WorldWideScience

Sample records for all-atom structure validation

  1. An All-atom Structure-Based Potential for Proteins: Bridging Minimal Models with All-atom Empirical Forcefields

    OpenAIRE

    Whitford, Paul C.; Jeffrey K Noel; Gosavi, Shachi; Schug, Alexander; Sanbonmatsu, Kevin Y.; Onuchic, José N.

    2009-01-01

    Protein dynamics take place on many time and length scales. Coarse-grained structure-based (Gō) models utilize the funneled energy landscape theory of protein folding to provide an understanding of both long time and long length scale dynamics. All-atom empirical forcefields with explicit solvent can elucidate our understanding of short time dynamics with high energetic and structural resolution. Thus, structure-based models with atomic details included can be used to bridge our understanding...

  2. The Dependence of All-Atom Statistical Potentials on Structural Training Database

    OpenAIRE

    Zhang, Chi; Liu, Song; Zhou, Hongyi; Zhou, Yaoqi

    2004-01-01

    An accurate statistical energy function that is suitable for the prediction of protein structures of all classes should be independent of the structural database used for energy extraction. Here, two high-resolution, low-sequence-identity structural databases of 333 α-proteins and 271 β-proteins were built for examining the database dependence of three all-atom statistical energy functions. They are RAPDF (residue-specific all-atom conditional probability discriminatory function), atomic KBP ...

  3. GOAP: A Generalized Orientation-Dependent, All-Atom Statistical Potential for Protein Structure Prediction

    OpenAIRE

    Zhou, Hongyi; Skolnick, Jeffrey

    2011-01-01

    An accurate scoring function is a key component for successful protein structure prediction. To address this important unsolved problem, we develop a generalized orientation and distance-dependent all-atom statistical potential. The new statistical potential, generalized orientation-dependent all-atom potential (GOAP), depends on the relative orientation of the planes associated with each heavy atom in interacting pairs. GOAP is a generalization of previous orientation-dependent potentials th...

  4. A Real-Time All-Atom Structural Search Engine for Proteins

    OpenAIRE

    Gonzalez, Gabriel; Hannigan, Brett; DeGrado, William F.

    2014-01-01

    Protein designers use a wide variety of software tools for de novo design, yet their repertoire still lacks a fast and interactive all-atom search engine. To solve this, we have built the Suns program: a real-time, atomic search engine integrated into the PyMOL molecular visualization system. Users build atomic-level structural search queries within PyMOL and receive a stream of search results aligned to their query within a few seconds. This instant feedback cycle enables a new “designabilit...

  5. A real-time all-atom structural search engine for proteins.

    Directory of Open Access Journals (Sweden)

    Gabriel Gonzalez

    2014-07-01

    Full Text Available Protein designers use a wide variety of software tools for de novo design, yet their repertoire still lacks a fast and interactive all-atom search engine. To solve this, we have built the Suns program: a real-time, atomic search engine integrated into the PyMOL molecular visualization system. Users build atomic-level structural search queries within PyMOL and receive a stream of search results aligned to their query within a few seconds. This instant feedback cycle enables a new "designability"-inspired approach to protein design where the designer searches for and interactively incorporates native-like fragments from proven protein structures. We demonstrate the use of Suns to interactively build protein motifs, tertiary interactions, and to identify scaffolds compatible with hot-spot residues. The official web site and installer are located at http://www.degradolab.org/suns/ and the source code is hosted at https://github.com/godotgildor/Suns (PyMOL plugin, BSD license, https://github.com/Gabriel439/suns-cmd (command line client, BSD license, and https://github.com/Gabriel439/suns-search (search engine server, GPLv2 license.

  6. All-Atom Structural Models of the Transmembrane Domains of Insulin and Type 1 Insulin-Like Growth Factor Receptors

    Science.gov (United States)

    Mohammadiarani, Hossein; Vashisth, Harish

    2016-01-01

    The receptor tyrosine kinase superfamily comprises many cell-surface receptors including the insulin receptor (IR) and type 1 insulin-like growth factor receptor (IGF1R) that are constitutively homodimeric transmembrane glycoproteins. Therefore, these receptors require ligand-triggered domain rearrangements rather than receptor dimerization for activation. Specifically, binding of peptide ligands to receptor ectodomains transduces signals across the transmembrane domains for trans-autophosphorylation in cytoplasmic kinase domains. The molecular details of these processes are poorly understood in part due to the absence of structures of full-length receptors. Using MD simulations and enhanced conformational sampling algorithms, we present all-atom structural models of peptides containing 51 residues from the transmembrane and juxtamembrane regions of IR and IGF1R. In our models, the transmembrane regions of both receptors adopt helical conformations with kinks at Pro961 (IR) and Pro941 (IGF1R), but the C-terminal residues corresponding to the juxtamembrane region of each receptor adopt unfolded and flexible conformations in IR as opposed to a helix in IGF1R. We also observe that the N-terminal residues in IR form a kinked-helix sitting at the membrane–solvent interface, while homologous residues in IGF1R are unfolded and flexible. These conformational differences result in a larger tilt-angle of the membrane-embedded helix in IGF1R in comparison to IR to compensate for interactions with water molecules at the membrane–solvent interfaces. Our metastable/stable states for the transmembrane domain of IR, observed in a lipid bilayer, are consistent with a known NMR structure of this domain determined in detergent micelles, and similar states in IGF1R are consistent with a previously reported model of the dimerized transmembrane domains of IGF1R. Our all-atom structural models suggest potentially unique structural organization of kinase domains in each receptor. PMID

  7. Structure and Function of Photosystem I-[FeFe] Hydrogenase Protein Fusions: An All-Atom Molecular Dynamics Study.

    Science.gov (United States)

    Harris, Bradley J; Cheng, Xiaolin; Frymier, Paul

    2016-02-01

    All-atom molecular dynamics (MD) simulation was used to study the solution dynamics and protein-protein interactions of protein fusions of photosystem I (PSI) from Thermosynechococcus elongatus and an [FeFe]-hydrogenase (FeFe H2ase) from Clostridium pasteurianum, a unique complex capable of photocatalytic hydrogen production. This study involved fusions of these two proteins via dithiol linkers of different length including decanedithiol, octanedithiol, and hexanedithiol, for which experimental data had previously been obtained. Evaluation of root-mean-squared deviations (RMSDs) relative to the respective crystal structures of PSI and the FeFe H2ase shows that these fusion complexes approach stable equilibrium conformations during the MD simulations. Investigating protein mobility via root-mean-squared fluctuations (RMSFs) reveals that tethering via the shortest hexanedithiol linker results in increased atomic fluctuations of both PSI and the hydrogenase in these fusion complexes. Evaluation of the inter- and intraprotein electron transfer distances in these fusion complexes indicates that the structural changes in the FeFe H2ase arising from ligation to PSI via the shortest hexanedithiol linker may hinder electron transport in the hydrogenase, thus providing a molecular level explanation for the observation that the medium-length octanedithiol linker gives the highest hydrogen production rate. PMID:26671167

  8. Development and application of all-atom structure-based models for studying the role of geometry in biomolecular folding and function

    OpenAIRE

    Noel, Jeffrey Kenneth

    2012-01-01

    Protein dynamics takes place on a rugged funnel-like energy landscape that is biased towards the native state. In naturally occurring proteins, this ruggedness caused by non-native interactions is sufficiently smooth (minimally frustrated) that the landscape is dominated by the native interactions. This provides the theoretical foundation for a class of minimalist protein models called structure- based models (SBMs). In the first half of the thesis we develop and characterize an all-atom SBM ...

  9. An all-atom model of the chromatin fiber containing linker histones reveals a versatile structure tuned by the nucleosomal repeat length.

    Directory of Open Access Journals (Sweden)

    Hua Wong

    Full Text Available In the nucleus of eukaryotic cells, histone proteins organize the linear genome into a functional and hierarchical architecture. In this paper, we use the crystal structures of the nucleosome core particle, B-DNA and the globular domain of H5 linker histone to build the first all-atom model of compact chromatin fibers. In this 3D jigsaw puzzle, DNA bending is achieved by solving an inverse kinematics problem. Our model is based on recent electron microscopy measurements of reconstituted fiber dimensions. Strikingly, we find that the chromatin fiber containing linker histones is a polymorphic structure. We show that different fiber conformations are obtained by tuning the linker histone orientation at the nucleosomes entry/exit according to the nucleosomal repeat length. We propose that the observed in vivo quantization of nucleosomal repeat length could reflect nature's ability to use the DNA molecule's helical geometry in order to give chromatin versatile topological and mechanical properties.

  10. Systematic Assessment of the Effects of an All-Atom Force Field and the Implicit Solvent Model on the Refinement of NMR Structures with Subsets of Distance Restraints

    International Nuclear Information System (INIS)

    Employment of a time consuming, sophisticated calculation using the all-atom force field and generalized-Born implicit solvent model (GBIS) for refinement of NMR structures has become practical through advances in computational methods and capacities. GBIS refinement improves the qualities of the resulting NMR structures with reduced computational times. However, the contribution of GBIS to NMR structures has not been sufficiently studied in a quantitative way. In this paper, we report the effects of GBIS on the refined NMR structures of ubiquitin (UBQ) and GB1 with subsets of distance restraints derived from experimental data. Random omission prepared a series of distance restraints 0.05, 0.1, 0.3, 0.5, and 0.7 times smaller. For each number, we produced five different restraints for statistical analysis. We then recalculated the NMR structures using CYANA software, followed by GBIS refinements using the AMBER package. GBIS improved both the precision and accuracy of all the structures, but to varied levels. The degrees of improvement were significant when the input restraints were insufficient. In particular, GBIS enabled GB1 to form an accurate structure even with distance restraints of 5%, revealing that the root-mean-square deviation was less than 1 A from the X-ray backbone structure. We also showed that the efficiency of searching the conformational space was more important for finding accurate structures with the calculation of UBQ with 5% distance restraints than the number of conformations generated. Our data will provide a meaningful guideline to judge and compare the structural improvements by GBIS

  11. Effect of water on structure and dynamics of [BMIM][PF6] ionic liquid: An all-atom molecular dynamics simulation investigation

    Science.gov (United States)

    Sharma, Anirban; Ghorai, Pradip Kr.

    2016-03-01

    Composition dependent structural and dynamical properties of aqueous hydrophobic 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) ionic liquid (IL) have been investigated by using all-atom molecular dynamics simulation. We observe that addition of water does not increase significant number of dissociated ions in the solution over the pure state. As a consequence, self-diffusion coefficient of the cation and anion is comparable to each other at all water concentration similar to that is observed for the pure state. Voronoi polyhedra analysis exhibits strong dependence on the local environment of IL concentration. Void and neck distributions in Voronoi tessellation are approximately Gaussian for pure IL but upon subsequent addition of water, we observe deviation from the Gaussian behaviour with an asymmetric broadening with long tail of exponential decay at large void radius, particularly at higher water concentrations. The increase in void space and neck size at higher water concentration facilitates ionic motion, thus, decreasing dynamical heterogeneity and IL reorientation time and increases self-diffusion coefficient significantly.

  12. Structural Interpretation of the Large Slowdown of Water Dynamics at Stacked Phospholipid Membranes for Decreasing Hydration Level: All-Atom Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Carles Calero

    2016-04-01

    Full Text Available Hydration water determines the stability and function of phospholipid membranes as well as the interaction of membranes with other molecules. Experiments and simulations have shown that water dynamics slows down dramatically as the hydration decreases, suggesting that the interfacial water that dominates the average dynamics at low hydration is slower than water away from the membrane. Here, based on all-atom molecular dynamics simulations, we provide an interpretation of the slowdown of interfacial water in terms of the structure and dynamics of water–water and water–lipid hydrogen bonds (HBs. We calculate the rotational and translational slowdown of the dynamics of water confined in stacked phospholipid membranes at different levels of hydration, from completely hydrated to poorly hydrated membranes. For all hydrations, we analyze the distribution of HBs and find that water–lipids HBs last longer than water–water HBs and that at low hydration most of the water is in the interior of the membrane. We also show that water–water HBs become more persistent as the hydration is lowered. We attribute this effect (i to HBs between water molecules that form, in turn, persistent HBs with lipids; (ii to the hindering of the H-bonding switching between water molecules due to the lower water density at the interface; and (iii to the higher probability of water–lipid HBs as the hydration decreases. Our interpretation of the large dynamic slowdown in water under dehydration is potentially relevant in understanding membrane biophysics at different hydration levels.

  13. Protein simulations combining an all-atom force field with a Go term

    International Nuclear Information System (INIS)

    Using a variant of parallel tempering, we study the changes in sampling within a simulation, when the all-atom model is coupled to a Go-like potential. We find that the native structure is not the lowest-energy configuration in the all-atom force field. Adding a Go term deforms the energy landscape in such a way that the native configuration becomes the global minimum but does not lead to faster thermalization

  14. Structural system identification: Structural dynamics model validation

    Energy Technology Data Exchange (ETDEWEB)

    Red-Horse, J.R.

    1997-04-01

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  15. Development and application of a free energy force field for all atom protein folding

    International Nuclear Information System (INIS)

    Proteins are the workhorses of all cellular life. They constitute the building blocks and the machinery of all cells and typically function in specific three-dimensional conformations into which each protein folds. Currently over one million protein sequences are known, compared to about 40,000 structures deposited in the Protein Data Bank (the world-wide database of protein structures). Reliable theoretical methods for protein structure prediction could help to reduce the gap between sequence and structural databases and elucidate the biological information in structurally unresolved sequences. In this thesis we explore an approach for protein structure prediction and folding that is based on the Anfinsen's hypothesis that most proteins in their native state are in thermodynamic equilibrium with their environment. We have developed a free energy forcefield (PFF02) that locates the native conformation of many proteins from all structural classes at the global minimum of the free-energy model. We have validated the forcefield against a large decoy set (Rosetta). The average root mean square deviation (RMSD) for the lowest energy structure for the 32 proteins of the decoy set was only 2.14 Aa from the experimental conformation. We have successfully implemented and used stochastic optimization methods, such as the basin hopping technique and evolutionary algorithms for all atom protein structure prediction. The evolutionary algorithm performs exceptionally well on large supercomputational architectures, such as BlueGene and MareNostrum. Using the PFF02 forcefield, we were able to fold 13 proteins (12-56 amino acids), which include helix, sheet and mixed secondary structure. On average the predicted structure of these proteins deviated from their experimental conformation by only 2.89 Aa RMSD. (orig.)

  16. Refined OPLS All-Atom Force Field for Saturated Phosphatidylcholine Bilayers at Full Hydration

    DEFF Research Database (Denmark)

    Maciejewski, A.; Pasenkiewicz-Gierula, M.; Cramariuc, O.; Vattulainen, I.; Rog, T.

    2014-01-01

    validation, and it is also one of the highly important and abundant lipid types, e.g., in lung surfactant. Overall, PCs have not been previously parametrized in the OPLS-AA force field; thus, there is a need to derive its bonding and nonbonding parameters for both the polar and nonpolar parts of the molecule......We report parametrization of dipalmitoyl-phosphatidylcholine (DPPC) in the framework of the Optimized Parameters for Liquid Simulations all-atom (OPLS-AA) force field. We chose DPPC as it is one of the most studied phospholipid species and thus has plenty of experimental data necessary for model...

  17. Simulation of lipid bilayer self-assembly using all-atom lipid force fields.

    Science.gov (United States)

    Skjevik, Åge A; Madej, Benjamin D; Dickson, Callum J; Lin, Charles; Teigen, Knut; Walker, Ross C; Gould, Ian R

    2016-04-21

    In this manuscript we expand significantly on our earlier communication by investigating the bilayer self-assembly of eight different types of phospholipids in unbiased molecular dynamics (MD) simulations using three widely used all-atom lipid force fields. Irrespective of the underlying force field, the lipids are shown to spontaneously form stable lamellar bilayer structures within 1 microsecond, the majority of which display properties in satisfactory agreement with the experimental data. The lipids self-assemble via the same general mechanism, though at formation rates that differ both between lipid types, force fields and even repeats on the same lipid/force field combination. In addition to zwitterionic phosphatidylcholine (PC) and phosphatidylethanolamine (PE) lipids, anionic phosphatidylserine (PS) and phosphatidylglycerol (PG) lipids are represented. To our knowledge this is the first time bilayer self-assembly of phospholipids with negatively charged head groups is demonstrated in all-atom MD simulations. PMID:27034995

  18. Combining Coarse-Grained Protein Models with Replica-Exchange All-Atom Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Andrzej Koliński

    2013-05-01

    Full Text Available We describe a combination of all-atom simulations with CABS, a well-established coarse-grained protein modeling tool, into a single multiscale protocol. The simulation method has been tested on the C-terminal beta hairpin of protein G, a model system of protein folding. After reconstructing atomistic details, conformations derived from the CABS simulation were subjected to replica-exchange molecular dynamics simulations with OPLS-AA and AMBER99sb force fields in explicit solvent. Such a combination accelerates system convergence several times in comparison with all-atom simulations starting from the extended chain conformation, demonstrated by the analysis of melting curves, the number of native-like conformations as a function of time and secondary structure propagation. The results strongly suggest that the proposed multiscale method could be an efficient and accurate tool for high-resolution studies of protein folding dynamics in larger systems.

  19. Combining Coarse-Grained Protein Models with Replica-Exchange All-Atom Molecular Dynamics

    CERN Document Server

    Wabik, Jacek; Gront, Dominik; Kouza, Maksim; Kolinski, Andrzej

    2013-01-01

    We describe a combination of all-atom simulations with CABS, a well-established coarse-grained protein modeling tool, into a single multiscale protocol. The simulation method has been tested on the C-terminal beta hairpin of protein G, a model system of protein folding. After reconstructing atomistic details, conformations derived from the CABS simulation were subjected to replica-exchange molecular dynamics simulations with OPLS-AA and AMBER99sb force fields in explicit solvent. Such a combination accelerates system convergence several times in comparison with all-atom simulations starting from the extended chain conformation, demonstrated by the analysis of melting curves, the number of native-like conformations as a function of time and secondary structure propagation. The results strongly suggest that the proposed multiscale method could be an efficient and accurate tool for high-resolution studies of protein folding dynamics in larger systems.

  20. Beyond Modeling: All-Atom Olfactory Receptor Model Simulations

    Directory of Open Access Journals (Sweden)

    Peter C Lai

    2012-05-01

    Full Text Available Olfactory receptors (ORs are a type of GTP-binding protein-coupled receptor (GPCR. These receptors are responsible for mediating the sense of smell through their interaction with odor ligands. OR-odorant interactions marks the first step in the process that leads to olfaction. Computational studies on model OR structures can validate experimental functional studies as well as generate focused and novel hypotheses for further bench investigation by providing a view of these interactions at the molecular level. Here we have shown the specific advantages of simulating the dynamic environment that is associated with OR-odorant interactions. We present a rigorous methodology that ranges from the creation of a computationally-derived model of an olfactory receptor to simulating the interactions between an OR and an odorant molecule. Given the ubiquitous occurrence of GPCRs in the membranes of cells, we anticipate that our OR-developed methodology will serve as a model for the computational structural biology of all GPCRs.

  1. Experimental validation of structural optimization methods

    Science.gov (United States)

    Adelman, Howard M.

    1992-01-01

    The topic of validating structural optimization methods by use of experimental results is addressed. The need for validating the methods as a way of effecting a greater and an accelerated acceptance of formal optimization methods by practicing engineering designers is described. The range of validation strategies is defined which includes comparison of optimization results with more traditional design approaches, establishing the accuracy of analyses used, and finally experimental validation of the optimization results. Examples of the use of experimental results to validate optimization techniques are described. The examples include experimental validation of the following: optimum design of a trussed beam; combined control-structure design of a cable-supported beam simulating an actively controlled space structure; minimum weight design of a beam with frequency constraints; minimization of the vibration response of helicopter rotor blade; minimum weight design of a turbine blade disk; aeroelastic optimization of an aircraft vertical fin; airfoil shape optimization for drag minimization; optimization of the shape of a hole in a plate for stress minimization; optimization to minimize beam dynamic response; and structural optimization of a low vibration helicopter rotor.

  2. Feature Extraction for Structural Dynamics Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles [Los Alamos National Laboratory; Nishio, Mayuko [Yokohama University; Hemez, Francois [Los Alamos National Laboratory; Stull, Chris [Los Alamos National Laboratory; Park, Gyuhae [Chonnam Univesity; Cornwell, Phil [Rose-Hulman Institute of Technology; Figueiredo, Eloi [Universidade Lusófona; Luscher, D. J. [Los Alamos National Laboratory; Worden, Keith [University of Sheffield

    2016-01-13

    As structural dynamics becomes increasingly non-modal, stochastic and nonlinear, finite element model-updating technology must adopt the broader notions of model validation and uncertainty quantification. For example, particular re-sampling procedures must be implemented to propagate uncertainty through a forward calculation, and non-modal features must be defined to analyze nonlinear data sets. The latter topic is the focus of this report, but first, some more general comments regarding the concept of model validation will be discussed.

  3. Feature extraction for structural dynamics model validation

    Energy Technology Data Exchange (ETDEWEB)

    Hemez, Francois [Los Alamos National Laboratory; Farrar, Charles [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Nishio, Mayuko [UNIV OF TOKYO; Worden, Keith [UNIV OF SHEFFIELD; Takeda, Nobuo [UNIV OF TOKYO

    2010-11-08

    This study focuses on defining and comparing response features that can be used for structural dynamics model validation studies. Features extracted from dynamic responses obtained analytically or experimentally, such as basic signal statistics, frequency spectra, and estimated time-series models, can be used to compare characteristics of structural system dynamics. By comparing those response features extracted from experimental data and numerical outputs, validation and uncertainty quantification of numerical model containing uncertain parameters can be realized. In this study, the applicability of some response features to model validation is first discussed using measured data from a simple test-bed structure and the associated numerical simulations of these experiments. issues that must be considered were sensitivity, dimensionality, type of response, and presence or absence of measurement noise in the response. Furthermore, we illustrate a comparison method of multivariate feature vectors for statistical model validation. Results show that the outlier detection technique using the Mahalanobis distance metric can be used as an effective and quantifiable technique for selecting appropriate model parameters. However, in this process, one must not only consider the sensitivity of the features being used, but also correlation of the parameters being compared.

  4. A Hierarchical Coarse-Grained (All-Atom-to-All-Residue) Computer Simulation Approach: Self-Assembly of Peptides

    OpenAIRE

    Pandey, Ras B.; Kuang, Zhifeng; Farmer, Barry L.

    2013-01-01

    A hierarchical computational approach (all-atom residue to all-residue peptide) is introduced to study self-organizing structures of peptides as a function of temperature. A simulated residue-residue interaction involving all-atom description, analogous to knowledge-based analysis (with different input), is used as an input to a phenomenological coarse-grained interaction for large scales computer simulations. A set of short peptides P1 (1H 2S 3S 4Y 5W 6Y 7A 8F 9N 10N 11K 12T) is considered a...

  5. Predicting Transcription Factor Specificity with All-Atom Models

    CERN Document Server

    Rahi, Sahand Jamal; Mirny, Leonid A; Kardar, Mehran

    2008-01-01

    The binding of a transcription factor (TF) to a DNA operator site can initiate or repress the expression of a gene. Computational prediction of sites recognized by a TF has traditionally relied upon knowledge of several cognate sites, rather than an ab initio approach. Here, we examine the possibility of using structure-based energy calculations that require no knowledge of bound sites but rather start with the structure of a protein-DNA complex. We study the PurR E. coli TF, and explore to which extent atomistic models of protein-DNA complexes can be used to distinguish between cognate and non-cognate DNA sites. Particular emphasis is placed on systematic evaluation of this approach by comparing its performance with bioinformatic methods, by testing it against random decoys and sites of homologous TFs. We also examine a set of experimental mutations in both DNA and the protein. Using our explicit estimates of energy, we show that the specificity for PurR is dominated by direct protein-DNA interactions, and w...

  6. Multiscale approach for the construction of equilibrated all-atom models of a poly(ethylene glycol)-based hydrogel.

    Science.gov (United States)

    Li, Xianfeng; Murthy, N Sanjeeva; Becker, Matthew L; Latour, Robert A

    2016-06-01

    A multiscale modeling approach is presented for the efficient construction of an equilibrated all-atom model of a cross-linked poly(ethylene glycol) (PEG)-based hydrogel using the all-atom polymer consistent force field (PCFF). The final equilibrated all-atom model was built with a systematic simulation toolset consisting of three consecutive parts: (1) building a global cross-linked PEG-chain network at experimentally determined cross-link density using an on-lattice Monte Carlo method based on the bond fluctuation model, (2) recovering the local molecular structure of the network by transitioning from the lattice model to an off-lattice coarse-grained (CG) model parameterized from PCFF, followed by equilibration using high performance molecular dynamics methods, and (3) recovering the atomistic structure of the network by reverse mapping from the equilibrated CG structure, hydrating the structure with explicitly represented water, followed by final equilibration using PCFF parameterization. The developed three-stage modeling approach has application to a wide range of other complex macromolecular hydrogel systems, including the integration of peptide, protein, and/or drug molecules as side-chains within the hydrogel network for the incorporation of bioactivity for tissue engineering, regenerative medicine, and drug delivery applications. PMID:27013229

  7. All-Atom Molecular Dynamics Simulation of Protein Translocation through an α-Hemolysin Nanopore

    KAUST Repository

    Di Marino, Daniele

    2015-08-06

    © 2015 American Chemical Society. Nanopore sensing is attracting the attention of a large and varied scientific community. One of the main issues in nanopore sensing is how to associate the measured current signals to specific features of the molecule under investigation. This is particularly relevant when the translocating molecule is a protein and the pore is sufficiently narrow to necessarily involve unfolding of the translocating protein. Recent experimental results characterized the cotranslocational unfolding of Thioredoxin (Trx) passing through an α-hemolisin pore, providing evidence for the existence of a multistep process. In this study we report the results of all-atom molecular dynamics simulations of the same system. Our data indicate that Trx translocation involves two main barriers. The first one is an unfolding barrier associated with a translocation intermediate where the N-terminal region of Trx is stuck at the pore entrance in a conformation that strongly resembles the native one. After the abrupt unfolding of the N-terminal region, the Trx enters the α-hemolisin vestibule. During this stage, the constriction is occupied not only by the translocating residue but also by a hairpin-like structure forming a tangle in the constriction. The second barrier is associated with the disentangling of this region.

  8. Molecular jamming--the cystine slipknot mechanical clamp in all-atom simulations.

    Science.gov (United States)

    Pepłowski, Lukasz; Sikora, Mateusz; Nowak, Wiesław; Cieplak, Marek

    2011-02-28

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e., by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement with previous studies within a coarse grained structure based model, the level of resistance is found to be substantially higher than in proteins in which the mechanical clamp operates through shear. The large stretching forces arise through formation of the cystine slipknot mechanical clamp and the resulting steric jamming. We elucidate the workings of such a clamp in an atomic detail. We also study the behavior of five top strength proteins with the shear-based mechanostability in which no jamming is involved. We show that in the atomic model, the jamming state is relieved by moving one amino acid at a time and there is a choice in the selection of the amino acid that advances the first. In contrast, the coarse grained model also allows for a simultaneous passage of two amino acids. PMID:21361557

  9. Molecular jamming—The cystine slipknot mechanical clamp in all-atom simulations

    Science.gov (United States)

    Pepłowski, Łukasz; Sikora, Mateusz; Nowak, Wiesław; Cieplak, Marek

    2011-02-01

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e., by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement with previous studies within a coarse grained structure based model, the level of resistance is found to be substantially higher than in proteins in which the mechanical clamp operates through shear. The large stretching forces arise through formation of the cystine slipknot mechanical clamp and the resulting steric jamming. We elucidate the workings of such a clamp in an atomic detail. We also study the behavior of five top strength proteins with the shear-based mechanostability in which no jamming is involved. We show that in the atomic model, the jamming state is relieved by moving one amino acid at a time and there is a choice in the selection of the amino acid that advances the first. In contrast, the coarse grained model also allows for a simultaneous passage of two amino acids.

  10. Accelerating all-atom MD simulations of lipids using a modified virtual-sites technique

    DEFF Research Database (Denmark)

    Loubet, Bastien; Kopec, Wojciech; Khandelia, Himanshu

    2014-01-01

    We present two new implementations of the virtual sites technique which completely suppresses the degrees of freedom of the hydrogen atoms in a lipid bilayer allowing for an increased time step of 5 fs in all-atom simulations of the CHARMM36 force field. One of our approaches uses the derivation of...

  11. Validity and factor structure of the bodybuilding dependence scale

    OpenAIRE

    Smith, D.; Hale, B

    2004-01-01

    Objectives: To investigate the factor structure, validity, and reliability of the bodybuilding dependence scale and to investigate differences in bodybuilding dependence between men and women and competitive and non-competitive bodybuilders.

  12. Folding peptides and proteins with all-atom physics: methods and applications

    Science.gov (United States)

    Shell, M. Scott

    2008-03-01

    Computational methods offer powerful tools for investigating proteins and peptides at the molecular-level; however, it has proven challenging to reproduce the long time scale folding processes of these molecules at a level that is both faithful to the atomic driving forces and attainable with modern commodity cluster computing. Alternatively, the past decade has seen significant progress in using bioinformatics-based approaches to infer the three dimensional native structures of proteins, drawing upon extensive knowledge databases of known protein structures [1]. These methods work remarkably well when a homologous protein can be found to provide a structural template for a candidate sequence. However, in cases where homology to database proteins is low, where the folding pathway is of interest, or where conformational flexibility is substantial---as in many emerging protein and peptide technologies---bioinformatics methods perform poorly. There is therefore great interest in seeing purely physics-based approaches succeed. We discuss a purely physics-based, database-free folding method, relying on proper thermal sampling (replica exchange molecular dynamics) and molecular potential energy functions. In order to surmount the tremendous computational demands of all-atom folding simulations, our approach implements a conformational search strategy based on a putative protein folding mechanism called zipping and assembly [2-4]. That is, we explicitly seek out potential folding pathways inferred from short simulations, and iteratively pursue all such routes by coaxing a polypeptide chain along them. The method is called the Zipping and Assembly Method (ZAM) and it works in two parts: (1) the full polypeptide chain is broken into small fragments that are first simulated independently and then successively re-assembled into larger segments with further sampling, and (2) consistently stable structure in fragments is detected and locked into place, in order to avoid re

  13. Laser Vibrometry Helps to Validate Gossamer Space Structures

    Science.gov (United States)

    Gaspar, James L.

    2006-01-01

    NASA is pursuing the development of large ultra-lightweight structures, commonly referred to as gossamer space structures. These structures have large areas and small areal densities, which complicates ground testing significantly as the ground operations interfaces and gravity loading can become cumbersome. Laser vibrometry has proven to be a critical sensing technology for validating the structural characteristics of these gossamer structures, due to its precision, range, and non-contacting nature.

  14. Validation of seismic soil-structure interaction

    International Nuclear Information System (INIS)

    Simulated earthquake tests were conducted on centrifuged model structures embedded in dry and saturated sand foundations. Accelerations and pore water pressures were recorded at many locations during the test. Model responses were analyzed using the program TARA-3 which incorporates a procedure for nonlinear dynamic effective stress analysis. Computed and measured responses agreed quite closely. (author)

  15. Coupling all-atom molecular dynamics simulations of ions in water with Brownian dynamics

    CERN Document Server

    Erban, Radek

    2015-01-01

    Molecular dynamics (MD) simulations of ions (K$^+$, Na$^+$, Ca$^{2+}$ and Cl$^-$) in aqueous solutions are investigated. Water is described using the SPC/E model. A stochastic coarse-grained description for ion behaviour is presented and parameterized using MD simulations. It is given as a system of coupled stochastic and ordinary differential equations, describing the ion position, velocity and acceleration. The stochastic coarse-grained model provides an intermediate description between all-atom MD simulations and Brownian dynamics (BD) models. It is used to develop a multiscale method which uses all-atom MD simulations in parts of the computational domain and (less detailed) BD simulations in the remainder of the domain.

  16. The psychiatric interview: validity, structure, and subjectivity

    OpenAIRE

    NORDGAARD, JULIE; Sass, Louis A.; Parnas, Josef

    2012-01-01

    There is a glaring gap in the psychiatric literature concerning the nature of psychiatric symptoms and signs, and a corresponding lack of epistemological discussion of psycho-diagnostic interviewing. Contemporary clinical neuroscience heavily relies on the use of fully structured interviews that are historically rooted in logical positivism and behaviorism. These theoretical approaches marked decisively the so-called “operational revolution in psychiatry” leading to the creation of DSM-III. T...

  17. Combining Coarse-Grained Protein Models with Replica-Exchange All-Atom Molecular Dynamics

    OpenAIRE

    Andrzej Koliński; Maksim Kouza; Dominik Gront; Sebastian Kmiecik; Jacek Wabik

    2013-01-01

    We describe a combination of all-atom simulations with CABS, a well-established coarse-grained protein modeling tool, into a single multiscale protocol. The simulation method has been tested on the C-terminal beta hairpin of protein G, a model system of protein folding. After reconstructing atomistic details, conformations derived from the CABS simulation were subjected to replica-exchange molecular dynamics simulations with OPLS-AA and AMBER99sb force fields in explicit solvent. Such a combi...

  18. Explicit all-atom modeling of realistically sized ligand-capped nanocrystals

    KAUST Repository

    Kaushik, Ananth P.

    2012-01-01

    We present a study of an explicit all-atom representation of nanocrystals of experimentally relevant sizes (up to 6 nm), capped with alkyl chain ligands, in vacuum. We employ all-atom molecular dynamics simulation methods in concert with a well-tested intermolecular potential model, MM3 (molecular mechanics 3), for the studies presented here. These studies include determining the preferred conformation of an isolated single nanocrystal (NC), pairs of isolated NCs, and (presaging studies of superlattice arrays) unit cells of NC superlattices. We observe that very small NCs (3 nm) behave differently in a superlattice as compared to larger NCs (6 nm and above) due to the conformations adopted by the capping ligands on the NC surface. Short ligands adopt a uniform distribution of orientational preferences, including some that lie against the face of the nanocrystal. In contrast, longer ligands prefer to interdigitate. We also study the effect of changing ligand length and ligand coverage on the NCs on the preferred ligand configurations. Since explicit all-atom modeling constrains the maximum system size that can be studied, we discuss issues related to coarse-graining the representation of the ligands, including a comparison of two commonly used coarse-grained models. We find that care has to be exercised in the choice of coarse-grained model. The data provided by these realistically sized ligand-capped NCs, determined using explicit all-atom models, should serve as a reference standard for future models of coarse-graining ligands using united atom models, especially for self-assembly processes. © 2012 American Institute of Physics.

  19. Analysis and validation of carbohydrate three-dimensional structures

    International Nuclear Information System (INIS)

    The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described. Knowledge of the three-dimensional structures of the carbohydrate molecules is indispensable for a full understanding of the molecular processes in which carbohydrates are involved, such as protein glycosylation or protein–carbohydrate interactions. The Protein Data Bank (PDB) is a valuable resource for three-dimensional structural information on glycoproteins and protein–carbohydrate complexes. Unfortunately, many carbohydrate moieties in the PDB contain inconsistencies or errors. This article gives an overview of the information that can be obtained from individual PDB entries and from statistical analyses of sets of three-dimensional structures, of typical problems that arise during the analysis of carbohydrate three-dimensional structures and of the validation tools that are currently available to scientists to evaluate the quality of these structures

  20. Quantum Mechanics/Molecular Mechanics Method Combined with Hybrid All-Atom and Coarse-Grained Model: Theory and Application on Redox Potential Calculations.

    Science.gov (United States)

    Shen, Lin; Yang, Weitao

    2016-04-12

    We developed a new multiresolution method that spans three levels of resolution with quantum mechanical, atomistic molecular mechanical, and coarse-grained models. The resolution-adapted all-atom and coarse-grained water model, in which an all-atom structural description of the entire system is maintained during the simulations, is combined with the ab initio quantum mechanics and molecular mechanics method. We apply this model to calculate the redox potentials of the aqueous ruthenium and iron complexes by using the fractional number of electrons approach and thermodynamic integration simulations. The redox potentials are recovered in excellent accordance with the experimental data. The speed-up of the hybrid all-atom and coarse-grained water model renders it computationally more attractive. The accuracy depends on the hybrid all-atom and coarse-grained water model used in the combined quantum mechanical and molecular mechanical method. We have used another multiresolution model, in which an atomic-level layer of water molecules around redox center is solvated in supramolecular coarse-grained waters for the redox potential calculations. Compared with the experimental data, this alternative multilayer model leads to less accurate results when used with the coarse-grained polarizable MARTINI water or big multipole water model for the coarse-grained layer. PMID:26930454

  1. All-atom Molecular Dynamic Simulations and NMR Spectra Study on Intermolecular Interactions of N,N-dimethylacetamide-Water System

    Institute of Scientific and Technical Information of China (English)

    Rong Zhang; Zai-you Tan; San-lai Luo

    2008-01-01

    N,N-dimethylacetamide (DMA) has been investigated extensively in studying models of peptide bonds. An all-atom MD simulation and the NMR spectra were performed to investigate the interactions in the DMA- water system. The radial distribution functions (RDFs) and the hydrogen-bonding network were used in MD simulations. There are strong hydrogen bonds and weak C-H…O contacts in the mixtures, as shown by the analysis of the RDFs. The insight structures in the DMA-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Chemical shifts of the hydrogen atom of water molecule with concentration and temperatures are adopted to study the interactions in the mixtures. The results of NMR spectra show good agreement with the statistical results of hydrogen bonds in MD simulations.

  2. Molecular jamming - the cystine slipknot mechanical clamp in all-atom simulations

    OpenAIRE

    Peplowski, Lukasz; Sikora, Mateusz; Nowak, Wieslaw; Cieplak, Marek

    2011-01-01

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force-peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e. by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement w...

  3. Accelerating All-Atom Normal Mode Analysis with Graphics Processing Unit.

    Science.gov (United States)

    Liu, Li; Liu, Xiaofeng; Gong, Jiayu; Jiang, Hualiang; Li, Honglin

    2011-06-14

    All-atom normal mode analysis (NMA) is an efficient way to predict the collective motions in a given macromolecule, which is essential for the understanding of protein biological function and drug design. However, the calculations are limited in time scale mainly because the required diagonalization of the Hessian matrix by Householder-QR transformation is a computationally exhausting task. In this paper, we demonstrate the parallel computing power of the graphics processing unit (GPU) in NMA by mapping Householder-QR transformation onto GPU using Compute Unified Device Architecture (CUDA). The results revealed that the GPU-accelerated all-atom NMA could reduce the runtime of diagonalization significantly and achieved over 20× speedup over CPU-based NMA. In addition, we analyzed the influence of precision on both the performance and the accuracy of GPU. Although the performance of GPU with double precision is weaker than that with single precision in theory, more accurate results and an acceptable speedup of double precision were obtained in our approach by reducing the data transfer time to a minimum. Finally, the inherent drawbacks of GPU and the corresponding solution to deal with the limitation in computational scale are also discussed in this study. PMID:26596427

  4. Structural and Convergent Validity of the Homework Performance Questionnaire

    Science.gov (United States)

    Pendergast, Laura L.; Watkins, Marley W.; Canivez, Gary L.

    2014-01-01

    Homework is a requirement for most school-age children, but research on the benefits and drawbacks of homework is limited by lack of psychometrically sound measurement of homework performance. This study examined the structural and convergent validity of scores from the newly developed Homework Performance Questionnaire -- Teacher Scale (HPQ-T).…

  5. The Structure and Validity of the Multidimensional Social Support Questionnaire

    Science.gov (United States)

    Hardesty, Patrick H.; Richardson, George B.

    2012-01-01

    The factor structure and concurrent validity of the Multidimensional Social Support Questionnaire, a brief measure of perceived social support for use with adolescents, was examined. Findings suggest that four dimensions of perceived social support may yield more information than assessments of the unitary construct of support. (Contains 8 tables…

  6. Structural and Discriminant Validity of the Career Factors Inventory

    Science.gov (United States)

    Dickinson, Josephine; Tokar, David M.

    2004-01-01

    Using a sample of 350 college students, this study examined the structural and discriminant validity of the Career Factors Inventory (CFI; Chartrand, Robbins, Morrill, & Boggs, 1990), a multidimensional measure of career indecision intended to be scored for two informational indecision components (Need for Career Information and Need for…

  7. In-silico folding of a three helix protein and characterization of its free-energy landscape in an all-atom forcefield

    CERN Document Server

    Herges, T

    2003-01-01

    We report the reproducible first-principles folding of the 40 amino acid, three-helix headpiece of the HIV accessory protein in a recently developed all-atom free-energy forcefield. Six of twenty simulations using an adapted basin-hopping method converged to better than 3 \\AA backbone RMS deviation to the experimental structure. Using over 60,000 low-energy conformations of this protein, we constructed a decoy tree that completely characterizes its folding funnel.

  8. A-Site Residues Move Independently from P-Site Residues in all-Atom Molecular Dynamics Simulations of the 70S Bacterial Ribosome

    OpenAIRE

    Relly Brandman; Yigal Brandman; Pande, Vijay S.

    2012-01-01

    The ribosome is a large macromolecular machine, and correlated motion between residues is necessary for coordinating function across multiple protein and RNA chains. We ran two all-atom, explicit solvent molecular dynamics simulations of the bacterial ribosome and calculated correlated motion between residue pairs by using mutual information. Because of the short timescales of our simulation (ns), we expect that dynamics are largely local fluctuations around the crystal structure. We hypothes...

  9. The Chemical Validation and Standardization Platform (CVSP): large-scale automated validation of chemical structure datasets

    OpenAIRE

    Karapetyan, Karen; Batchelor, Colin; Sharpe, David; Tkachenko, Valery; Williams, Antony J

    2015-01-01

    Background There are presently hundreds of online databases hosting millions of chemical compounds and associated data. As a result of the number of cheminformatics software tools that can be used to produce the data, subtle differences between the various cheminformatics platforms, as well as the naivety of the software users, there are a myriad of issues that can exist with chemical structure representations online. In order to help facilitate validation and standardization of chemical stru...

  10. Picosecond infrared laser-induced all-atom nonequilibrium molecular dynamics simulation of dissociation of viruses.

    Science.gov (United States)

    Hoang Man, Viet; Van-Oanh, Nguyen-Thi; Derreumaux, Philippe; Li, Mai Suan; Roland, Christopher; Sagui, Celeste; Nguyen, Phuong H

    2016-04-28

    Since the discovery of the plant pathogen tobacco mosaic virus as the first viral entity in the late 1800s, viruses traditionally have been mainly thought of as pathogens for disease-resistances. However, viruses have recently been exploited as nanoplatforms with applications in biomedicine and materials science. To this aim, a large majority of current methods and tools have been developed to improve the physical stability of viral particles, which may be critical to the extreme physical or chemical conditions that viruses may encounter during purification, fabrication processes, storage and use. However, considerably fewer studies are devoted to developing efficient methods to degrade or recycle such enhanced stability biomaterials. With this in mind, we carry out all-atom nonequilibrium molecular dynamics simulation, inspired by the recently developed mid-infrared free-electron laser pulse technology, to dissociate viruses. Adopting the poliovirus as a representative example, we find that the primary step in the dissociation process is due to the strong resonance between the amide I vibrational modes of the virus and the tuned laser frequencies. This process is determined by a balance between the formation and dissociation of the protein shell, reflecting the highly plasticity of the virus. Furthermore, our method should provide a feasible approach to simulate viruses, which is otherwise too expensive for conventional equilibrium all-atom simulations of such very large systems. Our work shows a proof of concept which may open a new, efficient way to cleave or to recycle virus-based materials, provide an extremely valuable tool for elucidating mechanical aspects of viruses, and may well play an important role in future fighting against virus-related diseases. PMID:27071540

  11. Validation of the Dyadic Coping Inventory with Chinese couples: Factorial structure, measurement invariance, and construct validity.

    Science.gov (United States)

    Xu, Feng; Hilpert, Peter; Randall, Ashley K; Li, Qiuping; Bodenmann, Guy

    2016-08-01

    The Dyadic Coping Inventory (DCI, Bodenmann, 2008) assesses how couples support each other when facing individual (e.g., workload) and common (e.g., parenting) stressors. Specifically, the DCI measures partners' perceptions of their own (Self) and their partners' behaviors (Partner) when facing individual stressors, and partners' common coping behaviors when facing common stressors (Common). To date, the DCI has been validated in 6 different languages from individualistic Western cultures; however, because culture can affect interpersonal interactions, it is unknown whether the DCI is a reliable measure of coping behaviors for couples living in collectivistic Eastern cultures. Based on data from 474 Chinese couples (N = 948 individuals), the current study examined the Chinese version of the DCI's factorial structure, measurement invariance (MI), and construct validity of test scores. Using 3 cultural groups (China, Switzerland, and the United States [U.S.]), confirmatory factor analysis revealed a 5-factor structure regarding Self and Partner and a 2-factor structure regarding Common dyadic coping (DC). Results from analyses of MI indicated that the DCI subscales met the criteria for configural, metric, and full/partial scalar invariance across cultures (Chinese-Swiss and Chinese-U.S.) and genders (Chinese men and women). Results further revealed good construct validity of the DCI test scores. In all, the Chinese version of the DCI can be used for measuring Chinese couples' coping behaviors, and is available for cross-cultural studies examining DC behaviors between Western and Eastern cultures. (PsycINFO Database Record PMID:27183045

  12. Validation of the transient Structural Response of a Threaded Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Doebling, S. W. (Scott W.); Hemez, F. M. (François M.); Schultze, J. F. (John F.)

    2002-01-01

    This paper will demonstrate the application of model validation techniques to a transient structural dynamics problem. The problem of interest is the propagation of an explosive shock through a complex threaded joint that is a surrogate model of a system assembly. The objective is to validate the computational modeling of the key mechanical phenomena in the assembly, so that the component can be represented with adequate fidelity in the system-level model. A set of experiments was conducted on the threaded assembly where the acceleration and strain responses to an explosive load were measured on mass-simulators representing payloads. A significantly detailed computational model of the threaded assembly was also created. Numerical features that represent the important characteristics of the response were defined and calculated for both the experimental and computational data. Each step of the model validation process will be described as applied to this problem. Fundamental issues regarding the nature of model validation and the role of model validation in the engineering analysis process will also be discussed.

  13. Validation of Design and Analysis Techniques of Tailored Composite Structures

    Science.gov (United States)

    Jegley, Dawn C. (Technical Monitor); Wijayratne, Dulnath D.

    2004-01-01

    Aeroelasticity is the relationship between the elasticity of an aircraft structure and its aerodynamics. This relationship can cause instabilities such as flutter in a wing. Engineers have long studied aeroelasticity to ensure such instabilities do not become a problem within normal operating conditions. In recent decades structural tailoring has been used to take advantage of aeroelasticity. It is possible to tailor an aircraft structure to respond favorably to multiple different flight regimes such as takeoff, landing, cruise, 2-g pull up, etc. Structures can be designed so that these responses provide an aerodynamic advantage. This research investigates the ability to design and analyze tailored structures made from filamentary composites. Specifically the accuracy of tailored composite analysis must be verified if this design technique is to become feasible. To pursue this idea, a validation experiment has been performed on a small-scale filamentary composite wing box. The box is tailored such that its cover panels induce a global bend-twist coupling under an applied load. Two types of analysis were chosen for the experiment. The first is a closed form analysis based on a theoretical model of a single cell tailored box beam and the second is a finite element analysis. The predicted results are compared with the measured data to validate the analyses. The comparison of results show that the finite element analysis is capable of predicting displacements and strains to within 10% on the small-scale structure. The closed form code is consistently able to predict the wing box bending to 25% of the measured value. This error is expected due to simplifying assumptions in the closed form analysis. Differences between the closed form code representation and the wing box specimen caused large errors in the twist prediction. The closed form analysis prediction of twist has not been validated from this test.

  14. All-atom molecular dynamics calculation study of entire poliovirus empty capsids in solution

    Energy Technology Data Exchange (ETDEWEB)

    Andoh, Y.; Yoshii, N.; Yamada, A.; Kojima, H.; Mizutani, K.; Okazaki, S., E-mail: okazaki@apchem.nagoya-u.ac.jp [Department of Applied Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Fujimoto, K. [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Nakagawa, A. [Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871 (Japan); Nomoto, A. [Institute of Microbial Chemistry, Kamiosaki, Shinagawa-ku, Tokyo 141-0021 (Japan)

    2014-10-28

    Small viruses that belong, for example, to the Picornaviridae, such as poliovirus and foot-and-mouth disease virus, consist simply of capsid proteins and a single-stranded RNA (ssRNA) genome. The capsids are quite stable in solution to protect the genome from the environment. Here, based on long-time and large-scale 6.5 × 10{sup 6} all-atom molecular dynamics calculations for the Mahoney strain of poliovirus, we show microscopic properties of the viral capsids at a molecular level. First, we found equilibrium rapid exchange of water molecules across the capsid. The exchange rate is so high that all water molecules inside the capsid (about 200 000) can leave the capsid and be replaced by water molecules from the outside in about 25 μs. This explains the capsid's tolerance to high pressures and deactivation by exsiccation. In contrast, the capsid did not exchange ions, at least within the present simulation time of 200 ns. This implies that the capsid can function, in principle, as a semipermeable membrane. We also found that, similar to the xylem of trees, the pressure of the solution inside the capsid without the genome was negative. This is caused by coulombic interaction of the solution inside the capsid with the capsid excess charges. The negative pressure may be compensated by positive osmotic pressure by the solution-soluble ssRNA and the counter ions introduced into it.

  15. All-atom molecular dynamics calculation study of entire poliovirus empty capsids in solution

    International Nuclear Information System (INIS)

    Small viruses that belong, for example, to the Picornaviridae, such as poliovirus and foot-and-mouth disease virus, consist simply of capsid proteins and a single-stranded RNA (ssRNA) genome. The capsids are quite stable in solution to protect the genome from the environment. Here, based on long-time and large-scale 6.5 × 106 all-atom molecular dynamics calculations for the Mahoney strain of poliovirus, we show microscopic properties of the viral capsids at a molecular level. First, we found equilibrium rapid exchange of water molecules across the capsid. The exchange rate is so high that all water molecules inside the capsid (about 200 000) can leave the capsid and be replaced by water molecules from the outside in about 25 μs. This explains the capsid's tolerance to high pressures and deactivation by exsiccation. In contrast, the capsid did not exchange ions, at least within the present simulation time of 200 ns. This implies that the capsid can function, in principle, as a semipermeable membrane. We also found that, similar to the xylem of trees, the pressure of the solution inside the capsid without the genome was negative. This is caused by coulombic interaction of the solution inside the capsid with the capsid excess charges. The negative pressure may be compensated by positive osmotic pressure by the solution-soluble ssRNA and the counter ions introduced into it

  16. Preformed template fluctuations promote fibril formation: Insights from lattice and all-atom models

    Energy Technology Data Exchange (ETDEWEB)

    Kouza, Maksim, E-mail: mkouza@chem.uw.edu.pl; Kolinski, Andrzej [Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warszaw (Poland); Co, Nguyen Truong [Department of Physics, Institute of Technology, National University of HCM City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Institute for Computational Science and Technology, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City (Viet Nam); Nguyen, Phuong H. [Laboratoire de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Paris 7, 13 rue Pierre et Marie Curie, 75005 Paris (France); Li, Mai Suan, E-mail: masli@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2015-04-14

    Fibril formation resulting from protein misfolding and aggregation is a hallmark of several neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. Despite the fact that the fibril formation process is very slow and thus poses a significant challenge for theoretical and experimental studies, a number of alternative pictures of molecular mechanisms of amyloid fibril formation have been recently proposed. What seems to be common for the majority of the proposed models is that fibril elongation involves the formation of pre-nucleus seeds prior to the creation of a critical nucleus. Once the size of the pre-nucleus seed reaches the critical nucleus size, its thermal fluctuations are expected to be small and the resulting nucleus provides a template for sequential (one-by-one) accommodation of added monomers. The effect of template fluctuations on fibril formation rates has not been explored either experimentally or theoretically so far. In this paper, we make the first attempt at solving this problem by two sets of simulations. To mimic small template fluctuations, in one set, monomers of the preformed template are kept fixed, while in the other set they are allowed to fluctuate. The kinetics of addition of a new peptide onto the template is explored using all-atom simulations with explicit water and the GROMOS96 43a1 force field and simple lattice models. Our result demonstrates that preformed template fluctuations can modulate protein aggregation rates and pathways. The association of a nascent monomer with the template obeys the kinetics partitioning mechanism where the intermediate state occurs in a fraction of routes to the protofibril. It was shown that template immobility greatly increases the time of incorporating a new peptide into the preformed template compared to the fluctuating template case. This observation has also been confirmed by simulation using lattice models and may be invoked to understand the role of template fluctuations in

  17. Preformed template fluctuations promote fibril formation: Insights from lattice and all-atom models

    International Nuclear Information System (INIS)

    Fibril formation resulting from protein misfolding and aggregation is a hallmark of several neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. Despite the fact that the fibril formation process is very slow and thus poses a significant challenge for theoretical and experimental studies, a number of alternative pictures of molecular mechanisms of amyloid fibril formation have been recently proposed. What seems to be common for the majority of the proposed models is that fibril elongation involves the formation of pre-nucleus seeds prior to the creation of a critical nucleus. Once the size of the pre-nucleus seed reaches the critical nucleus size, its thermal fluctuations are expected to be small and the resulting nucleus provides a template for sequential (one-by-one) accommodation of added monomers. The effect of template fluctuations on fibril formation rates has not been explored either experimentally or theoretically so far. In this paper, we make the first attempt at solving this problem by two sets of simulations. To mimic small template fluctuations, in one set, monomers of the preformed template are kept fixed, while in the other set they are allowed to fluctuate. The kinetics of addition of a new peptide onto the template is explored using all-atom simulations with explicit water and the GROMOS96 43a1 force field and simple lattice models. Our result demonstrates that preformed template fluctuations can modulate protein aggregation rates and pathways. The association of a nascent monomer with the template obeys the kinetics partitioning mechanism where the intermediate state occurs in a fraction of routes to the protofibril. It was shown that template immobility greatly increases the time of incorporating a new peptide into the preformed template compared to the fluctuating template case. This observation has also been confirmed by simulation using lattice models and may be invoked to understand the role of template fluctuations in

  18. Predicting and validating protein interactions using network structure.

    Directory of Open Access Journals (Sweden)

    Pao-Yang Chen

    Full Text Available Protein interactions play a vital part in the function of a cell. As experimental techniques for detection and validation of protein interactions are time consuming, there is a need for computational methods for this task. Protein interactions appear to form a network with a relatively high degree of local clustering. In this paper we exploit this clustering by suggesting a score based on triplets of observed protein interactions. The score utilises both protein characteristics and network properties. Our score based on triplets is shown to complement existing techniques for predicting protein interactions, outperforming them on data sets which display a high degree of clustering. The predicted interactions score highly against test measures for accuracy. Compared to a similar score derived from pairwise interactions only, the triplet score displays higher sensitivity and specificity. By looking at specific examples, we show how an experimental set of interactions can be enriched and validated. As part of this work we also examine the effect of different prior databases upon the accuracy of prediction and find that the interactions from the same kingdom give better results than from across kingdoms, suggesting that there may be fundamental differences between the networks. These results all emphasize that network structure is important and helps in the accurate prediction of protein interactions. The protein interaction data set and the program used in our analysis, and a list of predictions and validations, are available at http://www.stats.ox.ac.uk/bioinfo/resources/PredictingInteractions.

  19. Probing the folded state and mechanical unfolding pathways of T4 lysozyme using all-atom and coarse-grained molecular simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wenjun, E-mail: wjzheng@buffalo.edu; Glenn, Paul [Department of Physics, University at Buffalo, Buffalo, New York 14260 (United States)

    2015-01-21

    The Bacteriophage T4 Lysozyme (T4L) is a prototype modular protein comprised of an N-terminal and a C-domain domain, which was extensively studied to understand the folding/unfolding mechanism of modular proteins. To offer detailed structural and dynamic insights to the folded-state stability and the mechanical unfolding behaviors of T4L, we have performed extensive equilibrium and steered molecular dynamics simulations of both the wild-type (WT) and a circular permutation (CP) variant of T4L using all-atom and coarse-grained force fields. Our all-atom and coarse-grained simulations of the folded state have consistently found greater stability of the C-domain than the N-domain in isolation, which is in agreement with past thermostatic studies of T4L. While the all-atom simulation cannot fully explain the mechanical unfolding behaviors of the WT and the CP variant observed in an optical tweezers study, the coarse-grained simulations based on the Go model or a modified elastic network model (mENM) are in qualitative agreement with the experimental finding of greater unfolding cooperativity in the WT than the CP variant. Interestingly, the two coarse-grained models predict different structural mechanisms for the observed change in cooperativity between the WT and the CP variant—while the Go model predicts minor modification of the unfolding pathways by circular permutation (i.e., preserving the general order that the N-domain unfolds before the C-domain), the mENM predicts a dramatic change in unfolding pathways (e.g., different order of N/C-domain unfolding in the WT and the CP variant). Based on our simulations, we have analyzed the limitations of and the key differences between these models and offered testable predictions for future experiments to resolve the structural mechanism for cooperative folding/unfolding of T4L.

