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1

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

NASA Astrophysics Data System (ADS)

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

Siegel, Carl Ludwig; Carl-Ludwig Siegel, Edward

2011-03-01

2

List Formats Improve Medication Instructions for Older Adults.  

ERIC Educational Resources Information Center

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…

Morrow, Daniel; And Others

1995-01-01

3

Modelling Tabular Data with an Ordered Outcome  

Microsoft Academic Search

A large amount of data that is considered within sociological studies consists of categorical variables that lend themselves to tabular analysis. In the sociological analysis of data regarding social class and educational attainment, for example, the variables of interest can often plausibly be considered as having a substantively interesting order. Standard log-linear models do not take ordinality into account, thereby

Vernon Gayle

1996-01-01

4

A Tabular Survey of Automated Table Processing  

Microsoft Academic Search

Tables are the only acceptable means of communicating certain types of structured data. A precise definition of “tabularity”\\u000a remains elusive because some bureaucratic forms, multicolumn text layouts, and schematic drawings share many characteristics\\u000a of tables. There are significant differences between typeset tables, electronic files designed for display of tables, and\\u000a tables in symbolic form intended for information retrieval. Although most

Daniel P. Lopresti; George Nagy

1999-01-01

5

Testing variants of minimum distance controlled tabular adjustment  

Microsoft Academic Search

Controlled tabular adjustment (CTA), and its minimum distance variants, is a recent methodology for the protection of tabular data. Given a table to be protected, the purpose of the method is to fi nd the closest one that guarantees the confi dentiality of the sensitive cells. This is achieved by adding slight adjustments to the remaining cells, preferably excluding total

Jordi Castro; Sarah Giessing

6

A new model for tabular-type uranium deposits  

USGS Publications Warehouse

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

Sanford, R. F.

1992-01-01

7

Geosites inventory of the northwestern Tabular Middle Atlas of Morocco  

Microsoft Academic Search

Across the northwestern Tabular Middle Atlas of Morocco there are many examples of landscapes, rocks and fossils that provide key evidence of a particular moment or period in Earth history. Such Earth heritage sites are important for educating the general public in environmental matters. They also serve as tools for demonstrating sustainable development and for illustrating methods of site conservation

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

2008-01-01

8

The Functional Significance of Nectridean Tabular Horns (Amphibia: Lepospondyli)  

Microsoft Academic Search

The order Nectridea of the subclass Lepospondyli is of Palaeozoic age. Within this order, later members of the Keraterpetontidae developed hyper-extended tabular horns, so that in plan view the skull is boomerangshaped. Many unsuccessful attempts have been made to explain this shape in functional terms. The two genera that show the greatest development of these horns. Diplocaulus Cope and Diploceraspis

A. R. I. Cruickshank; B. W. Skews

1980-01-01

9

Geosites inventory of the northwestern Tabular Middle Atlas of Morocco  

Microsoft Academic Search

Across the northwestern Tabular Middle Atlas of Morocco there are many examples of landscapes, rocks and fossils that provide\\u000a key evidence of a particular moment or period in Earth history. Such Earth heritage sites are important for educating the\\u000a general public in environmental matters. They also serve as tools for demonstrating sustainable development and for illustrating\\u000a methods of site conservation

Mohamed El Wartiti; Amina Malaki; Mohamed Zahraoui; Abdelilah El Ghannouchi; Felice Di Gregorio

2008-01-01

10

Supporting Awareness through Collaborative Brushing and Linking of Tabular Data.  

PubMed

Maintaining an awareness of collaborators' actions is critical during collaborative work, including during collaborative visualization activities. Particularly when collaborators are located at a distance, it is important to know what everyone is working on in order to avoid duplication of effort, share relevant results in a timely manner and build upon each other's results. Can a person's brushing actions provide an indication of their queries and interests in a data set? Can these actions be revealed to a collaborator without substantially disrupting their own independent work? We designed a study to answer these questions in the context of distributed collaborative visualization of tabular data. Participants in our study worked independently to answer questions about a tabular data set, while simultaneously viewing brushing actions of a fictitious collaborator, shown directly within a shared workspace. We compared three methods of presenting the collaborator's actions: brushing & linking (i.e. highlighting exactly what the collaborator would see), selection (i.e. showing only a selected item), and persistent selection (i.e. showing only selected items but having them persist for some time). Our results demonstrated that persistent selection enabled some awareness of the collaborator's activities while causing minimal interference with independent work. Other techniques were less effective at providing awareness, and brushing & linking caused substantial interference. These findings suggest promise for the idea of exploiting natural brushing actions to provide awareness in collaborative work. PMID:24051785

Hajizadeh, Amir Hossein; Tory, Melanie; Leung, Rock

2013-12-01

11

Geosites inventory of the northwestern Tabular Middle Atlas of Morocco  

NASA Astrophysics Data System (ADS)

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

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

2008-07-01

12

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

Microsoft Academic Search

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

James E. Quick

1982-01-01

13

Application of Tabular Methods to the Speciflcation and Veriflcation of a Nuclear Reactor Shutdown System  

Microsoft Academic Search

This paper describes the use of tabular methods at Ontario Power Generation Inc. (OPGI) 1 on the Darlington Nuclear Generating Station Shutdown System (SDS) Trip Computer Software Redesign Project. We flrst motivate the selection of tabular methods and provide an overview of the Systematic Design Veriflcation (SDV) procedure. After reviewing some preliminary concepts, the paper describes how the Software Engineering

M. Lawford

14

Models and Algorithms for Optimizing Cell Suppression in Tabular Data with Linear Constraints  

Microsoft Academic Search

Cell suppression is a widely used technique for protecting sensitive information in statistical data presented in tabular form. Previous works on the subject mainly concentrate on two- and three-dimensional tables whose entries are subject to marginal totals. In this article we address the problem of protecting sensitive data in a statistical table whose entries are linked by a generic system

Matteo Fischetti; José Juan Salazar González

2000-01-01

15

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

Microsoft Academic Search

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

David B. MacKay; Angelina Villarreal

1987-01-01

16

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

PubMed Central

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

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

2011-01-01

17

Transposition of Large Tabular Data Structures with Applications to Physical Database Organization  

Microsoft Academic Search

Tabular data structures of a relational database, placed in a paged virtual space or in some two-level storage, are discussed. To rearrange, or transpose, those data stored attributewise to those stored tuplewise, and vice versa, an algorithm is devised that causes a minimal amount of page fetches. The algorithm is near best possible, since it is a generalization of Floyd's

Takao Tsuda; Takashi Sato

1983-01-01

18

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

NASA Astrophysics Data System (ADS)

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

Schmalz, M.; Key, G.

19

Geosites And Touristic Development Of The Northwestern Tabular Middle Atlas Of Morocco  

Microsoft Academic Search

Across the northwestern Tabular Middle Atlas of Morocco there are many examples of landscapes, rocks and fossils providing\\u000a key evidence of a particular moment or period in Earth history. Such Earth heritage sites are important for educating the\\u000a general public in environmental matters. They also serve as tools for demonstrating sustainable development and for illustrating\\u000a methods of site conservation, as

Mohamed El Wartiti; Amina Malaki; Mohamed Zahraoui; Felice Gregorio; Jo Waele

20

A portable ultrasonic phased array device for tabular joint weld inspection of offshore platform structures  

NASA Astrophysics Data System (ADS)

To meet the inspection need for complex tabular joints weld of offshore platform structures, a portable ultrasonic phased array inspection device is developed. The integrated device is small and portable. As designed, the device can implement different algorithm of the ultrasonic phased array inspection technology. With proposed inspection plan, the experiment of Y tubular joint model was performed in lab. Experiment results indicate that the possible ultrasonic phased array inspection device can detect and visualize the flaws on Y tubular joint weld, which are nearly consistent with the actual condition.

Shan, Baohua; Li, Jingan; Duan, Zhongdong; Ou, Jinping; Shen, Wei

2012-05-01

21

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

PubMed Central

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.

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

2004-01-01

22

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

PubMed

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

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

2004-11-03

23

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

USGS Publications Warehouse

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

Sanford, R. F.

1994-01-01

24

The Communicability of Graphical Alternatives to Tabular Displays of Statistical Simulation Studies  

PubMed Central

Simulation studies are often used to assess the frequency properties and optimality of statistical methods. They are typically reported in tables, which may contain hundreds of figures to be contrasted over multiple dimensions. To assess the degree to which these tables are fit for purpose, we performed a randomised cross-over experiment in which statisticians were asked to extract information from (i) such a table sourced from the literature and (ii) a graphical adaptation designed by the authors, and were timed and assessed for accuracy. We developed hierarchical models accounting for differences between individuals of different experience levels (under- and post-graduate), within experience levels, and between different table-graph pairs. In our experiment, information could be extracted quicker and, for less experienced participants, more accurately from graphical presentations than tabular displays. We also performed a literature review to assess the prevalence of hard-to-interpret design features in tables of simulation studies in three popular statistics journals, finding that many are presented innumerately. We recommend simulation studies be presented in graphical form.

Cook, Alex R.; Teo, Shanice W. L.

2011-01-01

25

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

NASA Astrophysics Data System (ADS)

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 CDC were obtained through a multistep coating process. The phases were studied by X-ray diffraction. The morphology and coating quality were studied by scanning electron microscopy and element mapping of energy dispersive X-ray analysis. The oxidation catalytic activity, UV-shielding ability and using comfort were characterized by Rancimat test, UV-vis spectra and dynamic friction test, respectively. CDC/TT nanocomposites with low oxidation catalytic activity, high UV-shielding ability and good using comfort were finally obtained.

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

2010-07-01

26

The development and preservation of tabular massive ground ice in permafrost regions  

NASA Astrophysics Data System (ADS)

An investigation of tabular massive ground ice was conducted to ascertain if ground ice has distinctive characteristics that could be measured and used to determine the origin of the ice. Initial studies were conducted on Bylot Island in the eastern Canadian Arctic, where some glaciers are rapidly retreating, resulting in buried massive ground ice. The environments with the greatest potential for the burial and preservation of massive ice were first examined and the processes of burial identified. It was determined that glacier end and lateral moraines have the greatest potential for preserving massive ice. Ground penetrating radar (GPR) methodology was developed for imaging the subsurface geometry and structure of glaciers, icing, and ground ice bodies. GPR was shown to be effective for mapping icing and glacier geometry, hydrology and subbottom structure, and possibly thermal conditions. GPR also proved effective at delineating the size and thickness of massive ground ice bodies. This revealed that the ice core in lateral and end moraines around Stagnation Glacier are continuous and extensive. Physical property analyses indicated that some ice types could not be differentiated on their physical properties alone. A methodology was thus developed for extracting and analyzing the gaseous component of ice which would provide a differentiating technique. This method enabled the measurement of the chemical and isotopic composition of the ice and gases, and direct age determination of the ice by radiocarbon dating of the COsb2 in the bubbles. In testing the technique in the proglacial environment on Bylot Island, the environmental history of the site was linked to the more extensive ice core records from Greenland and Devon Island. Along with the other ice property analysis techniques, the gas analysis techniques were applied to three sites across the western Canadian Arctic (Peninsula Point, North Point, and Herschel Island). It was discovered that ground ice bodies in the Tuktoyaktuk Peninsula and on Herschel Island were considerably younger than had been reported previously. In a detailed study of the massive ground ice at Peninsula Point it was determined that the ice mass developed from the segregation of ice formed from a ground water source. The ground water probably originated as glacial meltwater, with several different sources, each with different isotopic signatures.

Moorman, Brian James

27

Barometric effects on tabular iceberg drift in the Ross Sea, Antarctica  

NASA Astrophysics Data System (ADS)

The Inverse Barometer Effect (IBE) was observed in the nineteenth century by Sir James Clark Ross (Ross, 1854a), as deviations in sea-surface elevation in response to deviations in atmospheric pressure. This effect embodies the inverse relationship between sea-surface height (relative to long-term mean sea level) and atmospheric surface pressure. This thesis addresses the hypothesis that icebergs in the Ross Sea region of Antarctica are influenced by the same forces that create the IBE. This hypothesis is motivated by studies of icebergs in the Ross Sea, where drift data suggest that icebergs are drawn into temporary holding zones, or "Iceberg Parking Lots" situated where the surface pressure tends to display persistent, annual average low pressure. A physical explanation for the IBE's influence on icebergs is that they are often able to travel up the sea-surface slope induced by the IBE below atmospheric lows against the gravitational pull because of the pressure gradient force of the atmosphere acting on the iceberg's freeboard (the part of the iceberg that is above the waterline). Here, I evaluate the validity of the hypothesized IBE-iceberg relationship using a combined approach of data analysis and modeling. I have examined atmospheric surface pressure and wind records taken directly from the surfaces of four Ross Sea icebergs---B15A, B15K, C16, and B15J, and I have also built, and experimented with, models that predict iceberg drift response to atmospheric surface pressure and surface winds, using observed pressures and winds from B15A and B15J as model forcing. I additionally performed various experiments on a large, idealized tabular iceberg's physical sensitivity to the IBE using a model that treats atmospheric pressure and winds in an idealized, theoretical manner. I discovered that the IBE is indeed a significant influence on iceberg drift in and around Lewis Bay, just to the north of Ross Island, which will further our understanding of these icebergs' trajectories. While I do not believe that the IBE-iceberg relationship is universally so pronounced as it is in Lewis Bay, and may not necessarily be responsible for all other places where icebergs tend to collect for long periods, it should be considered in any iceberg drift models that deal with regions having strong and persistent pressure gradients. In the Ross Sea, the pressure gradient toward Ross Island can be the overwhelming force on icebergs drifting just to the north of it, until another force such as the ocean current is able to exert itself more strongly.

Turnbull, Ian D.

28

Compilation and R-matrix analysis of Big Bang nuclear reaction rates  

Microsoft Academic Search

We use the R-matrix theory to fit low-energy data on nuclear reactions involved in Big Bang nucleosynthesis. Special attention is paid to the rate uncertainties which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats.

Pierre Descouvemont; Abderrahim Adahchour; Carmen Angulo; Alain Coc; Elisabeth Vangioni-Flam

2004-01-01

29

SAMDIST: A computer code for calculating statistical distributions for R-matrix resonance parameters  

SciTech Connect

The SAMDIST computer code has been developed to calculate distribution of resonance parameters of the Reich-Moore R-matrix type. The program assumes the parameters are in the format compatible with that of the multilevel R-matrix code SAMMY. SAMDIST calculates the energy-level spacing distribution, the resonance width distribution, and the long-range correlation of the energy levels. Results of these calculations are presented in both graphic and tabular forms.

Leal, L.C.; Larson, N.M.

1995-09-01

30

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

Microsoft Academic Search

Based on the results of ORIGEN2 and a newly developed code called ORMANG, graphical and summary tabular characteristics of spent fuel, high-level waste, and fuel assembly structural material (cladding) waste are presented for a generic pressurized-water reactor (PWR), a liquid-metal fast breeder reactor (LMFBR), and the Fast Flux Test Facility (FFTF). The characteristics include radioactivity, thermal power, and toxicity (water

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

1982-01-01

31

Matrix Simulation  

NSDL National Science Digital Library

This applet simulates the operation of a 2x2 matrix geometrically. The simulation shows a 2D image of the transformation of unit vectors due to the matrix. It displays the values of the matrix coefficients, the eigenvectors and the determinant. The matrix can be transposed, inverted or rotated. The page also includes an extensive explanation, and the source.

Falstad, Paul

2004-07-23

32

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

33

Dimensional scaling relationships of tabular igneous intrusions and their implications for a size, depth and compositionally dependent spectrum of emplacement processes in the crust  

NASA Astrophysics Data System (ADS)

A global compilation of the horizontal (L) and vertical dimensions (T) of broadly tabular, sub-horizontal intrusions of mafic to felsic composition emplaced into shallow to mid-crustal levels of continental crust reveals two well-defined and continuous curves in log L vs. log T space. The data set comprises a six and five orders of magnitude range in L (1 m to 1000 km) and T (~ 10 cm to 10 km), respectively. Data for tabular sheets and sills (mafic and felsic) define a straight line with a slope a ~ 0.7 at all horizontal length scales, indicating a tendency for the L/T ratio of these intrusions to increase with increasing L (horizontal lengthening dominates over vertical thickening). Laccoliths, plutons and layered mafic intrusions and batholiths define an open, continuous S-shaped curve that bifurcates from the tabular sheets and sills curve at L ~ 500 m towards higher T-values. For L ~ 500 m to 10 km the slope of this curve is a ~ 1.5, corresponding to laccoliths that are characterized by a decrease in L/T ratio with increasing L (vertical thickening dominates over horizontal lengthening). Between L ~ 10 and 100 km the slope is < 1 and decreases with increasing L, having a mean value a ~ 0.6. Plutons and layered mafic intrusions therefore show an increasing tendency for horizontal lengthening over vertical thickening as L increases. Batholiths and very large layered mafic intrusions with L > 100 km lie on a slope with a ~ 0. The corresponding constant T-value of ~ 15 km may represent a vertical growth limit for igneous intrusions in the crust. The continuous nature of the dimensional data over such a wide range of length scales reflects a spectrum of igneous emplacement processes repeated in space and time. Thresholds or transitions in this spectrum defined by bifurcations in the curves (e.g., between sill and laccolith emplacement) and changes in slope reflect changes in emplacement mechanism(s) that are related to intrinsic and extrinsic controls such as intrusion depth, magma viscosity, composition and temperature, and local tectonic setting. For example the bifurcation between shallow level sills and laccoliths likely reflects magma viscosity; low viscosity mafic magma can drive a fracture that lengthens faster than it thickens, while a higher viscosity intermediate to felsic magma has limited potential to spread laterally and vertical thickening will dominate due to continuous inflation or sequential stacking of intrusive sheets. The transition from laccolith growth (a > 1) to pluton growth (a < 1) is most likely depth controlled, reflecting the transition from shallow emplacement where vertical growth by roof lifting is favored, to deeper levels where vertical growth must be accommodated by the interaction between crustal scale mass transfer (floor depression) and regional and local tectonic- and intrusion-related deformation. Although available data is limited, vertical growth of plutons and layered mafic intrusions may be achieved by sequential stacking of sheets with dimensions that define distinct growth curves in log T vs. log L space. Likewise, the dimensions of batholiths represent limits on the vertical and horizontal aggradation of smaller plutons in the crust.

Cruden, A.; McCaffrey, K.

2006-12-01

34

Matrix Arithmetic  

NSDL National Science Digital Library

The purposes of this module are to experiment with matrix addition, subtraction, and (mostly) multiplication; to see that many familiar arithmetic properties of real numbers carry over to matrices, but some do not.

Blake, Lewis; Smith, David

1999-06-04

35

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

PubMed Central

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

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

2009-01-01

36

Matrix Metalloproteinases  

PubMed Central

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

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

2001-01-01

37

Matrix Theory.  

National Technical Information Service (NTIS)

Two areas of matrix theory are discussed: the theory of permanents, and the theory of nonnegative matrices. Paper (1) deals with permanental compounds and their use in recurrence formulas for permanents of (0,1)-circulants and in related asymptotic formul...

H. Minc

1987-01-01

38

Matrix geometries and matrix models  

NASA Astrophysics Data System (ADS)

We study a two parameter single trace 3-matrix model with SO(3) global symmetry. The model has two phases, a fuzzy sphere phase and a matrix phase. Configurations in the matrix phase are characterised by a parabolic eigenvalue distribution of radius R = 2 .0. We study the co-existence curve of the model and find evidence that it has two distinct portions one with a discontinuous internal energy yet critical fluctuations of the specific heat but only on the low temperature side of the transition and the other portion has a continuous internal energy with a discontinuous specific heat of finite jump. We study in detail the eigenvalue distributions of different observables.

Delgadillo-Blando, Rodrigo; O'Connor, Denjoe

2012-11-01

39

Supertropical matrix algebra  

Microsoft Academic Search

The objective of this paper is to develop a general algebraic theory of supertropical matrix algebra, extending [11]. Our main results are as follows: * The tropical determinant (i.e., permanent) is multiplicative when all the determinants involved are tangible. * There exists an adjoint matrix $\\\\adj{A}$ such that the matrix $A \\\\adj{A}$ behaves much like the identity matrix (times $|A|$).

Zur Izhakian; Louis Rowen

2008-01-01

40

Nanocrystal doped matrixes  

Microsoft Academic Search

Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present

J. Wallace Parce; Paul Bernatis; Robert Dubrow; William P. Freeman; Joel Gamoras; Shihai Kan; Andreas Meisel; Baixin Qian; Jeffery A. Whiteford; Jonathan Ziebarth

2010-01-01

41

Metal Matrix Composites  

Microsoft Academic Search

Metal matrix composites have found selected application in areas that can cost-effectively capitalize on improvements in specific stiffness, specific strength, fatigue resistance, wear resistance, and coefficient of thermal expansion. 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

Warren Hunt; Darrell R. Herling

2004-01-01

42

A matrix lower bound  

SciTech Connect

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

Grcar, Joseph F.

2002-02-04

43

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

USGS Publications Warehouse

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

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

2006-01-01

44

Carbonate fuel cell matrix  

DOEpatents

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

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

1996-01-01

45

Carbonate fuel cell matrix  

DOEpatents

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

Farooque, M.; Yuh, C.Y.

1996-12-03

46

Sparse matrix test problems  

Microsoft Academic Search

We describe the Harwell-Boeing sparse matrix collection, a set of standard test matrices for sparse matrix problems. Our test set comprises problems in linear systems, least squares, and eigenvalue calculations from a wide variety of scientific and engineering disciplines. The problems range from small matrices, used as counter-examples to hypotheses in sparse matrix research, to large test cases arising in

Iain S. Duff; Roger G. Grimes; John G. Lewis

1989-01-01

47

Matrix with Prescribed Eigenvectors  

ERIC Educational Resources Information Center

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

Ahmad, Faiz

2011-01-01

48

Matrix cracking in ceramic-matrix composites  

Microsoft Academic Search

Matrix cracking in ceramic-matrix composites with unbonded frictional interface has been studied using fracture mechanics theory. The critical stress for extension of a fiber-bridged crack has been analyzed using the stress-intensity approach. The analysis uses a new shear-lag formulation of the crack-closure traction applied by the bridging fibers based on the assumption of a constant sliding friction stress over the

Sawai Danchaivijit; Dinesh K. Shetty

1993-01-01

49

Nanocrystal doped matrixes  

DOEpatents

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

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

2010-01-12

50

Matrix for Planning.  

ERIC Educational Resources Information Center

|This Matrix for Planning presents an organized format for systematically recording information relevant to the formulation of long-range planning policies and decisions for the Massachusetts Community Colleges. The matrix organizes existing data into a four-fold conceptual structure: people, programs, facilities, and funding. The first category…

Dober and Associates, Inc., Belmont, MA.

51

Gate Matrix Layout  

Microsoft Academic Search

A graph-theoretic description of the problem of layout of CMOS circuits in the style of gate matrix in minimum area is presented. The problem is formulated as one of finding two assignment functions f and h such that the layout L(f, h) requires the minimum number of rows of the gate matrix. The function f maps the distinct gates of

Omar Wing; Shuo Huang; Rui Wang

1985-01-01

52

Developments in Alaska in 1979. [Tabular data  

Microsoft Academic Search

Twenty-three exploratory wells were drilled in Alaska in 1979. Six apparent oil discovery wells were drilled on the North Slope and 3 gas discoveries were made in the Cook Inlet basin. Four wells drilled in the Lower Cook Inlet outer continental shelf (OCS) area were dry. Eighty-four development and service wells were drilled and successfully completed. Geologic-geophysical field activity by

1980-01-01

53

GALENA: Tabular DCG Parsing for Natural Languages  

Microsoft Academic Search

We present a definite clause based parsing environment for natural languages, whoseoperational model is the dynamic interpretation of logical push-down automata. We attemptto briefly explain our design decisions in terms of a set of properties that practical naturallanguage processing systems should incorporate. The aim is to show both the advantagesand the drawbacks of our approach.1 IntroductionLogic programming have been extensively

Manuel Vilares Ferro; Miguel A. Alonso; Jorge Graña Gil; David Cabrero Souto

1998-01-01

54

Matrix metalloproteinases in repair.  

PubMed

During repair, many different matrix metalloproteinases are produced by multiple cell types residing in various compartments within the wound environment. This diversity of enzymes, coupled with discreet cellular expression, implies that different matrix metalloproteinases serve different functions, acting on a variety of substrates, during wound healing. With few exceptions, however, the actual function and spectrum of functions of matrix metalloproteinases in vivo is not known. Even with the advent of genetically defined animal models, few studies have rigorously addressed the substrates and role of matrix metalloproteinases in wound repair. Before we can understand the role of matrix metalloproteinases in ulceration and disease, we need to determine the function these enzymes serve in normal tissues and repair. PMID:10633001

Parks, W C

55

Perturbations in the Nevai matrix class of orthogonal matrix polynomials  

Microsoft Academic Search

In this paper we study a Jacobi block matrix and the behavior of the limit of its entries when a perturbation of its spectral matrix measure by the addition of a Dirac delta matrix measure is introduced.

Hossain O. Yakhlef; Francisco Marcellán; Miguel A. Piñar

2001-01-01

56

Hybrid matrix amplifier  

DOEpatents

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

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

1995-01-03

57

Hybrid matrix amplifier  

DOEpatents

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

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

1995-01-01

58

Kidney Histology Rules Matrix  

Cancer.gov

Kidney Histo Kidney Histology Coding Rules – Matrix C649 (Excludes lymphoma and leukemia M9590 – 9989 and Kaposi sarcoma M9140) Rule Pathology/Cytology Specimen Histology Behavior Notes and Examples Code SINGLE TUMOR H1 None or the pathology

59

Metal Matrix Composites  

SciTech Connect

Metal matrix composites have found selected application in areas that can cost-effectively capitalize on improvements in specific stiffness, specific strength, fatigue resistance, wear resistance, and coefficient of thermal expansion. 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, including aluminum, beryllium, magnesium, titanium, iron, nickel, cobalt, and silver. However, aluminum is by far the most preferred. For reinforcements, the materials are typically ceramics, which provide a very beneficial 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, metallic materials such as tungsten and steel fibers have been considered.

Hunt, Warren; Herling, Darrell R.

2004-02-01

60

Superfund Chemical Data Matrix.  

National Technical Information Service (NTIS)

The Superfund Chemical Data Matrix (SCDM) is a source for factor values and benchmark values applied when evaluating potential National Priority List (NPL) sites using the Hazard Ranking System (HRS). The HRS assigns factor values for toxicity, gas migrat...

1994-01-01

61

Silicon Carbide Matrix Composites.  

National Technical Information Service (NTIS)

The latest development for silicon carbide/silicon carbide and carbon/silicon carbide composites are presented. These composites are obtained by processes based on infiltration, and pyrolysis of organometallic materials. Ceramic matrix composites are prom...

P. Pernot P. Lespade M. Parlier

1992-01-01

62

Matrix Metalloproteinase Inhibitor Peptides.  

National Technical Information Service (NTIS)

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

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

1990-01-01

63

Melanoma Histology Rules Matrix  

Cancer.gov

Cutaneous Melanoma Histology Coding Rules – Matrix C440-C449 (Excludes melanoma of all other sites) Rule Melanoma Specimen Histology Behavior Notes and Examples Code SINGLE MELANOMA OR MULTIPLE MELANOMAS ABSTRACTED AS A SINGLE PRIMARY H1 No

64

Aluminum Metal Matrix Composites  

SciTech Connect

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.

Hunt, Warren; Herling, Darrell R.

2004-02-01

65

An MCS Matrix  

NSDL National Science Digital Library

The MCS Matrix provides learners the opportunity for extensive exploration of the relationship between a MCSs environment and its structure. The matrix is composed of 21 four-dimensional numerical simulations based on the interactions of 10 different hodographs with a common thermodynamic profile. By comparing animated displays of these simulations learners are able to discern the influences of vertical wind shear and the Coriolis Force on MCS structure and evolution.

Spangler, Tim

1999-01-01

66

Ceramic Matrix Composites  

SciTech Connect

Ceramic matrix composites (CMCs) are being developed to take advantage of the high-temperature properties of ceramics while overcoming the low fracture toughness of monolithic ceramics. Toughening mechanisms, such as matrix cracking, crack deflection, interface debonding, crack-wake bridging and fiber pullout, are being incorporated in CMCs to reduce the tendency for catastrophic failure found in monolithic ceramics. Ceramics reinforced with particulate, whiskers and continuous fibers exhibit varying aspects of these toughening mechanisms; however, reinforcement with continuous fibers offers the greatest improvements in toughness. Composites with carbide, oxide, glass and carbon matrices are being utilized in the development of CMCs. In the case of carbide, oxide and glass matrix CMCs, the matrix exhibits excellent high-temperature corrosion resistance so that a goal of the composite development is to not detract from this pre-existing property. This is not the case for carbon matrix composites which frequently need coatings to provide adequate corrosion protection. The purpose of this chapter is to review the database and understanding of corrosion behavior of CMCs with the intent that this information will be useful in the development of materials with improved performance and reliability.

