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Sample records for 4x4 matrix formalism

  1. Submicrosecond rearrangeable nonblocking silicon-on-insulator thermo-optic 4x4 switch matrix.

    PubMed

    Li, Yuntao; Yu, Jinzhong; Chen, Shaowu; Li, Yanping; Chen, Yuanyuan

    2007-03-15

    A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4x4 switch matrix is designed and fabricated. A spot-size converter is integrated to reduce the insertion loss, and a new driving circuit is designed to improve the response speed. The insertion loss is less than 10 dB, and the response time is 950 ns. PMID:17308574

  2. Evaluation of 4 X 4 Block Schedule.

    ERIC Educational Resources Information Center

    Mutter, Davida W.; And Others

    1997-01-01

    Describes 4 X 4 block scheduling and its advantages and disadvantages. Examines block scheduling's effects on a Virginia high school's students, teachers, and administration, based on school data and survey results. Most participants preferred block scheduling over the six-period schedule. Grades, attendance, and discipline improved; students…

  3. An Operator Formalism for Unitary Matrix Models

    NASA Astrophysics Data System (ADS)

    Anagnostopoulos, K. N.; Bowick, M. J.; Ishibashi, N.

    We analyze the double scaling limit of unitary matrix models in terms of trigonometric orthogonal polynomials on the circle. In particular we find a compact formulation of the string equation at the kth multicritical point in terms of pseudodifferential operators and a corresponding action principle. We also relate this approach to the mKdV hierarchy which appears in the analysis in terms of conventional orthogonal polynomials on the circle.

  4. Quaternion Formalism for the Intrinsic Transfer Matrix

    NASA Astrophysics Data System (ADS)

    Cretu, Nicolae; Pop, Mihail Ioan; Boer, Attila

    A quaternion formulation is applied to the intrinsic transfer matrix for longitudinal elastic wave propagation through a multilayer medium in order to find the spectral response of a sonic crystal. Resonance conditions and the band structure of the crystal are obtained. The presence of a defect is also analysed. The analysis is carried out theoretically and through simulations. A coupled oscillators model is used to validate the obtained results from a phenomenological point of view. Experimental measurements are carried out for some periodic multilayer arrangements and they are correlated with theory. The obtained spectral response and band structure are essential in characterising the sonic crystal and also in optimising its structure in order to obtain specific passbands and stopbands. The adaptedness of the quaternion formulation to periodic structures and to the inclusion of defects is considered.

  5. Investigations on 4x4 polymer couplers for airborne environment

    NASA Astrophysics Data System (ADS)

    Klotzbuecher, Thomas; Sprzagala, M.; Koch, Anne; Teubner, Ulrich

    2004-09-01

    Due to the potential of high data rates up to several Gb/s, low electromagnetic interference sensitivity and weight reduction capabilities, in future, optical data transmission will become standard in airplanes. The requirements on the necessary optical components that have to be operated in airborne environment in general are extremely high. In addition, airframe manufacturers are interested in low cost components. An example for such an optical component is a star coupler for data distribution, in particular, a device made on base of polymers. The applicability of such 4x4 polymer star couplers under extreme environmental conditions was investigated. The investigations were made at temperatures from -40 to +80 °C and up to 98 % humidity. Different types of housings were tested (polymer, metal, ceramic). It was found that housing of the polymer couplers is required necessarily, since non-housed components exhibit a large insertion loss increase of up to 0.5 dB during temperature variation. Best results were achieved with metal or ceramic housings exhibiting a maximum insertion loss increase of approximately 0.1 dB. However, due to a large difference of thermal expansion coefficients of filling and housing material, respectively, ceramic housings mechanically failed (crack formation) and thus metal housings are first choice. The results were also compared to those achieved for commercial 4x4 multimode couplers made of glass and based on fused bi-conical taper technology.

  6. Experimental test of the Chao matrix formalism for spin dynamics.

    NASA Astrophysics Data System (ADS)

    Morozov, V. S.; Chao, A. W.; Krisch, A. D.; Leonova, M. A.; Raymond, R. S.; Sivers, D. W.; Wong, V. K.; Gebel, R.; Lehrach, A.; Lorentz, B.; Maier, R.; Prasuhn, D.; Schnase, A.; Stockhorst, H.; Hinterberger, F.; Ulbrich, K.

    2007-04-01

    We recently started testing Chao's proposed new matrix formalism for describing the spin dynamics due to a single spin resonance in a stored polarized beam. This formalism seems to be the first generalization of the Froissart-Stora equation since it was published in 1960. It allows one to calculate analytically the polarization's behavior inside a resonance, which is not possible using the Froissart-Stora equation. We recently tested some Chao formalism predictions using a 1.85 GeV/c polarized deuteron beam stored in COSY. We swept an rf dipole's frequency through 200 Hz, at different sweep rates, while varying the distance from the sweep's end frequency to an rf-induced spin resonance's central frequency. We compared our experimental data with the predictions of the Chao formalism and the prediction of a phenomenological Froissart-Stora-based two-fluid model. The Froissart-Stora formula itself can make no prediction inside the resonance. The data seem to support the validity of the Chao formalism. (Supported by the German BMBF Science Ministry.)

  7. 4x4 and 8x8 optical cross connect for optical fiber networks

    NASA Astrophysics Data System (ADS)

    Zickar, Michael; Noell, Wilfried; Marxer, Cornel; de Rooij, Nicolaas F.

    2004-08-01

    We report on a 4x4 optical matrix switch for telecom application. It consists of a 4x4 array of vertical mirrors that have the same pitch as the fibers of commercially available fiber ribbons (250 μm). This compact design enables a parallel assembly to optical components, which simplifies the time consuming and costly process for switches with larger pitch. Additionally, a small pitch leads to a short optical coupling length, which facilitates the integration of a suitable collimation system. However there are physical limitations for optical MEMS in conjunction with assembled micro-optics. The optical beam exiting a collimator diverges, the divergence angle is indirectly proportional to the beam waist and the coupling length increases quadratically. Our calculations show that for a pitch of 250 μm a mirror height of 100 μm is optimal. The mirrors are monolithically etched onto a platform etched during a previous step. No assembly of the mirrors to the actuators is needed. Alignment structures for the optical components are etched during the same step as the mirrors, which lead to self aligned structures. The platform is supported by 150 μm long torsion beams with sub-micron diameter. The electrostatic actuation voltage is given by a separate chip. The mirror moves out of the optical path when the platform is actuated and goes to the switching state if no voltage is applied. The first prototypes have been actuated at 200 V, which agrees with a CoventorWare simulation used for designing the device. Light was successfully switched with a 4x4 OXC. An 8x8 OXC is shown and electrostatically characterized.

  8. 4x4 Individually Addressable InGaAs APD Arrays Optimized for Photon Counting Applications

    NASA Technical Reports Server (NTRS)

    Gu, Y.; Wu, X.; Wu, S.; Choa, F. S.; Yan, F.; Shu, P.; Krainak, M.

    2007-01-01

    InGaAs APDs with improved photon counting characteristics were designed and fabricated and their performance improvements were observed. Following the results, a 4x4 individually addressable APD array was designed, fabricated, and results are reported.

  9. Window type: 4x4 multipaned steel window flanked by 1x4 multipaned ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Window type: 4x4 multipaned steel window flanked by 1x4 multipaned steel, casements. Concrete stoop, entry overhang and pipe rail detail also illustrated. Building 36, facing northwest - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  10. The Feasibility of 4X4 Block Scheduling in Secondary Schools: A Review of the Literature.

    ERIC Educational Resources Information Center

    Stanley, Anthony; Gifford, Lorna J.

    This paper reviews the literature on 4x4 block scheduling. Studies reveal that the advantages of such scheduling are simplicity, potential for greater student achievement, and reduced disciplinary referrals. Discipline is enhanced through this type of schedule because it decreases the number of times that students are moving in the halls between…

  11. Transfer-matrix approach to three-dimensional bond percolation: An application of Novotny's formalism

    NASA Astrophysics Data System (ADS)

    Nishiyama, Yoshihiro

    2006-01-01

    A transfer-matrix simulation scheme for the three-dimensional (d=3) bond percolation is presented. Our scheme is based on Novotny’s transfer-matrix formalism, which enables us to consider arbitrary (integral) number of sites N constituting a unit of the transfer-matrix slice even for d=3 . Such an arbitrariness allows us to perform systematic finite-size-scaling analysis of the criticality at the percolation threshold. Diagonalizing the transfer matrix for N=4,5,…,10 , we obtain an estimate for the correlation-length critical exponent ν=0.81(5) .

  12. Transfer-matrix approach to three-dimensional bond percolation: an application of Novotny's formalism.

    PubMed

    Nishiyama, Yoshihiro

    2006-01-01

    A transfer-matrix simulation scheme for the three-dimensional (d=3) bond percolation is presented. Our scheme is based on Novotny's transfer-matrix formalism, which enables us to consider arbitrary (integral) number of sites N constituting a unit of the transfer-matrix slice even for d=3. Such an arbitrariness allows us to perform systematic finite-size-scaling analysis of the criticality at the percolation threshold. Diagonalizing the transfer matrix for N=4, 5,..., we obtain an estimate for the correlation-length critical exponent v=0.81(5). PMID:16486223

  13. Science teachers' understanding and use of instructional strategies within the 4 x 4 block schedule

    NASA Astrophysics Data System (ADS)

    Grosshans, Kurt

    The primary purpose of this researcher was to investigate how science teachers engage students under the 4 x 4 block schedule and how the teachers' understanding of how they use instructional strategies influenced their lessons. As an inquiry-based approach has been adopted by the National Science Standards, research has suggested that block scheduling provides more time for teachers to incorporate varied strategies such as inquiry-based and cooperative learning teaching which have philosophical roots in a social constructivist philosophy. This research investigated the questions: What instructional strategies do science teachers use to engage students on the 4 x 4 block schedule? How do science teachers understand their use of instructional strategies? The methodology was qualitative in nature and involved a multiple case study of three high school science teachers at a large rural county high school. Data sources included pre-observation interviews, classroom observations, post-observation interviews, and the collection of documents and artifacts such as lesson plans, student hand-outs, worksheets, laboratory exercises, homework and other document(s) the teacher used to prepare for or implement a lesson. The evidence observed in this study, suggests that the strategies used by these three science teachers remain mostly didactic in nature. Although the teachers reported in the interview phase of this research that they use a wide variety of strategies, what was observed within the 4 x 4 block structure was the use of different didactic strategies, not different holistic strategies. Although the teachers were aware of more holistic strategies such as inquiry-based and cooperative learning, they were not adopted nor adapted within the lesson. The three teachers used strategies that were consistent with their scientific realist views concerning the nature of science. These scientific realist philosophies are antithetical to a social constructivist approach to

  14. Optical 4x4 hitless slicon router for optical networks-on-chip (NoC).

    PubMed

    Sherwood-Droz, Nicolás; Wang, Howard; Chen, Long; Lee, Benjamin G; Biberman, Aleksandr; Bergman, Keren; Lipson, Michal

    2008-09-29

    We demonstrate here a spatially non-blocking optical 4x4 router with a footprint of 0.07 mm(2) for use in future integrated photonic interconnection networks. The device is dynamically switched using thermo-optically tuned silicon microring resonators with a wavelength shift to power ratio of 0.25nm/mW. The design can route four optical inputs to four outputs with individual bandwidths of up to 38.5 GHz. All tested configurations successfully routed a single-wavelength laser and provided a maximum extinction ratio larger than 20 dB. PMID:18825228

  15. Extraction of linear anisotropic parameters using optical coherence tomography and hybrid Mueller matrix formalism.

    PubMed

    Liao, Chia-Chi; Lo, Yu-Lung

    2015-04-20

    A method is proposed for extracting the linear birefringence (LB) and linear dichroism (LD) properties of an anisotropic optical sample using reflection-mode optical coherence tomography (OCT) and a hybrid Mueller matrix formalism. To ensure the accuracy of the extracted parameter values, a method is proposed for calibrating and compensating the polarization distortion effect induced by the beam splitters in the OCT system using a composite quarter-waveplate / half-waveplate / quarter-waveplate structure. The validity of the proposed method is confirmed by extracting the LB and LD properties of a quarter-wave plate and a defective polarizer. To the best of the authors' knowledge, the method proposed in this study represents the first reported attempt to utilize an inverse Mueller matrix formalism and a reflection-mode OCT structure to extract the LB and LD parameters of optically anisotropic samples. PMID:25969104

  16. Quad fourfold (4 X 4) logic unit (LBL No. 21X6421 P-1)

    SciTech Connect

    Mcdonald R.J.; Landis, D.A.; Maier, R.M.; Rude, B.S.; Wozniak, G.J.

    1987-01-01

    A quad fourfold (4 x 4) logic unit has been designed and packaged in a single-width NIM module for use in nuclear and atomic physics experiments. The four inputs of each unit are combined internally to perform logical AND, OR, and VETO functions. A set of eight DIP switches on the front panel select either the input signal or its complement, trigger slope, output pulse duration, and positive or negative logic on the overlap signal. A one-shot multivibrator may be triggered on either the positive or negative-going slope of the overlap signal to form the shaped output. The output width can be adjusted between approx.50 ns and 50 ..mu..sec with two coarse ranges and a twenty-turn potentiometer. An LED attached to the one-shot gives a visual indication of the output rate. 4 figs.

  17. Optical simulation of photovoltaic modules with multiple textured interfaces using the matrix-based formalism OPTOS.

    PubMed

    Tucher, Nico; Eisenlohr, Johannes; Gebrewold, Habtamu; Kiefel, Peter; Höhn, Oliver; Hauser, Hubert; Goldschmidt, Jan Christoph; Bläsi, Benedikt

    2016-07-11

    The OPTOS formalism is a matrix-based approach to determine the optical properties of textured optical sheets. It is extended within this work to enable the modelling of systems with an arbitrary number of textured, plane-parallel interfaces. A matrix-based system description is derived that accounts for the optical reflection and transmission interaction between all textured interfaces. Using OPTOS, we calculate reflectance and absorptance of complete photovoltaic module stacks, which consist of encapsulated silicon solar cells featuring textures that operate in different optical regimes. As exemplary systems, solar cells with and without module encapsulation are shown to exhibit a considerable absorptance gain if the random pyramid front side texture is combined with a diffractive rear side grating. A variation of the sunlight's angle of incidence reveals that the grating gain is almost not affected for incoming polar angles up to 60°. Considering as well the good agreement with alternative simulation techniques, OPTOS is demonstrated to be a versatile and efficient method for the optical analysis of photovoltaic modules. PMID:27410896

  18. Utilization of Mueller matrix formalism to obtain optical targets depolarization and polarization properties

    NASA Astrophysics Data System (ADS)

    Le Roy-Brehonnet, F.; Le Jeune, B.

    Polarization is an important property of several physical phenomena such as Rayleigh and Raman ( High intensity Raman Interactions: A. Penzkofer, A. Lauberteau, and W. Kaiser, Progress in Quantum Electronics, 6) (1982) scattering ( Multi-photon Scattering Molecular Spectroscopy, S. Kielich, Progress in Optics, E. Wolf(ed.) North-Holland, Amsterdam) (1983) or fluorescence ( Principles of Fluorescence Spectroscopy, J.R. Lakowicz, Plenum Press) (1986) for example, but also for laser spectral lines ( Laser Lines in Atomic Species, C. S. Willett, Progress in Quantum Electronics, 1) (1969). So, the polarimetric aspect for the propagation in media, such as fibres (Recent progress in fibre optics, G. Cancellieri, F. Chiaraluce, Progress in Quantum Electronics, 18) (1994), the atmosphere and the sea ( Light Scattering by Small Particles (Dover, New York, 1981), must be considered. Following general considerations on the different polarimetric formalisms(Chapter I), this paper first presents a review of present theoretical works on the exploitation of the Mueller matrix (Chapter II). This is followed by original studies of our own, concerning the possibility of extracting polarizing and depolarizing properties of a target characterized by a Mueller matrix (Chapter III). We then study the depolarization effects induced by targets in the Poincare´space (Chapter IV). This depolarization is induced by multiple reflections on rough surfaces or due to partial volume scattering. We have developed an algorithm, based on the knowledge of experimental noise, to classify experimental Mueller matrices according to their polarimetric characteristics. The laser imaging set-up used is described and the method (such as dichroic and birefringent ferrofluid samples) and surfaces (such as sand and other natural targets, dielectric or metallic rough targets).

  19. A Jones matrix formalism for simulating three-dimensional polarized light imaging of brain tissue.

    PubMed

    Menzel, M; Michielsen, K; De Raedt, H; Reckfort, J; Amunts, K; Axer, M

    2015-10-01

    The neuroimaging technique three-dimensional polarized light imaging (3D-PLI) provides a high-resolution reconstruction of nerve fibres in human post-mortem brains. The orientations of the fibres are derived from birefringence measurements of histological brain sections assuming that the nerve fibres—consisting of an axon and a surrounding myelin sheath—are uniaxial birefringent and that the measured optic axis is oriented in the direction of the nerve fibres (macroscopic model). Although experimental studies support this assumption, the molecular structure of the myelin sheath suggests that the birefringence of a nerve fibre can be described more precisely by multiple optic axes oriented radially around the fibre axis (microscopic model). In this paper, we compare the use of the macroscopic and the microscopic model for simulating 3D-PLI by means of the Jones matrix formalism. The simulations show that the macroscopic model ensures a reliable estimation of the fibre orientations as long as the polarimeter does not resolve structures smaller than the diameter of single fibres. In the case of fibre bundles, polarimeters with even higher resolutions can be used without losing reliability. When taking the myelin density into account, the derived fibre orientations are considerably improved. PMID:26446561

  20. Matrix formalism for light propagation and absorption in thick textured optical sheets.

    PubMed

    Eisenlohr, Johannes; Tucher, Nico; Höhn, Oliver; Hauser, Hubert; Peters, Marius; Kiefel, Peter; Goldschmidt, Jan Christoph; Bläsi, Benedikt

    2015-06-01

    In this paper, we introduce a simulation formalism for determining the Optical Properties of Textured Optical Sheets (OPTOS). Our matrix-based method allows for the computationally-efficient calculation of non-coherent light propagation and absorption in thick textured sheets, especially solar cells, featuring different textures on front and rear side that may operate in different optical regimes. Within the simulated system, the angular power distribution is represented by a vector. This light distribution is modified by interaction with the surfaces of the textured sheets, which are described by redistribution matrices. These matrices can be calculated for each individual surface texture with the most appropriate technique. Depending on the feature size of the texture, for example, either ray- or wave-optical methods can be used. The comparison of the simulated absorption in a sheet of silicon for a variety of surface textures, both with the results from other simulation techniques and experimentally measured data, shows very good agreement. To demonstrate the versatility of this newly-developed approach, the absorption in silicon sheets with a large-scale structure (V-grooves) at the front side and a small-scale structure (diffraction grating) at the rear side is calculated. Moreover, with minimal computational effort, a thickness parameter variation is performed. PMID:26072875

  1. Theoretical formulation of Doppler redistribution in scattering polarization within the framework of the velocity-space density matrix formalism

    NASA Astrophysics Data System (ADS)

    Belluzzi, L.; Landi Degl'Innocenti, E.; Trujillo Bueno, J.

    2013-04-01

    Within the framework of the density matrix theory for the generation and transfer of polarized radiation, velocity density matrix correlations represent an important physical aspect that, however, is often neglected in practical applications when adopting the simplifying approximation of complete redistribution on velocity. In this paper, we present an application of the non-LTE problem for polarized radiation taking such correlations into account through the velocity-space density matrix formalism. We consider a two-level atom with infinitely sharp upper and lower levels, and we derive the corresponding statistical equilibrium equations, neglecting the contribution of velocity-changing collisions. Coupling such equations with the radiative transfer equations for polarized radiation, we derive a set of coupled equations for the velocity-dependent source function. This set of equations is then particularized to the case of a plane-parallel atmosphere. The equations presented in this paper provide a complete and solid description of the physics of pure Doppler redistribution, a phenomenon generally described within the framework of the redistribution matrix formalism. The redistribution matrix corresponding to this problem (generally referred to as RI) is derived starting from the statistical equilibrium equations for the velocity-space density matrix and from the radiative transfer equations for polarized radiation, thus showing the equivalence of the two approaches.

  2. Auxiliary matrix formalism for interaction representation transformations, optimal control, and spin relaxation theories

    SciTech Connect

    Goodwin, D. L.; Kuprov, Ilya

    2015-08-28

    Auxiliary matrix exponential method is used to derive simple and numerically efficient general expressions for the following, historically rather cumbersome, and hard to compute, theoretical methods: (1) average Hamiltonian theory following interaction representation transformations; (2) Bloch-Redfield-Wangsness theory of nuclear and electron relaxation; (3) gradient ascent pulse engineering version of quantum optimal control theory. In the context of spin dynamics, the auxiliary matrix exponential method is more efficient than methods based on matrix factorizations and also exhibits more favourable complexity scaling with the dimension of the Hamiltonian matrix.

  3. The physical meaning of scattering matrix singularities in coupled-channel formalisms

    SciTech Connect

    S. Capstick; A. Svarc; L. Tiator; J. Gegelia; M.M. Giannini; E. Santopinto; C. Hanhart; S. Scherer; T.-S.H. Lee; T. Sato; N. Suzuki

    2007-09-04

    The physical meaning of bare and dressed scattering matrix singularities has been investigated. Special attention has been attributed to the role of well known invariance of scattering matrix with respect to the field transformation of the effective Lagrangian. Examples of evaluating bare and dressed quantities in various models are given.

  4. Weak Topological Insulators and Composite Weyl Semimetals: β-Bi_{4}X_{4} (X=Br, I).

    PubMed

    Liu, Cheng-Cheng; Zhou, Jin-Jian; Yao, Yugui; Zhang, Fan

    2016-02-12

    While strong topological insulators (STIs) were experimentally realized soon after they were theoretically predicted, a weak topological insulator (WTI) has yet to be unambiguously confirmed. A major obstacle is the lack of distinct natural cleavage surfaces to test the surface selective hallmark of a WTI. With a new scheme, we discover that β-Bi_{4}X_{4} (X=Br, I), dynamically stable or synthesized before, can be a prototype WTI with two natural cleavage surfaces, where two anisotropic Dirac cones stabilize and annihilate, respectively. We further find four surface-state Lifshitz transitions under charge doping and two bulk topological phase transitions under uniaxial strain. Near the WTI-STI transition, there emerges a novel Weyl semimetal phase, in which the Fermi arcs generically appear at both cleavage surfaces whereas the Fermi circle only appears at one selected surface. PMID:26919004

  5. Energy density matrix formalism for interacting quantum systems: a quantum Monte Carlo study

    SciTech Connect

    Krogel, Jaron T; Kim, Jeongnim; Reboredo, Fernando A

    2014-01-01

    We develop an energy density matrix that parallels the one-body reduced density matrix (1RDM) for many-body quantum systems. Just as the density matrix gives access to the number density and occupation numbers, the energy density matrix yields the energy density and orbital occupation energies. The eigenvectors of the matrix provide a natural orbital partitioning of the energy density while the eigenvalues comprise a single particle energy spectrum obeying a total energy sum rule. For mean-field systems the energy density matrix recovers the exact spectrum. When correlation becomes important, the occupation energies resemble quasiparticle energies in some respects. We explore the occupation energy spectrum for the finite 3D homogeneous electron gas in the metallic regime and an isolated oxygen atom with ground state quantum Monte Carlo techniques imple- mented in the QMCPACK simulation code. The occupation energy spectrum for the homogeneous electron gas can be described by an effective mass below the Fermi level. Above the Fermi level evanescent behavior in the occupation energies is observed in similar fashion to the occupation numbers of the 1RDM. A direct comparison with total energy differences demonstrates a quantita- tive connection between the occupation energies and electron addition and removal energies for the electron gas. For the oxygen atom, the association between the ground state occupation energies and particle addition and removal energies becomes only qualitative. The energy density matrix provides a new avenue for describing energetics with quantum Monte Carlo methods which have traditionally been limited to total energies.

  6. Simulation of coherence selection by pulsed field gradients in liquid-state NMR using an auxiliary matrix formalism

    NASA Astrophysics Data System (ADS)

    Edwards, Luke J.

    2014-03-01

    An algorithm for simulating coherence selection due to a pulse sequence element consisting of two pulsed field gradients separated by a short collection of pulses and delays is introduced. This algorithm involves computation of the matrix exponential of an auxiliary matrix twice the size of the system Liouvillian, a dimensional increase smaller than is required with other known computational methods. Approximations valid for most simulations of liquid-state NMR spectra are involved in the derivation. Diffusion is omitted, but could be treated in an approximate way as a damping over the pulse sequence element. Several NMR pulse sequences using gradients for coherence selection have been implemented, making use of the functionality of Spinach (http://spindynamics.org/Spinach.php). Example simulations testing these implementations are presented, and the extent to which the formal dimensional reduction can lead to a speedup in simulation time discussed. It is found that the previously known methods can be made competitive with the auxiliary matrix method by making use of their embarrassingly parallel nature. Cases where the relative dimensional reduction of the auxiliary matrix method is very large, or where efficient parallelization of the simulation independent of the nature of the algorithm used exists, are found to lead to situations beneficial for the auxiliary matrix algorithm in this comparison.

  7. Statistical model of dephasing in mesoscopic devices introduced in the scattering matrix formalism

    NASA Astrophysics Data System (ADS)

    Pala, Marco G.; Iannaccone, Giuseppe

    2004-06-01

    We propose a phenomenological model of dephasing in mesoscopic transport, based on the introduction of random-phase fluctuations in the computation of the scattering matrix of the system. A Monte Carlo averaging procedure allows us to extract electrical and microscopic device properties. We show that, in this picture, scattering matrix properties enforced by current conservation and time-reversal invariance still hold. In order to assess the validity of the proposed approach, we present simulations of conductance and magnetoconductance of Aharonov-Bohm rings that reproduce the behavior observed in experiments, in particular as far as aspects related to decoherence are concerned.

  8. General formalism for partial spatial coherence in reflection Mueller matrix polarimetry.

    PubMed

    Ossikovski, Razvigor; Hingerl, Kurt

    2016-09-01

    Starting from the first principles, we derive the expressions governing partially coherent Mueller matrix reflection polarimetry on spatially inhomogeneous samples. These are reported both in their general form and in the practically important specific form for two juxtaposed media. PMID:27607968

  9. Vertical comb-drive microscanner with 4x4 array of micromirrors for phase-shifting Mirau microinterferometry

    NASA Astrophysics Data System (ADS)

    Bargiel, Sylwester; Lullin, Justine; Lemoal, Patrice; Perrin, Stéphane; Passilly, Nicolas; Albero, Jorge; Froehly, Luc; Lardet-Vieudrin, Franck; Gorecki, Christophe

    2016-04-01

    In this paper, we present construction, fabrication and characterization of an electrostatic MOEMS vertical microscanner for generation of an optical phase shift in array-type interferometric microsystems. The microscanner employs asymmetric comb-drives for a vertical displacement of a large 4x4 array of reference micromirrors and for in-situ position sensing. The device is designed to be fully compatible with Mirau configuration and with vertical integration strategy. This enables further integration of the device within an "active" multi-channel Mirau micro-interferometer and implementation of the phase shifting interferometry (PSI) technique for imaging applications. The combination of micro-interferometer and PSI is particularly interesting in the swept-source optical coherence tomography, since it allows not only strong size reduction of a system but also improvement of its performance (sensitivity, removal of the image artefacts). The technology of device is based on double-side DRIE of SOI wafer and vapor HF releasing of the suspended platform. In the static mode, the device provides vertical displacement of micromirrors up to 2.8μm (0 - 40V), whereas at resonance (fo=500 Hz), it reaches 0.7 μm for only 1VDC+1VAC. In both operation modes, the measured displacement is much more than required for PSI implementation (352nm peak-to-peak). The presented device is a key component of array-type Mirau micro-interferometer that enables the construction of portable, low-cost interferometric systems, e.g. for in vivo medical diagnostics.

  10. An Existence Proof: Successful Joint Implementation of the IMP Curriculum and a 4 x 4 Block Schedule at a Suburban U.S. High School

    ERIC Educational Resources Information Center

    Kramer, Steven L.; Keller, Regina

    2008-01-01

    This "Brief Report" summarizes results from a study that investigated joint effects of two innovations adopted at a high school in an affluent suburban community in the northeast United States: 4 x 4 block scheduling and the "Standards"-based curriculum, the Interactive Mathematics Program (IMP).

  11. Ginzburg-Landau Free Energy of Crystalline Color Superconductors: A Matrix Formalism from Solid-State Physics

    NASA Astrophysics Data System (ADS)

    Cao, Gao-Qing; He, Lian-Yi

    2015-12-01

    The Ginzburg-Landau (GL) free energy of crystalline color superconductors is important for understanding the nature of the phase transition to the normal quark matter and predicting the preferred crystal structure. So far the GL free energy at zero temperature has only been evaluated up to the sixth order in the condensate. To give quantitative reliable predictions we need to evaluate the higher-order terms. In this work, we present a new derivation of the GL free energy by using the discrete Bloch representation of the fermion field. This derivation introduces a simple matrix formalism without any momentum constraint, which may enable us to calculate the GL free energy to arbitrary order by using a computer. Supported by the National Natural Science Foundation of China under Grant No. 11335005 and the Ministry of Science and Technology under Grant Nos. 2013CB922000 and 2014CB845400, and by the US Department of Energy Topical Collaboration “Neutrinos and Nucleosynthesis in Hot and Dense Matter”

  12. 70 kHz full 4x4 Mueller polarimeter and simultaneous fiber calibration for endoscopic applications.

    PubMed

    Rivet, Sylvain; Bradu, Adrian; Podoleanu, Adrian

    2015-09-01

    A new set-up is proposed to measure the full polarimetric properties of a sample through an optical fiber, paving the way to full-Mueller endoscopic imaging. The technique combines a channeled spectrum polarimeter and an interferometer. This permits high-speed measurement of two Mueller matrices simultaneously. The first matrix characterizes only the fiber while the second characterizes both fiber and sample. The instrument is validated on vacuum, a quarter-wave plate and a linear polarizer for single-point measurements. Insensitivity of the polarimetric measurement to fiber disturbances is proven while manipulating the fiber. PMID:26368471

  13. Matrix formalism of electromagnetic wave propagation through multiple layers in the near-field region: application to the flat panel display.

    PubMed

    Lee, C Y; Lee, D E; Hong, Y K; Shim, J H; Jeong, C K; Joo, J; Zang, D S; Shim, M G; Lee, J J; Cha, J K; Yang, H G

    2003-04-01

    We have developed an electromagnetic (EM) wave propagation theory through a single layer and multiple layers in the near-field and far-field regions, and have constructed a matrix formalism in terms of the boundary conditions of the EM waves. From the shielding efficiency (SE) against EM radiation in the near-field region calculated by using the matrix formalism, we propose that the effect of multiple layers yields enhanced shielding capability compared to a single layer with the same total thickness in conducting layers as the multiple layers. We compare the intensities of an EM wave propagating through glass coated with conducting indium tin oxide (ITO) on one side and on both sides, applying it to the electromagnetic interference (EMI) shielding filter in a flat panel display such as a plasma display panel (PDP). From the measured intensities of EMI noise generated by a PDP loaded with ITO coated glass samples, the two-side coated glass shows a lower intensity of EMI noise compared to the one-side coated glass. The result confirms the enhancement of the SE due to the effect of multiple layers, as expected in the matrix formalism of EM wave propagation in the near-field region. In the far-field region, the two-side coated glass with ITO in multiple layers has a higher SE than the one-side coated glass with ITO, when the total thickness of ITO in both cases is the same. PMID:12786507

  14. General formalism for the efficient calculation of the Hessian matrix of EM data misfit and Hessian-vector products based upon adjoint sources approach

    NASA Astrophysics Data System (ADS)

    Pankratov, Oleg; Kuvshinov, Alexey

    2015-03-01

    3-D electromagnetic (EM) studies of the Earth have advanced significantly over the past decade. Despite a certain success of the 3-D EM inversions of real data sets, the quantitative assessment of the recovered models is still a challenging problem. It is known that one can gain valuable information about model uncertainties from the analysis of Hessian matrix. However, even with modern computational capabilities the calculation of the Hessian matrix based on numerical differentiation is extremely time consuming. Much more efficient way to compute the Hessian matrix is provided by an `adjoint sources' methodology. The computation of Hessian matrix (and Hessian-vector products) using adjoint formulation is now well-established approach, especially in seismic inverse modelling. As for EM inverse modelling we did not find in the literature a description of the approach, which would allow EM researchers to apply this methodology in a straightforward manner to their scenario of interest. In the paper, we present formalism for the efficient calculation of the Hessian matrix using adjoint sources approach. We also show how this technique can be implemented to calculate multiple Hessian-vector products very efficiently. The formalism is general in the sense that it allows to work with responses that arise in EM problem set-ups either with natural- or controlled-source excitations. The formalism allows for various types of parametrization of the 3-D conductivity distribution. Using this methodology one can readily obtain appropriate formulae for the specific sounding methods. To illustrate the concept we provide such formulae for two EM techniques: magnetotellurics and controlled-source sounding with vertical magnetic dipole as a source.

  15. General transfer matrix formalism to calculate DNA–protein–drug binding in gene regulation: application to OR operator of phage λ

    PubMed Central

    Teif, Vladimir B.

    2007-01-01

    The transfer matrix methodology is proposed as a systematic tool for the statistical–mechanical description of DNA–protein–drug binding involved in gene regulation. We show that a genetic system of several cis-regulatory modules is calculable using this method, considering explicitly the site-overlapping, competitive, cooperative binding of regulatory proteins, their multilayer assembly and DNA looping. In the methodological section, the matrix models are solved for the basic types of short- and long-range interactions between DNA-bound proteins, drugs and nucleosomes. We apply the matrix method to gene regulation at the OR operator of phage λ. The transfer matrix formalism allowed the description of the λ-switch at a single-nucleotide resolution, taking into account the effects of a range of inter-protein distances. Our calculations confirm previously established roles of the contact CI–Cro–RNAP interactions. Concerning long-range interactions, we show that while the DNA loop between the OR and OL operators is important at the lysogenic CI concentrations, the interference between the adjacent promoters PR and PRM becomes more important at small CI concentrations. A large change in the expression pattern may arise in this regime due to anticooperative interactions between DNA-bound RNA polymerases. The applicability of the matrix method to more complex systems is discussed. PMID:17526526

  16. Transfer-matrix Formalism for the Calculation of Optical Response in Multilayer Systems: from Coherent to Incoherent Interference

    SciTech Connect

    Troparevski, Claudia; Sabau, Adrian S; Lupini, Andrew R; Zhang, Zhenyu

    2010-01-01

    We present a novel way to account for partially coherent and incoherent interference phenomena in optical multilayer systems via the transfer-matrix method. The transfer matrix method is employed in its usual way via Fresnel coefficients in a 2x2 matrix configuration. The novel feature is that there is no need to use modified Fresnel coefficients or the square of their amplitudes to work in the incoherent limit. The transition from coherent, to partially coherent, to incoherent interference is achieved by introducing a random phase of increasing intensity in the propagating media. This random phase can simulate the effect of defects or impurities in the media. This method provides a general way of dealing with optical multilayer systems, in which coherent and incoherent interference are treated on equal footing.

  17. Interaction of a Guided Wave with a Crack in an Embedded Multilayered Anisotropic Plate: Global Matrix with Laplace Transform Formalism

    NASA Astrophysics Data System (ADS)

    Mora, Pierric; Ducasse, Eric; Deschamps, Marc

    We solve the problem of the interaction of a transient guided elastic wave by a planar crack with an indirect Boundary Element approach in the Laplace domain (t → s). The originality of this work is to use the numerical Green function of the layered plate rather than the analytical Green function of each layer. As a consequence, the BEM matrices are small. To obtain the Green function in the (x,z,s) domain we first solve the equations in the Fourier transform (k,z,s) domain with a Global Matrix approach, and then perform a numerical inverse FFT. Comparisons with finite element show excellent agreement. This approach is fast and low memory consuming for planar defects in arbitrary layered media, and can be extended to arbitrary shapes and boundary conditions for a higher computational cost. It is valid in 3D, however only the 2D case is considered in this work.

  18. Extended ABCD matrix formalism for the description of femtosecond diffraction patterns; application to femtosecond digital in-line holography with anamorphic optical systems.

    PubMed

    Brunel, Marc; Shen, Huanhuan; Coetmellec, Sebastien; Lebrun, Denis

    2012-03-10

    We present a new model to predict diffraction patterns of femtosecond pulses through complex optical systems. The model is based on the extension of an ABCD matrix formalism combined with generalized Huygens-Fresnel transforms (already used in the CW regime) to the femtosecond regime. The model is tested to describe femtosecond digital in-line holography experiments realized in situ through a cylindrical Plexiglas pipe. The model allows us to establish analytical relations that link the holographic reconstruction process to the experimental parameters of the pipe and of the incident beam itself. Simulations and experimental results are in good concordance. Femtosecond digital in-line holography is shown to allow significant coherent noise reduction, and this model will be particularly efficient to describe a wide range of optical geometries. More generally, the model developed can be easily used in any experiment where the knowledge of the precise evolution of femtosecond transverse patterns is required. PMID:22410994

  19. Evaluation of light extraction efficiency for the light-emitting diodes based on the transfer matrix formalism and ray-tracing method

    NASA Astrophysics Data System (ADS)

    Pingbo, An; Li, Wang; Hongxi, Lu; Zhiguo, Yu; Lei, Liu; Xin, Xi; Lixia, Zhao; Junxi, Wang; Jinmin, Li

    2016-06-01

    The internal quantum efficiency (IQE) of the light-emitting diodes can be calculated by the ratio of the external quantum efficiency (EQE) and the light extraction efficiency (LEE). The EQE can be measured experimentally, but the LEE is difficult to calculate due to the complicated LED structures. In this work, a model was established to calculate the LEE by combining the transfer matrix formalism and an in-plane ray tracing method. With the calculated LEE, the IQE was determined and made a good agreement with that obtained by the ABC model and temperature-dependent photoluminescence method. The proposed method makes the determination of the IQE more practical and conventional. Project supported by the National Natural Science Foundation of China (Nos.11574306, 61334009), the China International Science and Technology Cooperation Program (No. 2014DFG62280), and the National High Technology Program of China (No. 2015AA03A101).

  20. Reanalysis of the ground and three torsional excited states of trans-ethyl methyl ether by using an IAM-like tunneling matrix formalism

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kaori; Sakai, Yusuke; Tsunekawa, Shozo; Miyamoto, Taihei; Fujitake, Masaharu; Ohashi, Nobukimi

    2016-03-01

    The trans-ethyl methyl ether has two inequivalent methyl internal rotors and shows tunneling splittings of maximum up to five components. However, the barrier of these two internal rotation potentials were relatively high and the five components were not resolved in the ground state microwave spectra. In this study, well-resolved Fourier transform microwave ground state spectrum was measured for the first time to resolve the five components. The ground state microwave spectra were reanalyzed based on these new measurements and the additional millimeter-wave spectra as well as those studied previously by Fuchs et al. Ninety Fourier transform microwave spectral lines were assigned to 107 transitions in the ground state and 3508 conventional microwave absorption lines were assigned up to Ka = 16 of the ground state, including all 707 lines reported by Fuchs et al. In addition, 10 transitions were observed by the double resonance experiment. They were least-squares-analyzed by the use of an internal axis method (IAM)-like tunneling matrix formalism based on an extended permutation-inversion group theoretical idea. Twenty-two molecular parameters composed of rotational constants, centrifugal distortion constants, internal rotation parameters and internal rotation tunneling parameters were determined for the ground state. The microwave spectra in the three torsionally excited states, that is, the ν28 = 1 C-CH3 torsional state, the ν29 = 1 O-CH3 torsional state and the ν30 = 1 skeletal torsional state, were also reanalyzed by using the IAM-like tunneling matrix formalism and somewhat extended line assignments.

  1. Evaluation of the implementation of the R-matrix formalism with reference to the astrophysically important 18F(p,α)15O reaction

    NASA Astrophysics Data System (ADS)

    Mountford, D. J.; deBoer, R. J.; Descouvemont, P.; Murphy, A. St. J.; Uberseder, E.; Wiescher, M.

