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1

Elicitation using multiple price list formats  

Microsoft Academic Search

We examine the properties of a popular method for eliciting choices and values from experimental subjects, the multiple price\\u000a list format. The main advantage of this format is that it is relatively transparent to subjects and provides simple incentives\\u000a for truthful revelation. The main disadvantages are that it only elicits interval responses, and could be susceptible to framing\\u000a effects. We

Steffen Andersen; Glenn W. Harrison; Morten Igel Lau; E. Elisabet Rutström

2006-01-01

2

Graphic and tabular expressions of Bayes' theorem.  

PubMed

Bayes' theorem, as applied to the interpretation of diagnostic tests, is reexpressed as a two-step transformation. This allows for the construction of graphic and tabular expressions of this important principle. PMID:3574019

Benish, W A

1987-01-01

3

A heuristic block coordinate descent approach for controlled tabular adjustment  

Microsoft Academic Search

One of the main concerns of national statistical agencies (NSAs) is to publish tabular data. NSAs have to guarantee that no private information from specific respondents can be disclosed from the released tables. The purpose of the statistical disclosure control field is to avoid such a leak of private information. Most protection techniques for tabular data rely on the formulation

José A. González; Jordi Castro

2011-01-01

4

Users' guide for the tabular display report generator program (TABDIS)  

NASA Technical Reports Server (NTRS)

The tabular display report generator (TABDIS) program is described. The program functions as a document generation tool that provides tabular displays of data stored on a data file which has been generated by a user program. The main features of the program are outlined and all necessary inputs are detailed.

Braley, D. M.

1980-01-01

5

Optimal Design of Event Lists (ODELs) Phase 1: Does List Format Facilitate Visual Search for Information.  

National Technical Information Service (NTIS)

This report documents the first in a series of studies on the optimal design of event lists (ODELs) for Technical Operations use. The ODELs study described in this report examines whether event list format has an impact on user performance when searching ...

B. Kudrick V. Ahlstrom

2006-01-01

6

Abstraction Based Automated Test Generation from Formal Tabular Requirements Specifications  

Microsoft Academic Search

\\u000a We propose an automated approach for generating tests from formal tabular requirements specifications, such as SCR specifications.\\u000a The technique is based on counterexample guided abstraction refinement and the use of SMT solving. Moreover, in order to effectively\\u000a perform automated test generation, we take advantage of particular characteristics of tabular requirements descriptions to\\u000a aid the abstraction and abstraction refinement processes. The

Renzo Degiovanni; Pablo Ponzio; Nazareno Aguirre; Marcelo Frias

7

Tabular Interface for Automated Verification of Event-Based Dialogs.  

National Technical Information Service (NTIS)

In this report, we investigate the feasibility of a tabular interface for the specification and analysis of event-based dialogues. These dialogues are used to define high-level descriptions of interactive systems, and they are based on Olsen's Proposition...

H. M. Wang G. Abowd

1994-01-01

8

Satellite Monitoring of Giant Tabular Icebergs (Abstract Only).  

National Technical Information Service (NTIS)

A summary of a study reporting the monitoring of several giant tabular icebergs that have recently broken off the southern ice shelves is presented. Geosat radar altimetry is used to produce a contour map of the ice shelf before and after the calving of t...

S. Laxon C. G. Rapley G. Davies

1992-01-01

9

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

10

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

11

From tabular to rhombohedral dolomite crystals in Zechstein 2 dolostones from Scharzfeld (SW Harz/Germany): A case study with combined CL and EBSD investigations  

NASA Astrophysics Data System (ADS)

Tabular dolomite crystals found within dolomite rhombs have been investigated by cathodoluminescence (CL) microscopy and spectroscopy combined with electron backscatter diffraction (EBSD) for the first time. The dolomites formed in the Upper Permian Stassfurt Carbonate Ca2 at the southern margin of the German/Polish Zechstein Basin. Cathodoluminescence petrography of the dolostone succession revealed that the dolomites developed in four phases. Electron backscatter diffraction analysis reveals tabular crystal growth during the two first generations, while the last two generations are characterized by rhombohedral crystal shapes. The tabular dolomite cement crystals and their microcrystalline equivalents in matrix and components have a stoichiometric composition with good to very good lattice ordering. Manganese and iron contents of the tabular crystals are low and their carbon and oxygen isotope composition confirms an early diagenetic dolomite formation under marine-evaporitic conditions from precursor carbonates of Upper Permian age. CL spectroscopy reveals that the tabular dolomite generation 1 has a very high percentage of Mn 2+ on the Ca lattice position which results in a visually yellowish-green CL emission. Although relatively increased Mn 2+ contents at the Ca lattice position appear to be rather common in evaporitic dolomites the combination of a tabular crystal shape and a preferred input of Mn 2+ at the Ca lattice position is a remarkable phenomenon. As tabular dolomite crystals so far are exclusively reported from evaporitic diagenetic settings they could be the result of a high Mg/Ca ratio which blocks c-axis orientated growth of dolomite crystal. The occurrence of well ordered dolomite of which the geochemical zoning can be studied in such detail is rare for the earliest, synsedimentary stages of dolomite formation in marine environments, because these early stages commonly consist of not or badly ordered Ca-dolomites. A primary geochemical zoning of such dolomite usually gets lost during stabilisation and transformation to better ordering and stoichiometry.

Gillhaus, Axel; Richter, Detlev K.; Götte, Thomas; Neuser, Rolf D.

2010-07-01

12

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

13

Geosites inventory of the northwestern Tabular Middle Atlas of Morocco  

NASA Astrophysics Data System (ADS)

Across the northwestern Tabular Middle Atlas of Morocco there are many examples of landscapes, rocks and fossils that provide key evidence of a particular moment or period in Earth history. Such Earth heritage sites are important for educating the general public in environmental matters. They also serve as tools for demonstrating sustainable development and for illustrating methods of site conservation as well as remembering that rocks, minerals, fossils, soils, landforms form an integral part of the natural world. The significance of certain sites for aesthetic or tourism reasons is obvious. There are numerous geosites, which could contribute to effective exploitation of geotourism, often in conjunction with ecotourism. The strategy employed to such sites involves close consultation with all communities in the vicinity of the respective geosite and is not only aimed at tourism and education, but also at sustainable improvement of the infrastructure of the people of this area. Geological heritage sites, properly managed, can generate employment and new economic activities, especially in regions in need of new or additional sources of income.

El Wartiti, Mohamed; Malaki, Amina; Zahraoui, Mohamed; El Ghannouchi, Abdelilah; di Gregorio, Felice

2008-07-01

14

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

15

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

16

A Study of Graphical and Tabular Displays and Their Interaction with Environmental Complexity  

Microsoft Academic Search

Since most interactive systems use either graphical or tabular displays, this experiment contrasts the effectiveness of the two displays in making the production scheduling decision in low and intermediate levels of environmental complexity. The study concludes that tabular aids outperform the graphical aids in environments with low complexity, replicating an earlier study. In intermediate complexity environments, the graphical aids outperform

William Remus

1987-01-01

17

Fast Registration of Tabular Document Images Using the Fourier-Mellin Transform  

Microsoft Academic Search

A new technique is presented for quickly identifying global affine transformations applied to tabular document images, and to correct for those transformations. This technique, based on the Fourier-Mellin transform, is used to register (align) a set of tabular documents to each other. Each component of the affine transform is handled separately, which dramatically reduces the total parameter space of the

Luke A. D. Hutchison; William A. Barrett

2004-01-01

18

Preliminary investigation of the elemental variation and diagenesis of a tabular uranium deposit, La Sal Mine, San Juan County, Utah  

USGS Publications Warehouse

Ore in the La Sal mine, San Juan County, Utah, occurs as a typical tabular-type uranium deposit of the-Colorado Plateau. Uranium-vanadium occurs in the Salt Wash Member of the Jurassic Morrison Formation. Chemical and petrographic analyses were used to determine elemental variation and diagenetic aspects across the orebody. Vanadium is concentrated in the dark clay matrix, which constitutes visible ore. Uranium content is greater above the vanadium zone. Calcium, carbonate carbon, and lead show greater than fifty-fold increase across the ore zone, whereas copper and organic carbon show only a several-fold increase. Large molybdenum concentrations are present in and above the tabular layer, and large selenium concentrations occur below the uranium zone within the richest vanadium zone. Iron is enriched in the vanadium horizon. Chromium is depleted from above the ore and strongly enriched below. Elements that vary directly with the vanadium content include magnesium, iron, selenium, zirconium, strontium, titanium, lead, boron, yttrium, and scandium. The diagenetic sequence is as follows: (1) formation of secondary quartz overgrowths as cement; (2) infilling and lining of remaining pores with amber opaline material; (3) formation of vanadium-rich clay matrix, which has replaced overgrowths as well as quartz grains; (4) replacement of overgrowths and detrital grains by calcite; (5) infilling of pores with barite and the introduction of pyrite and marcasite.

Brooks, Robert A.; Campbell, John A.

1976-01-01

19

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

20

PERFORMANCE DIFFERENCES IN THE USE OF GRAPHIC AND TABULAR DISPLAYS OF MULTIVARIATE DATA  

Microsoft Academic Search

It has been suggested that gmphically displayed multivariate data help decision makers better understand information thy are called on to analyze This study compam judgments made from one recently suggested multivariate display technique with judgments made from traditional tabular displays of financial figures Significant differcnces in task performance are found to be related both to differences in the stimulus sets

David B. MacKay; Angelina Villarreal

1987-01-01

21

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

Microsoft Academic Search

Tabular sandstone uranium deposits constitute the largest uranium resource type in the United States. A major point of contention has been the nature and direction of the groundwater flow. This paper presents a quantitative simulation of regional ground-water flow during uranium deposition in the Westwater Canyon Member and Jackpile Sandstone Member of the Upper Jurassic Morrison Formation in the San

Sanford

2009-01-01

22

Fourier-Mellin registration of line-delineated tabular document images  

Microsoft Academic Search

Image registration (or alignment) is a useful preprocessing tool for assisting in manual data extraction from handwritten forms, as well as for preparing documents for batch OCR of specific page regions. A new technique is presented for fast registration of lined tabular document images in the presence of a global affine transformation, using the Discrete Fourier--Mellin Transform (DFMT). Each component

Luke A. D. Hutchison; William A. Barrett

2006-01-01

23

Noise-Tolerant Hyperspectral Signature Classification in Unresolved Object Detection with Adaptive Tabular Nearest Neighbor Encoding  

NASA Astrophysics Data System (ADS)

Accurate spectral signature classification is a crucial step in the nonimaging detection and recognition of spaceborne objects. In classical hyperspectral recognition applications, especially where linear mixing models are employed, signature classification accuracy depends on accurate spectral endmember discrimination. In selected target recognition (ATR) applications, previous non-adaptive techniques for signature classification have yielded class separation and classifier refinement results that tend to be suboptimal. In practice, the number of signatures accurately classified often depends linearly on the number of inputs. This can lead to potentially severe classification errors in the presence of noise or densely interleaved signatures. In this paper, we present an enhancement of an emerging technology for nonimaging spectral signature classification based on a highly accurate, efficient search engine called Tabular Nearest Neighbor Encoding (TNE). Adaptive TNE can optimize its classifier performance to track input nonergodicities and 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., a 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 through programmable algorithms. The open architecture and programmability of TNE's pattern-space (AM) processing allows a TNE developer to determine the qualitative and quantitative reasons for classification accuracy, as well as characterize in detail the signatures for which TNE does not obtain classification matches, and why such mis-matches occur. In this study AM-based classification has been modified to partially compensate for input statistical changes, in response to performance metrics such as probability of correct classification (Pd) and rate of false detections (Rfa). Adaptive TNE can thus achieve accurate signature classification in the presence of time-varying noise, closely spaced or interleaved signatures, and imaging system optical distortions. We analyze classification accuracy of closely spaced spectral signatures adapted from a NASA database of space material signatures. Additional analysis pertains to computational complexity and noise sensitivity, which are superior to non-adaptive TNE or Bayesian techniques based on classical neural networks.

Schmalz, M.; Key, G.

24

Automated recognition and extraction of tabular fields for the indexing of census records  

NASA Astrophysics Data System (ADS)

We describe a system for indexing of census records in tabular documents with the goal of recognizing the content of each cell, including both headers and handwritten entries. Each document is automatically rectified, registered and scaled to a known template following which lines and fields are detected and delimited as cells in a tabular form. Whole-word or whole-phrase recognition of noisy machine-printed text is performed using a glyph library, providing greatly increased efficiency and accuracy (approaching 100%), while avoiding the problems inherent with traditional OCR approaches. Constrained handwriting recognition results for a single author reach as high as 98% and 94.5% for the Gender field and Birthplace respectively. Multi-author accuracy (currently 82%) can be improved through an increased training set. Active integration of user feedback in the system will accelerate the indexing of records while providing a tightly coupled learning mechanism for system improvement.

Clawson, Robert; Bauer, Kevin; Chidester, Glen; Pohontsch, Milan; Kennard, Douglas; Ryu, Jongha; Barrett, William

2013-01-01

25

Evaluation of Cathode-Ray Tube protection for the electronic tabular display subsystem (ETABS) engineering model  

NASA Astrophysics Data System (ADS)

This report describes the safety evaluation of the 25-inch (diagonal) rectangular cathode-ray tube (CRT) that is used in the engineering model of the Electronic Tabular Display Subsystem (ETABS). An evaluation of ETABS will be performed at the Federal Aviation Administration (FAA) Technical Center for possible application in FAA Air Route Traffic Control Centers (ARTCC). The safety evaluation included standard industry pressure testing and special implosion testing on 12 CRT samples. Eleven of the twelve CRT samples satisfactorily met the safety requirements for both the pressure and implosion testing. One CRT cracked when subjected to 45 pounds per square inch (psi) of air pressure; however, the CRT did not implode. The 25-inch rectangular CRT will therefore provide a high degree of safety for use in each of the two tabular displays of the ETABS engineering model.

Wilson, A. R.

1981-09-01

26

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

27

Deriving Tabular Event-Based Specifications from Goal-Oriented Requirements Models  

Microsoft Academic Search

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

Renaud De Landtsheer; Emmanuel Letier; Axel Van Lamsweerde

2003-01-01

28

Comparison of Neural Networks and Tabular Nearest Neighbor Encoding for Hyperspectral Signature Classification in Unresolved Object Detection  

NASA Astrophysics Data System (ADS)

Accurate and computationally efficient spectral signature classification is a crucial step in the nonimaging detection and recognition of spaceborne objects. In classical hyperspectral recognition applications using linear mixing models, signature classification accuracy depends on accurate spectral endmember discrimination [1]. If the endmembers cannot be classified correctly, then the signatures cannot be classified correctly, and object recognition from hyperspectral data will be inaccurate. In practice, the number of endmembers accurately classified often depends linearly on the number of inputs. This can lead to potentially severe classification errors in the presence of noise or densely interleaved signatures. In this paper, we present an comparison of emerging technologies for nonimaging spectral signature classfication based on a highly accurate, efficient search engine called Tabular Nearest Neighbor Encoding (TNE) [3,4] and a neural network technology called Morphological Neural Networks (MNNs) [5]. 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. The open architecture and programmability of TNE's agreement map processing allows a TNE programmer or user to determine classification accuracy, as well as characterize in detail the signatures for which TNE did not obtain classification matches, and why such mis-matches occurred. In this study, we will compare TNE and MNN based endmember classification, using performance metrics such as probability of correct classification (Pd) and rate of false detections (Rfa). As proof of principle, we analyze classification of multiple closely spaced signatures 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. [1] Winter, M.E. "Fast autonomous spectral end-member determination in hyperspectral data," in Proceedings of the 13th International Conference On Applied Geologic Remote Sensing, Vancouver, B.C., Canada, pp. 337-44 (1999). [2] N. Keshava, "A survey of spectral unmixing algorithms," Lincoln Laboratory Journal 14:55-78 (2003). [3] Key, G., M.S. SCHMALZ, F.M. Caimi, and G.X. Ritter. "Performance analysis of tabular nearest neighbor encoding algorithm for joint compression and ATR", in Proceedings SPIE 3814:115-126 (1999). [4] Schmalz, M.S. and G. Key. "Algorithms for hyperspectral signature classification in unresolved object detection using tabular nearest neighbor encoding" in Proceedings of the 2007 AMOS Conference, Maui HI (2007). [5] Ritter, G.X., G. Urcid, and M.S. Schmalz. "Autonomous single-pass endmember approximation using lattice auto-associative memories", Neurocomputing (Elsevier), accepted (June 2008).

Schmalz, M.; Ritter, G.; Key, R.

29

Hydrogeology of an ancient arid closed basin: implications for tabular sandstone-hosted uranium deposits  

USGS Publications Warehouse

Hydrogeologic modeling shows that tabular-type uranium deposits in the Grants uranium region of the San Juan basin, New Mexico, formed in zones of ascending and discharging regional ground-water flow. The association of either lacustrine mudstone or actively subsiding structures and uranium deposits can best be explained by the occurrence of lakes at topographic depressions where ground water having different sources and compositions is likely to converge, mix, and discharge. Ascending and discharging flow also explains the association of uranium deposits with underlying evaporites and suggests a brine interface. The simulations contradict previous suggestions that ground water moved downward in the mudflat. -Author

Sanford, R. F.

1990-01-01

30

Formation of tabular single-domain magnetite induced by Geobacter metallireducens GS-15.  

PubMed

Distinct morphological characteristics of magnetite formed intracellularly by magnetic bacteria (magnetosome) are invoked as compelling evidence for biological activity on Earth and possibly on Mars. Crystals of magnetite produced extracellularly by a variety of bacteria including Geobacter metallireducens GS-15, thermophilic bacteria, and psychrotolerant bacteria are, however, traditionally not thought to have nearly as distinct morphologies. The size and shape of extracellular magnetite depend on the culture conditions and type of bacteria. Under typical CO(2)-rich culture conditions, GS-15 is known to produce superparamagnetic magnetite (crystal diameters of approximately <30 nm). In the current study, we were able to produce a unique form of tabular, single-domain magnetite under nontraditional (low-CO(2)) culture conditions. This magnetite has a distinct crystal habit and magnetic properties. This magnetite could be used as a biosignature to recognize ancient biological activities in terrestrial and extraterrestrial environments and also may be a major carrier of the magnetization in natural sediments. PMID:15525704

Vali, Hojatollah; Weiss, Benjamin; Li, Yi-Liang; Sears, S Kelly; Kim, Soon Sam; Kirschvink, Joseph L; Zhang, Chuanlun L

2004-11-16

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 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 online1 and there are two versions of it: one for Excel 2003 and one for Excel 2007/2010.

Haugland, Ole Anton

2011-12-01

34

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

35

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

36

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

NASA Astrophysics Data System (ADS)

Knowledge of iceberg locations is important for safety reasons as well as for understanding many geophysical and biological processes. Originally designed to measure wind speed and direction over the ocean, SeaWinds is a microwave scatterometer that operates at 13.4 GHz (Ku-band) on the QuikSCAT satellite. Radar measurements from SeaWinds are collected and processed on a daily basis using resolution-enhancement techniques to produce daily radar images. Because icebergs scatter microwave energy more than sea ice and sea water, icebergs are detected as high-backscatter targets surrounded by lower-backscatter regions in daily SeaWinds images. As a result, iceberg positions are determined in real-time and a time-series of iceberg positions is maintained in an Antarctic iceberg database by Brigham Young University's Microwave Earth Remote Sensing (MERS) laboratory. Since SeaWinds operates independent of both solar illumination and cloud cover and has a large daily spatial coverage, this paper demonstrates that SeaWinds is an excellent platform to detect and track large tabular icebergs. These icebergs are generally larger than 5 km and are typically characterized as a rough ice plateau above the surrounding sea water or sea ice. The number of icebergs tracked in the MERS Antarctic iceberg database is found to be generally greater than the number of icebergs tracked by the National Ice Center. The movement patterns of all icebergs detected by SeaWinds are also analyzed and 90% of icebergs are found to travel a counter-clockwise path around Antarctica and accumulate in the Weddell and Scotia Seas. Iceberg detection and tracking is demonstrated via multiple case studies that highlight icebergs C-19a and A-22a using the MERS database and through real-time operational support of the 2005, 2008, and 2009 NSF Antarctic cruises. Iceberg positions are validated by using collocated high-resolution satellite imagery and by navigating the NSF ships to physically intercept several large tabular icebergs in the Weddell and Scotia Seas.

Stuart, K. M.; Long, D. G.

2011-06-01

37

Calcium-doped ceria/titanate tabular functional nanocomposite by layer-by-layer coating method  

SciTech Connect

Ca-doped ceria (CDC)/tabular titanate (K{sub 0.8}Li{sub 0.27}Ti{sub 1.73}O{sub 4}, TT) UV-shielding functional nanocomposite with fairly uniform CDC coating layers was prepared through a polyelectrolyte-associated layer-by-layer (LbL) coating method. TT with lepidocrocite-like layered structure was used as the substrate, poly (diallyldimethylammonium chloride) (PDDA) was used as a coupling agent, CDC nanoparticles were used as the main UV-shielding component. CDC/TT nanocomposites with various coating layers of CDC were obtained through a multistep coating process. The phases were studied by X-ray diffraction. The morphology and coating quality were studied by scanning electron microscopy and element mapping of energy dispersive X-ray analysis. The oxidation catalytic activity, UV-shielding ability and using comfort were characterized by Rancimat test, UV-vis spectra and dynamic friction test, respectively. CDC/TT nanocomposites with low oxidation catalytic activity, high UV-shielding ability and good using comfort were finally obtained. - Graphical abstract: Through the control of surface charge of particles calcium-doped ceria/titanate composites with low oxidation catalytic activity, higher UV-shielding ability and excellent comfort was obtained by a facile layer-by-layer coating method.

Liu, Xiang W., E-mail: lxwluck@gmail.co [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Suita (Japan); Devaraju, M.K.; Yin, Shu; Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Suita (Japan)

2010-07-15

38

Calcium-doped ceria/titanate tabular functional nanocomposite by layer-by-layer coating method  

NASA Astrophysics Data System (ADS)

Ca-doped ceria (CDC)/tabular titanate (K 0.8Li 0.27Ti 1.73O 4, TT) UV-shielding functional nanocomposite with fairly uniform CDC coating layers was prepared through a polyelectrolyte-associated layer-by-layer (LbL) coating method. TT with lepidocrocite-like layered structure was used as the substrate, poly (diallyldimethylammonium chloride) (PDDA) was used as a coupling agent, CDC nanoparticles were used as the main UV-shielding component. CDC/TT nanocomposites with various coating layers of CDC were obtained through a multistep coating process. The phases were studied by X-ray diffraction. The morphology and coating quality were studied by scanning electron microscopy and element mapping of energy dispersive X-ray analysis. The oxidation catalytic activity, UV-shielding ability and using comfort were characterized by Rancimat test, UV-vis spectra and dynamic friction test, respectively. CDC/TT nanocomposites with low oxidation catalytic activity, high UV-shielding ability and good using comfort were finally obtained.

W. Liu, Xiang; Devaraju, M. K.; Yin, Shu; Sato, Tsugio

2010-07-01

39

Genesis of the tabular-type vanadium-uranium deposits of the Henry Basin, Utah  

USGS Publications Warehouse

Tabular-type vanadium-uranium deposits occur in fluvial sandstones of the Salt Wash Member of the Morrison Formation of Late Jurassic age The mineralized intervals and the weakly mineralized lateral extensions are bounded both above and below by zones rich in dolomite cement. Carbon isotope values of dolomite cements indicate that at least two sources of carbon existed. One source appears to be the same as that which formed the bedded carbonates in the evaporites in the Tidwell Member of the Morrison Formation stratigraphically below the mineralized interval. The second carbon source is typical of terrestrially deposited carbonates generally associated with meteoric water-dominated environments. Oxygen isotope values of these dolomites show the same trend of isotopically light values above the mineralized interval and isotopically heavier values in and below that interval; they indicate that two isotopically distinct fluids were involved in the mineralizing process. Some aspects of the origin of gangue and ore phases are explainable on the basis of processes which occurred solely within the saline fluid, but key aspects of ore genesis involved the interaction of the saline and meteoric waters. It is postulated that the solution interface migrated vertically within the stratigraphic section. -from Authors

Northrop, H. R.; Goldhaber, M. B.

1990-01-01

40

Intra-colonial response to Acroporid ``white syndrome'' lesions in tabular Acropora spp. (Scleractinia)  

NASA Astrophysics Data System (ADS)

‘White syndrome’ is considered to be the most prevalent coral disease on the Great Barrier Reef, characterised by rapid rates of lesion progression and high levels of colony mortality. This study investigated the production and translocation of photoassimilates towards white syndrome lesions (WSLs) and artificially inflicted lesions in healthy and diseased colonies of tabular Acropora spp. to determine the intra-colonial response to white syndrome using 14C labelling. Translocation of 14C labelled photoassimilates was preferentially orientated away from active WSLs, with minimal 14C activity observed in the lesion borders, whilst artificial lesions (ALs) created directly opposite WSL borders showed significantly higher 14C activity, suggesting active translocation of photoassimilates for tissue regeneration. Transport of photoassimilates in healthy coral colonies was preferentially oriented towards ALs with a higher perimeter-area ratio, although translocation towards WSL boundaries was minimal even though the lesion perimeter was often the width of the colony (>200 cm). We suggest that the preferential orientation of photoassimilates away from WSLs may represent a deliberate strategy by the colony to induce a ‘shutdown reaction’ in order to preserve intra-colonial resources within areas of the colony that are more likely to survive and recover.

Roff, G.; Hoegh-Guldberg, O.; Fine, M.

2006-05-01

41

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

42

Tabular Water Properties Interface for Hydra-TH: CASL THM.CFD.P6.03 Milestone Report, Computational Shock and Multiphysics, Severe Accident Analysis.  

National Technical Information Service (NTIS)

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 inter...

J. H. Carpenter N. Belcourt

2013-01-01

43

Cumulative radiation effect. Part VI: simple nomographic and tabular methods for the solution of practical problems.  

PubMed

In five previous papers, the concept of the Cumulative Radiation Effect (CRE) has been presented as a scale of accumulative sub-tolerance radiation damage. The biological effect generated in normal connective tissue by fractionated or continuous radiation therapy given in any temporal arrangement is described by the CRE on a unified scale of assessment, so that a unique value of the CRE describes a specific level of radiation effect. The basic methods of evaluating CREs were shown in these papers to facilitate a full understanding of the fundamental aspects of the CRE-system, but these methods can be time-consuming and tediuous for complex situations. In this paper, simple nomographic and tabular methods for the solution of practical problems are presented. An essential feature of solving a CRE problem is firstly to present it in a concise and readily appreciated form, and, to do this, nomenclature is introduced to describe schedules and regimes as compactly as possible. Simple algebraic equations are derived to describe the CRE achieved by multi-schedule regimes. In these equations, the equivalence conditions existing at the junctions between schedules are not explicit and the equations are based on the CREs of the constituent schedules assessed individually without reference to their context in the regime as a whole. This independent evaluations of CREs for each schedule results in a considerable simplification in the calculation of complex problems. The calculations are further simplified by the use of suitable tables and nomograms, so that the mathematics involved is reduced to simple arithmetical operations which require at the most the use of a slide rule but can be done by hand. The order of procedure in the presentation and calculation of CRE problems can be summarised in an evaluation procedure sheet. The resulting simple methods for solving practical problems of any complexity on the CRE-system are demonstrated by a number of examples. PMID:856533

Kirk, J; Gray, W M; Watson, E R

1977-01-01

44

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

NASA Astrophysics Data System (ADS)

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 periglacial environments, is intra-sedimentary (migration/intrusion). The objective of this study is to establish geochemical benchmarks describing the ice formation from atmospheric moisture and compare them with geochemical data of tabular ground ice. Shokalsky glacier on Novaya Zemlya (NZ), on the east coast of the Barents Sea, was chosen as a possible moisture source for the formation of tabular ground ice at the key section 'Shpindler' on Yugorsky peninsula, on the south coast of the Kara Sea. Tabular ice in the Shpindler section was compared to the Shokalsky glacier ice in both isotope/geochemical and structural aspects. In general, the hydrochemical properties of glacier ice at NZ and ground ice from Shpindler are closely correlated, while stable-isotope, microelemental and microbiological properties are substantially different. It was concluded that glacier ice most likely participated in the formation of tabular ground ice, but only as a source of refrozen meltwater.

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

45

LIMAT: a computer program for least-squares inversion of magnetic anomalies over long tabular bodies  

NASA Astrophysics Data System (ADS)

A popular method for the inversion of magnetic anomalies in total vertical or horizontal field over thin sheet thick dike and vertical fault is presented. The magnetic anomaly over thin sheet may be expressed as a polynomial of the form FX2+ C1FX+ C2F+ C3X3+ C4X2+ C5X+ C6 The initial parameters of the source are obtained from the coefficients C1,C2,…, C6 by inverting a 6×6 matrix. The thick dike and the vertical fault are an ensemble of thin sheets. So the same initial solution obtained for the thin sheet model can be used for the thick dike and the vertical fault. Besides, in this method the computer calculates the initial solution by using all the discrete magnetic anomaly values and the corresponding distances as an input. The initial solution thus obtained is modified in an iterative process using non-linear least-squares regression by employing Marquardt's algorithm. The regional value that is subjective in manual interpretation is also adjusted in this method to obtain a close fit. A computer program in FORTRAN 77 is presented and used to interpret synthetic and practical data and the efficacy of the results are discussed.

Raju, D. Ch. Venkata

2003-02-01

46

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

47

supraHex: an R/Bioconductor package for tabular omics data analysis using a supra-hexagonal map.  

PubMed

Biologists are increasingly confronted with the challenge of quickly understanding genome-wide biological data, which usually involve a large number of genomic coordinates (e.g. genes) but a much smaller number of samples. To meet the need for data of this shape, we present an open-source package called 'supraHex' for training, analysing and visualising omics data. This package devises a supra-hexagonal map to self-organise the input data, offers scalable functionalities for post-analysing the map, and more importantly, allows for overlaying additional data for multilayer omics data comparisons. Via applying to DNA replication timing data of mouse embryogenesis, we demonstrate that supraHex is capable of simultaneously carrying out gene clustering and sample correlation, providing intuitive visualisation at each step of the analysis. By overlaying CpG and expression data onto the trained replication-timing map, we also show that supraHex is able to intuitively capture an inherent relationship between late replication, low CpG density promoters and low expression levels. As part of the Bioconductor project, supraHex makes accessible to a wide community in a simple way, what would otherwise be a complex framework for the ultrafast understanding of any tabular omics data, both scientifically and artistically. This package can run on Windows, Mac and Linux, and is freely available together with many tutorials on featuring real examples at http://supfam.org/supraHex. PMID:24309102

Fang, Hai; Gough, Julian

2014-01-01

48

Tabular comparisons of the Flynn Creek impact crater, United States, Steinheim impact crater, Germany and Snowball explosion crater, Canada  

NASA Technical Reports Server (NTRS)

A tabular outline of comparative data is presented for 340 basic dimensional, morphological, and structural parameters and related aspects for three craters of the flat-floored, central uplift type, two of which are natural terrestrial impact craters and one is a large-scale experimental explosion crater. The three craters are part of a general class, in terms of their morphology and structural deformation that is represented on each of the terrestrial planets including the moon. One of the considered craters, the Flynn Creek Crater, was formed by a hypervelocity impact event approximately 360 m.y. ago in what is now north central Tennessee. The impacting body appears to have been a carbonaceous chondrite or a cometary mass. The second crater, the Steinheim Crater, was formed by an impact event approximately 14.7 m.y. ago in what is now southwestern Germany. The Snowball Crater was formed by the detonation of a 500-ton TNT hemisphere on flat-lying, unconsolidated alluvium in Alberta, Canada.

