Note: This page contains sample records for the topic multi-dimensional scaling analysis from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Development of multi-dimensional body image scale for malaysian female adolescents  

PubMed Central

The present study was conducted to develop a Multi-dimensional Body Image Scale for Malaysian female adolescents. Data were collected among 328 female adolescents from a secondary school in Kuantan district, state of Pahang, Malaysia by using a self-administered questionnaire and anthropometric measurements. The self-administered questionnaire comprised multiple measures of body image, Eating Attitude Test (EAT-26; Garner & Garfinkel, 1979) and Rosenberg Self-esteem Inventory (Rosenberg, 1965). The 152 items from selected multiple measures of body image were examined through factor analysis and for internal consistency. Correlations between Multi-dimensional Body Image Scale and body mass index (BMI), risk of eating disorders and self-esteem were assessed for construct validity. A seven factor model of a 62-item Multi-dimensional Body Image Scale for Malaysian female adolescents with construct validity and good internal consistency was developed. The scale encompasses 1) preoccupation with thinness and dieting behavior, 2) appearance and body satisfaction, 3) body importance, 4) muscle increasing behavior, 5) extreme dieting behavior, 6) appearance importance, and 7) perception of size and shape dimensions. Besides, a multidimensional body image composite score was proposed to screen negative body image risk in female adolescents. The result found body image was correlated with BMI, risk of eating disorders and self-esteem in female adolescents. In short, the present study supports a multi-dimensional concept for body image and provides a new insight into its multi-dimensionality in Malaysian female adolescents with preliminary validity and reliability of the scale. The Multi-dimensional Body Image Scale can be used to identify female adolescents who are potentially at risk of developing body image disturbance through future intervention programs.

Taib, Mohd Nasir Mohd; Shariff, Zalilah Mohd; Khor, Geok Lin

2008-01-01

2

Personality and depressive symptoms: a multi-dimensional analysis  

Microsoft Academic Search

Background: The relationship of temperamental aspects of personality to symptoms of depression in a community-based sample of 804 individuals was examined using a multi-dimensional approach to account for heterogeneity in symptom patterns. Method: The Temperament and Character Inventory (TCI) was used to assess personality and the Center for Epidemiologic Studies Depression scale (CES-D) was used to measure depressive symptoms. Canonical

Richard A. Grucza; Thomas R. Przybeck; Edward L. Spitznagel; C. Robert Cloninger

2003-01-01

3

Coupling visualization and data analysis for knowledge discovery from multi-dimensional scientific data  

PubMed Central

Knowledge discovery from large and complex scientific data is a challenging task. With the ability to measure and simulate more processes at increasingly finer spatial and temporal scales, the growing number of data dimensions and data objects presents tremendous challenges for effective data analysis and data exploration methods and tools. The combination and close integration of methods from scientific visualization, information visualization, automated data analysis, and other enabling technologies —such as efficient data management— supports knowledge discovery from multi-dimensional scientific data. This paper surveys two distinct applications in developmental biology and accelerator physics, illustrating the effectiveness of the described approach.

Rubel, Oliver; Ahern, Sean; Bethel, E. Wes; Biggin, Mark D.; Childs, Hank; Cormier-Michel, Estelle; DePace, Angela; Eisen, Michael B.; Fowlkes, Charless C.; Geddes, Cameron G. R.; Hagen, Hans; Hamann, Bernd; Huang, Min-Yu; Keranen, Soile V. E.; Knowles, David W.; Hendriks, Cris L. Luengo; Malik, Jitendra; Meredith, Jeremy; Messmer, Peter; Prabhat; Ushizima, Daniela; Weber, Gunther H.; Wu, Kesheng

2013-01-01

4

Mobile Self-Localization using MultiDimensional Scaling in Robotic Sensor Networks  

Microsoft Academic Search

In this paper, we define a mobile self-localization (MSL) problem for sparse and\\/or mobile robotic sensor networks, and propose an algorithm, MA-MDS-MAP(P), based on Multi- Dimensional Scaling (MDS) for solving the problem. For sparse robotic sensor networks, all the existing localization alg orithms fail to work properly due to the lack of distance or connec- tivity data to uniquely calculate

Chang-Hua Wu; Weihua Sheng; Ying Zhang

2006-01-01

5

An amino acid map of inter-residue contact energies using metric multi-dimensional scaling  

Microsoft Academic Search

We present an amino map based on their inter-residue contact energies using the Miyazawa–Jernigan matrix. This work is based on the method of metric multi-dimensional scaling (MMDS). The MMDS map shows, among other things, that the MJ contact energies imply the hydrophobic–hydrophilic nature of the amino acid residues. With the help of the map we are able to compare and

Sourav Rakshit; G. K. Ananthasuresh

2008-01-01

6

Comprehensive multi-dimensional liquid chromatographic separation in biomedical and pharmaceutical analysis: a review.  

PubMed

'Multi-dimensional' liquid separations have a history almost as long as chromatography. In multi-dimensional chromatography the sample is subjected to more than one separation mechanism; each mechanism is considered an independent separation dimension. The separations can be carried out either offline via fraction collection, or directly coupled online. Early multi-dimensional separations using combinations of paper chromatography, electrophoresis and gels, in both planar and columnar modes are reviewed. Developments in HPLC have increased the number of measurable analytes in ever more complex matrices, and this has led to the concept of 'global metabolite profiling'. This review focuses on the theory and practice of modern 'comprehensive' multi-dimensional liquid chromatography when applied to biomedical and pharmaceutical analysis. PMID:16779789

Dixon, Steven P; Pitfield, Ian D; Perrett, David

7

MultiDimensional Analysis of International Social Indicators – Education, Economy, Media and Demography  

Microsoft Academic Search

Using multi-dimensional analysis methods, it ispossible to uncover a structure representing therelationship between multiple internationaleducational, social and economic indicators. In thisstudy, we applied Smallest Space Analysis to datacollected by international agencies for 138 countriesand 20 indicators. A preliminary structure was foundand replicated for different data sets. Thisstructural interrelationship shows that these variousindicators are part of a larger field called welfare.This

Erik H. Cohen

2000-01-01

8

A Multi-Dimensional Cognitive Analysis of Undergraduate Physics Students' Understanding of Heat Conduction  

ERIC Educational Resources Information Center

This study proposes a multi-dimensional approach to investigate, represent, and categorize students' in-depth understanding of complex physics concepts. Clinical interviews were conducted with 30 undergraduate physics students to probe their understanding of heat conduction. Based on the data analysis, six aspects of the participants' responses…

Chiou, Guo-Li; Anderson, O. Roger

2010-01-01

9

An amino acid map of inter-residue contact energies using metric multi-dimensional scaling.  

PubMed

We present an amino map based on their inter-residue contact energies using the Miyazawa-Jernigan matrix. This work is based on the method of metric multi-dimensional scaling (MMDS). The MMDS map shows, among other things, that the MJ contact energies imply the hydrophobic-hydrophilic nature of the amino acid residues. With the help of the map we are able to compare and draw inferences from uncorrelated data sets such as BLOSUM and PAM with MJ methods. We also use a hierarchical clustering method on our MMDS distance matrix to group the amino acids and arrive at an optimum number of groups for simplifying the amino acid set. PMID:17981305

Rakshit, Sourav; Ananthasuresh, G K

2007-09-26

10

Discovery of multi-dimensional modules by integrative analysis of cancer genomic data  

PubMed Central

Recent technology has made it possible to simultaneously perform multi-platform genomic profiling (e.g. DNA methylation (DM) and gene expression (GE)) of biological samples, resulting in so-called ‘multi-dimensional genomic data’. Such data provide unique opportunities to study the coordination between regulatory mechanisms on multiple levels. However, integrative analysis of multi-dimensional genomics data for the discovery of combinatorial patterns is currently lacking. Here, we adopt a joint matrix factorization technique to address this challenge. This method projects multiple types of genomic data onto a common coordinate system, in which heterogeneous variables weighted highly in the same projected direction form a multi-dimensional module (md-module). Genomic variables in such modules are characterized by significant correlations and likely functional associations. We applied this method to the DM, GE, and microRNA expression data of 385 ovarian cancer samples from the The Cancer Genome Atlas project. These md-modules revealed perturbed pathways that would have been overlooked with only a single type of data, uncovered associations between different layers of cellular activities and allowed the identification of clinically distinct patient subgroups. Our study provides an useful protocol for uncovering hidden patterns and their biological implications in multi-dimensional ‘omic’ data.

Zhang, Shihua; Liu, Chun-Chi; Li, Wenyuan; Shen, Hui; Laird, Peter W.; Zhou, Xianghong Jasmine

2012-01-01

11

Analysis of multi-dimensional correlation functions in the solar wind  

NASA Astrophysics Data System (ADS)

Single-spacecraft techniques for the determination of multi-dimensional correlation functions in the solar wind were pioneered by [4]. Their production of the so-called ``Maltese Cross'' result shows that magnetic fluctuations near the correlation scale at 1 AU are divided into two components: quasi-parallel and quasi-perpendicular wave vectors. A later ref nement by [2] revealed that the two components were largely separated according to wind speed with the slow wind possessing largely perpendicular wave vectors and the fast wind possessing largely parallel wave vectors. We extend those analyses using four different techniques and compare the results of those techniques. As a demonstration of the techniques, we analyze the geometry of magnetic fluctuations at scales comparable to the correlation length. We then examine the underlying geometry for magnetic, velocity, density and temperature fluctuations. We limit the analysis to fast wind observations and show that the underlying geometry for density and temperature fluctuations is a good match to that of magnetic and velocity fluctuations.

Smith, Charles W.; Vasquez, Bernard J.; Stemkowski, Matthew R.

2013-06-01

12

Method of multi-dimensional moment analysis for the characterization of signal peaks  

SciTech Connect

A method of multi-dimensional moment analysis for the characterization of signal peaks can be used to optimize the operation of an analytical system. With a two-dimensional Peclet analysis, the quality and signal fidelity of peaks in a two-dimensional experimental space can be analyzed and scored. This method is particularly useful in determining optimum operational parameters for an analytical system which requires the automated analysis of large numbers of analyte data peaks. For example, the method can be used to optimize analytical systems including an ion mobility spectrometer that uses a temperature stepped desorption technique for the detection of explosive mixtures.

Pfeifer, Kent B; Yelton, William G; Kerr, Dayle R; Bouchier, Francis A

2012-10-23

13

Overview of Computer-Aided Engineering of Batteries and Introduction to Multi-Scale, Multi-Dimensional Modeling of Li-Ion Batteries (Presentation)  

SciTech Connect

This 2012 Annual Merit Review presentation gives an overview of the Computer-Aided Engineering of Batteries (CAEBAT) project and introduces the Multi-Scale, Multi-Dimensional model for modeling lithium-ion batteries for electric vehicles.

Pesaran, A.; Kim, G. H.; Smith, K.; Santhanagopalan, S.; Lee, K. J.

2012-05-01

14

MD-SeeGH: a platform for integrative analysis of multi-dimensional genomic data  

PubMed Central

Background Recent advances in global genomic profiling methodologies have enabled multi-dimensional characterization of biological systems. Complete analysis of these genomic profiles require an in depth look at parallel profiles of segmental DNA copy number status, DNA methylation state, single nucleotide polymorphisms, as well as gene expression profiles. Due to the differences in data types it is difficult to conduct parallel analysis of multiple datasets from diverse platforms. Results To address this issue, we have developed an integrative genomic analysis platform MD-SeeGH, a software tool that allows users to rapidly and directly analyze genomic datasets spanning multiple genomic experiments. With MD-SeeGH, users have the flexibility to easily update datasets in accordance with new genomic builds, make a quality assessment of data using the filtering features, and identify genetic alterations within single or across multiple experiments. Multiple sample analysis in MD-SeeGH allows users to compare profiles from many experiments alongside tracks containing detailed localized gene information, microRNA, CpG islands, and copy number variations. Conclusion MD-SeeGH is a new platform for the integrative analysis of diverse microarray data, facilitating multiple profile analyses and group comparisons.

Chi, Bryan; deLeeuw, Ronald J; Coe, Bradley P; Ng, Raymond T; MacAulay, Calum; Lam, Wan L

2008-01-01

15

[Improving component analysis ability of the complex mixed solutions by multi-dimensional diffuse transmittance spectrometry].  

PubMed

The multi-dimensional diffuse transmittance spectrums were collected by the traditional near-infrared transmittance method combined with a scanning device, and then used for component analysis of the complex mixed solution. A xenon light, an electric control translation stage and a spectrometer were gathered to set up a device; Intralipid-20%, India-ink and C6H12O6 were used to prepare 225 kinds of complex mixed solutions; the diffuse transmittance spectrums were measured at 20 points off the transmission center distributed from 0-5 mm (interval 0.25 mm); the single and multi-point diffuse transmittance spectrums were analyzed by partial least squares regression for modeling and prediction. The results show that the modeling and prediction accuracy of the concentrations of the intralipid-20% and India-ink increased with the growing of the transmittance points, but the concentration of the C6H12O6 did not increase. It is proved that the spectrums collected by different points can raise the signal to noise radio of the strong absorption and scattering substance, and the signal to noise radio of the weak absorption and scattering substance would be improved by increasing the current system accuracy. PMID:23156780

Xiong, Chan; Lin, Ling; Wang, Meng-jun; Li, Gang; Zhang, Bao-ju

2012-08-01

16

Finite volume scheme for multi-dimensional drift-diffusion equations and convergence analysis  

Microsoft Academic Search

We introduce a nite volume scheme for multi-dimensional drift-diusion equations. Such equations arise from the theory of semiconductors and are composed of two continuity equations coupled with a Poisson equation. In the case that the continuity equations are non degenerate, we prove the convergence of the scheme and then the existence of solutions to the problem. The key point of

Claire Chainais-Hillairet; Jian-Guo Liu; Yue-Jun Peng

2003-01-01

17

Operation and Management Profiles: A Multi-Dimensional Analysis of Successful Urban Educational Programs.  

ERIC Educational Resources Information Center

|This paper presents a theoretical construct that can be used to describe the implementation process of school programs in terms of a multi-dimensional model. Focusing on the research process of the Urban Education Studies, which is devoted to the identification and study of educational programs which are beginning to make inroads for the…

Schwandt, David R.; Cummings, Jay R.

18

Interacting with smart walls: a multi-dimensional analysis of input technologies for augmented environments  

Microsoft Academic Search

This paper reports on a multi-dimensional evaluation of three typical interaction devices for wall-sized displays in augmented environments. Touch, trackpad and gesture input were evaluated regarding a variety of usability dimensions in order to understand the quality profile of each input device. Among the three interaction devices, the touch input showed the highest scores in performance and acceptance as well

Felix Heidrich; Martina Ziefle; Carsten Röcker; Jan Borchers

2011-01-01

19

A New Approach for the Analysis of Complex Multi-Dimensional Data from Instruments which Detect Individual Photons  

NASA Astrophysics Data System (ADS)

We present a full realization of an entirely new approach for the analysis of multi-dimensional data in the form of an finite event list of individual photons, typical of many applications in X-ray and gamma -ray astronomy. The new approach is an inverse Monte Carlo method which starts with a list of raw photons of imperfect information and ends with a finite list of model photons of perfect information. The most significant feature of the new method is that all mathematical steps are carried out without the creation of any spectral or spatial bins of photons. The practical utility of this approach required the invention of a new version of a multi-dimensional Kolmogorov-Smirnov (KS) test.

Jernigan, J. Garrett; Vezie, Michael

20

CTH: A software family for multi-dimensional shock physics analysis  

Microsoft Academic Search

CTH is a family of codes developed at Sandia National Laboratories for modeling complex multi-dimensional, multi-material problems that are characterized by large deformations and\\/or strong shocks. A two-step, second-order accurate Eulerian solution algorithm is used to solve the mass, momentum, and energy conservation equations. CTH includes models for material strength, fracture, porous materials, and high explosive detonation and initiation. Viscoplastic

E. S. Jr. Hertel; R. L. Bell; M. G. Elrick; A. V. Farnsworth; G. I. Kerley; J. M. McGlaun; S. V. Petney; S. A. Silling; P. A. Taylor; L. Yarrington

1992-01-01

21

Measuring the Effectiveness of Advertising in a Positioning Context with Multi Dimensional Scaling Techniques.  

National Technical Information Service (NTIS)

Measuring the effectiveness of advertising in the context of positioning can easily be accomplished by multidimensional scaling (MDS)-procedures and the Index of Effectiveness (IE). However, many problems have to be eliminated. Most problems arise from th...

M. Versteijne

1988-01-01

22

Psychophysical similarity measure based on multi-dimensional scaling for retrieval of similar images of breast masses on mammograms  

NASA Astrophysics Data System (ADS)

For retrieving reference images which may be useful to radiologists in their diagnosis, it is necessary to determine a reliable similarity measure which would agree with radiologists' subjective impression. In this study, we propose a new similarity measure for retrieval of similar images, which may assist radiologists in the distinction between benign and malignant masses on mammograms, and investigated its usefulness. In our previous study, to take into account the subjective impression, the psychophysical similarity measure was determined by use of an artificial neural network (ANN), which was employed to learn the relationship between radiologists' subjective similarity ratings and image features. In this study, we propose a psychophysical similarity measure based on multi-dimensional scaling (MDS) in order to improve the accuracy in retrieval of similar images. Twenty-seven images of masses, 3 each from 9 different pathologic groups, were selected, and the subjective similarity ratings for all possible 351 pairs were determined by 8 expert physicians. MDS was applied using the average subjective ratings, and the relationship between each output axis and image features was modeled by the ANN. The MDS-based psychophysical measures were determined by the distance in the modeled space. With a leave-one-out test method, the conventional psychophysical similarity measure was moderately correlated with subjective similarity ratings (r=0.68), whereas the psychophysical measure based on MDS was highly correlated (r=0.81). The result indicates that a psychophysical similarity measure based on MDS would be useful in the retrieval of similar images.

Nishimura, Kohei; Muramatsu, Chisako; Oiwa, Mikinao; Shiraiwa, Misaki; Endo, Tokiko; Doi, Kunio; Fujita, Hiroshi

2013-02-01

23

Relationships between organizations and publics: Development of a multi-dimensional organization-public relationship scale  

Microsoft Academic Search

Public relations has long struggled to develop an identity in both scholarship and practice. An increasing number of scholars are adopting the perspective that public relations should be viewed as the management of a relationship between organizations and publics. The current investigation was an attempt to design a multiple-item, multiple-dimension organization-public relationship scale. Results of this investigation show that organizations

Stephen D. Bruning; John A. Ledingham

1999-01-01

24

Potential of SAR for monitoring transportation infrastructures: an analysis with the multi-dimensional imaging technique  

NASA Astrophysics Data System (ADS)

Differential interferometric synthetic aperture radar (SAR) has proven to be effective for accurate localization and monitoring of the displacement of ground targets. The high accuracy and spatial density of the measurements make this technique cost effective compared to the classical geodetic techniques typically used in the risk monitoring context. Ground infrastructure monitoring is typically carried out with in situ sensors. The new generation of high-resolution SAR sensors, however, allows one to acquire data sets with a spatial resolution reaching metric/submetric values. Here we investigate the application of a multi-dimensional SAR imaging technique, which is an extension of classical differential interferometric techniques, to very high resolution TerraSAR-X data in order to demonstrate the potential of this technology for monitoring of transportation infrastructures.

Fornaro, G.; Reale, D.; Verde, S.

2012-08-01

25

CTH: A software family for multi-dimensional shock physics analysis  

SciTech Connect

CTH is a family of codes developed at Sandia National Laboratories for modeling complex multi-dimensional, multi-material problems that are characterized by large deformations and/or strong shocks. A two-step, second-order accurate Eulerian solution algorithm is used to solve the mass, momentum, and energy conservation equations. CTH includes models for material strength, fracture, porous materials, and high explosive detonation and initiation. Viscoplastic or rate-dependent models of material strength have been added recently. The formulations of Johnson-Cook, Zerilli-Armstrong, and Steinberg-Guinan-Lund are standard options within CTH. These models rely on using an internal state variable to account for the history dependence of material response. The implementation of internal state variable models will be discussed and several sample calculations will be presented. Comparison with experimental data will be made among the various material strength models. The advancements made in modelling material response have significantly improved the ability of CTH to model complex large-deformation, plastic-flow dominated phenomena. Detonation of energetic material under shock loading conditions has been of great interest. A recently developed model of reactive burn for high explosives (HE) has been added to CTH. This model along with newly developed tabular equations-of-state for the HE reaction by-products has been compared to one- and two-dimensional explosive detonation experiments. These comparisons indicate excellent agreement of CTH predictions with experimental results. The new reactive burn model coupled with the advances in equation-of-state modeling make it possible to predict multi-dimensional burn phenomena without modifying the model parameters for different dimensionality. Examples of the features of CTH will be given. The emphasis in simulations shown will be in comparison with well characterized experiments covering key phenomena of shock physics.

Hertel, E.S. Jr.; Bell, R.L.; Elrick, M.G.; Farnsworth, A.V.; Kerley, G.I.; McGlaun, J.M.; Petney, S.V.; Silling, S.A.; Taylor, P.A.; Yarrington, L.

1992-12-31

26

Pedagogic discourse in introductory classes: Multi-dimensional analysis of textbooks and lectures in biology and macroeconomics  

NASA Astrophysics Data System (ADS)

The broad goal of this study is to represent the linguistic variation of textbooks and lectures, the primary input for student learning---and sometimes the sole input in the large introductory classes which characterize General Education at many state universities. Computer techniques are used to analyze a corpus of textbooks and lectures from first-year university classes in macroeconomics and biology. These spoken and written variants are compared to each other as well as to benchmark texts from other multi-dimensional studies in order to examine their patterns, relations, and functions. A corpus consisting of 147,000 words was created from macroeconomics and biology lectures at a medium-large state university and from a set of nationally "best-selling" textbooks used in these same introductory survey courses. The corpus was analyzed using multi-dimensional methodology (Biber, 1988). The analysis consists of both empirical and qualitative phases. Quantitative analyses are undertaken on the linguistic features, their patterns of co-occurrence, and on the contextual elements of classrooms and textbooks. The contextual analysis is used to functionally interpret the statistical patterns of co-occurrence along five dimensions of textual variation, demonstrating patterns of difference and similarity with reference to text excerpts. Results of the analysis suggest that academic discourse is far from monolithic. Pedagogic discourse in introductory classes varies by modality and discipline, but not always in the directions expected. In the present study the most abstract texts were biology lectures---more abstract than written genres of academic prose and more abstract than introductory textbooks. Academic lectures in both disciplines, monologues which carry a heavy informational load, were extremely interactive, more like conversation than academic prose. A third finding suggests that introductory survey textbooks differ from those used in upper division classes by being relatively less marked for information density, abstraction, and non-overt argumentation. In addition to the findings mentioned here, numerous other relationships among the texts exhibit complex patterns of variation related to a number of situational variables. Pedagogical implications are discussed in relation to General Education courses, differing student populations, and the reading and listening demands which students encounter in large introductory classes in the university.

Carkin, Susan

27

Systematic analysis of choline-containing phospholipids using multi-dimensional mass spectrometry-based shotgun lipidomics?  

PubMed Central

Herein, a systematic study on the identification and quantitation of choline-containing phospholipid molecular species, including choline glycerophospholipid (PC), lysoPC, and sphingomyelin (SM), is described using multi-dimensional mass spectrometry-based shotgun lipidomics after intrasource separation (MDMS-SL). Current methods for analysis of choline-containing lipids were improved through multiple modifications leading to: (1) identification of constituents present in the PC and SM classes, subclasses of PC, and individual molecular species using MDMS-SL analysis in the positive-ion mode; (2) identification of the fatty acyl constituents and their regiospecificity in diacyl PC molecular species through the neutral loss of trimethylamine plus fatty acids; (3) direct identification of the alkenyl chains of plasmenylcholine species using precursor ion scans of the fragment ions carrying the alkenyl chains; (4) elimination of the effects of polyunsaturation on the quantitation of PC species by multiple ratiometric comparisons; (5) accurate identification and quantitation of lysoPC molecular species including regioisomers by diagnostic fragment ions; and (6) accurate identification and quantitation of SM molecular species by neutral loss scans of phosphocholine plus methyl aldehyde which is specific to SM molecular species. With these enhancements, the application of MDMS-SL for the analyses of choline-containing phospholipid molecular species in biomedical research has been extended to a much larger number of molecular species with greater quantitative accuracy and an increased depth of structural information.

Yang, Kui; Zhao, Zhongdan; Gross, Richard W.; Han, Xianlin

2010-01-01

28

Microscale isoelectric fractionation using immobilized pH-specific membranes for multi-dimensional analysis.  

SciTech Connect

We report on advancements of our microscale isoelectric fractionation ({mu}IEFr) methodology for fast on-chip separation and concentration of proteins based on their isoelectric points (pI). We establish that proteins can be fractionated depending on posttranslational modifications into different pH specific bins, from where they can be efficiently transferred to downstream membranes for additional processing and analysis. This technology can enable on-chip multidimensional glycoproteomics analysis, as a new approach to expedite biomarker identification and verification.

Mai, Junyu; Sommer, Gregory Jon; Hatch, Anson V.

2010-10-01

29

Frequency analysis for multi-dimensional systems. Global dynamics and diffusion  

Microsoft Academic Search

Frequency analysis is a new method for analyzing the stability of orbits in a conservative dynamical system. It was first devised in order to study the stability of the solar system [J. Laskar, Icarus 88 (1990) 266-291] and then applied to the 2D standard mapping [Laskar et al., Physica D 56 (1992) 253-269]. It is a powerful method for analyzing

Jacques Laskar

1993-01-01

30

Multi-dimensional analysis of the chemical and physical properties of spiral galaxies  

NASA Astrophysics Data System (ADS)

In this thesis, wide-field 2D spectroscopy is employed in order to characterise the nebular properties of late-type field galaxies. The observations performed for this dissertation represent the first endeavour to obtain full 2D coverage of the disks of a sample of nearby spiral galaxies, by the application of the Integral Field Spectroscopy (IFS) technique, under the PPAK IFS Nearby Galaxies Survey: PINGS. A self-consistent methodology is defined in terms of observation, data reduction and analysis techniques for this and upcoming IFS surveys, as well as providing a whole new set of IFS visualization and analysis software made available for the public domain (PINGSoft). The scientific analysis comprises the study of the integrated properties of the ionized gas and a detailed 2D study from the emission line spectra of four selected galaxies. Evidence is found suggesting that measurements of emission lines of classical HII regions are not only aperture, but spatial dependent, and therefore, the derived physical parameters and metallicity content may significantly depend on the morphology of the region, on the extraction aperture and on the signal-to-noise of the observed spectrum. Furthermore, observational evidence of non-linear multi-modal abundance gradients in normal spiral galaxies is found, consistent with a flattening in the innermost and outermost parts of the galactic discs, with important implications in terms of the chemical evolution of galaxies.

Rosales-Ortega, F. F.

2010-06-01

31

Multi-dimensional Co-separation Analysis Reveals Protein-Protein Interactions Defining Plasma Lipoprotein Subspecies.  

PubMed

The distribution of circulating lipoprotein particles affects the risk for cardiovascular disease (CVD) in humans. Lipoproteins are historically defined by their density, with low-density lipoproteins positively and high-density lipoproteins (HDLs) negatively associated with CVD risk in large populations. However, these broad definitions tend to obscure the remarkable heterogeneity within each class. Evidence indicates that each class is composed of physically (size, density, charge) and compositionally (protein and lipid) distinct subclasses exhibiting unique functionalities and differing effects on disease. HDLs in particular contain upward of 85 proteins of widely varying function that are differentially distributed across a broad range of particle diameters. We hypothesized that the plasma lipoproteins, particularly HDL, represent a continuum of phospholipid platforms that facilitate specific protein-protein interactions. To test this idea, we separated normal human plasma using three techniques that exploit different lipoprotein physicochemical properties (gel filtration chromatography, ionic exchange chromatography, and preparative isoelectric focusing). We then tracked the co-separation of 76 lipid-associated proteins via mass spectrometry and applied a summed correlation analysis to identify protein pairs that may co-reside on individual lipoproteins. The analysis produced 2701 pairing scores, with the top hits representing previously known protein-protein interactions as well as numerous unknown pairings. A network analysis revealed clusters of proteins with related functions, particularly lipid transport and complement regulation. The specific co-separation of protein pairs or clusters suggests the existence of stable lipoprotein subspecies that may carry out distinct functions. Further characterization of the composition and function of these subspecies may point to better targeted therapeutics aimed at CVD or other diseases. PMID:23882025

Gordon, Scott M; Deng, Jingyuan; Tomann, Alex B; Shah, Amy S; Lu, L Jason; Davidson, W Sean

2013-07-23

32

Analysis of the urine proteome via a combination of multi-dimensional approaches.  

PubMed

Urine is a biological fluid that is non-invasively and easily harvested, and exhibits high stability from the proteomics point of view. At the downside, the overall low protein content of urine as well as the presence of low- and high-abundance proteins underscores the need for protein enrichment. As a continuation of previous efforts towards the comprehensive characterization of the urine proteome, the current study targeted the mining of urine proteins through the combined application of different protein separation methodologies, specifically, liquid chromatography and preparative electrophoresis along with 1D gel electrophoresis and protein identification by mass spectrometry. In order to enhance comparison and integration of different experimental data sets, the "standard" urine sample developed within the European Kidney and Urine Proteomics (EuroKUP) COST Action, was employed. As a contribution to the existing knowledge, we focused on maintaining and providing information about experimental mass of the identified proteins as well as information pertaining to their relative abundance--as allowed by technical limitations--thus providing an initial view of different isoforms representation and facilitating their future characterization. The difficulties in comparing proteome mining data sets become once more evident, underscoring the need for adopting standardized ways for data reporting as well as for potential new approaches for data analysis involving a thorough investigation of received information at the peptide level. PMID:22140069

Zerefos, Panagiotis G; Aivaliotis, Michalis; Baumann, Marc; Vlahou, Antonia

2012-01-18

33

Impurity analysis of pure aldrin using heart-cut multi-dimensional gas chromatography-mass spectrometry.  

PubMed

Identification and quantification of related-structure impurity is a research focus in the purity assessment of organic compounds. Determination of the purity value and uncertainty assessment are also important in the metrological research. A method for the determination of related-structure impurity in pure aldrin sample has been developed by using heart-cut multi-dimensional gas chromatography-mass spectrometry (MDGC/MS). Compared to the traditional one-dimensional (1-D) GC system, the two separated columns in the MDGC/MS system can effectively reduce co-elution, enhance separation capability, and thus improve detectability of the trace-level impurities. In addition, MDGC/MS system was simultaneously equipped with flame ionization detector (FID) or electron capture detector (ECD) in the first GC unit and mass spectrometry (MS) detector in the second GC unit. Therefore, accurate quantitative results of the trace-level impurities can be easily achieved by isolation of principal component to the second dimension column using "heart-cut" process. The mass fraction of related-structure impurities in aldrin samples obtained using MDGC/MS system ranged from 6.8×10?³ mg g?¹ to 26.47 mg g?¹ with five orders of magnitude, which is hard to be realized by mean of the 1-D GC. Excellent linearity with correlation coefficients of above 0.999 was achieved for each impurity analysis over a wide range of concentrations. Limits of quantification (LOQ) varied from 250 ng g?¹ to 330 ng g?¹ for FID, and from 1.0 ng g?¹ to 2.0 ng g?¹ detected by ECD. The combined standard uncertainty (u(c)) was lower than 0.37 mg g?¹ and 0.040 mg g?¹ detected using FID and ECD, respectively. Therefore, performance characterization of MDGC/MS used in the study is fit for quantification analysis of trace-level impurity. These results demonstrate that the MDGC/MS is extremely suitable for the purity assessment of organic compounds with medium structural complexity and low polarity. PMID:23332869

Li, Xiaomin; Dai, Xinhua; Yin, Xiong; Li, Ming; Zhao, Yingchen; Zhou, Jian; Huang, Ting; Li, Hongmei

2013-01-03

34

Experimental validation studies on a multi-dimensional and multi-scale population balance model of batch granulation  

Microsoft Academic Search

In this study, a dynamic model is presented for the granulation process, employing a three-dimensional population balance framework. As a first attempt to account for the multi-scale character of the process, the nucleation and aggregation kernels used in the population balance model are derived using mechanistic representations of the underlying particle physics such as wetting kinetics and energy dissipation effects.

Jonathan M.-H. Poon; Rohit Ramachandran; Constantijn F. W. Sanders; Thomas Glaser; Charles D. Immanuel; Francis J. Doyle III; James D. Litster; Frantisek Stepanek; Fu-Yang Wang; Ian T. Cameron

2009-01-01

35

The Kids' Empathic Development Scale (KEDS): a multi-dimensional measure of empathy in primary school-aged children.  

PubMed

Empathy is an essential building block for successful interpersonal relationships. Atypical empathic development is implicated in a range of developmental psychopathologies. However, assessment of empathy in children is constrained by a lack of suitable measurement instruments. This article outlines the development of the Kids' Empathic Development Scale (KEDS) designed to assess some of the core affective, cognitive and behavioural components of empathy concurrently. The KEDS assesses responses to picture scenarios depicting a range of individual and interpersonal situations differing in social complexity. Results from 220 children indicate the KEDS measures three related but distinct aspects of empathy that are also related to existing measures of empathy and cognitive development. Scores on the KEDS show age and some gender-related differences in the expected direction. PMID:23659893

Reid, Corinne; Davis, Helen; Horlin, Chiara; Anderson, Mike; Baughman, Natalie; Campbell, Catherine

2012-11-02

36

Multi-dimensional correlations for gene coexpression and application to the large-scale data of Arabidopsis  

PubMed Central

Background: Recent improvements in DNA microarray techniques have made a large variety of gene expression data available in public databases. This data can be used to evaluate the strength of gene coexpression by calculating the correlation of expression patterns among different genes between many experiments. However, gene expression levels differ significantly across various tissues in higher organisms, as well as in different cellular location in eukaryotes in different cell state. Thus the usual correlation measure can only evaluate the difference of tissues or cellular localizations, and cannot adequately elucidate the functional relationship from the coexpression of genes. Method: We propose a new measure of coexpression by expanding the generally used correlation into a multidimensional one. We used principal component analyses to identify the major factors of gene expression correlation, and then re-calculate the correlation by subtracting the major components in order to remove biases cased by a few experiments. The repeated subtractions of the major components yielded a set of correlation values for each pair of genes. We observed the correlation changes when the first ten principal components were subtracted step-by-step in large-scale Arabidopsis expression data. Results: We found two extreme patterns of correlation changes, corresponding to stable and fragile coexpression. Our new indexes provided a good means to determine the functional relationships of the genes, by examining a few examples, and higher performance of Gene Ontology term prediction by using the support vector machine and the multidimensional correlation. Availability: The results are available from the expression detail pages in ATTED-II (http://atted.jp). Contact: kinosita@hgc.jp Supplementary information: Supplementary data are available at Bioinformatics online.

Kinoshita, Kengo; Obayashi, Takeshi

2009-01-01

37

Data Mining in Multi-Dimensional Functional Data for Manufacturing Fault Diagnosis  

SciTech Connect

Multi-dimensional functional data, such as time series data and images from manufacturing processes, have been used for fault detection and quality improvement in many engineering applications such as automobile manufacturing, semiconductor manufacturing, and nano-machining systems. Extracting interesting and useful features from multi-dimensional functional data for manufacturing fault diagnosis is more difficult than extracting the corresponding patterns from traditional numeric and categorical data due to the complexity of functional data types, high correlation, and nonstationary nature of the data. This chapter discusses accomplishments and research issues of multi-dimensional functional data mining in the following areas: dimensionality reduction for functional data, multi-scale fault diagnosis, misalignment prediction of rotating machinery, and agricultural product inspection based on hyperspectral image analysis.

Jeong, Myong K [ORNL; Kong, Seong G [ORNL; Omitaomu, Olufemi A [ORNL

2008-09-01

38

Collaborative Visualization and Analysis of Multi-dimensional, Time-dependent and Distributed Data in the Geosciences Using the Unidata Integrated Data Viewer  

NASA Astrophysics Data System (ADS)

Over the last five years, UNIDATA has developed an extensible and flexible software framework for analyzing and visualizing geoscience data and models. The Integrated Data Viewer (IDV), initially developed for visualization and analysis of atmospheric data, has broad interdisciplinary application across the geosciences including atmospheric, ocean, and most recently, earth sciences. As part of the NSF-funded GEON Information Technology Research project, UNAVCO has enhanced the IDV to display earthquakes, GPS velocity vectors, and plate boundary strain rates. These and other geophysical parameters can be viewed simultaneously with three-dimensional seismic tomography and mantle geodynamic model results. Disparate data sets of different formats, variables, geographical projections and scales can automatically be displayed in a common projection. The IDV is efficient and fully interactive allowing the user to create and vary 2D and 3D displays with contour plots, vertical and horizontal cross-sections, plan views, 3D isosurfaces, vector plots and streamlines, as well as point data symbols or numeric values. Data probes (values and graphs) can be used to explore the details of the data and models. The IDV is a freely available Java application using Java3D and VisAD and runs on most computers. UNIDATA provides easy-to-follow instructions for download, installation and operation of the IDV. The IDV primarily uses netCDF, a self-describing binary file format, to store multi-dimensional data, related metadata, and source information. The IDV is designed to work with OPeNDAP-equipped data servers that provide real-time observations and numerical models from distributed locations. Users can capture and share screens and animations, or exchange XML "bundles" that contain the state of the visualization and embedded links to remote data files. A real-time collaborative feature allows groups of users to remotely link IDV sessions via the Internet and simultaneously view and control the visualization. A Jython-based formulation facility allows computations on disparate data sets using simple formulas. Although the IDV is an advanced tool for research, its flexible architecture has also been exploited for educational purposes with the Virtual Geophysical Exploration Environment (VGEE) development. The VGEE demonstration added physical concept models to the IDV and curricula for atmospheric science education intended for the high school to graduate student levels.

Meertens, C. M.; Murray, D.; McWhirter, J.

2004-12-01

39

Enantiomeric analysis of anatabine, nornicotine and anabasine in commercial tobacco by multi-dimensional gas chromatography and mass spectrometry.  

PubMed

A fully automated multi-dimensional gas chromatography (MDGC) system with a megabore precolumn and cyclodextrin-based analytical column was developed to analyze the enantiomeric compositions of anatabine, nornicotine and anabasine in commercial tobacco. The enantiomer abundances of anatabine and nornicotine varied among different tobacco. S-(-)-anatabine, as a proportion of total anatabine, was 86.6% for flue-cured, 86.0% for burley and 77.5% for oriental tobacco. S-(-)-nornicotine, as a proportion of total nornicotine, was 90.8% in oriental tobacco and higher than in burley (69.4%) and flue-cured (58.7%) tobacco. S-(-)-anabasine, as a proportion of total anabasine, was relatively constant for flue-cured (60.1%), burley (65.1%) and oriental (61.7%) tobacco. A simple solvent extraction with dichloromethane followed by derivatisation with trifluoroacetic anhydride gave relative standard deviations of less than 1.5% for the determination of the S-(-)-isomers of all three alkaloids. The study also indicated that, a higher proportion of S-(-)-nornicotine is related to the more active nicotine demethylation in the leaf. PMID:18342587

Liu, Baizhan; Chen, Chaoying; Wu, Da; Su, Qingde

2008-01-31

40

Multi Dimensional Phase Only Filter  

SciTech Connect

Today's sensor networks provide a wide variety of application domain for high-speed pattern classification systems. Such high-speed systems can be achieved by the use of optical implementation of specialized POF correlator. In this research we discuss the modeling and simulation of the phase only filter (POF) in the task of pattern classification of multi-dimensional data.

Gudmundsson, K; Awwal, A

2004-07-13

41

A multi-dimensional analysis of the upper Rio Grande-San Luis Valley social-ecological system  

NASA Astrophysics Data System (ADS)

The Upper Rio Grande (URG), located in the San Luis Valley (SLV) of southern Colorado, is the primary contributor to streamflow to the Rio Grande Basin, upstream of the confluence of the Rio Conchos at Presidio, TX. The URG-SLV includes a complex irrigation-dependent agricultural social-ecological system (SES), which began development in 1852, and today generates more than 30% of the SLV revenue. The diversions of Rio Grande water for irrigation in the SLV have had a disproportionate impact on the downstream portion of the river. These diversions caused the flow to cease at Ciudad Juarez, Mexico in the late 1880s, creating international conflict. Similarly, low flows in New Mexico and Texas led to interstate conflict. Understanding changes in the URG-SLV that led to this event and the interactions among various drivers of change in the URG-SLV is a difficult task. One reason is that complex social-ecological systems are adaptive, contain feedbacks, emergent properties, cross-scale linkages, large-scale dynamics and non-linearities. Further, most analyses of SES to date have been qualitative, utilizing conceptual models to understand driver interactions. This study utilizes both qualitative and quantitative techniques to develop an innovative approach for analyzing driver interactions in the URG-SLV. Five drivers were identified for the URG-SLV social-ecological system: water (streamflow), water rights, climate, agriculture, and internal and external water policy. The drivers contained several longitudes (data aspect) relevant to the system, except water policy, for which only discreet events were present. Change point and statistical analyses were applied to the longitudes to identify quantifiable changes, to allow detection of cross-scale linkages between drivers, and presence of feedback cycles. Agricultural was identified as the driver signal. Change points for agricultural expansion defined four distinct periods: 1852--1923, 1924--1948, 1949--1978 and 1979--2007. Changes in streamflow, water allocations and water policy were observed in all agriculture periods. Cross-scale linkages were also evident between climate and streamflow; policy and water rights; and agriculture, groundwater pumping and streamflow.

Mix, Ken

42

High-School Exit Examinations and the Schooling Decisions of Teenagers: A Multi-Dimensional Regression-Discontinuity Analysis. NBER Working Paper No. 17112  

ERIC Educational Resources Information Center

We ask whether failing one or more of the state-mandated high-school exit examinations affects whether students graduate from high school. Using a new multi-dimensional regression-discontinuity approach, we examine simultaneously scores on mathematics and English language arts tests. Barely passing both examinations, as opposed to failing them,…

Papay, John P.; Willett, John B.; Murnane, Richard J.

2011-01-01

43

An evaluation of a multi-dimensional FCT algorithm with some higher-order upwind schemes  

Microsoft Academic Search

Small-scale ripples appearing in solutions of two test problems with the multi-dimensional flux-corrected transport (FCT) algorithm of Zalesak (Z-FCT) [1] are investigated. An alternative derivation of the Z-FCT flux limiter is presented directly from a multi-dimensional discrete equation. Three second-order schemes are tested.

Yuguo Li; Murray Rudman

1995-01-01

44

New Bounds for Multi-Dimensional Packing.  

National Technical Information Service (NTIS)

New upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box...

R. Van Stee S. Seiden

2001-01-01

45

Recent development of multi-dimensional chromatography strategies in proteome research  

Microsoft Academic Search

As a complementary approach to two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), multi-dimensional chromatography separation methods have been widely applied in all kinds of biological sample investigations. Multi-dimensional liquid chromatography (MDLC) coupled with bio-mass spectrometry (MS) is playing important roles in proteome research due to its high speed, high resolution and high sensitivity. Proteome analysis strategies mainly include bottom-up and top-down approaches

Jia Tang; Mingxia Gao; Chunhui Deng; Xiangming Zhang

2008-01-01

46

Multi-dimensional signal processing research program  

NASA Astrophysics Data System (ADS)

This Semiannual Technical Summary covers the period 1 October 1982 through 31 March 1983. It describes the significant results of the Lincoln Laboratory Multi-Dimensional Signal Processing Research Program, sponsored by the Rome Air Development Center, in the areas of multiprocessor architectures for image processing and algorithms for object detection and region classification in aerial reconnaissance imagery.

Dudgeon, D. E.

1983-03-01

47

Multi-dimensional signal procesing research program  

NASA Astrophysics Data System (ADS)

This semiannual technical summary covers the period 1 April through 30 September 1982. It describes the significant results of the Lincoln Laboratory Multi-Dimensional Signal Processing Research Program sponsored by the Rome Air Development Center, in the areas of image segmentation, classification, target detection, and adaptive contrast enhancement.

Dudgeon, D. E.

1982-09-01

48

Multi Dimensional and Flexible Model for Databases  

Microsoft Academic Search

\\u000a This article proposes multi dimensional model for databases suitable for both transmissions of data over the networks and\\u000a data storage in IT\\/IS systems. In this model there is no need to predict the complete structure of the databases. The structure\\u000a of these databases can be changeable in any time as needed. In the proposed model, the structure of a record

Morteza Sargolzaei Javan; Farahnaz Mohanna; Sepide Aghajani

2008-01-01

49

Extended Darknet: Multi-Dimensional Internet Threat Monitoring System  

NASA Astrophysics Data System (ADS)

Internet threats caused by botnets/worms are one of the most important security issues to be addressed. Darknet, also called a dark IP address space, is one of the best solutions for monitoring anomalous packets sent by malicious software. However, since darknet is deployed only on an inactive IP address space, it is an inefficient way for monitoring a working network that has a considerable number of active IP addresses. The present paper addresses this problem. We propose a scalable, light-weight malicious packet monitoring system based on a multi-dimensional IP/port analysis. Our system significantly extends the monitoring scope of darknet. In order to extend the capacity of darknet, our approach leverages the active IP address space without affecting legitimate traffic. Multi-dimensional monitoring enables the monitoring of TCP ports with firewalls enabled on each of the IP addresses. We focus on delays of TCP syn/ack responses in the traffic. We locate syn/ack delayed packets and forward them to sensors or honeypots for further analysis. We also propose a policy-based flow classification and forwarding mechanism and develop a prototype of a monitoring system that implements our proposed architecture. We deploy our system on a campus network and perform several experiments for the evaluation of our system. We verify that our system can cover 89% of the IP addresses while darknet-based monitoring only covers 46%. On our campus network, our system monitors twice as many IP addresses as darknet.

Shimoda, Akihiro; Mori, Tatsuya; Goto, Shigeki

50

Procedural shape generation for multi-dimensional data visualization  

Microsoft Academic Search

Visualization of multi-dimensional data is a challenging task. The goal is not the display of multiple data dimensions, but user comprehension of the multi-dimensional data. This paper explores several techniques for perceptually motivated procedural generation of shapes to increase the comprehension of multi-dimensional data. Our glyph-based system allows the visualization of both regular and irregular grids of volumetric data. A

David S. Ebert; Randall M. Rohrer; Christopher D. Shaw; Pradyut Panda; James M. Kukla; D. Aaron Roberts

2000-01-01

51

Continuous Energy, Multi-Dimensional Transport Calculations for Problem Dependent Resonance Self-Shielding  

SciTech Connect

The overall objective of the work here has been to eliminate the approximations used in current resonance treatments by developing continuous energy multi-dimensional transport calculations for problem dependent self-shielding calculations. The work here builds on the existing resonance treatment capabilities in the ORNL SCALE code system.

T. Downar

2009-03-31

52

Multi-Dimensional Cosmology and Dsr-Gup  

NASA Astrophysics Data System (ADS)

A multi-dimensional cosmology with FRW type metric having four-dimensional spacetime and d-dimensional Ricci-flat internal space is considered with a higher-dimensional cosmological constant. The classical cosmology in commutative and Doubly Special Relativity-Generalized Uncertainty Principle (DSR-GUP) contexts is studied and the corresponding exact solutions for negative and positive cosmological constants are obtained. In the positive cosmological constant case, it is shown that unlike the commutative as well as GUP cases, in DSR-GUP case both scale factors of internal and external spaces after accelerating phase will inevitably experience decelerating phase leading simultaneously to a big crunch. This demarcation from GUP originates from the difference between the GUP and DSR-GUP algebras. The important result is that unlike GUP which results in eternal acceleration, DSR-GUP at first generates acceleration but prevents the eternal acceleration at late-times and turns it into deceleration.

Zeynali, K.; Darabi, F.; Motavalli, H.

2013-04-01

53

Methodological Issues in Developing a Multi-Dimensional Coding Procedure for Small-Group Chat Communication  

ERIC Educational Resources Information Center

In CSCL research, collaboration through chat has primarily been studied in dyadic settings. This article discusses three issues that emerged during the development of a multi-dimensional coding procedure for small-group chat communication: (a) the unit of analysis and unit fragmentation, (b) the reconstruction of the response structure and (c)…

Strijbos, Jan-Willem; Stahl, Gerry

2007-01-01

54

A multi?dimensional model of reflective learning for professional development  

Microsoft Academic Search

This study is set in the context of a postgraduate course for pharmacists where the participants were exposed to a systematic reflective learning strategy facilitated by a structured, written Reflective Portfolio. Data were generated using focus groups and individual interviews. An inductive approach to data analysis resulted in a Multi?dimensional Model of Reflection that has not previously been presented elsewhere.