    2014-12-01

    Background. The R-Matrix formalism is a crucial tool in the study of nuclear astrophysics reactions, and many codes have been written to implement the relevant mathematics. One such code makes use of Visual Basic macros. A further open-source code, AZURE, written in the FORTRAN programming language is available from the JINA collaboration and a C++ version, AZURE2, has recently become available. Purpose The detailed mathematics and extensive programming required to implement broadly applicable R-Matrix codes make comparisons between different codes highly desirable in order to check for errors. This paper presents a comparison of the three codes based around data and recent results of the astrophysically important 18F(p,α)15O reaction. Methods Using the same analysis techniques as in the work of Mountford et al. parameters are extracted from the two JINA codes, and the resulting cross-sections are compared. This includes both refitting data with each code and making low-energy extrapolations. Results All extracted parameters are shown to be broadly consistent between the three codes and the resulting calculations are in good agreement barring a known low-energy problem in the original AZURE code. Conclusion The three codes are shown to be broadly consistent with each other and equally valid in the study of astrophysical reactions, although one must be careful when considering low lying, narrow resonances which can be problematic when integrating.

  2. Modeling of the whispering gallery mode in microdisk and microgear resonators using a Toeplitz matrix formalism for single-photon source

    NASA Astrophysics Data System (ADS)

    Attia, Moez; Gueddana, Amor; Chatta, Rihab; Morand, Alain

    2013-09-01

    The work presented in this paper develops a new formalism to design microdisks and microgears structures. The main objective is to study the optics and geometrics parameters influence on the microdisks and microgears structures resonance behavior. This study is conducted to choice a resonance structure with height quality factor Q to be associated with Quantum dot to form a single photon source. This new method aims to design resonant structures that are simpler and requires less computing performances than FDTD and Floquet Block methods. This formalism is based on simplifying Fourier transformed and using toeplitz matrix writing. This new writing allows designing all kind of resonance structures with any defect and any modification. In other study we have design a quantum dot emitting a photon at 1550 nm of the fundamental mode, but the quantum dot emits other photons at other wavelengths. The focus of the resonant structure and the quantum dot association is the resonance of the photon at 1550 nm and the elimination of all other photons with others energies. The quantum dot studied in [1] is an InAs/GaAs quantum dot, we design an GaAS microdisk and microgear and we compare the quality factor Q of this two structures and we conclude that the microgear is more appropriated to be associate to the quantum dot and increase the probability P1 to obtain a single photon source at 1550 nm and promotes the obtaining of single photon. The performance improving of the resonant structure is able to increase the success of quantum applications such as quantum gates based on single photon source.

  3. Rethinking Formalisms in Formal Education

    ERIC Educational Resources Information Center

    Nathan, Mitchell J.

    2012-01-01

    I explore a belief about learning and teaching that is commonly held in education and society at large that nonetheless is deeply flawed. The belief asserts that mastery of "formalisms"--specialized representations such as symbolic equations and diagrams with no inherent meaning except that which is established by convention--is prerequisite to…

  4. Research on tunable phase shift induced by piezoelectric transducer in linearly chirped fiber Bragg grating with the V-I transmission matrix formalism

    NASA Astrophysics Data System (ADS)

    Wu, Liangying; Pei, Li; Liu, Chao; Wang, Jianshuai

    2016-05-01

    In this study, the V-I transmission matrix (V-I TM) is proposed to analyze the tunable single phase shift (SPS) and multiple phase shifts (MPS) inserted in a linearly chirped fiber Bragg grating (LCFBG). According to the simulation results, the peaks appear on the transmission spectrum, when the phase shifts are induced in the LCFBG. With the increase of the phase shift, the center wavelength of the peak moves toward long wavelength region. A remarkable degree of bilateral symmetry can be found as characteristic of the depth of peaks. The maximum depth caused by inserted π-shift is the symmetric axis. Moreover, when MPS are inserted simultaneously, the appeared peaks are independent and the variation tendency of each peak is the same with that caused by SPS. The experiment of phase shift induced by a piezoelectric transducer (PZT) verifies the correctness of the simulation, and a narrow bandwidth of 0.028 nm is acquired.

  5. Beyond the fisher-matrix formalism: exact sampling distributions of the maximum-likelihood estimator in gravitational-wave parameter estimation.

    PubMed

    Vallisneri, Michele

    2011-11-01

    Gravitational-wave astronomers often wish to characterize the expected parameter-estimation accuracy of future observations. The Fisher matrix provides a lower bound on the spread of the maximum-likelihood estimator across noise realizations, as well as the leading-order width of the posterior probability, but it is limited to high signal strengths often not realized in practice. By contrast, Monte Carlo Bayesian inference provides the full posterior for any signal strength, but it is too expensive to repeat for a representative set of noises. Here I describe an efficient semianalytical technique to map the exact sampling distribution of the maximum-likelihood estimator across noise realizations, for any signal strength. This technique can be applied to any estimation problem for signals in additive Gaussian noise. PMID:22181593

  6. Chao Formalism & Kondratenko Crossing Tests

    NASA Astrophysics Data System (ADS)

    Raymond, R. S.; Chao, A. W.; Krisch, A. D.; Leonova, M. A.; Morozov, V. S.; Sivers, D. W.; Wong, V. K.; Gebel, R.; Lehrach, A.; Lorentz, B.; Maier, R.; Prasuhn, D.; Schnase, A.; Stockhorst, H.; Hinterberger, F.; Ulbrich, K.; Kondratenko, A. M.

    2007-06-01

    We recently started testing Chao's proposed new matrix formalism for describing the spin dynamics due to a single spin resonance; this seems to be the first generalization of the Froissart-Stora equation since it was published in 1960. The Chao matrix formalism allows one to calculate analytically the polarization's behavior inside a resonance, which is not possible using the Froissart-Stora equation. We recently tested some Chao formalism predictions using a 1.85 GeV/c polarized deuteron beam stored in COSY. We swept an rf dipole's frequency through 200 Hz while varying the distance from the sweep's end frequency to an rf-induced spin resonance's central frequency. While the Froissart-Stora formula can make no prediction in this case, the data seem to support the Chao formalism. We also started investigating the new Kondratenko method to preserve beam polarization during a spin resonance crossing; the method uses 3 rapid changes of the crossing rate near the resonance. With a proper choice of crossing parameters, Kondratenko Crossing may better preserve the polarization than simple fast crossing. We tested Kondratenko's idea using 2.1 GeV/c polarized protons stored in COSY; the frequency of a ferrite rf dipole was swept though an rf-induced spin resonance using Kondratenko's crossing shape. We have not yet observed a significant advantage of Kondratenko Crossing over simple fast crossing. We plan to study it further by choosing better crossing parameters and a smaller momentum spread.

  7. Formal descriptions for formulation.

    PubMed

    This, Hervé

    2007-11-01

    Two formalisms used to describe the physical microstructure and the organization of formulated products are given. The first, called "complex disperse systems formalism" (CDS formalism) is useful for the description of the physical nature of disperse matter. The second, called "non periodical organizational space formalism" (NPOS formalism) has the same operators as the CDS formalism, but different elements; it is useful to describe the arrangement of any objects in space. Both formalisms can be viewed as the same, applied to different orders of magnitude for spatial size. PMID:17875375

  8. Interdependence of Formal Reasoning

    ERIC Educational Resources Information Center

    Berzonsky, Michael D.; And Others

    1975-01-01

    Investigated the intercorrelations among tasks that appear to require Piagetian formal reasoning to determine whether formal reasoning is used selectively or all-pervasively. Subjects were 60 undergraduate females. (SDH)

  9. Fast determination of the optimal rotational matrix for macromolecular superpositions.

    PubMed

    Liu, Pu; Agrafiotis, Dimitris K; Theobald, Douglas L

    2010-05-01

    Finding the rotational matrix that minimizes the sum of squared deviations between two vectors is an important problem in bioinformatics and crystallography. Traditional algorithms involve the inversion or decomposition of a 3 x 3 or 4 x 4 matrix, which can be computationally expensive and numerically unstable in certain cases. Here, we present a simple and robust algorithm to rapidly determine the optimal rotation using a Newton-Raphson quaternion-based method and an adjoint matrix. Our method is at least an order of magnitude more efficient than conventional inversion/decomposition methods, and it should be particularly useful for high-throughput analyses of molecular conformations. PMID:20017124

  10. More than Formal Proof.

    ERIC Educational Resources Information Center

    Hanna, Gila

    1989-01-01

    The origins of the emphasis on formal proof are discussed as well as more recent views. Factors in acceptance of a proof and the social process of acceptance by mathematicians are included. The impact of formal proof on the curriculum and implications for teaching are given. (DC)

  11. Geometry and Formal Linguistics.

    ERIC Educational Resources Information Center

    Huff, George A.

    This paper presents a method of encoding geometric line-drawings in a way which allows sets of such drawings to be interpreted as formal languages. A characterization of certain geometric predicates in terms of their properties as languages is obtained, and techniques usually associated with generative grammars and formal automata are then applied…

  12. Software Formal Inspections Guidebook

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process.

  13. Numerically stable secular equation for superlattices via transfer-matrix formalism and application to InAs/In0.23Ga0.77Sb and InAs/In0.3Ga0.7Sb/GaSb superlattices

    NASA Astrophysics Data System (ADS)

    Szmulowicz, Frank

    1998-04-01

    The numerically stable, Hermitian secular equation for superlattices within the envelope-function approximation [F. Szmulowicz, Phys. Rev. B 54, 11 539 (1996)] is derived via the transfer-matrix approach using Burt's boundary conditions. In the process, the tangents-only form of the secular equation is related to an earlier transfer matrix approach [L. R. Ram-Mohan, K. H. Yoo, and R. L. Aggarwal, Phys. Rev. B 38, 6151 (1988)] and extended to structures with an arbitrary number of layers per superlattice period. The formalism is applied to superlattices with two (InAs/In0.23Ga0.77Sb) and three (InAs/In0.3Ga0.7Sb/GaSb) layers per superlattice period, which are of interest for infrared detector and infrared cascade-laser applications, respectively.

  14. CSR-induced emittance growth in achromats: Linear formalism revisited

    NASA Astrophysics Data System (ADS)

    Venturini, M.

    2015-09-01

    We review the R-matrix formalism used to describe Coherent Synchrotron Radiation (CSR)-induced projected emittance growth in electron beam transport lines and establish the connection with a description in terms of the dispersion-invariant function.

  15. Results of an aerodynamic investigation of a space shuttle orbiter/747 carrier flight test configuration to determine separation characteristics utilizing 0.0125-scale models (48-0/AX1318I-1) in the LTV 4 x 4 foot high speed wind tunnel (CA26), volume 1

    NASA Technical Reports Server (NTRS)

    Gillins, R. L.

    1976-01-01

    Results of tests conducted on a 0.0125-scale model of the Space Shuttle Orbiter and a 0.0125-scale model of the 747 CAM configuration in a 4 x 4-foot High Speed Wind Tunnel were presented. Force and moment data were obtained for each vehicle separately at a Mach number of 0.6 and for each vehicle in proximity to the other at Mach numbers of 0.3, 0.5, 0.6 and 0.7. The proximity effects of each vehicle on the other at separation distances (from the mated configuration) ranging from 1.5 feet to 75 feet were presented; 747 Carrier angles of attack from 0 deg to 6 deg and angles of sideslip of 0 deg and -5 deg were tested. Model variables included orbiter elevon, aileron and body flap deflections, orbiter tailcone on and off, and 747 stabilizer and rudder deflections.

  16. Formalizing Probabilistic Safety Claims

    NASA Technical Reports Server (NTRS)

    Herencia-Zapana, Heber; Hagen, George E.; Narkawicz, Anthony J.

    2011-01-01

    A safety claim for a system is a statement that the system, which is subject to hazardous conditions, satisfies a given set of properties. Following work by John Rushby and Bev Littlewood, this paper presents a mathematical framework that can be used to state and formally prove probabilistic safety claims. It also enables hazardous conditions, their uncertainties, and their interactions to be integrated into the safety claim. This framework provides a formal description of the probabilistic composition of an arbitrary number of hazardous conditions and their effects on system behavior. An example is given of a probabilistic safety claim for a conflict detection algorithm for aircraft in a 2D airspace. The motivation for developing this mathematical framework is that it can be used in an automated theorem prover to formally verify safety claims.

  17. Software Formal Inspections Standard

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This Software Formal Inspections Standard (hereinafter referred to as Standard) is applicable to NASA software. This Standard defines the requirements that shall be fulfilled by the software formal inspections process whenever this process is specified for NASA software. The objective of this Standard is to define the requirements for a process that inspects software products to detect and eliminate defects as early as possible in the software life cycle. The process also provides for the collection and analysis of inspection data to improve the inspection process as well as the quality of the software.

  18. Adolescence and Formal Operations

    ERIC Educational Resources Information Center

    Blasi, A.; Hoeffel, E. C.

    1974-01-01

    Analyzes the relationship between the development of formal operations and the development of the adolescent personality, as hypothesized by Inhelder and Piaget. It is suggested that the concepts of possibility and reflectivity have a variety of meanings, and that once these meanings are examined, the logical foundation for the…

  19. Correlates of Formal Reasoning.

    ERIC Educational Resources Information Center

    Linn, Marcia C.; Pulos, Steven

    This study of Piagetian formal reasoning in seventh grade students reports the relationships between four aspects of the ability to control variables in an experiment and the relationships between those four aspects and other constructs. The four aspects of the ability to control variables identified are: (1) set up a controlled experiment, (2)…

  20. Semisymmetric systems: Hermitian formalism

    NASA Astrophysics Data System (ADS)

    Buchdahl, H. A.

    1995-04-01

    The power series representing the characteristic function of a regular semisymmetric system involves four linearly independent rotational invariants XA (A=1,.. .,4) that jointly satisfy a quadratic identity. When the X A are appropriately chosen, this takes the form -(X1)2-(X2 )2-(X3)2+( X4)2=0 . The XA are thus the components of a null vector in a four-dimensional Euclidean space whose metric is gAB: =diag(-1,-1 ,-1,1) . Such a vector is equivalent to a simple 2-spinor xi alpha . The intrinsic presence of a spin vector in the formalism used hitherto suggests that it might be of advantage to replace the latter with an explicit 2-spinor formalism. A way of doing this is examined.

  1. Formalizing the concept of sound.

    SciTech Connect

    Kaper, H. G.; Tipei, S.

    1999-08-03

    The notion of formalized music implies that a musical composition can be described in mathematical terms. In this article we explore some formal aspects of music and propose a framework for an abstract approach.

  2. Formalizing Space Shuttle Software Requirements

    NASA Technical Reports Server (NTRS)

    Crow, Judith; DiVito, Ben L.

    1996-01-01

    This paper describes two case studies in which requirements for new flight-software subsystems on NASA's Space Shuttle were analyzed, one using standard formal specification techniques, the other using state exploration. These applications serve to illustrate three main theses: (1) formal methods can complement conventional requirements analysis processes effectively, (2) formal methods confer benefits regardless of how extensively they are adopted and applied, and (3) formal methods are most effective when they are judiciously tailored to the application.

  3. An envelope function formalism for lattice-matched heterostructures

    NASA Astrophysics Data System (ADS)

    Van de Put, Maarten L.; Vandenberghe, William G.; Magnus, Wim; Sorée, Bart

    2015-08-01

    The envelope function method traditionally employs a single basis set which, in practice, relates to a single material because the k · p matrix elements are generally only known in a particular basis. In this work, we defined a basis function transformation to alleviate this restriction. The transformation is completely described by the known inter-band momentum matrix elements. The resulting envelope function equation can solve the electronic structure in lattice matched heterostructures without resorting to boundary conditions at the interface between materials, while all unit-cell averaged observables can be calculated as with the standard envelope function formalism. In the case of two coupled bands, this heterostructure formalism is equivalent to the standard formalism while taking position dependent matrix elements.

  4. k.p formalism within FLAPW method

    NASA Astrophysics Data System (ADS)

    Shishidou, Tatsuya; Oguchi, Tamio

    2009-03-01

    We provide k.p formalism within the full-potential linearized augmented plane wave (FLAPW) method. Unlike the pure plane waves, the LAPW functions do not behave trivially in moving from k to k+q and their incompleteness as a basis set should be taken into account. Derivatives of the sphere matching coefficients play the key role, for which we find a simple formula. Concrete formula for the k.p matrix elements is derived and numerically tested. Generalized second-order perturbation theory allowing for a degenerate case is presented and the literally-exact electronic band gradients and curvatures are accessible.

  5. Formal verification of AI software

    NASA Technical Reports Server (NTRS)

    Rushby, John; Whitehurst, R. Alan

    1989-01-01

    The application of formal verification techniques to Artificial Intelligence (AI) software, particularly expert systems, is investigated. Constraint satisfaction and model inversion are identified as two formal specification paradigms for different classes of expert systems. A formal definition of consistency is developed, and the notion of approximate semantics is introduced. Examples are given of how these ideas can be applied in both declarative and imperative forms.

  6. Multifractal formalisms of human behavior.

    PubMed

    Ihlen, Espen A F; Vereijken, Beatrix

    2013-08-01

    With the mounting realization that variability is an inevitable part of human behavior comes the need to integrate this phenomenon in concomitant models and theories of motor control. Among other things, this has resulted in a debate throughout the last decades about the origin of variability in behavior, the outcome of which has important implications for motor control theories. To date, a monofractal formalism of variability has been used as the basis for arguing for component- versus interaction-oriented theories of motor control. However, monofractal formalism alone cannot decide between the opposing sides of the debate. The present theoretical overview introduces multifractal formalisms as a necessary extension of the conventional monofractal formalism. In multifractal formalisms, the scale invariance of behavior is numerically defined as a spectrum of scaling exponents, rather than a single average exponent as in the monofractal formalism. Several methods to estimate the multifractal spectrum of scaling exponents - all within two multifractal formalisms called large deviation and Legendre formalism - are introduced and briefly discussed. Furthermore, the multifractal analyses within these two formalisms are applied to several performance tasks to illustrate how explanations of motor control vary with the methods used. The main section of the theoretical overview discusses the implications of multifractal extensions of the component- and interaction-oriented models for existing theories of motor control. PMID:24054900

  7. Formal, Non-Formal and Informal Learning in the Sciences

    ERIC Educational Resources Information Center

    Ainsworth, Heather L.; Eaton, Sarah Elaine

    2010-01-01

    This research report investigates the links between formal, non-formal and informal learning and the differences between them. In particular, the report aims to link these notions of learning to the field of sciences and engineering in Canada and the United States, including professional development of adults working in these fields. It offers…

  8. Unitary formalism for scattering from a hard corrugated wall

    NASA Astrophysics Data System (ADS)

    Brown, G. C.; Celli, V.; Coopersmith, M.; Haller, M.

    1982-07-01

    We obtain two coupled integral equations for the diffraction of waves from a hard corrugated surface. This rearrangement is shown to be equivalent to the integral equation for the scattering amplitude obtained by an application of the Rayleigh method. The formalism presented here, analogous to K-matrix theory, makes the unitarity of the theory apparent at each stage of approximation.

  9. NASA Formal Methods Workshop, 1990

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W. (Compiler)

    1990-01-01

    The workshop brought together researchers involved in the NASA formal methods research effort for detailed technical interchange and provided a mechanism for interaction with representatives from the FAA and the aerospace industry. The workshop also included speakers from industry to debrief the formal methods researchers on the current state of practice in flight critical system design, verification, and certification. The goals were: define and characterize the verification problem for ultra-reliable life critical flight control systems and the current state of practice in industry today; determine the proper role of formal methods in addressing these problems, and assess the state of the art and recent progress toward applying formal methods to this area.

  10. Formalism and functionalism in linguistics.

    PubMed

    Newmeyer, Frederick J

    2010-05-01

    Formalism and functionalism in linguistics are often taken to be diametrically opposed approaches. However, close examination of the relevant phenomena reveals that the two are complementary, rather than being irrevocably in opposition to each other. One can be a formal linguist and a functional linguist at the same time, without there being any contradiction. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website. PMID:26271372

  11. Complex cobordism and formal groups

    NASA Astrophysics Data System (ADS)

    Buchstaber, Viktor M.

    2012-10-01

    This paper surveys the current state of the theory of cobordism, focusing on geometric and universal properties of complex cobordism, the Landweber-Novikov algebra, and the formal group law of geometric cobordisms. The relationships with K-theory, algebraic cycles, formal group laws, compact Lie group actions on manifolds, toric topology, infinite-dimensional Lie algebras, and nilmanifolds are described. The survey contains key results and open problems. Bibliography: 124 titles.

  12. The Formal Semantics of PVS

    NASA Technical Reports Server (NTRS)

    Owre, Sam; Shankar, Natarajan

    1999-01-01

    A specification language is a medium for expressing what is computed rather than how it is computed. Specification languages share some features with programming languages but are also different in several important ways. For our purpose, a specification language is a logic within which the behavior of computational systems can be formalized. Although a specification can be used to simulate the behavior of such systems, we mainly use specifications to state and prove system properties with mechanical assistance. We present the formal semantics of the specification language of SRI's Prototype Verification System (PVS). This specification language is based on the simply typed lambda calculus. The novelty in PVS is that it contains very expressive language features whose static analysis (e.g., typechecking) requires the assistance of a theorem prover. The formal semantics illuminates several of the design considerations underlying PVS, the interaction between theorem proving and typechecking.

  13. Formal verification of mathematical software

    NASA Technical Reports Server (NTRS)

    Sutherland, D.

    1984-01-01

    Methods are investigated for formally specifying and verifying the correctness of mathematical software (software which uses floating point numbers and arithmetic). Previous work in the field was reviewed. A new model of floating point arithmetic called the asymptotic paradigm was developed and formalized. Two different conceptual approaches to program verification, the classical Verification Condition approach and the more recently developed Programming Logic approach, were adapted to use the asymptotic paradigm. These approaches were then used to verify several programs; the programs chosen were simplified versions of actual mathematical software.

  14. A formalism and computer program for coupled lattices

    SciTech Connect

    Raubenheimer, T.O.

    1989-04-01

    In this paper, a formalism to calculate the lattice functions and emittances of a coupled electron/positron storage ring is presented. The lattice functions are calculated directly from the modal matrix of the betatron transport matrix for the ring. The emittances and damping rates are then calculated from the invariants found in the diagonalized representation. In addition, a computer program is described which uses the formalism to calculate the coupled lattice functions, emittances and damping rates. The program can either reconstruct the closed orbit from BPM data and dipole corrector strengths, or construct an orbit from misalignments entered into the the lattice and then optionally correct the orbit with dipole correctors. The lattice functions, emittances, etc. are then calculated about the resulting closed orbit. 7 refs.

  15. A Formalization of Student Modeling.

    ERIC Educational Resources Information Center

    Danna, Frederic; Sebillot, Pascale

    1997-01-01

    Focuses on student modeling within an Intelligent Tutoring System. Describes three domain-independent properties that the formalism representing student knowledge and the processes synthesizing this knowledge must possess to build accurate student models for second-language learning. Notes when, how, and where hypothetical reasoning mechanisms…

  16. Ambitwistor string theory in the operator formalism

    NASA Astrophysics Data System (ADS)

    Reid-Edwards, R. A.

    2016-06-01

    After a brief overview of the operator formalism for conventional string theory, an operator formalism for ambitwistor string theory is presented. It is shown how tree level supergravity scattering amplitudes are recovered in this formalism. More general applications of this formalism to loop amplitudes and the construction of an ambitwistor string field theory are briefly discussed.

  17. Matrix superpotentials

    NASA Astrophysics Data System (ADS)

    Nikitin, Anatoly G.; Karadzhov, Yuri

    2011-07-01

    We present a collection of matrix-valued shape invariant potentials which give rise to new exactly solvable problems of SUSY quantum mechanics. It includes all irreducible matrix superpotentials of the generic form W=kQ+\\frac{1}{k} R+P, where k is a variable parameter, Q is the unit matrix multiplied by a real-valued function of independent variable x, and P and R are the Hermitian matrices depending on x. In particular, we recover the Pron'ko-Stroganov 'matrix Coulomb potential' and all known scalar shape invariant potentials of SUSY quantum mechanics. In addition, five new shape invariant potentials are presented. Three of them admit a dual shape invariance, i.e. the related Hamiltonians can be factorized using two non-equivalent superpotentials. We find discrete spectrum and eigenvectors for the corresponding Schrödinger equations and prove that these eigenvectors are normalizable.

  18. Notoph gauge theory: Superfield formalism

    NASA Astrophysics Data System (ADS)

    Malik, R. P.

    2011-05-01

    We derive absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for the 4D free Abelian 2-form gauge theory by exploiting the superfield approach to BRST formalism. The antisymmetric tensor gauge field of the above theory was christened as the "notoph" (i.e. the opposite of "photon") gauge field by Ogievetsky and Palubarinov way back in 1966-67. We briefly outline the problems involved in obtaining the absolute anticonimutativity of the (anti-) BRST transformations and their resolution within the framework of geometrical superfield approach to BRST formalism. One of the highlights of our results is the emergence of a Curci-Ferrari type of restriction in the context of 4D Abelian 2-form (notoph) gauge theory which renders the nilpotent (anti-) BRST symmetries of the theory to be absolutely anticommutative in nature.

  19. Formal Analysis of Message Passing

    NASA Astrophysics Data System (ADS)

    Siegel, Stephen F.; Gopalakrishnan, Ganesh

    The message passing paradigm underlies many important families of programs - for instance programs in the area of high performance computing that support science and engineering research. Unfortunately, very few formal methods researchers are involved in developing formal analysis tools and techniques for message passing programs. This paper summarizes research being done in our groups in support of this area, specifically with respect to the Message Passing Interface. We emphasize the need for specialized varieties of many familiar notions such as deadlock detection, race analysis, symmetry analysis, partial order reduction, static analysis and symbolic reasoning support. Since these issues are harbingers of those being faced in multicore programming, the time is ripe to build a critical mass of researchers working in this area.

  20. Formal total synthesis of platencin.

    PubMed

    Varseev, Georgy N; Maier, Martin E

    2009-01-01

    The right bicycle: A concise formal synthesis of platencin was based on an efficient oxygen-mediated palladium-catalyzed cycloalkenylation of 1 to form a bicyclo[3.2.1]octane, and a deoxygenative rearrangement of tosylhydrazone 2 to construct the bicyclo[2.2.2]octane 3. The total yield of the core structure 4 of platencin was 17.5% for 13 steps from a commercially available compound. Ts = p-toluenesulfonyl, TBS = tert-butyldimethylsilyl, Piv = pivaloyl. PMID:19353600

  1. Formal Validation of Aerospace Software

    NASA Astrophysics Data System (ADS)

    Lesens, David; Moy, Yannick; Kanig, Johannes

    2013-08-01

    Any single error in critical software can have catastrophic consequences. Even though failures are usually not advertised, some software bugs have become famous, such as the error in the MIM-104 Patriot. For space systems, experience shows that software errors are a serious concern: more than half of all satellite failures from 2000 to 2003 involved software. To address this concern, this paper addresses the use of formal verification of software developed in Ada.

  2. Formalizing narratives using nested circumscription

    SciTech Connect

    Baral, C.; Gabaldon, A.; Provetti, A.

    1996-12-31

    The representation of narratives of actions and observations is a current issue in Knowledge Representation, where traditional plan-oriented treatments of action seem to fall short. To address narratives, Pinto and Reiter have extended Situation Calculus axioms, Kowalski and Sergot have introduced the Event Calculus in Logic Programming, and Baral et al. have defined the specification language L which allows to express actual and hypothetical situations in a uniform setting. The L entailment relation can formalize several forms of reasoning about actions and change. In this paper we illustrate a translation of L theories into Nested Abnormality Theories, a novel form of circumscription. The proof of soundness and completeness of the translation is the main technical result of the paper, but attention is also devoted to the features of Nested Abnormality Theories to capture commonsense reasoning in general and to clarify which assumptions a logical formalization forces upon a domain. These results also help clarifying the relationship between L and other recent circumscriptive formalization for narratives, such as Miller and Shanahan`s.

  3. Knowledge formalization of intelligent building

    NASA Astrophysics Data System (ADS)

    Žáček, Martin

    2016-06-01

    This article aim is understanding the basic knowledge about an intelligent building. The notion of the intelligent building can be called any building equipped with computer and communication technology, which can automatically respond to internal or external stimuli. The result of the intelligent building is an automated and foreseeing of activities that enable to reduce operating costs and increase comfort. The best way to use the intelligent building is for a low-energy building, a passive building, or for building with high savings. The output of this article is the formalization of basic knowledge of the intelligent building by RDF graph.

  4. On Vasyliunas's equivalent conductivity formalism

    NASA Technical Reports Server (NTRS)

    Pontius, D. H., Jr.

    1992-01-01

    The Vasyliunas's (1972) equivalent conductivity formalism (ECF) for representing the coupling of the ionosphere and the magnetosphere is discussed, and a new, simpler, derivation is presented of the ECF, in which certain of the underlying assumptions and their implications are made transparent. The derivation presented indicates that the only role of the ions in the ECF is to insure quasi-neutrality. It is shown that the ECF is not as robust as usually assumed and that caution must be used to insure that reasonable results are obtained.

  5. 47 CFR 8.12 - Formal complaints.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Formal complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  6. 47 CFR 8.12 - Formal complaints.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Formal complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  7. 47 CFR 8.12 - Formal complaints.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Formal complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  8. 47 CFR 8.12 - Formal Complaints.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Formal Complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal Complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  9. Sync Matrix

    Energy Science and Technology Software Center (ESTSC)

    2004-12-31

    Sync Matrix provides a graphic display of the relationships among all of the response activities of each jurisdiction. This is accomplished through software that organizes and displays the activities by jurisdiction, function, and time for easy review and analysis. The software can also integrate the displays of multiple jurisdictions to allow examination of the total response.

  10. The Product Operator Formalism: A Physical and Graphical Interpretation

    PubMed Central

    Goldenberg, David P.

    2010-01-01

    The product-operator formalism is the most commonly used tool for describing and designing multidimensional NMR experiments. In spite of its relative simplicity and sound theoretical underpinnings, however, students and practitioners often find it difficult to relate the mathematical manipulations to a physical picture. In an effort to address this pedagogical challenge, the present paper begins with a quantum-mechanical treatment of pure populations of scalar-coupled spin-pairs, rather than the equilibrium population of spin-pairs in different quantum states, which is the usual starting point for treatments based on the density matrix and product operators. In the context of pure populations, the product operators are shown to represent quantum correlations between the nuclei in individual molecules, and a new variation on the classical vector diagram is introduced to represent these correlations. The treatment is extended to mixed populations that begin at thermal equilibrium, and the density matrix is introduced as an efficient means of carrying out quantum calculations for a mixed population. Finally, it is shown that the operators for observable magnetization and correlations can be used as a basis set for the density matrix, providing the formal justification for the widely-used rules of the product-operator treatment. Throughout the discussion, the vector diagrams are used to help maintain a connection between the mathematics and the sometimes subtle physical principles. An electronic supplement created with the Mathematica computer program is used to provide additional mathematical details and the means to carry out further calculations. PMID:21552432

  11. A Formal Model for Real-Time Parallel Computation

    SciTech Connect

    Hui, Peter SY; Chikkagoudar, Satish

    2012-12-29

    The imposition of real-time constraints on a parallel computing environment--- specifically high-performance, cluster-computing systems--- introduces a variety of challenges with respect to the formal verification of the system's timing properties. In this paper, we briefly motivate the need for such a system, and we introduce an automaton-based method for performing such formal verification. We define the concept of a consistent parallel timing system: a hybrid system consisting of a set of timed automata (specifically, timed Buechi automata as well as a timed variant of standard finite automata), intended to model the timing properties of a well-behaved real-time parallel system. Finally, we give a brief case study to demonstrate the concepts in the paper: a parallel matrix multiplication kernel which operates within provable upper time bounds. We give the algorithm used, a corresponding consistent parallel timing system, and empirical results showing that the system operates under the specified timing constraints.

  12. Heat kernel expansion in the background field formalism

    NASA Astrophysics Data System (ADS)

    Barvinsky, Andrei O.

    2015-06-01

    Heat kernel expansion and background field formalism represent the combination of two calculational methods within the functional approach to quantum field theory. This approach implies construction of generating functionals for matrix elements and expectation values of physical observables. These are functionals of arbitrary external sources or the mean field of a generic configuration -- the background field. Exact calculation of quantum effects on a generic background is impossible. However, a special integral (proper time) representation for the Green's function of the wave operator -- the propagator of the theory -- and its expansion in the ultraviolet and infrared limits of respectively short and late proper time parameter allow one to construct approximations which are valid on generic background fields. Current progress of quantum field theory, its renormalization properties, model building in unification of fundamental physical interactions and QFT applications in high energy physics, gravitation and cosmology critically rely on efficiency of the heat kernel expansion and background field formalism.

  13. A FORMALISM FOR COVARIANT POLARIZED RADIATIVE TRANSPORT BY RAY TRACING

    SciTech Connect

    Gammie, Charles F.; Leung, Po Kin

    2012-06-20

    We write down a covariant formalism for polarized radiative transfer appropriate for ray tracing through a turbulent plasma. The polarized radiation field is represented by the polarization tensor (coherency matrix) N{sup {alpha}{beta}} {identical_to} (a{sup {alpha}}{sub k} a*{sup {beta}}{sub k}), where a{sub k} is a Fourier coefficient for the vector potential. Using Maxwell's equations, the Liouville-Vlasov equation, and the WKB approximation, we show that the transport equation in vacuo is k{sup {mu}}{nabla}{sub {mu}} N{sup {alpha}{beta}} = 0. We show that this is equivalent to Broderick and Blandford's formalism based on invariant Stokes parameters and a rotation coefficient, and suggest a modification that may reduce truncation error in some situations. Finally, we write down several alternative approaches to integrating the transfer equation.

  14. Formal Methods at Intel - An Overview

    NASA Technical Reports Server (NTRS)

    Harrison, John

    2010-01-01

    Since the 1990s, Intel has invested heavily in formal methods, which are now deployed in several domains: hardware, software, firmware, protocols etc. Many different formal methods tools and techniques are in active use, including symbolic trajectory evaluation, temporal logic model checking, SMT-style combined decision procedures, and interactive higher-order logic theorem proving. I will try to give a broad overview of some of the formal methods activities taking place at Intel, and describe the challenges of extending formal verification to new areas and of effectively using multiple formal techniques in combination

  15. Formal methods technology transfer: Some lessons learned

    NASA Technical Reports Server (NTRS)

    Hamilton, David

    1992-01-01

    IBM has a long history in the application of formal methods to software development and verification. There have been many successes in the development of methods, tools and training to support formal methods. And formal methods have been very successful on several projects. However, the use of formal methods has not been as widespread as hoped. This presentation summarizes several approaches that have been taken to encourage more widespread use of formal methods, and discusses the results so far. The basic problem is one of technology transfer, which is a very difficult problem. It is even more difficult for formal methods. General problems of technology transfer, especially the transfer of formal methods technology, are also discussed. Finally, some prospects for the future are mentioned.

  16. A Comparison of Participation Patterns in Selected Formal, Non-Formal, and Informal Online Learning Environments

    ERIC Educational Resources Information Center

    Schwier, Richard A.; Seaton, J. X.

    2013-01-01

    Does learner participation vary depending on the learning context? Are there characteristic features of participation evident in formal, non-formal, and informal online learning environments? Six online learning environments were chosen as epitomes of formal, non-formal, and informal learning contexts and compared. Transcripts of online…

  17. On solving for the density matrix

    NASA Astrophysics Data System (ADS)

    Cummings, F. W.

    1985-11-01

    A “generating matrix” formalism is presented which is useful in the solution of a class of time-dependent quantum density matrix problems. Three examples of its use are sketched, giving a unified approach to the solution of the problem of the spontaneous emission of electromagnetic radiation from a single atom in various environments.

  18. Formal modeling of virtual machines

    NASA Technical Reports Server (NTRS)

    Cremers, A. B.; Hibbard, T. N.

    1978-01-01

    Systematic software design can be based on the development of a 'hierarchy of virtual machines', each representing a 'level of abstraction' of the design process. The reported investigation presents the concept of 'data space' as a formal model for virtual machines. The presented model of a data space combines the notions of data type and mathematical machine to express the close interaction between data and control structures which takes place in a virtual machine. One of the main objectives of the investigation is to show that control-independent data type implementation is only of limited usefulness as an isolated tool of program development, and that the representation of data is generally dictated by the control context of a virtual machine. As a second objective, a better understanding is to be developed of virtual machine state structures than was heretofore provided by the view of the state space as a Cartesian product.

  19. The distinguishable cluster approach from a screened Coulomb formalism.

    PubMed

    Kats, Daniel

    2016-01-28

    The distinguishable cluster doubles equations have been derived starting from an effective screened Coulomb formalism and a particle-hole symmetric formulation of the Fock matrix. A perturbative triples correction to the distinguishable cluster with singles and doubles (DCSD) has been introduced employing the screened integrals. It is shown that the resulting DCSD(T) method is more accurate than DCSD for reaction energies and is less sensitive to the static correlation than coupled cluster with singles and doubles with a perturbative triples correction. PMID:26827197

  20. Floquet Green function formalism for harmonically driven Hamiltonians

    NASA Astrophysics Data System (ADS)

    Martinez, D. F.

    2003-09-01

    A method is proposed for the calculation of the Floquet-Green function of a general Hamiltonian with harmonic time dependence. We use matrix continued fractions to derive an expression for the 'dynamical effective potential' that can be used to calculate the Floquet-Green function of the system. We demonstrate the formalism for the simple case of a space-periodic (in the tight-binding approximation) Hamiltonian with a defect whose on-site energy changes harmonically with time. We study the local density of states for this system and the behaviour of the localized states as a function of the different parameters that characterize the system.

  1. Measurement-feedback formalism meets information reservoirs

    NASA Astrophysics Data System (ADS)

    Shiraishi, Naoto; Matsumoto, Takumi; Sagawa, Takahiro

    2016-01-01

    There have been two distinct formalisms of thermodynamics of information: one is the measurement-feedback formalism, which concerns bipartite systems with measurement and feedback processes, and the other is the information reservoir formalism, which considers bit sequences as a thermodynamic fuel. In this paper, we derive a second-law-like inequality by applying the measurement-feedback formalism to information reservoirs, which provides a stronger bound of extractable work than any other known inequality in the same setup. In addition, we demonstrate that the Mandal-Jarzynski model, which is a prominent model of the information reservoir formalism, is equivalent to a model obtained by the contraction of a bipartite system with autonomous measurement and feedback. Our results provide a unified view on the measurement-feedback and the information-reservoir formalisms.

  2. Relativistic Dipole Matrix Element Zeros

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2002-05-01

    There is a special class of relativistic high energy dipole matrix element zeros (RZ), whose positions with respect to photon energy ω , only depend on the bound state l quantum number according to ω^0=mc^2/(l_b+1) (independent of primary quantum number n, nuclear charge Z, central potential V and dipole retardation). These RZ only occur in (n,l_b,j_b)arrow (ɛ , l_b+1,j_b) transitions such as ns_1/2arrow ɛ p_1/2; np_3/2arrow ɛ d_3/2: nd_5/2arrow ɛ f_5/2 etc. The nonrelativistic limit of these matrix elements can be established explicitly in the Coulomb case. Within the general matrix element formalism (such as that in [1]); when |κ | is substituted for γ in analytic expressions for matrix elements, the zeros remain, but ω^0 now becomes dependent on n and Z. When the reduction to nonrelativistic form is completed by application of the low energy approximation ω mc^2 mc^2, the zeros disappear. This nonzero behavior was noted in nonrelativistic dipole Coulomb matrix elements by Fano and Cooper [2] and later proven by Oh and Pratt[3]. (J. H. Scofield, Phys. Rev. A 40), 3054 (1989 (U. Fano and J. W. Cooper, Rev. Mod. Phys. 40), 441 (1968). (D. Oh and R. H. Pratt, Phys. Rev. A 34), 2486 (1986); 37, 1524 (1988); 45, 1583 (1992).

  3. Survey of Existing Tools for Formal Verification.

    SciTech Connect

    Punnoose, Ratish J.; Armstrong, Robert C.; Wong, Matthew H.; Jackson, Mayo

    2014-12-01

    Formal methods have come into wide use because of their effectiveness in verifying "safety and security" requirements of digital systems; a set of requirements for which testing is mostly ineffective. Formal methods are routinely used in the design and verification of high-consequence digital systems in industry. This report outlines our work in assessing the capabilities of commercial and open source formal tools and the ways in which they can be leveraged in digital design workflows.

