estimate where the EFTofLSS predictions at different loop orders should fail, based on the sizes of the next-order terms that are neglected, and find agreement with the actual comparisons to data. Finally, we use our matter power spectrum results to perform analytical calculations of lensing potential power spectra corresponding to both CMB and galaxy lensing. This opens the door to future direct applications of the EFTofLSS to observations of gravitational clustering on cosmic scales.
Student ability to distinguish between superposition states and mixed states in quantum mechanics
NASA Astrophysics Data System (ADS)
Passante, Gina; Emigh, Paul J.; Shaffer, Peter S.
2015-12-01
Superposition gives rise to the probabilistic nature of quantum mechanics and is therefore one of the concepts at the heart of quantum mechanics. Although we have found that many students can successfully use the idea of superposition to calculate the probabilities of different measurement outcomes, they are often unable to identify the experimental implications of a superposition state. In particular, they fail to recognize how a superposition state and a mixed state (sometimes called a "lack of knowledge" state) can produce different experimental results. We present data that suggest that superposition in quantum mechanics is a difficult concept for students enrolled in sophomore-, junior-, and graduate-level quantum mechanics courses. We illustrate how an interactive lecture tutorial can improve student understanding of quantum mechanical superposition. A longitudinal study suggests that the impact persists after an additional quarter of quantum mechanics instruction that does not specifically address these ideas.
The origin of non-classical effects in a one-dimensional superposition of coherent states
NASA Technical Reports Server (NTRS)
Buzek, V.; Knight, P. L.; Barranco, A. Vidiella
1992-01-01
We investigate the nature of the quantum fluctuations in a light field created by the superposition of coherent fields. We give a physical explanation (in terms of Wigner functions and phase-space interference) why the 1-D superposition of coherent states in the direction of the x-quadrature leads to the squeezing of fluctuations in the y-direction, and show that such a superposition can generate the squeezed vacuum and squeezed coherent states.
Entanglement and Decoherence in Two-Dimensional Coherent State Superpositions
NASA Astrophysics Data System (ADS)
Maleki, Y.
2017-03-01
A detailed investigation of entanglement in the generalized two-dimensional nonorthogonal states, which are expressed in the framework of superposed coherent states, is presented. In addition to quantifying entanglement of the generalized two-dimensional coherent states superposition, necessary and sufficient conditions for maximality of entanglement of these states are found. We show that a large class of maximally entangled coherent states can be constructed, and hence, some new maximally entangled coherent states are explicitly manipulated. The investigation is extended to the mixed system states and entanglement properties of such mixed states are investigated. It is shown that in some cases maximally entangled mixed states can be detected. Furthermore, the effect of decoherence, due to both cavity losses and noisy channel process, on such entangled states are studied and its features are discussed.
slate: A method for the superposition of flexible ligands
NASA Astrophysics Data System (ADS)
Mills, J. E. J.; de Esch, I. J. P.; Perkins, T. D. J.; Dean, P. M.
2001-01-01
A novel program for the superposition of flexible molecules, slate, is presented. It uses simulated annealing to minimise the difference between the distance matrices calculated from the hydrogen-bonding and aromatic-ring properties of two ligands. A method for generating a molecular stack using multiple pairwise matches is illustrated. These stacks are used by the program doh to predict the relative positions of receptor atoms that could form hydrogen bonds to two or more ligands in the dataset. The methodology has been applied to ligands binding to dihydrofolate reductase, thermolysin, H3 histamine receptors, α2 adrenoceptors and 5-HT1D receptors. When there are sufficient numbers and diversity of molecules in the dataset, the prediction of receptor-atom positions is applicable to compound design.
Sensing Super-Position: Human Sensing Beyond the Visual Spectrum
NASA Technical Reports Server (NTRS)
Maluf, David A.; Schipper, John F.
2007-01-01
The coming decade of fast, cheap and miniaturized electronics and sensory devices opens new pathways for the development of sophisticated equipment to overcome limitations of the human senses. This paper addresses the technical feasibility of augmenting human vision through Sensing Super-position by mixing natural Human sensing. The current implementation of the device translates visual and other passive or active sensory instruments into sounds, which become relevant when the visual resolution is insufficient for very difficult and particular sensing tasks. A successful Sensing Super-position meets many human and pilot vehicle system requirements. The system can be further developed into cheap, portable, and low power taking into account the limited capabilities of the human user as well as the typical characteristics of his dynamic environment. The system operates in real time, giving the desired information for the particular augmented sensing tasks. The Sensing Super-position device increases the image resolution perception and is obtained via an auditory representation as well as the visual representation. Auditory mapping is performed to distribute an image in time. The three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. This paper details the approach of developing Sensing Super-position systems as a way to augment the human vision system by exploiting the capabilities of Lie human hearing system as an additional neural input. The human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns. The known capabilities of the human hearing system to learn and understand complicated auditory patterns provided the basic motivation for developing an image-to-sound mapping system. The
Subfemtosecond steering of hydrocarbon deprotonation through superposition of vibrational modes.
Alnaser, A S; Kübel, M; Siemering, R; Bergues, B; Kling, Nora G; Betsch, K J; Deng, Y; Schmidt, J; Alahmed, Z A; Azzeer, A M; Ullrich, J; Ben-Itzhak, I; Moshammer, R; Kleineberg, U; Krausz, F; de Vivie-Riedle, R; Kling, M F
2014-05-08
Subfemtosecond control of the breaking and making of chemical bonds in polyatomic molecules is poised to open new pathways for the laser-driven synthesis of chemical products. The break-up of the C-H bond in hydrocarbons is an ubiquitous process during laser-induced dissociation. While the yield of the deprotonation of hydrocarbons has been successfully manipulated in recent studies, full control of the reaction would also require a directional control (that is, which C-H bond is broken). Here, we demonstrate steering of deprotonation from symmetric acetylene molecules on subfemtosecond timescales before the break-up of the molecular dication. On the basis of quantum mechanical calculations, the experimental results are interpreted in terms of a novel subfemtosecond control mechanism involving non-resonant excitation and superposition of vibrational degrees of freedom. This mechanism permits control over the directionality of chemical reactions via vibrational excitation on timescales defined by the subcycle evolution of the laser waveform.
Macroscopicity of quantum superpositions on a one-parameter unitary path in Hilbert space
NASA Astrophysics Data System (ADS)
Volkoff, T. J.; Whaley, K. B.
2014-12-01
We analyze quantum states formed as superpositions of an initial pure product state and its image under local unitary evolution, using two measurement-based measures of superposition size: one based on the optimal quantum binary distinguishability of the branches of the superposition and another based on the ratio of the maximal quantum Fisher information of the superposition to that of its branches, i.e., the relative metrological usefulness of the superposition. A general formula for the effective sizes of these states according to the branch-distinguishability measure is obtained and applied to superposition states of N quantum harmonic oscillators composed of Gaussian branches. Considering optimal distinguishability of pure states on a time-evolution path leads naturally to a notion of distinguishability time that generalizes the well-known orthogonalization times of Mandelstam and Tamm and Margolus and Levitin. We further show that the distinguishability time provides a compact operational expression for the superposition size measure based on the relative quantum Fisher information. By restricting the maximization procedure in the definition of this measure to an appropriate algebra of observables, we show that the superposition size of, e.g., NOON states and hierarchical cat states, can scale linearly with the number of elementary particles comprising the superposition state, implying precision scaling inversely with the total number of photons when these states are employed as probes in quantum parameter estimation of a 1-local Hamiltonian in this algebra.
Robustness of superposition states evolving under the influence of a thermal reservoir
Sales, J. S.; Almeida, N. G. de
2011-06-15
We study the evolution of superposition states under the influence of a reservoir at zero and finite temperatures in cavity quantum electrodynamics aiming to know how their purity is lost over time. The superpositions studied here are composed of coherent states, orthogonal coherent states, squeezed coherent states, and orthogonal squeezed coherent states, which we introduce to generalize the orthogonal coherent states. For comparison, we also show how the robustness of the superpositions studied here differs from that of a qubit given by a superposition of zero- and one-photon states.
DEMONSTRATION OF THE ANALYTIC ELEMENT METHOD FOR WELLHEAD PROTECTION
A new computer program has been developed to determine time-of-travel capture zones in relatively simple geohydrological settings. The WhAEM package contains an analytic element model that uses superposition of (many) closed form analytical solutions to generate a ground-water fl...
NASA Astrophysics Data System (ADS)
Ma, Zhiyong; Kuhn, Markus; Johnson, David C.
2017-03-01
Determining the structure and composition of small volumes is vital to the ability to understand and control nanoscale properties and critical for advancing both fundamental science and applications, such as semiconductor device manufacturing. While metrology of nanoscale materials (nanoparticles, nanocomposites) and nanoscale semiconductor structures is challenging, both basic research and cutting edge technology benefit from new and enhanced analytical techniques. This focus issue contains articles describing approaches to overcome the challenges in obtaining statistically significant atomic-scale quantification of structure and composition in a variety of materials and devices using electron microscopy and atom probe tomography.
NASA Astrophysics Data System (ADS)
Handlos, Zachary J.
Though considerable research attention has been devoted to examination of the Northern Hemispheric polar and subtropical jet streams, relatively little has been directed toward understanding the circumstances that conspire to produce the relatively rare vertical superposition of these usually separate features. This dissertation investigates the structure and evolution of large-scale environments associated with jet superposition events in the northwest Pacific. An objective identification scheme, using NCEP/NCAR Reanalysis 1 data, is employed to identify all jet superpositions in the west Pacific (30-40°N, 135-175°E) for boreal winters (DJF) between 1979/80 - 2009/10. The analysis reveals that environments conducive to west Pacific jet superposition share several large-scale features usually associated with East Asian Winter Monsoon (EAWM) northerly cold surges, including the presence of an enhanced Hadley Cell-like circulation within the jet entrance region. It is further demonstrated that several EAWM indices are statistically significantly correlated with jet superposition frequency in the west Pacific. The life cycle of EAWM cold surges promotes interaction between tropical convection and internal jet dynamics. Low potential vorticity (PV), high theta e tropical boundary layer air, exhausted by anomalous convection in the west Pacific lower latitudes, is advected poleward towards the equatorward side of the jet in upper tropospheric isentropic layers resulting in anomalous anticyclonic wind shear that accelerates the jet. This, along with geostrophic cold air advection in the left jet entrance region that drives the polar tropopause downward through the jet core, promotes the development of the deep, vertical PV wall characteristic of superposed jets. West Pacific jet superpositions preferentially form within an environment favoring the aforementioned characteristics regardless of EAWM seasonal strength. Post-superposition, it is shown that the west Pacific
ERIC Educational Resources Information Center
Baldwin, Janet
The use of confirmatory factor analytic procedures to examine the dimensionality of writing skills as measured by a large-scale direct writing test was illustrated. Internal construct validity evidence about the nature of writing skills measured by the test was provided. Data used were scores assigned by about 100 trained professional raters on a…
Adaptive superposition of finite element meshes in linear and nonlinear dynamic analysis
NASA Astrophysics Data System (ADS)
Yue, Zhihua
2005-11-01
The numerical analysis of transient phenomena in solids, for instance, wave propagation and structural dynamics, is a very important and active area of study in engineering. Despite the current evolutionary state of modern computer hardware, practical analysis of large scale, nonlinear transient problems requires the use of adaptive methods where computational resources are locally allocated according to the interpolation requirements of the solution form. Adaptive analysis of transient problems involves obtaining solutions at many different time steps, each of which requires a sequence of adaptive meshes. Therefore, the execution speed of the adaptive algorithm is of paramount importance. In addition, transient problems require that the solution must be passed from one adaptive mesh to the next adaptive mesh with a bare minimum of solution-transfer error since this form of error compromises the initial conditions used for the next time step. A new adaptive finite element procedure (s-adaptive) is developed in this study for modeling transient phenomena in both linear elastic solids and nonlinear elastic solids caused by progressive damage. The adaptive procedure automatically updates the time step size and the spatial mesh discretization in transient analysis, achieving the accuracy and the efficiency requirements simultaneously. The novel feature of the s-adaptive procedure is the original use of finite element mesh superposition to produce spatial refinement in transient problems. The use of mesh superposition enables the s-adaptive procedure to completely avoid the need for cumbersome multipoint constraint algorithms and mesh generators, which makes the s-adaptive procedure extremely fast. Moreover, the use of mesh superposition enables the s-adaptive procedure to minimize the solution-transfer error. In a series of different solid mechanics problem types including 2-D and 3-D linear elastic quasi-static problems, 2-D material nonlinear quasi-static problems
Student Ability to Distinguish between Superposition States and Mixed States in Quantum Mechanics
ERIC Educational Resources Information Center
Passante, Gina; Emigh, Paul J.; Shaffer, Peter S.
2015-01-01
Superposition gives rise to the probabilistic nature of quantum mechanics and is therefore one of the concepts at the heart of quantum mechanics. Although we have found that many students can successfully use the idea of superposition to calculate the probabilities of different measurement outcomes, they are often unable to identify the…
NASA Astrophysics Data System (ADS)
Ismail Ozkaya, Sait
2014-03-01
An Excel Visual Basic program, SUPERPOSE, is presented to predict the distribution, relative size and strike of tensile and shear fractures on anticlinal structures. The program is based on the concept of stress superposition; addition of curvature-related local tensile stress and regional far-field stress. The method accurately predicts fractures on many Middle East Oil Fields that were formed under a strike slip regime as duplexes, flower structures or inverted structures. The program operates on the Excel platform. The program reads the parameters and structural grid data from an Excel template and writes the results to the same template. The program has two routines to import structural grid data in the Eclipse and Zmap formats. The platform of SUPERPOSE is a single layer structural grid of a given cell size (e.g. 50×50 m). In the final output, a single tensile or two conjugate shear fractures are placed in each cell if fracturing criteria are satisfied; otherwise the cell is left blank. Strike of the representative fracture(s) is calculated and exact, but the length is an index of fracture porosity (fracture density×length×aperture) within that cell.
NASA Astrophysics Data System (ADS)
Ignace, R.; Hendry, M. A.
2000-07-01
We derive a method for inverting emission-line profiles formed in supernova ejecta. The derivation assumes spherical symmetry and homologous expansion [i.e., v(r)~r], is analytic, and even takes account of occultation by a pseudophotosphere. Previous inversion methods have been developed that are restricted to optically thin lines, but the particular case of homologous expansion permits an analytic result for lines of arbitrary optical depth. In fact, we show that the quantity that is generically retrieved is the run of line intensity Iλ with radius in the ejecta. This result is quite general and so could be applied to resonance lines, recombination lines, etc. As a specific example, we show how to derive the run of (Sobolev) optical depth τλ with radius in the case of a pure resonance scattering emission line.
NASA Astrophysics Data System (ADS)
Ignace, R.; Hendry, M. A.
2000-05-01
We have derived a method for inverting emission line profiles formed in supernova ejecta. The derivation assumes spherical symmetry and homologous expansion (i.e., v(r) r). The inversion is analytic and even takes account of occultation by a pseudo-photosphere. Previous inversion methods have been developed which are restricted to optically thin lines, but the particular case of homologous expansion permits an analytic inversion for lines of arbitrary optical depth. In fact, we show that the quantity that is generically retrieved is the run of line intensity Iλ with radius in the ejecta shell. This result could be applied to resonance lines, recombination lines, or lines dominated by collisional de-excitation.
NASA Technical Reports Server (NTRS)
Starnes, James H., Jr.; Ambur, Damodar R.; Young, Richard D.; Harris, Charles E.
1999-01-01
Experimental and analysis results for a curved, stiffened aluminum fuselage panel tested in a combined loads test machine with combined internal pressure, axial compression, and torsional shear loads are described. The experimental and analytical strain results for the panel with and without discrete source damage are presented. The effect of notch tip geometry on crack growth predictions is addressed. The crack growth trajectory predictions for the panel are presented for the applied loading conditions at failure.
Analytical invariant manifolds near unstable points and the structure of chaos
NASA Astrophysics Data System (ADS)
Efthymiopoulos, Christos; Contopoulos, George; Katsanikas, Matthaios
2014-08-01
It is known that the asymptotic invariant manifolds around an unstable periodic orbit in conservative systems can be represented by convergent series (Cherry, Proc Lond Math Soc ser 2, 27:151-170, 1926; Moser, Commun Pure Appl Math 9:673, 1956 and 11:257, 1958; Moser, Giorgilli, Discret Contin Dyn Syst 7:855, 2001). The unstable and stable manifolds intersect at an infinity of homoclinic points, generating a complicated homoclinic tangle. In the case of simple mappings it was found (Da Silva Ritter et al., Phys D 29:181, 1987) that the domain of convergence of the formal series extends to infinity along the invariant manifolds. This allows in practice the study of the homoclinic tangle using only series. However in the case of Hamiltonian systems, or mappings with a finite analyticity domain, the convergence of the series along the asymptotic manifolds is also finite. Here, we provide numerical indications that the convergence does not reach any homoclinic points. We discuss in detail the convergence problem in various cases and we find the degree of approximation of the analytical invariant manifolds to the real (numerical) manifolds as (i) the order of truncation of the series increases, and (ii) we use higher numerical precision in computing the coefficients of the series. Then we introduce a new method of series composition, by using action-angle variables, that allows the calculation of the asymptotic manifolds up to an a arbitrarily large extent. This is the first case of an analytic development that allows the computation of the invariant manifolds and their intersections in a Hamiltonian system for an extent long enough to allow the study of homoclinic chaos by analytical means.
Solar Supergranulation Revealed as a Superposition of Traveling Waves
NASA Technical Reports Server (NTRS)
Gizon, L.; Duvall, T. L., Jr.; Schou, J.; Oegerle, William (Technical Monitor)
2002-01-01
40 years ago two new solar phenomena were described: supergranulation and the five-minute solar oscillations. While the oscillations have since been explained and exploited to determine the properties of the solar interior, the supergranulation has remained unexplained. The supergranules, appearing as convective-like cellular patterns of horizontal outward flow with a characteristic diameter of 30 Mm and an apparent lifetime of 1 day, have puzzling properties, including their apparent superrotation and the minute temperature variations over the cells. Using a 60-day sequence of data from the MDI (Michelson-Doppler Imager) instrument onboard the SOHO (Solar and Heliospheric Observatory) spacecraft, we show that the supergranulation pattern is formed by a superposition of traveling waves with periods of 5-10 days. The wave power is anisotropic with excess power in the direction of rotation and toward the equator, leading to spurious rotation rates and north-south flows as derived from correlation analyses. These newly discovered waves could play an important role in maintaining differential rotation in the upper convection zone by transporting angular momentum towards the equator.
Superposition, Transition Probabilities and Primitive Observables in Infinite Quantum Systems
NASA Astrophysics Data System (ADS)
Buchholz, Detlev; Størmer, Erling
2015-10-01
The concepts of superposition and of transition probability, familiar from pure states in quantum physics, are extended to locally normal states on funnels of type I∞ factors. Such funnels are used in the description of infinite systems, appearing for example in quantum field theory or in quantum statistical mechanics; their respective constituents are interpreted as algebras of observables localized in an increasing family of nested spacetime regions. Given a generic reference state (expectation functional) on a funnel, e.g. a ground state or a thermal equilibrium state, it is shown that irrespective of the global type of this state all of its excitations, generated by the adjoint action of elements of the funnel, can coherently be superimposed in a meaningful manner. Moreover, these states are the extreme points of their convex hull and as such are analogues of pure states. As further support of this analogy, transition probabilities are defined, complete families of orthogonal states are exhibited and a one-to-one correspondence between the states and families of minimal projections on a Hilbert space is established. The physical interpretation of these quantities relies on a concept of primitive observables. It extends the familiar framework of observable algebras and avoids some counter intuitive features of that setting. Primitive observables admit a consistent statistical interpretation of corresponding measurements and their impact on states is described by a variant of the von Neumann-Lüders projection postulate.
Fugacity superposition: a new approach to dynamic multimedia fate modeling.
Hertwich, E G
2001-08-01
The fugacities, concentrations, or inventories of pollutants in environmental compartments as determined by multimedia environmental fate models of the Mackay type can be superimposed on each other. This is true for both steady-state (level III) and dynamic (level IV) models. Any problem in multimedia fate models with linear, time-invariant transfer and transformation coefficients can be solved through a superposition of a set of n independent solutions to a set of coupled, homogeneous first-order differential equations, where n is the number of compartments in the model. For initial condition problems in dynamic models, the initial inventories can be separated, e.g. by a compartment. The solution is obtained by adding the single-compartment solutions. For time-varying emissions, a convolution integral is used to superimpose solutions. The advantage of this approach is that the differential equations have to be solved only once. No numeric integration is required. Alternatively, the dynamic model can be simplified to algebraic equations using the Laplace transform. For time-varying emissions, the Laplace transform of the model equations is simply multiplied with the Laplace transform of the emission profile. It is also shown that the time-integrated inventories of the initial conditions problems are the same as the inventories in the steady-state problem. This implies that important properties of pollutants such as potential dose, persistence, and characteristic travel distance can be derived from the steady state.
Hybrid multi-Bernoulli CPHD filter for superpositional sensors
NASA Astrophysics Data System (ADS)
Nannuru, Santosh; Coates, Mark
2014-06-01
We propose, for the super-positional sensor scenario, a hybrid between the multi-Bernoulli filter and the cardinalized probability hypothesis density (CPHD) filter. We use a multi-Bernoulli random finite set (RFS) to model existing targets and we use an independent and identically distributed cluster (IIDC) RFS to model newborn targets and targets with low probability of existence. Our main contributions are providing the update equations of the hybrid filter and identifying computationally tractable approximations. We achieve this by defining conditional probability hypothesis densities (PHDs), where the conditioning is on one of the targets having a specified state. The filter performs an approximate Bayes update of the conditional PHDs. In parallel, we perform a cardinality update of the IIDC RFS component in order to estimate the number of newborn targets. We provide an auxiliary particle filter based implementation of the proposed filter and compare it with CPHD and multi-Bernoulli filters in a simulated multitarget tracking application
NASA Astrophysics Data System (ADS)
Dalla Pozza, Nicola; Wiseman, Howard M.; Huntington, Elanor H.
2015-01-01
The preparation stage of optical qubits is an essential task in all the experimental setups employed for the test and demonstration of quantum optics principles. We consider a deterministic protocol for the preparation of qubits as a superposition of vacuum and one photon number states, which has the advantage to reduce the amount of resources required via phase-sensitive measurements using a local oscillator (‘dyne detection’). We investigate the performances of the protocol using different phase measurement schemes: homodyne, heterodyne, and adaptive dyne detection (involving a feedback loop). First, we define a suitable figure of merit for the prepared state and we obtain an analytical expression for that in terms of the phase measurement considered. Further, we study limitations that the phase measurement can exhibit, such as delay or limited resources in the feedback strategy. Finally, we evaluate the figure of merit of the protocol for different mode-shapes handily available in an experimental setup. We show that even in the presence of such limitations simple feedback algorithms can perform surprisingly well, outperforming the protocols when simple homodyne or heterodyne schemes are employed.
Marchal, Axel; Génin, Eric; Waffo-Téguo, Pierre; Bibès, Alice; Da Costa, Grégory; Mérillon, Jean-Michel; Dubourdieu, Denis
2015-01-01
Volatile and non-volatile molecules are directly responsible for the thrill and excitement provided by wine-tasting. Their elucidation requires powerful analytical techniques and innovative methodologies. In a recent work, two novel sweet compounds called quercotriterpenosides (QTT) were identified in oak wood used for wine-ageing. The aim of the present study is to discover structural analogs of such natural sweeteners in oak wood. For this purpose, an analytical approach was developed as an alternative to chemical synthesis. Orbitrap mass spectrometry proved to be a crucial technique both to demonstrate the presence of QTT analogs in oak wood by targeted screening and to guide the purification pathway of these molecules using complementary chromatographic tools. Four compounds were isolated and identified for the first time: two isomers, one glucosyl derivative and one galloyl derivative of QTT. Their tasting showed that only the two new isomers were sweet, thus demonstrating both the pertinence of the strategy and the influence of functional groups on gustatory properties. Finally, this paper presents some developments involving multistage Fourier transform mass spectrometry (FTMS) to provide solid structural information on these functional groups prior to any purification of compounds. Such analytical developments could be particularly useful for research on taste-active or bio-active products.
Analytical Challenges in Biotechnology.
ERIC Educational Resources Information Center
Glajch, Joseph L.
1986-01-01
Highlights five major analytical areas (electrophoresis, immunoassay, chromatographic separations, protein and DNA sequencing, and molecular structures determination) and discusses how analytical chemistry could further improve these techniques and thereby have a major impact on biotechnology. (JN)
NASA Technical Reports Server (NTRS)
Ko, William L.; Fleischer, Van Tran
2012-01-01
New first- and second-order displacement transfer functions have been developed for deformed shape calculations of nonuniform cross-sectional beam structures such as aircraft wings. The displacement transfer functions are expressed explicitly in terms of beam geometrical parameters and surface strains (uniaxial bending strains) obtained at equally spaced strain stations along the surface of the beam structure. By inputting the measured or analytically calculated surface strains into the displacement transfer functions, one could calculate local slopes, deflections, and cross-sectional twist angles of the nonuniform beam structure for mapping the overall structural deformed shapes for visual display. The accuracy of deformed shape calculations by the first- and second-order displacement transfer functions are determined by comparing these values to the analytically predicted values obtained from finite element analyses. This comparison shows that the new displacement transfer functions could quite accurately calculate the deformed shapes of tapered cantilever tubular beams with different tapered angles. The accuracy of the present displacement transfer functions also are compared to those of the previously developed displacement transfer functions.
Mass spectrometry in sports drug testing: Structure characterization and analytical assays.
Thevis, Mario; Schänzer, Wilhelm
2007-01-01
Owing to the sensitive, selective, and unambiguous nature of mass spectrometric analyses, chromatographic techniques interfaced to various kinds of mass spectrometers have become the most frequently employed strategy in the fight against doping. To obtain utmost confidence in analytical assays, mass spectrometric characterization of target analytes and typical dissociation pathways have been utilized as basis for the development of reliable and robust screening as well as confirmation procedures. Methods for qualitative and/or quantitative determinations of prohibited low and high molecular weight drugs have been established in doping control laboratories preferably employing gas or liquid chromatography combined with electron, chemical, or atmospheric pressure ionization followed by analyses using quadrupole, ion trap, linear ion trap, or hyphenated techniques. The versatility of modern mass spectrometers enable specific as well as comprehensive measurements allowing sports drug testing laboratories to determine the misuse of therapeutics such as anabolic-androgenic steroids, stimulants, masking agents or so-called designer drugs in athletes' blood or urine specimens, and a selection of recent developments is summarized in this review.
Sotnikov, V.; Kim, T.; Lundberg, J.; Paraschiv, I.; Mehlhorn, T. A.
2014-05-15
The presence of plasma turbulence can strongly influence propagation properties of electromagnetic signals used for surveillance and communication. In particular, we are interested in the generation of low frequency plasma density irregularities in the form of coherent vortex structures. Interchange or flute type density irregularities in magnetized plasma are associated with Rayleigh-Taylor type instability. These types of density irregularities play an important role in refraction and scattering of high frequency electromagnetic signals propagating in the earth ionosphere, in high energy density physics, and in many other applications. We will discuss scattering of high frequency electromagnetic waves on low frequency density irregularities due to the presence of vortex density structures associated with interchange instability. We will also present particle-in-cell simulation results of electromagnetic scattering on vortex type density structures using the large scale plasma code LSP and compare them with analytical results.
Fasoli, Diego; Faugeras, Olivier; Panzeri, Stefano
2015-01-01
We introduce a new formalism for evaluating analytically the cross-correlation structure of a finite-size firing-rate network with recurrent connections. The analysis performs a first-order perturbative expansion of neural activity equations that include three different sources of randomness: the background noise of the membrane potentials, their initial conditions, and the distribution of the recurrent synaptic weights. This allows the analytical quantification of the relationship between anatomical and functional connectivity, i.e. of how the synaptic connections determine the statistical dependencies at any order among different neurons. The technique we develop is general, but for simplicity and clarity we demonstrate its efficacy by applying it to the case of synaptic connections described by regular graphs. The analytical equations so obtained reveal previously unknown behaviors of recurrent firing-rate networks, especially on how correlations are modified by the external input, by the finite size of the network, by the density of the anatomical connections and by correlation in sources of randomness. In particular, we show that a strong input can make the neurons almost independent, suggesting that functional connectivity does not depend only on the static anatomical connectivity, but also on the external inputs. Moreover we prove that in general it is not possible to find a mean-field description à la Sznitman of the network, if the anatomical connections are too sparse or our three sources of variability are correlated. To conclude, we show a very counterintuitive phenomenon, which we call stochastic synchronization, through which neurons become almost perfectly correlated even if the sources of randomness are independent. Due to its ability to quantify how activity of individual neurons and the correlation among them depends upon external inputs, the formalism introduced here can serve as a basis for exploring analytically the computational capability of
Real-time dose computation: GPU-accelerated source modeling and superposition/convolution
Jacques, Robert; Wong, John; Taylor, Russell; McNutt, Todd
2011-01-15
Purpose: To accelerate dose calculation to interactive rates using highly parallel graphics processing units (GPUs). Methods: The authors have extended their prior work in GPU-accelerated superposition/convolution with a modern dual-source model and have enhanced performance. The primary source algorithm supports both focused leaf ends and asymmetric rounded leaf ends. The extra-focal algorithm uses a discretized, isotropic area source and models multileaf collimator leaf height effects. The spectral and attenuation effects of static beam modifiers were integrated into each source's spectral function. The authors introduce the concepts of arc superposition and delta superposition. Arc superposition utilizes separate angular sampling for the total energy released per unit mass (TERMA) and superposition computations to increase accuracy and performance. Delta superposition allows single beamlet changes to be computed efficiently. The authors extended their concept of multi-resolution superposition to include kernel tilting. Multi-resolution superposition approximates solid angle ray-tracing, improving performance and scalability with a minor loss in accuracy. Superposition/convolution was implemented using the inverse cumulative-cumulative kernel and exact radiological path ray-tracing. The accuracy analyses were performed using multiple kernel ray samplings, both with and without kernel tilting and multi-resolution superposition. Results: Source model performance was <9 ms (data dependent) for a high resolution (400{sup 2}) field using an NVIDIA (Santa Clara, CA) GeForce GTX 280. Computation of the physically correct multispectral TERMA attenuation was improved by a material centric approach, which increased performance by over 80%. Superposition performance was improved by {approx}24% to 0.058 and 0.94 s for 64{sup 3} and 128{sup 3} water phantoms; a speed-up of 101-144x over the highly optimized Pinnacle{sup 3} (Philips, Madison, WI) implementation. Pinnacle{sup 3
The principle of superposition and its application in ground-water hydraulics
Reilly, Thomas E.; Franke, O. Lehn; Bennett, Gordon D.
1987-01-01
The principle of superposition, a powerful mathematical technique for analyzing certain types of complex problems in many areas of science and technology, has important applications in ground-water hydraulics and modeling of ground-water systems. The principle of superposition states that problem solutions can be added together to obtain composite solutions. This principle applies to linear systems governed by linear differential equations. This report introduces the principle of superposition as it applies to ground-water hydrology and provides background information, discussion, illustrative problems with solutions, and problems to be solved by the reader.
The principle of superposition and its application in ground-water hydraulics
Reilly, T.E.; Franke, O.L.; Bennett, G.D.
1984-01-01
The principle of superposition, a powerful methematical technique for analyzing certain types of complex problems in many areas of science and technology, has important application in ground-water hydraulics and modeling of ground-water systems. The principle of superposition states that solutions to individual problems can be added together to obtain solutions to complex problems. This principle applies to linear systems governed by linear differential equations. This report introduces the principle of superposition as it applies to groundwater hydrology and provides background information, discussion, illustrative problems with solutions, and problems to be solved by the reader. (USGS)
NASA Technical Reports Server (NTRS)
Gedge, M. R.
1979-01-01
Analytical models were developed to study the effect of flow contraction and screening on inflow distortions to identify qualitative design criteria. Results of the study are that: (1) static testing distortions are due to atmospheric turbulence, nacelle boundary layer, exhaust flow reingestion, flow over stand, ground plane, and engine casing; (2) flow contraction suppresses, initially, turbulent axial velocity distortions and magnifies turbulent transverse velocity distortions; (3) perforated plate and gauze screens suppress axial components of velocity distortions to a degree determined by the screen pressure loss coefficient; (4) honeycomb screen suppress transverse components of velocity distortions to a degree determined by the length to diameter ratio of the honeycomb; (5) acoustic transmission loss of perforated plate is controlled by the reactance of its acoustic impedance; (6) acoustic transmission loss of honeycomb screens is negligible; and (7) a model for the direction change due to a corner between honeycomb panels compares favorably with measured data.
The analytic structure of non-global logarithms: Convergence of the dressed gluon expansion
Larkoski, Andrew J.; Moult, Ian; Neill, Duff Austin
2016-11-15
Non-global logarithms (NGLs) are the leading manifestation of correlations between distinct phase space regions in QCD and gauge theories and have proven a challenge to understand using traditional resummation techniques. Recently, the dressed gluon ex-pansion was introduced that enables an expansion of the NGL series in terms of a “dressed gluon” building block, defined by an all-orders factorization theorem. Here, we clarify the nature of the dressed gluon expansion, and prove that it has an infinite radius of convergence as a solution to the leading logarithmic and large-Nc master equation for NGLs, the Banfi-Marchesini-Smye (BMS) equation. The dressed gluon expansionmore » therefore provides an expansion of the NGL series that can be truncated at any order, with reliable uncertainty estimates. In contrast, manifest in the results of the fixed-order expansion of the BMS equation up to 12-loops is a breakdown of convergence at a finite value of αslog. We explain this finite radius of convergence using the dressed gluon expansion, showing how the dynamics of the buffer region, a region of phase space near the boundary of the jet that was identified in early studies of NGLs, leads to large contributions to the fixed order expansion. We also use the dressed gluon expansion to discuss the convergence of the next-to-leading NGL series, and the role of collinear logarithms that appear at this order. Finally, we show how an understanding of the analytic behavior obtained from the dressed gluon expansion allows us to improve the fixed order NGL series using conformal transformations to extend the domain of analyticity. Furthermore, this allows us to calculate the NGL distribution for all values of αslog from the coefficients of the fixed order expansion.« less
The analytic structure of non-global logarithms: Convergence of the dressed gluon expansion
Larkoski, Andrew J.; Moult, Ian; Neill, Duff Austin
2016-11-15
Non-global logarithms (NGLs) are the leading manifestation of correlations between distinct phase space regions in QCD and gauge theories and have proven a challenge to understand using traditional resummation techniques. Recently, the dressed gluon ex-pansion was introduced that enables an expansion of the NGL series in terms of a “dressed gluon” building block, defined by an all-orders factorization theorem. Here, we clarify the nature of the dressed gluon expansion, and prove that it has an infinite radius of convergence as a solution to the leading logarithmic and large-N_{c} master equation for NGLs, the Banfi-Marchesini-Smye (BMS) equation. The dressed gluon expansion therefore provides an expansion of the NGL series that can be truncated at any order, with reliable uncertainty estimates. In contrast, manifest in the results of the fixed-order expansion of the BMS equation up to 12-loops is a breakdown of convergence at a finite value of α_{s}log. We explain this finite radius of convergence using the dressed gluon expansion, showing how the dynamics of the buffer region, a region of phase space near the boundary of the jet that was identified in early studies of NGLs, leads to large contributions to the fixed order expansion. We also use the dressed gluon expansion to discuss the convergence of the next-to-leading NGL series, and the role of collinear logarithms that appear at this order. Finally, we show how an understanding of the analytic behavior obtained from the dressed gluon expansion allows us to improve the fixed order NGL series using conformal transformations to extend the domain of analyticity. Furthermore, this allows us to calculate the NGL distribution for all values of α_{s}log from the coefficients of the fixed order expansion.