Patricia E. Black; David Plowright

2010-01-01

55

Generalizations of suffix arrays to multi-dimensional matrices  

Microsoft Academic Search

We propose multi-dimensional index data structures that generalize suffix arrays to square matrices and cubic matrices. Giancarlo proposed a two-dimensional index data structure, the Lsuffix tree, that generalizes suffix trees to square matrices. However, the construction algorithm for Lsuffix trees maintains complicated data structures and uses a large amount of space. We present simple construction algorithms for multi-dimensional suffix arrays

Dong Kyue Kim; Yoo Ah Kim

2003-01-01

56

The internationalization of SMEs: developing and testing a multi-dimensional measure on Slovenian firms  

Microsoft Academic Search

The internationalization of small and medium-sized enterprises (SMEs) is explored by focusing on a clarification of the internationalization construct. A set of hypotheses is conceptually developed, including the main dimensions of internationalization (operation mode, market, product, time and performance). The proposed multi-dimensional internationalization construct is empirically tested.Questionnaire data were collected from a sample of 161 Slovenian SMEs. Scales were tested

Mitja Ruzzier; Bostjan Antoncic; Robert D. Hisrich

2007-01-01

57

Development and validation of a multi- dimensional instrument for assessing outeome of treatment among opiate users: the Opiate Treatment Index  

Microsoft Academic Search

This article presents a new instrument with which to assess the effects of opiate treatment. The Opiate Treatment Index (OTI) is multi-dimensional in structure, with scales measuring six independently measured outcome domains: drug use; HIV risk-taking behaviour; social functioning; criminality; health; and psychological adjustment. Psychometric properties of the Index are excellent, suggesting that the OTI is a relatively quick, efficient

SHANE DARKE; ALEX WODAK; NICK HEATHER; JEFF WARD

58

Improving the classification accuracy in electronic noses using multi-dimensional combining (MDC)  

Microsoft Academic Search

Traditional pattern recognition (PARC) methods, used in electronic noses (e-noses) are either parametric (such as k-nearest neighbors, KNN, and linear discriminant analysis, LDA) or non-parametric (such as artificial neural network and fuzzy logic). Multi-dimensional combining (MDC) is proposed to combine the classification outputs of individual classifiers into a more robust and accurate one. Two implementations are proposed to find the

Hong Chen; R. A. Goubran; Tofy Mussivand

2004-01-01

59

High-value energy storage for the grid: a multi-dimensional look  

SciTech Connect

The conceptual attractiveness of energy storage in the electrical power grid has grown in recent years with Smart Grid initiatives. But cost is a problem, interwoven with the complexity of quantifying the benefits of energy storage. This analysis builds toward a multi-dimensional picture of storage that is offered as a step toward identifying and removing the gaps and ''friction'' that permeate the delivery chain from research laboratory to grid deployment. (author)

Culver, Walter J.

2010-12-15

60

Multi-dimensional Quasar Selection from Optical, Near-IR, and Astrometric Data  

NASA Astrophysics Data System (ADS)

In the future, quasar selection will be much more multi-dimensional than it is today. Algorithms will go far beyond simple optical color or variability selection. Instead quasar selection will rely on simultaneous usage of multi-wavelength photometry, variability, and even astrometry. The SDSS Southern Equatorial Stripe (aka Stripe 82) is an ideal proving ground for such future algorithms. Herein we take the first steps in true multi-dimensional analysis by describing an algorithm that uses multi-epoch optical data from the SDSS, near-IR data from UKIDSS, and astrometric information to select quasars (and determine photometric redshifts). We present the resulting catalog and compare our results to existing spectroscopic surveys.

Richards, Gordon T.; Mehta, S. S.; Peters, C. M.; Myers, A. D.; Ross, N. P.

2012-01-01

61

Multi-dimensional discovery of biomarker and phenotype complexes  

PubMed Central

Background Given the rapid growth of translational research and personalized healthcare paradigms, the ability to relate and reason upon networks of bio-molecular and phenotypic variables at various levels of granularity in order to diagnose, stage and plan treatments for disease states is highly desirable. Numerous techniques exist that can be used to develop networks of co-expressed or otherwise related genes and clinical features. Such techniques can also be used to create formalized knowledge collections based upon the information incumbent to ontologies and domain literature. However, reports of integrative approaches that bridge such networks to create systems-level models of disease or wellness are notably lacking in the contemporary literature. Results In response to the preceding gap in knowledge and practice, we report upon a prototypical series of experiments that utilize multi-modal approaches to network induction. These experiments are intended to elicit meaningful and significant biomarker-phenotype complexes spanning multiple levels of granularity. This work has been performed in the experimental context of a large-scale clinical and basic science data repository maintained by the National Cancer Institute (NCI) funded Chronic Lymphocytic Leukemia Research Consortium. Conclusions Our results indicate that it is computationally tractable to link orthogonal networks of genes, clinical features, and conceptual knowledge to create multi-dimensional models of interrelated biomarkers and phenotypes. Further, our results indicate that such systems-level models contain interrelated bio-molecular and clinical markers capable of supporting hypothesis discovery and testing. Based on such findings, we propose a conceptual model intended to inform the cross-linkage of the results of such methods. This model has as its aim the identification of novel and knowledge-anchored biomarker-phenotype complexes.

2010-01-01

62

Approximating MultiDimensional Aggregate Range Queries over Real Attributes  

Microsoft Academic Search

Finding approximate answers to multi-dimensional range queries over real valued attributes has significantapplications in data exploration and database query optimization. In this paper we consider thefollowing problem: given a table of d attributes whose domain is the real numbers, and a query thatspecifies a range in each dimension, find a good approximation of the number of records in the table

Dimitrios Gunopulos; George Kollios; Vassilis J. Tsotras; Carlotta Domeniconi

2000-01-01

63

Image matrix processor for fast multi-dimensional computations  

DOEpatents

An apparatus for multi-dimensional computation is disclosed which comprises a computation engine, including a plurality of processing modules. The processing modules are configured in parallel and compute respective contributions to a computed multi-dimensional image of respective two dimensional data sets. A high-speed, parallel access storage system is provided which stores the multi-dimensional data sets, and a switching circuit routes the data among the processing modules in the computation engine and the storage system. A data acquisition port receives the two dimensional data sets representing projections through an image, for reconstruction algorithms such as encountered in computerized tomography. The processing modules include a programmable local host, by which they may be configured to execute a plurality of different types of multi-dimensional algorithms. The processing modules thus include an image manipulation processor, which includes a source cache, a target cache, a coefficient table, and control software for executing image transformation routines using data in the source cache and the coefficient table and loading resulting data in the target cache. The local host processor operates to load the source cache with a two dimensional data set, loads the coefficient table, and transfers resulting data out of the target cache to the storage system, or to another destination. 10 figs.

Roberson, G.P.; Skeate, M.F.

1996-10-15

64

Multi-dimensional shock capturing by nonconservative scheme  

NASA Astrophysics Data System (ADS)

A nonconservative CIP (Cubic-Interpolated Pseudoparticle) scheme is applied to multi-dimensional shock waves. The scheme successfully captured both shock wave and contact discontinuity. Cylindrical shock waves have been described well by this scheme even in a rectangular Cartesian grid.

Xiao, Feng; Yabe, Takashi

1992-12-01

65

Large Aperture Multi-Dimensional Laser Radar Testbed.  

National Technical Information Service (NTIS)

A 39 cm aperture multi-dimensional laser radar has been built and made operational. This sensor acquires pixel registered range, Doppler, 3-5 micrometer passive, and visible passive data. Range is digitized at 200 MHz for .75 m range resolution. Doppler i...

D. U. Fluckiger M. P. Boldue L. A. Prior

1988-01-01

66

Image matrix processor for fast multi-dimensional computations  

DOEpatents

An apparatus for multi-dimensional computation which comprises a computation engine, including a plurality of processing modules. The processing modules are configured in parallel and compute respective contributions to a computed multi-dimensional image of respective two dimensional data sets. A high-speed, parallel access storage system is provided which stores the multi-dimensional data sets, and a switching circuit routes the data among the processing modules in the computation engine and the storage system. A data acquisition port receives the two dimensional data sets representing projections through an image, for reconstruction algorithms such as encountered in computerized tomography. The processing modules include a programmable local host, by which they may be configured to execute a plurality of different types of multi-dimensional algorithms. The processing modules thus include an image manipulation processor, which includes a source cache, a target cache, a coefficient table, and control software for executing image transformation routines using data in the source cache and the coefficient table and loading resulting data in the target cache. The local host processor operates to load the source cache with a two dimensional data set, loads the coefficient table, and transfers resulting data out of the target cache to the storage system, or to another destination.

Roberson, George P. (Tracy, CA); Skeate, Michael F. (Livermore, CA)

1996-01-01

67

Parameterized multi-dimensional data encryption by digital optics  

NASA Astrophysics Data System (ADS)

A new parameterized multi-dimensional data encryption method is presented in this paper. Several geometric and physical parameters derived out from a configuration of digital optics have been suggested as tools for designing multiple locks and keys for data encryption in hyperspace. Numerical experiments are performed to validate proposed method and parameters sensitivities are also quantitatively analyzed and illustrated with numerical simulations.

Yu, Lingfeng; Peng, Xiang; Cai, Lilong

2002-03-01

68

Dependence of multi-dimensional array references  

Microsoft Academic Search

Accurate data dependence analysis is the key function in vectorizing-restructuring compilers for supercomputers. However, the data dependence analysis algorithms currently available have limitations. Those that execute quickly, such as the Banerjee Test [3], [4], [21] are very limited in generality. Those that are general are too slow. 1 Compiler designers have been keenly aware of the need for an algorithm

David R. Wallace

1988-01-01

69

Towards Semantic Web Services on Large, Multi-Dimensional Coverages  

NASA Astrophysics Data System (ADS)

Observed and simulated data in the Earth Sciences often come as coverages, the general term for space-time varying phenomena as set forth by standardization bodies like the Open GeoSpatial Consortium (OGC) and ISO. Among such data are 1-d time series, 2-D surface data, 3-D surface data time series as well as x/y/z geophysical and oceanographic data, and 4-D metocean simulation results. With increasing dimensionality the data sizes grow exponentially, up to Petabyte object sizes. Open standards for exploiting coverage archives over the Web are available to a varying extent. The OGC Web Coverage Service (WCS) standard defines basic extraction operations: spatio-temporal and band subsetting, scaling, reprojection, and data format encoding of the result - a simple interoperable interface for coverage access. More processing functionality is available with products like Matlab, Grid-type interfaces, and the OGC Web Processing Service (WPS). However, these often lack properties known as advantageous from databases: declarativeness (describe results rather than the algorithms), safe in evaluation (no request can keep a server busy infinitely), and optimizable (enable the server to rearrange the request so as to produce the same result faster). WPS defines a geo-enabled SOAP interface for remote procedure calls. This allows to webify any program, but does not allow for semantic interoperability: a function is identified only by its function name and parameters while the semantics is encoded in the (only human readable) title and abstract. Hence, another desirable property is missing, namely an explicit semantics which allows for machine-machine communication and reasoning a la Semantic Web. The OGC Web Coverage Processing Service (WCPS) language, which has been adopted as an international standard by OGC in December 2008, defines a flexible interface for the navigation, extraction, and ad-hoc analysis of large, multi-dimensional raster coverages. It is abstract in that it does not anticipate any particular protocol. One such protocol is given by the OGC Web Coverage Service (WCS) Processing Extension standard which ties WCPS into WCS. Another protocol which makes WCPS an OGC Web Processing Service (WPS) Profile is under preparation. Thereby, WCPS bridges WCS and WPS. The conceptual model of WCPS relies on the coverage model of WCS, which in turn is based on ISO 19123. WCS currently addresses raster-type coverages where a coverage is seen as a function mapping points from a spatio-temporal extent (its domain) into values of some cell type (its range). A retrievable coverage has an identifier associated, further the CRSs supported and, for each range field (aka band, channel), the interpolation methods applicable. The WCPS language offers access to one or several such coverages via a functional, side-effect free language. The following example, which derives the NDVI (Normalized Difference Vegetation Index) from given coverages C1, C2, and C3 within the regions identified by the binary mask R, illustrates the language concept: for c in ( C1, C2, C3 ), r in ( R ) return encode( (char) (c.nir - c.red) / (c.nir + c.red), H˜DF-EOS\\~ ) The result is a list of three HDF-EOS encoded images containing masked NDVI values. Note that the same request can operate on coverages of any dimensionality. The expressive power of WCPS includes statistics, image, and signal processing up to recursion, to maintain safe evaluation. As both syntax and semantics of any WCPS expression is well known the language is Semantic Web ready: clients can construct WCPS requests on the fly, servers can optimize such requests (this has been investigated extensively with the rasdaman raster database system) and automatically distribute them for processing in a WCPS-enabled computing cloud. The WCPS Reference Implementation is being finalized now that the standard is stable; it will be released in open source once ready. Among the future tasks is to extend WCPS to general meshes, in synchronization with the WCS standard. In this talk WCPS is presented in the context

Baumann, P.

2009-04-01

70

Analysis of methionine enkephalin in human pituitary by multi-dimensional reversed-phase high-performance liquid chromatography, radioreceptor assay, radioimmunoassay, fast atom bombardment mass spectrometry, and mass spectrometry-mass spectrometry.  

PubMed

Methionine enkephalin (ME = YGGFM) was measured in five individual human post-mortem pituitaries using four different analytical methods, with the objective of comparing the molecular specificities of the methods. Radioreceptor assay (RRA) used a receptor-rich preparation from brain and [3H]etorphine as radioligand to determine ME-like receptoractivity (ME-LR). Radioimmunoassay (RIA) measured ME-like immunoreactivity (ME-LI). Pituitary samples analyzed by RRA and RIA were purified first with a high-performance liquid chromatography (HPLC) gradient on a polymer analytical column. Fast atom bombardment mass spectrometry (FAB-MS) in two different detection modes quantified ME using the protonated molecular ion MH+ of ME at 574 a.m.u. and B/E linked-field selected reaction monitoring (SRM) to monitor the specific unimolecular metastable transition that produced the unique amino acid sequence-determining tetrapeptide fragment ion YGGFA+ from the MH+ precursor ion. Both FAB-MS methods used the deuterated internal standard YGG[2H5-F]M. Samples analyzed with FAB-MS were purified first with multi-dimensional reversed-phase HPLC. The first dimension was an ODS gradient, and the second dimension was a polymer isocratic elution. The following ME amounts were measured (mean +/- standard error of the mean): ME-LR, 7.0 +/- 1.9 micrograms g-1 tissue; ME-LI, 1.8 +/- 0.7 micrograms g-1 tissue; MH+, 2.7 +/- 0.6 micrograms g-1 tissue; SRM, 3.0 +/- 0.8 micrograms g-1 tissue. The FAB SRM method provided the highest level of molecular specificity amount these four analytical methods used to measure picomole amounts of endogenous ME in a human pituitary. PMID:2026720

Lovelace, J L; Kusmierz, J J; Desiderio, D M

1991-01-01

71

Texture Mapping using Surface Flattening via MultiDimensional Scaling  

Microsoft Academic Search

We present a novel technique for texture map- ping on arbitrary surfaces with minimal distortions, by pre- serving the local and global structure of the texture. The recent introduction of the fast marching method on trian- gulated surfaces, made it possible to compute a geodesic distance map from a given surface point in O(nlgn) opera- tions, where n is the

Gil Zigelman; Ron Kimmel; Nahum Kiryati

2001-01-01

72

Advanced numerics for multi-dimensional fluid flow calculations  

SciTech Connect

In recent years, there has been a growing interest in the development and use of mathematical models for the simulation of fluid flow, heat transfer and combustion processes in engineering equipment. The equations representing the multi-dimensional transport of mass, momenta and species are numerically solved by finite-difference or finite-element techniques. However despite the multiude of differencing schemes and solution algorithms, and the advancement of computing power, the calculation of multi-dimensional flows, especially three-dimensional flows, remains a mammoth task. The following discussion is concerned with the author's recent work on the construction of accurate discretization schemes for the partial derivatives, and the efficient solution of the set of nonlinear algebraic equations resulting after discretization. The present work has been jointly supported by the Ramjet Engine Division of the Wright Patterson Air Force Base, Ohio, and the NASA Lewis Research Center.

Vanka, S.P.

1984-04-01

73

Efficient Subtorus Processor Allocation in a Multi-Dimensional Torus  

SciTech Connect

Processor allocation in a mesh or torus connected multicomputer system with up to three dimensions is a hard problem that has received some research attention in the past decade. With the recent deployment of multicomputer systems with a torus topology of dimensions higher than three, which are used to solve complex problems arising in scientific computing, it becomes imminent to study the problem of allocating processors of the configuration of a torus in a multi-dimensional torus connected system. In this paper, we first define the concept of a semitorus. We present two partition schemes, the Equal Partition (EP) and the Non-Equal Partition (NEP), that partition a multi-dimensional semitorus into a set of sub-semitori. We then propose two processor allocation algorithms based on these partition schemes. We evaluate our algorithms by incorporating them in commonly used FCFS and backfilling scheduling policies and conducting simulation using workload traces from the Parallel Workloads Archive. Specifically, our simulation experiments compare four algorithm combinations, FCFS/EP, FCFS/NEP, backfilling/EP, and backfilling/NEP, for two existing multi-dimensional torus connected systems. The simulation results show that our algorithms (especially the backfilling/NEP combination) are capable of producing schedules with system utilization and mean job bounded slowdowns comparable to those in a fully connected multicomputer.

Weizhen Mao; Jie Chen; William Watson

2005-11-30

74

Portable laser synthesizer for high-speed multi-dimensional spectroscopy  

SciTech Connect

Portable, field-deployable laser synthesizer devices designed for multi-dimensional spectrometry and time-resolved and/or hyperspectral imaging include a coherent light source which simultaneously produces a very broad, energetic, discrete spectrum spanning through or within the ultraviolet, visible, and near infrared wavelengths. The light output is spectrally resolved and each wavelength is delayed with respect to each other. A probe enables light delivery to a target. For multidimensional spectroscopy applications, the probe can collect the resulting emission and deliver this radiation to a time gated spectrometer for temporal and spectral analysis.

Demos, Stavros G. (Livermore, CA); Shverdin, Miroslav Y. (Sunnyvale, CA); Shirk, Michael D. (Brentwood, CA)

2012-05-29

75

Multi-dimensional hydrodynamics of core-collapse supernovae  

NASA Astrophysics Data System (ADS)

Core-collapse supernovae are some of the most energetic events in the Universe, they herald the birth of neutron stars and black holes, are a major site for nucleosynthesis, influence galactic hydrodynamics, and trigger further star formation. As such, it is important to understand the mechanism of explosion. Moreover, observations imply that asymmetries are, in the least, a feature of the mechanism, and theory suggests that multi-dimensional hydrodynamics may be crucial for successful explosions. In this dissertation, we present theoretical investigations into the multi-dimensional nature of the supernova mechanism. It had been suggested that nuclear reactions might excite non-radial g-modes (the [straight epsilon]-mechanism) in the cores of progenitors, leading to asymmetric explosions. We calculate the eigenmodes for a large suite of progenitors including excitation by nuclear reactions and damping by neutrino and acoustic losses. Without exception, we find unstable g-modes for each progenitor. However, the timescales for growth are at least an order of magnitude longer than the time until collapse. Thus, the [straight epsilon]- mechanism does not provide appreciable amplification of non-radial modes before the core undergoes collapse. Regardless, neutrino-driven convection, the standing accretion shock instability, and other instabilities during the explosion provide ample asymmetry. To adequately simulate these, we have developed a new hydrodynamics code, BETHE-hydro that uses the Arbitrary Lagrangian-Eulerian (ALE) approach, includes rotational terms, solves Poisson's equation for gravity on arbitrary grids, and conserves energy and momentum in its basic implementation. By using time-dependent arbitrary grids that can adapt to the numerical challenges of the problem, this code offers unique flexibility in simulating astrophysical phenomena. Finally, we use BETHE-hydro to investigate the conditions and criteria for supernova explosions by the neutrino mechanism. We find that a critical- luminosity/mass-accretion-rate condition distinguishes non-exploding from exploding models in hydrodynamic 1D and 2D simulations. Importantly, the critical luminosity for 2D simulations is found to be 70% of the critical luminosity for 1D simulations. We identify the specifics of multi-dimensional hydrodynamic simulations that enable explosions at lower neutrino luminosities in 2D and discuss how these results might foreshadow successful explosions by eventual 3D radiation-hydrodynamic simulations.

Murphy, Jeremiah W.

76

A Multi-Dimensional Classification Model for Scientific Workflow Characteristics  

SciTech Connect

Workflows have been used to model repeatable tasks or operations in manufacturing, business process, and software. In recent years, workflows are increasingly used for orchestration of science discovery tasks that use distributed resources and web services environments through resource models such as grid and cloud computing. Workflows have disparate re uirements and constraints that affects how they might be managed in distributed environments. In this paper, we present a multi-dimensional classification model illustrated by workflow examples obtained through a survey of scientists from different domains including bioinformatics and biomedical, weather and ocean modeling, astronomy detailing their data and computational requirements. The survey results and classification model contribute to the high level understandingof scientific workflows.

Ramakrishnan, Lavanya; Plale, Beth

2010-04-05

77

The multi-dimensional Hamiltonian structures in the Whitham method  

NASA Astrophysics Data System (ADS)

We consider the averaging of local field-theoretic Poisson brackets in the multi-dimensional case. As a result, we construct a local Poisson bracket for the regular Whitham system in the multidimensional situation. The procedure is based on the procedure of averaging of local conservation laws and follows the Dubrovin-Novikov scheme of the bracket averaging suggested in one-dimensional case. However, the features of the phase space of modulated parameters in higher dimensions lead to a different natural class of the averaged brackets in comparison with the one-dimensional situation. Here we suggest a direct procedure of construction of the bracket for the Whitham system for d > 1 and discuss the conditions of applicability of the corresponding scheme. At the end, we discuss canonical forms of the averaged Poisson bracket in the multidimensional case.

Maltsev, A. Ya.

2013-05-01

78

Development of a multi-dimensional measure of resilience in adolescents: the Adolescent Resilience Questionnaire  

PubMed Central

Background The concept of resilience has captured the imagination of researchers and policy makers over the past two decades. However, despite the ever growing body of resilience research, there is a paucity of relevant, comprehensive measurement tools. In this article, the development of a theoretically based, comprehensive multi-dimensional measure of resilience in adolescents is described. Methods Extensive literature review and focus groups with young people living with chronic illness informed the conceptual development of scales and items. Two sequential rounds of factor and scale analyses were undertaken to revise the conceptually developed scales using data collected from young people living with a chronic illness and a general population sample. Results The revised Adolescent Resilience Questionnaire comprises 93 items and 12 scales measuring resilience factors in the domains of self, family, peer, school and community. All scales have acceptable alpha coefficients. Revised scales closely reflect conceptually developed scales. Conclusions It is proposed that, with further psychometric testing, this new measure of resilience will provide researchers and clinicians with a comprehensive and developmentally appropriate instrument to measure a young person's capacity to achieve positive outcomes despite life stressors.

2011-01-01

79

Large-scale SAR analysis.  

PubMed

The analysis of structure–activity relationships (SARs) is a central task in medicinal chemistry. Traditionally, SAR exploration has concentrated on individual compound series. This conventional approach is complemented by large-scale SAR analysis, which puts strong emphasis on data mining and SAR visualization. This contribution reviews recent concepts for large-scale SAR analysis including numerical functions to characterize global and local SAR information content of compound data sets, alternative activity landscape representations and data mining strategies. PMID:24050139

Bajorath, Jürgen

2013-09-01

80

Surface extraction from multi-field particle volume data using multi-dimensional cluster visualization.  

PubMed

Data sets resulting from physical simulations typically contain a multitude of physical variables. It is, therefore, desirable that visualization methods take into account the entire multi-field volume data rather than concentrating on one variable. We present a visualization approach based on surface extraction from multi-field particle volume data. The surfaces segment the data with respect to the underlying multi-variate function. Decisions on segmentation properties are based on the analysis of the multi-dimensional feature space. The feature space exploration is performed by an automated multi-dimensional hierarchical clustering method, whose resulting density clusters are shown in the form of density level sets in a 3D star coordinate layout. In the star coordinate layout, the user can select clusters of interest. A selected cluster in feature space corresponds to a segmenting surface in object space. Based on the segmentation property induced by the cluster membership, we extract a surface from the volume data. Our driving applications are Smoothed Particle Hydrodynamics (SPH) simulations, where each particle carries multiple properties. The data sets are given in the form of unstructured point-based volume data. We directly extract our surfaces from such data without prior resampling or grid generation. The surface extraction computes individual points on the surface, which is supported by an efficient neighborhood computation. The extracted surface points are rendered using point-based rendering operations. Our approach combines methods in scientific visualization for object-space operations with methods in information visualization for feature-space operations. PMID:18989000

Linsen, Lars; Van Long, Tran; Rosenthal, Paul; Rosswog, Stephan

81

A global inversion method for multi-dimensional NMR logging  

NASA Astrophysics Data System (ADS)

We describe a general global inversion methodology of multi-dimensional NMR logging for pore fluid typing and quantification in petroleum exploration. Although higher dimensions are theoretically possible, for practical reasons, we limit our discussion of proton density distributions as a function of two (2D) or three (3D) independent variables. The 2D can be diffusion coefficient and T2 relaxation time (D T2), and the 3D can be diffusion coefficient, T2, and T1 relaxation times (D T2 T1) of the saturating fluids in rocks. Using the contrast between the diffusion coefficients of fluids (oil and water), the oil and water phases within the rocks can be clearly identified. This 2D or 3D proton density distribution function can be obtained from either two-window or regular type multiple CPMG echo trains encoded with diffusion, T1, and T2 relaxation by varying echo spacing and wait time. From this 2D/3D proton density distribution function, not only the saturations of water and oil can be determined, the viscosity of the oil and the gas oil ratio can also be estimated based on a previously experimentally determined D T2 relationship.

Sun, Boqin; Dunn, Keh-Jim

2005-01-01

82

Comparative application and analysis from a one dimensional and a multi-dimensional routing scheme and its impact on process oriented hydrological modeling with the Jena Adaptable Modelling System (JAMS) and the integrated hydrological, nutrient transport and erosion modeling system J2000-S-E  

NASA Astrophysics Data System (ADS)

Fully spatially distributed hydrological modeling requires a topological linkage of single modeling entities (e.g. Hydrological Response Units - HRU) in order to reproduce relevant attenuation and translation processes within the stream but also during the transport of water in form of lateral surface or subsurface flow. Most often such linkage is considered by a one dimensional (1D) approach which links one modeling entity to only one receiver that follows in flow direction. The comparison with actual lateral water movement in catchments show that such a 1D routing scheme is often too simple which can lead to an overestimation of the runoff concentration along the 1D flow paths. On the other hand an underestimation of runoff in flow cascades that do not reside next to the main 1D flow paths can occur as the affected HRUs don’t receive realistic inflow from their source entities above. As a catchment-wide consequence the 1D routing scheme can result in a significant over- or underestimation of the contributing area for specific parts of a catchment which can have important implications on the spatial distribution of accompanying processes such as spatial variation of soil moisture, soil erosion or nutrient/contaminant transport. To address the problems outlined above a new approach has been developed that allows a multi-dimensional linkage of model entities in such a way that each entity can have various receivers to which the water is passed. This extended routing scheme was implemented in the hydrological, nutrient transport and erosion modeling system J2000-S-E and was used for the simulation of the hydrological processes of a number of meso-scaled catchments in Thuringia, Germany. This work will present the most important facts of the extended routing scheme, the simulation results along with the comparison of those obtained with the 1D linkage and will highlight the impacts on the hydrological process dynamics as well as on the HRU-based mass transport and balancing.

Kipka, H.; Pfennig, B.; Fink, M.; Kralisch, S.; Krause, P.; Flügel, W.

2010-12-01

83

Stochastic Modeling of Multi-Dimensional Precipitation Fields.  

NASA Astrophysics Data System (ADS)

A new multi-dimensional stochastic precipitation model is proposed with major emphasis on its spectral structure. As a hyperbolic type of stochastic partial differential equation, this model is characterized by having a small set of parameters, which could be easily estimated. These characteristics are similar to those of the noise forced diffusive precipitation model, but representation of the physics and statistical features of the precipitation field is better as in the WGR precipitation model. The model derivation was based on the AR (Auto Regressive) process considering advection and diffusion, the dominant statistical and physical characteristics of the precipitation field propagation. The model spectrum showed a good match for the GATE spectrum developed by Nakamoto et al. (1990). This model was also compared with the WGR model and the noise forced diffusive precipitation model analytically and through applications such as the sampling error estimation from space-borne sensors and raingages, and the ground-truth problem. The sampling error from space-borne sensors based on the proposed model was similar to that of the noise forced diffusive precipitation model but much smaller than that of the WGR model. Similar result was also obtained in the estimation of the sampling error from raingages. The dimensionless root mean square error of the proposed model in the ground-truth problem was in between those of the WGR model and the noise forced diffusive precipitation model, even though the difference was very small. Simulation study of the realistic precipitation field showed the effect of the variance of the noise forcing term on the life time of a storm event.

Yoo, Chulsang

1995-01-01

84

Supporting Complex MultiDimensional Queries in P2P Systems  

Microsoft Academic Search

More and more applications require peer-to-peer (P2P) systems to support complex queries over multi-dimensional data. For example, a P2P auction network for real estate frequently needs to answer queries such as \\

Bin Liu; Dik Lun Lee

2005-01-01

85

Implementation of adaptive processing in integrated active-passive sonars with multi-dimensional arrays  

Microsoft Academic Search

The investigation reported includes a multi-dimensional array sonar for underwater robotics operations, such as mine hunting. The various aspects of robotics arrangements for the ROV are discussed in association with the sonar performance characteristics provided by the integrated functionality of the multi-dimensional array sonar including an adaptive beamformer. The proposed adaptive processing concept has been implemented in an integrated active-passive

S. Stergiopoulos; A. C. Dhanantwari

1998-01-01

86

On fault diagnosis of analogue electronic circuits based on transformations in multi-dimensional spaces  

Microsoft Academic Search

In the paper new methods of fault localisation and identification in linear electronic circuits (two-port or multi-port type) based on bilinear transformations in multi-dimensional spaces are presented. The novelty of these methods lies in transferring a family of identification loci from a plane to multi-dimensional spaces. It implies greater distances between the loci and, in consequence, better fault resolution as

Zbigniew Czaja; Romuald Zielonko

2004-01-01

87

Importance of multi-dimensional conductive heat flows in and around buildings  

Microsoft Academic Search

The modelling of certain structures in a manner consistent with current practice can lead to significant errors as a result of the non-treatment of multi-dimensional conductive heat flows. A series of multi-dimensional simulations using a modified whole building thermal simulation model have been performed in order to highlight this problem. As a result, it is suggested that all building thermal

M. Davies; A. Tindale; J. Littler

1995-01-01

88

Towards multi-dimensional robotic control via noninvasive brain-computer interface  

Microsoft Academic Search

Brain-computer interface (BCI) provides a new communication pathway for patients with neurological disorders who may not make voluntary muscle contraction. A potential BCI application is that patients may control a neuro-prosthetic robot directly from their brain so that they can achieve virtual interaction with environment. Therefore, a BCI supports multi-dimensional control is highly demanded for a multi-dimensional robot. We hypothesized

Xuedong Chen; Ou Bai

2009-01-01

89

All-optical multi-dimensional imaging of energy-materials beyond the diffraction limit  

NASA Astrophysics Data System (ADS)

Efficient, environmentally-friendly, harvesting, storage, transport and conversion of energy are some of the foremost challenges now facing mankind. An important facet of this challenge is the development of new materials with improved electronic and photonic properties. Nano-scale metrology will be important in developing these materials, and optical methods have many advantages over electrons or proximal probes. To surpass the diffraction limit, near-field methods can be used. Alternatively, the concept of imaging in a multi-dimensional space is employed, where, in addition to spatial dimensions, the added dimensions of energy and time allow to distinguish objects which are closely spaced, and in effect increase the achievable resolution of optical microscopy towards the molecular level. We have employed these methods towards the study of materials relevant to renewable energy processes. Specifically, we image the position and orientation of single carbohydrate binding modules and visualize their interaction with cellulose with ~ 10nm resolution, an important step in identifying the molecular underpinnings of bio-processing and the development of low-cost alternative fuels, and describe our current work implementing these concepts towards characterizing the ultrafast carrier dynamics (~ 100fs) in a new class of nano-structured solar cells, predicted to have theoretical efficiencies exceeding 60%, using femtosecond laser spectroscopy.

Smith, Steve; Dagel, D. J.; Zhong, L.; Kolla, P.; Ding, S.-Y.

2011-09-01

90

Psychometric properties and confirmatory factor analysis of the Jefferson Scale of Physician Empathy  

PubMed Central

Background Empathy towards patients is considered to be associated with improved health outcomes. Many scales have been developed to measure empathy in health care professionals and students. The Jefferson Scale of Physician Empathy (JSPE) has been widely used. This study was designed to examine the psychometric properties and the theoretical structure of the JSPE. Methods A total of 853 medical students responded to the JSPE questionnaire. A hypothetical model was evaluated by structural equation modelling to determine the adequacy of goodness-of-fit to sample data. Results The model showed excellent goodness-of-fit. Further analysis showed that the hypothesised three-factor model of the JSPE structure fits well across the gender differences of medical students. Conclusions The results supported scale multi-dimensionality. The 20 item JSPE provides a valid and reliable scale to measure empathy among not only undergraduate and graduate medical education programmes, but also practising doctors. The limitations of the study are discussed and some recommendations are made for future practice.

2011-01-01

91

Steps Toward a Large-Scale Solar Image Data Analysis to Differentiate Solar Phenomena  

NASA Astrophysics Data System (ADS)

We detail the investigation of the first application of several dissimilarity measures for large-scale solar image data analysis. Using a solar-domain-specific benchmark dataset that contains multiple types of phenomena, we analyzed combinations of image parameters with different dissimilarity measures to determine the combinations that will allow us to differentiate between the multiple solar phenomena from both intra-class and inter-class perspectives, where by class we refer to the same types of solar phenomena. We also investigate the problem of reducing data dimensionality by applying multi-dimensional scaling to the dissimilarity matrices that we produced using the previously mentioned combinations. As an early investigation into dimensionality reduction, we investigate by applying multidimensional scaling (MDS) how many MDS components are needed to maintain a good representation of our data (in a new artificial data space) and how many can be discarded to enhance our querying performance. Finally, we present a comparative analysis of several classifiers to determine the quality of the dimensionality reduction achieved with this combination of image parameters, similarity measures, and MDS.

Banda, J. M.; Angryk, R. A.; Martens, P. C. H.

2013-05-01

92

Continuation and bifurcation analysis of large-scale dynamical systems with LOCA.  

SciTech Connect

Dynamical systems theory provides a powerful framework for understanding the behavior of complex evolving systems. However applying these ideas to large-scale dynamical systems such as discretizations of multi-dimensional PDEs is challenging. Such systems can easily give rise to problems with billions of dynamical variables, requiring specialized numerical algorithms implemented on high performance computing architectures with thousands of processors. This talk will describe LOCA, the Library of Continuation Algorithms, a suite of scalable continuation and bifurcation tools optimized for these types of systems that is part of the Trilinos software collection. In particular, we will describe continuation and bifurcation analysis techniques designed for large-scale dynamical systems that are based on specialized parallel linear algebra methods for solving augmented linear systems. We will also discuss several other Trilinos tools providing nonlinear solvers (NOX), eigensolvers (Anasazi), iterative linear solvers (AztecOO and Belos), preconditioners (Ifpack, ML, Amesos) and parallel linear algebra data structures (Epetra and Tpetra) that LOCA can leverage for efficient and scalable analysis of large-scale dynamical systems.

Salinger, Andrew Gerhard; Phipps, Eric Todd; Pawlowski, Roger Patrick

2010-06-01

93

Solution technique for a multi-dimensional population balance model describing granulation processes  

Microsoft Academic Search

An efficient and novel solution technique is presented for solving multi-dimensional population balance models. In addition to overcoming stiffness in the original system, the algorithm also reduces the computational load by proposing a priori semi-analytical solutions for a major part of the aggregation quadratures (calculations performed once at the start of the simulation). The new technique gives very good solution

Charles David Immanuel; Francis Joseph Doyle

2005-01-01

94

A combined discontinuous Galerkin and finite volume scheme for multi-dimensional VPFP system  

SciTech Connect

We construct a numerical scheme for the multi-dimensional Vlasov-Poisson-Fokker-Planck system based on a combined finite volume (FV) method for the Poisson equation in spatial domain and the streamline diffusion (SD) and discontinuous Galerkin (DG) finite element in time, phase-space variables for the Vlasov-Fokker-Planck equation.

Asadzadeh, M.; Bartoszek, K. [Department of Mathematics, Chalmers University of Technology and University of Gothenburg SE-412 96 Goeteborg (Sweden)

2011-05-20

95

Developing a Hypothetical Multi-Dimensional Learning Progression for the Nature of Matter  

ERIC Educational Resources Information Center

|We describe efforts toward the development of a hypothetical learning progression (HLP) for the growth of grade 7-14 students' models of the structure, behavior and properties of matter, as it relates to nanoscale science and engineering (NSE). This multi-dimensional HLP, based on empirical research and standards documents, describes how students…

Stevens, Shawn Y.; Delgado, Cesar; Krajcik, Joseph S.

2010-01-01

96

Developing Multi-Dimensional Evaluation Criteria for English Learning Websites with University Students and Professors  

ERIC Educational Resources Information Center

|Many English learning websites have been developed worldwide, but little research has been conducted concerning the development of comprehensive evaluation criteria. The main purpose of this study is thus to construct a multi-dimensional set of criteria to help learners and teachers evaluate the quality of English learning websites. These…

Liu, Gi-Zen; Liu, Zih-Hui; Hwang, Gwo-Jen

2011-01-01

97

Developing multi-dimensional evaluation criteria for English learning websites with university students and professors  

Microsoft Academic Search

Many English learning websites have been developed worldwide, but little research has been conducted concerning the development of comprehensive evaluation criteria. The main purpose of this study is thus to construct a multi-dimensional set of criteria to help learners and teachers evaluate the quality of English learning websites. These evaluation guidelines are based on web usability, learning materials, functionality of

Gi-Zen Liu; Zih-Hui Liu; Gwo-Jen Hwang

2011-01-01

98

Stress concentration factor prediction by the multi-dimensional Lagrangian interpolation method  

Microsoft Academic Search

A new approach based on the multi-dimensional Lagrangian interpolation method, which is widely used in the finite element method, is proposed for the prediction of stress concentration factor for tubular joints. When comparing with the parametric regression method, this new method uses the same set of numerical parametric study results as its inputs. The accuracy of the proposed method is

C. K. Lee; S. P. Chiew; S. T. Lie; T. Sopha

2011-01-01

99

Transportation feature oriented multi-dimensional navigation data model  

Microsoft Academic Search

There are three functional requirements that a transportation network data model for dynamic navigation must meet, which are spatio-temporal representation of dynamic traffic information, muiti-scale representation of road network, and carriageway-based representation of topological and transportation relationships of road network. However, existing models, including some navigable data models, GIS-T linear data models, and GIS-T spatio-temporal data models, rarely support these

Song Ying; Li Hongyan

2010-01-01

100

HYPERS: First Ever Multi-Dimensional Asynchronous Hybrid Simulations  

NASA Astrophysics Data System (ADS)

Hybrid (electron fluid, kinetic ion) simulations have recently emerged in large-scale laboratory (spheromak, FRC) and global magnetospheric studies with the goal of accurately predicting energetic particle transport in complex plasma/magnetic configurations. Multiple temporal scales associated with both plasma and magnetic field inhomogeneities force severe restrictions on the global timestep in time-stepped hybrid simulations. We present an alternative computational tool for multi-scale plasma modeling: a first-ever uni-dimensional (2D or 3D chosen at compile time) asynchronous hybrid code, HYPERS (HYbrid-Particle Event-Resolved Simulation). HYPERS is currently being developed as part of the Virtual Hybrid Particle Laboratory (VHPL) in support of the SSX experiment at Swarthmore. It discards traditional time stepping in favor of the Discrete-Event Simulation (DES) approach [1]. Time increments for individual particles and local electromagnetic fields are adaptively selected through limiting per-update changes of their properties. This enables fast, reliable and accurate simulations of energetic plasmas immersed in highly inhomogeneous magnetic fields. Preliminary results from 2D simulations of the interaction of streaming plasmas with magnetic dipoles are discussed. We also report our undergoing efforts on developing efficient dynamic load-balancing strategies for future parallel HYPERS runs on petascale architectures. In this initial development phase, we are exploring tradeoffs of developing 2D/3D variations of extremely fast 1D load balancing heuristics such as chain-on-chain partitioning versus using fast geometry-based heuristics.

Omelchenko, Y.; Karimabadi, H.; Catalyurek, U.; Saule, E.; Brown, M. R.

2009-12-01

101

Multi-dimensional phenotyping: towards a new taxonomy for airway disease.  

PubMed

All the real knowledge which we possess, depends on methods by which we distinguish the similar from the dissimilar. The greater the number of natural distinctions this method comprehends the clearer becomes our idea of things. The more numerous the objects which employ our attention the more difficult it becomes to form such a method and the more necessary. Classification is a fundamental part of medicine. Diseases are often categorized according to pre-20th century descriptions and concepts of disease based on symptoms, signs and functional abnormalities rather than on underlying pathogenesis. Where the aetiology of disease has been revealed (for example in the infectious diseases) a more precise classification has become possible, but in the chronic inflammatory diseases, and in the inflammatory airway diseases in particular, where pathogenesis has been stubbornly difficult to elucidate, we still use broad descriptive terms such as asthma and chronic obstructive pulmonary disease, which defy precise definition because they encompass a wide spectrum of presentations and physiological and cellular abnormalities. It is our contention that these broad-brush terms have outlived their usefulness and that we should be looking to create a new taxonomy of airway disease-a taxonomy that more closely reflects the spectrum of phenotypes that are encompassed within the term airway inflammatory diseases, and that gives full recognition to late 20th and 21st century insights into the disordered physiology and cell biology that characterizes these conditions in the expectation that these will map more closely to both aetiology and response to treatment. Development of this taxonomy will require a much more complete and sophisticated correlation of the many variables that make up a condition than has been usual to employ in an approach that encompasses multi-dimensional phenotyping and uses complex statistical tools such as cluster analysis. PMID:16238783

Wardlaw, A J; Silverman, M; Siva, R; Pavord, I D; Green, R

2005-10-01

102

POLARIZED LINE FORMATION IN MULTI-DIMENSIONAL MEDIA. I. DECOMPOSITION OF STOKES PARAMETERS IN ARBITRARY GEOMETRIES  

SciTech Connect

The solution of the polarized line radiative transfer (RT) equation in multi-dimensional geometries has been rarely addressed and only under the approximation that the changes of frequencies at each scattering are uncorrelated (complete frequency redistribution). With the increase in the resolution power of telescopes, being able to handle RT in multi-dimensional structures becomes absolutely necessary. In the present paper, our first aim is to formulate the polarized RT equation for resonance scattering in multi-dimensional media, using the elegant technique of irreducible spherical tensors T{sub Q}{sup K}(i, {Omega}). Our second aim is to develop a numerical method of a solution based on the polarized approximate lambda iteration (PALI) approach. We consider both complete frequency redistribution and partial frequency redistribution (PRD) in the line scattering. In a multi-dimensional geometry, the radiation field is non-axisymmetrical even in the absence of a symmetry breaking mechanism such as an oriented magnetic field. We generalize here to the three-dimensional (3D) case, the decomposition technique developed for the Hanle effect in a one-dimensional (1D) medium which allows one to represent the Stokes parameters I, Q, U by a set of six cylindrically symmetrical functions. The scattering phase matrix is expressed in terms of T{sub Q}{sup K}(i, {Omega}) (i=0,1,2, K=0,1,2, -K {<=} Q {<=} +K), with {Omega} being the direction of the outgoing ray. Starting from the definition of the source vector, we show that it can be represented in terms of six components S{sup K}{sub Q} independent of {Omega}. The formal solution of the multi-dimensional transfer equation shows that the Stokes parameters can also be expanded in terms of T{sub Q}{sup K}(i, {Omega}). Because of the 3D geometry, the expansion coefficients I{sup K}{sub Q} remain {Omega}-dependent. We show that each I{sup K}{sub Q} satisfies a simple transfer equation with a source term S{sup K}{sub Q} and that this transfer equation provides an efficient approach for handling the polarized transfer in multi-dimensional geometries. A PALI method for 3D, associated with a core-wing separation method for treating PRD, is developed. It is tested by comparison with 1D solutions, and several benchmark solutions in the 3D case are given.

Anusha, L. S.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, 2nd Block, Bangalore 560 034 (India)

2011-01-01

103

Multi-dimensional hydrocode analyses of penetrating hypervelocity impacts.  

SciTech Connect

The Eulerian hydrocode, CTH, has been used to study the interaction of hypervelocity flyer plates with thin targets at velocities from 6 to 11 km/s. These penetrating impacts produce debris clouds that are subsequently allowed to stagnate against downstream witness plates. Velocity histories from this latter plate are used to infer the evolution and propagation of the debris cloud. This analysis, which is a companion to a parallel experimental effort, examined both numerical and physics-based issues. We conclude that numerical resolution and convergence are important in ways we had not anticipated. The calculated release from the extreme states generated by the initial impact shows discrepancies with related experimental observations, and indicates that even for well-known materials (e.g., aluminum), high-temperature failure criteria are not well understood, and that non-equilibrium or rate-dependent equations of state may be influencing the results.

Saul, W. Venner; Reinhart, William Dodd; Thornhill, Tom Finley, III; Lawrence, Raymond Jeffery Jr.; Chhabildas, Lalit Chandra; Bessette, Gregory Carl

2003-08-01

104

Multi-dimensional hybrid Fourier continuation-WENO solvers for conservation laws  

NASA Astrophysics Data System (ADS)

We introduce a multi-dimensional point-wise multi-domain hybrid Fourier-Continuation/WENO technique (FC-WENO) that enables high-order and non-oscillatory solution of systems of nonlinear conservation laws, and essentially dispersionless, spectral, solution away from discontinuities, as well as mild CFL constraints for explicit time stepping schemes. The hybrid scheme conjugates the expensive, shock-capturing WENO method in small regions containing discontinuities with the efficient FC method in the rest of the computational domain, yielding a highly effective overall scheme for applications with a mix of discontinuities and complex smooth structures. The smooth and discontinuous solution regions are distinguished using the multi-resolution procedure of Harten [A. Harten, Adaptive multiresolution schemes for shock computations, J. Comput. Phys. 115 (1994) 319-338]. We consider a WENO scheme of formal order nine and a FC method of order five. The accuracy, stability and efficiency of the new hybrid method for conservation laws are investigated for problems with both smooth and non-smooth solutions. The Euler equations for gas dynamics are solved for the Mach 3 and Mach 1.25 shock wave interaction with a small, plain, oblique entropy wave using the hybrid FC-WENO, the pure WENO and the hybrid central difference-WENO (CD-WENO) schemes. We demonstrate considerable computational advantages of the new FC-based method over the two alternatives. Moreover, in solving a challenging two-dimensional Richtmyer-Meshkov instability (RMI), the hybrid solver results in seven-fold speedup over the pure WENO scheme. Thanks to the multi-domain formulation of the solver, the scheme is straightforwardly implemented on parallel processors using message passing interface as well as on Graphics Processing Units (GPUs) using CUDA programming language. The performance of the solver on parallel CPUs yields almost perfect scaling, illustrating the minimal communication requirements of the multi-domain strategy. For the same RMI test, the hybrid computations on a single GPU, in double precision arithmetics, displays five- to six-fold speedup over the hybrid computations on a single CPU. The relative speedup of the hybrid computation over the WENO computations on GPUs is similar to that on CPUs, demonstrating the advantage of hybrid schemes technique on both CPUs and GPUs.

Shahbazi, Khosro; Hesthaven, Jan S.; Zhu, Xueyu

2013-11-01

105

The concept of document warehousing for multi-dimensional modeling of textual-based business intelligence  

Microsoft Academic Search

During the past decade, data warehousing has been widely adopted in the business community. It provides multi-dimensional analyses on cumulated historical business data for helping contemporary administrative decision-making. Nevertheless, it is believed that only about 20% information can be extracted from data warehouses concerning numeric data only, the other 80% information is hidden in non-numeric data or even in documents.