  20. Probing the folded state and mechanical unfolding pathways of T4 lysozyme using all-atom and coarse-grained molecular simulation

    International Nuclear Information System (INIS)

    The Bacteriophage T4 Lysozyme (T4L) is a prototype modular protein comprised of an N-terminal and a C-domain domain, which was extensively studied to understand the folding/unfolding mechanism of modular proteins. To offer detailed structural and dynamic insights to the folded-state stability and the mechanical unfolding behaviors of T4L, we have performed extensive equilibrium and steered molecular dynamics simulations of both the wild-type (WT) and a circular permutation (CP) variant of T4L using all-atom and coarse-grained force fields. Our all-atom and coarse-grained simulations of the folded state have consistently found greater stability of the C-domain than the N-domain in isolation, which is in agreement with past thermostatic studies of T4L. While the all-atom simulation cannot fully explain the mechanical unfolding behaviors of the WT and the CP variant observed in an optical tweezers study, the coarse-grained simulations based on the Go model or a modified elastic network model (mENM) are in qualitative agreement with the experimental finding of greater unfolding cooperativity in the WT than the CP variant. Interestingly, the two coarse-grained models predict different structural mechanisms for the observed change in cooperativity between the WT and the CP variant—while the Go model predicts minor modification of the unfolding pathways by circular permutation (i.e., preserving the general order that the N-domain unfolds before the C-domain), the mENM predicts a dramatic change in unfolding pathways (e.g., different order of N/C-domain unfolding in the WT and the CP variant). Based on our simulations, we have analyzed the limitations of and the key differences between these models and offered testable predictions for future experiments to resolve the structural mechanism for cooperative folding/unfolding of T4L

  1. Membrane Binding and Insertion of a pHLIP Peptide Studied by All-Atom Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Guanghong Wei

    2013-07-01

    Full Text Available Recent experiments in function mechanism study reported that a pH low-insertion peptide (pHLIP can insert into a zwitterionic palmitoyloleoylphosphatidylcholine (POPC lipid bilayer at acidic pH while binding to the bilayer surface at basic pH. However, the atomic details of the pH-dependent interaction of pHLIP with a POPC bilayer are not well understood. In this study, we investigate the detailed interactions of pHLIP with a POPC bilayer at acidic and basic pH conditions as those used in function mechanism study, using all-atom molecular dynamics (MD simulations. Simulations have been performed by employing the initial configurations, where pHLIP is placed in aqueous solution, parallel to bilayer surface (system S, partially-inserted (system P, or fully-inserted (system F in POPC bilayers. On the basis of multiple 200-ns MD simulations, we found (1 pHLIP in system S can spontaneously insert into a POPC bilayer at acidic pH, while binding to the membrane surface at basic pH; (2 pHLIP in system P can insert deep into a POPC bilayer at acidic pH, while it has a tendency to exit, and stays at bilayer surface at basic pH; (3 pHLIP in system F keeps in an α-helical structure at acidic pH while partially unfolding at basic pH. This study provides at atomic-level the pH-induced insertion of pHLIP into POPC bilayer.

  2. Validating spatial structure in canopy water content using geostatistics

    Science.gov (United States)

    Sanderson, E. W.; Zhang, M. H.; Ustin, S. L.; Rejmankova, E.; Haxo, R. S.

    1995-01-01

    Heterogeneity in ecological phenomena are scale dependent and affect the hierarchical structure of image data. AVIRIS pixels average reflectance produced by complex absorption and scattering interactions between biogeochemical composition, canopy architecture, view and illumination angles, species distributions, and plant cover as well as other factors. These scales affect validation of pixel reflectance, typically performed by relating pixel spectra to ground measurements acquired at scales of 1m(exp 2) or less (e.g., field spectra, foilage and soil samples, etc.). As image analysis becomes more sophisticated, such as those for detection of canopy chemistry, better validation becomes a critical problem. This paper presents a methodology for bridging between point measurements and pixels using geostatistics. Geostatistics have been extensively used in geological or hydrogeolocial studies but have received little application in ecological studies. The key criteria for kriging estimation is that the phenomena varies in space and that an underlying controlling process produces spatial correlation between the measured data points. Ecological variation meets this requirement because communities vary along environmental gradients like soil moisture, nutrient availability, or topography.

  3. Comparison and validation of community structures in complex networks

    CERN Document Server

    Gustafsson, M; Lombardi, A; Gustafsson, Mika; Hornquist, Michael; Lombardi, Anna

    2006-01-01

    The issue of partitioning a network into communities has attracted a great deal of attention recently. Most authors seem to equate this issue with the one of finding the maximum value of the modularity, as defined by Newman. Since the problem formulated this way is NP-hard, most effort has gone into the construction of search algorithms, and less to the question of other measures of community structures, similarities between various partitionings and the validation with respect to external information. Here we concentrate on a class of computer generated networks and on three well-studied real networks which constitute a bench-mark for network studies; the karate club, the US college football teams and a gene network of yeast. We utilize some standard ways of clustering data (originally not designed for finding community structures in networks) and show that these classical methods sometimes outperform the newer ones. We discuss various measures of the strength of the modular structure, and show by examples f...

  4. Using of Structural Equation Modeling Techniques in Cognitive Levels Validation

    Directory of Open Access Journals (Sweden)

    Natalija Curkovic

    2012-10-01

    Full Text Available When constructing knowledge tests, cognitive level is usually one of the dimensions comprising the test specifications with each item assigned to measure a particular level. Recently used taxonomies of the cognitive levels most often represent some modification of the original Bloom’s taxonomy. There are many concerns in current literature about existence of predefined cognitive levels. The aim of this article is to investigate can structural equation modeling techniques confirm existence of different cognitive levels. For the purpose of the research, a Croatian final high-school Mathematics exam was used (N = 9626. Confirmatory factor analysis and structural regression modeling were used to test three different models. Structural equation modeling techniques did not support existence of different cognitive levels in this case. There is more than one possible explanation for that finding. Some other techniques that take into account nonlinear behaviour of the items as well as qualitative techniques might be more useful for the purpose of the cognitive levels validation. Furthermore, it seems that cognitive levels were not efficient descriptors of the items and so improvements are needed in describing the cognitive skills measured by items.

  5. Factor structure, reliability, and validity of the Therapist Response Questionnaire.

    Science.gov (United States)

    Tanzilli, Annalisa; Colli, Antonello; Del Corno, Franco; Lingiardi, Vittorio

    2016-04-01

    The aim of this study was to examine the stability of the factor structure and psychometric properties of the Therapist Response Questionnaire (Betan, Heim, Zittel Conklin, & Westen, 2005; Zittel Conklin & Westen, 2003), a clinician report instrument able to measure the clinician's emotional reactions to the patient in psychotherapy. A national sample of psychiatrists and clinical psychologists (N = 332) of psychodynamic and cognitive-behavioral orientation completed the Therapist Response Questionnaire, as well as the Shedler-Westen Assessment Procedure-200 (Westen & Shedler, 1999a, 1999b), to assess personality disorders and level of psychological functioning, regarding a patient currently in their care. They also administered the Symptom Checklist-90-Revised (Derogatis, 1994) to the patients. Exploratory and confirmatory factor analyses revealed 9 distinct countertransference factors that were similar to 8 dimensions identified in the original version of the measure: (a) helpless/inadequate, (b) overwhelmed/disorganized, (c) positive/satisfying, (d) hostile/angry, (e) criticized/devalued, (f) parental/protective, (g) special/overinvolved, (h) sexualized, and (i) disengaged. These scales showed excellent internal consistencies and good validity. They were especially able to capture the quality and intensity of emotional states that therapists experience while treating personality-disordered patients, as well as to better differentiate them; additionally, they tapped into the complexity of clinicians' reactions toward patients experiencing severe psychiatric symptomatology. Results seem to confirm that Therapist Response Questionnaire is a valid and reliable instrument that allows to evaluate patterns of countertransference responses in clinically sensitive and psychometrically robust ways, regardless of therapists' orientations. The clinical and research implications of these findings are addressed. (PsycINFO Database Record PMID:26389623

  6. The Role of Structural Models in the Solar Sail Flight Validation Process

    Science.gov (United States)

    Johnston, John D.

    2004-01-01

    NASA is currently soliciting proposals via the New Millennium Program ST-9 opportunity for a potential Solar Sail Flight Validation (SSFV) experiment to develop and operate in space a deployable solar sail that can be steered and provides measurable acceleration. The approach planned for this experiment is to test and validate models and processes for solar sail design, fabrication, deployment, and flight. These models and processes would then be used to design, fabricate, and operate scaleable solar sails for future space science missions. There are six validation objectives planned for the ST9 SSFV experiment: 1) Validate solar sail design tools and fabrication methods; 2) Validate controlled deployment; 3) Validate in space structural characteristics (focus of poster); 4) Validate solar sail attitude control; 5) Validate solar sail thrust performance; 6) Characterize the sail's electromagnetic interaction with the space environment. This poster presents a top-level assessment of the role of structural models in the validation process for in-space structural characteristics.

  7. Molecular insights into diphenylalanine nanotube assembly: all-atom simulations of oligomerization.

    Science.gov (United States)

    Jeon, Joohyun; Mills, Carolyn E; Shell, M Scott

    2013-04-18

    Self-assembling peptides represent a growing class of inexpensive, environmentally benign, nanostructured materials. In particular, diphenylalanine (FF) self-assembles into nanotubes with remarkable strength and thermal stability that have found use in a wide variety of applications, including as sacrificial templates and scaffolds for structuring inorganic materials and as interfacial "nanoforests" for superhydrophobic surfaces and high-performance supercapacitors and biosensors. However, little is known about the assembly mechanisms of FF nanotubes or the forces underlying their stability. Here, we perform a variety of molecular dynamics simulations on both zwitterionic and capped (uncharged) versions of the FF peptide to understand the early stages of self-assembly. We compare these results to simulations of the proposed nanotube X-ray crystal structure. When comparing the zwitterionic and uncharged FF peptides, we find that, while electrostatic interactions steer the former into more ordered dimers and trimers, the hydrophobic side chain interactions play a strong role in determining the structures of larger oligomers. Simulations of the crystal structure fragment also suggest that the strongest interactions occur between side chains, not between the charged termini that form salt bridges. We conclude that the amphiphilic nature of FF is key to understanding its self-assembly, and that the early precursors to nanotube structures are likely to involve substantial hydrophobic clustering, rather than hexamer ring motifs as has been previously suggested. PMID:23521630

  8. Experimental validation of optimization-based integrated controls-structures design methodology for flexible space structures

    Science.gov (United States)

    Maghami, Peiman G.; Gupta, Sandeep; Joshi, Suresh M.; Walz, Joseph E.

    1993-01-01

    An optimization-based integrated design approach for flexible space structures is experimentally validated using three types of dissipative controllers, including static, dynamic, and LQG dissipative controllers. The nominal phase-0 of the controls structure interaction evolutional model (CEM) structure is redesigned to minimize the average control power required to maintain specified root-mean-square line-of-sight pointing error under persistent disturbances. The redesign structure, phase-1 CEM, was assembled and tested against phase-0 CEM. It is analytically and experimentally demonstrated that integrated controls-structures design is substantially superior to that obtained through the traditional sequential approach. The capability of a software design tool based on an automated design procedure in a unified environment for structural and control designs is demonstrated.

  9. Hierarchical atom type definitions and extensible all-atom force fields.

    Science.gov (United States)

    Jin, Zhao; Yang, Chunwei; Cao, Fenglei; Li, Feng; Jing, Zhifeng; Chen, Long; Shen, Zhe; Xin, Liang; Tong, Sijia; Sun, Huai

    2016-03-15

    The extensibility of force field is a key to solve the missing parameter problem commonly found in force field applications. The extensibility of conventional force fields is traditionally managed in the parameterization procedure, which becomes impractical as the coverage of the force field increases above a threshold. A hierarchical atom-type definition (HAD) scheme is proposed to make extensible atom type definitions, which ensures that the force field developed based on the definitions are extensible. To demonstrate how HAD works and to prepare a foundation for future developments, two general force fields based on AMBER and DFF functional forms are parameterized for common organic molecules. The force field parameters are derived from the same set of quantum mechanical data and experimental liquid data using an automated parameterization tool, and validated by calculating molecular and liquid properties. The hydration free energies are calculated successfully by introducing a polarization scaling factor to the dispersion term between the solvent and solute molecules. © 2015 Wiley Periodicals, Inc. PMID:26537332

  10. Effects of Lipid Composition on Bilayer Membranes Quantified by All-Atom Molecular Dynamics.

    Science.gov (United States)

    Ding, Wei; Palaiokostas, Michail; Wang, Wen; Orsi, Mario

    2015-12-10

    Biological bilayer membranes typically contain varying amounts of lamellar and nonlamellar lipids. Lamellar lipids, such as dioleoylphosphatidylcholine (DOPC), are defined by their tendency to form the lamellar phase, ubiquitous in biology. Nonlamellar lipids, such as dioleoylphosphatidylethanolamine (DOPE), prefer instead to form nonlamellar phases, which are mostly nonbiological. However, nonlamellar lipids mix with lamellar lipids in biomembrane structures that remain overall lamellar. Importantly, changes in the lamellar vs nonlamellar lipid composition are believed to affect membrane function and modulate membrane proteins. In this work, we employ atomistic molecular dynamics simulations to quantify how a range of bilayer properties are altered by variations in the lamellar vs nonlamellar lipid composition. Specifically, we simulate five DOPC/DOPE bilayers at mixing ratios of 1/0, 3/1, 1/1, 1/3, and 0/1. We examine properties including lipid area and bilayer thickness, as well as the transmembrane profiles of electron density, lateral pressure, electric field, and dipole potential. While the bilayer structure is only marginally altered by lipid composition changes, dramatic effects are observed for the lateral pressure, electric field, and dipole potential profiles. Possible implications for membrane function are discussed. PMID:26560961

  11. Application of principal component analysis in protein unfolding: An all-atom molecular dynamics simulation study

    Science.gov (United States)

    Das, Atanu; Mukhopadhyay, Chaitali

    2007-10-01

    We have performed molecular dynamics (MD) simulation of the thermal denaturation of one protein and one peptide—ubiquitin and melittin. To identify the correlation in dynamics among various secondary structural fragments and also the individual contribution of different residues towards thermal unfolding, principal component analysis method was applied in order to give a new insight to protein dynamics by analyzing the contribution of coefficients of principal components. The cross-correlation matrix obtained from MD simulation trajectory provided important information regarding the anisotropy of backbone dynamics that leads to unfolding. Unfolding of ubiquitin was found to be a three-state process, while that of melittin, though smaller and mostly helical, is more complicated.

  12. Reparameterization of all-atom dipalmitoylphosphatidylcholine lipid parameters enables simulation of fluid bilayers at zero tension

    DEFF Research Database (Denmark)

    Sonne, Jacob; Jensen, Morten Ø.; Hansen, Flemming Y.; Hemmingsen, Lars Bo Stegeager; Peters, Günther H.

    2007-01-01

    Molecular dynamics (MD) simulations of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers using the CHARMM27 force field in the tensionless isothermal-isobaric (N PT) ensemble give highly ordered, gel-like bilayers (20) with an area per lipid of ~48 Å2 (31). To obtain fluid (L ) phase properties...... of DPPC bilayers represented by the CHARMM energy function in this ensemble, we reparameterized the atomic partial charges in the lipid head group and upper parts of the acyl chains. The new charges were determined from the electron structure using both the Mulliken method and the restricted...... electrostatic potential (RESP) fitting method (5). We tested the derived charges in MD simulations of a fully hydrated DPPC bilayer. Only the simulation with the new RESP charges shows significant improvements compared with simulations using the original CHARMM27 force field resulting in an area per lipid of 60...

  13. Reparameterization of all-atom dipalmitoylphosphatidylcholine lipid parameters enables simulation of fluid bilayers at zero tension

    DEFF Research Database (Denmark)

    Sonne, Jacob; Jensen, M.Ø.; Hansen, Flemming Yssing; Hemmingsen, L.; Peters, Günther H.j.

    2007-01-01

    lipid of 60.4 ± 0.1 Å2. Compared to the 48 Å2, the new value of 60.4 Å2 is in fair agreement with the experimental value of 64 Å2. In addition, the simulated order parameter profile and electron density profile are in satisfactory agreement with experimental data. Thus, the biologically more interesting......Molecular dynamics simulations of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers using the CHARMM27 force field in the tensionless isothermal-isobaric (NPT) ensemble give highly ordered, gel-like bilayers with an area per lipid of ∼48 Å2. To obtain fluid (Lα) phase properties of DPPC bilayers...... represented by the CHARMM energy function in this ensemble, we reparameterized the atomic partial charges in the lipid headgroup and upper parts of the acyl chains. The new charges were determined from the electron structure using both the Mulliken method and the restricted electrostatic potential fitting...

  14. Nanosystem Self-Assembly Pathways Discovered via All-Atom Multiscale Analysis

    CERN Document Server

    Pankavich, Stephen

    2014-01-01

    We consider the self-assembly of composite structures from a group of nanocomponents, each consisting of particles within an $N$-atom system. Self-assembly pathways and rates for nanocomposites are derived via a multiscale analysis of the classical Liouville equation. From a reduced statistical framework, rigorous stochastic equations for population levels of beginning, intermediate, and final aggregates are also derived. It is shown that the definition of an assembly type is a self-consistency criterion that must strike a balance between precision and the need for population levels to be slowly varying relative to the time scale of atomic motion. The deductive multiscale approach is complemented by a qualitative notion of multicomponent association and the ensemble of exact atomic-level configurations consistent with them. In processes such as viral self-assembly from proteins and RNA or DNA, there are many possible intermediates, so that it is usually difficult to predict the most efficient assembly pathway...

  15. A Validation Study of the Dutch Childhood Trauma Questionnaire-Short Form: Factor Structure, Reliability, and Known-Groups Validity

    Science.gov (United States)

    Thombs, Brett D.; Bernstein, David P.; Lobbestael, Jill; Arntz, Arnoud

    2009-01-01

    Objective: The 28-item Childhood Trauma Questionnaire-Short Form (CTQ-SF) has been translated into at least 10 different languages. The validity of translated versions of the CTQ-SF, however, has generally not been examined. The objective of this study was to investigate the factor structure, internal consistency reliability, and known-groups…

  16. The Trait Emotional Intelligence Questionnaire: Internal Structure, Convergent, Criterion, and Incremental Validity in an Italian Sample

    Science.gov (United States)

    Andrei, Federica; Smith, Martin M.; Surcinelli, Paola; Baldaro, Bruno; Saklofske, Donald H.

    2016-01-01

    This study investigated the structure and validity of the Italian translation of the Trait Emotional Intelligence Questionnaire. Data were self-reported from 227 participants. Confirmatory factor analysis supported the four-factor structure of the scale. Hierarchical regressions also demonstrated its incremental validity beyond demographics, the…

  17. All-atom simulation study of protein PTH(1-34) by using the Wang-Landau sampling method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung-Yeon [Korea National University of Transportation, Chungju (Korea, Republic of); Kwak, Woo-Seop [Chosun University, Gwangju (Korea, Republic of)

    2014-12-15

    We perform simulations of the N-terminal 34-residue protein fragment PTH(1-34), consisting of 581 atoms, of the 84-residue human parathyroid hormone by using the all-atom ECEPP/3 force field and the Wang-Landau sampling method. Through a massive high-performance computation, the density of states and the partition function Z(T), as a continuous function of T, are obtained for PTH(1-34). From the continuous partition function Z(T), the partition function zeros of PTH(1-34) are evaluated for the first time. From both the specific heat and the partition function zeros, two characteristic transition temperatures are obtained for the all-atom protein PTH(1-34). The higher transition temperature T{sub 1} and the lower transition temperature T{sub 2} of PTH(1-34) can be interpreted as the collapse temperature T{sub θ} and the folding temperature T{sub f} , respectively.

  18. All-atom normal-mode analysis reveals an RNA-induced allostery in a bacteriophage coat protein

    Science.gov (United States)

    Dykeman, Eric C.; Twarock, Reidun

    2010-03-01

    Assembly of the T=3 bacteriophage MS2 is initiated by the binding of a 19 nucleotide RNA stem loop from within the phage genome to a symmetric coat protein dimer. This binding event effects a folding of the FG loop in one of the protein subunits of the dimer and results in the formation of an asymmetric dimer. Since both the symmetric and asymmetric forms of the dimer are needed for the assembly of the protein container, this allosteric switch plays an important role in the life cycle of the phage. We provide here details of an all-atom normal-mode analysis of this allosteric effect. The results suggest that asymmetric contacts between the A -duplex RNA phosphodiester backbone of the stem loop with the EF loop in one coat protein subunit results in an increased dynamic behavior of its FG loop. The four lowest-frequency modes, which encompass motions predominantly on the FG loops, account for over 90% of the increased dynamic behavior due to a localization of the vibrational pattern on a single FG loop. Finally, we show that an analysis of the allosteric effect using an elastic network model fails to predict this localization effect, highlighting the importance of using an all-atom full force field method for this problem.

  19. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): Time-resolved fluorescence measurements and all-atom molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Das, Anuradha; Das, Suman; Biswas, Ranjit, E-mail: ranjit@bose.res.in [Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata, West Bengal 700098 (India)

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH{sub 3}CONH{sub 2}) and urea (NH{sub 2}CONH{sub 2}) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH{sub 3}CONH{sub 2} + (1 − f)NH{sub 2}CONH{sub 2}] have been studied in a temperature range of 328-353 K which is ∼120-145 K above the measured glass transition temperatures (∼207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (∼70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α{sub 2}) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  20. Experimental validation of efficient impact simulation methodologies of sandwich structures

    OpenAIRE

    Kärger, Luise; Baaran, Jens; Teßmer, Jan

    2007-01-01

    Aircraft design calls for weight efficient shell constructions. Composite sandwich structures satisfy this demand by the combination of two thin, stiff face sheets and an intermediate lightweight core. Furthermore, the outer face sheet can act as an impact detector while the core provides damping and insulation. Thus, sandwich structures are increasingly aspired for application as fuselage and wing panels. However, impact damage in sandwich structures can provoke a significant strength and st...

  1. Experimentally validated finite element model of electrocaloric multilayer ceramic structures

    International Nuclear Information System (INIS)

    A novel finite element model to simulate the electrocaloric response of a multilayer ceramic capacitor (MLCC) under real environment and operational conditions has been developed. The two-dimensional transient conductive heat transfer model presented includes the electrocaloric effect as a source term, as well as accounting for radiative and convective effects. The model has been validated with experimental data obtained from the direct imaging of MLCC transient temperature variation under application of an electric field. The good agreement between simulated and experimental data, suggests that the novel experimental direct measurement methodology and the finite element model could be used to support the design of optimised electrocaloric units and operating conditions.

  2. Description and validation of realistic and structured endourology training model

    OpenAIRE

    Soria, Federico; Morcillo, Esther; Sanz, Juan Luis; Budia, Alberto; Serrano, Alvaro; Sanchez-Margallo, Francisco M

    2014-01-01

    Purpose: The aim of the present study was to validate a model of training, which combines the use of non-biological and ex vivo biological bench models, as well as the modelling of urological injuries for endourological treatment in a porcine animal model. Material and Methods: A total of 40 participants took part in this study. The duration of the activity was 16 hours. The model of training was divided into 3 levels: level I, concerning the acquisition of basic theoretical knowledge; level ...

  3. Validity and Reliability of pre-internship Objective Structured Clinical Examination in Shiraz Medical School

    OpenAIRE

    NARGES VASEGHI; MAHVASH ALIZADEH NAINI; REZA LABAF GHASEMI; SOHEILA AMIRI

    2013-01-01

    Introduction: Objective Structured Clinical Examination (OSCE) is one of the most appropriate methods for assessment of clinical skills.Validity and reliability assurance is a mandatory factor for any assessment tool. In Shiraz University of Medical Sciences, medical students’ clinical competences are evaluated by a pre-internship OSCE. This study is designed to examine the validity and reliability of this exam. Validity is the extent to which the test measures what it inten...

  4. A Validation of the French Version of the Attitudes to Aging Questionnaire (AAQ: Factor Structure, Reliability and Validity

    Directory of Open Access Journals (Sweden)

    Manon Marquet

    2016-03-01

    Full Text Available Introduction: The Attitudes to Aging Questionnaire (AAQ was developed to measure attitudes toward the aging process as a personal experience from the perspective of older people. The present study aimed to validate the French version of the AAQ. Participants and methods: This study examined factor structure, acceptability, reliability and validity of the AAQ’s French version in 238 Belgian adults aged 60 years or older. In addition, participants provided information on demographics, self-perception of their mental and physical health (single items, quality of life (WHOQOL-OLD and social desirability (DS-36.  Results: Exploratory Factor Analysis produced a three-factor solution accounting for 36.9% of the variance. No floor or ceiling effects were found. The internal consistency, measured by Cronbach’s alpha coefficients for the AAQ subscales were 0.62 (Physical Change, 0.74 (Psychological Growth, and 0.75 (Psychosocial Loss. A priori expected associations were found between AAQ subscales, self-reported health and quality of life, indicating good convergent validity. The scale also showed a good ability to discriminate between people with lower and higher education levels, supporting adequate known-groups validity. Finally, we confirmed the need to control for social desirability biases when assessing self-reported attitudes toward one’s own aging. Conclusion: The data support the usefulness of the French version of the AAQ for the assessment of attitudes toward their own aging in older people.

  5. Factor Structure, Validity and Reliability of the Revised Version of Skin Picking Scale

    OpenAIRE

    Mehdi Rabiei; Mehrdad Kalantari; Kariem Asgari; Fatemeh Bahrami

    2014-01-01

    Background: The purpose of this study was to examine the factor structure, validity and reliability of the Skin Picking Scale-Revised Version. Materials and Methods: In this descriptive and validation study, participants were 550 (250 male and 300 female) of the University of Isfahan were selected randomly from 15000 students. In order to examine the factor structure of the SPS-R we conducted both exploratory and confirmatory factor analyses and Cronbach's alpha. Results: Convergent val...

  6. Diagnosis and sensor validation through knowledge of structure and function

    Science.gov (United States)

    Scarl, Ethan A.; Jamieson, John R.; Delaune, Carl I.

    1987-01-01

    The liquid oxygen expert system 'LES' is proposed as the first capable of diagnostic reasoning from sensor data, using model-based knowledge of structure and function to find the expected state of all system objects, including sensors. The approach is generally algorithmic rather than heuristic, and represents uncertainties as sets of possibilities. Functional relationships are inverted to determine hypothetical values for potentially faulty objects, and may include conditional functions not normally considered to have inverses.

  7. Latent structure and construct validity of the reinforcement sensitivity questionnaire

    Directory of Open Access Journals (Sweden)

    Mitrović Dušanka

    2008-01-01

    Full Text Available The Revised reinforcement sensitivity theory contains three basic systems: Behavioral inhibition system (BAS, Behavioral activation system (BIS and the Fight/ Flight/ Freeze (FFF system. In this model, BIS is a system for detection of potential conflict or threat, and FFFS differs three basic patterns of reaction to actual or perceived danger. In Study 1, which was aimed at the examination of the latent structure of the RSQ, was conducted on a sample of 472 participants of both genders. The best - fitting model suggests that, at the top level of hierarchy, three dimensions exist, which are analogous to the BIS, BAS and FFF. The last dimension contains three subordinate dimensions, which represent the subsystems of the FFF. Study 2, in which 203 subjects participated, was aimed at examination of the relations between the dimensions of the Revised reinforcement sensitivity theory and dimensions of the PEN model. Confirmatory factor analyses of the RSQ and EPQ-R dimensions revealed that the best-fitting model comprised three latent dimensions, the first one being analogous to the BIS - Neuroticism, the second one to the BAS - Extraversion, and the third to the Aggressiveness- Psychoticism. The structure of the latent dimensions is in accordance with the expectations. The results state that fear and anxiety (which neurophysiological distinction is emphasized by Gray, are substantively similar on the behavioral level. Also, the results suggest that the Freeze dimension is probably closer to the BIS system than to the FFF.

  8. Structuring and validating a cost-effectiveness model of primary asthma prevention amongst children

    Directory of Open Access Journals (Sweden)

    Ramos G Feljandro P

    2011-11-01

    Full Text Available Abstract Background Given the rising number of asthma cases and the increasing costs of health care, prevention may be the best cure. Decisions regarding the implementation of prevention programmes in general and choosing between unifaceted and multifaceted strategies in particular are urgently needed. Existing trials on the primary prevention of asthma are, however, insufficient on their own to inform the decision of stakeholders regarding the cost-effectiveness of such prevention strategies. Decision analytic modelling synthesises available data for the cost-effectiveness evaluation of strategies in an explicit manner. Published reports on model development should provide the detail and transparency required to increase the acceptability of cost-effectiveness modelling. But, detail on the explicit steps and the involvement of experts in structuring a model is often unevenly reported. In this paper, we describe a procedure to structure and validate a model for the primary prevention of asthma in children. Methods An expert panel was convened for round-table discussions to frame the cost-effectiveness research question and to select and structure a model. The model's structural validity, which indicates how well a model reflects the reality, was determined through descriptive and parallel validation. Descriptive validation was performed with the experts. Parallel validation qualitatively compared similarity between other published models with different decision problems. Results The multidisciplinary input of experts helped to develop a decision-tree structure which compares the current situation with screening and prevention. The prevention was further divided between multifaceted and unifaceted approaches to analyse the differences. The clinical outcome was diagnosis of asthma. No similar model was found in the literature discussing the same decision problem. Structural validity in terms of descriptive validity was achieved with the experts

  9. Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations

    International Nuclear Information System (INIS)

    The accuracy of a dispersion-corrected density functional theory method is validated against 241 experimental organic crystal structures from Acta Cryst. Section E. This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 Å either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect

  10. All-atom force field for the prediction of vapor-liquid equilibria and interfacial properties of HFA134a.

    Science.gov (United States)

    Peguin, Robson P S; Kamath, Ganesh; Potoff, Jeffrey J; da Rocha, Sandro R P

    2009-01-01

    A new all-atom force field capable of accurately predicting the bulk and interfacial properties of 1,1,1,2-tetrafluoroethane (HFA134a) is reported. Parameterization of several force fields with different initial charge configurations from ab initio calculations was performed using the histogram reweighting method and Monte Carlo simulations in the grand canonical ensemble. The 12-6 Lennard-Jones well depth and diameter for the different HFA134a models were determined by fitting the simulation results to pure-component vapor-equilibrium data. Initial screening of the force fields was achieved by comparing the calculated and experimental bulk properties. The surface tension of pure HFA134a served as an additional screening property to help discriminate an optimum model. The proposed model reproduces the experimental saturated liquid and vapor densities, and the vapor pressure for HFA134a within average errors of 0.7%, 4.4%, and 3.1%, respectively. Critical density, temperature, vapor pressure, normal boiling point, and heat of vaporization at 298 K are also in good agreement with experimental data with errors of 0.2%, 0.1%, 6.2%, 0%, 2.2%, respectively. The calculated surface tension is found to be within the experimental range of 7.7-8.1 mN.m(-1). The dipole moment of the different models was found to significantly affect the prediction of the vapor pressure and surface tension. The ability of the HFA134a models in predicting the interfacial tension against water is also discussed. The results presented here are relevant in the development of technologies where the more environmentally friendly HFA134a is utilized as a substitute to the ozone depleting chlorofluorocarbon propellants. PMID:19086791

  11. Objective Structured Clinical Examinations Provide Valid Clinical Skills Assessment in Emergency Medicine Education

    OpenAIRE

    Wallenstein, Joshua; Ander, Douglas

    2015-01-01

    Introduction: Evaluation of emergency medicine (EM) learners based on observed performance in the emergency department (ED) is limited by factors such as reproducibility and patient safety. EM educators depend on standardized and reproducible assessments such as the objective structured clinical examination (OSCE). The validity of the OSCE as an evaluation tool in EM education has not been previously studied. The objective was to assess the validity of a novel management-focused OSCE as an ev...

  12. SNPs in stress-responsive rice genes: validation, genotyping, functional relevance and population structure

    OpenAIRE

    Parida Swarup K; Mukerji Mitali; Singh Ashok K; Singh Nagendra K; Mohapatra Trilochan

    2012-01-01

    Abstract Background Single nucleotide polymorphism (SNP) validation and large-scale genotyping are required to maximize the use of DNA sequence variation and determine the functional relevance of candidate genes for complex stress tolerance traits through genetic association in rice. We used the bead array platform-based Illumina GoldenGate assay to validate and genotype SNPs in a select set of stress-responsive genes to understand their functional relevance and study the population structure...

  13. Free energetics of carbon nanotube association in aqueous inorganic NaI salt solutions: Temperature effects using all-atom molecular dynamics simulations.

    Science.gov (United States)

    Ou, Shu-Ching; Cui, Di; Wezowicz, Matthew; Taufer, Michela; Patel, Sandeep

    2015-06-15

    In this study, we examine the temperature dependence of free energetics of nanotube association using graphical processing unit-enabled all-atom molecular dynamics simulations (FEN ZI) with two (10,10) single-walled carbon nanotubes in 3 m NaI aqueous salt solution. Results suggest that the free energy, enthalpy and entropy changes for the association process are all reduced at the high temperature, in agreement with previous investigations using other hydrophobes. Via the decomposition of free energy into individual components, we found that solvent contribution (including water, anion, and cation contributions) is correlated with the spatial distribution of the corresponding species and is influenced distinctly by the temperature. We studied the spatial distribution and the structure of the solvent in different regions: intertube, intratube and the bulk solvent. By calculating the fluctuation of coarse-grained tube-solvent surfaces, we found that tube-water interfacial fluctuation exhibits the strongest temperature dependence. By taking ions to be a solvent-like medium in the absence of water, tube-anion interfacial fluctuation shows similar but weaker dependence on temperature, while tube-cation interfacial fluctuation shows no dependence in general. These characteristics are discussed via the malleability of their corresponding solvation shells relative to the nanotube surface. Hydrogen bonding profiles and tetrahedrality of water arrangement are also computed to compare the structure of solvent in the solvent bulk and intertube region. The hydrophobic confinement induces a relatively lower concentration environment in the intertube region, therefore causing different intertube solvent structures which depend on the tube separation. This study is relevant in the continuing discourse on hydrophobic interactions (as they impact generally a broad class of phenomena in biology, biochemistry, and materials science and soft condensed matter research), and

  14. Validity and Reliability of pre-internship Objective Structured Clinical Examination in Shiraz Medical School

    Directory of Open Access Journals (Sweden)

    NARGES VASEGHI

    2013-07-01

    Full Text Available Introduction: Objective Structured Clinical Examination (OSCE is one of the most appropriate methods for assessment of clinical skills.Validity and reliability assurance is a mandatory factor for any assessment tool. In Shiraz University of Medical Sciences, medical students’ clinical competences are evaluated by a pre-internship OSCE. This study is designed to examine the validity and reliability of this exam. Validity is the extent to which the test measures what it intends to measure. Reliability refers to the accuracy of measurement and the consistency of test results. Methods: Content validity was evaluated by expert opinion about blueprinting and station checklists. To determine the construct validity, station scores correlation with the total OSCE score and inter station correlations were calculated. The inter examiner reliability was assessed by coefficient of correlation. Results: Content validity was established by alignment between the curriculum and the blueprint using expert opinion. Correlation of the station scores with the total OSCE score were positive and statistically significant in all stations except the 16th station (suturing. Inter examiner reliability coefficients of correlations ranged 0.33 – 0.99, with an average of 0.83. Conclusions: Our findings support the assumption that the pre-internship OSCE is valid, reliable and suitable to assess students’ clinical competence. Validity and reliability studies should be performed for all new assessment tools, particularly in high-stakes assessments.

  15. The Dynamic Similitude Design Method of Thin Walled Structures and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Zhong Luo

    2016-01-01

    Full Text Available For the applicability of dynamic similitude models of thin walled structures, such as engine blades, turbine discs, and cylindrical shells, the dynamic similitude design of typical thin walled structures is investigated. The governing equation of typical thin walled structures is firstly unified, which guides to establishing dynamic scaling laws of typical thin walled structures. Based on the governing equation, geometrically complete scaling law of the typical thin walled structure is derived. In order to determine accurate distorted scaling laws of typical thin walled structures, three principles are proposed and theoretically proved by combining the sensitivity analysis and governing equation. Taking the thin walled annular plate as an example, geometrically complete and distorted scaling laws can be obtained based on the principles of determining dynamic scaling laws. Furthermore, the previous five orders’ accurate distorted scaling laws of thin walled annular plates are presented and numerically validated. Finally, the effectiveness of the similitude design method is validated by experimental annular plates.

  16. A new criterion for assessing discriminant validity in variance-based structural equation modeling

    NARCIS (Netherlands)

    Henseler, J.; Ringle, Christian M.; Sarstedt, Marko

    2015-01-01

    Discriminant validity assessment has become a generally accepted prerequisite for analyzing relationships between latent variables. For variance-based structural equation modeling, such as partial least squares, the Fornell-Larcker criterion and the examination of cross-loadings are the dominant app

  17. Assessing the diagnostic validity of a structured psychiatric interview in a first-admission hospital sample

    OpenAIRE

    NORDGAARD, JULIE; REVSBECH, RASMUS; Sæbye, Ditte; Parnas, Josef

    2012-01-01

    The use of structured psychiatric interviews performed by non-clinicians is frequent for research purposes and is becoming increasingly common in clini-cal practice. The validity of such interviews has rarely been evaluated empirically. In this study of a sample of 100 diagnostically heterogeneous, first-admitted inpatients, the results of an assessment with the Structured Clinical Interview for DSM-IV (SCID), yielding a DSM-IV diagnosis and performed by a trained non-clinic...

  18. The structure-based expert model of the mental disorders - a validation study

    OpenAIRE

    Egli, S.; R. Streule; D. Läge

    2008-01-01

    BACKGROUND: In an earlier study, our research group presented an alternative approach to measuring knowledge about mental disorders by constructing a structure-based expert model of the ICD-10 mental disorders. This article presents a validation of this expert model by measuring the emergence of such knowledge structures in psychotherapy students. SAMPLING AND METHODS: The participants of a continuing education program in cognitive behavioral psychotherapy rated a selection of mental disorder...

  19. The factorial structure and validity of the Hospital Anxiety and Depression Scale (HADS) in Polish adolescents

    OpenAIRE

    Andreea Mihaela Mihalca; Władysława Pilecka

    2015-01-01

    Objectives The present study aimed to explore the factorial structure, validity and stability of the Hospital Anxiety and Depression Scale (HADS) in chronically ill and healthy Polish adolescents. Methods 146 chronically ill (girls: 57.6%) and 309 healthy (girls: 45.9%) adolescents aged between 12 and 16 years (M = 14.03; SD = 1.3) filled in an adapted version of HADS (HADS-Teen) in hospital or school settings. The one-week test-retest reliability and construct validity was analyzed...

  20. Validation of the Transient Structural Response of a Threaded Assembly: Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Doebling, Scott W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Robertson, Amy N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maupin, Ryan D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schultze, John F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cundy, Amanda L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hylok, Jeff E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2004-04-01

    This report explores the application of model validation techniques in structural dynamics. The problem of interest is the propagation of an explosive-driven mechanical shock through a complex threaded joint. The study serves the purpose of assessing whether validating a large-size computational model is feasible, which unit experiments are required, and where the main sources of uncertainty reside. The results documented here are preliminary, and the analyses are exploratory in nature. The results obtained to date reveal several deficiencies of the analysis, to be rectified in future work.

  1. An Examination of the Structure and Construct Validity of the Wender Utah Rating Scale.

    Science.gov (United States)

    Stanton, Kasey; Watson, David

    2016-01-01

    The Wender Utah Rating Scale (Ward, Wender, & Reimherr, 1993 ) has been widely used in adult attention-deficit/hyperactivity disorder (ADHD) research to assess childhood symptoms retrospectively, but little research has examined its factor structure and specificity in predicting ADHD versus other psychopathology. Consequently, this study had 2 goals: (a) to examine the Wender Utah Rating Scale's structure, and (b) to explicate the construct validity of this measure by relating factors from our structural analyses to other ADHD, psychopathology, and personality measures. Structural analyses in an adult community sample (N = 294) yielded a 3-factor structure of aggression (e.g., angry), internalizing distress (e.g., depressed), and academic difficulties (e.g., underachiever). Correlational and regression analyses indicated that these factors failed to display specificity in their associations with ADHD versus other psychopathology. Aggression and internalizing distress associated most strongly with indicators of externalizing (e.g., ill temper, manipulativeness) and internalizing psychopathology (e.g., depression, anxiety), respectively. Academic difficulties associated most strongly with ADHD symptoms, but these relations were relatively weak. Taken together, these findings raise concerns about the Wender Utah Rating Scale's construct validity, although additional longitudinal research is needed to clarify to what extent the Wender Utah Rating Scale validly assesses childhood ADHD symptoms. PMID:27050760

  2. Development of the chronic obstructive pulmonary disease activity rating scale: reliability, validity and factorial structure.

    Science.gov (United States)

    Morimoto, Michiko; Takai, Kenichi; Nakajima, Kazuo; Kagawa, Koujiro

    2003-03-01

    The purpose of the present study was to develop the Chronic Obstructive Pulmonary Disease (COPD) Activity Rating Scale (CARS) to measure life-related activity in patients with COPD, and to confirm its reliability and constructive validity in a factorial structure model. The subjects consisted of 114 patients with COPD. An 88-item life-related activity list, generated previously from a literature review, was administered. The secondary structural model consisted of four factors with 12 items. The results of the confirmatory factor analysis by structural equation modeling showed the fit criteria to be statistically significant. The internal consistency of the 12 items was highly reliable (Cronbach's alpha = 0.924). The CARS score was correlated with pulmonary function tests, breathlessness, and the health-related quality of life (QOL) scales in Pearson correlation coefficient. The results suggest that the COPD Activity Rating Scale is a valid scale for the assessment of life-related activity in patients with COPD. PMID:12603718

  3. Contribution to the validation of thermal ratchetting prevision methods in metallic structures; Contribution a la validation des methodes de prevision du rochet thermique dans les structures metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Rakotovelo, A.M

    1998-03-01

    This work concerns the steady state assessment in the metallic structures subjected to thermomechanical cyclic loadings in biaxial stress state. The effect of the short time mechanical overloads is also investigated. The first chapter is devoted to a bibliographic research concerning the behaviour of the materials and the structures in the cyclic plasticity. Some works relate to the experimental aspect as well as the numerical one for the steady state assessment of such structures are presented. The experimental part of the study is presented in the second chapter. The experimental device was carried out in order to prescribe tension and torsion forces combined with cyclic thermal loading. Some tests was then carried out, among these tests certain include some overloads in tension or torsion. The last chapter describes the numerical calculations using different models (linear isotropic hardening, linear kinematic hardening and elasto-viscoplastic Chaboche's model) and the application of some simplified methods for the ratchetting assessment in the structures. We have considered two categories of methods. The first one is based on an elastic analysis (Bree's diagram, 3 Sm rule, efficiency rule) and the second one combines elastic analysis and elastoplastic analysis of the first cycle (Gatt's and Taleb's methods). The results of this study have enabled: to validate in the biaxial stress state an expression which takes into account the effect of mechanical short time overloads; to test the performances of considered models to describe the evolution of the structure during the first cycle and to take into account the effect of short time overloads. Among the considered models, the elastoplastic Chaboche's model seems to be the most accurate to describe the structure's behaviour during the first cycles; to validate some simplified methods. Certain methods based only on elastic analysis (Bee's diagram and efficiency rule) seem not

  4. Validation of seismic soil structure interaction (SSI) methodology for a UK PWR nuclear power station

    International Nuclear Information System (INIS)

    The seismic loading information for use in the seismic design of equipment and minor structures within a nuclear power plant is determined from a dynamic response analysis of the building in which they are located. This dynamic response analysis needs to capture the global response of both the building structure and adjacent soil and is commonly referred to as a soil structure interaction (SSI) analysis. NNC have developed a simple and cost effective methodology for the seismic SSI analysis of buildings in a PWR nuclear power station at a UK soft site. This paper outlines the NNC methodology and describes the approach adopted for its validation

  5. Design and validation of a structural health monitoring system for aeronautical structures.

    OpenAIRE

    Tibaduiza Burgos, Diego Alexander

    2013-01-01

    Structural Health Monitoring (SHM) is an area where the main objective is the verification of the state or the health of the structures in order to ensure proper performance and maintenance cost savings using a sensor network attached to the structure, continuous monitoring and algorithms. Different benefits are derived from the implementation of SHM, some of them are: knowledge about the behavior of the structure under different loads and different environmental changes, knowledge of the cur...

  6. Analytical modeling and experimental validation of a structurally integrated piezoelectric energy harvester on a thin plate

    Science.gov (United States)

    Aridogan, U.; Basdogan, I.; Erturk, A.

    2014-04-01

    Vibration-based energy harvesting using piezoelectric cantilevers has been extensively studied over the past decade. As an alternative to cantilevered harvesters, piezoelectric patch harvesters integrated to thin plates can be more convenient for use in marine, aerospace and automotive applications since these systems are often composed of thin plate-like structures with various boundary conditions. In this paper, we present analytical electroelastic modeling of a piezoelectric energy harvester structurally integrated to a thin plate along with experimental validations. The distributed-parameter electroelastic model of the thin plate with the piezoceramic patch harvester is developed based on Kirchhoff’s plate theory for all-four-edges clamped (CCCC) boundary conditions. Closed-form steady-state response expressions for coupled electrical output and structural vibration are obtained under transverse point force excitation. Analytical electroelastic frequency response functions (FRFs) relating the voltage output and vibration response to force input are derived and generalized for different boundary conditions. Experimental validation and extensive theoretical analysis efforts are then presented with a case study employing a thin PZT-5A piezoceramic patch attached on the surface of a rectangular aluminum CCCC plate. The importance of positioning of the piezoceramic patch harvester is discussed through an analysis of dynamic strain distribution on the overall plate surface. The electroelastic model is validated by a comparison of analytical and experimental FRFs for a wide range of resistive electrical boundary conditions. Finally, power generation performance of the structurally integrated piezoceramic patch harvester from multiple vibration modes is investigated analytically and experimentally.

  7. Experimental validation of finite element and boundary element methods for predicting structural vibration and radiated noise

    Science.gov (United States)

    Seybert, A. F.; Wu, T. W.; Wu, X. F.

    1994-01-01

    This research report is presented in three parts. In the first part, acoustical analyses were performed on modes of vibration of the housing of a transmission of a gear test rig developed by NASA. The modes of vibration of the transmission housing were measured using experimental modal analysis. The boundary element method (BEM) was used to calculate the sound pressure and sound intensity on the surface of the housing and the radiation efficiency of each mode. The radiation efficiency of each of the transmission housing modes was then compared to theoretical results for a finite baffled plate. In the second part, analytical and experimental validation of methods to predict structural vibration and radiated noise are presented. A rectangular box excited by a mechanical shaker was used as a vibrating structure. Combined finite element method (FEM) and boundary element method (BEM) models of the apparatus were used to predict the noise level radiated from the box. The FEM was used to predict the vibration, while the BEM was used to predict the sound intensity and total radiated sound power using surface vibration as the input data. Vibration predicted by the FEM model was validated by experimental modal analysis; noise predicted by the BEM was validated by measurements of sound intensity. Three types of results are presented for the total radiated sound power: sound power predicted by the BEM model using vibration data measured on the surface of the box; sound power predicted by the FEM/BEM model; and sound power measured by an acoustic intensity scan. In the third part, the structure used in part two was modified. A rib was attached to the top plate of the structure. The FEM and BEM were then used to predict structural vibration and radiated noise respectively. The predicted vibration and radiated noise were then validated through experimentation.

  8. Development and initial validation of the Structured Interview for Self-Destructive Behaviors.

    Science.gov (United States)

    Carlson, Eve B; McDade-Montez, Elizabeth; Armstrong, Judith; Dalenberg, Constance; Loewenstein, Richard J

    2013-01-01

    This article describes the initial validation of the Structured Interview for Self-Destructive Behaviors (SI-SDB), a brief interview assessing suicidality, self-injury, substance abuse, disordered eating, and risky sexual behaviors. Self-destructive behaviors present clinical and practical challenges for mental health treatment providers. Participants were 217 psychiatric inpatients with a wide variety of diagnoses who completed the SI-SDB and other measures of psychiatric symptoms, trauma exposure, and other childhood experiences. Internal validity analyses revealed an internally consistent measure with 2 major factors. External validity analyses indicated that the Substance Abuse and Disordered Eating scales were predictive of related psychiatric diagnoses. All scales except Substance Abuse were significantly correlated with psychiatric symptoms and childhood abuse. These findings indicate that the SI-SDB is a valid means of assessing 5 significant domains of dangerous behaviors in clinical and research settings. Further research on the reliability of reports over time, interrater consistency, and convergent validity with longer measures of the SI-SDB domains is needed. PMID:23627480

  9. Flight validation of an embedded structural health monitoring system for an unmanned aerial vehicle

    Science.gov (United States)

    Kressel, I.; Dorfman, B.; Botsev, Y.; Handelman, A.; Balter, J.; Pillai, A. C. R.; Prasad, M. H.; Gupta, N.; Joseph, A. M.; Sundaram, R.; Tur, M.

    2015-07-01

    This paper presents the design and flight validation of an embedded fiber Bragg gratings (FBG) based structural health monitoring (SHM) system for the Indian unmanned aerial vehicle (UAV), Nishant. The embedding of the sensors was integrated with the manufacturing process, taking into account the trimming of parts and assembly considerations. Reliable flight data were recorded on board the vehicle and analyzed so that deviations from normal structural behaviors could be identified, evaluated and tracked. Based on the data obtained, it was possible to track both the loads and vibration signatures by direct sensors’ cross correlation using principal component analysis (PCA) and artificial neural networks (ANNs). Sensor placement combined with proper ground calibration, enabled the distinction between strain and temperature readings. The start of a minor local structural temporary instability was identified during landing, proving the value of such continuous structural airworthy assessment for UAV structures.

  10. A mobile sensing system for structural health monitoring: design and validation

    International Nuclear Information System (INIS)

    This paper describes a new approach using mobile sensor networks for structural health monitoring. Compared with static sensors, mobile sensor networks offer flexible system architectures with adaptive spatial resolutions. The paper first describes the design of a mobile sensing node that is capable of maneuvering on structures built with ferromagnetic materials. The mobile sensing node can also attach/detach an accelerometer onto/from the structural surface. The performance of the prototype mobile sensor network has been validated through laboratory experiments. Two mobile sensing nodes are adopted for navigating on a steel portal frame and providing dense acceleration measurements. Transmissibility function analysis is conducted to identify structural damage using data collected by the mobile sensing nodes. This preliminary work is expected to spawn transformative changes in the use of mobile sensors for future structural health monitoring

  11. Experimental validation of multistep quantitative crack damage assessment for truss structures by finite element model updating

    International Nuclear Information System (INIS)

    In this paper, a multistep damage quantification method has been experimentally validated by quantifying crack damage of load-carrying members of truss structures based on experimental vibration records. Damage quantifications are still challenging tasks for difficulties in interpreting response signals measured from engineering structures. Open crack depth is parameterized as a damage variable. The open crack in Euler–Bernoulli beam element is modeled by introducing local flexibility coefficients to the uncracked beam element with joint rotational flexibility. Mode shapes and natural frequencies measured from experimental modal testing of a damaged laboratory-size truss bridge are used in the finite element model updating for damage quantification. Predetermined curves derived for hollow circular sections with open crack are used to estimate crack depths from updated local flexibility coefficients. According to experimental validation test, the proposed approach is proven to be viable in quantifying crack damage. (paper)

  12. Testing the validity of the Feldstein-Horioka Puzzle: New evidence from structural breaks for Turkey

    OpenAIRE

    Erdem, Ekrem; Ahmet KOSEOGLU; Ali Gokhan YUCEL

    2016-01-01

    The purpose of this study is to test the validity of Feldstein-Horioka Puzzle using time series data covering the period of 1960-2014 for Turkey. In order to test this relationship, the recently proposed multiple-break cointegration test of Maki (2012) was employed. After detecting the existence of a cointegration between domestic saving by allowing for endogenous structural breaks, Fully Modified Ordinary Least Squares (FMOLS) and Dynamic Ordinary Least Squares (DOLS) estimati...

  13. Validity of internal structure of the Competitive State Anxiety Inventory in a Brazilian sample

    OpenAIRE

    Daniel Bartholomeu; José Maria Montiel; Afonso Antonio Machado

    2014-01-01

    This study investigated internal structure validity of the CSAI-2. The sample comprised 172 in Brazilian athletes, both sexes and ages ranging from 14 to 58 years. The athletes attended to the following sports: basketball, soccer, handball, volleyball and jiu-jitsu. The CSAI-2 was collectively applied before training. Initially a confirmatory factor analysis was done, but the data did not fit the model. Then, an exploratory factor analysis was conducted and, although the parallel analysis poi...

  14. The Dimensional Structure of the Wisconsin Schizotypy Scales: Factor Identification and Construct Validity

    OpenAIRE

    Kwapil, Thomas R.; Barrantes-Vidal, Neus; Silvia, Paul J.

    2007-01-01

    The present study examined the factor structure underlying the Wisconsin Schizotypy Scales and the validity of these dimensions. Confirmatory factor analysis with 6137 nonclinical young adults supported a 2-factor model with positive and negative schizotypy dimensions. As predicted, the schizotypy dimensions were differentially related to psychopathology, personality, and social impairment. Both dimensions were related to schizotypal and paranoid symptoms. Positive schizotypy was uniquely rel...

  15. All-Atom Molecular Dynamics Simulations Reveal Significant Differences in Interaction between Antimycin and Conserved Amino Acid Residues in Bovine and Bacterial bc1 Complexes

    OpenAIRE

    Kokhan, Oleksandr; Shinkarev, Vladimir P.

    2011-01-01

    Antimycin A is the most frequently used specific and powerful inhibitor of the mitochondrial respiratory chain. We used all-atom molecular dynamics (MD) simulations to study the dynamic aspects of the interaction of antimycin A with the Qi site of the bacterial and bovine bc1 complexes embedded in a membrane. The MD simulations revealed considerable conformational flexibility of antimycin and significant mobility of antimycin, as a whole, inside the Qi pocket. We conclude that many of the dif...

  16. Probing the global and local dynamics of aminoacyl-tRNA synthetases using all-atom and coarse-grained simulations

    OpenAIRE

    Strom, Alexander M.; Fehling, Samuel C.; Bhattacharyya, Sudeep; Hati, Sanchita

    2014-01-01

    Coarse-grained simulations have emerged as invaluable tools for studying conformational changes in biomolecules. To evaluate the effectiveness of computationally inexpensive coarse-grained models in studying global and local dynamics of large protein systems like aminoacyl-tRNA synthetases, we have performed coarse-grained normal mode analysis, as well as principle component analysis on trajectories of all-atom and coarse-grained molecular dynamics simulations for three aminoacyl-tRNA synthet...

  17. ESTEST: a framework for the validation and verification of electronic structure codes

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Gary; Gygi, Francois, E-mail: gmyuan@ucdavis.edu, E-mail: fgygi@ucdavis.edu [Department of Applied Science, University of California Davis, Davis, CA 95616 (United States)

    2010-01-15

    We present a framework for the verification and validation (V and V) of electronic structure simulation software. Electronic structure computations involve numerous parameters and approximations that determine their accuracy and reliability. As a large number of simulation data coming from several electronic structure codes are becoming available, the associated V and V process is becoming increasingly complex. We introduce ESTEST as a framework for facilitating the verification and validation of electronic structure computations. ESTEST software enables the V and V, comparison and sharing of simulation data by constructing a unified representation of code outputs, populating and organizing a query database with these representations and interfacing the data through a web service that offers ways to search, view, compare, visualize and post-process the data. We present examples of V and V as well as comparison and analysis from our implementation, and justify the details of each of the innovative features of this software. The present implementation supports electronic structure codes such as Qbox, Quantum Espresso, ABINIT, and the Exciting code. An online demonstration is available at http://estest.ucdavis.edu.

  18. Validation of a unique concept for a low-cost, lightweight space-deployable antenna structure

    Science.gov (United States)

    Freeland, R. E.; Bilyeu, G. D.; Veal, G. R.

    1993-01-01

    An experiment conducted in the framework of a NASA In-Space Technology Experiments Program based on a concept of inflatable deployable structures is described. The concept utilizes very low inflation pressure to maintain the required geometry on orbit and gravity-induced deflection of the structure precludes any meaningful ground-based demonstrations of functions performance. The experiment is aimed at validating and characterizing the mechanical functional performance of a 14-m-diameter inflatable deployable reflector antenna structure in the orbital operational environment. Results of the experiment are expected to significantly reduce the user risk associated with using large space-deployable antennas by demonstrating the functional performance of a concept that meets the criteria for low-cost, lightweight, and highly reliable space-deployable structures.