Jones, Russell H.; Henager, Charles H.; Lewinsohn, Charles A.; Windisch, Charles F.

2001-11-12

67

Intermetallic matrix composites  

SciTech Connect

This book presents a symposium on the complex processing-microstructure-property relationships in intermetallic matrix composite materials. It may appear to the reader that some of the work reported in this volume does not bear on this question, but it should be remembered that intermetallic compounds have properties similar to both ceramics (at low temperatures) and metals (at high temperatures). Thus the techniques for toughening brittle matrix composites at ambient temperatures as well as those for strengthening ductile matrix composites at elevated temperatures need to be applied to the intermetallic situation. For this reason, the session on microstructure-based modeling of the behavior of intermetallic matrix composites drew heavily on ceramic and metal matrix experience. The session discussing processing was also a mix of ceramic and metallurgical approaches, while stressing novel methods particular to composite microstructures. Thermodynamic compatibility and conventional microstructure-mechanical property studies make up the bulk of the papers as they address a large deficiency in our understanding in this important area.

Anton, D.L. (United Technologies Research Center, East Hartford, CT (US)); Martin, P.L. (Rockwell International Science Center, Thousand Oaks, CA (US)); Miracle, D.B. (Wright Research and Development Center, Wright-Patterson Air Force Base, OH (US)); McMeeking, R. (Univ. of California, Santa Barbara, CA (US))

1990-01-01

68

Generalized matrix inversion is not harder than matrix multiplication  

NASA Astrophysics Data System (ADS)

Starting from the Strassen method for rapid matrix multiplication and inversion as well as from the recursive Cholesky factorization algorithm, we introduced a completely block recursive algorithm for generalized Cholesky factorization of a given symmetric, positive semi-definite matrix . We used the Strassen method for matrix inversion together with the recursive generalized Cholesky factorization method, and established an algorithm for computing generalized {2,3} and {2,4} inverses. Introduced algorithms are not harder than the matrix-matrix multiplication.

Petkovic, Marko D.; Stanimirovic, Predrag S.

2009-08-01

69

Nonnegative matrix factorization with ?-divergence  

Microsoft Academic Search

Nonnegative matrix factorization (NMF) is a popular technique for pattern recogni- tion, data analysis, and dimensionality reduction, the goal of which is to decompose nonnegative data matrix X into a product of basis matrix A and encoding variable matrix S with both A and S allowed to have only nonnegative elements. In this paper we consider Amari's ?-divergence as a

Andrzej Cichocki; Hyekyoung Lee; Yong-Deok Kim; Seungjin Choi

2006-01-01

70

Matrix lattice Boltzmann reloaded.  

PubMed

The lattice Boltzmann equation was introduced about 20 years ago as a new paradigm for computational fluid dynamics. In this paper, we revisit the main formulation of the lattice Boltzmann collision integral (matrix model) and introduce a new two-parametric family of collision operators, which permits us to combine enhanced stability and accuracy of matrix models with the outstanding simplicity of the most popular single-relaxation time schemes. The option of the revised lattice Boltzmann equation is demonstrated through numerical simulations of a three-dimensional lid-driven cavity. PMID:21536566

Karlin, Ilya; Asinari, Pietro; Succi, Sauro

2011-06-13

71

Tripartite neutrino mass matrix  

NASA Astrophysics Data System (ADS)

The 3×3 Majorana neutrino mass matrix is written as a sum of 3 terms, i.e., M?=MA+MB+MC, where MA is proportional to the identity matrix and MB,C are invariant under different Z3 transformations. This M? is very suitable for understanding atmospheric and solar neutrino oscillations, with sin22?atm and tan2?sol fixed at 1 and 0.5 respectively, in excellent agreement with present data. It has in fact been proposed before, but only as an ansatz. This Letter uncovers its underlying symmetry, thus allowing a complete theory of leptons and quarks to be constructed.

Ma, Ernest

2004-03-01

72

Lung Histology Rules Matrix  

Cancer.gov

Lung Histo Lung Histology Coding Rules – Matrix C340-C349 (Excludes lymphoma and leukemia M9590 – 9989 and Kaposi sarcoma M9140) Rule Pathology/Cytology Specimen Histology Behavior Notes and Examples Code SINGLE TUMOR H1 No pathology/cytology

73

Micro matrix data marking  

US Patent & Trademark Office Database

The invention provides methods and systems for the application and reading of micro markings for coding of information for placement on the surfaces of individual very small devices. In preferred embodiments, a two dimensional micro matrix of markings or dots is realized on a scale of a 25 um cell size and smaller.

Blackall; Eric (Richardson, TX); Teggatz; Ross (McKinney, TX)

2013-10-08

74

Matrix and Tensor Decompositions  

NASA Astrophysics Data System (ADS)

Advances in high-throughput technologies such as gene and protein expression microarrays in the past decade have made it possible to simultaneously measure the expression levels of thousands of transcripts. This has resulted in large amounts of biological data requiring analysis and interpretation. Many methods for handling such large-scale data have been proposed in the literature. For example, consider a p ×n gene expression matrix V consisting of observations on p genes from n samples representing different experimental conditions, phenotypes or time points. One could be interested in identifying clusters of genes with similar expression profiles across sub-groups of samples. Typically, this is accomplished via a decomposition of V into two or more matrices where each factored matrix has a distinct physical interpretation. Matrix decompositions have been successfully utilized in a variety of applications in computational biology such as molecular pattern discovery, class comparison, class prediction, functional characterization of genes, cross-platform and cross-species analysis, and biomedical informatics. In this chapter, we focus on available and commonly utilized methods for such matrix decompositions as well as survey other potentially useful methods for analyzing highdimensional data.

Devarajan, Karthik

75

Probabilistic Matrix Factorization  

Microsoft Academic Search

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

Ruslan Salakhutdinov; Andriy Mnih

2007-01-01

76

Miniature active matrix display  

Microsoft Academic Search

The objective of this program was the development of fabrication methods for an active matrix, flat panel TV display with a resolution of at least 400 elements per linear inch. The feasibility of such a high-resolution, solid-state, flat panel screen was demonstrated for the first time using thin film electroluminescence as the display media. A resolution of 500 lines per

R. D. Ketchpel

1978-01-01

77

The Reading Matrix  

NSDL National Science Digital Library

In the fall of 2000, a group of concerned educators came together to form The Reading Matrix, which was designed to create a place where both teachers and other interested persons could come together to find resources about reading and writing. Most of the resources are geared towards the language needs of ESL and international students, but given the cornucopia of materials here, there is really something for everyone. Scrolling down from the site’s homepage, visitors will come across areas that include a job database, the Reading Matrix Archives, interactive reading exercises, and a list of germane online journals. The Archives are a good place to start, as users will have the opportunity to look through subject-oriented resources for English-language learners that range from dictionaries, grammar quizzes, and speaking and listening practice.

78

Matrix string theory  

Microsoft Academic Search

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

Robbert Dijkgraaf; Erik Verlinde; Herman L Verlinde

1997-01-01

79

Dynamical matrix in magnetoelectrics  

NASA Astrophysics Data System (ADS)

In ordinary dielectrics the dynamical matrix at the zone center is a nonanalytic function of degree zero in the wavevector q. Its expression (for a crystal of arbitrary symmetry) is well known and is routinely implemented in first principle calculations. The nonanalytic behavior occurs in polar crystals and owes to the coupling of the macroscopic electric field E to the lattice. In magnetoelectric crystals both electric and magnetic fields, E and H, are coupled to the lattice, formally on equal footing. I provide the general expression for the zone center dynamical matrix in a magnetoelectric, where the E and H couplings are accounted for in a symmetric way. As in the ordinary case, the dynamical matrix is a nonanalytic function of degree zero in q, and is exact in the harmonic approximation. Besides the above major result, I will also discuss other related issues: (i) The Lyddane-Sachs-Teller relationship for MEs, where the fields E and H are (once more) dealt with in a symmetric way; (ii) The microscopic origin of the coupling of magnetic fields to the lattice, which may look counterintuitive; (iii) The relationship to first-principle implementations, where in the simplest cases E and B (not H) are zero.

Resta, Raffaele

2012-02-01

80

Cholesky Factorization and Matrix Inversion.  

National Technical Information Service (NTIS)

The Cholesky square root algorithm used in the solution of linear equations with a positive definite matrix of coefficients is developed by elementary matrix algebra, independent of the Gaussian elimination from which it was originally derived. The Choles...

E. Schmid

1973-01-01

81

Matrix Organizations: Overcoming the Disadvantages.  

National Technical Information Service (NTIS)

This paper a background on the matrix management organizational structure. The author identifies typical disadvantages of the matrix organization with the focus on project and functional managers, functional experts, and project teams. Various techniques ...

H. E. Berg

1984-01-01

82

Distributive Property Matrix Multiplication (1)  

NSDL National Science Digital Library

This interactive Java learning tool allows a teacher to demonstrate and explore the distributive property with expressions in the factored form (a + b) (c + d) using a matrix multiplication method with students. Sliders determine the number values from 20 to -20 with increments of one-tenth. Check boxes show or hide the factored form, starting matrix values, matrix, products in the matrix, and solution.

Tierney-Fife, Peter

2009-02-20

83

On the Matrix Exponential Function  

ERIC Educational Resources Information Center

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

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

2006-01-01

84

Matrix Nearness Problems and Applications  

Microsoft Academic Search

A matrix nearness problem consists of finding, for an arbitrary matrix A, a nearest member of some given class of matrices, where distance is measured in a matrix norm. A survey of nearness problems is given, with particular emphasis on the fundamental properties of symmetry, positive definiteness, orthogonality, normality, rank-deficiency and instability. Theoretical results and computational methods are described. Applications

Nicholas J. Higham

1989-01-01

85

Response matrix of symmetric nodes  

Microsoft Academic Search

Properties of a symmetric node's response matrix are discussed. The node may have an internal structure such that it remains invariant under the symmetry transformations of the considered node. A transformation diagonalizing the response matrix is given by means of symmetry considerations. The equivalence is demonstrated of the response matrix method to a finite difference scheme in which the dependent

Makai

1984-01-01

86

The gravitational S matrix  

SciTech Connect

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

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

2010-01-15

87

Epigenetics within the matrix  

PubMed Central

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

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

2012-01-01

88

Matrix membranes and integrability  

SciTech Connect

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

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

1997-06-01

89

Google matrix of Twitter  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

90

Mixed Mode Matrix Multiplication  

SciTech Connect

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

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

2004-09-30

91

Hyaluronan: A Matrix Component  

NASA Astrophysics Data System (ADS)

The glucosaminoglycan hyaluronan is a key component of the extracellular matrix. It is a large, negatively charged molecule that can act as an ion exchange reservoir for positive ions. Hyaluronan is involved in renomedullary water handling through its water-binding capacity. In the renal medulla, the main source for hyaluronan production is the renomedullary interstitial cells. Hyaluronan synthases are found in the inner part of the plasma membrane and polymerize hyaluronan chains which are extruded into the extracellular space. Hyaluronidases are a family of enzymes involved in the degradation of hyaluronan. They have a wide range of properties, including differences in size, inhibitor sensitivities, catalytic mechanisms, substrate specificities and pH optima.

Rügheimer, Louise

2008-09-01

92

Platelets and matrix metalloproteinases.  

PubMed

Matrix metalloproteinases (MMPs) and their inhibitors essentially contribute to a variety of pathophysiologies by modulating cell migration, tissue degradation and inflammation. Platelet-associated MMP activity appears to play a major role in these processes. First, platelets can concentrate leukocyte-derived MMP activity to sites of vascular injury by leukocyte recruitment. Second, platelets stimulate MMP production in e.g. leukocytes, endothelial cells, or tumour cells by direct receptor interaction or/and by paracrine pathways. Third, platelets synthesise and secrete a variety of MMPs including MMP-1, MMP-2, MMP-3, and MMP-14 (MT1-MMP), and potentially MMP-9 as well as the tissue inhibitors of metalloproteinase (TIMPs). This review focuses on platelet-derived and platelet-induced MMPs and their inhibitors. PMID:23864155

Seizer, P; May, A E

2013-07-18

93

Polynomial supersymmetry for matrix Hamiltonians  

NASA Astrophysics Data System (ADS)

We study intertwining relations for matrix non-Hermitian Hamiltonians by matrix differential operators of arbitrary order. It is established that for any intertwining operator of minimal order there is operator that intertwines the same Hamiltonians in the opposite direction and such that the products of these operators are identical polynomials of the corresponding Hamiltonians. The related polynomial algebra of supersymmetry is constructed. The problems of minimization and reducibility of a matrix intertwining operator are considered and the criteria of minimizability and reducibility are presented. It is shown that there are absolutely irreducible matrix intertwining operators, in contrast to the scalar case.

Sokolov, A. V.

2013-03-01

94

Matrix cracking and debonding of ceramic-matrix composites  

Microsoft Academic Search

The effects of matrix cracking and debonding which occur in ceramic-matrix composites are described by a micromechanical model. The cracking and debonding processes induce loss of stiffness, inelastic strains, hysteresis loops and crack closure. These features are analysed within the framework of Continuum Mechanics by the introduction of internal variables identified in the micromechanical analysis. The evolution laws of the

Frederick A. Leckie

1996-01-01

95

Matrix dominated time dependent failure predictions in polymer matrix composites  

Microsoft Academic Search

Various types of matrix dominated failures in polymer matrix composites (PMC) are reviewed. Current methods to evaluate the modulus degradation of PMC materials are discussed including viscoelastic\\/plastic and continuum damage models. It is pointed out that in each case the approach is based upon developing an analytical constitutive relation for the material in order to represent a measured stress–strain response.

Hal F. Brinson

1999-01-01

96

Glass matrix armor  

DOEpatents

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

Calkins, Noel C. (Los Alamos, NM)

1991-01-01

97

Matrix solid-phase dispersion  

Microsoft Academic Search

Matrix solid-phase dispersion (MSPD) is a patented process, first reported in 1989, for conducting simultaneous disruption and extraction of solid and semi-solid samples. MSPD permits complete fractionation of the sample matrix components as well as the ability to selectively elute a single compound or several classes of compounds from the same sample. The method has been applied to the isolation

Steven A Barker

2000-01-01

98

Matrix solid phase dispersion (MSPD)  

Microsoft Academic Search

A review of the many uses of matrix solid phase dispersion (MSPD) in the extraction and analysis of a variety of compounds from a range of samples is provided. Matrix solid phase dispersion (MSPD) has found particular application as a somewhat generic analytical process for the preparation, extraction and fractionation of solid, semi-solid and\\/or highly viscous biological samples. Its simplicity

Steven A. Barker

2007-01-01

99

How to Study a Matrix  

ERIC Educational Resources Information Center

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

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

2012-01-01

100

Fatigue of ceramic matrix composites  

Microsoft Academic Search

Fatigue in ceramic matrix composites typically occurs when matrix cracks are present. It proceeds by cyclic degradation of the sliding resistance of the interface. The basic mechanisms are discussed and a methodology is developed that enables fatigue life predictions to be made, based on a minimum number of experimental measurements. The methodology relies on analysis of hysteresis loops. Changes in

A. G. Evans; F. W. Zok; R. M. McMeeking

1995-01-01

101

How to Study a Matrix  

ERIC Educational Resources Information Center

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

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

2012-01-01

102

Bulk metallic glass matrix composites  

SciTech Connect

Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol{percent} fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. {copyright} {ital 1997 American Institute of Physics.}

Choi-Yim, H.; Johnson, W.L. [W. M. Keck Laboratory of Engineering Materials, Mail Code 138-78, California Institute of Technology, Pasadena, California 91125 (United States)

1997-12-01

103

Optimized matrix inversion technique for the T-matrix method.  

PubMed

We suggest a new approach to calculate the inverse matrix in scattering calculations using the T-matrix method. Instead of inversion of the full matrix, we suggest the inversion of two matrices, each of which contains half the number of rows. This approach allows significant time savings and a noticeable increase of the precision of scattering calculations due to fewer arithmetical operations. An iterative method can be applied to matrices whose dimension is also divisible by factors of 2, which can further increase the time savings and accuracy. PMID:17410271

Petrov, Dmitry; Shkuratov, Yuriy; Videen, Gorden

2007-05-01

104

New Chorus Diffusion Matrix  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

105

Filament-Matrix Interactions in Metal Matrix Composites, 9.  

National Technical Information Service (NTIS)

The potential of metal matrix composites is discussed, after an introduction to the underlying principles of fiber reinforcement. A brief review of the present status of the micromechanical theory of composite behavior illustrates the relatively primitati...

L. D. Blackburn H. M. Burte F. R. Bonanno

1966-01-01

106

Genotype imputation via matrix completion.  

PubMed

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

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

2012-12-10

107

Evaluation of Stone Matrix Asphalt.  

National Technical Information Service (NTIS)

This report documents a study that evaluated the mixture properties and field performance of stone matrix asphalt (SMA) mixtures. The study included a review of European practices and initial U.S. experiences with SMA design and construction. SMA mixtures...

J. E. Shoenberger L. N. Godwin P. A. Gilbert L. N. Lynch

1997-01-01

108

Performance Appraisal for Matrix Management.  

ERIC Educational Resources Information Center

A matrix management system designed for use by a highly technical nuclear weapons research and development facility to improve productivity and flexibility by the use of multiple authority, responsibility, and accountability relationships is described. (MSE)

Edwards, M. R.; Sproull, J. Ruth

1985-01-01

109

Performance Appraisal for Matrix Management.  

ERIC Educational Resources Information Center

|A matrix management system designed for use by a highly technical nuclear weapons research and development facility to improve productivity and flexibility by the use of multiple authority, responsibility, and accountability relationships is described. (MSE)|

Edwards, M. R.; Sproull, J. Ruth

1985-01-01

110

Thermally Conductive Polymer Matrix Composites  

Microsoft Academic Search

\\u000a Thermally conductive polymer matrix composites are used increasingly for thermal management of electronic packaging system.\\u000a The polymer matrix includes both thermosetting and thermoplastic types. Different kinds of fillers or reinforcements have\\u000a been developed to process composite materials with desired thermal, mechanical, and electrical properties. Reinforcement fillers\\u000a have an important role to play in maximizing polymer performance and production efficiency. Cost

Xingcun Colin Tong

111

Pole Allocation using Matrix Perturbations  

Microsoft Academic Search

An approach is presented for the analysis and design of controllers and observers for high-dimensional systems using pole allocation and matrix perturbation theory. Development of a feedback control law that leads to a desired closed-loop configuration is a prohibitive task computationally, especially for large-order systems. Existing pole allocation algorithms can handle only low-order models. In this paper, matrix perturbation theory

H. Baruh; Departmentof MechanicalandAerospace

1986-01-01

112

Molybdenum disilicide alloy matrix composite  

DOEpatents

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

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

1991-12-03

113

Molybdenum disilicide alloy matrix composite  

DOEpatents

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

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

1990-01-09

114

The Extracellular Matrix: An Overview  

Microsoft Academic Search

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

Jeffrey H. Miner

115

Matrix models with ?string>0  

NASA Astrophysics Data System (ADS)

Within the framework of c=1 matrix models, we consider multi-matrix models, i.e. the quantum mechanics of multi-matrix models. A connection is established between a D-matrix model and a D-dimensional gas of fermions (bosons) for odd (even) values of D. A statistical mechanical analysis yields the scaling law for the free energy, and hence the susceptibility exponents for the various models. The exponents turn out to be positive for the multi-matrix models, suggesting that these could represent models of 2D gravity coupled to c>1 matter. However, a lower-bound on the mass-gap exponents is found (i.e. an upper bound on the Hausdroff dimension) which may render this identification unlikely. Nevertheless, we find certain qualitative features which would be expected of a c>1 theory. For instance, in addition to the positive susceptibility exponent, we find that whereas in the c=1 case the density of states itself diverges as one approaches the critical point, in the D-matrix models various derivatives of the density of states diverge, with the order of the derivative depending on D. This qualitatively different behaviour of the density of states could be a signal of the conjectured ``phase transition'' at c=1.

Marzban, Caren; Raju Viswanathan, R.

1992-03-01

116

Hyaluronan-Dependent Pericellular Matrix  

PubMed Central

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.

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

2007-01-01

117

Cast data matrix symbols performance characterization  

Microsoft Academic Search

Data matrix symbols are used as a robust means of unique part identification in many industries. Research of cast data matrix symbols has been limited and expected symbol performance unknown. To develop knowledge of cast data matrix symbol performance, the investigation initially focused on feasibility of casting data matrix symbol. Results of a feasibility experiment led to further investigation of

Greg Carl Saveraid

2010-01-01

118

Iterative Optimal Orthogonalization of the Strapdown Matrix  

Microsoft Academic Search

This paper treats the problem of finding an orthogonal matrix which is the closest, in the Forbenius norm, to a given nonorthogonal matrix. This nonorthogonal matrix is the result of a fast but rather inaccurate computation of the well-known direction cosine matrix (DCM) of a strapdown inertial navigation system. The known closed-form solution to this problem is rederived using the

Itzhack Bar-Itzhack

1975-01-01

119

Progress in matrix metalloproteinase research  

PubMed Central

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

Murphy, Gillian; Nagase, Hideaki

2010-01-01

120

The HDTV digital audio matrix  

NASA Astrophysics Data System (ADS)

Multichannel sound systems are being studied as part of the Eureka 95 and Radio-communication Bureau TG10-1 investigations into high definition television. One emerging sound system has five channels; three at the front and two at the back. This raises some compatibility issues. The listener might have only, say, two loudspeakers or the material to be broadcast may have fewer than five channels. The problem is how best to produce a set of signals to be broadcast, which is suitable for all listeners, from those that are available. To investigate this area, a device has been designed and built which has six input channels and six output channels. Each output signal is a linear combination of the input signals. The inputs and outputs are in AES/EBU digital audio format using BBC-designed AESIC chips. The matrix operation, to produce the six outputs from the six inputs, is performed by a Motorola DSP56001. The user interface and 'housekeeping' is managed by a T222 transputer. The operator of the matrix uses a VDU to enter sets of coefficients and a rotary switch to select which set to use. A set of analog controls is also available and is used to control operations other than the simple compatibility matrixing. The matrix has been very useful for simple tasks: mixing a stereo signal into mono, creating a stereo signal from a mono signal, applying a fixed gain or attenuation to a signal, exchanging the A and B channels of an AES/EBU bitstream, and so on. These are readily achieved using simple sets of coefficients. Additions to the user interface software have led to several more sophisticated applications which still consist of a matrix operation. Different multichannel panning laws have been evaluated. The analog controls adjust the panning; the audio signals are processed digitally using a matrix operation. A digital SoundField microphone decoder has also been implemented. matrix operation, the analog controls being used to adjust the characteristics of the decoded microphone. &DSP software for specific tasks not requiring operator control has also been used. Adaptive filtering and signal restoration are two examples. The transputer in this case can be left to perform the housekeeping. *The design of the HDTV digital audio matrix is such that it can be applied to a wide variety of signal processing tasks. -The combination of a dedicated DSP chip programmed in assembly language for speed of operation and a general purpose processor for user interface tasks programmed in a high level language has been found to be extremely useful.

Mason, A. J.

121

Integrated electrooptic Bragg modulator modules for matrix-vector and matrix-matrix multiplications.  

PubMed

Successful fabrication of high performance microlenses and microlens arrays using the titanium-indiffusion and proton-exchange technique has enabled realization of a variety of integrated electrooptic Bragg modulator modules in the LiNbO(3) channel-planar composite waveguides of 0.2- x 1.0- x 1.8-cm(3) substrate size. These integrated optic device modules have been utilized successfully to perform matrix-vector and matrix-matrix multiplications. Through the channel-waveguide and the linear microlens arrays, the very large channel capacities that are inherent in the diode laser and the optical fiber as well as the photodotcctor arrays may be conveniently exploited. Consequently, such integrated optic device modules should facilitate realization of multichannel optical computing as well as communication and rf signal processing systems. PMID:20531652

Le, P; Zang, D Y; Tsai, C S

1988-05-01

122

Active matrix molecular OLED microdisplays  

Microsoft Academic Search

Organic light emitting device (OLED) technology provides significant benefits to the realization of active matrix microdisplays for a number of commercial applications. This paper reviews the technology attributes of OLED in the microdisplay context as well as the business opportunities they enable. The design and structure of an SXGA format OLED microdisplay is then presented and the experimental results obtained

O Prache

2001-01-01

123

Benign Brain Histology Rules matrix  

Cancer.gov

Benign and Borderline Intracranial and CNS Tumors Histology Coding Rules – Matrix C700, C701, C709, C710-C719, C720-C725, C728, C729, C751-C753 Note: Malignant intracranial and CNS tumors have a separate set of rules. Rule Pathology/Cytology Specimen

124

Matrix metalloproteinases and oral cancer  

Microsoft Academic Search

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

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

1999-01-01

125

Cache-Efficient Matrix Transposition  

Microsoft Academic Search

We investigate the memory system performance of several algorithms for transposing an matrix in-place, where is large. Specifically, we investi- gate the relative contributions of the data cache, the translation lookaside buffer, register tiling, and the array layout function to the overall running time of the algorithms. We use various memory models to capture and analyze the effect of various

Siddhartha Chatterjee; Sandeep Sen

2000-01-01

126

Matrix converters: a technology review  

Microsoft Academic Search

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

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

2002-01-01

127

PARTICIPATORY DEPENDENCE STRUCTURE MATRIX APPROACH  

Microsoft Academic Search

Dependence Structure Matrix (DSM) has been shown to be an important and effective tool in managing complex projects through its focus on analyzing relations and dependencies. Three major outcomes of DSM analysis can be identified. The first is the design of an integrated or modular product structure based on relations among components in a product architecture or design parameters. The

Mike Danilovic; Håkan Börjesson

128

Algorithms for Nonnegative Matrix Factorization  

Microsoft Academic Search

Non-negative matrix factorization (NMF) has previously been shown to be a useful decomposition for multivariate data. Two different multi- plicative algorithms for NMF are analyzed. They differ only slightly in the multiplicative factor used in the update rules. One algorithm can be shown to minimize the conventional least squares error while the other minimizes the generalized Kullback-Leibler divergence. The monotonic

Daniel D. Lee; H. Sebastian Seung

2000-01-01

129

Polymer derived ceramic matrix composites  

Microsoft Academic Search

Preceramic polymers offer a unique method to fabricate ceramic matrix composites (CMC). Relatively large and complex shapes were fabricated using a polysilazane polymer and silicon carbide based reinforcements of CG Nicalon™ and HI-nicalon™ fibers. This paper summarizes a raw material system and the fabrication process used to prepare two-dimensional cloth reinforced composites. Typical tensile, shear and compressive properties of CMCs

R. Jones; A. Szweda; D. Petrak

1999-01-01

130

Disorders of lung matrix remodeling  

PubMed Central

A set of lung diseases share the tendency for the development of progressive fibrosis ultimately leading to respiratory failure. This review examines the common pathogenetic features of these disorders in light of recent observations in both humans and animal models of disease, which reveal important pathways of lung matrix remodeling.

Chapman, Harold A.

2004-01-01

131

Matrix Completion from Noisy Entries  

Microsoft Academic Search

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

Raghunandan H. Keshavan; Andrea Montanari; Sewoong Oh

2009-01-01

132

Matrix Representation of Evolving Networks  

NASA Astrophysics Data System (ADS)

We present the distance matrix evolution for different types of networks: exponential, scale-free and classical random ones. Statistical properties of these matrices are discussed as well as topological features of the networks. Numerical data on the degree and distance distributions are compared with theoretical predictions.

Malarz, K.; Ku?akowski, K.

2005-08-01

133

Resonances for matrix Schrödinger operators  

Microsoft Academic Search

We study the resonances of matrix Schrödinger operators,\\u000amotivated by the Born-Oppenheimer approximation. We give a simple\\u000acriterion for the potential to generate resonances. This criterion\\u000aalso gives the location of the resonances generated.

L. Nedelec

2001-01-01

134

The OSS On-line Resource Directory/National Science Education Standards ``Quilt"/Science Concepts Matrix: Useful Tools for E/PO  

NASA Astrophysics Data System (ADS)

NASA Office of Space Science has developed a ``suite of tools" to enable scientists, educators, and the general public locate various NASA materials. The first, called the Space Science Resource Directory (Dr. Terry Teays and Carol Rest), is an on-line database of Internet-based space science educational resources that can be used in classrooms, science museums, planetariums, and other settings. The second, called the National Science Education Standards ``Quilt" (Art Hammon and Becky Knudsen, JPL) is a matrix which allows you to search for space science curriculum resources according to the National Science Education Standard they address. The third, called the Overarching Science Concepts Matrix (Dr. Robert Gabrys, GSFC), is a comprehensive representation of all NASA Office of Space Science concepts, cross-referenced in a tabular display with the overarching science topics that would be necessary for the student to learn in order to understand the particular space science concept. All three tools can be used to assist scientists as they consult in the development of educational products and/or give presentations to the educational or general public community. They are presently in their preliminary stages of development, and will continue in their growth and expansion to become even more inclusive than they are at present.