Design of cryogenic tanks for space vehicles shell structures analytical modeling
NASA Technical Reports Server (NTRS)
Copper, Charles; Mccarthy, K.; Pilkey, W. D.; Haviland, J. K.
1991-01-01
The initial objective was to study the use of superplastically formed corrugated hat section stringers and frames in place of integrally machined stringers over separate frames for the tanks of large launch vehicles subjected to high buckling loads. The ALS was used as an example. The objective of the follow-on project was to study methods of designing shell structures subjected to severe combinations of structural loads and thermal gradients, with emphasis on new combinations of structural arrangements and materials. Typical applications would be to fuselage sections of high speed civil transports and to cryogenic tanks on the National Aerospace Plane.
NASA Astrophysics Data System (ADS)
Simpson, A.
2009-04-01
NMR Spectroscopy is arguably the most powerful tool to elucidate structure and probe molecular interactions. A range of NMR approaches will be introduced with emphasis on addressing and understanding structure and reactivity of soil organic matter at the molecular level. The presentation will be split into three main sections. The first section will look at evidence from advanced NMR based approaches that when considered synergistically describes the major structural components in soil organic matter. Multidimensional NMR spectroscopy (1-3D NMR), automated pattern matching, spectral simulations, diffusion NMR and hybrid-diffusion NMR will be introduced in context of molecular structure. Finally the structural components in soil will be contrasted to those found in aquatic dissolved organic matter. Secondly molecular interactions of natural organic matter will be considered. Advanced structural studies have provided detailed spectral assignments which in turn permit the reactivity of various soil components to be elucidated. Aggregation and self-association of soil and dissolved organic matter will be discussed along with the structural components likely responsible for aggregation/colloid formation. Interactions of soil organic matter with anthropogenic chemicals will also be considered and NMR techniques based on "Saturation Transfer Difference" introduced. These techniques are extremely powerful and can be used to both; describe mechanistically how anthropogenic chemicals sorb to whole soils and identify the structural components (lignin, protein, cellulose, etc..) that are responsible for the binding/sorption in soil. In the last section, the "big questions" and challenges facing the field will be considered along with some novel experimental NMR based approaches that should, in future, assist in providing answers to these questions.
Schniering, Carolyn A; Rapee, Ronald M
2004-02-01
The aim of this study was to examine the nature and organization of a range of negative self-statements in children and adolescents, using a structural equations/confirmatory factor-analytic approach. A community sample of 978 children aged 7-16 years completed a questionnaire about the frequency with which they experienced a broad range of negative automatic thoughts. The outcome of comparative modeling provided strongest support for a model in which 4 distinct cognitive factors were all related to a single higher order factor. The 4 lower order factors related to cognitions on social threat, physical threat, personal failure, and hostility. The pattern of results was consistent across age and gender. Results were consistent with assumptions of cognitive specificity models of psychopathology, on the latent structure of automatic thoughts in children and adolescents.
ERIC Educational Resources Information Center
Waern, Yvonne
It is suggested that a reader's idea structure will affect processing of incoming information. Two aspects of the idea structure are further developed--the truth value aspect and the analytic level aspect. The idea structure can be characterized by ideas consisting of propositions which are considered to be more or less true or false (beliefs), or…
Collapsing a perfect superposition to a chosen quantum state without measurement.
Younes, Ahmed; Abdel-Aty, Mahmoud
2014-01-01
Given a perfect superposition of [Formula: see text] states on a quantum system of [Formula: see text] qubits. We propose a fast quantum algorithm for collapsing the perfect superposition to a chosen quantum state [Formula: see text] without applying any measurements. The basic idea is to use a phase destruction mechanism. Two operators are used, the first operator applies a phase shift and a temporary entanglement to mark [Formula: see text] in the superposition, and the second operator applies selective phase shifts on the states in the superposition according to their Hamming distance with [Formula: see text]. The generated state can be used as an excellent input state for testing quantum memories and linear optics quantum computers. We make no assumptions about the used operators and applied quantum gates, but our result implies that for this purpose the number of qubits in the quantum register offers no advantage, in principle, over the obvious measurement-based feedback protocol.
Reproducible mesoscopic superpositions of Bose-Einstein condensates and mean-field chaos
Gertjerenken, Bettina; Arlinghaus, Stephan; Teichmann, Niklas; Weiss, Christoph
2010-08-15
In a parameter regime for which the mean-field (Gross-Pitaevskii) dynamics becomes chaotic, mesoscopic quantum superpositions in phase space can occur in a double-well potential, which is shaken periodically. For experimentally realistic initial states, such as the ground state of some 100 atoms, the emergence of mesoscopic quantum superpositions in phase space is investigated numerically. It is shown to be reproducible, even if the initial conditions change slightly. Although the final state is not a perfect superposition of two distinct phase states, the superposition is reached an order of magnitude faster than in the case of the collapse-and-revival phenomenon. Furthermore, a generator of entanglement is identified.
Superpositioning of Digital Elevation Data with Analog Imagery for Data Editing,
1984-01-01
The Topographic Developments Laboratory of the U.S. Army Engineer Topographic Laboratories (ETL) has established the Photogrammetric Technology ... Integration (PTI) testbed system for the evaluation of superpositioning techniques utilizing electronically scanned hardcopy imagery with overlayed digital
Accuracy of a teleported squeezed coherent-state superposition trapped into a high-Q cavity
Sales, J. S.; Silva, L. F. da; Almeida, N. G. de
2011-03-15
We propose a scheme to teleport a superposition of squeezed coherent states from one mode of a lossy cavity to one mode of a second lossy cavity. Based on current experimental capabilities, we present a calculation of the fidelity demonstrating that accurate quantum teleportation can be achieved for some parameters of the squeezed coherent states superposition. The signature of successful quantum teleportation is present in the negative values of the Wigner function.
Spagnolo, Nicolo; Sciarrino, Fabio; De Martini, Francesco
2010-09-15
We show that the quantum states generated by universal optimal quantum cloning of a single photon represent a universal set of quantum superpositions resilient to decoherence. We adopt the Bures distance as a tool to investigate the persistence of quantum coherence of these quantum states. According to this analysis, the process of universal cloning realizes a class of quantum superpositions that exhibits a covariance property in lossy configuration over the complete set of polarization states in the Bloch sphere.
Strong-Driving-Assisted Preparation of Superpositions of Two-Mode Coherent States in Cavity QED
NASA Astrophysics Data System (ADS)
Su, Wan-Jun; Huang, Jian-Min
2011-09-01
A scheme is proposed for preparing the superposition of two-mode coherent states with controllable weighting factors along a straight line for two-mode cavity field. In this scheme two-level atoms driven by classical field are sent through a two-mode cavity initially in the vacuum state. Then the detection of the atoms make the cavity field be in a two-mode superpositions of coherent states.
Analytical monitoring of soil bioengineering structures in the Tuscan Emilian Apennines of Italy
NASA Astrophysics Data System (ADS)
Selli, Lavinia; Guastini, Enrico
2014-05-01
Soil bioengineering has been an appropriate solution to deal with erosion problems and shallow landslides in the North Apennines, Italy. The objective of our research was a check about critical aspects of soil bioengineering works. We monitored the works that have been carried out in the Tuscan Emilian Apennines by testing the suitability of different plant species and analyzed in detail timber structures of wooden crib walls. Plant species were mainly Salix alba and Salix purpurea that gave good sprouting and survival rates. However, showed some issues in growing on dry and sunny Apennine lands, where other shrubs like Spanish Broom, blackthorn, cornel-tree and Eglantine would be more indicated. The localized analysis on wooden elements has been led gathering parts from the poles and obtaining samples in order to determine their density. The hypothetical initial density of the wood used in the structure has been estimated, then calculating the residual density. This analysis allows us to determine the general condition of the wood, highlighting the structures in worst condition (the one in Pianaccio show a residual density close to 70%, instead of 90% as found on other structures) and those whose degraded wood has undergone the greatest damage (Pianaccio here too, with 50%, followed by Campoferrario - 60% - and by Pian di Favale with 85%, a rather good value for the most degraded wood in the structure).
Methodological developments and strategies for a fast flexible superposition of drug-size molecules.
Klebe, G; Mietzner, T; Weber, F
1999-01-01
An alternative to experimental high through-put screening is the virtual screening of compound libraries on the computer. In absence of a detailed structure of the receptor protein, candidate molecules are compared with a known reference by mutually superimposing their skeletons and scoring their similarity. Since molecular shape highly depends on the adopted conformation, an efficient conformational screening is performed using a knowledge-based approach. A comprehensive torsion library has been compiled from crystal data stored in the Cambridge Structural Database. For molecular comparison a strategy is followed considering shape associated physicochemical properties in space such as steric occupancy, electrostatics, lipophilicity and potential hydrogen-bonding. Molecular shape is approximated by a set of Gaussian functions not necessarily located at the atomic positions. The superposition is performed in two steps: first by a global alignment search operating on multiple rigid conformations and then by conformationally relaxing the best scored hits of the global search. A normalized similarity scoring is used to allow for a comparison of molecules with rather different shape and size. The approach has been implemented on a cluster of parallel processors. As a case study, the search for ligands binding to the dopamine receptor is given.
Methodological developments and strategies for a fast flexible superposition of drug-size molecules
NASA Astrophysics Data System (ADS)
Klebe, Gerhard; Mietzner, Thomas; Weber, Frank
1999-01-01
An alternative to experimental high through-put screening is the virtual screening of compound libraries on the computer. In absence of a detailed structure of the receptor protein, candidate molecules are compared with a known reference by mutually superimposing their skeletons and scoring their similarity. Since molecular shape highly depends on the adopted conformation, an efficient conformational screening is performed using a knowledge-based approach. A comprehensive torsion library has been compiled from crystal data stored in the Cambridge Structural Database. For molecular comparison a strategy is followed considering shape associated physicochemical properties in space such as steric occupancy, electrostatics, lipophilicity and potential hydrogen-bonding. Molecular shape is approximated by a set of Gaussian functions not necessarily located at the atomic positions. The superposition is performed in two steps: first by a global alignment search operating on multiple rigid conformations and then by conformationally relaxing the best scored hits of the global search. A normalized similarity scoring is used to allow for a comparison of molecules with rather different shape and size. The approach has been implemented on a cluster of parallel processors. As a case study, the search for ligands binding to the dopamine receptor is given.
Identification of Distant Drug Off-Targets by Direct Superposition of Binding Pocket Surfaces
Schumann, Marcel; Armen, Roger S.
2013-01-01
Correctly predicting off-targets for a given molecular structure, which would have the ability to bind a large range of ligands, is both particularly difficult and important if they share no significant sequence or fold similarity with the respective molecular target (“distant off-targets”). A novel approach for identification of off-targets by direct superposition of protein binding pocket surfaces is presented and applied to a set of well-studied and highly relevant drug targets, including representative kinases and nuclear hormone receptors. The entire Protein Data Bank is searched for similar binding pockets and convincing distant off-target candidates were identified that share no significant sequence or fold similarity with the respective target structure. These putative target off-target pairs are further supported by the existence of compounds that bind strongly to both with high topological similarity, and in some cases, literature examples of individual compounds that bind to both. Also, our results clearly show that it is possible for binding pockets to exhibit a striking surface similarity, while the respective off-target shares neither significant sequence nor significant fold similarity with the respective molecular target (“distant off-target”). PMID:24391782
NASA Technical Reports Server (NTRS)
Simpson, Myles A.; Mathur, Gopal P.
1992-01-01
Measurements conducted on a DC-9 aircraft test section to define the shell and cavity modes of the fuselage, understand its structural-acoustic coupling characteristics, and measure its response to different types of acoustic and vibration excitations are reported. The data were processed to generate spatial plots and wavenumber maps of the shell acceleration and cabin acoustic pressure field. Analysis and interpretation of the spatial plots and wavenumber maps showed that the only structural-acoustic coupling occurred at 105 Hz between the N=2 circumferential structural mode and the (n=2, p=0) circumferential cavity mode. The fuselage response to vibration excitation was found to be dominated by modes whose order increases with frequency.
Analytical and numerical investigation of structural response of compliant wall materials, part 1
NASA Technical Reports Server (NTRS)
Balasubramanian, R.
1978-01-01
Surface motion of compliant walls in drag reduction experiments was analyzed. Critical comparison was made between the dynamic motion of the structure and the postulated mechanism of drag reduction. The spectrum of surface motion indicated that membranes over deep cavities respond at low frequencies and large wavelengths. The membrane over a deep cavity is therefore found not to yield the desired response predicted by the postulated mechanism. The membrane over a thin air gap is found to act as a wavelength chopper, and analysis of the nonlinear response of that compliant surface indicated its possible suitability for compliant wall experiments. Periodic structures are found to lock in the desired wavelengths of motion, and it was shown that at least in Kramer's initial experiments they produced high frequency surface motions. Laminated structures are found to be very ineffective as compliant models, except when there is no bonding between the membrane and the backing. Computer programs developed for these analyses are documented.
SO(4) group structure for a motivated QCD Hamiltonian: Analytic and Tamm-Dancoff solutions
NASA Astrophysics Data System (ADS)
Yepez-Martinez, Tochtli; Civitarese, Osvaldo; Hess, Peter O.
2016-08-01
Starting from the QCD Hamiltonian written in the canonical Coulomb gauge formalism, we developed a mapping onto an SO(4) representation which is suitable for the description of the QCD spectra at low energies. The mapping does not break the flavor symmetry and it preserves the singlet-colorless structure of the states. We present and discuss the structure of integer and half-integer-spin states with masses below 2 GeV. Finally, we extend the formalism in order to include particle-hole-like correlations in building excitations.
Sensitivity-based scaling for correlating structural response from different analytical models
NASA Technical Reports Server (NTRS)
Chang, Kwan J.; Haftka, Raphael T.; Giles, Gary L.; Kao, Pi-Jen
1991-01-01
A sensitivity-based linearly varying scale factor is described used to reconcile results from refined models for analysis of the same structure. The improved accuracy of the linear scale factor compared to a constant scale factor as well as the commonly used tangent approximation is demonstrated. A wing box structure is used as an example, with displacements, stresses, and frequencies correlated. The linear scale factor could permit the use of a simplified model in an optimization procedure during preliminary design to approximate the response given by a refined model over a considerable range of design changes.
Transfer of arbitrary quantum emitter states to near-field photon superpositions in nanocavities.
Thijssen, Arthur C T; Cryan, Martin J; Rarity, John G; Oulton, Ruth
2012-09-24
We present a method to analyze the suitability of particular photonic cavity designs for information exchange between arbitrary superposition states of a quantum emitter and the near-field photonic cavity mode. As an illustrative example, we consider whether quantum dot emitters embedded in "L3" and "H1" photonic crystal cavities are able to transfer a spin superposition state to a confined photonic superposition state for use in quantum information transfer. Using an established dyadic Green's function (DGF) analysis, we describe methods to calculate coupling to arbitrary quantum emitter positions and orientations using the modified local density of states (LDOS) calculated using numerical finite-difference time-domain (FDTD) simulations. We find that while superposition states are not supported in L3 cavities, the double degeneracy of the H1 cavities supports superposition states of the two orthogonal modes that may be described as states on a Poincaré-like sphere. Methods are developed to comprehensively analyze the confined superposition state generated from an arbitrary emitter position and emitter dipole orientation.
Meta-Analytic Structural Equation Modeling: A Two-Stage Approach
ERIC Educational Resources Information Center
Cheung, Mike W. L.; Chan, Wai
2005-01-01
To synthesize studies that use structural equation modeling (SEM), researchers usually use Pearson correlations (univariate r), Fisher z scores (univariate z), or generalized least squares (GLS) to combine the correlation matrices. The pooled correlation matrix is then analyzed by the use of SEM. Questionable inferences may occur for these ad hoc…
NASA Astrophysics Data System (ADS)
Yang, Chao; Xiong, Jiayun; Wei, Jie; Wu, Junfeng; Peng, Fu; Deng, Siyu; Zhang, Bo; Luo, Xiaorong
2016-04-01
A novel enhancement-mode (E-mode) polarization-junction HEMT with vertical conduction channel (PVC-HEMT) is proposed, and its analytical model for threshold voltage (Vth) is presented. It has two features: one is GaN/AlGaN/GaN double hetero-structure, the other is that source and drain locate at the same side of trench-type MOS gate (T-gate), and the source contacts with the T-gate, which forms vertical conduction channel (VC). The 2-D hole gas (2-DHG) and 2-D electron gas (2-DEG) are formed at the GaN-top/AlGaN and AlGaN/GaN-buffer interface, respectively, forming the polarization-junction. First, the E-mode operation is realized because 2-DHG under the source prevents the electrons injecting from source to 2-DEG, breaking through the conventional E-mode method by depleting 2-DEG under the gate. Second, a uniform electric field (E-field) distribution is achieved due to the assisted depletion effect by polarization-junction. Third, the source reduces the E-field peak at the T-gate side and modulates the E-field distribution. The breakdown voltage (BV) of PVC-HEMT is 705 V and specific ON-resistance (RON,sp) is 1.18 mΩ cm2. Compared with conventional HEMT (C-HEMT), PVC-HEMT has a smaller size due to the special location of the source and T-gate. An analytic threshold voltage model is presented and the analytical results agree well with the simulated results.
Analytical and numerical investigation of structural response of compliant wall materials
NASA Technical Reports Server (NTRS)
Goglia, G. L.; Balasubramanian, R.
1977-01-01
Surface motion of compliant walls in drag reduction experiments was analyzed. The spectrum of surface motion indicates that membranes over deep cavities respond at low frequencies and large wavelengths. The membrane over a deep cavity is therefore found not to yield the desired reponse predicted by the postulated mechanism. The membrane over a thin air gap is found to act as a wavelength chopper, and analysis of the nonlinear response of the compliant surface indicates its possible suitability for compliant wall experiments. Periodic structures are found to lock in the desired wavelengths of motion. Laminated structures are found to be very ineffective as compliant models, except when there is no bonding between the membrane and the backing. Computer programs developed for these analyses are documented.
Molecular structure and analytical potential energy function of SeCO
NASA Astrophysics Data System (ADS)
Zhang, Heng; Tian, Duan-Liang; Yan, Shi-Ying
2014-09-01
The density functional method (B3P86/6-311G) is used for calculating the possible structures of SeC, SeO, and SeCO molecules. The result shows that the ground state of the SeC molecule is 1Σ, the equilibrium nuclear distance is RSeC = 0.1699 nm, and the dissociation energy is De = 8.7246 eV. The ground state of the SeO molecule is 3Σ, with equilibrium nuclear distance RSeO = 0.1707 nm and dissociation energy De = 7.0917 eV. There are two structures for the ground state of the SeCO molecule: Se=C=O and Se=O=C. The linear Se=C=O is 1Σ. Its equilibrium nuclear distances and dissociation energy are RSeC = 0.1715 nm, RCO = 0.1176 nm and 18.8492 eV, respectively. The other structure Se=O=C is 1Σ. Its equilibrium nuclear distances and dissociation energy are RCO = 0.1168 nm, RSeO = 0.1963 nm and 15.5275 eV, respectively. The possible dissociative limit of the SeCO molecule is analyzed. The potential energy function for the SeCO molecule has been obtained from the many-body expansion theory. The contour of the potential energy curve describes the structure characters of the SeCO molecule. Furthermore, contours of the molecular stretching vibration based on this potential energy function are discussed.
NASA Astrophysics Data System (ADS)
Cao, Chen; Zhang, Bing; Wu, Long-Sheng; Li, Na; Wang, Jun-Feng
2014-12-01
A quantum efficiency analytical model for complementary metal—oxide—semiconductor (CMOS) image pixels with a pinned photodiode structure is developed. The proposed model takes account of the non-uniform doping distribution in the N-type region due to the impurity compensation formed by the actual fabricating process. The characteristics of two boundary PN junctions located in the N-type region for the particular spectral response of a pinned photodiode, are quantitatively analyzed. By solving the minority carrier steady-state diffusion equations and the barrier region photocurrent density equations successively, the analytical relationship between the quantum efficiency and the corresponding parameters such as incident wavelength, N-type width, peak doping concentration, and impurity density gradient of the N-type region is established. The validity of the model is verified by the measurement results with a test chip of 160 × 160 pixels array, which provides the accurate process with a theoretical guidance for quantum efficiency design in pinned photodiode pixels.
PASCO: Structural panel analysis and sizing code, capability and analytical foundations
NASA Technical Reports Server (NTRS)
Stroud, W. J.; Anderson, M. S.
1980-01-01
A computer code denoted PASCO which can be used for analyzing and sizing uniaxially-stiffened composite panels is described. Buckling and vibration analyses are carried out with a linked-plate analysis computer code denoted VIPASA, which is incorporated in PASCO. Sizing is based on nonlinear mathematical programming techniques and employs a computer code denoted CONMIN, also incorporated in PASCO. Design requirements considered are initial buckling, material strength, stiffness, and vibration frequency. The capability of the PASCO computer code and the approach used in the structural analysis and sizing are described.
1987-10-01
Cermak, & F.I.M. Craik (Eds.), Levels of processing in human memory (pp. 23-44). Hillsdale, NJ: Erlbaum. Bourne, L.E., Jr. (1974). An inference model ...representative IS. KE9Y 6OROS (C@Wh-u an me M-00 Sd Oeeemy old NNmdIP’ 6 W806A min’) Cognition, Memory ., Skll s,%. [ Retention. . )- P The program described in...influencing and improving retention of skill components. The second part. is concerned with analysis and assessment of the structure of acquired memory
The Analytic Structure of Scattering Amplitudes in N = 4 Super-Yang-Mills Theory
NASA Astrophysics Data System (ADS)
Litsey, Sean Christopher
We begin the dissertation in Chapter 1 with a discussion of tree-level amplitudes in Yang-. Mills theories. The DDM and BCJ decompositions of the amplitudes are described and. related to one another by the introduction of a transformation matrix. This is related to the. Kleiss-Kuijf and BCJ amplitude identities, and we conjecture a connection to the existence. of a BCJ representation via a condition on the generalized inverse of that matrix. Under. two widely-believed assumptions, this relationship is proved. Switching gears somewhat, we introduce the RSVW formulation of the amplitude, and the extension of BCJ-like features to residues of the RSVW integrand is proposed. Using the previously proven connection of BCJ representations to the generalized inverse condition, this extension is validated, including a version of gravitational double copy. The remainder of the dissertation involves an analysis of the analytic properties of loop. amplitudes in N = 4 super-Yang-Mills theory. Chapter 2 contains a review of the planar case, including an exposition of dual variables and momentum twistors, dual conformal symmetry, and their implications for the amplitude. After defining the integrand and on-shell diagrams, we explain the crucial properties that the amplitude has no poles at infinite momentum and that its leading singularities are dual-conformally-invariant cross ratios, and can therefore be normalized to unity. We define the concept of a dlog form, and show that it is a feature of the planar integrand as well. This leads to the definition of a pure integrand basis. The proceeding setup is connected to the amplituhedron formulation, and we put forward the hypothesis that the amplitude is determined by zero conditions. Chapter 3 contains the primary computations of the dissertation. This chapter treats. amplitudes in fully nonplanar N = 4 super-Yang-Mills, analyzing the conjecture that they. follow the pattern of having no poles at infinity, can be written in dlog
NASA Astrophysics Data System (ADS)
Dhakal, S.; Bhandary, N. P.; Yatabe, R.; Kinoshita, N.
2012-04-01
In a previous companion paper, we presented a three-tier modelling of a particular type of rockfall protective cable-net structure (barrier), developed newly in Japan. Therein, we developed a three-dimensional, Finite Element based, nonlinear numerical model having been calibrated/back-calculated and verified with the element- and structure-level physical tests. Moreover, using a very simple, lumped-mass, single-degree-of-freedom, equivalently linear analytical model, a global-displacement-predictive correlation was devised by modifying the basic equation - obtained by combining the principles of conservation of linear momentum and energy - based on the back-analysis of the tests on the numerical model. In this paper, we use the developed models to explore the performance enhancement potential of the structure in terms of (a) the control of global displacement - possibly the major performance criterion for the proposed structure owing to a narrow space available in the targeted site, and (b) the increase in energy dissipation by the existing U-bolt-type Friction-brake Devices - which are identified to have performed weakly when integrated into the structure. A set of parametric investigations have revealed correlations to achieve the first objective in terms of the structure's mass, particularly by manipulating the wire-net's characteristics, and has additionally disclosed the effects of the impacting-block's parameters. Towards achieving the second objective, another set of parametric investigations have led to a proposal of a few innovative improvements in the constitutive behaviour (model) of the studied brake device (dissipator), in addition to an important recommendation of careful handling of the device based on the identified potential flaw.
NASA Astrophysics Data System (ADS)
Bani-Hani, M. A.; Karami, M. A.
2015-09-01
This paper presents vibration analysis and structural optimization of a swimming-morphing structure. The swimming of the structure is achieved by utilization of piezoelectric patches to generate traveling waves. The third mode shape of the structure in the longitudinal direction resembles the body waveform of a swimming eel. After swimming to its destination, the morphing structure changes shape from an open box to a cube using shape memory alloys (SMAs). The SMAs used for the configuration change of the box robot cannot be used for swimming since they fail to operate at high frequencies. Piezoelectric patches are actuated at the third natural frequency of the structure. We optimize the thickness of the panels and the stiffness of the springs at the joints to generate swimming waveforms that most closely resemble the body waveform of an eel. The traveling wave is generated using two piezoelectric sets of patches bonded to the first and last segments of the beams in the longitudinal direction. Excitation of the piezoelectric results in coupled system dynamics equations that can be translated into the generation of waves. Theoretical analysis based on the distributed parameter model is conducted in this paper. A scalar measure of the traveling to standing wave ratio is introduced using a 2-dimensional Fourier transform (2D-FFT) of the body deformation waveform. An optimization algorithm based on tuning the flexural transverse wave is established to obtain a higher traveling to standing wave ratio. The results are then compared to common methods in the literature for assessment of standing to traveling wave ratios. The analytical models are verified by the close agreement between the traveling waves predicted by the model and those measured in the experiments.
Shevyrin, Vadim; Melkozerov, Vladimir; Nevero, Alexander; Eltsov, Oleg; Shafran, Yuri; Morzherin, Yuri; Lebedev, Albert T
2015-08-01
Illicit new psychoactive substances (NPS) are a serious threat to health throughout the world. Such NPS do not usually pass preliminary pharmacological trials. In 2014, we identified a series of five new synthetic cannabinoids with an indazole-3-carboxamide structure bearing an N-1-methoxycarbonylalkyl group. The compounds have very high cannabimimetic activity which has caused mass severe intoxication and deaths. The compounds were identified by means of gas chromatography-mass spectrometry (GC-MS), including high-resolution mass spectrometry (GC-HRMS), ultra-high-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HRMS(2)), and (1)H and (13)C nuclear magnetic resonance spectroscopy (NMR). The peculiarities of mass-spectral fragmentation of the compounds after electron ionization (EI) ionization and collision-induced dissociation (CID) were studied. The analytical characteristics reported for the compounds will enable their identification in a variety of materials seized from criminals.Graphical Abstract.
NASA Astrophysics Data System (ADS)
Es-Safi, Nour-Eddine; Essassi, El Mokhtar; Massoui, Mohamed; Banoub, Joseph
Mass spectrometry is an important tool for the identification and structural elucidation of natural and synthesized compounds. Its high sensitivity and the possibility of coupling liquid chromatography with mass spectrometry detection make it a technique of choice for the investigation of complex mixtures like raw natural extracts. The mass spectrometer is a universal detector that can achieve very high sensitivity and provide information on the molecular mass. More detailed information can be subsequently obtained by resorting to collision-induced dissociation tandem mass spectrometry (CID-MS/MS). In this review, the application of mass spectrometric techniques for the identification of natural and synthetic compounds is presented. The gas-phase fragmentation patterns of a series of four natural flavonoid glycosides, three synthesized benzodiazepines and two synthesized quinoxalinone derivatives were investigated using electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry techniques. Exact accurate masses were measured using a modorate resolution quadrupole orthogonal time-of-flight QqTOF-MS/MS hybrid mass spectrometer instrument. Confirmation of the molecular masses and the chemical structures of the studied compounds were achieved by exploring the gas-phase breakdown routes of the ionized molecules. This was rationalized by conducting low-energy collision CID-MS/MS analyses (product ion- and precursor ion scans) using a conventional quadrupole hexapole-quadrupole (QhQ) tandem mass spectrometer.
NASA Astrophysics Data System (ADS)
Gong, J.; Thompson, L.; Li, G.
2016-12-01
A semi-analytical model for determining the equilibrium configuration and the radial breathing mode (RBM) frequency of single-wall carbon nanotubes (CNTs) is presented. By taking advantage of the symmetry characteristics, a CNT structure is represented by five independent variables. A line search optimization procedure is employed to determine the equilibrium values of these variables by minimizing the potential energy. With the equilibrium configuration obtained, the semi-analytical model enables an efficient calculation of the RBM frequency of the CNTs. The radius and radial breathing mode frequency results obtained from the semi-analytical approach are compared with those from molecular dynamics (MD) and ab initio calculations. The results demonstrate that the semi-analytical approach offers an efficient and accurate way to determine the equilibrium structure and radial breathing mode frequency of CNTs.
NASA Astrophysics Data System (ADS)
Hilson, Christopher William
Following the February 27, 2010 Mw 8.8 Maule earthquake, an international effort was undertaken to better understand reasons for observed damage to concrete structural walls in buildings located in the affected region of Chile and to address potential design implications. The Chilean building code for concrete structures is based on the U.S. ACI 318 building code; however, based on the observed performance of over 400 buildings in the March 1985 earthquake-impacted Vina del Mar, Chilean Code NCh433.Of96 included an exception that special boundary elements (SBEs)---which are commonly required for walls in U.S. buildings---need not be provided. By taking exception to the special boundary element detailing provisions, the Chilean code allowed thin wall boundary zones with relatively large (typically 20 cm) spacing of transverse reinforcement (essentially unconfined) to be constructed. Given these differences, the 2010 earthquake is an excellent opportunity to assess the performance of reinforced concrete buildings designed using modern codes similar to those used in the United States. Data from damaged and undamaged buildings, as well as from parametric and experimental studies, are used to provide recommendations to improve the efficacy of U.S. provisions designed to inhibit structural damage at wall boundaries. Seven Chilean buildings were selected to investigate the performance of boundary elements during the 2010 earthquake. Several walls from each of the seven buildings were chosen to evaluate the ACI 318-11 Section 21.9.6.2 displacement-based trigger equation for determining if SBEs would have been required and if observed damage was consistent with the evaluation result (i.e., SBE required, no damage; SBE required, damage observed). The propensity of boundary longitudinal reinforcement to buckle was also investigated, taking into consideration the influence of boundary transverse reinforcement configuration and longitudinal reinforcement strain history. In
Kodaka, Tetsuo; Sano, Tsuneyoshi; Nakagawa, Kunitoshi; Kakino, Jun; Mori, Ryoichi
2004-06-01
We observed the gross and fine structure of gallbladder stones collected from five adult patients (cases I-V) by optical photography, radiography, scanning electron microscopy, and backscattered electron microscopy, and then measured the components by energy-dispersive X-ray microanalysis and infrared spectroscopy. From the stones, calcium (Ca) phosphate, Ca bilirubinate, and Ca palmitate or fatty acid Ca were identified. The 3 cholesterol stones (case I) and the 2 brown pigment stones (case II) showed macroscopic homogeneity, respectively. In addition, their fine structure and components were also similar to each other. The black pigment stones (case III) showed macroscopic homogeneity, but they were divided into radiopaque (approximately 30 stones) and radiolucent types (approximately 60 stones). The former had Ca phosphate in the center surrounded with Ca bilirubinate, and the latter was dotted with minute deposits of Ca bilirubinate. The 6 cholesterol stones (case IV) were divided into two types in size. The 5 large stones, of macroscopic homogeneity, had a core region of Ca palmitate and clear concentric rings of Ca phosphate, whereas the smaller stone was almost filled with Ca phosphate deposits in the center. From the different distributions of Ca phosphate, the smaller stone may have been formed later than the 5 large stones. Case V contained 4 stones. The 3 large cholesterol stones, of more or less macroscopic homogeneity, had a core region and concentric rings of Ca phosphate, but 1 smaller stone was dotted with minute deposits mainly containing iron (Fe) and/or silicon elements (rare type). Therefore, the stones of cases III, IV, and V showed considerable heterogeneity, respectively. In many stones, the initial precipitation of Ca salts will have become the nidus, and the concentric rings and dotted deposits of Ca salts may have accelerated cholesterol stone growth. In addition, the dotted deposits of Ca bilirubinate in the black pigment stones and the
NASA Astrophysics Data System (ADS)
Mourgues, R.; Costa, A. C. G.; Marques, F. O.; Lacoste, A.; Hildenbrand, A.
2016-06-01
The critical taper theory of Coulomb wedges has been classically applied to compressive regimes (accretionary prisms/fold-and-thrust belts), and more recently to gravitational instabilities. Following the initial hypothesis of the theory, we provide an alternative expression of the exact solution for a non-cohesive wedge by considering the balance of forces applied to the external surfaces. Then, we use this approach to derive a solution for the case of cohesive wedges. We show that cohesion has conspicuous structural effects, including a minimum length required for sliding and the formation of listric faults. The stabilizing effect of cohesion is accentuated in the foremost thin domain of the wedge, defining a required Minimum Failure Length (MFL), and producing sliding of a rigid mass above the detachment. This MFL decreases with less cohesion, a smaller coefficient of internal friction, larger fluid overpressure ratio, and steeper upper and basal surfaces for the wedge. Listricity of the normal faults depends on the fluid overpressure magnitude within the wedge. For moderate fluid overpressure, normal faults are curved close to the surface, and become straight at depth. In contrast, where fluid overpressure exceeds a critical value corresponding to the fluid pressure required to destabilize the surface of a noncohesive wedge, the state of stress changes and rotates at depth. The faults are straight close to the surface and listric at depth, becoming parallel to the upper surface if the wedge is thick enough. We tested some of these structural effects of a cohesive wedge on gravitational instabilities using analogue models where cohesive material was subjected to pore-fluid pressure. The shape of the faults obtained in the models is consistent with the predictions of the theory.
NASA Astrophysics Data System (ADS)
Sotnikov, V.; Kim, T.; Lundberg, J.; Paraschiv, I.; Mehlhorn, T. A.
2014-10-01
Interchange or flute type density irregularities in magnetized plasma are associated with Rayleigh-Taylor type instability. In particular, we are interested in the generation of low frequency plasma density irregularities in the form of flute type vortex density structures and interaction of high frequency electromagnetic waves used for surveillance and communication with such structures. These types of density irregularities play an important role in refraction and scattering of high frequency electromagnetic signals propagating in the earth ionosphere, in high energy density physics (HEDP), and in many other applications. We will present PIC simulation results of EM scattering on vortex type density structures using the LSP code and compare them with analytical results. Two cases will be analyzed. In the first case electromagnetic wave scattering will take place in the ionospheric plasma. In the second case laser probing in a high-beta Z-pinch plasma will be presented. This work was supported by the Air Force Research laboratory, the Air Force Office of Scientific Research, the Naval Research Laboratory and NNSA/DOE Grant No. DE-FC52-06NA27616 at the University of Nevada at Reno.