  19. Assessing the diagnostic validity of a structured psychiatric interview in a first-admission hospital sample

    DEFF Research Database (Denmark)

    Frederiksen, Julie Elisabeth Nordgaard; Revsbech, Rasmus; Sæbye, Ditte;

    2012-01-01

    The use of structured psychiatric interviews performed by non-clinicians is frequent for research purposes and is becoming increasingly common in clini-cal practice. The validity of such interviews has rarely been evaluated empirically. In this study of a sample of 100 diagnostically heterogeneous......, first-admitted inpatients, the results of an assessment with the Structured Clinical Interview for DSM-IV (SCID), yielding a DSM-IV diagnosis and performed by a trained non-clinician, were compared with a consensus lifetime best diagnostic estimate (DSM-IV) by two experienced research clinicians, based...... on multiple sources of information, which included videotaped comprehensive semi-structured narrative interviews. The overall kappa agreement was 0.18. The sensitivity and specificity for the diagnosis of schizophrenia by SCID were 19% and 100%, respectively. It is concluded that structured...

  20. The validity and clinical utility of structured diagnoses of antisocial personality disorder with forensic patients.

    Science.gov (United States)

    Marin-Avellan, Luisa E; McGauley, Gillian A; Campbell, Colin D; Fonagy, Peter

    2014-08-01

    Current DSM-based instruments for personality disorders (PDs) limit the investigation of the course and outcome of treatment of these disorders. This study examined the validity of the Shedler-Westen Assessment Procedure-200 (SWAP-200) and the Structured Clinical Interview for DSM-IV Axis II PD (SCID-II) in a sample of forensic PD patients. Results based on 66 participants indicated that the SWAP-200 Q-factors reduced the frequency of diagnostic comorbidity of PD categories by half compared with the SCID-II. Only the SWAP-200's Antisocial PD category showed good convergent and discriminant validity with respect to other instruments describing aspects of PD. The validity of the cutoff score for severe antisocial PD was confirmed, and this category predicted severe incidents in the hospital at 1 year of follow-up. A violence risk scale was constructed, which differentiated violent and nonviolent offenders. The results support the validity of the SWAP-200 and its potential clinical utility with forensic PD patients. PMID:24511901

  1. Full-Scale Structural and NDI Validation Tests of Bonded Composite Doublers for Commercial Aircraft Applications

    Energy Technology Data Exchange (ETDEWEB)

    Roach, D.; Walkington, P.

    1999-02-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single Boron-Epoxy composite doubler to the damaged structure. Most of the concerns surrounding composite doubler technology pertain to long-term survivability, especially in the presence of non-optimum installations, and the validation of appropriate inspection procedures. This report focuses on a series of full-scale structural and nondestructive inspection (NDI) tests that were conducted to investigate the performance of Boron-Epoxy composite doublers. Full-scale tests were conducted on fuselage panels cut from retired aircraft. These full-scale tests studied stress reductions, crack mitigation, and load transfer capabilities of composite doublers using simulated flight conditions of cabin pressure and axial stress. Also, structures which modeled key aspects of aircraft structure repairs were subjected to extreme tension, shear and bending loads to examine the composite laminate's resistance to disbond and delamination flaws. Several of the structures were loaded to failure in order to determine doubler design margins. Nondestructive inspections were conducted throughout the test series in order to validate appropriate techniques on actual aircraft structure. The test results showed that a properly designed and installed composite doubler is able to enhance fatigue life, transfer load away from damaged structure, and avoid the introduction of new stress risers (i.e. eliminate global reduction in the fatigue life of the structure). Comparisons with test data obtained prior to the doubler installation revealed that stresses in the parent material can be reduced 30%--60% through the use of the composite doubler. Tests to failure demonstrated that the bondline is able to transfer plastic strains into the doubler and that

  2. Experimental validation of an integrated controls-structures design methodology for a class of flexible space structures

    Science.gov (United States)

    Maghami, Peiman G.; Gupta, Sandeep; Elliott, Kenny B.; Joshi, Suresh M.; Walz, Joseph E.

    1994-01-01

    This paper describes the first experimental validation of an optimization-based integrated controls-structures design methodology for a class of flexible space structures. The Controls-Structures-Interaction (CSI) Evolutionary Model, a laboratory test bed at Langley, is redesigned based on the integrated design methodology with two different dissipative control strategies. The redesigned structure is fabricated, assembled in the laboratory, and experimentally compared with the original test structure. Design guides are proposed and used in the integrated design process to ensure that the resulting structure can be fabricated. Experimental results indicate that the integrated design requires greater than 60 percent less average control power (by thruster actuators) than the conventional control-optimized design while maintaining the required line-of-sight performance, thereby confirming the analytical findings about the superiority of the integrated design methodology. Amenability of the integrated design structure to other control strategies is considered and evaluated analytically and experimentally. This work also demonstrates the capabilities of the Langley-developed design tool CSI DESIGN which provides a unified environment for structural and control design.

  3. Assessment of identity disturbance: Factor structure and validation of the Personality Structure Questionnaire in an Italian sample.

    Science.gov (United States)

    Berrios, Raul; Kellett, Stephen; Fiorani, Christina; Poggioli, Marisa

    2016-04-01

    There are few brief measures of identity disturbance for use in clinical practice that have been subject to any cross-cultural validation. This study investigated the construct validity of the Personality Structure Questionnaire (PSQ) in Italian clinical (N = 237) and community (N = 296) samples. Confirmatory factor analysis was conducted to investigate the internal structure of the PSQ. A 3-factor structure (i.e., differing self-states, mood variability, and behavioral loss of control) including a second-order factor provided the best fit to the data. This structure was demonstrated to be invariant across sex and clinical diagnosis, with clinical diagnosis significantly predicting increased PSQ scores. A global PSQ score of between 26 and 28 was found to be an appropriate cutoff for assisting in diagnostic processes. The clinical implication of the study is that quantitative assessment of identity disturbance can be rapidly achieved via the PSQ, usefully supplementing necessary diagnostic and formulation work. (PsycINFO Database Record PMID:26389598

  4. How to do structural validity of a system dynamics type simulation model: The case of an energy policy model

    International Nuclear Information System (INIS)

    System dynamics based simulation models are becoming increasingly popular in the analysis of important energy policy issues including global warming, deregulation, conservation and efficiency. The usefulness of these models is predicated on their ability to link observable patterns of behavior of a system to micro-level structures. This paper argues that the structural validity of the simulation model-right behavior for the right reasons-is a stringent measure to build confidence in a simulation model regardless of how well the model passes behavior validity tests. That leads to an outline of formal structural validity procedures available but less explored in system dynamics modeling 'repertoire'. An illustration of a set of six tests for structural validity of a system dynamics model for energy policy analysis follows. Then using Theil inequality statistics, the behavior validity of the model is also tested. Finally, some conclusions on the increased appeal for simulation models for energy policy analysis and design are presented.

  5. How to do structural validity of a system dynamics type simulation model. The case of an energy policy model

    International Nuclear Information System (INIS)

    System dynamics based simulation models are becoming increasingly popular in the analysis of important energy policy issues including global warming, deregulation, conservation and efficiency. The usefulness of these models is predicated on their ability to link observable patterns of behavior of a system to micro-level structures. This paper argues that the structural validity of the simulation model - right behavior for the right reasons - is a stringent measure to build confidence in a simulation model regardless of how well the model passes behavior validity tests. That leads to an outline of formal structural validity procedures available but less explored in system dynamics modeling 'repertoire'. An illustration of a set of six tests for structural validity of a system dynamics model for energy policy analysis follows. Then using Theil inequality statistics, the behavior validity of the model is also tested. Finally, some conclusions on the increased appeal for simulation models for energy policy analysis and design are presented. (author)

  6. Structural validity and reliability of the integrated conflict and violence scale.

    Science.gov (United States)

    Mutto, Milton; Lawoko, Stephen; Ovuga, Omilio; Bangdiwala, Shrikant

    2010-09-01

    The study validated structure stability, reliability and sub-scale distinctiveness of integrated conflict and violence scale (ICVS) and was cross-sectional; war-affected grade 5 school children participated. ICV internal factorial validity and reliability were evaluated; eigenvalue size and scree plots were used for factor selection. A variable retention factor load threshold of >0.30 was used: Cronbach's alpha tests confirmed reliability increments. Pair-wise Pearson correlation tests evaluated sub-scale distinctiveness. Gulu University granted ethical clearance. A total of 280 grade 5 children from 50 primary schools participated: 53% of them were males. Two factors accounted for 100% of variability in attitudes; 18 variables were retained. Expelled variables were: 'If I catch some one stealing my sugar cane I will fight' and 'a bully should be forgiven'. Sub-scale internal consistency reliability coefficients were 0.73 and 0.65, respectively and distinctiveness correlation coefficient was -0.06. The ICVS was validated using standard criteria. Emerging two-factor scale has acceptable psychometric properties especially factorial structure, internal consistency and sub-scale distinctiveness. PMID:19946812

  7. Validation of finite element and boundary element methods for predicting structural vibration and radiated noise

    Science.gov (United States)

    Seybert, A. F.; Wu, X. F.; Oswald, Fred B.

    1992-01-01

    Analytical and experimental validation of methods to predict structural vibration and radiated noise are presented. A rectangular box excited by a mechanical shaker was used as a vibrating structure. Combined finite element method (FEM) and boundary element method (BEM) models of the apparatus were used to predict the noise radiated from the box. The FEM was used to predict the vibration, and the surface vibration was used as input to the BEM to predict the sound intensity and sound power. Vibration predicted by the FEM model was validated by experimental modal analysis. Noise predicted by the BEM was validated by sound intensity measurements. Three types of results are presented for the total radiated sound power: (1) sound power predicted by the BEM modeling using vibration data measured on the surface of the box; (2) sound power predicted by the FEM/BEM model; and (3) sound power measured by a sound intensity scan. The sound power predicted from the BEM model using measured vibration data yields an excellent prediction of radiated noise. The sound power predicted by the combined FEM/BEM model also gives a good prediction of radiated noise except for a shift of the natural frequencies that are due to limitations in the FEM model.

  8. Studies of base pair sequence effects on DNA solvation based on all-atom molecular dynamics simulations

    Indian Academy of Sciences (India)

    Surjit B Dixit; Mihaly Mezei; David L Beveridge

    2012-07-01

    Detailed analyses of the sequence-dependent solvation and ion atmosphere of DNA are presented based on molecular dynamics (MD) simulations on all the 136 unique tetranucleotide steps obtained by the ABC consortium using the AMBER suite of programs. Significant sequence effects on solvation and ion localization were observed in these simulations. The results were compared to essentially all known experimental data on the subject. Proximity analysis was employed to highlight the sequence dependent differences in solvation and ion localization properties in the grooves of DNA. Comparison of the MD-calculated DNA structure with canonical A- and B-forms supports the idea that the G/C-rich sequences are closer to canonical A- than B-form structures, while the reverse is true for the poly A sequences, with the exception of the alternating ATAT sequence. Analysis of hydration density maps reveals that the flexibility of solute molecule has a significant effect on the nature of observed hydration. Energetic analysis of solute–solvent interactions based on proximity analysis of solvent reveals that the GC or CG base pairs interactmore strongly with watermolecules in the minor groove of DNA that the AT or TA base pairs, while the interactions of the AT or TA pairs in the major groove are stronger than those of the GC or CG pairs. Computation of solvent-accessible surface area of the nucleotide units in the simulated trajectories reveals that the similarity with results derived from analysis of a database of crystallographic structures is excellent. The MD trajectories tend to follow Manning’s counterion condensation theory, presenting a region of condensed counterions within a radius of about 17 Å from the DNA surface independent of sequence. The GC and CG pairs tend to associate with cations in the major groove of the DNA structure to a greater extent than the AT and TA pairs. Cation association is more frequent in the minor groove of AT than the GC pairs. In general

  9. Contribution to the validation of thermal ratchetting prevision methods in metallic structures

    International Nuclear Information System (INIS)

    This work concerns the steady state assessment in the metallic structures subjected to thermomechanical cyclic loadings in biaxial stress state. The effect of the short time mechanical overloads is also investigated. The first chapter is devoted to a bibliographic research concerning the behaviour of the materials and the structures in the cyclic plasticity. Some works relate to the experimental aspect as well as the numerical one for the steady state assessment of such structures are presented. The experimental part of the study is presented in the second chapter. The experimental device was carried out in order to prescribe tension and torsion forces combined with cyclic thermal loading. Some tests was then carried out, among these tests certain include some overloads in tension or torsion. The last chapter describes the numerical calculations using different models (linear isotropic hardening, linear kinematic hardening and elasto-viscoplastic Chaboche's model) and the application of some simplified methods for the ratchetting assessment in the structures. We have considered two categories of methods. The first one is based on an elastic analysis (Bree's diagram, 3 Sm rule, efficiency rule) and the second one combines elastic analysis and elastoplastic analysis of the first cycle (Gatt's and Taleb's methods). The results of this study have enabled: to validate in the biaxial stress state an expression which takes into account the effect of mechanical short time overloads; to test the performances of considered models to describe the evolution of the structure during the first cycle and to take into account the effect of short time overloads. Among the considered models, the elastoplastic Chaboche's model seems to be the most accurate to describe the structure's behaviour during the first cycles; to validate some simplified methods. Certain methods based only on elastic analysis (Bee's diagram and efficiency rule) seem not suitable for the considered kind of

  10. Investigation of uncertainty quantification procedure in validation process of fluid-structure thermal interaction simulation code

    International Nuclear Information System (INIS)

    A numerical simulation code MUGTHES has been developed to investigate fluid-structure thermal interaction problems in Japan sodium-cooled fast reactor (JSFR) and a procedure combined V and V of the code and numerical prediction process called as V2UP (Verification and Validation plus Uncertainty quantification and Prediction) has been developed by referring to the existing guidelines. By using numerical results by MUGTHES for the WATLON experiment which was a water experiment to investigate thermal mixing phenomena in a T-junction piping system, applicability of the GCI estimation method and the area validation metric (AVM) method and the modified one (MAVM) in the V2UP were examined. Through the examinations, it was found that the GCI estimation by using the modified least-square version was applicable and the AVM and the MAVM methods were applicable if transient data were obtained in the experiment. (author)

  11. The Structure of Preschoolers' Emotion Knowledge: Model Equivalence and Validity Using a Structural Equation Modeling Approach

    Science.gov (United States)

    Bassett, Hideko Hamada; Denham, Susanne; Mincic, Melissa; Graling, Kelly

    2012-01-01

    Research Findings: A theory-based 2-factor structure of preschoolers' emotion knowledge (i.e., recognition of emotional expression and understanding of emotion-eliciting situations) was tested using confirmatory factor analysis. Compared to 1- and 3-factor models, the 2-factor model showed a better fit to the data. The model was found to be…

  12. Construct validity of instruments measuring impairments in body structures and function in rheumatic disorders: which constructs are selected for validation? A systematic review.

    NARCIS (Netherlands)

    Swinkels, R.A.H.M.; Bouter, L.M.; Oostendorp, R.A.B.; Swinkels-Meewisse, I.J.; Dijkstra, P.U.; Vet, H.C.W. de

    2006-01-01

    PURPOSE: This paper focuses on the construct validity of instruments measuring impairments in body structures and function in rheumatic disorders. The objective is: 1) to make an inventory of constructs, based on the domains of the International Classification of Functioning, Disabilities and Health

  13. Construct validity of instruments measuring impairments in body structures and function in rheumatic disorders: Which constructs are selected for validation? A systematic review

    NARCIS (Netherlands)

    Swinkels, R.A.H.M.; Bouter, L.M.; Oostendorp, R.A.B.; Swinkels-Meewisse, I.J.C.M.; Dijkstra, P.U.; de Vet, H.C.W.

    2006-01-01

    Purpose. This paper focuses on the construct validity of instruments measuring impairments in body structures and function in rheumatic disorders. The objective is: 1) to make an inventory of constructs, based on the domains of the International Classification of Functioning, Disabilities and Health

  14. Predicting novel binding modes of agonists to β adrenergic receptors using all-atom molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Stefano Vanni

    Full Text Available Understanding the binding mode of agonists to adrenergic receptors is crucial to enabling improved rational design of new therapeutic agents. However, so far the high conformational flexibility of G protein-coupled receptors has been an obstacle to obtaining structural information on agonist binding at atomic resolution. In this study, we report microsecond classical molecular dynamics simulations of β(1 and β(2 adrenergic receptors bound to the full agonist isoprenaline and in their unliganded form. These simulations show a novel agonist binding mode that differs from the one found for antagonists in the crystal structures and from the docking poses reported by in silico docking studies performed on rigid receptors. Internal water molecules contribute to the stabilization of novel interactions between ligand and receptor, both at the interface of helices V and VI with the catechol group of isoprenaline as well as at the interface of helices III and VII with the ethanolamine moiety of the ligand. Despite the fact that the characteristic N-C-C-OH motif is identical in the co-crystallized ligands and in the full agonist isoprenaline, the interaction network between this group and the anchor site formed by Asp(3.32 and Asn(7.39 is substantially different between agonists and inverse agonists/antagonists due to two water molecules that enter the cavity and contribute to the stabilization of a novel network of interactions. These new binding poses, together with observed conformational changes in the extracellular loops, suggest possible determinants of receptor specificity.

  15. DCC: a Swiss army knife for structure factor analysis and validation

    Science.gov (United States)

    Yang, Huanwang; Peisach, Ezra; Westbrook, John D.; Young, Jasmine; Berman, Helen M.; Burley, Stephen K.

    2016-01-01

    Since 2008, X-ray structure depositions to the Protein Data Bank archive (PDB) have required submission of experimental data in the form of structure factor files. RCSB PDB has developed the program DCC to allow worldwide PDB (wwPDB; http://wwpdb.org) biocurators, using a single command-line program, to invoke a number of third-party software packages to compare the model file with the experimental data. DCC functionality includes structure factor validation, electron-density map generation and slicing, local electron-density analysis, and residual B factor analysis. DCC outputs a summary containing various crystallographic statistics in PDBx/mmCIF format for use in automatic data processing and archiving pipelines.

  16. Validation of the magnetic energy vs. helicity scaling in solar magnetic structures

    CERN Document Server

    Tziotziou, K; Georgoulis, M K; Archontis, V

    2014-01-01

    We assess the validity of the free magnetic energy - relative magnetic helicity diagram for solar magnetic structures. We used two different methods of calculating the free magnetic energy and the relative magnetic helicity budgets: a classical, volume-calculation nonlinear force-free (NLFF) method applied to finite coronal magnetic structures and a surface-calculation NLFF derivation that relies on a single photospheric or chromospheric vector magnetogram. Both methods were applied to two different data sets, namely synthetic active-region cases obtained by three-dimensional magneto-hydrodynamic (MHD) simulations and observed active-region cases, which include both eruptive and noneruptive magnetic structures. The derived energy--helicity diagram shows a consistent monotonic scaling between relative helicity and free energy with a scaling index 0.84$\\pm$0.05 for both data sets and calculation methods. It also confirms the segregation between noneruptive and eruptive active regions and the existence of thresh...

  17. Mechanism of PhosphoThreonine/Serine Recognition and Specificity for Modular Domains from All-atom Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Huang Yu-ming M

    2011-05-01

    Full Text Available Abstract Background Phosphopeptide-binding domains mediate many vital cellular processes such as signal transduction and protein recognition. We studied three well-known domains important for signal transduction: BRCT repeats, WW domain and forkhead-associated (FHA domain. The first two recognize both phosphothreonine (pThr and phosphoserine (pSer residues, but FHA has high specificity for pThr residues. Here we used molecular dynamics (MD simulations to reveal how FHA exclusively chooses pThr and how BRCT and WW recognize both pThr/pSer. The work also investigated the energies and thermodynamic information of intermolecular interactions. Results Simulations carried out included wide-type and mutated systems. Through analysis of MD simulations, we found that the conserved His residue defines dual loops feature of the FHA domain, which creates a small cavity reserved for only the methyl group of pThr. These well-organized loop interactions directly response to the pThr binding selectivity, while single loop (the 2nd phosphobinding site of FHA or in combination with α-helix (BRCT repeats or β-sheet (WW domain fail to differentiate pThr/pSer. Conclusions Understanding the domain pre-organizations constructed by conserved residues and the driving force of domain-phosphopeptide recognition provides structural insight into pThr specific binding, which also helps in engineering proteins and designing peptide inhibitors.

  18. Impact of Cross-Axis Structural Dynamics on Validation of Linear Models for Space Launch System

    Science.gov (United States)

    Pei, Jing; Derry, Stephen D.; Zhou Zhiqiang; Newsom, Jerry R.

    2014-01-01

    A feasibility study was performed to examine the advisability of incorporating a set of Programmed Test Inputs (PTIs) during the Space Launch System (SLS) vehicle flight. The intent of these inputs is to provide validation to the preflight models for control system stability margins, aerodynamics, and structural dynamics. During October 2009, Ares I-X program was successful in carrying out a series of PTI maneuvers which provided a significant amount of valuable data for post-flight analysis. The resulting data comparisons showed excellent agreement with the preflight linear models across the frequency spectrum of interest. However unlike Ares I-X, the structural dynamics associated with the SLS boost phase configuration are far more complex and highly coupled in all three axes. This presents a challenge when implementing this similar system identification technique to SLS. Preliminary simulation results show noticeable mismatches between PTI validation and analytical linear models in the frequency range of the structural dynamics. An alternate approach was examined which demonstrates the potential for better overall characterization of the system frequency response as well as robustness of the control design.

  19. Experimental validation of the fluid-structure interaction simulation of a bioprosthetic aortic heart valve.

    Science.gov (United States)

    Kemp, I; Dellimore, K; Rodriguez, R; Scheffer, C; Blaine, D; Weich, H; Doubell, A

    2013-09-01

    Experiments performed on a 19 mm diameter bioprosthetic valve were used to successfully validate the fluid-structure interaction (FSI) simulation of an aortic valve at 72 bpm. The FSI simulation was initialized via a novel approach utilizing a Doppler sonogram of the experimentally tested valve. Using this approach very close quantitative agreement (≤12.5%) between the numerical predictions and experimental values for several key valve performance parameters, including the peak systolic transvalvular pressure gradient, rapid valve opening time and rapid valve closing time, was obtained. The predicted valve leaflet kinematics during opening and closing were also in good agreement with the experimental measurements. PMID:23907849

  20. Experimental validation of the fluid–structure interaction simulation of a bioprosthetic aortic heart valve

    International Nuclear Information System (INIS)

    Experiments performed on a 19 mm diameter bioprosthetic valve were used to successfully validate the fluid–structure interaction (FSI) simulation of an aortic valve at 72 bpm. The FSI simulation was initialized via a novel approach utilizing a Doppler sonogram of the experimentally tested valve. Using this approach very close quantitative agreement (≤12.5 %) between the numerical predictions and experimental values for several key valve performance parameters, including the peak systolic transvalvular pressure gradient, rapid valve opening time and rapid valve closing time, was obtained. The predicted valve leaflet kinematics during opening and closing were also in good agreement with the experimental measurements.

  1. Assessing the diagnostic validity of a structured psychiatric interview in a first-admission hospital sample

    DEFF Research Database (Denmark)

    Frederiksen, Julie Elisabeth Nordgaard; Revsbech, Rasmus; Sæbye, Ditte;

    2012-01-01

    , first-admitted inpatients, the results of an assessment with the Structured Clinical Interview for DSM-IV (SCID), yielding a DSM-IV diagnosis and performed by a trained non-clinician, were compared with a consensus lifetime best diagnostic estimate (DSM-IV) by two experienced research clinicians, based...... interviews performed by non-clinicians are not recommendable for clinical work and should only be used in research with certain precautions. It is suggested that a revival of systematic theoretical and practical training in psychopathology is an obvious way forward in order to improve the validity and...

  2. Structural Validity of ‘Santa Clara Strength of Religious Faith Questionnaire’ in Greek Sample

    Directory of Open Access Journals (Sweden)

    Maria Dianni

    2014-02-01

    Full Text Available The aim of the present study was to investigate the structural validity and reliability of the Santa Clara Strength of Religious Faith Questionnaire (SCSRFQ instrument in the Greek population. One hundred and three individuals (men n = 45, and women n = 58 participated in this study. Their age ranged from 17 to 86 years. More specifically, the study investigated the fit of both versions of SCSRFQ (10-item and 5-item. The results of the present study revealed that both versions have adequate fit and can be used by Greek researchers as a measure of strength of religious faith in the Greek population.

  3. Development and validation of a strain-based Structural Health Monitoring system

    Science.gov (United States)

    Katsikeros, Ch. E.; Labeas, G. N.

    2009-02-01

    An innovative Structural Health Monitoring (SHM) methodology, based on structural strain measurements, which are processed by a back-propagation feed-forward Artificial Neural Network (ANN), is proposed. The demonstration of the SHM methodology and the identification of its capabilities and drawbacks are performed by applying the method in the prediction of fatigue damage states of a typical aircraft cracked lap-joint structure. An ANN of suitable architecture is developed and trained by numerically generated strain data sets, which have been preprocessed by Fast Fourier Transformation (FFT) for the extraction of the Fourier Descriptors (FDs). The Finite Element (FE) substructuring technique is implemented in the stress and strain analysis of the lap-joint structure, due to its efficiency in the calculation of the numerous strain data, which are necessary for the ANN training. The trained network is successfully validated, as it is proven capable to accurately predict crack positions and lengths of a lap-joint structure, which is damaged by fatigue cracks of unknown location and extent. The proposed methodology is applicable to the identification of more complex types of damage or to other critical structural locations, as its basic concept is generic.

  4. Validation Study of a Method for Assessing Complex Ill-Structured Problem Solving by Using Causal Representations

    Science.gov (United States)

    Eseryel, Deniz; Ifenthaler, Dirk; Ge, Xun

    2013-01-01

    The important but little understood problem that motivated this study was the lack of research on valid assessment methods to determine progress in higher-order learning in situations involving complex and ill-structured problems. Without a valid assessment method, little progress can occur in instructional design research with regard to designing…

  5. The reliability, validity, and usefulness of the Objective Structured Clinical Examination (OSCE) in dental education

    Science.gov (United States)

    Graham, Roseanna

    This study evaluated the reliability, validity, and educational usefulness of a comprehensive, multidisciplinary Objective Structured Clinical Examination (OSCE) in dental education. The OSCE was administered to dental students at the Columbia University College of Dental Medicine (CDM) before they entered clinical training. Participants in this study included CDM's class of 2010 which consisted of 78 students. The overall reliability of the examination was measured via calculation of Cronbach's alpha. Content validity was examined through evaluation of the OSCE by three experienced clinical faculty members. Predictive validity was evaluated by correlating student grades on the OSCE to future clinical performance as measured by number of clinical points achieved during the third year of training. Student perceptions regarding the educational usefulness of the examination were evaluated through a 12-question Liken-type survey and focus group interviews analyzed using a phenomenological approach. Findings of the study indicated the OSCE was a highly reliable examination (alpha=0.86) with high content validity and a moderately high correlation to future clinical performance (r=.614, p<.0001). Overall, student perceptions of the educational usefulness of the OSCE were positive as based on their responses to a 5-point Likert scale (1=strongly disagree and 5=strongly agree). They reported that the exam required the ability to think critically and problem-solve (4.0 +/- 0.85), assessed clinically relevant skills (4.59 +/- 0.69), helped identify clinical weaknesses (4.16 +/- 0.90), and was a learning experience (4.58 +/- 0.84). Findings from the qualitative portion of the study identified four main themes including the student perception that the OSCE is a unique assessment experience that required integration and application of knowledge. Recommendations for the use of the OSCE to improve clinical teaching and the implications of this study relating to the expanded use of

  6. Free kick instead of cross-validation in maximum-likelihood refinement of macromolecular crystal structures

    International Nuclear Information System (INIS)

    The maximum-likelihood free-kick target, which calculates model error estimates from the work set and a randomly displaced model, proved superior in the accuracy and consistency of refinement of crystal structures compared with the maximum-likelihood cross-validation target, which calculates error estimates from the test set and the unperturbed model. The refinement of a molecular model is a computational procedure by which the atomic model is fitted to the diffraction data. The commonly used target in the refinement of macromolecular structures is the maximum-likelihood (ML) function, which relies on the assessment of model errors. The current ML functions rely on cross-validation. They utilize phase-error estimates that are calculated from a small fraction of diffraction data, called the test set, that are not used to fit the model. An approach has been developed that uses the work set to calculate the phase-error estimates in the ML refinement from simulating the model errors via the random displacement of atomic coordinates. It is called ML free-kick refinement as it uses the ML formulation of the target function and is based on the idea of freeing the model from the model bias imposed by the chemical energy restraints used in refinement. This approach for the calculation of error estimates is superior to the cross-validation approach: it reduces the phase error and increases the accuracy of molecular models, is more robust, provides clearer maps and may use a smaller portion of data for the test set for the calculation of Rfree or may leave it out completely

  7. Validation of New Process Models for Large Injection-Molded Long-Fiber Thermoplastic Composite Structures

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Kunc, Vlastimil; Tucker III, Charles L.

    2012-02-23

    This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oak Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6.

  8. Factor structure and construct validity of the Behavioral Dyscontrol Scale-II.

    Science.gov (United States)

    Shura, Robert D; Rowland, Jared A; Yoash-Gantz, Ruth E

    2015-01-01

    The Behavioral Dyscontrol Scale-II (BDS-II) was developed as an improved scoring method to the original BDS, which was designed to evaluate the capacity for independent regulation of behavior and attention. The purpose of this study was to evaluate the factor structure and construct validity of the BDS-II, which had not been adequately re-examined since the development of the new scoring system. In a sample of 164 Veterans with a mean age of 35 years, exploratory factor analysis was used to evaluate BDS-II latent factor structure. Correlations and regressions were used to explore validity against 22 psychometrically sound neurocognitive measures across seven neurocognitive domains of sensation, motor output, processing speed, attention, visual-spatial reasoning, memory, and executive functions. Factor analysis found a two-factor solution for this sample which explained 41% of the variance in the model. Validity analyses found significant correlations among the BDS-II scores and all other cognitive domains except sensation and language (which was not evaluated). Hierarchical regressions revealed that PASAT performance was strongly associated with all three BDS-II scores; dominant hand Finger Tapping Test was also associated with the Total score and Factor 1, and CPT-II Commissions was also associated with Factor 2. These results suggest the BDS-II is both a general test of cerebral functioning, and a more specific test of working memory, motor output, and impulsivity. The BDS-II may therefore show utility with younger populations for measuring frontal lobe abilities and might be very sensitive to neurological injury. PMID:25650736

  9. Predicting IQ change from brain structure: A cross-validation study

    Science.gov (United States)

    Price, C.J.; Ramsden, S.; Hope, T.M.H.; Friston, K.J.; Seghier, M.L.

    2013-01-01

    Procedures that can predict cognitive abilities from brain imaging data are potentially relevant to educational assessments and studies of functional anatomy in the developing brain. Our aim in this work was to quantify the degree to which IQ change in the teenage years could be predicted from structural brain changes. Two well-known k-fold cross-validation analyses were applied to data acquired from 33 healthy teenagers – each tested at Time 1 and Time 2 with a 3.5 year interval. One approach, a Leave-One-Out procedure, predicted IQ change for each subject on the basis of structural change in a brain region that was identified from all other subjects (i.e., independent data). This approach predicted 53% of verbal IQ change and 14% of performance IQ change. The other approach used half the sample, to identify regions for predicting IQ change in the other half (i.e., a Split half approach); however – unlike the Leave-One-Out procedure – regions identified using half the sample were not significant. We discuss how these out-of-sample estimates compare to in-sample estimates; and draw some recommendations for k-fold cross-validation procedures when dealing with small datasets that are typical in the neuroimaging literature. PMID:23567505

  10. Molecular dynamics study of human carbonic anhydrase II in complex with Zn(2+) and acetazolamide on the basis of all-atom force field simulations.

    Science.gov (United States)

    Wambo, Thierry O; Chen, Liao Y; McHardy, Stanton F; Tsin, Andrew T

    2016-01-01

    Human carbonic anhydrase II (hCAII) represents an ultimate example of the perfectly efficient metalloenzymes, which is capable of catalyzing the hydration of carbon dioxide with a rate approaching the diffusion controlled limit. Extensive experimental studies of this physiologically important metalloprotein have been done to elucidate the fundamentals of its enzymatic actions: what residues anchor the Zn(2+) (or another divalent cation) at the bottom of the binding pocket; how the relevant residues work concertedly with the divalent cation in the reversible conversions between CO2 and HCO3(-); what are the protonation states of the relevant residues and acetazolamide, an inhibitor complexed with hCAII, etc. In this article, we present a detailed computational study on the basis of the all-atom CHARMM force field where Zn(2+) is represented with a simple model of divalent cation using the transferrable parameters available from the current literature. We compute the hydration free energy of Zn(2+), the characteristics of hCAII-Zn(2+) complexation, and the absolute free energy of binding acetazolamide to the hCAII-Zn(2+) complex. In each of these three problems, our computed results agree with the experimental data within the known margin of error without making any case-by-case adjustments to the parameters. The quantitatively accurate insights we gain in this all-atom molecular dynamics study should be helpful in the search and design of more specific inhibitors of this and other carbonic anhydrases. PMID:27232456

  11. Validation of bonded composite doubler technology through application oriented structural testing

    Science.gov (United States)

    Roach, Dennis; Graf, Darin

    1996-01-01

    One of the major thrusts established under the FAA's National Aging Aircraft Research Program is to foster new technologies associated with civil aircraft maintenance. Recent DOD and other government developments in the use of bonded composite patches on metal structures has supported the need for research and validation of such doubler applications on U.S. certificated airplanes. Composite patching is a rapidly maturing technology which shows promise of cost savings on aging aircraft. Sandia Labs is conducting a proof-of-concept project with Delta Air Lines, Lockheed Martin, Textron, and the FAA which seeks to remove any remaining obstacles to the approved use of composite doublers. By focusing on a specific commercial aircraft application - reinforcement of the L-1011 door frame - and encompassing all 'cradle-to-grave' tasks such as design, analysis, installation, and inspection, this program is designed to prove the capabilities of composite doublers. This paper reports on a series of structural tests which have been conducted on coupons and subsize test articles. Tension-tension fatigue and residual strength tests attempted to grow engineered flaws in coupons with composite doublers bonded to aluminum skin. Also, structures which modeled key aspects of the door corner installation were subjected to extreme tension, shear, and bending loads. In this manner it was possible to study strain fields in and around the Lockheed-designed composite doubler using realistic aircraft load scenarios and to assess the potential for interply delaminations and disbonds between the aluminum and the laminate. The data acquired was also used to validate finite element models (FEM) and associated Damage Tolerance Analyses.

  12. Prediction of proton chemical shifts in RNA - Their use in structure refinement and validation

    International Nuclear Information System (INIS)

    An analysis is presented of experimental versus calculated chemical shifts of the non-exchangeable protons for 28 RNA structures deposited in the Protein Data Bank, covering a wide range of structural building blocks. We have used existing models for ring-current and magnetic-anisotropy contributions to calculate the proton chemical shifts from the structures. Two different parameter sets were tried: (i) parameters derived by Ribas-Prado and Giessner-Prettre (GP set) [(1981) J. Mol. Struct.,76, 81-92.]; (ii) parameters derived by Case [(1995) J. Biomol. NMR, 6, 341-346]. Both sets lead to similar results. The detailed analysis was carried using the GP set. The root-mean-square-deviation between the predicted and observed chemical shifts of the complete database is 0.16 ppm with a Pearson correlation coefficient of 0.79. For protons in the usually well-defined A-helix environment these numbers are, 0.08 ppm and 0.96, respectively. As a result of this good correspondence, a reliable analysis could be made of the structural dependencies of the 1H chemical shifts revealing their physical origin. For example, a down-field shift of either H2' or H3' or both indicates a high-syn/syn χ-angle. In an A-helix it is essentially the 5'-neighbor that affects the chemical shifts of H5, H6 and H8 protons. The H5, H6 and H8 resonances can therefore be assigned in an A-helix on the basis of their observed chemical shifts. In general, the chemical shifts were found to be quite sensitive to structural changes. We therefore propose that a comparison between calculated and observed 1H chemical shifts is a good tool for validation and refinement of structures derived from NOEs and J-couplings

  13. Objective Structured Clinical Examinations Provide Valid Clinical Skills Assessment in Emergency Medicine Education

    Directory of Open Access Journals (Sweden)

    Wallenstein, Joshua

    2014-12-01

    Full Text Available Introduction: Evaluation of emergency medicine (EM learners based on observed performance in the emergency department (ED is limited by factors such as reproducibility and patient safety. EM educators depend on standardized and reproducible assessments such as the objective structured clinical examination (OSCE. The validity of the OSCE as an evaluation tool in EM education has not been previously studied. The objective was to assess the validity of a novel management-focused OSCE as an evaluation instrument in EM education through demonstration of performance correlation with established assessment methods and case item analysis. Methods: We conducted a prospective cohort study of fourth-year medical students enrolled in a required EM clerkship. Students enrolled in the clerkship completed a five-station EM OSCE. We used Pearson’s coefficient to correlate OSCE performance with performance in the ED based on completed faculty evaluations. Indices of difficulty and discrimination were computed for each scoring item. Results: We found a moderate and statistically-significant correlation between OSCE score and ED performance score [r(239 =0.40, p<0.001]. Of the 34 OSCE testing items the mean index of difficulty was 63.0 (SD =23.0 and the mean index of discrimination was 0.52 (SD =0.21. Conclusion: Student performance on the OSCE correlated with their observed performance in the ED, and indices of difficulty and differentiation demonstrated alignment with published best-practice testing standards. This evidence, along with other attributes of the OSCE, attest to its validity. Our OSCE can be further improved by modifying testing items that performed poorly and by examining and maximizing the inter-rater reliability of our evaluation instrument. [West J Emerg Med. 2015;16(1:121–126.

  14. Experimental validation of a Fluid-Structure interaction model for simulating offshore floating wind turbines

    Science.gov (United States)

    Calderer, Antoni; Feist, Christ; Ruehl, Kelley; Guala, Michele; Sotiropoulos, Fotis

    2014-11-01

    A series of experiments reproducing a floating wind turbine in operational sea conditions, conducted in the St. Anthony Falls Lab. wave facility, are employed to validate the capabilities of the recently developed FSI-Levelset-CURVIB method of Calderer, Kang and Sotiropoulos (JCP 2014) to accurately predict turbine-wave interactions. The numerical approach is based on solving the Navier-Stokes equations coupled with the level set method, which is capable of carrying out LES of two-phase flows (air and water) with complex floating structures and waves. The investigated floating turbine is a 1:100 Froude scaled version of the 13.2 MW prototype designed by Sandia National Lab; it is installed on a cylindrical barge style platform which is restricted to move with two degrees of freedom, heave and pitch in the vertical plane defined by the direction of the propagating 2D waves. The computed turbine kinematics as well as the free surface elevation results are compared with the experimental data for different free decay tests and wave conditions representative of the Maine and the Pacific North West coasts. The comparison shows promising results indicating the validity of the model for simulating operational floating turbines. This work is supported by the US Department of Energy (DE-EE0005482), the University of Minnesota IREE program, and the Minnesota Supercomputing Institute.

  15. Structural Validity of the Pittsburgh Sleep Quality Index in Chinese Undergraduate Students.

    Science.gov (United States)

    Guo, Suran; Sun, Wenmei; Liu, Chang; Wu, Siwei

    2016-01-01

    The purpose of this study was to examine the structural validity of the Pittsburgh Sleep Quality Index (PSQI) in Chinese undergraduate students. A cross-sectional questionnaire survey with 631 Chinese undergraduate students was conducted, and the questionnaire package included a measure of demographic characteristics, PSQI, Chinese editions of Center for Epidemiologic Studies-Depression, State- Trait Anxiety Inventory, Rumination Response Scale, and Perceived Social Support Scale. Results showed that the item "use of sleep medicine" was not suitable for use with this population, that a two-factor model provided the best fit to the data as assessed through confirmatory factor analysis, and that other indices were consistently correlated with the sleep quality but not the sleep efficiency factor. PMID:27551270

  16. Parents' and Adolescents' Perspectives on Parenting: Evaluating Conceptual Structure, Measurement Invariance, and Criterion Validity.

    Science.gov (United States)

    Janssens, Annelies; Goossens, Luc; Van Den Noortgate, Wim; Colpin, Hilde; Verschueren, Karine; Van Leeuwen, Karla

    2015-08-01

    Uncertainty persists regarding adequate measurement of parenting behavior during early adolescence. The present study aimed to clarify the conceptual structure of parenting by evaluating three different models that include support, psychological control, and various types of behavioral control (i.e., proactive, punitive, and harsh punitive control). Furthermore, we examined measurement invariance of parenting ratings by 1,111 Flemish adolescents from Grade 7 till 9, their mother, and father. Finally, criterion validity of parenting ratings was estimated in relation to adolescent problem behavior. Results supported a five-factor parenting model indicating multiple aspects of behavioral control, with punitive and harsh punitive control as more intrusive forms and proactive control as a more supportive form. Similar constructs were measured for adolescents, mothers, and fathers (i.e., configural and metric invariance), however on a different scale (i.e., scalar noninvariance). Future research and clinical practices should acknowledge these findings in order to fully grasp the parenting process. PMID:25225229

  17. Validation of a computer based objective structured clinical examination in the assessment of undergraduate dermatology courses

    Directory of Open Access Journals (Sweden)

    Feroze Kaliyadan

    2014-01-01

    Full Text Available Many teaching centers have now adopted objective structured clinical examination (OSCE as an assessment method for undergraduate dermatology courses. A modification of the standard OSCE in dermatology is computer based or electronic OSCE (eOSCE. We attempted to validate the use of a computer-based OSCE in dermatology in a group of fifth year medical students. The scores of the students in the computer-based OSCE showed a strong positive correlation with the scores on the clinical presentation (Pearson′s co-efficient - 0.923, P value <0.000, significant at the 0.01 level and a good correlation with overall scores of the student (Pearson′s co-efficient - 0.728, P value <0.000, significant at the 0.01 level, indicating that this is a reliable method for assessment in dermatology. Generally, the students′ feedback regarding the methods was positive.

  18. Validity of internal structure of the Competitive State Anxiety Inventory in a Brazilian sample

    Directory of Open Access Journals (Sweden)

    Daniel Bartholomeu

    2014-06-01

    Full Text Available This study investigated internal structure validity of the CSAI-2. The sample comprised 172 in Brazilian athletes, both sexes and ages ranging from 14 to 58 years. The athletes attended to the following sports: basketball, soccer, handball, volleyball and jiu-jitsu. The CSAI-2 was collectively applied before training. Initially a confirmatory factor analysis was done, but the data did not fit the model. Then, an exploratory factor analysis was conducted and, although the parallel analysis pointed out the adequacy of a two factor model, the three factor model was the one that best explained the test's theory, with some items excluded from the analysis. The factor's precision was taken by means of Cronbach's alpha and item-total correlation index and showed good results.

  19. Validation of Flight Control Law Based on LFT and Structured Singular Value

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xi; LIU Lin; CHEN Zong-ji; DUAN Hai-bin

    2007-01-01

    The main goal of flight clearance is to use the structured singular value (μ) analysis of the flight control system when some parameters in the system vary in a certain range. As theμ-analysis can only be done on a linear fractional transformation (LFT) model, the first step of flight clearance is to generate the LFT model of the flight control system. In this paper, based on the introduction of basic theory of LFT and μ-analysis, an X-fighter is chosen as an example to utilize the proposed methods. In order to realize the flight clearance process automatically, a novel software package based on MATLAB programming language is developed. The results of simulation experiments validate the feasibility and effectiveness of the novel methods proposed in this paper.

  20. Structural Validity of the Pittsburgh Sleep Quality Index in Chinese Undergraduate Students

    Science.gov (United States)

    Guo, Suran; Sun, Wenmei; Liu, Chang; Wu, Siwei

    2016-01-01

    The purpose of this study was to examine the structural validity of the Pittsburgh Sleep Quality Index (PSQI) in Chinese undergraduate students. A cross-sectional questionnaire survey with 631 Chinese undergraduate students was conducted, and the questionnaire package included a measure of demographic characteristics, PSQI, Chinese editions of Center for Epidemiologic Studies-Depression, State- Trait Anxiety Inventory, Rumination Response Scale, and Perceived Social Support Scale. Results showed that the item “use of sleep medicine” was not suitable for use with this population, that a two-factor model provided the best fit to the data as assessed through confirmatory factor analysis, and that other indices were consistently correlated with the sleep quality but not the sleep efficiency factor. PMID:27551270

  1. The Structural Validity of the Perceived Traits of the "Ideal Student" Multi-Faceted Theory among Education Students

    Science.gov (United States)

    Maslovaty, Nava; Cohen, Arie; Furman, Sari

    2008-01-01

    The article presents a multi-faceted theory of "ideal high school student" traits. The trait system, as defined by several theories, is a translation of the teachers' belief system into educational objectives. The study focused on Bloom's taxonomies and the structural validity of its principles, using Similarity Structure Analysis. Aware of the…

  2. A validation of the Experiences in Close Relationships-Relationship Structures scale (ECR-RS) in adolescents

    DEFF Research Database (Denmark)

    Donbaek, Dagmar Feddern; Elklit, Ask

    2014-01-01

    Emerging evidence points toward a two-dimensional attachment construct: avoidance and anxiety. The Experiences in Close Relationships-Relationship Structures scale (ECR-RS; Fraley, Heffernan, Vicary, & Brumbaugh, 2011) is a questionnaire assessing two-dimensional relationship-specific attachment......, exhibiting satisfactory construct validity, including factorspecific links to the model of adult attachment (Bartholomew & Horowitz, 1991), and independent factor discrimination between subgroups. A robust validation supports the application of the ECR-RS to assessing relationship-specific adolescent...

  3. A structural approach to assessing postponement strategies: construct development and validation

    OpenAIRE

    Saghiri, Soroosh

    2011-01-01

    Abstract This paper endeavours to introduce and validate constructs and measured variables for postponement strategies. Although empirical researchers have examined postponement, a consistent set of valid, reliable factors has not been developed and used. The lack of valid construct is a barrier to hypothesis testing and meta-analysis on postponement. Using confirmatory factor analysis (CFA), the validity and reliability of the proposed postponement constructs are examined. Thi...

  4. Development and validation of a three-dimensional ring-based structural tyre model

    Science.gov (United States)

    Kindt, P.; Sas, P.; Desmet, W.

    2009-10-01

    This paper presents a structural model for an unloaded tyre, based on a three-dimensional flexible ring on an elastic foundation. The ring represents the belt and the elastic foundation represents the tyre sidewall. The model is valid up to 300 Hz and includes a submodel of the wheel and the air cavity. This makes the model potentially suitable for the prediction of structure-borne interior noise. Unlike most ring models, which only consider in-plane modes, the presented model also predicts the modes that involve torsion of the belt in circumferential direction. The parameterization of the model, which does not require detailed knowledge of the tyre construction, is based on the main geometrical properties of the tyre and a limited modal test. Comparison between measured and calculated responses shows that the tyre-wheel model describes the dynamic behaviour with acceptable accuracy. Since the model is physical, it can be applied to describe other operational conditions such as loading and rotation.

  5. Hydrologic validation of a structure-from-motion DEM derived from low-altitude UAV imagery

    Science.gov (United States)

    Steiner, Florian; Marzolff, Irene; d'Oleire-Oltmanns, Sebastian

    2015-04-01

    The increasing ease of use of current Unmanned Aerial Vehicles (UAVs) and 3D image processing software has spurred the number of applications relying on high-resolution topographic datasets. Of particular significance in this field is "structure from motion" (SfM), a photogrammetric technique used to generate low-cost digital elevation models (DEMs) for erosion budgeting, measuring of glaciers/lava-flows, archaeological applications and others. It was originally designed to generate 3D-models of buildings, based on unordered collections of images and has become increasingly common in geoscience applications during the last few years. Several studies on the accuracy of this technique already exist, in which the SfM data is mostly compared with Lidar-generated terrain data. The results are mainly positive, indicating that the technique is suitable for such applications. This work aims at validating very high resolution SfM DEMs with a different approach: Not the original elevation data is validated, but data on terrain-related hydrological and geomorphometric parameters derived from the DEM. The study site chosen for this analysis is an abandoned agricultural field near the city of Taroudant, in the semi-arid southern part of Morocco. The site is characterized by aggressive rill and gully erosion and is - apart from sparsely scattered shrub cover - mainly featureless. An area of 5.7 ha, equipped with 30 high-precision ground control points (GCPs), was covered with an unmanned aerial vehicle (UAV) in two different heights (85 and 170 m). A selection of 160 images was used to generate several high-resolution DEMs (2 and 5 cm resolution) of the area using the fully automated SfM software AGISOFT Photoscan. For comparison purposes, a conventional photogrammetry-based workflow using the Leica Photogrammetry Suite was used to generate a DEM with a resolution of 5 cm (LPS DEM). The evaluation is done by comparison of the SfM DEM with the derived orthoimages and the LPS DEM

  6. Contribution of the JRC to test and validate innovation systems for earthquake protection and control of vibration of structures

    International Nuclear Information System (INIS)

    The mission of JRC is to provide scientific and technical support for the conception, development and monitoring of EU policies. The task of IPSC is to provide cyber-security and fight against the fraud; natural, technological and economic risks; humanitarian security, non-proliferation and nuclear safeguards. The Structural mechanics laboratory supplies pseudo-dynamic testing of full/large scale models and structures. Earthquake simulation is provided by two complementary approaches: shaking table, and reaction wall. The main objectives of the large scale testing are: to calibrate analytical models suitable for different classes of structures; to validate rules of norms and standards; and to contribute to the development of innovative technologies for the protection of structures of both civil and architectural interest. Seismic isolation program deals with validation of the pseudo-dynamic method for testing large models of base isolated structures

  7. Vocalist - an international programme for the validation of constraint based methodology in structural integrity

    International Nuclear Information System (INIS)

    The pattern of crack-tip stresses and strains causing plastic flow and fracture in components is different to that in test specimens. This gives rise to the so-called constraint effect. Crack-tip constraint in components is generally lower than in test specimens. Effective toughness is correspondingly higher. The fracture toughness measured on test specimens is thus likely to underestimate that exhibited by cracks in components. A 36-month programme was initiated in October 2000 as part of the Fifth Framework of the European Atomic Energy Community (EURATOM), with the objective of achieving (i) an improved defect assessment methodology for predicting safety margins; (ii) improved lifetime management arguments. The programme VOCALIST (Validation of Constraint Based Methodology in Structural Integrity) is one of a 'cluster' of Fifth Framework projects in the area of Plant Life Management (Nuclear Fission). VOCALIST is also an associated project of NESC (Network for Evaluating Steel Components). The present paper describes the aims and objectives of VOCALIST, its interactions with NESC, and gives details of its various Work Packages. (authors)

  8. Validating estimates of the growth rate of structure with modified gravity simulations

    CERN Document Server

    Barreira, Alexandre; Schmidt, Fabian

    2016-01-01

    We perform a consistent end-to-end validation of estimates of the growth rate of structure, described by the parameter combination $f\\sigma_8$, in modified gravity cosmologies. We consider an analysis pipeline based on the redshift-space distortion modelling of the clustering wedges statistic of the galaxy correlation function and apply it to mock catalogues of $\\Lambda{\\rm CDM}$ and the normal branch of DGP cosmologies. We employ a halo occupation distribution approach to construct our mocks, which we ensure resemble the CMASS sample from BOSS in terms of the total galaxy number density and large scale amplitude of the power spectrum monopole. We show that the clustering wedges model successfully recovers the true growth rate difference between DGP and $\\Lambda{\\rm CDM}$, even for cases with over 40% enhancement in $f\\sigma_8$ compared to $\\Lambda{\\rm CDM}$. The unbiased performance of the clustering wedges model allows us to use the growth rate values estimated from the BOSS LOWZ and CMASS samples to constr...

  9. Structural damage localization by outlier analysis of signal-processed mode shapes - Analytical and experimental validation

    Science.gov (United States)

    Ulriksen, M. D.; Damkilde, L.

    2016-02-01

    Contrary to global modal parameters such as eigenfrequencies, mode shapes inherently provide structural information on a local level. Therefore, this particular modal parameter and its derivatives are utilized extensively for damage identification. Typically, more or less advanced mathematical methods are employed to identify damage-induced discontinuities in the spatial mode shape signals, hereby, potentially, facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement noise. In the present paper, a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement noise is proposed. The method is based on signal processing of a spatial mode shape by means of continuous wavelet transformation (CWT) and subsequent application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact damage-induced, outlier analysis is conducted by applying the Mahalanobis metric to major principal scores of the sensor-located bands of the signal-processed mode shape. The method is tested analytically and benchmarked with other mode shape-based damage localization approaches on the basis of a free-vibrating beam and validated experimentally in the context of a residential-sized wind turbine blade subjected to an impulse load.

  10. Calibration and validation of FLFArs -- a new flood loss function for Australian residential structures

    Science.gov (United States)

    Hasanzadeh Nafari, R.; Ngo, T.; Lehman, W.

    2016-01-01

    Rapid urbanisation, climate change and unsustainable developments are increasing the risk of floods. Flood is a frequent natural hazard that has significant financial consequences for Australia. The emergency response system in Australia is very successful and has saved many lives over the years. However, the preparedness for natural disaster impacts in terms of loss reduction and damage mitigation has been less successful. In this paper, a newly derived flood loss function for Australian residential structures (FLFArs) has been presented and calibrated by using historic data collected from an extreme event in Queensland, Australia, that occurred in 2013. Afterwards, the performance of the method developed in this work (contrasted to one Australian model and one model from USA) has been compared with the observed damage data collected from a 2012 flood event in Maranoa, Queensland. Based on this analysis, validation of the selected methodologies has been performed in terms of Australian geographical conditions. Results obtained from the new empirically based function (FLFArs) and the other models indicate that it is apparent that the precision of flood damage models is strongly dependent on selected stage damage curves, and flood damage estimation without model calibration might result in inaccurate predictions of losses. Therefore, it is very important to be aware of the associated uncertainties in flood risk assessment, especially if models have not been calibrated with real damage data.

  11. Energetics of nonpolar and polar compounds in cationic, anionic, and nonionic micelles studied by all-atom molecular dynamics simulation combined with a theory of solutions.

    Science.gov (United States)

    Date, Atsushi; Ishizuka, Ryosuke; Matubayasi, Nobuyuki

    2016-05-21

    Energetic analysis was conducted for nonpolar and polar solutes bound in a cationic micelle of dodecyl trimethyl ammonium bromide (DTAB), an anionic micelle of sodium dodecyl sulfate (SDS), and a nonionic micelle of tetraethylene glycol monododecyl ether (Brij30). All-atom molecular dynamics simulation was performed, and the free energies of binding the solutes in the hydrophobic-core and headgroup regions of the micelles were computed using the energy-representation method. It was found in all the micelles examined that aromatic naphthalene is preferably located more outward than aliphatic propane and that the polar solutes are localized at the interface of the hydrophobic and hydrophilic regions. The roles of the surfactant and water were then elucidated by decomposing the free energy into the contributions from the respective species. Water was observed to play a decisive role in determining the binding location of the solute, while the surfactant was found to be more important for the overall stabilization of the solute within the micelle. The effects of attractive and repulsive interactions of the solute with the surfactant and water were further examined, and their competition was analyzed in connection with the preferable location of the solute in the micellar system. PMID:27117093

  12. $C_6$ coefficients and dipole polarizabilities for all atoms and many ions in rows 1-6 of the periodic table

    CERN Document Server

    Gould, Tim

    2016-01-01

    Using time-dependent density functional theory (tdDFT) with exchange kernels we calculate and test imaginary frequency-dependent dipole polarizabilities for all atoms and many ns in rows 1-6 of the periodic table. These are then integrated over frequency to produce $C_6$ coefficients. Results are presented under different models: straight tdDFT calculations using two different kernels, "benchmark" tdDFT calculations corrected by more accurate quantum chemical and experimental data, and "benchmark" tdDFT with frozen orbital anions. Parametrisations are presented for 411+ atoms and ions, allowing results to be easily used by other researchers. A curious relationship, $C_{6,XY}\\propto [\\alpha_X(0)\\alpha_Y(0)]^{0.73}$ is found between $C_6$ coefficients and static polarizabilities $\\alpha(0)$. The relationship $C_{6,XY}=2C_{6,X}C_{6,Y}/[\\alpha_X/\\alpha_YC_{6,Y}+\\alpha_Y/\\alpha_XC_{6,X}]$ is tested and found to work well ($30$\\% errors) in a small fraction of cases.

  13. The Strengths and Difficulties Questionnaire (SDQ): The Factor Structure and Scale Validation in U.S. Adolescents

    Science.gov (United States)

    He, Jian-Ping; Burstein, Marcy; Schmitz, Anja; Merikangas, Kathleen R.

    2013-01-01

    The Strengths and Difficulties Questionnaire (SDQ) is one of the most commonly used instruments for screening psychopathology in children and adolescents. This study evaluated the hypothesized five-factor structure of the SDQ and examined its convergent validity against comprehensive clinical diagnostic assessments. Data were derived from the…

  14. Using Structural Equation Modeling to Validate Online Game Players' Motivations Relative to Self-Concept and Life Adaptation

    Science.gov (United States)

    Yang, Shu Ching; Huang, Chiao Ling

    2013-01-01

    This study aimed to validate a systematic instrument to measure online players' motivations for playing online games (MPOG) and examine how the interplay of differential motivations impacts young gamers' self-concept and life adaptation. Confirmatory factor analysis determined that a hierarchical model with a two-factor structure of…

  15. Reliability and content validity of the Disability Assessment Structured Interview (DASI): A tool to assess functional limitations in claimants

    OpenAIRE

    Spanjer, Jerry; Krol, Boudien; Brouwer, Sandra; Popping, R.; Groothoff, J. W.; van der Klink, J. J. L.