Knudsen, R.; Hammon, A.; NASA Solar System Exploration Education and Public Outreach Forum Team; NASA Origins Education and Public Outreach Forum Team; NASA Goddard Space Flight Center Office of Education Team

2001-11-01

135

Scrambling with matrix black holes  

NASA Astrophysics Data System (ADS)

If black holes are not to be dreaded sinks of information but rather fully described by unitary evolution, they must scramble in-falling data and eventually leak it through Hawking radiation. Sekino and Susskind have conjectured that black holes are fast scramblers; they generate entanglement at a remarkably efficient rate, with the characteristic time scaling logarithmically with the entropy. In this work, we focus on Matrix theory—M-theory in the light-cone frame—and directly probe the conjecture. We develop a concrete test bed for quantum gravity using the fermionic variables of Matrix theory and show that the problem becomes that of chains of qubits with an intricate network of interactions. We demonstrate that the black hole system evolves much like a Brownian quantum circuit, with strong indications that it is indeed a fast scrambler. We also analyze the Berenstein-Maldacena-Nastase model and reach the same tentative conclusion.

Brady, Lucas; Sahakian, Vatche

2013-08-01

136

Extracellular Matrix and Heart Development  

PubMed Central

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

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

2011-01-01

137

Radiation resistant ceramic matrix composites  

Microsoft Academic Search

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

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

1997-01-01

138

Vascular extracellular matrix in atherosclerosis.  

PubMed

The extracellular matrix (ECM) is an essential component of the human body that is responsible for the proper function of various organs. Changes in the ECM have been implicated in the pathogenesis of several cardiovascular conditions including atherosclerosis, restenosis, and heart failure. Matrix components, such as collagens and noncollagenous proteins, influence the function and activity of vascular cells, particularly vascular smooth muscle cells and macrophages. Matrix proteins have been shown to be implicated in the development of atherosclerotic complications, such as plaque rupture, aneurysm formation, and calcification. ECM proteins control ECM remodeling through feedback signaling to matrix metalloproteinases (MMPs), which are the key players of ECM remodeling in both normal and pathological conditions. The production of MMPs is closely related to the development of an inflammatory response and is subjected to significant changes at different stages of atherosclerosis. Indeed, blood levels of circulating MMPs may be useful for the assessment of the inflammatory activity in atherosclerosis and the prediction of cardiovascular risk. The availability of a wide variety of low-molecular MMP inhibitors that can be conjugated with various labels provides a good perspective for specific targeting of MMPs and implementation of imaging techniques to visualize MMP activity in atherosclerotic plaques and, most interestingly, to monitor responses to antiatheroslerosis therapies. Finally, because of the crucial role of ECM in cardiovascular repair, the regenerative potential of ECM could be successfully used in constructing engineered scaffolds and vessels that mimic properties of the natural ECM and consist of the native ECM components or composite biomaterials. These scaffolds possess a great promise in vascular tissue engineering. PMID:23422022

Chistiakov, Dimitry A; Sobenin, Igor A; Orekhov, Alexander N

139

Regularization in matrix relevance learning.  

PubMed

In this paper, we present a regularization technique to extend recently proposed matrix learning schemes in learning vector quantization (LVQ). These learning algorithms extend the concept of adaptive distance measures in LVQ to the use of relevance matrices. In general, metric learning can display a tendency towards oversimplification in the course of training. An overly pronounced elimination of dimensions in feature space can have negative effects on the performance and may lead to instabilities in the training. We focus on matrix learning in generalized LVQ (GLVQ). Extending the cost function by an appropriate regularization term prevents the unfavorable behavior and can help to improve the generalization ability. The approach is first tested and illustrated in terms of artificial model data. Furthermore, we apply the scheme to benchmark classification data sets from the UCI Repository of Machine Learning. We demonstrate the usefulness of regularization also in the case of rank limited relevance matrices, i.e., matrix learning with an implicit, low-dimensional representation of the data. PMID:20236882

Schneider, Petra; Bunte, Kerstin; Stiekema, Han; Hammer, Barbara; Villmann, Thomas; Biehl, Michael

2010-03-15

140

Developments in eastern Canada in 1979. [Tabular data and maps  

SciTech Connect

In Eastern Canada 245 wells, not including 10 lost holes, were drilled for oil and gas during 1979. Of this total, 90 wells were classed as exploratory, 144 as development, and 11 were drilled for various service and storage purposes. The total meterage drilled in Eastern Canada amounted to 177,623.3. The production of natural gas in Eastern Canada increased 29.4% in 1979, whereas oil production dropped 1.2%. A total of approximately 399,353,200 cu m of natural gas and 96,1186.6 cu m of oil was produced from southwestern Ontario and New Brunswick. Additional production from Lake Erie, coming on stream, accounted for the rise in natural gas production figures. All phases of exploration increased in Quebec, the Maritimes, and Atlantic offshore during 1979; 23 exploratory wells were completed, 2 of which had been suspended in 1978. This represents a 61.5% increase in exploratory drilling for the area. In southwestern Ontario, 67 exploratory and 144 development wells, not including 10 lost holes, were drilled in 1979. The overall success rate for southwestern Ontario for 1979 was 42.1%, down 5.2% from 1978. An increase in development drilling in Lake Erie (up 63.8%), accompanied by an even greater percentage of offshore development dry holes, accounted for the decline in the overall success ratio. This trend may continue, as it is anticipated that the 1980 drilling season in Ontario will surmount that of 1979.

Robertson, D.C. (Petroleum Resources Lab., London, Ontario); Bryant, R.G.; Roliff, W.A.

1980-09-01

141

Developments in New York in 1979. [Tabular data and map  

Microsoft Academic Search

In 1979, an estimated 623 wells were completed in New York. In existing fields, 172 oil and 370 gas wells were completed. Exploratory drilling resulted in 12 new gas-field discoveries, 1 deeper pool gas discovery, and 27 extensions to existing gas fields. Two discoveries were in the Lower Devonian Oriskany Sandstone, one along the Oriskany pinch-out and the other on

Van Tyne

1980-01-01

142

In situ Leaching of Tabular Metalliferous Ore Deposits.  

National Technical Information Service (NTIS)

This report describes the progress of laboratory studies on in situ leaching of sulfide and native copper ores of Michigan. Tests on pure copper have shown that leaching is diffusion controlled and that under certain conditions cuprous oxide will precipit...

W. A. Hockings W. L. Freyberger

1974-01-01

143

Formal semantics for tabular expressions and Software Cost Reduction method  

Microsoft Academic Search

Unambiguous and precise software specification can not be achieved without some use of formal notation. Table-based specification techniques are both readable and convenient. They allow the representation of systems specifications in a very compact and yet precise manner. They scale to software systems, and they may be easily used even by people unfamiliar with the application domain. Additionally, the use

Imene Bourguiba

2011-01-01

144

AMPLIFY™ rhBMP-2 Matrix  

Center for Biologics Evaluation and Research (CBER)

Text Version... Two packages of two 5cc matrices Page 7. ... Matrix Ceramic block CRM Ceramic block ... Page 24. AMPLIFYTM Matrix clinical study design – cont'd ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials

145

Oriented Nanofibers Embedded in Polymer Matrix.  

National Technical Information Service (NTIS)

A method of forming a composite of embedded nanofibers in a polymer matrix is disclosed. The method includes incorporating nanofibers in a plastic matrix forming agglomerates, and uniformly distributing the nanofibers by exposing the agglomerates to hydro...

D. H. Stewart E. V. Barrera F. J. Rodriguez-Macias K. Lozano L. P. F. Chibante

2000-01-01

146

Zero asymptotic behaviour for orthogonal matrix polynomials  

Microsoft Academic Search

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

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

1999-01-01

147

Nonnegative matrix factorization with alpha-divergence  

Microsoft Academic Search

Non-negative matrix factorization (NMF) is a popular technique for pattern recognition, data analysis, and dimensionality reduction, the goal of which is to decompose non-negative data matrix X into a product of basis matrix A and encoding variable matrix S with both A and S allowed to have only non-negative elements. In this paper, we consider Amari’s ?-divergence as a discrepancy

Andrzej Cichocki; Hyekyoung Lee; Yong-deok Kim; Seungjin Choi

2008-01-01

148

Sparse Matrix Computations on Parallel Processor Arrays  

Microsoft Academic Search

Weinvestigate the balancing of distributed compressed storage of large sparse matrices on a massively parallel computer. For fast computation of matrix#vector and matrix#matrix products on a rectangular processor array with e#cient communications along its rows and columns we require that the nonzero elements of each matrix row or column be distributed among the processors located within the same array row

Andrew T. Ogielski; William Aiello

1992-01-01

149

Algorithm for Rescaling a Matrix Positive Definite.  

National Technical Information Service (NTIS)

For a given square real matrix M, we present a general algorithm which decides the existence of a positive diagonal matrix D such that DM is positive definite and which constructs the D if it exists. It is shown that solving this matrix rescaling problem ...

H. Hu

1986-01-01

150

Algorithm for Rescaling a Matrix Positive Definite.  

National Technical Information Service (NTIS)

For a given square real matrix M, a general algorithm is given which decides the existence of a positive diagonal matrix D such that DM is positive definite and which constructs the D if it exists. It is shown that solving this matrix rescaling problem is...

H. Hu

1986-01-01

151

Analytic approximation of matrix functions in Lp  

Microsoft Academic Search

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

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

2009-01-01

152

Ceramic matrix composite-metal brazed joints  

Microsoft Academic Search

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

D. G. Dixon

1995-01-01

153

Creep of plain weave polymer matrix composites  

Microsoft Academic Search

Polymer matrix composites are increasingly used in various industrial sectors to reduce structural weight and improve performance. Woven (also known as textile) composites are one class of polymer matrix composites with increasing market share mostly due to their lightweight, their flexibility to form into desired shape, their mechanical properties and toughness. Due to the viscoelasticity of the polymer matrix, time-dependent

Abhishek Gupta

2010-01-01

154

Matrix metalloproteinases and the immune response  

Microsoft Academic Search

The timely breakdown of the extracellular matrix (ECM) is essential in many physiological and biological processes. The matrix-degradation process involves tissue remodeling and immune\\/inflammatory reactions that occur in the stroma. Thus, the proteolytic and destructive potential of the matrix metalloproteinase (MMP) family is a major concern in several pathological conditions involving ECM degradation. This review details the structures and functions

Kristina A Szabo; Richard J Ablin; Gurmit Singh

2004-01-01

155

Distribution of matrix elements of chaotic systems  

Microsoft Academic Search

When a quantum system has a chaotic classical analog, its matrix elements in the energy representation are closely related to various microcanonical averages of the classical system. The diagonal matrix elements cluster around the classical expectation values, with fluctuations similar to the values of the off-diagonal matrix elements. The latter in turn are related to the classical autocorrelations. These results

Mario Feingold; Asher Peres

1986-01-01

156

Bayesian Inference for a Covariance Matrix  

Microsoft Academic Search

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

Tom Leonard; John S. J. Hsu

1992-01-01

157

Matrix ENDOR of Polyenyl Radicals in Polymers.  

National Technical Information Service (NTIS)

EPR and matrix ENDOR spectra have been examined for polyenyl radicals in gamma-irradiated PVF, PVF2, PVC, and PMMA polymers. Proton matrix ENDOR is observed for all four polymers, and fluorine matrix ENDOR for PVF and PVF2. By line shape analysis of the E...

J. N. Helbert B. E. Wagner E. H. Poindexter L. Kevan

1974-01-01

158

Conditions for matrix crack deflection at an interface in ceramic matrix composites  

Microsoft Academic Search

This paper describes a numerical approach developed to simulate the mechanism of matrix crack deflection at the fibre\\/matrix interface in brittle matrix composites. For this purpose, the fracture behaviour of a unit cell (microcomposite) consisting of a single fibre surrounded by a cylindrical tube of matrix was studied with the help of a finite element model. A fracture mechanics approach

E. Martin; P. W. M. Peters; D. Leguillon; J. M. Quenisset

1998-01-01

159

Effect of Matrix Cracks on Damping in Unidirectional and Cross-Ply Ceramic Matrix Composites  

Microsoft Academic Search

The paper elucidates the methodsof estimating damping in ceramic matrix composites (CMC) with matrix cracks. Unidirectional composites with bridging matrix cracks and cross-ply laminates with tunneling cracks in transverse layers and bridging cracks in longitudinal layers are considered. It is shown that bridging matrix cracksdra matically increase damping in unidirectional CMC due to a dissipation of energy along damaged sections

Victor Birman; Larry W. Byrd

2002-01-01

160

Glycosaminoglycans content of stone matrix.  

PubMed

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

Roberts, S D; Resnick, M I

1986-05-01

161

USp(2k) Matrix Model  

NASA Astrophysics Data System (ADS)

We review the construction and theoretical implications of the USp(2k) matrix model in zero dimension introduced in Refs.~1) and 2). It is argued that the model provides a constructive approach to type I superstrings and is at the same time dynamical theory of spacetime points. Three subjects are discussed: semiclassical pictures and series of degenerate perturbative vacua associated with the worldvolume representation of the model, the formation of extended (D-) objects from the fermionic integrations via the (non-)abelian Berry phase, and the Schwinger-Dyson/loop equations which exhibit the joining-splitting interactions required.

Itoyama, H.; Tsuchiya, A.

162

Ideals of generalized matrix rings  

SciTech Connect

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

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

2011-01-31

163

Physical controls on matrix mineralization  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

164

Matrix metalloproteinases in metabolic syndrome.  

PubMed

Metabolic syndrome is commonly accompanied by an elevated cardiovascular risk with high morbidity and mortality. The alterations of the arterial vasculature begin with endothelial dysfunction and lead to micro- and macrovascular complications. The remodeling of the endothelial basal membrane, that promotes erosion and thrombosis, has a multifactorial pathogenesis that includes leukocyte activation, increased oxidative stress and also an altered matrix metalloproteinases (MMPs) expression. MMPs are endopeptidases which degrade extracellular matrix proteins, such as collagen, gelatins, fibronectin and laminin. They can be secreted by several cells within the vascular wall, but macrophages are determinant in the atherosclerotic plaques. Their activity is regulated by tissue inhibitors of MMP (TIMPs) and also by other molecules, such as plasmin. MMPs could be implicated in plaque instability predisposing to vascular complications. It has been demonstrated that an impaired MMP or TIMP expression is associated with higher risk of all-cause mortality. A large number of studies evaluated MMPs pattern in obesity, diabetes mellitus, arterial hypertension and dyslipidemia, all of which define metabolic syndrome according to several Consensus Statement (i.e. IDF, ATP III, AHA). However, few research have been carried out on subjects with metabolic syndrome. The evidences of an improvement in MMP/TIMP ratio with diet, exercise and medical therapy should encourage further investigations with the intent to contrast the atherosclerotic process and to reduce morbidity and mortality of this kind of patients. PMID:22284236

Hopps, E; Caimi, G

2011-10-13

165

Solid-matrix luminescence analysis  

SciTech Connect

Several interactions with lumiphors adsorbed on filter paper were elucidated from experiments with moisture, modulus and heavy-atom salts. The data were interpreted using static and dynamic quenching models, heavy-atom theory, and a theory related to the modulus of paper. With cyclodextrin-salt matrices, it was shown that 10% [alpha]-cyclodextrin/NaCl was very effective for obtaining strong room-temperature fluorescence and moderate room-temperature phosphorescence from adsorbed stereoisomeric tetrols. Extensive photophysical information was obtained for the four tetrols on 10% [alpha]-cyclodextrin/NaCl. The photophysical information acquired was used to develop a method for characterizing two of the tetrols. Work with model compounds adsorbed on deuterated sodium acetate showed that C-H vibrations in the undeuterated sodium acetate were not responsible for the deactivation of the excited triplet state in the model phosphors investigated. A considerable amount of solution luminescence and solid-matrix luminescence data were compared. The most important finding was that in several cases the room-temperature solid-matrix luminescence quantum yields were greater than the solution low-temperature quantum yield values.

Hurtubise, R.J.

1993-01-15

166

Light-cone matrix product  

SciTech Connect

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

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

2009-09-15

167

Applications of matrix inversion tomosynthesis  

NASA Astrophysics Data System (ADS)

The improved image quality and characteristics of new flat- panel x-ray detectors have renewed interest in advanced algorithms such as tomosynthesis. Digital tomosynthesis is a method of acquiring and reconstructing a three-dimensional data set with limited-angle tube movement. Historically, conventional tomosynthesis reconstruction has suffered contamination of the planes of interest by blurred out-of- plane structures. This paper focuses on a Matrix Inversion Tomosynthesis (MITS) algorithm to remove unwanted blur from adjacent planes. The algorithm uses a set of coupled equations to solve for the blurring function in each reconstructed plane. This paper demonstrates the use of the MITS algorithm in three imaging applications: small animal microscopy, chest radiography, and orthopedics. The results of the MITS reconstruction process demonstrate an improved reduction of blur from out-of-plane structures when compared to conventional tomosynthesis. We conclude that the MITS algorithm holds potential in a variety of applications to improve three-dimensional image reconstruction.

Warp, Richard J.; Godfrey, Devon J.; Dobbins, James T.

2000-04-01

168

Extracellular Matrix Regulation of Autophagy  

PubMed Central

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

Lock, Rebecca; Debnath, Jayanta

2008-01-01

169

Crosslinked Matrix-free Nanocomposites  

NASA Astrophysics Data System (ADS)

Matrix-free polymer-silica nanocomposites are formed by crosslinking polymer coated nanoparticles via the `click' reaction. The `click' reaction is also known as H"uisgen 1, 3-dipolar cycloaddition of terminal alkyne and azide functional groups to give 1, 2, 3-triazoles. Silica nanoparticles are functionalized with alkyne and azide moieties. Heterobifunctional ?,?-trimethylsilane-alkyne,azide-poly(styrene) (TMS-PS-N3) and ?,?-trimethylsilane-alkyne,azide--poly(tert-butyl acrylate) (TMS-PtBA-N3) are then covalently bound to the surfaces of the nanoparticles via the `click' reaction. The bare and modified nanoparticles are analyzed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The thermal, morphological, and mechanical properties of the systems are investigated by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and dynamic rheology, respectively. .

Dach, Benjamin; Rengifo, Hernan; Turro, Nicholas; Koberstein, Jeffrey

2010-03-01

170

Treatment of COPD: a matrix perspective.  

PubMed

Fundamental physical properties, such as the intrinsic recoil of the lung, are governed by the extracellular matrix. The prototypical roles of the matrix proteins, collagen and elastin, in pulmonary fibrosis and emphysema have long been recognized, and much research effort has been devoted to understanding mechanisms of extracellular matrix synthesis and turnover in the lung. Yet, despite extensive knowledge of the biochemical properties of collagen and elastin, none of the present clinical strategies for treating COPD directly target the extracellular matrix. From a matrix perspective, therapeutic interventions that limit elastic fiber destruction and/or restore function to damaged alveolar units merit particular consideration as clinical strategies for treating the emphysema component of COPD. Effective treatment of the bronchiolar component of COPD requires a better understanding of the relationship between airway fibrosis and airflow obstruction. Translating basic knowledge of extracellular matrix biology into the clinical venue will be essential in the development of new approaches to COPD treatment. PMID:18488434

Dunsmore, Sarah E

2008-01-01

171

Treatment of COPD: A matrix perspective  

PubMed Central

Fundamental physical properties, such as the intrinsic recoil of the lung, are governed by the extracellular matrix. The prototypical roles of the matrix proteins, collagen and elastin, in pulmonary fibrosis and emphysema have long been recognized, and much research effort has been devoted to understanding mechanisms of extracellular matrix synthesis and turnover in the lung. Yet, despite extensive knowledge of the biochemical properties of collagen and elastin, none of the present clinical strategies for treating COPD directly target the extracellular matrix. From a matrix perspective, therapeutic interventions that limit elastic fiber destruction and/or restore function to damaged alveolar units merit particular consideration as clinical strategies for treating the emphysema component of COPD. Effective treatment of the bronchiolar component of COPD requires a better understanding of the relationship between airway fibrosis and airflow obstruction. Translating basic knowledge of extracellular matrix biology into the clinical venue will be essential in the development of new approaches to COPD treatment.

Dunsmore, Sarah E

2008-01-01

172

Recursiveness in Matrix Rational Interpolation Problems  

Microsoft Academic Search

We consider the problem of computing solutions to a variety of matrix rational interpolationproblems. These include the partial realization problem for matrix power series andNewton-Pad'e, Hermite-Pad'e, Simultaneous Pad'e, M-Pad'e and multipoint Pad'e approximationproblems along with their matrix generalizations. A general recurrence relation is givenfor solving these problems. Unlike other previous recursive methods, our recurrence worksalong arbitrary computational paths. When...

Bernhard Beckermann; George Labahn

1996-01-01

173

Recursiveness in matrix rational interpolation problems  

Microsoft Academic Search

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

Bernhard Beckermann; George Labahn

1997-01-01

174

Extracellular Matrix: Functions in the Nervous System  

PubMed Central

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

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

2011-01-01

175

A matrix model black hole: act II  

NASA Astrophysics Data System (ADS)

In this paper we discuss the connection between the deformed matrix model and two dimensional black holes in the light of the new developements involving fermionic type 0A-string theory. We argue that many of the old results can be carried over to this new setting and that the original claims about the deformed matrix model are essentially correct. We show the agreement between correlation functions calculated using continuum and matrix model techniques. We also explain how detailed properties of the space time metric of the extremal blck hole of type 0A are reflected in the deformed matrix model.

Danielsson, Ulf H.

2004-02-01

176

Third Intermetallic Matrix Composites Symposium, volume 350  

SciTech Connect

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.

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

1994-04-01

177

Finding Nonoverlapping Substructures of a Sparse Matrix  

SciTech Connect

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

Pinar, Ali; Vassilevska, Virginia

2005-08-11

178

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

SciTech Connect

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.

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

1997-12-01

179

Relativistic R-matrix theory  

NASA Astrophysics Data System (ADS)

We have developed a relativistic coupled-channel reaction theory in which binary break-up channels satisfy a relative Dirac equation. This theory is developed by extending the R-matrix formalism of Lane and Thomas to the relativistic case and implementing the Dirac oscillator basis. The motivation for this project is testing potentials for the dense matter calculations and generating relativistic wave functions for the final states in the knockout reactions. As an example of the formalism we have calculated observables for the proton scattering on light-to-medium weight nuclei in the relativistic impulse approximation using the relativistic Love-Franey amplitudes of Horowitz. The R-matrix procedure allows the nonlocal exchange terms to be calculated exactly and compared with the local density approximation. These calculations demonstrate that the local density approximation is not suitable due to the relativistic effects. Thus the wave functions with exact exchange would be preferred in distorted wave calculations. Also, calculations involving pseudoscalar pi-N coupling provide a better agreement with experimental data than previously determined. In order to investigate relativistic effects in the bound states and scattering reactions, we have applied the theory to the quantum hadrodynamics (QHD) in the continuum Tamm-Dancoff approximation with the classical meson fields replaced by one-meson exchange potentials. The results show that the published QHD parameters do not provide a decent fit to the 15N+ p elastic cross section or reproduce the QHD single-particle energies, and hence, are not appropriate for structure calculations. We have found more suitable parameters by fitting meson coupling constants and masses to produce single-particle energies and employed them in the structure calculations for 16O. The results showed that the fitted single-particle energies have too large spin-orbit splitting. Our conclusion is that pi, sigma, o and rho meson exchange is inadequate for relativistic structure and reaction calculations. Unlike the conclusions of previous authors, the calculations indicate that the pseudoscalar pi-N coupling gives better agreement to experimental data than the pseudovector pi-N coupling. In addition, we calculated inelastic electron scattering form factors for the Dirac spinors and for the upper components of the Dirac spinors. The calculations indicated significant relativistic effects.

Grineviciute, Janina

180

Strain and hysteresis by stochastic matrix cracking in ceramic matrix composites  

Microsoft Academic Search

A theory is presented to predict the stress\\/strain relations and unload\\/reload hysteresis behavior during the evolution of multiple matrix cracking in unidirectional fiber reinforced ceramic matrix composites (CMCs). The theory is based on the similarity between multiple matrix cracking and fiber fragmentation in a single fiber composite, and determines the crack and strain evolution as a function of the statistical

B. K. Ahn; W. A. Curtin

1997-01-01

181

The design of the fibre-matrix interfacial zone in ceramic matrix composites  

Microsoft Academic Search

Ceramic matrix composites are tough when the fibre-matrix bonding is properly controlled during processing, via the use of an interphase. The interphase is either formed in situ as the result of fibre-matrix interactions or deposited on the fibre surface prior to composite fabrication. It has several key functions, including crack deflection, load transfer, diffusion barrier and residual stress relaxation. Four

Roger R. Naslain

1998-01-01

182

Extracellular Matrix Abnormalities in Schizophrenia  

PubMed Central

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

Berretta, Sabina

2011-01-01

183

Matrix Metalloproteinases and Angiogenic Factors  

PubMed Central

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

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

2010-01-01

184

Micromechanics of the pericellular matrix  

NASA Astrophysics Data System (ADS)

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

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

2006-03-01

185

The Molecules of the Cell Matrix.  

ERIC Educational Resources Information Center

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

Weber, Klaus; Osborn, Mary

1985-01-01

186

Weak matrix elements for CP violation.  

SciTech Connect

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

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

2001-01-01

187

Generalized matrix tree theorem for mixed graphs  

Microsoft Academic Search

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

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

1999-01-01

188

Juxtaposed Integration Matrix: A Crisis Communication Tool.  

National Technical Information Service (NTIS)

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

J. H. Cunningham

2005-01-01

189

Matrix models, geometric engineering and elliptic genera  

Microsoft Academic Search

We compute the prepotential of Script N = 2 supersymmetric gauge theories in four dimensions obtained by toroidal compactifications of gauge theories from 6 dimensions, as a function of Kähler and complex moduli of T2. We use three different methods to obtain this: matrix models, geometric engineering and instanton calculus. Matrix model approach involves summing up planar diagrams of an

Timothy J. Hollowood; Amer Iqbal; Cumrun Vafa

2008-01-01

190

The university of Florida sparse matrix collection  

Microsoft Academic Search

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

Timothy A. Davis; Yifan Hu

2011-01-01

191

Machining of particulate metal matrix composites  

Microsoft Academic Search

Particulate metal matrix composites (PMMCs) are being widely used in the aerospace and automotive industry due to their favourable properties, mainly high specific strength and wear resistance. However, machining of particulate metal matrix composites presents a great challenge to the industry as the reinforcing particles easily abrade most of the common cutting tool materials. Polycrystalline diamond (PCD) tools appear to

Mariam S El-Gallab

1999-01-01

192

Matrix model description of baryonic deformations  

SciTech Connect

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

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

2003-03-13

193

Multimedia Matrix: A Cognitive Strategy for Designers.  

ERIC Educational Resources Information Center

This instructional development project evaluates the effect of a matrix-based strategy to assist multimedia authors in acquiring and applying principles for effective multimedia design. The Multimedia Matrix, based on the Park and Hannafin "Twenty Principles and Implications for Interactive Multimedia" design, displays a condensed version of those…

Sherry, Annette C.

194

Oscillation Criteria for Nonlinear Matrix Differential Inequalities.  

National Technical Information Service (NTIS)

Let L be the matrix differential operator defined by LV = (A(X)V')' + B(x,V,V')V, where A,B, and V are m-square matrix functions, A(X) is symmetric, positive semidefinite, and continuous on an interval from A to, but not including, infinity, and B(x,V,V')...

C. A. Swanson

1969-01-01

195

Daubechies-Based Wavelet Differentiation Matrix.  

National Technical Information Service (NTIS)

The differentiation matrix for a Daubechies-based wavelet basis is constructed and superconvergence is proven. That is, it will be proven that under the assumption of periodic boundary conditions that the differentiation matrix is accurate of order 2M, ev...

L. Jameson

1993-01-01

196

Solidification phenomena in metal matrix nanocomposites  

Microsoft Academic Search

Nanoparticles in metal matrix nanocomposites (MMNCs) were shown to act as catalysts for nucleation of solidification of the matrix alloy, as well as to alter the intermetallic phase formation. These phenomena were studied in zinc, aluminum, and magnesium alloys. In all alloys studied, a refinement of the microstructure was seen with the addition of the nanoparticles. Various types of nanoparticles

Michael Peter de Cicco

2009-01-01

197

Optimal unbiased filtering via linear matrix inequalities  

Microsoft Academic Search

Solutions to the optimal H? and L2?L? unbiased reduced-order filtering problems are obtained in terms of linear matrix inequalities (LMIs). The order of the optimal filter is equal to the number of measurements. Both continuous- and discrete-time results are presented. An explicit parametrization of all optimal unbiased filters is provided in terms of a free contractive matrix.

