Sample records for tabular list-format matrix

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

    NASA Astrophysics Data System (ADS)

    Siegel, Carl Ludwig; Siegel, Edward Carl-Ludwig

    2011-03-01

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

  2. XML Restructuring and Integration for Tabular Data

    Microsoft Academic Search

    Wei Yu; Z. Meral Ozsoyoglu; Gultekin Ozsoyoglu

    \\u000a We study the data integration and restructuring issues of tabular data. We consider the case where the same set of data is\\u000a collected from independent sites, stored in different DBMSs or other repositories, organized in different tabular or equivalent\\u000a semi-structured formats, and published on the web. These sites transform tabular data into XML data with possible syntactic\\u000a discrepancies in their

  3. List Formats Improve Medication Instructions for Older Adults.

    ERIC Educational Resources Information Center

    Morrow, Daniel; And Others

    1995-01-01

    In 3 experiments older adults (n=27, n=36, and n=27) were given medication instructions as categorized lists, simple lists, or paragraphs. The first group preferred categorized lists; the second answered questions about listed instructions more quickly, and the third group recalled more information from simple lists. List format was considered…

  4. 1 CFR 18.10 - Illustrations, tabular material, and forms.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2012-01-01 true Illustrations, tabular material, and forms. ...OF DOCUMENTS GENERALLY § 18.10 Illustrations, tabular material, and forms. ...it is necessary to publish a form or illustration, a clear and legible original...

  5. 1 CFR 18.10 - Illustrations, tabular material, and forms.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Illustrations, tabular material, and forms. ...OF DOCUMENTS GENERALLY § 18.10 Illustrations, tabular material, and forms. ...it is necessary to publish a form or illustration, a clear and legible original...

  6. 1 CFR 18.10 - Illustrations, tabular material, and forms.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Illustrations, tabular material, and forms. ...OF DOCUMENTS GENERALLY § 18.10 Illustrations, tabular material, and forms. ...it is necessary to publish a form or illustration, a clear and legible original...

  7. 1 CFR 18.10 - Illustrations, tabular material, and forms.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Illustrations, tabular material, and forms. ...OF DOCUMENTS GENERALLY § 18.10 Illustrations, tabular material, and forms. ...it is necessary to publish a form or illustration, a clear and legible original...

  8. 1 CFR 18.10 - Illustrations, tabular material, and forms.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2012-01-01 true Illustrations, tabular material, and forms. ...OF DOCUMENTS GENERALLY § 18.10 Illustrations, tabular material, and forms. ...it is necessary to publish a form or illustration, a clear and legible original...

  9. A Distribution-Free Tabular CUSUM Chart for Autocorrelated Data

    E-print Network

    Kim, Seong-Hee

    A Distribution-Free Tabular CUSUM Chart for Autocorrelated Data SEONG-HEE KIM, CHRISTOS ALEXOPOULOS Raleigh, NC 27695-7906 A distribution-free tabular CUSUM chart is designed to detect shifts in the mean of an autocorrelated process. The chart's average run length (ARL) is approximated by gener- alizing Siegmund's ARL

  10. Formation of tabular plutons - results and implications of centrifuge modelling

    Microsoft Academic Search

    Carlo DIETL; Hemin KOYI

    2008-01-01

    * ?Correspondingauthor Geophysical investigations reveal that many granitoid plutons possess a tabular shape: either laccolithic, lopolithic or phacolithic. In this study, the results of a centrifuge experiment are used to understand the formation mechanisms of these features. The model was build of a sequence of 14 differently coloured plasticine layers. Two buoyant layers - with a volume of c. 40

  11. Min-cut segmentation of cursive handwriting in tabular documents

    NASA Astrophysics Data System (ADS)

    Davis, Brian L.; Barrett, William A.; Swingle, Scott D.

    2015-01-01

    Handwritten tabular documents, such as census, birth, death and marriage records, contain a wealth of information vital to genealogical and related research. Much work has been done in segmenting freeform handwriting, however, segmentation of cursive handwriting in tabular documents is still an unsolved problem. Tabular documents present unique segmentation challenges caused by handwriting overlapping cell-boundaries and other words, both horizontally and vertically, as "ascenders" and "descenders" overlap into adjacent cells. This paper presents a method for segmenting handwriting in tabular documents using a min-cut/max-flow algorithm on a graph formed from a distance map and connected components of handwriting. Specifically, we focus on line, word and first letter segmentation. Additionally, we include the angles of strokes of the handwriting as a third dimension to our graph to enable the resulting segments to share pixels of overlapping letters. Word segmentation accuracy is 89.5% evaluating lines of the data set used in the ICDAR2013 Handwriting Segmentation Contest. Accuracy is 92.6% for a specific application of segmenting first and last names from noisy census records. Accuracy for segmenting lines of names from noisy census records is 80.7%. The 3D graph cutting shows promise in segmenting overlapping letters, although highly convoluted or overlapping handwriting remains an ongoing challenge.

  12. Towards Logical Analysis of Tabular Rule-Based Systems

    Microsoft Academic Search

    Antoni Ligeza

    1998-01-01

    Rule based systems constitute the most popular tool for specification of operational knowledge in majority of knowledge based systems. The paper addresses the issue of analysis and verification of selected properties of such systems in a systematic way. A uniform, tabular form of single level rule based systems is put forward. Such systems can be used independently as a generalized

  13. Consistent thermodynamic derivative estimates for tabular equations of state

    Microsoft Academic Search

    Gary A. Dilts

    2006-01-01

    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

  14. 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)

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

    2010-07-01

    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.

  15. Applying Data Privacy Techniques on Tabular Data in Uganda

    E-print Network

    Mivule, Kato

    2011-01-01

    The growth of Information Technology(IT) in Africa has led to an increase in the utilization of communication networks for data transaction across the continent. A growing number of entities in the private sector, academia, and government, have deployed the Internet as a medium to transact in data, routinely posting statistical and non statistical data online and thereby making many in Africa increasingly dependent on the Internet for data transactions. In the country of Uganda, exponential growth in data transaction has presented a new challenge: What is the most efficient way to implement data privacy. This article discusses data privacy challenges faced by the country of Uganda and implementation of data privacy techniques for published tabular data. We make the case for data privacy, survey concepts of data privacy, and implementations that could be employed to provide data privacy in Uganda.

  16. Consistent thermodynamic derivative estimates for tabular equations of state

    E-print Network

    Dilts, G A

    2005-01-01

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

  17. 17 CFR 232.305 - Number of characters per line; tabular and columnar information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 false Number of characters per line; tabular and columnar information...Submissions § 232.305 Number of characters per line; tabular and columnar information...portion of a document shall not exceed 80 characters per line, including blank...

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

    Microsoft Academic Search

    Luke A. D. Hutchison; William A. Barrett

    2004-01-01

    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

  19. Summer Decay Processes in a Large Tabular Iceberg

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  20. Consistent thermodynamic derivative estimates for tabular equations of state

    NASA Astrophysics Data System (ADS)

    Dilts, Gary A.

    2006-06-01

    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.

  1. Consistent thermodynamic derivative estimates for tabular equations of state.

    PubMed

    Dilts, Gary A

    2006-06-01

    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

  2. Analyzing Tabular and State-Transition Requirements Specifications in PVS

    NASA Technical Reports Server (NTRS)

    Owre, Sam; Rushby, John; Shankar, Natarajan

    1997-01-01

    We describe PVS's capabilities for representing tabular specifications of the kind advocated by Parnas and others, and show how PVS's Type Correctness Conditions (TCCs) are used to ensure certain well-formedness properties. We then show how these and other capabilities of PVS can be used to represent the AND/OR tables of Leveson and the Decision Tables of Sherry, and we demonstrate how PVS's TCCs can expose and help isolate errors in the latter. We extend this approach to represent the mode transition tables of the Software Cost Reduction (SCR) method in an attractive manner. We show how PVS can check these tables for well-formedness, and how PVS's model checking capabilities can be used to verify invariants and reachability properties of SCR requirements specifications, and inclusion relations between the behaviors of different specifications. These examples demonstrate how several capabilities of the PVS language and verification system can be used in combination to provide customized support for specific methodologies for documenting and analyzing requirements. Because they use only the standard capabilities of PVS, users can adapt and extend these customizations to suit their own needs. Those developing dedicated tools for individual methodologies may find these constructions in PVS helpful for prototyping purposes, or as a useful adjunct to a dedicated tool when the capabilities of a full theorem prover are required. The examples also illustrate the power and utility of an integrated general-purpose system such as PVS. For example, there was no need to adapt or extend the PVS model checker to make it work with SCR specifications described using the PVS TABLE construct: the model checker is applicable to any transition relation, independently of the PVS language constructs used in its definition.

  3. The functional role of tabular structures for large reef fishes: avoiding predators or solar irradiance?

    NASA Astrophysics Data System (ADS)

    Kerry, J. T.; Bellwood, D. R.

    2015-06-01

    Large reef fishes may often be seen sheltering under tabular structures on coral reefs. There are two principle explanations for this behaviour: avoidance of predation or avoidance of solar irradiance. This study sought supporting evidence to distinguish between these two explanations by examining the usage of tabular structures on a shallow mid-shelf reef of the Great Barrier Reef at midday and sunset. If predation avoidance is most important, usage should increase towards sunset; conversely, if avoidance of solar radiation is most important, more fishes should use cover at midday. Underwater video observations revealed that tabular structures were extensively used by large reef fishes at midday, being characterised by numerous species, especially Lutjanidae and Haemulidae. In contrast, at sunset, tabular structures were used by significantly fewer large reef fishes, being characterised mostly by species of unicornfish ( Naso spp.). Resident times of fishes using tabular structures were also significantly longer at midday (28:06 ± 5:55 min) than at sunset (07:47 ± 2:19 min). The results suggest that the primary function of tabular structures for large reef fishes is the avoidance of solar irradiance. This suggestion is supported by the position of fishes when sheltering. The majority of large reef fishes were found to shelter under the lip of tabular structure, facing outwards. This behaviour is thought to allow protection from harmful downwelling UV-B irradiance while allowing the fish to retain photopic vision and survey more of the surrounding area. These findings help to explain the importance of tabular structures for large reef fishes on coral reefs, potentially providing a valuable energetic refuge from solar irradiance.

  4. The role of {1 0 0} side faces for lateral growth of tabular silver bromide crystals

    NASA Astrophysics Data System (ADS)

    Bögels, G.; Meekes, H.; Bennema, P.; Bollen, D.

    1998-07-01

    In this study the growth of {1 1 1} tabular silver bromide crystals will be examined in situ under different conditions to determine a general growth mechanism. We established the side-face structure and aspect ratio of the tabular crystals for different concentrations of silver bromide dissolved in DMSO during the growth. The morphology of non-twinned crystals was studied to examine the relative growth rate of the {1 0 0} faces as compared to the {1 1 1} faces. It will be shown that there is a strong dependency between the relative growth rate of the {1 0 0} faces and the aspect ratio and side-face structures of the {1 1 1} tabular crystals. Relative fast growth of the {1 0 0} faces in comparison to the {1 1 1} faces leads to high aspect ratios and side-face structures with acute edges built up by {1 1 1} side faces. Relative slower growth leads to lower aspect ratios and ridge side-face structures built up by stable {1 1 1} and {1 0 0} faces. The lateral growth for all conditions can be explained by the substep mechanism proposed in an earlier study. This mechanism explains the increase of growth rate of a {1 1 1} side face that is linked via a twin plane to a faster growing {1 0 0} side face. From this mechanism and the observations it will be shown that the faces between the twin planes for double-twinned tabular crystals can be determined. The results presented here are not only valid for tabular crystals grown in the DMSO system but also for tabular crystals grown from the vapour phase and in the industrial precipitation method.

  5. Fourier-Mellin registration of line-delineated tabular document images

    Microsoft Academic Search

    Luke A. D. Hutchison; William A. Barrett

    2006-01-01

    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

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

    E-print Network

    Stewart, Sarah T.

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

  7. Agribusiness and Natural Resources Education in Michigan. Job Competencies Needed. A Tabular Supplement to the Final Report.

    ERIC Educational Resources Information Center

    Thuemmel, William L.; And Others

    This manual contains a tabular report of the competency identification of job task analysis component (Part Two) of the research project entitled "Agribusiness and Natural Resources Education in Michigan: Employment Demand, Competencies Required, and Recommended Delivery Systems." The data is a tabular supplement to Chapter III of the final…

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

    NASA Astrophysics Data System (ADS)

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

    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).

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

    USGS Publications Warehouse

    Sanford, R.F.

    1990-01-01

    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

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

    Microsoft Academic Search

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

    2010-01-01

    Ca-doped ceria (CDC)\\/tabular titanate (K0.8Li0.27Ti1.73O4, 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

  11. Room temperature synthesis of silver nanowires from tabular silver bromide crystals in the presence of gelatin

    SciTech Connect

    Liu Suwen [Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrignton Oval, Room 208, Norman, OK 73019 (United States); Wehmschulte, Rudolf J. [Department of Chemistry, Florida Institute of Technology, 150 West University Blvd., Melbourne, FL 32901 (United States)]. E-mail: rwehmsch@fit.edu; Lian Guoda [Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrignton Oval, Room 208, Norman, OK 73019 (United States); Burba, Christopher M. [Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrignton Oval, Room 208, Norman, OK 73019 (United States)

    2006-03-15

    Long silver nanowires were synthesized at room temperature by a simple and fast process derived from the development of photographic films. A film consisting of an emulsion of tabular silver bromide grains in gelatin was treated with a photographic developer (4-(methylamino)phenol sulfate (metol), citric acid) in the presence of additional aqueous silver nitrate. The silver nanowires have lengths of more than 50 {mu}m, some even more than 100 {mu}m, and average diameters of about 80 nm. Approximately, 70% of the metallic silver formed in the reduction consists of silver nanowires. Selected area electron diffraction (SAED) results indicate that the silver nanowires grow along the [111] direction. It was found that the presence of gelatin, tabular silver bromide crystals and silver ions in solution are essential for the formation of the silver nanowires. The nanowires appear to originate from the edges of the silver bromide crystals. They were characterized by transmission electron microscopy (TEM), SAED, scanning electron microscopy (SEM), and powder X-ray diffraction (XRD)

  12. Atomic force microscopy studies on the surface morphology of {1 1 1} tabular AgBr crystals

    NASA Astrophysics Data System (ADS)

    Plomp, M.; Buijnsters, J. G.; Bögels, G.; van Enckevort, W. J. P.; Bollen, Dirk

    2000-02-01

    Both ex situ and in situ atomic force microscopy have been applied to study the {1 1 1} and {1 0 0} surfaces of tabular silver bromide crystals grown from dimethyl sulphoxide-water solutions. This resulted in observations of monosteps, macrosteps, etch pits, pinning of steps and nucleated crystals showing twin planes. These examinations indicate that the growth and dissolution of both the {1 0 0} and the polar {1 1 1} faces occur via steps in many configurations. The registered 40-nm distance between the parallel twin planes of the nucleated crystals agrees with transmission electron microscopy measurements done on tabular crystals grown by the industrial double-jet precipitation method.

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

    SciTech Connect

    Carpenter, John H.; Belcourt, Noel

    2013-04-01

    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

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

    PubMed Central

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

    2004-01-01

    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 CO2-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-CO2) 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

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  17. 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

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

    2005-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

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

    USGS Publications Warehouse

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

    1990-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

    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.

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

    SciTech Connect

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2006-05-01

    ‘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.

  3. XML/VOTable and Simple ASCII Tabular Output from NED with Sample Applications

    NASA Astrophysics Data System (ADS)

    Schmitz, M.; Pevunova, O.; Mazzarella, J.; Good, J.; Berriman, B.; Madore, B.; NED Team

    2005-12-01

    The NASA/IPAC Extragalactic Database (NED) provides data and cross-identifications for over 8 million objects fused from thousands of survey catalogs and journal articles. The data cover all frequencies from radio through gamma rays and include positions, redshifts, photometry and spectral energy distributions (SEDs), sizes, and images. NED services have traditionally supplied data in HTML format for connections from Web browsers, and a custom ASCII data structure for connections by remote computer programs written in C. We demonstrate new services that provide responses from NED queries in XML documents compliant with the international virtual observatory VOTable protocol, as well as simple tab-separated or comma-separated values (CSV). The NED services that support the new tabular output include By Name, Near Name and Near Position (cone searches), All-Sky searches based on object parameters (survey names, cross-IDs, redshifts, flux densities), and queries for images, photometry/SEDs, redshifts, positions, and diameters. The VOTable services have been integrated into the NVO registry, and they are also available directly from NED's Web interface (http://nedwww.ipac.caltech.edu). This development greatly simplifies the integration of data from NED into visualization and analysis packages, scripts, and other applications. We illustrate an example of importing a NED SED into Excel, as well as plotting and comparing SEDs using the VOPlot Java applet. NED is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The XML/VOTable portion of this work was funded by the US National Virtual Observatory, which is sponsored by the National Science Foundation. We also acknowledge assistance from the NVO Technical Working Group.

  4. Google matrix 1 Google matrix

    E-print Network

    Shepelyansky, Dima

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

  5. Google matrix 1 Google matrix

    E-print Network

    Shepelyansky, Dima

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

  6. 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

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

    2007-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Roddy, D. J.

    1977-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Pototzky, Anthony S.

    2008-01-01

    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.

  9. Matrix Operations

    NSDL National Science Digital Library

    Blake, Lewis

    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.

  10. Matrix superpotentials

    E-print Network

    Nikitin, A G

    2011-01-01

    We present a collection of matrix valued shape invariant potentials which give rise to new exactly solvable problems of SUSY quantum mechanics. It includes all irreducible matrix superpotentials of the generic form $W=kQ+\\frac1k R+P$ where $k$ is a variable parameter, $Q$ is the unit matrix multiplied by a function of independent variable $x$, and $P$, $R$ are hermitian matrices depending on $x$. In particular we recover the Pron'ko-Stroganov "matrix Coulomb potential" and all known scalar shape invariant potentials of SUSY quantum mechanics.

  11. Matrix superpotentials

    NASA Astrophysics Data System (ADS)

    Nikitin, Anatoly G.; Karadzhov, Yuri

    2011-07-01

    We present a collection of matrix-valued shape invariant potentials which give rise to new exactly solvable problems of SUSY quantum mechanics. It includes all irreducible matrix superpotentials of the generic form W=kQ+\\frac{1}{k} R+P, where k is a variable parameter, Q is the unit matrix multiplied by a real-valued function of independent variable x, and P and R are the Hermitian matrices depending on x. In particular, we recover the Pron'ko-Stroganov 'matrix Coulomb potential' and all known scalar shape invariant potentials of SUSY quantum mechanics. In addition, five new shape invariant potentials are presented. Three of them admit a dual shape invariance, i.e. the related Hamiltonians can be factorized using two non-equivalent superpotentials. We find discrete spectrum and eigenvectors for the corresponding Schrödinger equations and prove that these eigenvectors are normalizable.

  12. Matrix converters

    Microsoft Academic Search

    P. W. Wheeler; J. C. Clare; L. Empringham; M. Bland; K. G. Kerris

    2004-01-01

    This paper deals with the vector-controlled MCT matrix converter induction motor drive with minimized commutation time and enchanced waveform quality. It also deals with the design, construction, and testing of a 10-kVA three-phase to three-phase matrix converter induction motor drive. The converter has been built using discrete 65 A metal-oxide-semiconductor (MOS) controlled thyristors (MCTs). The commutation time has been minimized

  13. 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

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

    2006-01-01

    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).

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  15. The NOAA Tide Predictions application provides predictions in both graphical and tabular formats, with many user selected options, for over 3000 stations broken down by key areas in each state.

    E-print Network

    The NOAA Tide Predictions application provides predictions in both graphical and tabular formats. Station Types: The NOAA Tide Predictions application provides predictions from 2 distinct categories by combining the harmonic constituents into a single tide curve. Subordinate - The high and low height values

  16. MatrixDB, the extracellular matrix interaction database: updated content, a new navigator and expanded functionalities.

    PubMed

    Launay, G; Salza, R; Multedo, D; Thierry-Mieg, N; Ricard-Blum, S

    2015-01-01

    MatrixDB (http://matrixdb.ibcp.fr) is a freely available database focused on interactions established by extracellular proteins and polysaccharides. It is an active member of the International Molecular Exchange (IMEx) consortium and has adopted the PSI-MI standards for annotating and exchanging interaction data, either at the MIMIx or IMEx level. MatrixDB content has been updated by curation and by importing extracellular interaction data from other IMEx databases. Other major changes include the creation of a new website and the development of a novel graphical navigator, iNavigator, to build and expand interaction networks. Filters may be applied to build sub-networks based on a list of biomolecules, a specified interaction detection method and/or an expression level by tissue, developmental stage, and health state (UniGene data). Any molecule of the network may be selected and its partners added to the network at any time. Networks may be exported under Cytoscape and tabular formats and as images, and may be saved for subsequent re-use. PMID:25378329

  17. 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.

  18. Thread Organization and Matrix Multiplication matrix matrix multiplication

    E-print Network

    Verschelde, Jan

    Thread Organization and Matrix Multiplication 1 PyCUDA matrix matrix multiplication 2 Thread Multiplication L-32 4 April 2014 1 / 37 #12;about PyCUDA A. Klöckner, N. Pinto, Y. Lee, B. Catanzaro, P. Ivanov, and A. Fasih: PyCUDA and PyOpenCL: A scripting-based approach to GPU run-time code generation. Parallel

  19. Tabular Privacyy Preserving Publishingg g

    E-print Network

    Zhang, Jun

    Computer Back pain A04 56 F Government 610020 Sports Heart disease A05 47 M Police 610020 Music Neck pain Neck pain Bill 47 M Police 610020 Music Heart disease Explicit Identifier (e.g. name, ID #, Driver 610020 Sports Neck pain Bill 47 M Police 610020 Music Heart disease In the table 1. The value of every

  20. Fuzzyics =CATEGORYICS =PRAGMATYICS (``Son of ``TRIZ''')/CATEGORY-SEMANTICS Cognition (fcp/csc) of Plato-Aristotle ``SQUARE-of-OPPOSITION''(SoO): Linguistics: Antonyms VS ``SYNONYMS'' VS Analogy/ Metaphor: Coarsest-Possible Topology: Shocks/High-Pressures Applications

    NASA Astrophysics Data System (ADS)

    Siegel, Edward Plato Aristotle Archimedes Carl-Ludwig; Young, Frederic; Lewis, Thomas

    2013-06-01

    Siegel[MRS Fall-Mtgs,:Symp.Fractals(89)-5-papers!!!;Symp.Scaling(90)] FCP/CSC {aka SPD}(Tic-Tac-Toe-Matrix/Tabular List-Format) ``COMMON-FUNCTIONING-PRINCIPLE'' DI/TRI-CHOTOMY GENERIC ``INEVITABILITY_-WEB'' PURPOSEFUL PARSIMONY-of-DI/TRI-CHOTOMY STRATEGY REdiscovery of SoO automatically/optimality is in NON-list-format/matrix: DIMENSIONALITY-DOMINATION -INEVIT-ABILITY ROOT-CAUSE(RC) ULTIMATE-ORIGIN(UO): (level-0.-logic) DIMENSIONALITY (level-0. logic): [dst = ODD-Z] <->{Dst=FRACTAL-UNcertainty FLUCTUATIONS} <->(dst = EVEN-Z): CAUSES: (level- I.-logic): EXTENT/SCALE/RADIUS: (relative)-[LOCALITY] <-> (relative)-(...GLOBALITY...) & (level-II.-logic): POWER-SPECTRUM{noise ?generalized-susceptibility}: [``l''/?0-White] <->(...-``l''/? 1 . 000 . . . - HYPERBOLICITY...) & (level-III.-logic) CRITICAL-EXPONENT:n =0 <->n = 1.000... ; BUT ALL 3 ALSO CAUSED BY ANOTHER INdependent RCUO (level-IV.-logic):

  1. MANIPULATING MATRIX INEQUALITIES AUTOMATICALLY

    E-print Network

    Helton, J. William

    systems problems convert directly into matrix inequalities. Matrix inequalities take the form of a listMANIPULATING MATRIX INEQUALITIES AUTOMATICALLY J. WILLIAM HELTON #3; Abstract. Matrix inequalities problem presents and converting these to a nice form, or at least checking if they already have or do

  2. Fire Model Matrix

    NSDL National Science Digital Library

    COMET

    2008-02-05

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

  3. Learning with Matrix Factorizations

    E-print Network

    Srebro, Nathan

    Learning with Matrix Factorizations Nati Srebro Department of Electrical Engineering and Computer Reduction yy u V' YY datadata U titles users titles � #12;Matrix Factorization V' YY datadata U X rank k ­ Clustering as an extreme (when rows of U sparse) · Unconstrained: Low Rank Approximation #12;Matrix

  4. Scaling a unitary matrix

    E-print Network

    Alexis De Vos; Stijn De Baerdemacker

    2015-02-06

    The iterative method of Sinkhorn allows, starting from an arbitrary real matrix with non-negative entries, to find a so-called 'scaled matrix' which is doubly stochastic, i.e. a matrix with all entries in the interval (0, 1) and with all line sums equal to 1. We conjecture that a similar procedure exists, which allows, starting from an arbitrary unitary matrix, to find a scaled matrix which is unitary and has all line sums equal to 1. The existence of such algorithm guarantees a powerful decomposition of an arbitrary quantum circuit.

  5. Biofilm Matrix Proteins

    PubMed Central

    Fong, Jiunn N. C.; Yildiz, Fitnat H.

    2015-01-01

    Proteinaceous components of the biofilm matrix include secreted extracellular proteins, cell surface adhesins and protein subunits of cell appendages such as flagella and pili. Biofilm matrix proteins play diverse roles in biofilm formation and dissolution. They are involved in attaching cells to surfaces, stabilizing the biofilm matrix via interactions with exopolysaccharide and nucleic acid components, developing three-dimensional biofilm architectures, and dissolving biofilm matrix via enzymatic degradation of polysaccharides, proteins, and nucleic acids. In this chapter, we will review functions of matrix proteins in a selected set of microorganisms, studies of the matrix proteomes of Vibrio cholerae and Pseudomonas aeruginosa, and roles of outer membrane vesicles and of nucleoid-binding proteins in biofilm formation. PMID:26104709

  6. Matrix product operator representations

    E-print Network

    V. Murg; J. I. Cirac; B. Pirvu; F. Verstraete

    2008-04-24

    We show how to construct relevant families of matrix product operators in one and higher dimensions. Those form the building blocks for the numerical simulation methods based on matrix product states and projected entangled pair states. In particular, we construct translational invariant matrix product operators suitable for time evolution, and show how such descriptions are possible for Hamiltonians with long-range interactions. We illustrate how those tools can be exploited for constructing new algorithms for simulating quantum spin systems.

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

    USGS Publications Warehouse

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

    2006-01-01

    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).

  8. Flexible transistor matrix (FTM)

    Microsoft Academic Search

    King C. Ho; Sarma Sastry

    1991-01-01

    This paper describes a new layout style called the Flexible Transistor Matrix (FTM) for large scale CMOS module generation. FTM uses two layers of metal. Compared to Gate Matrix, FTM can generate significantly better results. In addition, the algorithm can control the aspect ratio, 1\\/0 pin positions and different transistor sizes.

  9. Understand FCC matrix technology

    SciTech Connect

    Rajagopalan, K.; Habib, E.T. Jr. (W.R. Grace and Co., Columbia, MD (United States))

    1992-09-01

    This paper reports that while performance improvements in FCC catalysts have been well documented over the years, most technology reviews have concentrated on zeolite improvements. However, many advantages seen with modern FCC catalyst result form improved catalyst matrix technology. In fact, several FCC matrix technology innovations over the last 29 years have led to improved gasoline yields from FCC units, improved catalyst attrition resistance, improved zeolite stability, enhanced bottoms cracking and improved metals tolerance properties of the FCC catalyst. The objective is to help refiners understand effects of different matrix technologies on FCC unit performance.

  10. 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.