  4. Anyons in the operational formalism

    SciTech Connect

    Neori, Klil H.; Goyal, Philip

    2015-01-13

    The operational formalism to quantum mechanics seeks to base the theory on a firm foundation of physically well-motivated axioms [1]. It has succeeded in deriving the Feynman rules [2] for general quantum systems. Additional elaborations have applied the same logic to the question of identical particles, confirming the so-called Symmetrization Postulate [3]: that the only two options available are fermions and bosons [4, 5]. However, this seems to run counter to results in two-dimensional systems, which allow for anyons, particles with statistics which interpolate between Fermi-Dirac and Bose-Einstein (see [6] for a review). In this talk we will show that the results in two dimensions can be made compatible with the operational results. That is, we will show that anyonic behavior is a result of the topology of the space in two dimensions [7], and does not depend on the particles being identical; but that nevertheless, if the particles are identical, the resulting system is still anyonic.

  5. Anyons in the operational formalism

    NASA Astrophysics Data System (ADS)

    Neori, Klil H.; Goyal, Philip

    2015-01-01

    The operational formalism to quantum mechanics seeks to base the theory on a firm foundation of physically well-motivated axioms [1]. It has succeeded in deriving the Feynman rules [2] for general quantum systems. Additional elaborations have applied the same logic to the question of identical particles, confirming the so-called Symmetrization Postulate [3]: that the only two options available are fermions and bosons [4, 5]. However, this seems to run counter to results in two-dimensional systems, which allow for anyons, particles with statistics which interpolate between Fermi-Dirac and Bose-Einstein (see [6] for a review). In this talk we will show that the results in two dimensions can be made compatible with the operational results. That is, we will show that anyonic behavior is a result of the topology of the space in two dimensions [7], and does not depend on the particles being identical; but that nevertheless, if the particles are identical, the resulting system is still anyonic.

  6. Universal formalism of Fano resonance

    SciTech Connect

    Huang, Liang; Lai, Ying-Cheng; Luo, Hong-Gang; Grebogi, Celso

    2015-01-15

    The phenomenon of Fano resonance is ubiquitous in a large variety of wave scattering systems, where the resonance profile is typically asymmetric. Whether the parameter characterizing the asymmetry should be complex or real is an issue of great experimental interest. Using coherent quantum transport as a paradigm and taking into account of the collective contribution from all available scattering channels, we derive a universal formula for the Fano-resonance profile. We show that our formula bridges naturally the traditional Fano formulas with complex and real asymmetry parameters, indicating that the two types of formulas are fundamentally equivalent (except for an offset). The connection also reveals a clear footprint for the conductance resonance during a dephasing process. Therefore, the emergence of complex asymmetric parameter when fitting with experimental data needs to be properly interpreted. Furthermore, we have provided a theory for the width of the resonance, which relates explicitly the width to the degree of localization of the close-by eigenstates and the corresponding coupling matrices or the self-energies caused by the leads. Our work not only resolves the issue about the nature of the asymmetry parameter, but also provides deeper physical insights into the origin of Fano resonance. Since the only assumption in our treatment is that the transport can be described by the Green’s function formalism, our results are also valid for broad disciplines including scattering problems of electromagnetic waves, acoustics, and seismology.

  7. Formal Methods for Life-Critical Software

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Johnson, Sally C.

    1993-01-01

    The use of computer software in life-critical applications, such as for civil air transports, demands the use of rigorous formal mathematical verification procedures. This paper demonstrates how to apply formal methods to the development and verification of software by leading the reader step-by-step through requirements analysis, design, implementation, and verification of an electronic phone book application. The current maturity and limitations of formal methods tools and techniques are then discussed, and a number of examples of the successful use of formal methods by industry are cited.

  8. Third NASA Langley Formal Methods Workshop

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael (Compiler)

    1995-01-01

    This publication constitutes the proceedings of NASA Langley Research Center's third workshop on the application of formal methods to the design and verification of life-critical systems. This workshop brought together formal methods researchers, industry engineers, and academicians to discuss the potential of NASA-sponsored formal methods and to investigate new opportunities for applying these methods to industry problems. contained herein are copies of the material presented at the workshop, summaries of many of the presentations, a complete list of attendees, and a detailed summary of the Langley formal methods program. Much of this material is available electronically through the World-Wide Web via the following URL.

  9. The Second NASA Formal Methods Workshop 1992

    NASA Technical Reports Server (NTRS)

    Johnson, Sally C. (Compiler); Holloway, C. Michael (Compiler); Butler, Ricky W. (Compiler)

    1992-01-01

    The primary goal of the workshop was to bring together formal methods researchers and aerospace industry engineers to investigate new opportunities for applying formal methods to aerospace problems. The first part of the workshop was tutorial in nature. The second part of the workshop explored the potential of formal methods to address current aerospace design and verification problems. The third part of the workshop involved on-line demonstrations of state-of-the-art formal verification tools. Also, a detailed survey was filled in by the attendees; the results of the survey are compiled.

  10. Multifractal formalism and anisotropic selfsimilar functions

    NASA Astrophysics Data System (ADS)

    Ben Slimane, Mourad

    1998-09-01

    In this paper we prove that the conjectures of Frisch and Parisi and Arneodo et al. (called the multifractal formalism for functions) may fail for some non-homogeneous selfsimilar functions on [open face R]2. In these cases, we compute the correct spectrum of singularities and we show how the multifractal formalism must be modified.

  11. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Formal intervention. 3001.20 Section 3001.20... Applicability § 3001.20 Formal intervention. (a) Who may intervene. A notice of intervention will be entertained... interest of such nature that intervention is allowed by the Act, or appropriate to its administration....

  12. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Formal intervention. 3001.20 Section 3001.20... Applicability § 3001.20 Formal intervention. (a) Who may intervene. A notice of intervention will be entertained... interest of such nature that intervention is allowed by the Act, or appropriate to its administration....

  13. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Formal intervention. 3001.20 Section 3001.20... Applicability § 3001.20 Formal intervention. (a) Who may intervene. A notice of intervention will be entertained... interest of such nature that intervention is allowed by the Act, or appropriate to its administration....

  14. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Formal intervention. 3001.20 Section 3001.20... Applicability § 3001.20 Formal intervention. Link to an amendment published at 79 FR 33407, June 10, 2014. (a) Who may intervene. A notice of intervention will be entertained in those cases that are noticed for...

  15. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Formal intervention. 3001.20 Section 3001.20... Applicability § 3001.20 Formal intervention. (a) Who may intervene. A notice of intervention will be entertained... interest of such nature that intervention is allowed by the Act, or appropriate to its administration....

  16. 18 CFR 1b.5 - Formal investigations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Formal investigations. 1b.5 Section 1b.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.5 Formal investigations....

  17. Do Formal Supports Replace Informal Supports?

    ERIC Educational Resources Information Center

    Barer, Barbara M.; And Others

    Health policy researchers have long been interested in the extent to which the provision of formal supports replaces or undermines the informal support system. This study examined the linkages between the formal and informal support system as they are mediated by a health care setting which readily provides patients with access to social services.…

  18. Restorative Practices as Formal and Informal Education

    ERIC Educational Resources Information Center

    Carter, Candice C.

    2013-01-01

    This article reviews restorative practices (RP) as education in formal and informal contexts of learning that are fertile sites for cultivating peace. Formal practices involve instruction about response to conflict, while informal learning occurs beyond academic lessons. The research incorporated content analysis and a critical examination of the…

  19. Formal Moral Education and Individual Moral Development.

    ERIC Educational Resources Information Center

    Friend, Gary Gene

    This report provides a summarization of a study designed to determine if there is a significant relationship between formal religious education and the moral judgment development of college students, and after controlling for formal religious education, to see if there was also a significant relationship between the educational environment or…

  20. Male-Female Differences in Formal Thought.

    ERIC Educational Resources Information Center

    Linn, Marcia C.

    Two studies were conducted to clarify the influence of experiences and aptitudes on male-female differences in formal thought. Participants were 788 seventh-, ninth-, and eleventh-graders in three school districts differing in location, socioeconomic composition, and course offerings. Formal thought was measured with tasks involving proportional…

  1. Does (In)Formal Learning Enhance Employability?

    ERIC Educational Resources Information Center

    van der Heijden, Beatrice I.J.M.; Boon, Jo; van der Klink, Marcel R.; Meys, Ely

    2008-01-01

    Not much is known about the actual contribution of informal learning to employability over and above formal learning activities. This paper presents findings of a research project among university staff members and is aimed to determine the contribution of formal and informal learning activities in the light of future career potential. Findings…

  2. Methodological imperfection and formalizations in scientific activity

    SciTech Connect

    Svetlichny, G.

    1987-03-01

    Any mathematical formalization of scientific activity allows for imperfections in the methodology that is formalized. These can be of three types, dirty, rotten, and dammed. Restricting mathematical attention to those methods that cannot be construed to be imperfect drastically reduces the class of objects that must be analyzed, and related all other objects to these more regular ones. Examples are drawn from empirical logic.

  3. Multiverse in the Third Quantized Formalism

    NASA Astrophysics Data System (ADS)

    Mir, Faizal

    2014-11-01

    In this paper we will analyze the third quantization of gravity in path integral formalism. We will use the time-dependent version of Wheeler—DeWitt equation to analyze the multiverse in this formalism. We will propose a mechanism for baryogenesis to occur in the multiverse, without violating the baryon number conservation.

  4. 14 CFR 302.404 - Formal complaints.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Formal complaints. 302.404 Section 302.404 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) PROCEDURAL... business or the ends of justice. (e) Service. A formal complaint, and any amendments thereto, shall...

  5. Formal hardware verification of digital circuits

    NASA Technical Reports Server (NTRS)

    Joyce, J.; Seger, C.-J.

    1991-01-01

    The use of formal methods to verify the correctness of digital circuits is less constrained by the growing complexity of digital circuits than conventional methods based on exhaustive simulation. This paper briefly outlines three main approaches to formal hardware verification: symbolic simulation, state machine analysis, and theorem-proving.

  6. 37 CFR 251.41 - Formal hearings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ARBITRATION ROYALTY PANEL RULES AND PROCEDURES COPYRIGHT ARBITRATION ROYALTY PANEL RULES OF PROCEDURE Procedures of Copyright Arbitration Royalty Panels § 251.41 Formal hearings. (a) The formal hearings that... distribution hearings. All parties intending to participate in a hearing of a Copyright Arbitration...

  7. Integrating Formal and Informal Learning at Work

    ERIC Educational Resources Information Center

    Svensson, Lennart; Ellstrom, Per-Erik; Aberg, Carina

    2004-01-01

    A model for workplace learning is presented, which intends to integrate formal and informal learning with the use of e-learning. An important underlying assumption is that the integration of formal and informal learning is necessary in order to create desirable competencies, from both an individual and an organisational perspective. Two case…

  8. 37 CFR 251.41 - Formal hearings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ARBITRATION ROYALTY PANEL RULES AND PROCEDURES COPYRIGHT ARBITRATION ROYALTY PANEL RULES OF PROCEDURE Procedures of Copyright Arbitration Royalty Panels § 251.41 Formal hearings. (a) The formal hearings that... distribution hearings. All parties intending to participate in a hearing of a Copyright Arbitration...

  9. Novel all-optical planar and compact minimum-stage switches of size >= 4x4

    NASA Astrophysics Data System (ADS)

    Giglmayr, Josef

    1997-01-01

    Throughout the paper, novel all-optical planar 1-stage k multiplied by k-switches and compact minimum-stage k multiplied by k-switches in double-layer and multi-layer technique, are presented and analyzed. In the first case, the number of k(k - 1)/2 switches of size 2 multiplied by 2 (equivalent minimum of the Spanke-Benes network) are arranged in parallel instead of the number of k (equivalent maximum) cascaded 2 multiplied by 2-switches of the Spanke- Benes network. In the second case, the number of 2 multiplied by 2-switches depends on the geometry of the 'pipes' of the switches formed by the layers and waveguides [for a square it is 3k/2(k/2 - 1) for rearrangeable nonblocking and 3(k - 1)k/2(k/2 - 1) for circuit switching networks]. The number of stages (NS) (horizontal cascaded) of the proposed compact switches for the nonblocking interconnection is NS equals n - 1 if the waveguides form an n-gon (n greater than or equal to 3) for any size of the k multiplied by k-switch. In this way, the attenuation of optical signals passing through a photonic network may be minimized. In particular, for any size of a k multiplied by k-switch, dependent on the n-gon, the minimum NS is n-1 equals 2 (triangle) or n - 1 equals 3 (square) etc. Thus the proposed switch concept is of complexity O(1), i.e. the NS is independent of the number of inputs/outputs. Additionally, the proposed switches are capable to operate in the circuit switching mode if and only if (iff) the parallelism increases by the factor k-1.

  10. Unified formalism for nonautonomous mechanical systems

    NASA Astrophysics Data System (ADS)

    Barbero-Liñán, María; Echeverría-Enríquez, Arturo; Diego, David Martín de; Muñoz-Lecanda, Miguel C.; Román-Roy, Narciso

    2008-06-01

    We present a unified geometric framework for describing both the Lagrangian and Hamiltonian formalisms of regular and nonregular time-dependent mechanical systems, which is based on the approach of Skinner and Rusk ["Generalized Hamiltonian dynamics I. Formulation on T*Q⊗TQ," J. Math. Phys. 24, 2589 (1983)]. The dynamical equations of motion and their compatibility and consistency are carefully studied, making clear that all the characteristics of the Lagrangian and the Hamiltonian formalisms are recovered in this formulation. As an example, a semidiscretization of the nonlinear wave equation is studied, proving the applicability of the proposed formalism.

  11. Experiences Using Formal Methods for Requirements Modeling

    NASA Technical Reports Server (NTRS)

    Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David

    1996-01-01

    This paper describes three cases studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, the formal modeling provided a cost effective enhancement of the existing verification and validation processes. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations.

  12. Further Examination of Formal Operational Reasoning Abilities.

    ERIC Educational Resources Information Center

    Roberge, James J.; Flexer, Barbara K.

    1979-01-01

    Three paper-and-pencil formal operations tests were administered to groups of eighth graders and adults. These measures provided scores that indicated each subject's level of reasoning for three second-order operations: combinations, proportionality, and propositional logic. (JMB)

  13. Open systems & non-formal education

    NASA Astrophysics Data System (ADS)

    Wheeler, Gerald F.

    1988-10-01

    Professor Dib created an important structure that can be used to attach the many and various activities that fall in the category of this title. While I plan to use his structure, I will be emphasizing a different component of his spectrum and promoting a different need. Professor Dib suggested a critical need to move our teaching styles away from formal modes to non-formal modes of delivery. I suggest an equally critical need in the area of informal education. And, I will propose aways to move us toward the same goal, non-formal activities. I believe we need to find ways to use the many informal education activities that occur almost automatically in our societies to move our potential learners to richer non-formal endeavors. Both needs are real; both activities are valid.

  14. Formal specification of human-computer interfaces

    NASA Technical Reports Server (NTRS)

    Auernheimer, Brent

    1990-01-01

    A high-level formal specification of a human computer interface is described. Previous work is reviewed and the ASLAN specification language is described. Top-level specifications written in ASLAN for a library and a multiwindow interface are discussed.

  15. Importance of Reversibility in the Quantum Formalism

    NASA Astrophysics Data System (ADS)

    David, François

    2011-10-01

    In this Letter I stress the role of causal reversibility (time symmetry), together with causality and locality, in the justification of the quantum formalism. First, in the algebraic quantum formalism, I show that the assumption of reversibility implies that the observables of a quantum theory form an abstract real C⋆ algebra, and can be represented as an algebra of operators on a real Hilbert space. Second, in the quantum logic formalism, I emphasize which axioms for the lattice of propositions (the existence of an orthocomplementation and the covering property) derive from reversibility. A new argument based on locality and Soler’s theorem is used to derive the representation as projectors on a regular Hilbert space from the general quantum logic formalism. In both cases it is recalled that the restriction to complex algebras and Hilbert spaces comes from the constraints of locality and separability.

  16. A non-commuting stabilizer formalism

    SciTech Connect

    Ni, Xiaotong; Van den Nest, Maarten; Buerschaper, Oliver

    2015-05-15

    We propose a non-commutative extension of the Pauli stabilizer formalism. The aim is to describe a class of many-body quantum states which is richer than the standard Pauli stabilizer states. In our framework, stabilizer operators are tensor products of single-qubit operators drawn from the group 〈αI, X, S〉, where α = e{sup iπ/4} and S = diag(1, i). We provide techniques to efficiently compute various properties related to bipartite entanglement, expectation values of local observables, preparation by means of quantum circuits, parent Hamiltonians, etc. We also highlight significant differences compared to the Pauli stabilizer formalism. In particular, we give examples of states in our formalism which cannot arise in the Pauli stabilizer formalism, such as topological models that support non-Abelian anyons.

  17. The Intersituational Generality of Formal Thought

    ERIC Educational Resources Information Center

    Stone, Mary Ann; Ausubel, David P.

    1969-01-01

    Shows that, contrary to Piagetian Theory, formal thought in a variety of subject matters is not possible until sufficient requisite concrete background experience in each content area involved has been attained. (MH)

  18. Why Engineers Should Consider Formal Methods

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael

    1997-01-01

    This paper presents a logical analysis of a typical argument favoring the use of formal methods for software development, and suggests an alternative argument that is simpler and stronger than the typical one.

  19. Transitions from Formal Education to the Workplace

    ERIC Educational Resources Information Center

    Olson, Joann S.

    2014-01-01

    This chapter frames the transition to adulthood in the context of the moving from formal educational settings to the often less-structured learning that occurs in workplace settings. Although schooling may end, learning continues.

  20. General formalism for singly thermostated Hamiltonian dynamics.

    PubMed

    Ramshaw, John D

    2015-11-01

    A general formalism is developed for constructing modified Hamiltonian dynamical systems which preserve a canonical equilibrium distribution by adding a time evolution equation for a single additional thermostat variable. When such systems are ergodic, canonical ensemble averages can be computed as dynamical time averages over a single trajectory. Systems of this type were unknown until their recent discovery by Hoover and colleagues. The present formalism should facilitate the discovery, construction, and classification of other such systems by encompassing a wide class of them within a single unified framework. This formalism includes both canonical and generalized Hamiltonian systems in a state space of arbitrary dimensionality (either even or odd) and therefore encompasses both few- and many-particle systems. Particular attention is devoted to the physical motivation and interpretation of the formalism, which largely determine its structure. An analogy to stochastic thermostats and fluctuation-dissipation theorems is briefly discussed. PMID:26651677

  1. Design for validation, based on formal methods

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.

    1990-01-01

    Validation of ultra-reliable systems decomposes into two subproblems: (1) quantification of probability of system failure due to physical failure; (2) establishing that Design Errors are not present. Methods of design, testing, and analysis of ultra-reliable software are discussed. It is concluded that a design-for-validation based on formal methods is needed for the digital flight control systems problem, and also that formal methods will play a major role in the development of future high reliability digital systems.

  2. Methodological Imperfection and Formalizations of Scientific Activity

    NASA Astrophysics Data System (ADS)

    Svetlichny, George

    1987-03-01

    Any mathematical formalization of scientific activity allows for imperfections in the methodology that is formalized. These can be of three types, “dirty,” “rotten,” and “dammed.” Restricting mathematical attention to those methods that cannot be construed to be imperfect drastically reduces the class of objects that must be analyzed, and relates all other objects to these more regular ones. Examples are drawn from empirical logic.

  3. Formality of the Chinese collective leadership.

    PubMed

    Li, Haiying; Graesser, Arthur C

    2016-09-01

    We investigated the linguistic patterns in the discourse of four generations of the collective leadership of the Communist Party of China (CPC) from 1921 to 2012. The texts of Mao Zedong, Deng Xiaoping, Jiang Zemin, and Hu Jintao were analyzed using computational linguistic techniques (a Chinese formality score) to explore the persuasive linguistic features of the leaders in the contexts of power phase, the nation's education level, power duration, and age. The study was guided by the elaboration likelihood model of persuasion, which includes a central route (represented by formal discourse) versus a peripheral route (represented by informal discourse) to persuasion. The results revealed that these leaders adopted the formal, central route more when they were in power than before they came into power. The nation's education level was a significant factor in the leaders' adoption of the persuasion strategy. The leaders' formality also decreased with their increasing age and in-power times. However, the predictability of these factors for formality had subtle differences among the different types of leaders. These results enhance our understanding of the Chinese collective leadership and the role of formality in politically persuasive messages. PMID:27406253

  4. Formal verification of an avionics microprocessor

    NASA Technical Reports Server (NTRS)

    Srivas, Mandayam, K.; Miller, Steven P.

    1995-01-01

    Formal specification combined with mechanical verification is a promising approach for achieving the extremely high levels of assurance required of safety-critical digital systems. However, many questions remain regarding their use in practice: Can these techniques scale up to industrial systems, where are they likely to be useful, and how should industry go about incorporating them into practice? This report discusses a project undertaken to answer some of these questions, the formal verification of the AAMPS microprocessor. This project consisted of formally specifying in the PVS language a rockwell proprietary microprocessor at both the instruction-set and register-transfer levels and using the PVS theorem prover to show that the microcode correctly implemented the instruction-level specification for a representative subset of instructions. Notable aspects of this project include the use of a formal specification language by practicing hardware and software engineers, the integration of traditional inspections with formal specifications, and the use of a mechanical theorem prover to verify a portion of a commercial, pipelined microprocessor that was not explicitly designed for formal verification.

  5. (abstract) Formal Inspection Technology Transfer Program

    NASA Technical Reports Server (NTRS)

    Welz, Linda A.; Kelly, John C.

    1993-01-01

    A Formal Inspection Technology Transfer Program, based on the inspection process developed by Michael Fagan at IBM, has been developed at JPL. The goal of this program is to support organizations wishing to use Formal Inspections to improve the quality of software and system level engineering products. The Technology Transfer Program provides start-up materials and assistance to help organizations establish their own Formal Inspection program. The course materials and certified instructors associated with the Technology Transfer Program have proven to be effective in classes taught at other NASA centers as well as at JPL. Formal Inspections (NASA tailored Fagan Inspections) are a set of technical reviews whose objective is to increase quality and reduce the cost of software development by detecting and correcting errors early. A primary feature of inspections is the removal of engineering errors before they amplify into larger and more costly problems downstream in the development process. Note that the word 'inspection' is used differently in software than in a manufacturing context. A Formal Inspection is a front-end quality enhancement technique, rather than a task conducted just prior to product shipment for the purpose of sorting defective systems (manufacturing usage). Formal Inspections are supporting and in agreement with the 'total quality' approach being adopted by many NASA centers.

  6. Time-dependent Landauer—Büttiker formalism for superconducting junctions at arbitrary temperatures

    NASA Astrophysics Data System (ADS)

    Tuovinen, Riku; van Leeuwen, Robert; Perfetto, Enrico; Stefanucci, Gianluca

    2016-03-01

    We discuss an extension of our earlier work on the time-dependent Landauer- Buttiker formalism for noninteracting electronic transport. The formalism can without complication be extended to superconducting central regions since the Green's functions in the Nambu representation satisfy the same equations of motion which, in turn, leads to the same closed expression for the equal-time lesser Green's function, i.e., for the time-dependent reduced one-particle density matrix. We further write the finite-temperature frequency integrals in terms of known special functions thereby considerably speeding up the computation. Simulations in simple normal metal - superconductor - normal metal junctions are also presented.

  7. Fuzzy operators and cyclic behavior in formal neuronal networks

    NASA Technical Reports Server (NTRS)

    Labos, E.; Holden, A. V.; Laczko, J.; Orzo, L.; Labos, A. S.

    1992-01-01

    Formal neuronal networks (FNN), which are comprised of threshold gates, make use of the unit step function. It is regarded as a degenerated distribution function (DDF) and will be referred to here as a non-fuzzy threshold operator (nFTO). Special networks of this kind generating long cycles of states are modified by introduction of fuzzy threshold operators (FTO), i.e., non-degenerated distribution functions (nDDF). The cyclic behavior of the new nets is compared with the original ones. The interconnection matrix and threshold values are not modified. It is concluded that the original long cycles change the fixed points and short cycles, and as the computer simulations demonstrate, the aperiodic motion that is associated with chaotic behavior appears. The emergence of the above changes depend on the steepness of the threshold operators.

  8. Hybrid matrix fiber composites

    DOEpatents

    Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

    2003-07-15

    Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites include two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

  9. Roulettes: a weak lensing formalism for strong lensing: I. Overview

    NASA Astrophysics Data System (ADS)

    Clarkson, Chris

    2016-08-01

    We present a new perspective on gravitational lensing. We describe a new extension of the weak lensing formalism capable of describing strongly lensed images. By integrating the nonlinear geodesic deviation equation, the amplification matrix of weak lensing is generalised to a sum over independent amplification tensors of increasing rank. We show how an image distorted by a generic lens may be constructed as a sum over ‘roulettes’, which are the natural curves associated with the independent spin modes of the amplification tensors. Highly distorted images can be constructed even for large sources observed near or within the Einstein radius of a lens where the shear and convergence are large. The amplitude of each roulette is formed from a sum over appropriate derivatives of the lensing potential. Consequently, measuring these individual roulettes for images around a lens gives a new way to reconstruct a strong lens mass distribution without requiring a lens model. This formalism generalises the convergence, shear and flexion of weak lensing to arbitrary order, and provides a unified bridge between the strong and weak lensing regimes. This overview paper is accompanied by a much more detailed paper II, arXiv:1603.04652.

  10. Formal Methods Case Studies for DO-333

    NASA Technical Reports Server (NTRS)

    Cofer, Darren; Miller, Steven P.

    2014-01-01

    RTCA DO-333, Formal Methods Supplement to DO-178C and DO-278A provides guidance for software developers wishing to use formal methods in the certification of airborne systems and air traffic management systems. The supplement identifies the modifications and additions to DO-178C and DO-278A objectives, activities, and software life cycle data that should be addressed when formal methods are used as part of the software development process. This report presents three case studies describing the use of different classes of formal methods to satisfy certification objectives for a common avionics example - a dual-channel Flight Guidance System. The three case studies illustrate the use of theorem proving, model checking, and abstract interpretation. The material presented is not intended to represent a complete certification effort. Rather, the purpose is to illustrate how formal methods can be used in a realistic avionics software development project, with a focus on the evidence produced that could be used to satisfy the verification objectives found in Section 6 of DO-178C.

  11. Formal methods for Hopfield-like networks.

    PubMed

    Ben Amor, Hedi; Corblin, Fabien; Fanchon, Eric; Elena, Adrien; Trilling, Laurent; Demongeot, Jacques; Glade, Nicolas

    2013-03-01

    Building a meaningful model of biological regulatory network is usually done by specifying the components (e.g. the genes) and their interactions, by guessing the values of parameters, by comparing the predicted behaviors to the observed ones, and by modifying in a trial-error process both architecture and parameters in order to reach an optimal fitness. We propose here a different approach to construct and analyze biological models avoiding the trial-error part, where structure and dynamics are represented as formal constraints. We apply the method to Hopfield-like networks, a formalism often used in both neural and regulatory networks modeling. The aim is to characterize automatically the set of all models consistent with all the available knowledge (about structure and behavior). The available knowledge is formalized into formal constraints. The latter are compiled into Boolean formula in conjunctive normal form and then submitted to a Boolean satisfiability solver. This approach allows to formulate a wide range of queries, expressed in a high level language, and possibly integrating formalized intuitions. In order to explore its potential, we use it to find cycles for 3-nodes networks and to determine the flower morphogenesis regulatory network of Arabidopsis thaliana. Applications of this technique are numerous and concern the building of models from data as well as the design of biological networks possessing specified behaviors. PMID:23381497

  12. Towards Formal Verification of a Separation Microkernel

    NASA Astrophysics Data System (ADS)

    Butterfield, Andrew; Sanan, David; Hinchey, Mike

    2013-08-01

    The best approach to verifying an IMA separation kernel is to use a (fixed) time-space partitioning kernel with a multiple independent levels of separation (MILS) architecture. We describe an activity that explores the cost and feasibility of doing a formal verification of such a kernel to the Common Criteria (CC) levels mandated by the Separation Kernel Protection Profile (SKPP). We are developing a Reference Specification of such a kernel, and are using higher-order logic (HOL) to construct formal models of this specification and key separation properties. We then plan to do a dry run of part of a formal proof of those properties using the Isabelle/HOL theorem prover.

  13. First order formalism for quantum gravity

    SciTech Connect

    Gleiser, M.; Holman, R.; Neto, N.P.

    1987-05-01

    We develop a first order formalism for the quantization of gravity. We take as canonical variables both the induced metric and the extrinsic curvature of the (d - 1) -dimensional hypersurfaces obtained by the foliation of the d - dimensional spacetime. After solving the constraint algebra we use the Dirac formalism to quantize the theory and obtain a new representation for the Wheeler-DeWitt equation, defined in the functional space of the extrinsic curvature. We also show how to obtain several different representations of the Wheeler-DeWitt equation by considering actions differing by a total divergence. In particular, the intrinsic and extrinsic time approaches appear in a natural way, as do equivalent representations obtained by functional Fourier transforms of appropriate variables. We conclude with some remarks about the construction of the Hilbert space within the first order formalism. 10 refs.

  14. Formalizing Darwinism and inclusive fitness theory.

    PubMed

    Grafen, Alan

    2009-11-12

    Inclusive fitness maximization is a basic building block for biological contributions to any theory of the evolution of society. There is a view in mathematical population genetics that nothing is caused to be maximized in the process of natural selection, but this is explained as arising from a misunderstanding about the meaning of fitness maximization. Current theoretical work on inclusive fitness is discussed, with emphasis on the author's 'formal Darwinism project'. Generally, favourable conclusions are drawn about the validity of assuming fitness maximization, but the need for continuing work is emphasized, along with the possibility that substantive exceptions may be uncovered. The formal Darwinism project aims more ambitiously to represent in a formal mathematical framework the central point of Darwin's Origin of Species, that the mechanical processes of inheritance and reproduction can give rise to the appearance of design, and it is a fitting ambition in Darwin's bicentenary year to capture his most profound discovery in the lingua franca of science. PMID:19805422

  15. MOOC & B-Learning: Students' Barriers and Satisfaction in Formal and Non-Formal Learning Environments

    ERIC Educational Resources Information Center

    Gutiérrez-Santiuste, Elba; Gámiz-Sánchez, Vanesa-M.; Gutiérrez-Pérez, Jose

    2015-01-01

    The study presents a comparative analysis of two virtual learning formats: one non-formal through a Massive Open Online Course (MOOC) and the other formal through b-learning. We compare the communication barriers and the satisfaction perceived by the students (N = 249) by developing a qualitative analysis using semi-structured questionnaires and…

  16. Formal and Non-Formal Digital Practices: Institutionalizing Transactional Learning Spaces in a Media Classroom

    ERIC Educational Resources Information Center

    de Lange, Thomas

    2011-01-01

    This article examines how a classroom procedure known as PGE (Plan/Go-through/Evaluate) group work aims at integrating formal and non-formal media experiences and practices into classroom-based media learning. The study displays, on the one hand, how PGE group work emerged and was institutionally embedded in a media course. On the other hand, the…

  17. Combining Formal, Non-Formal and Informal Learning for Workforce Skill Development

    ERIC Educational Resources Information Center

    Misko, Josie

    2008-01-01

    This literature review, undertaken for Australian Industry Group, shows how multiple variations and combinations of formal, informal and non-formal learning, accompanied by various government incentives and organisational initiatives (including job redesign, cross-skilling, multi-skilling, diversified career pathways, action learning projects,…

  18. The Interrelatedness of Formal, Non-Formal and Informal Learning: Evidence from Labour Market Program Participants

    ERIC Educational Resources Information Center

    Cameron, Roslyn; Harrison, Jennifer L.

    2012-01-01

    Definitions, differences and relationships between formal, non-formal and informal learning have long been contentious. There has been a significant change in language and reference from adult education to what amounts to forms of learning categorised by their modes of facilitation. Nonetheless, there is currently a renewed interest in the…

  19. The Comparative Functionality of Formal and Non-Formal Education for Women: Final Report.

    ERIC Educational Resources Information Center

    Derryck, Vivian Lowery

    This final report describes a five-phase study to ascertain whether formal or non-formal education has the greater functionality to accelerate women's integration into development activities. Part 1 (two chapters), introduction and background, defines the problem, sets parameters of the study, and provides definitions of education terms. Part 2…

  20. Educación no formal

    NASA Astrophysics Data System (ADS)

    Tignanelli, H.

    Se comentan en esta comunicación, las principales contribuciones realizadas en el campo de la educación en astronomía en los niveles primario, secundario y terciario, como punto de partida para la discusión de la actual inserción de los contenidos astronómicos en los nuevos contenidos curriculares de la EGB - Educación General Básica- y Polimodal, de la Reforma Educativa. En particular, se discuten los alcances de la educación formal y no formal, su importancia para la capacitación de profesores y maestros, y perspectivas a futuro.

  1. Keldysh formalism for multiple parallel worlds

    NASA Astrophysics Data System (ADS)

    Ansari, M.; Nazarov, Y. V.

    2016-03-01

    We present a compact and self-contained review of the recently developed Keldysh formalism for multiple parallel worlds. The formalism has been applied to consistent quantum evaluation of the flows of informational quantities, in particular, to the evaluation of Renyi and Shannon entropy flows. We start with the formulation of the standard and extended Keldysh techniques in a single world in a form convenient for our presentation. We explain the use of Keldysh contours encompassing multiple parallel worlds. In the end, we briefly summarize the concrete results obtained with the method.

  2. Extending the ADM formalism to Weyl geometry

    SciTech Connect

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-26

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  3. Density matrix embedding theory for interacting electron-phonon systems

    NASA Astrophysics Data System (ADS)

    Sandhoefer, Barbara; Chan, Garnet Kin-Lic

    2016-08-01

    We describe the extension of the density matrix embedding theory framework to coupled interacting fermion-boson systems. This provides a frequency-independent, entanglement embedding formalism to treat bulk fermion-boson problems. We illustrate the concepts within the context of the one-dimensional Hubbard-Holstein model, where the phonon bath states are obtained from the Schmidt decomposition of a self-consistently adjusted coherent state. We benchmark our results against accurate density matrix renormalization group calculations.

  4. Pauli theorem in the description of n-dimensional spinors in the Clifford algebra formalism

    NASA Astrophysics Data System (ADS)

    Shirokov, D. S.

    2013-04-01

    We discuss a generalized Pauli theorem and its possible applications for describing n-dimensional (Dirac, Weyl, Majorana, and Majorana-Weyl) spinors in the Clifford algebra formalism. We give the explicit form of elements that realize generalizations of Dirac, charge, and Majorana conjugations in the case of arbitrary space dimensions and signatures, using the notion of the Clifford algebra additional signature to describe conjugations. We show that the additional signature can take only certain values despite its dependence on the matrix representation

  5. Formal Synthesis of (±)-Roseophilin

    PubMed Central

    Bitar, Abdallah Y.; Frontier, Alison J.

    2009-01-01

    A formal synthesis of (±)-roseophilin is described. Scandium(III)-catalyzed Nazarov cyclization of 2,5-disubstituted N-tosylpyrrole 19 gives a 5,5’-fused ketopyrrole, and ansa-bridge formation via π-allyl palladium macrocyclization gives 21. PMID:19053717

  6. A Simplified Approach to Product Operator Formalism

    ERIC Educational Resources Information Center

    Spiese, Christopher E.

    2004-01-01

    The utilization of the simple and traditional vector model-based product operator formalism is highlighted. It is seen as a critical device in the area of nuclear magnetic resonance (NMR) spectrometry for a comprehensive analysis of spin coupling and quantum coherences.

  7. Formal Method of Description Supporting Portfolio Assessment

    ERIC Educational Resources Information Center

    Morimoto, Yasuhiko; Ueno, Maomi; Kikukawa, Isao; Yokoyama, Setsuo; Miyadera, Youzou

    2006-01-01

    Teachers need to assess learner portfolios in the field of education. However, they need support in the process of designing and practicing what kind of portfolios are to be assessed. To solve the problem, a formal method of describing the relations between the lesson forms and portfolios that need to be collected and the relations between…

  8. Connecting Formal and Informal Learning Experiences

    ERIC Educational Resources Information Center

    O'Mahony, Timothy Kieran

    2010-01-01

    The learning study reports on part of a larger project being lead by the author. In this dissertation I explore one goal of this project--to understand effects on student learning outcomes as a function of using different methods for connecting out-of-school experiential learning with formal school-based instruction. There is a long history of…

  9. The Transition to Formal Thinking in Mathematics

    ERIC Educational Resources Information Center

    Tall, David

    2008-01-01

    This paper focuses on the changes in thinking involved in the transition from school mathematics to formal proof in pure mathematics at university. School mathematics is seen as a combination of visual representations, including geometry and graphs, together with symbolic calculations and manipulations. Pure mathematics in university shifts…

  10. Preparing for Formal Proofs in Geometry

    ERIC Educational Resources Information Center

    Johnson, Art

    2009-01-01

    One way in which geometry teachers can help students develop their reasoning is by providing proof-readiness experiences. Blum and Kirsch (1991) suggest that "preformal proofs" can help students develop deductive reasoning. Preformal proofs, which follow the basic principles of deductive reasoning, can help prepare students for formal deduction in…

  11. 28 CFR 68.39 - Formal hearings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Formal hearings. 68.39 Section 68.39 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) RULES OF PRACTICE AND PROCEDURE FOR ADMINISTRATIVE HEARINGS BEFORE ADMINISTRATIVE LAW JUDGES IN CASES INVOLVING ALLEGATIONS OF UNLAWFUL EMPLOYMENT OF ALIENS, UNFAIR IMMIGRATION-RELATED...

  12. Hearing-Impaired Formal Inservice Program.

    ERIC Educational Resources Information Center

    Northeast Regional Media Center for the Deaf, Amherst, MA.

    The HI-FI (Hearing-Impaired Formal Inservice) Program is described as a set of inservice materials targeted for workshops of regular classroom teachers and other school personnel concerned with school district and classroom management of hearing impaired (HI) children. An introductory section focuses on the design of the program materials,…

  13. An Elementary Formalism for General Relativity.

    ERIC Educational Resources Information Center

    diSessa, Andrea A.

    1981-01-01

    An elementary formalism is developed for representing curved space-time which allows transparent qualitative explanation of general relativistic effects and is used to make a conceptual analysis of Einstein's principle of equivalence. A final section outlines a number of student activities. (Author/SK)

  14. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... established in accordance with 50 CFR 13.45 and 18.27 for FWS and 50 CFR 220.45 and 228.5 for NMFS. (4)...

  15. Conservation-dissipation formalism of irreversible thermodynamics

    NASA Astrophysics Data System (ADS)

    Zhu, Yi; Hong, Liu; Yang, Zaibao; Yong, Wen-An

    2015-06-01

    We propose a conservation-dissipation formalism (CDF) for coarse-grained descriptions of irreversible processes. This formalism is based on a stability criterion for non-equilibrium thermodynamics. The criterion ensures that non-equilibrium states tend to equilibrium in long time. As a systematic methodology, CDF provides a feasible procedure in choosing non-equilibrium state variables and determining their evolution equations. The equations derived in CDF have a unified elegant form. They are globally hyperbolic, allow a convenient definition of weak solutions, and are amenable to existing numerics. More importantly, CDF is a genuinely nonlinear formalism and works for systems far away from equilibrium. With this formalism, we formulate novel thermodynamics theories for heat conduction in rigid bodies and non-isothermal compressible Maxwell fluid flows as two typical examples. In these examples, the non-equilibrium variables are exactly the conjugate variables of the heat fluxes or stress tensors. The new theory generalizes Cattaneo's law or Maxwell's law in a regularized and nonlinear fashion.

  16. 14 CFR 302.20 - Formal intervention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Formal intervention. 302.20 Section 302.20 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) PROCEDURAL REGULATIONS RULES OF PRACTICE IN PROCEEDINGS Rules of General Applicability Oral Evidentiary Hearing Proceedings § 302.20...

  17. 14 CFR 13.5 - Formal complaints.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Formal complaints. 13.5 Section 13.5... Aviation Administration, Office of the Chief Counsel, Attention: Enforcement Docket (AGC-10), 800... of the complaint are maintained in current docket form in the Enforcement Docket (AGC-10), Office...

