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1

Jargonial-Obfuscation(J-O) DISambiguation Elimination via Siegel-Baez Cognition Category-Semantics(C-S) in Siegel FUZZYICS=CATEGORYICS (Son of TRIZ)/(F=C) Tabular List-Format Dichotomy Truth-Table Matrix Analytics  

NASA Astrophysics Data System (ADS)

NOT "philosophy" per se but raising serious salient Arnol'd [Huygens and Barrow, Newton and Hooke(96)] questions begged is Rota empiricism Husserl VS. Frege maths-objects Dichotomy controversy: Hill-Haddock[Husserl or Frege?(00)]as manifestly-demonstrated by Hintikka[B.U.]-Critchey[Derrida Deconstruction Ethics(78)] deconstruction; Altshuler TRIZ; Siegel F=C/C-S; Siegel-Baez(UCR) Cognition C-S = "Category-theory "+" Cognitive-Semantics[Wierzbica-Langacker-Lakoff-Nunez[Where Maths Comes From(00)]-Fauconnier-Turner[Blending(98)]-Coulson[Semantic-Leaps (00)

Siegel, Carl Ludwig; Carl-Ludwig Siegel, Edward

2011-03-01

2

Semantic Search in Tabular Structures  

Microsoft Academic Search

The Semantic Web search aims to overcome the bottleneck of flnding relevant infor- mation using formal knowledge models, e.g. ontologies. The focus of this paper is to extend a typical search engine with semantic search over tabular structures. We cate- gorize HTML documents into topics and genres. Using the TARTAR system, tabular structures in the documents are then automatically transformed

Aleksander Pivk; Matjaz Gams; Mitja Lustrek

2006-01-01

3

Processing genome scale tabular data with wormtable  

PubMed Central

Background Modern biological science generates a vast amount of data, the analysis of which presents a major challenge to researchers. Data are commonly represented in tables stored as plain text files and require line-by-line parsing for analysis, which is time consuming and error prone. Furthermore, there is no simple means of indexing these files so that rows containing particular values can be quickly found. Results We introduce a new data format and software library called wormtable, which provides efficient access to tabular data in Python. Wormtable stores data in a compact binary format, provides random access to rows, and enables sophisticated indexing on columns within these tables. Files written in existing formats can be easily converted to wormtable format, and we provide conversion utilities for the VCF and GTF formats. Conclusions Wormtable’s simple API allows users to process large tables orders of magnitude more quickly than is possible when parsing text. Furthermore, the indexing facilities provide efficient access to subsets of the data along with providing useful methods of summarising columns. Since third-party libraries or custom code are no longer needed to parse complex plain text formats, analysis code can also be substantially simpler as well as being uniform across different data formats. These benefits of reduced code complexity and greatly increased performance allow users much greater freedom to explore their data. PMID:24308302

2013-01-01

4

A new model for tabular-type uranium deposits  

USGS Publications Warehouse

Tabular-type uranium deposits occur as tabular, originally subhorizontal bodies entirely within reduced fluvial sandstones of Late Silurian age or younger. This paper proposes that belts of tabular-type uranium deposits formed in areas of mixed local and regional groundwater discharge shortly after deposition of the host sediments. The general characteristics of tabular-type uranium deposits indicate that their essential feature was the formation at a density-stratified ground-water interface in areas of local and regional ground-water discharge. Reconstruction of the paleohydrogeology is the key to understanding the formation of these deposits. Geologic ground-water controls that favor discharge, such as the pinch-out of major aquifers, are also favorable for uranium ore. The combination of topographic and geologic features that both cause discharge is most favorable for ore deposition. -from Author

Sanford, R. F.

1992-01-01

5

Consistent thermodynamic derivative estimates for tabular equations of state  

Microsoft Academic Search

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce

Gary A. Dilts

2006-01-01

6

Revisiting Bertin Matrices: New Interactions for Crafting Tabular Visualizations  

E-print Network

Revisiting Bertin Matrices: New Interactions for Crafting Tabular Visualizations Charles Perin" by encoding cell values visually and grouping similar rows and columns. Although there were several attempts and accessible to any scientist and researcher [42]. It was based on two simple ideas: i) encoding table

Paris-Sud XI, Université de

7

Consistent thermodynamic derivative estimates for tabular equations of state  

Microsoft Academic Search

A valid fluid equation of state must satisfy the thermodynamic differential conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Typical software interfaces to tabular equations of state based on polynomial or rational interpolants compute derivatives of pressure and energy and may enforce the stability conditions, but do not enforce the consistency condition and its

Gary Dilts

2005-01-01

8

Design of tabular excavations in foliated rock: an integrated numerical  

E-print Network

Design of tabular excavations in foliated rock: an integrated numerical modelling approach E techniques to investigate ground response in the near-field rock mass surrounding the mining excavations Introduction Ore recovery from underground mining involves developing excavations to gain access

9

MCNP/X TRANSPORT IN THE TABULAR REGIME  

SciTech Connect

The authors review the transport capabilities of the MCNP and MCNPX Monte Carlo codes in the energy regimes in which tabular transport data are available. Giving special attention to neutron tables, they emphasize the measures taken to improve the treatment of a variety of difficult aspects of the transport problem, including unresolved resonances, thermal issues, and the availability of suitable cross sections sets. They also briefly touch on the current situation in regard to photon, electron, and proton transport tables.

HUGHES, H. GRADY [Los Alamos National Laboratory

2007-01-08

10

Consistent thermodynamic derivative estimates for tabular equations of state  

E-print Network

Numerical simulations of compressible fluid flows require an equation of state (EOS) to relate the thermodynamic variables of density, internal energy, temperature, and pressure. A valid EOS must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). When phase transitions are significant, the EOS is complicated and can only be specified in a table. For tabular EOS's such as SESAME from Los Alamos National Laboratory, the consistency and stability conditions take the form of a differential equation relating the derivatives of pressure and energy as functions of temperature and density, along with positivity constraints. Typical software interfaces to such tables based on polynomial or rational interpolants compute derivatives of pressure and energy and may enforce the stability conditions, but do not enforce the consistency condition and its derivatives. We describe a new type of table interface based on a constrained local least squar...

Dilts, G A

2005-01-01

11

Summer Decay Processes in a Large Tabular Iceberg  

NASA Astrophysics Data System (ADS)

Summer Decay Processes in a Large Tabular Iceberg Peter Wadhams (1), Till J W Wagner(1) and Richard Bates(2) (1) Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK (2) Scottish Oceans Institute, School of Geography and Geosciences, University of St Andrews, St. Andrews, Scotland KY16 9AL We present observational results from an experiment carried out during July-August 2012 on a giant grounded tabular iceberg off Baffin Island. The iceberg studied was part of the Petermann Ice Island B1 (PIIB1) which calved off the Petermann Glacier in NW Greenland in 2010. Since 2011 it has been aground in 100 m of water on the Baffin Island shelf at 69 deg 06'N, 66 deg 06'W. As part of the project a set of high resolution GPS sensors and tiltmeters was placed on the ice island to record rigid body motion as well as flexural responses to wind, waves, current and tidal forces, while a Waverider buoy monitored incident waves and swell. On July 31, 2012 a major breakup event was recorded, with a piece of 25,000 sq m surface area calving off the iceberg. At the time of breakup, GPS sensors were collecting data both on the main berg as well as on the newly calved piece, while two of us (PW and TJWW) were standing on the broken-out portion which rose by 0.6 m to achieve a new isostatic equilibrium. Crucially, there was no significant swell at the time of breakup, which suggests a melt-driven decay process rather than wave-driven flexural break-up. The GPS sensors recorded two disturbances during the hour preceding the breakup, indicative of crack growth and propagation. Qualitative observation during the two weeks in which our research ship was moored to, or was close to, the ice island edge indicates that an important mechanism for summer ablation is successive collapses of the overburden from above an unsupported wave cut, which creates a submerged ram fringing the berg. A model of buoyancy stresses induced by such rams indicates that they may have the capability through their moment arm of breaking off moderate-sized bergs, which may be the mechanism through which our smaller berg calved.

Wadhams, P.; Wagner, T. M.; Bates, R.

2012-12-01

12

The origin and significance of large, tabular dunite bodies in the Trinity peridotite, northern California  

Microsoft Academic Search

Kilometer-sized, tabular dunite bodies are contained within harzburgite, lherzolite and plagioclase lherzolite host rocks in the Trinity peridotite, northern California. An igneous origin for the dunite by crystal fractionation of olivine from a melt is suggested by their tabular shapes, clots of poikilitic clinopyroxene grains, chromite pods, and by analogy to dunite bodies in the Samail and Vourinos ophiolites (Hopson

James E. Quick

1982-01-01

13

ICESat profiles of tabular iceberg margins and iceberg breakup at low Ted Scambos,1  

E-print Network

ICESat profiles of tabular iceberg margins and iceberg breakup at low latitudes Ted Scambos,1 Olga of tabular iceberg margins and the Ronne Ice Shelf edge reveal shapes indicative of two types of bending forces. Icebergs and shelf fronts in sea-ice-covered areas have broad ($1000 m wide), rounded, $0.6 m

Boyce, C. Kevin

14

Calving of large tabular icebergs from ice shelf rift systems Ian Joughin1,2  

E-print Network

Calving of large tabular icebergs from ice shelf rift systems Ian Joughin1,2 and Douglas R. Mac large icebergs to calve from the Ross Ice Shelf, Antarctica. Time series of rift geometries indicate geometry. Both the observations and model suggest that rift opening, and, thus, tabular-iceberg calving

Boyce, C. Kevin

15

Consistent thermodynamic derivative estimates for tabular equations of state  

NASA Astrophysics Data System (ADS)

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce the consistency condition and its derivatives. The consistency condition is important for the computation of various dimensionless parameters of an EOS that may involve derivatives of up to second order which are important for the development of more sensitive artificial viscosities and Riemann solvers that accurately model shock structure in regions near phase transitions. We describe a table interface based on the tuned regression method, which is derived from a constrained local least-squares regression technique. It is applied to several SESAME EOS showing how the consistency and stability conditions can be satisfied to round-off while computing first and second derivatives with demonstrated second-order convergence. An improvement of 14 orders of magnitude over conventional derivatives is demonstrated, although the method is apparently two orders of magnitude slower, due to the fact that every evaluation requires solving an 11-dimensional nonlinear system. Application is made to the computation of the fundamental derivative.

Dilts, Gary A.

2006-06-01

16

Consistent thermodynamic derivative estimates for tabular equations of state.  

NASA Astrophysics Data System (ADS)

A valid fluid equation of state must satisfy the thermodynamic differential conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Typical software interfaces to tabular equations of state based on polynomial or rational interpolants compute derivatives of pressure and energy and may enforce the stability conditions, but do not enforce the consistency condition and its derivatives, which is important for the computation of dimensionless quantities associated with more sensitive artificial viscosities and Riemann solvers that accurately model shock structure in regions near phase transitions. We describe a new type of table interface derived from a constrained local least squares regression technique. Application to several SESAME tables shows the consistency condition can be satisfied to round-off with third-order accuracy. An improvement of 14 orders of magnitude over conventional derivatives is demonstrated, although the new method is two orders of magnitude slower, due to solving an 11-dimensional nonlinear system. The new approach can be used to construct consistent and stable tables of derivatives, however.

Dilts, Gary

2005-07-01

17

Consistent thermodynamic derivative estimates for tabular equations of state.  

PubMed

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce the consistency condition and its derivatives. The consistency condition is important for the computation of various dimensionless parameters of an EOS that may involve derivatives of up to second order which are important for the development of more sensitive artificial viscosities and Riemann solvers that accurately model shock structure in regions near phase transitions. We describe a table interface based on the tuned regression method, which is derived from a constrained local least-squares regression technique. It is applied to several SESAME EOS showing how the consistency and stability conditions can be satisfied to round-off while computing first and second derivatives with demonstrated second-order convergence. An improvement of 14 orders of magnitude over conventional derivatives is demonstrated, although the method is apparently two orders of magnitude slower, due to the fact that every evaluation requires solving an 11-dimensional nonlinear system. Application is made to the computation of the fundamental derivative. PMID:16907020

Dilts, Gary A

2006-06-01

18

Deriving tabular event-based specifications from goal-oriented requirements models  

Microsoft Academic Search

Goal-oriented methods are increasingly popular for elaborating software requirements. They offer systematic support for incrementally building intentional, structural and operational models of the software and its environment. They also provide various techniques for early analysis, notably, to manage conflicting goals or to anticipate abnormal environment behaviours that prevent goals from being achieved. On the other hand, tabular event-based methods are

Renaud De Landtsheer; Emmanuel Letier

2004-01-01

19

Composite MARC Format. A Tabular Listing of Content Designators Used in the MARC Formats.  

ERIC Educational Resources Information Center

Intended to be used for comparative purposes and in the design of generalized computer programs for systems using the MARC formats for bibliographic records, this publication contains a listing in tabular form of the content designators used in the various MARC formats. Content designators are listed under Leader, Control Fields, and Variable…

Library of Congress, Washington, DC. MARC Development Office.

20

Ontology patterns for tabular representations of biomedical knowledge on neglected tropical diseases  

PubMed Central

Motivation: Ontology-like domain knowledge is frequently published in a tabular format embedded in scientific publications. We explore the re-use of such tabular content in the process of building NTDO, an ontology of neglected tropical diseases (NTDs), where the representation of the interdependencies between hosts, pathogens and vectors plays a crucial role. Results: As a proof of concept we analyzed a tabular compilation of knowledge about pathogens, vectors and geographic locations involved in the transmission of NTDs. After a thorough ontological analysis of the domain of interest, we formulated a comprehensive design pattern, rooted in the biomedical domain upper level ontology BioTop. This pattern was implemented in a VBA script which takes cell contents of an Excel spreadsheet and transforms them into OWL-DL. After minor manual post-processing, the correctness and completeness of the ontology was tested using pre-formulated competence questions as description logics (DL) queries. The expected results could be reproduced by the ontology. The proposed approach is recommended for optimizing the acquisition of ontological domain knowledge from tabular representations. Availability and implementation: Domain examples, source code and ontology are freely available on the web at http://www.cin.ufpe.br/~ntdo. Contact: fss3@cin.ufpe.br PMID:21685092

Santana, Filipe; Schober, Daniel; Medeiros, Zulma; Freitas, Fred; Schulz, Stefan

2011-01-01

21

Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer  

E-print Network

Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer K.M. Stuart Ã?, D Resolution enhancement Icebergs Sea ice NSF Antarctic cruise a b s t r a c t Knowledge of iceberg locations icebergs scatter microwave energy more than sea ice and sea water, icebergs are detected as high

Long, David G.

22

Using visual cues for extraction of tabular data from arbitrary HTML documents  

Microsoft Academic Search

We describe a method to extract tabular data from web pages. Rather than just analyzing the DOM tree, we also exploit visual cues in the rendered version of the document to extract data from tables which are not explicitly marked with an HTML table element. To detect tables, we rely on a variant of the well-known X-Y cut algorithm as

Bernhard Krüpl; Marcus Herzog; Wolfgang Gatterbauer

2005-01-01

23

Algorithms for Hyperspectral Signature Classification in Non-resolved Object Characterization Using Tabular Nearest Neighbor Encoding  

NASA Astrophysics Data System (ADS)

Accurate spectral signature classification is key to the nonimaging detection and recognition of spaceborne objects. In classical hyperspectral recognition applications, signature classification accuracy depends on accurate spectral endmember determination [1]. However, in selected target recognition (ATR) applications, it is possible to circumvent the endmember detection problem by employing a Bayesian classifier. Previous approaches to Bayesian classification of spectral signatures have been rule- based, or predicated on a priori parameterized information obtained from offline training, as in the case of neural networks [1,2]. Unfortunately, class separation and classifier refinement results in these methods tends to be suboptimal, and the number of signatures that can be accurately classified often depends linearly on the number of inputs. This can lead to potentially significant classification errors in the presence of noise or densely interleaved signatures. In this paper, we present an emerging technology for nonimaging spectral signature classfication based on a highly accurate but computationally efficient search engine called Tabular Nearest Neighbor Encoding (TNE) [3]. Based on prior results, TNE can optimize its classifier performance to track input nonergodicities, as well as yield measures of confidence or caution for evaluation of classification results. Unlike neural networks, TNE does not have a hidden intermediate data structure (e.g., the neural net weight matrix). Instead, TNE generates and exploits a user-accessible data structure called the agreement map (AM), which can be manipulated by Boolean logic operations to effect accurate classifier refinement algorithms. This allows the TNE programmer or user to determine parameters for classification accuracy, and to mathematically analyze the signatures for which TNE did not obtain classification matches. This dual approach to analysis (i.e., correct vs. incorrect classification) has been shown to significantly strengthen analysis of classifier performance in support of classifier optimization. We show that AM-based classification can be modified to include dynamic tracking of input statistical changes, to achieve accurate signature classification in the presence of noise, closely spaced or interleaved signatures, and simulated optical distortions. In particular, we examine two critical cases: (1) classification of multiple closely spaced signatures that are difficult to separate using distance measures, and (2) classification of materials in simulated hyperspectral images of spaceborne satellites. In each case, test data are derived from a NASA database of space material signatures. Additional analysis pertains to computational complexity and noise sensitivity, which are superior to Bayesian techniques based on classical neural networks.

Schmalz, M.; Key, G.

24

Page 1 of 2 `5-Phase' EOS: A Tabular H2O EOS for Shock Physics Codes  

E-print Network

Page 1 of 2 `5-Phase' EOS: A Tabular H2O EOS for Shock Physics Codes Sarah T. Stewart Department-commercial use. 2) Users are expected to validate hydrocode calculations using the tabular EOS EOS should cite the appendix in: Senft, L. E., and S. T. Stewart. Impact Crater Formation in Icy

Stewart, Sarah T.

25

LARGE TABULAR ICEBERGS AND ICE ISLANDS OFF EASTERN CANADA IN 2001-2003 AND THEIR PROBABLE SOURCE  

Microsoft Academic Search

In 2002 and 2003, offshore operators on the Grand Banks reported an unusually large number of ice islands and large tabular icebergs up to 20 million tonnes, with drafts of 65 to 80m. This paper describes sightings of large tabular icebergs and ice islands in 2001 to 2003 north of the Grand Banks, from Lancaster Sound in the Canadian Arctic

I. K. Peterson

26

9 CFR 205.102 - Name of person subjecting a farm product to a security interest, on EFS and master list-format.  

Code of Federal Regulations, 2010 CFR

9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Name of person subjecting a farm product to a security interest, on EFS...list-format. 205.102 Section 205.102 Animals and Animal Products GRAIN...

2010-01-01

27

Time-dependent Behaviour of Deep Level Tabular Excavations in Hard Rock  

Microsoft Academic Search

Summary   Although hard rock is not usually associated with large creep deformation, significant time-dependent behaviour is observed\\u000a in the tabular excavations of the South African gold mines. Time-dependent closure data was collected in stopes of the Ventersdorp\\u000a Contact Reef and Vaal Reef. This data typically consists of a primary closure phase after blasting, followed by a steady-state\\u000a closure phase. This

D. F. Malan

1999-01-01

28

The origin and significance of large, tabular dunite bodies in the Trinity peridotite, northern California  

NASA Astrophysics Data System (ADS)

Kilometer-sized, tabular dunite bodies are contained within harzburgite, lherzolite and plagioclase lherzolite host rocks in the Trinity peridotite, northern California. An igneous origin for the dunite by crystal fractionation of olivine from a melt is suggested by their tabular shapes, clots of poikilitic clinopyroxene grains, chromite pods, and by analogy to dunite bodies in the Samail and Vourinos ophiolites (Hopson et al. 1981; Harkins et al. 1980; Moores 1969). However, structures and systematic variations in mineralogy and mineral chemistry suggest that at least the marginal few meters of the bodies are residues produced by extraction of a basaltic component from a plagioclase lherzolite protolith. A model is suggested in which a picritic melt ascended through the upper mantle in vertically oriented channels. Part of the dunite in the tabular bodies was produced by fractional crystallization of olivine from the melt. Additional dunite at the margins of the bodies was formed by extraction of a basaltic component from plagioclase lherzolite wall-rocks during partial assimilation by the picritic melt. The latter process is similar to the “wall-rock reaction” discussed by Green and Ringwood (1967) and is essentially zone refining of the the mantle wall rocks by the migrating melt. It is significant because it suggests a mechanism in addition to fractional crystallization for enrichment of incompatible elements in basalts.

Quick, James E.

1982-03-01

29

Use of an Audit Program to Improve Confidentiality Protection of Tabular Data at the Bureau of Labor Statistics.  

National Technical Information Service (NTIS)

U.S. Statistical Agencies develop disclosure avoidance processes to ensure that individually identifiable data can not be detected in the published tabular tables from confidential data. The Disclosure Audit System (DAS) is software that uses linear progr...

R. Powers, S. Cohen

2008-01-01

30

The breakup of large tabular icebergs - direct observations and theoretical considerations  

NASA Astrophysics Data System (ADS)

Peter Wadhams and Till Wagner Dept. of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge. We review the factors governing the stability, dynamics and decay of icebergs and describe areas where current models are inadequate. These include questions such as draft changes in capsizing icebergs; iceberg trajectory modelling; the melt rate of the ice underside and ways of reducing it; and wave-induced flexure and its role in the break-up of tabular icebergs. In July 2012 the authors worked on a very large (42 sq km) tabular iceberg in Baffin Bay, which had calved from the Petermann Glacier in NW Greenland. We measured incoming swell spectrum and the iceberg response; also the role of buoyancy forces due to erosion of a waterline wave cut and the creation of an underwater ram. The iceberg broke up while we were on it, allowing an instrumental measurement of the calving event. The experiments were included in the BBC-2 film 'Operation Iceberg' shown on Nov 1 2012 and repeated on Nov 18. We conclude that two processes interacted in the break-up event: increased bending stress due to buoyancy of underwater rams; and direct flexural strain due to incidence of ocean swell. Implications for icebergs in the open sea are estimated.

Wadhams, P.

2013-12-01

31

CAP: A Computer Code for Generating Tabular Thermodynamic Functions from NASA Lewis Coefficients  

NASA Technical Reports Server (NTRS)

For several decades the NASA Glenn Research Center has been providing a file of thermodynamic data for use in several computer programs. These data are in the form of least-squares coefficients that have been calculated from tabular thermodynamic data by means of the NASA Properties and Coefficients (PAC) program. The source thermodynamic data are obtained from the literature or from standard compilations. Most gas-phase thermodynamic functions are calculated by the authors from molecular constant data using ideal gas partition functions. The Coefficients and Properties (CAP) program described in this report permits the generation of tabulated thermodynamic functions from the NASA least-squares coefficients. CAP provides considerable flexibility in the output format, the number of temperatures to be tabulated, and the energy units of the calculated properties. This report provides a detailed description of input preparation, examples of input and output for several species, and a listing of all species in the current NASA Glenn thermodynamic data file.

Zehe, Michael J.; Gordon, Sanford; McBride, Bonnie J.

2001-01-01

32

CAP: A Computer Code for Generating Tabular Thermodynamic Functions from NASA Lewis Coefficients. Revised  

NASA Technical Reports Server (NTRS)

For several decades the NASA Glenn Research Center has been providing a file of thermodynamic data for use in several computer programs. These data are in the form of least-squares coefficients that have been calculated from tabular thermodynamic data by means of the NASA Properties and Coefficients (PAC) program. The source thermodynamic data are obtained from the literature or from standard compilations. Most gas-phase thermodynamic functions are calculated by the authors from molecular constant data using ideal gas partition functions. The Coefficients and Properties (CAP) program described in this report permits the generation of tabulated thermodynamic functions from the NASA least-squares coefficients. CAP provides considerable flexibility in the output format, the number of temperatures to be tabulated, and the energy units of the calculated properties. This report provides a detailed description of input preparation, examples of input and output for several species, and a listing of all species in the current NASA Glenn thermodynamic data file.

Zehe, Michael J.; Gordon, Sanford; McBride, Bonnie J.

2002-01-01

33

A quantitative model of ground-water flow during formation of tabular sandstone uranium deposits  

USGS Publications Warehouse

Presents a quantitative simulation of regional groundwater flow during uranium deposition in the Westwater Canyon Member and Jackpile Sandstone Member of the Upper Jurassic Morrison Formation in the San Juan basin. Topographic slope, shoreline position, and density contrasts in the lake and pore fluids controlled the directions of flow and recharge-discharge areas. The most important results for uranium ore deposit formation are that regional groundwater discharged throughout the basin, regional discharge was concentrated along the shore line or playa margin, flow was dominantly gravity driven, and compaction dewatering was negligible. A strong association is found between the tabular sandstone uranium deposits and major inferred zones of mixed local and regional groundwater discharge. -from Author

Sanford, R. F.

1994-01-01

34

A Simple Tool for Integration and Differentiation of Tabular Values in Microsoft Excel  

NASA Astrophysics Data System (ADS)

There are many software alternatives for analyzing experimental data in our physics teaching. I prefer to use Excel® because of its flexibility and widespread use elsewhere in our society. Whatever our students will work with in their future career, they almost certainly will have access to a spreadsheet. For a long time I have missed a tool for integrating and differentiating tabular values in Excel. For every new version I thought it would appear, but it did not. Such a tool could also be useful if you analyze data from other sources than your own experiment, for example, data from the Internet. Therefore, I have written a simple tool that can be integrated seamlessly into Excel as an add-in. It is written in Excels powerful macro language Microsoft Visual Basic for Applications. The tool can be downloaded online and there are two versions of it: one for Excel 2003 and one for Excel 2007/2010.

Haugland, Ole Anton

2011-12-01

35

Tabular water properties interface for Hydra-TH : CASL THM.CFD.P6.03 milestone report.  

SciTech Connect

Completion of the CASL L3 milestone THM.CFD.P6.03 provides a tabular material properties capability to the Hydra code. A tabular interpolation package used in Sandia codes was modified to support the needs of multi-phase solvers in Hydra. Use of the interface is described. The package was released to Hydra under a government use license. A dummy physics was created in Hydra to prototype use of the interpolation routines. Finally, a test using the dummy physics verifies the correct behavior of the interpolation for a test water table. 3

Carpenter, John H.; Belcourt, Noel

2013-04-01

36

Effects of Rigid Body Collisions and Tide-Forced Drift on Large Tabular Icebergs of the Antarctic  

E-print Network

1 Effects of Rigid Body Collisions and Tide-Forced Drift on Large Tabular Icebergs of the Antarctic ICEBERGS #12;2 Abstract. Following the calving of an iceberg from an ice shelf, many collisions between the new iceberg and the remaining shelf can occur as the iceberg responds to time-varying oceanic

Macayeal, Douglas R.

37

The table lens: merging graphical and symbolic representations in an interactive focus+context visualization for tabular information  

Microsoft Academic Search

We present a new visualization, called the Table Lens, for visualizing and making sense of large tables. The visual- ization uses a focus+context (fisheye) technique that works effectively on tabular information because it allows display of crucial label information and multiple distal focal areas. In addition, a graphical mapping scheme for depicting table contents has been developed for the most

Ramana Rao; Stuart K. Card

1994-01-01

38

Geochemical properties of the water-snow-ice complexes in the area of Shokalsky glacier, Novaya Zemlya, in relation to tabular ground-ice formation  

Microsoft Academic Search

Tabular (massive) ground ice in periglacial areas of the Russian Arctic (Barents and Kara Sea coasts) is considered to be a remnant of past glacial epochs and is thus used as proof of the glacial extent. In this paper, we argue that the origin of these tabular ice bodies, which can be used as archives of specific climatic conditions and

M. O. Leibman; S. M. Arkhipov; D. D. Perednya; A. S. Savvichev; B. G. Vanshtein; H. W. Hubberten

2005-01-01

39

Operations Support of Phase 2 Integrated Demonstration In Situ Bioremediation. Volume 2, Final report: Data in tabular form, Disks 2,3,4  

SciTech Connect

This document consists solely of data acquired during phase 2 of the integrated demonstration project concerning in situ bioremediation performed at the Savannah River Site, Aiken, South Carolina. The data is presented in tabular form.

Hazen, T.C. [Westinghouse Savannah River Co., Aiken, SC (United States)

1993-09-01

40

Big-Bang reaction rates within the R-matrix model  

NASA Astrophysics Data System (ADS)

We use the R-matrix theory to fit S-factor data on nuclear reactions involved in Big Bang nucleosynthesis. We derive the reaction rates with associated uncertainties, which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats (available at http://pntpm3.ulb.ac.be/bigbang).

Descouvemont, P.; Adahchour, A.; Angulo, C.; Coc, A.; Vangioni-Flam, E.

2005-07-01

41

Google matrix 1 Google matrix  

E-print Network

Google matrix 1 Google matrix A Google matrix is a particular stochastic matrix that is used by Google's PageRank algorithm. The matrix represents a graph with edges representing links between pages. The rank of each page can be generated iteratively from the Google matrix using the power method. However

Shepelyansky, Dima

42

Google matrix 1 Google matrix  

E-print Network

Google matrix 1 Google matrix Fig.1. Google matrix of Wikipedia articles network, written [19]) A Google matrix is a particular stochastic matrix that is used by Google's PageRank algorithm be generated iteratively from the Google matrix using the power method. However, in order for the power method

Shepelyansky, Dima

43

Chapter 2: Tabular Data and Graphical Images in Support of the U.S. Geological Survey National Oil and Gas Assessment - The Wind River Basin Province  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on this CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files) because of the number and variety of platforms and software available.

Klett, T. R.; Le, P. A.

2007-01-01

44

Tabular Summary of the Third Follow-Up Questionnaire Data. Volume 1 [and] Volume 2 [and] Volume 3 [and] Volume 4. Sponsored Report Series NCES 79-228.  

ERIC Educational Resources Information Center

Tabular summaries of the 153 numerical responses to the Second Followup Questionnaire items of the National Longitudinal Study of the High School Class of 1972 are presented--20,872 individuals responded. These items summarize participants' educational experiences and occupational attainments from October 1973 to October 1974; continuing or…

Peng, Samuel S.; And Others

45

Martin et al., Iceberg Interactions at Cape Adare 1 Kinematic and Seismic Analysis of Giant Tabular Iceberg Breakup at Cape Adare,  

E-print Network

Martin et al., Iceberg Interactions at Cape Adare 1 Kinematic and Seismic Analysis of Giant Tabular Iceberg Breakup at Cape Adare, Antarctica Seelye Martin1 , Robert Drucker1 , Richard Aster2 , Fred Davey3 60637, USA Short Title: Iceberg Interactions at Cape Adare POST-REVIEW REVISION Thursday, 21 January

Boyce, C. Kevin

46

Matrix Operations  

NSDL National Science Digital Library

Created by Lewis Blake and David Smith of the Connected Curriculum Project, the purposes of this module are to experiment with matrix operations, especially multiplication, inversion, and determinants, and to explore applications to solving systems of linear equations. In the process of studying these matrix operations, we will learn how to use a helper application to carry out matrix computations.

Blake, Lewis; Smith, David

2010-06-24

47

Medical Matrix  

NSDL National Science Digital Library

Medical Matrix is a Web resource that offers a database of Internet clinical medicine resources. Medical Matrix categorizes resources by disease, specialty, and other interest areas. It is designed as a "home page" for a physician's or healthworker's computer. Medical Matrix is a project of the Internet Working Group of the American Medical Informatics Association.

48

Matrix Operations  

NSDL National Science Digital Library

Created by Lewis Blake and David Smith for the Connected Curriculum Project, the purposes of this module are to experiment with matrix operations, espcially multiplication, inversion, and determinants, and to explore applications to solving systems of linear equations. In the process of studying these matrix operations, we will learn how to use a helper application to carry out matrix computations. This is one of a much larger set of learning modules hosted by Duke University.

Blake, Lewis; Smith, David

2010-04-29

49

Matrix Metalloproteinases  

PubMed Central

Articles on tumor invasion, metastasis, and angiogenesis in normal and disease states have been well represented among the pages of The American Journal of Pathology. In addition to exciting interest in a variety of disease processes, these studies have been central in defining the emerging field in cancer research known as the tumor microenvironment. Early studies in this field established the importance of the extracellular matrix on tumor cell growth and differentiation. With time, the role of the extracellular matrix and matrix metalloproteinases in the regulation of tumor invasion, metastasis, and angiogenesis was recognized, and AJP has published seminal articles in this field. Moreover, recent studies show evidence for a role of matrix metalloproteinases in the regulation of inflammation within tumor lesions, making the targeting of matrix metalloproteinases in cancer therapy even more complex. This review attempts to summarize the contribution of AJP to some of the key changes that have led to the evolution of this field. PMID:23063657

Shuman Moss, Laurie A.; Jensen-Taubman, Sandra; Stetler-Stevenson, William G.

2013-01-01

50

Modeling State-Space Aeroelastic Systems Using a Simple Matrix Polynomial Approach for the Unsteady Aerodynamics  

NASA Technical Reports Server (NTRS)

A simple matrix polynomial approach is introduced for approximating unsteady aerodynamics in the s-plane and ultimately, after combining matrix polynomial coefficients with matrices defining the structure, a matrix polynomial of the flutter equations of motion (EOM) is formed. A technique of recasting the matrix-polynomial form of the flutter EOM into a first order form is also presented that can be used to determine the eigenvalues near the origin and everywhere on the complex plane. An aeroservoelastic (ASE) EOM have been generalized to include the gust terms on the right-hand side. The reasons for developing the new matrix polynomial approach are also presented, which are the following: first, the "workhorse" methods such as the NASTRAN flutter analysis lack the capability to consistently find roots near the origin, along the real axis or accurately find roots farther away from the imaginary axis of the complex plane; and, second, the existing s-plane methods, such as the Roger s s-plane approximation method as implemented in ISAC, do not always give suitable fits of some tabular data of the unsteady aerodynamics. A method available in MATLAB is introduced that will accurately fit generalized aerodynamic force (GAF) coefficients in a tabular data form into the coefficients of a matrix polynomial form. The root-locus results from the NASTRAN pknl flutter analysis, the ISAC-Roger's s-plane method and the present matrix polynomial method are presented and compared for accuracy and for the number and locations of roots.

Pototzky, Anthony S.

2008-01-01

51

Matrix stone.  

PubMed

Matrix stone is a rare form of renal calculi, and it is often difficult to make an exact preoperative diagnosis. To our knowledge, we reported the first case of matrix stones which received magnetic resonance imaging (MRI) for image study. They showed hypointense signal in T1-weighted images and slight hyperintense signal in T2-weighted images. No obvious contrast enhancement was found after gadolinium administration in T1-weighted images. Besides, postoperative study of computerized tomography (CT) for matrix stones also showed the characteristic of soft tissue densities by measuring the Hounsfield units. We think our experiences may provide some help for the diagnosis of matrix stones when someone encounters the same situation and may prevent overtreatment due to misdiagnosis as malignancy. PMID:14501375

Liu, Chia-Chu; Li, Ching-Chia; Shih, Ming-Chen; Chou, Yii-Her; Huang, Chun-Hsiung

2003-01-01

52

Matrix Metalloproteinases  

PubMed Central

The most common cause of failure of retinal reattachment surgery is formation of fibrocellular contractile membranes on both surfaces of the neuroretina. This intraocular fibrosis, known as proliferative vitreoretinopathy, results in a blinding tractional retinal detachment because of the contractile nature of the membrane. Contractility is a cell-mediated event that is thought to be dependent on locomotion and adhesion to the extracellular matrix. Interactions between cells and the extracellular matrix can be influenced by matrix metalloproteinases (MMPs) and we investigated the role of MMPs in two in vitro models (two- and three-dimensional) of human retinal pigment epithelial (RPE) cell-mediated contraction. MMP activity was detected using enzyme-linked immunosorbent assays and zymography techniques that revealed MMP-1, -2, -3, and -9 positivity during the collagen matrix contraction assays. RPE-populated collagen matrix contraction (three-dimensional) was inhibited using a cocktail of anti-MMP antibodies and with Galardin (a broad-spectrum MMP inhibitor). Galardin inhibition was dose-dependent, reversible, and dependent on cell number. MMP inhibitors had no effect on contraction when RPEs were seeded on two-dimensional collagen matrices or on cellular adhesion to collagen type I. Our results suggest that MMP activity may be required for three-dimensional but not two-dimensional RPE-collagen matrix contraction. PMID:11583981

Sheridan, Carl M.; Occleston, Nick L.; Hiscott, Paul; Kon, Chee H.; Khaw, Peng T.; Grierson, Ian

2001-01-01

53

Extracellular matrix.  

PubMed

A succinct overview of recent results on the biochemistry of extracellular matrix (ECM) is presented. The rapid expansion of this discipline over the best decades renders impossible to give an even approximately complete coverage of matrix biology. Some selected results concerning the four major families of macromolecules composing the ECM, that is, collagens (14 types described), elastin(s), proteoglycans and structural glycoproteins (especially fibronectin) are described. Special attention is directed to a crucial aspect of matrix biology: cell-matrix interactions. A number of cell membrane receptors were recently described mediating the two way information flow from the cells to the matrix via the 'programme' of ECM synthesis coded in the genome and unfolding during differentiation and from the ECM to the cells through the membrane receptors which contact the cytoskeleton. One of them at least, the elastin receptor was shown to be linked through a G-protein-phospholipase C-IP3 mediated relay to the regulation of intracellular calcium. Modifications of the ECM will therefore influence cell behaviour. Derangements of this informational feed back mechanisms appear to be involved in most age-related connective tissue diseases. PMID:2166694

Labat-Robert, J; Bihari-Varga, M; Robert, L

1990-08-01

54

Radon constrains the transit time of springs water at the border between tabular Middle Atlas and the Sais Basin (Morocco)  

NASA Astrophysics Data System (ADS)

The tabular Middle Atlas (TMA) is an important fractured karstic reservoir in northern Morocco constituted by Liassic limestones and dolomites with a nearly sub-horizontal attitude, overlying basalts, shales and evaporates of Triassic age, as well as Paleozoic anchi-metamorphic schists. The zone is characterised by relative abundant rainfall (700 mm/y) and the absence of a surface watershed, which lead to an important groundwater reservoir hosted in the karstic (k-) aquifer. TMA is bordered to the North by extensive graben-like, normal, northward, fault-systems, which burden the Karstic formations under Plio-quaternary sediments at the Sais Basin border. At this limit, several important springs of high water-quality occur at the northernmost outcropping Lias limestone, which is overlaid in some areas by quaternary travertines. Two of these springs in particular, Bittit and Ribaa springs, provide almost drinking water for the town of Meknes (0.7 Million inhabitants), for local population and agriculture. These springs experienced a significant drop in water flow-rate in the last decades. Although the main origin of this water is certainly the k-aquifer, the drop in water-table raises several questions regarding the modality of water transport (influence of fractured and karstic systems in particular) and the possible participations of other groundwater reservoirs, which may deteriorate the high water-quality. A recent study has been carried out to shed some light on these questions, by using geochemical methods (K, Mg, Na, Ca, Fe, Mn, Ba, Sr, As, Sb, Hg, HCO3, SO4, NO3, Cl, Br, delta18-O, deltaD, Rn, EC, O2, pH, Eh, Temp). Constraints on the groundwater flow-path have been obtained by using a radon- hydrochemical- isotopic characterisation of spring waters. Here we report the results of the first geochemical sample collection (November 09). Several springs in the TMA yield Mg-Ca HCO3 rich water equilibrated with limestone and dolomite, having a very similar Rn activity of 3000 Bq/m3, unrelated to spring altitude. Similar radon activity is also found in a deep well in the Lias-confined aquifer of the Sais Basin and is hence considered to be the steady state activity in k-aquifer. Other springs situated at lower altitude yield more mineralised water (EC = 1200 uS/cm), richer in Na, K, Cl and Rn (15000 Bq/m3). These waters partially interacted with a non-karstic aquifer, most probably the deeper underlying Paleozoic schists (p-aquifer), as suggested by hydro chemical similarity with a water sample collected from a well in these shists. Since such water springs-out of Liassic carbonates, the measured Rn activity probably differs from the equilibrium activity achieved in the underlying p-aquifer, depending on the transit time from p-aquifer and the radon half-life (3.8 days). Furthermore, three other springs have hydrochemical characteristics intermediate between p- and k-aquifers, suggesting that a binary mixing of these waters occurred, either in the k- or in the p- aquifer. In principle, if the groundwater mixing occurred in k-aquifer, unsupported Rn activity would be lower than the activity expected from the binary mixing because of the time elapsed since the mixing occurred. The data show on the contrary that the mixed water has Rn activity higher than the expected activity calculated from the mixing. This suggests that groundwater mixing occurred in the p-aquifer. The excess of radon relatively to the expected activity calculated after the mixing, is interpreted to result from Rn radioactive ingrowth during the residence time in the p-aquifer, followed by radon decay occurred during uplift from p-aquifer to the spring in the Liassic carbonates. With this simple model, the measured Rn excess constraints the total time elapsed since the beginning of interaction with the p-aquifer on a time scale of 2 weeks. Remote sensed imaging of the area evidences that these "mixed" springs lies on important tectonic alignments, which suggest that fractures system could play a role in the fast upwelling of groundwater.

Mayer, Adriano; Rouai, Mohammed; Saracco, Ginette; Dekayir, Abdelilak; Miche, Héléne

2010-05-01

55

Verification of model simulated mass balance, flow fields and tabular calving events of the Antarctic ice sheet against remotely sensed observations  

NASA Astrophysics Data System (ADS)

The Antarctic ice sheet (AIS) has the greatest potential for global sea level rise. This study simulates AIS ice creeping, sliding, tabular calving, and estimates the total mass balances, using a recently developed, advanced ice dynamics model, known as SEGMENT-Ice. SEGMENT-Ice is written in a spherical Earth coordinate system. Because the AIS contains the South Pole, a projection transfer is performed to displace the pole outside of the simulation domain. The AIS also has complex ice-water-granular material-bedrock configurations, requiring sophisticated lateral and basal boundary conditions. Because of the prevalence of ice shelves, a `girder yield' type calving scheme is activated. The simulations of present surface ice flow velocities compare favorably with InSAR measurements, for various ice-water-bedrock configurations. The estimated ice mass loss rate during 2003-2009 agrees with GRACE measurements and provides more spatial details not represented by the latter. The model estimated calving frequencies of the peripheral ice shelves from 1996 (roughly when the 5-km digital elevation and thickness data for the shelves were collected) to 2009 compare well with archived scatterometer images. SEGMENT-Ice's unique, non-local systematic calving scheme is found to be relevant for tabular calving. However, the exact timing of calving and of iceberg sizes cannot be simulated accurately at present. A projection of the future mass change of the AIS is made, with SEGMENT-Ice forced by atmospheric conditions from three different coupled general circulation models. The entire AIS is estimated to be losing mass steadily at a rate of ~120 km3/a at present and this rate possibly may double by year 2100.

Ren, Diandong; Leslie, Lance M.; Lynch, Mervyn J.

2013-06-01

56

Chapter 3: Tabular Data and Graphical Images in Support of the U.S. Geological Survey National Oil and Gas Assessment - Western Gulf Province, Smackover-Austin-Eagle Ford Composite Total Petroleum System (504702)  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on this CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Because of the number and variety of platforms and software available, graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files).

Klett, T. R.; Le, P. A.