  11. Matrix theory of gravitation

    E-print Network

    Wolfgang Koehler

    2011-03-23

    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 (sec. 4.1). For the standard test cases (PPN scheme, Schwarzschild-solution) no differences to the Einstein-theory are found. However, the matrix theory exhibits novel, interesting vacuum solutions.

  12. The Inquiry Matrix

    NSDL National Science Digital Library

    Julie Grady

    2010-11-01

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

  13. Learning with matrix factorizations

    E-print Network

    Srebro, Nathan, 1974-

    2004-01-01

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

  14. Clustering via matrix exponentiation

    E-print Network

    Zhou, Hanson M. (Hanson Mi), 1977-

    2004-01-01

    Given a set of n points with a matrix of pairwise similarity measures, one would like to partition the points into clusters so that similar points are together and different ones apart. We present an algorithm requiring ...

  15. Hybrid Matrix Geometric Algebra

    Microsoft Academic Search

    Garret Sobczyk; Gordon Erlebacher

    2004-01-01

    \\u000a The structures of matrix algebra and geometric algebra are completely compatible and in many ways complimentary, each having\\u000a their own advantages and disadvantages. We present a detailed study of the hybrid 2 × 2 matrix geometric algebra M(2,IG) with elements in the 8 dimensional geometric algebra IG=IG\\u000a 3 of Euclidean space. The resulting hybrid structure, isomorphic to the geometric algebra

  16. Aluminum Metal Matrix Composites

    SciTech Connect

    Hunt, Warren; Herling, Darrell R.

    2004-02-01

    Metal matrix composites comprise a relatively wide range of materials defined by the metal matrix, reinforcement type, and reinforcement geometry. In the area of the matrix, most metallic systems have been explored for use in metal matrix composites, including Al, Be, Mg, Ti, Fe, Ni, Co, and Ag. By far, the largest usage is in aluminum matrix composites. From a reinforcement perspective, the materials used are typically ceramics since they provide a very desirable combination of stiffness, strength, and relatively low density. Candidate reinforcement materials include SiC, Al2O3, B4C, TiC, TiB2, graphite, and a number of other ceramics. In addition, there has been work on metallic materials as reinforcements, notably W and steel fibers. The morphology of the reinforcement material is another variable of importance in metal matrix composites. The three major classes of reinforcement morphology are continuous fiber, chopped fiber or whisker, and particulate. Typically, the selection of the reinforcement morphology is determined by the desired property/cost combination. Generally, continuous fiber reinforced MMCs provide the highest properties in the direction of the fiber orientation but are the most expensive. Chopped fiber and whisker reinforced materials can produce significant property improvements in the plane or direction of their orientation, at somewhat lower cost. Particulates provide a comparatively more moderate but isotropic increase in properties and are typically available at the lowest cost. By adding to the three variables of metallic matrix, reinforcement material, and reinforcement morphology the further options of reinforcement volume fraction, orientation, and matrix alloy composition and heat treatment, it is apparent that there is a very wide range of available material combinations and resultant properties. This paper will focus on how MMCs have been applied in specific application areas.

  17. An MCS Matrix

    NSDL National Science Digital Library

    COMET

    2003-04-17

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

  18. BALANCED BILINEAR FORMS ON MATRIX AND MATRIX-LIKE COALGEBRAS

    E-print Network

    Beattie, Margaret

    BALANCED BILINEAR FORMS ON MATRIX AND MATRIX-LIKE COALGEBRAS M. BEATTIE AND R. ROSE Abstract. In this short note, we determine all balanced bilinear forms for a matrix coalgebra and for one type of matrix-like coalgebra. 1. Introduction and preliminaries In this note we determine all balanced bilinear forms

  19. Thermoelastic micromechanical stresses associated with a large alpha-silicon carbide grain in a polycrystalline beta-silicon carbide matrix

    NASA Technical Reports Server (NTRS)

    Li, Zhuang; Bradt, Richard C.

    1989-01-01

    The thermoelastic micromechanical stresses associated with a single large hexagonal alpha-SiC grain within a fine-grain-size cubic (3C) beta-SiC matrix were calculated. The naturally occurring residual stresses which are created during cooling from the processing temperatures and the effects of superimposed applied external stresses are both considered. A significant effect of the shape or geometry of the alpha-SiC grain is revealed, with the largest residual stresses associated with the naturally occurring tabular or platelet structure. The stresses are compared with the published strength results for these materials, which suggests that the residual stresses assume a significant role in the strength reduction that is observed.

  20. Fast methods for resumming matrix polynomials and Chebyshev matrix polynomials

    NASA Astrophysics Data System (ADS)

    Liang, WanZhen; Baer, Roi; Saravanan, Chandra; Shao, Yihan; Bell, Alexis T.; Head-Gordon, Martin

    2004-03-01

    Fast and effective algorithms are discussed for resumming matrix polynomials and Chebyshev matrix polynomials. These algorithms lead to a significant speed-up in computer time by reducing the number of matrix multiplications required to roughly twice the square root of the degree of the polynomial. A few numerical tests are presented, showing that evaluation of matrix functions via polynomial expansions can be preferable when the matrix is sparse and these fast resummation algorithms are employed.

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

    E-print Network

    Wick Haxton; Cecilia Lunardini

    2007-06-20

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

  2. 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

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    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).

  3. Superresolution by structured matrix approximation

    Microsoft Academic Search

    Ramdas Kumaresan; Arnab K. Shaw

    1988-01-01

    The bearing estimation problem is formulated as a matrix-approximation problem. The columns of a matrix X are formed by the snapshot vectors from an N-element array. The matrix X is then approximated by a matrix in the least-square sense. The rank as well as the partial structure of the space spanned by the columns of the approximated X matrix are

  4. Little IIB Matrix Model

    E-print Network

    Yoshihisa Kitazawa; Shun'ya Mizoguchi; Osamu Saito

    2006-04-06

    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^4, implying a six-dimensional spacetime. We also observe that it is due to non-gravitational 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.

  5. Complex matrix model duality

    E-print Network

    T. W. Brown

    2011-10-10

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super-Yang-Mills. 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.

  6. Spin Matrix Polynomials

    E-print Network

    Thomas L. Curtright

    2015-06-15

    Any nonsingular function of spin j matrices always reduces to a matrix polynomial of order 2j. The challenge is to find a convenient form for the coefficients of the matrix polynomial. The theory of biorthogonal systems is a useful framework to meet this challenge. Central factorial numbers play a key role in the theoretical development. Explicit polynomial coefficients for rotations expressed either as exponentials or as rational Cayley transforms are considered here. Structural features of the results are discussed and compared, and large j limits of the coefficients are examined.

  7. Complex matrix model duality

    SciTech Connect

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

    2011-04-15

    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.

  8. Biofilms: the matrix revisited

    Microsoft Academic Search

    Steven S. Branda; Åshild Vik; Lisa Friedman; Roberto Kolter

    2005-01-01

    Microbes often construct and live within surface-associ- ated 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 com- monality among biofilms is that their structural integrity critically depends upon an extracellular matrix produced by their constituent cells. Extracellular matrices might

  9. Matrix Reference Manual

    NSDL National Science Digital Library

    Brookes, Mike

    An alphabetical manual, from Abelian group to Zero matrix, that contains reference information about linear algebra and the properties of matrices, divided into the following sections: Properties; Eigenvalues; Special properties; Relations; Decompositions; Identities; Equations; Differentiation; Stochastic (statistical) properties; Signals; Examples; and Formal Algebra. The notation is based on the MATLAB software package.

  10. Probabilistic Matrix Factorization

    Microsoft Academic Search

    Ruslan Salakhutdinov; Andriy Mnih

    2007-01-01

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

  11. A novel phosphorylated glycoprotein in the shell matrix of the oyster Crassostrea nippona.

    PubMed

    Samata, Tetsuro; Ikeda, Daisuke; Kajikawa, Aya; Sato, Hideyoshi; Nogawa, Chihiro; Yamada, Daishi; Yamazaki, Ryo; Akiyama, Takahiro

    2008-06-01

    We found a novel 52 kDa matrix glycoprotein MPP1 in the shell of Crassostrea nippona that was unusually acidic and heavily phosphorylated. Deduced from the nucleotide sequence of 1.9 kb cDNA, which is likely to encode MPP1 with high probability, the primary structure of this protein shows a modular structure characterized by repeat sequences rich in Asp, Ser and Gly. The most remarkable of these is the DE-rich sequence, in which continuous repeats of Asp are interrupted by a single Cys residue. Disulfide-dependent MPP1 polymers occurring in the form of multimeric insoluble gels are estimated to contain repetitive locations of the anionic molecules of phosphates and acidic amino acids, particularly Asp. Thus, MPP1 and its polymers possess characteristic features of a charged molecule for oyster biomineralization, namely accumulation and trapping of Ca2+. In addition, MPP1 is the first organic matrix component considered to be expressed in both the foliated and prismatic layers of the molluscan shell microstructure. In vitro crystallization assays demonstrate the induction of tabular crystals with a completely different morphology from those formed spontaneously, indicating that MPP1 and its polymers are potentially the agent that controls crystal growth and shell microstructure. PMID:18459977

  12. The Matrix of Linear Mappings

    E-print Network

    Aleks Kleyn

    2010-01-27

    On the set of mappings of the given set, we define the product of mappings. If A is associative algebra, then we consider the set of matrices, whose elements are linear mappings of algebra A. In algebra of matrices of linear mappings we define the operation of product. The operation is based on the product of mappings. If the matrix a of linear mappings has an inverse matrix, then the quasideterminant of the matrix a and the inverse matrix are matrices of linear mappings. In the paper, I consider conditions when a matrix of linear mappings has inverse matrix, as well methods of solving a system of linear equations in an associative algebra.

  13. Optical shutter switching matrix

    NASA Technical Reports Server (NTRS)

    Grove, Charles H.

    1991-01-01

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

  14. Matrix string theory

    Microsoft Academic Search

    Robbert Dijkgraaf; Erik Verlinde; Herman L Verlinde

    1997-01-01

    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

  15. National Employment Matrix

    NSDL National Science Digital Library

    The US Bureau of Labor Statistics offers the National Industry-Occupation Employment Matrix. This fascinating searchable and browsable database allows users to track the employment distribution of an occupation among industries. Users can search or browse by industry or occupation. Results can be sorted by employment or projected (percent or numeric) change in employment. Data are available for over 500 occupations within 240 industries.

  16. Matrix theory of small oscillations

    Microsoft Academic Search

    L. K. Chavda

    1978-01-01

    We present a complete matrix formulation of the theory of small oscillations. Simple analytic solutions involving matrix functions are found which clearly exhibit the transients, the damping factors, the Breit-Wigner form for resonances, etc.

  17. Matrix Theory of Small Oscillations

    ERIC Educational Resources Information Center

    Chavda, L. K.

    1978-01-01

    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)

  18. Mueller matrix microscopic ellipsometer

    NASA Astrophysics Data System (ADS)

    Otsuki, Soichi; Murase, Norio; Kano, Hiroshi

    2013-09-01

    We propose a Mueller matrix ellipsometer based on imaging of the exit pupil of a microscope objective lens. The instrument had a polarizer and a rotating phase retarder on the polarizing arm and a polarizer (analyzer) on the analyzing arm. A vector F representing the optical effect from the objective lens to the detector was obtained by rotating the retarder and analyzing the CCD images taken at multiple azimuths of the retarder. Twelve elements of the Mueller matrix of the sample were determined from the four elements of the F vector. To test this method, a thin film on a cover glass was measured using an oil-immersion objective on internal reflection geometry. The refractive index and thickness of the film were well fitted to a three layer model taking into account the contributions of the objective effect. The accuracy of this system was also evaluated using matrix elements ideally equal to 0 or 1. The random error was estimated from the measured images of the F vector elements to be approximately 0.1% at maximum. The sources of the random and systematic errors inherent to this system were also discussed.

  19. Hypercube matrix computation task

    NASA Technical Reports Server (NTRS)

    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

    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).

  20. STRATIFICATION OF MATRIX PENCILS IN

    E-print Network

    Johansson, Stefan

    STRATIFICATION OF MATRIX PENCILS IN SYSTEMS AND CONTROL: THEORY AND ALGORITHMS Stefan Johansson x UNIVERSITY SWEDEN #12;#12;Stratification of Matrix Pencils in Systems and Control: Theory and Algorithms and notation, Paper I gives an introduction to stratification for orbits and bundles of matrices, matrix

  1. On the Matrix Exponential Function

    ERIC Educational Resources Information Center

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

    2006-01-01

    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.

  2. Matrix multiplication via arithmetic progressions

    Microsoft Academic Search

    Don Coppersmith; Shmuel Winograd

    1987-01-01

    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.

  3. Tabular equation of state for gold

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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).

  4. Tabular Equation of State for Gold

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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).

  5. Marine Wave Model Matrix

    NSDL National Science Digital Library

    COMET

    2006-05-16

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

  6. The gravitational S matrix

    SciTech Connect

    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

    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.

  7. Extracellular Matrix 3: Evolution of the extracellular matrix in invertebrates

    Microsoft Academic Search

    MARVIN L. TANZER

    1993-01-01

    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.

  8. Ceramic matrix and resin matrix composites: A comparison

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1987-01-01

    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.

  9. Light cone matrix product

    SciTech Connect

    Hastings, Matthew B [Los Alamos National Laboratory

    2009-01-01

    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.

  10. Epigenetics within the matrix

    PubMed Central

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

    2012-01-01

    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. PMID:22894907

  11. Recycling of aluminum matrix composites

    Microsoft Academic Search

    Yoshinori Nishida; Norihisa Izawa; Yukio Kuramasu

    1999-01-01

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

  12. Matrix Multiplication via Arithmetic Progressions

    Microsoft Academic Search

    Don Coppersmith; Shmuel Winograd

    1990-01-01

    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.

  13. Matrix vesicles in aging cartilage.

    PubMed

    Bonucci, E; Dearden, L C

    1976-02-01

    The calcification process that occurs in aging has been studied with the electron microscope in costal and tracheal cartilage of rats and in human costal cartilage. In these tissues, the early stage of the calcification process is induced and regulated by matrix vesicles in the same way as it occurs in epiphyseal cartilage, bone, and dentine. However, the spreading of inorganic substance from vesicles into the surrounding matrix is frequently impaired in aged cartilage, either because of a too low concentration of calcium ions, or because the structure of the cartilage matrix is not suitable for inorganic substance deposition. This shows that matrix vesicles have a calcium affinity and calcium-binding potentiality greater than that of other components of the cartilage matrix. Most matrix vesicles are produced by "Verdämmerung der Zellen." This degenerative process of the chondrocytes leads also to the formation of pericellular halos consisting of aggregates of amorphous substance and thin filaments. Part of the material that forms these aggregates seems to be produced by disruption of matrix vesicles. Within this disruptive material, thick collagen fibrils can be formed. Moreover, this material seems capable of inducing calcification. These findings suggest that matrix vesicles, by releasing their content into the matrix, can be involved in some way in collagen formation, and that the released material maintains the calcium affinity and calcium-binding property it has within the vesicles. PMID:1248650

  14. Matrix metalloproteinases and matrix metalloproteinase inhibitors in lung cancer

    Microsoft Academic Search

    Philip Bonomi

    2002-01-01

    Preclinical studies have provided evidence that matrix metalloproteinases (MMPs), a family of zinc-containing proteolytic enzymes, facilitate tumor invasion, the establishment of metastases, and the promotion of tumor-related angiogenesis. Matrix metalloproteinase inhibitors (MMPIs) have been shown to inhibit tumor growth and dissemination in preclinical models. Not all lung cancers express the MMPs believed to be most important in promoting the neoplastic

  15. Matrix metalloproteinase degradation of extracellular matrix: biological consequences

    Microsoft Academic Search

    Steven D Shapiro

    1998-01-01

    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

  16. Matrix Treatment of Ray Optics.

    ERIC Educational Resources Information Center

    Quon, W. Steve

    1996-01-01

    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

  17. How to Study a Matrix

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  18. NUMERICAL COMPUTATION OF MATRIX FUNCTIONS

    E-print Network

    Higham, Nicholas J.

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.2 The Matrix pth Root Function . . . . . . . . . . . . . . . . . . . . 38 2.2.1 Roots of Singular Matrices . . . . . . . . . . . . . . . . . . 44 2.3 Newton's Method for the Matrix pth Root of the Schur Method . . . . . . . . . . . . . . . . 65 2.5 Conditioning of a pth Root

  19. How to Visualize a Matrix

    ERIC Educational Resources Information Center

    Albrecht, Klaus

    1974-01-01

    A graphical method is proposed which allows one to visualize a real matrix and its inverse. In this scheme, various special properties of the matrix are easily recognized. Up to 5x5 matrices can be graphed on an average page if the range of values does not exceed two orders of magnitude. (Author/LS)

  20. Experiments on Sparse Matrix Partitioning

    Microsoft Academic Search

    S. Riyavongy

    We have undertaken experiments to determine the comparative quality of sparse matrix partition- ers. A large selection of test matrices are partitioned and then permuted so that the resulting form exhibits a block structure. This form is useful for implementing sparse matrix-vector multiplication in a parallel computing environment where each block-row strip will be assigned to a single computing node.

  1. Matrix Theory of pp Waves

    E-print Network

    Jeremy Michelson

    2004-01-08

    The Matrix Theory that has been proposed for various pp wave backgrounds is discussed. Particular emphasis is on the existence of novel nontrivial supersymmetric solutions of the Matrix Theory. These correspond to branes of various shapes (ellipsoidal, paraboloidal, and possibly hyperboloidal) that are unexpected from previous studies of branes in pp wave geometries.

  2. Hybridized polymer matrix composites

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    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.

  3. Matrix Algorithms by Dr. Amin Witno

    E-print Network

    A and the right- hand matrix B side by side. 2. Apply Gauss-Jordan algorithm to convert this matrix to its reduced] consisting of the matrix A and the identity matrix É side by side. 2. Apply Gauss-Jordan algorithm to convertMatrix Algorithms by Dr. Amin Witno There are only three elementary row operations: 1. Interchange

  4. New Chorus Diffusion Matrix

    NASA Astrophysics Data System (ADS)

    Horne, Richard B.; Kersten, Tobias; Glauert, Sarah A.; Meredith, Nigel P.; Boscher, Daniel; Sicard, Angelica; Maget, Vincent

    2013-04-01

    Whistler mode chorus waves play a major role in the loss and acceleration of electrons in the Earth's radiation belts. While high time resolution satellite data show that these waves are highly structured in frequency and time, at present their effects on the electron distribution can only be assessed on a global scale by using quasi-linear diffusion theory. Here we present new quasi-linear diffusion coefficients for upper and lower band chorus waves for use in global radiation belt models. Using data from DE 1 CRRES, Cluster 1, Double Star TC1 and THEMIS, we have constructed a database of wave properties and used this to construct new diffusion coefficients for L* = 1.5 to 10 in steps of 0.5, 10 latitude bins between 0o and 60o ,8 bins in MLT and 5 levels of geomagnetic activity as measured by Kp. We find that the peak frequency of lower band chorus is close to 0.2 fce, which is lower than that used in previous models. The combined upper and lower band chorus diffusion shows structure that should result in an energy dependent pitch angle anisotropy, particularly between 1 keV and 100 keV. The diffusion rates suggest that wave-particle interactions should still be very important outside geostationary orbit, out to at least L* = 8. We find significant energy diffusion near 1 keV near the loss cone, consistent with wave growth. By including the new chorus diffusion matrix into the BAS radiation belt (BRB) model we compare the effects on the evolution of the radiation belts against previous models.

  5. M-theoretic matrix models

    E-print Network

    Alba Grassi; Marcos Marino

    2014-11-30

    Some matrix models admit, on top of the usual 't Hooft expansion, an M-theory-like expansion, i.e. an expansion at large N but where the rest of the parameters are fixed, instead of scaling with N. These models, which we call M-theoretic matrix models, appear in the localization of Chern-Simons-matter theories, and also in two-dimensional statistical physics. Generically, their partition function receives non-perturbative corrections which are not captured by the 't Hooft expansion. In this paper, we discuss general aspects of these type of matrix integrals and we analyze in detail two different examples. The first one is the matrix model computing the partition function of N=4 supersymmetric Yang-Mills theory in three dimensions with one adjoint hypermultiplet and N_f fundamentals, which has a conjectured M-theory dual, and which we call the N_f matrix model. The second one, which we call the polymer matrix model, computes form factors of the 2d Ising model and is related to the physics of 2d polymers. In both cases we determine their exact planar limit. In the N_f matrix model, the planar free energy reproduces the expected behavior of the M-theory dual. We also study their M-theory expansion by using Fermi gas techniques, and we find non-perturbative corrections to the 't Hooft expansion.

  6. A data locality methodology for matrix–matrix multiplication algorithm

    Microsoft Academic Search

    Nicolaos Alachiotis; Vasileios I. Kelefouras; George S. Athanasiou; Harris E. Michail; Angeliki S. Kritikakou; Costas E. Goutis

    Matrix-Matrix Multiplication (MMM) is a highly important kernel in linear algebra algorithms and the performance of its implementations\\u000a depends on the memory utilization and data locality. There are MMM algorithms, such as standard, Strassen–Winograd variant,\\u000a and many recursive array layouts, such as Z-Morton or U-Morton. However, their data locality is lower than that of the proposed\\u000a methodology. Moreover, several SOA

  7. Canonical density matrix perturbation theory

    E-print Network

    Niklasson, Anders M N; Rubensson, Emanuel H; Rudberg, Elias

    2015-01-01

    Density matrix perturbation theory [Niklasson and Challacombe, Phys. Rev. Lett. 92, 193001 (2004)] is generalized to canonical (NVT) free energy ensembles in tight-binding, Hartree-Fock or Kohn-Sham density functional theory. The canonical density matrix perturbation theory can be used to calculate temperature dependent response properties from the coupled perturbed self-consistent field equations as in density functional perturbation theory. The method is well suited to take advantage of sparse matrix algebra to achieve linear scaling complexity in the computational cost as a function of system size for sufficiently large non-metallic materials and metals at high temperatures.

  8. High Temperature Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    1985-01-01

    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.

  9. Mechanotransduction and extracellular matrix homeostasis

    PubMed Central

    Humphrey, Jay D.; Dufresne, Eric R.; Schwartz, Martin A.

    2015-01-01

    Preface Soft connective tissues at steady state are yet dynamic; resident cells continually read environmental cues and respond to promote homeostasis, including maintenance of the mechanical properties of the extracellular matrix that are fundamental to cellular and tissue health. The mechanosensing process involves assessment of the mechanics of the matrix by the cells through integrins and the actomyosin cytoskeleton, and is followed by a mechano-regulation process that includes the deposition, rearrangement, or removal of matrix to maintain overall form and function. Progress toward understanding the molecular, cellular, and tissue scale effects that promote mechanical homeostasis has helped identify key questions for future research. PMID:25355505

  10. Genotype imputation via matrix completion

    PubMed Central

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

    2013-01-01

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

  11. The matrix of inspiration

    NASA Astrophysics Data System (ADS)

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

    2005-04-01

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

  12. Welcome to PRI's "Matrix Project"!

    NSDL National Science Digital Library

    2001-04-03

    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.

  13. Computational Improvements to Matrix Operations

    E-print Network

    Gordon Chalmers

    2006-01-18

    An alternative to the matrix inverse procedure is presented. Given a bit register which is arbitrarily large, the matrix inverse to an arbitrarily large matrix can be peformed in ${\\cal O}(N^2)$ operations, and to matrix multiplication on a vector in ${\\cal O}(N)$. This is in contrast to the usual ${\\cal O}(N^3)$ and ${\\cal O}(N^2)$. A finite size bit register can lead to speeds up of an order of magnitude in large matrices such as $500\\times 500$. The FFT can be improved from ${\\cal O}(N\\ln N)$ to ${\\cal O}(N)$ steps, or even fewer steps in a modified butterfly configuration.

  14. Very badly approximable matrix functions

    Microsoft Academic Search

    V. V. Peller; S. R. Treil

    2005-01-01

    .  We study in this paper very badly approximable matrix functions on the unit circle\\u000a $$ \\\\mathbb{T}, $$ i.e., matrix functions ? such that the zero function is a superoptimal approximation of ?. The purpose of this paper is to\\u000a obtain a characterization of the continuous very badly approximable functions.\\u000a \\u000a Our characterization is more geometric than algebraic characterizations earlier obtained in

  15. Universal Keplerian state transition matrix

    NASA Technical Reports Server (NTRS)

    Shepperd, S. W.

    1985-01-01

    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.

  16. Universal Keplerian state transition matrix

    NASA Astrophysics Data System (ADS)

    Shepperd, S. W.

    1985-02-01

    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.

  17. The Extracellular Matrix: An Overview

    Microsoft Academic Search

    Jeffrey H. Miner

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

  18. Hyaluronan-Dependent Pericellular Matrix

    PubMed Central

    Evanko, Stephen P.; Tammi, Markku I.; Tammi, Raija H.; Wight, Thomas N.

    2007-01-01

    Hyaluronan is a multifunctional glycosaminoglycan that forms the structural basis of the pericellular matrix. Hyaluronan is extruded directly through the plasma membrane by one of three hyaluronan synthases and anchored to the cell surface by the synthase or cell surface receptors such as CD44 or RHAMM. Aggregating proteoglycans and other hyaluronan-binding proteins, contribute to the material and biological properties of the matrix and regulate cell and tissue function. The pericellular matrix plays multiple complex roles in cell adhesion/de-adhesion, and cell shape changes associated with proliferation and locomotion. Time-lapse studies show that pericellular matrix formation facilitates cell detachment and mitotic cell rounding. Hyaluronan crosslinking occurs through various proteins, such as tenascin, TSG-6, inter-alpha-trypsin inhibitor, pentraxin and TSP-1. This creates higher order levels of structured hyaluronan that may regulate inflammation and other biological processes. Microvillous or filopodial membrane protrusions are created by active hyaluronan synthesis, and form the scaffold of hyaluronan coats in certain cells. The importance of the pericellular matrix in cellular mechanotransduction and the response to mechanical strain are also discussed. PMID:17804111

  19. Relativistic Dipole Matrix Element Zeros

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2002-05-01

    There is a special class of relativistic high energy dipole matrix element zeros (RZ), whose positions with respect to photon energy ? , only depend on the bound state l quantum number according to ?^0=mc^2/(l_b+1) (independent of primary quantum number n, nuclear charge Z, central potential V and dipole retardation). These RZ only occur in (n,l_b,j_b)arrow (? , l_b+1,j_b) transitions such as ns_1/2arrow ? p_1/2; np_3/2arrow ? d_3/2: nd_5/2arrow ? f_5/2 etc. The nonrelativistic limit of these matrix elements can be established explicitly in the Coulomb case. Within the general matrix element formalism (such as that in [1]); when |? | is substituted for ? in analytic expressions for matrix elements, the zeros remain, but ?^0 now becomes dependent on n and Z. When the reduction to nonrelativistic form is completed by application of the low energy approximation ? mc^2 mc^2, the zeros disappear. This nonzero behavior was noted in nonrelativistic dipole Coulomb matrix elements by Fano and Cooper [2] and later proven by Oh and Pratt[3]. (J. H. Scofield, Phys. Rev. A 40), 3054 (1989 (U. Fano and J. W. Cooper, Rev. Mod. Phys. 40), 441 (1968). (D. Oh and R. H. Pratt, Phys. Rev. A 34), 2486 (1986); 37, 1524 (1988); 45, 1583 (1992).

  20. Propagation of Errors for Matrix Inversion

    E-print Network

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

    1999-09-17

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

  1. Matrix Formalism of Synchrobetatron Coupling

    SciTech Connect

    Huang, Xiaobiao; /SLAC

    2006-10-06

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

  2. Instanton Counting and Matrix Model

    E-print Network

    Ta-Sheng Tai

    2007-09-07

    We construct an Imbimbo-Mukhi type matrix model, which reproduces exactly the partition function of ${\\mathbb{CP}^1}$ topological strings in the small phase space, Nekrasov's instanton counting in ${\\cal{N}}=2$ gauge theory and the large $N$ limit of the partition function in 2-dimensional Yang-Mills theory on a sphere. In addition, we propose a dual Stieltjes-Wigert type matrix model, which emerges when all-genus topological string amplitudes on certain simple toric Calabi-Yau manifolds are compared with the Imbimbo-Mukhi type model.