    2010-01-01

    Objective The aim of this study is to investigate the reliability and validity of the Disability Assessment Structured Interview (DASI). The DASI is a semi-structured interview for assessing long-term functional limitations concerning the work disability assessment of claimants. Methods A randomized controlled trial was conducted. Patients applying for a work-disability pension after 21 months of sick leave were independently interviewed and examined either by two physicians who had completed...

  16. Examining the Structural Validity of the Strengths and Difficulties Questionnaire (SDQ) in a U.S. Sample of Custodial Grandmothers

    OpenAIRE

    Palmieri, Patrick A.; Smith, Gregory C.

    2007-01-01

    The authors examined the structural validity of the parent informant version of the Strengths and Difficulties Questionnaire (SDQ) with a sample of 733 custodial grandparents. Three models of the SDQ’s factor structure were evaluated with confirmatory factor analysis based on the item covariance matrix. Although indices of fit were good across all 3 models, a model that included a newly hypothesized positive construal method factor in addition to the 4 symptom factors (Emotional Symptoms, Con...

  17. Convergence among Data Sources, Response Bias, and Reliability and Validity of a Structured Job Analysis Questionnaire.

    Science.gov (United States)

    Smith, Jack E.; Hakel, Milton D.

    1979-01-01

    Examined are questions pertinent to the use of the Position Analysis Questionnaire: Who can use the PAQ reliably and validly? Must one rely on trained job analysts? Can people having no direct contact with the job use the PAQ reliably and validly? Do response biases influence PAQ responses? (Author/KC)

  18. The Validity of Games.

    Science.gov (United States)

    Peters, Vincent; Vissers, Geert; Heijne, Gerton

    1998-01-01

    Explores the concept of validity in relation to games and simulations, including four aspects of validity that apply to simulations and games (psychological reality, structural validity, process validity, and predictive validity). Factors that may threaten validity during game design are discussed, and suggestions are made to avert these threats.…

  19. Structure and validity of Family Harmony Scale: An instrument for measuring harmony.

    Science.gov (United States)

    Kavikondala, Sushma; Stewart, Sunita M; Ni, Michael Y; Chan, Brandford H Y; Lee, Paul H; Li, Kin-Kit; McDowell, Ian; Johnston, Janice M; Chan, Sophia S; Lam, T H; Lam, Wendy W T; Fielding, Richard; Leung, Gabriel M

    2016-03-01

    Culture plays a role in mental health, partly by defining the characteristics that are indicative of positive adjustment. In Chinese cultures, positive family relationships are considered central to well-being. The culturally emphasized characteristic of family harmony may be an important factor associated with psychopathology. This article presents the development and psychometric examination of the Family Harmony Scale (FHS), an indigenously developed 24-item instrument tapping family harmony in 17,461 Hong Kong residents from 7,791 households. A higher-order model with 1 second-order factor and 5 first-order factors fit the data well and showed factorial invariance across sex and participants in different family roles. A 5-item short form (FHS-5) was also developed, with 1 item from each first-order factor. The short scale showed, as expected, a single-factor structure with good fit. Both scales demonstrated high internal consistency, acceptable test-retest reliability, and good convergent and discriminant validity. The 24-item FHS was negatively associated with depressive symptoms after accounting for individual risk factors and general family function. Family harmony moderated the relationship between life stress and depressive symptoms such that those individuals who reported low family harmony had stronger associations between life stress and depressive symptoms. This study adds to the literature a systematically developed, multidimensional measure of family harmony, which may be an important psychological protective factor, in a large urban Chinese sample. The FHS-5 minimizes operational and respondent burdens, making it an attractive tool for large-scale epidemiological studies with Chinese populations in urban settings, where over half of China's 1.4 billion people reside. PMID:26146946

  20. AOCS Performance and Stability Validation for a 160-m Solar Sail with Control-Structure Interactions

    Science.gov (United States)

    Wie, Bong; Murphy, David

    2005-01-01

    Future solar sail missions, such as NASA's Solar Polar Imager Vision, will require sails with dimensions on the order of 50-500 m. We are examining a square sail design with moving mass (trim control mass, TCM) and quadrant rotation primary actuators plus pulsed plasma thrusters (PPTs) at the mast tips for backup attitude control. Quadrant rotation is achieved via roll stabilizer bars (RSB) at the mast tips. At these sizes, given the gossamer nature of the sail supporting structures, flexible modes may be low enough to interact with the control system, especially as these actuators are located on the flexible structure itself and not on the rigid core. This paper develops a practical analysis of the flexible interactions using state-space systems and modal data from finite element models of the system. Torsion and bending of the masts during maneuvers could significantly affect the function of the actuators while activation of the membrane modes could adversely affect the thrust vector direction and magnitude. Analysis of the RSB and TCM dynamics for developing high-fidelity simulations is included. For control analysis of the flexible system, standard finite-element models of the flexible sail body are loaded and the modal data is used to create a modal coordinate state-space system. Key parameters include which modes to include, which nodes are of interest for force inputs and displacement outputs, connecting nodes through which external forces and torques are applied from the flex body to the core, any nominal momentum in the system, and any steady rates. The system is linearized about the nominal attitude and rate. The state-space plant can then be analyzed with a state-space controller, and Bode, Nyquist, step and impulse responses generated. The approach is general for any rigid core with a flexible appendage. This paper develops a compensator for a simple two-mass flex system and extrapolates the results to the solar sail. A finite element model of the 20 m

  1. On-orbit validation system for space structure composite actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project delivers an On-orbit Validation System (OVS) that provides performance and durability data for Macro Fiber Composite (MFC) active piezocomposite...

  2. Validity, Reliability, and Factor Structure of Carver, Scheier and Weinteraub's Coping Operations Preference Enquiry (COPE in University of Isfahan Students

    Directory of Open Access Journals (Sweden)

    *R. Jalalinejad

    2014-11-01

    Full Text Available The purpose of this research was to determine validity, reliability and factor structure of Coping Preference Enquiry. Therefore a group of 240 Universit of Isfahan students (168 females and 72 males were randomly selected as the statistical sample. The instrument of the research was Carver, Scheier and Weinterub's Coping Preference Enquiry. To assess reliability, Chronbach's alpha was computed, and to assess construct validity, exploratory factor analysis and the item-total correlation within each subscale was calculated. Using varimax rotation five factors were obtained which were named: 1 cognitive- approach coping 2 behavioral- approach coping 3 emotional- approach coping 4 cognitive- avoidance coping 5 behavioral- avoidance coping. Overall, the results showed the above validity and reliability in the population of the students of Isfahan University.

  3. Generation and structural validation of a library of diverse xyloglucan-derived oligosaccharides, including an update on xyloglucan nomenclature.

    Science.gov (United States)

    Tuomivaara, Sami T; Yaoi, Katsuro; O'Neill, Malcolm A; York, William S

    2015-01-30

    Xyloglucans are structurally complex plant cell wall polysaccharides that are involved in cell growth and expansion, energy metabolism, and signaling. Determining the structure-function relationships of xyloglucans would benefit from the availability of a comprehensive and structurally diverse collection of rigorously characterized xyloglucan oligosaccharides. Here, we present a workflow for the semi-preparative scale generation and purification of neutral and acidic xyloglucan oligosaccharides using a combination of enzymatic and chemical treatments and size-exclusion chromatography. Twenty-six of these oligosaccharides were purified to near homogeneity and their structures validated using a combination of matrix-assisted laser desorption/ionization mass spectrometry, high-performance anion exchange chromatography, and 1H nuclear magnetic resonance spectroscopy. Mass spectrometry and analytical chromatography were compared as methods for xyloglucan oligosaccharide quantification. 1H chemical shifts were assigned using two-dimensional correlation spectroscopy. A comprehensive update of the nomenclature describing xyloglucan side-chain structures is provided for reference. PMID:25497333

  4. Validation of molecular crystal structures from powder diffraction data with dispersion-corrected density functional theory (DFT-D)

    International Nuclear Information System (INIS)

    The accuracy of 215 experimental organic crystal structures from powder diffraction data is validated against a dispersion-corrected density functional theory method. In 2010 we energy-minimized 225 high-quality single-crystal (SX) structures with dispersion-corrected density functional theory (DFT-D) to establish a quantitative benchmark. For the current paper, 215 organic crystal structures determined from X-ray powder diffraction (XRPD) data and published in an IUCr journal were energy-minimized with DFT-D and compared to the SX benchmark. The on average slightly less accurate atomic coordinates of XRPD structures do lead to systematically higher root mean square Cartesian displacement (RMSCD) values upon energy minimization than for SX structures, but the RMSCD value is still a good indicator for the detection of structures that deserve a closer look. The upper RMSCD limit for a correct structure must be increased from 0.25 Å for SX structures to 0.35 Å for XRPD structures; the grey area must be extended from 0.30 to 0.40 Å. Based on the energy minimizations, three structures are re-refined to give more precise atomic coordinates. For six structures our calculations provide the missing positions for the H atoms, for five structures they provide corrected positions for some H atoms. Seven crystal structures showed a minor error for a non-H atom. For five structures the energy minimizations suggest a higher space-group symmetry. For the 225 SX structures, the only deviations observed upon energy minimization were three minor H-atom related issues. Preferred orientation is the most important cause of problems. A preferred-orientation correction is the only correction where the experimental data are modified to fit the model. We conclude that molecular crystal structures determined from powder diffraction data that are published in IUCr journals are of high quality, with less than 4% containing an error in a non-H atom

  5. Validity and reliability of the structured clinical interview for the trauma and loss spectrum (SCI-TALS)

    OpenAIRE

    Conversano Ciro; Perris Francesco; Carpiniello Bernardo; Altamura A Carlo; Endicott Jean; Lorettu Liliana; Frank Ellen; Maser Jack D; Rucci Paola; Carmassi Claudia; Shear M Katherine; dell'Osso Liliana; Ciapparelli Antonio; Carlini Marina; Sarno Nannina

    2008-01-01

    Abstract Background DSM-IV identifies three stress response disorders (acute stress Disorder (ASD), post-traumatic stress Disorder (PTSD) and adjustment disorders (AD)) that derive from specific life events. An additional condition of complicated grief (CG), well described in the literature, is triggered by bereavement. This paper reports on the reliability and validity of the Structured Clinical Interview for Trauma and Loss Spectrum (SCI-TALS) developed to assess the spectrum of stress resp...

  6. Psychometric Validation of the Korean Version of Structured Interview for Post-traumatic Stress Disorder (K-SIP)

    OpenAIRE

    Kim, Won; Kim, Daeho; Seo, Ho-Jun; Lee, Sang-Yeol; Ryu, Seung-Ho; Kim, Jung-Bum; Chung, Moon Yong; Koo, Young Jin; Ryu, Seong Gon; Kim, Eui Jung; Kim, Tae-Suk; Lim, Hyun-Kook; Woo, Jong-Min; Chae, Jeong-Ho; ,

    2009-01-01

    For diagnosis and management of post-traumatic stress disorder (PTSD), the easily administered assessment tool is essential. Structured Interview for PTSD (SIP) is a validated, 17-item, simple measurement being used widely. We aimed to develop the Korean version of SIP (K-SIP) and investigated its psychometric properties. Ninety-three subjects with PTSD, 73 subjects with mood disorder or anxiety disorder as a psychiatric control group, and 88 subjects as a healthy control group were enrolled ...

  7. Development of the clinical learning evaluation questionnaire for undergraduate clinical education: Factor structure, validity, and reliability study

    OpenAIRE

    AlHaqwi, Ali I; Kuntze, Jeroen; van der Molen, Henk

    2014-01-01

    textabstractBackground: Teaching and learning of clinical skills for undergraduate medical students usually takes place during the clinical clerkship. Therefore, it is of vital importance to ensure the effectiveness of the rotations within this clerkship. The aims of this study were to develop an instrument that measures the effectiveness of the clinical learning environment, to determine its factor structure, and to find first evidence for the reliability and validity of the total scale and ...

  8. A Quantitative Structure Activity Relationship for acute oral toxicity of pesticides on rats: Validation, Domain of Application and Prediction

    OpenAIRE

    Hamadache, Mabrouk; Benkortbi, Othmane; Hanini, Salah; Amrane, Abdeltif; Khaouane, Latifa; Si Moussa, Cherif

    2016-01-01

    International audience Quantitative Structure Activity Relationship (QSAR) models are expected to play an important role in the risk assessment of chemicals on humans and the environment. In this study, we developed a validated QSAR model to predict acute oral toxicity of 329 pesticides to rats because a few QSAR models have been devoted to predict the Lethal Dose 50 (LD50) of pesticides on rats. This QSAR model is based on 17 molecular descriptors, and is robust, externally predictive and...

  9. The DUNDRUM-1 structured professional judgment for triage to appropriate levels of therapeutic security: retrospective-cohort validation study.

    LENUS (Irish Health Repository)

    Flynn, Grainne

    2011-01-01

    The assessment of those presenting to prison in-reach and court diversion services and those referred for admission to mental health services is a triage decision, allocating the patient to the appropriate level of therapeutic security. This is a critical clinical decision. We set out to improve on unstructured clinical judgement. We collated qualitative information and devised an 11 item structured professional judgment instrument for this purpose then tested for validity.

  10. Validation of standardized and structured EHR data in the dual model approach.

    Science.gov (United States)

    Rinner, Christoph; Duftschmid, Georg

    2009-01-01

    We present a W3C XML Schema-based method to validate standardized EHR data against semantic constraints that build the knowledge layer within the dual model approach. The approach was tested with three EN/ISO13606 archetypes and an HL7 CDA implementation guide for diabetes therapies. PMID:19745278

  11. Age Differences in Personality Structure Revisited: Studies in Validity, Stability, and Change

    Science.gov (United States)

    Costa, Paul T., Jr.; McCrae, Robert R.

    1978-01-01

    Construct validity and longitudinal stability evidence for three cluster dimensions of personality identified as Anxiety, Extraversion, and Openness is examined in a sample of adult males. Correlations with Allport-Vernon-Lindsay Value scales, Cornell Medical Index scores, Eysenck E and N scales, and factors from the SVIB are presented. (Author)

  12. Construct validity and reliability of structured assessment of endovascular expertise in a simulated setting

    DEFF Research Database (Denmark)

    Bech, B.; Lönn, L.; Falkenberg, M.; Bartholdy, N. J.; Räder, S. B.; Schroeder, T. V.; Ringsted, Charlotte

    2011-01-01

    clinical experience (R = -0.53, P < 0.05), whereas the fluoroscopy time and amount of contrast fluid did not correlate. Conclusions The construct validity and reliability of assessment with the SAVE scale was high when applied to performances in a simulation setting with advanced realism. No ceiling effect...

  13. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Science.gov (United States)

    Pereira, G F; Mikkelsen, L P; McGugan, M

    2015-01-01

    In a fibre-reinforced polymer (FRP) structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP), the structural health monitoring technology (fibre Bragg gratings to detect delamination), and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor) was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model. PMID:26513653

  14. Validation of Structural Parameters As Damage Indicators for Monitoring Plates in the Post Buckling Regime

    OpenAIRE

    Viechtbauer, Christoph; Schagerl, Martin; Schröder, Kai-Uwe

    2014-01-01

    The Structural Health Control (SHC) concept is a novel and overarching approach to monitor the strength of a structure online and in realtime over its lifecycle. In the center of the SHC approach is the structural analysis of the monitored part. It provides the information to identify structural parameters as damage indicators. With this information an optimized sensor layout can be defined to monitor the damage indicators in a smart way. The monitoring system is therefore referred as SmartSH...

  15. Latent structure of the French Validation of the Ambivalent Sexism Inventory: Echelle de Sexisme Ambivalent

    OpenAIRE

    Dardenne, Benoît; Delacollette, Nathalie; Grégoire, Christine; Lecocq, Delphine

    2006-01-01

    Glick and Fiske's (1996) Ambivalent Sexism Inventory is a measure of hostile sexism (sexist antipathy) and benevolent sexism (a subjectively positive attitude toward women). This paper proposes a French version of this scale, the Echelle de Sexisme Ambivalent (ESA). Three studies on more than 1000 participants established the validity of this new scale. The first one is the application of Rasch's extended model that confirmed the psychometrical qualities of the ESA, for both male and female p...

  16. Structural characterization of low level degradants in aztreonam injection and an innovative approach to aid HPLC method validation.

    Science.gov (United States)

    Ye, Qingmei; Ding, Wei; Rinaldi, Frank; Huang, Yande; Miller, Scott A; Bolgar, Mark

    2016-05-30

    Three new degradants have been identified from drug product and active pharmaceutical ingredient stability samples of aztreonam, a marketed synthetic monocyclic beta-lactam antibiotic. The degradants were detected following the implementation of a new, more selective HPLC method for the determination of impurities and degradants. The new method was developed in response to changes in the regulatory requirement for mature products. Two of the new unknown Degradants (I and II) were observed in chromatograms from stability samples of aztreonam injection. The third new Degradant (III) was observed during a stability study of the aztreonam active pharmaceutical ingredient. These degradants were structurally characterized. A small amount (ca. 1-3mg) of each degradant was isolated via preparative HPLC for structure elucidation using accurate MS, one and two-dimensional NMR spectroscopy. The small amount of each NMR sample was then reused as a standard for HPLC purity/impurity method validation. Their exact concentrations were determined using quantitative NMR which enabled the execution of the quantitative elements of the HPLC method validation. This innovative approach eliminated the need to isolate or synthesize larger quantities of markers for HPLC/UV method validation, thus saving significant time and reducing costs. PMID:26991056

  17. Finite element model validation of bridge based on structural health monitoring—Part I: Response surface-based finite element model updating

    OpenAIRE

    Zhouhong Zong; Xiaosong Lin; Jie Niu

    2015-01-01

    In the engineering practice, merging statistical analysis into structural evaluation and assessment is a tendency in the future. As a combination of mathematical and statistical techniques, response surface (RS) methodology has been successfully applied to design optimization, response prediction and model validation. With the aid of RS methodology, these two serial papers present a finite element (FE) model updating and validation method for bridge structures based on structural health monit...

  18. Structural Design of the DTU-ESA MM-Wave Validation Standard Antenna

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter; Markussen, Christen Malte; Kim, Oleksiy S.; Jørgensen, R.; Pivnenko, Sergey; Breinbjerg, Olav

    2015-01-01

    A new specially designed antenna to be used for inter-comparisons and validation of antenna test facilities is under development in cooperation between DTU and TICRA under a contract from the European Space Agency. The antenna is designed to be extremely thermally and mechanically stable in the...... using the commercial finite element package MSC.Patran with MSC.MARC as solver. The solid parts of the antenna are meshed with 10-noded tetrahedral elements, which have quadratic shape functions and the entire model has approximately 325.000 elements. The individual solid part of the antenna is...

  19. The factorial structure and validity of the Hospital Anxiety and Depression Scale (HADS in Polish adolescents

    Directory of Open Access Journals (Sweden)

    Andreea Mihaela Mihalca

    2015-10-01

    The issues concerned with the factorial structure of HADS are replicated in Polish adolescents as well. HADS-Teen shows different structures in chronically ill versus healthy adolescents. Results indicate that a special attention must be paid when assessing depression symptoms in healthy adolescents using this instrument.

  20. Validation and Optimization of a Design Formula for Stable Geometrically Open Filter Structures

    NARCIS (Netherlands)

    Van de Sande, S.A.H.; Uijttewaal, W.S.J.; Verheij, H.J.

    2014-01-01

    Granular filters are used for protection against scour and erosion of base material. For a proper functioning it is necessary that at the interfaces between the filter structure, the subsoil and the water flowing above the filter structure no material will be transported. Different types of granular

  1. Guessing unknown and disordered solvent molecules with squeeze in the structure validation platon

    International Nuclear Information System (INIS)

    This report describes the assignment of the nature and number of solvent molecules in the refinement of several solvated crystal structures without a prior knowledge of the solvent system used for crystallization for the cases when the solvent molecule cannot be properly modeled. The solvent molecules can be assigned even for twinned crystal structures. (author)

  2. Verification and Validation of Numerical Models for Air/Water Flow on Coastal and Navigation Fluid-Structure Interaction Applications

    Science.gov (United States)

    Kees, C. E.; Farthing, M.; Dimakopoulos, A.; DeLataillade, T.

    2015-12-01

    Performance analysis and optimization of coastal and navigation structures is becoming feasible due to recent improvements in numerical methods for multiphase flows and the steady increase in capacity and availability of high performance computing resources. Now that the concept of fully three-dimensional air/water flow modelling for real world engineering analysis is achieving acceptance by the wider engineering community, it is critical to expand careful comparative studies on verification,validation, benchmarking, and uncertainty quantification for the variety of competing numerical methods that are continuing to evolve. Furthermore, uncertainty still remains about the relevance of secondary processes such as surface tension, air compressibility, air entrainment, and solid phase (structure) modelling so that questions about continuum mechanical theory and mathematical analysis of multiphase flow are still required. Two of the most popular and practical numerical approaches for large-scale engineering analysis are the Volume-Of-Fluid (VOF) and Level Set (LS) approaches. In this work we will present a publically available verification and validation test set for air-water-structure interaction problems as well as computational and physical model results including a hybrid VOF-LS method, traditional VOF methods, and Smoothed Particle Hydrodynamics (SPH) results. The test set repository and test problem formats will also be presented in order to facilitate future comparative studies and reproduction of scientific results.

  3. Damage detection in composite structures using autonomous wireless systems: simulation and validation

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, D; Lani, F [Cenaero, Centre de Recherche en Aeronautique, 29 Rue des freres Wright, B-6041 Gosselies (Belgium); Monnier, T [Universite de Lyon, INSA-Lyon, F-69621, Villeurbanne cedex (France); Smaili, R; Loyer, J, E-mail: david.dumas@cenaero.be [GOODRICH Actuation Systems, 106 Rue Fourny, F-78530, Buc (France)

    2011-07-19

    In the European FP6 project ADVICE, units that harvest energy from structural vibrations have been developed. These autonomous units are capable of wireless communication and are used as actuators of guided ultrasonic waves used to identify changes in structural behaviour. The growing use of composite structures in aeronautics brings new challenges to be able to predict and detect damage that may occur in these new materials. Part of the ADVICE project focused on studying the possibilities of damage detection in structures using Lamb waves. In order to do this, finite element simulations were performed and were compared with experimental data. This paper presents the finite element simulations performed to predict the behaviour of a structural health monitoring system. Using the technique and algorithms developed to quantify the amount of damage, we compare the numerical results to those that were obtained experimentally on a small representative composite structure. This allows evaluating how it is possible to design a monitoring system for composite structures and what needs to be addressed in the future.

  4. Damage detection in composite structures using autonomous wireless systems: simulation and validation

    International Nuclear Information System (INIS)

    In the European FP6 project ADVICE, units that harvest energy from structural vibrations have been developed. These autonomous units are capable of wireless communication and are used as actuators of guided ultrasonic waves used to identify changes in structural behaviour. The growing use of composite structures in aeronautics brings new challenges to be able to predict and detect damage that may occur in these new materials. Part of the ADVICE project focused on studying the possibilities of damage detection in structures using Lamb waves. In order to do this, finite element simulations were performed and were compared with experimental data. This paper presents the finite element simulations performed to predict the behaviour of a structural health monitoring system. Using the technique and algorithms developed to quantify the amount of damage, we compare the numerical results to those that were obtained experimentally on a small representative composite structure. This allows evaluating how it is possible to design a monitoring system for composite structures and what needs to be addressed in the future.

  5. Design and validation of wireless acceleration sensor network for structural health monitoring

    Institute of Scientific and Technical Information of China (English)

    Yu Yan; Ou Jinping

    2006-01-01

    A wireless sensor network is proposed to monitor the acceleration of structures for the purpose of structural health monitoring of civil engineering structures. Using commercially available parts, several modules are constructed and integrated into complete wireless sensors and base stations. The communication protocol is designed and the fusion arithmetic of the temperature and acceleration is embedded in the wireless sensor node so that the measured acceleration values are more accurate. Measures are adopted to finish energy optimization, which is an important issue for a wireless sensor network. The test is performed on an offshore platform model, and the experimental results are given to show the feasibility of the designed wireless sensor network.

  6. Validity and reliability of the Structured Clinical Interview for the Trauma and Loss Spectrum (SCI-TALS

    Directory of Open Access Journals (Sweden)

    Conversano Ciro

    2008-01-01

    Full Text Available Abstract Background DSM-IV identifies three stress response disorders (acute stress Disorder (ASD, post-traumatic stress Disorder (PTSD and adjustment disorders (AD that derive from specific life events. An additional condition of complicated grief (CG, well described in the literature, is triggered by bereavement. This paper reports on the reliability and validity of the Structured Clinical Interview for Trauma and Loss Spectrum (SCI-TALS developed to assess the spectrum of stress response. The instrument is based on a spectrum model that emphasizes soft signs, low-grade symptoms, subthreshold syndromes, as well as temperamental and personality traits comprising clinical and subsyndromal manifestations. Methods Study participants, enrolled at 6 Italian Departments of Psychiatry located at six sites, included consecutive patients with PTSD, 44 with CG and a comparative group of 48 unselected controls. Results We showed good reliability and validity of the SCI-TALS. Domain scores were significantly higher in participants with PTSD or CG compared to controls. There were high correlations between specific SCI-TALS domains and corresponding scores on established measures of similar constructs. Participants endorsing grief and loss events reported similar scores on all instruments, except those with CG who scored significantly higher on the domain of grief reactions. Conclusion These findings provide strong support for the internal consistency, the discriminant validity and the reliability of the SCI-TALS. These results also support the existence of a specific grief-related condition and the proposal that different forms of stress response have similar manifestations.

  7. THE SPANISH VERSION OF THE CRIMINAL SENTIMENT SCALE MODIFIED (CSS-M: FACTOR STRUCTURE, RELIABILITY, AND VALIDITY

    Directory of Open Access Journals (Sweden)

    Víctor Company Martínez

    2015-07-01

    Full Text Available The purpose of this study was to translate and validate the Criminal Sentiment Scale Modified (CSS-M, which measures the criminal attitudes into Spanish. Despite the large body of research proving their importance as one of the best predictors of criminal conduct, only a few measures have been psychometrically developed and validated, and none of them are available in the Spanish language. A sample of 153 male inmates from Penitentiary Brians I of the Catalan Prison Service (Spain participated voluntarily in the study (73.9% of Spanish nationality, mean age = 37.3 completed the final version of the Spanish adaptation. An exploratory factor analysis (EFA and a confirmatory factor analysis (CFA were conducted with all the scales simultaneously, showing that the underlying structure of the CSS-M was best explained by a two-factor solution: Sentiments toward the establishment and Criminality self-benefits. Moreover, a set of analyses of variance (ANOVA was also performed, validating the scale well. According to the results of the study, it was concluded that the Spanish version of the CSS-M has satisfactory psychometric properties, enabling its potential usefulness within the legal field of Spanish-speaking countries as a key element in crime prevention.

  8. A Quantitative Structure Activity Relationship for acute oral toxicity of pesticides on rats: Validation, domain of application and prediction.

    Science.gov (United States)

    Hamadache, Mabrouk; Benkortbi, Othmane; Hanini, Salah; Amrane, Abdeltif; Khaouane, Latifa; Si Moussa, Cherif

    2016-02-13

    Quantitative Structure Activity Relationship (QSAR) models are expected to play an important role in the risk assessment of chemicals on humans and the environment. In this study, we developed a validated QSAR model to predict acute oral toxicity of 329 pesticides to rats because a few QSAR models have been devoted to predict the Lethal Dose 50 (LD50) of pesticides on rats. This QSAR model is based on 17 molecular descriptors, and is robust, externally predictive and characterized by a good applicability domain. The best results were obtained with a 17/9/1 Artificial Neural Network model trained with the Quasi Newton back propagation (BFGS) algorithm. The prediction accuracy for the external validation set was estimated by the Q(2)ext and the root mean square error (RMS) which are equal to 0.948 and 0.201, respectively. 98.6% of external validation set is correctly predicted and the present model proved to be superior to models previously published. Accordingly, the model developed in this study provides excellent predictions and can be used to predict the acute oral toxicity of pesticides, particularly for those that have not been tested as well as new pesticides. PMID:26513561

  9. Validation of Wing Deformation Simulations for the NASA CRM Model using Fluid-Structure Interaction Computations

    OpenAIRE

    Keye, Stefan; Rudnik, Ralf

    2015-01-01

    The virtual determination of static aeroelastic deformations of NASA’s Common Research Model at steady-state flow conditions is described. Aeroelastic equilibrium conditions are computed using a fluid-structure interaction simulation approach based on high-fidelity numerical fluid dynamics and structural analysis methods. The correlation of numerical and experimental results under varying aerodynamic loads and model deformations is investigated and the influence of aeroelastic deformations on wing...

  10. Stress and structural damage sensing piezospectroscopic coatings validated with digital image correlation

    Directory of Open Access Journals (Sweden)

    Gregory Freihofer

    2015-03-01

    Full Text Available The piezospectroscopic effect, relating a material’s stress state and spectral signature, has recently demonstrated tailorable sensitivity when the photo-luminescent alpha alumina is distributed in nanoparticulate form within a matrix. Here, the stress-sensing behavior of an alumina-epoxy nanoparticle coating, applied to a composite substrate in an open hole tension configuration, is validated with the biaxial strain field concurrently determined through digital image correlation. The coating achieved early detection of composite failure initiation at 77% failure load, and subsequently tracked stress distribution in the immediate vicinity of the crack as it progressed, demonstrating non-invasive stress and damage detection with multi-scale spatial resolution.

  11. Prediction and experimental validation of enzyme substrate specificity in protein structures.

    Science.gov (United States)

    Amin, Shivas R; Erdin, Serkan; Ward, R Matthew; Lua, Rhonald C; Lichtarge, Olivier

    2013-11-01

    Structural Genomics aims to elucidate protein structures to identify their functions. Unfortunately, the variation of just a few residues can be enough to alter activity or binding specificity and limit the functional resolution of annotations based on sequence and structure; in enzymes, substrates are especially difficult to predict. Here, large-scale controls and direct experiments show that the local similarity of five or six residues selected because they are evolutionarily important and on the protein surface can suffice to identify an enzyme activity and substrate. A motif of five residues predicted that a previously uncharacterized Silicibacter sp. protein was a carboxylesterase for short fatty acyl chains, similar to hormone-sensitive-lipase-like proteins that share less than 20% sequence identity. Assays and directed mutations confirmed this activity and showed that the motif was essential for catalysis and substrate specificity. We conclude that evolutionary and structural information may be combined on a Structural Genomics scale to create motifs of mixed catalytic and noncatalytic residues that identify enzyme activity and substrate specificity. PMID:24145433

  12. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics.

    Directory of Open Access Journals (Sweden)

    Anders S Christensen

    Full Text Available We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts--sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM calculations and reproduces high level QM results obtained for a small protein with an RMSD of 0.25 ppm (r = 0.94. ProCS is interfaced with the PHAISTOS protein simulation program and is used to infer statistical protein ensembles that reflect experimentally measured amide proton chemical shift values. Such chemical shift-based structural refinements, starting from high-resolution X-ray structures of Protein G, ubiquitin, and SMN Tudor Domain, result in average chemical shifts, hydrogen bond geometries, and trans-hydrogen bond ((h3J(NC' spin-spin coupling constants that are in excellent agreement with experiment. We show that the structural sensitivity of the QM-based amide proton chemical shift predictions is needed to obtain this agreement. The ProCS method thus offers a powerful new tool for refining the structures of hydrogen bonding networks to high accuracy with many potential applications such as protein flexibility in ligand binding.

  13. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics

    CERN Document Server

    Christensen, Anders S; Borg, Mikael; Boomsma, Wouter; Lindorff-Larsen, Kresten; Hamelryck, Thomas; Jensen, Jan H

    2013-01-01

    We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts - sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM) calculations and reproduces high level QM results obtained for a small protein with an RMSD of 0.25 ppm (r = 0.94). ProCS is interfaced with the PHAISTOS protein simulation program and is used to infer statistical protein ensembles that reflect experimentally measured amide proton chemical shift values. Such chemical shift-based structural refinements, starting from high-resolution X-ray structures of Protein G, ubiquitin, and SMN Tudor Domain, result in average chemical shifts, hydrogen bond geometries, and trans-hydrogen bond (h3JNC') spin-spin coupling constants that are in excellent agreement with experiment. We show that the structural sensitivity of the QM-based amide proton chemical shift predictions is needed to refine protein structures to this...

  14. Simulation of High Velocity Impact on Composite Structures - Model Implementation and Validation

    Science.gov (United States)

    Schueler, Dominik; Toso-Pentecôte, Nathalie; Voggenreiter, Heinz

    2016-08-01

    High velocity impact on composite aircraft structures leads to the formation of flexural waves that can cause severe damage to the structure. Damage and failure can occur within the plies and/or in the resin rich interface layers between adjacent plies. In the present paper a modelling methodology is documented that captures intra- and inter-laminar damage and their interrelations by use of shell element layers representing sub-laminates that are connected with cohesive interface layers to simulate delamination. This approach allows the simulation of large structures while still capturing the governing damage mechanisms and their interactions. The paper describes numerical algorithms for the implementation of a Ladevèze continuum damage model for the ply and methods to derive input parameters for the cohesive zone model. By comparison with experimental results from gas gun impact tests the potential and limitations of the modelling approach are discussed.

  15. Code validation for the structural analysis of a subassembly response to pressure transients: Present status and trends

    International Nuclear Information System (INIS)

    Fast reactor safety studies were in a first step devoted to HCDA analysis and led to the evaluation of primary containment behaviour under severe transient dynamic loading. The J.R.C. Ispra has actively participated in a joint European Code Validation Programme and the COVA series of reduced-scale experiments were correspondingly designed in order to represent flow pattern, hydro-structural coupling and wave propagation conditions similar to fast-breeder whole core accident conditions. Now the safety considerations have moved towards the analysis of local events at subassembly level (COVAS). Here the importance of local structural behaviour becomes a key point as far as the development and possible propagation of the accident is concerned. (orig./GL)

  16. Validation of in utero tractography of human fetal commissural and internal capsule fibers with histological structure tensor analysis

    Directory of Open Access Journals (Sweden)

    Christian eMitter

    2015-12-01

    Full Text Available Diffusion tensor imaging (DTI and tractography offer the unique possibility to visualize the developing white matter macroanatomy of the human fetal brain in vivo and in utero and are currently under investigation for their potential use in the diagnosis of developmental pathologies of the human central nervous system. However, in order to establish in utero DTI as a clinical imaging tool, an independent comparison between macroscopic imaging and microscopic histology data in the same subject is needed. The present study aimed to cross-validate normal as well as abnormal in utero tractography results of commissural and internal capsule fibers in human fetal brains using postmortem histological structure tensor (ST analysis. In utero tractography findings from two structurally unremarkable and five abnormal fetal brains were compared to the results of postmortem ST analysis applied to digitalized whole hemisphere sections of the same subjects. An approach to perform ST-based deterministic tractography in histological sections was implemented to overcome limitations in correlating in utero tractography to postmortem histology data. ST analysis and histology-based tractography of fetal brain sections enabled the direct assessment of the anisotropic organization and main fiber orientation of fetal telencephalic layers on a micro- and macroscopic scale, and validated in utero tractography results of corpus callosum and internal capsule fiber tracts. Cross-validation of abnormal in utero tractography results could be achieved in four subjects with agenesis of the corpus callosum and in two cases with malformations of internal capsule fibers. In addition, potential limitations of current DTI-based in utero tractography could be demonstrated in several brain regions. Combining the three-dimensional nature of DTI-based in utero tractography with the microscopic resolution provided by histological ST analysis may ultimately facilitate a more complete

  17. Electro-optic aids to quality assessment (EAQA) and structural validation

    International Nuclear Information System (INIS)

    Electro-optic aids to quality assessment (EAQA) utilize very sensitive full field non-contact, finger printing methods, to visualize discontinuities nd quantify movement and strain in most materials and structures between low nd elevated temperatures. These methods are laser holography, laser speckle photography and infra-red thermoelasticity. The laser techniques involve recording double exposures of objects illuminated with coherent light and the infra-red technique records infra-red radiation emitted from a structure undergoing cyclic loading. The techniques are described

  18. Assessment of the structural validity of the domestic violence healthcare providers’ survey questionnaire using a Nigerian sample

    Directory of Open Access Journals (Sweden)

    Stephen Lawoko

    2010-07-01

    Full Text Available BACKGROUND: There has been increased advocacy to involve healthcare providers in the prevention of intimate partner violence (IPV through screening for it in healthcare. Yet, only one in ten providers screen for IPV, suggesting barriers. Understanding the readiness of healthcare providers to screen for IPV is therefore paramount. The Domestic Violence Healthcare Provider Survey Scales (DVHPSS is a previously validated, comprehensive scale to study readiness of healthcare providers to screen for IPV. However, an understanding of its usefulness in the Sub-Saharan African context remains elusive. The current study undertook to examine the structural validity of the DVHPSS in Nigeria. METHODS: Exploratory factor analysis and Cronbach's Alpha were run to reveal the factorial structure and reliability of the instrument/subscales respectively. Established thresholds were used to determine significant factor loadings and alphas coefficient. RESULTS: A six factor model emerged, with 2 factors similar to the original scale, another two differing slightly and a further two factors resulting from a splitting up of the original combination of victim/provider safety to having distinct victim and provider safety subscales. CONCLUSIONS: With slight modifications, the DVHPSS can be use to study IPV screening among Nigerian healthcare professionals. Introducing screening protocols could promote better understanding of crucial questions that were lost in the analysis.

  19. Brazilian version of the Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R: adaptation and validation process

    Directory of Open Access Journals (Sweden)

    Jessica Camargo

    2013-12-01

    Full Text Available BACKGROUND: Posttraumatic stress disorder (PTSD contemplates the impact of acute traumatic events, but the literature indicates that this is not true for chronic exposure to stress. In this sense, the category disorders of extreme stress not otherwise specified (DESNOS has been proposed to characterize the behavior and cognitive alterations derived from exposure to continuous early life stress. The Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R was developed to investigate and measure DESNOS. Considering the lack of instruments designed to assess DESNOS, especially in Brazil, the aim of this study was to translate, adapt, and validate the contents of SIDES-R to Brazilian Portuguese (SIDES-R-BR. METHOD: The original interview was subjected to translation, back-translation, semantic equivalence and conceptual correspondence analyses by naive and specialized judges, respectively, an acceptability trial, and inter-rater validity analysis. RESULTS: The interview underwent semantic and structural adaptations considering the Brazilian culture. The final version, SIDES-R-BR, showed a mean understanding score of 4.98 on a 5-point verbal rating scale, in addition to a kappa coefficient of 0.853. CONCLUSION: SIDES-R-BR may be a useful tool in the investigation of DESNOS and contributes a valuable input to clinical research in Brazil. The availability of the instrument allows to test symptoms with adequate reliability, as verified by the kappa coefficient and translation steps.

  20. Damage tolerance modeling and validation of a wireless sensory composite panel for a structural health monitoring system

    Science.gov (United States)

    Talagani, Mohamad R.; Abdi, Frank; Saravanos, Dimitris; Chrysohoidis, Nikos; Nikbin, Kamran; Ragalini, Rose; Rodov, Irena

    2013-05-01

    The paper proposes the diagnostic and prognostic modeling and test validation of a Wireless Integrated Strain Monitoring and Simulation System (WISMOS). The effort verifies a hardware and web based software tool that is able to evaluate and optimize sensorized aerospace composite structures for the purpose of Structural Health Monitoring (SHM). The tool is an extension of an existing suite of an SHM system, based on a diagnostic-prognostic system (DPS) methodology. The goal of the extended SHM-DPS is to apply multi-scale nonlinear physics-based Progressive Failure analyses to the "as-is" structural configuration to determine residual strength, remaining service life, and future inspection intervals and maintenance procedures. The DPS solution meets the JTI Green Regional Aircraft (GRA) goals towards low weight, durable and reliable commercial aircraft. It will take advantage of the currently developed methodologies within the European Clean sky JTI project WISMOS, with the capability to transmit, store and process strain data from a network of wireless sensors (e.g. strain gages, FBGA) and utilize a DPS-based methodology, based on multi scale progressive failure analysis (MS-PFA), to determine structural health and to advice with respect to condition based inspection and maintenance. As part of the validation of the Diagnostic and prognostic system, Carbon/Epoxy ASTM coupons were fabricated and tested to extract the mechanical properties. Subsequently two composite stiffened panels were manufactured, instrumented and tested under compressive loading: 1) an undamaged stiffened buckling panel; and 2) a damaged stiffened buckling panel including an initial diamond cut. Next numerical Finite element models of the two panels were developed and analyzed under test conditions using Multi-Scale Progressive Failure Analysis (an extension of FEM) to evaluate the damage/fracture evolution process, as well as the identification of contributing failure modes. The comparisons

  1. Discriminant and concurrent validity of a simplified DSM-based structured diagnostic instrument for the assessment of autism spectrum disorders in youth and young adults

    Directory of Open Access Journals (Sweden)

    Joshi Gagan

    2011-12-01

    Full Text Available Abstract Background To evaluate the concurrent and discriminant validity of a brief DSM-based structured diagnostic interview for referred individuals with autism spectrum disorders (ASDs. Methods To test concurrent validity, we assessed the structured interview's agreement in 123 youth with the expert clinician assessment and the Social Responsiveness Scale (SRS. Discriminant validity was examined using 1563 clinic-referred youth. Results The structured diagnostic interview and SRS were highly sensitive indicators of the expert clinician assessment. Equally strong was the agreement between the structured interview and SRS. We found evidence for high specificity for the structured interview. Conclusions A simplified DSM-based ASD structured diagnostic interview could serve as a useful diagnostic aid in the assessment of subjects with ASDs in clinical and research settings.

  2. The Student Perception of University Support and Structure Scale: Development and Validation

    Science.gov (United States)

    Wintre, Maxine G.; Gates, Shawn K. E.; Pancer, W. Mark; Pratt, Michael S.; Polivy, Janet; Birnie-Lefcovitch, S.; Adams, Gerald

    2009-01-01

    A new scale, the Student Perception of University Support and Structure Scale (SPUSS), was developed for research on the transition to university. The scale was based on concepts derived from Baumrind's (1971) theory of parenting styles. Data were obtained from two separate cohorts of freshmen (n=759 and 397) attending six Canadian universities of…

  3. Structure-borne noise of railway composite bridge: Numerical simulation and experimental validation

    Science.gov (United States)

    Li, Xiaozhen; Liu, Quanmin; Pei, Shiling; Song, Lizhong; Zhang, Xun

    2015-09-01

    In order to investigate the characteristics of the noise from steel-concrete composite bridges under high-speed train loading, a model used to predict the bridge-borne noise is established and validated through a field experiment. The numerical model for noise prediction is developed based on the combination of spatial train-track-bridge coupled vibration theory and Statistical Energy Analysis (SEA). Firstly, train-track-bridge coupled vibration is adopted to obtain the velocity time history of the bridge deck vibration. Then, the velocity time history is transferred into frequency domain through FFT to serve as the vibratory energy of SEA deck subsystems. Finally, the transmission of the vibratory energy is obtained by solving the energy balance equations of SEA, and the sound radiation is computed using the vibro-acoustic theory. The numerically computed noise level is verified by a field measurement. It is determined that the dominant frequency of steel-concrete composite bridge-borne noise is 20-1000 Hz. The noise from the bottom flange of steel longitudinal girder is less than other components in the whole frequency bands, while the noise from web of steel longitudinal girder is dominant in high frequency range above 315 Hz. The noise from concrete deck dominates in low-frequency domain ranges from 80 Hz to 160 Hz.

  4. Factor Structure and Validation of the Dimensional Assessment of Personality Questionnaire (DAPQ

    Directory of Open Access Journals (Sweden)

    Dino Krupić

    2015-12-01

    Full Text Available The last decade was extremely dynamic in the field of personality disorder. The extensive research has resulted with significant changes in conceptualization and assessment of personality psychopathology. DSM 5 has introduced a hybrid diagnostic model of personality disorders, which leads toward implementing dimensional instead of categorical approach to personality disorders. There are many questionnaires aimed to measure dimensions of personality psychopathology. However, they contain a large number of items, which may present a methodological problem in conducting research on large samples. Hence, the aim of this study is to present development of a short questionnaire aimed to measure main dimensions of personality psychopathology. The questionnaire, named Dimensional Assessment of Personality Traits Questionnaire (DAPTQ, contains 62 items distributed into 5 main scales; Negative Emotionality, Detachment, Compulsivity, Psychoticism and Antagonism, and two additional scales Grandiosity and Attention Seeking. Study was conducted on the sample of 456 high school students from Osijek and Koprivnica. The DAPTQ, YPI, LEXI - 70 and Ryff Scales of Psychological Well-Being were administered. Results indicate good psychometric properties, namely content, construct and convergent validity and reliability, of all scales of the DAPTQ. This paper discusses some measurement issues concerning personality psychopathology in adolescents' population and the ways in which they could be overcome.

  5. BEYOND FUNCTIONAL ASPECTS OF READING LITERACY: THEORETICAL STRUCTURE AND EMPIRICAL VALIDITY OF LITERARY LITERACY

    Directory of Open Access Journals (Sweden)

    PETRA STANAT

    2012-06-01

    Full Text Available An important educational aim in secondary school is to impart sufficient literary literacy to ensure that students are able to understand and reflect literary texts, such as lyrics, epics, or dramas. This paper presents the theoretical framework, challenges of item design and empirical results from an interdisciplinary research project which was designed to analyze a central aspect of literary literacy (LL, i.e. the ability to understand literary texts. Our study explores two questions: First, can literary literacy be assessed and modeled as a multi-dimensional construct with respect to content, form, and context? Second, is literary literacy distinguishable from factual reading literacy for expository texts? A sample of 1300 9th-graders (49% girls from 52 German school classes participated in the study and completed tests of literary literacy and factual reading literacy for expository texts. Ac-cording to the theory of semiotic aesthetics, literary literacy can be described as an at least two-dimensional construct consisting of semantic and idiolectal literary literacy. This was confirmed by the data. Although literary literacy and factual reading literacy for expository texts were strongly correlated, they present partly distinct competencies. More generally, the project resulted in a reliable and valid measure of a theory-based construct of literary literacy which can be used in student assessments as well as in studies exploring the teaching and learning processes relevant to the development of this competence.

  6. Structural damage identification in wind turbine blades using piezoelectric active sensing with ultrasonic validation

    Energy Technology Data Exchange (ETDEWEB)

    Claytor, Thomas N [Los Alamos National Laboratory; Ammerman, Curtt N [Los Alamos National Laboratory; Park, Gyu Hae [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory; Atterbury, Marie K [Los Alamos National Laboratory

    2010-01-01

    This paper gives a brief overview of a new project at LANL in structural damage identification for wind turbines. This project makes use of modeling capabilities and sensing technology to understand realistic blade loading on large turbine blades, with the goal of developing the technology needed to automatically detect early damage. Several structural health monitoring (SHM) techniques using piezoelectric active materials are being investigated for the development of wireless, low power sensors that interrogate sections of the wind turbine blade using Lamb wave propagation data, frequency response functions (FRFs), and time-series analysis methods. The modeling and sensor research will be compared with extensive experimental testing, including wind tunnel experiments, load and fatigue tests, and ultrasonic scans - on small- to mid-scale turbine blades. Furthermore, this study will investigate the effect of local damage on the global response of the blade by monitoring low-frequency response changes.

  7. Experiments to Populate and Validate a Processing Model for Polyurethane Foam: Additional Data for Structural Foams.

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Rekha R.; Celina, Mathias C.; Giron, Nicholas Henry; Long, Kevin Nicholas; Russick, Edward M.

    2015-01-01

    We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150 o C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.

  8. Analysis And Experimental Validation Of Structure-Borne Noise From Acoustic Enclosure Of Compressor

    OpenAIRE

    Deshmukh, Satish Konderao; Madhekar, Onkar Sunil

    2014-01-01

    Reduction of noise in a compressor is a complex criterion as many factors of machine enclosure contribute its effect on noise. When a panel of enclosure is acoustically excited, its vibrational response comprises both forced vibrational response at the excitation frequencies, and resonant response of all the relevant structural natural frequencies. These are excited due to the interactions of the forced bending waves with the panel boundaries. The non-resonant, forced modes tend to transmit m...

  9. Discriminate protein decoys from native by using a scoring function based on ubiquitous Phi and Psi angles computed for all atom.

    Science.gov (United States)

    Mishra, Avdesh; Iqbal, Sumaiya; Hoque, Md Tamjidul

    2016-06-01

    The success of solving the protein folding and structure prediction problems in molecular and structural biology relies on an accurate energy function. With the rapid advancement in the computational biology and bioinformatics fields, there is a growing need of solving unknown fold and structure faster and thus an accurate energy function is indispensable. To address this need, we develop a new potential function, namely 3DIGARS3.0, which is a linearly weighted combination of 3DIGARS, mined accessible surface area (ASA) and ubiquitously computed Phi (uPhi) and Psi (uPsi) energies - optimized by a Genetic Algorithm (GA). We use a dataset of 4332 protein-structures to generate uPhi and uPsi based score libraries to be used within the core 3DIGARS method. The optimized weight of each component is obtained by applying Genetic Algorithm based optimization on three challenging decoy sets. The improved 3DIGARS3.0 outperformed state-of-the-art methods significantly based on a set of independent test datasets. PMID:27029514

  10. Traffic weigh-in-motion (WIM measurements and validation of the Texas perpetual pavement structural design concept

    Directory of Open Access Journals (Sweden)

    Lubinda F. Walubita

    2011-01-01

    Full Text Available Over the past few years, the State of Texas has used perpetual pavement (PP structures on its heavily trafficked highways, where the expected 20-year truck-traffic estimate of 80 kN ESALs (equivalent single axle loads is in excess of 30 million. As a means to validate the Texas PP structural design concept and to make optimal future truck-traffic design recommendations, traffic Weigh In-Motion (WIM measurements were conducted and analyzed for two PP projects. The findings indicated that the initial 80 kN ESAL traffic design estimates for PP were comparable to the projections based on the actual measured WIM traffic data. However, underestimation of the hot mix asphalt layer dynamic moduli resulted in conservative designs for the PP structures. In addition, based on the successful use of the automated WIM data stations for traffic data collection, the paper highlights possible applications and advantages (as compared to conventional manual collection of traffic data of using detailed WIM traffic data information for future analyses of both highway operation and pavement structural design.

  11. Theoretical research and experimental validation of quasi-static load spectra on bogie frame structures of high-speed trains

    Science.gov (United States)

    Zhu, Ning; Sun, Shou-Guang; Li, Qiang; Zou, Hua

    2014-12-01

    One of the major problems in structural fatigue life analysis is establishing structural load spectra under actual operating conditions. This study conducts theoretical research and experimental validation of quasi-static load spectra on bogie frame structures of high-speed trains. The quasistatic load series that corresponds to quasi-static deformation modes are identified according to the structural form and bearing conditions of high-speed train bogie frames. Moreover, a force-measuring frame is designed and manufactured based on the quasi-static load series. The load decoupling model of the quasi-static load series is then established via calibration tests. Quasi-static load-time histories, together with online tests and decoupling analysis, are obtained for the intermediate range of the Beijing—Shanghai dedicated passenger line. The damage consistency calibration of the quasi-static discrete load spectra is performed according to a damage consistency criterion and a genetic algorithm. The calibrated damage that corresponds with the quasi-static discrete load spectra satisfies the safety requirements of bogie frames.

  12. Joint Test Report for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel

    Science.gov (United States)

    Lewis, Pattie

    2007-01-01

    Headquarters National Aeronautics and Space Administration (NASA) chartered the NASA Acquisition Pollution Prevention (AP2) Office to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the AP2 Office are to: (1) Reduce or eliminate the use of hazardous materials or hazardous processes at manufacturing, remanufacturing, and sustainment locations. (2) Avoid duplication of effort in actions required to reduce or eliminate hazardous materials through joint center cooperation and technology sharing. The objective of this project was to qualify candidate alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel applications at NASA facilities. This project compares the surface preparation/depainting performance of the proposed alternatives to existing surface preparation/depainting systems or standards. This Joint Test Report (JTR) contains the results of testing as per the outlines of the Joint Test Protocol (JTP), Joint Test Protocol for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, and the Field Test Plan (FTP), Field Evaluations Test Plan for Validation of Alternative Low-Emission Surface Preparation/Depainting Technologies for Structural Steel, for critical requirements and tests necessary to qualify alternatives for coating removal systems. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of government and industry participants. This JTR documents the results of the testing as well as any test modifications made during the execution of the project. This JTR is made available as a reference for future pollution prevention endeavors by other NASA Centers, the Department of Defense and commercial users to minimize duplication of effort. The current coating removal processes

  13. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics

    DEFF Research Database (Denmark)

    Christensen, Anders Steen; Linnet, Troels Emtekær; Borg, Mikael;

    2013-01-01

    We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts - sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM) calculations and reproduces high level...... QM results obtained for a small protein with an RMSD of 0.25 ppm (r = 0.94). ProCS is interfaced with the PHAISTOS protein simulation program and is used to infer statistical protein ensembles that reflect experimentally measured amide proton chemical shift values. Such chemical shift...

  14. Original article Reliability, factor structure, and construct validity of the Polish version of the sport imagery ability measure

    Directory of Open Access Journals (Sweden)

    Dagmara Budnik-Przybylska

    2014-12-01

    Full Text Available Background An important component of mental training in sport is the utilization of positive imagery. The “human brain cannot distinguish between an imagined experience and a real experience. The same areas of the brain light up in an imagined experience or imagined performance as in a real experience or performance. For that reason, positive performance imagery has enormous potential” (Orlick, 2008, p. 101. Imagery “has been described as a centre pillar of applied sport psychology” research (Morris, Spittle, & Perry, 2004, p. 344. The aim of the present study was to examine reliability and validity characteristics of the Polish language version of the Sport Imagery Ability Measure (SIAM. Participants and procedure Polish athletes (N = 316 from a range of sports and competitive levels completed the 48 item SIAM. The participants (163 male, 153 female were aged between 12 and 57 years (M = 22.15, SD = 8.25. Results Results indicated that the SIAM had sound internal consistency and maintained good stability over a 3-week period. Confirmatory factor analysis demonstrated that the a priori 3-factor structure of the SIAM resulted in a set of acceptable and poor fit indices (CFI = .91, NFI = .90, RMSEA = .12. Finally, differences in athletes’ imagery abilities were examined in relation to competitive level, gender, and age. Conclusions Overall, results generally supported the reliability and construct validity of the Polish version of the SIAM.

  15. Exploring RNA structure by integrative molecular modelling

    DEFF Research Database (Denmark)

    Masquida, Benoît; Beckert, Bertrand; Jossinet, Fabrice

    2010-01-01

    RNA molecular modelling is adequate to rapidly tackle the structure of RNA molecules. With new structured RNAs constituting a central class of cellular regulators discovered every year, the need for swift and reliable modelling methods is more crucial than ever. The pragmatic method based...... on interactive all-atom molecular modelling relies on the observation that specific structural motifs are recurrently found in RNA sequences. Once identified by a combination of comparative sequence analysis and biochemical data, the motifs composing the secondary structure of a given RNA can be extruded...... in three dimensions (3D) and used as building blocks assembled manually during a bioinformatic interactive process. Comparing the models to the corresponding crystal structures has validated the method as being powerful to predict the RNA topology and architecture while being less accurate regarding...

  16. Boundary layer structure and stability classification validated with CO2 concentrations over the Northern Spanish Plateau

    Directory of Open Access Journals (Sweden)

    B. de Torre

    2009-01-01

    Full Text Available A description of the lower boundary layer is vital to enhance our understanding of dispersion processes. In this paper, Radio Acoustic Sounding System sodar measurements obtained over three years were used to calculate the Brunt-Väisälä frequency and the Monin-Obukhov length. The Brunt-Väisälä frequency enabled investigation of the structure of this layer. At night, several layers were noticeable and the maximum was observed at the first level, 40 m, whereas during the day, it was present at about 320 m. The Monin-Obukhov length was calculated with the four first levels measured, 40–100 m, by an original iterative method and used to establish four stability classes: drainage, extremely stable, stable and unstable. Wind speed and temperature median profiles linked to these classes were also presented. Wind speeds were the lowest, but temperatures were the highest and inversions were intense at night in drainage situations. However, unstable situations were linked to high wind speeds and superadiabatic temperature profiles. Detrended CO2 concentrations were used to determine the goodness of the classification proposed evidencing values which under drainage at night in spring were nearly 28 ppm higher than those corresponding to unstable situations. Finally, atmosphere structure was presented for the proposed stability classes and related with wind speed profiles. Under extremely stable situations, low level jets were coupled to the surface, with median wind speeds below 8 m s−1 and cores occasionally at 120 m. However, jets were uncoupled in stable situations, wind speed medians were higher than 11 m s−1 and their core heights were around 200 m.