  18. Quantum formalism to describe binocular rivalry.

    PubMed

    Manousakis, Efstratios

    2009-11-01

    On the basis of the general character and operation of the process of perception, a formalism is sought to mathematically describe the subjective or abstract/mental process of perception. It is shown that the formalism of orthodox quantum theory of measurement, where the observer plays a key role, is a broader mathematical foundation which can be adopted to describe the dynamics of the subjective experience. The mathematical formalism describes the psychophysical dynamics of the subjective or cognitive experience as communicated to us by the subject. Subsequently, the formalism is used to describe simple perception processes and, in particular, to describe the probability distribution of dominance duration obtained from the testimony of subjects experiencing binocular rivalry. Using this theory and parameters based on known values of neuronal oscillation frequencies and firing rates, the calculated probability distribution of dominance duration of rival states in binocular rivalry under various conditions is found to be in good agreement with available experimental data. This theory naturally explains an observed marked increase in dominance duration in binocular rivalry upon periodic interruption of stimulus and yields testable predictions for the distribution of perceptual alteration in time. PMID:19520143

  19. Leadership and Exchange in Formal Organizations.

    ERIC Educational Resources Information Center

    Jacobs, T. O.

    This volume reviews and reinterprets the existing literature on leadership, power, and influence processes; and provides a theoretical basis for understanding the leadership process in formal organizations. Numerous cited studies demonstrate that leadership is always relative to the situation; e.g., the effective leader makes a significant…

  20. Formal Schema Theory and Teaching EFL Reading

    ERIC Educational Resources Information Center

    Young, Barbara N; Man, Zhou

    2005-01-01

    Inquirers designed and conducted a study investigating whether or not results derived from previous research focusing on teaching and learning English as a native or foreign language would be replicated in a learning environment in which English is taught as a foreign language as in China. Because activation of formal schemata plays an important…

  1. Formal and Applied Counseling in Israel

    ERIC Educational Resources Information Center

    Israelashvili, Moshe; Wegman-Rozi, Orit

    2012-01-01

    Living in Israel is intensive and demanding but also meaningful and exciting. This article addresses the gap between the narrowly defined formal status of counseling in Israel and the widespread occurrence of counseling in various settings. It is argued that several recent changes, especially in the definition of treatment, along with the…

  2. Identifying Concrete and Formal Operational Children.

    ERIC Educational Resources Information Center

    Docherty, Edward M.

    This paper presents a study designed to determine if groups of concrete and formal operational children can be identified through the technique of cluster analysis, using a battery of Piagetian tasks. A Total of 64 subjects, 8 boys and 8 girls from each of the second, fourth, sixth, and eighth grade levels, were selected from a public elementary…

  3. Partial Derivative Automata Formalized in Coq

    NASA Astrophysics Data System (ADS)

    Almeida, José Bacelar; Moreira, Nelma; Pereira, David; de Sousa, Simão Melo

    In this paper we present a computer assisted proof of the correctness of a partial derivative automata construction from a regular expression within the Coq proof assistant. This proof is part of a formalization of Kleene algebra and regular languages in Coq towards their usage in program certification.

  4. External sources in field-antifield formalism

    NASA Astrophysics Data System (ADS)

    Batalin, Igor A.; Bering, Klaus

    2014-04-01

    We introduce external sources JA directly into the quantum master action W of the field-antifield formalism instead of the effective action. The external sources JA lead to a set of BRST-invariant functions WA that are in antisymplectic involution. As a byproduct, we encounter quasi-groups with open gauge algebras.

  5. Teaching Some Informatics Concepts Using Formal System

    ERIC Educational Resources Information Center

    Yang, Sojung; Park, Seongbin

    2014-01-01

    There are many important issues in informatics and many agree that algorithms and programming are most important issues that need to be included in informatics education (Dagiene and Jevsikova, 2012). In this paper, we propose how some of these issues can be easily taught using the notion of a formal system which consists of axioms and inference…

  6. Formal Foundations for Hierarchical Safety Cases

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Pai, Ganesh; Whiteside, Iain

    2015-01-01

    Safety cases are increasingly being required in many safety-critical domains to assure, using structured argumentation and evidence, that a system is acceptably safe. However, comprehensive system-wide safety arguments present appreciable challenges to develop, understand, evaluate, and manage, partly due to the volume of information that they aggregate, such as the results of hazard analysis, requirements analysis, testing, formal verification, and other engineering activities. Previously, we have proposed hierarchical safety cases, hicases, to aid the comprehension of safety case argument structures. In this paper, we build on a formal notion of safety case to formalise the use of hierarchy as a structuring technique, and show that hicases satisfy several desirable properties. Our aim is to provide a formal, theoretical foundation for safety cases. In particular, we believe that tools for high assurance systems should be granted similar assurance to the systems to which they are applied. To this end, we formally specify and prove the correctness of key operations for constructing and managing hicases, which gives the specification for implementing hicases in AdvoCATE, our toolset for safety case automation. We motivate and explain the theory with the help of a simple running example, extracted from a real safety case and developed using AdvoCATE.

  7. Aspects of Financing Non-Formal Education.

    ERIC Educational Resources Information Center

    Morales, Francisco X. Swett

    1983-01-01

    Various financing structures for nonformal education are presented, using examples from Colombia, Brazil, Costa Rica, and Ecuador. Many resources of the formal education system can be used in the planning, coordination, and execution of nonformal education. The importance of community involvement and financial backing is stressed. (JA)

  8. 14 CFR 201.1 - Formal requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Formal requirements. 201.1 Section 201.1 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIR CARRIER AUTHORITY UNDER SUBTITLE VII OF TITLE 49 OF THE UNITED STATES CODE-...

  9. 14 CFR 201.1 - Formal requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Formal requirements. 201.1 Section 201.1 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIR CARRIER AUTHORITY UNDER SUBTITLE VII OF TITLE 49 OF THE UNITED STATES CODE-...

  10. 14 CFR 201.1 - Formal requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Formal requirements. 201.1 Section 201.1 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIR CARRIER AUTHORITY UNDER SUBTITLE VII OF TITLE 49 OF THE UNITED STATES CODE-...

  11. 14 CFR 201.1 - Formal requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Formal requirements. 201.1 Section 201.1 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIR CARRIER AUTHORITY UNDER SUBTITLE VII OF TITLE 49 OF THE UNITED STATES CODE-...

  12. 14 CFR 201.1 - Formal requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Formal requirements. 201.1 Section 201.1 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIR CARRIER AUTHORITY UNDER SUBTITLE VII OF TITLE 49 OF THE UNITED STATES CODE-...

  13. HIV Education in the Formal Curriculum

    ERIC Educational Resources Information Center

    Nsubuga, Yusuf K.; Bonnet, Sandrine

    2009-01-01

    The AIDS epidemic presents a complex of issues that require global answers, involving entire societies. The only sustainable solution is to include all sectors of society in a multidisciplinary collaboration, within which the formal education system plays a key role in delivering a comprehensive response to the disease at the national level.…

  14. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Formal consultation. 402.14 Section 402.14 Wildlife and Fisheries JOINT REGULATIONS (UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR AND NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE); ENDANGERED...

  15. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... established in accordance with 50 CFR 13.45 and 18.27 for FWS and 50 CFR 220.45 and 228.5 for NMFS. (4)...

  16. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... established in accordance with 50 CFR 13.45 and 18.27 for FWS and 50 CFR 220.45 and 228.5 for NMFS. (4)...

  17. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... established in accordance with 50 CFR 13.45 and 18.27 for FWS and 50 CFR 220.45 and 228.5 for NMFS. (4)...

  18. 14 CFR 13.5 - Formal complaints.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INVESTIGATIVE AND ENFORCEMENT PROCEDURES Investigative Procedures § 13.5 Formal complaints. (a) Any person may... purpose of seeking an appropriate order or other enforcement action; (2) Be submitted to the Federal... performance of official duties shall be referred to the Secretary of the Department concerned for action...

  19. Gravitational Compton Scattering from the Worldline Formalism

    NASA Astrophysics Data System (ADS)

    Ahmadiniaz, Naser; Corradini, Olindo; Dávila, José Manuel; Schubert, Christian

    2016-07-01

    We report on an ongoing study of photon amplitudes, graviton amplitudes and mixed photon-graviton amplitudes at tree-level using the worldline formalism. We explicitly recalculate the amplitude with one photon and one graviton coupled to a scalar propagator, relevant for graviton photoproduction. We comment on the factorization properties of this amplitude, and outline a generalization to similar processes involving more gravitons.

  20. Safety in Children's Formal Play Environments.

    ERIC Educational Resources Information Center

    Wilkinson, Paul F.; Lockhart, Robert

    This study was designed to examine the issue of the safety of children's formal play environments. Safety was defined in terms of morbidity and mortality data. Protection and safety education were considered the prime factors in accident prevention while the goal of a safety program was considered to be the minimizing of injuries. Several data…

  1. Informal Science Learning in the Formal Classroom

    ERIC Educational Resources Information Center

    Walsh, Lori; Straits, William

    2014-01-01

    In this article the authors share advice from the viewpoints of both a formal and informal educator that will help teachers identify the right Informal Science Institutions (ISIs)--institutions that specialize in learning that occurs outside of the school setting--to maximize their students' learning and use informal education to their…

  2. Helping Students Understand Formal Chemical Concepts.

    ERIC Educational Resources Information Center

    Ward, Charles R.; Herron, J. Dudley

    1980-01-01

    Investigated outcomes of the use of the learning cycle, which divides instruction into the Piagetian phases of exploration, invention, and discovery in general college chemistry laboratory experiments. Differences between concrete and formal operational students were explored in students' ability to master chemistry material varying in cognitive…

  3. Formalism and the notion of truth

    NASA Astrophysics Data System (ADS)

    Spencer, Joseph M.

    The most widely acknowledged conceptions of truth take some kind of relation to be at truth's core. This dissertation attempts to establish that an adequate conception of this relation begins with an investigation of the entanglement of the formal and the material as set forth in the model theoretical development of set theoretical mathematics. Truth concerns first and most crucially a certain commerce across the border between the formal and the material, between the ideal and the real. The entanglement of the formal and the material must be thought in itself, apart from or prior to any assimilation into philosophical schemas committed to larger metaphysical claims. This is accomplished in model theory. The twentieth century witnessed two attempts at bringing model theoretical mathematics to bear on accounting philosophically for the concept of truth: that of Alfred Tarski, and that of Alain Badiou. In order to investigate the relevance of model theory to the task of working out a philosophical conception of truth, this dissertation investigates, through comparative work, these two thinkers. It is necessary to see where their projects converge in important ways, as well as where their projects diverge in equally important ways. What brings their work into close proximity is their shared conviction that truth must be thought in light of model theory. Nonetheless, the two do not agree about exactly how model theory sheds light on truth. Comparative study thus reveals both a shared site for thinking and a struggle over the significance of that site. Agreement between Tarski and Badiou concerns the excess of the purely formal over itself, marked by the generation of an undecidable statement within formal systems of a certain level of complexity. Both thinkers determine that this formal excess touches on the material, and both further determine that the consequent entanglement of the formal and the material provides the basic frame for any philosophical consideration

  4. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  5. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  6. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  7. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  8. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits EMPLOYMENT STANDARDS ADMINISTRATION, DEPARTMENT OF LABOR LONGSHOREMEN'S... Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings are...

  9. Formally verifying Ada programs which use real number types

    NASA Technical Reports Server (NTRS)

    Sutherland, David

    1986-01-01

    Formal verification is applied to programs which use real number arithmetic operations (mathematical programs). Formal verification of a program P consists of creating a mathematical model of F, stating the desired properties of P in a formal logical language, and proving that the mathematical model has the desired properties using a formal proof calculus. The development and verification of the mathematical model are discussed.

  10. 20 CFR 702.336 - Formal hearings; new issues.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Formal hearings; new issues. 702.336 Section... Procedures Formal Hearings § 702.336 Formal hearings; new issues. (a) If, during the course of the formal hearing, the evidence presented warrants consideration of an issue or issues not previously...

  11. 5 CFR 2638.309 - Reliance on formal advisory opinions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Reliance on formal advisory opinions... OF GOVERNMENT ETHICS AND EXECUTIVE AGENCY ETHICS PROGRAM RESPONSIBILITIES Formal Advisory Opinion Service § 2638.309 Reliance on formal advisory opinions. (a) Any formal advisory opinion referred to...

  12. 5 CFR 2638.309 - Reliance on formal advisory opinions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Reliance on formal advisory opinions... OF GOVERNMENT ETHICS AND EXECUTIVE AGENCY ETHICS PROGRAM RESPONSIBILITIES Formal Advisory Opinion Service § 2638.309 Reliance on formal advisory opinions. (a) Any formal advisory opinion referred to...

  13. 5 CFR 2638.309 - Reliance on formal advisory opinions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Reliance on formal advisory opinions... OF GOVERNMENT ETHICS AND EXECUTIVE AGENCY ETHICS PROGRAM RESPONSIBILITIES Formal Advisory Opinion Service § 2638.309 Reliance on formal advisory opinions. (a) Any formal advisory opinion referred to...

  14. Formal methods demonstration project for space applications

    NASA Technical Reports Server (NTRS)

    Divito, Ben L.

    1995-01-01

    The Space Shuttle program is cooperating in a pilot project to apply formal methods to live requirements analysis activities. As one of the larger ongoing shuttle Change Requests (CR's), the Global Positioning System (GPS) CR involves a significant upgrade to the Shuttle's navigation capability. Shuttles are to be outfitted with GPS receivers and the primary avionics software will be enhanced to accept GPS-provided positions and integrate them into navigation calculations. Prior to implementing the CR, requirements analysts at Loral Space Information Systems, the Shuttle software contractor, must scrutinize the CR to identify and resolve any requirements issues. We describe an ongoing task of the Formal Methods Demonstration Project for Space Applications whose goal is to find an effective way to use formal methods in the GPS CR requirements analysis phase. This phase is currently under way and a small team from NASA Langley, ViGYAN Inc. and Loral is now engaged in this task. Background on the GPS CR is provided and an overview of the hardware/software architecture is presented. We outline the approach being taken to formalize the requirements, only a subset of which is being attempted. The approach features the use of the PVS specification language to model 'principal functions', which are major units of Shuttle software. Conventional state machine techniques form the basis of our approach. Given this background, we present interim results based on a snapshot of work in progress. Samples of requirements specifications rendered in PVS are offered to illustration. We walk through a specification sketch for the principal function known as GPS Receiver State processing. Results to date are summarized and feedback from Loral requirements analysts is highlighted. Preliminary data is shown comparing issues detected by the formal methods team versus those detected using existing requirements analysis methods. We conclude by discussing our plan to complete the remaining

  15. Formal concept analysis and linguistic hedges

    NASA Astrophysics Data System (ADS)

    Belohlavek, Radim; Vychodil, Vilem

    2012-07-01

    This paper presents an application of linguistic hedges to formal concept analysis of data with fuzzy attributes. Formal concept analysis aims at extraction of particular (bi-)clusters, called formal concepts, from data. The clusters link collections of objects (extents) and attributes (intents), and have a clear interpretation due to a simple verbal description of the concept-forming operators. We insert linguistic hedges such as 'very' or 'extremely' in the description of the operators. In this way, linguistic hedges become parameters for formal concept analysis that control the number of clusters extracted from data. Namely, as we show theoretically as well as experimentally, stronger hedges result in a smaller number of clusters. The new concept-forming operators form Galois-like connections. We study their properties and axiomatize them. Then, we show that a concept lattice with hedges, i.e. the set of all formal concepts of the new operators is indeed a complete lattice which is isomorphic to a particular ordinary concept lattice. We describe the isomorphism and its inverse. These mappings serve as translation procedures. As a consequence, we obtain a theorem characterizing the structure of concept lattices with hedges which generalizes the well-known main theorem of ordinary concept lattices. The isomorphism and its inverse enable us to compute a concept lattice with hedges using algorithms for ordinary concept lattices. We demonstrate by experiments that when selecting various hedges from the strongest to weaker hedges, the reduction in size of the corresponding concept lattices is smooth. From a broader perspective, we argue that linguistic hedges represent mathematically and computationally a feasible way to parameterize methods for knowledge extraction from data that enable one to emphasize or to suppress extracted patterns while keeping their interpretation.

  16. A matrix lower bound

    SciTech Connect

    Grcar, Joseph F.

    2002-02-04

    A matrix lower bound is defined that generalizes ideas apparently due to S. Banach and J. von Neumann. The matrix lower bound has a natural interpretation in functional analysis, and it satisfies many of the properties that von Neumann stated for it in a restricted case. Applications for the matrix lower bound are demonstrated in several areas. In linear algebra, the matrix lower bound of a full rank matrix equals the distance to the set of rank-deficient matrices. In numerical analysis, the ratio of the matrix norm to the matrix lower bound is a condition number for all consistent systems of linear equations. In optimization theory, the matrix lower bound suggests an identity for a class of min-max problems. In real analysis, a recursive construction that depends on the matrix lower bound shows that the level sets of continuously differential functions lie asymptotically near those of their tangents.

  17. Nonequilibrium problems in quantum field theory and Schwinger`s closed time path formalism

    SciTech Connect

    Cooper, F.

    1995-05-01

    We review the closed time path formalism of Schwinger using a path integral approach. We apply this formalism to the study of pair production from strong external fields as well as the time evolution of a nonequilibrium chiral phase transition. In 1961 in his classic paper ``Brownian Motion of a Quantum Particle,`` Schwinger solved the formidable technical problem of how to use the action principle to study initial value problems. Previously, the action principle was formulated to study only transition matrix elements from an earlier time to a later time. The elegant solution of this problem was the invention of the closed time path (CTP) formalism. This formalism was first used to study field theory problems by Mahanthappa and Bakshi. With the advent of supercomputers, it has now become possible to use this formalism to numerically solve important field theory questions which are presented as initial value problems. Two of these problems we shall review here. They are (1) The time evolution of the quark- gluon plasma. (2) Dynamical evolution of a non-equilibrium chiral phase transition following a relativistic heavy ion collision.

  18. Formal Safety Certification of Aerospace Software

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Fischer, Bernd

    2005-01-01

    In principle, formal methods offer many advantages for aerospace software development: they can help to achieve ultra-high reliability, and they can be used to provide evidence of the reliability claims which can then be subjected to external scrutiny. However, despite years of research and many advances in the underlying formalisms of specification, semantics, and logic, formal methods are not much used in practice. In our opinion this is related to three major shortcomings. First, the application of formal methods is still expensive because they are labor- and knowledge-intensive. Second, they are difficult to scale up to complex systems because they are based on deep mathematical insights about the behavior of the systems (t.e., they rely on the "heroic proof"). Third, the proofs can be difficult to interpret, and typically stand in isolation from the original code. In this paper, we describe a tool for formally demonstrating safety-relevant aspects of aerospace software, which largely circumvents these problems. We focus on safely properties because it has been observed that safety violations such as out-of-bounds memory accesses or use of uninitialized variables constitute the majority of the errors found in the aerospace domain. In our approach, safety means that the program will not violate a set of rules that can range for the simple memory access rules to high-level flight rules. These different safety properties are formalized as different safety policies in Hoare logic, which are then used by a verification condition generator along with the code and logical annotations in order to derive formal safety conditions; these are then proven using an automated theorem prover. Our certification system is currently integrated into a model-based code generation toolset that generates the annotations together with the code. However, this automated formal certification technology is not exclusively constrained to our code generator and could, in principle, also be

  19. Non-Formal Education: The Definitional Problem. Program of Studies in Non-Formal Education Discussion Papers Number 2.

    ERIC Educational Resources Information Center

    Kleis, Russell J.; And Others

    The three essays in this discussion paper present ways of structuring the concept of non-formal education. "Toward a Contextual Definition of Non-Formal Education" isolates three primary sub-systems: organizational, human, and curricular. Within these subsets non-formal education is differentiated from formal education by a more loosely integrated…

  20. A Screening Matrix for an Initial Line of Inquiry

    ERIC Educational Resources Information Center

    Nordness, Philip D.; Swain, Kristine D.; Haverkost, Ann

    2012-01-01

    The Screening for Understanding: Initial Line of Inquiry was designed to be used in conjunction with the child study team planning process for dealing with continuous problem behaviors prior to conducting a formal functional behavioral assessment. To conduct the initial line of inquiry a one-page reproducible screening matrix was used during child…

  1. Line Mixing in Parallel and Perpendicular Bands of CO2: A Further Test of the Refined Robert-Bonamy Formalism

    NASA Technical Reports Server (NTRS)

    Boulet, C.; Ma, Qiancheng; Tipping, R. H.

    2015-01-01

    Starting from the refined Robert-Bonamy formalism [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013)], we propose here an extension of line mixing studies to infrared absorptions of linear polyatomic molecules having stretching and bending modes. The present formalism does not neglect the internal degrees of freedom of the perturbing molecules, contrary to the energy corrected sudden (ECS) modeling, and enables one to calculate the whole relaxation matrix starting from the potential energy surface. Meanwhile, similar to the ECS modeling, the present formalism properly accounts for roles played by all the internal angular momenta in the coupling process, including the vibrational angular momentum. The formalism has been applied to the important case of CO2 broadened by N2. Applications to two kinds of vibrational bands (sigma yields sigma and sigma yields pi) have shown that the present results are in good agreement with both experimental data and results derived from the ECS model.

  2. Line mixing in parallel and perpendicular bands of CO2: A further test of the refined Robert-Bonamy formalism.

    PubMed

    Boulet, C; Ma, Q; Tipping, R H

    2015-09-28

    Starting from the refined Robert-Bonamy formalism [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013)], we propose here an extension of line mixing studies to infrared absorptions of linear polyatomic molecules having stretching and bending modes. The present formalism does not neglect the internal degrees of freedom of the perturbing molecules, contrary to the energy corrected sudden (ECS) modelling, and enables one to calculate the whole relaxation matrix starting from the potential energy surface. Meanwhile, similar to the ECS modelling, the present formalism properly accounts for roles played by all the internal angular momenta in the coupling process, including the vibrational angular momentum. The formalism has been applied to the important case of CO2 broadened by N2. Applications to two kinds of vibrational bands (Σ → Σ and Σ → Π) have shown that the present results are in good agreement with both experimental data and results derived from the ECS model. PMID:26429017

  3. Generalizing Prototype Theory: A Formal Quantum Framework.

    PubMed

    Aerts, Diederik; Broekaert, Jan; Gabora, Liane; Sozzo, Sandro

    2016-01-01

    Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper. PMID:27065436

  4. Stochastic Formal Correctness of Numerical Algorithms

    NASA Technical Reports Server (NTRS)

    Daumas, Marc; Lester, David; Martin-Dorel, Erik; Truffert, Annick

    2009-01-01

    We provide a framework to bound the probability that accumulated errors were never above a given threshold on numerical algorithms. Such algorithms are used for example in aircraft and nuclear power plants. This report contains simple formulas based on Levy's and Markov's inequalities and it presents a formal theory of random variables with a special focus on producing concrete results. We selected four very common applications that fit in our framework and cover the common practices of systems that evolve for a long time. We compute the number of bits that remain continuously significant in the first two applications with a probability of failure around one out of a billion, where worst case analysis considers that no significant bit remains. We are using PVS as such formal tools force explicit statement of all hypotheses and prevent incorrect uses of theorems.

  5. A Formal Basis for Safety Case Patterns

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Pai, Ganesh

    2013-01-01

    By capturing common structures of successful arguments, safety case patterns provide an approach for reusing strategies for reasoning about safety. In the current state of the practice, patterns exist as descriptive specifications with informal semantics, which not only offer little opportunity for more sophisticated usage such as automated instantiation, composition and manipulation, but also impede standardization efforts and tool interoperability. To address these concerns, this paper gives (i) a formal definition for safety case patterns, clarifying both restrictions on the usage of multiplicity and well-founded recursion in structural abstraction, (ii) formal semantics to patterns, and (iii) a generic data model and algorithm for pattern instantiation. We illustrate our contributions by application to a new pattern, the requirements breakdown pattern, which builds upon our previous work

  6. A Formal Framework for Workflow Analysis

    NASA Astrophysics Data System (ADS)

    Cravo, Glória

    2010-09-01

    In this paper we provide a new formal framework to model and analyse workflows. A workflow is the formal definition of a business process that consists in the execution of tasks in order to achieve a certain objective. In our work we describe a workflow as a graph whose vertices represent tasks and the arcs are associated to workflow transitions. Each task has associated an input/output logic operator. This logic operator can be the logical AND (•), the OR (⊗), or the XOR -exclusive-or—(⊕). Moreover, we introduce algebraic concepts in order to completely describe completely the structure of workflows. We also introduce the concept of logical termination. Finally, we provide a necessary and sufficient condition for this property to hold.

  7. Generalizing Prototype Theory: A Formal Quantum Framework

    PubMed Central

    Aerts, Diederik; Broekaert, Jan; Gabora, Liane; Sozzo, Sandro

    2016-01-01

    Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper. PMID:27065436

  8. Formal Management of CAD/CAM Processes

    NASA Astrophysics Data System (ADS)

    Kohlhase, Michael; Lemburg, Johannes; Schröder, Lutz; Schulz, Ewaryst

    Systematic engineering design processes have many aspects in common with software engineering, with CAD/CAM objects replacing program code as the implementation stage of the development. They are, however, currently considerably less formal. We propose to draw on the mentioned similarities and transfer methods from software engineering to engineering design in order to enhance in particular the reliability and reusability of engineering processes. We lay out a vision of a document-oriented design process that integrates CAD/CAM documents with requirement specifications; as a first step towards supporting such a process, we present a tool that interfaces a CAD system with program verification workflows, thus allowing for completely formalised development strands within a semi-formal methodology.

  9. Analyzing phonetic confusions using formal concept analysis.

    PubMed

    Peláez-Moreno, C; García-Moral, A I; Valverde-Albacete, F J

    2010-09-01

    Confusion matrices have been used as a tool for the analysis of speech perception or human speech recognition (HSR) for decades. However, they are rarely employed in automatic speech recognition (ASR) mainly due to the lack of a systematic procedure for their exploration. The generalization of formal concept analysis employed in this paper provides a conceptual interpretation of confusion matrices that enables the analysis of the structure of confusions for both human and machine performances. Generalized formal concept analysis transforms confusion matrices into ordered lattices of confusion events, supporting classic results in HSR that identify a hierarchy of virtual articulatory-acoustic channels. Translating this technique into ASR, a detailed map of the relationships among the speech units employed in the system can be traced to make different sources of confusions apparent: the influence of the lexicon, segmentation errors, dialectal variations or limitations of the feature extraction procedures, among others. PMID:20815472

  10. Flexible receiver adapter formal design review

    SciTech Connect

    Krieg, S.A.

    1995-06-13

    This memo summarizes the results of the Formal (90%) Design Review process and meetings held to evaluate the design of the Flexible Receiver Adapters, support platforms, and associated equipment. The equipment is part of the Flexible Receiver System used to remove, transport, and store long length contaminated equipment and components from both the double and single-shell underground storage tanks at the 200 area tank farms.

  11. Decidability of formal theories and hyperincursivity theory

    NASA Astrophysics Data System (ADS)

    Grappone, Arturo G.

    2000-05-01

    This paper shows the limits of the Proof Standard Theory (briefly, PST) and gives some ideas of how to build a proof anticipatory theory (briefly, PAT) that has no such limits. Also, this paper considers that Gödel's proof of the undecidability of Principia Mathematica formal theory is not valid for axiomatic theories that use a PAT to build their proofs because the (hyper)incursive functions are self-representable.

  12. Fourth NASA Langley Formal Methods Workshop

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael (Compiler); Hayhurst, Kelly J. (Compiler)

    1997-01-01

    This publication consists of papers presented at NASA Langley Research Center's fourth workshop on the application of formal methods to the design and verification of life-critical systems. Topic considered include: Proving properties of accident; modeling and validating SAFER in VDM-SL; requirement analysis of real-time control systems using PVS; a tabular language for system design; automated deductive verification of parallel systems. Also included is a fundamental hardware design in PVS.

  13. Terra in K-16 formal education settings

    NASA Astrophysics Data System (ADS)

    Chambers, L. H.; Fischer, J. D.; Lewis, P. M.; Moore, S. W.; Oots, P. C.; Rogerson, T. M.; Hitke, K. M.; Riebeek, H.

    2009-12-01

    Since it began, the Terra mission has had an active presence in formal education at the K-16 level. This educational presence was provided through the S’COOL project for the first five years of the mission, joined by the MY NASA DATA project for the second five years. The Students’ Cloud Observations On-Line (S’COOL) Project, begun in 1997 under the auspices of the Clouds and the Earth’s Radiant Energy System (CERES) project, seeks to motivate students across the entire K-12 spectrum to learn science basics and how they tie in to a larger picture. Beginning early on, college level participants have also participated in the project, both in science classes and in science education coursework. The project uses the connection to an on-going NASA science investigation as a powerful motivator for student observations, analysis and learning, and has reached around the globe as shown in the world map. This poster will review the impact that Terra, through S’COOL, has made in formal education over the last decade. The MY NASA DATA Project began in 2004 under the NASA Research, Education and Applications Solutions Network (REASoN). A 5-year REASoN grant enabled the creation of an extensive website which wraps easily accessible Earth science data - including Terra parameters from CERES (involving MODIS data fusion), MISR, and MOPITT (an example for carbon monoxide is given in the graph, with dark areas indicating high CO levels) - with explanatory material written at the middle school level, and an extensive collection of peer-reviewed lesson plans. The MY NASA DATA site has a rapidly growing user-base and was recently adopted by a number of NASA Earth Science missions, in addition to Terra, as a formal education arm of their Education and Public Outreach efforts. This poster will summarize the contributions that Terra, through MY NASA DATA, has made to formal education since 2004.

  14. Toward a Formal Evaluation of Refactorings

    NASA Technical Reports Server (NTRS)

    Paul, John; Kuzmina, Nadya; Gamboa, Ruben; Caldwell, James

    2008-01-01

    Refactoring is a software development strategy that characteristically alters the syntactic structure of a program without changing its external behavior [2]. In this talk we present a methodology for extracting formal models from programs in order to evaluate how incremental refactorings affect the verifiability of their structural specifications. We envision that this same technique may be applicable to other types of properties such as those that concern the design and maintenance of safety-critical systems.

  15. Carbonate fuel cell matrix

    DOEpatents

    Farooque, M.; Yuh, C.Y.

    1996-12-03

    A carbonate fuel cell matrix is described comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles. 8 figs.

  16. Carbonate fuel cell matrix

    DOEpatents

    Farooque, Mohammad; Yuh, Chao-Yi

    1996-01-01

    A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.

  17. Extension of Liouville Formalism to Postinstability Dynamics

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2003-01-01

    A mathematical formalism has been developed for predicting the postinstability motions of a dynamic system governed by a system of nonlinear equations and subject to initial conditions. Previously, there was no general method for prediction and mathematical modeling of postinstability behaviors (e.g., chaos and turbulence) in such a system. The formalism of nonlinear dynamics does not afford means to discriminate between stable and unstable motions: an additional stability analysis is necessary for such discrimination. However, an additional stability analysis does not suggest any modifications of a mathematical model that would enable the model to describe postinstability motions efficiently. The most important type of instability that necessitates a postinstability description is associated with positive Lyapunov exponents. Such an instability leads to exponential growth of small errors in initial conditions or, equivalently, exponential divergence of neighboring trajectories. The development of the present formalism was undertaken in an effort to remove positive Lyapunov exponents. The means chosen to accomplish this is coupling of the governing dynamical equations with the corresponding Liouville equation that describes the evolution of the flow of error probability. The underlying idea is to suppress the divergences of different trajectories that correspond to different initial conditions, without affecting a target trajectory, which is one that starts with prescribed initial conditions.

  18. [How to write an article: formal aspects].

    PubMed

    Corral de la Calle, M A; Encinas de la Iglesia, J

    2013-06-01

    Scientific research and the publication of the results of the studies go hand in hand. Exquisite research methods can only be adequately reflected in formal publication with the optimum structure. To ensure the success of this process, it is necessary to follow orderly steps, including selecting the journal in which to publish and following the instructions to authors strictly as well as the guidelines elaborated by diverse societies of editors and other institutions. It is also necessary to structure the contents of the article in a logical and attractive way and to use an accurate, clear, and concise style of language. Although not all the authors are directly involved in the actual writing, elaborating a scientific article is a collective undertaking that does not finish until the article is published. This article provides practical advice about formal and not-so-formal details to take into account when writing a scientific article as well as references that will help readers find more information in greater detail. PMID:23489765

  19. Matrix differentiation formulas

    NASA Technical Reports Server (NTRS)

    Usikov, D. A.; Tkhabisimov, D. K.

    1983-01-01

    A compact differentiation technique (without using indexes) is developed for scalar functions that depend on complex matrix arguments which are combined by operations of complex conjugation, transposition, addition, multiplication, matrix inversion and taking the direct product. The differentiation apparatus is developed in order to simplify the solution of extremum problems of scalar functions of matrix arguments.

  20. Matrix with Prescribed Eigenvectors

    ERIC Educational Resources Information Center

    Ahmad, Faiz

    2011-01-01

    It is a routine matter for undergraduates to find eigenvalues and eigenvectors of a given matrix. But the converse problem of finding a matrix with prescribed eigenvalues and eigenvectors is rarely discussed in elementary texts on linear algebra. This problem is related to the "spectral" decomposition of a matrix and has important technical…

  1. Rapid Mueller matrix polarimetry imaging based on four photoelastic modulators with no moving parts (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Gribble, Adam; Alali, Sanaz; Vitkin, Alex

    2016-03-01

    Polarized light has many applications in biomedical imaging. The interaction of a biological sample with polarized light reveals information about its composition, both structural and functional. For example, the polarimetry-derived metric of linear retardance (birefringence) is dependent on tissue structural organization (anisotropy) and can be used to diagnose myocardial infarct; circular birefringence (optical rotation) can measure glucose concentrations. The most comprehensive type of polarimetry analysis is to measure the Mueller matrix, a polarization transfer function that completely describes how a sample interacts with polarized light. To derive this 4x4 matrix it is necessary to observe how a tissue interacts with different polarizations. A well-suited approach for tissue polarimetry is to use photoelastic modulators (PEMs), which dynamically modulate the polarization of light. Previously, we have demonstrated a rapid time-gated Stokes imaging system that is capable of characterizing the state of polarized light (the Stokes vector) over a large field, after interacting with any turbid media. This was accomplished by synchronizing CCD camera acquisition times relative to two PEMs using a field-programmable gate array (FPGA). Here, we extend this technology to four PEMs, yielding a polarimetry system that is capable of rapidly measuring the complete sample Mueller matrix over a large field of view, with no moving parts and no beam steering. We describe the calibration procedure and evaluate the accuracy of the measurements. Results are shown for tissue-mimicking phantoms, as well as initial biological samples.

  2. Quaternionic Variational Formalism for General Relativity in Riemann and Riemann-Cartan Space-Times

    NASA Astrophysics Data System (ADS)

    Morita, K.

    2012-12-01

    It is shown that there exists a 2-dimensional matrix representation of complex quaternions over real quaternions, which allows to define Pauli matrix in 4 dimensions over the quaternionic field and leads to the quaternionic spinor group previously proposed. It is also attempted to apply complex quaternions to general relativity at the level of the variational formalism. Linear gravitational Lagrangian in Riemann-Cartan space-time U_4 is derived using quaternion caluculus; namely scalar curvature in U_4 is put into a quaternionic form. Consequently, Einstein-Hilbert Lagrangian in Riemann space R_4 is also defined over quaternions, as first shown by Sachs. The matter fields coupled to gravity are assumed to be the scalar and the Dirac fields. The quaternionic variational formalism corresponds to the first-order formalism but with a limited pattern of allowed fields such that the quaternionic fields carry only coordinate tensor indices but no local Lorentz indices which are contracted with that possessed by the basis of complex quaternions. In particular, both the quaternionic vierbein field and Lorentz gauge field (corresponding to the spin connection) are regarded as coordinate vectors which are independently varied, obtaining Einstein and Cartan equations, respectively. It is incidentally shown that the consistent condition of Einstein equation in U_4 is proved via the variational formalism and the anti-symmetric part of Einstein equation together with Cartan equation in U_4 leads to an identity which expresses the anti-symmetric part of the enegy-momentum tensor by means of the covariant divergence of the spin angular momentum tensor, both of Dirac field. We also present pedagogical proofs of Bianchi and Bach-Lanczos identities in U_4 using the quaternionic formalism.

  3. Nanocrystal doped matrixes

    DOEpatents

    Parce, J. Wallace; Bernatis, Paul; Dubrow, Robert; Freeman, William P.; Gamoras, Joel; Kan, Shihai; Meisel, Andreas; Qian, Baixin; Whiteford, Jeffery A.; Ziebarth, Jonathan

    2010-01-12

    Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided. Nanostructures having high quantum efficiency, small size, and/or a narrow size distribution are also described, as are methods of producing indium phosphide nanostructures and core-shell nanostructures with Group II-VI shells.

  4. Systematic errors for a Mueller matrix dual rotating compensator ellipsometer.

    PubMed

    Broch, Laurent; En Naciri, Aotmane; Johann, Luc

    2008-06-01

    The characterization of anisotropic materials and complex systems by ellipsometry has pushed the design of instruments to require the measurement of the full reflection Mueller matrix of the sample with a great precision. Therefore Mueller matrix ellipsometers have emerged over the past twenty years. The values of some coefficients of the matrix can be very small and errors due to noise or systematic errors can induce distored analysis. We present a detailed characterization of the systematic errors for a Mueller Matrix Ellipsometer in the dual-rotating compensator configuration. Starting from a general formalism, we derive explicit first-order expressions for the errors on all the coefficients of the Mueller matrix of the sample. The errors caused by inaccuracy of the azimuthal arrangement of the optical components and residual ellipticity introduced by imperfect optical elements are shown. A new method based on a four-zone averaging measurement is proposed to vanish the systematic errors. PMID:18545594

  5. A Formal Mentorship Program for Faculty Development

    PubMed Central

    Le, Jennifer; Nazer, Lama; Hess, Karl; Wang, Jeffrey; Law, Anandi V.

    2014-01-01

    Objective. To describe the development, implementation, and evaluation of a formal mentorship program at a college of pharmacy. Methods. After extensive review of the mentorship literature within the health sciences, a formal mentorship program was developed between 2006 and 2008 to support and facilitate faculty development. The voluntary program was implemented after mentors received training, and mentors and protégés were matched and received an orientation. Evaluation consisted of conducting annual surveys and focus groups with mentors and protégés. Results. Fifty-one mentor-protégé pairs were formed from 2009 to 2012. A large majority of the mentors (82.8%-96.9%) were satisfied with the mentorship program and its procedures. The majority of the protégés (≥70%) were satisfied with the mentorship program, mentor-protégé relationship, and program logistics. Both mentors and protégés reported that the protégés most needed guidance on time management, prioritization, and work-life balance. While there were no significant improvements in the proteges’ number of grant submissions, retention rates, or success in promotion/tenure, the total number of peer-reviewed publications by junior faculty members was significantly higher after program implementation (mean of 7 per year vs 21 per year, p=0.03) in the college’s pharmacy practice and administration department. Conclusions. A formal mentorship program was successful as measured by self-reported assessments of mentors and protégés. PMID:24954940

  6. Formal Assurance Arguments: A Solution In Search of a Problem?

    NASA Technical Reports Server (NTRS)

    Graydon, Patrick J.

    2015-01-01

    An assurance case comprises evidence and argument showing how that evidence supports assurance claims (e.g., about safety or security). It is unsurprising that some computer scientists have proposed formalizing assurance arguments: most associate formality with rigor. But while engineers can sometimes prove that source code refines a formal specification, it is not clear that formalization will improve assurance arguments or that this benefit is worth its cost. For example, formalization might reduce the benefits of argumentation by limiting the audience to people who can read formal logic. In this paper, we present (1) a systematic survey of the literature surrounding formal assurance arguments, (2) an analysis of errors that formalism can help to eliminate, (3) a discussion of existing evidence, and (4) suggestions for experimental work to definitively answer the question.

  7. Application of the green function formalism to nonlinear evolution of the low gain FEL oscillator

    SciTech Connect

    Shvets, G.; Wurtele, J.S.; Gardent, D.