  3. Design with ceramic matrix composites

    SciTech Connect

    Cocks, A.C.F. [Cambridge Univ. (United Kingdom); Leckie, F.A. [Univ. of California, Santa Barbara, CA (United States)

    1995-12-01

    Ceramic composite materials offer attractive possibilities in structural design on account of their superior strength/weight ratio and their potential for high-temperature application. A drawback in their application is the relatively low value of stress to cause matrix cracking. Clearly, matrix cracking should be avoided in most of the components but in localized regions of high stress, the presence of cracks may relieve stress so that performance is not compromised. In this presentation, some early attempts to develop design procedures for CMCs are described.

  4. Strings, matrix models, and meanders

    NASA Astrophysics Data System (ADS)

    Makeenko, Y.

    1996-06-01

    I briefly review the present status of bosonic strings and discretized random surfaces in D > 1 which seem to be in a polymer rather than stringy phase. As an explicit example of what happens, I consider the Kazakov—Migdal model with a logarithmic potential which is exactly solvable for any D (at large D for an arbitrary potential). I discuss also the meander problem and report some new results on its representation via matrix models and the relation to the Kazakov—Migdal model. A supersymmetric matrix model is especially useful for describing the principal meanders.

  5. Some considerations of matrix equations using the concept of reproductivity

    E-print Network

    Malesevic, Branko

    2011-01-01

    In this paper we analyse Cline's matrix equation, generalized Penrose's matrix system and a matrix system for k-commutative {1}-inverses. We determine reproductive and non-reproductive general solutions of analysed matrix equation and analysed matrix systems.

  6. Text Mining Nonnegative Matrix Factorization

    E-print Network

    Kunkle, Tom

    Text Mining using the Nonnegative Matrix Factorization Amy Langville Carl Meyer Department: Guide D3: Child Safety at Home T4: Health D4: Your Baby's Health & Safety : From Infant to Toddler T5 Babies Collector's Guide T8: Safety T9: Toddler #12;Example from Berry's book Terms Documents T1: Bab

  7. Student Transfer Matrix, Fall 1996.

    ERIC Educational Resources Information Center

    Oklahoma State Regents for Higher Education, Oklahoma City.

    The Student Transfer Matrix provides data on the numbers of students transferring from Oklahoma public and private institutions of higher education to other Oklahoma institutions, using data from receiving institutions. Among the highlights are: the number of students who transferred to four-year and two-year institutions remained steady at 57.8…

  8. MATRIX BALANCING UNDER CONFLICTING INFORMATION

    Microsoft Academic Search

    Manfred Lenzen; Blanca Gallego; Richard Wood

    2009-01-01

    We have developed a generalised iterative scaling method (KRAS) that is able to balance and reconcile input–output tables and SAMs under conflicting external information and inconsistent constraints. Like earlier RAS variants, KRAS can: (a) handle constraints on arbitrarily sized and shaped subsets of matrix elements; (b) include reliability of the initial estimate and the external constraints; and (c) deal with

  9. Leadership Styles: A Behavioral Matrix.

    ERIC Educational Resources Information Center

    Sayers, Susan

    The workshop materials assembled in this document aim to help educators and parents build effective group processes by assessing their leadership styles, appreciating and capitalizing on their strengths, increasing their leadership effectiveness, and understanding alternative leadership styles. The author uses a behavioral matrix to categorize…

  10. Perturbation semigroup of matrix algebras

    E-print Network

    Niels Neumann; Walter D. van Suijlekom

    2014-10-22

    In this article we analyze the structure of the semigroup of inner perturbations in noncommutative geometry. This perturbation semigroup is associated to a unital associative *-algebra and extends the group of unitary elements of this *-algebra. We compute the perturbation semigroup for all matrix algebras.

  11. [Matrix Support: a bibliographical study].

    PubMed

    Iglesias, Alexandra; Avellar, Luziane Zacché

    2014-09-01

    This article presents a bibliographical review of matrix support in mental health. A search was conducted in the Virtual Health Library and the LILACS, SciELO and Google Scholar databases using the key words: "matrix support in mental health." Fourteen articles were located with the desired characteristics, which indicates that only a restricted number of publications are in circulation. The articles were analyzed with respect to their structural and methodological aspects, which revealed the absolute predominance of the use of qualitative methods and health professionals as the target research population. The same articles were then analyzed for their theoretical discussions. Among other issues, the importance of matrix support to enhance the primary health care teams provided to people suffering from psychic distress is highlighted. However, there is still considerable confusion regarding the proposal of the matrix support and shared responsibilities between teams of reference and mental health professionals, which emphasizes the need for training of these professionals, as well as better coordination and organization of the mental health care network. PMID:25184584

  12. Information & Technology Literacy Standards Matrix.

    ERIC Educational Resources Information Center

    Potter, Calvin J.; Lohr, Neah J.; Klein, Jim; Sorensen, Richard J.

    Intended to help library media specialists, technology educators, and curriculum planning teams identify where specific information and technology competencies might best fit into the assessed content areas of the curriculum, this document presents a matrix that identifies the correlation between Wisconsin's Information and Technology Literacy…

  13. Overview of the CKM Matrix

    E-print Network

    Gershon, Tim

    2012-01-01

    The current status of the determination of the elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix is reviewed. Tensions in the global fits are highlighted. Particular attention is paid to progress in, and prospects for, measurements of CP violation effects.

  14. Matrix embedding for large payloads

    Microsoft Academic Search

    Jessica J. Fridrich; David Soukal

    2006-01-01

    Matrix embedding is a previously introduced coding method that is used in steganography to improve the embedding efficiency (increase the number of bits embedded per embed- ding change). Higher embedding efficiency translates into better steganographic security. This gain is more important for long messages than for shorter ones because longer messages are in general easier to detect. In this paper,

  15. Matrix Completion from Noisy Entries

    Microsoft Academic Search

    Raghunandan H. Keshavan; Andrea Montanari; Sewoong Oh

    2009-01-01

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

  16. Matrix converters: a technology review

    Microsoft Academic Search

    Patrick W. Wheeler; José Rodríguez; Jon C. Clare; Lee Empringham; Alejandro Weinstein

    2002-01-01

    The matrix converter is an array of controlled semiconductor switches that connects directly the three-phase source to the three-phase load. This converter has several attractive features that have been investigated in the last two decades. In the last few years, an increase in research work has been observed, bringing this topology closer to the industrial application. This paper presents the

  17. Matrix Turnover: Mechanisms and Common Denominators 665 Three-dimensional extracellular matrix culture

    E-print Network

    Kenny, Paraic

    matrix culture, tumour necrosis factor (TNF), tumour necrosis factor -converting enzyme (TACEMatrix Turnover: Mechanisms and Common Denominators 665 Three-dimensional extracellular matrix.S.A. Abstract Three-dimensional extracellular matrix culture, on substrata such as Matrigel, restores many

  18. On a quadratic matrix equation associated with an M-matrix

    Microsoft Academic Search

    Chun-hua Guo

    2003-01-01

    We study the quadratic matrix equation X, EX F = 0, where E is diagonal and F is an M-matrix. Quadratic matrix equations of this type arise in noisy Wiener{Hopf problems for Markov chains. The solution of practical interest is a particular M-matrix solution. The existence and uniqueness of M-matrix solutions and numerical methods for nding the desired M-matrix solution

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

    E-print Network

    Reticker-Flynn, Nathan E.

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

  20. Interstellar problems and matrix solutions

    NASA Technical Reports Server (NTRS)

    Allamandola, Louis J.

    1987-01-01

    The application of the matrix isolation technique to interstellar problems is described. Following a brief discussion of the interstellar medium (ISM), three areas are reviewed in which matrix experiments are particularly well suited to contribute the information which is sorely needed to further understanding of the ISM. The first involves the measurement of the spectroscopic properties of reactive species. The second is the determination of reaction rates and the elucidation of reaction pathways involving atoms, radicals, and ions which are likely to interact on grain surfaces and in grain mantles. The third entails the determiantion of the spectroscopic, photochemical, and photophysical properties of interstellar and cometary ice analogs. Significant, but limited, progress has been made in these three areas, and a tremendous amount of work is required to fully address the variety of unique chemical and spectroscopic questions posed by the astronomical observations.

  1. Corrosion of Titanium Matrix Composites

    SciTech Connect

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

    2002-09-22

    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.

  2. Simplicial matrix-tree theorems

    E-print Network

    Duval, Art M; Martin, Jeremy L

    2008-01-01

    We generalize the definition and enumeration of spanning trees from the setting of graphs to that of arbitrary-dimensional simplicial complexes $\\Delta$, extending an idea due to G. Kalai. We prove a simplicial version of the Matrix-Tree Theorem that counts simplicial spanning trees, weighted by the squares of the orders of their top-dimensional integral homology groups, in terms of the Laplacian matrix of $\\Delta$. As in the graphic case, one can obtain a more finely weighted generating function for simplicial spanning trees by assigning an indeterminate to each vertex of $\\Delta$ and replacing the entries of the Laplacian with Laurent monomials. When $\\Delta$ is a shifted complex, we give a combinatorial interpretation of the eigenvalues of its weighted Laplacian and prove that they determine its set of faces uniquely, generalizing known results about threshold graphs and unweighted Laplacian eigenvalues of shifted complexes.

  3. Mueller matrix roots depolarization parameters.

    PubMed

    Noble, Hannah D; McClain, Stephen C; Chipman, Russell A

    2012-02-20

    The Mueller matrix roots decomposition recently proposed by Chipman in [1] and its three associated families of depolarization (amplitude depolarization, phase depolarization, and diagonal depolarization) are explored. Degree of polarization maps are used to differentiate among the three families and demonstrate the unity between phase and diagonal depolarization, while amplitude depolarization remains a distinct class. Three families of depolarization are generated via the averaging of different forms of two nondepolarizing Mueller matrices. The orientation of the resulting depolarization follows the cyclic permutations of the Pauli spin matrices. The depolarization forms of Mueller matrices from two scattering measurements are analyzed with the matrix roots decomposition-a sample of ground glass and a graphite and wood pencil tip. PMID:22358163

  4. Extracellular Matrix Production by Osteoblasts

    NASA Technical Reports Server (NTRS)

    Globus, Ruth

    2003-01-01

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

  5. On fault tolerant matrix decomposition

    Microsoft Academic Search

    Patrick Fitzpatrick

    1994-01-01

    We present a fault tolerant algorithm for matrix factorization in the presence of multiple hardware faults which can be used for solving the linear systemAx=b without determining the correctZU decomposition ofA. HereZ is eitherL for ordinary Gaussian decomposition with partial pivoting,X for pairwise or neighbor pivoting (motivated by the Gentleman-Kung systolic array structure), orQ for the usualQR decomposition. Our algorithm

  6. Radiation resistant ceramic matrix composites

    Microsoft Academic Search

    R. H. Jones; D. Steiner; H. L. Heinisch; G. A. Newsome; H. M. Kerch

    1997-01-01

    Ceramic matrix composites are of interest for nuclear applications because of their high-temperature properties, corrosion resistance, fracture toughness relative to monolithic ceramics, and low neutron activation and after heat. Evaluations of the radiation resistance of commercially available SiC\\/SiC composites have revealed their promise for this application, but also the need for further development to achieve the desired performance. This paper

  7. The asymmetric ABAB matrix model

    NASA Astrophysics Data System (ADS)

    Zinn-Justin, P.

    2003-12-01

    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.

  8. Staggered chiral random matrix theory

    E-print Network

    James C. Osborn

    2011-06-02

    We present a random matrix theory (RMT) for the staggered lattice QCD Dirac operator. The staggered RMT 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.

  9. Tough high performance composite matrix

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  10. Nuclear matrix elements for double beta decay

    E-print Network

    Vadim Rodin

    2009-10-30

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

  11. Topics in Matrix Sampling Algorithms

    E-print Network

    Boutsidis, Christos

    2011-01-01

    We study three fundamental problems of Linear Algebra, lying in the heart of various Machine Learning applications, namely: 1)"Low-rank Column-based Matrix Approximation". We are given a matrix A and a target rank k. The goal is to select a subset of columns of A and, by using only these columns, compute a rank k approximation to A that is as good as the rank k approximation that would have been obtained by using all the columns; 2) "Coreset Construction in Least-Squares Regression". We are given a matrix A and a vector b. Consider the (over-constrained) least-squares problem of minimizing ||Ax-b||, over all vectors x in D. The domain D represents the constraints on the solution and can be arbitrary. The goal is to select a subset of the rows of A and b and, by using only these rows, find a solution vector that is as good as the solution vector that would have been obtained by using all the rows; 3) "Feature Selection in K-means Clustering". We are given a set of points described with respect to a large numbe...

  12. Zero asymptotic behaviour for orthogonal matrix polynomials

    Microsoft Academic Search

    A. J. Duran; P. Lopez-Rodriguez; E. B. Saff

    1999-01-01

    Weak-star asymptotic results are obtained for the zeros of orthogonal matrix polynomials (i.e., the zeros of their determinants)\\u000a on ? from two different assumptions: first from the convergence of matrix coefficients occurring in the three-term recurrence\\u000a for these polynomials; and, second, from conditions on the generating matrix measure. The matrix analogues of the Chebyshev\\u000a polynomials of the first kind are

  13. Improved Polynomial Matrix Determinant Computation \\Lambda

    E-print Network

    Henrion, Didier

    Improved Polynomial Matrix Determinant Computation \\Lambda Didier Henrion yz Michael Ÿ Sebek x of the determinant of a polynomial matrix using numerically reliable techniques. This allows for accurate determinant zeroing and determinant interpolation, thus improving existing numerical methods for polynomial matrix

  14. Metal-matrix composites: Status and prospects

    NASA Technical Reports Server (NTRS)

    1974-01-01

    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.

  15. Fast sparse matrix multiplication Raphael Yuster

    E-print Network

    Yuster, Raphael

    Fast sparse matrix multiplication Raphael Yuster Uri Zwick Abstract Let A and B two n Ã? n.e., multiplications, additions and subtractions) over R. The naive matrix multiplication algorithm, on the other hand faster than the best known matrix multiplication algorithm for dense matrices which uses O(n2

  16. LAB ASSIGNMENT -6 MATRIX OPERATIONS IN EXCEL

    E-print Network

    Clement, Prabhakar

    1 LAB ASSIGNMENT -6 MATRIX OPERATIONS IN EXCEL 8.1 ARRAYS IN EXCEL: Excel uses arrays to store the arrays for matrix operations in Excel but this helps in keeping the spreadsheet organized and easy described above. Figure 8.2 Matrix addition using array math in excel In the above example, A and B are both

  17. THE MATRIX CUBE PROBLEM: Approximations and Applications

    E-print Network

    Nemirovski, Arkadi

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

  18. Matrix-Vector and Matrix-Matrix Operations Prototype name: FLA_XXYY

    E-print Network

    Batory, Don

    or op( A ) on the left or on the right of B ) Constants (can be used for parameters alpha or beta) -1-VECTOR OPERATIONS FLA_Dot ( x, y, delta ) xT y FLA_Dot_x ( alpha, x, y, beta, delta ) xT y + FLA_Nrm2 ( x | ) MATRIX-VECTOR OPERATIONS FLA_Gemv ( trans, alpha, A, x, beta, y ) y A x + y, y AT x + y, y AH x + y

  19. Reduction to Versal Deformations of Matrix Pencils and Matrix Pairs with Application to Control Theory

    Microsoft Academic Search

    M. I. García-Planas; A. A. Mailybaev

    2003-01-01

    Matrix pencils under the strict equivalence and matrix pairs under the state feedback equivalence are considered. It is known that a matrix pencil (or a matrix pair) smoothly dependent on parameters can be reduced locally to a special typically more simple form, called the versal deformation, by a smooth change of parameters and a strict equivalence (or feedback equivalence) transformation.

  20. The Theory of Quaternion Matrix Derivatives

    NASA Astrophysics Data System (ADS)

    Xu, Dongpo; Mandic, Danilo P.

    2015-03-01

    A systematic theory is introduced for calculating the derivatives of quaternion matrix function with respect to quaternion matrix variables. The proposed methodology is equipped with the matrix product rule and chain rule and it is able to handle both analytic and nonanalytic functions. This corrects a flaw in the existing methods, that is, the incorrect use of the traditional product rule. In the framework introduced, the derivatives of quaternion matrix functions can be calculated directly without the differential of this function. Key results are summarized in tables. Several examples show how the quaternion matrix derivatives can be used as an important tool for solving problems related to signal processing.

  1. Cache-Oblivious Sparse Matrix--Vector Multiplication by Using Sparse Matrix Partitioning Methods

    Microsoft Academic Search

    A. N. Yzelman; Rob H. Bisseling

    2009-01-01

    In this article, we introduce a cache-oblivious method for sparse matrix-vector multiplication. Our method attempts to permute the rows and columns of the input matrix using a recursive hypergraph-based sparse matrix partitioning scheme so that the resulting matrix induces cache-friendly behaviour during sparse matrix- vector multiplication. Matrices are assumed to be stored in row-major format, by means of the compressed

  2. Physical controls on matrix mineralization

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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. 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. Authors would like to acknowledge grant no. DK61673 from the National Institutes of Health. Theoretical analysis was supported by Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy under Contract no. DE-AC02-05CH1123.

  3. Regenerator matrix physical property data

    NASA Technical Reports Server (NTRS)

    Fucinari, C. A.

    1980-01-01

    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.

  4. Ideals of generalized matrix rings

    SciTech Connect

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

    2011-01-31

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

  5. Matrix models on large graphs

    NASA Astrophysics Data System (ADS)

    Wexler, Mark

    1993-12-01

    We consider the spherical limit of multi-matrix models on regular target graphs, for instance single or multiple Potts models, or lattices of arbitrary dimension. We show, to all orders in the low temperature expansion, that when the degree of the target graph ? ? ?, the free energy becomes independent of the target graph, up to simple transformations of the matter coupling constant. Furthermore, this universal free energy contains contributions only from those surfaces which are made up of "baby universes" glued together into trees, all non-universal and non-tree contributions being suppressed by inverse powers of ?. Each order of the free energy is put into a simple, algebraic form.

  6. INTRODUCTION Chondrocytes maintain the integrity of the extracellular matrix

    E-print Network

    Buschmann, Michael

    INTRODUCTION Chondrocytes maintain the integrity of the extracellular matrix (ECM) of articular in the extracellular matrix, with the pericellular matrix associated with the most rapid rates of proteoglycan cartilage by mediating the synthesis, secretion, and degradation of matrix proteoglycans (PGs

  7. Characterization of Metal Matrix Composites

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  8. Data Parallelism and Matrix Multiplication 1 Data Parallelism

    E-print Network

    Verschelde, Jan

    Data Parallelism and Matrix Multiplication 1 Data Parallelism matrix-matrix multiplication CUDA program structure 2 Code for Matrix-Matrix Multiplication linear address system for 2-dimensional array Verschelde, 31 March 2014 Introduction to Supercomputing (MCS 572) Data Parallelism & Matrix Multiplication L

  9. Lecture 12: Chain Matrix Multiplication CLRS Section 15.2

    E-print Network

    Wu, Dekai

    Lecture 12: Chain Matrix Multiplication CLRS Section 15.2 Outline of this Lecture Recalling matrix multiplication. The chain matrix multiplication problem. A dynamic programming algorithm for chain ma- trix multiplication. 1 #12;Recalling Matrix Multiplication Matrix: An ¡ ¢ matrix

  10. Convex nonnegative matrix factorization with manifold regularization.

    PubMed

    Hu, Wenjun; Choi, Kup-Sze; Wang, Peiliang; Jiang, Yunliang; Wang, Shitong

    2015-03-01

    Nonnegative Matrix Factorization (NMF) has been extensively applied in many areas, including computer vision, pattern recognition, text mining, and signal processing. However, nonnegative entries are usually required for the data matrix in NMF, which limits its application. Besides, while the basis and encoding vectors obtained by NMF can represent the original data in low dimension, the representations do not always reflect the intrinsic geometric structure embedded in the data. Motivated by manifold learning and Convex NMF (CNMF), we propose a novel matrix factorization method called Graph Regularized and Convex Nonnegative Matrix Factorization (GCNMF) by introducing a graph regularized term into CNMF. The proposed matrix factorization technique not only inherits the intrinsic low-dimensional manifold structure, but also allows the processing of mixed-sign data matrix. Clustering experiments on nonnegative and mixed-sign real-world data sets are conducted to demonstrate the effectiveness of the proposed method. PMID:25523040

  11. Riemann--Hilbert problems, matrix orthogonal polynomials and discrete matrix equations with singularity confinement

    E-print Network

    Giovanni A. Cassatella-Contra; Manuel Manas

    2011-05-31

    In this paper matrix orthogonal polynomials in the real line are described in terms of a Riemann--Hilbert problem. This approach provides an easy derivation of discrete equations for the corresponding matrix recursion coefficients. The discrete equation is explicitly derived in the matrix Freud case, associated with matrix quartic potentials. It is shown that, when the initial condition and the measure are simultaneously triangularizable, this matrix discrete equation possesses the singularity confinement property, independently if the solution under consideration is given by recursion coefficients to quartic Freud matrix orthogonal polynomials or not.

  12. Lymphocyte interactions with extracellular matrix

    Microsoft Academic Search

    Yoji Shimizu; Stephen Shaw

    ABSTRACT To mediate an immune response, lympho- cytes must,be able to interact with,and,respond,to the sur- rounding,extracellular,environment.,In addition,to cell surface,molecules,that facilitate adhesion,of lymphocytes to other cells, recent studies have demonstrated that lym- phocytes,interact with,glycoproteins,and,glycosaminogly- cans,that,are,major,components,of,the,extracellular matrix,(ECM). Although many,receptors,mediating,the effects of ECM components,on,lymphocyte,function,re- main poorly defined, a number of lymphocyte ECM receptors,have,recently,been,identified;,these,include members,of the integrin,family,of adhesion,molecules,as well as structurally unrelated,molecules,such as CD44

  13. Light-cone matrix product

    NASA Astrophysics Data System (ADS)

    Hastings, M. B.

    2009-09-01

    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 ? =0.5, we simulate to a time of ?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.

  14. Thermoplastic matrix composite processing model

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  15. Light-cone matrix product

    SciTech Connect

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

    2009-09-15

    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.

  16. Solitons and giants in matrix models

    Microsoft Academic Search

    Ivan Andric; Larisa Jonke; Danijel Jurman

    2006-01-01

    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

  17. Dirac oscillators and the relativistic R matrix

    SciTech Connect

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

    2009-10-15

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

  18. Shock Waves and Cosmological Matrix Models

    E-print Network

    Miao Li; Wei Song

    2005-10-24

    We find the shock wave solutions in a class of cosmological backgrounds with a null singularity, each of these backgrounds admits a matrix description. A shock wave solution breaks all supersymmetry meanwhile indicates that the interaction between two static D0-branes cancel, thus provides basic evidence for the matrix description. The probe action of a D0-brane in the background of another suggests that the usual perturbative expansion of matrix model breaks down.

  19. Regularized Matrix Computations Andrew E. Yagle

    E-print Network

    Yagle, Andrew E.

    decomposition (SVD) of any (M × N) matrix A is A = USV H UH U = I U is M × M V H V = I V is N × N 1 . . . N SH UH )(USV H ) = V (SH S)V H (AAH )ui = 2 i ui and (AH A)vi = 2 i vi (2) · U is the matrix of eigenvectors for AAH ; · V is the matrix of eigenvectors for AH A; · This is why A = USV H instead of A = USV

  20. Matrix Bases for Star Products: a Review

    E-print Network

    Fedele Lizzi; Patrizia Vitale

    2014-08-15

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

  1. How to mix a density matrix

    SciTech Connect

    Bengtsson, Ingemar; Ericsson, Aasa [SCFAB, Fysikum, Stockholm University, S-106 91 Stockholm (Sweden)

    2003-01-01

    A given density matrix may be represented in many ways as a mixture of pure states. We show how any density matrix may be realized as a uniform ensemble. It has been conjectured that one may realize all probability distributions that are majorized by the vector of eigenvalues of the density matrix. We show that if the states in the ensemble are assumed to be distinct then this is not true, but a marginally weaker statement may still be true.

  2. Multiscale Modeling of Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Mital, Subodh K.; Pineda, Evan J.; Arnold, Steven M.

    2015-01-01

    Results of multiscale modeling simulations of the nonlinear response of SiC/SiC ceramic matrix composites are reported, wherein the microstructure of the ceramic matrix is captured. This micro scale architecture, which contains free Si material as well as the SiC ceramic, is responsible for residual stresses that play an important role in the subsequent thermo-mechanical behavior of the SiC/SiC composite. Using the novel Multiscale Generalized Method of Cells recursive micromechanics theory, the microstructure of the matrix, as well as the microstructure of the composite (fiber and matrix) can be captured.

  3. Finding Nonoverlapping Substructures of a Sparse Matrix

    SciTech Connect

    Pinar, Ali; Vassilevska, Virginia

    2005-08-11

    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.

  4. Integrated-optical approaches to matrix multiplication

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  5. Third Intermetallic Matrix Composites Symposium, volume 350

    SciTech Connect

    Graves, J.A.; Bowman, R.R.; Lewandowski, J.J.

    1994-04-01

    Partial contents include: issues in potential IMC application for aerospace structures; powder metallurgy processing of intermetallic matrix composites; microstructure and properties of intermetallic matrix composites produced by reaction synthesis; combustion synthesis of niobium aluminide matrix composites; ambient temperature synthesis of bulk intermetallics; wear behavior of SHS intermetallic matrix composites; fracture characteristics of metal-intermetallic laminates produced by SHS reactions; and vapor phase synthesis of Ti aluminides and the interfacial bonding effect on the mechanical property of micro-composites reinforced by pyrolized SiC fibers.

  6. Transferring elements of a density matrix

    E-print Network

    Armen E. Allahverdyan; Karen V. Hovhannisyan

    2010-07-08

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

  7. The Geometry of Jordan Matrix Models

    E-print Network

    Michael Rios

    2005-07-15

    We elucidate the geometry of matrix models based on simple formally real Jordan algebras. Such Jordan algebras give rise to a nonassociative geometry that is a generalization of Lorentzian geometry. We emphasize constructions for the exceptional Jordan algebra and the exceptional Jordan C*-algebra and describe the projective spaces related to the exceptional cubic matrix model and the E_6 matrix model. The resulting projective spaces are shown to be exceptional versions of projective twistor space, thus revealing the existence of exceptional twistor string theories that are dual to octonionic matrix models.

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

    E-print Network

    Saraswat, Jyoti

    2009-06-11

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

  9. The first matrix cracking behavior of fiber-reinforced ceramic matrix composites

    SciTech Connect

    Kumaria, S.; Kumar, S.; Singh, R.N. [Univ. of Cincinnati, OH (United States). Dept. of Materials Science and Engineering] [Univ. of Cincinnati, OH (United States). Dept. of Materials Science and Engineering

    1997-12-01

    First matrix cracking stress in fiber reinforced ceramic composites is an important design parameter as it signifies the onset of mechanical damage and subsequent degradation of fiber and interface properties due to oxidation and corrosion. In this study, the influence of variation in the matrix crack length and fiber volume fraction on the first matrix cracking stress of ceramic matrix composites is investigated. To this end, zircon matrix composites uniaxially reinforced with silicon carbide fibers and monolithic zircon were fabricated. The monolithic and composite samples were microindented to create flaws of controlled size on the surface, and were then tested in 3-point flexure to obtain the matrix cracking stress. The results obtained from this study clearly indicated the non-steady state (short crack) and steady state (long crack) matrix cracking behaviors in ceramic matrix composites. The experimental results are compared with the theoretical results based on the fracture mechanics analyses published previously.