  17. Structural and construct validity of the Whiplash Disability Questionnaire in adults with acute whiplash-associated disorders

    DEFF Research Database (Denmark)

    Stupar, Maja; Côté, Pierre; Beaton, Dorcas E;

    2015-01-01

    determine the structural and construct validity of the WDQ in individuals with acute WAD. STUDY DESIGN/SETTING: This was a cohort study. PATIENT SAMPLE: Ontario adults with WAD were enrolled within 3 weeks of their motor vehicle collision. OUTCOME MEASURES: The outcome measure was the WDQ. METHODS: We...... [CES-D]). RESULTS: The mean age of the 130 participants was 42.1 years (standard deviation [SD]=13.2), and 70% were women. Twenty-six percent had WAD I, 73.1% had WAD II, and 0.8% had WAD III. Mean time since injury was 6.5 days (SD=4.9). The mean WDQ score was 49.8 (SD=29.1). Our analysis suggested...

  18. Extending the Newns-Anderson model to molecules with floppy degrees of freedom. Validation by electronic structure calculations

    CERN Document Server

    Baldea, Ioan

    2012-01-01

    In cases where reorganization is important, present theoretical studies of molecular transport have inherently to resort to models. The Newns-Anderson model is ubiquitous for this purpose but, to author's knowledge, attempts to validate/challenge this model by microscopic calculations are missing in the literature. In this work, results of electronic structure calculations are presented, which demonstrate that the conventional Newns-Anderson model fails to describe redox-active tunneling junctions of recent experimental interest. For the case considered, the ($4, 4^\\prime$)-bipyridine molecule, the failure traces back to the floppy degree of freedom represented by the relative rotation of the two pyridine rings. Expressions that generalize the Newns-Anderson model are deduced, which include significant anharmonicities. These expressions can be straightforwardly utilized as input information in calculations of the partially coherent transport.

  19. Constitutive Theories for Woven Composite Structures Subjected to Shock Loading; Experimental Validation Using a Conical Shock Tube

    Directory of Open Access Journals (Sweden)

    David R. Hufner

    2012-01-01

    Full Text Available Woven polymer-based composites are currently used in a wide range of marine applications. These materials often exhibit highly nonlinear, rate dependent, anisotropic behavior under shock loadings. Correlation to transient response data, beyond an initial peak, is often difficult. The state of damage evolves throughout the time history and the unloading response varies based on the amount, and nature of, the accumulated damage. Constitutive theories that address the loading and unloading responses have been developed and integrated with each other. A complete theory, applicable to transient dynamic analysis, is presented. The model is implemented within the commercial finite element code, Abaqus, in the form of a user material subroutine. In this study, the conical shock tube is used to experimentally reproduce the high strain rates and fluid structure interactions typical of underwater shock loadings. The conical shock tube data is used to validate analytical model predictions. Simulation results are in good agreement with test data.

  20. Theorie macroscopique de propagation du son dans les milieux poreux 'à structure rigide permettant la dispersion spatiale: principe et validation

    OpenAIRE

    Nemati, Navid

    2012-01-01

    Ce travail présente et valide une théorie nonlocale nouvelle et généralisée, de la propagation acoustique dans les milieux poreux à structure rigide, saturés par un fluide viscothermique. Cette théorie linéaire permet de dépasser les limites de la théorie classique basée sur la théorie de l'homogénéisation. Elle prend en compte non seulement les phénomènes de dispersion temporelle, mais aussi ceux de dispersion spatiale. Dans le cadre de la nouvelle approche, une nouvelle procédure d'homogéné...

  1. The Feeding Practices and Structure Questionnaire (FPSQ-28): A parsimonious version validated for longitudinal use from 2 to 5 years.

    Science.gov (United States)

    Jansen, Elena; Williams, Kate E; Mallan, Kimberley M; Nicholson, Jan M; Daniels, Lynne A

    2016-05-01

    Prospective studies and intervention evaluations that examine change over time assume that measurement tools measure the same construct at each occasion. In the area of parent-child feeding practices, longitudinal measurement properties of the questionnaires used are rarely verified. To ascertain that measured change in feeding practices reflects true change rather than change in the assessment, structure, or conceptualisation of the constructs over time, this study examined longitudinal measurement invariance of the Feeding Practices and Structure Questionnaire (FPSQ) subscales (9 constructs; 40 items) across 3 time points. Mothers participating in the NOURISH trial reported their feeding practices when children were aged 2, 3.7, and 5 years (N = 404). Confirmatory Factor Analysis (CFA) within a structural equation modelling framework was used. Comparisons of initial cross-sectional models followed by longitudinal modelling of subscales, resulted in the removal of 12 items, including two redundant or poorly performing subscales. The resulting 28-item FPSQ-28 comprised 7 multi-item subscales: Reward for Behaviour, Reward for Eating, Persuasive Feeding, Overt Restriction, Covert Restriction, Structured Meal Setting and Structured Meal Timing. All subscales showed good fit over 3 time points and each displayed at least partial scalar (thresholds equal) longitudinal measurement invariance. We recommend the use of a separate single item indicator to assess the family meal setting. This is the first study to examine longitudinal measurement invariance in a feeding practices questionnaire. Invariance was established, indicating that the subscales of the shortened FPSQ-28 can be used with mothers to validly assess change in 7 feeding constructs in samples of children aged 2-5 years of age. PMID:26911263

  2. Structure-preserving model reduction for spatially interconnected systems with experimental validation on an actuated beam

    Science.gov (United States)

    Al-Taie, Fatimah; Werner, Herbert

    2016-06-01

    A technique for model reduction of exponentially stable spatially interconnected systems is presented, where the order of the reduced model is determined by the number of truncated small generalised singular values of the structured solutions to a pair of Lyapunov inequalities. For parameter-invariant spatially interconnected systems, the technique is based on solving a pair of Lyapunov inequalities in continuous-time and -space domain with a rank constraint. Using log-det and cone complementarity methods, an improved error bound can be obtained. The approach is extended to spatially parameter-varying systems, and a balanced truncation approach using parameter-dependent Gramians is proposed to reduce the conservatism caused by the use of constant Gramians. This is done by considering two important operators, which can be used to represent multidimensional systems (temporal- and spatial-linear parameter varying interconnected systems). The results are illustrated with their application to an experimentally identified spatially interconnected model of an actuated beam; the experimentally obtained response to an excitation signal is compared with the response predicted by a reduced model.

  3. Validation of new sub-group algorithms for resonance self-shielding in heterogeneous structures

    International Nuclear Information System (INIS)

    Within the European cooperation on fast reactors a new cell code, ECCO, is being developed. This code uses the sub-group method to handle the resonance self-shielding in complex heterogeneous structures. The ECCO code uses several different energy group schemes. The fine group library allows a reference calculation, while the broad group library permits faster ECCO runs for design calculations. Both fine and broad group libraries contain infinite dilution cross-sections and sub-group parameters, as it is the case for the library FGL5 used by the MURAL code and for the library CARNAVAL4 used by the HETAIRE code. Libraries for ECCO can be created by processing the JEF evaluated nuclear data files. The CALENDF code generates sub-group parameters by an original method while the code system THEMIS, derived from NJOY, is used to calculate infinite dilution cross-sections and the other nuclear data. The consistency between CALENDF and NJOY/THEMIS for the calculation of shielded cross-sections is sufficiently accurate. Results of calculations using these two libraries give good agreement for cells typical of the fast reactor programme. It will be then acceptable to use broad group calculations in cases where fine group calculations are too costly, for example when treating very complicated geometries

  4. Lotung large-scale seismic experiment and soil-structure interaction method validation

    International Nuclear Information System (INIS)

    This paper describes the EPRI current on-site large-scale soil-structure interaction (SSI) research. The objectives of the research are: (1) to obtain an earthquake database which can be used to substantiate SSI models and analysis methods; (2) to develop realistic SSI analysis guidelines and procedures based on experimental-analytical correlation; and (3) to quantify nuclear power plant reactor containment and internal component's seismic margin based on earthquake experience data. The analysis phase of the research was conducted with the cooperation of the U.S. NRC and Taipower. A round-robin approach was utilized with emphasis on blind predictions and independent assessment of existing methodologies. A total of 13 research teams from the United States, the Republic of China, Japan, and Switzerland participated in the effort. A workshop was held in December 1987 where research results and findings were presented. Further effort is ongoing to synthesize the results and findings for providing technical bases of developing improved SSI analyses guidelines and procedures. (orig./HP)

  5. The Herdecke questionnaire on quality of life (HLQ): Validation of factorial structure and development of a short form within a naturopathy treated in-patient collective

    OpenAIRE

    Beer Andre-Michael; Büssing Arndt; Ostermann Thomas; Matthiessen Peter F

    2005-01-01

    Abstract Background Quality of life (QoL) of patients has become a central evaluation parameter that also acts as an aid for decisions related to treatment strategies particularly for patients with chronic illnesses. In Germany, one of the newer instruments attempting to measure distinct QoL aspects is the "Herdecke Questionnaire for Quality of Life" (HLQ). In this study, we aimed to validate the HLQ with respect to its factorial structure, and to develop a short form. The validation has been...

  6. A French Translation of the Childhood Anxiety Sensitivity Index (CASI): Factor Structure, Reliability and Validity of This Scale in a Nonclinical Sample of Children

    OpenAIRE

    Stassart, C; Etienne, A M

    2014-01-01

    Introduction: Anxiety sensitivity (AS) refers to the fear of anxiety-related sensations due to beliefs that these sensations will lead to catastrophic outcomes. AS plays a central role in the etiology and maintenance of anxiety disorders. From a clinical perspective, it therefore seems important to possess a valid scale to assess AS in children. Objective, Method: This study examines the factor structure, reliability, and validity of the French translation of the Childhood Anxiety Sensitivity...

  7. Factor structure, reliability, and known groups validity of the german version of the childhood trauma questionnaire (short-form) in swiss patients and nonpatients

    OpenAIRE

    Karos, Kai; Niederstrasser, Nils Georg; Abidi, Latifa; Bernstein, David P; Bader, Klaus

    2014-01-01

    The Childhood Trauma Questionnaire-Short Form is the most widely used instrument to assess childhood trauma and has been translated into 10 languages. However, research into validity and reliability of these translated versions is scarce. The present study aimed to investigate the factor structure, internal consistency, reliability, and known-groups validity of the German Childhood Trauma Questionnaire-Short Form (Bernstein & Fink, 1998). Six-hundred and sixty-one clinical and nonclinical par...

  8. Predictive validity of measurements of clinical competence using the team objective structured bedside assessment (TOSBA): assessing the clinical competence of final year medical students.

    OpenAIRE

    Meagher, Frances M; Butler, Marcus W.; Miller, Stanley DW; Costello, Richard; Conroy, Ronán; McElvaney, Noel G.

    2009-01-01

    BACKGROUND: The importance of valid and reliable assessment of student competence and performance is gaining increased recognition. Provision of valid patient-based formative assessment is an increasing challenge for clinical teachers in a busy hospital setting. A formative assessment tool that reliably predicts performance in the summative setting would be of value to both students and teachers. AIM: This study explores the utility of the team objective structured bedside assessment (TOSBA),...

  9. Validation of soil-structure interaction models using in-plant test data from Japan: Final report

    International Nuclear Information System (INIS)

    Data from the in-plant forced-vibration test conducted on the reactor building of the Tokai-2 (1100 MW, BWR) nuclear power plant in Japan were used for correlation with the results simulation analyses to evaluate the validity of the lumped parameter soil-structure interaction (SSI) models commonly adopted in the US nuclear industry for seismic analyses. The lumped parameter SSI models evaluated consist of lumped mass stick models for the reactor building structure and lumped parameter foundation models represented by either frequency dependent or frequency independent foundation impedances including the effect of embedment. Seismic response analyses were also performed for the Tokai-2 reactor building to evaluate the conservatism of the Japanese seismic design practice for nuclear power plants. The results of seismic analyses using the SSI models correlated with the forced-vibration test results showed that the design basis seismic response based on the Japanese design practice adopted at the time the Tokai-2 plant was designed (assuming a very low radiation damping of 5%) is extremely conservative, since the actual foundation radiation damping based on the forced-vibration test results is in the neighborhood of 15%

  10. Control Structure Impact on the Flying Performance of the Multi-Rotor VTOL Platform - Design, Analysis and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Roman Czyba

    2013-01-01

    Full Text Available The aim of this research is to examine the different control strategies for the unmanned aerial vehicles (UAV. The control task is formulated as an angular stabilization of the four rotor platform, and also as a tracking problem of chosen state variables. The PID algorithm has been considered in three structures in respect of the optimal control signal applied to the actuators. For better performance of the quadrotor in hover mode the cascade control system has been proposed. The simulation results of attitude control with different PID controller architectures are presented, and confirm the effectiveness of the proposed control structure and theoretical expectations. Moreover, the design and the practical realization of the control architecture on the experimental aerial vehicle are described. The fast prototyping method together with Matlab/Simulink software and DAQ hardware are used for both evolution and validation of control algorithms. The capacity of the attitude stabilization system is important in the development process of more advanced functionality of autonomous flying vehicles; therefore it needs to be highlighted and taken into careful consideration.

  11. Validation and Benchmarking of a Practical Free Magnetic Energy and Relative Magnetic Helicity Budget Calculation in Solar Magnetic Structures

    CERN Document Server

    Moraitis, K; Georgoulis, M K; Archontis, V

    2014-01-01

    In earlier works we introduced and tested a nonlinear force-free (NLFF) method designed to self-consistently calculate the free magnetic energy and the relative magnetic helicity budgets of the corona of observed solar magnetic structures. The method requires, in principle, only a single, photospheric or low-chromospheric, vector magnetogram of a quiet-Sun patch or an active region and performs calculations in the absence of three-dimensional magnetic and velocity-field information. In this work we strictly validate this method using three-dimensional coronal magnetic fields. Benchmarking employs both synthetic, three-dimensional magnetohydrodynamic simulations and nonlinear force-free field extrapolations of the active-region solar corona. We find that our time-efficient NLFF method provides budgets that differ from those of more demanding semi-analytical methods by a factor of ~3, at most. This difference is expected from the physical concept and the construction of the method. Temporal correlations show mo...

  12. A Test and Cross-Validation of the Revised Two-Factor Study Process Questionnaire Factor Structure among Western University Students

    Science.gov (United States)

    Immekus, Jason C.; Imbrie, P. K.

    2010-01-01

    The Revised Two-Factor Study Process Questionnaire (R-SPQ-2F) is a measure of university students' approach to learning. Original evaluation of the scale's psychometric properties was based on a sample of Hong Kong university students' scores. The purpose of this study was to test and cross-validate the R-SPQ-2F factor structure, based on separate…

  13. Modeling validation to structural flaws in the foundations of oil tanks; Validacao de modelagem para estudo de alteracoes estruturais em fundacoes de tanques de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Couto, Larissa Goncalves; Leite, Sandro Passos, E-mail: leite_sp@ig.com.br [Fundacao Tecnico-Educacional Souza Marques, Rio de Janeiro, RJ (Brazil). Faculdade de Engenharia; Pereira, Walsan Wagner [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    This paper presents the modeling of an experiment used to study the application of backscattered neutrons in the identification of structural flaws in the foundations of oil tanks. This modeling was a preliminary validation procedure of the method of calculation, performed with the radiation transport code MCNP, to study the application of backscattered neutrons as inspection tool. (author)

  14. The Theory of Planned Behavior (TPB) and Pre-Service Teachers' Technology Acceptance: A Validation Study Using Structural Equation Modeling

    Science.gov (United States)

    Teo, Timothy; Tan, Lynde

    2012-01-01

    This study applies the theory of planned behavior (TPB), a theory that is commonly used in commercial settings, to the educational context to explain pre-service teachers' technology acceptance. It is also interested in examining its validity when used for this purpose. It has found evidence that the TPB is a valid model to explain pre-service…

  15. Extended criteria and predictors in college admission: Exploring the structure of study success and investigating the validity of domain knowledge

    Directory of Open Access Journals (Sweden)

    OLGA KUNINA

    2007-06-01

    Full Text Available The utility of aptitude tests and intelligence measures in the prediction of the success in college is one of the empirically best supported results in ability research. However, the structure of the criterion “study success” has not been appropriately investigated so far. Moreover, it remains unclear which aspect of intelligence – fluid intelligence or crystallized intelligence – has the major impact on the prediction. In three studies we have investigated the dimensionality of the criterion achievements as well as the relative contributions of competing ability predictors. In the first study, the dimensionality of college grades was explored in a sample of 629 alumni. A measurement model with two correlated latent factors distinguishing undergraduate college grades on the one hand from graduate college grades on the other hand had the best fit to the data. In the second study, a group of 179 graduate students completed a Psychology knowledge test and provided available college grades in undergraduate studies. A model separating a general latent factor for Psychology knowledge from a nested method factor for college grades, and a second nested factor for “experimental orientation” had the best fit to the data. In the third study the predictive power of domain specific knowledge tests in Mathematics, English, and Biology was investigated. A sample of 387 undergraduate students in this prospective study additionally completed a compilation of fluid intelligence tests. The results of this study indicate as expected that: a ability measures are incrementally predictive over school grades in predicting exam grades; and b that knowledge tests from relevant domains were incrementally predictive over fluid intelligence. The results of these studies suggest that criteria for college admission tests deserve and warrant more attention, and that domain specific ability indicators can contribute to the predictive validity of established

  16. Characterization of the thermal structure inside an urban canyon: field measurements and validation of a simple model

    Science.gov (United States)

    Giovannini, Lorenzo; Zardi, Dino; de Franceschi, Massimiliano

    2013-04-01

    The results of measurement campaigns are analyzed to investigate the thermal structure in an urban canyon, and to validate a simplified model simulating the air and surface temperatures from surface energy budgets. Starting from measurements at roof-top level, the model provides time series of air and surface temperatures, as well as surface fluxes. Two campaigns were carried out in summer 2007 and in winter 2008/09 in a street of the city of Trento (Italy). Temperature sensors were placed at various levels near the walls flanking the canyon and on a traffic light in the street center. Furthermore, the atmosphere above the mean roof-top level was monitored by a weather station on top of a tower located nearby. Air temperatures near the walls, being strongly influenced by direct solar radiation, display considerable contrasts between the opposite sides of the canyon. On the other hand, when solar radiation is weak or absent, the temperature field remains rather homogeneous.Moreover, air temperature inside the canyon is generally higher than above roof level, with larger differences during summertime. Air temperatures from the above street measurements are well simulated by the model in both seasons. Furthermore, the modeled surface temperatures are tested against a dataset of wall surface temperatures from the Advanced Tools for Rational Energy Use Towards Sustainability-Photocatalytic Innovative Coverings Applications for Depollution (ATREUS-PICADA) experiment, and a very good agreement is found. Results suggest that themodel is a reliable and convenient tool for simplified assessment of climatic conditions occurring in urban canyons under various weather situations.

  17. Validation of geometric measurements of the left atrium and pulmonary veins for analysis of reverse structural remodeling following ablation therapy

    Science.gov (United States)

    Rettmann, M. E.; Holmes, D. R., III; Gunawan, M. S.; Ge, X.; Karwoski, R. A.; Breen, J. F.; Packer, D. L.; Robb, R. A.

    2012-03-01

    Geometric analysis of the left atrium and pulmonary veins is important for studying reverse structural remodeling following cardiac ablation therapy. It has been shown that the left atrium decreases in volume and the pulmonary vein ostia decrease in diameter following ablation therapy. Most analysis techniques, however, require laborious manual tracing of image cross-sections. Pulmonary vein diameters are typically measured at the junction between the left atrium and pulmonary veins, called the pulmonary vein ostia, with manually drawn lines on volume renderings or on image cross-sections. In this work, we describe a technique for making semi-automatic measurements of the left atrium and pulmonary vein ostial diameters from high resolution CT scans and multi-phase datasets. The left atrium and pulmonary veins are segmented from a CT volume using a 3D volume approach and cut planes are interactively positioned to separate the pulmonary veins from the body of the left atrium. The cut plane is also used to compute the pulmonary vein ostial diameter. Validation experiments are presented which demonstrate the ability to repeatedly measure left atrial volume and pulmonary vein diameters from high resolution CT scans, as well as the feasibility of this approach for analyzing dynamic, multi-phase datasets. In the high resolution CT scans the left atrial volume measurements show high repeatability with approximately 4% intra-rater repeatability and 8% inter-rater repeatability. Intra- and inter-rater repeatability for pulmonary vein diameter measurements range from approximately 2 to 4 mm. For the multi-phase CT datasets, differences in left atrial volumes between a standard slice-by-slice approach and the proposed 3D volume approach are small, with percent differences on the order of 3% to 6%.

  18. Development and validation of a bedside risk score for MRSA among patients hospitalized with complicated skin and skin structure infections

    Directory of Open Access Journals (Sweden)

    Zilberberg Marya D

    2012-07-01

    Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA is a frequent cause of complicated skin and skin structure infections (cSSSI. Patients with MRSA require different empiric treatment than those with non-MRSA infections, yet no accurate tools exist to aid in stratifying the risk for a MRSA cSSSI. We sought to develop a simple bedside decision rule to tailor empiric coverage more accurately. Methods We conducted a large multicenter (N=62 hospitals retrospective cohort study in a US-based database between April 2005 and March 2009. All adult initial admissions with ICD-9-CM codes specific to cSSSI were included. Patients admitted with MRSA vs. non-MRSA were compared with regard to baseline demographic, clinical and hospital characteristics. We developed and validated a model to predict the risk of MRSA, and compared its performance via sensitivity, specificity and other classification statistics to the healthcare-associated (HCA infection risk factors. Results Of the 7,183 patients with cSSSI, 2,387 (33.2% had MRSA. Factors discriminating MRSA from non-MRSA were age, African-American race, no evidence of diabetes mellitus, cancer or renal dysfunction, and prior history of cardiac dysrhythmia. The score ranging from 0 to 8 points exhibited a consistent dose–response relationship. A MRSA score of 5 or higher was superior to the HCA classification in all characteristics, while that of 4 or higher was superior on all metrics except specificity. Conclusions MRSA is present in 1/3 of all hospitalized cSSSI. A simple bedside risk score can help discriminate the risk for MRSA vs. other pathogens with improved accuracy compared to the HCA definition.

  19. Application of 3D digital image correlation for development and validation of FEM model of self-supporting metal plates structures

    Science.gov (United States)

    Malowany, Krzysztof; Malesa, Marcin; Piekarczuk, Artur; Kujawińska, Małgorzata; Skrzypczak, Paweł; Wiech, Przemysław

    2016-04-01

    Many building structures due to complex geometry and nonlinear material properties are difficult to be analyzed with FEM methods. A good example is a self-supporting metal plates structure. Considering uncommon geometry and material characteristic of a metal plate (due to plastic deformations, cross section of a trough, a goffer pattern), the local loss of stability can occur in unexpected regions. Therefore, the hybrid experimental-numerical methodology of analysis and optimization of metal plates structures has been developed. The methodology is based on three steps of development and validation of a numerical model with utilization of Digital Image Correlation measurements. In each step, the measurements are performed in different environments, with different accuracies and different scales. In this paper, the results of analysis performed with Digital Image Correlation, that enabled development and validation of FEM model are presented. The performed modification of a measurement setup is also described.

  20. Organizational Leadership Assessment in Servant Organizations: Adaptation for Turkish Culture, Language Validity and Examination of Factor Structure

    OpenAIRE

    KAHVECİ, Hakkı; Ahmet AYPAY

    2012-01-01

    The purpose of this study is to adapt Laub’s (1999) Organizational Leadership Assessment in Servant Organizations to Turkish literaturate on servant leadership. Validity and reliability analyzes were conducted. The original instrument included 60 questions and six dimensions. Data was collected from primaryschool teachers in Eskişehir and Balıkesir. Descriptive statistics and exploratory factor analyis were used to analyze the data. Resulst indicated that, a valid and relaible instrument incl...

  1. Reliability and validity of a semi-structured DSM-based diagnostic interview module for the assessment of Attention Deficit Hyperactivity Disorder in adult psychiatric outpatients.

    Science.gov (United States)

    Gorlin, Eugenia I; Dalrymple, Kristy; Chelminski, Iwona; Zimmerman, Mark

    2016-08-30

    Despite growing recognition that the symptoms and functional impairments of Attention Deficit/Hyperactivity Disorder (ADHD) persist into adulthood, only a few psychometrically sound diagnostic measures have been developed for the assessment of ADHD in adults, and none have been validated for use in a broad treatment-seeking psychiatric sample. The current study presents the reliability and validity of a semi-structured DSM-based diagnostic interview module for ADHD, which was administered to 1194 adults presenting to an outpatient psychiatric practice. The module showed excellent internal consistency and interrater reliability, good convergent and discriminant validity (as indexed by relatively high correlations with self-report measures of ADHD and ADHD-related constructs and little or no correlation with other, non-ADHD symptom domains), and good construct validity (as indexed by significantly higher rates of psychosocial impairment and self-reported family history of ADHD in individuals who meet criteria for an ADHD diagnosis). This instrument is thus a reliable and valid diagnostic tool for the detection of ADHD in adults presenting for psychiatric evaluation and treatment. PMID:27259136

  2. Magnetic Decoupling Design and Experimental Validation of a Radial-Radial Flux Compound-Structure Permanent-Magnet Synchronous Machine for HEVs

    Directory of Open Access Journals (Sweden)

    Zhiyi Song

    2012-10-01

    Full Text Available The radial-radial flux compound-structure permanent-magnet synchronous machine (CS-PMSM, integrated by two concentrically arranged permanent-magnet electric machines, is an electromagnetic power-splitting device for hybrid electric vehicles (HEVs. As the two electric machines share a rotor as structural and magnetic common part, their magnetic paths are coupled, leading to possible mutual magnetic-field interference and complex control. In this paper, a design method to ensure magnetic decoupling with minimum yoke thickness of the common rotor is investigated. A prototype machine is designed based on the proposed method, and the feasibility of magnetic decoupling and independent control is validated by experimental tests of mutual influence. The CS-PMSM is tested by a designed driving cycle, and functions to act as starter motor, generator and to help the internal combustion engine (ICE operate at optimum efficiency are validated.

  3. Organizational Leadership Assessment in Servant Organizations: Adaptation for Turkish Culture, Language Validity and Examination of Factor Structure

    Directory of Open Access Journals (Sweden)

    Hakkı KAHVECİ

    2012-06-01

    Full Text Available The purpose of this study is to adapt Laub’s (1999 Organizational Leadership Assessment in Servant Organizations to Turkish literaturate on servant leadership. Validity and reliability analyzes were conducted. The original instrument included 60 questions and six dimensions. Data was collected from primaryschool teachers in Eskişehir and Balıkesir. Descriptive statistics and exploratory factor analyis were used to analyze the data. Resulst indicated that, a valid and relaible instrument included 54 questions with two dimensions.

  4. Factor structure and measurement invariance of the Health Education Impact Questionnaire: Does the subjectivity of the response perspective threaten the contextual validity of inferences?

    OpenAIRE

    Elsworth, Gerald R; Nolte, Sandra; Osborne, Richard H

    2015-01-01

    Objective: On-going evidence is required to support the validity of inferences about change and group differences in the evaluation of health programs, particularly when self-report scales requiring substantial subjectivity in response generation are used as outcome measures. Following this reasoning, the aim of this study was to replicate the factor structure and investigate the measurement invariance of the latest version of the Health Education Impact Questionnaire, a widely used health pr...

  5. The French Version of the Screen for Child Anxiety Related Emotional Disorders-Revised (Scared-R): Factor Structure, Convergent and Divergent Validity in a Sample of Teenagers

    OpenAIRE

    Martine Bouvard; Jean-Luc Roulin; Anne Denis

    2013-01-01

    The principal objective of this study is to provide data on the French version of the SCARED-R. This article investigates the factor structure of the French version of the Screen for Child Anxiety Related Emotional Disorders-Revised (SCARED-R) and its convergent and divergent validity. 704 normal adolescents aged 10 to 19 years completed the questionnaires in their classrooms. A sub-sample of 595 adolescents also completed an anxiety questionnaire (the French version of the Fear Survey Schedu...

  6. The Impact of Structural Break(s on the Validity of Purchasing Power Parity in Turkey: Evidence from Zivot-Andrews and Lagrange Multiplier Unit Root Tests

    Directory of Open Access Journals (Sweden)

    Hakan Kum

    2012-01-01

    Full Text Available This study examines the validity of the purchasing power parity (PPP in Turkey for annual data from 1953 to 2009. While results from both the ADF unit root and the DF-GLS unit root test indicate mixed results, PPP holds for Turkey with the presence of structural breaks which are obtained by Zivot and Andrews and Lagrange Multiplier unit root tests.

  7. Reliability and validity of ADHD diagnostic criteria in the Assessment System for Individuals with ADHD (ASIA): a Japanese semi-structured diagnostic interview

    OpenAIRE

    Takeda, Toshinobu; Tsuji, Yui; Uwatoko, Teruhisa; Kurita, Hiroshi

    2015-01-01

    Background With reports of a high prevalence of attention-deficit/hyperactivity disorder (ADHD) in adults, publication of ADHD diagnostic criteria in DSM-5, and the urgent need for a relevant diagnostic instrument conforming to DSM-5, we developed the Assessment System for Individuals with ADHD (ASIA), a Japanese semi-structured diagnostic interview. We report here the reliability and validity of ASIA ADHD diagnostic criteria. Methods ASIA ADHD criterion A corresponds to DSM-5 ADHD criterion ...

  8. Reliability and validity of ADHD diagnostic criteria in the Assessment System for Individuals with ADHD (ASIA): A Japanese semi-structured diagnostic interview

    OpenAIRE

    Takeda, Toshinobu; Tsuji, Yui; Uwatoko, Teruhisa; Kurita, Hiroshi

    2015-01-01

    Background: With reports of a high prevalence of attention-deficit/hyperactivity disorder (ADHD) in adults, publication of ADHD diagnostic criteria in DSM-5, and the urgent need for a relevant diagnostic instrument conforming to DSM-5, we developed the Assessment System for Individuals with ADHD (ASIA), a Japanese semi-structured diagnostic interview. We report here the reliability and validity of ASIA ADHD diagnostic criteria. Methods: ASIA ADHD criterion A corresponds to DSM-5 ADHD criterio...

  9. Study of the Reliability and Validity of Objective Structured Clinical Examination (OSCE) in the Assessment of Clinical Skills of Audiology Students

    OpenAIRE

    Nickbakht, Mansoureh; Amiri, Marzieh; Latifi, Seyed Mahmoud

    2013-01-01

    Introduction: Audiology students should possess clinical competence and skills. To achieve this, their clinical skills must be properly assessed. The Objective Structured Clinical Examination (OSCE) is a standard and fair examination of clinical competence. The goal of this study is to devise a checklist of OSCE examination criteria and study their validity and reliability for assessing the clinical competence of Audiology students. Methods: Among the various procedures in which audiology stu...

  10. Finite element model validation of bridge based on structural health monitoring—Part I: Response surface-based finite element model updating

    Directory of Open Access Journals (Sweden)

    Zhouhong Zong

    2015-08-01

    Full Text Available In the engineering practice, merging statistical analysis into structural evaluation and assessment is a tendency in the future. As a combination of mathematical and statistical techniques, response surface (RS methodology has been successfully applied to design optimization, response prediction and model validation. With the aid of RS methodology, these two serial papers present a finite element (FE model updating and validation method for bridge structures based on structural health monitoring. The key issues to implement such a model updating are discussed in this paper, such as design of experiment, parameter screening, construction of high-order polynomial response surface model, optimization methods and precision inspection of RS model. The proposed procedure is illustrated by a prestressed concrete continuous rigid-frame bridge monitored under operational conditions. The results from the updated FE model have been compared with those obtained from online health monitoring system. The real application to a full-size bridge has demonstrated that the FE model updating process is efficient and convenient. The updated FE model can relatively reflect the actual condition of Xiabaishi Bridge in the design space of parameters and can be further applied to FE model validation and damage identification.

  11. Factor Structure of the Schalock and Keith Quality of Life Questionnaire (QOL-Q): Validation on Mexican and Spanish Samples

    Science.gov (United States)

    Caballo, C.; Crespo, M.; Jenaro, C.; Verdugo, M. A.; Martinez, J. L.

    2005-01-01

    Background: The Quality of Life Questionnaire (QOL-Q) is used widely to evaluate the quality of life of persons with intellectual disability (ID). Its validity for use with Spanish-speaking cultures has been demonstrated for individuals with visual disabilities, but not for those with physical or intellectual disabilities. Such was the purpose of…

  12. Using Structural Equation Modeling to Validate the Theory of Planned Behavior as a Model for Predicting Student Cheating

    Science.gov (United States)

    Mayhew, Matthew J.; Hubbard, Steven M.; Finelli, Cynthia J.; Harding, Trevor S.; Carpenter, Donald D.

    2009-01-01

    The purpose of this paper is to validate the use of a modified Theory of Planned Behavior (TPB) for predicting undergraduate student cheating. Specifically, we administered a survey assessing how the TPB relates to cheating along with a measure of moral reasoning (DIT- 2) to 527 undergraduate students across three institutions; and analyzed the…

  13. Comments on model validation

    International Nuclear Information System (INIS)

    The paper points out the importance and usefulness of recognizing the separate roles of processes and geometric structures in predictive modeling of the performance of a nuclear waste repository or underground injection disposal of toxic wastes. Based on this a validation procedure is proposed. Furthermore, two stages and three elements of validation are described and discussed. Finally, comments are made on the choice of measurables to be used to compare modeling results and field data in the validation procedure. 8 refs

  14. Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings

    Science.gov (United States)

    Bharathan, D.; Parsons, B. K.; Althof, J. A.

    1988-10-01

    The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations.

  15. Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.; Parsons, B.K.; Althof, J.A.

    1988-10-01

    The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations. 33 refs., 69 figs., 38 tabs.

  16. Assessment of the structural validity of the domestic violence healthcare providers’ survey questionnaire using a Nigerian sample

    OpenAIRE

    Stephen Lawoko; Ime Akpan John

    2010-01-01

    Abstract: Background: There has been increased advocacy to involve healthcare providers in the prevention of intimate partner violence (IPV) through screening for it in healthcare. Yet, only one in ten providers screen for IPV, suggesting barriers. Understanding the readiness of healthcare providers to screen for IPV is therefore paramount. The Domestic Violence Healthcare Provider Survey Scales (DVHPSS) is a previously validated, comprehensive scale to study readiness of healthcare providers...

  17. Validation of mechanical models for reinforced concrete structures: Presentation of the French project 'Benchmark des Poutres de la Rance'

    Energy Technology Data Exchange (ETDEWEB)

    L' Hostis, V. [Laboratoire d' Etude du Comportement des Betons et des Argiles, CEA Saclay (France); Brunet, C. [EDF/SEPTEN, Villeurbanne (France); Poupard, O. [Laboratoire Pierre Sue, CNRS/CEA Saclay (France)]|[Laboratoire d' Etude du Comportement des Betons et des Argiles, CEA Saclay (France); Petre-Lazar, I. [EDF/DRD/MMC (France)

    2006-07-01

    Several ageing models are available for the prediction of the mechanical consequences of rebar corrosion. They are used for service life prediction of reinforced concrete structures. Concerning corrosion diagnosis of reinforced concrete, some Non Destructive Testing (NDT) tools have been developed, and have been in use for some years. However, these developments require validation on existing concrete structures. The French project 'Benchmark des Poutres de la Rance' contributes to this aspect. It has two main objectives: (i) validation of mechanical models to estimate the influence of rebar corrosion on the load bearing capacity of a structure, (ii) qualification of the use of the NDT results to collect information on steel corrosion within reinforced-concrete structures. Ten French and European institutions from both academic research laboratories and industrial companies contributed during the years 2004 and 2005. This paper presents the project that was divided into several work packages: (i) the reinforced concrete beams were characterized from non-destructive testing tools, (ii) the mechanical behaviour of the beams was experimentally tested, (iii) complementary laboratory analysis were performed and (iv) finally numerical simulations results were compared to the experimental results obtained with the mechanical tests. (authors)

  18. Integral Airframe Structures (IAS): Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs

    Science.gov (United States)

    Munroe, J.; Wilkins, K.; Gruber, M.; Domack, Marcia S. (Technical Monitor)

    2000-01-01

    The Integral Airframe Structures (IAS) program investigated the feasibility of using "integrally stiffened" construction for commercial transport fuselage structure. The objective of the program was to demonstrate structural performance and weight equal to current "built-up" structure with lower manufacturing cost. Testing evaluated mechanical properties, structural details, joint performance, repair, static compression, and two-bay crack residual strength panels. Alloys evaluated included 7050-T7451 plate, 7050-T74511 extrusion, 6013-T6511x extrusion, and 7475-T7351 plate. Structural performance was evaluated with a large 7475-T7351 pressure test that included the arrest of a two-bay longitudinal crack, and a measure of residual strength for a two-bay crack centered on a broken frame. Analysis predictions for the two-bay longitudinal crack panel correlated well with the test results. Analysis activity conducted by the IAS team strongly indicates that current analysis tools predict integral structural behavior as accurately as built-up structure. The cost study results indicated that, compared to built-up fabrication methods, high-speed machining structure from aluminum plate would yield a recurring cost savings of 61%. Part count dropped from 78 individual parts on a baseline panel to just 7 parts for machined IAS structure.

  19. Use of alginate beads as carriers for lactic acid bacteria in a structured system and preliminary validation in a meat product.

    Science.gov (United States)

    Corbo, Maria Rosaria; Bevilacqua, Antonio; Speranza, Barbara; Di Maggio, Barbara; Gallo, Mariangela; Sinigaglia, Milena

    2016-01-01

    This paper proposes the microencapsulation into alginate beads of 4 isolates of lactic acid bacteria (Lactobacillus spp.), previously isolated from pork meat. First, the beads were studied in relation to the encapsulation yield (EY), kinetic of cell release in a structured system, and survival throughout bead storage at 4 °C. EY was 93-96% and the survival of the encapsulated microorganisms was variable, with two isolates showing a bacterial population of 6.1-6.9 log cfu/g after 35 days under refrigerated conditions. Thereafter, the paper addressed a preliminary validation in a meat model system, containing salt, nitrites and nitrates, lactose, pepper, and then in a commercial preparation of pork meat. For the validation in pork meat, free cells were used as controls. Cell released from beads were able to achieve a significant acidification; in particular, after 7 days they showed the same results of free cells. PMID:26476507

  20. Computational study and experimental validation of porous structures fabricated by electron beam melting: A challenge to avoid stress shielding

    International Nuclear Information System (INIS)

    In this paper, several diamond non-stochastic lattice structures, fabricated by electron beam melting, were mechanically characterized by compression tests. A finite element model of the structures was developed, obtaining an equation that estimates the elastic modulus of the lattice structure. Finally, the differences between the numerical and the experimental results were analyzed and discussed. - Highlights: • Diamond non-stochastic lattice structures were fabricated by electron beam melting. • Finite element models of the structures were developed. • An inverse relationship between aspect ratio and elastic modulus it is shown. • An equation that estimates the elastic modulus of the structure was obtained. • Differences between the numerical and the experimental results were discussed

  1. Validity and reliability of a structured interview for early detection and risk assessment of parenting and developmental problems in young children: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    van Stel Henk F

    2012-06-01

    Full Text Available Abstract Background Preventive child health care is well suited for the early detection of parenting and developmental problems. However, as far as the younger age group is concerned, there are no validated early detection instruments which cover both the child and its environment. Therefore, we have developed a broad-scope structured interview which assesses parents’ concerns and their need for support, using both the parental perspective and the experience of the child health care nurse: the Structured Problem Analysis of Raising Kids (SPARK. This study reports the psychometric characteristics of the SPARK. Method A cross-sectional study of 2012 18-month-old children, living in Zeeland, a province of the Netherlands. Inter-rater reliability was assessed in 67 children. Convergent validity was assessed by comparing SPARK-domains with domains in self-report questionnaires on child development and parenting stress. Discriminative validity was assessed by comparing different outcomes of the SPARK between groups with different levels of socio-economic status and by performing an extreme-groups comparison. The user experience of both parents and nurses was assessed with the aid of an online survey. Results The response rate was 92.1% for the SPARK. Self-report questionnaires were returned in the case of 66.9% of the remaining 1721 children. There was selective non-reporting: 33.1% of the questionnaires were not returned, covering 65.2% of the children with a high-risk label according to the SPARK (p  Conclusion The SPARK discriminates between children with a high, increased and low risk of parenting and developmental problems. It does so in a reliable way, but more research is needed on aspects of validity and in other populations.

  2. The Scale for Rating the Behavioral Characteristics of Gifted and Talented Students: Study of Factor Structure, Reliability and Validity

    OpenAIRE

    ŞAHİN, Feyzullah

    2014-01-01

    Th is study aims to develop a nomination scale that helps primary class teachers assessthe possible gift ed and talented students in their classes with their behavioral characteristics.Within this scope, validity check and reliability analysis studies were done.Th e study was fulfi lled based on descriptive survey model. As a result of the validitycheck of the Scale for Rating the Behavioral Characteristics of the Gift ed and TalentedStudents (SRBCGTS), it was realized that the gift ed and ta...

  3. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by...

  4. Validation of molecular crystal structures from powder diffraction data with dispersion-corrected density functional theory (DFT-D)

    DEFF Research Database (Denmark)

    van de Streek, Jacco; Neumann, Marcus A

    2014-01-01

    five structures the energy minimizations suggest a higher space-group symmetry. For the 225 SX structures, the only deviations observed upon energy minimization were three minor H-atom related issues. Preferred orientation is the most important cause of problems. A preferred-orientation correction is...

  5. Damage localization map using electromechanical impedance spectrums and inverse distance weighting interpolation: Experimental validation on thin composite structures

    OpenAIRE

    Cherrier, Olivier; Selva, Pierre; Pommier-Budinger, Valérie; Lachaud, Frédéric; Morlier, Joseph

    2013-01-01

    Piezoelectric sensors are widely used for structure health monitoring technique. In particular, electromechanical impedance techniques give simple and low-cost solutions for detecting damage in composite structures. The purpose of the method proposed in this article is to generate a damage localization map based on both indicators computed from electromechanical impedance spectrums and inverse distance weighting interpolation. The weights for the interpolation have a physical sense and are co...

  6. The Eating Disorder Assessment for DSM-5 (EDA-5): Development and Validation of a Structured Interview for Feeding and Eating Disorders

    Science.gov (United States)

    Sysko, Robyn; Glasofer, Deborah R.; Hildebrandt, Tom; Klimek, Patrycja; Mitchell, James E.; Berg, Kelly C.; Peterson, Carol B.; Wonderlich, Stephen A.; Walsh, B. Timothy

    2016-01-01

    Objective Existing measures for DSM-IV eating disorder diagnoses have notable limitations, and there are important differences between DSM-IV and DSM-5 feeding and eating disorders. This study developed and validated a new semi-structured interview, the Eating Disorders Assessment for DSM-5 (EDA-5). Method Two studies evaluated the utility of the EDA-5. Study 1 compared the diagnostic validity of the EDA-5 to the Eating Disorder Examination (EDE) and evaluated the test-retest reliability of the new measure. Study 2 compared the diagnostic validity of an EDA-5 electronic application (“app”) to clinician interview and self-report assessments. Results In Study 1, the kappa for EDE and EDA-5 eating disorder diagnoses was 0.74 across all diagnoses (n= 64), with a range of κ=0.65 for Other Specified Feeding or Eating Disorder (OSFED)/Unspecified Feeding or Eating Disorder (USFED) to κ=0.90 for Binge Eating Disorder (BED). The EDA-5 test-retest kappa coefficient was 0.87 across diagnoses. For Study 2, clinical interview versus “app” conditions revealed a kappa of 0.83 for all eating disorder diagnoses (n=71). Across individual diagnostic categories, kappas ranged from 0.56 for OSFED/USFED to 0.94 for BN. Discussion High rates of agreement were found between diagnoses by EDA-5 and the EDE, and EDA-5 and clinical interviews. As this study supports the validity of the EDA-5 to generate DSM-5 eating disorders and the reliability of these diagnoses, the EDA-5 may be an option for the assessment of Anorexia Nervosa, Bulimia Nervosa, and BED. Additional research is needed to evaluate the utility of the EDA-5 in assessing DSM-5 feeding disorders. PMID:25639562

  7. Reliability, factor structure, and validity of the German version of the Trauma Symptom Checklist for Children in a sample of adolescents

    Directory of Open Access Journals (Sweden)

    Simone Matulis

    2015-10-01

    Full Text Available Background: The Trauma Symptom Checklist for Children (TSC-C is the most widely used self-report scale to assess trauma-related symptoms in children and adolescents on six clinical scales. The purpose of the present study was to develop a German version of the TSC-C and to investigate its psychometric properties, such as factor structure, reliability, and validity, in a sample of German adolescents. Method: A normative sample of N=583 and a clinical sample of N=41 adolescents with a history of physical or sexual abuse aged between 13 and 21 years participated in the study. Results: The Confirmatory Factor Analysis on the six-factor model (anger, anxiety, depression, dissociation, posttraumatic stress, and sexual concerns with the subdimensions preoccupation and distress revealed acceptable to good fit statistics in the normative sample. One item had to be excluded from the German version of the TSC-C because the factor loading was too low. All clinical scales presented acceptable to good reliability, with Cronbach's α's ranging from .80 to .86 in the normative sample and from .72 to .87 in the clinical sample. Concurrent validity was also demonstrated by the high correlations between the TSC-C scales and instruments measuring similar psychopathology. TSC-C scores reliably differentiated between adolescents with trauma history and those without trauma history, indicating discriminative validity. Conclusions: In conclusion, the German version of the TSC-C is a reliable and valid instrument for assessing trauma-related symptoms on six different scales in adolescents aged between 13 and 21 years.

  8. Comprehensive comparison and experimental validation of band-structure calculation methods in III-V semiconductor quantum wells

    Science.gov (United States)

    Zerveas, George; Caruso, Enrico; Baccarani, Giorgio; Czornomaz, Lukas; Daix, Nicolas; Esseni, David; Gnani, Elena; Gnudi, Antonio; Grassi, Roberto; Luisier, Mathieu; Markussen, Troels; Osgnach, Patrik; Palestri, Pierpaolo; Schenk, Andreas; Selmi, Luca; Sousa, Marilyne; Stokbro, Kurt; Visciarelli, Michele

    2016-01-01

    We present and thoroughly compare band-structures computed with density functional theory, tight-binding, k · p and non-parabolic effective mass models. Parameter sets for the non-parabolic Γ, the L and X valleys and intervalley bandgaps are extracted for bulk InAs, GaAs and InGaAs. We then consider quantum-wells with thickness ranging from 3 nm to 10 nm and the bandgap dependence on film thickness is compared with experiments for In0.53Ga0.47 As quantum-wells. The impact of the band-structure on the drain current of nanoscale MOSFETs is simulated with ballistic transport models, the results provide a rigorous assessment of III-V semiconductor band structure calculation methods and calibrated band parameters for device simulations.

  9. Development of analytical model for evaluating temperature fluctuation in coolant. 11. Validation of the evaluation model for thermally fluid -structure interaction phenomena

    International Nuclear Information System (INIS)

    A numerical evaluation system, which is consisted of four codes, AQUA, DINUS-3, THEMIS and BEMSET has been developed for thermal striping phenomena. To validate the system for the phenomena, thermally fluid - structure interaction analysis was carried out using a existing sodium experiment of parallel impinging jet simulating the outlet region of an LMFBR core. Calculational results on the RMS values of temperature fluctuation, the histograms of temperature amplitudes and frequencies, the auto-power spectral density distributions of temperature fluctuations and the damping characteristics of temperature fluctuations showed good agreement with the measured values under the test conditions of various flow velocity. From the comparisons with the experimental data, it was concluded that the numerical evaluation system is applicable to the evaluation of thermally fluid -structure interaction phenomena related to the thermal striping. (author)

  10. Experimental studies on CSRDM specimen to validate the use of Ritz vectors for the response evaluation of structures subjected to multi-support excitation

    Energy Technology Data Exchange (ETDEWEB)

    Balamonica, K.; Ramamohan Rao, A. [AcSIR, CSIR-SERC (India); Nimala Sundaran, M.; Chellapandi, P. [IGCAR, DAE (India); Gopalakrishnan, N., E-mail: ng@serc.res.in [AcSIR, CSIR-SERC (India)

    2015-02-15

    Highlights: • Ritz vector is used for the first time to analyze multi-support excitation problem. • Efficiency of Ritz vector over Eigen vector is studied. • Effect of spatial variation of ground motion in the responses are analyzed. • Experimental testing on CSRDM rod for multi-support excitation has been carried out. • The numerical formulation and their results have been compared with experimental results. - Abstract: The control and safety rod drive mechanism is a classic example of a multiply supported and differentially excited structure as it receives varying inputs at each of its supports as they are connected at different parts of a building. The responses of such systems are conventionally computed using pseudo-static method in which the dynamic component is evaluated by time history analysis, response spectrum method or modal analysis. In the present work the dynamic components are evaluated by using Ritz vectors and are compared with the conventional methods namely time history analysis and modal analysis. The usage of Ritz vectors as an alternative for conventional modal vectors has been validated through an experiment conducted on a control and safety rod drive mechanism (CSRDM) subjected to differential input motion. The validation of the code developed for this purpose is carried out for a bridge structure.

  11. Postpartum Bonding Disorder: Factor Structure, Validity, Reliability and a Model Comparison of the Postnatal Bonding Questionnaire in Japanese Mothers of Infants

    Directory of Open Access Journals (Sweden)

    Yukiko Ohashi

    2016-08-01

    Full Text Available Negative attitudes of mothers towards their infant is conceptualized as postpartum bonding disorder, which leads to serious health problems in perinatal health care. However, its measurement still remains to be standardized. Our aim was to examine and confirm the psychometric properties of the Postnatal Bonding Questionnaire (PBQ in Japanese mothers. We distributed a set of questionnaires to community mothers and studied 392 mothers who returned the questionnaires at 1 month after childbirth. Our model was compared with three other models derived from previous studies. In a randomly halved sample, an exploratory factor analysis yielded a three-factor structure: Anger and Restrictedness, Lack of Affection, and Rejection and Fear. This factor structure was cross-validated by a confirmatory factor analysis using the other halved sample. The three subscales showed satisfactory internal consistency. The three PBQ subscale scores were correlated with depression and psychological abuse scores. Their test–retest reliability between day 5 and 1 month after childbirth was measured by intraclass correlation coefficients between 0.76 and 0.83. The Akaike Information Criteria of our model was better than the original four-factor model of Brockington. The present study indicates that the PBQ is a reliable and valid measure of bonding difficulties of Japanese mothers with neonates.

  12. Interrater Reliability and Discriminative Validity of the Structural Elements of the Ayres Sensory Integration® Fidelity Measure©

    OpenAIRE

    May-Benson, Teresa A; Roley, Susanne Smith; Mailloux, Zoe; Parham, L. Diane; Koomar, Jane; Schaaf, Roseann C.; Van Jaarsveld, Annamarie; Cohn, Ellen

    2014-01-01

    Analysis of self-report ratings by 259 occupational therapists from 185 facilities indicates that the Structural Section of the ASIFM has acceptable interrater reliability and significantly differentiates between settings in which therapists reportedly do and do not practice OT—SI.

  13. Detection of Q-Matrix Misspecification Using Two Criteria for Validation of Cognitive Structures under the Least Squares Distance Model

    Science.gov (United States)

    Romero, Sonia J.; Ordoñez, Xavier G.; Ponsoda, Vincente; Revuelta, Javier

    2014-01-01

    Cognitive Diagnostic Models (CDMs) aim to provide information about the degree to which individuals have mastered specific attributes that underlie the success of these individuals on test items. The Q-matrix is a key element in the application of CDMs, because contains links item-attributes representing the cognitive structure proposed for solve…

  14. Complementary numerical–experimental benchmarking for shape optimization and validation of structures subjected to wave and current forces

    DEFF Research Database (Denmark)

    Markus, D.; Ferri, Francesco; Wüchner, R.;

    2015-01-01

    defining a simple test geometry, altered in one design variable only, and by designing the test case such that a two dimensional analysis of the flow fields is possible. The force sensitivities to changes in the geometry are determined both numerically and experimentally for a great bandwidth of different...... load cases. The experiments are carried out in a recirculating wave–current flume while the numerical simulations are based on Computational Fluid Dynamics (CFD). Data is also provided to analyze the effect of wave–current interaction on structural loads. Furthermore, a reference study is carried out......A new benchmark problem is proposed and evaluated targeting fluid related shape optimization problems, motivated by design related ocean engineering tasks. The analyzed test geometry is a bottom mounted, polygonal structure in a channel flow. The aim of the study is to analyze the effect of shape...

  15. Extended criteria and predictors in college admission: Exploring the structure of study success and investigating the validity of domain knowledge

    OpenAIRE

    OLGA KUNINA; OLIVER WILHELM; MAREN FORMAZIN; KATHRIN JONKMANN; ULRICH SCHROEDERS

    2007-01-01

    The utility of aptitude tests and intelligence measures in the prediction of the success in college is one of the empirically best supported results in ability research. However, the structure of the criterion “study success” has not been appropriately investigated so far. Moreover, it remains unclear which aspect of intelligence – fluid intelligence or crystallized intelligence – has the major impact on the prediction. In three studies we have investigated the dimensionality of the criterion...

  16. Control Structure Impact on the Flying Performance of the Multi-Rotor VTOL Platform - Design, Analysis and Experimental Validation

    OpenAIRE

    Roman Czyba; Grzegorz Szafranski

    2013-01-01

    The aim of this research is to examine the different control strategies for the unmanned aerial vehicles (UAV). The control task is formulated as an angular stabilization of the four rotor platform, and also as a tracking problem of chosen state variables. The PID algorithm has been considered in three structures in respect of the optimal control signal applied to the actuators. For better performance of the quadrotor in hover mode the cascade control system has been proposed. The simulation ...

  17. ROK Army manpower force structure validation of organizational (Officer, NCO, and Enlisted Personnel) staffing of an infantry battalion

    OpenAIRE

    Kim, Ki Hwan

    2006-01-01

    This research recommends changes to force ratios of officers, non-commissioned officers (NCOs) and enlisted personnel in Republic of Korea (ROK) Army infantry battalions. The methodology is a Bottom-Up approach that examines unit staffing and supports ROK Defense Reform Plan 2020 (the Reform Plan). The research finds that the ROK Army possesses an excessively personnel centric force structure not suited for the future battlefield. Secondly, the research recommends the revision of force ma...

  18. Subzero temperature chromatography and top-down mass spectrometry for protein higher-order structure characterization: method validation and application to therapeutic antibodies.

    Science.gov (United States)

    Pan, Jingxi; Zhang, Suping; Parker, Carol E; Borchers, Christoph H

    2014-09-17

    Characterization of the higher-order structure and structural dynamics of proteins is crucial for in-depth understanding of their functions. Amide hydrogen/deuterium exchange (HDX), monitored by mass spectrometry (MS), is now a popular technique for measuring protein higher-order structural changes. Although the proteolysis-based HDX-MS approach is most commonly used, the "top-down" approach, which fragments intact proteins directly using electron-based dissociation, is becoming an important alternative and has several advantages. However, the commonly used top-down strategies are direct-infusion based and thus can only be used with volatile buffers. This has meant that the "top-down" approach could not be used for studying proteins under physiological conditions-the very conditions which are often very important for preserving a protein's native structure and function. More complex proteins such as those with disulfide bonds present another challenge. Therefore, there is significant interest in developing novel top-down HDX methods that are applicable to all types of protein samples. In this paper, we show how top-down electron capture dissociation and subzero temperature HPLC can be combined and used for this purpose. This method keeps the back-exchange level as low as 2% and has no limitations in terms of protein type and sample solution conditions. Close to single-residue level protein structural information can be generated. The new method is validated through comparison with NMR data using calmodulin as a model protein. Its capability of determining structural changes in therapeutic antibodies (Herceptin) is also demonstrated. PMID:25152011

  19. Validity of a self-reported diagnosis of depression among participants in a cohort study using the Structured Clinical Interview for DSM-IV (SCID-I

    Directory of Open Access Journals (Sweden)

    Pla Jorge

    2008-06-01

    Full Text Available Abstract Background Depression assessment in population studies is usually based on depressive symptoms scales. However, the use of scales could lead to the choice of an arbitrary cut-off point depending on the sample characteristics and on the patient diagnosis. Thus, the use of a medical diagnosis of depression could be a more appropriate approach. Objective To validate a self-reported physician diagnosis of depression using the Structured Clinical Interview for DSM-IV (SCID-I as Gold Standard and to assess the factors associated to a valid self-reported diagnosis. Methods The SUN Project is a cohort study based on university graduates followed-up through postal questionnaires. The response to the question included in the questionnaire: Have you ever been diagnosed of depression by a physician? was compared to that obtained through the SCID-I applied by a psychiatrist or a clinical psychologist. The percentages of confirmed depression and non-depression were assessed for the overall sample and according to several characteristics. Logistic regression models were fitted to ascertain the association between different factors and a correct classification regarding depression status. Results The percentage of confirmed depression was 74.2%; 95% confidence interval (95% CI = 63.3–85.1. Out of 42 participants who did not report a depression diagnosis in the questionnaire, 34 were free of the disease (%confirmed non-depression = 81.1%; 95% CI = 69.1–92.9. The probability of being a true positive was higher among ex-smokers and non-smokers and among those overweight or obese but the differences were not statistically significant. Conclusion The validity of a self-reported diagnosis of depression in the SUN cohort is adequate. Thus, this question about depression diagnosis could be used in further investigations regarding this disease in this graduate cohort study.