Karolos M. Grigoriadis

1998-01-01

198

Matrix Algebra, Computers and Secret Coding.  

ERIC Educational Resources Information Center

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

Meyer, Ruth A.; Riley, James E.

1989-01-01

199

Introduction to Matrix Sampling for the Practitioner.  

ERIC Educational Resources Information Center

|One solution to the problem of obtaining test scores in order to assess multiple outcomes of educational programs is a basically simple technique called matrix sampling. Matrix sampling is the estimation of total test score statistics by administering random subsets of test items to randomly selected students. This chapter lays out the specific…

Sirotnik, Kenneth A.

200

A new generalized direct matrix converter  

Microsoft Academic Search

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

S. H. Hosseini; E. Babaei

2001-01-01

201

Reduced-density-matrix cumulants and correlation  

SciTech Connect

Spin components for the Grassmann product of the one-electron reduced density matrix with itself are compared with those of the two-electron reduced density matrix for the same state. It is found that the Grassmann product introduces some inappropriate behaviors which must be removed by the cumulant but are not what is usually thought of as correlation.

Harriman, John E. [Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2007-03-15

202

Proceedings of intermetallic matrix composites II  

SciTech Connect

This book contains the proceedings of Intermetallic Matrix Composites II. Topics covered include: intermetallic composites; integration of the Ti aluminide metal matrix composite; limitations of the fiber pushout test; quantitative test techniques; intermetallic eutectics; physical vapor deposition; deformation processing; melt infiltration; solid state displacement, niobium base alloys; and molybdenum alloys.

Miracle, D.B. (Air Force Wright Aeronautical Labs., Wright-Patterson AFB, OH (United States)); Anton, D.L. (United Technologies Research Center, East Hartford, CT (United States)); Graves, J.A. (Rockwell International Corp., Thousand Oaks, CA (United States). Science Center)

1992-01-01

203

Control system synthesis via bilinear matrix inequalities  

Microsoft Academic Search

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

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

1994-01-01

204

Creep rupture of polymer-matrix composites  

Microsoft Academic Search

An accelerated characterization method for resin-matrix composites is reviewed. Methods for determining modulus and strength master curves are given. Creep-rupture analytical models are discussed as applied to polymers and polymer-matrix composites. Comparisons between creep-rupture experiments and analytical models are presented.

H. F. Brinson; W. I. Griffith; D. H. Morris

1981-01-01

205

Reduced Transfer Matrix Approach for Ising Model  

Microsoft Academic Search

In this work, we present a simple approximate transfer matrix method for 2D and 3D Ising ferromagnet to calculate spontaneous magnetization of the system. The critical coupling strength Kc of 2D and 3D Ising models in reduced transfer matrix approximation is obtained quite accurately by simple improvements over the mean field theory. The important physical effect we include is the

Tuncer Kaya; Murat Arik

2011-01-01

206

Secret Sharing System and Secret Sharing Matrix  

Microsoft Academic Search

To make the secret sharing management more effective and safe, based on the (k, n) threshold secret sharing scheme, this article propose a new concept of generalized (k, n)-secret sharing matrix, and proposed a more safe (t, k, n) threshold secret sharing scheme by generalizing the (t, k, n) threshold secret sharing matrix. This article gave the concept of the

Guangliang Liu; Lingyun Li; Shengxian Xie; Junqing Li

2009-01-01

207

COMMUNITY MATRIX IN THREE SPECIES COMMUNITY MODELS  

EPA Science Inventory

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

208

A liquidic matrix-addressed display  

Microsoft Academic Search

Experiments with fluid logic circuits operated in an air-dyed water mode have demonstrated the basic validity of a large area, flat panel, matrix-addressed liquidic display. Such a display is conceptually attractive, since the switching, storage, and display functions are performed by the same medium. The measurements made have demonstrated that a reflective or emissive liquidic display, matrix addressed \\

GEORGE W. TAYLOR

1973-01-01

209

Fast matrix multiplies using graphics hardware  

Microsoft Academic Search

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

E. Scott Larsen; David K. McAllister

2001-01-01

210

A matrix analysis of conjugate gradient algorithms  

SciTech Connect

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).

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

1993-04-01

211

Robust alternative minimization for matrix completion.  

PubMed

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

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

2012-02-15

212

Fiber-matrix interfaces in ceramic composites  

SciTech Connect

The mechanical properties of ceramic matrix composites (CMCs) are governed by the relationships between the matrix, the interface material, and the fibers. In non-oxide matrix systems compliant pyrolytic carbon and BN have been demonstrated to be effective interface materials, allowing for absorption of mismatch stresses between fiber and matrix and offering a poorly bonded interface for crack deflection. The resulting materials have demonstrated remarkable strain/damage tolerance together with high strength. Carbon or BN, however, suffer from oxidative loss in many service environments, and thus there is a major search for oxidation resistant alternatives. This paper reviews the issues related to developing a stable and effective interface material for non-oxide matrix CMCs.

Besmann, T.M.; Stinton, D.P.; Kupp, E.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Shanmugham, S.; Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States). Materials Science and Engineering Dept.

1996-12-31

213

Refined matrix models from BPS counting  

SciTech Connect

We construct a free fermion and matrix model representation of refined Bogomol'nyi-Prasad-Sommerfeld generating functions of D2 and D0 branes bound to a single D6 brane, in a class of toric manifolds without compact four-cycles. In appropriate limit we obtain a matrix model representation of refined topological string amplitudes. We consider a few explicit examples which include a matrix model for the refined resolved conifold, or equivalently five-dimensional U(1) gauge theory, as well as a matrix representation of the refined MacMahon function. Matrix models which we construct have ordinary unitary measure, while their potentials are modified to incorporate the effect of the refinement.

Sulkowski, Piotr [California Institute of Technology, Pasadena, California 91125 (United States)

2011-04-15

214

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

215

2-Adic clustering of the PAM matrix.  

PubMed

In this paper we demonstrate that the use of the system of 2-adic numbers provides a new insight to some problems of genetics, in particular, degeneracy of the genetic code and the structure of the PAM matrix in bioinformatics. The 2-adic distance is an ultrametric and applications of ultrametric in bioinformatics are not surprising. However, by using the 2-adic numbers we match ultrametric with a number theoretic structure. In this way we find new applications of an ultrametric which differ from known up to now in bioinformatics. We obtain the following results. We show that the PAM matrix A allows the expansion into the sum of the two matrices A=A((2))+A((infinity)), where the matrix A((2)) is 2-adically regular (i.e. matrix elements of this matrix are close to locally constant with respect to the discussed earlier by the authors 2-adic parametrization of the genetic code), and the matrix A((infinity)) is sparse. We discuss the structure of the matrix A((infinity)) in relation to the side chain properties of the corresponding amino acids. We introduce the family of substitution matrices A(alpha,beta)=alpha A((2))+beta A((infinity)), alpha,beta>or=0 which should allow to vary the alignment procedure in order to take into account the different chemical and geometric properties of the amino acids. PMID:19699213

Khrennikov, A Yu; Kozyrev, S V

2009-08-20

216

Nuclear matrix proteins and hereditary diseases.  

PubMed

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

Sjakste, N; Sjakste, T

2005-03-01

217

Matrix Models Coupled to AN External Field.  

NASA Astrophysics Data System (ADS)

In recent years, there have been significant advances in the related fields of noncritical strings, two-dimensional quantum gravity, and random surfaces. Of particular importance has been the development of matrix models as a tool for calculating sums over surfaces, providing a convenient calculational alternative to Liouville theory, an independent check on results, and sometimes new physical insights. This thesis examines matrix models coupled to an external field. Chapter 1 is a review of the basics of matrix models and large N techniques. Chapter 2 introduces and motivates the concept of an external field. The discussion concentrates on two such models involving integration over unitary and hermitian matrices. The Schwinger-Dyson equations of motion are derived, followed by a review of the solution to leading order. Then a new procedure for calculating the 1/N expansion of the models is derived, which allows one to find the double scaling limits and calculate the critical exponents. The multicritical points of the models are analyzed and found to exhibit unusual genus dependence. The chapter concludes with an examination of the model of symmetric matrices, and a discussion of the differences between it and the hermitian matrix model. Chapter 3 contains a demonstration of how the external field method can be applied to find the solution to certain multimatrix models, including the matrix chain and the Potts models. The solution of the two-matrix (Ising) model agrees with that previously found by orthogonal polynomials. Chapter 4 introduces the Kontsevich model and topological gravity. After a review of the role of Virasoro constraints in the one-matrix model, the constraints are derived for the Kontsevich model from the Schwinger-Dyson equations of motion, thus demonstrating equivalence between the one matrix model and topological gravity. The thesis concludes with the analysis of an analog of the Kontsevich model involving unitary matrices, and the derivation of the Virasoro constraints of the multicritical unitary matrix models.

Newman, Michael Jack

218

Sensitivity coefficients for matrix-based LCA  

Microsoft Academic Search

Background, aim, and scope  Matrix-based life cycle assessment (LCA) is part of the standard ingredients of modern LCA tools. An important aspect of matrix-based\\u000a LCA that is straightforward to carry out, but that requires a careful mathematical handling, is the inclusion of sensitivity\\u000a coefficients based on differentiating the matrix-based formulas.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  We briefly review the basic equations for LCA and

Reinout Heijungs

2010-01-01

219

Matrix-enhanced cluster-SIMS  

NASA Astrophysics Data System (ADS)

We have used 23 keV C60+ projectiles in the event-by-event bombardment and detection mode to investigate the emission of the gramicidin S [M - H]- ion embedded in a matrix of sinapic acid. We have observed an increase in the gramicidin S [M - H]- ion of approximately eight times by controlling the ratio of gramicidin S to sinapic acid. The maximum of the gramicidin S [M - H]- yield occurs at a matrix/analyte ratio of 10:1. This ratio is different from those typically used in matrix-assisted laser desorption/ionization.

Locklear, J. E.; Guillermier, C.; Verkhoturov, S. V.; Schweikert, E. A.

2006-07-01

220

Extracellular matrix signaling in morphogenesis and repair.  

PubMed

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

Clause, Kelly C; Barker, Thomas H

2013-05-28

221

A transilient matrix for moist convection  

SciTech Connect

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

Romps, D.; Kuang, Z.

2011-08-15

222

Explicitly Correlated Gaussian Basis Functions: Derivation and Implementation of Matrix Elements and Gradient Formulas Using Matrix Differential Calculus  

Microsoft Academic Search

The matrix differential calculus is introduced to the quantum chemistry community via new matrix derivations of integral formulas and gradients for Hamiltonian matrix elements in a basis of correlated Gaussian functions. Requisite mathematical background material on Kronecker products, Hadamard products, the vec and vech operators, linear structures, and matrix differential calculus is presented. New matrix forms for the kinetic and

Donald Bruce Kinghorn

1995-01-01

223

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

PubMed Central

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

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

2013-01-01

224

Interlaminar Fracture Toughness in Resin Matrix Composites.  

National Technical Information Service (NTIS)

This annual report summarizes the objectives, accomplishments and proposed new directions of research on mode II interlaminar fracture in resin matrix composites. A mode II interlaminar fracture specimen, test and analysis method for interpreting results ...

L. W. Rehfield E. A. Armanios A. D. Reddy

1984-01-01

225

Scattering Matrix Synthesis Using Multiport Cavities.  

National Technical Information Service (NTIS)

The necessary and sufficient conditions are established on the scattering matrix for an n-port to be realizable as a cascade of multiport cavities having proportional ports coupled through circulators. Design equations, yielding cavity dimensions, are giv...

K. A. Zaki R. W. Newcomb

1973-01-01

226

Properties of Five Toughened Matrix Composite Materials.  

National Technical Information Service (NTIS)

The use of toughened matrix composite materials offers an attractive solution to the problem of poor damage tolerance associated with advanced composite materials. In this study, the unidirectional laminate strengths and moduli, notched (open-hole) and un...

R. J. Cano M. B. Dow

1992-01-01

227

Sensitivity analysis of periodic matrix population models.  

PubMed

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

Caswell, Hal; Shyu, Esther

2012-12-01

228

Integrated optic vector-matrix multiplier  

SciTech Connect

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

Watts, Michael R. (Albuquerque, NM)

2011-09-27

229

H -matrix theory vs. eigenvalue localization  

NASA Astrophysics Data System (ADS)

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

Cvetkovic, Ljiljana

2006-07-01

230

Matrix models of 2d gravity  

NASA Astrophysics Data System (ADS)

These are introductory lectures for a general audience that give an overview of the subject of matrix models and their application to random surfaces, 2d gravity, and string theory. They are intentionally 1.5 years out of date.

Ginsparg, P.

231

Superfund Chemical Data Matrix. Appendix B Tables.  

National Technical Information Service (NTIS)

The Superfund Chemical Data Matrix (SCDM) Appendix B Tables are a source for factor values and benchmark values applied when evaluating potential National Priority List (NPL) sites using the Hazard Ranking System (HRS). The HRS assigns factor values for t...

1994-01-01

232

Transfer Matrix Synthesis Using Active RC Networks.  

National Technical Information Service (NTIS)

Necessary conditions are established for the voltage transfer matrix of a transformerless grounded network composed of ideal resistors, inductors, capacitors (RLC), and grounded unity gain amplifiers. These conditions are also shown to be sufficient for r...

D. Hazony R. D. Joseph

1965-01-01

233

Axial grading of inert matrix fuels  

SciTech Connect

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)

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

2012-07-01

234

Matrix models of 2d gravity  

Microsoft Academic Search

These are introductory lectures for a general audience that give an overview of the subject of matrix models and their application to random surfaces, 2d gravity, and string theory. They are intentionally 1.5 years out of date.

P. Ginsparg

1991-01-01

235

ZZ brane amplitudes from matrix models  

NASA Astrophysics Data System (ADS)

We study instanton contribution to the partition function of the one matrix model in the k-th multicritical region, which corresponds to the (2,2k-1) minimal model coupled to Liouville theory. The instantons in the one matrix model are given by local extrema of the effective potential for a matrix eigenvalue and identified with the ZZ branes in Liouville theory. We show that the 2-instanton contribution in the partition function is universal as well as the 1-instanton contribution and that the connected part of the 2-instanton contribution reproduces the annulus amplitudes between the ZZ branes in Liouville theory. Our result serves as another nontrivial check on the correspondence between the instantons in the one matrix model and the ZZ branes in Liouville theory, and also suggests that the expansion of the partition function in terms of the instanton numbers are universal and gives systematically ZZ brane amplitudes in Liouville theory.

Sato, Akira; Tsuchiya, Asato

2005-02-01

236

Measuring strangeness matrix elements of the nucleon  

SciTech Connect

Experiments are proposed to measure various strangeness matrix elements of the nucleon. Examples are electro- and neutrino- production of phi mesons and the difference between neutrino and antineutrino scattering from isospin zero targets, e.g., deuterons.

Henley, E.M.; Pollock, S.J. [Washington Univ., Seattle, WA (United States); Krein, G. [Washington Univ., Seattle, WA (United States)]|[Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Williams, A.G. [Washington Univ., Seattle, WA (United States)]|[Florida State Univ., Tallahassee, FL (United States)

1991-12-31

237

Measuring strangeness matrix elements of the nucleon  

SciTech Connect

Experiments are proposed to measure various strangeness matrix elements of the nucleon. Examples are electro- and neutrino- production of phi mesons and the difference between neutrino and antineutrino scattering from isospin zero targets, e.g., deuterons.

Henley, E.M.; Pollock, S.J. (Washington Univ., Seattle, WA (United States)); Krein, G. (Washington Univ., Seattle, WA (United States) Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)); Williams, A.G. (Washington Univ., Seattle, WA (United States) Florida State Univ., Tallahassee, FL (United States))

1991-01-01

238

Matrix rank in variational nodal approximations  

Microsoft Academic Search

Diffusion and transport variational nodal methods are being used increasingly for two and three-dimensinal fast reactor calculations in both Cartesian and hexagonal geometries. This report is concerned with matrix rank in variational nodal approximations.

C. B. Carrico; G. Palmoitti; E. E. Lewis

1994-01-01

239

Planar Liquid Crystal Matrix Array Chip.  

National Technical Information Service (NTIS)

This document describes a process for forming planar liquid crystal matrix array chips. The process includes the steps of electro-plating a conductive material over a smoothing layer thereby filling the contact holes with conductive material or alternativ...

M. N. Ernstorr

1978-01-01

240

Matrix Factorization Techniques for Recommender Systems  

Microsoft Academic Search

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

Yehuda Koren; Robert M. Bell; Chris Volinsky

2009-01-01

241

Nonequilibrium Chemistry Boundary Layer Integral Matrix Procedure.  

National Technical Information Service (NTIS)

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

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

1973-01-01

242

Nuclear waste storage container with metal matrix  

DOEpatents

The invention relates to a storage container for high-level waste having a metal matrix for the high-level waste, thereby providing greater impact strength for the waste container and increasing heat transfer properties.

Sump, Kenneth R. (Kennewick, WA)

1978-01-01

243

Corrosion Behavior of Metal Matrix Composites.  

National Technical Information Service (NTIS)

A research program was conducted to assess the corrosion behavior of two categories of copper metal matrix composites; commercially available composites and composites in development. The commercially available composite studied was dispersion strengthene...

H. G. Wheat

1993-01-01

244

Plasma Joining of Metal Matrix Composites.  

National Technical Information Service (NTIS)

The project was an analytical and experimental investigation of low pressure, transferred arc plasma joining of discontinuously reinforced metal matrix composites using composite powder filler metals. Modeling of the expected effects of plasma processing ...

G. H. Reynolds L. Yang

1988-01-01

245

48 CFR 1652.370 - Use of the matrix.  

Code of Federal Regulations, 2012 CFR

...FORMS CONTRACT CLAUSES FEHBP Clause Matrix 1652.370 Use of the matrix. (a) The matrix in this section lists the FAR and FEHBAR clauses to be used with contracts based on cost analysis and contracts based on a combination...

2012-10-01

246

Polarimetric Covariance Matrix Analysis of Random Radar Targets.  

National Technical Information Service (NTIS)

Two equivalent approaches for the description of mean polarimetric backscattering features for random radar targets exist, the so-called Mueller matrix and the covariance matrix approach. The covariance matrix contains measurable radar observables and is ...

E. Lueneburg V. Ziegler A. Schroth K. Tragl

1991-01-01

247

Notched strength of ceramic-matrix composites  

Microsoft Academic Search

Two simple approaches for characterizing the strength of notched ceramic-matrix composites are presented in non-dimensional form for finite geometries and are used to evaluate the notched strength of a woven-Nicalon-reinforced ceramic-matrix composite. Notch sensitivity can be evaluated with one parameter—the material toughness divided by the product of the unnotched strength and specimen width. For notchinsensitive behavior, a minimum toughness can

W. P. Keith; K. T. Kedward

1997-01-01

248

Matrix formulation of co-kriging  

Microsoft Academic Search

The matrix form of the general co-kriging problem is presented. Matrix solutions are given for SRFs with covariance functions, for IRFs of order zero using variograms and for universal co-kriging. General methods for obtaining cross-covariance or cross-variogram models are given. The relationship of the general co-kriging problem to the problem of one under sampled variable is presented.

Donald E. Myers

1982-01-01

249

Email Surveillance Using Nonnegative Matrix Factorization  

Microsoft Academic Search

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

Michael W. Berry; Murray Browne

2005-01-01

250

Plant Cell Wall Matrix Polysaccharide Biosynthesis  

Microsoft Academic Search

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

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

251

Transfer matrix method for linear multibody system  

Microsoft Academic Search

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

Xiaoting Rui; Guoping Wang; Yuqi Lu; Laifeng Yun

2008-01-01

252

Near commuting multi-matrix models  

NASA Astrophysics Data System (ADS)

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

O'Connor, Denjoe; Filev, Veselin G.

2013-04-01

253

Design of a RF NEMS switch matrix  

Microsoft Academic Search

This paper presents for the first time, the development of a monolithic RF NEMS switch matrix. A prototype 3×3 monolithic switch matrix is designed and simulated at the nano-scale level using Ansoft HFSS and Agilent ADS. Simulation results show that the proposed NEMS switch matrices are capable of working up to 60GHz with good RF performance such as return loss

Eugene Siew; King Yuk Chan; Rodica Ramer; Andrew Dzurak

2011-01-01

254

Nanophosphor composite scintillator with a liquid matrix  

DOEpatents

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

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

2010-03-16

255

Thermal expansion behavior of silver matrix composites  

Microsoft Academic Search

Silver matrix composites containing 10 to 40 vol pct ceramic reinforcements of different types, shapes, and sizes were processed\\u000a by electroless silver plating and hot pressing. The thermal expansion behavior of the silver matrix composites has been studied\\u000a from room temperature to 300 C. The coefficients of thermal expansion (CTEs) of the composites are effectively lowered to\\u000a below 10 10?6\\/C

Shou-Yi Chang; Su-Jien Lin; Merton C. Flemings

2000-01-01

256

INDUSTRIALIZATION OF CAST ALUMINUM MATRIX COMPOSITES (AMCCs)  

Microsoft Academic Search

This paper briefly describes the main research points and activities which have been considered toward industrialization of cast aluminum matrix composites (AMCCs). First, the issues in liquid processing of metal matrix composites are reviewed. The different requirements for successful AMCCs are then described. Post-processingsuch as heat treatment, forming, and machining, which can beperformed on AMCCs, are discussed. The up-to-date, specially

Mohamed A. Taha

2001-01-01

257

Fuel cell with electrolyte matrix assembly  

DOEpatents

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

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

1988-01-01

258

The transfer matrix: A geometrical perspective  

Microsoft Academic Search

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

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

259

Matrix effects in plasma desorption mass spectrometry  

Microsoft Academic Search

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

Stephane Bouchonnet; Yannik Hoppilliard; Christine Mauriac

1993-01-01

260

Photogeneration of heptacene in a polymer matrix.  

PubMed

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

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

2006-08-01

261

Integrated optical architectures for matrix multiplication  

NASA Astrophysics Data System (ADS)

Optical systems are particularly adept at performing high speed multiplication and division, which are the operations required for matrix multiplication. Implementing these operations in an integrated optical circuit (IOC) has the additional advantage of compactness and manufacturability. In this paper it is shown how analog integrated optical components can be assembled to design compact IOCs for implementing both analog and digital algorithms for carrying out matrix multiplication.

Verber, C. M.

1985-02-01

262

Scattering-matrix approach to multilayer diffraction  

NASA Astrophysics Data System (ADS)

The scattering-matrix approach was applied and combined with the Chandezon et al. coordinate transformation method to yield a highly stable modeling system for a multilayer diffraction structure. The programs developed were evaluated by comparing them with the normal transfer-matrix method for thicknesses up to which the latter was stable. In addition, experimental data on optical excitation of surface plasmons and guided waves on dielectric coated metallized gratings were compared fully with this modeling approach. Excellent agreement was obtained.

Cotter, N. P. K.; Preist, T. W.; Sambles, J. R.

1995-05-01

263

Fabrication of metal matrix composites of  

Microsoft Academic Search

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

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

1992-01-01

264

CUR matrix decompositions for improved data analysis  

PubMed Central

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

Mahoney, Michael W.; Drineas, Petros

2009-01-01

265

Matrix method for acoustic levitation simulation.  

PubMed

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

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

2011-08-01

266

Molecular dynamics simulations of matrix assisted laser desorption ionization: Matrix-analyte interactions  

NASA Astrophysics Data System (ADS)

There is synergy between matrix assisted laser desorption ionization (MALDI) experiments and molecular dynamics (MD) simulations. To understand analyte ejection from the matrix, MD simulations have been employed. Prior calculations show that the ejected analyte molecules remain solvated by the matrix molecules in the ablated plume. In contrast, the experimental data show free analyte ions. The main idea of this work is that analyte molecule ejection may depend on the microscopic details of analyte interaction with the matrix. Intermolecular matrix-analyte interactions have been studied by focusing on 2,5-dihydroxybenzoic acid (DHB; matrix) and amino acids (AA; analyte) using Chemistry at HARvard Molecular Mechanics (CHARMM) force field. A series of AA molecules have been studied to analyze the DHB-AA interaction. A relative scale of AA molecule affinity towards DHB has been developed.

Nangia, Shivangi; Garrison, Barbara J.

2011-07-01

267

Biocompatibility evaluation of vessel extracellular matrix as a matrix for urethral reconstruction  

Microsoft Academic Search

The objective of this study was to evaluate the biocompatibility of vessel extracellular matrix (VECM) from rabbit and to\\u000a discuss the feasibility of vessel extracellular matrix as a matrix for urethral reconstruction. Primary cultured bladder smooth\\u000a muscle cells isolated from New Zealand rabbits were implanted on VECM.The effects of VECM on rabbit bladder smooth muscle\\u000a cells (RBSMCs) metabolic activity, attachment,

Fujin Shen; Sixing Yang; Yi Yao; Kaiyu Qian; Yun Wei; Linglong Wang

2007-01-01

268

Fiber-matrix interfacial characteristics in a fiber-reinforced ceramic matrix composite  

Microsoft Academic Search

Fiber-matrix interfacial shear stress and mechanical properties in oxide-matrix composites uniaxially reinforced with either uncoated or coated silicon carbide filaments were measured in the as-fabricated state, and following a thermal treatment at 1300 C for 100 h. All the tested composites showed higher fiber-matrix interfacial debond stress than the frictional stress, and toughened-composite behavior. Mechanical properties of composites reinforced with

Raj N. Singh

1989-01-01

269

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

Microsoft Academic Search

Experimental data associated with the development of matrix cracks in unidirectional continuous silicon carbide fiber\\/calcium alumino-silicate matrix laminates under quasi-static loading are presented, including crack density, residual strain and hysteresis behavior as functions of applied stress. Simple models are developed, based on an assumption of purely frictional load transfer between the fiber and matrix, which describe reasonably well the quasi-static

A. W. Pryce; P. A. Smith

1993-01-01

270

Mechanical behavior of woven ceramic matrix composites  

NASA Astrophysics Data System (ADS)

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

Kuhn, Jonathan L.

271

Shrinkage Estimation of the Realized Relationship Matrix  

PubMed Central

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

Endelman, Jeffrey B.; Jannink, Jean-Luc

2012-01-01

272

The developing enamel matrix: nature and function.  

PubMed

The hydroxyapatite crystals of mature enamel are unusually large, uniform and regularly disposed within the tissue, implying that their development is a highly controlled process. The organic matrix of developing enamel is presumed to play an important role in the modulation of mineral deposition and growth during tooth morphogenesis but the precise functions of individual matrix proteins remain unclear. The aim of this review was to survey the current knowledge of enamel matrix proteins with a view to suggesting possible functions. The organic matrix is highly heterogeneous, comprising proteins derived from a number of different genes, including amelogenin, enamelin, ameloblastin (amelin/sheathlin), tuftelin, dentine sialophosphoprotein, enzymes and serum proteins such as albumin. Each of these classes appears to undergo post-secretory sequential degradation which contributes further towards matrix heterogeneity. Possible functions of these proteins include de novo mineral nucleation/initiation (dentine sialophosphoprotein, tuftelin), mineral ion binding as crystal precursors (amelogenin, enamelin), control of crystal growth (amelogenin, enamelin, ameloblastin), support of growing crystals (amelogenin, enamelin), determination of prismatic structure (ameloblastin), cell signalling (tuftelin, ameloblastin), control of secretion (breakdown products) and protection of the mineral phase (amelogenin, enamelin). Failure of these mechanisms could lead to incomplete maturation of the enamel and the eruption of dysplastic tissue. PMID:9541238

Robinson, C; Brookes, S J; Shore, R C; Kirkham, J

1998-01-01

273

Effect of reinforcement morphology on matrix microcracking  

SciTech Connect

The authors quantitatively examine the conditions under which a particle matrix misfit leads to matrix crack growth as a function of inclusion shape. Such misfit stresses and cracks can be generated by thermal expansion mismatch, generated by cooling a brittle matrix containing ductile inclusions. Using fracture mechanics and perturbation theory, they analyze the case of a penny-shaped crack interacting with a misfitting spheroidal inclusion. A simple and direct relationship is established between the strain energy release rate and the physical and geometrical properties of the system including: the thermal expansion mismatch, temperature change, the crack and inclusion sizes, the elastic properties of the medium and the shape of the inclusion. In particular, the effects of inclusion shape on the stress intensity factors and strain energy release rate are analytically determined for nearly spherical inclusions. The authors use this information to determine the minimum crack size for crack growth to occur and the maximum size to which cracks may grown. The maximum crack size corresponds to the case where the elastic strain energy released upon crack growth is no longer sufficient to compensate for energy expended in extending the crack as the crack is growing into the rapidly decreasing stress field. The authors employ a nominally exact numerical procedure to study the effects of whiskers and platelets (i.e. spheroids very different from spheres) on matrix cracking. It is found that upon cooling a composite containing ductile inclusions, the propensity for matrix cracking is maximized for reinforcement shapes close to that of a sphere.