Frank S. C. Tseng; Annie Y. H. Chou

2006-01-01

106

a Polarized MultiDimensional Discrete-Ordinates Radiative Transfer Model for Remote Sensing Applications  

Microsoft Academic Search

A polarized multi-dimensional radiative transfer model based on the discrete-ordinates method is developed. The model is capable of solving the monochromatic vector radiative transfer equation (VRTE) considering polarization using the four Stokes parameters and the 4 x 4 scattering phase matrix. The VRTE may be solved for systems containing thermal and\\/or collimated radiant sources as well as background sources of

Jeffrey Lawrence Haferman

1995-01-01

107

Querying multi-dimensional data indexed using the Hilbert space-filling curve  

Microsoft Academic Search

Mapping to one-dimensional values and then using a one-dimensional indexing method has been proposed as a way of indexing multi-dimensional data. Most previous related work uses the Z-Order Curve but more recently the Hilbert Curve has been considered since it has superior clustering properties. Any approach, however, can only be of practical value if there are effective methods for executing

Jonathan K. Lawder; Peter J. H. King

2001-01-01

108

Assessing e-moderation behavior from synchronous discussion protocols with a multi-dimensional methodology  

Microsoft Academic Search

The role of the human instructor in online learning has received increasingly more attention in the e-learning literature. In the present paper we focus on the particular case of human moderation of peer-to-peer debates in educational settings. A multi-dimensional methodology is proposed to identify and characterize different moderation styles in such settings. The method triangulates superficial and qualitative features of

Christa S. C. Asterhan

2011-01-01

109

Long-Time Stability of MultiDimensional Noncharacteristic Viscous Boundary Layers  

Microsoft Academic Search

We establish long-time stability of multi-dimensional noncharacteristic boundary layers of a class of hyperbolic–parabolic\\u000a systems including the compressible Navier–Stokes equations with inflow [outflow] boundary conditions, under the assumption\\u000a of strong spectral, or uniform Evans, stability. Evans stability has been verified for small-amplitude layers by Guès, Métivier,\\u000a Williams, and Zumbrun. For large-amplitude layers, it may be efficiently checked numerically, as done

Toan Nguyen; Kevin Zumbrun

2010-01-01

110

A French-Canadian Scale for Suicide Ideation for Use with Adolescents  

Microsoft Academic Search

One-hundred-and-ten French-Canadian adolescents (60 boys, 50 girls) participated in an analysis of the reliability and validity of a French version of the Scale for Suicide Ideation. Item analysis and coefficient alpha results suggested good reliability. Correlations with selected personality variables were obtained. Associations were found between suicide ideation and measures of self-esteem, multi-dimensional locus of control, life stress, depression, anomie,

A. F. DE MAN; C. P. LEDUC; L. LABRÈCHE-GAUTHIER

1993-01-01

111

Genuinely multi-dimensional explicit and implicit generalized Shapiro filters for weather forecasting, computational fluid dynamics and aeroacoustics  

NASA Astrophysics Data System (ADS)

This paper addresses the extension of one-dimensional filters in two and three space dimensions. A new multi-dimensional extension is proposed for explicit and implicit generalized Shapiro filters. We introduce a definition of explicit and implicit generalized Shapiro filters that leads to very simple formulas for the analyses in two and three space dimensions. We show that many filters used for weather forecasting, high-order aerodynamic and aeroacoustic computations match the proposed definition. Consequently the new multi-dimensional extension can be easily implemented in existing solvers. The new multi-dimensional extension and the two commonly used methods are compared in terms of compactness, robustness, accuracy and computational cost. Benefits of the genuinely multi-dimensional extension are assessed for various computations using the compressible Euler equations.

Falissard, F.

2013-11-01

112

Scaled vehicle tire characteristics: dimensionless analysis  

Microsoft Academic Search

This article demonstrates the use of dimensional analysis for scaled vehicle tires. The motivation for this approach is the understanding of realistic nonlinear tire behavior in scaled vehicle control studies. By examining the behavior of vehicle tires within a dimensionless framework, several key tire parameters are developed that allow for an appropriate relationship between full-sized tires and scaled tires. Introducing

Matthew Polley; Andrew Alleyne; Edwin De Vries

2006-01-01

113

Reshape scale method: A novel multi scale entropic analysis approach  

NASA Astrophysics Data System (ADS)

The Reshape Scale (RS) method was introduced in this article as a novel approach to perform multi scale transition of sample entropy. This method was able to quantify the orderliness in the signal by determining the distance over which the subsequent data points can remain affiliated to one another. Entropic Half Life (EnHL) was introduced to characterize such an affiliation. The method was tested for 1/f? processes for different ? values. Furthermore, the dependency of the multi scale entropy analysis developed by Costa et al. (2002) [6] to the probability density function and the standard deviation of autoregressive signals was studied and discussed.

Zandiyeh, P.; von Tscharner, V.

2013-12-01

114

Confirmatory Factor Analysis and Profile Analysis via Multidimensional Scaling  

ERIC Educational Resources Information Center

This paper describes the Confirmatory Factor Analysis (CFA) parameterization of the Profile Analysis via Multidimensional Scaling (PAMS) model to demonstrate validation of profile pattern hypotheses derived from multidimensional scaling (MDS). Profile Analysis via Multidimensional Scaling (PAMS) is an exploratory method for identifying major…

Kim, Se-Kang; Davison, Mark L.; Frisby, Craig L.

2007-01-01

115

Large-scale vulnerability analysis  

Microsoft Academic Search

The security level of networks and systems is determined by the software vulnerabilities of its elements. Defending against large scale attacks requires a quantitative understanding of the vulnerability lifecycle. Specifically, one has to understand how exploitation and remediation of vulnerabilities, as well as the distribution of information thereof is handled by industry.In this paper, we examine how vulnerabilities are handled

Stefan Frei; Martin May; Ulrich Fiedler; Bernhard Plattner

2006-01-01

116

Scale-PC shielding analysis sequences  

SciTech Connect

The SCALE computational system is a modular code system for analyses of nuclear fuel facility and package designs. With the release of SCALE-PC Version 4.3, the radiation shielding analysis community now has the capability to execute the SCALE shielding analysis sequences contained in the control modules SAS1, SAS2, SAS3, and SAS4 on a MS- DOS personal computer (PC). In addition, SCALE-PC includes two new sequences, QADS and ORIGEN-ARP. The capabilities of each sequence are presented, along with example applications.

Bowman, S.M.

1996-05-01

117

A generalized implicit algorithm for multi-dimensional particle-in-cell simulations in Cartesian geometry  

NASA Astrophysics Data System (ADS)

An implicit multi-dimensional particle-in-cell (PIC) code is developed to study the interaction of ultrashort pulse lasers with matter. The algorithm is based on current density decomposition and is only marginally more complicated compared to explicit PIC codes, but it completely eliminates grid heating and possesses good energy conserving properties with relaxed time step and grid resolution. This is demonstrated in a test case study, in which high-energy protons are generated from a thin carbon foil at solid density using linear and circular polarizations. The grid heating rate is estimated to be 1-10 eV/ps.

Petrov, G. M.; Davis, J.

2011-07-01

118

Low Mach number limit for the multi-dimensional full magnetohydrodynamic equations  

NASA Astrophysics Data System (ADS)

The low Mach number limit for the multi-dimensional full magnetohydrodynamic (MHD) equations, in which the effect of thermal conduction is taken into account, is rigorously justified within the framework of classical solutions with small density and temperature variations. Moreover, we show that for a sufficiently small Mach number, the compressible MHD equations admit a smooth solution on the time interval where the smooth solution of the incompressible MHD equations exists. In addition, the low Mach number limit for the ideal MHD equations with small entropy variation is also investigated. The convergence rates are obtained in both cases.

Jiang, Song; Ju, Qiangchang; Li, Fucai

2012-05-01

119

Algorithm for loading shot noise microbunching in multi-dimensional, free-electron laser simulation codes  

SciTech Connect

We discuss the underlying reasoning behind and the details of the numerical algorithm used in the GINGER free-electron laser(FEL) simulation code to load the initial shot noise microbunching on the electron beam. In particular, we point out that there are some additional subtleties which must be followed for multi-dimensional codes which are not necessary for one-dimensional formulations. Moreover, requiring that the higher harmonics of the microbunching also be properly initialized with the correct statistics leads to additional complexities. We present some numerical results including the predicted incoherent, spontaneous emission as tests of the shot noise algorithm's correctness.

Fawley, William M.

2002-03-25

120

A generalized implicit algorithm for multi-dimensional particle-in-cell simulations in Cartesian geometry  

SciTech Connect

An implicit multi-dimensional particle-in-cell (PIC) code is developed to study the interaction of ultrashort pulse lasers with matter. The algorithm is based on current density decomposition and is only marginally more complicated compared to explicit PIC codes, but it completely eliminates grid heating and possesses good energy conserving properties with relaxed time step and grid resolution. This is demonstrated in a test case study, in which high-energy protons are generated from a thin carbon foil at solid density using linear and circular polarizations. The grid heating rate is estimated to be 1-10 eV/ps.

Petrov, G. M.; Davis, J. [Naval Research Laboratory, Plasma Physics Division, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

2011-07-15

121

MUlti-Dimensional Spline-Based Estimator (MUSE) for motion estimation: algorithm development and initial results.  

PubMed

Image registration and motion estimation play central roles in many fields, including RADAR, SONAR, light microscopy, and medical imaging. Because of its central significance, estimator accuracy, precision, and computational cost are of critical importance. We have previously presented a highly accurate, spline-based time delay estimator that directly determines sub-sample time delay estimates from sampled data. The algorithm uses cubic splines to produce a continuous representation of a reference signal and then computes an analytical matching function between this reference and a delayed signal. The location of the minima of this function yields estimates of the time delay. In this paper we describe the MUlti-dimensional Spline-based Estimator (MUSE) that allows accurate and precise estimation of multi-dimensional displacements/strain components from multi-dimensional data sets. We describe the mathematical formulation for two- and three-dimensional motion/strain estimation and present simulation results to assess the intrinsic bias and standard deviation of this algorithm and compare it to currently available multi-dimensional estimators. In 1000 noise-free simulations of ultrasound data we found that 2D MUSE exhibits maximum bias of 2.6 x 10(-4) samples in range and 2.2 x 10(-3) samples in azimuth (corresponding to 4.8 and 297 nm, respectively). The maximum simulated standard deviation of estimates in both dimensions was comparable at roughly 2.8 x 10(-3) samples (corresponding to 54 nm axially and 378 nm laterally). These results are between two and three orders of magnitude better than currently used 2D tracking methods. Simulation of performance in 3D yielded similar results to those observed in 2D. We also present experimental results obtained using 2D MUSE on data acquired by an Ultrasonix Sonix RP imaging system with an L14-5/38 linear array transducer operating at 6.6 MHz. While our validation of the algorithm was performed using ultrasound data, MUSE is broadly applicable across imaging applications. PMID:18807190

Viola, Francesco; Coe, Ryan L; Owen, Kevin; Guenther, Drake A; Walker, William F

2008-09-20

122

POLARIZED LINE FORMATION IN MULTI-DIMENSIONAL MEDIA. V. EFFECTS OF ANGLE-DEPENDENT PARTIAL FREQUENCY REDISTRIBUTION  

SciTech Connect

The solution of polarized radiative transfer equation with angle-dependent (AD) partial frequency redistribution (PRD) is a challenging problem. Modeling the observed, linearly polarized strong resonance lines in the solar spectrum often requires the solution of the AD line transfer problems in one-dimensional or multi-dimensional (multi-D) geometries. The purpose of this paper is to develop an understanding of the relative importance of the AD PRD effects and the multi-D transfer effects and particularly their combined influence on the line polarization. This would help in a quantitative analysis of the second solar spectrum (the linearly polarized spectrum of the Sun). We consider both non-magnetic and magnetic media. In this paper we reduce the Stokes vector transfer equation to a simpler form using a Fourier decomposition technique for multi-D media. A fast numerical method is also devised to solve the concerned multi-D transfer problem. The numerical results are presented for a two-dimensional medium with a moderate optical thickness (effectively thin) and are computed for a collisionless frequency redistribution. We show that the AD PRD effects are significant and cannot be ignored in a quantitative fine analysis of the line polarization. These effects are accentuated by the finite dimensionality of the medium (multi-D transfer). The presence of magnetic fields (Hanle effect) modifies the impact of these two effects to a considerable extent.

Anusha, L. S.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, 2nd Block, Bangalore 560 034 (India)

2012-02-10

123

Multiple time scales in survival analysis  

Microsoft Academic Search

In some problems in survival analysis there may be more than one plausible measure of time for each individual. For example mileage may be a better indication of the age of a car than months. This paper considers the possibility of combining two (or more) time scales measured on each individual into a single scale. A collapsibility condition is proposed

David Oakes

1995-01-01

124

The Power of Correlative Microscopy: Multi-modal, Multi-scale, Multi-dimensional  

PubMed Central

Correlative microscopy is a sophisticated approach that combines the capabilities of typically separate, but powerful microscopy platforms: often including, but not limited, to conventional light, confocal and super-resolution microscopy, atomic force microscopy, transmission and scanning electron microscopy, magnetic resonance imaging and micro/nanoCT (computed tomography). When targeting rare or specific events within large populations or tissues, correlative microscopy is increasingly being recognized as the method of choice. Furthermore, this multi-modal assimilation of technologies provides complementary and often unique information, such as internal and external spatial, structural, biochemical and biophysical details from the same targeted sample. The development of a continuous stream of cutting-edge applications, probes, preparation methodologies, hardware and software developments will enable realization of the full potential of correlative microscopy.

Caplan, Jeffrey; Niethammer, Marc; Taylor, Russell M.; Czymmek, Kirk J.

2011-01-01

125

Development of a MultiDimensional Scale for Measuring Food Tourist Motivations  

Microsoft Academic Search

Food in tourism is becoming an important subject to researchers in the field of tourism and food service. Food and its related tourist activities have been ascribed into a new category of tourism called food tourism in which the motivation for traveling is to obtain special experiences from food. However, limited attention has been paid to explore precisely what factors

Young H. Kim; Ben K. Goh; Jingxue Yuan

2010-01-01

126

Dimensional analysis of pore scale and field scale immiscible displacement  

Microsoft Academic Search

A basic re-examination of the traditional dimensional analysis of microscopic and macroscopic multiphase flow equations in porous media is presented. We introduce a ‘macroscopic capillary number’\\u000a$$\\\\overline {Ca}$$\\u000a which differs from the usual microscopic capillary number Ca in that it depends on length scale, type of porous medium and saturation history. The macroscopic capillary number\\u000a$$\\\\overline {Ca}$$\\u000a is defined as

R. Hilfer; P. E. Øren

1996-01-01

127

Dimensionality of hallucinatory predisposition: Confirmatory factor analysis of the Launay-Slade Hallucination Scale-revised in college students  

Microsoft Academic Search

Hallucinatory predisposition, as measured by the Launay-Slade Hallucination scale-revised (LSHS-R) (Bentall & Slade, 1985), is a multi- dimensional construct, although its factor structure is not yet well estab- lished. The purpose of this work was to analyze the dimensional structure of hallucinatory predisposition in nonclinical population. The sample comprised 807 young adults, 562 female (63.3%), with a mean age of

Eduardo Fonseca-Pedrero; Serafín Lemos-Giráldez; Mercedes Paino; Susana Sierra-Baigrie; Úrsula Villazón-García; María Paz; García-Portilla González; José Muñiz

2010-01-01

128

Ion-acoustic solitary waves and their multi-dimensional instability in a magnetized degenerate plasma  

SciTech Connect

A rigorous theoretical investigation has been made on Zakharov-Kuznetsov (ZK) equation of ion-acoustic (IA) solitary waves (SWs) and their multi-dimensional instability in a magnetized degenerate plasma which consists of inertialess electrons, inertial ions, negatively, and positively charged stationary heavy ions. The ZK equation is derived by the reductive perturbation method, and multi-dimensional instability of these solitary structures is also studied by the small-k (long wave-length plane wave) perturbation expansion technique. The effects of the external magnetic field are found to significantly modify the basic properties of small but finite-amplitude IA SWs. The external magnetic field and the propagation directions of both the nonlinear waves and their perturbation modes are found to play a very important role in changing the instability criterion and the growth rate of the unstable IA SWs. The basic features (viz., amplitude, width, instability, etc.) and the underlying physics of the IA SWs, which are relevant to space and laboratory plasma situations, are briefly discussed.

Haider, M. M. [Department of Physics, Mawlana Bhashani Science and Technology University, Santosh, Tangail 1902 (Bangladesh); Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh)

2012-10-15

129

Multi-dimensional NMR without coherence transfer: Minimizing losses in large systems  

PubMed Central

Most multi-dimensional solution NMR experiments connect one dimension to another using coherence transfer steps that involve evolution under scalar couplings. While experiments of this type have been a boon to biomolecular NMR the need to work on ever larger systems pushes the limits of these procedures. Spin relaxation during transfer periods for even the most efficient 15N–1H HSQC experiments can result in more than an order of magnitude loss in sensitivity for molecules in the 100 kDa range. A relatively unexploited approach to preventing signal loss is to avoid coherence transfer steps entirely. Here we describe a scheme for multi-dimensional NMR spectroscopy that relies on direct frequency encoding of a second dimension by multi-frequency decoupling during acquisition, a technique that we call MD-DIRECT. A substantial improvement in sensitivity of 15N–1H correlation spectra is illustrated with application to the 21 kDa ADP ribosylation factor (ARF) labeled with 15N in all alanine residues. Operation at 4 °C mimics observation of a 50 kDa protein at 35 °C.

Liu, Yizhou; Prestegard, James H.

2011-01-01

130

Multi-dimensional issues of the comparison of remotely sensed atmospheric composition data  

NASA Astrophysics Data System (ADS)

Quantitative comparison of atmospheric observations acquired by different measurement sys-tems and evaluation of modelling results with those observations often assume that the mea-sured information has negligible temporal and spatial resolution and that it concentrates around a single geolocation. This geolocation can be the monitoring station at which a ground-based spectrometer is operated, or the ground footprint of a nadir scanning satellite, or the tangent point of a limb scanning balloon or satellite. In reality, ground and satellite remote sensing provide a smoothed and discrete perception of the actual distribution and variability of at-mospheric species. The comparison of atmospheric composition data characterised by different smoothing and sampling properties poses significant challenges in the presence of large variabil-ity and gradients. This paper aims to increase awareness of important data comparison issues of a multi-dimensional nature. For this purpose, we adopt the concept of Observation Operators, widely used in chemical data assimilation. Observation Operators describe mathematically multi-dimensional aspects of the retrieved atmospheric information, e.g., its barycentre and spread. We discuss this application for major satellite measurement techniques and illustrate it through practical examples of satellite validation.

Vandenbussche, Sophie; Lambert, Jean-Christopher; de Clercq, Coralie; Spurr, Robert; von Clarmann, Thomas

131

Identifying associations between pig pathologies using a multi-dimensional machine learning methodology  

PubMed Central

Background Abattoir detected pathologies are of crucial importance to both pig production and food safety. Usually, more than one pathology coexist in a pig herd although it often remains unknown how these different pathologies interrelate to each other. Identification of the associations between different pathologies may facilitate an improved understanding of their underlying biological linkage, and support the veterinarians in encouraging control strategies aimed at reducing the prevalence of not just one, but two or more conditions simultaneously. Results Multi-dimensional machine learning methodology was used to identify associations between ten typical pathologies in 6485 batches of slaughtered finishing pigs, assisting the comprehension of their biological association. Pathologies potentially associated with septicaemia (e.g. pericarditis, peritonitis) appear interrelated, suggesting on-going bacterial challenges by pathogens such as Haemophilus parasuis and Streptococcus suis. Furthermore, hepatic scarring appears interrelated with both milk spot livers (Ascaris suum) and bacteria-related pathologies, suggesting a potential multi-pathogen nature for this pathology. Conclusions The application of novel multi-dimensional machine learning methodology provided new insights into how typical pig pathologies are potentially interrelated at batch level. The methodology presented is a powerful exploratory tool to generate hypotheses, applicable to a wide range of studies in veterinary research.

2012-01-01

132

Natural attenuation of chlorinated ethene compounds: model development and field-scale application at the Dover site  

Microsoft Academic Search

A multi-dimensional and multi-species reactive transport model was developed to aid in the analysis of natural attenuation design at chlorinated solvent sites. The model can simulate several simultaneously occurring attenuation processes including aerobic and anaerobic biological degradation processes. The developed model was applied to analyze field-scale transport and biodegradation processes occurring at the Area-6 site in Dover Air Force Base,

T. Prabhakar Clement; Christian D. Johnson; Yunwei Sun; Gary M. Klecka; Craig Bartlett

2000-01-01

133

A scaling analysis of ozone photochemistry  

Microsoft Academic Search

A scaling analysis has been used to capture the integrated behaviour of several photochemical mechanisms for a wide range of precursor concentrations and a variety of environmental conditions. The Buckingham Pi method of dimensional analysis was used to express the relevant variables in terms of dimensionless groups. These grouping show maximum ozone, initial NOx and initial VOC concentrations are made

B. Ainslie; D. G. Steyn

2006-01-01

134

Multi-dimensional instability of dust-acoustic solitary waves in a magnetized plasma with opposite polarity dust  

SciTech Connect

Dust-acoustic (DA) solitary structures and their multi-dimensional instability in a magnetized dusty plasma (containing inertial negatively and positively charged dust particles, and Boltzmann electrons and ions) have been theoretically investigated by the reductive perturbation method, and the small-k perturbation expansion technique. It has been found that the basic features (polarity, speed, height, thickness, etc.) of such DA solitary structures, and their multi-dimensional instability criterion or growth rate are significantly modified by the presence of opposite polarity dust particles and external magnetic field. The implications of our results in space and laboratory dusty plasma systems have been briefly discussed.

Akhter, T.; Hossain, M. M.; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)

2012-09-15

135

A parallel, implicit, multi-dimensional upwind, residual distribution method for the Navier-Stokes equations on unstructured grids  

Microsoft Academic Search

A multi-dimensional cell-vertex upwind discretization technique for the Navier-Strokes equations on unstructured grids is\\u000a presented. The grids are composed of linear triangles in two and linear tetrahedra in three space dimensions. The nonlinear\\u000a upwind schemes for the inviscid part can be viewed as a multi-dimensional generalization of the Roe-scheme, but also as a\\u000a special class of Petrov-Galerkin schemes. They share

E. van der Weide; H. Deconinck; E. Issman; G. Degrez

1999-01-01

136

Bayesian finite-size scaling analysis  

Microsoft Academic Search

The finite-size scaling analysis for phase transition phenomena is widely\\u000aused to determine the transition point and the universality class. As the\\u000amaximum entropy method for an analytic continuation of quantum Monte Carlo\\u000adata, we propose a Bayesian inference method for the finite-size scaling\\u000aanalysis. This method is based on a regression using a Gaussian process, which\\u000ahas been widely

Kenji Harada

2011-01-01

137

Benchmarking COTS Projects Using Data Envelopment Analysis  

Microsoft Academic Search

In Ernst & Young and Andersen Consulting, two of the “big five”, there is a continuous search for better methods to measure and compare project performance of multi-dimensional COTS software projects. We propose using Data Envelopment Analysis (DEA) with a Variable Returns to Scale (VRS) model. First, we discuss and illustrate this method by analyzing Albrecht-Gaffney's two-dimensional dataset. Next, we

Ingunn Myrtveit; Erik Stensrud

1999-01-01

138

Measurement of Low Level Explosives Reaction in Gauged Multi-Dimensional Steven Impact Tests  

NASA Astrophysics Data System (ADS)

The Steven Test was developed to determine relative impact sensitivity of metal encased solid high explosives and be amenable to two-dimensional modeling. Low level reaction thresholds occur at impact velocities below those required for shock initiation. To assist in understanding this test, multi-dimensional gauge techniques utilizing carbon foil and carbon resistor gauges were used to measure pressure and event times. Carbon resistor gauges indicated late time low level reactions 350 ms after projectile impact, creating 0.5-0.6 kb peak shocks centered in PBX 9501 explosives discs. Steven Test calculations based on ignition and growth criteria predict low level reactions occurring at 335 ms which agrees well with experimental data. Additional gauged experiments simulating the Steven Test have been performed and will be discussed. * This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National laboratory under contract No. W-7405-Eng-48.

Niles, A. M.; Forbes, J. W.; Tarver, C. M.; Chidester, S. K.; Garcia, F.; Greenwood, D. W.; Garza, R. G.

2001-06-01

139

Measurement of Low Level Explosives Reaction in Gauged Multi-dimensional Steven Impact Tests  

NASA Astrophysics Data System (ADS)

The Steven Test was developed to determine relative impact sensitivity of metal encased solid high explosives and also be amenable to two-dimensional modeling. Low level reaction thresholds occur at impact velocities below those required for shock initiation. To assist in understanding this test, multi-dimensional gauge techniques utilizing carbon foil and carbon resistor gauges were used to measure pressure and event times. Carbon resistor gauges indicated late time low level reactions 200-540 mus after projectile impact, creating 0.39-2.00 kb peak shocks centered in PBX 9501 explosives discs and a 0.60 kb peak shock in a LX-04 disk. Steven Test modeling results, based on ignition and growth criteria, are presented for two PBX 9501 scenarios: one with projectile impact velocity just under threshold (51 m/s) and one with projectile impact velocity just over threshold (55 m/s). Modeling results are presented and compared to experimental data.

Niles, A. M.; Garcia, F.; Greenwood, D. W.; Forbes, J. W.; Tarver, C. M.; Chidester, S. K.; Garza, R. G.; Swizter, L. L.

2002-07-01

140

Multi-dimensional fiber-optic radiation sensor for ocular proton therapy dosimetry  

NASA Astrophysics Data System (ADS)

In this study, we fabricated a multi-dimensional fiber-optic radiation sensor, which consists of organic scintillators, plastic optical fibers and a water phantom with a polymethyl methacrylate structure for the ocular proton therapy dosimetry. For the purpose of sensor characterization, we measured the spread out Bragg-peak of 120 MeV proton beam using a one-dimensional sensor array, which has 30 fiber-optic radiation sensors with a 1.5 mm interval. A uniform region of spread out Bragg-peak using the one-dimensional fiber-optic radiation sensor was obtained from 20 to 25 mm depth of a phantom. In addition, the Bragg-peak of 109 MeV proton beam was measured at the depth of 11.5 mm of a phantom using a two-dimensional sensor array, which has 10×3 sensor array with a 0.5 mm interval.

Jang, K. W.; Yoo, W. J.; Moon, J.; Han, K. T.; Park, B. G.; Shin, D.; Park, S.-Y.; Lee, B.

2012-12-01

141

Ionizing shocks in argon. Part II: Transient and multi-dimensional effects  

SciTech Connect

We extend the computations of ionizing shocks in argon to the unsteady and multi-dimensional, using a collisional-radiative model and a single-fluid, two-temperature formulation of the conservation equations. It is shown that the fluctuations of the shock structure observed in shock-tube experiments can be reproduced by the numerical simulations and explained on the basis of the coupling of the nonlinear kinetics of the collisional-radiative model with wave propagation within the induction zone. The mechanism is analogous to instabilities of detonation waves and also produces a cellular structure commonly observed in gaseous detonations. We suggest that detailed simulations of such unsteady phenomena can yield further information for the validation of nonequilibrium kinetics.

Kapper, M. G.; Cambier, J.-L. [Air Force Research Laboratory, Edwards AFB, CA 93524 (United States)

2011-06-01

142

Spherical harmonics method applied to the multi-dimensional radiation transfer  

NASA Astrophysics Data System (ADS)

The spectral radiation transfer equation in 2D axisymmetrical and 3D geometries is solved by the P1-approximation of the spherical harmonics and ray-tracing methods. Martian atmosphere and typical entry conditions are considered. Navier-Stokes equations coupled with the nonequilibrium vibrational excitation and finite rate chemistry describe thermodynamically and chemically nonequilibrium gas. The multi-group model is used to model optical properties of CO2-N2 mixture. The developed methodology of integration of the P1-approximation on unstructured grids and subsequent numerical solution allow us to reach reasonable agreement with the accurate ray-tracing method and drastically reduce the cost of solution of the radiation transfer equation in multi-dimensional geometries.

Andrienko, Daniil A.; Surzhikov, Sergey T.; Shang, Joseph S.

2013-10-01

143

Extending the Implicit Association Test (IAT): Assessing Consumer Attitudes Based on Multi-Dimensional Implicit Associations  

PubMed Central

Background The authors present a procedural extension of the popular Implicit Association Test (IAT; [1]) that allows for indirect measurement of attitudes on multiple dimensions (e.g., safe–unsafe; young–old; innovative–conventional, etc.) rather than on a single evaluative dimension only (e.g., good–bad). Methodology/Principal Findings In two within-subjects studies, attitudes toward three automobile brands were measured on six attribute dimensions. Emphasis was placed on evaluating the methodological appropriateness of the new procedure, providing strong evidence for its reliability, validity, and sensitivity. Conclusions/Significance This new procedure yields detailed information on the multifaceted nature of brand associations that can add up to a more abstract overall attitude. Just as the IAT, its multi-dimensional extension/application (dubbed md-IAT) is suited for reliably measuring attitudes consumers may not be consciously aware of, able to express, or willing to share with the researcher [2], [3].

Gattol, Valentin; Saaksjarvi, Maria; Carbon, Claus-Christian

2011-01-01

144

High-Level Waste Tanks Multi-Dimensional Contaminant Transport Model Development  

SciTech Connect

A suite of multi-dimensional computer models was developed to analyze the transport of residual contamination from high-level waste tanks through the subsurface to seeplines. Cases analyzed ranged from all the tanks in the F- and H-tank farms for an overall look; to the Tank 17-20 4-pack to study plume interaction; to individual tanks, such as Tank 17 and 20 for comparison with one-dimensional and modeling. The main purpose of this work was to develop and test the models, so only two relatively conservative contaminants were examined, Tc-99 and I-129. More complex analyses, such as solubility-limited species and radionuclides that head a decay chain were not addressed in this study.

Collard, L.B.

1999-11-15

145

Multi-dimensional mass spectrometry-based shotgun lipidomics and novel strategies for lipidomic analyses.  

PubMed

Since our last comprehensive review on multi-dimensional mass spectrometry-based shotgun lipidomics (Mass Spectrom. Rev. 24 (2005), 367), many new developments in the field of lipidomics have occurred. These developments include new strategies and refinements for shotgun lipidomic approaches that use direct infusion, including novel fragmentation strategies, identification of multiple new informative dimensions for mass spectrometric interrogation, and the development of new bioinformatic approaches for enhanced identification and quantitation of the individual molecular constituents that comprise each cell's lipidome. Concurrently, advances in liquid chromatography-based platforms and novel strategies for quantitative matrix-assisted laser desorption/ionization mass spectrometry for lipidomic analyses have been developed. Through the synergistic use of this repertoire of new mass spectrometric approaches, the power and scope of lipidomics has been greatly expanded to accelerate progress toward the comprehensive understanding of the pleiotropic roles of lipids in biological systems. PMID:21755525

Han, Xianlin; Yang, Kui; Gross, Richard W

2011-07-13

146

Scale-specific multifractal medical image analysis.  

PubMed

Fractal geometry has been applied widely in the analysis of medical images to characterize the irregular complex tissue structures that do not lend themselves to straightforward analysis with traditional Euclidean geometry. In this study, we treat the nonfractal behaviour of medical images over large-scale ranges by considering their box-counting fractal dimension as a scale-dependent parameter rather than a single number. We describe this approach in the context of the more generalized Rényi entropy, in which we can also compute the information and correlation dimensions of images. In addition, we describe and validate a computational improvement to box-counting fractal analysis. This improvement is based on integral images, which allows the speedup of any box-counting or similar fractal analysis algorithm, including estimation of scale-dependent dimensions. Finally, we applied our technique to images of invasive breast cancer tissue from 157 patients to show a relationship between the fractal analysis of these images over certain scale ranges and pathologic tumour grade (a standard prognosticator for breast cancer). Our approach is general and can be applied to any medical imaging application in which the complexity of pathological image structures may have clinical value. PMID:24023588

Braverman, Boris; Tambasco, Mauro

2013-08-19

147

Reduced Dynamic Time Warping for Handwriting Recognition Based on Multi dimensional Time Series of a Novel Pen Device  

Microsoft Academic Search

The purpose of this paper is to present a Dynamic Time Warping technique which reduces significantly the data processing time and memory size of multi-dimensional time series sampled by the biometric smart pen device BiSP. The acquisition device is a novel ballpoint pen equipped with a diversity of sensors for monitoring the kinematics and dynamics of handwriting movement. The DTW

Muzaffar Bashir; Jürgen Kempf

2008-01-01

148

MAI (Multi-Dimensional Activity Based Integrated Approach): A Strategy for Cognitive Development of the Learners at the Elementary Stage  

ERIC Educational Resources Information Center

|Cognitive development of the learners is the prime task of each and every stage of our school education and its importance especially in elementary state is quite worth mentioning. Present study investigated the effectiveness of a new and innovative strategy (i.e., MAI (multi-dimensional activity based integrated approach)) for the development of…

Basantia, Tapan Kumar; Panda, B. N.; Sahoo, Dukhabandhu

2012-01-01

149

Stepwise superposition approach for the analytical solutions of multi-dimensional contaminant transport in finite- and semi-infinite aquifers.  

PubMed

Analytical solutions of contaminant transport in multi-dimensional media are significant for theoretical and practical purposes. However, due to the problems for which the solutions are sought which are complex in most of the cases, most available analytical solutions in multi-dimensional media are not given in their closed forms. Integrals are often included in the solution expressions, which may limit the practitioners to use the solutions. In addition, available multi-dimensional solutions for the third-type sources in bounded media are fairly limited. In this paper, a stepwise superposition approach for obtaining approximate multi-dimensional transport solutions is developed. The approach is based on the condition that the one-dimensional solution along the flow direction is known. The solutions are expressed in their closed forms without integrals. The transport media to the solutions are flexible and can be finite, semi-infinite, or infinite in the transverse directions. The solutions subject to the first- and third-type boundary conditions at the inlet with a distributed source over the domain are obtained. The integrals in some known solutions can also be evaluated by the approach if they can be derived to include known longitudinal integrals with respect to time. The accuracy and efficiency of the solutions proposed in this paper are verified through test problems and calculation examples. PMID:21665320

Wang, Hongtao; Liu, Jinwen; Zhao, Yan; Lu, Wenjing; Wu, Huayong

2011-05-23

150

Accelerated Multi-Dimensional RF Pulse Design for Parallel Transmission Using Concurrent Computation on Multiple Graphics Processing Units  

PubMed Central

Multi-dimensional RF pulses are of current interest due to their promise for improving high field imaging as well as for optimizing parallel transmission methods. One major drawback is that the computation time of numerically designed multi-dimensional RF pulses increases rapidly with their resolution and number of transmitters. This is critical because the construction of multi-dimensional RF pulses often needs to be in real time. The use of graphics processing units for computations is a recent approach for accelerating image reconstruction applications. We propose the use of graphics processing units for the design of multi-dimensional RF pulses including the utilization of parallel transmitters. Using a desktop computer with four NVIDIA Tesla C1060 computing processors, we found acceleration factors on the order of twenty for standard eight-transmitter 2D spiral RF pulses with a 64 × 64 excitation resolution and a ten-microsecond dwell time. We also show that even greater acceleration factors can be achieved for more complex RF pulses.

Deng, Weiran; Yang, Cungeng; Stenger, V. Andrew

2010-01-01

151

Application of the MultiDimensional Positive Definite Advection Transport Algorithm (MPDATA) to Environmental Modeling on Adaptive Unstructured Grids  

Microsoft Academic Search

Twenty years ago, the multi-dimensional, positive definite, advection transport algorithm was introduced by Smolarkiewicz. Over the two decades since, it has been applied countless times to numerous problems, however almost always on rectilinear grids. One of the few exceptions is the Operational Multiscale Environment model with Grid Adaptivity (OMEGA), an atmospheric simulation system originally designed to simulate atmospheric dispersion in

N. AHMAD; DAVID P. BACON; MARY S. HALL; ANANTHAKRISHNA SARMA

152

Semiquantal molecular dynamics simulations of hydrogen-bond dynamics in liquid water using multi-dimensional Gaussian wave packets  

NASA Astrophysics Data System (ADS)

A semiquantal (SQ) molecular dynamics (MD) simulation method based on an extended Hamiltonian formulation has been developed using multi-dimensional thawed Gaussian wave packets (WPs), and applied to an analysis of hydrogen-bond (H-bond) dynamics in liquid water. A set of Hamilton's equations of motion in an extended phase space, which includes variance-covariance matrix elements as auxiliary coordinates representing anisotropic delocalization of the WPs, is derived from the time-dependent variational principle. The present theory allows us to perform real-time and real-space SQMD simulations and analyze nuclear quantum effects on dynamics in large molecular systems in terms of anisotropic fluctuations of the WPs. Introducing the Liouville operator formalism in the extended phase space, we have also developed an explicit symplectic algorithm for the numerical integration, which can provide greater stability in the long-time SQMD simulations. The application of the present theory to H-bond dynamics in liquid water is carried out under a single-particle approximation in which the variance-covariance matrix and the corresponding canonically conjugate matrix are reduced to block-diagonal structures by neglecting the interparticle correlations. As a result, it is found that the anisotropy of the WPs is indispensable for reproducing the disordered H-bond network compared to the classical counterpart with the use of the potential model providing competing quantum effects between intra- and intermolecular zero-point fluctuations. In addition, the significant WP delocalization along the out-of-plane direction of the jumping hydrogen atom associated with the concerted breaking and forming of H-bonds has been detected in the H-bond exchange mechanism. The relevance of the dynamical WP broadening to the relaxation of H-bond number fluctuations has also been discussed. The present SQ method provides the novel framework for investigating nuclear quantum dynamics in the many-body molecular systems in which the local anisotropic fluctuations of nuclear WPs play an essential role.

Ono, Junichi; Ando, Koji

2012-11-01

153

Effects of changing scale on landscape pattern analysis: scaling relations  

Microsoft Academic Search

Landscape pattern is spatially correlated and scale-dependent. Thus, understanding landscape structure and functioning requires\\u000a multiscale information, and scaling functions are the most precise and concise way of quantifying multiscale characteristics\\u000a explicitly. The major objective of this study was to explore if there are any scaling relations for landscape pattern when\\u000a it is measured over a range of scales (grain size

Jianguo Wu

2004-01-01

154

A scaling analysis of ozone photochemistry  

NASA Astrophysics Data System (ADS)

A scaling analysis has been used to capture the integrated behaviour of several photochemical mechanisms for a wide range of precursor concentrations and a variety of environmental conditions. The Buckingham Pi method of dimensional analysis was used to express the relevant variables in terms of dimensionless groups. These grouping show maximum ozone, initial NOx and initial VOC concentrations are made non-dimensional by the average NO2 photolysis rate (jav) and the rate constant for the NO-O3 titration reaction (kNO); temperature by the NO-O3 activation energy (ENO) and Boltzmann constant (k) and total irradiation time by the cumulative jav?t photolysis rate. The analysis shows dimensionless maximum ozone concentration can be described by a product of powers of dimensionless initial NOx concentration, dimensionless temperature, and a similarity curve directly dependent on the ratio of initial VOC to NOx concentration and implicitly dependent on the cumulative NO2 photolysis rate. When Weibull transformed, the similarity relationship shows a scaling break with dimensionless model output clustering onto two straight line segments, parameterized using four variables: two describing the slopes of the line segments and two giving the location of their intersection. A fifth parameter is used to normalize the model output. The scaling analysis, similarity curve and parameterization appear to be independent of the details of the chemical mechanism, hold for a variety of VOC species and mixtures and a wide range of temperatures and actinic fluxes.

Ainslie, B.; Steyn, D. G.

2006-09-01

155

Multiple-scale analysis of quantum systems  

SciTech Connect

Conventional weak-coupling Rayleigh-Schr{umlt o}dinger perturbation theory suffers from problems that arise from resonant coupling of successive orders in the perturbation series. Multiple-scale analysis, a powerful and sophisticated perturbative method that quantitatively analyzes characteristic physical behaviors occurring on various length or time scales, avoids such problems by implicitly performing an infinite resummation of the conventional perturbation series. Multiple-scale perturbation theory provides a good description of the classical anharmonic oscillator. Here, it is extended to study (1) the Heisenberg operator equations of motion and (2) the Schr{umlt o}dinger equation for the quantum anharmonic oscillator. In the former case, it leads to a system of coupled operator differential equations, which is solved exactly. The solution provides an operator mass renormalization of the theory. In the latter case, multiple-scale analysis elucidates the connection between weak-coupling perturbative and semiclassical nonperturbative aspects of the wave function. {copyright} {ital 1996 The American Physical Society.}

Bender, C.M.; Bettencourt, L.M. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

1996-12-01

156

A SECOND-ORDER GODUNOV METHOD FOR MULTI-DIMENSIONAL RELATIVISTIC MAGNETOHYDRODYNAMICS  

SciTech Connect

We describe a new Godunov algorithm for relativistic magnetohydrodynamics (RMHD) that combines a simple, unsplit second-order accurate integrator with the constrained transport (CT) method for enforcing the solenoidal constraint on the magnetic field. A variety of approximate Riemann solvers are implemented to compute the fluxes of the conserved variables. The methods are tested with a comprehensive suite of multi-dimensional problems. These tests have helped us develop a hierarchy of correction steps that are applied when the integration algorithm predicts unphysical states due to errors in the fluxes, or errors in the inversion between conserved and primitive variables. Although used exceedingly rarely, these corrections dramatically improve the stability of the algorithm. We present preliminary results from the application of these algorithms to two problems in RMHD: the propagation of supersonic magnetized jets and the amplification of magnetic field by turbulence driven by the relativistic Kelvin-Helmholtz instability (KHI). Both of these applications reveal important differences between the results computed with Riemann solvers that adopt different approximations for the fluxes. For example, we show that the use of Riemann solvers that include both contact and rotational discontinuities can increase the strength of the magnetic field within the cocoon by a factor of 10 in simulations of RMHD jets and can increase the spectral resolution of three-dimensional RMHD turbulence driven by the KHI by a factor of two. This increase in accuracy far outweighs the associated increase in computational cost. Our RMHD scheme is publicly available as part of the Athena code.

Beckwith, Kris [JILA, University of Colorado at Boulder, 440 UCB Boulder, CO 80301 (United States); Stone, James M., E-mail: kris.beckwith@jila.colorado.edu, E-mail: jstone@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2011-03-15

157

Operationalising the Sustainable Knowledge Society Concept through a Multi-dimensional Scorecard  

NASA Astrophysics Data System (ADS)

Since the early 21st Century, building a Knowledge Society represents an aspiration not only for the developed countries, but for the developing ones too. There is an increasing concern worldwide for rendering this process manageable towards a sustainable, equitable and ethically sound societal system. As proper management, including at the societal level, requires both wisdom and measurement, the operationalisation of the Knowledge Society concept encompasses a qualitative side, related to vision-building, and a quantitative one, pertaining to designing and using dedicated metrics. The endeavour of enabling policy-makers mapping, steering and monitoring the sustainable development of the Knowledge Society at national level, in a world increasingly based on creativity, learning and open communication, led researchers to devising a wide range of composite indexes. However, as such indexes are generated through weighting and aggregation, their usefulness is limited to retrospectively assessing and comparing levels and states already attained; therefore, to better serve policy-making purposes, composite indexes should be complemented by other instruments. Complexification, inspired by the systemic paradigm, allows obtaining "rich pictures" of the Knowledge Society; to this end, a multi-dimensional scorecard of the Knowledge Society development is hereby suggested, that seeks a more contextual orientation towards sustainability. It is assumed that, in the case of the Knowledge Society, the sustainability condition goes well beyond the "greening" desideratum and should be of a higher order, relying upon the conversion of natural and productive life-cycles into virtuous circles of self-sustainability.

Dragomirescu, Horatiu; Sharma, Ravi S.

158

Mean-square stability of second-order Runge-Kutta methods for multi-dimensional linear stochastic differential systems  

NASA Astrophysics Data System (ADS)

In this paper, the mean-square stability of second-order Runge-Kutta schemes for multi-dimensional linear stochastic differential systems is studied. Motivated by the work of Tocino [Mean-square stability of second-order Runge-Kutta methods for stochastic differential equations, J. Comput. Appl. Math. 175 (2005) 355-367] and Saito and Mitsui [Mean-square stability of numerical schemes for stochastic differential systems, in: International Conference on SCIentific Computation and Differential Equations, July 29-August 3 2001, Vancouver, British Columbia, Canada] we investigate the mean-square stability of second-order Runge-Kutta schemes for multi-dimensional linear stochastic differential systems with one multiplicative noise. Stability criteria are established and numerical examples that confirm the theoretical results are also presented.

Rathinasamy, A.; Balachandran, K.

2008-09-01

159

A high-order finite volume method for systems of conservation laws—Multi-dimensional Optimal Order Detection (MOOD)  

NASA Astrophysics Data System (ADS)

In this paper, we investigate an original way to deal with the problems generated by the limitation process of high-order finite volume methods based on polynomial reconstructions. Multi-dimensional Optimal Order Detection (MOOD) breaks away from classical limitations employed in high-order methods. The proposed method consists of detecting problematic situations after each time update of the solution and of reducing the local polynomial degree before recomputing the solution. As multi-dimensional MUSCL methods, the concept is simple and independent of mesh structure. Moreover MOOD is able to take physical constraints such as density and pressure positivity into account through an “a posteriori” detection. Numerical results on classical and demanding test cases for advection and Euler system are presented on quadrangular meshes to support the promising potential of this approach.

Clain, S.; Diot, S.; Loubère, R.

2011-05-01

160

Conceptualising the perceived service quality of public utility services: A multi-level, multi-dimensional model  

Microsoft Academic Search

Based on the data relevant to four public utility services (water, natural gas, electricity and thermoelectricity) collected by a personally administered on-site survey, the authors develop a model to assess the perceived service quality of public utility services. In the model, the perceived service quality of public utility services has a multi-level, multi-dimensional structure with three primary dimensions: outcome, environment

Changhong Bai; Fujun Lai; Ye Chen; Joe Hutchinson

2008-01-01

161

Overview of NASA Multi-Dimensional Stirling Convertor Code Development and Validation Effort  

NASA Astrophysics Data System (ADS)

A NASA grant has been awarded to Cleveland State University (CSU) to develop a multi-dimensional (multi-D) Stirling computer code with the goals of improving loss predictions and identifying component areas for improvements. The University of Minnesota (UMN) and Gedeon Associates are teamed with CSU. Development of test rigs at UMN and CSU and validation of the code against test data are part of the effort. The one-dimensional (1-D) Stirling codes used for design and performance prediction do not rigorously model regions of the working space where abrupt changes in flow area occur (such as manifolds and other transitions between components). Certain hardware experiences have demonstrated large performance gains by varying manifolds and heat exchanger designs to improve flow distributions in the heat exchangers. 1-D codes were not able to predict these performance gains. An accurate multi-D code should improve understanding of the effects of area changes along the main flow axis, sensitivity of performance to slight changes in internal geometry, and, in general, the understanding of various internal thermodynamic losses. The commercial CFD-ACE code has been chosen for development of the multi-D code. This 2-D/3-D code has highly developed pre- and post-processors, and moving boundary capability. Preliminary attempts at validation of CFD-ACE models of MIT gas spring and ``two space'' test rigs were encouraging. Also, CSU's simulations of the UMN oscillating-flow rig compare well with flow visualization results from UMN. A complementary Department of Energy (DOE) Regenerator Research effort is aiding in development of regenerator matrix models that will be used in the multi-D Stirling code. This paper reports on the progress and challenges of this multi-D code development effort.

Tew, Roy C.; Cairelli, James E.; Ibrahim, Mounir B.; Simon, Terrence W.; Gedeon, David

2003-01-01

162

Overview of NASA Multi-Dimensional Stirling Convertor Code Development and Validation Effort  

NASA Astrophysics Data System (ADS)

A NASA grant has been awarded to Cleveland State University (CSU) to develop a multi-dimensional (multi-D) Stirling computer code with the goals of improving loss predictions and identifying component areas for improvements. The University of Minnesota (UMN) and Gedeon Associates are teamed with CSU. Development of test rigs at UMN and CSU and validation of the code against test data are part of the effort. The one-dimensional (1-D) Stirling codes used for design and performance prediction do not rigorously model regions of the working space where abrupt changes in flow area occur (such as manifolds and other transitions between components). Certain hardware experiences have demonstrated large performance gains by varying manifolds and heat exchanger designs to improve flow distributions in the heat exchangers. 1-D codes were not able to predict these performance gains. An accurate multi-D code should improve understanding of the effects of area changes along the main flow axis, sensitivity of performance to slight changes in internal geometry, and, in general, the understanding of various internal thermodynamic losses. The commercial CFD-ACE code has been chosen for development of the multi-D code. This 2-D/3-D code has highly developed pre- and post-processors, and moving boundary capability. Preliminary attempts at validation of CFD-ACE models of MIT gas spring and "two space" test rigs were encouraging. Also, CSU's simulations of the UMN oscillating-flow fig compare well with flow visualization results from UMN. A complementary Department of Energy (DOE) Regenerator Research effort is aiding in development of regenerator matrix models that will be used in the multi-D Stirling code. This paper reports on the progress and challenges of this

Tew, Roy C.; Cairelli, James E.; Ibrahim, Mounir B.; Simon, Terrence W.; Gedeon, David

2002-12-01

163

POLARIZED LINE FORMATION IN MULTI-DIMENSIONAL MEDIA. III. HANLE EFFECT WITH PARTIAL FREQUENCY REDISTRIBUTION  

SciTech Connect

In two previous papers, we solved the polarized radiative transfer (RT) equation in multi-dimensional (multi-D) geometries with partial frequency redistribution as the scattering mechanism. We assumed Rayleigh scattering as the only source of linear polarization (Q/I, U/I) in both these papers. In this paper, we extend these previous works to include the effect of weak oriented magnetic fields (Hanle effect) on line scattering. We generalize the technique of Stokes vector decomposition in terms of the irreducible spherical tensors T{sup K}{sub Q}, developed by Anusha and Nagendra, to the case of RT with Hanle effect. A fast iterative method of solution (based on the Stabilized Preconditioned Bi-Conjugate-Gradient technique), developed by Anusha et al., is now generalized to the case of RT in magnetized three-dimensional media. We use the efficient short-characteristics formal solution method for multi-D media, generalized appropriately to the present context. The main results of this paper are the following: (1) a comparison of emergent (I, Q/I, U/I) profiles formed in one-dimensional (1D) media, with the corresponding emergent, spatially averaged profiles formed in multi-D media, shows that in the spatially resolved structures, the assumption of 1D may lead to large errors in linear polarization, especially in the line wings. (2) The multi-D RT in semi-infinite non-magnetic media causes a strong spatial variation of the emergent (Q/I, U/I) profiles, which is more pronounced in the line wings. (3) The presence of a weak magnetic field modifies the spatial variation of the emergent (Q/I, U/I) profiles in the line core, by producing significant changes in their magnitudes.