2006-01-01

57

Monastic Matrix  

NSDL National Science Digital Library

One of the aims of the Monastic Matrix website is to disseminate research to both lay people and scholars about the "participation of Christian women in the religion and society of medieval Europe." This website allows visitors to view artwork, archaeology, stained glass, architecture, and textiles. By clicking on the link "Figurae" on the right hand side menu, visitors can browse these digital images by "title", "century", "community", and "image type". The "Beata Antonia", found by browsing "community", treats viewers to many beautiful 16th century Italian frescos. After visitors have had their fill of images, they might try the "Commentaria" section, which contains modern scholarly analyses. They should also take a look at the "Cartularium" which is a digital library of primary sources. Although many of the documents are in Latin, French, or other languages, some have been translated into English.

58

Tabular Summary of the Second Follow-Up Questionnaire Data 2 1/2 Years After High School. Volume 1 [and] Volume 2. Sponsored Reports Series. NCES 77-263 Reprint. Reprinted February 1979.  

ERIC Educational Resources Information Center

Tabular summaries of the 158 numerical responses to the Third Followup Questionnaire items of the National Longitudinal Study of the High School Class of 1972 are presented--20,092 individuals responded. These items summarize participants' educational experience and occupational attainments from October 1974 to October 1976; continuing or revised…

Peng, Samuel S.; Holt, Mary M.

59

A matrix lower bound  

SciTech Connect

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

Grcar, Joseph F.

2002-02-04

60

Crystal matrix and crystal double matrix spectroscopy  

NASA Astrophysics Data System (ADS)

Infrared and Raman spectra of matrix isolated ions in crystalline solids display the normal modes of these units with respect to the symmetry of the respective lattice sites. Hence, they give information on all structure changes of the incorporated entities (energetic distortion), the amount of intramolecular coupling of the respective stretching modes, and symmetry and potential at the host crystal lattice sites. In the case of neat compounds, this information is hidden by collective solid-state effects. Assignment of the modes of matrix isolated guest ions can be performed by Raman single crystal experiments. If two different matrix isolated entities in a crystalline matrix come into contact forming complexes (double matrix spectroscopy) symmetry and frequencies of the modes of the guest ions are additionally changed. In the case of solid hydrates, thus the influence of metal ions and anions on the strength of hydrogen bonds (cooperative, competitive, and synergetic effects) can be analysed in detail. Examples of crystal matrix and crystal double matrix spectroscopic experiments are presented on orthorhombic halates M( XO 3) 2, monoclinic halate monohydrates M( XO 3) 2·H 2O ( M=Sr, Ba, Pb and X=Cl, Br, I), and likewise monoclinic kieserite-type compounds MXO 4·H 2O ( M=Mn, Co, Ni, Zn, and X=S, Se) with matrix-isolated XO 3-, XO 42-, and M2+ guest ions and HDO guest molecules.

Lutz, H. D.

2004-10-01

61

Algorithms for matrix completion  

E-print Network

We consider collaborative filtering methods for matrix completion. A typical approach is to find a low rank matrix that matches the observed ratings. However, the corresponding problem has local optima. In this thesis, we ...

Xin, Yu, Ph. D. Massachusetts Institute of Technology

2012-01-01

62

Matrix differentiation formulas  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

63

Fire Model Matrix  

NSDL National Science Digital Library

The Fire Model Matrix is an on-line resource that presents four fire community models in a matrix that facilitates the exploration of the characteristics of each model. As part of the Advanced Fire Weather Forecasters Course, this matrix is meant to sensitize forecasters to the use of weather data in these fire models to forecast potential fire activity.

Comet

2008-02-05

64

Matrix-Matrix Multiplication on Heterogeneous Platforms  

Microsoft Academic Search

In this paper, we address the issue of implementing matrix-matrix multiplication on heterogeneous platforms. We target two different classes of heterogeneous computing resources: heterogeneous networks of workstations, and collections of heterogeneous clusters. Intuitively, the problem is to load balance the work with different-speed resources while minimizing the communication volume. We formally state this problem and prove its NP-completeness. Next we

Olivier Beaumont; Vincent Boudet; Fabrice Rastello; Yves Robert

2000-01-01

65

Testing the apatite-magnetite geochronometer: U-Pb and 40Ar/ 39Ar geochronology of plutonic rocks, massive magnetite-apatite tabular bodies, and IOCG mineralization in Northern Chile  

NASA Astrophysics Data System (ADS)

Detailed zircon and apatite U-Pb dating and 40Ar/ 39Ar dating of actinolite have been carried out on the Carmen-Sierra Aspera Kiruna type magnetite-apatite and iron oxide Cu-Au (IOCG) district in the Coastal Cordillera of northern Chile (˜26°S). They define a precise succession of magmatic and hydrothermal events associated with early Cretaceous Andean magmatism. Apatite and magnetite from a magnetite-apatite tabular body with intergrowth texture in the Carmen deposit yield a total Pb-U isochron age of 131.0 ± 1.0 Ma. This result is the first direct dating of magnetite-apatite mineralization in an early Andean deposit, and the age coincides with zircon ages of a quartz diorite stock that partially hosts mineralization (130.6 ± 0.3 Ma). Magnetite from the studied tabular body contains only small amounts of radiogenic Pb and serves to constrain the initial common Pb isotopic composition. The high degree of correlation suggests that both minerals closed for Pb diffusion at essentially the same time and at a relatively high temperature (close to that of zircon), making the apatite-magnetite pair a reliable geochronometer for igneous or hydrothermal crystallization. Zircon from the Sierra Aspera composite pluton yields ages between 131.3 ± 0.3 Ma and 127.4 ± 0.1 Ma, clearly resolving the timing of intrusion of discrete intrusive phases. Actinolite 40Ar/ 39Ar ages partially overlap the ages of plutonic phases of the Sierra Aspera pluton, but are younger than the magnetite-apatite tabular body. The initial Pb isotopic composition of the melts and/or fluids from which the magnetite-apatite tabular bodies crystallized is very similar to the primitive Pb isotopic composition of granitic magmas associated with early Cretaceous plutons measured in K-feldspar. The Pb isotopic correspondence, combined with the temporal and spatial association between magnetite-apatite mineralization and the dioritic-quartz dioritic magmatism, strongly suggests a genetic relationship between early Cretaceous continental arc magmatism, massive magnetite-apatite deposits, and IOCG mineralization.

Gelcich, Sergio; Davis, Donald W.; Spooner, Edward T. C.

2005-07-01

66

Nanocrystal doped matrixes  

DOEpatents

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

Parce, J. Wallace (Palo Alto, CA); Bernatis, Paul (Sunnyvale, CA); Dubrow, Robert (San Carlos, CA); Freeman, William P. (San Mateo, CA); Gamoras, Joel (Vallejo, CA); Kan, Shihai (San Jose, CA); Meisel, Andreas (Redwood City, CA); Qian, Baixin (Sunnyvale, CA); Whiteford, Jeffery A. (Belmont, CA); Ziebarth, Jonathan (Palo Alto, CA)

2010-01-12

67

Automatic switching matrix  

DOEpatents

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

Schlecht, Martin F. (Cambridge, MA); Kassakian, John G. (Newton, MA); Caloggero, Anthony J. (Lynn, MA); Rhodes, Bruce (Dorchester, MA); Otten, David (Newton, MA); Rasmussen, Neil (Sudbury, MA)

1982-01-01

68

Optical matrix processors  

NASA Astrophysics Data System (ADS)

The optical implementation of matrix-algebra operations is examined in an analytical review. Analog procedures for basic operations such as scalar-vector multiplication, inner and outer vector products, and vector-matrix and matrix-matrix multiplication are explained; the computational throughput for these operations is analyzed; digital encoding techniques to improve the accuracy of the operations are discussed; and higher-order operations such as L-U decomposition and Gram-Schmidt orthogonalization are considered. Image-processing and pattern-recognition applications (transformation, data compression, feature extraction, and image synthesis) are briefly characterized.

Athale, Ravindra A.

69

Last Time: Matrix of Linear Transformation Matrix Algebra Matrix Algebra  

E-print Network

= 0 1 ... 0 , . . . , en = 0 0 ... 1 Then x = x1e1 + x2e2 + . . . + xnen is a linear Then x = x1e1 + x2e2 + . . . + xnen is a linear combination of the standard basis. Since T is a linear transformation, T(x) = T(x1e1+x2e2+. . . xnen) = x1T(e1)+x2T(e2)+. . . xnT(en) 3/14 #12;Last Time: Matrix

Bigelow, Stephen

70

Matrix metalloproteinases in tuberculosis.  

PubMed

Tuberculosis (TB) remains a global health pandemic. Infection is spread by the aerosol route and Mycobacterium tuberculosis must drive lung destruction to be transmitted to new hosts. Such inflammatory tissue damage is responsible for morbidity and mortality in patients. The underlying mechanisms of matrix destruction in TB remain poorly understood but consideration of the lung extracellular matrix predicts that matrix metalloproteinases (MMPs) will play a central role, owing to their unique ability to degrade fibrillar collagens and other matrix components. Since we proposed the concept of a matrix degrading phenotype in TB a decade ago, diverse data implicating MMPs as key mediators in TB pathology have accumulated. We review the lines of investigation that have indicated a critical role for MMPs in TB pathogenesis, consider regulatory pathways driving MMPs and propose that inhibition of MMP activity is a realistic goal as adjunctive therapy to limit immunopathology in TB. PMID:21659415

Elkington, P T; Ugarte-Gil, C A; Friedland, J S

2011-08-01

71

Time rate collision matrix  

SciTech Connect

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

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

1980-02-01

72

Faces of matrix models  

NASA Astrophysics Data System (ADS)

Partition functions of eigenvalue matrix models possess a number of very different descriptions: as matrix integrals, as solutions to linear and nonlinear equations, as ?-functions of integrable hierarchies and as special-geometry prepotentials, as result of the action of W-operators and of various recursions on elementary input data, as gluing of certain elementary building blocks. All this explains the central role of such matrix models in modern mathematical physics: they provide the basic "special functions" to express the answers and relations between them, and they serve as a dream model of what one should try to achieve in any other field.

Morozov, A.

2012-08-01

73

Hybrid matrix amplifier  

DOEpatents

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

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

1995-01-03

74

Constructing matrix geometric means  

E-print Network

In this paper, we analyze the process of “assembling ” new matrix geometric means from existing ones, and show what new means can be found, and what cannot be done because of group-theoretical obstructions. We show that for n = 4 a new matrix mean exists which is simpler to compute than the existing ones. Moreover, we show that for n> 4 the existing strategies of composing matrix means and taking limits of iterations cannot provide a mean computationally simpler than the existing ones.

Federico Poloni

75

Hybrid matrix amplifier  

DOEpatents

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

Martens, Jon S. (Sunnyvale, CA); Hietala, Vincent M. (Placitas, NM); Plut, Thomas A. (Albuquerque, NM)

1995-01-01

76

Pesticide-Exposure Matrix  

Cancer.gov

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

77

Learning with matrix factorizations  

E-print Network

Matrices that can be factored into a product of two simpler matrices can serve as a useful and often natural model in the analysis of tabulated or high-dimensional data. Models based on matrix factorization (Factor Analysis, ...

Srebro, Nathan, 1974-

2004-01-01

78

The Inquiry Matrix  

NSDL National Science Digital Library

One way to advance inquiry in the classroom is to establish a systematic strategy for reflecting on our practice and our students' readiness to engage in increasingly complex scientific reasoning. The Matrix for Assessing and Planning Scientific Inquiry (

Grady, Julie

2010-11-01

79

Chapter 3. Tabular data and graphical images in support of the U.S. Geological Survey National Oil and Gas Assessment--East Texas basin and Louisiana-Mississippi salt basins provinces, Jurassic Smackover Interior salt basins total petroleum system (504902), Cotton Valley group.  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on the CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Because of the number and variety of platforms and software available, graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files).

Klett, T. R.; Le, P. A.

2006-01-01

80

Chapter 6. Tabular data and graphical images in support of the U.S. Geological Survey National Oil and Gas Assessment-East Texas basin and Louisiana-Mississippi salt basins provinces, Jurassic Smackover interior salt basins total petroleum system (504902), Travis Peak and Hosston formations.  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on the CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Because of the number and variety of platforms and software available, graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files).

Geological Survey (U.S.)

2006-01-01

81

Sparse matrix inverse factors  

SciTech Connect

The inverses of matrix factors lend themselves to parallel operations in the direct solution phase of sparse matrix solutions. These inverse factors, given suitable ordering of the equations, are themselves sparse, if less so than the original factors. Partitioning reduces the build-up of nonzero elements in the inverse factors. All of the multiplications required for repeat solutions may be performed in parallel using the inverse factors, with only as many serial steps as twice the number of factors.

Enns, M.K. (Electrocon International, Inc., Ann Arbor, MI (USA)); Tinney, W.F.; Alvarado, F.L. (Wisconsin Univ., Madison, WI (USA))

1990-05-01

82

An MCS Matrix  

NSDL National Science Digital Library

This module includes an interactive MCS Matrix of numerical simulations illustrating the physical processes controlling MCS evolution, as well as an archive of the entire Web module, Mesoscale Convective Systems: Squall Lines and Bow Echoes. Patterned after the CD Module A Convective Storm Matrix, the new MCS Matrix provides learners the opportunity for extensive exploration of the relationship between a MCSs environment and its structure. The matrix is composed of 21 four-dimensional numerical simulations based on the interactions of 10 different hodographs with a common thermodynamic profile. By comparing animated displays of these simulations learners are able to discern the influences of vertical wind shear and the Coriolis Force on MCS structure and evolution. A series of questions guides the exploration and helps to reveal key storm/environment relationships evident in the matrix. The subject matter expert for this module is Dr. Morris Weisman. Note: This module was originally published 5/28/99 as a CD-ROM (v1.0) as dual module along with a local copy of the Web module Mesoscale Convective Systems: Squall Lines and Bow Echoes (v3.0). The CD-ROM version of An MCS Matrix (1.0) works fairly well with Windows 98/ME/NT4/2000 but has reported to be problematic with Windows XP. Windows XP Users of version 1.0 should use the new, Web-based module.

Comet

2003-04-17

83

Regularized matrix regression  

PubMed Central

Summary Modern technologies are producing a wealth of data with complex structures. For instance, in two-dimensional digital imaging, flow cytometry and electroencephalography, matrix-type covariates frequently arise when measurements are obtained for each combination of two underlying variables. To address scientific questions arising from those data, new regression methods that take matrices as covariates are needed, and sparsity or other forms of regularization are crucial owing to the ultrahigh dimensionality and complex structure of the matrix data. The popular lasso and related regularization methods hinge on the sparsity of the true signal in terms of the number of its non-zero coefficients. However, for the matrix data, the true signal is often of, or can be well approximated by, a low rank structure. As such, the sparsity is frequently in the form of low rank of the matrix parameters, which may seriously violate the assumption of the classical lasso. We propose a class of regularized matrix regression methods based on spectral regularization. A highly efficient and scalable estimation algorithm is developed, and a degrees-of-freedom formula is derived to facilitate model selection along the regularization path. Superior performance of the method proposed is demonstrated on both synthetic and real examples. PMID:24648830

Zhou, Hua; Li, Lexin

2014-01-01

84

Matrix interdiction problem  

SciTech Connect

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

Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

2010-01-01

85

Proteolytic remodeling of extracellular matrix  

Microsoft Academic Search

Matrix metalloproteinases and their natural inhibitors are ingredients of a fundamental cellular toolbox for effecting environmental change. These enzymes enable cells to alter their relationship to the environment by directly cleaving structural macromolecules of the extracellular matrix. In addition, evidence is emerging that they also play an important regulatory role in matrix remodeling by catalyzing the processing of inactive matrix

Henning Birkedal-Hansen

1995-01-01

86

Matrix Big Brunch  

E-print Network

Following the holographic description of linear dilaton null Cosmologies with a Big Bang in terms of Matrix String Theory put forward by Craps, Sethi and Verlinde, we propose an extended background describing a Universe including both Big Bang and Big Crunch singularities. This belongs to a class of exact string backgrounds and is perturbative in the string coupling far away from the singularities, both of which can be resolved using Matrix String Theory. We provide a simple theory capable of describing the complete evolution of this closed Universe.

J. Bedford; C. Papageorgakis; D. Rodriguez-Gomez; J. Ward

2007-02-12

87

Probabilistic Matrix Factorization  

Microsoft Academic Search

Many existing approaches to collaborative filtering can nei ther handle very large datasets nor easily deal with users who have very few ratings. In this paper we present the Probabilistic Matrix Factorization (PMF) model which scales linearly with the number of observations and, more importantly, performs well on the large, sparse, and very imbalanced Netflix dataset. We furth er extend

Ruslan Salakhutdinov; Andriy Mnih

2007-01-01

88

Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Basin Characteristics, 2002 Geospatial_Data_Presentation_Form: tabular digital data  

USGS Publications Warehouse

This tabular data set represents basin characteristics for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). These characteristics are reach catchment shape index, stream density, sinuosity, mean elevation, mean slope and number of road-stream crossings. The source data sets are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011) and the U.S. Census Bureau's TIGER/Line Files (U.S. Census Bureau,2006). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

89

Matrix techniques in colorimetry.  

PubMed

The usual (geometric) procedure to determine the chromaticity coordinates of a color that results from the additive mixture of colored stimuli is to plot the coordinates of these stimuli on the CIE chromaticity diagram and apply the center-of-gravity rule. This procedure, however, may become inaccurate and cumbersome if more than just a few colored stimuli are mixed in various proportions. An alternate method is presented that uses matrix techniques to solve problems related to colorimetry simply and accurately. PMID:7386588

Spiegler, J B

1980-04-01

90

Optical shutter switching matrix  

NASA Technical Reports Server (NTRS)

The interface switching systems are discussed which are related to those used in the Space Shuttle ground control system, transmission systems, communications systems, and airborne radar electronic countermeasure systems. The main goal is to identify a need that exists throughout the comprehensive information processing and communications disciplines supporting the Space Shuttle and Space Station programs, and introduce one viable approach to satisfy that need. The proposed device, described in NASA patent entitled 'Optical Shutter Switch Matrix', is discussed.

Grove, Charles H.

1991-01-01

91

Matrix string theory  

Microsoft Academic Search

Via compactification on a circle, the matrix mode] of M-theory proposed by Banks et a]. suggests a concrete identification between the large N limit of two-dimensional N = 8 supersymmetric Yang-Mills theory and type IIA string theory. In this paper we collect evidence that supports this identification. We explicitly identify the perturbative string states and their interactions, and describe the

Robbert Dijkgraaf; Erik Verlinde; Herman L Verlinde

1997-01-01

92

A Mathematica script for harmonic oscillator nuclear matrix elements arising in semileptonic electroweak interactions  

E-print Network

Semi-leptonic electroweak interactions in nuclei - such as \\beta decay, \\mu capture, charged- and neutral-current neutrino reactions, and electron scattering - are described by a set of multipole operators carrying definite parity and angular momentum, obtained by projection from the underlying nuclear charge and three-current operators. If these nuclear operators are approximated by their one-body forms and expanded in the nucleon velocity through order |\\vec{p}|/M, where \\vec{p} and M are the nucleon momentum and mass, a set of seven multipole operators is obtained. Nuclear structure calculations are often performed in a basis of Slater determinants formed from harmonic oscillator orbitals, a choice that allows translational invariance to be preserved. Harmonic-oscillator single-particle matrix elements of the multipole operators can be evaluated analytically and expressed in terms of finite polynomials in q^2, where q is the magnitude of the three-momentum transfer. While results for such matrix elements are available in tabular form, with certain restriction on quantum numbers, the task of determining the analytic form of a response function can still be quite tedious, requiring the folding of the tabulated matrix elements with the nuclear density matrix, and subsequent algebra to evaluate products of operators. Here we provide a Mathematica script for generating these matrix elements, which will allow users to carry out all such calculations by symbolic manipulation. This will eliminate the errors that may accompany hand calculations and speed the calculation of electroweak nuclear cross sections and rates. We illustrate the use of the new script by calculating the cross sections for charged- and neutral-current neutrino scattering in ^{12}C.

Wick Haxton; Cecilia Lunardini

2007-06-15

93

Leslie Matrix I Formal Demography  

E-print Network

Leslie Matrix I Formal Demography Stanford Summer Short Course 2006 James Holland Jones Department and Eigenvectors Stanford Summer Short Course: Leslie Matrix I 2 #12;A Simple Example Assume 2 Age case? Stanford Summer Short Course: Leslie Matrix I 3 #12;Figuring Out Age Structure Imagine you start

94

On the Matrix Exponential Function  

ERIC Educational Resources Information Center

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

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

2006-01-01

95

Tabular equation of state for gold  

NASA Astrophysics Data System (ADS)

A new, SESAME-type equation of state (EOS) , suitable for use in hydrodynamic calculations, is described for gold. Pressures, internal energies, and Helmholtz free energies are tabulated on a rectangular temperature-and-density grid, spanning densities from 0 - 36 g/cc, temperatures from 0 - 800 eV, and extending up to pressures of 800 GPa. The EOS is constructed using the standard decomposition of the pressure into a static-lattice cold curve, a thermal nuclear contribution, and a thermal electronic contribution. The cold curve is derived from existing diamond-anvil-cell measurements, the thermal nuclear contribution from the Johnson model, and the thermal electronic contribution using Thomas-Fermi-Dirac theory. Predictions of the new EOS (SESAME 2705) for the cold curve, roomtemperature isotherm, principal Hugoniot, thermal expansion, heat capacity, melt line, and vapor pressure compare favorably with experimental data and are superior to the EOS currently available in the SESAME library (SESAME 2700).

Boettger, Jonathan; Honnell, Kevin G.; Peterson, Jeffrey H.; Greeff, Carl; Crockett, Scott

2012-03-01

96

Tabular Equation of State for Gold  

NASA Astrophysics Data System (ADS)

A new, Sesame-type equation of state (EOS) is described for gold, suitable for use in hydrodynamic calculations. The EOS is tabulated on a rectangular temperature-and- density grid, spanning densities from 0 -- 29 g/cc, temperatures from 0 -- 85,000 K, and extending up to pressures of 1000 GPa. It is constructed using the standard decomposition of the pressure into a static-lattice cold curve, a thermal nuclear contribution, and a thermal electronic contribution. The cold curve is derived from a combination of empirical data and density functional theory, the thermal nuclear contribution from the Johnson model, and the thermal electronic contribution using Thomas-Fermi-Dirac theory. Pressures, internal energies, and Helmholtz free energies are tabulated as functions of temperature and density. Predictions for the room-temperature isotherm, principal Hugoniot, thermal expansion, heat capacity, and vapor pressure are compared with experimental data and with the EOS currently available in the Sesame library (Sesame 2700).

Boettger, Jonathan; Honnell, Kevin; Peterson, Jeffrey; Greeff, Carl; Crockett, Scott

2011-06-01

97

Marine Wave Model Matrix  

NSDL National Science Digital Library

The Marine Wave Model Matrix provides information on the formulation of wave models developed by the National Centers for Environmental Prediction (NCEP) and other modeling centers, including how these models forecast the generation, propagation, and dissipation of ocean waves using NWP model forecasts for winds and near-surface temperature and stability. Additionally, information is provided on data assimilation, post-processing of data, and verfication of wave models currently in operation. Within the post-processing pages are links to forecast output both in graphical and raw form, including links for data downloads. Links to COMET training on wave processes are also provided.

Comet

2006-05-16

98

Delayed beta- and gamma-ray production due to thermal-neutron fission of /sup 239/Pu: tabular and graphical spectral distributions for times after fission between 2 and 14000 sec  

SciTech Connect

Fission-product decay energy-release rates were measured for thermal-neutron fission of /sup 239/Pu. Samples of mass 1 and 5 ..mu..g were irradiated for 1 to 100 s using the fast pneumatic-tube facility at the Oak Ridge Research Reactor. The resulting beta- and gamma-ray emissions were separately counted for times-after-fission between 2 and 14,000 s to yield spectral distributions N(E/sub ..gamma../) vs E/sub ..gamma../ and N(E/sub ..beta../) vs E/sub ..beta../. The gamma-ray spectra were obtained by use of a NaI detector, and the beta-ray spectra were obtained by use of an NE-110 detector with an anticoincidence mantle. The raw data were unfolded to provide spectral distributions of moderate resolution. These distributions are given in graphical and tabular form as differential spectral intensity I(E) (MeV/sup -1/ fission/sup -1/) averaged over gamma-ray energy intervals ranging from 10 keV for E/sub ..gamma../ < 0.18 MeV to 100 keV for E/sub ..gamma../ > 6.8 MeV, and beta-ray energy intervals ranging from 20 keV for E/sub ..beta../ < 0.25 MeV to 160 keV for E/sub ..beta../ > 6.4 MeV. Counting-time intervals ranged from 1 s for times-after-fission (t/sub w/) < 6 s to 4000 s for t/sub w/ approx. 10/sup 4/ s. For comparisons the graphical representations show calculated spectra obtained by use of the CINDER-10 summation code and the ENDF/B-IV fission yield and decay scheme data base. 90 figures, 86 tables.

Dickens, J.K.; England, T.R.; Love, T.A.; McConnell, J.W.; Emergy, J.F.; Northcutt, K.J.; Peelle, R.W.

1980-01-01

99

Structural Basis of Extracellular Matrix Interactions with Matrix Metalloproteinases  

Microsoft Academic Search

\\u000a Interactions of the extracellular matrix (ECM) with domains of matrix metalloproteinases (MMPs) increase their proteolytic\\u000a action upon matrix components. This occurs by multiple structural means. The activating interactions of a partner protein\\u000a with pro-MMP-9 and of GAGs with pro-MMP-7 were reported. The interactions of fibrillar proteins with catalytic domains can\\u000a traverse the breadth of the active site cleft and overflow

Steven R. Van Doren

100

Google matrix of Twitter  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

101

Mixed Mode Matrix Multiplication  

SciTech Connect

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

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

2004-09-30

102

Matrix membranes and integrability  

SciTech Connect

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

Zachos, C. [Argonne National Lab., IL (United States); Fairlie, D. [University of Durham (United Kingdom). Dept. of Mathematical Sciences; Curtright, T. [University of Miami, Coral Gables, FL (United States). Dept. of Physics

1997-06-01

103

Homolumo Gap and Matrix Model  

E-print Network

We discuss a dynamical matrix model by which probability distribution is associated with Gaussian ensembles from random matrix theory. We interpret the matrix M as a Hamiltonian representing interaction of a bosonic system with a single fermion. We show that a system of second-quantized fermions influences the ground state of the whole system by producing a gap between the highest occupied eigenvalue and the lowest unoccupied eigenvalue.

I. Andric; L. Jonke; D. Jurman; H. B. Nielsen

2007-12-21

104

Recycling of aluminum matrix composites  

Microsoft Academic Search

Separation of matrix metals in composites was tried on alumina short fiber-reinforced aluminum and 6061 alloy composites and\\u000a SiC whisker-reinforced 6061 alloy composite for recycling. It is possible to separate molten matrix metals from fibers in\\u000a the composites using fluxes that are used for melt treatment to remove inclusions. About 50 vol pct of the matrix metals was\\u000a separated from

Yoshinori Nishida; Norihisa Izawa; Yukio Kuramasu

1999-01-01

105

Glass matrix armor  

DOEpatents

An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.

Calkins, Noel C. (Los Alamos, NM)

1991-01-01

106

Hybridized polymer matrix composites  

NASA Technical Reports Server (NTRS)

The extent to which graphite fibers are released from resin matrix composites that are exposed to fire and impact conditions was determined. Laboratory simulations of those conditions that could exist in the event of an aircraft crash and burn situation were evaluated. The effectiveness of various hybridizing concepts in preventing this release of graphite fibers were also evaluated. The baseline (i.e., unhybridized) laminates examined were prepared from commercially available graphite/epoxy, graphite/polyimide, and graphite/phenolic materials. Hybridizing concepts investigated included resin fillers, laminate coatings, resin blending, and mechanical interlocking of the graphite reinforcement. The baseline and hybridized laminates' mechanical properties, before and after isothermal and humidity aging, were also compared. It was found that a small amount of graphite fiber was released from the graphite/epoxy laminates during the burn and impact conditions used in this program. However, the extent to which the fibers were released is not considered a severe enough problem to preclude the use of graphite reinforced composites in civil aircraft structure. It also was found that several hybrid concepts eliminated this fiber release. Isothermal and humidity aging did not appear to alter the fiber release tendencies.

House, E. E.; Hoggatt, J. T.; Symonds, W. A.

1980-01-01

107

Glass-matrix biocomposites.  

PubMed

CaO-SiO(2) base glass-matrix/Ti particle biocomposite coatings on Ti6Al4V substrates have been prepared by means of Vacuum Plasma Spray. The base glass is considered bioactive, because, when soaked in a fluid that simulates the inorganic ion concentration of human plasma (SBF), it develops a bonelike apatite layer on its surface. The aim of this research activity was to toughen this brittle bioactive material and to broaden its biomedical applications. Pure titanium was chosen as toughening phase because of its well-known biocompatibility, and Ti6Al4V alloy as substrate because of both its biocompatibility and its mechanical reliability. At first the composites were prepared as bulk materials, by means of a simple sintering process. Then, by ball-milling the sintered composite, the as-obtained "composite powders" were sprayed by Vacuum Plasma Spray (VPS) on the substrate. By means of Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC), the characteristic temperatures of the base glasses were determined. The thermal properties of mixtures of glass powders and different vol% Ti particles were studied by means of DTA, DSC, hot-stage microscopy, and dilatometry, with the aim of optimizing the sintering conditions. Both the bulk and the coated samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), compositional analysis (EDS), Vickers indentations, and leaching tests after soaking in a simulated body fluid (SBF). PMID:10898882

Verné, E; Brovarone, C V; Milanese, D

2000-01-01

108

Matrix metalloproteinases in atherothrombosis.  

PubMed

The metalloproteinases (MMPs, matrixins) are zinc-containing endopeptidases involved in the metabolism of extracellular matrix as well as in the cleavage of other proteins. The MMP family currently consists of 28 enzymes with somewhat different activities. The members are in part categorized into groups according to either structure or preferred substrates and referred to as collagenases, gelatinases, stromelysins, matrilysins, and membrane-bound MMPs. The proteinase activities exerted by 11 of the 28 MMPs have been implicated in some of the biologic processes associated with atherosclerosis and its ischemic clinical manifestations such as myocardial infarction and stroke. For example, several of the MMPs are locally expressed within human atherosclerotic lesions. However, association studies of subclinical atherosclerosis have generated contradictory results in the role of MMP activities. In addition, circulating MMP levels as well as genetic variations within the genes encoding the different enzymes have been associated with both an increased and decreased cardiovascular risk. Finally, experimental studies of hyperlipemic mice and vascular injury have suggested some of the MMPs function as modulators of atherogenesis, vascular remodeling, and plaque rupture. PMID:20226959

Bäck, Magnus; Ketelhuth, Daniel F J; Agewall, Stefan

2010-01-01

109

Matrix Treatment of Ray Optics.  

ERIC Educational Resources Information Center

Describes a method to combine two learning experiences--optical physics and matrix mathematics--in a straightforward laboratory experiment that allows engineering/physics students to integrate a variety of learning insights and technical skills, including using lasers, studying refraction through thin lenses, applying concepts of matrix

Quon, W. Steve

1996-01-01

110

Nonnegative matrix factorization with -divergence  

E-print Network

and S RnÃ?N is the associated encoding variable matrix. Both matrices A and S are restricted to have only A and encoding variable matrix S with both A and S allowed to have only nonnegative elements. In this paper we

Cichocki, Andrzej

111

Synthetic Division and Matrix Factorization  

ERIC Educational Resources Information Center

Synthetic division is viewed as a change of basis for polynomials written under the Newton form. Then, the transition matrices obtained from a sequence of changes of basis are used to factorize the inverse of a bidiagonal matrix or a block bidiagonal matrix.

Barabe, Samuel; Dubeau, Franc

2007-01-01

112

How to Study a Matrix  

ERIC Educational Resources Information Center

This study investigated how best to study a matrix. Fifty-three participants studied a matrix topically (1 column at a time), categorically (1 row at a time), or in a unified way (all at once). Results revealed that categorical and unified study produced higher: (a) performance on relationship and fact tests, (b) study material satisfaction, and…

Jairam, Dharmananda; Kiewra, Kenneth A.; Kauffman, Douglas F.; Zhao, Ruomeng

2012-01-01

113

Developments in random matrix theory  

Microsoft Academic Search

In this introduction to the Journal of Physics A special issue on random matrix theory, we give a review of the main historical developments in random matrix theory. A short summary of the papers that appear in this special issue is also given.

P J Forrester; N C Snaith; J. J. M. Verbaarschot

2003-01-01

114

New pole placement algorithm - Polynomial matrix approach  

NASA Technical Reports Server (NTRS)

A simple and direct pole-placement algorithm is introduced for dynamical systems having a block companion matrix A. The algorithm utilizes well-established properties of matrix polynomials. Pole placement is achieved by appropriately assigning coefficient matrices of the corresponding matrix polynomial. This involves only matrix additions and multiplications without requiring matrix inversion. A numerical example is given for the purpose of illustration.

Shafai, B.; Keel, L. H.

1990-01-01

115

L20: Sparse Matrix Algorithms, SIMD review!  

E-print Network

: Sparse input matrices which were generated from the MatrixMarket (see http://math.nist.gov/MatrixL20: Sparse Matrix Algorithms, SIMD review! November 15, 2012! #12;Administrative ·CUDA Project 5 The code in sparse_matvec.c is a sequential version of a sparse matrix-vector multiply. The matrix

Hall, Mary W.

116

The matrix of inspiration  

NASA Astrophysics Data System (ADS)

The research of Odile Meulien and Dietmar Ohlmann is about perceiving a multidimensional world. Not about the cyberspace created for new cinema creation, nor the reality which seems to be created by communication. It's the search for the reality we perceive, when the mind "touches" an object with its senses. In fact, it is a study of the surface of an object, which we can record in its visual appearing, its structure, shape and colors. When using photographic media, the tactile sense of the structure is missing, when using some other reproductive media; we experience somewhere a sensation of fault, something different. When using holography, we are able to record some three dimensional shape which has in fact a lot of parameter of a realistic copy. What is missing is the touch, the smell, the way we can go close and far, surround the object, relate the reflected light to its surrounding. The only interesting attribute of a hologram is for Dietmar Ohlmann its capacity to illustrate a continuum. He likes its changing diffractive character during daytime and surrounds lighting. For Odile Meulien the continuum of a hologram represents a new possible model for understanding wholeness in a social context. In fact, both are working on an educational process together, helping children and adults to find a new position of their own in harmony with living surrounding. Dietmar Ohlmann is working on his artistic side, while Odile Meulien works on educational programs experiencing the perspective of a curator and social analyst. New is the implication of using the latest of the techniques like the atomic force microscopy, which make possible to touch the holographic grating while the holographic image remains untouched. In other words it is the reverse of the usual approach of objects which at first we touch to investigate further. Their difference in experiencing and perceiving scientific and technical approach brings a lot of paradigm in their discussion. Together they will perform this exchange, as a matrix, understood as source, of new ideas.

Oehlmann, Dietmar; Ohlmann, Odile M.; Danzebrink, Hans U.

2005-04-01

117

A q-Matrix Encoding Extending the Parikh Matrix Mapping  

Microsoft Academic Search

We introduce a generalization of the Parikh mapping called the Parikh q-matrix encoding, which takes its values in matrices with polynomial entries. The encoding represents a word w over a k-letter alphabet as a (k +1 )-dimensional upper-triangular matrix with entries that are nonnegative integral polynomials in variable q. Putting q =1 , we obtain the morphism introduced by Mateescu,

Ömer Eù

118

Meaning of the Density Matrix  

E-print Network

Protective measurement, which was proposed as a method of observing the wavefunction of a single system, is extended to the observation of the density matrix of a single system. d'Espagnat's definition of `proper mixture' is shown to be improper because it does not allow for appropriate fluctuations. His claim that there could be different mixtures corresponding to the same density matrix is critically examined. These results provide a new meaning to the density matrix, which gives it the same ontological status as the wavefunction describing a pure state. This also enables quantum entropy to be associated with a single system.

Y. Aharonov; J. Anandan

1998-03-08

119

Genotype imputation via matrix completion  

PubMed Central

Most current genotype imputation methods are model-based and computationally intensive, taking days to impute one chromosome pair on 1000 people. We describe an efficient genotype imputation method based on matrix completion. Our matrix completion method is implemented in MATLAB and tested on real data from HapMap 3, simulated pedigree data, and simulated low-coverage sequencing data derived from the 1000 Genomes Project. Compared with leading imputation programs, the matrix completion algorithm embodied in our program MENDEL-IMPUTE achieves comparable imputation accuracy while reducing run times significantly. Implementation in a lower-level language such as Fortran or C is apt to further improve computational efficiency. PMID:23233546

Chi, Eric C.; Zhou, Hua; Chen, Gary K.; Del Vecchyo, Diego Ortega; Lange, Kenneth

2013-01-01

120

Molybdenum disilicide alloy matrix composite  

DOEpatents

Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.

Petrovic, John J. (Los Alamos, NM); Honnell, Richard E. (Los Alamos, NM); Gibbs, W. Scott (Los Alamos, NM)

1991-01-01

121

Molybdenum disilicide alloy matrix composite  

DOEpatents

Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions are disclosed. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms. 3 figures.

Petrovic, J.J.; Honnell, R.E.; Gibbs, W.S.

1991-12-03

122

Molybdenum disilicide alloy matrix composite  

DOEpatents

Compositions of matter consisting of matrix matrials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.

Petrovic, John J. (Los Alamos, NM); Honnell, Richard E. (Los Alamos, NM); Gibbs, W. Scott (Los Alamos, NM)

1990-01-01

123

The Extracellular Matrix: An Overview  

Microsoft Academic Search

\\u000a The extracellular matrix encompasses the very large number of constituent macromolecules that are synthesized and secreted\\u000a by cells into the space surrounding them, followed in most cases by further assembly, cross-linking, and\\/or polymerization\\u000a of the secreted proteins to form an organized structure. The extracellular matrix has a number of critical roles in tissue\\u000a and organ development, function, and repair after

Jeffrey H. Miner

124

Learning with Matrix Factorizations Nathan Srebro  

E-print Network

Learning with Matrix Factorizations by Nathan Srebro Submitted to the Department of Electrical;Learning with Matrix Factorizations by Nathan Srebro Submitted to the Department of Electrical Engineering

Qiu, Robert Caiming

125

The Astrobiology Matrix and the "Drake Matrix" in Education  

NASA Technical Reports Server (NTRS)

We organized astrobiology lectures in the Eotvos Lorand University of Sciences and the Polaris Observatory in 2002. We present here the "Drake matrix" for the comparison of the astrobiological potential of different bodies [1], and astrobiology matrix for the visualization of the interdisciplinary connections between different fields of astrobiology. Conclusion: In Hungary it is difficult to integrate astrobiology in the education system but the great advantage is that it can connect different scientific fields and improve the view of students. We would like to get in contact with persons and organizations who already have experience in the education of astrobiology.

Mizser, A.; Kereszturi, A.

2003-01-01

126

Matrix Formalism of Synchrobetatron Coupling  

SciTech Connect

In this paper we present a complete linear synchrobetatron coupling formalism by studying the transfer matrix which describes linear horizontal and longitudinal motions. With the technique established in the linear horizontal-vertical coupling study [D. Sagan and D. Rubin, Phys. Rev. ST Accel. Beams 2, 074001 (1999)], we found a transformation to block diagonalize the transfer matrix and decouple the betatron motion and the synchrotron motion. By separating the usual dispersion term from the horizontal coordinate first, we were able to obtain analytic expressions of the transformation under reasonable approximations. We also obtained the perturbations to the betatron tune and the Courant-Snyder functions. The closed orbit changes due to finite energy gains at rf cavities and radiation energy losses were also studied by the 5 x 5 extended transfer matrix with the fifth column describing kicks in the 4-dimension phase space.

Huang, Xiaobiao; /SLAC

2006-10-06

127

Propagation of Errors for Matrix Inversion  

E-print Network

A formula is given for the propagation of errors during matrix inversion. An explicit calculation for a 2 by 2 matrix using both the formula and a Monte Carlo calculation are compared. A prescription is given to determine when a matrix with uncertain elements is sufficiently nonsingular for the calculation of the covariances of the inverted matrix elements to be reliable.

M. Lefebvre; R. K. Keeler; R. Sobie; J. White

1999-09-17

128

Algebraic Approach to Bare Nucleon Matrix Elements  

E-print Network

An algebraic method for evaluating bare nucleon matrix elements of quark operators is proposed. Thereby, bare nucleon matrix elements are traced back to vacuum matrix elements. The method is similar to the soft pion theorem. Matrix elements of two-quark, four-quark and six-quark operators inside the bare nucleon are considered.

Sven Zschocke; Burkhard Kampfer; Guenter Plunien

2005-06-29

129

Responsbility Matrix Data, Communications, Security  

E-print Network

Responsbility Matrix Data, Communications, Security New Construction only SYSTEM SUPPLY INSTALL, Communications, Security New Construction only SYSTEM SUPPLY INSTALL TERMINATE TEST Cost Est. Backbone (Copper above See data system above Network Video Recorder Dal CS Dal AC n/a n/a Dal CS&AC Cameras Elect Elect

Brownstone, Rob

130

System identification using transfer matrix  

Microsoft Academic Search

A new approach is proposed for multivariable system identification in the deterministic model framework. In the proposed approach, MIMO system is represented using transfer function (TF) matrix whose elements are the standard, fixed structure TFs like FOPDT, SOPDT etc. These model structures are capable of approximating well a very large class of systems found in practice. The system identification problem

Jayesh J. Barve; V. S. S. Rameshkumar Junnuri

2004-01-01

131

Matrix metalloproteinases and oral cancer  

Microsoft Academic Search

For tumours to invade and metastasise, neoplastic cells must be capable of degrading the extracellular matrix (ECM), and accessing blood vessels and lymphatics. This process is mediated in the pericellular environment and is a highly controlled cascade of events utilising the same mechanisms that normal cells use for migrating through tissue barriers, for example, in development and wound healing. Proteolytic

G. T Thomas; M. P Lewis; P. M Speight

1999-01-01

132

Supersymmetry in Random Matrix Theory  

E-print Network

Supersymmetry is nowadays indispensable for many problems in Random Matrix Theory. It is presented here with an emphasis on conceptual and structural issues. An introduction to supermathematics is given. The Hubbard-Stratonovich transformation as well as its generalization and superbosonization are explained. The supersymmetric non-linear sigma model, Brownian motion in superspace and the color-flavor transformation are discussed.

Thomas Guhr

2010-05-06

133

Switching Matrix For Optical Signals  

NASA Technical Reports Server (NTRS)

Proposed matrix of electronically controlled shutters switches signals in optical fibers between multiple input and output channels. Size, weight, and power consumption reduced. Device serves as building block for small, low-power, broad-band television- and data-signal-switching systems providing high isolation between nominally disconnected channels.

Grove, Charles H.

1990-01-01

134

Matrix Completion from Noisy Entries  

Microsoft Academic Search

Given a matrix M of low-rank, we consider the problem of reconstructing it from noisy observations of a small, random subset of its entries. The problem arises in a variety of applications, from collaborative filtering ( the 'Netflix problem') to structure-from-motion and positioning. We study a low complexity algorithm introduced in (1), based on a combination of spectral techniques and

Raghunandan H. Keshavan; Andrea Montanari; Sewoong Oh

2009-01-01

135

Recoupling matrix elements and decay  

E-print Network

Recoupling matrix elements are evaluated, in the harmonic oscillator approximation, for all possible angular and radial excitations in processes where quarks recombine. A diagrammatic representation is given. Their use is demonstrated in calculating the transition potential for rho to two pions in a pair creation model.