Roddy, D. J.

1977-01-01

49

Optical Matrix.Matrix Multiplier  

NASA Technical Reports Server (NTRS)

Proposed apparatus for optical multiplication of two matrices based on Stanford optical vector.matrix multiplier. Does not require redundant representation of one of matrices. Because apparatus performs multiplication in fully parallel manner, incorporated as subsystem into large optical-processing system. Optical matrix.matrix multiplier processes inputs in fully parallel fashion, without redundant matrix images or ancillary intermediate electronic processing.

Gheen, Gregory

1989-01-01

50

Matrix Algebra.  

National Technical Information Service (NTIS)

The purpose of this thesis is to develop a textbook which presents basic concepts of matrix algebra from a primarily computational perspective, for an introductory course in matrix algebra at the Naval Postgraduate School (NPS). The need for an introducto...

S. A. Rife

1996-01-01

51

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.

52

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

53

Graphical and tabular summaries of decay characteristics for once-through PWR, LMFBR, and FFTF fuel cycle materials. [Spent fuel, high-level waste fuel can scrap  

SciTech Connect

Based on the results of ORIGEN2 and a newly developed code called ORMANG, graphical and summary tabular characteristics of spent fuel, high-level waste, and fuel assembly structural material (cladding) waste are presented for a generic pressurized-water reactor (PWR), a liquid-metal fast breeder reactor (LMFBR), and the Fast Flux Test Facility (FFTF). The characteristics include radioactivity, thermal power, and toxicity (water dilution volume). Given are graphs and summary tables containing characteristic totals and the principal nuclide contributors as well as graphs comparing the three reactors for a single material and the three materials for a single reactor.

Croff, A.G.; Liberman, M.S.; Morrison, G.W.

1982-01-01

54

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

55

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

56

Matrix Arithmetic  

NSDL National Science Digital Library

Using Mathcad, Maple, Mathmatica, or MatLab, learner should be able to experiment with matrix addition, subtraction, and (mostly) multiplication; to see that many familiar arithmetic properties of real numbers carry over to matrices.

Smith, David

2002-01-08

57

Matrix Models and Matrix Integrals  

Microsoft Academic Search

We discuss the relations between arbitrary solutions of the loop equations describing the Hermitean one-matrix model and particular\\u000a (multicut) solutions corresponding to concrete matrix integrals. These latter have a series of specific properties and, in\\u000a particular, are described in terms of the Seiberg-Witten-Whitham theory. We consider the simplest example of an ordinary integral\\u000a in detail.

A. D. Mironov

2006-01-01

58

A Fortran 77 computer code for damped least-squares inversion of Slingram electromagnetic anomalies over thin tabular conductors  

NASA Astrophysics Data System (ADS)

A FORTRAN 77 computer code is presented that permits the inversion of Slingram electromagnetic anomalies to an optimal conductor model. Damped least-squares inversion algorithm is used to estimate the anomalous body parameters, e.g. depth, dip and surface projection point of the target. Iteration progress is controlled by maximum relative error value and iteration continued until a tolerance value was satisfied, while the modification of Marquardt's parameter is controlled by sum of the squared errors value. In order to form the Jacobian matrix, the partial derivatives of theoretical anomaly expression with respect to the parameters being optimised are calculated by numerical differentiation by using first-order forward finite differences. A theoretical and two field anomalies are inserted to test the accuracy and applicability of the present inversion program. Inversion of the field data indicated that depth and the surface projection point parameters of the conductor are estimated correctly, however, considerable discrepancies appeared on the estimated dip angles. It is therefore concluded that the most important factor resulting in the misfit between observed and calculated data is due to the fact that the theory used for computing Slingram anomalies is valid for only thin conductors and this assumption might have caused incorrect dip estimates in the case of wide conductors.

Dondurur, Derman; Sar?, Co?kun

2004-07-01

59

The far field effect of ice shelf calving: the oceanographic effect of the decay of large tabular icebergs at South Georgia  

NASA Astrophysics Data System (ADS)

South Georgia is a small island approximately 190 x 30 km within the Antarctic Circumpolar Current in the South Atlantic. It is surrounded by a continental shelf which extends typically more than 50 km from the coast and has an average depth ~200 m, although there are deeper submarine canyons. It is downstream of the Antarctic Peninsula and satellite observations have frequently shown that very large tabular icebergs which originate in the Bellingshausen and Weddell Seas, for example B10A, A22B and A38, reach the island. Once there they ground on the relatively wide and extensive shelf. Occasionally they can pass the island and continue their drift and decay in the open ocean of the Antarctic Circumpolar Current however, for many, such as A38 (~300 Gt), the region around the island is effectively the graveyard. When this happens potentially very large volumes of meteoric water are deposited onto the shelf of the island and there are consequent large effects on the regional hydrography. The island has been for many decades a long term study site for cross disciplinary work and from 2002-2006 two oceanographic moorings recorded physical parameters including temperature, salinity and water velocity in the region. This time period encompasses the period of A38’s demise. The effects of the melt water addition are clear in the regional situation and here we present melt rate calculations from both tidal forcing and background hydrography on the tabular icebergs, and consequent impacts of the significant freshwater addition at this isolated site.

Brandon, M. A.; Enderlein, P.; Murphy, E.

2010-12-01

60

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

61

Sentinel lymph node biopsy for breast cancer using methylene blue dye manifests a short learning curve among experienced surgeons: a prospective tabular cumulative sum (CUSUM) analysis  

PubMed Central

Background The benefits of sentinel lymph node biopsy (SLNB) for breast cancer patients with histologically negative axillary nodes, in whom axillary lymph node dissection (ALND) is thereby avoided, are now established. Low false negative rate, certainly with blue dye technique, mostly reflects the established high inherent accuracy of SLNB and low axillary nodal metastatic load (subject to patient selection). SLN identification rate is influenced by volume, injection site and choice of mapping agent, axillary nodal metastatic load, SLN location and skill at axillary dissection. Being more subject to technical failure, SLN identification seems to be a more reasonable variable for learning curve assessment than false negative rate. Methylene blue is as good an SLN mapping agent as Isosulfan blue and is much cheaper. Addition of radio-colloid mapping to blue dye does not achieve a sufficiently higher identification rate to justify the cost. Methylene blue is therefore the agent of choice for SLN mapping in developing countries. The American Society of Breast Surgeons recommends that, for competence, surgeons should perform 20 SLNB but admits that the learning curve with a standardized technique may be "much shorter". One appropriate remedy for this dilemma is to plot individual learning curves. Methods Using methylene blue dye, experienced breast surgeons performed SLNB in selected patients with breast cancer (primary tumor < 5 cm and clinically negative ipsilateral axilla). Intraoperative assessment and completion ALND were performed for standardization on the first 13 of 24 cases. SLN identification was plotted for each surgeon on a tabular cumulative sum (CUSUM) chart with sequential probability ratio test (SPRT) limits based on a target identification rate of 85%. Results The CUSUM plot crossed the SPRT limit line after 8 consecutive, positively identified SLN, signaling achievement of an acceptable level of competence. Conclusion Tabular CUSUM charting, based on a justified choice of parameters, indicates that the learning curve for SLNB using methylene blue dye is completed after 8 consecutive, positively identified SLN. CUSUM charting may be used to plot individual learning curves for trainee surgeons by applying a proxy parameter for failure in the presence of a mentor (such as failed SLN identification within 15 minutes).

East, Jeffrey M; Valentine, Christopher SP; Kanchev, Emil; Blake, Garfield O

2009-01-01

62

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.

63

BASIC Matrix Operations.  

ERIC Educational Resources Information Center

The curriculum materials and computer programs in this booklet introduce the idea of a matrix. They go on to discuss matrix operations of addition, subtraction, multiplication by a scalar, and matrix multiplication. The last section covers several contemporary applications of matrix multiplication, including problems of communication…

Digital Equipment Corp., Maynard, MA.

64

The Filbert Matrix  

Microsoft Academic Search

A Filbert matrix is a matrix whose (i,j) entry is 1\\/F_(i+j-1), where F_n is\\u000athe nth Fibonacci number. The inverse of the n by n Filbert matrix resembles\\u000athe inverse of the n by n Hilbert matrix, and we prove that it shares the\\u000aproperty of having integer entries. We prove that the matrix formed by\\u000areplacing the Fibonacci numbers

Thomas M. Richardson

1999-01-01

65

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

66

Highly Parallel Sparse Matrix-Matrix Multiplication  

Microsoft Academic Search

Generalized sparse matrix-matrix multiplication is a key primitive for many high performance graph algorithms as well as some linear solvers such as multigrid. We present the first parallel algorithms that achieve increasing speedups for an unbounded number of processors. Our algorithms are based on two-dimensional block distribution of sparse matrices where serial sections use a novel hypersparse kernel for scalability.

Aydin Bulucc; John R. Gilbert

2010-01-01

67

Carbonate fuel cell matrix  

DOEpatents

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

Farooque, Mohammad (Huntington, CT) [Huntington, CT; Yuh, Chao-Yi (New Milford, CT) [New Milford, CT

1996-01-01

68

Carbonate fuel cell matrix  

DOEpatents

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

Farooque, M.; Yuh, C.Y.

1996-12-03

69

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

70

Matrix with Prescribed Eigenvectors  

ERIC Educational Resources Information Center

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

Ahmad, Faiz

2011-01-01

71

Probability Matrix Decomposition Models.  

ERIC Educational Resources Information Center

Generalizing Boolean matrix decomposition to a larger class of matrix decomposition models is demonstrated, and probability matrix decomposition (PMD) models are introduced as a probabilistic version of the larger class. An algorithm is presented for the computation of maximum likelihood and maximum a posteriori estimates of the parameters of PMD…

Maris, Eric; And Others

1996-01-01

72

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

73

Highly Parallel Sparse Matrix-Matrix Multiplication  

Microsoft Academic Search

Generalized sparse matrix-matrix multiplication is a key primitive for many\\u000ahigh performance graph algorithms as well as some linear solvers such as\\u000amultigrid. We present the first parallel algorithms that achieve increasing\\u000aspeedups for an unbounded number of processors. Our algorithms are based on\\u000atwo-dimensional block distribution of sparse matrices where serial sections use\\u000aa novel hypersparse kernel for scalability.

Aydin Buluç; John R. Gilbert

2010-01-01

74

Efficient computation of the inverse of gametic relationship matrix for a marked QTL.  

PubMed

Best linear unbiased prediction of genetic merits for a marked quantitative trait locus (QTL) using mixed model methodology includes the inverse of conditional gametic relationship matrix (G-1) for a marked QTL. When accounting for inbreeding, the conditional gametic relationships between two parents of individuals for a marked QTL are necessary to build G-1 directly. Up to now, the tabular method and its adaptations have been used to compute these relationships. In the present paper, an indirect method was implemented at the gametic level to compute these few relationships. Simulation results showed that the indirect method can perform faster with significantly less storage requirements than adaptation of the tabular method. The efficiency of the indirect method was mainly due to the use of the sparseness of G-1. The indirect method can also be applied to construct an approximate G-1 for populations with incomplete marker data, providing approximate probabilities of descent for QTL alleles for individuals with incomplete marker data. PMID:16635448

Sargolzaei, Mehdi; Iwaisaki, Hiroaki; Colleau, Jean-Jacques

2006-01-01

75

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

76

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

77

Tabular data and graphical images in support of the U.S. Geological Survey National Oil and Gas Assessment--San Juan Basin Province (5022): Chapter 7 in Total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado  

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.

2013-01-01

78

Matrix metalloproteinases and atherosclerosis  

Microsoft Academic Search

Atherosclerosis is a major cause of coronary heart disease, and matrix metalloproteinases (MMPs) play an important role in\\u000a atherosclerosis by degrading the extracellular matrix, which results in cardiovascular remodeling. Recent studies have identified\\u000a enhanced expression of MMPs in the atherosclerotic lesion and their contribution to weakening of the vascular wall by degrading\\u000a the extracellular matrix. The transcription, enzyme processing, and

Noboru Watanabe; Uichi Ikeda

2004-01-01

79

The Matrix Market  

NSDL National Science Digital Library

The Matrix Market website, provided by the National Institute of Standards and Technology, is "a visual repository of test data for use in comparative studies of algorithms for numerical linear algebra." The repository includes about 500 sparse matrices from a variety of applications, along with matrix generation tools and services. Visitors can scan the top ten or browse the repository by collection, matrix name, or generator name. Search categories include: by matrix properties, by application area, by contributor, and in bibliography. Tools for browsing through the collection are also included. The Welcome page provides additional information on the project, as well as a few reports and technical presentations.

80

Transfer function matrix  

NASA Technical Reports Server (NTRS)

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

Seraji, H.

1987-01-01

81

The Weak Mixing Matrix  

NASA Astrophysics Data System (ADS)

We show that the Weak Mixing Matrix, ( *20c Uud & Uus & Uub Ucd & Ucs & Ucb Utd & Uts & Utb ) , is not equal to the product of rotations, and in particular, it is not equal to the KM, or the PDG Matrices. At most, we may find an approximating matrix for the Weak Mixing Matrix that is based on the rotation matrices. We show that one such approximating matrix for the Real part of the Weak Mixing Matrix is ( *20c ?C?C^3 & ?C?C^3 & ^3 ?C?C^2 - ?C?C^2 & ?C?C^2 & ^2 ?C - ?C^3 ?C & - ?C?C^3 ^2 ?C & ?C^2 ?C^3 ), where ?C is the Cabbibo angle. The approximating matrix depends on ?C alone, and predicts the Real part of the Weak Mixing Matrix to a high degree of accuracy. We establish, with a Chi-Squared Goodness-of- Fitness-Test, that our approximating matrix can be used with extremely high level of statistical confidence.

Dannon, Vic; Levine, Robert

2009-10-01

82

Matrix Lower Bound.  

National Technical Information Service (NTIS)

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 ...

J. F. Grear

2005-01-01

83

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

84

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

85

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

86

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.

87

Matrix Metalloproteinase Inhibitor Peptides.  

National Technical Information Service (NTIS)

The objects of the invention are: to provide means of purifying natural inhibitors of metalloproteinases; to provide matrix metalloproteinase inhibitors and derivatives thereof. The inhibitors may be obtained from natural sources, may be produced by synth...

W. G. Stetler-Stevenson L. A. Liotta H. C. Krutzsch

1990-01-01

88

Algorithms for Matrix Multiplication.  

National Technical Information Service (NTIS)

Strassen's and Winograd's algorithms for matrix multiplication are investigated and compared with the normal algorithm. Floating - point error bounds are obtained, and it is shown that scaling is essential for numerical accuracy using Winograd's method. I...

R. P. Brent

1970-01-01

89

The Missing Data Matrix.  

National Technical Information Service (NTIS)

The report deals with a multiple regression approach to the estimation of missing elements in a data matrix. Three types of missing data matrices are discussed and methods for their analysis are presented. Computational equations together with mathematica...

P. Horst

1967-01-01

90

Matrix theory of gravitation  

NASA Astrophysics Data System (ADS)

A new classical theory of gravitation within the framework of general relativity is presented. It is based on a matrix formulation of four-dimensional Riemann-spaces and uses no artificial fields or adjustable parameters. The geometrical stress-energy tensor is derived from a matrix-trace Lagrangian, which is not equivalent to the curvature scalar R. To enable a direct comparison with the Einstein-theory a tetrad formalism is utilized, which shows similarities to teleparallel gravitation theories, but uses complex tetrads. Matrix theory might solve a 27-year-old, fundamental problem of those theories (Sect. 4.1). For the standard test cases (PPN scheme, Schwarz schild-solution) no differences to the Einstein-theory are found. However, the matrix theory exhibits novel, interesting vacuum solutions.

Köhler, Wolfgang

2011-06-01

91

New Solvable Matrix Integrals  

Microsoft Academic Search

We generalize Harish-Chandra-Itzykson-Zuber and certain other integrals\\u000a(Gross-Witten integral and integrals over complex matrices) using the notion of\\u000atau function of matrix argument. In this case one can reduce the matrix\\u000aintegral to the integral over eigenvalues, which in turn is certain tau\\u000afunction. We also consider a generalization of the Kontsevich integral.

A. Yu. Orlov

2002-01-01

92

An MCS Matrix  

NSDL National Science Digital Library

The 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.

Spangler, Tim

1999-01-01

93

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

94

Mueller Matrix Imaging Polarimetry  

NASA Astrophysics Data System (ADS)

This dissertation describes the development of a Mueller Matrix Imaging Polarimeter (MMIP), a new instrument that measures polarization properties associated with multiple ray paths through optical systems and samples; it determines experimentally what polarization ray tracing algorithms calculate. The output is a Mueller matrix image, a data base from which all polarization characteristics of the sample may be determined. The MMIP is a rotating retarder Stokes polarimeter which includes a polarization state generator. In one configuration, it measures the Polarization Aberration Matrix of an optical system, a Mueller matrix as a function of pupil coordinate. From the Polarization Aberration Matrix, the diattenuation, retardance and depolarization along an array of ray paths are determined. It can measure the polarization uniformity across a sample aperture or a sample's dependence on angle of incidence. In another configuration, it measures a Point Spread Matrix, a Mueller matrix relating the polarization state (Stokes vector) of a point object to the distribution of intensity and polarization state across the image. The depolarization of a liquid crystal TV (LCTV) is calculated from its measured Mueller matrix and found to vary between 2% and 9% as a function of applied voltage, angle of incidence and incident polarization state. In addition, it is shown that if illuminated with its eigenpolarization state, the LCTV modulates phase-only for a large dynamic range of video voltages. The Point Spread Matrix of a 4-F optical system with a LCTV position in its pupil is measured, and spatial variations of polarization are observed across the Point Spread Function. The linear retardance of a PLZT modulator is found to spatially vary in certain regions across its aperture. The Polarization BRDF of near-angle scatter from a diamond turned mirror is measured, revealing as much as 40% depolarization in the scattered light. The Polarization Aberration Matrix of an injection molded plastic lens is measured, producing maps of the retardance and thus the strain birefringence. Finally, six figures of merits are measured for several polarizing beam splitter cubes, showing a systematic variation of linear polarization orientation across its field of view.

Pezzaniti, Joseph Larry

95

Matrix G-strands  

NASA Astrophysics Data System (ADS)

We discuss three examples in which one may extend integrable Euler–Poincaré ordinary differential equations to integrable Euler–Poincaré partial differential equations in the matrix G-Strand context. After describing matrix G-Strand examples for SO(3) and SO(4) we turn our attention to SE(3) where the matrix G-Strand equations recover the exact rod theory in the convective representation. We then find a zero curvature representation of these equations and establish the conditions under which they are completely integrable. Thus, the G-Strand equations turn out to be a rich source of integrable systems. The treatment is meant to be expository and most concepts are explained in examples in the language of vectors in {R}^3 .

Holm, Darryl D.; Ivanov, Rossen I.

2014-06-01

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

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

98

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

99

Matrix control of scarring  

PubMed Central

Repair of wounds usually results in restoration of organ function, even if suboptimal. However, in a minority of situations, the healing process leads to significant scarring that hampers homeostasis and leaves the tissue compromised. This scar is characterized by an excess of matrix deposition that remains poorly organized and weakened. While we know much of the early stages of the repair process, the transition to wound resolution that limits scar formation is poorly understood. This is particularly true of the inducers of scar formation. Here, we present a hypothesis that it is the matrix itself that is a primary driver of scar, rather than being simply the result of other cellular dysregulations.

Yates, Cecelia C.; Bodnar, Richard

2013-01-01

100

Complex matrix model duality  

SciTech Connect

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

Brown, T. W. [DESY, Hamburg, Theory Group, Notkestrasse, 85, D-22603 Hamburg (Germany)

2011-04-15

101

Biofilms: the matrix revisited.  

PubMed

Microbes often construct and live within surface-associated multicellular communities known as biofilms. The precise structure, chemistry and physiology of the biofilm all vary with the nature of its resident microbes and local environment. However, an important commonality among biofilms is that their structural integrity critically depends upon an extracellular matrix produced by their constituent cells. Extracellular matrices might be as diverse as biofilms, and they contribute significantly to the organization of the community. This review discusses recent advances in our understanding of the extracellular matrix and its role in biofilm biology. PMID:15639628

Branda, Steven S; Vik, Shild; Friedman, Lisa; Kolter, Roberto

2005-01-01

102

THE MATRIX RECONSIDERED  

Microsoft Academic Search

This article employs the conceptual opposition of the red and blue pill that is presented in The Matrix trilogy as a mechanism for investigating the philosophical antagonisms and structural conflicts commonly associated with the ‘information society’. The text is divided into two main parts: The first reconsiders the logical structure of this pharmacological dialectic, arguing that the choice between these

David J. Gunkel

2008-01-01

103

Matrix metalloproteinases and metastasis  

Microsoft Academic Search

Metastatic disease is responsible for the majority of cancer-related deaths, either directly due to tumor involvement of critical organs or indirectly due to complications of therapy to control tumor growth and spread. An understanding of the mechanisms of tumor cell invasion and metastasis may be important for devising therapies aimed at preventing tumor cell spread. Matrix metalloproteinases (MMPs) are a

David E. Kleiner; William G. Stetler-Stevenson

1999-01-01

104

Matrix Analogies Test (MAT).  

ERIC Educational Resources Information Center

The Matrix Analogies Test measures nonverbal ability of handicapped and nonhandicapped children, ages 5-17, in a culture-fair fashion. It assesses pattern completion, reasoning by analogy, serial reasoning, and spatial visualization, with a short form available as a screening instrument. This paper describes the test's administration, format,…

Nicholson, Charles L.

1990-01-01

105

The matrix sign function  

Microsoft Academic Search

A survey of the matrix sign function is presented including some historical background, definitions and properties, approximation theory and computational methods, and condition theory and estimation procedures, Applications to areas such as control theory, eigendecompositions, and roots of matrices are outlined, and some new theoretical results are also given

Charles S. Kenney; Alan J. Laub

1995-01-01

106

SIMNET Rotation Matrix.  

National Technical Information Service (NTIS)

This report presents a description of the nine element (3x3) rotation matrix used in the SIMNET Vehicle Appearance Protocol Data Unit (VA PDU) to describe a vehicle's orientation (Attitude) in free space. Also included is a program (written in Microsoft C...

J. Cadiz J. Thompson R. Quyang

1989-01-01

107

The Task Matrix Procedure.  

National Technical Information Service (NTIS)

A method for developing work samples geared to a range of entry-level jobs in an occupation or industry, rather than to a specific job, was developed in 1975. Differences between the task matrix procedure and conventional work sample development are discu...

T. A. Korn D. J. Dunn

1975-01-01

108

Hybridized Polymer Matrix Composites.  

National Technical Information Service (NTIS)

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 w...

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

1980-01-01

109

Hybrid Ceramic Matrix\\/Metal Matrix Composite Gun Barrels  

Microsoft Academic Search

Future Army gun systems will require lighter weight and significantly more erosion-resistant materials. One route to achieve this goal is via the development of ceramic matrix composite barrel liners with lightweight metal matrix composite jackets. Such materials systems are hybrids of a ceramic matrix composite\\/metal matrix composite (CMC\\/MMC), which can provide functionally graded properties. This paper will describe the materials

R. N. Katz; L. A. Bracamonte; J. C. Withers; S. Chaudhury

2006-01-01

110

ALGORITHMS FOR MATRIX MULTIPLICATION  

Microsoft Academic Search

Strassen's and Winograd's algorithms for n ? n matrix multiplication are investigated and compared with the normal algorithm. The normal algorithm requires n3 + O(n2) multiplications and about the same number of additions. Winograd's algorithm almost halves the number of multiplications at the expense of more additions. Strassen's algorithm reduces the total number of operations to O(n2.82) by recursively multiplying

R. P. BRENT

1970-01-01

111

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

112

Compact matrix pseudogroups  

Microsoft Academic Search

The compact matrix pseudogroup is a non-commutative compact space endowed with a group structure. The precise definition is given and a number of examples is presented. Among them we have compact group of matrices, duals of discrete groups and twisted (deformed)SU(N) groups. The representation theory is developed. It turns out that the tensor product of representations depends essentially on their

S. L. Woronowicz

1987-01-01

113

Matrix Pencil Equivalents of a General Polynomial Matrix.  

National Technical Information Service (NTIS)

An algorithm which permits the reduction of a general polynomial matrix to an equivalent matrix pencil form is described. The sense in which this is an equivalent is shown both from a matrix transformational point of view, and from the point of view of th...

G. E. Hayton A. B. Walker A. C. Pugh

1988-01-01

114

Hypercube matrix computation task  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

115

Matrix Theory of Small Oscillations  

ERIC Educational Resources Information Center

A complete matrix formulation of the theory of small oscillations is presented. Simple analytic solutions involving matrix functions are found which clearly exhibit the transients, the damping factors, the Breit-Wigner form for resonances, etc. (BB)

Chavda, L. K.

1978-01-01

116

Standard Errors for Matrix Correlations.  

ERIC Educational Resources Information Center

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

Ogasawara, Haruhiko

1999-01-01

117

Matrix multiplication via arithmetic progressions  

Microsoft Academic Search

We present a new method for accelerating matrix multiplication asymptotically. This work builds on recent ideas of Volker Strassen, by using a basic trilinear form which is not a matrix product. We make novel use of the Salem-Spencer Theorem, which gives a fairly dense set of integers with no three-term arithmetic progression. Our resulting matrix exponent is 2.376.

Don Coppersmith; Shmuel Winograd

1987-01-01

118

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

119

The cellulose resource matrix.  

PubMed

The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the feedstock and the performance in the end-application. The cellulose resource matrix should become a practical tool for stakeholders to make choices regarding raw materials, process or market. Although there is a vast amount of scientific and economic information available on cellulose and lignocellulosic resources, the accessibility for the interested layman or entrepreneur is very difficult and the relevance of the numerous details in the larger context is limited. Translation of science to practical accessible information with modern data management and data integration tools is a challenge. Therefore, a detailed matrix structure was composed in which the different elements or entries of the matrix were identified and a tentative rough set up was made. The inventory includes current commodities and new cellulose containing and raw materials as well as exotic sources and specialties. Important chemical and physical properties of the different raw materials were identified for the use in processes and products. When available, the market data such as price and availability were recorded. Established and innovative cellulose extraction and refining processes were reviewed. The demands on the raw material for suitable processing were collected. Processing parameters known to affect the cellulose properties were listed. Current and expected emerging markets were surveyed as well as their different demands on cellulose raw materials and processes. The setting up of the cellulose matrix as a practical tool requires two steps. Firstly, the reduction of the needed data by clustering of the characteristics of raw materials, processes and markets and secondly, the building of a database that can provide the answers to the questions from stakeholders with an indicative character. This paper describes the steps taken to achieve the defined clusters of most relevant and characteristic properties. These data can be expanded where required. More detailed specification can be obtained from the background literature and handbooks. Where gaps of information are ident

Keijsers, Edwin R P; Y?lmaz, Gülden; van Dam, Jan E G

2013-03-01

120

The gravitational S matrix  

SciTech Connect

We investigate the hypothesized existence of an S matrix for gravity and some of its expected general properties. We first discuss basic questions regarding the existence of such a matrix, including those of infrared divergences and description of asymptotic states. Distinct scattering behavior occurs in the Born, eikonal, and strong gravity regimes, and we describe aspects of both the partial wave and momentum space amplitudes, and their analytic properties, from these regimes. Classically the strong gravity region would be dominated by the formation of black holes, and we assume its unitary quantum dynamics is described by corresponding resonances. Masslessness limits some powerful methods and results that apply to massive theories, though a continuation path implying crossing symmetry plausibly still exists. Physical properties of gravity suggest nonpolynomial amplitudes, although crossing and causality constrain (with modest assumptions) this nonpolynomial behavior, particularly requiring a polynomial bound in complex s at fixed physical momentum transfer. We explore the hypothesis that such behavior corresponds to a nonlocality intrinsic to gravity, but consistent with unitarity, analyticity, crossing, and causality.

Giddings, Steven B.; Porto, Rafael A. [Department of Physics, University of California, Santa Barbara, California 93106 (United States) and PH-TH, CERN, 1211 Geneve 23 (Switzerland)

2010-01-15

121

Ceramic matrix and resin matrix composites: A comparison  

NASA Technical Reports Server (NTRS)

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

Hurwitz, Frances I.

1987-01-01

122

Extracellular Matrix 3: Evolution of the extracellular matrix in invertebrates  

Microsoft Academic Search

This is the third Serial Review on the role of the extracellu- larmatrix.The firsttwo reviews (FASEBJ. 7, 737-743; 996-1003, 1993) dealtwith the informationexchange be- tween cells and matrix, paying particular attention to the ways in which the matrix governs the attachment, differen- tiation and growth of cells. In the present review, we turn to the evolutionary aspects of the matrix.

MARVIN L. TANZER

1993-01-01

123

Validation of matrix diffusion modeling  

NASA Astrophysics Data System (ADS)

Crystalline rock has been chosen as the host medium for repository of highly radioactive spent nuclear fuel in Finland. Radionuclide transport takes place along water-carrying fractures, and matrix diffusion has been indicated as an important retarding mechanism that affects the transport of mobile fission and activation products. The model introduced here for matrix diffusion contains a flow channel facing a porous matrix with stagnant water into which tracer molecules advected in the channel can diffuse. In addition, the possibility of a finite depth of the matrix and an initial tracer distribution (‘contamination’) in the matrix are included in the model. In order to validate the developed matrix diffusion model, a relatively simple measuring system was constructed. Matrix diffusion was illustrated by observing the migration of 0.1 ml KCl pulses in the water flowing through a channel facing a porous matrix made of synthetic fibre felt. Migration of K + and Cl - ions was monitored by measuring the electrical conductivity of the solution. The experimental system allowed also measurements on the concentration profile inside the porous matrix, but the focus is here on the input and output (breakthrough) pulses. Measurements were performed for two different initial distributions of KCl tracer in the porous matrix. There was excellent agreement between modeling and experimental results with consistent values for the diffusion coefficient used as the fitting parameter.

Voutilainen, M.; Kekäläinen, P.; Hautojärvi, A.; Timonen, J.

124

A Review of Matrix Differentiation in Statistics.  

National Technical Information Service (NTIS)

The different matrix derivative methods available in terms of a common notation based on the Bargmann matrix calculus is presented. Matrix derivatives of specific scalar functions are considered as well as matrix derivatives of scalar functions in general...

D. G. Nel

1978-01-01

125

Light cone matrix product  

SciTech Connect

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

Hastings, Matthew B [Los Alamos National Laboratory

2009-01-01

126

Epigenetics within the matrix  

PubMed Central

Fibrosis of any tissue is characterized by excessive extracellular matrix accumulation that ultimately destroys tissue architecture and eventually abolishes normal organ function. Although much research has focused on the mechanisms underlying disease pathogenesis, there are still no effective antifibrotic therapies that can reverse, stop or delay the formation of scar tissue in most fibrotic organs. As fibrosis can be described as an aberrant wound healing response, a recent hypothesis suggests that the cells involved in this process gain an altered heritable phenotype that promotes excessive fibrotic tissue accumulation. This article will review the most recent observations in a newly emerging field that links epigenetic modifications to the pathogenesis of fibrosis. Specifically, the roles of DNA methylation and histone modifications in fibrotic disease will be discussed.

Robinson, Claire M.; Watson, Chris J.; Baugh, John A.

2012-01-01

127

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

128

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

129

Matrix Multiplication via Arithmetic Progressions  

Microsoft Academic Search

We present a new method for accelerating matrix multiplication asymptotically. This work builds on recent ideas of Volker Strassen,by using a basic trilinear form which is not a matrix product. We make novel use of the Salem-Spencer Theorem, which gives a fairly dense set of integers with no three-term arithmetic progression. Our resulting matrix exponent is 2.376.