Lebedev, D V; Baitin, D M; Islamov, A Kh; Kuklin, A I; Shalguev, V Kh; Lanzov, V A; Isaev-Ivanov, V V
2003-02-27
The filament structures of the self-polymers of RecA proteins from Escherichia coli and Pseudomonas aeruginosa, their complexes with ATPgammaS, phage M13 single-stranded DNA (ssDNA) and the tertiary complexes RecA::ATPgammaS::ssDNA were compared by small angle neutron scattering. A model was developed that allowed for an analytical solution for small angle scattering on a long helical filament, making it possible to obtain the helical pitch and the mean diameter of the protein filament from the scattering curves. The results suggest that the structure of the filaments formed by these two RecA proteins, and particularly their complexes with ATPgammaS, is conservative.
NASA Astrophysics Data System (ADS)
Ouyang, Chenxin; Xiao, Shumin; Zhu, Jianhua; Shi, Wei
2016-06-01
NiCuZn ferrites with the composition of (Ni0.48Cu0.10Zn0.42O)1.04(Fe2O3)0.96 were consolidated by microwave sintering (MS) and conventional sintering (CS), respectively. The influences of external microwave field and additives (1 wt% BSZ glass or 1 wt% Bi2O3) on the microstructure and DC-bias superposition characteristics of NiCuZn ferrites were investigated. Experimental results demonstrated that the final grain size was much larger with higher density since applying microwave field. In addition, for undoped ferrites, coarse grains structure obtained from microwave sintering is harmful to the DC-bias superposition characteristics. However, since adding BSZ glass or Bi2O3, the discrepancy on the final grain size obtained from MS and CS methods is not obvious. NiCuZn ferrites with the addition of BSZ glass or Bi2O3 exhibited a stronger ability to inhibit the drop of permeability under the DC-bias magnetic field. Possible mechanisms behind are discussed in this article.
Superposition of noncoaxial vortices in parametric wave mixing
NASA Astrophysics Data System (ADS)
Sukhorukov, Anatoly P.; Kalinovich, Alexey A.; Molina-Terriza, Gabriel; Torner, Lluis
2002-09-01
In this paper we present a comprehensive study of the dynamics of screw phase dislocations under conditions of noncoaxial parametric three-wave mixing in the pump low-depletion regime. Under such conditions the signal and idler fields couple and so, the fields' properties change through propagation in the nonlinear crystal. We present an analytical model and a comprehensive study of the vortical features of the resulting field. The model is compared with the numerical solutions of the full equations. It is shown that by changing the relative amplitude and phase of the initial fields, one can control the domains where creation and annihilation of vortex-antivortex twins lead to different vortex content. We show that the effects studied here are relevant to a variety of physical systems. In particular, we show that the same phenomena are expected to occur in gyrotropic media and photonic crystals.
Superposition of noncoaxial vortices in parametric wave mixing.
Sukhorukov, Anatoly P; Kalinovich, Alexey A; Molina-Terriza, Gabriel; Torner, Lluis
2002-09-01
In this paper we present a comprehensive study of the dynamics of screw phase dislocations under conditions of noncoaxial parametric three-wave mixing in the pump low-depletion regime. Under such conditions the signal and idler fields couple and so, the fields' properties change through propagation in the nonlinear crystal. We present an analytical model and a comprehensive study of the vortical features of the resulting field. The model is compared with the numerical solutions of the full equations. It is shown that by changing the relative amplitude and phase of the initial fields, one can control the domains where creation and annihilation of vortex-antivortex twins lead to different vortex content. We show that the effects studied here are relevant to a variety of physical systems. In particular, we show that the same phenomena are expected to occur in gyrotropic media and photonic crystals.
NASA Astrophysics Data System (ADS)
Zhou, Shengxi; Hobeck, Jared D.; Cao, Junyi; Inman, Daniel J.
2017-03-01
This paper makes a complete investigation of flexible longitudinal zigzag (FLZ) energy harvesters for the purpose of enhancing energy harvesting from low-frequency and low-amplitude excitation. A general theoretical model of the FLZ energy harvesters with large joint block mass is proposed. In order to verify the accuracy of the theoretical model, both experimental results and finite element analysis via ANSYS software are presented. Results show that the theoretical model can successfully predict the dynamic response and the output power of the FLZ energy harvesters. Both theoretical and experimental results demonstrate that the proposed energy harvesters can effectively harvest vibration energy even when the direction of excitation relative to the harvester varies from 0° to 90°. Under the low excitation level of 0.18 m s‑2, the experimental maximum output power of a FLZ energy harvester with five beams was found to be 1.016 mW. Finally, the results indicate that the proposed structure is capable of effective energy conversion across a large range of excitation angles at low-frequency and low-amplitude excitations, which makes it suitable for a wide range of working conditions.
Kinugawa, Tohru
2014-02-15
the isochronicity problem, there has been no attempt of N-type regions that are practically of full use for the charged-particle spectrometers and/or accelerators. In this Abel-transform approach, the superposition principle simplifies the derivation of X{sub A}(U) satisfying the extended isochronicity condition. Although the extended isochronicity condition inevitably discards the low-energy particles, there is no problem for handling accelerated particles because they do not involve the small-amplitude oscillations around the potential minimum. We present analytic examples of X{sub A}(U) that are instructive. In Appendix B, Urabe's criterion is interpreted in the time domain, using the Abel-transform approach.
NASA Astrophysics Data System (ADS)
Boatman, Elizabeth Marie
highly conserved in these four fossil specimens. Finally, the results of this study indicate that bioapatite can be preserved in even the most ancient vertebrate specimens, further supporting the idea that fossilization is a preservational process. This work also underlines the importance of using appropriately selected characterization and analytical techniques for the study of fossil bone, especially from the perspective of spatial resolution and the scale of the bone structural features in question.
Schenke, C.; Minguzzi, A.; Hekking, F. W. J.
2011-11-15
We consider a strongly interacting quasi-one-dimensional Bose gas on a tight ring trap subjected to a localized barrier potential. We explore the possibility of forming a macroscopic superposition of a rotating and a nonrotating state under nonequilibrium conditions, achieved by a sudden quench of the barrier velocity. Using an exact solution for the dynamical evolution in the impenetrable-boson (Tonks-Girardeau) limit, we find an expression for the many-body wave function corresponding to a superposition state. The superposition is formed when the barrier velocity is tuned close to multiples of an integer or half-integer number of Coriolis flux quanta. As a consequence of the strong interactions, we find that (i) the state of the system can be mapped onto a macroscopic superposition of two Fermi spheres rather than two macroscopically occupied single-particle states as in a weakly interacting gas, and (ii) the barrier velocity should be larger than the sound velocity to better discriminate the two components of the superposition.
NASA Astrophysics Data System (ADS)
Gharaee, H.; Rankin, R.; Marchand, R.; Paral, J.
2014-12-01
The ARTEMIS mission has made extensive measurements on the density and magnetic field structure of the lunar wake under different solar wind and magnetosphere conditions. Hybrid-kinetic simulations of the lunar wake have been found to be generally in good agreement with observations [Wiehle, S., et al., Planet. Space Sci., 2011], but are not readily available as they require access to large computers and human resources with expertise using this technology. It would be very useful to have an analytic model of the lunar wake, and one such model will be presented. It is based on an approach outlined by Hutchinson [Hutchinson, I., Physics Of Plasmas, 2008], and makes assumptions of cylindrical geometry, a strong and constant magnetic field, and fixed transverse velocity and temperature. Under these approximations the ion fluid equations (with massless electrons assumed) can be solved analytically by the method of characteristics. This paper demonstrates that the analytic model under these assumptions provides excellent agreement with observations and hybrid-kinetic simulations of the lunar wake. The approach outlined by Hutchinson is generalized to include an arbitrary angle between the interplanetary magnetic field and solar wind flow. This results in two angle-dependent characteristics for the fluid flow that can be solved for the density inside the wake region. The Density profiles for different orientations of magnetic field with respect to solar wind flow are in a good qualitative agreement with 2D Hybrid simulation results of the model developed by [Paral and Rankin, Nature Comms, 2012], and with ARTEMIS observations. Refrences, -Wiehle, S., et al. (2011), First Lunar wake passage of Artemis: Discrimination of wake effects and solar wind flactuations by 3D hybrid simulations, Planet. Space Sci., 59, 661-671, doi:10.1016/j.pss.2011.01.012. -Hutchinson, I. (2008),Oblique ion collection in the drift approximation:How magnetized Mach probes really work, Physics Of
NASA Astrophysics Data System (ADS)
Meštrić, H.; Eichel, R.-A.; Kloss, T.; Dinse, K.-P.; Laubach, So.; Laubach, St.; Schmidt, P. C.; Schönau, K. A.; Knapp, M.; Ehrenberg, H.
2005-04-01
The Fe3+ center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c axis. Its microscopic structure has been analyzed in detail comparing results from a semiempirical Newman superposition model analysis based on fine-structure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12K , exhibiting a c/a ratio of 1.0721.
Sze, Michelle Wynne C; Sugon, Quirino M; McNamara, Daniel J
2010-11-01
In this paper, we use Clifford (geometric) algebra Cl(3,0) to verify if electromagnetic energy-momentum density is still conserved for oblique superposition of two elliptically polarized plane waves with the same frequency. We show that energy-momentum conservation is valid at any time only for the superposition of two counter-propagating elliptically polarized plane waves. We show that the time-average energy-momentum of the superposition of two circularly polarized waves with opposite handedness is conserved regardless of the propagation directions of the waves. And, we show that the resulting momentum density of the superposed waves generally has a vector component perpendicular to the momentum densities of the individual waves.
Space-variant polarization patterns of non-collinear Poincaré superpositions
NASA Astrophysics Data System (ADS)
Galvez, E. J.; Beach, K.; Zeosky, J. J.; Khajavi, B.
2015-03-01
We present analysis and measurements of the polarization patterns produced by non-collinear superpositions of Laguerre-Gauss spatial modes in orthogonal polarization states, which are known as Poincaré modes. Our findings agree with predictions (I. Freund Opt. Lett. 35, 148-150 (2010)), that superpositions containing a C-point lead to a rotation of the polarization ellipse in 3-dimensions. Here we do imaging polarimetry of superpositions of first- and zero-order spatial modes at relative beam angles of 0-4 arcmin. We find Poincaré-type polarization patterns showing fringes in polarization orientation, but which preserve the polarization-singularity index for all three cases of C-points: lemons, stars and monstars.
Vala, Jiri; Kosloff, Ronnie; Amitay, Zohar; Zhang Bo; Leone, Stephen R.
2002-12-01
The Deutsch-Jozsa algorithm is experimentally demonstrated for three-qubit functions using pure coherent superpositions of Li{sub 2} rovibrational eigenstates. The function's character, either constant or balanced, is evaluated by first imprinting the function, using a phase-shaped femtosecond pulse, on a coherent superposition of the molecular states, and then projecting the superposition onto an ionic final state, using a second femtosecond pulse at a specific time delay.
NASA Astrophysics Data System (ADS)
Abolfathi, Ali; O'Boy, Dan J.; Walsh, Stephen J.; Fisher, Stephen A.
2017-01-01
It is well established that the dynamic response of a number of nominally identical built-up structures are often different and the variability increases with increasing complexity of the structure. Furthermore, the effects of the different parameters, for example the variation in joint locations or the range of the Young's modulus, on the dynamic response of the system are not the same. In this paper, the effects of different material and geometric parameters on the variability of a vibration transfer function are compared using an analytical model of a simple linear built-up structure that consist of two plates connected by a single mount. Similar results can be obtained if multiple mounts are used. The scope of this paper is limited to a low and medium frequency range where usually deterministic models are used for vibrational analysis. The effect of the mount position and also the global variation in the properties of the plate, such as modulus of elasticity or thickness, is higher on the variability of vibration transfer function than the effect of the mount properties. It is shown that the vibration transfer function between the plates is independent of the mount property if a stiff enough mount with a small mass is implemented. For a soft mount, there is a direct relationship between the mount impedance and the variation in the vibration transfer function. Furthermore, there are a range of mount stiffnesses between these two extreme cases at which the vibration transfer function is more sensitive to changes in the stiffness of the mount than when compared to a soft mount. It is found that the effect of variation in the mount damping and the mount mass on the variability is negligible. Similarly, the effect of the plate damping on the variability is not significant.
NASA Astrophysics Data System (ADS)
Pate, Brooks
2013-03-01
Advances in high-speed digital electronics have enabled a new generation of molecular rotational spectroscopy techniques that provide instantaneous broadband spectral coverage. These techniques use a chirped excitation pulse to coherently excite the molecular sample over a spectral bandwidth of 10 GHz or larger through rapid passage. The subsequent time-domain emission is recorded using high-speed digitizers (up to 100 Gigasample/s) and the frequency domain spectrum is produced by fast Fourier transformation. The chirped-pulse Fourier transform (CP-FT) method has been implemented in the microwave frequency range (2-40 GHz) for studies of cold samples in pulsed jet sources and in the mm-wave/terahertz (THz) frequency range for studies of samples at room-temperature. The method has opened new applications for molecular rotational spectroscopy in the area of chemical kinetics where dynamic rotational spectroscopy is used to measure the rates of unimolecular isomerization reactions in highly excited molecules prepared by pulsed infrared laser excitation. In these applications, the isomerization rate is obtained from an analysis of the overall line shapes which are modified by chemical exchange leading to coalescence behavior similar to the effect in NMR spectroscopy. The sensitivity of the method and the ability to extend it to low frequency (2-8 GHz) have significantly increased the size range of molecules and molecular clusters for structure determination using isotopic substitution to build up the 3D molecular structures atom-by-atom. Application to the structure of water clusters with up to 15 water molecules will be presented. When coupled with advances in solid-state mm-wave/THz devices, this method provides a direct digital technique for analytical chemistry of room-temperature gases based on molecular rotational spectroscopy. These high-throughput methods can analyze complex sample mixtures with unmatched chemical selectivity and short analysis times. Work
NASA Astrophysics Data System (ADS)
Gao, Yuanmei; Wen, Zengrun; Zheng, Liren; Zhao, Lina
2017-04-01
A method has been proposed to generate complex periodic discrete non-diffracting beams (PDNBs) via superposition of two identical simple PDNBs at a particular angle. As for special cases, we studied the superposition of the two identical squares (;4+4;) and two hexagonal (;6+6;) periodic wave fields at specific angles, respectively, and obtained a series of interesting complex PDNBs. New PDNBs were also obtained by modulating the initial phase difference between adjacent interfering beams. In the experiment, a 4 f Fourier filter system and a phase-only spatial light modulator imprinting synthesis phase patterns of these PDNBs were used to produce desired wave fields.
NASA Astrophysics Data System (ADS)
Daoud, M.; Ahl Laamara, R.
2012-07-01
We give the explicit expressions of the pairwise quantum correlations present in superpositions of multipartite coherent states. A special attention is devoted to the evaluation of the geometric quantum discord. The dynamics of quantum correlations under a dephasing channel is analyzed. A comparison of geometric measure of quantum discord with that of concurrence shows that quantum discord in multipartite coherent states is more resilient to dissipative environments than is quantum entanglement. To illustrate our results, we consider some special superpositions of Weyl-Heisenberg, SU(2) and SU(1,1) coherent states which interpolate between Werner and Greenberger-Horne-Zeilinger states.
NASA Astrophysics Data System (ADS)
Zhang, Pengjie
2011-03-01
We derive the exact analytical solution of the linear structure growth rate in ΛCDM cosmology with flat or curved geometry, under the Newtonian gauge. Unlike the well known solution under the Newtonian limit [D. J. Heath, Mon. Not. R. Astron. Soc. 179, 351 (1977)MNRAA40035-8711], our solution takes all general relativistic corrections into account and is hence valid at both the sub- and superhorizon scales. With this exact solution, we evaluate cosmological impacts induced by these relativistic corrections. (1) General relativistic corrections alter the density growth from z=100 to z=0 by 10% at k=0.01h/Mpc and the impact becomes stronger toward larger scales. We caution the readers that the overdensity is not gauge invariant and the above statement is restrained to the Newtonian gauge. (2) Relativistic corrections introduce a k-2 scale dependence in the density fluctuation. It mimics a primordial non-Gaussianity of the local type with fNLlocal˜1. This systematical error may become non-negligible for future all sky deep galaxy surveys. (3) Cosmological simulations with box size greater than 1 Gpc are also affected by these relativistic corrections. We provide a postprocessing recipe to correct for these effects. (4) These relativistic corrections affect the redshift distortion. However, at redshifts and scales relevant to redshift distortion measurements, such effect is negligible.
Dunst, Carl J; Trivette, Carol M
2009-01-01
Background. Family-centered care is now practiced throughout the world by physicians, nurses, and allied health care professionals. The call for adoption of family-centered care is based on the contention that the physical and psychological health of a child is influenced by parents' psychological health where family-centered care enhances parent well-being which in turn influences child well-being. We empirically assessed whether these relationships are supported by available evidence. Method. Meta-analytic structural equation modeling was used to test the direct and indirect influences of family-centered care and self-efficacy beliefs on parent and child psychological health. Data from more than 2900 parents and other caregivers in 15 studies were used for the analyses. Results. Family-centered care had indirect effects on parent and child psychological health mediated by self-efficacy beliefs. Conclusion. The relationships posited in the literature about family-centered care were supported by the study results.
Scalco, Andrea; Noventa, Stefano; Sartori, Riccardo; Ceschi, Andrea
2017-05-01
During the last decade, the purchase of organic food within a sustainable consumption context has gained momentum. Consequently, the amount of research in the field has increased, leading in some cases to discrepancies regarding both methods and results. The present review examines those works that applied the theory of planned behavior (TPB; Ajzen, 1991) as a theoretical framework in order to understand and predict consumers' motivation to buy organic food. A meta-analysis has been conducted to assess the strength of the relationships between attitude, subjective norms, perceived behavioral control, and intention, as well as between intention and behavior. Results confirm the major role played by individual attitude in shaping buying intention, followed by subjective norms and perceived behavioral control. Intention-behavior shows a large effect size, few studies however explicitly reported such an association. Furthermore, starting from a pooled correlation matrix, a meta-analytic structural equation model has been applied to jointly evaluate the strength of the relationships among the factors of the original model. Results suggest the robustness of the TPB model. In addition, mediation analysis indicates a potential direct effect from subjective norms to individual attitude in the present context. Finally, some issues regarding methodological aspects of the application of the TPB within the context of organic food are discussed for further research developments.
Shi, Lina; Pottier, Pierre; Skorobogatiy, Maksim; Peter, Yves-Alain
2009-06-22
Using finite-difference time-domain method, we characterize the normal-incidence transmission properties of a two slab photonic crystal device in a view of its applications in fluorescence enhancement and multi-analyte detection. Individual slabs consist of a square or a triangular lattice of air holes embedded into a silicon nitride slab. The geometrical parameters are chosen so that the individual slabs operate in a guided resonance regime where strong reflectivity under the normal incidence angle is observed in a broad spectral range. When placed in the close proximity of each other, the two photonic crystal slab system exhibits a narrow Fabry-Perot type transmission peak corresponding to the excitation of a resonant mode in the cavity formed by the two slabs. We then study the effects of the size of the air gap between the two photonic crystal slabs on the spectral position and bandwidth of a resonance transmission peak. Finally, we investigate the electromagnetic energy distributions at the wavelength of a transmission resonance in the double slab photonic crystals. As a final result we demonstrate that this structure can provide electric field enhancement at the slab surface, which can be used for fluorescence enhancement.
NASA Astrophysics Data System (ADS)
Brennan, Ryan; Pandya, Viraj; Somerville, Rachel S.; Barro, Guillermo; Bluck, Asa F. L.; Taylor, Edward N.; Wuyts, Stijn; Bell, Eric F.; Dekel, Avishai; Faber, Sandra; Ferguson, Henry C.; Koekemoer, Anton M.; Kurczynski, Peter; McIntosh, Daniel H.; Newman, Jeffrey A.; Primack, Joel
2017-02-01
We study the correlation of galaxy structural properties with their location relative to the SFR-M* correlation, also known as the star formation `star-forming main sequence' (SFMS), in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and Galaxy and Mass Assembly Survey and in a semi-analytic model (SAM) of galaxy formation. We first study the distribution of median Sérsic index, effective radius, star formation rate (SFR) density and stellar mass density in the SFR-M* plane. We then define a redshift-dependent main sequence and examine the medians of these quantities as a function of distance from this main sequence, both above (higher SFRs) and below (lower SFRs). Finally, we examine the distributions of distance from the main sequence in bins of these quantities. We find strong correlations between all of these galaxy structural properties and the distance from the SFMS, such that as we move from galaxies above the SFMS to those below it, we see a nearly monotonic trend towards higher median Sérsic index, smaller radius, lower SFR density, and higher stellar density. In the SAM, bulge growth is driven by mergers and disc instabilities, and is accompanied by the growth of a supermassive black hole which can regulate or quench star formation via active galactic nucleus feedback. We find that our model qualitatively reproduces the trends described above, supporting a picture in which black holes and bulges co-evolve, and active galactic nucleus feedback plays a critical role in moving galaxies off of the SFMS.
Generalization of susceptibility of RF systems through far-field pattern superposition
NASA Astrophysics Data System (ADS)
Verdin, B.; Debroux, P.
2015-05-01
The purpose of this paper is to perform an analysis of RF (Radio Frequency) communication systems in a large electromagnetic environment to identify its susceptibility to jamming systems. We propose a new method that incorporates the use of reciprocity and superposition of the far-field radiation pattern of the RF system and the far-field radiation pattern of the jammer system. By using this method we can find the susceptibility pattern of RF systems with respect to the elevation and azimuth angles. A scenario was modeled with HFSS (High Frequency Structural Simulator) where the radiation pattern of the jammer was simulated as a cylindrical horn antenna. The RF jamming entry point used was a half-wave dipole inside a cavity with apertures that approximates a land-mobile vehicle, the dipole approximates a leaky coax cable. Because of the limitation of the simulation method, electrically large electromagnetic environments cannot be quickly simulated using HFSS's finite element method (FEM). Therefore, the combination of the transmit antenna radiation pattern (horn) superimposed onto the receive antenna pattern (dipole) was performed in MATLAB. A 2D or 3D susceptibility pattern is obtained with respect to the azimuth and elevation angles. In addition, by incorporating the jamming equation into this algorithm, the received jamming power as a function of distance at the RF receiver Pr(Φr, θr) can be calculated. The received power depends on antenna properties, propagation factor and system losses. Test cases include: a cavity with four apertures, a cavity above an infinite ground plane, and a land-mobile vehicle approximation. By using the proposed algorithm a susceptibility analysis of RF systems in electromagnetic environments can be performed.
NASA Astrophysics Data System (ADS)
Kripal, Ram; Pandey, Sangita
2010-06-01
The electron paramagnetic resonance (EPR) studies are carried out on Cr 3+ ion doped ammonium dihydrogen phosphate (ADP) single crystals at room temperature. Four magnetically inequivalent sites for chromium are observed. No hyperfine structure is obtained. The crystal-field and spin Hamiltonian parameters are calculated from the resonance lines obtained at different angular rotations. The zero field and spin Hamiltonian parameters of Cr 3+ ion in ADP are calculated as: | D| = (257 ± 2) × 10 -4 cm -1, | E| = (79 ± 2) × 10 -4 cm -1, g = 1.9724 ± 0.0002 for site I; | D| = (257 ± 2) × 10 -4 cm -1, | E| = (77 ± 2) × 10 -4 cm -1, g = 1.9727 ± 0.0002 for site II; | D| = (259 ± 2) × 10 -4 cm -1, | E| = (78 ± 2) × 10 -4 cm -1, g = 1.9733 ± 0.0002 for site III; | D| = (259 ± 2) × 10 -4 cm -1, | E| = (77 ± 2) × 10 -4 cm -1, g = 1.973 ± 0.0002 for site IV, respectively. The site symmetry of Cr 3+ doped single crystal is discussed on the basis of EPR data. The Cr 3+ ion enters the lattice substitutionally replacing the NH 4+ sites. The optical absorption spectra are recorded in 195-925 nm wavelength range at room temperature. The energy values of different orbital levels are determined. On the basis of EPR and optical data, the nature of bonding in the crystal is discussed. The calculated values of Racah interelectronic repulsion parameters ( B and C), cubic crystal-field splitting parameter ( Dq) and nephelauxetic parameters ( h and k) are: B = 640, C = 3070, Dq = 2067 cm -1, h = 1.44 and k = 0.21, respectively. ZFS parameters are also determined using Bkq parameters from superposition model.
NASA Astrophysics Data System (ADS)
Calder, Julie A.; Wyatt, John A.; Frenkel, David A.; Casida, John E.
1993-02-01
Thirty-six compounds, representing six different structural classes of insecticides which are known to act at the γ-aminobutyric acid receptor/chloride ionophore, have been superimposed by methods which maximise the commonality of steric and electrostatic fields. Maximal steric and electrostatic alignment was derived by pairwise comparisons of the different chemical classes with picrotoxinin. To test the validity of the combined superposition, a Comparative Molecular Field Analysis (CoMFA) was carried out within SYBYL, using recently published in vivo and in vitro binding data for insecticides. The resultant partial least-squares (PLS) analysis of sampled steric and electrostatic fields showed a significant statistical correlation with the published biological data. The predictive model obtained was shown to have a greater than 95% chance of significance.
Application of time-temperature-stress superposition on creep of wood-plastic composites
NASA Astrophysics Data System (ADS)
Chang, Feng-Cheng; Lam, Frank; Kadla, John F.
2013-08-01
Time-temperature-stress superposition principle (TTSSP) was widely applied in studies of viscoelastic properties of materials. It involves shifting curves at various conditions to construct master curves. To extend the application of this principle, a temperature-stress hybrid shift factor and a modified Williams-Landel-Ferry (WLF) equation that incorporated variables of stress and temperature for the shift factor fitting were studied. A wood-plastic composite (WPC) was selected as the test subject to conduct a series of short-term creep tests. The results indicate that the WPC were rheologically simple materials and merely a horizontal shift was needed for the time-temperature superposition, whereas vertical shifting would be needed for time-stress superposition. The shift factor was independent of the stress for horizontal shifts in time-temperature superposition. In addition, the temperature- and stress-shift factors used to construct master curves were well fitted with the WLF equation. Furthermore, the parameters of the modified WLF equation were also successfully calibrated. The application of this method and equation can be extended to curve shifting that involves the effects of both temperature and stress simultaneously.
Using Musical Intervals to Demonstrate Superposition of Waves and Fourier Analysis
ERIC Educational Resources Information Center
LoPresto, Michael C.
2013-01-01
What follows is a description of a demonstration of superposition of waves and Fourier analysis using a set of four tuning forks mounted on resonance boxes and oscilloscope software to create, capture and analyze the waveforms and Fourier spectra of musical intervals.
NASA Astrophysics Data System (ADS)
Asjad, Muhammad; Vitali, David
2014-02-01
A deterministic scheme for generating a macroscopic superposition state of a nanomechanical resonator is proposed. The nonclassical state is generated through a suitably engineered dissipative dynamics exploiting the optomechanical quadratic interaction with a bichromatically driven optical cavity mode. The resulting driven dissipative dynamics can be employed for monitoring and testing the decoherence processes affecting the nanomechanical resonator under controlled conditions.
ERIC Educational Resources Information Center
Bowen, J. Philip; Sorensen, Jennifer B.; Kirschner, Karl N.
2007-01-01
The analysis explains the basis set superposition error (BSSE) and fragment relaxation involved in calculating the interaction energies using various first principle theories. Interacting the correlated fragment and increasing the size of the basis set can help in decreasing the BSSE to a great extent.
Chaos and Complexities Theories. Superposition and Standardized Testing: Are We Coming or Going?
ERIC Educational Resources Information Center
Erwin, Susan
2005-01-01
The purpose of this paper is to explore the possibility of using the principle of "superposition of states" (commonly illustrated by Schrodinger's Cat experiment) to understand the process of using standardized testing to measure a student's learning. Comparisons from literature, neuroscience, and Schema Theory will be used to expound upon the…
NASA Astrophysics Data System (ADS)
Lecamwasam, Ruvindha L.; Hush, Michael R.; James, Matthew R.; Carvalho, André R. R.
2017-01-01
We propose related schemes to generate arbitrarily shaped single photons, i.e., photons with an arbitrary temporal profile, and coherent state superpositions using simple optical elements. The first system consists of two coupled cavities, a memory cavity and a shutter cavity, containing a second-order optical nonlinearity and electro-optic modulator (EOM), respectively. Photodetection events of the shutter cavity output herald preparation of a single photon in the memory cavity, which may be stored by immediately changing the optical length of the shutter cavity with the EOM after detection. On-demand readout of the photon, with arbitrary shaping, can be achieved through modulation of the EOM. The second scheme consists of a memory cavity with two outputs, which are interfered, phase shifted, and measured. States that closely approximate a coherent state superposition can be produced through postselection for sequences of detection events, with more photon detection events leading to a larger superposition. We furthermore demonstrate that no-knowledge feedback can be easily implemented in this system and used to preserve the superposition state, as well as provide an extra control mechanism for state generation.
Merk, B.; Rohde, U.
2012-07-01
A new analytical method is described to deal with the Leakage Environmental Effect. The method is based on the analytical solution of the two-group diffusion equation for two adjacent fuel assemblies. The quality of the results for this highly efficient method is demonstrated for square fuel assemblies. In additional tests the transferability of the concept to hexagonal VVER-440-type fuel assemblies is shown and a comparison between the results for rectangular and hexagonal assemblies is given. (authors)
NASA Astrophysics Data System (ADS)
Milton, Graeme W.
2016-11-01
The theory of inhomogeneous analytic materials is developed. These are materials where the coefficients entering the equations involve analytic functions. Three types of analytic materials are identified. The first two types involve an integer p. If p takes its maximum value, then we have a complete analytic material. Otherwise, it is incomplete analytic material of rank p. For two-dimensional materials, further progress can be made in the identification of analytic materials by using the well-known fact that a 90° rotation applied to a divergence-free field in a simply connected domain yields a curl-free field, and this can then be expressed as the gradient of a potential. Other exact results for the fields in inhomogeneous media are reviewed. Also reviewed is the subject of metamaterials, as these materials provide a way of realizing desirable coefficients in the equations.
Milton, Graeme W
2016-11-01
The theory of inhomogeneous analytic materials is developed. These are materials where the coefficients entering the equations involve analytic functions. Three types of analytic materials are identified. The first two types involve an integer p. If p takes its maximum value, then we have a complete analytic material. Otherwise, it is incomplete analytic material of rank p. For two-dimensional materials, further progress can be made in the identification of analytic materials by using the well-known fact that a 90(°) rotation applied to a divergence-free field in a simply connected domain yields a curl-free field, and this can then be expressed as the gradient of a potential. Other exact results for the fields in inhomogeneous media are reviewed. Also reviewed is the subject of metamaterials, as these materials provide a way of realizing desirable coefficients in the equations.
NASA Astrophysics Data System (ADS)
Halder, P.; Chakraborty, A.; Deb Roy, P.; Das, H. S.
2014-09-01
In this paper, we report the development of a java application for the Superposition T-matrix code, JaSTA (Java Superposition T-matrix App), to study the light scattering properties of aggregate structures. It has been developed using Netbeans 7.1.2, which is a java integrated development environment (IDE). The JaSTA uses double precession superposition codes for multi-sphere clusters in random orientation developed by Mackowski and Mischenko (1996). It consists of a graphical user interface (GUI) in the front hand and a database of related data in the back hand. Both the interactive GUI and database package directly enable a user to model by self-monitoring respective input parameters (namely, wavelength, complex refractive indices, grain size, etc.) to study the related optical properties of cosmic dust (namely, extinction, polarization, etc.) instantly, i.e., with zero computational time. This increases the efficiency of the user. The database of JaSTA is now created for a few sets of input parameters with a plan to create a large database in future. This application also has an option where users can compile and run the scattering code directly for aggregates in GUI environment. The JaSTA aims to provide convenient and quicker data analysis of the optical properties which can be used in different fields like planetary science, atmospheric science, nano science, etc. The current version of this software is developed for the Linux and Windows platform to study the light scattering properties of small aggregates which will be extended for larger aggregates using parallel codes in future. Catalogue identifier: AETB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 571570 No. of bytes in distributed program
Brain-wave representation of words by superposition of a few sine waves
Suppes, Patrick; Han, Bing
2000-01-01
Data from three previous experiments were analyzed to test the hypothesis that brain waves of spoken or written words can be represented by the superposition of a few sine waves. First, we averaged the data over trials and a set of subjects, and, in one case, over experimental conditions as well. Next we applied a Fourier transform to the averaged data and selected those frequencies with high energy, in no case more than nine in number. The superpositions of these selected sine waves were taken as prototypes. The averaged unfiltered data were the test samples. The prototypes were used to classify the test samples according to a least-squares criterion of fit. The results were seven of seven correct classifications for the first experiment using only three frequencies, six of eight for the second experiment using nine frequencies, and eight of eight for the third experiment using five frequencies. PMID:10890906
Robot Behavior Acquisition Superposition and Composting of Behaviors Learned through Teleoperation
NASA Technical Reports Server (NTRS)
Peters, Richard Alan, II
2004-01-01
Superposition of a small set of behaviors, learned via teleoperation, can lead to robust completion of a simple articulated reach-and-grasp task. Results support the hypothesis that a set of learned behaviors can be combined to generate new behaviors of a similar type. This supports the hypothesis that a robot can learn to interact purposefully with its environment through a developmental acquisition of sensory-motor coordination. Teleoperation bootstraps the process by enabling the robot to observe its own sensory responses to actions that lead to specific outcomes. A reach-and-grasp task, learned by an articulated robot through a small number of teleoperated trials, can be performed autonomously with success in the face of significant variations in the environment and perturbations of the goal. Superpositioning was performed using the Verbs and Adverbs algorithm that was developed originally for the graphical animation of articulated characters. Work was performed on Robonaut at NASA-JSC.
Superposition and detection of two helical beams for optical orbital angular momentum communication
NASA Astrophysics Data System (ADS)
Liu, Yi-Dong; Gao, Chunqing; Gao, Mingwei; Qi, Xiaoqing; Weber, Horst
2008-07-01
A loop-like system with a Dove prism is used to generate a collinear superposition of two helical beams with different azimuthal quantum numbers in this manuscript. After the generation of the helical beams distributed on the circle centered at the optical axis by using a binary amplitude grating, the diffractive field is separated into two polarized ones with the same distribution. Rotated by the Dove prism in the loop-like system in counter directions and combined together, the two fields will generate the collinear superposition of two helical beams in certain direction. The experiment shows consistency with the theoretical analysis. This method has potential applications in optical communication by using orbital angular momentum of laser beams (optical vortices).
Brain-wave representation of words by superposition of a few sine waves.
Suppes, P; Han, B
2000-07-18
Data from three previous experiments were analyzed to test the hypothesis that brain waves of spoken or written words can be represented by the superposition of a few sine waves. First, we averaged the data over trials and a set of subjects, and, in one case, over experimental conditions as well. Next we applied a Fourier transform to the averaged data and selected those frequencies with high energy, in no case more than nine in number. The superpositions of these selected sine waves were taken as prototypes. The averaged unfiltered data were the test samples. The prototypes were used to classify the test samples according to a least-squares criterion of fit. The results were seven of seven correct classifications for the first experiment using only three frequencies, six of eight for the second experiment using nine frequencies, and eight of eight for the third experiment using five frequencies.