    1995-12-31

    A matrix formalism for the optical pulse evolution in the frequency domain, is applied to the nonlinear regime of operation. The formalism was previously developed for studies of the linear evolution of the low-gain FEL oscillator with an arbitrary shape of the electron beam. By varying experimentally controllable parameters, such as cavity detunning and cavity losses, different regimes of operation of the FEL oscillator, such as a steady state saturation and limit cycle saturation, are studied numerically. It is demonstrated that the linear supermodes, numerically obtained from the matrix formalism, provide an appropriate framework for analyzing the periodic change in the output power in the limit cycle regime. The frequency of this oscillation is related to the frequencies of the lowest-order linear supermodes. The response of the output radiation to periodic variation of the electron energy is studied. It is found that the response is enhanced when the frequency of the energy variation corresponds to the difference of per-pass phase advances of the lowest linear supermodes. Finally, various nonlinear models are tested to capture the steady state saturation and limit cycle variation of the EM field in the oscillator cavity.

  8. Does Formal Employment Reduce Informal Caregiving?

    PubMed

    He, Daifeng; McHenry, Peter

    2016-07-01

    Using the Survey of Income and Program Participation, we examine the impact of formal employment on informal caregiving. We instrument for individual work hours with state unemployment rates. We find that, among women of prime caregiving ages (40-64 years), working 10% more hours per week reduces the probability of providing informal care by about 2 percentage points. The effects are stronger for more time-intensive caregiving and if care recipients are household members. Our results imply that work-promoting policies have the unintended consequence of reducing informal caregiving in an aging society. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26017375

  9. The formal verification of generic interpreters

    NASA Technical Reports Server (NTRS)

    Windley, P.; Levitt, K.; Cohen, G. C.

    1991-01-01

    The task assignment 3 of the design and validation of digital flight control systems suitable for fly-by-wire applications is studied. Task 3 is associated with formal verification of embedded systems. In particular, results are presented that provide a methodological approach to microprocessor verification. A hierarchical decomposition strategy for specifying microprocessors is also presented. A theory of generic interpreters is presented that can be used to model microprocessor behavior. The generic interpreter theory abstracts away the details of instruction functionality, leaving a general model of what an interpreter does.

  10. QED spectra in the path integral formalism

    NASA Astrophysics Data System (ADS)

    Simonov, Yu. A.

    2014-07-01

    Relativistic Hamiltonians, derived from the path integrals, are known to provide a simple and useful formalism for hadron spectroscopy in QCD. The accuracy of this approach is tested using the QED systems, and the calculated spectrum is shown to reproduce exactly that of the Dirac hydrogen atom, while the Breit-Fermi nonrelativistic expansion is obtained using Foldy-Wouthuizen transformation. The calculated positronium spectrum, including spin-dependent terms, coincides with the standard QED perturbation theory to the considered order O(α4).

  11. Representations of spacetime: Formalism and ontological commitment

    NASA Astrophysics Data System (ADS)

    Bain, Jonathan Stanley

    This dissertation consists of two parts. The first is on the relation between formalism and ontological commitment in the context of theories of spacetime, and the second is on scientific realism. The first part begins with a look at how the substantivalist/relationist debate over the ontological status of spacetime has been influenced by a particular mathematical formalism, that of tensor analysis on differential manifolds (TADM). This formalism has motivated the substantivalist position known as manifold substantivalism. Chapter 1 focuses on the hole argument which maintains that manifold substantivalism is incompatible with determinism. I claim that the realist motivations underlying manifold substantivalism can be upheld, and the hole argument avoided, by adopting structural realism with respect to spacetime. In this context, this is the claim that it is the structure that spacetime points enter into that warrants belief and not the points themselves. In Chapter 2, an elimination principle is defined by means of which a distinction can be made between surplus structure and essential structure with respect to formulations of a theory in two distinct mathematical formulations and some prior ontological commitments. This principle is then used to demonstrate that manifold points may be considered surplus structure in the formulation of field theories. This suggests that, if we are disposed to read field theories literally, then, at most, it should be the essential structure common to all alternative formulations of such theories that should be taken literally. I also investigate how the adoption of alternative formalisms informs other issues in the philosophy of spacetime. Chapter 3 offers a realist position which takes a semantic moral from the preceding investigation and an epistemic moral from work done on reliability. The semantic moral advises us to read only the essential structure of our theories literally. The epistemic moral shows us that such structure

  12. Results of a Formal Methods Demonstration Project

    NASA Technical Reports Server (NTRS)

    Kelly, J.; Covington, R.; Hamilton, D.

    1994-01-01

    This paper describes the results of a cooperative study conducted by a team of researchers in formal methods at three NASA Centers to demonstrate FM techniques and to tailor them to critical NASA software systems. This pilot project applied FM to an existing critical software subsystem, the Shuttle's Jet Select subsystem (Phase I of an ongoing study). The present study shows that FM can be used successfully to uncover hidden issues in a highly critical and mature Functional Subsystem Software Requirements (FSSR) specification which are very difficult to discover by traditional means.

  13. Formal Verification of Large Software Systems

    NASA Technical Reports Server (NTRS)

    Yin, Xiang; Knight, John

    2010-01-01

    We introduce a scalable proof structure to facilitate formal verification of large software systems. In our approach, we mechanically synthesize an abstract specification from the software implementation, match its static operational structure to that of the original specification, and organize the proof as the conjunction of a series of lemmas about the specification structure. By setting up a different lemma for each distinct element and proving each lemma independently, we obtain the important benefit that the proof scales easily for large systems. We present details of the approach and an illustration of its application on a challenge problem from the security domain

  14. Formal Aspects of Human-Automation Interaction

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Heymann, Michael; Moodi, Michael; Remington, Roger (Technical Monitor)

    1998-01-01

    While new versions of automated control systems such as flight guidance systems are introduced at a rapid pace, it is widely recognized that user interaction with these machines is increasingly problematic. One cause for this difficulty that is commonly cited in the literature, is the discrepancy between the machine's behavior and the operator's (e.g., pilot) expectations. This paper discusses a formal approach to the analysis of operator's interaction with complex automated control systems. We focus attention on the issue of interface correctness; that is, on the question whether the display provides adequate information about the machine's configurations (states, modes, and associated parameters) and transitions, so as to enable the operator to successfully perform the specified set of tasks. To perform the analysis several assumptions are made: (1) A complete formal model of the machine's behavior is available (e.g., as a state transition system, or as a hybrid-machine); (2) A specification of operator's tasks is available and can be formally described (e.g., the reliable and predictable transition between activities involved in executing a climb to a new altitude); (3) The pilot is well trained and has a correct 'mental' model of the machine's response-map. By 'comparing' the machine's model with the set of operator's tasks we formally (i.e., mathematically) evaluate two questions: 1) does the machine's output interface (display) enable the operator to determine, unambiguously, what the current configuration (e.g., mode) of the machine is, and 2) does the display enable the operator to determine, unambiguously, what the next configuration of the machine will be, in response to a specified interaction by the operator (e.g., engaging a mode or changing a parameter such as a speed or target altitude). This paper describes a methodology for conducting such an evaluation using examples from automated flight control systems of modem 'glass cockpit' jetliners

  15. BRST and the pure spinor formalism

    SciTech Connect

    Garcia, J. Antonio

    2008-03-06

    The aim of this talk is to show the relation between the standard BRST approach of the GS superstring with the quantization technics used in the pure spinor approach to superstring. To that end we will use the Batalin-Fradkin-Tyutin (BFT) conversion program of second class constraints to first class constraints in the GS superstring using light cone coordinates. By applying this systematic procedure we were able to obtain a gauge system that is equivalent to the recent model proposed in [1] to relate the GS superstring to the pure spinor formalism.

  16. Hamilton-Jacobi formalism for tachyon inflation

    NASA Astrophysics Data System (ADS)

    Aghamohammadi, A.; Mohammadi, A.; Golanbari, T.; Saaidi, Kh.

    2014-10-01

    Tachyon inflation is reconsidered by using the recent observational data obtained from Planck-2013 and BICEP2. The Hamilton-Jacobi formalism is picked out as a desirable approach in this work, which allows one to easily obtain the main parameters of the model. The Hubble parameter is supposed as a power-law and exponential function of the scalar field, and each case is considered separately. The constraints on the model, which come from observational data, are explained during the work. The results show a suitable value for the tensor spectral index and an appropriate form of the potential.

  17. Formal analysis of ORM using OWL DL

    NASA Astrophysics Data System (ADS)

    Pan, Wen-lin; Liu, Da-xin

    2012-01-01

    ORM (Object Role Modeling), current version is 2.0, is a fully communication oriented information modeling method. Currently, ORM has been used in ontology engineering to model domain ontologies. To ensure the semantics of ORM model is consistent, it needs using reasoning engines to check semantic conflicts and redundancy. Furthermore, only publish ORM domain ontologies on the Semantic Web described by OWL can it is shared by different applications. Therefore, it needs to map ORM models into OWL DL. Several methods to transform ORM models have been considered and a series of general OWL DL formalization rules have been proposed.

  18. Formal analysis of ORM using OWL DL

    NASA Astrophysics Data System (ADS)

    Pan, Wen-Lin; Liu, Da-Xin

    2011-12-01

    ORM (Object Role Modeling), current version is 2.0, is a fully communication oriented information modeling method. Currently, ORM has been used in ontology engineering to model domain ontologies. To ensure the semantics of ORM model is consistent, it needs using reasoning engines to check semantic conflicts and redundancy. Furthermore, only publish ORM domain ontologies on the Semantic Web described by OWL can it is shared by different applications. Therefore, it needs to map ORM models into OWL DL. Several methods to transform ORM models have been considered and a series of general OWL DL formalization rules have been proposed.

  19. Towards a Formalization of Digital Forensics

    NASA Astrophysics Data System (ADS)

    Slay, Jill; Lin, Yi-Chi; Turnbull, Benjamin; Beckett, Jason; Lin, Paul

    While some individuals have referred to digital forensics as an art, the literature of the discipline suggests a trend toward the formalization of digital forensics as a forensic science. Questions about the quality of digital evidence and forensic soundness continue to be raised by researchers and practitioners in order to ensure the trustworthiness of digital evidence and its value to the courts. This paper reviews the development of digital forensic models, procedures and standards to lay a foundation for the discipline. It also points to new work that provides validation models through a complete mapping of the discipline.

  20. The stochastic tetrad magneto-hydrodynamics via functional formalism

    NASA Astrophysics Data System (ADS)

    Materassi, Massimo; Consolini, Giuseppe

    2015-12-01

    > In this work we discuss an application of the Tetrad Dynamics approach, a stochastic dynamical theory already introduced in hydrodynamic turbulence, to incompressible magneto-hydrodynamics. This theoretical framework is capable of taking into account some crucial aspects of turbulent plasmas, namely, (i) its material nature, which is stressed through the adoption of Lagrangian variables, (ii) its probabilistic dynamics, which is fundamental to understand the intermittency and highly irregular nature of turbulence, and (iii) the multi-scale character of interactions, which is approached by promoting the space size of parcels to the role of a dynamical variable. In particular, here, we construct the probabilistic equations of motion for quantities describing the evolution of a turbulent plasma (a matrix describing the parcel's shape, the plasma velocity and magnetic field coarse-grained gradient tensors, and ), resorting the functional formalism of classical statistical dynamics. Through the introduction of a stochastic action and using a path integral approach, the statistical properties of can be derived from those of noises appearing in their equations of motion, both at equilibrium and out of equilibrium.

  1. Matrix representation of the time operator

    SciTech Connect

    Bender, Carl M.; Gianfreda, Mariagiovanna

    2012-06-15

    In quantum mechanics the time operator {Theta} satisfies the commutation relation [{Theta}, H]=i, and thus it may be thought of as being formally canonically conjugate to the Hamiltonian H. The time operator associated with a given Hamiltonian H is not unique because one can replace {Theta} by {Theta}+{Theta}{sub hom}, where {Theta}{sub hom} satisfies the homogeneous condition [{Theta}{sub hom}, H]= 0. To study this nonuniqueness the matrix elements of {Theta} for the harmonic-oscillator Hamiltonian are calculated in the eigenstate basis. This calculation requires the summation of divergent series, and the summation is accomplished by using zeta-summation techniques. It is shown that by including appropriate homogeneous contributions, the matrix elements of {Theta} simplify dramatically. However, it is still not clear whether there is an optimally simple representation of the time operator.

  2. Matrix product states for gauge field theories.

    PubMed

    Buyens, Boye; Haegeman, Jutho; Van Acoleyen, Karel; Verschelde, Henri; Verstraete, Frank

    2014-08-29

    The matrix product state formalism is used to simulate Hamiltonian lattice gauge theories. To this end, we define matrix product state manifolds which are manifestly gauge invariant. As an application, we study (1+1)-dimensional one flavor quantum electrodynamics, also known as the massive Schwinger model, and are able to determine very accurately the ground-state properties and elementary one-particle excitations in the continuum limit. In particular, a novel particle excitation in the form of a heavy vector boson is uncovered, compatible with the strong coupling expansion in the continuum. We also study full quantum nonequilibrium dynamics by simulating the real-time evolution of the system induced by a quench in the form of a uniform background electric field. PMID:25215973

  3. 25 CFR 151.14 - Formalization of acceptance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Formalization of acceptance. 151.14 Section 151.14 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER LAND ACQUISITIONS § 151.14 Formalization of acceptance. Formal acceptance of land in trust status shall be accomplished by the issuance...

  4. Communicating More than Content: Formal Features of Children's Television Programs.

    ERIC Educational Resources Information Center

    Huston, Aletha C.; And Others

    1981-01-01

    Presents a taxonomy of formal features of television and examines ways in which these features are used in current productions for children. Coding categories for formal features include action, pace, visual events, and auditory features. Concludes that commercial producers stress formal features as much or more than content. (PD)

  5. 25 CFR 151.14 - Formalization of acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Formalization of acceptance. 151.14 Section 151.14 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER LAND ACQUISITIONS § 151.14 Formalization of acceptance. Formal acceptance of land in trust status shall be accomplished by the issuance...

  6. Is Lawson's Classroom Test of Formal Reasoning Valid?

    ERIC Educational Resources Information Center

    Pratt, C.; Hacker, R. G.

    1984-01-01

    A unidimensional latent trait model was used to test a single-factor hypothesis of the Lawson Classroom Test of Formal Reasoning. The test failed to provide a valid measure of formal reasoning. This was a result of test format which neglected aspects of formal reasoning emphasized by Inhelder and Piaget. (Author/DWH)

  7. "Passing It On": Beyond Formal or Informal Pedagogies

    ERIC Educational Resources Information Center

    Cain, Tim

    2013-01-01

    Informal pedagogies are a subject of debate in music education, and there is some evidence of teachers abandoning formal pedagogies in favour of informal ones. This article presents a case of one teacher's formal pedagogy and theorises it by comparing it with a case of informal pedagogy. The comparison reveals affordances of formal pedagogies…

  8. How External Institutions Penetrate Schools through Formal and Informal Leaders

    ERIC Educational Resources Information Center

    Sun, Min; Frank, Kenneth A.; Penuel, William R.; Kim, Chong Min

    2013-01-01

    Purposes: This study investigates the role of formal and informal leaders in the diffusion of external reforms into schools and to teachers' practices. Formal leaders are designated by their roles in the formal organization of the school (e.g., principals, department chairs, and instructional coaches) and informal leaders refer to those who…

  9. Generalized Boltzmann formalism for oscillating neutrinos

    SciTech Connect

    Strack, P.; Burrows, A.

    2005-05-01

    In the standard approaches to neutrino transport in the simulation of core-collapse supernovas, one will often start from the classical Boltzmann equation for the neutrino's spatial, temporal, and spectral evolution. For each neutrino species, and its antiparticle, the classical density in phase space, or the associated specific intensity, will be calculated as a function of time. The neutrino radiation is coupled to matter by source and sink terms on the 'right-hand side' of the transport equation and together with the equations of hydrodynamics this set of coupled partial differential equations for classical densities describes, in principle, the evolution of core collapse and explosion. However, with the possibility of neutrino oscillations between species, a purely quantum-physical effect, how to generalize this set of Boltzmann equations for classical quantities to reflect oscillation physics has not been clear. To date, the formalisms developed have retained the character of quantum operator physics involving complex quantities and have not been suitable for easy incorporation into standard supernova codes. In this paper, we derive generalized Boltzmann equations for quasiclassical, real-valued phase-space densities that retain all the standard oscillation phenomenology, including the matter-enhanced resonant flavor conversion (Mikheev-Smirnov-Wolfenstein effect), neutrino self-interactions, and the interplay between decohering matter coupling and flavor oscillations. With this formalism, any code(s) that can now handle the solution of the classical Boltzmann or transport equation can easily be generalized to include neutrino oscillations in a quantum-physically consistent fashion.

  10. Affine gravity, Palatini formalism and charges

    NASA Astrophysics Data System (ADS)

    Katz, Joseph; Livshits, Gideon I.

    2011-12-01

    Affine gravity and the Palatini formalism contribute both to produce a simple and unique formula for calculating charges at spatial and null infinity for Lovelock type Lagrangians whose variational derivatives do not depend on second-order derivatives of the field components. The method is based on the covariant generalization due to Julia and Silva of the Regge-Teitelboim procedure that was used to define properly the mass in the classical formulation of Einstein's theory of gravity. Numerous applications reproduce standard results obtained by other secure but mostly specialized method like in ADM energy for asymptotically flat spacetimes and in Abbot and Deser for asymptotically de Sitter and anti-de Sitter spacetimes, both at spatial infinity. As a novel application we calculate the Bondi energy loss in five dimensional gravity, based on the asymptotic solution given by Tanabe et al. and obtain, as expected, the same result. We also give the for Einstein-Gauss-Bonnet gravity and find the superpotential for Lovelock theories of gravity when the number of dimensions tends to infinity with maximally symmetrical boundaries. The paper is written in standard component formalism.

  11. Formality Theorem for Hochschild Cochains via Transfer

    NASA Astrophysics Data System (ADS)

    Dolgushev, Vasily

    2011-08-01

    We construct a 2-colored operad Ger ∞ which, on the one hand, extends the operad Ger ∞ governing homotopy Gerstenhaber algebras and, on the other hand, extends the 2-colored operad governing open-closed homotopy algebras. We show that Tamarkin's Ger ∞-structure on the Hochschild cochain complex C •( A, A) of an A ∞-algebra A extends naturally to a {{Ger}^+_{infty}}-structure on the pair ( C •( A, A), A). We show that a formality quasi-isomorphism for the Hochschild cochains of the polynomial algebra can be obtained via transfer of this {{Ger}^+_{infty}}-structure to the cohomology of the pair ( C •( A, A), A). We show that {{Ger}^+_{infty}} is a sub DG operad of the first sheet E 1(SC) of the homology spectral sequence for the Fulton-MacPherson version SC of Voronov's Swiss Cheese operad. Finally, we prove that the DG operads {{Ger}^+_{infty}} and E 1(SC) are non-formal.

  12. ADM canonical formalism for gravitating spinning objects

    SciTech Connect

    Steinhoff, Jan; Schaefer, Gerhard; Hergt, Steven

    2008-05-15

    In general relativity, systems of spinning classical particles are implemented into the canonical formalism of Arnowitt, Deser, and Misner [R. Arnowitt, S. Deser, and C. W. Misner, in Gravitation: An Introduction to Current Research, edited by L. Witten (Wiley, New York, 1962), p. 227; arXiv:gr-qc/0405109]. The implementation is made with the aid of a symmetric stress-energy tensor and not a 4-dimensional covariant action functional. The formalism is valid to terms linear in the single spin variables and up to and including the next-to-leading order approximation in the gravitational spin-interaction part. The field-source terms for the spinning particles occurring in the Hamiltonian are obtained from their expressions in Minkowski space with canonical variables through 3-dimensional covariant generalizations as well as from a suitable shift of projections of the curved spacetime stress-energy tensor originally given within covariant spin supplementary conditions. The applied coordinate conditions are the generalized isotropic ones introduced by Arnowitt, Deser, and Misner. As applications, the Hamiltonian of two spinning compact bodies with next-to-leading order gravitational spin-orbit coupling, recently obtained by Damour, Jaranowski, and Schaefer [Phys. Rev. D 77, 064032 (2008)], is rederived and the derivation of the next-to-leading order gravitational spin(1)-spin(2) Hamiltonian, shown for the first time in [J. Steinhoff, S. Hergt, and G. Schaefer, Phys. Rev. D 77, 081501(R) (2008)], is presented.

  13. A Formal Ontology of Subcellular Neuroanatomy

    PubMed Central

    Larson, Stephen D.; Fong, Lisa L.; Gupta, Amarnath; Condit, Christopher; Bug, William J.; Martone, Maryann E.

    2007-01-01

    The complexity of the nervous system requires high-resolution microscopy to resolve the detailed 3D structure of nerve cells and supracellular domains. The analysis of such imaging data to extract cellular surfaces and cell components often requires the combination of expert human knowledge with carefully engineered software tools. In an effort to make better tools to assist humans in this endeavor, create a more accessible and permanent record of their data, and to aid the process of constructing complex and detailed computational models, we have created a core of formalized knowledge about the structure of the nervous system and have integrated that core into several software applications. In this paper, we describe the structure and content of a formal ontology whose scope is the subcellular anatomy of the nervous system (SAO), covering nerve cells, their parts, and interactions between these parts. Many applications of this ontology to image annotation, content-based retrieval of structural data, and integration of shared data across scales and researchers are also described. PMID:18974798

  14. Integrating Formal Methods and Testing 2002

    NASA Technical Reports Server (NTRS)

    Cukic, Bojan

    2002-01-01

    Traditionally, qualitative program verification methodologies and program testing are studied in separate research communities. None of them alone is powerful and practical enough to provide sufficient confidence in ultra-high reliability assessment when used exclusively. Significant advances can be made by accounting not only tho formal verification and program testing. but also the impact of many other standard V&V techniques, in a unified software reliability assessment framework. The first year of this research resulted in the statistical framework that, given the assumptions on the success of the qualitative V&V and QA procedures, significantly reduces the amount of testing needed to confidently assess reliability at so-called high and ultra-high levels (10-4 or higher). The coming years shall address the methodologies to realistically estimate the impacts of various V&V techniques to system reliability and include the impact of operational risk to reliability assessment. Combine formal correctness verification, process and product metrics, and other standard qualitative software assurance methods with statistical testing with the aim of gaining higher confidence in software reliability assessment for high-assurance applications. B) Quantify the impact of these methods on software reliability. C) Demonstrate that accounting for the effectiveness of these methods reduces the number of tests needed to attain certain confidence level. D) Quantify and justify the reliability estimate for systems developed using various methods.

  15. Group adaptation, formal darwinism and contextual analysis.

    PubMed

    Okasha, S; Paternotte, C

    2012-06-01

    We consider the question: under what circumstances can the concept of adaptation be applied to groups, rather than individuals? Gardner and Grafen (2009, J. Evol. Biol.22: 659-671) develop a novel approach to this question, building on Grafen's 'formal Darwinism' project, which defines adaptation in terms of links between evolutionary dynamics and optimization. They conclude that only clonal groups, and to a lesser extent groups in which reproductive competition is repressed, can be considered as adaptive units. We re-examine the conditions under which the selection-optimization links hold at the group level. We focus on an important distinction between two ways of understanding the links, which have different implications regarding group adaptationism. We show how the formal Darwinism approach can be reconciled with G.C. Williams' famous analysis of group adaptation, and we consider the relationships between group adaptation, the Price equation approach to multi-level selection, and the alternative approach based on contextual analysis. PMID:22487485

  16. The simplest formal argument for fitness optimization.

    PubMed

    Grafen, Alen

    2008-12-01

    The Formal Darwinism Project aims to provide a formal argument linking population genetics to fitness optimization, which of necessity includes defining fitness. This bridges the gulf between those biologists who assume that natural selection leads to something close to fitness optimization and those biologists who believe on theoretical grounds that there is no sense of fitness that can usefully be said to be optimized. The current paper's main objective is to provide a careful mathematical introduction to the project, and it also reflects on the project's scope and limitations. The central argument is the proof of close ties between the mathematics of motion, as embodied in the Price equation, and the mathematics of optimization, as represented by optimization programmes. To make these links, a general and abstract model linking genotype, phenotype and number of successful gametes is assumed. The project has begun with simple dynamic models and simple linking models, and its progress will involve more realistic versions of them. The versions given here are fully mathematically rigorous, but elementary enough to serve as an introduction. PMID:19147931

  17. Biofilm Matrix Proteins

    PubMed Central

    Fong, Jiunn N. C.; Yildiz, Fitnat H.

    2015-01-01

    Proteinaceous components of the biofilm matrix include secreted extracellular proteins, cell surface adhesins and protein subunits of cell appendages such as flagella and pili. Biofilm matrix proteins play diverse roles in biofilm formation and dissolution. They are involved in attaching cells to surfaces, stabilizing the biofilm matrix via interactions with exopolysaccharide and nucleic acid components, developing three-dimensional biofilm architectures, and dissolving biofilm matrix via enzymatic degradation of polysaccharides, proteins, and nucleic acids. In this chapter, we will review functions of matrix proteins in a selected set of microorganisms, studies of the matrix proteomes of Vibrio cholerae and Pseudomonas aeruginosa, and roles of outer membrane vesicles and of nucleoid-binding proteins in biofilm formation. PMID:26104709

  18. Automatic switching matrix

    DOEpatents

    Schlecht, Martin F.; Kassakian, John G.; Caloggero, Anthony J.; Rhodes, Bruce; Otten, David; Rasmussen, Neil

    1982-01-01

    An automatic switching matrix that includes an apertured matrix board containing a matrix of wires that can be interconnected at each aperture. Each aperture has associated therewith a conductive pin which, when fully inserted into the associated aperture, effects electrical connection between the wires within that particular aperture. Means is provided for automatically inserting the pins in a determined pattern and for removing all the pins to permit other interconnecting patterns.

  19. Formal Psychological Assessment in Evaluating Depression: A New Methodology to Build Exhaustive and Irredundant Adaptive Questionnaires

    PubMed Central

    2015-01-01

    Psychological Assessment can be defined as a complex procedure of information collection, analysis and processing. Formal Psychological Assessment (FPA) tries to improve this procedure by providing a formal framework to build assessment tools. In this paper, FPA is applied to depression. Seven questionnaires widely used for the self-evaluation of depression were selected. Diagnostic criteria for major depressive disorder were derived from the DSM-5, literature and Seligman’s and Beck’s theories. A Boolean matrix was built, including 266 items from the questionnaires in the rows and 20 selected attributes, obtained through diagnostic criteria decomposition, in the columns. In the matrix, a 1 in a cell meant that the corresponding item investigated the specific attribute. It was thus possible to analyze the relationships between items and attributes and among items. While none of the considered questionnaires could alone cover all the criteria for the evaluation of depressive symptoms, we observed that a set of 30 items contained the same information that was obtained redundantly with 266 items. Another result highlighted by the matrix regards the relations among items. FPA allows in-depth analysis of currently used questionnaires based on the presence/absence of clinical elements. FPA allows for going beyond the mere score by differentiating the patients according to symptomatology. Furthermore, it allows for computerized-adaptive assessment. PMID:25875359

  20. Formal psychological assessment in evaluating depression: a new methodology to build exhaustive and irredundant adaptive questionnaires.

    PubMed

    Serra, Francesca; Spoto, Andrea; Ghisi, Marta; Vidotto, Giulio

    2015-01-01

    Psychological Assessment can be defined as a complex procedure of information collection, analysis and processing. Formal Psychological Assessment (FPA) tries to improve this procedure by providing a formal framework to build assessment tools. In this paper, FPA is applied to depression. Seven questionnaires widely used for the self-evaluation of depression were selected. Diagnostic criteria for major depressive disorder were derived from the DSM-5, literature and Seligman's and Beck's theories. A Boolean matrix was built, including 266 items from the questionnaires in the rows and 20 selected attributes, obtained through diagnostic criteria decomposition, in the columns. In the matrix, a 1 in a cell meant that the corresponding item investigated the specific attribute. It was thus possible to analyze the relationships between items and attributes and among items. While none of the considered questionnaires could alone cover all the criteria for the evaluation of depressive symptoms, we observed that a set of 30 items contained the same information that was obtained redundantly with 266 items. Another result highlighted by the matrix regards the relations among items. FPA allows in-depth analysis of currently used questionnaires based on the presence/absence of clinical elements. FPA allows for going beyond the mere score by differentiating the patients according to symptomatology. Furthermore, it allows for computerized-adaptive assessment. PMID:25875359

  1. Indigenous Knowledge and Education from the Quechua Community to School: Beyond the Formal/Non-Formal Dichotomy

    ERIC Educational Resources Information Center

    Sumida Huaman, Elizabeth; Valdiviezo, Laura Alicia

    2014-01-01

    In this article, we propose to approach Indigenous education beyond the formal/non-formal dichotomy. We argue that there is a critical need to conscientiously include Indigenous knowledge in education processes from the school to the community; particularly, when formal systems exclude Indigenous cultures and languages. Based on ethnographic…

  2. Guidance for Using Formal Methods in a Certification Context

    NASA Technical Reports Server (NTRS)

    Brown, Duncan; Delseny, Herve; Hayhurst, Kelly; Wiels, Virginie

    2010-01-01

    This paper discusses some of the challenges to using formal methods in a certification context and describes the effort by the Formal Methods Subgroup of RTCA SC-205/EUROCAE WG-71 to propose guidance to make the use of formal methods a recognized approach. This guidance, expected to take the form of a Formal Methods Technical Supplement to DO-178C/ED-12C, is described, including the activities that are needed when using formal methods, new or modified objectives with respect to the core DO-178C/ED-12C document, and evidence needed for meeting those objectives.

  3. If formal CME is ineffective, why do physicians still participate?

    PubMed

    McLeod, P J; McLeod, A H

    2004-03-01

    Formal or traditional CME can be criticized because organizers often ignore adult learning principles when designing courses. Critics also suggest that formal CME courses have limited impact on attendees' behaviors and practices. The authors agree that attention must be paid to pedagogic principles to assure success of educational courses, but feel that the extant negative evidence related to the impact of formal CME is narrow in scope and of inadequate strength to seriously damn formal approaches. Survey responses were received from 853 practicing physicians who say they still regularly attend formal CME courses. They are motivated to attend to satisfy specific professional needs and for personal reasons. Formal CME is still popular despite what its critics say. The authors are convinced that attention to physicians' perceived needs, effective use of social marketing strategies, and adherence to adult learning principles can assure successful delivery of CME and that formal CME is a useful complement to physician-driven informal CME. PMID:15203529

  4. Matrix cracking in ceramic-matrix composites

    SciTech Connect

    Danchaivijit, S.; Shetty, D.K. . Dept. of Materials Science and Engineering)

    1993-10-01

    Matrix cracking in ceramic-matrix composites with unbonded frictional interface has been studied using fracture mechanics theory. The critical stress for extension of a fiber-bridged crack has been analyzed using the stress-intensity approach. The analysis uses a new shear-lag formulation of the crack-closure traction applied by the bridging fibers based on the assumption of a constant sliding friction stress over the sliding length of the fiber-matrix interface. The new formulation satisfies two required limiting conditions: (a) when the stress in the bridging fiber approaches the far-field applied stress, the crack-opening displacement approaches a steady-state upper limit that is in agreement with the previous formulations; and (b) in the limit of zero crack opening, the stress in the bridging fiber approaches the far-field fiber stress. This lower limit of the bridging stress is distinctly different from the previous formulations. For all other conditions, the closure traction is a function of the far-field applied stress in addition to the local crack-opening displacement, the interfacial sliding friction stress, and the material properties. Numerical calculations using the stress-intensity approach indicate that the critical stress for crack extension decreases with increasing crack length and approaches a constant steady-state value for large cracks. The steady-state matrix-cracking stress agrees with a steady-state energy balance analysis applied to the continuum model, but it is slightly less than the matrix-cracking stress predicted by such theories of steady-state cracking as that of Aveston, Cooper, and Kelly. The origin of this difference and a method for reconciliation of the two theoretical approaches are discussed.

  5. Endorsement of formal leaders: an integrative model.

    PubMed

    Michener, H A; Lawler, E J

    1975-02-01

    This experiment develops an integrative, path-analytic model for the endorsement accorded formal leaders. The model contains four independent variables reflecting aspects of group structure (i.e., group success-failure, the payoff distribution, the degree of support by others members for the leader, and the vulnerability of the leader). Also included are two intervening variables reflecting perceptual processes (attributed competence and attributed fairness), and one dependent variable endorsement). The results indicate that endorsement is greater when the group's success is high, when the payoff distribution is flat rather than hierarchial, and when the leader is not vulnerable to removal from office. Other support had no significant impact on endorsement. Analyses further demonstrate that the effect of success-failure on endorsement is mediated by attributed competence, while the effect of the payoff distributed is mediated by attributed fairness. These results suggest that moral and task evaluations are distinct bases of endorsement. PMID:1123712

  6. Formalizing Linguistic Conventions for Conceptual Models

    NASA Astrophysics Data System (ADS)

    Becker, Jörg; Delfmann, Patrick; Herwig, Sebastian; Lis, Łukasz; Stein, Armin

    A precondition for the appropriate analysis of conceptual models is not only their syntactic correctness but also their semantic comparability. Assuring comparability is challenging especially when models are developed by different persons. Empirical studies show that such models can vary heavily, especially in model element naming, even if they express the same issue. In contrast to most ontology-driven approaches proposing the resolution of these differences ex-post, we introduce an approach that avoids naming differences in conceptual models already during modeling. Therefore we formalize naming conventions combining domain thesauri and phrase structures based on a lin-guistic grammar. This allows for guiding modelers automatically during the modeling process using standardized labels for model elements. Our approach is generic, making it applicable for any modeling language.

  7. MATRIX AND VECTOR SERVICES

    Energy Science and Technology Software Center (ESTSC)

    2001-10-18

    PETRA V2 provides matrix and vector services and the ability construct, query, and use matrix and vector objects that are used and computed by TRILINOS solvers. It provides all basic matr5ix and vector operations for solvers in TRILINOS.

  8. Matrix metalloproteinases and epileptogenesis.

    PubMed

    Ikonomidou, Chrysanthy

    2014-12-01

    Matrix metalloproteinases are vital drivers of synaptic remodeling in health and disease. It is suggested that at early stages of epileptogenesis, inhibition of matrix metalloproteinases may help ameliorate cell death, aberrant network rewiring, and neuroinflammation and prevent development of epilepsy. PMID:26567100

  9. Transfer function matrix

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1987-01-01

    Given a multivariable system, it is proved that the numerator matrix N(s) of the transfer function evaluated at any system pole either has unity rank or is a null matrix. It is also shown that N(s) evaluated at any transmission zero of the system has rank deficiency. Examples are given for illustration.

  10. Formal development of a clock synchronization circuit

    NASA Technical Reports Server (NTRS)

    Miner, Paul S.

    1995-01-01

    This talk presents the latest stage in formal development of a fault-tolerant clock synchronization circuit. The development spans from a high level specification of the required properties to a circuit realizing the core function of the system. An abstract description of an algorithm has been verified to satisfy the high-level properties using the mechanical verification system EHDM. This abstract description is recast as a behavioral specification input to the Digital Design Derivation system (DDD) developed at Indiana University. DDD provides a formal design algebra for developing correct digital hardware. Using DDD as the principle design environment, a core circuit implementing the clock synchronization algorithm was developed. The design process consisted of standard DDD transformations augmented with an ad hoc refinement justified using the Prototype Verification System (PVS) from SRI International. Subsequent to the above development, Wilfredo Torres-Pomales discovered an area-efficient realization of the same function. Establishing correctness of this optimization requires reasoning in arithmetic, so a general verification is outside the domain of both DDD transformations and model-checking techniques. DDD represents digital hardware by systems of mutually recursive stream equations. A collection of PVS theories was developed to aid in reasoning about DDD-style streams. These theories include a combinator for defining streams that satisfy stream equations, and a means for proving stream equivalence by exhibiting a stream bisimulation. DDD was used to isolate the sub-system involved in Torres-Pomales' optimization. The equivalence between the original design and the optimized verified was verified in PVS by exhibiting a suitable bisimulation. The verification depended upon type constraints on the input streams and made extensive use of the PVS type system. The dependent types in PVS provided a useful mechanism for defining an appropriate bisimulation.

  11. The Nuclear Energy Density Functional Formalism

    NASA Astrophysics Data System (ADS)

    Duguet, T.

    The present document focuses on the theoretical foundations of the nuclear energy density functional (EDF) method. As such, it does not aim at reviewing the status of the field, at covering all possible ramifications of the approach or at presenting recent achievements and applications. The objective is to provide a modern account of the nuclear EDF formalism that is at variance with traditional presentations that rely, at one point or another, on a Hamiltonian-based picture. The latter is not general enough to encompass what the nuclear EDF method represents as of today. Specifically, the traditional Hamiltonian-based picture does not allow one to grasp the difficulties associated with the fact that currently available parametrizations of the energy kernel E[g',g] at play in the method do not derive from a genuine Hamilton operator, would the latter be effective. The method is formulated from the outset through the most general multi-reference, i.e. beyond mean-field, implementation such that the single-reference, i.e. "mean-field", derives as a particular case. As such, a key point of the presentation provided here is to demonstrate that the multi-reference EDF method can indeed be formulated in a mathematically meaningful fashion even if E[g',g] does not derive from a genuine Hamilton operator. In particular, the restoration of symmetries can be entirely formulated without making any reference to a projected state, i.e. within a genuine EDF framework. However, and as is illustrated in the present document, a mathematically meaningful formulation does not guarantee that the formalism is sound from a physical standpoint. The price at which the latter can be enforced as well in the future is eventually alluded to.

  12. Time rate collision matrix

    SciTech Connect

    Stoenescu, M.L.; Smith, T.M.

    1980-02-01

    The collision integral terms in Boltzmann equation are reformulated numerically leading to the substitution of the multiple integrals with a multiplicative matrix of the two colliding species velocity distribution functions which varies with the differential collision cross section. A matrix of lower rank may be constructed when one of the distribution functions is specified, in which case the matrix elements represent kinetic transition probabilities in the velocity space and the multiplication of the time rate collision matrix with the unknown velocity distribution function expresses the time rate of change of the distribution. The collision matrix may be used to describe the time evolution of systems in nonequilibrium conditions, to evaluate the rate of momentum and energy transfer between given species, or to generate validity criteria for linearized kinetic equations.

  13. Grassmann matrix quantum mechanics

    NASA Astrophysics Data System (ADS)

    Anninos, Dionysios; Denef, Frederik; Monten, Ruben

    2016-04-01

    We explore quantum mechanical theories whose fundamental degrees of freedom are rectangular matrices with Grassmann valued matrix elements. We study particular models where the low energy sector can be described in terms of a bosonic Hermitian matrix quantum mechanics. We describe the classical curved phase space that emerges in the low energy sector. The phase space lives on a compact Kähler manifold parameterized by a complex matrix, of the type discovered some time ago by Berezin. The emergence of a semiclassical bosonic matrix quantum mechanics at low energies requires that the original Grassmann matrices be in the long rectangular limit. We discuss possible holographic interpretations of such matrix models which, by construction, are endowed with a finite dimensional Hilbert space.

  14. Unified Description of Electron-Nucleus Scattering within the Spectral Function Formalism

    NASA Astrophysics Data System (ADS)

    Rocco, Noemi; Lovato, Alessandro; Benhar, Omar

    2016-05-01

    The formalism based on factorization and nuclear spectral functions has been generalized to treat transition matrix elements involving two-nucleon currents, whose contribution to the nuclear electromagnetic response in the transverse channel is known to be significant. We report the results of calculations of the inclusive electron-carbon cross section, showing that the inclusion of processes involving two-nucleon currents appreciably improves the agreement between theory and data in the dip region, between the quasielastic and Δ -production peaks. The relation to approaches based on the independent particle of the nucleus and the implications for the analysis of flux-integrated neutrino-nucleus cross sections are discussed.

  15. Screw-matrix method in dynamics of multibody systems

    NASA Astrophysics Data System (ADS)

    Yanzhu, Liu

    1988-05-01

    In the present paper the concept of screw in classical mechanics is expressed in matrix form, in order to formulate the dynamical equations of the multibody systems. The mentioned method can retain the advantages of the screw theory and avoid the shortcomings of the dual number notation. Combining the screw-matrix method with the tool of graph theory in Roberson/Wittenberg formalism. We can expand the application of the screw theory to the general case of multibody systems. For a tree system, the dynamical equations for each j-th subsystem, composed of all the outboard bodies connected by j-th joint can be formulated without the constraint reaction forces in the joints. For a nontree system, the dynamical equations of subsystems and the kinematical consistency conditions of the joints can be derived using the loop matrix. The whole process of calculation is unified in matrix form. A three-segment manipulator is discussed as an example.