Eef van Beveren

2006-02-28

136

Matrix Multiplication on Heterogeneous Platforms  

Microsoft Academic Search

In this paper, we address the issue of implementing matrix multiplication on heterogeneous platforms. We target two different classes of heterogeneous computing resources: heterogeneous networks of workstations and collections of heterogeneous clusters. Intuitively, the problem is to load balance the work with different speed resources while minimizing the communication volume. We formally state this problem in a geometric framework and

Olivier Beaumont; Vincent Boudet; Fabrice Rastello; Yves Robert

2001-01-01

137

Integrability and generalized monodromy matrix  

SciTech Connect

We construct the generalized monodromy matrix M-circumflex({omega}) of two-dimensional string effective action by introducing the T-duality group properties. The integrability conditions with general solutions depending on spectral parameter are given. This construction is investigated for the exactly solvable Wess, Zumino, Novikov, and Witten model in pp-wave limit when B=0.

Lhallabi, T.; Moujib, A. [Lab/UFR--Physique des Hautes Energies, Faculte des Sciences, Rabat (Morocco); Groupement National de Physique des Hautes Energies, Siege focal, Faculte des Sciences de Rabat, Rabat (Morocco); Virtual African Centre for Basic Science and Technology, Focal point, LabUFR-PHE, Rabat (Morocco)

2007-09-15

138

STRATIFICATION OF MATRIX PENCILS IN  

E-print Network

. Erik Elmroth, Pedher Johansson, Stefan Johansson, and Bo K°agstr¨om. Orbit and bundle stratificationSTRATIFICATION OF MATRIX PENCILS IN SYSTEMS AND CONTROL: THEORY AND ALGORITHMS Stefan Johansson x Stefan Johansson Licentiate Thesis, May 2005 UMINF-05.17 Department of Computing Science Ume°a University

Johansson, Stefan

139

The Simplest Neutrino Mass Matrix  

E-print Network

We motivate the simplest ansatz for the neutrino mass matrix consistent with the data from neutrino oscillation experiments, and admitting CP violation. It has only two free parameters: an arbitrary mass-scale and a small dimensionless ratio. This mass matrix exhibits two symmetries, Democracy and Mutativity, which respectively ensure trimaximal mixing of the |nu_2> mass eigenstate, and mixing parameter values |theta_{23}|=45 degrees and |delta|=90 degrees, consistent with bimaximal mixing of the |nu_3> mass eigenstate. A third constraint relates the smallness of |U_{e3}|^2 to that of the mass-squared difference ratio, Delta m^2_sol/Delta m^2_atm, yielding the prediction sin(theta_{13})=sqrt{2 Delta m^2_sol/3 Delta m^2_atm} ~ 0.13 +- 0.03.

P. F. Harrison; W. G. Scott

2004-03-29

140

Sapphire reinforced alumina matrix composites  

NASA Technical Reports Server (NTRS)

Unidirectionally reinforced A1203 matrix composites have been fabricated by hot pressing. Approximately 30 volume % of either coated or uncoated sapphire fiber was used as reinforcement. Unstabilized ZrO2 was applied as the fiber coating. Composite mechanical behavior was analyzed both after fabrication and after additional heat treatment. The results of composite tensile tests were correlated with fiber-matrix interfacial shear strengths determined from fiber push-out tests. Substantially higher strength and greater fiber pull-out were observed for the coated fiber composites for all processing conditions studied. The coated fiber composites retained up to 95% and 87% of their as-fabricated strength when heat treated at 14000C for 8 or 24 hours, respectively. Electron microscopy analysis of the fracture surfaces revealed extensive fiber pull-out both before and after heat treatment.

Jaskowiak, Martha H.; Setlock, John A.

1994-01-01

141

Matrix Pencils and Entanglement Classification  

E-print Network

In this paper, we study pure state entanglement in systems of dimension $2\\otimes m\\otimes n$. Two states are considered equivalent if they can be reversibly converted from one to the other with a nonzero probability using only local quantum resources and classical communication (SLOCC). We introduce a connection between entanglement manipulations in these systems and the well-studied theory of matrix pencils. All previous attempts to study general SLOCC equivalence in such systems have relied on somewhat contrived techniques which fail to reveal the elegant structure of the problem that can be seen from the matrix pencil approach. Based on this method, we report the first polynomial-time algorithm for deciding when two $2\\otimes m\\otimes n$ states are SLOCC equivalent. Besides recovering the previously known 26 distinct SLOCC equivalence classes in $2\\otimes 3\\otimes n$ systems, we also determine the hierarchy between these classes.

Eric Chitambar; Carl A. Miller; Yaoyun Shi

2009-11-09

142

Corrosion of Titanium Matrix Composites  

SciTech Connect

The corrosion behavior of unalloyed Ti and titanium matrix composites containing up to 20 vol% of TiC or TiB{sub 2} was determined in deaerated 2 wt% HCl at 50, 70, and 90 degrees C. Corrosion rates were calculated from corrosion currents determined by extrapolation of the tafel slopes. All curves exhibited active-passive behavior but no transpassive region. Corrosion rates for Ti + TiC composites were similar to those for unalloyed Ti except at 90 degrees C where the composites were slightly higher. Corrosion rates for Ti + TiB{sub 2} composites were generally higher than those for unalloyed Ti and increased with higher concentrations of TiB{sub 2}. XRD and SEM-EDS analyses showed that the TiC reinforcement did not react with the Ti matrix during fabrication while the TiB{sub 2} reacted to form a TiB phase.

Covino, B.S., Jr.; Alman, D.E.

2002-09-22

143

Extracellular Matrix Production by Osteoblasts  

NASA Technical Reports Server (NTRS)

In this graduate course lecture, the basic biology of osteoblasts will be explored. Cells of the osteoblast lineage arise from the mesoderm and neural crest, showing remarkable plasticity with respect to differentiation. Basic mechanisms involved in the proliferation, differentiation, and survival of osteoblasts will be described. The extracellular matrix (ECM) is known to be both thc main product of the mature osteoblast, and an effective regulator of osteoblast function. The impact of these interactions on skeletal biology will be discussed.

Globus, Ruth

2003-01-01

144

Melanoma Multiple Primary Rules Matrix  

Cancer.gov

Cutaneous Melanoma Multiple Primary Rules – Matrix C440 – C449 (Excludes melanoma of any other site) * P r e p ar e o n e abs tr a c t. U s e t h e hi s t o lo g y c o di ng r u le s t o as s i gn th e ap pr o p r iat e h is to lo

145

Kidney Multiple Primary Rules Matrix  

Cancer.gov

Kidney Multiple Primary Rules – Matrix C649 (Excludes lymphoma and leukemia M9590 – 9989 and Kaposi sarcoma M9140) * P r e p ar e o n e abs tr a c t. U s e t h e hi s t o lo g y c o di ng r u le s t o as s i gn th e ap pr o p r iat

146

Colon Multiple Primary Rules Matrix  

Cancer.gov

Colon Multiple Primary Rules – Matrix C180-C189 (Excludes lymphoma and leukemia M9590 – 9989 and Kaposi sarcoma M9140) * P r e p ar e o n e abs tr a c t. U s e t h e hi s t o lo g y c o di ng r u le s t o as s i gn th e ap pr o p

147

Tough high performance composite matrix  

NASA Technical Reports Server (NTRS)

This invention is a semi-interpentrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide. Provided is an improved high temperature matrix resin which is capable of performing in the 200 to 300 C range. This resin has significantly improved toughness and microcracking resistance, excellent processability, mechanical performance, and moisture and solvent resistances.

Pater, Ruth H. (inventor); Johnston, Norman J. (inventor)

1994-01-01

148

A combinatorial extracellular matrix platform identifies cell-extracellular matrix interactions that correlate with metastasis  

E-print Network

Extracellular matrix interactions have essential roles in normal physiology and many pathological processes. Although the importance of extracellular matrix interactions in metastasis is well documented, systematic approaches ...

Reticker-Flynn, Nathan E.

149

Diabetic Nephropathy and Extracellular Matrix  

PubMed Central

Diabetic nephropathy (DN) is a serious complication in diabetes. Major typical morphological changes are the result of changes in the extracellular matrix (ECM). Thus, basement membranes are thickened and the glomerular mesangial matrix and the tubulointerstitial space are expanded, due to increased amounts of ECM. One important ECM component, the proteoglycans (PGs), shows a more complex pattern of changes in DN. PGs in basement membranes are decreased but increased in the mesangium and the tubulointerstitial space. The amounts and structures of heparan sulfate chains are changed, and such changes affect levels of growth factors regulating cell proliferation and ECM synthesis, with cell attachment affecting endothelial cells and podocytes. Enzymes modulating heparan sulfate structures, such as heparanase and sulfatases, are implicated in DN. Other enzyme classes also modulate ECM proteins and PGs, such as matrix metalloproteinases (MMPs) and serine proteases, such as plasminogen activator, as well as their corresponding inhibitors. The levels of these enzymes and inhibitors are changed in plasma and in the kidneys in DN. Several growth factors, signaling pathways, and hyperglycemia per se affect ECM synthesis and turnover in DN. Whether ECM components can be used as markers for early kidney changes is an important research topic, whereas at present, the clinical use remains to be established. PMID:23103723

Reinholt, F. P.; Jenssen, T.

2012-01-01

150

Nuclear matrix elements for double beta decay  

E-print Network

The present status of calculations of the nuclear matrix elements for neutrinoless double beta decay is reviewed. A proposal which allows in principle to measure the neutrinoless double beta decay Fermi matrix element is briefly described.

Vadim Rodin

2009-10-30

151

Fast polar decomposition of an arbitrary matrix  

NASA Technical Reports Server (NTRS)

The polar decomposition of an m x n matrix A of full rank, where m is greater than or equal to n, can be computed using a quadratically convergent algorithm. The algorithm is based on a Newton iteration involving a matrix inverse. With the use of a preliminary complete orthogonal decomposition the algorithm can be extended to arbitrary A. How to use the algorithm to compute the positive semi-definite square root of a Hermitian positive semi-definite matrix is described. A hybrid algorithm which adaptively switches from the matrix inversion based iteration to a matrix multiplication based iteration due to Kovarik, and to Bjorck and Bowie is formulated. The decision when to switch is made using a condition estimator. This matrix multiplication rich algorithm is shown to be more efficient on machines for which matrix multiplication can be executed 1.5 times faster than matrix inversion.

Higham, Nicholas J.; Schreiber, Robert S.

1988-01-01

152

Mechanical hysteresis in ceramic matrix composites  

Microsoft Academic Search

Ceramic matrix composites (CMCs) are interesting materials for aeronautic applications because of their good mechanical properties at high temperatures even under air. Contrary to bulk ceramics, CMCs have a non-brittle mechanical behaviour due to the high strength of fibres, and due to optimized fibre\\/matrix interactions after matrix multi-cracking.Interactions between fibres and matrix act mainly at the interface level. When fibres

G. Fantozzi; P. Reynaud

2009-01-01

153

The Concept of Matrix: A Metaphysical Enquiry  

Microsoft Academic Search

Trying to find the right title for a paper on the matrix I had recently begun writing, suddenly it seemed of the essence to decide whether to refer to `the matrix' or `matrix'. Why this should make all the difference I could not at first understand. By the end of the paper I felt sure that this was not a

Andrew Powell

1992-01-01

154

Nuclear matrix proteins and hereditary diseases  

Microsoft Academic Search

The review summarizes literature data on alterations of structure or expression of different nuclear matrix proteins in hereditary syndromes. From the point of view of involvement of nuclear matrix proteins in etiology and pathogenesis of the disease, hereditary pathologies can be classified in pathologies with pathogenesis associated with defects of nuclear matrix proteins and pathologies associated to changes of the

N. Sjakste; T. Sjakste

2005-01-01

155

On analytical solutions of matrix Riccati equations  

Microsoft Academic Search

Matrix Riccati equations appear in numerous applications, especially in control engineering. In this paper we derive analytical\\u000a formulas for exact solutions of algebraic and differential matrix Riccati equations. These solutions are expressed in terms\\u000a of matrix transfer functions of appropriate linear dynamical systems.

Yuri S. Ledyaev

2011-01-01

156

Rank Test Based On Matrix Perturbation Theory  

Microsoft Academic Search

In this paper, we propose methods of the determination of the rank of matrix. We consider a rank test for an unobserved matrix for which an estimate exists having normal asymptotic distribution of order N1\\/2 where N is the sample size. The test statistic is based on the smallest estimated singular values. Using Matrix Perturbation Theory, the smallest singular values

Zaka Ratsimalahelo

2001-01-01

157

Multiple roles of matrix metalloproteinases during apoptosis  

Microsoft Academic Search

Structural, molecular and biochemical approaches have contributed to piecing together the puzzle of how matrix metalloproteinases (MMPs) work and contribute to various disease processes. However, MMPs have many unexpected substrates other than components of the extracellular matrix which profoundly influence cell behaviour, survival and death. With the current understanding of diverse\\/novel roles of matrix metalloproteinases—particularly their direct or indirect relevance

F. Mannello; F. Luchetti; E. Falcieri; S. Papa

2005-01-01

158

Aluminum matrix composites and their superplasticity  

SciTech Connect

This paper introduces in simple terms manufacturing methods associated with aluminum matrix composite materials, superplasticity research as well as its applications, and probes structural faults during the manufacturing of aluminum matrix composite materials. In conjunction with this, it brings together a crossing of subjects to expound on trends in the development of research on aluminum matrix composite material superplasticity and its applications.

Tang, C.; Li, S.; Li, H.

1995-05-26

159

Metal-matrix composites: Status and prospects  

NASA Technical Reports Server (NTRS)

Applications of metal matrix composites for air frames and jet engine components are discussed. The current state of the art in primary and secondary fabrication is presented. The present and projected costs were analyzed to determine the cost effectiveness of metal matrix composites. The various types of metal matrix composites and their characteristics are described.

1974-01-01

160

Random Matrix Theory and its Innovative Applications  

E-print Network

deep in the heart of nature." 1. Distinguishing "signal" from "noise": Generate a matrix of dataRandom Matrix Theory and its Innovative Applications Alan Edelman and Yuyang Wang Abstract Recently more and more disciplines of science and engineering have found Random Matrix Theory valuable. Some

Edelman, Alan

161

Combinatorial Optimization of Matrix-Vector Multiplication  

E-print Network

/21/2007 #12;2 Optimization Problem Objective: Generate set of operations for computing matrix-vector product;24 Graph Model Example - Instructions Generated Matrix (16 nz) MST traversal Instructions (9 MAPs) #121 Combinatorial Optimization of Matrix-Vector Multiplication Michael Wolf University of Illinois 6

Wolf, Michael M.

162

THE MATRIX CUBE PROBLEM: Approximations and Applications  

E-print Network

THE MATRIX CUBE PROBLEM: Approximations and Applications Arkadi Nemirovski, Stieltjes Visiting with A. Ben-Tal 1. Matrix Cube � The problem: formulation and moti- vation � Main result � Back to applications � Sketch of the proof 2. From Matrix Cube to Computing Ma- trix Norms � The problem � Main result

Nemirovski, Arkadi

163

Teaching Tip: When a Matrix and Its Inverse Are Stochastic  

ERIC Educational Resources Information Center

A stochastic matrix is a square matrix with nonnegative entries and row sums 1. The simplest example is a permutation matrix, whose rows permute the rows of an identity matrix. A permutation matrix and its inverse are both stochastic. We prove the converse, that is, if a matrix and its inverse are both stochastic, then it is a permutation matrix.

Ding, J.; Rhee, N. H.

2013-01-01

164

Nuclear localization of matrix metalloproteinases.  

PubMed

Matrix metalloproteinases (MMPs) were originally identified as matrixin proteases that act in the extracellular matrix. Recent works have uncovered nontraditional roles for MMPs in the extracellular space as well as in the cytosol and nucleus. There is strong evidence that subspecialized and compartmentalized matrixins participate in many physiological and pathological cellular processes, in which they can act as both degradative and regulatory proteases. In this review, we discuss the transcriptional and translational control of matrixin expression, their regulation of intracellular sorting, and the structural basis of activation and inhibition. In particular, we highlight the emerging roles of various matrixin forms in diseases. The activity of matrix metalloproteinases is regulated at several levels, including enzyme activation, inhibition, complex formation and compartmentalization. Most MMPs are secreted and have their function in the extracellular environment. MMPs are also found inside cells, both in the nucleus, cytosol and organelles. The role of intracellular located MMPs is still poorly understood, although recent studies have unraveled some of their functions. The localization, activation and activity of MMPs are regulated by their interactions with other proteins, proteoglycan core proteins and / or their glycosaminoglycan chains, as well as other molecules. Complexes formed between MMPs and various molecules may also include interactions with noncatalytic sites. Such exosites are regions involved in substrate processing, localized outside the active site, and are potential binding sites of specific MMP inhibitors. Knowledge about regulation of MMP activity is essential for understanding various physiological processes and pathogenesis of diseases, as well as for the development of new MMP targeting drugs. PMID:22226510

Mannello, Ferdinando; Medda, Virginia

2012-03-01

165

Glycosaminoglycans content of stone matrix.  

PubMed

The role of urinary glycosaminoglycans (GAGs) in lithogenesis is a topic of current interest in urologic research. One GAG, chondroitin sulfate, has previously been shown to inhibit calcium oxalate crystal formation. It has long been known that the chemical components of GAGs are present in the matrix of urinary concretions, but it has not been determined whether these components exist in free form or as constituents of GAG. This study was undertaken to determine whether GAGs are present in urinary stone matrices and, if so, to characterize them. Matrices of nine single urinary stones of various compositions and of three stone pools (calcium oxalate, magnesium ammonium phosphate) were isolated by exhaustive dialysis. The techniques of cellulose acetate electrophoresis, Alcian blue staining and enzymatic degradation were used to identify various GAGs. Material that stained Alcain blue was present in eleven of twelve samples. GAG was detected as this material in ten samples. The GAGs identified are heparan sulfate, hyaluronic acid and possibly keratan sulfate. The most prominent urinary GAG, chondroitin sulfate, was notably absent from urinary stone matrix. GAG seems to be incorporated into matrix on a selective basis. This finding may be due to differences in the affinities of different GAG species for the crystals which comprise the calculi. It has been proposed that the inhibitory activity of GAGs lies in their ability to bind to (and therefore block) the growth sites of crystals. It is apparent from this study that certain GAG species are incorporated into the structure of the stone and they may be intimately related to stone development and growth. PMID:3959234

Roberts, S D; Resnick, M I

1986-05-01

166

The effect of the matrix on film properties in matrix-assisted pulsed laser evaporation  

E-print Network

The effect of the matrix on film properties in matrix-assisted pulsed laser evaporation D. M. Bubba amu have been deposited by matrix-assisted pulsed laser evaporation MAPLE . The deposition was carried as a matrix. Time-of-flight analysis was performed using a quadrupole mass spectrometer to monitor evaporation

Vertes, Akos

167

Simplicial matrix-tree theorems  

E-print Network

F is the facet of ? corresponding to that column. Let ˆ? k be the product of the nonzero eigenvalues of ˆ L ud ?,k?1 ,andlet ˆ? k =ˆ? k (?) = summationdisplay ??T k (?) | ˜ H k?1 (?)| 2 X ? . Theorem 1.4 (Weighted Simplicial Matrix-Tree Theorem). Let ? be a d... are explained in more detail in Section 8.4. Its spanning trees are enumerated in Examples 9.1 (fine weighting) and 9.3 (coarse weighting). We prove Theorem 1.5 by exploiting the recursive structure of shifted complexes. As in [13], we begin by calculating...

Duval, Art M.; Klivans, Caroline J.; Martin, Jeremy L.

2009-01-01

168

Regenerator matrix physical property data  

NASA Technical Reports Server (NTRS)

Among several cellular ceramic structures manufactured by various suppliers for regenerator application in a gas turbine engine, three have the best potential for achieving durability and performance objectives for use in gas turbines, Stirling engines, and waste heat recovery systems: (1) an aluminum-silicate sinusoidal flow passage made from a corrugated wate paper process; (2) an extruded isosceles triangle flow passage; and (3) a second generation matrix incorporating a square flow passage formed by an embossing process. Key physical and thermal property data for these configurations presented include: heat transfer and pressure drop characteristics, compressive strength, tensile strength and elasticity, thermal expansion characteristics, chanical attack, and thermal stability.

Fucinari, C. A.

1980-01-01

169

Fiber-matrix interface failures  

NASA Technical Reports Server (NTRS)

Interface fractures of aluminum-graphite composites under transverse loading are expected to occur within the graphite fibers, but very near the interface. Residual stresses in aluminum, reinforced with the new high modulus pitch-based fibers, are much lower than would be expected based on simple elasticity calculations. The excess stress may be relaxed by shearing internal to the fibers or at the interface rather than by plastic flow of the matrix. The internal shearing also occurs during repeated thermal cycling of these composites; the fibers are repeatedly intruded, then extruded, during repeated temperature excursions.

Rabenberg, Lew; Marcus, Harris L.; Park, Hun Sub; Zong, Gui Sheng; Brown, Lloyd D.

1989-01-01

170

Ideals of generalized matrix rings  

SciTech Connect

Let R and S be rings, and {sub R}M{sub S} and {sub S}N{sub R} bimodules. In the paper, in terms of isomorphisms of lattices, relationships between the lattices of one-sided and two-sided ideals of the generalized matrix ring and the corresponding lattices of ideals of the rings R and S are described. Necessary and sufficient conditions for a pair of ideals I, J of rings R and S, respectively, to be the main diagonal of some ideal of the ring K are also obtained. Bibliography: 8 titles.

Budanov, Aleksandr V [Tomsk State University, Tomsk (Russian Federation)

2011-01-31

171

Error analysis for Mueller matrix measurement.  

PubMed

The linear errors of Mueller matrix measurements are formulated for misalignment, depolarization, and incorrect retardation of the polarimetric components. The measured errors of a Mueller matrix depend not only on the imperfections of the measuring system but also on the Mueller matrix itself. The error matrices for different polarimetric systems are derived and also evaluated for the straight-through case. The error matrix for a polarizer-sample-analyzer system is much simpler than those for more complicated systems. The general error matrix is applied to null ellipsometry, and the obtained errors in ellipsometric parameters psi and delta are identical to the errors specifically derived for null ellipsometry with depolarization. PMID:12938923

Nee, Soe-Mie F

2003-08-01

172

Uniform-burning matrix burner  

DOEpatents

Computer simulation was used in the development of an inward-burning, radial matrix gas burner and heat pipe heat exchanger. The burner and exchanger can be used to heat a Stirling engine on cloudy days when a solar dish, the normal source of heat, cannot be used. Geometrical requirements of the application forced the use of the inward burning approach, which presents difficulty in achieving a good flow distribution and air/fuel mixing. The present invention solved the problem by providing a plenum with just the right properties, which include good flow distribution and good air/fuel mixing with minimum residence time. CFD simulations were also used to help design the primary heat exchanger needed for this application which includes a plurality of pins emanating from the heat pipe. The system uses multiple inlet ports, an extended distance from the fuel inlet to the burner matrix, flow divider vanes, and a ring-shaped, porous grid to obtain a high-temperature uniform-heat radial burner. Ideal applications include dish/Stirling engines, steam reforming of hydrocarbons, glass working, and any process requiring high temperature heating of the outside surface of a cylindrical surface.

Bohn, Mark S. (Golden, CO); Anselmo, Mark (Arvada, CO)

2001-01-01

173

Characterization of Metal Matrix Composites  

NASA Technical Reports Server (NTRS)

Experimental methods were developed, adapted, and applied to the characterization of a metal matrix composite system, namely, silicon carbide/aluminim (SCS-2/6061 Al), and its constituents. The silicon carbide fiber was characterized by determining its modulus, strength, and coefficient of thermal expansion. The aluminum matrix was characterized thermomechanically up to 399 C (750 F) at two strain rates. The unidirectional SiC/Al composite was characterized mechanically under longitudinal, transverse, and in-plane shear loading up to 399 C (750 F). Isothermal and non-isothermal creep behavior was also measured. The applicability of a proposed set of multifactor thermoviscoplastic nonlinear constitutive relations and a computer code was investigated. Agreement between predictions and experimental results was shown in a few cases. The elastoplastic thermomechanical behavior of the composite was also described by a number of new analytical models developed or adapted for the material system studied. These models include the rule of mixtures, composite cylinder model with various thermoelastoplastic analyses and a model based on average field theory. In most cases satisfactory agreement was demonstrated between analytical predictions and experimental results for the cases of stress-strain behavior and thermal deformation behavior at different temperatures. In addition, some models yielded detailed three-dimensional stress distributions in the constituents within the composite.

Daniel, I. M.; Chun, H. J.; Karalekas, D.

1994-01-01

174

Extracellular Matrix Regulation of Autophagy  

PubMed Central

Summary Integrin-mediated attachment of epithelial cells to extracellular matrix (ECM) is critical for proper growth and survival. Although detachment leads to apoptosis, termed anoikis, recent work demonstrates that ECM detachment also robustly induces autophagy, a tightly regulated lysosomal self-digestion process that actually promotes survival. Autophagy presumably protects epithelial cells from the stresses of ECM detachment, allowing them to survive provided they reattach in a timely manner. Currently, the intracellular signals linking integrin engagement to autophagy remain unclear, but certain growth factor, energy-sensing, and stress response pathways represent attractive candidates. Moreover, autophagy may be a previously unrecognized mechanism utilized by detached cancer cells to survive anoikis, which may facilitate tumor cell dormancy, dissemination, and metastasis. PMID:18573652

Lock, Rebecca; Debnath, Jayanta

2008-01-01

175

Intermetallic bonded ceramic matrix composites  

SciTech Connect

A range of carbide and oxide-based cermets have been developed utilizing ductile nickel aluminide (Ni{sub 3}Al) alloy binder phases. Some of these, notably materials based upon tungsten and titanium carbides (WC and TiC respectively), offer potential as alternatives to the cermets which use cobalt binders (i.e. WC/Co). Samples have been prepared by blending commercially available Ni{sub 3}Al alloy powders with the desired ceramic phases, followed by hot-pressing. Alumina (Al{sub 2}O{sub 3}) matrix materials have also been prepared by pressurized molten alloy infiltration. The microstructure, flexure strength and fracture toughness of selected materials are discussed.

Plucknett, K.P.; Tiegs, T.N.; Alexander, K.B.; Becher, P.F.; Schneibel, J.H.; Waters, S.B.; Menchhofer, P.A. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1995-07-01

176

Mechanical behavior of fiber-reinforced ceramic-matrix composites  

Microsoft Academic Search

A detailed study of the matrix crack distribution and frictional heating phenomena in fiber-reinforced ceramic composites was undertaken. The distribution of matrix cracks in an uniaxial ceramic composite was examined to determine how the matrix strength distribution influences the distribution in matrix cracks. The analysis shows that matrix strength statistics have a significant effect on the distribution of matrix cracks

Chongdu

1991-01-01

177

Dirac oscillators and the relativistic R matrix  

SciTech Connect

The Dirac oscillators are shown to be an excellent expansion basis for solutions of the Dirac equation by R-matrix techniques. The combination of the Dirac oscillator and the R-matrix approach provides a convenient formalism for reactions as well as bound-state problems. The utility of the R-matrix approach is demonstrated in relativistic impulse approximation calculations where exchange terms can be calculated exactly and scattering waves made orthogonal to bound-state wave functions.

Grineviciute, J.; Halderson, Dean [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008 (United States)

2009-10-15

178

Matrix Bases for Star Products: a Review  

NASA Astrophysics Data System (ADS)

We review the matrix bases for a family of noncommutative star products based on a Weyl map. These products include the Moyal product, as well as the Wick-Voros products and other translation invariant ones. We also review the derivation of Lie algebra type star products, with adapted matrix bases. We discuss the uses of these matrix bases for field theory, fuzzy spaces and emergent gravity.

Lizzi, Fedele; Vitale, Patrizia

2014-08-01

179

Spectral Analysis of Gluonic Pole Matrix Elements  

E-print Network

We use a spectator framework to investigate the spectral properties of quark-quark-gluon correlators and use this to study gluonic pole matrix elements. Such matrix elements appear in principle both for distribution functions such as the Sivers function and fragmentation functions such as the Collins function. We find that the contribution of the gluonic pole matrix element in fragmentation functions vanishes. This outcome is important in the study of universality for fragmentation functions.

L. P. Gamberg; A. Mukherjee; P. J. Mulders

2008-07-08

180

Matrix Bases for Star Products: a Review  

E-print Network

We review the matrix bases for a family of noncommutative $\\star$ products based on a Weyl map. These products include the Moyal product, as well as the Wick-Voros products and other translation invariant ones. We also review the derivation of Lie algebra type star products, with adapted matrix bases. We discuss the uses of these matrix bases for field theory, fuzzy spaces and emergent gravity.

Fedele Lizzi; Patrizia Vitale

2014-03-04

181

Finding Nonoverlapping Substructures of a Sparse Matrix  

SciTech Connect

Many applications of scientific computing rely on computations on sparse matrices. The design of efficient implementations of sparse matrix kernels is crucial for the overall efficiency of these applications. Due to the high compute-to-memory ratio and irregular memory access patterns, the performance of sparse matrix kernels is often far away from the peak performance on a modern processor. Alternative data structures have been proposed, which split the original matrix A into A{sub d} and A{sub s}, so that A{sub d} contains all dense blocks of a specified size in the matrix, and A{sub s} contains the remaining entries. This enables the use of dense matrix kernels on the entries of A{sub d} producing better memory performance. In this work, we study the problem of finding a maximum number of nonoverlapping dense blocks in a sparse matrix, which is previously not studied in the sparse matrix community. We show that the maximum nonoverlapping dense blocks problem is NP-complete by using a reduction from the maximum independent set problem on cubic planar graphs. We also propose a 2/3-approximation algorithm that runs in linear time in the number of nonzeros in the matrix. This extended abstract focuses on our results for 2x2 dense blocks. However we show that our results can be generalized to arbitrary sized dense blocks, and many other oriented substructures, which can be exploited to improve the memory performance of sparse matrix operations.

Pinar, Ali; Vassilevska, Virginia

2005-08-11

182

Transferring elements of a density matrix  

E-print Network

We study restrictions imposed by quantum mechanics on the process of matrix elements transfer. This problem is at the core of quantum measurements and state transfer. Given two systems $\\A$ and $\\B$ with initial density matrices $\\lambda$ and $r$, respectively, we consider interactions that lead to transferring certain matrix elements of unknown $\\lambda$ into those of the final state ${\\widetilde r}$ of $\\B$. We find that this process eliminates the memory on the transferred (or certain other) matrix elements from the final state of $\\A$. If one diagonal matrix element is transferred, ${\\widetilde r}_{aa}=\\lambda_{aa}$, the memory on each non-diagonal element $\\lambda_{a\

Armen E. Allahverdyan; Karen V. Hovhannisyan

2010-07-08

183

A Study of Vandermonde-like Matrix Systems With Emphasis on Preconditioning and Krylov Matrix Connection.  

E-print Network

The study focuses primarily on Vandermonde-like matrix systems. The idea is to express Vandermonde and Vandermonde-like matrix systems as the problems related to Krylov Matrices. The connection provides a different angle to view the Vandermonde...

Saraswat, Jyoti

2009-06-11

184

Advanced Integration Matrix Education Outreach  

NASA Technical Reports Server (NTRS)

The Advanced Integration Matrix (AIM) will design a ground-based test facility for developing revolutionary integrated systems for joint human-robotic missions in order to study and solve systems-level integration issues for exploration missions beyond Low Earth Orbit (LEO). This paper describes development plans for educational outreach activities related to technological and operational integration scenarios similar to the challenges that will be encountered through this project. The education outreach activities will provide hands-on, interactive exercises to allow students of all levels to experience design and operational challenges similar to what NASA deals with everyday in performing the integration of complex missions. These experiences will relate to and impact students everyday lives by demonstrating how their interests in science and engineering can develop into future careers, and reinforcing the concepts of teamwork and conflict resolution. Allowing students to experience and contribute to real-world development, research, and scientific studies of ground-based simulations for complex exploration missions will stimulate interest in the space program, and bring NASA's challenges to the student level. By enhancing existing educational programs and developing innovative activities and presentations, AIM will support NASA s endeavor to "inspire the next generation of explorers.. .as only NASA can."

Paul Heather L.

2004-01-01

185

Non-relativistic Matrix Inflation  

E-print Network

We reconsider a string theoretic inflationary model, where inflation is driven by $n$ multiple coincident $D3$-branes in the finite $n$ limit. We show that the finite $n$ action can be continued to the limit of large $n$, where it converges to the action for a wrapped $D5$-brane with $n$ units of U(1) flux. This provides an important consistency check of the scenario and allows for more control over certain back-reaction effects. We determine the most general form of the action for a specific sub-class of models and examine the non-relativistic limits of the theory where the branes move at speeds much less than the speed of light. The non-Abelian nature of the world-volume theory implies that the inflaton field is matrix valued and this results in modifications to the slow-roll parameters and Hubble-flow equations. A specific small field model of inflation is investigated where the branes move out of an AdS throat, and observational constraints are employed to place bounds on the background fluxes.

Aaron Berndsen; James. E. Lidsey; John Ward

2009-08-28

186

Extracellular Matrix Abnormalities in Schizophrenia  

PubMed Central

Emerging evidence points to the involvement of the brain extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Abnormalities affecting several ECM components, including Reelin and chondroitin sulfate proteoglycans (CSPGs), have been described in subjects with this disease. Solid evidence supports the involvement of Reelin, an ECM glycoprotein involved in corticogenesis, synaptic functions and glutamate NMDA receptor regulation, expressed prevalently in distinct populations of GABAergic neurons, which secrete it into the ECM. Marked changes of Reelin expression in SZ have typically been reported in association with GABA-related abnormalities in subjects with SZ and bipolar disorder. Recent findings from our group point to substantial abnormalities affecting CSPGs, a main ECM component, in the amygdala and entorhinal cortex of subjects with schizophrenia, but not bipolar disorder. Striking increases of glial cells expressing CSPGs were accompanied by reductions of perineuronal nets, CSPG- and Reelin-enriched ECM aggregates enveloping distinct neuronal populations. CSPGs developmental and adult functions, including neuronal migration, axon guidance, synaptic and neurotransmission regulation are highly relevant to the pathophysiology of SZ. Together with reports of anomalies affecting several other ECM components, these findings point to the ECM as a key component of the pathology of SZ. We propose that ECM abnormalities may contribute to several aspects of the pathophysiology of this disease, including disrupted connectivity and neuronal migration, synaptic anomalies and altered GABAergic, glutamatergic and dopaminergic neurotransmission. PMID:21856318

Berretta, Sabina

2011-01-01

187

Micromechanics of the pericellular matrix  

NASA Astrophysics Data System (ADS)

In recent years, much attention has been directed towards the properties and activities of the cell surface. In particular, the coupling of the membrane to the underlying protein polymer network called the actin cortex plays an important role in many events. The other side of the cell surface is less studied, although it too has a bound polymer network comprised of gigantic cross-linked polysaccharides (sugars). Called the pericellular matrix (PCM), it is associated with many cells including fibroblasts, chondrocytes, endothelial and smooth muscle cells. Its thickness can vary from 10's of nanometers to 10 microns and it is associated with adhesion dependent events like migration and mitosis. Biologists often hypothesize that its viscoelastic properties are responsible for the modulation of cell adhesion activities. To investigate this proposal, we measure the PCM's viscoelasticity using microrheology and probe the sharpness of its edge and its mesh size. The elastic modulus of the PCM under different condition is determined, and we characterize the long, elastic cables that can be pulled from the PCM. These results are compared with an externally reconstituted model PCM on the cell surface.

Curtis, J. E.; Boehm, H.; Schmitz, C. H. J.; Spatz, J. P.

2006-03-01

188

On Genetic Algorithms for Boolean Matrix Factorization  

Microsoft Academic Search

Matrix factorization or factor analysis is an important task in the analysis of high dimensional real world data. There are several well known methods and algorithms for factorization of real data but they are rather inefficient when dealing with binary information. In this paper we introduce background and initial version of genetic algorithm for binary matrix factorization.

Václav Snásel; Jan Platos; Pavel Krömer

2008-01-01

189

Electromagnetic Compatibility of Matrix Converter System  

Microsoft Academic Search

Abstract. The presented paper ,deals with matrix converters pulse width modulation strategies design with emphasis on the ,electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many ,advantages compared to the conventional voltage or current

Ji?í Lettl; Stanislav Flígl

190

New control strategy for matrix converter  

Microsoft Academic Search

The authors propose a control strategy for the matrix converter which allows output voltage of 0.866 times the supply voltage to be generated. They discuss how to eliminate voltage and current spikes in the commutation. The system operation is examined and confirmed by experiments using a matrix converter with anti-parallel-connected SITs (static induction thyristors)

Jun Oyama; Tsuyoshi Higuchi; Eiji Yamada; Takashi Koga; Thomas Lipo

1989-01-01

191

Phenomenological studies in the matrix models  

E-print Network

Matrix models are a promising candidate for a nonperturbative formulation of the superstring theory. It is possible to study how the standard model and other phenomenological models appear from the matrix model, and estimate the probability distribution of their appearance. This article mainly addresses studies in toroidal compactifications with magnetic fluxes.

Hajime Aoki

2014-05-01

192

Interfaces in metal-matrix composites  

SciTech Connect

This book compiles papers examining interfacial behavior in metal matrix composites. Topics include mechanical properties, growth kinetics, modeling the interfacial behavior of flexible composites, interface structure in silicon carbide-silicon nitride composites, and the response of microstructures of metal matrix composites to solidification time.

Dhingra, A.K.; Fishman, S.G.

1986-01-01

193

Control system synthesis via bilinear matrix inequalities  

Microsoft Academic Search

This paper introduces the bilinear matrix inequality (BMI) as a simple but flexible framework for approaching robust control system synthesis problems. The BMI is an extension of the linear matrix inequality (LMI) approach that has recently been found to be useful in formulating and solving a limited class of robust control problems, including state-feedback and full-order dynamical output feedback H?

M. G. Saforiov; K. C. Goh; J. H. Ly

1994-01-01

194

Matrigel: Basement membrane matrix with biological activity  

Microsoft Academic Search

The basement membrane extracellular matrix contacts epithelial, endothelial, fat and smooth muscle cells. Because this extracellular matrix is so thin, it had been hard to study its composition, structure, and function. An extract of a tumor was found to contain all of the components present in basement and to be very biologically active. This extract, termed Matrigel, Cultrex, or EHS

Hynda K. Kleinman; George R. Martin

2005-01-01

195

A new generalized direct matrix converter  

Microsoft Academic Search

In this paper, the authors attempt to introduce a new modulation algorithm for matrix power converters, with an alternative PWM strategy, regardless of type of input and output (AC or DC), and also the number of input and output phases, by using suitable toggling matrix switches, such that favorable output patterns are achieved (with variable amplitudes and frequency). The switch

S. H. Hosseini; E. Babaei

2001-01-01

196

Generalized matrix tree theorem for mixed graphs  

Microsoft Academic Search

In this article we provide a combinatorial description of an arbitrary minor of the Laplacian matrix (L) of a mixed graph (a graph with some oriented and some unoriented edges). This is a generalized Matrix Tree Theorem. We also characterize the non-singular substructures of a mixed graph. The sign attached to a nonsingular substructure is described in terms of labeling

Ravindra B. Bapat; Jerrold W. Grossman; Devadatta M. Kulkarni

1999-01-01

197

Generalized Colourings (Matrix Partitions) of Cographs  

Microsoft Academic Search

Ordinary colourings of cographs are well understood; we focus on more general colourings, known as matrix partitions. We show that all matrix partition problems for cographs admit polynomial time algorithms and forbidden induced subgraph characterizations, even for the list version of the problems. Cographs are the largest natural class of graphs that have been shown to have this property. We

Tomás Feder; Pavol Hell; Winfried Hochstättler

198

HYGROTHERMAL AGING OF POLYIMIDE MATRIX COMPOSITE LAMINATES  

E-print Network

HYGROTHERMAL AGING OF POLYIMIDE MATRIX COMPOSITE LAMINATES John A. Nairn and Man-Hee Han Materials-0560, USA SUMMARY: Two polyimide-matrix systems were subjected to a series of hygrothermal aging experiments at various temperatures and relative humidities. For each aging condition, we measured the microcracking

Nairn, John A.

199

Matrix model description of baryonic deformations  

SciTech Connect

We investigate supersymmetric QCD with N{sub c} + 1 flavors using an extension of the recently proposed relation between gauge theories and matrix models.The impressive agreement between the two sides provides a beautiful confirmation of the extension of the gauge theory-matrix model relation to this case.

Bena, Iosif; Murayama, Hitoshi; Roiban, Radu; Tatar, Radu

2003-03-13

200

Alternate formulations for the manipulator inertia matrix  

Microsoft Academic Search

Four compact methods for computing the manipulator joint space inertia matrix are derived and compared. The derivation of the first, the Structurally Recursive Method, is based on the successive addition of single links to the free end of a serial manipulator. A general joint model allows multiple-degree-of-freedom joints to connect the links if desired, and the manipulator Jacobian matrix is

K. W. Lilly; D. E. Orin

1991-01-01

201

Learning the Kernel Matrix with Semidefinite Programming  

Microsoft Academic Search

Kernel-based learning algorithms work by embedding the data into a Euclidean space, and then searching for linear relations among the embedded data points. The embedding is performed implicitly, by specifying the inner products between each pair of points in the embedding space. This information is contained in the so-called kernel matrix, a symmetric and positive semidefinite matrix that encodes the

Gert R. G. Lanckriet; Nello Cristianini; Peter L. Bartlett; Laurent El Ghaoui; Michael I. Jordan

2004-01-01

202

FOCUS: MALDI Exploring Infrared Wavelength Matrix-  

E-print Network

FOCUS: MALDI Exploring Infrared Wavelength Matrix- Assisted Laser Desorption/Ionization of Proteins) to infrared-wavelength matrix-assisted time-of-flight mass spectrometry (IR-MALDI-TOF-MS) of proteins MALDI-mass spectrometry (MS) measurements of proteins make use of ultraviolet (UV) wavelength laser

Chait, Brian T.

203

COMMUNITY MATRIX IN THREE SPECIES COMMUNITY MODELS  

EPA Science Inventory

The explicit function of the community matrix of a three dimensional Lotka-Volterra model is delineated by a set of necessary and sufficient conditions for a positive equilibrium to be asymptotically stable. In the special case that the community matrix is quasi weakly diagonally...

204

Expression of extracellular matrix metalloproteinase inducer and matrix metalloproteinases during mouse embryonic development  

Microsoft Academic Search

Mouse embryo implantation is a highly invasive and controlled process that involves remodeling and degradation of the extracellular matrix of the uterus. Matrix metalloproteinases (MMPs) are the main proteinases facilitating this process. Extracellular matrix metalloproteinase inducer (EMMPRIN) can stimulate the production of MMPs and is required for successful implantation in the mouse. The aims of the present study were to

Li Chen; Masaaki Nakai; Robert J Belton Jr; Romana A Nowak

2007-01-01

205

Adaptive wavelet methods - Matrix-vector multiplication  

NASA Astrophysics Data System (ADS)

The design of most adaptive wavelet methods for elliptic partial differential equations follows a general concept proposed by A. Cohen, W. Dahmen and R. DeVore in [3, 4]. The essential steps are: transformation of the variational formulation into the well-conditioned infinite-dimensional l2 problem, finding of the convergent iteration process for the l2 problem and finally derivation of its finite dimensional version which works with an inexact right hand side and approximate matrix-vector multiplications. In our contribution, we shortly review all these parts and wemainly pay attention to approximate matrix-vector multiplications. Effective approximation of matrix-vector multiplications is enabled by an off-diagonal decay of entries of the wavelet stiffness matrix. We propose here a new approach which better utilize actual decay of matrix entries.