A numerical dressing method for the nonlinear superposition of solutions of the KdV equation
NASA Astrophysics Data System (ADS)
Trogdon, Thomas; Deconinck, Bernard
2014-01-01
In this paper we present the unification of two existing numerical methods for the construction of solutions of the Korteweg-de Vries (KdV) equation. The first method is used to solve the Cauchy initial-value problem on the line for rapidly decaying initial data. The second method is used to compute finite-genus solutions of the KdV equation. The combination of these numerical methods allows for the computation of exact solutions that are asymptotically (quasi-)periodic finite-gap solutions and are a nonlinear superposition of dispersive, soliton and (quasi-)periodic solutions in the finite (x, t)-plane. Such solutions are referred to as superposition solutions. We compute these solutions accurately for all values of x and t.
Generation of mesoscopic quantum superpositions through Kerr-stimulated degenerate downconversion
NASA Astrophysics Data System (ADS)
Paris, Matteo G. A.
1999-12-01
A two-step interaction scheme involving chi(2) and chi(3) nonlinear media is suggested for the generation of Schrödinger cat-like states of a single-mode optical field. In the first step, a weak coherent signal undergoes a self-Kerr phase modulation in a chi(3) crystal, leading to a Kerr kitten, namely a microscopic superposition of two coherent states with opposite phases. In the second step, such a Kerr kitten enters a chi(2) crystal and, in turn, plays the role of a quantum seed for stimulated phase-sensitive amplification. The output state in the above-threshold regime consists in a quantum superposition of mesoscopically distinguishable squeezed states, i.e. an optical cat-like state. The whole setup does not rely on conditional measurements, and is robust against decoherence, as only weak signals interact with the Kerr medium.
Fast superposition T-matrix solution for clusters with arbitrarily-shaped constituent particles
NASA Astrophysics Data System (ADS)
Markkanen, Johannes; Yuffa, Alex J.
2017-03-01
A fast superposition T-matrix solution is formulated for electromagnetic scattering by a collection of arbitrarily-shaped inhomogeneous particles. The T-matrices for individual constituents are computed by expanding the Green's dyadic in the spherical vector wave functions and formulating a volume integral equation, where the equivalent electric current is the unknown and the spherical vector wave functions are treated as excitations. Furthermore, the volume integral equation and the superposition T-matrix are accelerated by the precorrected-FFT algorithm and the fast multipole algorithm, respectively. The approach allows for an efficient scattering analysis of the clusters and aggregates consisting of a large number of arbitrarily-shaped inhomogeneous particles.
NASA Astrophysics Data System (ADS)
Tian, Si-Cong; Wan, Ren-Gang; Wang, Li-Jie; Shu, Shi-Li; Tong, Cun-Zhu; Wang, Li-Jun
2016-12-01
A scheme is proposed for coherent population transfer and creation of coherent superposition states assisted by one time-dependent tunneling pulse and one time-independent tunneling pulse in triple quantum dots. Time-dependent tunneling, which is similar to the Stokes laser pulse used in traditional stimulated Raman adiabatic passage, can lead to complete population transfer from the ground state to the indirect exciton states. Time-independent tunneling can also create double dark states, resulting in the distribution of the population and arbitrary coherent superposition states. Such a scheme can also be extended to multiple quantum dots assisted by one time-dependent tunneling pulse and more time-independent tunneling pulses.
Optical threshold secret sharing scheme based on basic vector operations and coherence superposition
NASA Astrophysics Data System (ADS)
Deng, Xiaopeng; Wen, Wei; Mi, Xianwu; Long, Xuewen
2015-04-01
We propose, to our knowledge for the first time, a simple optical algorithm for secret image sharing with the (2,n) threshold scheme based on basic vector operations and coherence superposition. The secret image to be shared is firstly divided into n shadow images by use of basic vector operations. In the reconstruction stage, the secret image can be retrieved by recording the intensity of the coherence superposition of any two shadow images. Compared with the published encryption techniques which focus narrowly on information encryption, the proposed method can realize information encryption as well as secret sharing, which further ensures the safety and integrality of the secret information and prevents power from being kept centralized and abused. The feasibility and effectiveness of the proposed method are demonstrated by numerical results.
Sanchez-Garcia, Manuel; Gardin, Isabelle; Lebtahi, Rachida; Dieudonné, Arnaud
2015-10-21
Two collapsed cone (CC) superposition algorithms have been implemented for radiopharmaceutical dosimetry of photon emitters. The straight CC (SCC) superposition method uses a water energy deposition kernel (EDKw) for each electron, positron and photon components, while the primary and scatter CC (PSCC) superposition method uses different EDKw for primary and once-scattered photons. PSCC was implemented only for photons originating from the nucleus, precluding its application to positron emitters. EDKw are linearly scaled by radiological distance, taking into account tissue density heterogeneities. The implementation was tested on 100, 300 and 600 keV mono-energetic photons and (18)F, (99m)Tc, (131)I and (177)Lu. The kernels were generated using the Monte Carlo codes MCNP and EGSnrc. The validation was performed on 6 phantoms representing interfaces between soft-tissues, lung and bone. The figures of merit were γ (3%, 3 mm) and γ (5%, 5 mm) criterions corresponding to the computation comparison on 80 absorbed doses (AD) points per phantom between Monte Carlo simulations and CC algorithms. PSCC gave better results than SCC for the lowest photon energy (100 keV). For the 3 isotopes computed with PSCC, the percentage of AD points satisfying the γ (5%, 5 mm) criterion was always over 99%. A still good but worse result was found with SCC, since at least 97% of AD-values verified the γ (5%, 5 mm) criterion, except a value of 57% for the (99m)Tc with the lung/bone interface. The CC superposition method for radiopharmaceutical dosimetry is a good alternative to Monte Carlo simulations while reducing computation complexity.
[Superposition impact character of air pollution from decentralization docks in a freshwater port].
Liu, Jian-chang; Li, Xing-hua; Xu, Hong-lei; Cheng, Jin-xiang; Wang, Zhong-dai; Xiao, Yang
2013-05-01
Air pollution from freshwater port is mainly caused by dust pollution, including material loading and unloading dust, road dust, and wind erosion dust from stockpile, bare soil. The dust pollution from a single dock characterized in obvious difference with air pollution from multiple scattered docks. Jining Port of Shandong Province was selected as a case study to get superposition impact contribution of air pollution for regional air environment from multiple scattered docks and to provide technical support for system evaluation of port air pollution. The results indicate that (1) the air pollution from freshwater port occupies a low proportion of pollution impact on regional environmental quality because the port is consisted of serveral small scattered docks; (2) however, the geometric center of the region distributed by docks is severely affected with the most superposition of the air pollution; and (3) the ADMS model is helpful to attain an effective and integrated assessment to predict a superposition impact of multiple non-point pollution sources when the differences of high-altitude weather conditions was not considered on a large scale.
Aerodynamic Analysis of the Truss-Braced Wing Aircraft Using Vortex-Lattice Superposition Approach
NASA Technical Reports Server (NTRS)
Ting, Eric Bi-Wen; Reynolds, Kevin Wayne; Nguyen, Nhan T.; Totah, Joseph J.
2014-01-01
The SUGAR Truss-BracedWing (TBW) aircraft concept is a Boeing-developed N+3 aircraft configuration funded by NASA ARMD FixedWing Project. This future generation transport aircraft concept is designed to be aerodynamically efficient by employing a high aspect ratio wing design. The aspect ratio of the TBW is on the order of 14 which is significantly greater than those of current generation transport aircraft. This paper presents a recent aerodynamic analysis of the TBW aircraft using a conceptual vortex-lattice aerodynamic tool VORLAX and an aerodynamic superposition approach. Based on the underlying linear potential flow theory, the principle of aerodynamic superposition is leveraged to deal with the complex aerodynamic configuration of the TBW. By decomposing the full configuration of the TBW into individual aerodynamic lifting components, the total aerodynamic characteristics of the full configuration can be estimated from the contributions of the individual components. The aerodynamic superposition approach shows excellent agreement with CFD results computed by FUN3D, USM3D, and STAR-CCM+.
Sagnac interferometry with coherent vortex superposition states in exciton-polariton condensates
NASA Astrophysics Data System (ADS)
Moxley, Frederick Ira; Dowling, Jonathan P.; Dai, Weizhong; Byrnes, Tim
2016-05-01
We investigate prospects of using counter-rotating vortex superposition states in nonequilibrium exciton-polariton Bose-Einstein condensates for the purposes of Sagnac interferometry. We first investigate the stability of vortex-antivortex superposition states, and show that they survive at steady state in a variety of configurations. Counter-rotating vortex superpositions are of potential interest to gyroscope and seismometer applications for detecting rotations. Methods of improving the sensitivity are investigated by targeting high momentum states via metastable condensation, and the application of periodic lattices. The sensitivity of the polariton gyroscope is compared to its optical and atomic counterparts. Due to the large interferometer areas in optical systems and small de Broglie wavelengths for atomic BECs, the sensitivity per detected photon is found to be considerably less for the polariton gyroscope than with competing methods. However, polariton gyroscopes have an advantage over atomic BECs in a high signal-to-noise ratio, and have other practical advantages such as room-temperature operation, area independence, and robust design. We estimate that the final sensitivities including signal-to-noise aspects are competitive with existing methods.
Role of the retinal detector array in perceiving the superposition effects of light
NASA Astrophysics Data System (ADS)
Roychoudhuri, Chandrasekhar; Lakshminarayanan, Vasudevan
2006-08-01
The perception of light in nature comes through the photopigment molecules of our retina. The objective of this paper is to relate our modern understanding of the quantum mechanical chemical processes in the retinal molecules with our observation of superposition ("interference") fringes due to multiple light beams. The issue of "interference" is important for two subtle reasons. First, we do not perceive light except though the response of the light detecting molecules. Second, EM fields do not operate on each other to create the "interference" (superposition) effects. When the intrinsic molecular properties of a detector allows it to respond simultaneously to all the superposed light beams on them, they sum the effects and report the corresponding "fringes" of superposition. In the human eye the "seeing" (or perception) is initiated by photo-isomerization of retinal, the chromophore of the opsin molecule. There exists several orders of magnitude difference between the characteristic times for the molecular processes of light absorption and the visual signal generation through the photochemical cascade. This allows us to function in the daily chores of walking and visual identification of objects and enjoy the beauty of the natural sceneries even though the retinal layer is bombarded simultaneously by innumerable beams of light with same and different frequencies, which will normally produce a flood of electronic "white noise" over a very wide range of temporal frequencies, namely the heterodyne beat signal. How do the eyes completely suppress this wide range of heterodyne beat signal?
Yi, Xingwen; Xu, Bo; Zhang, Jing; Lin, Yun; Qiu, Kun
2014-12-15
Digital coherent superposition (DCS) of optical OFDM subcarrier pairs with Hermitian symmetry can reduce the inter-carrier-interference (ICI) noise resulted from phase noise. In this paper, we show two different implementations of DCS-OFDM that have the same performance in the presence of laser phase noise. We complete the theoretical calculation on ICI reduction by using the model of pure Wiener phase noise. By Taylor expansion of the ICI, we show that the ICI power is cancelled to the second order by DCS. The fourth order term is further derived out and only decided by the ratio of laser linewidth to OFDM subcarrier symbol rate, which can greatly simplify the system design. Finally, we verify our theoretical calculations in simulations and use the analytical results to predict the system performance. DCS-OFDM is expected to be beneficial to certain optical fiber transmissions.
NASA Astrophysics Data System (ADS)
Hu, Xing-Biao; Bullough, Robin
1998-03-01
In this paper, the Caudrey-Dodd-Gibbon-Kotera-Sawada hierarchy in bilinear form is considered. A Bäcklund transformation for the CDGKS hierarchy is presented. Under certain conditions, the corresponding nonlinear superposition formula is proved.
NASA Astrophysics Data System (ADS)
Rosenfeld, Yaakov
1986-03-01
We study the analytic properties of the hypernetted-chain (HNC) and soft-mean-spherical (SMSA) theories in the asymptotic high-density limit (AHDL). The scaling properties of the inverse power potentials lead to the introduction of the SMSA-Ewald functions, which correspond to the ``overlap-volume'' functions for hard spheres. The HNC and SMSA theories for soft interactions, as well as the Percus-Yevick theory for hard spheres, feature the same AHDL analytic structure of the pair correlation functions, which is dictated by the hard-sphere Ewald functions. The general discussion is supplemented by detailed results for the one-component plasma. Implications to the analysis of the density-functional theory, of dense matter, near its exact Thomas-Fermi limit are pointed out.
NASA Astrophysics Data System (ADS)
He, Cenlin; Takano, Yoshi; Liou, Kuo-Nan; Yang, Ping; Li, Qinbin; Mackowski, Daniel W.
2016-11-01
We perform a comprehensive intercomparison of the geometric-optics surface-wave (GOS) approach, the superposition T-matrix method, and laboratory measurements for optical properties of fresh and coated/aged black carbon (BC) particles with complex structures. GOS and T-matrix calculations capture the measured optical (i.e., extinction, absorption, and scattering) cross sections of fresh BC aggregates, with 5-20% differences depending on particle size. We find that the T-matrix results tend to be lower than the measurements, due to uncertainty in theoretical approximations of realistic BC structures, particle property measurements, and numerical computations in the method. On the contrary, the GOS results are higher than the measurements (hence the T-matrix results) for BC radii <100 nm, because of computational uncertainty for small particles, while the discrepancy substantially reduces to 10% for radii >100 nm. We find good agreement (differences <5%) between the two methods in asymmetry factors for various BC sizes and aggregating structures. For aged BC particles coated with sulfuric acid, GOS and T-matrix results closely match laboratory measurements of optical cross sections. Sensitivity calculations show that differences between the two methods in optical cross sections vary with coating structures for radii <100 nm, while differences decrease to 10% for radii >100 nm. We find small deviations (≤10%) in asymmetry factors computed from the two methods for most BC coating structures and sizes, but several complex structures have 10-30% differences. This study provides the foundation for downstream application of the GOS approach in radiative transfer and climate studies.
Not Available
2006-06-01
In the Analytical Microscopy group, within the National Center for Photovoltaic's Measurements and Characterization Division, we combine two complementary areas of analytical microscopy--electron microscopy and proximal-probe techniques--and use a variety of state-of-the-art imaging and analytical tools. We also design and build custom instrumentation and develop novel techniques that provide unique capabilities for studying materials and devices. In our work, we collaborate with you to solve materials- and device-related R&D problems. This sheet summarizes the uses and features of four major tools: transmission electron microscopy, scanning electron microscopy, the dual-beam focused-ion-beam workstation, and scanning probe microscopy.
Leake, Stanley A.; Greer, William; Watt, Dennis; Weghorst, Paul
2008-01-01
According to the 'Law of the River', wells that draw water from the Colorado River by underground pumping need an entitlement for the diversion of water from the Colorado River. Consumptive use can occur through direct diversions of surface water, as well as through withdrawal of water from the river by underground pumping. To develop methods for evaluating the need for entitlements for Colorado River water, an assessment of possible depletion of water in the Colorado River by pumping wells is needed. Possible methods include simple analytical models and complex numerical ground-water flow models. For this study, an intermediate approach was taken that uses numerical superposition models with complex horizontal geometry, simple vertical geometry, and constant aquifer properties. The six areas modeled include larger extents of the previously defined river aquifer from the Lake Mead area to the Yuma area. For the modeled areas, a low estimate of transmissivity and an average estimate of transmissivity were derived from statistical analyses of transmissivity data. Aquifer storage coefficient, or specific yield, was selected on the basis of results of a previous study in the Yuma area. The USGS program MODFLOW-2000 (Harbaugh and others, 2000) was used with uniform 0.25-mile grid spacing along rows and columns. Calculations of depletion of river water by wells were made for a time of 100 years since the onset of pumping. A computer program was set up to run the models repeatedly, each time with a well in a different location. Maps were constructed for at least two transmissivity values for each of the modeled areas. The modeling results, based on the selected transmissivities, indicate that low values of depletion in 100 years occur mainly in parts of side valleys that are more than a few tens of miles from the Colorado River.
NASA Astrophysics Data System (ADS)
Khanpour, Hamzeh; Mirjalili, Abolfazl; Tehrani, S. Atashbar
2017-03-01
An analytical solution based on the Laplace transformation technique for the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations is presented at next-to-leading order accuracy in perturbative QCD. This technique is also applied to extract the analytical solution for the proton structure function, F2p(x ,Q2) , in the Laplace s space. We present the results for the separate parton distributions of all parton species, including valence quark densities, the antiquark and strange sea parton distribution functions (PDFs), and the gluon distribution. We successfully compare the obtained parton distribution functions and the proton structure function with the results from GJR08 [Gluck, Jimenez-Delgado, and Reya, Eur. Phys. J. C 53, 355 (2008)], 10.1140/epjc/s10052-007-0462-9 and KKT12 [Khanpour, Khorramian, and Tehrani, J. Phys. G 40, 045002 (2013)], 10.1088/0954-3899/40/4/045002 parametrization models as well as the x -space results using
NASA Astrophysics Data System (ADS)
Cai, Jianjun; Shen, Xueju; Lin, Chao
2016-01-01
We propose a security-enhanced asymmetric optical cryptosystem based on coherent superposition and equal modulus decomposition by combining full phase encryption technique with our previous cryptosystem. In the encryption process, the original image is phase encoded rather than bonded with a RPM. In the decryption process, two phase-contrast filters (PCFs) are employed to obtain the plaintext. As a consequence, the new cryptosystem guarantees high-level security to the attack based on iterative Fourier transform and maintains the good performance of our previous cryptosystem, especially conveniences. Some numerical simulations are presented to verify the validity and the performance of the modified cryptosystem.
NASA Astrophysics Data System (ADS)
Streltsov, Alexej I.; Alon, Ofir E.; Cederbaum, Lorenz S.
2009-10-01
Scattering in one dimension of an attractive ultracold bosonic cloud from a barrier can lead to the formation of two nonoverlapping clouds. Once formed, the clouds travel with constant velocity, in general different in magnitude from that of the incoming cloud, and do not disperse. The phenomenon and its mechanism—transformation of kinetic energy to internal energy of the scattered cloud—are obtained by solving the time-dependent many-boson Schrödinger equation. The analysis of the wave function shows that the object formed corresponds to a quantum superposition state of two distinct wave packets traveling through real space.
Effect of Superposition Location of Ultrasonic Fields on Sonochemical Reaction Rate
NASA Astrophysics Data System (ADS)
Yasuda, Keiji; Matsuura, Kazumasa
2013-07-01
The effect of the superposition location of ultrasonic fields on the sonochemical reaction rate was investigated using a sonochemical reactor with four transducers at 486 kHz. The transducers were attached at the bottom, upper side middle side, and lower side of a vessel. The reaction rate of potassium iodide in aqueous solution was measured. In the cases of the upper and bottom transducers, and the lower and bottom transducers, the synergy effect of sonochemical efficiency was observed. The amount of synergy effect for the upper and bottom transducers increased with increasing electric power.
Alishahi, Fatemeh; Mehrany, Khashayar
2010-06-01
We analytically relate the giant Goos-Hänchen shift, observed at the interface of a high refractive index prism and a waveguide structure with an arbitrary refractive index profile, to the spatial resonance phenomenon. The proximity effect of the high refractive index prism on modal properties of the waveguide is discussed, and the observed shift is expressed in terms of proper and improper electromagnetic modes supported by the waveguide with no prism. The transversely increasing improper modes are shown playing an increasingly important role as the high refractive index prism comes closer to the waveguide.
NASA Astrophysics Data System (ADS)
Richard, Ryan M.; Herbert, John M.
2013-06-01
Previous electronic structure studies that have relied on fragmentation have been primarily interested in those methods' abilities to replicate the supersystem energy (or a related energy difference) without recourse to the ability of those supersystem results to replicate experiment or high accuracy benchmarks. Here we focus on replicating accurate ab initio benchmarks, that are suitable for comparison to experimental data. In doing this it becomes imperative that we correct our methods for basis-set superposition errors (BSSE) in a computationally feasible way. This criterion leads us to develop a new method for BSSE correction, which we term the many-body counterpoise correction, or MBn for short. MBn is truncated at order n, in much the same manner as a normal many-body expansion leading to a decrease in computational time. Furthermore, its formulation in terms of fragments makes it especially suitable for use with pre-existing fragment codes. A secondary focus of this study is directed at assessing fragment methods' abilities to extrapolate to the complete basis set (CBS) limit as well as compute approximate triples corrections. Ultimately, by analysis of (H_2O)_6 and (H_2O)_{10}F^- systems, it is concluded that with large enough basis-sets (triple or quad zeta) fragment based methods can replicate high level benchmarks in a fraction of the time.
Brainerd, C. J.; Wang, Zheng; Reyna, Valerie. F.; Nakamura, K.
2015-01-01
Fuzzy-trace theory’s assumptions about memory representation are cognitive examples of the familiar superposition property of physical quantum systems. When those assumptions are implemented in a formal quantum model (QEMc), they predict that episodic memory will violate the additive law of probability: If memory is tested for a partition of an item’s possible episodic states, the individual probabilities of remembering the item as belonging to each state must sum to more than 1. We detected this phenomenon using two standard designs, item false memory and source false memory. The quantum implementation of fuzzy-trace theory also predicts that violations of the additive law will vary in strength as a function of reliance on gist memory. That prediction, too, was confirmed via a series of manipulations (e.g., semantic relatedness, testing delay) that are thought to increase gist reliance. Surprisingly, an analysis of the underlying structure of violations of the additive law revealed that as a general rule, increases in remembering correct episodic states do not produce commensurate reductions in remembering incorrect states. PMID:26236091
NASA Astrophysics Data System (ADS)
Mahadev, Sthanu
Continued research and development efforts devoted in recent years have generated novel avenues towards the advancement of efficient and effective, slender laminated fiber-reinforced composite members. Numerous studies have focused on the modeling and response characterization of composite structures with particular relevance to thin-walled cylindrical composite shells. This class of shell configurations is being actively explored to fully determine their mechanical efficacy as primary aerospace structural members. The proposed research is targeted towards formulating a composite shell theory based prognosis methodology that entails an elaborate analysis and investigation of thin-walled cylindrical shell type laminated composite configurations that are highly desirable in increasing number of mechanical and aerospace applications. The prime motivation to adopt this theory arises from its superior ability to generate simple yet viable closed-form analytical solution procedure to numerous geometrically intense, inherent curvature possessing composite structures. This analytical evaluative routine offers to acquire a first-hand insight on the primary mechanical characteristics that essentially govern the behavior of slender composite shells under typical static loading conditions. Current work exposes the robustness of this mathematical framework via demonstrating its potential towards the prediction of structural properties such as axial stiffness and bending stiffness respectively. Longitudinal ply-stress computations are investigated upon deriving the global stiffness matrix model for composite cylindrical tubes with circular cross-sections. Additionally, this work employs a finite element based numerical technique to substantiate the analytical results reported for cylindrically shaped circular composite tubes. Furthermore, this concept development is extended to the study of thin-walled, open cross-sectioned, curved laminated shells that are geometrically
Zhang, Xiao-Zheng; Thomas, Jean-Hugh; Bi, Chuan-Xing; Pascal, Jean-Claude
2012-10-01
A time-domain plane wave superposition method is proposed to reconstruct nonstationary sound fields. In this method, the sound field is expressed as a superposition of time convolutions between the estimated time-wavenumber spectrum of the sound pressure on a virtual source plane and the time-domain propagation kernel at each wavenumber. By discretizing the time convolutions directly, the reconstruction can be carried out iteratively in the time domain, thus providing the advantage of continuously reconstructing time-dependent pressure signals. In the reconstruction process, the Tikhonov regularization is introduced at each time step to obtain a relevant estimate of the time-wavenumber spectrum on the virtual source plane. Because the double infinite integral of the two-dimensional spatial Fourier transform is discretized directly in the wavenumber domain in the proposed method, it does not need to perform the two-dimensional spatial fast Fourier transform that is generally used in time domain holography and real-time near-field acoustic holography, and therefore it avoids some errors associated with the two-dimensional spatial fast Fourier transform in theory and makes possible to use an irregular microphone array. The feasibility of the proposed method is demonstrated by numerical simulations and an experiment with two speakers.
Noise-based logic: Binary, multi-valued, or fuzzy, with optional superposition of logic states
NASA Astrophysics Data System (ADS)
Kish, Laszlo B.
2009-03-01
A new type of deterministic (non-probabilistic) computer logic system inspired by the stochasticity of brain signals is shown. The distinct values are represented by independent stochastic processes: independent voltage (or current) noises. The orthogonality of these processes provides a natural way to construct binary or multi-valued logic circuitry with arbitrary number N of logic values by using analog circuitry. Moreover, the logic values on a single wire can be made a (weighted) superposition of the N distinct logic values. Fuzzy logic is also naturally represented by a two-component superposition within the binary case ( N=2). Error propagation and accumulation are suppressed. Other relevant advantages are reduced energy dissipation and leakage current problems, and robustness against circuit noise and background noises such as 1/f, Johnson, shot and crosstalk noise. Variability problems are also non-existent because the logic value is an AC signal. A similar logic system can be built with orthogonal sinusoidal signals (different frequency or orthogonal phase) however that has an extra 1/N type slowdown compared to the noise-based logic system with increasing number of N furthermore it is less robust against time delay effects than the noise-based counterpart.
Generation of mesoscopic quantum superpositions through Kerr-stimulated degenerate downconversion
NASA Astrophysics Data System (ADS)
Paris, Matteo G. A.
1999-12-01
A two-step interaction scheme involving icons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/>(2) and icons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/>(3) nonlinear media is suggested for the generation of Schrödinger cat-like states of a single-mode optical field. In the first step, a weak coherent signal undergoes a self-Kerr phase modulation in a icons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/>(3) crystal, leading to a Kerr kitten, namely a microscopic superposition of two coherent states with opposite phases. In the second step, such a Kerr kitten enters a icons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/>(2) crystal and, in turn, plays the role of a quantum seed for stimulated phase-sensitive amplification. The output state in the above-threshold regime consists in a quantum superposition of mesoscopically distinguishable squeezed states, i.e. an optical cat-like state. The whole setup does not rely on conditional measurements, and is robust against decoherence, as only weak signals interact with the Kerr medium.
Roessl, Ulrich; Leitgeb, Stefan; Pieters, Sigrid; De Beer, Thomas; Nidetzky, Bernd
2014-08-01
A Raman spectroscopy-based method for in situ monitoring of secondary structural composition of proteins during frozen and thawed storage was developed. A set of reference proteins with different α-helix and β-sheet compositions was used for calibration and validation in a chemometric approach. Reference secondary structures were quantified with circular dichroism spectroscopy in the liquid state. Partial least squares regression models were established that enable estimation of secondary structure content from Raman spectra. Quantitative secondary structure determination in ice was accomplished for the first time and correlation with existing (qualitative) protein structural data from the frozen state was achieved. The method can be used in the presence of common stabilizing agents and is applicable in an industrial freezer setup. Raman spectroscopy represents a powerful, noninvasive, and flexibly applicable tool for protein stability monitoring during frozen storage.
NASA Astrophysics Data System (ADS)
Ben Slimane, Mourad; Ben Mabrouk, Anouar; Aouidi, Jamil
2016-08-01
Mixed multifractal analysis for functions studies the Hölder pointwise behavior of more than one single function. For a vector F = (f1,…,fL) of L functions, with L ≥ 2, we are interested in the mixed Hölder spectrum, which is the Hausdorff dimension of the set of points for which each function fl has exactly a given value αl of pointwise Hölder regularity. We will conjecture a formula which relates the mixed Hölder spectrum to some mixed averaged wavelet quantities of F. We will prove an upper bound valid for any vector of uniform Hölder functions. Then we will prove the validity of the conjecture for self-similar vectors of functions, quasi-self-similar vectors and their superpositions. These functions are written as the superposition of similar structures at different scales, reminiscent of some possible modelization of turbulence or cascade models. Their expressions look also like wavelet decompositions.
NASA Astrophysics Data System (ADS)
Loyau, V.; Aubert, A.; LoBue, M.; Mazaleyrat, F.
2017-03-01
In this paper, we investigate the demagnetizing effect in ferrite/PZT/ferrite magnetoelectric (ME) trilayer composites consisting of commercial PZT discs bonded by epoxy layers to Ni-Co-Zn ferrite discs made by a reactive Spark Plasma Sintering (SPS) technique. ME voltage coefficients (transversal mode) were measured on ferrite/PZT/ferrite trilayer ME samples with different thicknesses or phase volume ratio in order to highlight the influence of the magnetic field penetration governed by these geometrical parameters. Experimental ME coefficients and voltages were compared to analytical calculations using a quasi-static model. Theoretical demagnetizing factors of two magnetic discs that interact together in parallel magnetic structures were derived from an analytical calculation based on a superposition method. These factors were introduced in ME voltage calculations which take account of the demagnetizing effect. To fit the experimental results, a mechanical coupling factor was also introduced in the theoretical formula. This reflects the differential strain that exists in the ferrite and PZT layers due to shear effects near the edge of the ME samples and within the bonding epoxy layers. From this study, an optimization in magnitude of the ME voltage is obtained. Lastly, an analytical calculation of demagnetizing effect was conducted for layered ME composites containing higher numbers of alternated layers (n ≥ 5). The advantage of such a structure is then discussed.
NASA Astrophysics Data System (ADS)
Huang, Ching-Sheng; Yeh, Hund-Der
2016-11-01
This study introduces an analytical approach to estimate drawdown induced by well extraction in a heterogeneous confined aquifer with an irregular outer boundary. The aquifer domain is divided into a number of zones according to the zonation method for representing the spatial distribution of a hydraulic parameter field. The lateral boundary of the aquifer can be considered under the Dirichlet, Neumann or Robin condition at different parts of the boundary. Flow across the interface between two zones satisfies the continuities of drawdown and flux. Source points, each of which has an unknown volumetric rate representing the boundary effect on the drawdown, are allocated around the boundary of each zone. The solution of drawdown in each zone is expressed as a series in terms of the Theis equation with unknown volumetric rates from the source points. The rates are then determined based on the aquifer boundary conditions and the continuity requirements. The estimated aquifer drawdown by the present approach agrees well with a finite element solution developed based on the Mathematica function NDSolve. As compared with the existing numerical approaches, the present approach has a merit of directly computing the drawdown at any given location and time and therefore takes much less computing time to obtain the required results in engineering applications.
Graded-Index Optics are Matched to Optical Geometry in the Superposition Eyes of Scarab Beetles
NASA Astrophysics Data System (ADS)
McIntyre, P.; Caveney, S.
1985-11-01
Detailed measurements were made of the gradients of refractive index (g.r.i.) and relevant optical properties of the lens components in the ventral superposition eyes of three crepuscular species of the dung-beetle genus Onitis (Scarabaeinae). Each ommatidial lens has two components, a corneal facet and a crystalline cone; in both of these, the gradients provide a significant proportion of the refractive power. The spatial relationship between the lenses and the retina (optical geometry) was also determined. A computer ray-trace model based on these data was used to analyse the optical properties of the lenses and of the eye as a whole. Ray traces were done in two and three dimensions. The ommatidial lenses in all three species are afocal g.r.i. telescopes of low angular magnification. Parallel incident rays emerge approximately parallel for all angles of incidence up to the maximum. The superposition image of a distant point source is a small patch of light about the size of a rhabdom. There are obvious differences in the lens properties of the three species, most significantly in the shape of the refractive-index gradients in the crystalline cone, in the extent of the g.r.i. region in the two lens components and in the front-surface curvature of the corneal facet lens. These give rise to different angular magnifications M of the ommatidial lenses, the values for the three species being 1.7, 1.3, 1.0. This variation in M is matched by a variation in optical geometry, most evident in the different clear-zone widths. As a result, the level of the best superposition image lies close to the retina in the model eyes of all three species. The angular magnification also sets the maximum aperture or pupil of the eye and hence the brightness of the image on the retina. The smaller M, the larger the aperture and the brighter the image. By adopting a suitable value for M and the appropriate eye geometry, an eye can set image brightness and hence sensitivity within a certain
Goodman, Michael L.
2011-04-10
A Harris sheet magnetic field with maximum magnitude B{sub 0} and length scale L is combined with the anisotropic electrical conductivity, viscosity, and thermoelectric tensors for an electron-proton plasma to define a magnetohydrodynamic model that determines the steady state of the plasma. The transport tensors are functions of temperature, density, and magnetic field strength, and are computed self-consistently as functions of position x normal to the current sheet. The flow velocity, magnetic field, and gravitational force lie along the z-axis. The plasma is supported against gravity by the viscous force. Analytic solutions are obtained for temperature, density, and velocity. They are valid over a broad range of temperature, density, and magnetic field strength, and so may be generally useful in astrophysical applications. Numerical examples of solutions in the parameter range of the solar atmosphere are presented. The objective is to compare Joule and viscous heating rates, determine the velocity shear that generates viscous forces that support the plasma and are self-consistent with a mean outward mass flux comparable to the solar wind mass flux, and compare the thermoelectric and conduction current contributions to the Joule heating rate. The ratio of the viscous to Joule heating rates per unit mass can exceed unity by orders of magnitude, and increases rapidly with L. The viscous heating rate can be concentrated outside the region where the current density is localized, corresponding to a resistively heated layer of plasma bounded by viscously heated plasma. The temperature gradient drives a thermoelectric current density that can have a magnitude greater than that of the electric-field-driven conduction current density, so thermoelectric effects are important in determining the Joule heating rate.
ERIC Educational Resources Information Center
Piaget, Jean
Provided is an overview of the analytical method known as structuralism. The first chapter discusses the three key components of the concept of a structure: the view of a system as a whole instead of so many parts; the study of the transformations in the system; and the fact that these transformations never lead beyond the system but always…
ERIC Educational Resources Information Center
Friedman-Weieneth, Julie L.; Doctoroff, Greta L.; Harvey, Elizabeth A.; Goldstein, Lauren H.
2009-01-01
Objective: Despite recognition that disruptive behavior disorders often begin early in development, existing assessment tools are largely based on research with school-aged children. Further empirical work is needed to evaluate the utility of these tools in younger children. Methods: The present study investigated the factor structure, internal…
ERIC Educational Resources Information Center
Frazier, Thomas W.; Ratliff, Kristin R.; Gruber, Chris; Zhang, Yi; Law, Paul A.; Constantino, John N.
2014-01-01
Understanding the factor structure of autistic symptomatology is critical to the discovery and interpretation of causal mechanisms in autism spectrum disorder. We applied confirmatory factor analysis and assessment of measurement invariance to a large ("N" = 9635) accumulated collection of reports on quantitative autistic traits using…
NASA Astrophysics Data System (ADS)
Blecha, L.; Zindel, D.; Cottard, H.; Beck, T.; Cessa, V.; Broeg, C.; Ratti, F.; Rando, N.
2016-07-01
The CHEOPS (CHaracterising ExOPlanet Satellite), which is an ESA mission developed in cooperation with Switzerland and a number of other member-states, is the first one dedicated to search for transits by means of ultrahigh precision photometry on bright stars already known to host planets. The optical design is based on a Ritchey-Chretien style telescope to provide a de-focussed image of the target stars. The telescope's mirrors M1, M2 as well as the focal plane detector are supported by a thermally controlled CFRP structure suspended on isostatic mounts. The dimensional stability of the structural system supporting the optics is a key requirement as it directly impacts the instrument's accuracy. The M1 and M2 mirrors are supported by a tubular CFRP telescope design which has been optimized by analyses down to carbon fibre layer level with the support of extensive sample test results for model correlation and accurate dimensional stability predictions. This sample characterization test campaign has been conducted on samples with different carbon fibre layups (orientation and stack sequence) to measure accurately the Coefficient of Thermal Expansion (CTE) over a wide temperature range extending from -80°C to +80°C. Using the correlated Finite Element Model, the fibre orientation layup that minimized the relative displacement between the M1 and M2 mirrors, including the consideration of the thermo-elastic contributions of the isostatic mounts on the overall stability of this optical system, has been identified and selected for the baseline design of the CHEOPS Structure. A dedicated Structural and Thermal Model (STM2), which was then refurbished to a PFM, was manufactured and tested with an ad hoc setup to verify the overall structural stability of the optical train assembly [2]. The relative distance between M1 and M2 was measured under thermal vacuum conditions using laser interferometer techniques. Thermal cycling tests were initially conducted to eliminate and
NASA Astrophysics Data System (ADS)
McCarty, J.; Clark, A. J.; Copperman, J.; Guenza, M. G.