  10. Transverse yielding and matrix flow past the fibers in metal matrix composites

    Microsoft Academic Search

    Z.-Z. Du; R. M. McMeeking; S. Schmauder

    1995-01-01

    This paper examines the plastic flow in transverse loading of metal matrix composites reinforced with well bonded continuous fibers when stress gradients are developed so that the matrix not only yields but also flows past the fibers. The fibers are stationary due to elastic constraint as would occur, for example, in a circumferentially reinforced ring. The matrix is elastic perfectly

  11. Every invertible matrix is diagonally equivalent to a matrix with distinct eigenvalues

    E-print Network

    Li, Chi-Kwong

    Every invertible matrix is diagonally equivalent to a matrix with distinct eigenvalues Man-Duen Choi , Zejun Huang , Chi-Kwong Li , and Nung-Sing Sze§ Abstract We show that for every invertible n�n complex matrix A there is an n�n diagonal invertible D such that AD has distinct eigenvalues. Using

  12. Recombinant Fibronectin Matrix Mimetics Specify Integrin Adhesion and Extracellular Matrix Assembly

    E-print Network

    Goldman, Steven A.

    Recombinant Fibronectin Matrix Mimetics Specify Integrin Adhesion and Extracellular Matrix Assembly-establishment of a functional extracellular matrix (ECM), is a challenge currently facing this field. During tissue repair, fibronectin is converted from an inactive soluble form into biologically active ECM fibrils through a cell

  13. CYCLIC REPRESENTATIONS OF THE QUANTUM MATRIX ALGEBRAS

    E-print Network

    Jakobsen, Hans Plesner

    ­called Dipper­Donkin quantum matrix algebra as well as of two other natural quantized matrix algebras. The cyclic representations of the quantum enveloping algebra U q (g) at a root of unity have been studied of functions on the quantized SL(n), roughly speaking by setting the quantum determinant equal to 1. Thus

  14. Proteinases and myocardial extracellular matrix turnover

    Microsoft Academic Search

    Suresh C. Tyagi

    1997-01-01

    Extracellular structural remodeling is the compensatory response of the tissue following pathological stage. Myocardial infarction, which leads to adverse remodeling, thinning of the ventricle wall, dilatation and heart failure, is one of the leading causes of death. Remodeling implies an alteration in the extracellular matrix and in the spatial orientation of cells and intracellular components. The extracellular matrix is responsible

  15. Matrix string theory and its moduli space

    Microsoft Academic Search

    G. Bonelli; L. Bonora; F. Nesti; A. Tomasiello

    1999-01-01

    The correspondence between Matrix String Theory in the strong coupling limit and IIA superstring theory can be shown by means of the instanton solutions of the former. We construct the general instanton solutions of Matrix String Theory which interpolate between given initial and final string configurations. Each instanton is characterized by a Riemann surface of genus h with n punctures,

  16. Holographic geometry and noise in matrix theory

    Microsoft Academic Search

    Craig J. Hogan; Mark G. Jackson

    2009-01-01

    Using matrix theory as a concrete example of a fundamental holographic theory, we show that the emergent macroscopic spacetime displays a new macroscopic quantum structure, holographic geometry, and a new observable phenomenon, holographic noise, with phenomenology similar to that previously derived on the basis of a quasimonochromatic wave theory. Traces of matrix operators on a light sheet with a compact

  17. Parallel algorithms for matrix normal forms

    Microsoft Academic Search

    Erich Kaltofen; M. s. Krishnamoorthy; B. David Saunders

    1990-01-01

    Here we offer a new randomized parallel algorithm that determines the Smith normalform of a matrix with entries being univariate polynomials with coefficients in an arbitraryfield. The algorithm has two important advantages over our previous one: the multipliersrelating the Smith form to the input matrix are computed, and the algorithm is probabilistic ofLas Vegas type, i.e., always finds the correct

  18. Learning the Kernel Matrix with Semidefinite Programming

    Microsoft Academic Search

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

    2004-01-01

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

  19. The university of Florida sparse matrix collection

    Microsoft Academic Search

    Timothy A. Davis; Yifan Hu

    2011-01-01

    We describe the University of Florida Sparse Matrix Collection, a large and actively growing set of sparse matrices that arise in real applications. The Collection is widely used by the numerical linear algebra community for the development and performance evaluation of sparse matrix algorithms. It allows for robust and repeatable experiments: robust because performance results with artificially generated matrices can

  20. Trimmed linearizations for structured matrix polynomials

    Microsoft Academic Search

    Ralph Byers; Volker Mehrmann; Hongguo Xu

    2008-01-01

    We discuss the eigenvalue problem for general and structured matrix polynomials which may be singular and may have eigenvalues at infinity. We derive condensed forms that allow (partial) deflation of the infinite eigenvalue and singular structure of the matrix polynomial. The remaining reduced order staircase form leads to new types of linearizations which determine the finite eigenvalues and corresponding eigenvectors.

  1. Bootstrapping Heteroskedasticity Consistent Covariance Matrix Estimator

    E-print Network

    Paris-Sud XI, Université de

    Bootstrapping Heteroskedasticity Consistent Covariance Matrix Estimator by Emmanuel Flachaire robust covariance matrix estima- tor. In this paper, we show that the wild bootstrap estimator can- sults seem to conflict with those of MacKinnon and White (1985); we reconcile these two results. JEL

  2. Recursive Array Layouts and Fast Matrix Multiplication

    Microsoft Academic Search

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

    2002-01-01

    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

  3. Matrix model description of baryonic deformations

    SciTech Connect

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

    2003-03-13

    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.

  4. Weak matrix elements for CP violation.

    SciTech Connect

    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

    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.

  5. Renewal Credit Matrix CERTIFICATE RENEWAL PLAN

    E-print Network

    Kunkle, Tom

    Renewal Credit Matrix CERTIFICATE RENEWAL PLAN PROFESSIONAL DEVELOPMENT OPTIONS FOR SOUTH CAROLINA are restricted to Options 1 and 2 in the matrix. CERTIFICATE RENEWAL OPTION ELIGIBILITY CRITERIA RENEWAL CREDITS to 120 renewal credits may be earned via this option during the five-year validity period

  6. Distributed bearing estimation via matrix completion

    Microsoft Academic Search

    Andrew Waters; Volkan Cevher

    2010-01-01

    We consider bearing estimation of multiple narrow-band plane waves impinging on an array of sensors. For this problem, bearing estimation algorithms such as minimum variance distortionless response (MVDR), multiple signal classification, and maximum likelihood generally require the array covariance matrix as sufficient statistics. Interestingly, the rank of the array covariance matrix is approximately equal to the number of the sources,

  7. A Matrix Approach to Position Classification

    ERIC Educational Resources Information Center

    Wilkinson, John; And Others

    1975-01-01

    A classification system for librarians at the University of Western Ontario has four general and five ranking factors in position classification. A matrix was developed using these factors on a vertical axis and the desired number of positions on a horizontal axis. Existing professional positions were analyzed in terms of the matrix. (Author/LS)

  8. Nonpolynomial Matrix Models in String Theory.

    NASA Astrophysics Data System (ADS)

    Olczyk, Thaddeus L.

    In this thesis various aspects of matrix models with nonpolynomial terms is investigated. It is demonstrated that additions of reciprocal terms to a one matrix model have no effect. It is further demonstrated that the Penner model and the Kazakov model are fixed points of renormalization group flows.

  9. Accelerated aging of metal-matrix composites

    Microsoft Academic Search

    Dutta

    1988-01-01

    Accelerated aging of Metal Matrix Composites (MMCs) with precipitation-hardening matrices has often been attributed to an increase in the dislocation density in the immediate vicinity of the reinforcement. The plastic zone is generated due to differential thermal contraction of the matrix and the reinforcement during cooling from the solutionizing temperature. A finite-element approach was used here to model the geometry

  10. Mondriaan distribution Mondriaan Sparse Matrix Distribution

    E-print Network

    Sleijpen, Gerard

    Mondriaan distribution Mondriaan Sparse Matrix Distribution (PSC §4.5) 1 / 25 #12;Mondriaan, communicate, compute 2 / 25 #12;Mondriaan distribution Cartesian matrix partitioning Block distribution of 59 processor: 126, 28, 128, 30 Each separate split has optimal balance (for blocks) 3 / 25 #12;Mondriaan

  11. A calcium fortified viral matrix protein

    PubMed Central

    Amarasinghe, Gaya K.; Dutch, Rebecca Ellis

    2014-01-01

    Summary In this issue of Structure, Leyrat and colleagues provide the first structural analysis of the HMPV matrix protein, a key regulator of viral assembly. Though structurally similar to other matrix proteins, two calcium binding sites suggest intriguing differences in regulation. PMID:24411575

  12. MATRIX INTEGRALS AND INTEGRABLE SYSTEMS Motohico Mulase

    E-print Network

    Mulase, Motohico

    MATRIX INTEGRALS AND INTEGRABLE SYSTEMS by Motohico Mulase Department of Mathematics University of California, Davis Davis, CA 95616 momulase@ucdavis.edu 1. Hermitian matrix integrals. Let Hn be the spaceX the usual Lebesgue measure on Hn. The unitary group U(n) acts on this space by conjugation. We call

  13. FOCUS: MALDI Exploring Infrared Wavelength Matrix-

    E-print Network

    Chait, Brian T.

    FOCUS: MALDI Exploring Infrared Wavelength Matrix- Assisted Laser Desorption/Ionization of Proteins) to infrared-wavelength matrix-assisted time-of-flight mass spectrometry (IR-MALDI-TOF-MS) of proteins. The shapes of the spectral peaks obtained with DE-IR-MALDI-MS are compared with those obtained from the same

  14. Cabbibo Angle Approximation of the CKM Matrix

    NASA Astrophysics Data System (ADS)

    Dannon, Vic

    1999-10-01

    (1) The Wolfenstein approximation for the CKM matrix is constrained by theory to be real, and an inaccurate measure of CP violation. (2)The matrix [matrix\\cos ? C & sin ? C & sin ^4? _C?-sin ? _C\\cos ? _C^2 & \\cos ? _C\\cos ? _C^2 & sin ^2? _C?sin ^3? C & -sin ^2? _C\\cos ? C & \\cos ? _C^2] is a very good approximation to the real part of the CKM matrix. (3) This approximation is equivalent to assuming, sin ? _2? sin ^2? C and, , sin ? _3? sin ^3? C where the CKM matrix is the product of four rotation matrices, based on four mixing angles, ? _1, ? _2, ? _3, and ? , [matrix1 & 0 & 0 ?0 & c2 & s2 ?0 & -s2 & c_2][matrixc1 & s1 & 0 ?-s1 & c1 & 0 ?0 & 0 & 1][matrix1 &0 & 0 ?0 & 1 & 0 ?0 & 0 & exp i? ][matrix1 & 0 & 0 ?0 & c3 & s3 ?0 & s3 & c_3], and where c_i=\\cos ? _i, and s_i=sin ? _i. (4) The Wolfenstein approximation real part, reduces to our approximation for ? ? sin ? _C\\over 1+sin ? C and A? 1+sin ? _C. For sin ? _C? 0.23, ? ? 0.187 and A? 1.23.

  15. A new generalized direct matrix converter

    Microsoft Academic Search

    S. H. Hosseini; E. Babaei

    2001-01-01

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

  16. A zero switching loss matrix converter

    Microsoft Academic Search

    Ching-Tsai Pan; Tsung-Cheng Chen; Jenn-Jong Shieh

    1993-01-01

    A low loss bidirectional switch set is proposed for a matrix power converter. The proposed switch is able to turn on at zero current and turn off at zero voltage to achieve almost zero loss and soft switching. Hence, a simple hysteretic current control can now be applied directly to a matrix power converter without adding any additional snubber circuit

  17. New control strategy for matrix converter

    Microsoft Academic Search

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

    1989-01-01

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

  18. Silicon carbide matrix for fuel cells

    Microsoft Academic Search

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

    1987-01-01

    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

  19. A matrix analysis of conjugate gradient algorithms

    SciTech Connect

    Ashby, S.F. [Lawrence Livermore National Lab., CA (United States); Gutknecht, M.H. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1993-04-01

    This paper explores the relationships between the conjugate gradient algorithms Orthodir, Orthomin, and Orthores. To facilitate this exploration, a matrix formulation for each algorithm is given. It is shown that Orthodir directly computes a Hessenberg matrix H{sub k} at step k. Orthores also computes a Hessenberg matrix, G{sub k}, which is similar to a Hessenberg matrix obtained from H{sub k} by perturbing its last column. (This perturbation vanishes at convergence.) Orthomin, on the other hand, computes a UL and LU factorization of the perturbed H{sub k} and G{sub k}, respectively. The breakdown of Orthomin and Orthores are interpreted in terms of these underlying matrix factorizations. A connection with Lanczos algorithms is also examined, as is the special case of B-normal(1) matrices (for which efficient three-term CG algorithms exist).

  20. Adaptive wavelet methods - Matrix-vector multiplication

    NASA Astrophysics Data System (ADS)

    ?erná, Dana; Fin?k, Václav

    2012-12-01

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

  1. Graphical evaluation of relativistic matrix elements

    NASA Technical Reports Server (NTRS)

    Huang, K. N.

    1978-01-01

    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.

  2. Historical perspective of matrix metalloproteases.

    PubMed

    Pulkoski-Gross, Ashleigh E

    2015-01-01

    Matrix metalloproteinases (MMPs) were identified as early as 1962. Since this seminal finding, this family of zinc-dependent endopeptidases has been studied extensively. This collective work has resulted in delineation of MMP gene and protein structures, the mechanisms of control of MMPs, the action of MMPs on both extracellular matrices and other proteins such as growth factors and cytokines, naturally-occurring mechanisms of control, and of course their role in normal physiology and their crucial roles in pathophysiology. Stemming from the discovery that MMPs contribute to arthritis, heart disease, and cancer, amongst other diseases, attempts to develop treatment strategies incorporating MMP inhibition have been undertaken. The results of these endeavours have been mediocre, resulting in few FDA-approved MMP inhibitors mostly due to the broad-spectrum nature of these early inhibitors and unwanted side effects of MMP inhibition. The future of exploitation of MMPs in disease lies in the design of more targeted inhibitors; in order to accomplish this, we must all understand the subtle differences between each MMP and their contextual roles. In this chapter, we aim to overview major topics regarding MMPs and what direction we may go in the future. PMID:25961691

  3. Clinical implications of matrix metalloproteinases.

    PubMed

    Mandal, Malay; Mandal, Amritlal; Das, Sudip; Chakraborti, Tapati; Sajal, Chakraborti

    2003-10-01

    Matrix metalloproteinases (MMPs) are a family of neutral proteinases that are important for normal development, wound healing, and a wide variety of pathological processes, including the spread of metastatic cancer cells, arthritic destruction of joints, atherosclerosis, pulmonary fibrosis, emphysema and neuroinflammation. In the central nervous system (CNS), MMPs have been shown to degrade components of the basal lamina, leading to disruption of the blood brain barrier and to contribute to the neuroinflammatory responses in many neurological diseases. Inhibition of MMPs have been shown to prevent progression of these diseases. Currently, certain MMP inhibitors have entered into clinical trials. A goal to the future should be to design selective synthetic inhibitors of MMPs that have minimum side effects. MMP inhibitors are designed in such a way that these can not only bind at the active site of the proteinases but also to have the characteristics to bind to other sites of MMPs which might be a promising route for therapy. To name a few: catechins, a component isolated from green tea; and Novastal, derived from extracts of shark cartilage are currently in clinical trials for the treatment of MMP-mediated diseases. PMID:14577606

  4. The Evolution of Extracellular Matrix

    PubMed Central

    Özbek, Suat; Balasubramanian, Prakash G.; Chiquet-Ehrismann, Ruth; Tucker, Richard P.

    2010-01-01

    We present a perspective on the molecular evolution of the extracellular matrix (ECM) in metazoa that draws on research publications and data from sequenced genomes and expressed sequence tag libraries. ECM components do not function in isolation, and the biological ECM system or “adhesome” also depends on posttranslational processing enzymes, cell surface receptors, and extracellular proteases. We focus principally on the adhesome of internal tissues and discuss its origins at the dawn of the metazoa and the expansion of complexity that occurred in the chordate lineage. The analyses demonstrate very high conservation of a core adhesome that apparently evolved in a major wave of innovation in conjunction with the origin of metazoa. Integrin, CD36, and certain domains predate the metazoa, and some ECM-related proteins are identified in choanoflagellates as predicted sequences. Modern deuterostomes and vertebrates have many novelties and elaborations of ECM as a result of domain shuffling, domain innovations and gene family expansions. Knowledge of the evolution of metazoan ECM is important for understanding how it is built as a system, its roles in normal tissues and disease processes, and has relevance for tissue engineering, the development of artificial organs, and the goals of synthetic biology. PMID:21160071

  5. Lecture 13: Chain Matrix Multiplication CLRS Section 15.2

    E-print Network

    Golin, Mordecai J.

    Lecture 13: Chain Matrix Multiplication CLRS Section 15.2 Revised April 17, 2003 Outline of this Lecture . Recalling matrix multiplication. . The chain matrix multiplication problem. . A dynamic programming algorithm for chain ma­ trix multiplication. 1 Recalling Matrix Multiplication Matrix: An n � m

  6. [Modern polymers in matrix tablets technology].

    PubMed

    Zimmer, ?ukasz; Kasperek, Regina; Poleszak, Ewa

    2014-01-01

    Matrix tablets are the most popular method of oral drug administration, and polymeric materials have been used broadly in matrix formulations to modify and modulate drug release rate. The main goal of the system is to extend drug release profiles to maintain a constant in vivo plasma drug concentration and a consistent pharmacological effect. Polymeric matrix tablets offer a great potential as oral controlled drug delivery systems. Cellulose derivatives, like hydroxypropyl methylcellulose (HPMC) are often used as matrix formers. However, also other types of polymers can be used for this purpose including: Kollidon SR, acrylic acid polymers such as Eudragits and Carbopols. Nevertheless, polymers of natural origin like: carragens, chitosan and alginates widely used in the food and cosmetics industry are now coming to the fore of pharmaceutical research and are used in matrix tablets technology. Modern polymers allow to obtain matrix tablets by 3D printing, which enables to develop new formulation types. In this paper, the polymers used in matrix tablets technology and examples of their applications were described. PMID:25739125

  7. Integrability in large N matrix models

    NASA Astrophysics Data System (ADS)

    Agarwal, Abhishek

    Understanding the large N limit of multi-matrix models in the Hamiltonian formalism is central to answering many important questions in the studies of Yang-Mills theories, with or without supersymmetry, and string theories. In the present work, we present an algebraic approach by which several physically interesting matrix model Hamiltonians can be diagonalized in the large N limit. This approach makes use of the connection between Hamiltonians of large N matrix models and those of quantum spin chains introduced by Rajeev and Lee in the recent past. A large class of quantum spin chains have been proven to exactly solvable quantum many body systems, and there also exists an understanding of their exact solvability in terms of novel Hopf algebraic symmetries. We present, in this work, a detailed account of how a particular kind of Hopf algebra, known as the Yangian algebra, can be realized as the symmetry of a reasonably large class of large N matrix models. We then utilize these symmetries to compute the spectra of the matrix model Hamiltonians that possess Yangian symmetries. The choice of matrix model Hamiltonians studied in the present work is governed by their applications to higher dimensional gauge theories. Four dimensional gauge theories when studied in the scheme of radial quantization produce matrix models as the effective radial Hamiltonians order by order in perturbation theory. In particular, we study matrix model Hamiltonians which are the effective Hamiltonians of superconformal Yang-Mills theory. As a by-product of the study of integrability of large N matrix models, we shall present the explicit spectrum of anomalous dimensions of superconformal Yang-Mills theory up to the third order in perturbation theory. Apart from the three loop solutions of gauge theories, several string theoretical implications of these results will also be discussed.

  8. A new look at the nuclear matrix.

    PubMed

    Hancock, R

    2000-07-01

    The concept of the nuclear matrix, a karyoskeletal structure that serves as a support for the genome and its activities, has stimulated many studies of the association of nuclear components and functions with this structure. However, certain experimental findings are not consistent with the existence of the nuclear matrix in vivo, including our inability to visualise a corresponding structure in intact cells, the demonstrated mobility in vivo of chromatin and messenger ribonucleoprotein particles, which are claimed to be bound to the nuclear matrix, the paradoxical extractability from nuclei in low ionic strength buffers of enzymes that are found in the 2 M NaCl-insoluble matrix, and the extractability, in conditions which reproduce the intranuclear milieu, of regions of DNA (matrix or scaffold attachment regions, MAR/SARs) postulated to be bound to the nuclear matrix in vivo. This review considers the nuclear matrix model in the light of sometimes overlooked evidence that each step in its isolation may cause nuclear components to bind to it by new liaisons that do not exist in vivo. This is illustrated by experiments where nuclear-targeted green fluorescent protein is found in the nuclear matrix, and raises the possibility that MAR/SARs actually bind to DNA-binding proteins or multiprotein complexes, including replicational, transcriptional and processing machinery, and topoisomerases that are incorporated into the nuclear matrix during its preparation. Considering that the nuclear lamina forms a rigid exoskeleton, the necessity for internal skeletal structures is raised; the major roles that macromolecular crowding, phase partitioning, and charge effects are likely to play in organisation of the intranuclear space may provide new models for the compartmentalisation of proteins and functions into different nuclear domains and of chromosomes into territories. PMID:10968250

  9. Visual Matrix Clustering of Social Networks

    SciTech Connect

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

    2013-07-01

    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.

  10. Anderson transition for Google matrix eigenstates

    E-print Network

    Zhirov, O V

    2015-01-01

    We introduce a number of random matrix models describing the Google matrix G of directed networks. The properties of their spectra and eigenstates are analyzed by numerical matrix diagonalization. We show that for certain models it is possible to have an algebraic decay of PageRank vector with the exponent similar to real directed networks. At the same time the spectrum has no spectral gap and a broad distribution of eigenvalues in the complex plain. The eigenstates of G are characterized by the Anderson transition from localized to delocalized states and a mobility edge curve in the complex plane of eigenvalues.

  11. P/M aluminum metal matrix composites

    NASA Technical Reports Server (NTRS)

    Rack, H. J.

    1988-01-01

    Development of lightweight, high specific stiffness engineered materials has been the long term goal of many investigators. Recently, this quest has focused on discontinuously reinforced aluminum metal matrix composites. This paper reviews the fabrication of powder metallurgy discontinuously reinforced metal matrix composites. Emphasis is given to the differences in heat treatment response reported between unreinforced and reinforced powder metallurgy materials. It is proposed that these observations can be rationalized by considering the effects of pre-existing heterogeneous nucleation sites, i.e., the dislocation substructure developed during rapid cooling of discontinuously reinforced aluminum metal matrix composites, on precipitation in reinforced aluminum alloys.

  12. High-temperature polymer matrix composites

    NASA Technical Reports Server (NTRS)

    Meador, Michael A.

    1990-01-01

    Polymers research at the NASA Lewis Research Center has produced high-temperature, easily processable resin systems, such as PMR-15. In addition, the Polymers Branch has investigated ways to improve the mechanical properties of polymers and the microcracking resistance of polymer matrix composites in response to industry need for new and improved aeropropulsion materials. Current and future research in the Polymers Branch is aimed at advancing the upper use temperature of polymer matrix composites to 700 F and beyond by developing new resins, by examining the use of fiber reinforcements other than graphite, and by developing coatings for polymer matrix composites to increase their oxidation resistance.

  13. Learned fusion operators based on matrix completion

    NASA Astrophysics Data System (ADS)

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

    2011-05-01

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

  14. Recent Developments on the CKM Matrix

    E-print Network

    Wei Wang

    2014-08-05

    In Standard Model, CP violation arises from an irreducible complex phase in the quark mixing matrix, now under the name Cabibbo-Kobayashi-Maskawa matrix. This description has shown remarkably overall agreement with various experimental measurements. In this review, we discuss recent experimental data and theoretical developments on three quantities of CKM matrix that are most uncertain: the $V_{ub}$, including its magnitude and the phase $\\gamma$ in standard parametrization, and the $B_s-\\bar B_s$ mixing phase $\\beta_s$.

  15. Transport Maps for {?} -Matrix Models and Universality

    NASA Astrophysics Data System (ADS)

    Bekerman, F.; Figalli, A.; Guionnet, A.

    2015-05-01

    We construct approximate transport maps for non-critical {?} -matrix models, that is, maps so that the push forward of a non-critical {?} -matrix model with a given potential is a non-critical {?} -matrix model with another potential, up to a small error in the total variation distance. One of the main features of our construction is that these maps enjoy regularity estimates that are uniform in the dimension. In addition, we find a very useful asymptotic expansion for such maps which allows us to deduce that local statistics have the same asymptotic behavior for both models.

  16. A transilient matrix for moist convection

    SciTech Connect

    Romps, D.; Kuang, Z.

    2011-08-15

    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.

  17. Tabular data boundary-state analysis of the Edwards cycle

    Microsoft Academic Search

    A. L. Ecker; T. C. Edwards; K. Jr. Wark

    1978-01-01

    A simplified analytical method was developed for determining the theoretical ideal performance of the Edwards cycle employing only tabulated boundary-state thermodynamic property data. The ideal Edwards cycle employs a multi-component\\/mixed-phase refrigerant which undergoes two heat transfer processes and isentropic compression and expansion processes. This cycle has been previously analyzed through the application of a polytropic model for the compression and

  18. A new numerical solution to traditional phytosociological tabular classification

    Microsoft Academic Search

    Otto Wildi

    1989-01-01

    Often, manually and numerically derived phytosociological classifications yield different results. Hitherto, a twostep procedure has been suggested in which numerical analysis of the data is followed by the revision of the resulting table (c.f. van der Maarel 1982). In this paper a new methodology is presented which makes manual refinements superfluous. Objectives are derived from phytosociological paradigms and conclusions drawn

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

    E-print Network

    2010-11-05

    with the standard BCD method. Partitioning the binary ..... 1560. 41314. 40560. 973. 5452 table 12. 21476. 2062. 1684. 43784. 42952. 2062. 9932 ..... propositional satisfiability, IEEE Transactions on Computers 48, 506–521. [25] Plazas, M.A. ...

  20. Consistent thermodynamic derivative estimates for tabular equations of state

    Microsoft Academic Search

    Gary A. Dilts

    2006-01-01

    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

  1. MHD simulations of MTF implosions with tabular EOS and conductivities

    Microsoft Academic Search

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

    2003-01-01

    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

  2. Analyzing Tabular Requirements Specifications Using Infinite State Model Checking

    E-print Network

    techniques for finite state systems, especially in techniques based on model check- ing [8]. In hardware and events. A condition is a predicate defined on a system state. A basic event, denoted @T(c), indicates Univ. of California, Santa Barbara Constance Heitmeyer2 Naval Research Laboratory Abstract This paper

  3. Developments in western Canada in 1979. [Tabular data and maps

    Microsoft Academic Search

    Hay

    1980-01-01

    In 1979, another all-time drilling record was set in Western Canada, with 7387 wells being drilled, an increase of 7% over 1978. Exploratory drilling decreased slightly to 2884 wells, down 5%, but development drilling reached record numbers, with 4503 wells, up 17% from 1978. The exploratory success rate was significantly higher at 63% in 1979, based on 713 oil discoveries

  4. Developments in western Canada in 1979. [Tabular data and maps

    SciTech Connect

    Hay, P.W.