?erná, Dana; Fin?k, Václav

2012-12-01

206

Robust alternative minimization for matrix completion.  

PubMed

Recently, much attention has been drawn to the problem of matrix completion, which arises in a number of fields, including computer vision, pattern recognition, sensor network, and recommendation systems. This paper proposes a novel algorithm, named robust alternative minimization (RAM), which is based on the constraint of low rank to complete an unknown matrix. The proposed RAM algorithm can effectively reduce the relative reconstruction error of the recovered matrix. It is numerically easier to minimize the objective function and more stable for large-scale matrix completion compared with other existing methods. It is robust and efficient for low-rank matrix completion, and the convergence of the RAM algorithm is also established. Numerical results showed that both the recovery accuracy and running time of the RAM algorithm are competitive with other reported methods. Moreover, the applications of the RAM algorithm to low-rank image recovery demonstrated that it achieves satisfactory performance. PMID:22345545

Lu, Xiaoqiang; Gong, Tieliang; Yan, Pingkun; Yuan, Yuan; Li, Xuelong

2012-06-01

207

Graphical evaluation of relativistic matrix elements  

NASA Technical Reports Server (NTRS)

A graphical representation of angular momentum was used to evaluate relativistic matrix elements between antisymmetrized states of many particle configurations having any number of open shells. The antisymmetrized matrix element was expanded as a sum of semisymmetrized matrix elements. The diagram representing a semisymmetrized matrix element was composed of four diagram blocks; the bra block, the ket block, the spectator block, and the interaction block. The first three blocks indicate the couplings of the two interacting configurations while the last depends on the interaction and is the replaceable component. Interaction blocks for relativistic operators and commonly used potentials were summarized in ready to use forms. A simple step by step procedure was prescribed generally for calculating antisymmetrized matrix elements of one and two particle operators.

Huang, K. N.

1978-01-01

208

A note on quantization of matrix models  

E-print Network

The issue of non-perturbative background independent quantization of matrix models is addressed. The analysis is carried out by considering a simple matrix model which is a matrix extension of ordinary mechanics reduced to 0 dimension. It is shown that this model has an ordinary mechanical system evolving in time as a classical solution. But in this treatment the action principle admits a natural modification which results in algebraic relations describing quantum theory. The origin of quantization is similar to that in Adler's generalized quantum dynamics. The problem with extension of this formalism to many degrees of freedom is solved by packing all the degrees of freedom into a single matrix. The possibility to apply this scheme to field theory and to various matrix models is discussed.

Artem Starodubtsev

2002-06-12

209

[Proteolysis directed by the extracellular matrix].  

PubMed

The degradation of extracellular matrix (ECM) during physio-pathological processes involves, essentially, two proteolytic systems: the plasmin (ogen) system and the matrix metalloproteinase (MMP) family. Enzyme activity necessitates the formation of proteolytic cascades acting in the pericellular environment. Several proteins (proteases, integrins, matrix, inhibitors, activators...) participate to enzyme catalysis forming assemblies within specialized plasma membrane structures (invadopodia, caveolae). MMP-mediated ECM degradation leads to the formation of peptides (matricryptins, matrikins) which, in turn, can modulate MMP expression. MMPs (especially gelatinases) can also activate growth factors as pro TGF beta or liberate those factors from matrix sites. Interaction between matrix and gelatinases was shown to influence enzyme activation through several mechanisms. Finally, thrombospondins 1 and 2, matricellular proteins, can regulate gelatinase A by favoring its endocytosis. Those data emphasize the potential interest of certain matrikins or pseudo-matrikins as therapeutic agents to control cell invasion. PMID:12868263

Hornebeck, William; Emonard, Hervé; Maquart, François-Xavier; Bellon, Georges

2003-01-01

210

Profile information matrix for nonlinear transformation models  

PubMed Central

For semiparametric models, interval estimation and hypothesis testing based on the information matrix for the full model is a challenge because of potentially unlimited dimension. Use of the profile information matrix for a small set of parameters of interest is an appealing alternative. Existing approaches for the estimation of the profile information matrix are either subject to the curse of dimensionality, or are ad-hoc and approximate and can be unstable and numerically inefficient. We propose a numerically stable and efficient algorithm that delivers an exact observed profile information matrix for regression coefficients for the class of Nonlinear Transformation Models [A. Tsodikov (2003) J R Statist Soc Ser B 65:759–774]. The algorithm deals with the curse of dimensionality and requires neither large matrix inverses nor explicit expressions for the profile surface. PMID:17021958

Garibotti, G.

2010-01-01

211

Density Matrix in Quantum Mechanics and Distinctness of Ensembles Having the Same Compressed Density Matrix  

E-print Network

We clarify different definitions of the density matrix by proposing the use of different names, the full density matrix for a single-closed quantum system, the compressed density matrix for the averaged single molecule state from an ensemble of molecules, and the reduced density matrix for a part of an entangled quantum system, respectively. We show that ensembles with the same compressed density matrix can be physically distinguished by observing fluctuations of various observables. This is in contrast to a general belief that ensembles with the same compressed density matrix are identical. Explicit expression for the fluctuation of an observable in a specified ensemble is given. We have discussed the nature of nuclear magnetic resonance quantum computing. We show that the conclusion that there is no quantum entanglement in the current nuclear magnetic resonance quantum computing experiment is based on the unjustified belief that ensembles having the same compressed density matrix are identical physically. Related issues in quantum communication are also discussed.

Gui Lu Long; Yi-Fan Zhou; Jia-Qi Jin; Yang Sun; Hai-Woong Lee

2005-08-27

212

Chondrule rims and interchondrule matrix in UOC  

NASA Technical Reports Server (NTRS)

Opaque rims around chondrules and clasts were distinguished from opaque, interchondrule matrix apparently unrelated spatially to chondrules and clasts. Microprobe and electron microscope techniques were used. The mean chemical composition for dark rim and matrix in Bishunpur and Tieschitz are similar to the opaque matrix of Huss, et al. However, the mean dark rim compositions in Bishunpur have significantly higher Fe, and lower Na, K, Al and Si than opaque interchondrule matrix. The opaque matrix of Huss, et al, essentially lies between these compositions. In Tieschitz only rim material was observed. In Tieschitz the rims are Si-poor and dominated by normative olivine (Fo50). Again there is an Na, K, Al component but is often nepheline normative rather than albitic. It too is probably present as glass, Ashworth (pers.comm.). In Bishunpur rims as well as the silicate-FeS, FeNi layering described by Allen, et al, discontinuous layering was observed within the silicate portion. This is apparently due to variations in the proportions of the components, particularly in the glassy phase. In Bishunpur there is a strong genetic link between matrix and rims, although rims seem to have formed under different, possibly more oxidizing, conditions. Also the presence of the same component in rims, matrix chondrules, and clasts suggests a common source.

Alexander, C.; Hutchison, R.; Barber, D. J.

1984-01-01

213

Nuclear matrix proteins and hereditary diseases.  

PubMed

The review summarizes literature data on alterations of structure or expression of different nuclear matrix proteins in hereditary syndromes. From the point of view of involvement of nuclear matrix proteins in etiology and pathogenesis of the disease hereditary pathologies can be classified in pathologies with pathogenesis associated with defects of nuclear matrix proteins and pathologies associated to changes of the nuclear matrix protein spectrum. The first group includes laminopathies, hereditary diseases with abnormal nuclear-matrix associated proteins and triplet extension diseases associated with accumulation of abnormal proteins in the nuclear matrix. Laminopathies are hereditary diseases coupled to structural defects of the nuclear lamina. These diseases include Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy, dilated cardiomyopathy (DCM) with conduction system disease, familial partial lipodystrophy (FPLD), autosomal recessive axonal neuropathy (Charcot-Marie-Tooth disorder type 2, CMT2), mandibuloacral dysplasia (MAD), Hutchison Gilford Progeria syndrome (HGS), Greenberg Skeletal Dysplasia, and Pelger-Huet anomaly (PHA). Most of them are due to mutations in the lamin A/C gene, one - to mutations in emerin gene, some are associated with mutations in Lamin B receptor gene. In Werner's, Bloom's, Cockayne's syndromes, Fanconi anemia, multiple carboxylase deficiency mutations in nuclear matrix protein or enzyme gene lead to deficient DNA repair, abnormal regulation of cell growth and differentiation or other specific metabolic functions. Proteins with a long polyglutamic tract synthesized in the cells of patients with dentato-rubral and pallido-luysian atrophy, myotonic dystrophy and Huntington disease interfere with transcription on the nuclear matrix. Down's syndrome is a representative of the group of diseases with altered nuclear matrix protein spectrum. PMID:15865282

Sjakste, N; Sjakste, T

2005-03-01

214

Active Matrix OLED Test Report  

NASA Technical Reports Server (NTRS)

This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits from the environmental testing results by understanding its performance limitations/shortcomings to improve subsequent generations of AMOLED technology. Note that the AMOLED used in this test was not deSigned for the space environment but rather for commercial/industrial terrestrial applications.

Salazar, George

2013-01-01

215

Visual Matrix Clustering of Social Networks  

SciTech Connect

The prevailing choices to graphically represent a social network in today’s literature are a node-link graph layout and an adjacency matrix. Both visualization techniques have unique strengths and weaknesses when applied to different domain applications. In this article, we focus our discussion on adjacency matrix and how to turn the matrix-based visualization technique from merely showing pairwise associations among network actors (or graph nodes) to depicting clusters of a social network. We also use node-link layouts to supplement the discussion.

Wong, Pak C.; Mackey, Patrick S.; Foote, Harlan P.; May, Richard A.

2013-07-01

216

Modified engagement method for matrix operation  

NASA Astrophysics Data System (ADS)

We describe a modified engagement method for matrix operation based on a two-dimensional crossed-ring interconnection network. Our method incorporates fewer steps than that reported by Bocker et al. [Appl. Opt. 22, 804 (1983)], and its performance is found to be the most efficient (minimum steps) in comparison with other systolic and/or engagement methods for matrix operation. Thus, it may be helpful for other optical and electronic implementations of matrix operations. One compact optoelectronic integrity approach for implementing the modified engagement method is briefly described.

Zhou, Changhe; Liu, Liren; Li, Guoqiang; Ying, Yaozu

1995-11-01

217

Extracellular Matrix Signaling in Morphogenesis and Repair  

PubMed Central

The extracellular matrix (ECM) is critically important for many cellular processes including growth, differentiation, survival, and morphogenesis. Cells remodel and reshape the ECM by degrading and reassembling it, playing an active role in sculpting their surrounding environment and directing their own phenotypes. Both mechanical and biochemical molecules influence ECM dynamics in multiple ways; by releasing small bioactive signaling molecules, releasing growth factors stored within the ECM, eliciting structural changes to matrix proteins which expose cryptic sites and by degrading matrix proteins directly. The dynamic reciprocal communication between cells and the ECM plays a fundamental roll in tissue development, homeostasis, and wound healing. PMID:23726156

Clause, Kelly C.; Barker, Thomas H.

2013-01-01

218

Learned fusion operators based on matrix completion  

NASA Astrophysics Data System (ADS)

The efficient and timely management of imagery captured in the battlefield requires methods capable of searching the voluminous databases and extracting highly symbolic concepts. When processing images, a semantic and definition gap exists between machine representations and the user's language. Based on matrix completion techniques, we present a fusion operator that fuses imagery and expert knowledge provided by user inputs during post analysis. Specifically, an information matrix is formed from imagery and a class map as labeled by an expert. From this matrix an image operator is derived for the extraction/prediction of information from future imagery. We will present results using this technique on single mode data.

Risko, Kelly K. D.; Hester, Charles F.

2011-05-01

219

LBM simulations of matrix diffusion with sorption  

NASA Astrophysics Data System (ADS)

Matrix diffusion is a phenomenon in which tracer particles convected along a flow channel can diffuse into porous walls of the channel, and it causes a delay and broadening of the breakthrough curve of the tracer pulse. The lattice-Boltzmann method is a popular tool for simulating flow through porous materials, and for similar reasons it is an attractive tool for modeling the matrix diffusion phenomenon. In this work sorption of the tracer particles is also included in such simulations with this method. The proposed approach is compared with conventional methods for modeling matrix diffusion phenomena.

Toivanen, Jukka I.; Mattila, Keijo; Puurtinen, Tuomas; Timonen, Jussi

2014-10-01

220

Earthquake prediction decision and risk matrix  

NASA Astrophysics Data System (ADS)

The issuance of an earthquake prediction must cause widespread social responses. It is suggested and discussed in this paper that the comprehensive decision issue for earthquake prediction considering the factors of the social and economic cost. The method of matrix decision for earthquake prediction (MDEP) is proposed in this paper and it is based on the risk matrix. The goal of decision is that search the best manner issuing earthquake prediction so that minimize the total losses of economy. The establishment and calculation of the risk matrix is discussed, and the decision results taking account of economic factors and not considering the economic factors are compared by examples in this paper.

Zou, Qi-Jia

1993-08-01

221

Consistent thermodynamic derivative estimates for tabular equations of state  

Microsoft Academic Search

Numerical simulations of compressible fluid flows require an equation of\\u000astate (EOS) to relate the thermodynamic variables of density, internal energy,\\u000atemperature, and pressure. A valid EOS must satisfy the thermodynamic\\u000aconditions of consistency (derivation from a free energy) and stability\\u000a(positive sound speed squared). When phase transitions are significant, the EOS\\u000ais complicated and can only be specified in

Gary A. Dilts

2006-01-01

222

MHD simulations of MTF implosions with tabular EOS and conductivities  

Microsoft Academic Search

Magnetized target fusion (MTF) is a pulsed approach that compresses magnetized fuel to achieving burning hydrogen plasma conditions. The compression in one MTF-scenario comes from uses a conducting liner that is imploded due to the action of high electrical currents that flow on the outer surface of the liner. This implosion compresses and heats a dense, warm magnetized deuterium or

R. J. Faehl; W. L. Atchison; I. R. Lindemuth

2003-01-01

223

A heuristic block coordinate descent approach for controlled tabular ...  

E-print Network

of up to 2,400,000 continuous variables, 100,000 binary variables, and 475,000 ... safe dissemination of European business and animal production statistics by ..... Two strategies have been tested, which can be viewed as a framework whose

2010-11-05

224

The phase transition of matrix recovery from Gaussian measurements matches the minimax MSE of matrix denoising  

PubMed Central

Let be an unknown M by N matrix. In matrix recovery, one takes linear measurements of , where and each is an M by N matrix. A popular approach for matrix recovery is nuclear norm minimization (NNM): solving the convex optimization problem for all , where denotes the nuclear norm, namely, the sum of singular values. Empirical work reveals a phase transition curve, stated in terms of the undersampling fraction , rank fraction , and aspect ratio . Specifically when the measurement matrices Ai have independent standard Gaussian random entries, a curve exists such that, if , NNM typically succeeds for large M,N, whereas if , it typically fails. An apparently quite different problem is matrix denoising in Gaussian noise, in which an unknown M by N matrix is to be estimated based on direct noisy measurements , where the matrix Z has independent and identically distributed Gaussian entries. A popular matrix denoising scheme solves the unconstrained optimization problem . When optimally tuned, this scheme achieves the asymptotic minimax mean-squared error , where . We report extensive experiments showing that the phase transition in the first problem, matrix recovery from Gaussian measurements, coincides with the minimax risk curve in the second problem, matrix denoising in Gaussian noise: , for any rank fraction (at each common aspect ratio ?). Our experiments considered matrices belonging to two constraint classes: real M by N matrices, of various ranks and aspect ratios, and real symmetric positive-semidefinite N by N matrices, of various ranks. PMID:23650360

Donoho, David L.; Gavish, Matan; Montanari, Andrea

2013-01-01

225

Matrix metalloproteinase-7 and matrix metalloproteinase-9 in pediatric multiple sclerosis.  

PubMed

Matrix metalloproteinases and their tissue inhibitors play a key role in the pathogenesis of adult-onset multiple sclerosis, and were suggested as biomarkers of response to interferon-?, an established treatment in multiple sclerosis. However, data regarding pediatric population are scarce. We determined serum levels of matrix metalloproteinase-7, matrix metalloproteinase-9, and tissue inhibitor of matrix metalloproteinase-1 in children, and evaluated effects of interferon-? therapy on these measures. Serum samples from 14 children with relapsing, remitting multiple sclerosis at baseline and at month 12, and from 15 controls, were collected. Interferon-? treatment was initiated in eight patients. Mean serum matrix metalloproteinase-9 levels and matrix metalloproteinase-9/tissue inhibitor of matrix metalloproteinase-1 ratio were higher in patients compared with controls, and were reduced significantly in treated patients at month 12, but did not change in untreated patients. Mean matrix metalloproteinase-7 levels were lower in patients compared with controls, and increased significantly in the treated group, but did not change significantly in the untreated group. In pediatric multiple sclerosis, a shift in matrix metalloproteinase-9/tissue inhibitor of matrix metalloproteinase-1 balance toward proteolytic activity is evident, and interferon-? therapy demonstrates a beneficial effect on this disturbed balance. PMID:22883281

Y?lmaz, Ünsal; Unsal, Y?lmaz; Gücüyener, K?v?lc?m; K?v?lc?m, Gücüyener; Atak, Ay?egül; Ay?egül, Atak; Aral, Arzu; Arzu, Aral; Gürka?, Esra; Esra, Gürka?; Demir, Ercan; Ercan, Demir; Serdaro?lu, Ay?e; Ay?e, Serdaro?lu

2012-09-01

226

Sensitivity analysis of periodic matrix population models.  

PubMed

Periodic matrix models are frequently used to describe cyclic temporal variation (seasonal or interannual) and to account for the operation of multiple processes (e.g., demography and dispersal) within a single projection interval. In either case, the models take the form of periodic matrix products. The perturbation analysis of periodic models must trace the effects of parameter changes, at each phase of the cycle, on output variables that are calculated over the entire cycle. Here, we apply matrix calculus to obtain the sensitivity and elasticity of scalar-, vector-, or matrix-valued output variables. We apply the method to linear models for periodic environments (including seasonal harvest models), to vec-permutation models in which individuals are classified by multiple criteria, and to nonlinear models including both immediate and delayed density dependence. The results can be used to evaluate management strategies and to study selection gradients in periodic environments. PMID:23316494

Caswell, Hal; Shyu, Esther

2012-12-01

227

Plato's Fire and the Neutrino Mass Matrix  

E-print Network

With the accumulation of many years of solar and atmospheric neutrino oscillation data, the approximate form of the 3 X 3 neutrino mixing matrix is now known. The theoretical challenge is to understand where this mixing matrix comes from. Recently, a remarkable fact was discovered that for a specific pattern of the neutrino mass matrix at a high scale, any flavor-changing radiative correction will automatically lead to the desired mixing matrix. It was also discovered that the required specific pattern at the high scale can be maintained by the non-Abelian discrete symmetry A_4 which is also the symmetry group of the regular tetrahedron, one of five perfect geometric solids known to Plato who associated it with the element ``fire''. I discuss this recent development and add to it a new and very simple mechanism for the implementation of the flavor-changing radiative correction.

Ernest Ma

2002-11-25

228

On Wavelet Matrix Compression for Differential Equations  

NASA Astrophysics Data System (ADS)

The design of most adaptive wavelet methods for solving differential equations follows a general concept proposed by A. Cohen, W. Dahmen and R. DeVore in [5, 6]. The essential steps are: transformation of the variational formulation into the well-conditioned infinite-dimensional l2 problem, finding of the convergent iteration process for the l2 problem and finally derivation of its finite dimensional version which works with an inexact right hand side and approximate matrix-vector multiplication. In our contribution, we shortly review all these parts with emphasis on the approximate matrix-vector multiplication. Efficient approximation of matrix-vector multiplication is enabled by an off-diagonal decay of entries of the wavelet stiffness matrix and by decay of entries of load vector in wavelet coordinates. Besides an usual truncation in scale, we apply here also a truncation in space to compress wavelet stiffness matrices efficiently. At the end, we show some numerical experiments.

?erná, Dana; Fin?k, Václav

2011-09-01

229

Fiber coatings for ceramic matrix composites  

SciTech Connect

Two fiber coating concepts for ceramic matrix composites were successfully demonstrated in a preliminary study. These coatings were designed to promote toughness in composites and resist oxidation. The concepts were: (1) thin, multiple unbonded layers, and (2) a single porous layer that provided low interfacial strengths between the fiber and matrix. Chemical vapor deposited (CVD) SiC and sol-gel derived oxides were used to produce the fiber coatings. Specimens consisted of a single coated monofilament fiber and a sheath of CVD SiC to represent the matrix. Results from flexure tests showed that matrix cracks were deflected and that fibers debonded the same as in specimens made using carbon-coated fibers. Crack deflection and fiber debonding were also evident after exposure in air at elevated temperatures. 5 refs.

Carpenter, H.W.; Bohlen, J.W.

1992-08-01

230

The Extracellular Matrix: Not Just Pretty Fibrils  

E-print Network

The extracellular matrix (ECM) and ECM proteins are important in phenomena as diverse as developmental patterning, stem cell niches, cancer, and genetic diseases. The ECM has many effects beyond providing structural support. ...

Hynes, Richard O.

231

Software for Fault-Tolerant Matrix Multiplication  

NASA Technical Reports Server (NTRS)

Formal Linear Algebra Recovery Environment is a computer program for high-performance, fault-tolerant matrix multiplication. The program is based on an extension of the prior theory and practice of fault-tolerant matrix matrix multiplication of the form C = AB. This extension provides low-overhead methods for detecting errors, not only in C, but also in A and/or B. These methods enable the detection of all errors as long as, in a given case, only one entry in A, B, or C is corrupted. The program also provides for following a low-overhead rollback approach to correct errors once detected. Results of computational experiments have demonstrated that the methods implemented in this program work well in practice while imposing an acceptably low level of overhead, relative to high-performance matrix-multiplication methods that do not afford fault tolerance.

Katz, Daniel; Tisdale, Edwin; Quintana-Orti, Enrique; Gunnels, John; van de Geijn, Robert

2004-01-01

232

Matrix Factorization Techniques for Recommender Systems  

Microsoft Academic Search

As the Netflix Prize competition has demonstrated, matrix factorization models are superior to classic nearest neighbor techniques for producing product recommendations, allowing the incorporation of additional information such as implicit feedback, temporal effects, and confidence levels.

Yehuda Koren; Robert M. Bell; Chris Volinsky

2009-01-01

233

Transition Matrix Elements for Pion Photoproduction  

E-print Network

We have obtained the transition matrix elements for pion photoproduction by considering the number of gamma matrices involved. The approach based on the most general conditions of gauge invariance, current conservation and transversality. The approach is fairly consistent with literatures.

Mohamed E. Kelabi

2007-03-20

234

Quantum restrictions on transfer of matrix elements  

E-print Network

We discuss restrictions imposed by quantum mechanics on the process of matrix elements transfer from the one system to another. This is relevant for various processes of partial state transfer (quantum communication, indirect measurement, polarization transfer, {\\it etc}). Given two systems A and B with initial density operators $\\lambda$ and $r$, respectively, we consider most general interactions, which lead to transferring certain matrix elements of unknown $\\lambda$ into those of the final state ${\\widetilde r}$ of B. We find that this process leads to eliminating the memory on the transferred (or certain other) matrix elements from the final state of A. If one diagonal matrix element is transferred: ${\\widetilde r}_{aa}=\\lambda_{aa}$, the memory on each non-diagonal element $\\lambda_{a\

Armen E. Allahverdyan; Karen Hovhannisyan

2008-11-15

235

A generalized resultant matrix for polynomial matrices  

Microsoft Academic Search

We present a generalized resultant matrix and a fast algorithm for testing the coprimeness of two polynomial matrices, extracting their great common divisor, finding the McMillan degree and the observability indices of the associated minimal realization.

S. Y. Kung; T. Kailath; M. Morf

1976-01-01

236

The evolution of metazoan extracellular matrix  

E-print Network

The modular domain structure of extracellular matrix (ECM) proteins and their genes has allowed extensive exon/domain shuffling during evolution to generate hundreds of ECM proteins. Many of these arose early during metazoan ...

Hynes, Richard O.

237

Large deviation bounds for matrix Brownian motion  

Microsoft Academic Search

.   We prove large deviation bounds for the convergence of Hermitian matrix valued Brownian motion towards free Brownian motion.\\u000a As a consequence, we obtain upper and lower bounds on the microstates entropy introduced by Voiculescu [24].

P. Biane; M. Capitaine; A. Guionnet

2003-01-01

238

Practical preventive reliability using matrix forms  

NASA Technical Reports Server (NTRS)

This paper describes a practical new tool to improve the reliability of equipment. It uses a matrix form to help monitor anticipated component faults precisely. The tool provides the practical measures necessary to generate matrix tables that accurately display all causes of failure and all planned programmatic analyses, tests, processes, and inspections. When completed, the matrix tables give users in-depth visibility of the degree of protection against component failure that is provided by the program's preventive measure plans. The matrix form is an excellent technique for tracking, and thereby influencing, the reliability of nonelectronic spacecraft subsystems or components. No electronic applications have been tried, but the procedure can be useful in the electronics field, e.g., in integrated circuit production planning, and perhaps in process control, inspection or test lines for other electronic components. The drawing of forms, and the recording/manipulation of the data can be computerized.

Johnson, S. A.

1983-01-01

239

Near commuting multi-matrix models  

NASA Astrophysics Data System (ADS)

We investigate the radial extent of the eigenvalue distribution for Yang-Mills type matrix models. We show that, a three matrix Gaussian model with complex Myers coupling, to leading order in strong coupling is described by commuting matrices whose joint eigenvalue distribution is uniform and confined to a ball of radius R={{( {{3? }/2g } )}^{{{1 / {3} .}}}} . We then study, perturbatively, a 3-component model with a pure commutator action and find a radial extent broadly consistent with numerical simulations.

O'Connor, Denjoe; Filev, Veselin G.

2013-04-01

240

Nanophosphor composite scintillator with a liquid matrix  

DOEpatents

An improved nanophosphor scintillator liquid comprises nanophosphor particles in a liquid matrix. The nanophosphor particles are optionally surface modified with an organic ligand. The surface modified nanophosphor particle is essentially surface charge neutral, thereby preventing agglomeration of the nanophosphor particles during dispersion in a liquid scintillator matrix. The improved nanophosphor scintillator liquid may be used in any conventional liquid scintillator application, including in a radiation detector.

McKigney, Edward Allen (Los Alamos, NM); Burrell, Anthony Keiran (Los Alamos, NM); Bennett, Bryan L. (Los Alamos, NM); Cooke, David Wayne (Santa Fe, NM); Ott, Kevin Curtis (Los Alamos, NM); Bacrania, Minesh Kantilal (Los Alamos, NM); Del Sesto, Rico Emilio (Los Alamos, NM); Gilbertson, Robert David (Los Alamos, NM); Muenchausen, Ross Edward (Los Alamos, NM); McCleskey, Thomas Mark (Los Alamos, NM)

2010-03-16

241

Cryogenic regenerator including sarancarbon heat conduction matrix  

NASA Technical Reports Server (NTRS)

A saran carbon matrix is employed to conduct heat through the heat storing volume of a cryogenic regenerator. When helium is adsorbed into the saran carbon matrix, the combination exhibits a volumetric specific heat much higher than previously used lead balls. A helium adsorbed saran regenerator should allow much lower refrigerator temperatures than those practically obtainable with lead based regenerators for regenerator type refrigeration systems.

Jones, Jack A. (Inventor); Petrick, S. Walter (Inventor); Britcliffe, Michael J. (Inventor)

1989-01-01

242

Semiclassical matrix elements from periodic orbits  

NASA Technical Reports Server (NTRS)

An extension of Gutzwiller's (1967, 1969, 1970, 1971, 1990) semiclassical theory for chaotic systems that allows a determination of matrix elements in terms of classical periodic orbits. Associated zeta functions are derived. The semiclassical predictions are found to be in good agreement with Fourier transforms of quantum spectra of hydrogen in a magnetic field. Expressions for off-diagonal matrix elements are derived that are extensions of the Bohr correspondence relations for integrable systems.

Eckhardt, B.; Fishman, S.; Mueller, K.; Wintgen, D.

1992-01-01

243

Semisupervised kernel matrix learning by kernel propagation.  

PubMed

The goal of semisupervised kernel matrix learning (SS-KML) is to learn a kernel matrix on all the given samples on which just a little supervised information, such as class label or pairwise constraint, is provided. Despite extensive research, the performance of SS-KML still leaves some space for improvement in terms of effectiveness and efficiency. For example, a recent pairwise constraints propagation (PCP) algorithm has formulated SS-KML into a semidefinite programming (SDP) problem, but its computation is very expensive, which undoubtedly restricts PCPs scalability in practice. In this paper, a novel algorithm, called kernel propagation (KP), is proposed to improve the comprehensive performance in SS-KML. The main idea of KP is first to learn a small-sized sub-kernel matrix (named seed-kernel matrix) and then propagate it into a larger-sized full-kernel matrix. Specifically, the implementation of KP consists of three stages: 1) separate the supervised sample (sub)set X(l) from the full sample set X; 2) learn a seed-kernel matrix on X(l) through solving a small-scale SDP problem; and 3) propagate the learnt seed-kernel matrix into a full-kernel matrix on X . Furthermore, following the idea in KP, we naturally develop two conveniently realizable out-of-sample extensions for KML: one is batch-style extension, and the other is online-style extension. The experiments demonstrate that KP is encouraging in both effectiveness and efficiency compared with three state-of-the-art algorithms and its related out-of-sample extensions are promising too. PMID:20923733

Hu, Enliang; Chen, Songcan; Zhang, Daoqiang; Yin, Xuesong

2010-11-01

244

Turnover of matrix proteins in mammalian mitochondria.  

PubMed Central

In cultured hepatocytes the turnover of several mitochondrial matrix proteins (e.g. acetyl-CoA acetyltransferase) appears to be initiated by CoA-mediated, sequential transformation into CoA-modified forms. This modification favours the notion that intramitochondrial degradation by a matrix-resident ATP-dependent protease may be preceded by a specific modification by CoA. In a mitochondrial matrix fraction the MgATP-dependent decrease in anti-CoA immunoreactivity coincided with both a decrease in the anti-protein immunoreactivity of acetyl-CoA acetyltransferase and/or of 3-ketoacyl-CoA thiolase, and with the appearance of proteolytic fragments. A closer analysis of the degradation pattern revealed, however, a breakdown of the unmodified acetyl-CoA acetyltransferase and of its CoA-modified form, A1, whereas the form that is more highly modified by CoA, A2, proved to be inaccessible towards an ATP-dependent protease. In mammalian mitochondrial matrix, proteins can be degraded selectively by a matrix-resident ATP-dependent protease. The process of CoA modification results finally in the protection of matrix proteins from degradation. In cultured hepatocytes, leupeptin, an inhibitor of lysosomal proteases, did not affect the steady-state level of the mitochondrial matrix protein acetyl-CoA acetyltransferase. However, leupeptin mediated a specific accumulation of mitochondrial matrix proteins in the cytosolic fractions of hepatocytes cultured over a 24 h period. The levels of acetyl-CoA acetyltransferase, 3-ketoacyl-CoA thiolase and glutamate dehydrogenase proteins increased 1.9-, 2.0- and 2.2-fold respectively. Their status as mature, oligomeric, but enzymically inactive enzymes strongly suggests that they originate from a leakage of autophagosomes, a constituent of the non-selective autophagic/lysosomal pathway for degradation of whole mitochondria. PMID:11988101

Huth, Walter; Rolle, Stefan; Wunderlich, Ilona

2002-01-01

245

Matching Parton Showers and Matrix Elements  

E-print Network

We compare different procedures for combining fixed-order tree-level matrix element generators with parton showers. We use the case of W-production at the Tevatron and the LHC to compare different implementations of the so-called CKKW scheme and one based on the so-called MLM scheme using different matrix element generators and different parton cascades. We find that although similar results are obtained in all cases, there are important differences.

Stefan Hoeche; Frank Krauss; Nils Lavesson; Leif Lonnblad; Michelangelo Mangano; Andreas Schaelicke; Steffen Schumann

2006-02-03

246

Application of Fuzzy Logic to Matrix FMECA  

NASA Astrophysics Data System (ADS)

A methodology combining the benefits of Fuzzy Logic and Matrix FMEA is presented in this paper. The presented methodology extends the risk prioritization beyond the conventional Risk Priority Number (RPN) method. Fuzzy logic is used to calculate the criticality rank. Also the matrix approach is improved further to develop a pictorial representation retaining all relevant qualitative and quantitative information of several FMEA elements relationships. The methodology presented is demonstrated by application to an illustrative example.

Shankar, N. Ravi; Prabhu, B. S.

2001-04-01

247

State dependence of pairing matrix elements  

Microsoft Academic Search

The influence of the state dependence of pairing matrix elements on deformation energies has been investigated. The prolate-oblate model was found to be too arbitrary for this purpose. Calculations using a delta-force show variations of the pairing energies of up to 1 MeV. The correlation between these matrix elements and a prolateness parameter has been investigated as well as the

D. Glas; U. Mosel

1973-01-01

248

Plant Cell Wall Matrix Polysaccharide Biosynthesis  

Microsoft Academic Search

The wall of an expanding plant cell consists primarily of cellulose microfibrils embedded in a matrix of hemi- cellulosic and pectic polysaccharides along with small amounts of structural and enzymatic proteins. Matrix polysacchar- ides are synthesized in the Golgi and exported to the cell wall by exocytosis, where they intercalate among cellulose microfibrils, whicharemadeattheplasmamembraneanddirectlydepositedintothecellwall.InvolvementofGolgiglucan synthesis in auxin-induced cell expansion has

Ajay Pal; S. Sandhu; Gursharn S. Randhawa; Kanwarpal S. Dhugga

249

Density matrix form of Gross-Pitaevskii equation  

E-print Network

We consider the generalized pure state density matrix which depends on di?erent time moments. The evolution equation for this density matrix is obtained in case where the density matrix corresponds to the solutions of Gross-Pitaevskii equation.

V. N. Chernega; O. V. Man'ko; V. I. Man'ko

2014-04-28

250

Genetic Relationships Between Chondrules, Rims and Matrix  

NASA Technical Reports Server (NTRS)

The most primitive chondrites are composed of chondrules and chondrule fragments, various types of inclusions, discrete mineral grains, metal, sulfides, and fine-grained materials that occur as interchondrule matrix and as chondrule/inclusion rims. Understanding how these components are related is essential for understanding how chondrites and their constituents formed and were processed in the solar nebula. For example, were the first generations of chondrules formed by melting of matrix or matrix precursors? Did chondrule formation result in appreciable transfer of chondrule material into the matrix? Here, we consider three types of data: 1) compositional data for bulk chondrites and matrix, 2) mineralogical and textural information, and 3) the abundances and characteristics of presolar materials that reside in the matrix and rims. We use these data to evaluate the roles of evaporation and condensation, chondrule formation, mixing of different nebular components, and secondary processing both in the nebula and on the parent bodies. Our goal is to identify the things that are reasonably well established and to point out the areas that need additional work.

Huss, G. R.; Alexander, C. M. OD.; Palme, H.; Bland, P. A.; Wasson, J. T.

2004-01-01

251

Sparse estimation of a covariance matrix.  

PubMed

We suggest a method for estimating a covariance matrix on the basis of a sample of vectors drawn from a multivariate normal distribution. In particular, we penalize the likelihood with a lasso penalty on the entries of the covariance matrix. This penalty plays two important roles: it reduces the effective number of parameters, which is important even when the dimension of the vectors is smaller than the sample size since the number of parameters grows quadratically in the number of variables, and it produces an estimate which is sparse. In contrast to sparse inverse covariance estimation, our method's close relative, the sparsity attained here is in the covariance matrix itself rather than in the inverse matrix. Zeros in the covariance matrix correspond to marginal independencies; thus, our method performs model selection while providing a positive definite estimate of the covariance. The proposed penalized maximum likelihood problem is not convex, so we use a majorize-minimize approach in which we iteratively solve convex approximations to the original nonconvex problem. We discuss tuning parameter selection and demonstrate on a flow-cytometry dataset how our method produces an interpretable graphical display of the relationship between variables. We perform simulations that suggest that simple elementwise thresholding of the empirical covariance matrix is competitive with our method for identifying the sparsity structure. Additionally, we show how our method can be used to solve a previously studied special case in which a desired sparsity pattern is prespecified. PMID:23049130

Bien, Jacob; Tibshirani, Robert J

2011-12-01

252

SevenOperators, a Mathematica script for harmonic oscillator nuclear matrix elements arising in semileptonic electroweak interactions  

NASA Astrophysics Data System (ADS)

Semi-leptonic electroweak interactions in nuclei—such as ? decay, ? capture, charged- and neutral-current neutrino reactions, and electron scattering—are described by a set of multipole operators carrying definite parity and angular momentum, obtained by projection from the underlying nuclear charge and three-current operators. If these nuclear operators are approximated by their one-body forms and expanded in the nucleon velocity through order |p?|/M, where p? and M are the nucleon momentum and mass, a set of seven multipole operators is obtained. Nuclear structure calculations are often performed in a basis of Slater determinants formed from harmonic oscillator orbitals, a choice that allows translational invariance to be preserved. Harmonic-oscillator single-particle matrix elements of the multipole operators can be evaluated analytically and expressed in terms of finite polynomials in q, where q is the magnitude of the three-momentum transfer. While results for such matrix elements are available in tabular form, with certain restriction on quantum numbers, the task of determining the analytic form of a response function can still be quite tedious, requiring the folding of the tabulated matrix elements with the nuclear density matrix, and subsequent algebra to evaluate products of operators. Here we provide a Mathematica script for generating these matrix elements, which will allow users to carry out all such calculations by symbolic manipulation. This will eliminate the errors that may accompany hand calculations and speed the calculation of electroweak nuclear cross sections and rates. We illustrate the use of the new script by calculating the cross sections for charged- and neutral-current neutrino scattering in 12C. Program summaryProgram title: SevenOperators Catalogue identifier: AEAY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 2227 No. of bytes in distributed program, including test data, etc.: 19 382 Distribution format: tar.gz Programming language: Mathematica Computer: Any computer running Mathematica; tested on Mac OS X PowerPC (32-bit) running Mathematica 6.0.0 Operating system: Any running Mathematica RAM: Memory requirements determined by Mathematica; 512 MB or greater RAM and hard drive space of at least 3.0 GB recommended Classification: 17.16, 17.19 Nature of problem: Algebraic evaluation of harmonic oscillator nuclear matrix elements for the one-body multipole operators governing semi-leptonic weak interactions, such as charged- or neutral-current neutrino scattering off nuclei. Solution method: Mathematica evaluation of associated angular momentum algebra and spherical Bessel function radial integrals. Running time: Depends on the complexity of the one-body density matrix employed, but times of a few seconds are typical.

Haxton, Wick; Lunardini, Cecilia

2008-09-01

253

The role of matrix cracks and fibre\\/matrix debonding on the stress transfer between fibre and matrix in a single fibre fragmentation test  

Microsoft Academic Search

The single fibre fragmentation test is commonly used to characterise the fibre\\/matrix interface. During fragmentation, the stored energy is released resulting in matrix cracking and\\/or fibre\\/matrix debonding.Axisymmetric finite element models were formulated to study the impact of matrix cracks and fibre\\/matrix debonding on the effective stress transfer efficiency (EST) and stress transfer length (STL). At high strains, plastic deformation in

Anbu Clemensis Johnson; Simon A. Hayes; Frank R. Jones

254

INTEGRATED COI S200 - Hi-NiCalon FIBER WITH AN S200 MATRIX (POLYMER MATRIX COMPOSITE - PMC) / AETB 1  

NASA Technical Reports Server (NTRS)

INTEGRATED COI S200 - Hi-NiCalon FIBER WITH AN S200 MATRIX (POLYMER MATRIX COMPOSITE - PMC) / AETB 16 (FOAM CORE) / CARBON REINFORCED CYANOESTER (CERAMIC MATRIX COMPOSITE - CMC) HOT STRUCTURE, PANEL 884-1: SAMPLE 1

2003-01-01

255

INTEGRATED COI S200 - Hi-NiCalon FIBER WITH AN S200 MATRIX (POLYMER MATRIX COMPOSITE - PMC) / AETB 1  

NASA Technical Reports Server (NTRS)

INTEGRATED COI S200 - Hi-NiCalon FIBER WITH AN S200 MATRIX (POLYMER MATRIX COMPOSITE - PMC) / AETB 16 (FOAM CORE) / CARBON REINFORCED CYANOESTER (CERAMIC MATRIX COMPOSITE - CMC) HOT STRUCTURE, PANEL 884-1: SAMPLE 3

2003-01-01

256

Extreme ranks of a linear quaternion matrix expression subject to triple quaternion matrix equations with applications  

Microsoft Academic Search

In this paper, we establish the formulas of the maximal and minimal ranks of the quaternion matrix expression C4-A4XB4 where X is a variant quaternion matrix subject to quaternion matrix equations A1X=C1,XB2=C2,A3XB3=C3. As applications, we give a new necessary and sufficient condition for the existence of solutions to the system of matrix equations A1X=C1,XB2=C2,A3XB3=C3,A4XB4=C4, which was investigated by Wang [Q.W.

Qing-wen Wang; Shao-wen Yu; Chun-yan Lin

2008-01-01

257

Auger analysis of a fiber/matrix interface in a ceramic matrix composite  

NASA Technical Reports Server (NTRS)

Auger electron spectroscopy (AES) depth profiling was used to characterize the fiber/matrix interface of an SiC fiber, reaction bonded Si3N4 matrix composite. Depth profiles of the as received double coated fiber revealed concentration oscillations which disappeared after annealing the fiber in the environment used to fabricate the composite. After the composite was fractured, the Auger depth profiles showed that failure occurred in neither the Beta-SiC fiber body nor in the Si3N4 matrix but, concurrently, at the fiber coating/matrix interface and within the fiber coating itself.

Honecy, Frank S.; Pepper, Stephen V.

1988-01-01

258

Modulating drug release and matrix erosion of alginate matrix capsules by microenvironmental interaction with calcium ion.  