Don Coppersmith; Shmuel Winograd

1990-01-01

130

Homolumo gap and matrix model  

SciTech Connect

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.

Andric, I.; Jonke, L.; Jurman, D.; Nielsen, H. B. [Theoretical Physics Division, Rudjer Boskovic Institute, P.O. Box 180, 10002 Zagreb (Croatia); Niels Bohr Institute, Copenhagen DK 2100 (Denmark)

2008-06-15

131

Matrix-matrix multiplications and fault tolerance on hypercube multiprocessors  

Microsoft Academic Search

Several new algorithms for matrix-matrix multiplications on hypercube multiprocessors are presented and evaluated based on the number of multiplications, additions, and transfers. The matrices to be multiplied are uniformly distributed to all processors of a hypercube system. Each processor owns some submatrices which are derived by dividing the source matrices. Each submatrix multiplication can now be performed independently within a

Yuh-Rong Leu; Ing-Yi Chen; Sy-Yen Kuo

1993-01-01

132

Optimizing Tpetra's Sparse Matrix-Matrix Multiplication Routine.  

National Technical Information Service (NTIS)

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, s...

K. L. Nusbaum

2011-01-01

133

Matrix metalloproteinase degradation of extracellular matrix: biological consequences  

Microsoft Academic Search

Targeted mutagenesis has allowed investigators to perform controlled experiments in mammals and determine the contribution of individual proteins to physiologic and pathologic processes. Recent lessons learned from matrix metalloproteinase gene targeted mice and other in vivo observations have given new life to old concepts regarding the role of proteolytic fragments of extracellular matrix proteins in regulating a variety of critical

Steven D Shapiro

1998-01-01

134

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

135

Hypercube matrix computation task  

NASA Technical Reports Server (NTRS)

The Hypercube Matrix Computation (Year 1986-1987) task investigated the applicability of a parallel computing architecture to the solution of large scale electromagnetic scattering problems. Two existing electromagnetic scattering codes were selected for conversion to the Mark III Hypercube concurrent computing environment. They were selected so that the underlying numerical algorithms utilized would be different thereby providing a more thorough evaluation of the appropriateness of the parallel environment for these types of problems. The first code was a frequency domain method of moments solution, NEC-2, developed at Lawrence Livermore National Laboratory. The second code was a time domain finite difference solution of Maxwell's equations to solve for the scattered fields. Once the codes were implemented on the hypercube and verified to obtain correct solutions by comparing the results with those from sequential runs, several measures were used to evaluate the performance of the two codes. First, a comparison was provided of the problem size possible on the hypercube with 128 megabytes of memory for a 32-node configuration with that available in a typical sequential user environment of 4 to 8 megabytes. Then, the performance of the codes was anlyzed for the computational speedup attained by the parallel architecture.

Calalo, R.; Imbriale, W.; Liewer, P.; Lyons, J.; Manshadi, F.; Patterson, J.

1987-01-01

136

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

137

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

138

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

139

Matrix theory on noncommutative torus  

Microsoft Academic Search

We consider the compactification of Matrix theory on tori with background antisymmetric tensor field. Douglas and Hull have recently discussed how noncommutative geometry appears on the tori. In this paper, we demonstrate the concrete construction of this compactification of Matrix theory in a similar way to that previously given by Taylor.

Teruhiko Kawano; Kazumi Okuyama

1998-01-01

140

Accelerating matrix decomposition with replications  

Microsoft Academic Search

Matrix decomposition applications that involve large matrix operations can take advantage of the flexibility and adaptability of reconfigurable computing systems to improve performance. The benefits come from replication, which includes vertical replication and horizontal replication. If viewed on a space-time chart, vertical replication allows multiple computations executed in parallel, and horizontal replication renders multiple functions on the same piece of

Yi-gang Tai; Chia-tien Dan Lo; Kleanthis Psarris

2008-01-01

141

Fast Parallel Matrix Inversion Algorithms  

Microsoft Academic Search

In this paper, an investigation of the parallel arithmetic complexity of matrix inversion, solving systems of linear equations, computing determinants and computing the characteristic polynomial of a matrix is reported. The parallel arithmetic complexity of solving equations has been an open question for several years. The gap between the complexity of the best algorithms (2n + 0(1), where n is

L. Csanky

1975-01-01

142

Fayalitic olivine in CV3 chondrite matrix and dark inclusions: A nebular origin  

NASA Astrophysics Data System (ADS)

Fayalitic olivine (Fa>32) is the major component of the matrices and Dark Inclusions (DI) of CV3 and other unequilibrated chondrites. It occurs most commonly as rims, veins and halos in and around chondrule silicates in the Allende-type (CV3OxA) chondrites and to a much lesser extent in the reduced (CV3R) and Bali-type (CV3OxB) chondrites. The olivines have distinctive platy, tabular and lath- or irregular-shaped crystals, with the ratio the two types varying widely. In CV3OxB chondrites, matrix fayalitic olivines range up to Fa99.9, whereas in the other CV3 chondrites the range is much smaller. The platy and tabular anisotropic forms of the fayalitic olivines strongly suggest growth from a vapor and the nature of occurrences suggests that CV3 matrices are unequilibrated mixtures of nebular materials. We argue that the parent body hydration/dehydration model has numerous inconsistencies that make this hypothesis highly unlikely. These include: (1) There is no direct evidence linking fayalitic olivine to precursor phyllosilicates. (2) Dehydration of phyllosilicates cannot explain the wide range of morphologies of the fayalitic olivines. (3) Fayalitic olivine clearly predates the formation of the hydrous phases in CV3 chondrites and is one of the phases that breaks down to form phyllosilicates (Keller et al., 1994). (4) The unequilibrated nature of the matrix, including fine scale zoning in 10=B5-sized fayalitic olivine crystals, would not survive the parent body metamorphism required in the dehydration model. (5) A DI in the Ningqiang chondrite contains fayalitic olivine rimmed by glassy and microcrystalline material (Zolensky et al., 1997), which probably formed by radiation damage. This indicates that the fayalitic olivine was exposed to solar radiation in a nebular setting. (6) Some Allende chondrules contain unaltered primary, anhydrous glassy mesostasis in contact with the host matrix (e.g., Ikeda and Kimura, 1995). Chondrule mesostases would not have survived parent body hydration without becoming hydrated and would probably not survive the metamorphic heating required in the dehydration scenario. (7) Single platy and barrel-shaped crystals of fayalitic olivine are present in accretionary rims in CAIs (MacPherson and Davis, 1997), which developed in the nebula. (8) Matrix lumps completely encased in chondrules in ordinary chondrites contain mainly fayalitic olivine (Scott et al., 1984), indicating a nebular origin. (9) Oxygen isotopic compositions of Allende matrix and DIs strongly indicate little or no hydration for Allende and its components (Clayton, 1997). We favor a nebular vaporization/recondensation model in which vaporization of chondritic dust produced a fayalite-rich vapor, followed by formation of the fayalitic olivine by direct recondensation from the vapor, epitactic growth on surfaces of existing forsterite and enstatite in chondrules, and replacement of existing forsterite and enstatite by gas-solid exchange.

Weisberg, Michael K.; Prinz, Martin

1998-09-01

143

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

144

Hierarchical Matrix-Matrix Multiplication Based on Multiprocessor Tasks  

Microsoft Academic Search

We consider the realization of matrix-matrix multiplication and propose a hierarchical algorithm implemented in a task-parallel way using multiprocessor tasks on distributed memory. The algorithm has been designed to minimize the communication overhead while showing large locality of memory references. The task-parallel realization makes the algorithm especially suited for cluster of SMPs since tasks can then be mapped to the

Sascha Hunold; Thomas Rauber; Gudula Rünger

2004-01-01

145

Challenges and Advances in Parallel Sparse Matrix-Matrix Multiplication  

Microsoft Academic Search

We identify the challenges that are special to parallel sparse matrix-matrix multiplication (PSpGEMM). We show that sparse algorithms are not as scalable as their dense counterparts, because in general, there are not enough non-trivialarithmeticoperationsto hidethecommunication costs aswell as thesparsity overheads. We analyzethescal- ability of 1D and 2D algorithms for PSpGEMM. While the 1D algorithm is a variant of existing implementations,

Aydin Buluc; John R. Gilbert

2008-01-01

146

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.

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

2013-01-01

147

High Temperature Polymer Matrix Composites  

NASA Technical Reports Server (NTRS)

These are the proceedings of the High Temperature Polymer Matrix Composites Conference held at the NASA Lewis Research Center on March 16 to 18, 1983. The purpose of the conference is to provide scientists and engineers working in the field of high temperature polymer matrix composites an opportunity to review, exchange, and assess the latest developments in this rapidly expanding area of materials technology. Technical papers are presented in the following areas: (1) matrix development; (2) adhesive development; (3) characterization; (4) environmental effects; and (5) applications.

1985-01-01

148

Welcome to PRI's "Matrix Project"!  

NSDL National Science Digital Library

The "Matrix Project" is an activity for students in which they receive bags of 11,000-year-old excavated materials including fossils, rocks, preserved organic material, etc.; students then identify the materials and learn more about them.

2001-04-03

149

Lung Multiple Primary Rules Matrix  

Cancer.gov

Lung Multiple Primary Rules – Matrix C340-C349 (Excludes lymphoma and leukemia M9590 – 9989 and Kaposi sarcoma M9140) * Prepare one abstract. Use the histology coding rules to assign the appropriate histology code. ** Prepare two or more abstracts.

150

Nucleic acid-based matrixes  

US Patent & Trademark Office Database

Various nucleic acid-based matrixes are provided, comprising nucleic acid monomers as building blocks, as well as nucleic acids encoding proteins, so as to produce novel biomaterials. Methods of utilizing such biomaterials include cell-free protein synthesis.

2013-07-16

151

Characterization of Metal Matrix Composites.  

National Technical Information Service (NTIS)

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 mo...

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

1994-01-01

152

Autocorrelation of Random Matrix Polynomials  

NASA Astrophysics Data System (ADS)

We calculate the autocorrelation functions (or shifted moments) of the characteristic polynomials of matrices drawn uniformly with respect to Haar measure from the groups U(N), O(2N) and USp(2N). In each case the result can be expressed in three equivalent forms: as a determinant sum (and hence in terms of symmetric polynomials), as a combinatorial sum, and as a multiple contour integral. These formulae are analogous to those previously obtained for the Gaussian ensembles of Random Matrix Theory, but in this case are identities for any size of matrix, rather than large-matrix asymptotic approximations. They also mirror exactly the autocorrelation formulae conjectured to hold for L-functions in a companion paper. This then provides further evidence in support of the connection between Random Matrix Theory and the theory of L-functions.

Conrey, J. B.; Farmer, D. W.; Keating, J. P.; Rubinstein, M. O.; Snaith, N. C.

153

Extracellular matrix and wound healing.  

PubMed

Extracellular matrix has been known for a long time as an architectural support for the tissues. Many recent data, however, have shown that extracellular matrix macromolecules (collagens, elastin, glycosaminoglycans, proteoglycans and connective tissue glycoproteins) are able to regulate many important cell functions, such as proliferation, migration, protein synthesis or degradation, apoptosis, etc., making them able to play an important role in the wound repair process. Not only the intact macromolecules but some of their specific domains, that we called "Matrikines", are also able to regulate many cell activities. In this article, we will summarize main findings showing the effects of extracellular matrix macromolecules and matrikines on connective tissue and epithelial cells, particularly in skin, and their potential implication in the wound healing process. These examples show that extracellular matrix macromolecules or some of their specific domains may play a major role in wound healing. Better knowledge of these interactions may suggest new therapeutic targets in wound healing defects. PMID:24650524

Maquart, F X; Monboisse, J C

2014-04-01

154

Nonlocal thermodynamic equilibrium response matrix  

Microsoft Academic Search

A connection between atomic kinetics and non-equilibrium thermodynamics has been recently established using a collisional-radiative model modified to include line absorption. The net emission can be expressed as a symmetric non-local thermodynamic-equilibrium response-matrix. This connection is extended to models used in hydrodynamic codes to simulate laser–plasma interactions. A new, exact and, general formula is obtained for the response-matrix and an

G. Faussurier; R. M. More

2003-01-01

155

Form development sample test matrix  

SciTech Connect

This document summarizes the status of sample fabrication and analysis in the Form Development Sample Test Matrix. Since its publication in the ''Baseline Formulation'' report (UCRL-ID- 133089, PIP-99-O 12) and in the ''Complete Single-Phase Sample Fabrications that Support the Licensing Application and Complete Process and Compositional Extreme Sample Fabrications that Support the Licensing Application'' report (PIP-99-078), the Sample Test Matrix has been updated and expanded. This version is current though September 30, 1999.

Ebbinghaus, B B

1999-10-15

156

Matrix isolation in photoelectron spectroscopy  

NASA Astrophysics Data System (ADS)

A range of volatile inorganic species have been trapped in a zinc matrix using the process of co-condensation and their UV photoelectron spectra have been recorded. These are seen to correspond to broadened versions of the molecular spectra with ionization energies subject to small polarization shifts. Differences in the ionization energies measured for low doses of condensate and those measured for higher doses are interpreted in terms of isolation of small and large clusters within the zinc matrix.

Potts, A. W.; Anjum, S.; Benson, J.; Novak, I.

1992-04-01

157

Universal Keplerian state transition matrix  

NASA Astrophysics Data System (ADS)

A completely general method for computing the Keplerian state transition matrix in terms of Goodyear's universal variables is presented. This includes a new scheme for solving Kepler's problem which is a necessary first step to computing the transition matrix. The Kepler problem is solved in terms of a new independent variable requiring the evaluation of only one transcendental function. Furthermore, this transcendental function may be conveniently evaluated by means of a Gaussian continued fraction.

Shepperd, S. W.

1985-02-01

158

Universal Keplerian state transition matrix  

NASA Technical Reports Server (NTRS)

A completely general method for computing the Keplerian state transition matrix in terms of Goodyear's universal variables is presented. This includes a new scheme for solving Kepler's problem which is a necessary first step to computing the transition matrix. The Kepler problem is solved in terms of a new independent variable requiring the evaluation of only one transcendental function. Furthermore, this transcendental function may be conveniently evaluated by means of a Gaussian continued fraction.

Shepperd, S. W.

1985-01-01

159

Staggered chiral random matrix theory  

SciTech Connect

We present a random matrix theory for the staggered lattice QCD Dirac operator. The staggered random matrix theory is equivalent to the zero-momentum limit of the staggered chiral Lagrangian and includes all taste breaking terms at their leading order. This is an extension of previous work which only included some of the taste breaking terms. We will also present some results for the taste breaking contributions to the partition function and the Dirac eigenvalues.

Osborn, James C. [Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2011-02-01

160

Matrix models for beta ensembles  

Microsoft Academic Search

This paper constructs tridiagonal random matrix models for general (beta>0) beta-Hermite (Gaussian) and beta-Laguerre (Wishart) ensembles. These generalize the well-known Gaussian and Wishart models for beta=1,2,4. Furthermore, in the cases of the beta-Laguerre ensembles, we eliminate the exponent quantization present in the previously known models. We further discuss applications for the new matrix models, and present some open problems.

Ioana Dumitriu; Alan Edelman

2002-01-01

161

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

162

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

163

Designing partial Mueller matrix polarimeters  

NASA Astrophysics Data System (ADS)

When using a MMP for a detection or identification task, a user considers certain elements of the Mueller matrix. The usual way of performing this task is to measure the full Mueller matrix and discard the unused elements. For polarimeter designs with speed, miniaturization, or other constraints it may be desirable to have a system with reduced dimensionality that measures only the important elements of the Mueller matrix as efficiently as possible. In this paper, we develop a framework that allows partial MMPs to be analyzed. Quantitative metrics are developed by considering geometrical relationships between the space spanned by a particular MMP and the space occupied by the scene components. The method is generalized to allow the effects of noise to come into the equation when noise performance is important as well.

Tyo, J. Scott; Johnson, Sergio J.; Wang, Zhipeng; Hoover, Brian G.

2009-08-01

164

Progress in matrix metalloproteinase research  

PubMed Central

Matrix metalloproteinases (MMPs) are now acknowledged as key players in the regulation of both cell–cell and cell–extracellular matrix interactions. They are involved in modifying matrix structure, growth factor availability and the function of cell surface signalling systems, with consequent effects on cellular differentiation, proliferation and apoptosis. They play central roles in morphogenesis, wound healing, tissue repair and remodelling in response to injury and in the progression of diseases such as arthritis, cancer and cardiovascular disease. Because of their wide spectrum of activities and expression sites, the elucidation of their potential as drug targets in disease or as important features of the repair process will be dependent upon careful analysis of their role in different cellular locations and at different disease stages. Novel approaches to the specific regulation of individual MMPs in different contexts are also being developed.

Murphy, Gillian; Nagase, Hideaki

2010-01-01

165

More on the Kronecker Structured Covariance Matrix  

Microsoft Academic Search

In this article, the multivariate normal distribution with a Kronecker product structured covariance matrix is studied. Particularly focused is the estimation of a Kronecker structured covariance matrix of order three, the so called double separable covariance matrix. The suggested estimation generalizes the procedure proposed by Srivastava et al. (2008) for a separable covariance matrix. The restrictions imposed by separability and

Martin Singull; M. Rauf Ahmad; Dietrich von Rosen

2012-01-01

166

Scalability Analysis of Matrix-Matrix Multiplication on Heterogeneous Clusters  

Microsoft Academic Search

The paper is devoted to scalability analysis of a typical linear algebra algorithm on heterogeneous clusters. We proof that traditional scalability metrics proposed for analysis of linear algebra algorithms is applicable on heterogeneous platform and investigate influence of three heterogeneous strategies of computation distribution to Scalable Universal Matrix Multiplication Algorithm (SUMMA) scalability.

Alexey Kalinov

2004-01-01

167

Transfer matrix and matrix Green function: the matching problem  

Microsoft Academic Search

The connection between the Green function and the transfer matrix is extended beyond the case of one single differential equation - e.g. a one band model. The Surface Green Function Matching analysis is thus performed in terms of transfer matrices when the Green functions involved are matrices. The practical use of the formalism is demonstrated by studying two physical problems.

H. Rodriguez-Coppola; V. R. Velasco; F. Garcia-Moliner; R. Pérez-Alvarez

1990-01-01

168

Little type IIB matrix model  

SciTech Connect

We study the zero-dimensional reduced model of D=6 pure super Yang-Mills theory and argue that the large N limit describes the (2,0) Little String Theory. The one-loop effective action shows that the force exerted between two diagonal blocks of matrices behaves as 1/r{sup 4}, implying a six-dimensional spacetime. We also observe that it is due to nongravitational interactions. We construct wave functions and vertex operators which realize the D=6 (2,0) tensor representation. We also comment on other little analogues of the IIB matrix model and Matrix Theory with less supercharges.

Kitazawa, Yoshihisa; Mizoguchi, Shun'ya [High Energy Accelerator Research Organization (KEK) Tsukuba, Ibaraki 305-0801 (Japan); Department of Particle and Nuclear Physics, Graduate University for Advanced Studies, Tsukuba, Ibaraki 305-0801 (Japan); Saito, Osamu [High Energy Accelerator Research Organization (KEK) Tsukuba, Ibaraki 305-0801 (Japan); Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan)

2006-08-15

169

Staggered weak matrix element miscellany  

NASA Astrophysics Data System (ADS)

I report on work, done with Rajan Gupta and Greg Kilcup, using staggered fermions to study weak matrix elements in quenched QCD. I give an update on the ?I = {1}/{2} rule and on matrix elements and relevant for ?'. I show results of a study of the dependence of BK on non-leading terms in the chiral expansion. I present our first results for BK from a quenched calculation at ß = 6.4 on 32 3 × 48 lattices, based o n an ensemble of 12 configurations.

Sharpe, Stephen R.

1991-05-01

170

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

171

Parallel Complexity of Matrix Multiplication  

Microsoft Academic Search

Effective design of parallel matrix multiplication algorithms relies on the consideration of many interdependent issues based on the underlying parallel machine or network upon which such algorithms will be implemented, as well as, the type of methodology utilized by an algorithm. In this paper, we determine the parallel complexity of multiplying two (not necessarily square) matrices on parallel distributed-memory machines

Eunice E. Santos

2003-01-01

172

Thermal Matrix for the Blind  

Microsoft Academic Search

The paper deals with the prototype of the Thermal Characters Matrix for the blind. The prosthesis is built up with the use of many miniature Peltier modules deposited on the common substrate. The surface of each Peltier micropump is a touch point, which demands the thermal stabilization. Miniature Peltier modules behave both as heat and cold generators. They are also

K. Boro; P. Bratek; A. Kos

173

The spinorial R-matrix  

NASA Astrophysics Data System (ADS)

The R-matrix acting in the tensor product of two spinor representation spaces of Lie algebra so(d) is considered thoroughly. The corresponding Yang-Baxter relation is proved and the underlying local Yang-Baxter equation is established.

Chicherin, D.; Derkachov, S.; Isaev, A. P.

2013-12-01

174

Energy Medicine and Matrix Regeneration  

Microsoft Academic Search

Energy medicine includes a variety of diagnostic and therapeutic tools that are becoming increasingly popular worldwide and that are steadily entering mainstream medicine. Matrix Regeneration is an approach that is emerging from our increasing understandings of how various forms of energy are used by the human body to regulate living processes such as healing. For example, an injury results in

James L. Oschman; Judy Kosovich

175

Estimating two-dimensional frequencies by matrix enhancement and matrix pencil  

Microsoft Academic Search

A new method, called the matrix enhancement and matrix pencil (MEMP) method, is presented for estimating two-dimensional (2-D) frequencies. In the MEMP method, an enhanced matrix is constructed from the data samples, and then the matrix pencil approach is used to extract out the 2-D sinusoids from the principal eigenvectors of the enhanced matrix. The MEMP method yields the estimates

Yingbo Hua

1992-01-01

176

Bayesian analysis of matrix normal graphical models  

PubMed Central

We present Bayesian analyses of matrix-variate normal data with conditional independencies induced by graphical model structuring of the characterizing covariance matrix parameters. This framework of matrix normal graphical models includes prior specifications, posterior computation using Markov chain Monte Carlo methods, evaluation of graphical model uncertainty and model structure search. Extensions to matrix-variate time series embed matrix normal graphs in dynamic models. Examples highlight questions of graphical model uncertainty, search and comparison in matrix data contexts. These models may be applied in a number of areas of multivariate analysis, time series and also spatial modelling.

Wang, Hao; West, Mike

2009-01-01

177

Immobilization of cellulase using porous polymer matrix  

SciTech Connect

A new method is discussed for the immobilization of cellulase using porous polymer matrices, which were obtained by radiation polymerization of hydrophilic monomers. In this method, the immobilized enzyme matrix was prepared by enzyme absorbtion in the porous polymer matrix and drying treatment. The enzyme activity of the immobilized enzyme matrix varied with monomer concentration, cooling rate of the monomer solution, and hydrophilicity of the polymer matrix, takinn the change of the nature of the porous structure in the polymer matrix. The leakage of the enzymes from the polymer matrix was not observed in the repeated batch enzyme reactions.

Kumakura, M.; Kaetsu, I.

1984-09-01

178

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

179

Extracellular Matrix and Heart Development  

PubMed Central

The extracellular matrix (ECM) of the developing heart contains numerous molecules that together form a dynamic environment that plays an active and crucial role in the regulation of cellular events. ECM molecules found in the heart include hyaluronan, fibronectin, fibrillin, proteoglycans, and collagens. Tight regulation of the spatiotemporal expression, and the proteolytic processing of ECM components by proteases including members of the ADAMTS family, is essential for normal cardiac development. Perturbation of expression of genes involved in matrix composition and remodeling can interfere with a myriad of events involved in the formation of the four-chambered heart and result in prenatal lethality and/or cardiac malformations as seen in humans with congenital heart disease (CHD). In this review we will briefly summarize what is known about the specific importance of some of the components of the ECM in relation to the cardiovascular development.

Lockhart, Marie; Wirrig, Elaine; Phelps, Aimee; Wessels, Andy

2011-01-01

180

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

181

The asymmetric ABAB matrix model  

NASA Astrophysics Data System (ADS)

In this letter, it is pointed out that the two-matrix model defined by the action S = ½(trA2 + trB2) - [(?A)/(4)]trA4 - [(?B)/(4)]trB4 - [(?)/(2)]tr(AB)2 can be solved in the large-N limit using a generalization of the solution of Kazakov and Zinn-Justin (who considered the symmetric case ?A = ?B). This model could have useful applications to 3D Lorentzian gravity.

Zinn-Justin, P.

2003-12-01

182

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

183

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

184

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

185

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

186

Matrix metalloproteinases and tumor metastasis  

Microsoft Academic Search

Functions of individual matrix metalloproteinases (MMPs) differentially expressed by tumor cells and stromal cells, are finely\\u000a regulated by their spatial as well as temporal interactions with distinct cellular and extracellular components of the tumor\\u000a microenvironment and also distant pre-metastatic sites. Certain aspects of MMP involvement in tumor metastasis such as tumor-induced\\u000a angiogenesis, tumor invasion, and establishment of metastatic foci at

Elena I. Deryugina; James P. Quigley

2006-01-01

187

Fiber bundles and matrix models  

SciTech Connect

We investigate the relationship between a gauge theory on a principal bundle and that on its base space. In the case where the principal bundle is itself a group manifold, we also study relations of those gauge theories with a matrix model obtained by dimensionally reducing them to zero dimensions. First, we develop the dimensional reduction of Yang-Mills (YM) theory on the total space to YM-Higgs theory on the base space for a general principal bundle. Second, we show a relationship that YM on an SU(2) bundle is equivalent to the theory around a certain background of YM-Higgs on its base space. This is an extension of our previous work [T. Ishii, G. Ishiki, S. Shimasaki, and A. Tsuchiya, J. High Energy Phys. 05 (2007) 014.], in which the same relationship concerning a U(1) bundle is shown. We apply these results to the case of SU(n+1) as the total space. By dimensionally reducing YM on SU(n+1), we obtain YM-Higgs on SU(n+1)/SU(n){approx_equal}S{sup 2n+1} and on SU(n+1)/(SU(n)xU(1)){approx_equal}CP{sup n} and a matrix model. We show that the theory around each monopole vacuum of YM-Higgs on CP{sup n} is equivalent to the theory around a certain vacuum of the matrix model in the commutative limit. By combining this with the relationship concerning a U(1) bundle, we realize YM-Higgs on SU(n+1)/SU(n){approx_equal}S{sup 2n+1} in the matrix model. We see that the relationship concerning a U(1) bundle can be interpreted as Buscher's T-duality.

Ishii, Takaaki; Ishiki, Goro; Shimasaki, Shinji; Tsuchiya, Asato [Department of Physics, Graduate School of Science Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2008-06-15

188

Diabetic nephropathy and extracellular matrix.  

PubMed

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

Kolset, S O; Reinholt, F P; Jenssen, T

2012-12-01

189

Fast Parallel Realization of Matrix Multiplication.  

National Technical Information Service (NTIS)

Fast parallel matrix multiplication algorithms in SIMD (Single-Instruction-Multiple-Data) and MIMD (MUltiple-Instruction-Multiple-data) modes are described for implementation in a parallel-binary matrix processing system with facilities for bit-wise paral...

E. V. Krishnamurthy R. Klette

1979-01-01

190

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

191

Graphical Evaluation of Relativistic Matrix Elements.  

National Technical Information Service (NTIS)

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 s...

K. N. Huang

1978-01-01

192

Design of Interfaces in Metal Matrix Composites.  

National Technical Information Service (NTIS)

The main goal of this research was to optimize the interface properties in metal matrix composites by lattice matching the matrix and the dispersoids. Stable, coherent dispersoids can be achieved by mechanically alloying lattice-matched dispersoids into m...

H. L. Marcus Z. Eliezer

1993-01-01

193

Continuously Formed Metal Matrix Composite Shapes.  

National Technical Information Service (NTIS)

Metal matrix composites having open or closed channels extending longitudinal through the length of the composite as well as methods and apparatus for forming the same are described. The shaped metal matrix composites are made of continuous fiber reinforc...

B. L. Gordon G. W. Wolfe

2004-01-01

194

Human Performance Evaluation of Matrix Displays.  

National Technical Information Service (NTIS)

The purpose of this research program was to investigate the influence of matrix display design parameters on operator target recognition performance. Five quantitative matrix display variables (emitter size, on-time, refresh-rate, viewing distance and emi...

G. E. Corrick L. A. Scanlon

1978-01-01

195

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

196

Ceramic matrix composite-metal brazed joints  

Microsoft Academic Search

A silicon nitride fibre-reinforced cordierite glass ceramic matrix composite has been brazed to titanium and stainless steel in argon with four different interlayer materials, copper, nickel, tungsten and a metal matrix composite (mmc). Joints were tested in shear and all but one failed in the ceramic composite. The highest strength joint, using a metal matrix interlayer to join cmc to

D. G. Dixon

1995-01-01

197

Analytic Properties of the Phase Matrix.  

National Technical Information Service (NTIS)

The author writes the S matrix in the form S=exp (i(eta)) and he considers the analytic properties of the 2-body matrix elements of eta as a function of two complex variables. It is found that the 2-body matrix elements of eta have analytic properties sim...

A. J. Dragt

1970-01-01

198

Analytic approximation of matrix functions in Lp  

Microsoft Academic Search

We consider the problem of approximation of matrix functions of class Lp on the unit circle by matrix functions ana- lytic in the unit disk in the norm of Lp, 2 p < 1. For an m n matrix function in Lp, we consider the Hankel operator H : Hq(Cn) ! H2 (C m), 1=p + 1=q = 1=2. It

Laurent Baratchart; F. L. Nazarov; V. V. Peller

2009-01-01

199

Analytic Modeling with Matrix Exponential Distributions  

Microsoft Academic Search

In this paper, we review matrix exponential distributions and Linear Algebra Queueing Theory. The ma- trix exponential distribution is very powerful and has useful properties that allow it to be used in the construction of gen- eral analytic models. We show how common distributions can be represented exactly as matrix exponential distribu- tions. We also show how matrix exponential distributions

K. Mitchell; A. van de Liefvoort

1995-01-01

200

Efficient Procedures for Using Matrix Algorithms  

Microsoft Academic Search

A set of basic procedures for constructing matrix multiplication algorithms is defined. Five classes of composite matrix multiplication algorithms are considered and an optimal strategy is presented for each class. Instances are given of improvements in arithmetic cost over Strassen's method for multiplying square matrices. Best and worst case cost coefficients for matrix multiplication are given.

Patrick C. Fischer; Robert L. Probert

1974-01-01

201

Optimizing Sparse Matrix Vector Multiplication on SMP  

Microsoft Academic Search

We describe optimizations of sparse matrix-vector multiplication on uniprocessors and SMPs. The optimization techniques include register blocking, cache blocking, and matrix reordering. We focus on optimizations that improve performance on SMPs, in particular, matrix reordering implemented using two different graph algorithms. We present a performance study of this algorithmic kernel, showing how the optimization techniques affect absolute performance and scalability,

Im Eun-jin; Katherine A. Yelick

1999-01-01

202

Bayesian Inference for a Covariance Matrix  

Microsoft Academic Search

A flexible class of prior distributions is proposed, for the covariance matrix of a multivariate normal distribution, yielding much more general hierarchical and empirical Bayes smoothing and inference, when compared with a conjugate analysis involving an inverted Wishart distribution. A likelihood approximation is obtained for the matrix logarithm of the covariance matrix, via Bellman's iterative solution to a Volterra integral

Tom Leonard; John S. J. Hsu

1992-01-01

203

Computing the entropy of a large matrix  

NASA Astrophysics Data System (ADS)

Given a large real symmetric, positive semidefinite matrix, the goal of this paper is to show how a numerical approximation of the von Neumann entropy of the matrix can be computed in an efficient way, without relying on matrix diagonalization. An application from quantum optics dealing with the entanglement between photons illustrates the new algorithm.