2014-05-01
Structural and thermodynamic consistency of coarse-graining models across multiple length scales is essential for the predictive role of multi-scale modeling and molecular dynamic simulations that use mesoscale descriptions. Our approach is a coarse-grained model based on integral equation theory, which can represent polymer chains at variable levels of chemical details. The model is analytical and depends on molecular and thermodynamic parameters of the system under study, as well as on the direct correlation function in the k → 0 limit, c0. A numerical solution to the PRISM integral equations is used to determine c0, by adjusting the value of the effective hard sphere diameter, dHS, to agree with the predicted equation of state. This single quantity parameterizes the coarse-grained potential, which is used to perform mesoscale simulations that are directly compared with atomistic-level simulations of the same system. We test our coarse-graining formalism by comparing structural correlations, isothermal compressibility, equation of state, Helmholtz and Gibbs free energies, and potential energy and entropy using both united atom and coarse-grained descriptions. We find quantitative agreement between the analytical formalism for the thermodynamic properties, and the results of Molecular Dynamics simulations, independent of the chosen level of representation. In the mesoscale description, the potential energy of the soft-particle interaction becomes a free energy in the coarse-grained coordinates which preserves the excess free energy from an ideal gas across all levels of description. The structural consistency between the united-atom and mesoscale descriptions means the relative entropy between descriptions has been minimized without any variational optimization parameters. The approach is general and applicable to any polymeric system in different thermodynamic conditions.
McCarty, J.; Clark, A. J.; Copperman, J.; Guenza, M. G.
2014-05-28
Structural and thermodynamic consistency of coarse-graining models across multiple length scales is essential for the predictive role of multi-scale modeling and molecular dynamic simulations that use mesoscale descriptions. Our approach is a coarse-grained model based on integral equation theory, which can represent polymer chains at variable levels of chemical details. The model is analytical and depends on molecular and thermodynamic parameters of the system under study, as well as on the direct correlation function in the k → 0 limit, c{sub 0}. A numerical solution to the PRISM integral equations is used to determine c{sub 0}, by adjusting the value of the effective hard sphere diameter, d{sub HS}, to agree with the predicted equation of state. This single quantity parameterizes the coarse-grained potential, which is used to perform mesoscale simulations that are directly compared with atomistic-level simulations of the same system. We test our coarse-graining formalism by comparing structural correlations, isothermal compressibility, equation of state, Helmholtz and Gibbs free energies, and potential energy and entropy using both united atom and coarse-grained descriptions. We find quantitative agreement between the analytical formalism for the thermodynamic properties, and the results of Molecular Dynamics simulations, independent of the chosen level of representation. In the mesoscale description, the potential energy of the soft-particle interaction becomes a free energy in the coarse-grained coordinates which preserves the excess free energy from an ideal gas across all levels of description. The structural consistency between the united-atom and mesoscale descriptions means the relative entropy between descriptions has been minimized without any variational optimization parameters. The approach is general and applicable to any polymeric system in different thermodynamic conditions.
NASA Astrophysics Data System (ADS)
Wang, Xiaogang; Zhao, Daomu
2012-10-01
We propose an optoelectronic image encryption and decryption technique based on coherent superposition principle and digital holography. With the help of a chaotic random phase mask (CRPM) that is generated by using logistic map, a real-valued primary image is encoded into a phase-only version and then recorded as an encoded hologram. As for multiple-image encryption, only one digital hologram is to be transmitted as the encrypted result by using the multiplexing technique changing the reference wave angle. The bifurcation parameters, the initial values for the logistic maps, the number of the removed elements and the reference wave parameters are kept and transmitted as private keys. Both the encryption and decryption processes can be implemented in opto-digital manner or fully digital manner. Simulation results are given for testing the feasibility of the proposed approach.
NASA Astrophysics Data System (ADS)
Yang, Xiao-Dong; Chen, Li-Qun
2006-01-01
Stability in transverse parametric vibration of axially accelerating viscoelastic beams is investigated. The governing equation is derived from Newton's second law, Boltzmann's superposition principle, and the geometrical relation. When the axial speed is a constant mean speed with small harmonic variations, the governing equation can be treated as a continuous gyroscopic system with small periodically parametric excitations and a damping term. The method of multiple scales is applied directly to the governing equation without discretization. The stability conditions are obtained for combination and principal parametric resonance. Numerical examples demonstrate that the increase of the viscosity coefficient causes the lager instability threshold of speed fluctuation amplitude for given detuning parameter and smaller instability range of the detuning parameter for given speed fluctuation amplitude. The instability region is much bigger in lower order principal resonance than that in the higher order.
Nonlocal quantum macroscopic superposition in a high-thermal low-purity state.
Brezinski, Mark E; Liu, Bin
2008-12-16
Quantum state exchange between light and matter is an important ingredient for future quantum information networks as well as other applications. Photons are the fastest and simplest carriers of information for transmission but in general, it is difficult to localize and store photons, so usually one prefers choosing matter as quantum memory elements. Macroscopic superposition and nonlocal quantum interactions have received considerable interest for this purpose over recent years in fields ranging from quantum computers to cryptography, in addition to providing major insights into physical laws. However, these experiments are generally performed either with equipment or under conditions that are unrealistic for practical applications. Ideally, the two can be combined using conventional equipment and conditions to generate a "quantum teleportation"-like state, particularly with a very small amount of purity existing in an overall highly mixed thermal state (relatively low decoherence at high temperatures). In this study we used an experimental design to demonstrate these principles. We performed optical coherence tomography (OCT) using a thermal source at room temperatures of a specifically designed target in the sample arm. Here, position uncertainty (i.e., dispersion) was induced in the reference arm. In the sample arm (target) we placed two glass plates separated by a different medium while altering position uncertainty in the reference arm. This resulted in a chirped signal between the glass plate reflective surfaces in the combined interferogram. The chirping frequency, as measured by the fast Fourier transform (FFT), varies with the medium between the plates, which is a nonclassical phenomenon. These results are statistically significant and occur from a superposition between the glass surface and the medium with increasing position uncertainty, a true quantum-mechanical phenomenon produced by photon pressure from two-photon interference. The differences in
NASA Astrophysics Data System (ADS)
Carlisle, Andrew; Kwon, Hyukjoon; Jeong, Hyunseok; Ferraro, Alessandro; Paternostro, Mauro
2015-08-01
Optomechanics is currently believed to provide a promising route towards the achievement of genuine quantum effects at the large, massive-system scale. By using a recently proposed figure of merit that is well suited to address continuous-variable systems, in this paper we analyze the requirements needed for the state of a mechanical mode (embodied by an end-cavity cantilever or a membrane placed within an optical cavity) to be qualified as macroscopic. We show that according to the phase-space-based criterion that we have chosen for our quantitative analysis, the state achieved through strong single-photon radiation-pressure coupling to a quantized field of light and conditioned by measurements operated on the latter might be interpreted as macroscopically quantum. In general, though, genuine macroscopic quantum superpositions appear to be possible only under quite demanding experimental conditions.
Yi, Xingwen; Chen, Xuemei; Sharma, Dinesh; Li, Chao; Luo, Ming; Yang, Qi; Li, Zhaohui; Qiu, Kun
2014-06-02
Digital coherent superposition (DCS) provides an approach to combat fiber nonlinearities by trading off the spectrum efficiency. In analogy, we extend the concept of DCS to the optical OFDM subcarrier pairs with Hermitian symmetry to combat the linear and nonlinear phase noise. At the transmitter, we simply use a real-valued OFDM signal to drive a Mach-Zehnder (MZ) intensity modulator biased at the null point and the so-generated OFDM signal is Hermitian in the frequency domain. At receiver, after the conventional OFDM signal processing, we conduct DCS of the optical OFDM subcarrier pairs, which requires only conjugation and summation. We show that the inter-carrier-interference (ICI) due to phase noise can be reduced because of the Hermitain symmetry. In a simulation, this method improves the tolerance to the laser phase noise. In a nonlinear WDM transmission experiment, this method also achieves better performance under the influence of cross phase modulation (XPM).
Lee, Su-Yong; Kim, Ho-Joon; Ji, Se-Wan; Nha, Hyunchul
2011-07-15
We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation ta+ra{sup {dagger}} of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the Einstein-Podolsky-Rosen-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction a and the addition a{sup {dagger}} particularly in the small-squeezing regime, whereas the optimal operation becomes the photon subtraction (case of r=0) in the large-squeezing regime.
NASA Astrophysics Data System (ADS)
Matsuo, Miyuki; Yokoyama, Misao; Umemura, Kenji; Gril, Joseph; Yano, Ken'ichiro; Kawai, Shuichi
2010-04-01
This paper deals with the kinetics of the color properties of hinoki ( Chamaecyparis obtusa Endl.) wood. Specimens cut from the wood were heated at 90-180°C as accelerated aging treatment. The specimens completely dried and heated in the presence of oxygen allowed us to evaluate the effects of thermal oxidation on wood color change. Color properties measured by a spectrophotometer showed similar behavior irrespective of the treatment temperature with each time scale. Kinetic analysis using the time-temperature superposition principle, which uses the whole data set, was successfully applied to the color changes. The calculated values of the apparent activation energy in terms of L *, a *, b *, and Δ E^{*}_{ab} were 117, 95, 114, and 113 kJ/mol, respectively, which are similar to the values of the literature obtained for other properties such as the physical and mechanical properties of wood.
Tsuchiya, K.; Shioya, T.
2015-04-15
We have developed a practical method for determining an excellent initial arrangement of magnetic arrays for a pure-magnet Halbach-type undulator. In this method, the longitudinal magnetic field distribution of each magnet is measured using a moving Hall probe system along the beam axis with a high positional resolution. The initial arrangement of magnetic arrays is optimized and selected by analyzing the superposition of all distribution data in order to achieve adequate spectral quality for the undulator. We applied this method to two elliptically polarizing undulators (EPUs), called U#16-2 and U#02-2, at the Photon Factory storage ring (PF ring) in the High Energy Accelerator Research Organization (KEK). The measured field distribution of the undulator was demonstrated to be excellent for the initial arrangement of the magnet array, and this method saved a great deal of effort in adjusting the magnetic fields of EPUs.
Superposition of Cohesive Elements to Account for R-Curve Toughening in the Fracture of Composites
NASA Technical Reports Server (NTRS)
Davila, Carlos G.; Rose, Cheryl A.; Song, Kyongchan
2008-01-01
The relationships between a resistance curve (R-curve), the corresponding fracture process zone length, the shape of the traction/displacement softening law, and the propagation of fracture are examined in the context of the through-the-thickness fracture of composite laminates. A procedure that accounts for R-curve toughening mechanisms by superposing bilinear cohesive elements is proposed. Simple equations are developed for determining the separation of the critical energy release rates and the strengths that define the independent contributions of each bilinear softening law in the superposition. It is shown that the R-curve measured with a Compact Tension specimen test can be reproduced by superposing two bilinear softening laws. It is also shown that an accurate representation of the R-curve is essential for predicting the initiation and propagation of fracture in composite laminates.
Tsuchiya, K; Shioya, T
2015-04-01
We have developed a practical method for determining an excellent initial arrangement of magnetic arrays for a pure-magnet Halbach-type undulator. In this method, the longitudinal magnetic field distribution of each magnet is measured using a moving Hall probe system along the beam axis with a high positional resolution. The initial arrangement of magnetic arrays is optimized and selected by analyzing the superposition of all distribution data in order to achieve adequate spectral quality for the undulator. We applied this method to two elliptically polarizing undulators (EPUs), called U#16-2 and U#02-2, at the Photon Factory storage ring (PF ring) in the High Energy Accelerator Research Organization (KEK). The measured field distribution of the undulator was demonstrated to be excellent for the initial arrangement of the magnet array, and this method saved a great deal of effort in adjusting the magnetic fields of EPUs.
Precise position measurement of an atom using superposition of two standing wave fields
NASA Astrophysics Data System (ADS)
Idrees, M.; Bacha, B. A.; Javed, M.; Ullah, S. A.
2017-04-01
We present a scheme that provides a strong basis for precise localization of atoms, using superposition of two standing wave fields in a three level Λ -type gain assisted model. We show how atomic interference and diffraction occur at a particular node or antinode region of the standing wave fields. Two, three, four and even single localized peaks of atoms are observed in both full-wavelength and sub-half-wavelength domains, with 100 percent localization probability in a single peak. Dark lines appearing in the node region of the standing wave fields show strong evidence for atomic destructive interference. The proposed scheme allows for efficient localization of an atom to a particular point.
Murray, J.J.
1983-07-25
For the so-called superconducting FFS option with L* = 2.2 m, the MK2 solenoid does not overlap Q1, the FFS quad nearest the IP. For the permanent magnet option with L* = 0.75 m, the MK2 solenoid would overlap both Q1 and Q2. In either case an 8 m long solenoid, contemplated for the SLD detector, would overlap both Q1 and Q2. The solenoid field cannot be shielded so in an overlap region one will have a superposition of solenoid an quadrupole fields. Recently, the question was raised, What are the optical consequences when the solenoid and quad fields are superimposed. The question had not been considered before, but rough estimates suggested immediately that there might indeed be ugly consequences in terms of an enlargement of spot size at the IP. The purpose of this note is to answer the question quantitatively and to consider methods of correction of the ugly consequences.
Numerical model for macroscopic quantum superpositions based on phase-covariant quantum cloning
NASA Astrophysics Data System (ADS)
Buraczewski, A.; Stobińska, M.
2012-10-01
Macroscopically populated quantum superpositions pose a question to what extent the macroscopic world obeys quantum mechanical laws. Recently, such superpositions for light, generated by an optimal quantum cloner, have been demonstrated. They are of fundamental and technological interest. We present numerical methods useful for modeling of these states. Their properties are governed by a Gaussian hypergeometric function, which cannot be reduced to either elementary or easily tractable functions. We discuss the method of efficient computation of this function for half-integer parameters and a moderate value of its argument. We show how to dynamically estimate a cutoff for infinite sums involving this function performed over its parameters. Our algorithm exceeds double precision and is parallelizable. Depending on the experimental parameters it chooses one of the several ways of summation to achieve the best efficiency. The methods presented here can be adjusted for analysis of similar experimental schemes. Program summary Program title: MQSVIS Catalogue identifier: AEMR_ v1_ 0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1643 No. of bytes in distributed program, including test data, etc.: 13212 Distribution format: tar.gz Programming language: C with OpenMP extensions (main numerical program), Python (helper scripts). Computer: Modern PC (tested on AMD and Intel processors), HP BL2x220. Operating system: Unix/Linux. Has the code been vectorized or parallelized?: Yes (OpenMP). RAM: 200 MB for single run for 1000×1000 tile Classification: 4.15, 18. External routines: OpenMP Nature of problem: Recently, macroscopically populated quantum superpositions for light, generated by an optimal quantum cloner, have
Superposition and entanglement of mesoscopic squeezed vacuum states in cavity QED
Chen Changyong; Feng Mang; Gao Kelin
2006-03-15
We propose a scheme to generate superposition and entanglement between the mesoscopic squeezed vacuum states by considering the two-photon interaction of N two-level atoms in a cavity with high quality factor, assisted by a strong driving field. By virtue of specific choices of the cavity detuning, a number of multiparty entangled states can be prepared, including the entanglement between the atomic and the squeezed vacuum cavity states and between the squeezed vacuum states and the coherent states of the cavities. We also present how to prepare entangled states and 'Schroedinger cats' states regarding the squeezed vacuum states of the cavity modes. The possible extension and application of our scheme are discussed. Our scheme is close to the reach with current cavity QED techniques.
NASA Technical Reports Server (NTRS)
Mckay, J. M.; Kordes, E. E.; Wykes, J. H.
1973-01-01
The low frequency symmetric structural response and damping characteristics of the XB-70 airplane were measured at four flight conditions: heavyweight at a Mach number of 0.87 at an altitude of 7620 meters (25,000 feet); lightweight at a Mach number of 0.86 at an altitude of 7620 meters (25,000 feet); a Mach number of 1.59 at an altitude of 11,918 meters (39.100 feet); and a Mach number of 2.38 and an altitude of 18,898 meters (62,000 feet). The flight data are compared with the response calculated by using early XB-70 design data and with the response calculated with mass, structural, and aerodynamic data updated to reflect as closely as possible the airplane characteristics at three of the flight conditions actually flown.
NASA Astrophysics Data System (ADS)
Bendickson, Jon M.; Dowling, Jonathan P.; Scalora, Michael
1996-04-01
We derive an exact expression for the electromagnetic mode density, and hence the group velocity, for a finite, N-period, one-dimensional, photonic band-gap structure. We begin by deriving a general formula for the mode density in terms of the complex transmission coefficient of an arbitrary index profile. Then we develop a specific formula that gives the N-period mode density in terms of the complex transmission coefficient of the unit cell. The special cases of mode-density enhancement and suppression at the photonic band edge and also at midgap, respectively, are derived. The specific example of a quarter-wave stack is analyzed, and applications to three-dimensional structures, spontaneous emission control, delay lines, band-edge lasers, and superluminal tunneling times are discussed.
NASA Astrophysics Data System (ADS)
Heinen, Marco; Holmqvist, Peter; Banchio, Adolfo J.; Nägele, Gerhard
2011-01-01
We present a comprehensive study of the equilibrium pair structure in fluids of nonoverlapping spheres interacting by a repulsive Yukawa-like pair potential, with special focus on suspensions of charged colloidal particles. The accuracy of several integral equation schemes for the static structure factor, S(q), and radial distribution function, g(r), is investigated in comparison to computer simulation results and static light scattering data on charge-stabilized silica spheres. In particular, we show that an improved version of the so-called penetrating-background corrected rescaled mean spherical approximation (PB-RMSA) by Snook and Hayter [Langmuir 8, 2880 (1992)], referred to as the modified PB-RMSA (MPB-RMSA), gives pair structure functions which are in general in very good agreement with Monte Carlo simulations and results from the accurate but nonanalytical and therefore computationally more expensive Rogers-Young integral equation scheme. The MPB-RMSA preserves the analytic simplicity of the standard rescaled mean spherical (RMSA) solution. The combination of high accuracy and fast evaluation makes the MPB-RMSA ideally suited for extensive parameter scans and experimental data evaluation, and for providing the static input to dynamic theories. We discuss the results of extensive parameter scans probing the concentration scaling of the pair structure of strongly correlated Yukawa particles, and we determine the liquid-solid coexistence line using the Hansen-Verlet freezing rule.
Heinen, Marco; Holmqvist, Peter; Banchio, Adolfo J; Nägele, Gerhard
2011-01-28
We present a comprehensive study of the equilibrium pair structure in fluids of nonoverlapping spheres interacting by a repulsive Yukawa-like pair potential, with special focus on suspensions of charged colloidal particles. The accuracy of several integral equation schemes for the static structure factor, S(q), and radial distribution function, g(r), is investigated in comparison to computer simulation results and static light scattering data on charge-stabilized silica spheres. In particular, we show that an improved version of the so-called penetrating-background corrected rescaled mean spherical approximation (PB-RMSA) by Snook and Hayter [Langmuir 8, 2880 (1992)], referred to as the modified PB-RMSA (MPB-RMSA), gives pair structure functions which are in general in very good agreement with Monte Carlo simulations and results from the accurate but nonanalytical and therefore computationally more expensive Rogers-Young integral equation scheme. The MPB-RMSA preserves the analytic simplicity of the standard rescaled mean spherical (RMSA) solution. The combination of high accuracy and fast evaluation makes the MPB-RMSA ideally suited for extensive parameter scans and experimental data evaluation, and for providing the static input to dynamic theories. We discuss the results of extensive parameter scans probing the concentration scaling of the pair structure of strongly correlated Yukawa particles, and we determine the liquid-solid coexistence line using the Hansen-Verlet freezing rule.
An Improved Method of Heterogeneity Compensation for the Convolution / Superposition Algorithm
NASA Astrophysics Data System (ADS)
Jacques, Robert; McNutt, Todd
2014-03-01
Purpose: To improve the accuracy of convolution/superposition (C/S) in heterogeneous material by developing a new algorithm: heterogeneity compensated superposition (HCS). Methods: C/S has proven to be a good estimator of the dose deposited in a homogeneous volume. However, near heterogeneities electron disequilibrium occurs, leading to the faster fall-off and re-buildup of dose. We propose to filter the actual patient density in a position and direction sensitive manner, allowing the dose deposited near interfaces to be increased or decreased relative to C/S. We implemented the effective density function as a multivariate first-order recursive filter and incorporated it into GPU-accelerated, multi-energetic C/S implementation. We compared HCS against C/S using the ICCR 2000 Monte-Carlo accuracy benchmark, 23 similar accuracy benchmarks and 5 patient cases. Results: Multi-energetic HCS increased the dosimetric accuracy for the vast majority of voxels; in many cases near Monte-Carlo results were achieved. We defined the per-voxel error, %|mm, as the minimum of the distance to agreement in mm and the dosimetric percentage error relative to the maximum MC dose. HCS improved the average mean error by 0.79 %|mm for the patient volumes; reducing the average mean error from 1.93 %|mm to 1.14 %|mm. Very low densities (i.e. < 0.1 g / cm3) remained problematic, but may be solvable with a better filter function. Conclusions: HCS improved upon C/S's density scaled heterogeneity correction with a position and direction sensitive density filter. This method significantly improved the accuracy of the GPU based algorithm reaching the accuracy levels of Monte Carlo based methods with performance in a few tenths of seconds per beam. Acknowledgement: Funding for this research was provided by the NSF Cooperative Agreement EEC9731748, Elekta / IMPAC Medical Systems, Inc. and the Johns Hopkins University. James Satterthwaite provided the Monte Carlo benchmark simulations.
NASA Astrophysics Data System (ADS)
Jia, Dongming; Manz, Jörn; Paulus, Beate; Pohl, Vincent; Tremblay, Jean Christophe; Yang, Yonggang
2017-01-01
We design four linearly x- and y-polarized as well as circularly right (+) and left (-) polarized, resonant π / 2 -laser pulses that prepare the model benzene molecule in four different degenerate superposition states. These consist of equal (0.5) populations of the electronic ground state S0 (1A1g) plus one of four degenerate excited states, all of them accessible by dipole-allowed transitions. Specifically, for the molecule aligned in the xy-plane, these excited states include different complex-valued linear combinations of the 1E1u,x and 1E1u,y degenerate states. As a consequence, the laser pulses induce four different types of periodic adiabatic attosecond (as) charge migrations (AACM) in benzene, all with the same period, 504 as, but with four different types of angular fluxes. One of the characteristic differences of these fluxes are the two angles for zero fluxes, which appear as the instantaneous angular positions of the "source" and "sink" of two equivalent, or nearly equivalent branches of the fluxes which flow in pincer-type patterns from one molecular site (the "source") to the opposite one (the "sink"). These angles of zero fluxes are either fixed at the positions of two opposite carbon nuclei in the yz-symmetry plane, or at the centers of two opposite carbon-carbon bonds in the xz-symmetry plane, or the angles of zero fluxes rotate in angular forward (+) or backward (-) directions, respectively. As a resume, our quantum model simulations demonstrate quantum control of the electronic fluxes during AACM in degenerate superposition states, in the attosecond time domain, with the laser polarization as the key knob for control.
Afzal, Muhammad U. Esselle, Karu P.
2015-06-07
This paper presents a quasi-analytical technique to design a continuous, all-dielectric phase correcting structures (PCSs) for circularly polarized Fabry-Perot resonator antennas (FPRAs). The PCS has been realized by varying the thickness of a rotationally symmetric dielectric block placed above the antenna. A global analytical expression is derived for the PCS thickness profile, which is required to achieve nearly uniform phase distribution at the output of the PCS, despite the non-uniform phase distribution at its input. An alternative piecewise technique based on spline interpolation is also explored to design a PCS. It is shown from both far- and near-field results that a PCS tremendously improves the radiation performance of the FPRA. These improvements include an increase in peak directivity from 22 to 120 (from 13.4 dBic to 20.8 dBic) and a decrease of 3 dB beamwidth from 41.5° to 15°. The phase-corrected antenna also has a good directivity bandwidth of 1.3 GHz, which is 11% of the center frequency.
NASA Technical Reports Server (NTRS)
Blake, D. F.; Freund, Friedemann; Allard, L. F.; Echer, C. J.
1988-01-01
This paper describes the damage structure induced in natural CaF2 by the electron beam when using TEM. The observed 10-20 nm periodic features with coherent fringe patterns and the pronounced loss of fluorine found after the TEM exposure of 100-line-oriented and 111-oriented sections of CaF2 provides support for the mechanism of damage by decomposition of CaF2 into 2F and Ca, with the Ca precipitates maintaining a close topotaxial relationship with the parent CaF2.
NASA Astrophysics Data System (ADS)
Zamuraev, V. P.; Kalinina, A. P.
2015-01-01
The influence of a periodic supply of power pulses to the gas flow in a variable-section channel on the formation of shock structures in this flow was investigated. Parameters of the power supply providing different regimes of flow in the indicated channel and criteria of these regimes were determined on the basis of the solution of the problem of a powerful explosion with the use of the similarity theory and the homochronicity number. The results of the numerical simulation of the flow in the variable-section channel with power supply in the quasi-one-dimensional approximation and of the flows in cylindrical and plane channels were compared. The applicability of the analytical dependences obtained was substantiated by the results of the numerical solution of the quasi-one-dimensional and two-dimensional Euler equations for the flow of an ideal gas in the indicated channels.
Van Liew, Charles; Santoro, Maya S; Edwards, Larissa; Kang, Jeremy; Cronan, Terry A
2016-01-01
The Ways of Coping Questionnaire (WCQ) is a widely used measure of coping processes. Despite its use in a variety of populations, there has been concern about the stability and structure of the WCQ across different populations. This study examines the factor structure of the WCQ in a large sample of individuals diagnosed with fibromyalgia. The participants were 501 adults (478 women) who were part of a larger intervention study. Participants completed the WCQ at their 6-month assessment. Foundational factoring approaches were performed on the data (i.e., maximum likelihood factoring [MLF], iterative principal factoring [IPF], principal axis factoring (PAF), and principal components factoring [PCF]) with oblique oblimin rotation. Various criteria were evaluated to determine the number of factors to be extracted, including Kaiser's rule, Scree plot visual analysis, 5 and 10% unique variance explained, 70 and 80% communal variance explained, and Horn's parallel analysis (PA). It was concluded that the 4-factor PAF solution was the preferable solution, based on PA extraction and the fact that this solution minimizes nonvocality and multivocality. The present study highlights the need for more research focused on defining the limits of the WCQ and the degree to which population-specific and context-specific subscale adjustments are needed.
Frazier, Thomas W; Ratliff, Kristin R; Gruber, Chris; Zhang, Yi; Law, Paul A; Constantino, John N
2014-01-01
Understanding the factor structure of autistic symptomatology is critical to the discovery and interpretation of causal mechanisms in autism spectrum disorder. We applied confirmatory factor analysis and assessment of measurement invariance to a large (N = 9635) accumulated collection of reports on quantitative autistic traits using the Social Responsiveness Scale, representing a broad diversity of age, severity, and reporter type. A two-factor structure (corresponding to social communication impairment and restricted, repetitive behavior) as elaborated in the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) criteria for autism spectrum disorder exhibited acceptable model fit in confirmatory factor analysis. Measurement invariance was appreciable across age, sex, and reporter (self vs other), but somewhat less apparent between clinical and nonclinical populations in this sample comprised of both familial and sporadic autism spectrum disorders. The statistical power afforded by this large sample allowed relative differentiation of three factors among items encompassing social communication impairment (emotion recognition, social avoidance, and interpersonal relatedness) and two factors among items encompassing restricted, repetitive behavior (insistence on sameness and repetitive mannerisms). Cross-trait correlations remained extremely high, that is, on the order of 0.66-0.92. These data clarify domains of statistically significant factoral separation that may relate to partially-but not completely-overlapping biological mechanisms, contributing to variation in human social competency. Given such robust intercorrelations among symptom domains, understanding their co-emergence remains a high priority in conceptualizing common neural mechanisms underlying autistic syndromes.
Edwards, Larissa; Kang, Jeremy
2016-01-01
The Ways of Coping Questionnaire (WCQ) is a widely used measure of coping processes. Despite its use in a variety of populations, there has been concern about the stability and structure of the WCQ across different populations. This study examines the factor structure of the WCQ in a large sample of individuals diagnosed with fibromyalgia. The participants were 501 adults (478 women) who were part of a larger intervention study. Participants completed the WCQ at their 6-month assessment. Foundational factoring approaches were performed on the data (i.e., maximum likelihood factoring [MLF], iterative principal factoring [IPF], principal axis factoring (PAF), and principal components factoring [PCF]) with oblique oblimin rotation. Various criteria were evaluated to determine the number of factors to be extracted, including Kaiser's rule, Scree plot visual analysis, 5 and 10% unique variance explained, 70 and 80% communal variance explained, and Horn's parallel analysis (PA). It was concluded that the 4-factor PAF solution was the preferable solution, based on PA extraction and the fact that this solution minimizes nonvocality and multivocality. The present study highlights the need for more research focused on defining the limits of the WCQ and the degree to which population-specific and context-specific subscale adjustments are needed. PMID:28070160
NASA Astrophysics Data System (ADS)
Mangavel, C.; Sy, D.; Reynaud, J. A.
1999-05-01
A twenty amino acid residue long amphipathic peptide made of ten leucine and ten lysine residues and four derivatives, in which a tryptophan, as a fluorescent probe, is substituted for a leucine, are studied. The peptides in water are mainly in an unordered conformation (~90%), and undergo a two state reversible transition upon heating, leading to a partially helical conformation (cold denaturation). Time resolved fluorescence results show that fluorescence decay for the four Trp containing peptides is best described by triple fluorescence decay kinetics. In TFE/water mixture, peptides adopt a single α-helix conformation but the Leu-Trp9 substitution leads to an effective helix destabilizing effect. In salted media, the peptides are fully helical and present a great tendency to self associate by bringing the hydrophobic faces of helices into close contact. This proceeds in non-cooperative multisteps leading to the formation of α helix aggregates with various degrees of complexation. Using modelling, the relative hydrophobic surface areas accessible to water molecules in n-mer structures are calculated and discussed. Nous avons étudié un peptide amphipathique composé de dix lysine et dix leucine, ainsi que quatre dérivés comportant un résidu tryptophane pour les études par fluorescence. Dans l'eau, les peptides ne sont pas structurés (~90%), et se structurent partiellement en hélice α par chauffage (dénaturation froide). Les mesures de déclin de fluorescence font apparaître une cinétique à trois temps de vie. Dans un mélange eau/TFE, les peptides adoptent une conformation en hélice α, mais la substitution Leu-Trp9 possède un effet déstabilisant. En mileu salin, les peptides sont totalement hélicoïdaux et ont tendance à s'agréger de façon à regrouper leur face hydrophobe. Ce processus se fait en plusieurs étapes avec des agrégats de taille variable. L'existence de tels agrégats est discutée sur la base de la modélisation mol
Essau, Cecilia A; Olaya, Beatriz; Pasha, Gholamreza; O'Callaghan, Jean; Bray, Diane
2012-12-01
The present study examined the psychometric properties of the Iranian translation of the Spence Children's Anxiety Scale (SCAS) in a large community sample of adolescents (N = 1984), aged 12-17 years, in Ahvaz City, Iran. In addition to the SCAS, all participants completed the Strengths and Difficulties Questionnaire (SDQ), and the Centre for Epidemiological Studies Depression Scale for Children (CES-DC). The internal consistency (Cronbach Alpha = .92) and the validity of the Iranian translation of the SCAS was excellent. The SCAS total scores correlated significantly with the CES-DC, as well as with the emotional, conduct problems, hyperactivity-inattention, and peer problems subscales of the SDQ. However, Steiger's Z test demonstrated that correlations between the SCAS scores and the SDQ conduct problems or hyperactivity-inattention subscales were significantly lower than the correlations between the SCAS scores and the SDQ emotional symptoms subscale. Confirmatory factor analyses revealed the same 6-factor structure as the original SCAS. The SCAS proved to be a reliable and valid measure of anxiety symptoms among adolescents in Iran.
Tõnsuaadu, K; Gruselle, M; Villain, F; Thouvenot, R; Peld, M; Mikli, V; Traksmaa, R; Gredin, P; Carrier, X; Salles, L
2006-12-15
The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis. The amount of Ru in the modified apatite varies from 7.8 to 10.5 wt% and is not related to the initial composition or the specific surface area of the apatite. The different characterization techniques show that in the Ru-modified apatites Ru is surrounded by six oxygen atoms and do not contain any chlorine. For Ru-HAp and Ru-CO3HAp the new phase is amorphous whereas it is crystalline for FAp. The catalytic oxidation ability is higher for Ru-HAp and Ru-CO3HAp compared to Ru-FAp apatite in the oxidation of benzylic alcohol.
NASA Astrophysics Data System (ADS)
Wagner, Andrew James
As electronic and mechanical devices are scaled downward in size and upward in complexity, macroscopic principles no longer apply. Synthesis of three-dimensionally confined structures exhibit quantum confinement effects allowing, for example, silicon nanoparticles to luminesce. The reduction in size of classically brittle materials reveals a ductile-to-brittle transition. Such a transition, attributed to a reduction in defects, increases elasticity. In the case of silicon, elastic deformation can improve electronic carrier mobility by over 50%, a vital attribute of modern integrated circuits. The scalability of such principles and the changing atomistic processes which contribute to them presents a vitally important field of research. Beginning with the direct observation of dislocations and lattice planes in the 1950s, the transmission electron microscope has been a powerful tool in materials science. More recently, as nanoscale technologies have proliferated modern life, their unique ability to spatially resolve nano- and atomic-scale structures has become a critical component of materials research and characterization. Signals produced by an incident beam of high-energy electrons enables researchers to both image and chemically analyze materials at the atomic scale. Coherently and elastically-scattered electrons can be collected to produce atomic-scale images of a crystalline sample. New specimen stages have enabled routine investigation of samples heated up to 1000 °C and cooled to liquid nitrogen temperatures. MEMS-based transducers allow for sub-nm scale mechanical testing and ultrathin membranes allow study of liquids and gases. Investigation of a myriad of previously "unseeable" processes can now be observed within the TEM, and sometimes something new is found within the old. High-temperature annealing of pure a Si:H films leads to crystallization of the film. Such films provide higher carrier mobility compared to amorphous films, offering improved
Cooper, W Grant
2009-08-01
Evidence requiring transcriptase quantum processing is identified and elementary quantum methods are used to qualitatively describe origins and consequences of time-dependent coherent proton states populating informational DNA base pair sites in T4 phage, designated by G-C-->G'-C', G-C-->*G-*C and AT-->*A-*T. Coherent states at these 'point' DNA lesions are introduced as consequences of hydrogen bond arrangement, keto-amino-->enol-imine, where product protons are shared between two sets of indistinguishable electron lone-pairs, and thus, participate in coupled quantum oscillations at frequencies of approximately 10(13) s(-1). This quantum mixing of proton energy states introduces stability enhancements of approximately 0.25-7 kcal/mole. Transcriptase genetic specificity is determined by hydrogen bond components contributing to the formation of complementary interstrand hydrogen bonds which, in these cases, is variable due to coupled quantum oscillations of coherent enol-imine protons. The transcriptase deciphers and executes genetic specificity instructions by implementing measurements on superposition proton states at G'-C', *G-*C and *A-*T sites in an interval Deltat<10(-13) s. After initiation of transcriptase measurement, model calculations indicate proton decoherence time, tau(D), satisfies the relation Deltat
NASA Astrophysics Data System (ADS)
Lin, Erica; Li, Yaning; Ortiz, Christine; Boyce, Mary C.