Sridhar, N.; Srolovitz, D.J. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering; Rickman, J.M. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Materials Science and Engineering

1996-03-01

274

Calculus of continuous matrix product states  

NASA Astrophysics Data System (ADS)

We discuss various properties of the variational class of continuous matrix product states, a class of Ansatz states for one-dimensional quantum fields that was recently introduced as the direct continuum limit of the highly successful class of matrix product states. We discuss both attributes of the physical states, e.g., by showing in detail how to compute expectation values, as well as properties intrinsic to the representation itself, such as the gauge freedom. We consider general translation noninvariant systems made of several particle species and derive certain regularity properties that need to be satisfied by the variational parameters. We also devote a section to the translation invariant setting in the thermodynamic limit and show how continuous matrix product states possess an intrinsic ultraviolet cutoff. Finally, we introduce a new set of states, which are tangent to the original set of continuous matrix product states. For the case of matrix product states, this construction has recently proven relevant in the development of new algorithms for studying time evolution and elementary excitations of quantum spin chains. We thus lay the foundation for similar developments for one-dimensional quantum fields.

Haegeman, Jutho; Cirac, J. Ignacio; Osborne, Tobias J.; Verstraete, Frank

2013-08-01

275

Matrix Metalloproteinase Control of Capillary Morphogenesis  

PubMed Central

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

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

2010-01-01

276

Spark plasma sintering of aluminum matrix composites  

NASA Astrophysics Data System (ADS)

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

Yadav, Vineet

277

Loop transfer matrix and loop quantum mechanics  

NASA Astrophysics Data System (ADS)

The gonihedric model of random surfaces on a 3d euclidean lattice has equivalent representation in terms of transfer matrix K(Qi,Qf) which describes the propagation of loops Q. We extend the previous construction of loop transfer matrix to the case of non-zero self-intersection coupling constant kappa. We introduce loop generalization of Fourier transformation which allows to diagonalize transfer matrices depending on symmetric difference of loops and express all eigenvalues of 3d loop transfer matrix through the correlation functions of the corresponding 2d statistical system. The loop Fourier transformation allows to carry out analogy with quantum mechanics of point particles, to introduce conjugate momentum loop P and to define loop quantum mechanics. We also consider transfer matrix on 4d lattice which describes propagation of memebranes. This transfer matrix can also be diagonalized by using generalized Fourier transformation, and all its eigenvalues are equal to the correlation functions of the corresponding 3d statistical system. Particularly the free energy of the 4d membrane system is equal to the free energy of 3d gonihedric system of loops.

Savvidy, George K.

2000-09-01

278

D-MATRIX: A web tool for constructing weight matrix of conserved DNA motifs  

PubMed Central

Despite considerable efforts to date, DNA motif prediction in whole genome remains a challenge for researchers. Currently the genome wide motif prediction tools required either direct pattern sequence (for single motif) or weight matrix (for multiple motifs). Although there are known motif pattern databases and tools for genome level prediction but no tool for weight matrix construction. Considering this, we developed a D-MATRIX tool which predicts the different types of weight matrix based on user defined aligned motif sequence set and motif width. For retrieval of known motif sequences user can access the commonly used databases such as TFD, RegulonDB, DBTBS, Transfac. D­MATRIX program uses a simple statistical approach for weight matrix construction, which can be converted into different file formats according to user requirement. It provides the possibility to identify the conserved motifs in the co­regulated genes or whole genome. As example, we successfully constructed the weight matrix of LexA transcription factor binding site with the help of known sos­box cis­regulatory elements in Deinococcus radiodurans genome. The algorithm is implemented in C-Sharp and wrapped in ASP.Net to maintain a user friendly web interface. D­MATRIX tool is accessible through the CIMAP domain network. Availability http://203.190.147.116/dmatrix/

Sen, Naresh; Mishra, Manoj; Khan, Feroz; Meena, Abha; Sharma, Ashok

2009-01-01

279

Interface Structure Matrix for Analysis of Products and Processes  

Microsoft Academic Search

The product life-cycle management has been considered from different perspectives, including the Design (or Dependency) Structure Matrix (DSM) approach. In this paper, a matrix decomposition approach is presented as an alternative to the DSM approach. The decomposition approach calls for another representation of the input data (a matrix) referred to in the literature as the Interface Structure Matrix (ISM). The

Andrew Kusiak

2008-01-01

280

A Hankel matrix approach to singular system realization theory  

Microsoft Academic Search

A Hankel matrix approach to singular system realization theory is presented. The focus is exclusively on discrete-time or descriptor systems. Based on definitions of reachability and observability, the notion of a system Hankel matrix is first defined. The system Hankel matrix is then shown to have reachability-observability matrix factorizations which can be used to solve the realization synthesis problem. The

W. Steven Gray; Erik I. Verriest; Frank L. Lewis

1990-01-01

281

Iodine-assisted matrix-assisted laser desorption\\/ionisation  

Microsoft Academic Search

Addition of iodine to the matrix has been found to lead to lower thresholds for ion formation in matrix-assisted laser desorption\\/ionisation (MALDI) of peptides and other compounds. Intensities of ions from the matrix have been suppressed through the addition of iodine to the matrix; intensities of ions corresponding to addition of sodium or potassium to the analyte have been diminished.

Sajid Bashir; William I Burkitt; Peter J Derrick; Anastassios E Giannakopulos

2002-01-01

282

The biofilm matrix – an immobilized but dynamic microbial environment  

Microsoft Academic Search

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

Ian W Sutherland

2001-01-01

283

Matrix metalloproteinases as modulators of inflammation and innate immunity  

Microsoft Academic Search

As their name implies, matrix metalloproteinases are thought to be responsible for the turnover and degradation of the extracellular matrix. However, matrix degradation is neither the sole nor the main function of these proteinases. Indeed, as we discuss here, recent findings indicate that matrix metalloproteinases act on pro-inflammatory cytokines, chemokines and other proteins to regulate varied aspects of inflammation and

Carole L. Wilson; Yolanda S. López-Boado; William C. Parks

2004-01-01

284

A transfer matrix approach to conductance in quantum waveguides  

Microsoft Academic Search

A transfer matrix approach is presented for the study of electron conduction in an arbitrarily shaped cavity structure embedded in a quantum wire. Using the boundary conditions for wave functions, the transfer matrix at an interface with a discontinuous potential boundary is obtained for the first time. The total transfer matrix is calculated by multiplication of the transfer matrix for

Wei-Dong Sheng; Jian-Bai Xia

1996-01-01

285

The transfer matrix: A geometrical perspective  

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

286

Renormalon ambiguities in NRQCD operator matrix elements  

SciTech Connect

We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of {ital S}-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass. {copyright} {ital 1999} {ital The American Physical Society}

Bodwin, G.T. [High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Chen, Y. [Physics Department, Ohio State University, Columbus, Ohio 43210 (United States)

1999-09-01

287

Renormalon ambiguities in NRQCD operator matrix elements  

NASA Astrophysics Data System (ADS)

We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of S-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass.

Bodwin, Geoffrey T.; Chen, Yu-Qi

1999-09-01

288

Statistical properties of random matrix product states  

SciTech Connect

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

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

2010-11-15

289

Evolutionary matrix games and optimization theory.  

PubMed

An evolutionarily stable strategy (ESS) is only required to be capable of resisting invasion by rare mutant strategies. In contrast, an absolute invader strategy (AIS) is a rare mutant strategy that can invade any established strategy. We show that the predictions of the outcome of evolution made by optimization models are compatible with those made by the classical expected payoff comparisons in matrix games. We also show that if a matrix game has an AIS that AIS is unique and is also an ESS. But an ESS need not be an AIS. In pure-strategy submodels, an AIS need not be unique. An AIS of a matrix game has global asymptotic stability property in the game dynamics which involve only pure strategies including the AIS. PMID:19056399

Apaloo, J

2008-11-08

290

Nanomechanics of the Cartilage Extracellular Matrix  

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

291

Matrix metalloproteinases in destructive pulmonary pathology  

PubMed Central

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

Elkington, P T G; Friedland, J S

2006-01-01

292

Matrix metalloproteinases in kidney homeostasis and diseases  

PubMed Central

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have been increasingly linked to both normal physiology and abnormal pathology in the kidney. Collectively able to degrade all components of the extracellular matrix, MMPs were originally thought to antagonize the development of fibrotic diseases solely through digestion of excessive matrix. However, increasing evidence has shown that MMPs play a wide variety of roles in regulating inflammation, epithelial-mesenchymal transition, cell proliferation, angiogenesis, and apoptosis. We now have robust evidence for MMP dysregulation in a multitude of renal diseases including acute kidney injury, diabetic nephropathy, glomerulonephritis, inherited kidney disease, and chronic allograft nephropathy. The goal of this review is to summarize current findings regarding the role of MMPs in kidney diseases as well as the mechanisms of action of this family of proteases.

Tan, Roderick J.

2012-01-01

293

Electrolyte matrix for molten carbonate fuel cells  

DOEpatents

A matrix is described for a carbonate electrolyte including a support material and an additive constituent having a relatively low melting temperature and a relatively high coefficient of thermal expansion. The additive constituent is from 3 to 45 weight percent of the matrix and is formed from raw particles whose diameter is in a range of 0.1 {micro}m to 20 {micro}m and whose aspect ratio is in a range of 1 to 50. High energy intensive milling is used to mix the support material and additive constituent during matrix formation. Also disclosed is the use of a further additive constituent comprising an alkaline earth containing material. The further additive is mixed with the support material using high energy intensive milling. 5 figs.

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

1999-02-09

294

Electrolyte matrix for molten carbonate fuel cells  

DOEpatents

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

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

1999-01-01

295

Introducing Matrix Operations through Biological Applications  

NSDL National Science Digital Library

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

Shiflet, Angela B.; Shiflet, George W.

296

HXeOBr in a xenon matrix  

SciTech Connect

We report on a new noble-gas molecule HXeOBr prepared in a low-temperature xenon matrix from the HBr and N{sub 2}O precursors by UV photolysis and thermal annealing. This molecule is assigned with the help of deuteration experiments and ab initio calculations including anharmonic methods. The H-Xe stretching frequency of HXeOBr is observed at 1634 cm{sup -1}, which is larger by 56 cm{sup -1} than the frequency of HXeOH identified previously. The experiments show a higher thermal stability of HXeOBr molecules in a xenon matrix compared to HXeOH.

Khriachtchev, Leonid; Tapio, Salla; Domanskaya, Alexandra V.; Raesaenen, Markku [Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 (Finland); Isokoski, Karoliina [Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Lundell, Jan [Department of Chemistry, University of Jyvaeskylae, P.O. Box 35, FIN-40014 Jyvaeskylae (Finland)

2011-03-28

297

Matrix element method and QCD radiation  

SciTech Connect

The matrix element method has been extensively used for the analysis of top-quark and W-boson physics at the Tevatron but in general without dedicated treatment of initial-state QCD radiation. At the LHC, the increased center-of-mass energy leads to a significant increase in the amount of QCD radiation, which makes it mandatory to carefully account for its effects. We here present several methods for inclusion of QCD radiation effects in the matrix element method and apply them to mass determination in the presence of multiple invisible particles in the final state. We demonstrate significantly improved results compared to the standard treatment.

Alwall, J. [Department of Physics and National Center for Theoretical Sciences, National Taiwan University, Taipei, 10617, Taiwan (China); Freitas, A. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara St, Pittsburgh, Pennsylvania 15260 (United States); Mattelaer, O. [Center for Cosmology, Particle Physics and Phenomenology (CP3), Universite Catholique de Louvain, Chemin du Cyclotron 2, 1348 Louvain-la-Neuve (Belgium)

2011-04-01

298

Some remarks on unilateral matrix equations  

SciTech Connect

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

Cerchiai, Bianca L.; Zumino, Bruno

2001-02-01

299

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.

2001-01-01

300

Little typeIIB matrix model  

NASA Astrophysics Data System (ADS)

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/r4, implying a six-dimensional spacetime. We also observe that it is due to nongravitational interactions. We construct wave functions and vertex operators which realize the D=6, (2,0) tensor representation. We also comment on other little analogues of the IIB matrix model and Matrix Theory with less supercharges.

Kitazawa, Yoshihisa; Mizoguchi, Shun'Ya; Saito, Osamu

2006-08-01

301

Glueball Matrix Elements on Anisotropic Lattices  

SciTech Connect

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

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

2004-03-01

302

Novel formulations of CKM matrix renormalization  

SciTech Connect

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.

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

303

Matrix Analytic Methods for Stochastic Fluid Flows  

NSDL National Science Digital Library

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

Ramaswami V.

2009-03-12

304

Simple matrix models for random Bergman metrics  

NASA Astrophysics Data System (ADS)

Recently, the authors have proposed a new approach to the theory of random metrics, making an explicit link between probability measures on the space of metrics on a Kähler manifold and random matrix models. We consider simple examples of such models and study the one- and two-point functions of the metric. These geometric correlation functions correspond to new interesting types of matrix model correlators. We provide in particular a detailed study of the Wishart model, where we determine the correlation functions explicitly. We find that the random measure in this model turns out to be concentrated on the background metric in the large N limit.

Ferrari, Frank; Klevtsov, Semyon; Zelditch, Steve

2012-04-01

305

Matrix Metalloproteinases: Regulators of the Tumor Microenvironment  

PubMed Central

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

Kessenbrock, Kai; Plaks, Vicki; Werb, Zena

2010-01-01

306

Fabrication of metal matrix composites of  

Microsoft Academic Search

Fine fibrous titanium carbide (TiC) was processed through the self-propagating high-temperature synthesis (SHS) method and\\u000a employed to fabricate aluminum matrix composites. Two consol-idation methods were investigated: (1) combustion synthesis of\\u000a TiC fiber\\/Al composites directly using titanium powders and carbon fibers ignited simultaneously with varying amounts of the\\u000a matrix metal powder and (2) combustion synthesis of TiC using titanium powders and

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

1992-01-01

307

Neutrino light to photon light converting matrix  

US Patent & Trademark Office Database

Apparatus for viewing in neutrino light first uses microwaves to create neutrino force differentials on piezoelectric material. The force differentials are used by elements of a matrix to create pixels of a two dimensional picture for use in viewing of underground structures from a satellite. In another form pixels are formed on an LCD display for direct human viewing.

Beckwith; Robert W. (Clearwater, FL)

2005-05-10

308

Porcelain Jacket Crown, Pt 1, The Matrix.  

National Technical Information Service (NTIS)

Depicts the various laboratory steps involved in the fabrication of a porcelain jacket crown. The die must have a non-undercut apron on the root section for a distance of several millimeters apical to the margin. The matrix is fabricated for dead soft pla...

1994-01-01

309

Porcelain Jacket Crown, Pt 1, The Matrix.  

National Technical Information Service (NTIS)

Depicts the various laboratory steps involved in the fabrication of a porcelain jacket crown. The die must have a non-undercut apron on the root section for a distance of several millimeters apical to the margin. the matrix is fabricated for dead soft pla...

1994-01-01

310

Sparse matrix algorithms on distributed memory multiprocessors  

SciTech Connect

Progress was made in creating algorithms and software for large-scale sparse matrix computations on advanced distributed-memory parallel machines during the past year. This report is divided into: large-scale linear systems; highly parallel triangular solution; spectral nested dissection orderings; parallel multifrontal factorization; structure of orthogonal factors; and sparse bases for the range space and the null space.

Pothen, A.

1993-01-01

311

["Archaic matrix of the oedipus complex"].  

PubMed

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

Vogt, R

1990-10-01

312

Non-Hermitian Euclidean random matrix theory.  

PubMed

We develop a theory for the eigenvalue density of arbitrary non-Hermitian Euclidean matrices. Closed equations for the resolvent and the eigenvector correlator are derived. The theory is applied to the random Green's matrix relevant to wave propagation in an ensemble of pointlike scattering centers. This opens a new perspective in the study of wave diffusion, Anderson localization, and random lasing. PMID:21867155

Goetschy, A; Skipetrov, S E

2011-07-29

313

Galvanic Corrosion of Aluminum-Matrix Composites.  

National Technical Information Service (NTIS)

Galvanic-corrosion rates of Al-matrix composites were high in aerated chloride-containing solutions. Oxygen reduction was found to be the primary cathodic reaction. Aluminum corroded by pitting. The type of noble constituent (i.e., graphite, SiC, or TiB2)...

L. H. Hihara R. M. Latanision

1991-01-01

314

Linear matrix inequalities in analysis with multipliers  

Microsoft Academic Search

We show that a number of standard robustness tests can be reinterpreted as special cases of the application of the passivity theorem with the appropriate choice of multipliers. We show how these tests can be performed using convex optimization over linear matrix inequalities.

V. Balakrishnan; Y. Huang; A. Packard; J. Doyle

1994-01-01

315

Powder metal matrix composites: selection and processing  

Microsoft Academic Search

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

M. J Tan; X Zhang

1998-01-01

316

Brain and CNS Histology Rules Matrix  

Cancer.gov

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

317

Metal Matrix Composites: In the driving seat  

Microsoft Academic Search

Over the past thirty years Metal Matrix Composites (MMCs) have emerged as an important class of material within the engineering industry. At present, MMCs offer attractive performance or weight-saving alternatives for a wide range of applications within the sport industry, from Formula 1 racing components to golf club shafts, as they provide beneficial characteristics over existing materials (increased stiffness, strength,

D. Bacon; J. Moffatt; L. Edwards; M. E. Fitzpatrick

318

Wear behaviour of aluminium matrix composite materials  

Microsoft Academic Search

Wear behaviour of aluminium matrix composites is characterized by the dry spindle wear test under various conditions (volume fractions of reinforcements, sliding distances and speeds). Wear resistance of composites is improved due to the presence of reinforcements, but no noticeable improvements are observed in the wear resistance with more than 20% addition of reinforcements. To analyse wear mechanisms, wear surfaces

C. S. Lee; Y. H. Kim; K. S. Han; T. Lim

1992-01-01

319

Machining of aluminium based metal matrix composites  

Microsoft Academic Search

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

S. Barnes; I. R. Pashby

1995-01-01

320

Development of Fiber Reinforced Ceramic Matrix Composites.  

National Technical Information Service (NTIS)

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

J. J. Brennan

1975-01-01

321

Nutritional values for crop diversification matrix  

Microsoft Academic Search

Previously published crop diversification matrices scored 1000 crops species for their tolerances to annual temperature, annual precipitation, pH, and frost?free?drought?free months. These same 1000 species have been classified into four categories each for 16 nutrients. The matrix system enables one to determine rapidly which crops having particular combinations of nutritional parameters will tolerate special ecological situations.

James A. Duke

1977-01-01

322

Revised planning matrix of quality function deployment  

Microsoft Academic Search

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

Wei-Jaw Deng; Ying-Feng Kuo

2008-01-01

323

Design Structure Matrix Methods and Applications  

Microsoft Academic Search

Design structure matrix (DSM) is a straightforward and flexible modeling technique that can be used for designing, developing, and managing complex systems. DSM offers network modeling tools that represent the elements of a system and their interactions, thereby highlighting the system’s architecture (or designed structure). Its advantages include compact format, visual nature, intuitive representation, powerful analytical capacity, and flexibility. Used

Steven D. Eppinger; Tyson R. Browning

324

Product configuration analysis with design structure matrix  

Microsoft Academic Search

Purpose – Product configurator is a sales and production-planning tool that helps to transform customer requirements into bills-of-materials, lists of features and cost estimations. The purpose of this paper is to introduce a method of how to analyse sales configuration models by using a design structure matrix (DSM) tool. By applying the DSM techniques, the sales configuration managers may sequence

P. T. Helo

2006-01-01

325

Development projects scheduling and design structure matrix  

Microsoft Academic Search

Many researchers have highlighted weaknesses of traditional approaches, such as PERT and CPM, in scheduling product development projects and in particular their failure to model iteration. The design structure matrix (DSM) method provides a practical and useful tool to deal with this issue. The advantages of DSM representation and analysis techniques have led to their increasing use in project planning,

Y. J. Qian; T. N. Goh

2007-01-01

326

The algebras of large N matrix mechanics  

SciTech Connect

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

Halpern, M.B.; Schwartz, C.

1999-09-16

327

Science Unlimited: Grades K-6 Competency Matrix.  

ERIC Educational Resources Information Center

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

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

328

Cell Traction Forces Direct Fibronectin Matrix Assembly  

PubMed Central

Abstract Interactions between cells and the surrounding matrix are critical to the development and engineering of tissues. We have investigated the role of cell-derived traction forces in the assembly of extracellular matrix using what we believe is a novel assay that allows for simultaneous measurement of traction forces and fibronectin fibril growth at discrete cell-matrix attachment sites. NIH3T3 cells were plated onto arrays of deformable cantilever posts for 2–24 h. Data indicate that developing fibril orientation is guided by the direction of the traction force applied to that fibril. In addition, cells initially establish a spatial distribution of traction forces that is largest at the cell edge and decreases toward the cell center. This distribution progressively shifts from a predominantly peripheral pattern to a more uniform pattern as compressive strain at the cell perimeter decreases with time. The impact of these changes on fibrillogenesis was tested by treating cells with blebbistatin or calyculin A to tonically block or augment, respectively, myosin II activity. Both treatments blocked the inward translation of traction forces, the dissipation of compressive strain, and fibronectin fibrillogenesis over time. These data indicate that dynamic spatial and temporal changes in traction force and local strain may contribute to successful matrix assembly.

Lemmon, Christopher A.; Chen, Christopher S.; Romer, Lewis H.

2009-01-01

329

Research on Graphite Reinforced Glass Matrix Composites.  

National Technical Information Service (NTIS)

High levels of mechanical performance in tension, flexure, fatigue, and creep loading situations of graphite fiber reinforced glass matrix composites are discussed. At test temperatures of up to 813 K it was found that the major limiting factor was the ox...

K. M. Prewo E. R. Thompson

1980-01-01

330

S-matrix theory of nuclear forces  

SciTech Connect

The use of the S-matrix theory for deriving the nucleon-nucleon interaction is reviewed. Fits to recent NN data are described. Applications to nuclear structure properties and nucleon-nucleus reactions are also discussed, and the results compared with data. 20 references.

Vinh Mau, R.

1984-09-01

331

Zeroes in continuum - continuum dipole matrix elements  

NASA Astrophysics Data System (ADS)

It is well known that Cooper minima in photoeffect cross sections are due to zeroes in corresponding bound-free dipole matrix elements. As was discussed before(C. D. Shaffer, R. H. Pratt, and S. D. Oh, Phys. Rev. A. 57), 227 (1998)., free-free dipole matrix elements in screened (atomic or ionic) potentials can also have zeroes. Such zeroes (existing at energies of the order of 1-100 eV) result in structures in the energy dependence of bremsstrahlung cross sections and angular distributions(A. Florescu, O. I. Obolensky, C. D. Shaffer, and R. H. Pratt, AIP Conference Proceedings, 576), 60 (2001).. In the soft photon limit, zeroes of radiative free-free matrix elements are related to Ramsauer-Townsend minima in elastic scattering of electrons by atoms. Here we study properties of the trajectories of dipole matrix element zeroes in the plane of initial and final electron energies. We show how the trajectories in this plane evolve with ionicity for several low ? dipole transitions ? ? ? ± 1.

Obolensky, Oleg I.; Pratt, R. H.; Korol, Andrei

2003-05-01

332

Global Aspects of the Matrix Riccati Equation  

Microsoft Academic Search

Matrix Riccati equations are interpreted as differential equations on Grassman manifolds. Necessary conditions for the Riccati equation to be a Morse-Smale system are given in the autonomous and periodic cases. Under this condition, the equation is structurally stable and has a unique asymptotically stable equilibrium point or periodic solution.

C. R. Schneider

1973-01-01

333

Level Spacing Distributions of Random Matrix Ensembles  

Microsoft Academic Search

A formalism of nearest-neighbor spacing distribution is presented for the random matrix ensembles related to general orthogonal polynomials. We show that the spacing distributions are derived from certain integral equations written in terms of the corresponding orthogonal or skew orthogonal polynomials. By using the formalism the universality of the spacing distribution is proved in special cases related to classical orthogonal

Masahiro Shiroishi; Taro Nagao; Miki Wadati

1993-01-01

334

Cardiac matrix alterations induced by adriamycin.  

PubMed Central

Adriamycin is toxic to humans and animals and causes cardiac lesions involving myocytes and the interstitial tissue. The present study used a single injection of adriamycin in rats. Focal loss of myocardial interstitial collagen occurred 2 weeks after a single injection of adriamycin. These foci become larger and more frequent through 6 weeks. Individual variation in response is evident after periods longer than 6 weeks. Concomitant with the focal loss is deposition of collagen in an abnormal distribution. Rather than the normal matrix being present, scars appear. The number and size of these scars is subject to variation from animal to animal. The collagen matrix loss is evident in some animals at 15 weeks after injection. These observations, coupled with the results of other studies on the myocardial collagen matrix, support the hypothesis that adriamycin cardiotoxicity is mediated in part by an affect on the collagen matrix. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Caulfield, J. B.; Bittner, V.

1988-01-01

335

The Bushido Matrix for Couple Communication  

ERIC Educational Resources Information Center

|The concept of Japanese Bushido and its seven virtues were introduced by the authors in this article for the practice and application of couple communication. The Bushido Matrix Worksheet (BMW) was created for enhancing couple's awareness and understanding of each other's values and experiences. An activity and a case study to demonstrate the use…

Li, Chi-Sing; Lin, Yu-Fen; Ginsburg, Phil; Eckstein, Daniel

2012-01-01

336

Derive Workshop Matrix Algebra and Linear Algebra.  

ERIC Educational Resources Information Center

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

Townsley Kulich, Lisa; Victor, Barbara

337

Fetal Germinal Matrix and Intraventricular Hemorrhage  

Microsoft Academic Search

Subependymal germinal matrix with intraventricular hemorrhage (GMIVH) is a common complication associated with delivery in preterm neonates but has rarely been observed in the fetus. Clinical and neuroradiological findings of 5 patients who were diagnosed as having fetal GMIVH with prenatal ultrasonographic examinations (US) and MRI, and postnatal MRI were reviewed retrospectively. During a seemingly uneventful pregnancy, fetal GMIVH occurred

Takato Morioka; Kimiaki Hashiguchi; Shinji Nagata; Yasushi Miyagi; Futoshi Mihara; Shunji Hikino; Kiyomi Tsukimori; Tomio Sasaki

2006-01-01

338

Bayesian Inference with Probability Matrix Decomposition Models.  

ERIC Educational Resources Information Center

|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)|

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

2001-01-01

339

Holographic geometry and noise in matrix theory  

SciTech Connect

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 dimension of size R are interpreted as transverse position operators for macroscopic bodies. An effective quantum wave equation for spacetime is derived from the matrix Hamiltonian. Its solutions display eigenmodes that connect longitudinal separation and transverse position operators on macroscopic scales. Measurements of transverse relative positions of macroscopically separated bodies, such as signals in Michelson interferometers, are shown to display holographic nonlocality, indeterminacy, and noise, whose properties can be predicted with no parameters except R. Similar results are derived using a detailed scattering calculation of the matrix wave function. Current experimental technology will allow a definitive and precise test or validation of this interpretation of holographic fundamental theories. In the latter case, they will yield a direct measurement of R independent of the gravitational definition of the Planck length, and a direct measurement of the total number of degrees of freedom.

Hogan, Craig J. [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Enrico Fermi Institute, Kavli Institute for Cosmological Physics, and Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States); Jackson, Mark G. [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Theory Group, Fermi National Accelerator Laboratory (United States); Lorentz Institute for Theoretical Physics, University of Leiden, Leiden 2333CA (Netherlands)

2009-06-15

340

Lattice QCD and the Ckm Matrix  

NASA Astrophysics Data System (ADS)

These lectures provide an introduction to lattice methods for nonperturbative studies of Quantum Chromodynamics. Lecture 1 (Ch. 2) is a very vanilla introduction to lattice QCD. Lecture 2 (Ch. 3) describes examples of recent lattice calculations relevant to fixing the parameters of the CKM matrix.

Degrand, Thomas

2001-09-01

341

User interface design with matrix algebra  

Microsoft Academic Search

It is usually very hard, both for designers and users, to reason reliably about user interfaces. This article shows that 'push button' and 'point and click' user interfaces are algebraic structures. Users effectively do algebra when they interact, and therefore we can be precise about some important design issues and issues of usability. Matrix algebra, in particular, is useful for

Harold W. Thimbleby

2004-01-01

342

Acidizing concepts - Matrix vs. fracture acidizing  

SciTech Connect

Acidizing involves a wide range of stimulation treatments that can yield impressive production increases in many wells if properly applied. Acidizing treatments are divided into two categories: matrix acidizing and fracture acidizing. To use either treatment properly, an understanding is required of what the treatments do and what is necessary to stimulate the well.