Anusha, L. S.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, 2nd Block, Bangalore 560 034 (India)

2011-09-01

164

Polarized Line Formation in Multi-dimensional Media. III. Hanle Effect with Partial Frequency Redistribution  

NASA Astrophysics Data System (ADS)

In two previous papers, we solved the polarized radiative transfer (RT) equation in multi-dimensional (multi-D) geometries with partial frequency redistribution as the scattering mechanism. We assumed Rayleigh scattering as the only source of linear polarization (Q/I, U/I) in both these papers. In this paper, we extend these previous works to include the effect of weak oriented magnetic fields (Hanle effect) on line scattering. We generalize the technique of Stokes vector decomposition in terms of the irreducible spherical tensors {T}^K_Q, developed by Anusha & Nagendra, to the case of RT with Hanle effect. A fast iterative method of solution (based on the Stabilized Preconditioned Bi-Conjugate-Gradient technique), developed by Anusha et al., is now generalized to the case of RT in magnetized three-dimensional media. We use the efficient short-characteristics formal solution method for multi-D media, generalized appropriately to the present context. The main results of this paper are the following: (1) a comparison of emergent (I, Q/I, U/I) profiles formed in one-dimensional (1D) media, with the corresponding emergent, spatially averaged profiles formed in multi-D media, shows that in the spatially resolved structures, the assumption of 1D may lead to large errors in linear polarization, especially in the line wings. (2) The multi-D RT in semi-infinite non-magnetic media causes a strong spatial variation of the emergent (Q/I, U/I) profiles, which is more pronounced in the line wings. (3) The presence of a weak magnetic field modifies the spatial variation of the emergent (Q/I, U/I) profiles in the line core, by producing significant changes in their magnitudes.

Anusha, L. S.; Nagendra, K. N.

2011-09-01

165

Semiquantal molecular dynamics simulations of hydrogen-bond dynamics in liquid water using multi-dimensional Gaussian wave packets.  

PubMed

A semiquantal (SQ) molecular dynamics (MD) simulation method based on an extended Hamiltonian formulation has been developed using multi-dimensional thawed gaussian wave packets (WPs), and applied to an analysis of hydrogen-bond (H-bond) dynamics in liquid water. A set of Hamilton's equations of motion in an extended phase space, which includes variance-covariance matrix elements as auxiliary coordinates representing anisotropic delocalization of the WPs, is derived from the time-dependent variational principle. The present theory allows us to perform real-time and real-space SQMD simulations and analyze nuclear quantum effects on dynamics in large molecular systems in terms of anisotropic fluctuations of the WPs. Introducing the Liouville operator formalism in the extended phase space, we have also developed an explicit symplectic algorithm for the numerical integration, which can provide greater stability in the long-time SQMD simulations. The application of the present theory to H-bond dynamics in liquid water is carried out under a single-particle approximation in which the variance-covariance matrix and the corresponding canonically conjugate matrix are reduced to block-diagonal structures by neglecting the interparticle correlations. As a result, it is found that the anisotropy of the WPs is indispensable for reproducing the disordered H-bond network compared to the classical counterpart with the use of the potential model providing competing quantum effects between intra- and intermolecular zero-point fluctuations. In addition, the significant WP delocalization along the out-of-plane direction of the jumping hydrogen atom associated with the concerted breaking and forming of H-bonds has been detected in the H-bond exchange mechanism. The relevance of the dynamical WP broadening to the relaxation of H-bond number fluctuations has also been discussed. The present SQ method provides the novel framework for investigating nuclear quantum dynamics in the many-body molecular systems in which the local anisotropic fluctuations of nuclear WPs play an essential role. PMID:23145735

Ono, Junichi; Ando, Koji

2012-11-01

166

Stream Cube: An Architecture for MultiDimensional Analysis of Data Streams  

Microsoft Academic Search

Real-time surveillance systems, telecommunication systems, and other dynamic environments often generate tremendous (potentially infinite) volume of stream data: the volume is too huge to be scanned multiple times. Much of such data resides at rather low level of abstraction, whereas most analysts are interested in relatively high-level dynamic changes (such as trends and outliers). To discover such high-level characteristics, one

Jiawei Han; Yixin Chen; Guozhu Dong; Jian Pei; Benjamin W. Wah; Jianyong Wang; Y. Dora Cai

2005-01-01

167

Scaling analysis of coral reef systems: an approach to problems of scale  

Microsoft Academic Search

Dimensional analysis and scaling are related, semi-formal procedures for capturing the essential process(es) controlling the behaviour of a complex system, and for describing the functional relationships between them. The techniques involve the parameterization of natural processes, the identification of the temporal and spatial scales of variation of processes, and the evaluation of potential interactions between processes referenced to those scales

Bruce G. Hatcher; Jorg Imberger; Stephen V. Smith

1987-01-01

168

Uncertainty analysis of basin scale compaction processes  

NASA Astrophysics Data System (ADS)

The dynamic evolution of porosity distribution in sedimentary basins has been typically interpreted by assuming that mechanical compaction is the dominant process. While mechanical compaction is particularly relevant during the early burial phase and has been often assumed to play a key role in the diagenesis even at the largest depths, temperature-activated geochemical compaction has been recognized as a major component driving the evolution of the basin characteristics and of the compaction process at least within the deepest layers. As a consequence, modeling basin evolution requires solving a coupled system involving partial differential equations and algebraic relationships between state variables. In this framework, quartz cementation and smectite-illite transformation are recognized to be the most relevant processes affecting sedimentary basins evolution. Spatial and temporal scales of basin evolution are intrinsically very large and it is often difficult to provide reliable estimates for the parameters included in the selected geochemical and compaction models. In this study we focus on the effects that the coupling between the quartz cementation process and mechanical compaction have on the distribution of porosity, pressure and temperature in the evolving sedimentary basin in the presence of uncertain model parameters and boundary conditions. We quantify uncertainty associated with the system state variables by means of a Global Sensitivity Analysis (GSA). The methodology is framed within the context of a generalized Polynomial Chaos Expansion (GPCE) approximation of a basin-scale evolution scenario. Sparse grids sampling techniques are employed to improve the computational efficiency of the methodology. The theoretical and computational framework adopted allows an efficient computation of the variance-based Sobol indices, exploiting a polynomial interpolation over the sparse grid collocation points. An additional advantage of the GPCE is that it yields a surrogate model of the system behavior. This can be exploited within the context of uncertainty propagation studies, e.g., based on numerical Monte Carlo simulations. It allows observing the space-time evolution of the probability density distribution (and its statistical moments) of target problem variables. The approach is illustrated through a one-dimensional example involving the process of quartz cementation in sandstones and the resulting effects on the dynamics of porosity, temperature and pressure.

Formaggia, L.; Guadagnini, A.; Imperiali, I.; Lever, V.; Porta, G.; Riva, M.; Scotti, A.; Tamellini, L.

2012-04-01

169

Multi-dimensional, mesoscopic Monte Carlo simulations of inhomogeneous reaction-drift-diffusion systems on graphics-processing units.  

PubMed

For many biological applications, a macroscopic (deterministic) treatment of reaction-drift-diffusion systems is insufficient. Instead, one has to properly handle the stochastic nature of the problem and generate true sample paths of the underlying probability distribution. Unfortunately, stochastic algorithms are computationally expensive and, in most cases, the large number of participating particles renders the relevant parameter regimes inaccessible. In an attempt to address this problem we present a genuine stochastic, multi-dimensional algorithm that solves the inhomogeneous, non-linear, drift-diffusion problem on a mesoscopic level. Our method improves on existing implementations in being multi-dimensional and handling inhomogeneous drift and diffusion. The algorithm is well suited for an implementation on data-parallel hardware architectures such as general-purpose graphics processing units (GPUs). We integrate the method into an operator-splitting approach that decouples chemical reactions from the spatial evolution. We demonstrate the validity and applicability of our algorithm with a comprehensive suite of standard test problems that also serve to quantify the numerical accuracy of the method. We provide a freely available, fully functional GPU implementation. Integration into Inchman, a user-friendly web service, that allows researchers to perform parallel simulations of reaction-drift-diffusion systems on GPU clusters is underway. PMID:22506001

Vigelius, Matthias; Meyer, Bernd

2012-04-10

170

Statistical Approach and Benchmarking for Modeling of Multi-dimensional Behavior in TRISO-coated Fuel Particles  

SciTech Connect

The fundamental design for a gas-cooled reactor relies on the behavior of the coated particle fuel. The coating layers, termed the TRISO coating, act as a mini-pressure vessel that retains fission products. Results of US irradiation experiments show that many more fuel particles have failed than can be attributed to one-dimensional pressure vessel failures alone. Post-irradiation examinations indicate that multi-dimensional effects, such as the presence of irradiation-induced shrinkage cracks in the inner pyrolytic carbon layer, contribute to these failures. To address these effects, the methods of prior one-dimensional models are expanded to capture the stress intensification associated with multi-dimensional behavior. An approximation of the stress levels enables the treatment of statistical variations in numerous design parameters and Monte Carlo sampling over a large number of particles. The approach is shown to make reasonable predictions when used to calculate failure probabilities for irradiation experiments of the New Production – Modular High Temperature Gas Cooled Reactor Program.

Miller, Gregory Kent; Petti, David Andrew; Maki, John Thomas; Varacalle, Dominic Joseph

2003-04-01

171

Scale space methods for climate model analysis  

NASA Astrophysics Data System (ADS)

In this paper, we introduce methods for evaluating climate model performance across spatial scales. These techniques are based on the "scale space" framework widely used in the image processing and computer vision communities. We discuss why the diffusion equation on the sphere provides a particularly attractive means of smoothing two-dimensional maps of global climate data. We establish that no structure is introduced into a map as an artifact of the smoothing procedure. This allows for the comparison of models and observations at multiple scales. As a test case for these methods, we compare the ability of high- and low-resolution versions of the Community Climate System Model (CCSM) to simulate the seasonal climatologies of surface air temperature (TAS), sea level pressure (PSL), and total precipitation rate (PR). For TAS, we find that the high-resolution model is better able to capture the boreal summer (JJA) climatological pattern at fine scales, although there is no such improvement in winter (DJF). We find the performances of the high- and low-resolution models to be similarly capable of capturing the summertime sea level pressure climatology at all scales. However, the high-resolution model PSL climatology is degraded for DJF, especially at larger scales. For both JJA and DJF precipitation climatologies, we find larger precipitation errors in the high-resolution model at the finest scales; however, performance at larger scales is improved.

Marvel, K.; Ivanova, D.; Taylor, K. E.

2013-06-01

172

Scientific design of Purdue University Multi-Dimensional Integral Test Assembly (PUMA) for GE SBWR  

SciTech Connect

The scaled facility design was based on the three level scaling method; the first level is based on the well established approach obtained from the integral response function, namely integral scaling. This level insures that the stead-state as well as dynamic characteristics of the loops are scaled properly. The second level scaling is for the boundary flow of mass and energy between components; this insures that the flow and inventory are scaled correctly. The third level is focused on key local phenomena and constitutive relations. The facility has 1/4 height and 1/100 area ratio scaling; this corresponds to the volume scale of 1/400. Power scaling is 1/200 based on the integral scaling. The time will run twice faster in the model as predicted by the present scaling method. PUMA is scaled for full pressure and is intended to operate at and below 150 psia following scram. The facility models all the major components of SBWR (Simplified Boiling Water Reactor), safety and non-safety systems of importance to the transients. The model component designs and detailed instrumentations are presented in this report.

Ishii, M.; Ravankar, S.T.; Dowlati, R. [Purdue Univ., Lafayette, IN (United States). School of Nuclear Engineering] [and others

1996-04-01

173

Multi-dimensional mass spectrometry-based shotgun lipidomics and the altered lipids at the mild cognitive impairment stage of Alzheimer's disease  

PubMed Central

Multi-dimensional mass spectrometry-based shotgun lipidomics (MDMS-SL) is a well-developed technology for global lipid analysis, which identifies and quantifies individual lipid molecular species directly from lipid extracts of biological samples. By using this technology, we have revealed three marked changes of lipids in brain samples of subjects with mild cognitive impairment of Alzheimer’s disease including sulfatides, ceramides, and plasmalogens. Further studies using MDMS-SL lead us to the identification of the potential biochemical mechanisms responsible for the altered lipids at the disease state, which are thoroughly discussed in this mini review. Specifically, in studies to identify the causes responsible for sulfatide depletion at the mild cognitive impairment stage of Alzheimer’s disease, we have found that apolipoprotein E is associated with sulfatide transport and mediates sulfatide homeostasis in the nervous system through lipoprotein metabolism pathways and that alterations in apolipoprotein E-mediated sulfatide trafficking can lead to sulfatide depletion in the brain. Collectively, the results obtained from lipidomic analyses of brain samples provide important insights into the biochemical mechanisms underlying the pathogenesis of Alzheimer’s disease.

Han, Xianlin

2010-01-01

174

Multidimensional data scaling - dynamical cascade approach  

Microsoft Academic Search

In this report a multi-dimensional data scaling approach is proposed in data mining and knowledge discovery applications. We derive the method based on an analogy to the physical computation of signal distortion. A dynamical cascade computation diagrams result from the statistical physics model computation in the free energy decomposition. We assess the scale invariance of various data sets, such as

Milan Jovovic; Geoffrey Fox

175

Improving Scaling Properties of Common Statistical Operators for Gridded Geoscience Datasets  

NASA Astrophysics Data System (ADS)

An accurate cost-model that accounts for dataset size and structure can help optimize geoscience data analysis. We develop and apply a computational model to estimate data analysis costs for arithmetic operations on gridded datasets typical of satellite- or climate model-origin. For these dataset geometries our model predicts data reduction scalings that agree with measurements of widely-used geoscience data processing software, the netCDF Operators (NCO). I/O performance and library design dominate throughput for simple analysis (e.g., dataset differencing). Dataset structure can reduce analysis throughput ten-fold relative to same-sized unstructured datasets. We demonstrate algorithmic optimizations which substantially increase throughput for more complex, arithmetic-dominated analysis such as weighted-averaging of multi-dimensional data. Two methods for distributing simultaneous analysis of all variables in data files are intercompared: 1) OpenMP-threading across the set of variables, 2) MPI distribution of variables across a cluster. These scaling properties can help to estimate costs of distribution strategies for data reduction in cluster and grid environments. We show how these priniciples accelerate terascale data reduction by benchmarking the time for NCO to characterize the variability of climate simulations from the Intergovernmental Panel on Climate Change (IPCC) fourth assessment report (AR4). Our algorithms accelerate unoptimized data reduction about tenfold. This improvement is generic in that the same algorithms and operators apply to datasets from any geoscience model producing gridded, multi-dimensional datasets of similar rank.

Mangalam, H.; Zender, C. S.; Wang, D.

2006-12-01

176

Dynamical scaling analysis of plant callus growth  

NASA Astrophysics Data System (ADS)

We present experimental results for the dynamical scaling properties of the development of plant calli. We have assayed two different species of plant calli, Brassica oleracea and Brassica rapa, under different growth conditions, and show that their dynamical scalings share a universality class. From a theoretical point of view, we introduce a scaling hypothesis for systems whose size evolves in time. We expect our work to be relevant for the understanding and characterization of other systems that undergo growth due to cell division and differentiation, such as, for example, tumor development.

Galeano, J.; Buceta, J.; Juarez, K.; Pumariño, B.; de la Torre, J.; Iriondo, J. M.

2003-07-01

177

Detection of crossover time scales in multifractal detrended fluctuation analysis  

NASA Astrophysics Data System (ADS)

Fractal is employed in this paper as a scale-based method for the identification of the scaling behavior of time series. Many spatial and temporal processes exhibiting complex multi(mono)-scaling behaviors are fractals. One of the important concepts in fractals is crossover time scale(s) that separates distinct regimes having different fractal scaling behaviors. A common method is multifractal detrended fluctuation analysis (MF-DFA). The detection of crossover time scale(s) is, however, relatively subjective since it has been made without rigorous statistical procedures and has generally been determined by eye balling or subjective observation. Crossover time scales such determined may be spurious and problematic. It may not reflect the genuine underlying scaling behavior of a time series. The purpose of this paper is to propose a statistical procedure to model complex fractal scaling behaviors and reliably identify the crossover time scales under MF-DFA. The scaling-identification regression model, grounded on a solid statistical foundation, is first proposed to describe multi-scaling behaviors of fractals. Through the regression analysis and statistical inference, we can (1) identify the crossover time scales that cannot be detected by eye-balling observation, (2) determine the number and locations of the genuine crossover time scales, (3) give confidence intervals for the crossover time scales, and (4) establish the statistically significant regression model depicting the underlying scaling behavior of a time series. To substantive our argument, the regression model is applied to analyze the multi-scaling behaviors of avian-influenza outbreaks, water consumption, daily mean temperature, and rainfall of Hong Kong. Through the proposed model, we can have a deeper understanding of fractals in general and a statistical approach to identify multi-scaling behavior under MF-DFA in particular.

Ge, Erjia; Leung, Yee

2012-05-01

178

Detection of crossover time scales in multifractal detrended fluctuation analysis  

NASA Astrophysics Data System (ADS)

Fractal is employed in this paper as a scale-based method for the identification of the scaling behavior of time series. Many spatial and temporal processes exhibiting complex multi(mono)-scaling behaviors are fractals. One of the important concepts in fractals is crossover time scale(s) that separates distinct regimes having different fractal scaling behaviors. A common method is multifractal detrended fluctuation analysis (MF-DFA). The detection of crossover time scale(s) is, however, relatively subjective since it has been made without rigorous statistical procedures and has generally been determined by eye balling or subjective observation. Crossover time scales such determined may be spurious and problematic. It may not reflect the genuine underlying scaling behavior of a time series. The purpose of this paper is to propose a statistical procedure to model complex fractal scaling behaviors and reliably identify the crossover time scales under MF-DFA. The scaling-identification regression model, grounded on a solid statistical foundation, is first proposed to describe multi-scaling behaviors of fractals. Through the regression analysis and statistical inference, we can (1) identify the crossover time scales that cannot be detected by eye-balling observation, (2) determine the number and locations of the genuine crossover time scales, (3) give confidence intervals for the crossover time scales, and (4) establish the statistically significant regression model depicting the underlying scaling behavior of a time series. To substantive our argument, the regression model is applied to analyze the multi-scaling behaviors of avian-influenza outbreaks, water consumption, daily mean temperature, and rainfall of Hong Kong. Through the proposed model, we can have a deeper understanding of fractals in general and a statistical approach to identify multi-scaling behavior under MF-DFA in particular.

Ge, Erjia; Leung, Yee

2013-04-01

179

Scale Analysis of Deep and Shallow Convection in the Atmosphere  

Microsoft Academic Search

The approximate equations of motion derived by Batchelor in 1953 are derived by a formal scale analysis, with the assumption that the percentage range in potential temperature is small and that the time scale is set by the Brunt-Väisälä frequency. Acoustic waves are then absent. If the vertical scale is small compared to the depth of an adiabatic atmosphere, the

Yoshimitsu Ogura; Norman A. Phillips

1962-01-01

180

Estimating Cognitive Profiles Using Profile Analysis via Multidimensional Scaling (PAMS)  

Microsoft Academic Search

Two of the most popular methods of profile analysis, cluster analysis and modal profile analysis, have limitations. First, neither technique is adequate when the sample size is large. Second, neither method will necessarily provide profile information in terms of both level and pattern. A new method of profile analysis, called Profile Analysis via Multidimensional Scaling (PAMS; Davison, 1996), is introduced

Se-Kang Kim; Craig L. Frisby; Mark L. Davison

2004-01-01

181

A Dual Scaling Analysis for Paired Compositions  

ERIC Educational Resources Information Center

|A sensitive measurement model is developed that provides transactional scale values for individual members of a group, as well as an evaluation of pairwise interactions and balances that are emergent properties of the group itself. (Author/DG)|

Bechtel, Gordon G.

1971-01-01

182

Scale detection in real and artificial landscapes using semivariance analysis  

Microsoft Academic Search

Semivariance analysis is potentially useful to landscape ecologists for detecting scales of variability in spatial data. We used semivariance analysis to compare spatial patterns of winter foraging by large ungulates with those of environmental variables that influence forage availability in northern Yellowstone National Park, Wyoming. In addition, we evaluated (1) the ability of semivariograms to detect known scales of variability

Joe E. Meisel; Monica G. Turner

1998-01-01

183

Cepstral analysis synthesis on the mel frequency scale  

Microsoft Academic Search

This paper presents a new technique of cepstral analysis synthesis on the mel frequency scale, the log spectrum on the mel frequency scale (the mel log spectrum) is considered to be an effective representation of the spectral envelope of speech. This analysis synthesis system uses the mel log spectrum approximation (MLSA) filter which was devised for the cepstral synthesis on

S. Imai

1983-01-01

184

Single Parameter Galaxy Classification: The Principal Curve through the Multi-dimensional Space of Galaxy Properties  

NASA Astrophysics Data System (ADS)

We propose to describe the variety of galaxies from the Sloan Digital Sky Survey by using only one affine parameter. To this aim, we construct the principal curve (P-curve) passing through the spine of the data point cloud, considering the eigenspace derived from Principal Component Analysis (PCA) of morphological, physical, and photometric galaxy properties. Thus, galaxies can be labeled, ranked, and classified by a single arc-length value of the curve, measured at the unique closest projection of the data points on the P-curve. We find that the P-curve has a "W" letter shape with three turning points, defining four branches that represent distinct galaxy populations. This behavior is controlled mainly by two properties, namely u - r and star formation rate (from blue young at low arc length to red old at high arc length), while most other properties correlate well with these two. We further present the variations of several important galaxy properties as a function of arc length. Luminosity functions vary from steep Schechter fits at low arc length to double power law and ending in lognormal fits at high arc length. Galaxy clustering shows increasing autocorrelation power at large scales as arc length increases. Cross correlation of galaxies with different arc lengths shows that the probability of two galaxies belonging to the same halo decreases as their distance in arc length increases. PCA analysis allows us to find peculiar galaxy populations located apart from the main cloud of data points, such as small red galaxies dominated by a disk, of relatively high stellar mass-to-light ratio and surface mass density. On the other hand, the P-curve helped us understand the average trends, encoding 75% of the available information in the data. The P-curve allows not only dimensionality reduction but also provides supporting evidence for the following relevant physical models and scenarios in extragalactic astronomy: (1) The hierarchical merging scenario in the formation of a selected group of red massive galaxies. These galaxies present a lognormal r-band luminosity function, which might arise from multiplicative processes involved in this scenario. (2) A connection between the onset of active galactic nucleus activity and star formation quenching as mentioned in Martin et al., which appears in green galaxies transitioning from blue to red populations.

Taghizadeh-Popp, M.; Heinis, S.; Szalay, A. S.

2012-08-01

185

Longitudinal Network Analysis Using Multidimensional Scaling.  

ERIC Educational Resources Information Center

|The Galileo System, a variant of metric multidimensional scaling, is used in this paper to analyze over-time changes in social networks. The paper first discusses the theoretical necessity for the use of this procedure and the methodological problems associated with its use. It then examines the air traffic network among 31 major cities in the…

Barnett, George A.; Palmer, Mark T.

186

Developing assessment scales for large-scale speaking tests: a multiple-method approach  

Microsoft Academic Search

The process of constructing assessment scales for performance testing is complex and multi-dimensional. As a result, a number of different approaches, both empirically and intuitively based, are open to developers. In this paper we outline the approach taken in the revision of a set of assessment scales used with speaking tests, and present the value of combining methodologies to inform

Evelina D. Galaczi; Angela ffrench; Chris Hubbard; Anthony Green

2011-01-01

187

Potential energy surfaces of actinide and transfermium nuclei from multi-dimensional constraint covariant density functional theories  

NASA Astrophysics Data System (ADS)

Multi-dimensional constrained covariant density functional theories were developed recently. In these theories, all shape degrees of freedom ??? deformations with even ? are allowed, e.g., ?20, ?22, ?30, ?32, ?40, ?42, ?44, and so on and the CDFT functional can be one of the following four forms: the meson exchange or point-coupling nucleon interactions combined with the non-linear or density-dependent couplings. In this contribution, some applications of these theories are presented. The potential energy surfaces of actinide nuclei in the (?20, ?22, ?30) deformation space are investigated. It is found that besides the octupole deformation, the triaxiality also plays an important role upon the second fission barriers. The non-axial reflection-asymmetric ?32 shape in some transfermium nuclei with N = 150, namely 246Cm, 248Cf, 250Fm, and 252No are studied.

Lu, Bing-Nan; Zhao, Jie; Zhao, En-Guang; Zhou, Shan-Gui

2012-12-01

188

The importance of a multi-dimensional approach for studying the links between food access and consumption.  

PubMed

Research on neighborhood food access has focused on documenting disparities in the food environment and on assessing the links between the environment and consumption. Relatively few studies have combined in-store food availability measures with geographic mapping of stores. We review research that has used these multi-dimensional measures of access to explore the links between the neighborhood food environment and consumption or weight status. Early research in California found correlations between red meat, reduced-fat milk, and whole-grain bread consumption and shelf space availability of these products in area stores. Subsequent research in New York confirmed the low-fat milk findings. Recent research in Baltimore has used more sophisticated diet assessment tools and store-based instruments, along with controls for individual characteristics, to show that low availability of healthy food in area stores is associated with low-quality diets of area residents. Our research in southeastern Louisiana has shown that shelf space availability of energy-dense snack foods is positively associated with BMI after controlling for individual socioeconomic characteristics. Most of this research is based on cross-sectional studies. To assess the direction of causality, future research testing the effects of interventions is needed. We suggest that multi-dimensional measures of the neighborhood food environment are important to understanding these links between access and consumption. They provide a more nuanced assessment of the food environment. Moreover, given the typical duration of research project cycles, changes to in-store environments may be more feasible than changes to the overall mix of retail outlets in communities. PMID:20410084

Rose, Donald; Bodor, J Nicholas; Hutchinson, Paul L; Swalm, Chris M

2010-04-21

189

MOKKEN: Stata module: Mokken scale analysis  

Microsoft Academic Search

mokken is command for non-parametric scaling of dichotomuous items. It produces results similar to alpha, item A polytomuous version of mokken (due to Molenaar) is under construction, but it doesnot have high priority at this moment. For those with Stata v6 on an internet-accessible machine, install by typing .net cd http:\\/\\/www.fss.uu.nl\\/soc\\/iscore\\/stata\\/ then .net install mokken

Jeroen Weesie

1999-01-01

190

Failure analysis of a pilot scale melter  

Microsoft Academic Search

Failure of the pilot-scale test melter resulted from severe overheating of the Inconel 690 (690) jacketed molybdenum electrode.\\u000a Extreme temperatures were required to melt the glass during this campaign because the feed material contained a very high\\u000a waste loading. Metallurgical evaluation revealed the presence of an alloy containing nickel and molybdenum in several ingots\\u000a found on the bottom of the

K. J. Imrich

2001-01-01

191

Local variance for multi-scale analysis in geomorphometry.  

PubMed

Increasing availability of high resolution Digital Elevation Models (DEMs) is leading to a paradigm shift regarding scale issues in geomorphometry, prompting new solutions to cope with multi-scale analysis and detection of characteristic scales. We tested the suitability of the local variance (LV) method, originally developed for image analysis, for multi-scale analysis in geomorphometry. The method consists of: 1) up-scaling land-surface parameters derived from a DEM; 2) calculating LV as the average standard deviation (SD) within a 3 × 3 moving window for each scale level; 3) calculating the rate of change of LV (ROC-LV) from one level to another, and 4) plotting values so obtained against scale levels. We interpreted peaks in the ROC-LV graphs as markers of scale levels where cells or segments match types of pattern elements characterized by (relatively) equal degrees of homogeneity. The proposed method has been applied to LiDAR DEMs in two test areas different in terms of roughness: low relief and mountainous, respectively. For each test area, scale levels for slope gradient, plan, and profile curvatures were produced at constant increments with either resampling (cell-based) or image segmentation (object-based). Visual assessment revealed homogeneous areas that convincingly associate into patterns of land-surface parameters well differentiated across scales. We found that the LV method performed better on scale levels generated through segmentation as compared to up-scaling through resampling. The results indicate that coupling multi-scale pattern analysis with delineation of morphometric primitives is possible. This approach could be further used for developing hierarchical classifications of landform elements. PMID:21779138

Dr?gu?, Lucian; Eisank, Clemens; Strasser, Thomas

2011-07-15

192

Modeling surface-water flow and sediment mobility with the Multi-Dimensional Surface-Water Modeling System (MD_SWMS)  

USGS Publications Warehouse

The Multi-Dimensional Surface-Water Modeling System (MD_SWMS) is a Graphical User Interface for surface-water flow and sediment-transport models. The capabilities of MD_SWMS for developing models include: importing raw topography and other ancillary data; building the numerical grid and defining initial and boundary conditions; running simulations; visualizing results; and comparing results with measured data.

McDonald, Richard; Nelson, Jonathan; Kinzel, Paul; Conaway, Jeff

2006-01-01

193

Genetic Analysis of Invasive Plant Populations at Different Spatial Scales  

Microsoft Academic Search

Measuring genetic diversity requires selection of a spatial scale of analysis. Different levels of genetic structuring are\\u000a revealed at different spatial scales, however, and the relative importance of factors driving genetic structuring varies along\\u000a the spatial scale continuum. Unequal gene flow is a major factor determining genetic structure in plant populations at the\\u000a local level, while the effect of selection

Sarah Ward

2006-01-01

194

Confirmatory factor analysis of the General Self-Efficacy Scale  

Microsoft Academic Search

A confirmatory factor analysis of the factor structure of the adapted General Self-Efficacy Scale, created by Sherer et al. (1982) [Psychological Reports, 51, 663–671], was conducted to assess whether the scale’s purported 3 factors emerged. The results generally supported the 3-factor model, but a model with 3 correlated factors and one higher-order factor (general self-efficacy) proved to fit the data

Rudolf J. Bosscher; Johannes H. Smit

1998-01-01

195

Scaling properties of sea ice deformation from buoy dispersion analysis  

Microsoft Academic Search

A temporal and spatial scaling analysis of Arctic sea ice deformation is performed over timescales from 3 h to 3 months and over spatial scales from 300 m to 300 km. The deformation is derived from the dispersion of pairs of drifting buoys, using the IABP (International Arctic Buoy Program) buoy data sets. This study characterizes the deformation of a

P. Rampal; J. Weiss; D. Marsan; R. Lindsay; H. Stern

2008-01-01

196

An Empirical Analysis of the Tennessee Self Concept Scale  

Microsoft Academic Search

A study was conducted to investigate the contributions of the Tennessee Self Concept Scale to the understanding of self-concept components. An Alpha Factor Analysis was employed to examine the independence of the instrument's subscales. Canonical correlations were used to investigate the independence of the Scale's \\

Ronald E. Pound; James C. Hansen; Barbara A. Putnam

1977-01-01

197

Mining Approximate Top-K Subspace Anomalies in MultiDimensional Time-Series Data  

Microsoft Academic Search

Market analysis is a representative data analysis process with many applications. In such an analysis, critical nu- merical measures, such as proflt and sales, ?uctuate over time and form time-series data. Moreover, the time series data correspond to market segments, which are described by a set of attributes, such as age, gender, education, income level, and product-category, that form a

Xiaolei Li; Jiawei Han

2007-01-01

198

Evidence for a Multi-Dimensional Latent Structural Model of Externalizing Disorders  

ERIC Educational Resources Information Center

|Strong associations between conduct disorder (CD), antisocial personality disorder (ASPD) and substance use disorders (SUD) seem to reflect a general vulnerability to externalizing behaviors. Recent studies have characterized this vulnerability on a continuous scale, rather than as distinct categories, suggesting that the revision of the…

Witkiewitz, Katie; King, Kevin; McMahon, Robert J.; Wu, Johnny; Luk, Jeremy; Bierman, Karen L.; Coie, John D.; Dodge, Kenneth A.; Greenberg, Mark T.; Lochman, John E.; Pinderhughes, Ellen E.

2013-01-01

199

The Growing Hierarchical Self-Organizing Map (GHSOM) for analysing multi-dimensional stream habitat datasets  

Microsoft Academic Search

River field surveys are carried out to describe biological habitats and the main geomorphic features of a river stretch. They can be extensive, expensive and time consuming campaigns sampling a high number of features. These features belong to a complex river ecosystem characterized by many different processes at various scales from simple to highly non linear. Researchers need sophisticated techniques

S. Bizzi; R. F. Harrison; D. N. Lerner

200

Efficient organization and access of multi-dimensional datasets on tertiary storage systems  

Microsoft Academic Search

This paper addresses the problem of urgently needed data management techniques for efficiently retrieving requested subsets of large datasets from mass storage devices. This problem is especially critical for scientific investigators who need ready access to the large volume of data generated by large-scale supercomputer simulations and physical experiments as well as the automated collection of observations by monitoring devices

Ling Tony Chen; R. Drach; M. Keating; S. Louis; Doron Rotem; Arie Shoshani

1995-01-01

201

New Framework for Large Scale Data Envelopment Analysis (DEA).  

National Technical Information Service (NTIS)

This project proposes to investigate a new framework for large scale DEA studies that will reduce computation times and increase analysis flexibility. The methodology is based on an initial extraction of essential elements known as extreme efficient DMUs....

J. H. Dula

1999-01-01

202

Source Code Analysis Laboratory (SCALe) for Energy Delivery Systems.  

National Technical Information Service (NTIS)

The Source Code Analysis Laboratory (SCALe) is an operational capability that tests software applications for conformance to one of the CERT(registered name) secure coding standards. CERT secure coding standards provide a detailed enumeration of coding er...

J. McCurley P. Miller R. Stoddard R. C. Seacord W. Dormann

2010-01-01

203

The W-6 approach to multi-dimensional scheduling: where AI and operations research meet  

Microsoft Academic Search

Inherent limitations of the traditional approaches to scheduling and allocation of resources are pinpointed, and new directions are proposed. These are based on five years experience with very-large-scale scheduling problems that resulted in a working software system called W-6. W-6, which represents a compromised approach that may not generate a globally optimal solution but has proven to lead to practical

M. Ben Bassat; Y. Kfir; Z. Melamed; D. Schapiro; A. Shpiro

1990-01-01

204

Genome-scale DNA methylation analysis  

PubMed Central

The haploid human genome contains approximately 29 million CpGs that exist in a methylated, hydroxymethylated or unmethylated state, collectively referred to as the DNA methylome. The methylation status of cytosines in CpGs and occasionally in non-CpG cytosines influences protein–DNA interactions, gene expression, and chromatin structure and stability. The degree of DNA methylation at particular loci may be heritable transgenerationally and may be altered by environmental exposures and diet, potentially contributing to the development of human diseases. For the vast majority of normal and disease methylomes however, less than 1% of the CpGs have been assessed, revealing the formative stage of methylation mapping techniques. Thus, there is significant discovery potential in new genome-scale platforms applied to methylome mapping, particularly oligonucleotide arrays and the transformative technology of next-generation sequencing. Here, we outline the currently used methylation detection reagents and their application to microarray and sequencing platforms. A comparison of the emerging methods is presented, highlighting their degrees of technical complexity, methylome coverage and precision in resolving methylation. Because there are hundreds of unique methylomes to map within one individual and interindividual variation is likely to be significant, international coordination is essential to standardize methylome platforms and to create a full repository of methylome maps from tissues and unique cell types.

Fouse, Shaun D; Nagarajan, Raman P; Costello, Joseph F

2010-01-01

205

Bayesian inference in the scaling analysis of critical phenomena  

NASA Astrophysics Data System (ADS)

To determine the universality class of critical phenomena, we propose a method of statistical inference in the scaling analysis of critical phenomena. The method is based on Bayesian statistics, most specifically, the Gaussian process regression. It assumes only the smoothness of a scaling function, and it does not need a form. We demonstrate this method for the finite-size scaling analysis of the Ising models on square and triangular lattices. Near the critical point, the method is comparable in accuracy to the least-square method. In addition, it works well for data to which we cannot apply the least-square method with a polynomial of low degree. By comparing the data on triangular lattices with the scaling function inferred from the data on square lattices, we confirm the universality of the finite-size scaling function of the two-dimensional Ising model.

Harada, Kenji

2011-11-01

206

Bayesian inference in the scaling analysis of critical phenomena.  

PubMed

To determine the universality class of critical phenomena, we propose a method of statistical inference in the scaling analysis of critical phenomena. The method is based on Bayesian statistics, most specifically, the Gaussian process regression. It assumes only the smoothness of a scaling function, and it does not need a form. We demonstrate this method for the finite-size scaling analysis of the Ising models on square and triangular lattices. Near the critical point, the method is comparable in accuracy to the least-square method. In addition, it works well for data to which we cannot apply the least-square method with a polynomial of low degree. By comparing the data on triangular lattices with the scaling function inferred from the data on square lattices, we confirm the universality of the finite-size scaling function of the two-dimensional Ising model. PMID:22181544

Harada, Kenji

2011-11-18

207

Wavelet analysis of dominant scales of heterogeneous porous media  

NASA Astrophysics Data System (ADS)

Heterogeneity of aquifer permeability has a significant influence on the transport of solutes; therefore characterization of aquifer heterogeneity is needed to accurately predict the behavior of solutes. A critical characteristic of heterogeneity is a characteristic length scale that is a measure of the distance over which property values are correlated. We show that the characteristic length scale of a statistically homogeneous permeability field can be identified through wavelet analysis using the global wavelet energy spectrum (GWES). The relationship between the wavelet scale and the characteristic length scale of a random field is investigated for the Mexican hat and Morlet wavelets and different covariance structures. The ability of the GWES to identify multiple characteristic length scales in a random field with nested covariance structures is also investigated. We use the technique to identify the characteristic length scales of a laboratory-collected permeability transect from Massillon sandstone.

Qi, Xing; Neupauer, Roseanna M.

2008-09-01

208

Analysis Of Significant Wave Height Temporal And Spatial Scales  

Microsoft Academic Search

A, scale analysis in time and space of the significant wave height (H,) based on stationarity and correlation analysis is presented. A sea-state is defined as a state of a piecewise stationary stochastic random wave process and is characterized by its duration (or length) and its energy. A metlhod to identify the stationary components of the wave process is to

Jean Tournadre

1991-01-01

209

A scaling analysis of ozone photochemistry: I Model development  

Microsoft Academic Search

A scaling analysis has been used to capture the integrated behaviour of several photochemical mechanisms for a wide range of precursor concentrations and a variety of environmental conditions. The Buckingham Pi method of dimensional analysis was used to express the relevant variables in terms of dimensionless groups. These grouping show maximum ozone, initial NOx and initial VOC concentrations are made

B. Ainslie; D. G. Steyn

2005-01-01

210

Evaluation of multi-dimensional flux models for radiative transfer in cylindrical combustion chambers  

NASA Astrophysics Data System (ADS)

Four flux-type models for radiative heat transfer in cylindrical configurations were applied to the prediction of radiative flux density and source term of a cylindrical enclosure problem based on data reported previously on a pilot-scale experimental combustor with steep temperature gradients. The models, which are Schuster-Hamaker type four-flux model derived by Lockwood and Spalding, two Schuster-Schwarzschild type four-flux models derived by Siddall and Selcuk and Richter and Quack and spherical harmonics approximation, were evaluated from the viewpoint of predictive accuracy by comparing their predictions with exact solutions produced previously. The comparisons showed that spherical harmonics approximation produces more accurate results than the other models with respect to the radiative energy source term and that the four-flux models of Lockwood and Spalding and Siddall and Selcuk for isotropic radiation field are more accurate with respect to the prediction of radiative flux density to the side wall.

Selcuk, Nevin

1993-02-01

211

Indexing multi-dimensional time-series with support for multiple distance measures  

Microsoft Academic Search

Although most time-series data mining research has concentrated on providing solutions for a single distance function, in this work we motivate the need for a single index structure that can support multiple distance measures. Our specific area of interest is the efficient retrieval and analysis of trajectory similarities. Trajectory datasets are very common in environmental applications, mobility experiments, video surveillance

Michail Vlachos; Marios Hadjieleftheriou; Dimitrios Gunopulos; Eamonn J. Keogh

2003-01-01

212

Identification of chemical-adducted proteins in urine by multi-dimensional protein identification technology (LC/LC-MS/MS).  

PubMed

Recent technological advancements in mass spectrometry facilitate the detection of chemical-induced posttranslational modifications (PTMs) that may alter cell signaling pathways or alter the structure and function of the modified proteins. To identify such protein adducts (Kleiner et al., Chem Res Toxicol 11:1283-1290, 1998), multi-dimensional protein identification technology (MuDPIT) has been utilized. MuDPIT was first described by Link et al. as a new technique useful for protein identification from a complex mixture of proteins (Link et al., Nat Biotechnol 17:676-682, 1999). MuDPIT utilizes two different HPLC columns to further enhance peptide separation, increasing the number of peptide hits and protein coverage. The technology is extremely useful for proteomes, such as the urine proteome, samples from immunoprecipitations, and 1D gel bands resolved from a tissue homogenate or lysate. In particular, MuDPIT has enhanced the field of adduct hunting for adducted peptides, since it is more capable of identifying lesser abundant peptides, such as those that are adducted, than the more standard LC-MS/MS. The site-specific identification of covalently adducted proteins is a prerequisite for understanding the biological significance of chemical-induced PTMs and the subsequent toxicological response they elicit. PMID:20972764

Labenski, Matthew T; Fisher, Ashley A; Monks, Terrence J; Lau, Serrine S

2011-01-01

213

POLARIZED LINE FORMATION IN MULTI-DIMENSIONAL MEDIA. II. A FAST METHOD TO SOLVE PROBLEMS WITH PARTIAL FREQUENCY REDISTRIBUTION  

SciTech Connect

In the previous paper of this series, we presented a formulation of the polarized radiative transfer equation for resonance scattering with partial frequency redistribution (PRD) in multi-dimensional media for a two-level atom model with unpolarized ground level, using the irreducible spherical tensors T{sub Q}{sup K}(i, {Omega}) for polarimetry. We also presented a polarized approximate lambda iteration method to solve this equation using the Jacobi iteration scheme. The formal solution used was based on a simple finite volume technique. In this paper, we develop a faster and more efficient method which uses the projection techniques applied to the radiative transfer equation (the Stabilized Preconditioned Bi-Conjugate Gradient method). We now use a more accurate formal solver, namely the well-known two-dimensional (2D) short characteristics method. Using the numerical method developed in Paper I, we can consider only simpler cases of finite 2D slabs due to computational limitations. Using the method developed in this paper, we could compute PRD solutions in 2D media in the more difficult context of semi-infinite 2D slabs also. We present several solutions which may serve as benchmarks in future studies in this area.

Anusha, L. S.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, 2nd Block, Bengaluru 560 034 (India); Paletou, F. [Laboratoire d'Astrophysique de Toulouse-Tarbes, Universite de Toulouse, CNRS, 14 Avenue E. Belin, F-31400 Toulouse (France)

2011-01-10

214

Taking sociality seriously: the structure of multi-dimensional social networks as a source of information for individuals  

PubMed Central

Understanding human cognitive evolution, and that of the other primates, means taking sociality very seriously. For humans, this requires the recognition of the sociocultural and historical means by which human minds and selves are constructed, and how this gives rise to the reflexivity and ability to respond to novelty that characterize our species. For other, non-linguistic, primates we can answer some interesting questions by viewing social life as a feedback process, drawing on cybernetics and systems approaches and using social network neo-theory to test these ideas. Specifically, we show how social networks can be formalized as multi-dimensional objects, and use entropy measures to assess how networks respond to perturbation. We use simulations and natural ‘knock-outs’ in a free-ranging baboon troop to demonstrate that changes in interactions after social perturbations lead to a more certain social network, in which the outcomes of interactions are easier for members to predict. This new formalization of social networks provides a framework within which to predict network dynamics and evolution, helps us highlight how human and non-human social networks differ and has implications for theories of cognitive evolution.

Barrett, Louise; Henzi, S. Peter; Lusseau, David

2012-01-01

215

Processing of Multi-dimensional Sensorimotor Information in the Spinal and Cerebellar Neuronal Circuitry: A New Hypothesis  

PubMed Central

Why are sensory signals and motor command signals combined in the neurons of origin of the spinocerebellar pathways and why are the granule cells that receive this input thresholded with respect to their spike output? In this paper, we synthesize a number of findings into a new hypothesis for how the spinocerebellar systems and the cerebellar cortex can interact to support coordination of our multi-segmented limbs and bodies. A central idea is that recombination of the signals available to the spinocerebellar neurons can be used to approximate a wide array of functions including the spatial and temporal dependencies between limb segments, i.e. information that is necessary in order to achieve coordination. We find that random recombination of sensory and motor signals is not a good strategy since, surprisingly, the number of granule cells severely limits the number of recombinations that can be represented within the cerebellum. Instead, we propose that the spinal circuitry provides useful recombinations, which can be described as linear projections through aspects of the multi-dimensional sensorimotor input space. Granule cells, potentially with the aid of differentiated thresholding from Golgi cells, enhance the utility of these projections by allowing the Purkinje cell to establish piecewise-linear approximations of non-linear functions. Our hypothesis provides a novel view on the function of the spinal circuitry and cerebellar granule layer, illustrating how the coordinating functions of the cerebellum can be crucially supported by the recombinations performed by the neurons of the spinocerebellar systems.

Spanne, Anton; Jorntell, Henrik

2013-01-01

216

Knowledge discovery in urban environments from fused multi-dimensional imagery  

Microsoft Academic Search

With all the exciting advances in sensor fusion and data interpretation technologies in recent years, including co-registration, 3-D surface reconstruction, object recognition, spatial reasoning, and more, high-quality detailed and precise segmentation of remote sensing spectral images remains a much needed key component in the comprehensive analysis and understanding of surfaces. Urban surfaces are no exception. In fact, urban surfaces can

Erzsebet Merenyi; Beata Csatho; Kadim Tasdemir

2007-01-01

217

Multi-dimensional simulations of Magnetic Field Seeding of Plasma via Laser Beatwave Interaction  

NASA Astrophysics Data System (ADS)

Assembling magnetized plasma for inertial fusion permits longer duration and smaller density-radius product fuel implosions by reducing the energy transport significantly. For fusion energy, however, the field must be created with a significant standoff distance. A promising technique for magnetic field production is the beat-wave interaction.ootnotetextM. N. Rosenbluth and C. S. Liu, Phys. Rev. Lett. 29, 701 (1972). Some theoretical results have been confirmed by microwave experiments.ootnotetextJ. H. Rogers and D. Q. Hwang, Phys. Rev. Lett. 68, 3877 (1992). Recently, fully-kinetic 2D and 3D simulations of the interaction have been simulated using the Lsp particle-in-cell code. We inject 2 CO2 100-micron transverse-extent lasers both with 10^13 W/cm^2 intensity into a peak 3x10^16 cm-3 density plasma at various angles. The calculated interaction produces beatwaves at the predicted wavelength and frequency and drives magnetic fields up to 2.5 kG. We will examine the sensitivity of the efficiency of magnetic field production to laser parameters and plasma density scale length and discuss the application to the Plasma Liner eXperiment at LANL.

Welch, Dale; Thoma, Carsten; Bruner, Nichelle; Hwang, David; Hsu, Scott

2011-11-01

218

Multi-Dimensional Simulations of Fluorocarbon Plasmas with Ion Energy Resolved Surface Reaction Rates  

NASA Astrophysics Data System (ADS)

The commercial CFD-ACE+ software has been extended to account for ion energy dependent surface reactions. The ion energy distribution function and the mean ion energy at a biased wafer were obtained using the Riley sheath model extended by the NASA group (Bose et al., J. Appl. Phys. v.87, 7176(2000)). The plasma chemistry model (by P. Ho et al., SAND2001-1292) consisting of 132-step gas-phase reactions and 55-step ion energy dependent surface reactions, was implemented to simulate the C2F6 plasma etching of silicon dioxide in an Inductively Coupled Plasma. Validation studies have been performed against the experimental data by Anderson et al. of UNM for a lab-scale GEC reactor. For a wide range of operating conditions (pressure: 5-25 mTorr; plasma power: 205-495 Watts; bias power: 22-148 Watts), the average etch rate calculated by CFD-ACE+ 2-D simulations agrees very well with those by 0-D AURORA predictions and the experimental data. The CFD-ACE+ simulations allow one to study the radial uniformity of the etch rate depending on discharge conditions.