  16. The transfer matrix approach to circular graphene quantum dots

    NASA Astrophysics Data System (ADS)

    Chau Nguyen, H.; Nguyen, Nhung T. T.; Nguyen, V. Lien

    2016-07-01

    We adapt the transfer matrix (T-matrix) method originally designed for one-dimensional quantum mechanical problems to solve the circularly symmetric two-dimensional problem of graphene quantum dots. Similar to one-dimensional problems, we show that the generalized T-matrix contains rich information about the physical properties of these quantum dots. In particular, it is shown that the spectral equations for bound states as well as quasi-bound states of a circular graphene quantum dot and related quantities such as the local density of states and the scattering coefficients are all expressed exactly in terms of the T-matrix for the radial confinement potential. As an example, we use the developed formalism to analyse physical aspects of a graphene quantum dot induced by a trapezoidal radial potential. Among the obtained results, it is in particular suggested that the thermal fluctuations and electrostatic disorders may appear as an obstacle to controlling the valley polarization of Dirac electrons.

  17. Use of digital control theory state space formalism for feedback at SLC

    SciTech Connect

    Himel, T.; Hendrickson, L.; Rouse, F.; Shoaee, H.

    1991-05-01

    The algorithms used in the database-driven SLC fast-feedback system are based on the state space formalism of digital control theory. These are implemented as a set of matrix equations which use a Kalman filter to estimate a vector of states from a vector of measurements, and then apply a gain matrix to determine the actuator settings from the state vector. The matrices used in the calculation are derived offline using Linear Quadratic Gaussian minimization. For a given noise spectrum, this procedure minimizes the rms of the states (e.g., the position or energy of the beam). The offline program also allows simulation of the loop's response to arbitrary inputs, and calculates its frequency response. 3 refs., 3 figs.

  18. Hybrid matrix amplifier

    DOEpatents

    Martens, J.S.; Hietala, V.M.; Plut, T.A.

    1995-01-03

    The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N[times]M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise. 6 figures.

  19. Hybrid matrix amplifier

    DOEpatents

    Martens, Jon S.; Hietala, Vincent M.; Plut, Thomas A.

    1995-01-01

    The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N.times.M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise.

  20. Connecting Formal and Informal Learning Experiences

    NASA Astrophysics Data System (ADS)

    O'Mahony, Timothy Kieran

    The learning study reports on part of a larger project being lead by the author. In this dissertation I explore one goal of this project---to understand effects on student learning outcomes as a function of using different methods for connecting out-of-school experiential learning with formal school-based instruction. There is a long history of assuming that "experience is the best teacher"(e.g. Aristotle, 360 BC; Dewey, 1934; Kolb, 1997; Pliny, AD 77). As a practical geographer I endorsed that assumption throughout my teaching career, paying attention to local topography, physical features, and natural resources in the geographic hinterland. I was particularly interested in understanding the impact of the physical landscape on humankind, and reciprocally, noting humankind's widespread impressions on the natural world. Until I began this research project, I assumed that everyone else paid a similar attention to immediate surroundings. The work that I describe in this dissertation emerges out of a conviction that there are many degrees of truth to the idea that experience is a great teacher. Its effectiveness seems to depend on how one's "experience" is mediated, and how "learning from it" is defined. This motivated me to think about design principles for linking people's experiences to learning. I began to explore, experimentally, how I might enhance people's abilities to notice, represent, and discuss their experiences in order to better learn from them. This study investigated how different ways of connecting outdoor learning experiences to formal schooling impacts students' performance. I studied high-school students in outdoor settings as they engaged in evocative issues of learning pertaining to consequential everyday life encounters. Different kinds of "expert mediation" were introduced and tested as the students engaged in investigative activities around the science of dam removal and habitat restoration. I measured outcomes with the aid of pre- and

  1. Quiver matrix mechanics for IIB string theory II: generic dual tori, fractional matrix membrane and SL(2,Z) duality

    NASA Astrophysics Data System (ADS)

    Dai, Jian; Wu, Yong-Shi

    2005-02-01

    With the deconstruction technique, the geometric information of a torus can be encoded in a sequence of orbifolds. By studying the matrix theory on these orbifolds as quiver mechanics, we present a formulation that (de)constructs the torus of generic shape on which matrix theory is "compactified". The continuum limit of the quiver mechanics gives rise to a (1 + 2)-dimensional SYM. A hidden (fourth) dimension, that was introduced before in the matrix theory literature to argue for the electric-magnetic duality, can be easily identified in our formalism. We construct membrane wrapping states rigorously in terms of Dunford calculus in the context of matrix regularization. Unwanted degeneracy in the spectrum of the wrapping states is eliminated by using SL(2,Z) symmetry and the relations to the FD-string bound states. The dual IIB circle emerges in the continuum limit, constituting a critical evidence for IIB/M duality.

  2. Measurement matrix optimization method based on matrix orthogonal similarity transformation

    NASA Astrophysics Data System (ADS)

    Pan, Jinfeng

    2016-05-01

    Optimization of the measurement matrix is one of the important research aspects of compressive sensing theory. A measurement matrix optimization method is presented based on the orthogonal similarity transformation of the information operator's Gram matrix. In terms of the fact that the information operator's Gram matrix is a singular symmetric matrix, a simplified orthogonal similarity transformation is deduced, and thus the simplified diagonal matrix that is orthogonally similar to it is obtained. Then an approximation of the Gram matrix is obtained by letting all the nonzero diagonal entries of the simplified diagonal matrix equal their average value. Thus an optimized measurement matrix can be acquired according to its relationship with the information operator. Results of experiments show that the optimized measurement matrix compared to the random measurement matrix is less coherent with dictionaries. The relative signal recovery error also declines when the proposed measurement matrix is utilized.

  3. Formal verification of an oral messages algorithm for interactive consistency

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1992-01-01

    The formal specification and verification of an algorithm for Interactive Consistency based on the Oral Messages algorithm for Byzantine Agreement is described. We compare our treatment with that of Bevier and Young, who presented a formal specification and verification for a very similar algorithm. Unlike Bevier and Young, who observed that 'the invariant maintained in the recursive subcases of the algorithm is significantly more complicated than is suggested by the published proof' and who found its formal verification 'a fairly difficult exercise in mechanical theorem proving,' our treatment is very close to the previously published analysis of the algorithm, and our formal specification and verification are straightforward. This example illustrates how delicate choices in the formulation of the problem can have significant impact on the readability of its formal specification and on the tractability of its formal verification.

  4. The Lagrangian-Hamiltonian formalism for higher order field theories

    NASA Astrophysics Data System (ADS)

    Vitagliano, Luca

    2010-06-01

    We generalize the Lagrangian-Hamiltonian formalism of Skinner and Rusk to higher order field theories on fiber bundles. As a byproduct we solve the long standing problem of defining, in a coordinate free manner, a Hamiltonian formalism for higher order Lagrangian field theories. Namely, our formalism does only depend on the action functional and, therefore, unlike previously proposed ones, is free from any relevant ambiguity.

  5. Formal Techniques for Synchronized Fault-Tolerant Systems

    NASA Technical Reports Server (NTRS)

    DiVito, Ben L.; Butler, Ricky W.

    1992-01-01

    We present the formal verification of synchronizing aspects of the Reliable Computing Platform (RCP), a fault-tolerant computing system for digital flight control applications. The RCP uses NMR-style redundancy to mask faults and internal majority voting to purge the effects of transient faults. The system design has been formally specified and verified using the EHDM verification system. Our formalization is based on an extended state machine model incorporating snapshots of local processors clocks.

  6. Formal modeling and verification of fractional order linear systems.

    PubMed

    Zhao, Chunna; Shi, Likun; Guan, Yong; Li, Xiaojuan; Shi, Zhiping

    2016-05-01

    This paper presents a formalization of a fractional order linear system in a higher-order logic (HOL) theorem proving system. Based on the formalization of the Grünwald-Letnikov (GL) definition, we formally specify and verify the linear and superposition properties of fractional order systems. The proof provides a rigor and solid underpinnings for verifying concrete fractional order linear control systems. Our implementation in HOL demonstrates the effectiveness of our approach in practical applications. PMID:27126601

  7. A formalism for the calculus of variations with spinors

    NASA Astrophysics Data System (ADS)

    Bäckdahl, Thomas; Valiente Kroon, Juan A.

    2016-02-01

    We develop a frame and dyad gauge-independent formalism for the calculus of variations of functionals involving spinorial objects. As a part of this formalism, we define a modified variation operator which absorbs frame and spin dyad gauge terms. This formalism is applicable to both the standard spacetime (i.e., SL(2, ℂ)) 2-spinors as well as to space (i.e., SU(2, ℂ)) 2-spinors. We compute expressions for the variations of the connection and the curvature spinors.

  8. Gyrokinetic Formalism in Plasmas with Flows

    NASA Astrophysics Data System (ADS)

    Chiu, S. C.; Chan, V. S.; Lin-Liu, Y. R.; Chu, M. S.

    1998-11-01

    There is considerable theoretical and experimental evidence that plasma rotations in tokamaks can improve stability and confinement. Understanding the physics of rotating tokamak plasmas is thus of great importance for attaining high performance in reactors. Since present and future tokamaks are likely to have auxiliary heating such as radio frequency (RF) waves or neutral beam injection, it is of interest to understand the interaction of auxiliary heating with plasma rotation, and its consequences to transport and stability. In the past, rotation has not been self-consistently treated in auxiliary heating in that it is either ignored or ambipolarity is not self-consistently maintained. In this work, we describe a gyrokinetic formalism for RF in rotating plasmas which takes ambipolarity and equilibrium into account. A non-canonical guiding center Lagrangian for rotating plasma in a fluctuating field is obtained, and from which the gyrokinetic equation is deduced. Limiting the wave equations to the cyclotron frequency or below, quasilinear equations using an eikonal approximation are derived. Conservation laws for the system shall be discussed.

  9. Formal policies for flexible EHR security.

    PubMed

    Blobel, Bernd; Pharow, Peter

    2006-01-01

    State of the Art methodologies for establishing requirements and solutions to securing applications are based on narrative descriptions about the use of available system, sometimes also dedicated to system components. Even nowadays new developments to ruling application security services by the use of predicate logic suffer from being administered manually. Therefore, security and privacy requirements cannot be properly met resulting in restrictions and fears for allowing the use of sensitive data and functions. Because of the sensitivity of personal health information and especially of genetic data with its wider implications beyond the original subject of care, weaknesses in guaranteeing fine-grained security and privacy rules lead to less acceptance or even the avoidance of essential information transfer and use. To overcome the problem, security and privacy have to become properties of the architectural components of the respective health information system. Embedding security into the systems architecture allows for negotiating and enforcing any security and privacy services related to principals, their roles, their relationships, further contextual information as well as other regulations summarized in formally modeled policies. The paper introduces the evolving paradigm of the model-driven architecture, first time also comprehensively deployed for security and privacy services in bio-genetic and health information systems. PMID:17095829

  10. A Hamilton Jacobi formalism for thermodynamics

    NASA Astrophysics Data System (ADS)

    Rajeev, S. G.

    2008-09-01

    We show that classical thermodynamics has a formulation in terms of Hamilton-Jacobi theory, analogous to mechanics. Even though the thermodynamic variables come in conjugate pairs such as pressure/volume or temperature/entropy, the phase space is odd-dimensional. For a system with n thermodynamic degrees of freedom it is 2n+1-dimensional. The equations of state of a substance pick out an n-dimensional submanifold. A family of substances whose equations of state depend on n parameters define a hypersurface of co-dimension one. This can be described by the vanishing of a function which plays the role of a Hamiltonian. The ordinary differential equations (characteristic equations) defined by this function describe a dynamical system on the hypersurface. Its orbits can be used to reconstruct the equations of state. The 'time' variable associated to this dynamics is related to, but is not identical to, entropy. After developing this formalism on well-grounded systems such as the van der Waals gases and the Curie-Weiss magnets, we derive a Hamilton-Jacobi equation for black hole thermodynamics in General Relativity. The cosmological constant appears as a constant of integration in this picture.

  11. Fostering Formal Commutativity Knowledge with Approximate Arithmetic

    PubMed Central

    Hansen, Sonja Maria; Haider, Hilde; Eichler, Alexandra; Godau, Claudia; Frensch, Peter A.; Gaschler, Robert

    2015-01-01

    How can we enhance the understanding of abstract mathematical principles in elementary school? Different studies found out that nonsymbolic estimation could foster subsequent exact number processing and simple arithmetic. Taking the commutativity principle as a test case, we investigated if the approximate calculation of symbolic commutative quantities can also alter the access to procedural and conceptual knowledge of a more abstract arithmetic principle. Experiment 1 tested first graders who had not been instructed about commutativity in school yet. Approximate calculation with symbolic quantities positively influenced the use of commutativity-based shortcuts in formal arithmetic. We replicated this finding with older first graders (Experiment 2) and third graders (Experiment 3). Despite the positive effect of approximation on the spontaneous application of commutativity-based shortcuts in arithmetic problems, we found no comparable impact on the application of conceptual knowledge of the commutativity principle. Overall, our results show that the usage of a specific arithmetic principle can benefit from approximation. However, the findings also suggest that the correct use of certain procedures does not always imply conceptual understanding. Rather, the conceptual understanding of commutativity seems to lag behind procedural proficiency during elementary school. PMID:26560311

  12. Fostering Formal Commutativity Knowledge with Approximate Arithmetic.

    PubMed

    Hansen, Sonja Maria; Haider, Hilde; Eichler, Alexandra; Godau, Claudia; Frensch, Peter A; Gaschler, Robert

    2015-01-01

    How can we enhance the understanding of abstract mathematical principles in elementary school? Different studies found out that nonsymbolic estimation could foster subsequent exact number processing and simple arithmetic. Taking the commutativity principle as a test case, we investigated if the approximate calculation of symbolic commutative quantities can also alter the access to procedural and conceptual knowledge of a more abstract arithmetic principle. Experiment 1 tested first graders who had not been instructed about commutativity in school yet. Approximate calculation with symbolic quantities positively influenced the use of commutativity-based shortcuts in formal arithmetic. We replicated this finding with older first graders (Experiment 2) and third graders (Experiment 3). Despite the positive effect of approximation on the spontaneous application of commutativity-based shortcuts in arithmetic problems, we found no comparable impact on the application of conceptual knowledge of the commutativity principle. Overall, our results show that the usage of a specific arithmetic principle can benefit from approximation. However, the findings also suggest that the correct use of certain procedures does not always imply conceptual understanding. Rather, the conceptual understanding of commutativity seems to lag behind procedural proficiency during elementary school. PMID:26560311

  13. An enantioselective formal synthesis of montelukast sodium.

    PubMed

    Bollikonda, Satyanarayana; Mohanarangam, Saravanan; Jinna, Rajender Reddy; Kandirelli, Venkata Kiran Kumar; Makthala, Laxman; Sen, Saikat; Chaplin, David A; Lloyd, Richard C; Mahoney, Thomas; Dahanukar, Vilas Hareshwar; Oruganti, Srinivas; Fox, Martin E

    2015-04-17

    A formal synthesis of the antiasthma drug montelukast sodium is described, wherein the key chiral diol intermediate was accessed with greater convergence of the C-C bond-forming steps as compared to previous routes. Improved synthetic efficiency was achieved by deploying homogeneous metal-based catalysis in two pivotal steps. In the first, a tandem Mizoroki-Heck reaction and double-bond isomerization between a previously known allyl alcohol intermediate and a hindered 2-(2-halophenyl)propan-2-ol secured direct access to the 3-(2-(2-hydroxypropan-2-yl)phenyl)-1-phenylpropan-1-one moiety in the product. In the second step, asymmetric hydrogenation of the ketone functionality in the Mizoroki-Heck reaction product provided a convenient method to introduce the benzylic alcohol chiral center and obtain the desired chiral diol precursor of montelukast sodium. A detailed catalyst screening led to the identification of ((R)-Xyl-BINAP)((R,R)-DPEN)RuCl2 as a catalyst that afforded an enantioselectivity of 99% ee in the hydrogenation step on a multigram lab scale at a molar substrate:catalyst loading of 5000:1. PMID:25807000

  14. Formal Methods Applications in Air Transportation

    NASA Technical Reports Server (NTRS)

    Farley, Todd

    2009-01-01

    The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control system s aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Air traffic control modernization has long held the promise of a more efficient air transportation system. Part of NASA s current mission is to develop advanced automation and operational concepts that will expand the capacity of our national airspace system while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we ll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and the promise of formal methods going forward.

  15. Metal Matrix Composites

    SciTech Connect

    Hunt, Warren; Herling, Darrell R.

    2004-02-01

    Metal matrix composites have found selected application in areas that can cost-effectively capitalize on improvements in specific stiffness, specific strength, fatigue resistance, wear resistance, and coefficient of thermal expansion. Metal matrix composites comprise a relatively wide range of materials defined by the metal matrix, reinforcement type, and reinforcement geometry. In the area of the matrix, most metallic systems have been explored, including aluminum, beryllium, magnesium, titanium, iron, nickel, cobalt, and silver. However, aluminum is by far the most preferred. For reinforcements, the materials are typically ceramics, which provide a very beneficial combination of stiffness, strength, and relatively low density. Candidate reinforcement materials include SiC, Al2O3, B4C, TiC, TiB2, graphite, and a number of other ceramics. In addition, metallic materials such as tungsten and steel fibers have been considered.

  16. Pesticide-Exposure Matrix

    Cancer.gov

    The "Pesticide-exposure Matrix" was developed to help epidemiologists and other researchers identify the active ingredients to which people were likely exposed when their homes and gardens were treated for pests in past years.

  17. The Hill Interaction Matrix

    ERIC Educational Resources Information Center

    Hill, William Fawcett

    1971-01-01

    Leadership style, group composition, and group development are simultaneously quantified through the use of the matrix. It represents an attempt to objectify the art of group therapy. Comment by Richard C. Rank follows. (Author)

  18. Matrix computations in MACSYMA

    NASA Technical Reports Server (NTRS)

    Wang, P. S.

    1977-01-01

    Facilities built into MACSYMA for manipulating matrices with numeric or symbolic entries are described. Computations will be done exactly, keeping symbols as symbols. Topics discussed include how to form a matrix and create other matrices by transforming existing matrices within MACSYMA; arithmetic and other computation with matrices; and user control of computational processes through the use of optional variables. Two algorithms designed for sparse matrices are given. The computing times of several different ways to compute the determinant of a matrix are compared.

  19. A Formal Semantics for the SRI Hierarchical Program Design Methodology

    NASA Technical Reports Server (NTRS)

    Boyer, R. S.; Moore, J. S.

    1983-01-01

    A formal statement of what it means to use (a subset of) the methodology is presented. It is formally defined that some specified module exists and what it means to say that another module is paid correctly implemented on top of it. No attention is to motivation, either of the methodology or of the formal development of it. Concentration is entirely upon mathematical succinctness and precision. A discussion is presented of how to use certain INTERLISP programs which implement the formal definitions. Among these are a program which generates Floyd like verification conditions sufficient to imply the correctness of a module implementation.

  20. Optical coherency matrix tomography

    PubMed Central

    Kagalwala, Kumel H.; Kondakci, H. Esat; Abouraddy, Ayman F.; Saleh, Bahaa E. A.

    2015-01-01

    The coherence of an optical beam having multiple degrees of freedom (DoFs) is described by a coherency matrix G spanning these DoFs. This optical coherency matrix has not been measured in its entirety to date—even in the simplest case of two binary DoFs where G is a 4 × 4 matrix. We establish a methodical yet versatile approach—optical coherency matrix tomography—for reconstructing G that exploits the analogy between this problem in classical optics and that of tomographically reconstructing the density matrix associated with multipartite quantum states in quantum information science. Here G is reconstructed from a minimal set of linearly independent measurements, each a cascade of projective measurements for each DoF. We report the first experimental measurements of the 4 × 4 coherency matrix G associated with an electromagnetic beam in which polarization and a spatial DoF are relevant, ranging from the traditional two-point Young’s double slit to spatial parity and orbital angular momentum modes. PMID:26478452

  1. A formal model of interpersonal inference

    PubMed Central

    Moutoussis, Michael; Trujillo-Barreto, Nelson J.; El-Deredy, Wael; Dolan, Raymond J.; Friston, Karl J.

    2014-01-01

    Introduction: We propose that active Bayesian inference—a general framework for decision-making—can equally be applied to interpersonal exchanges. Social cognition, however, entails special challenges. We address these challenges through a novel formulation of a formal model and demonstrate its psychological significance. Method: We review relevant literature, especially with regards to interpersonal representations, formulate a mathematical model and present a simulation study. The model accommodates normative models from utility theory and places them within the broader setting of Bayesian inference. Crucially, we endow people's prior beliefs, into which utilities are absorbed, with preferences of self and others. The simulation illustrates the model's dynamics and furnishes elementary predictions of the theory. Results: (1) Because beliefs about self and others inform both the desirability and plausibility of outcomes, in this framework interpersonal representations become beliefs that have to be actively inferred. This inference, akin to “mentalizing” in the psychological literature, is based upon the outcomes of interpersonal exchanges. (2) We show how some well-known social-psychological phenomena (e.g., self-serving biases) can be explained in terms of active interpersonal inference. (3) Mentalizing naturally entails Bayesian updating of how people value social outcomes. Crucially this includes inference about one's own qualities and preferences. Conclusion: We inaugurate a Bayes optimal framework for modeling intersubject variability in mentalizing during interpersonal exchanges. Here, interpersonal representations are endowed with explicit functional and affective properties. We suggest the active inference framework lends itself to the study of psychiatric conditions where mentalizing is distorted. PMID:24723872

  2. A resonant scattering formalism for a fluid loaded elastic spherical near a planar boundary

    NASA Astrophysics Data System (ADS)

    Bishop, Garner

    2002-11-01

    Free field scattering from stationary fluid loaded elastic targets is well known and understood in terms of free field resonant scattering theory (RST), that it is given by the superposition of resonant and background components, and that the resonant components can be isolated by subtraction of an appropriate background. Backgrounds for isolating free field resonance spectra are well known. However, RST for scattering from a fluid loaded elastic target near a planar boundary where target scattering is accompanied by target-boundary scattering is less well known. A T-matrix formalism for plane wave scattering from rigid and soft spheres near a planar penetrable boundary is generalized to include a fluid loaded elastic spherical shell and RST is used to replace the free field T-matrix for the elastic shell that occurs within the formalism. It is shown that target-boundary scattering couples resonant and background components, couples modal resonances, and produces super-resonances. A background is introduced and it is shown that while background scattering is suppressed, coupled background and resonant scattering is not. Numerical results demonstrate some of the effects of target boundary scattering on the free field resonant spectrum of the shell as well as the dependence of target-boundary scattering on target.

  3. Order-disorder transition in the surface charge-density-wave phase of Cu(001)-c(4x4)-In

    SciTech Connect

    Hatta, S.; Okuyama, H.; Aruga, T.; Sakata, O.

    2005-08-15

    We have investigated the x-ray critical scattering from In/Cu(001) near the charge-density-wave phase transition. The critical exponents of the temperature dependence of the order parameter, the susceptibility, and the correlation length of the order parameter fluctuations are in agreement with those expected for a two-dimensional Ising-type phase transition. The lattice transition temperature, T{sub cl}=345 K, is 60 K lower than that for the electronic transition reported recently. The surface phase transition in this system is not well described by conventional weak- or strong-coupling theories, which assume a single characteristic energy gap. It is suggested that the electronic and lattice degrees of freedom on the surface are governed separately by two different energy gaps.

  4. Pedagogical Basis of DAS Formalism in Engineering Education

    ERIC Educational Resources Information Center

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-01-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other…

  5. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  6. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  7. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  8. Environmental Education in the Formal Sector of Education in Uganda.

    ERIC Educational Resources Information Center

    Mucunguzi, P.

    1995-01-01

    Provides a critical review of the present state of environmental education in the formal sector of education in Uganda. Recommends an improved approach to formal environmental education based on a multidisciplinary foundation that embraces the biophysical environment, people, culture, politics, and socioeconomic systems. (LZ)

  9. Automatically Grading Customer Confidence in a Formal Specification.

    ERIC Educational Resources Information Center

    Shukur, Zarina; Burke, Edmund; Foxley, Eric

    1999-01-01

    Describes an automatic grading system for a formal methods computer science course that is able to evaluate a formal specification written in the Z language. Quality is measured by considering first, specification correctness (syntax, semantics, and satisfaction of customer requirements), and second, specification maintainability (comparison of…

  10. The Archival Photograph and Its Meaning: Formalisms for Modeling Images

    ERIC Educational Resources Information Center

    Benson, Allen C.

    2009-01-01

    This article explores ontological principles and their potential applications in the formal description of archival photographs. Current archival descriptive practices are reviewed and the larger question is addressed: do archivists who are engaged in describing photographs need a more formalized system of representation, or do existing encoding…

  11. Recognising Non-Formal and Informal Learning: An Open Challenge

    ERIC Educational Resources Information Center

    Perulli, Elisabetta

    2009-01-01

    The social-institutional endorsement towards the perspective of recognising and enhancing learning acquired outside the formal education and training contexts (non-formal and informal learning), has been gaining strength and has entered policy agendas throughout Europe, but also in other major non-European countries. Nevertheless there are still…

  12. Toward a mathematical formalism of performance, task difficulty, and activation

    NASA Technical Reports Server (NTRS)

    Samaras, George M.

    1988-01-01

    The rudiments of a mathematical formalism for handling operational, physiological, and psychological concepts are developed for use by the man-machine system design engineer. The formalism provides a framework for developing a structured, systematic approach to the interface design problem, using existing mathematical tools, and simplifying the problem of telling a machine how to measure and use performance.

  13. Integrating Formal and Grounded Representations in Combinatorics Learning

    ERIC Educational Resources Information Center

    Braithwaite, David W.; Goldstone, Robert L.

    2013-01-01

    The terms "concreteness fading" and "progressive formalization" have been used to describe instructional approaches to science and mathematics that use grounded representations to introduce concepts and later transition to more formal representations of the same concepts. There are both theoretical and empirical reasons to…

  14. 18 CFR 5.14 - Formal study dispute resolution process.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Formal study dispute resolution process. 5.14 Section 5.14 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT INTEGRATED LICENSE APPLICATION PROCESS § 5.14 Formal study...

  15. 7 CFR 18.5 - Formal complaint procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Formal complaint procedure. 18.5 Section 18.5... EXTENSION SERVICES § 18.5 Formal complaint procedure. A procedure shall be provided for the filing of a... origin, sex, or religion. (b) Time limits for processing. The procedure will include time limits for...

  16. 7 CFR 18.5 - Formal complaint procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Formal complaint procedure. 18.5 Section 18.5... EXTENSION SERVICES § 18.5 Formal complaint procedure. A procedure shall be provided for the filing of a... origin, sex, or religion. (b) Time limits for processing. The procedure will include time limits for...

  17. 7 CFR 18.5 - Formal complaint procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Formal complaint procedure. 18.5 Section 18.5... EXTENSION SERVICES § 18.5 Formal complaint procedure. A procedure shall be provided for the filing of a... origin, sex, or religion. (b) Time limits for processing. The procedure will include time limits for...

  18. 7 CFR 18.5 - Formal complaint procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Formal complaint procedure. 18.5 Section 18.5... EXTENSION SERVICES § 18.5 Formal complaint procedure. A procedure shall be provided for the filing of a... origin, sex, or religion. (b) Time limits for processing. The procedure will include time limits for...

  19. 7 CFR 18.5 - Formal complaint procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Formal complaint procedure. 18.5 Section 18.5... EXTENSION SERVICES § 18.5 Formal complaint procedure. A procedure shall be provided for the filing of a... origin, sex, or religion. (b) Time limits for processing. The procedure will include time limits for...

  20. 17 CFR 230.470 - Formal requirements for amendments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Formal requirements for amendments. 230.470 Section 230.470 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 Amendments; Withdrawals § 230.470 Formal requirements for amendments. Except for...

  1. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  2. Catalytic Asymmetric Formal Total Synthesis of (-)-Triptophenolide and (+)-Triptolide.

    PubMed

    Xu, Wen-Dan; Li, Liang-Qun; Li, Ming-Ming; Geng, Hui-Chun; Qin, Hong-Bo

    2016-06-01

    Catalytic asymmetric formal synthesis of (-)-Triptophenolide and (+)-Triptolide have been achieved. Key reaction involves Palladium catalyzed asymmetric conjugate addition of aryl boronic acid to 3-methyl cyclohexe-1-none to form quaternary carbon. Claisen rearrangement and subsequent aldol reaction furnished trans-decaline key intermediate, which assured a formal total synthesis of (-)-Triptophenolide and (+)-Triptolide. PMID:27095015

  3. Academic Achievement and Formal Thought in Engineering Students

    ERIC Educational Resources Information Center

    Vazquez, Stella Maris; de Anglat, Hilda Difabio

    2009-01-01

    Introduction: Research on university-level academic performance has significantly linked failure and dropping out to formal reasoning deficiency. We have not found any papers on formal thought in Argentine university students, in spite of the obvious shortcomings observed in the classrooms. Thus, the main objective of this paper was exploring the…

  4. Blending Formal and Informal Learning Networks for Online Learning

    ERIC Educational Resources Information Center

    Czerkawski, Betül C.

    2016-01-01

    With the emergence of social software and the advance of web-based technologies, online learning networks provide invaluable opportunities for learning, whether formal or informal. Unlike top-down, instructor-centered, and carefully planned formal learning settings, informal learning networks offer more bottom-up, student-centered participatory…

  5. 7 CFR 1726.201 - Formal competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., as described in 7 CFR 1726.201, were followed in awarding this contract.” The certification executed... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its...

  6. 7 CFR 1726.201 - Formal competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., as described in 7 CFR 1726.201, were followed in awarding this contract.” The certification executed... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its...

  7. 7 CFR 1726.201 - Formal competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., as described in 7 CFR 1726.201, were followed in awarding this contract.” The certification executed... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... formal competitive bidding: (a) Selection of qualified bidders. The borrower (acting through its...

  8. Enhancing Formal E-Learning with Edutainment on Social Networks

    ERIC Educational Resources Information Center

    Labus, A.; Despotovic-Zrakic, M.; Radenkovic, B.; Bogdanovic, Z.; Radenkovic, M.

    2015-01-01

    This paper reports on the investigation of the possibilities of enhancing the formal e-learning process by harnessing the potential of informal game-based learning on social networks. The goal of the research is to improve the outcomes of the formal learning process through the design and implementation of an educational game on a social network…

  9. I, Pronoun: A Study of Formality in Online Content

    ERIC Educational Resources Information Center

    Thayer, Alexander; Evans, Mary B.; McBride, Alicia A.; Queen, Matt; Spyridakis, Jan H.

    2010-01-01

    This article presents the results of a study that investigated readers' perceptions of tone formality in online text passages. The study found that readers perceived text passages to be less formal when they contained personal pronouns, active voice verbs, informal punctuation, or verb contractions. The study reveals that professional…

  10. 49 CFR 1111.1 - Content of formal complaints; joinder.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Content of formal complaints; joinder. 1111.1 Section 1111.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE COMPLAINT AND INVESTIGATION PROCEDURES § 1111.1 Content of formal complaints; joinder....

  11. 7 CFR 3017.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Are debarment proceedings formal? 3017.835 Section... FINANCIAL OFFICER, DEPARTMENT OF AGRICULTURE GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 3017.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair...

  12. 29 CFR 1471.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Are debarment proceedings formal? 1471.835 Section 1471.835... GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 1471.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair and informal manner. The debarring official may...

  13. 31 CFR 19.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Are debarment proceedings formal? 19.835 Section 19.835 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 19.835 Are debarment proceedings formal? (a)...

  14. 21 CFR 1404.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Are debarment proceedings formal? 1404.835 Section 1404.835 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 1404.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted...

  15. 2 CFR 180.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2 Grants and Agreements 1 2013-01-01 2013-01-01 false Are debarment proceedings formal? 180.835... REQUIREMENTS OMB GUIDELINES TO AGENCIES ON GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 180.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair...

  16. 31 CFR 19.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Are debarment proceedings formal? 19.835 Section 19.835 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 19.835 Are debarment proceedings formal? (a)...

  17. 5 CFR 919.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Are debarment proceedings formal? 919.835... REGULATIONS (CONTINUED) GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 919.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair and informal manner....

  18. 29 CFR 98.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Are debarment proceedings formal? 98.835 Section 98.835 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 98.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair...

  19. 2 CFR 180.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Are debarment proceedings formal? 180.835... TO AGENCIES ON GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 180.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair and informal manner....

  20. 2 CFR 180.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2 Grants and Agreements 1 2011-01-01 2011-01-01 false Are debarment proceedings formal? 180.835... AGENCIES ON GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 180.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair and informal manner. The...

  1. 31 CFR 19.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Are debarment proceedings formal? 19.835 Section 19.835 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 19.835 Are debarment proceedings formal? (a)...

  2. 5 CFR 919.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Are debarment proceedings formal? 919.835... REGULATIONS (CONTINUED) GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 919.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted in a fair and informal manner....

  3. Home Education Transitions with Formal Schooling: Student Perspectives

    ERIC Educational Resources Information Center

    Jackson, Glenda

    2007-01-01

    Home education is a well established phenomenon in Australia but little is known about the movement of students between home schooling and formal education and how students view and handle the transitions. A sociocultural theoretical framework has been used to explore student perceptions of their transition experiences between formal education and…

  4. How Online Journalists Learn within a Non-Formal Context

    ERIC Educational Resources Information Center

    Kronstad, Morten; Eide, Martin

    2015-01-01

    Purpose: The purpose of this paper is to contribute to the understanding of workplace learning, with a focus on the non-formal learning that takes place among online journalists. The focus of this article is journalists working in an online newspaper and their experiences with workplace and non-formal learning, centering on framework conditions…

  5. Formal or Nonformal Education? Entrepreneurial Women in Ghana.

    ERIC Educational Resources Information Center

    Robertson, Claire C.

    1984-01-01

    Ghanian women have a long history as traders. In early 1978, 42 Central Accra schoolgirls and 42 girls engaged in selling were surveyed to determine the relationship of formal education to marketing skills. Formal education was not significantly helpful in promoting schoolgirls' trading knowledge nor in providing skills likely to land them jobs.…

  6. On the Equivalence of Formal Grammars and Machines.

    ERIC Educational Resources Information Center

    Lund, Bruce

    1991-01-01

    Explores concepts of formal language and automata theory underlying computational linguistics. A computational formalism is described known as a "logic grammar," with which computational systems process linguistic data, with examples in declarative and procedural semantics and definite clause grammars. (13 references) (CB)

  7. Refinement of the Robert-Bonamy Formalism: Taking into Account Contributions from Line Coupling

    NASA Astrophysics Data System (ADS)

    Ma, Q.; Boulet, C.; Tipping, R. H.

    2014-06-01

    The Robert-Bonamy (RB) formalism has been used to calculate half-widths and shifts adopted in HITRAN for years. Besides its success, it contains several approximations whose applicability has not been thoroughly justified. One of them is an assumption that lines of interest are well separated. When these authors developed the formalism, they have relied on this assumption twice. First, in calculating the spectral density F(ω), they have only considered the diagonal matrix elements of the relaxation operator. Due to this simplification, effects from line mixing are ignored. Secondly, when they applied the linked cluster theorem to remove the cut-off appearing in Anderson's theory, they have assumed that the operator (-iS1 - S2) is diagonal within the linespace so that matrix elements of the operator exp(- iS1 - S2) can be replaced by the exponential of the matrix elements of (- iS1 - S2). With this replacement, effects on calculated half-widths and shifts from the line coupling are also ignored. Although both these two simplifications relied on the same approximation, their validity criteria are completely different and the latter is more stringent than the former. As a result, in many cases where the line mixing becomes negligible, significant effects from the line coupling have been completely missed. Recently, by abandoning the second simplification and accurately evaluating the matrix elements of exp(- iS1 - S2), we have refined the RB formalism such that the line coupling can be taken into account. Our numerical calculations for the Raman Q lines of auto-perturbed N2, and also the Raman Q lines and the infrared P and R lines of C2H2 in a N2 bath have demonstrated that effects on calculated half-widths from the line coupling are important. In comparison with values derived without the line coupling, new calculated values for these lines are significantly reduced and become closer to measurements.1 With respect to the H2O molecule immersed in a

  8. Matrix elements and duality for type 2 unitary representations of the Lie superalgebra gl(m|n)

    NASA Astrophysics Data System (ADS)

    Werry, Jason L.; Gould, Mark D.; Isaac, Phillip S.

    2015-12-01

    The characteristic identity formalism discussed in our recent articles is further utilized to derive matrix elements of type 2 unitary irreducible gl(m|n) modules. In particular, we give matrix element formulae for all gl(m|n) generators, including the non-elementary generators, together with their phases on finite dimensional type 2 unitary irreducible representations which include the contravariant tensor representations and an additional class of essentially typical representations. Remarkably, we find that the type 2 unitary matrix element equations coincide with the type 1 unitary matrix element equations for non-vanishing matrix elements up to a phase.

  9. Matrix elements and duality for type 2 unitary representations of the Lie superalgebra gl(m|n)

    SciTech Connect

    Werry, Jason L.; Gould, Mark D.; Isaac, Phillip S.

    2015-12-15

    The characteristic identity formalism discussed in our recent articles is further utilized to derive matrix elements of type 2 unitary irreducible gl(m|n) modules. In particular, we give matrix element formulae for all gl(m|n) generators, including the non-elementary generators, together with their phases on finite dimensional type 2 unitary irreducible representations which include the contravariant tensor representations and an additional class of essentially typical representations. Remarkably, we find that the type 2 unitary matrix element equations coincide with the type 1 unitary matrix element equations for non-vanishing matrix elements up to a phase.

  10. Tendon Functional Extracellular Matrix

    PubMed Central

    Screen, H.R.C.; Birk, D.E.; Kadler, K.E.; Ramirez, F; Young, M.F.

    2015-01-01

    This article is one of a series, summarising views expressed at the Orthopaedic Research Society New Frontiers in Tendon Research Conference. This particular article reviews the three workshops held under the “Functional Extracellular Matrix” stream. The workshops focused on the roles of the tendon extracellular matrix, such as performing the mechanical functions of tendon, creating the local cell environment and providing cellular cues. Tendon is a complex network of matrix and cells, and its biological functions are influenced by widely-varying extrinsic and intrinsic factors such as age, nutrition, exercise levels and biomechanics. Consequently, tendon adapts dynamically during development, ageing and injury. The workshop discussions identified research directions associated with understanding cell-matrix interactions to be of prime importance for developing novel strategies to target tendon healing or repair. PMID:25640030

  11. Matrix interdiction problem

    SciTech Connect

    Pan, Feng; Kasiviswanathan, Shiva

    2010-01-01

    In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.