King, G.E.

1986-05-01

343

Silicon carbide yarn reinforced glass matrix composites  

Microsoft Academic Search

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

K. M. Prewo; J. J. Brennan

1982-01-01

344

Biaffine matrix inequality properties and computational methods  

Microsoft Academic Search

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

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

1994-01-01

345

Implant breast reconstruction using acellular dermal matrix.  

PubMed

Thirteen breast reconstructions in 11 patients, averaging 58 years of age, underwent mastectomies. The technique uses a saline implant either totally or partially covered with a human acellular dermal matrix. The mean postoperative follow-up time was 14 months. Ninety percent of the patients were considered high risk; the thickness of the human acellular dermal matrix was an average of 1.3 mm, with an average area per breast of 121 cm. There were 12 successful breast reconstructions (92%) that provided stability, increased soft tissue padding, which allowed a greater resemblance to normal breast shape and decreased rippling and implant visibility. The graft was used in an onlay fashion or as an extension of the pectoralis major muscle that covers the implant. A representative histologic cross-section of well-integrated human acellular dermal matrix is presented. The use of a human acellular dermal matrix in breast reconstruction is an alternative protocol in high-risk patients, resulting in a minimal increase in operative time and a decrease in morbidity compared with more extensive procedures. PMID:16374090

Gamboa-Bobadilla, G Mabel

2006-01-01

346

Strapdown Matrix Orthogonalization: The Dual Iterative Algorithm  

Microsoft Academic Search

There exist several algorithms for the optimal orthogonalization of the Direction Cosine Matrix used in navigation, control and simulation One of these recursive algorithms is shown to be derived from a dual solution to the optimal orthogonalization problem. The duality of the algorithm is demonstrated and its convergence properties are investigated Quadratic convergence is proven and the condition for convergence

L. Y. Bar-Itzhackmber; J. Meyer; P. A. Fuhrmann

1976-01-01

347

Root Coverage Technique with Enamel Matrix Derivative  

Microsoft Academic Search

Various periodontal plastic surgical techniques are employed in obtaining root coverage. Recently, the use of an enamel matrix derivative (EMD) has been reported in such treatment. We report 2 cases of root coverage surgery with a coronally positioned flap in combination with EMD (CPFEMD) and connective tissue graft in combination with EMD (CTGEMD). Case 1: The patient was a 25-year-old

Takafumi Moriyama; Shinya Matsumoto; Takemi Makiishi

2009-01-01

348

Time evolution of Matrix Product States  

Microsoft Academic Search

In this work we develop several new simulation algorithms for 1D many-body quantum mechanical systems combining the Matrix Product State variational ansatz with Taylor, Pade and Arnoldi approximations to the evolution operator. By comparing with previous techniques based on MPS and DMRG we demonstrate that the Arnoldi method is the best one, reaching extremely good accuracy with moderate resources. Finally

Juan Jose Garc ´ õa-Ripoll

349

The Biofilm Matrix: A Sticky Framework  

Microsoft Academic Search

The extracellular matrix of structured microbial communities constitutes the framework that holds the component cells together. Although the presence of cell-to-cell intercon- necting matrices appears to be a common feature of structured microbial communities, there is a remarkable diversity in the composition of these matrices. Compounds such as polysaccharides, fimbriae, mating pili, and extracellular DNA can all function as extracel-

Sünje Johanna Pamp; Morten Gjermansen; Tim Tolker-Nielsen

350

Damped vibration of engine valve train by recent transfer matrix and matrix procedures  

NASA Astrophysics Data System (ADS)

Damped vibrations of engine valve systems have been investigated by multiple degree of freedom models and the recent transfer matrix techniques and complex eigenvalue analysis procedures. The numerical results obtained were compared with the other available procedures including an exact continuous model solution. The multiple degree of freedom models were found to be superior, especially, in predicting forces acting on the engine valve train. The present application of the transfer matrix method with recent developments, gives accurate estimation of the vibration characteristics and harmonic response of engine valve trains. Complex matrix method analysis also supports the obtained results.

Karadag, Vedat

1991-05-01

351

Determination of Matrix Diffusion Properties of Granite  

SciTech Connect

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

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

2007-07-01

352

Role of Interfacial Properties on the Matrix Cracking and Creep Behaviors in Ceramic-Matrix Composites  

SciTech Connect

The primary objectives of the DOE-BES funded research project were (a) to study the roles of interfacial properties and preexisting flaw size on the steady state (long crack) and non-steady state (short crack) first-matrix cracking behaviors in CFCCs over a range of temperatures, and (b) to study the creep and fracture behaviors of composites at elevated temperatures. These goals were achieved via (1) developing processing techniques to fabricate composites with a range of fiber-matrix interfacial properties and flaw sizes, (2) studying the influence of interfacial properties and flaw sizes on the first-matrix cracking behavior over a range of temperatures, (3) developing analytical models to describe experimentally observed matrix cracking behavior in fiber-reinforced composites, and (4) performing creep and fracture studies on these composites at elevated temperatures, including analytical modeling of the creep and fracture resistance behaviors. A significant amount of progress has been made towards accomplishing most of these objectives.

Singh, Raj N.

2002-11-15

353

Fraction-Free Computation of Matrix Rational Interpolants and Matrix GCDs  

Microsoft Academic Search

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

Bernhard Beckermann; George Labahn

2000-01-01

354

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

SciTech Connect

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

Nusbaum, Kurtis Lee

2011-08-01

355

Dependency Structure Matrix Analysis: Offline Utility of the Dependency Structure Matrix Genetic Algorithm  

Microsoft Academic Search

This paper investigates the ofi-line use of the dependency structure matrix genetic algorithm (DSMGA). In particular, a problem-speciflc crossover operator is design by performing depen- dency structure matrix (DSM) analysis. The advantages and disadvantages of such an ofi-line use are discussed. Two schemes that helps the ofi-line usage are proposed. Finally, those ofi-line schemes are demonstrated by DSMGA on MaxTrap

Tian-li Yu; David E. Goldberg

2004-01-01

356

Effect of matrix alloy on longitudinal tensile behavior of fiber reinforced titanium matrix composites  

SciTech Connect

Fiber reinforced titanium matrix composites (Ti MMCs) are of great interest for use in aeronautical gas-turbine engines because of their improved specific strength and stiffness and elevated temperature performance compared to monolithic Ti alloys. The Defence Evaluation and Research Agency is studying Ti MMCs for use in gas-turbine compressor discs. This report investigates the effect of the matrix alloy on the longitudinal tensile behavior of Ti MMCs reinforced with SM1140+ SiC fiber.

Thomas, M.P.; Winstone, M.R. [Defence Evaluation and Research Agency, Farnborough (United Kingdom). Structural Materials Centre

1997-12-15

357

Formation of carbon fiber-reinforced ceramic matrix composites with polysiloxane\\/silicon derived matrix  

Microsoft Academic Search

A ceramic matrix for carbon fiber-reinforced ceramic matrix composites (CMCs) has been developed from poly(methylsilsesquioxane)\\/silicon mixtures, using a low-cost process. In this process the space in two-dimensional carbon fiber preform was filled with a slurry composed by Si powder dispersed into poly(methylsilsesquioxane)\\/trietoxysilane solutions. Three different volume ratio of Si:polymer were used to stack eight-harness plain weave of carbon fiber, forming

R. M. Rocha; C. A. A. Cairo; M. L. A. Graça

2006-01-01

358

Infrared Mueller matrix acquisition and preprocessing system.  

PubMed

An analog Mueller matrix acquisition and preprocessing system (AMMS) was developed for a photopolarimetric-based sensor with 9.1-12.0 microm optical bandwidth, which is the middle infrared wavelength-tunable region of sensor transmitter and "fingerprint" spectral band for chemical-biological (analyte) standoff detection. AMMS facilitates delivery of two alternate polarization-modulated CO(2) laser beams onto subject analyte that excite/relax molecular vibrational resonance in its analytic mass, primes the photoelastic-modulation engine of the sensor, establishes optimum throughput radiance per backscattering cross section, acquires Mueller elements modulo two laser beams in hexadecimal format, preprocesses (normalize, subtract, filter) these data, and formats the results into digitized identification metrics. Feed forwarding of formatted Mueller matrix metrics through an optimally trained and validated neural network provides pattern recognition and type classification of interrogated analyte. PMID:18806864

Carrieri, Arthur H; Owens, David J; Schultz, Jonathan C

2008-09-20

359

Random matrix theory for underwater sound propagation  

NASA Astrophysics Data System (ADS)

Ocean acoustic propagation can be formulated as a wave guide with a weakly random medium generating multiple scattering. Twenty years ago, this was recognized as a quantum chaos problem, and yet random matrix theory, one pillar of quantum or wave chaos studies, has never been introduced into the subject. The modes of the wave guide provide a representation for the propagation, which in the parabolic approximation is unitary. Scattering induced by the ocean's internal waves leads to a power-law random banded unitary matrix ensemble for long-range deep-ocean acoustic propagation. The ensemble has similarities, but differs, from those introduced for studying the Anderson metal-insulator transition. The resulting long-range propagation ensemble statistics agree well with those of full wave propagation using the parabolic equation.

Hegewisch, K. C.; Tomsovic, S.

2012-02-01

360

Eigenvalues and eigenvectors of the transfer matrix  

NASA Astrophysics Data System (ADS)

The work presents theoretical and experimental studies on the binary and ternary solid elastic systems, with the aim to give a method for the determination of the elastic constants of the materials, especially for small ceramic samples. The built-in systems contain a gauge material and the sample of interest. The idea of the work starts from the properties of the intrinsic transfer matrix of the system, which share the same kind of eigenvalues in the resonance case. By explicit computation of the intrinsic transfer matrix of the system it is possible to find the eigenvalues and eigenvectors, and finally by measuring the frequency of the system's eigenmodes it is possible to elaborate a numerical method to compute the phase velocity and consequently the elastic constant of the material. To find experimentally the frequency of the eigenmodes, we used an experimental setup based on the Laser Doppler Interferometry and a measuring chain containing preamplifiers, filters and FFT signal analyzers.

Cretu, Nicolae; Pop, Ioan-Mihail; Rosca, Ioan-Calin

2012-05-01

361

Fetal hypoxia and programming of matrix metalloproteinases  

PubMed Central

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

Tong, Wenni; Zhang, Lubo

2011-01-01

362

Examples of Matrix Factorizations from SYZ  

NASA Astrophysics Data System (ADS)

We find matrix factorization corresponding to an anti-diagonal in CP^1 × CP^1, and circle fibers in weighted projective lines using the idea of Chan and Leung of Strominger-Yau-Zaslow transformations. For the tear drop orbifolds, we apply this idea to find matrix factorizations for two types of potential, the usual Hori-Vafa potential or the bulk deformed (orbi)-potential. We also show that the direct sum of anti-diagonal with its shift, is equivalent to the direct sum of central torus fibers with holonomy (1,-1) and (-1,1) in the Fukaya category of CP^1 × CP^1, which was predicted by Kapustin and Li from B-model calculations.

Cho, Cheol-Hyun; Hong, Hansol; Lee, Sangwook

2012-08-01

363

Extracellular matrix biology in the lung.  

PubMed

The lung and other organs are comprised of both cellular and extracellular compartments. Interaction of these components modulates physiological function at the organ, cellular, and subcellular levels. Extracellular components in the gas-exchange region of the lung include both noncellular interstitium and basement membranes. Connective tissue elements of the interstitium in part determine ventilatory function by contributions to tissue compliance and to resistance of the diffusion barrier. The basement membrane underlies cells of both the alveolar epithelium and the capillary endothelium; basement membrane components exert biological effects on adjacent cells through receptor-mediated interactions. This review emphasizes current knowledge concerning the composition and biological activity of extracellular matrix in the alveolar region of the lung. Matrix synthesis and turnover are also considered. Directions for future research are suggested in the context of current knowledge of the lung and other model systems. PMID:8772523

Dunsmore, S E; Rannels, D E

1996-01-01

364

Matrix proteases in mitochondrial DNA function  

PubMed Central

Lon, ClpXP and m-AAA are the three major ATP-dependent proteases in the mitochondrial matrix. All three are involved in general quality control by degrading damaged or abnormal proteins. In addition to this role, they are predicted to serve roles in mitochondrial DNA functions including packaging and stability, replication, transcription and translation. In particular, Lon has been implicated in mtDNA metabolism in yeast, fly and humans. Here, we review the role of Lon protease in mitochondrial DNA functions, and discuss a putative physiological role for mitochondrial transcription factor A (TFAM) degradation by Lon protease. We also discuss the possible roles of m-AAA and ClpXP in mitochondrial DNA functions, and the putative candidate substrates for the three matrix proteases.

Matsushima, Yuichi; Kaguni, Laurie S.

2012-01-01

365

Matrix proteases in mitochondrial DNA function.  

PubMed

Lon, ClpXP and m-AAA are the three major ATP-dependent proteases in the mitochondrial matrix. All three are involved in general quality control by degrading damaged or abnormal proteins. In addition to this role, they are proposed to serve roles in mitochondrial DNA functions including packaging and stability, replication, transcription and translation. In particular, Lon has been implicated in mtDNA metabolism in yeast, fly and humans. Here, we review the role of Lon protease in mitochondrial DNA functions, and discuss a putative physiological role for mitochondrial transcription factor A (TFAM) degradation by Lon protease. We also discuss the possible roles of m-AAA and ClpXP in mitochondrial DNA functions, and the putative candidate substrates for the three matrix proteases. This article is part of a Special Issue entitled: Mitochondrial Gene Expression. PMID:22172992

Matsushima, Yuichi; Kaguni, Laurie S

2011-12-08

366

Influence of Binder in Iron Matrix Composites  

SciTech Connect

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

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

2010-03-11

367

Quantitative matrix assisted plasma desorption mass spectrometry  

NASA Astrophysics Data System (ADS)

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

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

1993-07-01

368

Cellular control of connective tissue matrix tension.  

PubMed

The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function, and cancer. PMID:23444198

Langevin, Helene M; Nedergaard, Maiken; Howe, Alan K

2013-08-01

369

Delocalization transition for the Google matrix.  

PubMed

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

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

2009-08-07

370

On matrix representation of some finite groups  

NASA Astrophysics Data System (ADS)

A homomorphism T:g-->T(g) of G into GL(M) is a representation of G with representation space M. Two representations T and T' with space M and M' are said to be equivalent if there exists a K-isomorphism S of M and M'. The notation (M:K) is the dimension of M over K where M is a vector space and K is a field while G is a finite group. A matrix representation of G of degree n is a homomorphism T:g-->T(g) of G into GL(n, K), where GL(n, K) stands for the group of invertible n × n matrices over K. In this paper, the matrix representations for dihedral groups of order 12 and order 16 and an alternating group of order 12 are presented.

Mohd Adnan, Noor Asma'Adny; Sarmin, Nor Haniza; Mohd Ali, Nor Muhainiah; Yahya, Zainab; Zakaria, Mardhiah

2013-04-01

371

Integrins and Extracellular Matrix in Mechanotransduction  

PubMed Central

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

Schwartz, Martin Alexander

2010-01-01

372

Response matrix transport calculations on parallel computers  

SciTech Connect

The response matrix method offers an excellent vehicle for adapting three-dimensional neutron transport methods to parallel computers. Our current thrust is in utilizing the three-dimensional Variational nodal code VARIANT as a point of departure for performing three- dimensional parallel computations on the IBM SPx at Argonne National Laboratory. The code employs a planar red-black iteration with a secondary red-black or four-color iteration within each plane. Speed- up and efficiency results have been obtained with a two-stage parallel implementation. First, the response matrix coefficients are calculated in parallel for each unique node type. Second, parallel iterations are performed with one red-black pair of planes assigned to each processor. A hierarchical structure may be employed to obtain finer parallel granularity by assigning multiple processors to the planer red-black or four-color iterations.

Hanebutte, U.R.; Palmiotti, G.; Khalil, H.S. [Argonne National Lab., IL (United States). Reactor Analysis Div.; Tatsumi, M. [Nuclear Fuel Industries, Ltd., Osaka (Japan). Nuclear Engineering Div.; Lewis, E.E. [Northwestern Univ., Evanston, IL (United States). Dept. of Mechanical Engineering

1996-12-31

373

Matrix control of transforming growth factor-? function  

PubMed Central

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

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

2012-01-01

374

Electrophilic properties of common MALDI matrix molecules  

NASA Astrophysics Data System (ADS)

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

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

2007-11-01

375

Noncommutative gauge theories on as matrix models  

NASA Astrophysics Data System (ADS)

We study a class of noncommutative gauge theory models on 2-dimensional Moyal space from the viewpoint of matrix models and explore some related properties. Expanding the action around symmetric vacua generates non local matrix models with polynomial interaction terms. For a particular vacuum, we can invert the kinetic operator which is related to a Jacobi operator. The resulting propagator can be expressed in terms of Chebyschev polynomials of second kind. We show that non vanishing correlations exist at large separations. General considerations on the kinetic operators stemming from the other class of symmetric vacua, indicate that only one class of symmetric vacua should lead to fast decaying propagators. The quantum stability of the vacuum is briefly discussed.

Martinetti, Pierre; Vitale, Patrizia; Wallet, Jean-Christophe

2013-09-01

376

Matrix representation of the time operator  

SciTech Connect

In quantum mechanics the time operator {Theta} satisfies the commutation relation [{Theta}, 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 {Theta} by {Theta}+{Theta}{sub hom}, where {Theta}{sub hom} satisfies the homogeneous condition [{Theta}{sub hom}, H]= 0. To study this nonuniqueness the matrix elements of {Theta} 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 {Theta} simplify dramatically. However, it is still not clear whether there is an optimally simple representation of the time operator.

Bender, Carl M. [Department of Physics, Kings College London, Strand, London WC2R 1LS (United Kingdom); Gianfreda, Mariagiovanna [Dipartimento di Matematica e Fisica, Universita del Salento and I.N.F.N. Sezione di Lecce, Via Arnesano, I-73100 Lecce (Italy)

2012-06-15

377

Heavy-to-light chromomagnetic matrix element  

NASA Astrophysics Data System (ADS)

We report the computation of the matrix element of the chromomagnetic operator of the flavour changing neutral current (FCNC)-type between a B- or D-meson state and a light hadron & an off-shell photon. The computation is carried out by using the light-cone sum rules (LCSR). It is found that the matrix element exhibits large strong phase for which we give a long distance interpretation. The analytic structure of the correlation function in use admits a complex anomalous threshold on the physical sheet. The meaning and handling within the sum rule approach of the latter is discussed. We compare our results to QCD factorisation for which spectator photon emission is end-point divergent.

Dimou, Maria; Lyon, James; Zwicky, Roman

2013-08-01

378

Geometric applications of a matrix searching algorithm  

Microsoft Academic Search

Let A be a matrix with real entries and let j(i) be the index of the leftmost column containing the maximum value in row i ofA. A is said to be monotone if il > i2 implies thatj(il) >-j(i2). A is totally monotone if all of its submatrices are monotone. We show that finding the maximum entry in each row

Alok Aggarwal; Maria M. Klawe; Shlomo Moran; Peter W. Shor; Robert E. Wilber

1986-01-01

379

Graphite matrix materials for nuclear waste isolation  

SciTech Connect

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.

Morgan, W.C.

1981-06-01

380

Metal-matrix composites in ground transportation  

Microsoft Academic Search

Metal-matrix composites (MMCs) are used in a variety of automotive and other ground transp ortation applications. This article\\u000a provides a brief overview of the major applications of MMCs in ground transportation. The main attractive features of MMCs\\u000a are: high strength-to-weight ratio, enhanced mechanical and thermal properties over conventional materials, improved fatigue\\u000a and creep characteristics, better wear resistance, and general tailorability

N. Chawla; K. K. Chawla

2006-01-01

381

Wear behaviour of aluminium matrix composite materials  

Microsoft Academic Search

Wear behaviour of aluminium matrix composites is characterized by the dry spindle wear test under various conditions (volume\\u000a fractions of reinforcements, sliding distances and speeds). Wear resistance of composites is improved due to the presence\\u000a of reinforcements, but no noticeable improvements are observed in the wear resistance with more than 20% addition of reinforcements.\\u000a To analyse wear mechanisms, wear surfaces

C. S. Lee; Y. H. Kim; K. S. Han; T. Lim

1992-01-01

382

Nonnegative Matrix Factorization with Gaussian Process Priors  

PubMed Central

We present a general method for including prior knowledge in a nonnegative matrix factorization (NMF), based on Gaussian process priors. We assume that the nonnegative factors in the NMF are linked by a strictly increasing function to an underlying Gaussian process specified by its covariance function. This allows us to find NMF decompositions that agree with our prior knowledge of the distribution of the factors, such as sparseness, smoothness, and symmetries. The method is demonstrated with an example from chemical shift brain imaging.

Schmidt, Mikkel N.; Laurberg, Hans

2008-01-01

383

A direct method for BBD matrix inversion  

SciTech Connect

In VLSI circuit simulation, large systems of equations are solved. In order to do that the system is partitioned into groups of tightly coupled variables, called blocks, such as the subcircuits in the VLSI structure. Further, the equations are ordered by subcircuits to produce a matrix in a bordered block diagonal form. Each diagonal block represents the internal variables of a subcircuit, and the border represents the interconnections among the subcircuits.

Milovanovic, I.Z.; Kovacevic, M.A.; Stojcev, M.K.; Milovanovic, E.I.

1994-11-01

384

Low-power SXGA active matrix OLED  

Microsoft Academic Search

This paper presents the design and first evaluation of a full-color 1280×3×1024 pixel, active matrix organic light emitting diode (AMOLED) microdisplay that operates at a low power of 200mW under typical operating conditions of 35fL, and offers a precision 30-bit RGB digital interface in a compact size (0.78-inch diagonal active area). The new system architecture developed by eMagin for the

Ihor Wacyk; Olivier Prache; Amal Ghosh

2009-01-01

385

Identification of a Mammalian Melanosomal Matrix Glycoprotein  

Microsoft Academic Search

Antiserum raised in rabbits against the Triton X-100 insoluble fraction of melanosomes from mouse melanoma cells specifically decorates the internal matrix of melanosomes in immunoelectron microscopy. In metabolic labeling studies, the antiserum recognizes a protein of 94 kDa, which is processed to a band of 53 kDa. Whereas the precursor is relatively soluble in buffers containing Triton X-100, the processed

Seth J. Orlow; Bao-Kang Zhou; Raymond E. Boissy; Sharon Pifko-Hirst

1993-01-01

386

Determination of Matrix Diffusion Properties of Granite  

Microsoft Academic Search

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

Pirkko Holtta; Marja Siitari-Kauppi; Nina Huittinen; Antti Poteri

2007-01-01

387

A silica matrix biosorbent of cadmium  

Microsoft Academic Search

In the process of preparation of a non-toxic metal biosorbent by entrapment of yeast cells in silica matrix by sol–gel technique, the homogeneity of yeast cell dispersion and prevention of precipitation during tetraethoxysilane pre-polymerization were found to be the parameters substantially influencing the sorption capacity for Cd2+. Ultrasonic treatment of cell walls increased the sorption capacity by 25% as a

S. Marseaut; A. Debourg; P. Dostálek; J. Votruba; G. Kuncová; John M. Tobin

2004-01-01

388

Mueller matrix decomposition for biological tissue analysis  

NASA Astrophysics Data System (ADS)

This study deals with the polarimetric characterization of biological tissues based on the Stokes-Mueller formalism. The optimal experimental conditions to study irradiated pig skin samples are analyzed. Two Mueller matrix decomposition techniques, the one developed by Lu and Chipman and the other by Ossikovski, are used. These decompositions allow identification of useful factors such as retardance, diattenuation and depolarization for differentiating between various levels of irradiation and for better interpreting the behavior of the skin with respect to irradiation.

Martin, L.; Le Brun, G.; Le Jeune, B.

2013-04-01

389

A Matrix Formalism for Landau Damping  

SciTech Connect

Existing methods of analyzing the effect of bunch-to-bunch tune shifts on coupled bunch instabilities are applicable to beams with a single unstable mode, or a few non-interacting unstable modes. We present a more general approach that involves computing the eigenvalues of a reduced state matrix. The method is applied to the analysis of PEP-II longitudinal coupled bunch modes, a large number of which are unstable in the absence of feedback.

Prabhakar, Shyam

1998-10-20

390

Ceramic matrix composites containing carbon nanotubes  

Microsoft Academic Search

Due to the remarkable physical and mechanical properties of individual, perfect carbon nanotubes (CNTs), they are considered\\u000a to be one of the most promising new reinforcements for structural composites. Their impressive electrical and thermal properties\\u000a also suggest opportunities for multifunctional applications. In the context of inorganic matrix composites, researchers have\\u000a particularly focussed on CNTs as toughening elements to overcome the

Johann Cho; Aldo R. Boccaccini; Milo S. P. Shaffer

2009-01-01

391

Effective dynamics of the matrix big bang  

Microsoft Academic Search

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

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

2006-01-01

392

Brane creation in M(atrix) theory  

Microsoft Academic Search

We discuss, in the context of M(atrix) theory, the creation of a membrane suspendend between two longitudinal five-branes when they cross each other. It is shown that the membrane creation is closely related to the degrees of freedom in the off-diagonal blocks which are related via dualities to the chiral fermionic zero mode on a 0-8 string. In the dual

Pei-Ming Ho; Yong-Shi Wu

1998-01-01

393

A random matrix approach to VARMA processes  

Microsoft Academic Search

We apply random matrix theory to derive the spectral density of large sample covariance matrices generated by multivariate VMA(q), VAR(q) and VARMA(q1, q2) processes. In particular, we consider a limit where the number of random variables N and the number of consecutive time measurements T are large but the ratio N\\/T is fixed. In this regime, the underlying random matrices

Zdzislaw Burda; Andrzej Jarosz; Maciej A. Nowak; Malgorzata Snarska

2010-01-01

394

Indentation Tests on Al Matrix Syntactic Foams  

Microsoft Academic Search

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

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

395

Matrix metalloproteinase inhibition by green tea catechins  

Microsoft Academic Search

We have investigated the effects of different biologically active components from natural products, including green tea polyphenols (GTP), resveratrol, genistein and organosulfur compounds from garlic, on matrix metalloproteinase (MMP)-2, MMP-9 and MMP-12 activities. GTP caused the strongest inhibition of the three enzymes, as measured by fluorescence assays using gelatin or elastin as substrates. The inhibition of MMP-2 and MMP-9 caused

Michel Demeule; Mathieu Brossard; Martine Pagé; Denis Gingras; Richard Béliveau

2000-01-01

396

Synthetic nano-scale fibrous extracellular matrix.  

PubMed

Biodegradable polymers have been widely used as scaffolding materials to regenerate new tissues. To mimic natural extracellular matrix architecture, a novel highly porous structure, which is a three-dimensional interconnected fibrous network with a fiber diameter ranging from 50 to 500 nm, has been created from biodegradable aliphatic polyesters in this work. A porosity as high as 98.5% has been achieved. These nano-fibrous matrices were prepared from the polymer solutions by a procedure involving thermally induced gelation, solvent exchange, and freeze-drying. The effects of polymer concentration, thermal annealing, solvent exchange, and freezing temperature before freeze-drying on the nano-scale structures were studied. In general, at a high gelation temperature, a platelet-like structure was formed. At a low gelation temperature, the nano-fibrous structure was formed. Under the conditions for nano-fibrous matrix formation, the average fiber diameter (160-170 nm) did not change statistically with polymer concentration or gelation temperature. The porosity decreased with polymer concentration. The mechanical properties (Young's modulus and tensile strength) increased with polymer concentration. A surface-to-volume ratio of the nano-fibrous matrices was two to three orders of magnitude higher than those of fibrous nonwoven fabrics fabricated with the textile technology or foams fabricated with a particulate-leaching technique. This synthetic analogue of natural extracellular matrix combined the advantages of synthetic biodegradable polymers and the nano-scale architecture of extracellular matrix, and may provide a better environment for cell attachment and function. PMID:10357136

Ma, P X; Zhang, R

1999-07-01

397

Plastic matrix composites with continuous fiber reinforcement  

SciTech Connect

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.

NONE

1991-09-19

398

Human Gait Recognition With Matrix Representation  

Microsoft Academic Search

Human gait is an important biometric feature. It can be perceived from a great distance and has recently attracted greater attention in video-surveillance-related applications, such as closed-circuit television. We explore gait recognition based on a matrix representation in this paper. First, binary silhouettes over one gait cycle are averaged. As a result, each gait video sequence, containing a number of

Dong Xu; Shuicheng Yan; Dacheng Tao; Lei Zhang; Xuelong Li; Hong-Jiang Zhang

2006-01-01

399

? 3 as an Upper Triangular Matrix  

Microsoft Academic Search

In the 2-local stable homotopy category the group of left-bu-module automorphisms of bu ? bo which induce the identity on mod 2 homology is isomorphic to the group of infinite, invertible upper triangular matrices\\u000a with entries in the 2-adic integers. We identify the conjugacy class of the matrix corresponding to 1? ?3, where ?3 is the Adams operation.