  20. Three-dimensional structure determination of N-(p-Tolyl)-dodecylsulfonamide from powder diffraction data and validation of structure using solid-state NMR spectroscopy.

    Science.gov (United States)

    Rajeswaran, Manju; Blanton, Thomas N; Zumbulyadis, Nicholas; Giesen, David J; Conesa-Moratilla, Carlota; Misture, Scott T; Stephens, Peter W; Huq, Ashfia

    2002-12-01

    The three-dimensional structure, conformation, and packing of molecules in the solid state are crucial components used in the optimization of many technologically useful materials properties. Single-crystal X-ray diffraction is the traditional and most effective method of determining 3-D structures in the solid state. Obtaining single crystals that are sufficiently large and free of imperfections is often laborious, time-consuming, and, occasionally, impossible. The feasibility of an integrated approach to the determination and verification of a complete three-dimensional structure for a medium-sized organic molecule without using single crystals is demonstrated for the case of an organic stabilizer compound N-(p-tolyl)-dodecylsulfonamide. The approach uses a combination of powder XRD data, several computational packages involving Monte Carlo simulations and ab initio quantum mechanical calculations, and experimental solid-state NMR chemical shifts. Structure elucidation of N-(p-tolyl)-dodecylsulfonamide revealed that the Bravais lattice is monoclinic, with cell dimensions of a = 38.773 A, b = 5.507 A, c = 9.509 A, and beta = 86.35 degrees, and a space group of P21/c. PMID:12452721

  1. The French Version of the Screen for Child Anxiety Related Emotional Disorders-Revised (Scared-R: Factor Structure, Convergent and Divergent Validity in a Sample of Teenagers

    Directory of Open Access Journals (Sweden)

    Martine Bouvard

    2013-06-01

    Full Text Available The principal objective of this study is to provide data on the French version of the SCARED-R. This article investigates the factor structure of the French version of the Screen for Child Anxiety Related Emotional Disorders-Revised (SCARED-R and its convergent and divergent validity. 704 normal adolescents aged 10 to 19 years completed the questionnaires in their classrooms. A sub-sample of 595 adolescents also completed an anxiety questionnaire (the French version of the Fear Survey Schedule for Children-Revised, FSSC-R and a depression questionnaire (the French version of the Center for Epidemiological Studies Depression Scale, CES-D. Confirmatory factor analysis of the SCARED-R suggested reasonable fit for the 9-factor model. The comparison of the convergent and divergent validity revealed that the SCARED-R total score and five SCARED-R subscales (SAD, Social Phobia and the three Specific Phobias correlated more strongly with anxiety than depression. The other SCARED-R subscales (GAD, Panic Disorder, OCD and PTSD are positively related to levels of anxiety and depression. Altogether, the French version of the SCARED-R showed reasonable psychometric properties.

  2. Numerical modeling and experimental validation of the acoustic transmission of aircraft's double-wall structures including sound package

    Science.gov (United States)

    Rhazi, Dilal

    In the field of aeronautics, reducing the harmful effects of acoustics constitutes a major concern at the international level and justifies the call for further research, particularly in Canada where aeronautics is a key economic sector, which operates in a context of global competition. Aircraft sidewall structure is usually of a double wall construction with a curved ribbed metallic skin and a lightweight composite or sandwich trim separated by a cavity filled with a noise control treatment. The latter is of a great importance in the transport industry, and continues to be of interest in many engineering applications. However, the insertion loss noise control treatment depends on the excitation of the supporting structure. In particular, Turbulent Boundary Layer is of interest to several industries. This excitation is difficult to simulate in laboratory conditions, given the prohibiting costs and difficulties associated with wind tunnel and in-flight tests. Numerical simulation is the only practical way to predict the response to such excitations and to analyze effects of design changes to the response to such excitation. Another kinds of excitations encountered in industrial are monopole, rain on the Roof and diffuse acoustic field. Deterministic methods can calculate in each point the spectral response of the system. Most known are numerical methods such as finite elements and boundary elements methods. These methods generally apply to the low frequency where modal behavior of the structure dominates. However, the high limit of calculation in frequency of these methods cannot be defined in a strict way because it is related to the capacity of data processing and to the nature of the studied mechanical system. With these challenges in mind, and with limitations of the main numerical codes on the market, the manufacturers have expressed the need for simple models immediately available as early as the stage of preliminary drafts. This thesis represents an attempt

  3. Development, validation and application of a fixed district heating model structure that requires small amounts of input data

    International Nuclear Information System (INIS)

    Highlights: • A fixed model structure for cost-optimisaton studies of DH systems is developed. • A method for approximating heat demands using outdoor temperature data is developed. • Six different Swedish district heating systems are modelled and studied. • The impact of heat demand change on heat and electricity production is examined. • Reduced heat demand leads to less use of fossil fuels and biomass in the modelled systems. - Abstract: Reducing the energy use of buildings is an important part in reaching the European energy efficiency targets. Consequently, local energy systems need to adapt to a lower demand for heating. A 90% of Swedish multi-family residential buildings use district heating (DH) produced in Sweden’s over 400 DH systems, which use different heat production technologies and fuels. DH system modelling results obtained until now are mostly for particular DH systems and cannot be easily generalised. Here, a fixed model structure (FMS) based on linear programming for cost-optimisaton studies of DH systems is developed requiring only general DH system information. A method for approximating heat demands based on local outdoor temperature data is also developed. A scenario is studied where the FMS is applied to six Swedish DH systems and heat demands are reduced due to energy efficiency improvements in buildings. The results show that the FMS is a useful tool for DH system optimisation studies and that building energy efficiency improvements lead to reduced use of fossil fuels and biomass in DH systems. Also, the share of CHP in the production mix is increased in five of the six DH systems when the heat demand is reduced

  4. Structural validity and reliability of the Spanish version of the White Bear Suppression Inventory (WBSI) in a sample of the general Spanish population.

    Science.gov (United States)

    González Rodríguez, Manuel; Avero Delgado, Pedro; Rovella, Anna Teresa; Cubas León, Rosario

    2008-11-01

    This paper introduces the validation of the Spanish adaptation of the White Bear Suppression Inventory (WBSI) by Wegner and Zanakos (1994). A sample of 833 people from the general population completed the WBSI along with other questionnaires. The exploratory factor analysis and the confirmatory factor analysis supported a two-factor solution accounting for 51.8% of the cumulative variance. This structure is comprised of the two following factors: unwanted intrusive thoughts (alpha = .87, r = .70) and actions of distraction and suppression of thoughts (alpha = .80, r = .60). Both internal consistency reliability (alpha = .89) and test-retest reliability (r = .71) showed adequate homogeneity, sound consistency, and stability over time. The results are discussed bearing in mind both isolated factors and the possible relationships of the suppression factor with automatic negative thoughts and insomnia. PMID:18988450

  5. Examining the validity of the Structured Assessment of Violence Risk in Youth (SAVRY) for predicting probation outcomes among adjudicated juvenile offenders.

    Science.gov (United States)

    Childs, Kristina K; Ryals, John; Frick, Paul J; Lawing, Kathryn; Phillippi, Stephen W; Deprato, Debra K

    2013-01-01

    The current study examined the ability of the Structured Assessment of Violence Risk for Youth (SAVRY), a standardized risk assessment instrument, to predict probation outcomes among a sample of 158 adjudicated juvenile offenders placed on probation. Traditionally, the SAVRY has been used to measure violence risk among adolescents after release from custody. More recently, a delinquency risk measure based on SAVRY responses was developed, which could be useful for other types of outcome. This study examined the predictive validity of both summary risk ratings (SRR) for probation outcomes, including the reason for terminating probation and length of time on probation. A number of bivariate analyses and Cox regression models provided preliminary support for the ability of the nonviolent delinquency SRR, and modest support for the violence SRR, to predict probation outcomes. The implications for use of the SAVRY SRRs during juvenile justice system decision-making and recommendations for future research are discussed. PMID:23606362

  6. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples.

    Science.gov (United States)

    Zheng, Lijun; Goldberg, Lewis R; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2008-11-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject samples. The reliabilities of the five factors were quite high except for the 50-item measure of Agreeableness. The part-whole correlations between the 100-item and 50-item factors were high, as were the factor congruence coefficients between the heterosexual and the homosexual samples. Both versions of the IPIP Big-Five factor markers were strongly correlated with the scales from the Big Five Inventory (BFI: John, Donahue & Kentle, 1991), thus providing some concurrent validation in a Chinese context. PMID:20383283

  7. One DOF mechanism for the mechanical harvest of vines in an arbor structure and the validation of the acceleration of grape berry harvesting

    Science.gov (United States)

    Penisi, Osvaldo; Bocca, José; Aguilar, Horacio; Bocca, Pedro

    2015-09-01

    In the mechanized harvest of vines, grape berries are detached through the vibration to the structure supporting the clusters. According to the kind of guide selected, the clusters require one or two vibration directions in the structure. For guiding in parral structures, vibration is necessary in two directions or planes: One perpendicular to the other. The guide branches producing the clusters develop in these planes, and the guiding is called H-guiding. Mechanism theory indicates that a mechanism has as many degrees of freedom as its actuators, and an actuator is needed to achieve a certain vibration. Having the smallest number of possible actuators is beneficial in reducing moving parts and achieving more compact and easily controllable mechanisms. In this case, a single degree-of-freedom mechanism is proposed. It is capable of generating vibrations on two planes: One perpendicular to the other. This mechanism is the sum of two link mechanisms on perpendicular planes with a common outlet located at the output rod of the mechanism where the actuator is found. As the distance between the soil and the elements containing the clusters is not constant, a system has been designed to measure the accelerations at the bars and the rocker to validate the acceleration values that detach the grape berries in a prototype in a lab experiment, to ensure that the acceleration needed for pulling the grape berries are produced at any contact point of the bar.

  8. Development of a comprehensive, validated pharmacophore hypothesis for anthrax toxin lethal factor (LF) inhibitors using genetic algorithms, Pareto scoring, and structural biology.

    Science.gov (United States)

    Chiu, Ting-Lan; Amin, Elizabeth A

    2012-07-23

    Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. The anthrax toxin lethal factor (LF), an 89-kDa zinc hydrolase secreted by the bacilli, is the toxin component chiefly responsible for pathogenesis and has been a popular target for rational and structure-based drug design. Although hundreds of small-molecule compounds have been designed to target the LF active site, relatively few reported inhibitors have exhibited activity in cell-based assays, and no LF inhibitor is currently available to treat or prevent anthrax. This study presents a new pharmacophore map assembly, validated by experiment, designed to rapidly identify and prioritize promising LF inhibitor scaffolds from virtual compound libraries. The new hypothesis incorporates structural information from all five available LF enzyme-inhibitor complexes deposited in the Protein Data Bank (PDB) and is the first LF pharmacophore map reported to date that includes features representing interactions involving all three key subsites of the LF catalytic binding region. In a wide-ranging validation study on all 546 compounds for which published LF biological activity data exist, this model displayed strong selectivity toward nanomolar-level LF inhibitors, successfully identifying 72.1% of existing nanomolar-level compounds in an unbiased test set, while rejecting 100% of weakly active (>100 μM) compounds. In addition to its capabilities as a database searching tool, this comprehensive model points to a number of key design principles and previously unidentified ligand-receptor interactions that are likely to influence compound potency. PMID:22697455

  9. Validation of the CQUAD4 element for vibration and shock analysis of thin laminated composite plate structure

    Science.gov (United States)

    Lesar, Douglas E.

    1992-01-01

    The performance of the NASTRAN CQUAD4 membrane and plate element in the analysis of undamped natural vibration modes of thin fiber reinforced composite plates was evaluated. The element provides natural frequency estimates that are comparable in accuracy to alternative formulations, and, in most cases, deviate by less than 10 percent from experimentally measured frequencies. The predictions lie within roughly equal accuracy bounds for the two material types treated (GFRP and CFRP), and for the ply layups considered (unidirectional, cross-ply, and angle-ply). Effective elastic lamina moduli had to be adjusted for fiber volume fraction to attain this level of frequency. The lumped mass option provides more accurate frequencies than the consistent mass option. This evaluation concerned only plates with L/t ratios on the order of 100 to 150. Since the CQUAD4 utilizes first-order corrections for transverse laminate shear stiffness, the element should provide useful frequency estimates for plate-like structures with lower L/t. For plates with L/t below 20, consideration should be given to idealizing with 3-D solid elements. Based on the observation that natural frequencies and mode shapes are predicted with acceptable engineering accuracy, it is concluded that CQUAD4 should be a useful and accurate element for transient shock and steady state vibration analysis of naval ship

  10. The Herdecke questionnaire on quality of life (HLQ): Validation of factorial structure and development of a short form within a naturopathy treated in-patient collective

    Science.gov (United States)

    Ostermann, Thomas; Büssing, Arndt; Beer, Andre-Michael; Matthiessen, Peter F

    2005-01-01

    Background Quality of life (QoL) of patients has become a central evaluation parameter that also acts as an aid for decisions related to treatment strategies particularly for patients with chronic illnesses. In Germany, one of the newer instruments attempting to measure distinct QoL aspects is the "Herdecke Questionnaire for Quality of Life" (HLQ). In this study, we aimed to validate the HLQ with respect to its factorial structure, and to develop a short form. The validation has been carried out in relation to other questionnaires including the SF-36 Health Survey, the Mood-Scale Bf-S, the Giessen Physical Complaints Questionnaire GBB-24 and McGill's Pain Perception Scale SES. Methods Data for this study derived from a model project on the treatment of patients using naturopathy methods in Blankenstein Hospital, Hattingen. In total, 2,461 patients between the ages of 16 and 92 years (mean age: 58.0 ± 13.4 years) were included in this study. Most of the patients (62%) suffered from rheumatic diseases. Factorial validation of the HLQ, it's reliability and external consistency analysis and the development of a short form were carried out using the SPSS software. Results Structural analysis of the HLQ-items pointed to a 6-factor model. The internal consistency of both the long and the short version is excellent (Cronbach's α is 0.935 for the HLQ-L and 0.862 for the HLQ-S). The highest reliability in the HLQ-L was obtained for the "Initiative Power and Interest" scale, the lowest for the 2-item scales "Digestive Well-Being" and the "Physical Complaints". However, the scales found by factor analysis herein were only in part congruent with the original 5-scale model which was approved a multitrait analysis approach. The new instrument shows good correlations with several scales of other relevant QoL instruments. The scales "Initiative Power and Interest", "Social Interaction", "Mental Balance", "Motility", "Physical Complaints", "Digestive Well-Being" sufficiently

  11. The Herdecke questionnaire on quality of life (HLQ: Validation of factorial structure and development of a short form within a naturopathy treated in-patient collective

    Directory of Open Access Journals (Sweden)

    Beer Andre-Michael

    2005-07-01

    Full Text Available Abstract Background Quality of life (QoL of patients has become a central evaluation parameter that also acts as an aid for decisions related to treatment strategies particularly for patients with chronic illnesses. In Germany, one of the newer instruments attempting to measure distinct QoL aspects is the "Herdecke Questionnaire for Quality of Life" (HLQ. In this study, we aimed to validate the HLQ with respect to its factorial structure, and to develop a short form. The validation has been carried out in relation to other questionnaires including the SF-36 Health Survey, the Mood-Scale Bf-S, the Giessen Physical Complaints Questionnaire GBB-24 and McGill's Pain Perception Scale SES. Methods Data for this study derived from a model project on the treatment of patients using naturopathy methods in Blankenstein Hospital, Hattingen. In total, 2,461 patients between the ages of 16 and 92 years (mean age: 58.0 ± 13.4 years were included in this study. Most of the patients (62% suffered from rheumatic diseases. Factorial validation of the HLQ, it's reliability and external consistency analysis and the development of a short form were carried out using the SPSS software. Results Structural analysis of the HLQ-items pointed to a 6-factor model. The internal consistency of both the long and the short version is excellent (Cronbach's α is 0.935 for the HLQ-L and 0.862 for the HLQ-S. The highest reliability in the HLQ-L was obtained for the "Initiative Power and Interest" scale, the lowest for the 2-item scales "Digestive Well-Being" and the "Physical Complaints". However, the scales found by factor analysis herein were only in part congruent with the original 5-scale model which was approved a multitrait analysis approach. The new instrument shows good correlations with several scales of other relevant QoL instruments. The scales "Initiative Power and Interest", "Social Interaction", "Mental Balance", "Motility", "Physical Complaints", "Digestive Well

  12. Creating space for citizenship: The impact of group structure on validating the voices of people with dementia.

    Science.gov (United States)

    Wiersma, Elaine C; O'Connor, Deborah L; Loiselle, Lisa; Hickman, Kathy; Heibein, Bill; Hounam, Brenda; Mann, Jim

    2016-05-01

    Recently, there has been increasing attention given to finding ways to help people diagnosed with dementia 'live well' with their condition. Frequently however, the attention has been placed on the family care partner as the foundation for creating a context that supports the person with dementia to live well. A recent participatory action research (PAR) study highlighted the importance of beginning to challenge some of the assumptions around how best to include family, especially within a context of supporting citizenship. Three advisory groups consisting of 20 people with dementia, 13 care partners, and three service providers, were set up in three locations across Canada to help develop a self-management program for people with dementia. The hubs met monthly for up to two years. One of the topics that emerged as extremely important to consider in the structuring of the program revolved around whether or not these groups should be segregated to include only people with dementia. A thematic analysis of these ongoing discussions coalesced around four inter-related themes: creating safe spaces; maintaining voice and being heard; managing the balancing act; and the importance of solidarity Underpinning these discussions was the fifth theme, recognition that 'one size doesn't fit all'. Overall an important finding was that the presence of family care-partners could have unintended consequences in relation to creating the space for active citizenship to occur in small groups of people with dementia although it could also offer some opportunities. The involvement of care partners in groups with people with dementia is clearly one that is complex without an obvious answer and dependent on a variety of factors to inform a solution, which can and should be questioned and revisited. PMID:27170590

  13. Variable friction device for structural control based on duo-servo vehicle brake: Modeling and experimental validation

    Science.gov (United States)

    Cao, Liang; Downey, Austin; Laflamme, Simon; Taylor, Douglas; Ricles, James

    2015-07-01

    Supplemental damping can be used as a cost-effective method to reduce structural vibrations. In particular, passive systems are now widely accepted and have numerous applications in the field. However, they are typically tuned to specific excitations and their performances are bandwidth-limited. A solution is to use semi-active devices, which have shown to be capable of substantially enhanced mitigation performance. The authors have recently proposed a new type of semi-active device, which consists of a variable friction mechanism based on a vehicle duo-servo drum brake, a mechanically robust and reliable technology. The theoretical performance of the proposed device has been previously demonstrated via numerical simulations. In this paper, we further the understanding of the device, termed Modified Friction Device (MFD) by fabricating a small scale prototype and characterizing its dynamic behavior. While the dynamics of friction is well understood for automotive braking technology, we investigate for the first time the dynamic behavior of this friction mechanism at low displacements and velocities, in both forward and backward directions, under various hydraulic pressures. A modified 3-stage dynamic model is introduced. A LuGre friction model is used to characterize the friction zone (Stage 1), and two pure stiffness regions to characterize the dynamics of the MFD once the rotation is reversed and the braking shoes are sticking to the drum (Stage 2) and the rapid build up of forces once the shoes are held by the anchor pin (Stage 3). The proposed model is identified experimentally by subjecting the prototype to harmonic excitations. It is found that the proposed model can be used to characterize the dynamics of the MFD, and that the largest fitting error arises at low velocity under low pressure input. The model is then verified by subjecting the MFD to two different earthquake excitations under different pressure inputs. The model is capable of tracking the

  14. Improved cross validation of a static ubiquitin structure derived from high precision residual dipolar couplings measured in a drug-based liquid crystalline phase.

    Science.gov (United States)

    Maltsev, Alexander S; Grishaev, Alexander; Roche, Julien; Zasloff, Michael; Bax, Ad

    2014-03-12

    The antibiotic squalamine forms a lyotropic liquid crystal at very low concentrations in water (0.3-3.5% w/v), which remains stable over a wide range of temperature (1-40 °C) and pH (4-8). Squalamine is positively charged, and comparison of the alignment of ubiquitin relative to 36 previously reported alignment conditions shows that it differs substantially from most of these, but is closest to liquid crystalline cetyl pyridinium bromide. High precision residual dipolar couplings (RDCs) measured for the backbone (1)H-(15)N, (15)N-(13)C', (1)H(α)-(13)C(α), and (13)C'-(13)C(α) one-bond interactions in the squalamine medium fit well to the static structural model previously derived from NMR data. Inclusion into the structure refinement procedure of these RDCs, together with (1)H-(15)N and (1)H(α)-(13)C(α) RDCs newly measured in Pf1, results in improved agreement between alignment-induced changes in (13)C' chemical shift, (3)JHNHα values, and (13)C(α)-(13)C(β) RDCs and corresponding values predicted by the structure, thereby validating the high quality of the single-conformer structural model. This result indicates that fitting of a single model to experimental data provides a better description of the average conformation than does averaging over previously reported NMR-derived ensemble representations. The latter can capture dynamic aspects of a protein, thus making the two representations valuable complements to one another. PMID:24568736

  15. Validation of informal learning

    OpenAIRE

    Galanis, Nikolaos; Mayol Sarroca, Enric; Alier Forment, Marc; García Peñalvo, Francisco José

    2014-01-01

    In this paper, we describe our PhD research proposal for the Education in the Knowledge Society program of the University of Salamanca. Our research centers on defining a framework for structuring and validating an individual's informal learning in order to be able to represent the competences gained through informal means, alongside their formal curriculum

  16. Determination of Protein Backbone Structures from Residual Dipolar Couplings

    OpenAIRE

    Prestegard, J H; Mayer, K. L.; Valafar, H.; Benison, G. C.

    2005-01-01

    There are a number of circumstances where a focus on determination of the backbone structure of a protein, as opposed to a complete all-atom structure, may be appropriate. This is particularly the case for structures determined as a part of a structural genomics initiative where computational modeling of many sequentially related structures from the backbone of a single family representative is anti...

  17. Alignment validation

    CERN Document Server

    Golling, T

    2007-01-01

    The four experiments, ALICE, ATLAS, CMS and LHCb are currently under construction at CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector and the muon system requires an accurate alignment of all detector elements. Alignment information is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.

  18. SANSMIC Validation.

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Paula D.; Rudeen, David Keith; Lord, David

    2014-08-01

    SANSMIC is solution mining software that was developed and utilized by SNL in its role as geotechnical advisor to the US DOE SPR for planning purposes. Three SANSMIC leach modes - withdrawal, direct, and reverse leach - have been revalidated with multiple test cases for each mode. The withdrawal mode was validated using high quality data from recent leach activity while the direct and reverse modes utilized data from historical cavern completion reports. Withdrawal results compared very well with observed data, including the location and size of shelves due to string breaks with relative leached volume differences ranging from 6 - 10% and relative radius differences from 1.5 - 3%. Profile comparisons for the direct mode were very good with relative leached volume differences ranging from 6 - 12% and relative radius differences from 5 - 7%. First, second, and third reverse configurations were simulated in order to validate SANSMIC over a range of relative hanging string and OBI locations. The first-reverse was simulated reasonably well with relative leached volume differences ranging from 1 - 9% and relative radius differences from 5 - 12%. The second-reverse mode showed the largest discrepancies in leach profile. Leached volume differences ranged from 8 - 12% and relative radius differences from 1 - 10%. In the third-reverse, relative leached volume differences ranged from 10 - 13% and relative radius differences were ~4 %. Comparisons to historical reports were quite good, indicating that SANSMIC is essentially the same as documented and validated in the early 1980's.

  19. What Facilitates the Delivery of Citizen-Centric EGovernment Services in Developing Countries: Model Development and Validation Through Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Yousef Elsheikh

    2014-02-01

    Full Text Available Yet, existing research on the delivery of citizen-centric e-government services in developing countries is still lacking explanatory power for the following reasons: 1 focus either on the supply-side of these services, or on the demand-side separately, thus there is no enough research on the integration between them, and 2 focus on the results of previous research, thus ignoring the development of theories fit the new context under investigation by understanding the relationship between the implementation of ICT and social structures in the same context. This study aims to fill these gaps by employing a holistic approach to enable in-depth understanding and gain valuable insights for success factors in the delivery of citizencentric e-government services from multiple perspectives, and in the real context of one of the Arab countries, namely Jordan. This would reduce the gap between strategies and government policies on the one hand, and the perceptions of citizens on the other hand about the determinants of the delivery of citizen-centric e-government services in developing countries, allowing a better understanding of citizens' needs and priorities that must be taken into account by those governments in order to ensure the success of those services on a large scale. This study is part of a two-phase research aims to propose an integrated model of success factors in the delivery of citizen centric e-government services and then validate it in the context of developing countries in general and Jordan in particular. The first phase, which is beyond the scope of this study, employs grounded theory method to develop a research model, as well as survey instruments necessary to validate it. The second phase, which is within the scope of this study, employs survey questionnaire method to validate the research model by using multivariate and structural equation modeling (SEM. The results show that factors such as the perception of ease of use as well

  20. The DUNDRUM Quartet: validation of structured professional judgement instruments DUNDRUM-3 assessment of programme completion and DUNDRUM-4 assessment of recovery in forensic mental health services

    Directory of Open Access Journals (Sweden)

    McDonnell Kim

    2011-07-01

    Full Text Available Abstract Background Moving a forensic mental health patient from one level of therapeutic security to a lower level or to the community is influenced by more than risk assessment and risk management. We set out to construct and validate structured professional judgement instruments for consistency and transparency in decision making Methods Two instruments were developed, the seven-item DUNDRUM-3 programme completion instrument and the six item DUNDRUM-4 recovery instrument. These were assessed for all 95 forensic patients at Ireland's only forensic mental health hospital. Results The two instruments had good internal consistency (Cronbach's alpha 0.911 and 0.887. Scores distinguished those allowed no leave or accompanied leave from those with unaccompanied leave (ANOVA F = 38.1 and 50.3 respectively, p Conclusions The DUNDRUM-3 programme completion items distinguished significantly between levels of therapeutic security while the DUNDRUM-4 recovery items consistently distinguished those given unaccompanied leave outside the hospital and those in the lowest levels of therapeutic security. This data forms the basis for a prospective study of outcomes now underway.

  1. The DUNDRUM Quartet: validation of structured professional judgement instruments DUNDRUM-3 assessment of programme completion and DUNDRUM-4 assessment of recovery in forensic mental health services.

    LENUS (Irish Health Repository)

    O'Dwyer, Sarah

    2011-07-03

    Abstract Background Moving a forensic mental health patient from one level of therapeutic security to a lower level or to the community is influenced by more than risk assessment and risk management. We set out to construct and validate structured professional judgement instruments for consistency and transparency in decision making Methods Two instruments were developed, the seven-item DUNDRUM-3 programme completion instrument and the six item DUNDRUM-4 recovery instrument. These were assessed for all 95 forensic patients at Ireland\\'s only forensic mental health hospital. Results The two instruments had good internal consistency (Cronbach\\'s alpha 0.911 and 0.887). Scores distinguished those allowed no leave or accompanied leave from those with unaccompanied leave (ANOVA F = 38.1 and 50.3 respectively, p < 0.001). Scores also distinguished those in acute\\/high security units from those in medium or in low secure\\/pre-discharge units. Each individual item distinguished these levels of need significantly. The DUNDRUM-3 and DUNDRUM-4 correlated moderately with measures of dynamic risk and with the CANFOR staff rated unmet need (Spearman r = 0.5, p < 0.001). Conclusions The DUNDRUM-3 programme completion items distinguished significantly between levels of therapeutic security while the DUNDRUM-4 recovery items consistently distinguished those given unaccompanied leave outside the hospital and those in the lowest levels of therapeutic security. This data forms the basis for a prospective study of outcomes now underway.

  2. Investigation of V and V process for thermal fatigue issue in a sodium cooled fast reactor – Application of uncertainty quantification scheme in verification and validation with fluid-structure thermal interaction problem in T-junction piping system

    International Nuclear Information System (INIS)

    Highlights: • Outline of numerical simulation code MUGTHES for fluid-structure thermal interaction was described. • The grid convergence index (GCI) method was applied according to the ASME V and V-20 guide. • Uncertainty of MUGTHES can be successfully quantified for thermal-hydraulic problems and unsteady heat conduction problems in the structure. • Validation for fluid-structure thermal interaction problem in a T-junction piping system was well conducted. - Abstract: Thermal fatigue caused by thermal mixing phenomena is one of the most important issues in design and safety assessment of fast breeder reactors. A numerical simulation code MUGTHES consisting of two calculation modules for unsteady thermal-hydraulics analysis and unsteady heat conduction analysis in structure has been developed to predict thermal mixing phenomena and to estimate thermal response of structure under the thermal interaction between fluid and structure fields. Although verification and validation (V and V) of MUGTHES has been required, actual procedure for uncertainty quantification is not fixed yet. In order to specify an actual procedure of V and V, uncertainty quantifications with the grid convergence index (GCI) estimation according to the existing guidelines were conducted in fundamental laminar flow problems for the thermal-hydraulics analysis module, and also uncertainty for the structure heat conduction analysis module and conjugate heat transfer model was quantified in comparison with the theoretical solutions of unsteady heat conduction problems. After the verification, MUGTHES was validated for a practical fluid-structure thermal interaction problem in T-junction piping system compared with measured results of velocity and temperatures of fluid and structure. Through the numerical simulations in the verification and validation, uncertainty of the code was successfully estimated and applicability of the code to the thermal fatigue issue was confirmed

  3. Validation through Understanding Test-Taking Strategies: An Illustration With the CELPIP-General Reading Pilot Test Using Structural Equation Modeling

    Science.gov (United States)

    Wu, Amery D.; Stone, Jake E.

    2016-01-01

    This article explores an approach for test score validation that examines test takers' strategies for taking a reading comprehension test. The authors formulated three working hypotheses about score validity pertaining to three types of test-taking strategy (comprehending meaning, test management, and test-wiseness). These hypotheses were…

  4. Predictive validity of measurements of clinical competence using the team objective structured bedside assessment (TOSBA): assessing the clinical competence of final year medical students.

    LENUS (Irish Health Repository)

    Meagher, Frances M

    2009-11-01

    The importance of valid and reliable assessment of student competence and performance is gaining increased recognition. Provision of valid patient-based formative assessment is an increasing challenge for clinical teachers in a busy hospital setting. A formative assessment tool that reliably predicts performance in the summative setting would be of value to both students and teachers.

  5. Enhanced XML Validation Using SRML

    Directory of Open Access Journals (Sweden)

    Miklos Kalman

    2013-10-01

    Full Text Available Data validation is becoming more and more important with the ever-growing amount of data being consumed and transmitted by systems over the Internet. It is important to ensure that the data being sent is valid as it may contain entry errors, which may be consumed by different systems causing further errors. XML has become the defacto standard for data transfer. The XML Schema Definition language (XSD was created to help XML structural validation and provide a schema for data type restrictions, however it does not allow for more complex situations. In this article we introduce a way to provide rule based XML validation and correction through the extension and improvement of our SRML metalanguage. We also explore the option of applying it in a database as a trigger for CRUD operations allowing more granular dataset validation on an atomic level allowing for more complex dataset record validation rules.

  6. High-resolution noise substitution to measure overfitting and validate resolution in 3D structure determination by single particle electron cryomicroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shaoxia; McMullan, Greg; Faruqi, Abdul R.; Murshudov, Garib N.; Short, Judith M.; Scheres, Sjors H.W.; Henderson, Richard, E-mail: rh15@mrc-lmb.cam.ac.uk

    2013-12-15

    unbiased FSC from the two curves, even when a substantial amount of overfitting is present. The approach is software independent. The user is therefore completely free to use any established method or novel combination of methods, provided the HR-noise test is carried out in parallel. Applying this procedure to cryoEM images of beta-galactosidase shows how overfitting varies greatly depending on the procedure, but in the best case shows no overfitting and a resolution of ∼6 Å. (382 words) - Highlights: • A new method to validate 3D cryoEM maps of biological structures is described. • High-resolution noise substitution is a tool to measure the amount of overfitting of noise in single particle cryoEM. • A reliable, unbiased resolution estimation can be obtained even when some overfitting is present. • Structure of beta-galactosidase at ∼6 Å resolution is determined by cryoEM.

  7. High-resolution noise substitution to measure overfitting and validate resolution in 3D structure determination by single particle electron cryomicroscopy

    International Nuclear Information System (INIS)

    unbiased FSC from the two curves, even when a substantial amount of overfitting is present. The approach is software independent. The user is therefore completely free to use any established method or novel combination of methods, provided the HR-noise test is carried out in parallel. Applying this procedure to cryoEM images of beta-galactosidase shows how overfitting varies greatly depending on the procedure, but in the best case shows no overfitting and a resolution of ∼6 Å. (382 words) - Highlights: • A new method to validate 3D cryoEM maps of biological structures is described. • High-resolution noise substitution is a tool to measure the amount of overfitting of noise in single particle cryoEM. • A reliable, unbiased resolution estimation can be obtained even when some overfitting is present. • Structure of beta-galactosidase at ∼6 Å resolution is determined by cryoEM

  8. Smoking-related self-efficacy, beliefs, and intention: assessing factorial validity and structural relationships in 9 th–12th grade current smokers in Texas

    OpenAIRE

    Sterling, Kymberle Landrum; Diamond, Pamela M.; Mullen, Patricia Dolan; Pallonen, Unto; Ford, Kentya H.; McAlister, Alfred L

    2006-01-01

    Smoking-related self-efficacy and beliefs about the benefits of smoking are consistently related to intention to continue smoking, a common proximal outcome in youth smoking cessation studies. Some measures of these constructs are used frequently in national and state youth tobacco surveys, despite little evidence of validity for high school smokers. Further, the association of the constructs with intention has not been demonstrated in this group. The factorial validity of the measures and th...

  9. Validation of aerosol and cloud layer structures from the space-borne lidar CALIOP using a ground-based lidar in Seoul, Korea

    Directory of Open Access Journals (Sweden)

    S.-W. Kim

    2008-07-01

    Full Text Available We present initial validation results of the space-borne lidar CALIOP onboard CALIPSO satellite using coincidental observations from a ground-based lidar in Seoul National University (SNU, Seoul, Korea (37.46° N, 126.95° E. We analyze six selected cases between September 2006 and February 2007, including 3 daytime and 3 night-time observations and covering different types of clear and cloudy atmospheric conditions. Apparent scattering ratios calculated from the two lidar measurements of total attenuated backscatter at 532 nm show similar aerosol and cloud layer structures both under cloud-free conditions and in cases of multiple aerosol layers underlying semi-transparent cirrus clouds. Agreement on top and base heights of cloud and aerosol layers is generally within 0.10 km, particularly during night-time. This result confirms that the CALIPSO science team algorithms for the discrimination of cloud and aerosol as well as for the detection of layer top and base altitude provide reliable information in such atmospheric conditions. This accuracy of the planetary boundary layer top height under cirrus cloud appears, however, limited during daytime. Under thick cloud conditions, however, information on the cloud top (bottom height only is reliable from CALIOP (ground-based lidar due to strong signal attenuations. However, simultaneous space-borne CALIOP and ground-based SNU lidar (SNU-L measurements complement each other and can be combined to provide full information on the vertical distribution of aerosols and clouds. An aerosol backscatter-to-extinction ratio (BER estimated from lidar and sunphotometer synergy at the SNU site during the CALIOP overpass is assessed to be 0.023±0.004 sr−1 (i.e. a lidar ratio of 43.2±6.2 sr from CALIOP and 0.027±0.006 sr−1 (37.4±7.2 sr from SNU-L. For aerosols within the planetary boundary layer under cloud-free conditions, the aerosol extinction profiles from both lidars are in

  10. Validation of aerosol and cloud layer structures from the space-borne lidar CALIOP using a ground-based lidar in Seoul, Korea

    Science.gov (United States)

    Kim, S.-W.; Berthier, S.; Raut, J.-C.; Chazette, P.; Dulac, F.; Yoon, S.-C.

    2008-07-01

    We present initial validation results of the space-borne lidar CALIOP onboard CALIPSO satellite using coincidental observations from a ground-based lidar in Seoul National University (SNU), Seoul, Korea (37.46° N, 126.95° E). We analyze six selected cases between September 2006 and February 2007, including 3 daytime and 3 night-time observations and covering different types of clear and cloudy atmospheric conditions. Apparent scattering ratios calculated from the two lidar measurements of total attenuated backscatter at 532 nm show similar aerosol and cloud layer structures both under cloud-free conditions and in cases of multiple aerosol layers underlying semi-transparent cirrus clouds. Agreement on top and base heights of cloud and aerosol layers is generally within 0.10 km, particularly during night-time. This result confirms that the CALIPSO science team algorithms for the discrimination of cloud and aerosol as well as for the detection of layer top and base altitude provide reliable information in such atmospheric conditions. This accuracy of the planetary boundary layer top height under cirrus cloud appears, however, limited during daytime. Under thick cloud conditions, however, information on the cloud top (bottom) height only is reliable from CALIOP (ground-based lidar) due to strong signal attenuations. However, simultaneous space-borne CALIOP and ground-based SNU lidar (SNU-L) measurements complement each other and can be combined to provide full information on the vertical distribution of aerosols and clouds. An aerosol backscatter-to-extinction ratio (BER) estimated from lidar and sunphotometer synergy at the SNU site during the CALIOP overpass is assessed to be 0.023±0.004 sr-1 (i.e. a lidar ratio of 43.2±6.2 sr) from CALIOP and 0.027±0.006 sr-1 (37.4±7.2 sr) from SNU-L. For aerosols within the planetary boundary layer under cloud-free conditions, the aerosol extinction profiles from both lidars are in agreement within about 0.02 km-1. Under semi

  11. Clinical Validation of Atlas-Based Auto-Segmentation of Multiple Target Volumes and Normal Tissue (Swallowing/Mastication) Structures in the Head and Neck

    International Nuclear Information System (INIS)

    Purpose: To validate and clinically evaluate autocontouring using atlas-based autosegmentation (ABAS) of computed tomography images. Methods and Materials: The data from 10 head-and-neck patients were selected as input for ABAS, and neck levels I-V and 20 organs at risk were manually contoured according to published guidelines. The total contouring times were recorded. Two different ABAS strategies, multiple and single subject, were evaluated, and the similarity of the autocontours with the atlas contours was assessed using Dice coefficients and the mean distances, using the leave-one-out method. For 12 clinically treated patients, 5 experienced observers edited the autosegmented contours. The editing times were recorded. The Dice coefficients and mean distances were calculated among the clinically used contours, autocontours, and edited autocontours. Finally, an expert panel scored all autocontours and the edited autocontours regarding their adequacy relative to the published atlas. Results: The time to autosegment all the structures using ABAS was 7 min/patient. No significant differences were observed in the autosegmentation accuracy for stage N0 and N+ patients. The multisubject atlas performed best, with a Dice coefficient and mean distance of 0.74 and 2 mm, 0.67 and 3 mm, 0.71 and 2 mm, 0.50 and 2 mm, and 0.78 and 2 mm for the salivary glands, neck levels, chewing muscles, swallowing muscles, and spinal cord-brainstem, respectively. The mean Dice coefficient and mean distance of the autocontours vs. the clinical contours was 0.8 and 2.4 mm for the neck levels and salivary glands, respectively. For the autocontours vs. the edited autocontours, the mean Dice coefficient and mean distance was 0.9 and 1.6 mm, respectively. The expert panel scored 100% of the autocontours as a “minor deviation, editable” or better. The expert panel scored 88% of the edited contours as good compared with 83% of the clinical contours. The total editing time was 66 min

  12. Clinical Validation of Atlas-Based Auto-Segmentation of Multiple Target Volumes and Normal Tissue (Swallowing/Mastication) Structures in the Head and Neck

    Energy Technology Data Exchange (ETDEWEB)

    Teguh, David N. [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Levendag, Peter C., E-mail: p.levendag@erasmusmc.nl [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Voet, Peter W.J.; Al-Mamgani, Abrahim [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Han Xiao; Wolf, Theresa K.; Hibbard, Lyndon S. [Elekta-CMS Software, Maryland Heights, MO 63043 (United States); Nowak, Peter; Akhiat, Hafid; Dirkx, Maarten L.P.; Heijmen, Ben J.M.; Hoogeman, Mischa S. [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2011-11-15

    Purpose: To validate and clinically evaluate autocontouring using atlas-based autosegmentation (ABAS) of computed tomography images. Methods and Materials: The data from 10 head-and-neck patients were selected as input for ABAS, and neck levels I-V and 20 organs at risk were manually contoured according to published guidelines. The total contouring times were recorded. Two different ABAS strategies, multiple and single subject, were evaluated, and the similarity of the autocontours with the atlas contours was assessed using Dice coefficients and the mean distances, using the leave-one-out method. For 12 clinically treated patients, 5 experienced observers edited the autosegmented contours. The editing times were recorded. The Dice coefficients and mean distances were calculated among the clinically used contours, autocontours, and edited autocontours. Finally, an expert panel scored all autocontours and the edited autocontours regarding their adequacy relative to the published atlas. Results: The time to autosegment all the structures using ABAS was 7 min/patient. No significant differences were observed in the autosegmentation accuracy for stage N0 and N+ patients. The multisubject atlas performed best, with a Dice coefficient and mean distance of 0.74 and 2 mm, 0.67 and 3 mm, 0.71 and 2 mm, 0.50 and 2 mm, and 0.78 and 2 mm for the salivary glands, neck levels, chewing muscles, swallowing muscles, and spinal cord-brainstem, respectively. The mean Dice coefficient and mean distance of the autocontours vs. the clinical contours was 0.8 and 2.4 mm for the neck levels and salivary glands, respectively. For the autocontours vs. the edited autocontours, the mean Dice coefficient and mean distance was 0.9 and 1.6 mm, respectively. The expert panel scored 100% of the autocontours as a 'minor deviation, editable' or better. The expert panel scored 88% of the edited contours as good compared with 83% of the clinical contours. The total editing time was 66 min

  13. xMDFF: molecular dynamics flexible fitting of low-resolution X-ray structures

    International Nuclear Information System (INIS)

    A new real-space refinement method for low-resolution X-ray crystallography is presented. The method is based on the molecular dynamics flexible fitting protocol targeted at addressing large-scale deformations of the search model to achieve refinement with minimal manual intervention. An explanation of the method is provided, augmented by results from the refinement of both synthetic and experimental low-resolution data, including an independent electrophysiological verification of the xMDFF-refined crystal structure of a voltage-sensor protein. X-ray crystallography remains the most dominant method for solving atomic structures. However, for relatively large systems, the availability of only medium-to-low-resolution diffraction data often limits the determination of all-atom details. A new molecular dynamics flexible fitting (MDFF)-based approach, xMDFF, for determining structures from such low-resolution crystallographic data is reported. xMDFF employs a real-space refinement scheme that flexibly fits atomic models into an iteratively updating electron-density map. It addresses significant large-scale deformations of the initial model to fit the low-resolution density, as tested with synthetic low-resolution maps of d-ribose-binding protein. xMDFF has been successfully applied to re-refine six low-resolution protein structures of varying sizes that had already been submitted to the Protein Data Bank. Finally, via systematic refinement of a series of data from 3.6 to 7 Å resolution, xMDFF refinements together with electrophysiology experiments were used to validate the first all-atom structure of the voltage-sensing protein Ci-VSP

  14. Testing of the preliminary OMERACT validation criteria for a biomarker to be regarded as reflecting structural damage endpoints in rheumatoid arthritis clinical trials: the example of C-reactive protein

    DEFF Research Database (Denmark)

    Keeling, Stephanie O; Landewe, Robert; van der Heijde, Desiree;

    2007-01-01

    OBJECTIVE: A list of 14 criteria for guiding the validation of a soluble biomarker as reflecting structural damage endpoints in rheumatoid arthritis (RA) clinical trials was drafted by an international working group after a Delphi consensus exercise. C-reactive protein (CRP), a soluble biomarker...... extensively studied in RA, was then used to test these criteria. Our objectives were: (1) To assess the strength of evidence in support of CRP as a soluble biomarker reflecting structural damage in RA according to the draft validation criteria. (2) To assess the strength of recommendation for inclusion of...... individual criteria in the draft set. METHODS: A systematic literature review was conducted to elicit evidence in support of each specific criterion composing the 14-criteria draft set. A summary of the key literature findings per criterion was presented to both the working group and to participants in a...

  15. Adaptation of the Boundary Violations Scale Developed Based on Structural Family Therapy to the Turkish Context: A Study of Validity and Reliability

    Science.gov (United States)

    Avci, Rasit; Çolakkadioglu, Oguzhan; Öz, Aysegül Sükran; Akbas, Turan

    2015-01-01

    The purpose of this study was to adapt "The Boundary Violations Scale" (Madden et al., 2002), which was created to measure the intergenerational boundary violations in families from the perspective of children, to Turkish and to test the validity and reliability of the Turkish version of this instrument. This instrument was developed…

  16. Miniaturized side-viewing imaging probe for fluorescence lifetime imaging (FLIM): validation with fluorescence dyes, tissue structural proteins and tissue specimens

    Science.gov (United States)

    Elson, D. S.; Jo, J. A.; Marcu, L.

    2007-05-01

    We report a side viewing fibre-based endoscope that is compatible with intravascular imaging and fluorescence lifetime imaging microscopy (FLIM). The instrument has been validated through testing with fluorescent dyes and collagen and elastin powders using the Laguerre expansion deconvolution technique to calculate the fluorescence lifetimes. The instrument has also been tested on freshly excised unstained animal vascular tissues.

  17. Reexamining the Factorial Structure of the Maslach Burnout Inventory for Elementary, Intermediate, and Secondary Teachers: A Cross-Validated Confirmatory Factor Analytic Study.

    Science.gov (United States)

    Byrne, Barbara M.

    The factorial validity of the Maslach Burnout Inventory (MBI) was studied for 2,931 Canadian teachers (48.2% males and 51.8% females) as a single professional group and for subsamples of this group (1,159 elementary school teachers, 388 intermediate school teachers, and 1,384 secondary school teachers). Study participants were full-time teachers…

  18. Validated dynamic flow model

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2011-01-01

    The purpose with this deliverable 2.5 is to use fresh experimental data for validation and selection of a flow model to be used for control design in WP3-4. Initially the idea was to investigate the models developed in WP2. However, in the project it was agreed to include and focus on a additive...... model turns out not to be useful for prediction of the flow. Moreover, standard Box Jenkins model structures and multiple output auto regressive models proves to be superior as they can give useful predictions of the flow....

  19. Validation of aerosol and cloud layer structures from the space-borne lidar CALIOP using a ground-based lidar in Seoul, Korea

    OpenAIRE

    Kim, S.-W.; Berthier, S.; Raut, J.-C.; Chazette, P.; Dulac, F.; Yoon, S. -C

    2008-01-01

    We present initial validation results of the space-borne lidar CALIOP onboard CALIPSO satellite using coincidental observations from a ground-based lidar in Seoul National University (SNU), Seoul, Korea (37.46° N, 126.95° E). We analyze six selected cases between September 2006 and February 2007, including 3 daytime and 3 night-time observations and covering different types of clear and cloudy atmospheric conditions. Apparent scattering ratios calculated from the two lidar mea...

  20. Validating the German Version of the Quality of Relationship Inventory: Confirming the Three-Factor Structure and Report of Psychometric Properties

    OpenAIRE

    Reiner, Iris; Beutel, Manfred; Skaletz, Christian; Brähler, Elmar; Stöbel-Richter, Yve

    2012-01-01

    Research on psychosocial influences such as relationship characteristics has received increased attention in the clinical as well as social-psychological field. Several studies demonstrated that the quality of relationships, in particular with respect to the perceived support within intimate relationships, profoundly affects individuals' mental and physical health. There is, however, a limited choice of valid and internationally known assessments of relationship quality in Germany. We report ...

  1. Clinical assessment of bipolar depression: validity, factor structure and psychometric properties of the Korean version of the Bipolar Depression Rating Scale (BDRS)

    OpenAIRE

    Jung, Young-Eun; Kim, Moon-Doo; Bahk, Won-Myong; Woo, Young Sup; Lee, Jonghun; Jang, Sae-Heon; Won, Seunghee; Min, Kyung Joon; Chung, Sangkeun; Kwon, Young-Joon; Jon, Duk-In; Lee, Kwanghun; Yoon, Bo-Hyun

    2016-01-01

    Background The Bipolar Depression Rating Scale (BDRS) is a scale for assessment of the clinical characteristics of bipolar depression. The primary aims of this study were to describe the development of the Korean version of the BDRS (K-BDRS) and to establish more firmly its psychometric properties in terms of reliability and validity. Methods The study included 141 patients (62 male and 79 female) who had been diagnosed with bipolar disorder, were currently experiencing symptoms of depression...

  2. Nature and Validity of Complex Problem Solving

    OpenAIRE

    Wüstenberg, Sascha

    2013-01-01

    This thesis investigates the nature and validity of complex problem solving (CPS). The main focus lies on analyses of three research questions dealing with CPS’ (1) internal structure, its (2) structural stability combined with comparisons of performance differences across groups, and its (3) construct validity. In previous research, results on CPS’ (1) internal factor structure have been solely based on samples with high cognitive performance, (2) structural stability of CPS across groups ha...

  3. Cross-validation of the factorial structure of the Neighborhood Environment Walkability Scale (NEWS and its abbreviated form (NEWS-A

    Directory of Open Access Journals (Sweden)

    Cerin Ester

    2009-06-01

    Full Text Available Abstract Background The Neighborhood Environment Walkability Scale (NEWS and its abbreviated form (NEWS-A assess perceived environmental attributes believed to influence physical activity. A multilevel confirmatory factor analysis (MCFA conducted on a sample from Seattle, WA showed that, at the respondent level, the factor-analyzable items of the NEWS and NEWS-A measured 11 and 10 constructs of perceived neighborhood environment, respectively. At the census blockgroup (used by the US Census Bureau as a subunit of census tracts level, the MCFA yielded five factors for both NEWS and NEWS-A. The aim of this study was to cross-validate the individual- and blockgroup-level measurement models of the NEWS and NEWS-A in a geographical location and population different from those used in the original validation study. Methods A sample of 912 adults was recruited from 16 selected neighborhoods (116 census blockgroups in the Baltimore, MD region. Neighborhoods were stratified according to their socio-economic status and transport-related walkability level measured using Geographic Information Systems. Participants self-completed the NEWS. MCFA was used to cross-validate the individual- and blockgroup-level measurement models of the NEWS and NEWS-A. Results The data provided sufficient support for the factorial validity of the original individual-level measurement models, which consisted of 11 (NEWS and 10 (NEWS-A correlated factors. The original blockgroup-level measurement model of the NEWS and NEWS-A showed poor fit to the data and required substantial modifications. These included the combining of aspects of building aesthetics with safety from crime into one factor; the separation of natural aesthetics and building aesthetics into two factors; and for the NEWS-A, the separation of presence of sidewalks/walking routes from other infrastructure for walking. Conclusion This study provided support for the generalizability of the individual

  4. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples

    OpenAIRE

    Zheng, Lijun; Goldberg, Lewis R.; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2008-01-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject...

  5. Reappraisal of OMERACT 8 draft validation criteria for a soluble biomarker reflecting structural damage endpoints in rheumatoid arthritis, psoriatic arthritis, and spondyloarthritis

    DEFF Research Database (Denmark)

    Maksymowych, Walter P; Landewé, Robert; Tak, Paul-Peter;

    2009-01-01

    OBJECTIVES: A draft set of criteria for the validation of soluble biomarkers reflecting damage endpoints was proposed at OMERACT 8. At OMERACT 9 we aimed to scrutinize the necessity for each of these criteria according to the objectives of the working group. METHODS: The OMERACT 8 draft criteria...... biomarkers (MMP3, CTX-II, RANKL, OPG, CTX-I) followed by a Delphi consensus exercise addressing the importance of individual criteria and identification of omissions in the draft set. (B) Formal debate as well as group discussion centered on the key arguments for inclusion/exclusion of specific criteria. (C...

  6. Static Validation of XSL Transformations

    DEFF Research Database (Denmark)

    Møller, Anders; Olesen, Mads Østerby; Schwartzbach, Michael Ignatieff

    2007-01-01

    XSL Transformations (XSLT) is a programming language for defining transformations among XML languages. The structure of these languages is formally described by schemas, for example using DTD or XML Schema, which allows individual documents to be validated. However, existing XSLT tools offer no...... static guarantees that, under the assumption that the input is valid relative to the input schema, the output of the transformation is valid relative to the output schema. We present a validation technique for XSLT based on the XML graph formalism introduced in the static analysis of JWIG Web services...... and XACT XML transformations. Being able to provide static guarantees, we can detect a large class of errors in an XSLT stylesheet at the time it is written instead of later when it has been deployed, and thereby provide benefits similar to those of static type checkers for modern programming...

  7. Clinical validity of MR based program for analysis of fluid/brain index of posterior cranial fossa structures in patients with spinocerebellar ataxia

    International Nuclear Information System (INIS)

    Spinocerebellar ataxia type 1 (SCA1) and type 2 (SCA2) belong to the group of neurodegenerative disorders of autosomal dominant inheritance, genetically and clinically heterogeneous, caused by CAG trinucleotide repeat expansion, which leads to productions of protein carrying the abnormal polyglutamine chain (polyQ). Molecular abnormalities cause degenerative changes - atrophy of posterior cranial fossa structures. The clinical symptoms typical of this disorder include progressive gait and limb ataxia, dysarthria, occulomotor disturbances, pyramidal tract and peripheral nerves involvement. The aim of the study is to evaluate the usefulness of a computer program prepared in our department for volumetric measurements of posterior cranial fossa structures (the pons, vermis and cerebellar hemispheres) in a group of SCA patients. MR examinations of 22 patients suffering from SCA were used to calculate the value of fluid/brain index of posterior cranial fossa structures and compared with the results of group of 10 healthy volunteers. The degree of atrophy of posterior cranial fossa structures can be objectively evaluated by special volumetric measurements. We found fluid/brain index (FBI) of posterior cranial fossa structures in group of SCA patients to vary from 0.1411 to 0.3929 (mean 0.2456 SD±0.601). 1. MR-based calculation of fluid/brain index of posterior fossa structures is a valuable tool for morphological assessment of SCA-related changes in brain structures. 2. The presented software enables objective evaluation of the course and stage of posterior fossa structures atrophy. 3. Our self-made computer program to calculate the fluid/brain index of posterior cranial fossa structures is easy to use on a personal computer- it is a good tool in everyday radiological practice. (author)

  8. Testing of the preliminary OMERACT validation criteria for a biomarker to be regarded as reflecting structural damage endpoints in rheumatoid arthritis clinical trials: the example of C-reactive protein

    DEFF Research Database (Denmark)

    Keeling, Stephanie O; Landewe, Robert; van der Heijde, Desiree;

    2007-01-01

    OBJECTIVE: A list of 14 criteria for guiding the validation of a soluble biomarker as reflecting structural damage endpoints in rheumatoid arthritis (RA) clinical trials was drafted by an international working group after a Delphi consensus exercise. C-reactive protein (CRP), a soluble biomarker...... individual criteria in the draft set. METHODS: A systematic literature review was conducted to elicit evidence in support of each specific criterion composing the 14-criteria draft set. A summary of the key literature findings per criterion was presented to both the working group and to participants in a...

  9. Relational visual cluster validity

    OpenAIRE

    Ding, Y.; Harrison, R F

    2007-01-01

    The assessment of cluster validity plays a very important role in cluster analysis. Most commonly used cluster validity methods are based on statistical hypothesis testing or finding the best clustering scheme by computing a number of different cluster validity indices. A number of visual methods of cluster validity have been produced to display directly the validity of clusters by mapping data into two- or three-dimensional space. However, these methods may lose too much information to corre...

  10. Audit Validation Using Ontologies

    Directory of Open Access Journals (Sweden)

    Ion IVAN

    2015-01-01

    Full Text Available Requirements to increase quality audit processes in enterprises are defined. It substantiates the need for assessment and management audit processes using ontologies. Sets of rules, ways to assess the consistency of rules and behavior within the organization are defined. Using ontologies are obtained qualifications that assess the organization's audit. Elaboration of the audit reports is a perfect algorithm-based activity characterized by generality, determinism, reproducibility, accuracy and a well-established. The auditors obtain effective levels. Through ontologies obtain the audit calculated level. Because the audit report is qualitative structure of information and knowledge it is very hard to analyze and interpret by different groups of users (shareholders, managers or stakeholders. Developing ontology for audit reports validation will be a useful instrument for both auditors and report users. In this paper we propose an instrument for validation of audit reports contain a lot of keywords that calculates indicators, a lot of indicators for each key word there is an indicator, qualitative levels; interpreter who builds a table of indicators, levels of actual and calculated levels.

  11. Discourse structures in medical reports--watch out! The generation of referentially coherent and valid text knowledge bases in the MEDSYNDIKATE system.