2014-12-01
Geometrically structured interfaces in nature possess enhanced, and often surprising, mechanical properties, and provide inspiration for materials design. This paper investigates the mechanics of deformation and failure mechanisms of suture interface designs through analytical models and experiments on 3D printed polymer physical prototypes. Suture waveforms with generalized trapezoidal geometries (trapezoidal, rectangular, anti-trapezoidal, and triangular) are studied and characterized by several important geometric parameters: the presence or absence of a bonded tip region, the tip angle, and the geometry. It is shown that a wide range (in some cases as great as an order of magnitude) in stiffness, strength, and toughness is achievable dependent on tip bonding, tip angle, and geometry. Suture interfaces with a bonded tip region exhibit a higher initial stiffness due to the greater load bearing by the skeletal teeth, a double peak in the stress-strain curve corresponding to the failure of the bonded tip and the failure of the slanted interface region or tooth, respectively, and an additional failure and toughening mechanism due to the failure of the bonded tip. Anti-trapezoidal geometries promote the greatest amplification of properties for suture interfaces with a bonded tip due the large tip interface area. The tip angle and geometry govern the stress distributions in the teeth and the ratio of normal to shear stresses in the interfacial layers, which together determine the failure mechanism of the interface and/or the teeth. Rectangular suture interfaces fail by simple shearing of the interfaces. Trapezoidal and triangular suture interfaces fail by a combination of shear and tensile normal stresses in the interface, leading to plastic deformation, cavitation events, and subsequent stretching of interface ligaments with mostly elastic deformation in the teeth. Anti-trapezoidal suture interfaces with small tip angles have high stress concentrations in the teeth
NASA Astrophysics Data System (ADS)
Marsden, Catharine Chauvin
Modal testing is often employed in the determination of natural frequencies and damping levels in aircraft structures. In aircraft flutter testing, potentially dangerous flight regimes are avoided by obtaining modal frequency and damping values at airspeeds well below the flutter speed and extrapolating the data to estimate the airspeed at which the onset of flutter instabilities is expected to occur. In the modal analysis, the structure is typically assumed to be linear and the parameters to be time-invariant. Nonlinearities in aeroelastic systems can arise from both structural and aerodynamic sources and may initiate aeroelastic instabilities both above and below the flutter speed predicted by linear theory. Typical nonlinear responses include limit cycle oscillations and in some cases, chaotic response. For aeroelastic systems containing even small nonlinearities, the nonlinear frequency response curve may be distorted, and this distortion can contribute to errors in the values of frequency and damping obtained during modal testing. The current study includes an analytical and an experimental investigation into the modal testing of a nonlinear aeroelastic system. In the case of aeroelastic systems containing limited structural nonlinearities, the nonlinearity, although it changes the system frequency and damping values and distorts the transfer function, does not substantially affect the critical flutter speed. For this reason, the nonlinearity behaves a little like "noise" in that it prevents accurate values of frequency and damping from being obtained during the modal test. One solution to this problem is to separate the linear and nonlinear portions of the frequency response using spectral decomposition methods. In the analytical portion of this study, a specific spectral decomposition technique is tested on numerical data, and the results show that the technique may be used to separate the linear and nonlinear portions of the transfer function obtained from
NASA Technical Reports Server (NTRS)
Nikitin, S. P.; Masalov, A. V.
1992-01-01
The results of numerical simulations of quantum state evolution in the process of second harmonic generation (SHG) are discussed. It is shown that at a particular moment of time in the fundamental mode initially coherent state turns into a superposition of two macroscopically distinguished states. The question of whether this superposition exhibits quantum interference is analyzed.
Fodor, Kinga E; Pozen, Joanna; Ntaganira, Joseph; Sezibera, Vincent; Neugebauer, Richard
2015-05-01
The factor structure of posttraumatic stress disorder (PTSD) symptoms in Euro-American populations has been extensively studied, but confirmatory factor analytic studies from non-Western societies are lacking. Alternative models of DSM-IV symptoms were tested among Rwandan adults (N=465) who experienced trauma during the 1994 genocide. A cluster random survey was conducted with interviews held in Rwandan households. PTSD was assessed with the Posttraumatic Stress Disorder Checklist-Civilian version. Competing models were the DSM-IV, emotional numbing, dysphoria, aroused intrusion, and dysphoric arousal models. Results showed that the emotional numbing, dysphoria, and dysphoric arousal models had almost identical, good fit indices and fit the data significantly better than the other models. The emotional numbing and dysphoric arousal models also exhibited good construct validity. Results suggest that the latent structure of PTSD symptoms in Rwanda are comparable to that found in Euro-American samples, thereby lending further support to the cross-cultural validity of the construct.
Evaluation of axial and lateral modal superposition for general 3D drilling riser analysis
Burgdorf, O. Jr.
1996-12-31
A 3D partially non-linear transient fully-coupled riser analysis method is evaluated which uses modal superposition of independently extracted lateral and axial modes. Many lateral modes are combined with a lesser number axial modes to minimize adverse time step requirements typically induced by axial flexibility in direct time integration of beam-column elements. The reduced computer time option enables much faster parametric analysis of hang-off, as well as other connected drilling environments normally examined. Axial-lateral coupling is explicitly enforced and, resonance fidelity is preserved when excitation is near or coincident with axial natural periods. Reasonable correlation is shown with envelopes of test case dynamic responses published by API. Applicability of the method is limited by linearity assumptions indigenous to modal representation of dynamic deflections relative to a mean deflected shape. Sensitivities of incipient buckling during hang-off to axial damping and stiffness are described for an example 6,000 ft. deep composite drilling riser system.
NASA Astrophysics Data System (ADS)
Chen, Linfei; Gao, Xiong; Chen, Xudong; He, Bingyu; Liu, Jingyu; Li, Dan
2016-04-01
In this paper, a new optical image cryptosystem is proposed based on two-beam coherent superposition and unequal modulus decomposition. Different from the equal modulus decomposition or unit vector decomposition, the proposed method applies common vector decomposition to accomplish encryption process. In the proposed method, the original image is firstly Fourier transformed and the complex function in spectrum domain will be obtained. The complex distribution is decomposed into two vector components with unequal amplitude and phase by the common vector decomposition method. Subsequently, the two components are modulated by two random phases and transformed from spectrum domain to spatial domain, and amplitude parts are extracted as encryption results and phase parts are extracted as private keys. The advantages of the proposed cryptosystem are: four different phase and amplitude information created by the method of common vector decomposition strengthens the security of the cryptosystem, and it fully solves the silhouette problem. Simulation results are presented to show the feasibility and the security of the proposed cryptosystem.
Quantum superposition of a single microwave photon in two different 'colour' states
NASA Astrophysics Data System (ADS)
Zakka-Bajjani, Eva; Nguyen, François; Lee, Minhyea; Vale, Leila R.; Simmonds, Raymond W.; Aumentado, José
2011-08-01
Fully controlled coherent coupling of arbitrary harmonic oscillators is an important tool for processing quantum information. Coupling between quantum harmonic oscillators has previously been demonstrated in several physical systems using a two-level system as a mediating element. Direct interaction at the quantum level has only recently been realized by means of resonant coupling between trapped ions. Here we implement a tunable direct coupling between the microwave harmonics of a superconducting resonator by means of parametric frequency conversion. We accomplish this by coupling the mode currents of two harmonics through a superconducting quantum interference device (SQUID) and modulating its flux at the difference (~7GHz) of the harmonic frequencies. We deterministically prepare a single-photon Fock state and coherently manipulate it between multiple modes, effectively controlling it in a superposition of two different 'colours'. This parametric interaction can be described as a beamsplitter-like operation that couples different frequency modes. As such, it could be used to implement linear optical quantum computing protocols on-chip.
Large-field-of-view wide-spectrum artificial reflecting superposition compound eyes.
Huang, Chi-Chieh; Wu, Xiudong; Liu, Hewei; Aldalali, Bader; Rogers, John A; Jiang, Hongrui
2014-08-13
In nature, reflecting superposition compound eyes (RSCEs) found in shrimps, lobsters and some other decapods are extraordinary imaging systems with numerous optical features such as minimum chromatic aberration, wide-angle field of view (FOV), high sensitivity to light and superb acuity to motion. Here, we present life-sized, large-FOV, wide-spectrum artificial RSCEs as optical imaging devices inspired by the unique designs of their natural counterparts. Our devices can form real, clear images based on reflection rather than refraction, hence avoiding chromatic aberration due to dispersion by the optical materials. Compared to imaging at visible wavelengths using conventional refractive lenses of comparable size, our artificial RSCEs demonstrate minimum chromatic aberration, exceptional FOV up to 165° without distortion, modest aberrations and comparable imaging quality without any post-image processing. Together with an augmenting cruciform pattern surrounding each focused image, our large-FOV, wide-spectrum artificial RSCEs possess enhanced motion-tracking capability ideal for diverse applications in military, security, medical imaging and astronomy.
Stabilizing the phase of superpositions of cat states in a cavity using real-time feedback
NASA Astrophysics Data System (ADS)
Ofek, N.; Petrenko, A.; Heeres, R.; Reinhold, P.; Liu, Y.; Leghtas, Z.; Vlastakis, B.; Frunzio, L.; Jiang, Liang; Mirrahimi, M.; Devoret, M. H.; Schoelkopf, R. J.
In a superconducting cQED architecture, a hardware efficient quantum error correction (QEC) scheme exists, called the cat code, which maps a qubit onto superpositions of cat states in a superconducting resonator, by mapping the occurrence of errors, or single photon jumps, onto unitary rotations of the encoded state. By tracking the parity of the encoded state, we can count the number of photon jumps and are able to apply a correcting unitary transformation. However, the situation is complicated by the fact that photon jumps do not commute with the deterministic anharmonic time evolution of a resonator state, or Kerr, inherited by the resonator from its coupling to a Josephson junction. As predicted in, a field in the resonator will inherit an overall phase θ = KT in IQ space each time a photon jumps that is proportional to the Kerr K and the time T at which the jump occurs. Here I will present how we can track the errors in real time, take them into account together with the time they occur and make it possible to stabilize the qubit information. Please place my talk right after the talk of Andrei Petrenko.
Mochizuki, Koji; Takayama, Kozo
2014-01-01
This study reports the results of applying the time-temperature superposition principle (TTSP) to the prediction of color changes in liquid formulations. A sample solution consisting of L-tryptophan and glucose was used as the model liquid formulation for the Maillard reaction. After accelerated aging treatment at elevated temperatures, the Commission Internationale de l'Eclairage (CIE) LAB color parameters (a*, b*, L*, and E*ab) of the sample solution were measured using a spectrophotometer. The TTSP was then applied to a kinetic analysis of the color changes. The calculated values of the apparent activation energy of a*, b*, L*, and ΔE*ab were 105.2, 109.8, 91.6, and 103.7 kJ/mol, respectively. The predicted values of the color parameters at 40°C were calculated using Arrhenius plots for each of the color parameters. A comparison of the relationships between the experimental and predicted values of each color parameter revealed the coefficients of determination for a*, b*, L*, and ΔE*ab to be 0.961, 0.979, 0.960, and 0.979, respectively. All the R(2) values were sufficiently high, and these results suggested that the prediction was highly reliable. Kinetic analysis using the TTSP was successfully applied to calculating the apparent activation energy and to predicting the color changes at any temperature or duration.
Ultrafast convolution/superposition using tabulated and exponential kernels on GPU
Chen Quan; Chen Mingli; Lu Weiguo
2011-03-15
Purpose: Collapsed-cone convolution/superposition (CCCS) dose calculation is the workhorse for IMRT dose calculation. The authors present a novel algorithm for computing CCCS dose on the modern graphic processing unit (GPU). Methods: The GPU algorithm includes a novel TERMA calculation that has no write-conflicts and has linear computation complexity. The CCCS algorithm uses either tabulated or exponential cumulative-cumulative kernels (CCKs) as reported in literature. The authors have demonstrated that the use of exponential kernels can reduce the computation complexity by order of a dimension and achieve excellent accuracy. Special attentions are paid to the unique architecture of GPU, especially the memory accessing pattern, which increases performance by more than tenfold. Results: As a result, the tabulated kernel implementation in GPU is two to three times faster than other GPU implementations reported in literature. The implementation of CCCS showed significant speedup on GPU over single core CPU. On tabulated CCK, speedups as high as 70 are observed; on exponential CCK, speedups as high as 90 are observed. Conclusions: Overall, the GPU algorithm using exponential CCK is 1000-3000 times faster over a highly optimized single-threaded CPU implementation using tabulated CCK, while the dose differences are within 0.5% and 0.5 mm. This ultrafast CCCS algorithm will allow many time-sensitive applications to use accurate dose calculation.
Superposition of elliptic functions as solutions for a large number of nonlinear equations
NASA Astrophysics Data System (ADS)
Khare, Avinash; Saxena, Avadh
2014-03-01
For a large number of nonlinear equations, both discrete and continuum, we demonstrate a kind of linear superposition. We show that whenever a nonlinear equation admits solutions in terms of both Jacobi elliptic functions cn(x, m) and dn(x, m) with modulus m, then it also admits solutions in terms of their sum as well as difference. We have checked this in the case of several nonlinear equations such as the nonlinear Schrödinger equation, MKdV, a mixed KdV-MKdV system, a mixed quadratic-cubic nonlinear Schrödinger equation, the Ablowitz-Ladik equation, the saturable nonlinear Schrödinger equation, λϕ4, the discrete MKdV as well as for several coupled field equations. Further, for a large number of nonlinear equations, we show that whenever a nonlinear equation admits a periodic solution in terms of dn2(x, m), it also admits solutions in terms of dn^2(x,m) ± sqrt{m} cn(x,m) dn(x,m), even though cn(x, m)dn(x, m) is not a solution of these nonlinear equations. Finally, we also obtain superposed solutions of various forms for several coupled nonlinear equations.
NASA Astrophysics Data System (ADS)
Li, Hai-Sheng; Zhu, Qingxin; Zhou, Ri-Gui; Song, Lan; Yang, Xing-jiang
2014-04-01
Multi-dimensional color image processing has two difficulties: One is that a large number of bits are needed to store multi-dimensional color images, such as, a three-dimensional color image of needs bits. The other one is that the efficiency or accuracy of image segmentation is not high enough for some images to be used in content-based image search. In order to solve the above problems, this paper proposes a new representation for multi-dimensional color image, called a -qubit normal arbitrary quantum superposition state (NAQSS), where qubits represent colors and coordinates of pixels (e.g., represent a three-dimensional color image of only using 30 qubits), and the remaining 1 qubit represents an image segmentation information to improve the accuracy of image segmentation. And then we design a general quantum circuit to create the NAQSS state in order to store a multi-dimensional color image in a quantum system and propose a quantum circuit simplification algorithm to reduce the number of the quantum gates of the general quantum circuit. Finally, different strategies to retrieve a whole image or the target sub-image of an image from a quantum system are studied, including Monte Carlo sampling and improved Grover's algorithm which can search out a coordinate of a target sub-image only running in where and are the numbers of pixels of an image and a target sub-image, respectively.
NASA Technical Reports Server (NTRS)
Biezad, D. J.; Schmidt, D. K.; Leban, F.; Mashiko, S.
1986-01-01
Single-channel pilot manual control output in closed-tracking tasks is modeled in terms of linear discrete transfer functions which are parsimonious and guaranteed stable. The transfer functions are found by applying a modified super-position time series generation technique. A Levinson-Durbin algorithm is used to determine the filter which prewhitens the input and a projective (least squares) fit of pulse response estimates is used to guarantee identified model stability. Results from two case studies are compared to previous findings, where the source of data are relatively short data records, approximately 25 seconds long. Time delay effects and pilot seasonalities are discussed and analyzed. It is concluded that single-channel time series controller modeling is feasible on short records, and that it is important for the analyst to determine a criterion for best time domain fit which allows association of model parameter values, such as pure time delay, with actual physical and physiological constraints. The purpose of the modeling is thus paramount.
Securing multiple color information by optical coherent superposition based spiral phase encoding
NASA Astrophysics Data System (ADS)
Abuturab, Muhammad Rafiq
2014-05-01
A new optical multiple-color image cryptosystem using optical coherent superposition based spiral phase encoding is proposed, which can be applied to achieve a nonlinear multiple-image encryption of the same size. This multiplexed coding scheme is lensless, non time-consuming and decoding procedure is free from cross talk and noise effects in real time. In this contribution, a color image is decomposed into three independent channels, i.e., red, green and blue. Each channel is then divided into an arbitrarily selected spiral phase mask (SPM) and a spiral key mask (SKM). The selected SPM is introduced as an encrypted image for multiple color images. The SKMs are employed as different decryption keys for different images. That means, only need is to send the construction parameters (as the order, the wavelength, the focal length, and the radius) of the SPM independently to multiple-user, but not the key itself, so it enhances robustness against existing attacks than double random phase encoding techniques. Moreover, the maximum data can be securely handled with a single parameter variation. The encryption process can be performed digitally while the decryption process is very simple and can be implemented using optoelectronic architecture. A set of numerical simulation results confirm the feasibility and effectiveness of the proposed cryptosystem for multiple-color image encryption.
Quantum Delayed-Choice Experiment with a Beam Splitter in a Quantum Superposition
NASA Astrophysics Data System (ADS)
Zheng, Shi-Biao; Zhong, You-Peng; Xu, Kai; Wang, Qi-Jue; Wang, H.; Shen, Li-Tuo; Yang, Chui-Ping; Martinis, John M.; Cleland, A. N.; Han, Si-Yuan
2015-12-01
A quantum system can behave as a wave or as a particle, depending on the experimental arrangement. When, for example, measuring a photon using a Mach-Zehnder interferometer, the photon acts as a wave if the second beam splitter is inserted, but as a particle if this beam splitter is omitted. The decision of whether or not to insert this beam splitter can be made after the photon has entered the interferometer, as in Wheeler's famous delayed-choice thought experiment. In recent quantum versions of this experiment, this decision is controlled by a quantum ancilla, while the beam splitter is itself still a classical object. Here, we propose and realize a variant of the quantum delayed-choice experiment. We configure a superconducting quantum circuit as a Ramsey interferometer, where the element that acts as the first beam splitter can be put in a quantum superposition of its active and inactive states, as verified by the negative values of its Wigner function. We show that this enables the wave and particle aspects of the system to be observed with a single setup, without involving an ancilla that is not itself a part of the interferometer. We also study the transition of this quantum beam splitter from a quantum to a classical object due to decoherence, as observed by monitoring the interferometer output.
Probing the conductance superposition law in single-molecule circuits with parallel paths.
Vazquez, H; Skouta, R; Schneebeli, S; Kamenetska, M; Breslow, R; Venkataraman, L; Hybertsen, M S
2012-10-01
According to Kirchhoff's circuit laws, the net conductance of two parallel components in an electronic circuit is the sum of the individual conductances. However, when the circuit dimensions are comparable to the electronic phase coherence length, quantum interference effects play a critical role, as exemplified by the Aharonov-Bohm effect in metal rings. At the molecular scale, interference effects dramatically reduce the electron transfer rate through a meta-connected benzene ring when compared with a para-connected benzene ring. For longer conjugated and cross-conjugated molecules, destructive interference effects have been observed in the tunnelling conductance through molecular junctions. Here, we investigate the conductance superposition law for parallel components in single-molecule circuits, particularly the role of interference. We synthesize a series of molecular systems that contain either one backbone or two backbones in parallel, bonded together cofacially by a common linker on each end. Single-molecule conductance measurements and transport calculations based on density functional theory show that the conductance of a double-backbone molecular junction can be more than twice that of a single-backbone junction, providing clear evidence for constructive interference.
Fast 3D molecular superposition and similarity search in databases of flexible molecules
NASA Astrophysics Data System (ADS)
Krämer, Andreas; Horn, Hans W.; Rice, Julia E.
2003-01-01
We present a new method (fFLASH) for the virtual screening of compound databases that is based on explicit three-dimensional molecular superpositions. fFLASH takes the torsional flexibility of the database molecules fully into account, and can deal with an arbitrary number of conformation-dependent molecular features. The method utilizes a fragmentation-reassembly approach which allows for an efficient sampling of the conformational space. A fast clique-based pattern matching algorithm generates alignments of pairs of adjacent molecular fragments on the rigid query molecule that are subsequently reassembled to complete database molecules. Using conventional molecular features (hydrogen bond donors and acceptors, charges, and hydrophobic groups) we show that fFLASH is able to rapidly produce accurate alignments of medium-sized drug-like molecules. Experiments with a test database containing a diverse set of 1780 drug-like molecules (including all conformers) have shown that average query processing times of the order of 0.1 seconds per molecule can be achieved on a PC.
Cevidanes, Lucia H.S.; Styner, Martin; Proffit, William R.; Ngom, Traduit par Papa Ibrahima
2010-01-01
RÉSUMÉ – Pour évaluer les modifications liées à la croissance ou au traitement, il est nécessaire de superposer les céphalogrammes successifs sur une structure stable. En céphalométrie bidimensionnelle (2-D), la base du crâne est souvent utilisée pour les superpositions parce que les changements qu’elle subit après le développement cérébral sont mineurs. Toutefois, sur les céphalogrammes de profil et de face, les points de repère basicraniens sont peu fiables. Dans cet article, nous présentons une nouvelle méthode de superposition tridimensionnelle (3-D) basée sur un enregistrement entièrement automatisé des intensités de voxels, au niveau de la surface de la base du crâne. Le progiciel utilisé permet l’évaluation quantitative des modifications qui apparaissent dans le temps, grâce au calcul de la distance euclidienne entre les surfaces du modèle tridimensionnel. Il permet également l’appréciation visuelle de l’emplacement et de l’importance des modifications au niveau des maxillaires, grâce à une surimpression graphique. Les modifications sont visualisées par comparaison à des tables de correspondance de couleur. On peut ainsi réaliser une étude détaillée des modes d’adaptation chez les patients dont la croissance et/ou le traitement ont provoqué des modifications squelettiques cliniquement significatives. PMID:19954732
Analytical method for thermal stress analysis of plasma facing materials
NASA Astrophysics Data System (ADS)
You, J. H.; Bolt, H.
2001-10-01
The thermo-mechanical response of plasma facing materials (PFMs) to heat loads from the fusion plasma is one of the crucial issues in fusion technology. In this work, a fully analytical description of the thermal stress distribution in armour tiles of plasma facing components is presented which is expected to occur under typical high heat flux (HHF) loads. The method of stress superposition is applied considering the temperature gradient and thermal expansion mismatch. Several combinations of PFMs and heat sink metals are analysed and compared. In the framework of the present theoretical model, plastic flow and the effect of residual stress can be quantitatively assessed. Possible failure features are discussed.
NASA Technical Reports Server (NTRS)
Blichfeldt, B.; Mccarty, J. E.
1972-01-01
Specimens representative of metal aircraft structural components reinforced with boron filamentary composites were manufactured and tested under cyclic loading, cyclic temperature, or continuously applied loading to evaluate some of the factors that affect structural integrity under cyclic conditions. Bonded, stepped joints were used throughout to provide composite-to-metal transition regions at load introduction points. Honeycomb panels with titanium or aluminum faces reinforced with unidirectional boron composite were fatigue tested at constant amplitude under completely reversed loading. Results indicated that the matrix material was the most fatigue-sensitive part of the design, with debonding initiating in the stepped joints. However, comparisons with equal weight all-metal specimens show a 10 to 50 times improved fatigue life. Fatigue crack propagation and residual strength were studied for several different stiffened panel concepts, and were found to vary considerably depending on the configuration. Composite-reinforced metal specimens were also subjected to creep and thermal cycling tests. Thermal cycling of stepped joint tensile specimens resulted in a ten percent decrease in residual strength after 4000 cycles.
Zhang, Cheng; Ingram, Isaiah C; Hantao, Leandro W; Anderson, Jared L
2015-03-20
A series of dicationic ionic liquid (IL)-based stationary phases were evaluated as secondary columns in comprehensive two-dimensional gas chromatography (GC×GC) for the separation of aliphatic hydrocarbons from kerosene. In order to understand the role that structural features of ILs play on the selectivity of nonpolar analytes, the solvation parameter model was used to probe the solvation properties of the IL-based stationary phases. It was observed that room temperature ILs containing long free alkyl side chain substituents and long linker chains between the two cations possess less cohesive forces and exhibited the highest resolution of aliphatic hydrocarbons. The anion component of the IL did not contribute significantly to the overall separation, as similar selectivities toward aliphatic hydrocarbons were observed when examining ILs with identical cations and different anions. In an attempt to further examine the separation capabilities of the IL-based GC stationary phases, columns of the best performing stationary phases were prepared with higher film thickness and resulted in enhanced selectivity of aliphatic hydrocarbons.
Understanding Business Analytics
2015-01-05
Business Analytics, Decision Analytics, Business Intelligence, Advanced Analytics, Data Science. . . to a certain degree, to label is to limit - if only... Business Analytics. 2004 2006 2008 2010 2012 2014 Figure 1: Google trending of daily searches for various analytic disciplines “The limits of my
Analytical Investigation of the Caudrey-Dodd Equation Using Symbolic Computation
NASA Astrophysics Data System (ADS)
Xu, Xiao-Ge; Meng, Xiang-Hua; Zhang, Chun-Yi; Gao, Yi-Tian
2013-03-01
In this paper, the Caudrey-Dodd-Gibbon-Kotera-Sawada (CDGKS) equation is analytically investigated using the Hirota bilinear method. Based on the bilinear form of the CDGKS equation, its N-soliton solution in explicit form is derived with the aid of symbolic computation. Besides the soliton solutions, several integrable properties such as the Bäcklund transformation, the Lax pair and the nonlinear superposition formula are also derived for the CDGKS equation.
Fast Electron Correlation Methods for Molecular Clusters without Basis Set Superposition Errors
Kamiya, Muneaki; Hirata, So; Valiev, Marat
2008-02-19
Two critical extensions to our fast, accurate, and easy-to-implement binary or ternary interaction method for weakly-interacting molecular clusters [Hirata et al. Mol. Phys. 103, 2255 (2005)] have been proposed, implemented, and applied to water hexamers, hydrogen fluoride chains and rings, and neutral and zwitterionic glycine–water clusters with an excellent result for an initial performance assessment. Our original method included up to two- or three-body Coulomb, exchange, and correlation energies exactly and higher-order Coulomb energies in the dipole–dipole approximation. In this work, the dipole moments are replaced by atom-centered point charges determined so that they reproduce the electrostatic potentials of the cluster subunits as closely as possible and also self-consistently with one another in the cluster environment. They have been shown to lead to dramatic improvement in the description of short-range electrostatic potentials not only of large, charge-separated subunits like zwitterionic glycine but also of small subunits. Furthermore, basis set superposition errors (BSSE) known to plague direct evaluation of weak interactions have been eliminated by com-bining the Valiron–Mayer function counterpoise (VMFC) correction with our binary or ternary interaction method in an economical fashion (quadratic scaling n2 with respect to the number of subunits n when n is small and linear scaling when n is large). A new variant of VMFC has also been proposed in which three-body and all higher-order Coulomb effects on BSSE are estimated approximately. The BSSE-corrected ternary interaction method with atom-centered point charges reproduces the VMFC-corrected results of conventional electron correlation calculations within 0.1 kcal/mol. The proposed method is significantly more accurate and also efficient than conventional correlation methods uncorrected of BSSE.
NASA Astrophysics Data System (ADS)
White, J. A.
2014-12-01
As a significant fraction of a carbon storage project's budget is devoted to site characterization and monitoring, there has been an intense drive in recent years to both lower cost and improve the quality of data obtained. Two data streams that are cheap and always available are pressure and flow rate measurements from the injection well. Falloff testing, in which the well is shut-in for some period of time and the pressure decline curve measured, is often used to probe the storage zone and look for indications of hydraulic barriers, fracture-dominated flow, and other reservoir characteristics. These tests can be used to monitor many hydromechanical processes of interest, including hydraulic fracturing and fault reactivation. Unfortunately, the length of the shut-in period controls how far away from the injector information may be obtained. For operational reasons these tests are typically kept short and infrequent, limiting their usefulness. In this work, we present a new analysis method in which ongoing injection data is used to reconstruct an equivalent falloff test, without shutting in the well. The entire history of injection may therefore be used as a stand in for a very long test. The method relies upon a simple superposition principle to transform a multi-rate injection sequence into an equivalent single-rate process. We demonstrate the effectiveness of the method using injection data from the Snøhvit storage project. We also explore its utility in an active pressure management scenario. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Bioeffects induced by exposure to microwaves are mitigated by superposition of ELF noise.
Litovitz, T A; Penafiel, L M; Farrel, J M; Krause, D; Meister, R; Mullins, J M
1997-01-01
We have previously demonstrated that microwave fields, amplitude modulated (AM) by an extremely low-frequency (ELF) sine wave, can induce a nearly twofold enhancement in the activity of ornithine decarboxylase (ODC) in L929 cells at SAR levels of the order of 2.5 W/kg. Similar, although less pronounced, effects were also observed from exposure to a typical digital cellular phone test signal of the same power level, burst modulated at 50 Hz. We have also shown that ODC enhancement in L929 cells produced by exposure to ELF fields can be inhibited by superposition of ELF noise. In the present study, we explore the possibility that similar inhibition techniques can be used to suppress the microwave response. We concurrently exposed L929 cells to 60 Hz AM microwave fields or a 50 Hz burst-modulated DAMPS (Digital Advanced Mobile Phone System) digital cellular phone field at levels known to produce ODC enhancement, together with band-limited 30-100 Hz ELF noise with root mean square amplitude of up to 10 microT. All exposures were carried out for 8 h, which was previously found to yield the peak microwave response. In both cases, the ODC enhancement was found to decrease exponentially as a function of the noise root mean square amplitude. With 60 Hz AM microwaves, complete inhibition was obtained with noise levels at or above 2 microT. With the DAMPS digital cellular phone signal, complete inhibition occurred with noise levels at or above 5 microT. These results suggest a possible practical means to inhibit biological effects from exposure to both ELF and microwave fields.
Mochizuki, Koji; Takayama, Kozo
2016-01-01
A prediction method for color changes based on the time-temperature superposition principle (TTSP) was developed for acetaminophen solution. Color changes of acetaminophen solution are caused by the degradation of acetaminophen, such as hydrolysis and oxidation. In principle, the TTSP can be applied to only thermal aging. Therefore, the impact of oxidation on the color changes of acetaminophen solution was verified. The results of our experiment suggested that the oxidation products enhanced the color changes in acetaminophen solution. Next, the color changes of acetaminophen solution samples of the same head space volume after accelerated aging at various temperatures were investigated using the Commission Internationale de l'Eclairage (CIE) LAB color space (a*, b*, L* and ΔE*ab), following which the TTSP was adopted to kinetic analysis of the color changes. The apparent activation energies using the time-temperature shift factor of a*, b*, L* and ΔE*ab were calculated as 72.4, 69.2, 72.3 and 70.9 (kJ/mol), respectively, which are similar to the values for acetaminophen hydrolysis reported in the literature. The predicted values of a*, b*, L* and ΔE*ab at 40 °C were obtained by calculation using Arrhenius plots. A comparison between the experimental and predicted values for each color parameter revealed sufficiently high R(2) values (>0.98), suggesting the high reliability of the prediction. The kinetic analysis using TTSP was successfully applied to predicting the color changes under the controlled oxygen amount at any temperature and for any length of time.
NASA Astrophysics Data System (ADS)
Copeland, Kyle
2015-07-01
The superposition approximation was commonly employed in atmospheric nuclear transport modeling until recent years and is incorporated into flight dose calculation codes such as CARI-6 and EPCARD. The useful altitude range for this approximation is investigated using Monte Carlo transport techniques. CARI-7A simulates atmospheric radiation transport of elements H-Fe using a database of precalculated galactic cosmic radiation showers calculated with MCNPX 2.7.0 and is employed here to investigate the influence of the superposition approximation on effective dose rates, relative to full nuclear transport of galactic cosmic ray primary ions. Superposition is found to produce results less than 10% different from nuclear transport at current commercial and business aviation altitudes while underestimating dose rates at higher altitudes. The underestimate sometimes exceeds 20% at approximately 23 km and exceeds 40% at 50 km. Thus, programs employing this approximation should not be used to estimate doses or dose rates for high-altitude portions of the commercial space and near-space manned flights that are expected to begin soon.
NASA Astrophysics Data System (ADS)
Balabin, Roman M.
2011-03-01
The quantum chemistry of conformation equilibrium is a field where great accuracy (better than 100 cal mol-1) is needed because the energy difference between molecular conformers rarely exceeds 1000-3000 cal mol-1. The conformation equilibrium of straight-chain (normal) alkanes is of particular interest and importance for modern chemistry. In this paper, an extra error source for high-quality ab initio (first principles) and DFT calculations of the conformation equilibrium of normal alkanes, namely the intramolecular basis set superposition error (BSSE), is discussed. In contrast to out-of-plane vibrations in benzene molecules, diffuse functions on carbon and hydrogen atoms were found to greatly reduce the relative BSSE of n-alkanes. The corrections due to the intramolecular BSSE were found to be almost identical for the MP2, MP4, and CCSD(T) levels of theory. Their cancelation is expected when CCSD(T)/CBS (CBS, complete basis set) energies are evaluated by addition schemes. For larger normal alkanes (N > 12), the magnitude of the BSSE correction was found to be up to three times larger than the relative stability of the conformer; in this case, the basis set superposition error led to a two orders of magnitude difference in conformer abundance. No error cancelation due to the basis set superposition was found. A comparison with amino acid, peptide, and protein data was provided.
Fabricating Cotton Analytical Devices.
Lin, Shang-Chi; Hsu, Min-Yen; Kuan, Chen-Meng; Tseng, Fan-Gang; Cheng, Chao-Min
2016-08-30
A robust, low-cost analytical device should be user-friendly, rapid, and affordable. Such devices should also be able to operate with scarce samples and provide information for follow-up treatment. Here, we demonstrate the development of a cotton-based urinalysis (i.e., nitrite, total protein, and urobilinogen assays) analytical device that employs a lateral flow-based format, and is inexpensive, easily fabricated, rapid, and can be used to conduct multiple tests without cross-contamination worries. Cotton is composed of cellulose fibers with natural absorptive properties that can be leveraged for flow-based analysis. The simple but elegant fabrication process of our cotton-based analytical device is described in this study. The arrangement of the cotton structure and test pad takes advantage of the hydrophobicity and absorptive strength of each material. Because of these physical characteristics, colorimetric results can persistently adhere to the test pad. This device enables physicians to receive clinical information in a timely manner and shows great potential as a tool for early intervention.
NASA Astrophysics Data System (ADS)
Chen, Hai-Long; Jin, Feng-Nian; Fan, Hua-Lin
2013-02-01
Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equation of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal superposition. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.