PubMed

Effect of calcium gluconate (CG) content on release of dextromethorphan hydrobromide (DMP), model drug, from capsules containing low and medium viscosity grades of sodium alginate (SA) was investigated in different dissolution media. Matrix erosion of the SA matrix capsules in distilled water and pH 7.4 phosphate buffer was compared. Molecular interaction of SA with calcium ion in surface gel layer of the SA matrix capsules was examined using Fourier transform infrared spectroscopy and differential scanning calorimetry. In distilled water and pH 7.4 phosphate buffer, DMP release rate depended on the viscosity grade of SA, whereas a comparable DMP release rate was found in 0.1N HCl. Incorporation of CG into the SA matrix capsules caused a faster drug release in acidic medium because CG acted as a channeling agent in the hydrated insoluble gel matrix of alginic acid. Interaction of calcium ions with carboxyl groups of SA could be formed in surface gel layer of hydrated matrix capsules in distilled water. This led to a more rigid matrix gel structure that caused a slower drug release and matrix erosion. In contrast, the extent of this interaction in pH 7.4 phosphate buffer was less than that in distilled water because the common ion effect and high concentration of sodium ion retarded the hydration of SA and the binding of calcium ions with carboxyl groups of SA. Thus, a small change in drug release and matrix erosion was observed. This finding suggests that microenvironmental interaction between hydrated SA and calcium ion in distilled water could be created in the formulations prepared using low compression force. Moreover, incorporation of CG could moderate drug release and matrix erosion of the SA matrix capsules. PMID:17270407

Pongjanyakul, Thaned; Puttipipatkhachorn, Satit

2007-08-01

259

Thermal shock resistance of ceramic matrix composites  

NASA Technical Reports Server (NTRS)

The experimental and analytical investigation of the thermal shock phenomena in ceramic matrix composites is detailed. The composite systems examined were oxide-based, consisting of an aluminosilicate matrix with either polycrystalline aluminosilicate or single crystal alumina fiber reinforcement. The program was divided into three technical tasks; baseline mechanical properties, thermal shock modeling, and thermal shock testing. The analytical investigation focused on the development of simple expressions for transient thermal stresses induced during thermal shock. The effect of various material parameters, including thermal conductivity, elastic modulus, and thermal expansion, were examined analytically for their effect on thermal shock performance. Using a simple maximum stress criteria for each constituent, it was observed that fiber fracture would occur only at the most extreme thermal shock conditions and that matrix fracture, splitting parallel to the reinforcing fiber, was to be expected for most practical cases. Thermal shock resistance for the two material systems was determined experimentally by subjecting plates to sudden changes in temperature on one surface while maintaining the opposite surface at a constant temperature. This temperature change was varied in severity (magnitude) and in number of shocks applied to a given sample. The results showed that for the most severe conditions examined that only surface matrix fracture was present with no observable fiber fracture. The impact of this damage on material performance was limited to the matrix dominated properties only. Specifically, compression strength was observed to decrease by as much as 50 percent from the measured baseline.

Carper, D. M.; Nied, H. F.

1993-01-01

260

Google matrix analysis of DNA sequences  

E-print Network

For DNA sequences of various species we construct the Google matrix G of Markov transitions between nearby words composed of several letters. The statistical distribution of matrix elements of this matrix is shown to be described by a power law with the exponent being close to those of outgoing links in such scale-free networks as the World Wide Web (WWW). At the same time the sum of ingoing matrix elements is characterized by the exponent being significantly larger than those typical for WWW networks. This results in a slow algebraic decay of the PageRank probability determined by the distribution of ingoing elements. The spectrum of G is characterized by a large gap leading to a rapid relaxation process on the DNA sequence networks. We introduce the PageRank proximity correlator between different species which determines their statistical similarity from the view point of Markov chains. The properties of other eigenstates of the Google matrix are also discussed. Our results establish scale-free features of ...

Kandiah, Vivek

2013-01-01

261

Spark plasma sintering of aluminum matrix composites  

NASA Astrophysics Data System (ADS)

Aluminum matrix composites make a distinct category of advanced engineering materials having superior properties over conventional aluminum alloys. Aluminum matrix composites exhibit high hardness, yield strength, and excellent wear and corrosion resistance. Due to these attractive properties, aluminum matrix composites materials have many structural applications in the automotive and the aerospace industries. In this thesis, efforts are made to process high strength aluminum matrix composites which can be useful in the applications of light weight and strong materials. Spark Plasma Sintering (SPS) is a relatively novel process where powder mixture is consolidated under the simultaneous influence of uniaxial pressure and pulsed direct current. In this work, SPS was used to process aluminum matrix composites having three different reinforcements: multi-wall carbon nanotubes (MWCNTs), silicon carbide (SiC), and iron-based metallic glass (MG). In Al-CNT composites, significant improvement in micro-hardness, nano-hardness, and compressive yield strength was observed. The Al-CNT composites further exhibited improved wear resistance and lower friction coefficient due to strengthening and self-lubricating effects of CNTs. In Al-SiC and Al-MG composites, microstructure, densification, and tribological behaviors were also studied. Reinforcing MG and SiC also resulted in increase in micro-hardness and wear resistance.

Yadav, Vineet

262

Thermal stress effects in intermetallic matrix composites  

NASA Technical Reports Server (NTRS)

Intermetallic matrix composites develop residual stresses from the large thermal expansion mismatch (delta-alpha) between the fibers and matrix. This work was undertaken to: establish improved techniques to measure these thermal stresses in IMC's; determine residual stresses in a variety of IMC systems by experiments and modeling; and, determine the effect of residual stresses on selected mechanical properties of an IMC. X ray diffraction (XRD), neutron diffraction (ND), synchrotron XRD (SXRD), and ultrasonics (US) techniques for measuring thermal stresses in IMC were examined and ND was selected as the most promising technique. ND was demonstrated on a variety of IMC systems encompassing Ti- and Ni-base matrices, SiC, W, and Al2O3 fibers, and different fiber fractions (Vf). Experimental results on these systems agreed with predictions of a concentric cylinder model. In SiC/Ti-base systems, little yielding was found and stresses were controlled primarily by delta-alpha and Vf. In Ni-base matrix systems, yield strength of the matrix and Vf controlled stress levels. The longitudinal residual stresses in SCS-6/Ti-24Al-llNb composite were modified by thermomechanical processing. Increasing residual stress decreased ultimate tensile strength in agreement with model predictions. Fiber pushout strength showed an unexpected inverse correlation with residual stress. In-plane shear yield strength showed no dependence on residual stress. Higher levels of residual tension led to higher fatigue crack growth rates, as suggested by matrix mean stress effects.

Wright, P. K.; Sensmeier, M. D.; Kupperman, D. S.; Wadley, H. N. G.

1993-01-01

263

A New Algorithm for the Nearest Singular Toeplitz Matrix to a Given Toeplitz Matrix  

E-print Network

parameters can be computed from the data by computing the null vector of a Hermitian Toeplitz matrix with (m that operates directly on the data, rather than on the autocorrelation, is desirable. TLS Prony method is an example of this. However, TLS Prony uses the TLS solution (minimum singular vec- tor of the matrix), which

Yagle, Andrew E.

264

Numerical study on optimal Stirling engine regenerator matrix designs taking into account the effects of matrix  

E-print Network

Numerical study on optimal Stirling engine regenerator matrix designs taking into account matrix design that improves the efficiency of a Stirling engine has been developed in a numerical study of the existing SM5 Stirling engine. A new, detailed, one-dimensional Stirling engine model that delivers results

265

Quaternion from rotation matrix. [four-parameter representation of coordinate transformation matrix  

NASA Technical Reports Server (NTRS)

A quaternion is regarded as a four-parameter representation of a coordinate transformation matrix, where the four components of the quaternion are treated on an equal basis. This leads to a unified, compact, and singularity-free approach to determining the quaternion when the matrix is given.

Shepperd, S. W.

1978-01-01

266

Understanding the efficiency of GPU algorithms for matrix-matrix multiplication  

Microsoft Academic Search

Utilizing graphics hardware for general purpose numerical computations has become a topic of considerable interest. The implementation of streaming algorithms, typified by highly parallel computations with little reuse of input data, has been widely explored on GPUs. We relax the streaming model's constraint on input reuse and perform an in-depth analysis of dense matrix-matrix multiplication, which reuses each element of

Kayvon Fatahalian; Jeremy Sugerman; Pat Hanrahan

2004-01-01

267

Cell-matrix adhesion in vascular development: Cell-matrix adhesion in vascular development  

Microsoft Academic Search

Summary. Vascular development requires correct interactions among endothelial cells, pericytes and surrounding cells. These interactions involve many cell adhesion interactions, including cell-matrix interactions both with basement membranes and with surrounding extracellular matrices. Investigations of the contributions of these various interactions in vascular develop- mentandangiogenesishavebeenratherunevenandincomplete over the past 10-15 years. There has been considerable concentration on a few receptors, matrix proteins

R. O. HYNES

2007-01-01

268

Superbosonization of Invariant Random Matrix Ensembles  

NASA Astrophysics Data System (ADS)

‘Superbosonization’ is a new variant of the method of commuting and anti-commuting variables as used in studying random matrix models of disordered and chaotic quantum systems. We here give a concise mathematical exposition of the key formulas of superbosonization. Conceived by analogy with the bosonization technique for Dirac fermions, the new method differs from the traditional one in that the superbosonization field is dual to the usual Hubbard-Stratonovich field. The present paper addresses invariant random matrix ensembles with symmetry group U n , O n , or USp n , giving precise definitions and conditions of validity in each case. The method is illustrated at the example of Wegner’s n-orbital model. Superbosonization promises to become a powerful tool for investigating the universality of spectral correlation functions for a broad class of random matrix ensembles of non-Gaussian and/or non-invariant type.

Littelmann, P.; Sommers, H.-J.; Zirnbauer, M. R.

2008-10-01

269

Superbosonization of invariant random matrix ensembles  

E-print Network

Superbosonization is a new variant of the method of commuting and anti-commuting variables as used in studying random matrix models of disordered and chaotic quantum systems. We here give a concise mathematical exposition of the key formulas of superbosonization. Conceived by analogy with the bosonization technique for Dirac fermions, the new method differs from the traditional one in that the superbosonization field is dual to the usual Hubbard-Stratonovich field. The present paper addresses invariant random matrix ensembles with symmetry group U(n), O(n), or USp(n), giving precise definitions and conditions of validity in each case. The method is illustrated at the example of Wegner's n-orbital model. Superbosonization promises to become a powerful tool for investigating the universality of spectral correlation functions for a broad class of random matrix ensembles of non-Gaussian and/or non-invariant type.

Littelmann, P; Zirnbauer, M R

2007-01-01

270

Superbosonization of invariant random matrix ensembles  

E-print Network

Superbosonization is a new variant of the method of commuting and anti-commuting variables as used in studying random matrix models of disordered and chaotic quantum systems. We here give a concise mathematical exposition of the key formulas of superbosonization. Conceived by analogy with the bosonization technique for Dirac fermions, the new method differs from the traditional one in that the superbosonization field is dual to the usual Hubbard-Stratonovich field. The present paper addresses invariant random matrix ensembles with symmetry group U(n), O(n), or USp(n), giving precise definitions and conditions of validity in each case. The method is illustrated at the example of Wegner's n-orbital model. Superbosonization promises to become a powerful tool for investigating the universality of spectral correlation functions for a broad class of random matrix ensembles of non-Gaussian and/or non-invariant type.

P. Littelmann; H. -J. Sommers; M. R. Zirnbauer

2007-07-19

271

Variational regularized 2-D nonnegative matrix factorization.  

PubMed

A novel approach for adaptive regularization of 2-D nonnegative matrix factorization is presented. The proposed matrix factorization is developed under the framework of maximum a posteriori probability and is adaptively fine-tuned using the variational approach. The method enables: (1) a generalized criterion for variable sparseness to be imposed onto the solution; and (2) prior information to be explicitly incorporated into the basis features. The method is computationally efficient and has been demonstrated on two applications, that is, extracting features from image and separating single channel source mixture. In addition, it is shown that the basis features of an information-bearing matrix can be extracted more efficiently using the proposed regularized priors. Experimental tests have been rigorously conducted to verify the efficacy of the proposed method. PMID:24806120

Gao, Bin; Woo, W L; Dlay, S S

2012-05-01

272

Using Underapproximations for Sparse Nonnegative Matrix Factorization  

E-print Network

Nonnegative Matrix Factorization (NMF) has gathered a lot of attention in the last decade and has been successfully applied in numerous applications. It consists in the factorization of a nonnegative matrix by the product of two low-rank nonnegative matrices: $M \\approx VW$. In this paper, we attempt to solve NMF problems in a recursive way. In order to do that, we introduce a new variant called Nonnegative Matrix Underapproximation (NMU) by adding the upper bound constraint $VW \\leq M$. Besides enabling a recursive procedure for NMF, these inequalities make NMU particularly well-suited to achieve a sparse representation, improving the part-based decomposition. Although NMU is NP-hard (which we prove using its equivalence with the maximum edge biclique problem in bipartite graphs), we present two approaches to solve it: a method based on convex reformulations and a method based on Lagrangian relaxation. Finally, we provide some encouraging numerical results for image processing applications.

Gillis, Nicolas

2009-01-01

273

Matrix metalloproteinases in destructive pulmonary pathology  

PubMed Central

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that have a number of important physiological roles including remodelling of the extracellular matrix, facilitating cell migration, cleaving cytokines, and activating defensins. However, excess MMP activity may lead to tissue destruction. The biology of MMP and the role of these proteases in normal pulmonary immunity are reviewed, and evidence that implicates excess MMP activity in causing matrix breakdown in chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), sarcoidosis, and tuberculosis is discussed. Evidence from both clinical studies and animal models showing that stromal and inflammatory cell MMP expression leads to immunopathology is examined, and the mechanisms by which excess MMP activity may be targeted to improve clinical outcomes are discussed. PMID:16227332

Elkington, P T G; Friedland, J S

2006-01-01

274

Matrix metalloproteinases in destructive pulmonary pathology.  

PubMed

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that have a number of important physiological roles including remodelling of the extracellular matrix, facilitating cell migration, cleaving cytokines, and activating defensins. However, excess MMP activity may lead to tissue destruction. The biology of MMP and the role of these proteases in normal pulmonary immunity are reviewed, and evidence that implicates excess MMP activity in causing matrix breakdown in chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), sarcoidosis, and tuberculosis is discussed. Evidence from both clinical studies and animal models showing that stromal and inflammatory cell MMP expression leads to immunopathology is examined, and the mechanisms by which excess MMP activity may be targeted to improve clinical outcomes are discussed. PMID:16227332

Elkington, P T G; Friedland, J S

2006-03-01

275

Ethynylated aromatics as high temperature matrix resins  

NASA Technical Reports Server (NTRS)

Difunctional and trifunctional arylacetylenes were used as monomers to form thermoset matrix resin composites. Composites can be hot pressed at 180 C to react 80 percent of the acetylene groups. Crosslinking is completed by postcuring at 350 C. The postcured resins are thermally stable to nominally 460 C in air. As a result of their high crosslink density, the matrix exhibits brittle failure when unaxial composites are tested in tension. Failure of both uniaxial tensile and flexural specimens occurs in shear at the fiber matrix interface. Tensile fracture stresses for 0 deg composites fabricated with 60 v/o Celion 6K graphite fiber were 827 MPa. The strain to failure was 0.5 percent. Composites fabricated with 8 harness satin Celion cloth (Fiberite 1133) and tested in tension also failed in shear at tensile stresses of 413 MPa.

Hurwitz, Frances I.

1986-01-01

276

Space Shuttle communications RF switch matrix  

NASA Technical Reports Server (NTRS)

The Shuttle Orbiter communications equipment includes phase modulation (PM) and frequency modulation (FM) channels. The PM section has the capability of routing high levels of energy (175 W) from any one of four transmitters to any one of four antennas, mutually exclusive. The FM channel uses a maximum of 15-W power routed from either of two transmitters to one of two antennas, mutually exclusive. The paper describes the design and the theory of a logic-controlled RF switch matrix devised for the purposes cited. Both PM and FM channels are computer-controlled with manual overrides. The logic interface is realized with CMOS logic for low power consumption and high noise immunity. The interior of the switch matrix is maintained at a pressure of 15 psi (90% nitrogen, 10% helium) by an electron beam-welded encapsulation. The computational results confirm the viability of the RF switch matrix concept.

Winch, R.

1979-01-01

277

Google matrix analysis of directed networks  

E-print Network

In past ten years, modern societies developed enormous communication and social networks. Their classification and information retrieval processing become a formidable task for the society. Due to the rapid growth of World Wide Web, social and communication networks, new mathematical methods have been invented to characterize the properties of these networks on a more detailed and precise level. Various search engines are essentially using such methods. It is highly important to develop new tools to classify and rank enormous amount of network information in a way adapted to internal network structures and characteristics. This review describes the Google matrix analysis of directed complex networks demonstrating its efficiency on various examples including World Wide Web, Wikipedia, software architecture, world trade, social and citation networks, brain neural networks, DNA sequences and Ulam networks. The analytical and numerical matrix methods used in this analysis originate from the fields of Markov chains, quantum chaos and Random Matrix theory.

Leonardo Ermann; Klaus M. Frahm; Dima L. Shepelyansky

2014-09-01

278

Improved high temperature resistant matrix resins  

NASA Technical Reports Server (NTRS)

The objective was to develop organic matrix resins suitable for service at temperatures up to 644 K (700 F) and at air pressures up to 0.4 MPa (60 psia) for time durations of a minimum of 100 hours. Matrix resins capable of withstanding these extreme oxidative environmental conditions would lead to increased use of polymer matrix composites in aircraft engines and provide significant weight and cost savings. Six linear condensation, aromatic/heterocyclic polymers containing fluorinated and/or diphenyl linkages were synthesized. The thermo-oxidative stability of the resins was determined at 644 K and compressed air pressures up to 0.4 MPa. Two formulations, both containing perfluoroisopropylidene linkages in the polymer backbone structure, exhibited potential for 644 K service to meet the program objectives. Two other formulations could not be fabricated into compression molded zero defect specimens.

Chang, G. E.; Powell, S. H.; Jones, R. J.

1983-01-01

279

Statistical properties of random matrix product states  

SciTech Connect

We study the set of random matrix product states (RMPS) introduced by Garnerone, de Oliveira, and Zanardi [S. Garnerone, T. R. de Oliveira, and P. Zanardi, Phys. Rev. A 81, 032336 (2010)] as a tool to explore foundational aspects of quantum statistical mechanics. In the present work, we provide an accurate numerical and analytical investigation of the properties of RMPS. We calculate the average state of the ensemble in the nonhomogeneous case, and numerically check the validity of this result. We also suggest using RMPS as a tool to approximate properties of general quantum random states. The numerical simulations presented here support the accuracy and efficiency of this approximation. These results suggest that any generalized canonical state can be approximated with high probability by the reduced density matrix of a RMPS, if the average matrix product states coincide with the associated microcanonical ensemble.

Garnerone, Silvano; Oliveira, Thiago R. de; Haas, Stephan; Zanardi, Paolo [Department of Physics and Astronomy and Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, California 90089 (United States)

2010-11-15

280

Nanomechanics of the Cartilage Extracellular Matrix  

NASA Astrophysics Data System (ADS)

Cartilage is a hydrated biomacromolecular fiber composite located at the ends of long bones that enables proper joint lubrication, articulation, loading, and energy dissipation. Degradation of extracellular matrix molecular components and changes in their nanoscale structure greatly influence the macroscale behavior of the tissue and result in dysfunction with age, injury, and diseases such as osteoarthritis. Here, the application of the field of nanomechanics to cartilage is reviewed. Nanomechanics involves the measurement and prediction of nanoscale forces and displacements, intra- and intermolecular interactions, spatially varying mechanical properties, and other mechanical phenomena existing at small length scales. Experimental nanomechanics and theoretical nanomechanics have been applied to cartilage at varying levels of material complexity, e.g., nanoscale properties of intact tissue, the matrix associated with single cells, biomimetic molecular assemblies, and individual extracellular matrix biomolecules (such as aggrecan, collagen, and hyaluronan). These studies have contributed to establishing a fundamental mechanism-based understanding of native and engineered cartilage tissue function, quality, and pathology.

Han, Lin; Grodzinsky, Alan J.; Ortiz, Christine

2011-08-01

281

Electrolyte matrix for molten carbonate fuel cells  

DOEpatents

A matrix for a carbonate electrolyte including a support material and an additive constituent having a relatively low melting temperature and a relatively high coefficient of thermal expansion. The additive constituent is from 3 to 45 weight percent of the matrix and is formed from raw particles whose diameter is in a range of 0.1 .mu.m to 20 .mu.m and whose aspect ratio is in a range of 1 to 50. High energy intensive milling is used to mix the support material and additive constituent during matrix formation. Also disclosed is the use of a further additive constituent comprising an alkaline earth containing material. The further additive is mixed with the support material using high energy intensive milling.

Huang, Chao M. (Danbury, CT); Yuh, Chao-Yi (New Milford, CT)

1999-01-01

282

Introducing Matrix Operations through Biological Applications  

NSDL National Science Digital Library

For the Blue Waters Undergraduate Petascale Education Program (NSF), we developed a computational science module, "Living Links: Applications of Matrix Operations to Population Studies," which introduces matrix operations using applications to population studies and provides accompanying programs in a variety of systems (C/MPI, MATLAB, Mathematica). The module provides a foundation for the use of matrix operations that are essential to modeling numerous computational science applications from population studies to social networks. This paper describes the module; details experiences using the material in two undergraduate courses (High Performance Computing and Linear Algebra) in 2010 and 2011 at Wofford College and two workshops for Ph.D. students at Monash University in Melbourne, Australia, in 2011; and describes refinements to the module based on suggestions in student and instructor evaluations.

Shiflet, Angela B.; Shiflet, George W.

283

On Matrix Geometry and Effective Actions  

E-print Network

We provide an elementary systematic discussion of single-trace matrix actions and of the group of matrix reparameterization that acts on them. The action of this group yields a generalized notion of gauge invariance which encompasses ordinary diffeomorphism and gauge invariances. We apply the formalism to non-abelian D-brane actions in arbitrary supergravity backgrounds, providing in particular explicit checks of the consistency of Myers' formulas with supergravity gauge invariances. We also draw interesting consequences for emergent space models based on the study of matrix effective actions. For example, in the case of the AdS_5XS^5 background, we explain how the standard tensor transformation laws of the supergravity fields under ordinary diffeomorphisms emerge from the D-instanton effective action in this background.

Frank Ferrari

2013-01-16

284

DNA size separation using artificially nanostructured matrix  

NASA Astrophysics Data System (ADS)

We have demonstrated two types of size separation of biomolecules using a nanostructured matrix artificially fabricated using electron-beam lithography: sieve-type separation using a regular pillar array structure and size exclusion chromatography (SEC) type separation using a structure with narrow and wide gaps. With these devices, samples of double-stranded DNA molecules (2, 5, and 10 k base pairs) were clearly separated into bands; smaller molecules eluted earlier in the sieve type while they eluted later in the SEC type. The nanostructured matrix enables various types of molecular separation by changing the design of the nanostructure. Moreover, it should be easy to integrate the matrix with other biomolecular fluidic devices because it does not require a filling medium.

Baba, M.; Sano, T.; Iguchi, N.; Iida, K.; Sakamoto, T.; Kawaura, H.

2003-08-01

285

Decorin modulates matrix mineralization in vitro  

NASA Technical Reports Server (NTRS)

Decorin (DCN), a member of small leucine-rich proteoglycans, is known to modulate collagen fibrillogenesis. In order to investigate the potential roles of DCN in collagen matrix mineralization, several stable osteoblastic cell clones expressing higher (sense-DCN, S-DCN) and lower (antisense-DCN, As-DCN) levels of DCN were generated and the mineralized nodules formed by these clones were characterized. In comparison with control cells, the onset of mineralization by S-DCN clones was significantly delayed; whereas it was markedly accelerated and the number of mineralized nodules was significantly increased in As-DCN clones. The timing of mineralization was inversely correlated with the level of DCN synthesis. In these clones, the patterns of cell proliferation and differentiation appeared unaffected. These results suggest that DCN may act as an inhibitor of collagen matrix mineralization, thus modulating the timing of matrix mineralization.

Mochida, Yoshiyuki; Duarte, Wagner R.; Tanzawa, Hideki; Paschalis, Eleftherios P.; Yamauchi, Mitsuo

2003-01-01

286

Enter the Matrix: Shape, Signal, and Superhighway  

PubMed Central

Mammalian skeletal muscle is notable for both its highly ordered biophysical structure and its regenerative capacity following trauma. Critical to both of these features is the specialized muscle extracellular matrix (ECM), comprising both the multiple concentric sheaths of connective tissue surrounding structural units from single myofibers to whole muscles and the dense interstitial matrix that occupies the space between them. ECM-dependent interactions affect all activities of the resident muscle stem cell population, the satellite cell, from the maintenance of quiescence and stem cell potential to the regulation of proliferation and differentiation. This review will focus on the role of the extracellular matrix in muscle regeneration, with a particular emphasis on regulation of satellite cell activity. PMID:23374506

Lund, Dane K.; Cornelison, DDW

2013-01-01

287

Thermal and mechanical behavior of metal matrix and ceramic matrix composites  

NASA Technical Reports Server (NTRS)

The present conference discusses local stresses in metal-matrix composites (MMCs) subjected to thermal and mechanical loads, the computational simulation of high-temperature MMCs' cyclic behavior, an analysis of a ceramic-matrix composite (CMC) flexure specimen, and a plasticity analysis of fibrous composite laminates under thermomechanical loads. Also discussed are a comparison of methods for determining the fiber-matrix interface frictional stresses of CMCs, the monotonic and cyclic behavior of an SiC/calcium aluminosilicate CMC, the mechanical and thermal properties of an SiC particle-reinforced Al alloy MMC, the temperature-dependent tensile and shear response of a graphite-reinforced 6061 Al-alloy MMC, the fiber/matrix interface bonding strength of MMCs, and fatigue crack growth in an Al2O3 short fiber-reinforced Al-2Mg matrix MMC.

Kennedy, John M. (editor); Moeller, Helen H. (editor); Johnson, W. S. (editor)

1990-01-01

288

Generating Nice Linear Systems for Matrix Gaussian Elimination  

ERIC Educational Resources Information Center

In this article an augmented matrix that represents a system of linear equations is called nice if a sequence of elementary row operations that reduces the matrix to row-echelon form, through matrix Gaussian elimination, does so by restricting all entries to integers in every step. Many instructors wish to use the example of matrix Gaussian…

Homewood, L. James

2004-01-01

289

The biofilm matrix – an immobilized but dynamic microbial environment  

Microsoft Academic Search

The biofilm matrix is a dynamic environment in which the component microbial cells appear to reach homeostasis and are optimally organized to make use of all available nutrients. The major matrix components are microbial cells, polysaccharides and water, together with excreted cellular products. The matrix therefore shows great microheterogeneity, within which numerous microenvironments can exist. Although exopolysaccharides provide the matrix

Ian W Sutherland

2001-01-01

290

Indeterminacy Criteria for the Stieltjes Matrix Moment Problem  

Microsoft Academic Search

In this paper, we obtain criteria for the indeterminacy of the Stieltjes matrix moment problem. We obtain explicit formulas for Stieltjes parameters and study the multiplicative structure of the resolvent matrix. In the indeterminate case, we study the analytic properties of the resolvent matrix of the moment problem. We describe the set of all matrix functions associated with the indeterminate

Yu. M. Dyukarev

2004-01-01

291

The Matrix Template Library: A Generic Programming Approach  

E-print Network

generation system [16]. To make matters worse, the performance of codes such as matrix­matrix multiply codes. The Matrix Template Library [11] is in its second generation, and has been com­ pletely rewrittenThe Matrix Template Library: A Generic Programming Approach to High Performance Numerical Linear

Lumsdaine, Andrew

292

The Matrix Template Library: A Generic Programming Approach  

E-print Network

generation system [16]. To make matters worse, the performance of codes such as matrix-matrix multiply codes. The Matrix Template Library [11] is in its second generation, and has been com- pletely rewrittenThe Matrix Template Library: A Generic Programming Approach to High Performance Numerical Linear

Lumsdaine, Andrew

293

Efficient ordering algorithms for sparse matrix\\/vector methods  

Microsoft Academic Search

This paper introduces four node ordering algorithms that can be used to improve the efficiency of the sparse matrix and spare vector methods. The algorithms are based on the diagonalization of theA matrix via the use of the C transformation matrix while minimizing the fill-in elements in C. The node ordering sequence and the C matrix are generated in a

H. B. Gooi; Y. Q. Wang

1998-01-01

294

The pairing matrix in discrete electromagnetism  

NASA Astrophysics Data System (ADS)

We introduce pairing matrices on simplicial cell complexes in discrete electromagnetism as a means to avoid the explicit construction of a topologically dual complex. Interestingly, the Finite Element Method with first-order Whitney elements — when it is looked upon from a cell-method perspective — features pairing matrices and thus an implicitly defined dual mesh. We show that the pairing matrix can be used to construct discrete energy products. In this exercise we find that different formalisms lead to equivalent matrix representations. Discrete de Rham currents are an elegant way to subsume these geometrically equivalent but formally distinct ways of defining energy-products.

Auchmann, B.; Kurz, S.

2007-08-01

295

Stability of matrix equations arising in electromagnetics  

NASA Technical Reports Server (NTRS)

Many problems in electromagnetics can be formulated as a Fredholm equation of the first kind. In these problems it is desired to determine some function f(x) from its integral transform g(y). Except for special cases for which an explicit inverse operator is known, the equation is usually discretized by the method of moments into a matrix equation Af = g, which is then solved on a computer. A method of calculating the sensitivity of the solution of Af = g due to errors in either the vector g or the matrix A is developed. The usefulness of this method is demonstrated with problems from antenna theory, scattering theory, and remote sensing.

Klein, C.; Mittra, R.

1973-01-01

296

Noncommutative static strings from matrix models  

NASA Astrophysics Data System (ADS)

We examine the noncommutative cylinder solution to a matrix model with a Minkowski background metric. It can be regarded as the noncommutative analogue of a static circular string. Perturbations about the solution yield a tachyonic scalar field (and an additional tachyonic fermion in the full supersymmetric version of the model) in the commutative limit. The tachyonic mode is attributed to the fact that the circular string is unstable under uniform adiabatic deformations. We obtain a stabilizing term which, when added to the matrix model, removes the tachyonic mass.

Stern, A.

2014-05-01

297

Corporate bond liquidity and matrix pricing  

NASA Astrophysics Data System (ADS)

Matrix priced bond price data are investigated to model the liquidity of a corporate bond. Preliminary study shows that the yield spread is wide when a yield history records jumps. As well as respecting the way how matrix prices are generated, this finding leads us to a conjecture that time series of yield is represented by a jump-diffusion process. Then the kurtosis of a yield distribution can be regarded as a proxy variable for the liquidity. The conjecture is empirically validiated by regression analysis of yield spreads.

Kagraoka, Yusho

2005-09-01

298

Analytical solutions to matrix diffusion problems  

NASA Astrophysics Data System (ADS)

We report an analytical method to solve in a few cases of practical interest the equations which have traditionally been proposed for the matrix diffusion problem. In matrix diffusion, elements dissolved in ground water can penetrate the porous rock surronding the advective flow paths. In the context of radioactive waste repositories this phenomenon provides a mechenism by which the area of rock surface in contact with advecting elements is greatly enhaced, and can thus be an important delay mechanism. The cases solved are relevant for laborary as well for in situ experiments. Solutions are given as integral representations well suited for easy numerical solution.

Kekäläinen, Pekka

2014-10-01

299

Algebraic Geometry of Matrix Product States  

NASA Astrophysics Data System (ADS)

We quantify the representational power of matrix product states (MPS) for entangled qubit systems by giving polynomial expressions in a pure quantum state's amplitudes which hold if and only if the state is a translation invariant matrix product state or a limit of such states. For systems with few qubits, we give these equations explicitly, considering both periodic and open boundary conditions. Using the classical theory of trace varieties and trace algebras, we explain the relationship between MPS and hidden Markov models and exploit this relationship to derive useful parameterizations of MPS. We make four conjectures on the identifiability of MPS parameters.

Critch, Andrew; Morton, Jason

2014-09-01

300

General Polarization Matrix of Electromagnetic Radiation  

E-print Network

A general form of the polarization matrix valid for any type of electromagnetic radiation (plane waves, multipole radiation etc.) is defined in terms of a certain bilinear form in the field-strength tensor. The quantum counterpart is determined as an operator matrix with normal-ordered elements with respect to the creation and annihilation operators. The zero-point oscillations (ZPO) of polarization are defined via difference between the anti-normal and normal ordered operator polarization matrices. It is shown that ZPO of the multipole field are stronger than those described by the model of plane waves and are concentrated in a certain neighborhood of a local source.

Muhammet Ali Can; Alexander S. Shumovsky

2001-05-15

301

Matrix Metalloproteinases: Regulators of the Tumor Microenvironment  

PubMed Central

Extracellular proteolysis mediates tissue homeostasis. In cancer, altered proteolysis leads to unregulated tumor growth, tissue remodeling, inflammation, tissue invasion, and metastasis. The matrix metalloproteinases (MMPs) represent the most prominent family of proteinases associated with tumorigenesis. Recent technological developments have markedly advanced our understanding of MMPs as modulators of the tumor microenvironment. In addition to their role in extracellular matrix turnover and cancer cell migration, MMPs regulate signaling pathways that control cell growth, inflammation, or angiogenesis and may even work in a nonproteolytic manner. These aspects of MMP function are reorienting our approaches to cancer therapy. PMID:20371345

Kessenbrock, Kai; Plaks, Vicki; Werb, Zena

2010-01-01

302

Glueball Matrix Elements on Anisotropic Lattices  

SciTech Connect

The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing in the range 0.1fm-0.2fm. These matrix elements are needed to predict the glueball branching ratios in J/{psi} radiative decays which will help to identify the glueball states in experiments. Two types of improved local gluonic operators are constructed for a self-consistent check, and the finite volume effects are also studied. The lattice spacing dependence of our results is very small and the continuum limits are reliably extrapolated.

Y. Chen; S.-J. Dong; T. Draper; I. Horvath; F.-X. Lee; N. Mathur; C. Morningstar; M. Peardon; S. Tamhankar; B.L. Young; J.-B. Zhang

2004-03-01

303

Matrix diffusion coefficients in volcanic rocks at the Nevada test site: Influence of matrix porosity, matrix permeability, and fracture coating minerals  

NASA Astrophysics Data System (ADS)

Diffusion cell experiments were conducted to measure nonsorbing solute matrix diffusion coefficients in forty-seven different volcanic rock matrix samples from eight different locations (with multiple depth intervals represented at several locations) at the Nevada Test Site. The solutes used in the experiments included bromide, iodide, pentafluorobenzoate (PFBA), and tritiated water ( 3HHO). The porosity and saturated permeability of most of the diffusion cell samples were measured to evaluate the correlation of these two variables with tracer matrix diffusion coefficients divided by the free-water diffusion coefficient ( Dm/ D*). To investigate the influence of fracture coating minerals on matrix diffusion, ten of the diffusion cells represented paired samples from the same depth interval in which one sample contained a fracture surface with mineral coatings and the other sample consisted of only pure matrix. The log of ( Dm/ D*) was found to be positively correlated with both the matrix porosity and the log of matrix permeability. A multiple linear regression analysis indicated that both parameters contributed significantly to the regression at the 95% confidence level. However, the log of the matrix diffusion coefficient was more highly-correlated with the log of matrix permeability than with matrix porosity, which suggests that matrix diffusion coefficients, like matrix permeabilities, have a greater dependence on the interconnectedness of matrix porosity than on the matrix porosity itself. The regression equation for the volcanic rocks was found to provide satisfactory predictions of log( Dm/ D*) for other types of rocks with similar ranges of matrix porosity and permeability as the volcanic rocks, but it did a poorer job predicting log( Dm/ D*) for rocks with lower porosities and/or permeabilities. The presence of mineral coatings on fracture walls did not appear to have a significant effect on matrix diffusion in the ten paired diffusion cell experiments.

Reimus, Paul W.; Callahan, Timothy J.; Ware, S. Doug; Haga, Marc J.; Counce, Dale A.

2007-08-01

304

Matrix-Free Interior Point Method  

E-print Network

Oct 5, 2009 ... while [10] regularizes the Hessian matrix (what in our terms would correspond ...... path following algorithm in which the Newton search directions are com- ... element in DS is selected to be the next pivot to enter DL, then the ...

2009-10-07

305

Supermacroporous cryogel matrix for integrated protein isolation  

Microsoft Academic Search

A new type of supermacroporous, monolithic, cryogel affinity adsorbent was developed, allowing the specific capture of urokinase from conditioned media of human fibrosarcoma cell line HT1080. The affinity adsorbent was designed with the objective of using it as a capture column in an integrated perfusion\\/protein separation bioreactor setup. A comparative study between the utility of this novel cryogel based matrix

Ashok Kumar; Vibha Bansal; Jonatan Andersson; Pradip K. Roychoudhury; Bo Mattiasson

2006-01-01

306

Powder metal matrix composites: selection and processing  

Microsoft Academic Search

There has been growing interest in the last decade in the development of metal matrix composites (MMCs) for the aerospace industry because of their attractive physical and mechanical properties and enhanced elevated temperature capabilities. However, some of the fabrication techniques (e.g. using powder metallurgy) for this new class of MMCs are hampered by (i) the poor distribution of the reinforcements,

M. J Tan; X Zhang

1998-01-01

307

Fresnel diffraction of substructured gratings: matrix description  

NASA Astrophysics Data System (ADS)

We present a matrix formalism to describe the near-field diffraction pattern, at fractions of a Talbot distance, of a grating whose unit cell is composed of a discrete substructure. We show that this formalism is useful for designing Lohmann array illuminators.

Arrizón, Victor; Ojeda-Castañeda, J.

1995-01-01

308

Diverse functions of matrix metalloproteinases during fibrosis  

PubMed Central

ABSTRACT Fibrosis – a debilitating condition that can occur in most organs – is characterized by excess deposition of a collagen-rich extracellular matrix (ECM). At first sight, the activities of proteinases that can degrade matrix, such as matrix metalloproteinases (MMPs), might be expected to be under-expressed in fibrosis or, if present, could function to resolve the excess matrix. However, as we review here, some MMPs are indeed anti-fibrotic, whereas others can have pro-fibrotic functions. MMPs modulate a range of biological processes, especially processes related to immunity and tissue repair and/or remodeling. Although we do not yet know precisely how MMPs function during fibrosis – that is, the protein substrate or substrates that an individual MMP acts on to effect a specific process – experiments in mouse models demonstrate that MMP-dependent functions during fibrosis are not limited to effects on ECM turnover. Rather, data from diverse models indicate that these proteinases influence cellular activities as varied as proliferation and survival, gene expression, and multiple aspects of inflammation that, in turn, impact outcomes related to fibrosis. PMID:24713275

Giannandrea, Matthew; Parks, William C.

2014-01-01

309

Matrix Encoding For Correction Of Errors  

NASA Technical Reports Server (NTRS)

Method of matrix encoding and associated decoding provides for correction of errors in digital data recorded on magnetic tape. Intended specifically for use with commercial control circuit board and associated software making it possible to use video cassette recorder as backup for hard-disk memory of personal computer.

Dotson, Ronald S.

1991-01-01

310

A Random Matrix Model of Black Holes  

E-print Network

A random matrix model of black holes is given based on analysis of Gaussian complex ensembles, based on the generalization of chRMT of QCD. Spacetime freedoms are incorporated in terms of eigenvalues of the ensemble. Classical observables of black holes can be computed using this model and it satisfies asymptotic freedom and holographic principle.

Da Xu

2007-12-28

311

A matrix approach for assessing biosolids stability  

SciTech Connect

Stability assessment of biosolids must be made on the basis of the stabilization process used and the intended use of the manufactured biosolids. In this manner, a matrix based on technology and use was developed as an approach for assessing biosolids stability. Specific tests were recommended as to the most useful methods of stability assessment for each of the stabilization technologies examined.

Switzenbaum, M.S.; Moss, L.H.; Epstein, E.; Pincince, A.B.; Donovan, J.F.

1998-07-01

312

Reducing Symmetry in Matrix Models # Zeynep Kzltan  

E-print Network

Reducing Symmetry in Matrix Models # Zeynep K�z�ltan Department of Information Science, Uppsala played in a given week w and period p [12]. S Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Period 1 S scheduling problem, the weeks are indistin­ guishable, and so are the periods. A solution is thus symmetric

Rossi, Francesca

313

Evaluation of the Matrix Project. Interchange 77.  

ERIC Educational Resources Information Center

The Matrix Project is a program that has been established in central Scotland with the aim of reducing the risk of offending and anti-social behavior among vulnerable children. The project provides a range of services to children between eight and 11 years of age who are at risk in the local authority areas of Clackmannanshire, Falkirk and…

McIvor, Gill; Moodie, Kristina

314

Decision Matrix. NCEDL Spotlights, No. 8.  

ERIC Educational Resources Information Center

This report focuses on a decision-making model developed at the National Center for Early Development and Learning (NCEDL) and designed to help decisionmakers and policy analysts weigh various policy options for a public issue such as childcare quality. The matrix allows users to compare strategies in terms of desirability and feasibility factors…

National Center for Early Development & Learning, Chapel Hill, NC.

315

Discrete matrix Riccati equations with superposition formulas  

E-print Network

An ordinary differential equation is said to have a superposition formula if its general solution can be expressed as a function of a finite number of particular solution. Nonlinear ODE's with superposition formulas include matrix Riccati equations. Here we shall describe discretizations of Riccati equations that preserve the superposition formulas. The approach is general enough to include $q$-derivatives and standard discrete derivatives.

Alexei V. Penskoi; Pavel Winternitz

2003-05-25

316

Nonnegative Matrix Factorization: Models, Algorithms and Applications  

E-print Network

]). In fact, in many applications such as image processing, biology or text mining, nonnegative data analysis. In recent years, Nonnegative Matrix Factorization (NMF) has become a popular model in data mining society conclusions: 1) NMF has a good interpretability due to its nonnegative constraints; 2) NMF is very flexible

Allen, Jont

317

Are matrix metalloproteinases the missing link?  

Microsoft Academic Search

It is more and more evident that the matrix metalloproteinase (MMP) system is not a characteristic feature of vertebrate animals only, as it can also be found in many invertebrate organisms. This endopeptidase family has been widely studied since its first member was described 40 years ago during metamorphosis in tadpole tails. Many researches have been carried out in mammals

F Mannello; G Tonti; S Papa

2005-01-01

318

The strong matrix Stieltjes moment problem  

E-print Network

In this paper we study the strong matrix Stieltjes moment problem. We obtain necessary and sufficient conditions for its solvability. An analytic description of all solutions of the moment problem is derived. Necessary and sufficient conditions for the determinateness of the moment problem are given.

Rivero, A E Choque

2011-01-01

319

Matrix fraction descriptions in convolutional coding  

Microsoft Academic Search

In this paper, polynomial matrix fraction descriptions (MFDs) are used as a tool for investigating the structure of a (linear) convolutional code and the family of its encoders and syndrome formers. As static feedback and precompensation allow to obtain all minimal encoders (in particular, polynomial encoders and decoupled encoders) of a given code, a simple parametrization of their MFDs is

Ettore Fornasini; Raquel Pinto

2004-01-01

320

Nonnegative matrix factorization for polyphonic music transcription  

Microsoft Academic Search

We present a methodology for analyzing polyphonic musical passages comprised of notes that exhibit a harmonically fixed spectral profile (such as piano notes). Taking advantage of this unique note structure, we can model the audio content of the musical passage by a linear basis transform and use non-negative matrix decomposition methods to estimate the spectral profile and the temporal information

Paris Smaragdis; Judith C. Brown

2003-01-01

321

Parallel Programming with Matrix Distributed Processing  

E-print Network

Matrix Distributed Processing (MDP) is a C++ library for fast development of efficient parallel algorithms. It constitues the core of FermiQCD. MDP enables programmers to focus on algorithms, while parallelization is dealt with automatically and transparently. Here we present a brief overview of MDP and examples of applications in Computer Science (Cellular Automata), Engineering (PDE Solver) and Physics (Ising Model).