    1980-09-01

    In 1979, another all-time drilling record was set in Western Canada, with 7387 wells being drilled, an increase of 7% over 1978. Exploratory drilling decreased slightly to 2884 wells, down 5%, but development drilling reached record numbers, with 4503 wells, up 17% from 1978. The exploratory success rate was significantly higher at 63% in 1979, based on 713 oil discoveries and 1101 gas discoveries. The development success rate stayed constant at 88%, from 1597 oil discoveries and 2349 gas discoveries. Records were set in average well depths and average land prices paid in Alberta and British Columbia. The most significant event in petroleum exploration in Western Canada for many years was the massive Kopanoar oil discovery in the Beaufort Sea, with estimated flow rates of 1900 cu m/d (12,000 b/d) of 28/sup 0/ sweet crude. A major Arctic Island gas discovery was also made in the Whitefish well near Drake Point. Alberta activity shifted into the deeper Alberta basin and foothills, with oil and gas discoveries south of Calgary at Claresholm, gas discoveries in the central foothills at Erith-Hanlan, Blackstone, and Brown Creek, and oil discoveries farther north in the deep-basin area at Wembley and Beaverlodge. A record $28.2 million bonus (or $8,400/ha) was paid for a single license in the Beaverlodge Triassic oil play by Esso and Pan-Canadian. Deep-basin development drilling in the tight Cretaceous sandstones continued in the Cutbank oil play and Elmworth gas trend, with emphasis on the westward extension of Elmworth into British Columbia. In eastern Alberta, shallow gas exploration is proceeding strongly at Suffield and Primrose Lake. Major British Columbia gas strikes were made in the southwest corner of the explored area at Sukunka and Monias. In southeast Saskatchewan, a Mississippian oil strike was made at Tatagwa.

  5. SHORT COMMUNICATION Open Access Extracellular matrix rigidity modulates

    E-print Network

    Kumar, Sanjay

    cues encoded in the extracellular matrix (ECM). While signaling between tumor cells and the ECM that cross-talk between neuroblastoma cells and the extracellular matrix (ECM) influences differentiation [2SHORT COMMUNICATION Open Access Extracellular matrix rigidity modulates neuroblastoma cell

  6. Deflating Quadratic Matrix Polynomials with Structure Preserving Transformations

    E-print Network

    Tisseur, Francoise

    polynomials, both theoretically and numerically, is to convert them into equivalent linear matrix pencilsDeflating Quadratic Matrix Polynomials with Structure Preserving Transformations Francoise Tisseur ISSN 1749-9097 #12;Deflating Quadratic Matrix Polynomials with Structure Preserving Transformations

  7. Active Matrix OLED Test Report

    NASA Technical Reports Server (NTRS)

    Salazar, George

    2013-01-01

    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.

  8. Matrix Models, Emergent Spacetime and Symmetry Breaking

    NASA Astrophysics Data System (ADS)

    Grosse, Harald; Lizzi, Fedele; Steinacker, Harold

    2009-12-01

    We discuss how a matrix model recently shown to describe emergent gravity may contain extra degrees of freedom which reproduce some characteristics of the standard model, in particular the breaking of symmetries and the correct quantum numbers of fermions.

  9. Quantized Matrix Algebras and Quantum seeds

    E-print Network

    Hans Plesner Jakobsen; Chiara Pagani

    2012-10-26

    We determine explicit quantum seeds for classes of quantized matrix algebras. Furthermore, we obtain results on centers and block diagonal forms {of these algebras.} In the case where $q$ is {an arbitrary} root of unity, this further determines the degrees.

  10. Software for Fault-Tolerant Matrix Multiplication

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  11. Structural Analysis and Matrix Interpretive System /SAMIS/

    NASA Technical Reports Server (NTRS)

    1967-01-01

    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.

  12. Quantum restrictions on transfer of matrix elements

    E-print Network

    Armen E. Allahverdyan; Karen Hovhannisyan

    2008-11-15

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

  13. Integrated optic vector-matrix multiplier

    DOEpatents

    Watts, Michael R. (Albuquerque, NM)

    2011-09-27

    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.

  14. Chondrule-matrix relationships in chondritic meteorites

    NASA Technical Reports Server (NTRS)

    Brearley, A. J.

    1994-01-01

    The relationship between chondrules and matrix (fine grained material with a grain size less than 5 micrometers) in chondritic meteorites has been the subject of considerable controversy and no consensus currently exists. The coexistence of these two components in meteorites with bulk compositions that deviate only slightly from CI abundances suggests that cosmochemically their origins are closely linked. Any consideration of the relationship between chondrules and matrix hinges to a large degree on the origin of matrix. The entire spectrum of models exists from matrix as a nebular product to derivation entirely from chondrules. Early models of solar nebular evolution viewed chondrites as a two-component mixture of high- and low-temperature condensates. However, this model has been challenged by the recognition that the nebula was probably not uniformly vaporized.

  15. Axial grading of inert matrix fuels

    SciTech Connect

    Recktenwald, G. D.; Deinert, M. R. [Dept. of Mechanical Engineering, Univ. of Texas, Austin, TX (United States)

    2012-07-01

    Burning actinides in an inert matrix fuel to 750 MWd/kg IHM results in a significant reduction in transuranic isotopes. However, achieving this level of burnup in a standard light water reactor would require residence times that are twice that of uranium dioxide fuels. The reactivity of an inert matrix assembly at the end of life is less than 1/3 of its beginning of life reactivity leading to undesirable radial and axial power peaking in the reactor core. Here we show that axial grading of the inert matrix fuel rods can reduce peaking significantly. Monte Carlo simulations are used to model the assembly level power distributions in both ungraded and graded fuel rods. The results show that an axial grading of uranium dioxide and inert matrix fuels with erbium can reduces power peaking by more than 50% in the axial direction. The reduction in power peaking enables the core to operate at significantly higher power. (authors)

  16. Matrix Factorization Techniques for Recommender Systems

    Microsoft Academic Search

    Yehuda Koren; Robert M. Bell; Chris Volinsky

    2009-01-01

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

  17. Plato's Fire and the Neutrino Mass Matrix

    E-print Network

    Ernest Ma

    2002-11-25

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

  18. Periodic stabilizing matrices: A monodromy matrix approach

    Microsoft Academic Search

    Luis Moreno-Ahedo; Carlos Vazquez

    2011-01-01

    The construction of time-periodic stabilizing matrices by the monodromy matrix approach is presented, the time-periodic stabilizing matrices are a special case of time-varying stabilizing matrices formulated in the Brockett problem, a open problem in control theory; a practical example about construction of time-periodic stabilizing matrix for the vertical stabilization of the pendulum with oscillating pivot is given.

  19. Holographic geometry and noise in matrix theory

    Microsoft Academic Search

    Craig J. Hogan; Mark G. Jackson

    2009-01-01

    Using Matrix Theory as a concrete example of a fundamental holographic\\u000atheory, we show that the emergent macroscopic spacetime displays a new\\u000amacroscopic quantum structure, holographic geometry, and a new observable\\u000aphenomenon, holographic noise, with phenomenology similar to that previously\\u000aderived on the basis of a quasi-monochromatic wave theory. Traces of matrix\\u000aoperators on a light sheet with a compact

  20. Unexpected matrix diseases and novel therapeutic strategies

    Microsoft Academic Search

    Claudia Nicolae; Bjorn R. Olsen

    2010-01-01

    Within the framework of a broad definition of the extracellular matrix (ECM), this review discusses three genetic disorders\\u000a in which major pathogenetic features have been traced back to alterations in the levels\\/activities of matrix components. In\\u000a each case, disease-associated alterations are found both intra- and extracellularly. The nature of the ECM involvement is\\u000a surprising, offers an exciting therapeutic opportunity, and

  1. PuraMatrix encapsulation of cancer cells.

    PubMed

    Abu-Yousif, Adnan O; Rizvi, Imran; Evans, Conor L; Celli, Jonathan P; Hasan, Tayyaba

    2009-01-01

    Increasing evidence suggests that culturing cancer cells in three dimensions more accurately recapitulates the complexity of tumor biology. Many of these models utilize reconstituted basement membrane derived from animals which contain a variable amount of growth factors and cytokines that can influence the growth of these cell culture models. Here, we describe in detail the preparation and use of PuraMatrix, a commercially available self assembling peptide gel that is devoid of animal-derived material and pathogens to encapsulate and propagate the ovarian cancer cell line, OVCAR-5. We begin by describing how to prepare the PuraMatrix prior to use. Next, we demonstrate how to properly mix the PuraMatrix and cell suspension to encapsulate the cells in the hydrogel. Upon the addition of cell culture media or injection into a physiological environment, the peptide component of PuraMatrix rapidly self assembles into a 3D hydrogel that exhibits a nanometer scale fibrous structure with an average pore size of 5-200 nm(1). In addition, we demonstrate how to propagate cultures grown in encapsulated PuraMatrix. When encapsulated in PuraMatrix, OVCAR-5 cells assemble into three dimensional acinar structures that more closely resemble the morphology of micrometastatic nodules observed in the clinic than monolayer in vitro models. Using confocal microscopy we illustrate the appearance of representative OVCAR-5 cells encapsulated in PuraMatrix on day 1, 3, 5, and 7 post plating. The use of PuraMatrix to culture cancer cells should improve our understanding of the disease and allow us to assess treatment response in more clinically predictive model systems. PMID:20019656

  2. Matrix effects in plasma desorption mass spectrometry

    Microsoft Academic Search

    Stephane Bouchonnet; Yannik Hoppilliard; Christine Mauriac

    1993-01-01

    In Plasma Desorption (PD) Mass Spectrometry, valine\\/matrix mixtures have been studied in order to specify the influence of a matrix during the desorption-ionization (DI) of volume. The different matrices used were carboxylic acids (barbituric acid, 2-chloronicotinic acid, 3-chloropropionic acid, cysteine, pentafluorobenzoic acid, picric acid, sinapinic acid) and CsI, an inorganic salt. Three effects are proposed to explain the influence of

  3. Finding Unusual Correlation Using Matrix Decompositions

    Microsoft Academic Search

    David B. Skillicorn

    2004-01-01

    \\u000a One important aspect of terrorism detection is the ability to detect small-scale, local correlations against a background\\u000a of large-scale, diffuse correlations. Several matrix decompositions transform correlation into other properties: for example,\\u000a Singular Value Decomposition (SVD) transforms correlation into proximity, and SemiDiscrete Decomposition (SDD) transforms\\u000a correlation into regions of increased density. Both matrix decompositions are effective at detecting local correlation in

  4. Molten carbonate fuel cell matrix tape

    SciTech Connect

    Vine, R.W.; Schroll, C.R.; Reiser, C.A.

    1986-04-08

    A matrix material for a molten carbonate fuel cell is described comprising particles inert to molten carbonate electrolyte having a particle size less than about 1 micron, ceramic particles having a particle size greater than about 25 microns, and an organic polymeric binder material, the binder material being present in an amount at least about 35% by volume, the matrix material being flexible, pliable, and compliant at room temperature.

  5. Email Surveillance Using Nonnegative Matrix Factorization

    Microsoft Academic Search

    Michael W. Berry; Murray Browne

    2005-01-01

    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

  6. LIQUID PHASE SINTERED METAL MATRIX COMPOSITE MATERIALS

    Microsoft Academic Search

    S. J. Yankee; G. M. Janowski; B. J. Pletka

    1990-01-01

    Iron-base and aluminum-base composite materials reinforced with various ceramic particulates have been fabricated via powder metallurgy and liquid phase sintering. The advantage of this manufacturing route is that conventional powder metallurgy processing equipment can be used to fabricate metal matrix\\/ceramic composites. Furthermore, this approach makes it possible to manufacture these composites to near-net-shape. A number of matrix\\/ceramic combinations have been

  7. Helium in inert matrix dispersion fuels

    Microsoft Academic Search

    A. van Veen; R. J. M Konings; A. V Fedorov

    2003-01-01

    The behaviour of helium, an important decay product in the transmutation chains of actinides, in dispersion-type inert matrix fuels is discussed. A phenomenological description of its accumulation and release in CERCER and CERMET fuel is given. A summary of recent He-implantation studies with inert matrix metal oxides (ZrO2, MgAl2O4, MgO and Al2O3) is presented. A general picture is that for

  8. SALTSTONE MATRIX CHARACTERIZATION AND STADIUM SIMULATION RESULTS

    Microsoft Academic Search

    Langton

    2009-01-01

    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

  9. Micromechanical Modeling of Woven Metal Matrix Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pindera, Marek-Jerzy

    1997-01-01

    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.

  10. Numerical analysis of a quadratic matrix equation

    Microsoft Academic Search

    NICHOLAS J. HIGHAM; HYUN-MIN KIM

    1999-01-01

    The quadratic matrix equation AX2+BX +C = 0 in n \\\\Theta n matrices arises inapplications and is of intrinsic interest as one of the simplest nonlinear matrix equations.We give a complete characterization of solutions in terms of the generalizedSchur decomposition and describe and compare various numerical solution techniques.In particular, we give a thorough treatment of functional iteration methodsbased on Bernoulli's

  11. Turnover of matrix proteins in mammalian mitochondria.

    PubMed Central

    Huth, Walter; Rolle, Stefan; Wunderlich, Ilona

    2002-01-01

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

  12. String interactions from Matrix string theory

    Microsoft Academic Search

    G. Bonelli; L. Bonora; F. Nesti

    1999-01-01

    Matrix string theory, i.e. the two-dimensional U(N) SYM with N = (8,8) supersymmetry, has classical BPS solutions that interpolate between an initial and a final string configuration via a bordered Riemann surface. The Matrix string theory amplitudes around such a classical BPS background, in the strong Yang-Mills coupling, are therefore candidates to be interpreted in a stringy way as the

  13. Mechanisms balancing skeletal matrix synthesis and degradation.

    PubMed Central

    Blair, Harry C; Zaidi, Mone; Schlesinger, Paul H

    2002-01-01

    Bone is regulated by evolutionarily conserved signals that balance continuous differentiation of bone matrix-producing cells against apoptosis and matrix removal. This is continued from embryogenesis, where the skeleton differentiates as a solid mass and is shaped into separate bones by cell death and proteolysis. The two major tissues of the skeleton are avascular cartilage, with an extracellular matrix based on type II collagen and hydrophilic proteoglycans, and bone, a stronger and lighter material based on oriented type I collagen and hydroxyapatite. Both differentiate from the same mesenchymal stem cells. This differentiation is regulated by a family of related signals centred on bone morphogenic proteins. Fibroblast growth factors, Indian hedgehog and parathyroid hormone-related protein are important in determining the type of matrix and the relation of skeletal and non-skeletal structures. Removal of mineralized matrix involves apoptosis of matrix cells and differentiation of acid-secreting cells (osteoclasts) from macrophage precursors. Key regulators of matrix removal are signals in the tumour-necrosis-factor family. Osteoclasts dissolve bone by isolating a region of the matrix and secreting HCl and proteinases at that site. Successive cycles of removal and replacement allow growth, repair and remodelling. The signals for bone turnover are predominantly cell-membrane-associated, allowing very specific spatial regulation. In addition to its support function, bone is a reservoir of Ca2+, PO3-(4) and OH-. Secondary modulation of mineral secretion and bone degradation are mediated by humoral signals, including parathyroid hormone and vitamin D, as well as the cytokines that also regulate the underlying cell differentiation. PMID:12023876

  14. Topological String Correlators from Matrix Models

    E-print Network

    Robert de Mello Koch; Lwazi Nkumane

    2015-02-07

    We discuss how to compute connected matrix model correlators for operators related to the gravitational descendants of the puncture operator, for the topological A model on P^1. The relevant correlators are determined by recursion relations that follow from a systematic 1/N expansion of well chosen Schwinger-Dyson equations. Our results provide further compelling evidence for Gopakumar's proposed "simplest gauge string duality" between the Gaussian matrix model and the topological A model on P^1.

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

    NASA Technical Reports Server (NTRS)

    2003-01-01

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

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

    NASA Technical Reports Server (NTRS)

    2003-01-01

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

  17. Temperature dependent nonlinear metal matrix laminae behavior

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  18. Matrix method for acoustic levitation simulation.

    PubMed

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

    2011-08-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  20. Experimental study on mechanical behavior of fiber/matrix interface in metal matrix composite

    SciTech Connect

    Wang, Q.; Chiang, F.P. [State Univ. of New York, Stony Brook, NY (United States). Lab. for Experimental Mechanics Research

    1994-12-31

    The technique SIEM(Speckle Interferometry with Electron Microscopy) was employed to quantitatively measure the deformation on the fiber/matrix interface in SCS-6/Ti-6-4 composite at a microscale level. The displacement field within the fiber/matrix interphase zone was determined by in-situ observation with sensitivity of 0.003({micro}m). The macro-mechanical properties were compared with micro-mechanical behavior. It is shown that the strength in the interphase zone is weaker than the matrix tensile strength. The deformation process can be characterized by the uniform deformation, interface strain concentration and debond, and matrix plastic deformation.

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

    NASA Technical Reports Server (NTRS)

    Honecy, Frank S.; Pepper, Stephen V.

    1988-01-01

    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.

  2. Fatigue damage criteria - Matrix, fibers and interfaces of continuous fiber reinforced metal matrix composites

    NASA Technical Reports Server (NTRS)

    Johnson, W. S.

    1988-01-01

    Continuous fiber reinforced metal matrix composites (MMC) are projected for use in high temperature, stiffness critical parts that will be subjected to cyclic loadings. Depending on the relative fatigue behavior of the fiber and matrix, and the interface properties, the failure modes of MMC can be grouped into four catagories: (1) matrix dominated, (2) fiber dominated, (3) self-similar damage growth, and (4) fiber/matrix interfacial failures. These four types of damage are discussed and illustrated by examples. The emphasis is on the fatigue of unnotched laminates.

  3. Shrinkage Estimation of the Realized Relationship Matrix

    PubMed Central

    Endelman, Jeffrey B.; Jannink, Jean-Luc

    2012-01-01

    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. PMID:23173092

  4. Formulation of matrix solutions for use in matrix-assisted laser desorption/ionization of biomolecules.

    PubMed

    Sze, E T; Chan, T W; Wang, G

    1998-02-01

    We report a simple method for converting solid matrices into useful matrix solutions for matrix-assisted laser desorption/ionization (MALDI). This method is based on the dissolution of the solid matrix in a liquid support of low volatility such as glycerol. An appropriate solubilizing reagent was added to promote the dissolution of the matrix materials into the liquid support. Selection of the solubilizing reagent is empirically related to an acid-base relationship, i.e., an acidic solid matrix requires a basic organic compound to form a stable matrix solution in the liquid support and vice versa. A tenfold increase in the solubility can be obtained for many solid matrices when appropriate solubilizing reagents are added into the glycerol support. This solubility enhancement is tentatively attributed to the ion-pair formation in a polar nonvolatile liquid support. In addition, the hydrophobicity of the solid matrix seems to play an important role in the efficiency of the resulting matrix solution. By using glycerol as liquid support, a hydrophilic matrix, such as 2,5-dihydroxybenzoic acid (DHB), showed a substantial "peripheral effect," in which good analyte ion signals could only be recorded at the peripheral region of the sample droplet. More hydrophobic matrices, such as alpha-cyano-4-hydroxycinnamic acid (alpha-CCA), exhibit better and more homogeneous responses at different regions of the droplets. The performance of these matrix solutions was evaluated in terms of the durability, reproducibility, sensitivity, high mass capability, and generality. A typical sample droplet can afford more than an hour of repeated sampling with excellent shot-to-shot reproducibility. A low picomole sensitivity was demonstrated using a luteinizing hormone releasing hormone (LHRH) in a Fourier transform ion cyclotron resonance mass spectrometer with a homemade external MALDI ion source. By using a commercial MALDI time-of-flight mass spectrometer, proteins with masses as high as 66,000 Da were successfully analyzed by using these matrix solutions. PMID:9679596

  5. Thermal stress effects in intermetallic matrix composites

    NASA Astrophysics Data System (ADS)

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

    1993-09-01

    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.

  6. Inelastic deformation of metal matrix composites

    NASA Technical Reports Server (NTRS)

    Lissenden, C. J.; Herakovich, C. T.; Pindera, M-J.

    1993-01-01

    A theoretical model capable of predicting the thermomechanical response of continuously reinforced metal matrix composite laminates subjected to multiaxial loading was developed. A micromechanical model is used in conjunction with nonlinear lamination theory to determine inelastic laminae response. Matrix viscoplasticity, residual stresses, and damage to the fiber/matrix interfacial zone are explicitly included in the model. The representative cell of the micromechanical model is considered to be in a state of generalized plane strain, enabling a quasi two-dimensional analysis to be performed. Constant strain finite elements are formulated with elastic-viscoplastic constitutive equations. Interfacial debonding is incorporated into the model through interface elements based on the interfacial debonding theory originally presented by Needleman, and modified by Tvergaard. Nonlinear interfacial constitutive equations relate interfacial tractions to displacement discontinuities at the interface. Theoretical predictions are compared with the results of an experimental program conducted on silicon carbide/titanium (SiC/Ti) unidirectional, (O4), and angle-ply, (+34)(sub s), tubular specimens. Multiaxial loading included increments of axial tension, compression, torque, and internal pressure. Loadings were chosen in an effort to distinguish inelastic deformation due to damage from matrix plasticity and separate time-dependent effects from time-independent effects. Results show that fiber/matrix debonding is nonuniform throughout the composite and is a major factor in the effective response. Also, significant creep behavior occurs at relatively low applied stress levels at room temperature.

  7. Google Matrix Analysis of DNA Sequences

    PubMed Central

    Kandiah, Vivek; Shepelyansky, Dima L.

    2013-01-01

    For DNA sequences of various species we construct the Google matrix 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 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

  8. Fabrication of metal matrix composites of

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Mullins, M. E.; Wijayatilleke, K.; Lee, J. K.

    1992-09-01

    Fine fibrous titanium carbide (TiC) was processed through the self-propagating high-temperature synthesis (SHS) method and employed to fabricate aluminum matrix composites. Two consol-idation methods were investigated: (1) combustion synthesis of TiC fiber/Al composites directly using titanium powders and carbon fibers ignited simultaneously with varying amounts of the matrix metal powder and (2) combustion synthesis of TiC using titanium powders and carbon fibers followed by consolidation into different amounts of the metal matrix powder, Al, via hot isostatic pressing (HIP). In the former method, when the amount of the Al in the matrix was increased, the maximum temperature obtained by the combustion reaction decreased and the propagation of the synthesis reactions became difficult to maintain. Preheating was required for the mixture of reactants with more than approximately 5 mole pct aluminum matrix powders in order to ignite and maintain the propagation rate. Microstructural analysis of the products from the Al/C/Ti reaction without preheating shows that small amounts of an aluminum carbide phase (AI4C3) are present. In the second method, following separation of the individual fibers in the TiC product, dense composites containing the SHS products were obtained by HIP of a mixture of the TiC fibers and Al powders. No ternary phase was formed during this procedure.

  9. Matrix Metalloproteinase Control of Capillary Morphogenesis

    PubMed Central

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

    2010-01-01

    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. PMID:18540825

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

    SciTech Connect

    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

    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.

  11. Extracellular Matrix 2: Role of extracdllular matrix rnoiecui#{243} and their receptors in the nervous system

    Microsoft Academic Search

    XRISTINE A. VENSTROM; LOUIS F. REICHARDT

    1993-01-01

    .:. - This is the second installment in a series of reviews exploring the biologi- cal role of the extracellular matrix. The first review, by C.Q, Lin and M.J. Bissell (FJ 7, 737-743, 1993), dealt with the effect of the matrix in governing the behavior of cells embedded in it. This theme is now elabo- rated, in the present review

  12. MatrixGuest Energy Transfer in Matrix-assisted Laser Desorption

    E-print Network

    Vertes, Akos

    indicates that in the case of 1500 K and 3000 K the desorption process is complete, whereas at 900 K and guest molecules depend on the initial matrix temperature jump. The initial matrix temperature of 900 K leads to incomplete desorption, whereas at 1500 K complete desorption and the formation of an energy

  13. Viewing Polynomial Roots With Matrix Eyes: Part 1: Irrational Roots via Matrix Dynamics

    E-print Network

    Kalman, Dan

    1 Viewing Polynomial Roots With Matrix Eyes: Part 1: Irrational Roots via Matrix Dynamics Part 2 that converges to 0 #12;8 Dynamical View · Consider the orbits under repeated application of A starting from entries · Orbits from lattice points all converge to the line L · Let v be any integer vector. Let vn = A

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

    E-print Network

    the effects of matrix temperature oscillations Stig Kildega°rd Andersen a,*, Henrik Carlsen a , Per Grove in good agreement with experimental data was used for mapping the per- formance of the engine, for mapping the effects of regenerator matrix temperature oscillations, and for optimising the regenerator design

  15. Effect of matrix and atmosphere on the creep deformation of aluminum alloy matrix composites

    Microsoft Academic Search

    Norio Matsuda; Hideki Tazawa; Satoshi Ishikawa; Mitsuru Saitoh

    2001-01-01

    Creep behavior of two types of aluminum alloy matrix composites, which were reinforced with alumina particles and have different matrix alloy, have been investigated at temperatures from 573 to 773 K. Matrices of the composites were 6061 and 2014 Al alloys. The composites contained about 10 or 20 vol.% of alumina particles, the size of which is about 10–30 ?m.

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

    NASA Technical Reports Server (NTRS)

    Shepperd, S. W.

    1978-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    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.

  18. Extracellular Matrix and Its Receptors in Drosophila Neural Development

    E-print Network

    Broadie, Kendal S.

    ; neural stem cells; Drosophila INTRODUCTION The extracellular matrix (ECM) makes up a stagger- ing 50Extracellular Matrix and Its Receptors in Drosophila Neural Development Kendal Broadie,1 Stefan matrix (ECM) and matrix receptors are intimately involved in most bio- logical processes. The ECM plays

  19. Contemporary Mathematics A New Multidimensional Matrix Inversion in A r

    E-print Network

    Schlosser, Michael

    matrix inversion, inverse relations, Ar basic hy- pergeometric series, Ar q-Abel identities, Ar qContemporary Mathematics A New Multidimensional Matrix Inversion in A r Michael Schlosser Dedicated-dimensional matrix, thus giving an extension of our previous matrix inversion result. As applications, we derive new

  20. The biofilm matrix – an immobilized but dynamic microbial environment

    Microsoft Academic Search

    Ian W Sutherland

    2001-01-01

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

  1. A novel matrix converter topology with simple commutation

    Microsoft Academic Search

    Lixiang Wei; T.A. Lipo

    2001-01-01

    The matrix converter is very simple in structure and has powerful controllability. However, the commutation problem and complicated PWM method keep it from being utilized in industry. This paper discloses a novel matrix topology with advantages over the usual matrix converter topology. Firstly, it has the same performance as a conventional matrix converter in terms of voltage transfer ratio capacity,

  2. Application of the matrix converter to induction motor drives

    Microsoft Academic Search

    Takayoshi Matsuo; Steffen Bernet; R. S. Colby; T.A. Lipo

    1996-01-01

    This paper presents the technical issues of applying the matrix power converter to field-oriented induction motor drives. A newly developed matrix power converter switching sequence combination is described in detail, the purpose of which is to minimize harmonic components of the matrix power converter input currents. It is demonstrated that small size capacitors work efficiently as input filters. Matrix power

  3. Thermal and mechanical behavior of metal matrix and ceramic matrix composites

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  4. Instantons and merons in matrix models

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Mironov, A.; Morozov, A.

    2007-11-01

    Various branches of matrix model partition functions can be represented as intertwined products of universal elementary constituents: Gaussian partition functions ZG and Kontsevich ?-functions ZK. In physical terms, this decomposition is the matrix model version of multi-instanton and multi-meron configurations in Yang-Mills theories. Technically, decomposition formulas are related to the representation theory of algebras of Krichever-Novikov type on families of spectral curves with additional Seiberg-Witten structure. Representations of these algebras are encoded in terms of “the global partition functions”. They interpolate between ZG and ZK, associated with different singularities on spectral Riemann surfaces. This construction is nothing but M-theory-like unification of various matrix models with explicit and representative realization of dualities.

  5. Accelerated matrix element method with parallel computing

    NASA Astrophysics Data System (ADS)

    Schouten, D.; DeAbreu, A.; Stelzer, B.