NASA Astrophysics Data System (ADS)
Lee, Yueh-Ning; Hennebelle, Patrick
2016-06-01
Context. Most stars are born in the gaseous protocluster environment where the gas is reprocessed after the global collapse from the diffuse molecular cloud. The knowledge of this intermediate step gives more accurate constraints on star formation characteristics. Aims: We demonstrate that a virialized globally supported structure, in which star formation happens, is formed out of a collapsing molecular cloud, and we derive a mapping from the parent cloud parameters to the protocluster to predict its properties with a view to confront analytical calculations with observations and simulations. Methods: We decomposed the virial theorem into two dimensions to account for the rotation and the flattened geometry. Equilibrium was found by balancing rotation, turbulence, and self-gravity, while turbulence was maintained through accretion driving and it dissipates in one crossing time. We estimated the angular momentum and the accretion rate of the protocluster from the parent cloud properties. Results: The two-dimensional virial model predicts the size and velocity dispersion given the mass of the protocluster and that of the parent cloud. The gaseous protoclusters lie on a sequence of equilibrium with the trend R ~ M0.5 with limited variations, depending on the evolutionary stage, parent cloud, and parameters that are not well known, such as turbulence driving efficiency by accretion and turbulence anisotropy. The model reproduces observations and simulation results successfully. Conclusions: The properties of protoclusters follow universal relations and they can be derived from that of the parent cloud. The gaseous protocluster is an important primary stage of stellar cluster formation, and should be taken into account when studying star formation. Using simple estimates to infer the peak position of the core mass function (CMF) we find a weak dependence on the cluster mass, suggesting that the physical conditions inside protoclusters may contribute to set a CMF, and by
Large-field-of-view wide-spectrum artificial reflecting superposition compound eyes
NASA Astrophysics Data System (ADS)
Huang, Chi-Chieh
The study of the imaging principles of natural compound eyes has become an active area of research and has fueled the advancement of modern optics with many attractive design features beyond those available with conventional technologies. Most prominent among all compound eyes is the reflecting superposition compound eyes (RSCEs) found in some decapods. They are extraordinary imaging systems with numerous optical features such as minimum chromatic aberration, wide-angle field of view (FOV), high sensitivity to light and superb acuity to motion. Inspired by their remarkable visual system, we were able to implement the unique lens-free, reflection-based imaging mechanisms into a miniaturized, large-FOV optical imaging device operating at the wide visible spectrum to minimize chromatic aberration without any additional post-image processing. First, two micro-transfer printing methods, a multiple and a shear-assisted transfer printing technique, were studied and discussed to realize life-sized artificial RSCEs. The processes exploited the differential adhesive tendencies of the microstructures formed between a donor and a transfer substrate to accomplish an efficient release and transfer process. These techniques enabled conformal wrapping of three-dimensional (3-D) microstructures, initially fabricated in two-dimensional (2-D) layouts with standard fabrication technology onto a wide range of surfaces with complex and curvilinear shapes. Final part of this dissertation was focused on implementing the key operational features of the natural RSCEs into large-FOV, wide-spectrum artificial RSCEs as an optical imaging device suitable for the wide visible spectrum. Our devices can form real, clear images based on reflection rather than refraction, hence avoiding chromatic aberration due to dispersion by the optical materials. Compared to the performance of conventional refractive lenses of comparable size, our devices demonstrated minimum chromatic aberration, exceptional
Liposomes: Technologies and Analytical Applications
NASA Astrophysics Data System (ADS)
Jesorka, Aldo; Orwar, Owe
2008-07-01
Liposomes are structurally and functionally some of the most versatile supramolecular assemblies in existence. Since the beginning of active research on lipid vesicles in 1965, the field has progressed enormously and applications are well established in several areas, such as drug and gene delivery. In the analytical sciences, liposomes serve a dual purpose: Either they are analytes, typically in quality-assessment procedures of liposome preparations, or they are functional components in a variety of new analytical systems. Liposome immunoassays, for example, benefit greatly from the amplification provided by encapsulated markers, and nanotube-interconnected liposome networks have emerged as ultrasmall-scale analytical devices. This review provides information about new developments in some of the most actively researched liposome-related topics.
Semi-analytical computation of displacement in linear viscoelastic materials
NASA Astrophysics Data System (ADS)
Spinu, S.; Gradinaru, D.
2015-11-01
Prediction of mechanical contact performance based on elastic models is not accurate in case of viscoelastic materials; however, a closed-form description of the viscoelastic contact has yet to be found. This paper aims to advance a semi-analytical method for computation of displacement induced in viscoelastic materials by arbitrary surface tractions, as a prerequisite to a semi-analytical solution for the viscoelastic contact problem. The newly advanced model is expected to provide greater generality, allowing for arbitrary contact geometry and / or arbitrary loading history. While time-independent equations in the purely elastic model can be treated numerically by imposing a spatial discretization only, a viscoelastic constitutive law requires supplementary temporal discretization capable of simulating the memory effect specific to viscoelastic materials. By deriving new influence coefficients, computation of displacement induced in a viscoelastic material by a known but otherwise arbitrary history of surface tractions can be achieved via superposition authorized by the Boltzmann superposition theory applicable in the frame of linear viscoelasticity.
NASA Astrophysics Data System (ADS)
Kypraios, Ioannis; Young, Rupert C. D.; Birch, Philip M.; Chatwin, Christopher R.
2003-08-01
The various types of synthetic discriminant function (sdf) filter result in a weighted linear superposition of the training set images. Neural network training procedures result in a non-linear superposition of the training set images or, effectively, a feature extraction process, which leads to better interpolation properties than achievable with the sdf filter. However, generally, shift invariance is lost since a data dependant non-linear weighting function is incorporated in the input data window. As a compromise, we train a non-linear superposition filter via neural network methods with the constraint of a linear input to allow for shift invariance. The filter can then be used in a frequency domain based optical correlator. Simulation results are presented that demonstrate the improved training set interpolation achieved by the non-linear filter as compared to a linear superposition filter.
ERIC Educational Resources Information Center
MacNeill, Sheila; Campbell, Lorna M.; Hawksey, Martin
2014-01-01
This article presents an overview of the development and use of analytics in the context of education. Using Buckingham Shum's three levels of analytics, the authors present a critical analysis of current developments in the domain of learning analytics, and contrast the potential value of analytics research and development with real world…
ERIC Educational Resources Information Center
Oblinger, Diana G.
2012-01-01
Talk about analytics seems to be everywhere. Everyone is talking about analytics. Yet even with all the talk, many in higher education have questions about--and objections to--using analytics in colleges and universities. In this article, the author explores the use of analytics in, and all around, higher education. (Contains 1 note.)
NASA Astrophysics Data System (ADS)
Famulari, Antonino; Specchio, Roberto; Sironi, Maurizio; Raimondi, Mario
1998-02-01
Recently, a controversy has come to light in literature regarding the structure of water in nonambient conditions. Disagreement is evident between the site-site pair correlation functions of water derived from neutron diffraction and those obtained by computer simulations which employ effective pairwise potentials to express the intermolecular interactions. In this paper the SCFMI method (self-consistent field for molecular interaction) followed by nonorthogonal CI (configuration interaction) calculations was used to determine a new water-water interaction potential, which is BSSE (basis set superposition error) free in an a priori fashion. Extensive calculations were performed on water dimer and trimer and a new parametrization of a NCC-like (Niesar-Corongiu-Clementi) potential was accomplished. This was employed in the molecular-dynamics simulation of water. The effect of temperature and density variations was examined. Acceptable agreement between site-site correlation functions derived from neutron diffraction data and from computer simulation was reached. In particular, a weakening of the hydrogen bonded structure was observed on approaching the critical point, which reproduces the experimental behavior. The simulations were performed using the MOTECC (modern techniques in computational chemistry) suite of programs. The present results show the importance of BSSE-free nonorthogonal orbitals in an accurate description of the intermolecular potential of water.
A SEMI-ANALYTICAL LINE TRANSFER MODEL TO INTERPRET THE SPECTRA OF GALAXY OUTFLOWS
Scarlata, C.; Panagia, N.
2015-03-01
We present a semi-analytical line transfer model, (SALT), to study the absorption and re-emission line profiles from expanding galactic envelopes. The envelopes are described as a superposition of shells with density and velocity varying with the distance from the center. We adopt the Sobolev approximation to describe the interaction between the photons escaping from each shell and the remainder of the envelope. We include the effect of multiple scatterings within each shell, properly accounting for the atomic structure of the scattering ions. We also account for the effect of a finite circular aperture on actual observations. For equal geometries and density distributions, our models reproduce the main features of the profiles generated with more complicated transfer codes. Also, our SALT line profiles nicely reproduce the typical asymmetric resonant absorption line profiles observed in starforming/starburst galaxies whereas these absorption profiles cannot be reproduced with thin shells moving at a fixed outflow velocity. We show that scattered resonant emission fills in the resonant absorption profiles, with a strength that is different for each transition. Observationally, the effect of resonant filling depends on both the outflow geometry and the size of the outflow relative to the spectroscopic aperture. Neglecting these effects will lead to incorrect values of gas covering fraction and column density. When a fluorescent channel is available, the resonant profiles alone cannot be used to infer the presence of scattered re-emission. Conversely, the presence of emission lines of fluorescent transitions reveals that emission filling cannot be neglected.
Di Rienzo, Lorenzo; Milanetti, Edoardo; Lepore, Rosalba; Olimpieri, Pier Paolo; Tramontano, Anna
2017-01-01
We describe here a superposition free method for comparing the surfaces of antibody binding sites based on the Zernike moments and show that they can be used to quickly compare and cluster sets of antibodies. The clusters provide information about the nature of the bound antigen that, when combined with a method for predicting the number of direct antibody antigen contacts, allows the discrimination between protein and non-protein binding antibodies with an accuracy of 76%. This is of relevance in several aspects of antibody science, for example to select the framework to be used for a combinatorial antibody library. PMID:28338016
NASA Technical Reports Server (NTRS)
Bringemeier, D.
1992-01-01
Research undertaken in the last decades in Noerdlinger Ries, Germany, has repeatedly emphasized the sharp contact between Bunte breccia and suevite. However, extensive investigations into this layer boundary have not yet been possible due to insufficient outcrop ratios. New outcrops enabled an in-depth investigation into the superposition of suevite on the Bunte breccia, which is assigned a key role in interpreting the transport mechanisms of ejecta of large impact. In two quarries lying several kilometers east and south-southwest of the crater, the contact between the suevite and Bunte breccia was recorded in detailed sections on outcrops of over 50 m in length.
Di Rienzo, Lorenzo; Milanetti, Edoardo; Lepore, Rosalba; Olimpieri, Pier Paolo; Tramontano, Anna
2017-03-24
We describe here a superposition free method for comparing the surfaces of antibody binding sites based on the Zernike moments and show that they can be used to quickly compare and cluster sets of antibodies. The clusters provide information about the nature of the bound antigen that, when combined with a method for predicting the number of direct antibody antigen contacts, allows the discrimination between protein and non-protein binding antibodies with an accuracy of 76%. This is of relevance in several aspects of antibody science, for example to select the framework to be used for a combinatorial antibody library.
Jeong, Hyunseok; Ralph, Timothy C.
2007-10-15
We study characteristics of superpositions and entanglement of thermal states at high temperatures and discuss their applications to quantum-information processing. We introduce thermal-state qubits and thermal-Bell states, which are a generalization of pure-state qubits and Bell states to thermal mixtures. A scheme is then presented to discriminate between the four thermal-Bell states without photon number resolving detection but with Kerr nonlinear interactions and two single-photon detectors. This enables one to perform quantum teleportation and gate operations for quantum computation with thermal-state qubits.
Cognitive Analytics Driven Personalized Learning
ERIC Educational Resources Information Center
Gudivada, Venkat N.
2017-01-01
Various types of structured data collected by learning management systems such as Moodle have been used to improve student learning outcomes. Learning analytics refers to an assortment of data analysis methods used for this task. These methods typically do not consider unstructured data such as blogs, discussions, e-mail, and course messages.…
Multimedia Analysis plus Visual Analytics = Multimedia Analytics
Chinchor, Nancy; Thomas, James J.; Wong, Pak C.; Christel, Michael; Ribarsky, Martin W.
2010-10-01
Multimedia analysis has focused on images, video, and to some extent audio and has made progress in single channels excluding text. Visual analytics has focused on the user interaction with data during the analytic process plus the fundamental mathematics and has continued to treat text as did its precursor, information visualization. The general problem we address in this tutorial is the combining of multimedia analysis and visual analytics to deal with multimedia information gathered from different sources, with different goals or objectives, and containing all media types and combinations in common usage.
Wang, Xiaogang; Zhao, Daomu
2013-09-01
A nonlinear color and grayscale images cryptosystem based on phase-truncated fractional Fourier transform and optical superposition principle is proposed. In order to realize simultaneous encryption of color and grayscale images, each grayscale image is first converted into two phase masks by using an optical coherent superposition, one of which is treated as a part of input information that will be fractional Fourier transformed while the other in the form of a chaotic random phase mask (CRPM) is used as a decryption key. For the purpose of optical performance, all the processes are performed through three channels, i.e., red, green, and blue. Different from most asymmetric encryption methods, the decryption process is designed to be linear for the sake of effective decryption. The encryption level of a double random phase encryption based on phase-truncated Fourier transform is enhanced by extending it into fractional Fourier domain and the load of the keys management and transmission is lightened by using CRPMs. The security of the proposed cryptosystem is discussed and computer simulation results are presented to verify the validity of the proposed method.
NASA Technical Reports Server (NTRS)
Abdallah, Ayman A.; Barnett, Alan R.; Ibrahim, Omar M.; Manella, Richard T.
1993-01-01
Within the MSC/NASTRAN DMAP (Direct Matrix Abstraction Program) module TRD1, solving physical (coupled) or modal (uncoupled) transient equations of motion is performed using the Newmark-Beta or mode superposition algorithms, respectively. For equations of motion with initial conditions, only the Newmark-Beta integration routine has been available in MSC/NASTRAN solution sequences for solving physical systems and in custom DMAP sequences or alters for solving modal systems. In some cases, one difficulty with using the Newmark-Beta method is that the process of selecting suitable integration time steps for obtaining acceptable results is lengthy. In addition, when very small step sizes are required, a large amount of time can be spent integrating the equations of motion. For certain aerospace applications, a significant time savings can be realized when the equations of motion are solved using an exact integration routine instead of the Newmark-Beta numerical algorithm. In order to solve modal equations of motion with initial conditions and take advantage of efficiencies gained when using uncoupled solution algorithms (like that within TRD1), an exact mode superposition method using MSC/NASTRAN DMAP has been developed and successfully implemented as an enhancement to an existing coupled loads methodology at the NASA Lewis Research Center.
NASA Technical Reports Server (NTRS)
Roychoudhuri, Chandrasekhar; Prasad, Narasimha S.; Peng, Qing
2007-01-01
Any superposition effect as measured (SEM) by us is the summation of simultaneous stimulations experienced by a detector due to the presence of multiple copies of a detectee each carrying different values of the same parameter. We discus the cases with light beams carrying same frequency for both diffraction and multiple beam Fabry-Perot interferometer and also a case where the two superposed light beams carry different frequencies. Our key argument is that if light really consists of indivisible elementary particle, photon, then it cannot by itself create superposition effect since the state vector of an elementary particle cannot carry more than one values of any parameter at the same time. Fortunately, semiclassical model explains all light induced interactions using quantized atoms and classical EM wave packet. Classical physics, with its deeper commitment to Reality Ontology, was better prepared to nurture the emergence of Quantum Mechanics and still can provide guidance to explore nature deeper if we pay careful attention to successful classical formulations like Huygens-Fresnel diffraction integral.
Analytical solution of the problem of the rise of a Taylor bubble
NASA Astrophysics Data System (ADS)
Zudin, Yuri B.
2013-05-01
In the classical works of Prandtl and Taylor devoted to the analysis of the problem of the rise of a Taylor bubble in a round tube, a solution of the Laplace equation is used, which contains divergent infinite series. The present paper outlines a method for the correct analysis of the mentioned problem. Using the method of superposition of "elementary flows," a solution was obtained for flow of an ideal fluid over a body of revolution in a pipe. Satisfying the free surface condition in the vicinity of the stagnation point and using the limiting transition with respect to the main parameter lead to the relation for the rise velocity of a Taylor bubble expressed in terms of the Froude number. In order to validate the method of superposition, it was applied to the problem of the rise of a plane Taylor bubble in a flat gap, which also has an exact analytical solution obtained with the help of the complex variable theory.
Exact analytical solutions for ADAFs
NASA Astrophysics Data System (ADS)
Habibi, Asiyeh; Abbassi, Shahram; Shadmehri, Mohsen
2017-02-01
We obtain two-dimensional exact analytic solutions for the structure of the hot accretion flows without wind. We assume that the only non-zero component of the stress tensor is Trϕ. Furthermore, we assume that the value of viscosity coefficient α varies with θ. We find radially self-similar solutions and compare them with the numerical and the analytical solutions already studied in the literature. The no-wind solution obtained in this paper may be applied to the nuclei of some cool-core clusters.
Analyticity without Differentiability
ERIC Educational Resources Information Center
Kirillova, Evgenia; Spindler, Karlheinz
2008-01-01
In this article we derive all salient properties of analytic functions, including the analytic version of the inverse function theorem, using only the most elementary convergence properties of series. Not even the notion of differentiability is required to do so. Instead, analytical arguments are replaced by combinatorial arguments exhibiting…
NASA Astrophysics Data System (ADS)
Song, Qing-Wen; Zhang, Yu-Ming; Zhang, Yi-Men; Lü, Hong-Liang; Chen, Feng-Ping; Zheng, Qing-Li
2009-12-01
A new analytical model for reverse characteristics of 4H-SiC merged PN-Schottky diodes (MPS or JBS) is developed. To accurately calculate the reverse characteristics of the 4H-SiC MPS diode, the relationship between the electric field at the Schottky contact and the reverse bias is analytically established by solving the cylindrical Poisson equation after the channel has pinched off. The reverse current density calculated from the Wentzel-Kramers-Brillouin (WKB) theory is verified by comparing it with the experimental result, showing that they are in good agreement with each other. Moreover, the effects of P-region spacing (S) and P-junction depth (Xj) on the characteristics of 4H-SiC MPS are analysed, and are particularly useful for optimizing the design of the high voltage MPS diodes.
NASA Astrophysics Data System (ADS)
Boubaker, K.; Bhrawy, A. H.
2012-03-01
In this paper, Bonnor-Ebert gas sphere model of polytropic stars has been investigated through an analytical approach. Two confirmed and well-established methods have been used: the Enhanced Lagrangian Formulation Method ELFM and the Boubaker Polynomials Expansion Scheme BPES. Solutions to the related generalized Lane-Emden equation of the second kind have been expressed and plotted. Results have given evidence to the relevance of the dimensionless Bonnor-Ebert radius, in good agreement with some recently proposed profiles.
NASA Astrophysics Data System (ADS)
Setar, Katherine Marie
1997-08-01
This dissertation analytically and critically examines composer Pauline Oliveros's philosophy of 'listening' as it applies to selected works created between 1961 and 1984. The dissertation is organized through the application of two criteria: three perspectives of listening (empirical, phenomenal, and, to a lesser extent, personal), and categories derived, in part, from her writings and interviews (improvisational, traditional, theatrical, electronic, meditational, and interactive). In general, Oliveros's works may be categorized by one of two listening perspectives. The 'empirical' listening perspective, which generally includes pure acoustic phenomenon, independent from human interpretation, is exemplified in the analyses of Sound Patterns (1961), OH HA AH (1968), and, to a lesser extent, I of IV (1966). The 'phenomenal' listening perspective, which involves the human interaction with the pure acoustic phenomenon, includes a critical examination of her post-1971 'meditation' pieces and an analytical and critical examination of her tonal 'interactive' improvisations in highly resonant space, such as Watertank Software (1984). The most pervasive element of Oliveros's stylistic evolution is her gradual change from the hierarchical aesthetic of the traditional composer, to one in which creative control is more equally shared by all participants. Other significant contributions by Oliveros include the probable invention of the 'meditation' genre, an emphasis on the subjective perceptions of musical participants as a means to greater musical awareness, her musical exploration of highly resonant space, and her pioneering work in American electronic music. Both analytical and critical commentary were applied to selective representative works from Oliveros's six compositional categories. The analytical methods applied to the Oliveros's works include Wayne Slawson's vowel/formant theory as described in his book, Sound Color, an original method of categorizing consonants as
2010-04-01
Journal of Supply Chain Management , Vol. 4, No. 4. pp. 7-27. [21] Ellram, L. M. (1996): The use of the case study method in logistics research. Journal ...analytical support as quality assurance. For managers of CD&E, it is necessary to be able to state that scarce resources are being used to develop the...right concept. For managers , concept developers and experimenters, it is necessary to be able to state that the scarce recourses are being used to
Big Data Analytics in Healthcare.
Belle, Ashwin; Thiagarajan, Raghuram; Soroushmehr, S M Reza; Navidi, Fatemeh; Beard, Daniel A; Najarian, Kayvan
2015-01-01
The rapidly expanding field of big data analytics has started to play a pivotal role in the evolution of healthcare practices and research. It has provided tools to accumulate, manage, analyze, and assimilate large volumes of disparate, structured, and unstructured data produced by current healthcare systems. Big data analytics has been recently applied towards aiding the process of care delivery and disease exploration. However, the adoption rate and research development in this space is still hindered by some fundamental problems inherent within the big data paradigm. In this paper, we discuss some of these major challenges with a focus on three upcoming and promising areas of medical research: image, signal, and genomics based analytics. Recent research which targets utilization of large volumes of medical data while combining multimodal data from disparate sources is discussed. Potential areas of research within this field which have the ability to provide meaningful impact on healthcare delivery are also examined.
Big Data Analytics in Healthcare
Belle, Ashwin; Thiagarajan, Raghuram; Soroushmehr, S. M. Reza; Navidi, Fatemeh; Beard, Daniel A.; Najarian, Kayvan
2015-01-01
The rapidly expanding field of big data analytics has started to play a pivotal role in the evolution of healthcare practices and research. It has provided tools to accumulate, manage, analyze, and assimilate large volumes of disparate, structured, and unstructured data produced by current healthcare systems. Big data analytics has been recently applied towards aiding the process of care delivery and disease exploration. However, the adoption rate and research development in this space is still hindered by some fundamental problems inherent within the big data paradigm. In this paper, we discuss some of these major challenges with a focus on three upcoming and promising areas of medical research: image, signal, and genomics based analytics. Recent research which targets utilization of large volumes of medical data while combining multimodal data from disparate sources is discussed. Potential areas of research within this field which have the ability to provide meaningful impact on healthcare delivery are also examined. PMID:26229957
Science and Technology Text Mining: Analytical Chemistry
2001-01-01
mainly) from analytical chemistry, will be presented. KEYWORDS: text mining; information retrieval; bibliometrics ; computational linguistics; information...analytical chemistry, will be presented. 15. SUBJECT TERMS text mining; information retrieval; bibliometrics ; computational linguistics; information...records. Our definition includes three components: 1) Bibliometrics ; 2) Computational Linguistics; 3) Clustering. For multi-field structured records
Culture-Sensitive Functional Analytic Psychotherapy
ERIC Educational Resources Information Center
Vandenberghe, L.
2008-01-01
Functional analytic psychotherapy (FAP) is defined as behavior-analytically conceptualized talk therapy. In contrast to the technique-oriented educational format of cognitive behavior therapy and the use of structural mediational models, FAP depends on the functional analysis of the moment-to-moment stream of interactions between client and…
An analytic Pade-motivated QCD coupling
Martinez, H. E.; Cvetic, G.
2010-08-04
We consider a modification of the Minimal Analytic (MA) coupling of Shirkov and Solovtsov. This modified MA (mMA) coupling reflects the desired analytic properties of the space-like observables. We show that an approximation by Dirac deltas of its discontinuity function {rho} is equivalent to a Pade(rational) approximation of the mMA coupling that keeps its analytic structure. We propose a modification to mMA that, as preliminary results indicate, could be an improvement in the evaluation of low-energy observables compared with other analytic couplings.
Coherent pulsed excitation of degenerate multistate systems: Exact analytic solutions
Kyoseva, E. S.; Vitanov, N. V.
2006-02-15
We show that the solution of a multistate system composed of N degenerate lower (ground) states and one upper (excited) state can be reduced by using the Morris-Shore transformation to the solution of a two-state system involving only the excited state and a (bright) superposition of ground states. In addition, there are N-1 dark states composed of ground states. We use this decomposition to derive analytical solutions for degenerate extensions of the most popular exactly soluble models: the resonance solution, the Rabi, Landau-Zener, Rosen-Zener, Allen-Eberly, and Demkov-Kunike models. We suggest various applications of the multistate solutions, for example, as tools for creating multistate coherent superpositions by generalized resonant {pi} pulses. We show that such generalized {pi} pulses can occur even when the upper state is far off resonance, at specific detunings, which makes it possible to operate in the degenerate ground-state manifold without populating the (possibly lossy) upper state, even transiently.
NASA Astrophysics Data System (ADS)
Zaima, Kazunori; Akashi, Haruaki; Sasaki, Koichi
2016-01-01
The objective of this work is to understand the mechanism of plasma-assisted combustion in a steady-state premixed burner flame. We examined the spatiotemporal variation of the density of atomic oxygen in a premixed burner flame with the superposition of dielectric barrier discharge (DBD). We also measured the spatiotemporal variations of the optical emission intensities of Ar and OH. The experimental results reveal that atomic oxygen produced in the preheating zone by electron impact plays a key role in the activation of combustion reactions. This understanding is consistent with that described in our previous paper indicating that the production of “cold OH(A2Σ+)” via CHO + O → OH(A2Σ+) + CO has the sensitive response to the pulsed current of DBD [K. Zaima and K. Sasaki, Jpn. J. Appl. Phys. 53, 110309 (2014)].
Gerrits, Thomas; Glancy, Scott; Clement, Tracy S.; Calkins, Brice; Lita, Adriana E.; Nam, Sae Woo; Mirin, Richard P.; Knill, Emanuel; Miller, Aaron J.; Migdall, Alan L.
2010-09-15
We have created heralded coherent-state superpositions (CSSs) by subtracting up to three photons from a pulse of squeezed vacuum light. To produce such CSSs at a sufficient rate, we used our high-efficiency photon-number-resolving transition edge sensor to detect the subtracted photons. This experiment is enabled by and utilizes the full photon-number-resolving capabilities of this detector. The CSS produced by three-photon subtraction had a mean-photon number of 2.75{sub -0.24}{sup +0.06} and a fidelity of 0.59{sub -0.14}{sup +0.04} with an ideal CSS. This confirms that subtracting more photons results in higher-amplitude CSSs.
NASA Astrophysics Data System (ADS)
Huang, Li; Guo, Qin; Jiang, Li-ying; Chen, Ge; Xu, Xue-xiang; Yuan, Wen
2015-08-01
We introduce a new non-Gaussian state (MCSO-OSCS), generated by m times coherent superposition operation acos θ + a †sin θ (MCSO) on odd-Schrődinger-cat state | α 0> - | - α 0>(OSCS), whose normalized constant is shown to be related to Hermite polynomials. We investigate the nonclassical properties of the MCSO-OSCS through Mandel's Q-parameter, quadrature squeezing, the photocount distribution and Wigner function (WF), which is turned out to be influenced by parameters m, θ and α 0. Especially the volume of negative region of WF could increase through controlling the parameters m, θ and α 0. We also investigate the decoherence of the MCSO-OSCS in terms of the fadeaway of the negativity of WF in a thermal environment.
An analytical model of flagellate hydrodynamics
NASA Astrophysics Data System (ADS)
Dölger, Julia; Bohr, Tomas; Andersen, Anders
2017-04-01
Flagellates are unicellular microswimmers that propel themselves using one or several beating flagella. We consider a hydrodynamic model of flagellates and explore the effect of flagellar arrangement and beat pattern on swimming kinematics and near-cell flow. The model is based on the analytical solution by Oseen for the low Reynolds number flow due to a point force outside a no-slip sphere. The no-slip sphere represents the cell and the point force a single flagellum. By superposition we are able to model a freely swimming flagellate with several flagella. For biflagellates with left–right symmetric flagellar arrangements we determine the swimming velocity, and we show that transversal forces due to the periodic movements of the flagella can promote swimming. For a model flagellate with both a longitudinal and a transversal flagellum we determine radius and pitch of the helical swimming trajectory. We find that the longitudinal flagellum is responsible for the average translational motion whereas the transversal flagellum governs the rotational motion. Finally, we show that the transversal flagellum can lead to strong feeding currents to localized capture sites on the cell surface.
Analytic wave model of Stark deceleration dynamics
Gubbels, Koos; Meijer, Gerard; Friedrich, Bretislav
2006-06-15
Stark deceleration relies on time-dependent inhomogeneous electric fields which repetitively exert a decelerating force on polar molecules. Fourier analysis reveals that such fields, generated by an array of field stages, consist of a superposition of partial waves with well-defined phase velocities. Molecules whose velocities come close to the phase velocity of a given wave get a ride from that wave. For a square-wave temporal dependence of the Stark field, the phase velocities of the waves are found to be odd-fraction multiples of a fundamental phase velocity {lambda}/{tau}, with {lambda} and {tau} the spatial and temporal periods of the field. Here we study explicitly the dynamics due to any of the waves as well as due to their mutual perturbations. We first solve the equations of motion for the case of single-wave interactions and exploit their isomorphism with those for the biased pendulum. Next we analyze the perturbations of the single-wave dynamics by other waves and find that these have no net effect on the phase stability of the acceleration or deceleration process. Finally, we find that a packet of molecules can also ride a wave which results from an interference of adjacent waves. In this case, small phase stability areas form around phase velocities that are even-fraction multiples of the fundamental velocity. A detailed comparison with classical trajectory simulations and with experiment demonstrates that the analytic 'wave model' encompasses all the longitudinal physics encountered in a Stark decelerator.
Analytical prediction of aerospace vehicle vibration environments
NASA Technical Reports Server (NTRS)
Wilby, J. F.; Piersol, A. G.
1981-01-01
Considerable attention has been given recently to the formulation and validation of analytical models for the prediction of aerospace vehicle vibration response to acoustic and fluctuating pressures. This paper summarizes the development of such analytical models for two applications, (1) structural vibrations of the Space Shuttle orbiter vehicle due to broadband rocket noise and aerodynamic boundary layer turbulence, and (2) structural vibrations of general aviation aircraft due to discrete frequency propeller and reciprocating engine exhaust noise. In both cases, the spatial exterior excitations are convected pressure fields which are described on the basis of measured cross spectra (coherence and phase) information. Structural modal data are obtained from analytical predictions, and structural responses to appropriate excitation fields are calculated. The results are compared with test data, and the strengths and weaknesses of the analytical models are assessed.
A new method for constructing analytic elements for groundwater flow.
NASA Astrophysics Data System (ADS)
Strack, O. D.
2007-12-01
The analytic element method is based upon the superposition of analytic functions that are defined throughout the infinite domain, and can be used to meet a variety of boundary conditions. Analytic elements have been use successfully for a number of problems, mainly dealing with the Poisson equation (see, e.g., Theory and Applications of the Analytic Element Method, Reviews of Geophysics, 41,2/1005 2003 by O.D.L. Strack). The majority of these analytic elements consists of functions that exhibit jumps along lines or curves. Such linear analytic elements have been developed also for other partial differential equations, e.g., the modified Helmholz equation and the heat equation, and were constructed by integrating elementary solutions, the point sink and the point doublet, along a line. This approach is limiting for two reasons. First, the existence is required of the elementary solutions, and, second, the integration tends to limit the range of solutions that can be obtained. We present a procedure for generating analytic elements that requires merely the existence of a harmonic function with the desired properties; such functions exist in abundance. The procedure to be presented is used to generalize this harmonic function in such a way that the resulting expression satisfies the applicable differential equation. The approach will be applied, along with numerical examples, for the modified Helmholz equation and for the heat equation, while it is noted that the method is in no way restricted to these equations. The procedure is carried out entirely in terms of complex variables, using Wirtinger calculus.
Yoshinari, Tomoya; Sakuda, Shohei; Furihata, Kazuo; Furusawa, Hiroko; Ohnishi, Takahiro; Sugita-Konishi, Yoshiko; Ishizaki, Naoto; Terajima, Jun
2014-02-05
Trichothecene mycotoxins such as nivalenol and deoxynivalenol frequently contaminate foodstuffs. Recently, several trichothecene glucosides have been found in trichothecene-contaminated foods, and information about their chemistry, toxicity, and occurrence is required. In this study, a glucoside of nivalenol was isolated from nivalenol-contaminated wheat and was identified as nivalenol-3-O-β-D-glucopyranoside. Analytical methods using a multifunctional column or an immunoaffinity column have been developed for the simultaneous determination of nivalenol, nivalenol-3-O-β-D-glucopyranoside, deoxynivalenol, and deoxynivalenol-3-O-β-D-glucopyranoside in wheat. The methods were validated in a single laboratory, and recovery from wheat samples spiked at four levels ranged between 86.4 and 103.5% for the immunoaffinity column cleanup. These mycotoxins in contaminated wheat samples were quantitated by the validated method. Nivalenol-3-O-β-D-glucopyranoside was detected in the nivalenol-contaminated wheat, and the percentage of nivalenol-3-O-β-D-glucopyranoside to nivalenol ranged from 12 to 27%. This result indicates that the analytical method developed in this study is useful for obtaining data concerning the state and level of food contamination by nivalenol, deoxynivalenol, and their glucosides.
Analytical Chemistry in Russia.
Zolotov, Yuri
2016-09-06
Research in Russian analytical chemistry (AC) is carried out on a significant scale, and the analytical service solves practical tasks of geological survey, environmental protection, medicine, industry, agriculture, etc. The education system trains highly skilled professionals in AC. The development and especially manufacturing of analytical instruments should be improved; in spite of this, there are several good domestic instruments and other satisfy some requirements. Russian AC has rather good historical roots.
Science Update: Analytical Chemistry.
ERIC Educational Resources Information Center
Worthy, Ward
1980-01-01
Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)
NASA Astrophysics Data System (ADS)
Imai, Hiroshi; Shima, Tomohiro; Sutoh, Kazuo; Walker, Matthew L.; Knight, Peter J.; Kon, Takahide; Burgess, Stan A.
2015-09-01
Cytoplasmic dynein is a dimeric AAA+ motor protein that performs critical roles in eukaryotic cells by moving along microtubules using ATP. Here using cryo-electron microscopy we directly observe the structure of Dictyostelium discoideum dynein dimers on microtubules at near-physiological ATP concentrations. They display remarkable flexibility at a hinge close to the microtubule binding domain (the stalkhead) producing a wide range of head positions. About half the molecules have the two heads separated from one another, with both leading and trailing motors attached to the microtubule. The other half have the two heads and stalks closely superposed in a front-to-back arrangement of the AAA+ rings, suggesting specific contact between the heads. All stalks point towards the microtubule minus end. Mean stalk angles depend on the separation between their stalkheads, which allows estimation of inter-head tension. These findings provide a structural framework for understanding dynein's directionality and unusual stepping behaviour.
Imai, Hiroshi; Shima, Tomohiro; Sutoh, Kazuo; Walker, Matthew L.; Knight, Peter J.; Kon, Takahide; Burgess, Stan A.