Massimo Di Pierro

2005-05-09

322

Avoiding communication in sparse matrix computations  

Microsoft Academic Search

The performance of sparse iterative solvers is typically limited by sparse matrix-vector multiplication, which is it- self limited by memory system and network performance. As the gap between computation and communication speed continues to widen, these traditional sparse methods will suffer. In this paper we focus on an alternative building block for sparse iterative solvers, the \\

James Demmel; Mark Hoemmen; Marghoob Mohiyuddin; Katherine A. Yelick

2008-01-01

323

Proteomic analysis of extracellular matrix and vesicles  

Microsoft Academic Search

The extracellular matrix (ECM) is the connective tissue component generated and secreted by cells to provide structural and functional support, while extracellular vesicles are distinct membrane-enclosed structures present outside of eucaryotic cells that carry out distinct biological functions. Different cell types release distinct populations of vesicles that fulfill various functions. Exosomes are vesicles commonly secreted by a variety of cells,

Zhen Xiao; Josip Blonder; Ming Zhou; Timothy D. Veenstra

2009-01-01

324

Biaffine matrix inequality properties and computational methods  

Microsoft Academic Search

Many robust control synthesis problems, including ?\\/km-synthesis, have been shown to be reducible to the problem of finding a feasible point under a biaffine matrix inequality (BMI) constraint. The paper discusses the related problem of minimizing the maximum eigenvalue of a biaffine combination of symmetric matrices, a biconvex, nonsmooth optimization problem. Various properties of the problem are examined and several

K. C. Goh; L. Turan; M. G. Safonov; G. P. Papavassilopoulos; J. H. Ly

1994-01-01

325

Nonspherical Giant Gravitons and Matrix Theory  

Microsoft Academic Search

We consider the plane wave limit of the nonspherical giant gravitons. We compute the Poisson brackets of the coordinate functions and find a nonlinear algebra. We show that this algebra solves the supersymmetry conditions of the matrix model. This is the generalization of the algebraic realization of the spherical membrane as the ``fuzzy sphere''. We describe finite dimensional representations of

Andrei Mikhailov

2002-01-01

326

Matrix mounting means for gas burners  

Microsoft Academic Search

Slyman Manufacturing Corp.'s modified infrared burner confines the heat to the surface of the burner (in order to protect the burner mounting from combustion) while maintaining infrared generation throughout the entire area of the burner face. The burner face comprises a matrix of fibrous refractory material positioned at the open side of a plenum through which the fuel is supplied

R. S. Bratko; W. Zwipf

1980-01-01

327

Critical State of Sand Matrix Soils  

PubMed Central

The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, ?, and ?. The range of the value of M, ?, and ? is 0.803–0.998, 0.144–0.248, and 1.727–2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated. PMID:24757417

Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

2014-01-01

328

Matrix Factorization as Search Kristian Kersting  

E-print Network

matrices. It was proven success- ful in game, social media, and plant mining. Here, we review the distance examples of objects include text documents, digital images, genomes, stocks, or social groups. Examples 2 where · denotes a suitable matrix norm, and one typically assumes k r. A common way of obtaining

Kaski, Samuel

329

Matrix models of discretely bending, stiff polymers  

Microsoft Academic Search

Polymer models which make use of the Ising model and transfer matrix techniques remind us, for example, of the work of Flory [Statistical mechanics of chain molecules, 1969] and Zimm and Bragg [J Chem Phys, 31 (1959) 526]. We investigate the properties of some such polymer models where the chain conformation can be described solely by an Ising-like parameterization and

Kristian K. Müller-Nedebock; Harry L. Frisch

2003-01-01

330

Matrix Metalloproteases in Aberrant Fibrotic Tissue Remodeling  

Microsoft Academic Search

Pulmonary fibrosis, the final result of a large variety of interstitial lung diseases, is characterized by an aberrant remodeling of extra- cellular matrix (ECM) with a profound disturbance of the normal lung architecture. This remodeling includes the exaggerated accu- mulation of ECM components in the interstitial and alveolar spaces and the disruption of the basement membranes. It has long been

Annie Pardo; Moises Selman

2006-01-01

331

["Archaic matrix of the oedipus complex"].  

PubMed

The clinical implication of Janine Chasseguet-Smirgel's concept of the "archaic matrix of the Oedipus complex" is examined, the resulting deeper understanding of the Oedipus myth is considered. A discussion follows of Chasseguet-Smirgel's way of using this concept in her historical evaluation of German Romantism with regard to the Nazi times and nowadays politics of the Westgerman Green Party. PMID:2251392

Vogt, R

1990-10-01

332

Illinois Early Childhood Program Expanded Matrix, 2001.  

ERIC Educational Resources Information Center

This matrix provides information on eight early childhood programs offered in Illinois. Presented in grid form, the information can be compared across programs. The programs described are: (1) Head Start and Early Head Start; (2) Illinois Department of Children and Family Services child care; (3) Illinois Department of Human Services child care;…

Illinois State Dept. of Human Services, East St. Louis. Head Start State Collaboration Office.

333

Hyperon Beta Decay and the CKM Matrix  

E-print Network

I shall present a pedagogical discussion of hyperon semileptonic decays, covering some of the historical background, the basics notions of hyperon semileptonic decays, deeply inelastic scattering and the CKM matrix, and the description of SU(2) and SU(3) breaking. I shall also present a prediction for a process under current experimental study.

Ratcliffe, P G

2004-01-01

334

Characterisation of stone matrix asphalt mixtures  

Microsoft Academic Search

This study applied conventional laboratory tests and advanced imaging techniques to experimentally verify the voids in coarse aggregate (VCA) method. Five stone matrix asphalt (SMA) mixtures designed to have different coarse aggregate skeletons were investigated to establish relationships between the VCA ratio, microstructure parameters and the mechanical response of SMA. X-ray CT and image analysis techniques were utilised to non-destructively

Laith Tashman; Brian Pearson

2012-01-01

335

Characterisation of stone matrix asphalt mixtures  

Microsoft Academic Search

This study applied conventional laboratory tests and advanced imaging techniques to experimentally verify the voids in coarse aggregate (VCA) method. Five stone matrix asphalt (SMA) mixtures designed to have different coarse aggregate skeletons were investigated to establish relationships between the VCA ratio, microstructure parameters and the mechanical response of SMA. X-ray CT and image analysis techniques were utilised to non-destructively

Laith Tashman; Brian Pearson

2011-01-01

336

History of extracellular matrix: A personal view  

Microsoft Academic Search

Before the early 1800s, the “fibers” of connective tissue were thought to be the basis of life, which arose by spontaneous generation. With the discovery of cells in connective tissue, the cellular theory became accepted as the basis of life in about 1850. Material outside cells, but presumably made by cells, was recognized as the extracellular matrix. In the period

Karl A. Piez

1997-01-01

337

The Drinking Matrix: A Symbolic Self Interaction  

Microsoft Academic Search

When our class began to get more in depth and interesting, I learned something about myself. Watching the movie The Matrix was extremely fascinating, but the discussion after the movie proved to me to be of more value. The concept “Know Thyself” almost exploded before my very ears. The movie brought up theories and ideas which never occurred to me.

Neo Morpheus

2003-01-01

338

Generalized Nonnegative Matrix Approximations with Bregman Divergences  

Microsoft Academic Search

Nonnegative matrix approximation (NNMA) is a recent technique for di- mensionality reduction and data analysis that yields a part s based, sparse nonnegative representation for nonnegative input data. NNMA has found a wide variety of applications, including text analysis, do cument cluster- ing, face\\/image recognition, language modeling, speech processing and many others. Despite these numerous applications, the algorithmic de- velopment

Inderjit S. Dhillon; Suvrit Sra

2005-01-01

339

Brain and CNS Multiple Primary Rules Matrix  

Cancer.gov

Malignant Meninges, Brain, Spinal Cord, Cranial Nerves, Pi tuitary gland, Craniopharyngeal duct and Pineal gland Multiple Primary Rules – Matrix C700, C701, C709, C710-C719, C720-C725, C728, C729, C751-C753 (Excludes lymphoma and leukemia – M9590-9989

340

Science Unlimited: Grades K-6 Competency Matrix.  

ERIC Educational Resources Information Center

This competency matrix matches the primary and intermediate Science Unlimited lessons with the established competencies which appear in the Science Unlimited competency continuum. Primary lessons deal with: investigating dripping faucets; classification/sorting; smell; eyes; color; air; weather; observation and description; mystery boxes; change;…

Pennsylvania State Dept. of Education, Harrisburg. Div. of Arts and Sciences.

341

Precise transfer matrix formulae considering axial forces  

Microsoft Academic Search

Two precise transfer matrix formulas of different forms for the analysis of shaft element with constant section parameters are derived, taking axial forces and shearing deformation into account. Both formulas are applied to a practical example. A comparison between calculation results and experimental data shows that the formulas are highly accurate and that considerable axial forces have a nonnegligible effect

Yan Li

1992-01-01

342

Human Resources Security Access Matrix Function Training  

E-print Network

June 2013 Human Resources Security Access Matrix Function Training Course Required Class Mode Training Course Prerequisite Security Access Form Required Contact for Additional Information Complete Electronic I-9 Forms REC001: I-9 /E-Verify Web Training OR Online OR None Electronic I-9 Security Access Form

Wu, Shin-Tson

343

Matrix of Hard and Soft Skills  

NSDL National Science Digital Library

This document was developed by Access Tech Careers to support successful course completion for students with learning disabilities. This matrix displays intersections between hard skills, including reading, writing, oral communication, and math, with soft skills, including critical thinking, teamwork, professionalism, and adaptability. It can help instructors integrate hard and soft skills in course planning.

2012-07-24

344

5D black holes and matrix strings  

Microsoft Academic Search

We derive the world-volume theory, the (non)-extremal entropy and background geometry of black holes and black strings constructed out of the NS IIA 5-brane within the framework of matrix theory. The CFT description of strings propagating in the black hole geometry arises as an effective field theory.

Robbert Dijkgraaf; Erik Verlinde; Herman L Verlinde

1997-01-01

345

Polymer matrix electroluminescent materials and devices  

DOEpatents

Photoluminescent and electroluminescent compositions are provided which comprise a matrix comprising aromatic repeat units covalently coordinated to a phosphorescent or luminescent metal ion or metal ion complexes. Methods for producing such compositions, and the electroluminescent devices formed therefrom, are also disclosed.

Marrocco, III, Matthew L. (Fontana, CA); Motamedi, Farshad J. (Claremont, CA); Abdelrazzaq, Feras Bashir (Covina, CA); Abdelrazzaq, legal representative, Bashir Twfiq (Aman, JO)

2012-06-26

346

Generalized Sylvester theorems for periodic applications in matrix optics  

NASA Astrophysics Data System (ADS)

Sylvester's theorem is often applied to problems involving light propagation through periodic optical systems represented by unimodular 2 X 2 transfer matrices. We extend this theorem to apply to broader classes of optics-related matrices. These matrices may be 2 X 2 or take on an important augmented 3 X 3 form. The results, which are summarized in tabular form, are useful for the analysis and the synthesis of a variety of optical systems, such as those that contain periodic distributed-feedback lasers, lossy birefringent filters, periodic pulse compressors, and misaligned lenses and mirrors. The results are also applicable to other types of system such as periodic electric circuits with intracavity independent sources, high-energy particle accelerators, and periodic computer graphics manipulations that may include object translation. As an example, we use the 3 X 3 form of Sylvester's theorem to examine Gaussian beam propagation in a misaligned resonator.

Tovar, Anthony A.; Casperson, Lee W.

1995-03-01

347

Matrix Manipulations by Computer: Direct Numerical Procedures for Basic Matrix Operations.  

National Technical Information Service (NTIS)

This paper describes a set of computer programs that develop a number of reasonably complex routines for determinant evaluation, solution of simultaneous equations, and matrix inversion; the programs are derived from a simple Gauss elimination technique f...

J. Staudhammer

1966-01-01

348

Universality in SRG-Evolved Potential Matrix Elements and T-Matrix Equivalence  

E-print Network

We examine how the universality of two-nucleon interactions evolved using similarity renormalization group (SRG) transformations correlates with T-matrix equivalence, with the ultimate goal of gaining insight into universality for three-nucleon forces. With sufficient running of the SRG flow equations, the low-energy matrix elements of different realistic potentials evolve to a universal form. Because these potentials are fit to low-energy data, they are (approximately) phase equivalent only up to a certain energy, and we find universality in evolved potentials up to the corresponding momentum. More generally we find universality in local energy regions, reflecting a local decoupling by the SRG. The further requirements for universality in evolved potential matrix elements are explored using two simple alternative potentials. We see evidence that in addition to predicting the same observables, common long-range potentials (i.e., explicit pion physics) is required for universality in the potential matrix eleme...

Dainton, B; Perry, R J

2014-01-01

349

Optimizing Tpetra%3CU%2B2019%3Es sparse matrix-matrix multiplication routine.  

SciTech Connect

Over the course of the last year, a sparse matrix-matrix multiplication routine has been developed for the Tpetra package. This routine is based on the same algorithm that is used in EpetraExt with heavy modifications. Since it achieved a working state, several major optimizations have been made in an effort to speed up the routine. This report will discuss the optimizations made to the routine, its current state, and where future work needs to be done.

Nusbaum, Kurtis Lee

2011-08-01

350

Fraction-Free Computation of Matrix Rational Interpolants and Matrix GCDs  

Microsoft Academic Search

We present a new set of algorithms for computation of matrix rational interpolantsand one-sided matrix greatest common divisors. Examples of these interpolantsinclude Pad'e approximants, Newton-Pad'e, Pad'e-Hermite, simultaneousPad'e approximants and more generally M-Pad'e approximants along with their matrixgeneralizations. The algorithms are fast and compute all solutions to a givenproblem. Solutions for all (possibly singular) subproblems along offdiagonal pathsin a solution table

Bernhard Beckermann; George Labahn

2000-01-01

351

Endothelial Matrix Assembly during Capillary Morphogenesis: Insights from Chimeric TagRFP-Fibronectin Matrix.  

PubMed

Biologically relevant, three-dimensional extracellular matrix is an essential component of in vitro vasculogenesis models. WI-38 fibroblasts assemble a 3D matrix that induces endothelial tubulogenesis, but this model is challenged by fibroblast senescence and the inability to distinguish endothelial cell-derived matrix from matrix made by WI-38 fibroblasts. Matrices produced by hTERT-immortalized WI-38 recapitulated those produced by wild type fibroblasts. ECM fibrils were heavily populated by tenascin-C, fibronectin, and type VI collagen. Nearly half of the total type I collagen, but only a small fraction of the type IV collagen, were incorporated into ECM. Stable hTERT-WI-38 transfectants expressing TagRFP-fibronectin incorporated TagRFP into ~90% of the fibronectin in 3D matrices. TagRFP-fibronectin colocalized with tenascin-C and with type I collagen in a pattern that was similar to that seen in matrices from wild type WI-38. Human Umbilical Vein Endothelial Cells (HUVEC) formed 3D adhesions and tubes on WI38-hTERT-TagRFP-FN-derived matrices, and the TagRFP-fibronectin component of this new 3D human fibroblast matrix model facilitated the demonstration of concentrated membrane type 1 metalloprotease and new HUVEC FN and collagen type IV fibrils during EC tubulogenesis. These findings indicate that WI-38-hTERT- and WI-38-hTERT-TagRFP-FN-derived matrices provide platforms for the definition of new matrix assembly and remodeling events during vasculogenesis. PMID:25063001

Chang, Fumin; Lemmon, Christopher A; Nilaratanakul, Voraphoj; Rotter, Varda; Romer, Lewis

2014-11-01

352

Universality in Similarity Renormalization Group Evolved Potential Matrix Elements and T-Matrix Equivalence  

E-print Network

We examine how the universality of two-nucleon interactions evolved using similarity renormalization group (SRG) transformations correlates with T-matrix equivalence, with the ultimate goal of gaining insight into universality for three-nucleon forces. With sufficient running of the SRG flow equations, the low-energy matrix elements of different realistic potentials evolve to a universal form. Because these potentials are fit to low-energy data, they are (approximately) phase equivalent only up to a certain energy, and we find universality in evolved potentials up to the corresponding momentum. More generally we find universality in local energy regions, reflecting a local decoupling by the SRG. The further requirements for universality in evolved potential matrix elements are explored using two simple alternative potentials. We see evidence that in addition to predicting the same observables, common long-range potentials (i.e., explicit pion physics) is required for universality in the potential matrix elements after SRG flow. In agreement with observations made previously for Vlowk evolution, regions of universal potential matrix elements are restricted to where half-on-shell T-matrix equivalence holds.

B. Dainton; R. J. Furnstahl; R. J. Perry

2013-10-24

353

The minimum amount of "matrix" needed for matrix-assisted pulsed laser deposition of biomolecules.  

PubMed

The ability of matrix-assisted pulsed laser evaporation (MAPLE) technique to transfer and deposit high-quality thin organic, bioorganic, and composite films with minimum chemical modification of the target material has been utilized in numerous applications. One of the outstanding problems in MAPLE film deposition, however, is the presence of residual solvent (matrix) codeposited with the polymer material and adversely affecting the quality of the deposited films. In this work, we investigate the possibility of alleviating this problem by reducing the amount of matrix in the target. A series of coarse-grained molecular dynamics simulations are performed for a model lysozyme-water system, where the water serves the role of volatile "matrix" that drives the ejection of the biomolecules. The simulations reveal a remarkable ability of a small (5-10 wt %) amount of matrix to cause the ejection of intact bioorganic molecules. The results obtained for different laser fluences and water concentrations are used to establish a "processing map" of the regimes of molecular ejection in matrix-assisted pulsed laser deposition. The computational predictions are supported by the experimental observation of the ejection of intact lysozyme molecules from pressed lysozyme targets containing small amounts of residual water. The results of this study suggest a new approach for deposition of thin films of bioorganic molecules with minimum chemical modification of the molecular structure and minimum involvement of solvent into the deposition process. PMID:25346998

Tabetah, Marshall; Matei, Andreea; Constantinescu, Catalin; Mortensen, Ninell P; Dinescu, Maria; Schou, Jørgen; Zhigilei, Leonid V

2014-11-20

354

Mid-infrared matrix assisted laser desorption ionization with a water/glycerol matrix  

NASA Astrophysics Data System (ADS)

Matrix-assisted laser desorption ionization (MALDI) mass spectra were obtained using a water and glycerol matrix with a tunable mid-infrared optical parametric oscillator. The matrix consists of a 1:1 mixture of water and glycerol deposited on a thin layer of nitrocellulose and cooled to -30°C. When exposed to vacuum, most of the water evaporates, leaving a matrix of glycerol with residual water. The peptide bradykinin and the protein bovine insulin were used to test this new matrix. Mass spectra were obtained for bradykinin between 2.76 and 3.1 ?m with the maximum analyte signal at 2.8 ?m. Mass resolution in excess of 2000 for bradykinin and 500 for insulin was obtained with delayed ion extraction and a linear time of flight mass spectrometer. The addition of nitrocellulose to the matrix resulted in exceptionally durable samples: more than 10,000 laser shots which produced analyte signal could be obtained from a single sample spot.

Caldwell, Kathleen L.; Murray, Kermit K.

1998-05-01

355

Luneburg lens and optical matrix algebra research  

NASA Technical Reports Server (NTRS)

Planar, as opposed to channelized, integrated optical circuits (IOCs) were stressed as the basis for computational devices. Both fully-parallel and systolic architectures are considered and the tradeoffs between the two device types are discussed. The Kalman filter approach is a most important computational method for many NASA problems. This approach to deriving a best-fit estimate for the state vector describing a large system leads to matrix sizes which are beyond the predicted capacities of planar IOCs. This problem is overcome by matrix partitioning, and several architectures for accomplishing this are described. The Luneburg lens work has involved development of lens design techniques, design of mask arrangements for producing lenses of desired shape, investigation of optical and chemical properties of arsenic trisulfide films, deposition of lenses both by thermal evaporation and by RF sputtering, optical testing of these lenses, modification of lens properties through ultraviolet irradiation, and comparison of measured lens properties with those expected from ray trace analyses.

Wood, V. E.; Busch, J. R.; Verber, C. M.; Caulfield, H. J.

1984-01-01

356

Mueller matrix imaging polarimetry in dermatology  

NASA Astrophysics Data System (ADS)

Recent studies have indicated that polarized light may be useful in the discrimination between benign and malignant moles. In fact, imaging polarimetry could provide noninvasive diagnosis of a range of dermatological disease states. However, in order to design an efficacious sensor for clinical use, the complete polarization-altering properties of a particular disease must be well understood. We present Mueller matrix imaging polarimetry as a technique for characterizing various dermatological diseases. Preliminary Mueller matrix imagery at 633 nm suggests that both malignant moles and lupus lesions may be identified through polarimetric measurements. Malignant moles are found to be less depolarizing than the surrounding tissue, and lupus lesions are found to have rapidly varying retardance orientation.

Smith, Matthew H.; Burke, Paul D.; Lompado, Arthur; Tanner, Elizabeth A.; Hillman, Lloyd W.

2000-05-01

357

A Multilevel Approach For Nonnegative Matrix Factorization  

E-print Network

Nonnegative Matrix Factorization (NMF) is the problem of approximating a nonnegative matrix with the product of two low-rank nonnegative matrices and has been shown to be particularly useful in many applications, e.g., in text mining, image processing, computational biology, etc. In this paper, we explain how algorithms for NMF can be embedded into the framework of multilevel methods in order to accelerate their convergence. This technique can be applied in situations where data admit a good approximate representation in a lower dimensional space through linear transformations preserving nonnegativity. A simple multilevel strategy is described and is experimentally shown to speed up significantly three popular NMF algorithms (alternating nonnegative least squares, multiplicative updates and hierarchical alternating least squares) on several standard image datasets.

Gillis, Nicolas

2010-01-01

358

Analysis of matrix metalloproteinase secretion by macrophages.  

PubMed

Matrix metalloproteinases (MMPs) are zinc-dependent proteases whose physiological roles include control of leukocyte migration. They are implicated in tissue destruction in inflammatory and infectious diseases. MMPs are not only capable of degrading all components of the extracellular matrix, but they also can modulate the immune response by cleaving cytokines and chemokines to alter their activity. Macrophages secrete a broad range of MMPs and represent a key source of MMPs in inflammatory lesions such as granulomas. Zymography is substrate-based gel electrophoresis that allows direct visualization of MMP activity. Here we describe measurement of MMP secretion from macrophages focusing on quantitative zymography. We also discuss complementary methods that should be used in parallel with zymography. The ability to analyze and quantify MMP secretion by macrophages offers an additional window through which to understand the contributions of macrophages to a wide variety of infectious, inflammatory, and immunologic disorders. PMID:19347322

Elkington, Paul T; Green, Justin A; Friedland, Jon S

2009-01-01

359

Matrix Factorizations, Minimal Models and Massey Products  

E-print Network

We present a method to compute the full non-linear deformations of matrix factorizations for ADE minimal models. This method is based on the calculation of higher products in the cohomology, called Massey products. The algorithm yields a polynomial ring whose vanishing relations encode the obstructions of the deformations of the D-branes characterized by these matrix factorizations. This coincides with the critical locus of the effective superpotential which can be computed by integrating these relations. Our results for the effective superpotential are in agreement with those obtained from solving the A-infinity relations. We point out a relation to the superpotentials of Kazama-Suzuki models. We will illustrate our findings by various examples, putting emphasis on the E_6 minimal model.

Johanna Knapp; Harun Omer

2006-04-25

360

Visualization of a stock market correlation matrix  

NASA Astrophysics Data System (ADS)

This paper presents a novel application of Neighbor-Net, a clustering algorithm developed for constructing a phylogenetic network in the field of evolutionary biology, to visualizing a correlation matrix. We apply Neighbor-Net as implemented in the SplitsTree software package to 48 stocks listed on the New Zealand Stock Exchange. We show that by visualizing the correlation matrix using a Neighbor-Net splits graph and its associated circular ordering of the stocks that some of the problems associated with understanding the large number of correlations between the individual stocks can be overcome. We compare the visualization of Neighbor-Net with that provided by hierarchical clustering trees and minimum spanning trees. The use of Neighbor-Net networks, or splits graphs, yields greater insight into how closely individual stocks are related to each other in terms of their correlations and suggests new avenues of research into how to construct small diversified stock portfolios.

Rea, Alethea; Rea, William

2014-04-01

361

Google matrix analysis of directed networks  

E-print Network

In past ten years, modern societies developed enormous communication and social networks. Their classification and information retrieval processing become a formidable task for the society. Due to the rapid growth of World Wide Web, social and communication networks, new mathematical methods have been invented to characterize the properties of these networks on a more detailed and precise level. Various search engines are essentially using such methods. It is highly important to develop new tools to classify and rank enormous amount of network information in a way adapted to internal network structures and characteristics. This review describes the Google matrix analysis of directed complex networks demonstrating its efficiency on various examples including World Wide Web, Wikipedia, software architecture, world trade, social and citation networks, brain neural networks, DNA sequences and Ulam networks. The analytical and numerical matrix methods used in this analysis originate from the fields of Markov chain...

Ermann, Leonardo; Shepelyansky, Dima L

2014-01-01

362

Primitive material surviving in chondrites - Matrix  

NASA Technical Reports Server (NTRS)

A logical place to search for surviving pristine nebular material is in the fine-grained matrices of ordinary and carbonaceous chondrites of petrographic type 3. Unfortunately, many of these chondrites have experienced brecciation, thermal metamorphism, and aqueous alteration, so that interpreting individual features in terms of specific nebular conditions and/or processes is difficult. It follows that the origin and evolutionary history of such matrix phases are controversial, and a consensus is difficult to define. In this chapter, therefore, after summarizing the salient mineralogical, petrographic, chemical, and isotopic features of matrix in apparently primitive chondrites, an attempt is made to provide an overview both of areas of agreement and of topics that are currently in dispute.

Scott, E. R. D.; Barber, D. J.; Alexander, C. M.; Hutchinson, R.; Peck, J. A.

1988-01-01

363

Quantitative matrix assisted plasma desorption mass spectrometry  

NASA Astrophysics Data System (ADS)

The development of optimized sample preparation methods accompanied the history of successful applications of 252Cf-PDMS. Studying the pharmacokinetics of the antineoplastic agent etoposide serum samples from cancer patients were labelled with the homologeous compounds teniposide as internal standard for the quantitative PDMS analysis. Sample purification by chloroform extraction and by thin layer chromatography turned out to be insufficient to guarantee a satisfying final PDMS result. Embedding the purified sample into a matrix of suitable substances on the target reduced the negative influence of impurities, raised the signal-to-noise ratio of molecular ions and improved the reproducibility of calibration. This preparation method was again successfully employed for the quantitative analysis of the cytostatic drug doxorubicin. The application of a different matrix optimized for the preparation of this anthracycline and its homologeous compound daunorubicin, improved the sensitivity, linearity and detection limit.

Jungclas, Hartmut; Schmidt, Lothar; Köhl, Peter; Fritsch, Hans-Walter

1993-07-01

364

Primitive ultrafine matrix in ordinary chondrites  

NASA Astrophysics Data System (ADS)

Ultrafine matrix material has been concentrated by sieving and filtering disaggregated samples of six ordinary chondrites of different classes. This component(s), 'Holy Smoke' (HS), is enriched in both volatile, e.g. Na, K, Zn, Sb, and Pb, as well as refractory elements, e.g. W and REE; however, the element ratios vary greatly among the different chondrites. SEM studies show that HS contains fragile crystals, differing in composition, and apparently in gross disequilibrium not only among themselves but also with the major mineral phases and consequently thermodynamic equilibration did not occur. Thus HS must have originated from impacting bodies and/or was inherent in the 'primitive' regolith. Subsequent impact brecciation and reheating appears to have altered, to varying degrees, the original composition of this ultrafine matrix material. Recent 'cosmic dust' studies may indicate that HS still exists in the solar system. Survival of such delicate material must be considered in all theories for the origin of chondrites.

Rambaldi, E. R.; Fredriksson, B. J.; Fredriksson, K.

1981-12-01

365

Primitive ultrafine matrix in ordinary chondrites  

NASA Technical Reports Server (NTRS)

Ultrafine matrix material has been concentrated by sieving and filtering disaggregated samples of six ordinary chondrites of different classes. This component(s), 'Holy Smoke' (HS), is enriched in both volatile, e.g. Na, K, Zn, Sb, and Pb, as well as refractory elements, e.g. W and REE; however, the element ratios vary greatly among the different chondrites. SEM studies show that HS contains fragile crystals, differing in composition, and apparently in gross disequilibrium not only among themselves but also with the major mineral phases and consequently thermodynamic equilibration did not occur. Thus HS must have originated from impacting bodies and/or was inherent in the 'primitive' regolith. Subsequent impact brecciation and reheating appears to have altered, to varying degrees, the original composition of this ultrafine matrix material. Recent 'cosmic dust' studies may indicate that HS still exists in the solar system. Survival of such delicate material must be considered in all theories for the origin of chondrites.

Rambaldi, E. R.; Fredriksson, B. J.; Fredriksson, K.

1981-01-01

366

Retroviral matrix and lipids, the intimate interaction  

PubMed Central

Retroviruses are enveloped viruses that assemble on the inner leaflet of cellular membranes. Improving biophysical techniques has recently unveiled many molecular aspects of the interaction between the retroviral structural protein Gag and the cellular membrane lipids. This interaction is driven by the N-terminal matrix domain of the protein, which probably undergoes important structural modifications during this process, and could induce membrane lipid distribution changes as well. This review aims at describing the molecular events occurring during MA-membrane interaction, and pointing out their consequences in terms of viral assembly. The striking conservation of the matrix membrane binding mode among retroviruses indicates that this particular step is most probably a relevant target for antiviral research. PMID:21385335

2011-01-01

367

Pfaffian Expressions for Random Matrix Correlation Functions  

E-print Network

It is well known that Pfaffian formulas for eigenvalue correlations are useful in the analysis of real and quaternion random matrices. Moreover the parametric correlations in the crossover to complex random matrices are evaluated in the forms of Pfaffians. In this article, we review the formulations and applications of Pfaffian formulas. For that purpose, we first present the general Pfaffian expressions in terms of the corresponding skew orthogonal polynomials. Then we clarify the relation to Eynard and Mehta's determinant formula for hermitian matrix models and explain how the evaluation is simplified in the cases related to the classical orthogonal polynomials. Applications of Pfaffian formulas to random matrix theory and other fields are also mentioned.

Taro Nagao

2007-08-15

368

Fetal hypoxia and programming of matrix metalloproteinases  

PubMed Central

Fetal hypoxia adversely affects the brain and heart development, yet the mechanisms responsible remain elusive. Recent studies indicate an important role of the extracellular matrix in fetal development and tissue remodeling. The matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs) have been implicated in a variety of physiological and pathological processes in the cardiovascular and central nervous systems. This review summarizes current knowledge of the mechanisms by which fetal hypoxia induces the imbalance of MMPs, TIMPs and collagen expression patterns, resulting in growth restriction and aberrant tissue remodeling in the developing heart and brain. Collectively, this information could lead to the development of preventive diagnoses and therapeutic strategies in the fetal programming of cardiovascular and neurological disorders. PMID:21946060

Tong, Wenni; Zhang, Lubo

2011-01-01

369

Solidification processing of monotectic alloy matrix composites  

NASA Technical Reports Server (NTRS)

Directionally solidified aluminum-indium alloys of the monotectic composition were found to form an in situ rod composite which obeys a lambda exp 2 R = constant relation. The experimental data shows good agreement with previously reported results. A theoretical boundary between cellular and dendritic growth conditions was derived and compared with experiments. The unique wetting characteristics of the monotectic alloys can be utilized to tailor the interface structure in metal matrix composites. Metal matrix composites with monotectic and hypermonotectic Al-In matrices were made by pressure infiltration, remelted and directionally solidified to observe the wetting characteristics of the alloys as well as the effect on structure of solidification in the constrained field of the fiber interstices. Models for monotectic growth are modified to take into account solidification in these constrained fields.

Frier, Nancy L.; Shiohara, Yuh; Russell, Kenneth C.

1989-01-01

370

Matrix control of transforming growth factor-? function  

PubMed Central

The cytokine transforming growth factor-beta (TGF-?) has multiple effects in both physiological and pathological conditions. TGF-? is secreted as part of a tripartite complex from which it must be released in order to bind to its receptor. Sequestration of latent TGF-? in the extracellular matrix (ECM) is crucial for proper mobilization of the latent cytokine and its activation. However, contrary to expectation, loss-of-function mutations in genes encoding certain matrix proteins that bind TGF-? yield elevated, rather than decreased, TGF-? levels, posing a ‘TGF-? paradox.’ In this review, we discuss recent findings concerning the relationship of TGF-?, ECM molecules, and latent TGF-? activation and propose a model to resolve the ‘TGF-? paradox.’ PMID:22923731

Horiguchi, Masahito; Ota, Mitsuhiko; Rifkin, Daniel B.

2012-01-01

371

Extracellular matrix and developing growth plate.  

PubMed

Growth plate is a specialized cartilaginous structure that mediates the longitudinal growth of skeletal bones. It consists of ordered zones of chondrocytes that secrete an extracellular matrix (ECM) composed of specific types of collagens and proteoglycans. Several heritable human skeletal dysplasias are caused by mutations in these ECM components and this review focuses on the roles of type II, IX, X, and XI collagens, aggrecan, matrilins, perlecan, and cartilage oligomeric matrix protein in the growth plate as deduced from human disease phenotypes and mouse models. Substantial advances have been achieved in deciphering the interaction networks and individual roles of these components in the construction of the growth plate ECM. Furthermore, ER stress and other cellular responses have been identified as key downstream effects of the ECM mutations contributing to abnormal growth plate development. The next challenge is to utilize the molecular level knowledge for the development of potential therapeutics. PMID:25212565

Myllyharju, Johanna

2014-12-01

372

Advanced ceramic matrix composites for TPS  

NASA Technical Reports Server (NTRS)

Recent advances in ceramic matrix composite (CMC) technology provide considerable opportunity for application to future aircraft thermal protection system (TPS), providing materials with higher temperature capability, lower weight, and higher strength and stiffness than traditional materials. The Thermal Protection Material Branch at NASA Ames Research Center has been making significant progress in the development, characterization, and entry simulation (arc-jet) testing of new CMC's. This protection gives a general overview of the Ames Thermal Protection Materials Branch research activities, followed by more detailed descriptions of recent advances in very-high temperature Zr and Hf based ceramics, high temperature, high strength SiC matrix composites, and some activities in polymer precursors and ceramic coating processing. The presentation closes with a brief comparison of maximum heat flux capabilities of advanced TPS materials.

Rasky, Daniel J.

1992-01-01

373

Electrophilic properties of common MALDI matrix molecules  

NASA Astrophysics Data System (ADS)

The negative ion photoelectron spectra of the following MALDI matrix molecules have been measured: 3-carboxypyridine (nicotinic acid), 2,5-dihydroxybenzoic acid (DHB), 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid), 2,6-dihydroxyacetophenone (DHAP), 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid (ferulic acid), 3-hydroxy-2-pyridinecarboxylic acid (3HPA), and 2,6-pyridinedicarboxylic acid (dipicolinic acid). Adiabatic electron affinities and vertical detachment energies were extracted from these spectra and reported. In addition, electron affinities were calculated for DHAP, ferulic acid, dipicolinic acid and sinapinic acid. Photoelectron spectra were also measured for the dimer anions of DHB and nicotinic acid and for the fragment anion in which alpha-cyano-cinnamic acid had lost a CO2 unit. Together, these results augment the database of presently available electrophilic data on common matrix molecules along with some of their dimers and fragments.

Lippa, T. P.; Eustis, S. N.; Wang, D.; Bowen, K. H.

2007-11-01

374

Automation of the matrix element reweighting method  

E-print Network

Matrix element reweighting is a powerful experimental technique widely employed to maximize the amount of information that can be extracted from a collider data set. We present a procedure that allows to automatically evaluate the weights for any process of interest in the standard model and beyond. Given the initial, intermediate and final state particles, and the transfer functions for the final physics objects, such as leptons, jets, missing transverse energy, our algorithm creates a phase-space mapping designed to efficiently perform the integration of the squared matrix element and the transfer functions. The implementation builds up on MadGraph, it is completely automatized and publicly available. A few sample applications are presented that show the capabilities of the code and illustrate the possibilities for new studies that such an approach opens up.

P. Artoisenet; V. Lemaître; F. Maltoni; O. Mattelaer

2010-07-19

375

Efficient Computation Of Manipulator Inertia Matrix  

NASA Technical Reports Server (NTRS)

Improved method for computation of manipulator inertia matrix developed, based on concept of spatial inertia of composite rigid body. Required for implementation of advanced dynamic-control schemes as well as dynamic simulation of manipulator motion. Motivated by increasing demand for fast algorithms to provide real-time control and simulation capability and, particularly, need for faster-than-real-time simulation capability, required in many anticipated space teleoperation applications.

Fijany, Amir; Bejczy, Antal K.

1991-01-01

376

Nanophosphor composite scintillators comprising a polymer matrix  

DOEpatents

An improved nanophosphor composite comprises surface modified nanophosphor particles in a solid matrix. The nanophosphor particle surface is modified with an organic ligand, or by covalently bonding a polymeric or polymeric precursor material. The surface modified nanophosphor particle is essentially charge neutral, thereby preventing agglomeration of the nanophosphor particles during formation of the composite material. The improved nanophosphor composite may be used in any conventional scintillator application, including in a radiation detector.

Muenchausen, Ross Edward (Los Alamos, NM); Mckigney, Edward Allen (Los Alamos, NM); Gilbertson, Robert David (Los Alamos, NM)

2010-11-16

377

Metal matrix composite structural panel construction  

NASA Technical Reports Server (NTRS)

Lightweight capped honeycomb stiffeners for use in fabricating metal or metal/matrix exterior structural panels on aerospace type vehicles and the process for fabricating same are disclosed. The stiffener stringers are formed in sheets, cut to the desired width and length and brazed in spaced relationship to a skin with the honeycomb material serving directly as the required lightweight stiffeners and not requiring separate metal encasement for the exposed honeycomb cells.

Mcwithey, R. R.; Royster, D. M. (inventors); Bales, T. T.

1983-01-01

378

Ceramic Matrix Composites for Rotorcraft Engines  

NASA Technical Reports Server (NTRS)

Ceramic matrix composite (CMC) components are being developed for turbine engine applications. Compared to metallic components, the CMC components offer benefits of higher temperature capability and less cooling requirements which correlates to improved efficiency and reduced emissions. This presentation discusses a technology develop effort for overcoming challenges in fabricating a CMC vane for the high pressure turbine. The areas of technology development include small component fabrication, ceramic joining and integration, material and component testing and characterization, and design and analysis of concept components.

Halbig, Michael C.

2011-01-01

379

Effective dynamics of the matrix big bang  

Microsoft Academic Search

We study the leading quantum effects in the recently introduced matrix big bang model. This amounts to a study of supersymmetric Yang-Mills theory compactified on the Milne orbifold. We find a one-loop potential that is attractive near the big bang. Surprisingly, the potential decays very rapidly at late times where it appears to be generated by D-brane effects. Usually, general

B. E. L. Craps; Arvind Rajaraman; Savdeep Sethi

2006-01-01

380

Thermal expansion measurements of metal matrix composites  

NASA Technical Reports Server (NTRS)

The laser-interferometric-dilatometer system currently operational at NASA-Langley is described. The system, designed to characterize metal matrix composites, features high precision, automated data acquisition, and the ability to test a wide variety of specimen geometries over temperature ranges within 80-422 K. The paper presents typical thermal-expansion measurement data for a Gr/Al rod; Gr/Al and Gr/Mg unidirectional laminates; and a Gr/Mg (+ or -8)s laminate.

Tompkins, Stephen S.; Dries, Gregory A.

1988-01-01

381

Twisted mass QCD for weak matrix elements  

E-print Network

I report on the application of tmQCD techniques to the computation of hadronic matrix elements of four-fermion operators. Emphasis is put on the computation of $B_K$ in quenched QCD performed by the ALPHA Collaboration. The extension of tmQCD strategies to the study of neutral $B$-meson mixing is briefly discussed. Finally, some remarks are made concerning proposals to apply tmQCD to the computation of $K\\to\\pi\\pi$ amplitudes.

Carlos Pena

2006-10-19

382

Abrasive wear of metallic matrix reinforced materials  

Microsoft Academic Search

It is presented an investigation of the abrasive wear behaviour of metallic matrix reinforced materials (MMRMs). Micro-scale wear tests were performed on Fe–Cr–C\\/NbC composite materials with different volume fractions of reinforcement particles, produced by variable powder feed rate laser cladding. The obtained results show that, depending on the conditions on which the wear tests were made, the wear resistance of

R Colaço; R Vilar

2003-01-01

383

Matrix geometries emergent from a point  

NASA Astrophysics Data System (ADS)

We describe a categorical approach to finite noncommutative geometries. Objects in the category are spectral triples, rather than unitary equivalence classes as in other approaches. This enables us to treat fluctuations of the metric and unitary equivalences on the same footing, as representatives of particular morphisms in this category. We then show how a matrix geometry (Moyal plane) emerges as a fluctuation from one point, and discuss some geometric aspects of this space.

D'Andrea, Francesco; Lizzi, Fedele; Martinetti, Pierre

2014-10-01

384

On recrystallization in metal matrix composites  

SciTech Connect

The plane strain deformation of model continuous fibre composites such as Cu-W provides a vehicle for the study of the macroscopic effects of second phase particles on the strain distribution in the matrix and its possible effects on subsequent recrystallization behaviour. By using metallographic studies based both on optical gridding methods and low temperature recrystallization, the pattern of flow enforced by the fibres can be quantified and related to the spatial distribution of recrystallization events.

Poole, W.J.; Embury, J.D. [McMaster Univ., Hamilton, ON (Canada); Silvetti, S.P. [Cordoba Univ. Nacional (Argentina); Kocks, U.F. [Los Alamos National Lab., NM (United States)

1992-05-01

385

On recrystallization in metal matrix composites  

SciTech Connect

The plane strain deformation of model continuous fibre composites such as Cu-W provides a vehicle for the study of the macroscopic effects of second phase particles on the strain distribution in the matrix and its possible effects on subsequent recrystallization behaviour. By using metallographic studies based both on optical gridding methods and low temperature recrystallization, the pattern of flow enforced by the fibres can be quantified and related to the spatial distribution of recrystallization events.

Poole, W.J.; Embury, J.D. (McMaster Univ., Hamilton, ON (Canada)); Silvetti, S.P. (Cordoba Univ. Nacional (Argentina)); Kocks, U.F. (Los Alamos National Lab., NM (United States))

1992-01-01

386

Ceramic Matrix Composite Vane Subelement Burst Testing  

NASA Technical Reports Server (NTRS)

Burst tests were performed on Ceramic Matrix Composite (CMC) vane specimens, manufactured by two vendors, under the Ultra Efficient Engine Technology (UEET) project. Burst specimens were machined from the ends of 76mm long vane sub-elements blanks and from High Pressure Burner Rig (HPBR) tested specimens. The results of burst tests will be used to compare virgin specimens with specimens that have had an Environmental Barrier Coating (EBC) applied, both HPBR tested and untested, as well as a comparison between vendors.

Brewer, David N.; Verrilli, Michael; Calomino, Anthony

2006-01-01

387

Airspace Operations Demo Functional Requirements Matrix  

NASA Technical Reports Server (NTRS)

The Flight IPT assessed the reasonableness of demonstrating each of the Access 5 Step 1 functional requirements. The functional requirements listed in this matrix are from the September 2005 release of the Access 5 Functional Requirements Document. The demonstration mission considered was a notional Western US mission (WUS). The conclusion of the assessment is that 90% of the Access 5 Step 1 functional requirements can be demonstrated using the notional Western US mission.