  12. Identification of an iridium-containing compound with a formal oxidation state of IX.

    PubMed

    Wang, Guanjun; Zhou, Mingfei; Goettel, James T; Schrobilgen, Gary J; Su, Jing; Li, Jun; Schlöder, Tobias; Riedel, Sebastian

    2014-10-23

    One of the most important classifications in chemistry and within the periodic table is the concept of formal oxidation states. The preparation and characterization of compounds containing elements with unusual oxidation states is of great interest to chemists. The highest experimentally known formal oxidation state of any chemical element is at present VIII, although higher oxidation states have been postulated. Compounds with oxidation state VIII include several xenon compounds (for example XeO4 and XeO3F2) and the well-characterized species RuO4 and OsO4 (refs 2-4). Iridium, which has nine valence electrons, is predicted to have the greatest chance of being oxidized beyond the VIII oxidation state. In recent matrix-isolation experiments, the IrO4 molecule was characterized as an isolated molecule in rare-gas matrices. The valence electron configuration of iridium in IrO4 is 5d(1), with a formal oxidation state of VIII. Removal of the remaining d electron from IrO4 would lead to the iridium tetroxide cation ([IrO4](+)), which was recently predicted to be stable and in which iridium is in a formal oxidation state of IX. There has been some speculation about the formation of [IrO4](+) species, but these experimental observations have not been structurally confirmed. Here we report the formation of [IrO4](+) and its identification by infrared photodissociation spectroscopy. Quantum-chemical calculations were carried out at the highest level of theory that is available today, and predict that the iridium tetroxide cation, with a Td-symmetrical structure and a d(0) electron configuration, is the most stable of all possible [IrO4](+) isomers. PMID:25341786

  13. Identification of an iridium-containing compound with a formal oxidation state of IX

    NASA Astrophysics Data System (ADS)

    Wang, Guanjun; Zhou, Mingfei; Goettel, James T.; Schrobilgen, Gary J.; Su, Jing; Li, Jun; Schlöder, Tobias; Riedel, Sebastian

    2014-10-01

    One of the most important classifications in chemistry and within the periodic table is the concept of formal oxidation states. The preparation and characterization of compounds containing elements with unusual oxidation states is of great interest to chemists. The highest experimentally known formal oxidation state of any chemical element is at present VIII, although higher oxidation states have been postulated. Compounds with oxidation state VIII include several xenon compounds (for example XeO4 and XeO3F2) and the well-characterized species RuO4 and OsO4 (refs 2, 3, 4). Iridium, which has nine valence electrons, is predicted to have the greatest chance of being oxidized beyond the VIII oxidation state. In recent matrix-isolation experiments, the IrO4 molecule was characterized as an isolated molecule in rare-gas matrices. The valence electron configuration of iridium in IrO4 is 5d1, with a formal oxidation state of VIII. Removal of the remaining d electron from IrO4 would lead to the iridium tetroxide cation ([IrO4]+), which was recently predicted to be stable and in which iridium is in a formal oxidation state of IX. There has been some speculation about the formation of [IrO4]+ species, but these experimental observations have not been structurally confirmed. Here we report the formation of [IrO4]+ and its identification by infrared photodissociation spectroscopy. Quantum-chemical calculations were carried out at the highest level of theory that is available today, and predict that the iridium tetroxide cation, with a Td-symmetrical structure and a d0 electron configuration, is the most stable of all possible [IrO4]+ isomers.

  14. Complex matrix model duality

    SciTech Connect

    Brown, T. W.

    2011-04-15

    The same complex matrix model calculates both tachyon scattering for the c=1 noncritical string at the self-dual radius and certain correlation functions of operators which preserve half the supersymmetry in N=4 super-Yang-Mills theory. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich-Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces.

  15. New Technologies and Learning Environments: A Perspective from Formal and Non-Formal Education in Baja California, Mexico

    ERIC Educational Resources Information Center

    Zamora, Julieta Lopez; Reynaga, Francisco Javier Arriaga

    2010-01-01

    This paper presents results of two research works, the first approaches non-formal education and the second addresses formal education. In both studies in-depth interview techniques were used. There were some points of convergence between them on aspects such as the implementation of learning environments and the integration of ICT. The interview…

  16. Matrixed business support comparison study.

    SciTech Connect

    Parsons, Josh D.

    2004-11-01

    The Matrixed Business Support Comparison Study reviewed the current matrixed Chief Financial Officer (CFO) division staff models at Sandia National Laboratories. There were two primary drivers of this analysis: (1) the increasing number of financial staff matrixed to mission customers and (2) the desire to further understand the matrix process and the opportunities and challenges it creates.

  17. New Representations of the Perturbative S Matrix.

    PubMed

    Baadsgaard, Christian; Bjerrum-Bohr, N E J; Bourjaily, Jacob L; Caron-Huot, Simon; Damgaard, Poul H; Feng, Bo

    2016-02-12

    We propose a new framework to represent the perturbative S matrix which is well defined for all quantum field theories of massless particles, constructed from tree-level amplitudes and integrable term by term. This representation is derived from the Feynman expansion through a series of partial fraction identities, discarding terms that vanish upon integration. Loop integrands are expressed in terms of "Q-cuts" that involve both off-shell and on-shell loop momenta, defined with a precise contour prescription that can be evaluated by ordinary methods. This framework implies recent results found in the scattering equation formalism at one loop, and it has a natural extension to all orders--even nonplanar theories without well-defined forward limits or good ultraviolet behavior. PMID:26918978

  18. Matrix Synthesis and Characterization

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The role of NASA in the area of composite material synthesis; evaluation techniques; prediction analysis techniques; solvent-resistant tough composite matrix; resistance to paint strippers; acceptable processing temperature and pressure for thermoplastics; and the role of computer modeling and fiber interface improvement were discussed.

  19. The Acrosomal Matrix.

    PubMed

    Foster, James A; Gerton, George L

    2016-01-01

    The acrosome, a single exocytotic vesicle on the head of sperm, has an essential role in fertilization, but the exact mechanisms by which it facilitates sperm-egg interactions remain unresolved. The acrosome contains dozens of secretory proteins that are packaged into the forming structure during spermatogenesis; many of these proteins are localized into specific topographical areas of the acrosome, while others are more diffusely distributed. Acrosomal proteins can also be biochemically classified as components of the acrosomal matrix, a large, relatively insoluble complex, or as soluble proteins. This review focuses on recent findings using genetically modified mice (gene knockouts and transgenic "green acrosome" mice) to study the effects of eliminating acrosomal matrix-associated proteins on sperm structure and function. Some gene knockouts produce infertile phenotypes with obviously missing, specific activities that affect acrosome biogenesis during spermatogenesis or interfere with acrosome function in mature sperm. Mutations that delete some components produce fertile phenotypes with subtler effects that provide useful insights into acrosomal matrix function in fertilization. In general, these studies enable the reassessment of paradigms to explain acrosome formation and function and provide novel, objective insights into the roles of acrosomal matrix proteins in fertilization. The use of genetically engineered mouse models has yielded new mechanistic information that complements recent, important in vivo imaging studies. PMID:27194348

  20. Matrix Embedded Organic Synthesis

    NASA Astrophysics Data System (ADS)

    Kamakolanu, U. G.; Freund, F. T.

    2016-05-01

    In the matrix of minerals such as olivine, a redox reaction of the low-z elements occurs. Oxygen is oxidized to the peroxy state while the low-Z-elements become chemically reduced. We assign them a formula [CxHyOzNiSj]n– and call them proto-organics.

  1. Constructing the matrix

    NASA Astrophysics Data System (ADS)

    Elliott, John

    2012-09-01

    As part of our 'toolkit' for analysing an extraterrestrial signal, the facility for calculating structural affinity to known phenomena must be part of our core capabilities. Without such a resource, we risk compromising our potential for detection and decipherment or at least causing significant delay in the process. To create such a repository for assessing structural affinity, all known systems (language parameters) need to be structurally analysed to 'place' their 'system' within a relational communication matrix. This will need to include all known variants of language structure, whether 'living' (in current use) or ancient; this must also include endeavours to incorporate yet undeciphered scripts and non-human communication, to provide as complete a picture as possible. In creating such a relational matrix, post-detection decipherment will be assisted by a structural 'map' that will have the potential for 'placing' an alien communication with its nearest known 'neighbour', to assist subsequent categorisation of basic parameters as a precursor to decipherment. 'Universal' attributes and behavioural characteristics of known communication structure will form a range of templates (Elliott, 2001 [1] and Elliott et al., 2002 [2]), to support and optimise our attempt at categorising and deciphering the content of an extraterrestrial signal. Detection of the hierarchical layers, which comprise intelligent, complex communication, will then form a matrix of calculations that will ultimately score affinity through a relational matrix of structural comparison. In this paper we develop the rationales and demonstrate functionality with initial test results.

  2. A review of research on formal reasoning and science teaching

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.

    A central purpose of education is to improve students' reasoning abilities. The present review examines research in developmental psychology and science education that has attempted to assess the validity of Piaget's theory of formal thought and its relation to educational practice. Should a central objective of schools be to help students become formal thinkers? To answer this question research has focused on the following subordinate questions: (1) What role does biological maturation play in the development of formal reasoning? (2) Are Piaget's formal tasks reliable and valid? (3) Does formal reasoning constitute a unified and general mode of intellectual functioning? (4) How does the presence or absence of formal reasoning affect school achievement? (5) Can formal reasoning be taught? (6) What is the structural or functional nature of advanced reasoning? The general conclusion drawn is that although Piaget's work and that which has sprung from it leaves a number of unresolved theoretical and methodological problems, it provides an important background from which to make substantial progress toward a most significant educational objective.All our dignity lies in thought. By thought we must elevate ourselves, not by space and time which we can not fill. Let us endeavor then to think well; therein lies the principle of morality. Blaise Pascal 1623-1662.

  3. Correlates of formal reasoning: Content and problem effects

    NASA Astrophysics Data System (ADS)

    Linn, Marcia C.; Pulos, Steven; Gans, Adrienne

    Piaget's structural theory of formal thought suggests that a general construct of formal reasoning exists. The content of the task and type of problem employed are often ignored in Piagetian based studies but are important for generalizing findings to other studies and to educational problems. The study reported here examines content and problem effects of formal thought in 13-year-old adolescents. Specifically, three controlling variables tasks with different content and two question type tests (analysis and controlling questions) were administered to 120 seventh graders. Ability measures and personality dimensions associated with formal reasoning in the literature are used to clarify what formal reasoning is and how content and problem type are involved in formal reasoning. Significant main effects were found for problem and content effects (p = 0.001), and a significant interaction was found between the two (p = 0.001). Across the three tasks general ability, field dependency, and locus of control were consistently and significantly related to the controlling questions. However, only measures of field dependency were related to the analysis questions. Combinations of ability and personality factors were found to be uniquely related to each task, within each question type. Results have implications for a theory of formal thought and the teaching of the controlling variables strategy.

  4. Matrix De Rham Complex and Quantum A-infinity algebras

    NASA Astrophysics Data System (ADS)

    Barannikov, S.

    2014-04-01

    I establish the relation of the non-commutative BV-formalism with super-invariant matrix integration. In particular, the non-commutative BV-equation, defining the quantum A ∞-algebras, introduced in Barannikov (Modular operads and non-commutative Batalin-Vilkovisky geometry. IMRN, vol. 2007, rnm075. Max Planck Institute for Mathematics 2006-48, 2007), is represented via de Rham differential acting on the supermatrix spaces related with Bernstein-Leites simple associative algebras with odd trace q( N), and gl( N| N). I also show that the matrix Lagrangians from Barannikov (Noncommutative Batalin-Vilkovisky geometry and matrix integrals. Isaac Newton Institute for Mathematical Sciences, Cambridge University, 2006) are represented by equivariantly closed differential forms.

  5. Conductance matrix of multiterminal semiconductor devices with edge channels

    SciTech Connect

    Danilovskii, E. Yu. Bagraev, N. T.

    2014-12-15

    A method for determining the conductance matrix of multiterminal semiconductor structures with edge channels is proposed. The method is based on the solution of a system of linear algebraic equations based on Kirchhoff equations, made up of potential differences U{sub ij} measured at stabilized currents I{sub kl}, where i, j, k, l are terminal numbers. The matrix obtained by solving the system of equations completely describes the structure under study, reflecting its configuration and homogeneity. This method can find wide application when using the known Landauer-Buttiker formalism to analyze carrier transport in the quantum Hall effect and quantum spin Hall effect modes. Within the proposed method, the contribution of the contact area resistances R{sub c} to the formation of conductance matrix elements is taken into account. The possibilities of practical application of the results obtained in developing analog cryptographic devices are considered.

  6. Proceedings of the Second NASA Formal Methods Symposium

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar (Editor)

    2010-01-01

    This publication contains the proceedings of the Second NASA Formal Methods Symposium sponsored by the National Aeronautics and Space Administration and held in Washington D.C. April 13-15, 2010. Topics covered include: Decision Engines for Software Analysis using Satisfiability Modulo Theories Solvers; Verification and Validation of Flight-Critical Systems; Formal Methods at Intel -- An Overview; Automatic Review of Abstract State Machines by Meta Property Verification; Hardware-independent Proofs of Numerical Programs; Slice-based Formal Specification Measures -- Mapping Coupling and Cohesion Measures to Formal Z; How Formal Methods Impels Discovery: A Short History of an Air Traffic Management Project; A Machine-Checked Proof of A State-Space Construction Algorithm; Automated Assume-Guarantee Reasoning for Omega-Regular Systems and Specifications; Modeling Regular Replacement for String Constraint Solving; Using Integer Clocks to Verify the Timing-Sync Sensor Network Protocol; Can Regulatory Bodies Expect Efficient Help from Formal Methods?; Synthesis of Greedy Algorithms Using Dominance Relations; A New Method for Incremental Testing of Finite State Machines; Verification of Faulty Message Passing Systems with Continuous State Space in PVS; Phase Two Feasibility Study for Software Safety Requirements Analysis Using Model Checking; A Prototype Embedding of Bluespec System Verilog in the PVS Theorem Prover; SimCheck: An Expressive Type System for Simulink; Coverage Metrics for Requirements-Based Testing: Evaluation of Effectiveness; Software Model Checking of ARINC-653 Flight Code with MCP; Evaluation of a Guideline by Formal Modelling of Cruise Control System in Event-B; Formal Verification of Large Software Systems; Symbolic Computation of Strongly Connected Components Using Saturation; Towards the Formal Verification of a Distributed Real-Time Automotive System; Slicing AADL Specifications for Model Checking; Model Checking with Edge-valued Decision Diagrams

  7. Formal Specification of the OpenMP Memory Model

    SciTech Connect

    Bronevetsky, G; de Supinski, B

    2006-12-19

    OpenMP [2] is an important API for shared memory programming, combining shared memory's potential for performance with a simple programming interface. Unfortunately, OpenMP lacks a critical tool for demonstrating whether programs are correct: a formal memory model. Instead, the current official definition of the OpenMP memory model (the OpenMP 2.5 specification [2]) is in terms of informal prose. As a result, it is impossible to verify OpenMP applications formally since the prose does not provide a formal consistency model that precisely describes how reads and writes on different threads interact. We expand on our previous work that focused on the formal verification of OpenMP programs through a formal memory model [?]. As in that work, our formalization, which is derived from the existing prose model [2], provides a two-step process to verify whether an observed OpenMP execution is conformant. This paper extends the model to cover the entire specification. In addition to this formalization, our contributions include a discussion of ambiguities in the current prose-based memory model description. Although our formal model may not capture the current informal memory model perfectly, in part due to these ambiguities, our model reflects our understanding of the informal model's intent. We conclude with several examples that may indicate areas of the OpenMP memory model that need further refinement, however it is specified. Our goal is to motivate the OpenMP community to adopt those refinements eventually, ideally through a formal model, in later OpenMP specifications.

  8. Multisymplectic Lagrangian and Hamiltonian Formalisms of Classical Field Theories

    NASA Astrophysics Data System (ADS)

    Román-Roy, Narciso

    2009-11-01

    This review paper is devoted to presenting the standard multisymplectic formulation for describing geometrically classical field theories, both the regular and singular cases. First, the main features of the Lagrangian formalism are revisited and, second, the Hamiltonian formalism is constructed using Hamiltonian sections. In both cases, the variational principles leading to the Euler-Lagrange and the Hamilton-De Donder-Weyl equations, respectively, are stated, and these field equations are given in different but equivalent geometrical ways in each formalism. Finally, both are unified in a new formulation (which has been developed in the last years), following the original ideas of Rusk and Skinner for mechanical systems.

  9. A Formalization of HIPAA for a Medical Messaging System

    NASA Astrophysics Data System (ADS)

    Lam, Peifung E.; Mitchell, John C.; Sundaram, Sharada

    The complexity of regulations in healthcare, financial services, and other industries makes it difficult for enterprises to design and deploy effective compliance systems. We believe that in some applications, it may be practical to support compliance by using formalized portions of applicable laws to regulate business processes that use information systems. In order to explore this possibility, we use a stratified fragment of Prolog with limited use of negation to formalize a portion of the US Health Insurance Portability and Accountability Act (HIPAA). As part of our study, we also explore the deployment of our formalization in a prototype hospital Web portal messaging system.

  10. A logarithmic correction in the entropy functional formalism

    NASA Astrophysics Data System (ADS)

    Hammad, Fayçal; Faizal, Mir

    2016-04-01

    The entropy functional formalism allows one to recover general relativity, modified gravity theories, as well as the Bekenstein-Hawking entropy formula. In most approaches to quantum gravity, the Bekenstein-Hawking’s entropy formula acquires a logarithmic correction term. As such terms occur almost universally in most approaches to quantum gravity, we analyze the effect of such terms on the entropy functional formalism. We demonstrate that the leading correction to the micro-canonical entropy in the entropy functional formalism can be used to recover modified theories of gravity already obtained with an uncorrected micro-canonical entropy. Furthermore, since the entropy functional formalism reproduces modified gravity, the rise of gravity-dependent logarithmic corrections turns out to be one way to impose constraints on these theories of modified gravity. The constraints found here for the simple case of an ℱ(R)-gravity are the same as those obtained in the literature from cosmological considerations.

  11. Formal Program Development in Library Education in Nigeria.

    ERIC Educational Resources Information Center

    Ogunsheye, F. A.

    1978-01-01

    The formal program developments and trends at the Ibadan University Library School with a postgraduate program, and the Ahmadu Bello School, with an undergraduate program, are reviewed in relation to society's information needs. (Author/MBR)

  12. A Formal Total Synthesis of (−)-Brevisamide

    PubMed Central

    Smith, Amos B.; Kutsumura, Noriki; Potuzak, Justin

    2011-01-01

    A formal total synthesis of (−)-brevisamide has been achieved. The synthetic approach highlights a chemoselective asymmetric dihydroxylation and a one-pot Fraser-Reid epoxidation/PMB protection reaction sequence. PMID:21572531

  13. On an order reduction theorem in the Lagrangian formalism

    NASA Astrophysics Data System (ADS)

    Grigore, D. R.

    1996-11-01

    We provide a new proof of a important theorem in the Lagrangian formalism about necessary and sufficient conditions for a second-order variational system of equations to follow from a first-order Lagrangian.

  14. Formal methods and digital systems validation for airborne systems

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1993-01-01

    This report has been prepared to supplement a forthcoming chapter on formal methods in the FAA Digital Systems Validation Handbook. Its purpose is as follows: to outline the technical basis for formal methods in computer science; to explain the use of formal methods in the specification and verification of software and hardware requirements, designs, and implementations; to identify the benefits, weaknesses, and difficulties in applying these methods to digital systems used on board aircraft; and to suggest factors for consideration when formal methods are offered in support of certification. These latter factors assume the context for software development and assurance described in RTCA document DO-178B, 'Software Considerations in Airborne Systems and Equipment Certification,' Dec. 1992.

  15. Experiences Using Lightweight Formal Methods for Requirements Modeling

    NASA Technical Reports Server (NTRS)

    Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David

    1997-01-01

    This paper describes three case studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, formal methods enhanced the existing verification and validation processes, by testing key properties of the evolving requirements, and helping to identify weaknesses. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations.

  16. Graduate nurse internship program: a formalized orientation program.

    PubMed

    Phillips, Tracy; Hall, Mellisa

    2014-01-01

    The graduate nurse internship program was developed on the basis of Watson's Human Caring Theory. In this article, the author discusses how an orientation program was formalized into an internship program and how the theory was applied. PMID:25036082

  17. Cultural diversity and differences in formal reasoning ability

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.; Bealer, Jonathan M.

    To test the hypothesis that cultural diversity contributes to the development of formal reasoning, samples of adolescents from three predominately white middle-class communities located in areas that varied in the extent to which they offered cultural diversity (i.e., rural, suburan homogeneous, suburban heterogeneous) were administered a test of formal reasoning and a test of analytical intelligence. Results showed significant differences in formal reasoning in favor of the suburban heterogeneous sample on complex reasoning items. The suburban groups showed equal performance (but superior to the rural Ss) on the test of analytical intelligence. On the less complex reasoning items and on one item embedded in a rural farming context, the rural Ss showed relatively better performance. Implications for using science instruction to promote formal reasoning are discussed.

  18. Understanding visualization: a formal approach using category theory and semiotics.

    PubMed

    Vickers, Paul; Faith, Joe; Rossiter, Nick

    2013-06-01

    This paper combines the vocabulary of semiotics and category theory to provide a formal analysis of visualization. It shows how familiar processes of visualization fit the semiotic frameworks of both Saussure and Peirce, and extends these structures using the tools of category theory to provide a general framework for understanding visualization in practice, including: Relationships between systems, data collected from those systems, renderings of those data in the form of representations, the reading of those representations to create visualizations, and the use of those visualizations to create knowledge and understanding of the system under inspection. The resulting framework is validated by demonstrating how familiar information visualization concepts (such as literalness, sensitivity, redundancy, ambiguity, generalizability, and chart junk) arise naturally from it and can be defined formally and precisely. This paper generalizes previous work on the formal characterization of visualization by, inter alia, Ziemkiewicz and Kosara and allows us to formally distinguish properties of the visualization process that previous work does not. PMID:23559513

  19. Using formal specification in the Guidance and Control Software (GCS) experiment. Formal design and verification technology for life critical systems

    NASA Technical Reports Server (NTRS)

    Weber, Doug; Jamsek, Damir

    1994-01-01

    The goal of this task was to investigate how formal methods could be incorporated into a software engineering process for flight-control systems under DO-178B and to demonstrate that process by developing a formal specification for NASA's Guidance and Controls Software (GCS) Experiment. GCS is software to control the descent of a spacecraft onto a planet's surface. The GCS example is simplified from a real example spacecraft, but exhibits the characteristics of realistic spacecraft control software. The formal specification is written in Larch.

  20. Darboux transformations for (1+2)-dimensional Fokker-Planck equations with constant diffusion matrix

    SciTech Connect

    Schulze-Halberg, Axel

    2012-10-15

    We construct a Darboux transformation for (1+2)-dimensional Fokker-Planck equations with constant diffusion matrix. Our transformation is based on the two-dimensional supersymmetry formalism for the Schroedinger equation. The transformed Fokker-Planck equation and its solutions are obtained in explicit form.

  1. Matrix elements of explicitly correlated Gaussian basis functions with arbitrary angular momentum

    NASA Astrophysics Data System (ADS)

    Joyce, Tennesse; Varga, Kálmán

    2016-05-01

    A new algorithm for calculating the Hamiltonian matrix elements with all-electron explicitly correlated Gaussian functions for quantum-mechanical calculations of atoms with arbitrary angular momentum is presented. The calculations are checked on several excited states of three and four electron systems. The presented formalism can be used as unified framework for high accuracy calculations of properties of small atoms and molecules.

  2. Paths correlation matrix.

    PubMed

    Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang

    2015-09-15

    Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions. PMID:26371930

  3. Skinner-Rusk unified formalism for higher-order systems

    NASA Astrophysics Data System (ADS)

    Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2012-07-01

    The Lagrangian-Hamiltonian unified formalism of R. Skinner and R. Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, first-order and higher-order field theories, and higher-order autonomous systems. In this work we present a generalization of this formalism for higher-order non-autonomous mechanical systems.

  4. Formal analysis of device authentication applications in ubiquitous computing.

    SciTech Connect

    Shin, Dongwan; Claycomb, William R.

    2010-11-01

    Authentication between mobile devices in ad-hoc computing environments is a challenging problem. Without pre-shared knowledge, existing applications rely on additional communication methods, such as out-of-band or location-limited channels for device authentication. However, no formal analysis has been conducted to determine whether out-of-band channels are actually necessary. We answer this question through formal analysis, and use BAN logic to show that device authentication using a single channel is not possible.

  5. Formal functional test designs with a test representation language

    NASA Technical Reports Server (NTRS)

    Hops, J. M.

    1993-01-01

    The application of the category-partition method to the test design phase of hardware, software, or system test development is discussed. The method provides a formal framework for reducing the total number of possible test cases to a minimum logical subset for effective testing. An automatic tool and a formal language were developed to implement the method and produce the specification of test cases.

  6. Hypercube matrix computation task

    NASA Technical Reports Server (NTRS)

    Calalo, Ruel H.; Imbriale, William A.; Jacobi, Nathan; Liewer, Paulett C.; Lockhart, Thomas G.; Lyzenga, Gregory A.; Lyons, James R.; Manshadi, Farzin; Patterson, Jean E.

    1988-01-01

    A major objective of the Hypercube Matrix Computation effort at the Jet Propulsion Laboratory (JPL) is to investigate the applicability of a parallel computing architecture to the solution of large-scale electromagnetic scattering problems. Three scattering analysis codes are being implemented and assessed on a JPL/California Institute of Technology (Caltech) Mark 3 Hypercube. The codes, which utilize different underlying algorithms, give a means of evaluating the general applicability of this parallel architecture. The three analysis codes being implemented are a frequency domain method of moments code, a time domain finite difference code, and a frequency domain finite elements code. These analysis capabilities are being integrated into an electromagnetics interactive analysis workstation which can serve as a design tool for the construction of antennas and other radiating or scattering structures. The first two years of work on the Hypercube Matrix Computation effort is summarized. It includes both new developments and results as well as work previously reported in the Hypercube Matrix Computation Task: Final Report for 1986 to 1987 (JPL Publication 87-18).

  7. Proceedings of the First NASA Formal Methods Symposium

    NASA Technical Reports Server (NTRS)

    Denney, Ewen (Editor); Giannakopoulou, Dimitra (Editor); Pasareanu, Corina S. (Editor)

    2009-01-01

    Topics covered include: Model Checking - My 27-Year Quest to Overcome the State Explosion Problem; Applying Formal Methods to NASA Projects: Transition from Research to Practice; TLA+: Whence, Wherefore, and Whither; Formal Methods Applications in Air Transportation; Theorem Proving in Intel Hardware Design; Building a Formal Model of a Human-Interactive System: Insights into the Integration of Formal Methods and Human Factors Engineering; Model Checking for Autonomic Systems Specified with ASSL; A Game-Theoretic Approach to Branching Time Abstract-Check-Refine Process; Software Model Checking Without Source Code; Generalized Abstract Symbolic Summaries; A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing; Component-Oriented Behavior Extraction for Autonomic System Design; Automated Verification of Design Patterns with LePUS3; A Module Language for Typing by Contracts; From Goal-Oriented Requirements to Event-B Specifications; Introduction of Virtualization Technology to Multi-Process Model Checking; Comparing Techniques for Certified Static Analysis; Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder; jFuzz: A Concolic Whitebox Fuzzer for Java; Machine-Checkable Timed CSP; Stochastic Formal Correctness of Numerical Algorithms; Deductive Verification of Cryptographic Software; Coloured Petri Net Refinement Specification and Correctness Proof with Coq; Modeling Guidelines for Code Generation in the Railway Signaling Context; Tactical Synthesis Of Efficient Global Search Algorithms; Towards Co-Engineering Communicating Autonomous Cyber-Physical Systems; and Formal Methods for Automated Diagnosis of Autosub 6000.

  8. Standard Errors for Matrix Correlations.

    ERIC Educational Resources Information Center

    Ogasawara, Haruhiko

    1999-01-01

    Derives the asymptotic standard errors and intercorrelations for several matrix correlations assuming multivariate normality for manifest variables and derives the asymptotic standard errors of the matrix correlations for two factor-loading matrices. (SLD)

  9. On the Matrix Exponential Function

    ERIC Educational Resources Information Center

    Hou, Shui-Hung; Hou, Edwin; Pang, Wan-Kai

    2006-01-01

    A novel and simple formula for computing the matrix exponential function is presented. Specifically, it can be used to derive explicit formulas for the matrix exponential of a general matrix A satisfying p(A) = 0 for a polynomial p(s). It is ready for use in a classroom and suitable for both hand as well as symbolic computation.

  10. Weaving a Formal Methods Education with Problem-Based Learning

    NASA Astrophysics Data System (ADS)

    Gibson, J. Paul

    The idea of weaving formal methods through computing (or software engineering) degrees is not a new one. However, there has been little success in developing and implementing such a curriculum. Formal methods continue to be taught as stand-alone modules and students, in general, fail to see how fundamental these methods are to the engineering of software. A major problem is one of motivation — how can the students be expected to enthusiastically embrace a challenging subject when the learning benefits, beyond passing an exam and achieving curriculum credits, are not clear? Problem-based learning has gradually moved from being an innovative pedagogique technique, commonly used to better-motivate students, to being widely adopted in the teaching of many different disciplines, including computer science and software engineering. Our experience shows that a good problem can be re-used throughout a student's academic life. In fact, the best computing problems can be used with children (young and old), undergraduates and postgraduates. In this paper we present a process for weaving formal methods through a University curriculum that is founded on the application of problem-based learning and a library of good software engineering problems, where students learn about formal methods without sitting a traditional formal methods module. The process of constructing good problems and integrating them into the curriculum is shown to be analagous to the process of engineering software. This approach is not intended to replace more traditional formal methods modules: it will better prepare students for such specialised modules and ensure that all students have an understanding and appreciation for formal methods even if they do not go on to specialise in them.

  11. Barriers to formal emergency obstetric care services' utilization.

    PubMed

    Essendi, Hildah; Mills, Samuel; Fotso, Jean-Christophe

    2011-06-01

    Access to appropriate health care including skilled birth attendance at delivery and timely referrals to emergency obstetric care services can greatly reduce maternal deaths and disabilities, yet women in sub-Saharan Africa continue to face limited access to skilled delivery services. This study relies on qualitative data collected from residents of two slums in Nairobi, Kenya in 2006 to investigate views surrounding barriers to the uptake of formal obstetric services. Data indicate that slum dwellers prefer formal to informal obstetric services. However, their efforts to utilize formal emergency obstetric care services are constrained by various factors including ineffective health decision making at the family level, inadequate transport facilities to formal care facilities and insecurity at night, high cost of health services, and inhospitable formal service providers and poorly equipped health facilities in the slums. As a result, a majority of slum dwellers opt for delivery services offered by traditional birth attendants (TBAs) who lack essential skills and equipment, thereby increasing the risk of death and disability. Based on these findings, we maintain that urban poor women face barriers to access of formal obstetric services at family, community, and health facility levels, and efforts to reduce maternal morbidity and mortality among the urban poor must tackle the barriers, which operate at these different levels to hinder women's access to formal obstetric care services. We recommend continuous community education on symptoms of complications related to pregnancy and timely referral. A focus on training of health personnel on "public relations" could also restore confidence in the health-care system with this populace. Further, we recommend improving the health facilities in the slums, improving the services provided by TBAs through capacity building as well as involving TBAs in referral processes to make access to services timely. Measures can also be

  12. The cellulose resource matrix.

    PubMed

    Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

    2013-03-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

  13. Quantum maximum-entropy principle for closed quantum hydrodynamic transport within a Wigner function formalism

    SciTech Connect

    Trovato, M.; Reggiani, L.

    2011-12-15

    By introducing a quantum entropy functional of the reduced density matrix, the principle of quantum maximum entropy is asserted as fundamental principle of quantum statistical mechanics. Accordingly, we develop a comprehensive theoretical formalism to construct rigorously a closed quantum hydrodynamic transport within a Wigner function approach. The theoretical formalism is formulated in both thermodynamic equilibrium and nonequilibrium conditions, and the quantum contributions are obtained by only assuming that the Lagrange multipliers can be expanded in powers of ({h_bar}/2{pi}){sup 2}. In particular, by using an arbitrary number of moments, we prove that (1) on a macroscopic scale all nonlocal effects, compatible with the uncertainty principle, are imputable to high-order spatial derivatives, both of the numerical density n and of the effective temperature T; (2) the results available from the literature in the framework of both a quantum Boltzmann gas and a degenerate quantum Fermi gas are recovered as a particular case; (3) the statistics for the quantum Fermi and Bose gases at different levels of degeneracy are explicitly incorporated; (4) a set of relevant applications admitting exact analytical equations are explicitly given and discussed; (5) the quantum maximum entropy principle keeps full validity in the classical limit, when ({h_bar}/2{pi}){yields}0.

  14. Kinematic matrix theory and universalities in self-propellers and active swimmers.

    PubMed

    Nourhani, Amir; Lammert, Paul E; Borhan, Ali; Crespi, Vincent H

    2014-06-01

    We describe an efficient and parsimonious matrix-based theory for studying the ensemble behavior of self-propellers and active swimmers, such as nanomotors or motile bacteria, that are typically studied by differential-equation-based Langevin or Fokker-Planck formalisms. The kinematic effects for elementary processes of motion are incorporated into a matrix, called the "kinematrix," from which we immediately obtain correlators and the mean and variance of angular and position variables (and thus effective diffusivity) by simple matrix algebra. The kinematrix formalism enables us recast the behaviors of a diverse range of self-propellers into a unified form, revealing universalities in their ensemble behavior in terms of new emergent time scales. Active fluctuations and hydrodynamic interactions can be expressed as an additive composition of separate self-propellers. PMID:25019773

  15. Formal methods in the development of safety critical software systems

    SciTech Connect

    Williams, L.G.

    1991-11-15

    As the use of computers in critical control systems such as aircraft controls, medical instruments, defense systems, missile controls, and nuclear power plants has increased, concern for the safety of those systems has also grown. Much of this concern has focused on the software component of those computer-based systems. This is primarily due to historical experience with software systems that often exhibit larger numbers of errors than their hardware counterparts and the fact that the consequences of a software error may endanger human life, property, or the environment. A number of different techniques have been used to address the issue of software safety. Some are standard software engineering techniques aimed at reducing the number of faults in a software protect, such as reviews and walkthroughs. Others, including fault tree analysis, are based on identifying and reducing hazards. This report examines the role of one such technique, formal methods, in the development of software for safety critical systems. The use of formal methods to increase the safety of software systems is based on their role in reducing the possibility of software errors that could lead to hazards. The use of formal methods in the development of software systems is controversial. Proponents claim that the use of formal methods can eliminate errors from the software development process, and produce programs that are probably correct. Opponents claim that they are difficult to learn and that their use increases development costs unacceptably. This report discusses the potential of formal methods for reducing failures in safety critical software systems.

  16. Formalizing an electronic institution for the distribution of human tissues.

    PubMed

    Vázquez-Salceda, J; Padget, J A; Cortés, U; López-Navidad, A; Caballero, F

    2003-03-01

    The use of multi-agent systems (MAS) in health-care domains is increasing. Such agent-mediated medical systems can manage complex tasks and have the potential to adapt gracefully to unexpected events. However, in these kinds of systems the issues of privacy, security and trust are particularly sensitive in relation to matters such as agents' access to patient records, what is acceptable behaviour for an agent in a particular role and the development of trust both between (heterogeneous) agents and between users and agents. To address these issues we propose a formal normative framework, deriving from and developing the notion of an electronic institution. Such institutions provide a framework to define and police norms that guide, control and regulate the behaviour of the heterogeneous agents that participate in the institution. These norms define the acceptable actions that each agent may perform depending on the role or roles it is playing, and clearly specifies the data it may access and/or modify in playing those roles. In this paper, we present the formalization of Carrel, a virtual organization for the procurement of organs and tissues for transplantation purposes, as an electronic institution using the ISLANDER institution specification language as formalizing languages. We demonstrate aspects of the formalization of such an institution, example fragments in the language used for the textual specification, and how such formalization can be used as a blueprint in the implementation of the final agent architecture, through techniques such as skeleton generation. PMID:12667738

  17. Proceedings of the Sixth NASA Langley Formal Methods (LFM) Workshop

    NASA Technical Reports Server (NTRS)

    Rozier, Kristin Yvonne (Editor)

    2008-01-01

    Today's verification techniques are hard-pressed to scale with the ever-increasing complexity of safety critical systems. Within the field of aeronautics alone, we find the need for verification of algorithms for separation assurance, air traffic control, auto-pilot, Unmanned Aerial Vehicles (UAVs), adaptive avionics, automated decision authority, and much more. Recent advances in formal methods have made verifying more of these problems realistic. Thus we need to continually re-assess what we can solve now and identify the next barriers to overcome. Only through an exchange of ideas between theoreticians and practitioners from academia to industry can we extend formal methods for the verification of ever more challenging problem domains. This volume contains the extended abstracts of the talks presented at LFM 2008: The Sixth NASA Langley Formal Methods Workshop held on April 30 - May 2, 2008 in Newport News, Virginia, USA. The topics of interest that were listed in the call for abstracts were: advances in formal verification techniques; formal models of distributed computing; planning and scheduling; automated air traffic management; fault tolerance; hybrid systems/hybrid automata; embedded systems; safety critical applications; safety cases; accident/safety analysis.

  18. Formal verification of digital circuits described in VHDL

    NASA Astrophysics Data System (ADS)

    Salem, Ashraf Mohammed El-Farghly

    1992-01-01

    The formal verification of digital circuits described in VHSIC (very high speed integrated circuit) hardware description language (VHDL) is presented. VHDL is made processable by proof tools. A subset, called P-VHDL, dedicated to the description of combinatorial and synchronous sequential circuits is defined. The semantics of this subset is much simpler than the complete VHDL. The delta delay is replaced by a serialization function, and the time scale is chosen equal to the clock period. The use of the finite state machine as a formal model for the subset became possible. The finite state machine semantics is shown to represent the P-VHDL semantics. Based on this formal model, a proof oriented compiler for P-VHDL is written. A complete denotational semantic for P-VHDL is defined. Three different domains for the three values holders in the language are proposed: the variables, the signals, and the registers. Formal semantics for the VHDL timing constructs are given. The equivalence between these semantics and the VHDL informal operational semantics is proven. It is shown that semantics can form a basis for building a formal timing verifier.

  19. Formal Verification of the AAMP-FV Microcode

    NASA Technical Reports Server (NTRS)

    Miller, Steven P.; Greve, David A.; Wilding, Matthew M.; Srivas, Mandayam

    1999-01-01

    This report describes the experiences of Collins Avionics & Communications and SRI International in formally specifying and verifying the microcode in a Rockwell proprietary microprocessor, the AAMP-FV, using the PVS verification system. This project built extensively on earlier experiences using PVS to verify the microcode in the AAMP5, a complex, pipelined microprocessor designed for use in avionics displays and global positioning systems. While the AAMP5 experiment demonstrated the technical feasibility of formal verification of microcode, the steep learning curve encountered left unanswered the question of whether it could be performed at reasonable cost. The AAMP-FV project was conducted to determine whether the experience gained on the AAMP5 project could be used to make formal verification of microcode cost effective for safety-critical and high volume devices.

  20. Pedagogical basis of DAS formalism in engineering education

    NASA Astrophysics Data System (ADS)

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-03-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other engineering fields. The motivation for this new curriculum structure originates from the urge to solve the problems that engineering education has faced during the past decades, e.g. student recruitment problems and dissatisfactory learning outcomes. The focus of this paper is on the structure of the curriculum but the content is also discussed when it has an effect on the structure and its implementation. The presented structure, i.e. DAS formalism, builds upon the ideas of some classical pedagogical theories, which have regularly been applied at course level but seldom used to solve curriculum-level issues.

  1. Formalizing New Navigation Requirements for NASA's Space Shuttle

    NASA Technical Reports Server (NTRS)

    DiVito, Ben L.

    1996-01-01

    We describe a recent NASA-sponsored pilot project intended to gauge the effectiveness of using formal methods in Space Shuttle software requirements analysis. Several Change Requests (CRs) were selected as promising targets to demonstrate the utility of formal methods in this demanding application domain. A CR to add new navigation capabilities to the Shuttle, based on Global Positioning System (GPS) technology, is the focus of this industrial usage report. Portions of the GPS CR were modeled using the language of SRI's Prototype Verification System (PVS). During a limited analysis conducted on the formal specifications, numerous requirements issues were discovered. We present a summary of these encouraging results and conclusions we have drawn from the pilot project.

  2. Delta-N formalism for curvaton with modulated decay

    SciTech Connect

    Kohri, Kazunori; Lin, Chia-Min; Matsuda, Tomohiro E-mail: cmlin@boar.kobe-u.ac.jp

    2013-06-01

    In this paper, the curvature perturbation generated by the modulated curvaton decay is studied by a direct application of δN-formalism. Our method has a sharp contrast with the non-linear formalism which may be regarded as an indirect usage of δN-formalism. We first show that our method can readily reproduce results in previous works of modulation of curvaton. Then we move on to calculate the case where the curvaton mass (and hence also the decay rate) is modulated. The method can be applied to the calculation of the modulation in the freezeout model, in which the heavy species are considered instead of the curvaton. Our method explains curvaton and various modulation on an equal footing.

  3. Formally Verified Practical Algorithms for Recovery from Loss of Separation

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Munoz, Caesar A.

    2009-01-01

    In this paper, we develop and formally verify practical algorithms for recovery from loss of separation. The formal verification is performed in the context of a criteria-based framework. This framework provides rigorous definitions of horizontal and vertical maneuver correctness that guarantee divergence and achieve horizontal and vertical separation. The algorithms are shown to be independently correct, that is, separation is achieved when only one aircraft maneuvers, and implicitly coordinated, that is, separation is also achieved when both aircraft maneuver. In this paper we improve the horizontal criteria over our previous work. An important benefit of the criteria approach is that different aircraft can execute different algorithms and implicit coordination will still be achieved, as long as they all meet the explicit criteria of the framework. Towards this end we have sought to make the criteria as general as possible. The framework presented in this paper has been formalized and mechanically verified in the Prototype Verification System (PVS).

