Sample records for direct integration method

  1. Structural reliability calculation method based on the dual neural network and direct integration method.

    PubMed

    Li, Haibin; He, Yun; Nie, Xiaobo

    2018-01-01

    Structural reliability analysis under uncertainty is paid wide attention by engineers and scholars due to reflecting the structural characteristics and the bearing actual situation. The direct integration method, started from the definition of reliability theory, is easy to be understood, but there are still mathematics difficulties in the calculation of multiple integrals. Therefore, a dual neural network method is proposed for calculating multiple integrals in this paper. Dual neural network consists of two neural networks. The neural network A is used to learn the integrand function, and the neural network B is used to simulate the original function. According to the derivative relationships between the network output and the network input, the neural network B is derived from the neural network A. On this basis, the performance function of normalization is employed in the proposed method to overcome the difficulty of multiple integrations and to improve the accuracy for reliability calculations. The comparisons between the proposed method and Monte Carlo simulation method, Hasofer-Lind method, the mean value first-order second moment method have demonstrated that the proposed method is an efficient and accurate reliability method for structural reliability problems.

  2. A robust direct-integration method for rotorcraft maneuver and periodic response

    NASA Technical Reports Server (NTRS)

    Panda, Brahmananda

    1992-01-01

    The Newmark-Beta method and the Newton-Raphson iteration scheme are combined to develop a direct-integration method for evaluating the maneuver and periodic-response expressions for rotorcraft. The method requires the generation of Jacobians and includes higher derivatives in the formulation of the geometric stiffness matrix to enhance the convergence of the system. The method leads to effective convergence with nonlinear structural dynamics and aerodynamic terms. Singularities in the matrices can be addressed with the method as they arise from a Lagrange multiplier approach for coupling equations with nonlinear constraints. The method is also shown to be general enough to handle singularities from quasisteady control-system models. The method is shown to be more general and robust than the similar 2GCHAS method for analyzing rotorcraft dynamics.

  3. Direction and Integration of Experimental Ground Test Capabilities and Computational Methods

    NASA Technical Reports Server (NTRS)

    Dunn, Steven C.

    2016-01-01

    This paper groups and summarizes the salient points and findings from two AIAA conference panels targeted at defining the direction, with associated key issues and recommendations, for the integration of experimental ground testing and computational methods. Each panel session utilized rapporteurs to capture comments from both the panel members and the audience. Additionally, a virtual panel of several experts were consulted between the two sessions and their comments were also captured. The information is organized into three time-based groupings, as well as by subject area. These panel sessions were designed to provide guidance to both researchers/developers and experimental/computational service providers in defining the future of ground testing, which will be inextricably integrated with the advancement of computational tools.

  4. Viewing-zone control of integral imaging display using a directional projection and elemental image resizing method.

    PubMed

    Alam, Md Ashraful; Piao, Mei-Lan; Bang, Le Thanh; Kim, Nam

    2013-10-01

    Viewing-zone control of integral imaging (II) displays using a directional projection and elemental image (EI) resizing method is proposed. Directional projection of EIs with the same size of microlens pitch causes an EI mismatch at the EI plane. In this method, EIs are generated computationally using a newly introduced algorithm: the directional elemental image generation and resizing algorithm considering the directional projection geometry of each pixel as well as an EI resizing method to prevent the EI mismatch. Generated EIs are projected as a collimated projection beam with a predefined directional angle, either horizontally or vertically. The proposed II display system allows reconstruction of a 3D image within a predefined viewing zone that is determined by the directional projection angle.

  5. Statistical Methods in Integrative Genomics

    PubMed Central

    Richardson, Sylvia; Tseng, George C.; Sun, Wei

    2016-01-01

    Statistical methods in integrative genomics aim to answer important biology questions by jointly analyzing multiple types of genomic data (vertical integration) or aggregating the same type of data across multiple studies (horizontal integration). In this article, we introduce different types of genomic data and data resources, and then review statistical methods of integrative genomics, with emphasis on the motivation and rationale of these methods. We conclude with some summary points and future research directions. PMID:27482531

  6. An exterior Poisson solver using fast direct methods and boundary integral equations with applications to nonlinear potential flow

    NASA Technical Reports Server (NTRS)

    Young, D. P.; Woo, A. C.; Bussoletti, J. E.; Johnson, F. T.

    1986-01-01

    A general method is developed combining fast direct methods and boundary integral equation methods to solve Poisson's equation on irregular exterior regions. The method requires O(N log N) operations where N is the number of grid points. Error estimates are given that hold for regions with corners and other boundary irregularities. Computational results are given in the context of computational aerodynamics for a two-dimensional lifting airfoil. Solutions of boundary integral equations for lifting and nonlifting aerodynamic configurations using preconditioned conjugate gradient are examined for varying degrees of thinness.

  7. Recent Advances in the Method of Forces: Integrated Force Method of Structural Analysis

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Coroneos, Rula M.; Hopkins, Dale A.

    1998-01-01

    Stress that can be induced in an elastic continuum can be determined directly through the simultaneous application of the equilibrium equations and the compatibility conditions. In the literature, this direct stress formulation is referred to as the integrated force method. This method, which uses forces as the primary unknowns, complements the popular equilibrium-based stiffness method, which considers displacements as the unknowns. The integrated force method produces accurate stress, displacement, and frequency results even for modest finite element models. This version of the force method should be developed as an alternative to the stiffness method because the latter method, which has been researched for the past several decades, may have entered its developmental plateau. Stress plays a primary role in the development of aerospace and other products, and its analysis is difficult. Therefore, it is advisable to use both methods to calculate stress and eliminate errors through comparison. This paper examines the role of the integrated force method in analysis, animation and design.

  8. Transient Response of Shells of Revolution by Direct Integration and Modal Superposition Methods

    NASA Technical Reports Server (NTRS)

    Stephens, W. B.; Adelman, H. M.

    1974-01-01

    The results of an analytical effort to obtain and evaluate transient response data for a cylindrical and a conical shell by use of two different approaches: direct integration and modal superposition are described. The inclusion of nonlinear terms is more important than the inclusion of secondary linear effects (transverse shear deformation and rotary inertia) although there are thin-shell structures where these secondary effects are important. The advantages of the direct integration approach are that geometric nonlinear and secondary effects are easy to include and high-frequency response may be calculated. In comparison to the modal superposition technique the computer storage requirements are smaller. The advantages of the modal superposition approach are that the solution is independent of the previous time history and that once the modal data are obtained, the response for repeated cases may be efficiently computed. Also, any admissible set of initial conditions can be applied.

  9. The Direct Lighting Computation in Global Illumination Methods

    NASA Astrophysics Data System (ADS)

    Wang, Changyaw Allen

    1994-01-01

    Creating realistic images is a computationally expensive process, but it is very important for applications such as interior design, product design, education, virtual reality, and movie special effects. To generate realistic images, state-of-art rendering techniques are employed to simulate global illumination, which accounts for the interreflection of light among objects. In this document, we formalize the global illumination problem into a eight -dimensional integral and discuss various methods that can accelerate the process of approximating this integral. We focus on the direct lighting computation, which accounts for the light reaching the viewer from the emitting sources after exactly one reflection, Monte Carlo sampling methods, and light source simplification. Results include a new sample generation method, a framework for the prediction of the total number of samples used in a solution, and a generalized Monte Carlo approach for computing the direct lighting from an environment which for the first time makes ray tracing feasible for highly complex environments.

  10. Parallel/Vector Integration Methods for Dynamical Astronomy

    NASA Astrophysics Data System (ADS)

    Fukushima, T.

    Progress of parallel/vector computers has driven us to develop suitable numerical integrators utilizing their computational power to the full extent while being independent on the size of system to be integrated. Unfortunately, the parallel version of Runge-Kutta type integrators are known to be not so efficient. Recently we developed a parallel version of the extrapolation method (Ito and Fukushima 1997), which allows variable timesteps and still gives an acceleration factor of 3-4 for general problems. While the vector-mode usage of Picard-Chebyshev method (Fukushima 1997a, 1997b) will lead the acceleration factor of order of 1000 for smooth problems such as planetary/satellites orbit integration. The success of multiple-correction PECE mode of time-symmetric implicit Hermitian integrator (Kokubo 1998) seems to enlighten Milankar's so-called "pipelined predictor corrector method", which is expected to lead an acceleration factor of 3-4. We will review these directions and discuss future prospects.

  11. Can we estimate total magnetization directions from aeromagnetic data using Helbig's integrals?

    USGS Publications Warehouse

    Phillips, J.D.

    2005-01-01

    An algorithm that implements Helbig's (1963) integrals for estimating the vector components (mx, my, mz) of tile magnetic dipole moment from the first order moments of the vector magnetic field components (??X, ??Y, ??Z) is tested on real and synthetic data. After a grid of total field aeromagnetic data is converted to vector component grids using Fourier filtering, Helbig's infinite integrals are evaluated as finite integrals in small moving windows using a quadrature algorithm based on the 2-D trapezoidal rule. Prior to integration, best-fit planar surfaces must be removed from the component data within the data windows in order to make the results independent of the coordinate system origin. Two different approaches are described for interpreting the results of the integration. In the "direct" method, results from pairs of different window sizes are compared to identify grid nodes where the angular difference between solutions is small. These solutions provide valid estimates of total magnetization directions for compact sources such as spheres or dipoles, but not for horizontally elongated or 2-D sources. In the "indirect" method, which is more forgiving of source geometry, results of the quadrature analysis are scanned for solutions that are parallel to a specified total magnetization direction.

  12. Real-space finite-difference approach for multi-body systems: path-integral renormalization group method and direct energy minimization method.

    PubMed

    Sasaki, Akira; Kojo, Masashi; Hirose, Kikuji; Goto, Hidekazu

    2011-11-02

    The path-integral renormalization group and direct energy minimization method of practical first-principles electronic structure calculations for multi-body systems within the framework of the real-space finite-difference scheme are introduced. These two methods can handle higher dimensional systems with consideration of the correlation effect. Furthermore, they can be easily extended to the multicomponent quantum systems which contain more than two kinds of quantum particles. The key to the present methods is employing linear combinations of nonorthogonal Slater determinants (SDs) as multi-body wavefunctions. As one of the noticeable results, the same accuracy as the variational Monte Carlo method is achieved with a few SDs. This enables us to study the entire ground state consisting of electrons and nuclei without the need to use the Born-Oppenheimer approximation. Recent activities on methodological developments aiming towards practical calculations such as the implementation of auxiliary field for Coulombic interaction, the treatment of the kinetic operator in imaginary-time evolutions, the time-saving double-grid technique for bare-Coulomb atomic potentials and the optimization scheme for minimizing the total-energy functional are also introduced. As test examples, the total energy of the hydrogen molecule, the atomic configuration of the methylene and the electronic structures of two-dimensional quantum dots are calculated, and the accuracy, availability and possibility of the present methods are demonstrated.

  13. A new method for calculating differential distributions directly in Mellin space

    NASA Astrophysics Data System (ADS)

    Mitov, Alexander

    2006-12-01

    We present a new method for the calculation of differential distributions directly in Mellin space without recourse to the usual momentum-fraction (or z-) space. The method is completely general and can be applied to any process. It is based on solving the integration-by-parts identities when one of the powers of the propagators is an abstract number. The method retains the full dependence on the Mellin variable and can be implemented in any program for solving the IBP identities based on algebraic elimination, like Laporta. General features of the method are: (1) faster reduction, (2) smaller number of master integrals compared to the usual z-space approach and (3) the master integrals satisfy difference instead of differential equations. This approach generalizes previous results related to fully inclusive observables like the recently calculated three-loop space-like anomalous dimensions and coefficient functions in inclusive DIS to more general processes requiring separate treatment of the various physical cuts. Many possible applications of this method exist, the most notable being the direct evaluation of the three-loop time-like splitting functions in QCD.

  14. Time-integrated directional detection of dark matter

    NASA Astrophysics Data System (ADS)

    O'Hare, Ciaran A. J.; Kavanagh, Bradley J.; Green, Anne M.

    2017-10-01

    The analysis of signals in directional dark matter (DM) detectors typically assumes that the directions of nuclear recoils can be measured in the Galactic rest frame. However, this is not possible with all directional detection technologies. In nuclear emulsions, for example, the recoil events must be detected and measured after the exposure time of the experiment. Unless the entire detector is mounted and rotated with the sidereal day, the recoils cannot be reoriented in the Galactic rest frame. We examine the effect of this "time integration" on the primary goals of directional detection, namely: (1) confirming that the recoils are anisotropic; (2) measuring the median recoil direction to confirm their Galactic origin; and (3) probing below the neutrino floor. We show that after time integration the DM recoil distribution retains a preferred direction and is distinct from that of Solar neutrino-induced recoils. Many of the advantages of directional detection are therefore preserved and it is not crucial to mount and rotate the detector. Rejecting isotropic backgrounds requires a factor of 2 more signal events compared with an experiment with event time information, whereas a factor of 1.5-3 more events are needed to measure a median direction in agreement with the expectation for DM. We also find that there is still effectively no neutrino floor in a time-integrated directional experiment. However to reach a cross section an order of magnitude below the floor, a factor of ˜8 larger exposure is required than with a conventional directional experiment. We also examine how the sensitivity is affected for detectors with only 2D recoil track readout, and/or no head-tail measurement. As for non-time-integrated experiments, 2D readout is not a major disadvantage, though a lack of head-tail sensitivity is.

  15. Integrating high dimensional bi-directional parsing models for gene mention tagging.

    PubMed

    Hsu, Chun-Nan; Chang, Yu-Ming; Kuo, Cheng-Ju; Lin, Yu-Shi; Huang, Han-Shen; Chung, I-Fang

    2008-07-01

    Tagging gene and gene product mentions in scientific text is an important initial step of literature mining. In this article, we describe in detail our gene mention tagger participated in BioCreative 2 challenge and analyze what contributes to its good performance. Our tagger is based on the conditional random fields model (CRF), the most prevailing method for the gene mention tagging task in BioCreative 2. Our tagger is interesting because it accomplished the highest F-scores among CRF-based methods and second over all. Moreover, we obtained our results by mostly applying open source packages, making it easy to duplicate our results. We first describe in detail how we developed our CRF-based tagger. We designed a very high dimensional feature set that includes most of information that may be relevant. We trained bi-directional CRF models with the same set of features, one applies forward parsing and the other backward, and integrated two models based on the output scores and dictionary filtering. One of the most prominent factors that contributes to the good performance of our tagger is the integration of an additional backward parsing model. However, from the definition of CRF, it appears that a CRF model is symmetric and bi-directional parsing models will produce the same results. We show that due to different feature settings, a CRF model can be asymmetric and the feature setting for our tagger in BioCreative 2 not only produces different results but also gives backward parsing models slight but constant advantage over forward parsing model. To fully explore the potential of integrating bi-directional parsing models, we applied different asymmetric feature settings to generate many bi-directional parsing models and integrate them based on the output scores. Experimental results show that this integrated model can achieve even higher F-score solely based on the training corpus for gene mention tagging. Data sets, programs and an on-line service of our gene

  16. Technical Note: A direct ray-tracing method to compute integral depth dose in pencil beam proton radiography with a multilayer ionization chamber.

    PubMed

    Farace, Paolo; Righetto, Roberto; Deffet, Sylvain; Meijers, Arturs; Vander Stappen, Francois

    2016-12-01

    To introduce a fast ray-tracing algorithm in pencil proton radiography (PR) with a multilayer ionization chamber (MLIC) for in vivo range error mapping. Pencil beam PR was obtained by delivering spots uniformly positioned in a square (45 × 45 mm 2 field-of-view) of 9 × 9 spots capable of crossing the phantoms (210 MeV). The exit beam was collected by a MLIC to sample the integral depth dose (IDD MLIC ). PRs of an electron-density and of a head phantom were acquired by moving the couch to obtain multiple 45 × 45 mm 2 frames. To map the corresponding range errors, the two-dimensional set of IDD MLIC was compared with (i) the integral depth dose computed by the treatment planning system (TPS) by both analytic (IDD TPS ) and Monte Carlo (IDD MC ) algorithms in a volume of water simulating the MLIC at the CT, and (ii) the integral depth dose directly computed by a simple ray-tracing algorithm (IDD direct ) through the same CT data. The exact spatial position of the spot pattern was numerically adjusted testing different in-plane positions and selecting the one that minimized the range differences between IDD direct and IDD MLIC . Range error mapping was feasible by both the TPS and the ray-tracing methods, but very sensitive to even small misalignments. In homogeneous regions, the range errors computed by the direct ray-tracing algorithm matched the results obtained by both the analytic and the Monte Carlo algorithms. In both phantoms, lateral heterogeneities were better modeled by the ray-tracing and the Monte Carlo algorithms than by the analytic TPS computation. Accordingly, when the pencil beam crossed lateral heterogeneities, the range errors mapped by the direct algorithm matched better the Monte Carlo maps than those obtained by the analytic algorithm. Finally, the simplicity of the ray-tracing algorithm allowed to implement a prototype procedure for automated spatial alignment. The ray-tracing algorithm can reliably replace the TPS method in MLIC PR for in

  17. Integrability: mathematical methods for studying solitary waves theory

    NASA Astrophysics Data System (ADS)

    Wazwaz, Abdul-Majid

    2014-03-01

    real features in a variety of vital areas in science, technology and engineering. In recognition of the importance of solitary waves theory and the underlying concept of integrable equations, a variety of powerful methods have been developed to carry out the required analysis. Examples of such methods which have been advanced are the inverse scattering method, the Hirota bilinear method, the simplified Hirota method, the Bäcklund transformation method, the Darboux transformation, the Pfaffian technique, the Painlevé analysis, the generalized symmetry method, the subsidiary ordinary differential equation method, the coupled amplitude-phase formulation, the sine-cosine method, the sech-tanh method, the mapping and deformation approach and many new other methods. The inverse scattering method, viewed as a nonlinear analogue of the Fourier transform method, is a powerful approach that demonstrates the existence of soliton solutions through intensive computations. At the center of the theory of integrable equations lies the bilinear forms and Hirota's direct method, which can be used to obtain soliton solutions by using exponentials. The Bäcklund transformation method is a useful invariant transformation that transforms one solution into another of a differential equation. The Darboux transformation method is a well known tool in the theory of integrable systems. It is believed that there is a connection between the Bäcklund transformation and the Darboux transformation, but it is as yet not known. Archetypes of integrable equations are the Korteweg-de Vries (KdV) equation, the modified KdV equation, the sine-Gordon equation, the Schrödinger equation, the Vakhnenko equation, the KdV6 equation, the Burgers equation, the fifth-order Lax equation and many others. These equations yield soliton solutions, multiple soliton solutions, breather solutions, quasi-periodic solutions, kink solutions, homo-clinic solutions and other solutions as well. The couplings of linear and

  18. Boundary-integral methods in elasticity and plasticity. [solutions of boundary value problems

    NASA Technical Reports Server (NTRS)

    Mendelson, A.

    1973-01-01

    Recently developed methods that use boundary-integral equations applied to elastic and elastoplastic boundary value problems are reviewed. Direct, indirect, and semidirect methods using potential functions, stress functions, and displacement functions are described. Examples of the use of these methods for torsion problems, plane problems, and three-dimensional problems are given. It is concluded that the boundary-integral methods represent a powerful tool for the solution of elastic and elastoplastic problems.

  19. A direct-inverse method for transonic and separated flows about airfoils

    NASA Technical Reports Server (NTRS)

    Carlson, K. D.

    1985-01-01

    A direct-inverse technique and computer program called TAMSEP that can be sued for the analysis of the flow about airfoils at subsonic and low transonic freestream velocities is presented. The method is based upon a direct-inverse nonconservative full potential inviscid method, a Thwaites laminar boundary layer technique, and the Barnwell turbulent momentum integral scheme; and it is formulated using Cartesian coordinates. Since the method utilizes inverse boundary conditions in regions of separated flow, it is suitable for predicing the flowfield about airfoils having trailing edge separated flow under high lift conditions. Comparisons with experimental data indicate that the method should be a useful tool for applied aerodynamic analyses.

  20. A direct-inverse method for transonic and separated flows about airfoils

    NASA Technical Reports Server (NTRS)

    Carlson, Leland A.

    1990-01-01

    A direct-inverse technique and computer program called TAMSEP that can be used for the analysis of the flow about airfoils at subsonic and low transonic freestream velocities is presented. The method is based upon a direct-inverse nonconservative full potential inviscid method, a Thwaites laminar boundary layer technique, and the Barnwell turbulent momentum integral scheme; and it is formulated using Cartesian coordinates. Since the method utilizes inverse boundary conditions in regions of separated flow, it is suitable for predicting the flow field about airfoils having trailing edge separated flow under high lift conditions. Comparisons with experimental data indicate that the method should be a useful tool for applied aerodynamic analyses.

  1. Integrated test plan for directional boring

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Volk, B.W.

    This integrated test plan describes the field testing of the DITCH WITCH Directional Boring System. DITCH WITCH is a registered trademark of The Charles Machine Works, Inc., Perry, Oklahoma. The test is being conducted as a coordinated effort between Charles Machine Works (CMW), Sandia National Laboratories (SNL), and the Westinghouse Hanford Company (WHC). Funding for the WHC portion of the project is through the Volatile Organic Compound-Arid Integrated Demonstration (VOC-Arid ID). The purpose of the test is to evaluate the performance of the directional boring system for possible future use on environmental restoration projects at Hanford and other Department ofmore » Energy (DOE) sites. The test will be conducted near the 200 Areas Fire Station located between the 200 East and 200 West Area of the Hanford Site. The directional boring system will be used to drill and complete (with fiberglass casing) two horizontal boreholes. A third borehole will be drilled to test sampling equipment but will not be completed with casing.« less

  2. Criteria for quantitative and qualitative data integration: mixed-methods research methodology.

    PubMed

    Lee, Seonah; Smith, Carrol A M

    2012-05-01

    Many studies have emphasized the need and importance of a mixed-methods approach for evaluation of clinical information systems. However, those studies had no criteria to guide integration of multiple data sets. Integrating different data sets serves to actualize the paradigm that a mixed-methods approach argues; thus, we require criteria that provide the right direction to integrate quantitative and qualitative data. The first author used a set of criteria organized from a literature search for integration of multiple data sets from mixed-methods research. The purpose of this article was to reorganize the identified criteria. Through critical appraisal of the reasons for designing mixed-methods research, three criteria resulted: validation, complementarity, and discrepancy. In applying the criteria to empirical data of a previous mixed methods study, integration of quantitative and qualitative data was achieved in a systematic manner. It helped us obtain a better organized understanding of the results. The criteria of this article offer the potential to produce insightful analyses of mixed-methods evaluations of health information systems.

  3. Direct evaluation of free energy for large system through structure integration approach.

    PubMed

    Takeuchi, Kazuhito; Tanaka, Ryohei; Yuge, Koretaka

    2015-09-30

    We propose a new approach, 'structure integration', enabling direct evaluation of configurational free energy for large systems. The present approach is based on the statistical information of lattice. Through first-principles-based simulation, we find that the present method evaluates configurational free energy accurately in disorder states above critical temperature.

  4. An equivalent domain integral method for three-dimensional mixed-mode fracture problems

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Raju, I. S.

    1991-01-01

    A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

  5. An equivalent domain integral method for three-dimensional mixed-mode fracture problems

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Raju, I. S.

    1992-01-01

    A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

  6. Integrated-optical directional coupler biosensor

    NASA Astrophysics Data System (ADS)

    Luff, B. J.; Harris, R. D.; Wilkinson, J. S.; Wilson, R.; Schiffrin, D. J.

    1996-04-01

    We present measurements of biomolecular binding reactions, using a new type of integrated-optical biosensor based on a planar directional coupler structure. The device is fabricated by Ag+ - Na+ ion exchange in glass, and definition of the sensing region is achieved by use of transparent fluoropolymer isolation layers formed by thermal evaporation. The suitability of the sensor for application to the detection of environmental pollutants is considered.

  7. Integrated GNSS Attitude Determination and Positioning for Direct Geo-Referencing

    PubMed Central

    Nadarajah, Nandakumaran; Paffenholz, Jens-André; Teunissen, Peter J. G.

    2014-01-01

    Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS navigation system to provide estimates of the position and attitude (orientation) of a 3D laser scanner. The proposed multi-sensor system (MSS) consists of multiple GNSS antennas rigidly mounted on the frame of a rotating laser scanner and a reference GNSS station with known coordinates. Precise GNSS navigation requires the resolution of the carrier phase ambiguities. The proposed method uses the multivariate constrained integer least-squares (MC-LAMBDA) method for the estimation of rotating frame ambiguities and attitude angles. MC-LAMBDA makes use of the known antenna geometry to strengthen the underlying attitude model and, hence, to enhance the reliability of rotating frame ambiguity resolution and attitude determination. The reliable estimation of rotating frame ambiguities is consequently utilized to enhance the relative positioning of the rotating frame with respect to the reference station. This integrated (array-aided) method improves ambiguity resolution, as well as positioning accuracy between the rotating frame and the reference station. Numerical analyses of GNSS data from a real-data campaign confirm the improved performance of the proposed method over the existing method. In particular, the integrated method yields reliable ambiguity resolution and reduces position standard deviation by a factor of about 0.8, matching the theoretical gain of 3/4 for two antennas on the rotating frame and a single antenna at the reference station. PMID:25036330

  8. Integrated GNSS attitude determination and positioning for direct geo-referencing.

    PubMed

    Nadarajah, Nandakumaran; Paffenholz, Jens-André; Teunissen, Peter J G

    2014-07-17

    Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS navigation system to provide estimates of the position and attitude (orientation) of a 3D laser scanner. The proposed multi-sensor system (MSS) consists of multiple GNSS antennas rigidly mounted on the frame of a rotating laser scanner and a reference GNSS station with known coordinates. Precise GNSS navigation requires the resolution of the carrier phase ambiguities. The proposed method uses the multivariate constrained integer least-squares (MC-LAMBDA) method for the estimation of rotating frame ambiguities and attitude angles. MC-LAMBDA makes use of the known antenna geometry to strengthen the underlying attitude model and, hence, to enhance the reliability of rotating frame ambiguity resolution and attitude determination. The reliable estimation of rotating frame ambiguities is consequently utilized to enhance the relative positioning of the rotating frame with respect to the reference station. This integrated (array-aided) method improves ambiguity resolution, as well as positioning accuracy between the rotating frame and the reference station. Numerical analyses of GNSS data from a real-data campaign confirm the improved performance of the proposed method over the existing method. In particular, the integrated method yields reliable ambiguity resolution and reduces position standard deviation by a factor of about 0:8, matching the theoretical gain of √ 3/4 for two antennas on the rotating frame and a single antenna at the reference station.

  9. Comparison of direct and flow integration based charge density population analyses.

    PubMed

    Francisco, E; Martín Pendas, A; Blanco, M A; Costales, A

    2007-12-06

    Different exhaustive and fuzzy partitions of the molecular electron density (rho) into atomic densities (rho(A)) are used to compute the atomic charges (Q(A)) of a representative set of molecules. The Q(A)'s derived from a direct integration of rho(A) are compared to those obtained from integrating the deformation density rho(def) = rho - rho(0) within each atomic domain. Our analysis shows that the latter methods tend to give Q(A)'s similar to those of the (arbitrary) reference atomic densities rho(A)(0) used in the definition of the promolecular density, rho(0) = SigmaArho(A)(0). Moreover, we show that the basis set independence of these charges is a sign not of their intrinsic quality, as commonly stated, but of the practical insensitivity on the basis set of the atomic domains that are employed in this type of methods.

  10. Investigation of direct integrated optics modulators. [applicable to data preprocessors

    NASA Technical Reports Server (NTRS)

    Batchman, T. E.

    1980-01-01

    Direct modulation techniques applicable to integrated optics data preprocessors were investigated. Several methods of modulating a coherent optical beam by interaction with an incoherent beam were studied. It was decided to investigate photon induced conductivity changes in thin semiconductor cladding layers on optical waveguides. Preliminary calculations indicate significant changes can be produced in the phase shift in a propagating wave when the conductivity is changed by ten percent or more. Experimental devices to verify these predicted phase changes and experiments designed to prove the concept are described.

  11. Modern methods of experimental construction of texture complete direct pole figures by using X-ray data

    NASA Astrophysics Data System (ADS)

    Isaenkova, M.; Perlovich, Yu; Fesenko, V.

    2016-04-01

    Currently used methods for constructing texture complete direct pole figure (CDPF) based on the results of X-ray diffractometric measurements were considered with respect to the products of Zr-based alloys and, in particular, used in a nuclear reactor cladding tubes, for which the accuracy of determination of integral texture parameters is of the especial importance. The main attention was devoted to technical issues which are solved by means of computer processing of large arrays of obtained experimental data. Among considered questions there are amendments of the defocusing, techniques for constructing of complete direct pole figures and determination of integral textural parameters. The methods of reconstruction of complete direct pole figures by partial direct pole figures recorded up to tilt angles of sample ψ=70-80°: the method of extrapolation of data to an uninvestigated region of the stereographic projection, and the method of "sewing" of partial pole figures measured for three mutually perpendicular plane sections of the product. The limits of applicability of these methods, depending on the shape of the test product and the degree of inhomogeneity of the layer-by-layer texture, were revealed. On the basis of a large number of experimental data, the accuracy of the integral parameters used for calculation of the physical and mechanical properties of metals with a hexagonal crystal structure was found to be equal to 0.02, when taking into account the texture heterogeneity of regular products from Zr-based alloys.

  12. Variational methods for direct/inverse problems of atmospheric dynamics and chemistry

    NASA Astrophysics Data System (ADS)

    Penenko, Vladimir; Penenko, Alexey; Tsvetova, Elena

    2013-04-01

    We present a variational approach for solving direct and inverse problems of atmospheric hydrodynamics and chemistry. It is important that the accurate matching of numerical schemes has to be provided in the chain of objects: direct/adjoint problems - sensitivity relations - inverse problems, including assimilation of all available measurement data. To solve the problems we have developed a new enhanced set of cost-effective algorithms. The matched description of the multi-scale processes is provided by a specific choice of the variational principle functionals for the whole set of integrated models. Then all functionals of variational principle are approximated in space and time by splitting and decomposition methods. Such approach allows us to separately consider, for example, the space-time problems of atmospheric chemistry in the frames of decomposition schemes for the integral identity sum analogs of the variational principle at each time step and in each of 3D finite-volumes. To enhance the realization efficiency, the set of chemical reactions is divided on the subsets related to the operators of production and destruction. Then the idea of the Euler's integrating factors is applied in the frames of the local adjoint problem technique [1]-[3]. The analytical solutions of such adjoint problems play the role of integrating factors for differential equations describing atmospheric chemistry. With their help, the system of differential equations is transformed to the equivalent system of integral equations. As a result we avoid the construction and inversion of preconditioning operators containing the Jacobi matrixes which arise in traditional implicit schemes for ODE solution. This is the main advantage of our schemes. At the same time step but on the different stages of the "global" splitting scheme, the system of atmospheric dynamic equations is solved. For convection - diffusion equations for all state functions in the integrated models we have developed the

  13. The present state and future directions of PDF methods

    NASA Technical Reports Server (NTRS)

    Pope, S. B.

    1992-01-01

    The objectives of the workshop are presented in viewgraph format, as is this entire article. The objectives are to discuss the present status and the future direction of various levels of engineering turbulence modeling related to Computational Fluid Dynamics (CFD) computations for propulsion; to assure that combustion is an essential part of propulsion; and to discuss Probability Density Function (PDF) methods for turbulent combustion. Essential to the integration of turbulent combustion models is the development of turbulent model, chemical kinetics, and numerical method. Some turbulent combustion models typically used in industry are the k-epsilon turbulent model, the equilibrium/mixing limited combustion, and the finite volume codes.

  14. An integrated platform for directly widely-targeted quantitative analysis of feces part I: Platform configuration and method validation.

    PubMed

    Song, Yuelin; Song, Qingqing; Li, Jun; Zheng, Jiao; Li, Chun; Zhang, Yuan; Zhang, Lingling; Jiang, Yong; Tu, Pengfei

    2016-07-08

    Direct analysis is of great importance to understand the real chemical profile of a given sample, notably biological materials, because either chemical degradation or diverse errors and uncertainties might be resulted from sophisticated protocols. In comparison with biofluids, it is still challenging for direct analysis of solid biological samples using high performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Herein, a new analytical platform was configured by online hyphenating pressurized liquid extraction (PLE), turbulent flow chromatography (TFC), and LC-MS/MS. A facile, but robust PLE module was constructed based on the phenomenon that noticeable back-pressure can be generated during rapid fluid passing through a narrow tube. TFC column that is advantageous at extracting low molecular analytes from rushing fluid was employed to link at the outlet of the PLE module to capture constituents-of-interest. An electronic 6-port/2-position valve was introduced between TFC column and LC-MS/MS to fragment each measurement into extraction and elution phases, whereas LC-MS/MS took the charge of analyte separation and monitoring. As a proof of concept, simultaneous determination of 24 endogenous substances including eighteen steroids, five eicosanoids, and one porphyrin in feces was carried out in this paper. Method validation assays demonstrated the analytical platform to be qualified for directly simultaneous measurement of diverse endogenous analytes in fecal matrices. Application of this integrated platform on homolog-focused profiling of feces is discussed in a companion paper. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Development of Improved Surface Integral Methods for Jet Aeroacoustic Predictions

    NASA Technical Reports Server (NTRS)

    Pilon, Anthony R.; Lyrintzis, Anastasios S.

    1997-01-01

    The accurate prediction of aerodynamically generated noise has become an important goal over the past decade. Aeroacoustics must now be an integral part of the aircraft design process. The direct calculation of aerodynamically generated noise with CFD-like algorithms is plausible. However, large computer time and memory requirements often make these predictions impractical. It is therefore necessary to separate the aeroacoustics problem into two parts, one in which aerodynamic sound sources are determined, and another in which the propagating sound is calculated. This idea is applied in acoustic analogy methods. However, in the acoustic analogy, the determination of far-field sound requires the solution of a volume integral. This volume integration again leads to impractical computer requirements. An alternative to the volume integrations can be found in the Kirchhoff method. In this method, Green's theorem for the linear wave equation is used to determine sound propagation based on quantities on a surface surrounding the source region. The change from volume to surface integrals represents a tremendous savings in the computer resources required for an accurate prediction. This work is concerned with the development of enhancements of the Kirchhoff method for use in a wide variety of aeroacoustics problems. This enhanced method, the modified Kirchhoff method, is shown to be a Green's function solution of Lighthill's equation. It is also shown rigorously to be identical to the methods of Ffowcs Williams and Hawkings. This allows for development of versatile computer codes which can easily alternate between the different Kirchhoff and Ffowcs Williams-Hawkings formulations, using the most appropriate method for the problem at hand. The modified Kirchhoff method is developed primarily for use in jet aeroacoustics predictions. Applications of the method are shown for two dimensional and three dimensional jet flows. Additionally, the enhancements are generalized so that

  16. Integrated Force Method for Indeterminate Structures

    NASA Technical Reports Server (NTRS)

    Hopkins, Dale A.; Halford, Gary R.; Patnaik, Surya N.

    2008-01-01

    Two methods of solving indeterminate structural-mechanics problems have been developed as products of research on the theory of strain compatibility. In these methods, stresses are considered to be the primary unknowns (in contrast to strains and displacements being considered as the primary unknowns in some prior methods). One of these methods, denoted the integrated force method (IFM), makes it possible to compute stresses, strains, and displacements with high fidelity by use of modest finite-element models that entail relatively small amounts of computation. The other method, denoted the completed Beltrami Mitchell formulation (CBMF), enables direct determination of stresses in an elastic continuum with general boundary conditions, without the need to first calculate displacements as in traditional methods. The equilibrium equation, the compatibility condition, and the material law are the three fundamental concepts of the theory of structures. For almost 150 years, it has been commonly supposed that the theory is complete. However, until now, the understanding of the compatibility condition remained incomplete, and the compatibility condition was confused with the continuity condition. Furthermore, the compatibility condition as applied to structures in its previous incomplete form was inconsistent with the strain formulation in elasticity.

  17. Integrated modeling and analysis of the multiple electromechanical couplings for the direct driven feed system in machine tools

    NASA Astrophysics Data System (ADS)

    Yang, Xiaojun; Lu, Dun; Liu, Hui; Zhao, Wanhua

    2018-06-01

    The complicated electromechanical coupling phenomena due to different kinds of causes have significant influences on the dynamic precision of the direct driven feed system in machine tools. In this paper, a novel integrated modeling and analysis method of the multiple electromechanical couplings for the direct driven feed system in machine tools is presented. At first, four different kinds of electromechanical coupling phenomena in the direct driven feed system are analyzed systematically. Then a novel integrated modeling and analysis method of the electromechanical coupling which is influenced by multiple factors is put forward. In addition, the effects of multiple electromechanical couplings on the dynamic precision of the feed system and their main influencing factors are compared and discussed, respectively. Finally, the results of modeling and analysis are verified by the experiments. It finds out that multiple electromechanical coupling loops, which are overlapped and influenced by each other, are the main reasons of the displacement fluctuations in the direct driven feed system.

  18. Ion-beam apparatus and method for analyzing and controlling integrated circuits

    DOEpatents

    Campbell, A.N.; Soden, J.M.

    1998-12-01

    An ion-beam apparatus and method for analyzing and controlling integrated circuits are disclosed. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal. 4 figs.

  19. Ion-beam apparatus and method for analyzing and controlling integrated circuits

    DOEpatents

    Campbell, Ann N.; Soden, Jerry M.

    1998-01-01

    An ion-beam apparatus and method for analyzing and controlling integrated circuits. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal.

  20. Fast integral methods for integrated optical systems simulations: a review

    NASA Astrophysics Data System (ADS)

    Kleemann, Bernd H.

    2015-09-01

    Boundary integral equation methods (BIM) or simply integral methods (IM) in the context of optical design and simulation are rigorous electromagnetic methods solving Helmholtz or Maxwell equations on the boundary (surface or interface of the structures between two materials) for scattering or/and diffraction purposes. This work is mainly restricted to integral methods for diffracting structures such as gratings, kinoforms, diffractive optical elements (DOEs), micro Fresnel lenses, computer generated holograms (CGHs), holographic or digital phase holograms, periodic lithographic structures, and the like. In most cases all of the mentioned structures have dimensions of thousands of wavelengths in diameter. Therefore, the basic methods necessary for the numerical treatment are locally applied electromagnetic grating diffraction algorithms. Interestingly, integral methods belong to the first electromagnetic methods investigated for grating diffraction. The development started in the mid 1960ies for gratings with infinite conductivity and it was mainly due to the good convergence of the integral methods especially for TM polarization. The first integral equation methods (IEM) for finite conductivity were the methods by D. Maystre at Fresnel Institute in Marseille: in 1972/74 for dielectric, and metallic gratings, and later for multiprofile, and other types of gratings and for photonic crystals. Other methods such as differential and modal methods suffered from unstable behaviour and slow convergence compared to BIMs for metallic gratings in TM polarization from the beginning to the mid 1990ies. The first BIM for gratings using a parametrization of the profile was developed at Karl-Weierstrass Institute in Berlin under a contract with Carl Zeiss Jena works in 1984-1986 by A. Pomp, J. Creutziger, and the author. Due to the parametrization, this method was able to deal with any kind of surface grating from the beginning: whether profiles with edges, overhanging non

  1. The Practice Integration Profile: Rationale, development, method, and research.

    PubMed

    Macchi, C R; Kessler, Rodger; Auxier, Andrea; Hitt, Juvena R; Mullin, Daniel; van Eeghen, Constance; Littenberg, Benjamin

    2016-12-01

    Insufficient knowledge exists regarding how to measure the presence and degree of integrated care. Prior estimates of integration levels are neither grounded in theory nor psychometrically validated. They provide scant guidance to inform improvement activities, compare integration efforts, discriminate among practices by degree of integration, measure the effect of integration on quadruple aim outcomes, or address the needs of clinicians, regulators, and policymakers seeking new models of health care delivery and funding. We describe the development of the Practice Integration Profile (PIP), a novel instrument designed to measure levels of integrated behavioral health care within a primary care clinic. The PIP draws upon the Agency for Health care Research & Quality's (AHRQ) Lexicon of Collaborative Care which provides theoretic justification for a paradigm case of collaborative care. We used the key clauses of the Lexicon to derive domains of integration and generate measures corresponding to those key clauses. After reviewing currently used methods for identifying collaborative care, or integration, and identifying the need to improve on them, we describe a national collaboration to describe and evaluate the PIP. We also describe its potential use in practice improvement, research, responsiveness to multiple stakeholder needs, and other future directions. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. Cross-guide Moreno directional coupler in empty substrate integrated waveguide

    NASA Astrophysics Data System (ADS)

    Miralles, E.; Belenguer, A.; Esteban, H.; Boria, V.

    2017-05-01

    Substrate integrated waveguides (SIWs) combine the advantages of rectangular waveguides (low losses) and planar circuits (low cost and low profile). Empty substrate integrated waveguide (ESIW) has been proposed as a novel configuration in SIWs recently. This technology significantly reduces the losses of conventional SIW by removing its inner dielectric. The cross-guide directional coupler is a well-known low-profile design for having a broadband waveguide coupler. In this paper a cross-guide coupler with ESIW technique is proposed. In such a manner, the device can be integrated with microwave circuits and other printed circuit board components. It is the first time that a cross-guide coupler is implemented in ESIW technology. The designed, fabricated, and measured device presents good results as a matter of insertion loss of 1 dB (including transitions), reflection under 20 dB, coupling between 19.5 and 21.5 dB, and directivity higher than 15 dB over targeted frequency range from 12.4 GHz to 18 GHz. The coupler implemented in ESIW improves the directivity when compared to similar solutions in other empty substrate integrated waveguide solutions.

  3. Direct integration of polycrystalline graphene into light emitting diodes by plasma-assisted metal-catalyst-free synthesis.

    PubMed

    Kim, Yong Seung; Joo, Kisu; Jerng, Sahng-Kyoon; Lee, Jae Hong; Moon, Daeyoung; Kim, Jonghak; Yoon, Euijoon; Chun, Seung-Hyun

    2014-03-25

    The integration of graphene into devices is a challenging task because the preparation of a graphene-based device usually includes graphene growth on a metal surface at elevated temperatures (∼1000 °C) and a complicated postgrowth transfer process of graphene from the metal catalyst. Here we report a direct integration approach for incorporating polycrystalline graphene into light emitting diodes (LEDs) at low temperature by plasma-assisted metal-catalyst-free synthesis. Thermal degradation of the active layer in LEDs is negligible at our growth temperature, and LEDs could be fabricated without a transfer process. Moreover, in situ ohmic contact formation is observed between DG and p-GaN resulting from carbon diffusion into the p-GaN surface during the growth process. As a result, the contact resistance is reduced and the electrical properties of directly integrated LEDs outperform those of LEDs with transferred graphene electrodes. This relatively simple method of graphene integration will be easily adoptable in the industrialization of graphene-based devices.

  4. Methods and systems for integrating fluid dispensing technology with stereolithography

    DOEpatents

    Medina, Francisco; Wicker, Ryan; Palmer, Jeremy A.; Davis, Don W.; Chavez, Bart D.; Gallegos, Phillip L.

    2010-02-09

    An integrated system and method of integrating fluid dispensing technologies (e.g., direct-write (DW)) with rapid prototyping (RP) technologies (e.g., stereolithography (SL)) without part registration comprising: an SL apparatus and a fluid dispensing apparatus further comprising a translation mechanism adapted to translate the fluid dispensing apparatus along the Z-, Y- and Z-axes. The fluid dispensing apparatus comprises: a pressurized fluid container; a valve mechanism adapted to control the flow of fluid from the pressurized fluid container; and a dispensing nozzle adapted to deposit the fluid in a desired location. To aid in calibration, the integrated system includes a laser sensor and a mechanical switch. The method further comprises building a second part layer on top of the fluid deposits and optionally accommodating multi-layered circuitry by incorporating a connector trace. Thus, the present invention is capable of efficiently building single and multi-material SL fabricated parts embedded with complex three-dimensional circuitry using DW.

  5. Three-dimensional application of the Johnson-King turbulence model for a boundary-layer direct method

    NASA Technical Reports Server (NTRS)

    Kavsaoglu, Mehmet S.; Kaynak, Unver; Van Dalsem, William R.

    1989-01-01

    The Johnson-King turbulence model as extended to three-dimensional flows was evaluated using finite-difference boundary-layer direct method. Calculations were compared against the experimental data of the well-known Berg-Elsenaar incompressible flow over an infinite swept-wing. The Johnson-King model, which includes the nonequilibrium effects in a developing turbulent boundary-layer, was found to significantly improve the predictive quality of a direct boundary-layer method. The improvement was especially visible in the computations with increased three-dimensionality of the mean flow, larger integral parameters, and decreasing eddy-viscosity and shear stress magnitudes in the streamwise direction; all in better agreement with the experiment than simple mixing-length methods.

  6. A novel method for sampling the suspended sediment load in the tidal environment using bi-directional time-integrated mass-flux sediment (TIMS) samplers

    NASA Astrophysics Data System (ADS)

    Elliott, Emily A.; Monbureau, Elaine; Walters, Glenn W.; Elliott, Mark A.; McKee, Brent A.; Rodriguez, Antonio B.

    2017-12-01

    Identifying the source and abundance of sediment transported within tidal creeks is essential for studying the connectivity between coastal watersheds and estuaries. The fine-grained suspended sediment load (SSL) makes up a substantial portion of the total sediment load carried within an estuarine system and efficient sampling of the SSL is critical to our understanding of nutrient and contaminant transport, anthropogenic influence, and the effects of climate. Unfortunately, traditional methods of sampling the SSL, including instantaneous measurements and automatic samplers, can be labor intensive, expensive and often yield insufficient mass for comprehensive geochemical analysis. In estuaries this issue is even more pronounced due to bi-directional tidal flow. This study tests the efficacy of a time-integrated mass sediment sampler (TIMS) design, originally developed for uni-directional flow within the fluvial environment, modified in this work for implementation the tidal environment under bi-directional flow conditions. Our new TIMS design utilizes an 'L' shaped outflow tube to prevent backflow, and when deployed in mirrored pairs, each sampler collects sediment uniquely in one direction of tidal flow. Laboratory flume experiments using dye and particle image velocimetry (PIV) were used to characterize the flow within the sampler, specifically, to quantify the settling velocities and identify stagnation points. Further laboratory tests of sediment indicate that bidirectional TIMS capture up to 96% of incoming SSL across a range of flow velocities (0.3-0.6 m s-1). The modified TIMS design was tested in the field at two distinct sampling locations within the tidal zone. Single-time point suspended sediment samples were collected at high and low tide and compared to time-integrated suspended sediment samples collected by the bi-directional TIMS over the same four-day period. Particle-size composition from the bi-directional TIMS were representative of the array of

  7. On the Formulation of Weakly Singular Displacement/Traction Integral Equations; and Their Solution by the MLPG Method

    NASA Technical Reports Server (NTRS)

    Atluri, Satya N.; Shen, Shengping

    2002-01-01

    In this paper, a very simple method is used to derive the weakly singular traction boundary integral equation based on the integral relationships for displacement gradients. The concept of the MLPG method is employed to solve the integral equations, especially those arising in solid mechanics. A moving Least Squares (MLS) interpolation is selected to approximate the trial functions in this paper. Five boundary integral Solution methods are introduced: direct solution method; displacement boundary-value problem; traction boundary-value problem; mixed boundary-value problem; and boundary variational principle. Based on the local weak form of the BIE, four different nodal-based local test functions are selected, leading to four different MLPG methods for each BIE solution method. These methods combine the advantages of the MLPG method and the boundary element method.

  8. A wideband FMBEM for 2D acoustic design sensitivity analysis based on direct differentiation method

    NASA Astrophysics Data System (ADS)

    Chen, Leilei; Zheng, Changjun; Chen, Haibo

    2013-09-01

    This paper presents a wideband fast multipole boundary element method (FMBEM) for two dimensional acoustic design sensitivity analysis based on the direct differentiation method. The wideband fast multipole method (FMM) formed by combining the original FMM and the diagonal form FMM is used to accelerate the matrix-vector products in the boundary element analysis. The Burton-Miller formulation is used to overcome the fictitious frequency problem when using a single Helmholtz boundary integral equation for exterior boundary-value problems. The strongly singular and hypersingular integrals in the sensitivity equations can be evaluated explicitly and directly by using the piecewise constant discretization. The iterative solver GMRES is applied to accelerate the solution of the linear system of equations. A set of optimal parameters for the wideband FMBEM design sensitivity analysis are obtained by observing the performances of the wideband FMM algorithm in terms of computing time and memory usage. Numerical examples are presented to demonstrate the efficiency and validity of the proposed algorithm.

  9. Relationships in consumer-directed care: An integrative literature review.

    PubMed

    Cash, Tracee; Moyle, Wendy; O'Dwyer, Siobhan

    2017-09-01

    To undertake an integrative review of the literature on relationships between community aged care recipients, family carers and care providers under consumer-directed care (CDC). Seven databases were systematically searched. Peer-reviewed and grey literature on CDC between 1998 and 2014 were assessed using an integrative literature review (ILR) framework. Search terms included CDC, self-directed care, direct payments, community aged care, community dwelling and older adults. Full-text copies were assessed against the inclusion criteria. Fifteen studies met the inclusion criteria. This ILR found no research with a specific focus on caregiving relationships for older adults. The literature did however identify relational issues such as support, planning and provider attitude as fundamental to the success of CDC. Relationships within the caregiving triad have important implications for the way CDC is enacted, particularly when the care recipient has dementia, suggesting this population as a priority for future research. © 2017 AJA Inc.

  10. Robust rotational-velocity-Verlet integration methods.

    PubMed

    Rozmanov, Dmitri; Kusalik, Peter G

    2010-05-01

    Two rotational integration algorithms for rigid-body dynamics are proposed in velocity-Verlet formulation. The first method uses quaternion dynamics and was derived from the original rotational leap-frog method by Svanberg [Mol. Phys. 92, 1085 (1997)]; it produces time consistent positions and momenta. The second method is also formulated in terms of quaternions but it is not quaternion specific and can be easily adapted for any other orientational representation. Both the methods are tested extensively and compared to existing rotational integrators. The proposed integrators demonstrated performance at least at the level of previously reported rotational algorithms. The choice of simulation parameters is also discussed.

  11. Robust rotational-velocity-Verlet integration methods

    NASA Astrophysics Data System (ADS)

    Rozmanov, Dmitri; Kusalik, Peter G.

    2010-05-01

    Two rotational integration algorithms for rigid-body dynamics are proposed in velocity-Verlet formulation. The first method uses quaternion dynamics and was derived from the original rotational leap-frog method by Svanberg [Mol. Phys. 92, 1085 (1997)]; it produces time consistent positions and momenta. The second method is also formulated in terms of quaternions but it is not quaternion specific and can be easily adapted for any other orientational representation. Both the methods are tested extensively and compared to existing rotational integrators. The proposed integrators demonstrated performance at least at the level of previously reported rotational algorithms. The choice of simulation parameters is also discussed.

  12. [Evaluating the Significance of Odor Gas Released During the Directly Drying Process of Sludge: Based on the Multi-index Integrated Assessment Method].

    PubMed

    Ding, Wen-jie; Chen, Wen-he; Deng, Ming-jia; Luo, Hui; Li, Lin; Liu, Jun-xin

    2016-02-15

    Co-processing of sewage sludge using the cement kiln can realize sludge harmless treatment, quantity reduction, stabilization and reutilization. The moisture content should be reduced to below 30% to meet the requirement of combustion. Thermal drying is an effective way for sludge desiccation. Odors and volatile organic compounds are generated and released during the sludge drying process, which could lead to odor pollution. The main odor pollutants were selected by the multi-index integrated assessment method. The concentration, olfactory threshold, threshold limit value, smell security level and saturated vapor pressure were considered as indexes based on the related regulations in China and foreign countries. Taking the pollution potential as the evaluation target, and the risk index and odor emission intensity as evaluation indexes, the odor pollution potential rated evaluation model of the pollutants was built according to the Weber-Fechner law. The aim of the present study is to form the rating evaluation method of odor potential pollution capacity suitable for the directly drying process of sludge.

  13. Novel Random Mutagenesis Method for Directed Evolution.

    PubMed

    Feng, Hong; Wang, Hai-Yan; Zhao, Hong-Yan

    2017-01-01

    Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

  14. Servo-integrated patterned media by hybrid directed self-assembly.

    PubMed

    Xiao, Shuaigang; Yang, Xiaomin; Steiner, Philip; Hsu, Yautzong; Lee, Kim; Wago, Koichi; Kuo, David

    2014-11-25

    A hybrid directed self-assembly approach is developed to fabricate unprecedented servo-integrated bit-patterned media templates, by combining sphere-forming block copolymers with 5 teradot/in.(2) resolution capability, nanoimprint and optical lithography with overlay control. Nanoimprint generates prepatterns with different dimensions in the data field and servo field, respectively, and optical lithography controls the selective self-assembly process in either field. Two distinct directed self-assembly techniques, low-topography graphoepitaxy and high-topography graphoepitaxy, are elegantly integrated to create bit-patterned templates with flexible embedded servo information. Spinstand magnetic test at 1 teradot/in.(2) shows a low bit error rate of 10(-2.43), indicating fully functioning bit-patterned media and great potential of this approach for fabricating future ultra-high-density magnetic storage media.

  15. The staircase method: integrals for periodic reductions of integrable lattice equations

    NASA Astrophysics Data System (ADS)

    van der Kamp, Peter H.; Quispel, G. R. W.

    2010-11-01

    We show, in full generality, that the staircase method (Papageorgiou et al 1990 Phys. Lett. A 147 106-14, Quispel et al 1991 Physica A 173 243-66) provides integrals for mappings, and correspondences, obtained as traveling wave reductions of (systems of) integrable partial difference equations. We apply the staircase method to a variety of equations, including the Korteweg-De Vries equation, the five-point Bruschi-Calogero-Droghei equation, the quotient-difference (QD)-algorithm and the Boussinesq system. We show that, in all these cases, if the staircase method provides r integrals for an n-dimensional mapping, with 2r, then one can introduce q <= 2r variables, which reduce the dimension of the mapping from n to q. These dimension-reducing variables are obtained as joint invariants of k-symmetries of the mappings. Our results support the idea that often the staircase method provides sufficiently many integrals for the periodic reductions of integrable lattice equations to be completely integrable. We also study reductions on other quad-graphs than the regular {\\ Z}^2 lattice, and we prove linear growth of the multi-valuedness of iterates of high-dimensional correspondences obtained as reductions of the QD-algorithm.

  16. The integral line-beam method for gamma skyshine analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shultis, J.K.; Faw, R.E.; Bassett, M.S.

    1991-03-01

    This paper presents a refinement of a simplified method, based on line-beam response functions, for performing skyshine calculations for shielded and collimated gamma-ray sources. New coefficients for an empirical fit to the line-beam response function are provided and a prescription for making the response function continuous in energy and emission direction is introduced. For a shielded source, exponential attenuation and a buildup factor correction for scattered photons in the shield are used. Results of the new integral line-beam method of calculation are compared to a variety of benchmark experimental data and calculations and are found to give generally excellent agreementmore » at a small fraction of the computational expense required by other skyshine methods.« less

  17. Scenario driven data modelling: a method for integrating diverse sources of data and data streams

    DOEpatents

    Brettin, Thomas S.; Cottingham, Robert W.; Griffith, Shelton D.; Quest, Daniel J.

    2015-09-08

    A system and method of integrating diverse sources of data and data streams is presented. The method can include selecting a scenario based on a topic, creating a multi-relational directed graph based on the scenario, identifying and converting resources in accordance with the scenario and updating the multi-directed graph based on the resources, identifying data feeds in accordance with the scenario and updating the multi-directed graph based on the data feeds, identifying analytical routines in accordance with the scenario and updating the multi-directed graph using the analytical routines and identifying data outputs in accordance with the scenario and defining queries to produce the data outputs from the multi-directed graph.

  18. Integrated direct/indirect adaptive robust motion trajectory tracking control of pneumatic cylinders

    NASA Astrophysics Data System (ADS)

    Meng, Deyuan; Tao, Guoliang; Zhu, Xiaocong

    2013-09-01

    This paper studies the precision motion trajectory tracking control of a pneumatic cylinder driven by a proportional-directional control valve. An integrated direct/indirect adaptive robust controller is proposed. The controller employs a physical model based indirect-type parameter estimation to obtain reliable estimates of unknown model parameters, and utilises a robust control method with dynamic compensation type fast adaptation to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. Due to the use of projection mapping, the robust control law and the parameter adaption algorithm can be designed separately. Since the system model uncertainties are unmatched, the recursive backstepping technology is adopted to design the robust control law. Extensive comparative experimental results are presented to illustrate the effectiveness of the proposed controller and its performance robustness to parameter variations and sudden disturbances.

  19. Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

    NASA Astrophysics Data System (ADS)

    Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

    2015-07-01

    We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits.

  20. Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide.

    PubMed

    Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Kim, Un Jeong; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

    2015-07-02

    We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a "plasmonic via" in plasmonic nanocircuits.

  1. Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

    PubMed Central

    Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

    2015-01-01

    We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits. PMID:26135115

  2. Evaluation of radiation loading on finite cylindrical shells using the fast Fourier transform: A comparison with direct numerical integration.

    PubMed

    Liu, S X; Zou, M S

    2018-03-01

    The radiation loading on a vibratory finite cylindrical shell is conventionally evaluated through the direct numerical integration (DNI) method. An alternative strategy via the fast Fourier transform algorithm is put forward in this work based on the general expression of radiation impedance. To check the feasibility and efficiency of the proposed method, a comparison with DNI is presented through numerical cases. The results obtained using the present method agree well with those calculated by DNI. More importantly, the proposed calculating strategy can significantly save the time cost compared with the conventional approach of straightforward numerical integration.

  3. Direct power control of DFIG wind turbine systems based on an intelligent proportional-integral sliding mode control.

    PubMed

    Li, Shanzhi; Wang, Haoping; Tian, Yang; Aitouch, Abdel; Klein, John

    2016-09-01

    This paper presents an intelligent proportional-integral sliding mode control (iPISMC) for direct power control of variable speed-constant frequency wind turbine system. This approach deals with optimal power production (in the maximum power point tracking sense) under several disturbance factors such as turbulent wind. This controller is made of two sub-components: (i) an intelligent proportional-integral module for online disturbance compensation and (ii) a sliding mode module for circumventing disturbance estimation errors. This iPISMC method has been tested on FAST/Simulink platform of a 5MW wind turbine system. The obtained results demonstrate that the proposed iPISMC method outperforms the classical PI and intelligent proportional-integral control (iPI) in terms of both active power and response time. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  4. GRAVIDY, a GPU modular, parallel direct-summation N-body integrator: dynamics with softening

    NASA Astrophysics Data System (ADS)

    Maureira-Fredes, Cristián; Amaro-Seoane, Pau

    2018-01-01

    A wide variety of outstanding problems in astrophysics involve the motion of a large number of particles under the force of gravity. These include the global evolution of globular clusters, tidal disruptions of stars by a massive black hole, the formation of protoplanets and sources of gravitational radiation. The direct-summation of N gravitational forces is a complex problem with no analytical solution and can only be tackled with approximations and numerical methods. To this end, the Hermite scheme is a widely used integration method. With different numerical techniques and special-purpose hardware, it can be used to speed up the calculations. But these methods tend to be computationally slow and cumbersome to work with. We present a new graphics processing unit (GPU), direct-summation N-body integrator written from scratch and based on this scheme, which includes relativistic corrections for sources of gravitational radiation. GRAVIDY has high modularity, allowing users to readily introduce new physics, it exploits available computational resources and will be maintained by regular updates. GRAVIDY can be used in parallel on multiple CPUs and GPUs, with a considerable speed-up benefit. The single-GPU version is between one and two orders of magnitude faster than the single-CPU version. A test run using four GPUs in parallel shows a speed-up factor of about 3 as compared to the single-GPU version. The conception and design of this first release is aimed at users with access to traditional parallel CPU clusters or computational nodes with one or a few GPU cards.