2005-01-01

388

Transferring elements of a density matrix  

SciTech Connect

We study restrictions imposed by quantum mechanics on the process of matrix-element transfer. This problem is at the core of quantum measurements and state transfer. Given two systems A and B with initial density matrices lambda and r, respectively, we consider interactions that lead to transferring certain matrix elements of unknown lambda into those of the final state r-tilde of B. We find that this process eliminates the memory on the transferred (or certain other) matrix elements from the final state of A. If one diagonal matrix element is transferred, r(tilde sign){sub aa}=lambda{sub aa}, the memory on each nondiagonal element lambda{sub an}ot ={sub b} is completely eliminated from the final density operator of A. Consider the following three quantities, Relambda{sub an}ot ={sub b}, Imlambda{sub an}ot ={sub b}, and lambda{sub aa}-lambda{sub bb} (the real and imaginary part of a nondiagonal element and the corresponding difference between diagonal elements). Transferring one of them, e.g., Rer(tilde sign){sub an}ot ={sub b}=Relambda{sub an}ot ={sub b}, erases the memory on two others from the final state of A. Generalization of these setups to a finite-accuracy transfer brings in a trade-off between the accuracy and the amount of preserved memory. This trade-off is expressed via system-independent uncertainty relations that account for local aspects of the accuracy-disturbance trade-off in quantum measurements. Thus, the general aspect of state disturbance in quantum measurements is elimination of memory on non-diagonal elements, rather than diagonalization.

Allahverdyan, Armen E. [Yerevan Physics Institute, Alikhanian Brothers Street 2, Yerevan 375036 (Armenia); Hovhannisyan, Karen V. [Yerevan Physics Institute, Alikhanian Brothers Street 2, Yerevan 375036 (Armenia); Yerevan State University, A. Manoogian Street 1, Yerevan (Armenia)

2010-01-15

389

Boost matrix converters in clean energy systems  

NASA Astrophysics Data System (ADS)

This dissertation describes an investigation of novel power electronic converters, based on the ultra-sparse matrix topology and characterized by the minimum number of semiconductor switches. The Z-source, Quasi Z-source, Series Z-source and Switched-inductor Z-source networks were originally proposed for boosting the output voltage of power electronic inverters. These ideas were extended here on three-phase to three-phase and three-phase to single-phase indirect matrix converters. For the three-phase to three-phase matrix converters, the Z-source networks are placed between the three-switch input rectifier stage and the output six-switch inverter stage. A brief shoot-through state produces the voltage boost. An optimal pulse width modulation technique was developed to achieve high boosting capability and minimum switching losses in the converter. For the three-phase to single-phase matrix converters, those networks are placed similarly. For control purposes, a new modulation technique has been developed. As an example application, the proposed converters constitute a viable alternative to the existing solutions in residential wind-energy systems, where a low-voltage variable-speed generator feeds power to the higher-voltage fixed-frequency grid. Comprehensive analytical derivations and simulation results were carried out to investigate the operation of the proposed converters. Performance of the proposed converters was then compared between each other as well as with conventional converters. The operation of the converters was experimentally validated using a laboratory prototype.

Karaman, Ekrem

390

A tough high performance composite matrix  

NASA Technical Reports Server (NTRS)

This invention is a semi-interpenetrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide. An improved high temperature matrix resin is provided which is capable of performing in the 200 to 300 C range. This resin has significantly improved toughness and microcracking resistance, excellent processability, mechanical performance and moisture and solvent resistances.

Pater, Ruth H. (inventor); Johnston, Norman J. (inventor)

1992-01-01

391

The phase transition of matrix recovery from Gaussian measurements matches the minimax MSE of matrix denoising.  

PubMed

Let X(0) be an unknown M by N matrix. In matrix recovery, one takes n < MN linear measurements y(1),…,y(n) of X(0), where y(i) = Tr(A(T)iX(0)) and each A(i) is an M by N matrix. A popular approach for matrix recovery is nuclear norm minimization (NNM): solving the convex optimization problem min ||X||*subject to y(i) =Tr(A(T)(i)X) for all 1 ? i ? n, where || · ||* denotes the nuclear norm, namely, the sum of singular values. Empirical work reveals a phase transition curve, stated in terms of the undersampling fraction ?(n,M,N) = n/(MN), rank fraction ?=rank(X0)/min {M,N}, and aspect ratio ?=M/N. Specifically when the measurement matrices Ai have independent standard Gaussian random entries, a curve ?*(?) = ?*(?;?) exists such that, if ? > ?*(?), NNM typically succeeds for large M,N, whereas if ? < ?*(?), it typically fails. An apparently quite different problem is matrix denoising in Gaussian noise, in which an unknown M by N matrix X(0) is to be estimated based on direct noisy measurements Y =X(0) + Z, where the matrix Z has independent and identically distributed Gaussian entries. A popular matrix denoising scheme solves the unconstrained optimization problem min|| Y-X||(2)(F)/2+?||X||*. When optimally tuned, this scheme achieves the asymptotic minimax mean-squared error M(?;?) = lim(M,N ? ?)inf(?)sup(rank(X) ? ? · M)MSE(X,X(?)), where M/N ? . We report extensive experiments showing that the phase transition ?*(?) in the first problem, matrix recovery from Gaussian measurements, coincides with the minimax risk curve M(?)=M(?;?) in the second problem, matrix denoising in Gaussian noise: ?*(?)=M(?), for any rank fraction 0 < ? < 1 (at each common aspect ratio ?). Our experiments considered matrices belonging to two constraint classes: real M by N matrices, of various ranks and aspect ratios, and real symmetric positive-semidefinite N by N matrices, of various ranks. PMID:23650360

Donoho, David L; Gavish, Matan; Montanari, Andrea

2013-05-21

392

Full CKM matrix with lattice QCD  

SciTech Connect

The authors show that it is now possible to fully determine the CKM matrix, for the first time, using lattice QCD. |V{sub cd}|, |V{sub cs}|, |V{sub ub}|, |V{sub cb}| and |V{sub us}| are, respectively, directly determined with the lattice results for form factors of semileptonic D {yields} {pi}lv, D {yields} Klv, B {yields} {pi}lv, B {yields} Dlv and K {yields} {pi}lv decays. The error from the quenched approximation is removed by using the MILC unquenced lattice gauge configurations, where the effect of u, d and s quarks is included. The error from the ''chiral'' extrapolation (m{sub l} {yields} m{sub ud}) is greatly reduced by using improved staggered quarks. The accuracy is comparable to that of the Particle Data Group averages. In addition, |V{sub ud}|, |V{sub ts}|, |V{sub ts}| and |V{sub td}| are determined by using unitarity of the CKM matrix and the experimental result for sin (2{beta}). In this way, they obtain all 9 CKM matrix elements, where the only theoretical input is lattice QCD. They also obtain all the Wolfenstein parameters, for the first time, using lattice QCD.

Okamoto, Masataka; /Fermilab

2004-12-01

393

Matrix elasticity directs stem cell lineage specification  

NASA Astrophysics Data System (ADS)

Adhesion of stem cells - like most cells - is not just a membrane phenomenon. Most tissue cells need to adhere to a ``solid'' for viability, and over the last decade it has become increasingly clear that the physical ``elasticity'' of that solid is literally ``felt'' by cells. Here we show that Mesenchymal Stem Cells (MSCs) specify lineage and commit to phenotypes with extreme sensitivity to the elasticity typical of tissues [1]. In serum only media, soft matrices that mimic brain appear neurogenic, stiffer matrices that mimic muscle are myogenic, and comparatively rigid matrices that mimic collagenous bone prove osteogenic. Inhibition of nonmuscle myosin II activity blocks all elasticity directed lineage specification, which indicates that the cytoskeleton pulls on matrix through adhesive attachments. Results have significant implications for `therapeutic' stem cells and have motivated development of a proteomic-scale method to identify mechano-responsive protein structures [2] as well as deeper physical studies of matrix physics [3] and growth factor pathways [4]. [4pt] [1] A. Engler, et al. Matrix elasticity directs stem cell lineage specification. Cell (2006).[0pt] [2] C.P. Johnson, et al. Forced unfolding of proteins within cells. Science (2007).[0pt] [3] A.E.X. Brown, et al. Multiscale mechanics of fibrin polymer: Gel stretching with protein unfolding and loss of water. Science (2009).[0pt] [4] D.E. Discher, et al. Growth factors, matrices, and forces combine and control stem cells. Science (2009).

Discher, Dennis

2010-03-01

394

Multispectral palmprint recognition using a quaternion matrix.  

PubMed

Palmprints have been widely studied for biometric recognition for many years. Traditionally, a white light source is used for illumination. Recently, multispectral imaging has drawn attention because of its high recognition accuracy. Multispectral palmprint systems can provide more discriminant information under different illuminations in a short time, thus they can achieve better recognition accuracy. Previously, multispectral palmprint images were taken as a kind of multi-modal biometrics, and the fusion scheme on the image level or matching score level was used. However, some spectral information will be lost during image level or matching score level fusion. In this study, we propose a new method for multispectral images based on a quaternion model which could fully utilize the multispectral information. Firstly, multispectral palmprint images captured under red, green, blue and near-infrared (NIR) illuminations were represented by a quaternion matrix, then principal component analysis (PCA) and discrete wavelet transform (DWT) were applied respectively on the matrix to extract palmprint features. After that, Euclidean distance was used to measure the dissimilarity between different features. Finally, the sum of two distances and the nearest neighborhood classifier were employed for recognition decision. Experimental results showed that using the quaternion matrix can achieve a higher recognition rate. Given 3000 test samples from 500 palms, the recognition rate can be as high as 98.83%. PMID:22666049

Xu, Xingpeng; Guo, Zhenhua; Song, Changjiang; Li, Yafeng

2012-01-01

395

Demineralized bone matrix for alveolar cleft management.  

PubMed

The aim of this article is to describe the results of the use of demineralized bone matrix putty in alveolar cleft of patients with cleft lip and palate. We performed a prospective, descriptive case series study, in which we evaluated the results of the management of alveolar clefts with demineralized bone matrix. Surgery was performed in 10 patients aged between 7 and 26 years (mean 13 years), involving a total of 13 clefts in the 10 patients. A preoperative cone beam computed tomography (CBCT) was taken to the patients in whom the width of the cleft was measured from each edge of the cleft reporting values between 5.76 and 16.93?mm (average, 11.18 mm). The densities of the clefts were measured with a CBCT, 6 months postoperative to assess bone formation. The results showed a register of gray values of 1,148 to 1,396 (mean, 1,270). The follow-up was conducted for 15 to 33 months (mean, 28.2 months). The results did not show satisfactory bone formation in the cleft of patients with the use of demineralized bone matrix. PMID:25383144

Madrid, Jose Rolando Prada; Gomez, Viviana; Mendoza, Bibiana

2014-12-01

396

Tuberculosis, pulmonary cavitation, and matrix metalloproteinases.  

PubMed

Tuberculosis (TB), a chronic infectious disease of global importance, is facing the emergence of drug-resistant strains with few new drugs to treat the infection. Pulmonary cavitation, the hallmark of established disease, is associated with very high bacillary burden. Cavitation may lead to delayed sputum culture conversion, emergence of drug resistance, and transmission of the infection. The host immunological reaction to Mycobacterium tuberculosis is implicated in driving the development of TB cavities. TB is characterized by a matrix-degrading phenotype in which the activity of proteolytic matrix metalloproteinases (MMPs) is relatively unopposed by the specific tissue inhibitors of metalloproteinases. Proteases, in particular MMPs, secreted from monocyte-derived cells, neutrophils, and stromal cells, are involved in both cell recruitment and tissue damage and may cause cavitation. MMP activity is augmented by proinflammatory chemokines and cytokines, is tightly regulated by complex signaling paths, and causes matrix destruction. MMP concentrations are elevated in human TB and are closely associated with clinical and radiological markers of lung tissue destruction. Immunomodulatory therapies targeting MMPs in preclinical and clinical trials are potential adjuncts to TB treatment. Strategies targeting patients with cavitary TB have the potential to improve cure rates and reduce disease transmission. PMID:24713029

Ong, Catherine W M; Elkington, Paul T; Friedland, Jon S

2014-07-01

397

S-matrix renormalization in effective theories  

SciTech Connect

This is the fifth paper in the series devoted to explicit formulation of the rules needed to manage an effective field theory of strong interactions in S-matrix sector. We discuss the principles of constructing the meaningful perturbation series and formulate two basic ones: uniformity and summability. Relying on these principles, one obtains the bootstrap conditions which restrict the allowed values of the physical (observable) parameters appearing in the extended perturbation scheme built for a given localizable effective theory. The renormalization prescriptions needed to fix the finite parts of counterterms in such a scheme can be divided into two subsets: minimal, needed to fix the S-matrix, and nonminimal, for eventual calculation of Green functions; in this paper we consider only the minimal one. In particular, it is shown that, in theories with the asymptotic behavior governed by known Regge intercepts, the system of independent renormalization conditions only contains those fixing the counterterm vertices with n{<=}3 lines, while other prescriptions are determined by self-consistency requirements. Moreover, the prescriptions for n{<=}3 cannot be taken arbitrarily: an infinite number of bootstrap conditions should be respected. The concept of localizability, introduced and explained in this article, is closely connected with the notion of resonance in the framework of perturbative quantum field theory. We discuss this point and, finally, compare the cornerstones of our approach with the philosophy known as ''analytic S-matrix.''.

Semenov-Tian-Shansky, K. [Departement de Physique, Universite de Liege au Sart Tilman, B5a, B4000 Liege 1 (Belgium); Theoretical Physics Department, Institute of Physics, St. Petersburg State University, St. Petersburg, Petrodvoretz, 198504 (Russian Federation); Vereshagin, A. [Institute of Physics and Technology, Allegaten 55, N5007 Bergen (Norway); Theoretical Physics Department, Institute of Physics, St. Petersburg State University, St. Petersburg, Petrodvoretz, 198504 (Russian Federation); Vereshagin, V. [Theoretical Physics Department, Institute of Physics, St. Petersburg State University, St. Petersburg, Petrodvoretz, 198504 (Russian Federation)

2006-01-15

398

Comparison of interfinger connection matrix computation techniques.  

PubMed

A hypothesis was proposed that the central nervous system controls force production by the fingers through hypothetical neural commands. The neural commands are scaled between values of 0 to 1, indicating no intentional force production or maximal voluntary contraction (MVC) force production, respectively. A matrix of interfinger connections transforms neural commands into finger forces. Two methods have been proposed to compute the interfinger connection matrix. The first method uses only single finger MVC trials and multiplies the interfinger connection matrix by a gain factor. The second method uses a neural network model based on experimental data. The performance of the two methods was compared on the MVC data and on a data set of submaximal forces, collected over a range of total forces and moments of force. The methods were compared in terms of (1) ability to predict finger forces, (2) accuracy of neural command reconstruction, and (3) preserved planarity of force data for submaximal force production task. Both methods did a reasonable job of predicting the total force in multifinger MVC trials; however, the neural network model performed better in regards to all other criteria. Overall, the results indicate that for modeling multifinger interaction the neural network method is preferable. PMID:23183029

Martin, Joel R; Terekhov, Alexander V; Latash, Mark L; Zatsiorsky, Vladimir M

2013-10-01

399

Research on graphite reinforced glass matrix composites  

NASA Technical Reports Server (NTRS)

High levels of mechanical performance in tension, flexure, fatigue, and creep loading situations of graphite fiber reinforced glass matrix composites are discussed. At test temperatures of up to 813 K it was found that the major limiting factor was the oxidative instability of the reinforcing graphite fibers. Particular points to note include the following: (1) a wide variety of graphite fibers were found to be comparable with the glass matrix composite fabrication process; (2) choice of fiber, to a large extent, controlled resultant composite performance; (3) composite fatigue performance was found to be excellent at both 300 K and 703 K; (4) composite creep and stress rupture at temperatures of up to 813 K was limited by the oxidative stability of the fiber; (5) exceptionally low values of composite thermal expansion coefficient were attributable to the dimensional stability of both matrix and fiber; and (6) component fabricability was demonstrated through the hot pressing of hot sections and brazing using glass and metal joining phases.

Prewo, K. M.; Thompson, E. R.

1980-01-01

400

Constructing acoustic timefronts using random matrix theory.  

PubMed

In a recent letter [Hegewisch and Tomsovic, Europhys. Lett. 97, 34002 (2012)], random matrix theory is introduced for long-range acoustic propagation in the ocean. The theory is expressed in terms of unitary propagation matrices that represent the scattering between acoustic modes due to sound speed fluctuations induced by the ocean's internal waves. The scattering exhibits a power-law decay as a function of the differences in mode numbers thereby generating a power-law, banded, random unitary matrix ensemble. This work gives a more complete account of that approach and extends the methods to the construction of an ensemble of acoustic timefronts. The result is a very efficient method for studying the statistical properties of timefronts at various propagation ranges that agrees well with propagation based on the parabolic equation. It helps identify which information about the ocean environment can be deduced from the timefronts and how to connect features of the data to that environmental information. It also makes direct connections to methods used in other disordered waveguide contexts where the use of random matrix theory has a multi-decade history. PMID:24116514

Hegewisch, Katherine C; Tomsovic, Steven

2013-10-01

401

Local matrix generalizations of $W$-algebras  

E-print Network

In this paper, we propose local matrix generalizations of the classical $W$-algebras based on the second Hamiltonian structure of the $\\mathcal{Z}_m$-valued KP hierarchy, where $\\mathcal{Z}_m$ is a maximal commutative subalgebra of $gl(m,\\mathbb{C})$. More precisely, firstly we give a brief discussion about the Sato theory of the $\\mathcal{Z}_m$-KP hierarchy. Secondly we construct its bihamiltonian structure and propose two kinds of local matrix generalizations of the $\\mbox{W}_{\\mathbb{KP}}^{(n)}$-algebra and the $\\mbox{W}_\\infty^{(n)}$-algebra, namely the $\\mbox{W}_{\\mathbb{KP}}^{(m,n)}$-algebra and the $\\mbox{W}_\\infty^{(m,n)}$-algebra. Furthermore by constructing a Miura map we describe free-field realizations of the above W-type algebras. Afterwards, we study the dispersionless analogue of the $\\mathcal{Z}_m$-KP hierarchy including the bi-hamiltonian structure, the Miura map, local matrix $w$-type algebras and their free-field realizations. Finally we discuss the relation between Frobenius manifolds and the dispersionless $\\mathcal{Z}_m$-$\\mbox{GD}_n$ hierarchy. When $m>1$, the corresponding Frobenuis mainfolds are nonsemisimple.

Dafeng Zuo

2014-01-10

402

Extracellular matrix rigidity promotes invadopodia activity  

PubMed Central

Summary Invadopodia are actin-rich subcellular protrusions with associated proteases used by cancer cells to degrade extracellular matrix (ECM) [1]. Molecular components of invadopodia include branched actin assembly proteins, membrane trafficking proteins, signaling proteins and transmembrane proteinases[1]. Similar structures exist in nontransformed cells, such as osteoclasts and dendritic cells, but are generally called podosomes and are thought to be more involved in cell-matrix adhesion than invadopodia [2–4]. Despite intimate contact with their ECM substrates, it is unknown whether physical or chemical ECM signals regulate invadopodia function. Here, we report that ECM rigidity directly increases both the number and activity of invadopodia. Transduction of ECM rigidity signals depends on the cellular contractile apparatus [5–7], as inhibition of nonmuscle myosin II, myosin light chain kinase, and Rho kinase all abrogate invadopodia-associated ECM degradation. Whereas myosin IIA, IIB, and phosphorylated myosin light chain do not localize to invadopodia puncta, active phosphorylated forms of the mechanosensing proteins p130Cas (Cas) and focal adhesion kinase (FAK) are present in actively degrading invadopodia and the levels of phospho-Cas and phospho-FAK in invadopodia are sensitive to myosin inhibitors. Overexpression of Cas or FAK further enhances invadopodia activity in cells plated on rigid polyacrylamide substrates. Thus, in invasive cells, ECM rigidity signals lead to increased matrix-degrading activity at invadopodia, via a myosin II-FAK/Cas pathway. These data suggest a potential mechanism, via invadopodia, for the reported correlation of tissue density with cancer aggressiveness. PMID:18718759

Parekh, Aron; Clark, Emily S.; Iwueke, Izuchukwu C.; Guelcher, Scott A.

2008-01-01

403

Typicality in random matrix product states  

SciTech Connect

Recent results suggest that the use of ensembles in statistical mechanics may not be necessary for isolated systems, since typically the states of the Hilbert space would have properties similar to those of the ensemble. Nevertheless, it is often argued that most of the states of the Hilbert space are nonphysical and not good descriptions of realistic systems. Therefore, to better understand the actual power of typicality it is important to ask if it is also a property of a set of physically relevant states. Here we address this issue, studying if and how typicality emerges in the set of matrix product states. We show analytically that typicality occurs for the expectation value of subsystems' observables when the rank of the matrix product state scales polynomially with the size of the system with a power greater than 2. We illustrate this result numerically and present some indications that typicality may appear already for a linear scaling of the rank of the matrix product state.

Garnerone, Silvano; Oliveira, Thiago R. de; Zanardi, Paolo [Department of Physics and Astronomy and Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, California 90089 (United States)

2010-03-15

404

Gas chromatography/matrix-isolation apparatus  

DOEpatents

A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one reflecting surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the reflecting surface which is maintained at a sufficiently low temperature to cause solidification. A first parabolic mirror directs an incident beam of electromagnetic radiation, such as in the infrared (IR) spectrum, from a source onto the sample/matrix mixture while a second parabolic mirror directs a second beam of electromagnetic radiation reflected by the specular surface to an IR spectrometer for determining the absorption spectra of the sample material deposited on the reflecting surface. The pair of off-axis parabolic mirrors having a common focal point are positioned outside of the vacuum chamber and may be displaced in combination for improved beam positioning and alignment. The carousel is provided with an aperture for each reflecting surface to facilitate accurate positioning of the incident beam relative to the gas-samples under analysis. Improved gas-sample deposition is insured by the use of a long focal length stereomicroscope positioned outside of the vacuum chamber for monitoring sample formation through a window, while the sample collector is positioned outside of the zone bounded by the incident and reflected electromagnetic beams for improved sample access and monitoring.

Reedy, Gerald T. (411 Francis St., Bourbonnais, IL 60914)

1986-01-01

405

Matrix metalloproteinase gene polymorphisms and oral cancer  

PubMed Central

Since oral squamous cell carcinoma (OSCC) is the most prevalent malignant cancer in the oral cavity, several researches have been performed to study the role of important enzymes in this disease. Among them, the matrix metalloproteinases (MMPs) are highlighted, due to the fact that they are proteinases responsible to degrade many extra-cellular matrix components, making possible the invasion of neoplasic cells. Important tools in cancer prognosis have been utilized aiming to correlate high levels of MMPs and OSCC, such as immunohistochemical, zymographic and mRNA detection methods. However, these techniques are usually applied after cancer detection, characterizing a curative but not a preventive medicine. Trying to make interventions before the development of the disease and making possible the identification of people at high risk and, analysis of modifications in MMP genes has been a chance for modern medicine. Recently, polymorphisms in MMP genes have been related to different neoplasias, including OSCC. Despite investigation is beginning, MMP gene polymorphisms seems to have a promising future in oral cancer research and some of the present results have shown that there are MMP polymorphisms related to an increased risk for developing oral cancer. Key words:Oral cancer, polymorphism, matrix metalloproteinase. PMID:24455039

Dias do Carmo, Elaine; Dias da Silva, Marco A.; Blumer Rosa, Luiz E.

2012-01-01

406

QCD, Chiral Random Matrix Theory and Integrability  

E-print Network

Random Matrix Theory has been a unifying approach in physics and mathematics.In these lectures we discuss applications of Random Matrix Theory to QCD and emphasize underlying integrable structures. In the first lecture we give an overview of QCD, its low-energy limit and the microscopic limit of the Dirac spectrum which, as we will see in the second lecture, can be described by chiral Random Matrix Theory. The main topic of the third lecture is the recent developments on the relation between the QCD partition function and integrable hierarchies (in our case the Toda lattice hierarchy). This is an efficient way to obtain the QCD Dirac spectrum from the low energy limit of the QCD partition function. Finally, we will discuss the QCD Dirac spectrum at nonzero chemical potential. We will show that the microscopic spectral density is given by the replica limit of the Toda lattice equation. Recent results by Osborn on the Dirac spectrum of full QCD will be discussed.

J. J. M. Verbaarschot

2005-02-02

407

Analyticity and the Holographic S-Matrix  

SciTech Connect

We derive a simple relation between the Mellin amplitude for AdS/CFT correlation functions and the bulk S-Matrix in the flat spacetime limit, proving a conjecture of Penedones. As a consequence of the Operator Product Expansion, the Mellin amplitude for any unitary CFT must be a meromorphic function with simple poles on the real axis. This provides a powerful and suggestive handle on the locality vis-a-vis analyticity properties of the S-Matrix. We begin to explore analyticity by showing how the familiar poles and branch cuts of scattering amplitudes arise from the holographic description. For this purpose we compute examples of Mellin amplitudes corresponding to 1-loop and 2-loop Witten diagrams in AdS. We also examine the flat spacetime limit of conformal blocks, implicitly relating the S-Matrix program to the Bootstrap program for CFTs. We use this connection to show how the existence of small black holes in AdS leads to a universal prediction for the conformal block decomposition of the dual CFT.

Fitzpatrick, A.Liam; /Stanford U., Phys. Dept.; Kaplan, Jared; /SLAC

2012-04-03

408

Google matrix, dynamical attractors, and Ulam networks  

NASA Astrophysics Data System (ADS)

We study the properties of the Google matrix generated by a coarse-grained Perron-Frobenius operator of the Chirikov typical map with dissipation. The finite-size matrix approximant of this operator is constructed by the Ulam method. This method applied to the simple dynamical model generates directed Ulam networks with approximate scale-free scaling and characteristics being in certain features similar to those of the world wide web with approximate scale-free degree distributions as well as two characteristics similar to the web: a power-law decay in PageRank that mirrors the decay of PageRank on the world wide web and a sensitivity to the value ? in PageRank. The simple dynamical attractors play here the role of popular websites with a strong concentration of PageRank. A variation in the Google parameter ? or other parameters of the dynamical map can drive the PageRank of the Google matrix to a delocalized phase with a strange attractor where the Google search becomes inefficient.

Shepelyansky, D. L.; Zhirov, O. V.

2010-03-01

409

Design, set up, and testing of a matrix acidizing apparatus  

E-print Network

to dissolution pattern of the matrix. The standard acid treatments are HCl mixtures to dissolve carbonate minerals and HCl- HF formulations to attack those plugging minerals, mainly silicates (clays and feldspars). A matrix acidizing apparatus for conducting...

Nevito Gomez, Javier

2006-10-30

410

Styrene-Terminated Polysulfone Oligomers As Matrix Materials  

NASA Technical Reports Server (NTRS)

Report summarizes preliminary experimental study and evaluation of styrene-terminated polysulfone oligomers as matrix materials in graphite-fiber/matrix composites. Composites evaluated in terms of methods of fabrication and of mechanical properties.

Bowles, Kenneth J.; Vannucci, Raymond D.

1993-01-01

411

New fractional matrix with its applications in image encryption  

NASA Astrophysics Data System (ADS)

In this paper, new fractional matrix generation by using different the periodic matrix sequences are considered. For a periodic matrix with period P, its integer forms and fractional forms can constitute different periodic matrix sequences. The series of the periodic matrix sequence can be used to compute and construct different fractional matrices, which is depended on the relationship between the period and the size of the periodic matrix sequence. The proposed fractional matrix generation method is general and can be used to any periodic matrices. Then, we extend the new fractional matrices to multi-order forms, which can be used in image encryption. Simulation results and the application example in image encryption using the obtained new fractional matrix are also presented.

Zhang, Feng; Hu, Yang; Tao, Ran; Wang, Yue

2014-12-01

412

Matrix probing, skeleton decompositions, and sparse Fourier transform  

E-print Network

In this thesis, we present three different randomized algorithms that help to solve matrices, compute low rank approximations and perform the Fast Fourier Transform. Matrix probing and its conditioning When a matrix A with ...

Chiu, Jiawei

2013-01-01

413

Contradiction of the DENSITY MATRIX notion in quantum mechanics  

E-print Network

It is shown that description of a nonpolarized neutron beam by density matrix is contradictory. Density matrix is invariant with respect to choice of quantization axis, while experimental devices can discriminate between different quantization axes.

V. K. Ignatovich

2012-04-04

414

Elongated Polyproline Motifs Facilitate Enamel Evolution through Matrix Subunit Compaction  

E-print Network

Elongated Polyproline Motifs Facilitate Enamel Evolution through Matrix Subunit Compaction Tianquan mineral component of relatively light-weight, articulated endoskeletons and sophisticated tooth, Dangaria S, Walker C, et al. (2009) Elongated Polyproline Motifs Facilitate Enamel Evolution through Matrix

Braatz, Richard D.

415

Optimized Jacobian Matrix Solution of a generalized electric power network  

E-print Network

~NOES VITA 52 54 LIST OF TABIZS Table gauss-Seidel and Newton 1'iethod Comparison Page Viii LIST OF FIGUHES Figure Page 1. Sample 7-node network 2. Example network 19 Connection matrix For Figure 2 19 4 Penumbered connection matrix using version... 1 optimization 20 Penumbered connection matrix using version 2 cntf mization . . . ~ . . ~ . - - ~ ~ ~ ~ ~ 1 J connection matrix with no optimization I J connecticn ma. trix with version 1 optimization I J connect f on matrf x with version 2...

Moore, Jimmie Archer

2012-06-07

416

On the Singularly Perturbed Matrix Differential Riccati Equation  

Microsoft Academic Search

In this paper, the finite-time optimal control problem for time-invariant linear singularly perturbed systems is considered. The reduced-order pure-slow and pure-fast matrix differential Riccati equations are obtained by decoupling the singularly perturbed differential matrix Riccati equation of dimension n1+ n2into the regular differential matrix Riccati equation pure-slow of dimension n1and the stiff differential matrix Riccati equation pure-fast of dimension n2.

Zoran Gajic; Sarah Koskie; Cyril Coumarbatch

2005-01-01

417

General Solution of the Stieltjes Truncated Matrix Moment Problem  

Microsoft Academic Search

The description of all solutions of the truncated Stieltjes matrix moment problem consisting in finding all s × s matrix measures d? (t) on [0,?) with given first 2n+1 power s×s matrix moments (Cj)j=0n is obtained in a general case, when the block Hankel matrix ?n ? (Cj+k)j,k=0n may be non-invertible. Special attention is paid to the description of canonical

Vadim M. Adamyan; Igor M. Tkachenko

418

Discrete Time Transfer Matrix Method for Multibody System Dynamics  

Microsoft Academic Search

A new method for multibody system dynamics is proposed in this paper. This method, named as discrete time transfer matrix\\u000a method of multibody system (MS-DT-TMM), combines and expands the advantages of the transfer matrix method (TMM), transfer\\u000a matrix method of vibration of multibody system (MS-TMM), discrete time transfer matrix method (DT-TMM) and the numerical integration\\u000a procedure. It does not need

Xiaoting Rui; Bin He; Yuqi Lu; Wenguang Lu; Guoping Wang

2005-01-01

419

String coupling and interactions in type IIB matrix model  

SciTech Connect

We investigate the interactions of closed strings in a IIB matrix model. The basic interaction of the closed superstring is realized by the recombination of two intersecting strings. Such interaction is investigated in a IIB matrix model via two-dimensional noncommutative gauge theory in the IR limit. By estimating the probability of the recombination, we identify the string coupling g{sub s} in the IIB matrix model. We confirm that our identification is consistent with matrix string theory.

Kitazawa, Yoshihisa [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Department of Particle and Nuclear Physics, The Graduate University for Advanced Studies, Tsukuba, Ibaraki 305-0801 (Japan); Nagaoka, Satoshi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan)

2009-05-15

420

The UDUTDecomposition of Manipulator Inertia Matrix Subir Kumar Saha  

E-print Network

The UDUTDecomposition of Manipulator Inertia Matrix Subir Kumar Saha R&D Center, Toshiba.uki.rdc.toshiba.co.jp Abstract In this paper, the UDUT decomposition of the gen- eralized inertia matrix of an n-link serial to a modified Gaussian elimination, are introduced, whereas each element of the inertia matrix is written

Saha, Subir Kumar

421

Condition and Error Estimates in Numerical Matrix Computations  

SciTech Connect

This tutorial paper deals with sensitivity and error estimates in matrix computational processes. The main factors determining the accuracy of the result computed in floating--point machine arithmetics are considered. Special attention is paid to the perturbation analysis of matrix algebraic equations and unitary matrix decompositions.

Konstantinov, M. M. [University of Architecture, Civil Engineering and Geodesy, 1046 Sofia (Bulgaria); Petkov, P. H. [Technical University of Sofia, 1000 Sofia (Bulgaria)

2008-10-30

422

Google matrix analysis of directed networks Leonardo Ermann  

E-print Network

Google matrix analysis of directed networks Leonardo Ermann Departamento de F�isica Te�orica, GIy network structures and characteristics. This review describes the Google matrix analysis of directed III. Construction of Google matrix and its properties 3 A. Construction rules 3 B. Markov chains

Shepelyansky, Dima

423

Symmetric nonsquare factorization of selfadjoint rational matrix functions  

E-print Network

Symmetric nonsquare factorization of selfadjoint rational matrix functions and algebraic Riccati is then determined by a solution to a certain algebraic Riccati inequality. We shall also consider the case where for the rational matrix function W() if there is a matrix B such that W() - C(I - A)-1 B 2 #12;is analytic over

Ran, André

424

Hot isostatic pressing of metal reinforced metal matrix composites  

Microsoft Academic Search

Metal reinforced Metal Matrix Composites (MMMCs) made by combining an aluminium alloy matrix with stainless steel reinforcing wires are potentially cheaper and tougher than continuous fibre ceramic reinforced Metal Matrix Composites (MMCs). Although they do not give as great enhancements in stiffness and strength, worthwhile gains are achieved. Such MMMCs can be produced by Hot Isostatic Pressing (HIPping), which reduces

A. L. FILHO; H. ATKINSON; H. JONES; E. DE LOS RIOS; S. KING

1998-01-01

425

Higher order graviton scattering in M(atrix) theory  

Microsoft Academic Search

In matrix theory the effective action for graviton-graviton scattering is a double expansion in the relative velocity and inverse separation. We discuss the systematics of this expansion and subject matrix theory to a new test. Low-energy supergravity predicts the coefficient of the v6\\/r14 term, a two-loop effect, in agreement with explicit matrix model calculations.

Katrin Becker; Melanie Becker; Joseph Polchinski; Arkady Tseytlin

1997-01-01

426

Simulation of Ductile Damage in Metal Matrix Composites  

Microsoft Academic Search

Particle and fiber reinforced ductile matrix composites are subject to a number of damage modes on the microscale, one of which is ductile failure of the matrix. In the present study Finite Element based micromechanical models that employ unit cells with appropriate material descriptions for the matrix are discussed in view on investigating this behavior. Among the most important continuum

T. Drabek; H. J. Böhm

2004-01-01

427

A SINGULAR VALUE THRESHOLDING ALGORITHM FOR MATRIX COMPLETION  

E-print Network

as in the task of recovering a large matrix from a small subset of its entries (the famous Netflix problem). Off like to infer their preference for unrated items; this is the famous Netflix problem [1]. Recovering, the matrix we wish to recover has low rank or ap- proximately low rank. For instance, the Netflix data matrix

Candes, Emmanuel J.

428

Kernelized Bayesian Matrix Factorization Mehmet Gonen 1,2  

E-print Network

information into a probabilis- tic matrix factorization model using topic models to generate latent componentsKernelized Bayesian Matrix Factorization Mehmet G¨onen 1,2 mehmet.gonen@aalto.fi Suleiman A. Khan 1 Science, University of Helsinki Abstract We extend kernelized matrix factorization with a fully Bayesian

Kaski, Samuel

429

The linear algebra of the generalized Pascal functional matrix  

Microsoft Academic Search

In this paper we generalize Pascal's matrix by defining the polynomials “Factorial Binomial”. Then using this generalization, we introduce a two-variable Pascal's matrix and state its related theorems and prove them. Finally we introduce Pascal's functional matrix associated with a sequence a={an}n?0, and obtain several important combinatorial identities.

M. Bayat; H. Teimoori

1999-01-01

430

Optimization of Sparse Matrix Kernels for Data Mining  

E-print Network

called Sparsity to automatically generate an optimized sparse matrix­vector multiplication routineOptimization of Sparse Matrix Kernels for Data Mining Eun­Jin Im and Katherine Yelick Computer)642­1266 Fax: (510)642­5775 Abstract Number: 193 #12; Optimization of Sparse Matrix Kernels for Data Mining Eun

Yelick, Katherine

431

A Relational Approach to the Compilation of Sparse Matrix Programs ?  

E-print Network

of the sparse matrix. We present experi- mental data that demonstrates that the code generated by our compilerA Relational Approach to the Compilation of Sparse Matrix Programs ? Vladimir Kotlyar, Keshav for compil- ing e cient sparse matrix code from dense DO-ANY loops and a spec- i cation of the representation

Pingali, Keshav K.

432

Parallel Prefix Adder Design with Matrix Representation Youngmoon Choi  

E-print Network

-lists of the carry propagation graph are generated from the matrix representation for spice delay calculation the matrixes. These produce a one-shot batch process that generates the complete set of characteristic curvesParallel Prefix Adder Design with Matrix Representation Youngmoon Choi Sun Microsystems, Inc. 5300

California at Davis, University of

433

Large Gaussian Covariance Matrix Estimation with Markov Structures1  

E-print Network

. The proposed methods exploit sparsity in the inverse covariance matrix in a systematic fashion so that the estimate conforms with models of Markov structure and is amenable for subsequent stochastic modeling com- bination of the sample covariance matrix and the identity matrix. Bayesian treatment

Deng, Xinwei

434

Spectral averaging techniques for Jacobi matrices with matrix entries  

E-print Network

A Jacobi matrix with matrix entries is a self-adjoint block tridiagonal matrix with invertible blocks on the off-diagonals. Averaging over boundary conditions leads to explicit formulas for the averaged spectral measure which can potentially be useful for spectral analysis. Furthermore another variant of spectral averaging over coupling constants for these operators is presented.

Christian Sadel; Hermann Schulz-Baldes

2009-02-11

435

Diagnostic value of nonlinear optical signals from collagen matrix  

E-print Network

Diagnostic value of nonlinear optical signals from collagen matrix in the detection of epithelial is to investigate the relationship between the nonlinear optical signals from the collagen matrix in stroma. © 2011 Optical Society of America OCIS codes: 170.4580, 170.4730, 180.4315, 170.6930. Collagen matrix

Qu, Jianan

436

High Strain Rate Deformation Modeling of a Polymer Matrix Composite. Part 1; Matrix Constitutive Equations  

NASA Technical Reports Server (NTRS)

Recently applications have exposed polymer matrix composite materials to very high strain rate loading conditions, requiring an ability to understand and predict the material behavior under these extreme conditions. In this first paper of a two part report, background information is presented, along with the constitutive equations which will be used to model the rate dependent nonlinear deformation response of the polymer matrix. Strain rate dependent inelastic constitutive models which were originally developed to model the viscoplastic deformation of metals have been adapted to model the nonlinear viscoelastic deformation of polymers. The modified equations were correlated by analyzing the tensile/ compressive response of both 977-2 toughened epoxy matrix and PEEK thermoplastic matrix over a variety of strain rates. For the cases examined, the modified constitutive equations appear to do an adequate job of modeling the polymer deformation response. A second follow-up paper will describe the implementation of the polymer deformation model into a composite micromechanical model, to allow for the modeling of the nonlinear, rate dependent deformation response of polymer matrix composites.

Goldberg, Robert K.; Stouffer, Donald C.

1998-01-01

437

Chondrites: The Compaction of Fine Matrix and Matrix-like Chondrule Rims  

NASA Astrophysics Data System (ADS)

Primitive chondritic meteorites mainly consist of chondrules, sulfide+/-metal, and fine-grained matrix. The most unequilibrated chondrites preserve in their phase compositions and, to a lesser degree, their textures, many details about processes that occurred in the solar nebula. On the other hand, much of the textural evidence records processes that occurred in or on the parent body. I suggest that the low-porosity of chondrule matrix and matrix-like rims reflects compaction processes that occurred in asteroid-size bodies, and that neither matrix lumps nor compact matrix-like rims on chondrules could have achieved their observed low porosities in the solar nebula. Recent theoretical studies by Donn and Meakin (1) and Chokshi et al. (2) have concluded that grain-grain sticking in the solar nebula mainly produces fluffy structures having very high porosities (probably >>50%). If these structures grow large enough, they can provide an aerogel-like matrix that can trap chondrules as well as metal and sulfide grains, and thus form suitable precursors of chondritic meteorites. However, the strength of any such structure formed in the solar nebula must be a trivial fraction of that required to survive passage through the Earth's atmosphere in order to fall as a meteorite. The best evidence of accretionary structures appears to be that reported by Metzler et al. (3). They made SEM images of entire thin sections of CM chondrites, and showed that, in the best preserved chondrites, rims are present on all entitities--on chondrules, chondrule fragments, refractory inclusions, etc. A study by Krot and Wasson (4) shows a more complex situation in ordinary chondrites. Although matrix is common, a sizable fraction of chondrules are not surrounded by matrix-like rims. As summarized by Rubin and Krot (1995), there are reports of small textural and compositional differences between matrix lumps and mean matrix-like chondrule rims, but there is so much overlap in properties between these two classes that I will assume that they can be treated as parts of a single statistical population. Published SEM images of matrix lumps and matrix-like rims show them to be relatively compact. Although some porosity is surely present as indicated by broad-beam electron-probe analysis totals <100%, it never reaches values comparable to those expected from low-velocity collisions in the solar nebula. Most chondrite researchers seem to hold that the low porosities reflect efficient packing of each grain as it accreted to the assemblage (i.e., as micrometer-size grains gradually covered the surface of a chondrule to form the matrix-like rim). I find this process very difficult to envision. If the velocities are low, the fluffy structures of Dodd and Meakin (1) should result; if the velocities are high, then rim erosion would seem to be more probable than growth. A possible scenario that avoids this dilemma is to form cm to m-size fluffy structures in low-turbulence regions of the nebular midplane. During accretion of these larger objects these experienced enough compaction to form tough, low-porosity (but unequilibrated) chondrites. If no chondrules were in a region, matrix lumps formed; if chondrules were widely separated, a matrix-like rim resulted. And, if chondrules were close to other chondrules or chondrule fragments, only small amounts of intervening fine-grained materials now separate them from their neighbors. During the compaction event, gas and dust migration occurred, and matrix filled all interstices, as now observed in the most primitive chondrites. According to this picture there could have been more diversity in the fine-grained nebular component before compaction occurred. These differences would be best preserved in matrix-like rims and matrix lumps. Much of the interchondrule matrix should consist of homogenized dust that was mixed during compaction-induced transport. References: [1] Donn B. and Meakin P. (1989) Proc. LPSC 19th, 577-580. [2] Chokshi A. et al. (1993) Astrophys. J., 407, 806-819. [3] Metzler K. et al. (1992) GCA,

Wasson, J. T.