  4. Formal verification of a fault tolerant clock synchronization algorithm

    NASA Technical Reports Server (NTRS)

    Rushby, John; Vonhenke, Frieder

    1989-01-01

    A formal specification and mechanically assisted verification of the interactive convergence clock synchronization algorithm of Lamport and Melliar-Smith is described. Several technical flaws in the analysis given by Lamport and Melliar-Smith were discovered, even though their presentation is unusally precise and detailed. It seems that these flaws were not detected by informal peer scrutiny. The flaws are discussed and a revised presentation of the analysis is given that not only corrects the flaws but is also more precise and easier to follow. Some of the corrections to the flaws require slight modifications to the original assumptions underlying the algorithm and to the constraints on its parameters, and thus change the external specifications of the algorithm. The formal analysis of the interactive convergence clock synchronization algorithm was performed using the Enhanced Hierarchical Development Methodology (EHDM) formal specification and verification environment. This application of EHDM provides a demonstration of some of the capabilities of the system.

  5. Weak Quantum Theory: Formal Framework and Selected Applications

    SciTech Connect

    Atmanspacher, Harald; Filk, Thomas; Roemer, Hartmann

    2006-01-04

    Two key concepts of quantum theory, complementarity and entanglement, are considered with respect to their significance in and beyond physics. An axiomatically formalized, weak version of quantum theory, more general than the ordinary quantum theory of physical systems, is described. Its mathematical structure generalizes the algebraic approach to ordinary quantum theory. The crucial formal feature leading to complementarity and entanglement is the non-commutativity of observables.The ordinary Hilbert space quantum mechanics can be recovered by stepwise adding the necessary features. This provides a hierarchy of formal frameworks of decreasing generality and increasing specificity. Two concrete applications, more specific than weak quantum theory and more general than ordinary quantum theory, are discussed: (i) complementarity and entanglement in classical dynamical systems, and (ii) complementarity and entanglement in the bistable perception of ambiguous stimuli.

  6. A Formal Approach to Requirements-Based Programming

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

    2005-01-01

    No significant general-purpose method is currently available to mechanically transform system requirements into a provably equivalent model. The widespread use of such a method represents a necessary step toward high-dependability system engineering for numerous application domains. Current tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The "gap" unfilled by such tools and methods is that the formal models cannot be proven to be equivalent to the requirements. We offer a method for mechanically transforming requirements into a provably equivalent formal model that can be used as the basis for code generation and other transformations. This method is unique in offering full mathematical tractability while using notations and techniques that are well known and well trusted. Finally, we describe further application areas we are investigating for use of the approach.

  7. Formal mechanization of device interactions with a process algebra

    NASA Technical Reports Server (NTRS)

    Schubert, E. Thomas; Levitt, Karl; Cohen, Gerald C.

    1992-01-01

    The principle emphasis is to develop a methodology to formally verify correct synchronization communication of devices in a composed hardware system. Previous system integration efforts have focused on vertical integration of one layer on top of another. This task examines 'horizontal' integration of peer devices. To formally reason about communication, we mechanize a process algebra in the Higher Order Logic (HOL) theorem proving system. Using this formalization we show how four types of device interactions can be represented and verified to behave as specified. The report also describes the specification of a system consisting of an AVM-1 microprocessor and a memory management unit which were verified in previous work. A proof of correct communication is presented, and the extensions to the system specification to add a direct memory device are discussed.

  8. Evidence Arguments for Using Formal Methods in Software Certification

    NASA Technical Reports Server (NTRS)

    Denney, Ewen W.; Pai, Ganesh

    2013-01-01

    We describe a generic approach for automatically integrating the output generated from a formal method/tool into a software safety assurance case, as an evidence argument, by (a) encoding the underlying reasoning as a safety case pattern, and (b) instantiating it using the data produced from the method/tool. We believe this approach not only improves the trustworthiness of the evidence generated from a formal method/tool, by explicitly presenting the reasoning and mechanisms underlying its genesis, but also provides a way to gauge the suitability of the evidence in the context of the wider assurance case. We illustrate our work by application to a real example-an unmanned aircraft system- where we invoke a formal code analysis tool from its autopilot software safety case, automatically transform the verification output into an evidence argument, and then integrate it into the former.

  9. Infections on Temporal Networks—A Matrix-Based Approach

    PubMed Central

    Koher, Andreas; Lentz, Hartmut H. K.; Hövel, Philipp; Sokolov, Igor M.

    2016-01-01

    We extend the concept of accessibility in temporal networks to model infections with a finite infectious period such as the susceptible-infected-recovered (SIR) model. This approach is entirely based on elementary matrix operations and unifies the disease and network dynamics within one algebraic framework. We demonstrate the potential of this formalism for three examples of networks with high temporal resolution: networks of social contacts, sexual contacts, and livestock-trade. Our investigations provide a new methodological framework that can be used, for instance, to estimate the epidemic threshold, a quantity that determines disease parameters, for which a large-scale outbreak can be expected. PMID:27035128

  10. Infections on Temporal Networks--A Matrix-Based Approach.

    PubMed

    Koher, Andreas; Lentz, Hartmut H K; Hövel, Philipp; Sokolov, Igor M

    2016-01-01

    We extend the concept of accessibility in temporal networks to model infections with a finite infectious period such as the susceptible-infected-recovered (SIR) model. This approach is entirely based on elementary matrix operations and unifies the disease and network dynamics within one algebraic framework. We demonstrate the potential of this formalism for three examples of networks with high temporal resolution: networks of social contacts, sexual contacts, and livestock-trade. Our investigations provide a new methodological framework that can be used, for instance, to estimate the epidemic threshold, a quantity that determines disease parameters, for which a large-scale outbreak can be expected. PMID:27035128

  11. Memory matrix theory of magnetotransport in strange metals

    NASA Astrophysics Data System (ADS)

    Lucas, Andrew; Sachdev, Subir

    2015-05-01

    We model strange metals as quantum liquids without quasiparticle excitations, but with slow momentum relaxation and with slow diffusive dynamics of a conserved charge and energy. General expressions are obtained for electrical, thermal, and thermoelectric transport in the presence of an applied magnetic field using the memory matrix formalism. In the appropriate limits, our expressions agree with previous hydrodynamic and holographic results. We discuss the relationship of such results to thermoelectric and Hall transport measurements in the strange-metal phase of the hole-doped cuprates.

  12. Transfer-matrix approach for modulated structures with defects

    SciTech Connect

    Kostyrko, T.; Institute of Physics, A. Mickiewicz University, ulica Umultowska 85, 61-614 Poznan,

    2000-07-15

    We consider scattering of electrons by defects in a periodically modulated, quasi-one-dimensional structure, within a tight-binding model. Combining a transfer matrix method and a Green function method we derive a formula for a Landauer conductance and show its equivalence to the result of Kubo linear response theory. We obtain explicitly unperturbed lattice Green functions from their equations of motion, using the transfer matrices. We apply the presented formalism in computations of the conductance of several multiband modulated structures with defects: (a) carbon nanotubes (b) two-dimensional (2D) superlattice (c) modulated leads with 1D wire in the tunneling regime. (c) 2000 The American Physical Society.

  13. Fake Instability in the Euclidean Formalism of Quantum Tunneling

    SciTech Connect

    Aoyama, H.; Harano, T.; Sato, M.; Kikuchi, H.; Wada, S.

    1997-11-01

    The Euclidean path-integral formalism is studied for the system without any unstable state. While the usual bounce calculation yields a fake complex energy spectrum, proper account of the global structure of the functional space is shown to lead to the real eigenvalues. For this purpose, the valley instanton is constructed by the proper valley method and the dilute-gas approximation is carried out. This establishes a general imaginary-time formalism, unifying the instanton and the bounce method. {copyright} {ital 1997} {ital The American Physical Society}

  14. Unified formalism for higher order non-autonomous dynamical systems

    NASA Astrophysics Data System (ADS)

    Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2012-03-01

    This work is devoted to giving a geometric framework for describing higher order non-autonomous mechanical systems. The starting point is to extend the Lagrangian-Hamiltonian unified formalism of Skinner and Rusk for these kinds of systems, generalizing previous developments for higher order autonomous mechanical systems and first-order non-autonomous mechanical systems. Then, we use this unified formulation to derive the standard Lagrangian and Hamiltonian formalisms, including the Legendre-Ostrogradsky map and the Euler-Lagrange and the Hamilton equations, both for regular and singular systems. As applications of our model, two examples of regular and singular physical systems are studied.

  15. Skinner Rusk unified formalism for optimal control systems and applications

    NASA Astrophysics Data System (ADS)

    Barbero-Liñán, María; Echeverría-Enríquez, Arturo; Martín de Diego, David; Muñoz-Lecanda, Miguel C.; Román-Roy, Narciso

    2007-10-01

    A geometric approach to time-dependent optimal control problems is proposed. This formulation is based on the Skinner and Rusk formalism for Lagrangian and Hamiltonian systems. The corresponding unified formalism developed for optimal control systems allows us to formulate geometrically the necessary conditions given by a weak form of Pontryagin's maximum principle, provided that the differentiability with respect to controls is assumed and the space of controls is open. Furthermore, our method is also valid for implicit optimal control systems and, in particular, for the so-called descriptor systems (optimal control problems including both differential and algebraic equations).

  16. The generation of gravitational waves. II - The postlinear formalism revisited

    NASA Technical Reports Server (NTRS)

    Crowley, R. J.; Thorne, K. S.

    1977-01-01

    Two different versions of the Green's function for the scalar wave equation in weakly curved spacetime (one due to DeWitt and DeWitt, the other to Thorne and Kovacs) are compared and contrasted; and their mathematical equivalence is demonstrated. Then the DeWitt-DeWitt Green's function is used to construct several alternative versions of the Thorne-Kovacs postlinear formalism for gravitational-wave generation. Finally it is shown that, in calculations of gravitational bremsstrahlung radiation, some of our versions of the postlinear formalism allow one to treat the interacting bodies as point masses, while others do not.

  17. Statistical foundation of the fluid analogue of the soliton formalism

    NASA Technical Reports Server (NTRS)

    Tchen, C. M.

    1986-01-01

    A fully nonlinear analysis is used to develop a general soliton formalism for the description of the nonlinear evolution of soliton fluctuations in both plasmas and classical fluids. From the Navier-Stokes equations for plasmas and compressible fluids of two scales, two equations for the propagation of density waves are derived. A fast soliton field is spontaneously created by rarefaction, and a slow density wave modulates the field intensity as a ponderomotive force. Constitutive properties are demonstrated using a Lagrangian-kinetic formalism of the fluctuation-dissipation theory.

  18. A Catalytic, Enantioselective Formal Synthesis of (+)-Dichroanone and (+)-Taiwaniaquinone H

    PubMed Central

    2015-01-01

    A catalytic, enantioselective formal synthesis of (+)-dichroanone and (+)-taiwaniaquinone H is reported. The all-carbon quaternary stereocenter was constructed by asymmetric conjugate addition catalyzed by a palladium(II) (S)-tert-butylpyridinooxazoline complex. The unexpected formation of a [3.2.1] bicyclic intermediate required the identification of a new route. Analysis of the Hammett constants for para-substituted arenes enabled the rational design of a highly enantioselective conjugate addition substrate that led to the completion of the formal synthesis. PMID:25489925

  19. Ceramic matrix and resin matrix composites: A comparison

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1987-01-01

    The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

  20. Ceramic matrix and resin matrix composites - A comparison

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1987-01-01

    The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

  1. Light cone matrix product

    SciTech Connect

    Hastings, Matthew B

    2009-01-01

    We show how to combine the light-cone and matrix product algorithms to simulate quantum systems far from equilibrium for long times. For the case of the XXZ spin chain at {Delta} = 0.5, we simulate to a time of {approx} 22.5. While part of the long simulation time is due to the use of the light-cone method, we also describe a modification of the infinite time-evolving bond decimation algorithm with improved numerical stability, and we describe how to incorporate symmetry into this algorithm. While statistical sampling error means that we are not yet able to make a definite statement, the behavior of the simulation at long times indicates the appearance of either 'revivals' in the order parameter as predicted by Hastings and Levitov (e-print arXiv:0806.4283) or of a distinct shoulder in the decay of the order parameter.

  2. Google matrix of Twitter

    NASA Astrophysics Data System (ADS)

    Frahm, K. M.; Shepelyansky, D. L.

    2012-10-01

    We construct the Google matrix of the entire Twitter network, dated by July 2009, and analyze its spectrum and eigenstate properties including the PageRank and CheiRank vectors and 2DRanking of all nodes. Our studies show much stronger inter-connectivity between top PageRank nodes for the Twitter network compared to the networks of Wikipedia and British Universities studied previously. Our analysis allows to locate the top Twitter users which control the information flow on the network. We argue that this small fraction of the whole number of users, which can be viewed as the social network elite, plays the dominant role in the process of opinion formation on the network.

  3. Hyaluronan: A Matrix Component

    NASA Astrophysics Data System (ADS)

    Rügheimer, Louise

    2008-09-01

    The glucosaminoglycan hyaluronan is a key component of the extracellular matrix. It is a large, negatively charged molecule that can act as an ion exchange reservoir for positive ions. Hyaluronan is involved in renomedullary water handling through its water-binding capacity. In the renal medulla, the main source for hyaluronan production is the renomedullary interstitial cells. Hyaluronan synthases are found in the inner part of the plasma membrane and polymerize hyaluronan chains which are extruded into the extracellular space. Hyaluronidases are a family of enzymes involved in the degradation of hyaluronan. They have a wide range of properties, including differences in size, inhibitor sensitivities, catalytic mechanisms, substrate specificities and pH optima.

  4. Mixed Mode Matrix Multiplication

    SciTech Connect

    Meng-Shiou Wu; Srinivas Aluru; Ricky A. Kendall

    2004-09-30

    In modern clustering environments where the memory hierarchy has many layers (distributed memory, shared memory layer, cache,...), an important question is how to fully utilize all available resources and identify the most dominant layer in certain computations. When combining algorithms on all layers together, what would be the best method to get the best performance out of all the resources we have? Mixed mode programming model that uses thread programming on the shared memory layer and message passing programming on the distributed memory layer is a method that many researchers are using to utilize the memory resources. In this paper, they take an algorithmic approach that uses matrix multiplication as a tool to show how cache algorithms affect the performance of both shared memory and distributed memory algorithms. They show that with good underlying cache algorithm, overall performance is stable. When underlying cache algorithm is bad, superlinear speedup may occur, and an increasing number of threads may also improve performance.

  5. Matrix membranes and integrability

    SciTech Connect

    Zachos, C.; Fairlie, D.; Curtright, T.

    1997-06-01

    This is a pedagogical digest of results reported in Curtright, Fairlie, {ampersand} Zachos 1997, and an explicit implementation of Euler`s construction for the solution of the Poisson Bracket dual Nahm equation. But it does not cover 9 and 10-dimensional systems, and subsequent progress on them Fairlie 1997. Cubic interactions are considered in 3 and 7 space dimensions, respectively, for bosonic membranes in Poisson Bracket form. Their symmetries and vacuum configurations are explored. Their associated first order equations are transformed to Nahm`s equations, and are hence seen to be integrable, for the 3-dimensional case, by virtue of the explicit Lax pair provided. Most constructions introduced also apply to matrix commutator or Moyal Bracket analogs.

  6. Avoiding School Management Conflicts and Crisis through Formal Communication

    ERIC Educational Resources Information Center

    Nwogbaga, David M. E.; Nwankwo, Oliver U.; Onwa, Doris O.

    2015-01-01

    This paper examined how conflicts and crisis can be avoided through formal communication. It was necessitated by the observation that most of the conflicts and crisis which tend to mar school management today are functions of the inconsistencies arising from "grapevines, rumours, and gossips" generated through informal communication…

  7. Non-Formal Education for Women in Morocco.

    ERIC Educational Resources Information Center

    Agency for International Development (Dept. of State), Washington, DC.

    Morocco's three non-formal educational programs for "the hard core poor female adolescent school drop-out" differ in the kind and effectiveness of training offered. The Foyers Feminins program, although it claims to emphasize crafts and literacy, is in fact, definitely geared towards the teaching of handicrafts. The Ouvroir Centers provide…

  8. Mea Culpa: Formal Education and the Dis-Integrated World

    NASA Astrophysics Data System (ADS)

    Coppola, Brian P.; Daniels, Douglas S.

    Formal education has removed itself so far from any truly integrated view of the Natural World that fragmentation and certainty are prevailing ethics. Technological progress has resulted in increased specialization within academic disciplines and their concurrent separation from each other. Knowledge is extracted from a fully integrated world, but is examined and defined by the 'dis-integrated' objectives.

  9. Peer Review of a Formal Verification/Design Proof Methodology

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The role of formal verification techniques in system validation was examined. The value and the state of the art of performance proving for fault-tolerant compuers were assessed. The investigation, development, and evaluation of performance proving tools were reviewed. The technical issues related to proof methodologies are examined. The technical issues discussed are summarized.

  10. Measuring Infant Communicative Abilities: A Guide to Formal Test Selection.

    ERIC Educational Resources Information Center

    Proctor, Adele

    This guide was prepared to facilitate the practitioner's selection of formal tests for evaluating communicative behavior in clinical infant populations during the first year of life. Clinical instruments with particular emphasis on communication and emerging language and speech abilities were identified in terms of publishers' recommended…

  11. Learning Conditions for Non-Formal and Informal Workplace Learning

    ERIC Educational Resources Information Center

    Kyndt, Eva; Dochy, Filip; Nijs, Hanne

    2009-01-01

    Purpose: The purpose of this research paper is to investigate the presence of learning conditions for non-formal and informal workplace learning in relation to the characteristics of the employee and the organisation he or she works for. Design/methodology/approach: The questionnaire developed by Clauwaert and Van Bree on learning conditions was…

  12. Informal and Formal Approaches to Communicative Language Teaching.

    ERIC Educational Resources Information Center

    Ellis, Rod

    1982-01-01

    Discusses the use of the term "communicative" in describing approaches to foreign- or second-language teaching. Suggests that a distinction should be drawn between informal communicative approaches which promote second-language acquisition and formal communicative approaches which promote conscious learning. Examines conditions for achieving both…

  13. Acquisition of Formal Operations: The Effects of Two Training Procedures.

    ERIC Educational Resources Information Center

    Rosenthal, Doreen A.

    1979-01-01

    A study of 11- and 12-year-old girls indicates that either of two training procedures, method training or dimension training, can aid in the transition from concrete operational to formal operational thought by promoting a hypothesis-testing attitude. (BH)

  14. A Formal Approach to Domain-Oriented Software Design Environments

    NASA Technical Reports Server (NTRS)

    Lowry, Michael; Philpot, Andrew; Pressburger, Thomas; Underwood, Ian; Lum, Henry, Jr. (Technical Monitor)

    1994-01-01

    This paper describes a formal approach to domain-oriented software design environments, based on declarative domain theories, formal specifications, and deductive program synthesis. A declarative domain theory defines the semantics of a domain-oriented specification language and its relationship to implementation-level subroutines. Formal specification development and reuse is made accessible to end-users through an intuitive graphical interface that guides them in creating diagrams denoting formal specifications. The diagrams also serve to document the specifications. Deductive program synthesis ensures that end-user specifications are correctly implemented. AMPHION has been applied to the domain of solar system kinematics through the development of a declarative domain theory, which includes an axiomatization of JPL's SPICELIB subroutine library. Testing over six months with planetary scientists indicates that AMPHION's interactive specification acquisition paradigm enables users to develop, modify, and reuse specifications at least an order of magnitude more rapidly than manual program development. Furthermore, AMPHION synthesizes one to two page programs consisting of calls to SPICELIB subroutines from these specifications in just a few minutes. Test results obtained by metering AMPHION's deductive program synthesis component are examined. AMPHION has been installed at JPL and is currently undergoing further refinement in preparation for distribution to hundreds of SPICELIB users worldwide. Current work to support end-user customization of AMPHION's specification acquisition subsystem is briefly discussed, as well as future work to enable domain-expert creation of new AMPHION applications through development of suitable domain theories.

  15. Formal Training in Collective Bargaining: Superintendents' Perspective

    ERIC Educational Resources Information Center

    Johnson, Celine M.

    2013-01-01

    The purpose of this qualitative study is to investigate superintendents' perspectives of the value of formal training in collective bargaining negotiations. Dependent on their responses, one could propose negotiation skills training as a crucial area of need for superintendents. Social interdependence theory provides the theoretical framework…

  16. Gluon production in the Lipatov effective action formalism

    NASA Astrophysics Data System (ADS)

    Braun, M. A.; Pozdnyakov, S. S.; Salykin, M. Yu.; Vyazovsky, M. I.

    2013-09-01

    Gluon production on two scattering centers is studied in the formalism of reggeized gluons. Different contributions to the inclusive cross section are derived with the help of the Lipatov effective action. The AGK relations between these contributions are established. The inclusive cross section found is compared to the one in the dipole picture and demonstrated to be the same.

  17. Lfm2000: Fifth NASA Langley Formal Methods Workshop

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael (Compiler)

    2000-01-01

    This is the proceedings of Lfm2000: Fifth NASA Langley Formal Methods Workshop. The workshop was held June 13-15, 2000, in Williamsburg, Virginia. See the web site for complete information about the event.

  18. Spatial Proportional Reasoning Is Associated with Formal Knowledge about Fractions

    ERIC Educational Resources Information Center

    Möhring, Wenke; Newcombe, Nora S.; Levine, Susan C.; Frick, Andrea

    2016-01-01

    Proportional reasoning involves thinking about parts and wholes (i.e., about fractional quantities). Yet, research on proportional reasoning and fraction learning has proceeded separately. This study assessed proportional reasoning and formal fraction knowledge in 8- to 10-year-olds. Participants (N = 52) saw combinations of cherry juice and water…

  19. Theoretical and Practical Signifiance of Formal Thought: Some Considerations.

    ERIC Educational Resources Information Center

    Linn, Marcia C.

    This document discusses the relation between adolescents' expertise (their informational background, which can be accurate or inaccurate, about a particular task or subject) and their formal operational reasoning, and reports the results of three studies of the effects of children's expertise on reasoning. In Study I, adolescents from a rural…

  20. Towards a formalism for conversation protocols using joint intention theory

    SciTech Connect

    Kumar, Sanjeev; Huber, Marcus J.; Cohen, Philip R.; McGee, David R. )

    2001-12-01

    Conversation protocols are meant to achieve certain tasks or to bring about certain state of affairs in the world. Therefore, one may identify the landmarks or the state of affairs that must be brought about during the execution of a protocol in order to achieve its goal. Accordingly, the most important aspect of protocols is these landmarks rather than the communicative actions needed to achieve the landmarks. We show that families of conversation protocols can be expressed formally as partially ordered landmarks where each landmark is characterized by propositions that are true in the state represented by that landmark. Dialogue in natural languages is regarded as joint activity. Conversation protocols in multi-agent systems are treated as dialogue templates and are composed using speech acts from natural language dialogues. As such, we treat conversation protocols as joint action expressions and gainfully apply existing formal theories of dialogue, specifically the Joint Intention Theory, to protocols and their compositions. Conversation protocols may require agents to communicate with groups as well as individuals. However, most contemporary agent communication languages, notably FIPA and KQML, have either no provision or no well-defined semantics for group communication. Furthermore, the research on protocols so far does not correctly incorporate groups into the protocols. We give a formal semantics to group communicative acts and use it to handle group communication in a formal treatment of protocols.

  1. 41 CFR 105-68.740 - Are suspension proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Are suspension proceedings formal? 105-68.740 Section 105-68.740 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION Regional Offices-General...

  2. 5 CFR 919.740 - Are suspension proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Are suspension proceedings formal? 919.740 Section 919.740 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... your representative must submit any documentary evidence you want the suspending official to consider....

  3. 2 CFR 180.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Are debarment proceedings formal? 180.835 Section 180.835 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS... the decision whether to debar. (b) You or your representative must submit any documentary evidence...

  4. 2 CFR 180.740 - Are suspension proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Are suspension proceedings formal? 180.740 Section 180.740 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS... suspension decision. (b) You as a respondent or your representative must submit any documentary evidence...

  5. 41 CFR 105-68.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Are debarment proceedings formal? 105-68.835 Section 105-68.835 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION Regional Offices-General...

  6. 5 CFR 919.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Are debarment proceedings formal? 919.835 Section 919.835 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE...) You or your representative must submit any documentary evidence you want the debarring official...

  7. Formal and Informal Academic Language Socialization of a Bilingual Child

    ERIC Educational Resources Information Center

    Cho, Hyonsuk

    2016-01-01

    This ethnographic case study examines a bilingual child's academic socialization in both formal and informal academic communities. The study follows a high-achieving, bilingual student in a public US elementary school, who paradoxically is seen as a slow learner in her Korean-American Sunday school. From the academic socialization and community of…

  8. Improving Children's Formal Word Definitions: A Feasibility Study

    ERIC Educational Resources Information Center

    Marinellie, Sally A.

    2010-01-01

    The ability to define a word with accuracy and precision is an important skill that has been associated with academic achievement. This study investigated the feasibility of conducting a lesson on formal word definitions to improve children's definitional production. The participants were 18 children in grade 4 (mean age: 9 years; 8 months) who…

  9. Blending Student Technology Experiences in Formal and Informal Learning

    ERIC Educational Resources Information Center

    Lai, K.-W.; Khaddage, F.; Knezek, Gerald

    2013-01-01

    In this article, we discuss the importance of recognizing students' technology-enhanced informal learning experiences and develop pedagogies to connect students' formal and informal learning experiences, in order to meet the demands of the knowledge society. The Mobile-Blended Collaborative Learning model is proposed as a framework to…

  10. Formal Mate Selection Networks in the United States.

    ERIC Educational Resources Information Center

    Jedlicka, Davor

    1980-01-01

    Mate selection barriers beyond individuals' control are presented as reasons for development of formal mate selection networks. Network processes are described and classified according to the degree of third-party involvement and the degree to which anonymity of participants is protected. (Author)

  11. The Role of Students' Emotions in Formal Feedback Situations

    ERIC Educational Resources Information Center

    Varlander, Sara

    2008-01-01

    A growing, but still relatively small body of research underscores the importance of attending to students' experiences and emotions in higher education. One specific context in which emotions have a focal role is formal feedback situations. The aim of this paper is to provide a literature overview on the role of emotions, in sociology in general…

  12. The Formalization of the University: Rules, Roots, and Routes

    ERIC Educational Resources Information Center

    Ramirez, Francisco O.; Christensen, Tom

    2013-01-01

    This article examines changes in the formal organization of two universities and two schools within these universities, the University of Oslo and Stanford University. We focus on role differentiation, rule formation, and resource seeking structures and describe organizational developments along these dimensions. We find that both these…

  13. 7 CFR 1726.201 - Formal competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., as described in 7 CFR 1726.201, were followed in awarding this contract.” The certification executed... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal... taking any other action necessary to procure full, free and competitive bidding. The borrower should...

  14. Recognising Women's Skill. EAE647 Non-Formal Learning.

    ERIC Educational Resources Information Center

    Cox, Eva; Leonard, Helen

    The material in this monograph is part of the study materials for the one-semester distance education unit, Non-Formal Learning, in the Open Campus Program at Deakin University (Australia). It is designed to raise issues relating to skill definition. "Choosing a Worker or How Good Are Your Job Descriptions?" explores why interpersonal or…

  15. Communication and Ethics: The Informal and Formal Curricula.

    ERIC Educational Resources Information Center

    Cooper, Thomas W.

    1987-01-01

    Noting that humans are educated more by than about the mass media, this paper argues that modern society has produced an informal (mediated) ethics curriculum which may be more powerful than the formal (institutionally educational) curriculum developed by academics and administrators. It first examines the informal curriculum, listing statistics…

  16. Structuring Formal Control Systems Specifications for Reuse: Surviving Hardware Changes

    NASA Technical Reports Server (NTRS)

    Thompson, Jeffrey M.; Heimdahl, Mats P. E.; Erickson, Debra M.

    2000-01-01

    Formal capture and analysis of the required behavior of control systems have many advantages. For instance, it encourages rigorous requirements analysis, the required behavior is unambiguously defined, and we can assure that various safety properties are satisfied. Formal modeling is, however, a costly and time consuming process and if one could reuse the formal models over a family of products, significant cost savings would be realized. In an ongoing project we are investigating how to structure state-based models to achieve a high level of reusability within product families. In this paper we discuss a high-level structure of requirements models that achieves reusability of the desired control behavior across varying hardware platforms in a product family. The structuring approach is demonstrated through a case study in the mobile robotics domain where the desired robot behavior is reused on two diverse platforms-one commercial mobile platform and one build in-house. We use our language RSML (-e) to capture the control behavior for reuse and our tool NIMBUS to demonstrate how the formal specification can be validated and used as a prototype on the two platforms.

  17. 50 CFR 402.16 - Reinitiation of formal consultation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.16 Reinitiation of formal... statement is exceeded; (b) If new information reveals effects of the action that may affect listed...

  18. Spacetime path formalism for massive particles of any spin

    NASA Astrophysics Data System (ADS)

    Seidewitz, Ed

    2009-02-01

    Earlier work presented spacetime path formalism for relativistic quantum mechanics arising naturally from the fundamental principles of the Born probability rule, superposition, and spacetime translation invariance. The resulting formalism can be seen as a foundation for a number of previous parametrized approaches to relativistic quantum mechanics in the literature. Because time is treated similarly to the three-space coordinates, rather than as an evolution parameter, such approaches have proved particularly useful in the study of quantum gravity and cosmology. The present paper extends the foundational spacetime path formalism to include massive, non-scalar particles of any (integer or half-integer) spin. This is done by generalizing the principle of translational invariance used in the scalar case to the principle of full Poincaré invariance, leading to a formulation for the non-scalar propagator in terms of a path integral over the Poincaré group. Once the difficulty of the non-compactness of the component Lorentz group is dealt with, the subsequent development is remarkably parallel to the scalar case. This allows the formalism to retain a clear probabilistic interpretation throughout, with a natural reduction to non-relativistic quantum mechanics closely related to the well-known generalized Foldy-Wouthuysen transformation.

  19. Improving Project Management Using Formal Models and Architectures

    NASA Technical Reports Server (NTRS)

    Kahn, Theodore; Sturken, Ian

    2011-01-01

    This talk discusses the advantages formal modeling and architecture brings to project management. These emerging technologies have both great potential and challenges for improving information available for decision-making. The presentation covers standards, tools and cultural issues needing consideration, and includes lessons learned from projects the presenters have worked on.

  20. Formal Computer Validation of the Quantum Phase Estimation Algorithm

    NASA Astrophysics Data System (ADS)

    Witzel, Wayne; Rudinger, Kenneth; Sarovar, Mohan; Carr, Robert

    While peer review and scientific consensus provide some assurance to the validity of ideas, people do make mistakes that can slip through the cracks. A plethora of formal methods tools exist and are in use in a variety of settings where high assurance is demanded. Existing tools, however, require a great deal of expertise and lack versatility, demanding a non-trivial translation between a high-level description of a problem and the formal system. Our software, called Prove-It, allows a nearly direct translation between human-recognizable formulations and the underlying formal system. While Prove-It is not designed for particularly efficient automation, a primary goal of other formal methods tools, it is extremely flexible in following a desired line of reasoning (proof structure). This approach is particularly valuable for validating proofs that are already known. We will demonstrate a validation of the Quantum Phase Estimation Algorithm using Prove-It. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories.

  1. Recognition of Emotions in Autism: A Formal Meta-Analysis

    ERIC Educational Resources Information Center

    Uljarevic, Mirko; Hamilton, Antonia

    2013-01-01

    Determining the integrity of emotion recognition in autistic spectrum disorder is important to our theoretical understanding of autism and to teaching social skills. Previous studies have reported both positive and negative results. Here, we take a formal meta-analytic approach, bringing together data from 48 papers testing over 980 participants…

  2. Prayer and Adolescence: Can Formal Instruction Make a Difference?

    ERIC Educational Resources Information Center

    Sigel, Deena

    2016-01-01

    This design experiment in prayer education for Jewish students was motivated by a current educational concern: educating for spirituality and religious practice. Educators are tasked with formally nurturing spirituality (Wright 2001). It is known that attitude to religious observance may change during adolescence (Hyde 1963), thus attitude to…

  3. Spacetime path formalism for massive particles of any spin

    SciTech Connect

    Seidewitz, Ed

    2009-02-15

    Earlier work presented spacetime path formalism for relativistic quantum mechanics arising naturally from the fundamental principles of the Born probability rule, superposition, and spacetime translation invariance. The resulting formalism can be seen as a foundation for a number of previous parametrized approaches to relativistic quantum mechanics in the literature. Because time is treated similarly to the three-space coordinates, rather than as an evolution parameter, such approaches have proved particularly useful in the study of quantum gravity and cosmology. The present paper extends the foundational spacetime path formalism to include massive, non-scalar particles of any (integer or half-integer) spin. This is done by generalizing the principle of translational invariance used in the scalar case to the principle of full Poincare invariance, leading to a formulation for the non-scalar propagator in terms of a path integral over the Poincare group. Once the difficulty of the non-compactness of the component Lorentz group is dealt with, the subsequent development is remarkably parallel to the scalar case. This allows the formalism to retain a clear probabilistic interpretation throughout, with a natural reduction to non-relativistic quantum mechanics closely related to the well-known generalized Foldy-Wouthuysen transformation.

  4. 39 CFR 3001.72 - Filing of formal requests.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Requests for Changes in the Nature of Postal Services § 3001.72 Filing of formal requests. Whenever the... in the nature of postal services subject to this subpart, the Postal Service shall file with the... Postal Service proposes to make effective the change in the nature of postal services involved. Within...

  5. FORMAL AND ON-THE JOB TRAINING IN MILITARY OCCUPATIONS.

    ERIC Educational Resources Information Center

    BATEMAN, C.W.

    A MODEL IS CONSTRUCTED TO DETERMINE THE BEST PROPORTION OF FORMAL AND ON-THE-JOB TRAINING IN MILITARY OCCUPATIONS. SPECIAL CONSIDERATION IS GIVEN TO THE UNIQUE SITUATION OF ENLISTED PERSONNEL'S FIXED LENGTH OF SERVICE, THE SMALL PERCENTAGE OF RE-ENLISTMENT, AND THE NECESSITY OF TRAINING ALL ENLISTEES FOR ASSIGNED OCCUPATIONS. THE MODEL FORMULA…

  6. The Lessons of Non-Formal Learning for Urban Youth

    ERIC Educational Resources Information Center

    Thompson, Carol C.

    2012-01-01

    Non-formal learning for urban youth has a long history in the United States; it remains a source of innovation. This essay draws on literature about organizations that use community ties to encourage cognitive development and identity formation. It then describes how one youth organization in Camden, New Jersey uses presentations to the community…

  7. Formalization, Conflict, and Change: Constructive and Destructive Consequences in Schools.

    ERIC Educational Resources Information Center

    DiPaola, Michael F.; Hoy, Wayne K.

    2001-01-01

    Describes a typology of change drawn from conceptualizing conflict as cognitive or affective, and organizational formalization in terms of enabling or coercive procedures. The framework can predict the impact of change, from situations that catalyze and facilitate change to those that frustrate and inhibit it. Summarizes key factors for school…

  8. The Slow Death of Formal Learning: A Polemic

    ERIC Educational Resources Information Center

    McGuire, David; Gubbins, Claire

    2010-01-01

    Over recent years, approaches to education and training have become more informal, situated, outcome focused and experiential. Within this context, formal learning now plays a greatly diminished role, being supplanted by activity-based and technologically-based learning. This article, structured in the form of a polemic challenges readers to…

  9. 7 CFR 1.23 - Records in formal adjudication proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Records in formal adjudication proceedings. 1.23 Section 1.23 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official... Agriculture, Washington, DC 20250, and shall be made available to the public....

  10. 7 CFR 1.23 - Records in formal adjudication proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Records in formal adjudication proceedings. 1.23 Section 1.23 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official... Agriculture, Washington, DC 20250, and shall be made available to the public....

  11. Parental Involvement Practices in Formalized Home-School Cooperation

    ERIC Educational Resources Information Center

    Baeck, Unn-Doris Karlsen

    2010-01-01

    The topic for this article is parents' participation and willingness to participate in formalized home-school cooperation. The analyses are based on a nationwide survey among parents in lower secondary schools in Norway. A main finding is that parental involvement practices differ according to parents' level of education in the sense that parents…

  12. Formal Teacher Competence and Its Effect on Pupil Reading Achievement

    ERIC Educational Resources Information Center

    Johansson, Stefan; Myrberg, Eva; Rosén, Monica

    2015-01-01

    The main aim of this study was to investigate the impact of formal teacher competence on pupils' reading achievement. The data comes from the Swedish participation in PIRLS 2001 in grade 3. Information was obtained from pupils (n = 5271) and teachers (n = 351). The analyses were conducted using 2-level structural equation modeling. Teacher…

  13. 49 CFR 1111.1 - Content of formal complaints; joinder.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... available pursuant to 49 CFR part 1108, the complaint shall state that arbitration was considered, but... their case should follow the procedures set forth at 49 CFR 1244.8. ... 49 Transportation 8 2012-10-01 2012-10-01 false Content of formal complaints; joinder....

  14. 49 CFR 1111.1 - Content of formal complaints; joinder.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... available pursuant to 49 CFR part 1108, the complaint shall state that arbitration was considered, but... their case should follow the procedures set forth at 49 CFR 1244.8. ... 49 Transportation 8 2013-10-01 2013-10-01 false Content of formal complaints; joinder....

  15. Informal and Formal Kinship Care Populations: A Study in Contrasts.

    ERIC Educational Resources Information Center

    McLean, Beth; Thomas, Rebecca

    1996-01-01

    Contrasts a group of informal kinship care providers in Philadelphia (KIDS'n'KIN Program) with two "formal" kinship care groups in Baltimore and California, examining similarities and differences in child and caregiver demographies and service needs. Presents the program's response to the needs of informal kinship care providers. (Author/SD)

  16. Non-Formal Educator Use of Evaluation Results

    ERIC Educational Resources Information Center

    Baughman, Sarah; Boyd, Heather H.; Franz, Nancy K.

    2012-01-01

    Increasing demands for accountability in educational programming have resulted in increasing calls for program evaluation in educational organizations. Many organizations include conducting program evaluations as part of the job responsibilities of program staff. Cooperative Extension is a complex organization offering non-formal educational…

  17. School in the Park: Bridging Formal and Informal Learning Environments

    ERIC Educational Resources Information Center

    Mathison, Carla; Wachowiak, Susan; Feldman, Linda

    2007-01-01

    In San Diego, California, 800 public school students from the inner city are attending a program called School in the Park (SITP), for approximately one-fourth of their 3rd-, 4th-, and 5th-grade education. This unique program blends rigorous academic standards (formal learning) with hands-on, experiential curricula (informal learning), using…

  18. The Rural Hospice: Integrating Formal and Informal Helping Systems.

    ERIC Educational Resources Information Center

    Jenkins, Lowell; Cook, Alicia S.

    1981-01-01

    Describes the implementation of the hospice philosophy in rural areas and provides a model of how formal helping systems and natural helping networks can work together effectively. Suggests the emergence of the hospice can reorient social workers to the basic concepts of helping. (Author/JAC)

  19. Formal design review report project W-151 mixer pump procurement

    SciTech Connect

    Crass, D.W.

    1997-01-21

    A formal design review for WHC-S-0040 was held on January 21, 1993. The review was completed January 29, 1993. No outstanding action items existed. Comments were recorded on Record Comment Record (RCR) forms and incorporated into the specification. The specification was considered acceptable, approved and issued as WHC-S-0040, Rev. 0 on March 4, 1993.

  20. A Survey of Library Support for Formal Undergraduate Research Programs

    ERIC Educational Resources Information Center

    Hensley, Merinda Kaye; Shreeves, Sarah L.; Davis-Kahl, Stephanie

    2014-01-01

    Undergraduate research is defined by the Council on Undergraduate Research (CUR) as "an inquiry or investigation conducted by an undergraduate student that makes an original intellectual or creative contribution to the discipline." This study serves as a snapshot of current library practices in relation to formal undergraduate research…