  5. Self-organizing path integration using a linked continuous attractor and competitive network: path integration of head direction.

    PubMed

    Stringer, Simon M; Rolls, Edmund T

    2006-12-01

    A key issue is how networks in the brain learn to perform path integration, that is update a represented position using a velocity signal. Using head direction cells as an example, we show that a competitive network could self-organize to learn to respond to combinations of head direction and angular head rotation velocity. These combination cells can then be used to drive a continuous attractor network to the next head direction based on the incoming rotation signal. An associative synaptic modification rule with a short term memory trace enables preceding combination cell activity during training to be associated with the next position in the continuous attractor network. The network accounts for the presence of neurons found in the brain that respond to combinations of head direction and angular head rotation velocity. Analogous networks in the hippocampal system could self-organize to perform path integration of place and spatial view representations.

  6. Direct ultrafiltration performance and membrane integrity monitoring by microbiological analysis.

    PubMed

    Ferrer, O; Casas, S; Galvañ, C; Lucena, F; Bosch, A; Galofré, B; Mesa, J; Jofre, J; Bernat, X

    2015-10-15

    The feasibility of substituting a conventional pre-treatment, consisting of dioxi-chlorination, coagulation/flocculation, settling and sand filtration, of a drinking water treatment plant (DWTP) by direct ultrafiltration (UF) has been assessed from a microbiological standpoint. Bacterial indicators, viral indicators and human viruses have been monitored in raw river, ultrafiltered and conventionally pre-treated water samples during two years. Direct UF has proven to remove bacterial indicators quite efficiently and to a greater extent than the conventional process does. Nevertheless, the removal of small viruses such as some small bacteriophages and human viruses (e.g. enteroviruses and noroviruses) is lower than the current conventional pre-treatment. Membrane integrity has been assessed during two years by means of tailored tests based on bacteriophages with different properties (MS-2, GA and PDR-1) and bacterial spores (Bacillus spores). Membrane integrity has not been compromised despite the challenging conditions faced by directly treating raw river water. Bacteriophage PDR-1 appears as a suitable microbe to test membrane integrity, as its size is slightly larger than the considered membrane pore size. However, its implementation at full scale plant is still challenging due to difficulties in obtaining enough phages for its seeding. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Direct Instruction vs. Arts Integration: A False Dichotomy

    ERIC Educational Resources Information Center

    Aprill, Arnold

    2010-01-01

    In this article, the author takes on what he considers to be the false dichotomy between direct instruction and arts integration. He contends that at a time when national issues of sustainability and conservation of energy and resources become ever more urgent, it is time that those committed to quality arts education stop squandering time, money,…

  8. The preparation method of terahertz monolithic integrated device

    NASA Astrophysics Data System (ADS)

    Zhang, Cong; Su, Bo; He, Jingsuo; Zhang, Hongfei; Wu, Yaxiong; Zhang, Shengbo; Zhang, Cunlin

    2018-01-01

    The terahertz monolithic integrated device is to integrate the pumping area of the terahertz generation, the detection area of the terahertz receiving and the metal waveguide of terahertz transmission on the same substrate. The terahertz generation and detection device use a photoconductive antenna structure the metal waveguide use a microstrip line structure. The evanescent terahertz-bandwidth electric field extending above the terahertz transmission line interacts with, and is modified by, overlaid dielectric samples, thus enabling the characteristic vibrational absorption resonances in the sample to be probed. In this device structure, since the semiconductor substrate of the photoconductive antenna is located between the strip conductor and the dielectric layer of the microstrip line, and the semiconductor substrate cannot grow on the dielectric layer directly. So how to prepare the semiconductor substrate of the photoconductive antenna and how to bond the semiconductor substrate to the dielectric layer of the microstrip line is a key step in the terahertz monolithic integrated device. In order to solve this critical problem, the epitaxial wafer structure of the two semiconductor substrates is given and transferred to the desired substrate by two methods, respectively.

  9. AI/OR computational model for integrating qualitative and quantitative design methods

    NASA Technical Reports Server (NTRS)

    Agogino, Alice M.; Bradley, Stephen R.; Cagan, Jonathan; Jain, Pramod; Michelena, Nestor

    1990-01-01

    A theoretical framework for integrating qualitative and numerical computational methods for optimally-directed design is described. The theory is presented as a computational model and features of implementations are summarized where appropriate. To demonstrate the versatility of the methodology we focus on four seemingly disparate aspects of the design process and their interaction: (1) conceptual design, (2) qualitative optimal design, (3) design innovation, and (4) numerical global optimization.

  10. Numerical methods for engine-airframe integration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Murthy, S.N.B.; Paynter, G.C.

    1986-01-01

    Various papers on numerical methods for engine-airframe integration are presented. The individual topics considered include: scientific computing environment for the 1980s, overview of prediction of complex turbulent flows, numerical solutions of the compressible Navier-Stokes equations, elements of computational engine/airframe integrations, computational requirements for efficient engine installation, application of CAE and CFD techniques to complete tactical missile design, CFD applications to engine/airframe integration, and application of a second-generation low-order panel methods to powerplant installation studies. Also addressed are: three-dimensional flow analysis of turboprop inlet and nacelle configurations, application of computational methods to the design of large turbofan engine nacelles, comparison ofmore » full potential and Euler solution algorithms for aeropropulsive flow field computations, subsonic/transonic, supersonic nozzle flows and nozzle integration, subsonic/transonic prediction capabilities for nozzle/afterbody configurations, three-dimensional viscous design methodology of supersonic inlet systems for advanced technology aircraft, and a user's technology assessment.« less

  11. Mechanical System Reliability and Cost Integration Using a Sequential Linear Approximation Method

    NASA Technical Reports Server (NTRS)

    Kowal, Michael T.

    1997-01-01

    The development of new products is dependent on product designs that incorporate high levels of reliability along with a design that meets predetermined levels of system cost. Additional constraints on the product include explicit and implicit performance requirements. Existing reliability and cost prediction methods result in no direct linkage between variables affecting these two dominant product attributes. A methodology to integrate reliability and cost estimates using a sequential linear approximation method is proposed. The sequential linear approximation method utilizes probability of failure sensitivities determined from probabilistic reliability methods as well a manufacturing cost sensitivities. The application of the sequential linear approximation method to a mechanical system is demonstrated.

  12. Review of Statistical Learning Methods in Integrated Omics Studies (An Integrated Information Science).

    PubMed

    Zeng, Irene Sui Lan; Lumley, Thomas

    2018-01-01

    Integrated omics is becoming a new channel for investigating the complex molecular system in modern biological science and sets a foundation for systematic learning for precision medicine. The statistical/machine learning methods that have emerged in the past decade for integrated omics are not only innovative but also multidisciplinary with integrated knowledge in biology, medicine, statistics, machine learning, and artificial intelligence. Here, we review the nontrivial classes of learning methods from the statistical aspects and streamline these learning methods within the statistical learning framework. The intriguing findings from the review are that the methods used are generalizable to other disciplines with complex systematic structure, and the integrated omics is part of an integrated information science which has collated and integrated different types of information for inferences and decision making. We review the statistical learning methods of exploratory and supervised learning from 42 publications. We also discuss the strengths and limitations of the extended principal component analysis, cluster analysis, network analysis, and regression methods. Statistical techniques such as penalization for sparsity induction when there are fewer observations than the number of features and using Bayesian approach when there are prior knowledge to be integrated are also included in the commentary. For the completeness of the review, a table of currently available software and packages from 23 publications for omics are summarized in the appendix.

  13. Parallel/Vector Integration Methods for Dynamical Astronomy

    NASA Astrophysics Data System (ADS)

    Fukushima, Toshio

    1999-01-01

    This paper reviews three recent works on the numerical methods to integrate ordinary differential equations (ODE), which are specially designed for parallel, vector, and/or multi-processor-unit(PU) computers. The first is the Picard-Chebyshev method (Fukushima, 1997a). It obtains a global solution of ODE in the form of Chebyshev polynomial of large (> 1000) degree by applying the Picard iteration repeatedly. The iteration converges for smooth problems and/or perturbed dynamics. The method runs around 100-1000 times faster in the vector mode than in the scalar mode of a certain computer with vector processors (Fukushima, 1997b). The second is a parallelization of a symplectic integrator (Saha et al., 1997). It regards the implicit midpoint rules covering thousands of timesteps as large-scale nonlinear equations and solves them by the fixed-point iteration. The method is applicable to Hamiltonian systems and is expected to lead an acceleration factor of around 50 in parallel computers with more than 1000 PUs. The last is a parallelization of the extrapolation method (Ito and Fukushima, 1997). It performs trial integrations in parallel. Also the trial integrations are further accelerated by balancing computational load among PUs by the technique of folding. The method is all-purpose and achieves an acceleration factor of around 3.5 by using several PUs. Finally, we give a perspective on the parallelization of some implicit integrators which require multiple corrections in solving implicit formulas like the implicit Hermitian integrators (Makino and Aarseth, 1992), (Hut et al., 1995) or the implicit symmetric multistep methods (Fukushima, 1998), (Fukushima, 1999).

  14. Implicit integration methods for dislocation dynamics

    DOE PAGES

    Gardner, D. J.; Woodward, C. S.; Reynolds, D. R.; ...

    2015-01-20

    In dislocation dynamics simulations, strain hardening simulations require integrating stiff systems of ordinary differential equations in time with expensive force calculations, discontinuous topological events, and rapidly changing problem size. Current solvers in use often result in small time steps and long simulation times. Faster solvers may help dislocation dynamics simulations accumulate plastic strains at strain rates comparable to experimental observations. Here, this paper investigates the viability of high order implicit time integrators and robust nonlinear solvers to reduce simulation run times while maintaining the accuracy of the computed solution. In particular, implicit Runge-Kutta time integrators are explored as a waymore » of providing greater accuracy over a larger time step than is typically done with the standard second-order trapezoidal method. In addition, both accelerated fixed point and Newton's method are investigated to provide fast and effective solves for the nonlinear systems that must be resolved within each time step. Results show that integrators of third order are the most effective, while accelerated fixed point and Newton's method both improve solver performance over the standard fixed point method used for the solution of the nonlinear systems.« less

  15. Efficient integration method for fictitious domain approaches

    NASA Astrophysics Data System (ADS)

    Duczek, Sascha; Gabbert, Ulrich

    2015-10-01

    In the current article, we present an efficient and accurate numerical method for the integration of the system matrices in fictitious domain approaches such as the finite cell method (FCM). In the framework of the FCM, the physical domain is embedded in a geometrically larger domain of simple shape which is discretized using a regular Cartesian grid of cells. Therefore, a spacetree-based adaptive quadrature technique is normally deployed to resolve the geometry of the structure. Depending on the complexity of the structure under investigation this method accounts for most of the computational effort. To reduce the computational costs for computing the system matrices an efficient quadrature scheme based on the divergence theorem (Gauß-Ostrogradsky theorem) is proposed. Using this theorem the dimension of the integral is reduced by one, i.e. instead of solving the integral for the whole domain only its contour needs to be considered. In the current paper, we present the general principles of the integration method and its implementation. The results to several two-dimensional benchmark problems highlight its properties. The efficiency of the proposed method is compared to conventional spacetree-based integration techniques.

  16. Mining method selection by integrated AHP and PROMETHEE method.

    PubMed

    Bogdanovic, Dejan; Nikolic, Djordje; Ilic, Ivana

    2012-03-01

    Selecting the best mining method among many alternatives is a multicriteria decision making problem. The aim of this paper is to demonstrate the implementation of an integrated approach that employs AHP and PROMETHEE together for selecting the most suitable mining method for the "Coka Marin" underground mine in Serbia. The related problem includes five possible mining methods and eleven criteria to evaluate them. Criteria are accurately chosen in order to cover the most important parameters that impact on the mining method selection, such as geological and geotechnical properties, economic parameters and geographical factors. The AHP is used to analyze the structure of the mining method selection problem and to determine weights of the criteria, and PROMETHEE method is used to obtain the final ranking and to make a sensitivity analysis by changing the weights. The results have shown that the proposed integrated method can be successfully used in solving mining engineering problems.

  17. The impact of the CartoSound® image directly acquired from the left atrium for integration in atrial fibrillation ablation.

    PubMed

    Kaseno, Kenichi; Hisazaki, Kaori; Nakamura, Kohki; Ikeda, Etsuko; Hasegawa, Kanae; Aoyama, Daisetsu; Shiomi, Yuichiro; Ikeda, Hiroyuki; Morishita, Tetsuji; Ishida, Kentaro; Amaya, Naoki; Uzui, Hiroyasu; Tada, Hiroshi

    2018-04-14

    Intracardiac echocardiographic (ICE) imaging might be useful for integrating three-dimensional computed tomographic (CT) images for left atrial (LA) catheter navigation during atrial fibrillation (AF) ablation. However, the optimal CT image integration method using ICE has not been established. This study included 52 AF patients who underwent successful circumferential pulmonary vein isolation (CPVI). In all patients, CT image integration was performed after the CPVI with the following two methods: (1) using ICE images of the LA derived from the right atrium and right ventricular outflow tract (RA-merge) and (2) using ICE images of the LA directly derived from the LA added to the image for the RA-merge (LA-merge). The accuracy of these two methods was assessed by the distances between the integrated CT image and ICE image (ICE-to-CT distance), and between the CT image and actual ablated sites for the CPVI (CT-to-ABL distance). The mean ICE-to-CT distance was comparable between the two methods (RA-merge = 1.6 ± 0.5 mm, LA-merge = 1.7 ± 0.4 mm; p = 0.33). However, the mean CT-to-ABL distance was shorter for the LA-merge (2.1 ± 0.6 mm) than RA-merge (2.5 ± 0.8 mm; p < 0.01). The LA, especially the left-sided PVs and LA roof, was more sharply delineated by direct LA imaging, and whereas the greatest CT-to-ABL distance was observed at the roof portion of the left superior PV (3.7 ± 2.8 mm) after the RA-merge, it improved to 2.6 ± 1.9 mm after the LA-merge (p < 0.01). Additional ICE images of the LA directly acquired from the LA might lead to a greater accuracy of the CT image integration for the CVPI.

  18. 77 FR 67063 - VA Directive 0005 on Scientific Integrity

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-08

    ... policies that: Foster a culture of transparency, integrity, and ethical behavior in the development and... provided to the VA's Office of Inspector General (OIG), the Office of Government Ethics, and Congress. VA...: VA has amended Directive 0005, ] 5.b., to state that ``VA policy provides an ethical and accountable...

  19. Electrohydrodynamic direct printing on hydrogel: a novel method to obtain fine fibers

    NASA Astrophysics Data System (ADS)

    Liu, Yuanyuan; Jiang, Chen; Liu, Yi; Li, Dongdong; Hu, Qingxi

    2016-09-01

    In this study, we proposed a novel method to obtain fine fibers: electrohydrodynamic (EHD) direct printing PCL on hydrogel. The effects of applied voltage, flow rate, plotting speed, hydrogel viscosity on the EHD direct writing process were investigated to obtain the most appropriate set of process conditions. We also compared the fibers obtained from this method with traditional EHD which deposited on aluminum and ethanol-based collectors. We found that fibers collected on the hydrogel were thinner and exhibited pores on the surface due to the hydrogel's facilitation of organic solvents' volatilization in the PCL fibers, which can benefit the attachment of cells. Besides, in our previous study, we found the freeze-thaw crosslinking process could greatly increase mechanical properties of the hydrogel used in our research, so this integration will not only mimic the composition of ECM which is a composite structure with a combination of fibrous proteins within a gelatinous grounded substance but also improve the mechanical properties of the scaffold. This novel method will broaden the application of EHD technology in the field of tissue engineering and other related areas.

  20. Multiple methods integration for structural mechanics analysis and design

    NASA Technical Reports Server (NTRS)

    Housner, J. M.; Aminpour, M. A.

    1991-01-01

    A new research area of multiple methods integration is proposed for joining diverse methods of structural mechanics analysis which interact with one another. Three categories of multiple methods are defined: those in which a physical interface are well defined; those in which a physical interface is not well-defined, but selected; and those in which the interface is a mathematical transformation. Two fundamental integration procedures are presented that can be extended to integrate various methods (e.g., finite elements, Rayleigh Ritz, Galerkin, and integral methods) with one another. Since the finite element method will likely be the major method to be integrated, its enhanced robustness under element distortion is also examined and a new robust shell element is demonstrated.

  1. A study of direct moxibustion using mathematical methods.

    PubMed

    Liu, Miao; Kauh, Sang Ken; Lim, Sabina

    2012-01-01

    Direct moxibustion is an important and widely used treatment method in traditional medical science. The use of a mathematical method to analyse direct moxibustion treatment is necessary and helpful in exploring the new direct moxibustion instruments and their standardisation. Thus, this paper aims to use a mathematical method to study direct moxibustion in skin to demonstrate a direct relationship between direct moxibustion and skin stimuli. In this paper, the transient thermal response of skin layers is analysed to study direct moxibustion using the data got from standardised method to measure the temperature of a burning moxa cone. Numerical simulations based on an appropriate finite element model are developed to predict the heat transfer, thermal damage and thermal stress distribution of barley moxa cones and jujube moxa cones in the skin tissue. The results are verified by the ancient literatures of traditional Chinese medicine and clinical application, and showed that mathematical method can be a good interface between moxa cone and skin tissue providing the numerical value basis for moxibustion.

  2. Methods for biological data integration: perspectives and challenges

    PubMed Central

    Gligorijević, Vladimir; Pržulj, Nataša

    2015-01-01

    Rapid technological advances have led to the production of different types of biological data and enabled construction of complex networks with various types of interactions between diverse biological entities. Standard network data analysis methods were shown to be limited in dealing with such heterogeneous networked data and consequently, new methods for integrative data analyses have been proposed. The integrative methods can collectively mine multiple types of biological data and produce more holistic, systems-level biological insights. We survey recent methods for collective mining (integration) of various types of networked biological data. We compare different state-of-the-art methods for data integration and highlight their advantages and disadvantages in addressing important biological problems. We identify the important computational challenges of these methods and provide a general guideline for which methods are suited for specific biological problems, or specific data types. Moreover, we propose that recent non-negative matrix factorization-based approaches may become the integration methodology of choice, as they are well suited and accurate in dealing with heterogeneous data and have many opportunities for further development. PMID:26490630

  3. Pulling It Together: Using Integrative Assignments as Empirical Direct Measures of Student Learning for Learning Community Program Assessment

    ERIC Educational Resources Information Center

    Huerta, Juan Carlos; Sperry, Rita

    2013-01-01

    This article outlines a systematic and manageable method for learning community program assessment based on collecting empirical direct measures of student learning. Developed at Texas A&M University--Corpus Christi where all full-time, first-year students are in learning communities, the approach ties integrative assignment design to a rubric…

  4. A Ratiometric Wavelength Measurement Based on a Silicon-on-Insulator Directional Coupler Integrated Device

    PubMed Central

    Wang, Pengfei; Hatta, Agus Muhamad; Zhao, Haoyu; Zheng, Jie; Farrell, Gerald; Brambilla, Gilberto

    2015-01-01

    A ratiometric wavelength measurement based on a Silicon-on-Insulator (SOI) integrated device is proposed and designed, which consists of directional couplers acting as two edge filters with opposite spectral responses. The optimal separation distance between two parallel silicon waveguides and the interaction length of the directional coupler are designed to meet the desired spectral response by using local supermodes. The wavelength discrimination ability of the designed ratiometric structure is demonstrated by a beam propagation method numerically and then is verified experimentally. The experimental results have shown a general agreement with the theoretical models. The ratiometric wavelength system demonstrates a resolution of better than 50 pm at a wavelength around 1550 nm with ease of assembly and calibration. PMID:26343668

  5. Direct Discrete Method for Neutronic Calculations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vosoughi, Naser; Akbar Salehi, Ali; Shahriari, Majid

    The objective of this paper is to introduce a new direct method for neutronic calculations. This method which is named Direct Discrete Method, is simpler than the neutron Transport equation and also more compatible with physical meaning of problems. This method is based on physic of problem and with meshing of the desired geometry, writing the balance equation for each mesh intervals and with notice to the conjunction between these mesh intervals, produce the final discrete equations series without production of neutron transport differential equation and mandatory passing from differential equation bridge. We have produced neutron discrete equations for amore » cylindrical shape with two boundary conditions in one group energy. The correction of the results from this method are tested with MCNP-4B code execution. (authors)« less

  6. Future Directions of Electromagnetic Methods for Hydrocarbon Applications

    NASA Astrophysics Data System (ADS)

    Strack, K. M.

    2014-01-01

    For hydrocarbon applications, seismic exploration is the workhorse of the industry. Only in the borehole, electromagnetic (EM) methods play a dominant role, as they are mostly used to determine oil reserves and to distinguish water from oil-bearing zones. Throughout the past 60 years, we had several periods with an increased interest in EM. This increased with the success of the marine EM industry and now electromagnetics in general is considered for many new applications. The classic electromagnetic methods are borehole, onshore and offshore, and airborne EM methods. Airborne is covered elsewhere (see Smith, this issue). Marine EM material is readily available from the service company Web sites, and here I will only mention some future technical directions that are visible. The marine EM success is being carried back to the onshore market, fueled by geothermal and unconventional hydrocarbon applications. Oil companies are listening to pro-EM arguments, but still are hesitant to go through the learning exercises as early adopters. In particular, the huge business drivers of shale hydrocarbons and reservoir monitoring will bring markets many times bigger than the entire marine EM market. Additional applications include support for seismic operations, sub-salt, and sub-basalt, all areas where seismic exploration is costly and inefficient. Integration with EM will allow novel seismic methods to be applied. In the borehole, anisotropy measurements, now possible, form the missing link between surface measurements and ground truth. Three-dimensional (3D) induction measurements are readily available from several logging contractors. The trend to logging-while-drilling measurements will continue with many more EM technologies, and the effort of controlling the drill bit while drilling including look-ahead-and-around the drill bit is going on. Overall, the market for electromagnetics is increasing, and a demand for EM capable professionals will continue. The emphasis will

  7. A low-level stress measurement method by integrating white light photoelasticity and spectrometry

    NASA Astrophysics Data System (ADS)

    Sung, Po-Chi; Wang, Wei-Chung; Hwang, Chi-Hung; Lai, Guan-Ting

    2018-01-01

    To face the increasing demand of residual stress measurement in many hi-tech industries, the integration of photoelasticity and advanced image acquisition equipment is a natural trend. With the integration of photoelasticity and spectrometry, the measurement capability of low-level stress and the stress in low birefringence materials can be enhanced. In fact, there is a significant correlation between the stress level and transmissivity spectrum. The key of the stress measurement method proposed in this paper is to find this scarcely explored correlation. By analyzing the periodic extinction phenomenon of isochromatic fringe pattern obtained from white light photoelasticity and the equation of transmissivity spectrum expressed in stress and wavelength, a three-dimensional (3D) systematic relationship of transmissivity with stress and wavelength can be established. By applying the 3D systematic transmissivity with stress and wavelength, the stress value can be determined directly from the transmissivity of the light transmitted through the polariscope. Moreover, when the proposed method is employed, the required parameters can be directly obtained from the database. There is no need to know the wavelength-dependent stress-optic coefficient beforehand. Glass, a very low birefringence material, was used to confirm the feasibility of the proposed method. Two regression approaches to search the transmissivity extremities were attempted to find the optimum systematic relationship.

  8. A Numerical Method for Integrating Orbits

    NASA Astrophysics Data System (ADS)

    Sahakyan, Karen P.; Melkonyan, Anahit A.; Hayrapetyan, S. R.

    2007-08-01

    A numerical method based of trigonometric polynomials for integrating of ordinary differential equations of first and second order is suggested. This method is a trigonometric analogue of Everhart's method and can be especially useful for periodical trajectories.

  9. Evaluating marginal likelihood with thermodynamic integration method and comparison with several other numerical methods

    DOE PAGES

    Liu, Peigui; Elshall, Ahmed S.; Ye, Ming; ...

    2016-02-05

    Evaluating marginal likelihood is the most critical and computationally expensive task, when conducting Bayesian model averaging to quantify parametric and model uncertainties. The evaluation is commonly done by using Laplace approximations to evaluate semianalytical expressions of the marginal likelihood or by using Monte Carlo (MC) methods to evaluate arithmetic or harmonic mean of a joint likelihood function. This study introduces a new MC method, i.e., thermodynamic integration, which has not been attempted in environmental modeling. Instead of using samples only from prior parameter space (as in arithmetic mean evaluation) or posterior parameter space (as in harmonic mean evaluation), the thermodynamicmore » integration method uses samples generated gradually from the prior to posterior parameter space. This is done through a path sampling that conducts Markov chain Monte Carlo simulation with different power coefficient values applied to the joint likelihood function. The thermodynamic integration method is evaluated using three analytical functions by comparing the method with two variants of the Laplace approximation method and three MC methods, including the nested sampling method that is recently introduced into environmental modeling. The thermodynamic integration method outperforms the other methods in terms of their accuracy, convergence, and consistency. The thermodynamic integration method is also applied to a synthetic case of groundwater modeling with four alternative models. The application shows that model probabilities obtained using the thermodynamic integration method improves predictive performance of Bayesian model averaging. As a result, the thermodynamic integration method is mathematically rigorous, and its MC implementation is computationally general for a wide range of environmental problems.« less

  10. Method to manage integration error in the Green-Kubo method.

    PubMed

    Oliveira, Laura de Sousa; Greaney, P Alex

    2017-02-01

    The Green-Kubo method is a commonly used approach for predicting transport properties in a system from equilibrium molecular dynamics simulations. The approach is founded on the fluctuation dissipation theorem and relates the property of interest to the lifetime of fluctuations in its thermodynamic driving potential. For heat transport, the lattice thermal conductivity is related to the integral of the autocorrelation of the instantaneous heat flux. A principal source of error in these calculations is that the autocorrelation function requires a long averaging time to reduce remnant noise. Integrating the noise in the tail of the autocorrelation function becomes conflated with physically important slow relaxation processes. In this paper we present a method to quantify the uncertainty on transport properties computed using the Green-Kubo formulation based on recognizing that the integrated noise is a random walk, with a growing envelope of uncertainty. By characterizing the noise we can choose integration conditions to best trade off systematic truncation error with unbiased integration noise, to minimize uncertainty for a given allocation of computational resources.

  11. Method to manage integration error in the Green-Kubo method

    NASA Astrophysics Data System (ADS)

    Oliveira, Laura de Sousa; Greaney, P. Alex

    2017-02-01

    The Green-Kubo method is a commonly used approach for predicting transport properties in a system from equilibrium molecular dynamics simulations. The approach is founded on the fluctuation dissipation theorem and relates the property of interest to the lifetime of fluctuations in its thermodynamic driving potential. For heat transport, the lattice thermal conductivity is related to the integral of the autocorrelation of the instantaneous heat flux. A principal source of error in these calculations is that the autocorrelation function requires a long averaging time to reduce remnant noise. Integrating the noise in the tail of the autocorrelation function becomes conflated with physically important slow relaxation processes. In this paper we present a method to quantify the uncertainty on transport properties computed using the Green-Kubo formulation based on recognizing that the integrated noise is a random walk, with a growing envelope of uncertainty. By characterizing the noise we can choose integration conditions to best trade off systematic truncation error with unbiased integration noise, to minimize uncertainty for a given allocation of computational resources.

  12. Path-integral method for the source apportionment of photochemical pollutants

    NASA Astrophysics Data System (ADS)

    Dunker, A. M.

    2015-06-01

    A new, path-integral method is presented for apportioning the concentrations of pollutants predicted by a photochemical model to emissions from different sources. A novel feature of the method is that it can apportion the difference in a species concentration between two simulations. For example, the anthropogenic ozone increment, which is the difference between a simulation with all emissions present and another simulation with only the background (e.g., biogenic) emissions included, can be allocated to the anthropogenic emission sources. The method is based on an existing, exact mathematical equation. This equation is applied to relate the concentration difference between simulations to line or path integrals of first-order sensitivity coefficients. The sensitivities describe the effects of changing the emissions and are accurately calculated by the decoupled direct method. The path represents a continuous variation of emissions between the two simulations, and each path can be viewed as a separate emission-control strategy. The method does not require auxiliary assumptions, e.g., whether ozone formation is limited by the availability of volatile organic compounds (VOCs) or nitrogen oxides (NOx), and can be used for all the species predicted by the model. A simplified configuration of the Comprehensive Air Quality Model with Extensions (CAMx) is used to evaluate the accuracy of different numerical integration procedures and the dependence of the source contributions on the path. A Gauss-Legendre formula using three or four points along the path gives good accuracy for apportioning the anthropogenic increments of ozone, nitrogen dioxide, formaldehyde, and nitric acid. Source contributions to these increments were obtained for paths representing proportional control of all anthropogenic emissions together, control of NOx emissions before VOC emissions, and control of VOC emissions before NOx emissions. There are similarities in the source contributions from the

  13. Path-integral method for the source apportionment of photochemical pollutants

    NASA Astrophysics Data System (ADS)

    Dunker, A. M.

    2014-12-01

    A new, path-integral method is presented for apportioning the concentrations of pollutants predicted by a photochemical model to emissions from different sources. A novel feature of the method is that it can apportion the difference in a species concentration between two simulations. For example, the anthropogenic ozone increment, which is the difference between a simulation with all emissions present and another simulation with only the background (e.g., biogenic) emissions included, can be allocated to the anthropogenic emission sources. The method is based on an existing, exact mathematical equation. This equation is applied to relate the concentration difference between simulations to line or path integrals of first-order sensitivity coefficients. The sensitivities describe the effects of changing the emissions and are accurately calculated by the decoupled direct method. The path represents a continuous variation of emissions between the two simulations, and each path can be viewed as a separate emission-control strategy. The method does not require auxiliary assumptions, e.g., whether ozone formation is limited by the availability of volatile organic compounds (VOC's) or nitrogen oxides (NOx), and can be used for all the species predicted by the model. A simplified configuration of the Comprehensive Air Quality Model with Extensions is used to evaluate the accuracy of different numerical integration procedures and the dependence of the source contributions on the path. A Gauss-Legendre formula using 3 or 4 points along the path gives good accuracy for apportioning the anthropogenic increments of ozone, nitrogen dioxide, formaldehyde, and nitric acid. Source contributions to these increments were obtained for paths representing proportional control of all anthropogenic emissions together, control of NOx emissions before VOC emissions, and control of VOC emissions before NOx emissions. There are similarities in the source contributions from the three paths but

  14. Comparison of haemoglobin estimates using direct & indirect cyanmethaemoglobin methods.

    PubMed

    Bansal, Priyanka Gupta; Toteja, Gurudayal Singh; Bhatia, Neena; Gupta, Sanjeev; Kaur, Manpreet; Adhikari, Tulsi; Garg, Ashok Kumar

    2016-10-01

    Estimation of haemoglobin is the most widely used method to assess anaemia. Although direct cyanmethaemoglobin method is the recommended method for estimation of haemoglobin, but it may not be feasible under field conditions. Hence, the present study was undertaken to compare indirect cyanmethaemoglobin method against the conventional direct method for haemoglobin estimation. Haemoglobin levels were estimated for 888 adolescent girls aged 11-18 yr residing in an urban slum in Delhi by both direct and indirect cyanmethaemoglobin methods, and the results were compared. The mean haemoglobin levels for 888 whole blood samples estimated by direct and indirect cyanmethaemoglobin method were 116.1 ± 12.7 and 110.5 ± 12.5 g/l, respectively, with a mean difference of 5.67 g/l (95% confidence interval: 5.45 to 5.90, P<0.001); which is equivalent to 0.567 g%. The prevalence of anaemia was reported as 59.6 and 78.2 per cent by direct and indirect methods, respectively. Sensitivity and specificity of indirect cyanmethaemoglobin method were 99.2 and 56.4 per cent, respectively. Using regression analysis, prediction equation was developed for indirect haemoglobin values. The present findings revealed that indirect cyanmethaemoglobin method overestimated the prevalence of anaemia as compared to the direct method. However, if a correction factor is applied, indirect method could be successfully used for estimating true haemoglobin level. More studies should be undertaken to establish agreement and correction factor between direct and indirect cyanmethaemoglobin methods.

  15. High-order Path Integral Monte Carlo methods for solving strongly correlated fermion problems

    NASA Astrophysics Data System (ADS)

    Chin, Siu A.

    2015-03-01

    In solving for the ground state of a strongly correlated many-fermion system, the conventional second-order Path Integral Monte Carlo method is plagued with the sign problem. This is due to the large number of anti-symmetric free fermion propagators that are needed to extract the square of the ground state wave function at large imaginary time. In this work, I show that optimized fourth-order Path Integral Monte Carlo methods, which uses no more than 5 free-fermion propagators, in conjunction with the use of the Hamiltonian energy estimator, can yield accurate ground state energies for quantum dots with up to 20 polarized electrons. The correlations are directly built-in and no explicit wave functions are needed. This work is supported by the Qatar National Research Fund NPRP GRANT #5-674-1-114.

  16. Methods of conditioning direct methanol fuel cells

    DOEpatents

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

    Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

  17. Study of Shallow Low-Enthalpy Geothermal Resources Using Integrated Geophysical Methods

    NASA Astrophysics Data System (ADS)

    De Giorgi, Lara; Leucci, Giovanni

    2015-02-01

    The paper is focused on low enthalpy geothermal exploration performed in south Italy and provides an integrated presentation of geological, hydrogeological, and geophysical surveys carried out in the area of municipality of Lecce. Geological and hydrogeological models were performed using the stratigraphical data from 51 wells. A ground-water flow (direction and velocity) model was obtained. Using the same wells data, the ground-water annual temperature was modeled. Furthermore, the ground surface temperature records from ten meteorological stations were studied. This allowed us to obtain a model related to the variations of the temperature at different depths in the subsoil. Integrated geophysical surveys were carried out in order to explore the low-enthalpy geothermal fluids and to evaluate the results of the model. Electrical resistivity tomography (ERT) and self-potential (SP) methods were used. The results obtained upon integrating the geophysical data with the models show a low-enthalpy geothermal resource constituted by a shallow ground-water system.

  18. Integrated force method versus displacement method for finite element analysis

    NASA Technical Reports Server (NTRS)

    Patnaik, S. N.; Berke, L.; Gallagher, R. H.

    1991-01-01

    A novel formulation termed the integrated force method (IFM) has been developed in recent years for analyzing structures. In this method all the internal forces are taken as independent variables, and the system equilibrium equations (EEs) are integrated with the global compatibility conditions (CCs) to form the governing set of equations. In IFM the CCs are obtained from the strain formulation of St. Venant, and no choices of redundant load systems have to be made, in constrast to the standard force method (SFM). This property of IFM allows the generation of the governing equation to be automated straightforwardly, as it is in the popular stiffness method (SM). In this report IFM and SM are compared relative to the structure of their respective equations, their conditioning, required solution methods, overall computational requirements, and convergence properties as these factors influence the accuracy of the results. Overall, this new version of the force method produces more accurate results than the stiffness method for comparable computational cost.

  19. Integrated force method versus displacement method for finite element analysis

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Berke, Laszlo; Gallagher, Richard H.

    1990-01-01

    A novel formulation termed the integrated force method (IFM) has been developed in recent years for analyzing structures. In this method all the internal forces are taken as independent variables, and the system equilibrium equations (EE's) are integrated with the global compatibility conditions (CC's) to form the governing set of equations. In IFM the CC's are obtained from the strain formulation of St. Venant, and no choices of redundant load systems have to be made, in constrast to the standard force method (SFM). This property of IFM allows the generation of the governing equation to be automated straightforwardly, as it is in the popular stiffness method (SM). In this report IFM and SM are compared relative to the structure of their respective equations, their conditioning, required solution methods, overall computational requirements, and convergence properties as these factors influence the accuracy of the results. Overall, this new version of the force method produces more accurate results than the stiffness method for comparable computational cost.

  20. A high-order boundary integral method for surface diffusions on elastically stressed axisymmetric rods.

    PubMed

    Li, Xiaofan; Nie, Qing

    2009-07-01

    Many applications in materials involve surface diffusion of elastically stressed solids. Study of singularity formation and long-time behavior of such solid surfaces requires accurate simulations in both space and time. Here we present a high-order boundary integral method for an elastically stressed solid with axi-symmetry due to surface diffusions. In this method, the boundary integrals for isotropic elasticity in axi-symmetric geometry are approximated through modified alternating quadratures along with an extrapolation technique, leading to an arbitrarily high-order quadrature; in addition, a high-order (temporal) integration factor method, based on explicit representation of the mean curvature, is used to reduce the stability constraint on time-step. To apply this method to a periodic (in axial direction) and axi-symmetric elastically stressed cylinder, we also present a fast and accurate summation method for the periodic Green's functions of isotropic elasticity. Using the high-order boundary integral method, we demonstrate that in absence of elasticity the cylinder surface pinches in finite time at the axis of the symmetry and the universal cone angle of the pinching is found to be consistent with the previous studies based on a self-similar assumption. In the presence of elastic stress, we show that a finite time, geometrical singularity occurs well before the cylindrical solid collapses onto the axis of symmetry, and the angle of the corner singularity on the cylinder surface is also estimated.

  1. Achieving Integration in Mixed Methods Designs—Principles and Practices

    PubMed Central

    Fetters, Michael D; Curry, Leslie A; Creswell, John W

    2013-01-01

    Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. PMID:24279835

  2. Architectural constraints are a major factor reducing path integration accuracy in the rat head direction cell system.

    PubMed

    Page, Hector J I; Walters, Daniel; Stringer, Simon M

    2015-01-01

    Head direction cells fire to signal the direction in which an animal's head is pointing. They are able to track head direction using only internally-derived information (path integration)In this simulation study we investigate the factors that affect path integration accuracy. Specifically, two major limiting factors are identified: rise time, the time after stimulation it takes for a neuron to start firing, and the presence of symmetric non-offset within-layer recurrent collateral connectivity. On the basis of the latter, the important prediction is made that head direction cell regions directly involved in path integration will not contain this type of connectivity; giving a theoretical explanation for architectural observations. Increased neuronal rise time is found to slow path integration, and the slowing effect for a given rise time is found to be more severe in the context of short conduction delays. Further work is suggested on the basis of our findings, which represent a valuable contribution to understanding of the head direction cell system.

  3. Indirect (source-free) integration method. I. Wave-forms from geodesic generic orbits of EMRIs

    NASA Astrophysics Data System (ADS)

    Ritter, Patxi; Aoudia, Sofiane; Spallicci, Alessandro D. A. M.; Cordier, Stéphane

    2016-12-01

    The Regge-Wheeler-Zerilli (RWZ) wave-equation describes Schwarzschild-Droste black hole perturbations. The source term contains a Dirac distribution and its derivative. We have previously designed a method of integration in time domain. It consists of a finite difference scheme where analytic expressions, dealing with the wave-function discontinuity through the jump conditions, replace the direct integration of the source and the potential. Herein, we successfully apply the same method to the geodesic generic orbits of EMRI (Extreme Mass Ratio Inspiral) sources, at second order. An EMRI is a Compact Star (CS) captured by a Super-Massive Black Hole (SMBH). These are considered the best probes for testing gravitation in strong regime. The gravitational wave-forms, the radiated energy and angular momentum at infinity are computed and extensively compared with other methods, for different orbits (circular, elliptic, parabolic, including zoom-whirl).

  4. Divergence preserving discrete surface integral methods for Maxwell's curl equations using non-orthogonal unstructured grids

    NASA Technical Reports Server (NTRS)

    Madsen, Niel K.

    1992-01-01

    Several new discrete surface integral (DSI) methods for solving Maxwell's equations in the time-domain are presented. These methods, which allow the use of general nonorthogonal mixed-polyhedral unstructured grids, are direct generalizations of the canonical staggered-grid finite difference method. These methods are conservative in that they locally preserve divergence or charge. Employing mixed polyhedral cells, (hexahedral, tetrahedral, etc.) these methods allow more accurate modeling of non-rectangular structures and objects because the traditional stair-stepped boundary approximations associated with the orthogonal grid based finite difference methods can be avoided. Numerical results demonstrating the accuracy of these new methods are presented.

  5. Methods for quantitative infrared directional-hemispherical and diffuse reflectance measurements using an FTIR and a commercial integrating sphere

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blake, Thomas A.; Johnson, Timothy J.; Tonkyn, Russell G.

    Infrared integrating sphere measurements of solid samples are important in providing reference data for contact, standoff and remote sensing applications. At the Pacific Northwest National Laboratory (PNNL) we have developed protocols to measure both the directional-hemispherical ( and diffuse (d) reflectances of powders, liquids, and disks of powders and solid materials using a commercially available, matte gold-coated integrating sphere and Fourier transform infrared spectrometer. Detailed descriptions of the sphere alignment and its use for making these reflectance measurements are given. Diffuse reflectance values were found to be dependent on the bidirectional reflection distribution function (BRDF) of the sample and themore » solid angle intercepted by the sphere’s specular exclusion port. To determine how well the sphere and protocols produce quantitative reflectance data, measurements were made of three diffuse and two specular standards prepared by the National institute of Standards and Technology (NIST, USA), LabSphere Infragold and Spectralon standards, hand-loaded sulfur and talc powder samples, and water. The five NIST standards behaved as expected: the three diffuse standards had a high degree of “diffuseness,” d/ = D > 0.9, whereas the two specular standards had D ≤ 0.03. The average absolute differences between the NIST and PNNL measurements of the NIST standards for both directional-hemispherical and diffuse reflectances are on the order of 0.01 reflectance units. Other quantitative differences between the PNNL-measured and calibration (where available) or literature reflectance values for these standards and materials are given and the possible origins of discrepancies are discussed. Random uncertainties and estimates of systematic uncertainties are presented. Corrections necessary to provide better agreement between the PNNL reflectance values as measured for the NIST standards and the NIST reflectance values for these same standards

  6. Three-dimensional integration of microoptical components buried inside photosensitive glass by femtosecond laser direct writing

    NASA Astrophysics Data System (ADS)

    Wang, Zhongke; Sugioka, Koji; Midorikawa, Katsumi

    2007-12-01

    We report the three-dimensional (3D) integration of microoptical components such as microlenses, micromirrors and optical waveguides in a single glass chip by femtosecond (fs) laser direct writing. First, two types of microoptical lenses were fabricated inside photosensitive Foturan glass by forming hollow microstructures using fs laser direct writing followed by thermal treatment, successive wet etching and additional annealing. One type of lens is the cylindrical microlens with a curvature radius R of 1.0 mm, and the other is the plano-convex microlens with radius R of 0.75 mm. Subsequently, by the continuous procedure of hollow microstructure fabrication, a micromirror was integrated with the plano-convex microlens in the single glass chip. Further integration of waveguides was performed by internal refractive index modification using fs laser direct writing after the hollow structure fabrication of the microlens and the micromirror. A demonstration of the laser beam transmission in the integrated optical microdevice shows that the 3D integration of waveguides with a micromirror and a microoptical lens in a single glass chip is highly effective for light beam guiding and focusing.

  7. Achieving integration in mixed methods designs-principles and practices.

    PubMed

    Fetters, Michael D; Curry, Leslie A; Creswell, John W

    2013-12-01

    Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs-exploratory sequential, explanatory sequential, and convergent-and through four advanced frameworks-multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. © Health Research and Educational Trust.

  8. Direct bioactive ceramics coating via reactive Growing Integration Layer method on α-Ti-alloy.

    PubMed

    Huang, Chi-Huang; Chen, Rong-Sheng; Yoshimura, Masahiro

    2017-07-01

    This paper demonstrates Ca-P-rich bio-ceramic and hydroxyapatite (HA) coatings formed directly from the solution of calcium acetate (CA) and sodium dihydrogen phosphate (SDP) on α-Ti-alloy substrates by Growing Integration Layer (GIL) technology under DC power supply. The composition of the α-Ti-alloy was Ti7Cu5Sn. The GIL coated films formed in 30min time with different voltages applied had porous and rough ceramic surfaces. They consisted mostly of various oxides like rutile, anatase, and calcium phosphates (including hydroxyapatite) that reduce corrosion rate and increase biocompatibility. An important feature was the reduction of Cu at the surfaces of the alloys. Furthermore, along with the applied voltage, the content of HA, the size of micro-pores, and hardness all increased, while the number of micro-pores in the ceramic membrane got reduced. The potential, current and resistance of corrosion were identified by potentiodynamic (PD) polarization and electrochemical impedance spectroscopy (EIS). The higher applied voltage improved the surface quality, HA formation rate, and the anti-corrosion behavior. Consequently, the samples - prepared at 350V and surface current density of 3A/cm 2 - possessed the most compact HA films, and also had the best corrosion resistance - in 0.9wt% NaCl solution at 37±1°C. Copyright © 2017. Published by Elsevier B.V.

  9. Optical electric field sensor sensitivity direction rerouting and enhancement using a passive integrated dipole antenna.

    PubMed

    Seng, Frederick; Yang, Zhenchao; King, Rex; Shumway, LeGrand; Stan, Nikola; Hammond, Alec; Warnick, Karl F; Schultz, Stephen

    2017-06-10

    This work introduces a passive dipole antenna integrated into the packaging of a slab-coupled optical sensor to enhance the directional sensitivity of electro-optic electric field measurements parallel to the fiber axis. Using the passive integrated dipole antenna described in this work, a sensor that can typically only sense fields transverse to the fiber direction is able to sense a 1.25 kV/m field along the fiber direction with a gain of 17.5. This is verified through simulation and experiment.

  10. New design of a triplexer using ring resonator integrated with directional coupler based on photonic crystals

    NASA Astrophysics Data System (ADS)

    Wu, Yaw-Dong; Shih, Tien-Tsorng; Lee, Jian-Jang

    2009-11-01

    In this paper, we proposed the design of directional coupler integrated with ring resonator based on two-dimensional photonic crystals (2D PCs) to develop a triplexer filter. It can be widely used as the fiber access network element for multiplexer-demultiplexer wavelength selective in fiber-to-the-home (FTTH) communication systems. The directional coupler is chosen to separate the wavelengths of 1490nm and 1310nm. The ring resonator separates the wavelength of 1550nm. The transmission efficiency is larger than 90%. Besides, the total size of propose triplexer is only 19μm×12μm. We present simulation results using the finite-difference time-domain (FDTD) method for the proposed structure.

  11. Fidelity of the Integrated Force Method Solution

    NASA Technical Reports Server (NTRS)

    Hopkins, Dale; Halford, Gary; Coroneos, Rula; Patnaik, Surya

    2002-01-01

    The theory of strain compatibility of the solid mechanics discipline was incomplete since St. Venant's 'strain formulation' in 1876. We have addressed the compatibility condition both in the continuum and the discrete system. This has lead to the formulation of the Integrated Force Method. A dual Integrated Force Method with displacement as the primal variable has also been formulated. A modest finite element code (IFM/Analyzers) based on the IFM theory has been developed. For a set of standard test problems the IFM results were compared with the stiffness method solutions and the MSC/Nastran code. For the problems IFM outperformed the existing methods. Superior IFM performance is attributed to simultaneous compliance of equilibrium equation and compatibility condition. MSC/Nastran organization expressed reluctance to accept the high fidelity IFM solutions. This report discusses the solutions to the examples. No inaccuracy was detected in the IFM solutions. A stiffness method code with a small programming effort can be improved to reap the many IFM benefits when implemented with the IFMD elements. Dr. Halford conducted a peer-review on the Integrated Force Method. Reviewers' response is included.

  12. Integrated Modeling of Optical Systems (IMOS): An Assessment and Future Directions

    NASA Technical Reports Server (NTRS)

    Moore, Gregory; Broduer, Steve (Technical Monitor)

    2001-01-01

    Integrated Modeling of Optical Systems (IMOS) is a finite element-based code combining structural, thermal, and optical ray-tracing capabilities in a single environment for analysis of space-based optical systems. We'll present some recent examples of IMOS usage and discuss future development directions. Due to increasing model sizes and a greater emphasis on multidisciplinary analysis and design, much of the anticipated future work will be in the areas of improved architecture, numerics, and overall performance and analysis integration.

  13. Path integration of head direction: updating a packet of neural activity at the correct speed using axonal conduction delays.

    PubMed

    Walters, Daniel; Stringer, Simon; Rolls, Edmund

    2013-01-01

    The head direction cell system is capable of accurately updating its current representation of head direction in the absence of visual input. This is known as the path integration of head direction. An important question is how the head direction cell system learns to perform accurate path integration of head direction. In this paper we propose a model of velocity path integration of head direction in which the natural time delay of axonal transmission between a linked continuous attractor network and competitive network acts as a timing mechanism to facilitate the correct speed of path integration. The model effectively learns a "look-up" table for the correct speed of path integration. In simulation, we show that the model is able to successfully learn two different speeds of path integration across two different axonal conduction delays, and without the need to alter any other model parameters. An implication of this model is that, by learning look-up tables for each speed of path integration, the model should exhibit a degree of robustness to damage. In simulations, we show that the speed of path integration is not significantly affected by degrading the network through removing a proportion of the cells that signal rotational velocity.

  14. Path Integration of Head Direction: Updating a Packet of Neural Activity at the Correct Speed Using Axonal Conduction Delays

    PubMed Central

    Walters, Daniel; Stringer, Simon; Rolls, Edmund

    2013-01-01

    The head direction cell system is capable of accurately updating its current representation of head direction in the absence of visual input. This is known as the path integration of head direction. An important question is how the head direction cell system learns to perform accurate path integration of head direction. In this paper we propose a model of velocity path integration of head direction in which the natural time delay of axonal transmission between a linked continuous attractor network and competitive network acts as a timing mechanism to facilitate the correct speed of path integration. The model effectively learns a “look-up” table for the correct speed of path integration. In simulation, we show that the model is able to successfully learn two different speeds of path integration across two different axonal conduction delays, and without the need to alter any other model parameters. An implication of this model is that, by learning look-up tables for each speed of path integration, the model should exhibit a degree of robustness to damage. In simulations, we show that the speed of path integration is not significantly affected by degrading the network through removing a proportion of the cells that signal rotational velocity. PMID:23526976

  15. Research on the Decision Method of Maintenance Materials Direct Supply

    NASA Astrophysics Data System (ADS)

    Zhu, Qian; Shi, Xiaopei; Liu, Shenyang; Luo, Guangxu; Zhu, Chen

    2018-05-01

    With the further development of civil military integration, more and more maintenance materials will be supplied by the factory directly. Aiming at the mode condition of maintenance materials factory direct supply, maintenance materials needs equipment support in the process of facing a number of direct supply manufacturers how to decision problems, using AHP, considering many factors optimization of direct supply manufacturers involved, and gives the weights of the evaluation indexes of the direct supply manufacturers to evaluate optimal. Finally, with 4 straights for the manufacturer as an example, considering the various evaluation indexes to carry out evaluation and drawing the correct evaluation of direct supply manufacturers, the best manufacturers direct supply is selected. An example shows that, AHP can provide scientific and theoretical basis to materials factory direct supply security.

  16. Developing a Method for Resolving NOx Emission Inventory Biases Using Discrete Kalman Filter Inversion, Direct Sensitivities, and Satellite-Based Columns

    EPA Science Inventory

    An inverse method was developed to integrate satellite observations of atmospheric pollutant column concentrations and direct sensitivities predicted by a regional air quality model in order to discern biases in the emissions of the pollutant precursors.

  17. Integrated methods for teaching population health.

    PubMed

    Sistrom, Maria Gilson; Zeigen, Laura; Jones, Melissa; Durham, Korana Fiol; Boudrot, Thomas

    2011-01-01

    The Institute of Medicine recommends reforms to public health education to better prepare the public health workforce. This study addresses the application of two of the recommended reforms in the population health nursing curriculum at one university: use of an ecological model and distance learning methods. Using interdisciplinary faculty, integrated teaching and learning methods, and a multimedia curriculum, this study examined the following question: can distance learning be designed to support learning goals and outcomes specific to an ecological approach and population health concepts in general? Course content was evaluated using students' perception of practice utility and understanding of population health concepts. Integrated teaching methods were evaluated using a scale as well as comparison to other student distance learning experiences within the university. Findings demonstrated that both the ecological model and distance learning methods were successfully used to teach population health to a large nursing student cohort. 2011, SLACK Incorporated.

  18. An estimation method for echo signal energy of pipe inner surface longitudinal crack detection by 2-D energy coefficients integration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, Shiyuan, E-mail: redaple@bit.edu.cn; Sun, Haoyu, E-mail: redaple@bit.edu.cn; Xu, Chunguang, E-mail: redaple@bit.edu.cn

    The echo signal energy is directly affected by the incident sound beam eccentricity or angle for thick-walled pipes inner longitudinal cracks detection. A method for analyzing the relationship between echo signal energy between the values of incident eccentricity is brought forward, which can be used to estimate echo signal energy when testing inside wall longitudinal crack of pipe, using mode-transformed compression wave adaptation of shear wave with water-immersion method, by making a two-dimension integration of “energy coefficient” in both circumferential and axial directions. The calculation model is founded for cylinder sound beam case, in which the refraction and reflection energymore » coefficients of different rays in the whole sound beam are considered different. The echo signal energy is calculated for a particular cylinder sound beam testing different pipes: a beam with a diameter of 0.5 inch (12.7mm) testing a φ279.4mm pipe and a φ79.4mm one. As a comparison, both the results of two-dimension integration and one-dimension (circumferential direction) integration are listed, and only the former agrees well with experimental results. The estimation method proves to be valid and shows that the usual method of simplifying the sound beam as a single ray for estimating echo signal energy and choosing optimal incident eccentricity is not so appropriate.« less

  19. An estimation method for echo signal energy of pipe inner surface longitudinal crack detection by 2-D energy coefficients integration

    NASA Astrophysics Data System (ADS)

    Zhou, Shiyuan; Sun, Haoyu; Xu, Chunguang; Cao, Xiandong; Cui, Liming; Xiao, Dingguo

    2015-03-01

    The echo signal energy is directly affected by the incident sound beam eccentricity or angle for thick-walled pipes inner longitudinal cracks detection. A method for analyzing the relationship between echo signal energy between the values of incident eccentricity is brought forward, which can be used to estimate echo signal energy when testing inside wall longitudinal crack of pipe, using mode-transformed compression wave adaptation of shear wave with water-immersion method, by making a two-dimension integration of "energy coefficient" in both circumferential and axial directions. The calculation model is founded for cylinder sound beam case, in which the refraction and reflection energy coefficients of different rays in the whole sound beam are considered different. The echo signal energy is calculated for a particular cylinder sound beam testing different pipes: a beam with a diameter of 0.5 inch (12.7mm) testing a φ279.4mm pipe and a φ79.4mm one. As a comparison, both the results of two-dimension integration and one-dimension (circumferential direction) integration are listed, and only the former agrees well with experimental results. The estimation method proves to be valid and shows that the usual method of simplifying the sound beam as a single ray for estimating echo signal energy and choosing optimal incident eccentricity is not so appropriate.

  20. Flow direction measurement criteria and techniques planned for the 40- by 80-/80- x 120-foot wind tunnel integrated systems tests

    NASA Technical Reports Server (NTRS)

    Zell, P. T.; Hoffmann, J.; Sandlin, D. R.

    1985-01-01

    A study was performed in order to develop the criteria for the selection of flow direction indicators for use in the Integrated Systems Tests (ISTs) of the 40 by 80/80 by 120 Foot Wind Tunnel System. The problems, requirements, and limitations of flow direction measurement in the wind tunnel were investigated. The locations and types of flow direction measurements planned in the facility were discussed. A review of current methods of flow direction measurement was made and the most suitable technique for each location was chosen. A flow direction vane for each location was chosen. A flow direction vane that employs a Hall Effect Transducer was then developed and evaluated for application during the ISTs.

  1. Error Reduction Methods for Integrated-path Differential-absorption Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Chen, Jeffrey R.; Numata, Kenji; Wu, Stewart T.

    2012-01-01

    We report new modeling and error reduction methods for differential-absorption optical-depth (DAOD) measurements of atmospheric constituents using direct-detection integrated-path differential-absorption lidars. Errors from laser frequency noise are quantified in terms of the line center fluctuation and spectral line shape of the laser pulses, revealing relationships verified experimentally. A significant DAOD bias is removed by introducing a correction factor. Errors from surface height and reflectance variations can be reduced to tolerable levels by incorporating altimetry knowledge and "log after averaging", or by pointing the laser and receiver to a fixed surface spot during each wavelength cycle to shorten the time of "averaging before log".

  2. Analysis of mixed-mode crack propagation using the boundary integral method

    NASA Technical Reports Server (NTRS)

    Mendelson, A.; Ghosn, L. J.

    1986-01-01

    Crack propagation in a rotating inner raceway of a high speed roller bearing is analyzed using the boundary integral equation method. The method consists of an edge crack in a plate under tension, upon which varying Hertzian stress fields are superimposed. A computer program for the boundary integral equation method was written using quadratic elements to determine the stress and displacement fields for discrete roller positions. Mode I and Mode II stress intensity factors and crack extension forces G sub 00 (energy release rate due to tensile opening mode) and G sub r0 (energy release rate due to shear displacement mode) were computed. These calculations permit determination of that crack growth angle for which the change in the crack extension forces is maximum. The crack driving force was found to be the alternating mixed-mode loading that occurs with each passage of the most heavily loaded roller. The crack is predicted to propagate in a step-like fashion alternating between radial and inclined segments, and this pattern was observed experimentally. The maximum changes DeltaG sub 00 and DeltaG sub r0 of the crack extension forces are found to be good measures of the crack propagation rate and direction.

  3. An Optimal Control Method for Maximizing the Efficiency of Direct Drive Ocean Wave Energy Extraction System

    PubMed Central

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability. PMID:25152913

  4. An optimal control method for maximizing the efficiency of direct drive ocean wave energy extraction system.

    PubMed

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability.

  5. Femtosecond direct space-to-time pulse shaping in an integrated-optic configuration.

    PubMed

    Leaird, D E; Weiner, A M

    2004-07-01

    We demonstrate femtosecond operation of an integrated-optic direct space-to-time pulse shaper for which there is a direct mapping (no Fourier transform) between the spatial position of the masking function and the temporal position in the output waveform. The apparatus is used to generate trains of more than 30 pulses as an ultrafast optical data packet over approximately an 80-ps temporal window.

  6. Integrated resonant micro-optical gyroscope and method of fabrication

    DOEpatents

    Vawter, G Allen [Albuquerque, NM; Zubrzycki, Walter J [Sandia Park, NM; Guo, Junpeng [Albuquerque, NM; Sullivan, Charles T [Albuquerque, NM

    2006-09-12

    An integrated optic gyroscope is disclosed which is based on a photonic integrated circuit (PIC) having a bidirectional laser source, a pair of optical waveguide phase modulators and a pair of waveguide photodetectors. The PIC can be connected to a passive ring resonator formed either as a coil of optical fiber or as a coiled optical waveguide. The lasing output from each end of the bidirectional laser source is phase modulated and directed around the passive ring resonator in two counterpropagating directions, with a portion of the lasing output then being detected to determine a rotation rate for the integrated optical gyroscope. The coiled optical waveguide can be formed on a silicon, glass or quartz substrate with a silicon nitride core and a silica cladding, while the PIC includes a plurality of III V compound semiconductor layers including one or more quantum well layers which are disordered in the phase modulators and to form passive optical waveguides.