Zhou, Ning; Kolobov, Vladimir; Kudriavtsev, Vladimir

2001-10-01

219

Multi-dimensional characterization of electrostatic surface potential computation on graphics processors  

PubMed Central

Background Calculating the electrostatic surface potential (ESP) of a biomolecule is critical towards understanding biomolecular function. Because of its quadratic computational complexity (as a function of the number of atoms in a molecule), there have been continual efforts to reduce its complexity either by improving the algorithm or the underlying hardware on which the calculations are performed. Results We present the combined effect of (i) a multi-scale approximation algorithm, known as hierarchical charge partitioning (HCP), when applied to the calculation of ESP and (ii) its mapping onto a graphics processing unit (GPU). To date, most molecular modeling algorithms perform an artificial partitioning of biomolecules into a grid/lattice on the GPU. In contrast, HCP takes advantage of the natural partitioning in biomolecules, which in turn, better facilitates its mapping onto the GPU. Specifically, we characterize the effect of known GPU optimization techniques like use of shared memory. In addition, we demonstrate how the cost of divergent branching on a GPU can be amortized across algorithms like HCP in order to deliver a massive performance boon. Conclusions We accelerated the calculation of ESP by 25-fold solely by parallelization on the GPU. Combining GPU and HCP, resulted in a speedup of at most 1,860-fold for our largest molecular structure. The baseline for these speedups is an implementation that has been hand-tuned SSE-optimized and parallelized across 16 cores on the CPU. The use of GPU does not deteriorate the accuracy of our results.

2012-01-01

220

Accurate Simulation of Multi-Dimensional Detonation Waves in a Shock-Attached Frame  

NASA Astrophysics Data System (ADS)

Numerical simulation of detonation waves is a challenging problem due to resolution requirements necessary to compute highly nonlinear multiple-scale dynamics of the shock--reaction zone structure. Widely used shock-capturing techniques are often inadequate when dealing with unstable detonations. Large errors at the lead shock propagate into the reaction zone, amplify, and can dominate the true dynamics of the detonation instability. In order to eliminate the shock-capturing errors at the lead shock, we propose a shock fitting algorithm that is based on numerical integration of the reactive Euler equations in the frame attached to the lead shock. A local system of hyperbolic partial differential equations on the shock coupled to the Euler equations inside the reaction zone is derived and used as part of a numerical algorithm. With high-order time- and space discretizations, we compute the growth of linear instability into non-linear cellular detonation waves. For the first time, we performed detailed verification of the results of detonation stability theory in two dimensions. Our approach is ideally suited for testing detonation stability theories as well as nonlinear asymptotic theories such as detonation shock dynamics.

Kasimov, Aslan

2008-11-01

221

Scale and stability analysis of selected atmospheric blocking events  

NASA Astrophysics Data System (ADS)

Global six year climatology of mid latitude atmospheric blocking events, during the period 1999--2004, is presented based on the scale and stability analysis, using the NCEP/NCAR re-analysis data. A total of 278 blocking events over the Northern as well as the Southern Hemispheres are analyzed. The 500 mb geopotential height is decomposed into the planetary- and the synoptic-scale geopotential heights. The heights are then averaged over a 40° x 60° latitude longitude box D, harboring the blocking event. The averaged heights are compared with their corresponding monthly mean values during the month in which the blocking event has occurred. A positive planetary-scale geopotential height dominance behavior for a given blocking event is defined as a positive planetary-scale height anomaly above its monthly mean value. Similar procedure is adopted to define synoptic-scale dominance behavior. It is pointed out that globally, over the six year period, 83% of the blocking events have single-scale dominance, whereas remaining 17% of the blocking events have an alternating-scale dominance behavior. In the Northern Hemisphere, during the later half of the six year period, a 28% rise in the planetary-scale dominance behavior blocking events is noticed over the synoptic-scale dominance behavior blocking events. Stability analysis of the blocking events over the six year period is performed, under the assumption of barotropic flow, using the following three stability indicators: i) max |?psi|, ii) max|?Oa |, and iii) D |O|²(y)dxdy. Here, psi is geosptrophic stream function, Oa is the absolute vorticity and O = - ?u/ ?y, in usual meteorological notation. A comparison of the time variability of the three stability indicators over the entire life cycle of the selected blocking events with earlier works performing the synoptic and dynamics studies shows that the three stability indicators can be used as climatologically reliable stability indicators giving useful insight into the stability of the flow attending the blocking event. It is noticed that in the scale dependent flow, the scale that dominates during the mature stage of the blocking event determines the stability of the flow during the blocking, and that the blocking is relatively more stable state than the more frequent zonal flow, irrespective of which scale dominates the flow during blocking. For the selected blocking events, the calculations for both the scale height dominance as well as for the stability of the flow attending the blocking are extended to include the stratospheric signals as well, for operational relevance.

Hussain, Athar

222

Scaling analysis for a Savannah River reactor scaled model integral system  

Microsoft Academic Search

The Savannah River Laboratory has requested that the Idaho National Engineering Laboratory perform an analysis to help define, examine, and assess potential concepts for the design of a scaled integral hydraulics test facility representative of the current Savannah River Plant reactor design. In this report the thermal-hydraulic phenomena of importance (based on the knowledge and experience of the authors and

T. J. Boucher; T. K. Larson; G. E. McCreery; J. L. Anderson

1990-01-01

223

Sensate abstraction: hybrid strategies for multi-dimensional data in expressive virtual reality contexts  

NASA Astrophysics Data System (ADS)

ATLAS in silico is an interactive installation/virtual environment that provides an aesthetic encounter with metagenomics data (and contextual metadata) from the Global Ocean Survey (GOS). The installation creates a visceral experience of the abstraction of nature in to vast data collections - a practice that connects expeditionary science of the 19th Century with 21st Century expeditions like the GOS. Participants encounter a dream-like, highly abstract, and datadriven virtual world that combines the aesthetics of fine-lined copper engraving and grid-like layouts of 19th Century scientific representation with 21st Century digital aesthetics including wireframes and particle systems. It is resident at the Calit2 Immersive visualization Laboratory on the campus of UC San Diego, where it continues in active development. The installation utilizes a combination of infrared motion tracking, custom computer vision, multi-channel (10.1) spatialized interactive audio, 3D graphics, data sonification, audio design, networking, and the VarrierTM 60 tile, 100-million pixel barrier strip auto-stereoscopic display. Here we describe the physical and audio display systems for the installation and a hybrid strategy for multi-channel spatialized interactive audio rendering in immersive virtual reality that combines amplitude, delay and physical modeling-based, real-time spatialization approaches for enhanced expressivity in the virtual sound environment that was developed in the context of this artwork. The desire to represent a combination of qualitative and quantitative multidimensional, multi-scale data informs the artistic process and overall system design. We discuss the resulting aesthetic experience in relation to the overall system.

West, Ruth; Gossmann, Joachim; Margolis, Todd; Schulze, Jurgen P.; Lewis, J. P.; Hackbarth, Ben; Mostafavi, Iman

2009-02-01

224

Imaging Multi-Dimensional Electrical Resistivity Structure as a Tool in Developing Enhanced Geothermal Systems (EGS)  

SciTech Connect

The overall goal of this project has been to develop desktop capability for 3-D EM inversion as a complement or alternative to existing massively parallel platforms. We have been fortunate in having a uniquely productive cooperative relationship with Kyushu University (Y. Sasaki, P.I.) who supplied a base-level 3-D inversion source code for MT data over a half-space based on staggered grid finite differences. Storage efficiency was greatly increased in this algorithm by implementing a symmetric L-U parameter step solver, and by loading the parameter step matrix one frequency at a time. Rules were established for achieving sufficient jacobian accuracy versus mesh discretization, and regularization was much improved by scaling the damping terms according to influence of parameters upon the measured response. The modified program was applied to 101 five-channel MT stations taken over the Coso East Flank area supported by the DOE and the Navy. Inversion of these data on a 2 Gb desktop PC using a half-space starting model recovered the main features of the subsurface resistivity structure seen in a massively parallel inversion which used a series of stitched 2-D inversions as a starting model. In particular, a steeply west-dipping, N-S trending conductor was resolved under the central-west portion of the East Flank. It may correspond to a highly saline magamtic fluid component, residual fluid from boiling, or less likely cryptic acid sulphate alteration, all in a steep fracture mesh. This work gained student Virginia Maris the Best Student Presentation at the 2006 GRC annual meeting.

Philip E. Wannamaker

2007-12-31

225

Evidence for a multi-dimensional latent structural model of externalizing disorders.  

PubMed

Strong associations between conduct disorder (CD), antisocial personality disorder (ASPD) and substance use disorders (SUD) seem to reflect a general vulnerability to externalizing behaviors. Recent studies have characterized this vulnerability on a continuous scale, rather than as distinct categories, suggesting that the revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) take into account the underlying continuum of externalizing behaviors. However, most of this research has not included measures of disorders that appear in childhood [e.g., attention-deficit/hyperactivity disorder (ADHD) or oppositional defiant disorder (ODD)], nor has it considered the full range of possibilities for the latent structure of externalizing behaviors, particularly factor mixture models, which allow for a latent factor to have both continuous and categorical dimensions. Finally, the majority of prior studies have not tested multidimensional models. Using lifetime diagnoses of externalizing disorders from participants in the Fast Track Project (n?=?715), we analyzed a series of latent variable models ranging from fully continuous factor models to fully categorical mixture models. Continuous models provided the best fit to the observed data and also suggested that a two-factor model of externalizing behavior, defined as (1) ODD+ADHD+CD and (2) SUD with adult antisocial behavior sharing common variance with both factors, was necessary to explain the covariation in externalizing disorders. The two-factor model of externalizing behavior was then replicated using a nationally representative sample drawn from the National Comorbidity Survey-Replication data (n?=?5,692). These results have important implications for the conceptualization of externalizing disorders in DSM-5. PMID:22936218

Witkiewitz, Katie; King, Kevin; McMahon, Robert J; Wu, Johnny; Luk, Jeremy; Bierman, Karen L; Coie, John D; Dodge, Kenneth A; Greenberg, Mark T; Lochman, John E; Pinderhughes, Ellen E

2013-02-01

226

Multiple-Scale Analysis of the Quantum Anharmonic Oscillator  

SciTech Connect

Conventional weak-coupling perturbation theory suffers from problems that arise from the resonant coupling of successive orders in the perturbation series. Multiple-scale perturbation theory avoids such problems by implicitly performing an infinite reordering and resummation of the conventional perturbation series. Multiple-scale analysis provides a good description of the {ital classical} anharmonic oscillator. Here, it is extended to study the Heisenberg operator equations of motion for the quantum anharmonic oscillator. The analysis yields a system of nonlinear operator differential equations, which is solved exactly. The solution provides an operator mass renormalization of the theory. {copyright} {ital 1996 The American Physical Society.}

Bender, C.M.; Bettencourt, L.M. [Blackett Laboratory, Imperial College, London SW72BZ (United Kingdom)

1996-11-01

227

Shielding analysis methods available in the scale computational system  

SciTech Connect

Computational tools have been included in the SCALE system to allow shielding analysis to be performed using both discrete-ordinates and Monte Carlo techniques. One-dimensional discrete ordinates analyses are performed with the XSDRNPM-S module, and point dose rates outside the shield are calculated with the XSDOSE module. Multidimensional analyses are performed with the MORSE-SGC/S Monte Carlo module. This paper will review the above modules and the four Shielding Analysis Sequences (SAS) developed for the SCALE system. 7 refs., 8 figs.

Parks, C.V.; Tang, J.S.; Hermann, O.W.; Bucholz, J.A.; Emmett, M.B.

1986-01-01

228

A novel coordination polymer with dicyanamide ligand: multi-dimensional architecture stabilized by hydrogen bonding  

Microsoft Academic Search

A novel dicyanamide (dca) complex, [Cu(pn)(dca)2]n (pn=1,2-diaminopropane), was synthesized and characterized. X-ray diffraction analysis reveals that the title complex crystallizes in the monoclinic space group C2\\/c with a=12.436(5)A?,b=8.395(3)A?,c=20.747(8)A?,?=96.662(6)°, Z=8, and R1=0.0476, wR2=0.1094. The complex exhibits one-dimensional zigzag chain structure constructed by ?1,5-dca bridges. The coordination geometry around the copper atom was a distorted square-pyramid. The spectroscopic and magnetic properties have

Xiao-Yan Chen; Peng Cheng; Bin Zhao; Shi-Ping Yan; Dai-Zheng Liao; Zong-Hui Jiang

2003-01-01

229

Amira: Multi-Dimensional Scientific Visualization for the GeoSciences in the 21st Century  

NASA Astrophysics Data System (ADS)

amira (www.amiravis.com) is a general purpose framework for 3D scientific visualization that meets the needs of the non-programmer, the script writer, and the advanced programmer alike. Provided modules may be visually assembled in an interactive manner to create complex visual displays. These modules and their associated user interfaces are controlled either through a mouse, or via an interactive scripting mechanism based on Tcl. We provide interactive demonstrations of the various features of Amira and explain how these may be used to enhance the comprehension of datasets in use in the Earth Sciences community. Its features will be illustrated on scalar and vector fields on grid types ranging from Cartesian to fully unstructured. Specialized extension modules developed by some of our collaborators will be illustrated [1]. These include a module to automatically choose values for salient isosurface identification and extraction, and color maps suitable for volume rendering. During the session, we will present several demonstrations of remote networking, processing of very large spatio-temporal datasets, and various other projects that are underway. In particular, we will demonstrate WEB-IS, a java-applet interface to Amira that allows script editing via the web, and selected data analysis [2]. [1] G. Erlebacher, D. A. Yuen, F. Dubuffet, "Case Study: Visualization and Analysis of High Rayleigh Number -- 3D Convection in the Earth's Mantle", Proceedings of Visualization 2002, pp. 529--532. [2] Y. Wang, G. Erlebacher, Z. A. Garbow, D. A. Yuen, "Web-Based Service of a Visualization Package 'amira' for the Geosciences", Visual Geosciences, 2003.

Bartsch, H.; Erlebacher, G.

2003-12-01

230

Generalized solution to multi-dimensional multi-species transport equations coupled with a first-order reaction network involving distinct retardation factors  

Microsoft Academic Search

This paper presents a general method for solving coupled multi-dimensional, multi-species reactive transport equations. The new method can be used for solving multi-species transport problems involving first-order kinetic interactions and distinct retardation factors. The solution process employs Laplace transformation and linear transformation steps to uncouple the governing set of coupled partial differential equations. The uncoupled equations are solved using an

Cristhian R. Quezada; T. Prabhakar Clement; Kang-Kun Lee

2004-01-01

231

The vulnerability cube: a multi-dimensional framework for assessing relative vulnerability.  

PubMed

The diversity and abundance of information available for vulnerability assessments can present a challenge to decision-makers. Here we propose a framework to aggregate and present socioeconomic and environmental data in a visual vulnerability assessment that will help prioritize management options for communities vulnerable to environmental change. Socioeconomic and environmental data are aggregated into distinct categorical indices across three dimensions and arranged in a cube, so that individual communities can be plotted in a three-dimensional space to assess the type and relative magnitude of the communities' vulnerabilities based on their position in the cube. We present an example assessment using a subset of the USEPA National Estuary Program (NEP) estuaries: coastal communities vulnerable to the effects of environmental change on ecosystem health and water quality. Using three categorical indices created from a pool of publicly available data (socioeconomic index, land use index, estuary condition index), the estuaries were ranked based on their normalized averaged scores and then plotted along the three axes to form a vulnerability cube. The position of each community within the three-dimensional space communicates both the types of vulnerability endemic to each estuary and allows for the clustering of estuaries with like-vulnerabilities to be classified into typologies. The typologies highlight specific vulnerability descriptions that may be helpful in creating specific management strategies. The data used to create the categorical indices are flexible depending on the goals of the decision makers, as different data should be chosen based on availability or importance to the system. Therefore, the analysis can be tailored to specific types of communities, allowing a data rich process to inform decision-making. PMID:21638079

Lin, Brenda B; Morefield, Philip E

2011-06-03

232

Analysis of a scaling rate meter for geothermal systems  

SciTech Connect

A research project was conducted to investigate an experimental technique for measuring the rate of formation of mineral scale and corrosion in geothermal systems. A literature review was performed first to identify and evaluate available techniques for measuring scale in heat transfer equipment. As a result of these evaluations, a conceptual design was proposed for a geothermal Scaling Rate Meter (SRM) that would combine features of certain techniques used (or proposed for use) in other applications. An analysis was performed to predict the steady-state performance and expected experimental uncertainty of the proposed SRM. Sample computations were then performed to illustrate the system performance for conditions typical of a geothermal scaling application. Based on these results, recommendations are made regarding prototype SRM construction and testing.

Kreid, D.K.

1980-03-01

233

Rasch Analysis of the Fullerton Advanced Balance (FAB) Scale  

PubMed Central

ABSTRACT Purpose: This cross-sectional study explores the psychometric properties and dimensionality of the Fullerton Advanced Balance (FAB) Scale, a multi-item balance test for higher-functioning older adults. Methods: Participants (n=480) were community-dwelling adults able to ambulate independently. Data gathering consisted of survey and balance performance assessment. Psychometric properties were assessed using Rasch analysis. Results: Mean age of participants was 76.4 (SD=7.1) years. Mean FAB Scale scores were 24.7/40 (SD=7.5). Analyses for scale dimensionality showed that 9 of the 10 items fit a unidimensional measure of balance. Item 10 (Reactive Postural Control) did not fit the model. The reliability of the scale to separate persons was 0.81 out of 1.00; the reliability of the scale to separate items in terms of their difficulty was 0.99 out of 1.00. Cronbach's alpha for a 10-item model was 0.805. Items of differing difficulties formed a useful ordinal hierarchy for scaling patterns of expected balance ability scoring for a normative population. Conclusion: The FAB Scale appears to be a reliable and valid tool to assess balance function in higher-functioning older adults. The test was found to discriminate among participants of varying balance abilities. Further exploration of concurrent validity of Rasch-generated expected item scoring patterns should be undertaken to determine the test's diagnostic and prescriptive utility.

Fiedler, Roger C.; Rose, Debra J.

2011-01-01

234

Multi-dimensional Likelihood Estimation Techniques in conjunction with the Method of Anchored Distributions (MAD)  

NASA Astrophysics Data System (ADS)

The method of anchored distributions (MAD, Rubin et al., Water Resour. Res., 2010) is a Bayesian inversion technique that combines geostatistical concepts with a strategy for localization of data that is indirectly related to the target variables, using anchors. Anchors are statistical distributions of the target variables (e.g., the hydraulic conductivity) at specific locations The variable field is described by the statistical distributions of structural parameters that characterize global features and by anchor distributions that intend to capture local effects. The posterior distributions of structural and anchor parameter sets are used to update the approximate spatial distribution of target variable and are generated by re-sampling the parameter sets using their normalized likelihood estimates as the probability of being selected. Increasing the dimension of the data, to include additional information in the likelihood estimate, increases the computational burden. Two measures are taken to accommodate the advantageous additional data without spurious side effects. (1) Partitioning parameter sets into hypercubes, based upon the similarity of the structural parameter values. (2) Principal component analysis, to reduce the dimensionality by discarding a certain percentage of principal components. As an additional feature for large sample sets, or faster calculation, a ‘bundling’ regime can be implemented. Bundling is employed immediately after partitioning the parameter sets into hypercubes. Bundling identifies spatial patterns amongst the realizations generated from the distributions defining the anchor parameters. The added organizational step allows data with reduced sample sizes to be passed to the PCA algorithm. The division of the data set allows for simple parallelization of the computation and our case study achieved a three-fold dimension reduction. Because of the high dimension involved in the calculation, without absurdly large sample sizes, it is reasonable to assume that the data sparsely populates the hyperspace. In order to avoid using an interpolation scheme that would average and smooth the likelihood distribution over extensive regions of unpopulated hyperspace, the data is scanned for clusters using the HOPACH algorithm authored by M. Van der Laan. The density is estimated, over the clusters, non-parametrically. The cluster approximations are summed up using a mixture model to achieve the final likelihood estimate.

Over, M. W.; Murakami, H.; Hahn, M. S.; Yang, Y.; Rubin, Y.

2010-12-01

235

Validation of inelastic analysis by full-scale component testing  

Microsoft Academic Search

This paper compares theoretical and experimental results for full-scale, prototypical components tested at elevated-temperatures to provide validation for inelastic analysis methods, material models, and design limits. Results are discussed for piping elbow plastic and creep buckling, creep ratcheting, and creep relaxation; nozzle creep ratcheting and weld cracking; and thermal striping fatigue. Comparisons between theory and test confirm the adequacy of

D. S. Griffin; A. K. Dhalla; W. S. Woodward

1987-01-01

236

Exploratory Factor Analysis of African Self-Consciousness Scale Scores  

ERIC Educational Resources Information Center

|This study replicates and extends prior studies of the dimensionality, convergent, and external validity of African Self-Consciousness Scale scores with appropriate exploratory factor analysis methods and a large gender balanced sample (N = 348). Viable one- and two-factor solutions were cross-validated. Both first factors overlapped…

Bhagwat, Ranjit; Kelly, Shalonda; Lambert, Michael C.

2012-01-01

237

A Confirmatory Factor Analysis of the Professional Opinion Scale  

ERIC Educational Resources Information Center

|The Professional Opinion Scale (POS) was developed to measure social work values orientation. Objective: A confirmatory factor analysis was performed on the POS. Method: This cross-sectional study used a mailed survey design with a national random (simple) sample of members of the National Association of Social Workers. Results: The study…

Greeno, Elizabeth J.; Hughes, Anne K.; Hayward, R. Anna; Parker, Karen L.

2007-01-01

238

DESIGN AND ANALYSIS OF A MESO-SCALE REFRIGERATOR  

Microsoft Academic Search

The preliminary design and analysis of a meso-scale refrigerator is presented here. The device is to be designed out of layers of silicon wafers bonded together and is to be fabricated through the techniques of microelectronics. The intended application of the device is an integrated heat removal system for electronics or photonic chips or modules. The paper presents a functional

N. S. Ashraf; H. C. Carter; K. Casey; S. Corban; M. K. Drost; A. J. Gumm; J. S. Kapat; L. Kramer; M. Newton; J. Vaidya; C. C. Wong; K. Yerkes

239

The Multidimensional Fear of Death Scale: An independent analysis  

Microsoft Academic Search

The factor structure and subscale reliabilities of the Multidimensional Fear of Death Scale were examined using the responses of 256 New Zealanders, predominantly undergraduates. Comparison with the results of a US study by J. W. Hoelter showed that both the subscale reliabilities and the factor structure were almost perfectly reproduced in the present analysis. Hoelter's claim of 8 effectively independent

Frank H. Walkey

1982-01-01

240

Taxometric Analysis of the Levenson Self-Report Psychopathy Scale  

Microsoft Academic Search

Levenson's Self-Report Psychopathy scale (Levenson, Kiehl, & Fitzpatrick, 1995) was administered to 1,972 male and female federal prison inmates, the results of which were subjected to taxometric analysis. We employed 4 taxometric procedures in this study: mean above minus below a cut (Meehl & Yonce, 1994), maximum slope (Grove & Meehl, 1993), maximum eigenvalue (Waller & Meehl, 1998), and latent-mode

Glenn D. Walters; Chad A. Brinkley; Philip R. Magaletta; Pamela M. Diamond

2008-01-01

241

Development of a multi-dimensional health assessment questionnaire (MDHAQ) for the infrastructure of standard clinical care.  

PubMed

The HAQ has become the pre-eminent patient questionnaire used in rheumatology. It is easily completed by patients, but not easily reviewed and scored in standard clinical care and has some minor psychometric limitations, as do all questionnaires. Modifications of the HAQ been made to facilitate use in standard care, particularly to include 8-10 activities of daily living, along with scores for pain and global status and other information on one side of one page for rapid review by the clinician. A patient questionnaire for standard care should be limited to 2 sides of 1 page, in a format amenable to "eyeball" review by the clinician in 5 seconds or less. It can be scored formally in 15-20 seconds or less, and is useful in patients with all rheumatic diseases. The current version of a multi-dimensional HAQ (MDHAQ) includes scoring templates on the questionnaire to allow formal scoring in less than 15 seconds by a rheumatologist or an assistant, for possible entry onto a paper and/or computerized flow sheet. Various versions of the MDHAQ may also include a "constant" region of physical function, pain and patient global status, and "variable" regions of fatigue, morning stiffness, psychological distress, change in status, a review of systems, a rheumatoid arthritis disease activity self-report joint count (RADAI), review of recent health events, and review of medications. The MDHAQ can be used in the infrastructure of rheumatology care to include quantitative data in standard care of all patients with all rheumatic diseases. PMID:16273781

Pincus, T; Yazici, Y; Bergman, M

242

Multiconfiguration time-dependent Hartree (MCTDH): An efficient method for propagating multi-dimensional wavepackets and density operators.  

NASA Astrophysics Data System (ADS)

The multiconfiguration time-dependent Hartree (MCTDH) method is an algorithm for propagating multi-dimensional wavepackets [U. Manthe, H.-D. Meyer, and L. S. Cederbaum, J. Chem. Phys. 97, 3199 (1992); M. H. Beck, A. J"akle, G. A. Worth, and H.-D. Meyer, Phys. Rep. 324, 1 (2000)] or density operators [A. Raab and H.-D. Meyer, J. Chem. Phys. 112, 10718 (2000)]. This algorithm is briefly introduced and its efficiency is explained. In short, the efficiency originates from using an variationally optimized time-dependent basis set. The efficiency of MCTDH is best demonstrated through the calculations on the absorption spectrum of pyrazine. There the correlated motion of all the 24 modes evolving on two coupled electronic surfaces is treated with high accuracy [G. Worth, H.-D. Meyer, and L. S. Cederbaum, J. Chem. Phys. 109, 3518 (1998); A. Raab, G. Worth, H.-D. Meyer, and L. S. Cederbaum, J. Chem. Phys. 110, 936 (1999)]. To emphasize the very large gain obtained here we note that the underlying primitive basis consists of 10^21 points, whereas there are only 3.8 x 10^6 configurations are needed for convergence. MCTDH has been applied to a wide range of molecular processes, including photodissociation, surface scattering, reactive scattering and the computation of vibrational spectra. Recently MCTDH has been used to study the well known spin-boson model [H. Wang, J. Chem. Phys. 113, 9948 (2000)], including up to 80 vibrational modes. The present talk will discuss an application of MCTDH to a high dimensional spin system. Further information on MCTDH can be found on the web site http://www.pci.uni-heidelberg.de/tc/usr/mctdh/

Meyer, Hans-Dieter

2003-03-01

243

Quantitative analysis of scale of aeromagnetic data raises questions about geologic-map scale  

USGS Publications Warehouse

A recently published study has shown that small-scale geologic map data can reproduce mineral assessments made with considerably larger scale data. This result contradicts conventional wisdom about the importance of scale in mineral exploration, at least for regional studies. In order to formally investigate aspects of scale, a weights-of-evidence analysis using known gold occurrences and deposits in the Central Lapland Greenstone Belt of Finland as training sites provided a test of the predictive power of the aeromagnetic data. These orogenic-mesothermal-type gold occurrences and deposits have strong lithologic and structural controls associated with long (up to several kilometers), narrow (up to hundreds of meters) hydrothermal alteration zones with associated magnetic lows. The aeromagnetic data were processed using conventional geophysical methods of successive upward continuation simulating terrane clearance or 'flight height' from the original 30 m to an artificial 2000 m. The analyses show, as expected, that the predictive power of aeromagnetic data, as measured by the weights-of-evidence contrast, decreases with increasing flight height. Interestingly, the Moran autocorrelation of aeromagnetic data representing differing flight height, that is spatial scales, decreases with decreasing resolution of source data. The Moran autocorrelation coefficient scems to be another measure of the quality of the aeromagnetic data for predicting exploration targets. ?? Springer Science+Business Media, LLC 2007.

Nykanen, V.; Raines, G. L.

2006-01-01

244

Lévy scaling: The diffusion entropy analysis applied to DNA sequences  

NASA Astrophysics Data System (ADS)

We address the problem of the statistical analysis of a time series generated by complex dynamics with the diffusion entropy analysis (DEA) [N. Scafetta, P. Hamilton, and P. Grigolini, Fractals 9, 193 (2001)]. This method is based on the evaluation of the Shannon entropy of the diffusion process generated by the time series imagined as a physical source of fluctuations, rather than on the measurement of the variance of this diffusion process, as done with the traditional methods. We compare the DEA to the traditional methods of scaling detection and prove that the DEA is the only method that always yields the correct scaling value, if the scaling condition applies. Furthermore, DEA detects the real scaling of a time series without requiring any form of detrending. We show that the joint use of DEA and variance method allows to assess whether a time series is characterized by Lévy or Gauss statistics. We apply the DEA to the study of DNA sequences and prove that their large-time scales are characterized by Lévy statistics, regardless of whether they are coding or noncoding sequences. We show that the DEA is a reliable technique and, at the same time, we use it to confirm the validity of the dynamic approach to the DNA sequences, proposed in earlier work.

Scafetta, Nicola; Latora, Vito; Grigolini, Paolo

2002-09-01

245

SINEX: SCALE shielding analysis GUI for X-Windows  

SciTech Connect

SINEX (SCALE Interface Environment for X-windows) is an X-Windows graphical user interface (GUI), that is being developed for performing SCALE radiation shielding analyses. SINEX enables the user to generate input for the SAS4/MORSE and QADS/QAD-CGGP shielding analysis sequences in SCALE. The code features will facilitate the use of both analytical sequences with a minimum of additional user input. Included in SINEX is the capability to check the geometry model by generating two-dimensional (2-D) color plots of the geometry model using a new version of the SCALE module, PICTURE. The most sophisticated feature, however, is the 2-D visualization display that provides a graphical representation on screen as the user builds a geometry model. This capability to interactively build a model will significantly increase user productivity and reduce user errors. SINEX will perform extensive error checking and will allow users to execute SCALE directly from the GUI. The interface will also provide direct on-line access to the SCALE manual.

Browman, S.M.; Barnett, D.L.

1997-12-01

246

Establishment and assessment of code scaling capability  

Microsoft Academic Search

In this thesis, a method for using RELAP5\\/MOD3.3 (Patch03) code models is described to establish and assess the code scaling capability and to corroborate the scaling methodology that has been used in the design of the Purdue University Multi-Dimensional Integral Test Assembly for ESBWR applications (PUMA-E) facility. It was sponsored by the United States Nuclear Regulatory Commission (USNRC) under the

Jaehyok Lim

2009-01-01

247

Language pyramid and multi-scale text analysis  

Microsoft Academic Search

The classical Bag-of-Word (BOW) model represents a document as a histogram of word occurrence, losing the spatial information that is invaluable for many text analysis tasks. In this paper, we present the Language Pyramid (LaP) model, which casts a document as a probabilistic distribution over the joint semantic-spatial space and motivates a multi-scale 2D local smoothing framework for nonparametric text

Shuang-Hong Yang; Hongyuan Zha

2010-01-01

248

Crime Analysis at Multiple Scales of Aggregation: A Topological Approach  

Microsoft Academic Search

Patterns in crime vary quite substantially at different scales of aggregation, in part because data tend to be organized around\\u000a standardized, artificially defined units of measurement such as the census tract, the city boundary, or larger administrative\\u000a or political boundaries. The boundaries that separate units of data often obscure the detailed spatial patterns and muddy\\u000a analysis. These aggregation units have

Patricia L. Brantingham; Paul J. Brantingham; Mona Vajihollahi; Kathryn Wuschke

249

GAIN Working Papers: Rasch Analysis of the Substance Problem Scale  

Microsoft Academic Search

Purpose. The purpose of this report is to provide a brief psychometric analysis of the Substance Problem Scale - past year (SPSpy) using the Rasch measurement model. The SPSpy consists of 16 past-year yes\\/no items (alpha=.89) related to any alcohol or drug use disorders, including abuse, dependence, and substance induced health and psychiatric problems. Methods. Data were analyzed on 7,435

Kendon J. Conrad; Karen M. Conrad; Michael L. Dennis; Barth B. Riley

250

Global-scale analysis of the mantle Pds phases  

Microsoft Academic Search

A global-scale analysis of travel times of the mantle Pds phases (converted from P to S from the discontinuity at a depth d beneath the receiver) is presented. Most of the data are related to P'410's and P'660's, recorded by the broadband stations of Geoscope, Incorporated Research Institutions for Seismology (IRIS) and other networks. In order to provide a good

Sébastien Chevrot; Lev Vinnik; Jean-Paul Montagner

1999-01-01

251

Early analysis of chip scale package design trade-offs  

Microsoft Academic Search

Chip scale packages (CSPs) present new challenges for both package designer and package user. It is possible to make package design trade-offs between package size, I\\/O pattern, thermal\\/electrical performance and cost for a given IC. An ideal set of CSP design trade-offs for one application may be a poor selection for another. Early analysis tools give technical information needed to

W. Blood; A. Lai

1998-01-01

252

Bicoherence analysis of model-scale jet noise.  

PubMed

Bicoherence analysis has been used to characterize nonlinear effects in the propagation of noise from a model-scale, Mach-2.0, unheated jet. Nonlinear propagation effects are predominantly limited to regions near the peak directivity angle for this jet source and propagation range. The analysis also examines the practice of identifying nonlinear propagation by comparing spectra measured at two different distances and assuming far-field, linear propagation between them. This spectral comparison method can lead to erroneous conclusions regarding the role of nonlinearity when the observations are made in the geometric near field of an extended, directional radiator, such as a jet. PMID:21110528

Gee, Kent L; Atchley, Anthony A; Falco, Lauren E; Shepherd, Micah R; Ukeiley, Lawrence S; Jansen, Bernard J; Seiner, John M

2010-11-01

253

Quantitative analysis of scale sensitivity in geographic cellular automata  

NASA Astrophysics Data System (ADS)

Geographical Cellular Automata (GCA) approach is based on complexity theory and is widely used in geospatial modeling. A reason for the increasing attention given to GCA models is that they can easily be integrated with rasterbased GIS environment. However, the behavior of the GCA models is affected by uncertainties arising from the interaction between model elements, structures, and the quality of data sources used as model input. The objective of this study is to examine the impacts of model elements on the generated outputs of a GIS-based GCA land-use growth model using sensitivity analysis (SA) approach. The proposed SA method consists of KAPPA index with different spatial metrics. A stochastic GCA model was built to model land use change in the changsha region (Hunan,China). The transition rules were empirically derived from four Landsat-TM (30m resolution) images taken in 1996,1999, 2002 and 2005 that have been resampled to four resolutions (30, 60, 90, 120m). Five different neighbourhood configurations were considered (Moore, Von Neumann, and circular approximations of 2, 3 and 4 cell radii). Simulations were performed for each of the twenty spatial scale scenarios. Results show that spatial scale has a considerable impact on simulation dynamics in terms of both land use area and spatial structure. The spatial scale domains present in the results reveal the nonlinear relationships that link the spatial scale components to the simulation results.

Zhang, Honghui; Zeng, Yongnian; Yin, Changlin; Jin, Xiaobin; Chen, Guanghui; You, Shenjin; Zou, Bin

2008-11-01

254

Assessing the Primary Schools--A Multi-Dimensional Approach: A School Level Analysis Based on Indian Data  

ERIC Educational Resources Information Center

|Primary education is essential for the economic development in any country. Most studies give more emphasis to the final output (such as literacy, enrolment etc.) rather than the delivery of the entire primary education system. In this paper, we study the school level data from an Indian district, collected under the official DISE statistics. We…

Sengupta, Atanu; Pal, Naibedya Prasun

2012-01-01

255

Final Topical Report, ''Multi-Dimensional Analysis of the Forced Bubble Dynamics Associated with Bubble Fusion Phenomena''  

SciTech Connect

A new adaptive grid, 3-D FEM hydrodynamic shock (ie, HYDRO )code called PHASTA-2C has been developed and used to investigate bubble implosion phenomena leading to ultra-high temperatures and pressures. In particular, it was shown that nearly spherical bubble compressions occur during bubble implosions and the predicted conditions associated with a recent ORNL Bubble Fusion experiment [Taleyarkhan et al, Science, March, 2002] are consistent with the occurrence of D/D fusion.

Richard T. Lahey, Jr. - PI Kenneth E. Jansen - COPI Sunitha Nagrath - Graduate Student

2002-12-02

256

Analysis of multi-dimensional SAR for determining the thickness of thin sea ice in the Bohai Sea  

NASA Astrophysics Data System (ADS)

Flat thin ice (<30 cm thick) is a common ice type in the Bohai Sea, China. Ice thickness detection is important to offshore exploration and marine transport in winter. Synthetic aperture radar (SAR) can be used to acquire sea ice data in all weather conditions, and it is a useful tool for monitoring sea ice conditions. In this paper, we combine a multi-layered sea ice electromagnetic (EM) scattering model with a sea ice thermodynamic model to assess the determination of the thickness of flat thin ice in the Bohai Sea using SAR at different frequencies, polarization, and incidence angles. Our modeling studies suggest that co-polarization backscattering coefficients and the co-polarized ratio can be used to retrieve the thickness of flat thin ice from C- and X-band SAR, while the co-polarized correlation coefficient can be used to retrieve flat thin ice thickness from L-, C-, and X-band SAR. Importantly, small or moderate incidence angles should be chosen to avoid the effect of speckle noise.

Zhang, Xi; Zhang, Jie; Meng, Junmin; Su, Tengfei

2013-05-01

257

Multi-dimensional finite element code for the analysis of coupled fluid energy, and solute transport (CFEST)  

SciTech Connect

The Seasonal Thermal Energy Storage Program is being conducted for the Department of Energy by Pacific Northwest Laboratory. A major thrust of this program has been the study of natural aquifers as hosts for thermal energy storage and retrieval. Numerical simulation of the nonisothermal response of the host media is fundamental to the evaluation of proposed experimental designs and field test results. This report represents the primary documentation for the coupled fluid, energy and solute transport (CFEST) code. Sections of this document are devoted to the conservation equations and their numerical analogues, the input data requirements, and the verification studies completed to date.

Gupta, S.K.; Kincaid, C.T.; Meyer, P.R.; Newbill, C.A.; Cole, C.R.

1982-08-01

258

Multi-scale data fusion using Multiresolution Variational Analysis (MRVA)  

NASA Astrophysics Data System (ADS)

Geophysical data tend to be heterogeneous in measurement characteristics and irregularly sampled over space and time. For example, in satellite remote sensing of the sea surface temperature, the microwave (MW) sensors have typically coarser 25-km resolution than the infra-red (IR) sensors which can resolve down to a 1-km scale. However, the MW sensors are less prone to cloud contamination which affects the IR data and leads to data voids. Moreover, geostationary satellites have fine temporal resolutions but cover limited geographical regions, while orbiting satellites can have global coverages by compromising temporal sampling. To merge such data sets with drastically different spatial resolution and coverage into a coherent reconstruction of the geophysical field, the multiresolution variational analysis (MRVA) method has been used. MRVA is a hybrid of the variational interpolation technique used commonly in meteorology and oceanography and multiresolution analysis (MRA) technique known for wavelet-based orthonormal signal transformation. Apparent advantages of MRVA include: (1) the interpolation scale (correlation scale) can be optimized for each input data set; (2) inter-sensor bias corrections are facilitated; (3) the spectral characteristics (e.g., power law) of the output can be controlled to match a desired specification. These are demonstrated with remote sensing data for the sea surface temperature and wind.

Chin, T. M.

2012-04-01

259

Reactor Physics Methods and Analysis Capabilities in SCALE  

SciTech Connect

The TRITON sequence of the SCALE code system provides a powerful, robust, and rigorous approach for performing reactor physics analysis. This paper presents a detailed description of TRITON in terms of its key components used in reactor calculations. The ability to accurately predict the nuclide composition of depleted reactor fuel is important in a wide variety of applications. These applications include, but are not limited to, the design, licensing, and operation of commercial/research reactors and spent-fuel transport/storage systems. New complex design projects such as next-generation power reactors and space reactors require new high-fidelity physics methods, such as those available in SCALE/TRITON, that accurately represent the physics associated with both evolutionary and revolutionary reactor concepts as they depart from traditional and well-understood light water reactor designs.

Mark D. DeHart; Stephen M. Bowman

2011-05-01

260

Histogram analysis using a scale-space approach.  

PubMed

A new application of scale-space filtering to the classical problem of estimating the parameters of a normal mixture distribution is described. The technique involves generating a multiscale description of a histogram by convolving it with a series of Gaussians of gradually increasing width (standard deviation), and marking the location and direction of the sign change of zero-crossings in the second derivative. The resulting description, or fingerprint, is interpreted by relating pairs of zero-crossings to modes in the histogram where each mode or component is modeled by a normal distribution. Zero-crossings provide information from which estimates of the mixture parameters are computed. These initial estimates are subsequently refined using an iterative maximum likelihood estimation technique. Varying the scale or resolution of the analysis allows the number of components used in approximating the histogram to be controlled. PMID:21869382

Carlotto, M J

1987-01-01

261

Analytic scaling analysis of high harmonic generation conversion efficiency.  

PubMed

Closed form expressions for the high harmonic generation (HHG) conversion efficiency are obtained for the plateau and cutoff regions. The presented formulas eliminate most of the computational complexity related to HHG simulations, and enable a detailed scaling analysis of HHG efficiency as a function of drive laser parameters and material properties. Moreover, in the total absence of any fitting procedure, the results show excellent agreement with experimental data reported in the literature. Thus, this paper opens new pathways for the global optimization problem of extreme ultraviolet (EUV) sources based on HHG. PMID:19550522

Falcão-Filho, E L; Gkortsas, M; Gordon, Ariel; Kärtner, Franz X

2009-06-22

262

Flux Coupling Analysis of Genome-Scale Metabolic Network Reconstructions  

PubMed Central

In this paper, we introduce the Flux Coupling Finder (FCF) framework for elucidating the topological and flux connectivity features of genome-scale metabolic networks. The framework is demonstrated on genome-scale metabolic reconstructions of Helicobacter pylori, Escherichia coli, and Saccharomyces cerevisiae. The analysis allows one to determine whether any two metabolic fluxes, v1 and v2, are (1) directionally coupled, if a non-zero flux for v1 implies a non-zero flux for v2 but not necessarily the reverse; (2) partially coupled, if a non-zero flux for v1 implies a non-zero, though variable, flux for v2 and vice versa; or (3) fully coupled, if a non-zero flux for v1 implies not only a non-zero but also a fixed flux for v2 and vice versa. Flux coupling analysis also enables the global identification of blocked reactions, which are all reactions incapable of carrying flux under a certain condition; equivalent knockouts, defined as the set of all possible reactions whose deletion forces the flux through a particular reaction to zero; and sets of affected reactions denoting all reactions whose fluxes are forced to zero if a particular reaction is deleted. The FCF approach thus provides a novel and versatile tool for aiding metabolic reconstructions and guiding genetic manipulations.

Burgard, Anthony P.; Nikolaev, Evgeni V.; Schilling, Christophe H.; Maranas, Costas D.

2004-01-01

263

Diagnostic accuracy of the International HIV Dementia Scale and HIV Dementia Scale: A meta-analysis  

PubMed Central

This aim of this study was to assess the diagnostic accuracy of the International HIV Dementia Scale (IHDS) or HIV Dementia Scale (HDS) for the diagnosis of HIV-associated neurocognitive disorders (HAND). A comprehensive and systematic search was carried out in PubMed and EMBASE databases. Sensitivity, specificity, Q*-values, summary receiver operating characteristic curves and other measures of accuracy of IHDS or HDS in the diagnosis of HAND were summarized. Summary receiver operator characteristic (SROC) curve analysis for HAND data demonstrates a pooled sensitivity of 0.90 [95% confidence interval (CI), 0.88–0.91] and overall specificity of 0.96 (95% CI, 0.95–0.97) for IHDS, the Q*-value for IHDS was 0.9195 and the diagnostic odds ratio (DOR) was 162.28 (95% CI, 91.82–286.81). HDS had an overall sensitivity of 0.39 (95% CI, 0.34–0.43) and specificity of 0.90 (95% CI, 0.89–0.91), the Q*-value for HDS was 0.6321 and DOR was 5.81 (95% CI, 3.64–9.82). There was significant heterogeneity for studies that reported IHDS and HDS. This meta-analysis has shown that IHDS and HDS may offer high diagnostic performance accuracy for the detection of HAND in primary health care and resource-limited settings. IHDS and HDS may require reformed neuropsychological characterization of impairments in accordance with regional culture and language in future international studies.

HU, XUEYING; ZHOU, YANG; LONG, JIANXIONG; FENG, QIMING; WANG, RENSHENG; SU, LI; ZHAO, TINGTING; WEI, BO

2012-01-01

264

Application of multi-dimensional discrimination diagrams and probability calculations to Paleoproterozoic acid rocks from Brazilian cratons and provinces to infer tectonic settings  

NASA Astrophysics Data System (ADS)

In present work, we applied two sets of new multi-dimensional geochemical diagrams (Verma et al., 2013) obtained from linear discriminant analysis (LDA) of natural logarithm-transformed ratios of major elements and immobile major and trace elements in acid magmas to decipher plate tectonic settings and corresponding probability estimates for Paleoproterozoic rocks from Amazonian craton, São Francisco craton, São Luís craton, and Borborema province of Brazil. The robustness of LDA minimizes the effects of petrogenetic processes and maximizes the separation among the different tectonic groups. The probability based boundaries further provide a better objective statistical method in comparison to the commonly used subjective method of determining the boundaries by eye judgment. The use of readjusted major element data to 100% on an anhydrous basis from SINCLAS computer program, also helps to minimize the effects of post-emplacement compositional changes and analytical errors on these tectonic discrimination diagrams. Fifteen case studies of acid suites highlighted the application of these diagrams and probability calculations. The first case study on Jamon and Musa granites, Carajás area (Central Amazonian Province, Amazonian craton) shows a collision setting (previously thought anorogenic). A collision setting was clearly inferred for Bom Jardim granite, Xingú area (Central Amazonian Province, Amazonian craton) The third case study on Older São Jorge, Younger São Jorge and Maloquinha granites Tapajós area (Ventuari-Tapajós Province, Amazonian craton) indicated a within-plate setting (previously transitional between volcanic arc and within-plate). We also recognized a within-plate setting for the next three case studies on Aripuanã and Teles Pires granites (SW Amazonian craton), and Pitinga area granites (Mapuera Suite, NW Amazonian craton), which were all previously suggested to have been emplaced in post-collision to within-plate settings. The seventh case studies on Cassiterita-Tabuões, Ritápolis, São Tiago-Rezende Costa (south of São Francisco craton, Minas Gerais) showed a collision setting, which agrees fairly reasonably with a syn-collision tectonic setting indicated in the literature. A within-plate setting is suggested for the Serrinha magmatic suite, Mineiro belt (south of São Francisco craton, Minas Gerais), contrasting markedly with the arc setting suggested in the literature. The ninth case study on Rio Itapicuru granites and Rio Capim dacites (north of São Francisco craton, Serrinha block, Bahia) showed a continental arc setting. The tenth case study indicated within-plate setting for Rio dos Remédios volcanic rocks (São Francisco craton, Bahia), which is compatible with these rocks being the initial, rift-related igneous activity associated with the Chapada Diamantina cratonic cover. The eleventh, twelfth and thirteenth case studies on Bom Jesus-Areal granites, Rio Diamante-Rosilha dacite-rhyolite and Timbozal-Cantão granites (São Luís craton) showed continental arc, within-plate and collision settings, respectively. Finally, the last two case studies, fourteenth and fifteenth showed a collision setting for Caicó Complex and continental arc setting for Algodões (Borborema province).

Verma, Sanjeet K.; Oliveira, Elson P.

2013-08-01

265

The effect of temporal observation scale on extreme rainfall analysis  

NASA Astrophysics Data System (ADS)

Mediterranean storms usually show high intensity and irregularity of rainfall. A single torrential event can double, even triplicate, the average annual rainfall. These features, in turn, determine rainfall-runoff conversion and other hydrological processes. As a consequence flash-floods and hydrological behaviour of ephemeral streams are dominated by these extreme events. However the internal structure of storms varies according to the time scale at which data are collected. As the observation interval is reduced, intensity becomes more significant and emphasizes the concentrated character of the precipitation. Moreover, an equivalent amount of rainfall, registered at different time scales, can result in different rainfall spatial patterns, and it can help to indentify which factors are important at each time measurement scale. This paper analyzes the temporal and spatial variations of rainfall pattern, associated with different time scales in data collection. The study area involves the whole territory of the River Júcar Water Authority. This area covers a surface of 43.000 km2, and shows different geographical features (topography ranking from 2000 to 0 m, sea influence, inland and coastal territories, different exposure to wet winds, etc....). Rainfall data are collected, every five minutes, by the Automatic Hydrological Information System (SAIH), from 147 rain gauges, covering a 13 years continuous period (1994-2007). Precipitation data have been rescaling in order to obtain rainfall parameters every five minutes, 15 minutes, 30 minutes, 1 hour, 6 hours, 12 hours and 24 hours. Indicators of cumulative rainfall, maximum intensity, irregularity, probability of rain and persistence of rain have been estimated for every time scale. From a time scale perspective, results show that there are two variables, "cumulative rainfall" and "probability of rain", that follow a positive logarithmic trend, time-dependent. "Cumulative rainfall" shows a change of trend at 6 hours time scale, while the variable "probability of rain" changes its trend after 1 hour. Variables of "maximum intensity", "irregularity" and "persistence of rain" show negative trends, fitting power curves functions time-dependent. All of these variables show a change of trend after 1 hour. Regarding the spatial pattern of these variables qualitative analysis have been made. Result show changes in the factors influencing this pattern, depending on the length of the measurement time interval. Thus, for the variables of "cumulative rainfall" and "maximum intensity", increasing time interval implies a reduction of the area affected by the maximum values. Moreover, in the interval of 5 minutes the factor altitude is determinant, while for longer time intervals, factors as distance to the sea and the orographic structures exposure to wet dominant winds gain importance. The "irregularity" shows, for 5 minutes, the highest values in the plains near the sea, (exposed to wind of component E) and in the first line of relief or valleys opened to the sea (which acts as a trigger of instability). As the time interval increases, other factors, as distance to the sea, the effect of a second inland alignment of relieves, and the exposure to wet wind of component NE, become important. Concerning the "probability of rain" the interval of five minutes, shows the importance of exposure to wet winds of component NE plus the effect of the relief as a trigger. As the time interval increases, the presence of mountainous area in combination with wind of component W acquires prominence. The "persistence of rain" is related to the distance to the sea from the first mountainous alignments and to the exposure to winds of components NE and SE. As the time interval increases the persistence of higher values are reduced to the area exposed to winds of component NE in combination with the effect of the relief as a trigger. Finally, although the results are preliminary, author

Camarasa, A. M.; Soriano, J.