1995-09-01

438

Linear scaling computation of the Fock matrix. VII. Parallel computation of the Coulomb matrix.  

PubMed

We present parallelization of a quantum-chemical tree-code for linear scaling computation of the Coulomb matrix. Equal time partition is used to load balance computation of the Coulomb matrix. Equal time partition is a measurement based algorithm for domain decomposition that exploits small variation of the density between self-consistent-field cycles to achieve load balance. Efficiency of the equal time partition is illustrated by several tests involving both finite and periodic systems. It is found that equal time partition is able to deliver 91%-98% efficiency with 128 processors in the most time consuming part of the Coulomb matrix calculation. The current parallel quantum chemical tree code is able to deliver 63%-81% overall efficiency on 128 processors with fine grained parallelism (less than two heavy atoms per processor). PMID:15473715

Gan, Chee Kwan; Tymczak, C J; Challacombe, Matt

2004-10-01

439

Gas chromatography/matrix-isolation apparatus  

DOEpatents

A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one reflecting surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the reflecting surface which is maintained at a sufficiently low temperature to cause solidification. A first parabolic mirror directs an incident beam of electromagnetic radiation, such as in the infrared (IR) spectrum, from a source onto the sample/matrix mixture while a second parabolic mirror directs a second beam of electromagnetic radiation reflected by the specular surface to an IR spectrometer for determining the absorption spectra of the sample material deposited on the reflecting surface. The pair of off-axis parabolic mirrors having a common focal point are positioned outside of the vacuum chamber and may be displaced in combination for improved beam positioning and alignment. The carousel is provided with an aperture for each reflecting surface to facilitate accurate positioning of the incident beam relative to the gas-samples under analysis. Improved gas-sample deposition is insured by the use of a long focal length stereomicroscope positioned outside of the vacuum chamber for monitoring sample formation through a window, while the sample collector is positioned outside of the zone bounded by the incident and reflected electromagnetic beams for improved sample access and monitoring. 10 figs.

Reedy, G.T.

1986-06-10

440

Curing of epoxy matrix composite in stratosphere  

NASA Astrophysics Data System (ADS)

Large structures for habitats, greenhouses, space bases, space factories are needed for next stage of space exploitation. A new approach enabling large-size constructions in space relies on the use of the polymerization technology of fiber-filled composites with a curable polymer matrix applied in the free space environment. The polymerisation process is proposed for the material exposed to high vacuum, dramatic temperature changes, space plasma, sun irradiation and atomic oxygen (in low Earth orbit), micrometeorite fluence, electric charging and microgravitation. The stratospheric flight experiments are directed to an investigation of the curing polymer matrix under the stratospheric conditions on. The unique combination of low atmospheric pressure, high intensity UV radiation including short wavelength UV and diurnal temperature variations associated with solar irradiation strongly influences the chemical processes in polymeric materials. The first flight experiment with uncured composites was a part of the NASA scientific balloon flight program realised at the NASA stratospheric balloon station in Alice Springs, Australia. A flight cassette installed on payload was lifted with a “zero-pressure” stratospheric balloon filled with Helium. Columbia Scientific Balloon Facility (CSBF) provided the launch, flight telemetry and landing of the balloon and payload. A cassette of uncured composite materials with an epoxy resin matrix was exposed 3 days in the stratosphere (40 km altitude). The second flight experiment was realised in South Australia in 2012, when the cassette was exposed in 27 km altitude. An analysis of the chemical structure of the composites showed, that the space irradiations are responsible for crosslinking of the uncured polymers exposed in the stratosphere. The first prepreg in the world was cured successfully in stratosphere. The investigations were supported by Alexander von Humboldt Foundation, NASA and RFBR (12-08-00970) grants.

Kondyurin, Alexey; Kondyurina, Irina; Bilek, Marcela

441

Effective Dynamics of the Matrix Big Bang  

E-print Network

We study the leading quantum effects in the recently introduced Matrix Big Bang model. This amounts to a study of supersymmetric Yang-Mills theory compactified on the Milne orbifold. We find a one-loop potential that is attractive near the Big Bang. Surprisingly, the potential decays very rapidly at late times, where it appears to be generated by D-brane effects. Usually, general covariance constrains the form of any effective action generated by renormalization group flow. However, the form of our one-loop potential seems to violate these constraints in a manner that suggests a connection between the cosmological singularity and long wavelength, late time physics.

Ben Craps; Arvind Rajaraman; Savdeep Sethi

2006-01-10

442

Effective dynamics of the matrix big bang  

SciTech Connect

We study the leading quantum effects in the recently introduced matrix big bang model. This amounts to a study of supersymmetric Yang-Mills theory compactified on the Milne orbifold. We find a one-loop potential that is attractive near the big bang. Surprisingly, the potential decays very rapidly at late times where it appears to be generated by D-brane effects. Usually, general covariance constrains the form of any effective action generated by renormalization group flow. However, the form of our one-loop potential seems to violate these constraints in a manner that suggests a connection between the cosmological singularity and long wavelength, late time physics.

Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Rajaraman, Arvind [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Sethi, Savdeep [Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)

2006-05-15

443

Parallel partitioned-inverse sparse matrix solutions  

SciTech Connect

The partitioned inverse method has been demonstrated to be quite effective for parallel sparse matrix solutions on massively parallel machines. Though experiments on CM-2 have illustrated the advantage of using partitions, Intel iPSC/860 multiprocessor only favors fewer and denser partitions, particularly in the case of extremely sparse matrices. Different decomposition and communication algorithms are investigated here on the iPSC/860 to improve the performance. The decomposition is done in an interleave fashion in two different directions (row-wise and column-wise). The need for synchronization due to the interchange of intermediate solution vectors makes load balancing an important factor in obtaining an optimum performance.

Dag, H.; Yasar, O.; Alvarado, F. [Univ. of Wisconsin, Madison, WI (United States)

1993-12-31

444

Mueller matrix of a dicot leaf  

NASA Astrophysics Data System (ADS)

A better understanding of the information contained in the spectral, polarized bidirectional reflectance and transmittance of leaves may lead to improved techniques for identifying plant species in remotely sensed imagery as well as better estimates of plant moisture and nutritional status. Here we report an investigation of the optical polarizing properties of several leaves of one species, Cannabis sativa, represented by a 3x3 Mueller matrix measured over the wavelength region 400-2,400 nm. Our results support the hypothesis that the leaf surface alters the polarization of incident light - polarizing off nadir, unpolarized incident light, for example - while the leaf volume tends to depolarized incident polarized light.

Vanderbilt, Vern C.; Daughtry, Craig S. T.

2012-06-01

445

Cosmology and the S-matrix  

SciTech Connect

We study conditions for the existence of asymptotic observables in cosmology. With the exception of de Sitter space, the thermal properties of accelerating universes permit arbitrarily long observations, and guarantee the production of accessible states of arbitrarily large entropy. This suggests that some asymptotic observables may exist, despite the presence of an event horizon. Comparison with decelerating universes shows surprising similarities: Neither type suffers from the limitations encountered in de Sitter space, such as thermalization and boundedness of entropy. However, we argue that no realistic cosmology permits the global observations associated with an S-matrix.

Bousso, Raphael

2005-01-25

446

Development of Matrix Microstructures in UHTC Composites  

NASA Technical Reports Server (NTRS)

One of the major issues hindering the use of ultra high temperature ceramics for aerospace applications is low fracture toughness. There is considerable interest in developing fiber-reinforced composites to improve fracture toughness. Considerable knowledge has been gained in controlling and improving the microstructure of monolithic UHTCs, and this paper addresses the question of transferring that knowledge to composites. Some model composites have been made and the microstructures of the matrix developed has been explored and compared to the microstructure of monolithic materials in the hafnium diboride/silicon carbide family. Both 2D and 3D weaves have been impregnated and processed.

Johnson, Sylvia; Stackpoole, Margaret; Gusman, Michael

2012-01-01

447

A Random Matrix Approach to Credit Risk  

PubMed Central

We estimate generic statistical properties of a structural credit risk model by considering an ensemble of correlation matrices. This ensemble is set up by Random Matrix Theory. We demonstrate analytically that the presence of correlations severely limits the effect of diversification in a credit portfolio if the correlations are not identically zero. The existence of correlations alters the tails of the loss distribution considerably, even if their average is zero. Under the assumption of randomly fluctuating correlations, a lower bound for the estimation of the loss distribution is provided. PMID:24853864

Guhr, Thomas

2014-01-01

448

Zero minors of the neutrino mass matrix  

SciTech Connect

We examine the possibility that a certain class of neutrino mass matrices, namely, those with two independent vanishing minors in the flavor basis, regardless of being invertible or not, is sufficient to describe current data. We compute generic formulas for the ratios of the neutrino masses and for the Majorana phases. We find that seven textures with two vanishing minors can accommodate the experimental data. We present an estimate of the mass matrix for these patterns. All of the possible textures can be dynamically generated through the seesaw mechanism augmented with a discrete Abelian symmetry.

Lashin, E. I. [Abdus Salam ICTP, P.O. Box 586, 34100 Trieste (Italy); Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Department of Physics and Astronomy, College of Science, King Saud University, Riyadh (Saudi Arabia); Chamoun, N. [Abdus Salam ICTP, P.O. Box 586, 34100 Trieste (Italy); Physics Department, HIAST, P.O. Box 31983, Damascus (Syrian Arab Republic)

2008-10-01

449

Metal matrix composites for aircraft propulsion systems  

NASA Technical Reports Server (NTRS)

Studies of advanced aircraft propulsion systems have indicated that performance gains and operating costs are possible through the application of metal matrix composites. Compressor fan blades and turbine blades have been identified as components with high payoff potential as a result of these studies. This paper will present the current status of development of five candidate materials for such applications. Boron fiber/aluminum, boron fiber/titanium, and silicon carbide fiber/titanium composites are considered for lightweight compressor fan blades. Directionally solidified eutectic superalloy and tungsten wire/superalloy composites are considered for application to turbine blades for use temperatures to 1100 C (2000 F).

Signorelli, R. A.

1975-01-01

450

Microfracture in high temperature metal matrix laminates  

NASA Technical Reports Server (NTRS)

Computational simulation procedures are described to evaluate the composite microfracture behavior, establish the hierarchy/sequence of fracture modes, and the influence of compliant layers and partial debonding on composite properties and microfracture initiation. These procedures are based upon three-dimensional finite element analysis and composite micromechanics equations. Typical results for the effects of compliant layers and partial debonding, microfracture initiation, and propagation and the thermomechanical cyclic loading on a SiC/Ti15 composite system are presented and discussed. The results show that interfacial debonding follows fiber or matrix fracture, and the thermomechanical cyclic loading severely degrades the composite integrity.

Mital, Subodh K.; Chamis, Christos C.; Gotsis, Pascal K.

1991-01-01

451

The myoendothelial junction: breaking through the matrix?  

PubMed

Within the vasculature, specialized cellular extensions from endothelium (and sometimes smooth muscle) protrude through the extracellular matrix where they interact with the opposing cell type. These structures, termed myoendothelial junctions, have been cited as a possible key element in the control of several vascular physiologies and pathologies. This review will discuss observations that have led to a focus on the myoendothelial junction as a cellular integration point in the vasculature for both homeostatic and pathological conditions and as a possible independent signaling entity. We will also highlight the need for novel approaches to studying the myoendothelial junction in order to comprehend the cellular biology associated with this structure. PMID:19330678

Heberlein, Katherine R; Straub, Adam C; Isakson, Brant E

2009-05-01

452

Multithreading for synchronization tolerance in matrix factorization  

NASA Astrophysics Data System (ADS)

Physical constraints such as power, leakage and pin bandwidth are currently driving the HPC industry to produce systems with unprecedented levels of concurrency. In these parallel systems, synchronization and memory operations are becoming considerably more expensive than before. In this work we study parallel matrix factorization codes and conclude that they need to be re-engineered to avoid unnecessary (and expensive) synchronization. We propose the use of multithreading combined with intelligent schedulers and implement representative algorithms in this style. Our results indicate that this strategy can significantly outperform traditional codes.

Buttari, Alfredo; Dongarra, Jack; Husbands, Parry; Kurzak, Jakub; Yelick, Katherine

2007-07-01

453

Research on graphite reinforced glass matrix composites  

NASA Technical Reports Server (NTRS)

A broad group of fibers and matrices were combined to create a wide range of composite properties. Primary material fabrication procedures were developed which readily permit the fabrication of flat plate and shaped composites. Composite mechanical properties were measured under a wide range of test conditions. Tensile, flexure mechanical fatigue, thermal fatigue, fracture toughness, and fatigue crack growth resistance were evaluated. Selected fiber-matrix combinations were shown to maintain their strength at up to 1300 K when tested in an inert atmosphere. Composite high temperature mechanical properties were shown to be limited primarily by the oxidation resistance of the graphite fibers. Composite thermal dimensional stability was measured and found to be excellent.

Prewo, K. M.; Thompson, E. R.

1981-01-01

454

Universal Evolution of CKM Matrix Elements  

E-print Network

We derive the two-loop evolution equations for the Cabibbo-Kobayashi-Maskawa matrix. We show that to leading order in the mass and CKM hierarchies the scaling of the mixings $|V_{ub}|^2$, $|V_{cb}|^2$, $|V_{td}|^2$, $|V_{ts}|^2$ and of the rephase-invariant CP-violating parameter $J$ is universal to all orders in perturbation theory. In leading order the other CKM elements do not scale. Imposing the constraint $\\lambda _b=\\lambda _{\\tau}$ at the GUT scale determines the CKM scaling factor to be $\\simeq 0.58$ in the MSSM.

V. Barger; M. S. Berger; P. Ohmann

1992-10-23

455

Matrix Factorization for Transcriptional Regulatory Network Inference  

PubMed Central

Inference of Transcriptional Regulatory Networks (TRNs) provides insight into the mechanisms driving biological systems, especially mammalian development and disease. Many techniques have been developed for TRN estimation from indirect biochemical measurements. Although successful when initially tested in model organisms, these regulatory models often fail when applied to data from multicellular organisms where multiple regulation and gene reuse increase dramatically. Non-negative matrix factorization techniques were initially introduced to find non-orthogonal patterns in data, making them ideal techniques for inference in cases of multiple regulation. We review these techniques and their application to TRN analysis.

Ochs, Michael F.; Fertig, Elana J.

2013-01-01

456

Matrix factorization on a hypercube multiprocessor  

SciTech Connect

This paper is concerned with parallel algorithms for matrix factorization on distributed-memory, message-passing multiprocessors, with special emphasis on the hypercube. Both Cholesky factorization of symmetric positive definite matrices and LU factorization of nonsymmetric matrices using partial pivoting are considered. The use of the resulting triangular factors to solve systems of linear equations by forward and back substitutions is also considered. Efficiencies of various parallel computational approaches are compared in terms of empirical results obtained on an Intel iPSC hypercube. 19 refs., 6 figs., 2 tabs.

Geist, G.A.; Heath, M.T.

1985-08-01

457

Electrophilic properties of common MALDI matrix molecules  

Microsoft Academic Search

The negative ion photoelectron spectra of the following MALDI matrix molecules have been measured: 3-carboxypyridine (nicotinic acid), 2,5-dihydroxybenzoic acid (DHB), 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid), 2,6-dihydroxyacetophenone (DHAP), 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid (ferulic acid), 3-hydroxy-2-pyridinecarboxylic acid (3HPA), and 2,6-pyridinedicarboxylic acid (dipicolinic acid). Adiabatic electron affinities and vertical detachment energies were extracted from these spectra and reported. In addition, electron affinities were calculated for DHAP,

T. P. Lippa; S. N. Eustis; D. Wang; K. H. Bowen

2007-01-01

458

A random matrix approach to credit risk.  

PubMed

We estimate generic statistical properties of a structural credit risk model by considering an ensemble of correlation matrices. This ensemble is set up by Random Matrix Theory. We demonstrate analytically that the presence of correlations severely limits the effect of diversification in a credit portfolio if the correlations are not identically zero. The existence of correlations alters the tails of the loss distribution considerably, even if their average is zero. Under the assumption of randomly fluctuating correlations, a lower bound for the estimation of the loss distribution is provided. PMID:24853864

Münnix, Michael C; Schäfer, Rudi; Guhr, Thomas

2014-01-01

459

Biology of the extracellular matrix: an overview.  

PubMed

The extracellular matrix (ECM) is an intricate network composed of an array of multidomain macromolecules organized in a cell/tissue-specific manner. Components of the ECM link together to form a structurally stable composite, contributing to the mechanical properties of tissues. The ECM is also a reservoir of growth factors and bioactive molecules. It is a highly dynamic entity that is of vital importance, determining and controlling the most fundamental behaviors and characteristics of cells such as proliferation, adhesion, migration, polarity, differentiation, and apoptosis. PMID:25275899

Yue, Beatrice

2014-01-01

460

Matrix metalloproteinase processing of signaling molecules to regulate inflammation.  

PubMed

Inflammation is a complex and highly regulated process that facilitates the clearance of pathogens and mediates tissue repair. Failure to resolve inflammation can lead to chronic inflammatory diseases such as periodontitis. Matrix metalloproteinases are generally thought to be detrimental in disease because degradation of extracellular matrix contributes to pathology. However, proteomic techniques (degradomics) are revealing that matrix metalloproteinases process a diverse array of substrates and therefore have a broad range of functions. Many matrix metalloproteinase substrates modulate inflammation and hence, by processing these proteins, matrix metalloproteinases can orchestrate the inflammatory response. PMID:23931058

Butler, Georgina S; Overall, Christopher M

2013-10-01

461

Strengthening and deformation mechanisms of discontinuous metal matrix composites  

SciTech Connect

The mechanism of strengthening in discontinuous metal matrix composites as proposed by Arsenault is reviewed and compared with the experimental data. This mechanism is based on the work hardening of the matrix as a result of the difference in the thermal coefficient of expansion ({Delta}CTE) of the reinforcement and the matrix. The consequence of the work hardening of the matrix due to {Delta}CTE was studied in terms of a finite element method and it was shown that deformation is more severe in the matrix where there is a cluster of the reinforcement.

Arsenault, R.J. [Univ. of Maryland, College Park (United States). Dept. of Materials and Nuclear Engineering

1993-12-31

462

Effect of the matrix on DNA electrophoretic mobility  

PubMed Central

DNA electrophoretic mobilities are highly dependent on the nature of the matrix in which the separation takes place. This review describes the effect of the matrix on DNA separations in agarose gels, polyacrylamide gels and solutions containing entangled linear polymers, correlating the electrophoretic mobilities with information obtained from other types of studies. DNA mobilities in various sieving media are determined by the interplay of three factors: the relative size of the DNA molecule with respect to the effective pore size of the matrix, the effect of the electric field on the matrix, and specific interactions of DNA with the matrix during electrophoresis. PMID:19100556

Stellwagen, Nancy C.; Stellwagen, Earle

2008-01-01

463

Development, implementation, and test results on integrated optics switching matrix  

NASA Technical Reports Server (NTRS)

A small integrated optics switching matrix, which was developed, implemented, and tested, indicates high performance. The matrix serves as a model for the design of larger switching matrices. The larger integrated optics switching matrix should form the integral part of a switching center with high data rate throughput of up to 300 megabits per second. The switching matrix technique can accomplish the design goals of low crosstalk and low distortion. About 50 illustrations help explain and depict the many phases of the integrated optics switching matrix. Many equations used to explain and calculate the experimental data are also included.

Rutz, E.

1982-01-01

464

Systems and methods for deactivating a matrix converter  

DOEpatents

Systems and methods are provided for deactivating a matrix conversion module. An electrical system comprises an alternating current (AC) interface, a matrix conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the matrix conversion module, and a control module. The control module is coupled to the matrix conversion module, and in response to a shutdown condition, the control module is configured to operate the matrix conversion module to deactivate the first conversion module when a magnitude of a current through the inductive element is less than a threshold value.

Ransom, Ray M.

2013-04-02

465

Matrix cracking in crossply ceramic matrix composites under quasi-static and cyclic loading  

SciTech Connect

Experimental data are presented for the development of 90[degree] ply and 0[degree] ply cracking in two crossply silicon carbide fiber/calcium aluminosilicate matrix laminates under quasi-static loading. Under mechanical fatigue loading it is found that there is an increase in ply crack densities and a corresponding laminate stiffness reduction with cycling. Possible mechanisms to account for these observations are proposed. A model is presented which describes the stress/strain behavior as a function of crack densities based on assumptions of frictional load transfer between fiber and matrix in the longitudinal plies and elastic bonding between the longitudinal and transverse plies.

Pryce, A.W.; Smith, P.A. (Univ. of Surrey (United Kingdom). Dept. of Materials Science and Engineering)

1994-03-01

466

The Matrix of Unitarity Triangle Angles for Quarks  

E-print Network

In the context of quark (as for lepton) mixing, we introduce the concept of the matrix of unitarity triangle angles $\\Phi$, emphasising that it carries equivalent information to the complex mixing matrix $V$ itself. The angle matrix $\\Phi$ has the added advantage, with respect to $V$, of being both basis-and phase-convention independent and consequently observable (indeed several $\\Phi$-matrix entries, eg. $\\Phi_{cs}=\\alpha$, $\\Phi_{us}=\\beta$ etc. are already long-studied as directly measurable/measured in $B$-physics experiments). We give complete translation formulae between the mixing-matrix and angle-matrix representations. We go on to consider briefly the present state of the experimental data on the full angle matrix and some of the prospects for the future, with reference to both the quark and lepton cases.

P. F. Harrison; S. Dallison; W. G. Scott

2009-04-20

467

Detecting Damage in Ceramic Matrix Composites Using Electrical Resistance  

NASA Technical Reports Server (NTRS)

The majority of damage in SiC/SiC ceramic matrix composites subjected to monotonic tensile loads is in the form of distributed matrix cracks. These cracks initiate near stress concentrations, such as 90 deg fiber tows or large matrix pores and continue to accumulate with additional stress until matrix crack saturation is achieved. Such damage is difficult to detect with conventional nondestructive evaluation techniques (immersion ultrasonics, x-ray, etc.). Monitoring a specimen.s electrical resistance change provides an indirect approach for monitoring matrix crack density. Sylramic-iBN fiber- reinforced SiC composites with a melt infiltrated (MI) matrix were tensile tested at room temperature. Results showed an increase in resistance of more than 500% prior to fracture, which can be detected either in situ or post-damage. A relationship between resistance change and matrix crack density was also determined.

Smith, Craig E.; Gyekenyesi, Andrew

2011-01-01

468

Detecting Cracks in Ceramic Matrix Composites by Electrical Resistance  

NASA Technical Reports Server (NTRS)

The majority of damage in SiC/SiC ceramic matrix composites subjected to monotonic tensile loads is in the form of distributed matrix cracks. These cracks initiate near stress concentrations, such as 90o fiber tows or large matrix pores and continue to accumulate with additional stress until matrix crack saturation is achieved. Such damage is difficult to detect with conventional nondestructive evaluation techniques (immersion ultrasonics, x-ray, etc.). Monitoring a specimen.s electrical resistance change provides an indirect approach for monitoring matrix crack density. Sylramic-iBN fiber- reinforced SiC composites with a melt infiltrated (MI) matrix were tensile tested at room temperature. Results showed an increase in resistance of more than 500% prior to fracture, which can be detected either in situ or post-damage. A relationship between resistance change and matrix crack density was also determined.

Smith, Craig; Gyekenyesi, Andrew

2011-01-01

469

Weak Matrix Elements and |Vcb| in HQEFT  

NASA Astrophysics Data System (ADS)

The heavy quark effective field theory (HQEFT) containing both effective ``quark fields'' and ``antiquark fields'' is investigated in detail. By integrating out (but not neglecting) the effective antiquark fields, we present a new formulation of effective theory which differs from the usual heavy quark effective theory (HQET) and exhibits valuable features because of the inclusion of the contributions from the antiquark fields. Matrix elements of vector and axial vector heavy quark currents between pseudoscalar and vector mesons containing a heavy quark (b or c) are then evaluated systematically up to the order of 1/m2Q and parametrized by a set of universal form factors. With a consistent normalization condition between the effective heavy hadron states, the form factors at zero recoil are related to the ground state meson masses, which enables us to estimate the values of form factors at zero recoil. In particular, Luke's theorem comes out automatically in the new formulation of HQEFT without the need of imposing the equation of motion iv? D Q+v=0. Consequently, the differential decay rates of both B-->D*l? and B-->Dl? do not receive 1/mQ order corrections at zero recoil, which is not the case in the usual HQET. Thus we quote that the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| can nicely be extracted from either of these two exclusive semileptonic decays at the order of 1/m2Q. Our estimates for |Vcb| are presented.

Wang, W. Y.; Wu, Y. L.; Yan, Y. A.

470

Google matrix of business process management  

NASA Astrophysics Data System (ADS)

Development of efficient business process models and determination of their characteristic properties are subject of intense interdisciplinary research. Here, we consider a business process model as a directed graph. Its nodes correspond to the units identified by the modeler and the link direction indicates the causal dependencies between units. It is of primary interest to obtain the stationary flow on such a directed graph, which corresponds to the steady-state of a firm during the business process. Following the ideas developed recently for the World Wide Web, we construct the Google matrix for our business process model and analyze its spectral properties. The importance of nodes is characterized by PageRank and recently proposed CheiRank and 2DRank, respectively. The results show that this two-dimensional ranking gives a significant information about the influence and communication properties of business model units. We argue that the Google matrix method, described here, provides a new efficient tool helping companies to make their decisions on how to evolve in the exceedingly dynamic global market.

Abel, M. W.; Shepelyansky, D. L.

2011-12-01

471

HOW MATRIX METALLOPROTEINASES REGULATE CELL BEHAVIOR  

PubMed Central

The matrix metalloproteinases (MMPs) constitute a multigene family of over 25 secreted and cell surface enzymes that process or degrade numerous pericellular substrates. Their targets include other proteinases, proteinase inhibitors, clotting factors, chemotactic molecules, latent growth factors, growth factor–binding proteins, cell surface receptors, cell-cell adhesion molecules, and virtually all structural extracellular matrix proteins. Thus MMPs are able to regulate many biologic processes and are closely regulated themselves. We review recent advances that help to explain how MMPs work, how they are controlled, and how they influence biologic behavior. These advances shed light on how the structure and function of the MMPs are related and on how their transcription, secretion, activation, inhibition, localization, and clearance are controlled. MMPs participate in numerous normal and abnormal processes, and there are new insights into the key substrates and mechanisms responsible for regulating some of these processes in vivo. Our knowledge in the field of MMP biology is rapidly expanding, yet we still do not fully understand how these enzymes regulate most processes of development, homeostasis, and disease. PMID:11687497

Sternlicht, Mark D.; Werb, Zena

2009-01-01

472

Matrix metalloproteinases in coronary artery disease.  

PubMed

Matrix metalloproteinases (MMP) are a family of zinc-containing endoproteinases that degrade extracellular matrix (ECM) components. MMP have important roles in the development, physiology and pathology of cardiovascular system. Metalloproteases also play key roles in adverse cardiovascular remodeling, atherosclerotic plaque formation and plaque instability, vascular smooth muscle cell (SMC) migration and restenosis that lead to coronary artery disease (CAD), and progressive heart failure. The study of MMP in developing animal model cardiovascular systems has been helpful in deciphering numerous pathologic conditions in humans. Increased peripheral blood MMP-2 and MMP-9 in acute coronary syndrome (ACS) may be useful as noninvasive tests for detection of plaque vulnerability. MMP function can be modulated by certain pharmacological drugs that can be exploited for treatment of ACS. CAD is a polygenic disease and hundreds of genes contribute toward its predisposition. A large number of sequence variations in MMP genes have been identified. Case-control association studies have highlighted their potential association with CAD and its clinical manifestations. Although results thus far are inconsistent, meta-analysis has demonstrated that MMP-3 Glu45Lys and MMP-9 1562C/T gene polymorphisms were associated with CAD risk. PMID:24938016

Mittal, Balraj; Mishra, Avshesh; Srivastava, Anshika; Kumar, Surendra; Garg, Naveen

2014-01-01

473

CITED2 mechanoregulation of matrix metalloproteinases.  

PubMed

Joint tissues are exquisitely sensitive to their mechanical environment. Indeed, mechanical loading may be the most important external factor regulating the development and long-term maintenance of joint tissues. Moderate mechanical loading maintains the integrity of articular cartilage, and under these conditions of homeostasis, matrix metalloproteinases (MMPs) are expressed at modest levels. However, both disuse and overuse can result in altered likely high levels of MMP expression, leading to cartilage degradation. The transcriptional regulator ED-rich tail 2 (CITED2) is expressed in chondrocytes in a load-dependent manner but in a pattern inversely related to that of MMPs. CITED2 mediates the moderate load-induced suppression of MMPs, possibly by competing with Ets-1, a known MMP transactivator, for binding to the co-activator p300, suggesting a mechanism for transcriptional suppression by CITED2. These findings suggest that CITED2 may act as a mechanosensitive molecular switch regulating cartilage matrix breakdown. This regulatory pathway could be exploited clinically to limit pathologic cartilage degradation. PMID:20392269

Sun, Hui B

2010-03-01

474

Membrane Associated Matrix Proteolysis and Heart Failure  

PubMed Central

The extracellular matrix (ECM) is a complex entity containing a large portfolio of structural proteins, signaling molecules, and proteases. Changes in the overall integrity and activational state of these ECM constituents can contribute to tissue structure and function, which is certainly true of the myocardium. Changes in the expression patterns and activational states of a family of ECM proteolytic enzymes, the matrix metalloproteinases (MMPs), have been identified in all forms of LV remodeling and can be a contributory factor for the progression to heart failure. However, new clinical and basic research has identified some surprising and unpredicted changes in MMP profiles in LV remodeling processes, such as with pressure or volume overload, as well as with myocardial infarction. From these studies, it has become recognized that proteolytic processing of signaling molecules by certain MMP types, particularly the transmembrane MMPs, may actually facilitate ECM accumulation as well as modulate fibroblast transdifferentiation – both critical events in adverse LV remodeling. Based upon the ever increasing substrates and diversity of biological actions of MMPs, it is likely that continued research regarding the relationship of LV remodeling to this family of proteases will yield new insights into the ECM remodeling process itself as well as new therapeutic targets. PMID:23287455

Spinale, Francis G.; Janicki, Joseph S.; Zile, Michael R.

2014-01-01

475

Discriminant Projective Non-Negative Matrix Factorization  

PubMed Central

Projective non-negative matrix factorization (PNMF) projects high-dimensional non-negative examples X onto a lower-dimensional subspace spanned by a non-negative basis W and considers WT X as their coefficients, i.e., X?WWT X. Since PNMF learns the natural parts-based representation Wof X, it has been widely used in many fields such as pattern recognition and computer vision. However, PNMF does not perform well in classification tasks because it completely ignores the label information of the dataset. This paper proposes a Discriminant PNMF method (DPNMF) to overcome this deficiency. In particular, DPNMF exploits Fisher's criterion to PNMF for utilizing the label information. Similar to PNMF, DPNMF learns a single non-negative basis matrix and needs less computational burden than NMF. In contrast to PNMF, DPNMF maximizes the distance between centers of any two classes of examples meanwhile minimizes the distance between any two examples of the same class in the lower-dimensional subspace and thus has more discriminant power. We develop a multiplicative update rule to solve DPNMF and prove its convergence. Experimental results on four popular face image datasets confirm its effectiveness comparing with the representative NMF and PNMF algorithms. PMID:24376680

Guan, Naiyang; Zhang, Xiang; Luo, Zhigang; Tao, Dacheng; Yang, Xuejun

2013-01-01

476

Raney distributions and random matrix theory  

E-print Network

Recent works have shown that the family of probability distributions with moments given by the Fuss-Catalan numbers permit a simple parameterized form for their density. We extend this result to the Raney distribution which by definition has its moments given by a generalization of the Fuss-Catalan numbers. Such computations begin with an algebraic equation satisfied by the Stieltjes transform, which we show can be derived from the linear differential equation satisfied by the characteristic polynomial of random matrix realizations of the Raney distribution. For the Fuss-Catalan distribution, an equilibrium problem characterizing the density is identified. The Stieltjes transform for the limiting spectral density of the singular values squared of the matrix product formed from $q$ inverse standard Gaussian matrices, and $s$ standard Gaussian matrices, is shown to satisfy a variant of the algebraic equation relating to the Raney distribution. Supported on $(0,\\infty)$, we show that it too permits a simple functional form upon the introduction of an appropriate choice of parameterisation. As an application, the leading asymptotic form of the density as the endpoints of the support are approached is computed, and is shown to have some universal features.

Peter J. Forrester; Dang-Zheng Liu

2014-04-23

477

Matrix error correction for digital data  

NASA Technical Reports Server (NTRS)

A technique for digital data error detection and correction is disclosed which adds alignment and checksum bytes to three sides of a matrix (24) of digital data to be protected. This technique is particularly used for the recording and storage (16,18) of digital data on video tape medium (14). The digital data is treated as a matrix block (24). Checksum and alignment bytes are added (20) to the digital data before tape storage and stripped (22) therefrom after successful alignment checks and data validation. In particular, the first column may be used to provide alignment bytes of a predetermined value for each row. The last column provides row checksum bytes for the data in each row. The last row provides column check sum bytes for each column, excluding the column of alignment bytes. The data location at the intersection of the row of column checksum bytes and the column of row checksum bytes may be used as a checksum byte for either the row or column checksum bytes.

Dotson, Ronald S. (Inventor)

1992-01-01

478

Analytical techniques for instrument design -- Matrix methods  

SciTech Connect

The authors take the traditional Cooper-Nathans approach, as has been applied for many years for steady-state triple-axis spectrometers, and consider its generalization to other inelastic scattering spectrometers. This involves a number of simple manipulations of exponentials of quadratic forms. In particular, they discuss a toolbox of matrix manipulations that can be performed on the 6-dimensional Cooper-Nathans matrix. They show how these tools can be combined to solve a number of important problems, within the narrow-band limit and the gaussian approximation. They will argue that a generalized program that can handle multiple different spectrometers could (and should) be written in parallel to the Monte-Carlo packages that are becoming available. They also discuss the complementarity between detailed Monte-Carlo calculations and the approach presented here. In particular, Monte-Carlo methods traditionally simulate the real experiment as performed in practice, given a model scattering law, while the Cooper-Nathans method asks the inverse question: given that a neutron turns up in a particular spectrometer configuration (e.g. angle and time of flight), what is the probability distribution of possible scattering events at the sample? The Monte-Carlo approach could be applied in the same spirit to this question.

Robinson, R.A.

1997-12-31

479

Shrinkage covariance matrix approach for microarray data  

NASA Astrophysics Data System (ADS)

Microarray technology was developed for the purpose of monitoring the expression levels of thousands of genes. A microarray data set typically consists of tens of thousands of genes (variables) from just dozens of samples due to various constraints including the high cost of producing microarray chips. As a result, the widely used standard covariance estimator is not appropriate for this purpose. One such technique is the Hotelling's T2 statistic which is a multivariate test statistic for comparing means between two groups. It requires that the number of observations (n) exceeds the number of genes (p) in the set but in microarray studies it is common that n < p. This leads to a biased estimate of the covariance matrix. In this study, the Hotelling's T2 statistic with the shrinkage approach is proposed to estimate the covariance matrix for testing differential gene expression. The performance of this approach is then compared with other commonly used multivariate tests using a widely analysed diabetes data set as illustrations. The results across the methods are consistent, implying that this approach provides an alternative to existing techniques.

Karjanto, Suryaefiza; Aripin, Rasimah

2013-04-01

480

Extracellular Matrix Dynamics and Fetal Membrane Rupture  

PubMed Central

The extracellular matrix (ECM) plays an important role in determining cell and organ function: (1) it is an organizing substrate that provides tissue tensile strength; (2) it anchors cells and influences cell morphology and function via interaction with cell surface receptors; and (3) it is a reservoir for growth factors. Alterations in the content and the composition of the ECM determine its physical and biological properties, including strength and susceptibility to degradation. The ECM components themselves also harbor cryptic matrikines, which when exposed by conformational change or proteolysis have potent effects on cell function, including stimulating the production of cytokines and matrix metalloproteinases (MMPs). Collectively, these properties of the ECM reflect a dynamic tissue component that influences both tissue form and function. This review illustrates how defects in ECM synthesis and metabolism and the physiological process of ECM turnover contribute to changes in the fetal membranes that precede normal parturition and contribute to the pathological events leading to preterm premature rupture of membranes (PPROM). PMID:22267536

Strauss,, Jerome F.

2013-01-01

481

Antibodies and immunohistochemistry in extracellular matrix research.  

PubMed

Immunohistochemistry is a powerful investigative tool that can provide researchers with important supplemental information to the routine morphological assessment of musculo-skeletal connective tissues in health and disease and also during tissue repair and regeneration. A wide variety of antibodies (both monoclonal and polyclonal) are now available from commercial and non-commercial sources that recognise the major structural and soluble components of cellular and extracellular matrix compartments. These include antibodies towards the major collagen and proteoglycan species and their metabolites, glycosaminoglycans, glycoproteins, enzymes, enzyme generated neo-epitopes, growth factors, cytokines and related signalling molecules. In addition, cell surface markers, cytoskeletal components and many other cytoplasmic and nuclear proteins, too numerous to mention, can also be detected. When allied with high resolution imaging modalities (e.g. confocal laser scanning microscopy) immunohistochemistry thus has the potential to reveal a wealth of macromolecular information about the complex three-dimensional composition and organisation of cellular and extracellular matrix compartments in many different connective tissue types. These technologies can also be used to quantify signal intensities and thereby facilitate numerical computation of image data. PMID:18442701

Hayes, Anthony J; Hughes, Clare E; Caterson, Bruce

2008-05-01

482

Solid matrix partition by fracture networks.  

PubMed

The geometrical properties of the matrix blocks formed by a random fracture network are investigated numerically, for a wide range of fracture shapes and for fracture densities ranging from the dilute limit to well above the threshold where the material is entirely partitioned into finite blocks. The main block characteristics are the density and volume fraction, the mean volume and surface area, and their number of faces. In the dilute limit, general expressions for these characteristics are obtained, which provide a good approximation of the numerical data for any fracture shape. In the dense regime, most properties are governed by power laws, which involve two fitted exponents independent of the fracture shape. The shape factors identified in the dilute limit remain relevant for dense networks and can be used to formulate a general model for the block characteristics, valid up to the total matrix fracturation. The transition density when this occurs is determined. It can also be used to account for the fracture shape effects in a very simple and fairly accurate general model. Beyond the transition density, the block characteristics converge as expected toward those in the space tesselation by infinite planes. PMID:25215742

Rosenzweig, R; Mourzenko, V V; Thovert, J-F; Adler, P M

2014-08-01

483

Lattice QCD for Precision Nucleon Matrix Elements  

E-print Network

Precision measurements on nucleons provide constraints on the Standard Model and can also discern the signatures predicted for particles beyond the Standard Model. Knowing the Standard Model inputs to nucleon matrix elements will be necessary to constrain the couplings of dark matter candidates such as the neutralino, to relate the neutron electric dipole moment to the CP-violating theta parameter, or to search for new TeV-scale particles though non-$V-A$ interactions in neutron beta decay. However, these matrix elements derive from the properties of quantum chromodynamics (QCD) at low energies, where the coupling is strong and thus perturbative treatments fail. Using lattice gauge theory, we can nonperturbatively calculate the QCD path integral on a supercomputer. In this proceeding, I will review a few representative areas in which lattice QCD can contribute to understanding the structure inside nucleon and how they can contribute to the search for beyond-the-Standard Model physics, with discussions of the difficulties and prospects for future development.

Huey-Wen Lin

2011-12-12

484

Random matrix ensembles from nonextensive entropy  

NASA Astrophysics Data System (ADS)

The classical Gaussian ensembles of random matrices can be constructed by maximizing Boltzmann-Gibbs-Shannon’s entropy, SBGS =-?dH[P(H)]ln[P(H)], with suitable constraints. Here, we construct and analyze random-matrix ensembles arising from the generalized entropy Sq = { 1-?dH [P(H)]q } /(q-1) (thus, S1 = SBGS ). The resulting ensembles are characterized by a parameter q measuring the degree of nonextensivity of the entropic form. Making q?1 recovers the Gaussian ensembles. If q?1 , the joint probability distributions P(H) cannot be factorized, i.e., the matrix elements of H are correlated. In the limit of large matrices two different regimes are observed. When q<1 , P(H) has compact support, and the fluctuations tend asymptotically to those of the Gaussian ensembles. Anomalies appear for q>1 : Both P(H) and the marginal distributions P( Hij ) show power-law tails. Numerical analyses reveal that the nearest-neighbor spacing distribution is also long-tailed (not Wigner-Dyson) and, after proper scaling, very close to the result for the 2×2 case — a generalization of Wigner’s surmise. We discuss connections of these “nonextensive” ensembles with other non-Gaussian ones, such as the so-called Lévy ensembles and those arising from soft confinement.

Toscano, Fabricio; Vallejos, Raúl O.; Tsallis, Constantino

2004-06-01

485

Measuring Sparticles with the Matrix Element  

SciTech Connect

We apply the Matrix Element Method (MEM) to mass determination of squark pair production with direct decay to quarks and LSP at the LHC, showing that simultaneous mass determination of squarks and LSP is possible. We furthermore propose methods for inclusion of QCD radiation effects in the MEM. The goal of the LHC at CERN, scheduled to start this year, is to discover new physics through deviations from the Standard Model (SM) predictions. After discovery of deviations from the SM, the next step will be classification of the new physics. An important first goal in this process will be establishing a mass spectrum of the new particles. One of the most challenging scenarios is pair-production of new particles which decay to invisible massive particles, giving missing energy signals. Many methods have been proposed for mass determination in such scenarios (for a recent list of references, see e.g. [1]). In this proceeding, we report the first steps in applying the Matrix Element Method (MEM) in the context of supersymmetric scenarios giving missing energy signals. After a quick review of the MEM, we will focus on squark pair production, a process where other mass determination techniques have difficulties to simultaneously determine the LSP and squark masses. Finally, we will introduce methods to extend the range of validity of the MEM, by taking into account initial state radiation (ISR) in the method.

Alwall, Johan; /SLAC /Taiwan, Natl. Taiwan U.; Freitas, Ayres; /Pittsburgh U.; Mattelaer, Olivier; /INFN, Rome3 /Rome III U. /Louvain U.

2012-04-10

486

Shock wave profiles in polymer matrix composite  

NASA Astrophysics Data System (ADS)

The promise of lightweight armor which is also structurally robust is of particular importance to the Army for future combat vehicles. Fiber reinforced organic matrix composites such as Polymer Matrix Composite (PMC) are being considered for this purpose due to their lower density and promising dynamic response. The work discussed here extends the prior work of Boteler who studied the delamination strength of PMC and Dandekar and Beaulieu who investigated the compressive and tensile strengths of PMC. In a series of shock wave experiments, the wave profile was examined as a function of propagation distance in PMC. Uniaxial strain was achieved by symmetric plate impact in the ARL 102 mm bore single-stage light gas gun. Embedded polyvinylidene flouride (PVDF) stress-rate gauges provided a stress history at three unique locations in the PMC and particle velocity history was recorded with VISAR. All stress data was compared to a Lagrangian hydrocode (EPIC) employing a model to describe the viscoelastic response of the composite material in one-dimension. The experimental stress histories displayed attenuation and loading properties in good agreement with model predictions. However, the unloading was observed to be markedly different than the hydrocode simulations. These results are discussed.

Boteler, J. Michael; Rajendran, A. M.; Grove, David

2000-04-01

487