  7. Direct PCR - A rapid method for multiplexed detection of different serotypes of Salmonella in enriched pork meat samples.

    PubMed

    Chin, Wai Hoe; Sun, Yi; Høgberg, Jonas; Quyen, Than Linh; Engelsmann, Pia; Wolff, Anders; Bang, Dang Duong

    2017-04-01

    Salmonellosis, an infectious disease caused by Salmonella spp., is one of the most common foodborne diseases. Isolation and identification of Salmonella by conventional bacterial culture method is time consuming. In response to the demand for rapid on line or at site detection of pathogens, in this study, we developed a multiplex Direct PCR method for rapid detection of different Salmonella serotypes directly from pork meat samples without any DNA purification steps. An inhibitor-resistant Phusion Pfu DNA polymerase was used to overcome PCR inhibition. Four pairs of primers including a pair of newly designed primers targeting Salmonella spp. at subtype level were incorporated in the multiplex Direct PCR. To maximize the efficiency of the Direct PCR, the ratio between sample and dilution buffer was optimized. The sensitivity and specificity of the multiplex Direct PCR were tested using naturally contaminated pork meat samples for detecting and subtyping of Salmonella spp. Conventional bacterial culture methods were used as reference to evaluate the performance of the multiplex Direct PCR. Relative accuracy, sensitivity and specificity of 98.8%; 97.6% and 100%, respectively, were achieved by the method. Application of the multiplex Direct PCR to detect Salmonella in pork meat at slaughter reduces the time of detection from 5 to 6 days by conventional bacterial culture and serotyping methods to 14 h (including 12 h enrichment time). Furthermore, the method poses a possibility of miniaturization and integration into a point-of-need Lab-on-a-chip system for rapid online pathogen detection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. From molecular engineering to process engineering: development of high-throughput screening methods in enzyme directed evolution.

    PubMed

    Ye, Lidan; Yang, Chengcheng; Yu, Hongwei

    2018-01-01

    With increasing concerns in sustainable development, biocatalysis has been recognized as a competitive alternative to traditional chemical routes in the past decades. As nature's biocatalysts, enzymes are able to catalyze a broad range of chemical transformations, not only with mild reaction conditions but also with high activity and selectivity. However, the insufficient activity or enantioselectivity of natural enzymes toward non-natural substrates limits their industrial application, while directed evolution provides a potent solution to this problem, thanks to its independence on detailed knowledge about the relationship between sequence, structure, and mechanism/function of the enzymes. A proper high-throughput screening (HTS) method is the key to successful and efficient directed evolution. In recent years, huge varieties of HTS methods have been developed for rapid evaluation of mutant libraries, ranging from in vitro screening to in vivo selection, from indicator addition to multi-enzyme system construction, and from plate screening to computation- or machine-assisted screening. Recently, there is a tendency to integrate directed evolution with metabolic engineering in biosynthesis, using metabolites as HTS indicators, which implies that directed evolution has transformed from molecular engineering to process engineering. This paper aims to provide an overview of HTS methods categorized based on the reaction principles or types by summarizing related studies published in recent years including the work from our group, to discuss assay design strategies and typical examples of HTS methods, and to share our understanding on HTS method development for directed evolution of enzymes involved in specific catalytic reactions or metabolic pathways.

  9. Heading-vector navigation based on head-direction cells and path integration.

    PubMed

    Kubie, John L; Fenton, André A

    2009-05-01

    Insect navigation is guided by heading vectors that are computed by path integration. Mammalian navigation models, on the other hand, are typically based on map-like place representations provided by hippocampal place cells. Such models compute optimal routes as a continuous series of locations that connect the current location to a goal. We propose a "heading-vector" model in which head-direction cells or their derivatives serve both as key elements in constructing the optimal route and as the straight-line guidance during route execution. The model is based on a memory structure termed the "shortcut matrix," which is constructed during the initial exploration of an environment when a set of shortcut vectors between sequential pairs of visited waypoint locations is stored. A mechanism is proposed for calculating and storing these vectors that relies on a hypothesized cell type termed an "accumulating head-direction cell." Following exploration, shortcut vectors connecting all pairs of waypoint locations are computed by vector arithmetic and stored in the shortcut matrix. On re-entry, when local view or place representations query the shortcut matrix with a current waypoint and goal, a shortcut trajectory is retrieved. Since the trajectory direction is in head-direction compass coordinates, navigation is accomplished by tracking the firing of head-direction cells that are tuned to the heading angle. Section 1 of the manuscript describes the properties of accumulating head-direction cells. It then shows how accumulating head-direction cells can store local vectors and perform vector arithmetic to perform path-integration-based homing. Section 2 describes the construction and use of the shortcut matrix for computing direct paths between any pair of locations that have been registered in the shortcut matrix. In the discussion, we analyze the advantages of heading-based navigation over map-based navigation. Finally, we survey behavioral evidence that nonhippocampal

  10. A direct potential fitting RKR method: Semiclassical vs. quantal comparisons

    NASA Astrophysics Data System (ADS)

    Tellinghuisen, Joel

    2016-12-01

    Quantal and semiclassical (SC) eigenvalues are compared for three diatomic molecular potential curves: the X state of CO, the X state of Rb2, and the A state of I2. The comparisons show higher levels of agreement than generally recognized, when the SC calculations incorporate a quantum defect correction to the vibrational quantum number, in keeping with the Kaiser modification. One particular aspect of this is better agreement between quantal and SC estimates of the zero-point vibrational energy, supporting the need for the Y00 correction in this context. The pursuit of a direct-potential-fitting (DPF) RKR method is motivated by the notion that some of the limitations of RKR potentials may be innate, from their generation by an exact inversion of approximate quantities: the vibrational energy Gυ and rotational constant Bυ from least-squares analysis of spectroscopic data. In contrast, the DPF RKR method resembles the quantal DPF methods now increasingly used to analyze diatomic spectral data, but with the eigenvalues obtained from SC phase integrals. Application of this method to the analysis of 9500 assigned lines in the I2A ← X spectrum fails to alter the quantal-SC disparities found for the A-state RKR curve from a previous analysis. On the other hand, the SC method can be much faster than the quantal method in exploratory work with different potential functions, where it is convenient to use finite-difference methods to evaluate the partial derivatives required in nonlinear fitting.

  11. Acetylcholine contributes to the integration of self-movement cues in head direction cells.

    PubMed

    Yoder, Ryan M; Chan, Jeremy H M; Taube, Jeffrey S

    2017-08-01

    Acetylcholine contributes to accurate performance on some navigational tasks, but details of its contribution to the underlying brain signals are not fully understood. The medial septal area provides widespread cholinergic input to various brain regions, but selective damage to medial septal cholinergic neurons generally has little effect on landmark-based navigation, or the underlying neural representations of location and directional heading in visual environments. In contrast, the loss of medial septal cholinergic neurons disrupts navigation based on path integration, but no studies have tested whether these path integration deficits are associated with disrupted head direction (HD) cell activity. Therefore, we evaluated HD cell responses to visual cue rotations in a familiar arena, and during navigation between familiar and novel arenas, after muscarinic receptor blockade with systemic atropine. Atropine treatment reduced the peak firing rate of HD cells, but failed to significantly affect other HD cell firing properties. Atropine also failed to significantly disrupt the dominant landmark control of the HD signal, even though we used a procedure that challenged this landmark control. In contrast, atropine disrupted HD cell stability during navigation between familiar and novel arenas, where path integration normally maintains a consistent HD cell signal across arenas. These results suggest that acetylcholine contributes to path integration, in part, by facilitating the use of idiothetic cues to maintain a consistent representation of directional heading. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. 29 CFR 4211.13 - Modifications to the direct attribution method.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Modifications to the direct attribution method. 4211.13... Changes Not Subject to PBGC Approval § 4211.13 Modifications to the direct attribution method. (a) Error in direct attribution method. The unfunded vested benefits allocated to a withdrawing employer under...

  13. Mixed methods in psychotherapy research: A review of method(ology) integration in psychotherapy science.

    PubMed

    Bartholomew, Theodore T; Lockard, Allison J

    2018-06-13

    Mixed methods can foster depth and breadth in psychological research. However, its use remains in development in psychotherapy research. Our purpose was to review the use of mixed methods in psychotherapy research. Thirty-one studies were identified via the PRISMA systematic review method. Using Creswell & Plano Clark's typologies to identify design characteristics, we assessed each study for rigor and how each used mixed methods. Key features of mixed methods designs and these common patterns were identified: (a) integration of clients' perceptions via mixing; (b) understanding group psychotherapy; (c) integrating methods with cases and small samples; (d) analyzing clinical data as qualitative data; and (e) exploring cultural identities in psychotherapy through mixed methods. The review is discussed with respect to the value of integrating multiple data in single studies to enhance psychotherapy research. © 2018 Wiley Periodicals, Inc.

  14. Calculation of transonic flows using an extended integral equation method

    NASA Technical Reports Server (NTRS)

    Nixon, D.

    1976-01-01

    An extended integral equation method for transonic flows is developed. In the extended integral equation method velocities in the flow field are calculated in addition to values on the aerofoil surface, in contrast with the less accurate 'standard' integral equation method in which only surface velocities are calculated. The results obtained for aerofoils in subcritical flow and in supercritical flow when shock waves are present compare satisfactorily with the results of recent finite difference methods.

  15. Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide.

    PubMed

    Borja, Angel; Bricker, Suzanne B; Dauer, Daniel M; Demetriades, Nicolette T; Ferreira, João G; Forbes, Anthony T; Hutchings, Pat; Jia, Xiaoping; Kenchington, Richard; Carlos Marques, João; Zhu, Changbo

    2008-09-01

    In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected

  16. Chromodomains direct integration of retrotransposons to heterochromatin

    PubMed Central

    Gao, Xiang; Hou, Yi; Ebina, Hirotaka; Levin, Henry L.; Voytas, Daniel F.

    2008-01-01

    The enrichment of mobile genetic elements in heterochromatin may be due, in part, to targeted integration. The chromoviruses are Ty3/gypsy retrotransposons with chromodomains at their integrase C termini. Chromodomains are logical determinants for targeting to heterochromatin, because the chromodomain of heterochromatin protein 1 (HP1) typically recognizes histone H3 K9 methylation, an epigenetic mark characteristic of heterochromatin. We describe three groups of chromoviruses based on amino acid sequence relationships of their integrase C termini. Genome sequence analysis indicates that representative chromoviruses from each group are enriched in gene-poor regions of the genome relative to other retrotransposons, and when fused to fluorescent marker proteins, the chromodomains target proteins to specific subnuclear foci coincident with heterochromatin. The chromodomain of the fungal element, MAGGY, interacts with histone H3 dimethyl- and trimethyl-K9, and when the MAGGY chromodomain is fused to integrase of the Schizosaccharomyces pombe Tf1 retrotransposon, new Tf1 insertions are directed to sites of H3 K9 methylation. Repetitive sequences such as transposable elements trigger the RNAi pathway resulting in their epigenetic modification. Our results suggest a dynamic interplay between retrotransposons and heterochromatin, wherein mobile elements recognize heterochromatin at the time of integration and then perpetuate the heterochromatic mark by triggering epigenetic modification. PMID:18256242

  17. Integration of Research Studies: Meta-Analysis of Research. Methods of Integrative Analysis; Final Report.

    ERIC Educational Resources Information Center

    Glass, Gene V.; And Others

    Integrative analysis, or what is coming to be known as meta-analysis, is the integration of the findings of many empirical research studies of a topic. Meta-analysis differs from traditional narrative forms of research reviewing in that it is more quantitative and statistical. Thus, the methods of meta-analysis are merely statistical methods,…

  18. The Contribution of Mixed Methods Research to the Field of Childhood Trauma: A Narrative Review Focused on Data Integration

    ERIC Educational Resources Information Center

    Boeije, Hennie; Slagt, Meike; van Wesel, Floryt

    2013-01-01

    In mixed methods research (MMR), integrating the quantitative and the qualitative components of a study is assumed to result in additional knowledge (or "yield"). This narrative review examines the extent to which MMR is used in the field of childhood trauma and provides directions for improving mixed methods studies in this field. A…

  19. Physicians' intention to leave direct patient care: an integrative review.

    PubMed

    Degen, Christiane; Li, Jian; Angerer, Peter

    2015-09-08

    In light of the growing shortage of physicians worldwide, the problem of physicians who intend to leave direct patient care has become more acute, particularly in terms of quality of care and health-care costs. A literature search was carried out following Cooper's five-stage model for conducting an integrative literature review. Database searches were made in MEDLINE, PsycINFO and Web of Science in May 2014. A total of 17 studies from five countries were identified and the study results synthesized. Measures and percentages of physicians' intention to leave varied between the studies. Variables associated with intention to leave were demographics, with age- and gender-specific findings, family or personal domain, working time and psychosocial working conditions, job-related well-being and other career-related aspects. Gender differences were identified in several risk clusters. Factors such as long working hours and work-family conflict were particularly relevant for female physicians' intention to leave. Health-care managers and policy-makers should take action to improve physicians' working hours and psychosocial working conditions in order to prevent a high rate of intention to leave and limit the number of physicians actually leaving direct patient care. Further research is needed on gender-specific needs in the workplace, the connection between intention to leave and actually leaving and measures of intention to leave as well as using qualitative methods to gain a deeper understanding and developing validated questionnaires.

  20. Approximation of the exponential integral (well function) using sampling methods

    NASA Astrophysics Data System (ADS)

    Baalousha, Husam Musa

    2015-04-01

    Exponential integral (also known as well function) is often used in hydrogeology to solve Theis and Hantush equations. Many methods have been developed to approximate the exponential integral. Most of these methods are based on numerical approximations and are valid for a certain range of the argument value. This paper presents a new approach to approximate the exponential integral. The new approach is based on sampling methods. Three different sampling methods; Latin Hypercube Sampling (LHS), Orthogonal Array (OA), and Orthogonal Array-based Latin Hypercube (OA-LH) have been used to approximate the function. Different argument values, covering a wide range, have been used. The results of sampling methods were compared with results obtained by Mathematica software, which was used as a benchmark. All three sampling methods converge to the result obtained by Mathematica, at different rates. It was found that the orthogonal array (OA) method has the fastest convergence rate compared with LHS and OA-LH. The root mean square error RMSE of OA was in the order of 1E-08. This method can be used with any argument value, and can be used to solve other integrals in hydrogeology such as the leaky aquifer integral.

  1. Direct toxicity assessment - Methods, evaluation, interpretation.

    PubMed

    Gruiz, Katalin; Fekete-Kertész, Ildikó; Kunglné-Nagy, Zsuzsanna; Hajdu, Csilla; Feigl, Viktória; Vaszita, Emese; Molnár, Mónika

    2016-09-01

    Direct toxicity assessment (DTA) results provide the scale of the actual adverse effect of contaminated environmental samples. DTA results are used in environmental risk management of contaminated water, soil and waste, without explicitly translating the results into chemical concentration. The end points are the same as in environmental toxicology in general, i.e. inhibition rate, decrease in the growth rate or in yield and the 'no effect' or the 'lowest effect' measurement points of the sample dilution-response curve. The measurement unit cannot be a concentration, since the contaminants and their content in the sample is unknown. Thus toxicity is expressed as the sample proportion causing a certain scale of inhibition or no inhibition. Another option for characterizing the scale of toxicity of an environmental sample is equivalencing. Toxicity equivalencing represents an interpretation tool which enables toxicity of unknown mixtures of chemicals be converted into the concentration of an equivalently toxic reference substance. Toxicity equivalencing, (i.e. expressing the toxicity of unknown contaminants as the concentration of the reference) makes DTA results better understandable for non-ecotoxicologists and other professionals educated and thinking based on the chemical model. This paper describes and discusses the role, the principles, the methodology and the interpretation of direct toxicity assessment (DTA) with the aim to contribute to the understanding of the necessity to integrate DTA results into environmental management of contaminated soil and water. The paper also introduces the benefits of the toxicity equivalency method. The use of DTA is illustrated through two case studies. The first case study focuses on DTA of treated wastewater with the aim to characterize the treatment efficacy of a biological wastewater treatment plant by frequent bioassaying. The second case study applied DTA to investigate the cover layers of two bauxite residue (red mud

  2. Exponential Methods for the Time Integration of Schroedinger Equation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cano, B.; Gonzalez-Pachon, A.

    2010-09-30

    We consider exponential methods of second order in time in order to integrate the cubic nonlinear Schroedinger equation. We are interested in taking profit of the special structure of this equation. Therefore, we look at symmetry, symplecticity and approximation of invariants of the proposed methods. That will allow to integrate till long times with reasonable accuracy. Computational efficiency is also our aim. Therefore, we make numerical computations in order to compare the methods considered and so as to conclude that explicit Lawson schemes projected on the norm of the solution are an efficient tool to integrate this equation.

  3. Application of integrated fluid-thermal-structural analysis methods

    NASA Technical Reports Server (NTRS)

    Wieting, Allan R.; Dechaumphai, Pramote; Bey, Kim S.; Thornton, Earl A.; Morgan, Ken

    1988-01-01

    Hypersonic vehicles operate in a hostile aerothermal environment which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response creating a multidisciplinary interaction. Interfacing state-of-the-art disciplinary analysis methods is not efficient, hence interdisciplinary analysis methods integrated into a single aerothermostructural analyzer are needed. The NASA Langley Research Center is developing such methods in an analyzer called LIFTS (Langley Integrated Fluid-Thermal-Structural) analyzer. The evolution and status of LIFTS is reviewed and illustrated through applications.

  4. Non-contact method for directing electrotaxis

    NASA Astrophysics Data System (ADS)

    Ahirwar, Dinesh K.; Nasser, Mohd W.; Jones, Travis H.; Sequin, Emily K.; West, Joseph D.; Henthorne, Timothy L.; Javor, Joshua; Kaushik, Aniruddha M.; Ganju, Ramesh K.; Subramaniam, Vish V.

    2015-06-01

    We present a method to induce electric fields and drive electrotaxis (galvanotaxis) without the need for electrodes to be in contact with the media containing the cell cultures. We report experimental results using a modification of the transmembrane assay, demonstrating the hindrance of migration of breast cancer cells (SCP2) when an induced a.c. electric field is present in the appropriate direction (i.e. in the direction of migration). Of significance is that migration of these cells is hindered at electric field strengths many orders of magnitude (5 to 6) below those previously reported for d.c. electrotaxis, and even in the presence of a chemokine (SDF-1α) or a growth factor (EGF). Induced a.c. electric fields applied in the direction of migration are also shown to hinder motility of non-transformed human mammary epithelial cells (MCF10A) in the presence of the growth factor EGF. In addition, we also show how our method can be applied to other cell migration assays (scratch assay), and by changing the coil design and holder, that it is also compatible with commercially available multi-well culture plates.

  5. Methods of geometrical integration in accelerator physics

    NASA Astrophysics Data System (ADS)

    Andrianov, S. N.

    2016-12-01

    In the paper we consider a method of geometric integration for a long evolution of the particle beam in cyclic accelerators, based on the matrix representation of the operator of particles evolution. This method allows us to calculate the corresponding beam evolution in terms of two-dimensional matrices including for nonlinear effects. The ideology of the geometric integration introduces in appropriate computational algorithms amendments which are necessary for preserving the qualitative properties of maps presented in the form of the truncated series generated by the operator of evolution. This formalism extends both on polarized and intense beams. Examples of practical applications are described.

  6. Direct Solve of Electrically Large Integral Equations for Problem Sizes to 1M Unknowns

    NASA Technical Reports Server (NTRS)

    Shaeffer, John

    2008-01-01

    Matrix methods for solving integral equations via direct solve LU factorization are presently limited to weeks to months of very expensive supercomputer time for problems sizes of several hundred thousand unknowns. This report presents matrix LU factor solutions for electromagnetic scattering problems for problem sizes to one million unknowns with thousands of right hand sides that run in mere days on PC level hardware. This EM solution is accomplished by utilizing the numerical low rank nature of spatially blocked unknowns using the Adaptive Cross Approximation for compressing the rank deficient blocks of the system Z matrix, the L and U factors, the right hand side forcing function and the final current solution. This compressed matrix solution is applied to a frequency domain EM solution of Maxwell's equations using standard Method of Moments approach. Compressed matrix storage and operations count leads to orders of magnitude reduction in memory and run time.

  7. Validity of an Integrative Method for Processing Physical Activity Data.

    PubMed

    Ellingson, Laura D; Schwabacher, Isaac J; Kim, Youngwon; Welk, Gregory J; Cook, Dane B

    2016-08-01

    Accurate assessments of both physical activity and sedentary behaviors are crucial to understand the health consequences of movement patterns and to track changes over time and in response to interventions. The study evaluates the validity of an integrative, machine learning method for processing activity monitor data in relation to a portable metabolic analyzer (Oxycon mobile [OM]) and direct observation (DO). Forty-nine adults (age 18-40 yr) each completed 5-min bouts of 15 activities ranging from sedentary to vigorous intensity in a laboratory setting while wearing ActiGraph (AG) on the hip, activPAL on the thigh, and OM. Estimates of energy expenditure (EE) and categorization of activity intensity were obtained from the AG processed with Lyden's sojourn (SOJ) method and from our new sojourns including posture (SIP) method, which integrates output from the AG and activPAL. Classification accuracy and estimates of EE were then compared with criterion measures (OM and DO) using confusion matrices and comparisons of the mean absolute error of log-transformed data (MAE ln Q). The SIP method had a higher overall classification agreement (79%, 95% CI = 75%-82%) than the SOJ (56%, 95% CI = 52%-59%) based on DO. Compared with OM, estimates of EE from SIP had lower mean absolute error of log-transformed data than SOJ for light-intensity (0.21 vs 0.27), moderate-intensity (0.33 vs 0.42), and vigorous-intensity (0.16 vs 0.35) activities. The SIP method was superior to SOJ for distinguishing between sedentary and light activities as well as estimating EE at higher intensities. Thus, SIP is recommended for research in which accuracy of measurement across the full range of activity intensities is of interest.

  8. EMERGY METHODS: VALUABLE INTEGRATED ASSESSMENT TOOLS

    EPA Science Inventory

    NHEERL's Atlantic Ecology Division is investigating emergy methods as tools for integrated assessment in several projects evaluating environmental impacts, policies, and alternatives for remediation and intervention. Emergy accounting is a methodology that provides a quantitative...

  9. The 'Arm Force Field' method to predict manual arm strength based on only hand location and force direction.

    PubMed

    La Delfa, Nicholas J; Potvin, Jim R

    2017-03-01

    This paper describes the development of a novel method (termed the 'Arm Force Field' or 'AFF') to predict manual arm strength (MAS) for a wide range of body orientations, hand locations and any force direction. This method used an artificial neural network (ANN) to predict the effects of hand location and force direction on MAS, and included a method to estimate the contribution of the arm's weight to the predicted strength. The AFF method predicted the MAS values very well (r 2  = 0.97, RMSD = 5.2 N, n = 456) and maintained good generalizability with external test data (r 2  = 0.842, RMSD = 13.1 N, n = 80). The AFF can be readily integrated within any DHM ergonomics software, and appears to be a more robust, reliable and valid method of estimating the strength capabilities of the arm, when compared to current approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. A flexible importance sampling method for integrating subgrid processes

    DOE PAGES

    Raut, E. K.; Larson, V. E.

    2016-01-29

    Numerical models of weather and climate need to compute grid-box-averaged rates of physical processes such as microphysics. These averages are computed by integrating subgrid variability over a grid box. For this reason, an important aspect of atmospheric modeling is spatial integration over subgrid scales. The needed integrals can be estimated by Monte Carlo integration. Monte Carlo integration is simple and general but requires many evaluations of the physical process rate. To reduce the number of function evaluations, this paper describes a new, flexible method of importance sampling. It divides the domain of integration into eight categories, such as the portion that containsmore » both precipitation and cloud, or the portion that contains precipitation but no cloud. It then allows the modeler to prescribe the density of sample points within each of the eight categories. The new method is incorporated into the Subgrid Importance Latin Hypercube Sampler (SILHS). Here, the resulting method is tested on drizzling cumulus and stratocumulus cases. In the cumulus case, the sampling error can be considerably reduced by drawing more sample points from the region of rain evaporation.« less

  11. A multilevel finite element method for Fredholm integral eigenvalue problems

    NASA Astrophysics Data System (ADS)

    Xie, Hehu; Zhou, Tao

    2015-12-01

    In this work, we proposed a multigrid finite element (MFE) method for solving the Fredholm integral eigenvalue problems. The main motivation for such studies is to compute the Karhunen-Loève expansions of random fields, which play an important role in the applications of uncertainty quantification. In our MFE framework, solving the eigenvalue problem is converted to doing a series of integral iterations and eigenvalue solving in the coarsest mesh. Then, any existing efficient integration scheme can be used for the associated integration process. The error estimates are provided, and the computational complexity is analyzed. It is noticed that the total computational work of our method is comparable with a single integration step in the finest mesh. Several numerical experiments are presented to validate the efficiency of the proposed numerical method.

  12. Direct Integration of Dynamic Emissive Displays into Knitted Fabric Structures

    NASA Astrophysics Data System (ADS)

    Bellingham, Alyssa

    electroluminescence that occur where the conductive fibers contact the EL fibers. A passive matrix addressing scheme was used to apply a voltage to each pixel individually, creating a display capable of dynamically communicating information. Optical measurements of the intensity and color of emitted light were used to quantify the performance of the display and compare it to state-of-the-art display technologies. The charge-voltage (Q-V) electrical characterization technique is used to gain information about the ACPEL fiber device operation, and mechanical tests were performed to determine the effect everyday wear and tear would have on the performance of the display. The presented textile display structure and method of producing fibers with individual sections of electroluminescence addresses the shortcomings in existing textile display technology and provides a route to directly integrated communicative textiles for applications ranging from biomedical research and monitoring to fashion. An extensive discussion of the materials and methods of production needed to scale this textile display technology and incorporate it into wearable applications is presented.

  13. [Development method of healthcare information system integration based on business collaboration model].

    PubMed

    Li, Shasha; Nie, Hongchao; Lu, Xudong; Duan, Huilong

    2015-02-01

    Integration of heterogeneous systems is the key to hospital information construction due to complexity of the healthcare environment. Currently, during the process of healthcare information system integration, people participating in integration project usually communicate by free-format document, which impairs the efficiency and adaptability of integration. A method utilizing business process model and notation (BPMN) to model integration requirement and automatically transforming it to executable integration configuration was proposed in this paper. Based on the method, a tool was developed to model integration requirement and transform it to integration configuration. In addition, an integration case in radiology scenario was used to verify the method.

  14. Integration of Directional Antennas in an RSS Fingerprinting-Based Indoor Localization System

    PubMed Central

    Guzmán-Quirós, Raúl; Martínez-Sala, Alejandro; Gómez-Tornero, José Luis; García-Haro, Joan

    2015-01-01

    In this paper, the integration of directional antennas in a room-level received signal strength (RSS) fingerprinting-based indoor localization system (ILS) is studied. The sensor reader (SR), which is in charge of capturing the RSS to infer the tag position, can be attached to an omnidirectional or directional antenna. Unlike commonly-employed omnidirectional antennas, directional antennas can receive a stronger signal from the direction in which they are pointed, resulting in a different RSS distributions in space and, hence, more distinguishable fingerprints. A simulation tool and a system management software have been also developed to control the system and assist the initial antenna deployment, reducing time-consuming costs. A prototype was mounted in a real scenario, with a number of SRs with omnidirectional and directional antennas properly positioned. Different antenna configurations have been studied, evidencing a promising capability of directional antennas to enhance the performance of RSS fingerprinting-based ILS, reducing the number of required SRs and also increasing the localization success. PMID:26703620

  15. Optical caries diagnostics: comparison of laser spectroscopic PNC method with method of laser integral fluorescence

    NASA Astrophysics Data System (ADS)

    Masychev, Victor I.

    2000-11-01

    In this research we present the results of approbation of two methods of optical caries diagnostics: PNC-spectral diagnostics and caries detection by laser integral fluorescence. The research was conducted in a dental clinic. PNC-method analyses parameters of probing laser radiation and PNC-spectrums of stimulated secondary radiations: backscattering and endogenous fluorescence of caries-involved bacterias. He-Ne-laser ((lambda) =632,8 nm, 1-2mW) was used as a source of probing (stimulated) radiation. For registration of signals, received from intact and pathological teeth PDA-detector was applied. PNC-spectrums were processed by special algorithms, and were displayed on PC monitor. The method of laser integral fluorescence was used for comparison. In this case integral power of fluorescence of human teeth was measured. As a source of probing (stimulated) radiation diode lasers ((lambda) =655 nm, 0.1 mW and 630nm, 1mW) and He-Ne laser were applied. For registration of signals Si-photodetector was used. Integral power was shown in a digital indicator. Advantages and disadvantages of these methods are described in this research. It is disclosed that the method of laser integral power of fluorescence has the following characteristics: simplicity of construction and schema-technical decisions. However the method of PNC-spectral diagnostics are characterized by considerably more sensitivity in diagnostics of initial caries and capability to differentiate pathologies of various stages (for example, calculus/initial caries). Estimation of spectral characteristics of PNC-signals allows eliminating a number of drawbacks, which are character for detection by method of laser integral fluorescence (for instance, detection of fluorescent fillings, plagues, calculus, discolorations generally, amalgam, gold fillings as if it were caries.

  16. Determination of elementary first integrals of a generalized Raychaudhuri equation by the Darboux integrability method

    NASA Astrophysics Data System (ADS)

    Choudhury, A. Ghose; Guha, Partha; Khanra, Barun

    2009-10-01

    The Darboux integrability method is particularly useful to determine first integrals of nonplanar autonomous systems of ordinary differential equations, whose associated vector fields are polynomials. In particular, we obtain first integrals for a variant of the generalized Raychaudhuri equation, which has appeared in string inspired modern cosmology.

  17. Item-method directed forgetting: Effects at retrieval?

    PubMed

    Taylor, Tracy L; Cutmore, Laura; Pries, Lotta

    2018-02-01

    In an item-method directed forgetting paradigm, words are presented one at a time, each followed by an instruction to Remember or Forget; a directed forgetting effect is measured as better subsequent memory for Remember words than Forget words. The dominant view is that the directed forgetting effect arises during encoding due to selective rehearsal of Remember over Forget items. In three experiments we attempted to falsify a strong view that directed forgetting effects in recognition are due only to encoding mechanisms when an item method is used. Across 3 experiments we tested for retrieval-based processes by colour-coding the recognition test items. Black colour provided no information; green colour cued a potential Remember item; and, red colour cued a potential Forget item. Recognition cues were mixed within-blocks in Experiment 1 and between-blocks in Experiments 2 and 3; Experiment 3 added explicit feedback on the accuracy of the recognition decision. Although overall recognition improved with cuing when explicit test performance feedback was added in Experiment 3, in no case was the magnitude of the directed forgetting effect influenced by recognition cueing. Our results argue against a role for retrieval-based strategies that limit recognition of Forget items at test and posit a role for encoding intentions only. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Depth extraction method with high accuracy in integral imaging based on moving array lenslet technique

    NASA Astrophysics Data System (ADS)

    Wang, Yao-yao; Zhang, Juan; Zhao, Xue-wei; Song, Li-pei; Zhang, Bo; Zhao, Xing

    2018-03-01

    In order to improve depth extraction accuracy, a method using moving array lenslet technique (MALT) in pickup stage is proposed, which can decrease the depth interval caused by pixelation. In this method, the lenslet array is moved along the horizontal and vertical directions simultaneously for N times in a pitch to get N sets of elemental images. Computational integral imaging reconstruction method for MALT is taken to obtain the slice images of the 3D scene, and the sum modulus (SMD) blur metric is taken on these slice images to achieve the depth information of the 3D scene. Simulation and optical experiments are carried out to verify the feasibility of this method.

  19. An efficient direct method for image registration of flat objects

    NASA Astrophysics Data System (ADS)

    Nikolaev, Dmitry; Tihonkih, Dmitrii; Makovetskii, Artyom; Voronin, Sergei

    2017-09-01

    Image alignment of rigid surfaces is a rapidly developing area of research and has many practical applications. Alignment methods can be roughly divided into two types: feature-based methods and direct methods. Known SURF and SIFT algorithms are examples of the feature-based methods. Direct methods refer to those that exploit the pixel intensities without resorting to image features and image-based deformations are general direct method to align images of deformable objects in 3D space. Nevertheless, it is not good for the registration of images of 3D rigid objects since the underlying structure cannot be directly evaluated. In the article, we propose a model that is suitable for image alignment of rigid flat objects under various illumination models. The brightness consistency assumptions used for reconstruction of optimal geometrical transformation. Computer simulation results are provided to illustrate the performance of the proposed algorithm for computing of an accordance between pixels of two images.

  20. A hybrid data fusion method for GNSS/INS integration navigation system

    NASA Astrophysics Data System (ADS)

    Yang, Ling; Li, Bofeng; Shen, Yunzhong; Li, Haojun

    2017-04-01

    Although DGNSS is widely used and PPP-GNSS is nowadays a viable precise positioning technology option, the major disadvantage of GNSS still remains: signal blockage due to obstructions in urban and built up environments, and extreme power attenuation of the signals when operated indoors. The combination of GNSS with other sensors, such as a self-contained inertial navigation system (INS), provides an ideal position and attitude determination solution which can not only mitigate the weakness of GNSS, but also bound the INS error that otherwise would grow with time when the INS operates alone. However, the navigation accuracy provided by GNSS/INS strongly depends on the quality and geometry of the GNSS observations, the quality of the INS technology used, and the integration model applied. There are two main types of coupled schemes for integration systems: loosely coupled integration and tightly coupled integration. In loosely coupled integration, position measurements are taken from both systems and combined optimally, usually in a Kalman filter. Tightly coupled integration directly combines the raw pseudorange or carrier phase measurements of GNSS with inertial measurements in an extended Kalman filter. The latter technique improves the ability to resolve ambiguities, i.e. allows a quicker recovery from outage events such as a loss of signal under vegetation. In recent years, tightly coupled differential carrier phase GNSS/INS integration has become popular, because it has the advantage of providing accurate position information even when GPS measurements are rank-deficient in stand-alone processing and is theoretically optimal in a filtering sense, especially in urban navigation applications. However, the heavier computational burden and sensor communication usually complicate the tightly coupled integration and reduce the system efficiency, compared with the loosely coupled integration. In this paper, it has been proved that the loosely coupled and tightly

  1. Methods for direct alkene diamination, new & old

    PubMed Central

    de Jong, Sam; Nosal, Daniel G.; Wardrop, Duncan J.

    2012-01-01

    The 1,2-diamine moiety is a ubiquitous structural motif present in a wealth of natural products, including non-proteinogenic amino acids and numerous alkaloids, as well as in pharmaceutical agents, chiral ligands and organic reagents. The biological activity associated with many of these systems and their chemical utility in general has ensured that the development of methods for their preparation is of critical importance. While a wide range of strategies for the preparation of 1,2-diamines have been established, the diamination of alkenes offers a particularly direct and efficient means of accessing these systems. The purpose of this review is to provide an overview of all methods of direct alkene diamination, metal-mediated or otherwise. PMID:22888177

  2. An overview of data integration methods for regional assessment.

    PubMed

    Locantore, Nicholas W; Tran, Liem T; O'Neill, Robert V; McKinnis, Peter W; Smith, Elizabeth R; O'Connell, Michael

    2004-06-01

    The U.S. Environmental Protections Agency's (U.S. EPA) Regional Vulnerability Assessment(ReVA) program has focused much of its research over the last five years on developing and evaluating integration methods for spatial data. An initial strategic priority was to use existing data from monitoring programs, model results, and other spatial data. Because most of these data were not collected with an intention of integrating into a regional assessment of conditions and vulnerabilities, issues exist that may preclude the use of some methods or require some sort of data preparation. Additionally, to support multi-criteria decision-making, methods need to be able to address a series of assessment questions that provide insights into where environmental risks are a priority. This paper provides an overview of twelve spatial integration methods that can be applied towards regional assessment, along with preliminary results as to how sensitive each method is to data issues that will likely be encountered with the use of existing data.

  3. A dynamic integrated fault diagnosis method for power transformers.

    PubMed

    Gao, Wensheng; Bai, Cuifen; Liu, Tong

    2015-01-01

    In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified.

  4. A Dynamic Integrated Fault Diagnosis Method for Power Transformers

    PubMed Central

    Gao, Wensheng; Liu, Tong

    2015-01-01

    In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified. PMID:25685841

  5. An automated integration-free path-integral method based on Kleinert's variational perturbation theory

    NASA Astrophysics Data System (ADS)

    Wong, Kin-Yiu; Gao, Jiali

    2007-12-01

    Based on Kleinert's variational perturbation (KP) theory [Path Integrals in Quantum Mechanics, Statistics, Polymer Physics, and Financial Markets, 3rd ed. (World Scientific, Singapore, 2004)], we present an analytic path-integral approach for computing the effective centroid potential. The approach enables the KP theory to be applied to any realistic systems beyond the first-order perturbation (i.e., the original Feynman-Kleinert [Phys. Rev. A 34, 5080 (1986)] variational method). Accurate values are obtained for several systems in which exact quantum results are known. Furthermore, the computed kinetic isotope effects for a series of proton transfer reactions, in which the potential energy surfaces are evaluated by density-functional theory, are in good accordance with experiments. We hope that our method could be used by non-path-integral experts or experimentalists as a "black box" for any given system.

  6. Retroviral DNA Integration Directed by HIV Integration Protein in Vitro

    NASA Astrophysics Data System (ADS)

    Bushman, Frederic D.; Fujiwara, Tamio; Craigie, Robert

    1990-09-01

    Efficient retroviral growth requires integration of a DNA copy of the viral RNA genome into a chromosome of the host. As a first step in analyzing the mechanism of integration of human immunodeficiency virus (HIV) DNA, a cell-free system was established that models the integration reaction. The in vitro system depends on the HIV integration (IN) protein, which was partially purified from insect cells engineered to express IN protein in large quantities. Integration was detected in a biological assay that scores the insertion of a linear DNA containing HIV terminal sequences into a λ DNA target. Some integration products generated in this assay contained five-base pair duplications of the target DNA at the recombination junctions, a characteristic of HIV integration in vivo; the remaining products contained aberrant junctional sequences that may have been produced in a variation of the normal reaction. These results indicate that HIV IN protein is the only viral protein required to insert model HIV DNA sequences into a target DNA in vitro.

  7. Cultural adaptation and translation of measures: an integrated method.

    PubMed

    Sidani, Souraya; Guruge, Sepali; Miranda, Joyal; Ford-Gilboe, Marilyn; Varcoe, Colleen

    2010-04-01

    Differences in the conceptualization and operationalization of health-related concepts may exist across cultures. Such differences underscore the importance of examining conceptual equivalence when adapting and translating instruments. In this article, we describe an integrated method for exploring conceptual equivalence within the process of adapting and translating measures. The integrated method involves five phases including selection of instruments for cultural adaptation and translation; assessment of conceptual equivalence, leading to the generation of a set of items deemed to be culturally and linguistically appropriate to assess the concept of interest in the target community; forward translation; back translation (optional); and pre-testing of the set of items. Strengths and limitations of the proposed integrated method are discussed. (c) 2010 Wiley Periodicals, Inc.

  8. The Boundary Integral Equation Method for Porous Media Flow

    NASA Astrophysics Data System (ADS)

    Anderson, Mary P.

    Just as groundwater hydrologists are breathing sighs of relief after the exertions of learning the finite element method, a new technique has reared its nodes—the boundary integral equation method (BIEM) or the boundary equation method (BEM), as it is sometimes called. As Liggett and Liu put it in the preface to The Boundary Integral Equation Method for Porous Media Flow, “Lately, the Boundary Integral Equation Method (BIEM) has emerged as a contender in the computation Derby.” In fact, in July 1984, the 6th International Conference on Boundary Element Methods in Engineering will be held aboard the Queen Elizabeth II, en route from Southampton to New York. These conferences are sponsored by the Department of Civil Engineering at Southampton College (UK), whose members are proponents of BIEM. The conferences have featured papers on applications of BIEM to all aspects of engineering, including flow through porous media. Published proceedings are available, as are textbooks on application of BIEM to engineering problems. There is even a 10-minute film on the subject.

  9. Integral equation methods for computing likelihoods and their derivatives in the stochastic integrate-and-fire model.

    PubMed

    Paninski, Liam; Haith, Adrian; Szirtes, Gabor

    2008-02-01

    We recently introduced likelihood-based methods for fitting stochastic integrate-and-fire models to spike train data. The key component of this method involves the likelihood that the model will emit a spike at a given time t. Computing this likelihood is equivalent to computing a Markov first passage time density (the probability that the model voltage crosses threshold for the first time at time t). Here we detail an improved method for computing this likelihood, based on solving a certain integral equation. This integral equation method has several advantages over the techniques discussed in our previous work: in particular, the new method has fewer free parameters and is easily differentiable (for gradient computations). The new method is also easily adaptable for the case in which the model conductance, not just the input current, is time-varying. Finally, we describe how to incorporate large deviations approximations to very small likelihoods.

  10. Evaluation of direct-exchange areas for a cylindrical enclosure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sika, J.

    1991-11-01

    This paper reports on a method for calculating the radiative heat transfer direct-exchange areas for surface-to-surface, volume-to-surface, and volume-to-volume pairs of zones in axisymmetric cylindrical geometries. With this method the calculation of the direct-exchange areas can be transformed from the original four-, five-, and sixfold integrals in the defining relations to just single and/or double integrals. Gray gas with absorption coefficient K is assumed.

  11. Improved accuracy for finite element structural analysis via an integrated force method

    NASA Technical Reports Server (NTRS)

    Patnaik, S. N.; Hopkins, D. A.; Aiello, R. A.; Berke, L.

    1992-01-01

    A comparative study was carried out to determine the accuracy of finite element analyses based on the stiffness method, a mixed method, and the new integrated force and dual integrated force methods. The numerical results were obtained with the following software: MSC/NASTRAN and ASKA for the stiffness method; an MHOST implementation method for the mixed method; and GIFT for the integrated force methods. The results indicate that on an overall basis, the stiffness and mixed methods present some limitations. The stiffness method generally requires a large number of elements in the model to achieve acceptable accuracy. The MHOST method tends to achieve a higher degree of accuracy for course models than does the stiffness method implemented by MSC/NASTRAN and ASKA. The two integrated force methods, which bestow simultaneous emphasis on stress equilibrium and strain compatibility, yield accurate solutions with fewer elements in a model. The full potential of these new integrated force methods remains largely unexploited, and they hold the promise of spawning new finite element structural analysis tools.

  12. An integrated lean-methods approach to hospital facilities redesign.

    PubMed

    Nicholas, John

    2012-01-01

    Lean production methods for eliminating waste and improving processes in manufacturing are now being applied in healthcare. As the author shows, the methods are appropriate for redesigning hospital facilities. When used in an integrated manner and employing teams of mostly clinicians, the methods produce facility designs that are custom-fit to patient needs and caregiver work processes, and reduce operational costs. The author reviews lean methods and an approach for integrating them in the redesign of hospital facilities. A case example of the redesign of an emergency department shows the feasibility and benefits of the approach.

  13. The Direct Method of Cash Flows.

    ERIC Educational Resources Information Center

    Bosserman, David C.; Fischer, Mary

    2000-01-01

    Explains to college/university business officers how to comply with Governmental Accounting Standards Board Statements Nos. 34, 35, and 9, which require the direct method of presenting cash flows from operating activities and reconciliation of operating cash flows to operating income by fiscal year 2001. Institutions are urged to begin immediately…

  14. Integrated assessment of the direct and indirect effects of resource gradients on tree species recruitment.

    PubMed

    Ibáñez, Inés; McCarthy-Neumann, Sarah

    2014-02-01

    Understanding the dynamics of tree establishment is critical to assess forests' composition, management practices, and current responses to global change. We carried out a field seedling transplant experiment to assess not only the direct effects of resources influencing recruitment of four tree species, but also their indirect and combined effects. Our analysis integrated first growing season demographic data together with estimates of mycorrhizal fungal colonization and resource availability (light, soil moisture, and soil nitrogen). Only by considering both the direct and indirect effects of resources we were able to account for most of the variability observed during seedling recruitment. Contrary to expectations, increasing light levels were not always beneficial for recruitment even in low light habitats, and soil moisture availability benefited seedling growth but not survival. In addition, mycorrhizal fungal colonization was not always favored by high light levels or by increasing soil moisture. Seedling survival for all species was lower in plots with higher arbuscular mycorrhizal fungi, while the association with ectomycorrhizal fungi varied from beneficial to detrimental. When integrating the direct, indirect, and interactive effects of resource availability and mycorrhizal fungal colonization on tree recruitment dynamics we found that species responded in a nonlinear fashion to increasing resource levels, and we also identified thresholds, i.e., shifts in the direction of the response, along the resource gradient. Our integrated assessment considerably outperformed a null model where only direct effects of resources were accounted for. These results illustrate how the combination of direct, indirect, and combined effects of driving variables better represents the complexity of the processes determining tree species recruitment than simple resource availability mechanisms.

  15. A Direct and Non-Singular UKF Approach Using Euler Angle Kinematics for Integrated Navigation Systems

    PubMed Central

    Ran, Changyan; Cheng, Xianghong

    2016-01-01

    This paper presents a direct and non-singular approach based on an unscented Kalman filter (UKF) for the integration of strapdown inertial navigation systems (SINSs) with the aid of velocity. The state vector includes velocity and Euler angles, and the system model contains Euler angle kinematics equations. The measured velocity in the body frame is used as the filter measurement. The quaternion nonlinear equality constraint is eliminated, and the cross-noise problem is overcome. The filter model is simple and easy to apply without linearization. Data fusion is performed by an UKF, which directly estimates and outputs the navigation information. There is no need to process navigation computation and error correction separately because the navigation computation is completed synchronously during the filter time updating. In addition, the singularities are avoided with the help of the dual-Euler method. The performance of the proposed approach is verified by road test data from a land vehicle equipped with an odometer aided SINS, and a singularity turntable test is conducted using three-axis turntable test data. The results show that the proposed approach can achieve higher navigation accuracy than the commonly-used indirect approach, and the singularities can be efficiently removed as the result of dual-Euler method. PMID:27598169

  16. Analysis of crack propagation in roller bearings using the boundary integral equation method - A mixed-mode loading problem

    NASA Technical Reports Server (NTRS)

    Ghosn, L. J.

    1988-01-01

    Crack propagation in a rotating inner raceway of a high-speed roller bearing is analyzed using the boundary integral method. The model consists of an edge plate under plane strain condition upon which varying Hertzian stress fields are superimposed. A multidomain boundary integral equation using quadratic elements was written to determine the stress intensity factors KI and KII at the crack tip for various roller positions. The multidomain formulation allows the two faces of the crack to be modeled in two different subregions, making it possible to analyze crack closure when the roller is positioned on or close to the crack line. KI and KII stress intensity factors along any direction were computed. These calculations permit determination of crack growth direction along which the average KI times the alternating KI is maximum.

  17. Fully Integrated Microfluidic Device for Direct Sample-to-Answer Genetic Analysis

    NASA Astrophysics Data System (ADS)

    Liu, Robin H.; Grodzinski, Piotr

    Integration of microfluidics technology with DNA microarrays enables building complete sample-to-answer systems that are useful in many applications such as clinic diagnostics. In this chapter, a fully integrated microfluidic device [1] that consists of microfluidic mixers, valves, pumps, channels, chambers, heaters, and a DNA microarray sensor to perform DNA analysis of complex biological sample solutions is present. This device can perform on-chip sample preparation (including magnetic bead-based cell capture, cell preconcentration and purification, and cell lysis) of complex biological sample solutions (such as whole blood), polymerase chain reaction, DNA hybridization, and electrochemical detection. A few novel microfluidic techniques were developed and employed. A micromix-ing technique based on a cavitation microstreaming principle was implemented to enhance target cell capture from whole blood samples using immunomagnetic beads. This technique was also employed to accelerate DNA hybridization reaction. Thermally actuated paraffin-based microvalves were developed to regulate flows. Electrochemical pumps and thermopneumatic pumps were integrated on the chip to provide pumping of liquid solutions. The device is completely self-contained: no external pressure sources, fluid storage, mechanical pumps, or valves are necessary for fluid manipulation, thus eliminating possible sample contamination and simplifying device operation. Pathogenic bacteria detection from ~mL whole blood samples and single-nucleotide polymorphism analysis directly from diluted blood were demonstrated. The device provides a cost-effective solution to direct sample-to-answer genetic analysis, and thus has a potential impact in the fields of point-of-care genetic analysis, environmental testing, and biological warfare agent detection.

  18. Integrative methods for analyzing big data in precision medicine.

    PubMed

    Gligorijević, Vladimir; Malod-Dognin, Noël; Pržulj, Nataša

    2016-03-01

    We provide an overview of recent developments in big data analyses in the context of precision medicine and health informatics. With the advance in technologies capturing molecular and medical data, we entered the area of "Big Data" in biology and medicine. These data offer many opportunities to advance precision medicine. We outline key challenges in precision medicine and present recent advances in data integration-based methods to uncover personalized information from big data produced by various omics studies. We survey recent integrative methods for disease subtyping, biomarkers discovery, and drug repurposing, and list the tools that are available to domain scientists. Given the ever-growing nature of these big data, we highlight key issues that big data integration methods will face. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Determining a Method of Enabling and Disabling the Integral Torque in the SDO Science and Inertial Mode Controllers

    NASA Technical Reports Server (NTRS)

    Vess, Melissa F.; Starin, Scott R.

    2007-01-01

    During design of the SDO Science and Inertial mode PID controllers, the decision was made to disable the integral torque whenever system stability was in question. Three different schemes were developed to determine when to disable or enable the integral torque, and a trade study was performed to determine which scheme to implement. The trade study compared complexity of the control logic, risk of not reenabling the integral gain in time to reject steady-state error, and the amount of integral torque space used. The first scheme calculated a simplified Routh criterion to determine when to disable the integral torque. The second scheme calculates the PD part of the torque and looked to see if that torque would cause actuator saturation. If so, only the PD torque is used. If not, the integral torque is added. Finally, the third scheme compares the attitude and rate errors to limits and disables the integral torque if either of the errors is greater than the limit. Based on the trade study results, the third scheme was selected. Once it was decided when to disable the integral torque, analysis was performed to determine how to disable the integral torque and whether or not to reset the integrator once the integral torque was reenabled. Three ways to disable the integral torque were investigated: zero the input into the integrator, which causes the integral part of the PID control torque to be held constant; zero the integral torque directly but allow the integrator to continue integrating; or zero the integral torque directly and reset the integrator on integral torque reactivation. The analysis looked at complexity of the control logic, slew time plus settling time between each calibration maneuver step, and ability to reject steady-state error. Based on the results of the analysis, the decision was made to zero the input into the integrator without resetting it. Throughout the analysis, a high fidelity simulation was used to test the various implementation methods.

  20. Differential temperature integrating diagnostic method and apparatus

    DOEpatents

    Doss, James D.; McCabe, Charles W.

    1976-01-01

    A method and device for detecting the presence of breast cancer in women by integrating the temperature difference between the temperature of a normal breast and that of a breast having a malignant tumor. The breast-receiving cups of a brassiere are each provided with thermally conductive material next to the skin, with a thermistor attached to the thermally conductive material in each cup. The thermistors are connected to adjacent arms of a Wheatstone bridge. Unbalance currents in the bridge are integrated with respect to time by means of an electrochemical integrator. In the absence of a tumor, both breasts maintain substantially the same temperature, and the bridge remains balanced. If the tumor is present in one breast, a higher temperature in that breast unbalances the bridge and the electrochemical cells integrate the temperature difference with respect to time.

  1. Direct methods in protein crystallography.

    PubMed

    Karle, J

    1989-11-01

    It is pointed out that the 'direct methods' of phase determination for small-structure crystallography do not have immediate applicability to macromolecular structures. The term 'direct methods in macromolecular crystallography' is suggested to categorize a spectrum of approaches to macromolecular structure determination in which the analyses are characterized by the use of two-phase and higher-order-phase invariants. The evaluation of the invariants is generally obtained by the use of heavy-atom techniques. The results of a number of the more recent algebraic and probabilistic studies involving isomorphous replacement and anomalous dispersion thus become valid subjects for discussion here. These studies are described and suggestions are also presented concerning future applicability. Additional discussion concerns the special techniques of filtering, the use of non-crystallographic symmetry, some features of maximum entropy and attempts to apply phase-determining formulas to the refinement of macromolecular structure. It is noted that, in addition to the continuing remarkable progress in macromolecular crystallography based on the traditional applications of isomorphous replacement and anomalous dispersion, recent valuable advances have been made in the application of non-crystallographic symmetry, in particular, to virus structures and in applications of filtering. Good progress has also been reported in the application of exact linear algebra to multiple-wavelength anomalous-dispersion investigations of structures containing anomalous scatterers of only moderate scattering power.

  2. Verification of E-Beam direct write integration into 28nm BEOL SRAM technology

    NASA Astrophysics Data System (ADS)

    Hohle, Christoph; Choi, Kang-Hoon; Gutsch, Manuela; Hanisch, Norbert; Seidel, Robert; Steidel, Katja; Thrun, Xaver; Werner, Thomas

    2015-03-01

    Electron beam direct write lithography (EBDW) potentially offers advantages for low-volume semiconductor manufacturing, rapid prototyping or design verification due to its high flexibility without the need of costly masks. However, the integration of this advanced patterning technology into complex CMOS manufacturing processes remains challenging. The low throughput of today's single e-Beam tools limits high volume manufacturing applications and maturity of parallel (multi) beam systems is still insufficient [1,2]. Additional concerns like transistor or material damage of underlying layers during exposure at high electron density or acceleration voltage have to be addressed for advanced technology nodes. In the past we successfully proved that potential degradation effects of high-k materials or ULK shrink can be neglected and were excluded by demonstrating integrated electrical results of 28nm node transistor and BEOL performance following 50kV electron beam dry exposure [3]. Here we will give an update on the integration of EBDW in the 300mm CMOS manufacturing processes of advanced integrated circuits at the 28nm SRAM node of GLOBALFOUNDRIES Dresden. The work is an update to what has been previously published [4]. E-beam patterning results of BEOL full chip metal and via layers with a dual damascene integration scheme using a 50kV VISTEC SB3050DW variable shaped electron beam direct writer at Fraunhofer IPMSCNT are demonstrated. For the patterning of the Metal layer a Mix & Match concept based on the sequence litho - etch -litho -etch (LELE) was developed and evaluated wherein several exposure fields were blanked out during the optical exposure. Etch results are shown and compared to the POR. Results are also shown on overlay performance and optimized e-Beam exposure time using most advanced data prep solutions and resist processes. The patterning results have been verified using fully integrated electrical measurement of metal lines and vias on wafer level. In

  3. Direct SQP-methods for solving optimal control problems with delays

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goellmann, L.; Bueskens, C.; Maurer, H.

    The maximum principle for optimal control problems with delays leads to a boundary value problem (BVP) which is retarded in the state and advanced in the costate function. Based on shooting techniques, solution methods for this type of BVP have been proposed. In recent years, direct optimization methods have been favored for solving control problems without delays. Direct methods approximate the control and the state over a fixed mesh and solve the resulting NLP-problem with SQP-methods. These methods dispense with the costate function and have shown to be robust and efficient. In this paper, we propose a direct SQP-method formore » retarded control problems. In contrast to conventional direct methods, only the control variable is approximated by e.g. spline-functions. The state is computed via a high order Runge-Kutta type algorithm and does not enter explicitly the NLP-problem through an equation. This approach reduces the number of optimization variables considerably and is implementable even on a PC. Our method is illustrated by the numerical solution of retarded control problems with constraints. In particular, we consider the control of a continuous stirred tank reactor which has been solved by dynamic programming. This example illustrates the robustness and efficiency of the proposed method. Open questions concerning sufficient conditions and convergence of discretized NLP-problems are discussed.« less

  4. Variational method for integrating radial gradient field

    NASA Astrophysics Data System (ADS)

    Legarda-Saenz, Ricardo; Brito-Loeza, Carlos; Rivera, Mariano; Espinosa-Romero, Arturo

    2014-12-01

    We propose a variational method for integrating information obtained from circular fringe pattern. The proposed method is a suitable choice for objects with radial symmetry. First, we analyze the information contained in the fringe pattern captured by the experimental setup and then move to formulate the problem of recovering the wavefront using techniques from calculus of variations. The performance of the method is demonstrated by numerical experiments with both synthetic and real data.

  5. Critical perspectives of pedagogical approaches to reversing the order of integration in double integrals

    NASA Astrophysics Data System (ADS)

    Tisdell, Christopher C.

    2017-11-01

    This paper presents some critical perspectives regarding pedagogical approaches to the method of reversing the order of integration in double integrals from prevailing educational literature on multivariable calculus. First, we question the message found in popular textbooks that the traditional process of reversing the order of integration is necessary when solving well-known problems. Second, we illustrate that the method of integration by parts can be directly applied to many of the classic pedagogical problems in the literature concerning double integrals, without taking the well-worn steps associated with reversing the order of integration. Third, we examine the benefits and limitations of such a method. In our conclusion, we advocate for integration by parts to be a part of the pedagogical conversation in the learning and teaching of double integral methods; and call for more debate around its use in the learning and teaching of other areas of mathematics. Finally, we emphasize the need for critical approaches in the pedagogy of mathematics more broadly.

  6. A boundary integral equation method using auxiliary interior surface approach for acoustic radiation and scattering in two dimensions.

    PubMed

    Yang, S A

    2002-10-01

    This paper presents an effective solution method for predicting acoustic radiation and scattering fields in two dimensions. The difficulty of the fictitious characteristic frequency is overcome by incorporating an auxiliary interior surface that satisfies certain boundary condition into the body surface. This process gives rise to a set of uniquely solvable boundary integral equations. Distributing monopoles with unknown strengths over the body and interior surfaces yields the simple source formulation. The modified boundary integral equations are further transformed to ordinary ones that contain nonsingular kernels only. This implementation allows direct application of standard quadrature formulas over the entire integration domain; that is, the collocation points are exactly the positions at which the integration points are located. Selecting the interior surface is an easy task. Moreover, only a few corresponding interior nodal points are sufficient for the computation. Numerical calculations consist of the acoustic radiation and scattering by acoustically hard elliptic and rectangular cylinders. Comparisons with analytical solutions are made. Numerical results demonstrate the efficiency and accuracy of the current solution method.

  7. Stem Cell Monitoring with a Direct or Indirect Labeling Method.

    PubMed

    Kim, Min Hwan; Lee, Yong Jin; Kang, Joo Hyun

    2016-12-01

    The molecular imaging techniques allow monitoring of the transplanted cells in the same individuals over time, from early localization to the survival, migration, and differentiation. Generally, there are two methods of stem cell labeling: direct and indirect labeling methods. The direct labeling method introduces a labeling agent into the cell, which is stably incorporated or attached to the cells prior to transplantation. Direct labeling of cells with radionuclides is a simple method with relatively fewer adverse events related to genetic responses. However, it can only allow short-term distribution of transplanted cells because of the decreasing imaging signal with radiodecay, according to the physical half-lives, or the signal becomes more diffuse with cell division and dispersion. The indirect labeling method is based on the expression of a reporter gene transduced into the cell before transplantation, which is then visualized upon the injection of an appropriate probe or substrate. In this review, various imaging strategies to monitor the survival and behavior change of transplanted stem cells are covered. Taking these new approaches together, the direct and indirect labeling methods may provide new insights on the roles of in vivo stem cell monitoring, from bench to bedside.