    Science.gov (United States)

    Hahn, U; Romacker, M; Schulz, S

    1999-01-01

    The automatic analysis of medical narratives currently suffers from neglecting text structure phenomena such as referential relations between discourse units. This has unwarranted effects on the descriptional adequacy of medical knowledge bases automatically generated from texts. The resulting representation bias can be characterized in terms of incomplete, artificially fragmented and referentially invalid knowledge structures. We focus here on four basic types of textual reference relations, viz. pronominal and nominal anaphora, textual ellipsis and metonymy and show how to deal with them in an adequate text parsing device. Since the types of reference relations we discuss show an increasing dependence on conceptual background knowledge, we stress the need for formally grounded, expressive conceptual representation systems for medical knowledge. Our suggestions are based on experience with MEDSYNDIKATE, a medical text knowledge acquisition system designed to properly deal with various sorts of discourse structure phenomena. PMID:10075128

  12. Structural Insight into Tetrameric hTRPV1 from Homology Modeling, Molecular Docking, Molecular Dynamics Simulation, Virtual Screening, and Bioassay Validations

    OpenAIRE

    Feng, Zhiwei; Pearce, Larry V.; Xu, Xiaomeng; Yang, Xiaole; Yang, Peng; Blumberg, Peter M.; Xie, Xiang-Qun

    2015-01-01

    The transient receptor potential vanilloid type 1 (TRPV1) is a heat-activated cation channel protein, which contributes to inflammation, acute and persistent pain. Antagonists of human TRPV1 (hTRPV1) represent a novel therapeutic approach for the treatment of pain. Developing various antagonists of hTRPV1, however, has been hindered by the unavailability of a 3D structure of hTRPV1. Recently, the 3D structures of rat TRPV1 (rTRPV1) in the presence and absence of ligand have been reported as d...

  13. Analysis and experimental validation of the middle-frequency vibro-acoustic coupling property for aircraft structural model based on the wave coupling hybrid FE-SEA method

    Science.gov (United States)

    Yan, Yunju; Li, Pengbo; Lin, Huagang

    2016-06-01

    The finite element (FE) method is suitable for low frequency analysis and the statistical energy analysis (SEA) for high frequency analysis, but the vibro-acoustic coupling analysis at middle frequency, especially with a certain range of uncertainty system, requires some new methods. A hybrid FE-SEA method is proposed in this study and the Monte Carlo method is used to check the hybrid FE-SEA method through the energy response analysis of a beam-plate built-up structure with some uncertainty, and the results show that two kinds of calculation results match well consistently. Taking the advantage of the hybrid FE-SEA method, the structural vibration and the cabin noise field responses under the vibro-acoustic coupling for an aircraft model are numerically analyzed, and, also, the corresponding experiment is carried out to verify the simulated results. Results show that the structural vibration responses at low frequency accord well with the experiment, but the error at high frequency is greater. The error of sound pressure response level in cabin throughout the spectrum is less than 3 dB. The research proves the reliability of the method proposed in this paper. This indicates that the proposed method can overcome the strict limitations of the traditional method for a large complex structure with uncertainty factors, and it can also avoid the disadvantages of solving complex vibro-acoustic system using the finite element method or statistical energy analysis in the middle frequency.

  14. Testing of the OMERACT 8 draft validation criteria for a soluble biomarker reflecting structural damage in rheumatoid arthritis: a systematic literature search on 5 candidate biomarkers

    DEFF Research Database (Denmark)

    Syversen, Silje W; Landewe, Robert; van der Heijde, Désirée;

    2009-01-01

    the importance of each individual criterion; (2) overall strength of evidence in support of each of the 5 candidate biomarkers as reflecting structural damage endpoints in rheumatoid arthritis (RA) and identification of omissions to the criteria set. RESULTS: The search identified 111 articles. The...

  15. Extending Structural Analyses of the Rosenberg Self-Esteem Scale to Consider Criterion-Related Validity: Can Composite Self-Esteem Scores Be Good Enough?

    Science.gov (United States)

    Donnellan, M Brent; Ackerman, Robert A; Brecheen, Courtney

    2016-01-01

    Although the Rosenberg Self-Esteem Scale (RSES) is the most widely used measure of global self-esteem in the literature, there are ongoing disagreements about its factor structure. This methodological debate informs how the measure should be used in substantive research. Using a sample of 1,127 college students, we test the overall fit of previously specified models for the RSES, including a newly proposed bifactor solution (McKay, Boduszek, & Harvey, 2014 ). We extend previous work by evaluating how various latent factors from these structural models are related to a set of criterion variables frequently studied in the self-esteem literature. A strict unidimensional model poorly fit the data, whereas models that accounted for correlations between negatively and positively keyed items tended to fit better. However, global factors from viable structural models had similar levels of association with criterion variables and with the pattern of results obtained with a composite global self-esteem variable calculated from observed scores. Thus, we did not find compelling evidence that different structural models had substantive implications, thereby reducing (but not eliminating) concerns about the integrity of the self-esteem literature based on overall composite scores for the RSES. PMID:26192536

  16. Parsimonious rainfall-runoff model construction supported by time series processing and validation of hydrological extremes - Part 1: Step-wise model-structure identification and calibration approach

    Science.gov (United States)

    Willems, Patrick

    2014-03-01

    Common problems faced by rainfall-runoff modellers are data limitation, model overparameterization and related problems of parameter identifiability. Depending on the application, possible solutions to overcome these problems include the use of parsimonious conceptual models, avoid the use of a fixed pre-defined model conceptualization, but apply a “top-down” or “downward” method to allow the model structure to be adjusted or inferred from available data and field evidence. This paper presents a top-down procedure that starts from a generalized model structure framework that is adjusted in a case-specific parsimonious way. The model-structure building is done in a transparent, step-wise way, where separate parts of the model structure are identified and calibrated based on multiple and non-commensurable information derived from river flow series by means of a number of sequential time series processing tasks. These include separation of the high frequency (e.g., hourly, daily) river flow series into subflows, split of the series in approx. independent quick and slow flow hydrograph periods, and the extraction of independent peak and low flows. The model building and calibration account for the statistical assumptions and requirements on independency and homoscedasticity of the model residuals. Next to identification of the subflow recessions and related routing submodels, equations describing quick and slow runoff sub-responses and soil water storage are derived from the time series data. The method includes testing of the model performance for peak and low flow extremes.

  17. The Structure of Self-Serving Cognitive Distortions: A Validation of the "How I Think" Questionnaire in a Sample of Italian Adolescents

    Science.gov (United States)

    Bacchini, Dario; De Angelis, Grazia; Affuso, Gaetana; Brugman, Daniel

    2016-01-01

    This study aims to investigate the structure of self-serving cognitive distortions (CD), evaluating the psychometric properties of the How I Think Questionnaire in a sample of Italian adolescents. A confirmatory factor analysis supported the distinction between four categories of CD and the use of a single second-order dimension of CD. Reliability…

  18. Validation of Force Fields of Rubber through Glass-Transition Temperature Calculation by Microsecond Atomic-Scale Molecular Dynamics Simulation.

    Science.gov (United States)

    Sharma, Pragati; Roy, Sudip; Karimi-Varzaneh, Hossein Ali

    2016-02-25

    Microsecond atomic-scale molecular dynamics simulation has been employed to calculate the glass-transition temperature (Tg) of cis- and trans-1,4-polybutadiene (PB) and 1,4-polyisoprene (PI). Both all-atomistic and united-atom models have been simulated using force fields, already available in literature. The accuracy of these decade old force fields has been tested by comparing calculated glass-transition temperatures to the corresponding experimental values. Tg depicts the phase transition in elastomers and substantially affects various physical properties of polymers, and hence the reproducibility of Tg becomes very crucial from a thermodynamic point of view. Such validation using Tg also evaluates the ability of these force fields to be used for advanced materials like rubber nanocomposites, where Tg is greatly affected by the presence of fillers. We have calculated Tg for a total of eight systems, featuring all-atom and united-atom models of cis- and trans-PI and -PB, which are the major constituents of natural and synthetic rubber. Tuning and refinement of the force fields has also been done using quantum-chemical calculations to obtain desirable density and Tg. Thus, a set of properly validated force fields, capable of reproducing various macroscopic properties of rubber, has been provided. A novel polymer equilibration protocol, involving potential energy convergence as the equilibration criterion, has been proposed. We demonstrate that not only macroscopic polymer properties like density, thermal expansion coefficient, and Tg but also local structural characteristics like end-to-end distance (R) and radius of gyration (Rg) and mechanical properties like bulk modulus have also been equilibrated using our strategy. Complete decay of end-to-end vector autocorrelation function with time also supports proper equilibration using our strategy. PMID:26836395

  19. Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

    International Nuclear Information System (INIS)

    Purpose: Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE). Methods and Materials: CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independent institutions were autosegmented using SPICE and computational times were recorded. The number of structures autocontoured were 25 for the HN, 7 for the thorax, 3 for the liver, and 6 for the male pelvis regions. Using the clinical contours as reference, autocontours of 22 selected structures were quantitatively evaluated using Dice Similarity Coefficient (DSC) and Mean Slice-wise Hausdorff Distance (MSHD). All 40 autocontours were evaluated by a radiation oncologist from the institution that treated the patients. Results: The mean computational times to autosegment all the structures using SPICE were 3.1 to 11.1 minutes per patient. For the HN region, the mean DSC was >0.70 for all evaluated structures, and the MSHD ranged from 3.2 to 10.0 mm. For the thorax region, the mean DSC was 0.95 for the lungs and 0.90 for the heart, and the MSHD ranged from 2.8 to 12.8 mm. For the liver region, the mean DSC was >0.92 for all structures, and the MSHD ranged from 5.2 to 15.9 mm. For the male pelvis region, the mean DSC was >0.76 for all structures, and the MSHD ranged from 4.8 to 10.5 mm. Out of the 40 autocontoured structures reviews by experts, 25 were scored useful as autocontoured or with minor edits for at least 90% of the patients and 33 were scored useful autocontoured or with minor edits for at least 80% of the patients. Conclusions: Compared with manual contouring, autosegmentation using SPICE for the HN, thorax, liver, and male pelvis regions is efficient and shows significant promise for clinical utility

  20. Novel Model Predictive Control of a PM Synchronous Motor Drive; Design of the Innovative Structure, Feasibility and Stability Analysis, Efficient Implementation, Experimental Validation

    OpenAIRE

    Preindl, Matthias

    2014-01-01

    This text focuses on advanced torque control of permanent magnet synchronous motor drives. A novel modular structure is introduced to simplify the design and implementation of Model Predictive Control (MPC). The layout consists of the control and the control framework. The dynamic control is the novel virtual flux controller, which is used to reach desired reference values, and the state observer, which is used to reduce effects of non-modeled system properties. The control framework consists...

  1. Description of the Sandia Validation Metrics Project

    International Nuclear Information System (INIS)

    This report describes the underlying principles and goals of the Sandia ASCI Verification and Validation Program Validation Metrics Project. It also gives a technical description of two case studies, one in structural dynamics and the other in thermomechanics, that serve to focus the technical work of the project in Fiscal Year 2001

  2. A physical approach to protein structure prediction.

    OpenAIRE

    Crivelli, Silvia; Eskow, Elizabeth; Bader, Brett; Lamberti, Vincent; Byrd, Richard; Schnabel, Robert; Head-Gordon, Teresa

    2002-01-01

    We describe our global optimization method called Stochastic Perturbation with Soft Constraints (SPSC), which uses information from known proteins to predict secondary structure, but not in the tertiary structure predictions or in generating the terms of the physics-based energy function. Our approach is also characterized by the use of an all atom energy function that includes a novel hydrophobic solvation function derived from experiments that shows promising ability for energy discriminati...

  3. Validation of simulation models

    DEFF Research Database (Denmark)

    Rehman, Muniza; Pedersen, Stig Andur

    2012-01-01

    In philosophy of science, the interest for computational models and simulations has increased heavily during the past decades. Different positions regarding the validity of models have emerged but the views have not succeeded in capturing the diversity of validation methods. The wide variety of...... models has been somewhat narrow-minded reducing the notion of validation to establishment of truth. This article puts forward the diversity in applications of simulation models that demands a corresponding diversity in the notion of validation....

  4. The Concept of Validity

    Science.gov (United States)

    Borsboom, Denny; Mellenbergh, Gideon J.; van Heerden, Jaap

    2004-01-01

    This article advances a simple conception of test validity: A test is valid for measuring an attribute if (a) the attribute exists and (b) variations in the attribute causally produce variation in the measurement outcomes. This conception is shown to diverge from current validity theory in several respects. In particular, the emphasis in the…

  5. Validation of the k-filtering technique for a signal composed of random-phase plane waves and non-random coherent structures

    Directory of Open Access Journals (Sweden)

    O. W. Roberts

    2014-12-01

    Full Text Available Recent observations of astrophysical magnetic fields have shown the presence of fluctuations being wave-like (propagating in the plasma frame and those described as being structure-like (advected by the plasma bulk velocity. Typically with single-spacecraft missions it is impossible to differentiate between these two fluctuations, due to the inherent spatio-temporal ambiguity associated with a single point measurement. However missions such as Cluster which contain multiple spacecraft have allowed for temporal and spatial changes to be resolved, using techniques such as k filtering. While this technique does not assume Taylor's hypothesis it requires both weak stationarity of the time series and that the fluctuations can be described by a superposition of plane waves with random phases. In this paper we test whether the method can cope with a synthetic signal which is composed of a combination of non-random-phase coherent structures with a mean radius d and a mean separation λ, as well as plane waves with random phase.

  6. Are patients reliable when self-reporting medication use? Validation of structured drug interviews and home visits by drug analysis and prescription data in acutely hospitalized patients

    DEFF Research Database (Denmark)

    Glintborg, Bente; Hillestrøm, Peter René; Olsen, Lenette Holm;

    2007-01-01

    interview, but 14 of these drugs were registered in either hospital files or pharmacy records. Overall, the sensitivity of information from hospital files, structured interviews, and pharmacy records in identifying drug users was 87% to 93%, with no significant differences between methods. In conclusion......The medication history among hospitalized patients often relies on patients' self-reports due to insufficient communication between health care professionals. The aim of the present study was to estimate the reliability of patients' self-reported medication use. Five hundred patients admitted to an...... acute medical department at a Danish university hospital were interviewed on the day of admission about their recent medication use. Blood samples drawn immediately after admission were screened for contents of 5 drugs (digoxin, bendroflumethiazide, amlodipine, simvastatin, glimepiride), and the results...

  7. Are patients reliable when self-reporting medication use? Validation of structured drug interviews and home visits by drug analysis and prescription data in acutely hospitalized patients

    DEFF Research Database (Denmark)

    Glintborg, Bente; Hillestrøm, Peter René; Olsen, Lenette Holm;

    2007-01-01

    The medication history among hospitalized patients often relies on patients' self-reports due to insufficient communication between health care professionals. The aim of the present study was to estimate the reliability of patients' self-reported medication use. Five hundred patients admitted to an...... were compared to the patients' self-reported medication history. Information on prescribed drugs dispensed from any Danish pharmacy was collected from nationwide real-time pharmacy records. The authors performed home visits in a subgroup of 115 patients 4 weeks after their discharge. Stored drugs were...... inspected, and patients were interviewed about their drug use. Additional blood samples were drawn for drug analysis. The median age of included patients was 72 years, and 298 patients (60%) were women. Patients reported use of 3 (median) prescription-only medications (range, 0-14) during the structured...

  8. Principles of Proper Validation

    DEFF Research Database (Denmark)

    Esbensen, Kim; Geladi, Paul

    2010-01-01

    -validation) on all data sets. Within its own design and scope, cross-validation is in reality a sub-optimal simulation of test set validation, crippled by a critical sampling variance omission, as it manifestly is based on one data set only (training data set). Other re-sampling validation methods are shown to...... suffer from the same deficiencies. The PPV are universal and can be applied to all situations in which the assessment of performance is desired: prediction-, classification-, time series forecasting-, modeling validation. The key element of PPV is the Theory of Sampling (TOS), which allow insight into...

  9. High-resolution noise substitution to measure overfitting and validate resolution in 3D structure determination by single particle electron cryomicroscopy.

    Science.gov (United States)

    Chen, Shaoxia; McMullan, Greg; Faruqi, Abdul R; Murshudov, Garib N; Short, Judith M; Scheres, Sjors H W; Henderson, Richard

    2013-12-01

    Three-dimensional (3D) structure determination by single particle electron cryomicroscopy (cryoEM) involves the calculation of an initial 3D model, followed by extensive iterative improvement of the orientation determination of the individual particle images and the resulting 3D map. Because there is much more noise than signal at high resolution in the images, this creates the possibility of noise reinforcement in the 3D map, which can give a false impression of the resolution attained. The balance between signal and noise in the final map at its limiting resolution depends on the image processing procedure and is not easily predicted. There is a growing awareness in the cryoEM community of how to avoid such over-fitting and over-estimation of resolution. Equally, there has been a reluctance to use the two principal methods of avoidance because they give lower resolution estimates, which some people believe are too pessimistic. Here we describe a simple test that is compatible with any image processing protocol. The test allows measurement of the amount of signal and the amount of noise from overfitting that is present in the final 3D map. We have applied the method to two different sets of cryoEM images of the enzyme beta-galactosidase using several image processing packages. Our procedure involves substituting the Fourier components of the initial particle image stack beyond a chosen resolution by either the Fourier components from an adjacent area of background, or by simple randomisation of the phases of the particle structure factors. This substituted noise thus has the same spectral power distribution as the original data. Comparison of the Fourier Shell Correlation (FSC) plots from the 3D map obtained using the experimental data with that from the same data with high-resolution noise (HR-noise) substituted allows an unambiguous measurement of the amount of overfitting and an accompanying resolution assessment. A simple formula can be used to calculate an

  10. Coarse-grained/molecular mechanics of the TAS2R38 bitter taste receptor: experimentally-validated detailed structural prediction of agonist binding.

    Directory of Open Access Journals (Sweden)

    Alessandro Marchiori

    Full Text Available Bitter molecules in humans are detected by ∼25 G protein-coupled receptors (GPCRs. The lack of atomic resolution structure for any of them is complicating an in depth understanding of the molecular mechanisms underlying bitter taste perception. Here, we investigate the molecular determinants of the interaction of the TAS2R38 bitter taste receptor with its agonists phenylthiocarbamide (PTC and propylthiouracil (PROP. We use the recently developed hybrid Molecular Mechanics/Coarse Grained (MM/CG method tailored specifically for GPCRs. The method, through an extensive exploration of the conformational space in the binding pocket, allows the identification of several residues important for agonist binding that would have been very difficult to capture from the standard bioinformatics/docking approach. Our calculations suggest that both agonists bind to Asn103, Phe197, Phe264 and Trp201, whilst they do not interact with the so-called extra cellular loop 2, involved in cis-retinal binding in the GPCR rhodopsin. These predictions are consistent with data sets based on more than 20 site-directed mutagenesis and functional calcium imaging experiments of TAS2R38. The method could be readily used for other GPCRs for which experimental information is currently lacking.

  11. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars. Part 1. Model structure, simulation of bounded rationality, and model validation

    International Nuclear Information System (INIS)

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated. (author)

  12. Validación de un cuestionario de contexto para evaluar sistemas educativos con Modelos de Ecuaciones Estructurales. [Validation of a context questionnaire for the evaluation of educational systems with Structural Equations Modeling].

    Directory of Open Access Journals (Sweden)

    González-Montesinos, Manuel-Jorge

    2010-12-01

    Full Text Available This work shows the use of Structural Equations Modeling (SEM methodology to validate the conceptual structure of context questionnaires employed in national and international studies that evaluate the educational achievement of students. Unfortunately, evaluation agencies do not assign the same amount of technical resources to context questionnaires as those allotted to achievement tests, consequently the former are rarely subject to validity studies. In order to show the use of SEM methodology, a questionnaire was selected, which was employed by the National Institute for the Evaluation of Education to investigate the background factors associated with educational achievement of elementary school students in the third grade. It was administered to a national representative sample of 55,312 students. This questionnaire is analyzed according to SEM procedures of confirmatory factor analysis (CFA. The obtained results provide evidence for the constructive validity of this tool. Este trabajo tiene el propósito de mostrar el uso de la metodología de Modelos de Ecuaciones Estructurales (SEM para validar la estructura conceptual de cuestionarios de contexto que se utilizan en los estudios nacionales e internacionales para evaluar el logro educativo de los escolares. Desgraciadamente, los organismos evaluadores no destinan los mismos recursos técnicos a los cuestionarios de contexto que a las pruebas de aprendizaje, por lo que rara vez los primeros son sujetos a estudios de validez. Para mostrar el uso de la metodología SEM, se seleccionó el cuestionario dirigido a alumnos que utilizó el Instituto Nacional para la Evaluación de la Educación (INEE para conocer los factores de contexto asociados el logro educativo de los estudiantes de tercero de primaria, el que se aplicó a una muestra representativa nacional de 55, 312 alumnos. A dicho instrumento se le aplican los supuestos y procedimientos del análisis factorial confirmatorio (AFC y se

  13. Validating LiDAR Derived Estimates of Canopy Height, Structure and Fractional Cover in Riparian Areas: A Comparison of Leaf-on and Leaf-off LiDAR Data

    Science.gov (United States)

    Wasser, L. A.; Chasmer, L. E.; Taylor, A.; Day, R.

    2010-12-01

    Characterization of riparian buffers is integral to understanding the landscape scale impacts of disturbance on wildlife and aquatic ecosystems. Riparian buffers may be characterized using in situ plot sampling or via high resolution remote sensing. Field measurements are time-consuming and may not cover a broad range of ecosystem types. Further, spectral remote sensing methods introduce a compromise between spatial resolution (grain) and area extent. Airborne LiDAR can be used to continuously map and characterize riparian vegetation structure and composition due to the three-dimensional reflectance of laser pulses within and below the canopy, understory and at the ground surface. The distance between reflections (or ‘returns’) allows for detection of narrow buffer corridors at the landscape scale. There is a need to compare leaf-off and leaf-on surveyed LiDAR data with in situ measurements to assess accuracy in landscape scale analysis. These comparisons are particularly important considering increased availability of leaf-off surveyed LiDAR datasets. And given this increased availability, differences between leaf-on and leaf-off derived LiDAR metrics are largely unknown for riparian vegetation of varying composition and structure. This study compares the effectiveness of leaf-on and leaf-off LiDAR in characterizing riparian buffers of varying structure and composition as compared to field measurements. Field measurements were used to validate LiDAR derived metrics. Vegetation height, canopy cover, density and overstory and understory species composition were recorded in 80 random plots of varying vegetation type, density and structure within a Pennsylvania watershed (-77.841, 40.818). Plot data were compared with LiDAR data collected during leaf on and leaf off conditions to determine 1) accuracy of LiDAR derived metrics compared to field measures and 2) differences between leaf-on and leaf-off LiDAR metrics. Results illustrate that differences exist between

  14. Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

    DEFF Research Database (Denmark)

    Zhu, Mingyao; Bzdusek, Karl; Brink, Carsten; Eriksen, Jesper Grau; Hansen, Olfred; Jensen, Helle Anita; Gay, Hiram A; Thorstad, Wade; Widder, Joachim; Brouwer, Charlotte L; Steenbakkers, Roel J H M; Vanhauten, Hubertus A M; Cao, Jeffrey Q; McBrayne, Gail; Patel, Salil H; Cannon, Donald M; Hardcastle, Nicholas; Tomé, Wolfgang A; Guckenberg, Matthias; Parikh, Parag J

    2013-01-01

    Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE).......Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE)....

  15. Validity in qualitative research

    OpenAIRE

    Kuzmanić, Marja

    2015-01-01

    This paper addresses several issues related to validity in qualitative research and, more specifically, explores the ways in which validity has been discussed and applied in research with qualitative interviews. The central question is to what extent, if at all, traditional positivist validity criteria are applicable, but also relevant, for evaluation of research with qualitative interviewing. The qualitative interview has been chosen as the focal point of this paper because of its peculiarit...

  16. Combined Molecular Dynamics Simulations and Experimental Studies of the Structure and Dynamics of Poly-Amido-Saccharides.

    Science.gov (United States)

    Chin, Stacy L; Lu, Qing; Dane, Eric L; Dominguez, Laura; McKnight, Christopher J; Straub, John E; Grinstaff, Mark W

    2016-05-25

    Poly-amido-saccharides (PAS) are carbohydrate-based, enantiopure synthetic polymers in which sugar repeat units are joined by amide linkages. This unique and relatively rigid pyranose backbone contributes to their defined helical secondary structure and remarkable chemical properties. Glucose- (glc-) and galactose- (gal-) PAS 10-mer structures are synthesized and investigated with molecular dynamics (MD) simulations and experimental measurements. Quantum mechanical DFT energy minimization calculations, as well as experimental observables including circular dichroism, (1)H,(13)C-HSQC, and (1)H,(1)H-NOESY 2D-NMR studies, validated the all-atom simulation models produced using a modified CHARMM force field. Water radial distribution functions show distinct differences in the glc- and gal-PAS systems that correlate well with observed differences in solubility between gal-PASs and glc-PASs. The computational analysis and MD simulations are in good agreement with experimental results, validating the proposed models as reliable representations of novel glc- and gal-PASs. PMID:27119983

  17. Validation of HEDR models

    International Nuclear Information System (INIS)

    The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computer models for estimating the possible radiation doses that individuals may have received from past Hanford Site operations. This document describes the validation of these models. In the HEDR Project, the model validation exercise consisted of comparing computational model estimates with limited historical field measurements and experimental measurements that are independent of those used to develop the models. The results of any one test do not mean that a model is valid. Rather, the collection of tests together provide a level of confidence that the HEDR models are valid

  18. Validation of HEDR models

    International Nuclear Information System (INIS)

    The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computer models for estimating the possible radiation doses that individuals may have received from past Hanford Site operations. This document describes the validation of these models. In the HEDR Project, the model validation exercise consisted of comparing computational model predictions with limited historical field measurements and experimental measurements that are independent of those used to develop the models. The results of any one test do not mean that a model is valid. Rather, the collection of tests together provide a level of confidence that the HEDR models are valid

  19. Validation: the eluding definition

    International Nuclear Information System (INIS)

    The term 'validation' is featured prominently in the literature on radioactive high-level waste (HLW) disposal. There exists, however, no unique definition of 'validation' although it is generally understood to be related to model testing using experiments. This paper reviews the several definitions of 'validation' and proposes their categorization into three main classes. The first class links validation to the goal of predicting the physical world as faithfully as possible. This view has been criticized as being unattainable and, in any event, unsuitable for setting goals for the safety analyses. Other definitions (Class 2) are strictly operational, and associate validation only to situations where the models can be tested against observational data. In this view, the decision to retain a predictive model for use in safety assessments does not belong to the remit of 'validation'. The third class of definitions focuses, instead, 'validation' on the quality of the decision-making process, which shifts the debate from validation in the observational sense to 'reasonable assurance' and 'confidence building'. In this third view, one cannot determine when a model or a suite of models are actually 'validated'. The lack of consensus on the meaning of 'validation' is linked to its short history as a technical term. The first technical definition dates from the mid-fifties. The term was adopted thereafter in the computer field and elevated to its present status by the computer revolution of the seventies and early eighties. The term has made its appearance in some HLW safety standards only in the late eighties and it is virtually unmentioned in the low-level waste standards for disposal safety. The continued informal use of the term 'validation' in the field of HLW disposal can become cause for endless speculations. The paper proposes either abandoning the use of this term or agreeing to a common definition. (author) 36 refs

  20. Automatic molecular structure perception for the universal force field.

    Science.gov (United States)

    Artemova, Svetlana; Jaillet, Léonard; Redon, Stephane

    2016-05-15

    The Universal Force Field (UFF) is a classical force field applicable to almost all atom types of the periodic table. Such a flexibility makes this force field a potential good candidate for simulations involving a large spectrum of systems and, indeed, UFF has been applied to various families of molecules. Unfortunately, initializing UFF, that is, performing molecular structure perception to determine which parameters should be used to compute the UFF energy and forces, appears to be a difficult problem. Although many perception methods exist, they mostly focus on organic molecules, and are thus not well-adapted to the diversity of systems potentially considered with UFF. In this article, we propose an automatic perception method for initializing UFF that includes the identification of the system's connectivity, the assignment of bond orders as well as UFF atom types. This perception scheme is proposed as a self-contained UFF implementation integrated in a new module for the SAMSON software platform for computational nanoscience (http://www.samson-connect.net). We validate both the automatic perception method and the UFF implementation on a series of benchmarks. PMID:26927616

  1. STOCK: Structure mapper and online coarse-graining kit for molecular simulations

    International Nuclear Information System (INIS)

    We present a web toolkit STructure mapper and Online Coarse-graining Kit for setting up coarse-grained molecular simulations. The kit consists of two tools: structure mapping and Boltzmann inversion tools. The aim of the first tool is to define a molecular mapping from high, e.g. all-atom, to low, i.e. coarse-grained, resolution. Using a graphical user interface it generates input files, which are compatible with standard coarse-graining packages, e.g. VOTCA and DLCGMAP. Our second tool generates effective potentials for coarse-grained simulations preserving the structural properties, e.g. radial distribution functions, of the underlying higher resolution model. The required distribution functions can be provided by any simulation package. Simulations are performed on a local machine and only the distributions are uploaded to the server. The applicability of the toolkit is validated by mapping atomistic pentane and polyalanine molecules to a coarse-grained representation. Effective potentials are derived for systems of TIP3P (transferable intermolecular potential 3 point) water molecules and salt solution. The presented coarse-graining web toolkit is available at http://stock.cmm.ki.si

  2. SOSS ICN Model Validation

    Science.gov (United States)

    Zhu, Zhifan

    2016-01-01

    Under the NASA-KAIA-KARI ATM research collaboration agreement, SOSS ICN Model has been developed for Incheon International Airport. This presentation describes the model validation work in the project. The presentation will show the results and analysis of the validation.

  3. An SAT® Validity Primer

    Science.gov (United States)

    Shaw, Emily J.

    2015-01-01

    This primer should provide the reader with a deeper understanding of the concept of test validity and will present the recent available validity evidence on the relationship between SAT® scores and important college outcomes. In addition, the content examined on the SAT will be discussed as well as the fundamental attention paid to the fairness of…

  4. Checklists for external validity

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke; Vondeling, Hindrik

    2014-01-01

    RATIONALE, AIMS AND OBJECTIVES: The quality of the current literature on external validity varies considerably. An improved checklist with validated items on external validity would aid decision-makers in judging similarities among circumstances when transferring evidence from a study setting to an....... The retrieved checklist items were assessed for (i) the methodology used in primary literature, justifying inclusion of each item; and (ii) the number of times each item appeared in checklists. RESULTS: Fifteen papers were identified, presenting a total of 21 checklists for external validity, yielding...... a total of 38 checklist items. Empirical support was considered the most valid methodology for item inclusion. Assessment of methodological justification showed that none of the items were supported empirically. Other kinds of literature justified the inclusion of 22 of the items, and 17 items were...

  5. Adaptive Space Structures

    Science.gov (United States)

    Wada, B.

    1993-01-01

    The term adaptive structures refers to a structural control approach in which sensors, actuators, electronics, materials, structures, structural concepts, and system-performance-validation strategies are integrated to achieve specific objectives.

  6. On validation of multibody musculoskeletal models

    DEFF Research Database (Denmark)

    Lund, Morten Enemark; de Zee, Mark; Andersen, Michael Skipper; Rasmussen, John

    2012-01-01

    This paper reviews the opportunities to validate multibody musculoskeletal models in view of the current transition of musculoskeletal modelling from a research topic to a practical simulation tool in product design, healthcare and other important applications. This transition creates a new need...... practical steps for improvement of the validation of multibody musculoskeletal models are pointed out and directions for future research in the field are proposed. It is our hope that a more structured approach to model validation can help to improve the credibility of musculoskeletal models....

  7. "Faith Maturity Scale" for Chinese: A Revision and Construct Validation

    OpenAIRE

    Hui, CH; Ying Lau, EY; Wai Ng, EC; Ying Mok, DS; Cheung, SF

    2011-01-01

    Using a large sample of Chinese Christians (n = 2,196), we examined the internal structure, reliability, and validity of the Faith Maturity Scale (FMS). Despite its being developed in North America, and for a mainline Protestant population, the FMS was shown to have validity among non-Western, non-mainline Protestants. There is convergent validity with self-reported religious practices and a belief measure of religiosity. Our analyses also confirmed good construct validity with the Big Five p...

  8. Validating and Investigating Reliability of Comprehensive Feeding Practices Questionnaire

    OpenAIRE

    Saeid Doaei; Naser Kalantari; Maryam Gholamalizadeh; Bahram Rashidkhani

    2013-01-01

    Background: The present research aims to validate and discuss the reliability of Comprehensive Feeding Practices Questionnaire (CFPQ). Materials and Methods: In this cross-sectional study, 150 mothers with 3-6 year old children in the city of Rasht were selected through cluster random sampling from the public and private kindergartens in 2010. After being confident about the translation validity, the degree of validation (content and structure) and validity (test-retest reliability and intern...

  9. Model Validation Status Review

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2001-11-28

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M&O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  10. Model Validation Status Review

    International Nuclear Information System (INIS)

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M and O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  11. Validación estructural del Wong-Law Emotional Intelligence Scale (WLEIS: estudio preliminar en adultos / Structural validation of the Wong-Law Emotional Intelligence Scale (WLEIS: preliminary study in adults

    Directory of Open Access Journals (Sweden)

    César Merino Soto

    2016-06-01

    structure validity of the WLEIS in Peruvian adults. There were 120 participants (72 women between 17 and 59 years old who responded to the questionnaire mediated by the internet. The internal structure was analyzed using structural equations methodology. A satisfactory structure of 4 factors and high factorial loads of items was found. The inter-factorial correlations were high or moderately high – and the internal consistency was good. It is concluded that the first results are acceptable – to assume that the Wong-Law model is also apparently generalizable.

  12. Instrumentation and radiopharmaceutical validation

    International Nuclear Information System (INIS)

    Although the promise of new positron emission tomography (PET) imaging agents is great, the process of bringing these agents to commercialization remains in its infancy. There are no PET products today that have gone through the full clinical and chemistry development process required to gain marketing approval by the US Food and Drug Administration (Fda). The purpose of this paper was to review validation from the perspective of the chemistry, manufacturing and controls (CMC) section of an Fda filing, as well as the validation requirements described in Fda good manufacturing practice (GMP) regulations, guidance documents and general chapters of the US Pharmacopoeia (Usp). The review includes discussion of validation from development to commercial production of PET radiopharmaceuticals with a special emphasis on equipment and instrumentation used in production and testing. The goal is to stimulate a dialog that leads to the standardization of industry practices and regulatory requirements for validation practices in PET.

  13. Model Validation Using Coordinate Distance with Performance Sensitivity

    Directory of Open Access Journals (Sweden)

    Jiann-Shiun Lew

    2008-01-01

    Full Text Available This paper presents an innovative approach to model validation for a structure with significant parameter variations. Model uncertainty of the structural dynamics is quantified with the use of a singular value decomposition technique to extract the principal components of parameter change, and an interval model is generated to represent the system with parameter uncertainty. The coordinate vector, corresponding to the identified principal directions, of the validation system is computed. The coordinate distance between the validation system and the identified interval model is used as a metric for model validation. A beam structure with an attached subsystem, which has significant parameter uncertainty, is used to demonstrate the proposed approach.

  14. Cross validation in LULOO

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Hansen, Lars Kai; Larsen, Jan

    1996-01-01

    The leave-one-out cross-validation scheme for generalization assessment of neural network models is computationally expensive due to replicated training sessions. Linear unlearning of examples has recently been suggested as an approach to approximative cross-validation. Here we briefly review the...... linear unlearning scheme, dubbed LULOO, and we illustrate it on a systemidentification example. Further, we address the possibility of extracting confidence information (error bars) from the LULOO ensemble....

  15. Verification and validation benchmarks.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-02-01

    Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of

  16. HEDR model validation plan

    International Nuclear Information System (INIS)

    The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computational ''tools'' for estimating the possible radiation dose that individuals may have received from past Hanford Site operations. This document describes the planned activities to ''validate'' these tools. In the sense of the HEDR Project, ''validation'' is a process carried out by comparing computational model predictions with field observations and experimental measurements that are independent of those used to develop the model

  17. Introduction to Validity

    Institute of Scientific and Technical Information of China (English)

    张楠

    2015-01-01

    The designing of a test paper strictly follows the specification of the relevant Testing Syllabus, which covers various skills and abilities needed for real communicative situation. A test with high content validity is likely to have a positive impact upon the teaching. Therefore, a test with a high content validity will undoubtedly promote the college English education and it will certainly facilitate the implementation of the Syllabus.

  18. Validating year 2000 compliance

    OpenAIRE

    Deursen, van, A; Klint, Paul; Sellink, M.P.A.

    1997-01-01

    Validating year 2000 compliance involves the assessment of the correctness and quality of a year 2000 conversion. This entails inspecting both the quality of the conversion emph{process followed, and of the emph{result obtained, i.e., the converted system. This document provides an overview of the techniques that can be used to validate year 2000 compliance. It includes typical code fragments, and a discussion of existing technology, impact analysis, solution strategies, code correction, test...

  19. Validation suite for MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Mosteller, R. D. (Russell D.)

    2002-01-01

    Two validation suites, one for criticality and another for radiation shielding, have been defined and tested for the MCNP Monte Carlo code. All of the cases in the validation suites are based on experiments so that calculated and measured results can be compared in a meaningful way. The cases in the validation suites are described, and results from those cases are discussed. For several years, the distribution package for the MCNP Monte Carlo code1 has included an installation test suite to verify that MCNP has been installed correctly. However, the cases in that suite have been constructed primarily to test options within the code and to execute quickly. Consequently, they do not produce well-converged answers, and many of them are physically unrealistic. To remedy these deficiencies, sets of validation suites are being defined and tested for specific types of applications. All of the cases in the validation suites are based on benchmark experiments. Consequently, the results from the measurements are reliable and quantifiable, and calculated results can be compared with them in a meaningful way. Currently, validation suites exist for criticality and radiation-shielding applications.

  20. A fingerprint based metric for measuring similarities of crystalline structures

    OpenAIRE

    Zhu, Li; Amsler, Maximilian; Fuhrer, Tobias; Schaefer, Bastian; Faraji, Somayeh; Rostami, Samare; Ghasemi, S. Alireza; Sadeghi, Ali; Grauzinyte, Migle; Wolverton, Christopher; Goedecker, Stefan

    2015-01-01

    Measuring similarities/dissimilarities between atomic structures is important for the exploration of potential energy landscapes. However, the cell vectors together with the coordinates of the atoms, which are generally used to describe periodic systems, are quantities not suitable as fingerprints to distinguish structures. Based on a characterization of the local environment of all atoms in a cell we introduce crystal fingerprints that can be calculated easily and allow to define configurati...

  1. Predicting RNA 3D structure using a coarse-grain helix-centered model

    OpenAIRE

    Kerpedjiev, Peter; Höner zu Siederdissen, Christian; Hofacker, Ivo L

    2015-01-01

    A 3D model of RNA structure can provide information about its function and regulation that is not possible with just the sequence or secondary structure. Current models suffer from low accuracy and long running times and either neglect or presume knowledge of the long-range interactions which stabilize the tertiary structure. Our coarse-grained, helix-based, tertiary structure model operates with only a few degrees of freedom compared with all-atom models while preserving the ability to sampl...

  2. An Estimation Method of a Constitutive-law for the Rod Model of DNA using Discrete-Structure Simulations

    CERN Document Server

    Hinkle, Adam R; Palanthandalam-Madapusi, Harish J

    2009-01-01

    The continuum-rod model has emerged as an efficient tool to describe the long-length-scale structural-deformations of DNA which are critical to understanding the nature of many biological processes such as gene expression. However, a significant challenge in continuum-mechanics-based modeling of DNA is to estimate its constitutive law, which follows from its interatomic bond-stiffness. Experiments and all-atom molecular dynamics (MD) simulations have suggested that the constitutive law is nonlinear and non-homogeneous (sequence-dependent) along the length of DNA. In this paper, we present an estimation method and a validation study using discrete-structure simulations. We consider a simple cantilever-rod with an artificially constructed, discrete lattice-structure which gives rise to a constitutive law. Large deformations are then simulated. An effective constitutive-law is estimated from these deformations using inverse methods. Finally, we test the estimated law by employing it in the continuum rod-model an...

  3. Containment Code Validation Matrix

    International Nuclear Information System (INIS)

    The Committee on the Safety of Nuclear Installations (CSNI) formed the CCVM (Containment Code Validation Matrix) task group in 2002. The objective of this group was to define a basic set of available experiments for code validation, covering the range of containment (ex-vessel) phenomena expected in the course of light and heavy water reactor design basis accidents and beyond design basis accidents/severe accidents. It was to consider phenomena relevant to pressurised heavy water reactor (PHWR), pressurised water reactor (PWR) and boiling water reactor (BWR) designs of Western origin as well as of Eastern European VVER types. This work would complement the two existing CSNI validation matrices for thermal hydraulic code validation (NEA/CSNI/R(1993)14) and In-vessel core degradation (NEA/CSNI/R(2001)21). The report initially provides a brief overview of the main features of a PWR, BWR, CANDU and VVER reactors. It also provides an overview of the ex-vessel corium retention (core catcher). It then provides a general overview of the accident progression for light water and heavy water reactors. The main focus is to capture most of the phenomena and safety systems employed in these reactor types and to highlight the differences. This CCVM contains a description of 127 phenomena, broken down into 6 categories: - Containment Thermal-hydraulics Phenomena; - Hydrogen Behaviour (Combustion, Mitigation and Generation) Phenomena; - Aerosol and Fission Product Behaviour Phenomena; - Iodine Chemistry Phenomena; - Core Melt Distribution and Behaviour in Containment Phenomena; - Systems Phenomena. A synopsis is provided for each phenomenon, including a description, references for further information, significance for DBA and SA/BDBA and a list of experiments that may be used for code validation. The report identified 213 experiments, broken down into the same six categories (as done for the phenomena). An experiment synopsis is provided for each test. Along with a test description

  4. Validation of analytical methods

    Directory of Open Access Journals (Sweden)

    Xavier Rius, F.

    2002-03-01

    Full Text Available In this paper we shall discuss the concept of method validation, describe the various elements and explain its close relationship with fitness for purpose. Method validation is based on the assumption that a series of requirements are fulfilled and we shall explain how these requirements are selected, the way in which evidence is supplied and what work has to be carried out in the laboratory. The basic principles of method validation and the different ways to validate a methodology, by inter-laboratory comparison or performing an in-house validation, are also described.En este artículo se discute el concepto de validación del método, se describen los elementos que la componen y se explica la fuerte relación entre la validación y las características de ajuste. El método de validación se basa en el cumplimiento de una serie de requerimientos, se explica como seleccionar esos requerimientos, la forma en que se suministran evidencias, y que trabajo se debe llevar a cabo en el laboratorio. También se describen, los principios básicos del método de validación y los diferentes caminos para validar una metodología, tanto en la comparación entre laboratorios o como cuando se lleva a cabo una validación dentro del laboratorio.

  5. Validation of Serious Games

    Directory of Open Access Journals (Sweden)

    Katinka van der Kooij

    2015-09-01

    Full Text Available The application of games for behavioral change has seen a surge in popularity but evidence on the efficacy of these games is contradictory. Anecdotal findings seem to confirm their motivational value whereas most quantitative findings from randomized controlled trials (RCT are negative or difficult to interpret. One cause for the contradictory evidence could be that the standard RCT validation methods are not sensitive to serious games’ effects. To be able to adapt validation methods to the properties of serious games we need a framework that can connect properties of serious game design to the factors that influence the quality of quantitative research outcomes. The Persuasive Game Design model [1] is particularly suitable for this aim as it encompasses the full circle from game design to behavioral change effects on the user. We therefore use this model to connect game design features, such as the gamification method and the intended transfer effect, to factors that determine the conclusion validity of an RCT. In this paper we will apply this model to develop guidelines for setting up validation methods for serious games. This way, we offer game designers and researchers handles on how to develop tailor-made validation methods.

  6. Rapid Robot Design Validation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Energid Technologies will create a comprehensive software infrastructure for rapid validation of robotic designs. The software will support push-button validation...

  7. Rapid Robot Design Validation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Energid Technologies will create a comprehensive software infrastructure for rapid validation of robot designs. The software will support push-button validation...

  8. Validating Animal Models

    Directory of Open Access Journals (Sweden)

    Nina Atanasova

    2015-06-01

    Full Text Available In this paper, I respond to the challenge raised against contemporary experimental neurobiology according to which the field is in a state of crisis because of the multiple experimental protocols employed in different laboratories and strengthening their reliability that presumably preclude the validity of neurobiological knowledge. I provide an alternative account of experimentation in neurobiology which makes sense of its experimental practices. I argue that maintaining a multiplicity of experimental protocols and strengthening their reliability are well justified and they foster rather than preclude the validity of neurobiological knowledge. Thus, their presence indicates thriving rather than crisis of experimental neurobiology.

  9. Sensitivity analysis and validation

    International Nuclear Information System (INIS)

    In the field of performance assessment modelling for high-level radioactive waste disposal in geologic repositories, evaluating model uncertainties is a key factor in estimating radionuclide transport rate and extrapolating thousands of years into the future. Sensitivity and uncertainty analysis is performed to determine the relationships among the input and output variables of a mathematical model through numerical methods. Because post-closure performance assessment relies heavily on models, sensitivity and uncertainty analyses will become an integral part of the model evaluation and validation process. Model validation is also needed to establish the credibility of predictions to the technical community, and to achieve grater public confidence in the long-term safety of a geologic repository. In this paper, the role of sensitivity analysis as a part of near-field performance assessment will be discussed in terms of model validation. A description of the ENTRY (the Engineered Scale Test and Research Facility) project for validation study will also be presented. (au) (17 refs., 5 figs.)

  10. Validation and test report

    DEFF Research Database (Denmark)

    Pedersen, Jens Meldgaard; Andersen, T. Bull

    2012-01-01

    . As a consequence of extensive movement artefacts seen during dynamic contractions, the following validation and test report consists of a report that investigates the physiological responses to a static contraction in a standing and a supine position. Eight subjects performed static contractions of the ankle...

  11. A valid licence

    NARCIS (Netherlands)

    Spoolder, H.A.M.; Ingenbleek, P.T.M.

    2010-01-01

    A valid licence Tuesday, April 20, 2010 Dr Hans Spoolder and Dr Paul Ingenbleek, of Wageningen University and Research Centres, share their thoughts on improving farm animal welfare in Europe At the presentation of the European Strategy 2020 on 3rd March, President Barroso emphasised the need for Eu

  12. The dialogic validation

    DEFF Research Database (Denmark)

    Musaeus, Peter

    This paper is inspired by dialogism and the title is a paraphrase on Bakhtin's (1981) "The Dialogic Imagination". The paper investigates how dialogism can inform the process of validating inquiry-based qualitative research. The paper stems from a case study on the role of recognition in...

  13. The Chimera of Validity

    Science.gov (United States)

    Baker, Eva L.

    2013-01-01

    Background/Context: Education policy over the past 40 years has focused on the importance of accountability in school improvement. Although much of the scholarly discourse around testing and assessment is technical and statistical, understanding of validity by a non-specialist audience is essential as long as test results drive our educational…

  14. Validation of the organizational culture assessment instrument.

    Directory of Open Access Journals (Sweden)

    Brody Heritage

    Full Text Available Organizational culture is a commonly studied area in industrial/organizational psychology due to its important role in workplace behaviour, cognitions, and outcomes. Jung et al.'s [1] review of the psychometric properties of organizational culture measurement instruments noted many instruments have limited validation data despite frequent use in both theoretical and applied situations. The Organizational Culture Assessment Instrument (OCAI has had conflicting data regarding its psychometric properties, particularly regarding its factor structure. Our study examined the factor structure and criterion validity of the OCAI using robust analysis methods on data gathered from 328 (females = 226, males = 102 Australian employees. Confirmatory factor analysis supported a four factor structure of the OCAI for both ideal and current organizational culture perspectives. Current organizational culture data demonstrated expected reciprocally-opposed relationships between three of the four OCAI factors and the outcome variable of job satisfaction but ideal culture data did not, thus indicating possible weak criterion validity when the OCAI is used to assess ideal culture. Based on the mixed evidence regarding the measure's properties, further examination of the factor structure and broad validity of the measure is encouraged.

  15. Validation of the organizational culture assessment instrument.

    Science.gov (United States)

    Heritage, Brody; Pollock, Clare; Roberts, Lynne

    2014-01-01

    Organizational culture is a commonly studied area in industrial/organizational psychology due to its important role in workplace behaviour, cognitions, and outcomes. Jung et al.'s [1] review of the psychometric properties of organizational culture measurement instruments noted many instruments have limited validation data despite frequent use in both theoretical and applied situations. The Organizational Culture Assessment Instrument (OCAI) has had conflicting data regarding its psychometric properties, particularly regarding its factor structure. Our study examined the factor structure and criterion validity of the OCAI using robust analysis methods on data gathered from 328 (females = 226, males = 102) Australian employees. Confirmatory factor analysis supported a four factor structure of the OCAI for both ideal and current organizational culture perspectives. Current organizational culture data demonstrated expected reciprocally-opposed relationships between three of the four OCAI factors and the outcome variable of job satisfaction but ideal culture data did not, thus indicating possible weak criterion validity when the OCAI is used to assess ideal culture. Based on the mixed evidence regarding the measure's properties, further examination of the factor structure and broad validity of the measure is encouraged. PMID:24667839

  16. Validation of the Drinking Motives Questionnaire

    DEFF Research Database (Denmark)

    Fernandes-Jesus, Maria; Beccaria, Franca; Demant, Jakob Johan;

    2016-01-01

    • This paper assesses the validity of the DMQ-R (Cooper, 1994) among university students in six different European countries. • Results provide support for similar DMQ-R factor structures across countries. • Drinking motives have similar meanings among European university students....

  17. A logic generator and validator

    International Nuclear Information System (INIS)

    The on-line monitoring of a power plant (or any process plant) has three primary functions: data acquisition, data analysis, and data presentation. Relative to the second of these functions, advanced methods for generating reliable data analysis computer codes are presented. The results are illustrated for a safety parameter display system that provides operators with a computer-graphic summary of a nuclear power plant's safety status. In the conventional method of analysis code production, the systems analyst or designer generates rules by which the plant status is being evaluated, while the transcription of those rules to a computer code is done separately by a programmer. Subsequently, the analysis code produced by the programmer must be validated against the specifications prepared by the systems analyst. A logic generator and logic validator are presented to streamline these processes. The logic generator acquires the relevant specifications through a systematic dialogue with the designer and then translates them automatically into an efficient computer logic code, thus solvin the problem of a designer who is not a programmer interfacing with a programmer who is not a designer. The logic generator enhances code reliability in two ways. First, it encourages the systems analyst to produce more reliable and relevant specifications because of the logical structured order in which the interactive session is being conducted. Second, because of the mass production mode b which the logic codes are being generated, proving once the correctness of the code production process ensures the accuracy of all codes to be generated in the future. In the postproduction stage, a logic validator enhances code reliability by displaying a structura overview of the data analysis code, allowing the user an additional opportunity for code evaluation

  18. Development and validation of a prokaryotically expressed foot-and-mouth disease virus non-structural protein 2C'3AB-based immunochromatographic strip to differentiate between infected and vaccinated animals

    Directory of Open Access Journals (Sweden)

    Liu Xiang-Tao

    2011-04-01

    Full Text Available Abstract Background Foot-and-mouth disease (FMD is an extremely contagious viral disease of cattle, pigs, sheep, goats, and many cloven-hoofed wild animals. FMDV serotypes O and Asia 1 have circulated separately in China during the last fifty years, and eliminating infected animals and vaccination are the main policies to prevent and control FMD. Antibodies to NSPs exist in infected animals, and were utilized to differentiate between infected and vaccinated animals. The reliability of detection of 3AB or 3ABC antibodies is higher than that of other NSPs. The test of 3AB is still credible because 3C protein's immunogenicity is the weakest. The 2C protein, immediately N-terminal of 3AB, was used to differentiate between infected and vaccinated animals. The use of the immunochromatographic strip is facile for clinical laboratories lacking specialized equipment and for rapid field diagnosis. Results In this study, an immunochromatographic strip with non-structural protein (NSP 2C'3AB was developed and validated to differentiate foot-and-mouth disease infected from vaccinated animals. A part of N-terminal of 2C protein gene and whole 3AB gene were connected and prokaryotically expressed as the antigens labeled with colloidal gold was used as the detector, the 2C'3AB protein and rabbits anti-2C'3AB antibodies were blotted on the nitrocellulose(NC membrane for the test and control lines, respectively. 387 serum samples were collected to evaluate the characteristics of the strip in comparison with existing commercial 3ABC antibody ELISA kit. The coincidence rate of pigs negative serum, pigs vaccinated serum, pigs infected serum was 100%, 97.2%, 95.0%, respectively. The coincidence rate of cattle negative serum, cattle vaccinated serum, cattle infected serum was 100%, 96.7%, 98.0%, respectively. The coincidence rate of sheep negative serum, sheep infected serum was 97.6%, 96.3%, respectively. The strip was shown to be of high specificity and sensitivity

  19. Efficient Sampling in Fragment-Based Protein Structure Prediction Using an Estimation of Distribution Algorithm

    OpenAIRE

    Simoncini, David; Zhang, Kam Y. J.

    2013-01-01

    Fragment assembly is a powerful method of protein structure prediction that builds protein models from a pool of candidate fragments taken from known structures. Stochastic sampling is subsequently used to refine the models. The structures are first represented as coarse-grained models and then as all-atom models for computational efficiency. Many models have to be generated independently due to the stochastic nature of the sampling methods used to search for the global minimum in a complex e...

  20. Teseo code validation

    International Nuclear Information System (INIS)

    In this report some validation tests for the TESEO code are described. The TESEO code was developed at ENEA - Clementel Center in the framework of the C2RV code sequence. This code sequence produces multigroup resonance cross sections for fast reactor analysis. It consists of the codes TESEO, MC2-II, GERES, ANISN, MEDIL. The TESEO code processes basic nuclear data in ENDF-B format and produces an ultrafine group (2082 groups) cross section library for the MC2-II code. To validate the TESEO algorithms, the data produced by TESEO code were compared with the data produced by other well-tested codes which use different algorithms. No substantial differences was found between these data and the data produced by TESEO code. TESEO algorithms showed high reliability. A detailed study of TESEO calculation options was carried out. Their use and functions are shown to inform the user of the code

  1. CIPS Validation Data Plan

    Energy Technology Data Exchange (ETDEWEB)

    Nam Dinh

    2012-03-01

    This report documents analysis, findings and recommendations resulted from a task 'CIPS Validation Data Plan (VDP)' formulated as an POR4 activity in the CASL VUQ Focus Area (FA), to develop a Validation Data Plan (VDP) for Crud-Induced Power Shift (CIPS) challenge problem, and provide guidance for the CIPS VDP implementation. The main reason and motivation for this task to be carried at this time in the VUQ FA is to bring together (i) knowledge of modern view and capability in VUQ, (ii) knowledge of physical processes that govern the CIPS, and (iii) knowledge of codes, models, and data available, used, potentially accessible, and/or being developed in CASL for CIPS prediction, to devise a practical VDP that effectively supports the CASL's mission in CIPS applications.

  2. Software Validation in ATLAS

    International Nuclear Information System (INIS)

    The ATLAS collaboration operates an extensive set of protocols to validate the quality of the offline software in a timely manner. This is essential in order to process the large amounts of data being collected by the ATLAS detector in 2011 without complications on the offline software side. We will discuss a number of different strategies used to validate the ATLAS offline software; running the ATLAS framework software, Athena, in a variety of configurations daily on each nightly build via the ATLAS Nightly System (ATN) and Run Time Tester (RTT) systems; the monitoring of these tests and checking the compilation of the software via distributed teams of rotating shifters; monitoring of and follow up on bug reports by the shifter teams and periodic software cleaning weeks to improve the quality of the offline software further.

  3. Validating Animal Models

    OpenAIRE

    Nina Atanasova

    2015-01-01

    In this paper, I respond to the challenge raised against contemporary experimental neurobiology according to which the field is in a state of crisis because of the multiple experimental protocols employed in different laboratories and strengthening their reliability that presumably preclude the validity of neurobiological knowledge. I provide an alternative account of experimentation in neurobiology which makes sense of its experimental practices. I argue that maintaining a multiplicity of ex...

  4. NMR structure improvement: A structural bioinformatics & visualization approach

    Science.gov (United States)

    Block, Jeremy N.

    The overall goal of this project is to enhance the physical accuracy of individual models in macromolecular NMR (Nuclear Magnetic Resonance) structures and the realism of variation within NMR ensembles of models, while improving agreement with the experimental data. A secondary overall goal is to combine synergistically the best aspects of NMR and crystallographic methodologies to better illuminate the underlying joint molecular reality. This is accomplished by using the powerful method of all-atom contact analysis (describing detailed sterics between atoms, including hydrogens); new graphical representations and interactive tools in 3D and virtual reality; and structural bioinformatics approaches to the expanded and enhanced data now available. The resulting better descriptions of macromolecular structure and its dynamic variation enhances the effectiveness of the many biomedical applications that depend on detailed molecular structure, such as mutational analysis, homology modeling, molecular simulations, protein design, and drug design.