2015-01-01
Cytoplasmic dynein is a dimeric AAA+ motor protein that performs critical roles in eukaryotic cells by moving along microtubules using ATP. Here using cryo-electron microscopy we directly observe the structure of Dictyostelium discoideum dynein dimers on microtubules at near-physiological ATP concentrations. They display remarkable flexibility at a hinge close to the microtubule binding domain (the stalkhead) producing a wide range of head positions. About half the molecules have the two heads separated from one another, with both leading and trailing motors attached to the microtubule. The other half have the two heads and stalks closely superposed in a front-to-back arrangement of the AAA+ rings, suggesting specific contact between the heads. All stalks point towards the microtubule minus end. Mean stalk angles depend on the separation between their stalkheads, which allows estimation of inter-head tension. These findings provide a structural framework for understanding dynein's directionality and unusual stepping behaviour. PMID:26365535
NASA Astrophysics Data System (ADS)
Li, Bo; Wang, San-Min; Zhi, Chang-Jian; Xue, Xiang-Zhen; Makis, Viliam
2017-01-01
This paper aims at investigating the buckling load of fully deployed linear array deployable structure based on scissor-like element (SLE) under its own weight. The deployable structure has been widely researched both in geometric configurations and structural dynamic characteristics. However, when the number of elements or degree of deployment exceeds the predetermined range, even if there is no external load, deployable structure will automatically collapse under its own weight. To address this issue, this paper derives a new stability model based on linear elastic analysis and energy method to compute the buckling load caused by its own weight for avoiding the structural instability, which can be applied to a linear array deployable structure with n SLEs. In the process of calculation, the first SLE is taken for mechanical analysis and the results are extended to any unit. In the sequel of this process, the scissor deployable structure is equivalent to a uniform solid column and its buckling condition under self-weight is obtained based on the principle of potential energy. Also, the effect of various parameters that affect the instability of the structure, such as the number of elements, bar length and degree of deployment is investigated, and the results of the theoretical analysis are verified through a comparison with the simulation results in ANSYS, which show that the new stability model proposed here can predict the buckling load of scissor deployable structure.
Superposition of fiber Bragg and LPG gratings for embedded strain measurement
NASA Astrophysics Data System (ADS)
Guyard, Romain; Leduc, Dominique; Lecieux, Yann; Lupi, Cyril
2016-11-01
When a fiber Bragg grating strain sensor is embedded inside a structure, the interaction of the sensor with the host material can lead to spurious results if the radial strain is neglected. In this article, we use numerical simulations to show that the axial and radial strains can be simultaneously measured with a single fiber in which a Bragg grating and a long-period grating are superimposed. Moreover, we present an optimal architecture of the sensor.
NASA Astrophysics Data System (ADS)
Zhu, Zhang-Ming; Li, Ru; Hao, Bao-Tian; Yang, Yin-Tang
2009-11-01
Based on the heat diffusion equation of multilevel interconnects, a novel analytical thermal model for multilevel nano-scale interconnects considering the via effect is presented, which can compute quickly the temperature of multilevel interconnects, with substrate temperature given. Based on the proposed model and the 65 nm complementary metal oxide semiconductor (CMOS) process parameter, the temperature of nano-scale interconnects is computed. The computed results show that the via effect has a great effect on local interconnects, but the reduction of thermal conductivity has little effect on local interconnects. With the reduction of thermal conductivity or the increase of current density, however, the temperature of global interconnects rises greatly, which can result in a great deterioration in their performance. The proposed model can be applied to computer aided design (CAD) of very large-scale integrated circuits (VLSIs) in nano-scale technologies.
Separable metamaterials: analytical ab-initio homogenization and chirality
NASA Astrophysics Data System (ADS)
Ciattoni, Alessandro; Rago, Domenico; Rizza, Carlo
2016-11-01
We investigate the ab-initio homogenization of separable metamaterials with factorized dielectric permittivity profiles, which can be achieved through suitable grey-scale permittivity design techniques. Separability allows such metamaterials to be physically regarded as the superposition of three fictitious 1D generating media. We prove that, in the long-wavelength limit, separable metamaterials admit a simple and analytical description of their electromagnetic bi-anisotropic response, which can be reconstructed from the properties of the 1D generating media. Our approach provides a strategy that allows the full ab-initio and flexible design of a complex bianisotropic response by using the simple and well-known properties of 1D metamaterials.
Signals: Applying Academic Analytics
ERIC Educational Resources Information Center
Arnold, Kimberly E.
2010-01-01
Academic analytics helps address the public's desire for institutional accountability with regard to student success, given the widespread concern over the cost of higher education and the difficult economic and budgetary conditions prevailing worldwide. Purdue University's Signals project applies the principles of analytics widely used in…
Extreme Scale Visual Analytics
Wong, Pak C.; Shen, Han-Wei; Pascucci, Valerio
2012-05-08
Extreme-scale visual analytics (VA) is about applying VA to extreme-scale data. The articles in this special issue examine advances related to extreme-scale VA problems, their analytical and computational challenges, and their real-world applications.
Learning Analytics Considered Harmful
ERIC Educational Resources Information Center
Dringus, Laurie P.
2012-01-01
This essay is written to present a prospective stance on how learning analytics, as a core evaluative approach, must help instructors uncover the important trends and evidence of quality learner data in the online course. A critique is presented of strategic and tactical issues of learning analytics. The approach to the critique is taken through…
Not Available
1990-01-01
This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)
Analytical mass spectrometry. Abstracts
Not Available
1990-12-31
This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)
ERIC Educational Resources Information Center
Ember, Lois R.
1977-01-01
The procedures utilized by the Association of Official Analytical Chemists (AOAC) to develop, evaluate, and validate analytical methods for the analysis of chemical pollutants are detailed. Methods validated by AOAC are used by the EPA and FDA in their enforcement programs and are granted preferential treatment by the courts. (BT)
Quo vadis, analytical chemistry?
Valcárcel, Miguel
2016-01-01
This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed.
A receptor model for tumor promoters: rational superposition of teleocidins and phorbol esters.
Itai, A; Kato, Y; Tomioka, N; Iitaka, Y; Endo, Y; Hasegawa, M; Shudo, K; Fujiki, H; Sakai, S
1988-01-01
Four 12-O-tetradecanoyl-13-O-acetylphorbol-type tumor promoters--teleocidin, phorbol ester, aplysiatoxin, and ingenol ester--are superposed in an attempt to understand their common biological activity on the assumption that they may bind to the same receptor site. A method using three-dimensional computer graphics was applied for superposing molecules and receptor mapping. The main feature of the method is that molecules are superposed in terms of spatial arrangement of physical and chemical properties but not in terms of the atomic positions as in conventional methods. This led to successful extraction of common structural features required for potent tumor-promoting activity: two hydrogen donors, a hydrogen acceptor, and a large lipophilic group. Their mutual spatial arrangements are most important for biological activity. Images PMID:3131760
Analytical solutions of the Dirac equation under Hellmann-Frost-Musulin potential
NASA Astrophysics Data System (ADS)
Onate, C. A.; Onyeaju, M. C.; Ikot, A. N.
2016-12-01
The approximate analytical solutions of the Dirac equation with Hellmann-Frost-Musulin potential have been studied by using the generalized parametric Nikiforov-Uvarov (NU) method for arbitrary spin-orbit quantum number k under the spin and pseudospin symmetries. The Hellmann-Frost-Musulin potential is a superposition potential that consists of Yukawa potential, Coulomb potential, and Frost-Musulin potential. As a particular case, we found the energy levels of the non-relativistic limit of the spin symmetry. The energy equation of Yukawa potential, Coulomb potential, Hellmann potential and Frost-Musulin potential are obtained. Energy values are generated for some diatomic molecules.
NASA Astrophysics Data System (ADS)
Russo, G.; Attili, A.; Battistoni, G.; Bertrand, D.; Bourhaleb, F.; Cappucci, F.; Ciocca, M.; Mairani, A.; Milian, F. M.; Molinelli, S.; Morone, M. C.; Muraro, S.; Orts, T.; Patera, V.; Sala, P.; Schmitt, E.; Vivaldo, G.; Marchetto, F.
2016-01-01
The calculation algorithm of a modern treatment planning system for ion-beam radiotherapy should ideally be able to deal with different ion species (e.g. protons and carbon ions), to provide relative biological effectiveness (RBE) evaluations and to describe different beam lines. In this work we propose a new approach for ion irradiation outcomes computations, the beamlet superposition (BS) model, which satisfies these requirements. This model applies and extends the concepts of previous fluence-weighted pencil-beam algorithms to quantities of radiobiological interest other than dose, i.e. RBE- and LET-related quantities. It describes an ion beam through a beam-line specific, weighted superposition of universal beamlets. The universal physical and radiobiological irradiation effect of the beamlets on a representative set of water-like tissues is evaluated once, coupling the per-track information derived from FLUKA Monte Carlo simulations with the radiobiological effectiveness provided by the microdosimetric kinetic model and the local effect model. Thanks to an extension of the superposition concept, the beamlet irradiation action superposition is applicable for the evaluation of dose, RBE and LET distributions. The weight function for the beamlets superposition is derived from the beam phase space density at the patient entrance. A general beam model commissioning procedure is proposed, which has successfully been tested on the CNAO beam line. The BS model provides the evaluation of different irradiation quantities for different ions, the adaptability permitted by weight functions and the evaluation speed of analitical approaches. Benchmarking plans in simple geometries and clinical plans are shown to demonstrate the model capabilities.
Russo, G; Attili, A; Battistoni, G; Bertrand, D; Bourhaleb, F; Cappucci, F; Ciocca, M; Mairani, A; Milian, F M; Molinelli, S; Morone, M C; Muraro, S; Orts, T; Patera, V; Sala, P; Schmitt, E; Vivaldo, G; Marchetto, F
2016-01-07
The calculation algorithm of a modern treatment planning system for ion-beam radiotherapy should ideally be able to deal with different ion species (e.g. protons and carbon ions), to provide relative biological effectiveness (RBE) evaluations and to describe different beam lines. In this work we propose a new approach for ion irradiation outcomes computations, the beamlet superposition (BS) model, which satisfies these requirements. This model applies and extends the concepts of previous fluence-weighted pencil-beam algorithms to quantities of radiobiological interest other than dose, i.e. RBE- and LET-related quantities. It describes an ion beam through a beam-line specific, weighted superposition of universal beamlets. The universal physical and radiobiological irradiation effect of the beamlets on a representative set of water-like tissues is evaluated once, coupling the per-track information derived from FLUKA Monte Carlo simulations with the radiobiological effectiveness provided by the microdosimetric kinetic model and the local effect model. Thanks to an extension of the superposition concept, the beamlet irradiation action superposition is applicable for the evaluation of dose, RBE and LET distributions. The weight function for the beamlets superposition is derived from the beam phase space density at the patient entrance. A general beam model commissioning procedure is proposed, which has successfully been tested on the CNAO beam line. The BS model provides the evaluation of different irradiation quantities for different ions, the adaptability permitted by weight functions and the evaluation speed of analitical approaches. Benchmarking plans in simple geometries and clinical plans are shown to demonstrate the model capabilities.
An Analytic Approach to Perturbative QCD
NASA Astrophysics Data System (ADS)
Magradze, B. A.
The two-loop invariant (running) coupling of QCD is written in terms of the Lambert W function. The analyticity structure of the coupling in the complex Q2-plane is established. The corresponding analytic coupling is reconstructed via a dispersion relation. We also consider some other approximations to the QCD β-function, when the corresponding couplings are solved in terms of the Lambert function. The Landau gauge gluon propagator has been considered in the renormalization group invariant analytic approach (IAA). It is shown that there is a nonperturbative ambiguity in determination of the anomalous dimension function of the gluon field. Several analytic solutions for the propagator at the one-loop order are constructed. Properties of the obtained analytical solutions are discussed.
Scholtz, Jean; Burtner, Edwin R.; Cook, Kristin A.
2016-06-13
This course will introduce the field of Visual Analytics to HCI researchers and practitioners highlighting the contributions they can make to this field. Topics will include a definition of visual analytics along with examples of current systems, types of tasks and end users, issues in defining user requirements, design of visualizations and interactions, guidelines and heuristics, the current state of user-centered evaluations, and metrics for evaluation. We encourage designers, HCI researchers, and HCI practitioners to attend to learn how their skills can contribute to advancing the state of the art of visual analytics
An Analytic Theory for the Orbits of Circumbinary Planets
NASA Astrophysics Data System (ADS)
Leung, Gene C. K.; Lee, Man Hoi
2013-02-01
Three transiting circumbinary planets (Kepler-16 b, Kepler-34 b, and Kepler-35 b) have recently been discovered from photometric data taken by the Kepler spacecraft. Their orbits are significantly non-Keplerian because of the large secondary-to-primary mass ratio and orbital eccentricity of the binaries, as well as the proximity of the planets to the binaries. We present an analytic theory, with the planet treated as a test particle, which shows that the planetary motion can be represented by the superposition of the circular motion of a guiding center, the forced oscillations due to the non-axisymmetric components of the binary's potential, the epicyclic motion, and the vertical motion. In this analytic theory, the periapse and ascending node of the planet precess at nearly equal rates in opposite directions. The largest forced oscillation term corresponds to a forced eccentricity (which is an explicit function of the parameters of the binary and of the guiding center radius of the planet), and the amplitude of the epicyclic motion (which is a free parameter of the theory) is the free eccentricity. Comparisons with direct numerical orbit integrations show that this analytic theory gives an accurate description of the planetary motion for all three Kepler systems. We find that all three Kepler circumbinary planets have nonzero free eccentricities.
AN ANALYTIC THEORY FOR THE ORBITS OF CIRCUMBINARY PLANETS
Leung, Gene C. K.; Lee, Man Hoi
2013-02-15
Three transiting circumbinary planets (Kepler-16 b, Kepler-34 b, and Kepler-35 b) have recently been discovered from photometric data taken by the Kepler spacecraft. Their orbits are significantly non-Keplerian because of the large secondary-to-primary mass ratio and orbital eccentricity of the binaries, as well as the proximity of the planets to the binaries. We present an analytic theory, with the planet treated as a test particle, which shows that the planetary motion can be represented by the superposition of the circular motion of a guiding center, the forced oscillations due to the non-axisymmetric components of the binary's potential, the epicyclic motion, and the vertical motion. In this analytic theory, the periapse and ascending node of the planet precess at nearly equal rates in opposite directions. The largest forced oscillation term corresponds to a forced eccentricity (which is an explicit function of the parameters of the binary and of the guiding center radius of the planet), and the amplitude of the epicyclic motion (which is a free parameter of the theory) is the free eccentricity. Comparisons with direct numerical orbit integrations show that this analytic theory gives an accurate description of the planetary motion for all three Kepler systems. We find that all three Kepler circumbinary planets have nonzero free eccentricities.
Technology Transfer Automated Retrieval System (TEKTRAN)
The structural assemblage of biochar is connected to the nature of feedstock and the conditions of production and has important implications to its fate in the environment. However, the relationships between the molecular characteristics of biochar and its agro/environmental behavior have not been f...
ERIC Educational Resources Information Center
Jordan, Michael P.
1980-01-01
This discussion of information structures in written texts describes how linguistic analysis of short published reports leads to the presentation of an algorithm that depicts the problem-solving process in terms of a series of evaluative questions. (Author/CHC)
Analytical techniques: A compilation
NASA Technical Reports Server (NTRS)
1975-01-01
A compilation, containing articles on a number of analytical techniques for quality control engineers and laboratory workers, is presented. Data cover techniques for testing electronic, mechanical, and optical systems, nondestructive testing techniques, and gas analysis techniques.
Correction of the basis set superposition error in SCF and MP2 interaction energies. The water dimer
NASA Astrophysics Data System (ADS)
Szcześniak, M. M.; Scheiner, Steve
1986-06-01
There has been some discussion concerning whether basis set superposition error is more correctly evaluated using the full set of ghost orbitals of the partner molecule or some subset thereof. A formal treatment is presented, arguing that the full set is required at the Møller-Plesset level. Numerical support for this position is provided by calculation of the interaction energy between a pair of water molecules, using a series of moderate sized basis sets ranging from 6-31G** to the [432/21] contraction suggested by Clementi and Habitz. These energies, at both the SCF and MP2 levels, behave erratically with respect to changes in details of the basis set, e.g., H p-function exponent. On the other hand, after counterpoise correction using the full set of partner ghost orbitals, the interaction energies are rather insensitive to basis set and behave in a manner consistent with calculated monomer properties. For long intersystem separations, the contribution of correlation to the interaction is repulsive despite the attractive influence of dispersion. This effect is attributed to partial account of intrasystem correlation and can be approximated at long distances via electrostatic terms linear in MP2-induced changes in the monomer moments.
NASA Astrophysics Data System (ADS)
Lee, Young-Hyun; Kim, Jonghyeon; Yoo, Seungyeol
2016-09-01
The critical cell voltage drop in a stack can be followed by stack defect. A method of detecting defective cell is the cell voltage monitoring. The other methods are based on the nonlinear frequency response. In this paper, the superposition principle for the diagnosis of PEMFC stack is introduced. If critical cell voltage drops exist, the stack behaves as a nonlinear system. This nonlinearity can explicitly appear in the ohmic overpotential region of a voltage-current curve. To detect the critical cell voltage drop, a stack is excited by two input direct test-currents which have smaller amplitude than an operating stack current and have an equal distance value from the operating current. If the difference between one voltage excited by a test current and the voltage excited by a load current is not equal to the difference between the other voltage response and the voltage excited by the load current, the stack system acts as a nonlinear system. This means that there is a critical cell voltage drop. The deviation from the value zero of the difference reflects the grade of the system nonlinearity. A simulation model for the stack diagnosis is developed based on the SPP, and experimentally validated.
NASA Astrophysics Data System (ADS)
Van Houteghem, Marc; Verstraelen, Toon; Ghysels, An; Vanduyfhuys, Louis; Waroquier, Michel; Van Speybroeck, Veronique
2012-09-01
An efficient protocol is presented to compensate for the basis set superposition error (BSSE) in DFT molecular dynamics (MD) simulations using localized Gaussian basis sets. We propose a classical correction term that can be added a posteriori to account for BSSE. It is tested to what extension this term will improve radial distribution functions (RDFs). The proposed term is pairwise between certain atoms in different molecules and was calibrated by fitting reference BSSE data points computed with the counterpoise method. It is verified that the proposed exponential decaying functional form of the model is valid. This work focuses on hydrogen-bonded liquids, i.e., methanol, and more specific on the intermolecular hydrogen bond, but in principle the method is generally applicable on any type of interaction where BSSE is significant. We evaluated the relative importance of the Grimme-dispersion versus BSSE and found that they are of the same order of magnitude, but with an opposite sign. Upon introduction of the correction, the relevant RDFs, obtained from MD, have amplitudes equal to experiment.
Analytical Ultrasonics in Materials Research and Testing
NASA Technical Reports Server (NTRS)
Vary, A.
1986-01-01
Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.
ENVIRONMENTAL ANALYTICAL CHEMISTRY OF ...
Within the scope of a number of emerging contaminant issues in environmental analysis, one area that has received a great deal of public interest has been the assessment of the role of pharmaceuticals and personal care products (PPCPs) as stressors and agents of change in ecosystems as well as their role in unplanned human exposure. The relationship between personal actions and the occurrence of PPCPs in the environment is clear-cut and comprehensible to the public. In this overview, we attempt to examine the separations aspect of the analytical approach to the vast array of potential analytes among this class of compounds. We also highlight the relationship between these compounds and endocrine disrupting compounds (EDCs) and between PPCPs and EDCs and the more traditional environmental analytes such as the persistent organic pollutants (POPs). Although the spectrum of chemical behavior extends from hydrophobic to hydrophilic, the current focus has shifted to moderately and highly polar analytes. Thus, emphasis on HPLC and LC/MS has grown and MS/MS has become a detection technique of choice with either electrospray ionization or atmospheric pressure chemical ionization. This contrasts markedly with the bench mark approach of capillary GC, GC/MS and electron ionization in traditional environmental analysis. The expansion of the analyte list has fostered new vigor in the development of environmental analytical chemistry, modernized the range of tools appli
NASA Astrophysics Data System (ADS)
Chen, Qiang; Gorb, Stanislav; Kovalev, Alexander; Li, Zhiyong; Pugno, Nicola
2016-10-01
Feathers can fulfill their aerodynamic function only if the pennaceous vane forms an airfoil stabilized by robust interlocking between barbules. Thus, revealing the robustness of the interlocking mechanical behavior of the barbules is very important to understand the function and long-term resilience of bird feathers. This paper, basing on the small- and large-beam deflection solutions, presents a hierarchical mechanical model for deriving the critical delamination conditions of the interlocking barbules between two adjacent barbs in bird feathers. The results indicate a high robustness and flaw-tolerant design of the structure. This work contributes to the understanding of the mechanical behavior of the robust interlocking barb-barbule structure of the bird feather, and provides a basis for design of feather-inspired materials with robust interlocking mechanism, such as advanced bio-inspired micro-zipping devices.
Mader, Dieter; Koeberl, Christian
2009-12-01
The Instrumental Neutron Activation Analysis Gamma Spectroscopy Laboratory at the Department of Lithospheric Research, University of Vienna, has been upgraded in the year 2006. This paper describes the sample preparation, new instrumentation and data evaluation for hundreds of rock samples of two terrestrial impact structures. The measurement and data evaluation are done by using Genie 2000 and a custom-made batch software for the used analysis sequences.
dos, Santos Luís Augusto; Marin, Heimar de Fátima; Marques, Isaac Rosa; Cunha, Isabel Cristina Kowal Olm
2007-01-01
This work intents, in a didactic form, to explain the benefits of use of a technique of project management, named Work Breakdown Structure: a graphical tool to identify the main results to be developed in a project. The real examples are applied to a sub-project of the Virtual Library in Health in Nursing (BVS-Enfermagem) to development of the Sites Catalogs. The benefits of graphical visualization for a major agreement between professionals of different expertise are presented.
Garcia, Martín N.; Acuña, Cintia; Borralho, Nuno M. G.; Grattapaglia, Dario; Marcucci Poltri, Susana N.
2013-01-01
The promise of association genetics to identify genes or genomic regions controlling complex traits has generated a flurry of interest. Such phenotype-genotype associations could be useful to accelerate tree breeding cycles, increase precision and selection intensity for late expressing, low heritability traits. However, the prospects of association genetics in highly heterozygous undomesticated forest trees can be severely impacted by the presence of cryptic population and pedigree structure. To investigate how to better account for this, we compared the GLM and five combinations of the Unified Mixed Model (UMM) on data of a low-density genome-wide association study for growth and wood property traits carried out in a Eucalyptus globulus population (n = 303) with 7,680 Diversity Array Technology (DArT) markers. Model comparisons were based on the degree of deviation from the uniform distribution and estimates of the mean square differences between the observed and expected p-values of all significant marker-trait associations detected. Our analysis revealed the presence of population and family structure. There was not a single best model for all traits. Striking differences in detection power and accuracy were observed among the different models especially when population structure was not accounted for. The UMM method was the best and produced superior results when compared to GLM for all traits. Following stringent correction for false discoveries, 18 marker-trait associations were detected, 16 for tree diameter growth and two for lignin monomer composition (S∶G ratio), a key wood property trait. The two DArT markers associated with S∶G ratio on chromosome 10, physically map within 1 Mbp of the ferulate 5-hydroxylase (F5H) gene, providing a putative independent validation of this marker-trait association. This study details the merit of collectively integrate population structure and relatedness in association analyses in undomesticated, highly
Levy, Michaella J; Gucinski, Ashley C; Sommers, Cynthia D; Ghasriani, Houman; Wang, Bo; Keire, David A; Boyne, Michael T
2014-10-01
The FDA has approved more than 100 protein and peptide drugs with hundreds more in the pipeline (Lanthier et al. in Nat Rev Drug Discov 7(9):733-737, 2008). Many of these originator biologic products are now coming off patent and are being manufactured by alternate methods than the innovator as follow-on drugs. Because changes to the production method often lead to subtle differences (e.g., degradation products, different posttranslational modifications or impurities) in the therapeutic (Schiestl et al. in Nat Biotechnol 29(4):310-312, 2011), there is a critical need to define techniques to test and insure the quality of these drugs. In addition, the emergence of protein therapeutics manufactured by unapproved methodologies presents an ongoing and growing regulatory challenge. In this work, high-resolution mass spectrometry was used to determine the presence or absence of posttranslational modifications for one FDA-approved and three foreign-sourced, unapproved filgrastim products. Circular dichroism (CD) was used to compare the secondary structure and probe the temperature stability of these products. Native 2D (1)H,(15)N-heteronuclear singular quantum coherence (HSQC) NMR test was applied to these samples to compare the higher-order structure of the four products. Finally, a cell proliferation assay was performed on the filgrastims to compare their bioactivity, and stressed filgrastim was tested in the bioassay to better understand the effects of changes in protein structure on activity. The results showed that orthogonal approaches are capable of characterizing the physiochemical properties of this protein drug and assessing the impact of structural changes on filgrastim purity and potency.
Analytical Production and Collimation of Astrophysical Jets
NASA Astrophysics Data System (ADS)
Bernal, C. G.; Lee, W. H.
2005-09-01
The structure and evolution of jet-like structures under a variety of physical conditions is a problem that generally requires numerical modelling. However, in certain cases valuable insight can be gained from purely hydrodynamical analytical solutions which exhibit outflows of varying characteristics. We show here several solutions of this type, applicable to various accretion scenarios.
Eng, Goi Khia; Sim, Kang; Chen, Shen-Hsing Annabel
2015-05-01
Obsessive-compulsive disorder (OCD) is a debilitating disorder. However, existing neuroimaging findings involving executive function and structural abnormalities in OCD have been mixed. Here we conducted meta-analyses to investigate differences in OCD samples and controls in: Study 1 - grey matter structure; Study 2 - executive function task-related activations during (i) response inhibition, (ii) interference, and (iii) switching tasks; and Study 3 - white matter diffusivity. Results showed grey matter differences in the frontal, striatal, thalamus, parietal and cerebellar regions; task domain-specific neural differences in similar regions; and abnormal diffusivity in major white matter regions in OCD samples compared to controls. Our results reported concurrence of abnormal white matter diffusivity with corresponding abnormalities in grey matter and task-related functional activations. Our findings suggested the involvement of other brain regions not included in the cortico-striato-thalamo-cortical network, such as the cerebellum and parietal cortex, and questioned the involvement of the orbitofrontal region in OCD pathophysiology. Future research is needed to clarify the roles of these brain regions in the disorder.
Rothenbacher, Thorsten; Schwack, Wolfgang
2009-01-01
Plastic packaging materials may release compounds into packed foodstuffs. To identify potential migrants of toxicological concern, resins, and multilayer foils (mainly polyethylene) intended for the production of food contact materials were extracted and analyzed by GC/mass spectrometry. To identify even compounds of low concentrations, AMDIS software was used and data evaluation was safeguarded by the Kovats retention index (RI) system. In this way, 46 compounds were identified as possible migrants. The expert structure-activity relationship software DEREK for Windows was utilized to evaluate all identified substances in terms of carcinogenicity, genotoxicity, thyroid toxicity, and miscellaneous endpoints for humans. Additionally, a literature search for these compounds was performed with Sci-Finder, but relevant data were missing for 28 substances. Seven compounds with adverse toxicological effects were identified. In addition, the RIs of 24 commercial additive standards, measured with a GC capillary column of intermediate polarity, are given.
Advances in analytical chemistry
NASA Technical Reports Server (NTRS)
Arendale, W. F.; Congo, Richard T.; Nielsen, Bruce J.
1991-01-01
Implementation of computer programs based on multivariate statistical algorithms makes possible obtaining reliable information from long data vectors that contain large amounts of extraneous information, for example, noise and/or analytes that we do not wish to control. Three examples are described. Each of these applications requires the use of techniques characteristic of modern analytical chemistry. The first example, using a quantitative or analytical model, describes the determination of the acid dissociation constant for 2,2'-pyridyl thiophene using archived data. The second example describes an investigation to determine the active biocidal species of iodine in aqueous solutions. The third example is taken from a research program directed toward advanced fiber-optic chemical sensors. The second and third examples require heuristic or empirical models.
Competing on talent analytics.
Davenport, Thomas H; Harris, Jeanne; Shapiro, Jeremy
2010-10-01
Do investments in your employees actually affect workforce performance? Who are your top performers? How can you empower and motivate other employees to excel? Leading-edge companies such as Google, Best Buy, Procter & Gamble, and Sysco use sophisticated data-collection technology and analysis to answer these questions, leveraging a range of analytics to improve the way they attract and retain talent, connect their employee data to business performance, differentiate themselves from competitors, and more. The authors present the six key ways in which companies track, analyze, and use data about their people-ranging from a simple baseline of metrics to monitor the organization's overall health to custom modeling for predicting future head count depending on various "what if" scenarios. They go on to show that companies competing on talent analytics manage data and technology at an enterprise level, support what analytical leaders do, choose realistic targets for analysis, and hire analysts with strong interpersonal skills as well as broad expertise.
DeVoe, Robert D.
1962-01-01
Retinal action potentials were elicited from light-adapted posterior median ocelli of the wolf spider Lycosa baltimoriana (Keyserling) by rectangular shaped photic stimuli representing 8 per cent increments or decrements of the background illumination. Responses to trains of recurrent incremental or decremental flashes were successfully predicted by graphical linear superposition of a single flash response, which was repeatedly drawn and added to itself at intervals equal to the period of the intermittent stimulus. Incremental stimuli inverted to form decremental stimuli elicited responses which were also inverted. Responses to single incremental flashes were successfully predicted by linear superposition of the response to one incremental step stimulus, which was inverted and added to itself at an interval equal to the duration of the flash. PMID:13884591
NASA Astrophysics Data System (ADS)
Zhang, Zhenhua; Tian, Jin; Du, Juan
2017-02-01
We demonstrate a simple way to realize control of population transfer and creation of two orthogonal maximally superposition states in a Λ-type four-level system with closely spaced doublet target states via a pair of pump and chirped Stokes pulses. It is illustrated that the population in the initial state can be selectively, completely and robustly transferred to either of the doublet target states via chirped adiabatic passage with the suitable chirp rate and frequency detuning of the Stokes pulse. Besides, creation of two orthogonal maximally superposition states between the initial state and intermediate state with equal amplitude but inverse relative phases is also shown, which may have potential applications in the preparations of quantum bits.
Brandenburg, Jan Gerit; Alessio, Maristella; Civalleri, Bartolomeo; Peintinger, Michael F; Bredow, Thomas; Grimme, Stefan
2013-09-26
We extend the previously developed geometrical correction for the inter- and intramolecular basis set superposition error (gCP) to periodic density functional theory (DFT) calculations. We report gCP results compared to those from the standard Boys-Bernardi counterpoise correction scheme and large basis set calculations. The applicability of the method to molecular crystals as the main target is tested for the benchmark set X23. It consists of 23 noncovalently bound crystals as introduced by Johnson et al. (J. Chem. Phys. 2012, 137, 054103) and refined by Tkatchenko et al. (J. Chem. Phys. 2013, 139, 024705). In order to accurately describe long-range electron correlation effects, we use the standard atom-pairwise dispersion correction scheme DFT-D3. We show that a combination of DFT energies with small atom-centered basis sets, the D3 dispersion correction, and the gCP correction can accurately describe van der Waals and hydrogen-bonded crystals. Mean absolute deviations of the X23 sublimation energies can be reduced by more than 70% and 80% for the standard functionals PBE and B3LYP, respectively, to small residual mean absolute deviations of about 2 kcal/mol (corresponding to 13% of the average sublimation energy). As a further test, we compute the interlayer interaction of graphite for varying distances and obtain a good equilibrium distance and interaction energy of 6.75 Å and -43.0 meV/atom at the PBE-D3-gCP/SVP level. We fit the gCP scheme for a recently developed pob-TZVP solid-state basis set and obtain reasonable results for the X23 benchmark set and the potential energy curve for water adsorption on a nickel (110) surface.
Singh, Tarkeshwar; Zatsiorsky, Vladimir M.; Latash, Mark L.
2013-01-01
We investigated the effects of exercise-induced fatigue of a digit on the biomechanics of a static prehension task. The participants were divided into two groups. One group performed the fatiguing exercise using the thumb (group-thumb) and the second group performed the exercise using the index finger (group-index). We analyzed the prehensile action as being based on a two-level hierarchy. Our first hypothesis was that fatigue of the thumb would have stronger effects at the upper level (action shared between the thumb and all four fingers combined – virtual finger) and fatigue of the index finger would have stronger effects at the lower level of the hierarchy (action of the virtual finger shared among actual fingers). We also hypothesized that fatigue would cause a decrease in the normal force applied by the exercised digit and correspondingly lead to a decrease in the normal force applied by the opposing digit(s). Our third hypothesis was that fatigue would leave the tangential forces unaffected. Fatigue led to a significant drop in the normal force of both exercised and non-exercised (opposing) digits. The tangential forces of the exercised digits increased after fatigue. This led to a drop in the safety margin in the group-thumb, but not group-index. As such, the results supported the first two hypotheses but not the third hypothesis. Overall, the results suggested that fatigue triggered a chain reaction that involved both forces and moments of force produced by individual digits leading to a violation of the principle of superposition. The findings are interpreted within the framework of the referent configuration hypothesis. PMID:23322417
Saran, Amit D; Mehra, Anurag; Bellare, Jayesh R
2012-07-15
A novel theoretical model based on superposition of core and shell band-gaps, termed as SQCE model, is developed and reported here, which enables one to estimate the shell thickness in a core-shell quantum dot (QD), which is critically important in deciding its optical and electronic properties. We apply the model to two experimental core-shell QD systems, CdSe-CdS and CdSe-ZnS, which we synthesize by microemulsion method. We synthesize and study two series of samples, R and S to study the optical properties. The core size is varied in the R-series (by varying water-to-surfactant ratio, R) whereas the shell thickness is varied in the S-series (by varying the shell-to-core precursor molar ratio, S). The core and core-shell QDs from R-series and S-series are characterized for particle size, shape and crystallographic information. The shell thickness for all core-shell QD samples is estimated by SQCE model, and experimentally measured with TEM and SAXS. A close match is observed between experimental values and model predictions, thus validating the model. Further, the optimum shell thickness (corresponding to maximum quantum yield) values for CdS and ZnS over a 4.26 nm CdSe core have been estimated as 0.585 nm and 0.689 nm, respectively, from the SQCE model. The SQCE model developed in this work is applicable to other core-shell quantum dots also, such as CdTe-CdS, CdTe-CdSe and CdS-ZnS, and will serve as a useful complement to experimental measurement.
Monitoring the analytic surface.
Spence, D P; Mayes, L C; Dahl, H
1994-01-01
How do we listen during an analytic hour? Systematic analysis of the speech patterns of one patient (Mrs. C.) strongly suggests that the clustering of shared pronouns (e.g., you/me) represents an important aspect of the analytic surface, preconsciously sensed by the analyst and used by him to determine when to intervene. Sensitivity to these patterns increases over the course of treatment, and in a final block of 10 hours shows a striking degree of contingent responsivity: specific utterances by the patient are consistently echoed by the analyst's interventions.
Frontiers in analytical chemistry
Amato, I.
1988-12-15
Doing more with less was the modus operandi of R. Buckminster Fuller, the late science genius, and inventor of such things as the geodesic dome. In late September, chemists described their own version of this maxim--learning more chemistry from less material and in less time--in a symposium titled Frontiers in Analytical Chemistry at the 196th National Meeting of the American Chemical Society in Los Angeles. Symposium organizer Allen J. Bard of the University of Texas at Austin assembled six speakers, himself among them, to survey pretty widely different areas of analytical chemistry.