  8. Direct matching methods for coils and preamplifiers in MRI

    NASA Astrophysics Data System (ADS)

    Cao, Xueming; Fischer, Elmar; Hennig, Jürgen; Zaitsev, Maxim

    2018-05-01

    In this paper, direct matching methods for coils and preamplifiers in receiver arrays are presented. Instead of compensating the reactance of the input impedance of preamplifiers, in our method, the reactance was used to resonate with the coil matching networks and thus to decouple the coils. Furthermore, coil matching networks and preamplifier input matching networks were combined, meaning the coil loop can be matched to the transistor in the preamplifier directly. These matching methods and, for comparison, the conventional matching method were implemented with custom-made preamplifiers and coils. Decoupling and noise-matching performance were compared between these three configurations. Phase shifting networks between coils and preamplifiers are not necessary in our matching methods. With fewer components, these matching networks showed lower noise factors, while similar preamplifier-decoupling performance was found for all three methods.

  9. A fully integrated direct-conversion digital satellite tuner in 0.18 μm CMOS

    NASA Astrophysics Data System (ADS)

    Si, Chen; Zengwang, Yang; Mingliang, Gu

    2011-04-01

    A fully integrated direct-conversion digital satellite tuner for DVB-S/S2 and ABS-S applications is presented. A broadband noise-canceling Balun-LNA and passive quadrature mixers provided a high-linearity low noise RF front-end, while the synthesizer integrated the loop filter to reduce the solution cost and system debug time. Fabricated in 0.18 μm CMOS, the chip achieves a less than 7.6 dB noise figure over a 900-2150 MHz L-band, while the measured sensitivity for 4.42 MS/s QPSK-3/4 mode is -91 dBm at the PCB connector. The fully integrated integer-N synthesizer operating from 2150 to 4350 MHz achieves less than 1 °C integrated phase error. The chip consumes about 145 mA at a 3.3 V supply with internal integrated LDOs.

  10. Methods of Genomic Competency Integration in Practice

    PubMed Central

    Jenkins, Jean; Calzone, Kathleen A.; Caskey, Sarah; Culp, Stacey; Weiner, Marsha; Badzek, Laurie

    2015-01-01

    Purpose Genomics is increasingly relevant to health care, necessitating support for nurses to incorporate genomic competencies into practice. The primary aim of this project was to develop, implement, and evaluate a year-long genomic education intervention that trained, supported, and supervised institutional administrator and educator champion dyads to increase nursing capacity to integrate genomics through assessments of program satisfaction and institutional achieved outcomes. Design Longitudinal study of 23 Magnet Recognition Program® Hospitals (21 intervention, 2 controls) participating in a 1-year new competency integration effort aimed at increasing genomic nursing competency and overcoming barriers to genomics integration in practice. Methods Champion dyads underwent genomic training consisting of one in-person kick-off training meeting followed by monthly education webinars. Champion dyads designed institution-specific action plans detailing objectives, methods or strategies used to engage and educate nursing staff, timeline for implementation, and outcomes achieved. Action plans focused on a minimum of seven genomic priority areas: champion dyad personal development; practice assessment; policy content assessment; staff knowledge needs assessment; staff development; plans for integration; and anticipated obstacles and challenges. Action plans were updated quarterly, outlining progress made as well as inclusion of new methods or strategies. Progress was validated through virtual site visits with the champion dyads and chief nursing officers. Descriptive data were collected on all strategies or methods utilized, and timeline for achievement. Descriptive data were analyzed using content analysis. Findings The complexity of the competency content and the uniqueness of social systems and infrastructure resulted in a significant variation of champion dyad interventions. Conclusions Nursing champions can facilitate change in genomic nursing capacity through

  11. Integral method for transient He II heat transfer in a semi-infinite domain

    NASA Astrophysics Data System (ADS)

    Baudouy, B.

    2002-05-01

    Integral methods are suited to solve a non-linear system of differential equations where the non-linearity can be found either in the differential equations or in the boundary conditions. Though they are approximate methods, they have proven to give simple solutions with acceptable accuracy for transient heat transfer in He II. Taking in account the temperature dependence of thermal properties, direct solutions are found without the need of adjusting a parameter. Previously, we have presented a solution for the clamped heat flux and in the present study this method is used to accommodate the clamped-temperature problem. In the case of constant thermal properties, this method yields results that are within a few percent of the exact solution for the heat flux at the axis origin. We applied this solution to analyze recovery from burnout and find an agreement within 10% at low heat flux, whereas at high heat flux the model deviates from the experimental data suggesting the need for a more refined thermal model.

  12. Adaptive Monte Carlo methods

    NASA Astrophysics Data System (ADS)

    Fasnacht, Marc

    We develop adaptive Monte Carlo methods for the calculation of the free energy as a function of a parameter of interest. The methods presented are particularly well-suited for systems with complex energy landscapes, where standard sampling techniques have difficulties. The Adaptive Histogram Method uses a biasing potential derived from histograms recorded during the simulation to achieve uniform sampling in the parameter of interest. The Adaptive Integration method directly calculates an estimate of the free energy from the average derivative of the Hamiltonian with respect to the parameter of interest and uses it as a biasing potential. We compare both methods to a state of the art method, and demonstrate that they compare favorably for the calculation of potentials of mean force of dense Lennard-Jones fluids. We use the Adaptive Integration Method to calculate accurate potentials of mean force for different types of simple particles in a Lennard-Jones fluid. Our approach allows us to separate the contributions of the solvent to the potential of mean force from the effect of the direct interaction between the particles. With contributions of the solvent determined, we can find the potential of mean force directly for any other direct interaction without additional simulations. We also test the accuracy of the Adaptive Integration Method on a thermodynamic cycle, which allows us to perform a consistency check between potentials of mean force and chemical potentials calculated using the Adaptive Integration Method. The results demonstrate a high degree of consistency of the method.

  13. Sparse Method for Direction of Arrival Estimation Using Denoised Fourth-Order Cumulants Vector.

    PubMed

    Fan, Yangyu; Wang, Jianshu; Du, Rui; Lv, Guoyun

    2018-06-04

    Fourth-order cumulants (FOCs) vector-based direction of arrival (DOA) estimation methods of non-Gaussian sources may suffer from poor performance for limited snapshots or difficulty in setting parameters. In this paper, a novel FOCs vector-based sparse DOA estimation method is proposed. Firstly, by utilizing the concept of a fourth-order difference co-array (FODCA), an advanced FOCs vector denoising or dimension reduction procedure is presented for arbitrary array geometries. Then, a novel single measurement vector (SMV) model is established by the denoised FOCs vector, and efficiently solved by an off-grid sparse Bayesian inference (OGSBI) method. The estimation errors of FOCs are integrated in the SMV model, and are approximately estimated in a simple way. A necessary condition regarding the number of identifiable sources of our method is presented that, in order to uniquely identify all sources, the number of sources K must fulfill K ≤ ( M 4 - 2 M 3 + 7 M 2 - 6 M ) / 8 . The proposed method suits any geometry, does not need prior knowledge of the number of sources, is insensitive to associated parameters, and has maximum identifiability O ( M 4 ) , where M is the number of sensors in the array. Numerical simulations illustrate the superior performance of the proposed method.

  14. A Methodology for Conducting Integrative Mixed Methods Research and Data Analyses

    PubMed Central

    Castro, Felipe González; Kellison, Joshua G.; Boyd, Stephen J.; Kopak, Albert

    2011-01-01

    Mixed methods research has gained visibility within the last few years, although limitations persist regarding the scientific caliber of certain mixed methods research designs and methods. The need exists for rigorous mixed methods designs that integrate various data analytic procedures for a seamless transfer of evidence across qualitative and quantitative modalities. Such designs can offer the strength of confirmatory results drawn from quantitative multivariate analyses, along with “deep structure” explanatory descriptions as drawn from qualitative analyses. This article presents evidence generated from over a decade of pilot research in developing an integrative mixed methods methodology. It presents a conceptual framework and methodological and data analytic procedures for conducting mixed methods research studies, and it also presents illustrative examples from the authors' ongoing integrative mixed methods research studies. PMID:22167325

  15. A new method for the evaluation of the direct effect of the ship traffic on PAHs

    NASA Astrophysics Data System (ADS)

    Gregoris, Elena; De Pieri, Silvia; Barbaro, Elena; Piazza, Rossano; Gambaro, Andrea; Contini, Daniele

    2015-04-01

    Emissions of exhaust gases and particles from ships can affect significantly the chemical composition of the atmosphere, local and regional air quality and climate. These emissions might have harmful effects on human health, since Mediterranean harbors are often located near or within the cities. Moreover ships and harbours emissions are currently increasing, due to the grow of tourism and trade, further amplifying this issue. International legislation and local agreements are mainly based on the use of low-sulphur fuel content, but also other chemicals, such as polycyclic aromatic hydrocarbons (PAHs), play an important role. Because of their low reactivity PAHs can persist in the environment for a long time; moreover they bioaccumulate, causing adverse effect on human health, such as reproductive and immune effects, developmental anomalies and cancer. This work is linked to the POSEIDON project (POllution monitoring of Ship Emission: an IntegrateD approach fOr harbor of the Adriatic basiN), that aims to quantify the atmospheric pollution generated by ship traffic and harbor activities in four port-cities of the Adriatic Sea (Brindisi, Venice, Rijeka, Patras). Here, a new method for the evaluation of the direct effect of ship traffic and harbour activities on polycyclic aromatic hydrocarbons is presented. In this method two high-volume samplers are operating: one of them collecting air from all directions; the other one is programmed to activate only when the wind is blowing from a specific sector (the harbour area). From the compared results, information about the effect of the harbour on the global PAHs concentration can be obtained. The method was applied in Venice in two summer sampling campaigns, in 2009 and 2012.

  16. A systematic and efficient method to compute multi-loop master integrals

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Ma, Yan-Qing; Wang, Chen-Yu

    2018-04-01

    We propose a novel method to compute multi-loop master integrals by constructing and numerically solving a system of ordinary differential equations, with almost trivial boundary conditions. Thus it can be systematically applied to problems with arbitrary kinematic configurations. Numerical tests show that our method can not only achieve results with high precision, but also be much faster than the only existing systematic method sector decomposition. As a by product, we find a new strategy to compute scalar one-loop integrals without reducing them to master integrals.

  17. Path-integral Monte Carlo method for Rényi entanglement entropies.

    PubMed

    Herdman, C M; Inglis, Stephen; Roy, P-N; Melko, R G; Del Maestro, A

    2014-07-01

    We introduce a quantum Monte Carlo algorithm to measure the Rényi entanglement entropies in systems of interacting bosons in the continuum. This approach is based on a path-integral ground state method that can be applied to interacting itinerant bosons in any spatial dimension with direct relevance to experimental systems of quantum fluids. We demonstrate how it may be used to compute spatial mode entanglement, particle partitioned entanglement, and the entanglement of particles, providing insights into quantum correlations generated by fluctuations, indistinguishability, and interactions. We present proof-of-principle calculations and benchmark against an exactly soluble model of interacting bosons in one spatial dimension. As this algorithm retains the fundamental polynomial scaling of quantum Monte Carlo when applied to sign-problem-free models, future applications should allow for the study of entanglement entropy in large-scale many-body systems of interacting bosons.

  18. Integrated human-earth system modeling—state of the science and future directions

    NASA Astrophysics Data System (ADS)

    Calvin, Katherine; Bond-Lamberty, Ben

    2018-06-01

    Research on humans and the Earth system has historically occurred separately, with different teams and models devoted to each. Increasingly, however, these communities and models are becoming intricately linked. In this review, we survey the literature on integrated human-Earth system models, quantify the direction and strength of feedbacks in those models, and put them in context of other, more frequently considered, feedbacks in the Earth system. We find that such feedbacks have the potential to alter both human and Earth systems; however, there is significant uncertainty in these results, and the number of truly integrated studies remains small. More research, more models, and more studies are needed to robustly quantify the sign and magnitude of human-Earth system feedbacks. Integrating human and earth models entails significant complexity and cost, and researchers should carefully assess the costs and benefits of doing so with respect to the object of study.

  19. Solving complex photocycle kinetics. Theory and direct method.

    PubMed Central

    Nagle, J F

    1991-01-01

    A direct nonlinear least squares method is described that obtains the true kinetic rate constants and the temperature-independent spectra of n intermediates from spectroscopic data taken in the visible at three or more temperatures. A theoretical analysis, which is independent of implementation of the direct method, proves that well determined local solutions are not possible for fewer than three temperatures. This analysis also proves that measurements at more than n wavelengths are redundant, although the direct method indicates that convergence is faster if n + m wavelengths are measured, where m is of order one. This suggests that measurements should concentrate on high precision for a few measuring wavelengths, rather than lower precision for many wavelengths. Globally, false solutions occur, and the ability to reject these depends upon the precision of the data, as shown by explicit example. An optimized way to analyze vibrational spectroscopic data is also presented. Such data yield unique results, which are comparably accurate to those obtained from data taken in the visible with comparable noise. It is discussed how use of both kinds of data is advantageous if the data taken in the visible are significantly less noisy. PMID:2009362

  20. A study of compositional verification based IMA integration method

    NASA Astrophysics Data System (ADS)

    Huang, Hui; Zhang, Guoquan; Xu, Wanmeng

    2018-03-01

    The rapid development of avionics systems is driving the application of integrated modular avionics (IMA) systems. But meanwhile it is improving avionics system integration, complexity of system test. Then we need simplify the method of IMA system test. The IMA system supports a module platform that runs multiple applications, and shares processing resources. Compared with federated avionics system, IMA system is difficult to isolate failure. Therefore, IMA system verification will face the critical problem is how to test shared resources of multiple application. For a simple avionics system, traditional test methods are easily realizing to test a whole system. But for a complex system, it is hard completed to totally test a huge and integrated avionics system. Then this paper provides using compositional-verification theory in IMA system test, so that reducing processes of test and improving efficiency, consequently economizing costs of IMA system integration.

  1. Application of two direct runoff prediction methods in Puerto Rico

    USGS Publications Warehouse

    Sepulveda, N.

    1997-01-01

    Two methods for predicting direct runoff from rainfall data were applied to several basins and the resulting hydrographs compared to measured values. The first method uses a geomorphology-based unit hydrograph to predict direct runoff through its convolution with the excess rainfall hyetograph. The second method shows how the resulting hydraulic routing flow equation from a kinematic wave approximation is solved using a spectral method based on the matrix representation of the spatial derivative with Chebyshev collocation and a fourth-order Runge-Kutta time discretization scheme. The calibrated Green-Ampt (GA) infiltration parameters are obtained by minimizing the sum, over several rainfall events, of absolute differences between the total excess rainfall volume computed from the GA equations and the total direct runoff volume computed from a hydrograph separation technique. The improvement made in predicting direct runoff using a geomorphology-based unit hydrograph with the ephemeral and perennial stream network instead of the strictly perennial stream network is negligible. The hydraulic routing scheme presented here is highly accurate in predicting the magnitude and time of the hydrograph peak although the much faster unit hydrograph method also yields reasonable results.

  2. Analytical methods in environmental effects-directed investigations of effluents.

    PubMed

    Hewitt, L Mark; Marvin, Chris H

    2005-05-01

    Effluent discharges are released into aquatic environments as complex mixtures for which there is commonly either no knowledge of the toxic components or a lack of understanding of how known toxicants interact with other effluent components. Effects-directed investigations consist of chemical extraction and iterative fractionation steps directed by a biological endpoint that is designed to permit the identification or characterization of the chemical classes or compounds in a complex mixture responsible for the observed biological activity. Our review of the literature on effects-directed analyses of effluents for non-mutagenic as well as mutagenic endpoints showed that common extraction and concentration methods have been used. Since the mid-1980s, the methods have evolved from the use of XAD resins to C18 solid-phase extraction (SPE). Blue cotton, blue rayon, and blue chitin have been used specifically for investigations of mutagenic activity where polycyclic compounds were involved or suspected. After isolation, subsequent fractionations have been accomplished using SPE or a high-pressure liquid chromatography (HPLC) system commonly fitted with a C18 reverse-phase column. Substances in active fractions are characterized by gas chromatography/mass spectrometry (GC-MS) and/or other spectrometric techniques for identification. LC-MS methods have been developed for difficult-to-analyze polar substances identified from effects-directed studies, but the potential for LC-MS to identify unknown polar compounds has yet to be fully realized. Salmonella-based assays (some miniaturized) have been coupled with fractionation methods for most studies aimed at identifying mutagenic fractions and chemical classes in mixtures. Effects-directed investigations of mutagens have focused mostly on drinking water and sewage, whereas extensive investigations of non-mutagenic effects have also included runoff, pesticides, and pulp mill effluents. The success of effects-directed

  3. Method of mechanical quadratures for solving singular integral equations of various types

    NASA Astrophysics Data System (ADS)

    Sahakyan, A. V.; Amirjanyan, H. A.

    2018-04-01

    The method of mechanical quadratures is proposed as a common approach intended for solving the integral equations defined on finite intervals and containing Cauchy-type singular integrals. This method can be used to solve singular integral equations of the first and second kind, equations with generalized kernel, weakly singular equations, and integro-differential equations. The quadrature rules for several different integrals represented through the same coefficients are presented. This allows one to reduce the integral equations containing integrals of different types to a system of linear algebraic equations.

  4. Improved accuracy for finite element structural analysis via a new integrated force method

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Hopkins, Dale A.; Aiello, Robert A.; Berke, Laszlo

    1992-01-01

    A comparative study was carried out to determine the accuracy of finite element analyses based on the stiffness method, a mixed method, and the new integrated force and dual integrated force methods. The numerical results were obtained with the following software: MSC/NASTRAN and ASKA for the stiffness method; an MHOST implementation method for the mixed method; and GIFT for the integrated force methods. The results indicate that on an overall basis, the stiffness and mixed methods present some limitations. The stiffness method generally requires a large number of elements in the model to achieve acceptable accuracy. The MHOST method tends to achieve a higher degree of accuracy for course models than does the stiffness method implemented by MSC/NASTRAN and ASKA. The two integrated force methods, which bestow simultaneous emphasis on stress equilibrium and strain compatibility, yield accurate solutions with fewer elements in a model. The full potential of these new integrated force methods remains largely unexploited, and they hold the promise of spawning new finite element structural analysis tools.

  5. Bioluminescent bioreporter integrated circuit detection methods

    DOEpatents

    Simpson, Michael L.; Paulus, Michael J.; Sayler, Gary S.; Applegate, Bruce M.; Ripp, Steven A.

    2005-06-14

    Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for detection of particular analytes, including ammonia and estrogen compounds.

  6. A direct viable count method for the enumeration of attached bacteria and assessment of biofilm disinfection

    NASA Technical Reports Server (NTRS)

    Yu, F. P.; Pyle, B. H.; McFeters, G. A.

    1993-01-01

    This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.

  7. Laser Direct Writing and Selective Metallization of Metallic Circuits for Integrated Wireless Devices.

    PubMed

    Cai, Jinguang; Lv, Chao; Watanabe, Akira

    2018-01-10

    Portable and wearable devices have attracted wide research attention due to their intimate relations with human daily life. As basic structures in the devices, the preparation of high-conductive metallic circuits or micro-circuits on flexible substrates should be facile, cost-effective, and easily integrated with other electronic units. In this work, high-conductive carbon/Ni composite structures were prepared by using a facile laser direct writing method, followed by an electroless Ni plating process, which exhibit a 3-order lower sheet resistance of less than 0.1 ohm/sq compared to original structures before plating, showing the potential for practical use. The carbon/Ni composite structures exhibited a certain flexibility and excellent anti-scratch property due to the tight deposition of Ni layers on carbon surfaces. On the basis of this approach, a wireless charging and storage device on a polyimide film was demonstrated by integrating an outer rectangle carbon/Ni composite coil for harvesting electromagnetic waves and an inner carbon micro-supercapacitor for energy storage, which can be fast charged wirelessly by a commercial wireless charger. Furthermore, a near-field communication (NFC) tag was prepared by combining a carbon/Ni composite coil for harvesting signals and a commercial IC chip for data storage, which can be used as an NFC tag for practical application.

  8. Towards a taxonomy for integrated care: a mixed-methods study

    PubMed Central

    Valentijn, Pim P.; Boesveld, Inge C.; van der Klauw, Denise M.; Ruwaard, Dirk; Struijs, Jeroen N.; Molema, Johanna J.W.; Bruijnzeels, Marc A.; Vrijhoef, Hubertus JM.

    2015-01-01

    Introduction Building integrated services in a primary care setting is considered an essential important strategy for establishing a high-quality and affordable health care system. The theoretical foundations of such integrated service models are described by the Rainbow Model of Integrated Care, which distinguishes six integration dimensions (clinical, professional, organisational, system, functional and normative integration). The aim of the present study is to refine the Rainbow Model of Integrated Care by developing a taxonomy that specifies the underlying key features of the six dimensions. Methods First, a literature review was conducted to identify features for achieving integrated service delivery. Second, a thematic analysis method was used to develop a taxonomy of key features organised into the dimensions of the Rainbow Model of Integrated Care. Finally, the appropriateness of the key features was tested in a Delphi study among Dutch experts. Results The taxonomy consists of 59 key features distributed across the six integration dimensions of the Rainbow Model of Integrated Care. Key features associated with the clinical, professional, organisational and normative dimensions were considered appropriate by the experts. Key features linked to the functional and system dimensions were considered less appropriate. Discussion This study contributes to the ongoing debate of defining the concept and typology of integrated care. This taxonomy provides a development agenda for establishing an accepted scientific framework of integrated care from an end-user, professional, managerial and policy perspective. PMID:25759607

  9. Joining direct and indirect inverse calibration methods to characterize karst, coastal aquifers

    NASA Astrophysics Data System (ADS)

    De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio

    2016-04-01

    Parameter estimation is extremely relevant for accurate simulation of groundwater flow. Parameter values for models of large-scale catchments are usually derived from a limited set of field observations, which can rarely be obtained in a straightforward way from field tests or laboratory measurements on samples, due to a number of factors, including measurement errors and inadequate sampling density. Indeed, a wide gap exists between the local scale, at which most of the observations are taken, and the regional or basin scale, at which the planning and management decisions are usually made. For this reason, the use of geologic information and field data is generally made by zoning the parameter fields. However, pure zoning does not perform well in the case of fairly complex aquifers and this is particularly true for karst aquifers. In fact, the support of the hydraulic conductivity measured in the field is normally much smaller than the cell size of the numerical model, so it should be upscaled to a scale consistent with that of the numerical model discretization. Automatic inverse calibration is a valuable procedure to identify model parameter values by conditioning on observed, available data, limiting the subjective evaluations introduced with the trial-and-error technique. Many approaches have been proposed to solve the inverse problem. Generally speaking, inverse methods fall into two groups: direct and indirect methods. Direct methods allow determination of hydraulic conductivities from the groundwater flow equations which relate the conductivity and head fields. Indirect methods, instead, can handle any type of parameters, independently from the mathematical equations that govern the process, and condition parameter values and model construction on measurements of model output quantities, compared with the available observation data, through the minimization of an objective function. Both approaches have pros and cons, depending also on model complexity. For

  10. Sleep can eliminate list-method directed forgetting.

    PubMed

    Abel, Magdalena; Bäuml, Karl-Heinz T

    2013-05-01

    Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when cued to do so. We applied the list-method directed forgetting task and assessed memory performance after 3 delay intervals. Directed forgetting was present after a short 20-min delay and after a 12-hr delay filled with diurnal wakefulness; in contrast, the forgetting was absent after a 12-hr delay that included regular nocturnal sleep. Successful directed forgetting after a delay thus can depend on whether sleep or wakefulness follows upon encoding: When wakefulness follows upon encoding, the forgetting can be successful; when sleep follows upon encoding, no forgetting may arise. Connections of the results to recent studies on the interplay between forgetting and sleep are discussed.

  11. Assessing Backwards Integration as a Method of KBO Family Finding

    NASA Astrophysics Data System (ADS)

    Benfell, Nathan; Ragozzine, Darin

    2018-04-01

    The age of young asteroid collisional families can sometimes be determined by using backwards n-body integrations of the solar system. This method is not used for discovering young asteroid families and is limited by the unpredictable influence of the Yarkovsky effect on individual specific asteroids over time. Since these limitations are not as important for objects in the Kuiper belt, Marcus et al. 2011 suggested that backwards integration could be used to discover and characterize collisional families in the outer solar system. But various challenges present themselves when running precise and accurate 4+ Gyr integrations of Kuiper Belt objects. We have created simulated families of Kuiper Belt Objects with identical starting locations and velocity distributions, based on the Haumea Family. We then ran several long-term test integrations to observe the effect of various simulation parameters on integration results. These integrations were then used to investigate which parameters are of enough significance to require inclusion in the integration. Thereby we determined how to construct long-term integrations that both yield significant results and require manageable processing power. Additionally, we have tested the use of backwards integration as a method of discovery of potential young families in the Kuiper Belt.

  12. Discovery of potent KIFC1 inhibitors using a method of integrated high-throughput synthesis and screening.

    PubMed

    Yang, Bin; Lamb, Michelle L; Zhang, Tao; Hennessy, Edward J; Grewal, Gurmit; Sha, Li; Zambrowski, Mark; Block, Michael H; Dowling, James E; Su, Nancy; Wu, Jiaquan; Deegan, Tracy; Mikule, Keith; Wang, Wenxian; Kaspera, Rüdiger; Chuaqui, Claudio; Chen, Huawei

    2014-12-11

    KIFC1 (HSET), a member of the kinesin-14 family of motor proteins, plays an essential role in centrosomal bundling in cancer cells, but its function is not required for normal diploid cell division. To explore the potential of KIFC1 as a therapeutic target for human cancers, a series of potent KIFC1 inhibitors featuring a phenylalanine scaffold was developed from hits identified through high-throughput screening (HTS). Optimization of the initial hits combined both design-synthesis-test cycles and an integrated high-throughput synthesis and biochemical screening method. An important aspect of this integrated method was the utilization of DMSO stock solutions of compounds registered in the corporate compound collection as synthetic reactants. Using this method, over 1500 compounds selected for structural diversity were quickly assembled in assay-ready 384-well plates and were directly tested after the necessary dilutions. Our efforts led to the discovery of a potent KIFC1 inhibitor, AZ82, which demonstrated the desired centrosome declustering mode of action in cell studies.

  13. A high-order relaxation method with projective integration for solving nonlinear systems of hyperbolic conservation laws

    NASA Astrophysics Data System (ADS)

    Lafitte, Pauline; Melis, Ward; Samaey, Giovanni

    2017-07-01

    We present a general, high-order, fully explicit relaxation scheme which can be applied to any system of nonlinear hyperbolic conservation laws in multiple dimensions. The scheme consists of two steps. In a first (relaxation) step, the nonlinear hyperbolic conservation law is approximated by a kinetic equation with stiff BGK source term. Then, this kinetic equation is integrated in time using a projective integration method. After taking a few small (inner) steps with a simple, explicit method (such as direct forward Euler) to damp out the stiff components of the solution, the time derivative is estimated and used in an (outer) Runge-Kutta method of arbitrary order. We show that, with an appropriate choice of inner step size, the time step restriction on the outer time step is similar to the CFL condition for the hyperbolic conservation law. Moreover, the number of inner time steps is also independent of the stiffness of the BGK source term. We discuss stability and consistency, and illustrate with numerical results (linear advection, Burgers' equation and the shallow water and Euler equations) in one and two spatial dimensions.

  14. Accurate Time/Frequency Transfer Method Using Bi-Directional WDM Transmission

    NASA Technical Reports Server (NTRS)

    Imaoka, Atsushi; Kihara, Masami

    1996-01-01

    An accurate time transfer method is proposed using b-directional wavelength division multiplexing (WDM) signal transmission along a single optical fiber. This method will be used in digital telecommunication networks and yield a time synchronization accuracy of better than 1 ns for long transmission lines over several tens of kilometers. The method can accurately measure the difference in delay between two wavelength signals caused by the chromatic dispersion of the fiber in conventional simple bi-directional dual-wavelength frequency transfer methods. We describe the characteristics of this difference in delay and then show that the accuracy of the delay measurements can be obtained below 0.1 ns by transmitting 156 Mb/s times reference signals of 1.31 micrometer and 1.55 micrometers along a 50 km fiber using the proposed method. The sub-nanosecond delay measurement using the simple bi-directional dual-wavelength transmission along a 100 km fiber with a wavelength spacing of 1 nm in the 1.55 micrometer range is also shown.

  15. Package for integrated optic circuit and method

    DOEpatents

    Kravitz, Stanley H.; Hadley, G. Ronald; Warren, Mial E.; Carson, Richard F.; Armendariz, Marcelino G.

    1998-01-01

    A structure and method for packaging an integrated optic circuit. The package comprises a first wall having a plurality of microlenses formed therein to establish channels of optical communication with an integrated optic circuit within the package. A first registration pattern is provided on an inside surface of one of the walls of the package for alignment and attachment of the integrated optic circuit. The package in one embodiment may further comprise a fiber holder for aligning and attaching a plurality of optical fibers to the package and extending the channels of optical communication to the fibers outside the package. In another embodiment, a fiber holder may be used to hold the fibers and align the fibers to the package. The fiber holder may be detachably connected to the package.

  16. Package for integrated optic circuit and method

    DOEpatents

    Kravitz, S.H.; Hadley, G.R.; Warren, M.E.; Carson, R.F.; Armendariz, M.G.

    1998-08-04

    A structure and method are disclosed for packaging an integrated optic circuit. The package comprises a first wall having a plurality of microlenses formed therein to establish channels of optical communication with an integrated optic circuit within the package. A first registration pattern is provided on an inside surface of one of the walls of the package for alignment and attachment of the integrated optic circuit. The package in one embodiment may further comprise a fiber holder for aligning and attaching a plurality of optical fibers to the package and extending the channels of optical communication to the fibers outside the package. In another embodiment, a fiber holder may be used to hold the fibers and align the fibers to the package. The fiber holder may be detachably connected to the package. 6 figs.

  17. Vacuum decay container closure integrity leak test method development and validation for a lyophilized product-package system.

    PubMed

    Patel, Jayshree; Mulhall, Brian; Wolf, Heinz; Klohr, Steven; Guazzo, Dana Morton

    2011-01-01

    A leak test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method was developed and validated for container-closure integrity verification of a lyophilized product in a parenteral vial package system. This nondestructive leak test method is intended for use in manufacturing as an in-process package integrity check, and for testing product stored on stability in lieu of sterility tests. Method development and optimization challenge studies incorporated artificially defective packages representing a range of glass vial wall and sealing surface defects, as well as various elastomeric stopper defects. Method validation required 3 days of random-order replicate testing of a test sample population of negative-control, no-defect packages and positive-control, with-defect packages. Positive-control packages were prepared using vials each with a single hole laser-drilled through the glass vial wall. Hole creation and hole size certification was performed by Lenox Laser. Validation study results successfully demonstrated the vacuum decay leak test method's ability to accurately and reliably detect those packages with laser-drilled holes greater than or equal to approximately 5 μm in nominal diameter. All development and validation studies were performed at Whitehouse Analytical Laboratories in Whitehouse, NJ, under the direction of consultant Dana Guazzo of RxPax, LLC, using a VeriPac 455 Micro Leak Test System by Packaging Technologies & Inspection (Tuckahoe, NY). Bristol Myers Squibb (New Brunswick, NJ) fully subsidized all work. A leak test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method was developed and validated to detect defects in stoppered vial packages containing lyophilized product for injection. This nondestructive leak test method is intended for use in manufacturing as an in-process package integrity

  18. Accelerometer method and apparatus for integral display and control functions

    NASA Astrophysics Data System (ADS)

    Bozeman, Richard J., Jr.

    1992-06-01

    Vibration analysis has been used for years to provide a determination of the proper functioning of different types of machinery, including rotating machinery and rocket engines. A determination of a malfunction, if detected at a relatively early stage in its development, will allow changes in operating mode or a sequenced shutdown of the machinery prior to a total failure. Such preventative measures result in less extensive and/or less expensive repairs, and can also prevent a sometimes catastrophic failure of equipment. Standard vibration analyzers are generally rather complex, expensive, and of limited portability. They also usually result in displays and controls being located remotely from the machinery being monitored. Consequently, a need exists for improvements in accelerometer electronic display and control functions which are more suitable for operation directly on machines and which are not so expensive and complex. The invention includes methods and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. The apparatus includes an accelerometer package having integral display and control functions. The accelerometer package is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine condition over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase over the selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated. The benefits of a vibration recording and monitoring system with controls and displays readily

  19. Accelerometer method and apparatus for integral display and control functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1992-01-01

    Vibration analysis has been used for years to provide a determination of the proper functioning of different types of machinery, including rotating machinery and rocket engines. A determination of a malfunction, if detected at a relatively early stage in its development, will allow changes in operating mode or a sequenced shutdown of the machinery prior to a total failure. Such preventative measures result in less extensive and/or less expensive repairs, and can also prevent a sometimes catastrophic failure of equipment. Standard vibration analyzers are generally rather complex, expensive, and of limited portability. They also usually result in displays and controls being located remotely from the machinery being monitored. Consequently, a need exists for improvements in accelerometer electronic display and control functions which are more suitable for operation directly on machines and which are not so expensive and complex. The invention includes methods and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. The apparatus includes an accelerometer package having integral display and control functions. The accelerometer package is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine condition over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase over the selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated. The benefits of a vibration recording and monitoring system with controls and displays readily

  20. Cutting Force Predication Based on Integration of Symmetric Fuzzy Number and Finite Element Method

    PubMed Central

    Wang, Zhanli; Hu, Yanjuan; Wang, Yao; Dong, Chao; Pang, Zaixiang

    2014-01-01

    In the process of turning, pointing at the uncertain phenomenon of cutting which is caused by the disturbance of random factors, for determining the uncertain scope of cutting force, the integrated symmetric fuzzy number and the finite element method (FEM) are used in the prediction of cutting force. The method used symmetric fuzzy number to establish fuzzy function between cutting force and three factors and obtained the uncertain interval of cutting force by linear programming. At the same time, the change curve of cutting force with time was directly simulated by using thermal-mechanical coupling FEM; also the nonuniform stress field and temperature distribution of workpiece, tool, and chip under the action of thermal-mechanical coupling were simulated. The experimental result shows that the method is effective for the uncertain prediction of cutting force. PMID:24790556

  1. Direct linearizing transform for three-dimensional discrete integrable systems: the lattice AKP, BKP and CKP equations.

    PubMed

    Fu, Wei; Nijhoff, Frank W

    2017-07-01

    A unified framework is presented for the solution structure of three-dimensional discrete integrable systems, including the lattice AKP, BKP and CKP equations. This is done through the so-called direct linearizing transform, which establishes a general class of integral transforms between solutions. As a particular application, novel soliton-type solutions for the lattice CKP equation are obtained.

  2. Apparatus and method for a light direction sensor

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B. (Inventor)

    2011-01-01

    The present invention provides a light direction sensor for determining the direction of a light source. The system includes an image sensor; a spacer attached to the image sensor, and a pattern mask attached to said spacer. The pattern mask has a slit pattern that as light passes through the slit pattern it casts a diffraction pattern onto the image sensor. The method operates by receiving a beam of light onto a patterned mask, wherein the patterned mask as a plurality of a slit segments. Then, diffusing the beam of light onto an image sensor and determining the direction of the light source.

  3. Primitive Auditory Memory Is Correlated with Spatial Unmasking That Is Based on Direct-Reflection Integration

    PubMed Central

    Li, Huahui; Kong, Lingzhi; Wu, Xihong; Li, Liang

    2013-01-01

    In reverberant rooms with multiple-people talking, spatial separation between speech sources improves recognition of attended speech, even though both the head-shadowing and interaural-interaction unmasking cues are limited by numerous reflections. It is the perceptual integration between the direct wave and its reflections that bridges the direct-reflection temporal gaps and results in the spatial unmasking under reverberant conditions. This study further investigated (1) the temporal dynamic of the direct-reflection-integration-based spatial unmasking as a function of the reflection delay, and (2) whether this temporal dynamic is correlated with the listeners’ auditory ability to temporally retain raw acoustic signals (i.e., the fast decaying primitive auditory memory, PAM). The results showed that recognition of the target speech against the speech-masker background is a descending exponential function of the delay of the simulated target reflection. In addition, the temporal extent of PAM is frequency dependent and markedly longer than that for perceptual fusion. More importantly, the temporal dynamic of the speech-recognition function is significantly correlated with the temporal extent of the PAM of low-frequency raw signals. Thus, we propose that a chain process, which links the earlier-stage PAM with the later-stage correlation computation, perceptual integration, and attention facilitation, plays a role in spatially unmasking target speech under reverberant conditions. PMID:23658664

  4. Evaluation of Two New Smoothing Methods in Equating: The Cubic B-Spline Presmoothing Method and the Direct Presmoothing Method

    ERIC Educational Resources Information Center

    Cui, Zhongmin; Kolen, Michael J.

    2009-01-01

    This article considers two new smoothing methods in equipercentile equating, the cubic B-spline presmoothing method and the direct presmoothing method. Using a simulation study, these two methods are compared with established methods, the beta-4 method, the polynomial loglinear method, and the cubic spline postsmoothing method, under three sample…

  5. Direct Linear Transformation Method for Three-Dimensional Cinematography

    ERIC Educational Resources Information Center

    Shapiro, Robert

    1978-01-01

    The ability of Direct Linear Transformation Method for three-dimensional cinematography to locate points in space was shown to meet the accuracy requirements associated with research on human movement. (JD)

  6. The LAM-PCR Method to Sequence LV Integration Sites.

    PubMed

    Wang, Wei; Bartholomae, Cynthia C; Gabriel, Richard; Deichmann, Annette; Schmidt, Manfred

    2016-01-01

    Integrating viral gene transfer vectors are commonly used gene delivery tools in clinical gene therapy trials providing stable integration and continuous gene expression of the transgene in the treated host cell. However, integration of the reverse-transcribed vector DNA into the host genome is a potentially mutagenic event that may directly contribute to unwanted side effects. A comprehensive and accurate analysis of the integration site (IS) repertoire is indispensable to study clonality in transduced cells obtained from patients undergoing gene therapy and to identify potential in vivo selection of affected cell clones. To date, next-generation sequencing (NGS) of vector-genome junctions allows sophisticated studies on the integration repertoire in vitro and in vivo. We have explored the use of the Illumina MiSeq Personal Sequencer platform to sequence vector ISs amplified by non-restrictive linear amplification-mediated PCR (nrLAM-PCR) and LAM-PCR. MiSeq-based high-quality IS sequence retrieval is accomplished by the introduction of a double-barcode strategy that substantially minimizes the frequency of IS sequence collisions compared to the conventionally used single-barcode protocol. Here, we present an updated protocol of (nr)LAM-PCR for the analysis of lentiviral IS using a double-barcode system and followed by deep sequencing using the MiSeq device.

  7. Method and apparatus for determining material structural integrity

    DOEpatents

    Pechersky, M.J.

    1994-01-01

    Disclosed are a nondestructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis to determine the damping loss factor. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity vs time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method: if an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the coil current. If a reciprocating transducer is used, the vibrational force is determined by a force gauge in the transducer. Using vibrational analysis, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity data. Damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.

  8. Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements.

    PubMed

    Haskett, Timothy L; Terpolilli, Jason J; Ramachandran, Vinoy K; Verdonk, Callum J; Poole, Phillip S; O'Hara, Graham W; Ramsay, Joshua P

    2018-03-01

    Tripartite integrative and conjugative elements (ICE3) are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionases-or recombination directionality factors-RdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a "master controller" of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer.

  9. Lean direct wall fuel injection method and devices

    NASA Technical Reports Server (NTRS)

    Choi, Kyung J. (Inventor); Tacina, Robert (Inventor)

    2000-01-01

    A fuel combustion chamber, and a method of and a nozzle for mixing liquid fuel and air in the fuel combustion chamber in lean direct injection combustion for advanced gas turbine engines, including aircraft engines. Liquid fuel in a form of jet is injected directly into a cylindrical combustion chamber from the combustion chamber wall surface in a direction opposite to the direction of the swirling air at an angle of from about 50.degree. to about 60.degree. with respect to a tangential line of the cylindrical combustion chamber and at a fuel-lean condition, with a liquid droplet momentum to air momentum ratio in the range of from about 0.05 to about 0.12. Advanced gas turbines benefit from lean direct wall injection combustion. The lean direct wall injection technique of the present invention provides fast, uniform, well-stirred mixing of fuel and air. In addition, in order to further improve combustion, the fuel can be injected at a venturi located in the combustion chamber at a point adjacent the air swirler.

  10. Two-baryon systems from HAL QCD method and the mirage in the temporal correlation of the direct method

    NASA Astrophysics Data System (ADS)

    Iritani, Takumi

    2018-03-01

    Both direct and HAL QCD methods are currently used to study the hadron interactions in lattice QCD. In the direct method, the eigen-energy of two-particle is measured from the temporal correlation. Due to the contamination of excited states, however, the direct method suffers from the fake eigen-energy problem, which we call the "mirage problem," while the HAL QCD method can extract information from all elastic states by using the spatial correlation. In this work, we further investigate systematic uncertainties of the HAL QCD method such as the quark source operator dependence, the convergence of the derivative expansion of the non-local interaction kernel, and the single baryon saturation, which are found to be well controlled. We also confirm the consistency between the HAL QCD method and the Lüscher's finite volume formula. Based on the HAL QCD potential, we quantitatively confirm that the mirage plateau in the direct method is indeed caused by the contamination of excited states.

  11. A monolithic integrated micro direct methanol fuel cell based on sulfo functionalized porous silicon

    NASA Astrophysics Data System (ADS)

    Wang, M.; Lu, Y. X.; Liu, L. T.; Wang, X. H.

    2016-11-01

    In this paper, we demonstrate a monolithic integrated micro direct methanol fuel cell (μDMFC) for the first time. The monolithic integrated μDMFC combines proton exchange membrane (PEM) and Pt nanocatalysts, in which PEM is achieved by the functionalized porous silicon membrane and 3D Pt nanoflowers being synthesized in situ on it as catalysts. Sulfo groups functionalized porous silicon membrane serves as a PEM and a catalyst support simultaneously. The μDMFC prototype achieves an open circuit voltage of 0.3 V, a maximum power density of 5.5 mW/cm2. The monolithic integrated μDMFC offers several desirable features such as compatibility with micro fabrication techniques, an undeformable solid PEM and the convenience of assembly.

  12. Direct Delta-MBPT(2) method for ionization potentials, electron affinities, and excitation energies using fractional occupation numbers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Beste, Ariana; Vazquez-Mayagoitia, Alvaro; Ortiz, J. Vincent

    2013-01-01

    A direct method (D-Delta-MBPT(2)) to calculate second-order ionization potentials (IPs), electron affinities (EAs), and excitation energies is developed. The Delta-MBPT(2) method is defined as the correlated extension of the Delta-HF method. Energy differences are obtained by integrating the energy derivative with respect to occupation numbers over the appropriate parameter range. This is made possible by writing the second-order energy as a function of the occupation numbers. Relaxation effects are fully included at the SCF level. This is in contrast to linear response theory, which makes the D-Delta-MBPT(2) applicable not only to single excited but also higher excited states. We showmore » the relationship of the D-Delta-MBPT(2) method for IPs and EAs to a second-order approximation of the effective Fock-space coupled-cluster Hamiltonian and a second-order electron propagator method. We also discuss the connection between the D-Delta-MBPT(2) method for excitation energies and the CIS-MP2 method. Finally, as a proof of principle, we apply our method to calculate ionization potentials and excitation energies of some small molecules. For IPs, the Delta-MBPT(2) results compare well to the second-order solution of the Dyson equation. For excitation energies, the deviation from EOM-CCSD increases when correlation becomes more important. When using the numerical integration technique, we encounter difficulties that prevented us from reaching the Delta-MBPT(2) values. Most importantly, relaxation beyond the Hartree Fock level is significant and needs to be included in future research.« less

  13. On the method of Ermakov and Zolotukhin for multiple integration

    NASA Technical Reports Server (NTRS)

    Cranley, R.; Patterson, T. N. L.

    1971-01-01

    By introducing the idea of pseudo-implementation, a practical assessment of the method for multiple integration is made. The performance of the method is found to be unimpressive in comparison with a recent regression method.

  14. Integrating Financial Aid and Financial Policies: Case Studies from Five States. Changing Direction: Integrating Higher Education Financial Aid and Financing Policies.

    ERIC Educational Resources Information Center

    Western Interstate Commission for Higher Education, Boulder, CO.

    This report is a collection of five state case studies comprising a major component of the first phase of the project, "Changing Direction: Integrating Higher Education Financial Aid and Financing Policies." The project explored state-level strategies to better align financing and financial aid policies and support more informed decision…

  15. Push-through direct injection NMR: an optimized automation method applied to metabolomics

    EPA Science Inventory

    There is a pressing need to increase the throughput of NMR analysis in fields such as metabolomics and drug discovery. Direct injection (DI) NMR automation is recognized to have the potential to meet this need due to its suitability for integration with the 96-well plate format. ...

  16. Adaptive integration of habits into depth-limited planning defines a habitual-goal–directed spectrum

    PubMed Central

    Keramati, Mehdi; Smittenaar, Peter; Dolan, Raymond J.; Dayan, Peter

    2016-01-01

    Behavioral and neural evidence reveal a prospective goal-directed decision process that relies on mental simulation of the environment, and a retrospective habitual process that caches returns previously garnered from available choices. Artificial systems combine the two by simulating the environment up to some depth and then exploiting habitual values as proxies for consequences that may arise in the further future. Using a three-step task, we provide evidence that human subjects use such a normative plan-until-habit strategy, implying a spectrum of approaches that interpolates between habitual and goal-directed responding. We found that increasing time pressure led to shallower goal-directed planning, suggesting that a speed-accuracy tradeoff controls the depth of planning with deeper search leading to more accurate evaluation, at the cost of slower decision-making. We conclude that subjects integrate habit-based cached values directly into goal-directed evaluations in a normative manner. PMID:27791110

  17. Electron beam directed energy device and methods of using same

    DOEpatents

    Retsky, Michael W.

    2007-10-16

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  18. A Multi-Index Integrated Change detection method for updating the National Land Cover Database

    USGS Publications Warehouse

    Jin, Suming; Yang, Limin; Xian, George Z.; Danielson, Patrick; Homer, Collin G.

    2010-01-01

    Land cover change is typically captured by comparing two or more dates of imagery and associating spectral change with true thematic change. A new change detection method, Multi-Index Integrated Change (MIIC), has been developed to capture a full range of land cover disturbance patterns for updating the National Land Cover Database (NLCD). Specific indices typically specialize in identifying only certain types of disturbances; for example, the Normalized Burn Ratio (NBR) has been widely used for monitoring fire disturbance. Recognizing the potential complementary nature of multiple indices, we integrated four indices into one model to more accurately detect true change between two NLCD time periods. The four indices are NBR, Normalized Difference Vegetation Index (NDVI), Change Vector (CV), and a newly developed index called the Relative Change Vector (RCV). The model is designed to provide both change location and change direction (e.g. biomass increase or biomass decrease). The integrated change model has been tested on five image pairs from different regions exhibiting a variety of disturbance types. Compared with a simple change vector method, MIIC can better capture the desired change without introducing additional commission errors. The model is particularly accurate at detecting forest disturbances, such as forest harvest, forest fire, and forest regeneration. Agreement between the initial change map areas derived from MIIC and the retained final land cover type change areas will be showcased from the pilot test sites.

  19. Integrals and integral equations in linearized wing theory

    NASA Technical Reports Server (NTRS)

    Lomax, Harvard; Heaslet, Max A; Fuller, Franklyn B

    1951-01-01

    The formulas of subsonic and supersonic wing theory for source, doublet, and vortex distributions are reviewed and a systematic presentation is provided which relates these distributions to the pressure and to the vertical induced velocity in the plane of the wing. It is shown that care must be used in treating the singularities involved in the analysis and that the order of integration is not always reversible. Concepts suggested by the irreversibility of order of integration are shown to be useful in the inversion of singular integral equations when operational techniques are used. A number of examples are given to illustrate the methods presented, attention being directed to supersonic flight speed.

  20. Integral methods of solving boundary-value problems of nonstationary heat conduction and their comparative analysis

    NASA Astrophysics Data System (ADS)

    Kot, V. A.

    2017-11-01

    The modern state of approximate integral methods used in applications, where the processes of heat conduction and heat and mass transfer are of first importance, is considered. Integral methods have found a wide utility in different fields of knowledge: problems of heat conduction with different heat-exchange conditions, simulation of thermal protection, Stefantype problems, microwave heating of a substance, problems on a boundary layer, simulation of a fluid flow in a channel, thermal explosion, laser and plasma treatment of materials, simulation of the formation and melting of ice, inverse heat problems, temperature and thermal definition of nanoparticles and nanoliquids, and others. Moreover, polynomial solutions are of interest because the determination of a temperature (concentration) field is an intermediate stage in the mathematical description of any other process. The following main methods were investigated on the basis of the error norms: the Tsoi and Postol’nik methods, the method of integral relations, the Gudman integral method of heat balance, the improved Volkov integral method, the matched integral method, the modified Hristov method, the Mayer integral method, the Kudinov method of additional boundary conditions, the Fedorov boundary method, the method of weighted temperature function, the integral method of boundary characteristics. It was established that the two last-mentioned methods are characterized by high convergence and frequently give solutions whose accuracy is not worse that the accuracy of numerical solutions.

  1. Clinical attachment loss: estimation by direct and indirect methods.

    PubMed

    Barbosa, Viviane Leal; Angst, Patricia D Melchiors; Finger Stadler, Amanda; Oppermann, Rui V; Gomes, Sabrina Carvalho

    2016-06-01

    This observational study aimed to compare the estimation of clinical attachment loss (CAL) as measured by direct (CALD ) and indirect (CALI ) methods. Periodontitis patients (n = 75; mean age: 50.9 ± 8.02 years; 72.2% women; 50.6% smokers) received a periodontal examination (six sites/tooth) to determine the presence of visible plaque and calculus, the gingival bleeding index (GBI), periodontal probing depth (PPD), bleeding on probing (BOP), CALD and gingival recession (GR). CALI values resulted from the sum of PPD and GR values. Statistical analysis considered only data from sites with visible GR (e.g. the gingival margin apical to the cemento-enamel junction; n = 4,757 sites) and determined the mean difference between CALI and CALD measurements. Based on the mean difference, univariate and multivariate analyses were also performed. Mean CALD and CALI values were 3.96 ± 2.07 mm and 4.47 ± 2.03 mm, respectively. The indirect method overestimated CAL compared with the direct method (mean difference: 0.51 ± 1.23 mm; P < 0.001). On uni- and multivariate analyses, absence of GBI and BOP, PPD and proximal site location had significant influences on the overestimation of CAL by the indirect method (all P ≤ 0.01). The indirect method increased the CAL value by 0.38 mm for each additional 1 mm in PPD. To decrease the number of probing errors in daily practice it is suggested that direct examination is more appropriate than the indirect method for estimating CAL. © 2016 FDI World Dental Federation.

  2. Cochrane Qualitative and Implementation Methods Group guidance series-paper 5: methods for integrating qualitative and implementation evidence within intervention effectiveness reviews.

    PubMed

    Harden, Angela; Thomas, James; Cargo, Margaret; Harris, Janet; Pantoja, Tomas; Flemming, Kate; Booth, Andrew; Garside, Ruth; Hannes, Karin; Noyes, Jane

    2018-05-01

    The Cochrane Qualitative and Implementation Methods Group develops and publishes guidance on the synthesis of qualitative and mixed-method evidence from process evaluations. Despite a proliferation of methods for the synthesis of qualitative research, less attention has focused on how to integrate these syntheses within intervention effectiveness reviews. In this article, we report updated guidance from the group on approaches, methods, and tools, which can be used to integrate the findings from quantitative studies evaluating intervention effectiveness with those from qualitative studies and process evaluations. We draw on conceptual analyses of mixed methods systematic review designs and the range of methods and tools that have been used in published reviews that have successfully integrated different types of evidence. We outline five key methods and tools as devices for integration which vary in terms of the levels at which integration takes place; the specialist skills and expertise required within the review team; and their appropriateness in the context of limited evidence. In situations where the requirement is the integration of qualitative and process evidence within intervention effectiveness reviews, we recommend the use of a sequential approach. Here, evidence from each tradition is synthesized separately using methods consistent with each tradition before integration takes place using a common framework. Reviews which integrate qualitative and process evaluation evidence alongside quantitative evidence on intervention effectiveness in a systematic way are rare. This guidance aims to support review teams to achieve integration and we encourage further development through reflection and formal testing. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Mixed time integration methods for transient thermal analysis of structures

    NASA Technical Reports Server (NTRS)

    Liu, W. K.

    1982-01-01

    The computational methods used to predict and optimize the thermal structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a different yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.

  4. Mixed time integration methods for transient thermal analysis of structures

    NASA Technical Reports Server (NTRS)

    Liu, W. K.

    1983-01-01

    The computational methods used to predict and optimize the thermal-structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally-useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.

  5. Hybrid Pixel-Based Method for Cardiac Ultrasound Fusion Based on Integration of PCA and DWT

    PubMed Central

    Sulaiman, Puteri Suhaiza; Wirza, Rahmita; Dimon, Mohd Zamrin; Khalid, Fatimah; Moosavi Tayebi, Rohollah

    2015-01-01

    Medical image fusion is the procedure of combining several images from one or multiple imaging modalities. In spite of numerous attempts in direction of automation ventricle segmentation and tracking in echocardiography, due to low quality images with missing anatomical details or speckle noises and restricted field of view, this problem is a challenging task. This paper presents a fusion method which particularly intends to increase the segment-ability of echocardiography features such as endocardial and improving the image contrast. In addition, it tries to expand the field of view, decreasing impact of noise and artifacts and enhancing the signal to noise ratio of the echo images. The proposed algorithm weights the image information regarding an integration feature between all the overlapping images, by using a combination of principal component analysis and discrete wavelet transform. For evaluation, a comparison has been done between results of some well-known techniques and the proposed method. Also, different metrics are implemented to evaluate the performance of proposed algorithm. It has been concluded that the presented pixel-based method based on the integration of PCA and DWT has the best result for the segment-ability of cardiac ultrasound images and better performance in all metrics. PMID:26089965

  6. Hybrid Pixel-Based Method for Cardiac Ultrasound Fusion Based on Integration of PCA and DWT.

    PubMed

    Mazaheri, Samaneh; Sulaiman, Puteri Suhaiza; Wirza, Rahmita; Dimon, Mohd Zamrin; Khalid, Fatimah; Moosavi Tayebi, Rohollah

    2015-01-01

    Medical image fusion is the procedure of combining several images from one or multiple imaging modalities. In spite of numerous attempts in direction of automation ventricle segmentation and tracking in echocardiography, due to low quality images with missing anatomical details or speckle noises and restricted field of view, this problem is a challenging task. This paper presents a fusion method which particularly intends to increase the segment-ability of echocardiography features such as endocardial and improving the image contrast. In addition, it tries to expand the field of view, decreasing impact of noise and artifacts and enhancing the signal to noise ratio of the echo images. The proposed algorithm weights the image information regarding an integration feature between all the overlapping images, by using a combination of principal component analysis and discrete wavelet transform. For evaluation, a comparison has been done between results of some well-known techniques and the proposed method. Also, different metrics are implemented to evaluate the performance of proposed algorithm. It has been concluded that the presented pixel-based method based on the integration of PCA and DWT has the best result for the segment-ability of cardiac ultrasound images and better performance in all metrics.

  7. A Direct Method for Viewing Ferromagnetic Phase Transition.

    ERIC Educational Resources Information Center

    Lue, Chin-Shan

    1994-01-01

    Provides a method, using the Rowland ring as a specimen, to observe the phase transition process directly on the oscilloscope and even extract the critical exponent of ferromagnetic transition. Includes theory, experimental setup, and results. (MVL)

  8. Indoor integrated navigation and synchronous data acquisition method for Android smartphone

    NASA Astrophysics Data System (ADS)

    Hu, Chunsheng; Wei, Wenjian; Qin, Shiqiao; Wang, Xingshu; Habib, Ayman; Wang, Ruisheng

    2015-08-01

    Smartphones are widely used at present. Most smartphones have cameras and kinds of sensors, such as gyroscope, accelerometer and magnet meter. Indoor navigation based on smartphone is very important and valuable. According to the features of the smartphone and indoor navigation, a new indoor integrated navigation method is proposed, which uses MEMS (Micro-Electro-Mechanical Systems) IMU (Inertial Measurement Unit), camera and magnet meter of smartphone. The proposed navigation method mainly involves data acquisition, camera calibration, image measurement, IMU calibration, initial alignment, strapdown integral, zero velocity update and integrated navigation. Synchronous data acquisition of the sensors (gyroscope, accelerometer and magnet meter) and the camera is the base of the indoor navigation on the smartphone. A camera data acquisition method is introduced, which uses the camera class of Android to record images and time of smartphone camera. Two kinds of sensor data acquisition methods are introduced and compared. The first method records sensor data and time with the SensorManager of Android. The second method realizes open, close, data receiving and saving functions in C language, and calls the sensor functions in Java language with JNI interface. A data acquisition software is developed with JDK (Java Development Kit), Android ADT (Android Development Tools) and NDK (Native Development Kit). The software can record camera data, sensor data and time at the same time. Data acquisition experiments have been done with the developed software and Sumsang Note 2 smartphone. The experimental results show that the first method of sensor data acquisition is convenient but lost the sensor data sometimes, the second method is much better in real-time performance and much less in data losing. A checkerboard image is recorded, and the corner points of the checkerboard are detected with the Harris method. The sensor data of gyroscope, accelerometer and magnet meter have

  9. Baryon interactions in lattice QCD: the direct method vs. the HAL QCD potential method

    NASA Astrophysics Data System (ADS)

    Iritani, T.; HAL QCD Collaboration

    We make a detailed comparison between the direct method and the HAL QCD potential method for the baryon-baryon interactions, taking the $\\Xi\\Xi$ system at $m_\\pi= 0.51$ GeV in 2+1 flavor QCD and using both smeared and wall quark sources. The energy shift $\\Delta E_\\mathrm{eff}(t)$ in the direct method shows the strong dependence on the choice of quark source operators, which means that the results with either (or both) source are false. The time-dependent HAL QCD method, on the other hand, gives the quark source independent $\\Xi\\Xi$ potential, thanks to the derivative expansion of the potential, which absorbs the source dependence to the next leading order correction. The HAL QCD potential predicts the absence of the bound state in the $\\Xi\\Xi$($^1$S$_0$) channel at $m_\\pi= 0.51$ GeV, which is also confirmed by the volume dependence of finite volume energy from the potential. We also demonstrate that the origin of the fake plateau in the effective energy shift $\\Delta E_\\mathrm{eff}(t)$ at $t \\sim 1$ fm can be clarified by a few low-lying eigenfunctions and eigenvalues on the finite volume derived from the HAL QCD potential, which implies that the ground state saturation of $\\Xi\\Xi$($^1$S$_0$) requires $t \\sim 10$ fm in the direct method for the smeared source on $(4.3 \\ \\mathrm{fm})^3$ lattice, while the HAL QCD method does not suffer from such a problem.

  10. Singularity Preserving Numerical Methods for Boundary Integral Equations

    NASA Technical Reports Server (NTRS)

    Kaneko, Hideaki (Principal Investigator)

    1996-01-01

    In the past twelve months (May 8, 1995 - May 8, 1996), under the cooperative agreement with Division of Multidisciplinary Optimization at NASA Langley, we have accomplished the following five projects: a note on the finite element method with singular basis functions; numerical quadrature for weakly singular integrals; superconvergence of degenerate kernel method; superconvergence of the iterated collocation method for Hammersteion equations; and singularity preserving Galerkin method for Hammerstein equations with logarithmic kernel. This final report consists of five papers describing these projects. Each project is preceeded by a brief abstract.