2009-09-01

266

Reliability analysis of a utility-scale solar power plant  

SciTech Connect

This paper presents the results of a reliability analysis for a solar central receiver power plant that employs a salt-in-tube receiver. Because reliability data for a number of critical plant components have only recently been collected, this is the first time a credible analysis can be performed. This type of power plant will be built by a consortium of western US utilities led by the Southern California Edison Company. The 10 MW plant is known as Solar Two and is scheduled to be on-line in 1994. It is a prototype which should lead to the construction of 100 MW commercial-scale plants by the year 2000. The availability calculation was performed with the UNIRAM computer code. The analysis predicted a forced outage rate of 5.4% and an overall plant availability, including scheduled outages, of 91%. The code also identified the most important contributors to plant unavailability. Control system failures were identified as the most important cause of forced outages. Receiver problems were rated second with turbine outages third. The overall plant availability of 91% exceeds the goal identified by the US utility study. This paper discuses the availability calculation and presents evidence why the 91% availability is a credible estimate. 16 refs.

Kolb, G.J.

1992-01-01

267

Reliability analysis of a utility-scale solar power plant  

SciTech Connect

This paper presents the results of a reliability analysis for a solar central receiver power plant that employs a salt-in-tube receiver. Because reliability data for a number of critical plant components have only recently been collected, this is the first time a credible analysis can be performed. This type of power plant will be built by a consortium of western US utilities led by the Southern California Edison Company. The 10 MW plant is known as Solar Two and is scheduled to be on-line in 1994. It is a prototype which should lead to the construction of 100 MW commercial-scale plants by the year 2000. The availability calculation was performed with the UNIRAM computer code. The analysis predicted a forced outage rate of 5.4% and an overall plant availability, including scheduled outages, of 91%. The code also identified the most important contributors to plant unavailability. Control system failures were identified as the most important cause of forced outages. Receiver problems were rated second with turbine outages third. The overall plant availability of 91% exceeds the goal identified by the US utility study. This paper discuses the availability calculation and presents evidence why the 91% availability is a credible estimate. 16 refs.

Kolb, G.J.

1992-08-01

268

Reliability analysis of a utility-scale solar power plant  

NASA Astrophysics Data System (ADS)

This paper presents the results of a reliability analysis for a solar central receiver power plant that employs a salt-in-tube receiver. Because reliability data for a number of critical plant components have only recently been collected, this is the first time a credible analysis can be performed. This type of power plant will be built by a consortium of western US utilities led by the Southern California Edison Company. The 10 MW plant is known as Solar Two and is scheduled to be on-line in 1994. It is a prototype which should lead to the construction of 100 MW commercial-scale plants by the year 2000. The availability calculation was performed with the UNIRAM computer code. The analysis predicted a forced outage rate of 5.4 percent and an overall plant availability, including scheduled outages, of 91 percent. The code also identified the most important contributors to plant unavailability. Control system failures were identified as the most important cause of forced outages. Receiver problems were rated second with turbine outages third. The overall plant availability of 91 percent exceeds the goal identified by the US utility study. This paper discuses the availability calculation and presents evidence why the 91 percent availability is a credible estimate.

Kolb, G. J.

1992-10-01

269

Metal Analysis of Scales Taken from Arctic Grayling  

Microsoft Academic Search

This study examined concentrations of metals in fish scales taken from Arctic grayling using laser ablation-induc- tively coupled plasma mass spectrometry (LA-ICPMS). The purpose was to assess whether scale metal concentrations re- flected whole muscle metal concentrations and whether the spatial distribution of metals within an individual scale varied among the growth annuli of the scales. Ten elements (Mg, Ca,

A. P. Farrell; A. H. Hodaly; S. Wang

270

Anomaly Detection in Multiple Scale for Insider Threat Analysis  

SciTech Connect

We propose a method to quantify malicious insider activity with statistical and graph-based analysis aided with semantic scoring rules. Different types of personal activities or interactions are monitored to form a set of directed weighted graphs. The semantic scoring rules assign higher scores for the events more significant and suspicious. Then we build personal activity profiles in the form of score tables. Profiles are created in multiple scales where the low level profiles are aggregated toward more stable higherlevel profiles within the subject or object hierarchy. Further, the profiles are created in different time scales such as day, week, or month. During operation, the insider s current activity profile is compared to the historical profiles to produce an anomaly score. For each subject with a high anomaly score, a subgraph of connected subjects is extracted to look for any related score movement. Finally the subjects are ranked by their anomaly scores to help the analysts focus on high-scored subjects. The threat-ranking component supports the interaction between the User Dashboard and the Insider Threat Knowledge Base portal. The portal includes a repository for historical results, i.e., adjudicated cases containing all of the information first presented to the user and including any additional insights to help the analysts. In this paper we show the framework of the proposed system and the operational algorithms.

Kim, Yoohwan [ORNL; Sheldon, Frederick T [ORNL; Hively, Lee M [ORNL

2012-01-01

271

Parallel Index and Query for Large Scale Data Analysis  

SciTech Connect

Modern scientific datasets present numerous data management and analysis challenges. State-of-the-art index and query technologies are critical for facilitating interactive exploration of large datasets, but numerous challenges remain in terms of designing a system for process- ing general scientific datasets. The system needs to be able to run on distributed multi-core platforms, efficiently utilize underlying I/O infrastructure, and scale to massive datasets. We present FastQuery, a novel software framework that address these challenges. FastQuery utilizes a state-of-the-art index and query technology (FastBit) and is designed to process mas- sive datasets on modern supercomputing platforms. We apply FastQuery to processing of a massive 50TB dataset generated by a large scale accelerator modeling code. We demonstrate the scalability of the tool to 11,520 cores. Motivated by the scientific need to search for inter- esting particles in this dataset, we use our framework to reduce search time from hours to tens of seconds.

Chou, Jerry; Wu, Kesheng; Ruebel, Oliver; Howison, Mark; Qiang, Ji; Prabhat,; Austin, Brian; Bethel, E. Wes; Ryne, Rob D.; Shoshani, Arie

2011-07-18

272

Large-scale Biomedical Image Analysis in Grid Environments  

PubMed Central

Digital microscopy scanners are capable of capturing multi-Gigapixel images from single slides, thus producing images of sizes up to several tens of Gigabytes each, and a research study may have hundreds of slides from a specimen. The sheer size of the images and the complexity of image processing operations create roadblocks to effective integration of large-scale imaging data in research. This paper presents the application of a component-based Grid middleware system for processing extremely large images obtained from digital microscopy devices. We have developed parallel, out-of-core techniques for different classes of data processing operations commonly employed on images from confocal microscopy scanners. These techniques are combined into data pre-processing and analysis pipelines using the component-based middleware system. The experimental results show that 1) our implementation achieves good performance and can handle very large (terabyte-scale) datasets on high-performance Grid nodes, consisting of computation and/or storage clusters, and 2) it can take advantage of multiple Grid nodes connected over high-bandwidth wide-area networks by combining task- and data-parallelism.

Kumar, Vijay S.; Rutt, Benjamin; Kurc, Tahsin; Catalyurek, Umit; Pan, Tony; Saltz, Joel; Chow, Sunny; Lamont, Stephan; Martone, Maryann

2012-01-01

273

INUNDATION PATTERNS AND FATALITY ANALYSIS ON LARGE-SCALE FLOOD  

NASA Astrophysics Data System (ADS)

In order to enhance the emergency preparedness for large-scale floods of the Ara River, we categorized the inundation patterns and calculated fatality estimates. We devised an effective continuous embankment elevation estimation method employing light detection and ranging data analysis. Drainage pump capabilities, in terms of operatable inundation depth and operatable duration limited by fuel supply logistics, were modeled from pump station data of eac h site along the rivers. Fatality reduction effects due to the enhancement of the drainage capabilities were calculated. We found proper operations of the drainage facilities can decrease the number of estimat ed fatalities considerably in some cases. We also estimated the difference of risk between floods with 200 years return period and those with 1000 years return period. In some of the 1000 years return period cases, we found the estimated fatalities jumped up whereas the populations in inundated areas changed only a little.

Ikeuchi, Koji; Ochi, Shigeo; Yasuda, Goro; Okamura, Jiro; Aono, Masashi

274

Analysis of the topological properties of the proximal femur on a regional scale: evaluation of multi-detector CT-scans for the assessment of biomechanical strength using local Minkowski functionals in 3D  

NASA Astrophysics Data System (ADS)

In our recent studies on the analysis of bone texture in the context of Osteoporosis, we could already demonstrate the great potential of the topological evaluation of bone architecture based on the Minkowski Functionals (MF) in 2D and 3D for the prediction of the mechanical strength of cubic bone specimens depicted by high resolution MRI. Other than before, we now assess the mechanical characteristics of whole hip bone specimens imaged by multi-detector computed tomography. Due to the specific properties of the imaging modality and the bone tissue in the proximal femur, this requires to introduce a new analysis method. The internal architecture of the hip is functionally highly specialized to withstand the complex pattern of external and internal forces associated with human gait. Since the direction, connectivity and distribution of the trabeculae changes considerably within narrow spatial limits it seems most reasonable to evaluate the femoral bone structure on a local scale. The Minkowski functionals are a set of morphological descriptors for the topological characterization of binarized, multi-dimensional, convex objects with respect to shape, structure, and the connectivity of their components. The MF are usually used as global descriptors and may react very sensitively to minor structural variations which presents a major limitation in a number of applications. The objective of this work is to assess the mechanical competence of whole hip bone specimens using parameters based on the MF. We introduce an algorithm that considers the local topological aspects of the bone architecture of the proximal femur allowing to identify regions within the bone that contribute more to the overall mechanical strength than others.

Boehm, H. F.; Link, T. M.; Monetti, R. A.; Kuhn, V.; Eckstein, F.; Raeth, C. W.; Reiser, M.

2006-03-01

275

Multi-scale analysis of a household level agent-based model of landcover change  

Microsoft Academic Search

Scale issues have significant implications for the analysis of social and biophysical processes in complex systems. These same scale implications are likewise considerations for the design and application of models of landcover change. Scale issues have wide-ranging effects from the representativeness of data used to validate models to aggregation errors introduced in the model structure. This paper presents an analysis

Tom P. Evans; Hugh Kelley

2004-01-01

276

Confirmatory Factor Analysis of the Educators' Attitudes toward Educational Research Scale  

ERIC Educational Resources Information Center

This article reports results of a confirmatory factor analysis performed to cross-validate the factor structure of the Educators' Attitudes Toward Educational Research Scale. The original scale had been developed by the author and revised based on the results of an exploratory factor analysis. In the present study, the revised scale was given to…

Ozturk, Mehmet Ali

2011-01-01

277

Age Differences on Alcoholic MMPI Scales: A Discriminant Analysis Approach.  

ERIC Educational Resources Information Center

Administered the Minnesota Multiphasic Personality Inventory to 91 male alcoholics after detoxification. Results indicated that the Psychopathic Deviant and Paranoia scales declined with age, while the Responsibility scale increased with age. (JAC)

Faulstich, Michael E.; And Others

1985-01-01

278

Ordinal Methodology in the Analysis of Likert Scales  

Microsoft Academic Search

Likert scales are widely used in survey studies for attitude measuring. In particular, the questionnaires propagated by the\\u000a SERVQUAL approach are based on Likert scales. Though the problem of attitude suggests an ordinal interpretation of Likert\\u000a scales, attitude survey data are often evaluated with techniques designed for cardinal measurements. The present paper discusses\\u000a the interpretation of scales for attitude measuring

Rainer Göb; Christopher McCollin; Maria Fernanda Ramalhoto

2007-01-01

279

In situ vitrification large-scale operational acceptance test analysis  

SciTech Connect

A thermal treatment process is currently under study to provide possible enhancement of in-place stabilization of transuranic and chemically contaminated soil sites. The process is known as in situ vitrification (ISV). In situ vitrification is a remedial action process that destroys solid and liquid organic contaminants and incorporates radionuclides into a glass-like material that renders contaminants substantially less mobile and less likely to impact the environment. A large-scale operational acceptance test (LSOAT) was recently completed in which more than 180 t of vitrified soil were produced in each of three adjacent settings. The LSOAT demonstrated that the process conforms to the functional design criteria necessary for the large-scale radioactive test (LSRT) to be conducted following verification of the performance capabilities of the process. The energy requirements and vitrified block size, shape, and mass are sufficiently equivalent to those predicted by the ISV mathematical model to confirm its usefulness as a predictive tool. The LSOAT demonstrated an electrode replacement technique, which can be used if an electrode fails, and techniques have been identified to minimize air oxidation, thereby extending electrode life. A statistical analysis was employed during the LSOAT to identify graphite collars and an insulative surface as successful cold cap subsidence techniques. The LSOAT also showed that even under worst-case conditions, the off-gas system exceeds the flow requirements necessary to maintain a negative pressure on the hood covering the area being vitrified. The retention of simulated radionuclides and chemicals in the soil and off-gas system exceeds requirements so that projected emissions are one to two orders of magnitude below the maximum permissible concentrations of contaminants at the stack.

Buelt, J.L.; Carter, J.G.

1986-05-01

280

Sensitivity analysis and scale issues in landslide susceptibility mapping  

NASA Astrophysics Data System (ADS)

Despite the large number of recent advances and developments in landslide susceptibility mapping (LSM) there is still a lack of studies focusing on specific aspects of LSM model sensitivity. For example, the influence of factors of paramount importance such as the survey scale of the landslide conditioning variables (LCVs), the resolution of the mapping unit (MUR) and the optimal number and ranking of LCVs have never been investigated analytically, especially on large datasets. In this paper we attempt this experimentation concentrating on the impact of model tuning choice on the final result, rather than on the comparison of methodologies. To this end, we adopt a simple implementation of the random forest (RF) classification family to produce an ensamble of landslide susceptibility maps for a set of different model settings, input data types and scales. RF classification and regression methods offer a very flexible environment for testing model parameters and mapping hypotheses, allowing for a direct quantification of variable importance. The model choice is, in itself, quite innovative since it is the first time that such technique, widely used in remote sensing for image classification, is used in this form for the production of a LSM. Random forest is a combination of tree (usually binary) bayesian predictors that permits to relate a set of contributing factors with the actual landslides occurrence. Being it a nonparametric model, it is possible to incorporate a range of numeric or categorical data layers and there is no need to select unimodal training data. Many classical and widely acknowledged landslide predisposing factors have been taken into account as mainly related to: the lithology, the land use, the land surface geometry (derived from DTM), the structural and anthropogenic constrains. In addition, for each factor we also included in the parameter set the standard deviation (for numerical variables) or the variety (for categorical ones). The use of random forest enables to estimate the relative importance of the single input parameters and to select the optimal configuration of the regression model. The model was initially applied using the complete set of input parameters, then with progressively smaller subsamples of the parameter space. Considering the best set of parameters we also studied the impact of scale and accuracy of input variables and the influence of the RF model random component on the susceptibility results. We apply the model statistics to a test area in central Italy, the hydrographic basin of the Arno river (ca. 9000 km2), we present the obtained results and discuss them. We also use the outcomes of the parameter sensitivity analysis to investigate the different role of environmental factors in the test area.

Catani, Filippo; Lagomarsino, Daniela; Segoni, Samuele; Tofani, Veronica

2013-04-01

281

The Desirability of Using Confirmatory Factor Analysis on Published Scales  

Microsoft Academic Search

This paper advances an argument in favor of conducting and reporting confirmatory factor analyses (CFA) on existing and previously validated scales and reporting the findings of those analyses in published research. Previous evidence of scale validity does not necessarily ensure validity in subsequent uses. Instead, scale invariance is best viewed as an empirical question. The case is made that CFA

Timothy Levine; Craig R. Hullett; Monique Mitchell Turner; Maria Knight Lapinski

2006-01-01

282

Measuring Mathematics Anxiety: Psychometric Analysis of a Bidimensional Affective Scale  

ERIC Educational Resources Information Center

The purpose of this study is to develop a theoretically and methodologically sound bidimensional affective scale measuring mathematics anxiety with high psychometric quality. The psychometric properties of a 14-item Mathematics Anxiety Scale-Revised (MAS-R) adapted from Betz's (1978) 10-item Mathematics Anxiety Scale were empirically analyzed on a…

Bai, Haiyan; Wang, LihShing; Pan, Wei; Frey, Mary

2009-01-01

283

Revision and Factor Analysis of a Death Anxiety Scale.  

ERIC Educational Resources Information Center

|Earlier research on death anxiety using the 34-item scale developed by Nehrke-Templer-Boyar (NTB) indicated that females and younger persons have significantly higher death anxiety. To simplify a death anxiety scale for use with different age groups, and to determine the conceptual factors actually measured by the scale, a revised 25-item…

Thorson, James A.; Powell, F. C.

284

Measuring Mathematics Anxiety: Psychometric Analysis of a Bidimensional Affective Scale  

ERIC Educational Resources Information Center

|The purpose of this study is to develop a theoretically and methodologically sound bidimensional affective scale measuring mathematics anxiety with high psychometric quality. The psychometric properties of a 14-item Mathematics Anxiety Scale-Revised (MAS-R) adapted from Betz's (1978) 10-item Mathematics Anxiety Scale were empirically analyzed on…

Bai, Haiyan; Wang, LihShing; Pan, Wei; Frey, Mary

2009-01-01

285

Investigating Dimensionality of Eskin's Attitudes Toward Suicide Scale with Mokken Scaling and Confirmatory Factor Analysis  

Microsoft Academic Search

Attitudes toward suicide are often investigated by means of questionnaires, most of which are overly long or of low psychometric quality. Eskin's (2004) Attitudes Towards Suicide Scale is short and first investigations suggest good psychometric properties, but its factor structure has scarcely been explored. Hence, we examined this instrument by a data-analytic approach that combines Mokken scaling and confirmatory factor

Ingo W. Nader; Ulrich S. Tran; Patricia Baranyai; Martin Voracek

2012-01-01

286

Systematical Analysis of the Mechanism of the large-scale construction industry core competitiveness  

Microsoft Academic Search

On the basis of the research of the large-scale construction industry core competitiveness, we have reviewed the competitiveness classic analysis new industry competitiveness frame was made. On this basis, summed up the large-scale construction industrial competitiveness impact factors and measurement indicators systematical, set up a large-scale construction industrial competitiveness formation mechanism model; using structural equation model to Empirical analysis large-scale

Fu-zhou Luo; Jiang-peng Zhang; Lu Bian

2011-01-01

287

Measuring change over time: a comparison of results from a global single item of health status and the multi-dimensional SF36 health status survey questionnaire in patients presenting with menorrhagia  

Microsoft Academic Search

This paper compares the sensitivity to change of a multi-item, multi-dimensional health status measure with a single global health status question, in the assessment of treatment for menorrhagia. A cohort study of patients recruited by general practitioners, was carried out, with a follow up at eighteen months. Questionnaires were administered postally at baseline and follow up. General practices in Berkshire,

C. Jenkinson; V. Peto; A. Coulter

1994-01-01

288

Large-Scale Candidate Gene Analysis of HDL Particle Features  

PubMed Central

Background HDL cholesterol (HDL-C) is an established marker of cardiovascular risk with significant genetic determination. However, HDL particles are not homogenous, and refined HDL phenotyping may improve insight into regulation of HDL metabolism. We therefore assessed HDL particles by NMR spectroscopy and conducted a large-scale candidate gene association analysis. Methodology/Principal Findings We measured plasma HDL-C and determined mean HDL particle size and particle number by NMR spectroscopy in 2024 individuals from 512 British Caucasian families. Genotypes were 49,094 SNPs in >2,100 cardiometabolic candidate genes/loci as represented on the HumanCVD BeadChip version 2. False discovery rates (FDR) were calculated to account for multiple testing. Analyses on classical HDL-C revealed significant associations (FDR<0.05) only for CETP (cholesteryl ester transfer protein; lead SNP rs3764261: p?=?5.6*10?15) and SGCD (sarcoglycan delta; rs6877118: p?=?8.6*10?6). In contrast, analysis with HDL mean particle size yielded additional associations in LIPC (hepatic lipase; rs261332: p?=?6.1*10?9), PLTP (phospholipid transfer protein, rs4810479: p?=?1.7*10?8) and FBLN5 (fibulin-5; rs2246416: p?=?6.2*10?6). The associations of SGCD and Fibulin-5 with HDL particle size could not be replicated in PROCARDIS (n?=?3,078) and/or the Women's Genome Health Study (n?=?23,170). Conclusions We show that refined HDL phenotyping by NMR spectroscopy can detect known genes of HDL metabolism better than analyses on HDL-C.

Kaess, Bernhard M.; Tomaszewski, Maciej; Braund, Peter S.; Stark, Klaus; Rafelt, Suzanne; Fischer, Marcus; Hardwick, Robert; Nelson, Christopher P.; Debiec, Radoslaw; Huber, Fritz; Kremer, Werner; Kalbitzer, Hans Robert; Rose, Lynda M.; Chasman, Daniel I.; Hopewell, Jemma; Clarke, Robert; Burton, Paul R.; Tobin, Martin D.

2011-01-01

289

Psychometric analysis of the Yale-Brown Obsessive–Compulsive Scale Second Edition Symptom Checklist  

Microsoft Academic Search

The Yale-Brown Obsessive–Compulsive Scale (Y-BOCS) was recently revised to address several clinical and conceptual issues. The resultant measure, named the Yale-Brown Obsessive–Compulsive Scale—Second Edition, consists of two primary scales: the Severity Scale and the Symptom Checklist. Although the Severity Scale has been the subject of a comprehensive psychometric analysis, no data have been reported on the psychometric properties of the

Eric A. Storch; Michael J. Larson; Lawrence H. Price; Steven A. Rasmussen; Tanya K. Murphy; Wayne K. Goodman

2010-01-01

290

Numerical Simulation and Scaling Analysis of Cell Printing  

NASA Astrophysics Data System (ADS)

Cell printing, i.e., printing three dimensional (3D) structures of cells held in a tissue matrix, is gaining significant attention in the biomedical community. The key idea is to use inkjet printer or similar devices to print cells into 3D patterns with a resolution comparable to the size of mammalian cells. Achieving such a resolution in vitro can lead to breakthroughs in areas such as organ transplantation. Although the feasibility of cell printing has been demonstrated recently, the printing resolution and cell viability remain to be improved. Here we investigate a unit operation in cell printing, namely, the impact of a cell-laden droplet into a pool of highly viscous liquids. The droplet and cell dynamics are quantified using both direct numerical simulation and scaling analysis. These studies indicate that although cell experienced significant stress during droplet impact, the duration of such stress is very short, which helps explain why many cells can survive the cell printing process. These studies also revealed that cell membrane can be temporarily ruptured during cell printing, which is supported by indirect experimental evidence.

Qiao, Rui; He, Ping

2011-11-01

291

MIXREGLS: A Program for Mixed-Effects Location Scale Analysis  

PubMed Central

MIXREGLS is a program which provides estimates for a mixed-effects location scale model assuming a (conditionally) normally-distributed dependent variable. This model can be used for analysis of data in which subjects may be measured at many observations and interest is in modeling the mean and variance structure. In terms of the variance structure, covariates can by specified to have effects on both the between-subject and within-subject variances. Another use is for clustered data in which subjects are nested within clusters (e.g., clinics, hospitals, schools, etc.) and interest is in modeling the between-cluster and within-cluster variances in terms of covariates. MIXREGLS was written in Fortran and uses maximum likelihood estimation, utilizing both the EM algorithm and a Newton-Raphson solution. Estimation of the random effects is accomplished using empirical Bayes methods. Examples illustrating stand-alone usage and features of MIXREGLS are provided, as well as use via the SAS and R software packages.

Hedeker, Donald; Nordgren, Rachel

2013-01-01

292

MIXREGLS: A Program for Mixed-Effects Location Scale Analysis.  

PubMed

MIXREGLS is a program which provides estimates for a mixed-effects location scale model assuming a (conditionally) normally-distributed dependent variable. This model can be used for analysis of data in which subjects may be measured at many observations and interest is in modeling the mean and variance structure. In terms of the variance structure, covariates can by specified to have effects on both the between-subject and within-subject variances. Another use is for clustered data in which subjects are nested within clusters (e.g., clinics, hospitals, schools, etc.) and interest is in modeling the between-cluster and within-cluster variances in terms of covariates. MIXREGLS was written in Fortran and uses maximum likelihood estimation, utilizing both the EM algorithm and a Newton-Raphson solution. Estimation of the random effects is accomplished using empirical Bayes methods. Examples illustrating stand-alone usage and features of MIXREGLS are provided, as well as use via the SAS and R software packages. PMID:23761062

Hedeker, Donald; Nordgren, Rachel

2013-03-01

293

Genome-scale metabolic models: reconstruction and analysis.  

PubMed

Metabolism can be defined as the complete set of chemical reactions that occur in living organisms in order to maintain life. Enzymes are the main players in this process as they are responsible for catalyzing the chemical reactions. The enzyme-reaction relationships can be used for the reconstruction of a network of reactions, which leads to a metabolic model of metabolism. A genome-scale metabolic network of chemical reactions that take place inside a living organism is primarily reconstructed from the information that is present in its genome and the literature and involves steps such as functional annotation of the genome, identification of the associated reactions and determination of their stoichiometry, assignment of localization, determination of the biomass composition, estimation of energy requirements, and definition of model constraints. This information can be integrated into a stoichiometric model of metabolism that can be used for detailed analysis of the metabolic potential of the organism using constraint-based modeling approaches and hence is valuable in understanding its metabolic capabilities. PMID:21993642

Baart, Gino J E; Martens, Dirk E

2012-01-01

294

Rating scale analysis and psychometric properties of the Caregiver Self-Efficacy Scale for Transfers.  

PubMed

Parents and caregivers faced with the challenges of transferring children with disability are at risk of musculoskeletal injuries and/or emotional stress. The Caregiver Self-Efficacy Scale for Transfers (CSEST) is a 14-item questionnaire that measures self-efficacy for transferring under common conditions. The CSEST yields reliable data and valid inferences; however, its rating scale structure has not been evaluated for utility. The aims of this study were to evaluate the category response structure of the CSEST, test the utility of a revised rating scale structure, and confirm its psychometric properties. The Rasch Measurement Model was used for all analyses. Subjects included 175 adult caregivers recruited from multiple communities. Results confirm that a revised five-category rating scale structure yields reliable data and valid inferences. Given the relationship between self-efficacy and risk of physical and/or emotional stress, measuring parental self-efficacy for transfers is a proactive process in rehabilitation. PMID:22712478

Cipriani, Daniel J; Hensen, Francine E; McPeck, Danielle L; Kubec, Gina L D; Thomas, Julie J

2012-06-19

295

Systematic analysis of scaling properties in deep inelastic scattering  

SciTech Connect

Using the 'quality factor' method, we analyze the scaling properties of deep inelastic processes at the accelerator HERA and fixed target experiments for x{<=}10{sup -2}. We look for scaling formulas of the form {sigma}{sup {gamma}}*{sup p}({tau}), where {tau}(L=logQ{sup 2},Y) is a scaling variable suggested by the asymptotic properties of QCD evolution equations with rapidity Y. We consider four cases: 'fixed coupling', corresponding to the original geometric scaling proposal and motivated by the asymptotic properties of the Balitsky-Kovchegov equation with fixed QCD coupling constant; two versions, 'running coupling I, II,' of the scaling suggested by the Balitsky-Kovchegov equation with running coupling; and 'diffusive scaling' suggested by the QCD evolution equation with Pomeron loops. The quality factors, quantifying the phenomenological validity of the candidate scaling variables, are fitted on the total and deeply virtual Compton scattering cross-section data from HERA and predictions are made for the elastic vector meson and for the diffractive cross sections at fixed small x{sub P} or {beta}. The first three scaling formulas have comparably good quality factors while the fourth one is disfavored. Adjusting initial conditions gives a significant improvement of the running coupling II scaling.

Beuf, Guillaume; Peschanski, Robi; Royon, Christophe; Salek, David [Institut de Physique Theorique, CEA/Saclay, 91191 Gif-sur-Yvette Cedex, France, URA 2306, Unite de Recherche Associee au CNRS (France); IRFU/Service de Physique des Particules, CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France); Institute of Particle and Nuclear Physics, Charles University, Prague (Czech Republic)

2008-10-01

296

Finite Element Analysis of Small Scale Continuous Calving  

NASA Astrophysics Data System (ADS)

Ice shelves are floating ice masses, which are sensitive to climate changes. The main mechanisms for the mass loss of ice shelves around Antarctica are basal melting and calving. For an understanding of the mechanisms of calving the influence of environmental parameters needs to be investigated. We use a fracture mechanical approach to examine the nature and frequency of calving events. Ice responses to load in two ways: on long time scales ice reacts like a viscous fluid, and on short time scale like an elastic solid. As calving is a representation of the solid nature of ice, the elastic response is important and linear elastic fracture mechanics can be applied. However, gravity remains a long time load and hence, a viscous component needs to be taken into account as well. Therefore, we use a Kelvin-Voigt model for analyzing the transient response of an ice shelf to a calving event. In a simplified 2D-model the ice shelf is treated as a rectangular block, in which the gravity force is the only load in a first analysis. The stresses on the surface in the vicinity of the calving front are computed with the finite element software COMSOL. The boundary conditions are the water pressure at the front and bottom of the ice shelf and a constant displacement at the inflow. A stationary state will reappear until eventually the subsequent calving event occurs, the termination time is around 175days. Based on this time interval and the flow velocity of the ice shelf we estimate the calving rate. Different parameter studies reveal the influence of geometry and material parameters on the stresses for an elastic material model. The literature and measurements at the Ekstroem Ice Shelf, East Antarctica, provides the relevant parameter range. Due to the depth-dependent water pressure at the ice front, a bell shaped distribution of stresses on the surface is found. For this reason the location of the maximal stress denotes the most likely position for a calving event and is arranged in between 0.65H and 0.85H, with H the thickness at the ice front. The results of these studies are compared to the results for two cross-sections of measured geometries of the Ekstroem Ice Shelf.

Christmann, Julia; Müller, Ralf; Humbert, Angelika; Gross, Dietmar

2013-04-01

297

Analysis of Hydrogen Depletion Using a Scaled Passive Autocatalytic Recombiner  

SciTech Connect

Hydrogen depletion tests of a scaled passive autocatalytic recombine (pAR) were performed in the Surtsey test vessel at Sandia National Laboratories (SNL). The experiments were used to determine the hydrogen depletion rate of a PAR in the presence of steam and also to evaluate the effect of scale (number of cartridges) on the PAR performance at both low and high hydrogen concentrations.

Blanchat, T.K.; Malliakos, A.

1998-10-28

298

Wavelet analysis of dominant scales of heterogeneous porous media  

Microsoft Academic Search

Heterogeneity of aquifer permeability has a significant influence on the transport of solutes; therefore characterization of aquifer heterogeneity is needed to accurately predict the behavior of solutes. A critical characteristic of heterogeneity is a characteristic length scale that is a measure of the distance over which property values are correlated. We show that the characteristic length scale of a statistically

Xing Qi; Roseanna M. Neupauer

2008-01-01

299

Reliability and Validity Analysis of the Multiple Intelligence Perception Scale  

ERIC Educational Resources Information Center

|This study mainly aims to develop a scale to determine individual intelligence profiles based on self-perceptions. The study group consists of 925 students studying in various departments of the Faculty of Education at Ahi Evran University. A logical and statistical approach was adopted in scale development. Expert opinion was obtained for the…

Yesil, Rustu; Korkmaz, Ozgen

2010-01-01

300

Nanometer to Centimeter Scale Analysis and Modeling of Pore Structures  

NASA Astrophysics Data System (ADS)

The microstructure and evolution of pore space in rocks is a critically important factor controlling fluid flow. The size, distribution and connectivity of these confined geometries dictate how fluids including H2O and CO2, migrate into and through these micro- and nano-environments, wet and react with the solid. (Ultra)small-angle neutron scattering and autocorrelations derived from BSE imaging provide a method of quantifying pore structures in a statistically significant manner from the nanometer to the centimeter scale. Multifractal analysis provides additional constraints. These methods were used to characterize the pore features of a variety of potential CO2 geological storage formations and geothermal systems such as the shallow buried quartz arenites from the St. Peter Sandstone and the deeper Mt. Simon quartz arenite in Ohio as well as the Eau Claire shale and mudrocks from the Cranfield MS CO2 injection test and the normal temperature and high-temperature vapor-dominated parts of the Geysers geothermal system in California. For example, analyses of samples of St. Peter sandstone show total porosity correlates with changes in pores structure including pore size ratios, surface fractal dimensions, and lacunarity. These samples contain significant large-scale porosity, modified by quartz overgrowths, and neutron scattering results show significant sub-micron porosity, which may make up fifty percent or more of the total pore volume. While previous scattering data from sandstones suggest scattering is dominated by surface fractal behavior, our data are both fractal and pseudo-fractal. The scattering curves are composed of steps, modeled as polydispersed assemblages of pores with log-normal distributions. In some samples a surface-fractal overprint is present. There are also significant changes in the mono and multifractal dimensions of the pore structure as the pore fraction decreases. There are strong positive correlations between D(0) and image and total scattering porosities, and strong negative correlations between these and multifractality, which increases as pore fraction decreases and the percent of (U)SANS porosity increases. Individual fractal dimensions at all q values from the BSE images decrease during silcrete formation. These data suggest that microporosity is more prevalent and may play a much more important role than previously thought in fluid/rock interactions in coarse-grained sandstone. Preliminary results from shale and mudrocks indicate there are dramatic differences not only in terms of total micro- to nano-porosity, but also in terms of pore surface fractal (roughness) and mass fractal (pore distributions) dimensions as well as size distributions. Information from imaging and scattering data can also be used to constrain computer-generated, random, three-dimensional porous structures. The results integrate various sources of experimental information and are statistically compatible with the real rock. This allows a more detailed multiscale analysis of structural correlations in the material. Acknowledgements. Research sponsored by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy.

Wesolowski, D. J.; Anovitz, L.; Vlcek, L.; Rother, G.; Cole, D. R.

2011-12-01

301

Time and space scale analysis of the climate entropy budget  

NASA Astrophysics Data System (ADS)

Either in models or in measurements entropy production and fluxes are generally estimated starting from the ratio of temperature and energy fluxes. Given the nonlinearity of the definition of entropy production, this quantities depend on the time and space resolution involved. It is therefore fundamental for observational and theoretical purposes to know how the climate entropy budget is affected by different time-space coarse graining and what are the errors involved when certain time means (e.g. annual) are used in place of others (e.g. daily). Referring to the entropy budget studied in Pascale et al. (2011), we study the effect of combined space and time averaging of the material entropy production (direct and indirect formula), entropy production due to kinetic energy dissipation, hydrological cycle and ocean turbulence. For the time analysis a 50-year run is taken. Time coarse graining shows that material entropy production decreases as the averaging period is increased. Daily cycle and seasonal cycle are the main signals which can be observed. In the indirect formula (based on radiative fields, Goody 2000) an underestimate of 4% and 10% is found associated with neglecting daily and seasonal correlations. The direct formula is less sensitive and shows errors of 2% and 4% respectively and mainly due to response of the hydrological cycle. The material entropy production due to small-scale ocean turbulence shows a sharp decrease (~ 45%) corresponding to the seasonal cycle and associated with the seasonal thermocline variations. We then take into account also a space coarse graining in which energy fluxes and temperature are re-gridded over space grids of coarser resolution. We find that entropy budget terms decreases when the space resolution is decreased as would be expected from general coarse-graining theory. Our results suggest that the model in consideration, although not designed for dealing with entropy production, behaves consistently with the second law of thermodynamics.

Lucarini, V.; Pascale, S.

2012-04-01

302

PROMIS Pediatric Anger Scale: An Item Response Theory Analysis  

PubMed Central

Purpose The Patient Reported Outcomes Measurement Information System (PROMIS) aims to develop patient-reported outcome (PROs) instruments for use in clinical research. The PROMIS pediatrics (ages 8–17) project focuses on the development of PROs across several health domains (physical function, pain, fatigue, emotional distress, social role relationships, and asthma symptoms). The objective of the present study is to report on the psychometric properties of the PROMIS Pediatric Anger Scale. Methods Participants (n=759) were recruited in public school settings, hospital-based outpatient and subspecialty pediatrics clinics. The anger items (k=10) were administered on one test form. A hierarchical confirmatory factor analytic model (CFA) was conducted to evaluate scale dimensionality and local dependence. Item response theory (IRT) analyses were then used to finalize the item scale and short form. Results CFA confirmed that the anger items are representative of a unidimensional scale and items with local dependence were removed resulting in a six-item short form. The IRT-scaled scores from summed scores and each score’s conditional standard error were calculated for the new six-item PROMIS Pediatric Anger Scale. Conclusions This study provides initial calibrations of the anger items and creates the PROMIS Pediatric Anger Scale, version 1.0

Irwin, Debra E.; Stucky, Brian D.; Langer, Michelle M.; Thissen, David; DeWitt, Esi Morgan; Lai, Jin-Shei; Yeatts, Karin B.; Varni, James W.; DeWalt, Darren A.

2011-01-01

303

Estimating Cognitive Profiles Using Profile Analysis via Multidimensional Scaling (PAMS)  

ERIC Educational Resources Information Center

|Two of the most popular methods of profile analysis, cluster analysis and modal profile analysis, have limitations. First, neither technique is adequate when the sample size is large. Second, neither method will necessarily provide profile information in terms of both level and pattern. A new method of profile analysis, called Profile Analysis

Kim, Se-Kang; Frisby, Craig L.; Davison, Mark L.

2004-01-01

304

Scaling properties of the Arctic sea ice Deformation from Buoy Dispersion Analysis  

Microsoft Academic Search

A temporal and spatial scaling analysis of Arctic sea ice deformation is performed over time scales from 3 hours to 3 months and over spatial scales from 300 m to 300 km. The deformation is derived from the dispersion of pairs of drifting buoys, using the IABP (International Arctic Buoy Program) buoy data sets. This study characterizes the deformation of

J. Weiss; P. Rampal; D. Marsan; R. Lindsay; H. Stern

2007-01-01

305

Some Methods to Determine Scaled Mode Shapes in Natural Input Modal Analysis  

Microsoft Academic Search

When the modal model is going to be used for structural modification or for structural response simulation, the scaled mode shapes must be known. If natural input modal analysis is performed, only un-scaled mode shapes can be obtained and an extra method is necessary to obtain the scaling factor. In this paper, two new methods based on mass change are

Manuel López Aenlle; Rune Brincker; Alfonso Fernández Canteli

306

Graph based multi-scale analysis of building system transport models  

Microsoft Academic Search

This paper offers a framework for multi-scale analysis, modeling, and control design for energy efficient building systems models. Our unique approach is to conceptualize the building systems problems as dynamics (convection-diffusion equations) on a building graph. While the original graph - that resolves the smallest of the scales - is complex, we use the coarse spatio-temporal scales associated with any

Prashant G. Mehta; Mihai Dorobantu; Andrzej Banaszuk

2006-01-01

307

Image Analysis Using Quantum Entropy Scale Space and Diffusion Concepts.  

National Technical Information Service (NTIS)

This report documents investigations of the connections between scale space and the linear and nonlinear diffusion of images, as well as investigations of concepts of generalized entropy and quantum entropy and their measures. The generalized entropies in...

M. W. Coffey

2009-01-01

308

Design and analysis of large-scale wireless communications networks  

Microsoft Academic Search

This paper presents fundamental design and performance assessment methodologies for modern large-scale enterprise wireless communications networks comprised of many system components. Large-scale wireless networks are needed to serve mobile users in a region and to satisfy their intra- and inter-region communications requirements by adopting network-on-the-move (NOTM) concepts. For global access, the NOTM systems will connect to wireless and terrestrial networks

Kenneth Y. Jo; Syed R. Ali

2006-01-01

309

Flight Trials and Drag Analysis of a Scale Model Floatplane  

Microsoft Academic Search

This paper reports on the flight trials performed to support the development of the Tigerfish retractable float system. A 1\\/6th scale model of a Cessna 208 has been built, instrumented and flight tested using conventional fixed floats, to estimate the zero-lift drag coefficient of a scale model aircraft with a conventional fixed float system. This drag coefficient is then compared

M. R. Tetlow; A. Smith

2007-01-01

310

Regional scale analysis of denitrification in north temperate forest soils  

Microsoft Academic Search

Large scale analyses of biogeochemical processes are necessary for understanding anthropogenic effects on global climate and\\u000a environmental quality. Regional scale estimates of denitrification from forest soils in southern lower Michigan USA were produced\\u000a by stratifying the region into landscape experimental units using soil texture and natural drainage classes, and extrapolating\\u000a data to larger areas using a geographic information system (GIS).

Peter M. Groffman; James M. Tiedje; Delbert L. Mokma; Stephen Simkins

1992-01-01

311

Design, analysis, and test verification of advanced encapsulation systems. Triannual report for period ending 31 March 1983  

SciTech Connect

Construction of several full size qualification modules using polyurethane encapsulant and a Tedlar front cover is discussed. In addition, an electrical isolation analysis is reported which was to develop a method for evaluating the multi-dimensional effects of the modular conductor geometry on the electric field. The multi-dimensional electric field was calculated with a finite-element-based code using the analogy between thermal and electrostatic fields. (LEW)

Garcia, A. III; Kallis, J.M.; Trucker, D.C.

1983-06-01

312

TMFA: A FORTRAN Program for Three-Mode Factor Analysis and Individual Differences Multidimensional Scaling.  

ERIC Educational Resources Information Center

TMFA, a FORTRAN program for three-mode factor analysis and individual-differences multidimensional scaling, is described. Program features include a variety of input options, extensive preprocessing of input data, and several alternative methods of analysis. (Author)

Redfield, Joel

1978-01-01

313

TMFA: A FORTRAN Program for Three-Mode Factor Analysis and Individual Differences Multidimensional Scaling.  

ERIC Educational Resources Information Center

|TMFA, a FORTRAN program for three-mode factor analysis and individual-differences multidimensional scaling, is described. Program features include a variety of input options, extensive preprocessing of input data, and several alternative methods of analysis. (Author)|

Redfield, Joel

1978-01-01

314

A biomechanical analysis of applied pinch force during periodontal scaling  

PubMed Central

One of the factors associated with the high prevalence of upper extremity musculoskeletal disorders, such as carpal tunnel syndrome, among dental practitioners is the repeated high pinch force applied during periodontal scaling. The goal of this study was to determine the relationship between the pinch force applied during periodontal scaling and the forces generated at the tip of the tool. A linear biomechanical model that incorporated tool reaction forces and a calculated safety margin was created to predict the pinch force applied by experienced and inexperienced dentists during periodontal scaling. Six dentists and six dental students used an instrumented scaling tool while performing periodontal scaling on patients. Thumb pinch force was measured by a pressure sensor, while the forces developed at the instrument tip were measured by a six-axis load cell. A biomechanical model was used to calculate a safety factor and to predict the applied pinch force. For experienced dentists, the model was moderately successful in predicting pinch force (R2 = 0.59). For inexperienced dentists, the model failed to predict peak pinch force (R2 = 0.01). The mean safety margin was higher for inexperienced (4.88±1.58) than experienced (3.35±0.55) dentists, suggesting that students apply excessive force during scaling.

Villanueva, Alfredo; Dong, Hui; Rempel, David

2009-01-01

315

Item response analysis of the Positive and Negative Syndrome Scale  

PubMed Central

Background Statistical models based on item response theory were used to examine (a) the performance of individual Positive and Negative Syndrome Scale (PANSS) items and their options, (b) the effectiveness of various subscales to discriminate among individual differences in symptom severity, and (c) the appropriateness of cutoff scores recently recommended by Andreasen and her colleagues (2005) to establish symptom remission. Methods Option characteristic curves were estimated using a nonparametric item response model to examine the probability of endorsing each of 7 options within each of 30 PANSS items as a function of standardized, overall symptom severity. Our data were baseline PANSS scores from 9205 patients with schizophrenia or schizoaffective disorder who were enrolled between 1995 and 2003 in either a large, naturalistic, observational study or else in 1 of 12 randomized, double-blind, clinical trials comparing olanzapine to other antipsychotic drugs. Results Our analyses show that the majority of items forming the Positive and Negative subscales of the PANSS perform very well. We also identified key areas for improvement or revision in items and options within the General Psychopathology subscale. The Positive and Negative subscale scores are not only more discriminating of individual differences in symptom severity than the General Psychopathology subscale score, but are also more efficient on average than the 30-item total score. Of the 8 items recently recommended to establish symptom remission, 1 performed markedly different from the 7 others and should either be deleted or rescored requiring that patients achieve a lower score of 2 (rather than 3) to signal remission. Conclusion This first item response analysis of the PANSS supports its sound psychometric properties; most PANSS items were either very good or good at assessing overall severity of illness. These analyses did identify some items which might be further improved for measuring individual severity differences or for defining remission thresholds. Findings also suggest that the Positive and Negative subscales are more sensitive to change than the PANSS total score and, thus, may constitute a "mini PANSS" that may be more reliable, require shorter administration and training time, and possibly reduce sample sizes needed for future research.

Santor, Darcy A; Ascher-Svanum, Haya; Lindenmayer, Jean-Pierre; Obenchain, Robert L

2007-01-01

316

Grading Scales of Virginia High Schools and Admissions Action at Virginia Tech: A Research Analysis.  

ERIC Educational Resources Information Center

Descriptive statistics of grading scales used in 371 Virginia high schools are discussed in light of the admissions decisions at Virginia Polytechnic Institute and State University. An analysis of the effect of grading scales on admissions decisions is presented. Nontraditional analysis is recommended as an alternative for interpreting the complex…

Carson, E. W.; And Others

1990-01-01

317

Application of multidimensional scaling to the analysis of sensory evaluations of stimuli with known attribute structures  

Microsoft Academic Search

Examined sensory perceptions of dimensionally simple stimuli composed of 1 or 2 objectively measurable attributes of flavor (sweet, sour) and color (red) using multidimensional scaling analysis. In 3 experiments with 20–30 19–36 yr old Ss each, high correlations were found between the objectively measurable physical characteristics of the stimuli and the perceptual spaces obtained by multidimensional scaling analysis of expressed

James M. McCullough; Charlene S. Martinsen; Reza Moinpour

1978-01-01

318

Direct patterning of free standing three dimensional silicon nanofibrous network to facilitate multi-dimensional growth of fibroblasts and osteoblasts.  