Wihler, Thomas P.; Bessire, Bänz; Stefanov, André

2014-06-01

204

A matrix formulation of Kaiser's varimax criterion  

Microsoft Academic Search

Kaiser has given the varimax criterion for the solution of the rotation problem in factor analysis as well as a practical computational procedure for maximizing this criterion. In the present paper, the maximization condition is shown as a matrix equation involving only the unknown orthogonal rotation matrix. This matrix equation can be solved iteratively as a sequence of symmetric eigenproblems.

Richard J. Sherin

1966-01-01

205

A perturbation method for optimizing matrix stability  

Microsoft Academic Search

We present the first practical perturbation method for optimizing matrix stability using spectral abscissa minimization. Using perturbation theory for a matrix with simple eigenvalues and coupling this with linear programming, we successively reduce the spectral abscissa of a matrix until it reaches a local minimum. Optimality conditions for a local minimizer of the spectral abscissa are provided and proved for

Nian Li; Joseph M. Steiner

2011-01-01

206

Lehmer Matrix and Its Recursive Analogue.  

National Technical Information Service (NTIS)

This paper considers the Lehmer matrix and its recursive analogue. The determinant of Lehmer matrix is derived explicitly by both its LU and Cholesky factorizations. We further define a generalized Lehmer matrix with (i; j) entries gij = min (ui+1, uj+1) ...

E. Kilic P. Stanica

2010-01-01

207

Step Towards Real Life Matrix  

NSDL National Science Digital Library

This article from New Scientist News discusses the possibility that Sony might be able to develop a real life matrix. That is, people may be able to watch movies and play computer games in which they can also get to smell, taste and perhaps even feel things. The prospect was raised by Sony's approval for a patent on a device for transmitting sensory data directly into the human brain. The author discusses how this device might work but notes that Sony declined New Scientist's request for an interview with the inventor. If the method described by Sony works, the author speculates on its uses in research and medicine.

208

Matrix management for aerospace 2000  

NASA Technical Reports Server (NTRS)

The martix management approach to program management is an organized effort for attaining program objectives by defining and structuring all elements so as to form a single system whose parts are united by interaction. The objective of the systems approach is uncompromisingly complete coverage of the program management endeavor. Starting with an analysis of the functions necessary to carry out a given program, a model must be defined; a matrix of responsibility assignment must be prepared; and each operational process must be examined to establish how it is to be carried out and how it relates to all other processes.

Mccarthy, J. F., Jr.

1980-01-01

209

Brain Extracellular Matrix in Neurodegeneration  

PubMed Central

The role of extracellular matrix (ECM) in neurological development, function and degeneration has evolved from a simplistic physical adhesion to a system of intricate cellular signaling. While most cells require ECM adhesion to survive, it is now clear that differentiated function is intimately dependent upon cellular interaction with the ECM. Therefore, it is not surprising that the ECM is increasingly found to be involved in the enigmatic process of neurodegeneration. Descriptive studies of human neurodegenerative disorders and experimental studies of animal models of neurodegeneration have begun to define potential mechanisms of ECM disruption that can lead to synaptic and neuronal loss.

Bonneh-Barkay, Dafna; Wiley, Clayton A.

2009-01-01

210

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

211

Cosmology and the S matrix  

NASA Astrophysics Data System (ADS)

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

2005-03-01

212

Cell-Matrix Adhesions in 3D  

PubMed Central

Cells in a three-dimensional (3D) extracellular matrix environment often display different properties and behavior compared to cells cultured on a two-dimensional (2D) substrate. Recent studies characterizing the cell-matrix adhesions formed by cells within a 3D matrix have arrived at contradictory conclusions regarding the presence and composition of adhesions. Here we review this literature, and provide a comparative compilation of information found in published studies from the 3D cell-matrix adhesion field in order to identify shared and divergent conclusions and conceptually important areas that require further research. Although there is a general consensus that discrete cell-matrix adhesions exist in various 3D matrix environments, there are specific exceptions, particularly in cells undergoing amoeboid migration. There are also technical issues to consider when imaging adhesions in 3D matrix; for example, over-expression of a cytoskeletal cell adhesion component can potentially cloud the visualization of adhesions and even alter the mode of cell migration. Properties such as stiffness and local matrix topography may also affect the composition of cell-matrix adhesions. For example, even though cells contain integrin-based 3D adhesions, there can be substantial variability within these adhesions in the presence of force-dependent cytoskeletal components such as vinculin. These new findings and ideas provide promising new leads for understanding the regulation and function of cell-matrix adhesions in 3D matrix.

Harunaga, Jill S.; Yamada, Kenneth M.

2011-01-01

213

Physical controls on matrix mineralization  

NASA Astrophysics Data System (ADS)

During biomineral formation, protein matrices impose order on nucleating mineral phases. While many studies have examined the structural relationships between mineral and matrix, few have explored the energetics. To address this gap we use in situ TEM and AFM to investigate calcium phosphate nucleation and growth in collagen and amelogenin matrices. In situ TEM results indicate that, in the absence of calcium, amelogenin nanospheres are loose aggregates of oligomers, while in the presence of calcium phosphate solution, can form chain-like structures and become mineralized with an amorphous phase before the appearance of crystalline phases. Results on collagen reveal the evolution of nucleation pathways from direct to indirect with increasing supersaturation and analysis of nucleation rates using classical theory demonstrates a reduction in interfacial energy due to matrix-mineral interactions. However, the calculated thermodynamic barriers are in contradiction to the observed pathways and well in excess of sensible values. We present a model based on cluster aggregation within the classical context that reconciles experiment and theory.

Tao, Jinhui; Nielsen, Mike; de Yoreo, Jim

2013-03-01

214

Many Body Density Matrix Theory  

NASA Astrophysics Data System (ADS)

One fundamental limitation of quantum chemical methods is the accuracy of the approximate many-body theoretical framework. Accurate many-body formalisms for quantum chemical methods do exist, but these methods are computationally very expensive. Methods also exist that are much less computationally expensive such as Hatree-Fock, Density Functional and the Hybrid Functional theories, but at a reduced representation of the exact many-body ground state. This severely limits either the system size that can be addressed accurately, or the accuracy of the representation. What is needed is a method that represents the many-body ground states accurately, but with a low computational cost. Recently, a method for determining the response, to any order of the perturbation, within the density matrix formalism has been discovered. This method opens up the possibility of computing the variational many-body ground states to unprecedented accuracy within a simplified computational approach. We report on the theoretical development of this methodology, which we refer to as Many Body Density Matrix Theory. This theory has many significant advantages over existing methods. One, its computational cost is equivalent to Hartree-Fock or Density Functional theory. Two it is a variational upper bound to the exact many-body ground state energy. Three, like Hartree-Fock, it has no self-interaction. And four, it is size extensive.

Tymczak, C. J.

2011-03-01

215

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

216

On the matrix formulation of Kaiser's varimax criterion  

Microsoft Academic Search

The author provides a full-fledged matrix derivation of Sherin's matrix formulation of Kaiser's varimax criterion. He uses matrix differential calculus in conjunction with the Hadamard (or Schur) matrix product. Two results on Hadamard products are presented.

H. Neudecker

1981-01-01

217

On the Matrix Formulation of Kaiser's Varimax Criterion.  

ERIC Educational Resources Information Center

A full-fledged matrix derivation of Sherin's matrix formulation of Kaiser's varimax criterion is provided. Matrix differential calculus is used in conjunction with the Hadamard (or Schur) matrix product. Two results on Hadamard products are presented. (Author/JKS)

Neudecker, H.

1981-01-01

218

Necessary and sufficient condition for perfect reconstruction matrix filter banks  

NASA Astrophysics Data System (ADS)

A matrix filter is a linear and time-invariant operator on the space of vector-valued signals. Matrix filter bank is the generalization of filter bank. A perfect reconstruction matrix filter bank consists of an analysis matrix filter bank and a synthesis matrix filter bank. In the theory of filter design, generating a perfect reconstruction matrix filter bank from a given lowpass matrix filter is considered. Such a lowpass matrix filter is called a primary matrix filter. In this paper, we give a necessary and sufficient condition for a lowpass matrix filter being primary and discuss the relation between perfect reconstruction matrix filter bank and biorthogonal multiwavelet.

Wang, Jianzhong

1999-10-01

219

Light-cone matrix product  

SciTech Connect

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

Hastings, M. B. [Microsoft Research, Station Q, CNSI Building, University of California, Santa Barbara, California 93106 (United States)

2009-09-15

220

Bayes linear covariance matrix adjustment  

NASA Astrophysics Data System (ADS)

In this thesis, a Bayes linear methodology for the adjustment of covariance matrices is presented and discussed. A geometric framework for quantifying uncertainties about covariance matrices is set up, and an inner-product for spaces of random matrices is motivated and constructed. The inner-product on this space captures aspects of our beliefs about the relationship between covariance matrices of interest to us, providing a structure rich enough for us to adjust beliefs about unknown matrices in the light of data such as sample covariance matrices, exploiting second-order exchangeability and related specifications to obtain representations allowing analysis. Adjustment is associated with orthogonal projection, and illustrated with examples of adjustments for some common problems. The problem of adjusting the covariance matrices underlying exchangeable random vectors is tackled and discussed. Learning about the covariance matrices associated with multivariate time series dynamic linear models is shown to be amenable to a similar approach. Diagnostics for matrix adjustments are also discussed.

Wilkinson, Darren J.

1995-12-01

221

Thermoplastic matrix composite processing model  

NASA Technical Reports Server (NTRS)

The effects the processing parameters pressure, temperature, and time have on the quality of continuous graphite fiber reinforced thermoplastic matrix composites were quantitatively accessed by defining the extent to which intimate contact and bond formation has occurred at successive ply interfaces. Two models are presented predicting the extents to which the ply interfaces have achieved intimate contact and cohesive strength. The models are based on experimental observation of compression molded laminates and neat resin conditions, respectively. Identified as the mechanism explaining the phenomenon by which the plies bond to themselves is the theory of autohesion (or self diffusion). Theoretical predictions from the Reptation Theory between autohesive strength and contact time are used to explain the effects of the processing parameters on the observed experimental strengths. The application of a time-temperature relationship for autohesive strength predictions is evaluated. A viscoelastic compression molding model of a tow was developed to explain the phenomenon by which the prepreg ply interfaces develop intimate contact.

Dara, P. H.; Loos, A. C.

1985-01-01

222

Fission Matrix Capability for MCNP Monte Carlo  

NASA Astrophysics Data System (ADS)

We describe recent experience and results from implementing a fission matrix capability into the MCNP Monte Carlo code. The fission matrix can be used to provide estimates of the fundamental mode fission distribution, the dominance ratio, the eigenvalue spectrum, and higher mode forward and adjoint eigenfunctions of the fission neutron source distribution. It can also be used to accelerate the convergence of the power method iterations and to provide basis functions for higher-order perturbation theory. The higher-mode fission sources can be used in MCNP to determine higher-mode forward fluxes and tallies, and work is underway to provide higher-mode adjoint-weighted fluxes and tallies. Past difficulties and limitations of the fission matrix approach are overcome with a new sparse representation of the matrix, permitting much larger and more accurate fission matrix representations. The new fission matrix capabilities provide a significant advance in the state-of-the-art for Monte Carlo criticality calculations.

Brown, Forrest; Carney, Sean; Kiedrowski, Brian; Martin, William

2014-06-01

223

PROLOG Implementation of a Tabular Bottom-Up Recognizer.  

National Technical Information Service (NTIS)

A 'double-dotted' algorithm of parsing and recognizing for context free grammars not necessarily in Chomsky normal form has been developed recently by one of the authors (see PB90-211996). The algorithm is essentially parallel. The present note is devoted...

P. Kruszynski J. P. M. de Vreught

1991-01-01

224

Developments in south Texas in 1979. [Tabular data and map  

Microsoft Academic Search

The South Texas report includes 58 counties in Texas Railroad Districts 1, 2, and 4 and parts of the Texas offshore. District 1 exploration activity increased 8.9% from 1978. However, the success rate was down from 30.7% in 1978 to 23.1% for this year. Drilling for Upper Cretaceous pays was the focus of activity in 1979. Average well depth was

Fergeson

1980-01-01

225

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

226

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

227

Population Change and California's Future. Detailed Tabular Projections.  

ERIC Educational Resources Information Center

This document consists entirely of 132 tables which present statistics on the projected population size of 12 racial and ethnic groups in California: non-Hispanic Whites; Blacks; Hispanics; Chinese; Filipinos; Asian Indians; Japanese; Koreans; Southeast Asians; Vietnamese; Other Asians; and other groups. An accompanying report deals with these…

Bouvier, Leon F.; Martin, Philip

228

Model-based transductive learning of the kernel matrix  

Microsoft Academic Search

This paper addresses the problem of transductive learning of the kernel matrix from a probabilistic per- spective. We deflne the kernel matrix as a Wishart process prior and construct a hierarchical generative model for kernel matrix learning. Speciflcally, we consider the target kernel matrix as a random matrix following the Wishart distribution with a positive deflnite parameter matrix and a

Zhihua Zhang; James T. Kwok; Dit-yan Yeung

2006-01-01

229

Projective Nonnegative Matrix Factorization with ?-Divergence  

Microsoft Academic Search

A new matrix factorization algorithm which combines two recently proposed nonnegative learning techniques is presented. Our\\u000a new algorithm, ?-PNMF, inherits the advantages of Projective Nonnegative Matrix Factorization (PNMF) for learning a highly orthogonal factor\\u000a matrix. When the Kullback-Leibler (KL) divergence is generalized to ?-divergence, it gives our method more flexibility in approximation. We provide multiplicative update rules for ?-PNMF and

Zhirong Yang; Erkki Oja

2009-01-01

230

Fast Rectangular Matrix Multiplication and Applications  

Microsoft Academic Search

First we study asymptotically fast algorithms for rectangular matrix multiplication. We begin with new algorithms for multiplication of ann×nmatrix by ann×n2matrix in arithmetic timeO(n?),?=3.333953…, which is less by 0.041 than the previous record 3.375477…. Then we present fast multiplication algorithms for matrix pairs of arbitrary dimensions, estimate the asymptotic running time as a function of the dimensions, and optimize the

Xiaohan Huang; Victor Y. Pan

1998-01-01

231

Recursiveness in matrix rational interpolation problems  

Microsoft Academic Search

We consider the problem of computing solutions to a variety of matrix rational interpolation problems. These include the partial realization problem for matrix power series and Newton-Padé, Hermite-Padé, simultaneous Padé, M-Padé and multipoint Padé approximation problems along with their matrix generalizations. A general recurrence relation is given for solving these problems. Unlike other previous recursive methods, our recurrence works along

Bernhard Beckermann; George Labahn

1997-01-01

232

Rank-Sparsity Incoherence for Matrix Decomposition  

Microsoft Academic Search

Suppose we are given a matrix that is formed by adding an unknown sparse\\u000amatrix to an unknown low-rank matrix. Our goal is to decompose the given matrix\\u000ainto its sparse and low-rank components. Such a problem arises in a number of\\u000aapplications in model and system identification, and is NP-hard in general. In\\u000athis paper we consider a convex

Venkat Chandrasekaran; Sujay Sanghavi; Pablo A. Parrilo; Alan S. Willsky

2009-01-01

233

Solitons and giants in matrix models  

Microsoft Academic Search

We present a method for solving BPS equations obtained in the collective-field approach to matrix models. The method enables us to find BPS solutions and quantum excitations around these solutions in the one-matrix model, and in general for the Calogero model. These semiclassical solutions correspond to giant gravitons described by matrix models obtained in the framework of AdS\\/CFT correspondence. The

Ivan Andric; Larisa Jonke; Danijel Jurman

2006-01-01

234

Reconstituted asbestos matrix for fuel cells  

NASA Technical Reports Server (NTRS)

Method is described for reprocessing commercially available asbestos matrix stock to yield greater porosity and bubble pressure (due to increased surface tension), improved homogeneity, and greater uniformity.

Mcbryar, H.

1975-01-01

235

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

236

Integrated-optical approaches to matrix multiplication  

NASA Technical Reports Server (NTRS)

The solution of matrix equations is essential to carrying out a large variety of control algorithms and to reducing certain types of data such as the output of a multispectral sensor array. Optical techniques and, in particular, integrated-optical circuits (IOC's) can provide compact, low-power devices for performing the mitrix multiplications necessary for the solution of these problems. A specific IOC for performing vector-matrix multiplication and several approaches to the design of IOC's for matrix-matrix multiplication will be discussed.

Verber, C. M.; Kenan, R. P.

1984-01-01

237

Matrix Metalloprotienases and its inhibitors: An insight  

PubMed Central

Periodontal disease progression involves degradation of the collagenous matrix by a group of enzymes known as the matrix metalloprotienases. These matrix metalloprotienases are secreted by the polymorphonuclear leukocytes, macrophages, fibroblasts, bone, epithelial and endothelial cells. These molecules have involvement in both physiological and pathological processes. It is shown that periodontal disease occurs when there is an imbalance between the activated metalloprotienases and their endogenous inhibitors. These can be modified by exogenous inhibitors like bisphosphonates, tetracyclines, etc. How to cite the article: Kumar P, Kumar L, Murthy S, Gurudath G. Matrix Metalloprotienases and its inhibitors: An insight. J Int Oral Health 2014;6(1):127-9.

Kumar, Parimala; Kumar, Laxmish; Murthy, Srinivas; Gurudath, G

2014-01-01

238

A new continuum limit of matrix models  

NASA Astrophysics Data System (ADS)

We define a new scaling limit of matrix models which can be related to the method of causal dynamical triangulations (CDT) used when investigating two-dimensional quantum gravity. Surprisingly, the new scaling limit of the matrix models is also a matrix model, thus explaining why the recently developed CDT continuum string field theory [J. Ambjørn, R. Loll, Y. Watabiki, W. Westra, S. Zohren, arXiv: 0802.0719] has a matrix-model representation [J. Ambjørn, R. Loll, Y. Watabiki, W. Westra, S. Zohren, arXiv: 0804.0252].

Ambjørn, J.; Loll, R.; Watabiki, Y.; Westra, W.; Zohren, S.

2008-12-01

239

Silicon carbide matrix for fuel cells  

SciTech Connect

This patent describes a fuel cell comprising: a pair of spaced apart gas diffusion electrodes; a porous electrolyte retaining matrix confined in the space between the electrodes. The matrix has a porosity of at least 38 percent and consists essentially of 70 to 90 weight percent silicon carbide and a balance of hydrophilic polyethersulfone as a binder; and phosphoric acid electrolyte disposed within the matrix. The matrix has the characteristic that it remains physically intact for at least 17,000 hours of fuel cell operation at 375/sup 0/F.

Trocciola, J.C.; Powers, J.; Martin, R.G.

1987-09-22

240

Extracellular Matrix: Functions in the Nervous System  

PubMed Central

An astonishing number of extracellular matrix glycoproteins are expressed in dynamic patterns in the developing and adult nervous system. Neural stem cells, neurons, and glia express receptors that mediate interactions with specific extracellular matrix molecules. Functional studies in vitro and genetic studies in mice have provided evidence that the extracellular matrix affects virtually all aspects of nervous system development and function. Here we will summarize recent findings that have shed light on the specific functions of defined extracellular matrix molecules on such diverse processes as neural stem cell differentiation, neuronal migration, the formation of axonal tracts, and the maturation and function of synapses in the peripheral and central nervous system.

Barros, Claudia S.; Franco, Santos J.; Muller, Ulrich

2011-01-01

241

Fragmentation of extracellular matrix by hypochlorous acid.  

PubMed Central

The interaction of extracellular matrix with cells regulates their adhesion, migration and proliferation, and it is believed that damage to vascular matrix components is a factor in the development of atherosclerosis. Evidence has been provided for a role for the haem enzyme MPO (myeloperoxidase), released by activated monocytes (and possibly macrophages), in oxidative events within the artery wall. As MPO is released extracellularly, and is highly basic, it might be expected to associate with poly-anionic matrix components thereby localizing damage to these materials. In this study the reaction of the MPO-derived oxidant hypochlorous acid (HOCl) with extracellular matrix from vascular smooth muscle cells and healthy pig arteries has been examined. HOCl is rapidly consumed by such matrix samples, with the formation of matrix-derived chloramines or chloramides. The yield of these intermediates increases with HOCl dose. These materials undergo a time- and temperature-dependent decay, which parallels the release of sugar and protein components from the treated matrix, consistent with these species being important intermediates. Matrix damage is enhanced by species that increase chloramine/chloramide decomposition, with copper and iron ions being effective catalysts, and decreased by compounds which scavenge chloramines/chloramides, or species derived from them. The effect of such matrix modifications on cellular behaviour is poorly understood, though it is known that changes in matrix materials can have profound effects on cell adhesion, proliferation, growth and phenotype. The observed matrix modifications reported here may therefore modulate cellular behaviour in diseases such as atherosclerosis where MPO-derived oxidants are generated.

Woods, Alan A; Davies, Michael J

2003-01-01

242

Analysis of the Requirements Correlation Matrix (RCM) and Baseline Correlation Matrix (BCM).  

National Technical Information Service (NTIS)

This purpose of this thesis was to analyze the Requirements Correlation Matrix (RCM) and Baseline Correlation Matrix (BCM). The specific question addressed by the research was What improvements can be made to better define and document the operational per...

D. K. Struck

1990-01-01

243

Matrix Metalloproteinases and Angiogenic Factors  

PubMed Central

The aim of the present study was to investigate whether biomarkers improve the prediction of recurrence-free, disease-specific, and overall survival in patients with clinically localized prostate cancer. A tissue microarray was constructed from prostate specimens of 278 patients who underwent open radical retropubic prostatectomy for clinically localized prostate cancer. For immunohistochemical studies, antibodies were used against matrix metalloproteinase (MMP)?2, MMP-3, MMP-7, MMP-9, MMP-13, and MMP-19, as well as against vascular endothelial growth factor, hypoxia-induced factor 1?, basic fibroblast growth factor, and cluster of differentiation 31. Univariate and multivariable analyses were performed to evaluate the potential predictors of overall, disease-specific, and recurrence-free survival. In univariate analysis of patients with clinically organ-confined prostate cancer, only higher expression levels of MMP-9 (hazard ratio [0.6], 95% CI 0.45?0.8) had a protective effect in terms of overall survival. This positive effect of high MMP-9 expression was also observed for recurrence-free (HR 0.88, 95% CI 0.78?0.99) and disease-specific survival (HR 0.5, 95% CI 0.36?0.73). In multivariable analysis, none of these potential markers was found to be an independent prognostic factor of survival. Of all MMPs and angiogenic factors tested, MMP-9 expression has the potential as a prognostic marker in patients undergoing radical prostatectomy for clinically organ-confined cases of prostate cancer.

Boxler, Silvan; Djonov, Valentin; Kessler, Thomas M.; Hlushchuk, Ruslan; Bachmann, Lucas M.; Held, Ulrike; Markwalder, Regula; Thalmann, George N.

2010-01-01

244

Molecular Wound Assessments: Matrix Metalloproteinases  

PubMed Central

Significance The process of wound healing includes the regulated destruction of proteins via enzymes called proteinases. However, when the proteolytic process becomes excessive, pro-healing factors are destroyed and the wound healing process stalls. Matrix metalloproteinases (MMPs) are one key class of proteinases that have been observed to be elevated in many cases of failed wound healing. Recent Advances Two key advances have been made in recent years. First is that, until recently, MMPs were only implicated in impaired healing of chronic wounds. Measurements of MMPs in wound fluids and serum from individuals with acute traumatic wounds have revealed that elevated MMPs are predictive of both impaired healing and of dehiscence of surgically closed wounds. The second advance is in the development of at least three clinically viable methods for measuring MMPs at the point of care. Critical Issues At present there is no objective method of determining proteinase levels within a wound. Since elevated MMPs have now been shown to be predictive of dehiscence in surgically closed acute wounds, a new clinical utility for measuring MMPs has been established. With the advent of several new technologies to measure MMPs, the translation of this valuable molecular knowledge into improved therapeutic regimens is nearly complete. Future Directions The clinical utility of measuring MMPs continues to expand and be further validated with each new investigation. The tools that will enable clinicians to leverage this valuable information are nearing maturity and integration into the clinic.

Gibson, Daniel J.; Schultz, Gregory S.

2013-01-01

245

TRASYS form factor matrix normalization  

NASA Technical Reports Server (NTRS)

A method has been developed for adjusting a TRASYS enclosure form factor matrix to unity. This approach is not limited to closed geometries, and in fact, it is primarily intended for use with open geometries. The purpose of this approach is to prevent optimistic form factors to space. In this method, nodal form factor sums are calculated within 0.05 of unity using TRASYS, although deviations as large as 0.10 may be acceptable, and then, a process is employed to distribute the difference amongst the nodes. A specific example has been analyzed with this method, and a comparison was performed with a standard approach for calculating radiation conductors. In this comparison, hot and cold case temperatures were determined. Exterior nodes exhibited temperature differences as large as 7 C and 3 C for the hot and cold cases, respectively when compared with the standard approach, while interior nodes demonstrated temperature differences from 0 C to 5 C. These results indicate that temperature predictions can be artificially biased if the form factor computation error is lumped into the individual form factors to space.

Tsuyuki, Glenn T.

1992-01-01

246

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.

Berretta, Sabina

2011-01-01

247

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

Microsoft Academic Search

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

Kathleen L. Caldwell; Kermit K. Murray

1998-01-01

248

Parallel Matrix-Matrix Multiplication Based on HPL with a GPU-Accelerated PC Cluster  

Microsoft Academic Search

In this paper, we propose an approach for significantly improving the performance of parallel matrix-matrix multiplication using a GPU-accelerated cluster. For one node, we implement a CPUs-GPU parallel double-precision general matrix-matrix multiplication (dgemm) operation and achieve a performance improvement of 32% as compared to the GPU-only case and 56% as compared to the CPUs-only case. For the entire cluster, we

Qin Wang; Junichi Ohmura; Shan Axida; Takefumi Miyoshi; Hidetsugu Irie; Tsutomu Yoshinaga

2010-01-01

249

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

250

Analytic matrix functions with prescribed local data  

Microsoft Academic Search

In this paper we consider the problem of construction of a matrix valued analytic function given its local data in a set of isolated points. The local data of an analytic matrix function can be given in different forms: (a) in the form of Jordan chains; (b) in the form of right (or left) local polynomial divisors; (c) in the

I. Gohberg; L. Rodman

1981-01-01

251

Semidefinite perturbations of analytic Hermitian matrix functions  

Microsoft Academic Search

In this paper we consider the behaviour of a real eigenvalue of an analytic Hermitian matrix valued function under perturbation with a positive semidefinite analytic Hermitian matrix valued function. We extend previous results on perturbation with positive definite functions to the positive semidefinite case.

A. C. M. Ran; L. Rodman

1989-01-01

252

Perturbation of analytic hermitian matrix functions  

Microsoft Academic Search

The behaviour of real eigenvalues of selfadjoint analytic matrix valued functions under small selfadjoint analytic perturbations is studied. Attention is paid mainly to the case when the perturbation is definite (or semidefi-nite). Earlier results of the authors concerning matrix polynomials of first degree are extended to the case of analytic functions.

I. Gohberg; P. Lancaster; L. Rodman

1985-01-01

253

Matrix Correction for PIXE in Biomedical Samples.  

National Technical Information Service (NTIS)

This report describes the programs MATRIX2, STPPWRF2 and MUROFIT, which are used for the calculation of the matrix correction factors, which must be applied to concentrations determined by PIXE (Proton induced X-ray emission). The correction takes into ac...

D. Heck E. Rokita

1985-01-01

254

Efficient Matrix Multiplication on Wireless Sensor Networks  

Microsoft Academic Search

Wireless Sensor Networks (WSN for short) have been widely used for data collecting and processing in various applications. This paper studies the problem of how to efficiently realize matrix multiplication on a WSN. Based on a widely accepted model of WSNs, we show the lower bound on the number of parallel steps needed by any algorithm for ntimesn matrix multiplication

Hong Shen; Jing Chen

2008-01-01

255

Recursive Array Layouts and Fast Matrix Multiplication  

Microsoft Academic Search

The performance of both serial and parallel implementations of matrix multiplication is highly sensitive to memory system behavior. False sharing and cache conflicts cause traditional column-major or row-major array layouts to incur high variability in memory system performance as matrix size varies. This paper investigates the use of recursive array layouts to improve performance and reduce variability. Previous work on

Siddhartha Chatterjee; Alvin R. Lebeck; Praveen K. Patnala; Mithuna Thottethodi

2002-01-01

256

Adaptive Matrix Multiplication in Heterogeneous Environments  

Microsoft Academic Search

In this paper, an adaptive matrix multiplication algo- rithm for dynamic heterogeneous environments is devel- oped and evaluated. Unlike the state-of-the-art approaches, where load balancing is achieved through unequal distri- bution of the matrix data among the heterogeneous nodes, the matrices in our approach are partitioned into blocks of equal size. Task allocation and the block size are adapted during

Bo Hong; Viktor K. Prasanna

2002-01-01

257

Matrix Algebra, Computers and Secret Coding.  

ERIC Educational Resources Information Center

Presents a method for using matrix algebra and computers to encode and decode secret messages. Provides examples of coding procedures, a short review of matrix multiplication, and a BASIC program for use with secret messages containing up to 1000 numbers. (RT)

Meyer, Ruth A.; Riley, James E.

1989-01-01

258

Boolean Matrix Multiplication and Transitive Closure  

Microsoft Academic Search

Arithmetic operations on matrices are applied to the problem of finding the transitive closure of a Boolean matrix. The best transitive closure algorithm known, due to Munro, is based on the matrix multiplication method of Strassen. We show that his method requires at most O(n? ¿ P(n)) bitwise operations, where ? = log27 and P(n) bounds the number of bitwise

Michael J. Fischer; Albert R. Meyer

1971-01-01

259

Scalability of Parallel Algorithms for Matrix Multiplication  

Microsoft Academic Search

A number of parallel formulations of dense matrix multiplication algorithm have been developed. For arbitrarily large number of processors, any of these algorithms or their variants can provide near linear speedup for sufficiently large matrix sizes and none of the algorithms can be clearly claimed to be superior than the others. In this paper we analyze the performance and scalability

Anshul Gupta; Vipin Kumar

1993-01-01

260

Implementation of Strassen's algorithm for matrix multiplication  

Microsoft Academic Search

In this paper we report on the development of an efficient and portable implementation of Strassen's matrix multiplication algorithm for matrices of arbitrary size. Our technique for defining the criterion which stops the recursions is more detailed than those generally used, thus allowing enhanced performance for a larger set of input sizes. In addition, we deal with odd matrix dimensions

Steven Huss-Lederman; Elaine M. Jacobson; Anna Tsao; Thomas Turnbull; Jeremy R. Johnson

1996-01-01

261

Fast Polar Decomposition of an Arbitrary Matrix  

Microsoft Academic Search

The polar decomposition of an m x n matrix A of full rank, where rn n, can be computed using a quadratically convergent algorithm ofHigham SIAMJ. Sci. Statist. Comput., 7 (1986), pp. 1160-1174). The algorithm is based on a Newton iteration involving a matrix inverse. It is shown how, with the use of a preliminary complete orthogonal decomposition, the algorithm

Nicholas J. Higham; Robert S. Schreiber

1990-01-01

262

Systolic triple-matrix product calculations  

NASA Technical Reports Server (NTRS)

In order to handle arbitrary-sized matrices with fixed-sized optical matrix processors, it is necessary to expand or contract the problem to fit the processor. This preprocessing is examined. It is applied to the type of triple-matrix product calculation needed for Kalman filtering. Emphasis will be placed on systolic-type processors.