  11. Direct Measurement of Cyclic Current-Voltage Responses of Integral Membrane Proteins at a Self-Assembled Lipid-Bilayer-Modified Electrode: Cytochrome f and Cytochrome c Oxidase

    NASA Astrophysics Data System (ADS)

    Salamon, Z.; Hazzard, J. T.; Tollin, G.

    1993-07-01

    Direct cyclic voltage-current responses, produced in the absence of redox mediators, for two detergent-solubilized integral membrane proteins, spinach cytochrome f and beef heart cytochrome c oxidase, have been obtained at an optically transparent indium oxide electrode modified with a self-assembled lipid-bilayer membrane. The results indicate that both proteins interact with the lipid membrane so as to support quasi-reversible electron transfer redox reactions at the semiconductor electrode. The redox potentials that were obtained from analysis of the cyclic "voltammograms," 365 mV for cytochrome f and 250 and 380 mV for cytochrome c oxidase (vs. normal hydrogen electrode), compare quite well with the values reported by using conventional titration methods. The ability to obtain direct electrochemical measurements opens up another approach to the investigation of the properties of integral membrane redox proteins.

  12. Numerical quadrature methods for integrals of singular periodic functions and their application to singular and weakly singular integral equations

    NASA Technical Reports Server (NTRS)

    Sidi, A.; Israeli, M.

    1986-01-01

    High accuracy numerical quadrature methods for integrals of singular periodic functions are proposed. These methods are based on the appropriate Euler-Maclaurin expansions of trapezoidal rule approximations and their extrapolations. They are used to obtain accurate quadrature methods for the solution of singular and weakly singular Fredholm integral equations. Such periodic equations are used in the solution of planar elliptic boundary value problems, elasticity, potential theory, conformal mapping, boundary element methods, free surface flows, etc. The use of the quadrature methods is demonstrated with numerical examples.

  13. Method and apparatus for determining material structural integrity

    DOEpatents

    Pechersky, Martin

    1996-01-01

    A non-destructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis techniques to determine the damping loss factor of a material. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity as a function of time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method. If an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the amount of coil current used in vibrating the magnet. If a reciprocating transducer is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by a force gauge in the reciprocating transducer. Using known vibrational analysis methods, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity measurements. The damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.

  14. Comparison of direct and indirect methods of measuring airborne chrysotile fibre concentration.

    PubMed

    Eypert-Blaison, Celine; Veissiere, Sylvie; Rastoix, Olivier; Kauffer, Edmond

    2010-01-01

    Transmission electron microscopy observations most frequently form a basis for estimating asbestos fibre concentration in the environment and in buildings with asbestos-containing materials. Sampled fibres can be transferred to microscope grids by applying either a direct [ISO (1995) Draft International ISO/DIS 10312. Ambient air. Determination of asbestos fibres. Direct transfer transmission electron microscopy procedure. Geneva, Switzerland: International Standardization Organization] or an indirect [AFNOR (1996) Détermination de la concentration en fibres d'amiante par microscopie électronique à transmission-Méthode indirecte. Cedex, France: AFNOR, p. 42; ISO (1997) Draft International ISO/DIS 13794. Ambient air. Determination of asbestos fibres. Indirect-transfer transmission electron microscopy procedure. Geneva, Switzerland: International Standardization Organization] method. In the latter case, ISO Standard 13794 recommends filtering calcination residues either on a polycarbonate (PC) filter (PC indirect method) or on a cellulose ester (CE) membrane (CE indirect method). The PC indirect method requires that fibres deposited on a PC filter be covered by a carbon layer, whereas in the CE indirect method, the CE membrane has to be directly processed using a method described in ISO Standard 10312. The purpose of this study was to compare results obtained using, on the one hand, direct preparation methods and, on the other hand, PC indirect or CE indirect methods, for counting asbestos fibres deposited on filters as a result of liquid filtration or air sampling. In direct method-based preparation, we observed that an etching time of 6-14 min does not affect the measured densities, except for fibres <1 microm deposited by liquid filtration. Moreover, in all cases, the direct method gives higher densities than the PC indirect method because of possible fibre disappearance when using the carbon evaporator implemented in the PC indirect method. The CE membrane

  15. Comparison of Three Different Methods for Pile Integrity Testing on a Cylindrical Homogeneous Polyamide Specimen

    NASA Astrophysics Data System (ADS)

    Lugovtsova, Y. D.; Soldatov, A. I.

    2016-01-01

    Three different methods for pile integrity testing are proposed to compare on a cylindrical homogeneous polyamide specimen. The methods are low strain pile integrity testing, multichannel pile integrity testing and testing with a shaker system. Since the low strain pile integrity testing is well-established and standardized method, the results from it are used as a reference for other two methods.

  16. Accelerated Adaptive Integration Method

    PubMed Central

    2015-01-01

    Conformational changes that occur upon ligand binding may be too slow to observe on the time scales routinely accessible using molecular dynamics simulations. The adaptive integration method (AIM) leverages the notion that when a ligand is either fully coupled or decoupled, according to λ, barrier heights may change, making some conformational transitions more accessible at certain λ values. AIM adaptively changes the value of λ in a single simulation so that conformations sampled at one value of λ seed the conformational space sampled at another λ value. Adapting the value of λ throughout a simulation, however, does not resolve issues in sampling when barriers remain high regardless of the λ value. In this work, we introduce a new method, called Accelerated AIM (AcclAIM), in which the potential energy function is flattened at intermediate values of λ, promoting the exploration of conformational space as the ligand is decoupled from its receptor. We show, with both a simple model system (Bromocyclohexane) and the more complex biomolecule Thrombin, that AcclAIM is a promising approach to overcome high barriers in the calculation of free energies, without the need for any statistical reweighting or additional processors. PMID:24780083

  17. Methods to Fabricate and Improve Stand-alone and Integrated Filters

    NASA Technical Reports Server (NTRS)

    Greer, Frank (Inventor); Nikzad, Shouleh (Inventor)

    2014-01-01

    Embodiments of the invention provide for fabricating a filter, for electromagnetic radiation, in at least three ways, including (1) fabricating integrated thin film filters directly on a detector; (2) fabricating a free standing thin film filter that may be used with a detector; and (3) treating an existing filter to improve the filter's properties.

  18. Simulating biochemical physics with computers: 1. Enzyme catalysis by phosphotriesterase and phosphodiesterase; 2. Integration-free path-integral method for quantum-statistical calculations

    NASA Astrophysics Data System (ADS)

    Wong, Kin-Yiu

    We have simulated two enzymatic reactions with molecular dynamics (MD) and combined quantum mechanical/molecular mechanical (QM/MM) techniques. One reaction is the hydrolysis of the insecticide paraoxon catalyzed by phosphotriesterase (PTE). PTE is a bioremediation candidate for environments contaminated by toxic nerve gases (e.g., sarin) or pesticides. Based on the potential of mean force (PMF) and the structural changes of the active site during the catalysis, we propose a revised reaction mechanism for PTE. Another reaction is the hydrolysis of the second-messenger cyclic adenosine 3'-5'-monophosphate (cAMP) catalyzed by phosphodiesterase (PDE). Cyclicnucleotide PDE is a vital protein in signal-transduction pathways and thus a popular target for inhibition by drugs (e.g., ViagraRTM). A two-dimensional (2-D) free-energy profile has been generated showing that the catalysis by PDE proceeds in a two-step SN2-type mechanism. Furthermore, to characterize a chemical reaction mechanism in experiment, a direct probe is measuring kinetic isotope effects (KIEs). KIEs primarily arise from internuclear quantum-statistical effects, e.g., quantum tunneling and quantization of vibration. To systematically incorporate the quantum-statistical effects during MD simulations, we have developed an automated integration-free path-integral (AIF-PI) method based on Kleinert's variational perturbation theory for the centroid density of Feynman's path integral. Using this analytic method, we have performed ab initio pathintegral calculations to study the origin of KIEs on several series of proton-transfer reactions from carboxylic acids to aryl substituted alpha-methoxystyrenes in water. In addition, we also demonstrate that the AIF-PI method can be used to systematically compute the exact value of zero-point energy (beyond the harmonic approximation) by simply minimizing the centroid effective potential.

  19. The Integrated Multi-Level Bilingual Teaching of "Social Research Methods"

    ERIC Educational Resources Information Center

    Zhu, Yanhan; Ye, Jian

    2012-01-01

    "Social Research Methods," as a methodology course, combines theories and practices closely. Based on the synergy theory, this paper tries to establish an integrated multi-level bilingual teaching mode. Starting from the transformation of teaching concepts, we should integrate interactions, experiences, and researches together and focus…

  20. Methods for Specific Electrode Resistance Measurement during Transcranial Direct Current Stimulation

    PubMed Central

    Khadka, Niranjan; Rahman, Asif; Sarantos, Chris; Truong, Dennis Q.; Bikson, Marom

    2014-01-01

    Background Transcranial Direct Current Stimulation (tDCS) is investigated to treat a wide range of neuropsychiatric disorders, for rehabilitation, and for enhancing cognitive performance. The monitoring of electrode resistance before and during tDCS is considered important for tolerability and safety, where an unusually high resistance is indicative of undesired electrode or poor skin contact conditions. Conventional resistance measurement methods do not isolate individual electrode resistance but rather measures overall voltage. Moreover, for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective We propose a novel method for monitoring of the individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low-intensity and low-frequency sinusoids with electrode– specific frequencies) and a single sentinel electrode (not used for DC). Methods To validate this methodology, we developed lumped-parameter models of two and multi-electrode tDCS. Approaches with and without a sentinel electrode were solved and underlying assumptions identified. Assumptions were tested and parameterized in healthy participants using forearm stimulation combining tDCS (2 mA) and sinusoidal test-signals (38 μA and 76 μA peak to peak at 1 Hz, 10 Hz, and 100 Hz) and an in vitro test (where varied electrode failure modes were created). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain. Results A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. For multi-electrode resistance tracking, cross talk was aggravated with electrode proximity and current/resistance mismatches, but could be corrected using proposed approaches. Average voltage and average pain scores were not significantly different across test current intensities and frequencies (two-way repeated measures ANOVA) indicating the

  1. Direct numerical solution of the Ornstein-Zernike integral equation and spatial distribution of water around hydrophobic molecules

    NASA Astrophysics Data System (ADS)

    Ikeguchi, Mitsunori; Doi, Junta

    1995-09-01

    The Ornstein-Zernike integral equation (OZ equation) has been used to evaluate the distribution function of solvents around solutes, but its numerical solution is difficult for molecules with a complicated shape. This paper proposes a numerical method to directly solve the OZ equation by introducing the 3D lattice. The method employs no approximation the reference interaction site model (RISM) equation employed. The method enables one to obtain the spatial distribution of spherical solvents around solutes with an arbitrary shape. Numerical accuracy is sufficient when the grid-spacing is less than 0.5 Å for solvent water. The spatial water distribution around a propane molecule is demonstrated as an example of a nonspherical hydrophobic molecule using iso-value surfaces. The water model proposed by Pratt and Chandler is used. The distribution agrees with the molecular dynamics simulation. The distribution increases offshore molecular concavities. The spatial distribution of water around 5α-cholest-2-ene (C27H46) is visualized using computer graphics techniques and a similar trend is observed.

  2. Scenario driven data modelling: a method for integrating diverse sources of data and data streams

    PubMed Central

    2011-01-01

    Background Biology is rapidly becoming a data intensive, data-driven science. It is essential that data is represented and connected in ways that best represent its full conceptual content and allows both automated integration and data driven decision-making. Recent advancements in distributed multi-relational directed graphs, implemented in the form of the Semantic Web make it possible to deal with complicated heterogeneous data in new and interesting ways. Results This paper presents a new approach, scenario driven data modelling (SDDM), that integrates multi-relational directed graphs with data streams. SDDM can be applied to virtually any data integration challenge with widely divergent types of data and data streams. In this work, we explored integrating genetics data with reports from traditional media. SDDM was applied to the New Delhi metallo-beta-lactamase gene (NDM-1), an emerging global health threat. The SDDM process constructed a scenario, created a RDF multi-relational directed graph that linked diverse types of data to the Semantic Web, implemented RDF conversion tools (RDFizers) to bring content into the Sematic Web, identified data streams and analytical routines to analyse those streams, and identified user requirements and graph traversals to meet end-user requirements. Conclusions We provided an example where SDDM was applied to a complex data integration challenge. The process created a model of the emerging NDM-1 health threat, identified and filled gaps in that model, and constructed reliable software that monitored data streams based on the scenario derived multi-relational directed graph. The SDDM process significantly reduced the software requirements phase by letting the scenario and resulting multi-relational directed graph define what is possible and then set the scope of the user requirements. Approaches like SDDM will be critical to the future of data intensive, data-driven science because they automate the process of converting

  3. 77 FR 21158 - VA Directive 0005 on Scientific Integrity: Availability for Review and Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ... the Director, Office of Science and Technology Policy's Memorandum of December 17, 2010, on scientific integrity. It addresses how VA ensures quality science in its methods, review, policy application, and...: Background The Presidential Memorandum on Scientific Integrity and the Office of Science and Technology...

  4. Advancing the study of violence against women using mixed methods: integrating qualitative methods into a quantitative research program.

    PubMed

    Testa, Maria; Livingston, Jennifer A; VanZile-Tamsen, Carol

    2011-02-01

    A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women's sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided.

  5. A Direct Method to Extract Transient Sub-Gap Density of State (DOS) Based on Dual Gate Pulse Spectroscopy

    NASA Astrophysics Data System (ADS)

    Dai, Mingzhi; Khan, Karim; Zhang, Shengnan; Jiang, Kemin; Zhang, Xingye; Wang, Weiliang; Liang, Lingyan; Cao, Hongtao; Wang, Pengjun; Wang, Peng; Miao, Lijing; Qin, Haiming; Jiang, Jun; Xue, Lixin; Chu, Junhao

    2016-06-01

    Sub-gap density of states (DOS) is a key parameter to impact the electrical characteristics of semiconductor materials-based transistors in integrated circuits. Previously, spectroscopy methodologies for DOS extractions include the static methods, temperature dependent spectroscopy and photonic spectroscopy. However, they might involve lots of assumptions, calculations, temperature or optical impacts into the intrinsic distribution of DOS along the bandgap of the materials. A direct and simpler method is developed to extract the DOS distribution from amorphous oxide-based thin-film transistors (TFTs) based on Dual gate pulse spectroscopy (GPS), introducing less extrinsic factors such as temperature and laborious numerical mathematical analysis than conventional methods. From this direct measurement, the sub-gap DOS distribution shows a peak value on the band-gap edge and in the order of 1017-1021/(cm3·eV), which is consistent with the previous results. The results could be described with the model involving both Gaussian and exponential components. This tool is useful as a diagnostics for the electrical properties of oxide materials and this study will benefit their modeling and improvement of the electrical properties and thus broaden their applications.

  6. A spectral boundary integral equation method for the 2-D Helmholtz equation

    NASA Technical Reports Server (NTRS)

    Hu, Fang Q.

    1994-01-01

    In this paper, we present a new numerical formulation of solving the boundary integral equations reformulated from the Helmholtz equation. The boundaries of the problems are assumed to be smooth closed contours. The solution on the boundary is treated as a periodic function, which is in turn approximated by a truncated Fourier series. A Fourier collocation method is followed in which the boundary integral equation is transformed into a system of algebraic equations. It is shown that in order to achieve spectral accuracy for the numerical formulation, the nonsmoothness of the integral kernels, associated with the Helmholtz equation, must be carefully removed. The emphasis of the paper is on investigating the essential elements of removing the nonsmoothness of the integral kernels in the spectral implementation. The present method is robust for a general boundary contour. Aspects of efficient implementation of the method using FFT are also discussed. A numerical example of wave scattering is given in which the exponential accuracy of the present numerical method is demonstrated.

  7. Monte Carlo methods for multidimensional integration for European option pricing

    NASA Astrophysics Data System (ADS)

    Todorov, V.; Dimov, I. T.

    2016-10-01

    In this paper, we illustrate examples of highly accurate Monte Carlo and quasi-Monte Carlo methods for multiple integrals related to the evaluation of European style options. The idea is that the value of the option is formulated in terms of the expectation of some random variable; then the average of independent samples of this random variable is used to estimate the value of the option. First we obtain an integral representation for the value of the option using the risk neutral valuation formula. Then with an appropriations change of the constants we obtain a multidimensional integral over the unit hypercube of the corresponding dimensionality. Then we compare a specific type of lattice rules over one of the best low discrepancy sequence of Sobol for numerical integration. Quasi-Monte Carlo methods are compared with Adaptive and Crude Monte Carlo techniques for solving the problem. The four approaches are completely different thus it is a question of interest to know which one of them outperforms the other for evaluation multidimensional integrals in finance. Some of the advantages and disadvantages of the developed algorithms are discussed.

  8. Multiple Site-Directed and Saturation Mutagenesis by the Patch Cloning Method.

    PubMed

    Taniguchi, Naohiro; Murakami, Hiroshi

    2017-01-01

    Constructing protein-coding genes with desired mutations is a basic step for protein engineering. Herein, we describe a multiple site-directed and saturation mutagenesis method, termed MUPAC. This method has been used to introduce multiple site-directed mutations in the green fluorescent protein gene and in the moloney murine leukemia virus reverse transcriptase gene. Moreover, this method was also successfully used to introduce randomized codons at five desired positions in the green fluorescent protein gene, and for simple DNA assembly for cloning.

  9. Systems and methods for integrating ion mobility and ion trap mass spectrometers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ibrahim, Yehia M.; Garimella, Sandilya; Prost, Spencer A.

    Described herein are examples of systems and methods for integrating IMS and MS systems. In certain examples, systems and methods for decoding double multiplexed data are described. The systems and methods can also perform multiple refining procedures in order to minimize the demultiplexing artifacts. The systems and methods can be used, for example, for the analysis of proteomic and petroleum samples, where the integration of IMS and high mass resolution are used for accurate assignment of molecular formulae.

  10. A Rationale for Mixed Methods (Integrative) Research Programmes in Education

    ERIC Educational Resources Information Center

    Niaz, Mansoor

    2008-01-01

    Recent research shows that research programmes (quantitative, qualitative and mixed) in education are not displaced (as suggested by Kuhn) but rather lead to integration. The objective of this study is to present a rationale for mixed methods (integrative) research programs based on contemporary philosophy of science (Lakatos, Giere, Cartwright,…

  11. Concerns of Teacher Education Methods Instructors and Strategies for Integrating Technology into Methods Courses

    ERIC Educational Resources Information Center

    Kim, Miri

    2005-01-01

    The goal of this dissertation is to clarify the perceptions and concerns that methods faculty at a university located in the Midwest have about integrating instructional technology into their courses along with their current use of technology. Ultimately, this study aims to generate strategies to support methods instructors in their efforts to…

  12. Enhanced propagation modeling of directional aviation noise: A hybrid parabolic equation-fast field program method

    NASA Astrophysics Data System (ADS)

    Rosenbaum, Joyce E.

    2011-12-01

    Commercial air traffic is anticipated to increase rapidly in the coming years. The impact of aviation noise on communities surrounding airports is, therefore, a growing concern. Accurate prediction of noise can help to mitigate the impact on communities and foster smoother integration of aerospace engineering advances. The problem of accurate sound level prediction requires careful inclusion of all mechanisms that affect propagation, in addition to correct source characterization. Terrain, ground type, meteorological effects, and source directivity can have a substantial influence on the noise level. Because they are difficult to model, these effects are often included only by rough approximation. This dissertation presents a model designed for sound propagation over uneven terrain, with mixed ground type and realistic meteorological conditions. The model is a hybrid of two numerical techniques: the parabolic equation (PE) and fast field program (FFP) methods, which allow for physics-based inclusion of propagation effects and ensure the low frequency content, a factor in community impact, is predicted accurately. Extension of the hybrid model to a pseudo-three-dimensional representation allows it to produce aviation noise contour maps in the standard form. In order for the model to correctly characterize aviation noise sources, a method of representing arbitrary source directivity patterns was developed for the unique form of the parabolic equation starting field. With this advancement, the model can represent broadband, directional moving sound sources, traveling along user-specified paths. This work was prepared for possible use in the research version of the sound propagation module in the Federal Aviation Administration's new standard predictive tool.

  13. ADVANCING THE STUDY OF VIOLENCE AGAINST WOMEN USING MIXED METHODS: INTEGRATING QUALITATIVE METHODS INTO A QUANTITATIVE RESEARCH PROGRAM

    PubMed Central

    Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol

    2011-01-01

    A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032

  14. Visualizing Volume to Help Students Understand the Disk Method on Calculus Integral Course

    NASA Astrophysics Data System (ADS)

    Tasman, F.; Ahmad, D.

    2018-04-01

    Many research shown that students have difficulty in understanding the concepts of integral calculus. Therefore this research is interested in designing a classroom activity integrated with design research method to assist students in understanding the integrals concept especially in calculating the volume of rotary objects using disc method. In order to support student development in understanding integral concepts, this research tries to use realistic mathematical approach by integrating geogebra software. First year university student who takes a calculus course (approximately 30 people) was chosen to implement the classroom activity that has been designed. The results of retrospective analysis show that visualizing volume of rotary objects using geogebra software can assist the student in understanding the disc method as one way of calculating the volume of a rotary object.

  15. Scalable direct Vlasov solver with discontinuous Galerkin method on unstructured mesh.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, J.; Ostroumov, P. N.; Mustapha, B.

    2010-12-01

    This paper presents the development of parallel direct Vlasov solvers with discontinuous Galerkin (DG) method for beam and plasma simulations in four dimensions. Both physical and velocity spaces are in two dimesions (2P2V) with unstructured mesh. Contrary to the standard particle-in-cell (PIC) approach for kinetic space plasma simulations, i.e., solving Vlasov-Maxwell equations, direct method has been used in this paper. There are several benefits to solving a Vlasov equation directly, such as avoiding noise associated with a finite number of particles and the capability to capture fine structure in the plasma. The most challanging part of a direct Vlasov solvermore » comes from higher dimensions, as the computational cost increases as N{sup 2d}, where d is the dimension of the physical space. Recently, due to the fast development of supercomputers, the possibility has become more realistic. Many efforts have been made to solve Vlasov equations in low dimensions before; now more interest has focused on higher dimensions. Different numerical methods have been tried so far, such as the finite difference method, Fourier Spectral method, finite volume method, and spectral element method. This paper is based on our previous efforts to use the DG method. The DG method has been proven to be very successful in solving Maxwell equations, and this paper is our first effort in applying the DG method to Vlasov equations. DG has shown several advantages, such as local mass matrix, strong stability, and easy parallelization. These are particularly suitable for Vlasov equations. Domain decomposition in high dimensions has been used for parallelization; these include a highly scalable parallel two-dimensional Poisson solver. Benchmark results have been shown and simulation results will be reported.« less

  16. Method for directional hydraulic fracturing

    DOEpatents

    Swanson, David E.; Daly, Daniel W.

    1994-01-01

    A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

  17. A direct method for nonlinear ill-posed problems

    NASA Astrophysics Data System (ADS)

    Lakhal, A.

    2018-02-01

    We propose a direct method for solving nonlinear ill-posed problems in Banach-spaces. The method is based on a stable inversion formula we explicitly compute by applying techniques for analytic functions. Furthermore, we investigate the convergence and stability of the method and prove that the derived noniterative algorithm is a regularization. The inversion formula provides a systematic sensitivity analysis. The approach is applicable to a wide range of nonlinear ill-posed problems. We test the algorithm on a nonlinear problem of travel-time inversion in seismic tomography. Numerical results illustrate the robustness and efficiency of the algorithm.

  18. Integrated Site Investigation Methods and Modeling: Recent Developments at the BHRS (Invited)

    NASA Astrophysics Data System (ADS)

    Barrash, W.; Bradford, J. H.; Cardiff, M. A.; Dafflon, B.; Johnson, B. A.; Malama, B.; Thoma, M. J.

    2010-12-01

    The Boise Hydrogeophysical Research Site (BHRS) is a field-scale test facility in an unconfined aquifer with the goals of: developing cost-effective, non-invasive methods for quantitative characterization of heterogeneous aquifers using hydrologic and geophysical techniques; understanding fundamental relations and processes at multiple scales; and testing theories and models for groundwater flow and solute transport. The design of the BHRS supports a wide range of single-well, cross-hole, multiwell and multilevel hydrologic, geophysical, and combined hydrogeophysical experiments. New installations support direct and geophysical monitoring of hydrologic fluxes and states from the aquifer through the vadose zone to the atmosphere, including ET and river boundary behavior. Efforts to date have largely focused on establishing the 1D, 2D, and 3D distributions of geologic, hydrologic, and geophysical parameters which can then be used as the basis for testing methods to integrate direct and indirect data and invert for “known” parameter distributions, material boundaries, and tracer test or other system state behavior. Aquifer structure at the BHRS is hierarchical and includes layers and lenses that are recognized with geologic, hydrologic, radar, electrical, and seismic methods. Recent advances extend findings and method developments, but also highlight the need to examine assumptions and understand secular influences when designing and modeling field tests. Examples of advances and caveats include: New high-resolution 1D K profiles obtained from multi-level slug tests (inversion improves with priors for aquifer K, wellbore skin, and local presence of roots) show variable correlation with porosity and bring into question a Kozeny-Carman-type relation for much of the system. Modeling of 2D conservative tracer transport through a synthetic BHRS-like heterogeneous system shows the importance of including porosity heterogeneity (rather than assuming constant porosity for

  19. Integration of offshore wind farms through high voltage direct current networks

    NASA Astrophysics Data System (ADS)

    Livermore, Luke

    The integration of offshore wind farms through Multi Terminal DC (MTDC) networks into the GB network was investigated. The ability of Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) to damp Subsynchronous Resonance (SSR) and ride through onshore AC faults was studied. Due to increased levels of wind generation in Scotland, substantial onshore and offshore reinforcements to the GB transmission network are proposed. Possible inland reinforcements include the use of series compensation through fixed capacitors. This potentially can lead to SSR. Offshore reinforcements are proposed by two HVDC links. In addition to its primary functions of bulk power transmission, a HVDC link can be used to provide damping against SSR, and this function has been modelled. Simulation studies have been carried out in PSCAD. In addition, a real-time hardware-in-the-loop HVDC test rig has been used to implement and validate the proposed damping scheme on an experimental platform. When faults occur within AC onshore networks, offshore MTDC networks are vulnerable to DC overvoltages, potentially damaging the DC plant and cables. Power reduction and power dissipation control systems were investigated to ride through onshore AC faults. These methods do not require dedicated fast communication systems. Simulations and laboratory experiments are carried out to evaluate the control systems, with the results from the two platforms compared..

  20. A method for the direct numerical simulation of hypersonic boundary-layer instability with finite-rate chemistry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Marxen, Olaf, E-mail: olaf.marxen@vki.ac.be; Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse; Magin, Thierry E.

    2013-12-15

    A new numerical method is presented here that allows to consider chemically reacting gases during the direct numerical simulation of a hypersonic fluid flow. The method comprises the direct coupling of a solver for the fluid mechanical model and a library providing the physio-chemical model. The numerical method for the fluid mechanical model integrates the compressible Navier–Stokes equations using an explicit time advancement scheme and high-order finite differences. This Navier–Stokes code can be applied to the investigation of laminar-turbulent transition and boundary-layer instability. The numerical method for the physio-chemical model provides thermodynamic and transport properties for different gases as wellmore » as chemical production rates, while here we exclusively consider a five species air mixture. The new method is verified for a number of test cases at Mach 10, including the one-dimensional high-temperature flow downstream of a normal shock, a hypersonic chemical reacting boundary layer in local thermodynamic equilibrium and a hypersonic reacting boundary layer with finite-rate chemistry. We are able to confirm that the diffusion flux plays an important role for a high-temperature boundary layer in local thermodynamic equilibrium. Moreover, we demonstrate that the flow for a case previously considered as a benchmark for the investigation of non-equilibrium chemistry can be regarded as frozen. Finally, the new method is applied to investigate the effect of finite-rate chemistry on boundary layer instability by considering the downstream evolution of a small-amplitude wave and comparing results with those obtained for a frozen gas as well as a gas in local thermodynamic equilibrium.« less

  1. Laser housing having integral mounts and method of manufacturing same

    DOEpatents

    Herron, Michael Alan; Brickeen, Brian Keith

    2004-10-19

    A housing adapted to position, support, and facilitate aligning various components, including an optical path assembly, of a laser. In a preferred embodiment, the housing is constructed from a single piece of material and broadly comprises one or more through-holes; one or more cavities; and one or more integral mounts, wherein the through-holes and the cavities cooperate to define the integral mounts. Securement holes machined into the integral mounts facilitate securing components within the integral mounts using set screws, adhesive, or a combination thereof. In a preferred method of making the housing, the through-holes and cavities are first machined into the single piece of material, with at least some of the remaining material forming the integral mounts.

  2. Noninvasive computerized scanning method for the correlation between the facial soft and hard tissues for an integrated three-dimensional anthropometry and cephalometry.

    PubMed

    Galantucci, Luigi Maria; Percoco, Gianluca; Lavecchia, Fulvio; Di Gioia, Eliana

    2013-05-01

    The article describes a new methodology to scan and integrate facial soft tissue surface with dental hard tissue models in a three-dimensional (3D) virtual environment, for a novel diagnostic approach.The facial and the dental scans can be acquired using any optical scanning systems: the models are then aligned and integrated to obtain a full virtual navigable representation of the head of the patient. In this article, we report in detail and further implemented a method for integrating 3D digital cast models into a 3D facial image, to visualize the anatomic position of the dentition. This system uses several 3D technologies to scan and digitize, integrating them with traditional dentistry records. The acquisitions were mainly performed using photogrammetric scanners, suitable for clinics or hospitals, able to obtain high mesh resolution and optimal surface texture for the photorealistic rendering of the face. To increase the quality and the resolution of the photogrammetric scanning of the dental elements, the authors propose a new technique to enhance the texture of the dental surface. Three examples of the application of the proposed procedure are reported in this article, using first laser scanning and photogrammetry and then only photogrammetry. Using cheek retractors, it is possible to scan directly a great number of dental elements. The final results are good navigable 3D models that integrate facial soft tissue and dental hard tissues. The method is characterized by the complete absence of ionizing radiation, portability and simplicity, fast acquisition, easy alignment of the 3D models, and wide angle of view of the scanner. This method is completely noninvasive and can be repeated any time the physician needs new clinical records. The 3D virtual model is a precise representation both of the soft and the hard tissue scanned, and it is possible to make any dimensional measure directly in the virtual space, for a full integrated 3D anthropometry and

  3. A COMPARISON OF TRANSIENT INFINITE ELEMENTS AND TRANSIENT KIRCHHOFF INTEGRAL METHODS FOR FAR FIELD ACOUSTIC ANALYSIS

    DOE PAGES

    WALSH, TIMOTHY F.; JONES, ANDREA; BHARDWAJ, MANOJ; ...

    2013-04-01

    Finite element analysis of transient acoustic phenomena on unbounded exterior domains is very common in engineering analysis. In these problems there is a common need to compute the acoustic pressure at points outside of the acoustic mesh, since meshing to points of interest is impractical in many scenarios. In aeroacoustic calculations, for example, the acoustic pressure may be required at tens or hundreds of meters from the structure. In these cases, a method is needed for post-processing the acoustic results to compute the response at far-field points. In this paper, we compare two methods for computing far-field acoustic pressures, onemore » derived directly from the infinite element solution, and the other from the transient version of the Kirchhoff integral. Here, we show that the infinite element approach alleviates the large storage requirements that are typical of Kirchhoff integral and related procedures, and also does not suffer from loss of accuracy that is an inherent part of computing numerical derivatives in the Kirchhoff integral. In order to further speed up and streamline the process of computing the acoustic response at points outside of the mesh, we also address the nonlinear iterative procedure needed for locating parametric coordinates within the host infinite element of far-field points, the parallelization of the overall process, linear solver requirements, and system stability considerations.« less

  4. Future directions: Integrated resource planning

    NASA Astrophysics Data System (ADS)

    Bauer, D. C.; Eto, J.

    Integrated resource planning or IRP is the process for integrating supply- and demand-side resources to provide energy services at a cost that balances the interests of all stakeholders. It now is the resource planning process used by electric utilities in over 30 states. The goals of IRP have evolved from least cost planning and encouragement of demand-side management to broader, more complex issues including core competitive business activity, risk management and sharing, accounting for externalities, and fuel switching between gas and electricity. IRP processes are being extended to other interior regions of the country, to non-investor owned utilities, and to regional (rather than individual utility) planning bases, and to other fuels (natural gas). The comprehensive, multi-valued, and public reasoning characteristics of IRP could be extended to applications beyond energy, e.g., transportation, surface water management, and health care in ways suggested.

  5. Multi-off-grid methods in multi-step integration of ordinary differential equations

    NASA Technical Reports Server (NTRS)

    Beaudet, P. R.

    1974-01-01

    Description of methods of solving first- and second-order systems of differential equations in which all derivatives are evaluated at off-grid locations in order to circumvent the Dahlquist stability limitation on the order of on-grid methods. The proposed multi-off-grid methods require off-grid state predictors for the evaluation of the n derivatives at each step. Progressing forward in time, the off-grid states are predicted using a linear combination of back on-grid state values and off-grid derivative evaluations. A comparison is made between the proposed multi-off-grid methods and the corresponding Adams and Cowell on-grid integration techniques in integrating systems of ordinary differential equations, showing a significant reduction in the error at larger step sizes in the case of the multi-off-grid integrator.

  6. An equivalent domain integral method in the two-dimensional analysis of mixed mode crack problems

    NASA Technical Reports Server (NTRS)

    Raju, I. S.; Shivakumar, K. N.

    1990-01-01

    An equivalent domain integral (EDI) method for calculating J-integrals for two-dimensional cracked elastic bodies is presented. The details of the method and its implementation are presented for isoparametric elements. The EDI method gave accurate values of the J-integrals for two mode I and two mixed mode problems. Numerical studies showed that domains consisting of one layer of elements are sufficient to obtain accurate J-integral values. Two procedures for separating the individual modes from the domain integrals are presented.

  7. Methods of integrating Islamic values in teaching biology for shaping attitude and character

    NASA Astrophysics Data System (ADS)

    Listyono; Supardi, K. I.; Hindarto, N.; Ridlo, S.

    2018-03-01

    Learning is expected to develop the potential of learners to have the spiritual attitude: moral strength, self-control, personality, intelligence, noble character, as well as the skills needed by themselves, society, and nation. Implementation of role and morale in learning is an alternative way which is expected to answer the challenge. The solution offered is to inject student with religious material Islamic in learning biology. The content value of materials teaching biology includes terms of practical value, religious values, daily life value, socio-political value, and the value of art. In Islamic religious values (Qur'an and Hadith) various methods can touch human feelings, souls, and generate motivation. Integrating learning with Islamic value can be done by the deductive or inductive approach. The appropriate method of integration is the amtsal (analog) method, hiwar (dialog) method, targhib & tarhib (encouragement & warning) method, and example method (giving a noble role model / good example). The right strategy in integrating Islamic values is outlined in the design of lesson plan. The integration of Islamic values in lesson plan will facilitate teachers to build students' character because Islamic values can be implemented in every learning steps so students will be accustomed to receiving the character value in this integrated learning.

  8. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  9. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1998-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  10. Application of Patterson-function direct methods to materials characterization.

    PubMed

    Rius, Jordi

    2014-09-01

    The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM), from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data.

  11. Direct current uninterruptible power supply method and system

    DOEpatents

    Sinha, Gautam

    2003-12-02

    A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

  12. Generalizing Gillespie’s Direct Method to Enable Network-Free Simulations

    DOE PAGES

    Suderman, Ryan T.; Mitra, Eshan David; Lin, Yen Ting; ...

    2018-03-28

    Gillespie’s direct method for stochastic simulation of chemical kinetics is a staple of computational systems biology research. However, the algorithm requires explicit enumeration of all reactions and all chemical species that may arise in the system. In many cases, this is not feasible due to the combinatorial explosion of reactions and species in biological networks. Rule-based modeling frameworks provide a way to exactly represent networks containing such combinatorial complexity, and generalizations of Gillespie’s direct method have been developed as simulation engines for rule-based modeling languages. Here, we provide both a high-level description of the algorithms underlying the simulation engines, termedmore » network-free simulation algorithms, and how they have been applied in systems biology research. We also define a generic rule-based modeling framework and describe a number of technical details required for adapting Gillespie’s direct method for network-free simulation. Lastly, we briefly discuss potential avenues for advancing network-free simulation and the role they continue to play in modeling dynamical systems in biology.« less

  13. Generalizing Gillespie’s Direct Method to Enable Network-Free Simulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suderman, Ryan T.; Mitra, Eshan David; Lin, Yen Ting

    Gillespie’s direct method for stochastic simulation of chemical kinetics is a staple of computational systems biology research. However, the algorithm requires explicit enumeration of all reactions and all chemical species that may arise in the system. In many cases, this is not feasible due to the combinatorial explosion of reactions and species in biological networks. Rule-based modeling frameworks provide a way to exactly represent networks containing such combinatorial complexity, and generalizations of Gillespie’s direct method have been developed as simulation engines for rule-based modeling languages. Here, we provide both a high-level description of the algorithms underlying the simulation engines, termedmore » network-free simulation algorithms, and how they have been applied in systems biology research. We also define a generic rule-based modeling framework and describe a number of technical details required for adapting Gillespie’s direct method for network-free simulation. Lastly, we briefly discuss potential avenues for advancing network-free simulation and the role they continue to play in modeling dynamical systems in biology.« less

  14. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

    PubMed Central

    Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

    2015-01-01

    PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

  15. An improved principal component analysis based region matching method for fringe direction estimation

    NASA Astrophysics Data System (ADS)

    He, A.; Quan, C.

    2018-04-01

    The principal component analysis (PCA) and region matching combined method is effective for fringe direction estimation. However, its mask construction algorithm for region matching fails in some circumstances, and the algorithm for conversion of orientation to direction in mask areas is computationally-heavy and non-optimized. We propose an improved PCA based region matching method for the fringe direction estimation, which includes an improved and robust mask construction scheme, and a fast and optimized orientation-direction conversion algorithm for the mask areas. Along with the estimated fringe direction map, filtered fringe pattern by automatic selective reconstruction modification and enhanced fast empirical mode decomposition (ASRm-EFEMD) is used for Hilbert spiral transform (HST) to demodulate the phase. Subsequently, windowed Fourier ridge (WFR) method is used for the refinement of the phase. The robustness and effectiveness of proposed method are demonstrated by both simulated and experimental fringe patterns.

  16. One Solution of the Forward Problem of DC Resistivity Well Logging by the Method of Volume Integral Equations with Allowance for Induced Polarization

    NASA Astrophysics Data System (ADS)

    Kevorkyants, S. S.

    2018-03-01

    For theoretically studying the intensity of the influence exerted by the polarization of the rocks on the results of direct current (DC) well logging, a solution is suggested for the direct inner problem of the DC electric logging in the polarizable model of plane-layered medium containing a heterogeneity by the example of the three-layer model of the hosting medium. Initially, the solution is presented in the form of a traditional vector volume-integral equation of the second kind (IE2) for the electric current density vector. The vector IE2 is solved by the modified iteration-dissipation method. By the transformations, the initial IE2 is reduced to the equation with the contraction integral operator for an axisymmetric model of electrical well-logging of the three-layer polarizable medium intersected by an infinitely long circular cylinder. The latter simulates the borehole with a zone of penetration where the sought vector consists of the radial J r and J z axial (relative to the cylinder's axis) components. The decomposition of the obtained vector IE2 into scalar components and the discretization in the coordinates r and z lead to a heterogeneous system of linear algebraic equations with a block matrix of the coefficients representing 2x2 matrices whose elements are the triple integrals of the mixed derivatives of the second-order Green's function with respect to the parameters r, z, r', and z'. With the use of the analytical transformations and standard integrals, the integrals over the areas of the partition cells and azimuthal coordinate are reduced to single integrals (with respect to the variable t = cos ϕ on the interval [-1, 1]) calculated by the Gauss method for numerical integration. For estimating the effective coefficient of polarization of the complex medium, it is suggested to use the Siegel-Komarov formula.

  17. Method and system of integrating information from multiple sources

    DOEpatents

    Alford, Francine A [Livermore, CA; Brinkerhoff, David L [Antioch, CA

    2006-08-15

    A system and method of integrating information from multiple sources in a document centric application system. A plurality of application systems are connected through an object request broker to a central repository. The information may then be posted on a webpage. An example of an implementation of the method and system is an online procurement system.

  18. An integrated teaching method of gross anatomy and computed tomography radiology.

    PubMed

    Murakami, Tohru; Tajika, Yuki; Ueno, Hitoshi; Awata, Sachiko; Hirasawa, Satoshi; Sugimoto, Maki; Kominato, Yoshihiko; Tsushima, Yoshito; Endo, Keigo; Yorifuji, Hiroshi

    2014-01-01

    It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench-side (OsiriX on iPod touch or iPad), which enabled "pixel-to-tissue" direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses. © 2014 American Association of Anatomists.

  19. Multistep Methods for Integrating the Solar System

    DTIC Science & Technology

    1988-07-01

    Technical Report 1055 [Multistep Methods for Integrating the Solar System 0 Panayotis A. Skordos’ MIT Artificial Intelligence Laboratory DTIC S D g8...RMA ELEENT. PROECT. TASK Artific ial Inteligence Laboratory ARE1A G WORK UNIT NUMBERS 545 Technology Square Cambridge, MA 02139 IL. CONTROLLING...describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology, supported by the Advanced Research Projects

  20. Integrating computational methods to retrofit enzymes to synthetic pathways.

    PubMed

    Brunk, Elizabeth; Neri, Marilisa; Tavernelli, Ivano; Hatzimanikatis, Vassily; Rothlisberger, Ursula

    2012-02-01

    Microbial production of desired compounds provides an efficient framework for the development of renewable energy resources. To be competitive to traditional chemistry, one requirement is to utilize the full capacity of the microorganism to produce target compounds with high yields and turnover rates. We use integrated computational methods to generate and quantify the performance of novel biosynthetic routes that contain highly optimized catalysts. Engineering a novel reaction pathway entails addressing feasibility on multiple levels, which involves handling the complexity of large-scale biochemical networks while respecting the critical chemical phenomena at the atomistic scale. To pursue this multi-layer challenge, our strategy merges knowledge-based metabolic engineering methods with computational chemistry methods. By bridging multiple disciplines, we provide an integral computational framework that could accelerate the discovery and implementation of novel biosynthetic production routes. Using this approach, we have identified and optimized a novel biosynthetic route for the production of 3HP from pyruvate. Copyright © 2011 Wiley Periodicals, Inc.

  1. Implementation of equivalent domain integral method in the two-dimensional analysis of mixed mode problems

    NASA Technical Reports Server (NTRS)

    Raju, I. S.; Shivakumar, K. N.

    1989-01-01

    An equivalent domain integral (EDI) method for calculating J-intergrals for two-dimensional cracked elastic bodies is presented. The details of the method and its implementation are presented for isoparametric elements. The total and product integrals consist of the sum of an area of domain integral and line integrals on the crack faces. The line integrals vanish only when the crack faces are traction free and the loading is either pure mode 1 or pure mode 2 or a combination of both with only the square-root singular term in the stress field. The EDI method gave accurate values of the J-integrals for two mode I and two mixed mode problems. Numerical studies showed that domains consisting of one layer of elements are sufficient to obtain accurate J-integral values. Two procedures for separating the individual modes from the domain integrals are presented. The procedure that uses the symmetric and antisymmetric components of the stress and displacement fields to calculate the individual modes gave accurate values of the integrals for all problems analyzed. The EDI method when applied to a problem of an interface crack in two different materials showed that the mode 1 and mode 2 components are domain dependent while the total integral is not. This behavior is caused by the presence of the oscillatory part of the singularity in bimaterial crack problems. The EDI method, thus, shows behavior similar to the virtual crack closure method for bimaterial problems.

  2. A new fast direct solver for the boundary element method

    NASA Astrophysics Data System (ADS)

    Huang, S.; Liu, Y. J.

    2017-09-01

    A new fast direct linear equation solver for the boundary element method (BEM) is presented in this paper. The idea of the new fast direct solver stems from the concept of the hierarchical off-diagonal low-rank matrix. The hierarchical off-diagonal low-rank matrix can be decomposed into the multiplication of several diagonal block matrices. The inverse of the hierarchical off-diagonal low-rank matrix can be calculated efficiently with the Sherman-Morrison-Woodbury formula. In this paper, a more general and efficient approach to approximate the coefficient matrix of the BEM with the hierarchical off-diagonal low-rank matrix is proposed. Compared to the current fast direct solver based on the hierarchical off-diagonal low-rank matrix, the proposed method is suitable for solving general 3-D boundary element models. Several numerical examples of 3-D potential problems with the total number of unknowns up to above 200,000 are presented. The results show that the new fast direct solver can be applied to solve large 3-D BEM models accurately and with better efficiency compared with the conventional BEM.

  3. On the reliability and limitations of the SPAC method with a directional wavefield

    NASA Astrophysics Data System (ADS)

    Luo, Song; Luo, Yinhe; Zhu, Lupei; Xu, Yixian

    2016-03-01

    The spatial autocorrelation (SPAC) method is one of the most efficient ways to extract phase velocities of surface waves from ambient seismic noise. Most studies apply the method based on the assumption that the wavefield of ambient noise is diffuse. However, the actual distribution of sources is neither diffuse nor stationary. In this study, we examined the reliability and limitations of the SPAC method with a directional wavefield. We calculated the SPAC coefficients and phase velocities from a directional wavefield for a four-layer model and characterized the limitations of the SPAC. We then applied the SPAC method to real data in Karamay, China. Our results show that, 1) the SPAC method can accurately measure surface wave phase velocities from a square array with a directional wavefield down to a wavelength of twice the shortest interstation distance; and 2) phase velocities obtained from real data by the SPAC method are stable and reliable, which demonstrates that this method can be applied to measure phase velocities in a square array with a directional wavefield.

  4. A photoacoustic imaging reconstruction method based on directional total variation with adaptive directivity.

    PubMed

    Wang, Jin; Zhang, Chen; Wang, Yuanyuan

    2017-05-30

    In photoacoustic tomography (PAT), total variation (TV) based iteration algorithm is reported to have a good performance in PAT image reconstruction. However, classical TV based algorithm fails to preserve the edges and texture details of the image because it is not sensitive to the direction of the image. Therefore, it is of great significance to develop a new PAT reconstruction algorithm to effectively solve the drawback of TV. In this paper, a directional total variation with adaptive directivity (DDTV) model-based PAT image reconstruction algorithm, which weightedly sums the image gradients based on the spatially varying directivity pattern of the image is proposed to overcome the shortcomings of TV. The orientation field of the image is adaptively estimated through a gradient-based approach. The image gradients are weighted at every pixel based on both its anisotropic direction and another parameter, which evaluates the estimated orientation field reliability. An efficient algorithm is derived to solve the iteration problem associated with DDTV and possessing directivity of the image adaptively updated for each iteration step. Several texture images with various directivity patterns are chosen as the phantoms for the numerical simulations. The 180-, 90- and 30-view circular scans are conducted. Results obtained show that the DDTV-based PAT reconstructed algorithm outperforms the filtered back-projection method (FBP) and TV algorithms in the quality of reconstructed images with the peak signal-to-noise rations (PSNR) exceeding those of TV and FBP by about 10 and 18 dB, respectively, for all cases. The Shepp-Logan phantom is studied with further discussion of multimode scanning, convergence speed, robustness and universality aspects. In-vitro experiments are performed for both the sparse-view circular scanning and linear scanning. The results further prove the effectiveness of the DDTV, which shows better results than that of the TV with sharper image edges and

  5. Towards a taxonomy for integrated care: a mixed-methods study.

    PubMed

    Valentijn, Pim P; Boesveld, Inge C; van der Klauw, Denise M; Ruwaard, Dirk; Struijs, Jeroen N; Molema, Johanna J W; Bruijnzeels, Marc A; Vrijhoef, Hubertus Jm

    2015-01-01

    Building integrated services in a primary care setting is considered an essential important strategy for establishing a high-quality and affordable health care system. The theoretical foundations of such integrated service models are described by the Rainbow Model of Integrated Care, which distinguishes six integration dimensions (clinical, professional, organisational, system, functional and normative integration). The aim of the present study is to refine the Rainbow Model of Integrated Care by developing a taxonomy that specifies the underlying key features of the six dimensions. First, a literature review was conducted to identify features for achieving integrated service delivery. Second, a thematic analysis method was used to develop a taxonomy of key features organised into the dimensions of the Rainbow Model of Integrated Care. Finally, the appropriateness of the key features was tested in a Delphi study among Dutch experts. The taxonomy consists of 59 key features distributed across the six integration dimensions of the Rainbow Model of Integrated Care. Key features associated with the clinical, professional, organisational and normative dimensions were considered appropriate by the experts. Key features linked to the functional and system dimensions were considered less appropriate. This study contributes to the ongoing debate of defining the concept and typology of integrated care. This taxonomy provides a development agenda for establishing an accepted scientific framework of integrated care from an end-user, professional, managerial and policy perspective.

  6. Evaluation of two methods for direct detection of Fusarium spp. in water.

    PubMed

    Graça, Mariana G; van der Heijden, Inneke M; Perdigão, Lauro; Taira, Cleison; Costa, Silvia F; Levin, Anna S

    2016-04-01

    Fusarium is a waterborne fungus that causes severe infections especially in patients with prolonged neutropenia. Traditionally, the detection of Fusarium in water is done by culturing which is difficult and time consuming. A faster method is necessary to prevent exposure of susceptible patients to contaminated water. The objective of this study was to develop a molecular technique for direct detection of Fusarium in water. A direct DNA extraction method from water was developed and coupled to a genus-specific PCR, to detect 3 species of Fusarium (verticillioides, oxysporum and solani). The detection limits were 10 cells/L and 1 cell/L for the molecular and culture methods, respectively. To our knowledge, this is the first method developed to detect Fusarium directly from water. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Evaluation of direct saponification method for determination of cholesterol in meats.

    PubMed

    Adams, M L; Sullivan, D M; Smith, R L; Richter, E F

    1986-01-01

    A gas chromatographic (GC) method has been developed for determination of cholesterol in meats. The method involves ethanolic KOH saponification of the sample material, homogeneous-phase toluene extraction of the unsaponifiables, derivatization of cholesterol to its trimethylsilylether, and quantitation by GC-flame ionization detection using 5-alpha-cholestane as internal standard. This direct saponification method is compared with the current AOAC official method for determination of cholesterol in 20 different meat products. The direct saponification method eliminates the need for initial lipid extraction, thus offering a 30% savings in labor, and requires fewer solvents than the AOAC method. It produced comparable or slightly higher cholesterol results than the AOAC method in all meat samples examined. Precision, determined by assaying a turkey meat sample 16 times over 4 days, was excellent (CV = 1.74%). Average recovery of cholesterol added to meat samples was 99.8%.

  8. Multisensor satellite data integration for sea surface wind speed and direction determination

    NASA Technical Reports Server (NTRS)

    Glackin, D. L.; Pihos, G. G.; Wheelock, S. L.

    1984-01-01

    Techniques to integrate meteorological data from various satellite sensors to yield a global measure of sea surface wind speed and direction for input to the Navy's operational weather forecast models were investigated. The sensors were launched or will be launched, specifically the GOES visible and infrared imaging sensor, the Nimbus-7 SMMR, and the DMSP SSM/I instrument. An algorithm for the extrapolation to the sea surface of wind directions as derived from successive GOES cloud images was developed. This wind veering algorithm is relatively simple, accounts for the major physical variables, and seems to represent the best solution that can be found with existing data. An algorithm for the interpolation of the scattered observed data to a common geographical grid was implemented. The algorithm is based on a combination of inverse distance weighting and trend surface fitting, and is suited to combing wind data from disparate sources.

  9. METHODS FOR DETERMINING THE MECHANICAL INTEGRITY OF CLASS II INJECTION WELLS

    EPA Science Inventory

    The mechanical integrity of injection wells must be determined to insure that there is no significant leak in the casing, tubing or packer, and that there is no significant fluid movement through vertical channels adjacent to the injection well. Methods for mechanical integrity t...

  10. Modulating Motor Learning through Transcranial Direct-Current Stimulation: An Integrative View

    PubMed Central

    Ammann, Claudia; Spampinato, Danny; Márquez-Ruiz, Javier

    2016-01-01

    Motor learning consists of the ability to improve motor actions through practice playing a major role in the acquisition of skills required for high-performance sports or motor function recovery after brain lesions. During the last decades, it has been reported that transcranial direct-current stimulation (tDCS), consisting in applying weak direct current through the scalp, is able of inducing polarity-specific changes in the excitability of cortical neurons. This low-cost, painless and well-tolerated portable technique has found a wide-spread use in the motor learning domain where it has been successfully applied to enhance motor learning in healthy individuals and for motor recovery after brain lesion as well as in pathological states associated to motor deficits. The main objective of this mini-review is to offer an integrative view about the potential use of tDCS for human motor learning modulation. Furthermore, we introduce the basic mechanisms underlying immediate and long-term effects associated to tDCS along with important considerations about its limitations and progression in recent years. PMID:28066300

  11. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays.

    PubMed

    Guetterman, Timothy C; Fetters, Michael D; Creswell, John W

    2015-11-01

    Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. © 2015 Annals of Family Medicine, Inc.

  12. Method and apparatus for in-system redundant array repair on integrated circuits

    DOEpatents

    Bright, Arthur A [Croton-on-Hudson, NY; Crumley, Paul G [Yorktown Heights, NY; Dombrowa, Marc B [Bronx, NY; Douskey, Steven M [Rochester, MN; Haring, Rudolf A [Cortlandt Manor, NY; Oakland, Steven F [Colchester, VT; Ouellette, Michael R [Westford, VT; Strissel, Scott A [Byron, MN

    2008-07-29

    Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  13. Method and apparatus for in-system redundant array repair on integrated circuits

    DOEpatents

    Bright, Arthur A [Croton-on-Hudson, NY; Crumley, Paul G [Yorktown Heights, NY; Dombrowa, Marc B [Bronx, NY; Douskey, Steven M [Rochester, MN; Haring, Rudolf A [Cortlandt Manor, NY; Oakland, Steven F [Colchester, VT; Ouellette, Michael R [Westford, VT; Strissel, Scott A [Byron, MN

    2008-07-08

    Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  14. Method and apparatus for in-system redundant array repair on integrated circuits

    DOEpatents

    Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc B.; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Ouellette, Michael R.; Strissel, Scott A.

    2007-12-18

    Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  15. A Direct and Rapid Method to Determine Cyanide in Urine by Capillary Electrophoresis

    PubMed Central

    Zhang, Qiyang; Maddukuri, Naveen; Gong, Maojun

    2015-01-01

    Cyanides are poisonous chemicals that widely exist in nature and industrial processes as well as accidental fires. Rapid and accurate determination of cyanide exposure would facilitate forensic investigation, medical diagnosis, and chronic cyanide monitoring. Here, a rapid and direct method was developed for the determination of cyanide ions in urinary samples. This technique was based on an integrated capillary electrophoresis system coupled with laser-induced fluorescence (LIF) detection. Cyanide ions were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) and a primary amine (glycine) for LIF detection. Three separate reagents, NDA, glycine, and cyanide sample, were mixed online, which secured uniform conditions between samples for cyanide derivatization and reduced the risk of precipitation formation of mixtures. Conditions were optimized; the derivatization was completed in 2-4 minutes, and the separation was observed in 25 s. The limit of detection (LOD) was 4.0 nM at 3-fold signal-to-noise ratio for standard cyanide in buffer. The cyanide levels in urine samples from smokers and non-smokers were determined by using the method of standard addition, which demonstrated significant difference of cyanide levels in urinary samples from the two groups of people. The developed method was rapid and accurate, and is anticipated to be applicable to cyanide detection in waste water with appropriate modification. PMID:26342870

  16. A direct and rapid method to determine cyanide in urine by capillary electrophoresis.

    PubMed

    Zhang, Qiyang; Maddukuri, Naveen; Gong, Maojun

    2015-10-02

    Cyanides are poisonous chemicals that widely exist in nature and industrial processes as well as accidental fires. Rapid and accurate determination of cyanide exposure would facilitate forensic investigation, medical diagnosis, and chronic cyanide monitoring. Here, a rapid and direct method was developed for the determination of cyanide ions in urinary samples. This technique was based on an integrated capillary electrophoresis system coupled with laser-induced fluorescence (LIF) detection. Cyanide ions were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) and a primary amine (glycine) for LIF detection. Three separate reagents, NDA, glycine, and cyanide sample, were mixed online, which secured uniform conditions between samples for cyanide derivatization and reduced the risk of precipitation formation of mixtures. Conditions were optimized; the derivatization was completed in 2-4min, and the separation was observed in 25s. The limit of detection (LOD) was 4.0nM at 3-fold signal-to-noise ratio for standard cyanide in buffer. The cyanide levels in urine samples from smokers and non-smokers were determined by using the method of standard addition, which demonstrated significant difference of cyanide levels in urinary samples from the two groups of people. The developed method was rapid and accurate, and is anticipated to be applicable to cyanide detection in waste water with appropriate modification. Published by Elsevier B.V.

  17. Direct-laser metal writing of surface acoustic wave transducers for integrated-optic spatial light modulators in lithium niobate

    NASA Astrophysics Data System (ADS)

    Datta, Bianca C.; Savidis, Nickolaos; Moebius, Michael; Jolly, Sundeep; Mazur, Eric; Bove, V. Michael

    2017-02-01

    Recently, the fabrication of high-resolution silver nanostructures using a femtosecond laser-based direct write process in a gelatin matrix was reported. The application of direct metal writing towards feature development has also been explored with direct metal fusion, in which metal is fused onto the surface of the substrate via a femtosecond laser process. In this paper, we present a comparative study of gelatin matrix and metal fusion approaches for directly laser-written fabrication of surface acoustic wave transducers on a lithium niobate substrate for application in integrated optic spatial light modulators.

  18. A Kernel-free Boundary Integral Method for Elliptic Boundary Value Problems ⋆

    PubMed Central

    Ying, Wenjun; Henriquez, Craig S.

    2013-01-01

    This paper presents a class of kernel-free boundary integral (KFBI) methods for general elliptic boundary value problems (BVPs). The boundary integral equations reformulated from the BVPs are solved iteratively with the GMRES method. During the iteration, the boundary and volume integrals involving Green's functions are approximated by structured grid-based numerical solutions, which avoids the need to know the analytical expressions of Green's functions. The KFBI method assumes that the larger regular domain, which embeds the original complex domain, can be easily partitioned into a hierarchy of structured grids so that fast elliptic solvers such as the fast Fourier transform (FFT) based Poisson/Helmholtz solvers or those based on geometric multigrid iterations are applicable. The structured grid-based solutions are obtained with standard finite difference method (FDM) or finite element method (FEM), where the right hand side of the resulting linear system is appropriately modified at irregular grid nodes to recover the formal accuracy of the underlying numerical scheme. Numerical results demonstrating the efficiency and accuracy of the KFBI methods are presented. It is observed that the number of GM-RES iterations used by the method for solving isotropic and moderately anisotropic BVPs is independent of the sizes of the grids that are employed to approximate the boundary and volume integrals. With the standard second-order FEMs and FDMs, the KFBI method shows a second-order convergence rate in accuracy for all of the tested Dirichlet/Neumann BVPs when the anisotropy of the diffusion tensor is not too strong. PMID:23519600

  19. Ultrafast electron microscopy integrated with a direct electron detection camera.

    PubMed

    Lee, Young Min; Kim, Young Jae; Kim, Ye-Jin; Kwon, Oh-Hoon

    2017-07-01

    In the past decade, we have witnessed the rapid growth of the field of ultrafast electron microscopy (UEM), which provides intuitive means to watch atomic and molecular motions of matter. Yet, because of the limited current of the pulsed electron beam resulting from space-charge effects, observations have been mainly made to periodic motions of the crystalline structure of hundreds of nanometers or higher by stroboscopic imaging at high repetition rates. Here, we develop an advanced UEM with robust capabilities for circumventing the present limitations by integrating a direct electron detection camera for the first time which allows for imaging at low repetition rates. This approach is expected to promote UEM to a more powerful platform to visualize molecular and collective motions and dissect fundamental physical, chemical, and materials phenomena in space and time.