Jonathan Barker; Victor Snaith

2005-01-01

400

CHANGING EXTRACELLULAR MATRIX LIGANDS DURING METASTASIS  

Microsoft Academic Search

Cellular homeostasis is achieved by cells continuously sending and receiving information, through cell-cell contacts, signals\\u000a from the surrounding extracellular matrix (ECM), or from soluble hormones and growth factors. During cancer progression, these\\u000a normal signals may be altered in a variety of ways forcing extracellular and intracellular changes to occur that will favor\\u000a metastasis. Altering ECM ligands is a major mechanism

Elisabeth L. Bair; Raymond B. Nagle

401

Proton decay matrix elements from lattice QCD  

NASA Astrophysics Data System (ADS)

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.

Aoki, Yasumichi; Shintani, Eigo; RBC; UKQCD Collaborations

2012-07-01

402

Proton decay matrix elements from lattice QCD  

SciTech Connect

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.

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

403

A matrix CCD camera for astronomical observations  

NASA Astrophysics Data System (ADS)

A CCD camera based on a liquid-nitrogen-cooled virtual-phase buried-channel CCD matrix is described. High-resolution spectra of stars obtained at the 2.6-m reflector with this camera are presented. The comparison of the spectra taken with the new camera and with the CCD-2000 camera at the same telescope shows that the new camera is more sensitive within the entire spectral range from 3940 to 10,830 A.

Beriozin, V. Yu.; Zuyev, A. G.; Kiryan, G. V.; Rybakov, M. I.; Khvilivitsky, A. T.; Ilyin, I. V.; Petrov, P. P.; Savanov, I. S.; Scherbakov, A. G.

1991-10-01

404

Low-rank matrix factorization with attributes  

Microsoft Academic Search

We develop a new collaborative filtering (CF) method that combines both previously known users' preferences, i.e. standard CF, as well as product\\/user attributes, i.e. classical function approximation, to predict a given user's interest in a particular product. Our method is a generalized low rank matrix completion problem, where we learn a function whose inputs are pairs of vectors - the

Jacob Abernethy; Francis Bach; Theodoros Evgeniou; Jean-Philippe Vert

2006-01-01

405

Duality in random matrix ensembles for all ?  

Microsoft Academic Search

Gaussian and Chiral ?-Ensembles, which generalise well-known orthogonal (?=1), unitary (?=2), and symplectic (?=4) ensembles of random Hermitian matrices, are considered. Averages are shown to satisfy duality relations like {?,N,n}?{4\\/?,n,N} for all ?>0, where N and n respectively denote the number of eigenvalues and products of characteristic polynomials. At the edge of the spectrum, matrix integrals of the Airy (Kontsevich)

Patrick Desrosiers

2009-01-01

406

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

PubMed

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

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

2013-05-06

407

Quantifying transport properties by exchange matrix method  

NASA Astrophysics Data System (ADS)

The exchange matrix method is described to study of transport properties in chaotic geophysical flows. This study is important for applying in problems of pollutants transport (such as petroleum patches) in tidal flows and others. In order to construct this special exchange matrix (first suggested by Spencer & Wiley) we use an approximation of such flows made by Zimmerman, who adopted the idea of chaotic advection, first put forward by Aref. Then for a quantitative estimation of the transport properties we explore a coarse-grained density description introduced by Gibbs and Welander. Such coarse-grained representations over an investigation area, show a ``residence place'' for the pollutant material at any instant. The orbit expansion method, exploited an assumption that the contributions of tidal and residual currents are of different orders (the tidal is much stronger), does not give answers in many real situations. The exchange matrix can show transport of patches or particles from any place in the area under consideration to an arbitrary location in the tidal sea and time if it happens.

Krasnopolskaya, Tatyana; Meleshko, Vyacheslav

2005-11-01

408

Extracellular matrix rigidity promotes invadopodia activity  

PubMed Central

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

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

2008-01-01

409

Matrix elasticity directs stem cell lineage specification  

NASA Astrophysics Data System (ADS)

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

Discher, Dennis

2010-03-01

410

S-matrix renormalization in effective theories  

NASA Astrophysics Data System (ADS)

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

Semenov-Tian-Shansky, K.; Vereshagin, A.; Vereshagin, V.

2006-01-01

411

Random-matrix theory of quantum transport  

NASA Astrophysics Data System (ADS)

This is a review of the statistical properties of the scattering matrix of a mesoscopic system. Two geometries are contrasted: A quantum dot and a disordered wire. The quantum dot is a confined region with a chaotic classical dynamics, which is coupled to two electron reservoirs via point contacts. The disordered wire also connects two reservoirs, either directly or via a point contact or tunnel barrier. One of the two reservoirs may be in the superconducting state, in which case conduction involves Andreev reflection at the interface with the superconductor. In the case of the quantum dot, the distribution of the scattering matrix is given by either Dyson's circular ensemble for ballistic point contacts or the Poisson kernel for point contacts containing a tunnel barrier. In the case of the disordered wire, the distribution of the scattering matrix is obtained from the Dorokhov-Mello-Pereyra-Kumar equation, which is a one-dimensional scaling equation. The equivalence is discussed with the nonlinear ? model, which is a supersymmetric field theory of localization. The distribution of scattering matrices is applied to a variety of physical phenomena, including universal conductance fluctuations, weak localization, Coulomb blockade, sub-Poissonian shot noise, reflectionless tunneling into a superconductor, and giant conductance oscillations in a Josephson junction.

Beenakker, C. W. J.

1997-07-01

412

Laser surface treatment of aluminium matrix composites  

NASA Astrophysics Data System (ADS)

Absorptance is the base parameter that is determining the energy coupling of a laser radiation into workpiece during its laser treatment. The absorptance for AlSi12/SiCp composites along with their temperature's dependence for the AlSi12 alloy matrix and for wavelengths that correspond to DL, Nd:YAG and CO2 lasers were investigated. Based on the absorptance, the characteristic laser energy densities at which the surface of the metal matrix composite reaches melting temperature were estimated. This estimation was crucial in order to find the bottom level of energy densities, i.e. operational parameter window for AlSi12/SiCp laser melting. Using higher energy densities than the characteristic the surfaces of the AlSi12/SiCp were remelted. In this process the industrial Diode and Nd:YAG lasers were used. Laser remelted composites were subjected to methods of XRD, hardness and residual stress tests. The tests showed that the control of the laser energy density during the laser treatment of the AlSi12/SiCp allowed to obtain a refine structure of the composite matrix. This refine structure is advantageous for the improvements in hardness and corrosion-resistant of the investigated AlSi12/SiCp composite surface.

Grabowski, Andrzej; Moskal, Grzegorz

2013-01-01

413

Analyticity and the Holographic S-Matrix  

SciTech Connect

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

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

2012-04-03

414

Discovery of Conservation Laws via Matrix Search  

NASA Astrophysics Data System (ADS)

One of the main goals of Discovery Science is the development and analysis of methods for automatic knowledge discovery in the natural sciences. A central area of natural science research concerns reactions: how entities in a scientific domain interact to generate new entities. Classic AI research due to Valdés-Pérez, ?ytkow, Langley and Simon has shown that many scientific discovery tasks that concern reaction models can be formalized as a matrix search. In this paper we present a method for finding conservation laws, based on two criteria for selecting a conservation law matrix: (1) maximal strictness: rule out as many unobserved reactions as possible, and (2) parsimony: minimize the L1-norm of the matrix. We provide an efficient and scalable minimization method for the joint optimization of criteria (1) and (2). For empirical evaluation, we applied the algorithm to known particle accelerator data of the type that are produced by the Large Hadron Collider in Geneva. It matches the important Standard Model of particles that physicists have constructed through decades of research: the program rediscovers Standard Model conservation laws and the corresponding particle families of baryon, muon, electron and tau number. The algorithm also discovers the correct molecular structure of a set of chemical substances.

Schulte, Oliver; Drew, Mark S.

415

Study of brazeability of aluminum matrix composites  

SciTech Connect

The brazeability of several aluminum matrix composites has been evaluated in the present paper. Tested materials were two different 6061 aluminum alloys, reinforced with 10 and 20% alumina particles, respectively, and a 7005 aluminum alloy containing 10% alumina also in the form of discrete particles. A drop formation test was selected to evaluate the brazeability of the studied composites, using a commercial filler metal (BAlSi4) generally used for brazing of aluminum alloys. Wettability of molten braze on the metal matrix composites (MMCs) was determined by measurement of the solidified contact angle i n sessile drop tests and determination of the spread area. The wettability and spreading increase with the brazing temperature in the studied range (550--625 C, 1,022--1,157 F), and decrease when the reinforcement proportion is increased. Both properties are also influenced by the type of the composite aluminum matrix being enhanced in the Al-Zn-Mg reinforced alloy. This study was completed with the microstructural characterization of the drop test specimens and of real brazed joints made on T-shaped specimens.

Urena, A.; Salazar, J.M.G. de; Escalera, M.D.; Fernandez, M.I. [Univ. Complutense de Madrid (Spain). Dept. de Ciencia de los Materiales e Ingenieria Metalurgica

1997-02-01

416

Multispectral palmprint recognition using a quaternion matrix.  

PubMed

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

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

2012-04-10

417

Full CKM matrix with lattice QCD  

SciTech Connect

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

Okamoto, Masataka; /Fermilab

2004-12-01

418

Constructing acoustic timefronts using random matrix theory.  

PubMed

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

Hegewisch, Katherine C; Tomsovic, Steven

2013-10-01

419

Culture of hair matrix and follicular keratinocytes.  

PubMed

In recent years, a variety of in vitro models for the cultivation of hair follicles and their constituents have been developed. Outer root sheath (ORS) keratinocytes (KC) have been mainly studied in explant cultures, planted on bovine eye lens capsules, collagen substrata, 3T3 cell feeder layers, or dermal equivalents, yielding outgrowth of a multilayered stratified epithelium with some biochemical and ultrastructural characteristics of keratinocytic differentiation. More recently, ORS KC cultures have also been initiated from single cell suspensions, and organotypic cultures have been obtained by recombination with dermal cells, inducing a higher degree of epidermal differentiation. Presumptive human hair matrix cells have been isolated from plucked anagen hair follicles and have been successfully propagated on 3T3 cell or normal human fibroblast feeder layers, giving rise to multilayered stratified KC cultures. In contrast, only preliminary data exist concerning the cultivation of bulge cells that have been suggested to represent follicular stem cells. In conclusion we dispose of several in vitro models today to cultivate ORS KC and hair matrix cells that have increased our knowledge on the regulation of the human hair cycle by soluble factors and dermal-epidermal interactions. Further comparative studies on ORS KC, bulge cells and matrix cells have to be carried out to confirm the distinct character of these hair KC subsets. PMID:8326146

Detmar, M; Schaart, F M; Blume, U; Orfanos, C E

1993-07-01

420

Gas chromatography/matrix-isolation apparatus  

DOEpatents

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

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

1986-01-01

421

Molecular imprinting in sol-gel matrix.  

PubMed

Molecular imprinting is a newly developed methodology which provides molecular assemblies of desired structures and properties and is being increasingly used for several applications such as in separation processes, microreactors, immunoassays and antibody mimics, catalysis, artificial enzymes, biosensor recognition elements and bio- and chemo-sensors. The ambient processing conditions and versatility of the sol-gel process makes sol-gel glassy matrix suitable for molecular imprinting. The progress of sol-gel based molecular imprinted polymers (MIPs) for various applications can be seen from the growing number of publications. The main focus of the review is molecular imprinting in sol-gel matrix and applications of molecular imprinted sol-gel derived materials for the development of sensors. Combining sol-gel process with molecular imprinting enables to procure the sensors with greater sensitivity and selectivity necessary for sensing applications. The merits, problems, challenges and factors affecting molecular imprinting in sol-gel matrix have been discussed. Considerable attention has been drawn on recent developments like use of organically modified silane precursors (ORMOSILS) for the synthesis of hybrid molecular imprinted polymers (HMIPs) and applying surface sol-gel process for molecular imprinting. The development of molecular imprinted sol-gel nanotubes for biochemical separation and bio-imprinting is a new advancement and is under progress. Templated xerogels and molecularly imprinted sol-gel films provide a good platform for various sensor applications. PMID:18692561

Gupta, Radha; Kumar, Ashok

2008-07-19

422

Multispectral Palmprint Recognition Using a Quaternion Matrix  

PubMed Central

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%.

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

2012-01-01

423

Typicality in random matrix product states  

SciTech Connect

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

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

2010-03-15

424

Ridge Estimation of the Inverse of a Covariance Matrix.  

National Technical Information Service (NTIS)

In many situations the standard estimators for the inverse of a covariance matrix from a normal population provide unsatisfactory results. Proposed as an alternative is a random matrix which undergoes an adjustment similar to that undergone by the normal ...

R. K. Smidt L. L. McDonald

1976-01-01

425

Interphase Layer Optimization for Metal Matrix Composites with Fabrication Considerations.  

National Technical Information Service (NTIS)

A methodology is presented to reduce the final matrix microstresses for metal matrix composites by concurrently optimizing the interphase characteristics and fabrication process. Application cases include interphase tailoring with and without fabrication ...

M. Morel D. A. Saravanos C. C. Chamis

1991-01-01

426

Transformations of Matrix Pencils and Implications in Linear Systems Theory.  

National Technical Information Service (NTIS)

A new transformation of matrix pencils is proposed and its theory formally developed. Its restriction to generalized state space system matrix pencils is shown to be an appropriate generalization of the usual state space transformation and to represent a ...

A. C. Pugh G. E. Hayton P. Fretwell

1986-01-01

427

Graphitic Matrix Materials for Spherical HTR Fuel Elements.  

National Technical Information Service (NTIS)

The present report comprises the essential results of material development and irradiation testing of graphitic matrix materials for spherical HTR fuel elements and completes the documentation of the irradiation data for 20 matrix materials (Juel-1702). T...

W. Rind R. E. Schulze H. A. Schulze

1981-01-01

428

Analysis of the Progressive Failure of Brittle Matrix Composites.  

National Technical Information Service (NTIS)

This report investigates two of the most common modes of localized failures, namely, periodic fiber-bridged matrix cracks and transverse matrix cracks. A modification of Daniels' bundle theory is combined with Weibull's weakest link theory to model the st...

D. J. Thomas

1995-01-01

429

Role of the Topological Distance Matrix in Chemistry.  

National Technical Information Service (NTIS)

The mathematical properties of the topological distance matrix are briefly surveyed and the numerous applications of this matrix to various branches of chemistry are then described. A detailed discussion is devoted to the Wiener index, defined as one half...

D. H. Rouvray

1985-01-01

430

Isolation of the pericellular matrix of human fibroblast cultures  

Microsoft Academic Search

The pericellular matrix of human fibroblast cultures was isolated, using sequential extraction with sodium deoxycholate and hypotonic buffer in the presence of protease inhibitor. The matrix attached to the growth substratum had a \\

KLAUS HEDMAN; MARKKU KURKINEN; KARI ALITALO; I VAHERI; STAFFAN JOHANSSON; MAGNUS HOOK

1979-01-01

431

Involvement of extracellular matrix constituents in breast cancer  

SciTech Connect

It has recently been established that the extracellular matrix is required for normal functional differentiation of mammary epithelia not only in culture, but also in vivo. The mechanisms by which extracellular matrix affects differentiation, as well as the nature of extracellular matrix constituents which have major impacts on mammary gland function, have only now begun to be dissected. The intricate variety of extracellular matrix-mediated events and the remarkable degree of plasticity of extracellular matrix structure and composition at virtually all times during ontogeny, make such studies difficult. Similarly, during carcinogenesis, the extracellular matrix undergoes gross alterations, the consequences of which are not yet precisely understood. Nevertheless, an increasing amount of data suggests that the extracellular matrix and extracellular matrix-receptors might participate in the control of most, if not all, of the successive stages of breast tumors, from appearance to progression and metastasis.

Lochter, Andre; Bissell, Mina J

1995-06-01

432

Mechanical Property Enhancement in Ceramic Matrix Composites, April 1989.  

National Technical Information Service (NTIS)

The fiber-matrix interfacial properties of several glass and ceramic matrix composites have been determined using two indentation techniques and a single fiber pull-out technique. An instrumented indenter was developed to improve the acquisition and analy...

S. W. Freiman D. C. Cranmer M. J. Koczak M. Barsoum E. R. Fuller

1989-01-01

433

Toughening of a Particulate-Reinforced/Ceramic-Matrix Composite.  

National Technical Information Service (NTIS)

The toughening mechanism of particulate-reinforced/ceramic-matrix composites was attributed to the thermal residual stress field induced by the differential thermal expansions of the matrix and the particulate when the composite is cooled from the process...

A. S. Kobayashi H. S. Yoon M. Taya S. Hayashi

1989-01-01

434

Total Diet Study - TDS Food/Analyte Matrix  

Center for Food Safety and Applied Nutrition (CFSAN)

... Pesticide residues, Selected foods (refer to matrix), All foods. VOCs, ... matrix), Other toxic elements, All foods, Lead only – all foods. ... More results from www.fda.gov/food/foodscienceresearch/totaldietstudy

435

Discrete Time Transfer Matrix Method for Multibody System Dynamics  

Microsoft Academic Search

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

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

2005-01-01

436

New integrated acousto-optic matrix algebra processor architecture  

Microsoft Academic Search

A new integrated optic matrix algebra processor architecture that utilizes guided-wave multifrequency acoustooptic (AO) Bragg diffractions is proposed. The architecture is potentially capable of performing matrix-vector multiplications faster than any AO architecture reported heretofore, and matrix-matrix multiplications at rates comparable to the fastest bulk-wave AO architecture. An integrated AO processor module has been realilzed in a Y-cut LiNbO3 substrate 1.0×10.0×28.0

A. Kar-Roy; C. S. Tsai

1991-01-01

437

String coupling and interactions in type IIB matrix model  

SciTech Connect

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

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

2009-05-15

438

A Graphical Method for Solving Interval Matrix Games  

Microsoft Academic Search

$2\\\\times n$ or $m\\\\times 2$ interval matrix games are considered, and a graphical method for solving\\u000asuch games is given. Interval matrix game is the interval generation of\\u000aclassical matrix games. Because of uncertainty in real-world applications,\\u000apayoffs of a matrix game may not be a fixed number. Since the payoffs may vary\\u000awithin a range for fixed strategies, an

Handan Akyar; Emrah Akyar

2011-01-01

439

On unitary\\/Hermitian duality in matrix models  

Microsoft Academic Search

Unitary 1-matrix models are shown to be exactly equivalent to Hermitian 1-matrix models coupled to 2N vectors with appropriate potentials, to all orders in the 1\\/N expansion. This fact allows us to use all the techniques developed and results obtained in Hermitian 1-matrix models to investigate unitary as well as other 1-matrix models with the Haar measure on the unitary

Shun'ya Mizoguchi

2005-01-01

440

Comment on S-matrix parameterizations in NN-scattering  

SciTech Connect

The parameterization of the S-matrix used for the elastic part of the NN-scattering matrix in, for example, the Virginia Polytechnic Institute ineractive nucleon-nucleon program SAID, is not general enough to parameterize any 2 by 2 submatrix of a unitary matrix.

Mulders, P. J.

1981-08-01

441

Matrix Training of Preliteracy Skills with Preschoolers with Autism  

ERIC Educational Resources Information Center

|Matrix training is a generative approach to instruction in which words are arranged in a matrix so that some multiword phrases are taught and others emerge without direct teaching. We taught 4 preschoolers with autism to follow instructions to perform action-picture combinations (e.g., circle the pepper, underline the deer). Each matrix contained…

Axe, Judah B.; Sainato, Diane M.

2010-01-01

442

Micromechanical Characterization of Nonlinear Behavior of Advanced Polymer Matrix Composites.  

National Technical Information Service (NTIS)

Due to the presence of curing stresses and oriented crystalline structures in the matrix of polymer matrix fiber composites, the in situ nonlinear properties of the matrix are expected to be rather different from those of the bulk resin. A plane stress mi...

T. S. Gates J. L. Chen C. T. Sun

1994-01-01

443

Memory Matrix Using Ferroelectric Condensers as Bistable Elements  

Microsoft Academic Search

An electrostaticall y operated multicondenser memory matrix has been produced using ferroelectric dielectric material. Bits of information of bivalued character are stored in terms of bistable remanent polarization. Memory condensers in matrix crosspoints can be acted upon individually for writing or reading, by electrostatic excitation of corresponding matrix leads. Storage of information is permanently remanent and has no power requirements.

Charles F. Pulvari

1955-01-01

444

Silk matrix for tissue engineered anterior cruciate ligaments  

Microsoft Academic Search

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,

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

2002-01-01

445

Silk matrix for tissue engineered anterior cruciate ligaments  

Microsoft Academic Search

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,

Gregory H. Altman; Rebecca L. Horana; Helen H. Lu; Jodie Moreau; John C. Richmond; David L. Kaplan

446

Two-Dimensional Unoriented Strings And Matrix Models  

Microsoft Academic Search

We investigate unoriented strings and superstrings in two dimensions and their dual matrix quantum mechanics. Most of the models we study have a tachyon tadpole coming from the RP2 worldsheet which needs to be cancelled by a renormalization of the worldsheet theory. We find evidence that the dual matrix models describe the renormalized theory. The singlet sector of the matrix

Jaume Gomis; Anton Kapustin

2004-01-01

447

Human fibroblast culture on a crosslinked dermal porcine collagen matrix  

Microsoft Academic Search

The use of a novel porcine-derived collagen biomaterial as a dermal tissue engineering matrix was examined. The matrix is derived from porcine dermis, and is processed to retain the native collagen (Type 1) and elastin structure. Human primary fibroblasts were cultured on the matrix to examine its potential for creating a dermal replacement. Attachment of fibroblasts on the collagen was

Marcus Jarman-Smith; Tulin Bodamyali; Cliff Stevens; John A Howell; Michael Horrocks; Julian B Chaudhuri

2004-01-01

448

Rho Proteins and Cell-Matrix Interactions in Cancer  

Microsoft Academic Search

Dynamic interactions and dissolution of cell-extracellular matrix contacts are required steps to support cell growth and survival during cancer cell metastasis. Malignant cells acquire the ability to remodel extracellular matrix (ECM) and to modulate the expression of ECM receptors. Integrins are cellular receptors for molecules in the extracellular matrix. Integrin signaling is known to regulate metastatic cancer phenotypes by interacting

Mei Wu; Zhi-fen Wu; Sofia D. Merajver

2007-01-01

449

A Matrix Architecture for Development of System Dynamics Models  

Microsoft Academic Search

A matrix architecture for development of system dynamics models is described. The approach concentrates on the formulation of the Forrester stock and flow diagram, and incorporates the concept of an interaction matrix to assist in the formulation of such models. The interaction matrix is formally derived. Set and graph-theoretic concepts are utilized in the derivation. The rules (primitives) of system

James R. Burns; Onur Ulgen

2002-01-01

450

The Community Mental Health Center as a Matrix Organization.  

ERIC Educational Resources Information Center

This article briefly reviews the literature on matrix organizational designs and discusses the ways in which the matrix design might be applied to the special features of a community mental health center. The phases of one community mental health center's experience in adopting a matrix organizational structure are described. (Author)

White, Stephen L.

1978-01-01

451

Investigation of the Electron Spin Resonance Spectra from Matrix Isolated.  

National Technical Information Service (NTIS)

The matrix isolation of C10 in a CO sub 2 matrix is investigated with the aim of providing a detection method for C10 in the stratosphere. Of main concern is the identification and interpretation of the so far unknown ESR-spectrum of matrix isolated C10. ...

M. Trainer

1981-01-01

452

Stress corrosion cracking in a unidirectional ceramic-matrix composite  

Microsoft Academic Search

A study of matrix cracking in a unidirectional ceramic-matrix composite under static loading conditions has been conducted. The evolution of crack density with time has been measured using both flexure and uniaxial tension tests. Subcritical cracking has been observed at stresses below that required to develop matrix cracks in short-duration, monotonic loading tests. Furthermore, a relatively high final crack density

S. Mark Spearing; Frank W. Zok; Anthony G. Evans

1994-01-01

453

Sparse Matrix Libraries in C++ for High Performance Architectures  

Microsoft Academic Search

We describe an object oriented sparse matrix library in C++ designed for portability and performance across a wide class of machine architectures. Besides simplifying the subroutine interface, the object oriented design allows the same driving code to be used for various sparse matrix formats, thus addressing many of the difficulties encountered with the typical approach to sparse matrix libraries. We

Jack Dongarra; Andrew Lumsdaine; Xinhui Niu; Roldan Pozo; Karin Remington

1994-01-01

454

Conversion of a Rhotrix to a "Coupled Matrix"  

ERIC Educational Resources Information Center

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.

Sani, B.

2008-01-01

455

Conversion of a Rhotrix to a "Coupled Matrix"  

ERIC Educational Resources Information Center

|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.|

Sani, B.

2008-01-01

456

Smooth muscle cell matrix metalloproteinases in idiopathic pulmonary arterial hypertension  

Microsoft Academic Search

Pulmonary arterial hypertension (PAH) results from persistent vasoconstriction, smooth muscle growth and extracellular matrix (ECM) remodelling of pulmonary arteries (PAs). Matrix metalloproteinases (MMPs) are matrix-degrading enzymes involved in ECM turnover, and in smooth muscle cell (SMC) and endothelial cell migration and proliferation. MMP expression and activity are increased in experimental PAH. Therefore, this study investigated whether similar changes occur in

H. Lepetit; S. Eddahibi; E. Fadel; E. Frisdal; C. Munaut; A. Noel; M. Humbert; S. Adnot; M. P. D'Ortho; C. Lafuma

2005-01-01

457

Creep rupture in ceramic matrix composites with creeping fibers  

Microsoft Academic Search

A model has been developed for crack growth in an elastic matrix with creeping fibers. Specific solutions have been presented for the steady-state crack growth rate. These solutions provide straightforward connections to the constituent properties through well-known parameters that characterize matrix cracking with elastic fibers. An expression has also been given for the time taken to extend matrix cracks across

M. R. Begley; A. G. Evans; R. M. McMeeking

1995-01-01

458

Condition and Error Estimates in Numerical Matrix Computations  

SciTech Connect

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

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

2008-10-30

459

Influence matrix approach to fault diagnosis and controller tuning  

Microsoft Academic Search

An experimental verification of the influence matrix approach to fault diagnosis and automatic tuning is proposed. The coefficients of the system transfer function are identified and the Jacobian of the coefficient vector with respect to physical parameters, termed the influence matrix, is computed. The influence matrix is used to detect and isolate faults. The optimal controller parameters are obtained using

J. Poshtan; R. Doraiswami

1994-01-01

460

Magnetic field and gradient analysis around matrix for HGMS  

Microsoft Academic Search

A High Gradient Magnetic Separator (HGMS) uses matrix to make high magnetic field gradient so that ferro- or para-magnetic particles can be attracted to them by high magnetic force. These matrixes are usually composed of stainless wires having high magnetization characteristics. This paper deals with superconducting HGMS which is aimed for purifying wastewater by using stainless steel matrix. Background magnetic

S. K. Baik; D. W. Ha; R. K. Ko; J. M. Kwon

2010-01-01

461

Use of matrix attachment regions (MARs) to minimize transgene silencing  

Microsoft Academic Search

Matrix attachment regions (MARs) are operationally defined as DNA elements that bind specifically to the nuclear matrix in vitro. It is possible, although unproven, that they also mediate binding of chromatin to the nuclear matrix in vivo and alter the topology of the genome in interphase nuclei. When MARs are positioned on either side of a transgene their presence usually

George C. Allen; Steven Spiker; William F. Thompson

2000-01-01

462

H ? control for descriptor systems: A matrix inequalities approach  

Microsoft Academic Search

This paper considers the H? control problem for descriptor systems that possibly have impulsive modes and\\/or j?-axis zeros. First, we propose matrix inequalities that give a generalized stability condition and an H? norm condition for descriptor systems. Using these matrix inequalities, we show that the solvability of a set of matrix inequalities is necessary and sufficient to the existence of

Izumi Masubuchi; Yoshiyuki Kamitane; Atsumi Ohara; Nobuhide Suda

1997-01-01

463

Eigenvector matrix partition and radio direction finding performance  

Microsoft Academic Search

The problem of high frequency radio direction finding (HFDF) is solved, using eigenstructure analysis of the spatial correlation matrix. The general approach is to compute a matrix of eigenvectors which are ordered according to decreasing eigenvalues. The eigenvector matrix is partitioned so that one part is associated with signals and the other is associated with noise. The performance of a

R. L. Johnson

1986-01-01

464

Using Matrix with Women Clients. A Supplement to the Matrix Intensive Outpatient Treatment for People with Stimulant Use Disorders.  