    2015-07-01

    The matrix element method utilizes ab initio calculations of probability densities as powerful discriminants for processes of interest in experimental particle physics. The method has already been used successfully at previous and current collider experiments. However, the computational complexity of this method for final states with many particles and degrees of freedom sets it at a disadvantage compared to supervised classification methods such as decision trees, k nearest-neighbor, or neural networks. This note presents a concrete implementation of the matrix element technique using graphics processing units. Due to the intrinsic parallelizability of multidimensional integration, dramatic speedups can be readily achieved, which makes the matrix element technique viable for general usage at collider experiments.

  6. Resolving resonances in R-matrix calculations

    NASA Astrophysics Data System (ADS)

    Ramírez, J. M.; Bautista, Manuel A.

    2002-10-01

    We present a technique to obtain detailed resonance structures from R-matrix calculations of atomic cross sections for both collisional and radiative processes. The resolving resonances (RR) method relies on the QB method of Quigley-Berrington (Quigley L, Berrington K A and Pelan J 1998 Comput. Phys. Commun. 114 225) to find the position and width of resonances directly from the reactance matrix. Then one determines the symmetry parameters of these features and generates an energy mesh whereby fully resolved cross sections are calculated with minimum computational cost. The RR method is illustrated with the calculation of the photoionization cross sections and the unified recombination rate coefficients of Fe XXIV, O VI, and Fe XVII. The RR method reduces numerical errors arising from unresolved R-matrix cross sections in the computation of synthetic bound-free opacities, thermally averaged collision strengths and recombination rate coefficients.

  7. Electrolyte matrix for molten carbonate fuel cells

    DOEpatents

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

    1999-02-09

    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.

  8. The transfer matrix: A geometrical perspective

    NASA Astrophysics Data System (ADS)

    Sánchez-Soto, Luis L.; Monzón, Juan J.; Barriuso, Alberto G.; Cariñena, José F.

    2012-04-01

    We present a comprehensive and self-contained discussion of the use of the transfer matrix to study propagation in one-dimensional lossless systems, including a variety of examples, such as superlattices, photonic crystals, and optical resonators. In all these cases, the transfer matrix has the same algebraic properties as the Lorentz group in a (2+1)-dimensional spacetime, as well as the group of unimodular real matrices underlying the structure of the abcd law, which explains many subtle details. We elaborate on the geometrical interpretation of the transfer-matrix action as a mapping on the unit disk and apply a simple trace criterion to classify the systems into three types with very different geometrical and physical properties. This approach is applied to some practical examples and, in particular, an alternative framework to deal with periodic (and quasiperiodic) systems is proposed.

  9. Accelerated Matrix Element Method with Parallel Computing

    E-print Network

    Doug Schouten; Adam DeAbreu; Bernd Stelzer

    2014-07-30

    The matrix element method utilizes ab initio calculations of probability densities as powerful discriminants for processes of interest in experimental particle physics. The method has already been used successfully at previous and current collider experiments. However, the computational complexity of this method for final states with many particles and degrees of freedom sets it at a disadvantage compared to supervised classification methods such as decision trees, k nearest-neighbour, or neural networks. This note presents a concrete implementation of the matrix element technique using graphics processing units. Due to the intrinsic parallelizability of multidimensional integration, dramatic speedups can be readily achieved, which makes the matrix element technique viable for general usage at collider experiments.

  10. Google matrix analysis of directed networks

    E-print Network

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

    2015-06-19

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

  11. t matrix of metallic wire structures

    SciTech Connect

    Zhan, T. R., E-mail: phystrzhan@gmail.com; Chui, S. T., E-mail: chui@bartol.udel.edu [Bartol Research Institute, University of Delaware, Newark, Delaware 19716 (United States)

    2014-04-14

    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.

  12. t matrix of metallic wire structures

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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.

  13. Decorin modulates matrix mineralization in vitro

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  14. Ethynylated aromatics as high temperature matrix resins

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1986-01-01

    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.

  15. Entanglement in Gaussian matrix-product states

    SciTech Connect

    Adesso, Gerardo [Centre for Quantum Computation, DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Dipartimento di Fisica 'E. R. Caianiello', Universita degli Studi di Salerno, INFN Sezione di Napoli-Gruppo Collegato di Salerno, Via S. Allende, 84081 Baronissi (Saudi Arabia) (Italy); Ericsson, Marie [Centre for Quantum Computation, DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2006-09-15

    Gaussian matrix-product states are obtained as the outputs of projection operations from an ancillary space of M infinitely entangled bonds connecting neighboring sites, applied at each of N sites of a harmonic chain. Replacing the projections by associated Gaussian states, the building blocks, we show that the entanglement range in translationally invariant Gaussian matrix-product states depends on how entangled the building blocks are. In particular, infinite entanglement in the building blocks produces fully symmetric Gaussian states with maximum entanglement range. From their peculiar properties of entanglement sharing, a basic difference with spin chains is revealed: Gaussian matrix-product states can possess unlimited, long-range entanglement even with minimum number of ancillary bonds (M=1). Finally we discuss how these states can be experimentally engineered from N copies of a three-mode building block and N two-mode finitely squeezed states.

  16. Electrolyte matrix for molten carbonate fuel cells

    DOEpatents

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

    1999-01-01

    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.

  17. Density matrix of black hole radiation

    E-print Network

    Lasma Alberte; Ram Brustein; Andrei Khmelnitsky; A. J. M. Medved

    2015-06-30

    Hawking's model of black hole evaporation is not unitary and leads to a mixed density matrix for the emitted radiation, while the Page model describes a unitary evaporation process in which the density matrix evolves from an almost thermal state to a pure state. We compare a recently proposed model of semiclassical black hole evaporation to the two established models. In particular, we study the density matrix of the outgoing radiation and determine how the magnitude of the off-diagonal corrections differs for the three frameworks. For Hawking's model, we find power-law corrections to the two-point functions that induce exponentially suppressed corrections to the off-diagonal elements of the full density matrix. This verifies that the Hawking result is correct to all orders in perturbation theory and also allows one to express the full density matrix in terms of the single-particle density matrix. We then consider the semiclassical theory for which the corrections, being non-perturbative from an effective field-theory perspective, are much less suppressed and grow monotonically in time. In this case, the R\\'enyi entropy for the outgoing radiation is shown to grow linearly at early times; but this growth slows down and the entropy eventually starts to decrease at the Page time. In addition to comparing models, we emphasize the distinction between the state of the radiation emitted from a black hole, which is highly quantum, and that of the radiation emitted from a typical classical black body at the same temperature.

  18. RANDOMNESS of Numbers DEFINITION(QUERY:WHAT? V HOW?) ONLY Via MAXWELL-BOLTZMANN CLASSICAL-Statistics(MBCS) Hot-Plasma VS. Digits-Clumping Log-Law NON-Randomness Inversion ONLY BOSE-EINSTEIN QUANTUM-Statistics(BEQS) .

    NASA Astrophysics Data System (ADS)

    Siegel, Z.; Siegel, Edward Carl-Ludwig

    2011-03-01

    RANDOMNESS of Numbers cognitive-semantics DEFINITION VIA Cognition QUERY: WHAT???, NOT HOW?) VS. computer-``science" mindLESS number-crunching (Harrel-Sipser-...) algorithmics Goldreich "PSEUDO-randomness"[Not.AMS(02)] mea-culpa is ONLY via MAXWELL-BOLTZMANN CLASSICAL-STATISTICS(NOT FDQS!!!) "hot-plasma" REPULSION VERSUS Newcomb(1881)-Weyl(1914;1916)-Benford(1938) "NeWBe" logarithmic-law digit-CLUMPING/ CLUSTERING NON-Randomness simple Siegel[AMS Joint.Mtg.(02)-Abs. # 973-60-124] algebraic-inversion to THE QUANTUM and ONLY BEQS preferentially SEQUENTIALLY lower-DIGITS CLUMPING/CLUSTERING with d = 0 BEC, is ONLY VIA Siegel-Baez FUZZYICS=CATEGORYICS (SON OF TRIZ)/"Category-Semantics"(C-S), latter intersection/union of Lawvere(1964)-Siegel(1964)] category-theory (matrix: MORPHISMS V FUNCTORS) "+" cognitive-semantics'' (matrix: ANTONYMS V SYNONYMS) yields Siegel-Baez FUZZYICS=CATEGORYICS/C-S tabular list-format matrix truth-table analytics: MBCS RANDOMNESS TRUTH/EMET!!!

  19. Autologous Matrix-Induced Chondrogenesis (AMIC)

    PubMed Central

    Benthien, J. P.; Behrens, P.

    2010-01-01

    Options for the treatment of cartilage defects include chondral resurfacing with abrasion, debridement, autologous chondrocyte transplantation (ACT), matrix-induced chondrocyte transplantation (MACI), or osteochondral autologous transplantation (OATS). This article describes the new method of autologous matrix-induced chondrogenesis (AMIC), a 1-step procedure combining subchondral microfracture with the fixation of a collagen I/III membrane by a partially autologous fibrin glue. Indications and contraindications are provided; a technical note is given. This method is primarily applied in osteochondral lesions of the knee and ankle joints; other joints may qualify.

  20. Matrix Perturbation Techniques in Structural Dynamics

    NASA Technical Reports Server (NTRS)

    Caughey, T. K.

    1973-01-01

    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.

  1. Algebraic Geometry of Matrix Product States

    NASA Astrophysics Data System (ADS)

    Critch, Andrew; Morton, Jason

    2014-09-01

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

  2. Interaction Picture Density Matrix Quantum Monte Carlo

    E-print Network

    Malone, Fionn D; Shepherd, James J; Lee, D K K; Spencer, J S; Foulkes, W M C

    2015-01-01

    The recently developed density matrix quantum Monte Carlo (DMQMC) algorithm stochastically samples the N -body thermal density matrix and hence provides access to exact properties of many-particle quantum systems at arbitrary temperatures. We demonstrate that moving to the interaction picture provides substantial benefits when applying DMQMC to interacting fermions. In this first study, we focus on a system of much recent interest: the uniform electron gas in the warm dense regime. The basis set incompleteness error at finite temperature is investigated and extrapolated via a simple Monte Carlo sampling procedure. Finally, we provide benchmark calculations for a four-electron system, comparing our results to previous work where possible.

  3. Zymographical techniques for detection of matrix metalloproteinases.

    PubMed

    Iwai, Shinichi; Nakanishi-Ueda, Takako; Armstrong, Donald; Oguchi, Katsuji

    2008-01-01

    Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases associated with extracellular matrix degradation, cellular migration, tissue remodeling, and angiogenesis. The activity of MMPs is regulated by the tissue inhibitors of metalloproteinases (TIMPs). Zymography and reverse zymography are useful to detect MMPs and TIMPs activities from various samples, for example vitreous, retina, plasma, and so on. Sample proteins are separated in substrate containing polyacrylamide gel by electrophoresis. The gel is incubated and then stained with Coomassie Blue. MMPs' activities are detected as clear bands. PMID:19082943

  4. Analytical solutions to matrix diffusion problems

    SciTech Connect

    Kekäläinen, Pekka, E-mail: pekka.kekalainen@helsinki.fi [Laboratory of Radiochemistry, Department of Chemistry, P.O. Box 55, FIN-00014 University of Helsinki (Finland)

    2014-10-06

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

  5. Unifying screw geometry and matrix transformations

    SciTech Connect

    Samuel, A.E.; McAree, P.R.; Hunt, K.H. (Univ. of Melbourne, Parkville (Australia))

    1991-10-01

    Transformation matrices are widely used in robotics for kinematic analysis and trajectory planning. Screw geometry offers better geometric insight into such analyses. In this article the authors unify the two approaches through the use of invariant properties of orthogonal matrices under similarity transformations. They give a complete expression for the finite screw motion in terms of the entires of a 3 {times} 3 dual-number transformation matrix. Their analysis suggests that the finite screw is suitable for trajectory planning, and they develop a concise expression that gives the transformation matrix describing the displacement at each point along the path of the finite screw motion.

  6. Research on graphite reinforced glass matrix composites

    NASA Technical Reports Server (NTRS)

    Bacon, J. F.; Prewo, K. M.

    1977-01-01

    The results of research for the origination of graphite-fiber reinforced glass matrix composites are presented. The method selected to form the composites consisted of pulling the graphite fiber through a slurry containing powdered glass, winding up the graphite fiber and the glass it picks up on a drum, drying, cutting into segments, loading the tape segment into a graphite die, and hot pressing. During the course of the work, composites were made with a variety of graphite fibers in a glass matrix.

  7. An algorithm for computing the matrix exponential

    SciTech Connect

    Li, J.

    1988-01-01

    A necessary condition for use of the Newton interpolation polynomial to compute the matrix exponential is the accurate evaluation of its coefficients, which are divided differences of the exponential function. When the given matrix is real but has complex eigenvalues, there seems to be a fundamental conflict between retaining real arithmetic in this polynomial method and obtaining high accuracy in the coefficients. In this study, the difficulty is investigated in detail and resolved. The resulting technique keeps all the matrices real and confines complex arithmetic to the evaluation of the divided differences.

  8. Novel formulations of CKM matrix renormalization

    NASA Astrophysics Data System (ADS)

    Kniehl, Bernd A.; Sirlin, Alberto

    2009-12-01

    We review two recently proposed on-shell schemes for the renormalization of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix in the Standard Model. One first constructs gauge-independent mass counterterm matrices for the up- and down-type quarks complying with the hermiticity of the complete mass matrices. Diagonalization of the latter then leads to explicit expressions for the CKM counterterm matrix, which are gauge independent, preserve unitarity, and lead to renormalized amplitudes that are non-singular in the limit in which any two quarks become mass degenerate. One of the schemes also automatically satisfies flavor democracy.

  9. Novel formulations of CKM matrix renormalization

    SciTech Connect

    Kniehl, Bernd A. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Lumper Chaussee 149, 22761 Hamburg (Germany); Sirlin, Alberto [Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

    2009-12-17

    We review two recently proposed on-shell schemes for the renormalization of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix in the Standard Model. One first constructs gauge-independent mass counterterm matrices for the up- and down-type quarks complying with the hermiticity of the complete mass matrices. Diagonalization of the latter then leads to explicit expressions for the CKM counterterm matrix, which are gauge independent, preserve unitarity, and lead to renormalized amplitudes that are non-singular in the limit in which any two quarks become mass degenerate. One of the schemes also automatically satisfies flavor democracy.

  10. Polymeric matrix materials for infrared metamaterials

    DOEpatents

    Dirk, Shawn M; Rasberry, Roger D; Rahimian, Kamyar

    2014-04-22

    A polymeric matrix material exhibits low loss at optical frequencies and facilitates the fabrication of all-dielectric metamaterials. The low-loss polymeric matrix material can be synthesized by providing an unsaturated polymer, comprising double or triple bonds; partially hydrogenating the unsaturated polymer; depositing a film of the partially hydrogenated polymer and a crosslinker on a substrate; and photopatterning the film by exposing the film to ultraviolet light through a patterning mask, thereby cross-linking at least some of the remaining unsaturated groups of the partially hydrogenated polymer in the exposed portions.

  11. L-Functions and Random Matrix Theory

    NSDL National Science Digital Library

    This site highlights some of the conjectures and open problems concerning L-functions, with emphasis on the areas in which there has been recent progress using results from Random Matrix Theory. The main page's index links to short articles on such topics as the GUE Hypothesis, Zeros and Primes, and Extremal Problems. The site comes from the American Institute of Mathematics, which has posted these problems to go along with their workshop on L-Functions and Random Matrix Theory, held May 14-18, 2001.

  12. Matrix laser IR-visible image converter

    SciTech Connect

    Lipatov, N I; Biryukov, A S [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

    2006-04-30

    A new type of a focal matrix IR-visible image converter is proposed. The pixel IR detectors of the matrix are tunable microcavities of VCSEL (vertical-cavity surface emitting laser) semiconductor microstructures. The image conversion is performed due to the displacements of highly reflecting cavity mirrors caused by thermoelastic stresses in their microsuspensions appearing upon absorption of IR radiation. Analysis of the possibilities of the converter shows that its sensitivity is 10{sup -3}-10{sup -2} K and the time response is 10{sup -4}-10{sup -3} s. These characteristics determine the practical application of the converter. (laser applications and other topics in quantum electronics)

  13. The origin of chondrules: Constraints from matrix composition and matrix-chondrule complementarity

    NASA Astrophysics Data System (ADS)

    Palme, Herbert; Hezel, Dominik C.; Ebel, Denton S.

    2015-02-01

    One of the major unresolved problems in cosmochemistry is the origin of chondrules, once molten, spherical silicate droplets with diameters of 0.2 to 2 mm. Chondrules are an essential component of primitive meteorites and perhaps of all early solar system materials including the terrestrial planets. Numerous hypotheses have been proposed for their origin. Many carbonaceous chondrites are composed of about equal amounts of chondrules and fine-grained matrix. Recent data confirm that matrix in carbonaceous chondrites has high Si/Mg and Fe/Mg ratios when compared to bulk carbonaceous chondrites with solar abundance ratios. Chondrules have the opposite signature, low Si/Mg and Fe/Mg ratios. In some carbonaceous chondrites chondrules have low Al/Ti ratios, matrix has the opposite signature and the bulk is chondritic. It is shown in detail that these complementary relationships cannot have evolved on the parent asteroid(s) of carbonaceous chondrites. They reflect preaccretionary processes. Both chondrules and matrix must have formed from a single, solar-like reservoir. Consequences of complementarity for chondrule formation models are discussed. An independent origin and/or random mixing of chondrules and matrix can be excluded. Hence, complementarity is a strong constraint for all astrophysical-cosmochemical models of chondrule formation. Although chondrules and matrix formed from a single reservoir, the chondrule-matrix system was open to the addition of oxygen and other gaseous components.

  14. Spectral Design for Matrix Hamiltonians: Different Methods of Constructing of a Matrix Intertwining Operator

    E-print Network

    Andrey V. Sokolov

    2014-07-19

    We study intertwining relations for $n\\times n$ matrix non-Hermitian, in general, one-dimensional Hamiltonians by $n\\times n$ matrix linear differential operators with nondegenerate coefficients at $d/dx$ in the highest degree. Some methods of constructing of $n\\times n$ matrix intertwining operator of the first order of general form are proposed and their interrelation is examined. As example we construct $2\\times2$ matrix Hamiltonian of general form intertwined by operator of the first order with the Hamiltonian with zero matrix potential. It is shown that one can add for the final $2\\times2$ matrix Hamiltonian with respect to the initial matrix Hamiltonian with the help of intertwining operator of the first order either up to two bound states for different energy values or up to two bound states described by vector-eigenfunctions for the same energy value or up to two bound states described by vector-eigenfunction and associated vector-function for the same energy value.

  15. ABCD Matrix Methods for Physical Optics

    NASA Astrophysics Data System (ADS)

    Garton, Adicus

    2003-10-01

    Matrix methods are a poweful and systematic approach to describing wave propogation through optical elements, and can be used to derive solutions to aspects of Gaussian beam propogation, including the paraxial wave approximation. Numerical examples coded in MathCad will be provided to demonstrate the power and utility of the approach.

  16. Nonnegative matrix factorization with quadratic programming

    Microsoft Academic Search

    Rafal Zdunek; Andrzej Cichocki

    2008-01-01

    Nonnegative Matrix Factorization (NMF) solves the following problem: flnd such nonnegative matrices A 2 RI£J + and X 2 R J£K + that Y » = AX, given only Y 2RI£K and the assigned index J (K >> I ‚ J). Basically, the factorization is achieved by alternating minimization of a given cost function subject to nonnega- tivity constraints. In

  17. Density-matrix quantum Monte Carlo method

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

  18. A Random Matrix Model of Black Holes

    E-print Network

    Da Xu

    2008-06-23

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

  19. Derive Workshop Matrix Algebra and Linear Algebra.

    ERIC Educational Resources Information Center

    Townsley Kulich, Lisa; Victor, Barbara

    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,…

  20. Matrix models from operators and topological strings

    E-print Network

    Marino, Marcos

    2015-01-01

    We propose a new family of matrix models whose $1/N$ expansion captures the all-genus topological string on toric Calabi-Yau threefolds. These matrix models are constructed from the trace class operators appearing in the quantization of the corresponding mirror curves. The fact that they provide a non-perturbative realization of the (standard) topological string follows from a recent conjecture connecting the spectral properties of these operators, to the enumerative invariants of the underlying Calabi-Yau threefolds. We study in detail the resulting matrix models for some simple geometries, like local $\\mathbb P^2$ and local $\\mathbb F_2$, and we verify that their weak 't Hooft coupling expansion reproduces the topological string free energies near the conifold singularity. These matrix models are formally similar to those appearing in the Fermi-gas formulation of Chern-Simons-matter theories, and their $1/N$ expansion receives non-perturbative corrections determined by the Nekrasov-Shatashvili limit of the ...

  1. Matrix models from operators and topological strings

    E-print Network

    Marcos Marino; Szabolcs Zakany

    2015-06-23

    We propose a new family of matrix models whose 1/N expansion captures the all-genus topological string on toric Calabi-Yau threefolds. These matrix models are constructed from the trace class operators appearing in the quantization of the corresponding mirror curves. The fact that they provide a non-perturbative realization of the (standard) topological string follows from a recent conjecture connecting the spectral properties of these operators, to the enumerative invariants of the underlying Calabi-Yau threefolds. We study in detail the resulting matrix models for some simple geometries, like local P^2 and local F_2, and we verify that their weak 't Hooft coupling expansion reproduces the topological string free energies near the conifold singularity. These matrix models are formally similar to those appearing in the Fermi-gas formulation of Chern-Simons-matter theories, and their 1/N expansion receives non-perturbative corrections determined by the Nekrasov-Shatashvili limit of the refined topological string.

  2. EUCLIDEAN DISTANCE MATRIX COMPLETION PROBLEMS June ...

    E-print Network

    2010-06-06

    Jun 6, 2010 ... A Euclidean distance matrix is one in which the (i, j) entry specifies the squared .... Proof. This follows from Lemma 2.1 and the fact that V T V = I. .... the minimization algorithm might converge to a minimizer X to (3.3) with high ...

  3. Characterisation of stone matrix asphalt mixtures

    Microsoft Academic Search

    Laith Tashman; Brian Pearson

    2011-01-01

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

  4. Characterisation of stone matrix asphalt mixtures

    Microsoft Academic Search

    Laith Tashman; Brian Pearson

    2012-01-01

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

  5. Preprocessing sparse semidefinite programs via matrix completion

    E-print Network

    2004-07-02

    2003) is a preprocessing method for sparse semidefinite programs based on matrix completion. This article ..... Read the SDP data and determine the aggregate sparsity pattern E. Step 2. Find an ... 5 unnecessary. However, this alternative seems beyond reach due to. 7 .... Criterion (7) has the advantage of just carrying out.

  6. Compensating Mass Matrix Potential Constrained Molecular Dynamics

    E-print Network

    .Jain@jpl.nasa.gov Journal of Computational Physics, Jul, '97 (in press) Subject classification: 65P99, 82A71. KeywordsCompensating Mass Matrix Potential for Constrained Molecular Dynamics Abhinandan Jain Jet: Molecular dynamics, algorithms, simulation. #12; Running head: Compensating Potential for Constrained

  7. SPARSE MATRIX MULTIPLICATION ON AN ASSOCIATIVE PROCESSOR

    E-print Network

    Ginosar, Ran

    is a frequent bottleneck in large scale linear algebra applications, especially in data mining and machine with the emergence of big data, giving rise to very large vector and matrix sizes. Associative Processor (AP technolo- gy in recent years opens the door for reconsidering the APs: The rise of big data pushes

  8. The Fisher information matrix for linear systems

    Microsoft Academic Search

    Raimund J. Ober

    2002-01-01

    Estimation of parameters of linear systems is a problem often encountered in applications. The Cramer Rao lower bound gives a lower bound on the variance of any unbiased parameter estimation method and therefore provides an important tool in the assessment of a parameter estimation method and for experimental design. Here we study the calculation of the Fisher information matrix, the

  9. OPTIMIZATION BY DIRECT SEARCH IN MATRIX COMPUTATIONS

    Microsoft Academic Search

    NICHOLAS J. HIGHAMt

    1993-01-01

    A direct search method attempts to maximize a function f l R using function values only. Many questions about the stability and accuracy of algorithms in matrix computations can be expressed in terms of the maximum value ofsome easily computable function f. For a variety of algorithms it is shown that direct search is capable of revealing instability or poor

  10. Symmetrical parametrizations of the lepton mixing matrix

    SciTech Connect

    Rodejohann, W. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, 69029 Heidelberg (Germany); Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

    2011-10-01

    Advantages of the original symmetrical form of the parametrization of the lepton mixing matrix are discussed. It provides a conceptually more transparent description of neutrino oscillations and lepton number violating processes like neutrinoless double beta decay, clarifying the significance of Dirac and Majorana phases. It is also ideal for parametrizing scenarios with light sterile neutrinos.

  11. Critical state of sand matrix soils.

    PubMed

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

    2014-01-01

    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

  12. Human Resources Security Access Matrix Function Training

    E-print Network

    Wu, Shin-Tson

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

  13. Matrix optimisation for hazardous organic waste sorption

    Microsoft Academic Search

    I. Natali Sora; R. Pelosato; L. Zampori; D. Botta; G. Dotelli; M. Vitelli

    2005-01-01

    Organophilic clays have proven to be interesting intermediates for the definitive stabilization of hazardous organic waste in cement matrix. In the present work, the influence of quaternary ammonium salt structure on the organophilic clay load capacity and the interaction type with the organic waste were investigated. Commercial organophilic montmorillonite clays, containing an ammonium quaternary salt with methyl and long chain

  14. DIFFERENTIAL POLYNOMIAL RINGS OF TRIANGULAR MATRIX RINGS

    Microsoft Academic Search

    H. GHAHRAMANI; A. MOUSSAVI

    2008-01-01

    Let R,S be rings with identity and M be a unitary (R,S)-bimodule. We characterize homomorphisms and derivations of the generalized matrix ring T = R M 0 S , and provide a tri- angular representation of the dierential polynomial ring T( ;d).

  15. Evaluation of the Matrix Project. Interchange 77.

    ERIC Educational Resources Information Center

    McIvor, Gill; Moodie, Kristina

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

  16. On matrix mortality in low Olivier Bournez

    E-print Network

    Branicky, Michael S.

    Chapter 1 On matrix mortality in low dimensions Olivier Bournez and Michael Branicky VERIMAG of the problem A set F = {A1, . . . , Am} of n × n matrices is said to be mortal if there exist integers k 1 to be k-length mortal. We use Mortality(n) to denote the class of decision problems "Is a given set F

  17. Classifying Faces with Nonnegative Matrix Factorization

    Microsoft Academic Search

    David Guillamet; Jordi Vitria

    2002-01-01

    This paper addresses the well-known problem of recognizing faces under several unfavorable situa- tions. We have analyzed situations with changes in expression, in illumination and occlusions such as faces wearing sunglasses or scarfs. We have intro- duced the use of the Non-negative Matrix Factor- ization (NMF) technique in the context of classifica- tion of face images and we have directly

  18. Machining of aluminium based metal matrix composites

    Microsoft Academic Search

    S. Barnes; I. R. Pashby

    1995-01-01

    Although metal matrix composites (MMCs) are generally regarded as extremely difficult to machine, it is also acknowledged that their machining behaviour is not fully understood. The work reviewed here confirms this widely held view but also suggests that the machinability of these materials can be improved by appropriate selection of the reinforcing phase, its volume fraction, size, and morphology as

  19. Matrix, sieve, binder developments improve FCC catalysts

    SciTech Connect

    Upson, L.L.; Lawson, R.J. (UOP, Des Plaines, IL (US)); Cormier, W.E. (Katalistiks, Baltimore, MD (US)); Baars, F.J. (Katalistiks B.V., Leiderdorp (NL))

    1990-10-01

    This paper discusses FCC catalyst developments since the merger of UOP and Katalistiks. These developments include catalyst matrix improvements, zeolite improvements, and better attrition resistance. During the last 2 years, these developments have been tested in the laboratory, pilot plants, and in operating refineries.