  20. Performance analysis of device-level SINS/ACFSS deeply integrated navigation method

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Qin, Shiqiao; Wang, Xingshu; Jiang, Guangwen; Tan, Wenfeng

    2016-10-01

    The Strap-Down Inertial Navigation System (SINS) is a widely used navigation system. The combination of SINS and the Celestial Navigation System (CNS) is one of the popular measures to constitute the integrated navigation system. A Star Sensor (SS) is used as a precise attitude determination device in CNS. To solve the problem that the star image obtained by SS under dynamic conditions is motion-blurred, the Attitude Correlated Frames (ACF) is presented and the star sensor which works based on ACF approach is named ACFSS. Depending on the ACF approach, a novel device-level SINS/ACFSS deeply integrated navigation method is proposed in this paper. Feedback to the ACF process from the error of the gyro is one of the typical characters of the SINS/CNS deeply integrated navigation method. Herein, simulation results have verified its validity and efficiency in improving the accuracy of gyro and it can be proved that this method is feasible in theory.

  1. Simulation electromagnetic scattering on bodies through integral equation and neural networks methods

    NASA Astrophysics Data System (ADS)

    Lvovich, I. Ya; Preobrazhenskiy, A. P.; Choporov, O. N.

    2018-05-01

    The paper deals with the issue of electromagnetic scattering on a perfectly conducting diffractive body of a complex shape. Performance calculation of the body scattering is carried out through the integral equation method. Fredholm equation of the second time was used for calculating electric current density. While solving the integral equation through the moments method, the authors have properly described the core singularity. The authors determined piecewise constant functions as basic functions. The chosen equation was solved through the moments method. Within the Kirchhoff integral approach it is possible to define the scattered electromagnetic field, in some way related to obtained electrical currents. The observation angles sector belongs to the area of the front hemisphere of the diffractive body. To improve characteristics of the diffractive body, the authors used a neural network. All the neurons contained a logsigmoid activation function and weighted sums as discriminant functions. The paper presents the matrix of weighting factors of the connectionist model, as well as the results of the optimized dimensions of the diffractive body. The paper also presents some basic steps in calculation technique of the diffractive bodies, based on the combination of integral equation and neural networks methods.

  2. Modeling of Inverted Annular Film Boiling using an integral method

    NASA Astrophysics Data System (ADS)

    Sridharan, Arunkumar

    In modeling Inverted Annular Film Boiling (IAFB), several important phenomena such as interaction between the liquid and the vapor phases and irregular nature of the interface, which greatly influence the momentum and heat transfer at the interface, need to be accounted for. However, due to the complexity of these phenomena, they were not modeled in previous studies. Since two-phase heat transfer equations and relationships rely heavily on experimental data, many closure relationships that were used in previous studies to solve the problem are empirical in nature. Also, in deriving the relationships, the experimental data were often extrapolated beyond the intended range of conditions, causing errors in predictions. In some cases, empirical correlations that were derived from situations other than IAFB, and whose applicability to IAFB was questionable, were used. Moreover, arbitrary constants were introduced in the model developed in previous studies to provide good fit to the experimental data. These constants have no physical basis, thereby leading to questionable accuracy in the model predictions. In the present work, modeling of Inverted Annular Film Boiling (IAFB) is done using Integral Method. Two-dimensional formulation of IAFB is presented. Separate equations for the conservation of mass, momentum and energy are derived from first principles, for the vapor film and the liquid core. Turbulence is incorporated in the formulation. The system of second-order partial differential equations is integrated over the radial direction to obtain a system of integral differential equations. In order to solve the system of equations, second order polynomial profiles are used to describe the nondimensional velocity and temperatures. The unknown coefficients in the profiles are functions of the axial direction alone. Using the boundary conditions that govern the physical problem, equations for the unknown coefficients are derived in terms of the primary dependent variables

  3. Direct injection GC method for measuring light hydrocarbon emissions from cooling-tower water.

    PubMed

    Lee, Max M; Logan, Tim D; Sun, Kefu; Hurley, N Spencer; Swatloski, Robert A; Gluck, Steve J

    2003-12-15

    A Direct Injection GC method for quantifying low levels of light hydrocarbons (C6 and below) in cooling water has been developed. It is intended to overcome the limitations of the currently available technology. The principle of this method is to use a stripper column in a GC to strip waterfrom the hydrocarbons prior to entering the separation column. No sample preparation is required since the water sample is introduced directly into the GC. Method validation indicates that the Direct Injection GC method offers approximately 15 min analysis time with excellent precision and recovery. The calibration studies with ethylene and propylene show that both liquid and gas standards are suitable for routine calibration and calibration verification. The sampling method using zero headspace traditional VOA (Volatile Organic Analysis) vials and a sample chiller has also been validated. It is apparent that the sampling method is sufficient to minimize the potential for losses of light hydrocarbons, and samples can be held at 4 degrees C for up to 7 days with more than 93% recovery. The Direct Injection GC method also offers <1 ppb (w/v) level method detection limits for ethylene, propylene, and benzene. It is superior to the existing El Paso stripper method. In addition to lower detection limits for ethylene and propylene, the Direct Injection GC method quantifies individual light hydrocarbons in cooling water, provides better recoveries, and requires less maintenance and setup costs. Since the instrumentation and supplies are readily available, this technique could easily be established as a standard or alternative method for routine emission monitoring and leak detection of light hydrocarbons in cooling-tower water.

  4. Testing Backwards Integration As A Method Of Age-Determination for KBO Families

    NASA Astrophysics Data System (ADS)

    Benfell, Nathan; Ragozzine, Darin

    2017-10-01

    The age of young asteroid collisional families is often determined by using backwards n-body integration of the solar system. This method is not used for discovering young asteroid families and is limited by the unpredictable influence of the Yarkovsky effect on individual specific asteroids over time. Since these limitations are not as important for objects in the Kuiper belt Marcus et al. 2011 suggested that backwards integration could be used to discover and characterize collisional families in the outer solar system. However, there are some minor effects that may be important to include in the integration to ensure a faithful reproduction of the actual solar system. We have created simulated families of Kuiper Belt objects through a forwards integration of various objects with identical starting locations and velocity distributions, based on the Haumea family. After carrying this integration forwards through ~4 Gyr, backwards integrations are used (1) to investigate which factors are of enough significance to require inclusion in the integration (e.g., terrestrial planets, KBO self-gravity, putative Planet 9, etc.), (2) to test orbital element clustering statistics and identify methods for assessing false alarm probabilities, and (3) to compare the age estimates with the known age of the simulated family to explore the viability of backwards integration for precise age estimates.

  5. 29 CFR 4211.35 - Direct attribution method for withdrawals after the initial plan year.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHDRAWING EMPLOYERS Allocation Methods for Merged Multiemployer Plans § 4211.35 Direct attribution method for withdrawals after the initial plan year. The allocation method under this section is the... 29 Labor 9 2010-07-01 2010-07-01 false Direct attribution method for withdrawals after the initial...

  6. On method of solving third-order ordinary differential equations directly using Bernstein polynomials

    NASA Astrophysics Data System (ADS)

    Khataybeh, S. N.; Hashim, I.

    2018-04-01

    In this paper, we propose for the first time a method based on Bernstein polynomials for solving directly a class of third-order ordinary differential equations (ODEs). This method gives a numerical solution by converting the equation into a system of algebraic equations which is solved directly. Some numerical examples are given to show the applicability of the method.

  7. An Integrated Approach to Research Methods and Capstone

    ERIC Educational Resources Information Center

    Postic, Robert; McCandless, Ray; Stewart, Beth

    2014-01-01

    In 1991, the AACU issued a report on improving undergraduate education suggesting, in part, that a curriculum should be both comprehensive and cohesive. Since 2008, we have systematically integrated our research methods course with our capstone course in an attempt to accomplish the twin goals of comprehensiveness and cohesion. By taking this…

  8. New method for analyzing dark matter direct detection data

    NASA Astrophysics Data System (ADS)

    Davis, Jonathan H.; Enßlin, Torsten; BÅ`hm, Céline

    2014-02-01

    The experimental situation of dark matter direct detection has reached an exciting crossroads, with potential hints of a discovery of dark matter (DM) from the CDMS, CoGeNT, CRESST-II and DAMA experiments in tension with null results from xenon-based experiments such as XENON100 and LUX. Given the present controversial experimental status, it is important that the analytical method used to search for DM in direct detection experiments is both robust and flexible enough to deal with data for which the distinction between signal and background points is difficult, and hence where the choice between setting a limit or defining a discovery region is debatable. In this article we propose a novel (Bayesian) analytical method, which can be applied to all direct detection experiments and which extracts the maximum amount of information from the data. We apply our method to the XENON100 experiment data as a worked example, and show that firstly our exclusion limit at 90% confidence is in agreement with their own for the 225 live days data, but is several times stronger for the 100 live days data. Secondly we find that, due to the two points at low values of S1 and S2 in the 225 days data set, our analysis points to either weak consistency with low-mass dark matter or the possible presence of an unknown background. Given the null result from LUX, the latter scenario seems the more plausible.

  9. Conceptual Design of a 100kW Energy Integrated Type Bi-Directional Tidal Current Turbine

    NASA Astrophysics Data System (ADS)

    Kim, Ki Pyoung; Ahmed, M. Rafiuddin; Lee, Young Ho

    2010-06-01

    The development of a tidal current turbine that can extract maximum energy from the tidal current will be extremely beneficial for supplying continuous electric power. The present paper presents a conceptual design of a 100kW energy integrated type tidal current turbine for tidal power generation. The instantaneous power density of a flowing fluid incident on an underwater turbine is proportional to the cubic power of current velocity which is approximately 2.5m/s. A cross-flow turbine, provided with a nozzle and a diffuser, is designed and analyzed. The potential advantages of ducted and diffuser-augmented turbines were taken into consideration in order to achieve higher output at a relatively low speed. This study looks at a cross-flow turbine system which is placed in an augmentation channel to generate electricity bi-directionally. The compatibility of this turbine system is verified using a commercial CFD code, ANSYSCFX. This paper presents the results of the numerical analysis in terms of pressure, streaklines, velocity vectors and performance curves for energy integrated type bi-directional tidal current turbine (BDT) with augmentation.

  10. Method for integrating microelectromechanical devices with electronic circuitry

    DOEpatents

    Montague, Stephen; Smith, James H.; Sniegowski, Jeffry J.; McWhorter, Paul J.

    1998-01-01

    A method for integrating one or more microelectromechanical (MEM) devices with electronic circuitry. The method comprises the steps of forming each MEM device within a cavity below a device surface of the substrate; encapsulating the MEM device prior to forming electronic circuitry on the substrate; and releasing the MEM device for operation after fabrication of the electronic circuitry. Planarization of the encapsulated MEM device prior to formation of the electronic circuitry allows the use of standard processing steps for fabrication of the electronic circuitry.

  11. Advances and future directions of research on spectral methods

    NASA Technical Reports Server (NTRS)

    Patera, A. T.

    1986-01-01

    Recent advances in spectral methods are briefly reviewed and characterized with respect to their convergence and computational complexity. Classical finite element and spectral approaches are then compared, and spectral element (or p-type finite element) approximations are introduced. The method is applied to the full Navier-Stokes equations, and examples are given of the application of the technique to several transitional flows. Future directions of research in the field are outlined.

  12. Method for determining shear direction using liquid crystal coatings

    NASA Technical Reports Server (NTRS)

    Reda, Daniel C.

    1995-01-01

    A method is provided for determining shear direction wherein a beam of white light is directed onto the surface of a liquid crystal coating to cause the white light to be dispersed (reflected) from the surface in a spectrum having bands of different colors in a fixed spatial 2 (angular) sequence. The system is calibrated by locating an observer, e.g., a video and movie camera, such that a particular color band (preferably at or near the center of the reflected spectrum) is observed to thereby provide a reference color band. Because the application of shear causes either clockwise or counterclockwise rotation of the reflected spectrum dependent on the direction of the shear, a determination is then made of the reflected color band observed by the observer when the surface of the liquid crystal is subjected to shear to thereby determine the direction of the shear based on the directional (rotation) relation of the observed color band with respect to the reference color band in the spatial sequence of color bands.

  13. The general 2-D moments via integral transform method for acoustic radiation and scattering

    NASA Astrophysics Data System (ADS)

    Smith, Jerry R.; Mirotznik, Mark S.

    2004-05-01

    The moments via integral transform method (MITM) is a technique to analytically reduce the 2-D method of moments (MoM) impedance double integrals into single integrals. By using a special integral representation of the Green's function, the impedance integral can be analytically simplified to a single integral in terms of transformed shape and weight functions. The reduced expression requires fewer computations and reduces the fill times of the MoM impedance matrix. Furthermore, the resulting integral is analytic for nearly arbitrary shape and weight function sets. The MITM technique is developed for mixed boundary conditions and predictions with basic shape and weight function sets are presented. Comparisons of accuracy and speed between MITM and brute force are presented. [Work sponsored by ONR and NSWCCD ILIR Board.

  14. Integrative Mixed Methods Data Analytic Strategies in Research on School Success in Challenging Circumstances

    ERIC Educational Resources Information Center

    Jang, Eunice E.; McDougall, Douglas E.; Pollon, Dawn; Herbert, Monique; Russell, Pia

    2008-01-01

    There are both conceptual and practical challenges in dealing with data from mixed methods research studies. There is a need for discussion about various integrative strategies for mixed methods data analyses. This article illustrates integrative analytic strategies for a mixed methods study focusing on improving urban schools facing challenging…

  15. An integration time adaptive control method for atmospheric composition detection of occultation

    NASA Astrophysics Data System (ADS)

    Ding, Lin; Hou, Shuai; Yu, Fei; Liu, Cheng; Li, Chao; Zhe, Lin

    2018-01-01

    When sun is used as the light source for atmospheric composition detection, it is necessary to image sun for accurate identification and stable tracking. In the course of 180 second of the occultation, the magnitude of sun light intensity through the atmosphere changes greatly. It is nearly 1100 times illumination change between the maximum atmospheric and the minimum atmospheric. And the process of light change is so severe that 2.9 times per second of light change can be reached. Therefore, it is difficult to control the integration time of sun image camera. In this paper, a novel adaptive integration time control method for occultation is presented. In this method, with the distribution of gray value in the image as the reference variable, and the concepts of speed integral PID control, the integration time adaptive control problem of high frequency imaging. The large dynamic range integration time automatic control in the occultation can be achieved.

  16. Experimental test of the polarization direction correlation method (PDCO)

    NASA Astrophysics Data System (ADS)

    Starosta, K.; Morek, T.; Droste, Ch.; Rohoziński, S. G.; Srebrny, J.; Wierzchucka, A.; Bergström, M.; Herskind, B.; Melby, E.; Czosnyka, T.; Napiorkowski, P. J.

    1999-02-01

    The study of the polarization direction correlation method (PDCO) for γ quanta emitted from the nuclear states oriented in fusion-evaporation reactions is discussed with emphasis on making unique multipolarity assignments. The method is applied to the data coming from a typical experiment performed with the EUROGAM II array, where polarization-sensitive CLOVER detectors were used. The accuracy obtained in the experiment for the studied transitions was high enough to exclude, using the PDCO method, most of the ambiguities which occur if the assignments are made on the basis of angular correlation measurements alone.

  17. Quantitative methods to direct exploration based on hydrogeologic information

    USGS Publications Warehouse

    Graettinger, A.J.; Lee, J.; Reeves, H.W.; Dethan, D.

    2006-01-01

    Quantitatively Directed Exploration (QDE) approaches based on information such as model sensitivity, input data covariance and model output covariance are presented. Seven approaches for directing exploration are developed, applied, and evaluated on a synthetic hydrogeologic site. The QDE approaches evaluate input information uncertainty, subsurface model sensitivity and, most importantly, output covariance to identify the next location to sample. Spatial input parameter values and covariances are calculated with the multivariate conditional probability calculation from a limited number of samples. A variogram structure is used during data extrapolation to describe the spatial continuity, or correlation, of subsurface information. Model sensitivity can be determined by perturbing input data and evaluating output response or, as in this work, sensitivities can be programmed directly into an analysis model. Output covariance is calculated by the First-Order Second Moment (FOSM) method, which combines the covariance of input information with model sensitivity. A groundwater flow example, modeled in MODFLOW-2000, is chosen to demonstrate the seven QDE approaches. MODFLOW-2000 is used to obtain the piezometric head and the model sensitivity simultaneously. The seven QDE approaches are evaluated based on the accuracy of the modeled piezometric head after information from a QDE sample is added. For the synthetic site used in this study, the QDE approach that identifies the location of hydraulic conductivity that contributes the most to the overall piezometric head variance proved to be the best method to quantitatively direct exploration. ?? IWA Publishing 2006.

  18. 49 CFR 192.923 - How is direct assessment used and for what threats?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Transmission Pipeline Integrity Management § 192.923 How is direct assessment used and for what threats? (a... corrosion (ICDA), and stress corrosion cracking (SCCDA). (b) Primary method. An operator using direct..., appendix A3, and § 192.929 if addressing stress corrosion cracking (SCCDA). (c) Supplemental method. An...

  19. 49 CFR 192.923 - How is direct assessment used and for what threats?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Transmission Pipeline Integrity Management § 192.923 How is direct assessment used and for what threats? (a... corrosion (ICDA), and stress corrosion cracking (SCCDA). (b) Primary method. An operator using direct..., appendix A3, and § 192.929 if addressing stress corrosion cracking (SCCDA). (c) Supplemental method. An...

  20. 49 CFR 192.923 - How is direct assessment used and for what threats?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Transmission Pipeline Integrity Management § 192.923 How is direct assessment used and for what threats? (a... corrosion (ICDA), and stress corrosion cracking (SCCDA). (b) Primary method. An operator using direct..., appendix A3, and § 192.929 if addressing stress corrosion cracking (SCCDA). (c) Supplemental method. An...

  1. 49 CFR 192.923 - How is direct assessment used and for what threats?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transmission Pipeline Integrity Management § 192.923 How is direct assessment used and for what threats? (a... corrosion (ICDA), and stress corrosion cracking (SCCDA). (b) Primary method. An operator using direct..., appendix A3, and § 192.929 if addressing stress corrosion cracking (SCCDA). (c) Supplemental method. An...

  2. Application of direct-injection detector integrated with the multi-pumping flow system to chemiluminescence determination of the total polyphenol index.

    PubMed

    Nalewajko-Sieliwoniuk, Edyta; Iwanowicz, Magdalena; Kalinowski, Sławomir; Kojło, Anatol

    2016-03-10

    In this work, we present a novel chemiluminescence (CL) method based on direct-injection detector (DID) integrated with the multi-pumping flow system (MPFS) to chemiluminescence determination of the total polyphenol index. In this flow system, the sample and the reagents are injected directly into the cone-shaped detection cell placed in front of the photomultiplier window. Such construction of the detection chamber allows for fast measurement of the CL signal in stopped-flow conditions immediately after mixing the reagents. The proposed DID-CL-MPFS method is based on the chemiluminescence of nanocolloidal manganese(IV)-hexametaphosphate-ethanol system. The application of ethanol as a sensitizer, eliminated the use of carcinogenic formaldehyde. Under the optimized experimental conditions, the chemiluminescence intensities are proportional to the concentration of gallic acid in the range from 5 to 350 ng mL(-1). The DID-CL-MPFS method offers a number of advantages, including low limit of detection (0.80 ng mL(-1)), high precision (RSD = 3.3%) and high sample throughput (144 samples h(-1)) as well as low consumption of reagents, energy and low waste generation. The proposed method has been successfully applied to determine the total polyphenol index (expressed as gallic acid equivalent) in a variety of plant-derived food samples (wine, tea, coffee, fruit and vegetable juices, herbs, spices). Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Photometric method for determination of acidity constants through integral spectra analysis

    NASA Astrophysics Data System (ADS)

    Zevatskiy, Yuriy Eduardovich; Ruzanov, Daniil Olegovich; Samoylov, Denis Vladimirovich

    2015-04-01

    An express method for determination of acidity constants of organic acids, based on the analysis of the integral transmittance vs. pH dependence is developed. The integral value is registered as a photocurrent of photometric device simultaneously with potentiometric titration. The proposed method allows to obtain pKa using only simple and low-cost instrumentation. The optical part of the experimental setup has been optimized through the exclusion of the monochromator device. Thus it only takes 10-15 min to obtain one pKa value with the absolute error of less than 0.15 pH units. Application limitations and reliability of the method have been tested for a series of organic acids of various nature.

  4. A Direction Finding Method with A 3-D Array Based on Aperture Synthesis

    NASA Astrophysics Data System (ADS)

    Li, Shiwen; Chen, Liangbing; Gao, Zhaozhao; Ma, Wenfeng

    2018-01-01

    Direction finding for electronic warfare application should provide a wider field of view as possible. But the maximum unambiguous field of view for conventional direction finding methods is a hemisphere. It cannot distinguish the direction of arrival of the signals from the back lobe of the array. In this paper, a full 3-D direction finding method based on aperture synthesis radiometry is proposed. The model of the direction finding system is illustrated, and the fundamentals are presented. The relationship between the outputs of the measurements of a 3-D array and the 3-D power distribution of the point sources can be represented by a 3-D Fourier transform, and then the 3-D power distribution of the point sources can be reconstructed by an inverse 3-D Fourier transform. And in order to display the 3-D power distribution of the point sources conveniently, the whole spherical distribution is represented by two 2-D circular distribution images, one of which is for the upper hemisphere, and the other is for the lower hemisphere. Then a numeric simulation is designed and conducted to demonstrate the feasibility of the method. The results show that the method can estimate the arbitrary direction of arrival of the signals in the 3-D space correctly.

  5. Method for integrating microelectromechanical devices with electronic circuitry

    DOEpatents

    Montague, S.; Smith, J.H.; Sniegowski, J.J.; McWhorter, P.J.

    1998-08-25

    A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry. The method comprises the steps of forming each MEM device within a cavity below a device surface of the substrate; encapsulating the MEM device prior to forming electronic circuitry on the substrate; and releasing the MEM device for operation after fabrication of the electronic circuitry. Planarization of the encapsulated MEM device prior to formation of the electronic circuitry allows the use of standard processing steps for fabrication of the electronic circuitry. 13 figs.

  6. Costs and benefits in item-method directed forgetting: differential effects of encoding and retrieval.

    PubMed

    Lee, Yuh-Shiow

    2013-01-01

    This study examined how encoding and retrieval factors affected directed forgetting costs and benefits in an item-method procedure. Experiment 1 used a typical item-method procedure and revealed a levels-of-processing effect in overall recall. However, the deep encoding condition showed a smaller directed forgetting effect than the shallow encoding conditions. More importantly, "remember" (R) words were selectively rehearsed as indicated by greater recall from the primacy portion of the list and more apt to be recalled before "forget" (F) words. Experiment 2 showed that a deep encoding operation reduced directed forgetting costs and that directed forgetting benefits occurred only when R words were recalled before F words. These findings supported the hypotheses that encoding manipulation affected directed forgetting costs and that directed forgetting benefits were associated with output order bias. Results were discussed in terms of mechanisms that produce item-method directed forgetting.

  7. Application of the critical pathway and integrated case teaching method to nursing orientation.

    PubMed

    Goodman, D

    1997-01-01

    Nursing staff development programs must be responsive to current changes in healthcare. New nursing staff must be prepared to manage continuous change and to function competently in clinical practice. The orientation pathway, based on a case management model, is used as a structure for the orientation phase of staff development. The integrated case is incorporated as a teaching strategy in orientation. The integrated case method is based on discussion and analysis of patient situations with emphasis on role modeling and integration of theory and skill. The orientation pathway and integrated case teaching method provide a useful framework for orientation of new staff. Educators, preceptors and orientees find the structure provided by the orientation pathway very useful. Orientation that is developed, implemented and evaluated based on a case management model with the use of an orientation pathway and incorporation of an integrated case teaching method provides a standardized structure for orientation of new staff. This approach is designed for the adult learner, promotes conceptual reasoning, and encourages the social and contextual basis for continued learning.

  8. On the direct acquisition of beam’s-eye-view images in MRI for integration with external beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Wachowicz, K.; Murray, B.; Fallone, B. G.

    2018-06-01

    The recent interest in the integration of external beam radiotherapy with a magnetic resonance (MR) imaging unit offers the potential for real-time adaptive tumour tracking during radiation treatment. The tracking of large tumours which follow a rapid trajectory may best be served by the generation of a projection image from the perspective of the beam source, or ‘beam’s eye view’ (BEV). This type of image projection represents the path of the radiation beam, thus enabling rapid compensations for target translations, rotations and deformations, as well time-dependent critical structure avoidance. MR units have been traditionally incapable of this type of imaging except through lengthy 3D acquisitions and ray tracing procedures. This work investigates some changes to the traditional MR scanner architecture that would permit the direct acquisition of a BEV image suitable for integration with external beam radiotherapy. Based on the theory presented in this work, a phantom was imaged with nonlinear encoding-gradient field patterns to demonstrate the technique. The phantom was constructed with agarose gel tubes spaced two cm apart at their base and oriented to converge towards an imaginary beam source 100 cm away. A corresponding virtual phantom was also created and subjected to the same encoding technique as in the physical demonstration, allowing the method to be tested without hardware limitations. The experimentally acquired and simulated images indicate the feasibility of the technique, showing a substantial amount of blur reduction in a diverging phantom compared to the conventional imaging geometry, particularly with the nonlinear gradients ideally implemented. The theory is developed to demonstrate that the method can be adapted in a number of different configurations to accommodate all proposed integration schemes for MR units and radiotherapy sources. Depending on the configuration, the implementation of this technique will require between two and

  9. An integrated bioanalytical method development and validation approach: case studies.

    PubMed

    Xue, Y-J; Melo, Brian; Vallejo, Martha; Zhao, Yuwen; Tang, Lina; Chen, Yuan-Shek; Keller, Karin M

    2012-10-01

    We proposed an integrated bioanalytical method development and validation approach: (1) method screening based on analyte's physicochemical properties and metabolism information to determine the most appropriate extraction/analysis conditions; (2) preliminary stability evaluation using both quality control and incurred samples to establish sample collection, storage and processing conditions; (3) mock validation to examine method accuracy and precision and incurred sample reproducibility; and (4) method validation to confirm the results obtained during method development. This integrated approach was applied to the determination of compound I in rat plasma and compound II in rat and dog plasma. The effectiveness of the approach was demonstrated by the superior quality of three method validations: (1) a zero run failure rate; (2) >93% of quality control results within 10% of nominal values; and (3) 99% incurred sample within 9.2% of the original values. In addition, rat and dog plasma methods for compound II were successfully applied to analyze more than 900 plasma samples obtained from Investigational New Drug (IND) toxicology studies in rats and dogs with near perfect results: (1) a zero run failure rate; (2) excellent accuracy and precision for standards and quality controls; and (3) 98% incurred samples within 15% of the original values. Copyright © 2011 John Wiley & Sons, Ltd.

  10. Nouvelle methode d'integration energetique pour la retro-installation des procedes industriels et la transformation des usines papetieres

    NASA Astrophysics Data System (ADS)

    Bonhivers, Jean-Christophe

    is the first that considers the analysis of these degradations. The fundamental mechanism to reduce the heat consumption in an existing network has been made explicit; it is the basis of the developed method. The Bridge Method includes the definition of "a bridge", which is a set of modifications leading to heat reduction in a heat exchanger network. It is proven that, for a given set of streams, only bridges can lead to heat savings. The Bridge Method also includes (1) a global procedure for heat exchanger network retrofit, (2) a procedure to enumerate systematically the bridges, (3) "a network table" to easily evaluate them, and (4) an "energy transfer diagram" showing the effect of the two first principles of thermodynamics of energy conservation and degradation in industrial processes in order to identify energy savings opportunities. The Bridge Method can be used for the analysis of networks including several types of heat transfer, and site-wide analysis. The Bridge Method has been applied in case studies for retrofitting networks composed of indirect-contact heat exchangers, including the network of a kraft pulp mill, and also networks of direct-contact heat exchangers, including the hot water production system of a pulp mill. The method has finally been applied for the evaluation of a biorefinery process, alone or hosted in a kraft pulp mill. Results show that the use of the method significantly reduces the search space and leads to identification of the relevant solutions. The necessity of a bridge to reduce the inputs and outputs of a process is a consequence of the two first thermodynamics principles of energy conservation and increase in entropy. The concept of bridge alone can also be used as a tool for process analysis, and in numerical optimization-based approaches for energy integration.

  11. A Robust Method to Integrate End-to-End Mission Architecture Optimization Tools

    NASA Technical Reports Server (NTRS)

    Lugo, Rafael; Litton, Daniel; Qu, Min; Shidner, Jeremy; Powell, Richard

    2016-01-01

    End-to-end mission simulations include multiple phases of flight. For example, an end-to-end Mars mission simulation may include launch from Earth, interplanetary transit to Mars and entry, descent and landing. Each phase of flight is optimized to meet specified constraints and often depend on and impact subsequent phases. The design and optimization tools and methodologies used to combine different aspects of end-to-end framework and their impact on mission planning are presented. This work focuses on a robust implementation of a Multidisciplinary Design Analysis and Optimization (MDAO) method that offers the flexibility to quickly adapt to changing mission design requirements. Different simulations tailored to the liftoff, ascent, and atmospheric entry phases of a trajectory are integrated and optimized in the MDAO program Isight, which provides the user a graphical interface to link simulation inputs and outputs. This approach provides many advantages to mission planners, as it is easily adapted to different mission scenarios and can improve the understanding of the integrated system performance within a particular mission configuration. A Mars direct entry mission using the Space Launch System (SLS) is presented as a generic end-to-end case study. For the given launch period, the SLS launch performance is traded for improved orbit geometry alignment, resulting in an optimized a net payload that is comparable to that in the SLS Mission Planner's Guide.

  12. A Comparison of Treatment Integrity Assessment Methods for Behavioral Intervention

    ERIC Educational Resources Information Center

    Koh, Seong A.

    2010-01-01

    The purpose of this study was to examine the similarity of outcomes from three different treatment integrity (TI) methods, and to identify the method which best corresponded to the assessment of a child's behavior. Six raters were recruited through individual contact via snowball sampling. A modified intervention component list and 19 video clips…

  13. User's guide to Monte Carlo methods for evaluating path integrals

    NASA Astrophysics Data System (ADS)

    Westbroek, Marise J. E.; King, Peter R.; Vvedensky, Dimitri D.; Dürr, Stephan

    2018-04-01

    We give an introduction to the calculation of path integrals on a lattice, with the quantum harmonic oscillator as an example. In addition to providing an explicit computational setup and corresponding pseudocode, we pay particular attention to the existence of autocorrelations and the calculation of reliable errors. The over-relaxation technique is presented as a way to counter strong autocorrelations. The simulation methods can be extended to compute observables for path integrals in other settings.

  14. Proteus: a direct forcing method in the simulations of particulate flows

    NASA Astrophysics Data System (ADS)

    Feng, Zhi-Gang; Michaelides, Efstathios E.

    2005-01-01

    A new and efficient direct numerical method for the simulation of particulate flows is introduced. The method combines desired elements of the immersed boundary method, the direct forcing method and the lattice Boltzmann method. Adding a forcing term in the momentum equation enforces the no-slip condition on the boundary of a moving particle. By applying the direct forcing scheme, Proteus eliminates the need for the determination of free parameters, such as the stiffness coefficient in the penalty scheme or the two relaxation parameters in the adaptive-forcing scheme. The method presents a significant improvement over the previously introduced immersed-boundary-lattice-Boltzmann method (IB-LBM) where the forcing term was computed using a penalty method and a user-defined parameter. The method allows the enforcement of the rigid body motion of a particle in a more efficient way. Compared to the "bounce-back" scheme used in the conventional LBM, the direct-forcing method provides a smoother computational boundary for particles and is capable of achieving results at higher Reynolds number flows. By using a set of Lagrangian points to track the boundary of a particle, Proteus eliminates any need for the determination of the boundary nodes that are prescribed by the "bounce-back" scheme at every time step. It also makes computations for particles of irregular shapes simpler and more efficient. Proteus has been developed in two- as well as three-dimensions. This new method has been validated by comparing its results with those from experimental measurements for a single sphere settling in an enclosure under gravity. As a demonstration of the efficiency and capabilities of the present method, the settling of a large number (1232) of spherical particles is simulated in a narrow box under two different boundary conditions. It is found that when the no-slip boundary condition is imposed at the front and rear sides of the box the particles motion is significantly hindered

  15. SU-G-TeP4-06: An Integrated Application for Radiation Therapy Treatment Plan Directives, Management, and Reporting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matuszak, M; Anderson, C; Lee, C

    Purpose: With electronic medical records, patient information for the treatment planning process has become disseminated across multiple applications with limited quality control and many associated failure modes. We present the development of a single application with a centralized database to manage the planning process. Methods: The system was designed to replace current functionalities of (i) static directives representing the physician intent for the prescription and planning goals, localization information for delivery, and other information, (ii) planning objective reports, (iii) localization and image guidance documents and (iv) the official radiation therapy prescription in the medical record. Using the Eclipse Scripting Applicationmore » Programming Interface, a plug-in script with an associated domain-specific SQL Server database was created to manage the information in (i)–(iv). The system’s user interface and database were designed by a team of physicians, clinical physicists, database experts, and software engineers to ensure usability and robustness for clinical use. Results: The resulting system has been fully integrated within the TPS via a custom script and database. Planning scenario templates, version control, approvals, and logic-based quality control allow this system to fully track and document the planning process as well as physician approval of tradeoffs while improving the consistency of the data. Multiple plans and prescriptions are supported along with non-traditional dose objectives and evaluation such as biologically corrected models, composite dose limits, and management of localization goals. User-specific custom views were developed for the attending physician review, physicist plan checks, treating therapists, and peer review in chart rounds. Conclusion: A method was developed to maintain cohesive information throughout the planning process within one integrated system by using a custom treatment planning management

  16. Prospects for direct social perception: a multi-theoretical integration to further the science of social cognition.

    PubMed

    Wiltshire, Travis J; Lobato, Emilio J C; McConnell, Daniel S; Fiore, Stephen M

    2014-01-01

    In this paper we suggest that differing approaches to the science of social cognition mirror the arguments between radical embodied and traditional approaches to cognition. We contrast the use in social cognition of theoretical inference and mental simulation mechanisms with approaches emphasizing a direct perception of others' mental states. We build from a recent integrative framework unifying these divergent perspectives through the use of dual-process theory and supporting social neuroscience research. Our elaboration considers two complementary notions of direct perception: one primarily stemming from ecological psychology and the other from enactive cognition theory. We use this as the foundation from which to offer an account of the informational basis for social information and assert a set of research propositions to further the science of social cognition. In doing so, we point out how perception of the minds of others can be supported in some cases by lawful information, supporting direct perception of social affordances and perhaps, mental states, and in other cases by cues that support indirect perceptual inference. Our goal is to extend accounts of social cognition by integrating advances across disciplines to provide a multi-level and multi-theoretic description that can advance this field and offer a means through which to reconcile radical embodied and traditional approaches to cognitive neuroscience.

  17. Integral Education: New Directions for Higher Learning. SUNY Series in Integral Theory

    ERIC Educational Resources Information Center

    Esbjorn-Hargens, Sean, Ed.; Reams, Jonathan, Ed.; Gunnlaugson, Olen, Ed.

    2010-01-01

    The educational challenges faced today are driving us toward a new step in the evolution of educational theory and practice. Educators are called to go beyond simply presenting alternatives, to integrating the best of mainstream and alternative approaches and taking them to the next level. "Integral Education" accomplishes this by…

  18. Integrated Force Method Solution to Indeterminate Structural Mechanics Problems

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Hopkins, Dale A.; Halford, Gary R.

    2004-01-01

    Strength of materials problems have been classified into determinate and indeterminate problems. Determinate analysis primarily based on the equilibrium concept is well understood. Solutions of indeterminate problems required additional compatibility conditions, and its comprehension was not exclusive. A solution to indeterminate problem is generated by manipulating the equilibrium concept, either by rewriting in the displacement variables or through the cutting and closing gap technique of the redundant force method. Compatibility improvisation has made analysis cumbersome. The authors have researched and understood the compatibility theory. Solutions can be generated with equal emphasis on the equilibrium and compatibility concepts. This technique is called the Integrated Force Method (IFM). Forces are the primary unknowns of IFM. Displacements are back-calculated from forces. IFM equations are manipulated to obtain the Dual Integrated Force Method (IFMD). Displacement is the primary variable of IFMD and force is back-calculated. The subject is introduced through response variables: force, deformation, displacement; and underlying concepts: equilibrium equation, force deformation relation, deformation displacement relation, and compatibility condition. Mechanical load, temperature variation, and support settling are equally emphasized. The basic theory is discussed. A set of examples illustrate the new concepts. IFM and IFMD based finite element methods are introduced for simple problems.

  19. State feedback integral control for a rotary direct drive servo valve using a Lyapunov function approach.

    PubMed

    Yu, Jue; Zhuang, Jian; Yu, Dehong

    2015-01-01

    This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eliminate load resistance and to achieve satisfactory position responses, this paper develops a state feedback control that integrates an integral action and a Lyapunov function. The integral action is introduced to address the nonzero steady-state error; in particular, the Lyapunov function is employed to improve control robustness by adjusting the varying parameters within their value ranges. This new controller also has the advantages of simple structure and ease of implementation. Simulation and experimental results demonstrate that the proposed controller can achieve higher control accuracy and stronger robustness. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  20. A new spatial integration method for luminous flux determination of light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaoli; Zhu, Shaolong; Shen, Haiping; Liu, Muqing

    2010-10-01

    Spatial integrated measurement using an integrating sphere is usually used for the luminous flux determination of light sources. Devices using an integrating sphere are bulky for use on a production assembly line. This paper proposes an alternative spatial integration method for accurately measuring the total luminous flux of light-emitting diodes (LEDs) having no backward emission. A compound parabolic concentrator is introduced to collect the light from an LED in conjunction with a detector which in turn measures the luminous flux. The study reported here combines both modeling and experiment to show the applicability of this novel method. The uncertainty in the measurements is then evaluated for the total luminous flux measurement from an LED.

  1. Reliable Transition State Searches Integrated with the Growing String Method.

    PubMed

    Zimmerman, Paul

    2013-07-09

    The growing string method (GSM) is highly useful for locating reaction paths connecting two molecular intermediates. GSM has often been used in a two-step procedure to locate exact transition states (TS), where GSM creates a quality initial structure for a local TS search. This procedure and others like it, however, do not always converge to the desired transition state because the local search is sensitive to the quality of the initial guess. This article describes an integrated technique for simultaneous reaction path and exact transition state search. This is achieved by implementing an eigenvector following optimization algorithm in internal coordinates with Hessian update techniques. After partial convergence of the string, an exact saddle point search begins under the constraint that the maximized eigenmode of the TS node Hessian has significant overlap with the string tangent near the TS. Subsequent optimization maintains connectivity of the string to the TS as well as locks in the TS direction, all but eliminating the possibility that the local search leads to the wrong TS. To verify the robustness of this approach, reaction paths and TSs are found for a benchmark set of more than 100 elementary reactions.

  2. Computing thermal Wigner densities with the phase integration method.

    PubMed

    Beutier, J; Borgis, D; Vuilleumier, R; Bonella, S

    2014-08-28

    We discuss how the Phase Integration Method (PIM), recently developed to compute symmetrized time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)], can be adapted to sampling/generating the thermal Wigner density, a key ingredient, for example, in many approximate schemes for simulating quantum time dependent properties. PIM combines a path integral representation of the density with a cumulant expansion to represent the Wigner function in a form calculable via existing Monte Carlo algorithms for sampling noisy probability densities. The method is able to capture highly non-classical effects such as correlation among the momenta and coordinates parts of the density, or correlations among the momenta themselves. By using alternatives to cumulants, it can also indicate the presence of negative parts of the Wigner density. Both properties are demonstrated by comparing PIM results to those of reference quantum calculations on a set of model problems.

  3. 29 CFR 4206.7 - Amount of credit in plans using the direct attribution method.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... TO A PARTIAL WITHDRAWAL § 4206.7 Amount of credit in plans using the direct attribution method. In a plan that uses the direct attribution allocation method described in section 4211(c)(4) of ERISA, the... 29 Labor 9 2010-07-01 2010-07-01 false Amount of credit in plans using the direct attribution...

  4. Advanced image based methods for structural integrity monitoring: Review and prospects

    NASA Astrophysics Data System (ADS)

    Farahani, Behzad V.; Sousa, Pedro José; Barros, Francisco; Tavares, Paulo J.; Moreira, Pedro M. G. P.

    2018-02-01

    There is a growing trend in engineering to develop methods for structural integrity monitoring and characterization of in-service mechanical behaviour of components. The fast growth in recent years of image processing techniques and image-based sensing for experimental mechanics, brought about a paradigm change in phenomena sensing. Hence, several widely applicable optical approaches are playing a significant role in support of experiment. The current review manuscript describes advanced image based methods for structural integrity monitoring, and focuses on methods such as Digital Image Correlation (DIC), Thermoelastic Stress Analysis (TSA), Electronic Speckle Pattern Interferometry (ESPI) and Speckle Pattern Shearing Interferometry (Shearography). These non-contact full-field techniques rely on intensive image processing methods to measure mechanical behaviour, and evolve even as reviews such as this are being written, which justifies a special effort to keep abreast of this progress.

  5. Capturing method for integral three-dimensional imaging using multiviewpoint robotic cameras

    NASA Astrophysics Data System (ADS)

    Ikeya, Kensuke; Arai, Jun; Mishina, Tomoyuki; Yamaguchi, Masahiro

    2018-03-01

    Integral three-dimensional (3-D) technology for next-generation 3-D television must be able to capture dynamic moving subjects with pan, tilt, and zoom camerawork as good as in current TV program production. We propose a capturing method for integral 3-D imaging using multiviewpoint robotic cameras. The cameras are controlled through a cooperative synchronous system composed of a master camera controlled by a camera operator and other reference cameras that are utilized for 3-D reconstruction. When the operator captures a subject using the master camera, the region reproduced by the integral 3-D display is regulated in real space according to the subject's position and view angle of the master camera. Using the cooperative control function, the reference cameras can capture images at the narrowest view angle that does not lose any part of the object region, thereby maximizing the resolution of the image. 3-D models are reconstructed by estimating the depth from complementary multiviewpoint images captured by robotic cameras arranged in a two-dimensional array. The model is converted into elemental images to generate the integral 3-D images. In experiments, we reconstructed integral 3-D images of karate players and confirmed that the proposed method satisfied the above requirements.

  6. A comparison of non-integrating reprogramming methods

    PubMed Central

    Schlaeger, Thorsten M; Daheron, Laurence; Brickler, Thomas R; Entwisle, Samuel; Chan, Karrie; Cianci, Amelia; DeVine, Alexander; Ettenger, Andrew; Fitzgerald, Kelly; Godfrey, Michelle; Gupta, Dipti; McPherson, Jade; Malwadkar, Prerana; Gupta, Manav; Bell, Blair; Doi, Akiko; Jung, Namyoung; Li, Xin; Lynes, Maureen S; Brookes, Emily; Cherry, Anne B C; Demirbas, Didem; Tsankov, Alexander M; Zon, Leonard I; Rubin, Lee L; Feinberg, Andrew P; Meissner, Alexander; Cowan, Chad A; Daley, George Q

    2015-01-01

    Human induced pluripotent stem cells (hiPSCs1–3) are useful in disease modeling and drug discovery, and they promise to provide a new generation of cell-based therapeutics. To date there has been no systematic evaluation of the most widely used techniques for generating integration-free hiPSCs. Here we compare Sendai-viral (SeV)4, episomal (Epi)5 and mRNA transfection mRNA6 methods using a number of criteria. All methods generated high-quality hiPSCs, but significant differences existed in aneuploidy rates, reprogramming efficiency, reliability and workload. We discuss the advantages and shortcomings of each approach, and present and review the results of a survey of a large number of human reprogramming laboratories on their independent experiences and preferences. Our analysis provides a valuable resource to inform the use of specific reprogramming methods for different laboratories and different applications, including clinical translation. PMID:25437882

  7. Social network extraction based on Web: 3. the integrated superficial method

    NASA Astrophysics Data System (ADS)

    Nasution, M. K. M.; Sitompul, O. S.; Noah, S. A.

    2018-03-01

    The Web as a source of information has become part of the social behavior information. Although, by involving only the limitation of information disclosed by search engines in the form of: hit counts, snippets, and URL addresses of web pages, the integrated extraction method produces a social network not only trusted but enriched. Unintegrated extraction methods may produce social networks without explanation, resulting in poor supplemental information, or resulting in a social network of durmise laden, consequently unrepresentative social structures. The integrated superficial method in addition to generating the core social network, also generates an expanded network so as to reach the scope of relation clues, or number of edges computationally almost similar to n(n - 1)/2 for n social actors.

  8. Photometric method for determination of acidity constants through integral spectra analysis.

    PubMed

    Zevatskiy, Yuriy Eduardovich; Ruzanov, Daniil Olegovich; Samoylov, Denis Vladimirovich

    2015-04-15

    An express method for determination of acidity constants of organic acids, based on the analysis of the integral transmittance vs. pH dependence is developed. The integral value is registered as a photocurrent of photometric device simultaneously with potentiometric titration. The proposed method allows to obtain pKa using only simple and low-cost instrumentation. The optical part of the experimental setup has been optimized through the exclusion of the monochromator device. Thus it only takes 10-15 min to obtain one pKa value with the absolute error of less than 0.15 pH units. Application limitations and reliability of the method have been tested for a series of organic acids of various nature. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Three-dimensional analysis of chevron-notched specimens by boundary integral method

    NASA Technical Reports Server (NTRS)

    Mendelson, A.; Ghosn, L.

    1983-01-01

    The chevron-notched short bar and short rod specimens was analyzed by the boundary integral equations method. This method makes use of boundary surface elements in obtaining the solution. The boundary integral models were composed of linear triangular and rectangular surface segments. Results were obtained for two specimens with width to thickness ratios of 1.45 and 2.00 and for different crack length to width ratios ranging from 0.4 to 0.7. Crack opening displacement and stress intensity factors determined from displacement calculations along the crack front and compliance calculations were compared with experimental values and with finite element analysis.

  10. Indirect (source-free) integration method. II. Self-force consistent radial fall

    NASA Astrophysics Data System (ADS)

    Ritter, Patxi; Aoudia, Sofiane; Spallicci, Alessandro D. A. M.; Cordier, Stéphane

    2016-12-01

    We apply our method of indirect integration, described in Part I, at fourth order, to the radial fall affected by the self-force (SF). The Mode-Sum regularization is performed in the Regge-Wheeler gauge using the equivalence with the harmonic gauge for this orbit. We consider also the motion subjected to a self-consistent and iterative correction determined by the SF through osculating stretches of geodesics. The convergence of the results confirms the validity of the integration method. This work complements and justifies the analysis and the results appeared in [Int. J. Geom. Meth. Mod. Phys. 11 (2014) 1450090].

  11. Comparison of laser spectroscopic PNC method with laser integral fluorescence in optical caries diagnostics

    NASA Astrophysics Data System (ADS)

    Masychev, Victor I.

    2001-05-01

    In this research we represent the results of approbation of two methods of optical caries diagnostics: PNC-spectral diagnostics and caries detection by laser integral fluorescence. The research was conducted in a dental clinic. PNC-method analyzes parameters of probing laser radiation and PNC-spectrums of stimulated secondary radiations: backscattering and endogenous fluorescence of caries- involved bacteria. Ia-Ne laser ((lambda) equals632.8 nm, 1-2 mW) was used as a source of probing (stimulated) radiation. For registration of signals, received from intact and pathological teeth PDA-detector was applied. PNC-spectrums were processed by special algorithms, and were displayed on PC monitor. The method of laser integral fluorescence was used for comparison. In this case integral power of fluorescence of human teeth was measured. As a source of probing (stimulated) radiation diode lasers ((lambda) equals655 nm, 0.1 mW and 630 nm, 1 mW) and Ia-Na laser were applied. For registration of signals Si-photodetector was used. Integral power was shown in a digital indicator. Advantages and disadvantages of these methods are described in this research. It is disclosed that the method of laser integral power of fluorescence has the following characteristics: simplicity of construction and schema-technical decisions. However the method of PNC-spectral diagnostics are characterized by considerably more sensitivity in diagnostics of initial caries and capability to differentiate pathologies of various stages (for example, calculus/initial caries). Estimation of spectral characteristics of PNC-signals allows eliminating a number of drawbacks, which are character for detection by method of laser integral fluorescence (for instance, detection of fluorescent fillings, plagues, calculus, discolorations generally, amalgam, gold fillings as if it were caries).

  12. Gender difference of shoulder-pelvic kinematic integration for trunk rotation directions in healthy older adults.

    PubMed

    Sung, Paul S; Danial, Pamela

    2017-12-01

    demonstrated stiffened pelvic rotation and greater shoulder rotation in both directions while the female group demonstrated pelvic stiffness only in the direction from right to left rotation. Clinicians need to consider this directional asymmetry of trunk rotation to enhance integrated shoulder-pelvic coordination in female older adults. A coordinative pattern of different directions of trunk rotation was investigated in healthy older adults. The pelvic range of motion was lesser in the male group compared with the female group. The female group demonstrated pelvic stiffness only in the direction from right to left rotation, while the male group demonstrated pelvic stiffness in both directions. Clinicians need to understand the gender difference of directional coordination as integrated coordination in female older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Integrated Flight and Propulsion Controls for Advanced Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Merrill, Walter; Garg, Sanjay

    1995-01-01

    The research vision of the NASA Lewis Research Center in the area of integrated flight and propulsion controls technologies is described. In particular the Integrated Method for Propulsion and Airframe Controls developed at the Lewis Research Center is described including its application to an advanced aircraft configuration. Additionally, future research directions in integrated controls are described.

  14. Integrated Flight and Propulsion Controls for Advanced Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Merrill, Walter; Garg, Sanjay

    1996-01-01

    The research vision of the NASA Lewis Research Center in the area of integrated flight and propulsion controls technologies is described. In particular, the integrated method for propulsion and airframe controls developed at the Lewis Research Center is described including its application to an advanced aircraft configuration. Additionally, future research directions in integrated controls are described.

  15. Analysis of a novel device-level SINS/ACFSS deeply integrated navigation method

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Qin, Shiqiao; Wang, Xingshu; Jiang, Guangwen; Tan, Wenfeng; Wu, Wei

    2017-02-01

    The combination of the strap-down inertial navigation system(SINS) and the celestial navigation system(CNS) is one of the popular measures to constitute the integrated navigation system. A star sensor(SS) is used as a precise attitude determination device in CNS. To solve the problem that the star image obtained by SS is motion-blurred under dynamic conditions, the attitude-correlated frames(ACF) approach is presented and the star sensor which works based on ACF approach is named ACFSS. Depending on the ACF approach, a novel device-level SINS/ACFSS deeply integrated navigation method is proposed in this paper. Feedback to the ACF process from the error of the gyro is one of the typical characters of the SINS/CNS deeply integrated navigation method. Herein, simulation results have verified its validity and efficiency in improving the accuracy of gyro and it can be proved that this method is feasible.

  16. Integration of e-beam direct write in BEOL processes of 28nm SRAM technology node using mix and match

    NASA Astrophysics Data System (ADS)

    Gutsch, Manuela; Choi, Kang-Hoon; Hanisch, Norbert; Hohle, Christoph; Seidel, Robert; Steidel, Katja; Thrun, Xaver; Werner, Thomas

    2014-10-01

    Many efforts were spent in the development of EUV technologies, but from a customer point of view EUV is still behind expectations. In parallel since years maskless lithography is included in the ITRS roadmap wherein multi electron beam direct patterning is considered as an alternative or complementary approach for patterning of advanced technology nodes. The process of multi beam exposures can be emulated by single beam technologies available in the field. While variable shape-beam direct writers are already used for niche applications, the integration capability of e-beam direct write at advanced nodes has not been proven, yet. In this study the e-beam lithography was implemented in the BEoL processes of the 28nm SRAM technology. Integrated 300mm wafers with a 28nm back-end of line (BEoL) stack from GLOBALFOUNDRIES, Dresden, were used for the experiments. For the patterning of the Metal layer a Mix and Match concept based on the sequence litho - etch - litho - etch (LELE) was developed and evaluated wherein several exposure fields were blanked out during the optical exposure. E-beam patterning results of BEoL Metal and Via layers are presented using a 50kV VISTEC SB3050DW variable shaped electron beam direct writer at Fraunhofer IPMS-CNT. Etch results are shown and compared to the POR. In summary we demonstrate the integration capability of EBDW into a productive CMOS process flow at the example of the 28nm SRAM technology node.

  17. Directional templates for real-time detection of coronal axis rotated faces

    NASA Astrophysics Data System (ADS)

    Perez, Claudio A.; Estevez, Pablo A.; Garate, Patricio

    2004-10-01

    Real-time face and iris detection on video images has gained renewed attention because of multiple possible applications in studying eye function, drowsiness detection, virtual keyboard interfaces, face recognition, video processing and multimedia retrieval. In this paper, a study is presented on using directional templates in the detection of faces rotated in the coronal axis. The templates are built by extracting the directional image information from the regions of the eyes, nose and mouth. The face position is determined by computing a line integral using the templates over the face directional image. The line integral reaches a maximum when it coincides with the face position. It is shown an improvement in localization selectivity by the increased value in the line integral computed with the directional template. Besides, improvements in the line integral value for face size and face rotation angle was also found through the computation of the line integral using the directional template. Based on these results the new templates should improve selectivity and hence provide the means to restrict computations to a fewer number of templates and restrict the region of search during the face and eye tracking procedure. The proposed method is real time, completely non invasive and was applied with no background limitation and normal illumination conditions in an indoor environment.

  18. Purification of crude glycerol from transesterification reaction of palm oil using direct method and multistep method

    NASA Astrophysics Data System (ADS)

    Nasir, N. F.; Mirus, M. F.; Ismail, M.

    2017-09-01

    Crude glycerol which produced from transesterification reaction has limited usage if it does not undergo purification process. It also contains excess methanol, catalyst and soap. Conventionally, purification method of the crude glycerol involves high cost and complex processes. This study aimed to determine the effects of using different purification methods which are direct method (comprises of ion exchange and methanol removal steps) and multistep method (comprises of neutralization, filtration, ion exchange and methanol removal steps). Two crude glycerol samples were investigated; the self-produced sample through the transesterification process of palm oil and the sample obtained from biodiesel plant. Samples were analysed using Fourier Transform Infrared Spectroscopy, Gas Chromatography and High Performance Liquid Chromatography. The results of this study for both samples after purification have showed that the pure glycerol was successfully produced and fatty acid salts were eliminated. Also, the results indicated the absence of methanol in both samples after purification process. In short, the combination of 4 purification steps has contributed to a higher quality of glycerol. Multistep purification method gave a better result compared to the direct method as neutralization and filtration steps helped in removing most excess salt, fatty acid and catalyst.

  19. Method for measuring surface shear stress magnitude and direction using liquid crystal coatings

    NASA Technical Reports Server (NTRS)

    Reda, Daniel C. (Inventor)

    1995-01-01

    A method is provided for determining surface shear magnitude and direction at every point on a surface. The surface is covered with a shear stress sensitive liquid crystal coating and illuminated by white light from a normal direction. A video camera is positioned at an oblique angle above the surface to observe the color of the liquid crystal at that angle. The shear magnitude and direction are derived from the color information. A method of calibrating the device is also provided.

  20. Comparing Methods for Estimating Direct Costs of Adverse Drug Events.

    PubMed

    Gyllensten, Hanna; Jönsson, Anna K; Hakkarainen, Katja M; Svensson, Staffan; Hägg, Staffan; Rehnberg, Clas

    2017-12-01

    To estimate how direct health care costs resulting from adverse drug events (ADEs) and cost distribution are affected by methodological decisions regarding identification of ADEs, assigning relevant resource use to ADEs, and estimating costs for the assigned resources. ADEs were identified from medical records and diagnostic codes for a random sample of 4970 Swedish adults during a 3-month study period in 2008 and were assessed for causality. Results were compared for five cost evaluation methods, including different methods for identifying ADEs, assigning resource use to ADEs, and for estimating costs for the assigned resources (resource use method, proportion of registered cost method, unit cost method, diagnostic code method, and main diagnosis method). Different levels of causality for ADEs and ADEs' contribution to health care resource use were considered. Using the five methods, the maximum estimated overall direct health care costs resulting from ADEs ranged from Sk10,000 (Sk = Swedish krona; ~€1,500 in 2016 values) using the diagnostic code method to more than Sk3,000,000 (~€414,000) using the unit cost method in our study population. The most conservative definitions for ADEs' contribution to health care resource use and the causality of ADEs resulted in average costs per patient ranging from Sk0 using the diagnostic code method to Sk4066 (~€500) using the unit cost method. The estimated costs resulting from ADEs varied considerably depending on the methodological choices. The results indicate that costs for ADEs need to be identified through medical record review and by using detailed unit cost data. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  1. The effects of list-method directed forgetting on recognition memory.

    PubMed

    Benjamin, Aaron S

    2006-10-01

    It is an almost universally accepted claim that the list-method procedure of inducing directed forgetting does not affect recognition. However, previous studies have omitted a critical comparison in reaching this conclusion. This article reports evidence that recognition of material learned after cue presentation is superior for conditions in which the material that preceded cue presentation was designated as to-be-forgotten. Because the absence of an effect of directed-forgetting instructions on recognition is the linchpin of the theoretical claim that retrieval inhibition and not selective rehearsal underlies that effect, the present results call into question the need to postulate a role for inhibition in directed forgetting.

  2. New directions for Artificial Intelligence (AI) methods in optimum design

    NASA Technical Reports Server (NTRS)

    Hajela, Prabhat

    1989-01-01

    Developments and applications of artificial intelligence (AI) methods in the design of structural systems is reviewed. Principal shortcomings in the current approach are emphasized, and the need for some degree of formalism in the development environment for such design tools is underscored. Emphasis is placed on efforts to integrate algorithmic computations in expert systems.

  3. The integration of the motion equations of low-orbiting earth satellites using Taylor's method

    NASA Astrophysics Data System (ADS)

    Krivov, A. V.; Chernysheva, N. A.

    1990-04-01

    A method for the numerical integration of the equations of motion for a satellite is proposed, taking the earth's oblateness and atmospheric drag into account. The method is based on Taylor's representation of the solution to the corresponding polynomial system. The algorithm for choosing the integration step and error estimation is constructed. The method is realized as a subrouting package. The method is applied to a low-orbiting earth satellite and the results are compared with those obtained using Everhart's method.