PubMed

The advent of tissue engineering has invigorated interest in novel tissue regeneration matrices. An ideal matrix that simulates the natural extra cellular matrix (ECM) should be nanoscale, with three dimensionally interconnected nanofibers which cannot be generated by current methods such as electrospinning. Furthermore, certain biocompatible materials like silicon cannot be electrospun. We present a novel MHz laser synthesis method that permits sub-100 nm scale structures on any material, including silicon, that mimic the natural ECM. Owing to its three dimensional interlinked nature, the nanofibrous substrate is shown to guide the osteoblasts and fibroblasts to grow not only planarly to the surface, as is true for conventional scaffolds, but also expand and grow upward vertically. This method of synthesis demonstrates promise for novel three dimensional (3D) scaffolds that can assist in tissue and bone regeneration and a myriad of other applications such as drug delivery and biosensing. PMID:24059086

Premnath, Priyatha; Tan, Bo; Venkatakrishnan, Krishnan

2013-11-01

319

A multi-scale analysis of rainfall estimation products over West Africa: from the seasonal to the convective system scale  

NASA Astrophysics Data System (ADS)

The AMMA program contributed to acquire relevant ground observations in the West African monsoon area to validate satellite rainfall estimation products at several temporal and spatial scales. A comparison of rainfall estimates retrieved from several IR/MW combined algorithms with precipitation accumulations derived from rain gauge measurements was performed at the seasonal scale (pre and post onset of the 2006 monsoon) in the Sahelian band, and at daily time scales. A diurnal cycle analysis over three regions of Western Africa to help understanding strengths and weaknesses of rainfall algorithms according to regional rainfall characteristics is presented. Furthermore, a power spectrum study is carried out in those three regions over the whole rainy season for a qualitative comparison of the validation datasets with the three rainfall estimate products. Finally a selected meso-scale convective event is analyzed in details. We used the datasets of three satellite rainfall products: TMPA (0.25°-3 hours), GsMap-MVK (0.1°-1h) and EPSAT-SG (0.1°-15mn). The various scales of this study have required several validation datasets : - gridded rainfall estimates from the CILSS rain gauge network over the Sahelian band at the 1°-10-day scale; a dataset of high resolution (0.01°-1h) gridded precipitation estimates over three regions of Western Africa elaborated from dense gauge networks near Niamey (Niger), Kopargo (Benin) and Dakar (Senegal). Two additional fine scale validation datasets have been used for the case study: the 5-minute krigged rain gauge dataset and the 7-minute rainfall estimates dataset at 1.5 km of altitude retrieved from the Ronsard radar observations during the AMMA experiment. The study reveals significant differences between the satellite and ground rainfall estimates depending on the temporal scales, the period in the rainy season (monsoon's pre/post onset) and regional specificities. In particular, the large spatial variability found in the ground rainfall diurnal cycles indicates how difficult it is to tune an algorithm to give realistic rain estimation on a global scale and be able to reproduce local rainfall characteristics. Finally, this multi-scale analysis helps to develop tools in order to assess the performance of the future Megha-Tropiques rainfall estimation combined product, to define its future characteristics in the context of the GPM constellation and formulate recommendations for its validation plan.

Chambon, P.; Roca, R.; Jobard, I.; Bergès, J. C.

2009-04-01

320

Construct Validation of the Translated Version of the Work-Family Conflict Scale for Use in Korea  

ERIC Educational Resources Information Center

|Recently, the stress of work-family conflict has been a critical workplace issue for Asian countries, especially within those cultures experiencing rapid economic development. Our research purpose is to translate and establish construct validity of a Korean-language version of the Multi-Dimensional Work-Family Conflict (WFC) scale used in the…

Lim, Doo Hun; Morris, Michael Lane; McMillan, Heather S.

2011-01-01

321

Task aversiveness and procrastination: a multi-dimensional approach to task aversiveness across stages of personal projects  

Microsoft Academic Search

The purpose of this research was to explore notions of task aversiveness across stages of personal projects. 95 female and 66 male undergraduate students enrolled in an introductory psychology class completed Personal Projects Analysis (PPA; Little, 1983 [Personal projects: a rationale and method for investigation. Environment and Behaviour, 15, 273–309]). Based on theories of action proposed by Little (1983) and

Allan K. Blunt; Timothy A. Pychyl

2000-01-01

322

Defining the multi-dimensional aspects of household waste management: A study of reported behavior in Devon  

Microsoft Academic Search

This paper examines the structure of waste reduction, reuse and recycling behavior within the context of wider research on environmental action in and around the home. Using a sample of 1265 households from Devon, England, the research examined a range of environmental behaviors, focusing on energy saving, water conservation, green consumerism and waste management. Using factor analysis, the data were

Stewart Barr; Andrew Gilg; Nicholas Ford

2005-01-01

323

Neuron-Glia Interaction as a Possible Glue to Translate the Mind-Brain Gap: A Novel Multi-Dimensional Approach Toward Psychology and Psychiatry  

PubMed Central

Neurons and synapses have long been the dominant focus of neuroscience, thus the pathophysiology of psychiatric disorders has come to be understood within the neuronal doctrine. However, the majority of cells in the brain are not neurons but glial cells including astrocytes, oligodendrocytes, and microglia. Traditionally, neuroscientists regarded glial functions as simply providing physical support and maintenance for neurons. Thus, in this limited role glia had been long ignored. Recently, glial functions have been gradually investigated, and increasing evidence has suggested that glial cells perform important roles in various brain functions. Digging up the glial functions and further understanding of these crucial cells, and the interaction between neurons and glia may shed new light on clarifying many unknown aspects including the mind-brain gap, and conscious-unconscious relationships. We briefly review the current situation of glial research in the field, and propose a novel translational research with a multi-dimensional model, combining various experimental approaches such as animal studies, in vitro & in vivo neuron-glia studies, a variety of human brain imaging investigations, and psychometric assessments.

Kato, Takahiro A.; Watabe, Motoki; Kanba, Shigenobu

2013-01-01

324

Beyond "happy, angry, or sad?": age-of-poser and age-of-rater effects on multi-dimensional emotion perception.  

PubMed

Young, middle-aged, and older raters (N=154) evaluated 1,026 prototypical facial poses of neutrality, happiness, anger, disgust, fear, and sadness stemming from 171 young, middle-aged, and older posers. The majority of poses were rated as multi-faceted, that is, to comprise several expressions of varying intensities. Consistent with the notion of age-related increases in negativity-avoidance/positivity effects, crossed-random effects analyses showed an age-related decrease in the attributions of negative, but not positive and neutral, target expressions (that the poser intended to show), and an age-related increase in the attributions of positive and neutral, but not negative, non-target expressions (that the posers did not intend to show). Expressions were more difficult to read the older the posers, particularly for male posers. These age-of-poser effects were independent of the valence of the expression, but partly differed across age groups of raters. The study supports the idea of multi-dimensionality and age-dependency of emotion perception. PMID:21432636

Riediger, Michaela; Voelkle, Manuel C; Ebner, Natalie C; Lindenberger, Ulman

2011-05-24

325

Wavelet analysis and scaling properties of time series  

Microsoft Academic Search

We propose a wavelet based method for the characterization of the scaling behavior of nonstationary time series. It makes use of the built-in ability of the wavelets for capturing the trends in a data set, in variable window sizes. Discrete wavelets from the Daubechies family are used to illustrate the efficacy of this procedure. After studying binomial multifractal time series

P. Manimaran; Prasanta K. Panigrahi; Jitendra C. Parikh

2005-01-01

326

Psychometric Analysis of Computer Science Help-Seeking Scales  

ERIC Educational Resources Information Center

The purpose of this study was to develop scales to assess instrumental help seeking, executive help seeking, perceived benefits of help seeking, and avoidance of help seeking and to examine their psychometric properties by conducting factor and reliability analyses. As this is the first attempt to examine the latent structures underlying the…

Pajares, Frank; Cheong, Yuk Fai; Oberman, Paul

2004-01-01

327

A Rasch Analysis of the Teachers Music Confidence Scale  

ERIC Educational Resources Information Center

This article presents a new measure of teachers' confidence to conduct musical activities with young children; Teachers Music Confidence Scale (TMCS). The TMCS was developed using a sample of 284 in-service and pre-service early childhood teachers in Hong Kong Special Administrative Region (HKSAR). The TMCS consisted of 10 musical activities.…

Yim, Hoi Yin Bonnie; Abd-El-Fattah, Sabry; Lee, Lai Wan Maria

2007-01-01

328

Analysis plan for 1985 large-scale tests. Technical report  

Microsoft Academic Search

The purpose of this effort is to assist DNA in planning for large-scale (upwards of 5000 tons) detonations of conventional explosives in the 1985 and beyond time frame. Primary research objectives were to investigate potential means to increase blast duration and peak pressures. This report identifies and analyzes several candidate explosives. It examines several charge designs and identifies advantages and

McMullan

1983-01-01

329

Economic scale, energy and sustainability: an international empirical analysis  

Microsoft Academic Search

This paper examines the relationship of economic scale, as reflected in a country's energy throughput, to that of renewable energy flows through the supporting ecosystem. The renewable flow is net primary productivity (NPP) and is calculated by country and grouped by income per capita levels. The use of fossil fuels first rises and then declines relative to available renewable energies

P. H. Templet

1995-01-01

330

Qualitative Differences of Divalent Salts: Multidimensional Scaling and Cluster Analysis  

Microsoft Academic Search

Sensations from salts of iron, calcium, magnesium, and zinc with different anions were studied using a sorting task and multidimensional scaling (MDS). Ten divalent salts were adjusted in concentrations such that the mean intensity ratings were approximately equal. Stimuli were sorted on the basis of similarity to minimize any semantic influence and were examined with and without nasal occlusion to

Juyun Lim; Harry T. Lawless

2005-01-01

331

Longitudinal invariance analysis of the satisfaction with life scale  

Microsoft Academic Search

This research examined longitudinal measurement invariance in the satisfaction with life scale using two studies. The first followed a sample of 236 university students (93 male and 143 female) who completed the SWLS twice over a two-month interval. The second used a sample of 242 adolescent athletes (133 male and 109 female) who completed the SWLS three times over a

Chia-Huei Wu; Lung Hung Chen; Ying-Mei Tsai

2009-01-01

332

Histogram Analysis Using a Scale-Space Approach  

Microsoft Academic Search

A new application of scale-space filtering to the classical problem of estimating the parameters of a normal mixture distribution is described. The technique involves generating a multiscale description of a histogram by convolving it with a series of Gaussians of gradually increasing width (standard deviation), and marking the location and direction of the sign change of zero-crossings in the second

Mark J. Carlotto

1987-01-01

333

Analysis of small scale magnetic perturbations observed by Oersted  

Microsoft Academic Search

A complete year of Oersted data, from April 1999 to March 2000 has been processed to study small scale variations of the magnetic field with periods of a few seconds. We have used a technique of frequent use in internal geophysics to separate in a signal short term variations from a more regular trend, namely calculating the second derivative of

J. L. Le Mouël; E. Blanter; P. Shebalin; J. J. Berthelier; M. Shnirman

2003-01-01

334

Introducing Scale Analysis by Way of a Pendulum  

ERIC Educational Resources Information Center

|Empirical correlations are a practical means of providing approximate answers to problems in physics whose exact solution is otherwise difficult to obtain. The correlations relate quantities that are deemed to be important in the physical situation to which they apply, and can be derived from experimental data by means of dimensional and/or scale

Lira, Ignacio

2007-01-01

335

Thermal analysis of a chip scale package technology  

Microsoft Academic Search

This paper investigates the thermal performance of chip scale packages. Their small size limits the amount of heat removal from the package top directly to the air, thus the large majority of the heat must be conducted into the circuit board on which they are mounted. Simulations reveal ?ja, is a strong function of package size, with I\\/O count and

Ben Chambers; Tien-Yu Tom Lee; William Blood

1998-01-01

336

Steady state and transient thermal analysis of chip scale packages  

Microsoft Academic Search

This paper summarizes a study of chip scale packages (CSPs) to determine their maximum allowable power dissipation within typical system level environments. These results can be used to determine the applicability of utilizing CSPs from the standpoint of die power dissipation. Both steady state and transient thermal performance is covered in this study. The steady state portion used in-house software,

Ben Chambers; Tien-Yu Tom Lee; William Blood

1998-01-01

337

Shielding effectiveness and statistical analysis of cylindrical scale fuselage model  

Microsoft Academic Search

In this paper, the shielding effectiveness of a cylindrical scaled fuselage model is examined. Measurements of the penetrated field, are performed as a function of frequency. The penetrated field is further statistically analyzed and its distribution is investigated. For the purposes of this investigation, different probability models are introduced while their ability is tested to match the measured data distribution.

Anastasios H. Panaretos; Constantine A. Balanis; Craig R. Birtcher

2005-01-01

338

The Asian Values Scale: Development, Factor Analysis, Validation, and Reliability.  

ERIC Educational Resources Information Center

Client adherence to culture-of-origin values plays an important role in the provision of culturally relevant psychological services. Lack of instruments that measure ethnic cultural values has been a shortcoming of past research. Describes development of an Asian Values Scale (AVS) used to measure psychometric measures in four studies. Results…

Kim, Bryan S. K.; Atkinson, Donald R.; Yang, Peggy H.

1999-01-01

339

Towards the Analysis and Design of Large Scale Networked Systems  

Microsoft Academic Search

Large networks of human and machine systems have stag- geringly complex properties. Many of these poorly under- stood and difficult to predict properties emerge from large- scale interaction and may be positive or negative. Not only do we not understand how complex behavior arises from the interactions of the individual (human or machine) nodes of the network, but the properties

Robin Glinton; Paul Scerri; Katia Sycara

340

Mental Models of Text and Film: a multidimensional scaling analysis  

Microsoft Academic Search

Following a brief review of research using multidimensional scaling as a measure of literary perception, it is proposed that the technique provides one possible route to an illumination of Bransford & Johnson's (1973) idea that when people understand a text they create a model within which events described in the text might reasonably occur. Two hypotheses are proposed and tested.

Jack A. Rowell; Peter d. Moss

1986-01-01

341

The Contraceptive Self-Efficacy Scale: Analysis in Four Samples.  

ERIC Educational Resources Information Center

|The relationship of the Contraceptive Self-Efficacy Scale to contraceptive behavior was explored in four female samples: (1) 258 California adolescents, (2) 259 Chicago (Illinois) adolescents, (3) 231 Montreal (Canada) high school students, and (4) 148 college students. Results are discussed in terms of use in research and clinical settings.…

Levinson, Ruth Andrea; Wan, Choi K.; Beamer, LuAnn J.

1998-01-01

342

A Multidimensional Scaling Analysis of Students' Attitudes about Science Careers  

ERIC Educational Resources Information Center

|To encourage students to seek careers in Science, Technology, Engineering and Mathematics (STEM) fields, it is important to gauge students' implicit and explicit attitudes towards scientific professions. We asked high school and college students to rate the similarity of pairs of occupations, and then used multidimensional scaling (MDS) to create…

Masnick, Amy M.; Valenti, S. Stavros; Cox, Brian D.; Osman, Christopher J.

2010-01-01

343

Mobile Sensor Networks Self Localization based on Multidimensional Scaling  

Microsoft Academic Search

In this paper, we define a mobile self-localization (MSL) problem for sparse mobile sensor networks, and propose an algorithm named Mobility Assisted MDS-MAP(P), based on Multi-dimensional Scaling (MDS) for solving the problem. For sparse sensor networks, all the existing localization algo rithms fail to work properly due to the lack of distance or connectivity data to uniquely calculate the geo-locations.

Chang-hua Wu; Weihua Sheng; Ying Zhang

2007-01-01

344

Numerical Strategies towards Peta-Scale Simulations of Nanoelectronics Devices  

Microsoft Academic Search

We address two challenges with the development of next-generation nanotransistors, (i) the capability of modeling realistically extended structures on an atomistic basis and (ii) predictive simulations that are faster and cheaper than experiments. We have developed a multi-dimensional, quantum transport solver, OMEN, towards these goals. To approach the peta-scale, the calculation of the open boundary conditions connecting the simulation domain

Mathieu Luisier; Gerhard Klimeck

2010-01-01

345

Mathematical analysis of the dimensional scaling technique for the Schroedinger equation with power-law potentials  

SciTech Connect

The dimensional scaling (D-scaling) technique is an innovative asymptotic expansion approach to study the multiparticle systems in molecular quantum mechanics. It enables the calculation of ground and excited state energies of quantum systems without having to solve the Schroedinger equation. In this paper, we present a mathematical analysis of the D-scaling technique for the Schroedinger equation with power-law potentials. By casting the D-scaling technique in an appropriate variational setting and studying the corresponding minimization problem, the D-scaling technique is justified rigorously. A new asymptotic dimensional expansion scheme is introduced to compute asymptotic expansions for ground state energies.

Ding Zhonghai [Department of Mathematical Sciences, University of Nevada Las Vegas, Las Vegas, Nevada 89154-4020 (United States); Department of Mathematics and Taida Institute for Mathematical Sciences, National Taiwan University, Taipei, Taiwan (China); Chen, Goong [Department of Mathematics and Institute for Quantum Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Department of Mathematics and Taida Institute for Mathematical Sciences, National Taiwan University, Taipei, Taiwan (China); Lin, Chang-Shou [Department of Mathematics and Taida Institute for Mathematical Sciences, National Taiwan University, Taipei, Taiwan (China)

2010-12-15

346

Gyrokinetic analysis of thermal transport scaling in NSTX and MAST  

NASA Astrophysics Data System (ADS)

It remains unclear how thermal energy confinement will scale when extrapolating from present-day STs to CTF conditions at higher plasma current and toroidal field (lower collisionality). To address this theoretically we present linear gyrokinetic simulations investigating microstability in the outer half-radius of NSTX and MAST discharges that vary Ip and BT. In high collisionality discharges (low Ip & BT) microtearing modes are often predicted to be unstable. These modes are weakened when artificially reducing electron collisionality, consistent with experimental scaling trends at higher Ip & BT. Whether other modes (ITG/TEM, ETG) arise depends on additional parameters such as profile gradients, effective ionic charge, beta, and flux surface shaping. We also discuss the numerical complications in non-linear microtearing mode simulations that include electromagnetic perturbations, collisions and toroidal flow and flow shear. This work is supported by US DOE contract DE-AC02-09CH11466.

Guttenfelder, Walter; Kaye, S. M.; Candy, J.; Bell, R. E.; Leblanc, B. P.; Hammett, G. W.; Mikkelsen, D. R.; Yuh, H.; Field, A. R.; Valovic, M.; Nevins, W. M.; Wang, E.

2010-11-01

347

Large-scale computations in analysis of structures  

SciTech Connect

Computer hardware and numerical analysis algorithms have progressed to a point where many engineering organizations and universities can perform nonlinear analyses on a routine basis. Through much remains to be done in terms of advancement of nonlinear analysis techniques and characterization on nonlinear material constitutive behavior, the technology exists today to perform useful nonlinear analysis for many structural systems. In the current paper, a survey on nonlinear analysis technologies developed and employed for many years on programmatic defense work at the Lawrence Livermore National Laboratory is provided, and ongoing nonlinear numerical simulation projects relevant to the civil engineering field are described.

McCallen, D.B.; Goudreau, G.L.

1993-09-01

348

Wavelet analysis and scaling properties of time series  

Microsoft Academic Search

We propose a wavelet based method for the characterization of the scaling\\u000abehavior of non-stationary time series. It makes use of the built-in ability of\\u000athe wavelets for capturing the trends in a data set, in variable window sizes.\\u000aDiscrete wavelets from the Daubechies family are used to illustrate the\\u000aefficacy of this procedure. After studying binomial multifractal time series

P. Manimaran; Prasanta K. Panigrahi; Jitendra C. Parikh

2005-01-01

349

Numerical analysis of large-scale surface-piercing propellers  

Microsoft Academic Search

Surface-Piercing Propellers (SPPs) are the preferred propulsion system for light to moderately loaded high-speed applications due to the high fuel efficiency. For highly loaded applications, the efficiency of SPPs tends to decrease because of the limited submerged blade area and the presence of large suction side cavities. Moreover, it is a challenge to design large-scale SPPs that can maintain reliable

Yin Lu Young; Brant R. Savander

2011-01-01

350

Further Analysis of the Discriminate Validity of the Parenting Scale  

Microsoft Academic Search

The psychometric properties of the Parenting Scale (PS), a measure employed to identify use of dysfunctional strategies for\\u000a managing child misbehavior, were examined. Parents of 75 children ages 2 to 12 (45 in the clinic-referred and 30 in the community sample group) completed the PS and a measure of child misbehavior. Mean scores were significantly higher for parents in the

Kurt A. Freeman; Wendy DeCourcey

2007-01-01

351

a Selective Analysis of the Scale of Atmospheric Turbulence  

Microsoft Academic Search

A preliminary investigation of the scale problem in atmospheric turbulence has been carried out. An analytic filter of limited resolving power is applied to simultaneous data from four heated-thermocouple anemometers spaced at varying distances either parallel or normal to the mean wind. Sequences of filtered data are thus obtained for three frequency intervals: 1\\/2 to 1\\/4, 1\\/4 to 1\\/8, and

James G. Howcroft; James R. Smith

1956-01-01

352

Analysis of large-scale social and information networks.  

PubMed

The growth of the Web has required us to think about the design of information systems in which large-scale computational and social feedback effects are simultaneously at work. At the same time, the data generated by Web-scale systems--recording the ways in which millions of participants create content, link information, form groups and communicate with one another--have made it possible to evaluate long-standing theories of social interaction, and to formulate new theories based on what we observe. These developments have created a new level of interaction between computing and the social sciences, enriching the perspectives of both of these disciplines. We discuss some of the observations, theories and conclusions that have grown from the study of Web-scale social interaction, focusing on issues including the mechanisms by which people join groups, the ways in which different groups are linked together in social networks and the interplay of positive and negative interactions in these networks. PMID:23419847

Kleinberg, Jon

2013-02-18

353

Wavelet multiscale analysis for Hedge Funds: Scaling and strategies  

NASA Astrophysics Data System (ADS)

The wide acceptance of Hedge Funds by Institutional Investors and Pension Funds has led to an explosive growth in assets under management. These investors are drawn to Hedge Funds due to the seemingly low correlation with traditional investments and the attractive returns. The correlations and market risk (the Beta in the Capital Asset Pricing Model) of Hedge Funds are generally calculated using monthly returns data, which may produce misleading results as Hedge Funds often hold illiquid exchange-traded securities or difficult to price over-the-counter securities. In this paper, the Maximum Overlap Discrete Wavelet Transform (MODWT) is applied to measure the scaling properties of Hedge Fund correlation and market risk with respect to the S&P 500. It is found that the level of correlation and market risk varies greatly according to the strategy studied and the time scale examined. Finally, the effects of scaling properties on the risk profile of a portfolio made up of Hedge Funds is studied using correlation matrices calculated over different time horizons.

Conlon, T.; Crane, M.; Ruskin, H. J.

2008-09-01

354

ThermalScope: multi-scale thermal analysis for nanometer-scale integrated circuits  

Microsoft Academic Search

Thermal analysis has long been essential for designing reli- able, high-performance, cost-effective integrated circuits (ICs). Increasing power densities are making this problem more important. Characterizing the thermal profile of an IC quickly enough to allow feedback on the thermal effects of tentative design changes is a daunting problem, and its complexity is increasing. The move to nanoscale fabrication processes is

Nicholas Allec; Zyad Hassan; Li Shang; Robert P. Dick; Ronggui Yang

2008-01-01

355

ThermalScope: Multi-scale thermal analysis for nanometer-scale integrated circuits  

Microsoft Academic Search

Thermal analysis has long been essential for designing reliable, high-performance, cost-effective integrated circuits (ICs). Increasing power densities are making this problem more important. Characterizing the thermal profile of an IC quickly enough to allow feedback on the thermal effects of tentative design changes is a daunting problem, and its complexity is increasing. The move to nanoscale fabrication processes is increasing

Nicholas Allec; Zyad Hassan; Li Shang; Robert P. Dick; Ronggui Yang

2008-01-01

356

Dimensionality of the Hospital Anxiety and Depression Scale (HADS) in Cardiac Patients: Comparison of Mokken Scale Analysis and Factor Analysis  

ERIC Educational Resources Information Center

|The Hospital Anxiety and Depression Scale (HADS) measures anxiety and depressive symptoms and is widely used in clinical and nonclinical populations. However, there is some debate about the number of dimensions represented by the HADS. In a sample of 534 Dutch cardiac patients, this study examined (a) the dimensionality of the HADS using Mokken…

Emons, Wilco H. M.; Sijtsma, Klaas; Pedersen, Susanne S.

2012-01-01

357

Wavelet analysis and scaling properties of time series.  

PubMed

We propose a wavelet based method for the characterization of the scaling behavior of nonstationary time series. It makes use of the built-in ability of the wavelets for capturing the trends in a data set, in variable window sizes. Discrete wavelets from the Daubechies family are used to illustrate the efficacy of this procedure. After studying binomial multifractal time series with the present and earlier approaches of detrending for comparison, we analyze the time series of averaged spin density in the 2D Ising model at the critical temperature, along with several experimental data sets possessing multifractal behavior. PMID:16383481

Manimaran, P; Panigrahi, Prasanta K; Parikh, Jitendra C

2005-10-18

358

Manufacturing Cost Analysis for YSZ-Based FlexCells at Pilot and Full Scale Production Scales  

SciTech Connect

Significant reductions in cell costs must be achieved in order to realize the full commercial potential of megawatt-scale SOFC power systems. The FlexCell designed by NexTech Materials is a scalable SOFC technology that offers particular advantages over competitive technologies. In this updated topical report, NexTech analyzes its FlexCell design and fabrication process to establish manufacturing costs at both pilot scale (10 MW/year) and full-scale (250 MW/year) production levels and benchmarks this against estimated anode supported cell costs at the 250 MW scale. This analysis will show that even with conservative assumptions for yield, materials usage, and cell power density, a cost of $35 per kilowatt can be achieved at high volume. Through advancements in cell size and membrane thickness, NexTech has identified paths for achieving cell manufacturing costs as low as $27 per kilowatt for its FlexCell technology. Also in this report, NexTech analyzes the impact of raw material costs on cell cost, showing the significant increases that result if target raw material costs cannot be achieved at this volume.

Scott Swartz; Lora Thrun; Robin Kimbrell; Kellie Chenault

2011-05-01

359

A meta-analysis of the validity of the employee attitude inventory theft scales  

Microsoft Academic Search

This article summarizes the criterion-related and construct validity evidence for theEmployee Attitude Inventory (EAI) theft scales. These paper-and-pencil measures were designed to help employers gain information about theft among current employees. It is argued that the validity of the theft scales is dependent on the proportion of dishonest employees in the group being screened. Using meta-analysis techniques, the theft scales

Michael A. McDaniel; John W. Jones

1986-01-01

360

Monte Carlo Criticality Methods and Analysis Capabilities in SCALE  

SciTech Connect

This paper describes the Monte Carlo codes KENO V.a and KENO-VI in SCALE that are primarily used to calculate multiplication factors and flux distributions of fissile systems. Both codes allow explicit geometric representation of the target systems and are used internationally for safety analyses involving fissile materials. KENO V.a has limiting geometric rules such as no intersections and no rotations. These limitations make KENO V.a execute very efficiently and run very fast. On the other hand, KENO-VI allows very complex geometric modeling. Both KENO codes can utilize either continuous-energy or multigroup cross-section data and have been thoroughly verified and validated with ENDF libraries through ENDF/B-VII.0, which has been first distributed with SCALE 6. Development of the Monte Carlo solution technique and solution methodology as applied in both KENO codes is explained in this paper. Available options and proper application of the options and techniques are also discussed. Finally, performance of the codes is demonstrated using published benchmark problems.

Goluoglu, Sedat [ORNL; Petrie Jr, Lester M [ORNL; Dunn, Michael E [ORNL; Hollenbach, Daniel F [ORNL; Rearden, Bradley T [ORNL

2011-01-01

361

X-RIME: Cloud-Based Large Scale Social Network Analysis  

Microsoft Academic Search

As an important technique in modern sociology, social network analysis has gained a lot of attention from many disciplines, and been used as important complements to traditional statistics and data analysis. In order to make it affordable for analysts with massive and fast growing networks, we present X-RIME, a cloud-based library for large scale social network analysis. We propose an

Wei Xue; JuWei Shi; Bo Yang

2010-01-01

362

Survival Analysis for a Large-Scale Forest Health Issue: Missouri Oak Decline  

Microsoft Academic Search

Survival analysis methodologies provide novel approaches for forest mortality analysis that may aid in detecting, monitoring, and mitigating of large-scale forest health issues. This study examined survivor analysis for evaluating a regional forest health issue – Missouri oak decline. With a statewide Missouri forest inventory, log-rank tests of the effects of covariates on the survivor function and equality of the

C. W. Woodall; P. L. Grambsch; W. Thomas; W. K. Moser

2005-01-01

363

Multidimensional scaling modelling approach to latent profile analysis in psychological research  

Microsoft Academic Search

Because profile analysis is widely used in studying types of people, we propose an alternative technique for such analysis in this article. As an application of the multidimensional scaling (MDS) model, MDS profile analysis is proposed as an approach for studying both group and\\/or individual profile patterns. This approach requires one to think of MDS solutions as profiles. The MDS

Cody S. Ding

2006-01-01

364

AdS and stabilized extra dimensions in multi-dimensional gravitational models with nonlinear scalar curvature terms R-1 and R4  

NASA Astrophysics Data System (ADS)

We study multi-dimensional gravitational models with scalar curvature nonlinearities of types R-1 and R4. It is assumed that the corresponding higher dimensional spacetime manifolds undergo a spontaneous compactification to manifolds with a warped product structure. Special attention has been paid to the stability of the extra-dimensional factor spaces. It is shown that for certain parameter regions the systems allow for a freezing stabilization of these spaces. In particular, we find for the R-1 model that configurations with stabilized extra dimensions do not provide a late-time acceleration (they are AdS), whereas the solution branch which allows for accelerated expansion (the dS branch) is incompatible with stabilized factor spaces. In the case of the R4 model, we obtain that the stability region in parameter space depends on the total dimension D = dim(M) of the higher dimensional spacetime M. For D > 8 the stability region consists of a single (absolutely stable) sector which is shielded from a conformal singularity (and an antigravity sector beyond it) by a potential barrier of infinite height and width. This sector is smoothly connected with the stability region of a curvature-linear model. For D < 8 an additional (metastable) sector exists which is separated from the conformal singularity by a potential barrier of finite height and width so that systems in this sector are prone to collapse into the conformal singularity. This second sector is not smoothly connected with the first (absolutely stable) one. Several limiting cases and the possibility of inflation are discussed for the R4 model.

Günther, Uwe; Zhuk, Alexander; Bezerra, Valdir B.; Romero, Carlos

2005-08-01

365

POLARIZED LINE FORMATION IN MULTI-DIMENSIONAL MEDIA. IV. A FOURIER DECOMPOSITION TECHNIQUE TO FORMULATE THE TRANSFER EQUATION WITH ANGLE-DEPENDENT PARTIAL FREQUENCY REDISTRIBUTION  

SciTech Connect

To explain the linear polarization observed in spatially resolved structures in the solar atmosphere, the solution of polarized radiative transfer (RT) equation in multi-dimensional (multi-D) geometries is essential. For strong resonance lines, partial frequency redistribution (PRD) effects also become important. In a series of papers, we have been investigating the nature of Stokes profiles formed in multi-D media including PRD in line scattering. For numerical simplicity, so far we have restricted our attention to the particular case of PRD functions which are averaged over all the incident and scattered directions. In this paper, we formulate the polarized RT equation in multi-D media that takes into account the Hanle effect with angle-dependent PRD functions. We generalize here to the multi-D case the method for Fourier series expansion of angle-dependent PRD functions originally developed for RT in one-dimensional geometry. We show that the Stokes source vector S = (S{sub I} , S{sub Q} , S{sub U} ){sup T} and the Stokes vector I = (I, Q, U){sup T} can be expanded in terms of infinite sets of components S-tilde{sup (k)}, I-tilde{sup (k)}, respectively, k in [0, +{infinity}). We show that the components S-tilde{sup (k)} become independent of the azimuthal angle ({psi}) of the scattered ray, whereas the components I-tilde{sup (k)} remain dependent on {psi} due to the nature of RT in multi-D geometry. We also establish that S-tilde{sup (k)} and I-tilde{sup (k)} satisfy a simple transfer equation, which can be solved by any iterative method such as an approximate Lambda iteration or a Bi-Conjugate Gradient-type projection method provided we truncate the Fourier series to have a finite number of terms.

Anusha, L. S.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, 2nd Block, Bangalore 560 034 (India)

2011-09-20

366

Assessing multiple-group diagnostic problems with multi-dimensional receiver operating characteristic surfaces: application to proton MR Spectroscopy (MRS) in HIV-related neurological injury.  

PubMed

We present the multi-dimensional Receiver Operating Characteristic (ROC) surface, a plot of the true classification rates of tests based on levels of biological markers, for multi-group discrimination, as an extension of the ROC curve, commonly used in two-group diagnostic testing. The volume under this surface (VUS) is a global accuracy measure of a test to classify subjects in multiple groups and useful to detect trends in marker measurements. We used three-dimensional ROC surfaces, and associated VUS, to discriminate between HIV-negative (NEG), HIV-positive neurologically asymptomatic (NAS) subjects and patients with AIDS demential complex (ADC), using brain metabolites measured by proton MRS. These were ratios of markers of inflammation, Choline (Cho) and myoinositol (MI), and brain injury, N-acetyl aspartate (NAA), divided by Creatine (Cr), measured in the basal ganglia and the frontal white matter. Statistically significant trends were observed in the three groups with respect to MI/Cr (VUS=0.43; 95% confidence interval (CI) 0.33-0.53), Cho/Cr (0.36; 0.27-0.45) in the basal ganglia and NAA/Cr in the frontal white matter (FWM) (0.29; 0.20-0.38), suggesting a continuum of injury during the neurologically asymptomatic stage of HIV infection, particularly with respect to brain inflammation. Adjusting for age increased the combined classification accuracy of age and NAA/Cr (p=0.053). Pairwise comparisons suggested that neuronal damage associated with NAA/Cr decreases was mainly observed in individuals with ADC, raising issues of synergism between HIV infection and age and possible acceleration of neurological deterioration in an aging HIV-positive population. The three-dimensional ROC surface and its associated VUS are useful for assessing marker accuracy, detecting data trends and offering insight in disease processes affecting multiple groups. PMID:18191586

Yiannoutsos, Constantin T; Nakas, Christos T; Navia, Bradford A

2007-10-12

367

Assessing multiple-group diagnostic problems with multi-dimensional receiver operating characteristic surfaces: Application to proton MR Spectroscopy (MRS) in HIV-related neurological injury  

PubMed Central

We present the multi-dimensional Receiver Operating Characteristic (ROC) surface, a plot of the true classification rates of tests based on levels of biological markers, for multi-group discrimination, as an extension of the ROC curve, commonly used in two-group diagnostic testing. The volume under this surface (VUS) is a global accuracy measure of a test to classify subjects in multiple groups and useful to detect trends in marker measurements. We used three-dimensional ROC surfaces, and associated VUS, to discriminate between HIV-negative (NEG), HIV-positive neurologically asymptomatic (NAS) subjects and patients with AIDS demential complex (ADC), using brain metabolites measured by proton MRS. These were ratios of markers of inflammation, Choline (Cho) and myoinositol (MI), and brain injury, N-acetyl aspartate (NAA), divided by Creatine (Cr), measured in the basal ganglia and the frontal white matter. Statistically significant trends were observed in the three groups with respect to MI/Cr (VUS=0.43; 95% confidence interval (CI) 0.33-0.53), Cho/Cr (0.36; 0.27-0.45) in the basal ganglia and NAA/Cr in the frontal white matter (FWM) (0.29; 0.20-0.38), suggesting a continuum of injury during the neurologically asymptomatic stage of HIV infection, particularly with respect to brain inflammation. Adjusting for age increased the combined classification accuracy of age and NAA/Cr (p=0.053). Pairwise comparisons suggested that neuronal damage associated with NAA/Cr decreases was mainly observed in individuals with ADC, raising issues of synergism between HIV infection and age and possible acceleration of neurological deterioration in an aging HIV-positive population. The three-dimensional ROC surface and its associated VUS are useful for assessing marker accuracy, detecting data trends and offering insight in disease processes affecting multiple groups.

Yiannoutsos, Constantin T.; Nakas, Christos T.; Navia, Bradford A.

2013-01-01

368

Wavelet based directional analysis of the gravity field: evidence for large-scale undulations  

NASA Astrophysics Data System (ADS)

In the eighties, the analysis of satellite altimetry data lead to the major discovery of gravity lineations in the oceans, with wavelengths between 200 km and 1400 km. While the existence of the 200 km scale undulations is widely accepted, undulations at scales larger than 400 km are still a matter of debate. In our work, we revisit the topic of the large scale geoid undulations over the oceans in the light of the satellite gravity data provided by the GRACE mission, considerably more precise than the altimetry data at wavelengths larger than 400 km. First, we develop a dedicated method of directional Poisson wavelet analysis on the sphere with significance testing, in order to detect and characterize directional structures in geophysical data on the sphere at different spatial scales. This method is particularly well-suited for potential field analysis. We validate it on a series of synthetic tests, and then apply it to analyze the gravity model EGM2008, as well as a bathymetry dataset independent from gravity. Our analysis confirms the existence of gravity undulations at large scale in the oceans, with characteristic scales between 600 and 2000 km. Their direction correlates well with present-day plate motion over the Pacific ocean, where they are particularly clear, and associated with a conjugate direction at 1500 km scale. A major finding is that the 2000 km scale geoid undulations, which has never been so clearly previously observed, dominate. We discuss these results in terms of geodynamic and mantle convection.

Hayn, M.; Panet, I.; Diament, M.; Holschneider, M.; Mandea, M.; Davaille, A.

2012-04-01

369

Robust Mokken Scale Analysis by Means of the Forward Search Algorithm for Outlier Detection  

ERIC Educational Resources Information Center

|Exploratory Mokken scale analysis (MSA) is a popular method for identifying scales from larger sets of items. As with any statistical method, in MSA the presence of outliers in the data may result in biased results and wrong conclusions. The forward search algorithm is a robust diagnostic method for outlier detection, which we adapt here to…

Zijlstra, Wobbe P.; van der Ark, L. Andries; Sijtsma, Klaas

2011-01-01

370

Extension of Large-Scale Modal Analysis Techniques to Historic Masonry Vaults  

Microsoft Academic Search

As a result of the increasing demand for the condition assessment and rehabilitation of historic structures, the application of modal analysis techniques to large-scale masonry buildings is a growing area for the field of experimental mechanics. Although a large body of literature discusses testing on various forms of laboratory specimens, modal testing on a large-scale historic masonry structures has completely

H. Sezer Atamturktur; Linda M. Hanagan; Thomas E. Boothby

371

Variographic analysis of tropical forest cover from multi-scale remotely sensed imagery  

Microsoft Academic Search

Tropical forest mapping is one of the major environmental concerns at global and regional scales in which remote sensing techniques are firmly involved. This study examines the use of the variogram function to analyse forest cover fragmentation at different image scales. Two main aspects are considered here: (1) analysis of the spatial variability structure of the forest cover observed at

Sergio Colombo; Mario Chica-Olmo; Francisco Abarca; Hugh Eva

2004-01-01

372

Software for multi-scale image analysis: The normalized optimized Anisotropic Wavelet Coefficient method  

Microsoft Academic Search

The two-dimensional Anisotropic Wavelet Transform aims to decipher images in which distributions are combined at different scales. Based on the Optimized Anisotropic Wavelet Coefficient method (OAWC), we present two C++ programs which enable multi-scale analysis and discrimination of objects, or groups of objects, depending on their area, shape ratio, orientation, and location. These programs allow the identification of the different

José Darrozes; Philippe Gaillot; Michel De Saint-Blanquat; Jean Luc Bouchez

1997-01-01

373

Validity of the Quality of School Life Scale: A Primary and Second-Order Factor Analysis  

Microsoft Academic Search

A primary and second-order principal components analysis was performed on the Quality of School Life Scale (QSL), a popular measure of elementary school climate. The scale was administered to 141 fourth-, fifth-, and sixth-grade students in an elementary school in the Southwestern United States. The findings of this study, like the information reported in the Administration and Technical Manual for

William L. Johnson; Annabel M. Johnson

1993-01-01

374

Are Exaggerated Health Complaints Continuous or Categorical? A Taxometric Analysis of the Health Problem Overstatement Scale  

Microsoft Academic Search

A taxometric analysis of 3 factor scales extracted from the Health Problem Overstatement (HPO) scale of the Psychological Screening Inventory (PSI; R. I. Lanyon, 1970, 1978) was performed on the data from 1,240 forensic and psychiatric patients. Mean above minus below a cut, maximum covariance, and latent-mode factor analyses produced results indicative of dimensional latent structure for the exaggerated health

Glenn D. Walters; David T. R. Berry; Richard I. Lanyon; Michael P. Murphy

2009-01-01

375

Are Exaggerated Health Complaints Continuous or Categorical? A Taxometric Analysis of the Health Problem Overstatement Scale  

ERIC Educational Resources Information Center

|A taxometric analysis of 3 factor scales extracted from the Health Problem Overstatement (HPO) scale of the Psychological Screening Inventory (PSI; R. I. Lanyon, 1970, 1978) was performed on the data from 1,240 forensic and psychiatric patients. Mean above minus below a cut, maximum covariance, and latent-mode factor analyses produced results…

Walters, Glenn D.; Berry, David T. R.; Lanyon, Richard I.; Murphy, Michael P.

2009-01-01

376

Multi-scale Modeling and Analysis of Nano-RFID Systems on HPC Setup  

Microsoft Academic Search

In this paper we have worked out on some the complex modeling aspects such as Multi Scale modeling, MATLAB Sugar based modeling and have shown the complexities involved in the analysis of Nano RFID (Radio Frequency Identification) systems. We have shown the modeling and simulation and demonstrated some novel ideas and library development for Nano RFID. Multi scale modeling plays

Rohit Pathak; Satyadhar Joshi

2009-01-01

377

Application of PAMS (Profile Analysis via Multidimensional Scaling) Model to Constructing Cognitive Ability Patterns.  

ERIC Educational Resources Information Center

This study described an explicit multidimensional scaling (MDS) model for profile data, the Profile Analysis via Multidimensional Scaling (PAMS) model. It also illustrated the application of this model to the study of the structure of cognitive ability patterns using the Woodcock-Johnson Psychoeducational Battery-Revised (WJPB-R; 1989; 1991) and…

Kim, Se-Kang; Davison, Mark L.

378

Factor Analysis of the Omega Scale: A Scale Designed To Measure the Attitudes of College Students toward Their Own Deaths and the Disposition of Their Bodies.  

ERIC Educational Resources Information Center

|A study was undertaken to provide a factor analysis of the Omega Scale, a 25-item, Likert-type scale developed in 1984 to assess attitudes toward death and funerals and other body disposition practices. The Omega Scale was administered to 250 students enrolled in introductory psychology classes at two higher education institutions in Alabama.…

Staik, Irene M.

379

Large-scale temporal analysis of computer and information science  

NASA Astrophysics Data System (ADS)

The main aim of the project reported in this paper was twofold. One of the primary goals was to produce an extensive source of network data for bibliometric analyses of field dynamics in the case of Computer and Information Science. To this end, we rendered the raw material of the DBLP computer and infoscience bibliography into a comprehensive collection of dynamic network data, promptly available for further statistical analysis. The other goal was to demonstrate the value of our data source via its use in mapping Computer and Information Science (CIS). An analysis of the evolution of CIS was performed in terms of collaboration (co-authorship) network dynamics. Dynamic network analysis covered three quarters of the XX. century (76 years, from 1936 to date). Network evolution was described both at the macro- and the mezo level (in terms of community characteristics). Results show that the development of CIS followed what appears to be a universal pattern of growing into a "mature" discipline.

Soos, Sandor; Kampis, George; Gulyás, László

2013-09-01

380

A confirmatory factor analysis of the Boredom Proneness Scale.  

PubMed

Researchers have extensively investigated the factor structure of the Boredom Proneness Scale (BPS; R. Farmer & N. D. Sundberg, 1986) using exploratory factor analyses (EFAs), with inconsistent methodology and results. Thus, the purpose of the present study was to perform confirmatory factor analyses on the BPS to better determine the nature and extent of its underlying factor structure. Participants were 279 undergraduate students majoring in psychology at a university in the southern United States. None of the tested models derived from earlier studies was a reasonable fit to the present data; therefore, the present authors performed an EFA. Although 2 factors were revealed, these results, coupled with markedly different results from previous factor analytic studies of the BPS, suggest it is unlikely that the present factor structure is replicable. The BPS does not appear to have a replicable factor structure. PMID:19943400

Melton, Amanda M A; Schulenberg, Stefan E

2009-10-01

381

A Large Scale Assessment of the Introductory Courses: Analysis  

NASA Astrophysics Data System (ADS)

We present the first data on four interventions in our large introductory courses. We are performing a large scale assessment of the introductory courses. The four interventions are: 1) the introduction of new research-based laboratories and teaching pedagogies into the laboratory/recitation sections, 2) training the teaching assistants in the new pedagogies and the development and use of grading rubrics, 3) the integration of the lecture and the lab with the new research-based laboratories and pedagogies in place and 4) a completely laboratory-based, interactive engagement course as a small, independent section of the course. We present data on two of the courses in our introductory sequence: the first semester algebra-based and calculus-based courses.

Cheng, Kwan; Pietan, Amy; Thacker, Beth

2010-03-01

382

Large scale gymnastics championships: An on-line interactive collection and analysis of scores  

Microsoft Academic Search

APL has proved to be a magnificent and simple tool for the collection and analysis of the rather complicated scoring in large-scale regional, national or international gymnastics championships, a task previously done by teams of human scorers.

Daniel L. Bernitt; James S. Walton; Frederick S. Bader

1975-01-01

383

Brief Psychometric Analysis of the Self-Efficacy Teacher Report Scale  

ERIC Educational Resources Information Center

|This study provides preliminary analysis of reliability and validity of scores on the Self-Efficacy Teacher Report Scale, which was designed to assess teacher perceptions of self-efficacy of students aged 8 to 17 years. (Contains 3 tables.)|

Erford, Bradley T.; Duncan, Kelly; Savin-Murphy, Janet

2010-01-01

384

Validation of SCALE for High Temperature Gas-Cooled Reactor Analysis.  

National Technical Information Service (NTIS)

This report documents verification and validation studies carried out to assess the performance of the SCALE code system methods and nuclear data for modeling and analysis of High Temperature Gas- Cooled Reactor (HTGR) configurations. Validation data were...

D. Ilas E. E. Sunny G. Ilas R. P. Kelly

2012-01-01

385

Software Process Improvement Motivators: An Analysis using Multidimensional Scaling  

Microsoft Academic Search

In this paper we present an analysis of software practitioners' motivations for software process improvement (SPI). Our findings are based on an empirical study of SPI in 13 software companies where we conducted focus groups with nearly 200 software practitioners. Our aim is to better understand how companies can maximise practitioner support for SPI. This insight should help SPI managers

Nathan Baddoo; Tracy Hall

2002-01-01

386

GECKO: a complete large-scale gene expression analysis platform  

Microsoft Academic Search

Background: Gecko (Gene Expression: Computation and Knowledge Organization) is a complete, high-capacity centralized gene expression analysis system, developed in response to the needs of a distributed user community. Results: Based on a client-server architecture, with a centralized repository of typically many tens of thousands of Affymetrix scans, Gecko includes automatic processing pipelines for uploading data from remote sites, a data

Joachim Theilhaber; Anatoly Ulyanov; Anish Malanthara; Jack Cole; Dapeng Xu; Robert Nahf; Michael Heuer; Christoph Brockel; Steven Bushnell

2004-01-01

387

Anomaly Detection in Multiple Scale for Insider Threat Analysis  

Microsoft Academic Search

We propose a method to quantify malicious insider activity with statistical and graph-based analysis aided with semantic scoring rules. Different types of personal activities or interactions are monitored to form a set of directed weighted graphs. The semantic scoring rules assign higher scores for the events more significant and suspicious. Then we build personal activity profiles in the form of

Hively; Lee M

2012-01-01

388

Large scale air monitoring: lichen vs. air particulate matter analysis  

Microsoft Academic Search

Biological indicator organisms have been widely used for monitoring and banking purposes for many years. Although the complexity of the interactions between organisms and their environment is generally not easily comprehensible, environmental quality assessment using the bioindicator approach offers some convincing advantages compared to direct analysis of soil, water, or air. Measurement of air particulates is restricted to experienced laboratories

M Rossbach; R Jayasekera; G Kniewald; Nguyen Huu Thang

1999-01-01

389

Multi Dimensional Phase Only Filter.  

National Technical Information Service (NTIS)

Today's sensor networks provide a wide variety of application domain for high-speed pattern classification systems. Such high-speed systems can be achieved by the use of optical implementation of specialized POF correlator. In this research we discuss the...

K. S. Gudmunsson A. A. S. Awwal

2004-01-01

390

Large-scale proteomic analysis of membrane proteins  

SciTech Connect

Proteomic analysis of membrane proteins is promising in identification of novel candidates as drug targets and/or disease biomarkers. Despite notable technological developments, obstacles related to extraction and solubilization of membrane proteins are frequently encountered. A critical discussion of the different preparative methods of membrane proteins is offered in relation to downstream proteomic applications, mainly gel-based analyses and mass spectrometry. Unknown proteins are often identified by high-throughput profiling of membrane proteins. In search for novel membrane proteins, analysis of protein sequences using computational tools is performed to predict for the presence of transmembrane domains. Here, we also present these bioinformatic tools with the human proteome as a case study. Along with technological innovations, advancements in the areas of sample preparation and computational prediction of membrane proteins will lead to exciting discoveries.

Ahram, Mamoun; Springer, David L.