  20. Fredholm determinants, differential equations and matrix models

    Microsoft Academic Search

    Craig A. Tracy; Harold Widom

    1994-01-01

    Orthogonal polynomial random matrix models ofN×N hermitian matrices lead to Fredholm determinants of integral operators with kernel of the form (?(x)?(y)??(x)?(y))\\/x?y. This paper is concerned with the Fredholm determinants of integral operators having kernel of this form and where the underlying set is the union of intervals\\u000a

  1. Computing integrals involving the matrix exponential

    Microsoft Academic Search

    C. Van Loan

    1978-01-01

    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.

  2. Multisensor data fusion for OD matrix estimation

    Microsoft Academic Search

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

    2009-01-01

    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

  3. Matrix Elasticity Directs Stem Cell Lineage Specification

    E-print Network

    Discher, Dennis

    and also for therapeu- tic uses of stem cells. INTRODUCTION Adult stem cells, as part of normalMatrix Elasticity Directs Stem Cell Lineage Specification Adam J. Engler,1,2 Shamik Sen,1,2 H. Lee.06.044 SUMMARY Microenvironments appear important in stem cell lineage specification but can be difficult

  4. Scattering matrix approach to STW resonators

    Microsoft Academic Search

    Waldemar Soluch

    2002-01-01

    The scattering matrix method was used for the analysis of surface transverse wave (STW) resonators on quartz. An expression for the transfer function of the resonators with different numbers of electrodes in the reflectors was derived. It was found that, for a proper ratio of these numbers, the spurious signal level below the resonance frequency can be lowered. The STW

  5. Light weight polymer matrix composite material

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  6. Science Unlimited: Grades K-6 Competency Matrix.

    ERIC Educational Resources Information Center

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

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

  7. Measuring Sparticles with the Matrix Element

    SciTech Connect

    Alwall, Johan [SLAC, Stanford University, Stanford, CA 94309 (United States); Department of Physics, National Taiwan University, Taipei, Taiwan (China); Freitas, Ayres [Department of Physics and Astronomy, University of Pittsburgh, PA 15260 (United States); Mattelaer, Olivier [INFN, Sezione di Roma Tre, and Universita degli Studi Roma Tre, 00146, Roma (Italy); Universite Catholique de Louvain, 2, Chemin du Cyclotron, 1348 Louvain-la-Neuve (Belgium)

    2010-02-10

    We apply the Matrix Element Method (MEM) to mass determination of squark pair production with direct decay to quarks and LSP at the LHC, showing that simultaneous mass determination of squarks and LSP is possible. We furthermore propose methods for inclusion of QCD radiation effects in the MEM.

  8. Inverter Matrix for the Clementine Mission

    NASA Technical Reports Server (NTRS)

    Buehler, M. G.; Blaes, B. R.; Tardio, G.; Soli, G. A.

    1994-01-01

    An inverter matrix test circuit was designed for the Clementine space mission and is built into the RRELAX (Radiation and Reliability Assurance Experiment). The objective is to develop a circuit that will allow the evaluation of the CMOS FETs using a lean data set in the noisy spacecraft environment.

  9. FIR multichannel identification using weighted cumulant matrix

    Microsoft Academic Search

    Jing Liang; Zhi Ding

    2000-01-01

    Blind identification of FIR multichannel using higher-order statistics (HOS) is investigated. A new linear approach is proposed which generalizes the weighted slices method for single FIR channel estimation. By finding the proper linear combinations, channel response is obtained from the weighted cumulant matrix with Toeplitz structure. This general algorithm works for both single user and multiuser scenario. It relaxes the

  10. A contribution to matrix quadratic equations

    Microsoft Academic Search

    V. Kucera

    1972-01-01

    The well-known matrix algebraic equation of the optimal control and filtering theory is considered. A necessary and sufficient condition for its solution to yield an optimal as well as asymptotically stable closed-loop system is given. The condition involves the concepts of stabilizability and detectability.

  11. Matrix compliance and the regulation of cytokinesis.

    PubMed

    Sambandamoorthy, Savitha; Mathew-Steiner, Shomita; Varney, Scott; Zuidema, Jonathan M; Gilbert, Ryan J; Van De Water, Livingston; LaFlamme, Susan E

    2015-01-01

    Integrin-mediated cell adhesion to the ECM regulates many physiological processes in part by controlling cell proliferation. It is well established that many normal cells require integrin-mediated adhesion to enter S phase of the cell cycle. Recent evidence indicates that integrins also regulate cytokinesis. Mechanical properties of the ECM can dictate entry into S phase; however, it is not known whether they also can affect the successful completion of cell division. To address this issue, we modulated substrate compliance using fibronectin-coated acrylamide-based hydrogels. Soft and hard substrates were generated with approximate elastic moduli of 1600 and 34,000 Pascals (Pa) respectively. Our results indicate that dermal fibroblasts successfully complete cytokinesis on hard substrates, whereas on soft substrates, a significant number fail and become binucleated. Cytokinesis failure occurs at a step following the formation of the intercellular bridge connecting presumptive daughter cells, suggesting a defect in abscission. Like dermal fibroblasts, mesenchymal stem cells require cell-matrix adhesion for successful cytokinesis. However, in contrast to dermal fibroblasts, they are able to complete cytokinesis on both hard and soft substrates. These results indicate that matrix stiffness regulates the successful completion of cytokinesis, and does so in a cell-type specific manner. To our knowledge, our study is the first to demonstrate that matrix stiffness can affect cytokinesis. Understanding the cell-type specific contribution of matrix compliance to the regulation of cytokinesis will provide new insights important for development, as well as tissue homeostasis and regeneration. PMID:26002930

  12. Assembly Line Balancing with a Precedence Matrix

    Microsoft Academic Search

    Thomas R. Hoffmann

    1963-01-01

    Assembly line balancing consists of assigning work elements, which are subject to sequencing restrictions, along an assembly line in an optimal manner. The procedure presented in this paper leads to optimal line balances by operation on a matrix of zeros and ones called a \\

  13. Generalized Nonnegative Matrix Approximations with Bregman Divergences

    Microsoft Academic Search

    Inderjit S. Dhillon; Suvrit Sra

    2005-01-01

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

  14. Nonnegative Matrix Approximation: Algorithms and Applications

    Microsoft Academic Search

    Suvrit Sra; Inderjit S. Dhillon

    Low dimensional data representations are crucial to numerous applications in machine learning, statis- tics, and signal processing. Nonnegative matrix approximation (NNMA) is a method for dimensionality reduction that respects the nonnegativity of the input data while constructin g a low-dimensional approx- imation. NNMA has been used in a multitude of applications, though without commensurate theoretical development. In this report we

  15. Affine connections for the Cartesian stiffness matrix

    Microsoft Academic Search

    Milos Zefran; Vijay Kumar

    1997-01-01

    We study the 6×6 Cartesian stiffness matrix. We show that the stiffness of a rigid body subjected to conservative forces and moments is described by a (0,2) tensor which is the Hessian of the potential function. The key observation of the paper is that since the Hessian depends on the choice of an affine connection in the task space, so

  16. On the asymptotic complexity of matrix multiplication

    Microsoft Academic Search

    D. Coppersmith; S. Winograd

    1981-01-01

    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

  17. Matrix vesicles: Are they anchored exosomes?

    PubMed

    Shapiro, Irving M; Landis, William J; Risbud, Makarand V

    2015-10-01

    Numerous studies have documented that matrix vesicles are unique extracellular membrane-bound microparticles that serve as initial sites for mineral formation in the growth plate and most other vertebrate mineralizing tissues. Microparticle generation is not confined to hard tissues, as cells in soft tissues generate similar structures; numerous studies have shown that a common type of extracellular particle, termed an exosome, a product of the endosomal pathway, shares many characteristics of matrix vesicles. Indeed, analyses of size, morphology and lipid and protein content indicate that matrix vesicles and exosomes are homologous structures. Such a possibility impacts our understanding of the biogenesis, processing and function of matrix vesicles (exosomes) in vertebrate hard tissues and explains in part how cells control the earliest stages of mineral deposition. Moreover, since exosomes influence a spectrum of functions, including cell-cell communication, it is suggested that this type of microparticle may provide a mechanism for the transfer of signaling molecules between cells within the growth plate and thereby regulate endochondral bone development and formation. PMID:25980744

  18. An auxiliary resonant soft switching matrix converter

    Microsoft Academic Search

    M. J. Bland; J. C. Clare; P. W. Wheeler; L. Empringham; M. Apap

    2004-01-01

    This paper is concerned with the design, construction and testing of a 3-phase to 3-phase soft switching matrix converter. Two auxiliary soft switching circuits are added to each output phase in order to achieve soft switching without significantly increasing the conduction losses. The converter operation is discussed with reference to theoretical waveforms. The distribution of the switching losses with respect

  19. Bayesian Inference with Probability Matrix Decomposition Models.

    ERIC Educational Resources Information Center

    Meulders, Michel; De Boeck, Paul; Van Mechelen, Iven; Gelman, Andrew; Maris, Eric

    2001-01-01

    Presents a fully Bayesian analysis for the Probability Matrix Decomposition (PMD) model using the Gibbs sampler. Identifies the advantages of this approach and illustrates the approach by applying the PMD model to opinions of respondents from different countries concerning the possibility of contracting AIDS in a specific situation. (SLD)

  20. Reduced matrix elements in nuclear shell theory

    Microsoft Academic Search

    V. Kembhavi

    1961-01-01

    Using harmonic oscillator wave functions, reduced matrix elements were ; expressed in terms of Talmi integrals and 3Fâ series. The B coefficients ; of Brody, Jacob, and Moshinsky are shown to be related to 3Fâ series, and ; some recurrence relations for the B coefficients are obtained. A table of useful ; B coefficients is presented. (auth);

  1. Characterizing Topological Order with Matrix Product Operators

    E-print Network

    Mehmet Burak ?ahino?lu; Dominic Williamson; Nick Bultinck; Michael Mariën; Jutho Haegeman; Norbert Schuch; Frank Verstraete

    2014-09-07

    One of the most striking features of quantum phases that exhibit topological order is the presence of long range entanglement that cannot be detected by any local order parameter. The formalism of projected entangled-pair states is a natural framework for the parameterization of the corresponding ground state wavefunctions, in which the full wavefunction is encoded in terms of local tensors. Topological order is reflected in the symmetries of these tensors, and we give a characterization of those symmetries in terms of matrix product operators acting on the virtual level. This leads to a set of algebraic rules characterizing states with topological quantum order. The corresponding matrix product operators fully encode all topological features of the theory, and provide a systematic way of constructing topological states. We generalize the conditions of $\\mathsf{G}$ and twisted injectivity to the matrix product operator case, and provide a complete picture of the ground state manifold on the torus. As an example, we show how all string-net models of Levin and Wen fit within this formalism, and in doing so provide a particularly intuitive interpretation of the pentagon equation for F-symbols as the pulling of certain matrix product operators through the string-net tensor network. Our approach paves the way to finding novel topological phases beyond string-nets, and elucidates the description of topological phases in terms of entanglement Hamiltonians and edge theories.

  2. Symmetry in Matrix Models Pierre Flener

    E-print Network

    Walsh, Toby

    Symmetry in Matrix Models Pierre Flener , Alan Frisch ¡ , Brahim Hnich ¢ , Zeynep Kiziltan models, sym- metry is an important feature. We study and generalise symmetry-breaking techniques with symmetry in such models in a uniform way. We thereby reduce the burden on the user of eliminating symmetry

  3. Symmetry-Breaking Constraints for Matrix Models

    E-print Network

    Flener, Pierre

    Symmetry-Breaking Constraints for Matrix Models Zeynep Kiziltan1 and Barbara M. Smith2 1 Department their rows and/or columns. Eliminating all such symmetry can be very costly as there are in general exponentially many symme- tries. Cost-effective methods have been proposed to break much of the symmetry

  4. Matrix Acidizing Parallel Core Flooding Apparatus 

    E-print Network

    Ghosh, Vivek

    2013-07-23

    , assemble, and test a matrix acidizing parallel core flooding apparatus. The apparatus was rated for 5,000 psi and 250 ?F. The design uses 36 valves to configure small, medium, and large core holders. The key feature is the ability to run parallel core... ................................................................................. 27 2.10 Nitrogen Source ............................................................................................ 29 2.11 Fraction Collector ......................................................................................... 30 2.12 Valve...

  5. PLANT DATA VISUALIZATION USING NONNEGATIVE MATRIX FACTORIZATION

    Microsoft Academic Search

    J. Tapson; J. R. Greene

    Non-negative matrix factorization (NMF) is a method for dimensionality reduction and simplification of large data sets. Unlike tools such as principal components analysis (PCA) and factor analysis , NMF produces basis vectors that correspond to perceptible features in the original data. This is particularly useful when working with data where visual interpretation of the simplified representation is required. Typical data

  6. Critical State of Sand Matrix Soils

    PubMed Central

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

    2014-01-01

    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

  7. Stability of Selected Chromophores in Biopolymer Matrix

    Microsoft Academic Search

    Ileana Rau; Alexandrina Tane; Roxana Zgarian; Aurelia Meghea; James G. Grote; Francois Kajzar

    2012-01-01

    Photochemical and thermal stability of thin films formed from selected optically responsive chromophores embedded in deoxyribonucleic acid (DNA), Collagen and in the complex formed by DNA biopolymer and the surfactant hexadecyl ammonium (CTMA) matrix was studied by UV-VIS and compared with that observed when using some synthetic polymers (polymethylmetacrylate – PMMA, polycarbonate – PC). In particular the influence of external

  8. Nonnegative Matrix Factorization for Spectral Data Analysis

    E-print Network

    Plemmons, Robert J.

    , and asteroids, in orbit around the earth. In this paper we develop an effective nonnegative matrix factorization mining, space object identification and classification. 1 Introduction We are concerned with methods for linear algebraists. It has been shown to be an especially effective tool in several areas of data mining

  9. Overview: Tradi'onally matrix assisted laser

    E-print Network

    spectrometry MALDI MS has been used for high molecular weight analytes (>1000Da).1 · Small molecule applica'ons of MALDI MS have suffered from matrix interference.2 a tradi'onal MALDI target. 1L of analyte solu'on was then spoWed onto the metal

  10. A direct control method for matrix converters

    Microsoft Academic Search

    Peter Mutschler; Matthias Marcks

    2002-01-01

    Until now, direct control methods have been mainly investigated and used in conjunction with voltage source converters. In this paper, the authors develop a direct current control method for matrix converters. There are two objectives for the direct current control: the desired current has to be impressed into the load, and the current, drawn from the mains, should be in

  11. New modulation method for matrix converters

    Microsoft Academic Search

    Christian Klumpner; Frede Blaabjerg; Ion Boldea; Peter Nielsen

    2006-01-01

    This paper presents a new modulation method for matrix converters based on the indirect modulation model. During the switching period, the proposed modulation method uses a combination of only one active vector and a zero vector in the inversion stage to achieve minimum flux error, whereas in the rectification stage, a single current vector is selected according to the angle

  12. Displacement angle control of matrix converter

    Microsoft Academic Search

    Jun Oyama; Xiarong Xia; Tsuyoshi Higuchi; Eiji Yamada

    1997-01-01

    The authors previously proposed and discussed a control method for matrix power converters in which instantaneous input voltages are used. The method can generate output voltages of 0.866 times the supply voltage. Control input current and output voltage of sinusoidal waveform can be obtained and can compensate the effect of fluctuation, asymmetry or harmonics in both the output voltage and

  13. CHAPTER TEN Matrix Regulation of Tumor-

    E-print Network

    Kumar, Sanjay

    CHAPTER TEN Matrix Regulation of Tumor- Initiating Cells Sophie Y. Wong, Sanjay Kumar Department.1 What are tumor-initiating cells? 244 1.2 Significance of TICs 245 2. Identification and Isolation of mechanotransduction 250 4. Conclusion 251 References 252 Abstract The recognition that the progression of many tumors

  14. Determination of Matrix Diffusion Properties of Granite

    SciTech Connect

    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

    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)

  15. Regulation of corneal stroma extracellular matrix assembly.

    PubMed

    Chen, Shoujun; Mienaltowski, Michael J; Birk, David E

    2015-04-01

    The transparent cornea is the major refractive element of the eye. A finely controlled assembly of the stromal extracellular matrix is critical to corneal function, as well as in establishing the appropriate mechanical stability required to maintain corneal shape and curvature. In the stroma, homogeneous, small diameter collagen fibrils, regularly packed with a highly ordered hierarchical organization, are essential for function. This review focuses on corneal stroma assembly and the regulation of collagen fibrillogenesis. Corneal collagen fibrillogenesis involves multiple molecules interacting in sequential steps, as well as interactions between keratocytes and stroma matrix components. The stroma has the highest collagen V:I ratio in the body. Collagen V regulates the nucleation of protofibril assembly, thus controlling the number of fibrils and assembly of smaller diameter fibrils in the stroma. The corneal stroma is also enriched in small leucine-rich proteoglycans (SLRPs) that cooperate in a temporal and spatial manner to regulate linear and lateral collagen fibril growth. In addition, the fibril-associated collagens (FACITs) such as collagen XII and collagen XIV have roles in the regulation of fibril packing and inter-lamellar interactions. A communicating keratocyte network contributes to the overall and long-range regulation of stromal extracellular matrix assembly, by creating micro-domains where the sequential steps in stromal matrix assembly are controlled. Keratocytes control the synthesis of extracellular matrix components, which interact with the keratocytes dynamically to coordinate the regulatory steps into a cohesive process. Mutations or deficiencies in stromal regulatory molecules result in altered interactions and deficiencies in both transparency and refraction, leading to corneal stroma pathobiology such as stromal dystrophies, cornea plana and keratoconus. PMID:25819456

  16. On the Unification of Random Matrix Theories

    E-print Network

    Rupert A Small

    2015-03-31

    A new method involving particle diagrams is introduced and developed into a rigorous framework for carrying out embedded random matrix calculations. Using particle diagrams and the attendant methodology including loop counting it becomes possible to calculate the fourth, sixth and eighth moments of embedded ensembles in a straightforward way. The method, which will be called the method of particle diagrams, proves useful firstly by providing a means of classifying the components of moments into particle paths, or loops, and secondly by giving a simple algorithm for calculating the magnitude of combinatorial expressions prior to calculating them explicitly. By confining calculations to the limit case $m \\ll l\\to\\infty$ this in many cases provides a sufficient excuse not to calculate certain terms at all, since it can be foretold using the method of particle diagrams that they will not survive in this asymptotic regime. Applying the method of particle diagrams washes out a great deal of the complexity intrinsic to the problem, with sufficient mathematical structure remaining to yield limiting statistics for the unified phase space of random matrix theories. Finally, since the unified form of random matrix theory is essentially the set of all randomised k-body potentials, it should be no surprise that the early statistics calculated for the unified random matrix theories in some instances resemble the statistics currently being discovered for quantum spin hypergraphs and other randomised potentials on graphs [HMH05,ES14,KLW14]. This is just the beginning for studies into the field of unified random matrix theories, or embedded ensembles, and the applicability of the method of particle diagrams to a wide range of questions as well as to the more exotic symmetry classes, such as the symplectic ensembles, is still an area of open-ended research.

  17. Pendulum impact resistance of tungsten fiber/metal matrix composites.

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

    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.

  18. Dentin matrix degradation by host matrix metalloproteinases: inhibition and clinical perspectives toward regeneration

    PubMed Central

    Chaussain, Catherine; Boukpessi, Tchilalo; Khaddam, Mayssam; Tjaderhane, Leo; George, Anne; Menashi, Suzanne

    2013-01-01

    Bacterial enzymes have long been considered solely accountable for the degradation of the dentin matrix during the carious process. However, the emerging literature suggests that host-derived enzymes, and in particular the matrix metalloproteinases (MMPs) contained in dentin and saliva can play a major role in this process by their ability to degrade the dentin matrix from within. These findings are important since they open new therapeutic options for caries prevention and treatment. The possibility of using MMP inhibitors to interfere with dentin caries progression is discussed. Furthermore, the potential release of bioactive peptides by the enzymatic cleavage of dentin matrix proteins by MMPs during the carious process is discussed. These peptides, once identified, may constitute promising therapeutical tools for tooth and bone regeneration. PMID:24198787

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

    E-print Network

    Chung, Deborah D.L.

    and is thus valuable for lightning protection, which is also needed for aircraft. Carbon-matrix composites compo- site that is capable of EMI shielding is particularly needed for aircraft, which houses

  20. Extracellular Matrix Molecules Improve Periodontal Ligament Cell Adhesion to Anorganic Bone Matrix

    Microsoft Academic Search

    T. E. Lallier; R. Yukna; R. L. Moses

    2001-01-01

    Bone replacement graft (BRG) materials are used in periodontal therapy to encourage new bone formation. Extracellular matrix proteins may improve periodontal ligament fibroblast (PDLF) attachment to these materials. We demonstrate that PDLFs adhere well to the extracellular matrix (ECM) proteins fibronectin, vitronectin, laminin, and collagen types I and IV. PDLFs express numerous ECM-receptor integrin subunit transcripts (?1, a2, a3, a4,

  1. Angiogenesis: vascular remodeling of the extracellular matrix involves metalloproteinases.

    PubMed

    Heissig, Beate; Hattori, Koichi; Friedrich, Matthias; Rafii, Shahin; Werb, Zena

    2003-03-01

    Endothelial cell invasion is an essential event during angiogenesis (the formation of new blood vessels). This process involves the degradation of the extracellular matrix, the basement membrane, and interstitial stroma, and is governed by the activation of matrix metalloproteinases. However, the contribution of matrix metalloproteinases in angiogenesis is much more complicated. Tumor growth above a certain size is dependent on new vessels. A number of studies have demonstrated that treating tumors with matrix metalloproteinase inhibitors results in tumor reduction and a decrease in tumor angiogenesis. Matrix metalloproteinases as sole matrix eaters or degraders is a matter of the past. Not only tumor cells but more importantly bystander cells such as stromal cells produce matrix metalloproteinases. Matrix metalloproteinases therefore are also part of the pathologic microenvironment in different diseases. This enzymatic microenvironment dictates the endothelial cell fate, the angiogenic switch, and finally angiogenesis. During recent years, the role of matrix metalloproteinases has expanded, and their function as modulators of biologically active signaling molecules has drawn much attention. Depending on their substrate (growth factors or their receptors, extracellular matrix components, and angiogenic factors), matrix metalloproteinase activation results in the generation of proangiogenic or antiangiogenic factors. These data challenge the old concept that matrix metalloproteinases are simply proangiogenic. The knowledge of the local enzymatic profile and what, where, and how matrix metalloproteinases are involved in angiogenesis of tumors or other diseases will help design future therapeutic strategies better reflecting the complexity of the underlying biologic process of angiogenesis. PMID:12579040

  2. Advances in thermoplastic matrix composite materials

    SciTech Connect

    Newaz, G.M.

    1989-01-01

    Accounts are given of the development status of thermoplastic composite processing methods, as well as their current thermal and mechanical behavior and delamination properties. Attention is given to the thermoplastic coating of carbon fibers, pultrusion-process modeling, the high temperature behavior of graphite/PEEK, the thermal conductivity of composites for electronic packaging, a FEM analysis of mode I and II thermoplastic-matrix specimens, and reinforcements' resin-impregnation behavior during thermoplastic composite manufacture. Also discussed are the mechanical properties of carbon fiber/PEEK for structural applications, moisture-content mechanical property effects in PPS-matrix composites, the interlaminar fracture toughness of thermoplastic composites, and thermoplastic composite delamination growth under elevated temperature cyclic loading.

  3. Ceramic fiber ceramic matrix filter development

    SciTech Connect

    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

    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.

  4. Matrix product states for gauge field theories

    E-print Network

    Boye Buyens; Jutho Haegeman; Karel Van Acoleyen; Henri Verschelde; Frank Verstraete

    2014-11-03

    The matrix product state formalism is used to simulate Hamiltonian lattice gauge theories. To this end, we define matrix product state manifolds which are manifestly gauge invariant. As an application, we study 1+1 dimensional one flavour quantum electrodynamics, also known as the massive Schwinger model, and are able to determine very accurately the ground state properties and elementary one-particle excitations in the continuum limit. In particular, a novel particle excitation in the form of a heavy vector boson is uncovered, compatible with the strong coupling expansion in the continuum. We also study non-equilibrium dynamics by simulating the real-time evolution of the system induced by a quench in the form of a uniform background electric field.

  5. Parallel matrix multiplication on the Connection Machine

    NASA Technical Reports Server (NTRS)

    Tichy, Walter F.

    1988-01-01

    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.

  6. Advanced ceramic matrix composites for TPS

    NASA Technical Reports Server (NTRS)

    Rasky, Daniel J.

    1992-01-01

    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.

  7. Visualization of a stock market correlation matrix

    NASA Astrophysics Data System (ADS)

    Rea, Alethea; Rea, William

    2014-04-01

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

  8. Chondrons and the pericellular matrix of chondrocytes.

    PubMed

    Zhang, Zijun

    2015-06-01

    In cartilage, chondrocytes are embedded within an abundant extracellular matrix (ECM). A typical chondron consists of a chondrocyte and the immediate surrounding pericellular matrix (PCM). The PCM has a patent structure, defined molecular composition, and unique physical properties that support the chondrocyte. Given this spatial position, the PCM is pivotal in mediating communication between chondrocytes and the ECM and, thus, plays a critical role in cartilage homeostasis. The biological function and mechanical properties of the PCM have been extensively studied, mostly in the form of chondrons. This review intends to summarize recent progress in chondron and chondrocyte PCM research, with emphasis on the re-establishment of the PCM by isolated chondrocytes or mesenchymal stem cells during chondrogenic differentiation, and the effects of the PCM on cartilage tissue formation. PMID:25366980

  9. Pfaffian Expressions for Random Matrix Correlation Functions

    NASA Astrophysics Data System (ADS)

    Nagao, Taro

    2007-12-01

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

  10. Automation of the matrix element reweighting method

    E-print Network

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

    2011-02-01

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

  11. How inert is an argon matrix?

    NASA Astrophysics Data System (ADS)

    Hallamasek, D.; Babka, E.; Knözinger, E.

    1997-06-01

    SF 6 as an IR-active bulk and surface probe indicates the presence of porosity and diverse local environments in an Ar matrix prepared under experimental conditions favouring perfect isolation of guest molecules. This is in agreement with previous X-ray and neutron diffraction studies. A huge variety of different cage and surface sites are generated during formation of the matrix. On annealing, two generally contradictory phenomena occur: (a) perfectly isolated monomer species are enriched by sealing the micropores through which the monomers penetrated in the preceding deposition process; (b) cluster formation of SF 6 probes takes place, resulting in the appearance of extended crystalline phases in the larger pores and on the surfaces.

  12. Matrix metalloproteinase-9 and autoimmune diseases.

    PubMed

    Ram, Maya; Sherer, Yaniv; Shoenfeld, Yehuda

    2006-07-01

    Matrix metalloproteinases (also named matrixin or MMPs) are a major group of enzymes that regulate cell-matrix composition by using zinc for their proteolytic activities. They are essential for various normal biological processes such as embryonic development, morphogenesis, reproduction tissue resorption, and remodeling. Metalloproteinases also play a role in pathological processes including inflammation, arthritis, cardiovascular diseases, pulmonary diseases and cancer. Herein we review the involvement of MMP-9 in a variety of autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, systemic sclerosis, rheumatoid arthritis, multiple sclerosis, polymyositis and atherosclerosis. MMP-9 plays either a primary or secondary role in each one of those autoimmune diseases by its up or down-regulation. It is not expressed constantly but rather is induced or suppressed by many regulating molecules. This feature of MMP-9 along with its involvement in disease pathogenesis turns it into a target for therapy of autoimmune diseases. PMID:16652230

  13. Covariant method for soliton matrix elements

    NASA Astrophysics Data System (ADS)

    Ralston, John P.