  4. Mutant fatty acid desaturase and methods for directed mutagenesis

    DOEpatents

    Shanklin, John [Shoreham, NY; Whittle, Edward J [Greenport, NY

    2008-01-29

    The present invention relates to methods for producing fatty acid desaturase mutants having a substantially increased activity towards substrates with fewer than 18 carbon atom chains relative to an unmutagenized precursor desaturase having an 18 carbon chain length specificity, the sequences encoding the desaturases and to the desaturases that are produced by the methods. The present invention further relates to a method for altering a function of a protein, including a fatty acid desaturase, through directed mutagenesis involving identifying candidate amino acid residues, producing a library of mutants of the protein by simultaneously randomizing all amino acid candidates, and selecting for mutants which exhibit the desired alteration of function. Candidate amino acids are identified by a combination of methods. Enzymatic, binding, structural and other functions of proteins can be altered by the method.

  5. Optimizing some 3-stage W-methods for the time integration of PDEs

    NASA Astrophysics Data System (ADS)

    Gonzalez-Pinto, S.; Hernandez-Abreu, D.; Perez-Rodriguez, S.

    2017-07-01

    The optimization of some W-methods for the time integration of time-dependent PDEs in several spatial variables is considered. In [2, Theorem 1] several three-parametric families of three-stage W-methods for the integration of IVPs in ODEs were studied. Besides, the optimization of several specific methods for PDEs when the Approximate Matrix Factorization Splitting (AMF) is used to define the approximate Jacobian matrix (W ≈ fy(yn)) was carried out. Also, some convergence and stability properties were presented [2]. The derived methods were optimized on the base that the underlying explicit Runge-Kutta method is the one having the largest Monotonicity interval among the thee-stage order three Runge-Kutta methods [1]. Here, we propose an optimization of the methods by imposing some additional order condition [7] to keep order three for parabolic PDE problems [6] but at the price of reducing substantially the length of the nonlinear Monotonicity interval of the underlying explicit Runge-Kutta method.

  6. Computing thermal Wigner densities with the phase integration method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Beutier, J.; Borgis, D.; Vuilleumier, R.

    2014-08-28

    We discuss how the Phase Integration Method (PIM), recently developed to compute symmetrized time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)], can be adapted to sampling/generating the thermal Wigner density, a key ingredient, for example, in many approximate schemes for simulating quantum time dependent properties. PIM combines a path integral representation of the density with a cumulant expansion to represent the Wigner function in a form calculable via existing Monte Carlo algorithms for sampling noisy probability densities. The method is able to capture highly non-classical effects such as correlation among the momenta andmore » coordinates parts of the density, or correlations among the momenta themselves. By using alternatives to cumulants, it can also indicate the presence of negative parts of the Wigner density. Both properties are demonstrated by comparing PIM results to those of reference quantum calculations on a set of model problems.« less

  7. Improving Allergen Prediction in Main Crops Using a Weighted Integrative Method.

    PubMed

    Li, Jing; Wang, Jing; Li, Jing

    2017-12-01

    As a public health problem, food allergy is frequently caused by food allergy proteins, which trigger a type-I hypersensitivity reaction in the immune system of atopic individuals. The food allergens in our daily lives are mainly from crops including rice, wheat, soybean and maize. However, allergens in these main crops are far from fully uncovered. Although some bioinformatics tools or methods predicting the potential allergenicity of proteins have been proposed, each method has their limitation. In this paper, we built a novel algorithm PREAL W , which integrated PREAL, FAO/WHO criteria and motif-based method by a weighted average score, to benefit the advantages of different methods. Our results illustrated PREAL W has better performance significantly in the crops' allergen prediction. This integrative allergen prediction algorithm could be useful for critical food safety matters. The PREAL W could be accessed at http://lilab.life.sjtu.edu.cn:8080/prealw .

  8. A boundary integral method for numerical computation of radar cross section of 3D targets using hybrid BEM/FEM with edge elements

    NASA Astrophysics Data System (ADS)

    Dodig, H.

    2017-11-01

    This contribution presents the boundary integral formulation for numerical computation of time-harmonic radar cross section for 3D targets. Method relies on hybrid edge element BEM/FEM to compute near field edge element coefficients that are associated with near electric and magnetic fields at the boundary of the computational domain. Special boundary integral formulation is presented that computes radar cross section directly from these edge element coefficients. Consequently, there is no need for near-to-far field transformation (NTFFT) which is common step in RCS computations. By the end of the paper it is demonstrated that the formulation yields accurate results for canonical models such as spheres, cubes, cones and pyramids. Method has demonstrated accuracy even in the case of dielectrically coated PEC sphere at interior resonance frequency which is common problem for computational electromagnetic codes.

  9. Element Library for Three-Dimensional Stress Analysis by the Integrated Force Method

    NASA Technical Reports Server (NTRS)

    Kaljevic, Igor; Patnaik, Surya N.; Hopkins, Dale A.

    1996-01-01

    The Integrated Force Method, a recently developed method for analyzing structures, is extended in this paper to three-dimensional structural analysis. First, a general formulation is developed to generate the stress interpolation matrix in terms of complete polynomials of the required order. The formulation is based on definitions of the stress tensor components in term of stress functions. The stress functions are written as complete polynomials and substituted into expressions for stress components. Then elimination of the dependent coefficients leaves the stress components expressed as complete polynomials whose coefficients are defined as generalized independent forces. Such derived components of the stress tensor identically satisfy homogenous Navier equations of equilibrium. The resulting element matrices are invariant with respect to coordinate transformation and are free of spurious zero-energy modes. The formulation provides a rational way to calculate the exact number of independent forces necessary to arrive at an approximation of the required order for complete polynomials. The influence of reducing the number of independent forces on the accuracy of the response is also analyzed. The stress fields derived are used to develop a comprehensive finite element library for three-dimensional structural analysis by the Integrated Force Method. Both tetrahedral- and hexahedral-shaped elements capable of modeling arbitrary geometric configurations are developed. A number of examples with known analytical solutions are solved by using the developments presented herein. The results are in good agreement with the analytical solutions. The responses obtained with the Integrated Force Method are also compared with those generated by the standard displacement method. In most cases, the performance of the Integrated Force Method is better overall.

  10. Structure analysis of polymerized phospholipid bilayer by TED and direct methods.

    PubMed

    Stevens, M; Longo, M; Dorset, D L; Spence, J

    2002-04-01

    This paper describes the use of elastic energy filtered transmission electron diffraction combined with Direct Methods in order to study the structure of thin Langmuir-Blodgett films of a radiation sensitive diacetylene polymer (DC8.9PC). We obtain a potential map for one projection by direct phasing of zone axis patterns, and discuss experimental problems and possible solutions.

  11. Integrable flows between exact CFTs

    NASA Astrophysics Data System (ADS)

    Georgiou, George; Sfetsos, Konstantinos

    2017-11-01

    We explicitly construct families of integrable σ-model actions smoothly inter-polating between exact CFTs. In the ultraviolet the theory is the direct product of two current algebras at levels k 1 and k 2. In the infrared and for the case of two deformation matrices the CFT involves a coset CFT, whereas for a single matrix deformation it is given by the ultraviolet direct product theories but at levels k 1 and k 2 - k 1. For isotropic deformations we demonstrate integrability. In this case we also compute the exact beta-function for the deformation parameters using gravitational methods. This is shown to coincide with previous results obtained using perturbation theory and non-perturbative symmetries.

  12. The evolution of phenotypic integration: How directional selection reshapes covariation in mice

    PubMed Central

    Penna, Anna; Melo, Diogo; Bernardi, Sandra; Oyarzabal, Maria Inés; Marroig, Gabriel

    2017-01-01

    Abstract Variation is the basis for evolution, and understanding how variation can evolve is a central question in biology. In complex phenotypes, covariation plays an even more important role, as genetic associations between traits can bias and alter evolutionary change. Covariation can be shaped by complex interactions between loci, and this genetic architecture can also change during evolution. In this article, we analyzed mouse lines experimentally selected for changes in size to address the question of how multivariate covariation changes under directional selection, as well as to identify the consequences of these changes to evolution. Selected lines showed a clear restructuring of covariation in their cranium and, instead of depleting their size variation, these lines increased their magnitude of integration and the proportion of variation associated with the direction of selection. This result is compatible with recent theoretical works on the evolution of covariation that take the complexities of genetic architecture into account. This result also contradicts the traditional view of the effects of selection on available covariation and suggests a much more complex view of how populations respond to selection. PMID:28685813

  13. Directions of development of road in terms of interregional integration in Russia

    NASA Astrophysics Data System (ADS)

    Seleznev, Alexander; Mottaeva, Angela; Andreeva, Larisa; Izmaylova, Svetlana

    2017-10-01

    The article is aimed at disclosure of the theoretical foundations of the development of transport infrastructure in the region. Sustainable transport and transport links allow to determine the direction of development of modern economy in the regions. Ensuring the availability of strategically important resources for many economic entities is one of the priorities of economic development of regions. the article presents the author’s approach to determination of perspective directions of development of relations of economic systems of regions and regional infrastructure. Important role in the processes of spatial integration of the regions transport infrastructure plays, which, on the one hand, determines the level of development of intra-regional production of goods and services, the availability of social welfare for the entire population, on the other hand, helps to establish strong intra-regional ties, thereby bringing together the socio-economic situation of neighbouring regions. Technological solutions for the transportation may be different in Russia, the developed network of Railways, efficiently functioning system of inter-regional pipelines, experiencing a rebirth water transport, however, a special place is occupied by road transportation.

  14. Outcome of the First wwPDB Hybrid/Integrative Methods Task Force Workshop

    PubMed Central

    Sali, Andrej; Berman, Helen M.; Schwede, Torsten; Trewhella, Jill; Kleywegt, Gerard; Burley, Stephen K.; Markley, John; Nakamura, Haruki; Adams, Paul; Bonvin, Alexandre M.J.J.; Chiu, Wah; Dal Peraro, Matteo; Di Maio, Frank; Ferrin, Thomas E.; Grünewald, Kay; Gutmanas, Aleksandras; Henderson, Richard; Hummer, Gerhard; Iwasaki, Kenji; Johnson, Graham; Lawson, Catherine L.; Meiler, Jens; Marti-Renom, Marc A.; Montelione, Gaetano T.; Nilges, Michael; Nussinov, Ruth; Patwardhan, Ardan; Rappsilber, Juri; Read, Randy J.; Saibil, Helen; Schröder, Gunnar F.; Schwieters, Charles D.; Seidel, Claus A. M.; Svergun, Dmitri; Topf, Maya; Ulrich, Eldon L.; Velankar, Sameer; Westbrook, John D.

    2016-01-01

    Summary Structures of biomolecular systems are increasingly computed by integrative modeling that relies on varied types of experimental data and theoretical information. We describe here the proceedings and conclusions from the first wwPDB Hybrid/Integrative Methods Task Force Workshop held at the European Bioinformatics Institute in Hinxton, UK, October 6 and 7, 2014. At the workshop, experts in various experimental fields of structural biology, experts in integrative modeling and visualization, and experts in data archiving addressed a series of questions central to the future of structural biology. How should integrative models be represented? How should the data and integrative models be validated? What data should be archived? How should the data and models be archived? What information should accompany the publication of integrative models? PMID:26095030

  15. Characteristics of Interruptions During Medication Administration:An Integrative Review of Direct Observational Studies.

    PubMed

    Schroers, Ginger

    2018-06-26

    The purpose of this review was to synthesize and summarize data gathered by direct observation of the characteristics of interruptions in the context of nursing medication administration in hospital settings. Interruptions are prevalent during the medication administration process performed by nurses in hospital settings and have been found to be associated with an increase in frequency and severity of nursing medication administration errors. In addition, interruptions decrease task efficiency, leading to longer medication administration completion times. Integrative review. The electronic databases Cumulative Index of Nursing and Allied Health Literature (CINAHL), PubMED, PsyARTICLES, and Google Scholar were searched using the terms "interruptions" AND "medication administration" AND "direct observation". Nine articles met the inclusion criteria. Interruptions are likely to occur at least once during nursing medication administration processes in hospital settings. This finding applies to medication administered to one patient, termed a medication pass, and medication administered to multiple patients, termed a mediation round. Interruptions are most commonly caused by another nurse, staff member, or are self-initiated, and last approximately one minute in length. A raised awareness among staff of the most common sources of interruptions may encourage changes that lead to a decrease in the occurrence of interruptions. In addition, nurse leaders can apply an understanding of the common characteristics of interruptions to guide research, policies, and educational methods aimed at interruption management strategies. The findings from this review can be used to guide the identification and development of targeted interventions and strategies that would have the most substantial impact to reduce and manage interruptions during medication administration. Interruption management strategies have the potential to lead to a decrease in medication errors and an increase in

  16. DELINEATION OF SUBSURFACE HYDROCARBON CONTAMINANT DISTRIBUTION USING A DIRECT PUSH RESISTIVITY METHOD

    EPA Science Inventory

    A direct push resistivity method was evaluated as a complementary screening tool to provide rapid in-situ contaminant detection to aid in better defining locations for drilling, sampling, and monitoring well installation at hazardous waste sites. Nine continuous direct push resi...

  17. [Laboratory diagnosis of genital herpes--direct immunofluorescence method].

    PubMed

    Majewska, Anna; Romejko-Wolniewicz, Ewa; Zareba-Szczudlik, Julia; Kilijańczyk, Marek; Gajewska, Małgorzata; Młynarczyk, Grazyna

    2013-07-01

    Aim of the study was to determine clinical usefulness of direct immunofluorescence method in the laboratory diagnosis of genital herpes in women. Overall 187 anogenital swabs were collected from 120 women. Using a dacron-tipped applicator 83 swabs were collected from women suspected of genital herpes and 104 from patients with no signs of genital infection. All samples were tested using cell culture (Vero cell line) and then direct immunofluorescence method (DIF) for the identification of antigens of herpes simplex viruses: HSV-1 and HSV-2. Characteristic cytopathic effect (CPE), indicative of alphaherpesvirus infection, was observed in 43.4% of cultures with clinical specimens collected from women with suspected genital herpes and in 29.8% of cultures of clinical specimens taken from patients with no clinical symptoms of genital herpes. Herpes simplex viruses were determined in 73 samples by direct immunofluorescence method after amplification of the virus in cell culture. The DIF test confirmed the diagnosis based on the microscopic CPE observation in 85%. In 15% of samples (taken from pregnant women without clinical signs of infection) we reported positive immunofluorescence in the absence of CPE. The frequency of antigen detection was statistically significantly higher in samples that were positive by culture study (chi-square test with Yates's correction, p < 0.01). This method proved to be highly sensitive (97%) in women with clinically suspected infection. High negative predictive value (99%) proves the clinical utility of the DIF in these group of patients. In asymptomatic infections, viral antigens were detected most frequently in the swabs from the cervical canal, and in cases of suspected genital herpes in swabs taken from the vestibule of the vagina and the vulva. However, there was no statistically significant difference in the frequency of detection of Herpes Simplex Virus antigens in specimens from different parts of the genital tract in both groups

  18. Prospects for direct social perception: a multi-theoretical integration to further the science of social cognition

    PubMed Central

    Wiltshire, Travis J.; Lobato, Emilio J. C.; McConnell, Daniel S.; Fiore, Stephen M.

    2015-01-01

    In this paper we suggest that differing approaches to the science of social cognition mirror the arguments between radical embodied and traditional approaches to cognition. We contrast the use in social cognition of theoretical inference and mental simulation mechanisms with approaches emphasizing a direct perception of others’ mental states. We build from a recent integrative framework unifying these divergent perspectives through the use of dual-process theory and supporting social neuroscience research. Our elaboration considers two complementary notions of direct perception: one primarily stemming from ecological psychology and the other from enactive cognition theory. We use this as the foundation from which to offer an account of the informational basis for social information and assert a set of research propositions to further the science of social cognition. In doing so, we point out how perception of the minds of others can be supported in some cases by lawful information, supporting direct perception of social affordances and perhaps, mental states, and in other cases by cues that support indirect perceptual inference. Our goal is to extend accounts of social cognition by integrating advances across disciplines to provide a multi-level and multi-theoretic description that can advance this field and offer a means through which to reconcile radical embodied and traditional approaches to cognitive neuroscience. PMID:25709572

  19. Pattern recognition methods and air pollution source identification. [based on wind direction

    NASA Technical Reports Server (NTRS)

    Leibecki, H. F.; King, R. B.

    1978-01-01

    Directional air samplers, used for resolving suspended particulate matter on the basis of time and wind direction were used to assess the feasibility of characterizing and identifying emission source types in urban multisource environments. Filters were evaluated for 16 elements and X-ray fluorescence methods yielded elemental concentrations for direction, day, and the interaction of direction and day. Large numbers of samples are necessary to compensate for large day-to-day variations caused by wind perturbations and/or source changes.

  20. Method to directly radiolabel antibodies for diagnostic imaging and therapy

    DOEpatents

    Thakur, Mathew L.

    1994-01-01

    The invention is a novel method and kit for directly radiolabeling proteins such as antibodies or antibody fragments for diagnostic and therapeutic purposes. The method comprises incubating a protein-containing solution with a solution of sodium ascorbate; adding a required quantity of reduced radionuclide to the incubated protein. A kit is also provided wherein the protein and/or reducing agents may be in lyophilized form.

  1. Method to directly radiolabel antibodies for diagnostic imaging and therapy

    DOEpatents

    Thakur, Mathew L.

    1991-01-01

    The invention is a novel method and kit for directly radiolabeling proteins such as antibodies or antibody fragments for diagnostic and therapeutic purposes. The method comprises incubating a protein-containing solution with a solution of sodium ascorbate; adding a required quantity of reduced radionuclide to the incubated protein. A kit is also provided wherein the protein and/or reducing agents may be in lyophilized form.

  2. The iso-response method: measuring neuronal stimulus integration with closed-loop experiments

    PubMed Central

    Gollisch, Tim; Herz, Andreas V. M.

    2012-01-01

    Throughout the nervous system, neurons integrate high-dimensional input streams and transform them into an output of their own. This integration of incoming signals involves filtering processes and complex non-linear operations. The shapes of these filters and non-linearities determine the computational features of single neurons and their functional roles within larger networks. A detailed characterization of signal integration is thus a central ingredient to understanding information processing in neural circuits. Conventional methods for measuring single-neuron response properties, such as reverse correlation, however, are often limited by the implicit assumption that stimulus integration occurs in a linear fashion. Here, we review a conceptual and experimental alternative that is based on exploring the space of those sensory stimuli that result in the same neural output. As demonstrated by recent results in the auditory and visual system, such iso-response stimuli can be used to identify the non-linearities relevant for stimulus integration, disentangle consecutive neural processing steps, and determine their characteristics with unprecedented precision. Automated closed-loop experiments are crucial for this advance, allowing rapid search strategies for identifying iso-response stimuli during experiments. Prime targets for the method are feed-forward neural signaling chains in sensory systems, but the method has also been successfully applied to feedback systems. Depending on the specific question, “iso-response” may refer to a predefined firing rate, single-spike probability, first-spike latency, or other output measures. Examples from different studies show that substantial progress in understanding neural dynamics and coding can be achieved once rapid online data analysis and stimulus generation, adaptive sampling, and computational modeling are tightly integrated into experiments. PMID:23267315

  3. Methods for determining infrasound phase velocity direction with an array of line sensors.

    PubMed

    Walker, Kristoffer T; Zumberge, Mark A; Hedlin, Michael A H; Shearer, Peter M

    2008-10-01

    Infrasound arrays typically consist of several microbarometers separated by distances that provide predictable signal time separations, forming the basis for processing techniques that estimate the phase velocity direction. The directional resolution depends on the noise level and is proportional to the number of these point sensors; additional sensors help attenuate noise and improve direction resolution. An alternative approach is to form an array of directional line sensors, each of which emulates a line of many microphones that instantaneously integrate pressure change. The instrument response is a function of the orientation of the line with respect to the signal wavefront. Real data recorded at the Piñon Flat Observatory in southern California and synthetic data show that this spectral property can be exploited with multiple line sensors to determine the phase velocity direction with a precision comparable to a larger aperture array of microbarometers. Three types of instrument-response-dependent beamforming and an array deconvolution technique are evaluated. The results imply that an array of five radial line sensors, with equal azimuthal separation and an aperture that depends on the frequency band of interest, provides directional resolution while requiring less space compared to an equally effective array of five microbarometers with rosette wind filters.

  4. Outcome of the First wwPDB Hybrid/Integrative Methods Task Force Workshop.

    PubMed

    Sali, Andrej; Berman, Helen M; Schwede, Torsten; Trewhella, Jill; Kleywegt, Gerard; Burley, Stephen K; Markley, John; Nakamura, Haruki; Adams, Paul; Bonvin, Alexandre M J J; Chiu, Wah; Peraro, Matteo Dal; Di Maio, Frank; Ferrin, Thomas E; Grünewald, Kay; Gutmanas, Aleksandras; Henderson, Richard; Hummer, Gerhard; Iwasaki, Kenji; Johnson, Graham; Lawson, Catherine L; Meiler, Jens; Marti-Renom, Marc A; Montelione, Gaetano T; Nilges, Michael; Nussinov, Ruth; Patwardhan, Ardan; Rappsilber, Juri; Read, Randy J; Saibil, Helen; Schröder, Gunnar F; Schwieters, Charles D; Seidel, Claus A M; Svergun, Dmitri; Topf, Maya; Ulrich, Eldon L; Velankar, Sameer; Westbrook, John D

    2015-07-07

    Structures of biomolecular systems are increasingly computed by integrative modeling that relies on varied types of experimental data and theoretical information. We describe here the proceedings and conclusions from the first wwPDB Hybrid/Integrative Methods Task Force Workshop held at the European Bioinformatics Institute in Hinxton, UK, on October 6 and 7, 2014. At the workshop, experts in various experimental fields of structural biology, experts in integrative modeling and visualization, and experts in data archiving addressed a series of questions central to the future of structural biology. How should integrative models be represented? How should the data and integrative models be validated? What data should be archived? How should the data and models be archived? What information should accompany the publication of integrative models? Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Direct estimation of diffuse gaseous emissions from coal fires: current methods and future directions

    USGS Publications Warehouse

    Engle, Mark A.; Olea, Ricardo A.; O'Keefe, Jennifer M. K.; Hower, James C.; Geboy, Nicholas J.

    2013-01-01

    Coal fires occur in nature spontaneously, contribute to increases in greenhouse gases, and emit atmospheric toxicants. Increasing interest in quantifying coal fire emissions has resulted in the adaptation and development of specialized approaches and adoption of numerical modeling techniques. Overview of these methods for direct estimation of diffuse gas emissions from coal fires is presented in this paper. Here we take advantage of stochastic Gaussian simulation to interpolate CO2 fluxes measured using a dynamic closed chamber at the Ruth Mullins coal fire in Perry County, Kentucky. This approach allows for preparing a map of diffuse gas emissions, one of the two primary ways that gases emanate from coal fires, and establishing the reliability of the study both locally and for the entire fire. Future research directions include continuous and automated sampling to improve quantification of gaseous coal fire emissions.

  6. Volterra integral equation-factorisation method and nucleus-nucleus elastic scattering

    NASA Astrophysics Data System (ADS)

    Laha, U.; Majumder, M.; Bhoi, J.

    2018-04-01

    An approximate solution for the nuclear Hulthén plus atomic Hulthén potentials is constructed by solving the associated Volterra integral equation by series substitution method. Within the framework of supersymmetry-inspired factorisation method, this solution is exploited to construct higher partial wave interactions. The merit of our approach is examined by computing elastic scattering phases of the α {-}α system by the judicious use of phase function method. Reasonable agreements in phase shifts are obtained with standard data.

  7. The Integral Theory System Questionnaire: an anatomically directed questionnaire to determine pelvic floor dysfunctions in women.

    PubMed

    Wagenlehner, Florian Martin Erich; Fröhlich, Oliver; Bschleipfer, Thomas; Weidner, Wolfgang; Perletti, Gianpaolo

    2014-06-01

    Anatomical damage to pelvic floor structures may cause multiple symptoms. The Integral Theory System Questionnaire (ITSQ) is a holistic questionnaire that uses symptoms to help locate damage in specific connective tissue structures as a guide to reconstructive surgery. It is based on the integral theory, which states that pelvic floor symptoms and prolapse are both caused by lax suspensory ligaments. The aim of the present study was to psychometrically validate the ITSQ. Established psychometric properties including validity, reliability, and responsiveness were considered for evaluation. Criterion validity was assessed in a cohort of 110 women with pelvic floor dysfunctions by analyzing the correlation of questionnaire responses with objective clinical data. Test-retest was performed with questionnaires from 47 patients. Cronbach's alpha and "split-half" reliability coefficients were calculated for inner consistency analysis. Psychometric properties of ITSQ were comparable to the ones of previously validated Pelvic Floor Questionnaires. Face validity and content validity were approved by an expert group of the International Collaboration of Pelvic Floor surgeons. Convergent validity assessed using Bayesian method was at least as accurate as the expert assessment of anatomical defects. Objective data measurement in patients demonstrated significant correlations with ITSQ domains fulfilling criterion validity. Internal consistency values ranked from 0.85 to 0.89 in different scenarios. The ITSQ proofed accurate and is able to serve as a holistic Pelvic Floor Questionnaire directing symptoms to site-specific pelvic floor reconstructive surgery.

  8. An accuracy measurement method for star trackers based on direct astronomic observation

    PubMed Central

    Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

    2016-01-01

    Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers. PMID:26948412

  9. An accuracy measurement method for star trackers based on direct astronomic observation.

    PubMed

    Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

    2016-03-07

    Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.

  10. The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tumino, A.; Gulino, M.; Spitaleri, C.

    2014-05-09

    The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent resultsmore » will be presented to demonstrate how THM works experimentally.« less

  11. Securing Digital Images Integrity using Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Hajji, Tarik; Itahriouan, Zakaria; Ouazzani Jamil, Mohammed

    2018-05-01

    Digital image signature is a technique used to protect the image integrity. The application of this technique can serve several areas of imaging applied to smart cities. The objective of this work is to propose two methods to protect digital image integrity. We present a description of two approaches using artificial neural networks (ANN) to digitally sign an image. The first one is “Direct Signature without learning” and the second is “Direct Signature with learning”. This paper presents the theory of proposed approaches and an experimental study to test their effectiveness.

  12. A Preliminary Investigation of the Direct Standard Setting Method.

    ERIC Educational Resources Information Center

    Jones, J. Patrick; And Others

    Three studies assessed the psychometric characteristics of the Direct Standard Setting Method (DSSM). The Angoff technique was also used in each study. The DSSM requires judges to consider an examination 10 items at a time and determine the minimum items in that set a candidate should answer correctly to receive the credential. Nine judges set a…

  13. Neutron skyshine calculations with the integral line-beam method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gui, A.A.; Shultis, J.K.; Faw, R.E.

    1997-10-01

    Recently developed line- and conical-beam response functions are used to calculate neutron skyshine doses for four idealized source geometries. These calculations, which can serve as benchmarks, are compared with MCNP calculations, and the excellent agreement indicates that the integral conical- and line-beam method is an effective alternative to more computationally expensive transport calculations.

  14. Promising Perceptions, Divergent Practices and Barriers to Integrated Malaria Prevention in Wakiso District, Uganda: A Mixed Methods Study

    PubMed Central

    Musoke, David; Miiro, George; Karani, George; Morris, Keith; Kasasa, Simon; Ndejjo, Rawlance; Nakiyingi-Miiro, Jessica; Guwatudde, David; Musoke, Miph Boses

    2015-01-01

    Background The World Health Organization recommends use of multiple approaches to control malaria. The integrated approach to malaria prevention advocates the use of several malaria prevention methods in a holistic manner. This study assessed perceptions and practices on integrated malaria prevention in Wakiso district, Uganda. Methods A clustered cross-sectional survey was conducted among 727 households from 29 villages using both quantitative and qualitative methods. Assessment was done on awareness of various malaria prevention methods, potential for use of the methods in a holistic manner, and reasons for dislike of certain methods. Households were classified as using integrated malaria prevention if they used at least two methods. Logistic regression was used to test for factors associated with the use of integrated malaria prevention while adjusting for clustering within villages. Results Participants knew of the various malaria prevention methods in the integrated approach including use of insecticide treated nets (97.5%), removing mosquito breeding sites (89.1%), clearing overgrown vegetation near houses (97.9%), and closing windows and doors early in the evenings (96.4%). If trained, most participants (68.6%) would use all the suggested malaria prevention methods of the integrated approach. Among those who would not use all methods, the main reasons given were there being too many (70.2%) and cost (32.0%). Only 33.0% households were using the integrated approach to prevent malaria. Use of integrated malaria prevention by households was associated with reading newspapers (AOR 0.34; 95% CI 0.22 –0.53) and ownership of a motorcycle/car (AOR 1.75; 95% CI 1.03 – 2.98). Conclusion Although knowledge of malaria prevention methods was high and perceptions on the integrated approach promising, practices on integrated malaria prevention was relatively low. The use of the integrated approach can be improved by promoting use of multiple malaria prevention methods

  15. 3-D ultrasound volume reconstruction using the direct frame interpolation method.

    PubMed

    Scheipers, Ulrich; Koptenko, Sergei; Remlinger, Rachel; Falco, Tony; Lachaine, Martin

    2010-11-01

    A new method for 3-D ultrasound volume reconstruction using tracked freehand 3-D ultrasound is proposed. The method is based on solving the forward volume reconstruction problem using direct interpolation of high-resolution ultrasound B-mode image frames. A series of ultrasound B-mode image frames (an image series) is acquired using the freehand scanning technique and position sensing via optical tracking equipment. The proposed algorithm creates additional intermediate image frames by directly interpolating between two or more adjacent image frames of the original image series. The target volume is filled using the original frames in combination with the additionally constructed frames. Compared with conventional volume reconstruction methods, no additional filling of empty voxels or holes within the volume is required, because the whole extent of the volume is defined by the arrangement of the original and the additionally constructed B-mode image frames. The proposed direct frame interpolation (DFI) method was tested on two different data sets acquired while scanning the head and neck region of different patients. The first data set consisted of eight B-mode 2-D frame sets acquired under optimal laboratory conditions. The second data set consisted of 73 image series acquired during a clinical study. Sample volumes were reconstructed for all 81 image series using the proposed DFI method with four different interpolation orders, as well as with the pixel nearest-neighbor method using three different interpolation neighborhoods. In addition, volumes based on a reduced number of image frames were reconstructed for comparison of the different methods' accuracy and robustness in reconstructing image data that lies between the original image frames. The DFI method is based on a forward approach making use of a priori information about the position and shape of the B-mode image frames (e.g., masking information) to optimize the reconstruction procedure and to reduce

  16. [Expression of human-mouse chimeric antibody directed against Chikungunya virus with site-specific integration system].

    PubMed

    Li, Jian-min; Chen, Wei; Jia, Xiu-jie; An, Xiao-ping; Li, Bing; Fan, Ying-ru; Tong, Yi-gang

    2005-05-01

    To obtain CHO/dhfr(-) cells line with integrated FRT sequence in the chromosome transcription active site and to express human-mouse chimeric antibody directed against Chikungunya Virus by using the cell line. The fusion gene of FRT and HBsAg was constructed by PCR and cloned into the MCS of pCI-neo to construct pCI-FRT-HBsAg. The pCI-FRT-HBsAg was transfected into CHO/dhfr(-) cells and cell clones with high expression of HBsAg were screened by detecting the amount of HBsAg with ELISA. A CHO cell clone with the highest expression was chosen and named as CHO/dhfr(-) FRT(+). pAFRT HFLF, a expression plasmid of chimeric antibody with RFT sequence was transfected into CHO/dhfr(-) FRT(+) cells and cell clones with high expression of the chimeric antibody were screened by increasing concentration of MTX. A CHO cell clone with high expression of the chimeric antibody was cultured in large scale and supernatant was collected from which the chimeric antibody was purified. The purified chimeric antibody was analyzed by SDS-PAGE, Western blot and IFA. A CHO/dhfr(-) cells line with integrated FRT sequence in the chromosome transcription active site was obtained successfully. A cell clone with yield of 5 mg/L of chimeric antibody was obtained, as compared with routine CHO cell expression system with a yield of 2 mg/L. A cell line with integrated FRT sequence in the chromosome transcription active site was obtained and with it human-mouse chimeric antibody directed against Chikungunya virus was expressed. This system lays a solid foundation which can be used for expressing antibodies and other proteins.

  17. Directed forgetting of complex pictures in an item method paradigm.

    PubMed

    Hauswald, Anne; Kissler, Johanna

    2008-11-01

    An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect--that is, better recognition of "to-be-remembered" than of "to-be-forgotten" pictures--was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants' depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.

  18. Alternating direction implicit methods for parabolic equations with a mixed derivative

    NASA Technical Reports Server (NTRS)

    Beam, R. M.; Warming, R. F.

    1980-01-01

    Alternating direction implicit (ADI) schemes for two-dimensional parabolic equations with a mixed derivative are constructed by using the class of all A(0)-stable linear two-step methods in conjunction with the method of approximate factorization. The mixed derivative is treated with an explicit two-step method which is compatible with an implicit A(0)-stable method. The parameter space for which the resulting ADI schemes are second-order accurate and unconditionally stable is determined. Some numerical examples are given.

  19. Alternating direction implicit methods for parabolic equations with a mixed derivative

    NASA Technical Reports Server (NTRS)

    Beam, R. M.; Warming, R. F.

    1979-01-01

    Alternating direction implicit (ADI) schemes for two-dimensional parabolic equations with a mixed derivative are constructed by using the class of all A sub 0-stable linear two-step methods in conjunction with the method of approximation factorization. The mixed derivative is treated with an explicit two-step method which is compatible with an implicit A sub 0-stable method. The parameter space for which the resulting ADI schemes are second order accurate and unconditionally stable is determined. Some numerical examples are given.

  20. Evaluation of the direct and diffusion methods for the determination of fluoride content in table salt

    PubMed Central

    Martínez-Mier, E. Angeles; Soto-Rojas, Armando E.; Buckley, Christine M.; Margineda, Jorge; Zero, Domenick T.

    2010-01-01

    Objective The aim of this study was to assess methods currently used for analyzing fluoridated salt in order to identify the most useful method for this type of analysis. Basic research design Seventy-five fluoridated salt samples were obtained. Samples were analyzed for fluoride content, with and without pretreatment, using direct and diffusion methods. Element analysis was also conducted in selected samples. Fluoride was added to ultra pure NaCl and non-fluoridated commercial salt samples and Ca and Mg were added to fluoride samples in order to assess fluoride recoveries using modifications to the methods. Results Larger amounts of fluoride were found and recovered using diffusion than direct methods (96%–100% for diffusion vs. 67%–90% for direct). Statistically significant differences were obtained between direct and diffusion methods using different ion strength adjusters. Pretreatment methods reduced the amount of recovered fluoride. Determination of fluoride content was influenced both by the presence of NaCl and other ions in the salt. Conclusion Direct and diffusion techniques for analysis of fluoridated salt are suitable methods for fluoride analysis. The choice of method should depend on the purpose of the analysis. PMID:20088217

  1. A Systematic Method of Integrating BIM and Sensor Technology for Sustainable Construction Design

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Deng, Zhiyu

    2017-10-01

    Building Information Modeling (BIM) has received lots of attention of construction field, and sensor technology was applied in construction data collection. This paper developed a method to integrate BIM and sensor technology for sustainable construction design. A brief literature review was conducted to clarify the current development of BIM and sensor technology; then a systematic method for integrating BIM and sensor technology to realize sustainable construction design was put forward; finally a brief discussion and conclusion was given.

  2. On time discretizations for spectral methods. [numerical integration of Fourier and Chebyshev methods for dynamic partial differential equations

    NASA Technical Reports Server (NTRS)

    Gottlieb, D.; Turkel, E.

    1980-01-01

    New methods are introduced for the time integration of the Fourier and Chebyshev methods of solution for dynamic differential equations. These methods are unconditionally stable, even though no matrix inversions are required. Time steps are chosen by accuracy requirements alone. For the Fourier method both leapfrog and Runge-Kutta methods are considered. For the Chebyshev method only Runge-Kutta schemes are tested. Numerical calculations are presented to verify the analytic results. Applications to the shallow water equations are presented.

  3. Carbon storage in Chinese grassland ecosystems: Influence of different integrative methods.

    PubMed

    Ma, Anna; He, Nianpeng; Yu, Guirui; Wen, Ding; Peng, Shunlei

    2016-02-17

    The accurate estimate of grassland carbon (C) is affected by many factors at the large scale. Here, we used six methods (three spatial interpolation methods and three grassland classification methods) to estimate C storage of Chinese grasslands based on published data from 2004 to 2014, and assessed the uncertainty resulting from different integrative methods. The uncertainty (coefficient of variation, CV, %) of grassland C storage was approximately 4.8% for the six methods tested, which was mainly determined by soil C storage. C density and C storage to the soil layer depth of 100 cm were estimated to be 8.46 ± 0.41 kg C m(-2) and 30.98 ± 1.25 Pg C, respectively. Ecosystem C storage was composed of 0.23 ± 0.01 (0.7%) above-ground biomass, 1.38 ± 0.14 (4.5%) below-ground biomass, and 29.37 ± 1.2 (94.8%) Pg C in the 0-100 cm soil layer. Carbon storage calculated by the grassland classification methods (18 grassland types) was closer to the mean value than those calculated by the spatial interpolation methods. Differences in integrative methods may partially explain the high uncertainty in C storage estimates in different studies. This first evaluation demonstrates the importance of multi-methodological approaches to accurately estimate C storage in large-scale terrestrial ecosystems.

  4. A new momentum integral method for approximating bed shear stress

    NASA Astrophysics Data System (ADS)

    Wengrove, M. E.; Foster, D. L.

    2016-02-01

    In nearshore environments, accurate estimation of bed stress is critical to estimate morphologic evolution, and benthic mass transfer fluxes. However, bed shear stress over mobile boundaries in wave environments is notoriously difficult to estimate due to the non-equilibrium boundary layer. Approximating the friction velocity with a traditional logarithmic velocity profile model is common, but an unsteady non-uniform flow field violates critical assumptions in equilibrium boundary layer theory. There have been several recent developments involving stress partitioning through an examination of the momentum transfer contributions that lead to improved estimates of the bed stress. For the case of single vertical profile observations, Mehdi et al. (2014) developed a full momentum integral-based method for steady-unidirectional flow that integrates the streamwise Navier-Stokes equation three times to an arbitrary position within the boundary layer. For the case of two-dimensional velocity observations, Rodriguez-Abudo and Foster (2014) were able to examine the momentum contributions from waves, turbulence and the bedform in a spatial and temporal averaging approach to the Navier-Stokes equations. In this effort, the above methods are combined to resolve the bed shear stress in both short and long wave dominated environments with a highly mobile bed. The confluence is an integral based approach for determining bed shear stress that makes no a-priori assumptions of boundary layer shape and uses just a single velocity profile time series for both the phase dependent case (under waves) and the unsteady case (under solitary waves). The developed method is applied to experimental observations obtained in a full scale laboratory investigation (Oregon State's Large Wave Flume) of the nearbed velocity field over a rippled sediment bed in oscillatory flow using both particle image velocimetry and a profiling acoustic Doppler velocimeter. This method is particularly relevant for

  5. Wavefront control methods for high-contrast integral field spectroscopy

    NASA Astrophysics Data System (ADS)

    Groff, Tyler D.; Mejia Prada, Camilo; Cady, Eric; Rizzo, Maxime J.; Mandell, Avi; Gong, Qian; McElwain, Michael; Zimmerman, Neil; Saxena, Prabal; Guyon, Olivier

    2017-09-01

    Direct Imaging of exoplanets using a coronagraph has become a major field of research both on the ground and in space. Key to the science of direct imaging is the spectroscopic capabilities of the instrument, our ability to fit spectra, and understanding the composition of the observed planets. Direct imaging instruments generally use an integral field spectrograph (IFS), which encodes the spectrum into a two-dimensional image on the detector. This results in more efficient detection and characterization of targets, and the spectral information is critical to achieving detection limits below the speckle floor of the imager. The most mature application of these techniques is at more modest contrast ratios on ground-based telescopes, achieving approximately 5-6 orders of magnitude suppression. In space, where we are attempting to detect Earth-analogs, the contrast requirements are more severe and the IFS must be incorporated into the wavefront control loop to reach 1e-10 detection limits required for Earth-like planet detection. We present the objectives and application of IFS imagery for both a speckle control loop and post-processing of images. Results, tested methodologies, and the future work using the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) and the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) at the JPL High Contrast Imaging Testbed are presented.

  6. A new method for true and spurious eigensolutions of arbitrary cavities using the combined Helmholtz exterior integral equation formulation method.

    PubMed

    Chen, I L; Chen, J T; Kuo, S R; Liang, M T

    2001-03-01

    Integral equation methods have been widely used to solve interior eigenproblems and exterior acoustic problems (radiation and scattering). It was recently found that the real-part boundary element method (BEM) for the interior problem results in spurious eigensolutions if the singular (UT) or the hypersingular (LM) equation is used alone. The real-part BEM results in spurious solutions for interior problems in a similar way that the singular integral equation (UT method) results in fictitious solutions for the exterior problem. To solve this problem, a Combined Helmholtz Exterior integral Equation Formulation method (CHEEF) is proposed. Based on the CHEEF method, the spurious solutions can be filtered out if additional constraints from the exterior points are chosen carefully. Finally, two examples for the eigensolutions of circular and rectangular cavities are considered. The optimum numbers and proper positions for selecting the points in the exterior domain are analytically studied. Also, numerical experiments were designed to verify the analytical results. It is worth pointing out that the nodal line of radiation mode of a circle can be rotated due to symmetry, while the nodal line of the rectangular is on a fixed position.

  7. Direct runoff assessment using modified SME method in catchments in the Upper Vistula River Basin

    NASA Astrophysics Data System (ADS)

    Wałęga, A.; Rutkowska, A.; Grzebinoga, M.

    2017-04-01

    Correct determination of direct runoff is crucial for proper and safe dimensioning of hydroengineering structures. It is commonly assessed using SCS-CN method developed in the United States. However, due to deficiencies of this method, many improvements and modifications have been proposed. In this paper, a modified Sahu-Mishra-Eldo (SME) method was introduced and tested for three catchments located in the upper Vistula basin. Modification of SME method involved a determination of maximum potential retention S based on CN parameter derived from SCS-CN method. The modified SME method yielded direct runoff values very similar to those observed in the investigated catchments. Moreover, it generated significantly smaller errors in the direct runoff estimation as compared with SCS-CN and SME methods in the analyzed catchments. This approach may be used for estimating the runoff in uncontrolled catchments.

  8. Integral processing in beyond-Hartree-Fock calculations

    NASA Technical Reports Server (NTRS)

    Taylor, P. R.

    1986-01-01

    The increasing rate at which improvements in processing capacity outstrip improvements in input/output performance of large computers has led to recent attempts to bypass generation of a disk-based integral file. The direct self-consistent field (SCF) method of Almlof and co-workers represents a very successful implementation of this approach. This paper is concerned with the extension of this general approach to configuration interaction (CI) and multiconfiguration-self-consistent field (MCSCF) calculations. After a discussion of the particular types of molecular orbital (MO) integrals for which -- at least for most current generation machines -- disk-based storage seems unavoidable, it is shown how all the necessary integrals can be obtained as matrix elements of Coulomb and exchange operators that can be calculated using a direct approach. Computational implementations of such a scheme are discussed.

  9. Method and apparatus for ion mobility spectrometry with alignment of dipole direction (IMS-ADD)

    DOEpatents

    Shvartsburg, Alexandre A [Richland, WA; Tang, Keqi [Richland, WA; Smith, Richard D [Richland, WA

    2007-01-30

    Techniques and instrumentation are described for analyses of substances, including complex samples/mixtures that require separation prior to characterization of individual components. A method is disclosed for separation of ion mixtures and identification of ions, including protein and other macromolecular ions and their different structural isomers. Analyte ions are not free to rotate during the separation, but are substantially oriented with respect to the drift direction. Alignment is achieved by applying, at a particular angle to the drift field, a much stronger alternating electric field that "locks" the ion dipoles with moments exceeding a certain value. That value depends on the buffer gas composition, pressure, and temperature, but may be as low as .about.3 Debye under certain conditions. The presently disclosed method measures the direction-specific cross-sections that provide the structural information complementing that obtained from known methods, and, when coupled to those methods, increases the total peak capacity and specificity of gas-phase separations. Simultaneous 2-D separations by direction-specific cross sections along and orthogonally to the ion dipole direction are also possible.

  10. An O(N) and parallel approach to integral problems by a kernel-independent fast multipole method: Application to polarization and magnetization of interacting particles

    NASA Astrophysics Data System (ADS)

    Jiang, Xikai; Li, Jiyuan; Zhao, Xujun; Qin, Jian; Karpeev, Dmitry; Hernandez-Ortiz, Juan; de Pablo, Juan J.; Heinonen, Olle

    2016-08-01

    Large classes of materials systems in physics and engineering are governed by magnetic and electrostatic interactions. Continuum or mesoscale descriptions of such systems can be cast in terms of integral equations, whose direct computational evaluation requires O(N2) operations, where N is the number of unknowns. Such a scaling, which arises from the many-body nature of the relevant Green's function, has precluded wide-spread adoption of integral methods for solution of large-scale scientific and engineering problems. In this work, a parallel computational approach is presented that relies on using scalable open source libraries and utilizes a kernel-independent Fast Multipole Method (FMM) to evaluate the integrals in O(N) operations, with O(N) memory cost, thereby substantially improving the scalability and efficiency of computational integral methods. We demonstrate the accuracy, efficiency, and scalability of our approach in the context of two examples. In the first, we solve a boundary value problem for a ferroelectric/ferromagnetic volume in free space. In the second, we solve an electrostatic problem involving polarizable dielectric bodies in an unbounded dielectric medium. The results from these test cases show that our proposed parallel approach, which is built on a kernel-independent FMM, can enable highly efficient and accurate simulations and allow for considerable flexibility in a broad range of applications.

  11. Virus-Mimetic Fusogenic Exosomes for Direct Delivery of Integral Membrane Proteins to Target Cell Membranes.

    PubMed

    Yang, Yoosoo; Hong, Yeonsun; Nam, Gi-Hoon; Chung, Jin Hwa; Koh, Eunee; Kim, In-San

    2017-04-01

    An efficient system for direct delivery of integral membrane proteins is successfully developed using a new biocompatible exosome-based platform. Fusogenic exosomes harboring viral fusogen, vascular stomatitis virus (VSV)-G protein, can fuse with and modify plasma membranes in a process called "membrane editing." This can facilitate the transfer of biologically active membrane proteins into the target cell membranes both in vitro and in vivo. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Sensitivity method for integrated structure/active control law design

    NASA Technical Reports Server (NTRS)

    Gilbert, Michael G.

    1987-01-01

    The development is described of an integrated structure/active control law design methodology for aeroelastic aircraft applications. A short motivating introduction to aeroservoelasticity is given along with the need for integrated structures/controls design algorithms. Three alternative approaches to development of an integrated design method are briefly discussed with regards to complexity, coordination and tradeoff strategies, and the nature of the resulting solutions. This leads to the formulation of the proposed approach which is based on the concepts of sensitivity of optimum solutions and multi-level decompositions. The concept of sensitivity of optimum is explained in more detail and compared with traditional sensitivity concepts of classical control theory. The analytical sensitivity expressions for the solution of the linear, quadratic cost, Gaussian (LQG) control problem are summarized in terms of the linear regulator solution and the Kalman Filter solution. Numerical results for a state space aeroelastic model of the DAST ARW-II vehicle are given, showing the changes in aircraft responses to variations of a structural parameter, in this case first wing bending natural frequency.

  13. Numerical solution of second order ODE directly by two point block backward differentiation formula

    NASA Astrophysics Data System (ADS)

    Zainuddin, Nooraini; Ibrahim, Zarina Bibi; Othman, Khairil Iskandar; Suleiman, Mohamed; Jamaludin, Noraini

    2015-12-01

    Direct Two Point Block Backward Differentiation Formula, (BBDF2) for solving second order ordinary differential equations (ODEs) will be presented throughout this paper. The method is derived by differentiating the interpolating polynomial using three back values. In BBDF2, two approximate solutions are produced simultaneously at each step of integration. The method derived is implemented by using fixed step size and the numerical results that follow demonstrate the advantage of the direct method as compared to the reduction method.

  14. Dynamic Analysis With Stress Mode Animation by the Integrated Force Method

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Coroneos, Rula M.; Hopkins, Dale A.

    1997-01-01

    Dynamic animation of stresses and displacements, which complement each other, can be a useful tool in the analysis and design of structural components. At the present time only displacement-mode animation is available through the popular stiffness formulation. This paper attempts to complete this valuable visualization tool by augmenting the existing art with stress mode animation. The reformulated method of forces, which in the literature is known as the integrated force method (IFM), became the analyzer of choice for the development of stress mode animation because stresses are the primary unknowns of its dynamic analysis. Animation of stresses and displacements, which have been developed successfully through the IFM analyzers, is illustrated in several examples along with a brief introduction to IFM dynamic analysis. The usefulness of animation in design optimization is illustrated considering the spacer structure component of the International Space Station as an example. An overview of the integrated force method analysis code (IFM/ANALYZERS) is provided in the appendix.

  15. Bioinspired one-dimensional materials for directional liquid transport.

    PubMed

    Ju, Jie; Zheng, Yongmei; Jiang, Lei

    2014-08-19

    One-dimensional materials (1D) capable of transporting liquid droplets directionally, such as spider silks and cactus spines, have recently been gathering scientists' attention due to their potential applications in microfluidics, textile dyeing, filtration, and smog removal. This remarkable property comes from the arrangement of the micro- and nanostructures on these organisms' surfaces, which have inspired chemists to develop methods to prepare surfaces with similar directional liquid transport ability. In this Account, we report our recent progress in understanding how this directional transport works, as well our advances in the design and fabrication of bioinspired 1D materials capable of transporting liquid droplets directionally. To begin, we first discuss some basic theories on droplet directional movement. Then, we discuss the mechanism of directional transport of water droplets on natural spider silks. Upon contact with water droplets, the spider silk undergoes what is known as a wet-rebuilt, which forms periodic spindle-knots and joints. We found that the resulting gradient of Laplace pressure and surface free energy between the spindle-knots and joints account for the cooperative driving forces to transport water droplets directionally. Next, we discuss the directional transport of water droplets on desert cactus. The integration of multilevel structures of the cactus and the resulting integration of multiple functions together allow the cactus spine to transport water droplets continuously from tip to base. Based on our studies of natural spider silks and cactus spines, we have prepared a series of artificial spider silks (A-SSs) and artificial cactus spines (A-CSs) with various methods. By changing the surface roughness and chemical compositions of the artificial spider silks' spindle-knots, or by introducing stimulus-responsive molecules, such as thermal-responsive and photoresponsive molecules, onto the spindle-knots, we can reversibly manipulate

  16. Implicit-Explicit Time Integration Methods for Non-hydrostatic Atmospheric Models

    NASA Astrophysics Data System (ADS)

    Gardner, D. J.; Guerra, J. E.; Hamon, F. P.; Reynolds, D. R.; Ullrich, P. A.; Woodward, C. S.

    2016-12-01

    The Accelerated Climate Modeling for Energy (ACME) project is developing a non-hydrostatic atmospheric dynamical core for high-resolution coupled climate simulations on Department of Energy leadership class supercomputers. An important factor in computational efficiency is avoiding the overly restrictive time step size limitations of fully explicit time integration methods due to the stiffest modes present in the model (acoustic waves). In this work we compare the accuracy and performance of different Implicit-Explicit (IMEX) splittings of the non-hydrostatic equations and various Additive Runge-Kutta (ARK) time integration methods. Results utilizing the Tempest non-hydrostatic atmospheric model and the ARKode package show that the choice of IMEX splitting and ARK scheme has a significant impact on the maximum stable time step size as well as solution quality. Horizontally Explicit Vertically Implicit (HEVI) approaches paired with certain ARK methods lead to greatly improved runtimes. With effective preconditioning IMEX splittings that incorporate some implicit horizontal dynamics can be competitive with HEVI results. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-699187

  17. Peritonitis related to percutaneous endoscopic gastrostomy using the direct method for cancer patients.

    PubMed

    Osera, Shozo; Yano, Tomonori; Odagaki, Tomoyuki; Oono, Yasuhiro; Ikematsu, Hiroaki; Ohtsu, Atsushi; Kaneko, Kazuhiro

    2015-10-01

    Percutaneous endoscopic gastrostomy (PEG) using the direct method is generally indicated for cancer patients. However, there are little available data about peritonitis related to this method. The aim of this retrospective analysis was to assess peritonitis related to PEG using the direct method in patients with cancer. We assessed the prevalence of peritonitis and the relationship between peritonitis and patients' backgrounds, as well as the clinical course after peritonitis. Between December 2008 and December 2011, peritonitis was found in 9 (2.1 %) of 421 patients. Of the 9 patients with peritonitis, 4 had received PEG prior to chemoradiotherapy. Emergency surgical drainage was required in 1 patient, and the remaining 8 recovered with conservative treatment. Peritonitis occurred within 8 days of PEG for 8 of the 9 patients and occurred within 2 days of suture removal for 4 of the 9 patients. Peritonitis related to PEG using the direct method was less frequent for cancer patients. Peritonitis tended to occur within a few days after removal of securing suture and in patients with palliative stage.

  18. In vitro sperm characterization and development of a sperm cryopreservation method using directional solidification in the killer whale (Orcinus orca).

    PubMed

    Robeck, T R; Gearhart, S A; Steinman, K J; Katsumata, E; Loureiro, J D; O'Brien, J K

    2011-07-15

    Research was conducted to characterize seminal traits and to develop a sperm cryopreservation method using directional freezing (DF) for the killer whale (Orcinus orca). Experiments evaluated effects of: (i) freezing rate (SLOW, MED, FAST) by diluent (BF5F, Biladyl®, EYC) in 0.5 mL straws; and (ii) freezing method (straw or DF) by glycerol (3, 6, or 9% final concentration, v:v) on in vitro sperm quality. Fresh ejaculates (n = 161) were (mean ± SD) 7.8 ± 7.4 mL at 740 × 10(6) sperm/mL with 92.2 ± 6.3% total motility (TM), 85.4 ± 6.9% progressive motility (PM), 89.6 ± 9.0% viability and 89.8 ± 9.2% acrosome integrity. Samples frozen using straws by the MED or SLOW method were improved (P < 0.05) over FAST across all diluents. At 3 h post thaw (PT), TM, PM, Rapid motility (RM), VAP, VCL, ALH and viability for 3% and 6% glycerol were improved (P < 0.05) over 9% glycerol. Directional freezing samples at 0 h and 3 h PT, at all glycerol concentrations, displayed higher (P < 0.001) TM, PM, RM, VAP, VSL, VCL and viability /intact acrosomes (PI/FITC-PNA) than straw. These data provided the first information on ejaculate characteristics and the development of a semen cryopreservation method using DF in the killer whale. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. An integrated approach for facilities planning by ELECTRE method

    NASA Astrophysics Data System (ADS)

    Elbishari, E. M. Y.; Hazza, M. H. F. Al; Adesta, E. Y. T.; Rahman, Nur Salihah Binti Abdul

    2018-01-01

    Facility planning is concerned with the design, layout, and accommodation of people, machines and activities of a system. Most of the researchers try to investigate the production area layout and the related facilities. However, few of them try to investigate the relationship between the production space and its relationship with service departments. The aim of this research to is to integrate different approaches in order to evaluate, analyse and select the best facilities planning method that able to explain the relationship between the production area and other supporting departments and its effect on human efforts. To achieve the objective of this research two different approaches have been integrated: Apple’s layout procedure as one of the effective tools in planning factories, ELECTRE method as one of the Multi Criteria Decision Making methods (MCDM) to minimize the risk of getting poor facilities planning. Dalia industries have been selected as a case study to implement our integration the factory have been divided two main different area: the whole facility (layout A), and the manufacturing area (layout B). This article will be concerned with the manufacturing area layout (Layout B). After analysing the data gathered, the manufacturing area was divided into 10 activities. There are five factors that the alternative were compared upon which are: Inter department satisfactory level, total distance travelled for workers, total distance travelled for the product, total time travelled for the workers, and total time travelled for the product. Three different layout alternatives have been developed in addition to the original layouts. Apple’s layout procedure was used to study and evaluate the different alternatives layouts, the study and evaluation of the layouts was done by calculating scores for each of the factors. After obtaining the scores from evaluating the layouts, ELECTRE method was used to compare the proposed alternatives with each other and with

  20. Low rank alternating direction method of multipliers reconstruction for MR fingerprinting.

    PubMed

    Assländer, Jakob; Cloos, Martijn A; Knoll, Florian; Sodickson, Daniel K; Hennig, Jürgen; Lattanzi, Riccardo

    2018-01-01

    The proposed reconstruction framework addresses the reconstruction accuracy, noise propagation and computation time for magnetic resonance fingerprinting. Based on a singular value decomposition of the signal evolution, magnetic resonance fingerprinting is formulated as a low rank (LR) inverse problem in which one image is reconstructed for each singular value under consideration. This LR approximation of the signal evolution reduces the computational burden by reducing the number of Fourier transformations. Also, the LR approximation improves the conditioning of the problem, which is further improved by extending the LR inverse problem to an augmented Lagrangian that is solved by the alternating direction method of multipliers. The root mean square error and the noise propagation are analyzed in simulations. For verification, in vivo examples are provided. The proposed LR alternating direction method of multipliers approach shows a reduced root mean square error compared to the original fingerprinting reconstruction, to a LR approximation alone and to an alternating direction method of multipliers approach without a LR approximation. Incorporating sensitivity encoding allows for further artifact reduction. The proposed reconstruction provides robust convergence, reduced computational burden and improved image quality compared to other magnetic resonance fingerprinting reconstruction approaches evaluated in this study. Magn Reson Med 79:83-96, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. A novel technique for optimal integration of active steering and differential braking with estimation to improve vehicle directional stability.

    PubMed

    Mirzaeinejad, Hossein; Mirzaei, Mehdi; Rafatnia, Sadra

    2018-06-11

    This study deals with the enhancement of directional stability of vehicle which turns with high speeds on various road conditions using integrated active steering and differential braking systems. In this respect, the minimum usage of intentional asymmetric braking force to compensate the drawbacks of active steering control with small reduction of vehicle longitudinal speed is desired. To this aim, a new optimal multivariable controller is analytically developed for integrated steering and braking systems based on the prediction of vehicle nonlinear responses. A fuzzy programming extracted from the nonlinear phase plane analysis is also used for managing the two control inputs in various driving conditions. With the proposed fuzzy programming, the weight factors of the control inputs are automatically tuned and softly changed. In order to simulate a real-world control system, some required information about the system states and parameters which cannot be directly measured, are estimated using the Unscented Kalman Filter (UKF). Finally, simulations studies are carried out using a validated vehicle model to show the effectiveness of the proposed integrated control system in the presence of model uncertainties and estimation errors. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  2. A study of methods to predict and measure the transmission of sound through the walls of light aircraft. Integration of certain singular boundary element integrals for applications in linear acoustics

    NASA Technical Reports Server (NTRS)

    Zimmerle, D.; Bernhard, R. J.

    1985-01-01

    An alternative method for performing singular boundary element integrals for applications in linear acoustics is discussed. The method separates the integral of the characteristic solution into a singular and nonsingular part. The singular portion is integrated with a combination of analytic and numerical techniques while the nonsingular portion is integrated with standard Gaussian quadrature. The method may be generalized to many types of subparametric elements. The integrals over elements containing the root node are considered, and the characteristic solution for linear acoustic problems are examined. The method may be generalized to most characteristic solutions.