  5. Seismic Data Gathering and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Three recent earthquakes in the last seven years have exceeded their design basis earthquake values (so it is implied that damage to SSC’s should have occurred). These seismic events were recorded at North Anna (August 2011, detailed information provided in [Virginia Electric and Power Company Memo]), Fukushima Daichii and Daini (March 2011 [TEPCO 1]), and Kaswazaki-Kariwa (2007, [TEPCO 2]). However, seismic walk downs at some of these plants indicate that very little damage occurred to safety class systems and components due to the seismic motion. This report presents seismic data gathered for two of the three events mentioned above and recommends a path for using that data for two purposes. One purpose is to determine what margins exist in current industry standard seismic soil-structure interaction (SSI) tools. The second purpose is the use the data to validated seismic site response tools and SSI tools. The gathered data represents free field soil and in-structure acceleration time histories data. Gathered data also includes elastic and dynamic soil properties and structural drawings. Gathering data and comparing with existing models has potential to identify areas of uncertainty that should be removed from current seismic analysis and SPRA approaches. Removing uncertainty (to the extent possible) from SPRA’s will allow NPP owners to make decisions on where to reduce risk. Once a realistic understanding of seismic response is established for a nuclear power plant (NPP) then decisions on needed protective measures, such as SI, can be made.

  6. Characterization of the residual structure in the unfolded state of the Delta 131 Delta fragment of staphylococcal nuclease

    DEFF Research Database (Denmark)

    Francis, C. J.; Lindorff-Larsen, Kresten; Best, R. B.;

    2006-01-01

    The determination of the conformational preferences in unfolded states of proteins constitutes an important challenge in structural biology. We use inter-residue distances estimated from site-directed spin-labeling NMR experimental measurements as ensemble-averaged restraints in all-atom molecula...

  7. Fuzzy Petri Nets for Human Behavior Verification and Validation

    OpenAIRE

    M. Kouzehgar,; Badamchizadeh, M. A.; S.Khanmohammadi

    2011-01-01

    Regarding the rapid growth of the size and complexity of simulation applications, designing applicable and affordable verification and validation (V&V) structures is an important problem. On the other hand, nowadays human behavior models are principles to make decision in many simulations and in order to have valid decisions based on a reliable human decision model, first the model must pass the validation and verification criteria. Usually human behavior models are represented as fuzzy rule ...

  8. The Structure of a Melittin-Stabilized Pore

    OpenAIRE

    Leveritt, John M.; Pino-Angeles, Almudena; Lazaridis, Themis

    2015-01-01

    Melittin has been reported to form toroidal pores under certain conditions, but the atomic-resolution structure of these pores is unknown. A 9-μs all-atom molecular-dynamics simulation starting from a closely packed transmembrane melittin tetramer in DMPC shows formation of a toroidal pore after 1 μs. The pore remains stable with a roughly constant radius for the rest of the simulation. Surprisingly, one or two melittin monomers frequently transition between transmembrane and surface states. ...

  9. Adapforms: A framework for creating and validating adaptive forms

    DEFF Research Database (Denmark)

    Bohøj, Morten; Bouvin, Niels Olof; Gammelmark, Henrik

    2011-01-01

    AdapForms is a framework for adaptive forms, consisting of a form de nition language designating structure and constraints upon acceptable input, and a software architecture that continuously validates and adapts the form presented to the user. The validation is performed server-side, which enables...

  10. Measuring Long-Distance Romantic Relationships: A Validity Study

    Science.gov (United States)

    Pistole, M. Carole; Roberts, Amber

    2011-01-01

    This study investigated aspects of construct validity for the scores of a new long-distance romantic relationship measure. A single-factor structure of the long-distance romantic relationship index emerged, with convergent and discriminant evidence of external validity, high internal consistency reliability, and applied utility of the scores.…

  11. Validation of the Chinese Expanded Euthanasia Attitude Scale

    Science.gov (United States)

    Chong, Alice Ming-Lin; Fok, Shiu-Yeu

    2013-01-01

    This article reports the validation of the Chinese version of an expanded 31-item Euthanasia Attitude Scale. A 4-stage validation process included a pilot survey of 119 college students and a randomized household survey with 618 adults in Hong Kong. Confirmatory factor analysis confirmed a 4-factor structure of the scale, which can therefore be…

  12. Semantic Identification: Balancing between Complexity and Validity

    Directory of Open Access Journals (Sweden)

    Falelakis M

    2006-01-01

    Full Text Available An efficient scheme for identifying semantic entities within data sets such as multimedia documents, scenes, signals, and so forth, is proposed in this work. Expression of semantic entities in terms of syntactic properties is modelled with appropriately defined finite automata, which also model the identification procedure. Based on the structure and properties of these automata, formal definitions of attained validity and certainty and also required complexity are defined as metrics of identification efficiency. The main contribution of the paper relies on organizing the identification and search procedure in a way that maximizes its validity for bounded complexity budgets and reversely minimizes computational complexity for a given required validity threshold. The associated optimization problem is solved by using dynamic programming. Finally, a set of experiments provides insight to the introduced theoretical framework.

  13. Validation of seismic probabilistic risk analysis (PRA) methods

    International Nuclear Information System (INIS)

    The objective of validation research is to obtain information that can be used by the NRC to develop acceptance criteria for seismic probabilistic risk assessment (PRA's) and thus improve the regulatory process. The needs for validation and experimental data in seismic PRA methodologies are assessed to be in the following areas: 1) definition of seismic hazards; 2) capacity and failure data for equipment, piping, and structures; and 3) response analyses of nuclear power plant systems. The effort under discussion focuses its attention on the validation of methods and data which are used to determine plant response and fragility. Failure data for equipment are best addressed in separate effects laboratory testing; piping fragility requires both system and component testing; failure data for structures is difficult to obtain because it is not practical to test as-built structures. Validation of response analyses requires extensive comparisons with experimental data from complex site-structure-component systems

  14. Sensitivity validation technique for sequential kriging metamodel

    International Nuclear Information System (INIS)

    Metamodels have been developed with a variety of design optimization techniques in the field of structural engineering over the last decade because they are efficient, show excellent prediction performance, and provide easy interconnections into design frameworks. To construct a metamodel, a sequential procedure involving steps such as the design of experiments, metamodeling techniques, and validation techniques is performed. Because validation techniques can measure the accuracy of the metamodel, the number of presampled points for an accurate kriging metamodel is decided by the validation technique in the sequential kriging metamodel. Because the interpolation model such as the kriging metamodel based on computer experiments passes through responses at presampled points, additional analyses or reconstructions of the meta models are required to measure the accuracy of the meta model if existing validation techniques are applied. In this study, we suggest a sensitivity validation that does not require additional analyses or reconstructions of the meta models. Fourteen two dimensional mathematical problems and an engineering problem are illustrated to show the feasibility of the suggested method

  15. Model Validation in Ontology Based Transformations

    Directory of Open Access Journals (Sweden)

    Jesús M. Almendros-Jiménez

    2012-10-01

    Full Text Available Model Driven Engineering (MDE is an emerging approach of software engineering. MDE emphasizes the construction of models from which the implementation should be derived by applying model transformations. The Ontology Definition Meta-model (ODM has been proposed as a profile for UML models of the Web Ontology Language (OWL. In this context, transformations of UML models can be mapped into ODM/OWL transformations. On the other hand, model validation is a crucial task in model transformation. Meta-modeling permits to give a syntactic structure to source and target models. However, semantic requirements have to be imposed on source and target models. A given transformation will be sound when source and target models fulfill the syntactic and semantic requirements. In this paper, we present an approach for model validation in ODM based transformations. Adopting a logic programming based transformational approach we will show how it is possible to transform and validate models. Properties to be validated range from structural and semantic requirements of models (pre and post conditions to properties of the transformation (invariants. The approach has been applied to a well-known example of model transformation: the Entity-Relationship (ER to Relational Model (RM transformation.

  16. Validation and Variability

    DEFF Research Database (Denmark)

    Carusi, Annamaria

    2014-01-01

    and experimentally inclined modellers on one hand, and attempts to forge new collaborations with medical scientists on the other. Apart from the scientific interest of the population of models approach for tackling variability, the trial also offers a good illustration of the epistemology of experiment......Systems biology is currently making a bid to show that it is able to make an important contribution to personalised or precision medicine. In order to do so, systems biologists need to find a way of tackling the pervasive variability of biological systems that is manifested in the medical domain...... as inter-subject variability. This need is simultaneously social and epistemic: social as systems biologists attempt to engage with the interests and concerns of clinicians and others in applied medical research; epistemic as they attempt to develop new strategies to cope with variability in the validation...

  17. Validation of EMP bounds

    Energy Technology Data Exchange (ETDEWEB)

    Warne, L.K.; Merewether, K.O.; Chen, K.C.; Jorgenson, R.E.; Morris, M.E.; Solberg, J.E.; Lewis, J.G. [Sandia National Labs., Albuquerque, NM (United States); Derr, W. [Derr Enterprises, Albuquerque, NM (United States)

    1996-07-01

    Test data on canonical weapon-like fixtures are used to validate previously developed analytical bounding results. The test fixtures were constructed to simulate (but be slightly worse than) weapon ports of entry but have known geometries (and electrical points of contact). The exterior of the test fixtures exhibited exterior resonant enhancement of the incident fields at the ports of entry with magnitudes equal to those of weapon geometries. The interior consisted of loaded transmission lines adjusted to maximize received energy or voltage but incorporating practical weapon geometrical constraints. New analytical results are also presented for bounding the energies associated with multiple bolt joints and for bounding the exterior resonant enhancement of the exciting fields.

  18. Self-Assembly of Nanocomponents into Composite Structures: Derivation and Simulation of Langevin Equations

    OpenAIRE

    Pankavich, Stephen; Shreif, Zeina; Miao, Yinglong; Ortoleva, Peter

    2010-01-01

    The kinetics of the self-assembly of nanocomponents into a virus, nanocapsule, or other composite structure is analyzed via a multiscale approach. The objective is to achieve predictability and to preserve key atomic-scale features that underlie the formation and stability of the composite structures. We start with an all-atom description, the Liouville equation, and the order parameters characterizing nanoscale features of the system. An equation of Smoluchowski type for the stochastic dynam...

  19. Validation of Rheological Models of Typical Structures : an Attempt to Work Out an Insurance-Quality Procedure Validation des modèles rhéologiques sur ouvrages types : une tentative de démarche d'assurance-qualité

    Directory of Open Access Journals (Sweden)

    Meimon Y.

    2006-11-01

    Full Text Available For four years now, a validation of models for typical structuresgroup has been constituted inside the GRECO group on Rheology of Geomaterialssponsored by CNRS (French National Research Council. It has been working on the development of a methodology for validating rheological models of geomaterials. The aim was to reduce the gap between the theory and the practice of geomechanical computing. In a first step, the group work has been applied to shallow fondations. A complete validation process, which can be understood as an insurance-quality procedure, has been worked out, ranging from validation on the basis of homogeneous laboratory tests to validation based on boundary problems. Partial computerization of validation has been achieved with the help of a suitable software environment. A databank of laboratory and centrifuge tests has been created. An attempt has been made to define qualification criteria for models. Numerous rheological models have been applied, including some relatively sophisticated ones. This work has reached the point where the generalization of the procedure can been foreseen within the wider setting of the validation of geomechanical programs. Les travaux de validation Durant quatre ans (1986-1989, le groupe Validation des Modèles sur Ouvrages Typesdu GRECO CNRS Rhéologie des Géomatériaux , s'est efforcé de développer une méthodologie de validation des modèles rhéologiques de géomatériaux dans le but de réduire le décalage entre théorie et pratique des calculs en géomécanique, en appuyant son travail sur l'ouvrage type fondation superficielleet sur une collaboration étroite entre des équipes universitaires et des centres techniques et industriels. Les principaux travaux du groupe, constitué, d'une part de laboratoires universitaires français ou européen (École Centrale de Lyon (ECL, École Centrale de Paris (ECP, École Nationale des Travaux Publics de l'État (ENTPE, Institut de Mécanique de

  20. Construct Validity Of The Career Resilience Questionnaire

    OpenAIRE

    De Bruin, Gideon P.; Charlene C. Lew

    2002-01-01

    The construct validity of the Career Resilience Questionnaire (Fourie & VanVuuren, 1998) was investigated by means of an oblique multiple groups factor analysis.The highest factor structure coefficients of several of the items did not coincide with the respective factors that the items were postulated to measure. In addition, the correlations among the factors cast doubt on the independence of some of the constructs. Opsomming Die konstrukgeldigheid van die CareerResilience Questionnaire (Fo...

  1. Protein structure prediction: assembly of secondary structure elements by basin-hopping.

    Science.gov (United States)

    Hoffmann, Falk; Vancea, Ioan; Kamat, Sanjay G; Strodel, Birgit

    2014-10-20

    The prediction of protein tertiary structure from primary structure remains a challenging task. One possible approach to this problem is the application of basin-hopping global optimization combined with an all-atom force field. In this work, the efficiency of basin-hopping is improved by introducing an approach that derives tertiary structures from the secondary structure assignments of individual residues. This approach is termed secondary-to-tertiary basin-hopping and benchmarked for three miniproteins: trpzip, trp-cage and ER-10. For each of the three miniproteins, the secondary-to-tertiary basin-hopping approach successfully and reliably predicts their three-dimensional structure. When it is applied to larger proteins, correctly folded structures are obtained. It can be concluded that the assembly of secondary structure elements using basin-hopping is a promising tool for de novo protein structure prediction. PMID:25056272

  2. Stellar opacity validations

    Science.gov (United States)

    Le Pennec, M.; Turck-Chièze, S.; Ribeyre, X.; Ducret, J. E.

    2014-12-01

    This paper focuses on the radiative transfer in stars where opacities seem to raise problems : β-Cephei and solar-type stars. We first concentrate on the iron bump (log T = 5.25), responsible for β-Cephei pulsations through the κ-mechanism. To discriminate between the different opacity calculations used to predict their oscillations, new well-qualified calculations are used and compared to OP calculations. In parallel with this theoretical work, an experiment has been conducted at LULI 2000 in 2011 on iron and nickel. We show that this extended study pushes for the revision of the tables in the conditions corresponding to the iron bump region, at least for nickel. We will then deal with the Sun case for which we are preparing an opacity experiment on a high-energy laser, in some conditions of the radiative zone (T = [2 - 15 ×10^{6} K] and ρ = [0.2 - 150 g/cm^{3}]). To reach these high temperatures and densities at LTE and validate or not plasma effects and line widths, we are exploring an approach called the Double Ablation Front, driven by plasma radiative effects. The 1D simulations performed with the code CHIC show that with this technique, we could reach conditions equivalent to the conditions of half of the solar radiative zone.

  3. Spare Items validation

    International Nuclear Information System (INIS)

    There is an increasing difficulty for purchasing safety related spare items, with certifications by manufacturers for maintaining the original qualifications of the equipment of destination. The main reasons are, on the top of the logical evolution of technology, applied to the new manufactured components, the quitting of nuclear specific production lines and the evolution of manufacturers quality systems, originally based on nuclear codes and standards, to conventional industry standards. To face this problem, for many years different Dedication processes have been implemented to verify whether a commercial grade element is acceptable to be used in safety related applications. In the same way, due to our particular position regarding the spare part supplies, mainly from markets others than the american, C.N. Trillo has developed a methodology called Spare Items Validation. This methodology, which is originally based on dedication processes, is not a single process but a group of coordinated processes involving engineering, quality and management activities. These are to be performed on the spare item itself, its design control, its fabrication and its supply for allowing its use in destinations with specific requirements. The scope of application is not only focussed on safety related items, but also to complex design, high cost or plant reliability related components. The implementation in C.N. Trillo has been mainly curried out by merging, modifying and making the most of processes and activities which were already being performed in the company. (Author)

  4. Validation scheme for diagnostic tests

    International Nuclear Information System (INIS)

    The aim was to develop a scheme for the validation of assays developed in the research laboratory for the successful transfer and implementation in the diagnostic laboratory. Although logistically, temporally and economically challenging, proper validation minimizes the chance of failure and increases the possibility of successful transfer and implementation in the diagnostic laboratory. A properly validated assay, which includes good design, good quality control and good documentation, reduces the chances of liability and increases confidence in the assay both nationally and internationally

  5. SHIELD verification and validation report

    Energy Technology Data Exchange (ETDEWEB)

    Boman, C.

    1992-02-01

    This document outlines the verification and validation effort for the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system code. Along with its predecessors, SHIELD has been in use at the Savannah River Site (SRS) for more than ten years. During this time the code has been extensively tested and a variety of validation documents have been issued. The primary function of this report is to specify the features and capabilities for which SHIELD is to be considered validated, and to reference the documents that establish the validation.

  6. Validating and Investigating Reliability of Comprehensive Feeding Practices Questionnaire

    Directory of Open Access Journals (Sweden)

    Saeid Doaei

    2013-03-01

    Full Text Available Background: The present research aims to validate and discuss the reliability of Comprehensive Feeding Practices Questionnaire (CFPQ. Materials and Methods: In this cross-sectional study, 150 mothers with 3-6 year old children in the city of Rasht were selected through cluster random sampling from the public and private kindergartens in 2010. After being confident about the translation validity, the degree of validation (content and structure and validity (test-retest reliability and internal consistency of the questionnaire was examined. Results: The degree of validation of questionnaire content, except questions 2, 16 and 46, was at a high level and these three questions were omitted. The method of the consistency of factors and total scores of the questionnaire was used to study the validation of structure, which was satisfactory and varied between 0.30-0.72. The validity of questionnaire was examined through test-retest and Cronbach's alpha methods. The Intraclass Correlation Coefficient (ICC was between 0.80-0.91 and Cronbach's alpha was between 0.80-0.90. Conclusion: In general, the Comprehensive Feeding Practices Questionnaire (CFPQ was proved to be valid and with respect to the results obtained from the present research, it can be used in the research on child diet.

  7. The measurement of instrumental ADL: content validity and construct validity

    DEFF Research Database (Denmark)

    Avlund, K; Schultz-Larsen, K; Kreiner, S

    1993-01-01

    A new measure of Instrumental Activities of Daily Living (IADL), which is able to discriminate among the large group of elderly who do not depend on help, was tested for content validity and construct validity. Most assessments of functional ability include Physical ADL (PADL) and Instrumental ADL....... The measure of Instrumental ADL included 30 activities in relation to tiredness and reduced speed. Construct validity was tested by the Rasch model for item analysis; internal validity was specifically addressed by assessing the homogeneity of items under different conditions. The Rasch item analysis...... of IADL showed that 14 items could be combined into two qualitatively different additive scales. The IADL-measure complies with demands for content validity, distinguishes between what the elderly actually do, and what they are capable of doing, and is a good discriminator among the group of elderly...

  8. Experimental validation of UTDefect

    International Nuclear Information System (INIS)

    This study reports on conducted experiments and computer simulations of ultrasonic nondestructive testing (NDT). Experiments and simulations are compared with the purpose of validating the simulation program UTDefect. UTDefect simulates ultrasonic NDT of cracks and some other defects in isotropic and homogeneous materials. Simulations for the detection of surface breaking cracks are compared with experiments in pulse-echo mode on surface breaking cracks in carbon steel plates. The echo dynamics are plotted and compared with the simulations. The experiments are performed on a plate with thickness 36 mm and the crack depths are 7.2 mm and 18 mm. L- and T-probes with frequency 1, 2 and 4 MHz and angels 45, 60 and 70 deg are used. In most cases the probe and the crack is on opposite sides of the plate, but in some cases they are on the same side. Several cracks are scanned from two directions. In total 53 experiments are reported for 33 different combinations. Generally the simulations agree well with the experiments and UTDefect is shown to be able to, within certain limits, perform simulations that are close to experiments. It may be concluded that: For corner echoes the eight 45 deg cases and the eight 60 deg cases show good agreement between experiments and UTDefect, especially for the 7.2 mm crack. The amplitudes differ more for some cases where the defect is close to the probe and for the corner of the 18 mm crack. For the two 70 deg cases there are too few experimental values to compare the curve shapes, but the amplitudes do not differ too much. The tip diffraction echoes also agree well in general. For some cases, where the defect is close to the probe, the amplitudes differ more than 10-15 dB, but for all but two cases the difference in amplitude is less than 7 dB. 6 refs

  9. Developing a validation for environmental sustainability

    Science.gov (United States)

    Adewale, Bamgbade Jibril; Mohammed, Kamaruddeen Ahmed; Nawi, Mohd Nasrun Mohd; Aziz, Zulkifli

    2016-08-01

    One of the agendas for addressing environmental protection in construction is to reduce impacts and make the construction activities more sustainable. This important consideration has generated several research interests within the construction industry, especially considering the construction damaging effects on the ecosystem, such as various forms of environmental pollution, resource depletion and biodiversity loss on a global scale. Using Partial Least Squares-Structural Equation Modeling technique, this study validates environmental sustainability (ES) construct in the context of large construction firms in Malaysia. A cross-sectional survey was carried out where data was collected from Malaysian large construction firms using a structured questionnaire. Results of this study revealed that business innovativeness and new technology are important in determining environmental sustainability (ES) of the Malaysian construction firms. It also established an adequate level of internal consistency reliability, convergent validity and discriminant validity for each of this study's constructs. And based on this result, it could be suggested that the indicators for organisational innovativeness dimensions (business innovativeness and new technology) are useful to measure these constructs in order to study construction firms' tendency to adopt environmental sustainability (ES) in their project execution.

  10. Diversity Management: Seeking Validation

    Directory of Open Access Journals (Sweden)

    M. Tony Bledsoe

    2011-01-01

    Full Text Available Diversity management is widely valued in higher education today, but closer examination often reveals a lack of action to support the level of diversity that institutions claim to embrace in many of their strategic documents. This paper includes an assessment of diversity management within South Carolina’s technical colleges and an examination of survey results.  It is a companion study to a prior study of diversity in North Carolina Independent Colleges and Universities (NCICU.  The purpose of that research was to review campus-wide documents and structure of schools in the NCICU to determine diversity transparency (Bledsoe/Oatsvall.

  11. Ecological reality and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Cale, Jr, W. G.; Shugart, H. H.

    1980-01-01

    Definitions of model realism and model validation are developed. Ecological and mathematical arguments are then presented to show that model equations which explicitly treat ecosystem processes can be systematically improved such that greater realism is attained and the condition of validity is approached. Several examples are presented.

  12. Cleaning Validation of Fermentation Tanks

    DEFF Research Database (Denmark)

    Salo, Satu; Friis, Alan; Wirtanen, Gun

    2008-01-01

    Reliable test methods for checking cleanliness are needed to evaluate and validate the cleaning process of fermentation tanks. Pilot scale tanks were used to test the applicability of various methods for this purpose. The methods found to be suitable for validation of the clenlinees were visula o...

  13. Cultural Validation of the Maslach Burnout Inventory for Korean Students

    Science.gov (United States)

    Shin, Hyojung; Puig, Ana; Lee, Jayoung; Lee, Ji Hee; Lee, Sang Min

    2011-01-01

    The purpose of this study was to examine the factorial validity of the MBI-SS in Korean students. Specifically, we investigated whether the original three-factor structure of the MBI-SS was appropriate for use with Korean students. In addition, by running multi-group structural equation model analyses with factorial invariance tests simultaneously…

  14. Distributed Trust Management for Validating SLA Choreographies

    Science.gov (United States)

    Haq, Irfan Ul; Alnemr, Rehab; Paschke, Adrian; Schikuta, Erich; Boley, Harold; Meinel, Christoph

    For business workflow automation in a service-enriched environment such as a grid or a cloud, services scattered across heterogeneous Virtual Organizations (VOs) can be aggregated in a producer-consumer manner, building hierarchical structures of added value. In order to preserve the supply chain, the Service Level Agreements (SLAs) corresponding to the underlying choreography of services should also be incrementally aggregated. This cross-VO hierarchical SLA aggregation requires validation, for which a distributed trust system becomes a prerequisite. Elaborating our previous work on rule-based SLA validation, we propose a hybrid distributed trust model. This new model is based on Public Key Infrastructure (PKI) and reputation-based trust systems. It helps preventing SLA violations by identifying violation-prone services at service selection stage and actively contributes in breach management at the time of penalty enforcement.

  15. How to Validate Design : Validating Design Using Target Group Interview

    OpenAIRE

    Uhmavaara, Riikka

    2016-01-01

    This thesis explores the topic of design validation. The theoretical aspects concentrate on design process and different attributes of design that can be measured. The objective was to gain knowledge on how design solutions can be validated or improved. The aim was also to find out if the validation data could be useful for designers. In addition to the theory, this thesis consists of a practical part, which includes a design case for a client, and a target group interview that aims to valida...

  16. Empirical validation of the team work engagement construct

    OpenAIRE

    Costa, P.; Passos, A.; Bakker, A.

    2014-01-01

    This article presents an empirical validation of the construct of team work engagement. Two different samples were used to test the hypotheses. Results from convergent and discriminant validity are presented as well as confirmatory factor analysis that explores the construct’s factor structure. Results support the idea that team- and individual-level work engagement are two different, yet related, constructs. However, data do not support the factorial invariance across levels: At the team lev...

  17. The Construct Validity of Passive-Aggressive Personality Disorder

    OpenAIRE

    Hopwood, Christopher J.; Morey, Leslie C.; Markowitz, John C.; Pinto, Anthony; Skodol, Andrew E.; Gunderson, John G.; Zanarini, Mary C.; Shea, M. Tracie; YEN, SHIRLEY; McGlashan, Thomas H.; Ansell, Emily B.; Grilo, Carlos M.; Sanislow, Charles A.

    2009-01-01

    Although Passive Aggressive personality disorder (PAPD) plays an important role in many theories of personality pathology, it was consigned to the appendix of the fourth edition of the DSM. The scientific basis of this decision has been questioned, but several controversies persist regarding PAPD, including its structure, content validity, overlap with other PDs, and relations to validating variables such as personality traits, childhood experiences, and clinically relevant correlates. This s...

  18. The impact of job complexity and study design on situational and behavior description interview validity

    OpenAIRE

    Huffcutt, Allen I.; Roth, Philip L.; James M. Conway; Klehe, Ute Christine

    2004-01-01

    The primary purpose of this investigation was to test two key characteristics hypothesized to influence the validity of situational (SI) and behavior description (BDI) structured interviews. A meta-analysis of 54 studies with a total sample size of 5536 suggested that job complexity influences the validity of SIs, with decreased validity for high-complexity jobs, but does not influence the validity of BDIs. And, results indicated a main effect for study design across both SIs and BDIs, with p...

  19. Validation of EAF-2005 data

    International Nuclear Information System (INIS)

    Full text: Validation procedures applied on EAF-2003 starter file, which lead to the production of EAF-2005 library, are described. The results in terms of reactions with assigned quality scores in EAF-20005 are given. Further the extensive validation against the recent integral data is discussed together with the status of the final report 'Validation of EASY-2005 using integral measurements'. Finally, the novel 'cross section trend analysis' is presented with some examples of its use. This action will lead to the release of improved library EAF-2005.1 at the end of 2005, which shall be used as the starter file for EAF-2007. (author)

  20. A Survey on Internal Validity Measure for Cluster Validation

    Directory of Open Access Journals (Sweden)

    L.Jegatha Deborah

    2010-12-01

    Full Text Available Data Clustering is a technique of finding similar characteristics among the data set which are always hidden in nature and grouping them into groups, called as clusters. Different clustering algorithms exhibit different results, since they are very sensitive to the characteristics of original data set especially noise and dimension. The quality of such clustering process determines the purity of cluster and hence it is very important to evaluate the results of the clustering algorithm. Due to this, Cluster validation activity had been a major and challenging task. The major factor which influences cluster validation is the internal cluster validity measure of choosing the optimal number of clusters. The main objective of this article is to present a detailed description of the mathematical working of few cluster validity indices and not all, to classify these indices and to explore the ideas for the future promotion of the work in the domain of cluster validation. In addition to this, a maximization objective function is defined assuming to provide a cluster validation activity.

  1. Reparameterization of All-Atom Dipalmitoylphosphatidylcholine Lipid Parameters Enables Simulation of Fluid Bilayers at Zero Tension

    OpenAIRE

    Sonne, Jacob; Jensen, Morten Ø.; Hansen, Flemming Y.; Hemmingsen, Lars Bo Stegeager; Peters, Günther H.

    2007-01-01

    Molecular dynamics simulations of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers using the CHARMM27 force field in the tensionless isothermal-isobaric (NPT) ensemble give highly ordered, gel-like bilayers with an area per lipid of ∼48 Å2. To obtain fluid (Lα) phase properties of DPPC bilayers represented by the CHARMM energy function in this ensemble, we reparameterized the atomic partial charges in the lipid headgroup and upper parts of the acyl chains. The new charges were determined ...

  2. Mechanism and kinetics of peptide partitioning into membranes from all-atom simulations of thermostable peptides

    OpenAIRE

    Ulmschneider, Martin B.; Doux, Jacques P F; Killian, J. Antoinette; Smith, Jeremy C.; Ulmschneider, Jakob P.

    2010-01-01

    Partitioning properties of transmembrane (TM) polypeptide segments directly determine membrane protein folding, stability, and function, and their understanding is vital for rational design of membrane active peptides. However, direct determination of water-to-bilayer transfer of TM peptides has proved difficult. Experimentally, sufficiently hydrophobic peptides tend to aggregate, while atomistic computer simulations at physiological temperatures cannot yet reach the long time scales required...

  3. BioBlender: Fast and Efficient All Atom Morphing of Proteins Using Blender Game Engine

    OpenAIRE

    Zini, Maria Francesca; Porozov, Yuri; Andrei, Raluca Mihaela; Loni, Tiziana; Caudai, Claudia; Zoppè, Monica

    2010-01-01

    In this and the associated article 'BioBlender: A Software for Intuitive Representation of Surface Properties of Biomolecules', (Andrei et al) we present BioBlender as a complete instrument for the elaboration of motion (here) and the visualization (Andrei et al) of proteins and other macromolecules, using instruments of computer graphics. A vast number of protein (if not most) exert their function through some extent of motion. Despite recent advances in higly performant methods, it is very ...

  4. ALEGRA -- code validation: Experiments and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Chhabildas, L.C.; Konrad, C.H.; Mosher, D.A.; Reinhart, W.D; Duggins, B.D.; Rodeman, R.; Trucano, T.G.; Summers, R.M.; Peery, J.S.

    1998-03-16

    In this study, the authors are providing an experimental test bed for validating features of the ALEGRA code over a broad range of strain rates with overlapping diagnostics that encompass the multiple responses. A unique feature of the Arbitrary Lagrangian Eulerian Grid for Research Applications (ALEGRA) code is that it allows simultaneous computational treatment, within one code, of a wide range of strain-rates varying from hydrodynamic to structural conditions. This range encompasses strain rates characteristic of shock-wave propagation (10{sup 7}/s) and those characteristic of structural response (10{sup 2}/s). Most previous code validation experimental studies, however, have been restricted to simulating or investigating a single strain-rate regime. What is new and different in this investigation is that the authors have performed well-instrumented experiments which capture features relevant to both hydrodynamic and structural response in a single experiment. Aluminum was chosen for use in this study because it is a well characterized material--its EOS and constitutive material properties are well defined over a wide range of loading rates. The current experiments span strain rate regimes of over 10{sup 7}/s to less than 10{sup 2}/s in a single experiment. The input conditions are extremely well defined. Velocity interferometers are used to record the high strain-rate response, while low strain rate data were collected using strain gauges.

  5. Base Flow Model Validation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is the systematic "building-block" validation of CFD/turbulence models employing a GUI driven CFD code (RPFM) and existing as well as new data sets...

  6. Validation studies and proficiency testing.

    Science.gov (United States)

    Ankilam, Elke; Heinze, Petra; Kay, Simon; Van den Eede, Guy; Popping, Bert

    2002-01-01

    Genetically modified organisms (GMOs) entered the European food market in 1996. Current legislation demands the labeling of food products if they contain GMO, as assessed for each ingredient of the product. To create confidence in the testing methods and to complement enforcement requirements, there is an urgent need for internationally validated methods, which could serve as reference methods. To date, several methods have been submitted to validation trials at an international level; approaches now exist that can be used in different circumstances and for different food matrixes. Moreover, the requirement for the formal validation of methods is clearly accepted; several national and international bodies are active in organizing studies. Further validation studies, especially on the quantitative polymerase chain reaction methods, need to be performed to cover the rising demand for new extraction methods and other background matrixes, as well as for novel GMO constructs. PMID:12083280

  7. White Bear Suppression Inventory: Structure, Reliability and Validity of the Chinese Version%思维压抑量表:中文版的结构、信度及效度

    Institute of Scientific and Technical Information of China (English)

    Marcus A.Rodriguez; 贾珂; 钱铭怡

    2012-01-01

    Objective: To test the reliability and validity of the Chinese version of White Bear Suppression Inventory (WBSI) among a Chinese student sample. Methods: A convenience sample of 125 college students completed the WBSI and Beck Depression Inventory; a randomly selected subsample of 33 students participated in the retest in 4 weeks. A second sample of 383 college students completed the WBSI, Penn State Worry Questionnaire, Impact of Event Scale-Revised, and Thought-Action Fusion Scale. A third sample of 334 college students completed the WBSI, State-Trait Anxiety Inventory, Padua Inventory, and a measure of Chinese superstition. Results: EFA results revealed 3 factors (intrusive thoughts, thought suppression and self-distraction), which accounted for 52.4% of the total variance. CFA results provided support for a 3-factor model (x2/d?3.45, CFI=0.91, TU=0.89, RMSEA=0.07, SRMR=0.06). Internal consistency and test-retest coefficients for the WBSI梩otal were 0.87 and 0.59 respectively. WBSI-total scores were significantly higher for female participants. Criterion-related validity results revealed positive significant correlations between WBSI and depression (r=0.29), trait-anxiety (r=0.42), PTSD symptomology (r=0.42), OCD (0.30), and GAD (r=0.44). SEM results also provided support for a model wherein thought suppression mediates the relationship between superstition and obsessive-compulsive symptoms. Conclusion: The Chinese version of the WBSI is found to have good reliability and validity.%目的:在大学生群体中对思维压抑量表(White Bear Suppression Inventory,WBSI)进行修订并考察其信效度.方法:采用方便取样方法,对样本一的125名大学生施测WBSI及贝克抑郁问卷,以检验该量表的效度,并随机选取其中33名学生,在初测4周后进行了重测;对样本二的383名大学生施测WBSI、宾州忧虑问卷、事件影响量表-修订版及想法行为混淆量表.对样本三的334名大学生施测WBSI、帕多瓦量

  8. Validation: an overview of definitions

    International Nuclear Information System (INIS)

    The term validation is featured prominently in the literature on radioactive high-level waste disposal and is generally understood to be related to model testing using experiments. In a first class, validation is linked to the goal of predicting the physical world as faithfully as possible but is unattainable and unsuitable for setting goals for the safety analyses. In a second class, validation is associated to split-sampling or to blind-tests predictions. In the third class of definition, validation focuses on the quality of the decision-making process. Most prominent in the present review is the observed lack of use of the term validation in the field of low-level radioactive waste disposal. The continued informal use of the term validation in the field of high level wastes disposals can become cause for misperceptions and endless speculations. The paper proposes either abandoning the use of this term or agreeing to a definition which would be common to all. (J.S.). 29 refs

  9. Validation metrics for turbulent plasma transport

    Science.gov (United States)

    Holland, C.

    2016-06-01

    Developing accurate models of plasma dynamics is essential for confident predictive modeling of current and future fusion devices. In modern computer science and engineering, formal verification and validation processes are used to assess model accuracy and establish confidence in the predictive capabilities of a given model. This paper provides an overview of the key guiding principles and best practices for the development of validation metrics, illustrated using examples from investigations of turbulent transport in magnetically confined plasmas. Particular emphasis is given to the importance of uncertainty quantification and its inclusion within the metrics, and the need for utilizing synthetic diagnostics to enable quantitatively meaningful comparisons between simulation and experiment. As a starting point, the structure of commonly used global transport model metrics and their limitations is reviewed. An alternate approach is then presented, which focuses upon comparisons of predicted local fluxes, fluctuations, and equilibrium gradients against observation. The utility of metrics based upon these comparisons is demonstrated by applying them to gyrokinetic predictions of turbulent transport in a variety of discharges performed on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)], as part of a multi-year transport model validation activity.

  10. Quality data validation: Comprehensive approach to environmental data validation

    International Nuclear Information System (INIS)

    Environmental data validation consists of an assessment of three major areas: analytical method validation; field procedures and documentation review; evaluation of the level of achievement of data quality objectives based in part on PARCC parameters analysis and expected applications of data. A program utilizing matrix association of required levels of validation effort and analytical levels versus applications of this environmental data was developed in conjunction with DOE-ID guidance documents to implement actions under the Federal Facilities Agreement and Consent Order in effect at the Idaho National Engineering Laboratory. This was an effort to bring consistent quality to the INEL-wide Environmental Restoration Program and database in an efficient and cost-effective manner. This program, documenting all phases of the review process, is described here

  11. Process validation for radiation processing

    International Nuclear Information System (INIS)

    Process validation concerns the establishment of the irradiation conditions that will lead to the desired changes of the irradiated product. Process validation therefore establishes the link between absorbed dose and the characteristics of the product, such as degree of crosslinking in a polyethylene tube, prolongation of shelf life of a food product, or degree of sterility of the medical device. Detailed international standards are written for the documentation of radiation sterilization, such as EN 552 and ISO 11137, and the steps of process validation that are described in these standards are discussed in this paper. They include material testing for the documentation of the correct functioning of the product, microbiological testing for selection of the minimum required dose and dose mapping for documentation of attainment of the required dose in all parts of the product. The process validation must be maintained by reviews and repeated measurements as necessary. This paper presents recommendations and guidance for the execution of these components of process validation. (author)

  12. Validating LES for Jet Aeroacoustics

    Science.gov (United States)

    Bridges, James

    2011-01-01

    Engineers charged with making jet aircraft quieter have long dreamed of being able to see exactly how turbulent eddies produce sound and this dream is now coming true with the advent of large eddy simulation (LES). Two obvious challenges remain: validating the LES codes at the resolution required to see the fluid-acoustic coupling, and the interpretation of the massive datasets that result in having dreams come true. This paper primarily addresses the former, the use of advanced experimental techniques such as particle image velocimetry (PIV) and Raman and Rayleigh scattering, to validate the computer codes and procedures used to create LES solutions. It also addresses the latter problem in discussing what are relevant measures critical for aeroacoustics that should be used in validating LES codes. These new diagnostic techniques deliver measurements and flow statistics of increasing sophistication and capability, but what of their accuracy? And what are the measures to be used in validation? This paper argues that the issue of accuracy be addressed by cross-facility and cross-disciplinary examination of modern datasets along with increased reporting of internal quality checks in PIV analysis. Further, it is argued that the appropriate validation metrics for aeroacoustic applications are increasingly complicated statistics that have been shown in aeroacoustic theory to be critical to flow-generated sound.

  13. Independent validation of ultrasonic inspection

    International Nuclear Information System (INIS)

    As a part of its inspection strategy for the Sizewell-B PWR station, the Central Electricity Generating Board (in part now Nuclear Electric) decided that the ultrasonic inspection procedures for the incredibility of failure components would be subjected to independent confirmation of their adequacy. The incorporation of validation into a large-scale inspection strategy was unique at the time (1982), indeed remains so today. The CEGB's general philosophy is one of diversity, redundancy and validation. In order to carry out independent validation of the specific procedures and ultrasonic operators to be used during the manufacture and in-service inspection of the reactor pressure vessel and steam plant components, the Inspection Validation Centre (IVC) has operated as a contractor to Nuclear Electric with special arrangements in place to guarantee independence. The setting-up and early methods of operation of IVC are briefly reviewed, the most recent operational experience summarized and the technical significance of the validations to date discussed. (author). 1 fig

  14. Key problems in validation of intelligent models

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; MA Ping; YANG Ming; WANG Zi-cai

    2009-01-01

    To provide a realistic simulation environment for users, intelligent models have become key compo-nents in military simulations. After the analysis of modeling nature of intelligent models, the validation criteria for defining the validation points and validation metrics for measuring the agreements between human expertsand intelligent models were presented. Further, such methods as graphical comparison, feature analysis and face validation were discussed according to the characteristics of intelligent models. Based on the validation cri-teria, validation metrics and validation methods, the intelligent models can be effectively validated, which has been proved in current developed intelligent models.

  15. Validation of TRAB-3D

    International Nuclear Information System (INIS)

    TRAB-3D is a reactor dynamics code with three-dimensional neutronics coupled to core and circuit thermal-hydraulics. The code, entirely developed at VTT, can be used in transient and accident analyses of boiling (BWR) and pressurized water (PWR) reactors with rectangular fuel bundle geometry. The validation history of TRAB-3D includes calculation of international benchmark exercises, as well as comparisons with measured data from real plant transients. The most recent validation case is a load rejection test performed at the Olkiluoto 1 nuclear power plant in 1998 in connection with the power uprating project. The fact that there is local power measurement data available from this test makes it a suitable case for three-dimensional core model validation. The agreement between the results of the TRAB-3D calculation and the measurements is very good. (orig.)

  16. RELIABLE VALIDATION BASED ON OPTICAL FLOW VISUALIZATION FOR CFD SIMULATIONS

    Institute of Scientific and Technical Information of China (English)

    姜宗林

    2003-01-01

    A reliable validation based on the optical flow visualization for numerical simulations of complex flowfields is addressed in this paper.Several test cases,including two-dimensional,axisymmetric and three-dimensional flowfields,were presented to demonstrate the effectiveness of the validation and gain credibility of numerical solutions of complex flowfields.In the validation,images of these flowfields were constructed from numerical results based on the principle of the optical flow visualization,and compared directly with experimental interferograms.Because both experimental and numerical results are of identical physical representation,the agreement between them can be evaluated effectively by examining flow structures as well as checking discrepancies in density.The study shows that the reliable validation can be achieved by using the direct comparison between numerical and experiment results without any loss of accuracy in either of them.

  17. Construction and initial validation of the Multiracial Experiences Measure (MEM).

    Science.gov (United States)

    Yoo, Hyung Chol; Jackson, Kelly F; Guevarra, Rudy P; Miller, Matthew J; Harrington, Blair

    2016-03-01

    This article describes the development and validation of the Multiracial Experiences Measure (MEM): a new measure that assesses uniquely racialized risks and resiliencies experienced by individuals of mixed racial heritage. Across 2 studies, there was evidence for the validation of the 25-item MEM with 5 subscales including Shifting Expressions, Perceived Racial Ambiguity, Creating Third Space, Multicultural Engagement, and Multiracial Discrimination. The 5-subscale structure of the MEM was supported by a combination of exploratory and confirmatory factor analyses. Evidence of criterion-related validity was partially supported with MEM subscales correlating with measures of racial diversity in one's social network, color-blind racial attitude, psychological distress, and identity conflict. Evidence of discriminant validity was supported with MEM subscales not correlating with impression management. Implications for future research and suggestions for utilization of the MEM in clinical practice with multiracial adults are discussed. (PsycINFO Database Record PMID:26460977

  18. Pyroshock data analysis-The GCPP validation procedure

    Science.gov (United States)

    Piersol, Allan G.

    2002-05-01

    This procedure was developed for validating pyroshock data by Powers and the author, using techniques originated by Gaberson and Chalmers in validating naval shock data at lower frequencies and subsequently modified. It requires that the acceleration time history be single and double integrated to obtain a velocity and a displacement time history, which is to be examined. Valid data look like a low-pass filtered acceleration time history which is not integrated. The maximum resulting displacement should approximate the independently measured displacement (often near zero) or that previously computed analytically for the structure at the measured location. In addition, the positive and negative SRS are computed and compared. Valid data usually show similar spectral content.

  19. A further validation of the Minnesota Borderline Personality Disorder Scale.

    Science.gov (United States)

    Rojas, Elizabeth C; Cummings, Jenna R; Bornovalova, Marina A; Hopwood, Christopher J; Racine, Sarah E; Keel, Pamela K; Sisk, Cheryl L; Neale, Michael; Boker, Steven; Burt, S Alexandra; Klump, Kelly L

    2014-04-01

    Previous research indicates that borderline personality disorder (BPD) is well conceptualized as a dimensional construct that can be represented using normal personality traits. A previous study successfully developed and validated a BPD measure embedded within a normal trait measure, the Minnesota Borderline Personality Disorder Scale (MBPD). The current study performed a further validation of the MBPD by examining its convergent validity, external correlates, and heritability in a sample of 429 female twins. The MBPD correlated strongly with the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) screener for BPD and moderately with external correlates. Moreover, the MBPD and SCID-II screener exhibited very similar patterns of external correlations. Additionally, results indicated that the genetic and environmental influences on MBPD overlap with the genetic and environmental influences on the SCID-II screener, which suggests that these scales are measuring the same construct. These data provide further evidence for the construct validity of the MBPD. PMID:24364505

  20. CRM SCALE DEVELOPMENT & VALIDATION IN INDIAN BANKING SECTOR

    Directory of Open Access Journals (Sweden)

    Arun Kumar Agariya

    2012-04-01

    Full Text Available The aim of this paper is to develop a reliable and valid CRM (Customer relationship management scale specifically catering to Indian banking sector. An exhaustive review of literature on CRM was followed by depth interview and questionnaire survey. Exploratory factor analysis was followed by confirmatory factor analysis, which was presented in three forms; the single factor model, covariance model and the structural model. The covariance model shows CRM in Indian banking sector as a multidimensional construct comprising of fact ors namely organizational structure and customer support, service quality, trust, technology, personalization and market orientation. The structural model validates the previously extracted factors along with their indicators. The findings of this study validate the long held belief that CRM is a multidimensional construct and serves as a critical success factor for business performance. Since this study was conducted in context of Indian banking sector, the generalizability of the CRM scale has to be tested in other countries. A fair amount of literature on Indian banking sector dealt with identifying factors explaining the constructs of quality, value or satisfaction. But there is paucity of research pertaining to industry specific CRM scale development and validation. This study is an attempt to bridge this gap in the existing literature. It provides a conceptually validated CRM scale catering to Indian banking sector, which can help the managers in implementing the CRM in an effective manner and also can be used as a tool to identify the major areas requiring attention.

  1. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars-Part I: Model structure, simulation of bounded rationality, and model validation

    International Nuclear Information System (INIS)

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated

  2. Validation of the Buss-Perry Aggression Questionnaire-Short Form among Portuguese juvenile delinquents.

    Science.gov (United States)

    Pechorro, Pedro; Barroso, Ricardo; Poiares, Carlos; Oliveira, João Pedro; Torrealday, Ohiana

    2016-01-01

    The aim of the present study was to validate the Buss-Perry Aggression Questionnaire-Short Form (BPAQ-SF) among Portuguese juvenile delinquents. With a total sample of 237 male participants, subdivided into an incarcerated forensic sample (n=192) and a community sample (n=45), the Portuguese version of the BPAQ-SF demonstrated good psychometric properties in terms of factor structure, internal consistency, convergent validity, discriminant validity, predictive validity and known-groups validity that generally justify its use among Portuguese youth. Statistically significant associations were found with drug use and alcohol abuse. PMID:26303901

  3. A Contribution to Documenting and Validating Dynamic Interaction Effects

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2007-01-01

    On structures carrying humans (e.g. floors, grandstands in stadia etc.) there may be two different types of crowds present: Active and passive crowds of people. The active crowd, comprising people in motion, may generate dynamic loads causing the structure to vibrate. The passive (stationary) crowd......, e.g. humans sitting or standing on the structure, interact dynamically with the structure in a passive sense and this crowd influences the dynamic characteristics of the structure such as its damping capacity. The paper looks into the dynamic interaction between the passive (stationary) crowd...... and a floor in vertical motion. The mechanism of crowd-structure interaction is not well understood and the primary aim of the paper is to present results of experimental investigations documenting effects of crowd-structure interaction and to exploring the validity of a crowd-structure interaction model...

  4. Assessment of juveniles testimonies’ validity

    Directory of Open Access Journals (Sweden)

    Dozortseva E.G.

    2015-12-01

    Full Text Available The article presents a review of the English language publications concerning the history and the current state of differential psychological assessment of validity of testimonies produced by child and adolescent victims of crimes. The topicality of the problem in Russia is high due to the tendency of Russian specialists to use methodical means and instruments developed abroad in this sphere for forensic assessments of witness testimony veracity. A system of Statement Validity Analysis (SVA by means of Criteria-Based Content Analysis (CBCA and Validity Checklist is described. The results of laboratory and field studies of validity of CBCA criteria on the basis of child and adult witnesses are discussed. The data display a good differentiating capacity of the method, however, a high level of error probability. The researchers recommend implementation of SVA in the criminal investigation process, but not in the forensic assessment. New perspective developments in the field of methods for differentiation of witness statements based on the real experience and fictional are noted. The conclusion is drawn that empirical studies and a special work for adaptation and development of new approaches should precede their implementation into Russian criminal investigation and forensic assessment practice

  5. Validity of Management Control Topoi

    DEFF Research Database (Denmark)

    Nørreklit, Lennart; Nørreklit, Hanne; Israelsen, Poul

    2004-01-01

    The validity of research and company topoi for constructing/analyzing relaity is analyzed as the integration of the four aspects (dimensions): fact, possibility (logic), value and comunication. Main stream, agency theory and social constructivism are critizied for reductivism (incomplete...

  6. Generalization of Selection Test Validity.

    Science.gov (United States)

    Colbert, G. A.; Taylor, L. R.

    1978-01-01

    This is part three of a three-part series concerned with the empirical development of homogeneous families of insurance company jobs based on data from the Position Analysis Questionnaire (PAQ). This part involves validity generalizations within the job families which resulted from the previous research. (Editor/RK)

  7. Validation process of simulation model

    International Nuclear Information System (INIS)

    It is presented a methodology on empirical validation about any detailed simulation model. This king of validation it is always related with an experimental case. The empirical validation has a residual sense, because the conclusions are based on comparisons between simulated outputs and experimental measurements. This methodology will guide us to detect the fails of the simulation model. Furthermore, it can be used a guide in the design of posterior experiments. Three steps can be well differentiated: Sensitivity analysis. It can be made with a DSA, differential sensitivity analysis, and with a MCSA, Monte-Carlo sensitivity analysis. Looking the optimal domains of the input parameters. It has been developed a procedure based on the Monte-Carlo methods and Cluster techniques, to find the optimal domains of these parameters. Residual analysis. This analysis has been made on the time domain and on the frequency domain, it has been used the correlation analysis and spectral analysis. As application of this methodology, it is presented the validation carried out on a thermal simulation model on buildings, Esp., studying the behavior of building components on a Test Cell of LECE of CIEMAT. (Author) 17 refs

  8. Automatic validation of numerical solutions

    DEFF Research Database (Denmark)

    Stauning, Ole

    1997-01-01

    This thesis is concerned with ``Automatic Validation of Numerical Solutions''. The basic theory of interval analysis and self-validating methods is introduced. The mean value enclosure is applied to discrete mappings for obtaining narrow enclosures of the iterates when applying these mappings wit...... the mean value enclosure of an integral operator and uses interval Bernstein polynomials for enclosing the solution. Two numerical examples are given, using two orders of approximation and using different numbers of discretization points.......This thesis is concerned with ``Automatic Validation of Numerical Solutions''. The basic theory of interval analysis and self-validating methods is introduced. The mean value enclosure is applied to discrete mappings for obtaining narrow enclosures of the iterates when applying these mappings with...... intervals as initial values. A modification of the mean value enclosure of discrete mappings is considered, namely the extended mean value enclosure which in most cases leads to even better enclosures. These methods have previously been described in connection with discretizing solutions of ordinary...

  9. A Validity Investigation of the Achievement Anxiety Test.

    Science.gov (United States)

    Plake, Barbara S.; And Others

    The concurrent validity of the Achievement Anxiety Test (AAT) and its factor structure are investigated to provide empirical evidence about the quality of AAT. State and trait anxiety were measured by State and Trait Anxiety Inventory (STAI), mathematics anxiety was assessed by a 24-item revised version of the 98-item Mathematics Anxiety Rating…

  10. Experimental assessment of validity of eddy current inspection

    OpenAIRE

    Yu. S. Agalidi; P. V. Kozhukhar; D. V. Lebeda

    2008-01-01

    Experiment has been executed for the purpose of optimization of diagnostic equipment kit. Numerical values of validity of threshold inspection (of coating thickness, roughness, structure, composition and thickness of metal of light-gage goods) have been got for set of comparing eddy current devices.

  11. Validating Two Questions in the Force Concept Inventory with Subquestions

    Science.gov (United States)

    Yasuda, Jun-ichiro; Taniguchi, Masa-aki

    2013-01-01

    In this study, we evaluate the structural validity of Q.16 and Q.7 in the Force Concept Inventory (FCI). We address whether respondents who answer Q.16 and Q.7 correctly actually have an understanding of the concepts of physics tested in the questions. To examine respondents' levels of understanding, we use subquestions that test them on concepts…

  12. Validation of the Seating and Mobility Script Concordance Test

    Science.gov (United States)

    Cohen, Laura J.; Fitzgerald, Shirley G.; Lane, Suzanne; Boninger, Michael L.; Minkel, Jean; McCue, Michael

    2009-01-01

    The purpose of this study was to develop the scoring system for the Seating and Mobility Script Concordance Test (SMSCT), obtain and appraise internal and external structure evidence, and assess the validity of the SMSCT. The SMSCT purpose is to provide a method for testing knowledge of seating and mobility prescription. A sample of 106 therapists…

  13. Understanding Foreign Language Learning Strategies: A Validation Study

    Science.gov (United States)

    Tragant, Elsa; Thompson, Marilyn S.; Victori, Mia

    2013-01-01

    The present work aims to contribute to our understanding of the underlying dimensions of language learning strategies in foreign language contexts. The study analyzes alternative factor structures underlying a recently developed instrument (Tragant and Victori, 2012) and it includes the age factor in the examination of its construct validity. The…

  14. Development and Validation of the Multidimensional State Boredom Scale

    Science.gov (United States)

    Fahlman, Shelley A.; Mercer-Lynn, Kimberley B.; Flora, David B.; Eastwood, John D.

    2013-01-01

    This article describes the development and validation of the Multidimensional State Boredom Scale (MSBS)--the first and only full-scale measure of state boredom. It was developed based on a theoretically and empirically grounded definition of boredom. A five-factor structure of the scale (Disengagement, High Arousal, Low Arousal, Inattention, and…

  15. Comparative Validity of the Shedler and Westen Assessment Procedure-200

    Science.gov (United States)

    Mullins-Sweatt, Stephanie N.; Widiger, Thomas A.

    2008-01-01

    A predominant dimensional model of general personality structure is the five-factor model (FFM). Quite a number of alternative instruments have been developed to assess the domains of the FFM. The current study compares the validity of 2 alternative versions of the Shedler and Westen Assessment Procedure (SWAP-200) FFM scales, 1 that was developed…

  16. Latino/a Values Scale: Development, Reliability, and Validity

    Science.gov (United States)

    Kim, Bryan S. K.; Soliz, Alicia; Orellana, Blanca; Alamilla, Saul G.

    2009-01-01

    This article describes the development of the Latino/a Values Scale (35 items, 14 reverse-worded). Evidence of reliability and validity are presented on the basis of three studies. An examination of the factor structure of the items suggests the presence of the following dimensions: cultural pride, simpatia, familismo, and espiritismo. (Contains 4…

  17. The Schizotypic Syndrome Questionnaire (SSQ): Psychometrics, validation and norms.

    NARCIS (Netherlands)

    Kampen, van D.

    2006-01-01

    Abstract This paper examines the psychometric properties (reliability and factor structure) and validity (relationship with various self-report measures and SPEM dysfunction) of the SSQ or Schizotypic Syndrome Questionnaire, a 108-item inventory for the measurement of 12 prodromal or schizotypic sym

  18. Measuring Elementary Student's Mathematics Motivation: A Validity Study

    Science.gov (United States)

    Orosco, Michael J.

    2016-01-01

    The psychometric properties of a 10-item math motivation scale were empirically validated with an independent sample consisting of 182 elementary-school students. Analysis of the model dimensionality supported a one-factor structure fit. Item parameter estimates from a Classical Test Theory framework revealed that most items were highly…

  19. Process chain validation in micro and nano replication

    DEFF Research Database (Denmark)

    Calaon, Matteo

    to remove technology barrier between lab-scale proof-of-principle and high-volume low-cost production of nantechnology based products. The aim of the current study was to develop methods and approaches to process chain validation for final polymer micro and nano structures replication. Fidelity between...... nm and process reproducibility within a range of ±8 nm. Therefore test structures provide a process calibration tool enabling definition of tolerance limits within micro and nano replication...

  20. Experimentally Validated Nonlinear Analysis of Bridge Plate Girders with Deformations

    Directory of Open Access Journals (Sweden)

    Kużawa Mieszko

    2015-09-01

    Full Text Available Comprehensive methodology of numerical nonlinear analysis of the consecutive phases in the structural behaviour of bridge plate girders with deformations is presented. The analysis concerns all stages of structure loading until failure and especially determination of the ultimate shear load capacity. Verification and validation of the numerical procedures proposed is based on comparison of the calculated results with effects of experimental laboratory shear capacity tests of plate girders carried out at the University of Ljubljana.