National Technical Information Service (NTIS)

The Matrix Intensive Outpatient Treatment for People with Stimulant Use Disorders, Counselors Treatment Manual, originally published in 1995 by the Matrix Center and reproduced by SAMHSA in 2006, has been used by thousands of addiction treatment counselor...

2012-01-01

465

Characterization and enhancement of the fiber-matrix adhesion in pitch-based carbon fiber\\/epoxy matrix composites  

Microsoft Academic Search

The level of fiber-matrix adhesion present in Tonen HM pitch-based carbon fiber\\/EPON 828 epoxy matrix composite materials was characterized. It was determined that the failure of a weak layer on the fiber surface was likely responsible for the poor base case fiber-matrix adhesion. A number of fiber treatments, designed to enhance the strength of the fiber-matrix interfacial bond were evaluated.

1989-01-01

466

Drying of a partially saturated rock matrix by fracture ventilation: Experiments and modeling in a single fracture-matrix system  

Microsoft Academic Search

We present an efficient approach for modeling drying resulting from airflow through fractures embedded within a rock matrix by coupling a nonlinear diffusion equation for moisture transport in the matrix with a depth-averaged quasi steady state advection-dispersion equation for the vapor transport in the fracture. Coupling between the moisture transport equation in the fracture and matrix is achieved by applying

Toshihiro Sakaki; Harihar Rajaram

2009-01-01

467

A protrusion method for measuring fiber/matrix sliding frictional stresses in ceramic matrix composites  

SciTech Connect

A simple technique to measure interfacial frictional shear resistance of fiber-reinforced ceramic matrix composites has been investigated. SiC (CVD) fiber-reinforced soda-borosilicate glass matrix composite containing single fiber was cut into perpendicular to the fiber and was placed on a hard SiC ceramic plate. Ductile metal plate was placed to the upper side of the composite and was subjected to uniform compression via metal plate. After unloading, the protrusion lengths of the fiber at the surface of the composite were measured by scanning electron microscope and the interfacial shear strength was calculated using the protruded length of the fiber. Some applications of this method on SiC (PCS) fiber-reinforced LAS matrix composite were also carried out to determine distribution of interfacial frictional shear resistance of the specimen by protrusion method. 15 refs.

Kagawa, Yutaka; Honda, Koichi

1991-08-01

468

A protrusion method for measuring fiber/matrix sliding frictional stresses in ceramic matrix composites  

NASA Astrophysics Data System (ADS)

A simple technique to measure interfacial frictional shear resistance of fiber-reinforced ceramic matrix composites has been investigated. SiC (CVD) fiber-reinforced soda-borosilicate glass matrix composite containing single fiber was cut into perpendicular to the fiber and was placed on a hard SiC ceramic plate. Ductile metal plate was placed to the upper side of the composite and was subjected to uniform compression via metal plate. After unloading, the protrusion lengths of the fiber at the surface of the composite were measured by scanning electron microscope and the interfacial shear strength was calculated using the protruded length of the fiber. Some applications of this method on SiC (PCS) fiber-reinforced LAS matrix composite were also carried out to determine distribution of interfacial frictional shear resistance of the specimen by protrusion method.

Kagawa, Yutaka; Honda, Koichi

1991-08-01

469

SALTSTONE MATRIX CHARACTERIZATION AND STADIUM SIMULATION RESULTS  

SciTech Connect

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 by conducting leaching (water immersion) tests. Saltstone durability for this evaluation is limited to changes in the matrix itself and does not include changes in the chemical speciation of the contaminants in the saltstone. This report summarized results obtained to date which include: characterization data for saltstone cured up to 365 days and characterization of saltstone cured for 137 days and immersed in water for 31 days. Chemicals for preparing simulated non-radioactive salt solution were obtained from chemical suppliers. The saltstone slurry was mixed according to directions provided by SRNL. However SIMCO Technologies Inc. personnel made a mistake in the premix proportions. The formulation SIMCO personnel used to prepare saltstone premix was not the reference mix proportions: 45 wt% slag, 45 wt% fly ash, and 10 wt% cement. SIMCO Technologies Inc. personnel used the following proportions: 21 wt% slag, 65 wt% fly ash, and 14 wt% cement. The mistake was acknowledged and new mixes have been prepared and are curing. The results presented in this report are assumed to be conservative since the excessive fly ash was used in the SIMCO saltstone. The SIMCO mixes are low in slag which is very reactive in the caustic salt solution. The impact is that the results presented in this report are expected to be conservative since the samples prepared were deficient in slag and contained excess fly ash. The hydraulic reactivity of slag is about four times that of fly ash so the amount of hydrated binder formed per unit volume in the SIMCO saltstone samples is less than that expected for saltstone containing the reference amount of slag (45 wt.% of the total cementitious mixture versus 21 wt.% used in the SIMCO samples). Consequently the SIMCO saltstone samples are expected to have lower strengths, and tortuosity and higher porosity, water diffusivity, and intrinsic permeability compared to the reference case MCU saltstone. MCU reference saltstone contains nonradioactive salt solution with a composition designed to simulate the product of the Modular Caustic Side Solvent Extraction (MCU) Unit [Harbour, 2009]. The SIMCO saltstone samples were cast in molds and cured for three days under plastic with a source of water to prevent drying. Details of the sample preparation process are presented in Attachment 2. The molds were then removed and the samples were cured at a constant temperature (76 F, 24 C) and 100 percent relative humidity for up to one year. Selected samples were periodically removed and characterized the evolution of the matrix as a function of age. In order to preserve the age dependent microstructure at the specified curing times it is necessary to stop hydration. This was accomplished by immersing the samples in isopropanol for 5 days to replace water with alcohol. The microstructure of the matrix material was also characterized as a function of aging. This information was used as a base line for comparison with leached microstructures. After curing for 137 days, specimens were cut into 20 mm disks and exposed to deionized water with a pH maintained at 10.5. Microstructure and calcium sulfur leaching results for samples leached for 31 days are presented in this report. Insufficient leached material was generated during the testing to date to obtain physical and mineralogical properties for leached saltstone. Longer term experiments are required because the matrix alteration rate due to immersion in deionized water is slow.

Langton, C.

2009-07-30

470

Effect of the matrix on DNA electrophoretic mobility  

PubMed Central

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

Stellwagen, Nancy C.; Stellwagen, Earle

2008-01-01

471

Superstring vertex operators in type IIB matrix model  

SciTech Connect

We clarify the relation between the vertex operators in type IIB matrix model and superstring. Green-Schwarz light-cone closed superstring theory is obtained from IIB matrix model on two-dimensional noncommutative backgrounds. Superstring vertex operators should be reproduced from those of IIB matrix model through this connection. Indeed, we confirm that supergravity vertex operators in IIB matrix model on the two-dimensional backgrounds reduce to those in superstring theory. Noncommutativity plays an important role in our identification. Through this correspondence, we can reproduce superstring scattering amplitudes from IIB matrix model.

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

2008-06-15

472

Systems and methods for deactivating a matrix converter  

DOEpatents

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

Ransom, Ray M.

2013-04-02

473

Matrix recording media for optical information recording  

NASA Astrophysics Data System (ADS)

As an alternative to recording media on the tellurium base, recording media built in the form of matrix structures in which a photo(thermo)active component is included into the matrix can be used. We suppose that the most effective preparation method of such media which provides the deposition on substrates of any form can be a dissociation method of organometallic compounds (OMC). Depending on the choice of OMC, atmosphere in which occurs its decomposition, additions and conditions of process following there can be obtained by polymerization of OMC ligands in which is distributed a metal phase (metal-polymeric media) and an oxide matrix in which are implanted organic ligands changing its parameters. The gradient metal spreading was created by increasing the pulse amplitude of voltage discharge from 500 to 2000 V. The content of metal was increased in direction from substrate and was near substrate 0 - 10 at percent and near free film surface up to 80 at percent. The film composition was investigated by means of the layer-to-layer auger analysis using microscope JAMP-10 S. The comparative analysis of Raman spectra of starting OMCs and prepared from them films showed the advent of new bonds of the type metal-metal, carbon-carbon and the decrease of bonds quantity of the type carbon-carbon, metal-ligand. The action of focused laser radiation on such films leads to formation of microholes in the center of the irradiation region and on peripheral areas it leads to an additional OMC decomposition.

Petrov, Vjacheslav V.; Kryuchin, Andrey A.; Kostenko, Igor O.; Grinko, D. A.; Kravets, Vasiliy G.; Bondareva, E. I.

1994-12-01

474

T-matrix approach to shale acoustics  

NASA Astrophysics Data System (ADS)

The T-matrix approach of quantum scattering theory is used here to place many long-wavelength equivalent-medium approximations for porous composites, polycrystals and cracked media on a common footing and to indicate their limitations, but also to derive some new results based on two-point statistics. In this way, we have obtained an insight into the difficult problem of elastic inclusions at finite concentrations, which is of foremost relevance when estimating the effective material parameters of porous/cracked shales, involving stacks of more or less horizontally aligned clay platelets, mixed together with more rounded silt minerals, and with fluid filling the spaces. A rather involved perturbative analysis of the effects of interactions between (or structural correlations among) the various inclusions (minerals and cavities) making up a real shale of hexagonal symmetry was performed in an attempt to obtain a better match between theoretical predictions (based on a combination of coherent and optical potential approximations) and experimental results (recovered from ultrasonic wave speeds) for the effective elastic stiffness tensor. For the particular data set considered in this study, the T-matrix approach was able to match the data better than the approach of Hornby et al., but the match was not completely satisfactory. Further progress in theoretical shale modelling may come from a better knowledge of the elastic properties of pure clay minerals, a more detailed knowledge of the microstructure of shales, the incorporation of constraints obtained from comparisons between theoretical predictions and experimental results, as well as a continuing development of the T-matrix approach. Numerical results (also for the effect of bedding parallel microcracks on the elasticity of such a real shale) have value in illustrating the importance of taking into account the effects of spatial distribution when trying to deal with non-dilute mixtures of highly contrasting material properties.

Jakobsen, Morten; Hudson, John A.; Johansen, Tor Arne

2003-08-01

475

Low-power SXGA active matrix OLED  

NASA Astrophysics Data System (ADS)

This paper presents the design and first evaluation of a full-color 1280×3×1024 pixel, active matrix organic light emitting diode (AMOLED) microdisplay that operates at a low power of 200mW under typical operating conditions of 35fL, and offers a precision 30-bit RGB digital interface in a compact size (0.78-inch diagonal active area). The new system architecture developed by eMagin for the SXGA microdisplay, based on a separate FPGA driver and AMOLED display chip, offers several benefits, including better power efficiency, cost-effectiveness, more features for improved performance, and increased system flexibility.

Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

2009-05-01

476

Two-matrix model with ABAB interaction  

NASA Astrophysics Data System (ADS)

Using recently developed methods of character expansions we solve exactly in the large N limit a new two-matrix model of hermitian matrices A and B with the action S=1/2(trA2+trB2)- ?/4(trA4+trB4)-?/2 tr(AB)2. This model can be mapped onto a special case of the 8-vertex model on dynamical planar graphs. The solution is parametrized in terms of elliptic functions. A phase transition is found: the critical point is a conformal field theory with central charge c=1 coupled to 2D quantum gravity.

Kazakov, Vladimir A.; Zinn-Justin, Paul

1999-05-01

477

Matrix Metalloproteinases as Modulators of Inflammation  

PubMed Central

An increased expression of members of the matrix metalloproteinase (MMP) family of enzymes is seen in almost every human tissue in which inflammation is present. Through the use of models of human disease in mice with targeted deletions of individual MMPs, it has become clear that MMPs act broadly in inflammation to regulate barrier function, inflammatory cytokine and chemokine activity, and the generation of chemokine gradients. Individual MMPs regulate both normal and pathological inflammatory processes, and therefore, developing rational therapies requires further identification of specific MMP substrates and characterization of the downstream consequences of MMP proteolytic activity.

Manicone, Anne M.; McGuire, John K.

2008-01-01

478

Matrix Product States and Fractional Quantum Hall  

NASA Astrophysics Data System (ADS)

We present an exact matrix product state expansion (MPS) for a large series of Jack polynomial wavefunctions which serve as Fractional Quantum Hall ground-states of pseudopotential Hamiltonians. Using the basis of descendants in Virasoro and W algebras we build MPS descriptions of the (k,2) Jacks which include the Moore-Read state and the Gaffnian state, as well as MPS representation of the Z3 Read-Rezayi state. We then give a general method for computing MPS representations for other non-abelian states and their quasiholes.

Bernevig, B. Andrei; Estienne, Benoit; Regnault, Nicolas; Papic, Zlatko

2013-03-01

479

Matrix representation of multimode beam transformation  

NASA Astrophysics Data System (ADS)

The transformation of laser beams passing through optical systems is analyzed using a TEM modal decomposition. The laser beam is decomposed and the optical system is described by a matrix that relates the modal composition of the input and output beams. The hard aperture and the parabolic and Gaussian soft apertures are given a typical examples. The matrices that characterize these apertures allow analysis of the losses of laser resonators, including finite and/or variable reflectivity mirrors. The modal decomposition is used for defining modified ABCD matrices that include any kind of apertures.

Alda, Javier; Porras, Miguel A.; Bernabeu, Eusebio

1991-12-01

480

Massless Flavor in Geometry and Matrix Models  

SciTech Connect

The proper inclusion of flavor in the Dijkgraaf-Vafa proposal for the solution of N=1 gauge theories through matrix models has been subject of debate in the recent literature. We here reexamine this issue by geometrically engineering fundamental matter with type IIB branes wrapped on non-compact cycles in the resolved geometry, and following them through the geometric transition. Our approach treats massive and massless flavor fields on equal footing, including the mesons. We also study the geometric transitions and superpotentials for finite mass of the adjoint field. All superpotentials we compute reproduce the field theory results. Crucial insights come from T-dual brane constructions in type IIA.

Roiban, Radu; Tatar, Radu; Walcher, Johannes

2003-01-27

481

Performance of a matrix air heater  

NASA Astrophysics Data System (ADS)

This communication presents a study of a porous flat plate solar air heater. An earlier theory used to analyze such a system has been modified by using: (1) appropriate boundary conditions and also (2) by considering the realistic case of different air and matrix temperatures. Numerical calculations have been performed to bring out the difference between the earlier theory and the present theory. The results of the present theory are found to be in excellent agreement with the measurements of an experiment. The yearly performance of the system has also been evaluated for Delhi-type climates.

Sodha, M. S.; Bansal, N. K.; Singh, D.; Bharadwaj, S. S.

1982-10-01

482

Optimized purification for density matrix calculation  

NASA Astrophysics Data System (ADS)

We present an optimized linear-scaling purification method for calculation of the density matrix. Traditional purification polynomials, including those proposed by McWeeny and Holas, are monotonic and have stable fixed points at 0 and 1. We relax these conditions and develop optimized purification polynomials which achieve maximum reduction in the LUMO eigenvalue and maximum increase in the HOMO eigenvalue, while heading towards idempotency. We demonstrate that optimized purification achieves appreciable speedup over traditional purification, which increases with decreasing band-gap. We also show improvement over non-monotonic purification proposed by Rubensson, while having identical performance for polynomials of degree 3.

Suryanarayana, Phanish

2013-01-01

483

Zero minors of the neutrino mass matrix  

SciTech Connect

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

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

2008-10-01

484

Interfacial reactions in titanium-matrix composites  

SciTech Connect

A study of the interfacial reaction characteristics of SiC fiber-reinforced titanium aluminide and disordered titanium alloy composites has determined that the matrix alloy compositions affect the microstructure and the distribution of the reaction products, as well as the growth kinetics of the reaction zones. The interfacial reaction products in the ordered titanium aluminide composite are more complicated than those in the disordered titanium-alloy composite. The activation energy of the interfacial reaction in the ordered titanium aluminide composite is also higher than that in the disordered titanium alloy composite. Designing an optimum interface is necessary to enhance the reliability and service life at elevated temperatures. 16 refs.

Yang, J.M.; Jeng, S.M. (California Univ., Los Angeles (USA))

1989-11-01

485

Bayesian Inference for Nonnegative Matrix Factorisation Models  

PubMed Central

We describe nonnegative matrix factorisation (NMF) with a Kullback-Leibler (KL) error measure in a statistical framework, with a hierarchical generative model consisting of an observation and a prior component. Omitting the prior leads to the standard KL-NMF algorithms as special cases, where maximum likelihood parameter estimation is carried out via the Expectation-Maximisation (EM) algorithm. Starting from this view, we develop full Bayesian inference via variational Bayes or Monte Carlo. Our construction retains conjugacy and enables us to develop more powerful models while retaining attractive features of standard NMF such as monotonic convergence and easy implementation. We illustrate our approach on model order selection and image reconstruction.

Cemgil, Ali Taylan

2009-01-01

486

Acellular dermal matrix in primary breast reconstruction.  

PubMed

The use of acellular dermal matrix (ADM) in many plastic surgery procedures, including breast reconstruction, has increased dramatically in recent years. While expander/implant reconstruction can be performed successfully with standard techniques, the introduction of ADM has added a new tool with which to achieve lasting, predictable results. This article is a summary of existing literature on ADM for primary implant reconstruction, to provide a more thorough understanding of the benefits of ADM in single- and to two-stage breast reconstruction and to identify the areas where further investigation is needed. PMID:21908822

Sbitany, Hani; Langstein, Howard N

2011-09-01

487

Effective dynamics of the matrix big bang  

SciTech Connect

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

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

2006-05-15

488

Enumeration of RNA Structures by Matrix Models  

NASA Astrophysics Data System (ADS)

We enumerate the number of RNA contact structures according to their genus, i.e., the topological character of their pseudoknots. By using a recently proposed matrix model formulation for the RNA folding problem, we obtain exact results for the simple case of an RNA molecule with an infinitely flexible backbone, in which any arbitrary pair of bases is allowed. We analyze the distribution of the genus of pseudoknots as a function of the total number of nucleotides along the phosphate-sugar backbone.

Vernizzi, Graziano; Orland, Henri; Zee, A.

2005-04-01

489

Two-channel snapshot Mueller matrix polarimeter.  

PubMed

We describe a new setup for a snapshot Mueller matrix polarimeter (SMMP). It relies on the separation and orthogonal polarization of two light beams by a Wollaston prism located at the setup output. The simultaneous treatment of the two spectra allows an enhancement of accuracy for real-time measurements through reduction of the effects caused by random noise and systematic errors. Moreover, it gives insight into the nonuniform spectral response of the medium under study. Experimental results support the feasibility of the proposed technique. PMID:19935972

Dubreuil, Matthieu; Rivet, Sylvain; Le Jeune, Bernard; Cariou, Jack

2009-11-20

490

Bidirectional extracellular matrix signaling during tissue morphogenesis  

PubMed Central

Normal tissue development and function are regulated by the interplay between cells and their surrounding extracellular matrix (ECM). The ECM provides biochemical and mechanical contextual information that is conveyed from the cell membrane through the cytoskeleton to the nucleus to direct cell phenotype. Cells, in turn, remodel the ECM and thereby sculpt their local microenvironment. Here we review the mechanisms by which cells interact with, respond to, and influence the ECM, with particular emphasis placed on the role of this bidirectional communication during tissue morphogenesis. We also discuss the implications for successful engineering of functional tissues ex vivo.

Gjorevski, Nikolce; Nelson, Celeste M.

2009-01-01

491

Dynamics, Structure, and Function are Coupled in the Mitochondrial Matrix  

NASA Astrophysics Data System (ADS)

The coupling between molecular diffusion and the structure and function of the rat liver mitochondrial matrix was explored using fluorescence anisotropy techniques and electron microscopy. The results confirm that matrix ultrastructure and the concentration of matrix protein are influenced by the respiratory state of mitochondria and the osmolarity of the external medium. At physiological osmolarity, a fluorescent metabolite-sized probe was found to diffuse slowly in the mitochondrial matrix but not to be completely immobile. In addition, significant differences in diffusion rates were found to exist between different mitochondrial respiratory states, with the slowest diffusion occurring in states with the highest matrix protein concentration. These data support the concept of a matrix structure in which diffusion is considerably hindered due to limited probe-accessible water and further suggest that volume-dependent regulation of matrix protein packing may modulate metabolite diffusion and, in turn, mitochondrial metabolism.

Scalettar, Bethe A.; Abney, James R.; Hackenbrock, Charles R.

1991-09-01

492

Dynamics, structure, and function are coupled in the mitochondrial matrix.  

PubMed Central

The coupling between molecular diffusion and the structure and function of the rat liver mitochondrial matrix was explored using fluorescence anisotropy techniques and electron microscopy. The results confirm that matrix ultrastructure and the concentration of matrix protein are influenced by the respiratory state of mitochondria and the osmolarity of the external medium. At physiological osmolarity, a fluorescent metabolite-sized probe was found to diffuse slowly in the mitochondrial matrix but not to be completely immobile. In addition, significant differences in diffusion rates were found to exist between different mitochondrial respiratory states, with the slowest diffusion occurring in states with the highest matrix protein concentration. These data support the concept of a matrix structure in which diffusion is considerably hindered due to limited probe-accessible water and further suggest that volume-dependent regulation of matrix protein packing may modulate metabolite diffusion and, in turn, mitochondrial metabolism. Images

Scalettar, B A; Abney, J R; Hackenbrock, C R

1991-01-01

493

First matrix cracking behavior of ceramic composites at elevated temperatures  

SciTech Connect

The first matrix cracking behavior of a silicon carbide fiber (SCS-6{trademark})-reinforced zircon matrix composite is studied as a function of flaw size and temperature. Flaws of controlled size are created in the monolithic zircon and silicon carbide fiber-reinforced zircon matrix composite by means of a Vicker's indentation technique. The first matrix cracking stress is measured at three different temperatures of 25, 500, and 1200 C as a function of the crack length. The results on ceramic composites demonstrated both steady state and non-steady state matrix cracking behaviors and an increase in the steady state matrix cracking stress with an increase in temperature as predicted by the theoretical models. These results are compared with the predictions of the theoretical models of matrix cracking based on fracture mechanics analysis.

Anandakumar, U.; Kumar, S.; Singh, R.N.

1999-09-29

494

The extracellular matrix and ciliary signaling  

PubMed Central

The primary cilium protrudes like an antenna from the cell surface, sensing mechanical and chemical cues provided in the cellular environment. In some tissue types, ciliary orientation to lumens allows response to fluid flow; in others, such as bone, ciliary protrusion into the extracellular matrix allows response to compression forces. The ciliary membrane contains receptors for Hedgehog, Wnt, Notch, and other potent growth factors, and in some instances also harbors integrin and cadherin family members, allowing receipt of a robust range of signals. A growing list of ciliopathies, arising from deficient formation or function of cilia includes both developmental defects and chronic, progressive disorders such as polycystic kidney disease (PKD); changes in ciliary function have been proposed to support cancer progression. Recent findings have revealed extensive signaling dialog between cilia and extracellular matrix (ECM), with defects in cilia associated with fibrosis in multiple contexts. Further, a growing number of proteins have been defined as possessing multiple roles in control of cilia and focal adhesion interactions with the ECM, further coordinating functionality. We summarize and discuss these recent findings.

Seeger-Nukpezah, Tamina; Golemis, Erica A.

2012-01-01

495

Measuring Sparticles with the Matrix Element  

SciTech Connect

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

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

2012-04-10

496

Dynamic holographic interferometry with matrix LC modulator  

NASA Astrophysics Data System (ADS)

The method of holographic intereferometry with increased sensitivity was applied for measurements of height of nanosteps (from 10 nm and higher) with standard uncertainty about 0.5 nm. The initial microinterferogram with fringes of equal width was obtained in Michelson micro-interferometer with nano-step sample in one of legs. This interferogram was registered by CCD-camera and the digital interference pattern was reproduced on matrix phase modulator with spatial resolution 30 lines/mm. The matrix phase modulator was placed at the output of the two-beam Mach-Zehnder interferometer and illuminated by two plane laser beams. These two beams diffracted on phase modulator, were focused and spatially filtered by the pinholes in (+ 1-st ) and (- 1-st ) orders of diffraction. The second digital interferogram with twofold increase of sensitivity was obtained on CCD-camera and so on. The increase of sensitivity was obtained due to the interference of waves with complex conjugated phases. One can obtain the interference of higher orders too if working with the nonlinear interferogram. It is possible to obtain any carrier fringe space frequency by using of two plane waves in the interferometer. The increase of sensitivity may be obtained in research of flatness less than ?/100, and topography of surfaces with height difference less than few nanometers as well.

Pulkin, S. A.; Venediktov, V. Y.; Ivanov, V.; Korotkov, V. I.; Pasechnik, I. M.; Sevrygin, A. A.; Solov'ev, M. A.

2012-11-01

497

Molecular evolution of matrix metalloproteinase 20.  

PubMed

Dental enamel is a hypermineralized tissue, containing only trace amounts of organic components. During enamel formation, matrix metalloproteinase 20 (MMP20) processes proteins comprising enamel matrix and facilitates hypermineralization. In the human genome, 24 distinct MMP genes have been identified. Among these genes, MMP20 is clustered with eight other genes, including MMP13, and all these clustered genes show phylogenetically close relationships. In this study, we investigated MMP20 and closely related MMP genes in various tetrapods and in a teleost fish, fugu. In the genome of the chicken, a toothless tetrapod, we identified degraded exons of MMP20, which supports the previous proposition that MMP20 is important specifically for enamel formation. Nevertheless, for unknown reasons, we failed to identify MMP20 in the platypus genome. In the opossum, lizard, and frog genomes, MMP20 was found clustered with MMP13. Furthermore, in the fugu genome, we identified an MMP20-like gene located adjacent to MMP13, suggesting that MMP20 arose before the divergence of ray-finned fish and lobe-finned fish. The teleost tooth surface is covered with enameloid, a hypermineralized tissue different from enamel. Thus, we hypothesize that MMP20 could have been used in an ancient hypermineralized tissue, which evolved into enameloid in teleosts and into enamel in tetrapods. PMID:22243253

Kawasaki, Kazuhiko; Suzuki, Tohru

2011-12-01

498

The TRUPACT-II Matrix Depleton Program  

SciTech Connect

Contact-handled transuranic (CH-TRU) wastes will be shipped and disposed at the Waste Isolation Pilot Plant (WIPP) repository in the Transuranic Package Transporter-II (TRUPACT-II) shipping package. A primary transportation requirement for the TRUPACT-II is that the concentration of potentially flammable gases (i.e., hydrogen and methane) must not exceed 5 percent by volume in the package or the payload during a 60-day shipping period. Decomposition of waste materials by radiation, or radiolysis, is the predominant mechanism of gas generation during transport. The gas generation potential of a target waste material is characterized by a G-value, which is the number of molecules of gas generated per 100 eV of ionizing radiation absorbed by the target material. To demonstrate compliance with the flammable gas concentration requirement, theoretical worst-case calculations were performed to establish allowable wattage (decay heat) limits for waste containers. The calculations were based on the G-value for the waste material with the highest potential for flammable gas generation. The calculations also made no allowances for decreases of the G-value over time due to matrix depletion phenomena that have been observed by many experimenters. Matrix depletion occurs over time when an alpha-generating source particle alters the target material (by evaporation, reaction, or decomposition) into a material of lower gas generating potential. The net effect of these alterations is represented by the ``effective G-value.``

Connolly, M.J. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Djordjevic, S.M.; Loehr, C.A.; Smith, M.C.; Banjac, V.; Lyon, W.F. [Benchmark Environmental Corp., Albuquerque, NM (United States)

1995-12-01

499

The extracellular matrix and ciliary signaling.  

PubMed

The primary cilium protrudes like an antenna from the cell surface, sensing mechanical and chemical cues provided in the cellular environment. In some tissue types, ciliary orientation to lumens allows response to fluid flow; in others, such as bone, ciliary protrusion into the extracellular matrix allows response to compression forces. The ciliary membrane contains receptors for Hedgehog, Wnt, Notch, and other potent growth factors, and in some instances also harbors integrin and cadherin family members, allowing receipt of a robust range of signals. A growing list of ciliopathies, arising from deficient formation or function of cilia, includes both developmental defects and chronic, progressive disorders such as polycystic kidney disease (PKD); changes in ciliary function have been proposed to support cancer progression. Recent findings have revealed extensive signaling dialog between cilia and extracellular matrix (ECM), with defects in cilia associated with fibrosis in multiple contexts. Further, a growing number of proteins have been determined to possess multiple roles in control of cilia and focal adhesion interactions with the ECM, further coordinating functionality. We summarize and discuss these recent findings. PMID:22819513

Seeger-Nukpezah, Tamina; Golemis, Erica A

2012-07-19