  3. [An integrated segmentation method for 3D ultrasound carotid artery].

    PubMed

    Yang, Xin; Wu, Huihui; Liu, Yang; Xu, Hongwei; Liang, Huageng; Cai, Wenjuan; Fang, Mengjie; Wang, Yujie

    2013-07-01

    An integrated segmentation method for 3D ultrasound carotid artery was proposed. 3D ultrasound image was sliced into transverse, coronal and sagittal 2D images on the carotid bifurcation point. Then, the three images were processed respectively, and the carotid artery contours and thickness were obtained finally. This paper tries to overcome the disadvantages of current computer aided diagnosis method, such as high computational complexity, easily introduced subjective errors et al. The proposed method could get the carotid artery overall information rapidly, accurately and completely. It could be transplanted into clinical usage for atherosclerosis diagnosis and prevention.

  4. Directional microwave applicator and methods

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W. (Inventor); Lin, Greg Y. (Inventor); Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor)

    2008-01-01

    A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.

  5. Bayesian functional integral method for inferring continuous data from discrete measurements.

    PubMed

    Heuett, William J; Miller, Bernard V; Racette, Susan B; Holloszy, John O; Chow, Carson C; Periwal, Vipul

    2012-02-08

    Inference of the insulin secretion rate (ISR) from C-peptide measurements as a quantification of pancreatic β-cell function is clinically important in diseases related to reduced insulin sensitivity and insulin action. ISR derived from C-peptide concentration is an example of nonparametric Bayesian model selection where a proposed ISR time-course is considered to be a "model". An inferred value of inaccessible continuous variables from discrete observable data is often problematic in biology and medicine, because it is a priori unclear how robust the inference is to the deletion of data points, and a closely related question, how much smoothness or continuity the data actually support. Predictions weighted by the posterior distribution can be cast as functional integrals as used in statistical field theory. Functional integrals are generally difficult to evaluate, especially for nonanalytic constraints such as positivity of the estimated parameters. We propose a computationally tractable method that uses the exact solution of an associated likelihood function as a prior probability distribution for a Markov-chain Monte Carlo evaluation of the posterior for the full model. As a concrete application of our method, we calculate the ISR from actual clinical C-peptide measurements in human subjects with varying degrees of insulin sensitivity. Our method demonstrates the feasibility of functional integral Bayesian model selection as a practical method for such data-driven inference, allowing the data to determine the smoothing timescale and the width of the prior probability distribution on the space of models. In particular, our model comparison method determines the discrete time-step for interpolation of the unobservable continuous variable that is supported by the data. Attempts to go to finer discrete time-steps lead to less likely models. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  6. A finite element: Boundary integral method for electromagnetic scattering. Ph.D. Thesis Technical Report, Feb. - Sep. 1992

    NASA Technical Reports Server (NTRS)

    Collins, J. D.; Volakis, John L.

    1992-01-01

    A method that combines the finite element and boundary integral techniques for the numerical solution of electromagnetic scattering problems is presented. The finite element method is well known for requiring a low order storage and for its capability to model inhomogeneous structures. Of particular emphasis in this work is the reduction of the storage requirement by terminating the finite element mesh on a boundary in a fashion which renders the boundary integrals in convolutional form. The fast Fourier transform is then used to evaluate these integrals in a conjugate gradient solver, without a need to generate the actual matrix. This method has a marked advantage over traditional integral equation approaches with respect to the storage requirement of highly inhomogeneous structures. Rectangular, circular, and ogival mesh termination boundaries are examined for two-dimensional scattering. In the case of axially symmetric structures, the boundary integral matrix storage is reduced by exploiting matrix symmetries and solving the resulting system via the conjugate gradient method. In each case several results are presented for various scatterers aimed at validating the method and providing an assessment of its capabilities. Important in methods incorporating boundary integral equations is the issue of internal resonance. A method is implemented for their removal, and is shown to be effective in the two-dimensional and three-dimensional applications.

  7. Conservation properties of numerical integration methods for systems of ordinary differential equations

    NASA Technical Reports Server (NTRS)

    Rosenbaum, J. S.

    1976-01-01

    If a system of ordinary differential equations represents a property conserving system that can be expressed linearly (e.g., conservation of mass), it is then desirable that the numerical integration method used conserve the same quantity. It is shown that both linear multistep methods and Runge-Kutta methods are 'conservative' and that Newton-type methods used to solve the implicit equations preserve the inherent conservation of the numerical method. It is further shown that a method used by several authors is not conservative.

  8. Frontal transcranial direct current stimulation (tDCS) abolishes list-method directed forgetting.

    PubMed

    Silas, Jonathan; Brandt, Karen R

    2016-03-11

    It is a point of controversy as to whether directed forgetting effects are a result of active inhibition or a change of context initiated by the instruction to forget. In this study we test the causal role of active inhibition in directed forgetting. By applying cathodal transcranial direct current stimulation (tDCS) over the right prefrontal cortex we suppressed cortical activity commonly associated with inhibitory control. Participants who underwent real brain stimulation before completing the directed forgetting paradigm showed no directed forgetting effects. Conversely, those who underwent sham brain stimulation demonstrated classical directed forgetting effects. We argue that these findings suggest that inhibition is the primary mechanism that results in directed forgetting costs and benefits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Method for the numerical integration of equations of perturbed satellite motion in problems of space geodesy

    NASA Astrophysics Data System (ADS)

    Plakhov, Iu. V.; Mytsenko, A. V.; Shel'Pov, V. A.

    A numerical integration method is developed that is more accurate than Everhart's (1974) implicit single-sequence approach for integrating orbits. This method can be used to solve problems of space geodesy based on the use of highly precise laser observations.

  10. Direct demodulation method for heavy atom position determination in protein crystallography

    NASA Astrophysics Data System (ADS)

    Zhou, Liang; Liu, Zhong-Chuan; Liu, Peng; Dong, Yu-Hui

    2013-01-01

    The first step of phasing in any de novo protein structure determination using isomorphous replacement (IR) or anomalous scattering (AD) experiments is to find heavy atom positions. Traditionally, heavy atom positions can be solved by inspecting the difference Patterson maps. Due to the weak signals in isomorphous or anomalous differences and the noisy background in the Patterson map, the search for heavy atoms may become difficult. Here, the direct demodulation (DD) method is applied to the difference Patterson maps to reduce the noisy backgrounds and sharpen the signal peaks. The real space Patterson search by using these optimized maps can locate the heavy atom positions more accurately. It is anticipated that the direct demodulation method can assist in heavy atom position determination and facilitate the de novo structure determination of proteins.

  11. Comparison of direct and indirect methods of estimating health state utilities for resource allocation: review and empirical analysis.

    PubMed

    Arnold, David; Girling, Alan; Stevens, Andrew; Lilford, Richard

    2009-07-22

    Utilities (values representing preferences) for healthcare priority setting are typically obtained indirectly by asking patients to fill in a quality of life questionnaire and then converting the results to a utility using population values. We compared such utilities with those obtained directly from patients or the public. Review of studies providing both a direct and indirect utility estimate. Papers reporting comparisons of utilities obtained directly (standard gamble or time tradeoff) or indirectly (European quality of life 5D [EQ-5D], short form 6D [SF-6D], or health utilities index [HUI]) from the same patient. PubMed and Tufts database of utilities. Sign test for paired comparisons between direct and indirect utilities; least squares regression to describe average relations between the different methods. Mean utility scores (or median if means unavailable) for each method, and differences in mean (median) scores between direct and indirect methods. We found 32 studies yielding 83 instances where direct and indirect methods could be compared for health states experienced by adults. The direct methods used were standard gamble in 57 cases and time trade off in 60(34 used both); the indirect methods were EQ-5D (67 cases), SF-6D (13), HUI-2 (5), and HUI-3 (37). Mean utility values were 0.81 (standard gamble) and 0.77 (time tradeoff) for the direct methods; for the indirect methods: 0.59(EQ-5D), 0.63 (SF-6D), 0.75 (HUI-2) and 0.68 (HUI-3). Direct methods of estimating utilities tend to result in higher health ratings than the more widely used indirect methods, and the difference can be substantial.Use of indirect methods could have important implications for decisions about resource allocation: for example, non-lifesaving treatments are relatively more favoured in comparison with lifesaving interventions than when using direct methods.

  12. Apparatus and methods for packaging integrated circuit chips with antenna modules providing closed electromagnetic environment for integrated antennas

    NASA Technical Reports Server (NTRS)

    Gaucher, Brian P. (Inventor); Grzyb, Janusz (Inventor); Liu, Duixian (Inventor); Pfeiffer, Ullrich R. (Inventor)

    2008-01-01

    Apparatus and methods are provided for packaging IC chips together with integrated antenna modules designed to provide a closed EM (electromagnetic) environment for antenna radiators, thereby allowing antennas to be designed independent from the packaging technology.

  13. An edge-directed interpolation method for fetal spine MR images.

    PubMed

    Yu, Shaode; Zhang, Rui; Wu, Shibin; Hu, Jiani; Xie, Yaoqin

    2013-10-10

    Fetal spinal magnetic resonance imaging (MRI) is a prenatal routine for proper assessment of fetus development, especially when suspected spinal malformations occur while ultrasound fails to provide details. Limited by hardware, fetal spine MR images suffer from its low resolution.High-resolution MR images can directly enhance readability and improve diagnosis accuracy. Image interpolation for higher resolution is required in clinical situations, while many methods fail to preserve edge structures. Edge carries heavy structural messages of objects in visual scenes for doctors to detect suspicions, classify malformations and make correct diagnosis. Effective interpolation with well-preserved edge structures is still challenging. In this paper, we propose an edge-directed interpolation (EDI) method and apply it on a group of fetal spine MR images to evaluate its feasibility and performance. This method takes edge messages from Canny edge detector to guide further pixel modification. First, low-resolution (LR) images of fetal spine are interpolated into high-resolution (HR) images with targeted factor by bi-linear method. Then edge information from LR and HR images is put into a twofold strategy to sharpen or soften edge structures. Finally a HR image with well-preserved edge structures is generated. The HR images obtained from proposed method are validated and compared with that from other four EDI methods. Performances are evaluated from six metrics, and subjective analysis of visual quality is based on regions of interest (ROI). All these five EDI methods are able to generate HR images with enriched details. From quantitative analysis of six metrics, the proposed method outperforms the other four from signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), structure similarity index (SSIM), feature similarity index (FSIM) and mutual information (MI) with seconds-level time consumptions (TC). Visual analysis of ROI shows that the proposed method maintains

  14. A modified precise integration method for transient dynamic analysis in structural systems with multiple damping models

    NASA Astrophysics Data System (ADS)

    Ding, Zhe; Li, Li; Hu, Yujin

    2018-01-01

    Sophisticated engineering systems are usually assembled by subcomponents with significantly different levels of energy dissipation. Therefore, these damping systems often contain multiple damping models and lead to great difficulties in analyzing. This paper aims at developing a time integration method for structural systems with multiple damping models. The dynamical system is first represented by a generally damped model. Based on this, a new extended state-space method for the damped system is derived. A modified precise integration method with Gauss-Legendre quadrature is then proposed. The numerical stability and accuracy of the proposed integration method are discussed in detail. It is verified that the method is conditionally stable and has inherent algorithmic damping, period error and amplitude decay. Numerical examples are provided to assess the performance of the proposed method compared with other methods. It is demonstrated that the method is more accurate than other methods with rather good efficiency and the stable condition is easy to be satisfied in practice.

  15. Physical and Economic Integration of Carbon Capture Methods with Sequestration Sinks

    NASA Astrophysics Data System (ADS)

    Murrell, G. R.; Thyne, G. D.

    2007-12-01

    Currently there are several different carbon capture technologies either available or in active development for coal- fired power plants. Each approach has different advantages, limitations and costs that must be integrated with the method of sequestration and the physiochemical properties of carbon dioxide to evaluate which approach is most cost effective. For large volume point sources such as coal-fired power stations, the only viable sequestration sinks are either oceanic or geological in nature. However, the carbon processes and systems under consideration produce carbon dioxide at a variety of pressure and temperature conditions that must be made compatible with the sinks. Integration of all these factors provides a basis for meaningful economic comparisons between the alternatives. The high degree of compatibility between carbon dioxide produced by integrated gasification combined cycle technology and geological sequestration conditions makes it apparent that this coupling currently holds the advantage. Using a basis that includes complete source-to-sink sequestration costs, the relative cost benefit of pre-combustion IGCC compared to other post-combustion methods is on the order of 30%. Additional economic benefits arising from enhanced oil recovery revenues and potential sequestration credits further improve this coupling.

  16. The Directed Case Method.

    ERIC Educational Resources Information Center

    Cliff, William H.; Curtin, Leslie Nesbitt

    2000-01-01

    Provides an example of a directed case on human anatomy and physiology. Uses brief real life newspaper articles and clinical descriptions of medical reference texts to describe an actual, fictitious, or composite event. Includes interrelated human anatomy and physiology topics in the scenario. (YDS)

  17. Photonic generation of ultra-wideband signals by direct current modulation on SOA section of an SOA-integrated SGDBR laser.

    PubMed

    Lv, Hui; Yu, Yonglin; Shu, Tan; Huang, Dexiu; Jiang, Shan; Barry, Liam P

    2010-03-29

    Photonic ultra-wideband (UWB) pulses are generated by direct current modulation of a semiconductor optical amplifier (SOA) section of an SOA-integrated sampled grating distributed Bragg reflector (SGDBR) laser. Modulation responses of the SOA section of the laser are first simulated with a microwave equivalent circuit model. Simulated results show a resonance behavior indicating the possibility to generate UWB signals with complex shapes in the time domain. The UWB pulse generation is then experimentally demonstrated for different selected wavelength channels with an SOA-integrated SGDBR laser.

  18. The evolution of phenotypic integration: How directional selection reshapes covariation in mice.

    PubMed

    Penna, Anna; Melo, Diogo; Bernardi, Sandra; Oyarzabal, Maria Inés; Marroig, Gabriel

    2017-10-01

    Variation is the basis for evolution, and understanding how variation can evolve is a central question in biology. In complex phenotypes, covariation plays an even more important role, as genetic associations between traits can bias and alter evolutionary change. Covariation can be shaped by complex interactions between loci, and this genetic architecture can also change during evolution. In this article, we analyzed mouse lines experimentally selected for changes in size to address the question of how multivariate covariation changes under directional selection, as well as to identify the consequences of these changes to evolution. Selected lines showed a clear restructuring of covariation in their cranium and, instead of depleting their size variation, these lines increased their magnitude of integration and the proportion of variation associated with the direction of selection. This result is compatible with recent theoretical works on the evolution of covariation that take the complexities of genetic architecture into account. This result also contradicts the traditional view of the effects of selection on available covariation and suggests a much more complex view of how populations respond to selection. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  19. Vision-Aided RAIM: A New Method for GPS Integrity Monitoring in Approach and Landing Phase

    PubMed Central

    Fu, Li; Zhang, Jun; Li, Rui; Cao, Xianbin; Wang, Jinling

    2015-01-01

    In the 1980s, Global Positioning System (GPS) receiver autonomous integrity monitoring (RAIM) was proposed to provide the integrity of a navigation system by checking the consistency of GPS measurements. However, during the approach and landing phase of a flight path, where there is often low GPS visibility conditions, the performance of the existing RAIM method may not meet the stringent aviation requirements for availability and integrity due to insufficient observations. To solve this problem, a new RAIM method, named vision-aided RAIM (VA-RAIM), is proposed for GPS integrity monitoring in the approach and landing phase. By introducing landmarks as pseudo-satellites, the VA-RAIM enriches the navigation observations to improve the performance of RAIM. In the method, a computer vision system photographs and matches these landmarks to obtain additional measurements for navigation. Nevertheless, the challenging issue is that such additional measurements may suffer from vision errors. To ensure the reliability of the vision measurements, a GPS-based calibration algorithm is presented to reduce the time-invariant part of the vision errors. Then, the calibrated vision measurements are integrated with the GPS observations for integrity monitoring. Simulation results show that the VA-RAIM outperforms the conventional RAIM with a higher level of availability and fault detection rate. PMID:26378533

  20. Vision-Aided RAIM: A New Method for GPS Integrity Monitoring in Approach and Landing Phase.

    PubMed

    Fu, Li; Zhang, Jun; Li, Rui; Cao, Xianbin; Wang, Jinling

    2015-09-10

    In the 1980s, Global Positioning System (GPS) receiver autonomous integrity monitoring (RAIM) was proposed to provide the integrity of a navigation system by checking the consistency of GPS measurements. However, during the approach and landing phase of a flight path, where there is often low GPS visibility conditions, the performance of the existing RAIM method may not meet the stringent aviation requirements for availability and integrity due to insufficient observations. To solve this problem, a new RAIM method, named vision-aided RAIM (VA-RAIM), is proposed for GPS integrity monitoring in the approach and landing phase. By introducing landmarks as pseudo-satellites, the VA-RAIM enriches the navigation observations to improve the performance of RAIM. In the method, a computer vision system photographs and matches these landmarks to obtain additional measurements for navigation. Nevertheless, the challenging issue is that such additional measurements may suffer from vision errors. To ensure the reliability of the vision measurements, a GPS-based calibration algorithm is presented to reduce the time-invariant part of the vision errors. Then, the calibrated vision measurements are integrated with the GPS observations for integrity monitoring. Simulation results show that the VA-RAIM outperforms the conventional RAIM with a higher level of availability and fault detection rate.

  1. A method for estimating direct normal solar irradiation from satellite data for a tropical environment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Janjai, Serm

    In order to investigate a potential use of concentrating solar power technologies and select an optimum site for these technologies, it is necessary to obtain information on the geographical distribution of direct normal solar irradiation over an area of interest. In this work, we have developed a method for estimating direct normal irradiation from satellite data for a tropical environment. The method starts with the estimation of global irradiation on a horizontal surface from MTSAT-1R satellite data and other ground-based ancillary data. Then a satellite-based diffuse fraction model was developed and used to estimate the diffuse component of the satellite-derivedmore » global irradiation. Based on this estimated global and diffuse irradiation and the solar radiation incident angle, the direct normal irradiation was finally calculated. To evaluate its performance, the method was used to estimate the monthly average hourly direct normal irradiation at seven pyrheliometer stations in Thailand. It was found that values of monthly average hourly direct normal irradiation from the measurements and those estimated from the proposed method are in reasonable agreement, with a root mean square difference of 16% and a mean bias of -1.6%, with respect to mean measured values. After the validation, this method was used to estimate the monthly average hourly direct normal irradiation over Thailand by using MTSAT-1R satellite data for the period from June 2005 to December 2008. Results from the calculation were displayed as hourly and yearly irradiation maps. These maps reveal that the direct normal irradiation in Thailand was strongly affected by the tropical monsoons and local topography of the country. (author)« less

  2. An integrated direct loop-mediated isothermal amplification microdevice incorporated with an immunochromatographic strip for bacteria detection in human whole blood and milk without a sample preparation step.

    PubMed

    Lee, Dohwan; Kim, Yong Tae; Lee, Jee Won; Kim, Do Hyun; Seo, Tae Seok

    2016-05-15

    We have developed an integrated direct loop-mediated isothermal amplification (Direct LAMP) microdevice incorporated with an immunochromatographic strip (ICS) to identify bacteria contaminated in real samples. The Direct LAMP is a novel isothermal DNA amplification technique which does not require thermal cycling steps as well as any sample preparation steps such as cell lysis and DNA extraction for amplifying specific target genes. In addition, the resultant amplicons were colorimetrically detected on the ICS, thereby enabling the entire genetic analysis process to be simplified. The two functional units (Direct LAMP and ICS) were integrated on a single device without use of the tedious and complicated microvalve and tubing systems. The utilization of a slidable plate allows us to manipulate the fluidic control in the microchannels manually and the sequential operation of the Direct LAMP and ICS detection could be performed by switching the slidable plate to each functional unit. Thus, the combination of the direct isothermal amplification without any sample preparation and thermal cycling steps, the ICS based amplicon detection by naked eyes, and the slidable plate to eliminate the microvalves in the integrated microdevice would be an ideal platform for point-of-care DNA diaganotics. On the integrated Direct LAMP-ICS microdevice, we could analyze Staphylococcus aureus (S. aureus) and Escherichia coli O157:H7 (E. coli O157:H7) contaminated in human whole blood or milk at a single-cell level within 1h. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. A Gas Dynamics Method Based on The Spectral Deferred Corrections (SDC) Time Integration Technique and The Piecewise Parabolic Method (PPM)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samet Y. Kadioglu

    2011-12-01

    We present a computational gas dynamics method based on the Spectral Deferred Corrections (SDC) time integration technique and the Piecewise Parabolic Method (PPM) finite volume method. The PPM framework is used to define edge averaged quantities which are then used to evaluate numerical flux functions. The SDC technique is used to integrate solution in time. This kind of approach was first taken by Anita et al in [17]. However, [17] is problematic when it is implemented to certain shock problems. Here we propose significant improvements to [17]. The method is fourth order (both in space and time) for smooth flows,more » and provides highly resolved discontinuous solutions. We tested the method by solving variety of problems. Results indicate that the fourth order of accuracy in both space and time has been achieved when the flow is smooth. Results also demonstrate the shock capturing ability of the method.« less

  4. Directed electromagnetic wave propagation in 1D metamaterial: Projecting operators method

    NASA Astrophysics Data System (ADS)

    Ampilogov, Dmitrii; Leble, Sergey

    2016-07-01

    We consider a boundary problem for 1D electrodynamics modeling of a pulse propagation in a metamaterial medium. We build and apply projecting operators to a Maxwell system in time domain that allows to split the linear propagation problem to directed waves for a material relations with general dispersion. Matrix elements of the projectors act as convolution integral operators. For a weak nonlinearity we generalize the linear results still for arbitrary dispersion and derive the system of interacting right/left waves with combined (hybrid) amplitudes. The result is specified for the popular metamaterial model with Drude formula for both permittivity and permeability coefficients. We also discuss and investigate stationary solutions of the system related to some boundary regimes.

  5. On the inversion of geodetic integrals defined over the sphere using 1-D FFT

    NASA Astrophysics Data System (ADS)

    García, R. V.; Alejo, C. A.

    2005-08-01

    An iterative method is presented which performs inversion of integrals defined over the sphere. The method is based on one-dimensional fast Fourier transform (1-D FFT) inversion and is implemented with the projected Landweber technique, which is used to solve constrained least-squares problems reducing the associated 1-D cyclic-convolution error. The results obtained are as precise as the direct matrix inversion approach, but with better computational efficiency. A case study uses the inversion of Hotine’s integral to obtain gravity disturbances from geoid undulations. Numerical convergence is also analyzed and comparisons with respect to the direct matrix inversion method using conjugate gradient (CG) iteration are presented. Like the CG method, the number of iterations needed to get the optimum (i.e., small) error decreases as the measurement noise increases. Nevertheless, for discrete data given over a whole parallel band, the method can be applied directly without implementing the projected Landweber method, since no cyclic convolution error exists.

  6. Direct design of aspherical lenses for extended non-Lambertian sources in two-dimensional geometry

    PubMed Central

    Wu, Rengmao; Hua, Hong; Benítez, Pablo; Miñano, Juan C.

    2016-01-01

    Illumination design for extended sources is very important for practical applications. The existing direct methods that are all developed for extended Lambertian sources are not applicable to extended non-Lambertian sources whose luminance is a function of position and direction. What we present in this Letter is to our knowledge the first direct method for extended non-Lambertian sources. In this method, the edge rays and the interior rays are both used, and the output intensity at a given direction is calculated to be the integral of the luminance function of all the outgoing rays at this direction. No cumbersome iterative illuminance compensation is needed. Two examples are presented to demonstrate the elegance of this method in prescribed intensity design for extended non-Lambertian sources in two-dimensional geometry. PMID:26125361

  7. Genetic Testing Integration Panels (GTIPs): A novel approach for considering integration of direct-to-consumer and other new genetic tests into patient care

    PubMed Central

    Uhlmann, Wendy R.; Sharp, Richard R.

    2014-01-01

    There has been a dramatic increase in the number of genetic tests available but few tests have practice guidelines. In addition, many tests have become available outside of genetics clinics through direct-to-consumer (DTC) companies and several offer tests not considered standard of care. To address several practical challenges associated with the rapid introduction of clinical and DTC genetic tests, we propose that genetic counselors and geneticists organize expert panels in their institutions to discuss the integration of new tests into patient care. We propose the establishment of Genetic Testing Integration Panels (GTIPs) to bring together local experts in medical genetics, genetic counseling, bioethics and law, health communication and clinical laboratory genetics. We describe key features of this approach and consider some of the potential advantages and limitations of using a GTIP to address the many clinical challenges raised by rapidly emerging clinical and DTC genetic tests. PMID:22246561

  8. Three methods for integration of environmental risk into the benefit-risk assessment of veterinary medicinal products.

    PubMed

    Chapman, Jennifer L; Porsch, Lucas; Vidaurre, Rodrigo; Backhaus, Thomas; Sinclair, Chris; Jones, Glyn; Boxall, Alistair B A

    2017-12-15

    Veterinary medicinal products (VMPs) require, as part of the European Union (EU) authorization process, consideration of both risks and benefits. Uses of VMPs have multiple risks (e.g., risks to the animal being treated, to the person administering the VMP) including risks to the environment. Environmental risks are not directly comparable to therapeutic benefits; there is no standardized approach to compare both environmental risks and therapeutic benefits. We have developed three methods for communicating and comparing therapeutic benefits and environmental risks for the benefit-risk assessment that supports the EU authorization process. Two of these methods support independent product evaluation (i.e., a summative classification and a visual scoring matrix classification); the other supports a comparative evaluation between alternative products (i.e., a comparative classification). The methods and the challenges to implementing a benefit-risk assessment including environmental risk are presented herein; how these concepts would work in current policy is discussed. Adaptability to scientific and policy development is considered. This work is an initial step in the development of a standardized methodology for integrated decision-making for VMPs. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The Mass-Metallicity Relation with the Direct Method on Stacked Spectra of SDSS Galaxies

    NASA Astrophysics Data System (ADS)

    Andrews, Brett H.; Martini, Paul

    2013-03-01

    The relation between galaxy stellar mass and gas-phase metallicity is a sensitive diagnostic of the main processes that drive galaxy evolution, namely cosmological gas inflow, metal production in stars, and gas outflow via galactic winds. We employed the direct method to measure the metallicities of ~200,000 star-forming galaxies from the Sloan Digital Sky Survey that were stacked in bins of (1) stellar mass and (2) both stellar mass and star formation rate (SFR) to significantly enhance the signal-to-noise ratio of the weak [O III] λ4363 and [O II] λλ7320, 7330 auroral lines required to apply the direct method. These metallicity measurements span three decades in stellar mass from log(M sstarf/M ⊙) = 7.4-10.5, which allows the direct method mass-metallicity relation to simultaneously capture the high-mass turnover and extend a full decade lower in mass than previous studies that employed more uncertain strong line methods. The direct method mass-metallicity relation rises steeply at low mass (O/H vprop M sstarf 1/2) until it turns over at log(M sstarf/M ⊙) = 8.9 and asymptotes to 12 + log(O/H) = 8.8 at high mass. The direct method mass-metallicity relation has a steeper slope, a lower turnover mass, and a factor of two to three greater dependence on SFR than strong line mass-metallicity relations. Furthermore, the SFR-dependence appears monotonic with stellar mass, unlike strong line mass-metallicity relations. We also measure the N/O abundance ratio, an important tracer of star formation history, and find the clear signature of primary and secondary nitrogen enrichment. N/O correlates tightly with oxygen abundance, and even more so with stellar mass.

  10. The Detection Method of Fire Abnormal Based on Directional Drilling in Complex Conditions of Mine

    NASA Astrophysics Data System (ADS)

    Huijun, Duan; Shijun, Hao; Jie, Feng

    2018-06-01

    In the light of more and more urgent hidden fire abnormal detection problem in complex conditions of mine, a method which is used directional drilling technology is put forward. The method can avoid the obstacles in mine, and complete the fire abnormal detection. This paper based on analyzing the trajectory control of directional drilling, measurement while drilling and the characteristic of open branch process, the project of the directional drilling is formulated combination with a complex condition mine, and the detection of fire abnormal is implemented. This method can provide technical support for fire prevention, which also can provide a new way for fire anomaly detection in the similar mine.

  11. Self-Directed Learning: Pedagogical Influences on Graduate Student Perspectives

    ERIC Educational Resources Information Center

    Kranzow, Jeannine; Bledsoe, T. Scott

    2017-01-01

    Self-directed learning (SDL), while essential to graduate student success and continued professional development beyond the degree, is rarely addressed intentionally in the college curriculum. In this mixed-method study with 91 participants from two counseling-related degree programs, researchers examined the impact of integrating a unit focused…

  12. An Integrated Method for Airfoil Optimization

    NASA Astrophysics Data System (ADS)

    Okrent, Joshua B.

    Design exploration and optimization is a large part of the initial engineering and design process. To evaluate the aerodynamic performance of a design, viscous Navier-Stokes solvers can be used. However this method can prove to be overwhelmingly time consuming when performing an initial design sweep. Therefore, another evaluation method is needed to provide accurate results at a faster pace. To accomplish this goal, a coupled viscous-inviscid method is used. This thesis proposes an integrated method for analyzing, evaluating, and optimizing an airfoil using a coupled viscous-inviscid solver along with a genetic algorithm to find the optimal candidate. The method proposed is different from prior optimization efforts in that it greatly broadens the design space, while allowing the optimization to search for the best candidate that will meet multiple objectives over a characteristic mission profile rather than over a single condition and single optimization parameter. The increased design space is due to the use of multiple parametric airfoil families, namely the NACA 4 series, CST family, and the PARSEC family. Almost all possible airfoil shapes can be created with these three families allowing for all possible configurations to be included. This inclusion of multiple airfoil families addresses a possible criticism of prior optimization attempts since by only focusing on one airfoil family, they were inherently limiting the number of possible airfoil configurations. By using multiple parametric airfoils, it can be assumed that all reasonable airfoil configurations are included in the analysis and optimization and that a global and not local maximum is found. Additionally, the method used is amenable to customization to suit any specific needs as well as including the effects of other physical phenomena or design criteria and/or constraints. This thesis found that an airfoil configuration that met multiple objectives could be found for a given set of nominal

  13. Effective Alternating Direction Optimization Methods for Sparsity-Constrained Blind Image Deblurring.

    PubMed

    Xiong, Naixue; Liu, Ryan Wen; Liang, Maohan; Wu, Di; Liu, Zhao; Wu, Huisi

    2017-01-18

    Single-image blind deblurring for imaging sensors in the Internet of Things (IoT) is a challenging ill-conditioned inverse problem, which requires regularization techniques to stabilize the image restoration process. The purpose is to recover the underlying blur kernel and latent sharp image from only one blurred image. Under many degraded imaging conditions, the blur kernel could be considered not only spatially sparse, but also piecewise smooth with the support of a continuous curve. By taking advantage of the hybrid sparse properties of the blur kernel, a hybrid regularization method is proposed in this paper to robustly and accurately estimate the blur kernel. The effectiveness of the proposed blur kernel estimation method is enhanced by incorporating both the L 1 -norm of kernel intensity and the squared L 2 -norm of the intensity derivative. Once the accurate estimation of the blur kernel is obtained, the original blind deblurring can be simplified to the direct deconvolution of blurred images. To guarantee robust non-blind deconvolution, a variational image restoration model is presented based on the L 1 -norm data-fidelity term and the total generalized variation (TGV) regularizer of second-order. All non-smooth optimization problems related to blur kernel estimation and non-blind deconvolution are effectively handled by using the alternating direction method of multipliers (ADMM)-based numerical methods. Comprehensive experiments on both synthetic and realistic datasets have been implemented to compare the proposed method with several state-of-the-art methods. The experimental comparisons have illustrated the satisfactory imaging performance of the proposed method in terms of quantitative and qualitative evaluations.

  14. The theory and method of variable frequency directional seismic wave under the complex geologic conditions

    NASA Astrophysics Data System (ADS)

    Jiang, T.; Yue, Y.

    2017-12-01

    It is well known that the mono-frequency directional seismic wave technology can concentrate seismic waves into a beam. However, little work on the method and effect of variable frequency directional seismic wave under complex geological conditions have been done .We studied the variable frequency directional wave theory in several aspects. Firstly, we studied the relation between directional parameters and the direction of the main beam. Secondly, we analyzed the parameters that affect the beam width of main beam significantly, such as spacing of vibrator, wavelet dominant frequency, and number of vibrator. In addition, we will study different characteristics of variable frequency directional seismic wave in typical velocity models. In order to examine the propagation characteristics of directional seismic wave, we designed appropriate parameters according to the character of direction parameters, which is capable to enhance the energy of the main beam direction. Further study on directional seismic wave was discussed in the viewpoint of power spectral. The results indicate that the energy intensity of main beam direction increased 2 to 6 times for a multi-ore body velocity model. It showed us that the variable frequency directional seismic technology provided an effective way to strengthen the target signals under complex geological conditions. For concave interface model, we introduced complicated directional seismic technology which supports multiple main beams to obtain high quality data. Finally, we applied the 9-element variable frequency directional seismic wave technology to process the raw data acquired in a oil-shale exploration area. The results show that the depth of exploration increased 4 times with directional seismic wave method. Based on the above analysis, we draw the conclusion that the variable frequency directional seismic wave technology can improve the target signals of different geologic conditions and increase exploration depth with little

  15. The uniform asymptotic swallowtail approximation - Practical methods for oscillating integrals with four coalescing saddle points

    NASA Technical Reports Server (NTRS)

    Connor, J. N. L.; Curtis, P. R.; Farrelly, D.

    1984-01-01

    Methods that can be used in the numerical implementation of the uniform swallowtail approximation are described. An explicit expression for that approximation is presented to the lowest order, showing that there are three problems which must be overcome in practice before the approximation can be applied to any given problem. It is shown that a recently developed quadrature method can be used for the accurate numerical evaluation of the swallowtail canonical integral and its partial derivatives. Isometric plots of these are presented to illustrate some of their properties. The problem of obtaining the arguments of the swallowtail integral from an analytical function of its argument is considered, describing two methods of solving this problem. The asymptotic evaluation of the butterfly canonical integral is addressed.

  16. A combined direct/inverse three-dimensional transonic wing design method for vector computers

    NASA Technical Reports Server (NTRS)

    Weed, R. A.; Carlson, L. A.; Anderson, W. K.

    1984-01-01

    A three-dimensional transonic-wing design algorithm for vector computers is developed, and the results of sample computations are presented graphically. The method incorporates the direct/inverse scheme of Carlson (1975), a Cartesian grid system with boundary conditions applied at a mean plane, and a potential-flow solver based on the conservative form of the full potential equation and using the ZEBRA II vectorizable solution algorithm of South et al. (1980). The accuracy and consistency of the method with regard to direct and inverse analysis and trailing-edge closure are verified in the test computations.

  17. cuSwift --- a suite of numerical integration methods for modelling planetary systems implemented in C/CUDA

    NASA Astrophysics Data System (ADS)

    Hellmich, S.; Mottola, S.; Hahn, G.; Kührt, E.; Hlawitschka, M.

    2014-07-01

    Simulations of dynamical processes in planetary systems represent an important tool for studying the orbital evolution of the systems [1--3]. Using modern numerical integration methods, it is possible to model systems containing many thousands of objects over timescales of several hundred million years. However, in general, supercomputers are needed to get reasonable simulation results in acceptable execution times [3]. To exploit the ever-growing computation power of Graphics Processing Units (GPUs) in modern desktop computers, we implemented cuSwift, a library of numerical integration methods for studying long-term dynamical processes in planetary systems. cuSwift can be seen as a re-implementation of the famous SWIFT integrator package written by Hal Levison and Martin Duncan. cuSwift is written in C/CUDA and contains different integration methods for various purposes. So far, we have implemented three algorithms: a 15th-order Radau integrator [4], the Wisdom-Holman Mapping (WHM) integrator [5], and the Regularized Mixed Variable Symplectic (RMVS) Method [6]. These algorithms treat only the planets as mutually gravitationally interacting bodies whereas asteroids and comets (or other minor bodies of interest) are treated as massless test particles which are gravitationally influenced by the massive bodies but do not affect each other or the massive bodies. The main focus of this work is on the symplectic methods (WHM and RMVS) which use a larger time step and thus are capable of integrating many particles over a large time span. As an additional feature, we implemented the non-gravitational Yarkovsky effect as described by M. Brož [7]. With cuSwift, we show that the use of modern GPUs makes it possible to speed up these methods by more than one order of magnitude compared to the single-core CPU implementation, thereby enabling modest workstation computers to perform long-term dynamical simulations. We use these methods to study the influence of the Yarkovsky

  18. A Case Study of a Mixed Methods Study Engaged in Integrated Data Analysis

    ERIC Educational Resources Information Center

    Schiazza, Daniela Marie

    2013-01-01

    The nascent field of mixed methods research has yet to develop a cohesive framework of guidelines and procedures for mixed methods data analysis (Greene, 2008). To support the field's development of analytical frameworks, this case study reflects on the development and implementation of a mixed methods study engaged in integrated data analysis.…

  19. Method for observing phase objects without halos and directional shadows

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi

    2015-03-01

    A new microscopy method for observing phase objects without halos and directional shadows is proposed. The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter than those used in standard phase contrast microscopy. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. This paper presents essential conditions for realizing the method. In this paper, images of colonies formed by induced pluripotent stem (iPS) cells using this method are compared with the conventional phase contrast method and the bright-field method when the NA of the illumination is small to identify differences among these techniques. The outlines of the iPS cells are clearly visible with this method, whereas they are not clearly visible due to halos when using the phase contrast method or due to weak contrast when using the bright-field method. Other images using this method are also presented to demonstrate a capacity of this method: a mouse ovum and superimposition of several different images of mouse iPS cells.

  20. Application of Numerical Integration and Data Fusion in Unit Vector Method

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2012-01-01

    The Unit Vector Method (UVM) is a series of orbit determination methods which are designed by Purple Mountain Observatory (PMO) and have been applied extensively. It gets the conditional equations for different kinds of data by projecting the basic equation to different unit vectors, and it suits for weighted process for different kinds of data. The high-precision data can play a major role in orbit determination, and accuracy of orbit determination is improved obviously. The improved UVM (PUVM2) promoted the UVM from initial orbit determination to orbit improvement, and unified the initial orbit determination and orbit improvement dynamically. The precision and efficiency are improved further. In this thesis, further research work has been done based on the UVM: Firstly, for the improvement of methods and techniques for observation, the types and decision of the observational data are improved substantially, it is also asked to improve the decision of orbit determination. The analytical perturbation can not meet the requirement. So, the numerical integration for calculating the perturbation has been introduced into the UVM. The accuracy of dynamical model suits for the accuracy of the real data, and the condition equations of UVM are modified accordingly. The accuracy of orbit determination is improved further. Secondly, data fusion method has been introduced into the UVM. The convergence mechanism and the defect of weighted strategy have been made clear in original UVM. The problem has been solved in this method, the calculation of approximate state transition matrix is simplified and the weighted strategy has been improved for the data with different dimension and different precision. Results of orbit determination of simulation and real data show that the work of this thesis is effective: (1) After the numerical integration has been introduced into the UVM, the accuracy of orbit determination is improved obviously, and it suits for the high-accuracy data of

  1. Direct spectrophotometric method for analysis of food supplements containing synthetic polyhydroquinones

    NASA Astrophysics Data System (ADS)

    Vasilevsky, A. M.; Konoplev, G. A.; Stepanova, O. S.; Toropov, D. K.; Zagorsky, A. L.

    2016-04-01

    A novel direct spectrophotometric method for quantitative determination of Oxiphore® drug substance (synthetic polyhydroquinone complex) in food supplements is developed. Absorption spectra of Oxiphore® water solutions in the ultraviolet region are presented. Samples preparation procedures and mathematical methods of spectra post-analytical procession are discussed. Basic characteristics of the automatic CCD-based UV spectrophotometer and special software implementing the developed method are described. The results of the trials of the developed method and software are analyzed: the error of determination for Oxiphore® concentration in water solutions of the isolated substance and singlecomponent food supplements did not exceed 15% (average error was 7…10%).

  2. An integrated method for atherosclerotic carotid plaque segmentation in ultrasound image.

    PubMed

    Qian, Chunjun; Yang, Xiaoping

    2018-01-01

    Carotid artery atherosclerosis is an important cause of stroke. Ultrasound imaging has been widely used in the diagnosis of atherosclerosis. Therefore, segmenting atherosclerotic carotid plaque in ultrasound image is an important task. Accurate plaque segmentation is helpful for the measurement of carotid plaque burden. In this paper, we propose and evaluate a novel learning-based integrated framework for plaque segmentation. In our study, four different classification algorithms, along with the auto-context iterative algorithm, were employed to effectively integrate features from ultrasound images and later also the iteratively estimated and refined probability maps together for pixel-wise classification. The four classification algorithms were support vector machine with linear kernel, support vector machine with radial basis function kernel, AdaBoost and random forest. The plaque segmentation was implemented in the generated probability map. The performance of the four different learning-based plaque segmentation methods was tested on 29 B-mode ultrasound images. The evaluation indices for our proposed methods were consisted of sensitivity, specificity, Dice similarity coefficient, overlap index, error of area, absolute error of area, point-to-point distance, and Hausdorff point-to-point distance, along with the area under the ROC curve. The segmentation method integrated the random forest and an auto-context model obtained the best results (sensitivity 80.4 ± 8.4%, specificity 96.5 ± 2.0%, Dice similarity coefficient 81.0 ± 4.1%, overlap index 68.3 ± 5.8%, error of area -1.02 ± 18.3%, absolute error of area 14.7 ± 10.9%, point-to-point distance 0.34 ± 0.10 mm, Hausdorff point-to-point distance 1.75 ± 1.02 mm, and area under the ROC curve 0.897), which were almost the best, compared with that from the existed methods. Our proposed learning-based integrated framework investigated in this study could be useful for

  3. Integrated anode structure for passive direct methanol fuel cells with neat methanol operation

    NASA Astrophysics Data System (ADS)

    Wu, Huijuan; Zhang, Haifeng; Chen, Peng; Guo, Jing; Yuan, Ting; Zheng, Junwei; Yang, Hui

    2014-02-01

    A microporous titanium plate based integrated anode structure (Ti-IAS) suitable for passive direct methanol fuel cells (DMFCs) fueled with neat methanol is reported. This anode structure incorporates a porous titanium plate as a methanol mass transfer barrier and current collector, pervaporation film for passively vaporizing methanol, vaporous methanol cavity for evenly distributing fuel, and channels for carbon dioxide venting. With the effective control of methanol delivery rate, the Ti-IAS based DMFC allows the direct use of neat methanol as the fuel source. In the meantime, the required water for methanol-oxidation reaction at the anode can also be fully recovered from the cathode with the help of the highly hydrophobic microporous layer in the cathode. DMFCs incorporating this new anode structure exhibit a power density as high as 40 mW cm-2 and a high volumetric energy density of 489 Wh L-1 operating with neat methanol and at 25 °C. Importantly, no obvious performance degradation of the passive DMFC system is observed after more than 90 h of continuous operation. The experimental results reveal that the compact DMFC based on the Ti-IAS exhibits a substantial potential as power sources for portable applications.

  4. Synthesis of aircraft structures using integrated design and analysis methods

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, J.; Goetz, R. C.

    1978-01-01

    A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements.

  5. Comparison of two integration methods for dynamic causal modeling of electrophysiological data.

    PubMed

    Lemaréchal, Jean-Didier; George, Nathalie; David, Olivier

    2018-06-01

    Dynamic causal modeling (DCM) is a methodological approach to study effective connectivity among brain regions. Based on a set of observations and a biophysical model of brain interactions, DCM uses a Bayesian framework to estimate the posterior distribution of the free parameters of the model (e.g. modulation of connectivity) and infer architectural properties of the most plausible model (i.e. model selection). When modeling electrophysiological event-related responses, the estimation of the model relies on the integration of the system of delay differential equations (DDEs) that describe the dynamics of the system. In this technical note, we compared two numerical schemes for the integration of DDEs. The first, and standard, scheme approximates the DDEs (more precisely, the state of the system, with respect to conduction delays among brain regions) using ordinary differential equations (ODEs) and solves it with a fixed step size. The second scheme uses a dedicated DDEs solver with adaptive step sizes to control error, making it theoretically more accurate. To highlight the effects of the approximation used by the first integration scheme in regard to parameter estimation and Bayesian model selection, we performed simulations of local field potentials using first, a simple model comprising 2 regions and second, a more complex model comprising 6 regions. In these simulations, the second integration scheme served as the standard to which the first one was compared. Then, the performances of the two integration schemes were directly compared by fitting a public mismatch negativity EEG dataset with different models. The simulations revealed that the use of the standard DCM integration scheme was acceptable for Bayesian model selection but underestimated the connectivity parameters and did not allow an accurate estimation of conduction delays. Fitting to empirical data showed that the models systematically obtained an increased accuracy when using the second

  6. Disposable photonic integrated circuits for evanescent wave sensors by ultra-high volume roll-to-roll method.

    PubMed

    Aikio, Sanna; Hiltunen, Jussi; Hiitola-Keinänen, Johanna; Hiltunen, Marianne; Kontturi, Ville; Siitonen, Samuli; Puustinen, Jarkko; Karioja, Pentti

    2016-02-08

    Flexible photonic integrated circuit technology is an emerging field expanding the usage possibilities of photonics, particularly in sensor applications, by enabling the realization of conformable devices and introduction of new alternative production methods. Here, we demonstrate that disposable polymeric photonic integrated circuit devices can be produced in lengths of hundreds of meters by ultra-high volume roll-to-roll methods on a flexible carrier. Attenuation properties of hundreds of individual devices were measured confirming that waveguides with good and repeatable performance were fabricated. We also demonstrate the applicability of the devices for the evanescent wave sensing of ambient refractive index. The production of integrated photonic devices using ultra-high volume fabrication, in a similar manner as paper is produced, may inherently expand methods of manufacturing low-cost disposable photonic integrated circuits for a wide range of sensor applications.

  7. Path integration of head direction: updating a packet of neural activity at the correct speed using neuronal time constants.

    PubMed

    Walters, D M; Stringer, S M

    2010-07-01

    A key question in understanding the neural basis of path integration is how individual, spatially responsive, neurons may self-organize into networks that can, through learning, integrate velocity signals to update a continuous representation of location within an environment. It is of vital importance that this internal representation of position is updated at the correct speed, and in real time, to accurately reflect the motion of the animal. In this article, we present a biologically plausible model of velocity path integration of head direction that can solve this problem using neuronal time constants to effect natural time delays, over which associations can be learned through associative Hebbian learning rules. The model comprises a linked continuous attractor network and competitive network. In simulation, we show that the same model is able to learn two different speeds of rotation when implemented with two different values for the time constant, and without the need to alter any other model parameters. The proposed model could be extended to path integration of place in the environment, and path integration of spatial view.

  8. A Survey of Symplectic and Collocation Integration Methods for Orbit Propagation

    NASA Technical Reports Server (NTRS)

    Jones, Brandon A.; Anderson, Rodney L.

    2012-01-01

    Demands on numerical integration algorithms for astrodynamics applications continue to increase. Common methods, like explicit Runge-Kutta, meet the orbit propagation needs of most scenarios, but more specialized scenarios require new techniques to meet both computational efficiency and accuracy needs. This paper provides an extensive survey on the application of symplectic and collocation methods to astrodynamics. Both of these methods benefit from relatively recent theoretical developments, which improve their applicability to artificial satellite orbit propagation. This paper also details their implementation, with several tests demonstrating their advantages and disadvantages.

  9. [Computerized monitoring for integrated cervical screening. Rationale, methods and indicators of participation].

    PubMed

    Bucchi, L; Pierri, C; Caprara, L; Cortecchia, S; De Lillo, M; Bondi, A

    2003-02-01

    This paper presents a computerised system for the monitoring of integrated cervical screening, i.e. the integration of spontaneous Pap smear practice into organised screening. The general characteristics of the system are described, including background and rationale (integrated cervical screening in European countries, impact of integration on monitoring, decentralised organization of screening and levels of monitoring), general methods (definitions, sections, software description, and setting of application), and indicators of participation (distribution by time interval since previous Pap smear, distribution by screening sector--organised screening centres vs public and private clinical settings--, distribution by time interval between the last two Pap smears, and movement of women between the two screening sectors). Also, the paper reports the results of the application of these indicators in the general database of the Pathology Department of Imola Health District in northern Italy.

  10. Integration of experimental and computational methods for identifying geometric, thermal and diffusive properties of biomaterials

    NASA Astrophysics Data System (ADS)

    Weres, Jerzy; Kujawa, Sebastian; Olek, Wiesław; Czajkowski, Łukasz

    2016-04-01

    Knowledge of physical properties of biomaterials is important in understanding and designing agri-food and wood processing industries. In the study presented in this paper computational methods were developed and combined with experiments to enhance identification of agri-food and forest product properties, and to predict heat and water transport in such products. They were based on the finite element model of heat and water transport and supplemented with experimental data. Algorithms were proposed for image processing, geometry meshing, and inverse/direct finite element modelling. The resulting software system was composed of integrated subsystems for 3D geometry data acquisition and mesh generation, for 3D geometry modelling and visualization, and for inverse/direct problem computations for the heat and water transport processes. Auxiliary packages were developed to assess performance, accuracy and unification of data access. The software was validated by identifying selected properties and using the estimated values to predict the examined processes, and then comparing predictions to experimental data. The geometry, thermal conductivity, specific heat, coefficient of water diffusion, equilibrium water content and convective heat and water transfer coefficients in the boundary layer were analysed. The estimated values, used as an input for simulation of the examined processes, enabled reduction in the uncertainty associated with predictions.

  11. Integrating Multiple Teaching Methods into a General Chemistry Classroom

    NASA Astrophysics Data System (ADS)

    Francisco, Joseph S.; Nicoll, Gayle; Trautmann, Marcella

    1998-02-01

    In addition to the traditional lecture format, three other teaching strategies (class discussions, concept maps, and cooperative learning) were incorporated into a freshman level general chemistry course. Student perceptions of their involvement in each of the teaching methods, as well as their perceptions of the utility of each method were used to assess the effectiveness of the integration of the teaching strategies as received by the students. Results suggest that each strategy serves a unique purpose for the students and increased student involvement in the course. These results indicate that the multiple teaching strategies were well received by the students and that all teaching strategies are necessary for students to get the most out of the course.

  12. Analysis and development of adjoint-based h-adaptive direct discontinuous Galerkin method for the compressible Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Cheng, Jian; Yue, Huiqiang; Yu, Shengjiao; Liu, Tiegang

    2018-06-01

    In this paper, an adjoint-based high-order h-adaptive direct discontinuous Galerkin method is developed and analyzed for the two dimensional steady state compressible Navier-Stokes equations. Particular emphasis is devoted to the analysis of the adjoint consistency for three different direct discontinuous Galerkin discretizations: including the original direct discontinuous Galerkin method (DDG), the direct discontinuous Galerkin method with interface correction (DDG(IC)) and the symmetric direct discontinuous Galerkin method (SDDG). Theoretical analysis shows the extra interface correction term adopted in the DDG(IC) method and the SDDG method plays a key role in preserving the adjoint consistency. To be specific, for the model problem considered in this work, we prove that the original DDG method is not adjoint consistent, while the DDG(IC) method and the SDDG method can be adjoint consistent with appropriate treatment of boundary conditions and correct modifications towards the underlying output functionals. The performance of those three DDG methods is carefully investigated and evaluated through typical test cases. Based on the theoretical analysis, an adjoint-based h-adaptive DDG(IC) method is further developed and evaluated, numerical experiment shows its potential in the applications of adjoint-based adaptation for simulating compressible flows.

  13. Integration of gas chromatography mass spectrometry methods for differentiating ricin preparation methods.

    PubMed

    Wunschel, David S; Melville, Angela M; Ehrhardt, Christopher J; Colburn, Heather A; Victry, Kristin D; Antolick, Kathryn C; Wahl, Jon H; Wahl, Karen L

    2012-05-07

    The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of Ricinus communis, commonly known as the castor plant. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatography-mass spectrometry (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid, as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods, starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid, or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method, independent of the seed source. In particular, the abundance of mannose, arabinose, fucose, ricinoleic acid, and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation than would be possible using a single analytical method.

  14. Integration of Gas Chromatography Mass Spectrometry Methods for Differentiating Ricin Preparation Methods

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wunschel, David S.; Melville, Angela M.; Ehrhardt, Christopher J.

    2012-05-17

    The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of the castor plant Ricinus communis. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatographicmore » - mass spectrometric (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method and independent of the seed source. In particular the abundance of mannose, arabinose, fucose, ricinoleic acid and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation.« less

  15. Accuracy assessment methods of tissue marker clip placement after 11-gauge vacuum-assisted stereotactic breast biopsy: comparison of measurements using direct and conventional methods.

    PubMed

    Yatake, Hidetoshi; Sawai, Yuka; Nishi, Toshio; Nakano, Yoshiaki; Nishimae, Ayaka; Katsuda, Toshizo; Yabunaka, Koichi; Takeda, Yoshihiro; Inaji, Hideo

    2017-07-01

    The objective of the study was to compare direct measurement with a conventional method for evaluation of clip placement in stereotactic vacuum-assisted breast biopsy (ST-VAB) and to evaluate the accuracy of clip placement using the direct method. Accuracy of clip placement was assessed by measuring the distance from a residual calcification of a targeted calcification clustered to a clip on a mammogram after ST-VAB. Distances in the craniocaudal (CC) and mediolateral oblique (MLO) views were measured in 28 subjects with mammograms recorded twice or more after ST-VAB. The difference in the distance between the first and second measurements was defined as the reproducibility and was compared with that from a conventional method using a mask system with overlap of transparent film on the mammogram. The 3D clip-to-calcification distance was measured using the direct method in 71 subjects. The reproducibility of the direct method was higher than that of the conventional method in CC and MLO views (P = 0.002, P < 0.001). The median 3D clip-to-calcification distance was 2.8 mm, with an interquartile range of 2.0-4.8 mm and a range of 1.1-36.3 mm. The direct method used in this study was more accurate than the conventional method, and gave a median 3D distance of 2.8 mm between the calcification and clip.

  16. Determining Directional Dependency in Causal Associations

    PubMed Central

    Pornprasertmanit, Sunthud; Little, Todd D.

    2014-01-01

    Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of skewness and excessive kurtosis of both variables, discouraging the use of D’Agostino’s K2, and encouraging the use of directional dependency to compare variables only within time points. We offer improved steps for determining directional dependency that fix the problems we note. Next, we discuss how to integrate directional dependency into longitudinal data analysis with two variables. We also examine the accuracy of directional dependency evaluations when several regression assumptions are violated. Directional dependency can suggest the direction of a relation if (a) the regression error in population is normal, (b) an unobserved explanatory variable correlates with any variables equal to or less than .2, (c) a curvilinear relation between both variables is not strong (standardized regression coefficient ≤ .2), (d) there are no bivariate outliers, and (e) both variables are continuous. PMID:24683282

  17. Triangulation and Mixed Methods Designs: Data Integration with New Research Technologies

    ERIC Educational Resources Information Center

    Fielding, Nigel G.

    2012-01-01

    Data integration is a crucial element in mixed methods analysis and conceptualization. It has three principal purposes: illustration, convergent validation (triangulation), and the development of analytic density or "richness." This article discusses such applications in relation to new technologies for social research, looking at three…

  18. Method of fabricating a microelectronic device package with an integral window

    DOEpatents

    Peterson, Kenneth A.; Watson, Robert D.

    2003-01-01

    A method of fabricating a microelectronic device package with an integral window for providing optical access through an aperture in the package. The package is made of a multilayered insulating material, e.g., a low-temperature cofired ceramic (LTCC) or high-temperature cofired ceramic (HTCC). The window is inserted in-between personalized layers of ceramic green tape during stackup and registration. Then, during baking and firing, the integral window is simultaneously bonded to the sintered ceramic layers of the densified package. Next, the microelectronic device is flip-chip bonded to cofired thick-film metallized traces on the package, where the light-sensitive side is optically accessible through the window. Finally, a cover lid is attached to the opposite side of the package. The result is a compact, low-profile package, flip-chip bonded, hermetically-sealed package having an integral window.

  19. Hot Press as a Sustainable Direct Recycling Technique of Aluminium: Mechanical Properties and Surface Integrity

    PubMed Central

    Lajis, Mohd Amri; Ahmad, Azlan

    2017-01-01

    Meltless recycling technique has been utilized to overcome the lack of primary resources, focusing on reducing the usage of energy and materials. Hot press was proposed as a novel direct recycling technique which results in astoundingly low energy usage in contrast with conventional recycling. The aim of this study is to prove the technical feasibility of this approach by characterizing the recycled samples. For this purpose, AA6061 aluminium chips were recycled by utilizing hot press process under various operating temperature (Ts = 430, 480, and 530 °C) and holding times (ts = 60, 90, and 120 min). The maximum mechanical properties of recycled chip are Ultimate tensile strength (UTS) = 266.78 MPa, Elongation to failure (ETF) = 16.129%, while, for surface integrity of the chips, the calculated microhardness is 81.744 HV, exhibited at Ts = 530 °C and ts = 120 min. It is comparable to theoretical AA6061 T4-temper where maximum UTS and microhardness is increased up to 9.27% and 20.48%, respectively. As the desired mechanical properties of forgings can only be obtained by means of a final heat treatment, T5-temper, aging after forging process was employed. Heat treated recycled billet AA6061 (T5-temper) are considered comparable with as-received AA6061 T6, where the value of microhardness (98.649 HV) at 175 °C and 120 min of aging condition was revealed to be greater than 3.18%. Although it is quite early to put a base mainly on the observations in experimental settings, the potential for significant improvement offered by the direct recycling methods for production aluminium scrap can be clearly demonstrated. This overtures perspectives for industrial development of solid state recycling processes as environmentally benign alternatives of current melting based practices. PMID:28771207

  20. Hot Press as a Sustainable Direct Recycling Technique of Aluminium: Mechanical Properties and Surface Integrity.

    PubMed

    Yusuf, Nur Kamilah; Lajis, Mohd Amri; Ahmad, Azlan

    2017-08-03

    Meltless recycling technique has been utilized to overcome the lack of primary resources, focusing on reducing the usage of energy and materials. Hot press was proposed as a novel direct recycling technique which results in astoundingly low energy usage in contrast with conventional recycling. The aim of this study is to prove the technical feasibility of this approach by characterizing the recycled samples. For this purpose, AA6061 aluminium chips were recycled by utilizing hot press process under various operating temperature (T s = 430, 480, and 530 °C) and holding times (t s = 60, 90, and 120 min). The maximum mechanical properties of recycled chip are Ultimate tensile strength (UTS) = 266.78 MPa, Elongation to failure (ETF) = 16.129%, while, for surface integrity of the chips, the calculated microhardness is 81.744 HV, exhibited at T s = 530 °C and t s = 120 min. It is comparable to theoretical AA6061 T4-temper where maximum UTS and microhardness is increased up to 9.27% and 20.48%, respectively. As the desired mechanical properties of forgings can only be obtained by means of a final heat treatment, T5-temper, aging after forging process was employed. Heat treated recycled billet AA6061 (T5-temper) are considered comparable with as-received AA6061 T6, where the value of microhardness (98.649 HV) at 175 °C and 120 min of aging condition was revealed to be greater than 3.18%. Although it is quite early to put a base mainly on the observations in experimental settings, the potential for significant improvement offered by the direct recycling methods for production aluminium scrap can be clearly demonstrated. This overtures perspectives for industrial development of solid state recycling processes as environmentally benign alternatives of current melting based practices.