    1986-01-01

    We construct field-theory wave functions for soliton and other collective states in field theory. The formalism is covariant, incorporates zero modes, and the states can be directly related to states postulated in the standard Hamiltonian quantization procedures. By explicitly constructing the states using a generalized coherent-state expansion, we present the calculation of matrix elements of functions of operators in a general linearization scheme and reduce such calculations to ordinary functions of classical fields. The results include the dependence of matrix elements on a regularization scale ?2, momentum transfer q?, the overlap of states having different position indices, and the classical configuration. We construct momentum eigenstates and examine the semiclassical limit ?-->0. Although most of the analysis is expressed in free-field or plane-wave modes for definiteness, the generalization to modes defined by an arbitrary linearization procedure is presented. We also discuss the separation of divergences from zero-point fluctuations versus classical divergences from topological sectors.

  14. Influence of Binder in Iron Matrix Composites

    SciTech Connect

    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

    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.

  15. Influence of Binder in Iron Matrix Composites

    NASA Astrophysics Data System (ADS)

    Shamsuddin, S.; Jamaludin, S. B.; Hussain, Z.; Ahmad, Z. A.

    2010-03-01

    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° 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.

  16. Rolling Element Bearing Stiffness Matrix Determination (Presentation)

    SciTech Connect

    Guo, Y.; Parker, R.

    2014-01-01

    Current theoretical bearing models differ in their stiffness estimates because of different model assumptions. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A numerical method is developed to determine the full bearing stiffness matrix corresponding to two radial, one axial, and two angular coordinates; the rotation about the shaft axis is free by design. This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods. The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.

  17. Graphite matrix materials for nuclear waste isolation

    NASA Astrophysics Data System (ADS)

    Morgan, W. C.

    1981-06-01

    Manufacturing processes are reviewed herein, with primary emphasis on those processes which might be used to produce a graphic matrix for the waste forms. The approach involves the low temperature compaction of a finely ground powder produced from graphitized petroleum coke. The resultant compacts should have fairly good strength, low permeability to both liquids and gases, and anisotropic physical properties. In particular, the anisotropy of the thermal expansion coefficients and the thermal conductivity should be advantageous for this application. With two possible exceptions, the graphite matrix appears to be superior t the metal alloy matrices which have been recommended in prior studies. The two possible exceptions are the requirements on strength and permeability; both requirements will be strongly influenced by the containment design, including the choice of materials and the waste form, of the multibarrier package.

  18. Matrix metalloproteinase interactions with collagen and elastin

    PubMed Central

    Van Doren, Steven R.

    2015-01-01

    Most abundant in the extracellular matrix are collagens, joined by elastin that confers elastic recoil to the lung, aorta, and skin. These fibrils are highly resistant to proteolysis but can succumb to a minority of the matrix metalloproteinases (MMPs). Considerable inroads to understanding how such MMPs move to the susceptible sites in collagen and then unwind the triple helix of collagen monomers have been gained. The essential role in unwinding of the hemopexin-like domain of interstitial collagenases or the collagen binding domain of gelatinases is highlighted. Elastolysis is also facilitated by the collagen binding domain in the cases of MMP-2 and MMP-9, and remote exosites of the catalytic domain in the case of MMP-12. PMID:25599938

  19. Matrix representation of the time operator

    NASA Astrophysics Data System (ADS)

    Bender, Carl M.; Gianfreda, Mariagiovanna

    2012-06-01

    In quantum mechanics the time operator ? satisfies the commutation relation [?, H] = i, and thus it may be thought of as being formally canonically conjugate to the Hamiltonian H. The time operator associated with a given Hamiltonian H is not unique because one can replace ? by ? + ?hom, where ?hom satisfies the homogeneous condition [?hom, H] = 0. To study this nonuniqueness the matrix elements of ? for the harmonic-oscillator Hamiltonian are calculated in the eigenstate basis. This calculation requires the summation of divergent series, and the summation is accomplished by using zeta-summation techniques. It is shown that by including appropriate homogeneous contributions, the matrix elements of ? simplify dramatically. However, it is still not clear whether there is an optimally simple representation of the time operator.

  20. The super period matrix with Ramond punctures

    NASA Astrophysics Data System (ADS)

    Witten, Edward

    2015-06-01

    We generalize the super period matrix of a super Riemann surface to the case that Ramond punctures are present. For a super Riemann surface of genus g with 2 r Ramond punctures, we define, modulo certain choices that generalize those in the classical theory (and assuming a certain generic condition is satisfied), a g | r × g | r period matrix that is symmetric in the Z2-graded sense. As an application, we analyze the genus 2 vacuum amplitude in string theory compactifications to four dimensions that are supersymmetric at tree level. We find an explanation for a result that has been found in orbifold examples in explicit computations by D'Hoker and Phong: with their integration procedure, the genus 2 vacuum amplitude always vanishes "pointwise" after summing over spin structures, and hence is given entirely by a boundary contribution.

  1. The Extracellular Matrix: Not Just Pretty Fibrils

    NSDL National Science Digital Library

    Richard Hynes (Massachusetts Institute of Technology; Howard Hughes Medical Institute, David H. Koch Institute for Integrative Cancer Research)

    2009-11-27

    The extracellular matrix (ECM) and ECM proteins are important in phenomena as diverse as developmental patterning, stem cell niches, cancer, and genetic diseases. The ECM has many effects beyond providing structural support. ECM proteins typically include multiple, independently folded domains whose sequences and arrangement are highly conserved. Some of these domains bind adhesion receptors such as integrins that mediate cell-matrix adhesion and also transduce signals into cells. However, ECM proteins also bind soluble growth factors and regulate their distribution, activation, and presentation to cells. As organized, solid-phase ligands, ECM proteins can integrate complex, multivalent signals to cells in a spatially patterned and regulated fashion. These properties need to be incorporated into considerations of the functions of the ECM.

  2. A Geometric Approach to Matrix Ordering

    E-print Network

    Auer, B O Fagginger

    2011-01-01

    We present a recursive way to partition hypergraphs which creates and exploits hypergraph geometry and is suitable for many-core parallel architectures. Such partitionings are then used to bring sparse matrices in a recursive Bordered Block Diagonal form (for processor-oblivious parallel LU decomposition) or recursive Separated Block Diagonal form (for cache-oblivious sparse matrix-vector multiplication). We show that the quality of the obtained partitionings and orderings is competitive by comparing obtained fill-in for LU decomposition with SuperLU (with better results for 8 of the 28 test matrices) and comparing cut sizes for sparse matrix-vector multiplication with Mondriaan (with better results for 4 of the 12 test matrices). The main advantage of the new method is its speed: it is on average 21.6 times faster than Mondriaan.

  3. Extracellular matrix as target for antitumor therapy

    PubMed Central

    Harisi, Revekka; Jeney, Andras

    2015-01-01

    The aim of the present review is to survey the accumulated knowledge on the extracellular matrix (ECM) of tumors referring to its putative utility as therapeutic target. Following the traditional observation on the extensive morphological alteration in the tumor-affected tissue, the well-documented aberrant cellular regulation indicated that ECM components have an active role in tumor progression. However, due to the diverse functions and variable expression of proteoglycans, matrix proteins, and integrins, it is rather difficult to identify a comprehensive therapeutic target among ECM components. At present, the elevated level of heparanase and the prominent expression of ?v?5 integrin are considered as promising therapeutic targets. The inhibition of glycosaminoglycan offers another promising approach in the treatment of those tumors which are stimulated by proteoglycans. It can be ascertained that a selective ECM inhibitor would be a great asset to control metastasis driven by ECM-mediated signaling. PMID:26089687

  4. Luneburg lens and optical matrix algebra research

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  5. Metal matrix composite structural panel construction

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  6. Transferring elements of a density matrix

    SciTech Connect

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

    2010-01-15

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

  7. Plastic matrix composites with continuous fiber reinforcement

    SciTech Connect

    NONE

    1991-09-19

    Most plastic resins are not suitable for structural applications. Although many resins are extremely tough, most lack strength, stiffness, and deform under load with time. By mixing strong, stiff, fibrous materials into the plastic matrix, a variety of structural composite materials can be formed. The properties of these composites can be tailored by fiber selection, orientation, and other factors to suit specific applications. The advantages and disadvantages of fiberglass, carbon-graphite, aramid (Kevlar 49), and boron fibers are summarized.

  8. Ceramic Matrix Composites for Rotorcraft Engines

    NASA Technical Reports Server (NTRS)

    Halbig, Michael C.

    2011-01-01

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

  9. Effective dynamics of the matrix big bang

    Microsoft Academic Search

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

    2006-01-01

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

  10. Matrix operators for complex interferometer analysis

    E-print Network

    Dahlgren, Robert P

    2010-01-01

    A modeling methodology and matrix formalism is presented that permits analysis of arbitrarily complex interferometric waveguide systems, including polarization and backreflection effects. Considerable improvement results from separation of the dependencies on connection topology from the dependencies on the devices and their specifications. A non-commutative operator and embedding matrices are introduced allowing a compact depiction of the salient optical equations, and straightforward calculation of the amplitude and intensity transfer functions.

  11. Matrix operators for complex interferometer analysis

    E-print Network

    Robert P. Dahlgren

    2011-02-05

    A modeling methodology and matrix formalism is presented that permits analysis of arbitrarily complex interferometric waveguide systems, including polarization and backreflection effects. Considerable improvement results from separation of the dependencies on connection topology from the dependencies on the devices and their specifications. A non-commutative operator and embedding matrices are introduced allowing a compact depiction of the salient optical equations, and straightforward calculation of the amplitude and intensity transfer functions.

  12. Airspace Operations Demo Functional Requirements Matrix

    NASA Technical Reports Server (NTRS)

    2005-01-01

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

  13. Matrix Product States and Quantum Phase Transitions

    E-print Network

    K. Heshami; S. Raeisi

    2009-09-16

    We have developed a new approach based on matrix product representations of ground states to study Quantum Phase Transitions (QPT). As confirmation of the power of our approach we have analytically analyzed the XXZ spin-one chain with uniaxial single-ion-type anisotropy and our results compare favourably with previous numerical studies. In addition, our description lets to know which part of parameters space of the Hamiltonian is most likely to be exactly solvable.

  14. Nonequilibrium chemistry boundary layer integral matrix procedure

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    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 chemistry while retaining all of the general boundary condition features built into the original code. For particular application to the pitch-plane of shuttle type vehicles, an approximate procedure was developed to estimate the nonequilibrium and nonisentropic state at the edge of the boundary layer.

  15. Thermoviscoplastic analysis of metal matrix composites

    Microsoft Academic Search

    Yeh Nanming

    1991-01-01

    Micromechanics-based thermoviscoplasticity theories based on over-stress are developed for metal matrix composites. Three micromechanics models, the vanishing fiber diameter model, the Mori-Tanaka method, and the bimodal model, are used in conjunction with the orthotropic thermoviscoplasticity theory based on overstress to study the thermomechanical behavior. Numerical experiments using the vanishing fiber diameter model and the orthotropic thermoviscoplasticity theory based on overstress

  16. Processable polyimide adhesive and matrix composite resin

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (inventor); St.clair, Terry L. (inventor); Progar, Donald J. (inventor)

    1990-01-01

    A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures.

  17. MATRIX-ASSISTED LASER DESORPTION MASS SPECTROMETRY

    Microsoft Academic Search

    Michael J. Stump; Richard C. Fleming; Wei-Hong Gong; Arwah J. Jaber; Jeffrey J. Jones; Charles W. Surber; Charles L. Wilkins

    2002-01-01

    Matrix-assisted laser desorption\\/ionization (MALDI) mass spectrometry is a technique that has attracted widespread interest since its introduction in 1988. It is primarily implemented using time-of-flight or trapped ion mass analyzers and greatly facilitates determination of molecular weights for biomolecules, polymers, and natural products. Numerous publications on these and related applications have appeared during the past ten years. The present brief

  18. Nanophosphor composite scintillators comprising a polymer matrix

    DOEpatents

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

    2010-11-16

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

  19. Ceramic Matrix Composite Vane Subelement Burst Testing

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  20. Joint Eigenvalue Decomposition Using Polar Matrix Factorization

    Microsoft Academic Search

    Xavier Luciani; Laurent Albera

    2010-01-01

    \\u000a In this paper we propose a new algorithm for the joint eigenvalue decomposition of a set of real non-defective matrices. Our\\u000a approach resorts to a Jacobi-like procedure based on polar matrix decomposition. We introduce a new criterion in this context\\u000a for the optimization of the hyperbolic matrices, giving birth to an original algorithm called JDTM. This algorithm is described\\u000a in

  1. Innovative processing techniques for intermetallic matrix composites

    NASA Astrophysics Data System (ADS)

    Stoloff, N. S.; Alman, D. E.

    A wide range of innovative techniques for processing intermetallic matrix composites is surveyed. The majority of processes involve the use of powders, although increasing attention is being directed towards vapor phase techniques. Most intermetallic composites produced to date are reinforced by particulates or random fibers. Several techniques have been successfully employed to produce continuous fiber reinforcements. Injection molding is feasible for producing aligned short fiber reinforced composites. The major success of the various new processing techniques is improved strength (monotonic and creep).

  2. Matrix Metalloproteinases, Synaptic Injury, and Multiple Sclerosis

    PubMed Central

    Szklarczyk, Arek; Conant, Katherine

    2010-01-01

    Multiple sclerosis (MS) is a disease of the central nervous system in which immune mediated damage to myelin is characteristic. For an overview of this condition and its pathophysiology, please refer to one of many excellent published reviews (Sorensen and Ransohoff, 1998; Weiner, 2009). To follow, is a discussion focused on the possibility that synaptic injury occurs in at least a subset of patients, and that matrix metalloproteinases (MMPs) play a role in such. PMID:21423441

  3. Pseudo-Hermitian random matrix theory

    E-print Network

    Shashi. C. L. Srivastava; S. R. Jain

    2013-02-12

    Complex extension of quantum mechanics and the discovery of pseudo-unitarily invariant random matrix theory has set the stage for a number of applications of these concepts in physics. We briefly review the basic ideas and present applications to problems in statistical mechanics where new results have become possible. We have found it important to mention the precise directions where advances could be made if further results become available.

  4. A Geometric Approach to Matrix Ordering

    Microsoft Academic Search

    B. O. Fagginger Auer; R. H. Bisseling

    2011-01-01

    We present a recursive way to partition hypergraphs which creates and exploits hypergraph geometry and is suitable for many-core parallel architectures. Such partitionings are then used to bring sparse matrices in a recursive Bordered Block Diagonal form (for processor-oblivious parallel LU decomposition) or recursive Separated Block Diagonal form (for cache-oblivious sparse matrix-vector multiplication). We show that the quality of the

  5. Size effects in metal matrix composites

    Microsoft Academic Search

    S. Groh; B. Devincre; L. P. Kubin; A. Roos; F. Feyel; J.-L. Chaboche

    2005-01-01

    The mechanical properties of Al\\/Al2O3 metal matrix composites are investigated using a 3D discrete-continuum simulation of dislocations and plasticity. The variations of the yield stress as a function of fibre volume fraction can be predicted from Orowan’s law. The dependence of internal stresses on fibre volume fraction leads to a size effect resulting from a virtual decrease of the channel

  6. Proton decay matrix elements from lattice QCD

    SciTech Connect

    Aoki, Yasumichi; Shintani, Eigo [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University, Nagoya 464-8602 (Japan); RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States); Collaboration: RBC Collaboration; UKQCD Collaboration

    2012-07-27

    We report on the calculation of the matrix elements of nucleon to pseudoscalar decay through a three quark operator, a part of the low-energy, four-fermion, baryon-number-violating operator originating from grand unified theories. The direct calculation of the form factors using domain-wall fermions on the lattice, incorporating the u, d and s sea-quarks effects yields the results with all the relevant systematic uncertainties controlled for the first time.

  7. Chiral random matrix theory for staggered fermions

    E-print Network

    James C. Osborn

    2012-04-24

    We present a completed random matrix theory for staggered fermions which incorporates all taste symmetry breaking terms at their leading order from the staggered chiral Lagrangian. This is an extension of previous work which only included some of the taste breaking terms. We will also discuss the effects of taste symmetry breaking on the eigenvalues in the weak and strong taste breaking limits, and compare with some results from lattice simulations.

  8. A tough high performance composite matrix

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    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.

  9. Sparse Matrix-Vector multiplication on FPGAs

    Microsoft Academic Search

    Ling Zhuo; Viktor K. Prasanna

    2005-01-01

    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

  10. Graphite matrix materials for nuclear waste isolation

    SciTech Connect

    Morgan, W.C.

    1981-06-01

    At low temperatures, graphites are chemically inert to all but the strongest oxidizing agents. The raw materials from which artificial graphites are produced are plentiful and inexpensive. Morover, the physical properties of artificial graphites can be varied over a very wide range by the choice of raw materials and manufacturing processes. Manufacturing processes are reviewed herein, with primary emphasis on those processes which might be used to produce a graphite matrix for the waste forms. The approach, recommended herein, involves the low-temperature compaction of a finely ground powder produced from graphitized petroleum coke. The resultant compacts should have fairly good strength, low permeability to both liquids and gases, and anisotropic physical properties. In particular, the anisotropy of the thermal expansion coefficients and the thermal conductivity should be advantageous for this application. With two possible exceptions, the graphite matrix appears to be superior to the metal alloy matrices which have been recommended in prior studies. The two possible exceptions are the requirements on strength and permeability; both requirements will be strongly influenced by the containment design, including the choice of materials and the waste form, of the multibarrier package. Various methods for increasing the strength, and for decreasing the permeability of the matrix, are reviewed and discussed in the sections in Incorporation of Other Materials and Elimination of Porosity. However, it would be premature to recommend a particular process until the overall multi-barrier design is better defined. It is recommended that increased emphasis be placed on further development of the low-temperature compacted graphite matrix concept.

  11. Simulation of bilinear flow in single matrix block drainage 

    E-print Network

    Branajaya, Romi Triaji

    2005-02-17

    This thesis presents modeling of bilinear flow in tight gas wells and its behavior on single matrix block drainage. The objectives of this research are to: simulate a tight gas well using matrix block drainage under constant production pwf...

  12. Matrix probing, skeleton decompositions, and sparse Fourier transform

    E-print Network

    Chiu, Jiawei

    2013-01-01

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

  13. Refined error estimates for matrix-valued radial basis functions 

    E-print Network

    Fuselier, Edward J., Jr.

    2007-09-17

    characterization of the native space, derive improved stability estimates for the interpolation matrix, and give divergence-free interpolation and approximation results for band-limited functions. Furthermore, we introduce a new class of matrix-valued RBFs that can...

  14. Contradiction of the DENSITY MATRIX notion in quantum mechanics

    E-print Network

    V. K. Ignatovich

    2012-04-20

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

  15. Analyticity and the Holographic S-Matrix

    SciTech Connect

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

    2012-04-03

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

  16. Matrix elasticity directs stem cell lineage specification

    NASA Astrophysics Data System (ADS)

    Discher, Dennis

    2010-03-01

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

  17. Multispectral palmprint recognition using a quaternion matrix.

    PubMed

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

    2012-01-01

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

  18. Nanomechanics of the Cartilage Extracellular Matrix

    PubMed Central

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

    2012-01-01

    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. PMID:22792042

  19. Research on graphite reinforced glass matrix composites

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  20. Gas chromatography/matrix-isolation apparatus

    DOEpatents

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

    1986-01-01

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

  1. Serum activity of matrix metalloproteinases-2 and-9

    Microsoft Academic Search

    G. M. Soboleva; A. V. Shurshalina; G. T. Sukhikh

    2006-01-01

    Matrix metalloproteinases belong to the key effectors of tissue remodeling in health and disease. Matrix metalloproteinases-2\\u000a and-9, the most prevalent representatives of this family, are expressed in the endometrium. Chronic endometritis concomitant\\u000a with sterility and spontaneous abortions is associated with decreased content of matrix metalloproteinases in the endometrium.\\u000a Chronic endometritis combined with sterility correlates with decreased serum activities of matrix

  2. String coupling and interactions in type IIB matrix model

    SciTech Connect

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

    2009-05-15

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

  3. Stability Analysis of Gyroscopic Systems via Quadratic Matrix Equations

    Microsoft Academic Search

    Nils Wagner; Lothar Gaul

    2006-01-01

    The linear equations of motion describing an n-degree-of-freedom damped, circulatory, gyroscopic system can be written in second order form Mq + (G + D) ? q + (K + N) q = 0, where M is the real, symmetric, positive definite mass matrix, G is the real, skew symmetric gyroscopic matrix, D is the real, symmetric, positive semidefinite damping matrix,

  4. INTEGRATED BIOMECHANICAL MODEL OF CELLS EMBEDDED IN EXTRACELLULAR MATRIX

    E-print Network

    Choe, Yoonsuck

    morphogenesis at the cellular level are the cytoskeleton, extracellular matrix (ECM), and cell adhesion. CellsINTEGRATED BIOMECHANICAL MODEL OF CELLS EMBEDDED IN EXTRACELLULAR MATRIX A Thesis by HARI SHANKAR BIOMECHANICAL MODEL OF CELLS EMBEDDED IN EXTRACELLULAR MATRIX A Thesis by HARI SHANKAR MUDDANA Submitted

  5. Extracellular matrix-mediated chemotaxis can impede cell migration

    E-print Network

    Sherratt, Jonathan A.

    (directed and random) during the process of migration. Proteolysis of the extracellular matrix (ECM) resultsExtracellular matrix-mediated chemotaxis can impede cell migration Abbey J. Perumpanani1,2 , David. A critical feature of cell migration is the ability of the migratory cells to digest extracellular matrix

  6. Original Papers Biomineralization of a Self-Assembled Extracellular Matrix

    E-print Network

    Meng, Yizhi

    in the extracellular matrix (ECM) of bone cells is crucial to the un- derstanding of bone formation and the development that bone cells, extracellular matrix (ECM), and scaffold material be addressed holistically as a threeOriginal Papers Biomineralization of a Self-Assembled Extracellular Matrix for Bone Tissue

  7. Research Article Live-cell imaging demonstrates extracellular matrix degradation

    E-print Network

    Bogyo, Matthew

    Localization of proteases to the surface of endothelial cells and remodeling of the extracellular matrix (ECM- existing vasculature, is a process in which stimulated endothelial cells remodel extracellular matrix (ECMResearch Article Live-cell imaging demonstrates extracellular matrix degradation in association

  8. Conversion of a Rhotrix to a "Coupled Matrix"

    ERIC Educational Resources Information Center

    Sani, B.

    2008-01-01

    In this note, a method of converting a rhotrix to a special form of matrix termed a "coupled matrix" is proposed. The special matrix can be used to solve various problems involving n x n and (n - 1) x (n - 1) matrices simultaneously.

  9. Silk matrix for tissue engineered anterior cruciate ligaments

    Microsoft Academic Search

    Gregory H Altman; Rebecca L Horan; Helen H Lu; Jodie Moreau; Ivan Martin; John C Richmond; David L Kaplan

    2002-01-01

    A silk-fiber matrix was studied as a suitable material for tissue engineering anterior cruciate ligaments (ACL). The matrix was successfully designed to match the complex and demanding mechanical requirements of a native human ACL, including adequate fatigue performance. This protein matrix supported the attachment, expansion and differentiation of adult human progenitor bone marrow stromal cells based on scanning electron microscopy,

  10. Proposed framework for thermomechanical life modeling of metal matrix composites

    Microsoft Academic Search

    G. R. Halford; B. A. Lerch; J. F. Saltsman

    1993-01-01

    The framework of a mechanics of materials model is proposed for thermomechanical fatigue (TMF) life prediction of unidirectional, continuous-fiber metal matrix composites (MMC's). Axially loaded MMC test samples are analyzed as structural components whose fatigue lives are governed by local stress-strain conditions resulting from combined interactions of the matrix, interfacial layer, and fiber constituents. The metallic matrix is identified as

  11. Microglial Activation and Matrix Protease Generation During Focal Cerebral Ischemia

    Microsoft Academic Search

    Gregory J. del Zoppo; Richard Milner; Takuma Mabuchi; Stephanie Hung; Xiaoyun Wang; Greta I. Berg; James A. Koziol

    2010-01-01

    Local environmental conditions contribute to the activation state of cells. Extracellular matrix glycoproteins participate in cell-cell boundaries within the microvascular and extravascular tissues of the central nervous system and provide a scaffold for the local environment. These conditions are altered during focal cerebral ischemia (and other central nervous system disorders) when extracellular matrix boundaries are degraded or when matrix proteins

  12. Google matrix analysis of directed networks Leonardo Ermann

    E-print Network

    Shepelyansky, Dima

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

  13. Organizing matrices and matrix operations for paged memory systems

    Microsoft Academic Search

    A. C. McKellar; Edward G. Coffman Jr.

    1969-01-01

    Matrix representations and operations are examined for the purpose of minimizing the page faulting occurring in a paged memory system. It is shown that carefully designed matrix algorithms can lead to enormous savings in the number of page faults occurring when only a small part of the total matrix can be in main memory at one time. Examination of addition,

  14. Control mechanisms across a buyer–supplier relationship quality matrix

    Microsoft Academic Search

    Yi Liu; Yuan Li; Leinan Zhang

    2010-01-01

    This study develops a buyer–supplier RQ matrix and explores changes in the use of selected control mechanisms, including coercive power, non-coercive power, contracts, and relational norms, across this matrix. The results indicate, under four distinct contexts of RQ, that coercive power execution is relatively low and has no significant differences in different quadrants of the matrix; that contract execution is

  15. The Scaling and Squaring Method for the Matrix Exponential Revisited

    Microsoft Academic Search

    Nicholas J. Higham

    2005-01-01

    The scaling and squaring method is the most widely used method for computing the matrix exponential, not least because it is the method implemented in MATLAB's expm function. The method scales the matrix by a power of 2 to reduce the norm to order 1, computes a Pade approximant to the matrix exponential, and then repeatedly squares to undo the

  16. On the conflict matrix of clause-sets Oliver Kullmann

    E-print Network

    Grant, P. W.

    On the conflict matrix of clause-sets Oliver Kullmann Computer Science Department University.ac.uk/csoliver/ March 13, 2003 Abstract We study the asymmetric respectively symmetric conflict matrix of a multi of a (symmetric) conflict matrix A, which is the minimal number of variables in a multi-clause-set F

  17. Balance between matrix synthesis and degradation: a determinant of glomerulosclerosis

    Microsoft Academic Search

    H. William Schnaper

    1995-01-01

    In glomerular health and disease, the balance between extracellular matrix (ECM) protein synthesis and degradation determines the amount of matrix that accumulates locally. While cell and whole animal regulation of ECM synthesis has been the subject of ongoing study, attention has become focused on proteases that degrade matrix components only recently. Two major ECM protease systems have been defined. The

  18. Enterprise Text Processing: A Sparse Matrix Approach Nazli Goharian

    E-print Network

    to incorporate Proximity Search capability into the system also indicate 35% less storage for sparse matrix overEnterprise Text Processing: A Sparse Matrix Approach Nazli Goharian Illinois Institute of supporting efficient and accurate text processing. As many parallel sparse matrix-vector multiplication

  19. Dot Matrix Impact Printers: An Overview and Guide.

    ERIC Educational Resources Information Center

    Warden, William H.; Warden, Bette M.

    1983-01-01

    Comparison of dot matrix impact printers details price, matrix density, speed, print sizes, feed width, interface connectors, and true descender characteristics. Dot matrix versus preformed characters, maintenance and repair, installing printers at microcomputer workstations, value comparisons, and descriptions of specific printers are…

  20. A matrix product coprocessor for FPGA embedded soft processors

    Microsoft Academic Search

    Pasquale Corsonello; Stefania Perri; Paolo Zicari

    2005-01-01

    This paper present a matrix coprocessor specialized for computing matrix product. The proposed circuit allows a significant reduction in the computational time required by a general-purpose processor for the sequential execution of the matrix product. The coprocessor has been integrated with a RISC processor and a field programmable system on chip has been realized. The new circuit uses p processor