2004-10-01

391

The error analysis and correcting of scale tape grating encoder  

NASA Astrophysics Data System (ADS)

High precision pointing and tracking is an important performance indicator of the telescope, and tracking is implemented mainly by the azimuth axis and the altitude axis movement together method for alt-azimuth designed telescopes, and as a control feedback angle encoder must be installed on the azimuth axis, pitch axis. Scale tape grating encoder due to the advantages of non-contact measurement, high precision, simple assembly and adjustment, as a new generation of angle encoders has been widely used in modern telescopes' angle measuring system. However performance of these systems can be limited by the factors of mechanical installation, machining error, random error, and other types of error, which often fail to meet arcsecond or sub-arcsecond angle measurement requirements. This paper analyzes the impacts of the mechanical installation eccentric, the roundness error, shafting sloshing on encoder angle measuring, and develops a 4 reading heads, which have 90 ° phase difference, software subdivision angle measurement program. And we make counterclockwise and clockwise angle measuring experiments on a experimental platform, which has mechanical installation eccentric 10um, roundness error 2um and shafting sloshing 0.6". Two sets of experiments measuring angle error RMS values are 0.387'' and 0.487''. The experiments prove that the program can eliminate the angular measurement error due to the mechanical installation the eccentric, machining roundness error, shafting sloshing, achieve arcsecond angle measuring.

Pan, Nian; Ma, Wenli; Huang, Jinlong

2013-09-01

392

Analysis of ICRE (? <= ?ci) plasma production in large scale tokamaks  

NASA Astrophysics Data System (ADS)

The authors study the possibility of target plasma radiofrequency (RF) production in the ion cyclotron range of frequencies (ICRF) (? <= ?ci) in large scale tokamaks before the startup of an Ohmic discharge. A number of experimental and theoretical studies on dense plasma production in the ICRF in toroidal magnetic devices are reviewed. The criteria for optimal development of the RF discharge stages are analysed, i.e., for RF breakdown of the neutral fill gas in the vicinity of the antenna (non-wave stage, ne << na, where ne and na are the densities of electrons and atoms), and the wave stages of initial ionization (ne < na) and neutral gas burnout (ne approximately na) in the whole volume of the plasma torus. A number of requirements for the design of the antenna system are formulated for all stages of dense plasma ICRF production. A scenario for plasma ICRF production with slot type antennas in the ITER tokamak is proposed. Numerical simulations with a 0-D transport code show that in ITER a target plasma with an electron density of approximately=3*1012 cm-3 can be produced by coupling 3-6 MW of RF power to the plasma at a frequency of approximately=3 MHz. Such a level of RF power is sufficient not only for full ionization of the neutral gas but also for heating the produced plasma to electron temperatures of approximately 80 eV

Lysojvan, A. I.; Moiseenko, V. E.; Shvets, O. M.; Stepanov, K. N.

1992-08-01

393

Detailed scaling analysis of low-force polyelectrolyte elasticity  

NASA Astrophysics Data System (ADS)

Single-molecule force-extension data are typically compared to ideal models of polymer behavior that ignore the effects of self-avoidance. Here, we demonstrate a link between single-molecule data and the scaling pictures of a real polymer. We measure a low-force elasticity regime where the extension L of chemically denatured single-stranded DNA grows as a power law with force f : L˜f? , with ??0.60-0.69 . This compares favorably with the “tensile-blob” model of a self-avoiding polymer, which predicts ?=2/3 . We show that the transition out of the low-force regime is highly salt dependent, and use the tensile-blob model to relate this effect to the salt dependence of the polymer’s Kuhn length and excluded-volume parameter. We find that, contrary to the well-known Odijk-Skolnick-Fixman theory, the Kuhn length of single-stranded DNA is linearly proportional to the Debye length of the solution. Finally, we show that the low-force elasticity becomes linear (?=1) at ?3M salt, and interpret this as a ? point of the polymer. At this point, the force-extension data is best described by the wormlike chain model, from which we estimate the bare (nonelectrostatic) persistence length of the polymer to be ?0.6nm .

McIntosh, D. B.; Ribeck, N.; Saleh, O. A.

2009-10-01

394

Multifractal detrended fluctuation analysis in examining scaling properties of the spatial patterns of soil water storage  

NASA Astrophysics Data System (ADS)

Knowledge about the scaling properties of soil water storage is crucial in transferring locally measured fluctuations to larger scales and vice-versa. Studies based on remotely sensed data have shown that the variability in surface soil water has clear scaling properties (i.e., statistically self similar) over a wider range of spatial scales. However, the scaling property of soil water storage to a certain depth at a field scale is not well understood. The major challenges in scaling analysis for soil water are the presence of localized trends and nonstationarities in the spatial series. The objective of this study was to characterize scaling properties of soil water storage variability through multifractal detrended fluctuation analysis (MFDFA). A field experiment was conducted in a sub-humid climate at Alvena, Saskatchewan, Canada. A north-south transect of 624-m long was established on a rolling landscape. Soil water storage was monitored weekly between 2002 and 2005 at 104 locations along the transect. The spatial scaling property of the surface 0 to 40 cm depth was characterized using the MFDFA technique for six of the soil water content series (all gravimetrically determined) representing soil water storage after snowmelt, rainfall, and evapotranspiration. For the studied transect, scaling properties of soil water storage are different between drier periods and wet periods. It also appears that local controls such as site topography and texture (that dominantly control the pattern during wet states) results in multiscaling property. The nonlocal controls such as evapotranspiration results in the reduction of the degree of multiscaling and improvement in the simple scaling. Therefore, the scaling property of soil water storage is a function of both soil moisture status and the spatial extent considered.

Biswas, A.; Zeleke, T. B.; Si, B. C.

2012-03-01

395

Reflectance spectroscopy in analysis of UO2 scale: derivation of a kinetic model of uranium oxidation.  

PubMed

In this study, we analyzed the development of a compact oxide scale built in course of Uranium surface oxidation. The process was monitored by an in-situ acquisition of the reflectance interference peaks in the NIR-MIR. Dielectric properties of the growing oxide scale were derived in accord to the oscillator model. We used effective media approach to simulate heterogeneous dielectric content in the oxide-metal interface. Following dielectric parameterization, structural properties (e.g., scale thickness) of the proposed multi-scale scheme were calculated. As scale's growth process quantified, a valid kinetic model was proposed. Analysis showed that oxidation dynamics is governed by a multi-parabolic, true diffusion-limited mechanism of activation energy conveniently equaling the known anion diffusion enthalpy of 26 kcal/mol. The applied kinetic model suggested a setup of two consecutive oxide scales, characterized by differing anion diffusion rates. Though mathematical formalism presented a similar to the paralinear, time-dependent solution, here, in contrast to the classic paralinear assumption, both scales consisted of a compact, diffusion limited oxide barriers. As a result, the difference in anion flow across the outer and inner scale barriers assigned the overall, pseudo-linear rate constant-kl, of a negative (in contrast to the paralinear approach) value. Next, Uranium oxidation has been studied in the post-elastic domain. Markedly, upon breakaway of the compact oxide scale, classic paralinear behavior was reestablished for scale thickness of > or = 0.5 microm. PMID:19290344

Chernia, Z

2009-01-26

396

Theoretical analysis of the kinetic performance of laboratory- and full-scale composting systems.  

PubMed

Composting research at laboratory-scale is critical for the development of optimized full-scale plants. Discrepancies between processes at laboratory-scale and full-scale systems have been investigated in terms of heat balances, but a kinetic analysis of this issue is still missing. In this study, the composting rate at laboratory-scale was, on average, between 1.9 and 5.7 times faster than in full-scale systems for a set of published studies using municipal solid waste, food waste or similar materials. Laboratory-scale performance and full-scale systems were limited to 71 and 46%, respectively, of their maximum potential due to poor management of environmental process conditions far from their optimum. The main limiting environmental factor was found to be moisture content, followed by temperature. Besides environmental factors, waste composition and particle size were identified as factors accounting for kinetic differences between laboratory- and full-scale systems. Overall, this study identifies those factors that affect the kinetics of the composting process most and revealed a significant margin for reducing process time in full-scale composting. PMID:22452956

Baptista, Marco; Silveira, Ana; Antunes, Fernando

2012-03-26

397

Evaluating multi-scale precipitation forecasts using high resolution analysis  

NASA Astrophysics Data System (ADS)

The SAL (Structure, Amplitude, Location) method is used for verification of precipitation forecasts at horizontal grid spacings ranging from 2.5 km to 25 km, using a high-resolution 1 km precipitation analysis as a reference. The verification focuses on a summertime period with predominantly convective precipitation. The verification domain contains lowland as well as alpine areas. Evaluation of the individual SAL components shows that with regard to area mean values (A) the benefit of high resolutions models becomes apparent only in high impact weather situations. For the summertime period studied, the subjective impression of better structured precipitation fields (S) in higher resolution models can generally be confirmed. The most significant improvement appears to be associated with explicit simulation of deep convection.

Wittmann, C.; Haiden, T.; Kann, A.

2010-07-01

398

Large-scale biomedical image analysis in grid environments.  

PubMed

This paper presents the application of a component-based Grid middleware system for processing extremely large images obtained from digital microscopy devices. We have developed parallel, out-of-core techniques for different classes of data processing operations employed on images from confocal microscopy scanners. These techniques are combined into a data preprocessing and analysis pipeline using the component-based middleware system. The experimental results show that: 1) our implementation achieves good performance and can handle very large datasets on high-performance Grid nodes, consisting of computation and/or storage clusters and 2) it can take advantage of Grid nodes connected over high-bandwidth wide-area networks by combining task and data parallelism. PMID:18348945

Kumar, Vijay S; Rutt, Benjamin; Kurc, Tahsin; Catalyurek, Umit V; Pan, Tony C; Chow, Sunny; Lamont, Stephan; Martone, Maryann; Saltz, Joel H

2008-03-01

399

Scale invariance analysis of the premature ECG signals  

NASA Astrophysics Data System (ADS)

The multifractal detrended fluctuation analysis and detrending moving average algorithm were introduced in detail and applied to the study of the multifractal characteristics of the normal signals, the atrial premature beat (APB) signals and the premature ventricular contraction (PVC) signals. By analyzing the generalized Hurst exponents, Renyi exponents and multifractal spectrum and comparing the relation of h˜h(q) for original signals and their shuffled time series, the result indicated that the three signals have multifractality and present long-range correlation in a certain range. According to the mean value of ??, we found that the strength of the multifractality is varying. The PVC signals is the strongest, and the Normal signals is the weakest. It is useful for clinical practice of medicine to distinguish APB signals with PVC signals.

Wang, Jun; Cheng, Keqiang

2012-06-01

400

A phytosociological system based on multi-scaled pattern analysis: a first example  

Microsoft Academic Search

The aquatic and riparian vegetation of a small Belgian stream is used as a first example for a phytosociological system based on multi-scaled pattern analysis. Surveying is continuous, the stream being divided into ecologically homogeneous sections. Some sections were sampled meter by meter. A pattern analysis of the whole stream and of some of its reaches was then performed. This

G. Bouxin; E. Boulengé

1983-01-01

401

Analysis of the load density of small-scale general selenographic maps of the moon  

Microsoft Academic Search

Comparative analysis of the load density of small-scale lunar maps is carried out. Crater counts were made over a normalized area. Analysis has shown that there exist only local differences in load density between the Lunar Astronautical Chart (U.S.) and the Soviet map of the equatorial zone of the visible hemisphere of the moon. The load density of the maps

K. B. Shingareva; V. P. Shashkina

1975-01-01

402

Principal Component Analysis for Large Scale Problems with Lots of Missing Values  

Microsoft Academic Search

Principal component analysis (PCA) is a well-known classi- cal data analysis technique. There are a number of algorithms for solving the problem, some scaling better than others to problems with high di- mensionality. They also differ in their ability to handle missing values in the data. We study a case where the data are high-dimensional and a majority of the

Tapani Raiko; Alexander Ilin; Juha Karhunen

2007-01-01

403

Elucidation and Structural Analysis of Conserved Pools for Genome-Scale Metabolic Reconstructions  

Microsoft Academic Search

In this article, we introduce metabolite concentration coupling analysis (MCCA) to study conservation relationships for metabolite concentrations in genome-scale metabolic networks. The analysis allows the global identification of subsets of metabolites whose concentrations are always coupled within common conserved pools. Also, the minimal conserved pool identification (MCPI) procedure is developed for elucidating conserved pools for targeted metabolites without computing the

Evgeni V. Nikolaev; Anthony P. Burgard; Costas D. Maranas

2005-01-01

404

Software and algorithms for sensitivity analysis of large-scale differential algebraic systems  

Microsoft Academic Search

Sensitivity analysis for DAE systems is important in many engineering and scientific applications. The information contained in the sensitivity trajectories is useful for parameter estimation, optimization, model reduction and experimental design. In this paper we present algorithms and software for sensitivity analysis of large-scale DAE systems of index up to two. The new software provides for consistent initialization of the

Shengtai Li; Linda Petzold

2000-01-01

405

Analysis of Hoge Religious Motivation Scale by Means of Combined HAC and PCA Methods  

Microsoft Academic Search

We used a method of combined Hierarchical Agglomerative Clustering (HA C) and Principal Components Analysis (PCA) to validate Hoge Intrinsic Religious Motivation Scale and investigate if this consensus procedure provides an efficient technique for the component extraction. Our results confirm the validity of the procedure and suggest that it may be useful exploratory technique for the data analysis in social

A. Stambuk; N. Stambuk; P. Konjevoda

2007-01-01

406

Diagnosis of Plus Disease in Retinopathy of Prematurity Using Retinal Image multiScale Analysis  

Microsoft Academic Search

PURPOSE. To evaluate a semiautomated image analysis software package, Retinal Image multiScale Analysis (RISA), for the di- agnosis of plus disease in preterm infants with retinopathy of prematurity (ROP). METHODS. Digital images of the posterior pole showing both disc and macula in preterm infants with ROP were analyzed with an enhanced version of RISA. Venules (N 106) and arterioles (N

Rony Gelman; M. Elena Martinez-Perez; Deborah K. Vanderveen; Anne Moskowitz; Anne B. Fulton

2005-01-01

407

Sensitivity analysis of a catchment-scale nitrogen model  

NASA Astrophysics Data System (ADS)

There are now considerable expectations that semi-distributed models are useful tools for supporting catchment water quality management. However, insufficient attention has been given to evaluating the uncertainties inherent to this type of model, especially those associated with the spatial disaggregation of the catchment. The Integrated Nitrogen in Catchments model (INCA) is subjected to an extensive regionalised sensitivity analysis in application to the River Kennet, part of the groundwater-dominated upper Thames catchment, UK The main results are: (1) model output was generally insensitive to land-phase parameters, very sensitive to groundwater parameters, including initial conditions, and significantly sensitive to in-river parameters; (2) INCA was able to produce good fits simultaneously to the available flow, nitrate and ammonium in-river data sets; (3) representing parameters as heterogeneous over the catchment (206 calibrated parameters) rather than homogeneous (24 calibrated parameters) produced a significant improvement in fit to nitrate but no significant improvement to flow and caused a deterioration in ammonium performance; (4) the analysis indicated that calibrating the flow-related parameters first, then calibrating the remaining parameters (as opposed to calibrating all parameters together) was not a sensible strategy in this case; (5) even the parameters to which the model output was most sensitive suffered from high uncertainty due to spatial inconsistencies in the estimated optimum values, parameter equifinality and the sampling error associated with the calibration method; (6) soil and groundwater nutrient and flow data are needed to reduce uncertainty in initial conditions, residence times and nitrogen transformation parameters, and long-term historic data are needed so that key responses to changes in land-use management can be assimilated. The results indicate the general difficulty of reconciling the questions which catchment nutrient models are expected to answer with typically limited data sets and limited knowledge about suitable model structures. The results demonstrate the importance of analysing semi-distributed model uncertainties prior to model application, and illustrate the value and limitations of using Monte Carlo-based methods for doing so.

McIntyre, N.; Jackson, B.; Wade, A. J.; Butterfield, D.; Wheater, H. S.

2005-12-01

408

Wavelet-based directional analysis of the gravity field: evidence for large-scale undulations  

NASA Astrophysics Data System (ADS)

In the eighties, the analysis of satellite altimetry data leads to the major discovery of gravity lineations in the oceans, with wavelengths between 200 and 1400 km. While the existence of the 200 km scale undulations is widely accepted, undulations at scales larger than 400 km are still a matter of debate. In this paper, we revisit the topic of the large-scale geoid undulations over the oceans in the light of the satellite gravity data provided by the GRACE mission, considerably more precise than the altimetry data at wavelengths larger than 400 km. First, we develop a dedicated method of directional Poisson wavelet analysis on the sphere with significance testing, in order to detect and characterize directional structures in geophysical data on the sphere at different spatial scales. This method is particularly well suited for potential field analysis. We validate it on a series of synthetic tests, and then apply it to analyze recent gravity models, as well as a bathymetry data set independent from gravity. Our analysis confirms the existence of gravity undulations at large scale in the oceans, with characteristic scales between 600 and 2000 km. Their direction correlates well with present-day plate motion over the Pacific ocean, where they are particularly clear, and associated with a conjugate direction at 1500 km scale. A major finding is that the 2000 km scale geoid undulations dominate and had never been so clearly observed previously. This is due to the great precision of GRACE data at those wavelengths. Given the large scale of these undulations, they are most likely related to mantle processes. Taking into account observations and models from other geophysical information, as seismological tomography, convection and geochemical models and electrical conductivity in the mantle, we conceive that all these inputs indicate a directional fabric of the mantle flows at depth, reflecting how the history of subduction influences the organization of lower mantle upwellings.

Hayn, M.; Panet, I.; Diament, M.; Holschneider, M.; Mandea, M.; Davaille, A.

2012-06-01

409

Characterization of dissolved organic matter in a coral reef ecosystem subjected to anthropogenic pressures (La Réunion Island, Indian Ocean) using multi-dimensional fluorescence spectroscopy.  

PubMed

La Saline fringing reef is the most important coral reef complex of La Réunion Island (southwestern Indian Ocean; 21°07'S, 55°32'E). This ecosystem is subjected to anthropogenic pressures through river inputs and submarine groundwater discharge (SGD). The goal of this study was to characterize the pool of fluorescent dissolved organic matter (FDOM) in different water bodies of La Saline fringing reef ecosystem using excitation-emission matrix (EEM) spectrofluorometry. From EEMs, we identified the different fluorophores by the peak picking technique and determined two fluorescence indices issued from the literature: the humification index (HIX) and the biological index (BIX). The main known fluorophores were present within the sample set: humic-like A, humic-like C, marine humic-like M, tryptophan-like T1 and T2, and tyrosine-like B1 and B2. In some samples, unknown fluorophores ("U") were also detected. The surface oceanic waters located beyond the reef front displayed a typical oligotrophic marine signature, with a dominance of autochthonous/biological material (presence of peaks: T1>B1>A>T2>M>C; HIX: 0.9±0.4; BIX: 2.3±1.1). In the reef waters, the autochthonous/biological fingerprint also dominated even though the content in humic substances was higher (same relative distribution of peaks; HIX: 1.6±0.6; BIX: 1.0±0.1). Sedimentary and volcanic SGD showed very different patterns with a strong terrestrial source for the former (A>T1>C>B1 and A>C>B1; HIX: 9.8±2.0; BIX: 0.8±0.0) and a weak terrestrial source for the latter (A>B1>U3>B2>C and A>U4>C; HIX: 2.4±0.3; BIX: 0.9±0.0). In the Hermitage River, both humic substances and protein-like material were abundant (T1>A>U5>B1>C>B2; HIX: 2.3; BIX: 1.4). We provide evidences for the presence of anthropogenic DOM in some of these water bodies. Some oceanic samples (presence of peaks U1 and U2) were likely contaminated by oil-derived PAHs from ships navigating around the reef front, whereas the Hermitage River was highly impacted by sewage effluents, numerous in this coastal area of La Réunion Island. We conclude that multi-dimensional fluorescence spectroscopy (EEM) coupled to the determination of HIX and BIX is a good tool for assessing the origin and distribution of DOM in the coral reef ecosystems submitted to anthropogenic impacts. PMID:21388658

Tedetti, Marc; Cuet, Pascale; Guigue, Catherine; Goutx, Madeleine

2011-03-08

410

Comparative Analysis of Wavelet-Based Scale-Invariant Feature Extraction Using Different Wavelet Bases  

NASA Astrophysics Data System (ADS)

In this paper, we present comparative analysis of scale-invariant feature extraction using different wavelet bases. The main advantage of the wavelet transform is the multi-resolution analysis. Furthermore, wavelets enable localigation in both space and frequency domains and high-frequency salient feature detection. Wavelet transforms can use various basis functions. This research aims at comparative analysis of Daubechies, Haar and Gabor wavelets for scale-invariant feature extraction. Experimental results show that Gabor wavelets outperform better than Daubechies, Haar wavelets in the sense of both objective and subjective measures.

Lim, Joohyun; Kim, Youngouk; Paik, Joonki

411

Multidisciplinary analysis for large-scale optical design  

NASA Astrophysics Data System (ADS)

Accurately predicting optical performance for any of the near-term concepts proposed under NASA's Origins missions is a uniquely challenging task, and one that has served to highlight a number of areas of necessary advancement in the field of computer-aided engineering analysis. The strongly coupled nature of these classes of problems combined with unprecedented levels of required optical precision demand a solution approach that is itself fundamentally integrated if accurate, efficient analyses, capable of pointing the way towards improved designs are to be achieved. Recent development efforts have served to lay the foundation for an entirely new finite element-based analytical capability; one that is open, highly extensible, is Matlab-hosted, and which utilizes NASTRAN syntax to describe common-model multidisciplinary analyis tasks. Capabilities currently under development, a few of which will be highlighted here, will soon capture behavioural aspects of coupled nonlinear radiative heat transfer, structures, and optics problems to a level of accuracy and performance not yet achieved for these classes of problems, in an environment that will greatly facilitate future research, development, and technical oversight efforts.

Moore, Greg J.; Chainyk, Mike; Schiermeier, John

2004-10-01

412

Multidimensional Scaling Applied to Histogram-Based DNA Analysis  

PubMed Central

This paper aims to study the relationships between chromosomal DNA sequences of twenty species. We propose a methodology combining DNA-based word frequency histograms, correlation methods, and an MDS technique to visualize structural information underlying chromosomes (CRs) and species. Four statistical measures are tested (Minkowski, Cosine, Pearson product-moment, and Kendall ? rank correlations) to analyze the information content of 421 nuclear CRs from twenty species. The proposed methodology is built on mathematical tools and allows the analysis and visualization of very large amounts of stream data, like DNA sequences, with almost no assumptions other than the predefined DNA “word length.” This methodology is able to produce comprehensible three-dimensional visualizations of CR clustering and related spatial and structural patterns. The results of the four test correlation scenarios show that the high-level information clusterings produced by the MDS tool are qualitatively similar, with small variations due to each correlation method characteristics, and that the clusterings are a consequence of the input data and not method's artifacts.

Costa, Antonio C.; Tenreiro Machado, J. A.; Quelhas, Maria Dulce

2012-01-01

413

Multidimensional scaling applied to histogram-based DNA analysis.  

PubMed

This paper aims to study the relationships between chromosomal DNA sequences of twenty species. We propose a methodology combining DNA-based word frequency histograms, correlation methods, and an MDS technique to visualize structural information underlying chromosomes (CRs) and species. Four statistical measures are tested (Minkowski, Cosine, Pearson product-moment, and Kendall ? rank correlations) to analyze the information content of 421 nuclear CRs from twenty species. The proposed methodology is built on mathematical tools and allows the analysis and visualization of very large amounts of stream data, like DNA sequences, with almost no assumptions other than the predefined DNA "word length." This methodology is able to produce comprehensible three-dimensional visualizations of CR clustering and related spatial and structural patterns. The results of the four test correlation scenarios show that the high-level information clusterings produced by the MDS tool are qualitatively similar, with small variations due to each correlation method characteristics, and that the clusterings are a consequence of the input data and not method's artifacts. PMID:22919286

Costa, António C; Tenreiro Machado, J A; Quelhas, Maria Dulce

2012-07-24

414

Drift scale thermomechanical analysis for thermal loading and retrievability studies  

SciTech Connect

Currently, the repository portion of the Mined Geologic Disposal System for the disposal of spent nuclear fuel and high level radioactive waste is in the advanced conceptual design (ACD) stage. As a part of the Thermal Loading Systems Study and the Retrievability Period Systems Study, a numerical method was used to estimate the stability of emplacement drifts. Drift stability is an important performance issue, particularly for the concept of a waste package (WP) in an open drift. Drift stability is both a preclosure and postclosure issue. Specifically, preclosure worker safety and WP retrievability can be affected by drift stability. Important postclosure drift stability issues are the potential for rockfall which might damage a WP or the potential formation of cracks and upheaval of rock masses which may alter the hydrologic performance of the repository. In the current study, thermomechanical analyses, using the Discontinuous Deformation Analysis (DDA) numerical code, were performed to support the thermal loading study and the retrievability study. The coupled effects between thermal and mechanical behavior induced by the excavation, thermal loading and rapid cooling were analyzed using rock-mass models. Input data for the jointed-rock pattern, in situ stress condition, and the material properties of intact rock and rock joints were adopted from the Yucca Mountain Site Characterization Project.

Tsai, F.C.

1995-12-31

415

Cost and performance analysis of physical security systems  

Microsoft Academic Search

Analysis of cost and performance of physical security systems can be a complex, multi-dimensional problem. There are a number of point tools that address various aspects of cost and performance analysis. Increased interest in cost tradeoffs of physical security alternatives has motivated development of an architecture called Cost and Performance Analysis (CPA), which takes a top-down approach to aligning cost

M. J. Hicks; D. Yates; W. H. Jago; A. W. Phillips

1998-01-01

416

Symbolic flux analysis for genome-scale metabolic networks  

PubMed Central

Background With the advent of genomic technology, the size of metabolic networks that are subject to analysis is growing. A common task when analyzing metabolic networks is to find all possible steady state regimes. There are several technical issues that have to be addressed when analyzing large metabolic networks including accumulation of numerical errors and presentation of the solution to the researcher. One way to resolve those technical issues is to analyze the network using symbolic methods. The aim of this paper is to develop a routine that symbolically finds the steady state solutions of large metabolic networks. Results A symbolic Gauss-Jordan elimination routine was developed for analyzing large metabolic networks. This routine was tested by finding the steady state solutions for a number of curated stoichiometric matrices with the largest having about 4000 reactions. The routine was able to find the solution with a computational time similar to the time used by a numerical singular value decomposition routine. As an advantage of symbolic solution, a set of independent fluxes can be suggested by the researcher leading to the formation of a desired flux basis describing the steady state solution of the network. These independent fluxes can be constrained using experimental data. We demonstrate the application of constraints by calculating a flux distribution for the central metabolic and amino acid biosynthesis pathways of yeast. Conclusions We were able to find symbolic solutions for the steady state flux distribution of large metabolic networks. The ability to choose a flux basis was found to be useful in the constraint process and provides a strong argument for using symbolic Gauss-Jordan elimination in place of singular value decomposition.

2011-01-01

417

Confirmatory Factor Analysis of the Frontal Systems Behavior Scale (FrSBe).  

PubMed

The Frontal Systems Behavior Scale (FrSBe) is a 46-item questionnaire that measures behaviors associated with frontal subcortical deficits (apathy, disinhibition, and executive dysfunction) in adult neurologic populations. Based on findings from a previous exploratory factor analysis on the scale, the current study used confirmatory factor analysis to explore and potentially improve on the measurement model fit of current FrSBe scores. Model fit indices and reliabilities (measured using internal consistency reliability) were compared in the original and in several alternative models. The original scale demonstrated a generally good fitting model, although the best fitting model (referred to as the reduced model) removed eight items from the original measure and modestly improved model fit over the original FrSBe. Strong reliability was found in both versions. Results from the current study provide a critical first step in a potential FrSBe scale revision. PMID:23800608

Carvalho, Janessa O; Ready, Rebecca E; Malloy, Paul; Grace, Janet

2013-06-25

418

Scale-free user-network approach to telephone network traffic analysis  

NASA Astrophysics Data System (ADS)

The effect of the user network on the telephone network traffic is studied in this paper. Unlike classical traffic analysis, where users are assumed to be connected uniformly, our proposed method employs a scale-free network to model the behavior of telephone users. Each user has a fixed set of acquaintances with whom the user may communicate, and the number of acquaintances follows a power-law distribution. We show that compared to conventional analysis based upon a fully connected user network, the network traffic is significantly different when the user network assumes a scale-free property. Specifically, network blocking (call failure) is generally more severe in the case of a scale-free user network. It is also shown that the carried traffic is practically limited by the scale-free property of the user network, rather than by the network capacity.

Xia, Yongxiang; Tse, Chi K.; Tam, Wai M.; Lau, Francis C. M.; Small, Michael

2005-08-01

419

Rasch analysis of the General Self-Efficacy Scale (GSES) in spinal cord injury (SCI).  

PubMed

This study examined the psychometric properties of the General Self-Efficacy Scale by applying Rasch analysis to data from 102 persons with spinal cord injury. Our results suggest that the General Self-Efficacy Scale is a psychometrically robust instrument suitable for application in a spinal cord injury population. The General Self-Efficacy Scale shows an overall fit to the Rasch model (?(2) = 15.5, df = 20, p = .75), high reliability (rp = 0.92), ordered response scale structure, and no item bias by gender, age, education, and lesion levels. However, the analyses indicate a ceiling effect and potential to enhance the differentiation of the General Self-Efficacy Scale across self-efficacy levels. PMID:23463793

Peter, Claudio; Cieza, Alarcos; Geyh, Szilvia

2013-03-01

420

Spatial scaling: Its analysis and effects on animal movements in semiarid landscape mosaics  

SciTech Connect

The research conducted under this agreement focused in general on the effects of envirorunental heterogeneity on movements of animals and materials in semiarid grassland landscapes, on the form of scale-dependency of ecological patterns and processes, and on approaches to extrapolating among spatial scales. The findings are summarized in a series of published and unpublished papers that are included as the main body of this report. We demonstrated the value of experimental model systems'' employing observations and experiments conducted in small-scale microlandscapes to test concepts relating to flows of individuals and materials through complex, heterogeneous mosaics. We used fractal analysis extensively in this research, and showed how fractal measures can produce insights and lead,to questions that do not emerge from more traditional scale-dependent measures. We developed new concepts and theory to deal with scale-dependency in ecological systems and with integrating individual movement patterns into considerations of population and ecosystem dynamics.

Wiens, J.A.

1992-09-01

421

Meta-analysis of the Brief Psychiatric Rating Scale Factor Structure  

ERIC Educational Resources Information Center

|A meta-analysis (N=17,620; k=26) of factor analyses of the Brief Psychiatric Rating Scale (BPRS) was conducted. Analysis of the 12 items from Overall et al.'s (J. E. Overall, L. E. Hollister, & P. Pichot, 1974) 4 subscales found support for his 4 subscales. Analysis of all 18 BPRS items found 4 components similar to those of Overall et al. In a…

Shafer, Alan

2005-01-01

422

Meta-Analysis of the MMPI2 Fake Bad Scale: Utility in Forensic Practice  

Microsoft Academic Search

Some clinical researchers disagree regarding the clinical utility of the MMPI-2 Fake Bad scale (FBS ) within forensic and clinical settings. The present meta-analysis summarizes weighted effect size differences among the FBS and other commonly used validity scales (L, F, K, Fb, Fp, F-K, O-S, Ds2, Dsr2 ) in symptom overreporting and comparison groups. Forty studies that included FBS were

Nathaniel W. Nelson; Jerry J. Sweet; George J. Demakis

2006-01-01

423

Multi-scale thermal analysis of GaAs RF device  

Microsoft Academic Search

A multi-scale modeling approach is proposed and employed to investigate thermal issues in GaAs MMIC. Thermal analysis down to the signal transistor level was made possible with the development of this approach using the finite element technique. The multi-scale modeling results are then verified with an infrared temperature measurement technique (infrared micro-thermal imaging technique). Both modeling and experiment results have

Li Li; Roberto Coccioli; Kevin Nary; Phil Canfield

2005-01-01

424

Finite Element Analysis of a Full Scale Bending Test of Cement Treated Soil Column  

Microsoft Academic Search

This paper presents a numerical simulation of a full scale test of a cement-treated soil column under a cantilever condition in a field. A three-dimensional finite element analysis was performed to verify that a elasto- plastic model proposed by the authors can simulate the bending failure behaviour of the full scale soil-cement column. The elasto-plastic model can describe the tensile

T. Namikawa; J. Koseki; Y. Suzuki

425

The Age Universal IE Scale12 and Orientation Toward Religion: Confirmatory Factor Analysis  

Microsoft Academic Search

Confirmatory factor analysis was used to explore the suggested 2-factor and 3-factor models of the Age Universal I-E Scale-12 among 4,160 respondents. The present findings suggested that the 3-factor model provided a better fit of the data than the 2-factor model did. The findings with this version of the Age Universal I-E Scale were consistent with recent theories that the

John Maltby

2002-01-01

426

Gait Analysis of Gender and Age Using a Large-Scale Multi-view Gait Database  

Microsoft Academic Search

\\u000a This paper describes video-based gait feature analysis for gender and age classification using a large-scale multi-view gait\\u000a database. First, we constructed a large-scale multi-view gait database in terms of the number of subjects (168 people), the\\u000a diversity of gender and age (88 males and 80 females between 4 and 75 years old), and the number of observed views (25 views)

Yasushi Makihara; Hidetoshi Mannami; Yasushi Yagi

2010-01-01

427

Practical guidelines to select and scale earthquake records for nonlinear response history analysis of structures  

USGS Publications Warehouse

Earthquake engineering practice is increasingly using nonlinear response history analysis (RHA) to demonstrate performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. Presented herein is a modal-pushover-based scaling (MPS) method to scale ground motions for use in nonlinear RHA of buildings and bridges. In the MPS method, the ground motions are scaled to match (to a specified tolerance) a target value of the inelastic deformation of the first-'mode' inelastic single-degree-of-freedom (SDF) system whose properties are determined by first-'mode' pushover analysis. Appropriate for first-?mode? dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-'mode' SDF system in selecting a subset of the scaled ground motions. Based on results presented for two bridges, covering single- and multi-span 'ordinary standard' bridge types, and six buildings, covering low-, mid-, and tall building types in California, the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

Kalkan, Erol; Chopra, Anil K.

2010-01-01

428

[Recognition of landscape characteristic scale based on two-dimension wavelet analysis].  

PubMed

Three wavelet bases, i. e., Haar, Daubechies, and Symlet, were chosen to analyze the validity of two-dimension wavelet analysis in recognizing the characteristic scales of the urban, peri-urban, and rural landscapes of Shenyang. Owing to the transform scale of two-dimension wavelet must be the integer power of 2, some characteristic scales cannot be accurately recognized. Therefore, the pixel resolution of images was resampled to 3, 3.5, 4, and 4.5 m to densify the scale in analysis. It was shown that two-dimension wavelet analysis worked effectively in checking characteristic scale. Haar, Daubechies, and Symle were the optimal wavelet bases to the peri-urban landscape, urban landscape, and rural landscape, respectively. Both Haar basis and Symlet basis played good roles in recognizing the fine characteristic scale of rural landscape and in detecting the boundary of peri-urban landscape. Daubechies basis and Symlet basis could be also used to detect the boundary of urban landscape and rural landscape, respectively. PMID:20873630

Gao, Yan-Ni; Chen, Wei; He, Xing-Yuan; Li, Xiao-Yu

2010-06-01

429

Characteristic length scales of spatial models in ecology via fluctuation analysis  

PubMed Central

A technique of fluctuation analysis is introduced for the identification of characteristic length scales in spatial models, with similarities to the recently introduced methods using correlations. The identified length scale provides the optimal size to extract non-trivial large-scale behaviour in such models. The method is demonstrated for three biological models: genetic selection, plant competition and a complex marine system; the first two are coupled map lattices and the last one is a cellular automaton. These cover the three possibilities for asymptotic (long time) dynamics: fixation (the system converges to a fixed point); statistical fixation (the spatial statistics converge to fixed values); and complex statistical structure (the statistics do not converge to fixed values). The technique is shown to have an additional use in the identification of aggregation or dispersal at various scales. The method is rigorously justifiable in the cases when the system under analysis satisfies the FKG (Fortuin-Kasteleyn-Ginibre) property and has a fast decay of correlations. We also discuss the connection between the fluctuation analysis length scale and hydrodynamic limits methods to derive large scale equations for ecological models.

Keeling, M. J.; Mezic, I.; Hendry, R. J.; McGlade, J.; Rand, D. A.

1997-01-01

430

[Progress in automatic reconstruction and analysis tools of genome-scale metabolic network].  

PubMed

High-throughput data supply a basis for the reconstruction of genome-scale metabolic networks, and meanwhile bring challenges to the reconstruction and analysis methods. With the increasing of data quantity, the time-consuming manual reconstruction and analysis are far behind the improvement of models. Therefore, various automatic methods emerge. The automatic reconstruction and analysis have irreplaceable effect in the standardization and programming of reconstruction and analysis methods, as well as largely improving the speed of reconstruction and understanding of the metabolic network. In this review, we introduced the progress of automatic reconstruction and the main analysis tools of genome-scale metabolic network. We further summarized the workflow of automatic reconstruction. The difficulties and perspectives on this research field are also discussed. PMID:23016303

Hao, Tong; Ma, Hongwu; Zhao, Xueming

2012-06-01

431

CIAO: Chandra Interactive Analysis of Observations  

NASA Astrophysics Data System (ADS)

Presentations and demonstrations of parts of CIAO, include the new GUIs developed for "FirstLook" analysis, data filtering and browsing; SHERPA, the multi-dimensional, multi-missions modelling and fitting application; CHIPS, the Chandra Imaging and Plotting System; generic data manipulation tools and other applications.

Fruscione, Antonella; Siemiginowska, Aneta; Noble, Michael

1999-01-01

432

Scaling Analysis of Natural Fracture Systems in Support of Fluid Flow Modeling and Seismic Risk Assessment  

NASA Astrophysics Data System (ADS)

Many significant problems in rock engineering require consideration of fluid flow through natural fractures in rock or the mechanical response of a fractured rock mass. Accurate prediction of flow volumes, rates and mass transport through natural fracture systems, and their mechanical response, is critical for design and licensing of nuclear waste repositories, optimization of recovery from many petroleum reservoirs, and also in solution mining, groundwater resource development and protection, and hardrock civil engineering projects. Many of these projects require a large-scale, 3D numerical model for flow, transport or mechanical simulation or visualization. A fundamental problem in constructing these models is that fracture data from wells, boreholes, geophysical profiles or surface outcrops represents a small portion of the rock volume under consideration. Not only does the data represent a very small proportion of the reservoir or rock mass, it also represents fracturing in very restricted size scales. Thus scaling analysis is critical to accurately constructing a fracture model from the data. This paper describes, through two case examples, how scaling analysis techniques have been used to develop models of natural fracturing to support the design and licensing of a high level nuclear waste repository in Finland, and for optimization of a tertiary recovery project in an aging oil field in the US. A new technique for scaling fracture sizes is presented. Together, these two examples illustrate the importance of the scaling analyses, pitfalls in carrying out the analyses, and new methods to improve the 3D characterization of naturally fractured rock masses.

La Pointe, P. R.

2001-12-01

433

Post-hoc Rasch analysis of optimal categorization of an ordered-response scale.  

PubMed

The purpose of this study was to determine the optimal categorization of a self-efficacy ordered-response scale using the Rasch analysis and compare the performance of the Rasch statistics and parameter estimates with conventional statistics. A 50-item scale to measure psychomotor self-efficacy was administered to a total of 2,022 children, including 1,009 boys and 1,013 girls. The data analysis started by collapsing the original five adjacent categories into two, three, and four categories, and a total of 14 data sets were derived. Each of these data sets, including the original one, was analyzed using the Rasch rating scale model, and a set of Rasch model-data fit, category, and separation statistics and parameter estimates, as well as three conventional statistics, were computed and compared. It was found that, instead of the five-category construct designed, the best order of category meanings of the scale in respondents' perceptions was a three-category construct. The Rasch threshold estimates were sensitive indexes in determining the order of the categorization, and that item separation statistics were useful in determining the optimal categorization after its order was confirmed. The commonly used coefficient alpha was found not helpful at all in determining the optimal categorization. The Rasch analysis was demonstrated to be a useful post-hoc analytic approach in determining the optimal categorization of an ordered-response scale. PMID:9661725

Zhu, W; Updyke, W F; Lewandowski, C

1997-01-01

434

Analysis of Large Scale Spatial Variability of Soil Moisture Using a Geostatistical Method  

PubMed Central

Spatial and temporal soil moisture dynamics are critically needed to improve the parameterization for hydrological and meteorological modeling processes. This study evaluates the statistical spatial structure of large-scale observed and simulated estimates of soil moisture under pre- and post-precipitation event conditions. This large scale variability is a crucial in calibration and validation of large-scale satellite based data assimilation systems. Spatial analysis using geostatistical approaches was used to validate modeled soil moisture by the Agriculture Meteorological (AGRMET) model using in situ measurements of soil moisture from a state-wide environmental monitoring network (Oklahoma Mesonet). The results show that AGRMET data produces larger spatial decorrelation compared to in situ based soil moisture data. The precipitation storms drive the soil moisture spatial structures at large scale, found smaller decorrelation length after precipitation. This study also evaluates the geostatistical approach for mitigation for quality control issues within in situ soil moisture network to estimates at soil moisture at unsampled stations.

Lakhankar, Tarendra; Jones, Andrew S.; Combs, Cynthia L.; Sengupta, Manajit; Vonder Haar, Thomas H.; Khanbilvardi, Reza

2010-01-01

435

Wavelet-based multifractal analysis of field scale variability in soil water retention  

NASA Astrophysics Data System (ADS)

Better understanding of spatial variability of soil hydraulic parameters and their relationships to other soil properties is essential to scale-up measured hydraulic parameters and to improve the predictive capacity of pedotransfer functions. The objective of this study was to characterize scaling properties and the persistency of water retention parameters and soil physical properties. Soil texture, bulk density, organic carbon content, and the parameters of the van Genuchten water retention function were determined on 128 soil cores from a 384-m transect with a sandy loam soil, located at Smeaton, SK, Canada. The wavelet transform modulus maxima, or WTMM, technique was used in the multifractal analysis. Results indicate that the fitted water retention parameters had higher small-scale variability and lower persistency than the measured soil physical properties. Of the three distinct scaling ranges identified, the middle region (8-128 m) had a multifractal-type scaling. The generalized Hurst exponent indicated that the measured soil properties were more persistent than the fitted soil hydraulic parameters. The relationships observed here imply that soil physical properties are better predictors of water retention values at larger spatial scales than at smaller scales.

Zeleke, Takele B.; Si, Bing C.

2007-07-01

436

Rasch analysis of the hospital anxiety and depression scale (hads) for use in motor neurone disease  

PubMed Central

Background The Hospital Anxiety and Depression Scale (HADS) is commonly used to assess symptoms of anxiety and depression in motor neurone disease (MND). The measure has never been specifically validated for use within this population, despite questions raised about the scale's validity. This study seeks to analyse the construct validity of the HADS in MND by fitting its data to the Rasch model. Methods The scale was administered to 298 patients with MND. Scale assessment included model fit, differential item functioning (DIF), unidimensionality, local dependency and category threshold analysis. Results Rasch analyses were carried out on the HADS total score as well as depression and anxiety subscales (HADS-T, D and A respectively). After removing one item from both of the seven item scales, it was possible to produce modified HADS-A and HADS-D scales which fit the Rasch model. An 11-item higher-order HADS-T total scale was found to fit the Rasch model following the removal of one further item. Conclusion Our results suggest that a modified HADS-A and HADS-D are unidimensional, free of DIF and have good fit to the Rasch model in this population. As such they are suitable for use in MND clinics or research. The use of the modified HADS-T as a higher-order measure of psychological distress was supported by our data. Revised cut-off points are given for the modified HADS-A and HADS-D subscales.

2011-01-01

437

SPEAR II The Security Protocol Engineering and Analysis Resource  

Microsoft Academic Search

Multi-dimensional security protocol engineering is effective in creating cryptographic protocols since it encompasses a variety of analysis techniques, thereby providing a higher security confidence than individual approaches. SPEAR, the Secu- rity Protocol Engineering and Analysis Resource, was a protocol engineering tool which focused on cryptographic protocols, with the specific aims of enabling secure and efficient protocol designs and support for

Elton Saul; Andrew Hutchison

1999-01-01

438

CRITICAL INFRASTRUCTURE ANALYSIS: A METHODOLOGY FOR INTEGRATED MODELING AND SIMULATION  

Microsoft Academic Search

Integral to efiective critical infrastructure analysis is the assessment of infrastructure vulnerabilities, which seeks to provide insights into po- tential disruptions, insights that may increase the e-cacy of protection plans as well as operations for response and recovery. Efiective criti- cal infrastructures analysis, however, must account for both the multi- dimensional, highly complex characteristics within each infrastructure as well as

William J. Tolone; Seok-Won Lee; Wei-Ning Xiang; Joshua Blackwell; Cody Yeager; Andrew Schumpert; E. Wray Johnson

439

Analysis of Transient Measurements in the ZED-2 Reactor.  

National Technical Information Service (NTIS)

An analysis has been performed of transient measurements carried out recently on simulated CANDU reactor cores in the ZED-2 reactor. The main purpose of the analysis was to compare the results from a multi-dimensional kinetics code, CERKIN, with the measu...

A. P. Baudouin F. N. McDonnell

1977-01-01

440

Analysis of complex vessel experiments using the Hybrid Lagrangian-Eulerian containment code ALICE-II  

SciTech Connect

This paper describes the ALICE-II analysis of and comparison with complex vessel experiments. Tests SM-2 through SM-5 were performed by SRI International in 1978 in studying the structural response of 1/20 scale models of the Clinch River Breeder Reactor to a simulated hypothetical core-disruptive accident. These experiments provided quality data for validating treatments of the nonlinear fluid-structure interactions and many complex excursion phenomena, such as flow through perforated structures, large material distortions, multi-dimensional sliding interfaces, flow around sharp corners, and highly contorted fluid boundaries. Correlations of the predicted pressures with the test results of all gauges are made. Wave characteristics and arrival times are also compared. Results show that the ALICE-II code predicts the pressure profile well. Despite the complexity, the code gave good results for the SM-5 test.

Wang, C.Y.; Ku, J.L.; Zeuch, W.R.

1984-03-01

441

The Genomic HyperBrowser: an analysis web server for genome-scale data.  

PubMed

The immense increase in availability of genomic scale datasets, such as those provided by the ENCODE and Roadmap Epigenomics projects, presents unprecedented opportunities for individual researchers to pose novel falsifiable biological questions. With this opportunity, however, researchers are faced with the challenge of how to best analyze and interpret their genome-scale datasets. A powerful way of representing genome-scale data is as feature-specific coordinates relative to reference genome assemblies, i.e. as genomic tracks. The Genomic HyperBrowser (http://hyperbrowser.uio.no) is an open-ended web server for the analysis of genomic track data. Through the provision of several highly customizable components for processing and statistical analysis of genomic tracks, the HyperBrowser opens for a range of genomic investigations, related to, e.g., gene regulation, disease association or epigenetic modifications of the genome. PMID:23632163

Sandve, Geir K; Gundersen, Sveinung; Johansen, Morten; Glad, Ingrid K; Gunathasan, Krishanthi; Holden, Lars; Holden, Marit; Liestøl, Knut; Nygård, Ståle; Nygaard, Vegard; Paulsen, Jonas; Rydbeck, Halfdan; Trengereid, Kai; Clancy, Trevor; Drabløs, Finn; Ferkingstad, Egil; Kalas, Matús; Lien, Tonje; Rye, Morten B; Frigessi, Arnoldo; Hovig, Eivind

2013-04-30

442

The Genomic HyperBrowser: an analysis web server for genome-scale data  

PubMed Central

The immense increase in availability of genomic scale datasets, such as those provided by the ENCODE and Roadmap Epigenomics projects, presents unprecedented opportunities for individual researchers to pose novel falsifiable biological questions. With this opportunity, however, researchers are faced with the challenge of how to best analyze and interpret their genome-scale datasets. A powerful way of representing genome-scale data is as feature-specific coordinates relative to reference genome assemblies, i.e. as genomic tracks. The Genomic HyperBrowser (http://hyperbrowser.uio.no) is an open-ended web server for the analysis of genomic track data. Through the provision of several highly customizable components for processing and statistical analysis of genomic tracks, the HyperBrowser opens for a range of genomic investigations, related to, e.g., gene regulation, disease association or epigenetic modifications of the genome.

Sandve, Geir K.; Gundersen, Sveinung; Johansen, Morten; Glad, Ingrid K.; Gunathasan, Krishanthi; Holden, Lars; Holden, Marit; Liest?l, Knut; Nygard, Stale; Nygaard, Vegard; Paulsen, Jonas; Rydbeck, Halfdan; Trengereid, Kai; Clancy, Trevor; Drabl?s, Finn; Ferkingstad, Egil; Kalas, Matus; Lien, Tonje; Rye, Morten B.; Frigessi, Arnoldo; Hovig, Eivind

2013-01-01

443

Large-scale analysis of the yeast proteome by multidimensional protein identification technology  

Microsoft Academic Search

We describe a largely unbiased method for rapid and large-scale proteome analysis by multidimensional liquid chromatography, tandem mass spectrometry, and database searching by the SEQUEST algorithm, named multidimensional protein identification technology (MudPIT). MudPIT was applied to the proteome of the Saccharomyces cerevisiae strain BJ5460 grown to mid-log phase and yielded the largest proteome analysis to date. A total of 1,484

Michael P. Washburn; Dirk Wolters; John R. Yates III

2001-01-01

444