Caulfield, H. J.; Verber, C. M.; Stermer, R. L.

1984-01-01

263

Communication efficient matrix multiplication on hypercubes  

Microsoft Academic Search

In this paper we present an efficient dense matrix multiplication algorithm for distributed memory computers with a hypercube topology. The proposed algorithm performs better than all previously proposed algorithms for a wide range of matrix sizes and number of processors, especially for large matrices. We analyze the performance of the algorithms for two types of hypercube architectures, one in which

Himanshu Gupta; P. Sadayappan

1994-01-01

264

Communication-Efficient Matrix Multiplication on Hypercubes  

Microsoft Academic Search

In this paper we present an efficient dense matrix multiplication algorithm for distributed memory computers with a hypercube topology. The proposed algorithm performs better than all previously proposed algorithms for a wide range of matrix sizes and number of processors, especially for large matrices. We analyze the performance of the algorithms for two types of hypercube architectures, one in which

Himanshu Gupta; P. Sadayappan

1996-01-01

265

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

266

The Molecules of the Cell Matrix.  

ERIC Educational Resources Information Center

Cytoplasmic proteins form a highly structured yet changeable matrix that affects cell shape, division, motion, and transport of vesicles and organelles. Types of microfilaments, research techniques, actin and myosin, tumor cells, and other topics are addressed. Evidence indicates that the cell matrix might have a bearing on metabolism. (DH)

Weber, Klaus; Osborn, Mary

1985-01-01

267

Iterative Orthogonalization of the Direction Cosine Matrix.  

National Technical Information Service (NTIS)

When the Direction Cosine Matrix (DCM) is used in Strapdown Inertial Navigation or other aerospace systems to describe vehicular attitude, it is computed inaccurately due to the use of fast but imprecise algorithms, and the resulting matrix is often not o...

J. Meyer I. Y. Bar-Itzhack

1976-01-01

268

Computerized Approach for Matrix-Form FMEA  

Microsoft Academic Search

This paper discusses a computerized technique for preparing a matrix-form of failure modes and effects analysis which has previously been completed using manual methods. The basic input to the computer is a definition of each element of the system, applicable failure modes, and the resultant effect of each failure mode. From this input, the computer develops the matrix, locates the

John M. Legg

1978-01-01

269

Metal matrix composites microfracture - Computational simulation  

NASA Technical Reports Server (NTRS)

Fiber/matrix fracture and fiber-matrix interface debonding in a metal matrix composite (MMC) are computationally simulated. These simulations are part of a research activity to develop computational methods for microfracture, microfracture propagation and fracture toughness of the metal matrix composites. The three-dimensional finite element model used in the simulation consists of a group of nine unidirectional fibers in three by three unit cell array of SiC/Ti15 metal matrix composite with a fiber volume ration of 0.35. This computational procedure is used to predict the fracture process and establish the hierarchy of fracture modes based on strain energy release rate. It is also used to predict stress redistribution to surrounding matrix-fibers due to initial and progressive fracture of fiber/matrix and due to debonding of fiber-matrix interface. Microfracture results for various loading cases such as longitudinal, transverse, shear and bending are presented and discussed. Step-by-step procedures are outlined to evaluate composite microfracture for a given composite system.

Mital, S. K.; Caruso, J. J.; Chamis, C. C.

1990-01-01

270

Metal matrix composites microfracture: Computational simulation  

NASA Technical Reports Server (NTRS)

Fiber/matrix fracture and fiber-matrix interface debonding in a metal matrix composite (MMC) are computationally simulated. These simulations are part of a research activity to develop computational methods for microfracture, microfracture propagation and fracture toughness of the metal matrix composites. The three-dimensional finite element model used in the simulation consists of a group of nine unidirectional fibers in three by three unit cell array of SiC/Ti15 metal matrix composite with a fiber volume ration of 0.35. This computational procedure is used to predict the fracture process and establish the hierarchy of fracture modes based on strain energy release rate. It is also used to predict stress redistribution to surrounding matrix-fibers due to initial and progressive fracture of fiber/matrix and due to debonding of fiber-matrix interface. Microfracture results for various loading cases such as longitudinal, transverse, shear and bending are presented and discussed. Step-by-step procedures are outlined to evaluate composite microfracture for a given composite system.

Mital, Subodh K.; Caruso, John J.; Chamis, Christos C.

1990-01-01

271

Polysilicon TFT active matrix organic EL displays  

Microsoft Academic Search

Organic light emitting diodes are a new flat panel display technology that offers high luminescent efficiencies. In this paper, with aspects of this new technology are reviewed and the limitations of the currently used passive matrix addressing are identified. New active matrix addressed organic light emitting diode displays are proposed that are based on the polysilicon TFT technology. Different polysilicon

Miltiadis K. Hatalis; Mark J. Stewart; Ching W. Tang; John Burtis

1997-01-01

272

Renormalization group equations for the CKM matrix  

Microsoft Academic Search

We derive the one loop renormalization group equations for the Cabibbo-Kobayashi-Maskawa (CKM) matrix for the standard model, its two Higgs extension, and the minimal supersymmetric extension in a novel way. The derived equations depend only on a subset of the model parameters of the renormalization group equations for the quark Yukawa couplings so the CKM matrix evolution cannot fully test

P. Kielanowski; S. R. Juarez W; J. H. Montes de Oca Y

2008-01-01

273

Juxtaposed Integration Matrix: A Crisis Communication Tool.  

National Technical Information Service (NTIS)

The purpose of this study was to field test the Juxtaposed Integration Matrix, a crisis communication tool, in real and simulated crisis scenarios by U.S. Air Force public affairs officers. Practitioners at three test locations found the matrix validated ...

J. H. Cunningham

2005-01-01

274

Whisker-Reinforced Ceramic Matrix Composites,  

National Technical Information Service (NTIS)

The role of whisker/matrix interfacial characteristics on the toughening mechanisms in SiC whisker/Al2O3 matrix composites was investigated. Specifically, the surface chemistry of two whisker types (Silar SC-9 and Tateho SCW-1S) was correlated to the frac...

J. Homeny W. L. Vaughn

1986-01-01

275

The composition of carbonaceous chondrite matrix  

NASA Technical Reports Server (NTRS)

Matrix compositions of 32 of the approximately 40 known carbonaceous chondrites were analyzed using an electron probe defocussed-beam technique. Except in those chondrites that show evidence of metamorphism, matrices are compositionally similar and have correlation coefficients of +0.96 or greater. The implications of these analyses for the chemistry of individual matrix phases and for primitive solar system material are discussed.

Mcsween, H. Y., Jr.; Richardson, S. M.

1977-01-01

276

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

277

Optimum interface properties for metal matrix composites  

NASA Technical Reports Server (NTRS)

Due to the thermal expansion coefficient mismatch (CTE) between the fiber and the matrix, high residual sresses exist in metal matrix composite systems upon cool down from processing temperature to room temperature. An interface material can be placed between the fiber and the matrix to reduce the high tensile residual stresses in the matrix. A computer program was written to minimize the residual stress in the matrix subject to the interface material properties. The decision variables are the interface modulus, thickness and thermal expansion coefficient. The properties of the interface material are optimized such that the average distortion energy in the matrix and the interface is minimized. As a result, the only active variable is the thermal expansion coefficient. The optimum modulus of the interface is always the minimum allowable value and the interface thickness is always the maximum allowable value, independent of the fiber/matrix system. The optimum interface thermal expansion coefficient is always between the values of the fiber and the matrix. Using this analysis, a survey of materials was conducted for use as fiber coatings in some specific composite systems.

Ghosn, Louis J.; Lerch, Bradley A.

1989-01-01

278

Weighted LAD based on the hat matrix  

Microsoft Academic Search

Least Absolute deviation (LAD) is very sensitive in the presence of high leverage. The letter is commonly detected by the Hat matrix. This paper aims to propose a new robust method called WLADH. It tries to correct sensibility of LAD estimator. We show that LAD sensitivity is corre- lated with leverage's hat matrix value (hii). Hubert and Rousseeuw (1997) proposed

S. Rekaia

279

Weak matrix elements for CP violation.  

SciTech Connect

We present preliminary results of matrix elements of four fermion operators relevant to the determination of e and E ' / E using staggered fermions. To calculate the matrix elements relevant to CP violation in Kaon decays it is important to use a lattice formulation which preserves (some) chiral symmetry.

Lee, W. (Weonjong); Gupta, R. (Rajan); Christ, N.; Fleming, G. T.; Kilcup, G. (Gregory); Liu, G.; Mawhinney, R. (Robert); Sharpe, S. (Steven); Wu, L.; Bhattacharya, T. (Tanmoy)

2001-01-01

280

Fast matrix multiplies using graphics hardware  

Microsoft Academic Search

We present a technique for large matrix-matrix multiplies using low cost graphics hardware. The result is computed by literally visualizing the computations of a simple parallel processing algorithm. Current graphics hardware technology has limited precision and thus limits immediate applicability of our algorithm. We include results demonstrating proof of concept, correctness, speedup, and a simple application. This is therefore forward

E. Scott Larsen; David K. McAllister

2001-01-01

281

Glueball Matrix Elements on Anisotropic Lattices.  

National Technical Information Service (NTIS)

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 ar...

Y. Chen S. J. Dong T. Draper I. Horvath F. X. Lee N. Mathur

2003-01-01

282

Counseling Uses of the Hill Interaction Matrix.  

ERIC Educational Resources Information Center

While the Hill Interaction Matrix was developed as a research instrument to assess interview process, it is also generally useful in any undertaking requiring the evaluation of verbal interaction and, hence, can be used as an aid in modifying communication in order to increase its therapeutic effect. The Hill Interaction Matrix with accompanying…

Boyd, Robert E.

283

Matrix metalloproteinases and their role in psoriasis.  

PubMed

This review summarizes the contribution of matrix metalloproteinases to the pathogenesis of psoriasis. In psoriasis, matrix metalloproteinases are involved in the structural changes of the epidermis via the modification of intracellular contacts and the composition of the extracellular matrix, promoting angiogenesis in the dermal blood vessels and the infiltration of immune cells. Moreover, some matrix metalloproteinases become differentially expressed during the disease eruption and their expression correlates with the clinical score. A separate section of the review is dedicated to the pharmacological approaches that are used to control matrix metalloproteinases, such as oral metalloproteinase inhibitors, such as azasugars and phosphonamides. The aim of this manuscript is to assess the role of matrix metalloproteinases in the physiological processes that accompany the disease. Moreover, it is especially important to evaluate progress in this field and characterize recently appeared medicines. Because any experimental drugs that target matrix metalloproteinases are involved in active clinical trials, this manuscript also reviews the latest experimental data regarding distribution and expression of matrix metalloproteinases in healthy skin and lesional skin. Therefore, the performed analysis highlights potential problems associated with the use of metalloproteinase inhibitors in clinical studies and suggests simple and easy understandable criteria that future innovative metalloproteinase inhibitors shall satisfy. PMID:24518811

Mezentsev, Alexandre; Nikolaev, Alexander; Bruskin, Sergey

2014-04-25

284

Matrix flow and densification during the consolidation of matrix coated fibres  

Microsoft Academic Search

The consolidation of titanium alloy metal matrix composites from matrix coated fibres has been modelled using a continuum finite element approach. Predictions of time to achieve full density are in good agreement with experimental data. The predicted matrix flow has been compared with metallographic sections from samples containing novel yttria marker layers, to allow measurements of actual flow during densification.

S. Schueler; B. Derby; M. Wood; C. Ward-Close

2000-01-01

285

Computing matrix inversion with optical networks.  

PubMed

With this paper we bring about a discussion on the computing potential of complex optical networks and provide experimental demonstration that an optical fiber network can be used as an analog processor to calculate matrix inversion. A 3x3 matrix is inverted as a proof-of-concept demonstration using a fiber network containing three nodes and operating at telecomm wavelength. For an NxN matrix, the overall solving time (including setting time of the matrix elements and calculation time of inversion) scales as O(N(2)), whereas matrix inversion by most advanced computer algorithms requires ~O(N(2.37)) computational time. For well-conditioned matrices, the error of the inversion performed optically is found to be around 3%, limited by the accuracy of measurement equipment. PMID:24514991

Wu, Kan; Soci, Cesare; Shum, Perry Ping; Zheludev, Nikolay I

2014-01-13

286

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

287

The matrix exponential in transient structural analysis  

NASA Technical Reports Server (NTRS)

The primary usefulness of the presented theory is in the ability to represent the effects of high frequency linear response with accuracy, without requiring very small time steps in the analysis of dynamic response. The matrix exponential contains a series approximation to the dynamic model. However, unlike the usual analysis procedure which truncates the high frequency response, the approximation in the exponential matrix solution is in the time domain. By truncating the series solution to the matrix exponential short, the solution is made inaccurate after a certain time. Yet, up to that time the solution is extremely accurate, including all high frequency effects. By taking finite time increments, the exponential matrix solution can compute the response very accurately. Use of the exponential matrix in structural dynamics is demonstrated by simulating the free vibration response of multi degree of freedom models of cantilever beams.

Minnetyan, Levon

1987-01-01

288

A pathway to matrix-variate gamma and normal densities  

Microsoft Academic Search

A general real matrix-variate probability model is introduced here, which covers almost all real matrix-variate densities used in multivariate statistical analysis. Through the new density introduced here, a pathway is created to go from matrix-variate type-1 beta to matrix-variate type-2 beta to matrix-variate gamma to matrix-variate Gaussian or normal densities. Other densities such as extended matrix-variate Student t, F, Cauchy

A. M. Mathai

2005-01-01

289

Study of ionization process of matrix molecules in matrix-assisted laser desorption ionization  

NASA Astrophysics Data System (ADS)

Proton transfer and adduction reaction of matrix molecules in matrix-assisted laser desorption ionization were studied. By using 2,4,6-trihydroxyacetophenone (THAP), 2,5-dihydroxybenzoic acid (DHBA), and their related compounds in which the position of a hydroxyl group is different, it was clarified that a hydroxyl group forming an intramolecular hydrogen bond is related to the ionization of matrix molecules. Intramolecular proton transfer in the electronic excited state of the matrix and subsequent proton adduction from a surrounding solvent to the charge-separated matrix are the initial steps for the ionization of matrix molecules. Nanosecond pump-probe NIR-UV mass spectrometry confirmed that the existence of analyte molecules having large dipole moment in their structures is necessary for the stabilization of [matrix + H]+ in the electronic ground state.

Murakami, Kazumasa; Sato, Asami; Hashimoto, Kenro; Fujino, Tatsuya

2013-06-01

290

Hierarchical cluster analysis of matrix effects on 110 pesticide residues in 28 tea matrixes.  

PubMed

Matrix effects on 110 pesticides in 28 tea matrixes of different varieties and origins by LC/MS/MS were studied, and most of the pesticides exhibited soft and medium signal suppression. To better understand the influence of the tea varieties and the physicochemical characteristics of pesticides on the matrix effects, the multivariate analysis tool called hierarchical cluster analysis was applied. Tea matrixes were grouped into three clusters: unfermented, fermented, and post-fermented teas. Any type of tea can be chosen from each cluster as a corresponding representative matrix within that cluster to make matrix-matched solutions, which could simplify analysis while guaranteeing its accuracy. Matrix effects on most pesticides were similar despite the physicochemical diversities of the pesticides. PMID:24645529

Li, Yan; Pang, Guo-Fang; Fan, Chun-Lin; Chen, Xi

2013-01-01

291

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

292

Contact guidance induced organization of extracellular matrix.  

PubMed

The scarring response following injury to the central nervous system disrupts the anatomical organization of nervous tissue posing a barrier to the regeneration of axons. In the present study, using materials with nanometer level surface features we examined whether matrix organization could be controlled by engineering meningeal cell asymmetry. Following 5 days in culture, the organization of meningeal cells along with their cytoskeletal elements and extracellular matrix proteins was evaluated. Meningeal cell morphology was markedly affected by nanometer level substrate topography. Cell alignment increased with increasing surface roughness. In addition, linear arrays of extracellular matrix were expressed that appeared related to cellular orientation. When cultured on substrates with topographical features of less than 10 nm neither cells nor their extracellular matrix showed organizational asymmetry. However, as oriented surface roughness increased, cellular and matrix asymmetrical organization became more pronounced reaching a threshold at 345 nm. These results suggest that biomaterial surface topography or other methods of altering the orientation of cells may be used to engineer orientation into the secreted extracellular matrix and as such may be a potential strategy for developing organized cell-derived matrix as a bridging material for nerve repair or other regenerative applications. PMID:15020137

Manwaring, Michael E; Walsh, Jennifer F; Tresco, Patrick A

2004-08-01

293

Linear and nonlinear projective nonnegative matrix factorization.  

PubMed

A variant of nonnegative matrix factorization (NMF) which was proposed earlier is analyzed here. It is called projective nonnegative matrix factorization (PNMF). The new method approximately factorizes a projection matrix, minimizing the reconstruction error, into a positive low-rank matrix and its transpose. The dissimilarity between the original data matrix and its approximation can be measured by the Frobenius matrix norm or the modified Kullback-Leibler divergence. Both measures are minimized by multiplicative update rules, whose convergence is proven for the first time. Enforcing orthonormality to the basic objective is shown to lead to an even more efficient update rule, which is also readily extended to nonlinear cases. The formulation of the PNMF objective is shown to be connected to a variety of existing NMF methods and clustering approaches. In addition, the derivation using Lagrangian multipliers reveals the relation between reconstruction and sparseness. For kernel principal component analysis (PCA) with the binary constraint, useful in graph partitioning problems, the nonlinear kernel PNMF provides a good approximation which outperforms an existing discretization approach. Empirical study on three real-world databases shows that PNMF can achieve the best or close to the best in clustering. The proposed algorithm runs more efficiently than the compared NMF methods, especially for high-dimensional data. Moreover, contrary to the basic NMF, the trained projection matrix can be readily used for newly coming samples and demonstrates good generalization. PMID:20350841

Yang, Zhirong; Oja, Erkki

2010-05-01

294

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

295

A transilient matrix for moist convection  

SciTech Connect

A method is introduced for diagnosing a transilient matrix for moist convection. This transilient matrix quantifies the nonlocal transport of air by convective eddies: for every height z, it gives the distribution of starting heights z{prime} for the eddies that arrive at z. In a cloud-resolving simulation of deep convection, the transilient matrix shows that two-thirds of the subcloud air convecting into the free troposphere originates from within 100 m of the surface. This finding clarifies which initial height to use when calculating convective available potential energy from soundings of the tropical troposphere.

Romps, D.; Kuang, Z.

2011-08-15

296

Polysilicon TFT active matrix organic EL displays  

NASA Astrophysics Data System (ADS)

Organic light emitting diodes are a new flat panel display technology that offers high luminescent efficiencies. In this paper, with aspects of this new technology are reviewed and the limitations of the currently used passive matrix addressing are identified. New active matrix addressed organic light emitting diode displays are proposed that are based on the polysilicon TFT technology. Different polysilicon TFT active matrix pixel structures for OLED applications are described and their advantages and disadvantages are discussed. The characteristics of fabricated polysilicon TFT arrays for driving OLED are presented.

Hatalis, Miltiadis K.; Stewart, Mark J.; Tang, Ching W.; Burtis, John

1997-07-01

297

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

298

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.

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

2013-01-01

299

Extracellular matrix, inflammation, and the angiogenic response  

PubMed Central

Inflammation and angiogenesis are frequently coupled in pathological situations such as atherosclerosis, diabetes, and arthritis. The inflammatory response increases capillary permeability and induces endothelial activation, which, when persistent, results in capillary sprouting. This inflammation-induced angiogenesis and the subsequent remodelling steps are in large part mediated by extracellular matrix (ECM) proteins and proteases. The focal increase in capillary permeability is an early consequence of inflammation, and results in the deposition of a provisional fibrin matrix. Subsequently, ECM turnover by proteases permits an invasive program by specialized endothelial cells whose phenotype can be regulated by inflammatory stimuli. ECM activity also provides specific mechanical forces, exposes cryptic adhesion sites, and releases biologically active fragments (matrikines) and matrix-sequestered growth factors, all of which are critical for vascular morphogenesis. Further matrix remodelling and vascular regression contribute to the resolution of the inflammatory response and facilitate tissue repair.

Arroyo, Alicia G.; Iruela-Arispe, M. Luisa

2010-01-01

300

Integrated optic vector-matrix multiplier  

DOEpatents

A vector-matrix multiplier is disclosed which uses N different wavelengths of light that are modulated with amplitudes representing elements of an N.times.1 vector and combined to form an input wavelength-division multiplexed (WDM) light stream. The input WDM light stream is split into N streamlets from which each wavelength of the light is individually coupled out and modulated for a second time using an input signal representing elements of an M.times.N matrix, and is then coupled into an output waveguide for each streamlet to form an output WDM light stream which is detected to generate a product of the vector and matrix. The vector-matrix multiplier can be formed as an integrated optical circuit using either waveguide amplitude modulators or ring resonator amplitude modulators.

Watts, Michael R. (Albuquerque, NM)

2011-09-27

301

Structural Analysis and Matrix Interpretive System /SAMIS/  

NASA Technical Reports Server (NTRS)

Structural Analysis and Matrix Interpretive System eliminates high-speed digital computer restrictions of lack of generalization and lack of flexibility. Programming concepts of the system are standardization, modularity, and programming for intermediate-size problems.

1967-01-01

302

Nonequilibrium Chemistry Boundary Layer Integral Matrix Procedure.  

National Technical Information Service (NTIS)

The development of an analytic procedure for the calculation of nonequilibrium boundary layer flows over surfaces of arbitrary catalycities is described. An existing equilibrium boundary layer integral matrix code was extended to include nonequilibrium ch...

A. C. Buckingham H. Tong H. L. Morse

1973-01-01

303

On the perturbation of analytic matrix functions  

Microsoft Academic Search

In this paper behaviour of the spectrum of matrix-valued functions depending analytically on two parameters is studied. Generalizations of the Rellich theorem on analytic dependence of the spectrum and complete regular splitting of multiple eigenvalues are established.

R. Hryniv; P. Lancaster

1999-01-01

304

Comix, a New Matrix Element Generator  

SciTech Connect

We present a new tree-level matrix element generator, based on the color dressed Berends-Giele recursive relations. We discuss two new algorithms for phase space integration, dedicated to be used with large multiplicities and color sampling.

Gleisberg, Tanju; /SLAC; Hoche, Stefan; /Durham U., IPPP

2008-09-03

305

H -matrix theory vs. eigenvalue localization  

NASA Astrophysics Data System (ADS)

The eigenvalue localization problem is very closely related to the -matrix theory. The most elegant example of this relation is the equivalence between the Ger?gorin theorem and the theorem about nonsingularity of SDD (strictly diagonally dominant) matrices, which is a starting point for further beautiful results in the book of Varga [19]. Furthermore, the corresponding Ger?gorin-type theorem is equivalent to the statement that each matrix from a particular subclass of -matrices is nonsingular. Finally, the statement that all eigenvalues of a given matrix belong to minimal Ger?gorin set (defined in [19]) is equivalent to the statement that every -matrix is nonsingular. Since minimal Ger?gorin set remained unattainable, a lot of different Ger?gorin-type areas for eigenvalues has been developed recently. Along with them, a lot of new subclasses of -matrices were obtained. A survey of recent results in both areas, as well as their relationships, will be presented in this paper.

Cvetkovic, Ljiljana

2006-07-01

306

Recursive Array Layouts and Fast Matrix Multiplication.  

National Technical Information Service (NTIS)

The performance of both serial and parallel implementations of matrix multiplication is highly sensitive to memory system behavior. False sharing and cache conflicts cause traditional column-major or row-major array layouts to incur high variability in me...

S. Chatterjee A. R. Lebeck P. K. Patnala M. Thottehodi

2005-01-01

307

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

308

Breast Multiple Primary and Histology Rules Matrix  

Cancer.gov

Breast Multiple Primary Rules – Matrix C500 – C509 (Excludes lymphoma and leukemia M9590 – 9989 and Kaposi sarcoma M9140) * Prepare one abstract. Use the histology coding rules to assign the appropriate histology code. ** Prepare two or more abstracts.

309

Evaluation of Stone Matrix Asphalt (SMA).  

National Technical Information Service (NTIS)

Stability of conventional bituminous pavements is compromised and rutting rates are accelerated by continually increasing traffic volumes and heavy truck traffic. Some Matrix Asphalt (SMA) was identified during the 1990 European Asphalt Study Tour (EAST) ...

M. Rademaker

1996-01-01

310

New Armour Materials: Metal Matrix Composites.  

National Technical Information Service (NTIS)

The ballistic properties of metal matrix composites are reviewed and discussed. All the data located treats aluminum-base composites reinforced with silicon carbide, boron carbide or aluminum oxide particles. Most of these materials have not been optimize...

S. J. Savage

1994-01-01

311

Optimal matrix approximants in structural identification  

NASA Technical Reports Server (NTRS)

Problems of model correlation and system identification are central in the design, analysis, and control of large space structures. Of the numerous methods that have been proposed, many are based on finding minimal adjustments to a model matrix sufficient to introduce some desirable quality into that matrix. In this work, several of these methods are reviewed, placed in a modern framework, and linked to other previously known ideas in computational linear algebra and optimization. This new framework provides a point of departure for a number of new methods which are introduced here. Significant among these is a method for stiffness matrix adjustment which preserves the sparsity pattern of an original matrix, requires comparatively modest computational resources, and allows robust handling of noisy modal data. Numerical examples are included to illustrate the methods presented herein.

Beattie, C. A.; Smith, S. W.

1992-01-01

312

Spherical Hybrid Matrix Composite Pressure Vessels.  

National Technical Information Service (NTIS)

An exploratory study on the fabrication and behavior of metal and hybrid (metal-resin) matrix composite pressure vessels is described. Spherical vessels were fabricated from boron or stainless steel filaments in aluminum, aluminum-epoxy and epoxy matrices...

F. P. Gerstle T. R. Guess M. Moss

1975-01-01

313

Recent advances in peroxisomal matrix protein import  

PubMed Central

Peroxisomes are essential organelles responsible for many metabolic reactions, such as the oxidation of very long chain and branched fatty acids, D-amino acids and polyamines, as well as the production and turnover of hydrogen peroxide. They comprise a class of organelles called microbodies, including glycosomes, glyoxysomes and Woronin bodies. Dysfunction of human peroxisomes causes severe and often fatal peroxisome biogenesis disorders (PBDs). Peroxisomal matrix protein import is mediated by receptors that shuttle between the cytosol and peroxisomal matrix using ubiquitination/deubiquitination reactions and ATP hydrolysis for receptor recycling. We focus on the machinery involved in the peroxisomal matrix protein import cycle, highlighting recent advances in peroxisomal matrix protein import, cargo release and receptor recycling/degradation.

Liu, Xueqian; Ma, Changle; Subramani, Suresh

2012-01-01

314

Tribological Behavior of Metal Matrix Composites.  

National Technical Information Service (NTIS)

The wear and friction behavior of continuous graphite-fiber-reinforced metal matrix composites was investigated. Composite materials were tested against 4620 steel at 54 m/sec at room temperature in air without lubricant. The graphite fibers studied inclu...

M. F. Amateau R. F. Flowers E. Eliezer

1979-01-01

315

Photogeneration of heptacene in a polymer matrix.  

PubMed

Heptacene (1) was generated by the photodecarbonylation of 7,16-dihydro-7,16-ethanoheptacene-19,20-dione (2) in a polymer matrix using a UV-LED lamp (395 +/- 25 nm). Compound 1 showed a long wavelength absorption band extending from 600 to 825 nm (lambdamax approximately 760 nm) and was found to be stable up to 4 h in the polymer matrix. However, irradiation of a solution of 2 in toluene produced only oxygen adducts. PMID:16866498

Mondal, Rajib; Shah, Bipin K; Neckers, Douglas C

2006-08-01

316

SALTSTONE MATRIX CHARACTERIZATION AND STADIUM SIMULATION RESULTS  

Microsoft Academic Search

SIMCO Technologies, Inc. was contracted to evaluate the durability of the saltstone matrix material and to measure saltstone transport properties. This information will be used to: (1) Parameterize the STADIUM{reg_sign} service life code, (2) Predict the leach rate (degradation rate) for the saltstone matrix over 10,000 years using the STADIUM{reg_sign} concrete service life code, and (3) Validate the modeled results

Langton

2009-01-01

317

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

318

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

2010-03-16

319

Sparsity: Optimization Framework for Sparse Matrix Kernels  

Microsoft Academic Search

Sparse matrix-vector multiplication is an important computational kernel that performs poorly on most modern processors due to a low compute-to-memory ratio and irregular memory access patterns. Opti- mization is dicult because of the complexity of cache-based memory systems and because performance is highly dependent on the nonzero structure of the matrix. The Sparsity system is designed to address these problems

Im Eun-jin; Katherine A. Yelick; Richard W. Vuduc

2004-01-01

320

Factorization of analytic matrix-valued functions  

Microsoft Academic Search

A new method is proposed for calculating the partial indices and the Wiener-Hopf factorization of analytic matrix-valued functions.\\u000a It has computational advantages with respect to the method proposed by the author earlier. The new method is used to find\\u000a the divisors of an analytic matrix-valued function a(t) that generate the zeros ofdet a (t).

V. M. Adukov

1999-01-01

321

High Thermal Conductivity Metal Matrix Composites  

Microsoft Academic Search

\\u000a Metal matrix composites (MMCs) are composed of a metal matrix and a reinforcement, which confers excellent thermally conductive\\u000a and mechanical performance. High thermal conductivity MMCs have special advantages for particular electronic packaging and\\u000a thermal management applications because of their combination of excellent thermal conductivity, relatively low density, and\\u000a tailorable coefficient of thermal expansion (CTE) to match the CTE of semiconductor

Xingcun Colin Tong

322

Group-theoretic Algorithms for Matrix Multiplication  

Microsoft Academic Search

We further develop the group-theoretic approach to fast matrix multiplication introduced by Cohn and Umans, and for the first time use it to derive algorithms asymptotically faster than the standard algorithm. We describe several families of wreath product groups that achieve matrix multi- plication exponent less than3, the asymptotically fastest of which achieves exponent2:41. We present two conjectures regarding specific

Henry Cohn; Robert D. Kleinberg; Balazs Szegedy; Christopher Umans

2005-01-01

323

Anatomy of high-performance matrix multiplication  

Microsoft Academic Search

We present the basic principles that underlie the high-performance implementation of the matrix-matrix multiplication that is part of the widely used GotoBLAS library. Design decisions are justified by successively refining a model of architectures with multilevel memories. A simple but effective algorithm for executing this operation results. Implementations on a broad selection of architectures are shown to achieve near-peak performance.

Kazushige Goto; Robert A. Van De Geijn

2008-01-01

324

Fibre-Matrix Interaction in Soft Tissue  

NASA Astrophysics Data System (ADS)

Although the mechanical behaviour of soft tissue has been extensively studied, the interaction between the collagen fibres and the ground matrix has not been well understood and is therefore ignored by most constitutive models of soft tissue. In this paper, the human annulus fibrosus is used as an example and the potential fibre-matrix interaction is identified by careful investigation of the experimental results of biaxial and uniaxial testing of the human annulus fibrosus. First, the uniaxial testing result of the HAF along the axial direction is analysed and it is shown that the mechanical behaviour of the ground matrix can be well simulated by the incompressible neo-Hookean model when the collagen fibres are all under contraction. If the collagen fibres are stretched, the response of the ground matrix can still be described by the incompressible neo-Hookean model, but the effective stiffness of the matrix depends on the fibre stretch ratio. This stiffness can be more than 10 times larger than the one obtained with collagen fibres under contraction. This phenomenon can only be explained by the fibre-matrix interaction. Furthermore, we find that the physical interpretation of this interaction includes the inhomogeneity of the soft tissue and the fibre orientation dispersion. The dependence of the tangent stiffness of the matrix on the first invariant of the deformation tensor can also be explained by the fibre orientation dispersion. The significant effect of the fibre-matrix interaction strain energy on mechanical behaviour of the soft tissue is also illustrated by comparing some simulation results.

Guo, Zaoyang

2010-05-01

325

Transfer matrix method for linear multibody system  

Microsoft Academic Search

A new method for linear hybrid multibody system dynamics is proposed in this paper. This method, named as transfer matrix\\u000a method of linear multibody system (MSTMM), expands the advantages of the traditional transfer matrix method (TMM). The concepts\\u000a of augmented eigenvector and equation of motion of linear hybrid multibody system are presented at first to find the orthogonality\\u000a and to

Xiaoting Rui; Guoping Wang; Yuqi Lu; Laifeng Yun

2008-01-01

326

Analysis of Boron Carbide Aluminum Matrix Composites  

Microsoft Academic Search

This study deals with the feasibility of using boron carbide (B4C) as reinforcement for aluminum matrix composites (AMCs) obtained by solid-state processes (powder metallurgy and extrusion). Two different reinforcements were considered: B4C as the object of this study and SiC for direct comparison of results. Aluminum alloy AA6061 was used as matrix in all cases. Comparative analysis between both SiC

L. Gómez; D. Busquets-Mataix; V. Amigó; M. D. Salvador

2009-01-01

327

Email Surveillance Using Nonnegative Matrix Factorization  

Microsoft Academic Search

In this study, we apply a non-negative matrix factorization approach for the extraction and detection of concepts or topics\\u000a from electronic mail messages. For the publicly released Enron electronic mail collection, we encode sparse term-by-message\\u000a matrices and use a low rank non-negative matrix factorization algorithm to preserve natural data non-negativity and avoid\\u000a subtractive basis vector and encoding interactions present in

Michael W. Berry; Murray Browne

2005-01-01

328

Matrix metalloproteinase-7 expression in gastric carcinoma  

Microsoft Academic Search

BACKGROUND\\/AIMS: Matrix metalloproteinase-7 (MMP-7) belongs to the same family as matrix degrading metalloproteinase (MMPs) that may play an important part in cancer cell invasion and metastasis. This study reports on the MMP-7 mRNA expression level both in human gastric carcinomas and the normal gastric mucosa. METHODS: From fresh specimens of 47 surgical pairs of primary gastric carcinomas and corresponding normal

M Honda; M Mori; H Ueo; K Sugimachi; T Akiyoshi

1996-01-01

329

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

330

Codifiable Languages and the Parikh Matrix Mapping  

Microsoft Academic Search

Abstract We introduce a couple of families of codifiable languages and investigate properties of these families as well as interrelationships between dierent,families. Also we develop an algorithm based on the Earley algorithm to compute the values of the inverse of the Parikh matrix mapping,over a codifiable context-free language. Finally, an attributed grammar that computes the values of the Parikh matrix

Adrian Atanasiu; Carlos Martín-vide; Alexandru Mateescu

2001-01-01

331

A novel MEMS LTCC switch matrix  

Microsoft Academic Search

A novel planar 4×4 switch matrix using microelectromechanical system (MEMS) switches and low temperature cofired ceramic (LTCC) substrate is presented for the first time. Together a 9-layer LTCC substrate and 32 MEMS switches are integrated to create a non-blocking 4×4 switch matrix functionality with excellent RF performance up to 7 GHz. An accurate model for predicting the interconnect circuit and

Bahram Yassini; Savio Choi; A. Zybura; Ming Yu; R. E. Mihailovich; J. F. DeNatale

2004-01-01

332

Fuel cell with electrolyte matrix assembly  

DOEpatents

This invention is directed to a fuel cell employing a substantially immobilized electrolyte imbedded therein and having a laminated matrix assembly disposed between the electrodes of the cell for holding and distributing the electrolyte. The matrix assembly comprises a non-conducting fibrous material such as silicon carbide whiskers having a relatively large void-fraction and a layer of material having a relatively small void-fraction.

Kaufman, Arthur (West Orange, NJ); Pudick, Sheldon (Sayreville, NJ); Wang, Chiu L. (Edison, NJ)

1988-01-01

333

Micromechanical Modeling of Woven Metal Matrix Composites  

NASA Technical Reports Server (NTRS)

This report presents the results of an extensive micromechanical modeling effort for woven metal matrix composites. The model is employed to predict the mechanical response of 8-harness (8H) satin weave carbon/copper (C/Cu) composites. Experimental mechanical results for this novel high thermal conductivity material were recently reported by Bednarcyk et al. along with preliminary model results. The micromechanics model developed herein is based on an embedded approach. A micromechanics model for the local (micro-scale) behavior of the woven composite, the original method of cells (Aboudi), is embedded in a global (macro-scale) micromechanics model (the three-dimensional generalized method of cells (GMC-3D) (Aboudi). This approach allows representation of true repeating unit cells for woven metal matrix composites via GMC-3D, and representation of local effects, such as matrix plasticity, yarn porosity, and imperfect fiber-matrix bonding. In addition, the equations of GMC-3D were reformulated to significantly reduce the number of unknown quantities that characterize the deformation fields at the microlevel in order to make possible the analysis of actual microstructures of woven composites. The resulting micromechanical model (WCGMC) provides an intermediate level of geometric representation, versatility, and computational efficiency with respect to previous analytical and numerical models for woven composites, but surpasses all previous modeling work by allowing the mechanical response of a woven metal matrix composite, with an elastoplastic matrix, to be examined for the first time. WCGMC is employed to examine the effects of composite microstructure, porosity, residual stresses, and imperfect fiber-matrix bonding on the predicted mechanical response of 8H satin C/Cu. The previously reported experimental results are summarized, and the model predictions are compared to monotonic and cyclic tensile and shear test data. By considering appropriate levels of porosity, residual stresses, and imperfect fiber-matrix debonding, reasonably good qualitative and quantitative correlation is achieved between model and experiment.

Bednarcyk, Brett A.; Pindera, Marek-Jerzy

1997-01-01

334

4 × 4 optical-gate matrix switch  

Microsoft Academic Search

An optical gate-based matrix switch is proposed and a switching function in a 4 × 4 experimental switch is demonstrated. The experimental switch is composed of fiber-type splitters, a lantham-modified lead zirconate-titanate solid solution (PLZT) optical-gate array, and fiber-type combiners. The switch has a broad bandwidth of 400 Mbit\\/s for nonreturn-to-zero (NRZ) optical signal transmission. A possible maximum matrix size

AKIRA HIMENO; MORIO KOBAYASHI

1985-01-01

335

Guided-wave optical gate matrix switch  

Microsoft Academic Search

An optical gate matrix switch that is made by integrating InGaAsP laser diode gates with high-silica guided-wave splitter and combiner circuits in a hybrid fashion is proposed and demonstrated. It provides point-to-multipoint switching. A preliminary experiment for a 4×4 matrix switch shows that the switch is capable of more than 400-Mb\\/s bandwidth signal switching

Akira Himeno; Hiroshi Terui; Morio Kobayashi

1988-01-01

336

The Extracellular Matrix in Digestive Cancer  

Microsoft Academic Search

The extracellular components of the cancer microenvironment play a critical role in tumor initiation, progression and invasion.\\u000a In this review we examine the normal formation and function of the basement membrane and extracellular matrix. We characterize\\u000a the interactions between the matrix and the epithelium and explore the causes and consequences of the extracellular remodeling\\u000a that accompanies carcinogenesis. Finally, we address

Daniel L. Worthley; Andrew S. Giraud; Timothy C. Wang

2010-01-01

337

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

338

Extracellular matrix material valve conduit and methods of making thereof  

US Patent & Trademark Office Database

Methods for forming extracellular matrix valve conduits are disclosed. Extracellular matrix valve conduits produced using the disclosed methods are also disclosed. Methods of sterilizing and decellularizing extracellular matrix materials are also disclosed.

2014-04-15

339

CUR matrix decompositions for improved data analysis  

PubMed Central

Principal components analysis and, more generally, the Singular Value Decomposition are fundamental data analysis tools that express a data matrix in terms of a sequence of orthogonal or uncorrelated vectors of decreasing importance. Unfortunately, being linear combinations of up to all the data points, these vectors are notoriously difficult to interpret in terms of the data and processes generating the data. In this article, we develop CUR matrix decompositions for improved data analysis. CUR decompositions are low-rank matrix decompositions that are explicitly expressed in terms of a small number of actual columns and/or actual rows of the data matrix. Because they are constructed from actual data elements, CUR decompositions are interpretable by practitioners of the field from which the data are drawn (to the extent that the original data are). We present an algorithm that preferentially chooses columns and rows that exhibit high “statistical leverage” and, thus, in a very precise statistical sense, exert a disproportionately large “influence” on the best low-rank fit of the data matrix. By selecting columns and rows in this manner, we obtain improved relative-error and constant-factor approximation guarantees in worst-case analysis, as opposed to the much coarser additive-error guarantees of prior work. In addition, since the construction involves computing quantities with a natural and widely studied statistical interpretation, we can leverage ideas from diagnostic regression analysis to employ these matrix decompositions for exploratory data analysis.

Mahoney, Michael W.; Drineas, Petros

2009-01-01

340

Sparse estimation of a covariance matrix  

PubMed Central

Summary 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.

Bien, Jacob; Tibshirani, Robert J.

2011-01-01

341

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

342

Temperature dependent nonlinear metal matrix laminae behavior  

NASA Technical Reports Server (NTRS)

An analytical method is described for computing the nonlinear thermal and mechanical response of laminated plates. The material model focuses upon the behavior of metal matrix materials by relating the nonlinear composite response to plasticity effects in the matrix. The foundation of the analysis is the unidirectional material model which is used to compute the instantaneous properties of the lamina based upon the properties of the fibers and matrix. The unidirectional model assumes that the fibers properties are constant with temperature and assumes that the matrix can be modelled as a temperature dependent, bilinear, kinematically hardening material. An incremental approach is used to compute average stresses in the fibers and matrix caused by arbitrary mechanical and thermal loads. The layer model is incorporated in an incremental laminated plate theory to compute the nonlinear response of laminated metal matrix composites of general orientation and stacking sequence. The report includes comparisons of the method with other analytical approaches and compares theoretical calculations with measured experimental material behavior. A section is included which describes the limitations of the material model.

Barrett, D. J.; Buesking, K. W.

1986-01-01

343

The scientific computing (SC) matrix library  

SciTech Connect

The scientific computing matrix library (SCMAT) is a C++ class library for representing and manipulating rectangular, symmetric, and diagonal matrices and vectors. It is founded on an abstract base classes for each of these types of matrices; these are specialized to concrete matrix classes well suited for particular computational environments. The local matrix specializations (MS) do no communication. All elements reside on each node and all computations are duplicated on each node. The replicated MS hold all of the elements on each node, however do some communication in order to reduce computation time. The distributed MS spread the elements across all the nodes and thus require less storage than local matrices however these use more communication than replicated matrices. The blocked MS are used to implement point group symmetry. One of the other MS is used to hold the diagonal subblocks of a matrix. The offdiagonal subblocks are known to be zero and not stored, resulting in considerable savings in storage and computation for those cases where it applies. A variety of supporting classes is also provided. There is a dimension class that optionally contains application specific blocking information as well as the matrix dimension. Classes to assist in iterating through the elements of a matrix are available. Finally, a class is provided which acts as a class factory by returning mutually consistent MS.

Janssen, C.L.; Seidl, E.T.; Nielsen, I.M.B.; Colvin, M.E.

1996-10-01

344

Instructive roles of extracellular matrix on autophagy.  

PubMed

Autophagy plays an essential role in maintaining an intricate balance between nutrient demands and energetic requirements during normal homeostasis. Autophagy recycles metabolic substrates from nonspecific bulk degradation of proteins and excess or damaged organelles. Recent work posits an active and dynamic signaling role for extracellular matrix-evoked autophagic regulation, that is, allosteric and independent of prevailing nutrient conditions. Several candidates, representing a diverse repertoire of matrix constituents (decorin, collagen VI, laminin ?2, endostatin, endorepellin, and kringle V), can modulate autophagic signaling pathways. Importantly, a novel principle indicates that matrix constituents can differentially modulate autophagic induction and repression via interaction with specific receptors. Most of the matrix-derived factors described here appear to control autophagy in a canonical manner but independent of nutrient deprivation. Because the molecular composition and structure of the extracellular matrix are dynamically remodeled during various physiological and pathological conditions, we propose that matrix-regulated autophagy is key for maintaining proper tissue homeostasis and disease prevention, such as cancer progression and muscular dystrophies. PMID:24976620

Neill, Thomas; Schaefer, Liliana; Iozzo, Renato V

2014-08-01

345

General 4–zero texture mass matrix parametrizations  

NASA Astrophysics Data System (ADS)

It is performed the diagonalization of a non–Hermitian four–zero texture Yukawa matrix with a general formalism. This procedure leads to 3 possibilities to parametrize the relation between the fermion masses and the elements of the corresponding Yukawa matrix. Then, the matrices that diagonalize each Yukawa mass matrix are combined in order to obtain 9 different theoretical CKM or PMNS mixing matrices [1]. Through a ?2 analysis, we have constrained the values of the remaining free parameters such as the theoretical mixing matrix matches the latest experimental measurements of the mixing matrices. This analysis was done without assuming any approximations. In the case of the quark sector, it is found that only four different theoretical mixing matrices are compatible with the actual high precision experimental measurement of the CKM matrix elements. For the lepton sector, where the masses of neutrinos are not known, we found that independently of the parametrization that have been chosen, the updated experimental measurements of the mixing angles in the PMNS matrix, imply a mass for the heaviest left–handed neutrino to be ~ 0.05eV.

Barranco, J.; Delepine, D.; Lopez-Lozano, L.

2014-03-01

346

Matrix method for acoustic levitation simulation.  

PubMed

A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort. PMID:21859587

Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C

2011-08-01

347

Electromagnetic interference shielding using continuous carbon-fiber carbon-matrix and polymer-matrix composites  

Microsoft Academic Search

A carbon-matrix composite with continuous carbon-fibers was found to be an excellent electromagnetic interference (EMI) shielding material with shielding effectiveness 124dB, low surface impedance and high reflectivity in the frequency range from 0.3MHz to 1.5GHz. The shielding effectiveness of polymer-matrix composites with continuous carbon-fibers was less and that of polymer-matrix composites with discontinuous fillers was even less. The addition of

Xiangcheng Luo; D. D. L Chung

1999-01-01

348

Inhibition of membrane-type 1 matrix metalloproteinase at cell-matrix adhesions.  

PubMed

Membrane-type 1 matrix metalloproteinase (MT1-MMP) has been implicated in tumor invasion and metastasis. We previously reported that extracellular matrix degradation by MT1-MMP regulates cell migration via modulating sustained integrin-mediated signals. In this study, MT1-MMP-expressing cells were plated onto fibronectin-coated plates and monitored for cell-matrix adhesion formation and fibronectin degradation. The fibronectin was degraded and removed in line with the cell migration track. The migrating cells showed a polarized morphology and were in contact with the edge of fibronectin through the leading edge, in which cell-matrix adhesions are concentrated. Expression of MT1-MMP targeted to cell-matrix adhesions by fusing with the focal adhesion targeting (FAT) domain of focal adhesion kinase (FAK) promoted the initial fibronectin lysis at the cell periphery immediately after adhesion. These results suggest that fibronectin is degraded by MT1-MMP located at cell-matrix adhesions, which are concentrated at the leading edge of the migrating cells. To inhibit MT1-MMP at cell-matrix adhesion, the dominant negative form of MT1-MMP (MT1-Pex) was targeted to the cell-matrix adhesion by fusing with the FAT domain (MT1-Pex-FAT). MT1-Pex-FAT accumulated at cell-matrix adhesions and inhibited fibronectin degradation as well as FAK phosphorylation more effectively than parental MT1-Pex. MT1-Pex-FAT was also shown to suppress the invasion of tumor cells into three-dimensional collagen gel more strongly than MT1-Pex. These results suggest that MT1-MMP-mediated extracellular matrix lysis at cell-matrix adhesions induces the establishment of cell polarity, which facilitates cell-matrix adhesion turnover and subsequent cell migration. This model highlights the role of MT1-MMP at the leading edge of migrating cells. PMID:18089791

Takino, Takahisa; Saeki, Hiromi; Miyamori, Hisashi; Kudo, Tomoya; Sato, Hiroshi

2007-12-15

349

Optical matrix-matrix multiplication method demonstrated by the use of a multifocus hololens  

NASA Technical Reports Server (NTRS)

A method of optical matrix-matrix multiplication is presented. The feasibility of the method is also experimentally demonstrated by the use of a dichromated-gelatin multifocus holographic lens (hololens). With the specific values of matrices chosen, the average percentage error between the theoretical and experimental data of the elements of the output matrix of the multiplication of some specific pairs of 3 x 3 matrices is 0.4 percent, which corresponds to an 8-bit accuracy.

Liu, H. K.; Liang, Y.-Z.

1984-01-01

350

Parallel Sparse Matrix-Matrix Multiplication and Indexing: Implementation and Experiments  

Microsoft Academic Search

Generalized sparse matrix-matrix multiplication (or SpGEMM) is a key primitive for many high performance graph algorithms as well as for some linear solvers, such as algebraic multigrid. Here we show that SpGEMM also yields efficient algorithms for general sparse-matrix indexing in distributed memory, provided that the underlying SpGEMM implementation is sufficiently flexible and scalable. We demonstrate that our parallel SpGEMM

Aydin Buluc; John Gilbert

2011-01-01

351

Optical matrix-matrix multiplication method demonstrated by the use of a multifocus hololens.  

PubMed

A method of optical matrix-matrix multiplication is presented. The feasibility of the method is also experimentally demonstrated by the use of a dichromated-gelatin multifocus holographic lens (hololens). With the specific values of matrices chosen, the average percentage error between the theoretical and experimental data of the elements of the output matrix of the multiplication of some specific pairs of 3 x 3 matrices is 0.4%, which corresponds to an 8-bit accuracy. PMID:19721585

Liang, Y Z; Liu, H K

1984-08-01

352

Method of producing a hybrid matrix fiber composite  

DOEpatents

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

Deteresa, Steven J. (Livermore, CA); Lyon, Richard E. (Absecon, NJ); Groves, Scott E. (Brentwood, CA)

2006-03-28

353

Mechanical behavior of woven ceramic matrix composites  

NASA Astrophysics Data System (ADS)

Woven ceramic matrix composites (CMCs) fabricated by the chemical vapor infiltration (CVI) technique exhibit highly complex microstructures. As a result, the mechanical behavior of these systems may be significantly more complex than their unidirectional counterparts. In this work, a hierarchical micromechanical modeling approach is developed to model the microstructure inherent in woven CVI CMCs. The above approach is used in conjunction with newly developed woven geometry models as needed to predict the in-plane linear elastic response of both stiff-matrix and soft-matrix woven composites. The resulting analytical micro-stress models are then embedded in an iterative scheme aiming at establishing the non-linear response due to stress induced matrix microcracking under uniaxial tension. Initially, fundamental micromechanics models are applied recursively to compute the effective elastic properties of the homogenized fiber bundles and homogenized inter-bundle matrix material. A modified lamination theory, based on simplified assumptions regarding the micro-field distributions, is developed to predict the unit-cell effective in-plane elastic properties. At the same time, three-dimensional finite element models are developed as needed for numerical verification of the results. While the modified lamination theory does offer an efficient and relatively accurate method to predict in-plane effective elastic properties, the unit-cell micro-stress and micro-strain variations were shown to be more complex than that assumed by the modified lamination theory. Subsequently, refined plain weave unit-cell geometry surface functions applicable to both analytical and numerical finite element models and which take into account the characteristics of both polymer and ceramic matrix composites are presented. A semi-analytical model based on the Rayleigh-Ritz method of approximation under the Kirchhoff-Love deformation hypothesis, which is capable of predicting the requisite elastic micro-fields, is employed to solve the uniaxial, biaxial, and simple shear boundary value problems with spatially varying composite laminate stiffnesses associated with the woven unit-cell geometry. Numerical and analytical results for woven CVI CMCs containing discrete large scale inter-tow matrix voids are reported. The results predicted using the semi-analytical approach are found to be in overall good agreement with the 3-D finite element results for low unit-cell aspect ratios. The above linear elastic models are used in conjunction with a continuum stress induced microcracking model in an incremental and iterative scheme to simulate the evolution of local matrix microcracking and unit-cell non-linear load-displacement response under uniaxial tension loading. The results are compared with experimental results presented elsewhere for a brittle matrix system with similar matrix and fiber material.

Kuhn, Jonathan L.

354

Bäcklund transformation of matrix equations and a discrete matrix first Painlevé equation  

NASA Astrophysics Data System (ADS)

We show that the known auto-Bäcklund transformation for the matrix second Painlevé equation can be generalized to a much wider class of equations. This auto-Bäcklund transformation is an involution and so cannot be used on its own to generate an infinite sequence of different solutions, although for particular equations a second auto-Bäcklund transformation allows this to be done. We also give a Bäcklund transformation for this general class of matrix equations. For the matrix second Painlevé equation we also give a coalescence limit, and a construction of special integrals and of a discrete matrix first Painlevé equation.

Gordoa, P. R.; Pickering, A.; Zhu, Z. N.

2013-08-01

355

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

356

Clastic matrix in EH3 chondrites  

NASA Astrophysics Data System (ADS)

Patches of clastic matrix (15 to 730 µm in size) constitute 4.9 vol% of EH3 Yamato (Y-) 691 and 11.7 vol% of EH3 Allan Hills (ALH) 81189. Individual patches in Y-691 consist of 1) ~25 vol% relatively coarse opaque grain fragments and polycrystalline assemblages of kamacite, schreibersite, perryite, troilite (some grains with daubréelite exsolution lamellae), niningerite, oldhamite, and caswellsilverite; 2) ~30 vol% relatively coarse silicate grains including enstatite, albitic plagioclase, silica and diopside; and 3) an inferred fine nebular component (~45 vol%) comprised of submicrometer-size grains. Clastic matrix patches in ALH 81189 contain relatively coarse grains of opaques (~20 vol%; kamacite, schreibersite, perryite and troilite) and silicates (~30 vol%; enstatite, silica and forsterite) as well as an inferred fine nebular component (~50 vol%). The O-isotopic composition of clastic matrix in Y-691 is indistinguishable from that of olivine and pyroxene grains in adjacent chondrules; both sets of objects lie on the terrestrial mass-fractionation line on the standard three-isotope graph. Some patches of fine-grained matrix in Y-691 have distinguishable bulk concentrations of Na and K, inferred to be inherited from the solar nebula. Some patches in ALH 81189 differ in their bulk concentrations of Ca, Cr, Mn, and Ni. The average compositions of matrix material in Y-691 and ALH 81189 are similar but not identical—matrix in ALH 81189 is much richer in Mn (0.23 ± 0.05 versus 0.07 ± 0.02 wt%) and appreciably richer in Ni (0.36 ± 0.10 versus 0.18 ± 0.05 wt%) than matrix in Y-691. Each of the two whole-rocks exhibits a petrofabric, probably produced by shock processes on their parent asteroid.

Rubin, A. E.; Griset, C. D.; Choi, B.-G.; Wasson, J. T.

2009-05-01

357

Shrinkage Estimation of the Realized Relationship Matrix  

PubMed Central

The additive relationship matrix plays an important role in mixed model prediction of breeding values. For genotype matrix X (loci in columns), the product XX? is widely used as a realized relationship matrix, but the scaling of this matrix is ambiguous. Our first objective was to derive a proper scaling such that the mean diagonal element equals 1+f, where f is the inbreeding coefficient of the current population. The result is a formula involving the covariance matrix for sampling genomic loci, which must be estimated with markers. Our second objective was to investigate whether shrinkage estimation of this covariance matrix can improve the accuracy of breeding value (GEBV) predictions with low-density markers. Using an analytical formula for shrinkage intensity that is optimal with respect to mean-squared error, simulations revealed that shrinkage can significantly increase GEBV accuracy in unstructured populations, but only for phenotyped lines; there was no benefit for unphenotyped lines. The accuracy gain from shrinkage increased with heritability, but at high heritability (> 0.6) this benefit was irrelevant because phenotypic accuracy was comparable. These trends were confirmed in a commercial pig population with progeny-test-estimated breeding values. For an anonymous trait where phenotypic accuracy was 0.58, shrinkage increased the average GEBV accuracy from 0.56 to 0.62 (SE < 0.00) when using random sets of 384 markers from a 60K array. We conclude that when moderate-accuracy phenotypes and low-density markers are available for the candidates of genomic selection, shrinkage estimation of the relationship matrix can improve genetic gain.

Endelman, Jeffrey B.; Jannink, Jean-Luc

2012-01-01

358

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

359

METCAN-PC - METAL MATRIX COMPOSITE ANALYZER  

NASA Technical Reports Server (NTRS)

High temperature metal matrix composites offer great potential for use in advanced aerospace structural applications. The realization of this potential however, requires concurrent developments in (1) a technology base for fabricating high temperature metal matrix composite structural components, (2) experimental techniques for measuring their thermal and mechanical characteristics, and (3) computational methods to predict their behavior. METCAN (METal matrix Composite ANalyzer) is a computer program developed to predict this behavior. METCAN can be used to computationally simulate the non-linear behavior of high temperature metal matrix composites (HT-MMC), thus allowing the potential payoff for the specific application to be assessed. It provides a comprehensive analysis of composite thermal and mechanical performance. METCAN treats material nonlinearity at the constituent (fiber, matrix, and interphase) level, where the behavior of each constituent is modeled accounting for time-temperature-stress dependence. The composite properties are synthesized from the constituent instantaneous properties by making use of composite micromechanics and macromechanics. Factors which affect the behavior of the composite properties include the fabrication process variables, the fiber and matrix properties, the bonding between the fiber and matrix and/or the properties of the interphase between the fiber and matrix. The METCAN simulation is performed as point-wise analysis and produces composite properties which are readily incorporated into a finite element code to perform a global structural analysis. After the global structural analysis is performed, METCAN decomposes the composite properties back into the localized response at the various levels of the simulation. At this point the constituent properties are updated and the next iteration in the analysis is initiated. This cyclic procedure is referred to as the integrated approach to metal matrix composite analysis. METCAN-PC is written in FORTRAN 77 for IBM PC series and compatible computers running MS-DOS. An 80286 machine with an 80287 math co-processor is required for execution. The executable requires at least 640K of RAM and DOS 3.1 or higher. The package includes sample executables which were compiled under Microsoft FORTRAN v. 5.1. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskette are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. METCAN-PC was developed in 1992.

Murthy, P. L.

1994-01-01

360

Matrix Metalloproteinase Control of Capillary Morphogenesis  

PubMed Central

Matrix metalloproteinases (MMPs) play crucial roles in a variety of normal (e.g. blood vessel formation, bone development) and pathophysiological (e.g. wound healing, cancer) processes. This is not only due to their ability to degrade the surrounding extracellular matrix (ECM), but also because MMPs function to reveal cryptic matrix binding sites, release matrix-bound growth factors inherent to these processes, and activate a variety of cell surface molecules. The process of blood vessel formation, in particular, is regulated by what is widely classified as the angiogenic switch: a mixture of both pro- and anti-angiogenic factors that function to counteract each other unless the stimuli from one side exceeds the other to disrupt the quiescent state. While it was initially thought that MMPs were strictly pro-angiogenic, new functions for this proteolytic family such as mediating vascular regression and generating matrix fragments with antiangiogenic capacities have been discovered in the last decade. These findings cast MMPs as multi-faceted pro- and anti-angiogenic effectors. The purpose of this review is to introduce the reader to the general structure and characterization of the MMP family and to discuss the temporal and spatial regulation of their gene expression and enzymatic activity in the following crucial steps associated with angiogenesis: degradation of the vascular basement membrane; proliferation and invasion of endothelial cells within the subjacent ECM, organization into immature tubules; maturation of these nascent vessels; and the pruning and regression of the vascular network.

Ghajar, Cyrus M; George, Steven C; Putnam, Andrew J

2010-01-01

361

Nuclear matrix proteins in human colon cancer.  

PubMed Central

The nuclear matrix is the nonchromatin scaffolding of the nucleus. This structure confers nuclear shape, organizes chromatin, and appears to contain important regulatory proteins. Tissue specific nuclear matrix proteins have been found in the rat, mouse, and human. In this study we compared high-resolution two-dimensional gel electropherograms of nuclear matrix protein patterns found in human colon tumors with those from normal colon epithelia. Tumors were obtained from 18 patients undergoing partial colectomy for adenocarcinoma of the colon and compared with tissue from 10 normal colons. We have identified at least six proteins which were present in 18 of 18 colon tumors and 0 of 10 normal tissues, as well as four proteins present in 0 of 18 tumors and in 10 of 10 normal tissues. These data, which corroborate similar findings of cancer-specific nuclear matrix proteins in prostate and breast, suggest that nuclear matrix proteins may serve as important markers for at least some types of cancer. Images

Keesee, S K; Meneghini, M D; Szaro, R P; Wu, Y J

1994-01-01

362

Google matrix analysis of DNA sequences.  

PubMed

For DNA sequences of various species we construct the Google matrix [Formula: see text] 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 [Formula: see text] 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 DNA sequence networks showing their similarities and distinctions with the WWW and linguistic networks. PMID:23671568

Kandiah, Vivek; Shepelyansky, Dima L

2013-01-01

363

Estimating the Inertia Matrix of a Spacecraft  

NASA Technical Reports Server (NTRS)

A paper presents a method of utilizing some flight data, aboard a spacecraft that includes reaction wheels for attitude control, to estimate the inertia matrix of the spacecraft. The required data are digitized samples of (1) the spacecraft attitude in an inertial reference frame as measured, for example, by use of a star tracker and (2) speeds of rotation of the reaction wheels, the moments of inertia of which are deemed to be known. Starting from the classical equations for conservation of angular momentum of a rigid body, the inertia-matrix-estimation problem is formulated as a constrained least-squares minimization problem with explicit bounds on the inertia matrix incorporated as linear matrix inequalities. The explicit bounds reflect physical bounds on the inertia matrix and reduce the volume of data that must be processed to obtain a solution. The resulting minimization problem is a semidefinite optimization problem that can be solved efficiently, with guaranteed convergence to the global optimum, by use of readily available algorithms. In a test case involving a model attitude platform rotating on an air bearing, it is shown that, relative to a prior method, the present method produces better estimates from few data.

Acikmese, Behcet; Keim, Jason; Shields, Joel

2007-01-01

364

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

365

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

366

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

Microsoft Academic Search

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

Thaned Pongjanyakul; Satit Puttipipatkhachorn

2007-01-01

367

Efficient sparse matrix-matrix multiplication on heterogeneous high performance systems  

Microsoft Academic Search

The efficient implementation of sparse matrix-matrix multiplications on high performance parallel machines poses several challenges: large size of input matrices, compressed representation, density of the output matrices, partitioning and load balancing of matrices that present parts with large differences in density and, thus, in computation times. In this paper we show how, starting from the requirements of such application, we

Jakob Siegel; Oreste Villa; Sriram Krishnamoorthy; Antonino Tumeo; Xiaoming Li

2010-01-01

368

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

369

Phase matrix induced symmetrics for multiple scattering using the matrix operator method  

NASA Technical Reports Server (NTRS)

Entirely rigorous proofs of the symmetries induced by the phase matrix into the reflection and transmission operators used in the matrix operator theory are given. Results are obtained for multiple scattering in both homogeneous and inhomogeneous atmospheres. These results will be useful to researchers using the method since large savings in computer time and storage are obtainable.

Hitzfelder, S. J.; Kattawar, G. W.

1973-01-01

370

Exploiting matrix symmetries and physical symmetries in matrix product states and tensor trains  

Microsoft Academic Search

We focus on symmetries related to matrices and vectors appearing in the simulation of quantum many-body systems. Spin Hamiltonians have special matrix-symmetry properties such as persymmetry. Furthermore, the systems may exhibit physical symmetries translating into symmetry properties of the eigenvectors of interest. Both types of symmetry can be exploited in sparse representation formats such as Matrix Product States (MPS) for

Thomas K. Huckle; Konrad Waldherr; Thomas Schulte-Herbrüggen

2012-01-01

371

Cache oblivious storage and access heuristics for blocked matrix-matrix multiplication  

SciTech Connect

The authors investigate effects of ordering in blocked matrix-matrix multiplication. They find that submatrices do not have to be stored contiguously in memory in order to achieve near optimal performance. They also find a good choice of execution order of submatrix operations can lead to a speedup of up to four times for small block sizes.

Bock, Nicolas [Los Alamos National Laboratory; Rubensson, Emanuel H [Los Alamos National Laboratory; Niklasson, Anders M N [Los Alamos National Laboratory; Challacombe, Matt [Los Alamos National Laboratory; Salek, Pawel [SWEDEN

2008-01-01

372

Electrolyte matrix for molten carbonate fuel cells  

DOEpatents

A matrix is described 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 {micro}m to 20 {micro}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. 5 figs.

Huang, C.M.; Yuh, C.Y.

1999-02-09

373

Matrix compression by common subexpression elimination  

NASA Astrophysics Data System (ADS)

In this report a method for common subexpression elimination in matrices is explored. The method is applied to several types of matrices occurring in numerical simulations. In all cases, the cost of a matrix-vector multiplication is reduced by a significant amount. The amount of storage required for the eliminated matrices is also less than that required for the original matrices. When the proposed method is applied to the Fourier transform matrix, the output is equivalent to the fast Fourier transform. For some matrices used in the fast multipole method for dislocation dynamics, the cost of a matrix-vector multiplication is reduced from O(p6) to O(p4.5), where p is the expansion order. Using an expansion order of 5, one can expect a factor of four speedup of the fast multipole part of a dislocation dynamics code.

Oppelstrup, Tomas

2013-08-01

374

Endogenous Matrix-Derived Inhibitors of Angiogenesis  

PubMed Central

Endogenous inhibitors of angiogenesis are proteins or fragments of proteins that are formed in the body, which can inhibit the angiogenic process. These molecules can be found both in the circulation and sequestered in the extracellular matrix (ECM) surrounding cells. Many matrix-derived inhibitors of angiogenesis, such as endostatin, tumstatin, canstatin and arresten, are bioactive fragments of larger ECM molecules. These substances become released upon proteolysis of the ECM and the vascular basement membrane (VBM) by enzymes of the tumor microenvironment. Although the role of matrix-derived angiogenesis inhibitors is well studied in animal models of cancer, their role in human cancers is less established. In this review we discuss the current knowledge about these molecules and their potential use as cancer therapeutics and biomarkers.

Sund, Malin; Nyberg, Pia; Eikesdal, Hans Petter

2010-01-01

375

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

376

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

377

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 uniaxial composites are tested in tension. Failure of both uniaixial 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, F. I.

1987-01-01

378

Nanomechanics of the Cartilage Extracellular Matrix  

PubMed Central

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

2012-01-01

379

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

380

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

381

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.

Elkington, P T G; Friedland, J S

2006-01-01

382

t matrix of metallic wire structures  

NASA Astrophysics Data System (ADS)

To study the electromagnetic resonance and scattering properties of complex structures of which metallic wire structures are constituents within multiple scattering theory, the t matrix of individual structures is needed. We have recently developed a rigorous and numerically efficient equivalent circuit theory in which retardation effects are taken into account for metallic wire structures. Here, we show how the t matrix can be calculated analytically within this theory. We illustrate our method with the example of split ring resonators. The density of states and cross sections for scattering and absorption are calculated, which are shown to be remarkably enhanced at resonant frequencies. The t matrix serves as the basic building block to evaluate the interaction of wire structures within the framework of multiple scattering theory. This will open the door to efficient design and optimization of assembly of wire structures.

Zhan, T. R.; Chui, S. T.

2014-04-01

383

Matrix representation of composite morphological function processing systems  

Microsoft Academic Search

This paper presents an efficient real-time implementation method for grayscale function processing (FP) systems. The proposed method is based on matrix representation of the composites (FP) systems using the basis matrix and the block basis matrix which are extensions of the basis function. We propose a procedure to derive the basis matrix for composite FP systems from any grayscale structuring

Sung-Jea Kol; Aldo Morales; Kyung-Hoon Lee

1993-01-01

384

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

385

Matrix pencil method for inverse synthetic aperture radar imaging  

Microsoft Academic Search

A study of a new high-resolution method called the matrix pencil method for inverse synthetic aperture radar (ISAR) imaging is presented. Simulation comparison of the matrix pencil method and the fast Fourier transform (FFT) method demonstrates the superiority of the matrix pencil method. The matrix pencil method is tested on a real data set and it is found to be

F. A. Baqai; Y. Hua

1992-01-01

386

Matrix Analytic Methods for Stochastic Fluid Flows  

NSDL National Science Digital Library

This presentation, created by V. Ramaswami of AT&T Labs - Shannon Laboratory, addresses the matrix analytic approach to stochastic fluid flows. The author structures the overview in this manner: the Markov modulated fluid flow, review: quasi birth and death processes, matrix-exponential structure for the MMFF, the Markov renewal approach to MMFF and a summary. The resource employs charts, graphs and basic mathematical formula to demonstrate these concepts. While this is a complex topic, the author boils it down to a fairly understandable and concise overview.

Ramaswami V.

2009-03-12

387

Some remarks on unilateral matrix equations  

SciTech Connect

We briefly review the results of our paper LBNL-46775: We study certain solutions of left-unilateral matrix equations. These are algebraic equations where the coefficients and the unknown are square matrices of the same order, or, more abstractly, elements of an associative, but possibly noncommutative algebra, and all coefficients are on the left. Recently such equations have appeared in a discussion of generalized Born-Infeld theories. In particular, two equations, their perturbative solutions and the relation between them are studied, applying a unified approach based on the generalized Bezout theorem for matrix polynomials.

Cerchiai, Bianca L.; Zumino, Bruno

2001-02-01

388

Matrix Perturbation Techniques in Structural Dynamics  

NASA Technical Reports Server (NTRS)

Matrix perturbation are developed techniques which can be used in the dynamical analysis of structures where the range of numerical values in the matrices extreme or where the nature of the damping matrix requires that complex valued eigenvalues and eigenvectors be used. The techniques can be advantageously used in a variety of fields such as earthquake engineering, ocean engineering, aerospace engineering and other fields concerned with the dynamical analysis of large complex structures or systems of second order differential equations. A number of simple examples are included to illustrate the techniques.

Caughey, T. K.

1973-01-01

389

Universality in complex networks: Random matrix analysis  

NASA Astrophysics Data System (ADS)

We apply random matrix theory to complex networks. We show that nearest neighbor spacing distribution of the eigenvalues of the adjacency matrices of various model networks, namely scale-free, small-world, and random networks follow universal Gaussian orthogonal ensemble statistics of random matrix theory. Second, we show an analogy between the onset of small-world behavior, quantified by the structural properties of networks, and the transition from Poisson to Gaussian orthogonal ensemble statistics, quantified by Brody parameter characterizing a spectral property. We also present our analysis for a protein-protein interaction network in budding yeast.

Bandyopadhyay, Jayendra N.; Jalan, Sarika

2007-08-01

390

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

391

Ceramic Matrix Composite (CMC) Materials Development  

NASA Technical Reports Server (NTRS)

Under the former NASA EPM Program, much initial progress was made in identifying constituent materials and processes for SiC/SiC ceramic composite hot-section components. This presentation discusses the performance benefits of these approaches and elaborates on further constituent and property improvements made under NASA UEET. These include specific treatments at NASA that significantly improve the creep and environmental resistance of the Sylramic(TM) Sic fiber as well as the thermal conductivity and creep resistance of the CVI Sic matrix. Also discussed are recent findings concerning the beneficial effects of certain 2D-fabric architectures and carbon between the BN interphase coating and Sic matrix.

DiCarlo, James

2001-01-01

392

On Matrix Representations of Participation Constraints  

NASA Astrophysics Data System (ADS)

We discuss the existence of matrix representations for generalised and minimum participation constraints which are frequently used in database design and conceptual modelling. Matrix representations, also known as Armstrong relations, have been studied in literature e.g. for functional dependencies and play an important role in example-based design and for the implication problem of database constraints. The major tool to achieve the results in this paper is a theorem of Hajnal and Szemerédi on the occurrence of clique graphs in a given graph.

Hartmann, Sven; Leck, Uwe; Link, Sebastian

393

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

PubMed

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 ((3)HHO). 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 (D(m)/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 (D(m)/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(D(m)/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(D(m)/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. PMID:17350718

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

2007-08-15

394

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

395

Matrix Recipes for Hard Thresholding Methods.  

National Technical Information Service (NTIS)

Given a set of possibly corrupted and incomplete linear measurements, we leverage low-dimensional models to best explain the data for provable solution quality in inversion. A non-exhaustive list of examples includes sparse vector and low-rank matrix appr...

A. Kyrillidis V. Cevher

2012-01-01

396

Matrix Growth Model of the Swedish Forest.  

National Technical Information Service (NTIS)

An area forest matrix model was developed and intended for use as a tool for modelling forest yield in an integrated forest sector model. The model was estimated from data from the Swedish National Forest Survey. Log-linear models are used in the estimati...

O. Sallnaes

1990-01-01

397

Document clustering using nonnegative matrix factorization  

Microsoft Academic Search

A methodology for automatically identifying and clustering semantic features or top- ics in a heterogeneous text collection is presented. Textual data is encoded using a low rank nonnegative matrix factorization algorithm to retain natural data nonneg- ativity, thereby eliminating the need to use subtractive basis vector and encoding calculations present in other techniques such as principal component analysis for semantic

Farial Shahnaz; Michael W. Berry; V. Paul Pauca; Robert J. Plemmons

2006-01-01

398

Extracellular matrix metalloproteinase inducer in interstitial pneumonias.  

PubMed

Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycosylated transmembrane protein that induces matrix metalloproteinases (MMPs), is minimally expressed in the normal adult lung. We previously reported that it is up-regulated in murine bleomycin-induced lung injury. In this study, we determined the expression of EMMPRIN and its association with MMP-2, MMP-7, and MMP-9 in interstitial pneumonias (IPs). We performed immunohistochemistry for EMMPRIN and MMPs on lung tissue from 22 subjects with various IPs. We did bronchoalveolar lavage (BAL) on 9 of these subjects and 13 others with IPs to measure the soluble EMMPRIN in BAL fluid. For comparison, immunohistochemistry or BAL was done on 14 subjects without IPs. The staining intensity for each protein was scored from 0 to 3 in various epithelial cell types. Soluble EMMPRIN in BAL fluid was measured by an enzyme-linked immunosorbent assay. Extracellular matrix metalloproteinase inducer was prominent in abnormal epithelial cells. It was more prominent in hyperplastic type II cells, compared with epithelium in alveolar bronchiolization. It was also elevated in BAL fluid from the subjects with IPs. Matrix metalloproteinases were expressed in cells expressing EMMPRIN, although the profile of MMPs varied among the different abnormal epithelial cell types with MMP-2 and MMP-7 in hyperplastic type II cells and MMP-7 and MMP-9 in cells showing squamous metaplasia and cells comprising bronchiolization. These results suggest a role of EMMPRIN in reepithelialization in IPs. PMID:16867869

Odajima, Nao; Betsuyaku, Tomoko; Nasuhara, Yasuyuki; Itoh, Tomoo; Fukuda, Yuh; Senior, Robert M; Nishimura, Masaharu

2006-08-01

399

Quantum discord in matrix product systems  

Microsoft Academic Search

We consider a class of quantum systems with spin-flip symmetry and derive the quantum correlation measured by the quantum discord (QD). As an illustration, we investigate the QD in a three-body interaction model and an XYZ interaction model, whose ground states can be expressed as matrix product states, and the QD is exactly soluble. We show that the QD behaves

Zhao-Yu Sun; Liang Li; Kai-Lun Yao; Gui-Huan Du; Ji-Wei Liu; Bo Luo; Neng Li; Hai-Na Li

2010-01-01

400

ANALYTICAL MATRIX INVERSE CALCULATIONS, APPLYING PREDICTIVE COORDINATION  

Microsoft Academic Search

The research derived analytical relations between the components of a square matrix and it s inverse. The relations have been worked out, applying a hierarchical approach and non-iterative concept of coordination. The analytical relations have been assessed by computational performance. It has been proved that for large-scale matrices, these relations are computationaly efficient. Copyright © 2004 IFAC

T. Stoilov; K. Stoilova

2004-01-01

401

Interaction matrix element fluctuations in quantum dots  

SciTech Connect

In the Coulomb blockade regime of a ballistic quantum dot, the distribution of conductance peak spacings is well known to be incorrectly predicted by a single-particle picture; instead, matrix element fluctuations of the residual electronic interaction need to be taken into account. In the normalized random-wave model, valid in the semiclassical limit where the number of electrons in the dot becomes large, we obtain analytic expressions for the fluctuations of two-body and one-body matrix elements. However, these fluctuations may be too small to explain low-temperature experimental data. We have examined matrix element fluctuations in realistic chaotic geometries, and shown that at energies of experimental interest these fluctuations generically exceed by a factor of about 3-4 the predictions of the random wave model. Even larger fluctuations occur in geometries with a mixed chaotic-regular phase space. These results may allow for much better agreement between the Hartree-Fock picture and experiment. Among other findings, we show that the distribution of interaction matrix elements is strongly non-Gaussian in the parameter range of experimental interest, even in the random wave model. We also find that the enhanced fluctuations in realistic geometries cannot be computed using a leading-order semiclassical approach, but may be understood in terms of short-time dynamics.

Kaplan, L. [Department of Physics, Tulane University, New Orleans, LA 70118 (United States); Alhassid, Y. [Center for Theoretical Physics, Sloane Physics Laboratory Yale University, New Haven, CT 06520 (United States)

2008-04-04

402

Density-matrix quantum Monte Carlo method  

NASA Astrophysics Data System (ADS)

We present a quantum Monte Carlo method capable of sampling the full density matrix of a many-particle system at finite temperature. This allows arbitrary reduced density matrix elements and expectation values of complicated nonlocal observables to be evaluated easily. The method resembles full configuration interaction quantum Monte Carlo but works in the space of many-particle operators instead of the space of many-particle wave functions. One simulation provides the density matrix at all temperatures simultaneously, from T =? to T =0, allowing the temperature dependence of expectation values to be studied. The direct sampling of the density matrix also allows the calculation of some previously inaccessible entanglement measures. We explain the theory underlying the method, describe the algorithm, and introduce an importance-sampling procedure to improve the stochastic efficiency. To demonstrate the potential of our approach, the energy and staggered magnetization of the isotropic antiferromagnetic Heisenberg model on small lattices, the concurrence of one-dimensional spin rings, and the Renyi S2 entanglement entropy of various sublattices of the 6×6 Heisenberg model are calculated. The nature of the sign problem in the method is also investigated.

Blunt, N. S.; Rogers, T. W.; Spencer, J. S.; Foulkes, W. M. C.

2014-06-01

403

Boron reclamation from neoprene matrix. Final report  

SciTech Connect

A process to recover enriched boron crystalline powder from a neoprene matrix was developed on a laboratory basis and was adapted for use in a reclamation facility. The process includes pyrolysis to break down the polymer, acid leaching to purify the powder, and dry sieving to adjust the particle size distribution of the powder. An estimated 98% of the powder is recovered.

Asper, G.R.

1982-12-01

404

Some Matrix Occupancy Problems with Dichotomous Entries.  

National Technical Information Service (NTIS)

An R X N matrix is generated in the following way. In each row a predetermined number of positions are randomly assigned the value 1; the remaining positions are assigned the value 0. For each column a real valued function of the elements is given. In thi...

L. Holst

1976-01-01

405

Multisensor data fusion for OD matrix estimation  

Microsoft Academic Search

Knowledge of traffic demand at a junction is crucial for most transport systems. Generally, it is represented by an origin-destination (OD) matrix, where each element is a volume of vehicle flow between one of the OD pair of zones of a junction . This paper introduces a new method for a short-time estimation of OD matrices at a signalised junction

Krystyna Biletska; Marie-Hélène Masson; Sophie Midenet; Thierry Denoeux

2009-01-01

406

Fast Matrix Multiplication Algorithms on Mimd Architectures  

Microsoft Academic Search

Sequential fast matrix multiplication algorithms of Strassen and Winograd are stud- ied; the complexity bound given by Strassen is improved. These algorithms are parallelized on MIMD distributed memory architectures of ring and torus topologies; a generalization to a hyper-torus is also given. Complexity and eciency are analyzed and good asymptotic behaviour is proved. These new parallel algorithms are compared with

B. Dumitrescu; J. L. Roch; Denis Trystram

1994-01-01

407

Fast Matrix Multiplication without APA-Algorithms.  

National Technical Information Service (NTIS)

The method of trilinear aggregating with implicit canceling for the design of fast matrix multiplication (MM) algorithms is revised and is formally presented with the use of Generating Tables and of linear transformations of the problem of MM. It is shown...

V. Pan

1981-01-01

408

On Reducing TLB Misses in Matrix Multiplication  

Microsoft Academic Search

During the last decade, a number of projects have pursued the high-performance implementationof matrix multiplication. Typically, these projects organize the computation around an\\\\inner kernel," C = AB +C, that keeps one of the operands in the L1 cache, while streamingparts of the other operands through that cache. Variants include approaches that extend thisprinciple to multiple levels of cache or that

Kazushige Goto; Robert Van De Geijn

2002-01-01

409

Matrix Methods for Multiple-Scattering Problems  

Microsoft Academic Search

If the radiation field is approximated by a discrete distribution at points or latitude circles on the unit sphere, matrix relationships can be written between incident and reflected or transmitted radiation fields. The reflection and transmission matrices thus defined are shown to satisfy algebraic equations which can be used to compute the properties of thick layers by building up the

S. Twomey; H. Jacobowitz; H. B. Howell

1966-01-01

410

On the complexity of polynomial matrix computations  

Microsoft Academic Search

We study the link between the complexity of polynomial matrix multiplication and the complexity of solving other basic linear algebra problems on polynomial matrices. By polynomial matrices we mean ntimes n matrices in K[x] of degree bounded by d, with K a commutative field. Under the straight-line program model we show that multiplication is reducible to the problem of computing

Pascal Giorgi; Claude-Pierre Jeannerod; Gilles Villard

2003-01-01

411

On the asymptotic complexity of matrix multiplication  

Microsoft Academic Search

The main results of this paper have the following flavor: given one algorithm for multiplying matrices, there exists another, better, algorithm. A consequence of these results is that ?, the exponent for matrix multiplication, is a limit point, that is, cannot be realized by any single algorithm. We also use these results to construct a new algorithm which shows that

D. Coppersmith; S. Winograd

1981-01-01

412

Comparison of scalable parallel matrix multiplication libraries  

Microsoft Academic Search

This paper compares two general library routines for performing parallel distributed matrix multiplication. The PUMMA algorithm utilities block scattered data layout, whereas BiMMeR utilizes virtual 2-D torus wrap. The algorithmic differences resulting from these different layouts are discussed us well as the general issues associated with different data layouts for library routines. Results on the Intel Delta for the two

Steven Huss-Lederman; Elaine M. Jacobson; Anna Tsao

1993-01-01

413

Critical state of sand matrix soils.  

PubMed

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

414

Derive Workshop Matrix Algebra and Linear Algebra.  

ERIC Educational Resources Information Center

This document presents the course content for a workshop that integrates the use of the computer algebra system Derive with topics in matrix and linear algebra. The first section is a guide to using Derive that provides information on how to write algebraic expressions, make graphs, save files, edit, define functions, differentiate expressions,…

Townsley Kulich, Lisa; Victor, Barbara

415

Contact guidance induced organization of extracellular matrix  

Microsoft Academic Search

The scarring response following injury to the central nervous system disrupts the anatomical organization of nervous tissue posing a barrier to the regeneration of axons. In the present study, using materials with nanometer level surface features we examined whether matrix organization could be controlled by engineering meningeal cell asymmetry. Following 5 days in culture, the organization of meningeal cells along

Michael E. Manwaring; Jennifer F. Walsh; Patrick A. Tresco

2004-01-01

416

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

417

Noncommutative gauge theories in matrix theory  

Microsoft Academic Search

We present a general framework for matrix theory compactified on a quotient space Rn\\/Gamma, with Gamma a discrete group of Euclidean motions in Rn. The general solution to the quotient conditions gives a gauge theory on a noncommutative space. We characterize the resulting noncommutative gauge theory in terms of the twisted group algebra of Gamma associated with a projective regular

Pei-Ming Ho; Yong-Shi Wu

1998-01-01

418

Revised planning matrix of quality function deployment  

Microsoft Academic Search

Quality function deployment (QFD) has been adopted to improve product quality and development in many fields. Numerous studies have demonstrated that attribute importance and attribute performance have a causal relationship and the customer self-stated raw importance is not the actual importance of a customer attribute. These findings generate questions regarding the applicability of the conventional planning matrix (PM) of QFD.

Wei-Jaw Deng; Ying-Feng Kuo

2008-01-01

419

Automatic Lag Selection in Covariance Matrix Estimation  

Microsoft Academic Search

The authors propose a nonparametric method for automatically selecting the number of autocovariances to use in computing a heteroskedasticity and autocorrelation consistent covariance matrix. For a given kernel for weighting the autocovariances, they prove that their procedure is asymptotically equivalent to one that is optimal under a mean-squared error loss function. Monte Carlo simulations suggest that the authors' procedure performs

Whitney K Newey; Kenneth D West

1994-01-01

420

Algorithms for Sparse Matrix Eigenvalue Problems.  

National Technical Information Service (NTIS)

Eigenvalue problems for an n by n matrix A where n is large and A is sparse are considered. A is assumed to be unstructured: it cannot be reordered to have narrow bandwidth, nor can linear systems of the form Ax = b be solved by special techniques. The ei...

J. G. Lewis

1977-01-01

421

Light weight polymer matrix composite material  

NASA Technical Reports Server (NTRS)

A graphite fiber reinforced polymer matrix is layed up, cured, and thermally aged at about 750 F in the presence of an inert gas. The heat treatment improves the structural integrity and alters the electrical conductivity of the materials. In the preferred embodiment PMR-15 polyimides and Celion-6000 graphite fibers are used.

Bowles, Kenneth J. (inventor); Lowell, Carl E. (inventor)

1988-01-01

422

Light weight polymer matrix composite material  

NASA Technical Reports Server (NTRS)

A graphite fiber reinforced polymer matrix is layed up, cured, and thermally aged at about 750.degree. F. in the presence of an inert gas. The heat treatment improves the structural integrity and alters the electrical conductivity of the materials. In the preferred embodiment PMR-15 polyimides and Celion-6000 graphite fibers are used.

Bowles, Kenneth J. (Inventor); Lowell, Carl E. (Inventor)

1991-01-01

423

All-organic active matrix flexible display  

Microsoft Academic Search

We have fabricated pentacene organic thin-film transistor (OTFT) driven active matrix organic light-emitting diode (OLED) displays on flexible polyethylene terephthalete substrates. These displays have 48×48 bottom-emission OLED pixels with two pentacene OTFTs used per pixel. Parylene is used to isolate the OTFTs and OLEDs with good OTFT yield and uniformity.

Lisong Zhou; Alfred Wanga; Sheng-Chu Wu; Jie Sun; Thomas N. Jackson

2006-01-01

424

The algebras of large N matrix mechanics  

SciTech Connect

Extending early work, we formulate the large N matrix mechanics of general bosonic, fermionic and supersymmetric matrix models, including Matrix theory: The Hamiltonian framework of large N matrix mechanics provides a natural setting in which to study the algebras of the large N limit, including (reduced) Lie algebras, (reduced) supersymmetry algebras and free algebras. We find in particular a broad array of new free algebras which we call symmetric Cuntz algebras, interacting symmetric Cuntz algebras, symmetric Bose/Fermi/Cuntz algebras and symmetric Cuntz superalgebras, and we discuss the role of these algebras in solving the large N theory. Most important, the interacting Cuntz algebras are associated to a set of new (hidden!) local quantities which are generically conserved only at large N. A number of other new large N phenomena are also observed, including the intrinsic nonlocality of the (reduced) trace class operators of the theory and a closely related large N field identification phenomenon which is associated to another set (this time nonlocal) of new conserved quantities at large N.

Halpern, M.B.; Schwartz, C.

1999-09-16

425

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.

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

2014-01-01

426

Estimating injury severity using the Barell matrix  

PubMed Central

Objective To determine whether the Barell matrix (Inj Prev 2002;8:91–6) could effectively categorize injuries by severity. Methods Injury diagnoses of cases in the 2002 US Nationwide Inpatient Sample were classified according to the Barell matrix. For each cell of the matrix, the authors used ICDMAP?90 to determine the predominant Abbreviated Injury Score (AIS) and body region, and calculated the weighted proportion surviving (bPScell) among patients with any diagnosis in that cell. These findings were used to estimate maximum AIS (bAISmax), ISS (bISS), and the minimum or product of bPScell (bPSmin, bPSprod) for injured patients in the 1996–2000 US National Hospital Discharge Surveys. Case survival was determined for different scores, and outcome models using age, sex, comorbidity, mechanism, and bISS or bPSmin were compared to models using ISS calculated from ICDMAP?90 (mISS) or using ICISS. Results Case survival decreased with increasing bAISmax or bISS; survival was closely approximated by bPSmin, and also increased monotonically with bPSprod. Outcome models using bISS or bPSmin were similar to those using mISS or ICISS. An Abbreviated Barell Categorization, with only four groups, was also effective. Conclusion Barell matrix categorization of administrative data allows severity scoring similar to that obtainable with ICDMAP?90 or ICISS.

Clark, D E; Ahmad, S

2006-01-01

427

TAUBERIAN THEOREMS FOR MATRIX REGULAR VARIATION  

PubMed Central

Karamata’s Tauberian theorem relates the asymptotics of a nondecreasing right-continuous function to that of its Laplace-Stieltjes transform, using regular variation. This paper establishes the analogous Tauberian theorem for matrix-valued functions. Some applications to time series analysis are indicated.

MEERSCHAERT, M. M.; SCHEFFLER, H.-P.

2013-01-01

428

Matrix metalloproteinases in tumor invasion and metastasis  

Microsoft Academic Search

Extensive work on the mechanisms of tumor invasion and metastasis has identified matrix metalloproteinases (MMPs) as key players in the events that underlie tumor dissemination. Studies using natural and synthetic MMP inhibitors, as well as tumor cells transfected with cDNAs encoding the MMPs characterized thus far have provided compelling evidence that MMP activity can induce or enhance tumor survival, invasion

Ivan Stamenkovic

2000-01-01

429

RCS prediction from scattering matrix measurements  

Microsoft Academic Search

The radar cross-section measurement equipment described in this paper was designed as a research tool for use in radar discrimination studies. Measurements of the radar scattering matrix made for various bodies were then used to predict the radar cross section of the body for any arbitrary polarization. All measurements were made at X-band with both metal and dielectric covered models

J. A. Webb

1965-01-01

430

The extracellular matrix during heart development  

Microsoft Academic Search

The embryonic extracellular matrix, which is comprised of glycosaminoglycans, glycoproteins, collagens, and proteoglycans, is believed to play multiple roles during heart morphogenesis. Some of these ECM components appear throughout development, however, certain molecules exhibit an interesting transient spatial and temporal distribution. Due to significant new data that have been gathered predominantly in the past 10 years, a comprehensive review of

C. D. Little; B. J. Rongish

1995-01-01

431

Unitary Matrix Models and PAINLEVÉ III  

Microsoft Academic Search

We discussed the full unitary matrix models from the viewpoints of integrable equations and string equations. Coupling the Toda equations and the string equations, we derive a special case of the Painlevé III equation. From the Virasoro constraints, we can use the radial coordinate. The relation between t1 and t-1 is like the complex conjugate.

Masato Hisakado

1996-01-01

432

Factor Analysis of the Image Correlation Matrix.  

ERIC Educational Resources Information Center

Whether to factor the image correlation matrix or to use a new model with an alpha factor analysis of it is mentioned, with particular reference to the determinacy problem. It is pointed out that the distribution of the images is sensibly multivariate normal, making for "better" factor analyses. (Author/CTM)

Kaiser, Henry F.; Cerny, Barbara A.

1979-01-01

433

Random matrix theories and chaotic dynamics.  

National Technical Information Service (NTIS)

A review of some of the main ideas, assumptions and results of the Wigner-Dyson type random matrix theories (RMT) which are relevant in the general context of 'Chaos and Quantum Physics' is presented. RMT are providing interesting and unexpected clues to ...

O. Bohigas

1991-01-01

434

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

435

Extracellular matrix in the trabecular meshwork  

Microsoft Academic Search

The extracellular matrix (ECM) of the trabecular meshwork (TM) is thought to be important in regulating intraocular pressure (IOP) in both normal and glaucomatous eyes. IOP is regulated primarily by a fluid resistance to aqueous humor outflow. However, neither the exact site nor the identity of the normal resistance to aqueous humor outflow has been established. Whether the site and

Ted S. Acott; Mary J. Kelley

2008-01-01

436

Computer program performs stiffness matrix structural analysis  

NASA Technical Reports Server (NTRS)

Computer program generates the stiffness matrix for a particular type of structure from geometrical data, and performs static and normal mode analyses. It requires the structure to be modeled as a stable framework of uniform, weightless members, and joints at which loads are applied and weights are lumped.

Bamford, R.; Batchelder, R.; Schmele, L.; Wada, B. K.

1968-01-01

437

Research on Graphite Reinforced Glass Matrix Composites.  

National Technical Information Service (NTIS)

This report contains the results obtained in the first twelve months of research under NASA Langley Contract NASl-l4346 for the origination of graphite-fiber reinforced glass matrix composites. Included in the report is a summary of the research by other ...

J. F. Bacon K. M. Prewo

1977-01-01

438

Matching Is as Easy as Matrix Inversion  

Microsoft Academic Search

A new algorithm for finding a maximum matching in a general graph is presented; its special feature being that the only computa- tionally non-trivial step required in its execu- tion is the inversion of a single integer matrix. Since this step can be parallelized, we get a simple parallel (RNC2) algorithm. At the heart of our algorithm lies a proba-

Ketan Mulmuley; Umesh V. Vazirani; Vijay V. Vazirani

1987-01-01

439

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

440

Computing integrals involving the matrix exponential  

Microsoft Academic Search

A new algorithm for computing integrals involving the matrix exponential is given. The method employs diagonal Padé approximation with scaling and squaring. Rigorous truncation error bounds are given and incorporated in a Fortran subroutine. The computational aspects of this program are discussed and compared with existing techniques.

C. Van Loan

1978-01-01

441

Research on Graphite Reinforced Glass Matrix Composites.  

National Technical Information Service (NTIS)

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 ox...

K. M. Prewo E. R. Thompson

1980-01-01

442

High Temperature Behavior of Metal Matrix Composites.  

National Technical Information Service (NTIS)

When a metal matrix composite(MMC) is subjected to combined creep and thermal cycling loading, dimensional change is known to occur. This project is aimed at elucidating the mechanisms of a MMC subjected to creep/thermal cycling both experimentally and th...

M. Taya J. K. Lee M. L. Dunn G. Walker T. Mori

1996-01-01

443

An optical matrix-vector multiplier project  

Microsoft Academic Search

The implementation of an optical matrix vector multiplier (OMVM) as a project to demonstrate to undergraduates the parallel capabilities of computing with light, the advantages and disadvantages of analog computers, and noise considerations for accurate results is discussed. The OMVM is designed using waveguides and is interfaced to an Apple IIGS. Software and hardware designs are explained in detail. The

A. P. Ittycheriah; J. F. Walkup; T. F. Krile

1991-01-01

444

Matrix method for integrating-sphere calculations  

Microsoft Academic Search

A simple matrix technique is presented for modeling integrating-sphere performance. The method is applicable to any sphere configuration, including those with flat areas, specular samples, and baffles, and is especially effective when used in computer simulations of sphere irradiance. The formalism can accommodate the angular sensitivity of any detector or the bidirectional-reflectance distribution function of any sample. Examples of simple

Herbert L. Tardy

1991-01-01

445

Silicon carbide yarn reinforced glass matrix composites  

Microsoft Academic Search

Continuous silicon carbide fibre yarn has been used as a reinforcement for borosilicate and 96% silica glass matrices. The resultant composites exhibit excellent levels of strength and elastic modulus up to temperatures of 600‡ C and 1100‡ C, respectively. At higher temperatures excessive matrix softening causes a significant reduction in composite flexural strength.

K. M. Prewo; J. J. Brennan

1982-01-01

446

Rolling consolidation of metal matrix composites  

Microsoft Academic Search

Transverse rolling of metal matrix composite precursor wires is proposed as a consolidation technique for making sheets. Rolling in the transverse direction to the fiber orientation is analytically shown to be feasible, and longitudinal rolling results in fiber breakage. Plasticity analysis is conducted using Hill's general yield criterion for an isotropic materials and the associated Levy-Miles equations modified for plane

K. H. Im; C. K. H. Dharan

1997-01-01

447

Development of Fiber Reinforced Ceramic Matrix Composites.  

National Technical Information Service (NTIS)

Hot-pressed silicon nitride (Si3N4) is a leading candidate for use in advanced gas turbine engines. Using an improved matrix material of Si3N4 + 10 wt % Y2O3, Ta reinforced Si3N4 composites have shown excellent thermal fatigue and thermal shock properties...

J. J. Brennan

1975-01-01

448

A Matrix Model of the Small Group.  

ERIC Educational Resources Information Center

Discusses the development and description of a comprehensive framework to explain small group behavior labeled the Matrix Model. Argues that a synthesis of knowledge from the adaptive, developmental, structural, transactional, and gestalt points of view will provide a more meaningful and useful understanding of small groups. (LLL)

Boyd, Robert D.

1983-01-01

449

A compound matrix algorithm for the computation of the Smith form of a polynomial matrix  

NASA Astrophysics Data System (ADS)

In the present paper is presented a numerical method for the exact reduction of a singlevariable polynomial matrix to its Smith form without finding roots and without applying unimodular transformations. Using the notion of compound matrices, the Smith canonical form of a polynomial matrixM(s)inRnxn[s] is calculated directly from its definition, requiring only the construction of all thep-compound matricesCp(M(s)) ofM(s), 1p?nE This technique produces a stable and accurate numerical algorithm working satisfactorily for any polynomial matrix of any degree.

Mitrouli, M.; Kalogeropoulos, G.

1994-09-01

450

Determination of Matrix Diffusion Properties of Granite  

SciTech Connect

Rock-core column experiments were introduced to estimate the diffusion and sorption properties of Kuru Grey granite used in block-scale experiments. The objective was to examine the processes causing retention in solute transport through rock fractures, especially matrix diffusion. The objective was also to estimate the importance of retention processes during transport in different scales and flow conditions. Rock-core columns were constructed from cores drilled into the fracture and were placed inside tubes to form flow channels in the 0.5 mm gap between the cores and the tube walls. Tracer experiments were performed using uranin, HTO, {sup 36}Cl, {sup 131}I, {sup 22}Na and {sup 85}Sr at flow rates of 1-50 {mu}L.min{sup -1}. Rock matrix was characterized using {sup 14}C-PMMA method, scanning electron microscopy (SEM), energy dispersive X-ray micro analysis (EDX) and the B.E.T. method. Solute mass flux through a column was modelled by applying the assumption of a linear velocity profile and molecular diffusion. Coupling of the advection and diffusion processes was based on the model of generalised Taylor dispersion in the linear velocity profile. Experiments could be modelled applying a consistent parameterization and transport processes. The results provide evidence that it is possible to investigate matrix diffusion at the laboratory scale. The effects of matrix diffusion were demonstrated on the slightly-sorbing tracer breakthrough curves. Based on scoping calculations matrix diffusion begins to be clearly observable for non-sorbing tracer when the flow rate is 0.1 {mu}L.min{sup -1}. The experimental results presented here cannot be transferred directly to the spatial and temporal scales that prevail in an underground repository. However, the knowledge and understanding of transport and retention processes gained from this study is transferable to different scales from laboratory to in-situ conditions. (authors)

Holtta, Pirkko; Siitari-Kauppi, Marja; Huittinen, Nina [Laboratory of Radiochemistry, P.O. Box 55, University of Helsinki, FI-00014 (Finland); Poteri, Antti [VTT Processes, P.O. Box 1608, VTT, FI-02044 (Finland)

2007-07-01

451

Probabilistic Modeling of Ceramic Matrix Composite Strength  

NASA Technical Reports Server (NTRS)

Uncertainties associated with the primitive random variables such as manufacturing process (processing temperature, fiber volume ratio, void volume ratio), constituent properties (fiber, matrix and interface), and geometric parameters (ply thickness, interphase thickness) have been simulated to quantify the scatter in the first matrix cracking strength (FMCS) and the ultimate tensile strength of SCS-6/RBSN (SiC fiber (SCS-6) reinforced reaction-bonded silicon nitride composite) ceramic matrix composite laminate at room temperature. Cumulative probability distribution function for the FMCS and ultimate tensile strength at room temperature (RT) of (0)(sub 8), (0(sub 2)/90(sub 2), and (+/-45(sub 2))(sub S) laminates have been simulated and the sensitivity of primitive variables to the respective strengths have been quantified. Computationally predicted scatter of the strengths for a uniaxial laminate have been compared with those from limited experimental data. Also the experimental procedure used in the tests has been described briefly. Results show a very good agreement between the computational simulation and the experimental data. Dominating failure modes in (0)(sub 8), (0/90)(sub s) and (+/-45)(sub S) laminates have been identified. Results indicate that the first matrix cracking strength for the (0)(sub S), and (0/90)(sub S) laminates is sensitive to the thermal properties, modulus and strengths of both the fiber and matrix whereas the ultimate tensile strength is sensitive to the fiber strength and the fiber volume ratio. In the case of a (+/-45)(sub S), laminate, both the FMCS and the ultimate tensile strengths have a small scatter range and are sensitive to the fiber tensile strength as well as the fiber volume ratio.

Shan, Ashwin R.; Murthy, Pappu L. N.; Mital, Subodh K.; Bhatt, Ramakrishna T.

1998-01-01

452

Helical inclusion in an elastic matrix  

NASA Astrophysics Data System (ADS)

An elastic space containing an elastic helical rod subjected to both axial and radial extension as well as torsion is considered. Due to translation-rotation helical symmetry, the resulting elastic fields in the matrix can be expressed in terms of a two-dimensional helix-associated coordinate system. In this problem, a 'helical elastic foundation' as a generalization of the Winkler foundation is determined by means of which the interacting force and moment at the rod/matrix interface can be expressed in terms of the rod displacement. The matrix is assumed to be linear elastic while the geometric nonlinearity of the helical rod is taken into account. Using superposition of fundamental solutions for a homogeneous elastic space (in the absence of the rod), and the constitutive and equilibrium equations for the rod, the internal forces and moments in the rod as well as the displacement and elastic fields in the matrix are obtained. Along with the general results, two asymptotic solutions are presented. The first, corresponding to a small curvature but not too small pitch, allows an analytical integration of the rod-matrix interaction over the rod cross-section boundary. The second corresponds to an almost straight helical rod: the helix becomes a straight line, but in the limit the main normal to its axis describes a screw surface as in the case of a 'genuine' helix. In this case, the helical elastic foundation has a closed-form parametric expression which is valid for a rather large range of the helix parameters. The foundation stiffness is found as a function of the helix pitch and the rod radius; the problem thus is reduced to a system of finite, nonlinear equations.

Slepyan, L. I.; Krylov, V. I.; Parnes, R.

2000-04-01

453

Matrix flow and densification during the consolidation of matrix coated fibres  

SciTech Connect

The consolidation of titanium alloy metal matrix composites from matrix coated fibres has been modeled using a continuum finite element approach. Predictions of time to achieve full density are in good agreement with experimental data. The predicted matrix flow has been compared with metallographic sections from samples containing novel yttria marker layers, to allow measurements of actual flow during densification. These results are also in good agreement with the predictions of the model. Densification is shown to be strongly influenced by temperature and pressure consistent with the matrix constitutive law used. However, densification is almost independent of fibre volume fraction in the range 10--50% by volume. Densification is most rapid when a uniform densifying pressure is applied, any increase in deviatoric component for the same mean pressure leads to a decrease in densification rate.

Schueler, S.; Derby, B.; Wood, M.; Ward-Close, C.

2000-04-03

454

The Activation and Function of Host Matrix Metalloproteinases in Dentin Matrix Breakdown in Caries Lesions  

Microsoft Academic Search

Matrix metalloproteinases (MMPs) are a family of enzymes which, in concert, are capable of degrading collagen. We investigated whether human MMPs could participate in the degradation of dentin organic matrix after demineralization. We performed Western blot analyses using MMP-specific antibodies to identify MMPs in human dental caries lesions. Enzymography and functional activity assays, with 125I-labeled gelatin as substrate or quantitating

L. Tjäderhane; H. Larjava; T. Sorsa; V.-J. Uitto; M. Larmas; T. Salo

1998-01-01

455

Matrix Metalloproteinase Inhibition Modulates Fibroblast-Mediated Matrix Contraction and Collagen Production In Vitro  

Microsoft Academic Search

PURPOSE. To investigate the effect of matrix metalloproteinase (MMP) inhibition on fibroblast-mediated matrix contraction and production. METHODS. Free-floating fibroblast-populated type I collagen lattices were prepared with human Tenon's capsule fibro- blasts. Lattice areas were photographed and digitally analyzed to indicate the degree of lattice contraction. Quantitative com- petitive reverse transcription-polymerase chain reaction (QCRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used

Julie T. Daniels; Alison D. Cambrey; Nicholas L. Occleston; Qian Garrett; Roy W. Tarnuzzer; Gregory S. Schultz; Peng T. Khaw

2003-01-01

456

Habitat attributes of landscape mosaics along a gradient of matrix development intensity: matrix management matters  

Microsoft Academic Search

The matrix is an important element of landscape mosaics that influences wildlife indirectly through its influence on habitat,\\u000a and directly, if they live in or move through it. Therefore, to quantify and manage habitat quality for wildlife in modified\\u000a landscapes, it is necessary to consider the characteristics of both patch and matrix elements of the whole landscape mosaic.\\u000a To isolate

Megan J. Brady; Clive A. McAlpine; Craig J. Miller; Hugh P. Possingham; Greg S. Baxter

2009-01-01

457

Pendulum impact resistance of tungsten fiber/metal matrix composites.  

NASA Technical Reports Server (NTRS)

The impact properties of copper, copper-10 nickel, and a superalloy matrix reinforced with tungsten fibers were studied. In most cases the following increased composite impact strength: increased fiber or matrix toughness, decreased fiber-matrix reaction, increased test temperature, hot working and heat treatment. Notch sensitivity was reduced by increasing fiber or matrix toughness. The effect of fiber content depended on the relative toughness of the fibers and matrix. Above 530 K a 60 volume per cent superalloy matrix composite had a greater impact strength than a turbine blade superalloy, whereas below 530 K a hot worked 56 volume per cent composite had a greater impact strength than the superalloy.

Winsa, E. A.; Petrasek, D. W.

1972-01-01

458

Matrix-driven formation of mesenchymal stem cell-extracellular matrix microtissues on soft alginate hydrogels.  

PubMed

Mesenchymal stem cells (MSCs) can be made to rearrange into microtissues in response to specific matrix cues, a process that depends on a balance between cell-matrix and cell-cell interactions. The effect of such cues, and especially their interplay, is still not fully understood, particularly in three-dimensional (3-D) systems. Here, the behaviour of human MSCs cultured within hydrogel matrices with tailored stiffness and composition was evaluated. MSC aggregation occurred only in more compliant matrices (G'? 120 Pa), when compared to stiffer ones, both in the presence and in the absence of matrix-bound arginine-glycine-aspartic acid cell-adhesion ligands (RGD; 0, 100 and 200 ?M). Fibronectin assembly stabilized cell-cell contacts within aggregates, even in non-adhesive matrices. However, MSCs were able to substantially contract the artificial matrix only when RGD was present. Moreover, compliant matrices facilitated cell proliferation and provided an environment conducive for MSC osteogenic differentiation, even without RGD. Cell interactions with the original matrix became less important as time progressed, while the de novo-produced extracellular matrix became a more critical determinant of cell fate. These data provide further insights into the mechanisms by which MSCs sense their microenvironment to organize into tissues, and provide new clues to the design of cell-instructive 3-D matrices. PMID:24607421

Maia, F Raquel; Fonseca, Keila B; Rodrigues, Gabriela; Granja, Pedro L; Barrias, Cristina C

2014-07-01

459

METCAN: The metal matrix composite analyzer  

NASA Technical Reports Server (NTRS)

Metal matrix composites (MMC) are the subject of intensive study and are receiving serious consideration for critical structural applications in advanced aerospace systems. MMC structural analysis and design methodologies are studied. Predicting the mechanical and thermal behavior and the structural response of components fabricated from MMC requires the use of a variety of mathematical models. These models relate stresses to applied forces, stress intensities at the tips of cracks to nominal stresses, buckling resistance to applied force, or vibration response to excitation forces. The extensive research in computational mechanics methods for predicting the nonlinear behavior of MMC are described. This research has culminated in the development of the METCAN (METal Matrix Composite ANalyzer) computer code.

Hopkins, Dale A.; Murthy, Pappu L. N.

1988-01-01

460

Neurosurgical reconstruction with acellular cadaveric dermal matrix.  

PubMed

Acellular cadaveric dermal matrix (ACDM) is processed from human cadaver skin (AlloDerm; Life Cell Corp., Branchburg, NJ). It does not require an immediate blood supply but can transmit essential interstitial fluids for nourishment of overlying tissues. A number of neurosurgical reconstructions have required the use of tissue that fills these specifications. The material has been used most recently for reconstruction of dura during craniotomies when primary closure is not possible or harvesting from an autologous site is not available. Because ACDM is harvested from nonneurologic cadaveric tissues and because the cellular and antigenic elements have been removed from the matrix, prion diseases are not a transmission risk. We present 6 examples of previously unreported uses of ACDM for successful repair of meningomyelocele, cauda equina, encephalocele, cerebrospinal fluid fistula, and neuroma. We propose the use of ACDM as a valuable tool in neurosurgical reconstruction. PMID:15166985

Agag, Richard L; Granick, Mark S; Omidi, Michael; Catrambone, Jeffrey; Benevenia, Joseph

2004-06-01

461

Photoacoustic measurement of lutein in biological matrix  

NASA Astrophysics Data System (ADS)

Photoacoustic (PA) spectroscopy was applied for the first time to quantify lutein in a complex biological matrix. Standard addition of lutein to a biological low-lutein matrix was used for the calibration. The PA signal was found linearly proportional (R > 0.98) to lutein concentration up to 0.3% (w/w). The dynamic range of concentrations extends to 1% (w/w) lutein. For a given experimental set-up the responsivity of PA detector within the range of linearity was estimated to 1.1 mV/1% lutein. Precision of repeated analyses is good with average RSD values of 4 and 5% for blanks and spiked samples, respectively. The analytical parameters indicate that the PA method is fast and sensitive enough for quantification of lutein in supplementary drugs and in the lutein-rich foods.

Bicanic, D.; Luterotti, S.; Becucci, M.; Fogliano, V.; Versloot, P.

2005-06-01

462

Extracellular Matrix Roles During Cardiac Repair  

PubMed Central

The cardiac extracellular matrix (ECM) provides a platform for cells to maintain structure and function, which in turn maintains tissue function. In response to injury, the ECM undergoes remodeling that involves synthesis, incorporation, and degradation of matrix proteins, with the net outcome determined by the balance of these processes. The major goals of this review are a) to serve as an initial resource for students and investigators new to the cardiac ECM remodeling field, and b) to highlight a few of the key exciting avenues and methodologies that have recently been explored. While we focus on cardiac injury and responses of the left ventricle (LV), the mechanisms reviewed here have pathways in common with other wound healing models.

Jourdan-LeSaux, Claude; Zhang, Jianhua; Lindsey, Merry L.

2010-01-01

463

Delocalization transition for the Google matrix  

NASA Astrophysics Data System (ADS)

We study the localization properties of eigenvectors of the Google matrix, generated both from the world wide web and from the Albert-Barabási model of networks. We establish the emergence of a delocalization phase for the PageRank vector when network parameters are changed. For networks with localized PageRank, eigenvalues of the matrix in the complex plane with a modulus above a certain threshold correspond to localized eigenfunctions while eigenvalues below this threshold are associated with delocalized relaxation modes. We argue that, for networks with delocalized PageRank, the efficiency of information retrieval by Google-type search is strongly affected since the PageRank values have no clear hierarchical structure in this case.

Giraud, Olivier; Georgeot, Bertrand; Shepelyansky, Dima L.

2009-08-01

464

Delocalization transition for the Google matrix.  

PubMed

We study the localization properties of eigenvectors of the Google matrix, generated both from the world wide web and from the Albert-Barabási model of networks. We establish the emergence of a delocalization phase for the PageRank vector when network parameters are changed. For networks with localized PageRank, eigenvalues of the matrix in the complex plane with a modulus above a certain threshold correspond to localized eigenfunctions while eigenvalues below this threshold are associated with delocalized relaxation modes. We argue that, for networks with delocalized PageRank, the efficiency of information retrieval by Google-type search is strongly affected since the PageRank values have no clear hierarchical structure in this case. PMID:19792200

Giraud, Olivier; Georgeot, Bertrand; Shepelyansky, Dima L

2009-08-01

465

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

466

Parallel matrix multiplication on the Connection Machine  

NASA Technical Reports Server (NTRS)

Matrix multiplication is a computation and communication intensive problem. Six parallel algorithms for matrix multiplication on the Connection Machine are presented and compared with respect to their performance and processor usage. For n by n matrices, the algorithms have theoretical running times of O(n to the 2nd power log n), O(n log n), O(n), and O(log n), and require n, n to the 2nd power, n to the 2nd power, and n to the 3rd power processors, respectively. With careful attention to communication patterns, the theoretically predicted runtimes can indeed be achieved in practice. The parallel algorithms illustrate the tradeoffs between performance, communication cost, and processor usage.

Tichy, Walter F.

1988-01-01

467

Influence of Binder in Iron Matrix Composites  

SciTech Connect

The ability to use iron and its alloys as the matrix material in composite systems is of great importance because it is the most widely used metallic material with a variety of commercially available steel grades [1]. The aim of this study is to investigate the influence of binder in particulate iron based metal matrix composites. There are four types of binder that were used in this study; Stearic Acid, Gummi Arabisch, Polyvinyl alcohol 15000 MW and Polyvinyl alcohol 22000 MW. Six different weight percentage of each binder was prepared to produce the composite materials using powder metallurgy (P/M) route; consists of dry mixing, uniaxially compacting at 750 MPa and vacuum sintering at 1100 deg. C for two hours. Their characterization included a study of density, porosity, hardness and microstructure. Results indicate that MMC was affected by the binder and stearic acid as a binder produced better properties of the composite.

Shamsuddin, S. [Faculty of Applied Science, Universiti Teknologi MARA, 02600 Arau, Perlis (Malaysia); Jamaludin, S. B. [School of Materials Engineering, Universiti Malaysia Perlis, 02600 Jejawi, Arau, Perlis (Malaysia); Hussain, Z.; Ahmad, Z. A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang, Malaysi (Malaysia)

2010-03-11

468

Random matrix triality at nonzero chemical potential  

NASA Astrophysics Data System (ADS)

We introduce three universality classes of chiral random matrix ensembles with a nonzero chemical potential and real, complex or quaternion real matrix elements. In the thermodynamic limit we find that the distribution of the eigenvalues in the complex plane does not depend on the Dyson index, and is given by the solution proposed by Stephanov. For a finite number of degrees of freedom, N, we find an accumulation of eigenvalues on the imaginary axis for real matrices, whereas for quaternion real matrices we find a depletion of eigenvalues in this domain. This effect is of order 1/N. In particular for the real case the resolvent shows a discontinuity of order 1/N. These results are in agreement with lattice QCD simulations with staggered fermions and recent instanton liquid simulations both for two colors and a nonzero chemical potential.

Halasz, M. A.; Osborn, J. C.; Verbaarschot, J. J. M.

1997-12-01

469

Integrins and Extracellular Matrix in Mechanotransduction  

PubMed Central

Integrins bind extracellular matrix fibrils and associate with intracellular actin filaments through a variety of cytoskeletal linker proteins to mechanically connect intracellular and extracellular structures. Each component of the linkage from the cytoskeleton through the integrin-mediated adhesions to the extracellular matrix therefore transmits forces that may derive from both intracellular, myosin-generated contractile forces and forces from outside the cell. These forces activate a wide range of signaling pathways and genetic programs to control cell survival, fate, and behavior. Additionally, cells sense the physical properties of their surrounding environment through forces exerted on integrin-mediated adhesions. This article first summarizes current knowledge about regulation of cell function by mechanical forces acting through integrin-mediated adhesions and then discusses models for mechanotransduction and sensing of environmental forces.

Schwartz, Martin Alexander

2010-01-01

470

Matrix control of transforming growth factor-? function.  

PubMed

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

2012-10-01

471

Universal shocks in random matrix theory  

NASA Astrophysics Data System (ADS)

We link the appearance of universal kernels in random matrix ensembles to the phenomenon of shock formation in some fluid dynamical equations. Such equations are derived from Dyson’s random walks after a proper rescaling of the time. In the case of the Gaussian unitary ensemble, on which we focus in this paper, we show that the characteristics polynomials and their inverse evolve according to a viscid Burgers equation with an effective “spectral viscosity” ?s=1/2N , where N is the size of the matrices. We relate the edge of the spectrum of eigenvalues to the shock that naturally appears in the Burgers equation for appropriate initial conditions, thereby suggesting a connection between the well-known microscopic universality of random matrix theory and the universal properties of the solution of the Burgers equation in the vicinity of a shock.

Blaizot, Jean-Paul; Nowak, Maciej A.

2010-11-01

472

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

473

Ceramic fiber ceramic matrix filter development  

SciTech Connect

The objectives of this project were to develop a novel type of candle filter based on a ceramic fiber-ceramic matrix composite material, and to extend the development to full-size, 60-mm OD by 1-meter-long candle filters. The goal is to develop a ceramic filter suitable for use in a variety of fossil energy system environments such as integrated coal gasification combined cycles (IGCC), pressurized fluidized-bed combustion (PFBC), and other advanced coal combustion environments. Further, the ceramic fiber ceramic matrix composite filter, hereinafter referred to as the ceramic composite filter, was to be inherently crack resistant, a property not found in conventional monolithic ceramic candle filters, such as those fabricated from clay-bonded silicon carbide. Finally, the adequacy of the filters in the fossil energy system environments is to be proven through simulated and in-plant tests.

Judkins, R.R.; Stinton, D.P. [Oak Ridge National Lab., TN (United States); Smith, R.G.; Fischer, E.M. [3M Company, St. Paul, MN (United States)

1994-09-01

474

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.’

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

2012-01-01

475

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

476

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

477

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

478

Matrix transformations for spacecraft attitude determination  

NASA Technical Reports Server (NTRS)

A common problem for experimental space physicists is the determination of the attitude matrix T which transforms vectors between representations in X and X' coordinate systems according to (vector V sub X) = (T sub XX')(vector V sub X'). A straightforward, simple, and efficient solution for the transformation matrix is a double-cross transformation. It is calculated from any two directions A and B, which are vectors normalized to unit length and are known in both X and X' coordinates. The B direction need be known only well enough to define the plane in which vectors A and B lie. The problem of the intersection of two cones as applicable to attitude solutions is also discussed.

Cauffman, D. P.

1972-01-01

479

Nuclear matrix elements for double-? decay  

NASA Astrophysics Data System (ADS)

Background: Direct determination of the neutrino mass through double-? decay is at the present time one of the most important areas of experimental and theoretical research in nuclear and particle physics.Purpose: We calculate nuclear matrix elements for the extraction of the average neutrino mass in neutrinoless double-? decay.Methods: The microscopic interacting boson model (IBM-2) is used.Results: Nuclear matrix elements in the closure approximation are calculated for 48Ca, 76Ge, 82Se, 96Zr, 100Mo, 110Pd, 116Cd, 124Sn, 128Te, 130Te, 148Nd, 150Nd, 154Sm, 160Gd, and 198Pt decay.Conclusions: Realistic predictions for the expected half-lives in neutrinoless double-? decay with light and heavy neutrino exchange in terms of neutrino masses are made and limits are set from current experiments.

Barea, J.; Kotila, J.; Iachello, F.

2013-01-01

480

Dentin sialophosphoprotein expression during human matrix development.  

PubMed

Dentin sialophosphoprotein (DSPP) is a phosphorylated parent protein that is cleaved post-translationally into three dentin components: dentin sialoprotein, dentin glycoprotein, and dentin phosphoprotein. In this study we evaluated the dentin sialophosphoprotein expression in human tooth germs to determine its role in tooth development and matrix deposition. DSPP gene expression was investigated performing reverse-transcription polymerase chain-reaction (RT-PCR) and a microarray analysis carried out using high density array containing 21.329 transcripts in replicates. To test for the expression of the DSPP protein, were performed western immunoblot and immunohistochemical analysis during different phases of tissues and matrix formation. All the analysis performed showed high expression level of DSPP in human tooth germs indicating that it may play an essential role for physiological and pathological events in tooth development. PMID:18211748

Mastrangelo, F; Scioletti, A P; Tranasi, M; Tecco, S; Sberna, M T; Vinci, R; Grilli, A; Stuppia, L; Gherlone, E; Tete, S

2007-01-01

481

Extracellular Matrix and Its Role in Spermatogenesis  

Microsoft Academic Search

In adult mammalian testes, such as rats, Sertoli and germ cells at different stages of their development in the seminiferous\\u000a epithelium are in close contact with the basement membrane, a modified form of extracellular matrix (ECM). In essence, Sertoli\\u000a and germ cells in particular spermatogonia are “resting” on the basement membrane at different stages of the seminiferous\\u000a epithelial cycle, relying

Michelle K. Y. Siu; C. Yan Cheng

482

Matrix metalloproteinases in tumorigenesis: an evolving paradigm  

Microsoft Academic Search

Proteases are crucial for development, tissue remodeling, and tumorigenesis. Matrix metalloproteinases (MMPs) family, in particular,\\u000a consists of more than 20 members with unique substrates and diverse function. The expression and activity of MMPs in a variety\\u000a of human cancers have been intensively studied. MMPs have well-recognized roles in the late stage of tumor progression, invasion,\\u000a and metastasis. However, increasing evidence

Hui Hua; Minjing Li; Ting Luo; Yancun Yin; Yangfu Jiang

483

MATRIX APPROACH TO DISCRETE FRACTIONAL CALCULUS  

Microsoft Academic Search

A matrix form representation of discrete analogues of various forms of frac-tional di erentiation and fractional integration is suggested. The approach, which is described in this paper, unifies the numerical di eren-tiation of integer order and the n-fold integration, using the so-called triangular strip matrices. Applied to numerical solution of di erential equations, it also uni-fies the solution of ordinary

Igor Podlubny

484

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

485

Matrix metalloproteinases degrade myelin basic protein  

Microsoft Academic Search

Matrix metalloproteinases (MMPs) are a group of enzymes responsible for the degradation of interstitial connective tissue and basement membrane. The coding sequences for five of the human MMPs, viz. interstitial collagenase, 72 kDa gelatinase, stromelysin-1, matrilysin and 92 kDa gelatinase, were cloned and expressed in Chinese hamster ovary cells, and the proteins purified. The enzymes were compared for their ability

Stephen Chandler; Rachael Coates; Andrew Gearing; Jon Lury; Graham Wells; Elisabeth Bone

1995-01-01

486

Indentation Tests on Al Matrix Syntactic Foams  

Microsoft Academic Search

This paper investigates mechanical response of Al matrix syntactic foams manufactured by pressure infiltration casting under\\u000a indentation test. Syntactic foams with ceramic microspheres of three different particle sizes and inner structures were manufactured\\u000a and tested. Because the hollow microspheres are stronger than the porous ones, the syntactic foam with hollow microspheres\\u000a has a higher compressive strength than that of the

X. F. Tao; G. K. Schleyer; Y. Y. Zhao

487

Series Expansions of Generalized Matrix Products  

Microsoft Academic Search

We consider generalized products of random matrices. They arise in discrete event systems (DES), such as queueing networks or stochastic Petri nets, where they are used to express the state transition dynamic. Instances of such DES are those whose state dynamic can be modelled through a matrix-vector multiplication in conventional, max-plus and min-plus algebra. We will present a Taylor series

Haralambie Leahu; Bernd Heidergott

2005-01-01

488

Energy-Efficient Matrix Multiplication on FPGAs  

Microsoft Academic Search

We develop new algorithms and architectures for matrix multiplication on cofigurable devices. These designs significantly\\u000a reduce the energy dissipation and latency compared with the state-of-the-art FPGA-based designs. We derive functions to represent\\u000a the impact of algorithmic level design choices on the system-wide energy dissipation, latency, and area by capturing algorithm\\u000a and architecture details including features of the target FPGA. The

Ju-wook Jang; Seonil Choi; Viktor K. Prasanna

2002-01-01

489

Data Distributions for Sparse Matrix Vector Multiplication  

Microsoft Academic Search

Sparse matrix vector multiplication (SpMxV) is often one of the core components of manyscientific applications. Many authors have proposed methods for its data distribution in distributedmemory multiprocessors. We can classify these into four groups: Scatter, D-Way Strip, Recursive andMiscellaneous. In this work we propose a new method (Multiple Recursive Decomposition (MRD)),which partitions the data using the prime factors of the

Luis F. Romero; Emilio L. Zapata

1995-01-01

490

Sparse Matrix-Vector multiplication on FPGAs  

Microsoft Academic Search

Floating-point Sparse Matrix-Vector Multiplication (SpMXV) is a key computational kernel in scientific and engineering applications. The poor data locality of sparse matrices significantly reduces the performance of SpMXV on general-purpose processors, which rely heavily on the cache hierarchy to achieve high performance. The abundant hardware resources on current FPGAs provide new opportunities to improve the performance of SpMXV. In this

Ling Zhuo; Viktor K. Prasanna

2005-01-01

491

Generalized Cannon's algorithm for parallel matrix multiplication  

Microsoft Academic Search

Cannon’s algorithm is a memory-efficient matrix multiplication technique for parallel computers with toroidal mesh interconnections. This algorithm assumes that input matrices are block distributed, but it is not clear how it can deal with block-cyclic distributed matrices. This paper generalizes Cannon’s algorithm for the case when input matrices are blockcyclic distributed across a two-dimensional processor array with an arbitrary number

Hyuk-Jae Lee; James P. Robertson; José A. B. Fortes

1997-01-01

492

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